Full text of "A dictionary of chemistry and allied branches of other sciences"

See other formats

Google

This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project

to make the world's books discoverable online.

It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject

to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books

are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover.

Marks, notations and other maiginalia present in the original volume will appear in this file - a reminder of this book's long journey from the

publisher to a library and finally to you.

Usage guidelines

Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the
public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing tliis resource, we liave taken steps to
prevent abuse by commercial parties, including placing technical restrictions on automated querying.
We also ask that you:

+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for
personal, non-commercial purposes.

+ Refrain fivm automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine
translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the
use of public domain materials for these purposes and may be able to help.

+ Maintain attributionTht GoogXt "watermark" you see on each file is essential for in forming people about this project and helping them find
additional materials through Google Book Search. Please do not remove it.

+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just
because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other
countries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of
any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner
anywhere in the world. Copyright infringement liabili^ can be quite severe.

About Google Book Search

Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers
discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web

at|http: //books .google .com/I

DICTIONARY OF CHEMISTRY

VOL. I.

lOHSOH

VBIVTSD BT SrOTTXSVOODX AVJ> CO.

KXW-GTSKBT 8QVABS

A DICTIONARY

CH EMISTKY

AlTD THB

ALLIED BRANCHES OF OTHER SCIENCES.

Founded on that of ike late Dr. Ure,

HENRY WATTS, B.A., F.C.S.

XDEIOB OF
*TBS JOtTBVAL OV THB CHBOGAL BOGBIT.'

ASSISTED BY EMINENT GONTBIBUTOBS.

IN FOUR VOLUMES.

VOL. I.

ABICHITE— CONGLOMERATE.

^ LONDON:
LONGMAN, GREEN, LONGMAN, ROBERTS, & GREEN.

1863.

ChcT)i ?'65

! V ^ 3 • -^'«- / 1 ( ' ?'

<^-^y

*>^fe'^**-r 4

PREFACE

rpniS WORK was originally intended sb a New Edition of Ure's
J- Dictionary of Chemistry and Mineralogy ; bnt the great changes made
m chemical science since the publication of the last edition of that Dictionary
(1831) — changes, not merely consisting in the addition of new discoveries,
but inTolTing a complete revolution in the mode of viewing and
expressing chemical reactions— have rendered it almost impossible to adapt
any matter written so long ago to the existing requirements of the science.
The present must therefore be regarded as essentially a new work, in
which <»ily a few articles of Ube's Dictionary are retained, chiefly of a
descriptive character. In compiling it, the Editor has freely availed
himself of the stores of information in Gmelik's " Handbook,^* Gerhardt's
" Chimie Organique,'' Rose's " Traits d' Analyse Chimique," Dana's
^ Mineralogy ,*' Rammelsbero's '^ Mineralchemie," the '* Handworterbuch
der Chemie," &c. ; and has endeavoured, by careful consultation of original
memoirs, to bring the treatment of each subject down to the present time.
He has also been fortunate in obtaining the co-operation of several
chemists of admowledged ability and eminence, who have kindly con-
tributed articles on subjects to which they have paid special attention : —
a List of their names is given on the next leaf.

The work is essentially a Dictionary of Scientific Chemistry, and ia
intended as a Gompamon to the New Edition of Ure's Dictionary of Arts,
Manufactures^ and MtTies^ to which therefore reference is, for the most
part, made finr the details of manufacturing operations; but those branches
of chemical manufacture which have come into existence, or have received
important developements, since the publication of that work, are described
in this Dictionary as fully as its limits will allow, and in all cases ex-
planations are given of the principles on which manufacturing processes
are conducted, and the chemical changes which they involve. Particular

A S

vi PREFACE.

attention has also been given to the description of processes of Analysis,
both qualitative and quantitative.

In order that the work may, as far as possible, truly represent the
present state of scientific chemistiy, it has been found absolutely necessary
tq make the modem or " unitaiy " scale of atomic weights the basis of the
system of notation and mode of exposition adopted. Especial care has,
however, been taken that the treatment of all Articles which are likely to
be consulted, for the sake of practical information, by manufacturers, or
others not exclusively occupied in chemical pursuits, shall be such as to
make them readily intelligpible to all who possess a general knowledge
of chemistry, though they may not have followed closely the recent
developements of the theoretical parts of the science. Hence, in all such
Articles (as Acetic Acid, Aktimont, Copper, &c.) the formulae are given
according to the old notation (printed for distinction^ in Italics), as well as
according to that adopted in the rest of the work.

Temperatures are given on the antigrade acale^ excepting wheil the
contnuty is expressly stated*

HENKT WATTS.

7 Pbovost Hoad, LoKDoir, N.W.
Jidy 1863.

LIST OF CONTRIBUTORS,

EDlfUNI) ATKINSON. Ph.D. P.C.8.

of Chemistry at the Royal Military Colle^, Sandhant.

FRANCIS T. CONINOTON, M.A. F.C.S.

rdlow of CorpM Chriati Collefce, Oxford, and late BxamiQer in Natural Science at that
Univenity ; Author of a * HandbcK>k of Chemical Analysia.'

WILLIAM DITTlf AB, Bsq.

Aaaiatant in the Chemical Laboratory of the Unif eraity of Bdinbuif h«

GEOBGB G. FOSTEB, BJL F.C.S.

on Natural Philosophy at the Andersonian Univenity, Olaagow.

EDWABD FBANKLAND, FIuD. F.B.S.

FoRign Secretary of the Chemical Society, and Profetaor of Chemistry at the Royal Institution
of Great Britain.

FBEBBBICE GUTHBIB, Fh.D. F.C.S.

Profeaaor of Chemiatry at the Royal CoUe^, Manritius.

A. W. HOFMANN, LL.D. F.B.8. V.P.O.S.

Fkoteaor of Chemistry at the Government School of Mines.

WILLIAM 8. JEVONS, M.A.
* Oatdy) Gold Aasayer in the Sydney Royal Mint.

Cff ABLES B. LONG, Bsq. F.CJS. (the late)
Analytical Chemist.

WILLIAM ODLING, MB. F.B S.

Secretary to the Chemical Society, and Professor of Chemistry at St. Bartholomew's Hospital ;
Aathm' of a * Manual of Chemistry.'

BENJAMIN H. PAUL, PIlD. F.C.S.
Consnltio|( Chemist

HENBY E. BOSOOB, Ph.D. F.C.S.

Professor of Chemistry at Owens CoUejpe, Manchester.

WILLIAM J. BUSSELL, Ph.D. F.C.S.
or Unirersity Collie, London.

ALEXANBBB W. WILLIAMSON, Ph.D. F.B.S. Pros. C.S.

Professor of Chemistry at University Colk^e, London, and Bxaminer in Chemistry at the
University of London. (A. W. W.)

ABTHUB WINCKLEB WILLS, Esq.

Analytical and Mannfactnrini^ Chemist, Wolverhampton. (W. W.) •

%* Aritoles oommunioated by the several oontributors are signed with their
initials ; articles taken from Ubb'b JHelionary of CAfmisiry (fourth edition, 1831) arc
Btgnod with the letter U ; those which have no signature arc by the Editor.

ERRATA.

T%e asterisk in the second column indicates thai the line is to be counted

from the bottom.

PAUB '

LUCE

—

16«

— .

«•

—

.—~

** 1

»•

29,33

in 1

13«

18 '

84*

38*, 94*

»•

-i/k

16»

—

8«

—

10»

—

8»

— ^

—

4«

«s

%•

—

23*. 4th ool.

33*,4thcoL

—

23*, 6th ool.

4»

9ft

100

103

1»

104

—

»•.

11»,18«

—

10«

107

litO

110

—

10 •

—

3»

113

110

£RKOR COBRSCnOV

Arftooid Acaroid

C»H»NO« C»H»NO

CH"0" CrH"0»

proportioii prepomtion

p. 19 p. 5

NaBr 2NaBr

C»H»0 CH»0

(CPH'NO)* (CH'NO)'

PCCH*)^) PCCTI')^)*

CH'NO* C*H»NO

00"Ba CJOTBa"

C» C»

3Pao +3Fao

C"H^)T»b C'H'O'Pb

principal, axiii principal axii»

CTB-(frQ C»H»0 \ o

c*H^r" C»H«or"

Benaoil Benzoyl

oonTertB into converts it into

C%31*0" CKn*0

mrthyl methylic oxide

(propylic) propylic

^^>"}o..... <<^Hr|o.

C*HT?aSO" CH'NaSO*

CHTIaSO* CHTNaSO*

for which which

C«ff«0 C'H"t)

C"H'"1TO" C*H"N*S*

C»H«IO.HJJ C*H»IO.ir.N

CHI-O.IP.N C*HI-O.H*.N

(CW)'"|p. (C-HW-Jo.

treated heated

(7H» C^'

C^-H"irO* CH^N-O'

phon>hoTOQ8 phosphorus

oonsuting of containing

and « ttie

diflBolTQB dissolve

in water ; less in idoohol in water, leas in alcohol ;

of birds of of birds

C^*0* C*H*0»

100* 160*»

160° 140°

when ^ with

1-0000 ~

9141 —

25 —

A to the mark < « to the mark «

C0« 00'

phosphoric aoid, and amyl- phosphoric add and amyl-

aloohol alcohol

bromoid^ bromides

The aldehydes may be re- The aldehydes are isomeric

gaitled as the ethers of the with the uthen of the

diatomic alcohols. diatomic alcohols (see

Btrkbs, and Ethtlsxk,
Oxide of)

C"H"W C"H"^)

Mannite Mannitan

C"H"0» C«H»"0»

C'*H^ C"H»»S'

c*H»cio« c*irno«

are the ethen are isomeric with the eilicr*

C"H"— «0 i>\\*«-*0

C"li3n _o» C"H*»-'0

condennatlon couomtration

to NUt of tartar and «• to wit of tartar, and tu

ciirhoiiatr of xtotaMslum CHrbonate of potassium

obtained obtained

■MACID8, Ke p. M KB Acms, p. W

uuntl^] ..cBDuithjt

PbBnn.[8] 1. Phuin. CMm.

BDlpbocTulde mlphooTUUte

CH-Bf JCH'Bi*

"^lAg HAjC

•^UCH^)) '^1{(7H'0)'

. O^'Br.Bi* O^'Bi-.ftr'

nl^MCTiaiide n^diMaraiuta

cm iCHI

<CHT'.(C?H').0' (C"HT'-(C*H')'0*

nlpluHTUlde ..,^...^.....,,.,,,nilphoo«uiAte
Alblene ii not knowD tn It bH dji» boon [»

hyphoiulphlte'.... hTpoAnlphlte

100 pB. □( axfgen 100 pU. of bIddiIiis

dyed-Toodi ..,.., ,...,..,......dje-WDOdfl

butbawi ........................ frtffbon"

PtCl.'0"H"N" PtCl'.C'H'TJ"

Ths pJiifAHnn«itt. li Tlwji/atinirBi-iBll In

K^di .,.,,..,....,.,....... 4., .addfl

MH* NH'

S<H^)f »(H^))f

H" jo* H- <)■

«H^)i MH^»r

CH-Br"! (TH'Bf I

(CH')-? f (CH-j-Pf

0^.0 1 ■ (TH'.O I

ffiS* i??S{

«?TI')T ■ (CH*)*?!

iiH*0| >>B*0)

«HS)t nH^;

v(<J^')i\v////^\y^"','."'.'.'.'.v(l7B•'yI

^aOJaic' ll\y.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. '. .' J jroO.MBO"

it>diit«..l'.!!''. '.'.'!'.'.!!'.'. !!!!'*"iodki»

mnat becdded to npmenta tha isfadtr of

to ba ■Uid to rapmniclDg tlia tmfmAtj of

H+ft+/. iT+ll-/

■topooi^'' itinxockB

polBt a pouil ■

trWAffO' 0'H"Ag^>'

C'H-O' - (TH'WtO'H')' 0"H*H)- = C'ff'O'tO'H')*

CBWIq. (O-H-WMq.

hrhnohloilc brdnKblDrlo'

CoBbQ* CnSbO'

tilnumjl MbtriraMliyl

iCJtHiiditjliiiiii lUlKit^lliim

C"H■^>• .o»ir"o"

CK'W CH-W

An-mra* Aira"s^*

tFSKy.'UV tFe^.ATV

<">£(<>• '"fflo-

IBaH'AaO'.Airo' + }H\) !D«H>A«-.Ai^>' + SHM

Cn'A*'„ Oa'AaW

AKCTnTCH-) A>{0'H")({J'H^*

A*^0^')"(CB-> Aj-d^HWCH')'

ERRATA.

TAGS

4Q0

10»

407

409

%&•

411

4»

4S4

427

433

foot-note

44S

18*

•^

17«

444

33 (of table)

—

» (of table)

84»

445

446

—

■>^

5»

— .

447

17*

449

39*

450

94*

13*

— .

10*

-»

9»

458

18*

461

6»

—

6«

465

16*

469

009

«•

531

io», n«

584

23»

937

38*

714

—.

10»

799

8»

1038

1041

1043

1041^

1049

21«

—

«•

1047

80*

—.

!«•

—.

lartline

1048

1049

last line

1050

—

18*

106S

—

19*

1094

1058

—

!!•

1059

1090

81*

1066

10*

—

1097

1«*

1099

1101

98»

1103

1104

ERKOR CORBKCriON

Aj((?H«)Pt A«(CJ^")»Pt

Afl"(CH*)1 Afi(CH»)»I

4N0»Cu 2N0»Cii

AflMeE* AsMeB*

O'H'CuNO* C*H'CuN*(>'

C^HTfO^-SO-H" C*H'NO*.SO*H«

chalk, or, limestone with chalk, or limestone, with

i»*=l n"-l

C?"H*0» CTE[*0

C!^'*0" C*H»«0

CJ*BTO* OH^O*

C*H»«0* C-H»«0»

(rH*0" C«H*"0"

(?T3}*0 Off«0

CTa*o cp'H*©"

(CIP)-;" (CHrl^

3*36 23*6

C*H*"SO* (Tff'SO*

CS- , C»«

Tolnmes whence volnmes : whence

C»H*NO* (3TI-N0

KNifio* KNiSO*.

•©• ©•©

•® mo

®#® o«o

sojphide snlphate

Odoride of of Hypochlorite of

Hypodilorite Chlorite

87*6 187-6

Csb)« (SO*)"

WBctlou reaction

an ontwaxd presenile a pressnie from withont

[2] 59 [23 269

wort wool

Kisselzinkerz Eieeelzinken

Od Ca

18'51 1851

P<80 p. 1086

p. 40 p. 1046

p. 86 p. 1043

p. 53 p. 1058

P.«7 p. 1048

P-89 p. 1045

P*84 p. 1040

P-46 p. 1063

P. 88 p. 1044

p. 88,84 p. 1039,1040

P*88,88 p. 1044,1045

P.fiO p. 1066

p. 87, 88 p. 1048,1044

p. «1 p. 1057

p. 88 p. 1044

p. 48 p. 1064

P>48 p. 1064

P*45 p.1051

P-44 p. 1050

p. 87 p. 1043

p. 40 p. 1046

p. 58 p. 1069

p. 61 p. 1067

p. 59 p. 1065

p. 63 p. 1068

p. 88 p. 1094

p. 89 p. 1095

p. 88 p. 1094

p. 94 p. 1100

DIOTIONAET OF OHEMISTET.

(Aphaneiiie, Sirahlerg, Strahlenhipfer*) A natiye arsenate of
eopper, found cliieflj aasodated with other oopper ores and reins in Cornwall, and
in the Harts. The cejBtalB belong to the monoclinic or ohUque prismatic system,
bat thej seldom exhibit any definite shape, being aggregated in radiating groups,
or disposed, as extremely minute individiials, in cavities of quartz. Sp. ^. 4*2
to 4*4. Hardness, 2*5 to 3. Translucent or opaque, with Titreous lustre. Colour,
blaAish green inclining to blue. Streak, bluish-green. Dana (Mineralogy, iL p. 428)
gives for this mineral the formula SCuO^AsO^ + ^CuO.HO\ or AsCu>0« + Cu'HO*,
deduced from the analyses of Rammelsberg andBamour. L. Gmelin (Handb. y. 471)
gives the formula 60uO.AsO^ + 5H0, deddeed from the analysis of Chenevix, who
Ibnnd 64 per cenL of protoxide of copper, 30 per cent, of anhydrous arsenic acid, and
16 per eent of water.

EC ACXB. C'H'K)^ When Strasburg or Canadian turpentine (ob-
tained respectively from Abies picea and Alnes haUamea^) is distilled with water; the
residue exhausted with absolute alcohol ; the solution evaporated to dryness ; the re-
sidual resin boiled with twice its wei^^ht of solution of carbonate of potassium ; the
alkaline liquid poured off; and the residue, which is a mixture of abietin and abietate
of potassium, treated with 30 times its weight of water, — abietin separates in
the oystalline form, while abietate of potassium remains in solution. This solution
may be decomposed bv sulphuric or hydrochloric acid, and the precipitated abietie
add purified by digestion in hot aqueous ammonia. As thus obtained, it is a resinous
mass which dissolves easily in alcohol, ethtiir and volatile oils, forming acid solutions,
from which it separates in the oystalline state« At 66^ it becomes soft and trans-
lucent. Its barium-salt is said to contain 191 parts of the add to 76*6 parts ^1 at)
of baiyta. The add is perhaps identical with sylvie or pymaric add. (Caillot»
J. Fhum. xvi 436; Gerh. iii. 666.)

Prepared as above. It is a tasteless inodorous resin, insoluble in
water, soluble in alcohol, espedaHy at the boiling heat, also ia ether,^ rock-oil, and
strong aoetie add, and separates in the crystalline form from these solutions by evapo-
ration. It melts when heated, and solidifies in a crystalline mass on cooling. It is
not acted upon by caustic potash. (C aillo t.)

( Gismondin,) A mineral of the zeolite frmily, containing, according
to Uarignac*8 analyds:

8(CaKO.SiO«) + 4Al<0*.SiO« + 18H«0 ; [Si - 28 ; 0 « 16].

or 2(CaO.KO)Ac^ + 2(AP(^,8iO^ + 9HO; [-«-21; 0«8].

It is found on Yesutius, at Ad-Castello in Sidly, and at Capo di Bove, near Borne.
It ocean united with Phillipsite in quadratic octahedrons, generally aggregated in

• The stenic weffhts adopted In thli work «ra those of the imlunr iritem (U •• 1 ) O » 16 ; S = 8S t
C a |«). Fr«qiMotlj, bowerer, the formute of compound! wiU likewise be given aecordlne to the
doalistic system {Om 8, 5 a 16, C« 6) ; and for distinction, these Utter formulse will be printed ia

Vol. I. B

2 ABSINTHIN—ACEDIAMINE.

maflses. Transparent or translacent, with greyish-white colour. Hardness » 4*5.
Sp. gr. s 2-265. Giyes off one-third of its water at 100^. Easily dissolves in acids
and gelatinises. It was formerly supposed to be a Tsriety of Phillipsite or lime-
harmotome ; but it diifeonr from harmotome in composition as well as in crystalline form,
the latter mineral crfstallisi^g in the dimetric system. (Dana, ii. 322.)

JLBSZMTBIVk CE'H)*. The bitter principle of wormwood (Artemisia ahnn-
thium). It is prepared in the pure state, according to Luck, by exhausting the leaves
of wormwood with alcohol, evaporating the extract to the consistence of a svrup,
and agitating with ether. This ethereal solution is evaporated to dryness, and the
residue treated with water containing a little ammonia, which dissolves the resin, and
leaves the absinthin nearly pure. To complete the purification, it is digested with
weak hydrochloric acid, waaned with wat^, dissolved in alcohol, and troated with
acetate of lead, as long as a precipitate is formed. After the removal of this precipi-
tate by filtration, the excess of lead is precipitated by sulphuretted hydrogen, and the
solution is evaporated. The absinthin then remains as a hard, confdsedly crystalline
mass, possessing an extremely bitter taste. It is but slightly soluble in water, very
.soluble in 'alcohol, and less so in ether. It possesses distinctly acid characters, and
is dissolved by potash and ammonia. (Kein, Ann. Ch. Pharm. viii 61 ; Luck, ibid.
Ixxviii. 87; Gerh. iv. 258.)

AB80&FTZ0W OF OABB8. See Gases.

ACACZV, or ACACXA-OUSK. Known in commerce as^um-aro^. See Ababin
and Guic.

AOABXO&ZTB. A variety of chabasite firom New Caledonia, distinguished by
its laige amount of alkalL (H ay e s. Sill. Am. J. [2] I. 122.)

ACAJOV. The stem of the Acj\jou or Oashew-nut tree, Anaoardium ocoideniaUj
yields a yellow gummy substance, sparingly soluble in water, which is a mixture of
ordinary gum and bassorin. The pericarp of the nuts of the same tree contains a
large quantity of a red-brown resinous substance, which produces inflammation and
blistenng of the skin. It may be extracted by ether, and the ethereal solution when
slowly evaporated, leaves a residue consisting of a network of small crystals of ana-
cardic acid, soaked in an oily liouid called cardol, to which the resin owes its acrid pro-
perties (Stadeler, Ann. Ch. Pharm. Ixiii. 137). The name acijou is also applied
to a gum and resin obtained fkom the stem of the mahogany-tree. The g^om re-
sembles that of the cherry-tree.

AJKACOXB SBSZV. The resin of Xanthorrhea hasHliSf a liliaceous tree grow-
ing in New Holland ; also called resin of Botany Bay. It has a yellow colour, an agree-
able odour, and is soluble in alcohol, ether, and caustic potash. Its potash-solution
treated with hydrochloric acid deposits benzoic and dnnamic acids. Nitric acid con-
verts it into picric acid, and so readily, that this resin appears to be the best raw material
for obtaining picric acid. By distillation, the resin yidds alight neutral oil, which ap-
pears to be a mixture of benzol and cinnamol, and a heavy acid oil, consisting of hydrate
of ph^ivl, mixed with small quantities of benzoic and cinnamic adds. (Stenhouse,
Aim. Ch. Pharm. IviL 84.)

AOBCnnbOBXBB OP F&ATZVmMC. See Acbtomb, Deoompotiiioru (p. 29).

ACBBZA Ml Jl Mm G*H*N'. When hydrochlorateofacetamide is heated in a sealed
tube to 180^ — 200^, and the product afterwards distilled, or when acetamide is dis-
tilled in a stream of dry hydrochloric add gas, several volatile |nx)ducts pass over, and
a residue is left consisting of hydrochlorate of acediamine^ mixed with sal-ammoniac.
(See Agbtamide) :

2C»H»N0« + Ha - C«H«N«. HCl + C»H*0«.

"Y"

Acetunldei 11]rdrochlorRte Acetic add.

ofacediamlne.

Alcohol extracts the hydrochlorate of acediamine from this residue, and deposits it
by spontaneous evaporation in prismatic crystals, which may be completely fireed from
adhering sal-ammoniac by solution in a mixture of alcohol and ether, and evaporation
in vacuo. The hydrochlorate decomposed by sulphate of silver, yields the avfphate of
acediamine (CHW)'. SO*H', which aystallises in colourless nacreous laminse, easily
soluble in water. The aqueous solution of the hydrochlorate mixed with dichloride of
platinum yidds the chloriplatinate of aoediamne^ CH*N». HCi PtCl*, in rather large,
hard, yellowish red prisms.

Acediamine is very unstable, and cannot be obtained in the free state. When the
sulphate or hydrochlorate is heated with potash or baiytOi ammonia is given off, and
an acetate of tiie alkali is produced :

C«H«N« + 2H«0 = C«H*0« + 2NH«.

ACETAL. 8

Aeediaaiiiie nuiir be veguded as ammonU in which 1 at. H is replaced Inr the moxia*
tanie ladieal C*H*N (acethyl), its rational fonmda being then K.H'. CH^N or as a
^tooble molecule of ammoma» N'H^haTing 3 at. H replaced by the triatomic radical
C*IP, making its formula N*.H*. (C^*)'" It bears the same relation to aoetamide aa
ethykmine to aloohol:

C*H«0 + NH* « (^BTS + HK): and C»H«NO + NH« « C»H«N« + H«0.

(Streeker, Ann. Pharm. diL 328.)

HI' HPMQgCIMlO ACD and ACB9KIIS8XC AOSD* Componnds produced
by Ihe action of phoq>hoxuB on acetone (see page 28).

A.GSVA&. C^"0>.— [Gm. ix. 38 ; Gerh. iL 268.] A product of the oxidation
of alcohol, first observed by Bobereiner, more fully examined by Liebig (Ann. Gh.
Pharm. t. 25; xiy. 166), still further by Stas (Ann. Oh. Phys. [3] xix. 146^ who
first correctly determined its empirical formula, and finally by Wurtz (Compt. rend.
xlriiL 478 ; Ann. Ch. PhysJ^S] xlviii. 370 ; Ann. Ch. Pharm. cviiL 84). It is also
obtained from aldehyde. (Wurtz. u. Frapolli, Ann. Ch. Pharm. cvii. 228.)

Pr^uraiion. I. From Alcohol. 1. Sy the imperfect oxidation of alcohol, under
the inflnenoe of platinum-black. Pieces of pumice-stone previouslv washed and
ignited are moistened with nearly absolute alcohol, and placed at the bottom of a
large wide-necked fladc, which is then filled up with eapsules containing platinum-
black, oorered with a glass plate, and exposed to a temperature of 20°, tifi the whole
of the alcohol is acidified. Alcohol of 60 per cent, is then poured into the flask, in
qnantity not quite sufficient to coyer the pumice-stones, and the flask left to itself for
tvo or three weeks in a room at a temperature of 20°, the glass plate being removed
from time to time to admit f^h air. The thickish liquid is then drawn oS, and the
same process repeated with fresh alcohol, till several quarts of thickish acid liquid are
obtained. This liquid is neutralised with carbonate of potassitun, saturated with
chloride of calcium and distilled, and the first fourth of the distillate is saturated with
fused chloride of calcium, whidi separates from it a mixture of alcohol, acetic-ether,
aldehyde^ and acetaL The aldehyde is removed by distillation over the water-bath ;
the residiie treated with strong potash to decompose the acetic ether; the alcohol
rmoTed hj waahing with water; and the remaining liquid, the acetal, dried over
chloride or oalcinm and rectified. (Stas.^

2, By difftilling alcohol with dilute sulphuric acid and peroxide of manjD;anese. A
mixture of 2 parts alcohol, 3 parts peroxide of manganese, 3 parts sulphuric add, and

2 parts water (the proportions given by Liebig^ for the proportion of aldehyde),
is subjected to distillation as soon as the frothing which first ensues has ceased ;

3 parts of liquid are distilled ofiT; the distillate is rectified ; and the portion which
goes over at 80° is collected apart from that which distils between 80° apd 95°.
The first portion is mixed wim chloride of calcium and rectified, the distillate
obtained below 60° chiefiy consisting of aldehyde, while above 60° a product is
obtained, which, when treated with a strong solution of chloride of calcium, yields
an ethereal liquid. The portion of the former liquid which came over between 80°
and 96°, is also rectified, and the first portion of the resulting distillate treated with
stnmg aofaition of chloiide of calcium, inierenpon it likewise yields an ethereal liquid.
Tiieae ethenal liquids, containing aldehyde, acetic ether, £e. and acetal are united,
and shaken with caustic potash to resinise the aldehyde and decompose the acetic
ether. The brown liquid which fioats upon the potash-solution is separated and
distilled; the distillate again mixed with chloride of calcium; the liquid thus separated
is heated to 100° for twenty-four hours with twice its volume of caustic potash in a
sealed tube ; the lower stratum is rectified ; the distillate again shaken with chloride of
calehim ; and the separated liquid is digested with pulverised chloride of calcium, and
submitted to simple xectaflcation. Pure acetal then distils over from 100° to 105°.
(Wurta.)

3. By the actk>n of chlorine upon alcohol, acetal being indeed the {vincipal pro-
duct of that reaction, so long as no substitution-products are formed:

30«H*0 + 2a - C«H»H)« + 2Ha + H«0.

Chlorine is passed through 80 per cent aloohol cooled to between 10° and 15°, till
a pofrtion becomes turbid on the addition of water, indicating the formation of substi-
tation-prodncts. One fourth of the strongly add liquid is then distilled off; the dis-
tillate nenbralised with chalk ; one fourth acain distilled off; and the distillate, con-
sisting of alcohol, acetic ether, aldehyde and acetal, treated as above to separate the
acetal. (Staa)

According to Li eb en (Ann. Ch. Phys. [3] Hi. 313), the chief products of the action
of cfalraine on alcohol of 80 per cent, are monochloracetal and dichloracetal. (p. 19.)

n. Vrcfm Aldehyde, 1. By treating aldehyde with pentabromide of phosphorus,

4 ACETAL.

whereljy it is converted into hronUde ofethylideiM C«H*Bi* (a compmmd iflomeric inth
bromide of ethylene), and acting on this componnd with ethylate of sodiom.

C*H*Br* + 2C«H*NaO « NaBr + 2C«H"0«.

This mode of preparation is, however, veiy troublesome, on account of the difficulty
of obtaining the bromide of ethylidene. Chloride of ethylidene C*H*C1«, (produced by
the action of pentachloride of phosphorus on aldehyde) does not appear to yield acetal
when treated with ethylate of sodium.

2. By passing hydrochloric acid gas into a mixture of 1 vol. aldehyde and 2 vols,
absolute alcohol immersed in a freezing mixture, whereby the compound C*HH)10 is
obtained in the form of an ethereal liquid floating on aqueous hydrochloric acid, —
and treating this compound with ethylate of sodium:

C*H*0 + C"H«0 + Ha - C*H"aO + H«0
and C«HK310 + C«H»NaO = NaCl + C^»*0«

(Wurtz imd FrapoUi, Compt. rend. xlviL 418 ; Ann. Ch. Pharm. cviii- 223.)

Properties, — ^Pure acetal is a colourless liquid, less mobile than ether, having a pecu-
liar agreeable odour and a refireshing taste, with an after-taste like that of hazel nuts.
Sp. gr. 0-821 at 22-4. Boils at about 106° C, with the barometer at 0768 met
Vapour density == 4*141.

It dissolves in eighteen times its volume of water at ordinary temperatures, the
solubility increasing as the temperature rises. From the aqueous solution it is sepa-
rated by chloride of calcium and other soluble salts. Ether and alcohol dissolve it in
all proportions.

Decompositions, — 1. Acetal is not altered by mere exposure to the air, but in contact
with platinum-black it is quickly converted, first into aldehyde, and then into acetic
acid *

C«H"0» + 20 = 8C«H*0 + B?0.
> — r— ' "*— t— -^

Acetal. Aldehyde.

It is likewise oxidised by nitric and by chromic add. 2. Caustic alkalies do not decom-
pose it, if the air is excluded. 3. Chlorine abstracts hydrogen from it and forms sub-
stitution-products. 4. Strong sulphuric acid dissolves and. then decomposes it, the
mixturo turning black. 6. Hydrochloric add likewise dissolves and blackens it, form-
ing choride of ethyl. 6. Pentachloride of phosphorus acts strongly upon it, formine a
la^ quantity of chloride of ethvl, together with other products. 7. Heated in a sealed
tu^ with several times its weignt of glacial acetic add, it yields acetic ether, more than
1 atom of that compound being formed from 1 atom of acetal.

These reactions tend to show that acetal is an ethyl-compound. Stas regarded it
as a compound of 1 at. aldehyde with 1 at. ether:

C*H*0 + C*H»»0 = C^»0« ;

and YTurtz, in his earlier researches on glycol (Compt. rend, zliii. 478), regarded it as

glycol m [ 0*, in which 2 at hydrogen are replaced by ethyL^jg^^v, [ 0*. This view

of its constitution was corroborated by the result of distilling a mixture of alcohol and
wood-spirit with sulphuric add and peroxide of manganese, wheroby a distillate was

obtained consisting of dimethylate of ethylene /rvat^At 0*, and methylethylate of ethy-

CH* )
lene nH'CH*[^* Subsequent researches have however shown that acetal is not

identical, but only isomeric with diethyl-glycol, or diethylateof ethylene CH*. (CH*)*. 0'.
For, when glycol CH^.H'.O' is treated with sodium, 1 at hydrogen is eliminatecl, and

specific gravity of 0*7993 at 0^ C, and boils at 123*5 C, whereas acetal has a sp. gr.
of 0*821 at 22<^*4, and boils at 105°, that is to say, 18^*5 lower. Becent experiments
byBeilstein (Ann. Ch. Pharm. cxii. 240) seem to indicate that the ration^ formula
of acetal is CH»O.CH».0.

Chloraoetals (A.Lieben,Ann.Ch.Phys.[3]lvi. 313). Three of these compounds
have been obtained ; viz. mono-^ di-, and tri-cluoracetal. The two former are produced
by the action of chlorine on alcohol of ordinary strength (80 per cent) When the
chlorine has been passed through for some time, and the heavy oil which separates on
addition of water is washed several times with aqueous chloride of caldum, and sub-
mitted to fractional distillation, it begins to boil at 80°, and the boiling point gradually

ACETAMIDE. 5

rises to 200^, not^ howerer, zemaimng stationazj at any intermediate point. The por-
tiott vliieh distOa below 120^ oonsiBts of aldehyde and compound ethers ; that which
diatila abore 120° (which is the larger portion) contains monochloraoetal and diehlor-
leeUL On again aabmitting it to fractional distillation, the greater part goes oyer
between 170^ and 185° ; tiiis portion consists chiefly of dichloracetal, whi(£ may be
obteined pore by sabseqnent rectification. To separate the monochloracetal, the por-
tion of the seeond distillate boUing below 170°, and the portion of the first distifiate
which passed aver aboTe 120°, are heated for several days with aqueous potash,
whereby a watearr liquid ia obtained, containing chloride and formate of potassium,
sad an otQy liqida consisting chiefly of monochloracetal mixed with dichloracetal ; these
compounds are finally separated by fractional distillation.

Aeootding to lieben, the product of the action of chlorine on alcohol of ordinary
stRDgth does not contain acetaL This is contrary to the statement of Stas, who, in
fiieth prepared acetal by this reiy process. Probably the relative quantities of acetal,
moooddoraeetal, and dichloracetal obtained depend on the duration of the action of the
dilorine (eompare page 3).

MfmoeUcraettal, O^*H)10', is a colourless liquid, having an ethereal aromatic odour,
and boiling at about 155°. Vapour-density, by experiment 6*38 ; by calculation (2 vols.)
5*29. It IS perfectly neutral, insoluble in water, soluble in alcohol It is not attacked
bj aqoeoQS potash, and does not precipitate nitrate of silver.

Diehloraeeial, G^H^'Cl^O', is a colourless neutral aromatic liquid of sp. gr. 1*1383 at
14°. Boils at about 180°. Yapour-density, by experiment 6*45 ; by calculation
(2 voh.) 6-435. (Lieben.)

TrieUoraeetal^ C^"C1*0', is produced, together with dichloracetal, by the action of
ehlorine on highly concentzated but not absolute alcohoL (Dumas, Lieben.)

ACmrjkMBmm, Cm'NO » N.H'.G*H"0. Produced :

1. By heating acetate of ethyl with strong aqueous ammonia to about 120° :

C>HK).C*H».0 + NH» - NH«.C*H»0 + C?H».H.O

Acetate of ethyl. Aceumlde. Alcohol.

2. By tlie action of ammonia on acetic anhydride :

(C«H»0)H) + NH» « NH«.C«H«0 + C«H«O.H.O

Acetic Acetamide. Acetic acid,

anbjdride.

3. By distilling acetate of ammonium (C«H<0«.NH« « C«H»NO + H«0). A large
quantity of ammonia is given off at first, then at 160° an acid distillate, consisting
diiefly of acid acetate of ammonium ; above 1 60°, a distillate containing acetamide
which crystallises in the condensing tube ; and above 190° nearly pure acetamide.
By saturating glacial acetic acid with dry ammoniacal ^, and then distilling, | of the
acetic acid may be converted into acetamide. (Kundig, Ann. Ch. Pharm. cv. 277.)

Acetamide is a white crystalline solid, which melts at 78° and boilB at 221° or 222°.
It deliquesces wheA exposed to the air, and dissolves readily in water. Heated either
with adds or witJi alkalis, it takes up water, and is converted into acetic acid and
amiiMwiin. — ^Distilled with phosphoric anhydride, it gives up water and is converted
into aeetonitrile or cyanide of methyl CH*^. — Heated in a stream of drv hydrochloric
add gas, it yields a liquid and a crystalline distillate, and a brownish non-volatile
residue; The liquid portion of the <£8tillate consists of strong acetic add, together
with small quantities of diloride of acetyl, and perhaps acetonitrile. The crystalline
distillate ia a mixture of hydrochlorate of acetamide, and a compound of acetamide
and diacetamide CH*N0.OH'N0* ; the latter compound may be extracted by ether,
in which the hydrochlorate of acetamide is insoluble. The non- volatile residue con-
sists of hydrochlorate of acediamine mixed with sal-ammoniac The decomposition is
r^oesented by the following equations :

2C*H»N0 + Ha = C*H'NO« + Nffa

' 1— ^

DiaceCamide.

2C«H»N0 + HCl = C*H«N«.Ha + C«H<0«

Hydrochlorate Acetic

or acediamine. add.

O«H»N0 + 2Ha « C*HK)CI + IfKHJl; C*H^O - H«0 = C«H*N.

f I

Chloride of Acetonitrile.

acetyl.

Acetamide acta both as a base and as an add, combining with hydrochloric and with

nitrie add, and likewise forming salts in which 1 atom of its hydrogen is replaced by

amet^

5 ACETAMIDE.

1 By mixing acetamide fused at a gentle heat with oxychlonde of phosphorua,
diflflolTuie the resnlting crystalline mass in absolute alcohol, and learing the solution
to cooLop better, mixing it with ether; hydrochlorate of acetamide is then obtained
in colourless crystaUine needles. The crvstaUine mass first produced, appears to be
a compound of acetamide and oxychlonde of phosphorus, and this, on addition of
alcohoV yields phosphate of ethyl and hydrochloric acid, which unites with the
acetamide :

2OTt*N0 + POa« + 3(C*H*.H.O) « (C*H»NO)«.Ha + P(C«H»)«0 + 2HCL

2. By directing a stream of dry hydrochloric acid gas on a solution of acetamide in
alcohol and ether cooled from without, washing the resulting crystalline mass with
anhydrous ether, and dissolving it in warm alcohol The solution on cooling, or more
quiily on addition of ether, deposits the hydrochlorate in crystals. This mode of
preparation is preferable to the former. The compound forms lone spear-sha^ crystals,
having an add taste and reaction, easily soluble in wat«r and alcohol, but insoluble in
ether. Heated in a sealed tube to between ISQO and 200°, it decomposes, yielding
the same compounds that are obtained by heating acetamide in dry hydrochloric acid

^^itrate of Acetamide, C"H»NO«.NO«H, is obtained by dissolving acetamide in cold
strong nitric acid. It forms colourless acid crystals, which melt at a moderate heat,

and detonate at a higher temperature, leaving scarcely any residue.

CBLORACsetAMny^ — Monochloracetamide, C*H*CLNO = N.H«.0*H«C10. is

obtained :

1. By the action of ammonia on monochloraoetate of ethyl:

C«BW:!10.0«H».0 4- NH» - N.H».C*H«C10 + C^W.

2. By bringing perfectly dry ammoniacal gafl in contact with chloride of mono-

chloracetyl : QtstdOQi + 2NH» - N.H".0»H"C10 + NHKJL

The product is a white amorphous mass, from which absolute alcohol extracts the
amide, and deposits it in large shining laminae. The amide dissolves in 10 parts of
water and 10| parts of alcohol at 24° but is very sparingly soluble in ether. It is
decomposed by potash, yielding chloride and acetate of potassium. (E. Willm. Ann.

Ch. Phys. [3] xlix. 99.)

Trichloracetamide. C*H*Ca«NO « N.H».C«C1"0. This compound is produced

by the action of gaseous or aqueous ammonia:

1. On chloride of trichloracetyl :

(?a«o.a + 2NH» - N.H».(?a»o + wssx

2. On trichloraoetate of ethyl :

C?C1K).C«H».0 + NH« - N.H«.0«C1"0 + C«H«0.

3. On ohloraldehyde, G*C1^ 0, or the polymeric compound, perehloracetie ether,

c*a«o*:

C*aH) + 2NH» - C«H*a«NO + lTH*a

Also by the action of ammonia on the perchlorinated ethylic ethers of formic, carbonic,
oxalic, and succinic acids, dSi these compounds yielding chloraldehyde when heated.
The best product is obtained from perehloracetie ether. The mass is treated
with cold water to dissolve the sal-ammoniac, and the residual trichloracetamide is
crystallised from ether. It then forms snow-white crystalline laminse. It dissolves
also in boiling water and in alcohol, and crystallises from the aqueous solution in ta-
bular crystals belonging to the rhombic system. It has a sweetish taste ; melts at
136°, begins to turn brown at 200°, and boils at about 240°. It gives off ammonia when
heated with potash. Ammonia dissolves it after a while, and the solution yields, by
evaporation, beautiful prisms of trichloracetate of ammonium. Anhydrous phos-
phoric add converts it into chloracetonitrile or cyanide of trichloromethyl : C'H'Cl'NO
-H«0«C»C1"N. (Cloez, Ann. Ch. Phys. [3] xvii. 806; Malaguti, ibid. xvi. 6;
Cahours, ibid, xix. 362; Oerhardt, Compt. chim. 1848, 277; Trait^ i. 760;
Gm. ix. 270.)

Tetraohloracetamide, C*HC1^0-«N.H.CLCK?1^; sometimes called chlora-
cetamic add, is formed by exposing trichloracetamide, slightly moistened with water, to
the action of chorine in sunshine. It then sublimes in needles, which may be purified by
crystallisation from ether. It is permanent in the air, melts when heated, and partly
sublimes undecomposed. It is nearly inodorous, but has a harsh disagreeable taste.
Insoluble in water, but dissolves pretty readily in alcohol and wood-spirit, and very
easily in other. It dissolves without decomposition in cold aqueous alkalis, forming

ACETIC ACID. 7

aysUOisable salts. When boiled with potash, it gires off ammonia^ and leaves chlo-
nde and carbonate of potassium :

C«Ha*NO + 8HK) = NH» + iKCi + 2 C0«.

(Cloes, Ann. Ch. Phys. [3] xvii. 305.)

Bromaeetamides and lidaeetamidea are likewise known.

IhACKTAMiDB, C^H'NO* » NH(CHK>)*. The ethereal solution of the oomponnd of
aoetamide and diacetamide obtained b^ the action of hydrochloric add gas on ace-
tamide, deposits, when hydrochloric acid ^as is passed through it, spicnlar crystals of
hydiochloiHte of acetamide^ and the liquid filtered therefrom yields by cTaporation
OTcr sulphuric add, crystals of diacetamide, easily soluble in water, alcohol, and ether.
The eiystals when boiled with adds are resolved into acetic acid and ammonia, but
not so readily as acetamide. The alcoholic solution boiled with dichloride of platinum
deposits chloroplatinate of ammonium. (Strecker.)

Ethtlacbtaiiidb. See Ethtlamikb.

Mebcubaobtamidb, CH^HgNO. An aqueous solution of acetamide saturated
with mercuric oxide deposits by evaporation in vacuo, colourless ciystalline crusts
sparingly soluble in aloohoL mlver-acetaimde^ CH^AgNO, is obtained in a similar
manner in oystalline scales.

PHBirrLACBTAlfXDB, OT ACETAllILIDa, SCO PHHNn.AiaiIB.

Synonyme of ErKVUsini and QLBiiAin Gas.

Esmgaavre, Adde AcHique. C«HH)» = ^^^^ \ 0, or 0»H»0«.H.

The hydrate or hvdrated oxide of acetyl; it may be regarded as a molecule of water
(HH)), in which ha]f the hydrogen is replaced by acetyl CHK). (It was formerly
supposed to be derived from a nulide, C*M\ also called acetyl, which, in combination
with 3 atoms of oxygen, formed anhvdious acetic add C*JI*0^i and this in com-
bination with an atom of water Hu, formed hydrated acetic add, C*H*O^MO=^
C*B*0^ SeeAcBTTi«

SemrecB, — ^AeeCic add exists, in nature, in the oxsanic kingdom only, being found
in the juiees of many plants, espedally of trees, and existing probably also in several
of the animal secretions ; but more commonly it results from the decomposition and
oxidation of organic bodies.

ForwuUion, — 1. By the destructive distillation of organic substances, especially of
wood. — 2. Sy the action of oxidising asents, viz. atmospheric oxygen, chromic add
nitric add, hypochlorons add, &&, on alcohol and other organic b<>dies. — 3. By. the
action of hydrttke of potassium or hydrate of sodium at a high temperature on various,
oiganic bodies, e.a. suodnic add, oldc add, malic add, sugar, alcohol, &c. — 4. By
heating cyanide of methyl, with aqueous caustic alkalis: CH'.CN + 2HK> w, C<H*0*
+ NH*. — 5. By the action of carbonic anhydride on sodium-methyl ; CO* -i- CH'Na »
C^'KaO* (acetate of sodium).— > 6. By the reducing action of sine or sodium-amalgam
on ehloiaoetic add.

Prep€tration. — 1. From alcohol. Alcohol is converted into acetic add by various
processes of oxidation; e.^. by the action of spongy platinum. If a tray of finely-
diTided ^ongy platinum be placed on a triangle over a porcelain dish containing a litUe
alcohol gently warmed, and the whole covert with a bell-glass standing on a wedge,
and open at the top so as to allow a gentle current of atmospheric air to pass through
the apparatus, the oxidation of the alcohol proceeds rapidly, acetic add condensing in
abundance on the indde of the bell-jar.

By this process, however, much of the alcohol is converted into aldehyde, and lost
by volatilisation. It would appear, in fact, that, in the formation of acetic add by
dirwt oxidation, aldehyde is always developed as an intermediate product^ espedally
if the ooddismg influence be not sufficiently rapid —

(?H«0 + O - C«H*0 + H»0; and C»H«0 + 0 - C«H*0«.

Alcohol. Aide- Aide- Acetio

hyde. bjde. add.

The oxidation of alcohol by atmospheric oxygen is greatly promoted by the presence
of ferments ; and, in £ict, in the ordiuury processes for making vinegar, an alcoholic
solution is exposed to the joint influence of air and a ferment. In Prance and Ger-
many wine is usually employed, and in England malt

Won VnraoAB ( Wdnetng, VinaigTe\'-T\M following is the pUn of making vinegar
piaetised in Paris. The wine destined for vinegar is mixed in a large tun with a
quantity of wine-lees, and the whole being transfenred into doth-sacks, placed within
a large iron-bound vat, the li<ffid matter is squeesed through the sacks by superin-
cumbent pressure. "What passes through is put into large casks set upright and

8 ACETIC ACID.

haTing B small aperture at the top. In these it is exposed to the heat of the san in
summer, or to that of a store in winter. Fermentation supervenes in a few days. If
the heat should then rise too high, it is lowered hy cool air and the addition of fresh
wine. In the skilful regulation of the fermentative temperature consists the art of
makinff good wine-vinegar. In summer, the process is generally completed in a
fortn^t ; in winter, double the time is requisite. The most favourable temperature
is between 25^ and 30^ (77^ and 86^ FX The vinegar is then run off into barrels
containing several chips of birch wood. In about a fortnight it is found to be
clarified, and is then fit for the market. It must be kept in close casks.

At the same time that the alcohol is thus acidified, the nitrogenous organic matters
which have served as ferments have likewise assumed new forms, and settled at the
bottom of the vessel in the form of a white gelatinous mass, known as '* mother of
vinegar." This substance, which has been described bj Mulder as a AingoSd plants,
under the name of Mycoderma Vini, is a nitrogenised body, which has the power of
exciting tSie acetiftcation of pure alcohol in the presence of atmospheric air, probably
in consequence of its own tendency to change. By treating it with potash, the whole
of the nitrogen is removed, pure cellulose alone remaining.

A slight motion is found to favour the formation of vinegar, and to endanger its
decomposition after it ia made. Chaptal ascribes to agitation me operation of thunder,
though it is well known, that when the atmosphere is highly electrified, beer is apt to
become suddenly sour, without the concussion of a thunder-storm. Vinegar does not
keep well in ceUars exposed to the vibrations occasioned by the rattling of carriages.
The lees, which had been deposited by means of isinglass during repose, are thus
jumbled into tiie liquor, and promote the fermentation.

Almost all the vinegar of the north of France being prepared at Orleans, the manu-
facture of that place has acquired such celebrity as to render the process worthy of a
separate consideration.

The Orleans casks contain nearly 400 pints of wine. Those which have been
already used are preferred. They are placed in three rows, one over another, the upper
ones having an aperture of two inches diameter, k(n>t always open. The wine for aoe-
tification is kept in acyoining casks containing beech shavings, to which the lees
adhere. The wine thus clarified is drawn off to make vinegar. One hundred pints of
good vinegar, boiling hot, are first poured into each cask, and left there for eight days;
ten pints of wine are mixed in, every eight days, till the vessels are Aill ; and the
vinegar is allowed to remain in this state fifteen days, before it is exposed for sale.
The manufacturers at Orleans prefer wine of a year old for making vinegar ; but if
the wine has lost its extractive matter by age, it does not readily undergo the acetous
fermentation.

The used casks, called motherSt are never emptied more than hali^ but are succes-
sively filled again, to acetify new portions of wme. In order to judge if the mother
works, the vinegar makers plunge a spatula into the liquid; and according to the
quantity of froth which the spatula shows, they add more or less wine. In summer,
the atmospheric heat is sufficient. In winter, stoves heated to about 76^ Fahr. main-
tain the requisite temperature in the manufactory.

Qtdck mfithod of Vinegar-making {SchndUsaigbereitung), Since the efficient con-
version of the alcohol into acetic acid essentially depends upon the completeness of the
oxidation, the German chemists have proposed to promote this result by enlarging
the surfiicc of the liquid exposed to the air. This is effected l^ allowing the alcoholic
liquor to trickle down in a fine shower from a colander through a large oaken tube
(called the vinegar generator, or graduator), filled with beech chips, up which a cur-
rent of air ascends mrough apertures in the sides. By the oxidation which goes on,
the temperature of the liquid rises to 37® or 40® C. (100 or 104° Fahr.). The liquid
requires to be passed three or four times through the cask before the acetification is
complete, which takes place in twenty-four or thuly-six hours. Care should be taken
to allow a sufficient supply of air.

In England the same result is often attained by causing the alcoholic liquor to be
distributed by means of a Barker's mill or other contrivance, over the beech shavings
in a tun, whilst a current of air is forced up through it by two boating gasometers
which are made to rise and fall alternately by steam power.

Wine vinegar is of two kinds, white or red, according as it is prepared firom white or
red wine. It contains, besides acetic acid and water, sugar, colouring matter, gum, and
salts, especially bitartrate of potassium. Its specific gravity varies from 1-014 to 1*022.

M\LT VnfBOAB. — This is prepared from malt or a mixture of malt and raw barley,
which is mashed with water as in the ordinary operation of brewing ; the wort is then
submitted to the vinous fermentation and tne liquor thus obtained is converted by
oxidation into vinegar. This effected in two ways ; either by the process of fielding
or stoving.

When fielding, that is, exposure to the open air, is resorted to, tlie wort must be

ACETIC ACID. 9

made in the ipring months, and then left to finish during sereral months of the
vum season. In eonseqnence, therefore, of the length of time required, the latter,
or giomnff prooess, is more generallj used. The wash is introduced into barrels
wtinding endvaya, tied oTer with a coarse doth, and placed dose together in darkened
chambers. aztificiaUy heated hy a store. The liquor remains in these barrels nntQ the
aoetification is eomplete. This nsnallj occapies several weeks or months. The product
is next xntrodnoea into large tons with false bottoms, on which rape (the residuary
frnit from the making of British wines) is placed, and allowed slowly to filter througn
them. Bdow the fidse bottom and above the true one is placed a tap which allows
the vinegar to flow into a back or cistern. From this cistern a pump raises the liquid
to the top of the vesselt and thence it flows through the rape to be again retomed. Or
sometimes the npe tuns are worked by pairs^ one of them beiuff quite filled with
risegar from the barrels, the other only thi^ parts, so that tiie acetification is
exdted more readily in the latter than the former, and every day a portion of the
rinegar is oanveyed firom one to the other, till the whole is finished and fit for sale.

Ibdt vinegar has a yellowish red colour, an a^eable add taste, which is due to
acetic add ; but the aromatic odour which distingmshes both it, and also wine vinegar,
from p^rroligneons add (to be afterwards described) is imparted to it by the presence
of acetie and other ethers.

Vinegar of four dififerent strengths is sold by the makers, distinguished as Kos. 18,
20, 22, and 24. The last, which is the strongest, and is called proof vinegar, contains
6 par eent. of real acetie add ; its specific gravity is 1*019. (Per eir a.)

vinegar is liable to undergo a putrefactive decomposition, which was believed by
the makers to be prevented by the addition of sulphuric add, and they are allowed
hj law to add one-uiousandth part by weight of sulphuric add. It is now known that
thia is unnecessary; nevertheless the practice is stUl continued.

XhsmxED YiMSOAB. — ^By submitting wine or malt vinegar to distillation it is deprived
of its eolouring and other non-volatUe matters, a colourless limpid liquid being obtained
which is known in commerce as distilled vinegar. The product is, however, always
weaker than the vinegar from which it has been derived, because the boiling point of
strong acetic add is above that of water ; it is also liable to be contaminated with a
BBttQ quantitv of alcohol and empyreumatie bodies.

2. From Wood. Wood YuraaAB, or PTBOiJOiniOus Acm.— The ^naier part of the
aeetie add now employed in the arts is obtained by the destructive distillation of wood.
The wood is heated in large iron cylinders like gas retorts, connected with a series of
condensing vessels, the uncondensable ^ases which are evolved in large quantity being
eonvayed by pipes into the fire and aiding to maintain the heat. The liquid which
eondeDses in the receivers consists of water, tar, wood-spirit or methyUc alcohol,
acetate of methvl, and acetic add. The watery liquid, after bein^ separated from the
tar, is redistillecl, the wood'Spirit passing over among the first portions of the distillate,
and the acetic or pyroligneous aad afterwards. The add thus obtained is coloured,
and has a strong tarry flavour, which cannot be removed by redistillation. To purify
this crude add, it is converted into acetate of sodium, either by direct saturation with
carbonate of sodium, or more economically by saturating it with carbonate of caldum,
and decomposing the caldum-salt with sulphate of sodium ; and the acetate of sodium is
purified firom tany matter, flrst by gentle torrefaction, and afterwards by recrystallisar
turn. It is then decomposed by strong sulphuric add diluted with hdf its weight of
water, whereupon the sulphate of sodium, being insoluble in acetic add, separates in
the crystalline form, and may be separated hy simple decantation ; and the acetic acid
thus separated is purified from the last traces of sulphate of sodium by distillation.

The process just described yidds a very pure acid, but it is too ezpendve, prind-
pally in consequence of the large quantity of fud which it requires. A more economical
process has been proposed l^ Y olckel (Ann. Ch. Phaim. IxxxiL 49 ; Chem. Soc. Qu. J.
V. 274). In this process the crude wood-rinegar is immediatdy saturated with lime,
without previous rectification. Part of the tarry matter then separates in combination
with the lime, while tiie rest remains in solution with the acetate of caldum. The liquid,
after being diarified by repose, or by filtration, is evaporated down to half its bulk in
an iron pot, and nuxed with a quantity of hydrochloric add, sufficient to give it a slight
add reaction. The greater part of the tarry matter then separates, and may be skimmed
off from the surfikce. The hydrochloric add also decomposes certain compounds of the
lime with creosote and other volatile substances, which are then expelled by heat ; 33
, gallons of crude wood- vinegar require for purification from 4 to 6 lbs. of hydrochloric
' add. The acetate of calcium thus purified is completely dried and distilled with hydro-
chloric add, 100 parts of the dry salt requiring from 90 to 95 parts of hydrochloric add
of sp. gr. 1*15 (or 20^ Bm.). The sp. gr. of ttie acetic acid thus obtained is about 1*06
{89 Bm.). If it contains hydrochloric acid, it may be purified by redistillation, with
addition of a small quantity of carbonate of sodium, or better, 2 or 3 per cent of

10 ACETIC ACID.

bichromate of potaasiiim, which; at the same time, destroya certain oigaaie impnritiea
tiiat impart a peculiar odour to the acid.

The presence of hydrochloric or aulphuric add in yinegar is easily detected by boil-
ing the liquid for about twenty minutes with a small quantily of potato-starch, then
leaving it to cool and adding; a few drops of iodide of potassium. If the vinegar is
pure, Uie bhie colour of iodide of starch immediately makes its appearance, but not if
sulphuric or hydrochloric acid is present^ because these acids boiled with starch con-
vert it into dextrin, which is not coloured blue by iodine (Payen). Sulphuric acid
may also be detected by chloride of barium, and h^rdrochloric acid by nitrate of silver.

[For further details of the manufacture of acetic acid, see the new edition of Ur^s
JHctionary of JrtSy Manufactures and JIftnef, toL l pp. 6 to 20.]

Crtstaixisablb or Gijlcial Acetic Aoid. — This term is applied to the pure acid
C'H*0^[or C*IP(F\ of sp. gr. 1*0635, because it is at ordinary temperatures a ciTstalline
solid. The acid obtained by either of the processes above described consists of this com-
pound more or less mixed with water. On difltilling this dilute acid, a weaker acid
passes over, and a stronger add remains behind, because the boiling point of aqueous
acetic add increases with its concentration ; and by repeated fractional distillation, an
acid is at length obtained which crystallises at a low temperature. Ciystallisable acetic
add is, however, more conveniently obtained by distilling certain acetates in the diy
state with an equivalent quantity oi concentrated sulphuric add or disulphate of potas-
sium; tbus with acetate of potassium:

20«H«K0« + SO*H« - 20»H*0« + SO*K«.
and: C«H>KO« + SO^HK «. C*H*0« + SO*K«.

The proportionfl required are 98 pts. of dry acetate of potassium, or 82 acetate of
sodium, or 79 acetate of caldnm, or 163 acetate of lead, to 49 parts of monohydrated
sulphuric add, SO^H*, or 186 parts of disulphate of potassium, SO^HK. Gladal acetic
acid may also be conveniently obtained from diacetate of potassium, C^*KO'.G*H^O*
by simple distillation. Wben neutral acetate of potasdum is mixed with aqueous
acetic add, not too dilute, and distilled, part of the acetic acid unites wim the
neutral acetate, and a weaker add passes over. But as the distillation goes on, the
acid potassium-salt decomposes, the distillate becomes continually richer in acetic
add, and at length the pure crystaUisable add distils over. The temperature must
not be allowed to exceed 300^; otherwise the acid suffers partial decomposition, and
becomes coloured (Melsens, Gompt. rend. xix. 611). — Crystallised acetate of copper
also yields gladal acetic acid, when dried at a temperature between 160° and 180°
and afterwards distilled at a higher temperature. Towards the end of the distillation
the add becomes mixed with acetone : that which passes over towards the middle
must be redistilled to free it from copper mechanically carried over, probably in the
form of cuprous acetate. The add obtained by this process was formerly called
Spiritua Aeruginis or Spiriius Veneris.

Properties. — ^Pure acetic add solidifies at or below 16^ C. in prismatic or tabular
crystals. In dosed vessels it remains liquid at 12°, and does not solidify till tiie
Tessel is opened and shaken. Its i^>edfic gravity in the solid state is 1*100 at 8*5
(Persoz). It melts at 16° (Lowitz), at or above 22°'5 (Mollerat), forming a
thin colourless liquid of sp. gr. 1*063 (Mollerat) ; 1*065 at 13° (Persoz) ; 1*0635 at
15° (Mohr); 1*0622 (Sibille- Auger); 1*08005 reduced to 0° (Kopp, Pogg. Ann.
Ixxii. 1). It boils at 119° (SAbille-Auger); at 117°*3 (Kopp). The density of its
vapour is different at different temperatiures, compared with an equal bulk of air at
the same temperature. At temperatures considerably above the boiling point, it follows
the ordinaipr law of condensation to 2 volumes ; thus at 300° and upwards the sp. gr. of
the vapour is found b^ Cahours to be 2*00, wluch agrees almost exactly with the calcu-
lated density, supposing the molecule to occupy 2 volumes. For the atomic weight of
acetic add, compared with hydrogen as unity is 60 (^ 20 + 4H + 20 ■» 24 + 4 + 32);
and if this be tne weight of 2 volumes of the vapour, it follows that the weight of
1 volume of vapour, or m other words, the specific gravity as compared with hydrogen,
will be 30 ; and multiplying this number by 0*0693, the sp. gr. of hydrogen referred
to air as unity, we obtain for the sp. gr. of acetic add vapour referred to air as unity,
the number 2*079.

But at temperatures near the boiling point, the density of the vapour is much

greater, exhibiting a condensation to |-volume, or even less. The following table ex-
ibits t^e density of the vapour at various temperatures as determined byOahours
(Compt rend. xix. 771 ; xx. 51):

Temperature. 125° 130° 140° 150° 160° 170° 190° 200° 230° 250° 800°
Density. 3*20 312 2*90 2*75 2*48 2*42 2*30 2*22 2*17 2*09 2*08

The tension of the vapour is 7 mm. at 15° ; 14*5 mm. at 22°, and 32 mm. at 32°.
(Bineau, Ann. Ch. Phys. [3] xviil 226.)

ACETIC ACID.

The add iuB a pungent sour taste and odour, blisters tHe eikm, and acta as an acrid
poiBon. It does not redden litmus paper per se, but very strongly when mixed with
vHter.

DeeomptmHens, — 1. The Tapour of aeetio acid is inflammable, and bums with a
blue flame, pfodudng water and carbonic acid. When it is passed through a red-hot
tabe, the greater part remains unaltered, but a portion is cwcomposed, yielding free
caiboii and combustible gases, together with acetone, napthalin, hydrate of phenyl and
benaoL (Berthelot, Ann. Ch. Phys. [3] zxxiiL 296.)

8. A mixture of gladal acetic and strong aulphurie acid blackens when heated,
giving off carbonic and sulphurous anhydrides. Fvming sulphuric acid mixes with
gladu aeetie acid without evolution of gas ; but the mixture becomes hot, and if it be
raised to a higher temperature, carbonic anhydride is given ofi', mixed with onlv a small
quantity of siuphuious anhydride. Sulphuric anhydride disqplves in acetic add without
evolution of gas, and on heating the mixture, sulphacetic add is produced.

3. Acetic add is not sensibly attacked by nitric acid.

4. Beriodie add converts it into carbonic or formic add, with formation of iodic
add and separation of iodine.

5. Chlorine in sunshine converts acetic acid into monochloracetic and trichloracetic
adds^ the quantity of the one or the other being greater, according as the acetic add
or the chlorine is in excess. See CHLOBiLCBTic Acid.

6. Glacial acetic add heated with bromine in a sealed tube forms bromacetic and
dibRMoaoetLe adds. Iodine has no action on acetic add even in sunshine.

7. WUh peniaehloride of phosphorus, gladal acetic add forms hydrochloric add,
'^^^iT''^* of acetyl and oxyehloride of phosphorus : *

CWBP0.H.0 -¥ PCl«.a« - C«H«0.C1 + HCl + P0.C1«.

8l With pentasulphide of phosphorus^ it forma thiacetic add and phosphoric
gnfavdride:

6(0»H«O.H.O) + P*S» « V^O* + 5(OTP0.H.S).

The difierence between the mode of action of the pentachloride and pentasulphide
of -diosphorus, the former giving rise to two distinct chlorine-compounds, CH'O.Cl and
HQ, whereas Ute latter forms only one sulphur-compound, is very remarkable, and
shows dearly tilie propriety of regarding chlorine as a monatomic, and sulphur as a
diatomie radidc

Aqubous Acsno Acm. — Acetic add mixes with water in all proportions, impart-
tqg to it its taste and smell. The dendty of the aqueous add varies with its
strength in a remarkable manner. When water is gradually added to glacial acetic
add, the density increases till a hydrate is formed containing 79 pts. of crystallised
add to 21 water, and having the composition CH*0'. HK). This hydrated add has
a density of 1*073 and boils at 104°. All farther additions of water diminish the
density of the add.

The following table constructed by Mohr (Ann. Ch. Pharm. xxxi. 277) gives
the quantity of crystaUisable acetic add in 100 pts. of the aqueous add of different
denattiea.

F^cffc

Sp^ Gr.

Perc.

Sp. Gr.

Perc.

Sp. Gr.

Perc.

Sp. Gr.

Perc

Sp.Gr.

100

10636

1-0736

1-067

1-061

1-027

10666

10736

1066

1-060

1026

10670

1-0732

1-066

1-049

1026

1-0680

1-0732

1066

1-048

1-024

1-0690

1-0780

1064

1-047

1023

1-0700
1-0706

1-0720

1064

1-046

1-022

1-0720

1-063

1046

1-020

1-0708

10720 ;

1-063

1-044

1-018

1-0716

10710

1062

1-042

1-017

1-0721

10710

1-061

1-041

1-016

10730

1-0700

1060

1-040

1016

1-0780

10700

1-069

1039

1-013

10730

10700

1-068

1-038

1-012

10730

10690

1-066

1036

1-010

1-0730

1-0690

1-065

1-036

1-008

10730

1-0680

1065

1-034

1-007

10730

1-0680

1054

1-033

1-006

1-0730

1-0680

1-063

1-032

1004

10780

1-0670

1062

1-031

1002

1-0732

10670

1-061

1029

1001

12 ACETIC ACID.

Mollerat, Ann. GliinL Ixviii. 88, and Ad. van Toorn (J.pr. Chem. vi 171) bare
also given tables of the specific gravities of acetic acid of different degrees of concen-
tration.

It will be seen from the preceding table that the specific gravity of acetic acid varies
bat slowly, a difference of 1 per cent, corresponding to a difference of only *001 in the
density, and sometimes even less. For this reason, the determination of the strength
of commercial acetic add by the hydrometer or acetometer^ as it is called when gra-
duated for this purpose, is not much to be depended on. The presence of colouring
matter, saline substanees and other impurities, which frequently occur in vinegar, are of
course an additional source of inaccunu^ in this method of estimation. It is better,
therefore, to determine the strength ox the add by ascertaining the quantity of a
standard solution of caustic soda or ammonia, required to neutralise a given volume.
(See AcfmDCBTBT and Analysis, Yoluiietbio.) This method, when applied to acetic acid,
is affected with a slight source of inaccuracy, arising from the fact that the normal or
neutral acetates of the alkalis exhibit a slight alkaline reaction. The error thence
arising is, however, of small amount, not exceeding -^ per cent for an add containing
10 per cent of crystallisable acetic add, as shown by Otto (Ann. Ch. Pharm. cii. 69).
Moreover, it may be completely obviated by using a solution of caustic soda^ g^uduated
for the purpose by means of a solution of pure acetic add of known strength (Ajtaltsis,
VoLUMBTBic). Greville Williams (Pharm. J. Trans, xiii. 694) recommends for the
volumetric estimation of acetic add a graduated solution of lime in sugar-water.

Acetic add mixes in all proportions with alcohoL It dissolves resins, gum-zesins,
camphor, and essential oils. Its use for culinary purposes is well known. Its odour
is employed in medicine to relieve nervous head-ache, fainting fits, or sickness occa-
sioned by crowded rooms. Pungent smelling salts consist of sulphate of potassium
moistened with gladal acetic acid. P^ligneous add is largely used in calico-printing ;
the tar and empyreumatic substances present in it appear to \^ rather advantageous
than otherwise for that purpose. Large quantities of acetic add are also used for the

Separation of the acetates of lead, copper, aluminium, &c. (See Dictionary of Arts,
'ant{faeture8, and Mines,)

Acetates. — ^Acetic acid is monobasic, the general formula of its normal salts being
C«H»0*.M [or C^H^O'M - C^IPO'.MOX the symbol M denoting a metal It also
forms basic salts, whidi may be regarded as compounds of the normal acetates with
oxides^ The normal acetates all dissolve in water, and most of them readily. The
least soluble are the silver and mercuiy salts, so that solutions of other acetates added
to mercurous nitrate or nitrate of silver, throw down white shining scales of mercurous
acetate or silver-acetate ; but generally speaking, acetates are not formed by precipita-
tion : they are produced by the action of acetic add on metallic oxides or carbonates ;
many carbonates, however, the barium and calcium salts, for example, are not decom-
posed by acetic add in its most concentrated state, but only after addition of water.

All acetates are decomposed by heat ToiotA of them yielding carbonic anhydride, ace-
tone and an empyreumatic oil. Those which are easily decomposed, and likewise contain
bases forming stable carbonates, are almost wholly resolv^ into acetone and a car-
bonate of the base ; this is especially the case with acetate of barium :

2C"H«0«Ba « CTa[«0 + CO^a.

Those which, like the potassium and sodium salts, require a higher temperature to de-
compose them, yield more complex products, but always a certain quantity of acetone.
Among the products are found certain homologues of acetone, viz. methyl^wttons
C?H»(CH")0 and ethylacetone 0«H»(C«H")0, together with dumasin C^»»0. (Fittig,
Ann. Ch. Pharm. ex. 17). Acetates containing weaker bases, give off part of the
acetic acid undecomposed, the remaining portion being resolved into acetone and
carbonic anhydride, or if the heat be strong, vielding empyreumatic oil and charcoal : the
residue consists sometimes of oxide, sometimes, as in the case of copper and silver, of
reduced metal ; in this case part of the acetic add is burnt by the oxygen abstracted
from the metal. Acetates heated with a large excess of fixed caustic alkaU, are resolved
at a temperature below redness into marsh gas and alkaline carbonate, e, g, :

C«H*KO* + KHO « CH* + CO"K«.

Acetates distilled with sulphuric add, give off the odour of acetic add, and yield a
distillate which dissolves oxide of lead, and acquires thereby an alkaline reaction. Dis-
tilled with sulphuric and alcohol, thej 3rield acetate of ethyl, recognisable by its odour.
The neutral acetates impart to solutions of ferric salts a reddish yellow or red-brown
colour, according to the degree of dilution. Acetates heated to redness with ar-
senious add give off the odour of cacodyl. The acetates of the alkali-metals, and
probably others also, treated with oxychloride of phosphorus, yield chloride of acetyl,
together with a tribasic phosphate:

3(C*H«O.Na.O) + PO.a> « 3C*H»0C1 + PO<Na«.

ACETIC ACID. 13

AcsiATBS OF Aldoniuii. — o. TnooetaU, As alnminiiun is flesquiatomic (Al* being

eqinTalent to B^ or Al^ to H) the normal salt should be a triacetate C'HK)*jSi^ or

(C^K)^^*, [or APO^.ZC*H*(^t regarding it as a compound of alumina with an-
hjdrons acetic add]. This salt, howeyer, exists only in solution, and is decomposed
hj er^oration. The solution is obtained by digesting recently precipitated trihydrate
of almtiininm in strong acetic acid, or by precipitating a solution of the trisulphate
vith acetate of lead:

(S0*)»A1* + 6C*H«0*Pb « 3S0*Pb« + 2(C«HH>*)»A1«.

Tlds salt 18 largely used as a mordant in dyeing and calico-printing, and is generally
prepared for this purpose by precipitating alum with acetate of lead. The solution
thus formed contaJTis sulphate of potassium as well as acetate of aluminium.

iSL Diaeetaie. When the solution of the triacetate obtained by decomposing trisul-
pbite of ahiininium with acetate of lead is evaporated at a low temperature, with
sufficient r^ndity, as by spreading the concentrated liquid yery thinly on plates of
gjaas or poroelain, exposing it to a temperature not exceeding 100° F. (37^*7 C.), and,
as it runs together in drops, rubbing it constantly with a spatn^ diacetate of aluminium

nmaina in the Harm of a dry powder containing ^ a1« [ ^^ "^ 6H*0 [or, using the

snaller atomic weights of carbon and oxygen, 2C*JS*0^,AjP(^ + BHO], The diacetate
thus obtained dissolves easily and completely in water, and the solution when heated
deposits dihjdrate of aluminium soluble in water. (See AxnoMiuic.) But when the
aotution, instead of being quickly evaporated, is left to itself in the cold for some days,
it deposits a white saline crust, which is an allotropic diacetate of aluminium imoluble in
water. Heat effects the same change more rapidly, and the insoluble diacetate then
separates in the &rm of a granular powder. At the boiling temperature, the liquid is
thus depnved in half an hour of the whole of its alumina, which goes down with } of
the acetic add, leaving 1 in the liquid. The insoluble diacetate digested in a lar^
quaatily of water is gndually changed into the soluble modification, part of which is,
however, decomposed during the process into acetic add and the soluble dihydiate.
(Walter Crum, Chem. Soc Qu. J. vi 217.)

AcBTATBS OF AjocoKixjic. — a. Normal acetate, 0*H^0* NH^ A white odourless salt,
obtained by saturating glacial acetic acid with dry ammonia. It is very difficult to
obtain it in the cxystcQline form : for its aqueous solution loses ammonia on evapora-
tion, and is converted into the add salt {fi). It is readily soluble in water and alcohoL
Its aqueous solution, known in the Pharmacopda as Spiritue Mindereri, is prepared by
saturating aqueous acetic add with ammonia or carbonate of ammonium. This solution
is tzan^wrent and colourless, with a peculiar odour and cooling pungent taste.
When kept it is decomposed, and becomes alkaline, owing to the formation of carbonate
of ammonium ; by heat it is converted into a solution of the acid salt ($).

$. Acid Acetate, C«H»0".NH*.C«H*0» [or CIPO^.NH'O + CH*0*,HO]. Obtained
as a white crrstalline sublimate when dry powdered chloride of ammonium is heated
with an equal weight of acetate of potassium or caldum, ammonia being given off
nmultaneGiisly. A warm saturated solution of this salt, kept in a dosed bottle de-
posits long needle-shaped crystals. This salt is also obtained in a radiated crystalline
mass, by evaporating the aqueous solution of the normal salt (a). The crystals redden
h'tmus and deliquesce rapidly in the air. They mdt at 76°C. and sublime undecomposed
at 121^. The compodtion <^ this salt is probably that expressed by the above formula.

AcETATB OF Babixtic, CH'O'Ba. — ^Prepared by decomposing carbonate or sulphide
of barium with acetic acid. The solution evaporated at a genue heat yields flattened
prisms containing 2OH'0^Ba + HK), but when cooled to 0° C. it yidds rhomboidal
prisma, iaomorphous with acetate of lead, and containing 2C^*0'Ba + SH'O. The
oystals dried at OP yield the anhydrous salt in the form of a white powder, which,
when strongly heated, is resolved into acetone and carbonate of barium.

AcBTATB OF BisMUTK Separates in micaceous laminae from a warm mixture of
sitnte of bismuth and acetate of potassium. Acetic add mixed with a solution of
nitrate of bismuth prevents the predpitation of a basic salt of that metal .by water.

AcBTATB OF Cadmiuic. — Small prismatic crystals very soluble in water (S t r o m ey er).
According to Meissner and John, it is not crystallisable, but forms a gelatinous mass.

AcKTATB OF Caiciuu, 0*fl"0'Ca, crystallises in prismatic needles, which effloresce
in the air, and dissolve in water and in alcohol. The salt is decomposed by heat
into acetone and carbonate of caldum. A solution of acetate and chloride of cal-
dum in equivalent proportions yields by slow evaporation, large crystals containing
C?H»0«Ca.ClCa + fiH*0.

AcBTATB OF Csuux. — Small needles sparingly soluble in alcohol.

14 ACETIC ACID.

AGRA.T18 or Crboxivic. — Thechrcmoua salt, 2CH*0*Cr + HK) is, prodnoed hj
poTiring protochloride of chromium into a solution of acetate of potassium or sodium. It
rorms red transparent crystals, wbich when moist absorb oxygen yeiy rapidly from the
air, undeigoinff a tarue combustion. The chromie salt is obtained as a ^reen cijstalline
crust, yezy soluble in water, by dissolying chromic hydrate in aoetic acid : the so-
lution scarcely reddens litmus.

AcBTATBS ov CoBALT. — ^Tho red liquid formed by dissolying carbonate of cobalt in
acetic acid, yields by evaporation a red residue which turns blue when heated. It
may be used as a sympathetic inlc. The oxides Co^O' and CoK)* also dissolve in
acetic acid without sejMntbn of oxygen, forming brown solutions. The solution of
the sesquiozide sustains a boiling heaJt without decomposition.

AcsTATBS or OoFFEB. — o. CupToiu AottoU, C^'O'Ccu. [Ccu«>Cu*»63*2]. This
salt sublimes toii^ffds the end or the distillation of normal cupric acetate. According
to Berzelius, it is contained in common green verdigris, and sublimes when that sub-
stance is distilled. It forms soft, loose, white flakes, which redden litmus and have a
caustic astringent taste. Water decomposes it into normal cupric acetate and yellow
cuprous hydrate.

b. Ouprie JaetaUa, — (Berzelius, Pogg. Ann. iL 233; Trait^ iy. 173; Gm. viiL
323 ; Gerh. i 728.) Four of these salts are known, viz. : —

Normal Capric Acetate C«H'0«Chi - C*H*(^ . CuO,

Sesquibasic. . . (0«H«0'Cu)< . Cu«0 - (C^H'O^. {CuOf.

Dibasic . . . (0*HK)«Cu)« . CuK) - C*^»0» . {CuO)\

Tribaaic . . . C»H»0«Cu . Cu«0 - C*H*C^ . \CuOy.

1. The normal salt CH*0<Cu, called also Crystallised Verdigris, Verdet, Criataux
ds Venus, is produced l^ dissolving cupric oxide or common verdLigris in acetic acid, or
by precipitating a solution of nonusil acetate of lead with sulphate of copper : in either
case, the liquid must be highly concentrated and then left in a cool place. It
forms dark bluish-green prisms belonging to the monoclinic system, and containing
2CH»0*Cu + EPO. The ordinary combination is oo P . OP . + P . 2P oo . Twin-
crystals also occur. Batio of the axes : a : 6 : o — 0*6473 1 : 0'6276. Inclination
of the axes a 63^. Inclination of the feuies, oo P : oo P in the plane of the ortho-
diagonal and the principal axis « 108^ ; oo P : OP » 106^ 30' ; OP : 2P oo -
119^ 4'. Cleavage parallel to OP and oo P. The salt is efflorescent, soluble in water,
sparingly soluUe in alcohol, and poisonous like all soluble copper-salts. The ciystals
after drying in vacuo at ordinary temperature^ suffer no fiirther diminution in weight
at 100°, but give off 9'6 per cent, of water between 110° and 140°, then nothing more
below 240° ; between 240° and 260° strong acetic acid, which when rectified yidds 32
per cent of the ccystallisable acid ; at 270° white fumes which condense into white flakes
of cuprous acetate ; and lastly a mixture of carbonic anhydride and a combustible gas.
At 330° the deoompoeition ia complete, and a reddish substance remains consisting
chiefly of metiJlic copper. The solution boiled with sugar yields a red precipitate of
cuprous oxide. Acetate of copper crystallised at a temperature near 8°, yields ciystals
containing 20«H"0'Cu + 6H*0.

2. The basic cupric acetates are contsdned in eammon verdiaris {yert-^te^ffris,
Grunspan), a substance obtained by exposing plates of copper to tne air in contact
with acetic acid, and much used as a pigment and as a mordant in dyeing wool black.
There are two varieties of this substance, the blue and the green, the former oonsiRt'
ing almost wholly of dibasic cupric acetate, the latter of the Besquibasic salt mixed
with smaller quantities of the dibasic and tribasic acetates. The aibasio salt or blite
verdigris is prepared at Montpellier and in other parts of the south of France, by ex-
posing copper to the air in contact with fermenting wine-lees. The wine-lees are
loosely packed in casks together with straw, till they pass into Uie state of acetous fer-
mentation ; and when that is ended, they are arranged in pots covered with straw, in
alternate layers with rectangular plates of copper, which when used for the flrst time, are
previously moistened with a doth dipped in a solution of normal acetate of copper, and
then dried. At the end of three weeks, the plates are taken out ; placed in an upright
position to dry ; dipped six or eight times in water in the course of as many weeks ; and
again left to diy, during which operations the verdigris continually swells up. It is
then scraped o^ the plates again arranged alternately with sour wine-lees, and the
same processes are repeated till the plates are quite corroded. The same compound is
obtained by exposing copper plates to damp air in contact with normal acetate of copper
made into a paste with water. It forms delicate, silky, blue, ciystalline needles and scales,
which yield a beautiful blue powder. Thejr contain 6 at. water, which they give off at
60°, and are then converted into a green mixture of the monobasic and tribasic salt : —

(C?H»OKhi)«.CuK) - C^WOu + (?H»0«Cu . CuH).

ACETIC ACID. 15

Bf xepeated exhaxud<m with water, it is resolTed into the inoolnble tribane ealt,
and a aoliitioii of the normal and sesqnibasic salts :

5(CBW.2Ca«0) - 2(C*H»0».3Cu«0) + 2C*HW.3Cu«0 + C*H«0».Cu«0.

The idlowing table exhibits the oompoeition of several kinds of bfaie Terdigris as

delennxiied by BerselxiiB and by Fhiltips :

PhUUfW.
French. EnglUh.

Calealatkm. B«nelias. CryiuUiaed. Comprested.

2Cii>0 . . 160 . 43*24 . 4334 . 43*5 . 43*25 . 44*25

C?«H«0« . . 102 . 27*57 . 2745 . 29*3 . 28*30 . 29-62

6HH) . . 108 . 2919 . 29*21 . 25*2 . 28*45 . 25-51

Impmities ... • . . • .. .20. . . . 0*62

370 • 100*00 . 10000 . 100*0 . 100-00 . 10000

The setquibagio aesiaie is obtained in a state of puritj by adding ammonia in small
portions to a boiling concentrated solution of the normal salt, till the precipitate is just
redisMslyed, and leaving the solution to cool; or by treating common green Ter-
digris ivi& cold or tepid water, and leaving the filtrate to evaporate. It is then
deposited in bluish scales containing (CrS*OK)u}^ CuH) + 6HK). It gives off half
its water at 60^, and becomes greenish.

Grtai VertUgrtB^ according to Bexzelius, is a mixtare of this salt with small quan-
titiesof the dibasic and tribasic salts, sometimes also containing cuprous acetate and other
impozitles. It is manufactured at Chrenoble bj frequently sprinkling copper-plates
with vinegar in a warm room ; and in Sweden by disposing copper-plates in alternate
layers wiSi flannel cloths soaked in vinegar, tul the green salt begins to form, then
e^osing them to the air and frequency moistening with water. The greenest
kind contains aeoording to Berzeliua, 49*9 per cent, of cupric oxide, and 13-5 per cent,
of water and impurities ; the pure seequibasic salt oontams 43*5 per cent. Ou^O.

The tribaaie acetate, CHH)*6ilCu*0 + HK), is the most stable of all the acetates of
copper. It is obtained by exhausting blue verdi^;ris with water; also by boiling the
aqneoos solution of the normal salt, or byheating it with alcohol, or again by digesting
the aame solution with cupric hydrate. The last method yields the salt in the form of a
green powder; as obtained by the other methods, it forms a bluish powder composed of
fine needles or scales. It gives off its water at 160^, and decomposes at a higher tem-
peratme, yielding acetic add. Boiling water decomposes and turns it brown. The
brown substance thus formed was regarded by Berzehus as a peculiar basic acetate,
containing C^HK)*. 48Cu'0 ; but it is more probably a mixture of the tribasic salt
with excess of oxide.

AiseiaU of Copper and Calcium. CHWCa . <?HK)«Ctt+4H«0. — Obtained by
heating a mixture 1 atom of normal cupric acetate and 1 atom hydrate of calcium
with 8 times its weight of water and sufficient acetic add to dissolve the predpitated
oxide of copper, and evaporating the green filtrate at a temperature between 25^
uid 27®. It forms large, blue, transparent^ square prisms, often converted into
octagonal prisms by truncation of the lateral edges. They effloresce slightly in the
air; fall to powder at 75°, giving off acetic add ; and dissolve readily in water. An-
other ciqzrioo-caldc acetate, C^H)K)<Ca+(G*HH>^Cu). OuK) + 2HK), often exists in
aystaUised Terdigris : its optical properties differ- from those of the normal cupric
acetate.

Aceio-araeniU of Copper, C«HK)«Cu.3AsO«Cu, or OH^CCuO+SiAsO^CuO).—
Sekweinfurt areen, Imperial green, Mitis green, and when mixed with gypsum or heavy
spar, Nettwwier green. Mountain ^een. Used as a piement^ and prepared on the large
seale by mixing arsenious add with cupric acetate and water. 5 parts of verdigris are
made iq> to a thin paste, and added to a boiling solution of 4 puts or rather more of
arsenious add in 50 parts of water. The boiling must be well kept up, otherwise the pre-
dpitate assumes a yellow-green colour, from formation of arsenite of copper ; in that case,
acetic add must be added, and the boiling continued a few minutes longer. The predpi-
tate then becomes crystalline, and acquires the fine green colour peculiar to the aceto-
arKuite. The salt is insoluble in water, and when boiled with water for a considerable
time, becomes brownish and gives up acetic add. Acids abstract the whole of the
oopper, and aqueous alkalis first separate blue cupric hydrate, which when boiled with
the liquid, is converted into black cupric oxide, and afterwards into red cuprous oxide,
an *nr*HnA arsenate being formed at the same time.

AcBTATBS OF Ibok. — o. Ferrous Acetate. When metallic iron or the protosulphide
is dissolved in strong acetic add, and the solution concentrated, small colourless silky
needles are obtained, which dieeolve easily in water, and rapidly absorb oxygen from
the air.

16 ACETIC ACID.

^. Ferric Acetate, — Obtained by diasolTixig ferric hydrate in acetic acid, or by deoom-
posing a solution of ferric snlpbate with acetate of lead. It ia unciyatalliaable and
yery soluble in water, forming a red-brown solution ; soluble also in aloohoL The
aqueous solution, when kept in a state of ebullition for about 12 hours, undeigoes a
jremarkable modification, acquiring a brick-red colour, and remaining dear idien
viewed by transmitted lights but appearinff opaque and opalescent by reflected light.
At the same time, it loses entirely the mettulic taste of iron salts, and acquires that of
▼inegar ; it forms a brown instead of a blue precipitate with feiTocyanide of potassium,
and no longer exhibits the characteristic red colour with sulphocyanides. Traces of
sulphuric or phosphoric acid, or of alkaline salts, precipitate the whole of the iron in
the form of a red-brown precipitate, which, at ordinary temperatures, is perfectiy in-
soluble in acids, even the most concentrated; hydrochloric and nitric acids throw
down a red granular precipitate, which, when p^ectly freed from the acid mother-
liquor, dissolTes easily and completely in water. (P^an de St. Gilles, Ann. Ch.
Phys. p] xlvi 47.)

A mixture of tiie two acetates of iron, called pyrolignite of iron {liqueur deferratUe^
bouillon 9u>tr), is prepared on the large scale oy treating iron with wood-yinegar, in
contact with the air. It is used as a mordant for black dyes ; also for preserving
wood.

AcETATEa OF Lbad. — The normal acetate C'H?0*Pb, or PbO. C^SPC^ (Sugar of lead,
saceharum Batumi, sel de Satume, Bleizucker) is prepared by dissomng oxide or
carbonate of lead in acetic acid, wood-yinegar being used on the laige scale, or by
immersing plates^f lead in yinegar in yessds exposed to the air. It crystallises in
prisms containing 2CH'0'Pb + HH), and belonging to the monodinic system.
Ordinary combination : qo P . OP . oo P oo , sometimes with the face OP predominating,
so as to give the crystals a tabular form. The length of the orthodiagonal is to that of
the dino-diagonal, as 0*4197 to 1. Inclination of the axes » 70^ 28'. Inclination
of the faces: oo P : oo P « 128°; oo P : oo Poo » 116°; oo P : OP - 98° 80' ;
OP: 00 Poo » 109° 82. Cleayage parallel to OP and ooPgo. «The crystals ai«
efflorescent, soluble in 0-59 parts of water at 15°*6 ^60° F.), and in 8 parts of alcohol.
The salt has a sweet, astringent taste, and is yery poisonous. It melts at 75°-5 ; begins
to eiye off water with a portion of its acid a little above 100° ; and is completely de-
hycbrated at 280°. Above that temperature it decomposes, giving off acetic acid,
carbonic anhydride, and acetone, and leaving metallic lead very finely divided and highly
combustible. The aqueous solution is partially decompose by the carbonic acid of
the air, carbonate of lead being precipitated, and a portion of acetic add set free,
which prevents further decomposition. The solution is not precipitated by ammonia
in the cold, but yields crystals of oxide of lead when heated with a large excess of
ammonia. Normal acetate of lead forms crystalline compounds with chloride of lead
and with peroxide of lead.

(Berzelius, Ann. Ghim. xdv. 292 ; Schindler, Brande*s Archiv, xli. 129; Pay en,
Ann. Ch. Phys. [2] Ixv. 238, and Irvi 37; Wittstein, Buchner's Bepert Ixxxiv.
170; Gm. vui. 310; Gerh. i. 736.)

Pour baeic acetatee of lead have been described, vis. :

The sesquibasic acetate . (C«H»0«Fb)*. Pb»0 or (C*lPO^y. (PbOY.

The dibasic „ . (C«H»0«Fb)». Pb»0 or C*H*0^ .(PbOy.

The tribasic „ . C«H«0«Pb . Pb*0 or C^H^O* . (P60)«.

Thesexbasic „ . (C*H»0'Pb)«.(Pb«0)» or C*H*0^ .{PbOy.

All of these however, except the tribasic salt, are of rather doubtM composition.

The seequibane salt is obtained by heating the normal salt till it mdts, and subse-
quently solidifies in a white porous mass. By dissolving the residue inwater and eva-
porating, the salt is then obtained in nacreous laminae containing 2 [(G^'0^)^FbK>]
-¥ BH), It is more soluble in water and alcohol than the normal acetate, and forms
alkaline solutions. (Payen, Schindler.)

The dibasic acetate is deposited in the crystalline form when oxide of lead ^massicot)
is dissolved in the proper proportion in the normal acetate. The ciTstals contain
2 atoms water, half of which is given off at 70°, and the rest at 100° (Schindler.)

The tribasic acetate is obtained in the crystalline form, when a solution of the normal
salt saturated in the cold and mixed with J of its volume of ammonia, is left to
evaporate ; also by digesting 7 parts of massicot in a solution of 6 parts of the crys-
tallised normal acetate. It forms long silky needles, verjr soluble in water, but in-
soluble in alcohol. The aqueous solution becomes turbid on exposure to the air.
According to Payen, the crystab contain 2(C«H«0«Pb . Pb*0) + H'O, but according
to Berzehus, they are anhydrous.

The sexbasic salt is obtained by digesting the solution of either of the preceding
■alts with excess of oxide of lead. A crystalline precipitate is then formed, which

ACETIC ACID. 17

dawlrgB mrinelj in boDing water, and Beparates in silky needles containing
S[(OT»(m)«.(PW0)3 + 8H?0. (Berzelins.)

TIm liquid called GcuUard^B lotion^ lead^viniaar, aoetwn Saiwmi, is a mixtnre of
the upiKsaB sckhitions of these baaic acetates of lead, chiefly the tribasic salt. It is
w^ared bj digesting oxide of lead in acetic acid, or in a solution of the normal acetate.
It is an alkaliTM* liquid which is decomposed by the carbonic add in the air. It pre-
cqutates a laige number of Tegetable snbstances, such as gom-resins, colouring matters,
&& and fiam its power of eoagolating mocus^ is mnch nsed as a lotion for wounds
sndsares.

AcRATB OF LcTHiuii. O^HK)^+ 2 HK). — Bi^ht rhomboldal prisms, deliquescent
in moist air, aohible in lees than a third of their weight of water at 16^, and in 4*6 pts.
of akohol of sp. gr. 0*81 at 14^.

AcsTATB 09 HiiTQAiixeBL — Pals zoso-colonred splinters or small prisms grouped to-
geUier; aofaible in 3 pts. of water.

AcR&TBS OT Mbboost. — Mercurotu oeetote, 0*HK)* Hhg, [Hhg » Hg* » 200], is
obtained by precipitating mereurons nitrate with a soluble acetate. It forms anhydrous
miesieeoiis lainiiup, roanngly soluble in water. Heat decomposes it into metallic mer-
cny, carbonic anhymide, and acetic add.

MercMric .Adxtate, OH"0^Hk [or C^H'C^.H^O], is prepared by dissolving red oxide
of meieazy in warm acetic acid. It czystallises in br&liant micaceous laminse, soluble
in their own weight of water at 10^, and somewhat more soluble in boiling water.
Alcohol and ether decompose it, separating mercuric oxide.

Jeeiate of Mereurttmmonitimf (XBEH)*. (NJB[*Hg) + H^O, is obtained by a^tating
recently pireeipitated mercuric oxide with a solution of acetate of ammonium. It cxys-
tslfises in rhomboidal plates^ tcit soluble in water, insoluble in alcohol. At 100° it
giies offfirom SO to 81 per cent of its weight, and is conyerted into acetate of tetrarner-
cmammomum, CGEH)' (NHg«).

AoRATB OF KiGXBL ciystallises in apple-green prisms, slightly efflorescent^ soluble
IB 6 pta. of cold water, insoluble in alcohol. The solution is decomposed by hydro-
Biiipluxrie acid, which dirows down sulphide of nickel.

AcaETATK OF PoTAssiuic. — Abmfll aeetaU. 0"H«O«K [or C*IP(^JKO], (Terra
foUata Tartari, Arcanum Tartari, Tartarus regeneratus, Bldttererde^ geUaiterte
WemsteinertU). •

This salt esosts in the juices of many plants. It is prepared by dissolving carbonate
of potassinm in acetic acid. VHien brown yinegar is used for the purpose, the car-
bonate of potaasium should be added by small portions, so as to keep the solution
coostantly add. The olgect of this precaution is to avoid the formation of coloured
products by the contact o£ free alkaU with the foreign matters in the yinegar. Pure
acetate of potasdnm is a white salt, difficult to crystaUise, very^ soluble in water and
ddiqueeoent, soluble also in alcohol, and predpitated by ether from the alcoholic
section. Carbonic add gas, passed into a solution of the salt in absolute alcohol,
throws down carbonate of potasdum, and liberates acetate of ethyl. The salt melts
bdow a red heat, forming a limpid oil, which solidifies in an extremely deliquescent
mass on cooling. It respires a very high temperature to decompose it, and then gives
off acetone, empyreumatic oil, and mflammable gases, and leaves a reddue of carbonate
of potassium mixed with diaiooaJL Heated with excess of hydrate of potasdum, it
yielda carbonate of potasdum and marsh gas :

C*H«0«K: + KHO - OH* +C0^«

Heated witii arsenious anhydride, it yidds cacodyL (SeeAnsBNiDBSOFMBTHTL.) Chlo-
rine, passed into the aqueous solution of acetate of potasdum, liberates carbonic anhydride,
and fixrms a bleaching liquid, which however loses its decolorising power on exposure
to the air. When an electric current is passed through a strong aqueous solution of
acetate of potasdum separated into two parts by a porous diaphragm, hydrogen alone
is evolved at the negative pole ; while, at the podtive pole, there is evolved a gaseous
uixtare of methyl and carbonic anhydride, together with acetate of methyl and a small
quantily of oxide of methyl. The prindpal decompodtion is represented hy the
equation;

C«H*0* - CH» + C0« + H,

the acetate and oxide of methyl being secondary products. (Kolbe, Ann. Ch. Pharm.

box. 267.)
Aeid AeetaU or JHaoetate of Totauiim, C»HWK.C^*0«, [or C^B^C^MO +

When the normal acetate is evaporated with an excess of strong acetic acid, this

TOU L C

18 ACETIC ACID.

acid Mlt IB deposited in needles or lamin*, or by fdow evaporation in long flattoied
prisms, apparently belonging to the rhombic system. It is very dehqnescent, melts at
148®, and decomposes at 200<^, giving off crystallisable acetic aoid. On thu property
is founded an easy method of obtaining the crystallisable acid

Diacetate of potassium }fi formed when the normal acetate is distilled with bntroe or
valerianic add ; but neither of these adds decomposes the salt thus produced. Hence,
when butyric or valerianic add is mixed with acetic add, a separation more or lew
complete may be effected by half neutralising the Uquid with potash, Mid distilling. If
the acetic a<ad is in excess, diacetate of potassium alone remains behind, the whole of
the valerianic or butyric add passing over, together with the remainder of the acetic
acid. If; on the contrary, the other add is in excess, it passes over, unmixed with
acetic add, and the residue consists of diacetete of potassium mixed with butyrate or
valerate. By repeating the process a certain number of times, either on the ac^
distillate or on the add separated firom the residue by distillation with sulphuric aad,
complete separation may be effected. (Liebia Ann. Ch. I'Jiw™-!™: ?£^ .

AnhydrJL Dia^tate of Potassium, 2C«H»5«K.C*H»0« [-JK:0. 2C»fl»OT is pro-
duced by dissolving melted acetate of potassium in acetic anhydride at the boiUng
heat, or by the action of potassium on acetic anhydride. Forms colourless needlea
very soluble in water, less deliquescent than normal acetate of potassium. It is de-
composed by beat» giving off acetic anhydride. (Gerhardt, Ann. Ch. Phys. [3]
xxxvii 317.)

AcBTATB OF SiLVBB, C*H*0*Ag. — Obtained by precipitating nitrate of silver with
acetate of sodium. Crystallises from boiling water in thin, flexible lamins ; soluble
in 100 pts. of cold water.

AcBTATB OF SoDiuM, C«HH)«Na [or C^J^O^JfaOJ] Terra foUata tartari crystal-
ligabiUa^ Terre folUe mmirale, — ^Prepared either by dissolving carbonate of so-
dium in acetic acid, or by decomposing acetate of calcium with sulphate of sodium.
Forms large transparent prisms bdonging to the monoclinic system. Ordinary
combination: oo P. [oo Poo] . OP . —P; more rarely with oo Poo, +P, + 2Poo .
Batio of the axes : a\ hie^ 0*8348 : 1 : 0*8407. Angle of the axes ^ 68^ 16'. In-
dination of the faces : oo P : oo P in the plane of the orthodiagonal and prindpal axis
» 95^*30; — P: +P, forming the obtuse edges of the pyramid +Pin the plane of
the oblique diagonal and prmdpal, axis ^ 117^*32; ooP: OP^^ 75^*35. Cleavage
paniHel to OP and oo P. (Oerhardt^ Traits i. 725.) The crystals contain 3 at.

. . p -^ ^ ,. o , boiling

heat, contains 0*48 pts. water to 1 pt. of salt, and boils at 124^*4. The salt is less
soluble in alcohol, it has a bitter, pungent, but not disagreeable taste.

Acetate of Stsontivx crystallises like the barium-salt in two different forms, con-
taining different quantities of water. The salt deposited at 15^, contains 4*23 p. c.
water (? 4C'H'0*Sr + H'O), and that which is deposited at low temperatures con-
tains C^"0^ + H'O. The latter forms prisms belonging to the monoclinic system,
<»P: ooP«124<'54'; ooP . ooPoo « 107° 33' ; OP : P oo -1630-12. Cleavage
indistinct, paralld to oo Poo .

Acetate of Tnr. — Boiling acetic add dissolves tin slowly, with evolution of hy-
drogen ; the hydrated protoxide dissolves easily in the boiling add, and the solution
evaporated to a syrup and covered with alcohol yidds small colourless crvstals. Hy-
drated dioxide of tin also dissolves in acetic acid, and the solution yields a gummy
mass when evaporated. Bichloride of tin forms a crystalline compound with glacial
acetic acid.

Acetate of XTrahiuic. — Uraruma Acetate^ obtained by evaporating a solution of
oxide in acetic acid, crystallises in green needles grouped in warty masses.

Uranie Aoetate, or AcetaU of Uranyl, C«H«0«(UK))* [ « C*H*0*.lPO^, is ob-
tained by heating uranie nitrate till it begins to evolve oxygen, dissolving the yellow-
ish red mass, which still contains nitric add, in warm concentrated acetic aad, and
evaporating to the crystallising point ; all the nitric add then remains in the mother
liquid. From a very concentrated, or from an add solution slightly cooled, the salt
separates in beautifal rhomboi'dal prisms, C*H*0»(U*0) + HK), belonginff to the mo-
nodinic system ; boiUng water decomposes them with separation of uranie hydrate, but
the solution yields the same crystals by evaporation. A more dilute solution cooled
bdow 10° deposits square-based octahedrons containing C*H'OXn'0)-f | HK), or

* Uranyl, U*0, U a moDatomlc radtcle,*8appoted to exist In the uranie compoundi. f See Dianicii.)

ACETIC ANHYDRTOE. 19

fC^SPO^(VH>)+SBK>. They ave off i of their witer Bt 200^^, and the rest at 275^,
Irnnag the yeDowiah red anhydrous aalt.

Unoie acetate comhinea with tbe acetates of the more basic metals, formixig double
aeetates. The ammomttm, poiasaium, and sodium salts are obtained by adding the
weMttM of the eaxbonates to a solntion of nranic acetate^ till a precipitate is formed
flouiatiDg of a uranate of the alkali-metal, rediasolTing this precipitate in a slight
eieesi of aeetie acid, and cooling the solntion till it crystallises. The other double
Mits of this group are obtained h^ boiling the carbonates with nranic acetate, tiU the
vhole of the nranic oxide is precipitated, redissolving the precipitate in acetic add,
and emporating. The tead and cadmium salts consist of 1 at. of nranic acetate combined
vith I at of the monobasic acetate, their formnk being CH«PbO> . C*H*(UK))0*
+ tHH} and C*HH)dO*.C*H»(tJK))0« + | H*0. All the rest contain 2 at. nranic
aeetiAe with 1 at. of the monobasic metol, their general formula being CHIiiO'.
3(^H'(nK))0* + nBH). Host of these salts crysUllise with facility, the potassium
and sihfr udts in the quadratic S3rstem ; the somum salt forms regular tetrahedrons.
The strontium and calcium salts are yery soluble in water, and difficult to czystaUise.
The sodhim salt is anhydrous ; the rest contain water of crystallisation. (Worth eim,
J. pr. Ghem. Trrfr 209; Weselsky, Ghem. Ghiz. 1858, 390.)

AcBt^TB OF Yttbiux, Oil*0*Y + H*0. — Bhombo'idal prisms with trihedral snm-
mita They are permanent in the air at ordinaijr temperatures ; ^ve off their water,
and become opaque at 100^ ; diBsolve in 9 pts. of cold water, and in a smaller quantity
of boiling water; also in alcohol (Berlin.)

AsxtxTB or Znro, C*H»0*Zn + |H*0,or2C«H»0«Zn + 8H«0 [ = CiPZnO«+ 3HO].
— Obtained by diasolTing either the metal, the oxide, or the carbonate in acetic ado.
ClyBtanises in nacreous efflorescent laminse belonging to the monodinic system (K opp's
EiyrtiJkgraphie^ p. 310). Ordinary combination : OP. ao P. « Poo . + P . + 2Pao , tne
&ee OP predominating, a: 6 : c » 0*4838 : 1 : 0'87. Indination of axes » 46^30'.
ladioation of feces, ooP: oo P in the plane of orthodiagonal and principal axis =
1120 36'; ooP.OP-112<» 28'; OP: ooPoo =118° 30' ; OP: Poo ==80°; OP: +P
a 750 3()r^ CleaTBge paralld to OP. The salt dissolyes yery readily in water. At
100° it melta, grves off its water with a littie acetic add, then solidifies, and does not
Uqueff again tul heated to 190° or 196°, at which temperature anhydrous acetate of zinc
saUimes in nacreous scales. At higher temperatures, complete aeoomposition ensues.
(Larocque, Becneil des Tray, de la Soc. Fharm. 1847-64.)

ACVm ACKDff CUBSTIT U VIOIV VSOSVCTS OF> — ^The following adds
(which will be more folly described hereafter), are deriyed firam acetic add by substi-
tstion:

'^""^'^ "^"SJo

Bihiomacetie add ^^"^^lo

CUoncetieadd ^^^^^^^^jo

TrichUnacetie add . . • • . Hi^

lodaoeticadd . . . . . ^^^HC^

cwio;

0*HI«Oi

IHniod-flcetio add ..... ^'^nc^

Thiaoeticadd ^^'^js

The brominated and ehlorinated adds are produced by the direct action of bromine
and dilotine on acetic add ; the iodated ados by the action of iodide of potasdum on
bromacftate and difaromaoetate of ethyl ; and thiacetic add by treating glacial acetic
add with pentasulphide of phosphoros (p. 11). All these adds are monatomic,
Uke aeetie acid itself conespond to it in nearly all their reactions, and are formed
vpon. the same type.

ACmna Arnnsna. CHH«0* » (G>H*0)*0. Anhydrous Aoeiie acid;
Oxide of Acetyl : Aeetaie of Acetyl.— {QeThArdt, Trait^ i. 711.)

This compound is obtained : 1. By the action of ^xychloride of phosphorus, P0C1\
00 acetate ^potasdum. The acetate depriyed of water by fusion, is introduced into
a tubulated retort, and the o^chloride of phosphorus admitted through tiie tubulus,
drop by drop. A yudent action takes placie, the mixture becoming yery hot without

0 2

20 ACETIC ANHYDRIDE.

the application of external heat, and a liquid distilB over, which is the chloride of
acetyl, while tribaaic phosphate of potassium remains in the retort:

SCWKO* + POa« - PO*K« + 3(C*HH).C1).

If now this liquid be ponred back again three or four times into the retort» so that
it may remain for some time in contact with the acetate of potassium, that salt being
also in excess and pretty strongly heated, a farther action takes place between the
acetate of potassium and the compound C'H'O.Cl, the result of which is the forma-
tion of acetic anhydride : thus,

C«H»KO» + C«H«0.a - Ka + C^H«0«.

The acetic anhydride enters into combination with the acetate of potassium, and a
considerable degree of heat is required to destroy this oom^und and cause the anhy-
dride to distil over. The distillate is more or less contaminated with acetic acid and
chloride of acetyl ; but on redistilling the crude product, these impurities pass over at
the commencement, before the temperature rises to IZ7^'6, after which the pure
anhydride distils over. — 2. By the action of terchloride of phosphoms on acetate of
potassium. When the liquid chloride is added drop by drop to the acetate of potas-
sium (about 1 pt PCI' to more than 2 pts. of the acetate), the action begins without
application of heat, and chloride of acetyl, amounting in quantity to about half the
chloride of phosphorus used, distils over mixed with a small quantity of chloride of
phosphorus. On heating the residue after this action has ceased, acetic anhydride
distik over free from chloride, and in quantity equal to about a third of the chloride
of phosphoms used. The product contuns a small quanti^ of a phosphorus-compound,
which causes it to impart a brownish colour to nitrate of silver ; but it may be freed
from this impurity by a second distillation with acetate of potassium. — 3. By the
action of chloride of benzoyl, CHH).G1, on Aised acetate of potassium. The first
products of the action are cmozide o^potas8ium and acetate of benzoyl, CHK)* :

c»HK). CI + o^mco* - Ka + otpoI ^•

But if the acetate of potassium is in excess, and the mixtore is heated somewhat
above the temperatore at which the original substances act upon each other, a farther
action takes pUoe, and a colourless liquid distils over, which is acetic anhydride, while
benzoic anhydride remains in the retort in combination with benzoate of potassium.
These new products are formed by double decomposition between 2 atoms of the
benzoic acetate :

gjC'HK))^ _ C»HK)) Q . C«H«0)o
'^IC'H'Oj" " C'HK)} " + C^'Op

4. By Hie action of chloride of acetyl, CH'OCl, on dry benzoate of sodium. The reaction,
which takes place without the aid of heat, is precisely similar to the preceding.

Acetic anhydride is a colourless, veiy mobile, strongly refracting liquid, having a
powerful odour, similar to that of the hydrated acid, but stronger, and recalling at the
same time that of the flowers of the white-thorn. Sp. gr. 1*073 at 20^*6, which is
nearly that of the hydrated acid, C^^O' + HK), at its greatest density. Boiling
point 137^*5 under a pressure of 760 mm. Vapour density » 3'47 (by calculation 3*581
for a condensation to 2 volumes).

Fuming sulphuric acid becomes heated by contact with acetic anhydride, carbonic an-
hydride being given off and a coi\jugated acid produced, which forms a gummv salt with
lead. Potassium acts violently on acetic anhydride, evolving a gas whidi does not
take fire if the potassium be introduced by small portions at a time. The liquid, after
a while, soUdifies into a mass of needles, consisting of a compound of acetic anhydride
with acetate of potassium (p. 33). An oily substance is also produced, having a veiy
pleasant ethereal odour. Finely divided jpine acts upon acetic anhydride in a similar
maimer, but less energetically, and only when heated in the water bath ; hydrogen
gas is then ffiven off, and a soluble salt formed, which is deposited in microscopic
crystals on the surface of the metal, and greatly retards the action. On satorating
the excess of acetic acid in the residue with carbonate of sodium, the ethereal
odour above mentioned is perceived. The hydrogen evolved, if collected immediately,
has the same odour, bums with a bluish fiame, and the product of the combustion
renders lime-water turbid ; but after passing through potassium, it is inodorous, and
when burnt vields nothing but pure vapour of water.

Acetic anhydride does not combine immediately with vxUer, but when poured into
that liquid, fiills to the bottom in oily drops which dissolve after a while, if the liquid
is heated or agitated. It absorbs water from the air, and must therefore be kept in
well closed vessels.

ACETIC ETHEES. 21

Aeetie anhydride eombingi -with dldekjfdes. With ordisary aldehyde, it fomiB a
hqind oompoaiid, C'H'O'. OH^O (G-enther), and a similar oomponnd with TaleraL
CHW. G^'*0 (Guthrie and Kolbe) ; also irith bitter ahnond oiL(Geiither).

AciTOBXsiaoM^ or JtenoACOBnc Amhidbidx, OH"0* >■ nrg^sofO. AeetaU of

Betuoil, BenzoaU of Asetyl, — Obtained by the action of chloride of acetyl on benzoate
of ■odinm. HeaTy oil smelling like Spanish wine. Neutral to litmns. £)il8 at 120^ C.
and is lesolyed into acetic and benzoic anhydrides (p. 35V Besolved into aeetie and
bGisDie adds by boiling with water, and more quickly witii alkalis.

AcRO-GiKXAiac AiTHTDRiDB, G*HH).CfH'0.0. Acetate of Cinnamyl^ jv. — A yery
zostaUe product obtained by the action of chloride of acetyl on dnnamate of sodium.
Oil hearicr than water, something like the preceding compound.

AcRO-cuxDOC Afstsbtob, CHK> . C**H"0 . O. Acetate of Cumyl, — Besembles
the neeeding eompoonds. In the moist state it quickly turns add, and yidds beautiful
laBiiufr of enminic add, the odour of acetic add Ixecommg perceptible at the same time.

AdTO-BAXJCTiJC Akhtdbidb, OHH) . C*H*0'.0. Acetate of Sali^l, ^c— Salicylate
of sodium n strongly attacked by chloride of acetyl, eyen at ordinaiy temperatures,
the mixture lique^ring at first, but becoming perfectly hard in a few seconds. The
product diflsolyes with efferyescence in carbonate of sodium, the uohydride being con-
verted into acetate and salicylate of sodiunu (Gerhardt, Trait^ ilL 319.)

ACBTIC JTHBIf These compounds are the acetates of the aloohol-radides,
and may be diyided into the following groups :

AcsTATn OF AixTL, (?HH).C*H*. — ^Prepared by treating acetate of silyer with iodide
(^ allyl, and rectifjring once or twice oyer acetate of silyer. It is a colourless liquid,
lighter than water, hftying a pungent, aromatic odour, and boiling between 98^ and
100^. Boiling potash decomposes it into acetate of potassium and allyl-alcohoL
(Oahonrs and Hofmann, Chem. Soc Qu. J. z. 322.)

AcBTATB OT Amtx., or AcsTATH o» pBNTYL, CH'O'.O'H". — This compound is
slowly produced when amylic alcohol is left in contact with acetic add, and may be
ennyeniently prepared by distilling 2 pta. of acetate of potassium, or 3 pts. of de-
hydrated acetate of lead, with 1 pt^ of strong sulphuric add, and 1 pt. of amylic
alcohol, agitating the distillate witn milk of hme, then dehydrating oyer chloride of
ealdum, and recnfying. It is a transparent, colourless liquid, of sp. gr. 0*8572 at 21^,
and boiling at 133*3^, under a pressure of 27" 8'", with a platinum wire immersed in
it Tapoinvdensity 4*458. Odonr ethereal and aromatic, like that of acetate of
cthyL It is insoluble in water, but dissolyes in alcoholy ether, and fuael oil. It is
decomposed yeiy slowly by aqueous potash, but quickly by alcoholic potash, yielding
amylic alcoh<d and acetate of potasdum. Chlorine passed through it at 100^, conyerts
into di-chlorifuUed acetate of amyl, CH^CIK)^ and this, by the action of chlorine in
sunahine, is conyerted into a higher chloiine-compound.

AcsKATB OF Benzti^ C^H'O'.CH*. — ^Produced by treating 2 yol. benzyl-alcohol with
a mixture of 1 yoL sulphuric add and 4 or 5 yol. acetic add, or by boiling chloride of
benzyl with alcoholic acetate of potassium. Colourless oil, heayier than water, and
haying a yery agreeable odour, like that of pears. Boils at 210^ C. Boiled with
potash-ley, it yidds acetate of potassium and benzylic alcohoL (Cannizzaro, Ann.
Ch. Pharm. Ixxxriii 130.)

AcxTATB OF Ethtl. Aeetto ether, EthyUo Acetate^ Eamgdtker, Eeewfumhtha, Ea-
meaures JEtJ^loxyd, Ether acitique. C*H«0* = C«H»0*.0»H». or &IP(^.O^H*0.
(Lanragais, Joum. d Scayans, 1759, 324; Th^nard, M^. d'Arcueil, i 153;
Dumas and Boullay, J. Pharm. xiy. 113 ; Liebig, Ann. Ch. Pharm. y. 34 ; -r^r.
144 ; Gm. yiiL 493 ; Gerh. i. 743). — Disooyered by Lanragais in 1759. It is formed
by heatinff alcohol with acetic acid, or with an acetate and strong sulphuric add,
or by A\mtt\\\T%^ ethyl-sulphate of calcium or potassium with glacial acetic add The
best mode of preparing it is to distil a mixture of 3 pts. of acetate of potasdum,
3 ptsL of absolute alcohol, and 2 pts. of sulphuric acid ; or 10 pts. of acetate of sodium,
6 pts. of alcohol, and 15 pts. of snlphunc add ; or 16 ^ts. of dry acetate of lead,
44 pts. of alcohol, and 6 pts. of sulphuric add. The add is first mixed with the
alooho], and the liquid poured upon the salt reduced to fine powder. The mixture is
then distilled to mryness, the heat being moderate at firsts but increased towards the
end of the process. The product is purified by digesting it with chloride of ealdum
and ractiiying the decanted liquid

c 3

22 ACETIC ETHEES.

Ajoetate of ethyl is a ooloorless liquid, haying a pleasant ethereal odour. Sp. gr.
0-9 1 046 at 0° (K o p p) ; 0*93 2 at 20^ (G 6 s s m a n n). Boils at 74^*3, when the barometer
stands at 760 muL (Kopp). VapoiuHdensity 3*06 (Boullajand Dnmas). It dis-
solves inll or 12 pts. of water, at ordinary temperatures (Mohr, Arch. Pharm.[2] Izr. 1),
in all proportions of idcohol and ether. It hwrna with a yellowish flame, giving off the
odour of acetic acid, and leaving that add in the liquid state. It is permanent when
dry, but in the moist state gradually decomposes into alcohol and acetic add. The same
decomposition takes place more quiddy under the influence of alkalis. Heated with
strong sulphuric ado, it is resolved into oxide of ethyl and acetic add. Hydro-
chloric acid converts it into acetic add and chloride of etii^l.

Action of Chlorine on Acetate of Ethyl, (Malaguti, Ann. Ch. Phys. [2] xx.
367; ibid. [3] xvi. 2, 68; Leblanc, ibid. [8] 197; Cloes, ibid. [3J xvii 804.,—
When acetate of ethyl is introduced into a bottle flUed with diy chlorine gas, in the
proportion of 1 atom acetate of ethyl to 8 atoms chlorine, and the action allowed to
go on, first in the shade and afterwards with continually greater exposure to sunshine,
a number of chlorinated compounds are formed in which 2, 3, 4, 6, 6, 7i and 8 atoms
of hydrogen in the acetate of ethyl are successivdy replaced by an equal number of
chlorine-atoms. It is however not always possible to obtain the particular compound
required, the compounds C*H*01K)*, C*HCrO', and C*C1"0«, being the only ones that
can be produced with certainty. Other products are also formed, among which are
acetic add, trichloracetic add, and sesquichloride of carbon. If the acetate of
ethyl is at once exposed to sunshine in contact with chlorine, an eiqplosion takes place,
attended with deposition of charcoal.

Diohlorinated Acetate o^ Ethyl, C*H*C1'0*, is the product obtained when the acetate
of ethyl is kept cool and in the shade during the action of the chlorine. On distilling
the product to separate the more volatile portions, till the boiling point rises to 110^,
washing the brownish residue with water, and drying it over lime and sulphuric add,
the compound is obtained as a transparent colourless oil, of sp. gr. 1*301 at 12^. It
smells somewhat like acetic add, has a peppery taste, and produces irritetion in the
throat. It is slowly decomposed by water, yielding hydrcdiloric and acetic adds.
C*H«aK)*+ 2HK) - 2C*H*0«+ 2HC1; slowly also by aqueous potash, but quickly by
alcoholic potash, yielding aoetete and chloride of potassium. (Malaguti)

THohlorinated Acetate of Ethyl, C«HK)1K)*, was obtained by exposing the di-
chlorinated compound for some time to the action of chlorine in a bottle, cov^ed at the
upper part with black paper, so that the light fell only on the lower part of the liquid.
It resembles the preceding compound, but cannot be distilled without alteration. It
18 isomeric with trichloraoetate of ethyl, CK21H)'.CH*. See Tbichlobagbtio Aom.
(Leblanc)

Tktrachlonnated Acetate of Ethyl, C*K*CI*0\ was obtained by exposing the di-
dilorinated compound to the sun in autumn, in bottles filled with dry cnlorine. After
rectification, washing, and drying, it forms an oil of sp. ^. 1*486 at 26^. It is de-
composed by potash, yielding diloride, acetete, and tndiloracetato of potassium
(Leblanc). The five-chlorine compound, C^H'Cl^O', was obtained in the same
manner as the preceding, excepting that the gas above the liquid was protected from
the action of the solar rays ; tne etx-chlorine comoound 0*H'C1*C, by exposing the
last compound to the sun for two days, in a bottle fiUed with dry chlorine. Sp. gr.
1*698 at 23*5. The eeven-chlorine compound, C^HCl'C?, was produced by exposing ue
dichlorinated compound in bottles filled with dry chlorine, to the sun for some months
in winter. It forms rather soft crystals, insoluble in water, sparingly soluble in cold
alcohol of ordinary strength, very soluble in ether. They melt ).*elow 100^, but do not
appear to be volatile without decomposition. An oilv Uquid isomeric with this com-
pound, and having a sp. gr. of 1*692 at 24-6°, is obtamed by exposing trichloracetete
of ethyl to chlorine in the shade, as long as any action goes on. (Leblanc)

Perchlorinated Acetate of Ethyl, O^OIK)', is prepared by exposing di- or tri-chlori-
nated acetate of ethyl to the brightest summer sunshine, and at the same time heating
it to 110°; even then the substitution takes ^lace veiy slowly (Leblanc). The pro-
duct is distilled in an atmosphere of carbonic add, to remove free chlorme. It is a
colourless oil, which remains liquid at a few degrees below (P, and has a strong pungent
odour like that of chloral. Sp. gr. 1*79 at 25°. Boils, with partial decomposition, at
245° (Leblanc). When its vapour is passed through a tube filled witii fragments of
glass, and heated to 400°, it is partly converted into the isomeric compound chlor-
aldehyde, C*C1K)' (Malaguti). In contact with water or moist air, it is gradually
decomposed, yielding trichloracetic and hydrochloric acids. A similar decomposition
is instantly produced by strong aqueous potash (Leblanc) :

C*C1K)« + 2H»0 « 2C«HC1»0« + 2HCL

ACETIC ETHERS, 28

Ajnmonia, either paaeons or diaaolred in ^water, acta strooglj on tiid oompound, pro-
dndng sBl-ammonue and trichloreeetamide (Malagnti) :

C*C1«0» + 2NH« « 2Ha + 2C*H»Ca«N0
WUh absolute alcohol, the compound becomes strongly heated, and ia completely oon«
Toted into hydiodilorie add and trichloiacetate of ethyl (Malagnti) :

OCPO* + 2C«H«0 - 2HC1 + 2C*HH:aH)«.

When exposed for a long time to the action of chlorine, it yields crystals of sesqni-
chkffide of carbon. (Leblanc)

Perdilonboetie ether may be regazded as a tnehloraeetate of pentaeldorethyl^
G^C^H)*. CH}P ; and in like manner, all the preceding compounds which contain more than
3 atoms of dilorine, may be riewed as trichloracetates of e^l-radides, in which the H
is more or leas replaced by Q: e.y. pentachloracetic ether, C*]a"Cl*0« = C*C1»Q».C^"CI«.
Some of tbeoa ai^)ear however to oe susceptible of isomeric modifications.

AcBz^n OF Mbthtx., CH*0* « 0^*0 . OH'. Methtflic Acetate, Essiasaurer
HoUSiher. (Dumas and P^ligot (1836), Amu Ch. Phys. lYiiL46.->Weidmann
and Sehweiaer, Poffi. xliii. 693. — H. Kopp, Ann. Ch. Pharm. It. 181. — Gm. viii.
484; Qerh. L 741.)-pThis compound occnzs ui crude wood-yinegar (Weidmann and
Sehweixer). The Uqnid called Mther lignotua or Spiritus pyroaceticuB appears to be
impare aoetate of methyL

FreparaUon. — 1. Two pts. of wood-spirit are distilled with 1 pt of glacial acetic
add and 1 pt. solphuric add; the distiUate is shaken up with chloride of «*ftH»T"',
the acetate of m^^l tiien rising to the top ; and this product is freed from sul-
pfanoas add hj agitation with quicklime, and from wo<Ml-spirit by 24 hoTin' con-
tact with chlonde of caldum, which takes up the latter substance (Bumas and
Peligot). — 2. When 1 port of wood-spirit is distilled with 1 pt. acetate of potas-
simn and 2 pta. of solphunc add, acetate of methyl passes over first) then sulphurous
add, aeedc add, methyl, and a small quantity of methylic sulphate. The first recdyer
most therefore be removed as soon as sulphurous add begins to escape ; its contents
sfaakoi up with water; and the s^wrated ether rectified over chloride of calcium and
quicklime (Weidmann and Schweiser). — 3. A mixture of 3 pts. wood-spirit, 14^
pis. dehydrated aoetate of lead, and 5 pts. sulphuric add is distilled ; the distillate
IS shaken up with milk of lime ; and the stratum of methylic acetate which rises to the
toi&oe is dehydrated by repeated treatment with chloride of caldum, then decanted
from the lower liquid, and rectified. (H. Kopp.)

Aoetate of meuiyl is a colourless liquid, having a venr agreeable odour, like that
of acetate of ethyl, sp. gr. 9'0085 at 21*^; 0-9662 at (P (Kopp). Boiling point, 663^
under a pressure of 760 mm. (Kopp, Pogg. Ann. bdi 1) ; bSP under a pressure of
762 mm. (Andrews, Chem. Soc (&. J. i 27). Vapour-dendty 2*663 (Dumas and
Peligot), by calculation 2'664. Index of refraction 1*3676. (Delffs, Pogg. Ann.
Wnri 470.)

Aoetate of methyl diasolvei in water, and mixes in all poportions with alcohol and
ether. The aqueous solution sufif^ but little decomposition by boiling. Solutions of
caostie alkalis convert the compound into wood-spirit and an alkaline acetate. When
poured on pulverised soda^limei, it is decomposed with violence, yielding a mixture of
acetate and formate of sodium, and giving o£f hydrogen. In contact with strong sul-
phuric add, it becomes heated, gives off acetic add, and forms methylsulphuric add.
with chlorine it forms a number of substitution-products.

DieUormaied Acetate of Methyl, G^H}1K)*, is formed by passing diy chlorine gas
through aoetate of methyl, assisting the action by a gentle heat towards the end. It
is pnnfied like the corresponding ethyl-compound. It is a colourless neutral liquid,
having a pungent odour ; its taste is sweet at first, but afterwards alliaceous and burning.
8p. gr. 1*26. Boils between 146^ and 148^, but begins to decompose and give off
Hsmes at 138^. It bums with a yellow fiame, edged with green at the bottom. It is
decomposed slowly hj water, quickly by aqueous potash, and violently by alcoholic
potash, yielding formic, acetic, and hydrochloric adds :

C»H*C1K)> + 2H»0 - CH»0« + C«H*0« + 2HCL

This compound is isomeric if not identical with dichlorinated formate of ethyl.
(MaJaffuti, Ann. Ch. Phys. [2] Ixx. 379.)

TricUorhuLUd Acetate of Methyl, C»H»C1H)*, is obtained by pasdng chlorine very
slowly into aoetate of methyl, as Ions as any decomposition takes place, and purifying
the product by repeated fractional distillation. It is a colourless oil^ fiquid,. heavier
than water, boiling at 146^, and distilling without decomposition. It is decomposed by
caustic pota^, yielding diloride and formate of potassium, and chtoromethylate, CHCl :

(7H»a"0» + 2K«0 « 2KC1 + 2CHK0« + CHC1.

0 4

24 ACETIC ETHERS.

It 10 iflomerio bat not identical with trichlonCetate of methyl, CKjlHy. CH*, produced
hy distilling -wood-spirit with trichloracetic acid and a small qosintity of sulphuric
acid. (Laurent^ Ann. Ch. Phjs. [2] Ixxiii. 26.)

PerohlorituUed Acetate of Methyl, CHUl'O^ (Cloez, Ann. Ch. Fhys. [3] zviL 297,
311.)— This componnd, which appears to be identical with perchlorinated formate
of ethyl, is proanced by exposing acetate of methyl to the action of chlorine in
sonshine, as long as the gas continues to be absorbed. It is a colourless liquid, having
a suffocating odour and a disagreeable taste, which soon becomes intolerably add, from
decomposition. Sp. gr. 1*705 at 18^. Boils at about 200^, with partial decomposition.
It is quickly decompmed by water and by moist air, yielding hydrochloric^ carbonic, and
terchloracetic acids :

C«C1W + 2HH) = 8HC1 + C0« + C*HCI»0«.

Similarly by the fixed alkalis in solution. With aqueous ammonia, it forms tri-
chloracetamide, together with chloride and carbonate of ammonium:

C«C1«0« + 6NH« + 2H«0 - N.H«.CK)1«0 + 8NH*C1 + CO" (NHV

With alcohol it forms hydrochloric add, trichloracetate of ethyl, and monochlori-
nated formiate of methyl :

C*a«0« + 2C*H*0 - 2Ha + C«C1«0«.C«H» + C«H*C10«

Similarly with wood-spirit it yields trichloracetate of methyl, and monochlorinated
formate of methyl.

The Tapour passed through a red-hot porcelain tube is decomposed into chloraldehyde
and chloro-carbonic oxide (phosgene) gas :

C«C1»0« - (yci*o + COCl\

AcBTATB OF OcTTL, CHK)'. C^E}", — Prepared by possinff hydrodiloric add gas
through a mixture of acetic add and odylic (caprvlic) alcohol ; or, better by Ss-
tilling a mixture of octylic alcohol, acetate of sodium, and sulphuric add. It is a
liquid of yezy agreeable odour, insoluble in water, boiling at 190^. (B ouis, Compt. rend.
xxxvuL 937.)

AcET^TB OP pHxanrz^ CH'O.CH*. — Produced by the action of diloride of acetyl
on acetate of phenyl : also by boiling an alcoholic solution of phosphate of phenyl
with acetate of potassium. Alter all the alcohol has eyaporated, the temperature of the
mixture rises rapidly, and acetate of phenyl distils oyer in the form of an oily liquid.
It is heayier than water, and slight^ soluble in that liquid. Boils at 190^. Boiling
potash decomposes it, yielding acetate of potasdum and hyctate of phenyL (S c r ug h am,
Chem. Soc. Qu. J. yii. 241.)

AcBTATB OP Tbtbtl, or AcBTATB OP BuTTL, CHK)*. C*H». — Obtained by heating
iodide of tetryl with a slight excess of yery drf acetate of silyer in a sealed flask
at 100^: — also by distilling in an oil-bath equiyalent quantities of acetate of po-
tasdum (recently ftised) and tetryl-sulphate of potassium :

C«H»0« K + SO*.KC*H» « C«H«0«.C*H» + SO«.K»

AcBTATB OP Tmttl, or AcBTATB OF pEOPTL, CHW.CH^. — Obtained by distilling
(propylic) alcohol with a mixture of acetic and sulphuric add. Besembles acetate
of ethyL Boils at 90<^. (BertheloU

It is a colourless liquid of agreeable odour. Sp. gr. 0*8845 at 16° C. Boils at
114°. Vapour-density 4*073 (calculation, 4*017). iJ^iling potash conyerts it into
acetate of potassium and tetiylic alcohol.

a. Biatomlo Aoetlo BUien* (Glyeolie Ethers,) — ^These compounds are deriyed
from the diatomic alcohols or glycols by tne substitution of 1 or 2 at. acetyl (C'H'O » Ac),
for 1 or 2 at h^dr(^en. They are related to the glycols in the same manner as the
monatomic acetic ethers just described are related to the monatomic alcohols. The
following haye been obtained : —

MonoaceUte of Ethylene ^^"^h'^O*
Diacetate of Ethylene ^^a ^' \ 0*

Diacetate of Propylene ^^^*^'' \ 0*

Diacetate of Butylene ^^^' \ O"
Biacetate of Amylene ^^^^ 1 ^'
Diacetate of Benzylene ^^*J[' I O*

The diacetates are produced by the action of acetate of silyer on the chlorides,
bromides, or iodides of the seyeral diatomic alcohol-radides : e. g.

ACETmS. 35

BroiDiite of S at. acetate of Diaeetate of

ctlijlene. aUTor. ethylene.

M Qooaoetate of ethylene is obtained by heating acetate of potaflsinm with an alco-
bolie sofaition of bromide or chloride of ethylene, or by heating in a sealed tabe a
nuxtnre of 1 at. hydrate of ethylene and 1 at. acetic anhydride :

«'^T|o.MC^)..o - ^^y^So..<^5o

An these oompoonds when distilled with potash are converted into the oorre-
nonding diatomic alcohols. They will be more fully described in connection with
these scTeral alcohols.

S. TMatonDte beetle BChersi Aoetliis. (Berthelot, Ann. Ch. Fhys. [3]
Z1L277; 0m.iz.496; Gerh. iiL 950; Berthelot andBe Luca» Ann. Ch. Phys.
[3] liiL 433). — Compoonds obtained by the nnion of 1 at. glycerin, C^HK)*, with 1,
is or 3 sL acetic add CH^O', with elimination of an eqnal nnmbeor (riP atoms of water.
They may be reeaided as glycerin, CHK)*.H', in which 1, 2, or 3 at. hydrogen are
rqplaeed by aceM.

MonoacetiH^ G*H>K>« » G^*0".H'.O^H'0, is produced by heating a mixture of
gjyoeriu and glacial acetic add to 100° for 24 hours. SUght traces are also formed
by mere contact of the liquids at ordinary temperatures. It is a neutral liquid, haying
a slightly ethereal odour. Sp. gr. 1*20. Mixed with half its bulk of water, it forms a
dear liquid, whidi becomes turbid on the addition of two or more Yolumes of water;
but the aoetin does not separate from it, and the emuldon continues opalescent eyen
after the addition of a large quantity of water. Treated with alcohol and hydrochloric
add, it forms gjlycerin and acetate of ethyL It mixes with ether.

Diaeetm, also called Jeetidin, (rH«0» = C«H*0».H.(C»H»0)« « C»H»0« + 2CPH*0«
~2HH), is obtained by heating gladal acetic add with excess of glycerin to 200^ for
3 hours; by heating the same two liquids together at 27S°; by heating glycerin to
200° with acetic add diluted with an equal bulk of water ; and by heating to 200° a
mixture of 1 pt of glycerin with 4 or 5 pts. of acetic add. It is a neutral odori-
ferous liquid haying a sharp taste; sp. gr. about 1-85. Boils at 280°, and distils with-
out alteration. Assumes a yisdd consistency at— 40°. It becomes slightly add by
prolonged contact with air. 100 pts. of it saponified with baryta, yield 52*4 pts. of
^lyoerin and a quantity of acetate of barium corresponding to 66*4 pts. of acetic add ;
calculation requires *52'3 glycerin and 68'2 acetic add. With alcohol and hydro-
dilorie add it yields glycerin and acetate of ethyL It dissolyes in ether and in benzoL

Tnaatin, frH"0* «C*HH)».(C?H»0)» - 0»H»0« + 3C«H*0« - 3 BPO. — Obtained

iponified

43-1 glycerin; by calculation it should be 82*6 acetic add and 42*2 glycerin. It is^
iDBoluble in water, but soluble in dilute alcohol.

A compound of acetic add and glycerin, probably triacetin, appears to exist in cod-
liyer oil (De Jongh, Berz. Jahresber. 1843), and in condderable quantity in the oil
obtained from the seeds of Euonymua europaus (Schweizer, J. pr. Ghem. liii. 437).
Acetic acid was also obsenred by Cheyreul among the product of uie saponification of

&tB.

Jeetoeilorkydrin, C»H»C10» = C«H«0« + C»HK)« 4 HCl - 2HK), is obtained by
pasaiflg hydrochloric add gas to saturation into a mixture of acetic add and glycerin
iieated to 100°, and satnnting the li<|uid with carbonate of sodium, after leaying it
at rest for seyeral days. This process yields the compound mixed with dichlorhydrin.
It is also obtained, together with the following compound, by the action of cmoride
of acetyl on ^ycerin. It is a neutral oil, smelling like acetate of ethyl and yolatilising
at about 250i°.

jieetadufAlor]^drin,(?BKJlH)* « 0"IPO« + C»H*0« + 2HC1 - 3H*0, is obtained by
adding chloride of acetyl to glycerin externally cooled, as long as any action takes
place, distilling the product, and purifying the distillate obtained between 180° and
160P, l^ agitation with water and then with an alkali, drying with chloride of cal-
dum and ouicklime, and fractional rectification. It is a transparent neutral oil
luring a reneshing ethereal odour, sparingly soluble in water and distilling at 205°
without decomposition. (Bert helot and De Luca.)

Diaeetochlorhpdrin, C'fl"C10* = C«H»0» + 2C»H*0* + HCl - 3H»0, is obtained
by the action of chloride of acetyl on a mixture of eqnal yolumes of glycerin and

ACETINS — ACETONE.

gladftl acetic acid. It is a neutral liquid which Tolatilises at 245^. (Berthelot and
DeLuca.)

Similar compounds are produced by the action of bromide of acetyl on glycerin.
By treating glycerin with a mixture of chloride and bromide of acetyl in equal numbers
of atoms, aceiochlorbromhydrin, C»H«ClBrO* - C»H«0« + C»H*0* + HCl + HBr -
3 H'O, is obtained as a neutral colourless liquid, smeUin^ like acetate of ethyl and
bromide of ethylene, boiling at 208°, and distilling without decomposition. It is
somewhat coloured by exposure to light. (Berthelot and De Luca.)
The formulae of all these compounds may be deriTod ^m that of a triple molecule
HHO
of water HHO. By replacing 8 at hydrogen in this formula by the triatomic
HHO

H 0

radide, glyceryl C*H', we obtain glycerin H(CH')0. Bepkdng 1, 2 or 3 at H in

H O

this formula by acetyl (CH'O » Ac), we obtain monoacetin, &c ; and, lasdy, the re-
placement of one or two molecules of jperoxide of hydrogen (HO), by chlorine in the
rormulae of monoacetin and diacetin gives the acetooilorhydiins. Thus :

Monacetin.

Aeetoehlorhydrin

Acetodichlorhydrin

H O

Ac(0»H»y"0
H O

H O

Ac(C»H7"0
CI

Ac(C5«H»)'"0

Br
Acetochlorbromhydrin . Ac(C«H»)'"0

Diacetochlozhydrin .

Triacetin .

Ac O

. Ac^C"H>y"0

(CPm"

. Ac\CTH7"0«.

AOBTXra. A compound formed from acetic acid and mannite in the same manner
as acetin from acetic asid and glycerin. (Berthelot, Compt rend, xxxviii. 668.)

AOBTOmrBB- A hydrometer graduated for determining the strength of com-
mercial acetic acid according to its density. (See Acbtic Accd.)

ACarOVa. C*H*0»C*H'O.CH* [or C*H^O^. PyroacOie spirit, Eanggtut,
BretiMBuiggeist (Gm. ix. 1 ; xiiL 462 ; G er h. L 700 ; iii. 943 ; ir. 906).— This compound
has long been known as a product of the destructiTe distillation of acetates (p. 28). It is
also produced by ^assins the yapour of acetic add through a red-hot tube ; by heating
gum, sugar, tartaric acid, citric add and other vegetable substances in contact with
lime ; and by heating dtric acid with permajganate of potassium, or with a mixture of
binoxide of manganese and dilute sulphuric add. (r^an de St Gilles, Compt
rend, xlvii 555.)

C«HK)' + 0 - C^H) + SCO* + HK).

Citric add.

It is prepared : 1. By distilling acetate of barium or acetate of caldum at a mode-
rate heat, the metal then remaining in the form of carbonate :

2C»H»BaO« « C«H«0 + bO«Ba*.

Acetate of barium when div and pure, yields a perfectly oolouriess neutral distillate,
in fact pure acetone. The caldum-salt requires a higher temperature to decompose it,
and the distillate is in consequence contaminated with an empyreumatic oil, called
dumtuitif C^'H^K). — 2. By distilling in an iron retort or (quicksilver bottle, a mixture
of 2 pts. of acetate of l^id and 1 pt of pounded quicklime, rectifying the product
sevenl times over chloride of caldum, and finally distilling over the water>bath.

Acetone is a limpid, very mobile liquid, of sp. gr. 0'792 at 18^ (Liebig), 0*814 at 0^
(H. Eopp). Itdoes not solidify at - IS^'* Boils at 56<' (Dumas), at 56-3<' (Kopp)
under a pressure of 760 mm. Evaporates quickly, produdng a considerable degree
of cold. Vapour-density 2*0025 (D umas). It has an agreeable odour, and a biting
taste like that of peppermint It is reiy inflammable, and bums with a white flame,
without smoke.

Acetone mixes in all proportions with water, alcohol, ether, and many compound
ethers. It does not dissolve potash or chloride of caldum. It dissolves many cam-
phors, fats and resins.

Acetone forms definite compounds with the alkaUns bisulphites. The potassium
salt, CHH) + SO* (KH), and the sodium-salt, C»H*0 + SO»(NaH) crystallise in
nacreous scales (Limpricht). The ammonium-salt^ CH'O + SO*(NH*H,) is de-
posited on mixing an alcoholic solution of bisulphite of ammonium with acetone, in

ACETONE. 27

ibling eholesterin, which quickly aggregate into a heavy dyetalline
powder. (Stideler.)

▲eetone was legarded by Kane aa an alcohol, CH^.H.O, containing tiie radicle CH^
which he called meaUyl, According to thia riew, howerer, the oxidation of acetone
ehonld yield prodncta oontainins C*, jnat as the oxidation of common alcohol, CH*0
yielda alddi jde and acetic add containing C; hut no such products are obtained.
A maie pfrobable view of the compoaition of acetone is that of Cnancel, who regards it
as aldehyde ooapLed with methylene, CH^O.CH', or, which comes to the same thing,
that of mihardt and WiBiamaon, who regard it as aldehyde in which the basic hy-

drogen is replaced by methyl; Q-gt \ • This Tiew is quite in accordance with the

deeompoaition of acetates into acetone and carbonates. For acetyl may be regarded as

a oomponnd of methyl with carbonic oxide; [C'H'O = GH". CO.] ; and it is easy

CH* CO )
to concerre that 2 atoms of acetate of barium -^ [0, may decompose in such

a manner that the CO of the one may unite with the two atoms of barium and
the two external atoms of oxygen, to form carbonate of barium, while the methyl
ranains in combination with the other atom of acetyl, forming acetone :

Acetate of barium. CailMnate Acetone,

of barium.

Tlie same view is strengthened by the &ct (discovered by Williamson) that when a
mixture of acetate and valerate of barium is heated, an acetone is formed containing
acetyl coupled with tetiyl (C«H*), or valyl (C*H'0) with methyl: thus

^^H».CO) f. ^ C*H».CO> rt CO > ^,^ CHK))
Ba P + Ba r "^ Ba^^ ^ C«H» {

DeeomponihfU of AceUm$, — 1. Acetone passed in the state of vapour through a red-
hot tube, d^oeits charcoal and is convert^ ioto a peculiar oil called dumasir^, which
generally passes over together with acetone in the distillation of acetates.

2. Acetone is decomposed by chlorine^ a portion of its hydrogen being replaced by
that element ; but it is not possible in this manner to replace the whole of the hydro-
gen by chlorine; even a mixture of chlorate of potassium and hydrochloric acid does
not inipesr to be capable of replacing more than two of the hydrogen atoms lij chlorine.
The higher ehlorinated acetones, may however be obtained by we action of chlorine,
or the mixture just mentioned, on otiier organic bodies. (See Chlo&acbtomes, p. 29.)

Chlofriru^ in presence of alkalis, converts acetone into chloroform :

C^H) + 12 Cl + H«0 « 2CHC1" + C0« + 6HCL

in presence of alkalis, acts in a idmilar manner, producing bromoform : but
iodine forms only a dark pitchy mass.

4. Ifydrookhnc aeid gaa is absorbed in large quantity by acetone, and according to
Kane, ^elds chloride of meeityl (or chloropropylene) CH^Cl. Hydriodic add gas
passed into acetone fonns, according to Kane, iomde oi mesityl, CH'I, which distils
over with the hydriodic acid ; iodide of pteleyl C*H'I (or rather tri-iodomesitylene,
OH'l*), which remains suspended in the residual liquid, in the form of yellow scales ;
and meaityl-hypophoephorous acid, CH'O.PHO, which separates in silky needle«i as
the liquid cools, f riedel (Compt. rend. xlv. 1013) stated that a solution of hydro-
chloric add gas in acetone yielded, when heated to 100°, acetic acid and chloride of
methyl (2C«H«0 + 4HC1 - C«H*0* + 4CB:«a), and similarly with hydriodic acid ;
hot he has since admitted that these results were obtained with impure acetone con-
tainii^wood-spirit.

6. With peniaehloride of phosphorus^ acetone ^elds chloropropylene, CH*C1, boiling
at about 30^ and methjfiehloracetol, a compound isomeric wiui chloride of propylene,
CH*C1'. This body treated with silver-salts, ammonia, etfaylate of sodium, or alco-
holic potash, is resolved into hydrochloric add and chloropropylene, identical with the
body obtained by the action of alcoholic potash on C'H'C1^ Hence it ajipears that
acetone is related to the propylene series. (Friedel, Ann. Ch. Fharm. cxii. 236.)

6. Strong niirie acid acts violently on acetone, giving off copious red fumes, and
lianning mesitie aldehyde, CH^O, and nitrite of pteWl, C'H'NO'. [or rather trinitro-
mesitir&ne, CH*(NO')^, together with oxalic and cyanuric acid (Kane). By
droppiiig acetone into nuning nitric add contained in a flask externally cooled, and
addOng water as soon aa the action ceases, a heavy oil is obtained, which explodes with
violeooe when heated, giving off red fumes. (Fit tig, Ann. Ch. Fharm. ex. 45.)

7. Acetone mixed with strong sulphuric acid becomes heated, and, according to the
quantity of add presentand the rise of temperature which takes place, forms either

28 ACETONK

oxide of meritjl, CE}*0, or meeitylene, CH", together with mesil^Lmlphiirie add,
SO^.CH'.H, and sulphnrouB add. (According to Kane, the composition of mesilylaul-
phniic add ia C*H*0,H0,8€^^ ana there iB formed at the same time another add

8. <$hidaljpAo0p£?r»0 add fonns with acetone a dark brown mass, partly oonsisting
of medtylphosphoric add. (S. a n e.)

9. A BOiution of phoaphorita in acetone turns add when kept for some weeks, and
more quickly when heated, even in perfectly air-tight vessels. According to Zeise, the
change consists in the formation of three peculiar adds, to which he gives the names,
phosphacetiCf acephotgenic and acephorio adds ; but their nature and compodtion have
not been dearly made out. Products of like nature are obtained with sulphur. Sulphide
of phosphorus forms with acetone a peculiar add, and an oil which hus a powerful
odour but no add reaction. (Zeis e.)

10. A solution of ammonia in acetone yidds, by spontaneous evaporation, a colour-
less syrupy reddue^ whidi gradually chanses into an alkaline liquid, consisting of
acetoninej CH^N*, an organic base, which bears to acetone the same relation that
amarine bears to bitter-aLmond oil :

SCmH) + 2 NH« - C»H»*N» + 8HK).

The non-basic compound first formed is perhaps isomeric with acetouine. (S t a d e 1 e r,
Ghem. Gaz. 1853, 241.^

11. By the action ox ammonia and sulphur on acetone, Zeise obtained a number of
products, which however do not present any definite characters. (Gm. iz. 11.)

12. By the simultaneous action of ammonia and h^drosulphurie aeidf acetone is
converted into thiaoetonine, a sulphuretted base consisting probably of G'H'NS*.
It crystallises in shining yellowish rhombohedrons, having an alkaline reaction,
sparingly soluble in water, but dissolving with facility in alcohol, ether, acetone, and
dilute adds. (Stadeler.)

13. When 1 volume of acetone is mixed with 1 voL disvlphids of carbon and 2 vols,
aqueous ammonia^ laminated crystals, resembling ice, form in the liquid after a few
days ; but these gradually disappear, and are suooeeded by laige yellow ciystals, which
are insoluble in water, sparingly soluble in ether, but dissolve, with decomposition, in
warm alcohol and in boiling hydrodiloric acid (Hlasiwetz, J. pr. Ghem. IL 365).
Hlasiwetz asdgns to these crystals the improbable formula CH^'N'S*. Stiidder, on
the other hand, regards them as the hydrosulphate of an organic base, cardo^Aiaoe^onin^,
CH^'N^', and represents their formation by the equation,

3CH-0 + 2NH" + CS« = C"H'«N«S» + 8H«0.

The formula C**H*"N*S'. H'S agrees pretty nearly with the analytical numbers ob-
tained by HladwetE. A cold alcoholic solution of the crystals forms with dichloride of
platinum a brownish yellow, amorphous predpitate consistinff of C**H*'N%'JE*tCl' J^,
and with mercuric chloride a white precipitate, whidi, according to Stadder, is merdy
Hg'Gl'S mixed with a small quantity of hydrochlorate of carbothiacetonine.

14. Acetone heated with a mixture of hydrocyanio and hydrochloric aeid, is con-
verted into acetonie acid, C«H"0* (Stadeler):

C«H«0 + CNH + 2H«0 - OEP0« + NH".

15. Acetone distilled with diehromaU of potassium and sulphuric acid, gives off
acetic and carbonic adds, but no formic add :

C»H«0 + 40 = C«H*0« + C0« + H*0.

16. Caustie alkalis, such as hydrate of potassium and quick lime, exert a dehydra-
ting action on acetone, several products b^ng formed, according to the proportion of
water abstracted. Lowig and Wddmann, by subjecting acetone to the action of
hydrate of potassium, obtained a dark brown mass, consisting chiefly of xylite-oil,
C"H»K), which boiled at 200°, together with a resin which they call xylite-resin,
Volckel, by leaving acetone for some time in contact with quidc lime, also obtained an
oil boil^ above 200^, which he regarded as xvlite-oiL But, according to Fit tig
(Ann. Ch. Pharm. ex. 32), the products obtained by the action of quick hme in dosed
vessels, are oxide of mesityl, CH^^O^ boiling at 131^, and a liquid isomeric or iden-
tical with phorone, (?BP*0. It must *lso be noticed that Schweizer and Weidm a n n
(J. pr. Chem. xxiii. 14) obtained xylite-oil, and likewise xylite-naphtha, C**H"0*, by
the action of potash and of strong sulphuric acid on a compound produced from crudo
wood-spirit, which those chemists called xylite, assigning to it the improbable formula
(y£P(A, but which was probably nothing but somewhat impure acetone. On the
whole it appears that the action of alkalis on acetone is similar to that of sulphuric
acid (p. 52), consisting in an abstraction of the dements of water. The products

ACETONE. 29

obtained by the action of theae dehydnting agents on acetone may be arranged as fol-
lows^ aceording to their boiling-points :

Botllng-potnt.

Xylite-naphtha . . CP«H«0« = 4C»H«0 - BPO . . IIO^ to 120o

Oxide of Hesityl . CH»0 - 2Cra«0 - H«0 . . „ 131<»

Hentylene . . 0»H" - 3C»H«0 - SBPO . . 1659 „ 160°

Phorane? . . C'H'H) - 8CTa«0 - 2H«0 . . 210<> „ 220°

XyUte-oil . C»*H"K) - 4 C«H«0 - 8BP0 . . above 200<>

Tapoor of acetone passed over heated hydrate of potassinm or potash-lime is resolved
into manh-gas ana carbonic anhydride :

CmH) + 2KE0 - CO*K* + 2CK*;

or if the heat is not yeiy strong the chief prodncts are acetic acid, formic acid and
fajdrogen:

C^«0 + 2KB0 + H«0-C*H»K0«+CHK0«+ 6H.

17. Sodium is violently attacked by anhydrous acetone, but without evolution of
bydrogen, and hydrate of sodium is separated in white flakes. The liquid gradually
•sBomes a pasty consistence, and the sodium becomes coated with oxide, so Uiat it no
longer acts perceptibly on the acetone. On distilling the mass, undecomposed acetone
passes over first, and afterwards a watery liquid collects in the receiver, covered with
a yelknrish oiL On pouring the distillate into a basin, so that the undecomposed
acetone may evaporate, the watery layer solidifies in a white ciyBtaUine mass, from
which the oal may be separated by pressure between paper. The crystids consist of
l^nie of pinaeane, CWH) + 7 HH), and the oily liquid is pkorone, C^E}*0. The
pinacone is produced by the abstraction of 1 at. oxygen from a doulale molecule of
acetone :

20^*0 + 2Na - Na«0 + C^>«0 ;

and the anhydrous pinacone thus formed appears to take water from another portion of
the acetone, oonTexting it into phorone :

3 CHH) - 2 H«0 - (m}*0.

By heatinff the crystals of hydrated pinacone in a narrow class tube, a viscid liquid
is obtained which absorbs water rapidly from the air, and is reconverted into the
dystalline hydrate. This liquid appears to be anhydrous pinacone ; but it is difficult
to ezpd sU the water (Stadeler, Ann. Ch. Pharm. cxi 277). Pittig (ibid. ex. 23)
assigns to the hydrated crystals, the formula CH'O •*• 3H*0, regarding them as the
hydrate of paraceiane, a compound isomeric with acetone, which he also states is ob-
tained in anli^drous crystals, by the action of ammonia on acetone. Fitti^s formulte
do not, however, agree with the results of analysis so well as Stadel^s (see PmAcoioi);
moreover it is yerv unlikely that sodium should act with violence on acetone, without
abstracting a portion of its oxygen. The action of ammonia on acetone, produces, ac-
cording to Stkdeler, not a crystalline compound, but a liquid organic base, acetonine
(p. 32).

18. Dry dieJdoride of plaHnum dissolves in acetone with evolution of heat, and
ibrms a brown solution, which, when evaporated, gives off hydrochloric acid, and leaves
a resinous mass, containing amoxig otner products, a yellow crystalline substance
called aeecklaride of plaHnum or eSoropUiHnite of mewtyl, G^>«0 J^*G1*. (?) This
compound may be obtained in larger quantity, bv triturating dichloride of platinum
with acetone to the consistence of a thick paste, leaving the mass in a close vessel till
it liquefies and ultimately forms crystals, washing these crvstals with acetone, and
parifjring them by orstallisation from boiling acetone. Acechloride of platinum thus
obtamec^ is yellow, inodorous, sparingly soluble in water, alcohol and ether, more
readily in aqueous chloride of potassium or sodium. Gold acetone dissolves ^ of it ;
boiling acetone a little more. The aqueous solution reddens litmus. The compound is
decomposed and dissolved by potash, forming a brown solution. When boiled with
water, it deposits a black substance called aceplatinow oxides probably 0^*0. The
same substance is deposited on boiling the mother-Hquor of adchloride of platinum.
The adchloride yields by distillation a residue of carbide of platinum, PtO. (Zeiss,
Ann. Ch. Pharm. zxxiiL 29 ; 6m. ix. 31.)

SvBSTXTunoir-PBODucTS OF AcBTONB. Ckloraeetones. — ^Each of theatoms ofhydro-
gen in acetone may be replaced by chlorine, giving rise to six chlorinated acetones. The
first oi these compounds is obtained by the action of nascent chlorine on acetone ;
the second by that of chlorine or the oxides of chlorine on acetone ; the third and
fourth by the action of chlorine on crude wood-spirit, probably containing acetone ;
the fifth and sixth can only be obtained by the action of chlorine or the oxides of
chlorine on other organic compounds.

30 ACETONE,

Monoehloraedone, CHK710, ia obtained by the action of a feeble dectnc euiTent
(from three Bunsen's cells) on a mixture of acetone and hydrochloric acid, the
chlorine set free at the positive pole from the hydrochloric acid, acting on the acetone
and taking the place of 1 at hydrogen. It is an oily, colourless liquid, which, when
separated from the watery solution and rectified, boils at 117^, has a sp. gr. of 1*14 at
14^, and vapour-density ^ 3*40. Its vapour acts strongly on the nose and eyes, pro-
ducing a copious flow of tears. (Biche, Compt rend. xuz. 176.)

j5icMoracetone, CH^CIH) (Kane's meniie chlorat)^ is produced bypassing dry chlorine
into anhydrous acetone, or better, according to StSdeler, by mixing acetone in a capa-
cious flask with twice its volume of strong hydrochloric acid diluted with an equal
bulk of water, and adding pulverized chlorate of potassium by small portions. It is
an oily Hquid of sp. gr. 1-381 (Kane); 1*236 at 90<^ (Fittig). Boils at 116*5<' rSta-
deler); at 121^*5 (Fittig). Vapour-density 3*2. Its vapour smells like chloro-
form at first, but, after a few seconds, attacks the nose and eyea with violence. The
liquid blisters the skin like cantharides, producing wounds wmch are difficult to heal
(Liebig, Kane, Fittig.) It is insoluble in water, but mixes in all proportions with
alcohol and ether.

THchloraoetone^ C'H'CIK), is obtained by the action of chlorine on wood-spirit.
When chlorine ^ is passed into ordinary (unpurified) wood-spirit, crystals are formed
consisting of C*M^*C1K)* {chhromentate of mtthylene), but if the action of the chlorine
be fiirther continued, the crystals disappear, and an oily liquid is formed, which is
terchlorinated acetone. It is heavier than water, has an extremely pungent odour,
and cannot be distilled without decomposition. (Bonis.)

JHraehloracetonef CHKIi^O, is obtained by dissolving the ciystals just mentioned
in wood-spirit and passing chlorine through the solution. It is an oily very volatile
and pungent liqui(£ whi^ blisters the skin. When exposed to moist air, it forms
crystals containing C'H'Gl^O + 4 H'O, which melt at 35^, and dissolve in water, alcohol
and ether, forming solutions which are not precipitated by nitrate of silver. The oystals
distilled with phosphoric anhydride yield the original anhydrous compound. This
and the preceding compound are doubtless formed from acetone contained in the wood-
spirit (Bouis, Ann. Gh. Thjs. [3] xxi 111.)

Pentackloraoeione, CHCIK), is obtained by the action of a mixture of chlorate of
potassium and hydrochloric acid on several organic compounds, viz. kinic, citric,
gallic, pyrogallic, catechucio and salicylic acids, sAao kinone, muscular fiesh, albumin,
indigo and tyrosin. The best mode of preparing it is to add a considerable quantity
of chlorate of potassium to a boiling solution of kinic acid, and then add strong hydro-
chloric acid in such portions that chlorine and chlorous acid may be continually
evolved. The distillate is concentrated by rectification over chloride of calcium. It
then, if tolerably pure, solidifies into a crystalline hvdrate when covered with water
at 4^ or 5^. If no solidification takes place, the proauct is contaminated with other
oils, and must be purified by figitating it with ice-cold water, and heating the de-
canted and darified liquid to 60^ ; the greater part of the oily impurities then separate
out. To purify it completely, it is converted into the ci^stalline hydrate as above men-
tioned, and the crystals are pressed between paper. The pure anhydrous compound
may be obtained by melting the crystals in a glass tube, whereupon they separate
into a watery and an oily liquid, the latter, which is undermost, being pure anhydrous
pentachloracetone. It is a colourless rather mobile oil, having a burning aromatic
taste, and an odour like that of chloral. Sp. gr. between 1*6 and 1*7. It remains
liquid at —20^ and boils at 190°. The hydrate, which crystallises in rhombic tables,
contains 4 atoms of water. Water dissolves ^ of its volume of anhvdrous penta-
chloracetone, and on the other hand, this compound takes up a certain quantity of
water without change of appearance ; but it then becomes turbid at the heat of the
hand, like hydrated conine. Pentachloracetone dissolves readily in alcohol and ether.
The alcoholic solution mixed with alcoholic potash deposits chloride of potassium
together with scaly crystals, probably consiBting of dicnloraceiaU of potassium, and
the solution is found to contain formic acid :

C*HCPO + H«0 = CHCa* + c«H»ca«o«

Chlorofonn. Dichloracetlc
add.

and: CHa» + 2 H*0 = 3 HCl + CHK)».

(Stadeler, Ann. Ch. Pharm. cxi. 277.)

Hexachloracetonet CCl'O (discovered by Plantamour, who assigned to it the formula
(CGl'K)*), is obtained bv the action of chlorine in sunshine on an aqueous solution of
citric acid. It is an oilv liquid of peculiar pungent odour, sp. gr. 1*75 at 10°, and
boiling between 200° and 201°. It makes transient grease spots upon paper, m-
dually reddens litmus paper, and forms with water, at temperatures not noove ^, a

ACETONES. 81

a^gtalliiM liydnte, CPCPO + KH), which melts at a temperatiEre abore 15^, with
Mpazatkn of an oil.

Bromacetone, CH'JfrO, is produced similarlj to monochloracetone» tiz. by the
action of a feeble electric cunent on a mixture of acetone and hydrobromie add. It is
eoloaxleSB when first prepared, but turns brown in a fbw minntes, and is decomposed by
difltiDatioii, the greater portion howoTer passing orar between 140^ and 146°. Its ya-
poor irritates the eyes so strongly that the spiUing of a few drops renders the air of
a room unendurable. (Bi ch e.)

lodeetbms aiqpears ako to be fanned in small quantity by the electrolysis of a mix-
tare of acetone and hydiiodic add. (Biche.)

Mtthylaeetone^ C*H*0 « (?K\CBF)0, — When crude commercial acetone,
or, better, the birown liquid which floats on the to^ of it, is dehydrated with diloride
of ealdum and then subjected to fractional distillation, pure acetone jpasses over below
60° and the distillate which is obtained between 60^ and 130°, yields, after about
thirty fractionations, three distinct compounds, viz. methylacetone, boiling between 75°
and 77°, ethylacetone, G*H>«0, between 90°, and 95° and dumasin, G*H^*0, between
120° and 126°. fFittig, Ann. Ch. Phaim. ex. 18.)

Methylacetone u a colourless liquid of sp. gr. 0*838 at 19^ 0. haTing the odour of
acetone, misdble in all proportions with water and aloohoL It combines with add sul-
phite of sodium, fbnning a crystalline compound, 2 C^H^aSO' + 8 HH), which is yeiy
aoinhlein water.

Etkvlaeetone, CVO ^ G^*(C^>)0.— Transparent, colourless liquid, smelling
fkintly like acetone, sparingly soluble in water, but misdble in all proportions with
akohal,spLgr.0<842atl9°. Boils between 90° and 95°. With acid sulphite of sodium
it fbcms tae compound 2G*H*NaS0' + 3 HK), which crystallises in colourless nacreous
lamins veiy soluble in water. (Fit ti g.)

ACBTOMBS or MWSOMWB* This tenn is applied to a class of compounds
which, like that just described, are composed of an add-radide united with an
alcohol-radicle. Nearly all the acetones at present known consist of the radide of
a&ttyacid combined with one of the corresponding alcohol-radides; their ceneral
fonnnla being OH*™+^. OH*"—* O. where m may be either greater or less ttian n.
When in»0, the acetone becomes an aldehyde, H.C"H*"'>0 - OH>>0; the
aeetonee may therefore be regarded as alddiydes in which 1 at hydrogen is re-
placed by an aloohol-radide.

Acetones are either amfle or compound. In the simple acetones, m « n— 1, so that
their goieralformula is 0-»H«»-". t>H«»->0. » C*"-»H^«0; thus, acetic acetone, for
for which » n2, is CH'.CH'O. The simple acetones are produced br heating the
barium or ealdum salts of the fktty adds, 2 atoms of the salt being decompomd in
soeh a manner that the acid radicle of one of them is resolved into the next lowest
aloohol-radicle and carbonyl (CO), so that a carbonate of ealdum or barium is formed
at the same time :

OH»"-»0)>^^C0.O-»H»-«)^ OH»^'0) ^ C0>^,
Ca P+ Ca J^"0-»H«->{ + Ca^^'

The formation of acetic acetone or methyl-acetyl (p. 26) by the decompodtion of
acetate of barium, is a particular example of this process. In like manner, propione
or eih^-propionyl, 0*H*.C»H*0, buiyrone or tntyl-butyryl, C'H'.C^H'O, valerone or
tetf^-wujfi, OH'.G^HK), are produced by tiie decompodtion of the propionates^ butyrates
Talentes^ &e.

These simple acetones were the onl^ ones known, till Williamson in 1851 (Ohem.
Soa Qn. J. ir. 238) showed that, by distilling a mixture of the barium or ealdum salts
of two different &tty adds, acetones may be obtained in which an add radide is as-
sociated with an alnmol-radide which is not the next bdow it in the series \m greater or
less than n~l] : these are the so-called compound or interme^te acetones. If the
adds whose salts are distilled together contain j> and ^ atoms of carbon, the decom-
position may be represented by the equation :

WH«^«0) rt ^ C0.Oi-»H*i-> > n OH»»- »0> CO > ^
Ca p+ Ca p'"Oi-»H*»->J"*' Ca«P'

or, since it is indifferent which of the add radicles we suppose to be decomposed, the

formulaoftheaoetone thus produced may also be ^_iW^_i[. Thus a mixture of

acetate andTalerate of ealdum yields by distillation either meiMfl-valyl, CH'.C'H'O, or
teir^-^Kriyi, C*H».C«H»0, dther. of these formulie bdng equal to CWa»0. Posdbly
two isomeric oompoimds having these formulae, may be produced together. If one of

CO TT)
the mixed salts is a formate, A > O, the alcohol-radicle separated from it is reduced

to an atom of hydrogen, and the acetone becomes an aldehyde. (See Axj>Bini>B8.)

32 ACETONES,

The compound acetones are also produced, together with the simple acetones and
other prodncts, when a calcium or barium salt of a fatty acid is distilled alone. ThuB
the distillation of butyrate of calcium yields, besides butyrone and a small quantity of
butyral, a considerable number of hydrocarbons (Bert helot, Compt. rend, xlfii. 236);
andomongtheee, methyl andethyl appear to occur, and give rise to the formation of ethyi-
huiyryl, C*H*.C*H'0, and methyliutyryl, CH».C*H'0. (Friedel, Compt. lend,
zlvii. 553.)

The following is a list of the acetones, or ketones, at present known, which are de-
rived from the fatty acids :

Methyl-acetyl (Acetone) .
Methyl-butyryi
Ethyl-propionyl (Fzopione)
l-butyryl .

Ethvl-butyiyl
Methyl-yalyl .
Trim-butjpyl (Butyrone) .
Metliyl-oenanthyl
Tetryl-valyl (Valerone)
Amyl-capronyl (Capronone)
Heptyl-capiyl (Caprylone)
Octyl-pelargonyl (t^elargonone)
Laurone ....
Myristone . . •
Falmitone or Maigarone .
Stearone ....

C«H«0 -CH» .C*H«0
C»H»0 - CH": .OffO
C»H»0 = C'H'.C'H-O
C«H»K)- C«H».C*H»0
C«H»0= 0 H».C»H»0
C'H"0 « C»H^C*H'0
C»H»«0 « 0 H».C'H»>0
C»H»0 « 0*H».0»H»0
C"H«0 « C«ff>.C«H"0
C»H«»0 » C'H» C«H"0
C»'H"0 « C»H".C"ff^O
C"H*«0 « C"H». C»*H»0
C»HMC - C»»H«'. C"H"0
C«»H«0 = C»H". C»*H»»0
C«»H«0 - C>'H» C»"H»0

Some of the compounds in this table are isomeric, e, g, propione and butyracetone.
Among the higher terms of the series, the number of such isomeric compounds is doubt-
less yery great, though but few of them haye yet been obtained.

These bodies, with the exception of acetic acetone, haye not been much studied.
Their reactions, so &r as they are known, resemble those of common acetone already
described. The lower terms of the series unite with the acid sulphites of the alkali-
metaJs, generally forming crystalline compounds. The best mode of purifying the
acetones is to shake them up with a strong aqueous solution of acid sulphite of potassium
or sodium, and distil the resulting solid compound with potash. The acetone then
passes oyer pure.

But little is known respecting acetones belonging to other series of adds. Two
haye been formed containing the radicle benzoyl, yiz. benzophenone^ or ^henyUhemoyl^
C^H^'O a C'H^.C^K), the acetone of benzoic acid, obtained by heating benzoate of
potassium ; and methyUbenzoyl, OHK) » CH'.O'H^O, obtained by distiYling together
equivalent quiintities of acetate and benzoate of calcium (Friedel). Benzophenone
treated with nitric acid yields nUroberusophenone^ C"H'(NO')'0.

The calcium-salt of camphoric add, which is dibasic, yields by dry distillation an oily
liquid called j^horone, which has the constitution of an acetone :

" r

Campborate of Phorone. Carbonate of

calcium. calcium.

and suberate of calcium, OH**0*Ca*, yields in like manner tuberone^ CH'^O, mixed
with other products. These are the only two acetones of dibasic acids yet disooyered.
(Gerhardt, Trait^ iy. 640.)

^ JLC8TOVZVX. G"H"N'. — ^Produced by the action of ammonia on acetone (p. 28),
either when a solution of ammonia in acetone is left to evaporate spontaneously to a
syrup, or when acetone saturated with ammonia is heated to 100^ in a sealed tube.
It is a colourless liquid, having a peculiar urinous odour, a burning taste and alkaline
reaction, easily soluble in water, alcohol, and ether. It unites with acids, forming salts.
The axalaU C»H"N«.C*H«0* + BPO crystallises feomahot saturated alcohoHc solution
in delicate colourless prisms, which are soluble in water, insoluble in ether, give off half
their water at 100^, tiie rest between 116° and 120°, and decompose at a higher tem-
perature. The ehloropltUinate, C*H**N*.HCl.PtCl*, forms lustrous, orange-coloured, four-
sided prisms with oblique terminal faces. It is soluble in water, also in boiling alcohol
containing hydrochloric add; insoluble in ether. (Stadeler, Ann. Ch. Pharm. cxL 308.)

iLOBTOmrxxiA. C'H'K. — A compound obtained by treating acetate of am-
monium or acetamide with phosphoric anhydride :

CH'O'.NH*- 2H*0 = (PH»N ; and C«H»NO - H*0 « C^«N.
Acetate of ammonium. Acetamide.

ACETON YL — ACETYL. 33

It » idantical wiih eyanide of methj], obtained by diHtillfng cyanide of potasftinm with
Bwtlytanlphate of potaagnm. (See Ctaiodb of Mbthti^T *

OdortotUmUriU^ CO'N, or cj;anideof trichlorometh^l, GCl'.GN, is obtamed.by dis-
tiSiiig tcichloraeetate of ammonium or trichloiaoetamide -with phosphoric anhydriddL
It IB a liquid boiling at 81^ ; of sp. gr. 1'4441. With boiling potash, it yields ammonia
and trichloracetate of potassium. 1% is Tiolentiy attacked by potassium. -

mil lIWi 111 CH^.— ^A hy^thetical radicle 'sopposed b^ Hlaaiweta to exist in the
TcUov ctyirtidtf Ibumed by the action of ammonia andbianlplude of carbon on acetone,
blaaweti asdgna to theee ciyatala the fbrmnla GKIP^'S*, and regards them as ml-
picemmaie of aoeiomd with mlpAocarbofutie of stdphaoetonyl ^ 2(C*H".2CNS) +
2C"H*%.(7H<N^. Stadeler^a new of the constitution of this compound (p. 62), is
Dodi mcTO probable.

JkCnosiRb. The name giTen by Gerhardt to the hypothetical radicle C*H" or
Cfi*, origmaUj called acetyl, and supposed by some chemists to exist in acetic acid and
its denritiTea. (See Acbttl and Vintl.)

AearaXTTbrn Kolbe's name for the radicle CH^O or C*JB*(^, usually called
acetyl, iHiich flee.

ACMTUMMoi^* Syn. of Acetyl-urea.

ACSnx. CTEPO or C*H^O\ Aoetoxyl, Othyl.—A radicle not yet isolated,
but BDppofled to exist in acetic add and its derivatiyes, the rational formula of acetic

acid being; on this hypothesis, ^ > 0, and that of acetic anhydride, nzH*0 ( ^*

The reason fop assuming the existence of this radicle in the acetic compounois is,
that the fiumula to which it leads, affords the simplest representation of the most im-
pcdant reaetions of acetic add and the other bodies of the series. Thus, when acetic

add -a- V O 18 treated with a metallic oxide or hydrate, the basic atom of hydro-

gm is lepiaoed by a metal, and an acetate of that metal -j^ > 0 is produced. On

treating the same compound with pentasulphide of phosphorus, F^S^ the external atom

of oiygen is replaoed by sulphur, and thiacetic add, n- [S is formed ; and by the

action of pentaehloride of phosphorus, the group HO is replaced by d, and chloride
of acetyl 0^'O.Gl is produced. (See Acbtio Acm, and Acids, p. 44.)

F<Nrmeriy, bowerer, acetic add, and the other members of the same group, were sup-
posed to be derired from the radide CH* or C*B*; and to this the name acetyl was
oc%iDaUy applied. Thus, anhydrous acetic acid was regarded as a trioxide of this
rM&le, Tiz. C*H*,0*, and the hydrated acid as a compound of this oxide with water,
riz. C*H*0*MO. &C. To applv the same name to two different radicles would of
eoazse create concision ; hence the terms acetoxyl proposed by Kolbe, and othyl (ab-
breriatioii of oxygen-ethyl) by IWilliamson, for the xadide C^'O. Most chemists,
howeyer, are of opmion, mat the radide supposed to exist in acetic acid and its deri-
TBtiyes, is most appropriatdy designatedby the term acetyl; and accordin^y, this term is
now generally applied to the group 0*11'0, while C^H", whidi more properly belongs
to anotlier series of compounds deriyed from alcohol, ether and ethylene, and haying
a leas intimate distant relation to acetic add, is caJled by a different name. (See
AcaiosiL and Vdttl.)

Acetyl, CETO is regarded by Kolbe as a compound or conjugate radicle,
eontaimng methyl and carbonyl, yiz. CH',CO ; and in like manner, propionyl, C'H'O,
is regarded as a compound of ethyl: CH^CO; bulyiyl, 0*H'O, as a compound
of trityl : CH^.CO, &c. each radide of a fatty add being supposed to contam the
next lowest aloohol-radide associated with carbonyL This yiew, which has been
adopted hy Gerhardt, in his " Traits de Chimie Oiganique" is based ujpon the fact
that certain methyl-compounds may be obtained from acetic add and its deriyatiyes,
and the oontruT ; similar transformations likewise taking place in the other terms
of the series, ll^us, a solution of acetate of potassium subjected to electrolysis, yidds
methyl and cazbonie anhydride :

CH".CO I Q ^cH»+ C0« + H

Cyanide of methyl boiled with aqueous potash giyes off ftmmonia and forms acetate
of potassium:

CmCKj. KHO + H*0 - ^^-^^JO + NH»;

Cyanide of

*■.— i

methyl Acetate of

potauium.

Vol. L D

ACETYL.

and acetate of ammoniiini (CH*.CO).NH^O, treated wiih.pho0p]ioric anhydride, giTea off
2H^0, and is reduced to cranide of methyl, CH'.CN. Hanh-gas, or hydride of methyl,
CH'.H, is prodnoed by the decomposition of acetates (p. 12) ; and caoodyl Aa(C'B-*)\
by the decomposition of acetic acid. The formation of acetone or methyl-aoetyl,
CH'.CH'O, m>m acetates, and the' correroonding transformations of propionatee,
yalerates, &c. (p. 26), is another example of the same kind of decomposition. Again
it has been shown by Wanklyn (Ghem. Soc. Q. J. zi. 103), that sodium-ethyl
subjected to the action of carbonic anhydride is oonyerted into propionate of sodium :

C«H».Na + C0« - ((?H».CO).Na.O ;

Sodium-
ethjl.

Propionate ofaodium.

and in like manner, acetate of sodium may be prepared from sodium-methyL
Lastly, many organic compounds, such as sugar, starch, alcohol, and acetone, which
are conxertible into acetic add by oxidation, may also, under the influence of chlorine,
or bromine, be conyerted into bodies belonging to the methyl-series, yiz. chloroform,
C(HC3.*).C1, and bromoform, C(HBr').Br. It must be obeyed, howeyer, that the
representation of acetic acid as a methyl-compound applies chiefly to a state of transi-
tion, just as the add is being produced from or conyerted into a body belonging to a
different series, and exhibiting different chemical relations ; so long as we are concerned
with the transformation of one acetyl-compound into another, such as that of acetic
add into chloride or bromide of acetyl, or of the chloride into acetic anhydride^ the

C*H'0)
formula ^ V 0 is suflident for the representation of all the changes which take

place.

The hydrogen in acetyl may be partly or whoUy replaced by other elements, yiz.
chlorine, bromine, &c. ; and hence anse the conjugate or deriyatiye radides, hromaceiyl,
ehhraeeijflt &&, which, like acetyl itself are hypouietical, not haying yet been isolated.
The following table exhibits a general yiew of the compounds of acetyl and of the
radides deriyed from it by substitution.

Bromide of Acetyl

Chloride

Iodide

Hydride

Hydrate

Oxide

Peroxide

Sulphydrate

Sulphide

Nitrides

Hydrate of Bromacetyl

Nitride . •

Hydrate of Dibromacetyl

Nitride . . • ,

Hydride of Tribromacelyl

Hydrate of Chloracetyl

Nitride •

Chloride of Trichloracetyl

Hydride

Hydrate .

Nitride .

Phosphide

H^dnte of lodacelyl

Nitride .

Hydrate of Di-iodacetyl

Nitride

Hydride of Tri-iodacetyl

Bromide of Acetyl, C«H«0

C*HH).Br

c«H»o.a

CH'O.I

C«H«O.H

C«H«O.H.O

(C«H»0)«.0

OTPO.O

CB*O.H.S

(C«HK))«.S
fC«H«O.H«.N
. (C«H«0)«.H.N
lc«H»O.C»H».H.N
&c. &c.

C»H«BrO.H.O

C«H«BrO.H».N

CHBr*O.H.O

C«HBr«O.H».N

C«Br»O.H

C«H«C10.H.O

C«H*aO.H«.N

CK)1«0.C1

C»C1«0.H

CH31«0.H0

C«a«O.H«.N.

C«C1«0.H«J>.

C«H*IO.H.O

C»H«IO.H.N

C«HPO.H.O

C«HI«O.H«.N.

CW).H.

Aldehyde
Acetic add
Acetic anhydride

Thiacetic add
Thiaoetic anhydride
Acetamide
Biacetamide
Ethyl-acetamide

Bromaeetic add

Bromacetamide

Dibromacetic add

Dibromacetamide

Bromal

Chloracetic add

Chloracetamide

Chloraldehyde

Chloral

Trichloracetic add

Trichloracetamide

Trichlorace1rn>hide

lodacetic acid

lodaoetamide

Di-iodacetic acid

Di-iodaoetamide

lodal

_ — . , .^ ^ „ ^ ^ x;.Br. — ^Prepared by slowly adding glacial acetic add to

pentabromide of phosphorus in a tubulated retort» distilluig, and rectifying :

C«H«O.H.O + PBr».Br" « C«H"O.Br + HBr + PBr«0.
It is a colourless liquid, boiling at 81°. When exposed to the air, it ftimes strongly
and immediatdy turns yellow. It colours the skin yellow, and is said to impart to it
the odour of phosphuretted hydrogen ; but this must arise from impurity. Water

ACETYL. 35

deeomposes it into aoetie and hydzobFomic acids. (Bitter, Ann. Ch. Phann. zcr.

Chloride of Acetyl. CH'O.GL — ^Prodnoed by the action of oxyehloride of phoe-
phom on acetate of potaaainm :

8{0«H»O.K.O) + FOOT - 8C«H«0C1 + PO*K» ;

or in tiie aame manner as the preceding componnd, by ^^igtiHi'Tig glaxnal acetic acid with
pentachlodde of phosphoroa :

c*h»o:h.o + pa«.a«. - c*h»o.ci + hci + pa«o.

Gerhard t, who discoTered this componnd (Ann. Ch. Phys. [3] zxzvii. 294), pre-
pand it by adding oxyehloride of phosphorus, drop by drop, to jEhsed acetate of
[jiitiiBinin A brisk action then takes place, and sufficient heat is produced to cause
die chloride of acetyl to distQ over into tne receiver, which must be well cooled. The
^irtpl«<» may be fieed from excess of oi^chloride of phoephoms hj re-distillation orer
leelate of potaasimn, then distDled by itself and the Hqnid which passes oyer at 66^
eoUeded apart The re-distillation oyer acetate of potassium is, howeyer, attended
with some loaa, in oonseqnenee of the formation of acetic anhydride.

C*BPO.Cl + C*HK).K.O - (C«HH))K) + KCL

For this reason. Bitter recommends the preparation of chloride of acetyl by the action
of pentachloridie of phosphorus on glacial acetic acid, the product being thereby ob-
tained in Iwger quantity and more essily purified.

Chloride c? acetyl is a colouriess, yery mobile, strongly refiracting liquid, of speciflo
cnrity 1-125 at 11<=>, 11305 at (P, and 1-1072 at ie9 (Kopp). BoOs at 66^. Vaponr-
deosity, 2*87 (G-er h ar d t) : by calcnlation (2 yoL) e 2'718. It fumes Bl^tly in the air,
and has a pungent odour like that of acetic and hydrochloric acid. The yapour at-
tacks the eyes and respiratoiy organs yeiy stron^y.

Chloride of acetyl is decomposed with explosiye yiolence by water, yielding acetic
and hydrochloric acids :

C«HH)a + H«0 = C»H*0« + HCL

AmmrtnU acts strongly upon it, forming acetamide :

C»H»0.C1 + H*N « CH'O.H'.N + HCL

Shnihriy with phenylamine, it forms phenylacetamide C^H*O.CfH'.H.N. Distilled
with acetate of potassium, it yields acetic azmydride :

C«HK).KO + C«H»0.a - (C«H"0)»0 + KCi ;

•ad with hesnate of potassium it forms benzoate of acetyl or acetate of benzoyl :

C'HK).K.O + C«HH).a - CH«O.C^«0.0 + KCl ;

ud similariy with the salts of other adds. With thiacetate of lead, it forms chloride
of lead, and probably also thiacetic anhydride :

0*H»OJTt).S + Cm*0,Cl - (C«H»0)«S + PbCL

When it is heated with zinc in a sealed tube, the metal is strongly attacked ; and a
black tany subtance is formed, from which water dissolyes chloride of zinc, and sepa-
ratei a hqoid haring an ethereal odour.

Hydride of Acetyl, See Aldshtds.

Iodide of Acetyl. C*H*O.I. — Obtained by the action of iodide of phosphorus on
aoetie anhydride (Guthrie, PhiL Mag. [4] xiy. 183), or on acetate of potassium;
(Cab oar I, Compt. rend. zliy. 1253). After being shaken vp with mercury and re-
diftilled, it forms a transparent colourless liquid, of sp. fi;r. 1*98 at 17°. It boils at
108° (Guthrie) ; between 104<> and 105° (Cahours). It fumes strongly in the air,
haa a reiy pungent odour, and an intensely sour caustic taste.

^ Iodide of acetyl is partially decomposed by distillation. Water decomposes it with
▼iolenoe^ finroung hymodic and acetic adds. It acts strongly upon alcohol, forming
Ketate of ethyL It is decomposed by zinc and by sodium at ordinaiy temperatures,
tin by mercury in direct sunshine, iodide of mercury being formed, and little or no
pomanent gas being giyen off.

Peroxide of Acetyl. C*H*0.0. — Biscoyered by Brodie in 1858 (Proceedings of
the Boyal Society, iz. 861.) It is obtained by mixing acetic anhydride and peroxide of
lanun, in equiyalent proportions, in anhydrous ether. The mixture must be effected
Toy graduaUy, as it is attended with great eyolution of heat. The products are
acttate of banum and peroxide of acetyl, the latter remaining dissolyed in the ether :

(C*H»0)«.0 + BaO = C«H»O.Ba.O + C»H«0.0.

D 2

36 ACETTLOUS ACID— ACHMITE.

The ethereal solution, after filtration from the acetate of barium, is carefully diBtHled
at a low temperature, and the remaining liqnid is washed three or four times with
water till the wash-water ceases to be acid. The residue is peroxide of acetyL

It is a -viscid liquid, extremely pungent to the taste, the sniallest portion placed upon
the tongue boming like cayenne pepper. It is highly explosiye ; a single drop placed
upon a watch-glass and heated, (explodes with^ a loud report, shivering the guiss to
atoms. It is a powerful oxidising agent, immediately decolorising sulphate of indigo,
conyertine protoxide of manganese into peroxide, and yellow prussiate of potash into
red prossiate. Barytarwater poured u^n it^ is instantly oonyierted into peroxide of
barium, with formation of acetate of banum. ^

Aeetyl'Urea. (See Ubbas (Compound) and Gabbamidb.)

ACaTT&OUB ACZB. AXASSYBIC ACSB. Lampio add, Etherio add.
An add supposed to be produced by the slow combustion of ether or of alcohol,
and under certain circumstances by the oxidation of aldehyde. When ether ia
repeatedly distilled, or allowed to fall in successive drops on a solid body heated to
about 1299, 80 that its vapour may come in contact with the air at a high temperature,
a disagreeable pungent odour is produced, supposed to be that of aldehydic acid.. 'The
compound possessing this odour is formed in larger ^quantity, when a spiral of fine
platmum wire, previously heated to redness, is suspended over a basin jDontaining
ether, and the whole covered with a bell-jar. The wire then continues to glow, 'the
ether underaoing a slow combustion without flame, and an acid liquid is formed,
which mns £>wn the sides of the bell-jar, and may be collected in a vessel placed
below. This liquid is colourless, has a very sour taste, and gives off a pungent vapour
which excites tears, and causes great oppression when inhaled. The same compound
is obtained, according to liebig, by heating oxide of silver with aqueous aldehyde ;
part of the silver is then reduced, while the other portion remains m solution in the
form of aoetylite of silver, and by decomposing this sUver^salt with sulphuretted
hydrogen, the acid may be obtained in the fi^e state. It is, however, very liable to
decompose, as aJso are its salts. When the silver-salt is boiled with baryta-water,
silver is reduced and acetate of barium remains in solution.

2C*H»AgO + 2BaH0 - C«H»BaO + C»H*BaO* + 2Ag + H»0

,, ^ y , -^ > , — -^ ^- , -^

Aldehydateof Hydrate of Aldehjrdate Acetate of
•ilrer. bariuin. of banum. barium.

Gerhardt (Traits L) is of opinion that the so-called aldehydic or aoetylous acid is
merely a mixture of aldehyde and acetic acid, the aldehydate or acetylite of silver being
in fact merely aldehyde in which 1 atom hydrogen is replaced by silver.

AOBZULBA XZULBVO&ZOX (3/tZ^/<>t/.)— The ash of this pknt has been
analjjTSed by Way and Ogston. 100 parts of the diy herb left 13*45 per cent, ashes con-
taining in 100 parts 80*37 parts of potash, 13*40 lime, 8*01 magnesia, 0*21 sesquioxide of
iron, 2*44 sulphuric anhydride, 9*92 silica, 9*36 carbonic anhydride, 7*13 phosphoric
anhydride, 20*49 chloride of calcium, and 3*63 chloride of sodium.

AOBBUUIXC ACZD. An add said to exist in millefoil (Achillea MiUrfoUum).
It crystallises in colourless prisms, soluble in 2 parts of water at 12^ *5. With the
alkahea it forms salts which are easily soluble in water, but sparingly in alcohol The
solutions are precipitated by neutral acetate of lead, whereas the free acid is precipi-
tated by the basic acetate only. The potassium, sodium, and oilcium salts are otb-
tallisable : the ammonium and magnesium salts diy up to amorphous masses. The
quinine salt is said to be obtained in fine crystals grouped in stars, when its aqueous
solution is mixed with alcohol, then boiled and left to cool slowly (Zanon, Ann. Ch.
Pharm. Iviii. 31). Neither the acid nor its salts have been analysed. L. Gmelin,
(Handbook, x. 207) su^^ested that this acid might be impure malic acid. According
to Hlasiwetz (J. pr. (Shem. Ixii. 429) it is aconitic acid.

AOBZXiXJUDi. A bitter substance of unknown composition, extracted by Zanon
from millefoil. It forms a hard, yellowish brown extract, having a peculiar odour and
bitter taste, easily soluble in water and in boiling alcohol, sparingly in cold alcohol
and insoluble in ether; but on treating it with a few drops of any acid, it becomes
easily soluble in ether; it dissolves also in ammonia. It is said to be useful as a
remedy against fever.

(See DiOFTASB.)

A mineral first distinguished by Strom. It has a brown-black or
red-brown colour on the outside, blackish or dark greyish green on the fractured sur-
fiices; in thin fragments it is translucent, and exhibits a yellowish-brown colour.
Sp. gr. 3*43 to 3*53. Scratches glass. Melts to a black bead before the blowpipe.
It crystallises in oblique four-sided prisms with tnincated lateral edges andveiy
sharp four-sided terminal faces, the edges of which correspond with the lateral edgee

ACHROITE^ACIDIMETRY. 37

of the oblique prifim. It has four desyagea, two parallel to the rides of the oblique
pcjgm, and the other two leas obrionB parallel to the tnmcatioxui of the acute latcoral
edgesL Aecording to the analyses of Berzelios and Kammelsbei^, its composition is
2feaA0»+ FeO^. 2SiO' {Si = 21-5 . 0 - 8) or 2Na«0.3SiO» + 2(Fe^O»,3SiO«)
(Si » 28*5 . O » 16.^ It occurs, though rarely, embedded in granite at £ger, and in
fljemte, near Pongnna in Norway.

▲ name giyen to the colourless Tariety of tourmalin.
xa. A name giyen by Breithanpt to a doubtM mineral,
hitherto fbund only in decomposed orstals (trigonal dodecahedrons^ which occur in
association with TseuTian from Yilui (riluite) : tiiey are perhaps denved from helvin.

A1" Itm^— ' '^^ , ACZCH&ratSDaSv &c. (See OxTBBOiiiDBS, Oxtohloeidbs,

AOBGUEXTBrn {Jcieular Biamutht NeedU ors,) a natiye sulphide of bismuth, con-
taimnff also sulphides of copper and lead. The formula assigned to] it by Dana is
(3Ck# + Biff^ -¥ 2(3J%i9 -i- BiS^) showing it to be analogous to Boumonite, with
which it IB uomorphoua.

It oocnrs embedded in white quarts, and accompanying gold, at Bereso^ in Siberia.

^jiipA — ^iiii^ fj^Q determination of the quantity of real add in a sample of
faydrated add, is a problem of frequent occurrence, both for scientific and for technical
puiposes. As the specific gravity of a mixture of add and water always increases
with the proportion of* acid present, and as, moreorer, a certain specific gnudty
always corresponds to a certain strength, provided no foreign substances are present,
it fellows that if the specific gravity corresponding to each particolar percentage of
real add has once been accuratdy detemuned and tabulated, the strength of any
giTsn sample of aqueous add may always be determined by taking its speofic gravity
and refeiTingto the tables. (See SxTLPEirBic, Nitbio, Hydbochlobio Acid, &c.) This
method is in fiict much used, the density being generally taken with the specific gravity
bottle for sdentific puiposes, and with the hydrometer for commercial estimations.
This method, however, necessarily supposes that the add £b pure ; the presence of any
foreign sabetanoe, such as nitrate of sodium in nitric add, cream of tartar and ex-
tractive or colouring matter in vinegar, &c would altogether destroy the accuracy of
the result. Moreover, in some adds, tiie specific gravity varies so little for consider-
able di£%rence of strength, that a yery slight inaccuracy of observation entails a large
enor in the result. In acetic add. for example (p. 11), an increase of strength amount-
ii^ to 1 per cent, produces on the average, an increase of density not exceeding
D-0034. for these reasons it is essential, especially for technological purposes, to adopt
some ready and exact method of determining the strength of an acid, independently
of its specific eravity .

The strengu of an add may be estimated :

a. By FciumeMc ancdysia, tLat is by ascertaining the measured quantity of a standard
alkaline solution required to saturate a given volume of the add. (See Analysis, Volt;-

MB'IIUC)

5. By Weight mudyris, • This mode of estimation might be conducted in various
ways : fior instance, by conyertmg a eiyen quantity of the hydrated acid into a neutral
salt of potaarium, sodium, barium, kad, silver, &c. dther by saturation or precipita-
tion, weighing the salt thus formed, and calculating the quantity of add from its
known composition. This method is indeed constantly adopted in scientific chemistiy ;
bat is for the most part too tedious for technical purposes. A quicker method is to
decompose a known vreight of the add with an excess of add carbonate of sodium or
potasnum, and estimate hy weight the quantity of carbonic anhydride evolved. The
quantity of real add in the sample of hydrated add is then easily calculated ; for each
atom of a monobasic add, expels 1 atom of carbonic anhydride (CO* » 44,) and each
atom of a dibasic add expels two atoms of carbonic anhydride (2C0' » 88) : this
win be seen from the fbUowing equations :

For hydiodilQiic add :

CO«NaH + CIH « ClNa + C0« + H»0.
GO* : C!1H - 44 : 36-5

For aeetie add :

GO^aH + 0«H»0«.H » CJ«H«0*.Na + C0« + H«0
CO* : CJ«H«0«.H • 44 : 60
For sulphmie add :

2CQ*NaH + S()*H» = SO^a« + 2C0« + 2H»0
2C0« : S0^« - 88 : 98 - 44 : 49

Suppose^ for example, that 13*5 grm. of hydrated sulphuric add thus treated with

D 3

ACIDIMETRY.

Fig.l.

acid carbonate of flodinm, eliininate 1*4 grains of carbonic anbydride. The quantity

49
of real add (SO^H*) in the 12'5 grm. is then 1*4 x j7 « 1*47 gmu and the

quantity of real acid in 100 parte of the hjdrated acid wiH be given by the equation :

X - 1*47 X i52 - 1089.

lo'O

A oonyenient apparatuB for these determinations is a small liffht glass flask {fa, 1) of
aboutlOO cubic centimetres (3 or 4 oz.) capacity, having a lipped edge, and fitted wi^ a
cork perforated with two holes. Into one of these apertures is fitted a bent tube a, carry-
ing a diying tube 6, filled witli chloride of calcium, and into the other, a narrow tube c,
reaching nearly to the surfeuse of the liquid, and bent at an obtuse angle above the
cork. A convenient quantity of the acid whose strength is to be determined, having
been weighed out in the flask, a quantity of add carbonate of sodium or potassium
more than suffident to neutralise the add, ib placed in a small test-tube about an inch
long, and having its lip slightly turned over, so that it may be suspended by a thread.
This tube is then let down into the flask by the thread* but not low enough to oome
in contact with the add ; the thread is fixed in its place bv inserting the cork into the
neck of the fiask, and the whole apparatus is weighed. The orifice of the bent tube r,
is then dosed with a plug of cork or wax, the cork of the flask loosened sufBdently to

allow the short tube ^, containing the alkaline carbonate
to drop into the add, and the cork immediatdy tightened.
The carbonate is now decomposed by the add, and carbonic
anhydride escapes through the diying tube, the chloride of
calcium retaining any moisture that may be carried along
with it. When the dfervescence ceases, the flask must bo
warmed to ensure the complete removal of the carbonic
acid from the liquid, and after it has cooled, the plug must
be removed &om the bent tube tf, and air drawn through
the apparatus by applying the mouth to the extremity
of the chloride of cidcium tube, in order to remove all the
icarbonic anhydride remaining in the flask, and replace it
by air. The whole is then again weighed, and the loss of
weight gives the quantity of carbonic anhydride which has
escaped. At the completion of the experiment, a piece of
blue litmus paper must be thrown into the liquia in the
flask; if it remains blue, the determination may be con-
sidered «caet : but if it is reddened, there is still free add
in the flask, showing that the quantity of carbonate intro-
duced was not sufSdent to decompose it. In t£at case, a second small tube (K>ntaimng
alkaline carbonate must be introduced as before, the apparatus again weighed,
and the whole process repeated. The second loss of weight added to the flrst, gives
the total quantity of carbonic anhydride evolved.

Another form of apparatus for these estimations, devised by WOl and Fresenius, is
shown in^. 2. ▲ and b are two small flasks, having strong nedu turned over in a

lip. Each of them is dosed with a tight-fitting
cork pierced with two holes. Through the cork of a
there passes a straight tube a, readiing nearly to
the bottom of the fiask ; a tube c, bent twice at
right angles, passes through both corks, termi-
nating just below that of a, but reaching nearly
to the bottom of the fiask b ; a straight tube d
also passes through the cork of b, termmating just
below it. The tube a is dosed at the extremitv b
with a plug of wax. The add to be estimated is
weighed oat in the fiask A ; the other fiask b is filled
to about one-third with strong sulphuric add ; and
the whole apparatos Ib connected in the manner
shown in the figure, the proper quantity of add car-
bonate of sodium being introduced into ▲ in a
short test-tube, suspended by a thread in the manner
described with the former apparatus. The whole
apparatus is then weighed, tne cork a loosened, so
as to allow the tube containing the carbonate to fiill into the acid, and the cork im-
mediately secured. Carbonic anhydride is now evolved, and is obliged to pass through
the sulphuric add in b, whereby it is completely dried. As soon as gas ceases to
escape, the flask a is immersed in water at about 5(P or 60° C. till the fr^sh
evolution of gas thereby occasioned ceases. The wax-plug is then loosened, to

Fig. 2.

n »

ACIDS. 39

pKfoit the solpluiiie acid in b £rom being foicdd into ▲, in oonseqiienoe of diminiBlied
pnomre in liiat Tessd; the apparatus is remoTed finnn the hot water; and air is
nAed thromgh the tabe d as long as anj taste of carbonic acid is peroeiyed. Lastly,
the ^jpaiatoB, -when quite cold, is re-weighed, and the loss of weight giyes the qnantily
of carbonic azdijdride evolTed.

This appantus is mneh hesner and more bnlliy than that before described, and
docs not a^pttr to possess any adTontage orer it Mohr points oat, as a sonrce of
inaeeoracy in its use, that the large ani&oe of the two flasks, being heated during the
eipegiinent» is not likely, on cooling, to condense exactly the same quantity of moisture
as was attached to it before.

It is of the ntmost xmpoitanee that the add carbonate of sodinm or potassinsv used in
these determinations, be <^mte pure and free from neutral carbonate. Tne acid carbonates
grre a white precipitate with chloride of mercury, and the neutral carbonates a red-brown
precipitate ; bat ihia test will not indicia the admixture of a small quantilr of neu-
tral carbonate with the acid carbonate. A more certain test of purify is to weigh out two
equal portions of the add carbonate, ignite one in a platinum crudble, and determine the
quantity of carbonic anhydride giyen off from the other by the action of the add in the
spparatos represented in Jig. 2 (See Alkauxbtrt). The quantity of neutral carbonate
of Bodiom remaining after the ignition should be to that of the carbonic anhydride
erndred as 53 to 44 ; and that of the neutral carbonate of potassium to the carbonic an-
hydride as 69 : 44. ^

If the add carbonate is not j^rae enough to giye a white predpitate with ddoride of
mercoiT, it should be at once rejected. Oommensial add carbonate of sodium, which will
stand that test^ may be farther purified by triturating it to a uniform powder, coTering
it with an equal weight of cold distilled water, leaving it for 24 hours, then washing
it two or three times on a filter with a small quantity of odld water, leaving it to
drain, and drying it by exposure to the air without heating. Acid carbonate of potassium
may be pur&ed by recryBtaJlisation. (For further details on Addimetry, see Dio-
tionary of Jrts^ MamufaetureSf and Afmes, new edition, toL i. p. 23.)

JLOTMMm Salts of hydrogen. The following properties are common to the most

important adds, —

1. Solubility in water.

2. A sour taste. (In those adds which possess the most strongly marked characters,

this property can be perodyed only after dilution wim a large quantity of
water.)

8. The power of reddening most organic blue and yiolet colouring matters (for ex-
ample, litmus), and of restoring the original colour of substances which haye
beeti altered by alkalis.

4. The power of decomposing most carbonates, causing efferyescence.

6. The power of destroying; more or less completely, Sie characteristic properties of
alkalis, at the same time losing their own distinguishing characters, and
forming alkaline salts.

The last is the only one of these properties which can be considered essential to
adds ; indeed, comparatiyely few acids possess them alL Moreoyer, there are many
sabstanoes which possess, in a greater or less degree, all these properties, but which
are nerer included among adds; of these it will besuffident to mention itium (sulphate
of potasdum and aluminium). Alum is soluble in water ; its solution has a taste
which, though not purely sour, approaches much more nearly to sourness than that of
many adds (benzoic add, for example) ; its solution also reddens Htmus, causes brisk
efferyesoence with alkaline carbonates, and neutralises completely the alkalinity of
potash or soda, forming an alkaline sulphate.

In order to get a more exact idea of what it is which essentially constitutes aciditr,
it may be usenil to condder briefly the opinions which haye successiyely been held
upon the subject by the chemists of past times.

In ordinary language, aeid is equivalent to sour; and in both Greek and Latin, the
idea of *' sourness" was expressed by almost the same word as that used for "vinegar,"
the only add known to the andents (thus, Crr, i^6s, sour; i^cs, vinegar: Lat. acidua,
soar ; aeetum^ vinegar). It does not> however, appear that very great importance was
at any time attached to sourness as a characteristic of adds from a chemical point of
view. The number of known adds was flrst increased by the labours of the Arabian
chemists * ; and the solvent power which many of them exert on substances which
are insoluble in water, seems flrst to have caused them to be regarded as a special
dasB of substances. Thus, Geber (middle of the eighth century), who was acquainted

* AliBott an ttM historical itatemcDtt eoDUined in thli article, for which no reference (a glren, are
■ade on che mitboflty of Ko p p, ** Geschlchte der Chemte," 4 toU. 8to. Brtuuwick, 1848« 47.

n 4

40 ACIDS.

with nitric add imd with an impure kind of sulphuric add, speaks of these bodies
under the common name of aqua diasolutiva. The idea of conoBiYeneBBi cor at
least a kindred idea, whidi may perhaps be expressed with tolerable accuracy as that
of chemical activity^ seems to have been long connected by chemists with the idea of
addify. For example, Van Helmont (Hred 1677 to 1644^ attributed the active
properties of quick-lime to a peculiar acid, which he supposed limestone to obtain £rom
the fire during burning. Stahl ^lived 1660 to 1734), who supposed the earthii and
alkalis to have the same qualitatiye composition (see Art At.Vat.t), represented the
alkalis as containing, in larger proportion than the earths, an add prindple to which
they owed their sreater diemical actiyily ; and even as lately as 1764, a similar idea
to that of Van Hdmont was applied by M ey er to explain a lai^ number of phenomena.
This diemist endeayoured to explain the different properties of the caustic and car-
bonated alkalis and alkaline earths, by supposing the former to be combinations of the
latter with a substance which he called aoidum pingtte (fatty add), because, as he
thought, fat-like properties could be perodyed by the sense of touch in its combinations
with alkalis (caustic alkalis). The idea that coirosiyeness is the most important cha-
racteristic of adds, was also plainly uppermost in the mind of Lemery, when (1675)
he attributed the properties of ad<u to a sharp-pointed form of their smallest partides.

That the properties of adds are, in some important respects, opposed to those of
alkalis, was perodved at a comparatively early period. This opposition of properties
was in fact the basis of the medical theory of the latro-chemists (from the first quarter
of the 16th century to the middle of the 17th century). . According to them, the con-
stituents of the human body had, some of them an acid, the rest an alkaline nature ;
the undue preponderance, or want of addity or of alkalinity was the cause of disease,
the condition of perfect health being a particular relation between these two opposing
qualities. Otto Tachenius, a chemist of this school, gave, in 1668, as the essential
diaracter of an acid, its power of combining with alkalis to form salts ; and accord-
ingly he induded silica among adds. Boyle was well acquainted with the properties
which are now considered most distinctiye of adds. He characterised aads by the
solvent power which they exert on various substances with various degrees of ener^ ;
by their power of precipitating sulphur and other substances from solution in alkau ;
by their power of changing the blue colour of many plants to red, and the red of many
others to bright red, and of bringing back to their original colour tliose which have been
changed by alkali ; and lastly by their forming with alkalis so-called neutral salts, at
the same time losing the properties just mentioned. This enumeration of the dia-
tinctive qualities of acids difi&rs in no important respect from that given at the be-
ginning of this artide.

Various suppositions have been made, from time to time, in order to account for the
properties possessed in common by the most strongly marked adds. In order to un-
derstand these, it must be borne in mind that the distinction which most chemists are
now accustomed to make between adds and salts, dates only from the time of La-
voisier, that is, from the end of the last centuir; and that, till his time, adds, alkalis,
and the substance^ now by preference called salts, were all induded under the common
term ealfe. But since the adds then known were comparativdy few, and, as was
natural, were those of which the add properties are most evident, the apparent dif-
ference between acids and other salts was much greater then than it is now.

The first theory of the constitution of adds was propdsed by Becher in his "Phydca
Subterranea," published in 1669. Ho attributed the common properties of adds to
their containing a common principle of acidity {acidum primiffenium)f formed by the
union of primitive earth * and water, and supposed that the distinguishing characters
of each acid were due to the particular substance which it contained mixed with the
primitive acid.

The ideas of Lemery regarding adds have already been referred to.

He was followed by Stahl, who, in 1723, revived and extended Becher*s theoiy.
The following may be taken as a summary of Stahl*s views: — The essential pro-
perties of all saline substances are: to affect the sense of taste, or to have sapidity;
to be soluble in water ; and with regard to other chief properties, such as specific
gravity and fixity, to be intermediate between water and pure earth. In some salts
the saline properties, are very marked, in others they are less prominent, and in some
they are barely perceptible. Those substances which are most saline, acids and
alkalis, have a great tendency to combine with bodies which have not saline pro- *
perties, and to impart such properties to them. Hence we may condude that some
substances are in themselves essentially saline, while others exhibit saline properties
merdy because they contain a substance essentially saline as one of their constituents.

* Acoordtng to Becher there were three primitlTe earths, — the vttrffiabte, the combaitfble, and the
mrreurial, — which were the cause* respectively of ftisibilitr, of combustibility, and of Tolatillty ( thus
correipooding to what the alchemists understood by salt, sulphur, and mercury.

ACmS. 41

We Brest fcgafd as belonging to the fanner ckM those bodies which not only
{MMBesi nfine propertiee (taste, solnbility, &e,) bat which can impart these properties
to other bodies by combining with them, and which, when separated &om their
eombinatioDS, recover their original qualities. Hence, aJl acids and alkalis, fixed and
Tolatile, bqnid and solid, must be considered as essentiallj saline. But, comparing
these bodies among themselyes, we find that eren they possess saline properties in yeiy
ranooB degrees. It appears, therefore, that there is only aTery small number of actual
primitiTe salts, or rattier that there is only one such substance, which is a constituent
of an other saline bodies, and is the cause of their saline properties. It is obvious
tiiat this sabstanee must be souf^t amcmg bodies which most distinctly and most
inranably manifest saline properties, and which are, at the same time, most simple in
their eompoeition. Following this rule, we may at once exclude neutral salts, as being
lesolraUe into more simple saline substances ; again, alkalis are more subject to
alteratioa and to loss of their saline properties than acids ; tiiey must, therefore, bo
cxchided. Of adds, we may select mineral acids as the most energetic Lastly, of all
rameial adds, viiriolte (sulphuric) is the most active, has the greatest solvent powers,
adheres most forcibly to the matter dissolved, is the most deliquescent, See. &c. Ao-
earding^, adds must be considered as the basis of all other sahne bodies, and vitriolic
add as Uie basis of all adds. (Macquer^s Dictionnaire de Chimie [1st. £dit. pub-
lished anonymously, Paris, 1766l[Artides "Adds" and *<Sel; " Kopp, iiL 16 ; also
Ene^rdopMie, ou Dictionnaire raisonn^ des Sdences, des Arts, et des Metiers, * *
mis en ordre et public par MM. Diderot et D'Alembert, t. xLv. [NeufchAtel, 1766]
Artide " 8el et Sels." The chemical part of this work was bv Malouin).

Sodi were the ideas respecting ados and the cause of acidity, which, with unim-
pcncant variations, were held by almost all chemists until tiie rise of the antiphlogistic
system of chemistij. (See Goxbustion.) But before the downfedl of the older
system, chemists had begun to have more exact notions than formerly of what were
dementazy bodies* and to fed the necessity of conddering as elements all bodies which
they eould not decompose. Hence, although Stahl regarded sulphuric add as a
aeeoodary prindple, formed by the union of the primitive prindples of earth and
water, and the other acids as compounds of sulphuric add with various substances,
many of the last uph(dders of the phlogistic theory regarded most of the inorganic
adds as simple substances. For instanee, phosphoric and sulphuric adds were sup-
posed to be elements which, when combined with phlogiston, formed phosphorus and
ml|A«y reapectivdy. Sulphurous add was one of the few inorganic adds which were
lesnded as compounds ; it was supposed to be sulphuric add combined with less
pl^giston than was needed to convert it into sulphur ; or, what was the same thing,
to be solphur deprived of part of its phlogiston.

But all previous ideas about adds were gradually superseded by those of L a vo isi er.
Having found, ej^)erimentally, that carbonic, nitric, phosphoric, sulphurous and sul-
phuric adds, all contained the then newly-discovered substance — oxygen (discovered
Aj^gost 1st, 1774), Lavoider conduded that oxygen was a constituent of aJl acids, —
that it was the addifying principle. (Lavoisier, Traits ti^mentaire de Chimie
(1st edit. 1789), i. 69 etpasnm; Kopp, i 308 ; also iii. 17.)

He first proposed this theory of acids in 1778 ; and, although adds were known in
^udi no oxygen oould be detected, nearly all chemists continued for about thirty
years to consider the assumption, that aridity was in every case due to the presence of
oi^gen, as a necessary part of the antiphlogistic doctrine. Berthollet, indeed, as early
as 1789, pointed out that hydrosulphuric and pmssic adds contained no oxygen ; but
it was not till about 1810, aiter Davy's and Gi^-Lussac and Th^nard's researches on
mnristie and oxy-muziatie adds (hydrochloric add and chlorine) that chemists generally
began to admit the existence of adds free from oxy^n. The condudons drawn from
these experiments were confirmed by Gky-Lussac's discovery of hydriodic add in 1814,
and by his examination of pmssic add inr 1816. From this tune, most chemists re-
eognued two dasses of adds — tiiose containing oxygen (oxygen-adds), and those
containing no oxygen (hydrogen adds). Attempts, however, were still made to dis-
eorer a constituent common to all adds, to which their common properties oould be
ascribed. Thus, on the one hand, Berzelius continued till 1820 to assert the necessary
existence of oxygen in all adds ; while, on the other hand, some chemists maintained
that all adds contained hydrogen as an essential constituent.

The latter opinion was advocated by Davy. "Hia ideas about adds appear to have
been essentially the following-: — ^No one substance ought to be regarded as the addi-
fying prindple ; the chemical properties of adds, as well as of other bodies, depend
not oniy on the nature of their constituents, but also on their corpuscular arrangement.
The so-called hydrated adds are the only true acids, and have a constitution similar
to that of their salts. Hydrated chlonc acid is a ternary compound of chlorine
oiygen, and hydrogen, analogous to chlorate of potassium, which is a ternary compound

42 ACIDS.

of chlorine, oTvgefa, and potassium. The whole of the oxygen may be remoyed from the
add, and it will remain acid ; the whole of the oxygen may be remoyed from the neutral
salt, and it will remain neutraL We haye no proof that in either of these bodies
the oxygen is divided between the chlorine and the other oonstitaent, or that either of
them oontaiiis so-called anhydrous chloric acid. Similarly, there is no proof that sul-
phates or nitrates contain anhydrous Bulphnric or nitric acid. Hydrated snlphoric and
hydrated nitric acids are the lane acids, and ore temaiy compounds, like the sulphates
and nitrates. (Davy, Journal of Science and the Arts, i 286 — 288 ; also Gilbert's
Annalen, Hv. 377—381 ; Phil. Trans. 1815, 212, 213; 218, 219; also Kopp.)

In 1816 Dulong proposed the theory, since known as the binary or hydrogen-theoiy
of acids. He endeavoured to show that all acids were similar in constitution to hy-
drochloric acid ; that they were all compounds of hydrogen with a radicle which was
in some cases simple (as in hydrochloric and h^driodic acids), in other cases compound
(as in hydrocyamc, oxalic, sulphuric, and nitnc acids). His view of the constitution
of these acids may be ej^iressed by the following formula : —

Hydrochloric acid S(€T)

Hydriodic jEr(/)

Hydrocyanic B(CN)atH(Ov)

OxaUc H(C^O')

Sulphuric SlSO")

Nitric hInO^

Salts, according to tius theory, were represented as compounds of an add-iadide
with a metal instead of with hycbogen ; thus : —

Hydrochloric acid . , ff{Cl)
Chloride of potassium , K (C^

Nitric add , . . H (NO^
Nitrate of potassium . K {ifO^)

Dulong^s theory resembled Davy's in so &r as it restricted the term acid* to sub-
stances containing hydrogen (Irrdrated adds), and assigned an analo^us constitution
to adds and their sfdts, but differed from Davy's theory in representmg the atoms of
every add as arranged in a spedflc manner : namely, all the atoms except hydrogen
as grouped together to form a compound radide.

These views did not attract much attention till they were applied by Liebig, in
1837t to explain the constitution of several organic acids, and of the various modifi-
cations of pnosphoric add (Ann. Ch. Fharm. xxyi. 170 ; Ann. Ch. Phys. Ixviii 70.),
and although the^r are explained and discussed in a large proportion of the Manuals
of Chemistry published during the fifteen or twenty years fbUowing that date, they
have never been generally adopted. Until a comparativdy recent date, almost all
chemists continned to regard oxygen-adds as a dass of bodies essentially ctistinct from
hydrogen-acids and from metallic salts. Confining the name of oxygen-adds to the
substances now known as Anhtdbides, they regarded oxygen-salts as bodies formed
by the direct union of adds with metallic oxides, and recoenised no essential distinc-
tion between actual hydrated adds (adds in the sense of Davy and of Dulong) and
mere solutions of the anhydrides in water.

An important extension in the then existing views respecting adds resulted from
the discovery announced by Berzelius, in 1826 (BerzeL Jahresb. vi pp. l^etseqX
that certain metallic sulphides, such as those of arsenic and antimony, were cajpable
of xmiting with the alkaline sulphides so as to form well-defined salts perfectly
analogous to those formed by the combination of the corresponding metallic oxides
with the alkalis. From this time, the existence of three new classes of adds (and
corresponding saltn) was recognised, namely, acids in which the oxygen of ordinary
adds was replaced by sulphur, or by the anidogous ^ements, selenium and tellurium.

We owe the ideas of the nature of adds, now very generally entertained, chiefly
tothe advance of organic chemisty, which has brought t(^ light a veiy large number, not
only of new adds, but of new substances of all kinds, whose chemical relations cannot be
adequately expreissed upon the system formerly universally adopted, of regarding all

* KotwithsUndfng the more itrlct use, which wu made by both Davy and Dulong, of the word
add, Tery many chemist* ftlll uie It to express bodies belonging to two very different cla«sei : acids and
anhydrides. Thus the bodies HCl, HN(P. HSSO«, NSO», SO^ are all of them flrequenily called acids,
although the first three possess marked resemblances among themselves and equally marked differences
from the other two. Again, the bodies H*SO^ and SO' are often called by the same name, sulphuric
acid, although thev cannot be obtained in any case by the same process, and although, when caused to
act upon one and trie same substance, thev almost always give rise to products essentially unlike. This
confusion between acids and anhydrides dates firom the earliest knowledge of the latter class of bodies,
and was caused by the fact that the anhydrides which were first discoTCred immediately produce acids
when thev come in contact with water. Thus, Lavoisier, by burning phosphorus in oxygen, obtained phos.
phorlc anhydride, bat since the solution of 'this substance In water contained phosphoric acid, he suppouNl
the anhydride to be the acid, and regarded the real phosphoric acid as a combination of phosphoric acid
and water. Similarly, sulphuric acid was looked upon as containing ** drv sulphuric acid *' (sulphuric
anhydride) and water ; and ail other acids, even those of which the anhydrides were unknown, as nitric
and hydrochloric acids, were, in like manner, regarded as compounds of a hypothetical anhydride (oftea
called "real acid ") with water.

ACIDS. 43

eomptmnd bodies as Ibrmed by the union of two molecoles possessing o^^KMite electro-
diemieal chsracterB} or of two groups, which, in their turn, have a siimlar binary confiti-
tation. Among the new theories wnich were the earliest to be thus introduced into the
■denee, was the " Theory of Chemical Types," which represented chemical compounds
as combiDations of the elementary atoms held together by the attraction exerted by
each atom npon all the rest, and capable of exchanging one or sereral atoms of one
dement for an eqnal number of atoms of another, so as to produce new substances,
built up after the same plan or type as the original compounds, though one or more
of tiieir atoms was of a different nature. According to this yiew, adds and metallic
salts were regarded as bodies of the same class : each add and its corresponding
sahs were regarded as compounds formed upon the same type, and differing only
&om the fact of the add containing hydrogen in the place of the metal contained
in the saltsi It wiU be seen that this manner of representing the mutual relation of
adds and salts differed but little from that of Davy.

Another result of the progress of oiganic chemistzy which helped to modify the
older notions on these subjects, was the acquisition of more consistent ideas than had
prenoosly existed of the relatlTe weights of different substances which are chemically
eomparaCle with each other. Thus it was discoyered that an atom of water con-
tained twice as much hydrogen as an atom of hydrochloric add, and therefore, that
the so-called monobasic adds, or adds containing the same quantity of hydro^n as
hydiocfaloric add, could not be compounds of wtJUir with anhydrous adds, as had been
hitherto supposed. The disooreiy by Gerhardt in 1852 (Ann. Ch. JPhys. xxxvii.
286) of the uihydrides corresponding to sereral monobasic acids, and the fatct of their
atomic weights bdng found to be double the atomic weights of the hypothetical
anhydrides of the older theoiY, confirmed the same condusion.

It is now dear that adds do not form a class apart, distinguished from other sub-
stances by something essentially different in their nature ; they are, on the contrary,
nothing more than a particular class of salts. The definition of adds as seUts of
y^drogen, first dearly enunciated by Gerhardt*, and repeated at the head of this
artide, is an accurate statement of the relations which exist between adds and other
ehemieal substances. This definition is, however, obviously insuf&dent, without
A previous answer to the question — what is a salt? For this we must refer to the
artide Salt. In that artide also the properties which adds possess in common with
other salts, and which characterise them as belonging to that class, will be most suit-
ably discussed. In the remainder of this artide we shall consider the distinguishing
properties of adds as such, and the mutual relations of the prindpal classes into
which adds may be divided.

The mode in which adds most frequentiy react with other substances is by double
decomiwdtion, in which they exchange their hydrogen for metals, or for radicles
possessing, to a certain extent, metallic functions. The following reactions are all of
this kind : namely, their reactions —

1° "With metals, —

Zn« + mSO* « H? + Zn«SO*.
3° With metallic oxides, sulphides, and salts generally, —

KHO + Ha - BPO + Kca
KHS + Hca = H«S + Kca

Pb«0 + 2HC1 « HK) + 2Pba
Fe«S + H'SO* « H«S + Fe«SO*
2NaCl + H^O* = 2HC1 + Na«0*
KNO» + H«SO* = HNO« + KHSO*

2P With the hydrates of alcohol-radicles,—

C»HMLO + HCa - HH) + CHH3L

Hydrate of Chloride of

ethyl. ethyl.

4^ With various metallic compounds, —

C«H»Zn + HCl = C«H».H + Zna

Zinc-ethyl. Hydrid«rof

ethyl.

KH«N + Ha = H"N + Ka:

Potauamine.

• Prfeis de Chimto organlque (Peril, 1814) 1. 70; Introdactlon k made de 1e Chimle par le Sytttoe
Unitalre (ParU, 1848). 103. On the similar characters of acids, or hydrogeo-salu, and of metallic salta
la general, and on the important differences between them and the anhydridet, oomp. Laurent, M^hode
de CUmta, pp. 49—56, or CaTendltb Society's translation, pp. 39 to 45.

44 Acros.

With some rabstanoes adds anito direcUj : namelj —

1^ With ammonia and its analogaes, —

NH« + Ha - NHH3I
PBP + HI « PH*I
2NC^' + ffiSO* » (NC^« H«SO«.

Aniline. Solphate of inUlneL

2^ With some hydrocarbons, —

C»H« + H«80«-.C*H-S0*

Ethylene. Sulphovlnle

add*

C»H« + Ha - 0»HTa

Propylene. Chloride of

trltyl.

Reactions such as the abore can be prodnced by all veQ eharacterised adds. The
minority of adds can also prodnoe other reactions of Tarions kinds, some of which are
chaxactezistic of indiyidnal adds, while others are common to a considerable number,
and therefore serve for their division into dasses. The rational formnlae by which
the various adds are commonly represented, indicate the nature of their lAo/li'tig
reactions, and hence to the class to which they bdong.

Ozygen-adds form by far the most numerous and important dass of adds. We
may tiuce acetic add as a special erample, and show how the double deoompodtions
which it is capable of undergoins, in common with the other adds of this dass, lead to
the choice of the rational formme by which ozygen-adds in general axe usually re-
presented.

1. When acetic add is converted into an acetate by acting upon it with an oxide,
metal, or any other substance, it loses hydrogen. This may^ represented by writing
one atom of hydrogen in its formula apart £i^m the rest : U^H^O* » G*H'0*,£L

2. By percblozide of phosphorus acetic acid is converted into diloride of acetyl, and
loses one atom of oxygen and one atom of hydrogen. To ei^ress this, we must
write the formula of acetic add thus ; CfH'O.HO.

3. By the action of pentasulphide of phosphorus, acetic add loses half its oxygen,
and becomes thiacetic add, 6(C«H*0*) + P«S» - 6(C«H*0S) + PW.

The rational formula derivable from this reaction is CH^O.O.

Combining these three expresdons, we come to divide the formula of acetic add

into three parts H, C*HK) and 0, and to write it ^^*^ 0, or H.C«H*0.0, or in some

similar way. This formula indicates beforehand, all the most frequent double de-
oompodtions of which acetic add is capable ; viz. the separation of one atom of
hydrogen, the other atoms remaining together (formation of acetates); the sepajration
of one atom of hydrogen and one atom of oxygen, leaving the group C*HK) (forma-
tion of chloride of acetyl, of aoetamide &c) ; tiie separation of one atom of oxygen,
leaving the remaining atoms combined (formation of thiacetic arid, &c)

The large number of adds which resemble acetic acid as to their leading double
decompodtions, recdve similar rational formulse ; that is to sav, rational formuhe con-
sisting of three parts : namely (1) one or more atoms of hydrogen, (2) one or more
atoms of oxygen or sulphur, (3) a radicle, nearly always compound and containing
oxygen, sulphur or a similar dement. Thus, writing the rational formula of acetic add

H ^» ""^^ write that of benzoic aoid -a 0, of pyruvic acid -a O, of

oxalic add m 0*, of phosphoric add ^, O*, of thiacetic add ^ S, of sulpho-

CS CN CI

carbonic add -g, S*, of sulphocyanic add ^ S, of hypochlorous add ^^ 0.

If in any of these formula we replace the radide b^ its equivalent quantity of hydro-
gen (see £!quivalents) and the sulphur (where it occurs) by its equivalent of

oxygen, we obtain the formula of one, two, or three, atoms of water -a 0> ^s O',

or ^, O*. Moreover, the decompositions of which water is susceptible are essentially

quite similar to those of acetic add. Thus, when converted into a hydrate by theac-
tion of a metal or of an oxide, water loses one atom of hydrc^n — K + H'O = H + HKO,
or CaH) + HK) « CaHO + HCaO ; oxychloride of phosphorus converts water into
hydrodiloric add, removing from it one atom of hydrogen and one atom of oxygen.

ACIDS. 45

3S*0 -I- POGH -> 3Ha + PO^H*; lastly, pentasulphide of phoephoros ooBTerts it
into h7dro8ii]^lrazic add, lemoviog i^m it one atom of oxygen : — 6BH> + P^* «
SEP8 -t- PK)*. It IB in this sense that water is taken as tiie i^pe, or standard of
eoaqniisoBl fbr acetic add and all other adds which undergo similar double deoom-
fffifilifffiiti

AnothfT dafls of adds are^ in the same way, referred to the type hydrodiloric add,
HCL These acids are sosceptible of only one kind of double decomposition : their
atoms axe separable into only two ^ups, hydrogen and a radide. Hydrobromic add
HBr, l^ydnooip add H7, hydrocyanic add HON, are of this daas.

These is still a third class of adds whidi may be referred to the type ammonia,
KH". Snfrinfmide, C^^'NO', cyanic add (earbimide), CONH, and snlphocyanic add
(snkhocaiinmide), CSNH, are adds of this kind. Under the influence of metallic
oxides, and hydrates th^ part with one atom of hydrogen, and take up in exchange
an atom of metal :

2(C*H»N0') + AgH) « 2((yH*AgN0') + H»0.

Swfrinhnldft. ' ▲rgento-succini-

mide.

CHNO + HKO = CKKO + IPO.

CfBBle Cyanate

add. of potaadunu

When boiled with dilute adds, they break up into two groups, a carbonised radicle
on the one hand (which combines wilL oxygen or with oxygen and hydrogen deriyed
from the water of the dilute add), and the gioup HN (whidi combines with two atoms
of hydrogen) on the other hand.

CHNO + H«0 = CO.O + HN.H».

Cjmic Carbonic AmmoDla

add. anhydride.

C*H*NO« + 2BP0 - C*H*0».H«0« + HN.H«

1 — ' * 1 "

Saocinlmlde. Succinic acid.

These reactions show that the rational formulse of these adds must consist of three
psits ; an atom of nitrogen, an atom of hydrogeo, and a radide composed of the

!Q4VT*f\2
H

that of cyanic add N.H.GO, or N j ^. The substance called by Oerhardt nitride of

beosoyl, soJ^hophenyl and hydrogen (C'H^'SO'K) is another add deriving from the
^pe ammonia. Its decompodtions have not yet been much studied, but its be-
haTiour with metallic oxides and its formation from ammonia by the succesdye action
of the chlorides ofsnlphophenyl and of benzoyl (C*H*S0^C1 and CHKX}!) require that
its lational formula should be composed of the four parts N, H, C*H*SO* and C'HK).
Knee the constituent atoms of this add are separable into four groups, it is evidently
«iaee|>itible of undoigoing even more numerous decompositions than dther the adds
deronng from the type HH), or those previously mentioned as deriving from the type
HH*, whoae atoms are separable into only three groups.

In regard to their ehemeal conttUuHon, we may thus divide adds into three prin-
cipal rlttfinriT, which haye the same mutual relations of formation and decomposition
IS hydiochloiic add*, water, and ammonia, and whidi may therefore be regarded as
doivin^ from tiiese bodies as types.

Bnt^ in the same sense as some of the adds whidi we have been Conddering, are
fanned from two, or from three atoms of the same type (from HK71*, H^O', H'O*, ^.),
there are certain others which are formed from two or more atoms of two (or perhaps
three) different types; £>r example, sulphuric add SO^H*, deriyes from the type

m[ 0*, tiius ^ m' [ 0*, while sulphamic add, SO'H'N, and chlorhydrosulphuric add,
SCraCI, derire lapectiyely from the double types ^^j and ^^|; thus ^^^*^ |

— solphamic add; ^ ^ ^ O ( ^ dibrhydrosulphuric add. Adds of this kind may

he called, finr tiie sake of distinction, intermediate adds. The so-called amic acids
(tee Aioc Aodb) afford the most numerous and best known illustrations of this

* Sineo tha icaeHons of the addi of the firit claii are alio poitesMd by those of the second and third
daises. It is plain that. If we hare regard to theie reactions only, all acids may be referred to the type
i^drodUorie add. To. this extent, but no ftirtber, the hydrogen-theory represents correctly the cou-
itttatioBoraU ~

46 ACIDS.

class. Like snlphamic add, they derire from, the type mQ [• They can gire rise to

two kinds of double decomposition ; that is, they can deoompoee either as hydrates
(derlyatiyes of water), or as amides (deriTatives of ammonia), according to the naton^
of the body with which they react. In like manner, chlorhydrosnlphnric acid and
analogons substances can decompose either as hydrates or as chlorides (deriTatiyes of
hydrochloric add).

Another way in which adds may be dassifled has reference to their btuieiiy: they
may be diyided into monobasic, dibasic, and tribanc* adds. Q-raham was the first
to call attention to the existence of polybasic adds in his paper on arsenic and phos-
phoric adds (FhiL Trans. 1833, 26S ; Phil. Mag. iii. 451, 469}. The distinctions
which he establiahed between monobasic and polybadc adds, had reference merely to
the composition of their salts. In 1837 Liebi^ (Ann. Ch. Pharm. zxri 138; Ann.
Gh. Phys. Izyiii 35) showed that tartaric, citnc, meoonic, and some other organic
adds were polybasic, but he pointed out no new general characters of polybasic acids,
nor any new way of fli««nngniHTn'ng them £rom monobasic acids. Gerhardt (Pr^ds de
Chimie Organiqne (1844), i. 71 — 84) was the first to connect the basidty of adds
with other &cts than the composition of their metallic salts, and he and Laurent (Ann.
Oh. Phys. [3] xviii. 266 ; M&hode de Chimie, 62—76, or Cayendish Society's Transla-
tion pp. 50 — 62) first placed the question on its present footing.

Mono-, di-, and tri-basic adds may be defined, in a few words, as containing respec-
tiydy, one, two, and three atoms of hydrogen replaceable by other metals, or by com-
pound groups of analogous function. Tms definition, taken by it»el^ is, howeyer,
obyioudy insuffident to dedde the basidty of any particular add, since, by properly
multiplying or diyiding its formula, we can represent it as possessing whateyer basidty
we please. Hence, before we can dedde what the basidty of an add is, we must
know its atomic weight, and conyersely, in order to fix the atomic weight of an acid
we require to know its basidty: in other words, the determination of its baddty and
the determinatibn of its atomic weight are the same thing. •

To dedde eithto of these points, we must take into consideration the general beha-
yiour of the add with other bodies, and the natnre of its deriyatiyes. The following
are the most important general differences shown by adds of different degrees of
basidty : —

a. Each monobaeic add a. Each dibasic acid can a. Each tribasic add can
can form but one ether, form two ethers; one of form three ethers; one of
This is neutral in its pro- them neutral, the other them neutral, the other two
perties. Twoydlnmes oiits add. (Thus, sulphuric add. (0.^. phosphoric add
yapour contain only one acid forms sulphate of ethyl forms phosphate of ethyl
Tolume of ethyl, or alcohol- and ethyl-sulphuric add.) and monethyl- and diethyl-
residue. Monobasic adds Two yolumes of the yapour phosphoric adds.) Two yo-
do not form add ethers. of the neutral ether con- lumes of the yapour of the

tain two yolumes of ethyl neutral ether contain three
or alcohol-residue. yolumes of alcohol-residue.

b. Monobasic addacasmot b. Dibasic adds can 6. TWdoMcaddscanform
form stable, weU-defined form, with each metallic three salts with the same
add salts, or salts with base, a neutral salt and an metallic base, two of them
two or more metallic bases, add salt, which last is add, and one neutraL

exactly intermediate in They can also form double,
composition betweeen the triple, and hybrid salts,
neutral salt and the free
add. They can also form
weU-defined double salts
containing two metallic
bases, as well as hybrid
salts containing two or
more metallic bases in in-
definite proportions.

0. Monobasic adds cannot c. Dibasic adds can form c,
form double or multiple double ethers, that is,
ethers, that is, ethers con- .ethers containing two kinds
t4uning two or more kinds of alcohol-residue. (Ex-
of alcohol-residue. ample, double oxalate of

ethyl and methyl.)

* It li 'probable that tetralMsic acids also exist, bat none bave yet been much inrestlgated : pyro*
phosphoric and silicic adds seem to be such.

ACIDS.

The aboTa distinctionfl apply to adds of all kinds, fiom whatever type they derire.
Hie loQowiiig apply only to adds which deriye from the type tDater (oxacids).

dL Each fMonoftosie oxacid d. Each dibastc oxacid
can Sum a chloride, in two can forma chloride, in two
Tohunes of the Tsponr of TolmneB of the Taponr of
wliidi is contained only one which are contained ttpo
ToltaaB of chlorine. £ach Tolmnes of chlorine. Di-
fodi chloride can take np basic oxacids can also form
in atom of oxygen and an chlorides which contain,
atom of hydrogen in ex- in two Tolnmes of vapour,
diaage fiv an atom of ddo- only one yolnme of chlo-
Bna to le-fbnn the normal rine, and are exactly inter-
aeid, — -hot there ia no com- mediate in composition
pound intermediate in com- between the chlorides last-
possdon between the chlo- mentioned and the normal
ride and the nosmal add. adds ; that is, they can

take up an atom of chlorine
in exchange for an atom of
oxygen and an atom of
hydrogen, to form chlorides
containing two yolnmes of
chlorine in two Tolnmes of
Taponr; or they can take
up an atom of oxygen and
an atom of hydrogen in
exchange for an atom of
chlorine, to re-form the
normal add. Thus, sul-
phuric add, SO^H^ forms
chloride of sulphuiyl or
chlorosulphuric aldehyde
S0K:;1*, and the intenne-
diate oom^xmd chlorhy-
drosulphunc add, SO'HCL

i. lionobaaio oxadds, by e. IHbasic oxadds, by

MBCtinff with MwtnAwi*, or reacting with ammonia, or

its deriTati-veB, form nea- its dariyatiyes, form neu-

tial amidge» in two yolnmes tral amides, in two yolumes

d. Each irihaeic oxadd
can form a chloride in two
yolumes of the yapour of
which are contained three
yolumee of chlorine.

e. Tribaeio oxadds, by
reacting with ammonia, or
its deriyatiyes, form neu-
tral amides, in two yolumes
of the yapour of which are

of the T^omr of ▼hich is of the yapour of which are

"^^^f*^ only one yolnme containea two yolumes of oontainecf three yolumes of

of nitrogen. There are no nitrogen. Intermediate in nitrogen. Intermediate in

coBipoBndB intermediate be- composition between these

tweoi theoe amides and the amiaes and the oorre-

CQETCspooding adds. spending adds are com-

pounds, generally add
(amic adds), in two yo-
lumes of the yapour of
whidi is containea but one
volume of nitrocen. For,
example, oxiuie add,
CO^H', forms neutral ox-
amide^ CH)«H*N*, and the
intermediate compound
Qxamic add C*0'H"N.

/. iionohaaie oxadds do f, Dihanc oxadds form

not form add compounds acid compounds (conjugate

(Khcalied oonjn^te adds) adds) m reacting with

by neacting wil^ hydro- hydrocarbons or other nou-

composition between each
of these amides and the cor-
responding add, there may
exist two add compounds,
one monobadc and contain-
ing in two yolumes of va-
pour two yolumes of nitro-
gen : the other dibasic and
containing in two volumes
of yapour only one volume
of nitrogen. iFor example,
dtric add, OHK)», forms
with phenylamine (aniline)
neutral dtrophenylamide,
C«HH)^Ph"N», (Ph - Cm» -
phenyl), and the interme-
diate monobasic dtrodiphe-
ny lamic add, C«H»0*Ph«N« ;
the dibade dtromonophe-
nylamic add, C«a»0«PhN,
has not yet been discovered.

/. Tribasic oxadds form
add compounds by reacting
with hydrocarbons or other
neutral substances. For

48 ACIDS.

caibona, or other neutral traL substances. For ex* example, phosphoric acid
substances. ample, sulphuric add re- reacts -with glycerin to form

acts with benzene to form phosphoglyceric acid.

sulphobenzidic (phenylsul-

phurous) acid, and with

glycerin to form snlpho-

glyceric acid.

(Compare Odline, Chem. Soc Qu. J. xi 127.) ^ ,

In addition to Siese, other properties of acids might be mentioned, which are con-
nected more or less intimately with their basicity; but, notwithstanding the number
of comparatively Tery well-defined characters which they severally possess, it is im-
possible to establish any absolute distinction between monobasic and dibasic, or between
dibasic and tribasic acids. There are many adds, which, in relation to a particular
set of reactions, have the properties of monobasic adds, but^ in relation to another set
of reactions, bdbave like cubasic adds; others, again, appear from one point of view to
be dibasic, while from another point of view they seem to be tribasic. This will ap-
pear more distinctly by considering what decree of generalit}^ belongs to each of the
differences we have pointed out between adcb of different basidties.

a. Number of ethers. Perhaps the only exception to this law is afforded by phospho-
rous add, whidi forms three ethers, one of them containing, in two volumes of vapour,
three volumes of alcohol-residue, although, as regards its metallic salts, it is only
dibasic.

6. Number of metaUio salts. Acetic and formic adds, which possess in a special
decree most of the characters of monobasic adds, form, each of them, two potassium-
and two sodium-salts.

0. MuUwle ethers. Ko exception to this law is known so far as regards mono- and
di-basic acids. Tribasic adds ought by analogy to form ethers oontaimng two or three
kinds of alcohol residue ; none such have yetbeen obtained, but there is no reason to
suppose that they might not easily be formed.

d. Number ofchloruUs. Some acids, which according to a, i, and o would be classed as
monobasic, form chlorides containing two volumes ofduorine, as well as intermediate chlor^
adds. For in8tance,Wur tz ' s ehlorwecPacityle oMorS, C«H«C1*0 (Ann.Ch. Phys. p] xlix.
60) reacts with one atom of water to form chloracetic add, C^*C10' ; and this, with
a second atom of water, forms glycollic add, C^H^O*. These three bodies are there-
fore related in the same way as chloride of sulphuirl, chlorhydrosulphuric add, and
sulphuric add. Again, lactic add, CSCO', a homofogue of glycollic add, is decom-
posed by pentachloride of phosphorus, giving chloride of lactyl, CH^CPO, whidi re-
acts with alcohol to form chloropropionate (chlorhydrolactate) of ethyl^ C^H*C10^
(Wurtz, Ann. Ch. Pharm. cvii. 192) ; that is to say, the ether of an add intermediat-e
between chloride of lactyl and lactic add. The intermediate add itself is produced
CH^CIO^ by the action of chloride of lactyl on water. (Ulrich, Chem. Soc. Qu. J.
xii. 23 ; Ann. Ch. Pharm. cix. 268.) So £Eir then as their chlorides are concerned,
glycollic and lactic adds resemble dibasic and not monobasic adds. (See also ob-
servations on e.)

In the case of tribasic adds, no intermediate chloradds are known, such as would
correspond to chlorhydrosulphuric add and other derivatives of dibasic acids. It is
probable that each tribasic add can form two such compounds, that phosphoric add
(PH'O*), for example, can form chlorhydrophosphoric acid (PH*C10',) dibasic?) and
dichlorhydrophosphoric acid* (PHCIK)', monobasic?)

«. Number and nature of amides. Some monobasic acids form amides containing, in
two volumes of vapour, two volumes of nitrogen. For instance, acetic acid forms
acediaminSj C'H*N^ between which and acetic add CH^O', acetamide C^H^NO is
exactly intermediate, (just as oxamic acid, C^^O', is intermediate between oxamide,
O^H^N^O^ and oxalic add, C*RK)*) ; acetamide, however, is neutral, not add, in its
properties.

Certain other adds, generally considered monobasic, form amides oontainiug one
atom of nitrogen, which possess some of the properties of acids. Thus glycolUc add,
C*H*0', forms glycoooU, C'HfN^O', a substance capable of acting as an acid, and pos-
sessing the same relation of composition to glycolhc add, that oxamic acid does to ox-
alic add, or acetamide to acetic acid. The so-called benzamic, toluamic, cuminamic.
&c adds, are substances of a similar constitution : they are to oxybenzoic, oxycuminic,
&c acids what glycoooll is to glycollic acid. In short, glycollic and similar adds,
though in the strict sense monobasio are diatomic; that is, they form but one salt

* Chlorhvdrocalpbarie acid if formed; when nilphorlc anhydride fi brought in contact with drj
hydrochloric acid (SO*-|-HCl a SHCIO'). Similarly, a liquid, which probably conUtiiB one or both uf
the compounds mentioned in the text, is farmed when photphoric anhydride u exposed to dry hydro-
chloric acid (r30»+8HClBFH>C103+PHClsO«~?)

ACIDS, 49

viA Meli metallic base— are monobasie sjb regards their metallic salts, — ^bnt resemble
dibasie adds ao fu as reeards their other deiiyatiYes (chlorides and amides).

/ FbrmaHon of comipUx adds. The difference in respect of acidity between oom-
poDnds fbnned by the reaction of monobasic and of polybasic acids on neutral sub-
stuMB, is a paiticalar case of a general role which was first announced by Gerhardt
rPi^ev de Chim. Organ. L (1844) 102 ; Gompt. rend. Trav. Chim. 1846, 161) in the
nDoving fonn ; ^ « ^ + & — 1, where B denotes the basicity of the body resulting from
the the reaction, h and V the basicities of the reacting substances (me basicities of
ilkilineorDeiitnl sabstanoes, and of mono-, di-, and tnbaaic acids beine estimated re-
speetiTel;^ as 0, 1, 2, and 3). Strecker (Ann. Ch. Fharm. IxviiL 47)8howedthat the
nle admitted of a somewhat more extended application in the form £ » 6 + V — o^,
i^ere wa denotes the nmnber of atoms of water which separate in the reaction. Pir ia
(Ann. €3l Pharm. xcri 381), observing that, when more than two substances reacted
upon eadi other, the number of atoms of water formed was usually one less than the
nvmber of reacting substances, eicpressed the role of basicity in the following form,
B^h -^V •\' If -¥ . .. . — (w— 1), (n being the number of reacting substances).
In all these ezpreesions, one substance only is regarded as the essential product of thd
reaedon, bat^ if we take into consideration the basicity of all the products (water,
faydiochloiic add, &c. as well as more complex substances) and r^iard water as s
monobasic * acid, wb amve at the following expression — Th» sum of the basicities of
tktfroduets of a reaeHon is equal to the sum of the iasiciiies of the reacting bodies.

Examples: —

HCl + KHO « KCl + H«0
1 4- 0 « 0 + I

TP80* + KHO « KHSO* + H«0
2 + 0 =. 1 +1

H«SO* + KHO ■». KHO « K«SO« + HK) + H»0
Bttidtiea 2 + 0 + 0 » 0 +1+1

Aeetataof
add. Atodbol. ethyl.

Cm*0» + C«H«0 = C*H»0» + HK)
1 .^ 0 t» 0 + 1

Aectamide.

C^«0» + NH» - C»H*NO + H*0
1 + 0 = 0 +1

Aoetochlor-
hjrdrobrom.
Gl7<cerin. bydrin.

C*H«0* + Ha + HBr + cSw = 0»H»OKaBr + H»0 + H«0 + H^
al+l+l+0« 0 +1 + 1+1

FlKMpluaildew

'P0N»H«' + H«0 + H«0 + H«0 =.H*PO* + NH« + NH« + NH»
Btsicifies 0 +1+1 + 1» 8+0+0+0

The application of the rule of basicity to substances which, like glycollic acid, are
Bonatomic in some relations but diatomic in others, or, like phenyUc alcohol (carbolic
add), are intermediate between neutral bodies and acids, often leads, as might be ex-
pected, to eontiadictoiy results. It must be looked upon, not as a law uniyersally true,
bat as a rale applicable to the minority of cases, and always dependent on our defini-
tions of acidify and basicity. (Gomp. Kekul^ Ann. Ch. Pharm. cri. 130.)

It hM been pointed out by B eke toff (Bullet de TAcad^mie de St. P^tersbourg; zii.
369) that this law, in- any of the forms yet given to it, gives contradictory insults
when applied to the three following reactions, which nevertheleBS are strictly com-
parable with each other.

* IT water be also cooddend at a momacfd btue, the acfditif of baaes (or the nnmber of atomi of acid
vfth whtcfa tbey reset, — a property correlatlTe with baskHjf,) !• usueDy conformable to' the following
into:. Tie jMM iff the admUu ^ the products qf a reaction iM equal to the turn of the oddities qf the
rvMoift. The reprcMotation of water at a monobatlc acid and at a monadd bate expreitet the i^t
tttt It tetily takea dp 1 atom of an electro-potltlTe, or of an electro-negatiTe radicle in exchange for an
a:om of bydmm. or. an electrt>.potitire amd an electro-negati«« radicle In exchange for the two atomt
efiifdraMD. The repreaentatlon of water at a dlbatie acid (or at a diacld bate) exprettet the posti-
bm^ ofiv^adna both atmnt of hydrogen by the tame radicle (formation of anhydridet). Thit re-
■lirMniii tbonfoot anfreqiwnt, certainly Uket place lett readily than the replacement of 1 atom of
IfdrogcD oDtyTor than the replacement of the two by radldet of dlflbreot electro-chemical qualitlet,
Bkber view, toverar, U evidently entirely relaiiv;.

You I. E

60 ACIDS.

Benxoie Bensoato

actd. Alcohol. of ethyl.

1. cmK>* + C«H«0 « C^»»0* + H^O
Basicities 1 -i- 0 » 0 4- 1

Aceto-
Beniolc Acetic bensoic

add. acid. anhydride.

2. C^«0« + C«H*0« - C»H"0« + H«0
Basicities 1+1 0+1

Methyl.
Methylio ethyl

Alcohol alcohol. ether.

8. C«H«0 + C«HH) = C»H»0 + HK)
Basicities 0+0 0+1

According to tiie conTcntions which have been made above, the sum of the basicities
of the products of the first reaction is equal to the sum of the basicities of the re-
agents, but in the second reaction it is less, and in the third it is ^;reater. The
obviously artificial character of the law of basicity, which is sufficientiy shown
by these instances, induced Beketoff to propose to compare the whole quantity of
replaceable hydrogen in the reagents witn that in the products, instead of merely
comparing their basicities, or the number of atoms of hy(bx>gen which are easily re-
placeable by basylous radicles. If the so-called t^ical formulss (see Fobxulx,
IIationaii) are employed in writing the above reactions, it at once becomes evident
that in each case the whole quantity of replaceable hydrogen is two atoms, both in the
products and in the reagents ; ana in all regular double decompositions, the whole
number of atoms of replaceable hydrogen remams similarly unaltered (For an aooonnt
of all that is important in Beketofifs paper, and for an extended criticism of the
law of basicity, see Kekul^ Lehrbuch d. organisch. Chemie, pp. 210 — 219.)

A general classification of adds according to their composition cannot yet be given.
There are but few elements which are known to form more than two or three distinct
acids ; and, although many remarkable relations can be pointed out among the acids
formed by different elements, these relations are more important as inucations of
analogies among the elements, than as serving for the classification of the acids them-
selves.* There is, however, one element — carbon — which, in combination with hy-
drogen and oxygen, forms a very large number of acids, the best known of whichy
generally exhibit, when compared together, certain gradations of chemical composition
and properties, in accordance with miich they can be arranged in a number of homo-
logous series, (See Homology.) The most important of these series are the fol-
lowing:—

a. Monobasic acids represented by the general formula C'H^O'.

Formic acid CH«0*, Capioic acid O^>«0«

(Enanthylic „ CH"0«,

CapiyUc „ C«H»«0»,

Pelaigonic „ C»H»»0«.

Rutic or capric „ C"H»0«,
&c

The adds of this series are found in various vegetable and animal products ; several
of them occur in combination with glycerin as the chief constituents of most natural
solid and liquid fats. The first four have been found in mineral waters (Scheerer,
Ann. Ch. Pharm. xcix. 267). Thev are produced artificially by a great variety of
processes, the most important of wnich are the following :

1°. The oxidation of the alcohols C»H^+«0

C«H«0 + 0» - C«H*0« + H»0.

Acetic „

C«H*0«,

Propionic „

C»H«0»,

Bu^rrio „

C*H»0«,

Valeric „

OH"0*,

•If

Ethyl- Acetic

alcohol. add.

2^. The decomposition of the so-called nitriles, or cyanides of aloohol-radides, of the
formula 0"H*»- *N, by alkaline hydrates.

C»H«N + 2HH) - C»H«0« + NH«.

-r

Acetonltrlle Propionic

or cyanide acid,

of ethyl.

• For an able exposition of nearly all that can yet be laid on this point, see Odllng, PhfL Maff. sviii.
8G8 : also a lecture on ** Adds and SalU," delivered by the same at the Royal Institution, 80th March.
1860, Chemical News, I. Sao.

ACIDS. 61

1^. Tlie o(niil)matioii of thepotasBimn- and sodinm- compounds of the alcohol-radicles
D'H^'*'' with carbonic anydride.

(?H»Na + C0« = C«BPNaO«.

«-

Sodinm- Propionate

ethjL of sodium.

4®. The oxidation, destrnctiTe distillation, fermentation, or putre&ctiTe decompo-
sition of complex oiganic compoonds.

When a fixed-alkalino, or alkaline-earthy salt of one of these acids is snbjected to
diy distiUation, a carbonate and an acetone are generally produced. These products
ire foimed by the decomposition of two atoms of the salt.

Hie drf distillation of a mixtoze of the fixed-alkaline, or alkaline-earthy, salts of
teo acids of this series giyes rise, in like manner, to a carbonate and to an acetone
intermediate in composition between the two acetones corresponding to the acids
enpkyed.

When one of th^ salts is a formate, a similar reaction takes place, but an aldehydo
is then produced instead of an acetone.

In some cases the diy distillation of salts of these acids produces (besides acetones)
aldehydes, or isomeric compounds (butyral, Taleral ) and hydrocarbons. (See Albb-

STUBS, ACSTOHBS.}

When distilled with excess of alkaline hydrate, they give hydrocarbons of the
fiinnnla OH"*'**' (hydrides of alcohol-radicles) and alkaline carbonate.

(?H»KO« + HKO - CK«0« + OH*.

Acet. potaa- Hydrida

dum. of methyl.

With pentachoride of phoshorus they produce chlorides of the formula OH^~'OG1 ;

^' c*H*o« + pa» « c«H»oca + pooi» + Hca

Aoetle acid Chloride

of acetyl.

Tbsff ilkaline salts distilled with azsenioos anhydride giye compounds of axsenio
with the aleohol-radides. (See Absenio.)

Subjected to electrolysis, they give carbonates, alcohol-radicles, hydrogen and hy-
dwcartons of the form OH*» and OH*»+».

Under the influence of chlorine (or bromine) they lose one or more atoms of hydro-
gen, and take up in exchange an equivalent quantity of chlorine, forming chloracids
'^lose general properties usually resemble closely those of the normal acids from which
they are formed.

(?HW + Cl« - C«H«C10« + Ha

' — , — ' * , — — '

Acetic acUL Cbloracetlc

acid.

w + Br« -= C*H?Br*0« + 2HBr.
> , '

Dlbroma
acetic acid.

„ + a* - C»HC1«0» + 3HCL

Trichlor-
acetic acid.

& Acids represented by the formula C'H^O*, di-atomic^ but usually monobasic.
Tke adds of Uiis series differ from those of series a by containing three, instead of
two, itomfl of o^gen.

CJarbonic acid CH«0«,

GlycolHc „ C«HK>»,

Lactic , C»H«0»,

Butylactic „ C*H»0«,

ValerQlactic„(Buttlerow). . . . C»H>«0«,

Lendc OWK>»,

These adds are formed

1®. By the reaction of the protochloro- or protobromo- deriTatiyes of the acids of
Kries a with hydrates.

0*H»C10» + HKO - C«H*0« + KCSL

Cbloraoetlc GlycoUle

add acid.

B 2

52 Acros.

2^. Br the ozidatioii of the diatomic alcohols, C>H*> * *0* (glycols).

C*H«0« + 0« - C«H*0» + HK).

Glycol. GlycolUe

•cid.

8®. By the ozidatioii of certain amides of animal origin (glycoool and faoi

eepecially bj nitrons acid.

C»H»NO« + NHO« - C«H*0« + N« + H*0.

^ , — -^ * — . — '

Glycoool. OlyeolHc

acid.

4^. By fermentation.

The acids of this series are decomposed by heat into anhydrides and ▼!
the case of carbonic acid, this decomposition tiJces place at the ordinazy tern

With pentachloride of phosphorus, they produce diatomic dilorides of th
OB[^-*OC1«; e.g.

C?WO* + 2KJP = C«H*0C1* + 2P0C1« + 2HCI

v« — r-^ ^ r— ^

Lactic add. Chloride of

lactyl.

Lactic acid heated ^th hydriodio add prodnces water, iodine and prop
(Iiautemann) :

C»H«0» + 2HI - C^«0« + H*0 + P

Lactic add. Pit^ionlc add.

This win probably be £rand to be a general method of oonyerting addi
b into the oorresponcung adds of series a.

e. Dibasic adds represented hj the formula CH^^-^O^ The adds of
repiesent the adds of series b, in which 2 at. hydrogen are replaced by an
of oxygen.

OxaHc add . . . C«BPO«

]S£alonic „

Sncdnic „

Lipio „

Adipic „

Fimelic acid . . . C".
Suberic „ . . . Gf

Anchoic „ . • . C!
Sebadc „ . • • G"

. C»H*0«
. C*H«0*

These adds are, for the most part, products of oxidation. They are solid a
temperatures, and are not Tolatile without partial or complete decompositi*
of tnem are decomposed by heat into carbonic anhydride and a monoba
series a.

C«H*0* - C«H<0« + C0«.

MaloDic acid. Acetic acid,
(jeyeral of them also produce acids of series a, when ftised with excess c
hydrate; the reaction is accompanied by erolution of hydrogen (G<
Suberic and sebadc adds heated with a great excess of baryta^ lose the c
of 2 at. carbonic anydride and yield the hydrocarbons 0*H** and C^*';
bable that other adds of this series would be decomposed in like manner i
treated. TRiche.)

Pentachloride of phosphorus reacts on the adds of this series, produc
the corresponding anhydrides, which are afterwards conyerted by exec
chloride into chlorides of the formula C»H«»-*0«C1* ; *. g.

1°. c*H«o« + pa» - c*H*o» + 2Ha + poa».

N , -^ > r— '

Sacdnic Socclnic

acid. anhydride.

2°. C*H*0« + PC1» » C*H*0*C1« + POCl*

Succinic Chloride of*

anhydride. tucdnyl.

There is a certain number of adds which do not enter into any of these ti
but which are related to certain members of them in the same way that th<
longing to the .different series are related to each other. For instance, glyc
CHH)\ differs from glycollio acid, G*H«0*, in the same way that the ki
from acetic add, C^H^';. namely, b^ containing one more atom of oxy
just as bromacetic add when boiled with oxide of silyer produces bromide oi
glycollic add —

C«BPBrO* + HAgO - C«H*0« + AgBr

Bromacetic Glycollio

add. add.

ACIDS.

bomaeJ^ooIlie add, wlieii similarly treated, yields bromide of ailTer and gljozjlio
aeid(Perkin and DuppaX —

C*H*BrO« + HAgO = C*H«0« + AgBr.

Bromo^lrcoUIo

Olyoxjlie

Similuiy, Uieie is the same difference between glyceric add, CH'0\ (bomologoos
vith gl^Qzylic add) and lactic add, G"H*0*, that there is between lactic add and
propionic add, CHH)*. Again, malic and tartaric adds, C^H*0* and O'H'O',
differ from succinic add ty containing respectiyely one and two atoms more oxygen
asd thej can be eonyezted into socdnic add by heating them with hydriodie aad^ in
the ssDie wajr that lactic add can be conyerted into propionic acid (Schmidt); moreoyer,
dibnmoaiiccinie add is decomposed, when boiled with oxide of silyer, into bromide
of Bilker and tartaric add, jnst as dibromacetic add is decomposed under similar
dreomstanees into bromide of silyer and glyoxylic add (P erkin and D npp a ). The
SUM rdatum that exists between malic and succinic adds exists also between their
homnlngnfis, tartronic and malonie-adds CH^O and C'H^O\ but in the case of
these adds, the conyerdcm of one into the other has- not yet been effected. There is
little doubt that these adds — 'glyoxylic and glyceric, tarteonic and malic, snd tartaric
— roproocnt homologous series ronning parallel with the three first described, but of
which the other terms are as yet unknown.

The relation of all the series of adds, of which we haye yet spoken, to each other
and to tile alcohols homologous with common alcohol, glycol, and glycerine, is shown
in the following Table, giying the general formulte of each series. It will be seen
that of the formulas written one aboye another, each contains one atom of oxygen
more than the formula next aboye it, and that of the formulse written in the same
horizontal line^ each contains two atoms of hydrogen less, and one atom of oxygen
more, than the one directly to the left of it. miere known, a special illustration of
each geneoral formula is giyen«

Mooatomie.

Alcohols.

Acids.

C»H*i+«0
Fropyttc^ (PH*0.

Monobulc*

Propionic, C»H«0«
and acids of lerlet a.

OH»n-»03
PyniTic CSH^Oa?

C»Haa-*0< ^

Diatomic.

OHOQS

Lactic, C^fWfi
and acids of series b.

Dibasic.

Malonic, C?WQ*
Succinic. C^HfiO^
and adds of series e.

;C«Ha»-*0» '
Mesoxalic, CHSQ'

Triatomic.

CaBSii4-tO>
Glyoerin, CB^OS

CaH«"0«
Glyceric, CH^O*

C«H*i-«0»

TartTODic, C»H<0»
MaUc, C4H«0»

Tribasic.

'cnH«i»-«0*

Tetntomie.

C*B*ta-l-tO«

GoH«H^O>

C«H«ii-»0«
Tartaric, C4H«0«

Citric, CfiR^Or

Another series of adds is represented by the gemenX formula OH'^^-'O*. They
am mmobasic like the adds of series a, but differ from these by containing 2 atoms
las hydrogen combined with the same quantify of carbon and oxygen. None of
them haye yet been reiy thoroughly inyestigated, and the empirical composition eyen
daome of them is still open to discussion.. The terms of this series hitherto more or
k« known are —

add

Acrylic
Ciotonie
Angelic
Pyrolerebie ,«
DamaTmie »

Campholic add
Monngic „
Hypogseic „
OlJo
Brassio

E 3

»t

C"ffH)*
C»»H«0«

CisHMQ"

ACONITIC ACID.

Thd following dibasic acids represented by the general formula C"H
related — so far at least as composition is concerned — to the last series^ :
manner as the acids of series c are related to those of series a.

Fumaricacid
Gitraconici
Itaconic > acids
Mesaconic)

C*HW

Terebic .
Camphoric

There are still two other series of adds, presenting the same mutual i
the series a and b, seyeral terms of which have been yery folly studied. T

1. Monobasic acids of the general formula OH*"""^'.

Benzoic acid , CH^O*

ToluyUc „ (?H»0«

Cuminic „ C'«H'*0«

2, Diatomic acids of the general formula C'H^-H)'.

Oxybenzoic acid C'II*0*

Oxytoluylic „ (?H?0*

Phloretic „ OH^K)'

Oxycuminic „ C*«H"*0*

The position which a few of the yet remaining organic acids occupy
to the series already recognised can be indicated with tolerable certaint;
greater number are stiU so imperfectly known that they cannot be indue
classification which is not entirely articifial and empirical — G. 0. F.

ACOVZTZO ACZD. C«H«0« -(^'^^'^^'JO' [or C"J5r«0'«]. E^

CUridio Acid, (Gm. xii 408; Gerh. ii. 110; iii 960; iy. 922.)— An
in the roots and leaves of monkshood (Aconitum Napdlus) and other aeon
the herb of Delphinium Consdida^ collected after flowering. It is also prod
metamorphosis of citric acid under the influence of heat. It exists in the
aconitate of calcium, which crystallises out on evaporating the juice, and
of its insolubility may by freed from the colouring matters and other im;
washing with wat«r and alcohoL The aconitate of calcium is then dissolved in
nitric acid, and the fllterod liquid is precipitated with acetate of lead. Th
of lead, after being well washed, is decomposed by hydrosulphuric acid, tl
of lead filtered o£^ and the solution which contains the aconitic acid is evi
dryness, and the residue treated with ether, in which the acid dissolves,
impurities.

To obtain it from citric add, the acid is treated till it ceases to give off h
vapours; and the residue dissolved in alcohol is treated with hydrochloric ad*
aconitic ether is formed, and separates on addition of water, as an oily li<
by treatment with potash is converted into aconitate of potassium. T
next converted into a lead salt, and the add is liberated by hydrosulphuiii
the preceding process.

On evaporating the ethereal solution, it is left as an amorphous mass, t
in water, alcohol, and ether. When heated to 160^ it is converted into an
which is itOGonio acid, C«H«0« « C*H«0* + CO*. It is distinguished fr
add by being more soluble in water, and from maldc acid by not crystallis

Aconitic acid is tribasic, and forms three classes of salts, viz. C^H'M'O*; C£
and C'H*(MK*)0'. The aconitates of ammonium, potassium, sodium, mag
zinc, dissolve readily in water ; the rest are insoluble or sparingly soluble. '
aconitates form with solutions of lead and silver, white flocculent predpitate
not become crystalline either by ebullition or after prolonged immersion in
whereas the lead and silver precipitates formed by fiunaric and malei
crystalline.

With ammonium and potassium^ aconitic acid forms salts, corresptmdin^
the three formulse above given; with sodium^ a disodic and a trisodic salt.
ofoaldumy C*H'Ca*0* + 8H*0 ? occurs in large quantity in extract of aconi
also be prepared by dissolving lime in aconitic acid, or by precipitating
calcium with aconitate of sodium. It dissolves in 99 parts of cold water, m
in boiling water. The solution evaporated at a gentle heat, and withou
yields a gelatinous mass which dries up to a gum ; but if a few ciystals of
introduced into the solution, the whole is deposited in delicate crystals. J
manganese^ C*H"Mn*0* + 6HK), is obtained by boiling the acid with cj
manganese. Small rose-coloured octahedrons, sparingly soluble in cold wat4
taie of lead^ 2C*H*Pb"0« + 3H*0, is sparingly soluble in boiling water, ai
fi'29 per cent, water at UO^,— Aconitate of silver, C^»Ag»0«. Nitrate of s

ACONITINE. 55

pMC^tited by tii« free acid, but with the alkaline aoonitates it fbnns a white,
juuMphoaa, spaiinglj aoloble precipitate^ which is partly zedaced to the metallic state
by boiling with water.

Je(nuiate of Etkyl^ CHXG^'VK)*, is prepared by diasolyiii^ aconitic acid in fiye
timee its weight of absolate aloonol, and saturating the solntion with hydrochloric
add. On addition of water, the ether separates in the form of an oily layer.

It is a colonrlees liquid, haying an aromatic odour, and yeiy bitter taste. Boils at
USP, and has a density of 1074, at 14^

Jamitamlic add or Phenyl-acomtamio add, C»«HWO* = q j^^^*^)"''^^''^"

!-M"TT4
■n , three of the hydrogen-atoms in the am-
monium being replaced by the triatomic radicle, aoonityl, and the fourth by phenyl.
It is obtained by the action of water on the (not yet isolated) compound, C"H*N0*C1,
prodooed by treating citzanilic (phenyl-citramic) acid with pezchloride of phosphorus;
probably thus :

CWH"NO» + 2Pa» - C>*HW0«C1 + 2P0a« + 3HC1;
>— — , — — '
Citranllic add.

and C»«H*NO«a + H«0 = C«H^O« + Ha

When 1 at. citramlic add is mixed with 2 at perchloride of phosphoros, added
hj small portions, and the action is assisted at intervals by a gentle heat, the whole
di9B<^Tes, forming a yellow liquid; and on treating this liquid with water, hydro-
chloric acid is evolyed, and aconit&nilic acid separates in the form of a soft substance,
which, by solution in hot water and cooling, may be obtained in small yellow needles,
but cannot be rendered colourless eren by repeated crystallisation. The add dissolyes
^)aring^y in water, easily in alcohol, and Tery easily in aqueou^ ammonia ; and the
ammoniacal solution mixed with nitrate of silver, yields rose-coloured flakes of the
nlver-saU, CP-H»AgNO*. (Pebal, Ann. Ch. Pharm. xcviii. 83.)

Jeonitodiaml or Diphenyl-aeoniUhdiamide, C'«H>«N«0« - N« (C«H»0«.y"(C^7.H,
is prodoced (together with aconitanilide), by the action of aconitic add upon aniline :

cmny + 2(yRV « C»«H"N«0« + 3H«0.
also by the aetion of ozychlorodtric add upon aniline :

C^HK?1« + 2C«H»N - C»H"NK)» + 3H«0 + 2HC1.

It is insoluble in water, veiy sparingly soluble in cold alcohoL From solution in a
large quantity of boiling alcohol, it oystallises on cooling in slender, pale yellow needles.
(PebaL)

JemntanOids or TriphmyUaeonito-trtamide, C»*H«N»0« « N»(C"H»0«)'''((>H»)».H«,
appears to be formed simultaneously with aconitodianil, by the action of aconitic add
or oxycblorodtric add on aniline :

C«H«0- + SC-H'N - C«<H«»NK)* + 3H»0
and C*BK)«C1« + 8C«H'K i» C"H«NK)» + 8HK) + 2H(X

It is an amorphous substance, insoluble in water, but reir soluble in cold alcohol, and
is thereby easily separated from aconito-dianil. (PebaL)
The amides of aconitic acid have not yet been obtained.

ACNMRTIHB. C"H«NO* [or C"-ff*'A'0"]. (Geiger, Ann. Ch. Pharm. viL 269 ;
Horson, Pogg. xliL 176; t. Plant a, Ann. Ch. Pharm. Ixxiv. 245.)— The alkaloid
eontained in the Aconitum Napdlus, and probably in all the acrid aconites. It is
obtained by exhausting the leaves with alcohol, saturating the extract with milk
of ^i^f*^ separating the lime by sulphuric add, evaporatins the filtered solution of
sulphate of acontine at a gentle heat to expel the alcohol, then diluting with water,
aaa trcating the solution with carbonate of potassium, which precipitates impure
aoonitine. The product is purified by redissolving it in alcohol, treating the solution
with animal charcoal, reconverting the base into sulphate, again decomposing this
•alt with hydrate of lime, and treating the predpitate with ether, which dissolves
nothing but the aconitine.

Pure aoonitine is depodted from solution in dilute alcohol in white pulverulent
grains, or sometimes in a compact, vitreous, transparent mass. It is inodorous, but has a
penistent^ bitter, and acrid taste. It dissolves sparingljr in cold water, and in 60
parts of boiling water, forming a stron^^Iy alkaline solution. It is very soluble in
aleohol, less in ether. At 80^ it melts mto a vitreous mass, without loss of weight ;
at 120^ it tnma brown, and at a higher temperature suffers complete decomposition.
It is disBolTed without colour by nitric add. Sulphuric* adi^ ooliouis it first yellow,

B 4

56 ACONITYL — ACROLEIN.

tJien Tiolet ; tmctuie of iodine formB with it a kermes-colonred precii)itate.
tensely poiBonous, ^ of a grain sufficing to kill a sparrow in a few minutes,
a grain killing it instantly.

The salts of aoonitine do not crystallise readily. They are not delique
dissolve easily in water and alcohol. The solutions yield a precipitate of
with alkalies. The hydroehlorate, C"H<»N0'.2HC1, is obtained by passing d
chloric acid gas over dry aconitine. Its solution is not precipitated by c
platinum, but yields a white precipitate with chloride of mercuiy, yellow wit
of gold, and also with picric acid.

CH'O' ; the triatomic radicle of aconitic add and its d

A name given by Laurent to the hydrocarbon, OH*. (See A

C»H<0 [or C*H*0^. (Redtenbacher, Ann. Ch. Pha
114; Oeuther and Cartmell, ibid, cjdi I ; Hiibner and Geuther, ibid.
Gm. iz. 365; xii. 660; Gerh. i. iy. 779, 914.)— This body constitutes the a
ciple produced by the destructire distillation of ffttty bodies, resulting in faci
decomposition of fflycerin. It is also produced by the action of platinum-b!
a mixture of acid chromate of potassium and sulphuric acid on allyl-aloohol, bei
the aldehyde of the allyl series. (Cahours and Hofmann.) (See Aixtl

Acrolein is best prepared by distilling in a <capaeious retort a mixture ol
and add sulphate of potassium, or phosphoric anhydride. When phosphoric i
is nsed, the distillate consists entirely of acrolein ; but the contents of 1
are very apt to froth over. With acid solphate of potassium, the distillation
but the acrolein is contaminated with acrylic add, sulphurous add, and o
ducts. The distillate is collected in a receiver kept very cold, and provi
a long discharge-tube passing into the chimney in order to cany off the
which are intenselj^^ irritating to the e^es. To purify the acrolein, it is digc
oxide of lead, which removes the acid impurities, then rectified in the wi
dehydrated over chloride of calcum, and again rectified. As acrolein oxid
rapidly by contact with the air, all these operations must be conducted with
of dry carbonic add gas passing throueh the iq)paratus. (Bedtenbacher.'

Hiibner and Genther distil 1 pt. of glycerin with 2 pts. of add sulphate off
over an open fiame, the bottom of the flask being protected by wire-gan
quantilr^ of oxide of lead being placed in the receiver to neutralise the add
According to these chemists, the process consists of two stages, the add si
potassium first dissolving in the glycerin, forming glvcerosulphate of potass
elimination of water, so tiiat the fiiist portion of the distillate consists ohiefljp
with but little acrolein ; but, afterwards, when the liquid becomes more con
the glycerosulphate is decomposed, and acrolein passes over with only a smal
of water. This latter portion of the distillate is subsequently purified as ii
bacher^s process.

Acrolein is a colourless, limpid, strongly refracting liquid, lighter than v
boiling at 62^4 (Hiibner and Genther). Vapour-density 1*897. Its va|
intensely irritatuig, that a few drops diffused tluough a room are suffident
the atmosphere insupportable. It bums readily with a dear bright fiame. Il
in about 40 parts of water, and very readily m ether. The solutions are
first, but grskdually torn add by contact with the air.

Acrolein cannot be preserved long, even in dosed vessels, as it chax
taneously into a fiooculent substance called by Redtenbacher disacryl, and m
into a resinous substance, disaeryl-resin. It sometimes solidifies immedii
being prepared, even in sealed tubes. It undergoes the same transformat
water, wmch at the same time becomes changed with acrylic, formic and ac
Vapour of acrolein passed through a redrhot tube is decomposed, with foi
wi^er and deposition of charcoal.

Caustic alkalia convert acrolein into resinous products. By oxidising a
converted into acrylic add. It reduces oxide of silver with considerable'
of heat, forming acrylate of silver, which remains dissolved. Nitrate of sl
with aqueous acrolem a white curdy predpitate (probably C*H*AgO) which,
gradually decomposes, yielding metallic silver and acrylate of silver. On
few drops of ammonia, and boiling the liquid, the silver is immediat^sly re<
not in the specular form bb with aldehyde. Nitric acid attacks acrolein
converting it into acrylic add. Btrong sulphuric acid blackens it, giving off t
anhydride at the same time. With chlorine and broinins, it forms hea^
gether with hydrochloric or hydrobromic add. Perchloridc of phosphi
violently on acrolein, forming dichloride of allylene C»H\C1* (see Aixtl
another oily liquid which appears to be isomeric with it. With acetic am
unites directly, fermingthe compound C'H*O.C*H"0*, which is identiciU

ACRYLIC ACID. 57

mpeci vith the oompoiiiid resnltmg from the action of acetate of dilTer on dichloride
of alljlene (Hnbner and Gent her), and may therefore be regarded as diaeetate of
ailjlene (0»H7'.(0»H«0)«.0».

AcroUm-miinumia. C«*H«N«0« « C»*H>«N«0« H«0. Acrolein acts ationgly on
ammoniis fbinning a solid compound (first obtained by Bedtenbacher) :

4Cra*0 + 2NH« « C>«H*N*0« + HK).

It k best prepared by gradually adding a saturated solntion of ammonia-gaii in alcohol
to an aleoh<mc or ether^ solnhon of acrolein, and precipitating by addition of ether.
It IS a white or yeUowish, amoiphous, odonrless compound 'vmich turns brown at a
gentle heat and b^ins to decompose at 100^, giving off volatile basic products. In
the moist state it dissolves readily in cold water and warm alcohol ; less in hot water.
It diasolTSB readily in addi, and is precipitated therefrom by alkalis and alkaline
caibonates. Hence it appears to be a base. Its solution in hydrochloric acid forms
with dichloride of platinum, a light yellow precipitate containing, when dried at 100^,
C«H»!S»0». 2HCL 2PtCl«, or C«H»»NO.HCa.Pta« . (Hiibner and Geuther.)

Acrolein with Acid. Bulpkite of Sodium, — When acrolein is poured into in aqueous so-
lution of acid sulphite of sodium, its odour is destroyed, and by evaporation over the
water^bathf a brown deliquescent syrup is obtained which does not deposit crystals,
and from, which neither acrolein can be separated by boiling with carbonate of sodium,
nor salphnroas acid by boiling with sulphuric add* (Hiibner and Geuther.)

HydroekloraU of Acrolein^ CH^O.HCL Produceil by passing dry hydrochloric
acid gas into anhydrous acrolein in a vessel surrounded by cold water. The viscid
product, washed and dried over oil of vitriol in vacuo, yields hydrochlorate of acrolein
as a mass of velvetv czTstal^ which melt at 32^ into a thick oil, having the odour
of rancid fiit. It is insoluble in water, but readily soluble in alcohol and ether, on
the eraporation of which it remains as a thick oiL It is resolved by heat into
acrolein and hydrochloric add. It is not apparently altered by boiling with water,
or 1^ the action of dilute solutions of the alkalis. Heated with ammonia to 100^ in a
sealed tube, it yields chloride of ammonium and acrolein-ammonia. Strong hydro-
chloric acid decomposes it, settingthe acrolein free ; a similar action is exerteid by
dilute sulphuric or nitric add. Hydrochlorate of acrolein in alcoholic solution does
not combine with dichloride of platinum, and very slowly reduces a boiling ammo-
niaeal solution of nitrate of silver.

Gaseous hydriodio acid passed into acrolein exerts a violent action, attended with a
hissing noise like that of Md-hot iron plunged into water. The product is a resinous
bo^ which is insoluble in alcohol, etner, adds and aJkalis, gives off iodine when
heated, and yields a small quantity of free iodine to bisR^phide of carbon.

Mbtacsouok. Hydrochlorate of acrolein heated with hydrate of potassium gives
off hydrogen, and yields an oily distillate, which solidifies in magnificent colourless,
needle-shaped crystals, consisting of metacrolein, a compound isomeric or more pro-
bably polymeric with acrolein. It is lighter than water, has an aromatic odour, and
a cooling taste with burning after-taste. It melts at ^0^, solidifies at about 46^, or
volatilises a little before melting, so that it may be distilled with vapour of water.
By heat, it is dianped into common acrolein. It is not affected by dilute alkalis,
bat when heated with mineral adds it is changed more or less into acrolein. In
a stream of dry hydrochloric add gas, it melts and is converted into the hydrochlorate
of acrolein above described. Hence it is probable that the compound so named is
realW a hydroeklorate of metacrolein, perhaps C«H"0'.2HCL

^^riddaie of Metacrolein is produced by passing dry hydriodie acid gas over meta-
crolein, as a heavy yellow Uquid which resembles the hydrochlorate in taste and
appearance, and after washing in water, shows a tendency to cxystallisc at ordinary
temperatures. When placed over oil of vitriol, it decomposes, turning brown and
giving off iodine.

Hydriodie add gas acts violently upon acrolein, produdng a resinous substance
which is insoluble in alcohol, ether, adds and alkalis, and gives jap iodine when.
heated or when digested with bisulphide of <!arbon. (Geuther and Cartmell.)

AOMTKEO AOI]>. C»H*0*«C«H»O.HO (or C'^^O*). (Gm, ix. 369; Gerh.
783 ; iv. 914.) AcroUio acid^Tins acid, discovered by Bedtenbacher, is produced bv
the oxidation of acrolein. The best agent to employ is oxide of silver, which, when di-
gested with acrolein, yields a deposit of metallic silver, and a solution of aciylate of
nlver. This salt is decomposed by hydrosulphuric acid, and the acrylic add thus set
free is purified by rectification. It is necessary carefullv to cool the vessel during the
decomposition of the silver salt; otherwise^ the heat develoi)ed is so great that an
expk>6ion results. The add is likewise obtained by the action of chromic add on
oxide dT allyl. (Hofmann and Cahonrs.) (SeeAixTL.)

58 ADIPIC ACID.

When ponfied, it is a eolourless liquid, of an agreeable, slightly emp
odour. It ifi mifldble with water in aU proportiona, and its boiling-poin
mediate between that of fonnic and acetic acids.

It is a monobasic acid, its salts haring the formnla, CWH«M)0«. Th<
resemble the formates and acetates, and are generally rery soluble in water.

AcrylaU of Sodium. 2C»(H*Na)0« + 6H*0, is obtained by saturating the
carbonate of sodium and evaporating. It crystallises in transparent prunns.

AcrylaU of Barium. C*(H*Ba)0*, is also a soluble salt.

Acrylate of Silver, C'(H*Ag)0*, forms white needles, having a silky li
Teiy soluble in water.

AcrylaU of Ethyl is obtained, though not in the pure state, by distilli]
add, or its sodium or barium-salt with alcohol and sulphuric acid. (Kedten

ACTZVOUITB. A variety of Hornblende (q. v.)

See BiAicoMB. — A9AM AMTIVB SPAS. See Co:

at or ASOFTSX* A piece of tube of more or less conical f
to elongate the neck of a retort, and to connect it with a receiver.

(See Cohesion.)

K&ATS. (See Suite.)

roVB B9AMm (See OBELBMm and Saussubitb.)

A compact impure felspar, better known as petrosHex.
from jaspar, which it otherwise much resembles, in being fusible before the

ASZPZCAOXB. C^»0* = 0« |9^^I[or(7"5^0»-(7»«J5r"0«.2J5rO]

acid forminff the fifth term of the series CH** - '0^ the lowest term of which is o
CB.H}*, and the highest at present known, sebadc acid, C"H**0^. It is pi
the action of nitric acid on oleic add, suet, spermaceti, and other fatty bodiei
pare it, tallow or suet is boiled in a capadous retort with nitric add of ordinal^
whidi must be frequently renewed, and the distillate poured back till the fa
disappears and crystals separate on cooling. The liquid is then evaporatec
water-bath till it solidifies in a crystalline mass on cooling ; this mass is w
funnel, first with strong nitric acid, then with dilute nitric acid, and lastly
water; and the acid is finallypurified by ciystallisation trom boiling water (M i
Other adds of the same series are doubtless formed at the same time ; but
to Malaguti, the crystals obtained in the manner just described have all
appearance, excepting the very last Wirz (Ann. Oh. Pharm. dv. 267) ol
acid, together with several other members of the series, by the continued actio
add on the solid fatty acids of cocoa-nut oil The action is continued i
weeks till the mass solidifies to a crystalline magma. This product is r<
water into a mixture of several adds of the above series, and a heavy oil
adds are separated one from the other by fractional crystallisation from
alcohol, and lastly by fractional crystallisation of the silver-salts. (See Ancb

The add separates from its aqueous solution in crystalline cmsts compos
white, opaque, nemispherical nodules, which appear to be aggregations of small
According to Wirz, these crystals dried at 100° contain water of crystallisa
formula being 20«H'«0* + H*0 [anaL 462, 46*4 and 47*8 p. c carbon, 6
p. c hydrogen ; calc 46-4 0 and 7*0 H]. At 140° they melt and give
leaving the anhvdrous add CH**0* [analysis, 48*2, and 48*3 0; 6*8 ai
calc. 49. 3 0 and 6*8 H] ; which soon afterwsrds sublimes in long slender n
sublimed acid gave by analysis 49*6 0 and 6*6 HI.

100 parts of water at 18° dissolve 7*73 of the crystallised add: a h(
which deposited nystals abundantly on cooling, still retained 8*61 pts. of 1
100 pts. at 18° (Wirz). The add dissolves very readily in hot alcohol and

The adipates, O'H'MK)^ are for the most part soluble in water and cryi
insoluble in alcAiol. The ammonium-BaM crystallises in needles (Laurent,!
The barium-salt dried over sulphuric acid, forms opaque warty masses not
water of crystallisation (Wirz). The strohtium-sftlt forms microscopic m
taining 2C^«Sr«0* + 3H*0 (Laurent). The calcium^alt resembles the I
in appearance, but contains 1 atom of water rC*H"CaO* + H*0] which ii
between 100° and 200° fWirz). The siiver'Salt, C«H»Ag*0<, obtained by pr
the ammonium-salt with a considerable quantity of nitrate of silver, i
powder.

Adi^ of Ethyl, C^O* (C^*)« obtained by saturating the alcoholic
the add witii hydrochloric acid gas, \s a yellowish oil of sp. gr. 1*001 at 2(
boilfl^ with decompodtion, at 230°. It has a strong oaour of apples a

ADIPOCERE— AESCULIC ACID. 59

csoatic tiMte. Chloiine decomposes it| giTing off hydrodhloiic add and fonning a
liseoofl mass. (MalagntL)

AMFOOSRB. (From adeps^ &t; and eera, -wax.) A peeollar wliite substance, pro-
duced bj the decomposition of animal matters under the influence of moisture and in
situations from which the air is excluded. It was first found bj Fourcroy in the Cimeti^e
des Iitnocenis at Paris. A number of coffins had been piled one upon another, and
lemained interred for about 20 years. The bodies were found compressed, as it were,
at the bottom of the coffins, and oonyerted into a soft white substance resembling
dieese, which bote the imprints of the linen in which they had been wrapped. This
matter endoeed the bones, which were broken on the slightest pressure. It was
fixmd to eonsiat diiefly of maigarate of ammonium together with the margaxatea of
potaanam and caldum.

(See Fklspab.)

(See Edblfossitb.)

or ABCnnuor* (Handwort d. Ghem. i 169.) A mineral of the
angite family, occurring in the neighbourhood of Sreyig in Norway, sometimes in reiy
large and well-defined crystals belonging to the monodinic system, and haying the
general diaxacter and dearage of augite. Colour greenish-black to leek-green. Lustre
Titreoua* The edges exhibit yarioua degrees of translucence, down to complete
op§a.tj, Sp. gr. 3*43 to 3'60. Hardness about that of orthodase. The mineral con-
tains a considerable quantity of iron, partly in the state of protoxide, partly of sesqui-
oxide, besides alumina, lime, magnesia, and soda, sometimes ako protoxide of man-
ganese and potash, associated with silica, and sometimes with titanic add. The
fiKmula is not perfectly established, but it is probably of the general form,

8(M«O.SiO») + «(M«0«.3SiO«) = 3M«SiO« + «M'Si«0«

TAJTTBMBm (See Cabbonio Acn> and Water.)

(See Mbtbobttb.) — ABBOBXTS. (See PrBAsoTBiin.)

(Handwort. d. Chem. i. 192.) A mineral occurring at Miask in
file Ural, and consisting, according to HartwaU's analysis, of 56 titanic acid, 20
sovonia, 15 cme oxide, 3'8 lime, 2*6 ferric oxide, 0*5 stannic oxide (making together
97*9), but according to Hermann's more recent analysis, of 25*90 titanic acid, 33 '20
eolumbic add, 22*20 eerie oxide, 5'12 oerous oxide, 5*45 ferrous oxide, 6*22 oxide of
lanthanum, 1-28 yttria, and 1*20 water (« 100*57). By its oystalline form and
properties, as well as by its chemical constitution, it appears to be dosdy related
to Pc^ymignite, Folycrase, Euxenite, &c

AaBCVXanw or BSCiriATXar. C*H*0\ or C^H'O^. A product of the de-
eompodtion of aesculin, discoyered in 1853 b^' Buchleder and Schwartz (Ann. Ch.
Pharm. IxxzyiL 186; Ixxxviii. 366), and independently by Zwenger (ib. xc. 63).
It is obtained; 1. By boiling lesculin with hydrochloric or cUlute sulphuric acid. The
liquid on cooling depodts a crystalline mass which, when washed with cold water,
dissolTed in hot alcohol, and treated with acetate of lead, yields a lead-compoimd of
aeaculi^tin from which the latter ma^ be separated by hydrosulphuric acia.—2. A
cold saturated solution of ssculin mixed with emulsin (the fermenting principle of
street almonds) and left in a warm place, deposits after a while, small ciystals of
cscnletin.

Asculetin forms shining needles or scales which are bitter, sparingly soluble in
cold water and alcohol, more soluble in the same liquids when warm, but nearly in-
BoluUe in ether. The aoueous solution is fluorescent like that of sesculin (q. vX but
in a orach less degree ; tne fluorescence is howeyer considerably exalted by addition
of a small quantity of carbonate of ammonium.

When gradually heated, it giyes off 6*64 p.c water at 100, melts aboye 270^, and
then distils with decompodtion. Hydrochloric acid dissolyes it without alteration ;
nitric add conyerts it mto oxalic add. It is also decomposed by hot concentrated
sulphuric add. It dissolyes in alkalis, forming solutions of a fine gold-yellow colour ;
its solution in boiling aqueous ammonia deposits on cooling a yellow substance, which
decomposes rapidly in contact with the air. .Sscoletin imparts a dark green colour
to feme salts. It reduces nitrate of silyer at the boiling heat ; predpitates red oxide
of copper from cupricssJts dissolyed in potash ; and forms with acetate of lead a yellow
predpitate containing C*H*Pb*0*.

AMBCUJbEC JELCTD* Obtained as a wbite precipitate by boiling saponin (a
substance contained in the horse-chesnut and in many other plants) with dilute hydro-
chloric or sulphuric add, or by boiling saponin with potash-ley and decomposing the
xesolting eescnletate of potasdum with an add. It is insoluble in water, but soluble
in alodholy and is depodted therefrom in granular crystals on cooling. Nitric acid

60 AESCULIN-AGALMATOLITE.

transforms it into a yellow resinons nitro-componnd. It is but a weak a^
alkaline SBecnlateB are soluble in water, and ciystallifle from solution ii
The formula of sscnlic acid, according to Fremj (Ann. Ch. Phjs. [SJ lyiii
C»H«*0". BoUey (Ann Ch. Pharm. xc 211), who calls it sapogentn^ asf
the formula C"H**0^ According to Bochleder and Schwars (Ann. d
Izzxviii. 367) it is identu»l with chinovatio acid CH**0'.

AMACUZaM or BSCmLZV. C^^R^O'*, or C**H*'0». (Gerh. iv. 29
wcrt d. Chem. L 196.) A crystalline fluorescent substance obtained from
of the horse-chestnut {AesctUus Hippocaatanum) and of other trees of tl
Aescultts and Pavia, It was first observed by Frischmann, more closely inyest
Trommsdorff the younger in 1835 (Ann. Ch. Phann.xiT.198), afterwards by Bo
and Schwarz (ibid. Ixxxvii 186 ; Ixxxviii 166), and by Zweneer (ibid, a

The aqueous extract oiTthe bark is precipitated with acetate of lead ; the p
is washeo, suspended in water, and decomposed by hydrosulphuric add ; and
is filtered at the boiling heat. Or better : the aqueous extract is mixed wit
of alum and excess of ammonia ; the liquid filtered to separate the fawn-col(
cipitate of alumina mixed with the colouring matter of the bark ; the yellowi
neutralised with acetic acid and evaporated to diyness ; the residue consisti
sulphates and acetates of potassium and ammonium, boiled with a little stroi
to extract the SBSCulin ; the alcoholic filtrate evaporated till it crystallises
flesculin thus obtained, is purified by pressure between bibulous paper, and rec
tion. (Bochleder, J. pr. Chem. IxxL 414 ; Chem. Otsz. 1868, 96.)

Aescnlin forms colourless, needle-shaped crystals. It is inodorous, ha
taste, is sparingly soluble in cold water and alcohol, more soluble in the sai
at the boiling heat, and nearly insoluble in ether.

Aeflculin is coloured red by chlorine ; it forms a yellow precipitate with i
of lead, and reduces the protoxide of copper to suboxide, like glucose. It me
and decomposes at a somewhat higher temperature, yielding various produ
which is a small quantity of sesculetine. ^iled witli hydrodiloric or dilute
acid, it is resolved into sesculetin and glucose :

CJ«iH"0" + 3H«0 « Cra«0* + 2C«H>*0«

The aqueous solution of esculin is highly fluorescent (see Lxoht), the refli
being of a sky-blue colour. Nearly the same fluorescent tint is ffldiibited
ftision of horse-chestnut bark. The colour is however slightly modified by ti:
of another fluorescent substance, pavHn^ recently discovered by Prof. St ok
Soc. Qu. J. xi. 17). The latter is separated from eeeculin by its greater sc
ether. Its solution exhibits a blue-green fluorescence. Aesculin and paviii
exist together in tlie barks of all species of the genera AbcuIus and Pav
being however more abundant in the former and paviin in the latter (et
The fluorescence of both aesculin and paviin is augmented by alkalis, but de
acids.

(See Cbtyim)

LBT1IIJ«» &c (See Ethbb, Ethti^ &c.)

An old pharmaceutical term applied to various mineral pi
of black colour or approaching thereto : e, g. Aethiops antimoniaUs ol
tritnratinff together mercury, smphide of antimony, and sulphur ; AetMop
black o^e of iron ; Aethiop9 mtneraliSf black sulphide of mercury obtaine
rating mercury with sulphur; Aethiopa narcotieua (or hypnoiicus,) sulphi<
cury obtained by precipitation ; AeiMopaper se, the grey powder obtained h
impure mercory to the air.

ABTBOXnUUnr. The yellow colouring matter of the flowers otJi
Linaria,

(See Chbmtcal Afstnitt.)

(See Aphtonitb.)

[from SyoXfiOf an image ; and xtOos^ stone] ;
This name was originally given to a soft mineral or rather a numl
minerals used by the Chinese for carving grotesque flgures and idols. The
vary in colour m>m greyish-ereen to yellow and red ; thev are aU more i
and unctuous to the toudi and capable of being cut and polished.
The Chinese agalmatolites are of three kinds : viz.

1. Hydratod silicates of aluminium and potassium :

a. 9SiO«.3Al<OMK*0.3HH) « eaiC^.SAPO'.lKO.ZHO
6. 3SiOMAl*0».M*0.1H«0 - SdiO'.ZAP.dMO^.dllO

* M denotes potauiuin, todlain, cAlcium, magneiium, ttc

AGAR-AGAR— AGARICUS.

1 Hjdimted aQieates of aluminium.

a. 9SiO«.aAl*0».6H«0 - ZSiO^.lAPO^.ZffO
b. l£SiO'.4Al<0*.4E:>0 » ^aiC^.%APO^jmO

8. Hjdntad mKcattew of mAgnednxn:

16SiO«.12MgH).4H«0 = bmC^.^MgOJlHO

Then an also Beyoral European minerab -which in composition and physical oha*
aeter dosely resemble the Chinese agahnatolites.
4. AnhnatoUte from Magyag in HtDogaiy has the same composition as the Chinese

niiiienX Ij ^

A. Agahnatolite, from Ochsenkopf in the Saxon HaiZi and Onkom from Posseggen
in SalzbiD]^ haTe a composition expressed bj the formula :

9SiO«.8AlW.22lP0.3HK) « eSi(^,ZJPO'.2M0.3SO.

6. MotAer o/Diaspore, a mineral in which the diaspore of Schemnits in Hnngaiy is
inteigrown, has the composition 2, a above.

7. Pan^hiU from. Canada has a composition corresponding to the fonnnhi :

9SiO*.8Al*0».3MK>.4jHK) = ^aiC^.ZJPC^.MO.^HO

8. DmiUrSriie^ from Diana and other localities in St. Lawrence oonntj, New York,
appears uso to haTO a oonstitation resembling that of the agahnatolites.

9. JusoImi which is a hydrated silicate of aluminium, containing

{2SiO*«Al*0«.2H«0) - 4.aiC^,ZJPC^.%H0,

OMtdj icscmbles the agahnatolites in physical character.

10. NeoUit, from Eisenach and other localities, containing

©SiO»jaW.3MH).HK)- 6Aa".l^a".3if0.1^0,

also fonns masses resembling agalmatolite.

All these minerals hare a sp^ific grayity ranging from 2*75 to 2*85 ; rarely as high
ss 2*90. In TitiT-^JTift— , they are interaiediate between gypsom and calcspar. They are
mare or less translncent, nnctnons to the touch, do not adhere to the tongue, and
are easily canned and wioaghL

The tniA ag^dmatolites are 1, a; 4, 5, S, and 7 : the rest may be zegazded as allied
KpedtB. (Handw. d. Chem. L 375.)

(See TuBQVOiSB.)

or Bengal Isinglass: a dried sea-weed from Singapore, consisting
of amall transparent colourless strips, is almost completely soluble in water, and forms
a laige qoantity of thick, tasteless, and odourless jelly.

(See AxAximr.)

A genns of the order Fungi, Many fungi, especially of the genus
Jgarinu are oonmionly used as food, and it is remarkable that the amount of nitrogen
eonfeained in their dried substance exceeds that in peas and beans, which are generally
ngarded as the most nutritious of all articles of food.

The following table exhibits the percentage of nitfoffen and of ash in Tarious species
of fkmgi, as detomined by Schlossberger andDoppi ng (Ann. Ch. Fharm. lii. 106 to
120). The plants were dried at 100^ 0. The qruintily of water ayeraged about 90
parean^

jfgaricMt dfitcicfius
n

f»

glutmoiUB
canthardlut

Itrogoii*

Aih.

4-68 .

6*9

7*26 .

. 19*82

4*61 .

4*8

4*25 .

9*5

8*22 .

. 11*2

6*34 .

9-0

4*7 . .

, 6*80

616 .

5*2

4*46 .

819 .

Boktui aitrena
I/geoperdon eekinaium
JMmorua/omentarnu
Jknaiea quermna .

ThiS ash eontains a laz*^ prroortion of phosphates. The solid tissue of Amgi, for-
msfly regarded as a peculiar substance, fungvn^ is nothing but cellulose: it may be ex-
tracted by treating the fungi successiTelY with water, weak sod^-ley, hydrochloric acid,
and alcohol. Agancs were fbund by Schlossberger and Dopping to contain mannite and
fermentable sugar, but no starch. The acid contained in aearics and other ftmgi was
formerly supposed to be of peculiar nature, and called hdetic orfxmgio acid; but it
has been shown by Bolley ana Dessaignes that many agarics contain fhmaric add, some*
associated with malic, citric, and phosphoric acid.

62 AGATE —AGROSTEMMINE.

the mountain mUk^ or mountain meal, of
mans, is one of the purest of the native carbonates of lime, found chiefly in thi
rocks, and at the bottom of some lakes, in a loose or semi-indurated form.

The name of mineral agaric, or fossil meal, was also applied by Fabioni to i
a loose consistence found in Tuscany in considerable abundance, of which brid
made, either with or without the addition of a twentieth part of clay, so light i
in water, and which he supposes the ancients used for making their floatii
This, howerer, is yery different from the preceding, not being eyen of the c
genus, since it appears, on analysis, to be a hydtated silicate of magnesium mi
lime, alumina^ and a small quantity of iron. Kirwan calls it argwo-murite.

A mineral, whose basis is calcedony, blended with yariable pr
of jasper, amethyst, quartz, opal, heliotrope, and camelian. Ribbon agate o
alternate and parallel layers of calcedony with jasper, or quartz, or ameth]
most beautiful comes from Siberia and Saxony. It occurs in porphyry and
Brecdated agate ; a base of amethyst, containing fragments of ribbon agate, c<
this beautiful yariety ; it is of Saxon origin. — Fortification agate, is found h
of yarious imitative shapes, imbedded in amygdaloid. This occurs at Obt
the Bhine, and in Scotland. On cutting it across and polishing it, the interi(
parallel lines bear a considerable resemblance to the plan of a modern fortifio
the yery centre, quartz and amethyst are seen in a splinteiy mass, surroundc
jasper and calcedony. — Mocha stone. Translucent calcedony, containing darl
of arborisation, like vegetable filaments, is called Mocha stone, from the place, i
where it is chiefly found. These curious appearances were ascribed to deposi
or manganese, but more lately they have been thought to arise from mineralif
of the ciyptogamous class. — Moss agate, is a calcedony with variously coloun
cations of a vegetable form, occasionally traversed with irregular veins of r«
Dr. M'Culloch has detected, what Daubenton merely coi^ectured, in mocha i
agates, aquatic confervse, tmaltered both in colour and form, and also coated
oxide. Mosses and lichens have also been observed, along with chlorite, in vej
An onyx agate set in a ring, belonging to the Earl of Powis, contains the ch
a moth.

Agate is found in most countries, chiefly in trap rocks and serpentine,
nodules of agate,, called ^eodes, present interiorly crystals of quartz, colo
amethystine, having occasionally scattered crystals of stilbite, chabasite, and
mesoty^. These geodes are very common. Bitumen has bc^n found by J
in the inside of some of them, among the hills of Dauria, on the right ba
Ghilca. The small geodes of volcanic districts occasionally contain water
cavities. These are chiefly found in insulated blocks of a lava having a
fracture. When they are cracked, the liquid escapes by evaporation ; it is
stored by plunging mem for a littie in hot water. Agates are artificially coJ
immersion in mettdlic solutions. Agates were more in demand formerly than s
They were cut into cups and plates for boxes ; and also into cutlass and sabr
They are still cut and polished on a considerable scale and at a moderati
Oberstein. The surface to be polished is first coarsely ground by large mil
a hard reddish sandstone, moved by water. The polish is afterwards given c
of soft wood, moiBtened and imbued with a fine powder of a hard reatripol
the neighbourhood. M. Faujas thinks that this tripoli is produced by the d
tion of the porphyrated rock which serves as a gangue to the agates. The
employed agates for making cameos (see Calcedont). Agate mortars are
an^tical chemists, for reducing hard minerals to an impalpable powder.

The oriental agate is almost transparent, and of a vitreous appearance. Th
tal is of various colours, and often veined with quartz or jasper. It is mo2
in small pieces covered with a crusty and often running in veins through
flint and petrosilex, from which it does not seem to differ greatiy. Agates
prized when the internal figure nearly resembles some animal or plant. — U.

AOBDOX&. A name applied by Gaventou to a crystellisable substanc<
from liquorice-root ; identical with asparagin. (Henry and Pliss on.)

AOflTBSITB. Syn. with BisicvTrrB.

iikOftOBTBiacm. A crystalline basic substenoe obtained from th
the corn-cockle {Agrostemma Githago), The seeds are exhausted with wet
acididated with add ; the acid is concentrated by evaporation and mixed with
and the dried precipitate is treated with alcohol.

Agrostemmin crystallises in pale yeUow scales which are but slightiy
water, but very soluble in alcohol, to which they impart an alkaline react!
decomposed by boiling potash, with evolution of ammonia.

AIR— ALANINE.

. 87-31 .

36-39

• • *

4-81

. 23-73 .

16-70

. 10-70 .

5-43

. 2-79 .

1-70

. trace .

2-29

. 6-46 .

6-61

. 3-63 .

3-68

. 6-04 .

—

. 2-66 .

. 2-78

. 8-61 .

. 21-71

Tb» sahihate, dtloio-aiixate and cfakroplatiiiate of agroetemmine are OTBtaUisable;
and phoB^a^fbnDB a bulky pi«cipitate. (Schulse^ ^m. Ch. Pharm. Ixviii 360.)

Sjn. with AcicuiJTB.

_ The term "air" (Latin, aer) is now exdnaiyely employed to denote the com-

poDCDt gases of the earth's atmosphere. Amongst the older writers on science, we find
the void *'air'* made use of to designate the gaseous or aeriform condition of a body;
thu carb<»ie add gas was called " fixed air/' hydrochloric acid gas *' marine add air/'
hjdiogen gas ** inflammable air/' &c. (See Athosphxse.)

AJVOA BSFTAV8 (Creeping Bugle). (Handw. d. Chem. i. 385.) This plant,
mvn on the even ground of the Lechthal, yielded, when gathered in the beginnmg of
June, 84*3 p.c water, and 10*4 p.c. ash (a) ; that which grew on the chain of hills ad-
jounng the valley, yielded at the end of June, 81*6 p.c water and 9*5 p.c ash (6).

Potash

Soda ....

Ijime ....

Magnesia .
Sesquiozide of iron .
Manganoeo-manganic oxide
Phosphoric anhydride
Sulphuric .
Chloride of potassium
Chloride of sodium .
Silica.

, (See Efidotb.)
(See AcBTOKB.)
(See AcHSOTB.)

A variety of arsenical pyrites.
(See MAiroANSSB-GLAXcB.)

ITSB* Grantdar gyptiffm, Albdtre gypseux. The tecbnical name for
granular gypsum or sulphate of calcium. Alabaster is among the several varieties of
gjpsum "^mat marble is among carbonates of calcium, and like marble is used for sculp-
ture, especially for objects of small dimensions. The hard, fine-grained, snow-white,
tzanalnoent alabaster fiom Yolterxa near Plorence, is especially valued for these purposes.

JkabAJUTB* (See Diopsmi.)

A&ASnra. C^'NO>. (A. Streeker, Ann. Ch. Pharm. Ixxv. 29 ; Gm. ix.
434; Oerh^i. 678.) An organic base obtained by heating aldehyde-ammonia with
hydrocfanic acid in presence of excess of hydrochloric acid.

C*H»0«.NH« + CNH + Ha + H«0 = C'H'NO' + NH*C1.

To prepare it, an aqueous solution of 2 pts. aldehyde-ammonia is mixed with aqueous
bydioeyanic acid containing 1 pt. of the anhydrous acid, hydrochloric acid is added
in excess, and the mixture is Doiled and afterwards evaporated to dryness over the
water-bath. The residue consisting of hydrochlorate of alanine and a laige quantity
of sal-ammoniac, is digested in a Uttle cold water, which leaves the greater part of
the sal-smmoniao undissolved ; the solution of hydrochlorate of alanine is boiled with
hydrate of lead, added in small portions as long as ammonia continues to ^cape ; the
Uqnid is filtered ; and the dissolved lead is precipitated from the solution by sulphu-
leited hydrogen. The filtered liquid yields crystals of alanine by evaporation, and
in additional quantity may be obtained from the mother-liquor bv addition of alcohol.
Another and better method is to treat the mixture of hydrochlorate of alanine and
■d-ammoniac with alcohol and ether, in which the former only is readily soluble, con-
centrate the solution by evaporation, and remove the hydrodiloric acid by boiling with
Iqrdrate of lead.

Properties. — Alanine Cfystallises on cooling from a hot saturated solution in colour-
IsM needles having the form of oblique rhombic prisms united in tufts. They have
a peariy lustre, are hard, and grate between the tee^ At 200°, it sublimes and falls
down agun in fine snowy crptals ; when rapidly heated, it melts and sufiers partial
decomposition. It dissolves in 4*6 pts. of water at 17°, and in a smaller quantitv of
hot water ; it is very sparingly 8oliu>le in cold alcohol, and quite insoluble in ether.
The aqueous solution has a sweet taste, does not affect vegetable colours, and forms no
pKcipitates with any of the ordinary reagents.

Alanine is isomeric with ttrethane^ ladbamide, and saroosine ; from the two former
it ii distinguished by not melting below 100° ; from the last by being soluble in water,
ttid by its Dehavionr with metallic oxides.

64 ALANINE^ALBUM GR^CUM.

Pecompotiiiofu, — Alanine is not altered by boiling with dilute adds, or
It diaaolyeB in strong sulphuric acid, and the solution does not blacke:
Fused with hydrate of potassium, it gives off hydrogen and ammonia
cyanide and acetate of potassium. When its aqueous solution is boiled w
of lead, it is resolyed into aldehyde, carbonic azmy dride, and ammonia :

0»H^0« + 0 « 0^*0 + CO* + NH».

The aqueous solution is also decomposed by nitrous acid, with erolutiox
and formation of lactic acid :

C"H*NO« + NO»H = C"HW + 2N + H«0.

* 1 ' ' r— ' * r— '

Alanine. Nitroas Lactic

acid. acid.

Compounds of Jlanine. — ^Alanine acts both as a base and as an acic
directly with acids, and when boiled with metallic oxides forms oompoun(
of alanine witib 1 atom of hydrogen replaced by a metaL With hyaroehi
forms two compounds, viz. 2C'H'N0'.HC1, obtained by treating alanine wit]
chloric acid gas, and CH'KO'.HCl, produced by evaporating a solutioi
in excess of hydrochloric acid. Botn these compounds di^lve readi]
sparingly in alcohol; the latter is veiy deliquescent, but may with some
obtained in crystals. On mixing a solution of alanine in hydrochloric acid
of bichloride of platinum, and evaporating, the chloroplatinate, 2C'H7NO
crystallises in slender yellow needles, soluble in water and alcohol, ant
mixture of alcohol and ether. Nitrate of alanine, (?H*NO«,HNO« is i
evaporating a solution of alanine in dilute nitric acid, in long colourless ne
deliquesce in damp air, and dissolves veiy readily in water; less in alcoli
they torn yellow and decompose. Stdph^ of alanine is vei^ soluble in
remains as a syrupy mass when its solution is evaporated ; it may be i
cold alcohoL It is not precipitated from its aqueous solution by alcohol, bi
of ether and alcohol separat«i it in the form of a thick ffmip.

The copper-compautM of alanine, 20'H'GuNO* + H'O ciystallises fron
of alanine which has been boUed with cupric oxide, in dark blue needles
rhombic prisms. It forms a dark blue solution in water, but is nearly
alcohoL The crystals remain unaltered at 100°, but at 120° they giv
and are reduced to CHKhiNO* assumingat first a lighter blue colour, an(
cmmbling to a bluish-whito powder. The eilver-compoundf CH'AgNO*,
in a similar manner, and separates as the liquid cools, in small yellow ne<
in hemispherical groups. They assume a darker colour when exposed t
also when heated to 100° in the moist stato ; but when dry they sustain 1
jature without alteration. A solution of nitrate of silver mixed with ala
by spontaneous evaporation, colourless rhombic tables, which are decompoi
with slight detonation, and leave a residue of spongy silver. A teat
CH'FbNO'.PbHO, is obtained in colourless glassy needles, by boiling i
lead in aqueous alanine, and evaporating and cooung the solution. It :
cipitated in radiating crystals, on mixing the aqueous solution with aL
crystals dried over sulphuric acid, give off water and crumble to a powc
no longer completely soluble in water.

(See Inttun.)

A white, crystalline, resinous substance extracted from gutt
alcohol or ether. It is best obtained by treating gntta pacha with ether,
ing the resulting extract with alcohol which dusolves a yellow resin, a
white substance to which Fayen gives the name of alban. After recrystalli
absolute alcohol, it forms a white pulverulent mass, which begins to melt
perfectly fluid and tranroarent between 175° and 180°, and contracts stron
ing. It dissolves with facility in oil of turpentine, b^izol, solphide of ca
hot alcohol, and chloroform, and separates from tiie solutions m the cryst
The crystals are wetted by watery liquids. They exhibit with sulphuric aci
reactions as native gutta percha. (Pay en, Gompt. rend. xxxv. 109.)

A&BSVa. A name given by Yolckel to a white substance which, a
his observations, remains undissolved when melam ia boiled with wate
assigns to this substance the composition C^* H*N^*0^ (Aim. Ch. Phys. [2]

(See Apofetlijtb.)
Soda-felspar. (See Fslspab.)

NLBOVBI* An obsolete name for the excrements of the do
used as a remedy in medical practice. The substance contains about 79 ]
phosphate of calcium.

ALBUMIN. 65

(6eth. br. 433; Lehmann, Physiological ChemiBtxy i. 330; also
Zooehemie in Gmelin's Handbuch, Bd. viii. Pelouze et Fr^m j, Tftiit^ de Ghixnie
gen^nle, vi 67.) Albumin ia the chief and characteiistic constituent of white of egg
and of the senmi of blood, and occnis in all those animal substances which supply
the body et indiyidnal parts of it witii the materials required for nutrition and
RDOTitieo. It forms about 7 p. e. of blood and 12 p. c. of white of egg ; it is a principal
ooDstitiient of chyle, lymph and of all serous fluids. It occurs also in the juice of
flesfa, in the brain, the pancreas, the amniotic liquid, and generally in a greater op
Mnaller quantity in all the Hquids (transudates^ effused from the blood-vessels into
the edfauar tissues of the oigans, into the caTities of the body, or on to the surface.
It is inmd in the solid excrements of man and of other animals^ the quantity in-
creasing in disorders of the mucous membrane of the intestinal canal. It is not
found in nonnal urine^ but is present in that liquid in many states of disease, espe-
cially in aflections of the respiratory ofgans, which interfere with the process of
oxidation.

Albomin exists in two very distinct modifications, -viz. the soiuile form, in which
it always oeoirs in the animal body, and the insoluble form, into which it may be
bvooght by the aetion of heat» as when white of egg or blood-seram ia boiled. These
twD modiflcatioas of albumin are identical in chemical composition, the difference
between them being due, partly, perhaps, to peculiarity of molecular aggregation, but
diiefly to the presence df certain mineral salts which are always associated with the
adabie yazietj. In fiict, albumin does not occur in the amm^l body in the free
states but in the form of an alkaline albuminate ; white of egg, serum, and all liquids
whidi eontain albumin, leave, when incinerated, an ash chiefly consisting of alkaline
evbonate. Insoluble albumin does not appear to exist in the living animal orgaiiism,
unless indeed, fibrin may be regarded as coagulated albumin, which is by no means
imptobabie, inasmuch as there is no exact method of distinguishing between the two.
^PrepttraUofU — Albumin may be prepared either from white of egg, or from blood-
senna. White of e^ consists of transparent thin-walled cellules, enclosing an alkaline
aofaition of albuminate of sodium. On beating it up with water, the cellular sub-
stanoe separates in pellideSr while the albuminate of sodium remains in solution,
together with chloride of sodium and phosphate of calcium. To remove these mineral
aabstanoea, the liquid, after being filtered from the cellular substance, is mixed with
a small qna&titj of snbacetate of lead, which produces an abundant precipitate (an
excess of the lead-salt would redissolve it). Tiie mass, after being washed, is stirred
up with water to the eonsistence of a paste, and carbonic acid gas is passed through
the liquid. The albuminate of lead is thereby decomposed, carlwnate of lead remains
sDspended in the liquid, and the albumin in the free state remains dissolved. The
sedation is filtered through paper previously washed with dilute acid, and, as it still
retains traces of lead, it is treated with a few drops of aqueous hydrosulphuric acid, and
caatioosly heated to 60^, tiU it begins to show turbidity ; the first fiocks of albumin
thus precipitated carry down the whole of the sulphide of lead. When the liquid
which after filtration is perfectly colourless, is evaporated in large capsules at 40<^,
a residue is obtained consisting of pure soluble albumin (Wurtz, Ann. Ch. Phys.
[3] xii. 27)* The same method applied to the albumin of blood-serum does not yield
a pure prodaet*

To obtain pure albumin in the coagulated state, white of egg, diluted with an equal
balk of water, filtered, and reduced to its original vdume by evaporation at 40^, is
mixed with a strong solution of potash, whereby it is soon converted into a translu-
eent, yellowish elastic mass. This is divided into small portions and exhausted with
eold water as long as the water removes any alkaU, the whole being kept as much
as possible fitmi eontact with the air. It is then dissolved in water or boiling alcohol,
ana the solution is precipitated by acetic or phosphoric acid. The precipitate, after
washing leaves no appreciable residue when mcinerated. (Lieberkiihn.)

Pnperties, — Soluble albumin, dried in the air, forms a pale yellowish, Iranslucent
mass, easily triturated and reduced to a white powder* The specific gravity of the
albfirain of the hen's egg, from which the salts nad not been removed, was found by
C. Schmidt (Ann* Ch« Pharm. xi. 166-167), to be 1-3144, and after calculating
for the elimination of the salts, the density of pure albumin was found to be 1*2617.
It beeomes electric by friction, and is tasteless, inodorous and neutral to vegetable
eolourB. It swells in water, assuming a gelatinous appearance ; it does not dissolve
freely in pure water, but very readily in water containing any alkaline salt. After
being dried in vacuo, or at a temperature below 60^, it may be heated to 100^ with-
out passing into the insoluble modification. Soluble albumin dried at 60^ loses 4 p. a
water at 140°, remaining, however, soluble in water.

The aqueous solution of albumin deviates the plane polarisation of a ray of light
to ibe left. It becomes opaline at 60°, begins to deposit the albumen at 61° to 63°,

Vol. L F

66 ALBUMIN.

and at a temperature a little hi^er the whole ooagnlates in a maM. When Ttay
dilate, it becomes tnrbid without coagulating ; but if the liquid be then concentrated
bj evaporation, it depoeita the albumin in p«llicleB or flocks.

Coagulated albumin is white, opaque, efastic, and reddens litmua (Hruachaueri
Ann. Ch. FharnL zItL 348). When dried, it assumes a yellow colour, and becomes
brittle and translucent like horn. When immersed in water, after dicing, it gra-
dually absorbs about five times its weight of the liquid, and resumes its primitire
consistence.

When coagulated albumin is boiled in toater for about 60 hour% it gradually dis-
appears, being transformed into a subetance soluble in water, and consisting^ ac-
cording to Hulder and Baumhauer (J. pr. Chejn. xx* 346 ; xxzl 295), of triaxide
of protein, C"H"NK)» (C - 6098 p. c. ; H - 6-69 ; O and S - 601 ; N « 27-32).
Coagulated albumin, heated to 160° with a small quantity of water in a sealed tube,
graoually forms a limpid solution, which has no longer the property of coagulating by
heat. (L. Gmelin.)

Albumin is insoluble in alcohol and in ether. Strong alcohol added in lazce ezcera,
precipitates albumin fi?om its aqueous solution in the same state as when it is
coagulated by heat; but the precipitate produced by a small quantity of weak
alcohol redissolyes completely in water. Wnen alcohol is added to a somewhat dilute
solution of albumin, so as to render it slightly opaline, the liquid after a while,
solidifies in a jelly, which, howerer, is a^un liquefied by heat. Coagulated serum,
or white of egg, may be made to dissolye in aloonol by the addition of a little aUcalL
(Scherer.)

Ether shaken up with a solution of albumin ooagnlates but a small portion of it ;
if^ however, the albuminous solution is concentrated, it thickens so much as to appear
coagulated. Albumin is not acted upon by oils either fixed or volatile.

Nearly all acids precipitate albumin m>m its solutions. Nitric add precipitates
it with peculiar facility, and may therefore be used as a test of the presence of
soluble sibumin. Strong hydrochloric acid aided by heat dissolves coagulated albu-
min, forming a blue or violet solution, which turns brown when boiled in an open
vessel, and according to Bopp (Ann. Ch. Pharm. Ixix. 30) yields chloride of am-
monium, leucine, tyrosine, and oUier products of unknown composition. With aqua
regia^ albumin yields both chlorinated and nitro-compounds.

Strong sitlphuric acid coagulates albumin by the heat which is evolved when the
two liquids come in contact Dilute sulphuric add precipitates albumin after some
time only, not however combining with it» as the add may be completely removed
from the precipitate by washing.

Tribasie phosphoric acid, acetic, tartaric, and most other orsanic acids do not fbnn
precipitates in moderately concentrated solutions, of albumin ; but when either of these
acids is added in excess to a highly concentrated solution of serum or white of e^, the
liquid solidUies in the cold to a jelly which liquefies like gelatin when heat^ and
again forms a'gelatinous mass on cooling. The aqueous solution of this jellv remains
perfectly tran^arent when boiled, but it is precipitated by a neutral salt of either of
the alkali-metals. (Lieberkiihn.)

When a small quantity of acetic acid is added to white of effg or serum, so as just
to saturate the alkali, and the liquid is then largely dilutedwith water, flocks of
albumin are deposited after awhile. If the supernatant liquid be then decanted,
and the precipitate treated with a small quantity of solution of nitre or common
salt, it immediately dissolves, and the solution is coagulated by boiling. (Scherer.)

Serum or white of egg mixed with a certain quantity of common salt or other
salt of an alkali-metal, forms a liquid precipitable by phosphoric, acetic, tartaric,
oxalic, lactic add, &c. Conversely, a solution of albumin Tor other albuminoidal sub-
stance) in acetic acid is predpitated by the salts of the alkali-metals. The predpi-
tation is greatly facilitated bv heat, and Likewise takes place with ^;reater fiunbty
as the proportion of salt added is greater. The predpitate dissolves in pure water,
with greater fadlity in proportion as less heat has been applied in piodudng it;
the s(9ution is not coagulated by heat. It is soluble also in acetic acid, phospnorie
acid, and even in alcohol, provided it has not been altered by desiccation, or by
contact with the air. The aqueous solution is predpitated by certain salts, ferro-
cyanide of potassium, for example.

Dried soluble albumin suspended in acetic, tartaric, or dtrie acid, swells up and is
converted into coagulated albuinin, which may be completely freed from acid by
washing. Acetic, tartaric, and tribasie phosphoric add dissolve coagulated albumin
when heated with it. Arsenious acid does not combine with albumin. Chlorine and
bromine precipitate albumin.

Alkalis do not in general predpitate albumin from its solutions; but a strong
rolution of potash added in considerable quantity to a solution of albumin, forms a

ALBUMIN. 67

gebtinoiia maa of allnimizuite of potassiiim. Dilatd solntioiui of potash and soda
mix vith JtlKntnin in all proportions, and on boiling the liqnid, an alkaline snlphide is
fiomed. When albumin is heated with hydrate of potassium melted in its water of
ojstallisation, the water being renewed as it evaporates, ammonia and hydrogen
an erolred, leucine and lyrosine are produced, together with oxalate, butyrate
Talerate, &c of potassium. Alkaline carSonates added to a solution of albumin preyent
its coagulation by heat. Coagulated albumin digested at a gentle heat wititi nenla^
carbonate or acid carbonate of sodium, displaces Qie carbonic add, and forms with the
alkali a eompoond, which, after washing, is perfectly neutral to test paper, but leayes
when incinerated a considerable quantity* of alkaline carbonate.

Albomin sabjected to dry SstillaUtm yields water, carbonate of ammonium,
hjdroffolphate of ammonium, Tolatile alkalis of undeterxnined composition, empyreu-
Datic oils, ^Icc Coagulated albumin putrifies when left in contact with water, yielding
Tslerie and bntTric acids, a crystalline body having a penetrating odour, an oily
add, and a anbetance which dissolres in hydrochloric add, producing a liquid of
beautiiul yiolet colour and jielding tyrosine, together with other products (Bopp, Ann.
Ch. Phaim. Ixix. 30). The oxygen of the air has no action on serum or white of egg.
Seoenfly extracted serum left for a fortnight in contact with oxygen in a tul^
ftr"^*^C over mercury absorbs but a yeiy small quantity of the gas, and does not
IbflB carbonic acid.

Albumin distilled with a mixture of peroxide of manganese and stUphurie acid
jieldB acetic, propionic, butyric, and benzoic aldehydes, t<^ether with formic, acetic,
MbfriCy Talenc, and benzoic adds, and probably also propionic and caproic acids.
Keuly the same products are obtained by distilling albumin with eulphurio acid and
add ekromate of potassium, this mixture yielding in fact, hydrocyanic add, a heavy oil
having the odour of cinnamon, cyanide of tetz^l (valeronitrile), also benzoic, acetic
and TO.tyric adds, with smaQ quantities of formic, caproic and propionic adds, and of
benzoic and propionic aldehydes (Guckelberger, Ann. Ch. Pharm. Ixiv. 39). Al-
bomin does not decompose oxygenated water,

Cowiposition of Mbumin, — Albumin obtained from various animal fluids exhibits
the same composition, as shown by the following analyses : —

From White qfEgg.

/ * ,

Duniu

Mulder. Sch^rar. and Cahours. Rilling. Wurtz. LleberkOhn.

Caibon . 63*4 . . 54*3 . . 63*4 . . 63^4 . . 629 . . 63-3

Hydzogen . 7*0 . . 7*1 . , 7*1 . . 7*0 . . 7*2 . . 71

Nrtiogen . 16-7 - . 15'9 . . 16-8 16-6 . . 16-7

•• •. •• .. .. MA X

1-7 to 1*8 1-8

8al

Wurtz's analyais was made with soluble, the rest with coagulated albumin. Mulder
sopposes that albumin contains also 0*4 per cent, phosphorus. Most of the preparations
with which the above analyses were made, contuned small quantities of phosphorus
in the fizEm of phosphate of caldum.

Caiton
Hydrogen
Kitxogen
Oxysen •
Sulfur .

JPhmt Koodsermm,

r " ' ' All ^

Dumat and Cahoun. Mulder. Rtiling: Scberer.

68*3

7-1
16-7

6Z'6 . . 63-4 . , 63-1
7-3 . . '71 . . 70
16-8 . . 16-6 . . ..

1*3 . . 1-3

64-5
70
16-7

Mu]dar Biqyposes that blood-albumin contains also 0*3 per cent, phosphorus. Billing
foond the amount of sulphur in eight analyses to vary fix>m 1*29 to 1'39 per cent

Sdierer. Weideabtuch. Baumhauer.

/ -• »

a b e d e

Carbon . 54'2 . . 641 « . 540 . • 53'3 . • 54*3
Hydrogen . 71 . . 72 . . 7*0 . . 70 . . 7*1
Nitrogen . 16-5 . . 16*8 . . 15*8 . . 16'7 . . 15*8

Oxyeen

So^hiir • • «..• •• •

4 from a hydrocele ; b from a congestion-abscess ; e from pus ; d from flesh of
poultry ; e from the flesh of fish.

From thme and other analyses, liebig deduces the formula G^'W^^S'O^ : Mulder,
CrH»«T««SO": laeberkiihn, C«fl'»>N"SO« Each of these formulro gives numbers

F 2

^ I

68 ALBUMIN.

Agreeing nearly with the analytical tesulta. Mulder regards albondn as a eompoond
of (hypothetical) protein vith (hypothetical) aulphamide, tiz. :

Protein. Sulphamide.

Liebigf 8 formula is intended merely to express in a simple form certain relations
between albumin and other animal substaiices. laeberkuhn, on the other hand,
regards his formula as actoalLy expressing the composition of the molecule of albumin
as it exists in the metallic albuminates {q, v.)

According to Lebonte and Goumoens (J. Pharm. [3] xxiy. 17) albumin is not
a pure proximate element, but a mixture of two bodies, one of which is insoluble in
glacial acetic acid, while the other dissolves in that acid and is precipitated therefrom
by potash.

The properties of albimiin -vary in some degree with the source from which it is
derived. The differences may in some cases be attributed to the presence of different
mineral substances ; but in others they are of such a nature as rather to point to
the existence of different modifications of albumin. Thus, Fr^my and Yalen-
ciennes have found (Ann. Ch. Phys. [3] L 138) that the albumin of the eggs of
certain tribes of birds of exhibits peculiar modifications. That from the eggs of
different species of gallinaceous birds always exhibits the characters above described ;
but the eggs of swinmiing and wading birds yield an albumin which, when diluted
with 3 measures of water, is not coagulated by heat, but is precipitated by nitric acid ;
and the albumin from the eggs of predaceous bird^, and of some kinds of perchio^
and climbing birds is neither coagulated by heat nor precipitated by nitric ad£
The composition was, however, found to be the same in all cases.

Blood-albumin exhibits the same reactions as that from white of egg, excepting that
the latter when boiled gives up part of its sulphur in the form of sulphuretted
hydrogen, which blood-ubumin does not; nevertheless coagulated white of egg
appears to contain more sulphur than blood-albumin.

Paralbumin, — Scherer found in a liquid obtained from a case of ovarian dropsy,
a substance resembling albumin, but differing from it in not beins completely preci-
pitated by ebullition, even after addition of acetic acid, and in dissolving in water
after being precipitated by alcohol. MetaUmmin is the name given by the same
chemist to another supposed modification of albumin, likewise obtained frrom a pa-
thological fluid, which . exhibited similar peculiarities to the preo^ling, and was
fruther distinguished by giving no precipitate with hydrochloric acid, or with ferro-
cyanide of potassium after acidulation with acetic add.

Other substances more or less resembling albumin are: ghhtdin or erystaUin
existing in blood-globules and in the crystalline lens of the eye ; JuBmatocrygtaUin^ a
crystalline body obtained from blood, and vitdUUf ftTiating in the yolk of eggs (see
these substances).

Quantitatiife Estimation of Albumin, — The best mode of precipitating albumin
from alkaline liquids (serum, for example), for (quantitative estimation, is to neutralise
or slightiy acidulate the liquid with acetic acid, and then coagulate the albumin by
boiUng. The precipitate thus obtained is flocculent and may be easilv collected on
a filter and washe(^.the liquid passing through perfectiy clear, whereas if the albumin
be coagulated by heat alone, it is veiy apt to dog the filter. Another reason for
using &e acetic add is, that mere boiling does not predpitate the albumin completely
from alkaline solutions. The precipitated albumin, after being thoroughly washedf,
may be dried in vacuo over sulpnuric acid or in a current of warm air.

Uses of Albumin. — Albumin is much used for darifying vinous and syrupy liquids,
inasmuch as, when boiled with them, it coagulates, aiid takes hold of the colouring
matter and other impurities, thereby removing them, and canying them to the bottom
or to the surface of the liquid, according to its density. In cookery, white of esg
is employed for this purpose, but in large operations, such as sugar-refining, the
serum of blood is used. Albumin is applied to a considerable extent for fixing
colours in calico-printing ; it is also used in photography. Its property of forming aharS
compound with lime renders it very us^Ful for making cement for laboratory pur-
poses and for mending broken earthenware. A paste made of white of egg and
slaked lime, acquires after a while the hardness of stone.

Albuionatbs. (Lassaig^e, Ann. Ch.Phys. [3]lxiv. 90; Lieberkilhn, J. Pharm.
[3] xxxiii 398 ; Lehmann, Physiol. Chem. i. 382; Gerh. iv. 447.) — Albumin is a
weiEik acid, and apparentiy dibasic Its compounds with the alkalis are soluble and
are obtained directly by treating albumin witn caustic alkalis or alkaline carbonates.
The other albuminates are insoluble and are obtained by predpitation.

AJUnminaU of Barium, CH^^^BaN^SO" + H*0 (?) — A solution of albuminata

ALBUMIK 69

of pfftinrinin in dilute alcohol fomui with baziiimHnlts, a precuutate which dries
«p to a white powder, insohible in water, alcohol and ether, white of egg mixed
with eauBtie hazTta^ strontia or lime^ fozma an inaolable compound, whichbecomea
Ttrj hard whea drr.

MbmminaU of Copper, C**Hi»Ca'N»SO« -i- HH) (?) — Obtained in like manner
Ibnna when diy, a ^reen, brittle mass, insoluble in water and alcohoL Acids deoo-
loriae^ bnt do not dusolTe it (Lieberknhn). Aoooidin^ to Laasaigne, double albu-
miuatfm of eoj^wr with potassium, or barium, or calcium, may be obtained by
heatiog hydrate of copper with solution of albumin and solution of potash, baiyta or
lime, lliere is also an albuminate of copper and magnesium which is insoluble
and has a lilae eolour.

ASbmmbuUe of Lead is a white insoluble salt, obtained by mixing the solution of
■iTytrntii and snbaoetate of lead; it is soluble in excess of the lead-salt, and is decom-
posed by all adds.

Mtreurie jUbwminate is a white substance obtaioied by precipitating corrosive
sublimate with albuminate of sodium (white of egg). It is insoluble in pure water,
bat soluble in saline liquids ; for this reason, when white of egg is used as an antidote
in cases of poisoning br coRosiTe sublimate, endeaTours should always be made
to prodnoe Tomiting; ouierwise a portion of the mercuric albuminate may remain
diasdlTed ia the gastric juice, which contains chkride of sodium.

JUmmintUe of Fotassium, C«H»'«?N»SO« + H«0. — Prepared by mixing a con-
oentrated solution of white of egg with strong potash-ley, and washing the result
log gelatinous mass with cold water, as long as any alkali dissolves out^ then dissolving
the residae in boiling alcohol, and precipitating by ether. After diying, it is no longer
eohible in boiUne alcohol or in water. The aqueous solution is not coagulated by
boiling or by addition of aloohoL With a smaU quantity of acetic, tartaric, citric
or plusphorie add, it yields an abundant white precipitate easily soluble in excess of
aeuL These cfaaraetess axe the same as those of casein ; henoe^ Gkiriiardt considers
it probable that casein ma^ be really albuminate of potaasiunL.

AlbmfmtmaU of Sodium is contained in blood-serom and in white of egg, together
with chloride of sodiom and phosphate of calcium. Seram and white of egg have
a slight alkaline reaction,, are more soluble in water than pure albumin, and when
bailed, coagulate in a gelatinous mass, not in flakes. After boiling, the filtered liquid
is mors a&aline than before, and still contains albinyfiate of sodium, whereas the
eoagufaim is f^ fiom alkali. Hence^ Gerhardt thinks it probable that serum
and white of egg contain an acid albominate. of sodium, C^Hii^NaN^^O**,
which is decomposed Inr heat into the neutral albuminate^ and free albumin which
separatee from the liquid. This view is, moreover, in accordance with the composition
of dried white of egg, which, according to Lehmann^s analysis, contains 1*6 per cent.
of soda, the finmula CP*H"»NaN*^90«" + HK) requiring 1*8 per cent White of egg
or serum treated with strong caustic soda, yields a eelatinous mass nearly insoluble
in eold water, and doselv resembling the compouna produced under the same dr-
cnmstanoobypotash. This gelatinous salt appears to be the neutral aHmminate of
ModhtM, CH'^fNa'N'^BO'' + SPO. It contains, according to Lehmann, 3*14 per cent.
soda (by caleulation 8*7).

AHmmnuOe of SUver, C»BP>*Ag»N»«SO« + HH) (?) — Obtained by precipitatioa
White, floccnlent, blackens when exposed to light.

Ai^mmifUMte of Ztne, C«H"«Zn«N»feO" + H*0 (?>— White powder insoluble in water,
aloobol, and ether.

AXSmnar, VBOarABSa. (Gerh. iv. 444; Handw. d. Chem 2*« Aufl. ii.
147.) — Most v^etable juices contain a substance which appears to be identical in
composition and properties with the albumin of blood or of white of egg. The
same compound appears also to exist in the solid form in certain parts of plants,
e^wdally in the seed. Vegetable juices containing albumin deposit it, when heated
to 66^ or 70^, in flocks, which are often coloured greenish by diforophyll, and contain
&tty and waxy substances mechanically enclosed. To remove these matters, the
ooagnfaim must be washed, first with water, then with boiling alcohol and with ether.

^bumin is especially abundant in the juice of carrots, turnips, cabbages, and
the green stems of peas, but it is more easily prepared from potatoes, by cutting
them into slices, covering them with very dilute sulphuric add (of 2 p.e.), leaving the
liquid to itself for 24 hoars, then adding fresh potatoes, and repeating the same
opcfation onoe more, afterwards neutralimng the solution with potash, and boiling.
A considerable quantity of albomin is then deposited in thick white fiocks.

Wheat-flour also contains a condderable quantity of albumin, which may be ex*
tneted widi cold water. For this porpose, the water which runs off in washing the
paste €fi wheat-flour for the preparation of gluten (q, «.) is left at rest till the starch

F 3

70 ALBUMINOIDS.

is completely deposited; the dear liquid is then heated to the boiling point, where-
upon it depoeits a small qnantily of albnmin ; on eTapoiating the solution a laiger quan-
tity is obtained.

Oleaginous seeds likewise contain albumin, which may be extracted by beatins
the seeds with water into an emulsion, extracting the &t by agitation with ether, and
the albumin by boiling.

When sweet almonds which have been fi?eed from their euTelopes are reduced
to a pulp by rasping, and the pulp is digested for a few minutes in boiling water,
the sugar, g^um, and the greater part of the legumin contained in the almonds enter
into s^ution; and on depriving the residue of fatty matter by means of ether,
nothing is left but coagulated albumin, exhibiting the same characteni as coagulated
white of egg.

b e

Carbon . 640 . 637 . 61*9 to 620 . 63-1 . 62*0

Hydrogen . 7*8 . 7*1 . 6*9 . 7*0 . 7-2 . 68

Nitrogen . 16*8 . 16-7 . 18-4 . . . . . . .

Oxygen

Sulphur 0-97 . 079 . 1-0 . 0*77

a, albumin from rye,analysed by Jones (Ann. Ch. Pharm. xl. 66) ; b, from wheat-
flour, by Dumas and Oahours (Ann. Gh. Phys. [3] tL 809); r, from wheat-flour
by Boussingault (ibid. [2] Ldli. 226); d, from potatoes byBiiling (Ann. Ch.
Pharm. Mil. 306) ; e, from peas b^ Billing; /, ^, fix>m rye, by Mulder.

Vegetable albumin is distinguished fh)m legumin (yegetable casein) by being
coagulated by heat, and not precipitated by acetic add. It exhibits the same

actions as animal albumin with adds, allcalis, tannin, chloride of mercuiT, &c. Tho
mode of its occurrence differs, however, remarkably from that of animal albumin in
this respect, that it is always foxmd in plants in neutral or add liquids, whereas animal
albumin exists only in alkaline liquids (p. 26).

The albumin of sweet almonds is remarkable for the fadlity with which it decom-
poses, and by its property of acting as a ferment, and determining the metamorphosis
of amygdaliii, salidn, and other organic bodies. This altered albumin is distingnished
by the terms emidsian and synapittae {q, v.)

The myrosin of mustard-seeds likewise resembles vegetable albumin. Lastly, the
diastase of germinated barley, beer-yeastf and totne-l^ are likewise albuminoidal
substances in a state of alteration.

Oonin. (Handw. d. Ohem. 2*« Aufl. i. 404.) — The name given bj
Gouerbe to the substance of the cells which enclose the white of birds' eggs. It is
obtained by exposing white of egg for a month to temperature between 0^ and— 8^, in
the form of a white filmy substance, which when dried is whiter translucent in thin
laminse and easily friable. It does not contain nitrogen, and consequently does not
evolve ammonia when heated. It is insoluble in water, whether hot or cold, but swells
up in hot water, forming a gummy mass. It is not acted upon by alcohol, ether, or
acetic acid. Nitric and sulphuric acids decompose it. It dissolves in hydrochloric
acid, and on adding water to the solution, a white powder is predpitated. It dis-
solves in caustic potash, forming a solution which is rendered turbid by adds, but not
predpitated.

A&BVBSIirozsS. Protein-compounds, JSlutbilder. (Gerh. iv. 430; Handw.
d. Chem. 2** Aufl. ii. 120.) — This term is applied to a <uass of compounds which
play an important part in the functions of animal and vegetable life. Three of them,
alfmmin, casein, 9XidL fibrin are distingnished by well-marked characters.

Fibrin separates spontaneously in the solid form from blood, soon after its removal
from the living body ; albumin is contained in the serum or more liquid portion of
the blood, and separates fh>m it as a coagulum on the application of heat; and
casein is contained in milk, ttom. which it may be separated, not by heat, but by the
addition of an acid. The same substances are found in plants, viz. fibrin, in the grain
of wheat and other cereal plants ; albumin in most vegetable juices, and casern (or
legumin) in the seeds of the pea^ bean and other leguminous plants.

The other bodies of this dass are less distinctly characterised ; indeed, most of
them appear to be mere modifications of the one or other three above-mentioned:
thus, synionin, the essential constituent of the muscular fibre, dosely resembles
blood-fibrin ; viteUin, a substance occurring in the yolk of eggs, is scarcdy distin-
guishable from albumin; and globulin and hamatacri/stallin, two substances con-
tained in the blood, resemble albumin in the property of coagulating by heat.

Moreover, albumin, fibrin, and casein, though clearly distinguished from one
another by the different conditions under which they pass from the liquid to the

ALBUMINOIDS. 71

solid stslOy nereiiheleflB posseBS many chaiacten in eommon. Tliej all disBolTO in
oostie potash or aoda^ and when boiled with thoae alkalis, yield solutions from which
leids precipitate theja in a more or less altered state, and at the some time eliminate
hjpdrGSQlphniic add. When subjected to dij distillation, they all give off ammonia
(or oompoond ammonias). Th^ all decompose and putrefy with great &cility when ex-
posed to moist air» and in that form are yeiy actiye as fermenia ; thus, yeast, wine-less,
jitrfjMw, ice^ are merely albnminoidal substances in a peculiar state of dedomposition.

All albununcids treated with oxidising agents, such as mixtures of peroxide of
flumgaDCse or acid chromate of potassium and sulphuric acid, yield the same products,
TUL aeids and aldehydes of the acetic and benzoic series (see Albdvin, p. 67). — Albu-
mindds dissolre in Tery strong hydrochloric acid, forming a solution which is yellow
if kept ftom contact with the air, but assumes a fine blue or violet colour on exposure
to the air. — ^A solution of mercury in an equal weight of nitric acid imparts to these
bodies a Teiy deep red colour, this test serving to detect the presence of 1 part
of albumin in 100,000 ports of water.

AD the albuminoids exhibit the same or nearly the same constitution. In the
firing oiganism, albumin, fibrin, and casein are constantly being converted one into
the other. The casein of milk supplies the material for the formation of albumin
and fibrin; and conversely, albumin and fibrin are conyerted into casein. Indeed,
the analyses of different bodies of the class do not differ from one another more than
analyses of the same body from different sources or by dififerent experimenters. They
eontain 50 to 54 p. c. carbon, about 7 p. c. hydrogen, 15 to 17 p. c nitrogen, about 25 p. c.
ozjgen, and from 0*9 to 1*8 sulphur. Accoiding to some analyses, however, fibrin
oootains rather less carbon and more ziitrogen uian albumin. Albumin and fibrin
have been supposed by some chemists to contain also a small quantity of phosphorus
88 an organic constituent, but its existence is not well established. Most albuminoids
are associated with small quantities of mineral substances, including phosphate of cal-
rioBi, which cannot be separated from the organic matter by acids.

This great similarity of composition and properties exhibited by these bodies has
led to various views of the relation between them. Mulder supposed that all the
ilbuminoids contain the same organic group, G^H^^O*, which he cabled, prottin^
combined with different quantities of sulpnur and phosphorus, and that the con-
Tcraian of one of these bodies into the other depends upon the assumption or elimina-
tion of nnall quantities of one or both of those elements (see Pbotsin). Mulder
also stated, that when an albuminoid is treated with caustic alkali, the sulphur and
TtboK^tufroB are removed and the protein remains. The researches of other chemists
hsve shown, however, that this view is untenable. Neither of the albuminoids
contains phosphorus, and the proportion of sulphur appears to be the same in them
all: at ail events, fibrin and egg-albumin, which perhaps exhibit the greatest dif-
ference of physical and chemidal properties, do not differ perceptibly in amount of
snlphur. Moreover, the sulphur of albuminoids cannot be completely extracted by the
action of alkalis, so that the existence of the so-called protein is merely hypothetical.

Gcriiazdt was of (pinion that all the albuminoids are identical, not only in com-
posxtioD, bat in chemical constitution, and that they differ from one another only
m moleenlar aznuigemezit, and by the nature of the mineral substances with whidi
they are associated; in &ct, that they contain a common proximate element which,
Hke many other oiganic compounds, is capable of existing in a soluble and in an
insoluble modification. Designating this common element by the name albumin, he sup-
posed that white of egg and serum consist of add albuminate of sodium (p. 99), which is
separated by heat into free albumin and neutral albuminate of sodium, the latt^ remain-
ing disBolyed ; that casein, which is soluble and non-coagulated by heat^ consists of
nntral albmninate of potassium, from which the organic compound may be precipitated
by neutralising the alkali with an add ; and that fibrin is albumin in the insoluble state,
more or leas mixed witii earthy phosphates. This view is in accordance with the &ct
that fifarin and caadn may be oissolyed in neutral potassium-salts (better with addi-
tion of a little canstic alkali), forming a liquid which coagulates by heat, and deflects the
plane of polarisation of a luminous ray to the left, like albumin ; and that fibrin and
albumin, diasolyed in a certain quantity of caustic alkali, exhibit the characters of
sdbble casein. Nevertheless, it is possible to obtain the albuminoids in some cases
whol^, in othen yezy nearly, free from mineral matters, and neyertheless exhibiting
their distingnishing characteristics. Moreoyer, it is certain that all these bodies
contain tiie same proportions of carbon, nitrogen, and sulphur.

Strecker (Huidw. d. ChenL 2** Aufl. ii. 124) eappoaee the albuminoids to be
eoDoposed of a great number of radides (a supposition m accordance with the variety
of their prodncts of decomposition) ; that the greater number of these radides are the
aaaia in aU — hence their great similarity, — but that each contains one or more
sneh radiclea pecnliar to itsdt Thus, when casein is oonyerted in the animal body

F 4

72 ALCOHOL.

into albumin and fibrin, it mfty take the radides required for that transformatioa
from the other constituents of the milk, viz. the fat and the sugar. (See Aiadkin,
BiiOOD, Cassin, Cbystaluhb, Fibsih; Globulin, Hjematocbtstaliik, LBOUimr,
Milk, Yitbllin.)

AXMUWUMOWMb This term is applied by Bouchardat to a product of the decom-
position of animal fibrin by Tery dilute hydrochloric acid (see Fibbik), and by Mialhe,
to a peculiar substance into which he supposes albumin to be oonyerted by the action
of the gastric juice before it is assimilated.

A&CAXBASAfl> Very porous yessels of slightly burnt clay used in hot climateB
for cooling water and other liquids. The liquid oozes through the pores and stands
on the outside of the yessel in a sozt of dew, which rapidly evaporatee^ especially if
the vessel is exposed to a current of air, and thereby cools the Uquid.

A&CBSBVZlb&A VmbOASZS. 100 pts. of the fresh plant contain, acoarding
to Sprengel : 76*0 pts. water, 10*3 pts. extractable by water, and 7'8 by dilute potash-
ley; 5*6 woody fibre and 1'66 ash free from carbonic acid. The ash contained in
100 pts. ; 30*6 potash, 2*4 soda, 33 '6 lime, 4*9 magnesia, 0*9 alumina, 14*4 silica,
4*4 sulphuric anhydride, 5*4 phosphone anhydride, B-6 chlonne, and traces of the
oxides of iron and manganese.

AX«COBO&. C»H*0 = C*H».H:.0 [or C*H*0' « C^B^O.HO.]. This compound,
which is the spirituous or intoxicating principle of wine, beer, and other fermented
liquors, may be regarded as the hydrate or hydrated oxide of ethyl, or sjb a molecule of
water, HHO, in which half the hydrogen is replaced by the radicle ethyl, CH*. It has also
been regarded as a compound of ethylene and water, CH'.H'O.

History. — Intoxicating drinks produced by fermentation of vegetable juices contain-
ing sugar, have been known from the earliest times ; but it was not till the twelfth
century that the method of obtaining pure spirit of wine or hydrated alcohol from
these Uquids by distillation, was discovered by Abucasis ; and the dehydration of this
liquid was first partially effected by means of carbonate of potassium by Baimond
Lullins in the thirteenth century. The mode of obtaining perroctly anhydrous alcohol
was afterwards discovered by lK>witz.

Formation. — I. By the decomposition of glucose (grape-sugar) under the influence
of ferments, that is to say, of nitrogenous organic substances, such as ^east, which are
themselves undergoing decomposition. The sugar is then resolved mto alcohol and
carbonic anhydride :

(XB«0« - 2C»H*0 + 2C0«.

Other kinds of sugar, cane-sugar for example, as well as starch, woody fibre and
other vegetable substances, also yield alcohol under the influence of ferments, but they
are first converted into glucose.

2. From ethylene or defiant gas, by addition of the elements of water :

C«H« + HK) = C«H«0.

Olefiant gas briskly agitated for a long time with strong sulphuric acid, is absorbed,
and on diluting the uquid with water and distilling, alcohol passes over. This mode
of formation, first observed byHennel (Phil. Trans. 1826, p. 240), has lately been con-
firmed and fully examined by Berthelot(Ann. Ch. Phys. [3] xliii. 885). As olefiant
gas can be obtained from inoi^anic materials, it follows that alcohol may be produced
without the agency of living organisms.

Preparation. 1. 0/ HydraUd or Aqueous Alcohol. — ^When wine and other liquids
which have undersone the vinous fermentation are distilled, alcohol passes over t(^ther
with a considerable quantity of water ; and by subjecting the product to repeated dis-
tillations, spirit is obtained continually richer in alcohol, because the alcohol, being
more volatile than the water, passes over in larger quantity than the latter. But it is
not possible to remove the whole of the water by simple distillation. The residue of
the custiUation, if continued long enough, is notMng but water containing small quan-
tities of acetic acid (produced by oxidation of the sdcohol) and fiisel oil. Portions of
these impurities also pass into the rectified spirit. The greater part of the acetic acid
however, and a considerable portion of the fusel oil are left in the residues of the
several distillations. The last portion of the acid is easily removed by distillation
over a small quantity of carbonate of potassium or wood-ashes : and the fasel oil,
which adheres more obstinately, and imparts a very unpleasant odour to the spirit, is
best removed by adding to the spirit about 0*7 of its weight of coarsely powdered
charcoal, leaving the mixture to stand for several days, and stirring it repeatedly, then
decanting and distilling. Bone-black or blood-charcoal may also he usea.

2. Of Anhydrous or Absolute Alcohol. — ^Alcohol cannot be completely dehydrated by '
distillation, because, at the boiling-point of pure alcohol (78^ G.^, the vapour of water
possesses a considerable tension. The most highly rectified spirit obtained by fhiei

ALCOHOL. 73

dislalbitioA, BtQl letains about 9 per cent, of water. The last portioiiB of water
niHt be KSioTed by the agency of some substance which has a poweirol attraction for
it Caibooate of potassimn, chloride of calcinm, and qiiick lime, are the sabstanoes
Bost commonh' used for ihis poipoee, more rarely acetate of potassium, sulphate of
copper, and other salts.

0. Sy Carbonate of Ii>ta$sium. — ^Highly rectified spirit is shaken up with ignited
esibonate of potassium, which forms a watery or pasty layer at the bottom* The
akohd, whose density is thereby lowered to 0'815, is poiLted off into a t^iMtiTli'ng yessel
containing tvioe the quantity of palyerised and recently ignited carbonate of potassium,
kft to stand for 24 hours, and then two-thirds of it are diatilled off (Lo wi tz). This
method does not however remove the last minute portions of water. — b. A more com-
pfetd dehydration is effected b^ chloride of caicium. The salt fused or dehydrated by
a beat of 400^ C. ia added in tiuck lumps to twice its weight of spirit containing 90 per
cent of real alcohol ; and the mixture left for some days in a closed vessel and occa-
mooaJlj shaken up^ after which it is distilled in a retort over a fresh quantity of fused
diiorioB dT ealduuL The retort is heated in a sand or oil bath with its neck directed
upwwpda to prevent the contents &om spirting over. When the quantity of alcohol
is laige^ a second treatment with chloride of calcium is necessaiy to effect complete
dehjthation.

c By QmetltTne, — ^A retort is two-thirds filled with small pieces of quick lime, and a
quantity of 90 per cent, spirit poured in sufficient to nearly cover the lime. The lime
aooD slakes and becomes heated ; the miztoze is left to digest for some hours ; and the
anbydnras alcohol is then distilled off in the water^bath. The distillation must be care-
inDy conducted, otherwise the distillate will be contaminated with lime. Alcohol con-
taining fusel oil acquires a very unpleasant odour when treated with lime. This is by
hr the easiest method of obtaining absolute alcohoL

d. When aqueous alcohol is enclosed in a bladder, and exposed to warm air, the
water gradnalh' percolates through the bladder and evaporates, and absolute alcohol is
left inside. (Sdrnmerins.)

Akohol may be regarded as anhydrous if sulphate of copper previously burnt white
does not acquire any blue colour when immersed in the aJconol m a close vessel (Cas-
soria), or if it forms a perfectly deaf nuxtnre with benzol (Gorgeu). It is doubtful
however whether either of these tests will indicate the presence of a veiy minute
quantity of water.

/Vopertusf . — ^Alcohol is a transparent, colourless, veiy mobile liquid, having a strong
lefraeting power. Its specific gravity, according to ICopp (Pogg. Ann. Ixxii. 1), is
0-792 at 20^ ; or 0-7989 at 16-5^ or 0-8095 at 0^. If its volume at 0° C. be taken for
unity, the volume at any temperature i9 is given by the formula:

tr = 1 + 0-00104139i + 00000007836^ + 0000000017618<«.

and therelore lor the temperatures :

09 C. 6^C, lOoC. 15° C. 20° C. 25<>C. ZO^C.

the vohimes of a given quantity of alcohol are as the numbers :

1-00000 1-00523 1-01052 101585 102128 102680 1*03242

Alcohol has never been reduced to the solid state, but becomes viscid at very low
temperatures, as when it is surrounded with a mixture of solid carbonic acid and
ether under an exhausted receiver. It boils at 78*4^0. (173*1° Fah.) when the baro-
meter stands at 0-76 met (Gay-Lussac, Kopp.) Vapour-density » 1-613 (Gay-
Lussac) ; by calculation, for a condensation to 2 volumes, it is 1-591 when referred to

air as unity, and 23 when lefetred to hydrogen as unity ( 5 «» 23. j

Akohol has an enlivening odour and a burning taste, and .when unmixed with water
exerts a poisonous action. It is a very slow conductor of electricity.

Deeonmoeiiums, 1. By Seat. — ^Alcohol- vapour passed through a red-hot glass or por-
edain tuoe jrields carbonic anhydride, water, hydrogen, marsh-gas, olefiant gas, naphtha-
lin, empyreomatic oil and a deposit of charooaL K the tube he filled with fragments of
pumice-stone, the solid and liquid products consist of nalphthalin, benzol, hydrate of
phenyl, acetic add (?) and aldehyde, together with a number of solid compounds of not
veiy ddlnite character, some of them smelling like musk, others like garlic (Berthelot,
Ann. Ch. Phys. [3] xrriii. 285). Alcohol-vapour does not undeigo decomposition at
300® C. in a tube containing fragments of porcelain, but gives off gas even at 220^, if the
tube contains spongy platinum. (Beiset and Mi 11 on, Ann. Ch. Phys. [3] viii. 280.)

2. By EUetrtciUf, — Absolute alcohol scarcdy conducts the voltaic current, but when
pottth or potassium is dissolved in it, decomposition takes place, hydrogen being

74 ALCOHOL.

erolTed at ihe negative pole and aldehyde-xeBin fonned at the podtiTe pol<
(ConnelL)

3. By Oxygen, — Alcohol is very inflammable, and bnins in the air ^th a dnUbh
flame, yielduig water and carbonic acid. It does not readily deposit soot, eren vhen ti
snpply of air is limited, bnt absolute alcohol deposits it more readily than ordioary^iii
Aloohol-Tapour mixed with air explodes by contact with flame or by the deetrie spaxli

Imperfect Combttsiion, — When alcohol or its Taponr comes in oontaet with air, ai
at the same time with platinnm or certain other metals, an imperfect oxidation of tl
alcohol takes place, the metal being generally heated to redness, and the alcohol bei
oonyerted, partly into carbonic add and water, partly into aldehyde, acetic add, fSmrn
add, aoetal, and a peeoliar oom^nnd having an exeessiyely pnngent odoor. &m
metals exdte this action at ordmary temperatures, others only when more or 1<
heated; bat in all cases the action is more powerftd aa the metal is more finely divid
and oonseqnentiy exposes a laiger surfiice to the alcohol-vaponr. The most powei
action is exertea by plaiinum black. When this snbstanoe is shalien on paper m(
tened with alcohol, it makes a hissing noise and becomes red-hot» sometimes sett
Are to the alcohol, or else oontinning to glow, and indndng the slow combnstion ab
mentioned. If the platinum be previonidy moistened with a small quantity of wa
or at once covered completely with alcohol, the ignition is prevented, and the a
combustion induced with greater certainty. If a number of watdi-glasses oontaii
moist platinum black, be placed above a cush containing alcohol, and a bell jar opei
top inverted over them, the alcohol turns sour in a few weeks, and is found to con
alaehyde, aoetal, acetic add, and acetic ether.

This action of platinum black affords an excellent means of discovering thepresi
of alcohol in the air or in watery liquids. The liquid, neutralised, if necessary, '
alkali, to prevent the escape of volatile adds, is introduced into a retort, into the :
of which, and near the bulb, is thrust a littie boat containing platinum black, am
each side of this boat is placed a piece of litmus paper, in contact with the platu
The retort is then gently heated in the water-bath, when, if alcohol is pre
its vapour will be converted into acetic add by contact with the platinum black
the paper will be reddened (Buchheim). [Other volatile oiganio liquids might
a similiar action.]

Spongy platinum and dean platinum wire act in a similar manner to platinum 1
but not so quickly. If a coil of platinum wire be placed round the wick of a c
lamp, the alcohol set on fire till the wire becomes red-hot» and the flame then 1
out, the wire will continue to glow and the alcohol-vapour to bum slowly, prod
acetic add, aldehyde, &c The same effect is produced by a ball of spongy plat
This is the lamp tnthoutflame, or fflow lamp of Sir H. Davy.

4. By Chlorine, — Chlorine eas is rapi^y absorbed by alcohol, imparting t
yellow colour and causing considerable nse of temperature, which, if tne liqtdd
posed to ligh^ may even cause it to take flre. At the same time it rapidly ab
hydrogen, which is partiy replaced by chlorine, thereby producing hy<uochlori
aldehyde, acetal, acetic add, acetate of ethyl, chloride of ethyl, and finaJly cblora
mixture of these substances, freed by washing with water from the soluble oonsti
was formerly called heavy hydrochloric ether. The formation of these aeyeral p:
is represented by the following equations :

C"H«0 + 2 a » 0«H*0 + 2HC1

> r-— ' > r— '

Akobol. Aldehjde.

OE*0 + 6 a - C»HC1»0 +8HCa

Aldehyde. Chloral.

C«H*0 + Ha - OHK31 + H*0

AloohoL Chloride of

ethjl.

C«H*0 + B?0 + 4a - C«H*0« + 4Ha

Alcohol. Acetic acid.

C*H«0 + C»H*0< « C*H«0*.C*H» + HH)

>— » -^ ^- . — ^

Alcohol. Acetic add. Acetate of ethyl.

Acetate of ethyl may also be formed by the direct action of chlorine on the
thus:

2 C*H»0 + 4a - C«H»0«.C«H» + 4 Ha
The acetal, which is probably formed at the beginning of the procesA^ accord]
equation :

3C«H«0 + 2 a - C«H"0« + H*0 + 2Ha,

ALCOHOL. 75

is fir the mosl port sabseqiientlj oonTerted into aoetie acid':

C*H"0» + 4HH) + loa - ZCm*0» + IpHCl.

'When the sction of the chloiine is continued for a long time, chloral is always the
principal product.

Chlorine in pireeence of alkalis, conyerts alcohol into chloroform and carbonio
anhydride i

c«H«o + sa + o - CHa« + chci + cx)«.

ThB same products are formed by distilling dilute alcohol vith hypochlorite of cal*
eiiiB (efaloriae of Ume, bleaching powder). (See Chlobofobm.)

Bromime acts upon alcohol in a simiLar manner to chlorine, producing bromal, hydzo-
bromie acid, bromide of ethyl, bromide of carbon, formic acid, and oUier products not
jet tbostrag^y examined. Iodine is at first dissolved by alcohol without deoompoei-
tkn, and txroaa a brown solution ; but after a while, hymiodic acid is produced, and
actinff upon a portion of the alcohol, forms iodide of ethyL An aloohoHc solution of
pi^n tzested with iodine yields iodoform and iodide of potassium, the former of whicdi
compooads may be separated by water.

9. GUorieacid^ in uie concentrated state, sets fire to alcohol ; when diluted, it forms
icede acid, the action being sometimes attended with eyolution of chlorine. Perehlo'
fie add mixes with alcohol without decomposition at ordinary temperatures, but the
hquid when heated first gives off alcohol, then ether, and ultimately white yapoura
■molKwg like cnl of wine, tiie residue at the same time turning black.

10. Strong Nitrie acid decomposes alcohol, with great evolution of heat and brisk
ebollition, a mixture of various elastic fluids, the ethereal nitrtme ga$ of the older
diendsCB, being evolved and an acid liquid remaining behind ; if the nitrie acid is
dihite, the action does not take place without i^lication of heat. Part of the nitric acid
unites direetlT witii the alcohol, forming nitrate of ethyl, but the greater part is reduced
to nilzous acid which then forms nitrite of eth^l (nitrous ether) with a portion of the
akohol, while the remainder of the alcohol is oxidised andoonverted into aldehyde, aoetie
arid, formic add, saccharic acid, oxalic add, glyoxal, glyoxylic add, and glycolUo add,
tog^er with water and carbonic anhydride, which escapes as gas, together with nitric
oxide and the vapours of the more volatile among the compounds just mentioned. The
formation of ^yoxal, glyoxylic add, and glyoollic adds is represented by the equations :

C*H«0 + 80 = C*EPO« + 2HH)

Alcohol. Gljoxal.

C?HH) + 30 =» C«H*0« + H«0

Akokol. OljooUic add.

C*H»0* + O + HK) « C^*0*

-T-

lie

GlyoouL Gljonrl

If urea be added to the mixture of nitric add and alcohol so as to decompose the
mtrous acid as fast as it is formed (see Ubba), the chief product of the action is nitrate
of Hhyl NCCH*. Hydrocyanic add has also been obserred among the products ot
the action of nitric add upon alcohol.

When strong alcohol is heated with red faming nitric add (containing nitrous add)
and nitrate of silver or mercuric nitrate is added, white Aimes are given ofl^ containing
aldehyde and other oxidised products, and a aystalline deposit of fUminate of silver
or meremy is formed, its production being due to the action of the nitrous acid on the
alcohol: e.g.

C«H»0 + 2N0«Hg « C«N«Hg«0« + 3H*0

AlcoboL Mercuric Fulmtnata

nitrite. of mercury.

But when a solution of mercury in nitric add free from nitrous add is added at a
temperature below 100^ C. to alcohol of sp. gr. 0.944, no action takes place at first; but
on raising the temperature to 100^, a white crystalline precipitate is formed, which is
a compound of mercuric nitrate with a nitrate of ethyl in which the whole of the hydro-
gen is replaced by mercuiy (Sobrero and Selmi; Oerhardt):

2N0^ + 3 Hg*0 + CJ«H*0 - NO^.NO«(C»Hg») + HH) + 3 H«0

CryiUlUne compooiuL

11. Sulphuric acid forms with alcohol, a number of products varying in quantity
according to the proportions in which the two liquids are mixed, their degree of con-
centration, and the temperature to which the mixture is exposed.

76 ALCOHOL.

Strong snlphimc acid mixes with alcohol, prodnciiig consideTable eTohtion of heal
and fonns etnjl-sulphuric or snlphovinic add, the acid being at the same time brongl!
to a greater atote or dilation :

C«H».H.O + SO*.H» - SO^H.C«H» + HH)

^ ,_^ , '

Alcohol. Etbyl-sulphorle

add.

When the strongest snlphnric acid (sp. gr. 1*825) is digested for some time at
gentle heat, with excess of absolute alcohol, more thaii half the sulphuric acid is co
Terted into ethyl-sulphuric acid. If the acid or the alcohol is diluted with vater, a co
siderable quantily of the sulphuric acid remains unaltered. Sulphuric acid oontaini
1 at. water (SO^U'.HK)) forms ethyl-sulphuric acid only when heated. As the fern
tion of etbyl-sulphuric add is necessarily accompanied 'by that of water, a ceiti
portion of the sulphuric add must always remain unconverted into ethyl-snlphu
add.

Formation of Ether, — ^A mixture of 1 pt. alcohol, and from 1 to 2 pts. strong sulp]
ric add heated in a distillatory apparatus, boils between 120° and 14(^ C, at first gir
off ether, together with more or less undecomposed alcohol, l^en at 140^ ecaroely a
thing but ether, at 160° ether and water, — and at length when, in consequence of
decompodtion of the alcohol, the proportion of sulphuric acid has become excess
and the temperature rises above 100°, the mixture blackens and gives off defiant
togeUier with sulphurous add and other products hereafter to be mentioned. If h
ever the alcohol be allowed to flow constantly into the vessd in a thin stream, so a
maintain the proportion of 5 pts. alcohol to 9 pts. sulphuric add, the temperature
mains constant at about 160°, no sulphurous add or olefiant gas is formed, but
alcohol, as fast as it is supplied, is given off again in the form of ether and water.

The alcohol converts a molecule of sulphuric add into ethyl-sulphuric add and w^
mi ftbove *

C*H».H.O + BO\W - SO*.C«H».H + HH>

AlcohoL Sulphurie Ethjl-tutphuric 'Water,
acid. acid.

and the ethyl-sulphuric add coming in contact with another molecule of alcohol, j
ether and sulphuric add :

SO*.C*H».H + C«H».H.O - (C*H»)«0 + SO*H«.

Etbyl-tulphuric Alcohol. Ether. Sulphuric

add. acid.

The sulphuric add thus reproduced acts in like manner upon another molec
alcohol, and in this way the process continues as long as the supply of alcohol i
up. Etheriflcation is therefore a continuous process, a given quaotil^^ of sul]
add being capable of etherifying a very large quantity of aloohoL The water,
ever does not all pass off as it is formed, so diat the sulphuric add becomes oonti
though slowly weaker, and consequently a continually larger quantity of alcohol
over undecomposed with the ether and water.

The explanation just given of the process of etheriflcation is due to Willis
(Chem. SoG, Qu. J. iv. 106, 229). Its correctness is strikingly exhibited 1
analogous reaction which takes place between common alcohol and amyl-sulpburi
When amyl-alcohol is dissolved in sulphuric add, amyl-sulphuric add is produ<

C»H»>.H.O + SO*H« - SO*.C»H".H + H«0.
Now, on heating this mixture and passing a stream of ordinary alcohol throug
above, ethamylic ether, or oxide of ethyl and amyl passes over first, then c
ether, and ethyl-sulphuric add remains behind in place of amyl-sulphuric add

SO*.C»H".H + C»H».H.O « C»H».C»H".0 + SO*H«

Amyl-tulphuric Alcohol. Oxide of ethyl Sulphuric

acid. and amyl. acid.

The sulphuric add thus reproduced acts upon the ethyl-alcohol in the maziner
described, the products being ethyl-sulphunc acid, ether, and water. The same '
are obtained by distilling a mixture of ethyl-alcohol and amyl-alcohol with s
add.

The formation of ether from alcohol was formerlv regarded as a simple pi
dehydration. Ether being regarded as C*IPO and alcohol as its hydrate, C*j
it was supposed that the sulphuric acid simply ab8tract«d the water and left t
Against this view, however, it must be alleged that the quantity of water gi^
the distillation is very nearly equal to the whole quantity supposed to be f
from the alcohol, which could not be the case if it were retained by the sulph*
Moreover, the molecule of ether referred to the same vapour-volume aa "that o

ALCOHOL. 77

C'iPO', ii not C*H*0, bat C*iP*0*; or, according to the atomic weights adopted in
thia vori^ alcohol being CH'O, ether is C*H^*0. For these reasons, Hitscnerlieh,
Batzdhu^ and other diemists haTe regarded the action of snlphnric add upon alcohol
as ^wntaistrCfeUon^ or caUdyHe oeHon, a mode of expression which simply states the fiwt
vitboat ei^Iaiiiing it.

Anotlwr objection to the Tiews jnst mentioned, is that they take no account of the
finmation of ethyl-sulpburic acid. That this, however, is an essential step in the process
of etheriftcation is shown by the fact that, on distining amixture of alcohol and strong sul-
phuric add, the quantLtjr of eth^l-sulphuric add constantly diminishes as the ether passes
over, and that, if the add be diluted so far as not to form ethyl-sulphuric add, the mix-
tnrppeUb no etber by distillation. Liebig therefore supposed that the ethyl-solphuric
add IS resolTed at a certain temperature (120^ to 140^ C.) into ether, sulphuric acid, and
aulpfanrie anhydride :

2(C*BP.H.SCH) =- C*H»0 + SO«H» + S0«

and that the sulphuric anhydride, unitine with water also present in the mixture, re-
produees sah>huric add. But ethyl-sulphuric add when heated alone giyes off, not
ether hat alcohol, even when heated to 140° or above in sealed tub^ ; but when
heated with alcohol, it immediately yields ether. We are therefore led to regard the
loxmation of ether as a resolt of the mutual decomposition of alcohol and ethyl-ralphuric
add, in the manner already explained.

When alcohol and strong sulphuric add are heated together in sealed tubes, the
alcobol bdn^ in excess, a layer of ether Ibrms on the top of the liquid, but no ethyl-sul-
l^raric add is found in the lower stratum. If the sulphuric add is in excess, no ether
» fonned (Grab am , Chem. Soc Qu. J. iii. 24). In the former case, it is probable that
ethyl-fluj^huric add was first formed, and afterwards converted by the excess of alcohol
into ether and sulphuric add. Add sulphate of potasdum (Graham) and various other
sulphates heated with alcohol in sealed tubes, also etheri^ it more or less completely,
the sulphate being in some cases converted into a basic salt. The alums, namely
common alum, anmionia-alum, potassio-ferric sulphate, and potassio-chromic sulphate
heated with an equal weight of 98 per cent, alcoho], etherify it completely. In sll
these cases, the sulphate appears to give up a portion of its sulphuric add, which then
acts on the alcohol as above. (Reynoso, Ann. Ch. Phys. [3] xxviii. 385.)

FormiUicm of Oi^fiani gat, — When 1 pt. of alcohol is nested with 3 or 4 pts. of
strong sulphmric add, the mixture begins, between 160° and 180° C, to blacken and
thidben, swells up considerably and gives off olefiant gas C^\ together with variable
qnantitiea of sulphurous anhydride, carbonic anhydride, carbonic oxide, oil of wine,
acetic add, acetic ether and ^srmic add, and a black reddue is ultimately left con-
sisting of a peculiar add called thiomelanic add and free sulphuric add. £y pasdng
alcohol-vapour through a boiling mixture of 10 pts. of strong sulphuric aad and
3 pta. of water, olefiimt gas and water are obtain^ with scarcdy any coloration of
the mixture or fonnation of secondary products :

CTI*0 - C*H* + H*0.

12. Sulpkurio anhydride, SO*, is dissolved by absolute alcohol, with evolution of heat,
and Ibrms neutral sulphate of ethyl SO^(C^*)*. When the vapour of the anhy-
dride is passed into abeolute alcohol, crystals of sulphate of carbyl, G'H^280', are
ibimed, together with ethionic, isethionic, ethyl-sulphuric and sulphuric acids.

18. Fkotphoric add mixed with alcohol at ordinaiy temperatures, converts part of
it into ethja-phoephoric add. A mixture of phosphoric acid with a small quantity of
alcohol 27^^ olefiant gas but no ether ; but if the alcohol is in excess, ether is first
given ofl^ then olefiant toB and a thick add distillate probably consisting of neutral
phosphate of ethyl, P0*.(U'J1*)*. Phosphoric anhydride absorbs the vapour of an-
hj^droos alcohol, forming ethyl-phosphonc acid PO^C*H*.H*, and diethylphosphoric
add, PO*.(CH*)^H. Jreenie acid acts veiy much like phosphoric add, proaudng
ether and ethyl-arsenic add. Boric anhydride (vitrefled boric add) in the state of
powder heated with absolute alcohol, gives off olefiant gas and leaves boric add.

14. HydrochUmo add sas is absorbed in large quantity by alcohol, and the eolation
when heated gives off chloride of ethyL The same compound is obtained by distilling
alcohol with strong hydrochloric add, or with a mixture of common salt and sulphuric
add; but iHien a mixture of hydrochloric add with a large excess of alcohol, dther
anhydrous or hydrat«d, is heated to 240° in a sealed tube, ether is formed as well as
cfaknido of ethyl, these two liquids forming a layer on the surface, while the lower
stratum consists chiefly of water and hydrochloric add. The ether results &om the
action of alcohol on the chloride of ethyl abeady formed :

C«H».C1 + C»H».H.O - ipWfO + Ha

78 ALCOHOL.

The same tnmflfomiatioii takes place, though dowly, even at lOO^' C. (A. Reynoso^
Ann. Gh. Phjs. [3] zlviii. 886.)

16. ^Sjuij metallic ckloridefBictnipontJi^^ acid*

UEodncing ether and chloride of ethjL Chloride of zine oonyerts anhjdiona alcohol
into chloride of ethyl with a small quantity of ether. With hydrated alcohol, it yields
at 166^0^ ether and oil of wine, the qnantilr of which increases as the distillationgoes
on ; hydrodiloric acid is also given otE, and basic chloride of zinc remains. Vfhea.
didiloride of tin is distilled witii a considerable qnantity of alcohol, ether and chloride
of ethyl pass over between 140^ and 170^, afterwards a componnd of chloride of et&yl
with dichloride of tin. (Knhlmann, Ann. Oh. Pharm. zzxiii. 97, 192.)

Omtallised protochlonde of tin distilled with alcohol yields ether, but no chloride
of ethyl (Karehand) ; the same decomposition takes place in a sealed tube at 240^.
CiystaUised chloride ofman^aneee and protochloride of iron also etherify alcohol com-
pletely when heated with it in sealed tabes to 240^; the chlorides c^ cadmium^ nickd^
and cobalt partially ; in all these cases, the etheriflcation takes place without blacken-
ing of the contents of the tube, and with little or no escape of gas when it is opened
(B ey noso, Ann. Gh. Phys. [2] zlviiL 386). The formation of eUier in these reactions,
may be explained by the following equations, given by Williamson for the case of
chloride of zinc:

C«H».H.O + Zna ■= C«H».Zn.O + HCl.
C«H».H.O + HCa - C«H».a + H*0.
C«H».a + C«H».Zn.O « ((?H»)«0 + ZnCL

With seeqtdchloride of iron, alcohol yields ether and chloride of ethyl between lS(fi
and 140^., afterwards hydrochloric acid and water, the residue consisting of sesqui-
chloride of iron mixed with sesquioxide. With chloride of aluminium, chloride of
ethyl is given off between 170^ and 200^, afterwards hydrochloric acid, and alumina is
left behind. Trichloride and pentachloride of antimony convert alcohol into chloride
of ethyl, with a little ether, tlie residue consisting chiedy of oxychloride of antimony.
Protochloride of platinum boiled with alcohol of sp. gr. 0*813 to 0-893 is converted
into a black explosive powder called detonating platinum-depoeit, 0"M*PtK), the liquid
acquiring a strong acid reaction and the odour of chloride of ethyl :

CHH) + 2PtCl - C«H«Pt«0 + 2HCL

The chloride of ethyl is formed by the action of the hydrochloric acid on another por-
tion of the alcohoL (Zeise.)

Asolution of 1 pt of dichloride of platinum in 10 pts. of alcohol of sp. gr. 0*823, dis-
tilled to ^ yields aldehyde, chloride of ethyl, and hydrochlorie acid^ The residual
dark brown liquid deposits a considerable quautitv of the black detonating powder
just mentioned, and retains in- solution the so-called inflammable chloride of platinum,
C«H*Pt«Cl«, according to Zeise, or C«H»Pt«Cl«, accorcQng to Liebig. Its formation
is represented by one of the following equations :

2C*RK> + 2PtCl« «- C^*Pt*Cl« + C«H*0 + HK) + 2Ha (Zeise.)

Aldehyde.

8C*H«0 + 4PtCl« - 2C«H^«a« + C«H*0 + 2H«0 + 4HCL (Liebig.)

^^ — I — '

Aldehyde.

The formation of &e black deposit is not an essential part of the reaction, and in-
deed takes place most abundantly when the dichloride of platinum contains proto-
chloride.

Mercuric chloride, HgCl, dissolved in alcohol ia slowly reduced to mercuious chloride
Hg>CL Potaah added in excess to the alcoholic solution heated to 60^C., forms an amor-
phous ^ellowprecipitate containing carbon, hydroffen, oxyeen and mereuzy, the hydrogen
being in smaller proportion than in alcohol This precipitate heated to 200^, explodes
without leaving any residue ; heated in the moist state, it decomposes less violently,
yielding mercury, water, and acetic acid (Sobrero and Selmi). Gerhardt and
Werther did not succeed in preparing this compound.

16. Trichloride of phosphorus reamly decomposes alcohol, forming chloride of ethyl«
hydrochloric acid, tnbaac phosphite of ethyl and phosphorous acid. (B 6 champ
Compt. rend. xL 944.)

6(C«H».H.O) + 2 Pa« - 3C^»a + 8 Ha + PO».(C«H»)« + PO».H».

17.^ With pentachloride of phosphorus, the products are chloride of ethyl, hydro-
chloric and ddorophosphoric acid, J?CI*0 :

C*H».H.O + PCI».C1« - C«H»C1 + Ha + pa«.o.

ALCOHOL. 79

I& PaUanUfkitU ofpiotpkoruSf on the other band, oonTerto alcohol, not into two
flcpante mlphidee^ but into the single compound mereaptan, or anlphide of ethyl
andhydiogen:

^CTPJBLO) + P«» - 6(C«H».H.S) + PW.

Theae last two reactions iQnstrste in a strildng manner, the difference between mon-
atomie and diatomic elements or radicles. In the former, the sin^e atom of oxygen
in alcohol is replaced hj two atoms of chlorine, one of which unites with the ethyl,
and the other with the hydrogen of the alcohol, foiming two perfectly distinct chlorides;
whereas in the latter, the oi^gen of the alcohol is replaced by 1 atom of tiie diatomic
element, snlphnr, which being indiTisible, binds together the ethyl and hydrogen
into one single molecule of mereaptan. f Compare page 11.)

19. Hie bromidm and iodides at phosjmoms, hy wgen, and the metals, act lilce the
cfaloridea. J^droftvoric add appears to cony^ alcohol into fluoride of ethyl.

20. Poiasnum and todium rapidly decompose absolute alcohol, 1 atom of hydrogen
being erohred and its place snpphed by the metal ; the resulting compound is an ethyl-
ate rf potassium (C*H'KO) or ethylate of sodium, which crystSlises from the saturati^
solution. The same compound appears to be formed by dissolving hydrate of pot-assium
or sodinm in absolnte alcohol:

C*E*M,0 + KHO « C«H».K.O + HK)

Hie ablution thus obtained exhibits in many cases the same reactions as that which is
produced W dissolying the metal in alcohol.

21. Alcohol heated with hydrate of potassium (or sodium) yields hydrogen gas and
an acetate:

C*H«0 + KHO - C«H»KO« + 4H.

To pndaee this decomposition, a mixture of equal weights of the alkaline hydrate and
ponnded quick lime is moistened with alcohc^ the excess of alcohol driven off at 100^,
toad the mixture gently heated -without access of air. Hydrogen is then evolved,
together with a snmU quantity of marsh gas, and the residue contains acetate of potas>
Mum, -which, at a hi^er temperature, is resolyed into marsh gas and carbonate of
polas8inm(p. 17).

22. Alcohol-vapour passed over anhydrous baryta heated nearly to redness, yields
defiant gas, marsh gas and hydrogen, with a residue of carbonate of barium.

23w Gaseous chloride of cyanogen is readily absorbed by alcohol, but does not decom-
pose it immediately. AJter a few days however, or more quickly if a little water is
present or if the kquid is heated to 80^, chloride of ammonium separates out, while
chloride of ethyl, caroamate of ethyl (uretiiane) and carbonate of ethyl remain in solu-
tion. The urethane and carbonate of ethyl are formed in the manner r^esented by
the two following equations :

C*H«0 + CNCa + H*0 « C»H^O« + HCl

Urethane.
20B«0 + CNCl + H«0 - CO«(Cra»)« + NH*C1

- ,1, _ -*

Carbonate of
ethyl.

The diknide of ethjd results from the action of the hydrochbric acid, produced as in
the first equation, on the aloohoL (Wurtz. Ann. Ch. Pharm. Ixxix. 77.)

24. Mnny oryaiKic acids when heated with alcohol convert it into compound ethers,
with elimination ^ 1, 2, or 8 atoms of water, according as the add is monobasic
dibaaicvortzibaaic: s.y.

C«H».H.O + C5*HK).H.O - C^»O.C*H».0 + HK)

AkdioL Acetic acid. Acetic ether.

2(C«H».H.O) + CO*.H».0« - CO*(C»H»)*0« + 2HK)
Alcohol. Oxalic acid. Oxalic ether.

8(0^*.H.O) + CyHK)*.H'.0; - G^*0\(0«Hy.q» + 8H«0

Alcohol. atric add. Citric ether.

'With some acids, e.g, acetic and bnlyric acids, the transformation is easily effected ;
with others, as oxalic and hippuric add, it takes a considerable time : in other cases
again, as witii baozoic add, no ether is formed when the add and the alcohol are merely

80 ALCOHOLATES— ALCOHOLOMETRY

distilled toffether; bat on passing hydrochloric gas into the alooholic solution of ti
acid, the euier is qtiiddy ibrmed. In this caae, chloride of ethyl is first ionned az
afterwaidfl decompoeed by the organic acid. Other strong minonl adds, such is st
phuric add, also facilitate the formation of these compound ethers.

Many poWbasie oisanic adds form add ethers wnen digested with alcohol ; th
tartaric add forms ethyl-tartaric add C*B.K)\C*R*JR)0*,

The anhydrides of monobadc adds qnickly convert alcohol into the oonespondi
ethers. (See Dictionary of Arts, Mant^acturea, and Mines,)

Co mp ounds of Alcohol. Alcohol has a tcit strong affinity for Vfoter^ and mi:
with it m all proportions. The mixture is attended with slight OTolation of heat, i
also with contraction of yolume, which gradually increases till the mixtore oonts
116 pts. water to 100 pts. alcohoL Strong alcohol absorbs moisture from the air.
abstracts water &om the moist parts of the animal body, and coagulates them if t
are of albuminous nature ; hence its use in the preservation of anatomical preparati(
From the same cause it destroys life in the veins.

Alcohol dissolves iodine and bromine ; also sulphur and phosphorus in small qi
titles. Gases for the most part dissolve in alcohol more readily than in water. I
Gasbs, ABSOBPnoir of.) Salts are, generally speaking, less soluble in alcohol tha
water ; indeed many salts quite insoluble in alcohol are easily soluble in water ;
the alkaline carbonates and sulphates. Chloride of mercury is, however, an excq
to the eeneral rule, being more soluble in alcohol than in water. Inorganic oompoi
sparingly soluble in water, are, for the most part, quite insoluble in alcohol ; so ukc
are efflorescent compoundis. But all deliquescent salts, excepting carbonate and ]
phate of potassium and a few others, are soluble in alcohol

Since alcohol does not dissolve all compounds which are soluble in water, it fo
that many substances, when dissolved in alcohol, do not exhibit the same rea<
towards other substances aa when dissolved in water. Thus many adds, whei
solved in absolute alcohol do not redden litmus or decompose carbonate of barii
calcium, probably because the resulting caldum or barium salt would be insolu
aloohoL

Alcohol readily dissolves resins^ ethers^ essential oils, fats, alkaloids, many ot
acids, and in general, all substances containing a larger proportion of hydrogen.

AxooHOULTBs. Alcohol unites in definite proportion with several salts, fc
crystallisable compounds, which however have but little stability and are alm(
decomposed by water. These compounds were first obtained by Grraham. (Gri
Phil. Map. Ann. iv. 265. 331 ; Einbrod^ Ann. Ch. Pharm. Ixv. 115 ; Cho-
ibid. Ixxi. 241; Lewy, Compt. rend. xxi. 371; Bobiquet, J. Pharm. [3]
161.)

Nitrate of magnesium dissolved in alcohol forms, on cooling from a boiling be
tion, a dystaUine mass like marsarin, containing 3CH'0.N0'Mg.

Fused chloride of calcium dissmves in absolute alcohol, and the solution if aorr
with ice, deposits aystals containing 2C'H'0.CaGL This compound subjected
distillation yields nothing but carburetted hydrogen. If the aJoohol oontains i
quantity (about 1 per cent.) of water, the solution yields by evaporation aomel
ciystalline mass, sometimes a syrup, which driesup in vacuo to a wMte am*
mass. Both the crystals and the syrup contain 20*^*0.30801 + H*0.

Chlorids of zinc forms with absolute alcohol a crystalline compound wbicli <
0*H"O.ZnC!l, and yidds when heated, alcohol, chloride of ethyl, hydrochloric f
oxide of zinc, but no ether.

JDichloride of tin and absolute alcohol, brought together in a vessel immei
freezing mixture, unite immediatdy, and on evaporating the solution in vac
sulphuric add and sticks of potash, crystals are formed containing 4G^S*OJ
The crystals are very soluble in alcohol. They distil at 80^ almost without d
sition (Lewy.) By cooling a mixture of 11*5 pts. of anhydrous alcohol, and
of dichloride of tin in a fri^rific mixture, Bobiquet obtained a white powde
when dissolved in alcohol, yielded by evaporation in vacuo over sulphuric acid
containing 20«H»0.SnCl*.

With &ryta, alcohol forms the compound 20*HH).BaK). which is obtained
ing anhydrous baryta to absolute alcohol, filtering, and again adding baryta,
alcoholic solution be then boiled, the compoimd separates in the &nn. of a

Eredpitate which redissolves on cooling. Water added to the solution 'thn
ydrate of barium. (Berthelot^ Ann. Ch. Phys. [3] xlvi. 222.)
The following substances also form crystalline compounds with alcohol : seaqi
of iron, protochloride of iron nitrate of caldom, and protochloride of m
(Graham.)

ALCOHOLOMETBY.

He alcohol in all these oompounds may be regarded as analogous to water of czys-

ICfcltliBM. This name is frequently appHed to the organic baMB pro-

dneed by the aiibstitation of alcohol-radicles for thenydrogen in ammonia; such, as
eCfaylamme, pheoylamine^ &c. (See Axxnes.)

r. (Alooamiirie,) The yalne of spizitnons liqnors depends
iqMrn the qaantity of alcohol which they contain. This may be determined in yarions
ways : Tis. by the specific ffrtmtj of the mixtore, by its boiling-point, by the tension of
its npoor, by its rate of expansion, and by estimating the proportion of carbon contained
in it b^^ combustioa with oxide of copper. But of all these methods, that which depends
upon the density is almost always employed for practical pniposes, other methods being
TCSoited to only when the mixtnre of alcohol and water is associated with foreign
snhiitsingei^ sneh as sugar, or colonring matter, or salts, in sufficient quantity to produce
a material alterstian ^ the density.

To determine the amount of alcohol in a spirituous liquor by its density, it is neces-
suy to know beforehuid the density corresponding to each particular proportion of
ifeohol and water. If these liquids were capable of mixing without alteration of
Tofamieh the spedSc gravity of each particular mixture might be calculated fiom the
{Bopartkms of aloohd and water contained in it, and the known specific gravity of
absohite aloohoL This however is not the case, the combination of alcohol and water
being attended with a contraction of volume varying in amount with the temperatore.
For this reason the specifie gravity of each mixture of alcohol and water must be
determined by direct esperiment, and the results collected in tables.

The importanoe of this object for the purposes of revenue induced the British
gorenunent to employ Sir Charles Blagden to institute a very extensive and accurate
sedes of expeanments on the density of spirit of various degrees of strength. The
determiiiatioiDa^ which were made by Gilpin under Blagden's oireetion, were first pub-
Ivfaed in 1790, afterwards twice repeated to obtain greater accuracy, and published in
the Fhiloeophical Transactions for 1794.

The ^eofie gravity of the mixtores of alcohol and water was determined by accu-
latelv wpighJTig a quantity of the liquid in a flask having a long nairow neck, and
filled with it up to a certain maik, the weight of an equal quantity of distilled water
having been pccviously ascertained. In this manner, the spetnfic gravity of 40 mixtures
was detennined, each at 15 difierent temperatures. The standard alcohol used to mix-
when the vater was not absolute, but had a specific gravity of 0*82514; for oonve-
nienee however, it was supposed to be a 0*826, a corresponding deduction being
made fi»m aU the numbers in the table.

Tabls I. — Showing the Specific Gratfiiy of various mhhires of Jlcohol (of Specifie
Gratiiy 82500 ai 60^ Fakr,) and Water at different Tpmperatwres^ the Specific Gra-
tis of water at 60^ Fakr, hkng 100000.

Tbe
pore

100

craiotof

spirit to

5 gr. of

water.

100

graintof

spirit to

lOgr.of

water.

100

grains of

•pfrit to

\l gr. of

water.

100

grains of

spirit to

lOgr. of

water.

100

grains of

spirit to

S5gr.of

water.

100

grains of

spirit to

30gr. of

water.

100
grains of
spirit to
3ftgr.of

water.

100

grains of

spirit to

40gr.of

Water.

100

grains of

spirit to

45gr.or

water.

100,

grains of

spirit to

Mgr.of

water.

SOF.

-83896

-84995

•85957

•86826

•87685

88282

■88921

•89611

•90064

90568

•91023

83672

84769

85729

86587

87357

88069

88701

89294

89839

90346

90811

83445

84539

85507

86361

87184

87838

88481

89073

89617

90127

90696

83214

84310

86277

86131

86905

87613

88266

88849

89396

89909

90380

82977

84076

86042

85902

86676

87384

88030

88626

89174

89684

90160

82736

83834

84802

85664

86441

87160

87796

88393

88945

89468

89933

82500

83599

84568

86430

86208

86918

87669

88169

88720

89232

89707

82262

83362

84334

85193

85976

86686

87337

87938

88490

89006

89479

82023

83124

84092

84961

86736

86461

87106

87706

88264

88773

89262

81780

82878

83851

84710

86496

86212

86864

87466

88018

88638

89018

81530

82631

83603

84467

86248

86966

86622

87228

87776

88301

88781

81291

82396

83371

84243

86036

86757

86411

87021

87590

88120

88609

81044

S2150

83126

84001

84797

86518

86172

86787

87360

87889

88376

80794

81900

82877

83753

84650

86272

86928

86642

87114

87654

88146

100

80648

81667 82639

83513 84038

86031

86688

86302

86879

87421

87915

Vol. L

ALCOHOLOMETEY.

Tablb I. (continued).

Heat

100

grains of

spirit to

55gr.of

water.

100

grains of

tpirit to

GOgr. of

water.

100

graint of

spirit to

65gr. of

water.

100

grains of

spirit to

70 gr. of

water.

100
grains of
spirit to
75 gr. of

water.

100

grains of

spirit to

80gr. of

water.

100

grains of

spirit to

86gr.of

water.

100

graint of

tpirit to

90gr.of

wateir*

100

graint of

tpirit Co

95gr.of

water.

grain

•plrh

lOOgr

wan

30° F.

•91449

•91847

•92217

•92563

•92889

•93191

•98474

•93741

•93991

•942

91241

91640

92009

92355

92680

92986

93274

93541

98790

940

91026

91428

91799

92151

92476

92783

93072

93341

93592

938

90812

91211

91584

91937

92264'

92570

92859

93131

93382

986

90596

90997

91370

91723

92051

92358

92647

92919

98177

934

90367

90768

91144

91502

91837

92145

92436

92707

92963

982

90144

90549

90927

91287

91622

91933

92225

92499

92758

930

89920

90328

90707

91066

91400

91715

92010

92283

92546

927

89695

90104

90484

90847

91181

91493

91793

92069

92333

925

89464

89872

90252

90617

90952

91270

91569

91849

92111

923

89225

89639

90021

90385

90723

91046

91340

91622

91891

921

89043

89460

89843

90209

90558

90882

91186

91465

91729

919

88817

89230

89617

89988

90342

90668

90967

91248

91511

917

88588

89008

89390

89763

90119

90443

90747

91029

91290

915

100

88357

88769

89158

89536

89889

90215

90522

90805

91066

913

Heat.

grains of

spirit to

100 gr. of

water.

grains of

spirit to

100 gr. of

water.

graint of

tpirit to

100 gr. of

water.

graina of

spirit to

lOOgr.of

water.

graint of

spirit to

100 gr. of

water.

graint of

spirit to

lOOgr.of

water.

graint of

spirit to

100 gr. of

water.

graina of

spirit to

lOOgr.of

water.

graint of

tpirit to

lOOgr.of

water.

grain

tpirit

100 gi

wat

30° F.

•94447

•94675

•94920

•95173

•95429

•95681

-95944

•96209

•96470

•967

94249

94484

94734

94988

95246

95502

95772

96048

96315

965

94058

94295

94547

94802

95060

95328

95602

95879

96159

964

93860

94096

94348

94605

94871

95143

95423

95703

95993

962

93658

93897

94149

94414

94683

94958

95243

95534

95831

961

93452

93696

93948

94213

94486

94767

95057

95357

95662

959

93247

93493

93749

94018

94296

94579

94876

95181

95493

958

93040

93285

93546

93822

94099

94388

94689

95000

95318

956

92829

93076

93337

93616

93898

94193

94500

94813

95139

954

92613

92865

93132

93413

93695

93989

94301

94623

94957

952

92393

92646

92917

93201

93488

93785

94102

94431

94768

951

Heat.

grains of

spirit to

100 gr. of

water.

grains of

spirit to

lOOgr.of

water.

graint of

spirit to

100 gr. of

water.

grains of

spirit to

lOOgr.of

water.

graint of

spirit to

lOOgr.of

water.

grains of

spirit to

lOOgr.of

water.

grains of

spirit to

100 gr. of

water.

graint of

tpirit to

Mfogr.of

water.

6
graint
tpirit
100 gr.
watei

30° F.

•96967

•97200

•97418

•97635

•97860

98108

-98412

•98814

•9933

96840

97086

97319

97556

97801

98076

98397

98804

9934

96706

96967

97220

97472

97737

98033

98373

98795

9934

96563

96840

97110

97384

97666

97980

98338

98774

9933

96420

96708

96995

97284

97589

97920

98293

98745

9931

96272

96575

96877

97181

97500

97847

98239

98702

9928

96122

96437

96752

97074

97410

97771

98176

98654

9924

95962

96288

96620

96959

97309

97688

98106

98594

9919

95802

96143

96484

96836

97203

97596

98028

98527

9913

95638

95987

96344

96708

97086

97495

97943

98454

9906

95467

95826

96192

96568

96963

97385

97845

98367

9899

ALCOHOLOMETRY. 83

Gt^Ein's tables do not giTO diiectlj the quantity of absolute aloohol contained in spirit
d aaj giTen densitf . In this Tespect, however, they have been oompleted by the
ezpcnmenta of Tralles, who in 1811 (Gilbert's Annalen, zzzviii 386), determined
the spedile gravity of alcohol, dehydrated as completely as possible by means of
fhlorioe of calcimn, and likewise the strength of Gilpin's standard spint, having a
epeciAe gravity of 0*825 at 60^ F. He found that the specific gravity of absolute
aieohol at 60^ F. compared with that of water at its maximum density is 0*7939 (or
07M6 compared with water at 60^) and that GHlpin's standard spirit contains in 100
pflitB by weight, 89'2 parts of anhydrous alcohol, and 10*8 parts of water. Proceeding
upoB ^eae d^ta, Tralles calculated the proportions of absolute alcohol and water con-
tained in Bfixit of various densities ; the results are given in Table 11. p. 83.

The prcNDortions of aloohol in spirit of wine may be expressed either by weight or by
Tolnme. The ibnner mode of expression is by fiu the simpler and more definite,
becane tbe pcoportion b^ weight is independent of the temperature, whereas the
pnpofftioD by Tolume varies with the temperature, being affected by the different
rates of expansion of aloohol and water. For scientific purposes, therefore, the
Btzeogth of spizit is always expressed in percentage by weight In commerce,
on t£s eontruT, the method by volume is always adopted, spirit being generally
boQg^t and sold by measure, not by weight. It becomes theiH?fbre necessary to know
bow to caleolate the composition 1^ volume from the composition by weight and the
obsttiied mpedRc gravity.

Let 8 be the spedfle gravity of the spirit (mixture of alcohol and water) : a the
qoanftiity of aloohol in 100 puts by weighty and tiierefbre 100 - a the quantity of
water; Pthe volume of the sjpit referred to a unit of volume, such that a quantity
of water which fills it is the unit of weight (s. y. if the weight is eiq»rfossed in grammes,
V is measored in cubic centimetres) then :

100 « r . 8

If thai, tiie specific sravity of anhydrous alcohol at the observed temperature com-
pared with water at l£e same temperature be s, the volumes of alcohol and water con-
tained in the spirit are :

-• and 100 — a

and oonsequflntly, the proportions of alcohol and water in 100 volumes of the spirit
axe:

« 100 8 . i, , 1. ,

- • -fs- ■> 0. •» volumes of alcohol.

and: (100— a) ■ -^ ■- (100 — a) i9 volumes of water.

For example : fiom the table p. 86 it appears that spirit containing 77 '09 per cent of
alcohol by weight has at 60® F. a n>. gr. of 0*8555, merred to water at the same tem-
perature^ and the specific gravity of absolute alcohol referred to the same standard is
0*7946 : henoe the percentage of alcohol by volume is :

8555
77-09 • j^ - 83*00

and the peroentage by rolume of water is :

(100 — 77-00) . 0-8555 - 22*91 . 0*8555 » 20*60

the whole beii^ measured at 60® F.

The volumes of aloohol and water thus obtained amount together to more than 100,
in the preceding example to 103*60 ; and acooidingly, if 83*00 measures of aloohol be
mixed with 20*60 measures of water, both at 60® F., the mixture, after it has cooled to
60® F., win fill exactly 100 measures, and the spirit thus produced will contain
83 volumes per cent of alcohol. (Bespecting the contraction which takes place on
mixing aloohol and water in various proportionSi see Eudberg, Pogg. Ann. xiii. 196 ;
also ICopp» ibid, liii 356.)

When tne volume per cent in a mixture, of alcohol find water is given, the weight
per cent is found from the equation :

a.r-5

This, aeeording to the table (p. 85)spirit containing 68 volumes per cent of alcohol
has a ^ gr. of 0*8949 at 60® F. Hence the weight per cent of alcohol is :

7946

**-**• 8949 "• ^^'^
thai is to say : 100 lbs. of this spirit oontain 69*38 lbs. of alcohol and 39*62 lbs. of water.

0 2

ALCOHOLOMETRY.

The specific gravity of aqneous alcohol may be determined by any of the ordinary
methods ; either by weighing in a specific gravity bottle, or by means of the hydrometer
(See SpBocno Q&^vrrr and Htdbombteb) and thence the percentage of anhydrons
alcohol by weight and by volume may be determined by means of the preoedins formulas
and the tables to be given hereafter. To facilitate these determinations, hydrometeirB
are constracted with scales marking directly the percentage of alcohol by volume, and
sometimes also by weight, of the spirit in whida they are immersed. Such instni-
ments are called AiJOOHOLOicBTBBa. Three of them are in nse, vi& the alcoholometer
of Tralles, which gives the percentage volume for the temperature of 60^ F.
» 12} B. a 15| C. ; Gkiy-Lussac*s alcoholometer, which likewise indicates percentage
by volume at 15^ C.; and Meissner^s, which gives percentages both by wei^t
and volume, the latter for the temperature of 14^ B i- 17*5^ 0.

As the scales of these instruments are constructed for different temperatures, they
cannot be expected to agree exactly ; but the differences arising from, this cause are
trifling. Greater discrepancies however arise from the different experimental data
upon which the scales have been constructed ; that of Tralles beinff founded on the
exact and extensive observations of Gilpin, and Meissner^s on experiments of his own.
Gay-Lussac has not stated on what experimental data his observations are founded,
but his numbers agree very nearly with those of Tralles, the differences never exceed-
ing ^ per cent for the same specific gravity.

The following table gives the percentages of anhydrous alcohol both by weight and
volume of mixtures of alcohol and water, according to their specific gravity as determined
hj Tralles from the observations of Gtilpin ; also the specific gravities as detonnined by
Chiy-Lussac They are deduced from Tralles' numbers by multiplying by 1*0009.
The corresponding indications of the hydrometers of Beck, Baume, and Cartier, are

likewise added.

Tablb 11.

Volumac

per cent.

accord-

WeightB per cent.

Specl6c grsTftlei
according to Gilpin

Spedflc grarities
•coording to Gay-

Degreeior

Degreeiof
Baom^'B.
Hydro-
mety.

Degrees of
Cartier*!
Hydro-
meter.

inf to
Trdlei.

At 60° F.alftf C.

Luuac at W^ C.

droroeter.

1-0000

0-0

0-80

0-9986

—

1-60

9970

—.

—

...

2*40

9966

—

>—

3-20

9942

— .

1-0

4-00

9928

— .

1-2

4-81

9916

.—

1-4

-.—

—

5-62

9902

1-6

.—

—

6-43

0890

1-9

—

...

7-24

9878

-i^

8-06

9866

1-0000

2-3

8-87

9864

—

2-6

9-69

9844

—

2-7

10-61

9832

2-9

—

.i_

11-33

9821

—

8-1

^—

12-16

9811

8-3

.—

....

12-98

9800

—

8-6

...

13-80

9790

8-6

«_

14-63

9780

..^

3*8

, -

16-46

9770

—

4-0

—

16-28

9760

„_„

4-2

^^^

1711

9760

.-.

4-4

_—

...

17-96

9740

4-6

....

18-78

9729

^■^*

4-8

19-62

9719

.—

4*9

20-46

9709

21-30

9698

..-

6-3

—

2214

9688

22-99

9677

— .

6-7

m.^

...

23-84

9666

6-9

^..

24-69

9666

0-9666

6-1

....

26-66

9643

6-4

...

26-41

9631

6-6

—

ALCOHOLOMETRY.

Table U, (eonHnued),

JToiiaMi
urecBC

SpecUfe GniTltiei

Soeciflc Oravitiei

Degreeeof
Bnck't

Degrees of

Degreeeof

eOBOCQ«

Wcighu per cent.

aeeording to Gilpin

according to Gat-

Cartler'ft

Baumi't

iBKtO

■t60»F.Bl9|C.

Lussac at lb'* C

Hydro*
meter.

aydrom
meter.

Hydro-
meter.

27-27

0-9618

0-9656

6-8

2813

9605

7-0

28-99

9592

9595

7-2

...•

29*86

9579

7-5

.i_

^^^

30-74

9565

•^

, ^

81-62

9660

8-0

82*50

9536

—

§-3

33-39

9619

9623

8-6

^mmm

84-28

9603

.1.

8-0

36-18

9487

9-2

...

86-08

9470

9-5

86-99

9452

9*8

..^

^■^

37-90

9435

9440

10-2

...

^i^W

38-82

9417

...

10-6

39-76

9399

10-9

...

40-66

9381 •

mm^

11-2

•_

41-50

9362

—

11-6

—

42-62

9343

9348

11-9

48-47

9323

...

12-3

44-42

9803

«.

127

.._

^^^

45-36

9283

^^■

131

^_^

46-32

9262

—

13-5

47-29

9242

9248

18-9

48-26

9221

14*3

49-23

9200

14*8

50-21

9178

15-2

51-20

9156

—

15-6

—

52-20

9184

9141

16-1

53-20

9112

16-5

54-21

9090

170

M-H*

56-21

9067

17-5

66*22

9044

9141

18-0

57-24

9021

9027

18-4

59-27

8997

18-9

59-32

8973

m.^

19-4

..^

...

60-38

8949

200

61-42

8925

—

20-5

—

62-50

8900

8907

210

63-58

8875

21-5

64-66

8850

»i»

22-1

^.^

65-74

8824

22-6

66-83

8799

23-2

^^^^

67-93

8773

8799

23-8

69-05

8747

24-4

7018

8720

•_

260

71-81

8698

•.

26-6

72-45

8664

—

26-2

—

73-69

8639

8645

26-8

_ ^\ 81

7474

8611

27-4

w»M

75-91

8683

...

28-0

7700

8665

...

287

78-29

8526

29-4

79-50

8496

8602

30-1

8071

8466

—

80*8

o 8

ALCOHOLOMETRY.

Tablb IL {continued).

Volumm
percent

Specific Gravitlef

Specific GraTitlei

DegreMof

Degrees of
Bainn6*t
Hydro-
meter.

D^greaof

Cartier'*

Hydro-

meter*

accord-
ing to
Traltei.

WelghU pOT cent

according to Oil-
pin at 60o«l5|oa

itccording to GmA
Luuac at I5<> C.

Beck's Hy-
drometer

81*94

0-8436

0-8602

81*6

83*19

8406

—

82*2

...

— >

84-46

8373

—

33*0

86-76

8340

8346

83*8

,^_

87-09

8306

—

34*7

88-37

8272

—

86-6

89-71

8237

—

36-4

—

91-07

8201

—

37*3

92-46

8164

8168

38-2

93-89

8126

— -

39-2

—

96-34

8084

— .

40-3

96-84

8041

—

41-6

98*39

7996

—

42-7

100

10000

7946

7947

•

43-9

^—

The Tise of thiB table may be extended to intermediate numbers by interpolation.
Thna, if it be required to find the composition by yolume of a miztore of 60 lbs. of
anhydroTis alcohol and 60 lbs. of water, we find from the table that :

49'23 p. e. hj weight corresponds to 67 p. c bj yolume
and: 60* 2 „ ,. 68

and

t»

difference

0-98

Hence, to find the fraction which must be added to the number 67 togiye the percent-
age required, we haye the proportion :

0-98 : (60 - 49-23) » 1 : «
77

which giyes:

iii-*»»

Whence it appears that 100 yolumes (measured at 60^ F.} of a spirit containing equal
weights of alcohol and water contain 67*8 yolumes of alconol, also at 60^.

Again, let it be required to find the composition of a spirit haying at 60^ Fahr. the
specific grayitj 0*8966, compared with water at the same temperature; this number is
intermediate between the numbers 8949 and 8973 in the third column of the table,
which correspond to the yolume per centages 67 and 68 ; hence the proportion:

8973 - 8949 : 8973 - 8966 » 1 : x

which giyes

*"24"' *

that is to say, 100 measures of spirit of sp. 0*8966 at 60° Fahr. contain 671 measures of
anhydrous alcohol.

Meissner^s results are giyen in his "Araometriein ihrer Anwendung auf Chemie und
Tecknik," Wien, 1816. Th. ii 27. They differ somewhat from the preceding.

TjkBLB IL a. — Spedfie Gravity {according to Meistner) of Hydrated Jkohol containing

in 100 parts :

Alcohol

By Weight.

By Volume.

Pai|^.

At«l°C.

AtlT-S^C.

At 900 C.

At 17*S*» C.

100

0-791

0-793

0*791

0*798

0-806

0-801

0*809

0*811

0-818

0-822

0-824

0*828

0-831

0-836

0*839

0*843

0-843

0*847

0*864

0*867

0-866

0-869

0*867

0*869

0-868

0-870

0*880

0*883

ALCOHOLOMETEY.

Bj Weight.

Tabui n. a. (oontmued).

At 17-6' C.

0*883
0-896
0-906

0-917
0*928
0-939
0-948
0-968
0-966
0-971
0-977
0-983
0-991
1*000

By Volitmo.

At 80° C.

0-893
0*906
0-917
0-928
0-938
0-947
0-966
0*963
0-969
0-976
0-981
0-987
0-998
1-000

At I7-6' C.

0-896
0-907
0*919
0-930
0*940
0*949
0-968
0-964
0-WO
0*976
0-980
0-986
0-993
1-000

>591% t^^

JlsiU it given hy Fowne$ (Haxraal of Chemistry, 3zd
€fraoUie$ being taken at 16-6^ C. or 60 Falir.

nrcmtagt
bjr Wright.

0-098 X

o-eo-4'3r

0-9930
0-091'*

0-08S4
0-9809

0-984:1

0-981i(

0-978d
0-9778

0-9728

0-97l«
O-07O4
0-9891
O-0«78

O-90^^
0-98^5
0-9638

0-98S3
O-9099

0'9^^^
0-9^7B

Ptfomtage
by weight.

Spedfle OrsTitj.

0-9611

0-9490

0-9470

0-9462

0*9434

0-9416

0-9396

0*9376

0-9366

0-9336

0*9314

0-9292

0-9270

0-9249

0*9228

0-9206

0*9184

0*9160

0-9136

0-9113

0*9090

0*9069

0-9047

0-9026

0-9001

0*8979

p-8966

0*8932

0*8908

0*8886

0*8863

0*8840

0*8816

0-8793

Pereentage
by weight.

68
69
70
71
72
73
74
76
76

Spedfle Grai

0*8769
0*8746
0-8721
0-8696
0-8672
0-8649
0*8626
0*8608
0*8681
0*8667
0-8633
0-8608
0-8483
0-8468
0-8484
0*840S
0*8382
0*8367
0-833]
0*830£

0-827S
0-8264
0-822e
0-819{
0-8175
0-814(
0*81 li
0-808<
0*806]

0-8031

0-800]

0-7961

100

0*7931

e 4

ALCOHOLOMETRY.

It 18 often necessa^ to take tlie specific graTitj of spirit at a temperatoze different
from the standard. Li tiiat case, the percentage of alcohol may be determined hy means
of the two following tables, giyen by Tralles.

Tablb m. — Bpeeifio Chravity of Spirit of different gtrengths at Tsm^peraturei fn>m
Z(P Fahr, to IWP Fahr. that of Water at 39'83 Fakr. being - 10000.

Quantity of
Alcohol at

Temperaiuret (Fahr.)

•

60OFahr.
inperceau

•

40°. 45*>.

ages by.

80°.

88°.

50°.

55<».

60°.

65°.

70°.

75°.

80°.

85°.

90P.

95«.

100°.

Volume.

SISWB

iOOOO

10000

sftISM

9996

9991

9686

9980

9974
990f

9967

9951

9941

9991

9988

9929

9928

9926

9998

9919

9914

9908

9894

9816

9877

WJDO

9«57

9879

9878

9871

9869

oautt

iWOD

9069

9857

9851

9844

9837

9898

9820

9610

9800

9789

1ft

9887

98S5

9693

9819

9814

9808

9809

9795

9787

9777

9768

9758

9747

9785

9788

9790

9786

9780

9n4

9767

9759

9751

9749

9739

9791

9710

9696

9685

9679

9658

9756

9748

9789

9781

9791

9710

9700

9689

9G76

9664

9650

9687

9699

9607

9S9I

9719

9706

9697

9685

9679

9659

9646

9689

9618

9608

9587

9571

9555

9588

9591

9678

9668

9644

9699

9614

9599

9583

9566

9550

9538

9515

9497

9479

9461

9449

9613

9597

9560

9569

9545

9598

9510

9499

9478

9454

9435

9416

9896

9876

9366

9589

9581

9508

9484

9466

9446

94^

9407

9887

9367

9347

9896

9805

99»4

9268

9458

9454

9415

9895

9875

9855

9335

9814

9998

9979

9951

9929

9807

9185

9169

9358

9888

9318

9997

9976

9955

9284

9919

9191

9169

9147

9195

9102

9079

9056

99IV8

9988

9219

9191

9169

9148

9126

9104

9089

9069

9086

9018

8990

8867

894}

9148

9199

9101

9080

9058

9085

9018

8091

B96B

8045

8991

81198

8875

8851

8fl96

9095

9004

8889

8960

8987

8914

8892

8869

8846

8893

8799

8775

8751

8727

8709

8900

8878

8856

8888

8811

878S

8765

R749

8719

8695

8671

8646

8699

8596

8978

8768

8746

8798

8701

8678

8654

8631

8608

8584

8660

8585

8511

8487

8469

9487

8fi87

8604

8581

8558

8536

8511

8488 18464

8440

8416

8899

8367

8848

8318

8998

8472

8449

8496

849618380

8356 1 8339 | 8308 1 8984 1 8960

8235 ' 8211 1 8186 I 8161

8186

Tablb TY.-^Volumee of Alcohol of Specific Gravity 7939 (UfiO^ Fahr, which toould be
contained at 60^ Fahr, in 100 meaeures of Spirit exhibiting at the several TemperO'
turea (Fahr.) stated ai the heads of the columns the following apparent Specific Gra-
vities as determined trith a Glass vessel or instrument.

Volumei

of
Alcohol.

80°.

iffi.

40°.

45°.

50°.

65°.

60°.

66°.

70°.

75°.

80°.

85'».

. 10

9994
9924
9868
9893
9786

9997
9996
9869
9829
9789

9991/

9929
98G8
9890
9777

QOQB

9H96
9867
9817
9779

9997
9925
9865
9613
9766

9994
9922
9861
9807
9769

9991
9919
9857
9602
9751

9987
9915
9859
9796
0743

9981
9909
9M45
9788
9785

9976
9908

9889
9779
9793

9970
9897
9681
9771
9713

9969
9889
9693
9761
9701

95
80
85
40
45

9759
9715
9668
9609
9585

9745
9705
9655
9594
9518

9787
9694
9641
9577
9500

9729
9688
9697
9560
9489

9720
9671
8612
9544
9464

9709
9668
9598
9527
9445

9700
9546
9583
9610
9427

9600
9688
9567
9493
9406

9678
9619
9551
9474
9888

9666
9605
9535
9466
9869

9668

9690
9518
9438
9360

9640
9574
9500
9419
9399

50
55
60
65
70

9449
9854

9949
9140
9091

9481
9385
9280
9120
9001

9418
9816
9210
9W9
8960

9383
9295
9189
9078
8956

9374
9275
9168
9056
8986

9354
9254
9147
9034
8918

9335
9284
9126
9013
8899

9815
9913
9105
8999
8870

9994
9199
9088

MMQ
WUSr

8847

9274
9171
9061
8947
8825

9958
9160
9089
8924
8801

i989
9198
9016
8901
8778

75
80
85
90

8896
8764
8698
8469

8875
8743
8601
8446

8854
8721
8579
8493

8839

8556
8401

8810
8676
8583
8379

8787
8658

8510
8855

8765
8681
8488
8339

8748
8609

8465
8809

8790
8585
8441
8985

8697
8569
8468
8969

8678
8588

8894
8988

8649
8514
8370
8914

^■Ducn

ons roi

1 A Br A

US iNtnoMBirr.

To be

dedocU

id from

the Spc

clflc Gr

aTttles.

To be added to the Spedflc Orartt

let.

-5 1

-4 1

-8 1

-« 1

1 -«

0 1 +1 1 +9 1 +9 1 +8 1

•4-4

ALCOHOLOMETRY. 89

Ib UUe HL the spea&c g;raTity of the spirit is supposed to be compared with that
cfwMtet at the w»«-"'Tniiyn density, and to be conected for the ez^aiision of the yessel
or iBstrament with which the determination is made. These densities maj be lednced
to those compared with water at 60^ F. (as in Table II.), by multiplying them all by

1-0009.
To find by means of this table the strenfi;th of a spirit, when either the specific

gsrity or the temperatnre is not given ezac^ as in the tables, we proceed by interpo-
tion as in the ealcnlations connected with Table II. (p. 85.) Bat of neither tempe-
ntnre nor specific graTity is exactly given in the table, the (alcolation is made as in
the IbDowing example. Let it be required to find the strength of a spirit of sp. gr.
0-9321 at 77*^ F.

Spedflc Gnvity _.^

ftr cut. of Alcohol. ae75op. at8(PF. Dilferanoe.

45 9867 9347 20

50 9272 9251 21

Biflcrence T ""95 96

Hence the sp. gr. for 77^ F., and for :

45 p. c alcohol is 9367-2 x -^ - 9359

50 „ 9272-2 X ^ - 9263-6

Difference - 95*4

Galling this difiTerenoe 95, it follows that to each 1 per cent of alcohol there corre-
^xmds at 77^ F. a difference of 19 in the specific graTity, and consequently the Tolume
per eentk of aloohd corresponding to the specific grayity 9321 is

^, 9359 - 9321 .. ^ 38 , ^ , „ ^
45 + jg 45 + ~ — 47 YOL p. c

lliis resnlt shows that the spirit in question, when cooled down to the normal tern-
peratme of 60® F. contains in 100 measures, 47 measures of absolute alcohol; this is
not, howerer, the actual proportion by Tolume at 77°, because alcohol and water ex-
paod at different rates.

Table TV. exhibits in the same manner as Table III. th^ strength of spirit according
to its specific gravity, but on the supposition that the specific gravity is determinea
with a glass instrument, and is not corrected for the expansion of tiie glass : hence
the expression " apparent specific gravity."

If the specific gravity of a sample of spirit has been determined at one temperature
and its volume measured at another, the amount of alcohol in it may be calcmated as
in the following example : 350 quarts of spirit are measured out at 75° F., and the
nedfic gravity determined with a glass instrument at 65° F. is 0*8609. By Table lY.
the stzengtii of this spirit is 80 per cent, that is to say, 100 volimies of it measured at
60^ F. contain 80 voL of alcohoL By Table III. the specific gravities of spirit of 80°
percent forthe temperatures 60° and 75° are 8631 and 8560. Consequently the volumes
of a given weight of the spirit at 60^ and 75° are as 8560 : 8681, and therefore the 350

quarts of nnrit would, if cooled to 60°, measure 350 x ~--t <■ 347*12 quarts; and this

8631

volume of liquid at the strength of 80 per cent contains 277*7 quarts of real alcohoL

To ensure perfect accura^, the expansion of the vessel in which the R>irit is measured

ought to be taken into account; but for commercial purposes, to which calculations of

this kind diiefly apply, this correction is too small to be of any importance.

The quantity of alcohol of 60° F. in 100 volumes of spirit of the same temperature

is called the strength (Starke; force), of the spirit ; and the quantity of alcohol of 60° F.

in 100 volumes of spirit of any given temperature is called the real amount of alcohol

(wahrer Alkokoigehalt; Rieheue), Thus in the example just given, the strength of the

077.7
■pirit i. 80. Imt the re.1 ««onnt of dcohol i. ^^ X 100 - 79-3.

The f<Aowing Tables, Y. and YL, exhibit the strength and the real amount of alcohol
of a sample of spirit according to the indications of the alcoholometer and the ther-
mometer. If^ for example, the alcoholometer marks 75 per cent in a spirit whose
temperature is 50° F., we find firom line 16, column 6, of Table Y. that the strength
of the spirit is 767, and from the corresponding place in Table YL that its real amount
of alcohol is 77*1 per cent

ALCOHOLOMETRY.

Tablb '^.^Skowmg tk$ Amount of JJcoM which a ginm •aimpU of Bjtmi would
contain at 60^ F. acoordmg to the indication of a glass Mooholometsr, immersed init
at any oUm' temperature.

Strength of the Spirit, when teeted bj the Alcoholometer at the following tempenturct.

0»

9»

40 6«

8»

10«>

ia»

14«

169

18»

20»

2r»

94 B.

Indlctt
Akoh

9-6

7*6

12-5

17-6

29-ft

2ft

27-6

80 C.

86-6

46'ft

64*6

68*6

79-6

81-6

86 F.

0*4

0-4

0*4

0-4

0-2

S-4

ft-ft

ft-6

ft'ft

6-4

6-9

6*0

4-7

4-4

8-7

8-2

9*5

11-9

ll'l

11-0

10-9

10-7

10-4

10-1

9-7

9-2

8-8

7-8

7*8

1ft

17*8

17-4

17-0

16*ft

160

15-6

16-1

14-6

14-0

18-4

12-8

19-9

11-6

94*7

98*9

98-1

9S-8

21-7

90-9

90-2

19-6

16-8

18-0

17-2

16*6

16-7

81-9

80>1

88-9

980

871

26*1

25'9

94*4

28*6

22-6

21-6

20-7

19-8

866

86*4

84*8

888

83-8

31-8

80-2

29*2

99-8

27-8

90-3

26-8

94*3

Sft

41*4

40-4

89-8

88*8

87*8

36-9

86-2

84-2

83-2

82-2

81*2

809

29-1

46-1

4ft*l

44-1

48-1

49*1

41-9

40-2

89*2

88-2

87-2

86-2

3.V9

84*9

4ft

60-8

60-0

49-0

481

471

46-9

44-9

48-2

42-8

41-3

40*4

89*4

ft6'6

64-7

68-9

68-0

620

61-1

60-2

49-8

48-4

47*4

46-5

46*»

44-6

ftft

00-4

69-5

68-7

67-8

66-9

66-1

66-2

64-4

68-6

62-6

61-6

60-7

49-7

66*9

64-4

68«

69-7

61-9

611

60*2

69-4

66-6

67-6

66-7

66*8

64-9

70H)

69-8

68-ft

67-7

66-9

66-1

66-2

64-4

63-6

62-7

61-8

60-9

69-9

74*8

74*1

78-4

79HJ

71-8

71-0

70-2

69-4

68-6

C7-8

66-9

66-1

66-9

797

79-0

789

77-4

76-7

7*9

76-2

74-4

73-7

72-8

72-0

71-2

70-8

84*4

83-7

880

89-8

81-6

80-9

80-2

79-4

78-7

779

77-2

76*4

75<

Sft

89*1

88*6

87*8

87-9

86*6

86-8

86*1

84-5

83-7

88-0

82*8

81*5

80-8

98*7

98*9

99-6

99H)

91*4

90-8

90-1

89-6

88-8

88-2

87-6

86*8

86-1

96-9

97-7

97-1

96^

96-1

99-6

96-1

94-6

94-0

93*4

92-8

91-6

100

_■ — •

100-1

99-6

991

96-5

96-0

97-6

97-2

Tablb YL — Showing the Beal Amount of Jlcohol in Spirit at different Temperatures

according to the indications of a glass Alcoholometer.

iontof the
olometer.

Real Amoant of Aloohol at the following Temperaturee.

2°

4«

6«

8»

10°

12°

14°

Ifio

I80

9tf»

fSP

94»R.

9-6

7-5

12-5

17*5

22-5

27-6

80 C

86*6

45'5

54*5

63-6

72'6

81-6

86 F.

0-8

0*4

0-4

ft-4

5*5

6*5

ft'ft

6-4

5-2

6-0

4-7

4*4

4-1

8-7

8*2

2-5

11*1

11-1

11-0

10-9

10-7

10*4

10-1

9-7

9*2

8-7

8-3

7*8

7-3

1ft

17*7

17-4

17-1

16-4

160

15*5

151

14-5

14-0

13*4

12-8

12*2

11-5

24-9

94-0

28-1

22*4

21-7

21-0

90*2

19-5

18-8

18-0

n-i

16-4

15-6

81*8

80-2

29*2

28-2

»r2

26-2

252

24-3

28-4

22*5

216

207

19-8

37*0

857

34-6

83*4

32-4

31*3

802

29-2

28*2

27-2

96*2

25*2

24*2

42*0

407

89*6

38-S

37*4

36-2

85-2

84*1

33-1

32-1

31-0

80-0

28-9

466

45-5

44-5

434

42-3

41*2

40-2

89-1

88-0

870

86-0

850

»9

4ft

61-5

50-4

49-4

48-3

47-3

46*2

46 2

44*2

43-1

42-1

411

40-0

89-0

66-8

65-8

64*3

53*3

62*3

51*2

60-2

49-9

48-2

47-1

46-1

450

44-«

61*2

60-2

69-2

68*2

67*2

56*2

55*2

64*2

58^

62*2

61*9

60-9

49-9

66-2

69*2

64*2

63-2

6i-2

61*9

60*2

89-2

68*2

67*2

56-8

55-8

54-S

71-1

70-1

69*1

68*1

67-2

66-2

64-2

63-8

62*8

61-8

60-8

69-3

76-0

76 0

741

73-1

72-1

711

70-2

69-3

68-8

67-3

66*4

65-4

64-4

60-9

79-9

79*0

78*1

77*1

76*1

75-2

74-3

78-8

72-8

71*4

70-4

69*4

85*7

84-9

839

83-0

B2-0

81*1

80-2

79-3

78-3

774

7C-4

75-6

745

90-5

89*6

88-8

87-9

87*0

86-1

85*2

84-3

83-4

81-5

80*6

79-6

950

94*1

93-5

92-7

91-9

91-0

90*2

89-3

88-4

87-5

86^

857

84-8

99-6

986

96*0

97*4

96-5

95-8

95-2

94-3

93-5

997

91-9

91*1

90-2

100

—

100-8

100-2

99-6

990

96-3

97-6

969

95*7

The scale of Tralles* alcoholometer is constmcted as follows. Suppose the cylindrical
or prismatic stem of the instrument to be divided into a number of equal parts, of
arbitrazy length ; and let v be the volume of that portion of the neck between two
consecutive mvisions ; V the volume of liquid of sp. gr. 1, displaced hy the alcoholo-
meter, and P the weight of the alcoholometer; then

p - r. 1.

If now the division to which the instrument sinks in this liquid be mailced 0, the
divisions being numbered upwards therefrom, and if the instrument be immerBed in
spirit of specific gravity n to the mark «, we have

P- (r+ n«)«,
which equations give,

F-(r+nt;)«,orn-- ^j--lj =-' -j-

ALCOHOLOMETRY.

The arbitnzy quantity v is fixed by TralleB at such a magnitude that

n =. 10000 • ^^

"Saw he 60^ F. tlie q>eeifle gnmty of water compared with that of water at its mazi-
mim dendtj (Table L) is 0*9991 : hence tea the diyiaion in whieh the instroment
sinks in pore water at 60^, we find,

1^0-9991
»- 10000 . -5:5^51; »•

Again, spirit of 80 per cent has at 60^ F. the spi gr. 0'8631 : hence, for the diTision
to whidi the instrument sinks therein, we have

1—0-8631

* ^^^^ • -0^8631 ^^®7'

and in like manner the Tables of the other diyisions of the scale may be fonnd : they
are giyen in Table YIL

To endnate an alcoholometer by means of this table, the instroment is first im-
mened in pure water at 60^ F., and the point of the stem to which it sinks is marked
9. It is next immened in spirit of known strength, and the point marked to which
it sinks wlien the liquid is at 60^ F. Thus if spirit of 90 per cent be used, the num-
ber of the diTiflion will be

1-0-8340
« - ^^^ ' 0-8340 - 2002.

The interral between these two marks is then to be diTided into 2002—9 *i 1993
equal part% and the divisions continued upwards as fiur as 2697, which coiresponds
to absolute aloohoL The percentages in the first column of Table YIL are then
marked on the scale by the side of the numbers of the diyisions in the second
column.

To Toriff the scale of an alcoholometer already divided, the spedfic gravities of a
nmnber of samples of spirit varying in strength by nearly equal intervals between 0
and 100 per cent may be determined 1^ any of the ordinary methods ; the correspond-
ing strength found srom Tables L, II., or TTT. ; the temperatures of them all then
rrauced to 60^ F» ; and the alcoholometer immersed in them in order to ascertain
whether its indications agree with the strengths so determined. The intermediate
points may be tested by comparison with the numbers in the columns of Table VII.
■ "tHflerences."

Tabui \iL--AleoholomeUr-3calefor Volumes per Cent at 6(P F.

Anoant
of Alcohol

Length of

bBmericd

part of

Stem.

DliRsr.

Amount
of Alcohol

by
Volume.

Length of
Immerted
pert of
Stem.

Differ-
encei.

Amount
of Alcohol

by
Volume.

Length of

immerted

part of

Stem.

Dlflbr^
encca.

ySL..

277

688

288

608

299

628

310

648

321

669

332

690

344

712

108

366

736

121

367

768

133

380

782

146

393

806

167

407

830

169

420

864

180

434

879

191

449

906

202

466

931

213

481

967

224

498

984

236

616

1011

246

633

1039

266

661

1067

266

669

1096

ALCOHOLOMETRY.

Tablb YII^(c(miinued).

Amoimt

Length of

Amomt

Length of

Amount

Length of

of Alcohol

ImmerMd

Diflbr-

of Alcohol

immened

Dlfferw

of Alcohol

Immened

Differ.

pert of

enoes.

part of

ences.

part of

encee*

Volume.

Stem.

Volume.

Stem.

Volume.

Stem.

1125

1514

2002

1154

1550

2050

1184

1587

2099

1215

1624

2150

1246

1662

2203

1278

1701

2259

1310

1740

2318

1342

1781

2380

1375

1823

98 '

2447

1409

1866

2519

1443

1910

100

2597

1478

1955

The following is a mmilar table for percentages hy veight.

Tablb YJIL-^Akohohmeter-ecaU for Weighta por Cent, at 60<' F,

Amount

Alcohol

bjWeight

0
1
2
8
4
5
6
7
8
9

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
84

Length of

Immened

part of

Stem.

9
29
46
64
82
98
114
130
145
159
173
187
201
214
227
240
252
264
277
291
304
317
330
343
357
371
386
402
419'
435
452
469
487
507
527

Dlflbr-
enoet.

Amount

Alcohol

by Weight.

35
36
37
88
39
40
41
42
43
44
45
*46
47
48
49
50
51
52
53
54
56
56
57
58
59
60
61
62
63
64
65
66
67

Length of

Amount

Length of

immened

DiflSBf.

Immened

DIlTer-

part of
stem.

encet.

Alcohol
byWelgfat.

part of
Btem.

eneee.

547

1411

568

1442

589

1473

610

1505

633

1536

655

1568

677

1600

700

1632

724

1664

748

1697

772

1730

797

1763

822

1796

847

1830

873

1865

899

1901

925

1938

951

1975

978

2012

1005

2050

1033

2088

1061

2126

1089

2165

1117

2204

1145

2254

1173

2286

42 .

1202

2329

1231

2372

1261

2415

1290

2458

1320

2503

1350

2549

1380

100

2697

AlCOHOLOMETKY.

TuvHH otber hjdiometan or anametera ue also lued for
UliDg Uk apedfii! gnrit^ and ascettaiiiitig tile atrength of
^aiiti. SkMfa h^^ometei' ia tii« ons nsed in leT;iiig tha .

nirit dn^ in this eoontrj. Thii inatnuDeDt luu a four- ^
ndfd itam 6, diTided into 11 equal parts, and fitting into a
Inn ball a, vbich carriea at the bottom a small conicu stem e, ^
toimiiatuig in ■ peai^afaapad loaded bolb. It is olio pro- |
Tided Tith 9 dicolarveightii, numbered 10, 20, 30,10,60,60,
TO^ 80, 90, hanng slits 'bj vhich the; flt into the stem. The ^
i»tniiM!iit is a4JDat«d so as to float with the zero of the scale ■
niinriding with the imrfkM of the liquid in spirit of apedfic ^

gnvit; 0825 at 60°F. vhich is the " ttandaid aUohol" of the
eictse (p. 82). Inireaker spirit it will not aiiili bo low ; and if
the density of the liquid be ninch greater, it wUl he neceasar;

gather with the natnber on the scale which is at t£e lerel
ri tbe liquid, gires, hj meKoa of a table provided for the
pmpoae, the amount of proof spjrii ia the sample, proof
■rant bone, according to Act of Parliament, mch as at 61°
f ihr. wei^s 4J " mwJi ss an equal bulk of water, or in other
weida haa a H«cifie gravit; of 0-923077 at £1°, or 0-919 at
60° P.

When spirit ia said to be SO per cent (for sismple] oion
Jfif, tho meaning ia, that 100 msasnrea of this spirit,
rfwn ditnted with w«cr, wunld ^dd 130 measures of proof
B[irit; on the other hand, spirit SO per cant btUmi pret^
cCTlaiiw in 100 measares, 100—30 or 70 meaaniM of proof

It is often required tc find the qnaniitj of water which mmt be added to spirit
(ootaiiung a gcren percentage of alcohol in order to rednce it to a lower pCTCentoge.
If the actual and re(]iiiiedBiiKmnta are given in wei^ts per cent, a and a', the wei^t
'Of water to be added to 100 Ihs of sfdril to r«dae« ue percentage of alcobcJfrom
a to ■*, is giren hj the ^«porCioa :

100 4- «: a - 100 : »',

9 e

Thence I - loo/^ — 1 1
tuning SO lbs.
rcent., the qua

"(S-') =

If Pbethevagbt, and 5 the specific graTJ^ of l^e tpirit we have:
P - 100 &
andif to this we add tDTolnniM of water, the wei^t of which will hIm be w (its

mpl^ to reduce spirit of BO Tolnme« p. c. to spirit of 40 Tolnmes p.e. w« find,
I . 0-eeiO - 0-8639) - 108-99

ALCOHOLOMETRY.

The Tdnme of diluted spirit produced by the mixture is

100^
1/

In the example just giyen, 100 • j^ » 200 yolumes, less tiierefore than the sum of

the Yolumes of the li<|uids mixed*

On the principles jost explained, the nnmhen in the following table are calculated.
It must be observed, however, that the specific gravities are given as determined bj
Oay-Lussae, and correspond to 16° G. on which account the rosult of the calculation
just given does not agree exactly with the number in the table.

The original volumes per cent, of the spirit are placed at the tops of the columns,
and the percentages to which they are to be reduced in the first column of the table.
Thus to find how much water is required to reduce spirit of 76 per cent to 40 per cent
look in the column headed 70 for ^e number on a level with 40 in the first column ;
we thus find that 77*68 volumes is the quantity of water required:

Tablb IX. — Showing the quantity of Water reauired to reduce 100 ffolwnea of a

stronger Spirit to a Spirit of lower strength.

6-66

13-79

6-88

21-89

14-48

7-20

3106

2314

16-36

7-64

41-63

3303

24-66

16-37

8-16

63-66

44-48

86-44

26-47

17-68

8-76

67-87

67-90

48-07

38-32

28-63

19-02

9-47

84-71

73-90

63-04

62-43

41-73

31-26

20-47

10-36

106-34

93-30

81-38

69-64

67-78

4609

84-46

22-90

11-41

180*80

117-84

104-01

90-76

77-68

64*48

61-43

88-46

26-66

163-28

14801

132-88

117-82

102-84

87-93

7308

68-31

43-69

206-22

188-67

171-06

103-63

136-04

118-94

10171

84-64

67-46

266-12

246-16

224-30

263-61

182-83

162-21

141-66

121-16

100-73

366-80

329-84

304-01

278-26

262-68

226-98

201-43

176-96

160-65

606-27

471-00

436-86

402*81

368-83

334-91

30107

267-29

233-64

804-64

763-66

702-89

661-21

601-60

661-06

600-69

46019

399-86

A similar but much more extended table for this purpose is given by Oay-Lussac.
(See Haudworterbuch d. Chem. i. 604.)

To determine what quantity of a weaker spirit must be added to a stronger one to
produce a spirit of given mean percentage, we proceed as follows.

Let t; be the volume of alcohol in 100 measures of the stronger spirit, 8 its specific
gravity, and P its weight. Also let V^ be the volume of the weaker spirit added, 9^ its
percentage of alcohol, 8^ its specific gravity, and Pi its weight; and lastly, let V^ be
the volume of spirit resulting from the mixture, v^ its percentage of alcohol, 8^ its spe-
cific gravity, and P, its weight. Then :

P - 100 5 : Pi « FiSi : P, - P + Pi

or 100 8 + VxS^ = VA •
The quantity of alcohol contained in this mixture is,

(!)•

'' + Ioo*x

But since the mixed spirit is to contain V^ volumes per cent of alcohol, thia quantity
of alcohol is also represented by

Hence the equation :

Ta^a » 100 tr + FiVi . . . («),

And eliminating Ta between the equations (1) and (2), we have,

100 5f+ Fi-Si

«.

fa >i 100 « + VxVx

ALCOHOLOMETRT.

iteee veobtsm:

F-

100 - iSf - 100 iSf
^9

Hie immentor of this fraction is the qoantity of wtAeat which most he added to 100
foifaimes of the stronger spirit to prodnee a spirit of the requied* strength. The de-
Bominstor maj be written in the fonn,

ind is therefore the Tolmne of water which mnst be added to -^ Tolomes of spirit oon-

taioing v^ per cent of alcohol to bring it to the percentage v^.

To determine the amount of alcohol in spiritnons Hqnors, snch as wine or beer, con-
taining foreign matten^ as Tolatile oils» sugar, mndlage, saline substances, &c., the
Jkpad may be distilled, and the distillate, which will be free from the fixed imparities,
mtj be treated b j the methods already described. Volatile oils are for the most part of
TtttAj the same specific grarity as alcohol, and the small quantities of them A*^«i-i«g
in rinoos liquors do not make any essential difierence in the specific grarity.

Other physical chazacters haye also been resorted to for determining the strength of
apiiitDoos hqnors^ tis. the boilinff-point, Taponr-density, rate of expansion, &c.

The boiknff'poitU of hydrated alcohol has been proposed by Groning as a means
of dstctminiqg its strength. For this purpose, he has constructed tiie following
taUe.

Percent,
or AloohoL

40
46
60
60
60
66

According to Dalton, alcohol of 43 per cent boils at 84° C.

J. J. Pohl (Doiksehriften d. math, naturw. Classe d. Wien, Akad. IL abstr.
Wjen, Akad. Ber. 1860 ; Marz. 246 ; Jahresber. 1860, 466) has also determined the
boiling-point of hrdrated alcohol of various strengths. He finds that, at the commence-
nent^the ebullition, the thermometer remains constant for a short time, then slowly
rises a little, and afterwards remains constant for a somewhat longer time (from 4 to
16 seeouds whm 14-6 gims. of liquid were used). The temperatures at the second
•tatioiiaiy interfal axe giren in the following table (Bar. at 760 mm.)

F\BrC8nC.

BoOlngw

«rAloolMl.

Point.

. 96-3 C.

. 92-9

. 910

. 891

. 87-6

. 86-2

. 860

Boiling.

Percent.

BoHing.

Point.

of AlcoboL

Point.

841 C.

80-9 G

83-4

80*3

831

79-7

82-2

79-4

81-9

79-0

81-6

78-4

Pifcenlsse
orAkohoL

0
1
2

4
6
6

Boiling.
Point.

PercCTitase
of Alcoh^.

loo-ooo C.

7 . . . .

98-79

8 . . . .

97-82

9 . . . .

96-86

10 ... .

96-90

11 ... .

9602

12 ... .

94-21

Boiling.
Point

93-480 C.

92-70

92-03

91-40

90-88

90-27

The presence of sugar in the liquid up to 16 p. c. appears not to exert any pexvep-
^le influence on the boiUng-point (a mixture of 10 pts. alcohol with 16 sugar and 76
vater boiled at the same temperature as a mixture of 10 alcohol and 90 water).

Instruments, called EUnUUoKopes, for directly ascertaining the strength of hydrated
ikohol by its boiling-point, haye been constructed l^ Broissard-Yidal and by Conaty.
(See a report on these mstniments byB esprets, P ouille t, and Babinet, Complrend.
uvii 874. A description and figure of a Yidal-instmment are giyen in the Pharm. J.
Tnas. rii. 166.) Ur e (Pharm. J. Trans, rii. 166 ; Pharm. Centr. 1847, 422) by means
of an iastroment similar to Conatv's (which is merely an ordinary thermometer, haring
s moreible scale which can be shifted so as to correspond with the yariations of the
yuometer, and has the percentages of alcohol marked on it) has determined the boil-
ing-points of hydrated aioohol as follows:

ALCOHOL-RADICLES.

Boiling.

Specific

Boiling.

Foinu

Onrlty.

Point.

. 81-40 0.

0-9665 .

. S5'3<>

. 821

0-9729 .

. 87-2

. 82-6

0-9786 .

. 88-8

. 83-3

0-9850 .

. 91-3

. 841

0-9920 .

. 94-4

SfMcifle
Gravity.

0-9200 .

0-9321 .

0-9420 .

0-9516 .

0-9600 .

Silbermann lias propoAed to determine the strength of hydrated alcohol bj its rate
of expansion by heat, and has constmcted an instrument for the piirpose (Compt rend,
zxvii. 418). A thermometer is filled up to a certain mark mih tne spirit at 26^ C. and
after this uqnid has been exhausted of air by the air-pump, an observation is made
of the amoimt by which it expands when heated to 50^ 0. The amonnt of alcohol ia
then found by means of a sciede graduated by direct observation upon a number of
samples of spirit of known strength. The indications of this instrument aie not sen-
sibly affected by the presence of sugar or salts in the liquid.

Another instrument for the same purpose haa been constructed and described by
Maki n. (Chem. Soc Qu. J. ii. 224.)

For fnruier details on alcoholometry, see the new edition of Ur^s Dictionary o/Arts,
Manufactures and Mines^ toL l pp. 44-64.

The radides which, when they replace half the hy-
drogen in a molecule of water form alcohols, are capable of uniting, though not directly,
with chlorine bromine, iodine, cyanogen, oxygen, sulphur, &c., with the ruUdes of acida,
and with metals : in short they e^iibit in their chemical relations the character of
electro-positLYe elements or metals. Only a few of them have yet been isolated; and
of these, dl but one (allyl) belong to the first series of alcohob mentioned in the
preceding artide, and are represented by the general formula OH^'*'^, or C^H^'*'*.
They are obtained :

1. By the action of sodium, potassium, zinc, &c, at high temperatures, on their
iodides or bromides. In this manner ethyl was first isolated by Frankland. — 2, By
the dectrolysis of the adds of the series OJBC'O*. The general formula of the decom-
position is^

C-H*-0« = 0-»H>-> + C0« + H.

In this manner, acetic add, C*H*0^ yields methyl, CH* ; valeric add, G*H**0*, yields
tefeylor butyl, C*H*; caproic acid, C*H"0', yiel<u amyl, C*H"; and oananthyHc add
C'H"0' yidds hexyl or caproyl, C"H". — 3. Some of these radides, viz. trityl or propyl,
tetiyl, am^l and hexyl, are also found among the products of the dry distiUation of
Boghead Gannd coaL (Qr. Williams, Chem. Gaz. 1857, pp. 29 and 95.)

Methyl and ethyl are gaseous at ordinary temperatures ; trityl, tetrv!, amyl, and
hexyl, are liquids, the first boiling at 68^ C, the second at 108^, the third at 155®, and
and the fourtili at 202^. They do not unite directly with any of the dementaiy bodies,
and it has not yet been found possible to reproduce from them, by direct union,
any of the bodies of the methyl, ethjl series, ^ At the moment of isolation, how-
ever, from their iodides by the action of metais, they exhibit a strong tendency to
unite with the metal: in this maimer, zinc-ethyl, C*H*Zn and zinc-methyX CH'Zn, are
formed by the action of zinc on the iodides of those radides.

The constitution of these bodies has given rise to considerable discussion. The
formulsB OH?, 0"il\ &c, originally assign^ to them by FrankUnd and Kolbe, repre-
sent their vapours as condensed to 1 volume, whereas the usual mode of condensation
in organic compounds is to 2 volumes (see Atomio Yolxtkb). For this reason, and
likewise because all organic compounds whose formulae are well established, are found
to contain even numbers of hvdrogen-atoms, Q-erhardt (Oompt. chim. 1848, 19 ;
1849, 11) proposed to double the formuhe of these radides in the free state, making

CH* ) CH* )

them 0^* or q^, [ , O^H'* or ^s^s [ ^ This duplication of the formulsB was after-
wards supported by H of mann (C^em. Soc. J. iii. 121) on the ground that the boiling-
points of the consecutive terms of the series of these bodies differ by about 47^ O., an in-
terval more than double of that which generally ooiresponds to a difference of OH' in
bodies of the methyl, ethyl, trityl series, &c. But the decisive argument in &vonr of the
double formulffi is afforded by the experiments of Wurtz, yrho has shown that by the
action of mixtures of the iodides of these radides (iodide of ethyl and iodide of tetiyl,
for example) with sodium, or by the electrolysis of a mixture of the potassium-salts of
two fatty adds, e. g, acetate and oenanthylate of potassium, compound radicles are ob-

CH* ) CH* )

tained, viz. ethyl-tetryl, ^^j^Lmethyl-hexylQag,,^ &c; and moreover that when

these mixed radides are compared with the simple radides with double formulse, a
regular gradation of physical properties is observed as the number of atoms in the
molecule increases. This will be seen from the following table.

ALCOHOLS.

Ethjl-tetzjl .
Ethjl-amyl
MetbjI-liezyl .
Tetijl .
Tetzyi-amyl .
Amyl

Tebyl-hexyl .
BeKjl .

Formula.

CTH"

C*H"

;cH»
;c*H»

Off*

;c*H"

OH"

C*H»

OH"

:c«H»»

Specific

Gravity at

6<»C.

0-7011

0-7069

0-7067
0-7247
0-7413

?
0-7574

Tapour.Densitj

Observed.

3-053
3-522
3-426
4-070
4-466
4-966
4-917
5-983

Calculated.

2-972
8*466
3-466
3-939
4-423
4-907
4-907
6-874

BoHing-
Point.

62«C.

88«

82?
106
132
168
166
202

It 18 defir that if the Bimpler foramls of tetryl, amjl and hexjl wore retained, the
aioeofdanee between the gradation of properties and increase of atomic weight which
theprecedmg table exhibits would be completely lost.

^ewed in this light, the formation of the simple radicles is strictly analogoos to
that of the mixed radicles, as will be seen from the following equations :

C»H*I + OH1 + ZnZn = 2ZnI ¥ C»H*.OH»
and 2C«H»I + ZnZn = 2ZnI + C^H^.C^H*.

A&CMIO&B. The term alcohol, originally limited to one substance, viz. spirit of
vine, is now applied to a considerable number of oiganic compounds, many of which,
in their external characters, exhibit but little resemblance to common alcohoL The
alcohols are all compounds of carbon, hydrogen, and oxygen. They are divided into
several homologous groups, but their rational formulae may all be derived from one,

tvo^ or three molecules of water, ^VO, ;m[0^ xrsfO', by substitution of an or-

ganie radicle containing hydrogen and carbon for half the hydrogen in the type.
Alcohols are accordingly monatomic, diatomic, or triatomic, e.g. Ethyl-alcohol

(monatomic) = H [^* — Glycol (diatomic) « ^ H*[^'» — Glycerin (tria-

A. »foiimtOfnii> Aloohols. Of these there are several series, containing radicles
whose genoal formuIiB are C»H"« + \ OH*» - », C"H*»-', C"H*»-7.

1. Alcohols of the form C-H«- + *0 = OH'"*'| q. These alcohols, of which

nine, or perhaps ten, are at present known, are intimately related to the fatty acids (p.
60). To every alcohol of this series there corresponds an acid of the series C"H*°0*,
wrtucfa may be formed from the alcohol by oxidation, 0 being substituted for H^ The
fcXUjvring table exhibits the names and formulse of these alcohols, together with those
of those of the corresponding acids :

Alcohols,

Methyiie or protylic .
EithjDC or deutyHc .
Piopylie or tritylic .
Bnty lie or tetiyUc .
Amylic or pentylic
Gapzoylic or hexylic .
OBnanthyEc or heptylic
Gapiylic or octylic .
Cetylie . .
Cootylie .

Keliajlie > •
VolL

■!"

CH^O

CH'O

C»H»0

C*H»«0

C»H"0

CH'H)

C"H"0
C«H»0

Aci

ds, H

. CH«0«

Formic .

Acetic

. C«H*0«

Propionic

. C»H«0«

Butyric .

. C*HK)«

Valeric .

. G»H>«0«

Caproic .

. C-H'20»

(Enanthylic .

. CH"0«

Capiylic

. C»HW0«

Palmitic «

. C»«H«0«

Cerotic .

. c«^»«o«

Melissic .

, . C"H«K)«

98 ALCOHOLS.

These alcohoLs are also designated as Hydrates, or Kydrated Oxides, of Methyl^
Ethyl, Sec, or as Methylate, EtkylaU, Tritylaie, ^c. of Hydrogen. The numerical terms
protyl, deutyl, trityl, &c. were proposed by Gerhardt They are in most cases pre-
ferable to the older names : but the terms, methyl, ethyl, and amyl, are too much con-
secrated by use to be discarded.

Methyl-alcohol, or wood-spirit^ was first recognised as a compound similar in nature
and constitution to common alcohol by Dumas and PeHgot in 1835. In the following
year, the same chemists showed that ethal (cetyl-alcohol), a substance first obtained
from spermaceti by CheTreul in 1823, is also of alcoholic nature. Fusel-oil was re-
cognised as an alcohol somewhat later by Cahours and Balard. Cerotyl-alcohol and
melissyl-alcohol were discovered by Brodie in 1848 ; octyl-alcohol by Boms in 1851 ;
tetryl-alcohol by Wurtz in 1852 ; ttityl-aloohol by Chancel in 1852, and hexyl-alcohol
by Faget in the same year.

Methyl-alcohol is found among the products of the distillation of wood. Ethyl-
alcohol and the four following alcohols are produced by fermentation of sugar,
(C*H"0*), perhaps in the manner represented by the following equations :

CffK)* = 20«H«0 + 2C0«

Ethyl,
alcohol.

2C«H«0« « 2C'H«0 4- C«H«0 + 4C0« + HK)

Trityl- Ethjl-

alcohol. alcohol.

C«H>K)« - C*ff«0 + 2C0« + HK)

Tetryl-
alcohol.

3Cm"0« « 2C»H»K) + C»H»0 + 600* + 3H«0

Amvl- Ethyl-

aloohoL alcohol.

2C^»0« - 0»H>«0 + C»H"0 + 4C0« + 2HK>

Amyl- TrttyU

alconol. alcohol.

5(>H»K)« = 4C*H"0 + lOCO* + 6BP0

Ami
alcot

Aznyl-
>nol.

8C^'«0« « 2C«H"0 + 6C0» + 4n'0
Hexyl-
alcohol.

Oetyl-alcohol is said to be obtained by saponifying castor-oil with potash, and dis-
tilling the resulting ricinolate of potassium with excess of the alkali at a high tempe-
rature. The ricinoHc acid is then converted into octyl-alcohol, sebate of potassium,
and free hydrogen :

QwQUQt + 2KH:0 s= C^»K) + C"H»«K*0* + 2H

Ricinolic Octyl- Sebate of

acid. alcohol. potassium.

Bonis (Compt. rend, xriii. 141). Other chemists, however, who have examined
this reaction, state that the alcohol produced by it is not octylic, but heptylic. Ac-
cording to Stadeler (J. pr. Chem. Ixxii. 241) two reactions ts^e place simultaneously,
the one giving rise to the formation of heptylic alcohol, sebate of potassium, and
hydride of methyl (marsh gas), the other to the formation of methyl-cmanthyl, an acetone
isomeric with caprylic aldehyde, CH^K), and free hydrogen ; thus :

Ci«H"0« + 2KH0 = C'H»«0 + C'»H»«KW + CH'.H

Blcinolic Heptyl- Sebate of Hydride

acid. alcohol. potassium. or methyl.

Ci«H«*0» + 2KH0 « CH'.CH'K) + C'^ff^K^O* + H*

Ricinolic ' Metbvl- Sebate of

acid. oenantByl. potassium.

According to Dachauer, on thecontraijr (Ann. Ch. Pharm. cvi. 270), the products
of the distillation are methyl-cenanthyl and octylic alcohol, the formation of this al-
cohol differing from that of methyl-oenanthyl only by the elimination of two atoms of
hydrogen instead of four. It does not appear that Stadeler actually observed the evo-
lution of marsh gas.

Cetyl-alcohol (or ethal) is obtained by decomposing spermaceti (which consists chiefly
of oetin,(^K**0^) with alkalis, palmitic acid being formed at the same time :

C«H"0« + KHO B C"H"0 + C»«H"KO»

Cetia. CetTl- Palmitate of

alcohol. potassium.

ALCOHOLS. 99

In the same manner, cezotyl-alcoliol is formed from Chinese^waz, and melissyl-
aktthoi from beea-wax.

C"H»0« + KHO = C«H«^ + C«TJ"KO«

Cbinete- CerotyU Cerotate of

wuL. alcohol. potusium.

Some of these alcohols have also been formed from the corresponding hydrocarbons
OH^, e.y. common aleohol from olefiant gas, (?K*, and trityl-alcohol from tritylene,
CH', by difisolvijig these gaseons hydrocarbons in strong sulphuric acid, and decom-
Dosiiig the resolting ethyl-solphnric or trityl-salphuric acid by distillation with water.
Methyl-^cohol has been formed from marsh-gas, CH^ by exposing that compound to
the action of chlorine in sonshine, whereby chloride of methyl is obtained, and decom-
poBiDg this body with aqueous potash (Bert he lot, Compt. rend. zIt. 916) :

CH«C1 + KHO = CH*0 + KCl

The first eight alcohols of the series are liquid at ordinary temperatures. Methylic
and ethylic uoohols are mobile watezy liquids ; the others are more or less oily, the
Tiscidity increasing with the atomic weight. Cetyl-alcohol is a solid fat: cerotylic
and m^iasylic alcohols are waxy.

Oxidising agents convert these alcohols into aldehydes, C"H'"0, or acids, OH^O^ in
each ease with elimination of one atom of water :

OH*»*K) + O « OH*»0 + H«0
and C*H«-+K) + O* - C-H^-O* + B.H)

These changes take place on exposing the alcohols to the air, especially in contact with
pbtinum-black, and more quickly on distilling them with a mixture of dilute sul-
phnric add and chromate of potassium. The alcohols are also conyerted into fatty
acids by heating them strongly in contact with soda-lime (a mixture of quick lime
with caustic soda) ; e.^, am^'l-alcohol thus treated yields valerate of sodium.

The alcohols of this senes contain one atom of hydrogen replaceable by metals or
eompoond radicles. Hany of them, when treated with potassium or sodium, give off
hydrogen, and form solid compounds containing 1 atom of the alkali-metaJ, e,ff,
etbTlate of sodium, CH^NaO. Id. this respect the alcohols partake of the nature of
adds. — The oompoonds thus formed are easily decomposed, and are not easily ob-
tained in a definite form.

On treating these potassium- or sodium-alcohols with the iodide of an alcohol-radicle,
iodide of potassium or sodium is precipitated, and an ether is formed, that is to say,
a compound deziTed from an alcohol by the substitution of an alcohol-radicle for the
banc atom of hydrogen : thus ethylate of sodium with iodide of ethyl yields ethylic
ether ((?H»)«0, and with iodide of amyl, ethyl-amyl ether, (?H».C*H".0 (p. 76),

The alcohols are also converted into ethers by the action of strong sulphuric acid
chloride of adnc, fluoride of boron, and other powerful dehydrating agents, at a certain
temperature. The ultimate change is represented by the equation :

2(o^-jo)-HK)-gg::;jo

Alcohol. Ether.

For the intermediate steps of the process see page 76. This particular change takes
place only between certain limits of temperature, e, g. for the etnerification of common
aleohol by sulphuric acid, the limits are 140^ and 160^ C. At higher temperatures, a
farther dehydration takes place, and a hydrocarbon OH^ is obtained :

i,g, common alcohol heated above 160® with strong sulphuric add, yields olefiant gas
0»H*.

With the greater number of adds, alcohols yield eomptmnd ethers ; that is to say,
■alts in which the basic hydrogen of the acid is more or leas replaced by the radicle of
the alcohol With monobasic adds, only neutral ethers are formed: thus common
ileobol heated w^ strong aeetie add yields acetate of ethyl, with elimination of
vater:

The formation of these ethers is greatly assisted by the presence of strong sulphuric
or l^rdroehloric add, to take up the water. They are commonly prepared dther by
distilling the idoohol with sulphuric add, and a salt of the other add (e,ff. acetate of
ethyl, by digfilling alcohol with sulphuric add and acetate of sodium), or by passing

H 2

100 ALCOHOLS.

hydrocUoric acid gas into an alcoholic aolntion of the acid. The former method is
applicable to the more yolatile ethers, the latter to those of higher boiling-point

With dibasic and tribasic acids, the alcohols generally form acid ethers or alcokolie
acidst that is to say, compounds in which only a portion of the basic hydrogen of the
acid is replaced by the alcohol-radide. Thus, when amyl-alcohol is mixed with buI-

C*H**) ^SO*V' )

phuric acid and the mixture kept cool, amyl-sulphurie acid, ^ f ^^* ^' C»H".H { ^

is produced:

In like manner, phosphoric acid, and amyl-alcohol yield amyl-phosphoric acid,

PO*.C*H".H».

Hydrochloric, hydrobromic, and hydiiodic acids convert the alcohols of this series
into chlorides, &c., of the alcohol-radides, with elimination of water :

^^H*l^ + ^^ " C«H«-*> a + H*0 ^

A similar transformation is effected by the chlorides, bromoides, and iodides of phos-
phorus: e,ff,

^h"{^ + pa*.a» = c»H»ci + Hci + pocp

Amyl- Penta- Chloride Oxychlo-

alcohol. chloride of of amyl. ride of

phosphoruf. phoipborua.

With the chlorides of acid radides, the alcohols form compound ethers, hydrochloric
acid being at the same time eliminated :

cf* jo + CTBPo.a - g^.'Ojo + Ha

N , > , ' > ,

Ethyl- Chloride of Bensoate

alcohol. benaoyL of eihyL

Persulphide of phosphorus transforms the alcohols of this series into mercaptans
(sulphur-alcohols) :

6C-H«»+« 0 + P«S» - 60-H«-+*S + PK)»

2. Alcohols of the form OB>0 « H 1 ^ convertible by oxidation into adds

of the form OU^-K>\

Only one term of this series is at present known, viz. : —

AUyUalcohol or Hydrate of Myl, C»H"0 - ^'g* \ 0.

This alcohol was discovered by Cahours and Hofmann in 1856. It is con-
verted by oxidising agents into aciyHc aldehyde or acrolein, CHK), and acrylic
acid, C*H^O', and moreover exhibits all the transformations of the bodies of the pre-
eedinff series (see At.t.tl). It is probable that to every acid of the series C"H^-*0"
(angeKic, terebic, oleic acid, &c^, there corresponds an alcohol of the form OHM).
These alcohols are isomeric with the aldehydes of the preceding series ; e. g, allyl-
alcohol with propionic aldehyde.

8. Alcohols of the form C»H«»-«0 «^"^'*|o. Only one alcohol of this kind

is known, viz. :

Campholf or Bomean Camphor, C'*H"0 « tt [ 0. It is a solid substance which,

when distilled with anhydrous phosphoric add, yields the hydrocarbon, CH'* a
C^'H^O— KK). It forms neutral ethers with stearic and benzoic adds.

4. Alcohols of the form OH^^-K) ■■ n [ ^» *^^ corresponding to adds of

the form OH*»-*0* Three of these alcohols are known, viz. :
Benzyl-alcohol, or Hydrate of Benzyl, C'H»0 ^^g'l ^

CumyUalcohdl, or Hydrate of Cumyl, C"H><0 «^"^**| O
Bycoeeryl^deohol^QxHydraU of aycoceryl, C»"H*0=^*"2*1^

ALCOHOLS. 101

Boayl-alcoho] vas discovered by Cannizzaro in 1863 ; cmnyl-alcoliol by Erant in 1864 ;
thcie two alcofaob are obtained by treating the corresponding aldehydes (bitter-
almand oil and cnminol) with an alcoholic solution of potasn :

2C'H«0 + KHO « C*H»0 + C'H*KO«

•" , - >^ f »x *- ^ -*

HTdrlde of B«niy|. Benzoate of

benzoyl. lUoobol. poUMium.

MoreoTer, the aldehydes themselves may be formed from acids, by distilling a mix-
tme of the caldimiHHdt of the acid irith formate of calcium, thus :

Benzoate of Formate Hydride of Carbonate

ealcium. of calcium. ofbenxoyl. ofcalclam.

Henee it appears that these alcohols ma^ be formed from the corresponding acids.

Bmz^lie and cnmylic alcohols are liqmds which volatilise without decomposition.
Thej are conyerted into aldehydes and acids by the action of oxidising agents ; they
form compound ethers when treated with a mixture of sulphuric acid and other
(njcen-aads {e.ff. acetate of bensEyl, C*H'0'.C'H\ is formed by treating benzyl-
aleohol vith a mixture of sulphuric and acetic acids), and yield the chlorides of the
coTTCaMmding radicles when treated with hydrochloric acid ; thus chloride of benzyl,
C^H'U is obtained by treating benzyl-alcohol with strong hydrochloric add.

With snlphurie acid or chloride of zinc, they yield resinous masses, which are
pobebly hydro-carbons analogous to olefiant gas: anhydrous boracic acid converts
baii]rl-alooh3l into benzyl-ether (CrH')*0. They do not appear to form conjugated
acids like ethyl-solphniic acid. By caustic potash, at high temperatures, tney are
ooDTOted into the corresponding acids and hydrides of the alcohol-radides ; e.g. :

3(CH'.H.O) = (7H«0« + 2(CH'.H) + HH)

Beuzyl-alcohol. Benxoic Hvdride of

acid. benzjl.

S^eoeexyl-alcohol was discovered bj Warren DelaRueand Hugo Miiller,in 1859
(Pkoc Baj, Soc X. 298). It exists in the form of a natural acetic ether in the exuda-
tion from an Australian plant, the Ficus nUnffinoaa, This ether is readily obtained
in beautiful ciystals, and when treated with sodium-alcohol, yields acetic add and
If eooeiylic alcohol, in feathery crystals resembling caffeine or asbestos. Treated with
nitric add, it yidds an add whidi appears to be sycocerylic acid ; and with chromic
acid, it yields a product which is probably the corresponding aldehyde.

5. Alcohols isomeric with the last, but differing from them in forming conjugated
acids with sulphuric add, phosphoric acid, &c., and in not being converted into acids
and aldehydes by the action of oxidising agents. Two of these alcohols are known,
m:

Htnfi-aleohol, orEydraU of Phenyl, CWI^O = ^"^ | O
Cn^fl-akohol, otHydraU of Creayl, CHK) « ^^[o.

The farmer was identified as an alcohol by Laurent^, in 1841 ; the latter was disoovered
liy Williamson and FairUe, in 1864.

Both of these compoundis occur among the ^xroducts of the destructive distillation of
ooal, and are seiMzated by fractional distillation. Phenyl-alcohol is also produced by
the destructive distillation of salicylic acid :

CH«0» = C^»0 + C0»

I%coyl-alcohol is solid and crystalline at ordinary temperatures, mdts at 36^, and
distils without decomposition at about 186^. Cresyl-alcohol is liquid at ordinary
temnentures.

lliese alcohols are easily decomposed by potasdnm and sodium, like common alco-
hols, hydrogen being evolved, and compounds formed analogous to ethylate of potas-
simn. They exhibit more dedded add characters than any of the preceding alcohols :
phenyl-alcohol indeed is sometimes called phenic or carbolic acid : it forms a series of
nlti, called phenates or carbolates, containing 1 at. metal in place of the basic hydrogen.
These alcohols are not converted into simple ethers or hydrocarbons by heating with
solphunc add. Strong nitric add converts them into nitro-adds, e, g, phenyl-iiloohol
into tiinitzoeaibolic or picric add, C«H*(NO>)*0.

102 ALCOHOLS.

With pentachloride of phoflphoms, thej yield a chloride and a phosphate of the
radicle together with hydrochloric acid : e.g.

4(C«H».H.O) + PC1«.C1» - PO*(C*H»)« + C«H»C1 + iHQ

Hydrate of Phosphate of Chloride

phenyl. phenyl. of phenyl.

With the chlorides of the acid radides, they form compound ethers, thus :

C^».H.O + C'H*0.C1 « (7H»0«.C*H» + HCl

Hydrate of Chloride of Benioate of

pbenyU benzoyl. phenyl.

6. Alcohols of the form C"H*»-»0 = ^"^^^Jo. Two only of these bodies are
known, yiz. :

Cinnamio alcohol^ Hydrate of Oinnamyl, or Styrone, C*H**0 « h(^

Choleaterin C»H"0 - ^ ^^fo

Styrone is obtained b^ heating styradn (cinnamate of cinnamyl), with caustic alkalis ;
cholesterin is found in the bue and other products of the animal economy. Styrone
is converted by oxidising agents into cinnamic aldehyde, C^HK), and cinnamic add,
CH'O', and forms with fuming sulphuric acid a coig'ugated acid, the barium-salt of
which is soluble in water. Cholesterin heated with strong sulphuric acid gives i^
water and forms a resinous hydrocarbon, C^^ (Zwenger, Ann. Ch. Pharm. Ixv.
6). Heated to 200^, with acetic, butyric, benzoic, and stearic acids, it forms com-
pound ethers, with elimination of water, thus :

Stearic Cholesterin. Stearate of

acid. cholesterin.

7. Saliffenin, CHK)*, aa alcohol of the salicyl-series, and Anuic alcohol, O'H'H)*,
produced by the action of alcoholic potash on hydride of anisyl, OH'O^H, are
probably monatomic ; if so, they must contain oxygen-radicles, their rational formulae

being ^'^gjo and ^^'^hI^' ^^* ^^^ ^^^ *^ ^ diatomic alcohols, ^*|o«
and n> [ ^* Their reactions are not suffidently known to decide the question.
B. IMatomlo Alooliols, or Olyeols. C»H>^sO' « ^^^'^^| O*. These com-

"ITS

pounds, discovered by Wurtz, are derived from a double molecule of water, n-sO*, in whidi

half the hydrogen is replaced by a diatomic radide OB>. Four of these have been

obtained, viz. Ethylene^lyool, or HydraU of Ethylene, C«HK)« = ^^'^^[o',iVopy-

lene-glycol, CHH)*, ButyUne-glycol, C*H'*0*, and Amylme-glycol, C»H»«0". The
simme name glycol is espedaUy applied to the first of these, just as the term alco-
hol IS espedaliy applied to hydrate of ethyl, the most important of the monatomic al-
cohols.

Glycol is obtained by treating iodide of ethylene with acetate of silver, whereby di-
acetate of ethylene is formed :

Iodide of 8 at. acetate of Diaoetate of

ethylene. silver. ethylene.

and heating the distilled diacetate of ejthylene with potash, whereby it is decom-
posed, like other compound ethers, yidding acetate of potassium and hydrate of
ethylene :

(C^.).jO. . 2(KH0) - <^:j0. . (C^^IJo.

It was discovered by Wurtz in 1856. The other bodies of the series are obtained by
similar processes. They are oily liquids, which distil without decomposition. They
contain two atoms of basic hydrogen, one or both of which may be replaced by metds
or other radides.
Glycol treated with sodium yidds monoaodic glycol, C^'(NaH)0^ and this com-

ALCOHOLS. 103

pound, ibsed irith excess of sodium, yields disodic glycol^ C*H^NaK)'. By treating
mooosodic glycol with iodide of ethyl, the prodact with potaasium, and this piquet
a^sain with iodide of ethyl, the componnds C»H«(C«H*.H)0«, C*H*(C?H».K)0*, and
C^H^CrH*)*©*, are sacoesaiTely obtained. The la?t ia isomeric with acetal, but not
identical with it (p. 3^ inasmuch as it boils at a temperature 20^ below that compound.
Dehydrating agents^ such as sulphuric acid and chloride of zinc, do not act upon the
glycols in the same manner as upon the corresponding monatomic alcohols. Ethyl-
alcohol, (XS\H.O, acted upon by sulphuric acid, or chloride of zinc, at certain tempe-
ratures; is conyerted into ether, (CH*)K), a second atom of ethyl being introduced in
j^ace of the remaining hydrogen. If glycol were acted on by these reagents in the
same manner, the result would be a glycolic ether containing (C'H*)'0*. Instead of
this, the change which takes place is a simple abstraction of water, and the resulting
compoond is aidehyde, 0*M*0, a body of isomeric composition, but only half the atomic
wdght:

C«H«0» - HK) = C«H<0.

Similar results are obtained with the other glycols. The aldehydes may therefore
be regarded as the ethers of the diatomic alcohols ; and their mode of ibrmation from
these ala>hols difiers from the etherification of the monatomic alcohols in the same
manner as the oonyersion of dibasic acids into anhydrides difiers from that of mono-
basic acids, — ^the latter being converted into anhydrides by duplication of the radicle :
e.ff. acetic acid « OH*O.H.O ; acetic anhydride » (OH'0)K), whereas dibasic acids
pass to the state of anhydrides by simple abstraction of water, e.g. SO^Hf — H*0 » SO*.
(Wurtz, Compt. rend. xlyiL 346.)

By treating diatomic akohols, first with hydrochloric acid and afterwards with
potash, oompounds are obtained isomeric with the aldehydes, and resembling them in
some €»F their properties, but difiering in others ; thus, ethylene-glycol, heated in a
sealed tnbe with hydrochloric acid, yields monochlorkydric glycol, CHH^O, a compound
intermediate between ^col and chloride of ethylene, CH^CP, and formed frx>m glycol
by the snbatitation of CI for 1 atom of peroxide of hydrogen :

(?H*.H«0» + HCl = C^H^.HO.Cl + H^O;

and this compound, treated with potash, yields oxide of ethylene, a body isomeric with
acetic aldehii^e:

0"H*.HO.a + KBO « CH^O + H^O + KCl.

This oxide of ethylene resembles aldehyde in being miscible with water, and in form-
ing a crjTBtalline compound with acid sulphite of sodium ; but difiers from it by boiling
at a lower temperature, and by not forming a crystalline compound with am-
monia. Sinular results are obtained with propylene-glycol. (Wurtz, Compt. rend.
xlriiL 100.)

The glycols corresponding to the other series of monatomic alcohols, have not yet
been obtained ; but several diatomic compound ethers containing benzylene, C'H*, have
been produced, viz. the acetate, valerate, and benzoate, CH*. (C^*0)'.0*, &c. ; the
metfajlate, ethylate, and amylate, CH«.(CH")*.0», &c; the sulphate, SO*.C'H«, and
the saecinate, (rE:C*K*0*.0\ The diatomic alcohol, CTBL'.H^O^, corresponding to
those compound ethers, has notyet been obtained, not being produced when the ethers
are decomposed by alkalis. (W. Wicke, Ann. Ch. Phaim. cii 363.)

C. THatonlo Alooliols» or Olyoertns. The general formula of these compounds
m [ O*, the radicle OH*»- ' being equivalent to three atoms of hydrogen. One

term of the series haB long been known, viz. ordinary glyjeerin, C*HH>* « H"[^**

the sweet oily liquid obtained in the saponification of fats. It was first shown to oe a
tziatomic alcohol by Bert helot, in 1853. (Compt rend. xxxviL 398.)

The neutral fats of the animal body, stearin, palmitin, olein, &c., consist of glycerin,
in whidi three atoms of hydrogen are replaced by acid radicles; and by heating
^yoerin with adds in different proportions, a large number of compounds may be
formal, in which L {, or the whole of the replaceable hydrogen is thus replaced,
the formation of these compounds being accompanied by the elimination of 1, 2,
or 3 atoms of water. Thus, with stearic acid, C"H"0^ the following compounds
are obtained:

Honostearin - C«H«0* = C^>0» + C'^H-O* - H«0 - h1^^mo|o«.
Distcarin - C*H»0» « C»H«0« + 2C»H«0« - 2H»0 - h.(cS«0)»1^*

5SSf°.te«riB)t - ^^"•^ " ^^^ + ^C'^H"^' - »^'- (i^')'!<^'-

H 4

104

ALCOHOLS.

Freciflely similaF actions take place on heating glycerin with hydrochloric, hydio-
bromic, or hydriodic acid ; but to refer the resulting compounds to the same type, it
is best to write the formula of glycerin thus : C'H*(HO)', representing it as a compound
of glyceiyl with 3 at peroxide of hydrogen : then the compounds just mentioned may
be represented as glycerin in which 1, 2, or 3 at peroxide of hydrogen are replaced
by CI, Br, I, &c Thus:

Monochlorhydrin - C^'aO» « C»HK)" + HCl - IPO « C»H»Cl(HO/

Bichlorhydrin « C»H«C1K) = C»H"0» + 2HC1 - 2HH) « C^»C1«(H0)

Tricblorhydrin « C^KKH* « C»H«0' + 3HC1 - 3HK)

Biomhydrodichlorhydrin - C«H»Cl»Br« C»H"0» + 2HC1 + HBr - 3H»0.

The chlorhydrins and bromhydrins are likewise produced by treating glycerin with
either of the bromides or chlorides of phosphorus. (See Gxtcerin.)

By treating glycerin with the chloride of an acid radicle, or by passing hydrochloric
acid gas into a solution of glycerin in the corresponding acid, compounds are formed
which may be regarded as glycerin, in which the peroxide of hydrogen is replaced
partly by chlorine and partly by the peroxide of the acid radicle ; thus with acetic acid
[Ac - C^H'O] :

Acetochlorhydrin » C*H»aO« = C»H»0« + C«H*0» +
Diacetochlorhydrin « Cff »C10« « C«H*0» +
Acetodichlorhydrin « C*H«aK)« - C«H»0» +

HCl - 2HK) «

C»H»Cl(Ac0XH0).
2C"H*0« + HCl - 3H«0 «

C»H».a(AcO)«
C*H*0« + 2Ha - 3H»0 «

C«H».Cl«AcO.

(For fiirther details, see Acetins, p. 25.)

All these compounds, when heated with caustic alkalis, or with metallic oxides and
water, reproduce the acid and the glycerin ; thus stearin heated with caustic potash,
yields glycerin and stoarate of potassium :

(0^^).|0. . 8KH0 . C^ljO. . z(0-^'\0)

Glycerin may also be formed synthetically in a similar manner to glycol* "riz. Irjr
heating tribromhydrin, C*H*Br", with acetate of silver, whereby triacetin, U"H'AcK)* is
formed, and heating this compound with solution of caustic baiyta. The other
gfycerins have not yet been obtained in the free state, but the acetate of ethyl-glyeerin
(U*H»)'"Ac*0* appears to be obtained, together with glycol, by the action of iodide of
ethylene on acetate of silver.

D. Alooliols not inolnded la ajiij of tbo preeodiBff groupo. — Berthelot
has shown that a considerable number of substances, not usually classed as alcohols,
nevertheless possess one essential character of those bodies, viz. that they unit4> with
acids, producing neutral compounds, the formation of which is attended with elimina-
tion of water; and these compounds, when heated with alkalis, reproduce the sub-
stances from which the^ have been formed. The bodies in question are chiefly of
a saccharine nature, viz. Mannite, C*H*20*.H*0, the sugar of manna; Dtdcin,

Phycite^ C*H"0*, a sugar obtained from certain lichens, and from the Protococctts tni/-
garis, — Orcin, C'H'O', a sweet crystalline substance, existing in the lichens which
yield archil and litmus ; Trehalose, C«H^»0», also a kind of sugar ; Glucose, C*H"0«,
and Meconin, C**H><^0\ an acrid crystallisable substance, obtained from opium. The
following are examples of the compounds formed :

C^«0» + 2C«H*0« - 2H«0 a C»H'«0»

Mannlte. Acetic acid.

C^»K>» + 4C>»H»0« - 2HK) « C^H»«0"
Mannlta Stearic acid.

C«H»0*
Maouite.

+ 6C"H*0» -
Stearic acid.

6BP0 « C"*H"«0"

Fhjcite.

+ 2C»H«0« -
Benzoic acid.

2HK) - C«»H«0»

(?)

C«H»0«
Pbjrcite.

+ 6C'H'0» -
Benioic ac*d.

6H«0 = C"H*0"

(?)

C^»K)«

Glucose.

+ 2C»«H"0« -
Stearic acid.

3H«0 = C**WK>^

C"H»»0*
Moconln.

+ 2C"H«»0» -
Stearic add.

2H«0 « C«H»0«.

ALDEHYDE. 105

The eompoands fiinned by all these bodies, exceptiiiff the last two, with acidB, readily
jield ihe original saccharine substance and the acid. The compounds formed with
gineose are not very definite, and not easily decomposed ; but when treated with dilute
solphnric acid, thej yield the original acid and a fermentable sugar, which reduces
copper salts. (Berthelot, Compt. rend. zIL 462; zlTii. 262.)

AZASBTBB. C*H*0 « C«HK).H. [or Cfi^O* = dPO.HO]. Acetic aldehyde,
Hjfdride cf Acetyl (Gm. yiii 274; xiii. 437; Gerh. i. 658). — A volatile liquid
produced, by the oxidation and destructire distillation of alcohol and other oiganic
eompovnds. It was first obtained in an impure state by Dobereiner, who called it
IjUfkt axyyen ether, and waa afterwards prepared pure and thoroughly examined by
Liebig (Ann. Ch. Pharm. xir. 133 ; xxxvi 376). The name aldehyde ia an abbrevia-
tion of alcohol dehydroyenatunif inaamuch as the compound may be r^arded as alcohol
depriTed of two atoms of hydrogen.

Formaium^ — 1. In the oxidation of alcohol, either by slow combustion in contact
with platumm-black, chromic oxide, &c, or by the action of chromic acid, nitric acid,
chlorine water, or a mixture of sulphuric acid and.peroxide of manganese (see Axconoi.,
pi 74). — 2. Wben the yapour of alcohol or ether is passed through a tube heated
to dull redness ; also in tne slow combustion of ether. — 3. In the decomposition of
acetate of ethyl, and probably also of other ethylic ethers, by a mixture of sulphuric
add and acid chroma te of potassium. — 4. By heating acetal with glacial acetic acid to
between 150^ and 200^ G. for two days. Acetic ether and alcohol are formed at the
same time, and on distilling the mixture, aldehyde passes over below 60^ :

Acetal. Acetic Aldehyde. Acetic Alcohol,

acid. ether.

abo by >»Aft*ing acetal with acetic anhydride :

C^»K)« + C^H'K)* « C*H*0 + 2C*H»'0».

A fewdnps of liquid are also obtained boiling above 150^, and probably consisting of
a compoond of aldehyde with acetic anhymide (Beilstein, Gompt. rend, xlviii.
1121). — 5. By heating ethyl-sulphuric aeid or one of its salts with a mixture of sul-
phune acid and peroxide of manganese. This formation of aldehyde is said to take
place under circumstances which altogether preclude any previous formation of alcohol
(Jacquemin and Liis-Bodard, rlnstitut, 1867, p. 407). — 6. When hemp-oil is
passed through a gun-barrel heated to low redness, a liquid is formed containing a
large quantity of aldehyde, together with alhehydic or lampic acid (Hess). — 7. By
the dry distillation of lactic acid, lactic anhydride, and lactates with weak bases, such
as lactate of copper, carbonic oxide being given off at the same time :

CR'H)* = 2C"H*0 + 2C0 + 2H*0.

— , — ' " — , — •'

Lactic Aldehyde,

acid.

8. Lactic acid and the lactates also yield considerable quantities of aldehyde when dis-
tilled with sulphuric acid and peroxide of manganese (Stadeler, Ann. Gh. Pharm.
Ittix. 333). — 9. In the decomposition of animal albumin, fibrin, casein, and gelatin by
a mixture of sulphuric add and peroxide of manganese, or bichromate of potassium
(Ouckelberger), also of v^table fibrin by sulphuric acid and peroxide of manganese
(Keller). — 10. By the dry distillation of a mixture of acetate and formate of caldum
in equal numbers <^ atoms (Li mpri ch t. See Aldbhtdbs, p. 1 1 1 ; also Acbtonbs, p. 31 ).

C»H«GaO« + CHGaO« = CWO + CG»Ga«.

Acetate of Formate of Aldehyde. Carbonate

calcium.' calcium. of calcium.

I^'eparaium. — 1. Two pts. of 80 per cent alcohol are mixed with 3 pts. oil of vitriol
aod 2 pts. water, and distilled into a receiver kept at a vezy low temperature. The
mixture is gently heated till it begins to froth slightly, and the distillation is interrupted
as soon as the liquid which passes over begins to redden litmus, which it does when
the distillate amounts to 3 pts. The distillate, consisting of aldehyde, alcohol, &c., is
mixed with an equal weight of chloride of calcium, and distilled (the receiver being
constantly kept veiy cold), till 11 pt. has passed over, and this distillate is again
rectified with an equal weight of cnloride of caldum till f pt. has passed over. This
last portion is anhydrous, but contains alcohol and certain compound ethers as well as
aldehyde. To punfy it^ 1 vol. is mixed with 2 vol. ether, the mixture surrounded with
oold water, and dry ammoniacal gas passed into it to saturation ; the gas is absorbed
npidly and with great evolution of heat, and the aldehyde separates out in crystals of
aldehyde-anunonia. These crystals are washed three times with absolute ether and
dried as above. (Liebig.)

103 ALDEHYDE.

2. A mixture of 1 pt. 80 per cent, alcohol and 2 pts. wat«r ia saturated with
chlorine gas (being kept cool all the while), and the liquid distilled, as soon as it has
lost the odour ofchlonne, till ^ has passed over. That which distils oyer afterwards
is alcohol, which may be collected in a separate receiver and again treated with chlorine
as above. The first distillate is again freed from water by repeated distillation so far
as to admit of its being saturated with ammonia as aboye, and yields a very large
crop of crystals. (Liebig.)

3. One part of alcohol of sp. gr. 0*842 and 1 pt of bichromate of potassium are in-
troduced mto a capacious tubu^ted retort and 1| pt. oil of vitriol admitted by drops
through the tubulus. The heat evolved by the chemical action which ensues is suffi-
cient to begin the distillation, but towards the end, heat must be applied from without.
A large quantity of carbonic acid gas is evolved, and the aldehyde condenses in the
well cooled receiver, contaminated with only a small quantity of acetic acid and other
substances, so that the distillate may be immediately mixed with ether, and ammoniacal
gas passed through it as above (W. and R Bodgers, J. pr. Chem. xl. 248). The
modes of formation 5, 6, and 8, above given, may aUo be advantageously used for the
preparation of aldehyde. <

To obtain the pure anhydrous aldehyde from the aldehyde-ammonia formed by •

either of these processes, a solution of 2 pts. of the aldehyde-ammonia in 2 pts. water,
IB distOIed in a water-bath at a gentle but increasing heat, with a mixture of 3 pts.
sulphuric acid and 4 pts. water, the distillation being interrupted as soon as the water
in the bath begins to boil, and the receiver kept as cold as possible, The hydrated
aldehyde which passes over is dried by contact with coarse lumps of chloride of cal-
cium in a well aosed vessel, and then rectified in a water^bath, at a temperature not
exceeding 30^.

Properties. — Aldehyde is a thin, transparent^ colourless liquid, having a pungent
suffocating odour. Its specific gravity is 0-80002 at 0^ (Kopp); 0*80561 at 0^
(Pierre). It boils at 20*8^ when the barometer stands at 760 mm. fKopp) ; at
22^, with ihe barometer at 758*2 mm (Pierre). Vapour-density 1*532 (Liebig) ; (by
calculation, 1*520, for a condensation to 2 vol.) It does not redden Utmus, even when
it is dissolved in water or alcohol.

Aldehyde may be regarded either as the hydride of acetyl^ C^H'O.H, or as the hv'

drate or hydrated oxide of vinyl^ H [^' I^^ cb^°^cal ^^ctions may for the most

part be explained equally well on either hypothesis; but according to the recent
observations and calculations of Kopp, the formula C^*O.H, is most in accordance
with the observed atomic volume of aldehyde, which is between 56*0 and 56*9, the
calculated atomic volume being 56*2, as deduced from the first formula, and 51*8 as
deduced from the second. (See Atomic Volume : also Graham's Chemistry, 2nd Ed.
vol. ii. p. 581.) — ^Aldehyde is isomeric, but not identical, with the oxide of ethylene,
C*H*.0, recently discovered by Wurtz.

Aldehyde mixes in all proportions with water, alcohol, and ether. A mixture of
1 pt. aldehyde and 3 pts. ' water boils at 37°. Chloride of calcium added to the
aqueous solution separates the aldehyde, which then rises to the surface.

Aldehyde dissolves sulphur and phosphorus, also iodine, forming a brown solution.

D17 sulphurous acid gas passed into anhydrous aldehyde surrounded with cold
water, is rapidly absorbed, 11 pts. of aldehyde absorbing 9 pts. of the gas, with
increase of volume. The absorption-coefficient of aldehyde for sulphurous acid gas is
1*4 times as great as for alcohol, and 7 times as great as for water. (Geuther and
Cartmell, Ajon. Ch. Pharm. cxi. 17.) •■

Decompositions. — 1. Aldehyde is very inflammable, and bums with a blue flame. —
2. When kept in close vessels, it is often converted into a less volatile liquid, or into
two crystalline bodies, which are isomeric modifications of aldehyde (p. 109). — 3. In Tea-
sels containing air, it absorbs oxygen, and is converted into acetic acid ; the action is
greatly accelerated by the presence of platinum black. — 4. Chlorine-water and nitric
add also convert aldehyde into acetic acid. — 5. By strong sulphuric acid, it is thickened
and blackened, also by phosphoric anhydride. — 6. When an aqueous or alcoholic
solution of aldehyde is heated with potash, it becomes yellowish and turbid, and a
red-brown resinous mass, the resin of aldehyde, separates on the surface, the liquid at
the same time emitting a spirituous and disagreeably pungent odour. The solution is
afterwards found to contain formats and acetate of potassium. This is the most
characteristic reaction of aldehyde. — 7. When vapour of aldehyde is passed over red-
hot potash-lime, acetate of potassium is formed and hydrogen evolved :

C*H*0 + KHO « C«H»KO« + 2H.

8. Potassium Tor sodium) acts on aldehyde in the same manner as on alcohol, hydro-
gen being evolved and aldehydate of potassium, C'BPKO, produced. — ^9. When an

ALDEHYDE. 107

•qveoiis eolation of aldehyde is heated with oxide or nitrate of silver^ mixed with s
imdl quantity of a$nmonia^ tlie silTer is reduced, forming a beautiful specular coating
on the side of tlie vessel, and acetate of silver is formed in the solution. This reaction
■ffiods an extremely delicate test for aldehyde. — 10. Chlorine gas in contact with alde-
hyde, botli beiiu; dry, decomposes part of the aldehyde^ forming chloride of acet^ which
then unites with the nndeoomposed aldehyde, forming the compound, C'HH}.&H'0C1.
— II. When diy hydrochloric acid gas is passed into anhydrous aldehyde surrounded
by a freezing mixture, the gas is absorbed and the liquid separates mto two layers,
the lower consisting of water saturated with hydrochloric acid, and the upper of oxy-
chloride of eihyUdcne, C<HK3K) (A. Lieben, Compt lend. xlyi 662) :

2C?H*0 + 2HC1 « (ySHSlH) + WO.

Aoecoding to Genther and Cartmell (Ann. Ch. Fharm. crii. 13 ; Froc Roy. Soc
X. 110) the first product of the action is the body, C^"G1H)^ which, when gently
heated in an atmosphere of carbonic add, splits up into aldehyde, CH^O, and
C*HK]3*0. The compound CH'Kn^K)^ may be ri^garded as a triple molecule of alde-
hyde ((XHTK)*), haying one atom O replaced by Cu^. — 12. Aldehyde mixed with twice
its bulk of absolute alcohol, and saturated in the cold with hydrochloric acid gas,
yields the compound OH*C10, which, when treated with ethylate of sodium, forms
SfCetal (p. 3). ---13. "^th pcntachloride of phosphorus^ aldehyde yields chloride of
ethylidene,,(?H*Cl*, and with pentabromide of phosphorus it yields bromide of ethyli-
dene, U*ll^i*, which is conyerted by ethylate of sodium into acetal (p. 4). — 14. Chloro-
carbonic oxide (phoseene gas) conyerts aldehyde into chloride of vinyl, CH'Cl, with
evolution of hydrochloric add and carbonic anhydride. (Harnitz Harnitzky, Ann.
Ch. Fhaxm. cxi 192.)

c«H*o + coa« a. c*H»ci + Ha + co«.

15. Hydriodic acid gas appears to act upon aldehyde in the same manner as hydro-
chloric add, but the product is very unstable. — 16. When aqueous aldehyde is satu-
rated with hydrosulphuric acid gas, a visdd oil is formed, consisting of hydrostd-
fhaU of aoetyl-mercaptan: C^'H^'S » SH*6C<H«a On treating this oil with strong
nydroddorie or sulphuric add, hydrosulphuric add escapes, and a white crystalline
mass remains, consisting of acetyl-^ncrcaptan, CH^S, a compound related to aldehyde,
in the same manner as ethvl-mercaptan, CH^S, to aloohoL — 17. (hfanic acid vapour
evolved from cyannric ada is quietly absorbed by anhydrous aldehyde at 0°; but
even at ordinaiy temperatures the mixture becomes heated, gives off carbonic anhydride,
and ultimately froths up and solidifies into a mass consisting of trigenic acid, C^H^NK)',
together with small quantities of cyamelide, aldehyde-ammonia, and other products
(Liebig and Wohler) ;

C*H*0 + 3CNH0 = C*ffNH)» + C0«

AumHTBAiBS. — Aldehyde may be regarded as a monobasic add, inasmuch as it
contains one atom of hydrogen replac^ble by metals. Thus, when potassium is
gently heated with aldehyde, hydrogen is evolved, and aldehydate of potassium,
CH'KO, produced : and oy evaporation in vacuo this salt may be obtained in the
solid state. — Aldehydate of silver, CH'AgO, is produced when oxide of silver is
heated with aldehyde and ammonia. The most important of these salts is the am-
monimn-salt :

Aldehydate of Ammonium, AldehydcTammonia, Acetyl-ammonium^ O^H^O.NH* a
<?H»0 JTH*, or Oxide of Vinyl and Ammonium, C«BP.NH*.0. — Ammoniacal gas
passed into pure aldehyde combines with it, giving off heat, and forming a white
oystalline mass. If the aldehyde be previoiuly mixed with ether, the compound
separates in distinct crystals; the finest are obtained by mixing a concentrated
akoholic solution of aldehyde-ammonia with ether (Liebig). — The crystals are acute
rfaovnbohedions with terminal edges of about 85^, often truncated with the faces of
ancvther riiombohedron (G-. Rose) ; they are transparent, colourless, shining, stronsly
refractive, of tiie hardness of common sugar, and veiy friable. The compound melts
between 70^ and 80° C, and distils unaltered at 100°. In the state of vapour or in
aqueous solution, it reddens turmeric paper. Its odour is ammoniacal, but has like-
wise the character of tuipentine (Liebig). — ^It dissolves veiy easily in water, less
easily in alcohol and ether.

Aldehyde-ammonia is veiy inflammable. In contact with the air, especially if also
exposed to light, it becomes yellow, and acquires an odour resembling that of burnt
animal substances. By distillation it may again be obtained in the colourless state,
and leaves a brown rcddue, which is soluble in water, and contains acetate of am-
monium and another ammoniacal salt Even the weaker acids, such as acetic acid,
separate the aldehyde from the compound. Sulphuric acid and potash act upon it in

108 ALDEHYDR

the Mine T«*tw»^ u upon aldebyde. Its aqneons solntiafii, digerted with oxide of
silver, redaces part of Uiu oxide and diMolres the rest, forming aldehydate and acetate
of tiller mixed with ammonia, from which the oxide of silver is precipitated by baryta-
water, and reduced when the liquid is heated, while acetate of boriom remains in
solution.

Aldeh jde-ammonia treated with hydroenlphoric add yidds tkialdine, C*H"N9 :

3(C«HK).NH*) + 3BPS = C«H»*NS» + (NH*)«S + 3H«0.

Similarly, with hydioselenie add, it yields seUruddine, C^^^Se*. With bisulphide
of carbon it forms carbotkUddine :

2(C«H»0.NH*) + C8» « C»H»«3rS« + 2H«0

s— ., > , '

AUebjrde. Cvbo-

CDinoDla. tliialdioe.

Aldehyde-ammonia heated with hydrocyanic and hydrochloric adds yields alanine: 1

C»H«O.NH» + CNH + HK) + Ha « CBTSO* + NH*CL ]

>-' — , ^ ' — . — ' * •

Aldehyde- Hydro- Alanine. ,

iimiDonia. cyanic

add.

But when a mixture of aldehyde-ammonia and hydrocyanic add, with snffident hydro-
chloric add to give it a distinct add reaction, is left to itself for some time, in a doeed
vessel, espedal^ in sunshine, colourless needle-shaped crystals are formed, consisting
of hydrocyaruUdine, (?H**N* :

8(C«H*0.NH») + 3CNH + 2HC1 = O^VSi* + 2NHH:J1 + 3H*0.

Aldehyde-ammonia heated in a sealed tube to 120° G. is decomposed, and yields two
layers or liquid, the upper consisting chiefly of aqueous ammonia, with small quanti-
ties of other volatile bases, while the lower, which remains behind on Hiatilling at
200°, contains a substance which has the composition C**H**NO, and mav be regarded
as an aldekydate of tetravinylium : s CH'O.N(CH')\ Its formation is represented
by the equation :

6(C*H»0.NH^) - C»»H»*NO + 4NH» + 4HK).

By treating this compound with baryta-water, the group (>Jtl"0 is replaced by HO.
and hydrate of tetravinylium is formed.

C*HK).N(C«H»)* + BaHO = C*H«O.Ba + N(C«H»)*.H.O.

(Babo, J. pr. Chem. Ixxii. 88 ; Chem. Gaz. 1858, 136.)

Concentrated aqueous solutions of aldehyde-ammonia and nitrate of silver yield,
when mixed, a fine-grained white predpitate, probably consisting of NO'Ag.
2(C*H*0.NH*). It dissolves very sparingly in alcohol, easily in water.

BulphiU of Aldehyde-ammonia, or Stdphite of Vinyl-ammonium, C*H"^NH*)O.SO* —
(C'H'.NH*).SO'. — Sulphurous add gas passed into a solution of aldehyae-ammonia in
absolute alcohol is rapidly absorbed ; and if the liquid be kept cool, sulphite of alde-
hyde-ammonia is deposited in small white prisms, which may be washed with alcohol
and dried in vacuo. This compound is isomeric with taurin, CH'NO'S — a substance
produced by the metamorphosis of a sulphur-add contained in the bile — ^but possesses
very different properties. It is soluble in water and in aqueous alcohol, very
sparingly in absolute alcohoL The crystals decompose slowly in the air at ordinary
temperatures, turn brown and lose weight at 100° and are completely decomposed at
higher temperatures, leaving a spongy carbonaceous residue. Adds decompose them,
liberating aldehyde and sulphurous anhydride. When strongly heated with potash-
lime, they give off ethylamine (Qossmann, Ann. Ch. Phann. xd. 122), or rather
perhaps mmethylamine :

C«H".NH*.SO» + KHO « C«H^ + SO*.HK.

CoKPouin) OF Aldbhtdb wtth Acbtic Anhtdridb, C*H'*0*=C*H*0*.C*H*0. —
When 1 at. acetic anhydride and 1 at., pure aldehyde are heated together in a sealed
tube to 180° C. for about 12 hours, they unite and form a liquid compound which may be
freed firom unaltered aldehyde and acetic anhydride by fractional distillation, further
purified by washing the portion which passes over above 140° with hot water, and dehj-
orated over chloride of calcium. It then boils at 168°. It has an alliaceous odour and
slight acid reaction, probably arising firom decomposition during distillation. Heated
with hydrate of potassium, it yields acetate of potassium, giving off the peculiar odour of
aldehyde when similarly treated. This reaction diHtinguishes the compound from Wuitz'a
acetate of ethylene (acetate of glycol), C«H*(C«H»0)«.0» with which it is isomeric: for
that compound heated with caustic alkalis, yields hydrate of ethylene (glycol), with-
out aoy odour of aldehyde. (Gent her, Ann. Ch. Pharm. cvi. 249.)

Aldehyde appears to form similar compounds with benzoic and succinic anhydrides.

ALDEHYDE. 109

GOMPOUND OF AxJiVETDE IHTH ChLORIDB OF ACSTIL, C*HH710*«C*H*0.C'B[*0CL

—Chloride of acetyl and aldehyde heated together to 100^ for three hours in a
•eakd tabe, iinit€ and form a liquid which diatils completely between 90^ and 140° C.
and yields bj fractional distillation a considerable (quantity of liquid, boiling between
120° and 124°. This liquid is lighter than water ; is yeiy slowly decomposed by cold
water, more quickly by hot water ; and dissolyes easily in dilute potash, forming
ehbride and acetate of potassium, and yielding free aldehyde which is partly i«sinisea
by the potash. Moist oxide of silyer also decomposes it, forming chloride and acetate
of nher. (Maxwell Simpson, Compt.-rend. xlvii. 174.) '

The same compound is pzoduced, according to Wurtz (Ann. Ch. Phys. [3] xliy. 68),
t<^gether with chloride of acetyl, by introducing perfectly diy aldehyde into a large
Tcssel filled with dry chlorine. Its formation is due to the union of the chloride of
acetyl first produced with the remaining aldehyde (compare p. 106). Wurtz, how-
erer, regaids it as a double molecule of aldehyde (C*H"0'), having 1 at H replaced by
ehbrine.

Modifications of Aldbhtdb. — ^Aldehyde ts susceptible of four isomeric modiflca-
tioDi^ two liquid and two solid.

a, Idqmd nuH^fications. — 1. Pure aldehyde sealed up in a tube changes in the
eonree of a few weeks into a liquid, which has a pleasant ethereal odour, boils at about
81°, and do longer forms a resin with potash ; it may be exposed to the air without
ozidiriiig, and floats on water without mixing. (L i e b i g )

2. Pore aldehyde mixed with about half its bulk of water and a trace of sulphuric
or nitric add, and cooled to 0° C, changes into a liquid which is no longer miscible with
water, and after being purified by agitation with water, and rectification over chlo-
ride of caldum, boils at 125°. It has a peculiar aromatic burning taste, and is
aokble in alcohol and ether, sparingly also in water. Its vapour-density is 4*683,
which for a condensation to 2 volumes, corresponds to the formula C*H*K)'. When
left to itself or in contact with water, it readily changes into an acid, and then becomes
miscible with water ; occasionally also crystahi separate from it at the same time.
When heated with a small quantity of sulphuric or nitric acid, it is converted into
ordinaiy aldehyde. (Weidenbusch, Ann. Ch. Pharm. Ixvi. 166.)

b. Solid modifications, — 1. Solid and fusible Maldekyde, — Anhydrous aldehyde, en-
dosed in a tube, together with pieces of chloride of calcium, for two months in winter,
yielded long ti^nsparent prisms, which, howerer, disappeared again after a fortnight,
■0 eom^etdy that not a trace of them could be perceived in the liquid. — These crys-
tals max at -i- 2° C, forming a liquid which solidifies at 0°, and boils at 94°, giving off
a vapour whose density is 4 '61 67. In the fused state, this substance has an ethereal
odour ; more agreeable and less pungent than that of aldehyde ; its taste is some-
what burning. Its bums with a blue flame ; its vapour passed through a red-hot
tabe yields a combustible gaseous mixture, and a small quantity of a Hquid having
an empyreumatic oc|pur. Oil of vitriol blackens the crystals slowly in the cold, imme-
diately when heated. The ciyst«lB may be heated with potash-ley for some time with-
out becoming coloured^ and solidify again on the surface as the liquid cools. When
heated with aqueous nitrate of silver, th^ throw down the silver in the form of a
grey powder, not as a specular coating. When dissolved in ether, they do not absorb
ammoniacal gas but remain unaltered. (Fehling, Ann. Ch. Pharm. xxvii. 319.)

Oeuther and Cartmell (Ann. Ch. Pharm. cxi. 16) have obtained a similar modi-
tion, by saturating common iddehyde with sulphurous add gas, dissolving the result-
ing liquid in water, saturating the acid with chalk, distiUiiig, and treating the dis-
tillate with potash, which separates the remaining common aldehyde in the resinous
fonn, and leaves the modified aldehyde in the form of a clear liquid, which boils at
124° C, like the modification obtained by Weidenbusch, and solidifies at 10°, starting
into crystals which also beein to melt at 10°.

2. Solid and infusible Metcddehyde. — ^Anhydrous aldehyde kept for some time in a
sealed tube or well stoppered bottle, frequentlv deposits transparent, colourless, four-
sided prisms, which traverse the whole Hquia like a network. The crystals remain
■olid at 100° C, but at a stronger heat sublime undecomposed, in the form of transpa-
rent, colourless, shining, rather hard needles, which are easily pulverised, inodorous,
combustible, scarcely at all soluble in water, but easily soluble in alcohol and ether
(Liebig). — ^Fehling, by exposing pure aldehyde to the cold of winter for several
wedu, once obtain^ the same crystals, mixed^ however, with a larger quantity of
the erystala b. They are hard and easy to pulverise ; at 120° they sublime without
pevious fusion. When they are suffered to evaporate in the air, the vapour condenses
m line snowy flakes (Liebig). Heated for some time to 180° in sealed tubes
they are leoonrerted into ordinary aldehyde. (Geuther, Ann. Ch. Pharm. cvi. 262.)

Alobhtdb-bbsin. — A resinous body obtained by heating aldehyde with potash, either
tn aqueous or in alcoholic solution, especially the latter. It is also formed in solutions

110 ALDEHYDES.

of the alkalis in alcohol, and in acetal, when kept fbr a long time. Aocoidinff to
WeidenbuBch (Ann. Ch. Fharm. IztL 153) itia a substance of a fieiy orange ocHonr
which is reduced by diying at 100^, to a powder, haTin|F a paler tint. It dissolves in
alcohol and ether, sparingly in water, scarcely at all in alkalis, partially in strong
sulphuric add, from which it is precipitated by water. When pnrified as completely
as possible, it contains 76*4 per cent of carbon, and 8*0 per cent, of hydrogen : its
formation is accompanied by that of acetic, formic and acetylous [?] acid ; at the
same time a punsent odour is eyolyed, proceeding from, a peculiar substance which
adheres obstinatdy to the resin. This substance is oily and volatile when first pro-
duced, but soon thickens, even when alone and still more quickly under the influence
of nitric acid, and is converted into a golden-yellow, viscid resin, which .«mells like
cinnamon, dissolves in alcohol and ether, and sparingly in water, and is different fiom
the true aldehyde-resin.

AlABBnSS. A class of organic compounds intennediate between alcohols
and acids. They are derived from alcohols by abstraction of 2 atoms of hydrogen,
and are converted into acids by addition of 1 atom of oxygen : thus in the fktty acid
series:

C-H«-+«0 - H« = C'H^O, and OH»-0 + 0 = OHK)«

Alcohol. Alddiyde. Aldehyde. Add.

Aldehydes may be regard d as derivatives : 1. Of a molecule of hydrogen HH, half
the hydrogen being replaced by an ozygen-radide : e,g, benzoic aldehyde or bitter-
almond oi^ C'H*0 -* (7H*0.H.— 2. Of a molecule of water, half the hydrogen being

replaced by a monatomic hydrocarbon, e.ff. benzoic aldehyde » rr f O; acetic alde-

hydfi B n; V ^' — ^-OftL molecule of water, in which the whole of the hydrogen is

replaced by a diatomic hydrocarbon: e.ff, acetic aldehyde « (C^^y'O. According to
this last view, which is strongly corroborated by the action of sulphuric acid and
chloride of zinc upon glycol (p. 102), the aldehyaes are the ethers or anhvdrides of
the diatomic alcohols, and are related to them in the same manner as the dibasic an-
hydrides to the dibasic acids ; thus

Type H*0* Type H«0

Sulphuric add ^^2 0* Sulphuric anhydride S0».0

Glycol ^»|^' Aldehyde CmO.

The following are the aldehydes at present known.

1. Aldehydes of the form OH*-0 = ^^""""jo - C^E^OJR.

Acetic aldehyde
Propionic „
Butyric „
Valeric „
(Enanthylic „

C*H*0

C»H«0

C^H-O

C»H»«0

CH^O

Capiylic aldehyde [?]. . (?H>«0

Enodic „ . . C"H«0

Laurie „ . . C*«H«0

Palmitic „ . . C»*H«0

2. Aldehyde of the form OH«"-«0 « ^^^'^jo « C^«-«O.H.
Aciylic aldehyde^ or Acrolein, C*H*0.

8. Aldehyde of the formG"H«-*0 « ^^"'gjo « OH*»-*0.H
Campholic aldehyde, or Camphor, C^'R^'O,

4. Aldehydes of the form OH*»-^ » ^^*^|o «OB>-K).H.

Benzoic aldehyde, or Bitter-almond oil, C^'O.
Cuminic aldehyde, or Oil of Cumin, O'BS),

6. Aldehyde of the form C-H*»-»0 - ^^*' gjo, or C-H«^>O.H.
Cinnamic aldehyde, or Oil of Cinnamon, CEPO.

6. Aldehydes of the form C-H*-^« = C-H«-^> q^ ^^ C-H«*-*0».H.

Salicylic aldehyde, or Salicylous add, C»H«0*.
Anisylic aldehyde, or Anisylous add, C'H'O*.

ALDEHYDES. Ill

The aldehydes tSonespondiiig to known alcoholB may all be fbrmed from thoM
iloobols by oxidation, either by ezposuie to the air in contact with platinum-black, or
bf distillation with a mixture of (ulnte snlphnric acid and peroxide of manganese or
acid ehromate of {wtaasinm. Aldehydes may also be prepared &om the corresponding
aods by a general process, Tic by distilling a mixture of the barinm-salt of the acid
with an eq[iuYaleDt quantity of formate of buium, thus :

Benzoate of Formate of Hydride of Carbonate
bariua. bariam. benzoyU oft>ariiim.

(Limpricht) Ann. Gh. Fharm. zcvii. 368 ; Piria, Ann. Ch. Phys. [8] xlyiii. 113).
This process is a particular case of Williamson's method of producing compound ace-
tones (p. 31).

Streril aldehydes, as benzoic, acetic, propionic, butyric, &c. are produced by the
distillation of albumin, fibrin, casein, and gelatin with peroxide of manganese and
Bolphnric acid. Some are formed in the destructive distillation of orgamc acids, as
atfUe aldehyde from lactic acid, cenanthylic aldehyde from ricinolic acid. Caprylic
aldehyde is said by some chemists to be produced (together with the corresponding
alcohol), by distilling ricinolic acid with excess of potash. According to Bonis
(Conpt rend. ilJiL 603), a new add, C^^H^^O', is formed at the same time :

Ricinolic Caprjlio

add. aldebjde.

But according to Malaguti (Cimento, iy. 401), the acid formed is sebadc acid
thns:

CWH"<0« + 20 « C"H»«0 + C»«H>"0*

Ricinolic Caprylic Sebacic

add. aldehyde. acid.

This deoomjposition is supposed to take place simultaneously with that by which
oetyfie (capirhc) alcohol is produced (p. 97). The aldehyde might indeed be pro-
dneed by oxidation of the aloohoL According to St adeler, on the othier hand (J. pr.
Chem. IxTxiii. 241), the product OH"0 thus formed is not caprylic aldehyde, but
methyl-cenanthyl, CH^.CH^'O, a body isomeric with it (p. 97).

Many aldehydes are obtained directly from plants, eitiier existing ready formed in
the plants, or being given off as rolatile oils on distilling the plants with water. Thus,
benzoic aldehyde constitutes the essential part of bitter-almond oil, cinnamic alde-
hjde of cinnamon oil, cuminic aldel^de oi Eoman cumin oil, and salicylic aldehyde
or saHcyloos add, of oil of spinea. Oil of rue consists prindpally of euodic aldehyde,
mixed with a small quantity of lauric aldehyde (0. G-. Williams, Proc. Koy. Soc. ix.
167). It was formerly supposed to be capric aldehyde. Benzoic aldehyde is also pro-
dnced by the action of nascent hydrogen (eTolved by the action of zinc on hydrochlo-
lie add) on cyanide of benzoyl, hydrocyanic being formed at the same time :

CrH*O.Cy + HH « (?H«O.H + CyH.

This mode of formation corresponds with the representation of aldehydes as hydrides
of add radicles.

All the known aldehydes (except palmitic aldehyde, which is a fatty solid) are
fiqiiidB, which Tolatilise without decomposition. They are yeiy prone to oxidation,
bong conyerted into adds more or less quickly by mere exposure to the air. In con-
seqoence of this tendency to oxidation, they easily reduce the oxides of the noble
metals (see p. 106). Hany aldehydes are conyerted by hydrate of potassium, espe-
cially in aleonolic solution, into the corresponding alcohols, and the potasdum-salt of
the oonrespondSng add : thus, with bitter almond oil :

2CrH«0 + KBO = CHK) + C*H*KO«

Bensoic Benxyl- Benxoate of

aldehyde. alcohol. potassium.

Cominie aldehyde and anisylic aldehyde are decomposed in like manner. The al-
dehydes of the first series (corresponding to the fatty acids) and acrylic aldehyde, are
not decomposed in this manner: acetic aldehyde treated with potash yields acetate
and formate of potassium and a brown rednous mass.

All aldehydes form definite, and for the most part crystalline, compounds with the
tod Rilphites of tiic alkali-metals, e. g, bitter-almond oil with acid sulphite of sodium.

112 ALDEHYDES.

C'H«O.SO«NaH « ^*| S0« + H»0 « Na.C'^»l ^' "*" ^^' '^^ eompounds
are for the most part soluble in water and alcohol, but insoluble in saturated solutions
of the alkaline bisulphites. Hence by shaking a liquid containing an aldehyde with
excess of such a saturated solution, the aldehyde may be completely separated in the form
of a crystalline compound. This is an excellent method of purifying those volatile oils
which haye the constitution of aldehydes. The acid sulphites of potassium and sodinm
are, generally speakine, the best adapted for this purpose, as the compounds which l&ey
form with the aldehydes are much less soluble in the solution of the sulphite than the
corresponding ammonium-compounds, and therefore crystallise more readily. From
all these compounds, the aldehyde may be set free by the action of the stronger acids^
or by neutralisation with an alkaline carbonate, and may then be obtained in the pure
state by distillation.

The (Udehydes of the first series combine with ammonia, forming crystalline com-
pounds like aldehyde-ammonia, C^H^O.NH', (p. 106), and yaleral-ammonia, 0»H»«O.NH».
These compounds treated with sulphuretted hydrogen yield sulphur-bases, like thial-
dine, C«H»«NS«, and yaleraldine, C»»H"NS«, thus :

3(C»H»«0.NH») + 3H*S - C"H«NS« + (NH*)«S + 3EP0.

Heated with hydrocyanic and hydrochloric adds, they yield bases similar to the last,
but containing oxygen in place of sulphur : e. g.:

C»H«*J0.NH» + CNH + CIH + HK) = C«H"NO« + NH*C1.

>*- — , — ^

Leucine.

Acrylic aldehyde appears also to combine directly with ammonia^ forming a white
amorphous compound.

The remaining aldehydes yield with ammonia pecuMar amides called hydramides,
the formation of which is attended with elimination of 3 atoms of water, e. ff.

3(C'H*.0) + N*H* = ^Cm'y + 3H*0

Benioie Hydrobenxa-

aldehyde. mide.

Z{CR*0*) + liPH* =r N'CC'H'O)* + 3H«0

Siilicylic Salhydramide.

aldehyde.

Aldehydes also combine with anhydrous acids (anhydrides), forming eompoonds
which are isomeric, but not identical with the diacid glycol-ethers. Thus acetic alde-
hyde unites with anhydrous acetic acid, forming the compound, C-H*O.C^H*0*, isomeric
with acetate of ethylene, C'H*.(C*H*0)*.0' ; — also with anhydrous benzoic and succinic
adds. Yaleral forms with anhydrous acetic, and benzoic adds, the componnda
C*H"O.C*H«0» and C*H'»0.Cte'O», isomeric with acetate and benzoate of amylene,
0»H'«.(C«H«0)«.0« and C»H»».(C'H»0)'.0«. These compounds heated with caustic
alkalis yield acetates, benzoatos, &c., of the alkali-metals, and reproduce the original
aldehydes, whereas the acetates, benzoates of ethylene, amylene, &c., under the same
circumstances, yield glycols, or hydrates of ethylene, amylene, &c (Geuther, Ann.
Ch. Pharm. cyi 249; Guthrie u. Kolbe, ibid. cir. 296.)

The caldum and barium-salts of certain monobasic organic adds, butyric and yalerie
adds, for example, yield by dry distillation, together with acetones (p. 31), compounds
isomeric with the aldehydes, but distinguished &om them by not combining with am-
monia: these compounds are called butt/ralj valeral, &c (Chancel, J. Pharm. [3]
yii. 143; Limpricht, Ann. Ch. Pharm. xc 111.)

Many of the aldehydes are susceptible of polymeric transformations. Acetic alde-
hyde exhibits three or four such modifications (p. 108) ; and benzoic aldehyde is yery
apt to pass into the solid substance benzoin, C'^H'^O*.

The acetones or ketones are aldehydes in which the basic atom of hydrogen is re-
placed by an alcohol-radide, thus : ^

Acetone . ^^j 0 . ggOJ
yalerone«g:i:jo.O;H;0|

Valeracetone - C*^-) ^ _ C'H'O) ^^ C«H») ^ .. C^H»0)
vaieracetone - CH*J ■" " CE*\ ^^ C*H»J ^ — C*H» }

A&BXBS. The generic name applied by L. Gmelin, in his Handbook, to the alde-
hydes, the latter term being by him restricted to acetic aldehyde. In Gmelin's system,
the term indudes seyeral organic anhydrides and other compounds not generally re-
garded as aldehydes. (Handb. yii 192.)

ALEMBIC— ALIZARIN. 113

U An apparatus for distOIation, mnch used by the older cheimBta. It
toaatia of a bodj a, to which is adapted a head b, of conuad shape, and having ita
ertezsal cinnimferenoe or haae depre^ed lower than -^ .

the neck, so that the ti^qis whidi nae and are oon- ^ ^*

doved against the sides, run down into the circular &
ehuoel fonned hj its depressed part, whence they /
pass throng the noee or Beak c, into the leoeiyer a. l^/^^\ |j\^
xlie alem^ is now searoelj nsed in the laboratoiy,
being snpeneded Inr the retort, which is simpler and
leas expeBsire. Nerertheless, the alembic has its
•drastages. In particniar the residues of distilla-
tions maj be easilj cleared out of the body a; and in
<*xpenments of sublimation, the head is yeiy con- V.«.«x^ d^

tenient to receiTe the dry podncts, while the more <>

volatile portions pass OTer mto the leoeiver. Glass
aleinbics are now nsed in some manufactories of sulphuric acid for effecting the final
eondensition of the acid.

■T* A namegJYen by the alchemists to one of the double
chloiideB of mercniy and ammonium, 2(NH^CLHgCl) + H'O, also called Salt of wisdom,

(See Chbtsobbbtl.)

(Powder of). The alchemical name for the ozychloride of anti-
aitty, produced bj throwing the chloride (butter of antimony) into water.

I — A hydrated silicate of alumina, occurring in New Jersey, and crys-
talHshig, sometimes in right, sometimes in oblique prisms. The following analyses of
it hsTe been giren by Hunt and Crossley :

Silica 62-16 6200

Ahimina 26*08 26*42 *

Sesquioxide of Iron .... 1*94 1*64

Magnesia 1*21 6*39

Potash 10*69 10*38

Water r92 6*27

100 . 100*00

(See NuTBrnoN.)

An acrid, bitter extract, probably a mixture of several compounds,
4]]itained from the water-plaintain (Jlisma PUmtago) ( J a c h, fiepert Pharm. iv. 1 74 ;
fi 246.)

^^-^^Tft^ftTfTlfflMt A crystalline substance, sometimes deposited on the
inner snr&foe of the bark d Mixta aromatica. The crystals are white and capillary, with
a slight aromatic taste and tiiie agreeable odour of the plants They sublime undecom-
poaed between 70° and 80°G., but at higher temperatures they melt and form a brown
sabatanoe. ThOT are insoluble in cold, but soluble in warm water, forming a neutral
sofaitiini, which depoeits the crystals unaltered ; so likewise does the distillate obtained
from this solution. They dissolre readily in alcohol of 80 per cent, in ether, oil of
tupentine, caustic potash, carbonate of potassium, and caustic ammonia. Nitric acid
of ap, gr. 1*2 does not dissolye, but merely colours them yeUow. (Handwort d.
Ghem. i 431.)

AXaOLABlO AOUK Obtained by Schunck by the action of nitric acid on alizarin,
and shovn by Wolff and Strecker to be identical with Laurent's phthalic acid (which
see.)

C"H«0* + 2I£K) [orC»fl^*0»+4J5rO]. Xwrarwacw?.— A red colour-
ing matter obtained from' madder. It was first prepared by Bobiquet and Colin
(Ann. CL Phys. [2] zxziy. 226), who obtained it by digesting poxmded madder with
wikt«r at 16° or 20° C, exhausting the gelatinous extract thereby obtained with alcohol,
tad treating the alcoholic solution, after concentration, with dilute sulphuric acid. A pre-
cipitate was thereby obtained, which, when washed, dried, and sublimed, yielded aliairin
in long brilliant needles^ haying the red colour of natiye chromate of lead. Alisarin is
ideatical with Bunge's madder-red (J. pr. Chem. y. 362), and with the somewhat impure
•Mtii^ eoA>ran<efvi^«; obtained from madder by Pers OS and Gaultierde Claubry
(Ann. Ch.Phys. [2] xlyiii 69), and has been prepared in the pure state by Schunck
(Ann. Ch. Pharm. Ixvi 174), by Debus (ibid. Ixy. 361), and by Wolff and Strecker
(ibid. Ixxy. 1). It appears not to exist ready formed in madder, but to be produced
hj the decomposition of rubian and rubeiythric acid. (See Maddbb.)

Vol. I. I

114 ALIZARIN.

Preparation aeeording to Wolff and Strecker. — Madder is ezhansted with bolHiifr
water; the decoction is precipitated by salphnric add; and the washed precipitate
while yet moist, is boiled with a concentrated solution of alumina in hydrochloric add,
which dissolves the colouring matters, and leaves a dark brown residue. The solutiozi
mixed with hydrochloric acid deposits red flakes, consisting of alizarin, more or less
contaminated with purpurin and resinous matters. This precipitate is dissolred in
alcohol, or in dilute ammonia^ and the solution is treated with hydrate of alumins.
which unites with the colouring matters ; and the alumina-componnd thus formed is
boiled with carbonate of soda, which dissolves the purpurin and leaves the alizarin in
combination with the alumina. Lastly, this compound, after being freed from resinous
matters by digestion in ether, is decomposed by hot hydrochloric acid which dissolves
the alumina; and the alisarin thus separated is washed, dried by single ea^MMure to
the air, and purified by repeated crystidlisation from alcohol

According to Schwartz (Bull, dela Soc industr. de Mulhouse, I860, Ko. 135), the
purest alizsrin is obtained by subliming on paper an alcoholic extract of madder having
at least 36 times the colouring power of the root itsell According to Plessy and
Schutzenberger(Gompt. rend, xliii. 167), when an extract of madder prepared with
wood-spirit, is triturated with a tenfold quantity of water, and heated to 260^ in a
closed vesselj^the water on cooling becomes filled with ciystals of alizarin ; and the
f ased extractive mass remaining at the bottom of the vessel, yields, when again treated
in the same manner, an additional quantity of very pure alizarin.

Anderson, by treating opianic acid (0'*H*^* = alizarin + 2HK)) Wiili sulphuric
acid, obtained a colouring matter (probably alizarin), which yielded all the madder
colours with alumina and iron mordants. (Edinb. PhiL Trans, xxi. 1, 204.)

Alizarin in the anhydrous state fonas red prisms, inclining more or less to yellow,
according to the size of the crystals. It combines with 2 at. water, forming scaly
crystals like mosaic gold. These crystals give off their water at 100 *^0., becoming
opaque and of a darker colour. At 216^ the compound sublimes, yielding a crystalline
subUmjfte of the same composition as alizarin dried at 100^ ; neverthelesa a consider-
able quantity of charcoal is always left behind.

The following are the mean results of the analyses of alizarin dried between 100^
and 120^ or sublimed :

Caleuiation, Boblqoet. Schuodc. DebilB. Rocbleder.

IOC . .120 68-96 69-72 69*4 68*96 67*93

6H . . 6 8*46 3*74 40 3*78 8*77

3 0. .48 27*69 26*54 26*6 27*26 28 80

C»HH)» 174 10000 100*00 100*0 10000 100^^

Shtrock atttgna to crjitalllsed alisarin the formula C^*H^O* -f 8H0 Armrdioff to the fominla
CieH<03, alisatin if doselr related to Laurent's chloronapthalle acid, Ci0H>ClO>. The latter, when
hoiled with nitric acid, yielda phthalic and oxalic acid, like alitarin (vtf . ^.).

Alizarin dissolves but sparingly in water, even at the boiling heat ; but acooiding to
Flessy and Schiitzenberger (he. cit.) its solubility is much increased by heating to
higher temperatures in close vessels, 100 pts. of water dissolve 0*034 pt. of alizarin
at 100® C. ; 0*035 at 150^ ; 0*82 at 200<^ ; 1*70 at 226^ ; and 3*16 pts. at 260^.

Alcohol and ether dissolve it, forming yellow solutions. It is not decomposed by
hydrochloric acid. Strong sulphuric acid dissolves it, forming a brown solution from
which the alizarin is precipitated by water in orange-coloured flakes. Nitric acid at
the boiling heat dissolves it, with evolution of red vapours, forming phthalic acid and
probably also oxalic acid (Wolff, u. Strecker):

C»H«0" + H«0 + 40 « C«H*CH + C»H*0*

^ r— ' ^ , ' V , »

Alizarin. Phthalic Oxalic

acid. acid.

It is also converted into phthalic acid by boiling with ferric chloride or mtiate
(Schunck). Chlorine converts it, when suspended in water, into a yellow substance
which dissolves in alkalis without much colour, and yields a colourless sublimate when
heated.

Alizarin dissolves in caustic alkalis and in alkaline carbonates, forming deep purple
solutions, from which it is precipitated by acids in orange-coloured flakes. The ammo-
niacal solution gives off all its ammonia by evaporation, and forms with the chlorides
of barium and calcium purple precipitates which become nearly black when dry. The
potash solution is completely decolorised by lime-water, a precipitate being formed
containing 2C"H«0».3CttHO, or 2C»H*0'.S{CaO,HO), Wth baryta, in a similar
manner, two compounds are formed, viz. 2C"H»0'.3BaHO and C"H«0».2BaH0. Alu-
mina decolorises an alcoholic solution of alizarin, forming a beautiful re<l lake. An
ammoniacal solution of alizarin forms with salts of magnesium, iron, copper, and silver.

ALE ALL 115

fnipla precipitAt66 with a tqiI or bluish iridescence. The silyer precipitate becomes
icdaeed after some time. The alcoholic solution of alizarin forms yriih. an alcoholic
loktion of acetate of lead, a purple precipitate containing 4C'»H*PbO*.3Pb*0, or
2C»S*PbO'.3PbO, according to Schunck, and 3C"H«0».2Pb«0, according to Debus.

(See PDanjTB.)

jileaH, LauffensaU, The word alkali is used in Tuious senses. In
its most reatricted, bat most usual sense, it is applied to four substances only : hydrate
of potasshim (potash), hydrate of sodium (soda), hydrate of lithium (lithia), and hy-
drate of ammonium (which may be supnposed to exist in the aqueous solution of ammonia).
In a mors geserml sense, it is applied to the hydrates of the so-called alkaline earths
(bsiyta, stiontia, and lime), and to a large number of organic substances both natural
snd sitifidal, wiiich are more folly described in the articles Alkaloids and Ajtxosjjju-
sasBS. The first four bodies are sometimes spoken of as alkalis ^proper, when it is
wi^cd specially to distinguish them from the other alkalis.

As the iiidiTidiial alkalis are described with sufficient detail in the articles specially
dervitedto each, we shall confine this article to a discussion of those properties which
they an possess in common ; in order, as fur as possible, to define the essential nature
of alkalinitr, and to point out upon what grounds this or that particular body is classed
as sn alkali. These objects wiU probably be best attained by tracing the most im-
portant of Che snceessiye steps by which the word alkali, which was at first the name
of a single substance, has come to be the generic name of an indefinite number of bodies.

The tenn alkali was first used in chemistiy to designate the soluble part of the ashes
of plants, especially of sea-weed (carbonates of sodium and potassium). It was, how-
em; soon extended to seyeral similar substances which were obtained by other pro-
eesses : for instance, to salt of tartar and to carbonate of potassium, obtained by heat-
ing nitre with charcoal. The substances obtained by these processes, and by others
of like nature, were regarded as identical, or at most, as mere yarieties of the same
substance. Alkali was, therefore, not yet used as a generic name, but as the specific
name of a particular substance. The character which was chiefly depended upon for
distingnishing alkali from other substances was the property of efferyescing with acids.
This piToperty was supposed to be characteristic of, and essential to, alkaline bodies,
till after the middle of the 18th century. Another property of alkali which was early
obeerred was its opposition to adds, and power of destroying their most distinctiye
charaeten. On account of its possessing these properties, carbonate of ammonium,
which had been known since uie thirteenth centuiy, was, from the beginning of the
serenteenth century, regarded as a kind of alkali. The power of alkaU to change many
TEgirtable colonrs was recognised at a later period than the properties aboye mentioneo,
hat was well known to Boyle, who also knew that colours which had been thus altered
eookl be restored by acids.

It wraa fint clearly established in 1736, by Duhamel, that there exis^d two essentially
dlstiiiet kinds of fixed alkali From this time, three kinds of alkali were recognised,
— regetable alkali, mineral alkali, and yolatile alkali, corresponding respectiyely to
potas£, soda, and ammonia, or to their carbonates.

We haye already said that, far on in the eighteenth century, the power of efferyes-
cing with acids was regarded as an essential property of alkalis. Boyle had indeed
obeerred, in 1684, that yolatile alkali could be obtained by distillation oyer quick lime
in a condition in which it no longer efferyesoed with adds, although it retained all its
other usual prupertiea. But, notwithstanding isolated obseryatious of this kind, non-
cfltfrieseing alkalis were regarded ra^er as subordinate yarieties of the ordinary
alkalis than as essentially different substances.

Moreoyer, it was known at a yery early date, that quick lime altered some of the
properties of alkali. This alteration was expressed by calling alkali, which had hot
been acted on by lime, mUd^ and alkali which had been so acted on, caustic. The
eflect of the lime was ascribed by Basil Valentine (latter half of the fifteenth century)
to heat {^ die Hitse ans dem lebendigen Kalk ") which it imparted to the alkali. And
the idea that lime in burning combined with an actiye principle — " matter of fire " -—
which it gaye out again partiaUy to water (when shJced), and completely to alkali,
remained long dominant. Van Helmont (circ. 1640) regarded the substance taken up
by K»M» as akind of sulphuric acid, whence the heat eyolyed in the action of water on
qoick lime. Meyer, as recently as 1764, supposed the lime-salt of a peculiar acid,
addum pinantj to be formed during the burning of lime, and that when this salt was
treated wiu a mild alkali, a corresponding alludine salt (caustic alkali) was obtained.
The gieaay feel of the caustic alkalis suggested the name of the add which Meyer
si^^XMed them to contain.*

• It k a rcn«rkabl« inuatratlon of the change which takef place in the ideas attached to the tame
word, that both Van Helmoat aiwl Meyer should have attribntrd what we coniider an exaiuuon of the
•tkmbmt pfopeity to the agency of an add. (See Aciua, lee p. 4a)

X 2

116 ALKALI.

The trae nature of the diffisrence between caustic and mild alkaliB was disooTered
by Black in 1765. Black's investigation of this subject occopies so important a place
in the history of general chemical thecvy, that it is worth wlule to consider a little in
detail his experiments and the condnsions he derived from them.

His first observation was that qnick lime, when deadened by expusure to air, became
heavier, not lighter, as was to be expected, if the change which took |^ace consisted
in the escape of fire-matter. He made a similar observation in the case of magnesia
(a snbstance wluch he had previonsly found to be distinct from. lime). He fonnd fozther
that«magnesia, in the state in which it effervesces with adds, lost considerably in
weight when calcined, and that it then no longer effervesced with adds, althongh it
formed with them falts exactly similar to those of effervescing Tnsgnesia, In ordw to
find oat what was \^o substance which effervescing magnesia lost when caldned, he
repeated the calcination in a retort connected with a well cooled reodver. In this
experiment, he obtained nothing but a small quantity of water ; it occurred to him,
however, that a gas might have escaped, and that this gas might be the same as that
which is evolved during the solution of magnesia alba (effervescing magnesia) in adds.
Following out this supposition, he came to the condnsion that the eiServesdng mag-
nesia which is predpitated by a mild alkali from a solution of caldned (not efiervesdng)
magnesia in add, could obtain the 01s, which caused it to effervesce when dissolved,
from no source except the alkali. Hence he conduded further that the mild alkalis
contain the same gas as is expelled from magnesia alba by calcination ; that, when
they combine with adds, this gas is separated and causes effervescence ; and that,
when a magnesia salt is predpitated by a mild alkali, the gas leaves the latter and
unites with the magnesia, in cembination with which it is predpitated. These con-
dnsions were verified by the following quantitative experiment. A weighed quantity
of magnesia alba was caldned ; it then dissolved in sulpnuric add without effervescence.
The solution was predpitated by mild vegetable alkidi (carbonate of potassium), the
precipitate washed, dried, and weighed : its weight was almost exactly the same as
that of the original magnesia alba, and it behaved in every respect like that substance.
On a further examination of the gas, whiclw^xpelled by adds from the mild alkalis
and lime, and from magnesia alba. Black fo^^^^to be the same as that which is formed
during fermentation, and gave it the name^Hrmr.

From the sum of his observations, Black deOjU^ed the following general condnsions.
The effervescing earths and alkalis contain fix A air, which can be expelled from the i

former by heat, though not from the latter, bunlirhich is expelled from both by adds ; ■

the alkalis and earths are caustic when tiiey eont^^ no fixed air, and therefore l^eir
causticity does not depend on the presence of any peculiar constituent, but is a pro- s

pcrty possessed by them in a state of purity ; quick lime renders the alkalis caustic, |

not by imparting to them any prindple of caustidty, but by the removal from them
of fixed air ; lasUy fixed air partially neutralises the alkslis by combining with them,
insomuch as it destroys their causticity.

Two of the most important effects which the adoption of Black's theory had upon I

the received ideas of alkalinity were that it caused chemists to perceive (which they
had not done before), a necessary opposition between the causticity of an alkali and
its power of effervescing with acids, and caused the term alkali to be transferred from
the carbonated to the caustic alkalis.

Besides the substances to which the name alkali was first given, it was soon per-
ceived that certain kinds of earth possessed, in some degree, alkaline properties ; that
is to say, the power of effervescing when acted on by acids, and of neutralising their
add properties. Earths which possessed these qualities were called terrts absorbenteSf
or terrtB rJcalina, and were long supposed to owe their peculiarities to the prraenoe
of alkali as one of their constituents.

It is not easy to make any precise statement as to the degree of similarity or of
difference which was supposed to exist betweep these bodies and alkali proper. The
difficulty arises partlv from the fact, that, until they had acquired some icfea of the
principles of chemical analysis, chemists had no sure means of ascertaining the iden-
tity or individuality of chemical substances, and hence often called different bodies by
the same name, or, on the other hand, gave different names to the same substance
when obtained by different processes ; partly also, from the word alkali having been
used formerl V as now in various senses : by Lemeiy, for instance, to indude aU sub-
stances which effervesce with acids ; by Stahl, to indude all those which neutralise
acids ; by many others, however, to denote none but the substances now known as the
Alkaline carbonates. This uncertainty in the use of the word is not surprising, when
we remember that our present more extensive knowledge does not enable us to point
out any one difference of fundamental importance between the alkalis and the alkaline
earths. The different solubility in water of their carbonates probably furnishes a more
exact distinction than any other single property. This character was pointed out by

ALKALI. 117

Babaiiiel in 1736, as a generic difference. He distinguished earths from alkalis hj
the property -vfaich the latter have of precipitating the fonner from their solutions,
and the alkaline earths from others by their capability of completely neutralising acids.
These distinctions have, for the most part, been ever since retained.

It is not necessary to discuss with much detail early ideas relating to the ultimate
eonstitixtion of the alkalis and alkaline earths. A similarity of constitution between
the eazths and metallic calces was soon suspected ; in consequence of which Neumann,
befefe the middle of the eighteenth centoxy, endeavoured to get a metal from quick
lime. By the later |>hlofi;istic chemists, both alkalis and earths were, like metallic
cakes, regarded as sunp& bodies. Lavoisier, though he regarded metallic calces as
eompoandfl, continued to class the alkalis and earths among elementaiy bodies, inas-
much as there waa no known means of decomposing them. He considered it probable,
howereTy that they contained oxygen, and suggested that the earths might be oxides
cf metala which had a greater affinity for oxvgen than carbon, and therefore could
not be reduced. Hanj attempts were made by Lavoisier's followers to verify these
SBppositions ; but their uniform failure seemed almost to have px>ved the elementaiy
nature of the bodies in question, when, in 1807, Sir Humphry Davy succeeded in re-
ducing potash and soda by the galvanic current. The composition of volatile alkali
(aBanooia), was approxnmvtely ascertained by Berthollet in 1785. After the discovery
of oxygen in the fixed alkalis, it was long supposed by Davy and Berzelius that am-
monia also contained oxygen. The idea that aqueous ammonia contained the oxide of
m eompoond metal, which likewise existed in the anmionia-salts, was suggested by
BeneliiiB in 1820. (See Amxoiouk.)

In the present state of chemical theory, the relations of the alkalis to other sub-
stances lead to the representation of them as hydrates, or as water in which haJf the
hydrogen is replaced by a metal, or compound radicle. (See Ttfbs.)

The earliest addition made by modem chemistry to the old list of alkalis was morphia,
diacoyered in opium by Sertiimer in 1805, but first fully described by him in 1817.
This was the &r8t organic alkali, or alkaloid which became known ; but, when the
general attention of <memi8ts was directed to its existence, it was soon found to be
one of a very numerous class of compounds (see Alkai.oids). Of late years, a huge
munber of bodies, possessing many points of resemblance to the natural dkaloids have
been obtained by artificial processes. The constitution of these artificial alkalis is
Himflar to that of hydrate of ammonium: they represent hydrate of ammonium in
'vfaidi hydrogen is replaced by an electro-positive radicle (in most cases a hydrocarbon),
(see AMMomnx-BASBs), or in which nitrogen is replaced by phosphorus, arsenic, or
antinKHiy.

The fcDowing properties are common to the mineral alkalis and to many of the
nsganic alkalis.

(1) They are more or less soluble in water, the alkalis proper much more so than
the alkaline earths. (2) They neutralise completely the strongest acids, and with
veak acids form salts possessing in some degree, alkaline properties. (3) Their aqueous
•ohitions exert a caustic or corrosive action on vegetable and animiU substances. (4)
Precipitate the heavy metals from most of their acid solutions as hydrates or as oxides.
(5) And alter the tint of many colouring matters ; for instance, they turn Utmiis, which
has been reddened by add, blue, they turn turmeric brown, and syrup of violets and
jnfasion of red cabbage, green. The extent to which the various alkalis dissolve in
vster appears to determine the degree in which they possess the last three properties
(3, 4, 5), the most soluble possessing them in a greater degree than the rest The action
oo eolonring matters appears to bdong to all metallic hydrates which are soluble in
-vmter, and is possessed by the hydrates of lead, silver, and mercury, in a degree cor-
ro^jonding to their slight solubility.

(For iiirther historical details concerning alkalis and alkaline earths, see Kopp,
Oesefaichte der Chemie, vols, iii and iv.)i — G« C. F.

^ Trl^ ^ ^- ■ — ■■■■o^ is the determination of the amount of real alkali in alkaline
mixtures and liquids, such as the commercial carbonates of potassium and sodium,
(commonly called potash and soda), in wood-ashes, solutions of caustic and carbonated
alkalis, &c. This estimation, like tiiat of the strength of acids, may be made either
by volumetric or by weight-analysibk

The Tolumetric method ef alkalimetry is merely a particular case of the general
method of "Analysis by Saturation," described in the article Axaltbis, Yoxtthbtrio
(which see). The valuation ef an alkali by the amount of a standard acid solution
which it will saturate, was first introduced by Descroizille, afterwards peifected
by Gay-Luseac, and still farther by Mohr. (Lehrbuch der chemisch-analytischen
Titrirmethode, Braunschweig, 1855.)

Instead of the sulphuric or hydrochloric acid generallv used for the purpose, Mohr
xeconunends oxalic acid, because it oin be weighed with greater accuracy than any

118 ALKALIMETRY.

liquid acid, and becauBe itd standard solution may be kept for any length of time with-
out change. To obtain it pure, the commercial acid, which is genersliy oontaminated
with the oxalates of potassium and calcium, is finely pounded, and treated with a
quantity of lukewarm water sufficient to dissolve only a portion of it ; the solution is
filtered and left to crystallise ; and the crystals are collected on a filter and dried in
the air, till they no longer adhere to each other or to the paper. The add is thus
obtained pure, and containing exactly CH'O^ + 2HH), the atomic weight of which
is 126.

The standard solution is best made of such a strength that 1000 cubic centimetres
(1 litre), shall contain exactly one |-gramme-atom (i,e. 1 atom expressed in ^-grammes)
of the acid. This is efiected by dissolving in water ^ » 63 grammes of tiie ciystals,
and diluting the solution to the bulk of 1 litre. 1000 c c. of this solution contain one
|-gramme-atom of add : hence 2 c. c. contain 1 milligramme-atom of add, and
saturate 2 milligramme-atoms of a caustic alkali (KHO or NaHO), 1 milligramme of
an anhydrous alkali (K«0 or Na*0), or of an alkaline carbonate (CO»K« or CO»Na«.)

To estimate the value of a sample of commerdal potash or soda, 3 or 4 grammes of
it are first ignited in a platinum crucible in order to determine the amount of water
contained in it. The residue is then dissolved in water ; a few drops of litmus are
added ; and the standard add is gradually added from a burette till the first appearance
of a purple-red or wine-red colour. This takes place when a Uttle more than half Hie
alkaline carbonate is decomposed by the oxalic add : for the first portions of carbonic
add disengaged by the oxalic add, imite with the remaining portion of alkaline car-
bonate to form add carbonate, and it is only when half the alkui has been neutralised
in this way that the carbonic add is actually set free and reddens the litmus. After
this stage has been attained, the oxalic acid must be very cautiously added till the
purple-red produced by the carbonic acid, just passes into a bright yellowish-red, in-
dicating the presence of free oxalic add, and showing that the whole of the alkali is
neutralised by that acid. Each c c of acid thus employed corresponds to 1 milli-
gramme of caustic alkali, or to one |-milligramme of alkaline carbonate, t. e. to 0*040
grm. caustic soda (NaHO), 0-056 grm. caustic potash (KHO), 0'069 grm. carbonate
of potassium (CO'K^), and 0*053 grm. of carbonate of sodium. The amoimt of caustic
alkali or alkaline carbonate is then found by a simple proportion ; thus :

100 : 5*3 : : number of c. c. employed : amount of carbonate of sodium.

By operating on 100 times the f-milligramme-atom (e,g. 6*0 grms. of carbonate of
potassium, or 5*3 grms. of carbonate of sodium), all calculation is saved : for as this
amount, if perfectly pure, would require 100 c. c of add for its saturation, the number
of c. c. actually required indicates at once the percentage of alkaline carbonate. The
burettes commonlv used contain 50 c. c, and are graduated into half c. c ; so that by
operating on 50 times the |-milligramme-atom, the number of divisions employed in-
dicates the percentage.

In operating upon alkaline carbonates in the manner just described, it is difficult to
notice the exact moment when the wine-red colour of the litmus due to the presence
of free carbonic acid, changes to the light red produced bv oxalic or other strong add.
For this reason Mohr recommends the following, called the residual method. The
standard add is added till the colour of the litmus is distinctly bright red ; the solu-
tion is then heated to boiling, and a sUght excess (^5 to 10 c c.) of add is added.
The hot solution is freed from carbonic add by agitation and by arawing air throng
it by means of a glass tube, and then neutralised with a standard solution of caustic
soda (Analysis, Volumstbio), till the colour just changes from red to blue. Since
the acid and alkaline solutions neutralise each other, volume for volume, it is only
necessary to deduct the number of cubic centimetres employed of the latter from,
that of the former, and calculate the amount of alkali from the reddue. In esti-
mating the strengtJi of caustic alkaline solutions, this residual method is of course
unnecessary.

To determine the proportion of caustic alkali and alkaline carbonate in a mixture of
the two, two equal portions of the solution must be taken : one of them treated with
chloride of barium, whereby the alkaline carbonate is converted into chloride, and car-
bonate of barium is precipitated. The liquid is filtered and the quantity of caustic
alkali determined in the filtrate as above. The second portion of the solution is
neutralised with the standard add, without previous treatment with chloride of barium,
and the total amount of alkali, existing both in the caustic state and as carbonate, is
thereby determined. The first result deducted from the second, gives the quantity of
alkali^ existing as carbonate.

If it be preferred to make these estimations with the ordinary English weights and
measives, the standard solution of oxalic add may be made by dissolving 63 grains
(f-grain-atom) of the crystallised add in water and diluting the solution to lOOO

ALKALIMETRY.

119

Fig, 6.

^ at 60° F. This quantitT of the solution will then neatraluse 1 gndn-

itom of a eaDstie aUuli (40 grains of soda NaHO, or 56 grains of potash KSO ), and
l-grain-atom of alkaline carbonate (69 grains of 00%^ or 63 grains of CO'Na')i and by
opezatiDg on ^ of these quantities of the substance to be tested, the percentages viU
be given at onoe by the numbCT of grain-measures of the standsid add employed.

A eonveiiient method of estimating by -volumetric analysis the proportion of potash
and soda in a caustic mixture of the two, has been kindly commimicated to the Editor
by Mr. Jc^in Dale of Combrook, near Manchester. It depends upon the fact that
acid tartrate of potassium, though moderately soluble in water, is but yery sparingly,
if at all, aolidde in a liquid containing acid tartrate of sodium. The method is as
foOovB : Add to the mixture a standarcL solution of tartaric acid till an add reaction
just hewmtgii peceeptible ; the alkalis are thereby converted into neutral tartrates ;
then add a saoond quantity of tartarie add equal to the first, so as to convert them
into add tartrates : the whole (or nearly the whole) of the acid tartrate of potassium
then separates. Next filter off the solution of add tartrate of sodium, and add a
standaro. solution of eanstie soda till the. liquid just exhibits an alkaline reaction.
Hie quantity of the soda solution thus added is equal to the amount of soda present
in the mixture. — ^The quantity of tartaric add required to form add tartrate with the
sodsy subtracted from the total quantity added to the mixture of the two alkaHs, gives
the quantitT required to form acid tartrate with the potash ; and thus the amount of
potash is determined. This method would scarcely be applicable where sdentific
aecuzacy is required ; but, for rapid estimation in commercial practice, it is found to
give good results.

AUu^^anetry by Waght-amdyna. — The proportion of alkali in the commerdal car-
bonates of notassium and sodium may be estimated by determining the quantity of car-
bonic anhyoride evolved when the carlbonates are decomposed
by an add: for 22 parts of carbonic anhydride (CO*) corre-
spond to 69 parts of carbonate of potassium (CO'K*), and to
Z5 ports of carbonate of sodium (CCKN'a'). The apparatus
em^oyed is the same as that described in the article AciDX-
USTBT ; but the method of using it is slightly different A
weighed quantity of the carbonate to be examined is dis-
solved in warm water in the flask a, and a quantity of hydro-
diloric or dilute sulphuric add more than suffident to
decompose the carbonate, is placed in a short test-tube 5,
which IS carefully introduced into the flask, so that it may rest
agiainst the side. The apparatus having been then weighed,
the extremity of the tube o is dosed by a plug of wax, and
the flask is tilted so that the add may run over into the
alkaline liquid. When the evolution of gas ceases, the flask
is heated to complete the decomposition ; the wax plug is
removed and air ^wn through the apparatus to remove the
carbonic add remaining in it ; and the flask after cooling is
again weighed to ascotain the loss of carbonic acid. At
the condusion of the experiment, a piece of blue litmus-paper must be thrown into the
flask, to try whether the liquid is acid ; if not, more add must be added, and the pro-
cess repeated.

The apparatus of Will and Fresenius {fig, 6) may also be used. The alkali dis-
solved in water is then placed in the flask ▲, and
strong snlphttrie add in b; and the whole appa-
ratus is weighed; the tube a 6 is dosed with a
'wx plug; and suction is applied by the mouth at
the end of the tube c?, so as to draw a few bubbles
of air firom ▲ into b. On discontinuing the suction
the pressure of the air forces a small quantity of the
add in b into the flask a, whereby a portion of the
alkaline carbonate is decomposed. This process is
r^eated as long as any gas continues to be evolved,
after which the flask ▲ is heated, and the experi-
ment completed in the manner just decribed.

Xf the alkaline carbonate contains any caustic al-
kali, which may be known (in the absence of sul-
phide), by its solution having an alkaline reaction
after the addition of excess of chloride of barium,
another equal portion must be mixed with about one-
thiid of its weight of carbonate of ammonium, and

3 parts of quarts-sand (to prevent caking), and heated till the water and ammonia are

X 4

Fig,^;

120 ALKALOIDS.

expelled ; tlie diy residue 19 then decomposed as abore. The excess of alkaline caiv
bonate obtained in the second determinaUon is due to the caustic alkali in the sample,
which is converted into carbonate bj ignition with the carbonate of ammonium ; and
from it the amount of caustic alkali is easilj calculated ; thus for soda :
CO»Na« : 2NaH0 [or CO'.NaO : NaO.HO] « 106 : 80.

The sulphites, hyposulphites, and sulphides of the alkau-metals, which often occor
in commercial samples of alkali, especiiJl^ in ** baU-soda," introduce errors both into
the Tolumetric and the weight-analyBes : into the former, by neutralising a portion of
tlie test-acid, and into the latter by OTolving sulphurous acid or sulphuretted hydro-
gen, which would be estimated as carbonic acid. When the amount of alkali is to be
determined by the volumetric method, these compoxmds may be decomposed by igniting
the substance with chlorate of potassium, whereby they are aU converted into sulphates.
For the carbonic acid estimation, they ma^ be oxidised by adding a small quantity of
neutral chromate of potassium to the solution in the flask, before commencing the de-
composition.

The carbonates of the earths, which would introduce similar errors, may be removed
by dissolving the alkaline carbonate in water and filtering.

Organio Jlkalis^ Organic Bases. — ^At the banning of this oentnrv*
the only substances in which alkaline properties had been recognised were potash,
soda^ ammonia^ and the alkaline earths (see At.kat.t). In 1817i Sertiimer drew
attention to the existence in opium of a* substance whose alcoholic solution acted upon
vegetable colours like the solutions of the alkalis, which combined directly with acids,
forming neutral salts, soluble in water, and giving the usual reactions of the adds
from which thev were formed ; and which was precipitated from solutions of its salts
by the mineral alkalis. To this substance, Sertiimer gave the name morphine, and
in consequence of its possessing the properties just mentioned, regarded it as a kind
of alkali. After the discovery of morphine, it was soon found t^t many vegetable
products which had been long known as exerting marked physiological ^ects (e. g.
cinchona bark, nux vomica, tobacco, &c), contained similar alkaline principles. The
nimiber of such natural alkaloids now loiown is very great, and indudes many sub-
stances which cannot in any strict sense be termed alkalis, but which are connected by
such insensible gradations (between intermediate terms) with substances decidedly
alkaline, that they must be regarded as possessing essentially the same chemical
nature as the latt^. Since 1848, a great number of organic alkalis have been obtained
artificially. Some of these rival potash and soda in the degree of their alkalinity,
while in others the existence of alkaline properties is barely perceptible.

The only property which is possessed by all alkaloids, whether natural or artificial,
is that of combining directly with acids to form salts possessing a certain degree of
stability, and capable, when dissolved in wat-er, of producing the ordinary phenomena
of saline double decomposition. Those alkaloids, whose salts possess any considerable
degree of stability, generally exhibit, when dissolved in water or alcohol, an alkaline
reaction with vegetable colours.

Most of the natural alkaloids contain carbon, hydrogen, nitrogen, and oigrgen, and
are, at ordinair temperatures, solid, and not volatile without decomposition. Some
natural alkaloids contain carbon, hydrogen, and nitrogen only; these are, for the
most part, liquid at ordinary temperatures, and can be distilled without decomposition.
The greater number of the artindal alkalis are composed of carbon, hydrogen, and
nitrogen ; some, however, contain oxygen in addition. In both natural and artifidal
alkaloids, hydrog^en may be replaced by chlorine, bromine, iodine, peroxide of nitrogen,
&c Alkaloids have also been obtained artifidally, in which nitrogen is replaced by
phosphorus, arsenic, antimony, or bismuth. (See Phosphinbs, Absinbs, &c)

Most of the alkaloids, as they are obtained in the free state, correspond in compo-
sition to ammonia, NH», rather than to the fixed alkalis ; that is to say, they form
salts by direct union with acids, without elimination of water or any other sul»tance.
In order to make them strictly comparable to the fixed alkalis, they require, like am-
monia, the addition of HK) to their formulse : l^ey may then be considered as hydrates
of compound radides analogous to ammonium. A few alkaloids, however, are known
which, when dehydrated as far as possible, correspond precisely to the fixed alkalis ;
e.g. hydrate of tetrethylium, C»H"NO = C«H»N.H.O. These bodies, for the most
part, resemble potash and soda very dosely in properties.

The constitution of most of the artificial alkaloids is tolerably well known. The
processes by which they are obtained show that they must be considered as ammonia,
or as hydrate of ammonium, in which the hydrogen is replaced wholly, or in part, by
8 compound radide generally composed of carbon and hydrogen (see Amidss, Ax-
MONiUM-BASBs). The phosphorus, arsenic, &c. alkaloids are similarly relat^ to
phosphide, arsenide, &c. of hydrogen, PH",A8H*, &c The constitution of the natural

ALKALOIDS.

121

alkala'di xb^ as jet, Terf imperfecUj understood. They are probably, like tbe artificial
alkalii^ denvatiTes of ammonia; but it is unknown by what radides the hydrc^en is
xiqdseed.

The following is a list of the most important nitrogen-aJkaloids, natural and arti-
fieia], which are now known.

1. Alkaloids comparable to ammonia, forming salts by direct union with adds.

Aeediamine
? Aoetonine
Aeetjlaznine.
Aeonitine
Alanine

Alkabid
Alkaloid

Formula.
. C*EP]SP

(See YDrsuaaim.)

. CH'NO'

jUkaloid
Alkabid
AlHamine .

Bihzomdiallylamine .

Ethjidibcomdialljlamine
Amazine

Dieihylamazine .
Ammdine
Amylamine • • .

IMamylamine

Biethylamylamine

Hethylethylamylamine

Triamylamine .
Ajiiline. (See Fhsntlaionb.)
ABiaine
Aridne

0»ff«NO

C"H"NO

(XB'N.

OH'Bt'N

C«BP«Br«N.

0»H»N«.
C»H*N»0
C»H'«N.
C"H»N.

C"H"]Sr.

Source or Mode of Formadon.

. Acetamide heated in hydrodiloric add gas.
. Action of ammonia on acetone.

. Aconitum NapeUus.

. Hydrochloric and hydrocyanic acids on

aldehydammonia.
. Nitrous ether on creatine (Bessaignes).
. Di8tillationofethylcyanamide(Cahours

and Cloez).

> From aldehydammonia (B a b o).

. Tribromide of allyl on ammonia

. Potash on hydrobenzamide.

. Strong adds or alkalis on cyanamide.

Atrapme
Asonaphtylamine
Aaophenylamine
Bebinne

Benzidine

Boberine
S^ndne

Ethylbrudne

C«HWO«
C»H"l!nO*

C"H»«N» ■

. C«H»NO*
. C»H«»N«0*.

Caffeine .... C^^«N<0«
OajaoyUmine. (See HExruLiazra.)
Capiylamine. (See OcrrLAJiizaL)
Cirbomide. (See Ubba.)

^*">^f yl*™™^^ or > c«jp70N»
Cjantriphenyldiamine . )

Carbothiii&ine . . . Ciff-liPS'

• Action of heat on anhishydramide.
. Cinchona bark.

. Asparagtts officinalis^ and other plants.
. Atropa belladonna, Ikttura Stramonium,
. Keduction of dinitronaphtalene.
. Beduction of dinitrobenzine.
. *' Bebeent," a spedes otNectandra, British
Gxdana.-

. Bedudng agents on azob^ndde and on

azoxibenzide. •
. JBerderis vulgaris,
. Sirychnos nux vomica^ 8, Ignaiii, &

Colubrina,

• Tea, coffee, &c.

. Bichloride of carbon on phenylamine.
• Sulphocarbonic anhydride on aldehycU

Cetylamine.

Tricetrlamine .
? CSididonine
Cindionidne

Cindumidine

Methyldnchonidine
Cinchonine

Uethyldnchonine
Codeine . •

Ethyloodeine

C«H"N.

C»H»»N»0«

C"H"N*0

0«H"N»0

C"H»*N»0
C"H»N«0.
C"H"NO»
C«H»NO«.

ammonia.

. Chelidoniitm mt^'iu.

. Isomeric transformation of dnchonine or

of dnchbnidine.
. Cinchona bark.

. Cinchona bark.

. Opium.

122

ALKALOIDS.

Name.

Colchiceixie .

Gollidine

C!onhydiine .

Conine
Ethyleonine
Hetnyloonine

Gotamine

Conmaramine

Creatine

Creatinine •

Ciyptidine .

Cuinidine •

Cjranamide .
Amylcyanamide
Diamylcjanamide
Diethylcyanamide
Ethylcranamide
Metnylcyanamide
Hethylethylcyanamide

Cyanetfaine .

(^anetholine

Formula.

Cyaniline

Cyanocmnidine .
C^anomelamine .
C^ranotoludine

Diphenine •
Diphenylformyldiamine

Ethylamine .
Biethylamine .
Triethylamine .
Ethylenamine .
Bie&iylenamine .
Phenylethylenamine
(orDiphenyUbiethyleni
Triethylenamine

Flavine •
Fuiforine

Glycocoll
Glycosine
Glyoxaline .
Oiianine

Hannaline .

Hydiocyanhannaline
Sannine • •

Hexylamine.
Trihezylamine .

? Jervine
Lepidine

Leucine

Lophine
Lntidine

Melamine

. C«H**1TO»>
. C^"N
. CfH>'NO
. C«H"N
. C»«H>*N.
. OTBP'N.
. C>*H"NO«*
. 0»H^0»
. C*H»N»0«
. C*H»N»0
. C»ff»N
. 0^»«N
. CH«N»
. C^»»N«.
. C"H«N«,
. C»H>«N».

. o»Bra«.

. C«H<N*.
. C«H»N».
. C»H»*N«
. C«H»NO

. C^ff^N*

. C»H*N<
. C»H>«N»
. C"H>"N«

. C»«H»«N«
. C"H»«N»

. C*H»N.
. C«H"N.
. C«H»N« >
. C*H»*N« J
. 0»H«N . )
amine C»«H:»«N»?{

aoaw or Mode of Formation.

Colckieum autumnale,
. Bone-oiL

. Hemlock (Conium fnaeulatum),
. Hemlock {Conium maculatum).

. Oxidation of narcotine.

. Redaction of nitxo-coiimarine.

. Jnioe of flesh.

. Action of acids on creatine.

. Coal-tar.

. Beduction of nitro-comine.

. GafieouB chlor. of cyanogen on ammonia.

. Fotasaimn on cyanide of ethyL
. Chloride of cyanogen on ethjlate oi

Bodium.
Do. on phenyUunine

(anuine.)
Do. on comidine.

Do. on melaniline.

Do. on toluidine.

. Redaction of dinitrazobenzide.
. Chloroform on phenylamine.

. C"H»»N«0
. C»»H»«N«0«

. C«H»NO«
. C^«N«)
. 0»H*N«J
. C»H»N»0

. C"H»«N«0
. C»«H'*N«0

. C»H>W

. C^H^^NW
, C»«H*N'

. C^'«NO«

. C"H>«N"
. C'H'N.

. Bromide of ethylene on ammonia.

. Bromide of ethylene on phenylamine.
. Bromide of ethylene on ammonia.

• Redaction of binitrohenzophenone.
. Forforamide, boiled with potash.

. Ammonia on chlor- or bromacetic-acid.
. Ammonia on glyozaL
. Qoano, &c

. Seeds of jRyantMnJSTafma^
. Hydro(gramo add and hannaline;
. Seeds of PegoMim Hartnala ; also oxida-
tion of hannaline.

. Solphite of ananthylsodiom distilled with
lime.

. Verairum album, white hellebore.

. Coal-tar; also qoinine and cinchonine

distilled with potash.
. Hydrochloric and hydrocyanic acids in

▼aleral ammonia.
. Distillation of hydrobenssamide.

• Bone-oiL

• • . CH'N' . Action of heat on cyanamide.
• According to unpubliibed analjrtet by Matthietsen and Fofter.

Meoiplitli^laiiiine .
Xetfaylamxne

BimethTlainiiia .

Tnmethjlamixie.
Xtthyhnsmiiie

Xetdmdine .
XoiphiDe

BuiTlmoipliixie .

Keujlmoiphine

Kaf^tylamioe

EthjlnapthTlamme
Nuoeuie •
Naiootine

Kluplitylainiiie .
Oetylimiiie .

FipfTCTIiC •

PuTQline

Pdosiiie, or CisMmpciline

Pheojlamine
AxDjlphenjIainiiie
DiamylphenyUunine
Dicthjlphenylamine
Bioetylphenylaiiuxie
Cety^enylamme
EthylamylphenTlJimme
Ethylphenylamine
Xethjlamjlphenylamiiie
Methylethylphen^lamme
Hethjlphenylamine
Xxxpoeiiylaimne .

TmylphenyUmine
(FhenyUcetylaxmne

Fbtilidine .• •
PiooIijM
Piperidine . •

Amylpiperidine .

£UiTlpiperidme .

Meuylpipeiidine
fPiperme , .
fto^Iamine. (See
^noine

Qnnidiie

Qonidine
Qnimne

Etbylquimne

H^liylqiiiiiiiie .
Qoiiioleuie .

Amyltjuinoleiiie •

Etliylquinoleiiie

Hetfaylqainoleino

ALKALOIDS.

Formula. Sonrca or Mode of Fonnatlon.

123

. C»BP*N»
. CH»N.

. C»H"NO».

. 0»H"NO'»l "P^™-

Gyananilide (cyanophenylamine) and

phenyUunine.
Gnloriae of cyanogen on naphtylamine.

Creatine or creatmine heated with oxide

of mercniy.
Chloride of cyanogen on tolnidine.
Opinm.

Bednction of nitronaphfylene.

Tobaooo.

Bednction of dinitronaphtylene.

. C"H«N

. C*H«NO«
. C"H^

. C»H«NO«
. C'H'N.

. C»«H«^.
. C»«H»»N.
C^H^N.
. C«H*N.
. C"H«N.
. C»H"N.
. C«H»*N.
. OB^N.
. C^-N.
. C»H>*N

• Opium*

. DistiJlat of bituminous shale of Dorset-
shire.
. Cisaamj^doB pareira, L. (Antilles).
. Beduetion of nitrobenzene^ &c

(C^»N.

or
C»«H'"N«
C«H»N .
C^'N.
C»H"N
C>*H«N.
C^"N.
C^'«N.
C"H*N«0«

. C»H*N«0»

. Sulphite of cinnamyl-ammonium distilled
with lime.

. Bednetion of nitrophtalene.

. Coal-tsr.

. Fipexine distilled with potash.

. Pepper (Piper mgnm^ P. longum\

• Bone^nL

• Isomeric transformation of quinine, or of
qninidine.

. C"«H»NK)*.
. C»»H«N«0».
. C^'N.
, C^ffrN.
. C"H"N.
• C»«H«!N.

Quinine or Cinehonine distil with potash.

* According to unpublbbed analrset by MatthieMen nod Foster.

124

ALKALOIDS.

N«ne«

Sarcine
Sarcocdne
Sinamine
Ethylfiinamme .

Sinapine
Sinapoline • •

Sincaline .
Sparteine

Stiychnine •

Tetrylamine (Fetimne)

Thebaine

Theineu (See CAnoMB.)

Theobromine

?Xliiacetonine

Thialdine • •

Thiosanime •

Ethvlthiosanimine .

Toluidine (Toln^lamine)
Biethyltolnidine
Ethjltoluidine .

Tritylamine .

FormuUu
. C»H*N*0

. OH«N«
. C»«H"NO«
. C»H'«NO
. C«'H«N«0«

Off»N
C"HnNO»

0»H>»NS*
C«H>«NS*
C*HWS
C«H>«N«S

CR*NH).

Urea (Carbamide .
Alljlurea . . .
Amylnrea .
Diallylurea. (See SmAPOLms.)
Diethylurea . . . C»H»*N«0.
Diphenylurea. (See Fulyimb.)
Ethylallylnrea . . . C«H»»N«0.
Ethylamylnrea . . . C"H»«N«0.
Ethylpipezylnrea
Ethylnrea .
Memylethylnrea
Hethylpipeiylnrea .
Methylures
Naphtvlnrea
Phenylallylnxea
Phenylurea
Kpeiylurea ... . CTB[»«NK).
Supliallyliirea. (See TmofliKAiaNE).
Tolylnrea .... 0»H»«N»0.

CTB[»«N»0.

C«H*N'0.

C*H»N«0.

C'H^^N'O.

C«H«NK).

C»H»«NK).

C"ff*NH).

CH'NK).

Valeraldine .
Veratrine
?Vinylamine .

C»*H«NS«
C«H«N»0
C«H»N

Soorce or Mode of Fonnatlop.

Jnice of flesh.

Baryta-water on creatine.

Oxide of mercoiy on thioainamine.

Ethylthiosinamine heated with hydrate

of lead.
White mustard.
Hydrate of lead in oil of mustard (sul-

phocyanate of allyl).
AUcalis on sinapine.
Spariium soopariwn, L, {Cy tints seopO'

ritu, Linck.)
8tryehno9 nux vonUca, 8, Iffnain, 8, oolu-

brina.

Bone-oil. -
Opium.

Cacao-beans.

Ammonia and hydrosulphnric add on

acetone.
Hydrosnlphurio acid on aldehydam-

monia.
Ammonia on snlphocyanate of allyl (oil

of mnstard.)
Ethylamine on snlphocyanate of aUyL
Bedoction of nitiotolnene.

I^rdrosnlphnric acid on Tsleral ammonuL

Verairujn album.

Chloride of ethylene on ammonia.

2. Alkaloids comparable to hydrate of ammoninm, fanning salts by combining with
adds and eliminating water.

Name.

Formala.

Amylinm.

Hydrate of Methyldiethylamylinm C»*H»NO.

Tetramylinm C*H*»NO.

Triethylamylium C»H«rNO.

Brudnm.
Hydrate of Ethylfamdum

C»H«N«0».

ALKALOIDS. 125

Formuln.

ConiimL

Hydrate of Biethylconiiim C^^^^O.

Methylethylooniixm C»H"NO.

Et^leniimi.

HydzateofTrimethylethjlemum C^ff^O.

Ethrliain.

Hydrate of Methyltrieihyliiim (?H»KO.

Tetrothylium C^"NO.

Metbylinm.

Hydrate of Tetramethylium OH^'NO.

NiootiimL

Hydrate of Ethylnicotiiim (7H"N0.

Methylnicotiran C»ff>NO.

Fhenylinm.

Hydrate of Ethyltriplienyliiiiii C**H*«NO.

^ MethTlethylamylophenylinm . . . C"H*»NO.

Trietiylplienylium C"H«'NO.

Pipenyliimi.

Hydrate of IMethylpipeiyKum C^"NO.

Pyridine.
HydiateofEthylpyridlne CH^'NO.

Stryehniixm.

Hydrate of Amylstrydmium C*^"NK)».

Efchylst^dminm 0"H«N»0*.

TdTlium.

Hydrate of

TriethyltolyKum C»*H»NO.

Tliere axe some sabstancee not induded in tHe aboYO list^ sach as acetamido,
CH^KO, acetonitrile, U*il"N, &a, vhich poaaefls the most important properties of
alkaloids to quite as great an extent as some of the bodies there enumerated, bat
vfaich, in moat of their relations, are associated with other well defined groups of com-
pounds^ and are in consequence seldom classed amon^ alkaloids. On the other hand,
this list contains some bodies, such as urea and its deriTatiTea, which also find their
places in other daases, but which had long been regarded solely as alkaloids before
their relations to other compounds were disooyered. This inoonsiBtency is unaToidable.
There is not in nature any sharp distinction between alkaloids and other substances ;
henee, in determining whether particular bodies ought, or ought not, to be classed as
alkaloids, we must sometimes decide by reference to customaiy usage, or other circum-
stanees equally arbitrazy. — G. C. F.

AttaloidSp deteettoB of* In elieiiileo-laffttl lawestlirationi. — The certain
detection of the poisonous alkaloids in chemico-legal inyestigations involyes their sepa-
ration, in a state of purity, &om the substances with which they are mixed. When,
as is oAen the case, a yeiy small quantity of an alkaloid is contained in a laige quan-
tity of a oon4>licated mixture of animal or yegetable matter, its accurate separation
is a problem of considerable difficulty. The first chemist who gaye a systematic
method of proceeding in such cases was Stas (Bulletin de I'Acad^mie Boyale de M^e-
cine de Bdgiqae, xi. 304 (1861) ; Ann« Ch. Pharm. Ixxxiy. 379 ; Phaim. [3] xxii.
281% and vie method which he proposed continues to be the one most generally
employed. His process consists in the successiye and systematic use of yarious
solvents, such as dilute acids, alcohol, and ether.

The method of canying it out is as follows : When an alkaloid has to be sought for
among the contents of the stomach or intestines, the substances to be examined are
tzeated with twice their weight of pure absolute aJoohol, to which from 0'5 gramme to
2 grammes of tartaric or oxalic acid (the former is preferable) haye been added, and
the niixture is heated in a flask to between 70^ and 75^ G. (When an entire organ,
such as the liyer, heart, or lungs, has to be examined for an alkaloid, it must first be
diiided aa finely as possible, then moistened with pure absolute alcohol, squeezed, and
afterwards washed with alcohol till all the soluble constituents are removed. The
liquid thus obtained is treated in the same way as a mixture of suspected matter and
alcohol.) When quite cold, the mixture is filtered, the insoluble part washed with
strong alcohol, and the alcoholic solution eyaporated either in yacuo, or in a rapid
nurent of air at a temperature not exceeding 35^ C.

If the residue left on eyaporating the alcohol contains fat or other insoluble matter,

126 ALKALOIDS.

it must be filtered agam throngh a filter wetted with distilled water, the filtrate must
be evaporated nearly to dryness in yacao oyer sulphmic add, and the residue ex-
hausted with cold absolute alcohol. The alcoholic solution is once more evaporated
at the atmospheric temperature, either in the air, or better in vacuo, and tiie acid
residue of this evaporation is dissolved in the smallest possible quantity of water. To
the solution so obtained, pure, powdered acid carbonate of potassium or of sodium is
added very araduaUy until there is no more effbrvescenee. The neutralised solution
is shaken with from four to five times its bulk of pure ether, and then allowed to settle.
When the layer of ether has become perfectly dear, a little of it is decanted into a
glass capsule, and left to spontaneous evaporation in a very diy place. I^ after the
evaporation of the ether, disht streaks of liquid appear on the side of the capsule,
and run together slowly to we bottom of it, a liquid and volatile alkaloid is probably
present, fi this be the case, the warmth of the hand will be sufficient to cause the
contents of the capsule to exhale a disagreeable smell which, according to the nature
of the alkaloid, is more or less sharp, choking, and irritating. If these indications
are wanting, the alkaloid, if anv is present^ is probably solid and non-volatile. Ac-
cording to the nature of the alkaloid, as indicated by this preliminary trial, Stas
recommends different processes for its farther purification.

A« 7%e alkaloid is liquid and volatile, — In this case 1 or 2 cub. cent, of strong
solution of caustic potash or soda are added to the contents of the flask, from which
the small quantity of the ethereal solution was taken, and the whole is again well
shaken. After standing for a suffident time, the ether is poured of^ and the residue
is again shaken three or four times with fresh quantities of ether. The ether^
liquids so obtained, containing the alkaloid in solution, are united and shaken with
1 or 2 cub. cent, of a mixtmre of 4 parts by weight of water and 1 part of sulphuric
acid ; after being allowed to stand, the ether is poured ofi^ and the add liquid is
washed with a second quantity of ether.

As the sulphates of the volatQe alkaloids are soluble in water, but almost all
insoluble in eUier, the alkaloid sought is contained in the dilute sulphuric add, in tha
form of pure sulphate *, while the animal matter which the ether may have taken up
from the alkaline liquid together with the alkaloid, remains still dissolved by it

In order to obtain the alkaloid from the solution of its sulphate, the latter is mixed
with a strone solution of caustic potash or soda; the mixture is well shaken, and then
exhausted with pure ether, which dissolves the alkaloid together with ammonia. The
ethereal solution is allowed to evaporate f at as low a tmperature as possible, and
in order to remove from the reddue the last traces of ammonia, the vessel containing
it is placed for an instant in vacuo over sulphuric add. The alkaloid then remains
in a state of purity, with its characteristic chemical and physical properties.

B. The alkaloid is solid and fixed,— Ji on evaporating a small quantity of the ether
with which the Uquid neutralised by acid carbonate of sodium has been mixed (see
above), there is no sign of the presence of a volatile alkaloid, the liquid must be fiu>
ther examined for fixed alkaloids as follows. Caustic potash or soda is put into the
flask containing ether and the neutralised solution, the mixture is again vigorously
shaken, the ethereal layer is poured off as soon as it is clear, and the wateiy alkaUne
liquid is several times washed with a oondderable quantity of fresh ether. The ether
now contains the free alkaloid in solution ^, and on evaporation leaves either a solid
residue or a colourless milky liquid containing solid particles in suspendon. The
smell of this residue is disagreeably animal, but not shaip ; it colours red litmus-
paper permanently blue.

In order to obtain the alkaloid in the crystalline state, a few drops of alcohol are
poured into the capsule containing it and allowed to evaporate. Usually, however,
it is still too impure to crystallise in this way. When this is the 'case, a few drops of
water made very slightly add by sulphuric add, are poured upon the residue left by
the evaporation of &e alcohol, and made to come in contact with the whole of it by
properiy inclining the capsule in various directions : the alkaloid is thus diasolvea,
while the fatty impurities remain adhering to the capsule. The acid solution, which,
if the last operation has been well performed, is dear and colourless, is poured ofi^ the
capsule is washed with a few drops more of the acid water, the washings are mixed
with the first solution, and the whole is evaporated over sulphuric acid to about
three quarters of its bulk. A saturated solution of pure carbonate of potassium

* Solpbate of eemine being not quite insoluble In ether, a little of thlt alkaloid maj remain In the
etherMU solution ; the greater part, however, is always in the aqueous add solution.

t \t amine be present, a great part of it will evaporate with the ether.

i ir menkme has to be sought for the liquid should be shaken with ether t'mmediatefy after being
neutrallsetCwith carbonate of sodium, and the ether should be poured off as quickly an possible, for. If
the alkaloid have time to separate in the crystalUoe form, scarcely any of it is dissolved by the etlier.
(Otto.)

ALKALOIDS. 127

11 added 10 the TCmumng liquid, and the mixtnre is trented with absolute alcohol,
vfaich disBolTee the liberated alkaloid, but leaTea undisaolyed the sulfate and
exeees of carbonate of potaasium. On evaporating the alooholic solution, the alkaloid
is obtained carTstallise^ and in a state to snow its cfaaraeteiistic reactions.

According to Otto (Ann. Ch. Pharm. c. 39) the above process of purifying the
fixed alkaloids may be advantageoualY modified as follows. Instead of decomposing
the impure tartrate oar oxalate bj acid carbonate of potassium or sodium, and m)tain-
ing a solud)(Mi of the free alkaloid in ether; as deeeribed in the first part of this
azlLcle, the salt dissolved in a small quantity of water is washed with ether, as long as
^ ether is ocdoored by it and leaves a residue on evi^poration, and aftervoards the
fidntion is neutralised bj carbonate of sodium and ether added to dissolye the
alkaloid as already described. On evaporating the etheceal solution thus piepaxed,
the alkaloid is left in a state of ^reat purity. Or, the aeid sulphate of the alka-
loid maybe £xmed and washed with ether, as in the process for purifying a yolatile
alkaloicL

Another method of detecting; and separating the oij^nie alkaloids from mixtures of
other substances has been given by Sonnenschein (Ann. Gh. Phaim. ciy. 45).
This method is founded upon the property which the alkaloids possess, in common
^th ammonia, of giving precipitates in an acid solution of phosphamolybdate of
tpdhtm : it is yery easy cdf execution, and seems to give ygpj accurate results.

Phosphomohrbdate of sodium is thus prepared. The yellow precipitate obtained
bj mixing acid solutions of molybdate of ammonium and phosphate of sodium is
^1 washed, suspended in water, and heated with carbonate of sodium tUl it is
completely dissoWed. The solution is evaporated to dryness, and the residue ignited
till all ammonia is expelled : if any reduction of molybdic acid take place during
the ignition, the product is moistened with nitric add and again ignited! It is then
heated with water, nitric acid added till the solution has a strongly add reaction,
and the gold-yellow solution thus obtained is diluted till 10 parts of the solution
contain 1 part of solid residua It must be carefully preserved from contact with

This reagent is applied to the separation of the alkaloids in the following manner.
The whole of the organic matter to be examined is repeatedly exhausted with yery
difaite hydrochloric add : the extract is evaporated at a heat of 30^ C. to the consis-
tence of a thin syrup, then diluted, and leit for some hours in a cool place before
filtration. The filtrate is predpitated by excess of phosphomolybdic acid, the predpi-
tate collected on a filter, uiorougfaly washed with water containing phosphomolybdic
and nitric adds, and introduced while moist into a fiask. Caustic baryta is added,
to a distinct alkaline reaction : and the flask having been fitted with a deliveiy-
tube which is connected with a bulb-apparatus containing hydrochloric add, heat is
gradually applied, when the ammonia and yolatile organic bases distil over, and are
collected in Uie hydrochloric add. The residue in the fiask (containing the non-
yoimtile alkaloids) is freed from excess of baryta by a current of carbonic anhy-
dride, carefully evaporated to diyness, and extracted with strong alcohol. On
eraporating the alooholic solution, the bases are commonly obtained in a state
of such parity that tiiey will at once exhibit their characteristic reactions : occa-
sionally, however, they require to be farther purified by recrystaUisation from alcohol

A process has been employed by Graham and Hofmann (CheuL Soc Qn. J. v.
173 ; Ann. Ch. Pharm. Ixxxiii. 39; Pharm. J. Trans, xi. 504) for the detection of
strychnine in beer, which might doubtiess be employed with equal advantage for the
detection of other alkaloids in large quantities of liquid. It consists in leaving the
liqaid to be examined in contact with about a fortieth of its weight of good animal
chflzcoal for a day, the whole being frequentiy shaken, collecting the charcoal on a
filter, washing it once or twice with water, and then boiling it for half an hour with
aleobol, which dissolves out the alkaloid. The alcoholic solution is evaporated,
the residne is made alkaline by the addition of a few drops of potash or soda, and
then shaken up with ether, wUch, when poured off and evaporated, leaves the oi^ganic
base with its characteristic properties.

Schulze (Ann. Ch. Pharm. dx. 177) has indicated the add liquid obtained by
dropping pentachloride of antimony into aqueous phosphoric acid as a very delicate
reagent far certain alkaloids, and as a substance which may probably serve for the
separation of the alkaloids in general

When an alkaloid has been separated in a state of purity by one of the above
processes, or hr any other, its chemical and physical properties must be carefully
observed in order to determine its individual character, and the reactions obtained
sbrmld in eveiy case be controlled by comparison with those given by a pure speci-
men of the substance suspected.

128 ALLANTOIC AND AMNIOTIC LIQUIDS.

From what has been stated above relative to the abeoiption of the alluiloids bj
animal chaicoal, it is evident that that substance shonla never be employed to
decolorise a solution previous to its being examined for poisonous organic bases. The
emplovment of baflic acetate of lead for the same purpose rtiould also be avoided,
since it not only introduces a poisonous metal into the substance to be examined, but
the sulphuretted hydroeen, which is required to remove the lead, is apt to combine
with some of the organic matters present, forming compounds which, in contact with
the air, give rise to highly coloured and disagreeably smelling products, veiy difficult
afterwards to get rid of. (St as.)

For further detals concerning modifications of Stas*s process, and for some methods
which are not mentioned in tms article, the reader is referred to the article on tibe
same subject in Liebig, Poggendorff, and Wohler's ** Handworterbuch der reinen nnd
angewandten Chemie," 2naedition, i 464 ; and for the reactions of the individual
alkaloids, to the various articles in thia Dictionary in which they are specially de-
scribed.— G. C. F.

IT. The commercial name of two different plants. Ihis alkanet oon-
sists of the leaves and roots of the Lawaonia inermis^ which grows wild in the Levant.
The leaves pulverised and made into a^ paste with water yield a yellow dye. The
root, which contains a red pigment, is used aa a cosmetic

False alkanet (Orcanette, Radix alcanna spurus) is the root of Anchusa tinc'
toriOy which grows in France, Spain, Italy, Hungary and Greece. It is inodorous,
has a faint^ somewhat astringent taste, and colours the saliva. It is uaed in dyeing
to produce a very brilliant violet and a grey ; and for this purpose, linen or cotton
goods previously prepared with alum-mordants for violet, and with iron-mordants for
grey, aro dipped in an alcoholic extract of the root. It is also used for dyeing silk,
but not for wooL The colouring matter is called Anchusin (which see).

and AULAS8ZW. (See Arsenidbs of Mbthtl.)

A mineral which appears to be an intimate mixture of homstone
and silicate of manganese, perhaps also with carbonate of manganese.

Syn. of DiopsiDB and Auoitb.

(See Obthttb.)

A&&AVTOZO and ABCVZOTZO XiZQinEDS. The fcetus of most mammi-
ferous animals is enveloped in two membranes, the outer of which is called the
allantoiSt and the inner the amnittm. The space between the two is connect'Cd by a
duct with the urinary bladder of the foetus, and contains a liquid called the allantoic
liquid, which is in fact the urine of the foetus. The amnium at first lies close upon
the foetus, but gradually separates and becomes filled with a liquid in which the
foetus floats suspended by the umbilical cord. This liquor is the liquor amnH.

The allantoic liquid is especially distinguished by containing alfantoin, together
with albumin, alkaline lactates, chloride of sodium and phosphates, and sometimes
glucose. The amniotic liquid contains albumin, pyin, a substance rosembling mucus,
extractive matter, and in some instances glucose, together with alkaline dilorido,
sulphates and phosphates.

These liquids have been investigated by many distinguished chemists, but the most
exact analyses of them are those which have been recently made by Schlossberger
(Ann. Ch. Pharm. xcvi. 67, and ciii. 193), and by Majewski (Dissert, de Substan-
tiarum, &c, Dorpat, 1858; J. fur Chem. Ixxvi. 99). Majewski's results are as
follows :

Both liquids, in the earlier stages of development of the embryo of cows and sheep,
are clear and colourless : at a later stage, the amniotic liquid of the cow becomes
gummy and yellowish, also turbid; in sheep and swine on the contrary, it alwavs
remains clear and colourless, and never becomes gummy. The allantoic liquid
becomes yellower with age, and at last reddish yellow, but remains dear, excepting
in swine, in which it is always turbid. Both liquids generally exhibit an alkaline
reaction.

In both liquids, the solid constituents, organic and inorganic, increase for the most
part in quantity as the development of the foetus progresses. In the human foetus, how-
ever, the quantity of solid matter in the amniotic liquid decreases considerably towards
the time of birth (see table). The same result was obtained by Vogt and by Scherer.
the latter of whom found 2*416 per cent, of solid constituents in the amniotic liquid
in the fifth month of gestation, and only 0*852 at birth.

The amniotic liquid retains its albumin up to the period of maturity of the foetus,
but (as appears tram investigations on the numan embryo) this amount decreases in
the later period of the development of the embryo, and this diminution appears to be

ALLANTOIC AND AMNIOTIC LIQUIDS.

129

eaooeeted with the fonnation of the placenta. In the amniotic liquid of the cow, the
albumin may be recognised l^ its orainary properties in the earlier sta^ of derelop-
BMDt, but afterwardB the liqnid becomes gummy and no longer exhibits the nsnal
medon vith nitric acid. The same result was obtained by Schlossbeiger, (p. 130).

Hie allantoic liquid increases in quantity and consistence as the development of
the onlnTO adTanoes ; it is always dear (excepting in swine) and resembles saturated
vnae. the allantoic liquid of swine contains iron and a peculiar compound of lime
and albnmin.

In both liquids^ the quantify of sugar gradually increases from the earliest period
of fietal life, and is greiftest a short time before birth. Sugar appears however to be
nreseat only in the yegetable feeders : in human embryonic liquids it cannot be

Hie quantity of inorganic salts increases as development advances. Both liquids
OQotain chlorides, phosphates and sulphates, the quantity being greater in the
aSanftoie than in Uie anmiotie liquid.

Tbe following table exhibits a summary of the quantitative results obtained by
Majewski:

In 100 parts.

-" — ^

Bjasi-.

AjBlte

cmc

9p«.

Warn.

tiolid
nil».

Or-
■aale.

Inor.
gaale.

Alba-
Bin.

SofV.

UfMU

FlOA

S08

W*«

{

1-00S9

99-357

0*649

0*459

0*184

0-14S

» 4-«l

{

AltaDMb

19
69

1-0018
1006d

99^460
98-900

0*540
1*010

0*400
0-650

0-140
0*370

0*105

0-063
0-141

0*10
0*40

0*0047

0-0051

. H-9

Amta

i-ooi;
i-OOik

98-945

m-i«7

1-055
1-878

0*685
1-198

0-370
0*675

0*115

0-114
0*449

0-301
0*500

0-0078
0-0356

0-0061
0-0069

• l»-lt|

AI^Mofc

163
119

1-0069
1-0100

96-515
97-453

1*485
1-547

0-917
1-671

0*568
0-876

0-170

0-171
0-641

0-370
0606

0-0148
0*013?

Oi)034
0-0x75

m 111-18

Aranta

6S7
835

1-0064
1-0097

98-660
97-380

1*349
1*6S0

0-905
0-960

0*435
0*660

0*S41

0-196
0-667

0-475
0*780

O-0817
0HM98

0-006
0-OSK

. »-is

Amain

AJlMMQii

675
9S

1-0047
1-OlOk

98-97P
97-310

1*03
1*69

0*600
1*800

0*430
0*890

0*091

0-104
0*555

o-mo

0*330

0-018
QrOm

0*009
0-033

dCmm,

m H-tt

ABWiM

1«U
643

1-0064
1-OlU

98*554
98*858

1*446
8*148

0*876
S-S38

0-570
0-804

0-097

0*191
0*605

0-198
0*645

oa&i

0*011

0-011
<h097

» SI— 17

AlbmMfe

699
ISM

1-0076
1-0163

98-076
96*160

1-9M
3*840

1*171
S-767

0*753
1-073

0-115

0*301
0-648

0M16
0*857

0*016
0-038

OK>n
0-llS

i55L{

lateMlBM

■eh

1-0049

95-405
98-490

3-595
1-510

0*95

5*600

9*188

0-357

0*380

5!s:{

A-nfaw

60
19

1-0064
f0096

98-114
97*580

1-886
MIO

1*148
1*705

0*638
0*715

0*561

trace
naec

0*140
0*858

SehloBibager found in the embryonic liquid of cows the following quantities of
water and inorganic salts : — The ages oi the foetus were : of (a) 30 weeks ; (6) 18
weeks ; (c) 16 weeks ; {d) 7 — S we^ ; (e) 5 weeks, and (/) 3 weeks :

Water.

Aib.

Soluble
Salu.

Insoluble.
SalU.

97-18

97-28

0-72

0-694

0026

Amniotic

98-96

1-02

100

002

liquid.

98-67

0-89

0-86

003

9812

I11«««MJ> ! ^'

97-33

0-93

0-91

0-02

liianiDie
liquid.

98-76
97-36

0-73
0-71

0-70

003

The liqaids, even in the fresh state, exhibited an alkaline reaction, and effervesced
bri^ly with acids : and they all exhibited the reactions of sugar, the amniotic liquid
of tf containing 0*092 per cent, of that substance, and the allantoic liquid of the same,
0-464 per cent Schloesberger did not find urea in the amniotic liquid.

The albmninoidal substances of both liquids exhibited differences of character
amcMigprt themselves, and many unusual reactions, indicating the presence of com-
pouids intermediate between albumin casein, mucus and pyin. The reactions ob-
served by Schloesberger are giren in the following table:

V0L.L K

ALLANTOIC AND AMNIOTIC LIQUIDS.

boiling wid
on^dditiM.
ofacatioacid.

Amniotic liquid of a and i;.

Allantoic liquid of* and a

0. Vitdd like vliito of egg :
mixed easily witli vakr, and
Bltered readilj. On boiling,
became mora mobile, vith
Bcarcel; perceptible tnrbidit;.

bidilj, the liqmd renmining ™-
cld. Od boiling, small flocks

the protein-substance remained
dissolved. On evaporation: Alms.

perfecU? clear when boQed,
either uone or wit^ acetic acid.

6. HotTiwid; clear on boil-
ing. Acetic acid produces
slight turbidity, and redifsolTS)
the flocks but slowly, even in ex-
cess and at the boiling heat.

e, COHgnlatei even vheo
boiled alone, the coagulum being
hut partially soluble in scetie

Both 6 and e beceme Tsty
turbid when boiled with chlo-
ride of CBldum or snlphiil« of

turbidi^ (arising in b most pro-
bably fitjm carbonates) disap-
pesiB on adding acetic acid

Akobol

a. ThroTB dami flocks aolu-
c. No change. '

b. So change.
e. Turbidi^.

Nitric add. .

c. No turbidity. Liquid does
not become yellow on boiling.

_ &. Scarcely perceptible turbi-

c Fiecipitate and yeHov
colour on boiling.

Hga

a. Slight turbidi^: small
flakes on boiling.

c. Turbidity. {WilhNO«Hg:
copious precipitate).

b. No change.

a. Ho change.

c. Turbidity only after addi-

b. Ho change.

c; Aftaaradolatioii:flodw.

AceUte of
lead. Baaic
acetate of letuL
TaimiQ.

Alnm. 1

ir. CH^'C, or CifA-'O".— Discovered by Vanquelin
Buniva (Ann. Chim. zxiiii. 269) in the amniotic liquid of the cow* Lagsai
(Ann. Ch. Phys. [3] ivii. 301) obtained it from the allantoic liquid of the cow,
Wohler (Ann. Ch. Pharm. tix. 220) from the nrine of calves. It is formed
flcially by treating uric acid with water and peroxide of lead. (Liebig and Wiil
Ann. Ch. Pharm. zzri. 244.}

OH'N'O' + ffO + 2FbO - C'H'NH)' + CPVO';

Uilc uld, AUnDtotn. CulMDiita

ollud.
or with a mixture offerricyanide of potassium and caustic potash. (Schl leper,
Ch. Pharm. livii. 216.)
CK'N-O* + SCTS'Fe'^ + 4KH0 - CH-N'O' + CK'O' -i- iOWTeK* + '.

Uriel

Fnilc,«l

PrfparaHon. — Fnlverised uric add is suspended in water, nearly at the boilino; heat,
and finely pounded oxide of lead is added by small portions, and with frequent stirring,
till the last portions no longer turn white. The hquid Sit«red while hot deposits on

lublB tdu the utDlnllTllqiiM wu mliad vlth allutcilc li<)uld. '

ALLANTOIN. 131

(odii^ aptiJB of ftUantoiiii while urea lemainB in solution, and oxalate of lead is
left Qo the filter. The two latter compounds are produced by the action of the excess
ofperazideof lead on the allantoin. (LiebigandWohler.)

<?H«NH)» + 2PbO + H*0 - 2CH*N«0 + C^H)*.

, — — ' "« — , — '

Urea. Oxalate of

lead.

To obtain allantoin from tiie allantoic liquid, the liquid is evaporated to a fborth of
its bulk, and the dyBtals which are deposited on cooling are decolorised with ani-
nal durpoaL From calTes* urine, it is prepared by eTaporating the liquid to a syrup,
and leaTiDg it at least for several days, tnen diluting with water; washing the deposit
vith water to separate a quantity of gelatinous matter, chiefly consisting of urate of
migBsnuii ; boiling the ctystaliine residue of allantoin and phosphate of magnesium
vim vaterand animal charcoal; filtering at the boiling heat; ana addinga few drops
of hjdvocblone add to the filtrate to retain in solution the small quantity of phos-
phate of oagnesium dissolved in the boiling liquid. The allantoin is then deposited in
CTfitdi OB cooling.

Pn^trtm. — ^Allantoin forms shining colourless prisms, having a vitreous aspect, and
bdoq^a^ aoeording to D auber (Ann. Ch. Pharm. had. 68), to the monodinic fiystem.
It is tsBtdesB and without action on vegetable colours. It dissolves in 160 pis. of
viter at 20° C, and in 30 pts. of boiling water. Alcohol dissolves it in larger quantity.

DieompotUicms, — ^By dry distillation, allantoin is resolved into carbonate and cyanide
of ammonium, a small quantitT of empyreumatic oil and a verj porous charcoal When
gat^ heated with nitric or hydrocmoric add, it is converted into urea and allanturic
acid. (Pelouze, Gerhardt)

C*H«N«0" + H»0 = CH*1TO + C«H*NK)«

AllaDtnric acid.

Heated with suljpkurie aeid^ it is resolved into carbonic add, carbonic oxide, and am-
noai^ (Lisbig and Wohler.)

C*HWH)« + SWO « 2C0« -I- 2C0 + INRK

Boiled with btu^^ water ^ it gives off ammonia and predpitates oxalate of barium :

C^*N*0« + 4BaH0 + HH) - 4NH" + 2C«Ba«0^

KBihliy with aqueous potash (LiebigandWohler). A solution of allantoin in
cdd potash depodta all the allantoin unaltered, if immediatdy mixed with adds ; but
intteowiwe of a day or two, it changes spontaneonsljr Into hydantoaU of potasnum
(C*R'JSJS*0*^ and is then no longer predpitated by adds, gives off but Uttle ammo-
ma what boded, and does not form mj oxalic add :

C*H«N*0" + KHO = C^H'KN^O* ;

Ifj the finther action of the alkali, the hydantoate of potassium is resolved into urea
sod la&tanuzate of potassium :

When the aqueous solution of allantoin is boiled with metallic oxides, compounds
are fonned which may be called salts of allantoin. Some of them consist simply of
alkatoin in which 1 at. H is replaced by a metal; thus, the cadmiwnroompouna is
C*HHMKH)* : and the stiver-compound, obtained by mixing a solution of allantoin
with nittate of silver and then wiUi ammonia, is C^H^AgN^O'. But most of them con-
tab an eieess oi the metallic oxide ; thus, the zinc-compound is ZnK).2OH*ZnN*0',
tad the lead-compound Pb*0.4C^H*FbNK)'. Theee compounds are insoluble or
apanojdj soluble in water, and decompose at 100^ or a little above (Limpricht,
Ann. uL Pfaaim. Ixzxviii 94). The silver^compound was obtained by Liebig and
Wohler.

When a solution of allantoin is boiled with excess of mercuric oxide, the filtrate
heoomes milW on cooling, and after a while deposits an amorphous powder containing
Hg«0.3C«H»HgN«O«, or bHgO.ZC*H^N*0^. Three other compounds are said to be
obtained from the mother-liquor. Allantoin does not precipitate corrosive sublimate ;
^ with mercuric nitrate, in a cold and very dilute solution, it forms a predpitate
containing 3H^.4C^H»HgN*0«, or &^y0.2Cffl»JV»0».

On this last property is founded a method for the quantitative estimation of allan-
toin, bj precipitation with a graduated solution of mercuric nitrate. The method is
similar to Liebig's process &r the estimation of urea {q. v,\ but is applicable to
the estimation of allantoin only in liquids not containing urea. To predpitate
100 ams. of diy allantoin, C^H^^, requires 172 erms. of mercuric oxide : conse-
qnentty 10 eab. cent of a graduated solution of mercunc nitrate containing 0*770 gnu.

K 2

132 ALLANTUBIC ACID— ALLOPHANIC ACID.

mercnrie oxide, will pedpitate 0*448 gnn. aOaiitoiiL The liqmd shonld oouUiii a «oii-
ridenble ezoesB oi the mercnrie ealK

CFH^S*0^. — A product of the decomposition of aUmtoiB
under the inflnence of nitric add, hydrochloric acid, or pooxide flf lead (p. ISl}:
also obtained by treating nric acid with, nitric acid or chlorine. It is a white solid
body, slightly acid, deliquescent, neariy insoluble in alcohol, and yields by distilla-
tion a product containing hydrocyanic add, with a bulky residue of chareoaL With
nitrate of silrer and acetate of lead, it forms white bulky predpitates, soluble in
of these salts, and of allantuiic add. (Pelouze, Ann. Ch. Phys. [3] ri. 71.)

sude of Antimony, (p. 871.)

iCM3^ CH'WK)*? Obtained by mixing an aqueous solution of
alloxantin with excess of hydrochloric add, boiling the liquid rapidly down to a small
quantity, treating the pnlremlent mixture of allituric add and undeoomposed alloxaatin
with nitric add to dissolre out the latter, and diasolring the reddue m 15 or 20 pts.
of hot water. The solution on cooling depodts allituric add in the form of a bulky
yellowish white powder. It diasolyes in strong sulphuric add, and is predpitsted from
the solution by water. Its solution in ammonia yields allilurate of ammonium, by
spontaneous CTuporation, in colourless shining needles. The add is deeompoeed \rf
boiling with potash, with erolution of ammonia. (Sehlieper, Ann. Ch. Pham.
ItL 20.)

ASMSUWK SATXVUIC ( Garlic.) 100 pts. of the ash of the fresh plant yield 0*64
p. c ash, containing in 100 parts : 12*17 carbonic anhydride, 4*82 sulphuric anhydride,
2*18 phosphoric anhydride, 35*13 potash, a trace of soda, 2*75 chloride of sodium,
5*74 carbonate of caldum, 6*89 carbonate of magnedum, 30*09 bade phosphate of
caldum, 0*22 silica» and traces of the phosphates of magnedum and iron.

A&&OOHXOITH1 A TBrietj of gamely flne-grained, maadye^ and of dark dingy
colour. (See Gabmbt.)

AUMMMVITB. 8yn. with Heboebtib.

A&KOMOXVKXTa. Breithanpf s name for a mineral from Bndolstadt^ which,
according to the analysis of GFemgross, appears to be merely sulphate of barium.

AUEiOVBAVMi A hydrated silicate of aluminium, of a bkie and sometimes
ffreen or brown colour, occurring masdre^ or in imitatiTe shapes, in a bed of iron-shot
mnestone, or greywadce slate in the forest of Thuringia. It is transparent or trans-
lucent on the ed^es, moderately hard, but yery bri&e. Eracture imperfectly con-
choidaL Lustre vitreous. Specific gravity 1 *89. According to Stromeyo^s analysis, it
contains 21*92 silver, 32*2 alumina, 3*06 ferric hydrate, 0*73 lime, 0*52 sulphate of
caldum, 3*06 carbonate of co^)er, and 41*30 water. Bunsen found in a specimen from
a bed of lignite near Bonn, nearly the same compodtion, with a slight admixture of
the carbonates of calcium and magnedum, but no copper. The minnal appears from
the analyses of Walchner, Berthier, Ghiillemin, and others, to vary oonsidembly in
composition, but irrespective of foreign admixtures it agrees nearly with the formula
A1^.3SiO* + 5HH). Schnabel (Jahreeber. d. Chem. 1850, s. 731), has» however,
analysed seranl allophanes containing from 14 to 19 per cent of oxide of copper.

AXAOV&aVXCAOZB. C^«NK)*-.^^'^'|o. Ureo<arbonie add. (Gm.

ix. 266 ; Gerh. i 418.) By passing the vapour of cyanic add into absolute alcohol,
Liebig and Wohler obtained in 1830 a peculiar ether, which they regarded as cyanate
of ethyl ; but in 1847 (Ann. Ch. Pharm. lix. 291), they discovered that the substance
thus formed was the ether of a peculiar add which they called allophanio add.
This add contains the dements of 2 at. cyanic add and 1 at, water:

C«H^NK)« - 2CB3TO + H«0.

Its ethers are produced when the vapour of cyanic add comes in contact with the
corresponding alcohols, and ti^ese ethers, treated with caustic alkalis, yield the cor-
responding salts of allophanic add. The add itself is not known in the separate state ;
when its salts are decomposed by a stronger add, it is resolved into carbonic anhydride
and urea:

C«H*N«0« - C0« + CH<N«0.

In like manner the salts when healed in the state of aqueous solution, are resolved into
carbonic anhydride, a carbonate, and urea.

AJUophanate of Barium. — Obtained by dissolving allophanate of methyl or ethyl in
baryta-water, whereby wood-spirit or alcohol is set free. The best method is to tri-
turate allophanate of ethyl wiUi ciystals of hydrate of barium and baiyta-water, without
applying heat^ till the ether disappears ; filter from the remaining baryta-erystals ; and.

ALLOPHANIC ETHERS. 133

Ki Mide tbe fflinte for some days in a closed yeesel; the barinm-salt then separates
gradnglty in hard ajBtalline nodules and cmsts. The ciystaJs are separated from
tbe Teasel imder the liq^nid ; the liquid quickly decanted ; any carbonate of barinm
thatmaj have been formed, is sepanSted by elutriation ; and the crystals are washed a
iew tiineB with a small quantity of cold water, and dried on paper at the temperatoie of
the axe

The bannm-salt has an aftaUne reaction. When heated alone, it does not
give off a trace of water, bat erolTes monocarbonate of ammonium, and leaves cyanate
at faaoivKL Its aqueous solution becomes turbid below 10(P G^ giyes off carbonic
anhydiide wil^ eflferreseence, deposits all -the baryta in the form of carbonate, and
afterward* ooastains nothing but urea in solution :

2C^«BaN»0« + HK) = CX)«Ba« + C0« + 2CH*NK),

Tfaas mah, vhen an add is poured upon it^ ia decomposed with brisk effervescence,
yieldbig earbonie anhydride and urea ; even carbonic acid produces this decomposition,
^^Mwg** dowly ; neither cyanic acid nor ammonia is formed.

jSepktinaie of Calcium, — Prepared like the barium-salt, Ciystallisable. Sparingly
aofaible in water.

JBopktmate of PotoMtiuim, — A solution of allophanic ether in alcoholic potash quickly
deposits this salt in laminn resembling those or chlorate of potassium.

MinpkamaU of Sodium, — Obtained like the potassium-salt, or by triturating the
faarimn-salt, without application of heat, with an equivalent quantity of aqueous sul-
phate of sodium, and pouring alcohol upon the filtrate, which causes the sodium-salt to
crystallise out in small prisms having an alkaline reaction. The aqueous solution of
the aalt evaporated without heat in vacuo^ leaves the salt in the form of an iridescent
gelatinous mass ; evaporated between 40^ and 60^ C. it leaves the salt partly unde-
coB^Kwed, partly resolved into urea and carbonate of sodium. The aqueous solution
mixed with nitric add gives off carbonic anhydride and deposits shining scales of
ni&ate of urea. It does not predpitate chloride of barium, in the cold, but^ when
hoatod with it^ fonna an immediate predpitate of carbonate of barium.

-These compounds contain the elements of 2 at. cyanic add,
and 1 at. of an alcohol, monatomic, diatomic, or triatomic^ e.ff,

AUophanate of Ethyl . . . C*H"NH)» - 2CNH0 + (?H«0
Allophanate of mhylene . . C*H!^0* » 2CNH0 + C>H«0*
AUophanate of Glyceryl . . C»ff>NK)» = 2CNH0 + C»H"0«

They are obtained by passing the vapour of cyaaio add into the alcohols.

AUophanate of Amyl, C'ff^N'O' - C*H»(e*H»)NO«.— AmyUc alcohol rapidly
absorbs the vapours poduced by the action of heat on cyanuric acid, the liquid, after
a whDe, solidiQring mto a magma of cxystals, which may be purified by solution in
boiling water. (Schlieper, Ann. Ch. Pharm. liz. 23.)

Allophanate c^ amyl forms nacreous scales, unctuous to the touch, and without taste
or odoor. It is insoluble in cold water, and its solution in hot water is neutral to
vegetable colours, and does not predpitate metallic salts. It is very soluble in alcohol
and in ether, and is predpitated from the solutions by water. It is not attacked by
chlorine, biomine^ nitric add, or hydrosulphuric add. It melts at a gentle heat, and
snblimea without alteration ; but its mdtmg-point is ver^ near that at which decom-
poaition takes place. When heated above 100^ C. it boils, gives off vapours of amylic al-
eohol, and leaves a residue of cyanuric add, 8C»H"N«0« - 8C*H>*0 + 2C»N*H*0«.
DistOled with fixed alkalis, it gives off amyl-alcohol ^Schlieper). According to
Wurtz (Compt rend. xxix. 186), hot potash-ley converts it into carbonate of potassium,
amylamine, ud ammonia :

Crff^NH)* + 4KH0 = 2C0*K» + C»H»«N + NH» + H«0.

Allophanate of Eikyl^aeAttovhanio Ether, C*B?NH)^ » G^C>H')N*0*.— When
the vapours evcdved from heatea OTanuiic add are passed into absolute alcohol,
the Uqoid becomes very hot and gradually depodts crystals of aUophanic ether. The
prodoet is washed with a small quantity of alcohol, then dissolved in a mixture of alcohol
and ether, and left to czystsJiise b^ evaporation (Liebig and Wohler, Ann. Ch.
Fbarm. IviiL 260 ; lix. 291). According to Debus, allophanic ether is likewise produced
by the action of ammonia on dicarbonate of ethyUc disulphide.

AlViphanin ether erf stallises in colourless transjparent needless, having a strong lustre.
It is insoluble in cold water, but dissolves in boiling water and in alcohol, sparingly in
ether. The solutions are neutral to test-papers, have no taste, and do not precipitate
BMtallic salts.

The ether dissolves in ammonia somewhat more freely than in water, and crystallises

X 3

134 ALLOPHANIC ETHERS.

therefrom, apparently free from ammonia. It diBsolyes in dilate salphnne and nitne
acid at the boilinsheat^ apparently -without deeampoaition.

The crystalairlLeii heated in an open veesel melt and Tolatiliae, the Tapoora eofn-
densing in the air in woolly flocks.

Treated with cold alcohoUe potaah or baiyta-water, it yields a metallio allophanate
and alcohol ; with a boiling Bolution of potash, itforms cyanurate of potassium.

Allophanate of I^hyUne,C*B*JPO* ^^^^^Ao^. JUophanate of Glycol.-^

G^lycol (hydrate of ethylene) absorbs cyanic acid vapour with considerable fareei so
that it 18 best to oool the liquid during the absorption. The product is a white mass
which dissolves in boiling alcohol, and separates on cooling in eoloariass iih»"^"g
lamins. It is soluble in water, and melts at 100° G. without decomposition, to a clear
colourless liquid, which solidifies in the dystalUne form on cooling. At a stronger
heat, it gives oif carbonate of ammonium, and a thick viscid liquid, while mnurie acid
remains behind. Strong acids decompose it. With hydrate of barium, it behaves like
the glycerin-compound next to be described; also with alcoholic potash. StRKig
aqueous potaidi likewise decomposes it» without Honnation of cyanuric add. (Baeyer,
Ann, Ch. Pharm. adv. 160.)

Allophanate of Glyoeryl, (m>«N*0» - H^Srl^' ^^^^^^^^f^h'

eerin. — Glycerin absorbs cyanic add vapour, and is thereW converted into a white
stidnr mass, which dissolves in alcohol, leaving only a small quantity of eyamelide.
The hot saturated solution, on cooling, deposits allophanate of glyceryl in hard crusts,
composed of small translucent nodules. The crystallisation is often slow, especially
when much glycerin is present ; hence it is best to wash the crude product with cold
alcohol before dissolving it in hot alcohoL The nodules, ait<er rectystallisation from
alcohol and drying at 100°, gave by analysis 83*6 per cent carbon, (*7 hydrogen, and
16-5 N, the formula requiring 88*7 C, 5*6 H, and 167 N.

Allophanate of glyceryl has neither taste nor smell, dissolves slowly but abundanthf
in water, and wiui tolerable fiadlity in boiling alcohoL Heated in the dry state, it
melts at about 160° C. to a colourless liquid, which solidifies in a gelatinous mass on
cooling. On raising the temperature, a large quantity of carbonate of ammonium is
evolv^ and the mass ultimately turns brown and emits an odour of burnt horn.

It is not decomposed by dilute adds at ordinary temperatures, but strong nitric and
sulphuric acids decompose it, with evolution of carbonic anhydride.

When triturated with water and hydrate of barium^ it dissolves with &cilitf ; but
the dear filtered solution deposits, after a short time, a bulky crystalline predpitato of
carbonate of barium. The predpitation takes place even when the quantity <xF baryta
is less than suffident to saturate the aUophanic add present, so that it does not appear
possible to prepare allophanate of barium in this manner. A certain quantitv of that
salt appears, however, to be formed, inasmuch as the liquid, after long stanoing, still
deposits carbonate of barium when heated. If alcohol be added to the liquid containing
an insuffident quantity of baryta, allophanate of ethyl is produced, probably by a
catalytic action. AUophanate of glyceryl heated with baiyta-water, yields nothing out
carbonate of barium, urea, and glycerin.

In an alcoholic solution of potash^ allophanate of glyceryl cakes together to a stidcy
mass, then gradually dissolves, the solution after a wmle depositing long needles
which gradually change to small bulky masses of needles, apparently consisting of
ethyl-carbonate of pottusium. (B aeyer.)

Allophanate of Methyl, 0»H«NK)» - C*H»(CH^)NK)«.— Discovered by Bi chard-
son in 1837 (Ann. Ch. Pharm. zxiii. 128), and oriffinally called ureo-<:arhoyuUe of
methyl. When cyanic add vapour is passed into metSyl-alcohol, colourless crystals are
obtained, which must be repeatedlv washed with water, and then dried at 100° C. When
heated, they partly volatilise undecomposed, and are partly resolved into ammonia,
methylene gas (?), carbonic anhydride, and cyanuric acid:

30»H«NK)« - 8NH» + 8CH« + 8C0« + CTPIW.

Heated with potash, the^ are decomposed in the same manner as the ethyl-compound.
They dissolve readily in water, wood-spirit and alcohoL especially when heated,
forming neutral solutions.

Allophanate of Eugenic acid, C»*ff*NK)* « CH'CCwff'OJNK)*.— Eugenic
add rapidly absorbs cyamc add vapour, forming a thick msss, whicn dissolves in hot
alcohol and separates in long shining needles on cooling. At 100° C. it gave 67'0 —
67-9 per cent C, 6'7—6-9 H. and 11-3 N (calc 67'6 G, 6*6 H and 11-2 N). It contains
the elements of 2 at cyanic add, and 1 at eugenic add (2CNH0 + C^'H)*), and is
therefore analogous in composition to the allophanic ethers.

It is insoluble in water, sparingly soluble in cold alcohol, abundantly in hot alcohol.

ALLOXAN. 135

It wThihitB itioDg tondeney to erystaUise, so that eyen amall quantities of the aolution
yield needlee of proportionably conaiderttble length. It is very soluble in ether, is
destitnte of taste and smell, has a silky lustre, and is permanent in the air.

Strong adlda decompose it. Triturated wiUi water and hydrate of barium, it forms
a stiff paste, consisting of engenate and allophanate of barium. Alcoholic potash does
not appeiir to oonTert it into allophanate of potassium. When heated, it is resolyed
into eugenic and cyanuric adds. (Baey er, Ann. Ch. Fhsrm. odr. 164.)

See IflOXXBisic

{Mhxanhydride, Laurent.) C*H«N»0*, or C^B^N'O^.

Hittoijf. — Discovered in 1817 by Brugnatelli, who designated it Erythric acid:
first completely inyestigated by Liebig and Wohler, in 1838 (Ann. Ch. Pharm.
zxri. 256); more recendy by Schlieper (Ann. Ch. Pharm. Ir. 263).

ForwutUon and Preparation, — Alloxan is one of the numerons products of the oxida-
tion of uric acid. Its prepantion is a matter of some nicety. Liebig and Wohler
{toe. eiL\ and Gregory (Phil Mag. 1846), prepare it by the action of nitric acid on
uric ada : concentrated nitric add specific gravity 1*4 to 1*42), must be employed, and
Qie temperature must not be allowed to rise above from 80^ to 36° C. The process is
thus conducted. Prom 1} to 2 parts strong nitric acid are placed in a beaker or por-
celain basin, sunounded with cold water, and 1 pt. uric add is added in successive
small portions, with constant stirring, care being taken not to add a fresh portion of
uric add until the action caused b^ the addition of the former portion has quite sub-
sided. Carbonic anhydride and mtrogen are evolved with efieryescence, the action
becoming gradually less violent as the operation proceeds ; and ciystals of alloxan
gradually separate out. When the decompodtion is complete, the mixture is left over
night in a cool place, and the crystalline magma is then thrown on a funnel plugged
with asbestos or coarsely pounded glass, and the last portions of the mother-liquor are
carefully removed by washing with ice-cold water, till the washings have only a faintiy
add reaction. Schlieper recommends removing the alloxan as it forms, in order to
withdraw it from the further action of the nitric acid. The crystals of alloxan are
dried by standing on filtering-paper or a porous tile, and then purified by solution in
the smidlest possible quantity of water at from 60^ to 80° C. ; the solution is filtered,
and cooled tul it crystallises : by evaporating the mother-liquor at a heat not exceed-
ing 50° C. farther crystals are obtained. The mother-liquor from these crystals, as
wdl as that originally drained off^ still contains alloxan, which is best separated by
bcang predonsly converted into alloxantin. For this purpose, Schlieper proceeds as
follows: — The -mixed mother-liquors are nearly neutralised by carbonate of caldum or
sodium — if the neutralisation were complete, the alloxan would be converted into
alloxanic add — and | of the mixture are saturated with sulphuretted hydrogen,
whereby sulphur and aJloxantin are precipitated, some dialuric acid being also formed
by the further action of the gas. The remaining | is then added, the alloxan in which
reconverts the dialuric add formed into alloxantin. The alloxantin, which separates
out completely in 24 hours, is freed from sulphur by solution in boiling water and crys-
tallisation. In order to convert it into alloxan, one half of it is boi^ with twice its
volume of water, nitric add bein£ added drop by drop until the evolution of nitric
oxide is perceptible, and the whole is heated in a water-bath until effervescence has
ceased: small portions of the remaining half are then added successively, until a fresh
addition produces no effeirescence, then a little nitric add, and so on till the nitric
add is completely decomposed, a little alloxantin remdning in excess. The solution
is then filtered hot, and 3 or 4 drops of nitric add added to the filtrate, which deposits
crystals of alloxan on cooling. The total weight of alloxan thus obtained, should be
about equal to that of uric acid employed. It is not advisable to operate on more than
70 to 80 grm. nitric add at once.

Schlieper prefers chlorate of potassium to nitric acid as an oxididng agent. Into a
basin containing 124 grm. or 4 oz. of uric add, and 240 grm. or 8 oz. of moderately
strong hydroduoric acid, he adds in succesdve portions, with constant stirring, 31
grm. or 6 dr. pulverised chlorate. Heat is evolved, which must not be allowed to
rise above a ccotain limit ; and a solution is obtained, containing only alloxan and
iir«a (C*H<N*0» -f H»0 + 0 - C*H*NK)* + CH*NK)). If proper care be taken, no
gas is evolved. The solution is diluted with twice its volume of cold water, and de-
canted after three hours from any undissolved uric add, which is heated to 50° with
a littie strong hydrochloric acid, and oxidised by a fresh portion of chlorate. In order
to separato tne alloxan from the urea, it is converted into alloxantin and reconverted
into alloxan in the manner above described.

The alloxan prepared hj the above methods contains 1 or 4 atoms of water of crys-
ialUsation. Anhydrous dloxan is obtained by heating the monohydrated compoimd

X 4

136 ALLOXAN.

to 150^ — 160^ C. in a stream of dry hydrogen : the tetrahydrated compoimd mwrt be
first converted into the znonohydrate by very careful heating to 100^. (G-melin.)

Properties. — Anhydrons alloxan is of a pale reddish colour, which is probably due
to the action of heat. When aystallised, it contains 1 or 4 atoms of water of crys-
tallisation. The crystals obtained by evaporating a warm aqueous solution, contain
1 atom of water : they are oblique rhombic prisma, belonging to the monodinic system,
having the appearance of rhomboidal octanedra truncated at the extremities ; th^
are large, transparent, and colourless, of a glassy lustre, and do not effloresce in the
air. Liebig and Wohler regarded this compound as anhydrous. Those obtained by
cooling a warm saturated aqueous solution are transparent, pearly crystals, often an
inch long, belonfl;ing to the trimetric system : they effloresce rapidly in warm air,
and when heated to 100^ are converted in the monohydrated compound. According
to Gregory, there exists a third hydrate containing 2| atoms of water.

Alloxan is readily soluble in water or alcohol, forming colourless solutions, whence
it may be precipitated by nitric acid. Its aqueous solution has an astringent taste,
and colours the skin purple after a time, imparting a peculiar and disagreeable smell.
It reddens litmus, but does not decompose alkaline-earthy carbonates : neither does it
attack oxide of lead, even on boiling.

The following is the percentage composition of the three varieties :

C*. . . 48 . . 88-8

H». . . 2 . . 1-41

N*. . . 28 . . 19-72

0*. . . 63 . . 4607

C*H»N«0*. 142 10000

Calc Gm.

C*H«N«0* . . 142 . . 88-76 . . 8866

H»0 . . 18 . . 11-26 . . 11-35

C*BPN«0* + aq. 160 10000 10000

Gale. L.a. W. ^ Om.
C*H«N«0* + H«0 . 160 . 74-77 . 78-6 . 7472
8HH) . 64 . 26-23 . 26-6 . 26-28

C*H«N»0* + 4 aq. 2l4 100^00 lOOM} 10000

Decompoeiiiona, — I. By Heat, When heated, alloxan melts, and is decomposed,
forming, besides other products, cyanide of ammonium and urea. (Handwb. d. Chim.)

2. By EUctrolysU. — An aqueous solution of alloxan is decomposed by the voltaic
current, oxy^n being evolved at the positive pole, and crystals of alloxantin formed
at the negative pole.

3. By Nitric acid. — Hot dilate nitric acid converts alloxan into paiabanic acid and

carbonic anhydride :

eHW»0* + 0 - C«H«NK)« + C0«

Purabanic ac.

Further action of nitric acid converts the parabanio acid into nitrate of urea and car-
bonic anhvdride. Monohydrated alloxan is scarcely attacked by heating with strong
nitric acid. (Schlieper.)

4. By Hydrochloric and Sulphuric acids. — When heated with these acids, alloxan is
converted into alloxantin, which gradually separates, and the mother-liquor yields on
'evaporation acid oxalate of ammonium. The decomposition goes through several
stages : firsts alloxantin, oxalic and oxaluric adds are formed ; then the oxaluric add is
decomposed into oxalic add and urea ; and the urea is finally resolved into carbonic an-
hydride and ammonia, which last combines with the oxalic add. (Liebig and Wohler.)

6. An aqueous solution of alloxan is decomposed by boiling into carbonic anhy^bide,
parabanic add, and alloxantin, which separating on cooling :

3C*H*NH)* = C0« + C«H*N*0« + C^WO»

^ t ~' AllozoQtin.
Furabanle
acid.

6. By reducing agents^ alloxan is converted into alloxantin. This deoompoeition is
effected by protochloride of tin, sulphuretted hydrogen, or zinc and hydrochloric add
(nascent hydrogen) :

20<H«NK)« + H« = C^*N*0' + HH)

the further action of the two latter reagents converts the alloxantin into dialuric add:

O^WO' + H« + H«0 «- 2C*H*N^*

^ , '

Dialarlc add.

ALLOXANIC ACID. 137

Tbt ame daeompMxtion ifl efieeted when an aqneons solntion of allozan ia boiled -with
eseen of solphnrons acid. When, however, aqueons alloxan ia saturated with anl-
pbiroiis anhjdride, and the aolntion eyaporated at a gentle heat^ it yields on cooling
hige efflorceeent tables of a conjugated acid, which, by analysis of its potassinm-salt^
wpptan to contain the elements of 1 atom alloxan and 1 atom snlphnrons anhydride
(Gregory^ When a cold satorated solntion of aqneons alloxan is treated with sul-
vhnooB aetd in excess, ammonia added, and the whdLe boiled, thionnrate of ammonium
isibiiiied:

(yB?S*0* + NH« + SO»H» = C*H»N»SO« + HH)

Tbionurlc
acid.

7. BjfJML aiialis and alkaline eariks, alloxan is converted into alloxanic acid :

C*H*N»0* + H*0 = C*H*N«0»

Alloxanic
aekL

Aqneoos alloxan gives with baryta- or lime-water a eradual white precipitate of allox-
snate of barium or calcium : a similar action is produced by a mixture of chloride of
faariam, or nitrate of silver, with ammonia. If the alkali be in excess, the precipitated
aUoExuste contains mesoxalate, and the filtrate contains urea (Schlieper). By boil-
ing with aqueous alkaliis alloxan is decomposed into mesoxaJic add and urea :

C*H«N«0* + 2H«0 » C«H«0» + CH*N*0

Metoxallc Urea,

add.

8w BvAmmtmia. — A solution of alloxan in aqueous ammonia turns yellow when
goitly ounled, and on cooling forms a yellow transparent jelly of mycomelate of am-
nonimn: the liquid retains in solution alloxanate and mesoxalate of ammonium and
iii«a(Liebig):

C*WNH>* + 2NH« - C«H<N«0« + 2H«0

Myocmelic
add.

9. WiUhferrouB salts, aqueous alloxan gives a deep blue colour, but no precipitate
vakm an alkali be sidded.

10. When aqueous alloxan is heat«d with peroxide of lead, carbonic anhydride is
etotrad, carbonate of lead precipitated, and urea is contained in the solution :

C^HWO* + 4PbO + H«0 « CH*NK) + 2C0^Pb« + C0«

11. When aqueous alloxan is gradually added to a boiling solution of neutral acetate
of lead, mesGocalate of lead is precipitated, and urea remains in solution. When the
lead-ecdutioa is added to the aUoxan-solution, alloxantin and oxalic add are formed.

F. T. C.

AUbOaEAVZO ACSD. OH<N<0^ » alloxan + H*0.

iKs^.^Disooveied bvLiebig and Wo hler, in 1838 (Ann. Ch. Pharm. xxvi. 292),
farther examined by Schlieper. (Ann. Gh. Pharm. Iv. 263, Ivi. 1.)

Fomation and briparaHon, — ^oxanio add is formed when alloxan is brought
into oontaet with aqueous fixed alkalis (see Axloxan), alkaline carbonates, or add
eaxhonate of calcium (Stadeler). It is prepared by decomposing alloxanate of barium
by solphmic addL The salt is suspended in a little water, and a slight excess of dilute
sulphuric add added, with constant a^tation : 6 pts. salt require 1^ pt. strong sul-
phuric acid, duly diluted. After digestion for some time at a gentle neat, the excess
of solpfanrie add is removed by pure carbonate of lead, the excess of lead by sul-
phuretted hydrogen, and the excess of gas by heat : the solution is then filtered, and
er^nrated to a syrupy either over sulphuric add in vacuo, or at a temperature not
exceeding 4(P C.

^vperties, — Thus prepared, alloxanic add forms hard white needles, arranged in
ndiated groups, or in warty masses : if it has been heated above 40*^ C. it crystallises
vith difficulty, or not at all The crystals are permanent in the air : have a sour taste,
Int a sweetish aftertaste ; are readily soluble in water, less readily, viz. in 5 to 6 pts.
aloobd, still less in ether. The solution is add to litmus, readily decomposes car-
bonates and acetates, and dissolves zinc, cadmium, &c., with evolution of hydrogen.
Its composition is :

C* . . . 48 . . . 800

H* . . . 4 . . . 2-6

N« . . . 28 . . . 17-6

O* . . . 80 . . . gO-0

C«M<NH> 160 100=0 ^

188 ALLOXANIC ACID— ALLOXANTIN.

It is ft dibasio add, forming acid as well as nonnal salts : the formula of normal
alloxanates is 0*WWNH)*, of acid aUozanates, CH'MKK)*. It also appears to form
basic salts with some heavy metals. Alloxanates are mostly obtained by the action
of aqueous alloxanic acid on metallic carbonates. The alkaline alloxanates are soluble
in water: the normal salts of other metals are generally more or less insoluble, the
acid salts readily soluble. They part with their water of crystallisation at temperatoiea
Taxying firom 100^ C. to 160^ ; and require a stronger heat for their decomposition.

The alloxanates have been investigated principally by Schlieper (^loc. cit). The
only one which requires special mention is the normal bariufn^salt, which is employed
for the preparation of alloxanic acid. It is obtained by mixing 2 vols, of a cold satu-
rated smution of alloxan with 3 vols, of a cold saturated solution of chloride of barium,
heating the mixture to 60^ or 70°, and adding gradually potash-solution, with constant
agitation. Each addition of ^tash produces a white curdy precipitate, which soon
redissolves: at last the precipitate remains permanent, and the liquid suddenly
becomes filled with alloxanate of barium, which falls down as a heavy crystalline
powder, and may be freed from chloride of potassium by washing with cold water.
If too much potash has been added, a persistent curdy precipitate forms, consisting of
basic alloxanate and mesoxalate of barium ; it must be redissolved by the addition of
a litUe alloxan-solution. A less abundant^ but more certainly pure product is obtained
by adding baryta-water to aqueous alloxanic acid.

Deeamposiiions, 1. By Heat. — When heated, the acid melts with intumescence,
becomes carbonised, and evolves vapours of cyanic add. Alkaline alloxanates are
decomposed by heat into a mixture of carbonate and (^anide. An aqueous solution
of alloxanic add is decomposed by boiling, carbonic anhydride being abundantly
evolved, and two new bodies formed, one of which, Uucoturio €Kid, being insoluble in
water, separates as a white powder when the solution, after evaporation to a syrup, is
diluted with water; while tne other, difiuafif remains in solution, but may be preci-
pitated by alcohoL The latter is formed in far the larger quantity. The composition
of these bodies is not accurately established: Schlieper assigns to the former the for>
mula 0«H»N«0«, to the latter, C»H*N*0«* or C^*N«0». Schlieper states that a third
substance is also formed, soluble in water and alcohol, with uie formula C*H^NK)*.
The alcoholic solution of alloxanic add is not decomposed by boiling. Allrtrr^Ln^f.^ m^
decomposed by boiling with water into mesoxalate and urea :

C*HWO« + ffO « C»H»0» + CHWO

2. When heated with nitric add, alloxanic add is decomposed into parabanic acid
and carbonic anhydride :

OH^W + O = C«H«N«0« + C0« + HH).

3. AUoxanate of potassium gives a dark blue predpitate with ferrous-salts. (See
Alloxan.)

Alloxanic add is not decomposed by sulphuretted hydrogen, or by boiling with
bichromate of potassium or bichloride of platmum.

According to Omelin, the compound described by Vauquelin (M^m. du. Has. tiL
26Z) by the names aeide purpurique blano or ur^pie suraxigenit (axuric add) is to be
regarded as impure alloxanic add. — F. T. C.

( Uroxin.) C»H*N«0» + 3HH) [or C*S*N*0^\+ ^SO].

History, — Probably firat noticed by Front; first described by Liebiff and Wohler
in 1838 ; .farther examined by Fritzsche, who called it uroxin (J, pr. Chem. xiv. 237).

Formation and preparation. — Alloxantin is formed in vanous reactions. 1. By
the action of warm dilute nitric acid on uric acid.— 2. By the action of electrolysis, or
of reducing agents on alloxan^ or by heatine it with water or dilute sulphuric add
(see Aixoxan) : also by dissolving alloxan in dialuric acid. — 3. By heating dialuramide
(uramil) with dilute sulphuric or hydrochloric acid, or thionurate of ammonium with
a large quantity of dilute sulphuric acid. — 4. By the action of the air on dialuric acid.
— 6. In the decomposition of caffeine by chlorine. (Rochleder.)

The following are the most usual processes for the preparation of alloTantin.
1. Dry uric add is added gradually to warm, very dilute, nitric acid, as long as it is
dissolved, and the solution evaporated till it has an onion-red colour ; or dilute nitric
add is added to 1 pt. uric acid in 32 pts. water, till all is dissolved, and the solution
evaporated to two-thirds ; the crystals obtained in either case are purified by re-crys-
tallisation firom hot water. — 2. Sulphuretted hydrogen is passed through an aqueous
solution of alloxan, till a crystalline magma forms ; this is dissolved by heat, the pre-
cipitated sulphur filtered off hot, and the filtrate crystallised. — 3. A solution of alloxan
in dilute sulphuric acid is heated for a few minutes, when it becomes turbid, and de-
posits crystals of alloxantin on cooling. — i. Dialurato of ammonium is evaporated at

ALLOXANTIN.

139

t gentlfl heat with a luge exoees of dilate sulphuric add ; when dialiiric acid aystal-
Hms oat, which im oooTerted into allorantin by the action of the air, without changing
its ajstilline form. (Qregorj.)

i¥op<r<ft».— The alloKantin obtained bj the aboye methods, contains 3 atoms of
vater of ayBtalliBation, which it does not lose till heated to above 160*^0. Of the
properties of anhjdrous alloTantin nothing is known. The ayBtals aro small, trabs-
puent^ colonrleaB, or yellowish, oblique rhombic prisms, hard, but fery finable. In
tboM prepared by methods 1, % and 8, the ang^ of the obtose lateral edge is 105^ :
m the dunorphons crystals obtained from dialurate of ammonium, it is 121^. They
redden litmus, but do not exhibit add properties in other respects. They are yeiy
elightly soluble in cold water, more abundantly, but still slowly, in boiling water,
frina idiieh solution the aHoxantin separates almost completely on cooling. The fol-
lowing is iba percentage composition of anhydrous and hydratod aHoxantin.

0»

112

Cole.

S5-8

1-5

41-8

Cnntatt.

160

Caie.
29-81

811
17*89
48-67

L.aiid W.

30'62

816

17-66

48-67

FritsiclM.

8006

8-04

17*62

49-38

(ya^Hy 268 lOO^ CH*N«0'+8aq.822 10000 10000 10000

JkeompoMtions, — 1. 3if heat, alloxantin yields a peculiar aystalline product.

2. By oxiduing agents, alloxantin is coUTerted into alloxan. This change takes
fiiee bIovIt, when its aqueons solution is exposed to the air, much more rapidly when
It 10 bested with chlorine- water ; or when it is diffused in boiling water and a small
qvtntitjr of nitric acid added. Selenious add also conyerts the hot solution of allox-
intiB into alloxan, with separation of selenium.

5. By reducing agents, e. g» sulphuretted hydrogen, a hot solution of alloxantm is
eonreited into maluric add :

CraWO' + H«S + H»0 " 2C*H*N»0* + S.

Dialuric add,

4. 'When boiled with excess of hydrochloric add, it is partly decomposed, and de-
podli an cooling; a white powder of alliturie add, CH*!^* (Schlieper). At the
■ante time, aTloran and parabanic add are formed, together with an add which
Sdilieper esBs diUtarie aad, which he has not succeeded in isolating.

6. With batyta-^ufoter, allnxnnfin giyes a yioLet predpitate, which, on boiling, turns
white, and then disappears ; the solution contains alloxanate and dialurate of barium,

Cra*N*0» + SBaHO = C*BXBa*NK)» + C*H«BaN*0* + H«0.

Alloxanate Dlalarate Ba.

Ba.

6. By ammoma, alloxantin is oonyerted into purpurate of ammonium (murexide).

C»H*NH>' + 2NH» = C«H»N«0« + H*0

Murexide.

This diange takes place dther in the wet or the dry way. In the dry way it occurs
▼hen alloxantin is neated to 100^ G. in an atmosphere of dry ammonia (Gmelin) : or
▼hen it is exposed at the ordinary temperature to air containing ammonia. ^ In the
vet way, an aqneous solution of alloxantin is coloured purple-red by ammonia : the
eoloiir oisappeaas on farther heating, or when left for some time in the cold. When
nitric add u gradually added to Sie hot alloxantin-solution, so as to form alloxan,
the addition of ammonia produces a deeper purple colour as the quantity of nitric
acid, and oonaeqnently of RllATim, increases ; but the coloration ceases when the
allmantin is entirely conyinted into alloxan. When a solution of alloxantin in tho-
roog^ boiled water is mixed with ammonia, and boiled till the purple colour has
dia^fwared, crystals of dialuramide (uramil) are deposited: the yellow mother-liquor
beoomes purple by exposure to the air, deposits crystals of purpurate of ammonium,
and finally ooagulates into a jelly of mycomelate of ammonium :

0»H«N^O' + 4NH« - C*H»N«0« + C^HWO* + 2HH).

Uramil. Hjoomel.

ainm.

The ibrmation of murexide depends upon the oxidation by the air of some of the
nraaul whidi is dissolyed in the ammoma. When a solution of alloxantin in aqueous
ammonia is repeatedly eyaporated at a gentle heat in an open yessel, the residue being
eadi time dissolyed in iiniinnt^ifi^ pnre oxalurate of ammonium is finally obtained : if the
air be ezdnded, this substance does not form.
7. Aqueous solutions of alloxantin and sal-ammoniac, both freed from air by boilings

140 ALLOXANTIN— ALLYL.

form a pinple-iwd mixture, which soon beoomee paler, and deposits oolonrlMa or
reddish scales of nramil: the mother-liqiior oontaina aQo3can and hydrochloric add :

CB«NW + WHKa - C*H*NK)« + C*H«N*0* + HCL

Uramfl.

Acetate or oxalate of ammoniom acts like the chloride.

8. When aqueous *Tlmr>wfiii ig heated with oxide of silver, csibonic anhydride is
evolTod, silTer reduced, and oxalnrate of sQver finmed :

(m*NH)» + 4AgK) + H*0 - 2C»H»AgNK)* + 2C0« + 6Ag.

Oulante tilTcr.

From nitrate of silyer, *nnnr««»iii precipitates metallic silTer : the illtnte gi^es a
white preeu>itate witii bazyta-water. Aqueous alloxantin dissohes mereorie oxide
with erolntion of gas, probably forming merenrons alloxanate. By peroxide of lead
allnrriitin is oonverted like alloxan. — 9. Aqneons alloxantin is decomposed by long
keeping, eren oat of contact with air, and is conTerted into aUoxanic acid. (Gregory.)

Tetrametkyl-Alloxantin, 0"H»^K)« - C\CH»)«NW + H«0.— This composi-
tion is assigned by Gerhardt to a product of the action of chlorine on caffeine, disco-
Tered by Bochleder (Ann. Ch.Phann. IxxL 1), also aMioSiAmaUeacid{^, v.) — F.T.C.

(SeeMsTALS.)
■VAUJMTMi (See TBZFsnim.)

Aarfl, ProwienyL G*H*.— Berth elot and Be Lnea in 1864 (Ann.
Gh. Fhys. [31 xliii. 267), by acting on glycerin with iodine and phosphonis, obtained
the componnd 0^*1, which they regarded as todotrityUne, that is to say, tritylene, O^*,
baring 1 at. H replaced hj^ iodine, but iriiich is now rather regarded as the iodide
€il the radicle allyL Zinin, in 1866 (Ann. Ch. Fharm. xcv. 128) by acting on this
iodide with snlpbocyanide of potassiiiiii, obtained a volatile oil, the snlphocyanide of
ally], CH'.CyS, identical wiui Tolatile oil of mnstud, and afterwards (Ann. Ch.
Pharm. xcri. 861) prepared the benzoate, acetate, &c. of the same series. Hofmann
andCahonrs, in 1866 (Compt rend, xlu.217; more folly, FhiL Trans. 1867, 1;
Ann. Ch. Fharm. ciL 286 ; Chem. Soc. Qo. J. x. 316), diBoorered allylic alcohol and
prepared a great number of its derivatiYes. Lastly, Berthelot and Be Loca in the
same year isolated the radical allyl, and prepared the dibromide and diniodide. The
existeoce of this radicle in the oils of mustard and garlic was first demonstrated
by Wert h eim. (Ann. Ch. Pharm. IL 289 ; ly. 297.)

Allyl is the third term in the series of homologous radicles OH"-*, rinyl CH*
being the second; it is the only radide of the series that has yet been isolated.

Allyl, in the free state, CH'* «> CH'.CH*, is obtained by decomposing the iodide,
CH*1, with sodium at a gentle heat, and aftOTwards <i^«ta'1Hng the liquid product. It
is a yeiy yolatile liquid having a peculiar pungent, ethereal ojoor, somewhat like that
of horse-radish. Specific gravity 0*684 at 14. Boils at 69^ C. Vapour-density by ex-
periment 2'92 , by calculation from the formula CH^* (2 vol.) 2*89. Allyl is but
little attacked by strong sulphuric acid. Fuming nitric add changes it into a neutral
liquid nitro-compound, soluble in ether and decomposed by heat. Chlorine acts
stroiijgly upon it| hydrochloric add being evolved and a liquid compound formed
heavier than water. Bromine and iodine unite directly wiu it, forming the com-
pounds CH»Br« and CH»I*. (Berthelot and De Luca.)

AS&T&-A&OOHOXN Hydrate of AUyl, CH*0 >- ^^|o.— Prepared by the

action of ammonia on oxalate of allyl, oxamide being formed at the same time :

(coy(CH')«o« + 2NH» - 2(CH».H.o) + K«.(coy.m

Oxalate of allyl. AUjl^oohoL Oxamide.

Dr^ gaseous ammonia is passed into oxalate of allyl till the whole is converted into a
sohd mass of oxamide saturated with allyl-slcohoL The latter is then distilled off in
a bath of diloride of caldum, and rectified over anhydrous sulphate of copper. The
alcohol appears also to be produced by Hi'arini'Tig benzoate or acetate of allyl with
potash (Z in an. Aim. Ch. Pharm. xcri. 362). It is a colourless liquid, baring a
pun^nt but not unpleasant odour, and a spirituous burning taste. It mixes in all pro-
portions with water, common alcohol, and ether. It bums with a brighter fiame than
common alcohol Boilinc-point 103^ C* It gave by analysis, 62*08 per cent C and
10-43 H, the formula CH*0 requiring 62*07 C, 10*34 H, and 27*6 9 0.

• One lample ofthe alcohol Tery careftillr prepared, was foand to boll between 90° and 100° C. TWa,
bowerer, mar hare ariira from decompotitlon ; at all OTentt, the number 103O agrees witb the diflbr.
ences generallj obterred In analogous ethyl and allyl*coropoands. (Hofmann.)

ALLYL, BBOMIDES OF. 141

iUljrl-Aleoihol 18 stran^y attraeti'd by phosphoric anhydride, a ooloniless gas, pro-
bably C'H\ being given ofi^ vhich bums with a very bright flame. It is yiolently
axi&ed by a mixture of acid ehromate of potassium and sulphuric acid, "with forma-
tkm of allylic aldehyde (acrolein), CH^O, and acrylic acid, CH^O*. The same trans-
foimation is effected, though more slowly, by platinum black. Potassium (or sodium)
deeompoBes allyl-aloohol, with evolution of hydrogen and formation of a gelatinous
mass of aUylate of potaasium, C"H^KO. Strong sulphuric acid acts on it in the same
mamier aa on oommon alcohol, oonyertiiig it into allyl-sulphuric acid, C^^H.80^
With potash and disnlphide of carbon, it yields the potassiumnsalt of allyl-zanthic

AXSn^ MBMKOmWB OV. The rnonohromide, C*H*Br, which is isomeric^
orperiiapB identical with bromotritylene, is obtained by the action of bromide of phos-
phona on aHyl-alcohol (Hofmann and Cahours); or by distilling dibromide of
txHykoe, CH'Br' (or hydrobromate of bromotritylene, CH'Br.HBrT with alcoholic
potash (Cahours). Its specific gravity is 1*47, and boiling-point 62^ C. (Cahours.)

The hydrobromate of this compound, or dibromide of tritylene, is produced when
liomine is gradually passed into an excess of tritylene gas ; but when tritylene iiB
paeaod into excess of bromine, a number of compounds are formed which may be re-
gaidsd aa compounds of hydrobromic acid with bromide of allyl having its hydrogen
mofe or leas le^aoed by bromine. (See Tstttlenb.)

Dibromide of Ally l^^ CH'Br*. — Allvl unites directly with bromine, the com-
bination being attended with evolution of heat If the action be stopped just as the
liquid begins to show colour from excess of bromine, and to give off hycut>bromic acid,
and if the liquid be then treated with potash, dibromide of allyl is obtained as a
oystalline body, vei^ soluble in ether. It melts at 37^ C. and when once Aised,
aomeiimes remains liquid at drdinazy temperatures. It may be volatilised without
deeompoaition (Berthelot and De Luca). The allyl in mis compoimd takes the
place of 2 at. H.

Tribromide of Allyl, C^WBi*. — Obtained by gradually adding bromine to
iodide of aDyl in a vessel surrounded by a freezing mixture. The mixture is left to
itself till Ute next day ; freed from oystaUised iodine by washing first with alkaline and
affcerwBids with pure water ; then dned and distilled ; the liquid which passes over is
a^un washed and distilled, collecting apart that which goes over fnm 210° to 220 °C. ;
the pmple liquid then obtained is cooled to 0° C. whereupon it solidifies in a ciys-
talline maas ; the mother-liquor is drained off; and the product is fused and again
rectified. By this method, tribromide of allyl is obtained as a colourless neutral
liquid, of not unpleasant odour, specific gravity 2*436 at 23° C, boiling at 217°
or 218°, and solidifying below 10°. By uow solidification, it yields shining prisms,
which melt at 16°. (Wurtz, Ann. Ch. Fhys. [3] Ix. 84.)

Alcoholic potash converts it into an etheroal suhBtance boiling at 135° C. Heated to
100° in a sealed tube with alcoholic ammonia, it is converted into DihromaUylamine,
N.H.(C'H3r)* (31 Simpson, FhiL Mag. [4] xvi. 257). The decomposition appears
Id ooosist of two .stages ; in the first, the compound Cu^Br", is converted into CH^Bz*,
and in the aeoon^ this latter is converted into dibromallylamine :

C«H«Br" 4- NH« - C^<Br» + NH^r.

}C^<Br
C^«Br -H 2NH^r.
H

Diaeolyed in glacial acetic acid, and heated with acetate of silver to 120° — 125° C.
for a week, it yulds bromide of sUver and triacetin (p. 25.)

The ladide C^H* in this compound is triatomic^ roplacing 3 at hydrogen, as seen in
the reaction just mentioned ; in other words the compoimd is formed on uie type H'.H'.
Wmts has obtained two compounds (or perhaps only one) isomeric with it, by the ac-
tion of bromine on bromotritylene, C^*J^. and on the isomeric body bromide of allyl.
Theae oomponnda are perhaps formed on the type H^H', their rational formula being
CH^Br^i*. The^ both have a s|>ecific gravity of 2*392 at 23° C, and boil at about
195°; but they differ somewhat in odour and in their action on silver-salts, the
former being more energetic in both respects than the latter (Wurtz). The action
of bromide of bromallyl on ammonia is totally different from that of tribromide of
ally], giving rise, not to dibromallylamine, but to the compound C'H'Br'.CH^Br'.
(Simpson.)

142 ALLYL-COMPOUNDS.

Ckiorotritylene, CH^Cl, ii obtained like the bn>r
mide, by the action of chloride of phoephoruB on allvl-alcohol, or by treating chloride
of tritylene, C"H«.C1* (hydrochlorate of allyl-chlonde, C»H»CLHC1) with alcoholic
potash. The last mentioned oomponnd treated with excess of chlorine yields sabsti-
tution-prodncts similar to those obtained with the bromide. (See TbityIsnil)

., I or, C»H« = (?H*.H.— Tritylene op propylene, the third

term in the series of hydrocarbons O'Hh, is perhaps the hydride of allyl.

AJXWlat ZOBZBBfl OV« The monoiodide (iodotritylene) CH% is obtained
by f^iV-illing glycerin at a gentle heat with diniodide of phosphoros ;

2C«HW + 2PP = 2(?H»I + I«0« + 8HK) + 2L

A quantity of tritylene-gas is giren of^ due to a secondair action, and a mixtare of
oxygen-acids of phosphoras with iodine and nndecomposed glycerin remains in the
retort Tri-iodiae of phosphorus may also be used, but the action is less regular.
The distillate is purified bv rectification, the portion which passes orer at 100^ C.
being collected apart (Berthelot and De Luca). Iodide of allylis idso produced by
the action of iodme and phosphorus on allyl-alcohol. (Hofmann and Oahoura.)

When first prepared, it is colourless, and has an ethereal alliaceous odour; but fay
the action of air and light, it becomes coloured and then gives off irritating TsponixB
Specific graTitv 1*789 at 160^ C. Boiling-j^int 101<'. It is insoluble in water, bot
dissolves in alcohol and ether. By the action of zinc or mercuzy, and hydsocUozie
or dilute sulphuric acid, it is converted into tritylene (hydride of dlyl) :

C^»I + 4Hg + HCa « CH* + HgK31 + Hg^
and C«H»I + 2Zn + HCl = C«H« + ZnCl + ZS.

Iodide of allyl is decomposed by silver-salts, iodide of silver being formed, and tlie
acid radicle being transfened to the aJlyl.^

Diniodide of Allyl, C*H*P. — Obtained by dissolving 6 or 7 pts. of iodine in
1 pt of allyl at a gentle heat. The mixture, which is liquid at first, soudifies after a few
minutes ; and by triturating the mass with aqueous potash, then digesting in boiUng
ether, and evaporating the ethereal solution, ike diniodide of allyl is obtamed in the
crystalline form. It is decomposed by distillation, yielding iodine and a neatrai
liquid. It is scarcely attacked by aqueous potash ; but alcoholic potash decomposes
it, producing a liquid which smeDs like idlyl. It is not acted upon by mercury and
hydrochloric acid. (Berthelot and De Luca.)

Iodide of Mereurallyl, C*H*Hg'I, is obtained by agitating iodide of allyl wilJi
metallic mercury. On oystallising the resulting yellow mass from a boiling mixture
of alcohol and ether, nacreous scales are formed, which turn vellow when exposed to
lights especially if moist. Th^ dissolve but sparingly in cold alcohol, and are nearly
insoluble in boiling alcohoL Heated to 100^ G. they sublime in rhombic plates ; at
135^ they melt, and solidify in a oystaUine mass on cooling. When quiddy heated,
they decompose, yielding a yellow sublimate and a carbonaceous residue. The alco-
hohc solution treated with oxide of silver, yields a strongly alkaline liquid, which
when evaporated leaves a syrupy mass, probably consisting of hydrate of mercurallyl.
(Zinin.)

ASXWla, oacZBa OV> Allylic ether, (0"H*)"0, is produced by the action of iodide
of aUyl on aJlylate of potassium :

(?H»KO + C»H»I - KI + (C«H*)»0 ;

also by the action of oxide of silver or oxide of mercuxy on iodide of aUyl :

2C«H»I + Ag«0 « 2AgI + (C»H»)«0.

A body having the same composition was obtained byWertheim (Ann. Ch. Phann.
IL 309 ; Iv. 297), by acting on oil of garlic, (O'H')'S, with nitrate of silver, and dis-
tilling the aystallme product thereby produced; also by heating oil of mustard
(sulphocyanide of allyl), with fixed alkalis, e, g, with soda-hme.

Oxide of allyl is a colourless liquid, lighter than water, and insoluble in water.
It boils at 82<^ C. (Hofmann and Cahours) ; between 85® and 87® 0. (Berthe-
lot and De Luca). It forms with sulphuric acid a conjugated acid yielding a
soluble barium-salt. Nitric acid conyerts it into a nitro-compound heavier than
water. With iodide of phosphorus, it yields iodide of allyl. Heated with butyric
acid it is decomposed, with formation of butyrate of allvL (B. and L.)

Ethyl-allyl-ether, C»HW0=C«H».C«H».0, is obtained by the action of iodide of
ethyl on allylate of potassium, or of iodide of allyl on ethylate of potassium. It is a
colourless aromatic, very volatile liquid, boiling at about 84® C. Similar compounds

ALLYL, SULPHIDE OF. 148

ue pmdneed hy tveaftiiig iodide of allyl with methylato, Amylate, and phenylate cyf
potuinim (Hofmann and Cahonrs). Amyl-^yl^tker boils at about 120® C.
(Berthollet and De Lnca.)

Otide ofAllyl and Glyceryl, or Triallylin, C'*H»0» « [^C| 0«.— Iodide

of aliyl digtillwi with potash and glyeerin yields this oompomid in the fonn of a liquid,
lxH]iiig at 232^ C, soluble in ether, and haying a disagreeable odonr. (Bert he lot
and De Luc a):

(C"H»r.H».0» + C«H»I - 8HI + (Cra»r.C»H».0«.

The fonnnla is tiiat of a triple molecule of water HK)*, in which 3 at H are replaced
by the triatomic radide glyceryl, and the other three by 3 at. of the monatomic
ndide aDyL

Dr«4MLXiT8 OV. Acetate, oxalate, snlphate, &c. (See the
■errenl acidsw)

MXMiWTtH amunanm OV. Oa of garlic, GV«S-(C*H*)<S Tor C<^i9].»Thi8
eofflpoQnd is produced by dJKtilling iodide of aUyl with protosnlphide of potassiiim :

2C^»I + K«S - 2KI + (C^»)«8,

and is oontained in the essential oils produced by distilling with watPT the leaves
and seeds of Tarious plants of the liliaceous and cruciferous orders. It forms the
principal constitnent of the oil obtained from the bulbs of garlic (Allium saiivum\
ftom which it was first obtained in the pure state by Wertheim in 1844 ; and it
exists in smaller quantity in oil of onions (Allium eepa). It occurs also, together with
10 per eent. of ott of mustard (sulphocyanide of aUyl), in the herb and seeds of
Tuaapi arvense, passing oyer when these matters are bruised with water and dis-
tilled. The leaves of AUiaria officiiudi» distilled with water yield oil of garlic ; the
seeds yield oil of mustard (Wertheim). The bruised seed distilled after maceration
in water, yields a mixture of 10 per cent oil of garlic, and 90 oil of mustard ; but the
seed produced in sunny places yields onl^ the latter. The herb and seeds of ThUupi
ammse yield a mixture of 90 per cent oil of ^lic, and 10 oil of mustard. The herb
and seeds of ^eri$ amara likewise yield a mixture of the two oils ; and yeiy small
quantities of the same mixture are obtained from the seeds of Capsella Bursa Pas*
toris^ R^^hanus Bi^kamstrum, and Sisymbrium Nasturtium. (PI ess, Ann. Ch.
Phaim. iTiii 36.)

To obtain the whole of the mixed oils, the several parts of the plants, especially
the seeds, must be macerated in water some time before distillation. For, in the
seeds of 7%laapi aroense, for example, the oils do not exist ready formed ; the seeds,
in &ct, emit no odour when bruised, and if before distillation with water, they are
heated to 100^ C. or treated with alcohol, no oil passes over ; and if tiie seed be ex-
hausted with alcohol, and the filtrate evaporated, there remains a czystalline residue
SiixBd with mucus, which, when triturated with water and with the seed of Sinapis
crwfMU, yidds, not oil of garlic, but oil of mustard. (Fless» Ann. Ch. Pluunn,
IriiLSe.)

Preparation, a. From Iodide of AUyl. — The iodide is cautiously dropped into a
eoDoentrated alcoholic solution of sulphide of potassium, the liquid then becoming
yery hot, and an abundant crystalline deposit of iodide of potaasium being forme£
As soon as the action ceases, the liquid is mixed with a slight excess of s^phide of
potaasinm; water is then added, and the oil which rises to tiie surface is rectified.

6. From Garlic. — ^The crude oil is obtained by distilling bruised garlic-bulbs with
water in a laige still. The oil passes over with the first portions of water, the pro-
duct amounting to 3 or 4 oz. from 100 pounds of the bulbs. The milky wi^er which
passes over at the same time, contains a large quantity of oil in solution, and serves
tberefine for cohobation. The crude oil is heavier than water, of dark brownish-
yellow colour, and has a most intense odour of garlic. It decomposes at 140^ C. ;
that is to say, somewhat below its boiUng-point, which is 150^, becoming suddenly
h^at^t assuming a darker colour, and giving off intolerably stinking vapours,
without yielding a trace of garlic oil; the residue is a black-brown glutinous mass.
(Wertheim.)

Preparation of the rectified oil. — ^The crude oil is distilled in a salt-bath (in the
water-bath the distillation is slower) as long as anything passes o^&t. One-third of
the crade oil remains behind as a thick dark-brown residue. The rectified oil is
lighter than water, and of a pale yellow colour, or after two distillations, colourless,
and smells like the crude oil, though less offensive. Does not evolve a trace of
of ammonia when treated with hydrate of potash. It covers potassium with a liver-
cokmred film of sulphide of potassium, depositing an organic substance, and giving
off a small quantity of a gas which burns with a pale blue fiame. With fuming nitrie

144 ALLYL, SULPHIDE OF.

acid, oil of vitriol, hydrocUoric acid gas, dilute acids and alkalis, ooiroaiYe aablimate,
nitrate of silyer, bichloride of platinum and nitrate of palladium, it behaves like pure
sulphide of allyL Even after being several times rectified and dried with chloride of
calcium, it exhibits a variable composition and a certain amount of oxygen, and
must therefore contain, besides sulphide of allyl, an oxygen compound, probably
oxide of allyl, the presence of which is indeed indicated by the reaction with potassium.
(Wertheim.)

Preparation qf^re Oil of Garlic or Sulphide o/AUyl. — ^The rectified oil is again
rectified several tunes ; dehydrated over chloride of calcium ; decanted ; a few pieces
of potassium introduced into it; and as soon as the evolution of gas thereby proauoed
has ceased, the oil is quickly distilled off from the residue. The rectified oil appears
to contain oxide as well as sulphide of ally], together with excess of sulphur, these
impurities either pre-existing in the crude oil, or being formed from sulphide of allyl
by the action of atmospheric oxygen, that portion of the sulphide which takes up the
oxygen, giving up its sulphur to the rest. If the potassium be not suffered to
complete its action before the liquid is distilled, it merely removes the excess of
sulphur, but does not decompose the oxide of aUyl, and a distillate is obtained, con-
taining from 65*17 to 64*76 per cent C, and 9*22 to 9*15 H. (Wertheim.)

Properties. — Colourless oil, of great refracting power, and lighter than water.
Boils at 140^ 0. May be distilled without decomposition. Smelfi like the crude oil
but less disagreeably. It dissolves sparingly in water, readily in alcohol and ether.

Calculattom.

Wertheim.

6C .

. 72 . . 6316 .

. 63-22

lOH .

. 10 . . 8-77 .

8-86

S .

. 32 . . 28*07 .

. 27-23

(C*H»)»S . 114 . . 10000 . . 99-31

Decompoeitions, — 1. Sulphide of allvl dissolves with violent action m/uminff nitric
acid ; the solution when diluted with water, deposits yellowish-white flakes, and ia
found to contain oxalic and sulphuric acids; according to HI as i wets (J pr. Chenu
IL 355) oil of garlic treated with nitric acid, yields formic and oxalic adds. — 2. With
cold oil of vitrioly it forms a purple solution, from which it is separated by water,
apparently without alteration. — 3. It absorbs hydrochloric acid aas in large quan-
tities ; the deep indigo-coloured mixture becomes gradually decolorised on exposoxv
to the air, and imm^ately if gently heated or diluted with water. — 4. From nitrate
of silver, it throws down a large quantity of sulphide of silver, whilst nitrate of silver
and allyl remains in solution (Wertheim). It is not altered by dilute acids or
alkalis, or by potassium.

CoTnbifMtions, — Sulphide of allyl does not precipitate the aqueous or alcoholic solu-
tions of acetate of nitrate of lead, or acetate of copper ; neither does it precipitate the
solution of arsenious or arsenic acid in aqueous sulphide of ammonium.

With solutions of ffold, mercury, palladium, platinum, and siltfer, it forms precipi-
tates, consisting of a double sulphide of aUyl and the metal, either alone or associated
with a double chloride.

Gold-precipitate,— Svl^]dde of allyl forms with aqueous trichloride of gold, a beauti-
frd yellow precipitate, which resembles the platinum-precipitate, but soon cakes together
in resinous masses, and becomes covered with films of gold.

Mercury-j^recipitate, — Alcoholic solutions of oil of garlic and corrosive sublimate
form a copious white precipitate, which when left to stand for some time, and espe-
cially if diluted with water, increases to a still sreater quantity. It is a mixture of
the compounds a and b, which may be separated by continued boiling with strong
alcohol, only the compound a being soluble therein. (Wertheim.)

a. The iJcoholic filtrate, when left to itself or evaporated with water, and after
washing and dxying, yields a white powder, agreeing in composition with tiie formula
(C»H*)«S.2Hg«S + 2(C»H»a.2Hga), or 2(C»H*)«S.Hg«S.6HgCl (anal. 10-91 C, 1-61 H,
63*67 n%, and 16-41 Ci :— <jalc 11-32 C, 1-57 H, 62*87 H§, and 16*70 Q). It blackens
superficially on exposure to the son ; when heated, it gives off vapours smelling like
onioiis,and yields a sublimate of calomel and mercury. When immersed in moderatelj
strong potash-ley, it acquires a light vellow colour from separation of oxide of mercozy ;
if this oxide be then removed by dilute nitric acid, there remains a white substance,
probably — (C»H»)«S.2Hg«S. When distilled with sulphocyanide of potassium, it
yields oil of mustard, together with other products. It is insoluble in water, and dis-
solves but sparingly in alcohol and ether. (Wertheim.)

h. The portion of the mercury-precipitate insoluble in hot alcohol contains the same
constituents, and has the carbon and hydrogen likewise in the ratio of 6 : 5 at., bat is
much richer in mercury. (Wert h e i m.)

ALLYL. 14o

TaSadntmrpttcipitate, — ^When rectified oil of garlic is gradually added to a solution
of nitrate of palladium, kept in excess, a farown precipitate is formed, which appears
to contain 2C*H'^.3Pd*S. — Chloride of palladium forms with oil of garHc a yellow
|inapitat«^ probably consisting of the preceding compound mixed with ehlonde of
paUaoium.

Baitnym^preeipUate,— -Ol\. of garlic forms a yellow precipitate with dichloiide of
piatiniuB. This precipitate is obtained of a finer yellow colour by the use of alcoholic
lolntions; bat when strong alcohol is used, its formation is gradual, becoming instanta-
Bcons boverer on addition of water. If the water be added too quickly and in too great
quantity, the precipitate is yeUowish^brown, resinous, and difiicult to purify ; the addi-
tioo of water must therefore be stopped as soon as a strong turbidity appears ; in that
cue, if the oil of garlic is not in excess, a copious flocculent precipitate is sure to be ob-
tained, resembling chloro-^Iatinate of ammonium. The precipitate is washed on the filter,
first vith alcohol then with water, and dried at 100*^,0. — ^When heated considerably
ahore 100°, it changes colour, and leaves sulphide of platinum in so porous a condition
that it takes fire at a higher temperature, and continues to glow till it is reduced to pure
platiniun. Faming nitric add decomposes and dissolyes the precipitate completely,
jonniuig dichloride of platinum and platinic sulphate. When immersea in hydroeulphate
of ammoniom, it is gradually conyerted into the kermes-brown compound next to be
dMcribed. Aqueous potash and sulphuretted hydrogen haye no action upon it. The
precipitate is nearly insoluble in water, and dissolves but sparingly in alcohol and ether.
It gires by analysis 17*85 per cent 0, 2*87 H, 48'53 Pt, 1829 S, and 13*22 CI,
▼hnioe Wertheim deduces the somewhat improbable formula, 3(C^'*S.2PtS) +
2(CT[»CLPta«), which requires 17*77 C, 2*47 H. 48*88 Pt, 17*77 S, and 13*11 d.

Kemut-brown compound, (0'H*)*S.2PtS, — Formed; together with dissolved sal-
ammoniac, when the platinum-precipitate just described is left in contact and shaken
m) irith bydrosulphate of ammonium. The brown compound heated to 100° C. emits an
aUiaeeons odour, and gives ofif 4*88 per cent, of sulphide of allyl. The darker substance
containing excess of platinum which remains, continues unaltered till it is heated to
140^ C. Irat between 150° and 160°, gives off 5*17 per cent, more, therefore in all 9*55
per cent, of sulphide of allyl, leaving a still darker compound of (CH*)^ with 3PtS.
The kermes-browB compound is insoluble in water, alcohol, and ether. (Wertheim.)

8Swr-precipitate^ — ^When a solution of nitrate of silver in aqueous ammonia is
mixed with excess of sulphide of allyl, one portion of the compound resolves itself
into oxide of allyl, which rises to the surface as an oil, and nitrate of ammonium ; but
then is also formed at the b^inning a white or pale yellow precipitate, which perhs^
eoDsistfl of (CH*)^ + xAg^. For if it be immediately washed with alcohol, and
dried between paper, it is resolved by distillation into sulphide of allyl and a residue
of snlpfaide of silver. But if it remains half an hour immersed in the liquid, it
asnnnes a continually darker brown colour, and is finally converted into black sulphide
ofailTer. (Wertheim.)

AIATA and BTBSOCHEH't VtTLntXBM OV> AUyl-mereaptany C*H"S a
C*ii*HJS.— ^ftoduced by distilling iodide of allyl with sulphide of hydrogen and
potaasinm:

C"H»I + KHS = KI + C^H».H.S.

It 18 a volatile oily liquid, having an odour like that of oil of garlic, but more ethereal.
It boils at 90 °C. It is powerfidly attacked by nitric add, assuming a red colour, and
yielding an acid analogous to ethyl-solphurous acid. It acts with &;reat energy on
mercuric oxide, forming a compound CH'HgS, which dissolves in boikng alcohol, and
leparates fix>m the solution in pearly scales resembling mercaptide of mercury. (Hof-
mann and Cahours.)

A&&T&. BraVBOCTAVJLTB OF. C^^S «- CNS.C*H>. ~ VolatUe oU of
Mtuiard. (See Svlfuocyaxig Ethbrs.)

AI&T&-0VSVBOCAXSAMZC, or BV&PBOBZVAPXC ACZB. C^BTNS* »
^ 1 H * — ^^ ^^^ ^ °^^ known in the separate state, but its soluble

salta, viz. those containing the metals of the alkalis and alkaline earths, are obtained
hy treating oil of mustard with the hydrosulphates of those metals: e, g.

C*H»NS + KHS « C^«KNS«,

It may bo regarded either as composed according to the preceding formula, that is to
ny, as hvdioeulphate of ammonium, NH\H.S, having 1 at^ H in the ammonium-mole-
eole lepUced by allyl and two more by the diatomic radicle CS, or as a compound of
iolphocyaoide of aUyl with solphide of hydrogen. The mode of formation leads
dii^ly to the latter view. (See Sttlfhosxnafio Acid.)
VouL L

146 ALLYL.

A&&T-«V&»BOCASBOVZC9 or AUbTlb^KaVTKZC AOZB. Sulphide

of AUyl, Carhonyl, and Hydrogen, C«H«S*0 = S^j^^^^,.— Wlien aUyl-alcohol is

treated with potash and disulphide of carbon, a salt is formed, which crystallises in
yellow needles like xanthate of potassinm. (H o f m a n n and C a h o u r s.)

AXiIiTb-BirXiVBinUO ACZB. O'RK'R.^O^.—SidjphaU of AUyl and Hydrogtn.
(See SiiLFHtTBic Ethebs.)

(See Carbamide.)

. C*H'N « N.H».(C»H»), is obtained by the action of ammonia
on iodide of allyl, or by boiling cyanate of ally! with strong aqueous potash^

CNO.C»H» + 2KE0 « CO»K« + N.ff(C>H*).

If the alkaline distillate be condensed in hydrochloric acid, a saline mass is obtained,
which when distilled with potash, yields, among other producta, a basic oil having the
composition of allylamine. The platinum-sfdt, CH'N.HCLPtCl*, separated from
solution by slow eyaporation forms magnificent crystals.

DiALLTLAiONB, OH"N w N.H.(C*H*)', is formed, together with other products^ by
the action of iodide of allyl on allylamine.

DiBBOMALLTiAMiNB, C^H^Bi^N = N.H.(C«H*Br)*.— Produccd by the action of am-
monia on tribromide of allyl (p. 141).

2C«H»Br" + 6NH» = C«H*Bi«N + 4NH*Br.

1 ToL tribromide of allyl is mixed with about 6 yoL of a solution of ammonia in weak
alcohol, and heated to 100^ C. in sealed tubes for 10 or 12 hours ; the liquid is then
filtered from the separated bromide of ammonium, and the filtrate mixed with a large
quantity of water, whereupon it becomes turbid, and deposits dibromallylamine in the
rorm of a heavy oil, wliich may be purified by dissolving it in hydrochloric acid, ersr
porating to dryness at 100° C, redissolving in water, filtering to separate a small
quanti^ of oil, again evaporating, and treating the residue with ether, in which the
nydrochlorate is nearly insoluble. From the salt thus purified, the base is separated
by distillation with potash. It is alkaline to test-paper, and forms a cloud with
hydrochloric acid : it is however but a weak base, incapable of decomposing the salts
of copper or silver. It cannot be distilled without alteration. It is but sparingly
soluble in water, but dissolves readily in alcohol and in acids. It has a peculiar sweet
and aromatic taste. It does not show much tendency to form aystallisable salts.
The sulphate forms a gummy mass. — The hydrochlorate is a yellowish salt easily
soluble m water and alcohol, sparingly in ether. It tastes like the base itself. It
assumes a darker colotir at 100° C. ana sublimes partially at 160°. On adding nitrate
of silver to the aqueous solution, the whole of the chlorine is precipitated as chloride of
silver, but the bromine remains in solution. The chloroplatinate, C*H'Br*N.HCLPtCl',
is an orange-coloured precipitate nearly insoluble in absolute alcohol Alcoholic solu-
tions of dibromallylamine and chloride of mercury form, when mixed, a copious Tiiiite
precipitate. (Maxwell Simpson, Phil. Mag. [4] xvi. 257.)

Ethyldibromallylamine, C«H'^r*N «= N.C*H*.(C»H^r)*. — Obtained by enclosing
dibromallylamine with a large excess of iodide of ethyl in a sealed tube, and heating
the mixture to 100° C. for a considerable time. The excess of iodide of ethyl is
then distilled off, and the remaining hydriodate of eth^lbibromaUylamine is dissolved
in water and distilled with potash. It has a very bitter and pungent taste, smells
like nutmeg, is insoluble in water, soluble in acids, and alkaline to test-paper. It is
a stronger base than dibromallylamine, and precipitates oxide of copper from capric
salts. (Simpson.)

Tbiaixtlamine, C»H»*N « N.(C»H*)", is formed by the destructive distillation of
hydrate of tetrallylium.

TETBALLTLnjM, 0"H»N = N(C»H*)*.— The iodide of this base is the chief product
of the action of ammonia on iodide of allyl The action takes place without the aid
of heat^ a large quantity of the iodide dissolving after a few days* contact ; the solution
afterwards deposits splendid crystals of the iodide, and sometimes becomes a solid
mass. The separation of the crystals may be accelerated by adding a strong solution
of potash, in which the iodide is completely insoluble. The iodide is purified by ex-
posing it to the air till the potash is converted into carbonate, and then reczystaUising
from absolute alcohol Treated with oxide of silver, it yields the hydrated oxide of
tetrallylium, and the solution of this oxide mixed with hydrochloric acid and bi-
chloride of platinum, forms a yellow salt containing N(C'H*)*Cl,PtCl'.

IkiraUylaraonium, As(CH*)*.~-When iodide of allyl is digested with arsenide of

ALL YL — ALOEa " 1 47

potaasiimi, sereral liquid compounds are formed, having a reiy fetid odour, and at the
sime time a solid crystalline body separates, which is Uie iodide of tetraUyl-arsonium.
(Hofmann and Cahours.)

C*H*. — A diatomic radicle which bears to allyl the same relation
Oat ethylene CH*, bears to ethyl C«H*. It is not known in the free state, and only
tvD of its oompoonds haye been prepared, yiz. the chloride and the acetate.

Chloride of Allyl ene, C»H^C1«. -^CT-ofetwc^onV?.— Obtained by the action of per-
diloride of phosphorus on acrolein (p. 56). To prevent the action from becoming too
violent, the retort should be externally cooled, the perchloride of phosphorus covered
vita a layer of oxychloride, and the acrolein added by small portions at a time. The
propQitions are 1 pt acrolein to 3 ^ts. of the perchloride. The crude distillate is shaken
0^ \rith water to remove ozychlonde of phosphorus, and further purified by digestion
with chloride of calcium and rectification, the chloride of acrolein passing over at
about 90^ C. It is a colourless oil, having a sweetish ethereal taste, and an odour like
that of chloroform. Specific gravity 1 • 1 70 at 27 "5 C. Boiling-point (corrected) 84 "4° C. —
Another oily liquid, apparently isomeric with chloride of allylene, is likewise formed
by the action of p^ehloride of phosphorus on acrolein.

Chloride of allylene is slowly oxidised by nitric add. Heated with aqueous nitrat<*
of silver, it precipitates chloride of silver. Chlorine converts it into a crystalline com-
pound, probably sesquichloride of carbon. Sodium has no action upon it Heated
with ethylate of sodium, it appears to yield a compound corresponding to acetal
(p. 3). Seated in a sealed tube with alcoholic potash, it appears to yield the
same compound, together with chloride ofacryly CH'^Cl. Heated in a sealed tube with
anifflonia^ it yields sal-ammoniac and acrolein-ammonia (p. 56). (Hubner and
Oeuther, Ann. Ch. Pharm. cxiv. 36.)

Acetate of Allylene, C»H"0* « (c^lm* \ 0\ Acetate of Acrolein^-^Viodvuied,

1. By heatiiig in sealed tubes a mixture of 1 at. acrolein (CH^O), and 1 at. acetic
anhydride (C*K*0*.) — 2. By heating 1 at chloride of aUylene with 2 at acetate of
tSl\a in a sealed tube, first in the water-bath for several hours, then to 160^ 0. in
aa oil-bath, reetlfying the product, and collecting apart that which passes over between
l«Oand I6OO: C»H*Cl« + ((?H»0)«.Ag*.0« = (C«HK))».(?H\0« + 2Aga It is a
eoloorless liquid, having a strong fishy odour, and very shaip taste. Specific gravity
11)76 at 22^ C. ; boils at about 180°. It slowly reduces an ammoniacal solution of
nifrate of silver. Heated with caustic-potash, it yields acrolein and acetate of
potaasiiim. It may he regarded as a compound of 1 at acrolein with 1 at. acetic
anhydride, C«HK).C^H*0». (Hiibner and Geuther.)

Native anhydrous sulphate of zinc (See Suiphates.)

(See Gahnbt.)

OV. — ^Both sweet and bitter almonds yield by pressure a fixed
oil, having a light yellow colour, an agreeable taste, but no odour. Specific gravity 0*918
at 15°. It consists chiefiy of olein, with but little solid fats, and consequently requires
a vay low temperature ( — 25^ C.) to solidify it It easily turns rancid. It dissolves
in 25 pta. of cold alcohol, in 6 pts. of boiling alcohol, and mixes in all proportions with
ether.

Bitter almonds macerated with cold water and distilled, yield also a volatile oil, of
fragrant odour, which is the hydride of beneoyl (CH'O.H). This oil does not exist
ready formed in the almonds, but is produced by the action of an azotised body,
etMdein, on the amygdalin contained m the fruit Sweet almonds do not contain
emolsin, and therefore do not yield the volatile oiL (See Bsnzotl, Htdbtob of.)

I. (See Alostic Acid.)

The thickened juice of various species of aloe, a genus of plants belong-
ing to the liliaceous order. It is chiefiy extracted from the Al^ aoocotrina in Arabia ;
from Aloe epicata and A. lingviformie at the Cape of Good Hope ; and from A, vtdgaris
or Hnttata in Barbadoes and Jamaica. The best sorts of aloes aro prepared by ex*
fmii^ to the sun the juice which exudes spontaneously from incisions in the leaves ;
mferior kinds are obtained by pressing the leaves. Aloes occurs in commerce in large
red-brown masses, having a shming conchoidal fracturo ; in thin plates it is red and
translucent; it is easily reduced to a yellow powder. It has an odour like that of
■aifron, and a very persistent bitter taste. It dissolves completely in alcohol and in
boiling water. It possesses active purgative properties, due to a crystallisable principle

L 2

148 ALGETIC ACID — ALOUCIII.

aloin^ which is contained in it, and may be extracted in a st&te of pnritj from Bar-
badoee aloes.

C?*fl'^»0"? Pbfychromio Acid. Artificial Bitter of Aloes.-^
Produced by the action of nitric acid npon aloes, ditjsanunic acid being formed at
the same tune (Schunck, Ann. Oh. Pharm. tttjt. 24; Izv. 236; G. J. Muldei;
J. pr. Ghem. zlviii. 39). 1 ^art of aloes is gently heated with 8 pts. of moderately
strong nitric add till gas begins to escape ; the vessel is then removed from the fire,
and as soon as the disengagement of gas ceases, the solution is concentrated by era-
poration, tUl a yellow powder separates, the quantity of which may be increased by
addition of water. The aloetic acid is separated from the chrysammic acid in this
powder by treatment with boiling alcohol, which dissolves the aloetic acid ; and m
evaporating the solution, the add is obtained in the form of an orange-yellow powder
having a bitter taste. It is but slightly soluble in water, but dissolves more freely in
boiling water, forming a solution of a splendid purple colour, which is changed to
yellow by nitric acid, but restored by alkalies. It is dissolved b^ ammonia^ potash,
and soda, forming purple solutions. Strong nitric acid converts it into chrysammic
acid. It is monobasic. The ten'vm-salt, C'H'BaN'O*, is a brown-red nearly msolnble
powder, obtained by predpitating the aqueous acid with acetate of barium. The
potassium-Bslt separates by slow evaporation in crystals of a fine ruby colour. Ac-
cording to Schunck, the formula of aloetic acid is C^*H*NO^*; according to Mulder
C* W^O". According to the formula above given, it is isomeric with dinitrobenzoie
add.

The alcoholic mother-liquor obtained in the preparation above described contains
another acid called Aloeretic acid^ CH'ON* ? which, according to Mulder, is the firrt
product of the action of nitric add on aloes. It is separated by neutralising vitii
chalk, mixing the filtrate with acetate of lead, decomposing the lead-predpitate with
hydrosulphuric acid, and evaporating. It is a brown amorphous mass, which when
boiled with nitric add is converted first into aloetic, then into chrysammic add.
(Mulder.)

The name aloeretic add is also applied by Schunck to an add produced bv the action
of alkalis on chrysammic acid, and called by Mulder chrysatric acid (whidi see).

C^TffitQi^ or C"ir«0".--A crystalline bitter prindple obtained fiwn
aloes : also called Bitter of aloes. It is prepared by mixing Barbadoes aloes with sand,
to prevent agglomeration, treating it several times with cold water, and evaporation
the aqueous extract in vacuo to the consistence of a syrup. It then separates in small
crystals. The solution most not be heated to the boiling-pointi since aloin undeigoet
alteration at 100^ C.

According to Dr. Stenhouse (Phil. Mag. [3] xxxvii. 481), the Cape and Socotria
aloes contain large quantities of foreign matters which prevent the crystaUisation of
the alo'in ; he has succeeded in isolating the aloin, only by operating on the Barbadoes
aloes.

Pure alom separates from an alcoholic solution, in the form of small prismatie
needles, grouped in stars, of a pale yellow colour. Its taste is at first sweet, then
extremely bitter. It is much more purgative than aloes itself. In the cold, it is but
slightly soluble in water and alcohol, but dissolves better when hot ; the solutions
are ydlow and neutral to test-paper. Dried at 100°C. it contains C"H"0'.

The caustic and carbonated alkalis dissolve aloin with a bright yellow colour.

By digestion with concentrated nitric acid^ aloin is transformed into chrysammic
add. Chlorine passed into an aqueous solution of aloin, produces a bright yellow
precipitate, chloralotlf containing, according to Robiquet, C^^CIO*. Solution of
chloride of lime colours aloin bright yellow, this tint passing rapidly to brown.

Bromine added in excess to a cold aqueous solution of aloin produces a yellow pre-
dpitate oi bromaloiny C"n'*Br*0'? which dissolves in boiling alcohol, and separates
in shining yellow needles, grouped in stars, and much larger than the ciystals of aloin.
It is less soluble in cold water and alcohol than aloin : the solutions are neutral.

1 — C*IPO* ? An oily liquid obtained in very small quantitvifcy distil-
ling aloes with half its weight of quick lime. It ia colourless, has a shar|rpenetnting
odour, is insoluble in water, but mixes in all proportions with alcohol and ether.
Specific gravity 0'877. Boiling-point 130°C. By contact with the air, or by the action
of strong nitrie acid on chlorine water, it is converted into a brown-red liquid, hearier
than water, and having a very decided odour of castorenm. Treated with oxide of
copper or chromic acid, it yields carbonic add, water, and hydride of benzoyl (Ro-
biquet, J. Pharm. [3] x. 167 and 241.)

AliOVCBZi or A&VORI BWBTW is imported from Madagascar, where it is

ALPHENE — ALUMINIUM. 149

obtaioed, araording to Yabnont do Bomare, from a tree called TimpL According to
ochezs, torn Wintera aromatica. It is friable, whitish on the outside, black wit'Lin,
has a marbled a^^earance, and a strongly aromatic, peppety, bitter taste. According to
Bonastro (J. JPhann. x. 1), it contains 68'12 p. c of resin easily soluble in cold
akohol, 20*4^ of resin sparingly soluble in cold alcohol, 1-58 essential oil, together
vith small qoantities of free acid and ammonia-salt, besides earthy impurities. The
sfuin^j soluble re8in.appearB to be of peculiar nature.

Bi 8VI1PBIBH OV« (See Sxtlfhocyaiodb of Ammoniuic)

A mineral haying the same composition as haryioedlcite, GCBaCa.
[or JaO.CO* + CaO.CC^, but erystelHsing in obhque prisms, whereas baryto-calcite
foims right rhombic prisms : hence carbonate of bfloinm and caldom is dimorphous.
Alstomte is found on Alston Moor in Cumberland.

(See Tellubede of Lead.)

Syn. of AsPABAGiN.

ACZ]>. C*H*SO*. — This acid, isomeric with ethylsulphuric or
ealphoTiiuc add, is produced, according to Regnault (Ann. Ch. Fhys. [2] Ixy. 98),
▼bim alcohol is heated with excess of strong sulphuric acid till olefiant eas begins to
be eyolyed (between 160^ and 180^ C.) When equal parts of sulphuric acid and alcohol
are used, nothing but sulphoTinic acid is formed, ana even iu the residues of the ether-
preparation on the large scale, the latter is the only acid found.

To prepare the barium-salt of althionic acid, the residue obtained in the preparation
of ol^ant gas from 6 pts. sulphuric acid and 1 pt. alcohol, is saturated with milk of
lime ; the filtrate, after eTaporation, is treated with oxalic acid to precipitate the lime ;
the Hqnid again filtered and saturated with baiyta- water ; the excess of baryta preci-
pitated by carbonic add ; and the filtrate evaporated, first by heat, and finally in yacuo,
ajstallisation then taking place as soon as the liquid acquires a syrupy consistence.
The salt when purified by recrystalHsation, forms spherules composed of small needles
permanent in the air, and giving off 8*^9 p. c (1 at.) of water in vacuo. The formula
of the oystallised salt is CH^BaSO^ + H^O. It is more soluble in water than the
EaldioTinate of barium, and dissolves also in alcohol especially when hot

rrom the aqueous solution of the barium-salt, the firee acid (the hydroeen-salt) may
be obtained by precipitating the baryta with sulphuric acid, and from this the other
lalta may be prepared by direct combination. The caicium-Bslt evaporated at the
gentlest possible heat, solidifies completely in a mass, without crystallising. The
copper^salt forms pale green, very thin rhombohedrons, having an acute angle of 60^.
(Regnault)

Hagnus (Pogg. Ann. xlvii. 523) was not able to find althionic acid in the residues
of the preparation of olefiant gas, but only ethionic, isethionic, and sometimes also
BoIphoTinic acid.

AliOpMEMm Pear-shaped earthem vessels used by the older chemists for sub*
liming. The^ are open at each end and fit into. _.

one another m the manner shown in fy. 7. At ^^' * *

the quicksilver works at Almaden in Spain, vessels cz^^^^^^ISr:^^ l&lT^'^'^'^tjil
of this shape are used to condense the mercurial B^||j^p^i^llPl^a^«^l|gpi|l
TapoQEB issuing firom the retorts. For this pur-.

pose they az«laid in the form of a chain on a slightly inclined suHace called the
dudd-bath, (See Hebcubt.)

(See Suu'HATBS.)

Compoonds <^ alumina with the stronger bases.

A basic sulphate of aluminium, A1^0*.S0' + 9H0, found native
at New Haven in America. It is a white, opaqiie, earthy mass, of specific gravity
1*705, soluble in hydrochloric acid. Gives oa its acid at a red heat. (S tromey er.)

Bymbcl, Al; Atomic weighty 13*75. — This metal occurs in a
great variety of forms, viz. as oxide (alumina^ anhydrous, and hydrated, sometimes
alone, but more generally associated with tne oxides of other metals, iron zinc,
g^udnum, magnesium, &c ; — as sulphate and phosphate ; as silicate, which is the chief
constituent of all olays, and in combination with other silicates, forms a vast number
of minerals, especialfy the felspars ; also as mellitite, or honeystone, as fluoride of
ahnninium and sodium in cryolite ; and in very small quantities in plants.

Alumina was first shown to be a distinct earth by Marggrafir in 1754, having
besa pterioosly confounded with lime. Oerstedt, in 1826, showed how to prepare

L 3

150 ALUMINIUM.

the cMoride of alnminium by passing cUorine over a red-hot mixture of alumina
and charcoal; and Wohler, in 1828 (Pogg. Ann. zi. 136) succeeded in eliminating
the metal by igniting the chloride with potassium. It was thua obtained in the form
of a grey powder intermixed with tin-white globules ariaing from partial fusion. It
has lately been obtained in the compact form, and in much larger quantity, by
H. Sainte-ClaiTe Deyille and others.

Preparation, — ^The mode of preparation now adopted is the same in principle $a
that of Wohler, depending on the action of sodium at a red heat on the chloride or
fluoride of aluminium, or better, on the double chloride or double fluoride of alumi-
nium and sodium. Sodium is used to effect the reduction in preference to potassium,
partly because it acts more regularly and with less Tiolence, and partly because it is
more easily prepared, and, having a lower atomic weight than potassium, a smaller
quantity of it suffices for a given amount of chemical work.

The process flrst adopted by Deville consisted in passing the vapour of chlofride of
aluminium over sodium contained in a tube of iron or copper wiuch was kept at a
dull red heat. Metallic aluminium was thus obtained, mixed with chloride of alumi-
nium and sodium. The latter was. removed by waahing with water, and the metallic
globules which remained were made to unite by heating them till they began to melt,
and pressing them together with a pipe-stem. The mass thus obtained was then
remeUed and cast into bars. Another method which promised to yield good results, but
has not yet been perfected, was to reduce the chloride of aluminium by vapour of
sodium. The mixture of carbonic oxide and sodium-vapour produced by heating a
mixture of charcoal and carbonate of sodium (see Sodium) was conveyed into a huge
earthen crucible by means of an iron tube passing through a hole near the bottom and
reaching nearly to the other side ; and as the sodium and carbonic oxide burned and
thereby heited the crucible, portions of chloride of aluminium were thrown in from
time to time. The crucible when cold was broken, and the aluminium separated
from the saline mass in the manner above described.

The quantity of compact aluminium obtained by these methods was however con-
siderably below the theoretical amount, a large portion of the metal being reduced in
the fbnn of a fine powder which re-fused to unite into globtdes. This inconvenience
may be obviated and much better results obtained by the use of fluor spar or cryolite
as a flux. These fluorides assist the union of the particles, apparently by dissolving
small quantities of alumina — ^produced by moisture adhering to the chloride, — ^which
surround the partidee of metal at the moment of reduction, and, not being decom-
posed by the sodium, prevent them from uniting into globules. The reduction may
be performed in crucibles, or better, in a reverberatory ^imace.

a. 400 parts of chloride of aluminium and sodium, 200 pts. of chloride of sodium,
200 pts. of fluor spar or crvolite — the latter being preferable — all perfectly dry and
flnely pulverised, are placed together, with 76 or 80 pts. of sodium, in alternate layers,
in an earthen or iron cmcible, which is moderately heated till the action b^^ins,
and afterwards to redness, the melted mass being stiired with an iron rod and after-
wards poured out. If the process goes on well, 20 pts. of aluminium are thus
obtained in a compact mass, and about 6 pts. more in globules encrusted in a hard
mass.

The aluminium thus obtained is, however, somewhat contaminated with silicon,
derived from the earthy matter of the crucible, which is attacked by the sodium, by
the aluminium itself, and by the fluorides in the slag. This evil may be corrected to
a certain extent, but not completely, b^ lining the crucible with a paste composed of
calcined alumina, or aluminate of calcium. If iron crucibles are used, the aluminum
is found to contain iron.

b. The reduction is performed with greater facility, and on a much larger scale,
by heating the mixture on the hearth of a reverberatory furnace.

The proportions used are :

Chloride of aluminium and sodium . . .10 parts.

Fluor spar or cryolite , . . .6

Sodium . . . . . .2

»f

The double chloride and the cryolite or fluor spar are mixed in the state of powder
with sodium in small ingots, and the whole is tlirown on the hearth of the furnace pre-
viously raised to the required temperature. The dampers are then closed to prevent
access of air. A vind action soon takes place, accompanied by evolution of heat,
sufficient to raise the walls of the furnace and the mixture itself to bright redness ;
and the mixture is almost completely liquefied. When the reduction is complete, the
fused mass is run out through an aperture at the back, the slag escaping first, and
then the aluminium fiowing out in a single jet, and collecting in one mass below the
liquid slag. With a furnace having a hearth about 16 square feet in surface, about

ALUMINIUAL 151

16 lbs. of alnniimum may be obtained at one operation. The slag consists of two
hjen, the appcr containing a larse quantity of common salt, while the lower, which is
pasty vad leas fusible, consists chiefly of fluoride of alnminium. On pnlyerising this
tatter and passing it through a sieve, an additional quantity of aluminium is obtained
in fdoboks. The fluoride of aluminium may be used for the preparation of alumina.

This process (which has been patented by JOLBousseau, Frires and M. Paul Morin,
both in France and in this country, 1856, No. 1810) is peculiarly adyantageous in
this TCBpeety that the reduced metal is yeiy little exposed to contamination with silicon.
The iB^oduction of this impurity generally arises from the action of the sodium or of the
dtg on the earthy matters of the Ycssels in which the reduction takes place. Now,
when cnicibles are used and the heat is applied from, below, the part of the mixture
in contact with the crucibles is necessarily the hottest, and consequently the action
exoted on the crndble is considerable ; but when the mixture is fused on the hearth
of a rererberatoiy furnace, with the flame playing on its surface, the coolest part is in
contact with the hearth, which is therefore less acted upon. Moreoyer with the pro-
portions above given, the whole of the fluorine is separated as fluoride of aluminium,
a compound which exerts but little action on silieious substances.

Pi^aratioK from Cryolite. — ^The pulverised mineral is mixed with half its weight
of common salt^ and the mixture is arranged in alternate layers with sodium (2 pts.
of eodium to 6 pts. of cryolite), in an earuien or iron crucible, a layer of pure cryolite
being placed at top, ana the whole covered with common salt. The mass is rapidly
heated till it melts completely, and then left to cool after being stirred with an iron
rod. The ahmainium is generally found in large globules. Such was the method
originally practised by Professor H. Kose in Berlin, and by Dr. Percy and Mr. Allen
Dick in this country. It is now carried on, on the manufacturing scale, at Am&eville,
Bear Bouen, by C. and A. Tissier.

A peculiar apparatus for effecting the reduction of aluminium, either &om the
double chloride or from cryolite, the object of which is to prevent loss of sodium by
ignition, has been invented and patented by F. W. Gerhard (1858, No. 2247). It
comists of a reverberatory furnace having two hearths, or two crucibles or reverbe-
ratoiy furnaces placed one above the other, and communicating by an iron pipe. In
the lower is plaoed the mixture of sodium with the aluminium-compound, and in the
upper a stratum, of chloride of sodium, or of a mixture of sodium and cryolite, or of
the slag obtained in a former operation. This layer when melted, is made to run into
the lower furnace in quantity sufficient to cover completely the mixture contained
therein, so as to protect it from the air.

The chief inducement for using cxyolite as a source of aluminium, is that it is
a natural product obtained with tolerable facility, and enables the manufacturer to
dispense with the troublesome and costly preparation of the chloride of aluminium
and sodium. But the aluminium thus obtained is less pure than that prepared from
the double chloride by the method previously described. If earthen crucibles are
used, the aluminium is contaminated with silicon, because the fluoride of sodium pro-
duced by the decomposition acts strongly on the silieious matter of the crucible ; and
if crucibles of iron are used, the aluminium takes up a portion of that metal. For
these reasons, Deville is of opinion, that the best use of cryolite is as a flux in the
preparation of aluminium from the double chloride. In that case, as already observed,
the sUg consists, not of fluoride of sodium, but of fluoride of aluminium, which acts
hot slightly on tiie containing vessel.

Seduction of tUumnium by means of hydrogen or carbon, — Several attempts have
been made, but with doubtful success, to separate aluminium from its compounds by
means of the ordinaiy reducing agents.

F. W. Gerhard decomposes fluoride of aluminium, or the double fluoride of alumi-
niom and potassium or sodium, by subjecting it to the action of hydrogen gas at a
red heat. The aluminium-compound is placed in a number of shallow dishes of glazed
earthenware, each of which is surrounded by a number of other dishes containing iron
filings. These dishes are placed in an oven previously heated to redness ; hydrogen
gas is then admitted, and the heat increased. Aluminium is then separated, and
hydrofluoric acid evolved, which is immediately taken up by the iron fllings, and
thereby prevented from acting on the aluminium. To prevent the pressure of gas
from becoming too great, an exit-tube is provided, which can be opened or closed at
|deasnre by means of a stopcock. This process, which was patented in 1856 (No. 2980),
is ingenious and was said to yield good results ; tlie inventor has however since returned
U> the use of the more costly reducing agent, sodium (see above), which would seem
to im^ that the hydrogen method has not quite fulfilled his expectations.

Sir Frauds C. Knowles has patented a process (1857, No. 1742) for reducing alu*
minium from its chloride by means of cyanide of potassium or cyanide of sodium, the

152 ALUMINIUM.

chloride, either in the fused state or in the form of yaponz being brought in contact
either with the melted cyanide or its vapour. Puve alumina may be added to increase
the product

L. F. Corbelli, of Florence, states that aluminium may be obtained by mixing the
impure sulphate (prepared by heating clay with strong sulphuric acid), with 2 pta of
ferrocyanide of potassium, and IJ pt. common salt, and heating the mixture to whiteness.
The metal thus obtained must howeyer be very impure, perhaps consisting chiefly of
iron. The process was patented in this country in 1858 (No. 142).

M. Cumenge, of Paris, obtains aluminium from the sulphide (Al^S*) either by heat-
ing that compound in an atmosphere of hydrogen, or by heating it with alumina or
sidphate of alimiinium, in such proportion that the oxygen contained in that com-
pound shall be just sufficient to convert the whole of the sulphur into sulphurous
anhydride :

A1*S« + 2A1*0« - 3S0« + 12A1
or APS* + A1*(S0*)» = 6S0* + 8A1;

or, Isfitly, by decomposing the sulphide with an ordinary metal, such as iron, copper
or zinc. This process is also patented (1868, No. 461).

Preparation of Aluminium by Electrolysis. — The electrolytic reduction of alumi-
. nium may be performed either in the diy or in the wet way. The reduction from
fused chloride of aluminium and sodium was first effected in this manner by Sun sen
in 1854 (Pogg. Ann. xciL 648^. The salt is introduced in a fused state into a red-
hot porcelain crucible, divided into two parts by a porous earthenware diaphragm, and
the extremities of the carbon poles of a Bunsen's batteiy of ten elements are introduced
into the two halves of the fused mass. The metal is then reduced at the negative
pole. The heat must be raised considerably above the melting-point of the cbuble
chloride, otherwise the aluminium separates in the pulveruleut form. It is best to add
fresh quantities of chloride of sodium during the reaction, and to raise the tempera-
ture ultimately to the melting point of silver. The aluminium is then obtained in
globules of considerable dize, which may be melted into one by throwing them into
chloride of sodium melted at a white heat Deville adopts a similar method, using^
however, platinum instead of charcoal for the negative pole.

The same method may be used for coating metals witii aluminium. Thus, if a bar
of copper be used as the negative pole, and a bar of aluminium as the positive pole,
tha latter dissolves as the action goes on, and is deposited upon the copper.

Aluminium may also be reduced by the action of the current from the solution of its
salts. Mr. Qtore has in this way obtained a deposit of aluminium on copper, and
Messrs. Evans and Tilley have patented a process (1855, No. 2756), for coating metals
with aluminium and its alloys, by electrolysing a solution of alumina mixed with
cTjranide of potassium, the negative pole being formed of the metal to be coated, and
the positive pole of platinum or aluminium, or of some other metal, such as copper,
tin or silver, which is to be deposited together with the aluminium. The bath may
also in some instances be composed of a mixed solution of aluminium and the other
metal to be deposited. — ^M. Corbelli, of Florence, obtains a deposit of aluminium by
electrolysing a mixture of rock-alum or sulphate of aluminium with chloride of calcium
or chloride of sodium, the positive pole being formed of iron wire coated with an
insulating material and dipping into mercury placed at the bottom of the solution, and
the n^ative pole of zinc immersed in the solution. Aluminium is then deposited
on the zinc, and the chlorine eliminated at the positive pole unites with the mercuiy,
forminff calomeL This process is also patented (1858, No. 607).

Of eSi the processes above described, the only one that has been successfidly applied
to the production of aluminium on the large scale, is the decomposition of the double
chloride or of cryolite by sodium. The electrolytic method is too expensive, excepting
for producing a thiu coating of aluminium on other metals ; and the attempts which
have been made to obtain ^uminium by means of the ordinary reducing agents, such
as hydrogen and charcoal, do not appear to have led to very satisfactory results. At
present, therefore, the progress of the aluminium manufacturo depends essentially on
the economical production of sodium; and indeed the manufacture of aluminium has
already given a great stimulus to that of sodium, and has led to considerable improve-
ments in that process, and consequent reduction of cost (See SoDnmc.) *

PKr(^a^n,— Aluminium may be purified from copper and iron by fusion with iiiti«
in an iron crucible, the foreign metals being thereby oxidised, while the nitre lemains

* When Deville commenced hli experiments in 1894, great hopes were entertained that Aliuninittn
might be produced at a price sufficiently low to admit of a variety of useful ai>pIications. Hitherto thcae
expectations have been but Imperfectly fulfilled, the metal being still too costly to be applied to other
than ornamental purposes. Still, however, great progress has been made, the price, which in 1856 was
U per OS., being now reduced to 5«.i and further reduction will doubtless be nude as the details of the
manufacture are Improted.

ALUMINIUM. 153

intact Before introdiKuig the almnixiiiim, the inner svaface of the crucible should be
veQ cuddised by the action of the nitre. Alnmininm containing zinc, may be freed
from that metal bj melting the alloy in contact with the air. No method has yet
been diaeoTered of porifying alumininm from siliam.

AluminTTim is yery apt to retain portions of the slag in the midst of which it has
been fcmned, causing the surface, when worked and polished, to exhibit a number of
points of inferior lustre, which gradually became more and more conspicuous. The
belt mode of purification is to melt the metal in an open black lead crucible for a con-
sidaahle time, then remore it from the fire and stir it with an iron skimmer oxidised
00 the 8Qi£ice, By this means, the whitish slaggy matter is remoyed, together with a
smaJl portion of the aluminium, which may be set aside to be remelted. The metal is
then cast into bars, and the whole operation repeated three or four times.

[For further information respecting the preparation of aluminium, see De Alumu
m'mi, par H. Sainte-Glaire DeyiUe, 8to. Pans, 1859; U Aluminium et lea Metaux
MealhUf par C. et A. Tissier, 12ma Paris et Bouen, 1858 ; Chemical Technologyy by
Biehsrdaon and Watts, yoL iy. pu 1 ; Urt^s Dictionary of Arts, Manufactures and
Mine*, yoL L p. 120.]

J^tjperties, — Aluminium is a white metal, with a faint tinge of blue. It takes a fine
poliah, and its snrfaoe may be frosted, like that of silyer, by plunging it for an instant
uto a -nxj weak solution of caustic soda, washing with a large quantity of water, and
then digesting it in strong nitric acid. When pure, it is quite destitute of taste and
odour. It is yery malleable and ductile ; may be beaten and rolled as easily as gold
lad silTer, and <u«wn out into extremely thin wire. In this last operation, however,
it becomes yery brittle, and requires to be tempered by cautiously heating it oyer a
lamp. In elasticity and tenacity, it ia about equal to silyer. After fusion it is as soft
as pore silyer ; bnt after hammering in the cold, it acquires the hardness of soft iron
It u hi^y Booorous, a bar of the metal suspended by a thread and struck with a
hard body, emitting a beautifully dear, ringing sound. It is yeiy light, being not much
more than 2| times as heavy as water, and about 4 times lighter than silver. Its
density after nxsion is 2*56, and after being hammered in the cold, 2 *67. Its melting-
point IS intermediate between the melting-points of zinc and silver, but nearer to the
fanner. It may he cast with the greatest ease in metallic moulds, and stiU better in
moulds of sand. It may be fused without any flux ; indeed, the addition of a flux
is rather detrimental than otherwise, the metal attacking borax and glass with
Polity. Aluminium, heated in a closed vessel, does not exhibit the slightest tendency
to volatilise.

The electric conducting power of aluminium is eight times as great as that of iron,
and about equal to that of silver; it conducts heat even better than silver. Its spedflc
heat is very great, and hence, though Its melting-point is comparatively lo^ir, it takes
a long time to liquefy. The melting together of small pieces of the metal may be
&eflitated by shalong the crucible and pressing them together with an iron rod oxi-
diied on the sur&ce. When slowly cooled from frision, it exhibits a crystalline
stncture ; the crystallisation is, however, most distinct when the metal is impure.
Aluminium precipitated from its solutions by electrolysis at low temperatures, crys-
tallises in octahedrons, which appear to be regular. It is slightly magnetic.

Aluminium does not oxidise in the air, even at a strong red heat ; neither does it,
in the compact state at least, decompose water, excepting at a white heat, and even
then butalowly (Deville). It is not attacked by sulphuretted hydrogen^ or even by
wlphide of ammonium^ and consequently preserres its lustre in the atmosphere of
luge towns^ where silyer is very soon tarnished and blackened. It may also be heated
to redness in vapour of sulphur without showing any disposition to combine ; at very
high temperatures, however, combination takes place.

Almninium is not attacked by nitric acidy either dilute or concentrated, at ordinary
temperatures, and very slowly even at the boiling heat ; neither is it acted upon by
sulj^ric acid diluted to the degree at which that acid dissolves zinc ; but hydro-
chloric acid, either dilute or concentrated, dissolves it readily, even at low temperatures,
with evolution of hydrogen. The vegetabie acids^ such as acetic and tartaric acid,
exert no perceptible action on aluminium ; a mixture of acetic acid and common salt
exerts a somewhat greater action, because it contains free hydrochloric acid ; but even
in this case the action is very slow, and not nearly so great as would exerted upon tin
under similar drcnmstances. Aluminium would therefore be well adapted for culinary
vessela, especially as the small quantity of alumina which might be formed from it by
the action of certain acid mixtures would not exert any ^eterious action on the
animal economy.

The hydrates of potassium and sodium in the state of fusion do not act upon alu-
minium, but their aqueous solutions dissolve it readily, forming aluminate of potassium
or aodium, and giving off hydrogen. Ammonia acts but slightly on it.

154 ALUMINIUM.

A solution of common salt pp chloride of potassium ia also witbont action on alumi-
nium, but the solutions of many otber cblorides dissolve it, and more readily, as the
metals which they contain are higher in the scale ; even a solution of chloride of
aluminium dissolves the metal, forming a basic chloride. Solutions of sulphates and
nitrates^ on the contrary, do not act upon it. Hence in precipitating other metals upon
duminium by electrolytic action, it is necessary to use acid solutions not containing
hydrochloric acid or any chloride. In an acid solution of sulphate of copper, the
aluminium quickly becomes coated with metallic copper.

AlTiTwi'Tiinm may be fiised with nitre at a moderate heat, without undergoing the
slightest alteration ; hence this process may be adopted for purifying aluminium from
admixtures of other metals. If however the heat be raised till the nitric acid is com-
pletely decomposed and begins to give off nitrogen, a new reaction takes place at-
tended with incandescence, and aluminate of potassium is formed.

Uses, — The lustre and whiteness of this metal, its unalterability in the air, and the
fiicility with which it takes a frosted surface, render it well adapted for jewellery, for
which purpose it is now much used. It also makes very bright reflectors. Its light-
ness renders it useful for mounting astronomical instruments, especially sextants. It
may also be used for making bjobJI weights, such as the diivisions of the gramme.
Very delicate balance-beams have also been constructed with it. For culinary vessels
it is adapted by its lightness and the little tendency which it has to become corroded
by any of the liquids likely to come in contact with it. It is necessary however to
observe, that this power of resisting t'he action of corroding agencies, and more espe-
cially those of the atmosphere of large towns, is exhibited only by the pure metal
Now, much of the aluminium of commerce is very impure, being contaminated with
iron OP silicon, or not having been properly freed from slag. Aluminium thus con-
taminated soon becomes tarnished, and much disappointment has been experienced
from this cause by many who have used it for ornamental purposes. According to
Deville, the impurities just mentioned are found to the greatest amount in the metal
obtained from cryoUte (p. 162).

General Characters and Reactions of Aluminium-compounds. — Aluminium forms
only one class of salts, and into these it is supposed to enter as a sesqui-equivalent
radicle, 2 atoms of aluminium taking the place of 3 atoms of hydrogen : Al' « H*. or
All = H. Thus, the chloride of aluminium is (Al*)"'Cl*; the oxide (alumina) is

(AIT'W*' the sulphate, (AI«)'«.3S0*, or ^^/^!]w[o«, &c. These formula are

based upon the isomorphism of the aluminium-compounds with other compounds of
corresponding character, which are known or supposed to contain sesqui-equivalent
radicles: thus, alumina, the only known oxide of aluminium, is isomorphous with
sesquioxide of iron and sesquioxide of chromium; and common potash-alum
(Al«)'"K'(SO«j« + 12H«0, is isomorphous with iron-alum (Fe«)'"K'.(SO«)« + 12HK),
and chrome-alum (Cr»)'"K'.(SO*)* + 12H*0. All these formulae may, however, be re-
duced to others containing mono-equivalent radicles, the values of which are two-thirds
of those of the corresponding sesqui-equivalent radicles. For instance, the aluminium-
compounds may be supposed to contain a radicle (alumtnicum\ al = }Al b).13-75«»
10*31. The formula of the chloride will then be alCl ; that of alumina, o/'O ; that of
the sulphate al^SO* ; that of alum, alK,SO\ It is sometimes convenient to write the
formulae in this manner.

Most compounds of aluminium are colourless. The oxide, hydrates, borates, phos-
phates, arseniates, and silicates, are insoluble in water; most other aluminium-com-
pounds are soluble. All of these, excepting the silicates, are soluble in, hydrochloric
and sulphuric acid, at least if they have not been strongly ignited.

The aqueous solutions have an add reaction, and an astringent disagreeable tasfe.
They are not precipitated by any fi?ee acid. With sulphide of ammonium and other
soluble sulphides, they give a white gelatinous precipitate of trihydrate of aluminium,
the formation of which is attended with evolution of hydrosulpnuric acid gas. The
precipitate is insoluble in excess of that reagent, but soluble in caustic potash or soda.
With solution of potash or soda^ the same gelatinous precipitate of the hydrate is pro-
duced, soluble in excess of the alkali, and reprecipitated by boiling with sal-ammoniac,
or by cautious neutralisation with hydrochloric acid. — ^With ammonia^ the same preci-
pitate, insoluble in excess. — With alkaline carbonates, the same, carbonic acid being
given off) and not entering into combination with the alumina. — y^iih ferrocyanids of
potassium^ a white gelatinous precipitate, after some time. — 'WiiAi phosphate ofsodium^
gelatinous precipitate, closely resembling the hydrate in appearance, and dissolving
with the same facility in hycGx>chloric acid and in potash. From these solutions it is
precipitated in the same manner as the hydrate, viz. from the hydrochloric acid solu-
tion by ammonia, and from the potash-solution by sal-ammoniac ; it is distinguished

ALUMINIUM (ALLOYS). 155

from tbe hydrate hffweret, b j its insolttbility in acetic acid, and bj exhibiting certain
reietions of i^oephoric adid {q. v.)

Most oomponnds of aluminium, when moistened with a small quantity of nitrate of
cMt^ and ignited before the blowpipe, exhibit a fine characteristie blue colour. This
duncter is best exhibited by placing a small quantity of alumina, precipitated as
aban, OD ehaieoal or platinum-foil, heating it to redness, then moistening with nitrate
of eobiit^ and igniting again.

Qftantitativ$ Estimation of Aluminium. — ^Aluminium is usually precipitated in the
farm, of hydrate by excess of ammonia or carbonate of ammonium, or better by sul-
j^de of ammonium, because an excess of ammonia or its carbonate dissolves a
email hit peroeptible quantity of the hydrate, which can then be reprecipitated only
bj boiliiig the liquid till every trace of ammonia is expelled. The precipitate when
ignited leaTCS anhydrous alumina, containing 63*26 per cent, of the metaL

Afamumum may also be yeiy oonyenienf ly separated from its solutions by boiling
▼ith ^kosviphite of sodium; alumina is then precipitated together with sulphur,
^vlnle siuphnrous acid is expelled, and a sodium-salt of the acid previously combined
with the alumina remains in solution : thus, if the aluminium exists in solution as
sulphate:

S»0»«A1* + 3SK)^a* « A1*0* + 8S + 3S0« + 3S0<Ka«.

The liquid should be dilute, and must be boiled till it no longer smells of sulphurous
add; the alumina then separates quickly in a compact mass, not at all gelatinous, and
T«7 easy to wash. The sulphur mixed with it is very easily expelled by ignition.
(G. Chancel, Compt. rend. xlvi. 987.)

This mode of precipitation by hyposulphite of sodium, serves also to separate
ahuniniam tram many metals, especially from iron, the latter metal being reduced to the
ftate of protoxide, and remaining in solution as a sodio-ferrous hyposulphite. To
eosnre complete separation, the solution must be nearly saturated, if necessary, with
an alkalme carbonate, diluted to a considerable extent, and mixed with the hypo-
nlpfaite while cold ; otherwise the alumina separates too quickly, before the iron is
completely reduced to protoxide, and then carries some of the iron down with it.
After the separation of the alumina, the iron is re-oxidised by nitric acid and preci-
pitated by ammonia. (ChanceL)

Almnioium may also be separated frx)m the alkalis and alkaline earths, by precipi-
tatbn with amnxonia or sulphide of ammonium. In thus separating it from tne
allralme earths, however, care must be taken to protect the solution from the air,
otherwiie carbonic acid will be absorbed by the excess of ammonia, and wiU preci-
pitate the alkaline earth together with the alumina. From barium, aluminium is
most easily separated l^ sulphuric acid.

Altoys of ^iTTw«-f«wfi- Aluminium forms alloys iidth most metals. With rnnc
and tin it unites readily, forming brittle alloys ; with cadmium it forms a malleable
aflov. With iron, aluminium unites in all proportions, forming alloys which are
hard, brittle, and crystallise in long needles, when the proportion of iron amounts
to 7 « 8 per cent. Aluminium containing iron dissolves m acids jnore readily than
the pore metal. (Deville,)

Aluminium ^oyed with even a small proportion of silver, loses all its malleability.
An alloy containing 6 per cent, of silver may, however, be worked like the pure
metal, and has been used for making knife-blades. An alloy containing 3 per cent,
of silver is used for casting ornamental articles. It has the colour and lustre of silver,
and is not tarnished by siuphuretted hydrogen. (D evi 11 e.)

The alloys of aluminium and copper are of especial importance. One in particular,
ccmtainisg 10 pts. of aluminium with 90 pts. of copper, called aluminium-brome,
pcasesaes very remarkable properties. It is a definite compound, containing Cu*Al.
It has the colour of gold, takes a high polish, is extremely hard, and possesses a
tenacity equal to that of the best steel ; it is also very malleable. Another alloy con-
taining only 2 or 3 per cent, of copper, is used for casting ornamental articles of large
(dimension, intended to be chased. Aluminium may be easily plated on copper. The
I^es of the two metals are prepared in the usual manner, and well rubbed with sand,
^en placed between two plates of iron, the whole being well bound together, heated
to low redness, and then strongly pressed. (Deville.)

Alloys of aluminium may be prepared by heating a mixture of alumina and the
oxide of another metal, such as copper, iron, or zinc, or a mixture of alumina with
ctrbon and the other metal in the free state, granulated copper, for instance, the
materials being all very finely divided, and mixed in atomic proportions ; or rather
with the carbon slightly in excess. This method, due to a foreign inventor, has been
P«ientedin this country in the name of E. L. Benzon (1858, No. 2753).

156 ALUMINICJM.

Amalgamation and Gilding of Aluminium, — ^According to Cailletet, alnminiam may
be amalgamated by the action of ammonium-amalgam or sodium-amalgam and water,
also when it is connected with the negative pole of the voltaic battery, and dipped
into the mercury moistened with acidulated water, or into nitrate of mercury. —
Ch. T iss i er (Compt. rend. xlix. 56), confirms this statement respecting the amalgamation
of aluminium in connection with the negative pole of the batteiy, and adcb, that if
the aluminium foil is not very thick, it becomes amalgamated throughout, and vciy
brittle. The same chemist finds that aluminium may be made to unite with mercuiy,
merely by the use of a solution of caustic potash or soda, without the intervention of
the batteiy. If the surface of the metal be well cleansed and moistened with the
alkaline solution, it is immediately melted by the mercuiy and forms a shining amal-
gam on the surface.

The amalgam of aluminium instantly loses its lustre when exposed to the air,
becoming heated and rapidly converted into aluminium and metallic mercury. It
decomposes water, with evolution of hydrogen, formation of alumina^ and deposition
of mercury. Nitric acid attacks it with violence. (Tissier.)

To aild aluminium, 8 grammes of gold are dissolved in aqua regia, the solution is
diluted with water and left to digest till the following day, with a slight excess of
lime ; after being well washed, it is treated at a gentle heat with a solution of 20 gnus,
of hyposulphate of sodium. The filtered liquid serves for the gilding of aluminium,
without the aid of heat or electricity, the aluminium being simply immersed in it, after
having been well cleaned by the successive use of potash, nitric add, and pure water.
(Tissier.)

It is somewhat difficult to solder aluminium, partly because no flux has yet been
found that will dean the surface without attacking either the aluminium or the solder,
partly because the surface of the aluminium is not easily melted by metals more fusiUe
than itself. An imperfect soldering may indeed be effected by means of zinc or tin,
but a better method, devised by M. Hulot, is to coat the aluminium with copperj by
the electrolytic method, and then solder in the ordinary way. (Devi lie.)

Arsenide of Alwmtnlwin* (See Ahsbnides.)

Borlde of Almnlnlmn. Boron unites with aluminium under the same drcmn-
stances as silicon (p. 160), and alters its properties in a similar manner.

Bromide of Almntnlnm, Al'Br', is obtained by the action of bromine on pulveru-
lent aluminitmi, the metal beins in excess. By sublimation, it is obtained in white,
shining laminae, which mdt at 90^, forming a mobile liquid which boils at about 265° C.
It is decomposed when heated in contact with the air. It dissolves in bisulphide of
cairbon, forming a solution which fumes strongly in the air. It dissolves in water,
and the solution evaporated in vacuo over oil of vitriol, leaves needle-shaped crystals
containing Al'Br' + 6HK>. With bromide of potassium, it forms the double salt
KBr.Al^r". It absorbs ammonia and hydrosulphurio acid, forming compounds which
are decomposed by heat (R. Weber, Pogg. Ann, dii. 254.)

CbloHde of Alnmliiliuiit Al'Cl*. — The finely divided metal heated to redness in
a current of diy chlorine gas, takes fire and is converted into the chloride, which
sublimes (Wohler). The compound is also produced by passing diy chlorine over
an ignited mixture of alumina and charcoal : and this is the method adopted for pre-
paring it. Hydrate of aluminium precipitated from a hot solution of alum by an
alkaline carbonate is made up into small pellets with oil and lampblack, and the mix-
ture is strongly ignited in a crucible : the oil is then decomposed and an intimate
mixture of alumina and charcoal remains. This is introduced into a porcdain tabe
or tubulated earthen retort placed in a fiimace, and connected at one end with an
apparatus for evolving chlorine, and at the other with a diy receiver. On raisins the
heat to bright redness, and passing chlorine through the apparatus, cMoride of
aluminium is formed and condenses in a solid mass in the receiver.

A similar process is adopted in preparing the compound on the large scale. Alu-
mina or clay is mixed with cool, pitch, tar, resin, or any organic substance that will
decompose by heat and leave a considerable quantity of charcoal, and the mixtmv,
after being well caldned, is heated to redness in a cylinder of earthenware or cast
iron, through which a current of dry chlorine is made to pass. The vapours of
chloride of aluminium pass into a condensing chamber lined with plates of glazed
earthenware, on which the chloride collects in the solid state. If day containing
a considerable proportion of iron is used in the preparation, it must first, after
ignition with carbonaceous matter — whereby the iron is reduced to the metallic
state — be treated with a dilute acid to dissolve out the iron, then washed and dried.

Chloride of aluminium is a transparent waxy substance having a crystalline stmc-
ture like talc. It is colourless when pure, but generally exhibits a yellow colour, dns

ALUMINIUM (CHLORIDE— OXIDE 15Y

periiaps to the presenoe of iron. It is ^ible in lai^e masses, and according to
liebig, boils at aoont 180^ C. A small quantify volatilises immediately when heated.
It iiimefl in the air, and smeHs of hydrochloric add. It is decomposed at a heat
beknr redness by potassium or sodium, aluminium being set free. When it is dis-
tilled with sulphuric anhydride, sulphurous anhydride and chlorine are giyen off and
ndphale of aluminum remains. (H. Bose.)

2Al«a« + 6S0* - Al\SO*y + 3S0« + 6CJL

Chloride of aluminium is yery deliquescent^ and dissolves readily in water. The
Bolutioo left to evaporate in a warm diy place, fields the hydrated chloride APCl'.
6H^ in six-aided prisms. The same solution is formed by dissolving alumina in
hydrochloric acid. The anhydrous chloride cannot be obtained by heating the
hvdrated chloride, because the latter is thereby resolved into alumina and hydro*
chloric acid.

Chloride of Aluminium and Sodiumy NaCLAl'Cl', is obtained by fusing together
the component chlorides in the proper proportions ; by passing the vapour of chloride
of aluminium over iused chloride of sodium ; or by adding the proper quantity of
chloride of sodium to the mixture of alumina or aluminiferous matter and carbon used
for the preparation of chloride of aluminium, and igniting the mass in an atmosphere
oi dry chlorine or hydrochloric acid, and condensing the vapour in the same manner as
that of the simple chloride. It is a cxystalline mass which melts at 200^ C, and
oyBtaDiseB on cooling. It is perfectly colourless when pure, much less deliquescent
than chloride of aluminium, and bein^ quite fixed at ordinary temperatures, may be
handled with fiuality. These qualities render it much more convenient than the
simple chloride for the preparation of aluminium. When ignited with sodium, it
yie&OB nearly the theoretical quantity (14 p. c.) of aluminium.

If Al'F', is produced by the action of gaseous fluoride of
silicon on aluminium. The product is at first mixed with reduced silicon, but this
may be easily removed by digestion with a mixture of hydrofiuoric and nitric acids.
Fluoride of aluminium then remains in a colourless mass of cubical crystals, which
have but little refracting power. It volatilises at a bright red heat, is insoluble in
water, and resists the action of all acids. (Deville, Compt. rend«xliii. 49.)

fluoride of Aluminium and Potassium, SKF.AI'F', is obtained as a gelatinous pre-
cipitate by Chopping a solution of fluoride of aluminium into a solution of fluoride of
potaasium, till the hitter remains in only' slight excess. A precipitate of similar cha-
racter, but consisting of 2KF.A1'F*, is obtained by stirring up a solution of fluoride of
ahimininni with a quantity of fluoride of potassium not quite sufficient for complete
saturation. Both precipitates dry up to white powders, and give off the whole of
their floorine as hydrofluoric acid when heated with sulphuric acid. (Berzelius.)

Fluoride of Aluminium and Sodium^ 8NaF.Al^. — ^Found native as Cryolite^ and
prepared artificially by pouring hydrofluoric acid in excess on a mixture of calcined
alumina and carbonate of sodium in the proportions indicated by the formula, then
diyii^ and iusing the mixture. Ciyolite belongs to the quadratic or dimetric sys-
tem. It is colourless and transparent^ softer than felspar, of speciflc ^vity 2*96,
melts below a red heat, and forms an opaque glass on cooling : so likewise does the
artificially prepared salt. It is found in large quantity at Evigtok in Greenland, but
has not hitherto been discovered in any other locality. It is used, as already
described, for the preparation of aluminium, and also in Germany for the manufacture
of soda for the use of soap-boilers.

of Jllufnlntnm, Al^*, is obtained by heating the metal with iodine or iodide
of silver in sealed tubes. After repeated sublimation over metallic aluminium, it
forms a snow-white crystalline mass, which melts at about 185° C, and boils at a tem-
perature above the boiling-point of mercury. It resembles the bromide in most of its
propertiea. With water it forms the hydrate A1^'.6HK), which may also be obtained
uj dissolving hydrated alumina in h^driodic acid. It forms double salts with the
a&aline iodides, and absorbs ammonia, forming a snow-white powder. It does not
appear to combine with hydrosulphuric acid, ^eber, Pogg. Ann, cvii. 264.)

OxlAe of ^i»»i»t«««w»- Alumina, Al^O', or APO^. — This, which is the onlv
known oxide of aluminium, is formed by the direct combination of the metal with.
oxygen. Aluminium in the massive state does not oxidise, even at a strong red heat ;
but in the state of powder it bums brightly when heated to redness in the air or in
oxygen gas, and is converted into alumina, 53 '3 pts. of the metal taking up 46*69
pts. of oxygen to form 100 pts. of oxygen. The atomic constitution of alumina
cannot be determined from this or any other direct experiment, because there is no
other oxide of aluminium with which to compare it ; but it is inferred to be a sesqui-

158 ALUMINIUM (OXIDE).

oxide, because it is isomoiphous with the sesqnioxides of iron and chromium, and is
capable of replacing those oxides in combination in any proportion.

AliiTninji. occiirs native, and very nearly pure, in the form of corundum^ varieties of
which, difitingoished chiefly bv their colour, are the $apphire^ 't'^i oriental topaz,
oriental ameihi/st, &c. The colourless variety is called hyaline corundum. The crys-
talline forms of these gems all belong to the rhombohedral or hexagonal system, Uie
primaiy form being a rather acute rhombohedron. Ahimina in the crystalline state
has a specific gravity of about 3*9, and is, next to the diamond, the hardest sub-
stance known. An opaque variety of corundum called emery ^ wltieh has a brown-
red colour, arising from oxide of iron, is much used in the state of powder for polish-
ing glass and precious stones.

Alumina is prepared artificially : 1. By precipitating a boUing solution of common
alum (sulphate of aluminium and potassiimi), free from iron, with carbonate of am-
monium, washing the precipitate with water, and igniting it to expel the combined
water. — 2. By igniting sulphate of aluminium or ammonia-alum. In the former case,
sulphuric anhydride is given off ; in the latter, that compound, together with sulphate
of ammonium, and alumina remains :

A1*.3S0* r, A1*0« + 3S0»
and 2(A1«.NH*.2S0») «= A1*0« + (NH«)«.SO* + 8S0«.

Alumina thus prepared is apt however to retain a small quantity of sulphuiie acid,
and if the original salt contained iron, the whole of that impurity remains in the
residue. — 3.* By digesting clays, felspathic rocks, or other minerals containing alumina
in a strong solution of caustic potash or soda, assisting the action, if necessary, by
boiling under pressure, or by heating the same minerals with kelp or soda-ash in a
reverberatory furnace, and lixiviating the fused product with water. A solution of
aluminate of potassium or sodixmi is thus obtained, a silico-aluminate of the alkali
generally remaining imdissolved — and the alumina may be precipitated from the solu-
tion as a hydrate by passing carbonic acid through the liquid ; by treating it with
acid carbonate of sodium, or with neutral or acid carbonate of ammonium ; by saturating
with an acid (using by preference the last vapours of hydrochloric acid evolved in the
manufacture of that compound) ; by treating it with chloride of ammonium, where-
upon, ammonia isitvolvea, chloride of potassium or sodium remains in solution, and
alumina is precipitated ; or by mixing the solution of the alkaline aluminate with
chloride of aluminium, the result being the precipitation of the alumina from both
compounds :

A1^>0» + A1«C1« « A1*0« + 3Ka
* — I —
Aluminate of
poUssium.

4. Bv mixing cryolite with rather more than f of its weight of quick lime, adding a
small quantity of water to slake the lime, then a larger quantity, and heating the
mixture by a current of steam. The products of this operation are fluoride of calcium
and aluminate of sodium :

Al*Na>F« + 3CaK) = 6CaF + Al^a«0»

Cryolite. Aluminate

of sodium.

The aluminate of sodium is decanted from the heavy deposit of fluoride of calcium, and
decomposed by carbonic acid as above. If any insoluble aluminate of calcium should
be formed, it may be decomposed by digestion with carbonate of sodium. (Deville.)
5. The slag obtained in the preparation of aluminium frx)m chloride of aluminium
and sodium, with fluor-spar or dyolite as a flux (p. 150), contains about 40 per
cent of fluoride of aluminium, together with soluble chlorides ; and the residue of the
extraction of sodium by Beville's process (see Sodium), which consists in igniting a
mixture of carbonate of soditmi, carbonaceous matter and chalk, contains about 14*5 p. c.
carbonate of sodium, 8'3 p. c caustic soda^ and 29*8 p. c. carbonate of calcium. Now, by
heating to redness a mixture of 6 or 6 pts. of the sodium-residue with 1 pt. of the
aluminium-slag, freed by washing from the soluble constituents, and lixiviating
the product after cooling, a solution of aluminate of sodium is obtained which may be
decomposed by carbonic acid as above. (D ev il le.)

Alumina prepared by an^ of the preceding processes contains iron. From this it
may be purified by dissolving it in caustic alkali and precipitating the iron* by a
stream of sulphuretted hydrocen (Deville). It may then be reprecipitated by car-
bonic acid. The alumina tibus precipitated always contains a certain quantity of

* This process, tlie Inrention ofM. Lp Chateller of Paris, is patented in thii coancxy tu the Mme of
H. F. Newtoo, 1858, No. 1988, and 18A'j, No. 957.

ALUMINIUM (OXIDES AND HYDRATES). 159

ilkalme earbonftte, irhich cannot he removed by washing with water. It may, how-
erer, be separated by digestion, with the aid of heat, in a small quantity of dilute
hydrochloric or nitric add, or by digestion with chloride of aluminium in excess.
(LeC ha teller.)

Aitifldally prepared alumina is white, and if it has been exposed only to a moderato
led heatk is Texy light and soft to the touch ; but after strong ignition, it cakes
together, becomes so hard as scarcely to be scratched with a file, and emits sparks
vhen stroek with steeL According to M. Bose (Pogg. Ann. Ixxiv. 430), the specific
carity of alumina ignited over a spirit-lamp is between 3*87 and 3*90 ; after six
Souls' ignition in an air fdmace, it is between 3*726 and Z'76 ; and after ignition in a
ponxlain furnace, 3*999, which agrees Teiy nearly with that of native corundum.

Alumina is infusible at all temperatures below that of the oxy-hydrogen flame ; but
at that degree of heat» it melts into transparent globules which assume a crystalline
glwclure on cooling. If a small quantity of chromate of potassium be added before
foaon, the melted alumina on cooling retains a deep red colour, and resembles the
DStaral ruby. When a mixture of 1 pt. of alumina and 3 or 4 pts. of anhydrous
borax is exposed for a considerable time to the hi^h temperature of a porcelain fur-
nace, the ahimina dissolves in the fused borax, and as the borax is volatilised by the
heat, remains in crystals resembling corundum ; in this case also, the addition of a
Toy small quantity of chromate of potassium causes the crystals to exhibit the colour
of the ruby. This method is applicable to the artificial formation of a great number
of crystalhsed minerals. (Ebelmeo, Ann. Ch. Phys. [3] xxii. 211.)

Aiumina is not decompoeible by heat alone. Potassium at a white heat deoxidises
it partially, forming an alloy of potassium and aluminium which decomposes water.
It IS not decomposed by chlorine at any temperature, unless it be mixed with charcoal,
in irhich ease a chloride of aluminium is produced.

Anhydrous alumina is perfectly insoluble in water. After strong ignition, it is like-
vise insohible in most acids, concentrated hydrochloric or sulphuric acid being alone
able to dissolve it. In the crystallised state it is insoluble in all acids. It may, how-
erer, always be rendered soluble by fusion with hydrate of potassium or sodium.

Htdra-TES of ALxmiBiiult, or of Alttuina. These compounds are three in num-
ber, viz.:

Monohydrate .... A1«H0* or APO^MO.

Dihydrate Al^HW „ AP0*.2H0.

Trihydrate Aim'G* „ APO».ZHO.

The numohydrate is found native as Diasporey a mineral which forms translucent
granular masses of specific gravity 3*43, and crumbles to powder when heated, but
does not give off the whole of it« water below 360^ C. It is insoluble in water, and
eren in boiling hydrochloric acid.

The irikydraU is the ordinary gelatinous precipitate, obtained by treating solutions
01 aluminium-salts, alum, for example, with ammonia or alkaline carbonates ; it is also
thrown down from the same solutions by sulphide of ammonium, the aluminium not
entering into combination with the sulphur. When dried at a moderate heat, it forms
a soft finable mass, which adheres to the tongue and forms a stiff paste with water,
bak does not dissolve in that liquid. At a strong red heat, it parts with its water, and
nndezgoes a very great contraction of volume. It dissolves with great facility in adds,
and in the fixed caustic alkalis. When a solution of alumina in caustic potash is
exposed to the air, the potash absorbs carbonic acid, and the trihydrate of aluminium
is then deposited in white crystals which are but sparingly soluble in acids.

The trihydrate of aluminium has a very powerful attraction for organic matter, and
when digested in solutions of vegetable colouring matter, combines with aod carries
down the eolouring matter, whidi is thus removed entirely from the liquid if the
alumina is in sufficient quantity. The pigments called lakes are compounds of this
nature. The fibre of cotton impregnated with alumina acquires the same power of
retaining colouring matters ; hence the great use of aluminous salts as mordants to
produce fast colours. (Sec Dyeino.)

Trihvdrate of aluminium occurs native as GibbnUf a stalactitic, translucent, fibrous
minenJ, easily dissolved by acids.

JHkvdraU of Aluminium, A1«H^0», or A1<0«,2H»0.— When a dilute solution of diace-
tate of aluminium is exposed for several days to a temperature of 1 00^ C. in a close vessel,
the acetic add appears to be set free, although no precipitation of alumina takes place.
Ilie liquid acquires the taste of acetic acid, and if afterwards boiled in an open vessel,
gives off nearly the whole of its acetic acid, the alumina nevertheless remaining in
sohition. This solution is coagulated by mineral acids and by most vegetable acids,
by alkalis, and by decoctions of dye-woods. The alumina contained in it is, however,
no longer capable of acting as a mordant. Its coagulum with dyed-woods has the

160 ALUMO-CALCITK-ALUM-SLATE.

colour of the inf^ion, but is tnuuilucent and totally different from the dense opaqiiA
lakes which ordinary alumina fomm with the same colouring matters. On erapora-
ting the solution to dryness at 100^ C. the alumina remains in the form of dihy-
drate, retaining only a trace of acetic acid. In this state, it is insoluble in the stronger
adds, but soluble in acetic acid, proTided it has not been previously coagulated in Sie
manner just mentioned. Boiling potash converts it into the trihydrate (Walter
Grum, Chem. Soc. Qu. J. yi. 225). The dihydrate is said to occur native at B^aux
(B er t h ie r, Schw. J. xxxiv. 164). Hydrargyllite^ a mineral occurring in regularsix-sided
prisms is also a hydrate of alummium, but its exact composition is not known.
(G. Rose, Pogg. Ann. xlviii. 664; L 656.)

Aluminates. — ^The hydrogen in trihydrate of aluminium, maybe replaced by
an equivalent quantity of various metals ; such compounds are called aluminaUa. Ac-
cording to Fr^my, a solution of alumina in potash slowly evaporated [out of oootMt
of air ? ] deposits granular ciystals of aluminate of potassium, Al*EO*, or Al^O*, K^.
Similar compounds occur native; thus SpineUia an iduminateof magnesium, Al'MgO';
Gahniiej an aluminate of zinc, Al'ZnO^.

Osyren-Salts of Almnlniuin. — The general characters of these salts have ali^y
been described (p. 164). The most important of them are the sulphate A1^(S0* »
with its double sulphates, especially common alum, the sulphate of aluminium and
potassium, and the silicates and double silicates. [For the detailed descriptions of
these salts, see the several Acids.]

Fbosplilde of Alnmlnliiin. — Obtained by heating pulverulent aluminium to red-
ness in phosphorus vapour. It is a dark grey mass, which acquires metallic lustre bj
burnishing, and is decomposed by water, with evolution of non-spontaneously in-
flammable phosphoretted hydrogen. (W o h 1 e r.)

SUicido of Almninlmn* — Aluminium combines readily, and in all proportioDa,
with silicon. When strongly heated in contact with any sihcious substances, such as
glass or porcelain, it reduces the silicon and unites with it. Nevertheless aluminium
may be fused in glass or earthen vessels, without undergoing the slightest alteratiooi,
provided no flux be used, because it does not then come into intimate contact with the
substance of the vessel ; but the addition of a flux produces instant decomposition.
The properties of the compoimd vair with the proportion of silicon. An alloy con-
taining 10*3 per cent, of silicon, called east aluminium {fonte cTaluTninium) is grey
and very brittle. A compound coiitaining 70 per cent, silicon, still exhibits me^ic
properties. All the compounds of aluminium and silicon are much more easily
altered by exposure to the air, or by the action of '*ids and alkalies, than either pore
aluminium or pure silicon.

Selenide of Aluinlntmn, Al^Se', or ^iSe'— I'roduoed with incandescence when
aluminium is heated in selenium vapour. It is a black powder, which acquires a
dark metallic lustre by burnishing, and is readily decomposed by water or by a moist
atmosphere, with formation of alumina and hydroselenic acid.

Bulpliide of Alrnnlntwin, A1*S', or APS*. — Sulphur may be distilled over alu-
minium without combining with it ; but when thrown upon the red-hot metal, it is ab-
sorbed with vivid incandescence (W o h le r). The sulphide may be prepared by passing
the vapour of disulphide of carbon over red-hot alumina. It is fusible, decomposes
water at ordinary temperatures, yielding hydrate of aluminium and hydrosulphuric add,
and thus perhaps contributes to the formation of natural sulphur springs. (Fr^my.)

AXiVMO-CAKCira. A mineral from Erbenstock, in the Saxon Harz, having
the appearance of opal. Specific gravity 2*1 to 2*2, scarcely harder than mica. Con-
tains, according to Kersten's analysis, 6*26 per cent, lime, 2*23 alumina^ and 40
water. It is probably a mere residue of decomposition.

AXiUM-SASTB.' A massive variety of aluminous schist, found in the neighbour-
hood of tertiary lignites, as in several parts of the valley of the Oder, on the Rhine,
in Ficardy, and other localities. It has not a distinct slaty structure, but is a soft,
friable, usually dark brown mass.

A&UBK-4IZJLTB. A clay slate, containing bitumen and sulphide of iron, gene-
rally found in the transition-strata, but sometimes in more recent formations. It is
found in the north of England and in Scotland, in Scandinavia, in the Han, in the
Ural, the Vosges, the lower Rhine, and other localities. There are two varieties of it,
-Hz. 1. Common, This mineral occurs both massive and in insulated balls of a greyish-
black colour, dull lustre, straight slaty fracture, tubular fragments, streak coloured liko
itself Though soft, it is not very brittle. Effloresces, acquiring the taste of alum.

2. Glossy Alum-slate, A massive mineral of a bluish-black colour. The rents dis-
play a yanety of lively purple tints. It has a semi-metallic lustre in the fraetnrey

ALUNITE — AMARINE. 161

•wJiielk 18 stnighty alatj, or nndnlating. There ifl a soft Tariety of it, approaching in
ipppuaiiee to slate day. By eszposure to air its thidmess is prodigioosiy augmented
tj the formation of a saline effloresence, which separates its thinnest pL&tes. These
aftcnnuds exfoliate in brittle sections^ causing entire disintegration.

ji&UfllTJif or AX1IJIK-8TOVSL A basie sulphate of aluminium and potas-

finm, A1*K:2S0* + 3A1»H*0» or ^^ | 4S0« + 3(A1^0".3H«0), found chiefly in vol-

euoc districts, tiz. at Tolfia^ near Ciyita Yecchia, at Solfatara, near Naples, at Puy do
Oaicey, in AuTeigne, and other localities. Used for the preparation of Roman alum.
It is either massive or crystallised ; the former is usually greyish white, and some-
times red. It is translacent, easily frangible, scratches calcareous spar, but is scratched
by floor spar. The crystals are genendly situated in the cavities of the massive sub-
alanee, they are small, shining, sometimes externally brownish, their form is an obtuse
ihomboid, variously modified. The crystals have the composition above given : the
Tsriety contains in addition a considerable quantity of silica.

Native sulphate of aluminium. (See Sulfhatbs.)

A combination of mercoiy with another metaL (See Mrrcubt.)

r. The process of extracting gold and silver from their ores
by difisohing them out with mercuiy. (See Gou> and Silvbb.)

flWflTiTC ACIB (fr^m dtftaxSs, 8ofif on account of its feeble acid reaction.) — A
prodact of the decomposition of caffeine by chlorine ^see Caffbimb), discovered by
Boehleder. Its composition is that of alloxantin, having the whole of its hydrogen
replaced by methyl : O«(CH*)*N*0' + BPO.

It forms transparent colourless crystals, which do not give oflf their water at 100° C.
At a higher temperature, it melts and volatilises, leaving scarcely a trace of charcoal,
but giving off ammonia, and yielding an oil and crystallised body. It slightiy reddens
litmus, and raoduoes red stams on the skin, imparting to it an unpleasant odour, like
allozantin. It reduces silver-salts like alloxantin. Nitric acid converts it into a ciys-
taUine substance. When exposed to vapour of ammonia, it gradually assumes a deep
Tiolet colour, and forms a compound which dissolves in water with the colour of
mmexide : the solution yields a crystalline body, to which Boehleder gives the name
matxoin. With baryta, potssh, and soda, it forms compounds of a deep violet
eokiir.

An organic base obtained by Letellier from the fly agaric {Agari'^
CH9 nvxarius, or Amanita mvscaria), and from. Affarictts btUbasuSt and supposed by him
to be the poisonous principle of these agarics. According to Apaiger and Wiggers, on
the other hand, the fl^ agaric contains a peculiar acid (muscaric acid), as well as a
base, and it is to tlie acid that the poisonous aetion is due. (Handw. d. Chem, 2** Aufl.
L 663.)

AXABZVS. CH'^N*. Senzoline, Pikramiiij Hydru/re cTasobenzailine, — (L a u r 0 n t ,
Ann. Ch. Phys. [Z] L 306 ; Fo wnes, Ann. Ch. Pharm. liv. 363 ; Gossmann, Ann.
GL Pharm. xdiil 329 ; Gm. xii. 193.)

This compound was discovered simultaneously by Laurent and by Fownes. It is
isomeric wiui hydrobenzamide, from which it is generally prepared. 1. When hydro-
benzamide is heated for three or four hours to 120° — 130° C, the vitreous mass, when
eool, dissolYed in boiling alcohol, and excess of hydrochloric acid added, white crystals
of faydrochlorate ofamarine separate out (Sertagnini). — 2. Hydrobenzamide is
boiled for some hours with caustic potash, the resulting resin dissolved in dilute sul-
pfamie add, the solution precipitated by ammonia, and the precipitate washed with
water and crystallised from hot alcohol (Fownes). — 3. A solution of bitter-almond
Ml in alcohol, when saturated with gaseous ammonia, solidifies in 24 — 48 hours into
a crystalline mass. This is boiled with water, and saturated while hot with hydro-
chloric acid, when an oily substance separates out, together with crystals of a peculiar
add (see Bkkzimic Aced). The hot solution is decanted, and the residue again
otiadted with boiling water, until all the hydrochlorate of amarine is dissolved out.
The solution is precipitated by ammonia ; and the precipitate is washed, dissolved in
boiling alcohol, mixed with hydrochloric add, and reprecipitated by ammonia : pure
amarine then crystallises out (Laurent). — 4. When the dry compound of bitterv
almond oil and add sulphite of ammonium is heated in a large retort to 180° — 200°
with 3 or 4 times its volume of slaked lime, amarine and lophine distil over. The
fiirmer, which collects partly in the receiver, partly in the lower part of the neck of
the retort, is dissolved m alcohol, and purified as in the former process. (Gossmann.)

Amarine crystallisee from alcohol in shinins six-sided prisms. It melts at 100° C.
and solidifieB to a vitreous mass on cooling : "^en heated more strongly, it volatilises

Vol. L M

162 AMARONE.

almost completely, ammonia being evolred : an oil smjelling like benzol distilfl over, and
a sublimate collects in the neck of the retort, which Fownes calls wrobensdliney and
which, according to Laurent, is identical with lophine. Amarine is inodorous, taste-
less at first, but afterwards slightly bitter. It is insoluble in water, solnble in al-
cohol and ether ; the alcoholic solution is strongly alkaline. Amaiine becomes stronslj
electrical by friction. Unlike its isomer, hydrobenzamide, it exerts a poisonous action
on animals.

Amarine is readily attacked by bromine, hydrobromate of amarine being formed
together with a resinous mass. When it is boiled with a mixture of sulphuric and
chromic acids and water, a brisk action takes place, and benzoic acid is abundantly
formed. Nitric acid acts similarly, but less yioiently. Fused potash does not attack
it, save at a very strong heat

Amarine-salta are formed by the direct combination of amarine with adds. Witii
the exception of the acetate, they are all but slightly soluble. The hydrochloTaie^
C^*H*"N^HC1, crystallises in small shining needles, which effloresce in Tacua, or when
heated to 100^. When hydrochloric acid is poured upon amarine, a colourless oil is
formed, which gradually solidifies on drying, and may be drawn into threads when
heated. It distils without decomposition, passing oyer as an oil which solidifies to a
transparent mass. It is soluble in alcohol and ether. The ohlcroplaiijiate separates in
yellow needles, when boiling alcoholic solutions of the hydrochlorate and of didiloiide
of platinum are mixed together. Fownes found in it 19*8 per cent pUi-tTinm ; the
formula PtCl.'C''H''N' requires 19*68 per cent. The aidphate cirstallises from an add
solution in small colourless prisms resembling oxalic acid. The nitrate is obtained
by treating amarine with hot dilute nitric acid ; a soft, amozphous mass is produced,
which dissolves in boiling water, and on cooling deposits smaU crystals, which remain
unaltered in vacuo. The acetate is veiy soluble, and yields on evaporation a gummy
non-ciystalline mass.

Diethylamarine, C"(C2H*)2H"N«. — Amarine heated with iodide of ethyl,
yields a crystalline salt, which is the hydriodate of this base. The base itself is ob>
tained by distUling the hydriodate with potash. It crystallises readily in oblique
rhombic prisms, is nearly insoluble in water, but dissolves readily in alcohol and ether.
It melts between 110° and 115^ C. but does not solidify again till cooled down to
70^. At a stronger heat it decomposes. The hydrochlorate crystallises in oblique
rhombic prisms. The platinum-saltf is a yellow powder, insoluble in water and in
ether, but soluble in alcohol, from which it crystallises in small prisms. (Borodine,
Ann. Ch. Pharm. ex. 78.)

Diethylamarine treated with iodide of ethyl yields the hydriodate of another orstal-
line base, probably triethylamaiine, which howeyer has not yet been analysed, and
this base again treated with iodide of etliyl, yields a third crystalline base. (B o r o d i n e.)

Trinitr amarine, C"H'*(NO«)«N« (Bertagnini, Ann. Ch. Pharm. IxxW 275).—
This compound is formed from trinitrohydrobenzamide, with which it is isomeric, just
as amarine is from hydrobenzamide. Trinitrohydrobenzamide is boiled with 1 toL
caustic potash of 46^ Baum6, and 60 vols, water; the resulting brown resinous
mass (which becomes brittle on cooling) is dissolved in hot alcohol ; a little ether
added ; and the solution is predpitated by hydrochloric acid. The hydrochlorate is
redissolved in alcohol, alcoholic ammonia added to the solution, and the predpitated
trinitramarine is washed with water, and recrystallised from alcohol Trinitramarine
is also obtained by heating trinitrohydrobenzamide in an oil-bath to 126^ — 130° C.

It crystallises slowly from its alcoholic solution in white hard nodules. It melts in
boiling water, and dissolves slightly, forming an alkaline solution. It is soluble
in boiling alcohol or ether, most readily in a mixture of the two. A hot satur&ted
solution deposits it on cooling as an amorphous powder.

Its salts are but sHglitly soluble in wat«r. The hydrochlorate separates in small
shining needles when hydrochloric acid is added to an alcoholic solution of trinitra-
marine ; it is nearly insoluble in cold, slightly soluble in boiling alcohoL The nitrate
crystallises in needles from boUing alcohoL An alcoholic solution of trinitramarine
forms with dicMoride of platinum^ smaU, yellow, heavy nodtdes insoluble in alcobd;
and with mercuric chloride, a somewhat crystalline predpitate.— F. T. C.

C'«H"N (Laurent, Eev. Scient. xviii. 207, &c).— A compound
formed by the dry distillation of azobenzoyl, benzoylazotide, or hydrobenzamide. The
sublimate obtained by heating benzoylazotide is washed with ether, and then freed
from lophine by boiling in alcohol containing hydrochloric acid ; the residue is washed
with alcohol, dried, crystallised from boiling rock-oil, and washed with ether. It forms
small, colourlt ss, inodorous needles, which melt at 233° C, and solidL^ to a radiated
mass on cooling. It is insoluble in water, slighUy soluble in alcohol, more readily
in ether. It dissolves in cold sulphuric acid, with a fine blood-red colour, which di*-

AMARYL— AMBER 163

a|ipean on idditioii of water, the amarone separating ont. It dissolres sparingly in
hot nftrie add, and ciTstallises unchanged on cooling. It is not decomposed by bouing
vitli alooholie potash. -F. T. C.

A name given by Laurent to a substance which he afterwards found
to be impure nitrate of lophine.

ByjL with Sbtthbin-bittbb or Ficbo-ebtthbin,

SjJL with ISiAMZDB.

Compact Felspab.

B. A variety of orthoclase, coloured green by eopper. It is
finnd chiefly in the shores of Lake Hmen in Bussia, also in Norway. It is used fbv
making trinkets.

mtlM. Succin, EUcirum, Ambra flava^ Bematein, AgUteiii, gdbea Erdhare. —
A hard brittle tasteless substance, sometimes perfectly transparent, but mostly semi-
tranqnrent or opaque, and of a glassy surface | it is found of all colours but chiefly
yellow or orange, and often contuns leaves or insects. Its specific gravity varies from
I'Otto to 1*070 ; hardness 2 to 2*5 ; slightly brittle ; fracture conchoid^. It is susceptible
of a fine polish, and becomes cdectric by friction : hence the word electricity (from
4\iicr^, amber). When rubbed or heated, it emits a peculiar smelL It is insoluble
in water and alcohol, though the latter, when hip;hly rectified, extracts a reddish colour
from it It is soluble in sulphuric acid, to which it imparts a reddish purple colour,
intiareprecipitatod on addition of water. No other add dissolves it, nor is it soluble
in esBential or expressed oils without decomposition ; but pure alkalis dissolve it.

Aceoidinff to Benelius, amber contains a volatile oil, succinic acid, and two resins
aoluUein uoohol and ether. According to Schroetter and Forchammer, amber when
decriTed by ether of all its sohible constituents^ possesses the composition of camphor

The diy distillatioii of amber presents three distinct phases, characterised by the
nature of the products. When submitted to the action of heat, amber softens, fdses,
intanMsees considerably, and gives oiS succinic acid, water, oil, and a combustible
g»L If now the residue {Coiopkony of Amber) be more strongly heated, a colourless
oil passes over. Lastly, when the residue is completely charred, and the heat is raised
tin the glass nearly fuses, a yellow substance sublimes of the consistence of wax.

The oil thns porodaced is a mixture of several hydrocarbons. The more volatile portion
wnich passes over between 110° and 260'-' C, is decomposed in the cold by sulphuric acid,
andooloQied bhie by hydrochloric acid, and by chlorine ; the less volatile portion produced
\jj a heat approaching redness, begins to boil at 140°, and then rises to 300° ; sulphu-
ric and hydrochloric add and duorine do not al£er it. According to Pelletier and
Walter (Ann. Ch. Phys. [3] ix. 89), these oils present the composition of oil of
tmpentine, containing 88*7 percent of carbon, and 11*3 of hydrogen.

The erade mixture of the two oils is used in pharmacy under the name of oil of
amber, being in fact one of the constituents of Eau de LiicCf a preparation sometimes
used as a remedy for the bites of venomous animals, and consisting of 1 part of oil
of unber, 24 of iJeohol, and 96 of caustic ammonia.

The wax-like solid which passes over in the diy distillation of amber is a mixture
cf oil, yellow matter, a white crystalline substance, and a brown bituminous substance;
these bodies are separated bv treatment with ether and alcohol. The yellow matter
tffam to be identi<»l with chiysene (C 94*4, H 6*8). It is scarcely soluble in
boiling alcohol and ether, is pulverulent rather than crystalline, and requires for
fasion a temperature of 240° C.

The white matter (suocisterene) is tasteless and inodorous, it is scarcely soluble in
cold alcohol, but little soluble in ether, but more soluble than the yellow matter; it
bmHs between 160° and 162°, and distils above 300°. Nitric add resinises it
in the oold. It contains, according to Pelletier and Walter, 96*6 per cent, of carbon
■nd 6*6 of hydrogen.

When amber is treated with faming nitric add, a resin is formed (artificial musk)
whidi ii soluble in an excess of nitric acid, and contains C^H^'NH)'.

When powdered amber is distilled with a strong solution of potash, a watery liquid
paasea over, together with a white substance which exhibits all the properties of com-
■on camphor.

Amber ooeors plentifully in regular veins in some parts of Prussia, espedally between
ftjhnnicken and Grosa-Hubenicken. In East and West Prussia there is scarcely a
tiSa^ where it has not been fbund and thence it extends into Mecklenburg and Hol-
itaan and in fact along the whole Baltic plain. It has likewise been found in southern
Germany, in France, Italy, Spain, Sweden and Norway ; also on the shores of the

164 AMBERGRIS — AMBLYGONITE.

Caspian, in Siberia, KamtschatJui, China, Hindoostan, Madagascar, North AmerieA
and Greenland. In Britain it is thrown out by the sea on the shores of Norfolk, Suffiilk
and Essex, and has also been found in the sands at Kensington. In the Boyal Cabinet
at Berlin there is a mass of 18 lbs. weight, supposed to be the largest ever found.

Haiiy has pointed out the following characters by which amber may be distin-
Kuished from mellite and copal, the bodies which most closely i«semble it. Hellite
IS infusible by heat; a bit of copal heated at the end of a knife takes fire, melting
into drops, which flatten as they fall; whereas amber bums with spitting and frothing^
and when its liquefied particles drop, they rebound from the plane which reoeiTes them.

Various frauds are practised with this substance. Neumann states as the common
practices of workmen the two following : The one consists in surrounding the amber
with sand in an iron pot, and cementing it with a gradual fire for forty hours, some
0mall pieces placed near the sides of the vessel being occasionally taken out forjudging
of the effect of the operation. The second method, which he says is that most generally
practiced, is to digest and boil the amber about twenty hours with rapeseed oil, l^
which it is rendered both dear and hard.

The chemical properties and mode of occurrence of amber leave no doubt of itj
being the produce of extinct coniferse. It has been found encrusting or penetrating
fossil wood exactly like resin at the present day, and enclosing the cones and leaves of
the trees. Numerous insects, the inhabitants of these ancient forests have been em-
balmed in it. To the tree which principally produced it, Goppert gives the name of
Pinites sticcini/erj but there was probably more than one species. Amber is often
stated to occur in the brown coal beds of Northern Germany, but Goppert stat^ that
he knows of no instance of this, the substance found in those beds being retinite.
(Handw. d. Chem. 2te Aufl. ii. 972; Dana, ii. 466 ; Gerh. iv. 394).

ABEBSROKZS. {Ambra^ Ambra grisea), is found in the sea, near the coasts of
various tropical countries ; and has also been taken out of the intestines of the sperma-
ceti whale (Physeter maorocephalus). As it has not been found in any whaks but
such as are dead or sick, its production is generally supposed to be owing to disease,
though some have a little too positively affirmed it to be the cause of the morbid
affection. As no large piece has ever been found without a greater or smaller quantify of
the beaks of the sepio octapodia, the common food of the spermaceti whale, interspersed
throughout its substance, there can be litUe doubt of its originating in the intestines
of the whale : for if it were merely occasionally swallowed bv the animal, and then
caused disease, it would much more frequently be without these bodies, when it is
met with floating in the sea, or thrown upon the shore.

Ambeigris is fbund of various sizes, general^ in small fragments, but sometimes so
large as to weigh near two himdred poxmds. When taken from the whale, it is not so
hard as it afterwards becomes on exposure to the air. Its specific gravity ranges from
0*780 to 0'926. If good, it adheres like wax to the edge of a knife with which it is scraped,
retains the impression of the teeth or nails, and emits a £fit odoriferous liquid on being
penetrated witn a hot needle. It is generally brittle ; but, on rubbing it with the nail,
it becomes smooth, Uke hard soap. Its colour is either white, black, ash-coloured,
yellow, or blackish ; or it is variegated, namely, grey with black specks, or grey with
yellow specks. Its smell is pecuuar, and not easy to be counterfeited. At 62*2 C.
it melts, and at 100 C. is volatilised in the form of a white vapour; on a red-hot
coal it bums, and is entirely dissipated. Water has no action on it; acids, except
nitric acid, act feebly on it ; alkalis combine with it, and form a soap ; ether and the
volatile oils dissolve it ; so do the fixed oils, and also ammonia, when assisted by heat;
alcohol dissolves a portion of it.

The principal constituent of ambergris is ambrein (q. v.) Succinic and benzoic
acids are said to be sometimes found among the products of its destructive distillation.
Its inorganic constituents are carbonate and phosphate of calcium, with traces of ferric
oxide and alkaline chlorides.

An alcoholic solution of ambeigris, added in minute quantity to lavender water,
tooth powder, hair powder, wash balls, &c communicates its peculiar fragrance. Its
retail price being in London a guinea per oz. leads to many adulterations. These
consist of various mixtures of benzoin, labdanum, meal, &c. scented with musk. The
greasv appearance and smell which heated ambergris exhibits, afford good eriUria^
joined to its solubility in hot ether and alcohol

It has occasionally been employed in medicine, but its use is now confined to the
perfumer. Swediaur took thirty grains of it without perceiving any sensible effect. — U.

AMBXiTOO VITB. A greenish-coloured mineral of different pale shades, marked
on the surface with reddish and yellowish-brown spots. It occurs massive and arstaUised
in oblique four-sided prisms. Lustre vitreous ; cleavage parallel to the sides of an
oblique four-sided prism of 106® 10' and 77*^ 50' ; fracture uneven; fragments rhom-
boidal; translucent; hardness as felspar; brittie; specific jgravity 3*0: intomescea

AMIC ACIDS 165

vitli the blowpipe, and foses with a reddish-yellow phosphorescence into a white
cnameL It oocara in granite, with green topaz and tourmaline, at Chursdorf and
Aniadorf, near Pinig, in Saxony. A specimen from Arsndorf analysed by RammeLsberg
gave 47*16 phosphoric anhydride, 88*43 alumina, 7*03 lithia, 3*29 soda» 0*43 potaah.
and 8*11 ihioEine^ agreeing reiy nearly with the formula:

(5A1*0».3P*0» + 5M»0.3P*0*) + 2 (A1«F» + MF.)

(HandworL d. Chem. 2m Aufl. L 665 ; Dana, iL 409.)

A — ^**™*— By digesting ambergris in hot alcohol, specific graTity 0*827, the
peculiar anbatanoe, eiUled ambrein by Pdletier and Cayentx)u, is obtained. The alcohol,
on oocJing, d^KMita the ambrein in Tory bulky and iiregojar crystals which still retain
a verj eonaiderable portion of alcohol. Thus obtained, it has the following properties :
— It is of a brilliant white colour, has an agreeable odour, of which it is deprived by
xepeated solntion and oystallisation. It is destitute of taste, and does not act on
Tegetable blnea. It is insoluble in water, but dissolyes readily in alcohol and ether ;
and in mnch greater quantity in these liquids when hot than when cold. It melts at
90^ C. (86° F.) BofleBing at 26*^ C. When heated aboye 100° C, it is partly volatilised
and decomposed, giving off a white smoke. It does not seem capable of combining
with an alkali, or of being saponified. When heated with nitnc acid, it becomes
green and then yellow, eliminates nitrous gas, and is converted into an acid, which
has been called ambrde acid. This acid is yellowish white, has a peculiar odour,
veddena vegetable bines, does not melt at 100° C, and does not evolve ammonia
when decomposed at higher temperatures. It ia soluble in alcohol and ether ; but
flUigfatly so in water, iumbreate of potassium forms yellow precipitates with chloride
of ealcinm, protosnlphate of iron, nitrate of silver, acetate of lead, corrosive sublimate,
protochloride of tin and chloride of gold. (J. Pharm. v. 49.)

Ambrein is perhaps impure cholesterin, which substance it greatly resembles in its
properties. Pelletier (Ann. Ch. Pharm. vL 24) found it to contain 83*3 p. c C,
13*3 H, and 3*82 O, which is nearly the composition of cholesterin : if this be so,
ambreie add is probably identical with cholesterlc acid.

A name applied to the ethers of the amic acids, e. g. oxamethane
to «««»^*^ of ethyL (See Aiao Acms.)

AM W U I ST. The amethyst is a gem of a violet ooloup, and preat brilHancy,
said to be as hsord as the ruby or sapphire, from which it differs only m colour. This
is called the oriental amethyst^ ana is very rare. When it inclines to the purple or
rose colour, it is more esteemed than when it is nearer to the blue. These amethysts
have the same figure, hardness, specific gravity, and other qualities, as the best sap-
phires or nines, and come from the same places, particnlarly from Persia, Arabia,
Armenia, and the West Indies. The occidental amethysts are merely coloured crystals
of quarts. — U. (See QuAsn and Safphibb.)

A variety of Hornblende (j. v.)

Mountain flax. (See Asbestos.)

By this name are designated a class of nitrogenised acids, which
differ from the add ammoQinm-salts of polybasic adds by the elements of one or more
atoms of water; and which, under oertam circumstances, are capable of taking up the
elipfncnts of water, and regenerating ammonia and the original non-nitrogenised poly-
haiie add. They bear a considerable resemblance to amides in their modes both of
formation and of decompontion : bnt they differ from these bodies in possessing
inTariable and dedded acid properties, and in not deriving from the type KH*.

^th regard to tiieir constitution, amic acids are best regarded as deriving from
the double type NH',HK). They represent this type in which 2, 3, or 4 atoms of
hydngen are replaced by other radides, one of whicn must be the radicle of a polyba^io
add: and they maybe divided into 8 classes, according as 2, 8, or 4 atoms of hydrogen
are so replaced. In class 1, therefore, it is obvious that 2 atoms of hydrogen in
the tjpe must be replaced by 1 diatomic acid radide ; in class 2, three atoms of
hydrogen may be replaced by 1 triatomic, or by 1 diatomic and 1 monatomic add radide ;
and so on. No amic add is formed by the substitution of an acid radide of less than
2 atoms of hydrogen in the t^fpe: if 1 atom of hydrogen in NH',HH) be replaced bv
<he ndide of a monobade add, the only result is the formation of the ammonium-salt
cf that add, €.g,i

AcetyU AeeCate of

aiamoDium

166 AMIC ACIDS.

Neither can an amic acid be formed by replacing 2 atoms hydrogen in the type by
2 monatomic acid radicles ; for when benzoic anhydride is treated with ammonia^ the
2 atoms of benzoyl, each equivalent to H, do not remain combined, forming an amic add,
bat separate, forming 2 distinct compounds, benzamide and benzoate of ammonium:

(CH*©)'.© + 2NH« « N.CH»O.H* + CH'O.NH^.O
Benzoic anhyd. BetiMxaide. Benioateof amm.

But when a dibasic anhydride is treated with ammonia, the acid radicle, equiTalent to
H^ being indivisible, is incapable of separating so as to form two distinct oompoonds;
so that a single compound is neoessarily formed, the ammonium-salt of an amic add:

S0«.0 + 2NH« « NH«.SO«.H.O
Sulphuric Sulphamate of

anhyd. amm.

Hence it follows that a monobasic acid \& incapable of forming an amic acid : in fact
the possession of this property is perhaps one of the most Higfiti^iifthmg characteristica
of polybasic acids.

We now proceed to describe the modes of formation, properties, and reactions of
amic acids, dividing them into 3 classes, according as 2, 3, or 4 atoms of hydrogen an
replaced in the type.

ClaB8 1. They represent the ty^e NHHH HHO in which 2 atoms of hydrogen aza
replaced by one diatomic acid radicle :

Sulphamic acid NH.H.SO<.H.O

Carbamicacid NH.H.C0.H.0

Oxamicacid NH.H.CH)*.ttO

Succimamic acid NH.H.OH*0«.K0

They are formed — 1. By action of heat on the add ammoniam-ealt of a dibasic acid:

C*0«.(NH*)H.O« - BPO - N.H».C«0«.H.
Acid oxalate of amm* Ozamic acid.

In some cases, s. g, comenamic acid, NH'.CHK)'.H.O, prolonged boiling of the am-
monium-salt with water is sufficient.
2. By action of ammonia on anhydrides :

C"ff *0«.0 + NH» - NH».C"H'*0».H.O
Camphoric Camphoramlc add.

nphori
ihyd.

The best mode is to dissolve the anhydride in absolute alcohol, and to lead diy
ammonia into the solution. The reaction takes place with 2 iftoms of ammonia^ an amate
(if ammonium being formed.

8. By action of ammonia on aeid salts of organic radicles :

HI U

C'H*0.(CH»)H.O« + NH" « NH«.C*H*O.H.O + CBP.H.0

Acid talicylate of methyl. Sallcylamic acid. Methylic

(Methyl-salicylic acid.) alcohol.

4. By action of aqueous ammonia on ethers of dibasic acids. (Gerhardt^ Chim.
org. iv. p. 668.)

C»»H»«0« (C«H»)*.0» + NH« + H«0 « NH«.C»«H>«0«.H.O + 2/C«H».H.0\

Sebamicacid. \ Alcohol. /

6. Imides, boiled with dilute ammonia» take up H'O, and form amic acids : some
alkftlamides exhibit the same reaction :

N.C*H*0«.H + H«0 = NH».0*H*0«.H.O
Suocinimide. Succinamic acid.

AMIC ACIDS. 167

N.C*H*0«.Ag. + WO = NmC*H«0«.Ag.O

Argento-ffuocini- Succinamate of sllrer.

inlde.

& Some prixnuy diamides, boiled with mineral adds or alkaliSj take up H'O, and
foim amie adds^ or axnates of ammonium :

N«.OH*0«.H* + HH) = NH«.C*H*0«.H.O + NH«

Ifabiinide. Bfalamtc add.

(A»paragine.) (A«partic add.)

7. Some amic adds are farmed bj the action of hydrosulphuric add on nitro-conju-
gated

(?H*(NO«)OJa.O + 3H«S = NH'.(rH*O.H.O + 2BP0 + 33
Nitrobenxote add. Ozybenzamic add.

The add thus formed is commonly called benzamic acid ; an impoBsible name, as
heosDie add is monobedc We regard it as the amic acid of ozybenzoic acid,
t^^.H'.O*, a diatomic add, although it does not form add salts. Strecker regards
tbis amie add as phenylcarbamic add, NH.C*H*.CO.H.O.

CUui 2. Thej represent the type NHHH HHO in which 3 atoms hydrogen of are re-
pbeed ; (a) by 1 tnatomic add radide, (b) by 1 diatomic and 1 monatomic add radide,
(c) by 1 Hi«fi\min, add, and 1 monatomic basic radide.

a. 3H orv r^piaeed by 1 triaiomie acid radicU:

m m

Phoephamic acid, NH.PO.H.O, formed by the action of ammonia on phosphoric
anhydride:

P«0» + 2NH« ^ 2(N.HPO.H.O) + H»0.

b. 8H are replaced by 1 diatomic and 1 monatomic acidrTadide :

Benzoylnaicylamic add .... NH.0'H»O.C'H«O.H.O

Sulpbophenyl-sucdnamic add . . NH.G*H*SO'.C«H<0'.H.O.

Obtained by boiling eextain tertiazy amides with aqueous ammonia (Gerhardt and
Chioisa):

SolphoplMnyl-niediia- Sulphophenyl-taoeinainateofainin.

e. 8H are repiaeed by 1 batio monatomic and \ add diatomic radicle :

Eihylozamie add NH.C«H».C*0«.H.O

PhenylBulphamic (sulphanilie) add ... NH.(>H^SO<.H.O

Fhenybncdnamic (sucdnanilic) add . . . KH.CmC<H«0*H.O.

These oompounds (which may be called alkalamio adds) are obtained by the same
xeaetiona that serre ix the formation of adds of dass 1, a primary amine being sub*
stitoted Ibr ammonia:

L By heating the add salts of organic alkalis :

CH)«.N(CH«)H*.0« - H«0 = NH.CH».C«0« H.O.

Add oxalate of me- Metbyloxamic acid.

tbyUnin.

Sb By aetion of primary amines on dibado anhydrides :

C»ft«0».0 + N.C«E».H« » NH.C^» C«H«0«.H.O.
lyrolartaric Phenjlamioe. Phesylpxrotartramic acid,
mbjd.

u 4

16S AMIDES.

8. Bj heating alkalimides with dilute ammonia:

KC«H».C*H*0» + H'O = NH.O"H».C*H*0»SO.

PbeujlmaUunide. PhenylmaUiinic acid.

Class 8. They represent the Irpe NH'iH'O in which four atoms of hydrogen are
replaced by other radicles, one of which must be a polyatomic acid radicle. The onlv
known members of this class are a few phenyl-oompounds : phenylcitramic ad^

N.C«H*.C*H»O^H.O, is an example.

There are also certain nitrogenised acids, which either exist ready formed in nature^
or are products of the decomposition of other compounds, which we may regard as
amic acids. Thus glycoooll, C*H*NO*, is the amic acid of glvcoUic acid,C*H*O.H*0«,
and maybe written KH'.C^H'O.H.O. Hippuric, choleic, and other acids may also be
regarded as amic acids ; but their constitution is as yet but imperfectly understood.

Amic acids are distinct monobasic acids : they form well defined salts, which are
generally more soluble than those of the corresponding dibasic acids. They are mostly
solid, ciystalline, not Tolatile without decomposition. When heated, many of them
lose the elements of 1 atom of water, and are converted into imides: others arc decom-
posed into a dibasic anhydride and a primary amine. When boiled with mineral acids
or alkalis, they mostly take up the elements of 1 atom of water, and regenerate the
corresponding dibasic acid, and ammonia or a primary amine : in some cases, the mere
boiling of their aqueous solutions suffices for this reaction ; in others, fusion with soUd
potash is required :

NH.C«H».C^H*0*.H.O + H»0 « C^tf*0«.H».0« + N.OH'.H*

FhenyUuccinamic acid. Succinic add. Phenyiamtne.

With nitrous acid, many amic acids regenerate the corresponding dibasic add, with
evolution of nitrogen :

NH«.C*H*0».H.O + NHO« « C*fl*0«.H«.0« + N^ + BPO.

Malamic acid. Malic acid.

Like all decided acids, amic adds form ethers, t. e. salts of alcohol-radides. These
amic ethers are sometimes called urethanes (or amethanes), the former name having
been applied to the earliest discovered, carbamic ether. They are formed by the in-
complete action of ammonia en the ethers of dibasic adds :

C«0«.(C«H»)«.0» + NH» = NmC«0* C«H».0 + 0»H«.H.O.
Oxalic etber. Oxamic etiier. Alcohol.

They are isomeric with alkalamic acids. When boiled with water, acids, or alkalis,
they are converted into dibasic adds, alcohol, and ammonia :

NH«.C»0«.C«H".0 + 2HX) = C*0«.BP.O« + C«H».H.O + NH«.

Oxamic etber. Oxalic acid. Alcohol

Excess of ammonia converts them into primary diamides {q, v,) — F. T. C.

Amio Bases. This name may be given to a dass of bodies produced by the action
of ammonia on the oxides, or chloro- or bromo- hydrates of polyatomic alcohol-radides,
and which are related to the polyatomic alcohols in the same way as the amic acids to
the polyatomic aoids. Their leading properties may be expressed by representing
them as derived from a combination of the types NH* and H^O.

The following bodies belonging to this class are already known :

Anisamine, CH'^NO - (^g? |^; tTpejII^

Dianisamine, C"H»»NO» = ^^^^'|o«

Diglycolamine, CW»NO« = ^^H'^'jo^

Glyceramine, C»HWO« - ^^h^Mo«

Diglyceramine, C»H"NO» = ^^h^'|o«

Triglycolamine, O»H'*N0> -^ ^^) j^,; typo 3^^^ j

*yP® 2(H«o{

}

AMIDES. 169

Ammonia, NHHH, is capable, nnder certain circumstances, of ex-
Aanging each atom of its hjdrogen suocessiTely for a metal, or for a compound radicle,
add or basic, — thus giving rise to a numerous class of compounds, all denying from
the same type, KHHH. The earliest discovered of these compounds were some of
ihox in wluch one atom of hydrogen was thus replaced, e. g. NHHK, which was re-
guded as a compound of KH* (amidoffen) with potassium, N£[*K, and called amide of
potaasiom, analogous to the cyanide, CNK. In process of time, compounds came to be
oLcoTered, deriving £rom the type NHHH, in whicJi 2 or 3 atoms of hydrogen were
replaced bj metals or compound radicles, to which the name amide in its ori^nal sense
of a compound containing amidogen, NH", was plainly inapplicable ; accordingly these
componnds were designated by other names, imideSy niirtles, &c, the introduction of
▼hieh has caused considerable confusion, since they in no way indicate the common
dEHTation of all these eompounds.

Of late years attempts have been made, chiefly by Gerhardt, to remedy this confu-
BOD, by assigning to this numerous class of compoimds a rational constitution which
shall render evident their common derivation, and a nomenclature by which this con-
sdtation is at once expressed. These attempts have been attended with considerable
nuee» : and the dasisification adopted in this article is based upon that given by
Gerhardt and Chiozza (Ann. Ch. Phys^ [3] xlvi.), certain modifications being
introdneed where great-er clearness seems thereby to be attained.

Since the hydrogen in ammonia is capable of bein^ replaced either by acid- or by base-
radicles (simple or compound), the first obvious division of the compounds thus formed
is one based upon the nature of the radicle which has been substituted for hydrogen.
These compounds tbus fall into three great divisions :

1. Ammonias in which 1 or more atoms of hydrogen are replaced by an aoid-mdicle.
To this division we propose to confine the name of amides. In the case of each in-
dividnal member of the dass, the generic name is preceded by a prefix, which indicates
the particular add radide or resides contained in the compound, e,g. acetamide
K.OT«O.H«, diacetamide N.(C»H«0)«H, &c.

2. Ammonias in vhich 1 or more atoms of hydrogen are replaced by &z«f-radides.
This division we call amines. For examples of the nomenclature of individuals,
we may take potassamine^ N.K.H', ethylamine, N.C^^H', methylethylamine,
K.CH".C»H».H, &c.

8. Ammonias in which 2 or more atoms of hydrogen are- replaced by add- and
Aflw-iadides. This division we call alkalamides. Examples are ethylacetamide,
N.(?H».C?HK).H, phenyldibenzamide, N.C«H».(C'H»0)«.

This primary classification enables us to perceive in compounds deriving from the
type ammonia, NHHH, the same seriation of properties which was first pointed out
hj Gerhardt in the compounds deriving from the type oxide, OHH. As in the latter
ease, we have metallic oxides (bases) occupying the positive extreme, adds tiie negative
extreme, while the middle place is filled up by salts, containing at once an add- and
a base-radide ; bo in the former case, we have amines at the positive extreme, amided
at the negative, and alkalamides between the two extremes.

A fbruer ground for division is furnished by the fact that amides, amines, and
alkalamides may derive firom 1, 2, or 3 molecules of ammonia, according as they con-
tain monatomic, diatomic, or triatomie radides. Hence we have a further division of
amides into

1. Monanudes (or amides), deriving firom 1 mol. ammonia NHHH.

2. Diamidea „ „ 2 mols. „ N^H'H^H*.
8. Tnamides „ ,,3 mols. „ N*H«H»H».

The same subdivision applies to amines and alkalamides.

In eadi of these types, NHHH, N«H«H*H», N«H»H»H", one third, two thirds, or the
vhole of the hydrogen may be replaced by acid- orbase-radides : hence arises a further
division of amides, diamides, and triamides into :

1. Primary, in wh. } of the hydrogen is replaced, NAHH, N*A"H'H«, N"A"'H»H».

2. Secondary, in wh. } of the hydrogen is replaced, NA*H, N«(A")«H« N»(A'")«H«. .

3. Tertiary, in wh. the whole of the hydrogen is replaced, NA», N«(A")«, N»(A"')».

The nme subdivision applies to amines, and (partially) to alkalamides.

Having thus indicated the general principles of classification which we adopt, \re
BOW proceed to the more detailed consideration of amides, amines, and alkalamides.
It is not our purpose to give a complete list of these compounds, but merely to cit6 a
i»affident number of them to illustrate our classification ; and to enumerate the piiu'^
opal reactions by which the formation and decomposition of eadi group is effected.

170 AMIDES.

Amidbs.
L Mommldes or Amides.

1. Primary Amides, Thej represent 1 molecule of ammonia, in which I atom of
hydrogen ia replaced by a monatomic acid-radicle (of a monobasic add) :

Acetamide
Fropionamide .
Benzamide
Cyanamide
Snlphophenylamide

N.C5«H«0.H»
N.C»H*O.H«

N.CN.H«
N.C«H»80*.H«.

They differ from the ammoniam-salt of their adds in containing the elnnent of
I atom of water leaa :

Acet. amm. AceUmlde.

They are formed : 1. By the action of ammonia on anhydrides (Gerhardt).

(CH»0)«0 + NH» - (rH»O.H.O + N.CTH-O.BP
Benxoic anhyd. Bensoic acid. Benzamldt.

2. By the action of ammonia (Liebig and Wohler), or of carbonate of ammonium
(Gerhardt) on the chlorides of add-n^des :

CNa + NH» « HCl + N.CN.H«
Chloride of Cyanamide.

cyaDOgen.

This method is especially adapted to the formation of those amides which areinaolable
or nearly so, in water.

8. By the action of ammonia on ethers :

C«H»O.C»H».0 + NH» = C«H«0 + N.C«HK).H«
Acetic ether. Alcohol. Acetamide.

This method is peculiarly adapted to the formation of soluble amidffl. Glycerides,
with ammonia^ also yie^ an amide, and glycerin. (Berthelot)

4. Some primary amides have specie methods of foimation : e. g, benzamide is
formed by oxidising hippnric add with peroxide of lead :

C^*NO« + 80 « N.CH*O.H» + 2C0« + H*0

Primaiy amides are mostly solid and crystalline, easily fusible^ neutral to test paper,
volatile without decompodtion. Some of them, e, g, acetamide, combine with aads:
others e. g, benzamide, can exchange 1 atom of hydrogen for a metal, forming metallic
salts, or alkahunides. Thej are generally^ soluble in alcohol or ether : some in water.

SeacHoTu, — 1. Boiled with adds or with aUcalis (some with water), they take op
HH) and regenerate the acid and ammonia,

2. Treated with phosphoric anhydride, they lose H'O, and yield the oorrespondiitg
nitrile. The same reaction frequently takes place when they are passed in the state d
▼apour over caustic lime.

N.C*H»O.H« - H*0 - N.CH*

Acetamide. Aceto-

nltrlle.

3. Treated with petitachloride of phosphorus, they behaye as though they were
oxides, yielding oxychloride of phosphorus, and the chloride of the radide which the/
may be supposed to contain, if deriyed from the type HHO (Gerhardt) :

CH-N.H.O + Pa» « PC1»0 + HCl + (THW.a
Beniamlde. Chloride of

bcnasamyi.

The chloride thus formed is readily decomposed by heat, frequently bdow 100^ C.
into hydrochloric acid and the corresponoiDg nitnle, C'H^IsCn » HCl + N.CH'
(aceto-nitrile^.

4. With nitrous add they yield their corresponding add, with eyolution of nitrogen :

N.CH'O.H* + NO«H - NN + BPO + (7H«0«
Beniamide. Bensoic

add.

2. Secondary Amides, — They represent 1 molecule of ammonia, in which 2 atontf
of hydrogen are replaced : (a) by 2 monatomic add-radides. (b) by 1 diatomic add-
radide of a (dibasic add).

AMIDES. 171

§.B*tre replaced by 2 monatomic radides :

PiaceUmide N.(CH»0)«.H

Solphophenyl-benzamide .... N.G*H*SO'.CrH*O.H

Thej are formed: 1. By the action of chlorides of acid-radicles on pzimary amides,
cr their metallic salts (Gerhardt) :-

N.C^»SO« H« + (?H»0.a = Ha + N.<>H»S0».C^»O.H.

flolflio^iaiylamJde Chlorifle of SulphophenjI-beoiamlde.

bensojl.

2. Bj action of dry hydrochloric acid on primary amides, at a high temperature
(Streeker):

2(N.C«H»0.H?) + Ha » :NHHn + NjrC«H»0)*.H
AcHamide. Diaoetamide.

JkeiBe amides ai« readily selnhle in ammonia^ They exhibit acid properties, red-
douD^ litmus, and exchanging their remaining atom of hydrogen for a metal : the
metallic salts thus formed dissolve in ammonia, producing compounds which Gerhardt
Rguds as dialValamidfw, but which, as they contain only monatomic radicles, it ia
praiaps preferable to regard as monalkalamides containing a compound ammonium :

N.C«ffSO*.C?H»O.Ag. + NH« - N.C^«SO« CTEPCNAgH' (monalkahimide).

or N« C«H*SO«.C»H*O.Ag.H» (dialkahimide).

Aceordiog to Gerhardt (Ann. Oi. Phys. [8] liii), pentachloride of phosphorus acta
oo aeeoudary amides in the same way as on primary amides :

N.CTff»so».crHK).H + pa» - pa«o + Ha + N(C'H»xc^»so«)a

SnlplioplicnylbeDBainide. Chloride of ralphopbcnjl*

bexamldyL
md the dbkride fonned is decomposed by heat :

N (c^»)(c^»so«)a - N.c^» + (>Hso«.a

Benso- Chloride of

nitrile. lulphophenyl.

kB* an replaced by 1 diatomic radide. These are the bodies generally called
imideSf being regarded as containing imidoyen, NH. Though we rgect this view of
their eonstitotion, we retain the name for oonyenience sake.

Carbimide (cyanic add) N.(CO)''.H

Sucdnimide N.(C*H*0«)" • H

Camphorimide N.(C"H"0«)''.H.

Thej differ from the acid ammonium-salts of their adds by containing 2 atoms of

vtterlesi:

C*H*0*(NH*)H - 2H«D - N.C^H)».H
Acid sQcciniite of flucctnlmide.

ammontem.

They are formed much more easily than secondary amides (a) :

1. By heating the add ammomum-salts of dibasic adds.

2. By heating primary diamides :

N».C^<0\H* - NX««0«.H + NH».
SoodiuuBide. Suoclnlmide..

3. By healing amic adds (Laurent) :

N.a*H'*0«.H«.H.O - HK) + N.C»«H"0».H
Camphonmfe add. Camphoilinlde.

1 By heating dibadc anhydrides with ammonia:

OHW.O + NH* - H«0 + N.C*HH)«.H
Sucdnlc anhr- Sacdoimide.

dride.

Imides possess dedded add properties, and readily exchange their basic hydrogen
for a metal ; carbimide in £ict is identical with cyanic add.

BetfetionM, — 1. Boiled with adds or alkalis, they take np 2H'0 and regenerate the
^iibasie add and ammonia :

N.C*H*0«.H + 2H«0 - 0*H*0<.H» + NH«.

BeooiidaiT amides (a) also exhibit this reaction.
1 Boiled with mlnte ammonia, they form the ammonium-salt of the corresponding

N.C«H«0».H + NH*.HO - N.C«H«0«.H«.NH^O

Sucdnamate of anm.

172 AMIDES.

3. Tertiary Amides,— They represent 1 molecule of ammonia, in which all the
hydrogen is r^laced : (a) by 8 monatomic^ (b) by 1 diatomic and 1 monatomic, (c) by
I triatxxnic, aad-radide :

a. H* are replaced by 3 monatoTiao radidea :

Sulphophenyl-benzoyl-acetamide . . N.<>H»SO*.C»H»O.CHK).

5. H' are replaced by 1 diatomic and 1 monatomic radicle:

Snlphophenyl-Buccinamide . . . N.C^'SO^CC^H'O*)".

They are formed by the action of chlorides of acid-radicles on the metallic salts of
secondary amides (tertiaiy alkalamides) :

N.C^-SO«.C'HK)Jlg + C^'O.Cl - AgCl + N.C^-SO«.C'H*O.C«H«0
N.C*H*0*^ + (>H*S0«.C1 - Aia + N.C*H*0«.C^*SO«.

Their reactions are bnt little known. Boiled witb dilute ammonia, the amides of dasB
(fi) giye the ammonium-salt of the corresponding amic acid :

N.C^H*0».C«H»SO« + NH«.H.O « NC*H*0«.C«H»SO«.H.NH*.0.

Sulphophenyl-auccina- Sulphophenyl-ftucdaamate of

mide. ammonium.

c. H' are replaced by 1 triaiomie radicle. To this group, by their reactions and
mode of formation, the following mineral compounds belong :

N.(PO)'" . Gerhardt's biphosphamide (phoephorylamide) - PO*(NH<)H« - 3H«0
N.N.'" . Free nitrogen (Nitroso-nitrile) = NO«.NH* - 2HK)

N.(NO.r . Nitrous oxide. (Nitro-nitrile) = NO«.NH< - 2H«0.

n. Btamldes.

1. Prim aryJ) iami dee. — ^They represent 2 molecules of ammonia in which 2 atoms
of hydrogen are replaced by 1 diatomic add-radide.

Sulphamide N*.(SO«y'.H«

Oxamide N«.(C«OV.H*

Succinamide N«.(C*H*0«)''.H*

Carbamide (urea) .... N\(COy.R*

They differ firom the normal ammonium-salts of their acids in containing 2 atoms of
mrater less *

C«0*(NH<)« - 2HH) - N*. C«0«.H*
Oxalate of Oxankide.

ammoDiam.

They are formed — 1. By the action of ammonia on ethers :

C«OXC«H»)» + 2NH» - 2C*H«0 + N«.C»0*.H«
Oxalic ether. Oxamide.

2. By the action of ammonia on chlorides of add-radides :

C^H*0«.C1« + 2NH« = 2Ha + N«.C*H*0«.H«
Ctilortde of Succinamide.

succlnyl.

3. By heating normal ammonium-salts of dibasic acids (Dumas).

4. By the action of ammonia on imides (Wohler) :

N.CO.H + NH« « liP.CO.H*

Carbimide. Carbamide.

By the action of ammonia on dibasic anhydrides, not primaiy diamides, but omie
add^, are generally formed.

Many primary diamides exhibit decidedly basic properties, combining with acids
and formmg de&iite salts: e.y, urea, asparagine, &c

Reactions, — 1. Many of them, when heated, evolve ammonia and yidd imides.

2. Boiled with adds or allLalis, they take up 2H^, and regenerate the add and am*
monia:

mC«0«.H« + 2BP0 = CK)*.H« + 2NH».

3. With nitrous acid, they regenerate their dibasic add, with evolution of nitrogen
(Piria^ Malaguti):

N^.C^O'^.H* + 2N0'H - 2NN + C»0*.H« + 2H«0.
Oxamide. Oxalic acid.

Intermediate between primary and secondary diamides must be classed the bodies

AMIDES. 178

ktel7 diaooTered hj Zinin (Ann. Ch. Phys. [3] zliv. 57), which he describes as
vrw in which 1 atom of hydrogen is replaced by an acid radicle O^iey are of course
(tiamidffl^ in which 3 atoms of hydrogen are rephiced, 2 by a dia;tomic, and 1 by a mon-
itoime xadide.

Acetocarbamide (acetyl-urea) . , N'.CO.C'H^O.H*
Benzoearbamide (benzoyl-nrea) . . N*.CO.C'H*O.H».

Hmj are ibnned by the action of chlorides of acid-radicles on nrea:
IP.CO.W + C*HH).Cl « HCl + N«.CO.C*H»OH»

Carbamide. Cbloridn of Acetocarbamide.

acetyl.

Attempts to replace more than 1 atom of hydrogen in nrea by an acid-radide, have
bitheito &iled.

i These bodies are crystaUisable, and do not combine with addi. They are not
Tdatiky being decomposed by heat into cyannric acid and a primaiy amide :
8(K«.CO.C»H»0.H") « C'N»0*H« + 3(N.C2H«O.H«)
Acetocarbamide. CyaQuric acid. Acetamide.

Here too mnst be placed Gerhardfs phosphamide (Ann. Ch. Phys. [3] zyiii.) —
IPJlJ^yjP, formed by saturating pentachloride of phosphorus with ammonia, and boil-
ing witn water:

PC1» + 2NH» + HK) = N'.PO.H* + 6HCL

It diffen from monacid phosphate of ammonium by the elements of 3 atoms of water :

FO*(KK*yE - 3H»0 = N«.PO.H».

1 Secondary Di amides. — ^They represent 2 molecules of ammonia, in which 4
atoms hydrogen are replaced by 2 diatomic acid-radicles, or by 1 diatomic and 2
monatomic radidesL

None of these have yet been formed. (Handwb.)

8. Tertiary Diamides, — They represent 2 molecules of ammonia, in which all
tbe hydrogen is replaced by acid-radicles, one of which at least must be dibasic :

TrisMcinamide N»(C*tfO»)»

Sucdnyl-disulphophenyl-dibenzamide . N«.(C*H*0*).(C«H*SO«)*(C'H*0)«

The^ are formed by the action of chlorides of acid-radides on the silyer^salts of
8eeon<uiy amides :

2(N.C*H*0«.Ag) + C^H*0«.a« + N«.(C*H*0«)» 4- 2AgCL

Argentosoocioamlde. Chloride Trltuc-

of tuccinyi. dnamide.

in. Trtamldes.

1. Primary Triamides. — ^They represent 3 molecules of ammonia, in which 8
atoms of hydrogen are replaced by a tnatomic add-radide :

Phosphamide .... N».(PO)'".H«.
Citramide N«.(OH»0*y".H«.

They difSar from &e normal ammonium-salts of their adds by containing 35*0 less :

CflB[K)'(NH*)« - 3H«0 = N».C"H»0*.H«
Citrate of amm. Citramide.

Phoqihamide is formed hj the action of ammonia on oxychloride of phosphorus :
POCP + 6NH» = 3NHH31 + N».PO.H«. (Schiff Ann, Ch. Pharm. d. 300.)
Citramide is formed by the action of ammonia on dtric ether :

• C«a»0*.(C»H«)».0« + 3NH» = N».C«H»0*.H« + 3(C«H».H.O)
Citric ether. Citramide. AlcoboL

Heated with acids or alkalis, they take up 35*0, and regenerate their add and
ammonia.

1 Secondary Triamides. > They represent respectivdy 3 mols. ammonia, in which

8. Tertiary Trtamides, (two-thirds and the whole of the hydrogen is replaced
ly add-radides, one of which at least must be triatomic.

No member of either of these groups has yet been formed.

Oerhardt (Chim. oi*g. iy. p. 767) regards melam, C'H*N*, as a primaiy triamide^
N'.CN'.H* : and indeed we may admit the existence of a triatomic radicle, CN*, and
Kgard hydrocyanic acid as tribasic, CNII': otherwise such compounds as ferro-
cjaoide at potassium, C'N'FeK*, present the anomaly of bodies deriving from a triple
^pe (H'd'), and yet containing only monatomic racudesL

174 AMIDES.

Akinb8.
L Monmiwtnag or Amlniw.

1. Primary Amines. — They represent 1 molecule of ainmoiiia» in which 1 atom of
hydrogen ib replaced by a monatomic boae-radide, whether a metal or an organic
radide. They are sometimee called amide-boBea.

Potaasamine KKH*

Platinamine .
Methylamine .
Ethylunine .
Phuiylamine (Aniline)

N.PtH«.

N.CH».H«

N.C»H*.H«

Brimaiy amines contamiBaMiifitals are generally obtained by the action of ammonia
on the metal or its oxide. %ncamiDa ia formed by the action of ammonia on nno-
ethyl: ZnC*H» + NH" = RCH* + NZnH*.— When treated with water or adds,
they are mostly decomposed, like primary amides, yielding ammonia and the hydrate
of ike metal.

Primary amines containing organic radicles are formed :

1. By action of ammonia on hydrobromic or hydriodic ethers (Hof mann) :

CH«I + im» - HI + N.CH».BP
Iodide of MeChyUmlne.

methyl

2. By action of potash on cyanic or cyanuric ethers (Wurtz) :

N.CO.CH» + K*BPO« « CO.K«.0« + N.CH».H«

Cjanate of Carbonate of Metb jU

methyl. potatiium. amine.

3. By action of reducing agents, yiz. alkaline hydrosnlphates (Zinin), acetate of
iron (B 6 champ), on certam nitro-coxgngated hydrocarbons:

C^«(NO«) + H« - 2H«0 + N.C»H».H»
MitrobenseDe. Pheujlamlne.

Their formation is also observed in the dzy distillation of several nitrogenised organic
substances. (For the various modes of formation of monamines in general, primary,
secondary, and tertiary, see K^kul^, Lehrb. d. org. Chemie, pp. 451 — 466.)

These primary amines are mostly liquid, boiling at a low temperature^ and volatile
without decomposition. They strikingly resemble ammonia in all their propertiee:
like it they have a strong alkaline reaction ; thev combine directly with acids, forming
salts, whence they are expelled by the fixed aikaUs ; they precipitate metallic solu-
tions ; with anhydrides, ethers, and chlorides of acid-radicles, they react predsely like
ammonia (forming alkalamides, q.v.)^ and with hydriodic ethers they form «liMni^<w.
With nitrous acid they yield nitrons ether or alcohol, with evolution of nitrogen :

N.C*H».H* + 2N0«H « NN + 2H»0 + NO*.C»H»
Ethylamine. Nitroui ether.

N.C»H».H» + NO*H « NN + HH) + C«H«0

Fhenylamine. Phenylle

alcohol.

In this group must also be included those amines whose radicle contains dilorine,
bromine, iodine, or nitryl (NO'), substituted for 1, 2, or 3 atoms of hydrogen: e.g.
Dichlorethylamine, N.C*H»CRH«, Chlorophenylamine, N.Cra*Cl.H«, Dichlorpbe-
nyhunine, N.C«H«a«.H», Trichlorphenylamine, N.C»H«C1».H«, Nitrophenylamine,
lf.C'H\(NO^).H', &c Their alkaline properties are less marked, the greater the num-
ber of atoms of chlorine, &c they contain. They are formed mosuy either by the
direct action of chlorine, &c. on amines, or by the metamorphoses of other coiyugated
compounds. Nitrophenylamine is formed by the reduction of dinitrobepzene by
hydrosulphate of ammonium, just as phenylamine results from the reduction of nitro-
benzene by the same agent.

2. Secondary Amines. — They correspond to 1 molecule of ammonia, in which
2 atoms of hydrogen are replaced by two monatomic base-radides. They are sometimei
called Imide-bases,

Dimethylamine N.(CH»)«.H.

Methylethylamine .... N.CH«.C«H».H.
Ethylphenykmine .... N.(?H».0»H».H.
They are formed by the action of hydriodic ethers on primary amines :

N.CH».H« + CTa:»i m m + n.ch".c^.»h

Methylamine. Iodide of Methylethylamine.

ethyl.

AMIDES. 175

In pmwitiet and reafetioxis, they eloaelj resemble primaiy amines : but they are in
geDoaf leaf TobtQe.

We BntBt also regard as aeoondaiy amines two alkaloids, which have not yet been
failed arttfciany:

Piperidine N.(C»H»»)''.H.

Conine N.(C"H")''JBL

The diemieal relations of the radides contained in these componnds are as yet
vnknovn to ns ; and we cannot detennina wheflwr ^17 toe abgfe diatOBrie ndittB%
or vhether they aie BMida wp of two monatomic radicles.

S. Tertiary Amines, — ^They represent 1 molectde of ammonia, in which all the
liydrogen ia r(*placed : (a) by 3 monatomici {b) by 1 diatomic and 1 monatomic, (c) by
1 triatomic base-radicle.

0. H' lie replaced by 3 monatomic radicles (Nitrile-bases).

Tripofassaiaine N.K'

Tiimereoramine ^'^^

Trimethylaniine N.(CH»)*

Hethyldiethylamine N.CH».(Cra»)*.

Methylethylphenylamine .... N.CH».C*H».C«H».

Those eontaining oiganic radicles are formed — 1. By the action of hydriodie ethers
on aeeondaiy amines :

U.(CH»)«.H + C«HM - HI + N.(CH»)« C«H>.
DlnMChjUiniiM. Iodide of DlmelbjlethjbuniDe.

ethyl.

2. By the distillation of the salts of oiganic ammonimn-bases :

N.(CTI»)*.KO « N.(C^»)» + C«H* + HH)

Hydnte of Trietbyla- Stbylene.

tetretbyllnm. mine.

K(C»H»)M - N.(C*H»)« + C*H»L

Iodide of
tetrechyllam.

3. By action of ethylate of potassiom on cyanic ether:

N.CO.C*H» + (0«H»)*.K*.0« = N.(C«H»)« + CO.K«.0«
Cj»Mto of ethyl. 9 mol. eChyl«to TrtcthyU- Carboneiaor

of pocaumm. mlneL potaMimn.

TUs reaction is analogous to that of hydrate of potassium on cyanic ethers. (See

Terliaiy amines are generally similar in properties to primaiy and seoondair amines :
tiiey ue kss Tolatile than either. They are however distingnished by one important
nactioD, whiebi at the same time exhibits in the strongest lisht their analogy with
the ^rpe from which they are derired. When acted npon by hydriodie ethers, direct
combmation takes place, an iodide of an oiganic ammonium-base being formed:

N.(C*H»)« + C«HM « N(C«H»)M

Iodide of
tetrethyliam.

These iodides are usually crystalline, soluble in water and alcohol : when treated with
ends of sihrer, th^ yield iodide of silyer, and a hydrate of the ammonium-base :

2[N(C*H»)*.I] + AgH) + H«0 - 2AgI + 2[N(C*H»)*.H.O]

Hydrate of
tetreihyllam.

These hydrates are dystalline and soluble in water : they are powerfol alkalis ; in
some reactions they resemble the fixed alkalis, liberating ammonia from A^inTnAniiti>^i
■Its, and decomposing ethers into acid and alcohoL Precisely, therefore, as ammonia
(nitride of hydrogen) NH*, combines with hydriodie add (iodide of hydrogen) HI,
fetming iodide of ammonium, NH*I ; so triethylamine (nitride of ethyl) y(C%*)*,
eombmes with iodide of ethyl, C^*t forming iodide of tetrethylium, N(C^*)r[.
Jvit as we haye the hypothetical compound ammonium, NH^ playing the part of
potaasiam, sodium, and other metals, and replacing the basic hydrogen in adds to
form salts-— BO we liAye the hypothetical compound tetrethylium, I<r(C'H*), performing
predaely the same metallic ftmctions. The analogy could not be more complete.

6. IP are replaced by 1 diatomic and 1 monatomic radicle : Hofmann's ethylene-
phenylamine, N.(C»H*)<C«H».

176

AMIDES.

c. H* are replaced bj 1 txiatbmic radide (Nitriles).

Aoetonitrile (cyanide of methyl) N.(CTP)*'

Propionitrile (cyanide of ethyl) N.(C"H*)J

Benzonitzile (cyanide of phenyl) .... N.(C'H*)'".

They are formed — 1. By the action of heat or dehydrating .agente {e.g. phoepboric
anhydride) on ammoniacal salts of monobasic acids :

C«H«0«.NH* - 2HH) - N.C"H».
Acetate of amm. Acetonitrlle.

These nitriles differ £rom primary amides in containing H*0 less.

2. By the action of cyanide of potassium on sulphate of ethyl and potassiom (or a
liomologous salt), or on hydriodic ethers:

SO«.(C«H»).K.O« + CN.K
Sulphate of ethyl
and potaisluro.

SO«.K«.0« + CN.C*H»

Sulphate of Cyanide of
potastiom. ethrl or

propto^nitrlle.

This mode of formation shows that nitriles may also be regazded as cyanides
(N.C«H» - CN.CH«), denying from the type CIH : and it is in this light that they
are usually considered. But, if we consider their formation from ammoniacal salts,
and their behaviour when boiled with acids or alkalis, when they regenerate thnr
acid and ammonia,— NC«BP + KBO + WO - C«H»0*K + NH",— we may fairly
regard them as deriving irom the same type with amides. And we are led to consider
them as amines rather than as amides, by the fact that, in one of them at leasts the
radicle is clearly a basic one ; in propio-nitrile, N.CH*, the radicle is glyceryl^ the
triatomic radicle of the triatomic alcohol, glycerin, CHMI'.O'. Moreover, that they
resemble amines in the property of combining with acids, is shown by the componndb
which G^rhardt obtained by the action of pentachloride of phosphorus on primaiy
amides {a. v.) C^«NC1 = N.C'H» + HCl.

In order to show the connection between nitriles and the acids from whose
ammonium-salts they are formed, e.g, of acetonitrile N.C*H', with acetic add, 0^*0*,
and acetic compounds generally, it may be observed that acetic compoundis may be
represented as containing the triatomic radicle CH*. Thus acetic acid may be written
(C»H»)".H.O«, deriving from the double type H*0« : acetamide, N.H.C«fi».H.O, de-
riving from the double type NH" + H*0 : chloride of acetyl, CLC*H".0, deriving from
the double type CIH + ff 0 : acediamine, N^.CH'.H", deriving from the double type
N«H«.

We have already seen that, when an amine which contains* any replaceable
hydrogen (primary or secondary amines), is treated with the iodide of an organic basic
^radicle, the result is the replacement of the basic hydrogen by the organic radicle:
but that when tertiary amines, in which aU the basic hydrogen is already replaced, are
• similarly treated, the result is a direct combination of the iodide with tne amine.
Hence we are enabled to class as tertiary amines many natural organic alkalis, which
combine directly with organic iodides ; of whose constitution, as they cannot be formed
artificially, we should oSierwise be ignorant. Among these are tiie following homo*
logons alkalis, obtained by the dry di^illation of animal matter :

Pyridine

Picoline

Lutidine

Collidine

Parvoline

N.C»H»

N.CTI*

N.OTl"

N.C»H".

Also the numerous vegetable alkalis or alkaloids (quinine, strychnine, morphine, &c),
which have been extracted from plants. The migority of these latter compounds
contain oxygen-radicles : as many of them contain 2 atoms of nitrogen, it is possible
that they must be regarded as diamines. How many radicles they may contain, ve
have as yet no means of determining.

IL Blamlaes.

1. Primary Diamines. ) They represent 2 molecules of ammonia, in which

2. Secondary Diamine8,\2 and 4 atoms of hydrogen are replaced by 1 and 2
diatomic base-radicles. The only representatives of these groups are the compounds
lately obtained by Hofmann, by the action of bromide of ethylene on ammonia ; they
contain the diatomic radicle ethylene, C^H^ :

Ethylenamine N«.(ci*).H*

Diethylenamine N».(C«H*)«.H«.

AMIDES. 177

likqr are thus fbzmed :

C?H<.Br» 4- N«H« ■=- 2HBr + N«.C«H«.H*

Bromide EthjIeDamine.

of ethylene.

2C*H«Bi* + N*H« - 4HBr + N».(C%<)«.H«

Di-ethylenamlne.

latermediate between secondaxy and tertiary diamines, is Hofinann*s diplienjl-
lannTlmnine, N» (CH*)'.CH.H, obtained by the action of chloroform on phenywunine :
2(N.C«H*^ + CHOT = K«.((?H»)».CH.H + 3Ha.

3. Tertiary JKamines, — ^They represent 2 mols. ammonia, in which all the hydrogen
ia TCfilaced; (a) by 3 diatomic, (b) by 2 diatomic, and 2 monatomic base-radides.

a, Hofioann has obtained triethylenaminei; N'.(C%')*, by the reaction :

8C*H^r* + N*H» « 6imBr -h N».(C*H*)».

In thifl groop may be daaaed the compoimda known as hydramidea :

Benzhydramide (hydrobenzamide) . . • , N'.(C'^H')'

Salhydramide N».(C''H«0)«.

Thcj are obtained by the action of ammonia on certain aldehydes :

SCTHK) -t- N«H« « 8H»0 + m(C»H*)»

B^niolc al* Benshrdrft*

defayde* midie.

They are OTstalline, insoluble in water, soluble in alcohol, not Tolatile without
decomposition. They are decomposed by hydrosulphuric acid, yiddiog solph-aldehydes.
(Cabovrs.)

l^.CCH*)' + 3H«S - WE* + 3Cm«S.

The Tiew here taken of the constitation of hydrobenzamide is confirmed by its
Ibfnnation from chlorobenzol, CH*C1^ and ammonia (Engelhardt), by the manner
in which iodide of ethyl reacts upon it (Borodine), and by the existence of a number
of bodies obtained from chlorobenzol^ which may be regarded as the methyhite^
ethylate, acetate, Talerate, benzoate, &c. of the diatomic radicle CH*.

b, Hd&nann has obtained diethylene-diphenylamine, K*.(C*H^)'(G^*)', by the action
of cfakEEide of ethylene on phenylamine :

2(C«H*.C1*) + 2(K.CWB[».H') = 4HC1 + K«.(C*H*)*.(C^»)*.

Here too should probably be classed cyanogen, or oialo-nitrile, NK)*, which bears
the same relation to normal oxalate of ammonitim that acetonitrile does to acetate of
ammonium:

C«H»0*jra« - 2H«0 - N.C H«j
also nitride of boron, K^.

1. Primary.

2. Secondary.

3. Tertiary.
The only triamine known is Erankland and Kolbe's CyanetUne, (?H**N', which,

according to Ho&iann, should be regarded as tnglyceiylamine, N*«(G*b*)', a tertiary
triamine.

They represent 3 molecules of ammonia^ in which 3, 6, or 9 atoms
of hydrogen are replaced by 1, 2, or 3 triatomic basic radicles.

and Pfintamtnesg-r-We know but little of any complex ammonia-
molecules of a higher order than the. triamines ; nerertheless it appears that under
certain drcmnstanees, four, five, or even a greater number of atoms of ammonia are
capable of eoalescing into a complex molecule.

The only well characterised tetramines with wjiich we are acquainted are ylyeostne^
K*.C^*, a product of the action of ammonia on glyoxal, which may be regarded as

N\C?k*)*, and hexamethylenaminey N*»CfH", formed by the action of ammonia on

diozymethylene, which maybe written N*(CH*)» (Buttlerow, Bullet, de la Soc. Chim.
de Paris, i. 221.) There are also some natural bases containing 4 at. nitrogen, e. q,
caffine, C^»«N*0*, and ikeobroTnifie^ C'II*N*0», but we know nothing of the radicl'ed
which they contain.
Vol. I. N

17S AMIDES.

Pentamines appear to be produced by the action of anunoma on oertain metallia
oxides. Some of the ammoniacal compoondfl of cobalt appear to be of thia character ;
but further inyeatigation is necessary to give accurate ideas of their oonstitatioD.

Phosphines, Absinss, Stibinbs. — In connection with the basic deriTatiTes of
ammonium, we must also mention a class of bodies derived from pho^horetted hydrogen,
PH*, arsenetted hydrogen, AsH", and antimonetted hydrogen, SbK', by the substita-
tion of alcohol-radicles for the hydrogen. All the compounds thus formed, are basic,
like the alcoholic deriyatiyes of ammonia^ and form salts of exactly analogous charac-
ter. Up to the present time, however, the only phosphines, arsines, and stibines, that
have been obtained are those in which the whole of the hydrogen in the type ia
replaced by an equivalent quantity of an alcohol-radicle, e. g, :

Triethylphosphine P(C«H»)"

Trimethystibme Sb(CH»)"

These bases have not yet been obtained by direct substitution from the hydrides of
phosphorus, arsenic and antimony; but they are produced, either by submittinff a
metiulic compound of phosphorus, arsenic, or antimony to the action of the iodmea,
bromides or chlorides of the alcohol: radicles, e.g,i

Na'As + 8C»H»I - SNal +' Afl(C*H»)«
Triaodic Iodide of Triethyl-

•neDide. ethyl. anino.

or, better in most cases, by treating the metallic compounds of the alcohol-iadides
with the iodides, bromides, and chlorides of phosphorus, aiaenic and antimony; thos,

SCBPZn + Pa« » SZnCl + P(CH»)«

Zlnc-methyl. TrlmethjI.

phofphiD^

These compounds, when treated with the bromides or iodides of the alcohol-radidea,
behave exacUy like the corresponding nitrogen-bases, producing the bromides or
iodides of bases containing 4 at. of the alcohol-radicle and belonging to the ammoniTua
type : e, g.i

ViC^n^y + C'ffl . P{C»H»)«I
Triethyl. Iodide of Iodide of
pboepnine. ethyl. ethylphoe*

niuu.

P(CH")« + C«H»I « P(CH«WC^»)I.
Trtmethyl- lodlde'oftrinethyl-

photphine. ethyl.phoipbonium.

The phosphines treated with diatomic bromides (dibromide of ethylene, for example),
yield, among other products, the monobromide of aphosphonium-molecule, in which the
fourth atom of hycbogen is replaced by a brominated alcohol-radide ; thus triethyl-
phosphine, treated wiUi dibromide of ethylene, yields the mcmobronade of bromUn^
triethyl-phoBphonium :

T(C^Wy + CJ«H«Br« - P[(C^*Br)'.(C«H»)^Br.
(See Akmonittx-basbs.)

Alkalahides.
I. Mpnalkalamldes or Allra lamfd— ■

1. Secondary Alkalamides, — ^They represent 1 vol. ammonia in which 2 atom
of hydrogen are replaced, one by an acid, the other by a base radide.

Mercurobenzamide , N.Hig.C*H*O.H.

Argentosulphophenylamide ,
Etbylfbrmamide • • .
Ethylacetamide ....
Phenylbensamide (benzanilide) .
Ethylcyanamide •

N.Ag.C«ffSO«.H.

N.(^».CHO.H.

N.C«H»C«HK).H.

N.C«H».(?HK).H.

N.O«H».CN.H.

Those which contain metals are formed by the action of primary amides on metallic
oxides ;• they are decomposed bv most acids, which remove their metaL Those eon-
taining silver are readily attacked by chlorides of acid-radicles, yielding seoondaiy
amides and chloride of silver :

N.Ag.(?HSO» H + (m^O.Cl » Aga + N.C«H«SO*.C'H»O.H.

Argentoialphophe- Chloride of SuIpbopbeoylbensamMe.

DylamiaAi bentoyL

ATiKALAMIDES. 179

Tbon eoDtaiiiiiig oi]gaiiie iMse-ndides, are formed by the same naetions as primaiy
amides, a primaiy amine being substitated for ammonia :

1. ij action of pcimazy amines on monobasio anhydrides (Gerhard t) :

N.O"H».H« + ((m»0)«0 - Cra»O.H.O + N.C«H».CHK).H.
neoflonine. Bcnsoicaa. Beoioie acid. Pheaylbensamlde.

hjdrid*.

2. By action of primaiy amines on chlorides of acid-radides (Q-e rhar dt) :

K.CH«.H« + C«HH).a « HCl + K.CH».C*H«OJI

MeUiyUmiii** Cblorid* of Methjlacetamida

acfltyl.

S. 3f action of primaiy amines on ethers :

N.C»H».H« + C*H»O.C»H*.0 « C^».H.O + N.O"H».0*HK).H.

EUqrlamine. Acetic «ther. Alcohol. EthyloeeUmtdc.

4b By action of monohasie adds on cyanio etheis (W arts) :

CHN.ILO + N.O«H».CO - CO.O + N.C*H».CHO.H.
Fonnlcadd. pranateof CarboDie EUi/l-fbrnuunMo.

ethyl. anhyd.

They are czystalline, and generally do not combine with acids ; boiled with adds
cr ilkalia, they take up HK), and regenerate their add and primaiy amine :

N.CTH».C«HK):H + HK) « N.O^».H« + C»H«0.H.O.

PheojiaeeUinide. Phcnylamina. Acetic acid.

ThcM containing cyanogen act as weak allcalis, forming with concentrated adds com-
poands vfaich are decomposed by water. B^ heat they are decompoeed in rather a
peealiar nfanner, yielding a tertuiy alkalanude, and a kind of intermediate dialkala-
mide, which oontaizis only monatomic radides :

8(lir.C«H».CSr.H) - N.(C«H»)«.CN + N«.C«H».(CN)«.H«
BOiylcyaaainido Dtothvlcyana* Ethyldlcyandianida.

mida.

Aoonrdine to G-erhardt (Ann. Ch. Phys. [3] liii. 307) secondary alkalamides are
acted Tip^by pentadiloride of phosphorus in the same way as primaiy and secondaiy
asiidcs:

N.cw.(7iPo.H + pa» - if(crH»nc«ff»)ci + poa» + na

PbtnyUbeiuaBiide* Chloride of pheoyl*

beiumnuyl.

2. Tertiary A iJkal amides. — They represent 1 molecule of ammonia in which all
the hjdrosen is replaced ; (a) by 1 basic and 2 add monatomic radides ; (6) by 2 basic
and 1 add monaftoniie radicles ; (e) by 1 basic monatomic, and 1 add diatomic radide.

0. Warereplaeed by 1 borne and 2 add monatovdo radioUs :

Ethyl-diacetamide K.C*H*.(C^K>)*

Fhenyl^^benjEandde . . , • . N.C'KCC'H'O)'

Thej are foamed : —

1. 3j action of chlorides of add^radides on seoondazy alkalamides (Gerhardt
aodChiosza):

N.OfH».CrrEPO.H + C»H»0.C1 - HCa + N.CFH»^C»HK))».
PiMBylbaiiaamidei Chloride of Fhanyldibeniamkla.

benioiyl.

% By ftefioii cf monobasic anhydrides on cyanic ethers (Wnrts):

(C«H»0)«.0 + N.C»H».CO - 00,0 + N,(?H».(C«H»0)«

Acetic anhy. Cyaoate of Ethyldiaoetamide*

drldau ethyl.

They sere neutral bodies, combining neither with adds nor with bases.

k B*ar9 TtpiMtd by 2 bade and 1 add monatomic tadieU:

Methyl-ethyl-cyanandde « , • . , N«CH".C'H*.CK

Diethyl-cyanamide N.(C<H*)'.GN.

The only membets of this group hitherto fonned, contain (^anc^n as the add-

ndide. liiey are formed by Uie action of chloride <k cyanogen on secondaiy amines

(Cahonrs and Cloes) :

N.O»H» C^».H + CN.a - HCl + KC«H»,(>H».CN.

BthylphcnylamtaM* Sthylpbenyk^a-

namlde.

They are Uqnid and TolatQe without decomposition. Heated with acids or alkalis,

N 2

180 AMIDES.

they regenerate a seeondRi7 amine and cjanic acid, which latter is farther decom-
posed into carbonic anhydride and ammonia :

N.(C«H»)«.CN + HHO - ]Sr.(C«H»)*H + CN.H.O.
Dlethyl-qrana- Dlethylamine. Cjaslc add.

mlde.

N.CO.H + H*0 - NH« + CO.O

CTinIc acid. 9

e. H* are replaced hy 1 monatomie baeie, and 1 diatonUo acid, radide, — Ab these
compounds correspond to those seoondaiy amides which are commonly called imidei
we will retain the same termination for them :

Phenyl-snocinimide (snccinanile) • • • • N.l>M\^C*H*0*)*
Ethyl-carbimide (cyanic ether) . « • « • N.G^'.^CO)"

With the exception of cyanic ethers, the only members of this gronp that have been
studied are those containing phenyl as their basic radicle; they are commonly called
anUee. They are obtained by the action of phenyLunine on dibasic anhydrides or
acids (probably also on the coiresponding chlorides) :

N.C«H».H« + C»H"0«.0 - H»0 + N.C«H».C'*BP«0«
Camphoric FheDylcamphorimide.

anhydride.

N.C«H».H« + CWH>«0«.H».0« « 2H«0 + lSr.C«H».C»«H»K)«.

Camphoric add.
Boiled with dilute ammoniai they form the ammomum-salt of an amie add :

N.O»H*.C*H«0« + NH*.H.O = N.H.C«H».C*H*0«.NH*.0

PhenyUttcciniinide. Phenylsaocinamate of

ammoDlum.

Fused with potash, they regenerate phenylamine and their add:

N.C*H».C«H*0« + K*H*0* « C*H*0«.B?.0 + N.C^» H«.

Succinate of
potastiunu

Afl cyanic acid may be regarded as carbimide, cyanic ethers may obTiooslj be
regarded as alkalimides. With potash they exhibit the same reaction as the foregoing

a,llra.MtTiiMAB *

N.C»H».CO + K*H«0« « CO.K».0» + n!C'H».H«.
By the action of water or ammonia, they form Bialkalamides (compound ureas):
N».(C«H*)«.(CO)» + H»0 « CO.O + N".CO.(C^»)«.H«.

S mol. cyapic ether. Diethylcarbamide.

N.OTP.CO + NH» - N*.CO.C*H».H«.

EtbylcarbamMc

n. BlalkaUunldM.

There are no primary dialkalamides : but there exists a dass of compounds occupy-
ing an intermediate place between primaiy and secondary dialkalamides. Thej re-
present 2 mols. of ammonia, in which 8 atoms of hydroffen are replaced, 2 by a diatomic
acid-radide, and 1 by a monatomic base-radide. With tbe exception of phenyl-ozamide^
N'.C^^GK)*.H^ the only members of this dass are the eompound urtae, representisg
urea or carbamide in which 1 H is replaced by a base-radide :

Ethyl-carbamide (ethyl-urea) .... N«.(CO)''.C«H».H»
Phenyl-carbamide (phenyl-urea) . . . • N«.(CO)''.C^*.H',

Tliey are formed by the action of a primary amine on cyanic add, or of ammonia on

cyanic ethers :

N.C«H»ja« + N.CO.H - N».CO.C«EP.H»
NH« + N.OO.C«H» « N«.CO.C"H».H»

Th^ are decomposed by potash, yielding carbonate^ a primary amine and ammonia:
N«.CO.C«H».H» + H«.K«.0« » OO.K«.0« + N.C^*.BP + NH».

2. Seeon dary Dialkalamides, — ^They represent 2 molecules of ammonia in which
4 atoms of hydrogen are replaced by 2 monatomic base-radides and 1 diatomic acid
radide:

Dimethyloxamide m(CH«)« (CK)«)''JP

Diphenylsucdnamide N*.(CW)*.(C«H<0*)..H*

Diethylcari)amide (diethyl-urea) .... N*.(C"H»)«.(COy.BP

ALEALAMIDES. 181

Thejr in finmed:

1. Bj beatiiig the nomial salts of oiganic alkalis r

C«0\N.CH»JEP)« - 2H*0 « N«.(CH»)«.0»0*,H«
OzAlato of nethy. DimethylozainJde.

1 3j aetion of primaiy amines on etlien of dibasic acids :

(K)».(C»H»)«.0» + N«.(CH«)*^* - (C^«.H».0» +m(CH«)«CK)«.H«.
Outato of ethyl. S moL methyU S mol. alcohol. Dimcthyloumide.

amioe.

3. By action of prinuuy amines on chlozideB of acid-radicles :

-sPAiyiPfjE^jEP + co.a* - ana + N«.(cm*)« co.h».

S BKH. phanylamiiio. Chloride Diphenylculninlde.

of cartHmyl.

The oompoimd meaa (alkal-carbamides) belonging to this group are also formed by
the aefcbacf water en cyanic ethers :

2(N.00.C^«) + HH) « CO.O + N«.(C«H*)».CO.H»
Cyanai« of DieChjlcarbamide.

ethyL

An tiiese seeondaiy dialkalamides are decomposed by potash, yielding a primazy
uuDc^ and the normal potassinm-salt of their acid:

N».(0«H«)».O»O«.H« + H«K»0» - K».(C*H»)«.H« + C«0».K«.0«

Dlethyloxaiiiide. S molt, ethyl- Ozali^

amine. potass.

Hofinann regards melanilinc^ C^EPIN* and a compoond, C*'H*^, which he has ob-
taioed by^e aetion of dichloride of carbon on phenjoamine, as cyan-diphenyldiamide,
1P.CN.(OT»)«JBP, and cyantriphenyldiamide, :^^.CN.(C•H»)^H^ respectively,—*, e, as
diilkahmides containing only monatomic radicles. Considering the reaction by which
the ktter at least of these oomponnds is formed, it may perhaps be preferable to regard
it as deriving fiom 8 molecoles of ammonia, in which a portion of the hydrogen is
icplaced by the tetratomic radicle, CT ra. ae N«.C.(C«H»)«.H«.

Pebil has described the following compounds, intermediate between aeoondaiy and
tertiaiy dialkalamides :

Diphenyldtrimide N«.(C-H»)«.(C*H»0*r.H:

Diphenylaconitimide N».(C^»)«.(C>H»0»r.H.

They oorreqpond to the monadd phenylinm-salts of tribasic acids, less the elements
ofSatomaofwater:

8. Tertiary Dnalkalamides. — They represent 2 molecoles of ammonia in which
all the hydrogen is replaced by base- and acid-radicles, one of which at least mnst be
polyatomic. This process is represented by componnd-nreaa, in which all the hydro-
Ken is replaced by baaic radides, — «.^. Tetrethylcarbamide or tetrethyl-nrea,
1^.(C0)*'.(J^B[')^ iysobyBnflfssnlphocyamde of ethylene (ethvlene-disnlphocarbamide)
N'.(GS)'.(C^*)*. obtained by boiling chloride of etnylene witii an alcoholic solution of
snlphocfanate of potassium (Proc. Soy. Soc. viiL 188), and by Hofmann's diphenyl-
eaitoxamide, K».rCO)''.(0K)«XC«H»)*', obtained by the action of dilute hydrochloric
add on dicyanmeianiline.

CP'H^'N* + 3HC1 + 3H«0 - 3NH*C1 + N».CO.CK>«.(C*H»)«

More nkht probablT be obtained by the action of seoondazy amines on chlorides of
tod radides, or on ewers of dibasic adds :

2(N.(CH>)«.H) + C*H*0«.a* - 2Ha + N*.(CH»)^C<H*0«.

TetramethjUnoci-

2[NX0«H»)«jq + C<H*0« (C«H«)«.0* - 2(0«H»JLO) + N».(C*H»)*.C*H«0«

Soodnate ofetDyL Tetrethykuodnamlde.

1. Secondary Trialkal amides, — They correspond to 3 molecules of ammonia, in
vhieh 6 atoms of hjdrq|;en are replaced by 1 triatomic add-radide and 8 monatomic
b8ae.radides. Examples are Pebel's triphenyldtramide^ K'.(Cna*)*.(C^*0«)'*'.H', ob-
tained by the aetion m dtric add on phenylamine :

O^BPO*.H».0» + 8(N.C^.H«) - N».(C«B[»)«.(?H»0*.H» + 3H«0.

It eonesponds to the normal dtrate of phenylium, less the dements of 8 atoms of
vater. Also SchifTs triphenylphoephamide, N'.(CH»)'.PO.H', and trinaphtylphos-

N 3

182 AMMONIA.

phamide^ N'.(C'*H')'.PO.H*, obtained by the aetion of pbenylamine and naphtjlamine
respectiTelj on ozychloride of phofphonia (Ann. Ch. Pnann. eL 800) :

POa« + 3(N.Cra*.H«) - N».(C»H»)«J>aH«. + 8Ha

2. Tertiary Trialkalamides, — ^The c^annric ethen may be placed in this diii-

Bion, e, g, cyannrate of etl^yl, N«.(60)»,(C*H»)».— F. T. C.

and ASKOKWMJJKM^ See Ctavttbahic AjCIIM.

EXOUnn. A red earthy mass from Chile, containing 86*5 antimony, 14*8
tellurium, 12'2 copper, 32*2 mercnry, and 2'ff qnarti, besidsB oscygen; pvobtUy a
mixture. (Bammeubtrg^t Mintralchemifi, p. 426.)

AIIMOVXJL. NH*. (S^nymes, VolaiiU MaU, MkMu mr, Ammomaeal goi,
Jmnumiajuet Ammoniak.)

S^MtoTf, — The eariiesi mention of aqoeoos amwMwii% whioh was known long befen
the gas itself^ is made by Raymond Lully, in the thirteenth oenturf : he prepared it
from urine, and called it MtreuHut vd tpiritus ammaUt. Basil Valentine, in the
fifteenth century, first pr^ared it from sal-anmioniac : he still retained the name spiritut
urina. It was Bergman (1782) who first designated it bj^ the name ammonia, Am-
moniacal gas was disooyered by Priestley, who describes it in 1774 by tho name of
alkaline air ; he also observed its decomposition by the electric spariu 8<abeele» in 1777.
ascertained that it contained nitrogen, regarding it as a compound of nitiiigen and
phlogiston. Its true oomporition was first ascertained by BerthoUet ^1785) ; and it
was finally aneJysed with still greater exactness, by his son Am. BertnoUet in ISOflw

Katural Souroet, — Ammonia exists in the air as carbonate of ammoniwn : in rain-
water, oBperially in that of thunder-showers, as nitrate. In sea-water, and in many
mineral springs. In most kinds of clay and soils: in seequioxide of iron, and in the
nugority of iron-ores. Sal-ammoniac and ammonium-alum are found as minerals, the
former chiefly in Tolcanic regions, and in some specimens of rock-salt. Ab amiiMmiacal-
salts, in animal fluids and excronents (especially in nrine), and in the juices of many
plants.

Fi>rmaii(m, — Ammonia cannot be formed by the direct combination of its elements
in the free state. When 1 toL nitrogen and 3 vols, hydrogen are passed throng^ a
red-hot tube, no ammonia is formed, not eren if spongy platinum be present. But it
is formed with sreat readiness by the combination of its elements, wnen one or both
of them is in uie naeeent state : tL f. at the moment of its Ubeiation from another
compound : and in this manner ammonia may be formed from many snbstancesi dganie
and inorganic.

1. FrSm inorganic wbeianeei. — On igniting a mixture of oxygen, nitrogen, and
excess of hydrogen, nitrate of ammonium is formed. (Th. Saussure.)

a. Formation from nascent hydrogen and free nitrogen, — Water containing at-
mospheric air yields nitric acid at the positive pole, and ammonia at the negative pole
of a voltaic battery (Sir H. Davy). Moistened iron-filings, in contact with atmo-
spheric air or nitrogen at the ordinaiy temperature, induce the formation of ammonia
(Ghevallier, Berzelius). (Will states that no ammonia is thus formed.) This
reaction accounts for the existence of ammonia in rust of iron, and iron ores generally.
When liver of sulphur ia fused with an e^ual weight of iron-filings, and water dropped
on the hot mass, ammonia is evolved (Hollunder). When oertain metals wluch
combine readily with oxygen (potassium, arsenic, lead, iron. &c.) are heated with the
hydrates of potassium, SMium, barium, or calcium, in contact with air, ammonia is
formed. Faraday states that this formation of ammonia takes place even in an atmo-
sphere of hydrogen : a fact explained by Bischof as arising from the difllcnlty of
obtaining hydrogen free ftom atmospheric air. Beiset also points out that the hydrogen
will contain nitric oxide, if the sulphuric acid employed for its generation contains
nitric acid or nitric oxideu

b. Formation from nasomt nitrogen and free hydrogen. — A mixture of 2 vols, nitric
oxide and 6 vols, hydrogen passed over gently heated qwngy platinum, yields ammonia
and water (Hare; Ville, Ann. Ch. Phya. [3] xlvi) The same gases when passed
through a red-hot tube, only yield ammonia when some porous substance is present;

Eumioe-stone, or feme oxide acts most energetically (Keiset). Nitrous oxide and
ydrosen in excess yield ammonia when in contact with hot spongy pUtinum or plati-
num-mack. Hydrogen saturated with nitric acid vapour acts in a similar manner.

c ForTfuUion from nascent hydrogen and nascent nitrogen, — Moist nitric oxide
passed over heated iron-filings yields ammonia. A mixture of nitric oxide and hydro-
sulphuric acid, passed over heated soda-lime, yields ammonia (Ville^. Certain
metals which decompose water at a high temperaturo (iron, zinc, &c.), wnen treated
with dilute nitric acid, or the acjueouB solutions of certain nitrates, vidd ammonia.
Ammonia is formed when nitric acid is added to one and sulphuric add in a hydrogen

AMMONIA. 183

maxaim^ alio liy tlie deeompodtioii of chloride, iodide, and phoBpliide of nitrogen,
and of all bodies beknigin^ to the elaas, amides, by water. When a mixture of baryta
and earbonaeeooa matter u heated in contact with air, cjanide of barium is formed, a
eaa^KHUid which is deoompoaed by steam at ^00° G. into carbonate of barium and
amaonia: Maigneritte and Sonideyal have lately proposed to employ this process for
thepmaration of ammonia on the laige scale. (Bep. Chun. App. li 170.)

2. From aryanic mib$Umcu. — Many mm^nitrogemma organic bodies form ammonia
by nolongcd contact with air and water : «.^. in the process of putresCaction. Sugar,
OTaiaf<p«, taitmtes, && yield ammonia when heated with alkaline or alkaline-earthj
hydrates, in contact with air. Oxygen-compounds of nitrogen, heated with organic
Hsdnring agents, &^. nitric oxide with aloohol-yapour, nitric acid with gum, form
swmfwiTa Most ntiroffemsed organic compounds ^eld ammonia, either ^e or com-
bined, in tlie processes of potrefustion or of diydisttUatibn : it is from this source tiiat
the ammonia eodsting in nature is chiefly deriyed.

Preparation, — ^Powdered sal-ammoniac is mixed with twice its weight of slaked lime,
the miztnre ooyared with a layer of coarsely powdered quick lime, about equal in weight
to tlie sal-ammomac used, and the whole heated gradually in a flask or retort : for the
preparstioii of ammonia on a large scale, iron yessels are used. The gas is passed
throo^ a two-necked bottle, in which aqueous yapour is condensed, and any solid
paitiHea that may be earned oyer azeanested ; it is then dried by passing oyer solid
potash or qvi^ lime — or better, a mixture of the anhydrous oxides of potassium and
oqi^wk; obtained by heating nitrate of potassium with finely diyided copper reduced
fimm the oxide by hydrogen (S t as), (chloride of calcium absorbs the gas)— ^d collected
over meremy. If the gas is ^ure, it should be entirely absorbed by water. In order
to obtain perfectly diy ammoma, Vogel recommends saturating a concentrated aqueous
solalion of ammonia with solid chloride of calrium, heating gently, and passing the
gaa orer solid potash.

Ih'cpe9iie$. — Colourless gas, of a pungent smell, and strong alkaline taste. Its
^wofie gravity is (calculated) 0*5893; (H.Dayy) 0*6901; (Thomson) 0*5931; (Biot
and Arago) 0*5967. 1 litre at 0^ C. and 760min. barometric pressure weighs 0*7752
grm. (Biot and Arago). Its specific heat (water a 1) is 0*508 (Kegnault). Its
le&actaTe power (air a 1) is 1*309 (Dulong).

It does not support either combustion or respimtion : animals die when immersed
in it. It is feebly combustible : when issuing m a thin stream into atmospheric air,
it may be kindled, and bums with a pale fliune. It colours turmeric paper brown,
and reddened litmus blue : the colours disappear on exposure to the air.

It may be condensed by cold and pressure, and obtained both in the liquid and solid
fann. Faraday prepares liquid ammonia as follows : Ammonio-chloriae of silver is
introduced into a very strong glass tube, closed at one end, which is then bent at an
aeate ang^e^ the chloride being in the loncer Hmb. The shorter limb is then sealed
and immersed in ice, and the chloride gradually heated : it fuses at 38^ C, and be-
tween 112^ and 119^ C. gives off all its ammonia, which condenses to a liquid by its
own pfesBOze in the cool part of the tube. As the chloride of silver cools, the liquid
ammfliiM. boils yiolentlv, and is reabsorbed by the chloride. Gnyton de Morveau and
Bunsen have condensed ammonia without pressure by a mixture of chloride of calcium
and ice, the fonner at ~ 52^ C, the latter at — 40^. Liquid ammonia is a colourless, very
mobile liquid, refracting light more powerfully than water; specific gravity 0*76:
boiling-point at 749min. braometic pressure, — 33*7^ C. (Bunsen.) Its tension at
-17-78^ C. a 2*48 atmospheres: at 0° C. » 4*44 atm. : at 10-8^ C. » 6 atm.: at
I9-44<' C. a 7-60 atm. : at 28*31° C. » 10 atm.

Faraday has obtained solid ammonia by exposing the dry ^ to a pressure of 20
atmoi^iheres and to a cold of — 75° C, produced by solid carbomc anhydride and ether.
It is a white, transparent, crystalline body, which melts at —75° C, and has a higher
specific gravity than liquid ammonia.

DoeomooUiono. — I)iy ammonia is decomposed by a succession of electric sparks :
the resoiting gas is double the volume of the original gas, and consists of 1 vol. nitrogen
and 3 vDlsTnydrogen. Also by being passed tlm)ugh a red-hot porcelain tube contain-
ing eopper or iron wire ; gold-, silver-, or platinum-wire acts similarly, but less ener-
geticafiy. No change is produced in the gold and platinum-wire : the copper and iron
wii« are rendered brittle, and sometimes increased in weight, owing to the formation
of a nitride. — 2 vols, ammonia mixed with not less than 1, nor more than 6 vols.
oxygen, are exploded by the electric spark : the products, if the oxygen be in excess,
are water and nitrate of ammonium ; if the ammonia be in excess, water, nitrogen,
and hydrogen. — Aqueous ammonia, in contact with finely divided copper or platinum,
and oxjffftm, cft atmoopherie air, is converted into nitrite of ammonium, both its con-
stitaeBts imdeigoing oxidation (Handwb.) — ^Ammonia is decomposed by several of the
ooygen-eompoiinds of chlorine and nitrogen. Dry ammonia mixed with dry hj/po^

N 4

184 AMMONIA.

cklorctu anhydride explodes yiolently at the ordinaiT' temperature, -with sepantioo of
chlorine. Aqueous ammonia added gradually to aqueous hypochhrmu aeid^ the
mixture being kept cool, yields nitrogen, and chloride of nitrogen. Ammonia nuzed
with proper proportions of nitroua or nitric oxide, explodes by the electric spark, yield'
ing water and nitrogen. Ammonia is Tiolently decomposed at the ordinaiy temperatme
by peroxide of nitrogen^ whether liquid or gaseous, with evolution of nitric oxide and
nitrogen (Dulong). — In contact with chlorine in tiie cold, ammonia bums with a red
and white flame, forming chloride of ammonium and free nitrogen (4NH* + C9,' ^
3NHK)1 4- N); when chlorine is passed into strong aqueous ammonia or a solution of an
ammoniacal-salt» chloride of nitrogen is also formed. — Iodine does not deoompoee
diy ammonia: in presence of water, iodide of ammonium. and an iodine-denT^
tive of ammonia are formed. — ^With bromine^ ammonia yields bromide of ammo-
nium and free nitrogen. — ^Passed with vapour of phosphorius through a red-hot tube,
ammonia yields phosphide of hydn^n and free nitrogen. — ^Passed over red-hot char-
coal', ammonia yields cyanide of ammonium and free hydrogen. — ^With bistUphide of
carbon, ammonia gives hydrosulphuric and sulphocyanic acidb (NH' + CS* i- B^ +
CSH). — ^When potassium or sodium is heated in dry ammonia, hydrogen is evolved,
its place being supplied by the metal, and nitride of potassium and hydrogen (potusap
mine), NKH', is formed. — In contact with zinc-ethyl, ammonia gives zinc-amine KZnH'
and hydride of ethyl, C^*. Mainy metaUie oxides decompose ammonia with the aid of
heat : the products are sometimes water, nitrogen, reduced metal, and more or less of
an oxygen-compound of nitrogen ; sometimes, water and a metallic nitride. — ^Ammonia
reacts with anhydrous acids, chlorides of acid-radides, and many compound ethers,
giving amic ados, or amides. In like manner, it gives with many derivatives of the
alcohols, amic bases or amines. (See Aiao Acids, Amc Basbs, Ajcdbs, Amikbs.)

We have seen that ammonia is decomposed by certain metals and metallic oxides,
hydrogen being liberated, and compounds formed representing ammonia in which a
part or the whole of the hydrogen is replaced by a metaL There are certain organic
compounds {e. g. monobasic anhydrides, compound ethers, &&) which are capable of
decomposing ammonia in a similar manner, with formation of compounds representing
ammonia in which the hydrogen is wholly or partially replaced by an orsanic radide,
acid or basic. The numerous and interesting class of compounds which are thus
formed frY>m ammonia by the partial or total replacement of its hydrogen by other
radicles, oreanic or inorganic, acid or basic, is known by the generic name of amides:
under which name they ore fiilly described.

Combinations. — 1. With Water {Solution of ammonia. Aqueous ammonia^ or
simply Ammonia, Spirits of hartshorn, Salmiakgeist, Liquor ammonii).

Both water and ice absorb ammonia with great avidi^, with considerable evolution
of heat, and with great expansion. Davy found that 1 vol. water at 10° C. and 29*8
inches barometric pressure absorbs 670 vols, ammonia, or nearly half its weight : the
specific gravity of this solution is 0*875. According to Dalton, water at a lower tern*
perature absorbs even more ammonia, and the specific gravity of the solution is 0*85.
According to Osann, 100 pts. water at 249 C. absorb 8*41 pts. at 66^ C. 5*96 pts. am-
monia. 1 voL water by absorbing 505 vols, ammonia, forms a solution occupring
1*5 vols., and having specific gravity 0*9 : this, when mixed with an equal bulk of
water, yields a liquid of specie gravity 0*9455 : whence it appears that aqueous
Ammonia expands on dilution. (Tire.)

Preparation. — 1 part of sal-ammoniac in lumps is introduced into a glass flask,
with 1} parts slaked lime, and from 1 to 1| parts water : and the flask is connected
by bent tubes with three Woulfe*s bottles. The first bottle, which is intended to
arrest any solid particles that may be carried over mechanically, and any empyrea-
matic oil contained in the sal-ammoniac, as well as to condense aqueous vapour, con-
tains a small quantity of water (Mohr prefers milk of lime). The second bottle con-
tains the water to be saturated with ammonia: it should contain a quantity of water
about equal in weight to the sal-ammoniac employed, and should not be more than
three parts full, to allow for the expansion. These two bottles should be placed in cold
water, and each provided with a safety tube. The third bottle contains a little water,
to retain any ammonia that may pass through the second bottle. The fiask is then
heated in a sand-bath, care being taken that its contents do not boil over : and the
operation continued till about half the water in the flask has distilled over into the first
bottle. The first bottle then contains a weak and impure solution of ammonia : the
second a pure and strong solution (if a perfectly saturated solution be required, the
quantity of water in this bottle should not exceed } the weight of the sal-ammoniac
employed) : the solution in the third bottle is weak, but pure.

The proportions of lime and water to be added to tlie sitil-ammoniac in order to pro-
duce the largest yield of ammonia have been variously stated : those given above are

AMMONIA.

185

WW most genenillj TfHxired. Accoidmg to the eqnatioxi, CaHO + NH*C1 » NH* +
CftO + HK), the amount of slaked lime should be to that of sal-ammoniac as
37 : 5Z'5, or 69 parts of the former to 100 parts of the latter. But in practice it is
alwmjs focmd necessarj to employ a larger proportion of lime ; for not only is the lime
of eommeice always impure, but also it is impossible to bring the whole of it into such
eontact with the sal-anmioniae, as would ensure the completeness of their reaction.
Hm object of adding water is to ensure the gradual solution of the sal-ammoniac, and
eooeequently its more complete contact with the lime. There are also other disad-
TBotagefl which attend the absence of water. If the lime and sal-ammoniac are mixed
io a state of powder, a large quantity of ammonia is lost before the mixture is intro-
duced into the flask ; and the heated mass expands on cooling so as invariably to
break the flask. These inconyeniences are avoided by first placing the sal-ammoniac
in lumps in the flask, and then oorering it with the powdered Hme : but in this case
the heat required is sufficient to TolatiUse the sal-ammoniac, which is liable to stop
up the deliveiT-tube and canse a dangerous explosion. Moreover a larger quantity
of empyreumatic oil passes over with the ammonia : and the chloride of calcium formed
in the flask obstinately retains a portion of the ammonia, which is consequently lost.
On the other hand, the addition of too much water diminishes the product of am-
monia, and hampers the operation in other ways.

In the preparation of aqueous ammonia on a large scale, the gas is generated in
cut-iron or copper vessels : earthenware vessels are generally fouad not to answer,
owing to the porosity of their structure.

The aqueous ammonia thus prepared may contain the following impurities, which
ue easily detected :

Carbcmate o/anuniOmum. — Oecnrs when the lime employed contains much carbonate,
or when the solutioa has been exposed to the air. Causes turbidity when heated with
chloride of barium.

Cilorme. — Owin^g to chloride of ammonium having been sublimed, or carried over
mechanically. The solution, saturated with nitric acid, gives a cloudiness with nitrate
of sihrec

Lime. — Gamed over mechanically. CKves a precipitate with oxalic add : left as a
•olid Rsidne on evaporation.

Copper at Lead. — ^Derived from the generating vessel. The former is detected by the
ioktion becoming tinged with blue on evaporation ; the latter by hydrosulphuric acid.

Empyrmmatio oil, — From the sal-ammoniac. The solution has a yellow colour
and a pecoliar smell.

FnpeirHeB. — Aqueous ammonia is a colourless transparent liquid, smelling of
KinmAnU^ and having a sharp burning, urinous taste. Its specific gravity varies from
1*000 to 0'8o, according to the amount of ammonia it contains: its boiling-point varies
similarly (see D a 1 1 o n ' s table, ir^ra.) A perfectly saturated solution freezes between
—38^ and —41^ C, forming shining flexible needles: at —49^ C. it solidifies to a
grey geUtinous mass, almost without smell (Fourcroy and Yauquelin). It loses
afanort an its anunonia at a temperature below 100^ C. The following tables have
been constructed, showing the amount of real ammonia contained in aqueous ammonia
of difierent densities :

Dal-tom.

H. Davt.

Uri.

S^edflc

Pcremtacs

Boiling

Specific

Percentage

Specl6c

Percentage

Specific

Percentage

fnrttjr.

AniiBOouu

Point.

grtiTii7.

Ammonia.

gravity.

Ammonia.

gravity.

Ammonia.

OH}

3S-8

-4«

0^50

82-8«

0-8914

97-940

0-9868

15-900

e«

3S6

+3-5«

0-8857

99-25

0*8937

27-688

0-9410

14-575

IW7

»9

ltf»

0-9000

se>oo

0-8967

37-038

0*9455

18*350

17-t

ir>

0*9054

25-37«

0-8983

26-751

0-9510

11-985

•-»

94*7

sa»

0*9166

93 07

0-9000

96-500

0-9564

10-600

SS-S

0-9255

19 54

09045

25-175

0-9614

9 275

»9I

19*8

8r»

0-9826

17-52

0*9090

93-850

0-9662

7*950

17'4

44«

0-93I85

15*88

0-9138

29-525

0-9716

6-625

»«

lfr-1

ifp

0*9485

14*53

0-9177

21-200

0-9768

5-500

»M

19-8

47°

0-9476

18*46

0-9227

19-875

0-9828

3-975

Mft

10-5

esp

0*9518

19-40

0-9275

18-550

0-9887

3-650

»S6

8-a

0-9545

11-56

0-9320

17*225

0 9945

1-338

»S

79"

0-9578

10-82

o«

4-1

0-9S97

10-17

0«

980

0-9616
0-9699

9-60
9 50*

•Tl

lesenimiben

weredetf

tnnined by

experiment :

the rest in

Davy's table

by calculat

lou.

186

AMMONIA.

J. Orra DetenniiLations made at 16^ C.

Spedfle

p0reeDta«
AmmoDik.

Specific

PeroenUffe

Specific

PercoiUge

gravtt/.

gnwltj.

AmmooU.

graTicjr.

AflUBooia.

0*9617

12K)00

0-9607

9-035

09697

7-9M

0-9fi31

11-876

0-9613

9-600

0-9703

7-135

cwas

11-780

0W16

9-376

0-9707

7-000

0-9631

ires5

0-9631

0-860

0*9711

6-876

0*9696

11-500

0-96BI6

9-135

0-9716

e750

0-9640

11-375

0-9631

9<XI0

OiTTtl

6'636

0-9645

1I-980

O-OfOO

8-875

0-9736

6500

09660

11-195

0-9641

8-750

0-9730

e«i

0^666

11-000

0-9646

8-635

0-9735

6-850

0-9S66

10-960

0-9660

8-600

0-9740

0-185

00669

10875

0-9664

8-376

Oi»745

6100

0-9664

10760

0-96!»

8-380

0-9749

6-875

0-9609

10-0S5

0-9664

8-196

0^64

5-750

0-9674

10-600

0-9669

8-000

0-9760

5-636

01M78

10-375

0-9673

7-875

0-9764

6-600

0-9MS

10-350

0-9678

7-760

Oi)768

5-876

0^9588

10-1S6

0-9683

7-685

0-9773

5-360

0-9693

10-000

0-9688

7-500

0-9n8

6136

0-9697

9-876

0-9693

7-375

00783

tixn

O-960I

9-760

Ifc Cajuus. (Ann. Gh. Phaim. xciz. 164.) DetenninatioDfB made at 14^ 0.

Specific

P.C.

Spedflo

P.C.

Spedfle

P.C.

Spedfle

P.C.

Spedfle

P.C.

Spedfle

p.a

gravity.

Amm.

gravity.

Amm.

gravity.

Amm.

gravity.

Amm.

gravity.

Awn.

0-8M4

86-0

0-8976

80-0

0i)133

34-0

0-9814

18-0

0^630

I8i)

09749

0-8848

86-8

0-H981

89-8

0-9139

33-8

0-9321

17-8

Oi»637

11-8

0-97A7

6-8

0-8863

36-6

08986

99-6

0-9146

33-6

0^037

17-6

0-9684

11-6

0^66

6-6

0-8866

35-4

0-8991

89-4

0-9150

83'4

0-9833

17 4

0-9648

11-4

0i»73

5-4

0-8860

353

0-8996

99-8

0*9166

332

0-9940

17-3

0^649

ll-S

09781

6-2

0-8864

36-0

0-9001

89-0

0-9163

83-0

0-9347

17-0

0^566

11-0

O9990

08068

34-8

0-9006

88-8

0-9168

22-8

0-9368

16-8

0-9663

10-8

fr9999

0-8873

346

0-9011

28-6

0-9174

22-6

0-9360

16-6

0-9571

10^

0^807

0-8877

34-4

0-9016

88-4

0-9180

8-2-4

0-9366

16*4

0-9578

10-4

0-9815

4-4

0-8881

34-3

0-9081

38*3

0-9186

22*3

0*9373

16-9

0-9686

109

0-9883

0-8886

340

0-9086

88-0

0^191

33-0

0-9380

16-0

0-9998

10-0

09831

0-8889

33-8

0*9031

37*8

0-9197

31-8

0-9386

168

0-9601

9-8

0-9839

0-8894

836

0-9036

37-6

0-9303

81-6

0-9393

16-6

09606

9*6

0^847

O-O'tOe

33-4

0-9041

37*4

0i»09

91-4

0-9400

16-4

0-9616

9-4

0-9866

3-4

0-89«

38-3

0-9047

973

0-9316

81-3

0*9407

16-8

0-9633

9-3

0-9863

»8

0-8907

33-0

0-9068

27-0

0-9281

81 0

0-9414

16-0

0-9681

9-0

0-9373

0-8911

3S«

0*9087

36-8

0*9287

30*8

0-9430

14-8

0-9639

8*8

09883

0-8916

83-6

0-9068

86«

09883

30-6

0*9427

14-6

0-9647

01890

0-8930

83*4

0*9068

36-4

0-9239

204

0-9434

14-4

0-9664

8-4

0-9(199

3-4

0-89-i6

833

^9073

86-3

0*9346

30-8

0-9441

14-8

0^668

8-2

0*9907

0-8999

88 0

0-9078

86-0

0-9261

30-0

0-9449

14-0

0*9670

8-0

0^15

0-8884

31-8

0-9083

36*8

0«67

19*9

0-9466

13*8

0-9677

7-8

05984

0-8988

31-6

0-9089

36*6

0-9964

196

0-9463

13-6

0-9685

7-6

05932

08943

31-4

0-9094

26-4

0-9371

19*4

0-9470

13-4

0-9* 93

7-4

05941

1-4

0*8948

81-3

0-9100

86-3

09277

19-2

0-9477

13*3

0-97UI

7-3

05950

1-8

0-8963

810

0-9106

36*0

0-92KS

190

09484

18-0

0-9709

05959

0-8967

30-8

0*9111

34-8

1 0-9889

16-8

09491

138

0-9717

6-8

05967

•5

a8963

30-6

0-9116

34-6

1 0^296

18-6

0-9498

18-6

0-9736

0-6

05976

0-8967

30-4

0-9183

84*4

0-930-i

18-4

0 9605

18-4

0-9733

6-4

05968

(^4

0-8971

30-8

0-9187

84-8

, 0-9308

18*2

0-9612

12-2

0*9741

6-3

05991

By the aid of these tables, the strength of aqueous ammonia, like that of commeraal
aleohol, may be approximately ascertained hv taking its specific gravity. (See also
Qriflin's Table given in Ure^s Dictionary ojArts, ManufaciureSf and Mines^ vdL i.
p. 132, and Chem. Soc. Qn. J. iii. 260.)

Boscoe and Bittmar (Chem. Soc. Qu. J. idi. 147), have detenninedtheamonntof
ammonia-^ absorbed by water at yarions pressures and temperatures. The results
are given in the two following tables.

Table A shows the weight of ammonia-gas in granmies G absorbed by 1 gramme
of water at 0^ C. and various jpar^to/ pressures P.*

* By partial presfure It meant the total preature under which the absorption oocurt,
of aqueona vigour at 0° C

the

AMMONIA.

187

Table A

IHM

0*tt

0*466

086

0-9S7

1*46

1*49

0«1

INM4

0'61i

000

0-963

1-ao

1-SM

»«M

0-35

0-661

1001

1*66

1-664

0<B

0>M0

O-W

0-607

1-00

1037

1-60

1-646

0-I4S

0«46

1-06

r075

1-66

1-707

• »

0-176

0*50

O^BO

1-H7

1-70

1-770

••T*

o^ns

0-56

0*731

1-16

1-161

1-76

1-836

O-lOO

O^ft

aeo

O-TW

1*30

1-903

130

1*906

t^m

04l»

0«

0-W4

1-36

1-363

1-36

1-076

0-l«

0-SSI

0-70

0-840

1*30

1-810

1-M

SHM6

o-m

0*381

0-76

0-379

1-36

l*30t

1*96

- 3-130

tPSOO

0-411

O906

1-40

1-416

IHW

3-196

Fiom these nnmben it appears : (1) that the quantity of ammonia absorbed by
vitcr at 0^ G. is fiff from beuff proportional to the pressure ; and (2) that for equal
iaoements of pressiue np to about 1 metre of mercmy, the corresponding increments
of absorbed ammonia continnaHy diminish, but that above this poin^the amount of
disiohred gas inocases in a more rapid ratio than the pressure.

Table B ahowB the weight in grammes of ammonia (column IL), absorbed by
1 giamme of water under the pressure of 0*76". and at yarious temperatures (oohimn I).

Tabu R

1 ■•

11.

/ opa

0«76

le^c.

0-668

»2*»C.

0-889

48°a

0-944

/ **

0«8S

18»

0-654

340

0969

60°

0-999

1 *•

1^798

80«»

0-696

36°

0-343

69°

0-214

«•

0761

88«»

0-499

38°

0-394

64°

0-900

8P»

V7\t

24*

0-474

40°
49°

0-807

66°

(M86

1€^

0^79

86»

0-449

0-eM

l«»

0646

88"

0-486

44«

0-975

I4f»

0^618

30«

0-403

46°

0-969

A^ufloas ammonia possesses the property of dissolying many salts which are insoluble
wrmter. Thus it diasolTeB chromic and stannic oxides, the protoxides of tin, cadmium,
4tcL, the oxides of copper and silrer. The compounds thus formed are decomposed
^rj- beat, loau^ ammonia, sometimes with explosive violence. Many other salts are
almo flolnhie in aqueous ammonia, e.ff. phosphate, chloride, bromide of silver, &cl : in
the original salt can be recovered unchanged by evaporating off the awimnTiia ;
intimate combination is effected.

2. With alcokol. (liquor ammoniaci alcoholicus).

Alcohol, like water, absorbs ammonia in great quantity, with eonsiderable expansion

and evolntion of heaL The aleohoUe solution is prepared in precisely the same way as

the aqoeons solution, akohol of B6 — 90 p. c being substitntra for water in the second

Vko^tle. The proportion of alcohol to the sal-ammoniac employed should be somewhat

less than in the ease of water. The specific gravity of the solution of course varies

with the amount of alcohol and ammonia whid^ it contains.

5. WUk metallie wUs. Ammonia forms solid compounds with oortain metallic
ondes (of gold, silver, platinum, mercury, antimony, &c) which are decomposed l^ heat,
freqnenUy with explosive violence. Cortain metidlic chlorides, bromides, and iodides
(pi ailrer, nJrium, ^) absorb ainmonia, frequently with evolution of heat Some of
these oompoonds lose their ammonia when exposed to the air ; others, but not all, when
heated. Some dissolve in water without decomposition, forming solutions from which
the whole of the ainmonia is not precipitated b^ dichloride of pktinum : the nugority
are decon^KMed by water, which sometimes dissolves the orifi;inal salt and separates
ammonia, sometimes precipitates the metal as hydrate. Simuarly, certain crystalline
•atts, when freed from their water of crrstallisation, absorb ammonia abundantly and
in atomic proportion, forming compounds which are decomposed hy heat or by water.
/imwwwiiA also combines with metallic cyanides, with fluoride of silicon, and other bodies.

4. Witi acidff forming ammomacal salts, (See Akmoniacal Salts.)

6. WUk fU^fitanc Ofu^drides, forming the ammonium-salts of amic adds. (See
Ave Acoml) F. T. C.

188 AMMONIACAL SALTS.

Ammonium-^altSf Sels ammoniacauXf Ammoniah'

salze.

Ammonia combines veiy readily with acids, which it neutntliseB completely, formiiig
definite crystalline salts, known by the name of ammoniacal or ammonimn-ealts.
These salts are isomorphons with those of potassinm, and are in their genefral properties
so closely analogous to metallic salts, that they are nniversally regarded as bdonsiiig
to this class of bodies. There is, however, a characteristic difference in tibeir mocteof
formation. While other metallio salts are formed by the substitiition of a metal tar
the hydrogen of an add, e,ff» chloride of zinc, ZnCl = HCl + Zn — H : ammoniacal
salts are formed by the direct combination of ammonia with the add, without elimi-
nation of hydrogen, — e.g. chloride of ammoninm, NHK))1 « NH' + HGL

Among the various theories by which it has been proposed to represent the oonsti-
tntion of these salts, that which most dearly m>resses their analogy with other
metallic salts is unquestionably the Ammonium Theory of BeizeUus. According to
this theory, ammoniacal salts contain a compound metaJ, ammomum^ NH\ analogous
to potassium, sodium, and other metals, the salts of which, ammoniumrsdlU, are
analogous to other metallic salts. Thus, chloride of ammonium, CINH^, is analogous
to chloride of potassium, CIK ; sulphate of ammonium, SO\NH*)*, to sulphate of
potassium, SO*K', &c This hypothetical metal has never been isolated. An amal-
gam of mercury and ammonium is, however, known to exist, which affords strong
corroborative evidence, not only of the existence of ammonium, but also of its metallic
nature, metals bdng the only bodies which are capable of forming amalgams with
mercury. This singular substance, discovered simultaneously in 1808, by Seebeck, at
Jena, and by Berzehus and Pontin, at Stockholm, was originally prepared by Hie action
of dectricity upon aqueous ammonia in contact with mercury. A strong solution of
aqueous ammonia in which mercury is placed, is brought into the voltaic cirde, the
negative pole dipping into the mercuiy, and the positive pole into the liquid. An-
other method is to cup the negative wire into mercury, wnich is placed in a cavity
hollowed out of a fra^ent of a solid ammoniumHsalt, carbonate, sulphate, phosphate,
or chloride, the positive wire being inserted into the salt itself, or connected with a
metallic plate on which the salt r^ts. Oxygen, or, if chloride of ammonium be em-
ployed, chlorine, is evolved at the positive pole, but scarcdy any gas at the negatiTe
pole ; while the mercury increases very largdy in volume, and assumes the consistence
of butter. When completdy saturated with ammonium, the amalgam is lighter than
water : obtained by the former method, it has frequently a ciystfSline structure It
is a very unstable compoxmd, decomposing spontaneously as soon as it is removed from
the voltoic circle, being resolved into liquid mercury, and a mixture of 2 vols, am-
monia, NH*, and 1 vol. hydrogen, H. When cooled bdow 0° C, it solidifies and crys-
tallises in cubes. At a very low temperature, it contracts, and becomes brittle;
decomposition does not begin till the temperature rises to 29^ C. According to Sir H.
Davy, it contains 1 atom NH^ to 753 atoms mercuiy. The amalgam may also be
prepared without the intervention of electridty, by bringing potassium- or sodinm-
amalgam — the latter is more energetic in its action — ^into contact with an anmioninm-
salt, either solid and moistened with water, or as a concentrated aqueous solution.
The amalgam thus prepared contains, according to Gay-Lussac and Th^nard, 1 part
nitrogen and hydrogen to 1800 parts mercuiy. It contains a certain portion of potas-
sium or sodium, and on this account is less unstable than the amalgam prepared by
dther of the former methods : it may be preserved for a considerable time m anhy-
drous rock-oil, or in an atmosphere of hydrogen.

Formation. — Ammonium-ssJts are farmed by bringing ammonia or carbonate of am-
monium directly into contact with acids.

Properties. — Ammonium-salts are isomorphous with potassium-salts. They hare
mostly a pungent, saline, somewhat urinous taste. They are all soluble in water,
generally with facility : less soluble in alcohol or ether. Ainmonium-salts of colouriess
acids are colourless.

Beactione of Ammonium^salts. Teats for Ammonia. — Ammonium-salts
are variously affected by heat : all, however, are wholly or partially volatilised, with
or without decomposition. The carbonate, and those which contain no oxygen (chloride,
iodide, &c.), are volatilised undecomposed. All others lose their ammonia when heated.
Some, e.g. the phosphate, and borate, evolve ammonia undecomposed, leaving the add.
Others, e.g. sulphate, evolve nitrogen, the add being more or less completdy r«inced
by the hydrogen of the ammonia : the nitrate is decomposed into nitrous oxide and
water. Their aqueous solution, when exposed to the air (still more rapidly when
evaporated), generally loses ammonia, an acid salt, or a normal salt mixed with, excess
of acid, being formed ? hence, in cirstallising an ammonium-salt, ammonia must be
occasionally added during evaporation. When treated with chlorifu^ tiieir aqueons
solution yields hydrochloric add and nitrogen ; or, if tlie salt contains a powerful add,

]

AMMONIACAL SALTS. 189

BjdrocUaric add And chloride of nitrogen (D nl on g). With a solution of hypochhrmu
mi^ dry ammoniiim-aaltB yidd water, chloride of nitn^n, and nitrogen, while nitrogen
and chlorine remain in solution (B al ar d). In solution theyare decomnosed bj pro-
iuiitBt with liberation of ammonia ; not by sesc^uioxides. When heated, either solid
cr in soliitioD, with a fixed alkali, baryta, lime, oxide of lead, &&, they erolve ammonia :
mM^Mma. eroels only half the ammonia, forming a double salt.

TbemctioB by which ammonium-salto are generally detected, is their decomposition
vliCD heated wittt fixed aUkalis or alkaline earthe. If the ammonia erolred be in so minut«
t q[untity that its characteristic smell cannot be perceiTod, it is easily reoo|;nised by
iti prapertf of restoring the blue colour to reddened litmus-paper, and of forming dense
vfaite fumes by contact with a p;lass rod moistened with culute hydrochloric add. If
the erolTed •mmATiU be brought into contact with a strip of paper moistened with a dilute
Mutel soiution of subnitrate of mercury, sulphate of copper, or sulphate of manganese^
in dw £ist case a black stain is produced on the paper, in the second a blue, in the
third a brown. — A solution of mofybdate of sodium containing phosphoric acid (phos-
phomolybdate of sodium), giTes with ammonium-salts, a yellow predpitate, soluble in
aDolii and non-TolatOe organic adds, insoluble in mineral adds : in yezy dilute am-
Bonivm solutions, the formation of the predpitate is gradual; it is accelerated by heat.
When a solution containing an ammomum-ndt or free ammonia is mixed with potash,
and a K^ution of iodide ojmerewry in iodide of potassiwn added, a brown raedpitate
or oolraatioB is immediately produced (Nessler). (NH' + 4HgI » KHgTl + SHI).
Tlik is hy &r the most delicate test for ammonia. —With diehloride of piatinum^
asuDoiuimi-salts giTo a jeQow crystalline predpitate of chloroplatinate of ammonium,
Ftd'NH*, alight^ soluble in water, insoluble in alcohol or acids. When ignited, the
predpitate is conrerted into pure metallic platinum, perfectly free from chlorine,
mth odd tariraie of sodium (or tartaric actd), they give a wmte predpitate of add
tartrate ot ammonium, filightiy soluble in cold water, readily soluble in aUudine solu-
tione and in mineral acids. The carbonaceous residue left on igniting this predpitate
has no alkaline reactioxi. — ^A not too dilute solution of an ammonium-salt gires with a
eoooentnted solution of sulphate of aluminium^ a crystalline predpitate of ammonium-
alooL— Only Tery concentrated solutions of ammonium-salts giye predpitates with
pfreUofftff or fiuosilicic acid, — Subnitrate of mercury gives a hrown colour in solu-
tions eontaining free ammonia. — ^A slightly alkaline solution of an ammonium-salt
giTes a irbite predpitate with chloride qfmfrcury, — ^Alcoholic solutions of ammonium-
salts burn with a blue or violet flame.

Reactions very similar to those just described, e. g. with phorohomolybdate of sodium,
iodomcrenrate of potasdum, di<mloride of platinum, chloride of mercuiy, &c., are
likewise produced by the salts of methylamine, ethylamine, and other compound
ammonias. These oi^ganic bases may, however, be distinguished with certainty from
ammonia its^ by igniting the subeitanoe under examination with oxide of copper,
and pasBsg the evolved gases into baiyta water, when, if carbon ^is present, a
picdpftate of carb(mate of baryta will be produced. (See Analtsxs, Oboanic, p. 226.)

Separation and Estimation of Ammonium. — ^Ammonium is separated from
all other metals except the alkaline metals, by its non-predpitation by hydrosulphuric
add, snlphide or carbonate of ammonium, or phosphate of sodium, in presence of chloride
of ammoniuuL From sodium and lithium it is separated by dichloride of platinum
and alcohol, which predpitates potassium and ammonium as chloroplatinates, while
sodium and lithium remain in solution. The mixed chloroplatinates are converted by
ignition into a mixture of metallic platinum and chloride of potassium, the latter of
vfaidi is dissolved out by water, the solution evaporated to diyness, gently ignited,
and weighed. The weight of platinum ooiresponding to the amount of potasdum
thos obtained being deducted from the total weight of metallic platinum, the remaining
platinum represents the ammonium present : 1 atom of platinum corresponds to 1 atom
of ammoniuuL This method is applicable only when the metals are present as salts which
axe soluble in alcohol, e,g, aa cnlorides. Sulphates are best converted into chlorides
bf adding carbonate of barium, and saturating the filtrate with hydrochloric addL

The bat method for the separation of ammonium from all other metds is to heat
the compound under examination in a combustion-tube with excess of soda-lime, and
to collect the ammonia evolved in a bulb-apparatus containing hydrochloric add. The
chloride of ammonium thus obtained is mixed with excess of dichloride of platinum
(pofeetljfree from nitric add), and evaporated to dryness on a water-bath. The
nsidne is treated with alcohol, which dissolves excess of the dichloride : the chloro-
platinate of ammonium is collected on a weighed filter, dried at 100^ C, and weighed ;
or converted by ignition in a porcelain crucible into metallic platinum, from the weight
of whieh the amount of ammonia is readily calculated. This method is not appliciu)le
to the separation of ammonia from other volatile organic bases.

Ammonium-salts may occasionally be estimated by loss. This is the case when the

190 AMMONIACAL SALTS

ammonimn-Balt is entirely Tolatile, and when no other TolatUe or deegmpoeiMe eom*
pound IB preeent The snbetance under examination is heated in a water-hath until it
ceases to loae weight : it is then moderately i^ted and weighed again, when the Iobb
of weiffht repreeents the amount of ammomnmosalt present TUa is a convenient
method for the estimation of chloride, nitante, or normal sulphate of ammaninin, in
presence ot the oorresponding fixed alkaline salts.

Ammonia may also oe estimated by distilling it into a known quantity of dilute acid,
and determiiung Tolumetrically by a standard alkaline solution the excess of free acid.

The following sie the principal ammonium-salts :

1. AcBTATBs OF AiocoNiux. o, NomuU acetate, C'HKI'.KH^ — A white odouriess
salt, obtained by saturating glacial acetic acid with diy ammonia.

h. Acid acetate, C*H«0» NH* + OH*0« — Obtained as a white crystalline eabli-
mate, when dry powdered chloride of ammonium is treated with an equal wei^t of
acetate of potassium or calcium, ammonia being given off simultaneous^. (See Acas-

TATBS, p. 12.)

2. Casbonatbs or Ajcxomiux. — H. Bose (Pogg. Ann. xlriiL 362^ admits the
existence of a considerable number of carbonates of ammonium, to which he «^«"g"f
yezy various and complicated formuhe. But, according toH. Beville (Compt. rend.
aExxiy. 880 ; Ann. Ch. Phys. [8] xL 87), there exist only two carbonates of ammonium
of definite composition.

a, Normal carbonate, CO^NH*y [or CO'.NH*0 - (70«^fl>.JGra].— This salt has
nerer been isolated. The salt which crystallises from an alcoholic solution of aeequi-
carbonate of ammonium saturated with ammonia, is simply sesquicarbonate. Kexther
can it be obtained from a saturated solution of commercial sesquicarbonate in stzong
aqueous ammonia. It may be obtained in aqueous or alcoholic solution, or, as sesqui-
carbonate, in combination with the add carbonate (b), (Pelouze et Fremy, Traits
de Chimie, ii 222.)

b, Acid carbonate, CO«.NH*.H [or CC^.NB*0 + CO«.-arO.]— Obtained by satorating
an aqueous solution of ammonia or sesquicarbonate of ammonium with carbonic an-
hydride. Or by treating the commercial sesquicarbonate finely powdered, with alcohol
of 90 per cent., which dissolves out normal carbonate, leaving a residue of acid car-
bonate. Sesquicarbonate of ammonium is similarly decomposed by cold water ; bat
in this case, a larger quantity of the acid carbonate is dissolved. All carbonates of
ammonium, when left to themselves, are gradually converted into acid carbonate. It
forms large crystals, belonging to the ri^ht prismatic or trimetric system. According
to D e ville, it is dimorphous, but never isomorphous with acid carbonate of potasaimn.
When exposed to the air, it volatilises slowly, without becoming opaque, ana gives off
a slight ammoniacal odour. At the ordinary temperature, it is soluble in 8 parts
of water ; if this solution be heated above 36^ C, it is decomposed, evolving carbonic
anhvdride. Even at ordinary temperatures, the solntion, whether concentrated or dilute,
gradually becomes ammoniacal on keeping (Gmelin). It is insoluble in alcohol;
but when exposed to the air under alcohol, it dissolves as normal carbonate, evolving
carbonic anhydride.

' It has been found native in considerable quantity in the deposits of guano on the
western coast of Patagonia, in the form of white crystalline masses, with a atrcmg
ammoniacal smell. (Ulex. Ann. Cb. Pharm. IxvL 44.)

c, Sesquicarbonate, C»0^*H» + 2H«0 [= ZC0'.2NH*0 + 8JTa]-.0btained by
dissolving commercial carbonate of ammomum in strong aqueous ammonia, at aboat
30° C, and crystallising the solution. It forms large transparent crjrstals, representing a
right rectangular prism, with the &ces of the corresponding rhombic octahedron
resting on the angles. These crystals decompose very rapidly in the air, losing water
and ammonia, and being converted into di-aad carbonate. This salt may be resaxded
as a mixture or compound of 1 atom of normal carbonate with 2 ot atoms acid caroonate
rCO^. (NH«)« + 2(C6».NH*.H) = (?0»N*H>T : a view which is confirmed by its be-
haviour with water and alcohol ; which, when added in quantitjr insufflcirat for the
complete solution of the salt, dissolves out normal carbonate, leaving a residue of add
carbonate: 100 pts. water at 13° G. dissolve 25 pts. sesquicarbonate, at 17°, 30 pts. ; at
32°, 37 pts. ; at 41°, 40 pts.; at 49°, 60 pts. rBerselius): above this temperature,
carbonic anhydride is evolved, and a solution of normal carbonate formed.

Commerdal carbonate of ammonium {sal volatile, salt of hartshorn, &e.) oonaifltB
of sesquicarbonate, more or less pure. It is prepared on a large scale by the dry dis>
tillation of bones, hartshorn, ana other animal matter. The product thus obtained is
contaminated with empyreumatic oil, finom which it is purified by subliming it once or
twice with 1} times its weight of animal charcoal, in cast-iron vessels over which glass
receivers are inverted. By repeated .sublimation, the salt is partially deconapoeed.
Another method of preparing it is by heating to redness a mixture of 1 pt. chloride or
'' ^^ sulphate of ammonium, and 2 pts. carbonate of caldum (chalk), or carbonatci of potaanimi.

.«■«■

CARBONATES — CHLORIDE. 191

in 1 Rtort to iriueh a reoeiTer is luted : ammonia and water are first disengaged, and
then the seeqnicarbonate distils over and solidifies in the neck of the retort and the
reeaTer. On a small scaler s^ass ressels are employed : on a laige scale, an earthenware
or eist-iron retort, and an earthenware or leaden reoeiyer, which, when filled by
Tcpeated dialallata'ons, is broken or cat in two : 10 pts. sal-ammoniac yield from 7 to 8
piL sesqiiiearbonate. ^8ee DictUmaty of Arts, Mam^faeturea and Mine$j i. 136.) The
alt thus mepared is hable to contain tiie following impuritiee :

i^ipora^itfttifo of ammomum : when sulphate of ammonium, or chloride containing
fnipbate, is employed in the preparation. The salt neutralised with acetic add gives
a white preeipttate which turns black on addition of nitrate of silver. — Sulphate of
amaoniuai, from the same causes : detected by hydrochloric acid and chloride of barium.
— Sd-cmmonute : detected by nitric add and nitrate of silver. — Lead, from the recdver :
the salt has a grey colour, and when dissolved in dilute nitric add, gives the reactions
of lead. — Lime and chloride of caieium, carried over mechanically : from these and
other fijDsd imparities the salt is freed by re-sublimation.

The sesqiiiearbonate obtained as above is a white, transparent, fibrous maas^ with
a pangent caustic taste^ and a strong ammoniacal smelL Exposed to the air, it is
gndnalhr converted into add carbonate. It is oompletdy volatile, though not without
partial deoompodtion. Its aqueous solution is strongly alkaline : from a hot saturated
aohttioitt, the add carbonate crystallises on oooling^ but not in the ordinary aystaUine
kmxL (Deville.)

The aqneous solution of this salt (epiritue eaUe antmoniact), is eztendvdy employed
in medirine as a stimulant. It is also a very valuable reagent. The solid salt is
cmptojed in the manufacture of other ammoniacal salts.

3. CmoBiim of Amcoiouii, CINHl {HydrochloraU or muriate qf ammonia, Sal"
ammomae, etdnavree Ammoniak, Bahniak, Chlorure cPammonium^ or Cklorure am^

Hydroehkrie add gas and ammonia combine volume fbr vxdume, with great evolu-
taoD of hea£, fetming solid chloride of ammonium. This salt forms colourless feathery
oystala, wluch, when examined by a lens, are found to consist of an aggregation of
cubes or oelahedrons. It has no smeB, but a pungent taste ; its specific gravity is 1*5.
It disBolveB in 2*72 pts. water at 18*75^ C, with great reduction of temperature ; and in
about its own wdght of water at 100^. It is less soluble in alcohol When exposed
to the air, it loses ammonia, and becomes add to test-paper. When heated, it vola-
tOiaeB undeoomposed, without previous fudon. After sublimation, it forms white
oystalline masses^ which are exceedingly tough and difficult to powder : to obtain it
in a polvendent state^ a hot saturated solution is evaporated to dryness very rapidly,
with eontimial agitation, when the salt is left as a crystalline powder.

Chkride of ammonium is decomposed by several metals, potassium, iron, &c, a
metallic chloride being formed, and ammonia and hydrogen separated. It is also
decomposed by many salts ; by some, e, g. alkaline and alkaline-earthy hydrates,
oompletelj^, ammonia being evolved; by otheiji, as by cupric and ferric salts, partially,
double salts beinff formed. Some salts, e^g, platinic chloride, combine with it
dizeetiy, fiarming <£mble salts (chloroplatinates). Some metallic hydrates are soluble
in a solution of sal-ammoniac, e^dally those of dnc and maenesium.

Sal-ammoniac is found native in many volcanic regions; auo in small quantities in
sea-water. It is readily formed by heating nitrogenised animal matter containing
chloride of sodium, or with which that salt has been mixed. Until the middle of the
last centuzy, sal-ammoniac was obtained ahnost exdudvdy from £^ypt, where it was
prepared i:n this manner, by subliming the soot obtained by the combustion of camd's
dn^. It is now largdy manufactured in Europe, chieflv from the impure carbonate
of anmxminm which is obtained in gas-works, or by toe dry distillation of animal
matter, niiis carbonate is converted into chloride by the addition of hydrochloric
add, or of the mother-liquor from salt-works, containing the chlorides of magnedum
and caldum, and by evaporating the solution (ammonia beinff added from time to time^^
crystals of sal-ammoniac are obtained. These are contammated with empyreumatic
od, which is destnnred by heating the crystals to a temperature ^ little below their
subliming poinl Tney are then dusolved m water, the solution decolorised by boiling
with animal ehaiooal, and again cr^staUised. The salt is finally purified by sublima-
tion, whidi is performed at a brisk heat, in large glass or euthenware bottles, the
DcdL of wiiidi must be carefully kept unobstructed, to avoid the risk of explodon : the
bottles are then broken and the sal-ammoniac removed in cakes. Metallic receivers
an soinetimes emploTed in the sublimation ; in this case, the outer surfiice of the sal-
ammoniac IS daik-ooloured, owing to metallic impurities, and must be scraped off.

In some manufactories, the carbonate of ammonium is first converted into sulphate,
and sobfieonentlv into chloride. This is generally done by filtering the solution of
cadmiate tmongjk a stratum of powdered gypsum (sulphate of cakium}, when insoluble

192 AMMONIACAL SALTS.

carbonate of calcium is formed, and a solution of sulphate of ammonium obtained.
This solution is mixed with chloride of sodium, CYaporated to dryness, and the sal-
ammftniac separated from the residue by sublimation. Or the solution of the two salts
is eraporatcd at the boiling heat, when sulphate of sodium, being less soluble at a high
than at a lower temperature, mostly crystidliBes out and is removed. The soluticMi is
then cooled, when the sal-ammoniac dystaUises out, since its solubility diminishes
rapidly with decrease of temperature. The crystals thus obtained are purified as
aboTe described. ' Feirous sulphate may be employed instead of gypsum to couTert
the carbonate of ammonium into sulphate ; this is a more expensive process, bat it
possesses the advantage of removing the greater part of the empyreumatic oi!, irhich
IS carried down by the precipitated iron-stidt. (Berzelius.)

In the factory at BuxweUer, in Alsace, sal-ammoniac, phosphorus, and gelatin are
prepared by tiie following ingenious process. Bones are digested in hydrochloric acid,
which dissolves out the bone-earth, leaving the cartilage insoluble : tiie latter is em-
ployed for the preparation of gelatin. The hydrochloric solution is mixed with crude
carbonate of ammonium, when sal-ammoniac is formed, and phosphate of calcium preci-
pitated in the finely-divided state in which it is best adapted for the preparation of
phosphorus. [For ^rther details of the manu&cture of sal-ammoniac, see Dictionary
of Arts, Manufacturea and Mines, i. 141.]

Sal-ammoniac is employed in medicine. In the laboratoiy it serves for the pre-
paration of ammonia^ and carbonate of ammonium, and for frigorific mixtures. It is
employed in dyeing ; also in metal-works, as a deoxidising agent, especially for copper.
A solution of chloride of silver in chloride of ammonium is employed for plating cop-
per and brass. It enters into the composition of a cement used for fixing iron m
stone : this cement is formed by moistening with a solution of sal-ammoniac, iron-
filings mixed with 1 or 2 per cent, sulphur. Impure sal-ammoniac has recentlj been
employed as manure.

4. HTDRiLTB OF Ajofoiauic, KH^H.O. — This compound has never been isolated.
The aqueous solution of ammonia behaves in many respects like a solution of hydrate
of ammonium.

5. NiTEATB OF Ammonithi, NO'.NH* [or NO^,NH^O t^ N0^J<IH*,HO\. {imrwm
flammans.) — Obtained by crystallising a mixture of nitric acid with a slight excess of
aqueous ammonia. It forms long flexible needles : if the ciystallisation be effiscted
very slowly, it may be obtained in six-sided prisms. When the solution is evaporated to
a very small bulk, the salt solidifies into a dense amoiphous mass. It has a pungent
taste. It is soluble in about half its weight of water at 18^ C, and in still less at 100^:
its saturated solution boils at 164^ C, and contains 47*8 per cent salt: when dissolved
in water it produces great cold. It is soluble in alcohol. Exposed to the air, it ddi-
quesces slightly, loses ammonia, and becomes acid. When heated, it foses perfectly
at 108° C, and boils without decomposition at 180°. Between 230° and 260° it is de-
composed into water and nitrous oxide, (NO'.NH* » K-0 + 2H'0). If it be heated
too rapidly, ammonia^ nitric oxide, and nitrite of ammonium are also formed. (Ber-
zelius). When thrown into a red-hot crucible, it bums with a slight noise, and a
pale yellow flame. In presence of spongy platinum, it is decomposed at about 170° C.
into nitrogen and nitric acid. (M i 1 1 o n and B e i se t.)

Nitrate of ammonium is formed when a mixture of nitrogen, o^gen, and excess of
hydrogen is submitted to the electric current; also when hydrosulphuric acid is passed
into a dilute solution of nitric add. It is also formed by the action of nitric acid on
several metals, especially tin.

6. NrrmTB of Ammoniuk, NO^NH< [« ^O'.MP.fl'O].— Obtained by double decom-
position of nitrite of lead and sulphate of ammonium, or of nitrite of silver and chloride
of ammonium : the solution is evaporated in vacuo. Or by passing nitrous fumes into
aqueous ammonia, and evaporating over lime (Mi 11 on). It forms an imperfectly
crystallised mass. It is decomposed by heat into ninogen and water, (NO'.NK* » "S*
+ 2H^0). Its aqueous solution is similarly decomposed, suddenly if acid, gradually
if alkaline.

7. Oxalates of Ammonium. — a. Normal oxalate, C0*(NH*)» + H*0. — Obtained
by neutralising oxalic acid with ammonia, and crystallising. It forms long prisms
united in tufts, belonging to the rhombic, right prismatic or trimetric system : soluble
in 3 pts. cold water, insoluble in aloohoL It is veiy slightly Volatile at ordinaiy
temperatures. When carefully heated to 220° 0. it is entirely decomposed into carbonic
oxide and carbonate of ammonium ; when it is heated more strongly, some oxamide is
formed. Its solution is employed as a reagent for precipitating oucium-salts.

*. Acid oxalate, G*0*.NH*.H + HK). — Obtained in the crystalline form by adding
bxalic, sulphuric, nitric, or hydrochloric acid to a solution of the normal salt. It crys-
tallises in the trimetric system. It reddens litmuSi and is less soluble than the normal

PHOSPHATE — SULPHIDE. 1 93

nit It 18 decompoeed by heat, yieldiBg, among other products, oxamide, (?0^^*,
and oxaBue acid, C'O'iNH^

c QmathxtxalaU, Hp^^er-aeid oxalate, C*0*.NH«.H + C«0*H« + 2HK). — Obtained
hy djatallifling a solution of eqnal parts of acid oxalate and oxalic acid. The ciystals
bdosg to the tzidinie or doubfy oblique prismatic system, and are isomorphous with
the ooR«Q>ondisg potassium salt. They are very soluble in hot water. At 100^ C.
tbey efikxreaee slightly, and lose their water of crystallisation.

8. TsosnuLTss of Ajcmokiuk. — a. Normal phosphate, PO^(NH"*)* [or PG^,ZNH*0.^
— ^When a solution of monacid phosphate or ammonium is mixed with anmionia,
tiiis salt separates as a aystalline magma: it cannot be dried without losing ammonia,
being converted into &.

b. JHammorde phosphate, PO*.(NH*)«.H [or PO».2iVH«0.jyO]. (Ordinary phosphate
of ammonium^ formeny called neutral phosphate,) — Obtained hy adding a slight excess
of Mnmoma or carbonate of ammonium to acid phosphate of calcium (solution of bone-
eaith in hydxt>chloric or dilute sulphuric acid) ; when phosphate of calcium is precipitated,
and monacid phosphate of ammonium remains in solution. It forms large, colourless,
transparent crystals, belonging to the monoclinic or oblique prismatic system. It has
a cooling, saline taste, and an alkaline reaction. Exposed to the air, it effloresces
d%htly, losing ammonia. It is soluble in 4 pts. cola, and in a smaller quantity of
boiling water; insoluble in alcohoL By a red heat^ it is conyerted into metaphospborio
add, PO*.(NH*)«.H = PO^ + 2NH» + H-0).

e. MimamfHome phosphate, PO^(NH*).H« [or P0^.NH*0.2HOJ. (Formerly called
aeid phosphate.) — Obtained by adding phosphoric acid to aqueous ammonia, till the
sohition is strongly acid, and no longer precipitates chloride of barium ; or by boiling
a dilute solution of b and evaporating it to dystaUisation. It crystallises in the dimetric
or square prismatic i^stem. It is somewhat less soluble in wat^ than b, and is
Bimilariy decomposed by heat.

The {^ORiliates of ammonium are employed for the preparation of metaphoephorio
add. As the residue of their ignition always retains ammonia, it must be moistened
with nitric acid, and again calcined. Gay-l«ussac has proposed to preserve muslins
and other inflammable textures from ignition by steeping them in a solution of these
aslta ; the salt being decomposed by heat, the tissue is covered with a film of metaphos-
phorie acid« which preserves it from contact with the air, and prevents its breaking
nto flame. These salts cannot^ however, be applied to fabrics which have to be
washed and ironed, because the heat of the iron would decompose them, expelling the
ammonia. The same objection applies to sulphate of ammonium, which is otherwise
cfficadoua in diminishing the inflammability of light tissues. From recent experiments
by Yersmann and Oppenhein^Pharm. J. Trans. [2] i. 886), it appears that the
only salt universally applicable for rendering such fabrics non-inflammable, is the
neutral tongstate of souimi. (See Tuhgstates.)

Some of the double phosphates of ammonium and other metals are of considerable
bBportsDce. The phosphate of sodium, ammonium and hydrogen, PO^Na.KH*.H, com-
monly called microoosmic salt, or phosphorus salt, is much used as a blow-pipe flux,
being converted by heat into transparent metaphosphate of sodium, which (ussolves
many metallic aalts with characteristic colours.

9- SuLFBLa.TBS OF AxxGNifTV. — o. Nomtol Sulphate, SO*(KH*)« [or 80'.NH*0.]
(fflauber'a Sd seeretum.) — Obtained by neutralising dilute sulphuric acid with
ammnmit OT carbouate of ammonium. It forms crystals belonging to the trimetric or
right prismatic syst^n, isomorphous with potassic sulphate. It is colourless, and has
a very bitter taste ; it is soluble in twice its weight <k cold, and in its own weight of
boihi^. water; insoluble in alcohol. It fuses at 140^ C: above 280°, it is decomposed,
ammonia, nitrogen, and water being given ofi^, and acid sulphite of ammonium
sablimed.

It is found native as Mascoffnine. It is manufactured on a large scale (as already
described nnder Sal-ammoniac) by neutralising with sulphuric add, or decomposing
hj gypaum, the impure carbonate of ammonium obtained m gas-works, &c. and ctys-
tafliaing the solution. The crystals are heated, to destroy animal matter, and purified
by recrystaUisation. Sulphate of ammonium is employed in the manufacture of am-
Booinm-alum : also as manure.

Al Add sulphate, SO*.NH^H, [or 250».^S*0.^rO^.— Obtained by treating a solution
of a with sulphuric add. It crystallises in thin rhombohedrons. It is soluble in ita
own wdght of cold water, and in alcohoL It deliquesces slowly in the air.

10. 8ui.FBXDBfl ov Ajocomiuic. — o. Sulphide, (KH^)^. — ^When a mixture of dry hy-
drac^phnrie acid and ammonia, the latter in excess, is exposed to a temperature of
— 180 C. 2 vols, ammonia combine with I vol. hydrosulphunc acid, and form sulphide
of ammonium. The same compound is formed when sulphide of potassium is distilled

Voi.1. O

184 AMMONIA.

ehlorom anhydride explodes Tiolently at the ordinaxy temperature, with fleparation of
chlorine. Aqueous ammonia added gradually to aqueous hypochlarvua acid, the
mixture being kept cool, yields nitrogen, and chloride of nitrogen. Ammonia mixed
with proper proportions of nitrous or rUtrie oxide^ explodes by the electzic spark, yield-
ing water and mtrogen. Ammonia is violently decomposed at the ordinaiy temperature
by peroxide of nitrogen^ whether liquid or gaseous, with evolution of nitric oxide and
nitrogen (Dulong). — In contact with chlorine in the cold, ammonia bums with a red
and white flame, forming chloride of ammonium and free nitrogen (4NH* •¥ CI' »
3NHK!1 + K); when chlorine is passed into strong aqueous ammonia or a solution of an
ammoniacal-saltk chloride of nitrogen is also formed. — Iodine does not decompose
dry ammonia: in presence of water, iodide of ammonium and an iodine-deriva-
tive of ammonia are formed. — ^With bromine^ ammonia yields bromide of ammo-
nium and free nitrogen. — ^Passed with vapour of phoephorie through a red-hot tube,
ammonia yields phosphide of hydrogen ana free mtrogen. — ^Passed over red-hot ehar^
coal, ammonia yields cyanide of ammonium and free hydrogen. — ^With bietdphide of
carbon^ ammonia gives hydrosulphuric and sulphocyanic aci£ (NH* + GS* -■ H?S +
GSH). — ^When potassium or sodium is heated in dry ammonia, hydrogen is evolved,
its place being supplied by the metal, and nitride of potassium and hydrogen (potassa-
mine), NKH*, is formed. — In contact with zinc-ethyl, ammonia gives rinc-amine NZnH'
and hydride of ethyl, CH*. Many metallic oxides decompose ammonia with the aid of
heat : the products are sometimes water, nitrogen, reduced metal, and more or less of
an oxygen-compound of nitrogen ; sometimes, water and a metallic nitride. — ^Ammonia
reacts with anhydrons adds, chlorides of acid-radicles, and many compound ethen,
giving amio adds, or amides. In like manner, it gives with many derivatives of the
alcohols, amic bases or aTnines. (See Amio Acros, Amio Bases, Aigcdbs, Aionbs.)

We have seen that ammonia is decomposed by certain metals and metallic oxides,
hydrogen being liberated, and compounds formed representing ammonia in which a
part or the whole of the hydrogen is replaced by a metal. There are certain oiganic
compounds {e. g, monobasic anhydrides, compound ethers, &&) which are capable of
decomposing ammonia in a similar manner, with formation of compounds representiiig
ammonia in which the hydrogen is wholly or partially replaced by an organic radide,
acid or basic The numerous and interesting class of compounds wmch are thus
formed from ammonia by the partial or total replacement of its hydrogen by other
radides, orsanic or inorganic, acid or basic, is known by the generic name of oinddes:
under which name they are fhUy described.

Combinations, — 1. With Water {Sdtdion of ammonia^ Aqueous ammonia^ or
simply Ammonia, Spirits of hartshorn, Salmiakgeist, Liquor ammonit).

Both water and ice absorb ammonia with great avidity, with considerable evolution
of heat, and with great expansion. Davy found that 1 vol. water at 10° C. and 29*8
inches barometric pressure absorbs 670 vols, ammonia, or nearly half its weight : the
specific gravity of this solution is 0*875. According to Dalton, water at a lower tem-
perature absorbs even more ammonia, and the specific gravity of the solution is 0*8^.
According to Osann, 100 pts. water at 24° C. absorb 8*41 pts. at 55° C. 5-96 pts. am-
monia. 1 vol water by absorbing 505 vols, ammonia, forms a solution occnpjing
1*5 vols., and havinff specific gravity 0*9 : this, when mixed with an equal bulk dt
water, jields a liquid of specific gravity 0*9455: whence it appears that aqueous
lunmoma expands on dilution. (Ure.)

Preparation. — 1 part of sal-ammoniac in lumps is introduced into a glass flask,
with 1 J parts slaked Ume, and from 1 to 1| parts water : and the flask is connected
by bent tubes with three Woulfe*s bottles. The first bottle, which is intended to
arrest any solid particles that may be carried over mechanically, and any empyrea-
matic oil contained in the sal-ammoniac, as well as to condense aqueous vapour, con-
tains a small quantity of water (Mohr prefers milk of lime). The second bottle con-
tains the water to be saturated with ammonia : it should contain a quantity of water
about equal in weight to the sal-ammoniac employed, and should not be more than
three parts frill, to fdlow for the expansion. These two bottles should be placed in cold
water, and each provided with a saiety tube. The third bottle contains a little water,
to retain any ammonia that may pass through the second bottle. The flask is then
heated in a sand-bath, care being taken that its contents do not boil over: and the
operation continued till about half the water in the flask has distilled over into the fiist
bottle. The first bottle then contains a weak and impure solution of ammonia : the
second a pure and strong solution (if a perfectly saturated solution be required, the
quantity of water in this bottle should not exceed } the weight of the sal-ammoniac
employed) : the solution in the third bottle is weak, but pure.

The proportions of lime and water to be added to the «d-ammoniac in order to pro-
duce the largest yield of ammonia have been variously stated : those given above aro

AMMONIA.

185

now most general]/ nn^eived. According to the equation, CaHO + NH^Cl — NH" +
Old + HH), the amount of slaked lime should be to that of sal-ammoniac as
37 : 63*5, or 69 parts of the former to 100 ports of the latter. But in practice it is
ahrgjFB found neoeiKary to employ a larger proportion of lime ; for not only is the lime
of oommerce alvays impure, but also it is impossible to brinff the whole of it into such
contact with the sal-ammoniac, ajs would ensure the completeness of their reaction.
The object of adding water is to ensure the gradual solution of the sal-ammoniac, and
eoiseqiiently its more complete contact with the lime. There are also other disad-
Tutages which attend the absence of water. If the lime and sal-ammoniac are mixed
in a state of powder, a large quantity of ammonia is lost before the mixture is intro-
duced into the flask ; and the heated mass expands on cooling so as inrariably to
break the flask. These inconyeniences are avoided by first placing the sal-ammoniac
in hunpe in the flask, and then oorering it with the powdered lime : but in this case
the heat required ia sufficient to Tolatilise the sal-ammoniac, which is liable to stop
up the deliveiy-tube and cause a dangeorous explosion. MoreoTer a larger quantity
of empyreomatic oU passes OTer with the anmionia : and the chloride of calcium formed
in the flask obstinately retains a portion of the ammonia, which is consequently lost.
On the other hand, the addition of too much water diminishes the product of am-
monia, and hampers the operation in other ways.

In the preparation of aqueous ammonia on a large scale, the gas is generated in
ctst-iron or copper vessels : earthenware vessels are generally found not to answer,
oving to the porosity of their structure.

The aqueous ammonia thus prepared may contain the following impurities, which
are easily detected :

Corixmaie of ammonium, — Occurs when the Ume employed contains much carbonate,
or when tiie solution has been exposed to the air. Causes turbidity when heated with
chloride of barium.

Chlorine. — Owing to chloride of ammonium having been sublimed, or carried over
mechamcally. The solution, saturated with nitric add, gives a cloudiness with nitrate
ofnlvec

Lime. — Carried over mechanically. Gives a precipitate with oxalic acid : left as a
■olid residue on evaporation.

Copper or Lead. — ^Derived from the generating vessel. The former is detected by the
solution becoming tinged with blue on evaporation ; the latter by hydrosulphuric acid.

EmpynwnaUe oil. — From the sal-ammoniac The solution has a yellow colour
and a peculiar smelL

Prcpertia. — Aqueous anmionia is a colourless transparent liquid, smelling of
»nimAni> and having a sharp burning, urinous taste. Its specific gravity varies from
1*000 to 0*85, according to the amount of ammonia it contains: its boiling-point varies
similaily (see D al to n 's table, if\fra.') A perfectly saturated solution freezes between
—3^ and —41° C, forming shining flexible necnlles: at —49° C. it solidifies to a
grey gelatinous mass, almost without smell (Fourcroy and Yauquelin). It loses
almost an its ammonia at a temperature below 100° C. The following tables have
been constructed, showing the amount of real ammonia contained in aqueous ammonia
of diflerent densities :

Daltov.

H. Davy.

Urb.

aii«iflc

Peremtasc

Boiling

Specific

PerooDUigo

Specific

Percentage

Specific

Percentage

(raruj.

AfwniiHffTi

Poiot.

gravity.

Ammoala.

gravity.

Ammonia.

gravity.

Ammonia.

S5-3

-4*>

0-S750

82-3*

0-8914

87-940

0-9368

15-900

OSS

»6

+3-4°

0-8857

39-25

0-8937

S7-6S3

0-9410

14-575

0<7

»9

10»

O'SfXm

seoo

0-8967

87-038

0-9455

13-250

S7-3

ir»

OD0S4

28-87«

0-8963

86-751

0-9510

11-995

0«

«•?

0-9166

«t)7

0-9000

96-500

0*9564

10-600

*«»

St-9

30°

0-9355

19 54

09045

25-175

0-9614

9 275

»8

370

0-9396

17-52

0-9090

83-850

0-9669

7*950

lr9l

17-4

440

0*9885

15-88

0-9133

29-626

Oir716

6-625

Ift-l

50»

0-9436

14-53

0-9177

21-200

0-9768

5-500

1»8

««»

0-9476

18-46

0-9227

19-875

0-9828

3-975

»M

10-5

63«

0-9513

18-40

0-9278

18 550

0-9887

9-660

»9S

t-s

TdP

0-9545

11-56

0-9320

17'825

0 9945

1-39&

79»

0-9573

10-82

frW

4*1

«r»

0-9597

10-17

•«

97P

0-9616
0-9698

9-60
950*

•Tl

IM6 mmben

weredet4

Brmmed bj

experiment :

the rest in

Davy'i table

by calcutat

lou.

196

AMMONIUM-BASES.

quent decomposition of the iodide bo formed, by hydrate of silyer. The deeompoaitioti
by heat of the hydrates of the ^^hosphontum-bauea, di£Eeis from that of the ooiresiMBiid-
ing ammoninm-bases : e.ff.

P(C»H»)*H.O

Hydrate of

tetrethyl-

pboiphoDium.

P(C«H*)«0 + C^».H.

Oxide of Hydride of

trletbTlphot- ethyL

pbincb

FoLTAicicoNiux-BASBS. — ^These oompotrnds bear to the monammoninm-l
just described, the same relation that the diamines and triamines bear to the man-
amines : they may be considered as representing two or more molecules of hydrate of
ammonium in which the whole or part of the hydrogen is replaced by polyatomic
radicles. As in the case of the monammoninm-bases, l£ere is a difference between the
polyammoninm-bases in which only part of the hydrogen is replaced, and those in
which it is all replaced : the former cannot be obtained in the isolated st«te ; the latter
are stable compounds and possess strong alkaline properties. But both these classes
of hydrates haye been less studied, and are therefore hitherto less important^ than the
corresponding salts, which are for the most part equally stable, whether still containing
replaceable hydrogen, or no. We shall therefore in this article treat of the polj-
ammonium compounds generally, making no essential distinction between hydrates
and other salts, or between those compounds in which the hydrogen of ammonium is
wholly, and those in which it is partially replaced. Moreover, as the bodies of this
class containing phosphorus and arsenic haye been at least as much studied as those
containing nitrogen, it will be most conyenient to speak of the action of polyatomie
compound on l£e basic deiiyatiyes of ammonia generally, taking as special examples
of the yarious reactions hitherto known, compounds containing nitrogen, phoephoras
or arsenic, as these or those happen to be best known.

A Action ov Diatoxio Cslobzdbs, Bboxzdbs, ob Iodides : —

1. On Ammonia,

The experiments which haye been made in this direction are ahnost confined to
the action of bromide of ethylene on ammonia. The products thus farmed axe ti&e
following :

Dibromide of ethylene-diammoniuum . . N'(Ofe*)H*Br*

Dibromide of diethylene-diammonium
Dibromide of triethylene-diammonium

. N«(Cte*)*H«Bi»

. N«(Cto<)»H*Br».
These compounds, when distilled with potash, giye, lespectiyely, ethylenaminev

K«(;C4[*)H*, diethylenamine, N*(C?H«)*H«, and triethylenamine, N«(C«i[«)», bodies
which are likewise acted on by bromide of ethylene, the final product beinff asabstanee
▼eiy analogous to bromide of tetrethylium, and which is probably ubiomide of

tetrethylene-diammonium, K'(C*H*)*Bi'.

2. On Prifnary derivatives of ammonia^ jmmary amines.
Bromide of ethylene giyes with ethylaiome and phenylamine :

Dibromide of ethylene-diethyl-diammonium

NXOB*X(?H»)*H*Bt«
N«(C?H*)«(C«H»)*H:»Bi».

Dibromide of diethylene-diethyl-diammonium
and similar phenyl-compounds.

8. On Tertiary derivaMves of ammonia.

Just as dibasic acids can combine with one or with two atoms of ammonia, so like-
wise can diatomic ethers (such as chloride or bromide of ethylene, or iodide oi methy-
lene) combine with one or with two atoms of the tertiaiy deriyatiyes of ammonia.*
Thus triethylphosphine with bromide of ethylene giyes the compounds —

( V^ / - * «• Bromide of bromethyl-triethylphosphonium " (Hofmann).

(C»H»)«P \

(C«H«)"Br«>
2[(C«H*)T] J

« Bromide of ethylene-hexethyl-diphosphonium ** (H o f m ann).

The condition of the bromine contained in these compounds is worth noticing. T^
addition of nitrate of silyer to a solution of the first compound piecipitates only half
the bromine contained in it, but nitrate of silyer precipitates all the broidine contained
in the second. This difference is explained by Hofinann, by supposing that 1 atom of

* Bromide of ethylene iind lodfde of methylene combine directly with only 1 Atom of Che tertiary
amines, but the compounds with two atoms can be obtained b/ the action of hjrdrObromlc, or hydrlodic
ethers on ethjlenamine.

AMMONIUM-BASES. 197

&y>inine in the first eompoimd is contained in the form of bromeihylt G'H^r : his
-fiev of the oonstitation of the two compounds is expressed in the names quoted
ahoTBw It is not» however, difficult to account for the difference in the behayiour of
the two bromides without making this supposition. When we remember that the
bromine in bromide of ethyl is not precipitated by nitrate of silver, but that it
becomes so immediately bromide of ethyl is combined with ammonia or an analogous
body, it does not seem surprising that one of the two atoms of bromine in bromide of
ethylene should become saline (or accessible to ordinary reagents) when that body is
oombined with ona molecule of a representative of ammoma, and that both atoms
should beeome saline when it is combmed with two molecules of an anunoniarderiva-
fivBL In an compounds formed upon the model of the first compound, only 1 atom of
die salt-ndide is preeipitable by nitrate of silver ; in all those formed upon the model
(^tbe second, both atoms are preeipitable.
The IbDowing are the most important transformations of the above or similar bodies.

a. The compound /nzn*V*p( ^ decomposed by heat thus :

C^^Br') _ TTO^ . C»H«Br

Bromide of vioyl-trfo-
thjdphofpboniam.

5. When > dilute solution is treated with hydrate of silver, it loses all its bromine
and gives /ni^xfp ' [t "vhich may be regarded as a compound of triethylphosphine

with glyeoL Tnis subs(4mce is a strong base, but^ as in the bromine compound, only
one half of the elements combined with the ethylene, are directly replaceable by acid

zadieLes (s.^. hydrochloric add gives /QSH»\sp* [ ) • ^^ bromide of phosphoros, it

regenerates the original bromine-compound. In a concentrated solution, hydrate of .

silver gives (rvmim [,difirering£romthelast substance by the elements of an atom of

wafter. This compound may be regarded as containing oxide of ethylene and triethyl-
phosf^iine, and belongs to the same daas of bodies as the bases * which Wnrtz ob-
tained by the action of ammonia on oxide of ethylene : —

C»H».0 ) 2(C*H*.0)> 3(C«H*.0))

(C*H»)«PC H'NJ H»N J

BUiTkne-trtetnyl- D!eChy1ene- Trlethylene-

faydorpboqdiixM. dihydoramlne. trihydoramine.

e. 'Die same compound is converted by acetate of silver at lOO^' 0. into acetate of
Tinyl-triethylphosphonium, P(C*H»)"0«H».C«H»0«. This reaction probably has two

(C«H»)»P ( ■*■ 2{C»H»AgO«) - (c«H»)>P J + ^^'

(C«H»)*P J " {om*yF ^ + c^ o

If this be so, the second stage of the reaction, is precisely similar to the decomposi-
tion already mentioned of the bromine-compound by heat

tL By nascent hydrogen it is converted into bromide of tetrethylphosphonium : —

e. With derivatives of ammonia, it gives bodies of the type of the second compound.
The fiallowing bodies have been so obtained.

C*H«Br» ) C»H*Br« ) C»H*Br» ^

C«H«Bi«
,(C«H»)»P
{CB^yN ^

,(C«H»)«P
(CH»)«P ,

C»H<Br*
, (C^»)«P
((yH»)«P^

C?H«Br»

,(C«H»;

(0»H

Br« )

»)«AsJ

It has already been stated that bodies of this dass part with all their bromine to
eelts of silver. Hydrate of silver gives 2{((yR^YP'\ \ ^^ dmilar bodies. These
ttze strong bases and give the corresponding salts by the action of adds. 2[Y^H*1^1 [
is decomposed by heat into ^QXQtvtpr* & compound already mentioned, and oxide of

• Am nUoaial nunm for bodtot derlring from the mixed type 2,^o } namely amic bate» and amie

Um terns kmbramine$ and kifdoramida (not to be confounded with hydramides) may be used*
bcr, art. Nombnclatueb).

O 3

198 AMMONIUM-BASES.

triethylphoephine, P(C»H»)«0.— ^C»H»)*P V ia decomposed by heat into /c^^f«ad
triethylarsine, (C'H*)*As.

B. AonoN OF Tblltokic Chlobides, Bbomzdbs, ob Iodxdbs : —

1. On AmmonicL

Tribromide of glyceryl, (C*H*)Br*, giyes -with ammonia a base containing NO^H'lJi*,
and bromide of ammonium. The reaction probably takes {dace according to the
following stages : —

lo C«H*Br» « C*H*Bi« + HBr.

^ 2(0»H<Br*) + NH» - NC«H»Br» + 2HBr,

the hydrobroraic acid which is formed of course combining with ammonia. The first
stage of the reaction is analogous to the conversion of bromide of ethylene into brom-
ethylene by the action of alcoholic potash : the compound, C'H'Br* may be regarded
as dibrom-propylene, or as bromide of brom-allyl, (C'H^r)'Br. In the latter case,

((C«H*Br)
the product of its action on ammonia becomes N. /nsH^^^' dibromrdiaUylamine.

(Maxwell Simpson).

2. On Primary derivativea of ammonia.

Chloroform, (CH)Cl', reacts on phenylamine, forming the hydrochlorate of a monoaod
base, containing, G^'H^'N', and which may be oonsid^ed as representing two moleciiles

of phenylamine in which the radicle ((S!k) replaces H*; thus /q<h«^sh{^'

3. On Tertiary derivatives of ammonia.

Iodoform, (jCHk)!*, combines with three molecules of triethylphosphine^ giving
sr^P^H'^vpi C * '^^ compound parts with all its iodine to silver-salts, which accords

with what IS said above respecting the compounds of bromide of ethylene with trie-
thylphosphine. Its solution treated with hydrate of silver does not give a correspond-
ing hydrate, but hydrate of methyl-triethylphosphonium and oxide of triethylphos-
phina.

sS^yp] + ^^^^ - f^dyp] + 2[(<?H»)»p.o] + sAgi.

C. Acnov OF Tbtbatoxig Chlobides, Bromides, qb Iodidbs on DsBiVATim

OF AjOIONIl.

Bichloride of cazbon, (C)Cl^ reacts on phenylamine thus : —

SCCfffN) + Ca* ^ 8HC1 + C»»H"N".HCL
8 iDol. pheny-
lamine.

The product of this reaction may be regarded as the hydrochlorate of a base de-
riving from three molecules of phenylamine by the substitution of (C) for H^: vi&

ff j

(Tor details, see various papers by Hofmann, Proc. Hoy. Soc vols. ix. and x, also
the Articles PnosPHOBrs, Absenio, ANTDfomr.)

Amicokiux-bases CONTAINING Mbtals. — ^A verv large number of compoonds
have been obtained by treating different metallic salts with ammonia. Some of these
compounds are apparently of similar constitution to the salts of the organic ammoninm-
bases, or to easily conceivable derivatives of them. But it is impossible to reduce the
greater number of them to any consistent system, before they have themselves b«en
more thoroughly examined, ana we have more definite notions as to the atomidfy of
the metals contained in them. The following are examples of some of these com-
pounds which can be written as analogous to known or conceivable oiganie com-
pounds.

i&k*) (unknown.)
(C»H*).

AMMONIUM-BASES — AMORPHISM. 199

litUOic Cmmpotmdt. Organic Analogvtet.

N^«CuCl N.H».C?H*.C1

NHXHg^Cl .... N.H»(C*H»)«C1.

(or N«HXHS)*a«(?) .... N«H^(C«fi*)».CL*

N(Hg)«Cl N(C«H»)«CL

(or ]S^Hg)K31« (?) .... N*(C«ll7CL»

NH>(Hg)Cl« .... N(CH«)«(C«rf)Br».
rH» N

(Hg) . . . . 0-

(Hi) I

KH»(P*t)a« P(C«H»)«(C«rf*)Bi«.

N*H«(Pt)a« I*(C«H»)«(C*tf«)Br».

%*Hg - 200

The attempts which hare heen made by some chemista to make formnlffi for many
other metallic deriTatires of the ammoninm-salta, by supposing ammonimn eapable of
repladnff hydrogen in ammoninxn, or by awmTniTig the existence of such radicles at
PtCl or^O, may be described in words used with reference to another subject, by
the author of one such attempt^ as " unwissenschafUiche Spielereien, die hier keine
Berik* hnVh tigung yerdienen." — G. C. F.

■XQimi* (See Allaictoic and Amniotio Liquids.)

A mineral allied to nickel-glance, and probably identical with it.

(Gm. i 102.) — Solid bodies which do not exhibit any crystalline or
regular structure, even in their minutest particles, are said to be amorp&oue (a, priTatire,
ai^ ^apfH form). Such are opal and other forms of silica, also glass, obsidian, pumice
■tone, bitumen, resins, coal, albuminous substances, and numerous precipitates. Such
bodies hare a smooth eonchoidal firacture, never exhibitingagranulatedappearance on the
broken surfifMe ; they have no particular planes of cleayage, such as are found in dystals^
but require the same amount of force to separate lihem in all directions : they also
oondnct heat equally in all directions, and nexer exhibit double refraction, excepting
wben pKBsed or otherwise brought into a forced state. In short, the essential character
of an amoiphous body is perfect uniformity of structure in eyery direction, each particle
being similarly related to all those which surround it, the character of a fluid without
its mobility, whereas in crystallised or organised* bodies, the molecular fbrces act with
greatest energy in certain lines or axes, thereby determining an arrangement of the
particles According to fixed laws, and causing the body to exhibit different degrees of
teuarity, elasticity, permeability, refracting power, and conducting power for heat and
deetnciW^ in different directions. It must not be assumed that a Dody is amorphous
became it does not exhibit a regular shape in the mass : marble and loaf-sugar haye
BO definite external form ; but they consist of aggregates of minute crystals, and when
broken, exhibit, not a eonchoidal, out a granular fracture.

Hie amorphous state is by no means pecuUar to certain substances, a great number
of bodies being capable of existing both in the amorphous and in the crystalline state.
8n]{^nr, when it solidifies slowly from fusion or solution, forms regular crystals, but
when poured in the melted'state into cold water, it solidifies in a soft^ plastic, yiscid
mass, capable of being drawn out into threads, and exhibiting no trace whateyer
of erystalline structure. Phosphorus also assumes a regular crystalline form when
■bwly cooled from solution in bisulphide of carbon or from frision, but when cast into
moulds and quidEiy cooled, it forms a waxy solid, haying a eonchoidal fracture ; and
by other modes of treatment to be described hereafter, it may be reduced to a perfectly
amorphoos red powder. Carbon is crystalline in the diamond and in graphite ; amor-
phous in charcoal, lamp-black, and the yarious other forms which it assumes \7hen

* Ite Urm mmarpkomi la gcnenllj used in eontradUtiDctlon to crifstaOttu alon« ; bat Iti proper aia
b la cpporidoo to rrgmtoTt whether cryttalHiie or organised : for organic itructuree exhibit many
piopeiUM of wbkb ■morphooa bodies, properij lo called, are destitute ; thus wood, according to the
rweatchaa of Dr. T|ndali, exhiUU three distinct axes of dearage, permeability, elasticity, and.eooo.

O i

300 AMORPEnSM.

separated from organic bodies by imperfect combustion. Boron and silicon exhibit
similar varieties. Arsenions acid, as it collects in the chimneys of Aunaces in which
arsenical ores are roasted, is a elassjr amorphous mass ; but b^ dissolying it in hot
water or hydrochloric acid, and leaving the solution to cool, it is obtained in the cry-
stalline form (see Absenio). Native sulphide of antimony, which is crystalline, may
be rendered amorphous by melting it in a glass tube and plunging the tube into ioe-
cold water : and by melting it again and cooling slowly, the crvetaUine structure may
be restored. Similar tran^ormations may be effected with native sulphide of mejvuij,
also with the minerals Yesuvian and Axinite, and certain varieties of garnet Glass^
which is perhaps the most characteristic of amorphous bodies, may be devitrified bj
keeping it for some time in the soft state at a high temperature : it then acquires a
ciystelline structure and becomes nearly opaque, fbrming the substance called Reau-
mur's porcelain. Generally speaking, rapid cooling from fusion is favourable to the
assumption of iAie amoiphous structure, while crystallisation is promoted by slow cool-
ing, the particles then having time to arrange themselves in a definite manner. It is
alro true to a great extent that bodies which pass at once from the perfectly fluid to
the solid state, — water, for instance, — ciystaliise on solidifying, whereas those which
pass through the viscous form, like glass, solidify in the amoiphous state ; to this, how-
ever there are some striking exceptions : thus sugar, the solution of which is ex-
tremely viscid when concentrated, solidifies by slow evaporation in crystals of great
size and regularity.

The passage from the amorphous to the crystalline state sometimefl takes place
spontaneously, the body all the while remaining solid. Vitreous arsenious acid, wnich,
when recently prepared, is perfectly transparent, becomes turbid when left to itself for
a few months, and subsequently white and opaque. Sugar which has been melted in
the form of barley-sugar is in the vitreous state, but after a while acquires a crystal-
line structure and becomes opaque. These phenomena show that the molecules of
bodies, even in the solid state, possess a certain freedom of motion.

The change from the amorpnous to the crystalline condition, or the oontnury, is
generally accompanied by an alteration of ether physical properties. Bodies are for
the most part denser and less soluble in the crystalline than in the amoiphous state,
and have less specific heat. Yesuvian, which ciystallises in square prisms of specific
gravity about 3*4, and garnet, whidi occurs in rhombic dodecahedrons of specifie
gravity 3*63, both form by fusion and subsequent cooling, transparent classes whose
specific gravity is about 2*96, so that, in passing from the dystalline to the nmoiphons
stete, garnet suffers an expansion of about J and yesuvian of ^. The glass also dis-
solves readily in hydrochloric acid, whereas the ciystallised minenls are quite
insoluble. Many other crystalline siliceous minerals not soluble in acids become so
by fusion, probably from the same -eauses. Quarts, which is oystallised silica, is
much harder and denser than opal, which is the same chemical compound in the
amorphous stete. Quartz-powder dissolves but veiy slowly in boiling potash-ley and
is qmte insoluble in that hquid when cold, whereas pulverised opal is gradually dis-
solved at ordinary temperatures and in a few minutes at the boiling heat. A remark-
able exception to the general rule is, however, presented by arsenious add, which is
both less dense and more soluble in the ciyirt^Uline than in the vitreous state.

Another difference first observed by Ghraham is, that bodies have greater specific
heat in the amorphous than in the crystalline state. Ordinary phosphate of sodium
(PO*Na%) solidifies fiH>m fusion in the vitreous state ; the corresponding arsenate in
the crystalline form : now the former in solidifyinff gives out perceptibly less heat in
a given time than the latter, a greater portion of the latent heat of nision appearing to
be retained by it. Ck>nnected with this law is the remarkable phenomenon of incan-
descence which many bodies exhibit when their temperature is gradually raised.
Hydrated oxide of chromium if heated merely to the pomt at which it parts with its
water, remains nearly as soluble in acids as before, but if the heat be raised nearly to
redness, the oxide suddenly becomes incandescent, and is afterwards found to be much
denser and nearly insoluble in acids. Similar phenomena are exhibited by alumina
and zirconia. Gadolinite (silicate of yttrium) which in its natural stete exhibits a
conchoidal fracture and obsidian-like appearance, becomes vividly incandescent wh^
moderately heated, and is afterwards found to dissolve but very imperfectly in hydro-
chloric acid, although before ignition it is veiy easily soluble ; ito density mcreases at
the some time, though ito absolute weight remains unaltered. Yitreous arsenious
acid also sometimes exhibito incandescence in passing from the amoiphous to the crystal-
line stete. When a solution of the vitreous acid in hot hydrocmoric acid is left to
cool in the dark, the formation of every crystal is accompanied by a flash of li|;ht ; but a
solution of the oystalline add, under the same circumstances, exhibito no light what-
ever.

AMPELIC ACID— AMYGDALIN. 201

An acid iBomeric with salicylic acid, CHK)*, obtained in
■nfl quantity by the action of atrong nitric acid upon those Bchiat-oila which boil
between 80^ and 1 60^ C. Picric add and a floccolent matter are formed at the same time.
AmpeKc add ia a white aubatanoe, without odoor, nearly inaolnble in cold water, but
little aohible in boiline water. Its solution reddena litmua. Boiling alcohol and ether
dinolTe it readily, and on cooling deposit it in the form of a powder, having a scarcely
perecptible oystalline character. Saturatdd with ammonia, it exhibits the following
naetUMML With chloride of caldum, a white predpitate, which does not form when
hot; the mixture depodts dystalB on cooling. No precipitate with the chlorides of
bariiim, stzontium, manganese, or mercuir. A green predpitate with acetate of
nickel ; bine with acetate of copper ; and white with acetate and nitrate of lead.
(Laurent, Ann. Ch. Phya. [2] Iziy. 825.)

AMraUDT. A substance resembling creosote, obtained from that portion of
adust-oQ which boils between 200^ and 280^ C. The oil ia shaken up seyeral times
with strong solphuric add, then mixed with ^ or ^ of its bulk of aqueous potash, and
the liquid is left at rest for a day. The lower wat^ layer of liquid ia tiien separated
from tne upper oily layer, and shaken up with dilute sulphuric add, and the oil which
rises to the sur&ee is remored with a pipette, and gently heated with 10 or 20 times
its balk of vater, which dissolyes the ampelin, leayin^ a small quantity of oil. On
separating this oil, and adding a few drops of sulphuric add to Ihe aqueous solution,
the ampelin rises to the surfiice in the form of an oil, having a slight brownish tint

Ampelin disaolres in 40 or 50 times its Tolume of water, and is separated from the
■ohtiott by a few dropa of sulphuric or nitric add, eyen when yery dilute. Potash, soda,
and their carbonates render the solution slightly turbid at the first instant, but it recovers
its transparency when heated. Carbonate of ammonium renders it permanently turbid.
Chloride of sodium or chloride of ammonium added to a sdution of ampelin in caustic
potash or carbonate of potasdum separates the ampelin, which is then not redissolyed
OB heatiug the Ikjuid. Ampelin dissolyes in alcohol, and in all proportions in ether.
It does not solidify at — 20*^ C. It is decomposed by distillation, yidcung water, a light
oil, and chaicoaL Boiling nitric add attadu it strongly, producing oulic add, and
an losolnble yiscous substance. (Laurent, Ann. Ch. Fhys. [2] Ixiy. 321.)

and AMVBZBOliZTa. (See Hobnblbndb.)

A name applied by Beizelins to salts which, according to
his views, are compounds of two oxides, sulphides, selenides, or tellurides, e, a, sulphate
of copper, CuK).SO' ; sulpharsenate of potassium, SE^S.As'S* ; sulphantimonate of
sodium, SNa^.Sb'S*, &c., — such salts containing three ultimate dements — in contra-
distinction to the haloid-salts, namely, the chlorides, bromides, iodides, &c., which
are binary compounds of the first order, containing only two elements, such as diloride
of sodium, NaCl, iodide of silver, Agl, &c. It is eyident that the so-called amphid
salts are those which bdong to the water-ttfpe^ e. g. nitrate of copper, CuK).N*0* »

0 1^ Sulpharacnate of potasdum, 3K"S.As*S* = S» j^^^'", whereas the haloid-
compoonda belong to the type HH or HG.

See Lbucxtb.

See DroniMm. — AXPKOSSIilTBa See ANORTHmi.

, C**H*0". — ^Produced by the metamorphods of amyedalin
under the infinenoe of alkalis. Amygdalin dissolves in cold baiyta-water without
deeompodtion, but on boiling the mixture, ammonia is disengaged. The ebullition is
continued until the liberation of ammonia ceases altogether; a current of carbonic
add is then passed through the liquid, to predpitate the excess of baryta; and the
aeid is finally liberated from the barium-salt by cautious predpitation vrith sulphuric
add. It is a slightly add liquid, which dries up to a gummy mass, — insoluble in
absofaite alcohol, cold or boilmg, and insolubte in ether. Boiled with a mixture of
peroxide of manganese and sulphuric add, it yidds formic and carbonic acids and hydride
of benxoyL Its salts are not well defined ; they are more or less soluble in water.
(Liebig and Wohler, Ann. Ch. Pharm., Ixiy. 185.)

AmygdaiaU of ethyl is obtained, accordins to Wohler, by dropping a mixture of
alcohol and amygdalin into hydrochloric add gas. (Wohler, Ann. Ch. Pharm. Ixyi.
MO.)

r, C»H«^0" + SH^O.— A crystalline prindple existing in bitter-
>fa»ondi, the leaves of the Cerasus lauro-ceriuus, and many other plants, which by
distillation yield hydrocyanic add. The bitter-almond oil and hydrocyanic add do
not exisf roidy formed in these plants, but are the result of the decomposition of
amygdalin under the influence of emulsin, a nitrogenised fermentable princi^e axisting
with it in the plant

202 AMYL.

To prepare amygdalin, — the oil is expreBs<^ from the paste of bitter-ahnonds, and
the reaidual mass extracted with boiling alcohol. This alcoholic solution is rendend
tnrbid by the presence of globules of oil, whichore allowed to collect and separated hj
decantation; it is then evaporated to half its original volome, and the amjgdaHn
separated by the addition of ether, in which it is insoluble. The precmitated tmyg-
diuin is pressed between folds of bibulous paper, washed with ether, and finally oys-
tallised from concentrated boiling alcohol. (L i ebig and Wo hi er.)

Amygdalin ciyBtallises in white scales haying a pearly lustre, insoluble in ether, bat
yeiy soluble in water, from which it crystallises in thin transparent prisms contaizuBg
3 atoms of water of crystallisation. Its aqueous solution has a slightly bitter tast&
It deflects the plane of polarisation of a ray of light to the -left : [a] » ZS'Sl. The
change which amygdalin undergoes by the action of emulsin (and other albomiDOU
vegetable principles), is expressed by the following equation :

C»H«^0» + 2H»0 « (rH«0 + CNH + 2C«H'«0«
Amygdalta« Hydride Hydro- Gluoow.

ofbenioyl. cyanic
acid.

By distillation with nitric acid, or other oxidising agents, it is resolved into am-
monia^ hydride of benzovl, benzoic, formic, and carbonic acids. Caustic alkalia con-
vert it into amyedalic acid.

It is a neutral body, forming compounds neither with acids nor with alkalis.

ABEVX, 0»H", or C"H« (Gm. xi. pp. 1—83; Gerh, ii. pp. 675— 708). -The
fifth term of the series of alcohol-radicles, G'H^'*'^ The alcohol in an impure state
(potato-fusel oil), appears to have been first noticed by Scheele ; and has been invee-
tigated, together with its derivatives, by Pellet an (J. Chim. med. i. 76, also Ann.

Ch. Phys. [2] xxx. 200), Dumas (Ann. Ch. Phys. [2] Ivi. 314 ; Dumas and Stas,
Ann. Ch. Phys. [2] Ixxiii 128) ; Cahours (Ann. Ch. Phys. [2] Ixx. 81, kv. IM);
and Balard, Ann. Ch. Phys. [3] xii. 294). The radicle itself was isolated byFnuok-
land in 1849. (Chem. 8oc Qu. J. iii. 307 ; Ann. Ch. Pharm. Ixxiv. 41.)

Amyl in the free state, C»H« = C»H".C»H", is prepared by the action of OM-
amalgam upon iodide of amyl, the reaction being completed by the addition of potas-
sium (Frankland). — 2. By the action of sodium upon iodide of amyl (Wurtz).—
3. By the electrolysis of caproate of potassium (Brazier and Gossleth). — 4. By the
destructive distillation of certain kinds of coal (Greville Williams).

(1.) Pasty zinc-amalgam is brought into the copper cylinder used in the preparation
of zinc-ethyl (see Ethyl) : the cylinder is then half filled with granulated zinc and
iodide of amyl is added. After genUy warbling to expel the air, the cylinder is closed
and heated for several hours at about 170° C. After cooling, it is opened and potassitm
is added (about ^th by weight of the iodide of amyl employed). The cylinder is
again closed and neated for an hour at the same temperature. To obtain the amjl,
the cylinder is heated in a water-bath at 80° C, whereupon amvlene and hydride of
amyl pass over. On applying the heat of a naked flame, amyl distils over, and msf
be purifled by one rectification. (Frankland.)

(2.) Iodide of amyl is warmed with sodiuni, and distilled; the product again dis-
tilled from sodium and rectified, the portion which passes over at 158° C. being collected
apart. (Wurtz, Ann. Ch. Phys. [3] xliv, 276.)

(3.) A concentrated solution of caproate of potassium is submitted to the electrolytie
action of six zinc-carbon elements, the platinum poles being separated by a porous
diaphragm. Amyl collects upon the surface of tne liquid surrounding the negative
pole : it is distilled from alcoholic caustic potash and washed with water. (Brasier
and Gossleth, Chem. Soc. Qu. J. iii. 221.)

(4.) Bog-head naphtha is submitted to fractional rectification, the portion boiling be-
tween 164° — 169° C. being collected apart, and the product thus obtained is submitted
to the action of fuming nitric acid, the action of the acid being checked by cold. The
mixture on standing separates into two layers, the upper of which is again shaken
with nitric acid. The product which has remained unacted upon is washed with
caustic soda and water successively, dried with solid caustic potash, and distilled over
sodium. The resulting liquid is again rectified at 167°— 160° 0. (C. Oreyille
Williams, Phil. Trans. 1867, 447.)

Amyl is a transparent colourless liquid, of agreeable smell and burning taste.
Specific gravitv, 0*77 at 1 1° C— Boiling-point 166°— 169° C. Vapour-density 4-90. It
is miscible with alcohol, immiscible with water. Amyl is not acted upon bv faming sol*
phuric acid ; it is slowlv attacked b^ nitric and nitro-sulphuric acids, ana decomposed
after long digestion with pentachlonde of phosphorus.

Beouidb of Ahti.. — Prepared by the action of bromine and phosphorus upon
amylic alcohol (Cab ours, Ann. Ql Phys. [2] Ixx 98). In three flasks are placed reflpe^

AaiYL. * £03

tireir 15 pts. of amjlic alooliol, 2| pts. of bromine, and 1 pt. of phoaphonus. A little
of the bromine is added to ihe amjlic alcohol, and the latter is ponred upon and
digested with the phosphorus to decoloration. It is then poiored into its own flask,
wad a little more bromine is added. The process is repeated, and the final product is
washed with water, dried, and rectified.

Bromide of amjl is a transparent colourless liqpd, heavier than water. It has an
ifliaceoai odoor and sharp taiste. It is soluble in alcohol, insolable in water. De-
eompoaes bj boiling with aleohoUc caustic potash«

CHLoaxsB or AxTL, G*H"GL — Obtained by the action of strong hydrochloric acid
upon amjlic alcohol (Balard, Ann. Oh. Fhj& [sf zil 294) ; also bj the action of penta-
ehloride of phosphoms npon amjlic aloohoL (Cahours.)

PrtparatioH. — 1. Amyiic alcohol is heated in a retort to 110^ C, a rapid current of
hjdrochlorie add being passed through the tubulus into the amjlic alcohol; the
blonde of amjl as it is formed distils oyer. When the retort is nearlj empfj the
distiOate is poured back, and the same process repeated (^Guthrie). The product is
theo shaken with strong hjdrochlorie acid, in which amjhc alcohol is soluble, chloride
of amjl insohible, — ^then with water.

2. Amjlic alcohol is distilled with its own weight of pentachlortde of phosphorus,
wtthed, dried, and rectified.

GUoride of amjl is a 4»lourless, transparent, neutral liquid, of agreeable odour. It
hoils at 101^ C. Vaponr-densitj, 3'8. Bums with a luminous flame bordered with
green.

Chkmne acts upon chloride of amjl, giying rise to substitution-products, which go
as&ri8C*H>Cl«Ci

Ctaxidb 07 Akti.. See CrAiaDEa

Htdbatb of AKTL,orAMTL-Ai.coHOL,C*H«0 « ^^" 1 0 [or C^'iT'O* «

C^ff^OMO]. — Afnylate of Hydrogen. Hydrate of Amyl. Hydrate of Pentyl. Hy*
drgttd Oxide of AmyL Fusel-oil. — ^This alcohol seems inyariablj to accompanj ethjHc
akohol(8ee AiicoHOLS, p. 97) when the latter is formed bj fermentation. The conditions
of its fonnation are unknown; it seems, howeyer, to occur in largest quantitj in those
Bqiiids which remain most alkaline during fermentation. In the disollation of yege-
table juices which haye been fermented, the latter portions of the distillate contain
witer, ethjlic, propjlic (?) butjlic and amjlic alcohols, besides the acids and aldeh jdes
of ^ese aIcoh(U8 and ptrobablj higher fattj acids and aldehjdes. To 'obtain the pure
amvlic aloohol from the crude product, it is shaken seyeral times with hot milk of Ume,
decuited, dried oyer chloride of calcium, and rectified at 132^0.

Amjlic akohol is a transpar^t colourless liquid haying a peculiar odour (the peatj
smell ciwiuskj is duo to its presence in small quantities), which causes coughing, and
buniiig taste. It bums with a white smokj flame. Solidifies at about — 22^ C.
%)eciflc gravitj 0-811 at 19^0. Boiling-^int 132^0. Vapour-densitj 3147.
Soluble in oommoB alcohol and ether, nearlj insoluble in water. It dissolyes small
quantities of sulphur and phosphorus.

Aeoording to Pasteur (Compt. rend. zli. 296), ordinarj amjlic alcohol is a mixture
of two amjlic alcohols identical in chemical composition and yapour-densitj, but
difieiiDg in their optical properties, one of them turning the plane of polarisation of a
T»j of light to the left, while the other is opticiall j inactive. A difference of solubilitj in
raneof the salts obtained from tiie mixed alcohols, famishes the means of their separa-
tion ; the actiye amjl-sulphate of barium is 2| times more soluble in water than the
corre^nding inactive s^t. The optical rotatozj power of amjlic alcohol varies, on
aeooust of its being a variable mixture of these two modifications. This difierenee in
the two amvlic alcohols is said to be traceable in some other of their derivatives, e, g.
^coic add prepared frrom active cjanide of amjl, rotates the plane of polarisation.
O^^ttrta.)

Jkoompositions of Amyl-alcohol. — 1. ^j heat The vapour of amjl-alcohol passed
throng a glass tube heated to dull redness, is resolvea into tritjlene (propjlene)
luanh-gas and other hjdrocarbons. (B ej n o Id s .)

2. Bj oxidation. — Amjl-alcohol is difficult to set on fire, and bums with a white
BDokj flame. In contact with the air at ordinarj temperatures, it iis veij slowlj
oxidised and acquires a slight acid reaction. The oxidation is greatlj accelerated bj
the presence of platinum-black, the amjl-alcohol being then converted into valeric
aeid:

G»H»0 + 0« = C*ff»0« + H'O.

AiQyl.aIoohol distilled withji mixture of sulphuric acid and peroxide of manganese or
bichromate of potassium, jields valeric aldehjde, valeric acid, and valerate of amjl.
The same products, together with nitrite of amjl and hjdrocjanic acid, are formed-
I7 the action of nitric add. Amjl-alcohol is also converted into valeric add bj heat<-

201 AMYL.

ing it to 220^ C. with a xnixtnre of lime and hydrate of potassium, hydrogen gas being

evolved :

C*H«0 + KHO « C«H«0* + 4H.

Amyl- Valente of

alcohol. potatsium.

3. By stdphurie acid. — ^Amyl-alcohol mixes readily witVstrongsnlphniicacid, forming
a red liqnicC which contains amylsnlphnric acid, SO^O^H'^H, as well as free solf^iirie
acid. On <^i«rf-inmg the mixture, the amyl-alcohol is del^drated, and amylene, OH**
passes over, together with the polymeric compounds, C"H* and C"H**, and perhaps
also amylic ether, (C*H"VO ; at the same time, however, a portion of the alcohd is
oxidised and converted mto valeric aldehyde and valeric acijd, sulphurous acid beiiig
evolved and a black pitchy mass remaining in the retort

4. With |?Ao«pAorK?a^, amyl-alcohol ^elds amyl-phosphoric add, PO*.C*H".H".—
Distilled with phosphoric anhydride, it is converted into amylene and its multiples.

6, Trichloride of phosphorus converts amyl-alcohol into phosphite of amyl, amjl-
phosphorous acid, chloride of amyl, and hydrochloric acid :

3(C»H".H.O) + PC1» « PO«.(C»H")'.H + C»H"a + 2HC5L

Fhosphlte of amyl.

and 8(C*H".H.O) + Pa» = PO«.C«BP'.H« + 2C»H»»a + BUL

Amylphotphorotti ''

add.

6. With pentachloride of phosphorus^ amyl-alcohol forms chloride of amyl, hydro-
chloric acid, and chlorophosphoric acid, or, wken the amyl-alcohol is in excess, diamjl-
phosphoric acid :

C*H".H.O + PC1» = C»H"a + Ha + P0C1«

Chlorophos-
phoric
add.

and 9(C»H".H.O) + 2PC1» = SOff^a + 6HC1 + 2rP0^(C»H»»)*.H] + WO.

ulamylphospboric
add.

7. Chlorine^as is absorbed in larse quantify by amyl-alcohol and forms chloramylal,
a compoimd homologous with chloral. — 8. Amyl-alcohol absorbs hydrochloric add gas
and mixes with the concentrated aqueous acid ; on heating the mixture chloride of amjl
is formed. — 9. It dissolves, with the aid of heat, in a concentrated aqueous solutioii of
chloride of /pine, forming a liquid which boils at 130^0., and yields a distillate of amylene
and its multiples. — 10. Distilled with phosphorus and Sromine or iodine, it yields
bromide or iodide of amyl. — 11. Distilled with fluoride of boron, at fluoride of siUam,
it yields amvlene and its multiples, but little or no oxide of amyl. — 11. Phosgene gas
is abundantly absorbed by amyi-alcohol, forming chloroformate of amyl, and the liquid
when distiUed yields carbonate of amyl (Medio ck) [vnth evolution of phosgene (?)]

c»H".H.o + coa« » cao«.c»H»» + Hca.

Phot- Chlorofonnate
gena. of amyl.

and 2(CaO«.C*H") - CO«.(C*H»*)' + COa« [?]

Carbonate of
amyl.

Carbonate of amyl is also obtained by adding water to the solution of phosgene in
amyl-alcohol (M e d 1 o c k) :

2(CC10«.C*H«') + H»0 « 00».(C*H»>)« + 2Ha + C0«.

21. Disulphide of carbon, in presence of potash, oonvertB amyl-alcohol into amylsal-
phocarbonic or amylxanthic acid (p. 2Q6). — 13. Chloride of cyanogen is rapidlr
absorbed by amyl-idcohol, and forms products similar to those which it yields wim
ethyl-alcohoL

C*H"0 + CNa + H»0 « C«ff «N0« + HCL

Amyl- Amjl-ure"

alcohol. thane.

Amyl-alcohol combines with a few metallic chlorides in the same manner as ethyl-
alcohol. With chloride of calcium and dicMoride of tin, it forms aystalline com-
pounds which are decomposed by water. It dissolves in caustic potash and soda.

Htdbidb op Amyl, C*H".H. — Iodide of amyl is heated with sine and its own
volume of water for a few hours to 142° 0. in a copper cyKnder (see zinc-ethyl), and
the contents are distilled from a water bath at 60*^. The distillate consists prindpeJly
of amylene and hydride of amyl. The mixture is left for 24 hours in contact wid

AMYL. 205

erastie potesh, and again rectified from a water-bath at 36^. The distillate is
iniiMned in a freezing mixture and treated vith a mixtore of anhydrous and filming
waifbuic add, which retains the amylene. Lastly, the hydride of amyl is distilled
from a water-hath (Frankland, Ann. Ch. Pharm. IxxiT. 41). Colourless transparent
hqiiid, luTiog a pleasant odour. Specific grayity 0*638, at 14^ C. Boiling-point
30° GL YapoDr-density 2*382.

lonini or AmtLi C*H"L — ^Prepared by the action of iodine and phosphoms upon
amylie akohd (C a hours, Ann. Ghl Phys. [2] Ixz. 81). Ponr parts of iodine are
placed in one flas][, and excess of phosphoms in another. Seven parts of moist amylie
aleohol are poured npon the iodine, the liquid shaken tlQ opacity is produced, then
poured upon the phosphonis and dieted till the colour is removed — again poured
jtfGa the iodine, and so on, till all the iodine is exhausted. The nearly colourless
product bo obtained, ib washed with slightly alkaline water, dried over chloride of
eakinm and rectified. The latter portions are the purest.

Iodide of amyl is a colourless transparent liquid of &int odour and pungent taste.
Specific gravity 1*611 at 11® C. Boiling-point 146<>. Vapour-density 6-676. It turns
iKDwn on exposure to light.

OxiDB OP AxTi., C"H*=0 = (C*H")«0 For C^^IPWl — Amylie ether, AmylaU
of AstyL — Prepared by the action of sulphuric acid on amyl-alcohoL Strong
nlphmic acid is heated to 150° C. in a retort, and amyl-alcohol allowed to enter
dovly throngh the tubnlus ; the distillate is then shaken with carbonate of sodium,
washed and rectified. — ^2. By the action of amylate of potassium on iodide of amyl.
Amjiate of potassium is digested in a retort, connected with an inverted con-
dooer, with an equivalent quantity of iodide of amyl, and the product is distilled and
leetified — 3. By the dry distillation of amylsulphate of calcium (K^kul^). Oxide
of smyl boils at about 180® C. It is colourless and of agreeable odour.

Oxide of Amyl and £Myl, C'H»«0«<?H».OH".0. Amylate of Ethyl, Ethylaie
9f Am^ Etkylamylic Ether. Prepared by the action of amylate of potassium upon
iodide of ethyl, or of iodide of amyl upon etbylate of potassium. (W illiamson, Chem.
Soc. Qq. J. XV. 103, 234.) — (1.) A known weight of potassium is dissolved in absolute
alcohol in a tubulated retort ; iodide of amyl is added in sufficient quantity for there
to be rather less than 1 at. of iodine for every at. of potassium in the ethylate of
potaannm; the retort is connected with an inverted condenser; and the contents
are digested for some time. After distillation, water is added, and the liquid which
separates out is dried and rectified. — (2.) Iodide of ethyl is added to a hot solution
of potash in amylie alcohol, digested &c, asinl (Guthrie). Amylate of ethvl is
a ookorlesB transparent Hquia of agreeable odour, similar to that of sage. It is
bg^ter than water. Boiling-point 112*^0. Vapour-density 4*04.

AmylaU of Methyl^ or MethylaU of Amyl, C«H"0 - C*H"0, is prepared in the same
manner as (1) amylate of ethyl (Williamson). Boils at 92^ C. Vapour-density
374.

Amylate of Potassium, C*H"KO. — On bringing freshly cut potassium into diy
amrlic alcohol, the potassium is dissolved and hydrogen is evolved. To obtain this
body in a state of purity, the action is aided by heat until the mass becomes viscid.
Any gloVoks of metal which have remained unacted upon are removed, and the pro-
duct is poured upon a cold slab, and allowed to solidify. It is then strongly pressed
between many fmds of bibulous paper to remove the unaltered amylie aloohoL

Aoiylate of potassium is a Grystalline white body, soapy to the touch, and alkaline
to the taste. It is soluble in the alcohols. By water it is instantly converted into amylie
aleobol and hydrate of potassium.

Aii^flate of sodium, CH"NaO. Closely resembles amylate of potassium.

StriPHinns of Ahtx. IProto sulphide of Amyl. (0»H")"S or C"H«S.—
Equivalent quantities of amylsulphate and monosulphide of potassium are intimately
Bnzed in a retort (by solution and evaporation) and distilled (Balard, Ann. Ch. Phys.
[3] xiL 248). Colourless liquid of offensive odour. Boiling-point 216^ C. Vapour-
aeiisity 6-3.

Dieulphide of Amyly CHIT'S. — Obtained by distilling together amylsulphate and
disalphide of potassium (O. Henry, Ann. Ch. Phys. [3] xxv. 246). Amber-coloured
hqail Boiling at about 260^. Specific gravity >9 18 at 18^ 0.

ga/j»Atigg of Amyl and Hydroyen: Amyl-mercaptan, C»H".H.S [or (^•W^S.ffS.]
Aoared by saturating caustic potash with sulphuretted hydrogen, adding the
|»oanct to crude amylsnlj^hate of potassium (prepared by mixing equal weights of
amylie alcohol and sulphuric add, neutralising with carbonate of potassium and filter-
nig) and distilling from a capacious retort in a chloride of calcium bath. The oily
drops in the distillate are washed, dried, and rectified (Kreutzsch, J. pr. Chem.
'^'* 1). Coloorkfls Hquid of intolerable odour. It is soluble in alcohol and ether.

206 AMTL.

but insolnble in water. Specific gravity 0845 at 09 C. Boilin^point about 120^ C.
Vapoar-density 3*631. It combines wiUi metallic oxides.

Amylmercaptide of mercury is obtained as a colourless liquid on brin^;ing amyl-
mercaptan in contact with mercuric oxide. The mixture solidifies to a solid maas on
cooling. The compound is insoluble in water, but soluble in boiling aloohoL Tlie
other amylntercaptides are not distinctly known.

Sulphide of Car bony It Amy I, and Hydrogen, AmyUulpkoearbome aad,

Amylxanthie acid, CH'^H) » c*H" h[ "^ — ^^^ ^^ ^^ ^ prepared from the

potassium-salt by treating the aqueous solution of the latter with dilute hydrochlorie
acid (Balard, Ann. Ch. Phys. [3] xii. 307). light yellow oily liquid, of penetrating
odour, heavier than water, acid to testpaper. It is quickly decomposed bv wnter.

AmyUcanthate of potaesivm^ C*H".K.S*0. — A cold saturated solution of hydrate of
potassium in amylic alcohol, is treated with bisulphide of carbon until the alkalini*
reaction has disappeared, and the yeUow ciystals of the potassium-salt which a^Mrate
out on cooling, are washed with ether, and dried between blotting paper.

The ethyl and methvl salts of amylxanthie acid, are formed by digesting eqniTalent
quantities of ethylsulpnate or methylsulphate of potassium, with amylsul^ocarbonate
of potassium, lliey are oily liquids lighter than water. (Johnson, Chem. See Qn. J.
V. 142.)

Dioxysulphocarbonate of Amyly CH^S^O.— The compound so-called, which contains
1 at. hydro^n less than amybcanthic add, is produced by the action of iodine
on amylxanthate of potassium. It is an oily liquid which boils at 187^ C, iindergoing
decomposition at the same time, and yielding among other products amylxanthate of
amyl, GS^.(OS?*)*. Digested with aqueous ammonia, it yields amylxanihaU of

ammonium, and aanthamylamide or ^phocarbamate of amyl, ^ nsH" ( O

2C«a"S«0 + 2NH» - CS«O.C»H"jna[« + C«ff«NSO + S.

•- ^ -^ *-

Dioxyralpho. Arajlxanthato of Xanthamy-

caibonato of amnonium. lamide.

amyl.

The last mentioned compound, xanthamylamide, is a yellow neutral oil, which boils
at 184° C. but not without decomposition, being resolved by distillation into amyl- ■
mercaptan and cyanuric acid :

3C«H'»NS0 - 3C»H»2S + C«N»H»0«.

Heated on platinum foil, it bums with a vellow luminous flame, eiving oflT white
vapours. Boiled with hydrate of barium, it is resolved into amyl-alcohol and anlpho*
cyanide of barium :

(>H»«NSO + BaHO « C»H»«0 + CNSBa + H*0;

similarlv with potash. It is decomposed by chlorine and by nitric acid.

Xantnamvlamide is insoluble in water, but dissolves readily in alcohol and ethec
It imites with chloride of mercury, forming the compound (^'*NS0.4Hi^^ which
crystallises in white featheiy crystals. With dichloride of platinum duBolved in
water, it forms a vellow precipitate. (M. W. Johnson, Chem Soc. Qu. J. r. 142.)

AmystUphocarbafmc acid, C*H"NS^ (see next page).

Tellubidb of Amtl, or Tbli.ubahtl, (C*H'*^*.Ta. has been obtained in
an impure state by diBtilling telluride of potassium with amylsulphate of «^l<nTim
It is a liquid having a strong disagreeable odotir, and boiling at about 198^ C. but
decomposing at the same time, aod depositing tellurium in small shining pfrisma. By
exposure to the air it is converted into a white mass. The nitrate of teUoramyl
is a colourless heavy oil, obtained by heating telluramyl with moderately strong ni^e
acid. Treated with the bromide, chloride, or iodide of hydrogen or sodium, it yields
the ' corresponding compounds of telluramyl in the form of viscid heavy oils. The
chloride treated with oxide of silver, yields oxide of telluramyl in the form of an oily
liquid soluble in water, and so strongly alkaline that it separates anunonia from sal-
ammoniac. It forms a crystalline salt with sulphuric acid. (Wohler and Bean, Ann.
Ch. Pharm. xcvii. 1.)— F. O.

Amtlahinb, C*H:"N « C*H".H>.N. Amylammonia, AmyUa.'-'rbjB oiganic base
is formed: H.) By heating cyanate orcyanurate of amyl with caustic potash (Wurts,
Ann. Ch. Phy«. [3] xxx. 447) :

CNO.C»H» + 2KH0 « C»H>«N + CO«K«

Cyanate of Hydrate Amyla- Carbonate

amyl. ofpotas- mine* ofj

ilun

lum. aium

AMTLAMINES. 207

(2.) In the dealructive distUUtion of animal substances (Ander8on).^3.) By heat'
b^ amylralphate a£ potassium with alcoholic ammonia to 250^ C. (Berthelot). — (4.)
By the dry distillation of leucine, carbonic anhydride being at the same time eyolyea
(Sehwanert* Ann Ch. Pharm. cii. 221):

C^»»NO« = C*ff »N + CO*

Leucine. Amyla-

mtne.

Also bj carefbllY distillinff a solution of horn in strong caustic potash, leucine being
then formed and afterwards decomposed as above (S c h wan er t). — (6.) By the action
of esostic potash on flannel, tetiyhunine being also found among the products. (Gr.
Williams, Chem. Gaz. 1858, 310.)

PrnaraHon. — Cyanate or cjanumte of amy! (obtained by <^i«*:i'lling cyanate of
potaasinm with amylsulphate of potassium) is distilled with strong caustic potash ;
the distillate is neutralised with hydrochloric add, evaporated and reciystallised ;
and the faydrochlorate of amylamine decomposed by distillation firomlime and rectified
over hydrate of barium. Colourless liquid! Specific gravity 0*75 at 18^ C. Boiling-
point 94^ C. Amylamine precipitates most metallic oxides which are predpitable
by ammonia ; it redissolves alumina.

Carbonate of amyinmine is formed as a crystalline solid, when its base is exposed to
the carbonie add (rfthe air. — Hydrobromate of amylamine^ OH'^N.HBr, or bramide
of itmyHutiL, C^H"NBr, is formed by adding hydrobromie add to the base. — Hydro-
cktoraU of an^lamine, C»H>«N.Ha or chl^mde of amylium, C*H»«NC1, forms* with
diefakffide of platinum a double salt, OH^'NCLPtQ*, which is soluble in boiling water.

Am^s^phocarhanuiUofAmyUum,C^m^^^ N(H»;0»'h>^" | S ' is P«xl^»^
by the union of 2 molecules of amylamine with 1 molecule of bisulpnide of carbon :
(C^'H^NS* « 2C*H"N + CS«). The mixture of the two substances becomes warm,
and on cooling deposits the compound in whito shining scales, insoluble in water and
in ether, bnt easily soluble in alcohoL At 100^ C. it decomposes after a while, giving
off nUphuretted hydrogen. Treated with hydrochloric add, it yields chloride of

amylium, and amylsulphocarbamie add ^ H ( q ' "^^ich. is an oily body,

soluble in ether, ammonia and potash; mixed with amylamine, it reproduces the
^ saUa. (A. W. Hofmann, Chem. Soc. Qu. J. xiii. 60.)

DiAMTtAMiNB, (C»H")«HN.— When amylamine is heated to lOO^^C. with bromide
of amyl, direct combination occurs, and the solid hydrobromate of diamylamine is formed.
The base is obtained by distillation of the bromide with caustic potash (Hofmann,
PhiL Trans. 1851, p. 357). Slightly soluble in water. Boiling-point about 170^.
The salts of diamylamine are difficidtly soluble in cold water, more readily in hot

TBrAXTLAMiNB, (C*H")'N, is obtained by heating diamylamine with bromide of
ly], and distilling the so-formed bromide of triamylium with caustic potash (Hof-
mann). Its propertiee and those of its salts are similar to those of diamylamine. It
boils at about 257^ C.

TsTBAXTLiux, N(C^")*. Tetramylammontum. — ^Ammonium in which the whole
of the hydroeen is replaced hj amyl. Not known in the separate state, but obtained
as an iodide by the action of iodide of amyl on triamylamine, the mixture solidifying,
after three or four days' boiling, into an unctuous o^stalline mass. The iodide of
tetmmylium is also produced, but very slowly, by heating iodide of amyl in a sealed
tube with strong aqueous ammonia. This salt, N(C^H").I, dissolves sparingly in
water, f<Hining an extremely bitter liquid, from which it is precipitated in the crystal-
line £arm by alkalis. Boiled with oxide of silver, it yields a very bitter alkaline solu-
tion of the kydraie of tetramylium :

N(C»H")M + AgHO = Agl + ^^^*^"^|o.

On mixing the liquid with potash, or concentrating it strongly by evaporation, the
hydrate of tetramylium rises to the sur&ce in the form of an oily layer, which
pindnaBy ■olidifie& A moderately concentrated solution of the base left to evaporate
in an atmosphere free from carbonic add, deposits the hydrate in definite crystals
sometimes an inch long, and containing several atoms of water of ciystallisation.
These aystals when heated, melt in their water of crystallisation, and ultimately
leaTB the pure hydrate in the form of a semi-solid transparent mass. At higher
tempentiires, the hydrate is completely decomposed, giving off water, triamylamine,
snd a hydrocarbon, which is probably amylene :

208 AMFLENE.

N(0»H'«)*H.O « H«0 + N(C»H»»)« + C»H»

Hydrate of Triamy- Amylene.

tetramylium. lamine.

Hydrate of tetram jlinm dissolyes readily in acids, fbrnung eolntions vUch yiold
crystalline salts by evaporation. The sulpnate cryBtallises in long^ capiUuy tfarads :
the nitrate in needles, the oxalate in large deliquescent J^tes, the chloride in Umins
with palm-like ramifications; the chloroplatinate, (049")*NGLPtCl*, in bentiM
orange-yellow needles. (Hofmann, Chem. Soc Qn. J. ir. 316.) — ^F. G.

(For the Amyl^hoaphinea^ Arsines, and Stibines, see FHOsPHO&xrs, Anfflnm^ ud
Amtdcont.)

AMTlXSn. G^H>*, or C^W\ — ^This hydrocarbon, a homologae of ethyleDeor
olefiant gas, and the fifth term of the series, C"H^, is produced dy the dehydntion
of amyUc alcohol by sulphuric acid, phosphoric anhydride^ or chloride of sine, also bj
the dry distillation of amyl-solphate of calcinm (^eknl^). To prepara it^aooft-
centrated aqneons solution of chloride of zinc is heated to 130^ 0., with an equal ToliUDe
of amylic alcohol : and the product is distilled from, a water-ba^ over caustic potash,
and repeatedly rectified (Balard, Ann. Ch. Phys. [3] xiL 320). It is a transparent
colourless, Teiy thin Uquid, having a fEunt but onensiye odour. Boils at 39° C.
(Balard); at86*(Frankland); at420(E^kuU). Vapour-density, 2*68 (Balard),
2*386 (Frankland), 2*43 ^E^kuU); (by calculation, for 2 yoL -^ 2-4266). The
yapour is rapidly and completely absorbed by sulphuric anhydride and pentacfalabde
of antimony (Frankland). It possesses anaesthetic properties, and has been tried
as a substitute for chloroform, but has been found to be yezy dangeroos, having in
more than one instance led to fatal results.

Amylene is diatomic, like ethylene, uniting with 2 at. Br, NO', HO, &&, and vith
1 at 0, S, &c.

AcBTATB or AicTLHMS, CEL^K)^ a (CE^OY \ ^'' ^ producod by heating the bo*
mide CH^'Br*, with a mixture of acetate of silyer mixed with glacial acetic arid:

C»H»Br« + 2(C«H«O.Ag.O) = 2AgBp + /ctslo)*! <>*•

It is a colourless neutral liquid, insoluble in water, boiling above 200^ C. and euily
decomposed by alkalis into acetic acid and amylene-glycoL (Wurts, Ann. Ch. JPhTi.
[3] Iv. 468.)

Bbomidb of Ahylhnb, CH^'Br*, is produced by passing bromine-vapour into unj-
lene. Heated in a sealed tube with alcoholic ammonia^ it forma bromide of amnio-
nium, and bromamylene^ C^H'Br. — By treating amylene with a larger quantihr of
bromine, another compound is formed, containing OH^r*, probably dutromuu «/
broTnamylenCf C^H'Br.Br'. This compoimd, treated with alcoholic potash, yields di-
hromamylene^ C^H'Br*. (Cahours, Ann. Ch. Phys. [3] xxxviii 90.)

HTDSA.TB OF Amtlsmb, OP Aktlknb-Gltool, C*BPH)* =■ m '(0*. — Prepared

by distilling acetate of amylene tidth dry pulverised hydrate of potassium, and poxifiad
by a seoond distillation in the same manner, and subsequent rectification jwr m:

(C^?l°* + 2KH0 - 2(C*h«b:o«) + ^'^*jo«.

It is a colourless, very syrupy liquid, having a bitter taste with aromatic afte^taft&
When cooled with a mixture of solid carbonic acid and ether, it solidifies into a hiid
transparent mass. It does not affect polarised light. Its specific gravity is 0*987 at
0^ C. It boils at 177^, and distils without alteration. When pure it dissolves in yater
in aU proportions. The aqueous solution turns acid when exposed to the air in contset
with platinum-black, yielding chiefly carbonic acid, with only a small quantity of a
fixed acid, apparently butylactic acid. When gently heated with nitric arid, it is
rapidly oxidised, the chief product of the action being butylactic acid, CH^»
(Wurtz, loc, cit)

Amylene-glycol, treated with hydrochloric acid, either gaseous or aqueous, is oon-
yertecC slowly at ordinary, more quickly at higher temperatures, into the eUorhgdm
of amylene-glyeol^ C*H**.H0.C1. This compound cannot be isolated by remains dis-
solvecl in the excess of acid and is decomposed by distillation. The acid sedation
treated with potash yields oxide of amylene.

NiTHTLiDB OF AuTLBKB, C»H»^NO*)« NUroxtde o/ Jiiivfon^.— Obtained by
passing peroxide of nitrogen (nitryl, NO', prepared by heating anhydrous nitrate of lead)
into a fiask containing amylene, and surroui^ed by a fbaezing mixture. The gas ii io-

AMTLENE. 209

rtntlr absorbed, and the amylene is gradnaHy oonyerted into a pasty mass of minntd
aysfaa^ which may be purified by Tmshinff with oold alcoho], reciystallisation from
bdling ether and drying in racno over suphnric acid. It gave by analysis, 37*26
per cent. G» 6*61 H, and 17*66 N ; the fbrmnla requiring 3709 C, 618 H, and 17*28 K.

The eompoimd ma^ also be obtained, though less advantageously, by passing vapour
of amylene mixed with air into foming nitric acid. It is remarimble as affording the
first examine of the direct combination of nitzyl, (NO'), with an organic radicle.

Heated br itself in a dry tube, it decomposes at about 95^ C, giving off nitrous an-
hjrdride^ IPO', and nitrons acid, HKO', and leaving a heavy liquid apparently containing
niiMte of amyL Heated with quick lime, it gives off an aromatic body, probably con-
sating of oxide of amylene. (Guthrie, Ghem. Soc Qu. J. xiii, 45, 129.)

Oxnn OF AsncLBNB, (CH*')''.0, a volatQe liquid, isomeric with valeric aldehyde,
It boils at 9SP C. Has a pleasant ethereal odour, and a rough taste. Specific gravity
in the Uqnid state, 0*8244 at 0° 0. Vapour-density by experiment 2*982, by odcula-
tioo (^2 voL) a 2*806. It bums easOy, with a yellow flame. It is insoluble in water,
and is not converted into amylene-glycol whei^ heated with water in a sealed tube.
It disBolreB in alcohol, in ether, and in a mixture of the two. It mixes with acids. It
unites with asihfdraus or crystalUsahU nitric acid at a higher temperature, but the
oraabiiiatioii is attended with partial decomposition. (A. Bauer, Compt. rend.
litfOO.)

AxszjDOi mTH SuLFRUB AKD Chlobdib :

L Dieklorogulphide of Amylene, C^«SC1«, or C^JI»»i8»CZ*.— Protochloride of sul-
phur (8CP) is brought into a flask surroxmded with ice and an excess of amylene
added Xfacj gradually. The excess of amylene is evaporated o% — ^the residue digested
and washed with water, dissolved in ether, filtered, and evaporated. It is a non- volatile
liquid, having a pungent odour, insoluble in water, soluble in ether and alcohoL
^peciilc gravity, 1*149 at 12^ C. Distilled with excess of alcoholic caustic potash, it
yieldB amylene, dindpkide o/fiuyl (C^B*8), and other products.

2. JDisulpkochloride of Amylene, 0*H>*SG1, or C^»IP*£Pa,— On treating disulphide
of ddoirine (SCI), with excess of amylene, and evaporating the latter, a transparent
yellow, non-volatale liquid, of faint and nauseous odour is obtained, having the above
composition. It is obtained pure by digestion with water, solution in ether, filtration,
and evaporalion. Specific gravity, 1*149 at 12^ C. Soluble in ether, absolute alcohol,
and snlnhide of carbon. (Guthrie, Chem. Soc* Qu. J. xiL 112.)

BiBii^ihochlaride of amylene treated with chlorine, gives off hydrochloric acid, and
is eomreitedinto a non-volatile liquid, of specific gravi^ 1*406 at 16^ C, miscible with
ether, iiisolnilde in water, but soluble in hot alcohoL This liquid gave by analysis
nmnbera agredng approximately with the formula, C^*WCl*8, which may be that of
cUoromdpSde o/triciloranwlene, C^IPO^XSa, or that of sulphide of tetrachloramyl,
C^B'Cfiya, (Gmthrie, Ohem. Soc Qo. J. xiii 43.)

Ainxfisni wtee Bvlpsur asd Oxygbn :

Ditfdjphoxide of Amylene, C^^IP^SPO, — ^Prepared by digesting the disulphochloride in
akohobc solution with protoxide of lead, till all the chlorine is combined, dissolving in
ether, filtering and evaporating. Specific gravity, 1*064 at 13^ G. Non-volatile, yeUow,
or almost colourless. Soluble in ether and alcohol, insoluble in water.

Hydrate of Disulphoxide of Amylene, Q^B^S'O.HO, — ^Disulphochloride of amylene is
heated in alcoholic solution for some hours, in a current of ammonia ; the liquid is then
poured off fiom the chloride of ammonitim formed, and heated for some hours in a
sealed tube to 100^ C. with alcoholic ammonia ; the excess of alcohol is driven off
in a water-bath ; the residue treated with water ; and the oil which is thereby pre-
eipitated is washed with water. Yellow liquid of meaty odour. Somewhat soluble
in hot water, soluble in alcohel and ether. Kon-volatile. Specific grarity 1*049 at
8P. (Gnthrie, Chem. Soc Qti J, x* 120.)— F. O. and H. W.

if C**H^O». or C»*J2«0'.— This add is contained, together
with eardol, io the pericarps of the cashew nut (Anacardium oocidentale). The pericarps
aie extraeted with ether, which dissolves out both the anacardic add and the eardol ;
the ether is distiUed of^ and the residue, after being washed wilh water to free it from
tanniii. Is dissolved in 16 or 20 times its weight of alcohol. This alcoholic solution is
digfsted with recently predpitated oxide of lead, which Amoves the anacardic add in
the tbni of an insoluble lead-salt The lead-salt is suspended in water, and decom-
posed by sulphide of ammonium, and from the solution of anacardato of ammonium,
obtained after the removal of the sulphide of lead by flltration, the anacardic add is
liberated by the addition of sulphuric add. After repeated purification by solution in
alooliol, eoDversion into a lead-salt, and decompodtion of this salt by hydrosul-
pfaaxic add, the add is obtained as a white crystalline mass, which malts at 26^ C. It
VOL.L P

210 ANACARDIC ACID — ANALYSIS-

luui no smell, bat its flATonr is aromatic and bnrning. When heated to 200^ 0. it u
decomposed, producing a colourless yery fluid oiL It bums with a smol^ flame, stains
paper, and liquefies by prolonged contact with air, emitting an odour smiilar to that
of rancid fat Alconol and ether dissolve it readily, and these sdutboB reddea
litmus.

Some of its salts are crystalline, others amorphous. The silver-salt is a polTenleDt
white precipitate, soluble in alcohol, in presence of a free add. It contaba tvo
atoms of metal, C**H*'AgK)'. The lead-salt> obtained by mixing a boiling alcoholic
solution of anaoffdic acia with an alcoholic solution of acetiite of lead, is aaid to ooa-'
tain O^H*«Pb^O' or C*^JS^Flf'0' ; if this formula be correct^ the add is tetnbasie
[or dibasic, if the smaller atomic weights of carbon and o^gen are used]. The sahs
of ammonium, potassium, barium, calcium and iron, have been described, but they ik
not very definite, and their formulae have not been fixed. (Stadeler, Aim. GL
Fharm. Ixiii. 137.)

JLVA&CXMBt ^**UsiO» + BPO - Na«O.SiO« + Al«0«.3SiO* + H«0 or

SNaO.SiO* + S{JJPO*,2SiO^ 4- 2 HO.—A mineral belonging to the seolite fianilj
containing, according to H. Boee's analysis, 65*7 per cent, of silica, 13*5 soda, 23'0
alumina, and 8*3 water, which agrees very nearly with the preceding formda. It
belongs to the regular system. Primary form a cube ; it occurs also m lendte-octi-
hedrons, and in cubes with the fistces of the leudte-octahedron r6pladn|r the solid
angles. Cleavage indistinct, parallel to the faces of the cube. Specific gravity from 2-1
to 2*2. Softer than felspar. In its purest form, it is colourless and transparait^ bat
sometimes white indining to grey or fiesh-colour. According to Brewster, it pdanM
light in a peculiar manner, indicating a grouping of the molecules vety different from
t^t which is usually found in the re^:alar system. Before the blowpipe, it loses viter
and becomes milk-white ; but when the heat is increased, it becomes dear again, and
then melts quickly to a transparent glass. It is readily decomposed by h^drodilone
add, with separation of visdd silica ; after ignition, however, the decompositioii is \m
easy. Analcime occurs frequently in defts and geodes in granite, trap-rocks and lara.
It is found on the Calton HOI, Edinburgh, at Talisker in the Isle of Sky, in Bmnbarton-
shire, in theFerroe Islands, in the Hans, and in Bohemia.

rA&T8zs— orosaAvio.

The object of chemical analysis is to ascertain the composition of any Bahstaooe
whatever. The distinction usually made between organic and inorganic eompouids,
has led to a corresponding division into organic and inorganic analysis: the latter
being confined to the investigation of inorganic or mineral compounds. The metfaodf
employed in this branch of analysis, are far more numerous and varied than thoN
hitherto devised for the analysis of organic compounds. Inorganic analysis is divided
into qualitative and quantitative analysis. The former teaches qb how to ascertain the
elements of a substance with regard to their quality only, and how to separate them ooe
from another : the latter establishes the methods of proceeding, by whidi we detennine
the relations of weight or volume, which these dements bear to one another. It is
obvious that, before we can proceed to estimate the quantities of each dement con-
tained in a compound, we must know what are the elements that it oontaixis : benee
qualitative must always precede quantitative analysis.

^ Analvsis is one of the most recent of the various branches of chemical sdence. Cob-
siderable progress had already been made in synthetical chemistiy, in the prepanticn
of chemical compounds, &c. at a time when the foundations of uialyticau ehemis^
(in the sense at present attached to the term) had not even been laid. Leas than a
centuiy ago, when the properties and compounds of many dements were dther entirely
unknown or but imperfectly established, few problems were more difiScult than that w
inorganic analvsis: the analyst had need of both penetration and caution in the highest
degree, in order to discriminate between known and tmknown substances. It ia qdIj
within a comparatively recent period, that the discovery of many new demeats, and
the more complete investigation of the reactions of those already known, have enaUd
us to construct a systematic conrse of analysis, drcumscribed within definite and vdl
established rules.

Analytical chemistry, as we have already observed, aims at two objects, each oloady
connected with the other : — 1. To ascertain what are the dements contained in sob*
stances whose composition is unknown : — 2. To determine the rdative proDOitions of
those dements whose existence has previously been qualitatively asoertainecL In the
earliest analvtical researches, both these objects were pursued simultaneoudy. Henoe^
in the very brief sketch of the history of analytical chemistry, which it is sov oar
purpose to eive, it is not possible to trace the progress of eadi of these branehes (£
analysis independently of the other, for this purpose it is more convenient to tdopt

AN ALYSIS— INORGANIC. 2 1 1

the dntinetuw of Analysis in ike wet and tn the dry v>ay (vide infra) : for these two
bnadia of uuljaia aimed onginallj at different objects, and tiie progress of each
w in gKtt messore independent of that of the other.

The earliest analytical methods of which we hare any information were in the dry
WIT. Tlie7 were directed ezdnslTely to the separation of noble from, ignoble metals;
aid thejr were generally conducted qnantitatiTely, the object being to determine the
eoounerdal valve of alloys, &&, by extracting the amount of the most precions metal
eoDtainedin them. Aa early as the second centory B.a, Agatharchides of Unidos (quoted
hj Dioionu Sieahis) gives an account of a method employed by the Egyptians for the
otnctioa and piirificati<Mi of gold, which closely resembles the process of cupellation,
at pneent so eoctensiTely employed for the separation of silver from lead. Strabo
(about the Christian era) describes the extraction of silTer from its ores by fusion with
kad; and all the analytical methods which we meet with in the course of several
sneeenTe eentories are but modifications of the same process. We find a description
oftheproeeasgiTen by Geber in the latter half of the eighth century, which corre-
^onda TtTj clteely with that at present employed.

8taetly apeaking; the employment of anialysis in the dry way for qualitative pur-
poaea, ia of much later date, commencing from the observation of the behaviour of
difftrait metallic compounds when exposed to a high temperature in contact with
certain reagents, commonly called fluxes. It is to Pott, Profeasor of Chemistry at
betliBy arc 1750, that we owe the first distinct record of these observations ; he
pointed out that it was possible, by the addition of certain fiuxes, to fiise many
anhatsiifm which were infusible alone ; and that the colour of the fused mass afforded
infonnation as to the nature of the original substance. This method of experimenting,
vhiehwia eonducted by him in crucibles and fumades, on a comparatively large
Male, reeeived an immense extension by the introduction of the blowpipe, by means
of whidi £ir more accurate indications were obtained with a much smaller quantity of
the anginal sabstaneew The first mention of this implement occurs about 1660, in the
MoDoia of Uie Academia del Gimento, at Florence, when it ia noticed as being em-
piojred by ghsa-blowexs ; and the first indication of its use for chemical purposes, is
mnd in Konkel's Ar9 vitraria expertmentaHs, 1678. Cramer, a German chemist, in
hi BemaUa JfHs doeinuutiom (1780), ^ves the earliest instructions for its use as
an implement of analysia. The fiirther mvestigation of the results to be attained by
nieana of this invaluable instrument} was effected mainly by a succession of Swedish
GhemiatB, of whom Cronstedt and Bergman were perhaps the most remarkable ; and it is
to Beadiiis that the establishment of the existmg system of blowpipe analysis was
finalbf ovin^

Aeooiding to the present oonrae of analysis, the method by the dry way is usually
employed onfy in the psdiminaiy examination : the cases are very rare in which its
resolts can be relied upon fot complete information as to all the constituents of a
anhatanca For this purpose^ reeouise is now invariably had to analysis in the wet way.
The early hiatoiy of this method of analysis is vexy obscure, amounting in fact to
nothing bat the enumeration of a few random reactions, in the employment of which
ooayatem was obsesvedL It was originally employed solely for the quahtative detection
of adnltentions in drugs, &c. It was next directed to the examination of mineral
vaten, to which purpose it was mainly confined until the latter half of the seventeenth
eenta^, at which penod the first true perception of the problem -involved in analytical
ehoaiatiy was obtained b^ Boyle, who gave to this branch of the science the name by
vhieh it is at pcesent designated. He was tilie first to establish clearly the idea of a
^emittl dement, and to seek for methods of ascertaining what elements or known
eDBBSoonds are contained in any substance of unknown composition. Although these
methods e(Mnprise many reactions which were known before his time, still he has the
credit of being the first to generalise these scattered fiicts, and to collect them into a
ohaKntaystan. Among the new reactions introduced in his time, we may mention
the precipitation of calcium-salts by sulphuric add, as serving for the detection of
eithv eaieium or sulphuric add ; of silver^salts by hydrochloric acid, as a test for
both silver and ehozine ; that of iron with tincture of galla ; the blue colour of copper-
■ihs vith excess of ammonia^ dec. Since the time of Boyle, analytical chemistry, in
the hands of Harggzaf| Scheele, Bergman, Klajnoth, H. ^iose, &c. has made continual
advueas, the enumeration of which cannot be attempted in a blief historical summary
Kke the present ; ontil by degrees it has assumed the systematic form of which wo
•hall presoitly {ooceed to give an outline.

The establishment of quantitative analysis, as a distinct branch of chemical sdence,
ii of eoBBpantmly recent date. For a long time it was almost entirely neglected,
little if any importance being attached to the relative proportions in which elements
ematin a compoand. Until the latter half of the last centory, it was confined to the
pnzposa of aanying, or of determining approximately the value of ores ; and it was not

F 2

212 ANALYSIS-INORGANIC.

until Layoiflier, with sacli triumphant success, employed the balance as a means of
refuting old errors and of establisning new traljis, that inquiries into the quantitttiTO
composition of bodies came to be r^arded as the only sure test and foundatioii for
chemical theory. Almost all the quantitatiye analyses by which any reUable know-
ledge of the constitution of substances has been obtained, are included in tiiis penod,
and date within the last 60^ or 70 yean. The empirical results thus obtaineo, hxn
led to the discoveiy of the most important theoretical truths, e. g, the theory of atoms
and equiTalents, the law of multiple proportions, &&, which in turn have been of in-
estimable yalue in controlling the results of analysis, and ensuring to them a degne of
aocunUT which could neyer hare been attained by merely empirical determinatioDs.

Until a comparatively recent period, the only method of quantitatiTe analysis was
that by vmaht. By this method, the substance to be estimated is either vd^ied
directly, or m the form of some compound of known composition, from whose w^gfat
that of the substance to be estimated is readily calculated, the reagent by whidi the
substance is separated being always employed in excess. More recently, another method
has been introduced, which depends upon the employment of only the exact qnantitj
of the reagent which is necessary to produce the reaction desired ; and upon the dfr-
termination of this quantity, not by weight, but by measure. This method, knovn as
the Volumetrie method of analysis (see Akaxtsis toluxbtbio), is only applicable
in cases where the point at which the reaction is complete can be deteimined aeea-
lately by means of some distinctly visible phenomenon occurring in the solution to be
analysed. The first introduction of this method is due to Descroizilles, who, at tbe
dose of the last century, applied it to the valuation of bleaching powder by means of
indigo-solution : since whicn time it has been gradually extended until it has grovn
into a distinct and most important branch of anuysis, which, in most cases, is at least
equal in accuracy to the method by weighty while it is greatly eupeiior in ^eed aad
facility of execution.

The methods of qualitative analysis oonsiat in brin^g the sobstanee nnder ex-
amination into contact with other bodies of known properties, and observing the
phenomena which ensue. These phenomena consist in alterations, either in state of
aggregation, form, or colour, depending upon some chemical change. AUbodiea^bidi
we employ for this purpose, we call by the general name of reagents, the ensaing phe-
nomena are called reaetions. Acids, bases, salts, and simple bodies (elements) an
alike used as reagents.

By means of reagents, the ehemiat puts questions to the substance under exanisir
tion, enquiring whether it contains this or that group of chemically similar elements,
or only this or that member of such group. If the question be put correctly— i& if
all the conditions under which the reaction expected can be produced by the leagait
employed be carefully observed, the answer is decisive as to the presence or absence of
the element, or group of elements, sought: if, on the other hand, these conditions'
a. e. the properties and chemical relations of the bodies formed by the chemical ehiDga
which constitute the reaction, have been wholly or partially neglected, the ansver, if
not certainly erroneous, is at least of doubtful accuracy.

Keagents may be employed either in the tost way or m the dry way. In the wetvsT,
the reagent in solution, i. e, in the liquid form, is brought into contact with the sub-
stance to be examined, which is also in the liquid form. In the dry way, the tvo
bodies are brought together in the solid state, and subjected to a high tempeiatiiT&
Of the utmost importuice in analysis by the latter method, is the knowledge of the
use of the blowpipe, and of the behaviour of bodies in the djifferent flames which es&
be produced by it. (See Blowfifb.)

Many reagents exhibit the same, or a similar behaviour, with a certain fixed nnmbff.
i. e. with a group, of elements, and with most of the compounds of these elementa ; and
can therefore, be employed for the division of the elements into groups. Soch reagents
are termed ^«nera/ reagents. Others serve for the further distinction of the seversl
members o/^such groups : their selection depends upon the knowledge of the spedsl
characteristic behaviour to such reagents of each single dement^ or of each of its
several compounds. Such reagents are called special or oharaeteristio ree^etUs, Their
number is much greater than that of the general reagents, l^eir natore being as varioos
as that of the substances which can come under examination : their selection deq^ds
upon the solubility or insolubility, colour, or other physical or chemical properties of
the new compounds to which they give rise. They may frequently be employed re-
ciprocally : thus, starch is a characteristic test for iodine, and ledproeaUy, iodine is a
characteristic test for starch.

The analyst has not only to establish that this or that body is present in aoompoond,
but he has also to prove that no other body is present besides those which ns has
actually found. Hence it is evident that he must not treat the substance nndff ex-
amination with any reagent induMrimiaately. He must follow a certain fixed order,

ANALYSIS— INORGANIC. 213

I metlHMfiflil fljatem, in the application of reagents, which will be the same for all
inoigiiiie sahetanees whateyer, let their elements be what thej may. This systematic
method, vhich cannot be departed from or abbreviated wiUiont danger, except in
certain cases bj the experienced chemist^ consists in the employment of general reagents
iat the successxTe eUmmation of gron^ of elements possessing certain conmion chemical
^KfottkB; and finally, in the recognition of each member of soch groups by the em-
pbymeat of characteriaric reagents. If the object be n5t a complete and accurate
uaijais, but merely to establish the presence or absence of some particnlar body, the
chsnetmstic reagent may in many cases be employed at onee, without preyions
nooQiM to generw reagents.

The fint thing to be done in the qnalitatiTe analysis of a solid body, is to subject
it to a pRliminaiy eTamination in the dry way, by which means important information
18 to its composition may fireqnently be obtained : after which it is dissolved, and ita
eoBstitnenti aseeortainfid by framinajaon in the wet way. The oounM of qnalitativB
a]nlylil^ therafine, consists of 3 parts :

I JMxminaiy examination in the dry way.
IL Sdution, or oonversion into the liquid form.
HL AoaljBis of tiie solution in the wet way.

We ahsll now proceed to trost soceessively of each of these operations.

L Prdminary ExanUnaiion.

Tbaa consists partly in an aocuiate observation of the physical properties of tbe
nbatanee (its form, colour, hardness, speciflc gravity, &c) : but chiefly in observing
its behaviour at a Jdgh temperature, either alone, in contact with air, or with some
ckemiol compound which produces either decomposition or simple solution.

1. The tubkanee ia heated alone in a dry test-tube, on charcoal, or on platinuinrfoU,
~ Water, sulphur and its adds, ammonium-, arsenic^, and mercoiy-compounds are
eooplelely volatilised. Carbon burns when heated in the air. If water is evolyed,
obeore whether it is add or alkaline to litmus. If gases are cYolyed, observe whether
they are oonbiistible : and if so, whether their combustion is sustained or intermittent,
(hganifi oompounds are decomposed by heat^ generally with evolution of inflammable
gas aad sepsntion of carbon : when heated with strong sulphuric acid and bichromate
of potMiinm, they erpolye carbonic anhydride, which gives a white predpitate with
hale- or bazyta-water. Bodies which are very rich in oxygen, nitrates, chlorates, per-
chkratea, bramates, iodates, deflagrate when heated on charcoal. Host alkaline, and
some alkaline-earthy salts, melt without Tolatilising or changing colour ; after strong
ignitioD, the residue is alkaline to test-paper. Many silioites (espedaJly seolites)
melt whan a thin fragment of them is exposed in platinum-tongs to the blowpipe flame.
Borates and almn swell up: other salts, e. g. chloride of sodium, decrepitate. Of
metals: antimony, lead, tin, bismuth, cadmium, zinc, tellurium, fuse readily before
the blowpipe, giving an incrustation of oxide; gold, silyer, and copper, fdse with
difteolty, and giye no incrostation ; iron, nickel, cobalt, molybdenum, wolfram, and
piatiaom metals are inftasible. The oxides and salts of the earthy and alkaline-earthy
metals are infusible, or difllcnltiy fhsible ; they become yividlj incandescent, with a
vhite light, but do not change colour; the earths, after ienition, are not alkaline to
test-paper. The oxides and salts of some metals assume a darker colour when heated :
those of zin^ tin, titanium, columbium (niobium), and antimony, become yellow: those
of lead, bismuth, mercury (and chromates), become dark-brown.

silieatea |;ive a blue infutiUe nuua : zinc-oxide and titanic luhydride become yeUotoish-
$rten: bmoxide of tin, bhaeh-green: antimonic andcolumbic anhydrides, dirty-green:
nagnesia and tantalic anby&des, fieelnred: baryta, brown or brick-red: ^ucina^
Hme^ and atrontia, gr^-

1 7%e eubstance is heated on platinum-tnr$ (if a metallic salt, on charcoal) in the
i^ner blowpipe flame, and the cohur of the outer flame observed, — A, yellow colour in-
dicatea aodium : a f^det, potassium : a carmine^^, lithium or strontium. The yellow
eoloar imparted by sodium, completely oyerpowers those of the other alkaline metals:
bat, if the flame be observed throujg[h dark blue slass, the yellow rays are cut ofl; and
the edoars of potassium and lithium are plainly visible, even in presence of a large
ezcesi of aodium. A reddish^yeUow colour indicates calcium ; a yeUow-green, barium or
Bolybdennm ; a green, cupric oxide, phosphoric, boric, or tellurous add ; a Uue, arsenic,
SBtimouy, lead, selenium, or cupric chloride. In many cases, the colour is rendered
^"^^ ^ipazent if the substance be previously moistened with hydrochloric add, or a

p 3

214 ANALYSIS— mORGANia

little chloride of fiilver added: phosphates and borates should he moistefied vitli
sulphuric acid.

The delicacy and sharpness of these chxomatie indications are greatly inereased hj
a method of obserration lately introdnced by Bnnsen and Kirehho£ It oooaiti
mainly in igniting a metallic salt on platinum wirs, in a feebly Imninons and neailj
monochromatic &me, such as that of a Bonsen's gas-bnmer, and obseniog the
flame through a prism. Very characteristic spectra are thai prodooed, edntaiui^
luminous coloured bands coincident in position with certain of f^unhofei'B lino.
Sodium gives a spectrum reduced to a single bright nanow band; Utkiim, a fanght
red and a fainter yellow band ; poiassiumf a spectrum nearly resembling the ordinvj
solar q)ectrum in the middle, but characterised by a bright line near the red ex-
tremity, and a fainter line near the violet end of the spectrum. The stnmam
spectrum consists of a broad brisht orange band, with some fiunter red hands; tlie
(foleium spectrum, of a broad brignt green band, a somewhat narrower bright oru^
band, and some fainter yellow bands; and that of bariufn, of several bngfat grwo,
yellow and orange with two faint red bands. The sodium reaction is extremdj
delicate, sufficing for the detection of a quantity of sodium as small as jg^m^
a milligramme ; distinct indications are likewise obtained with ^^^A^^ of a milli-
gramme of lithium, j^ milligramme of potassium and barium, y^^os isHligniniDd
of strontium, 16566666 nuUignmme of calciunL (For details see the artide Laaa ; abo
Pogg. Ann. ex. 161 ; Chem. Soc. Qu. J. ziii. 270.)

4. l%e substance is heated on charcoal in tie reducing flame with eorhonaU of
sodium^ or toith carbonate of sodium and cyanide of potassium. — Most aZBenic eom*
pounds give a smell of garlic All sulphur-, selenium-, and tellurinm-oompomids, gire
an allumne sulphide, selenide, or telluride, which, when moistened, leaves a buck
stain on a clean silver plate. Tin-, silver-, copper-, and gold-compounds givemaUeaUe
shining scales : compounds of nickel, cobalt, iron, molybdenum, wolftam, and thr
platinum-metals are reduced to a grey infusible powder: no incrustation is fanned in
any of these cases. Antimony-compounds give a brittle metallic globule, and a iriiite
incrustation: bismuth, a brittle globule and a brown-yellow incrustation: lead, a
malleable globule, and a yellow incrustation. Zinc and cadmium are not reduced to
the metallic state, but give, the former a white incrustation, not volatile in the outer
flame, the latter, a brown-red incrustation.

5. ITie substance is heated in a ^lass tube, open at both ends, held ohU^f,—'^
following substances yield gases having a peculiar smell : sulphides, of bunung emlphor;
selenides, of horseradish ; arsenides, of garlic ; many ammonium-salts, of ammonia;
fluorides (especially on addition of microcosmic mlt), of hydrofluoric acid. A metallie
sublimate indicates arsenic- or mercury-compounds : a white sublimate is given "bj
arsenides (crystalline), by antimonides and tellurides, (fbsible), and by many ammonip-
salts. A fused sublimate is given by the higher sulphides (brown-yellow), by selenidfs
and selenium (blackish-red), and by sulphide of arsenic (yellow). All h^^ted salts
or substances containing hygroscopic water yield drops of water, the acid or alkaline
reaction of which should be ascertained.

6. Ihe substance is heated in contact with metallic ginc and dilute hydroMrie or
sulphuric add. —Many metallic acids are reduced to lower oxides by this treatmeDt,
a change of colour being produced. Titanic acid gives a violet colour : tungstic add,
and the chlorides of tantalum and cohimbium, a blus : molybdie acid, blue, changing to
green and dark-brown : oolumbous acid, Hue, changing to dark brown: chromic add,
ffreen, iodic add, brown, or if starch be added, blue.

n. Solution of Solid Bodies.

After having ascertained by the preliminary examination in the dry way, to vliat
class of bodies the substance under examination belongs, the next step is to bring it
into the liquid form, in other words, to dissolve it. In o^er to effect this, it is generally
necessary, when the nature of the substance allows it, to reduce it to a fine powder by
pounding in a mortar, and, if necessary; by subsequent levigation with water. This
IS indispensable in the case of minerals, especially of silicates, and of all other difficnlUy
soluble, insoluble, or difficultly decomposible compoimds. If the substance contains
oxganio matter, this should be removed before proceeding further, as its presence
materially interferes with the reactions of many minenJ compounds. This may gene-
rally be effected by heating the substance strongly for some time in contact viui air
(more speedily with oxygen), until the whole of the carbon is converted into carbonic
anhydride. In many cases, the oxidation of the carbon is. facilitated by dropping nitric
acid on the heated substance.

The solvents which are usually employed in the analysis of inorganic bodies a«
water, hydrochloric and nitric adds, and aqua-regia. The finely-powered snbstance
is first boiled with from 12 to 20 times its weight of distilled water, in order to ascertain

ANALYSIS— INORGANIC. 215

Hb eooplete or partial Boliil>ility gp inflolubili^ thereiiL If it be not completdj dis-
nhed, the aohitioii is fQtcred off from the residue, and a drop or two of it eraporated
to diyness on platinnm-fi)!], when, if the sabstanoe is partially soluble in water, a dis-
timet residiie is left ; if the snbstance is completely insoluble, there is no reetdoe after
wpoamtion. In the former ease, the solution is tested with Utmns papor to see whether
it has a neutral, add, or alkaline reaction, and set aside for further examination.
The pootion insobiblft in water is then treated suoeessiyelj with dilute 9nd> concentrated
kjfdneUorie acid, particular attention beinff paid to the nature of the gases, if any,
iha^Tf erolvvd, and to the separation of aoud products of de<x>mposition. Carbonates
evnlve carbonie anhydride^ with effervescenoe ; peroxides, duromates, and chlorates
STohe dilonne; ^anides, hydrocyanic acid; many sulphides, hydrosulphuric add;
solpfaitea and hyposulphites, sulphurous anhydride, with separation of eulphur in the
latter cases. Host metals (iron, dnc, tin, &c) evolTo hydr^en ; or, if arsenic or an-
timony be present^ arsenide or antimonide of hydrogen. If hydrochloric acid does not
eompletely dissolTe the substance, it generally effects the complete separation of one
or more elements ; for which reason the solution should be separated from the residue,
end esamined uart. The residue may consist of compounds undeoomposible by
hydiochlozic adi^ which existed in the original substance ; or of insoluble compounds
fonned l^ the decompodtion of the original substance by hydrochloric add. Thus
solpbiir IS separated from pdysulphides, pulverulent or gdatinous silica from many
wlicatei, tmi^itic add from tungstates, &c. ; or if lead, suver, or subsalts of mercury
be preeent; insoluble chlorides of these metals will be formed.

n the sabatsnee is not completdy soluble in hydzodilorio add, the insoluble reddue
is treated snceesuYdy with nitrie acid and amta regia. In many cases («. g, with
phosphates, arsenates, silicates, tungstates, &c), these compounds act merely as sdyents;
on many other bodies they exert an on'dimng action. Thus, most sulphides, when
treated with nitric add, separate sulphur, whi(£, by prolonged disestion with the add,
collects into jeSiow globnles which swim on the su^hoe of the liquid, or disappears
altogether, being oxidised into sulphuric add, which may be detected in the solution,
unless it forms an insoluble salt with the dissolved metal Sulphide of lead is con-
voted \fj nitric acid into snlphate of lead : sulphides of antimony and tin into white
oxides: protoenlphide of mercury is insoluble in nitric add, readily soluble in aqua regia.
Most metals are completdy soluble in nitric add : the only metals not attacked by it
are gold, platinum, and the rarer metals found in platinum-ores (with the exception
of pelladiiim, whidi is slowly soluble in nitric add). Gold and platinum are soluble
in aqua regia. Tin and antimonv are not dissolved by nitric acid, but are converted
into white oxides, insoluble in the acid ; thej are readily soluble in aqua regia (or
hjdrodikrie add and chlorate of potasdum\ if excess of nitric acid be avoide£

When a findy powdered substance is neitner dissolved by suocesdve treatment with
the above solvents, nor so decomposed or attacked by tiiem as to give an idea of its
natnrc^ it most be rtndcred solubis, in order that its constituents may be determined
in the wet way. The method of doing this frequently depends upon the results of
the pdiminaiy examination. The following are the prindpal insoluble (or difficoltly
Bohilkle) substuoes.

1. Adpiaieg (of barium, strontium, cslcium, and lead). When heated on charcoal
with carbonate of sodium, they give an alkaline sulphide : sulphate of lead gives also
a maTleahle metallic globule; it is blackened by sulphide of ammonium, and soluble
in basie tartrate of ammonium. They are rendered soluble by fusion with 3 — 4 pts.
alkaline carbonate: after treating the fused mass with water, the solution contains
the add as alkaline sulphate, and the residue the base, as carbonate, which is now
sduble in hydrochloric add. In this and in all the following cases, the substance
most be powdered as findy as possible before fVision. The smphates of strontium,
caldnm, and lead are decomposed (the first not completdy), by cugestion with a solu-
tion of sodic carbonate : sulphate of caldum is somewhat soluble in water.

2. Siliea and tHieates, — ^When heated before the blowpipe with microcosmic salt,
they swim undissolved in the fused bead. They are rendered soluble by fosion with
S— h( ptsL alkaline carbonate (or hydrate of barium), treatment with hydrochloric add,
and evaooration with frwe add, when the silica remains insoluble ; or by treatment
with faydiofluaric and sulphuric adds.

3. Fluorides (fluorspar, &c)— When gently heated with concentrated sulphurio
add, they evolve hvdrofluoric add, which corrodes glass : if silica be present, fluoride
of silidum is evolved, which gives a predpitate on contact with water. They are
denoimposed by fridon with 4 pto. alkaline carbonate, with addition of dlica if neces-

4. Mumma or Muamnatea.^Thej sive a blue infiisible mass when heated with
eobalt-eolution. They are rendered sduble by fudon with 3 — 4 pts. add sulphate of

p 4

216 ANALYSIS-QUALITATIVE.

6, Chromie oxide (cbrome-iion-ore). — ^It giyes a green l>6ad in both flamei vHh
borax or microcosmic Bait Chrome-iron-^re in deoompoeed b^ snoceMiTO tuion viih
acid sulphate of potassiiun, and with alkaline carbonate and nitre.

6. Binoxide of tin, and AnHmonie anhydride, — Thej are colonred yeDov bj nl-
phide of ammonium, and dissolved by digestion in excess of the reagent : when bested
on charcoal with sodie carbonate, they yield, the first a malleable, the second a Irittlfl,
metallic globule. They are rendered soluble in adds by fiision with 3— 4 pts. alUiiM
carbonate.

7. Tantalic, tungetie, iHaniCt and oolwnbous anhydrides. — ^They give with inim-
oosmie salt a blue, violet, or (in presence of iron) a blood-red, bead : with one and
hydrochloric acid, a coloured solution. They are r^idered solubU by fbsion vith 6 pti.
acid sulphate of potassium.

8. Chloride, bromide, iodide, ofeilver ; JSulphidee of molybdenum, lead, ^— CUonde,
bromide, and iodide of silver, are soluble in cyanide of potassium : when heated on ebtf*
ooal with sodic carbonate, they yield metallic silver. Insoluble sn^hides prs off
sulphurous anhydride when heated : sulphide of molybdenum gives a yeIlDwiu*gnai
bead with microsmic salt, and is converted by roasting into mo^bdie anhydride^ which
gives a blue colour with sine and hydrochloric acid.

9. Metals (osmide of iridium, or residues of platinxmi-ores). — ^The insoluble nb-
stance has metallic lustre, or is a black powder, not affected by ignition. It is rendarad
soluble by mixture with, chloride of calcium and ignition in a stream of chlorine; or
by fbsion with potash and chlorate of potassium.

10. Carbon, — ^The insoluble substance is black (as diamond, colourless) : it du-
appears when strongly ignited in an open platinum crucible, or before the bbw^oe.
It detonates when fioisea with nitre, forming carbonate of potassium; and julds
carbonic anhydride when i^ited with oxide of copper.

If the preliminaiy examination furnishes no distinct idea as to the natiiie of tbe
insoluble substance, it must be ftised with four times its weisht of carbonates of po(i»-
slum and sodium, the fiised mass exhausted with water, and tiie residue treated vith
hydrochloric acid. If the substance contains any easily reducible metal (azMni^
antimony, tin, lead, bismuth, &c) it must not be fosed in a platinum cnidUe.

III. QualiiaHvs Analysis of Solutions.

The first stens to be taken in the qualitative analysis of solutions axe to asBertvD
whether the solution is neutral, acid, or alkaline to test paper ; and whether it oontuDi
any non-volatile constituents. For the latter purpose^ a small portion of it is cue'
fully evaporated on platinum-foil : when, if non-volatile compounds are present •
residue is left which does not disappear when strongly heated, and should besaboiitted
to the preliminary examination alx>ve described.

These precautions are of course unneoessair when the solution has been vuidol^
the analyst Inmselfl as described in Section IL : but they should never be neglected
when the substance to be examined is already in the liquid form, since, if careAi%
performed, they may enable him to conclude at once as to the presence or absence of
whole groups of bodies. Thus it is evident that a solution whi(A, after earefid enfo-
ration, leaves no fixed residue, cannot contain any non-volatile metallic salts. A
solution neutral to test-paper can generally contain only salts of the alkaline or alkaliBe-
earthy metals, since the salts of most other metals have an add reacKon. An olhAsi
solution (in which no non-volatile organic compounds are present), cannot contain vm
metals wnose salts are insoluble in alkaline liquids : if the alkaline reaction be eaitfod
by the presence of an alkaline carbonate, the presence of ihe alkaline-earthy m^
is impossible. Jf, however, non-volatile oiganic compounds are present, an aBoliiif
solution may contain salts of copper or sesquisalts of iron, as well as sach oxidtfi
cyanides, sulphides, &c., as are soluble in cyanide of potassium or alkaline solpbi^
The presence of ceortain acids implies the absence of certain metals, and viee verw:
thus the same add solution cannot contain sulphuric add and barium, hydrocklon^
add uid silver, &c Silver need not be looked for in an alloy soluble in hydioehlooe
add, nor gold, antimony, tin. Sec in one soluble in nitric add.

It is advisable, when possible, to examine for adds and metals in separate portioBi
of the solution.

a. Examination for Metals,

The systematic course of examination for metals which is now almost ezelofiTeif
employed, depends upon the behaviour of metallic salts in solution towards the foUo**
ing general reacents : hydrochloric acid, hydrosulphurio acid, sulphide of ammonisii^
and carbonate of ammonium. It will be observed that all these reagents are rolatue''
so that in their application no substance is introduced into a solution which cano^

ANALYSIS— INORGANIC. 217

W ranored hj simple eleTation of temperature. Their application depends npon
tlie different solability of metallic chlorides and snlphides, and of the carbonates of
the alkaline-earthj and aftaline metals. By means of these general reagents, as
ve hsTe alieadj observed, the metals are diyided into certain groups, which aro
meeaanb^ eliminated from the solution nnder examination; bj which proceeding
tlie detection of each indiTidoal member of each group is considerably ndlitated.
The foDovibg are the groups into which the metallic elements are thus divided :

«. Metils whose ehloridet are insoluble, or difScnlUy soluble in water or dilute acids.
Tlieae are lead, silyer, and mercuiy (the last as sub-salts). These metals are not gene-
nDy daased in a group bj themaelyes, but are included in the group next following,
to ^ueh thej also oelong^

A Group 1. — Metals whose ttdphides are insoluble in water or in dilute acids.
TIm^ ire all precipitated from their slightlj acid solution hj hydros ulphuric
aeid. They are ftother diyided into two subdiyisioos according to the bdiayiour of
thdr ndphides to sulpbide of ammonium.

BubdiimonJ. — ^Metals whose sulphides possets add properties. Their sulphides
aie sohUe in aftaline sulphides (sulphides of ammonium, potassium, or sodium),
fanioff therewith soluble sulpho-salts, which are generally analogous to the oxygen
nlti of tiie same metals, oxygen being replaced by sulphur. They are arsenic, anti-
mony, tin, gold, platanum, iridium, selenium, teUuzium, molybdenum, wolfram,

8»ibdHimon B.— Metals whose sulphides do not possess acid properties, not com-
hinmg with alkaline sulphides, and so bein^ insoluble therein. Aey are lead, silver,
mcRoxy, bismuth, copper, cadmium, palladium, rhodium, osmium, ruthenium. (Sul-
phide of mereuiT is soluble in sulphide of potassium or sodium : sulphide of copper is
Bomevbat aoluble in sulphide of ammonium.)

7. Qtoa^ 2. — Metals which are not precipitated by hydrosulphurie add, but which
are peeipitated by sulphide of ammonium, m>m acid solutions. This group
ilso » fiirther subtuvided.

AfUtewoM jL — Metals which are predpitated as sulphides. They are nickel,
eolaH, mimganese, iron, uranium, zinc Th&x sulphides are insoluble in water, but
adable in dilute adds, with evolution of hydrosulphurie add: hence they are not
pnopitited at all hy hydrosulphurie add m>m acid solutions, and not completely
from nsDtnl solutiona. They are however completely predpitated from an acid solu-
tion bj sulphide of amimonium, the add being neutralised by the ammonia contained
in it

StAdimskm B. — ^Metals which are predpitated as hydraUs, They are aluminium,
ghidnum or beryUiuzn, zirconium, thorium, yttrium, erbium, terbium, cerium, lan-
thanum, did^mium : titanium, tantalum, columbium, chromium. (The first ten metals
in this sabdiTision ar<e known as meials of the earths^ or earthy metals). They do not
eomfaiie with sulphur in the wet way, and so are not predpitated by hydrosulphuzio
icid under any drennostances. Their hydrates, however, bemg insoluble in water, are
pncipitated from thfur neutral or add solutions by sulphide of ammonium, the add
DTviiidi they were held in solution being neutraUseid by the ammonia of the reagent,
voile hydrosolphuric add escapes.

Oertain eompounda of the earthy and alkaline-earthy metals with non-volatile adds
(pbosphates, iwUt^Mi^ borates, &c.), beina soluble in dilute adds and insoluble in
vater, are similariy piedpitated hj sulphi& of ammonium.

S. Otoi^ 3.— Mietals whose sviphides and hydraUs are soluble in water ; which,
tiurefoie, are not predpitated by hydrosulpuhric add or sulphide of ammonium from
uj lofaition. This group induces the alluUine-earthy and atkaUne metals. They are
wther subdivided acooraing to their behaviour to carbonate of ammonium in presence

of ddoride of Mwmnni-nnn

Subdinsum JL — Metals which are piedpitated by carbonate of ammonium,
lliej are barium, strontium, caldum. Their normal carbonates are insoluble in water

or Uk chloride of ftmynnniiiTn.

Suhdtmsum B, — ^Metals which are not precipitated by carbonate of ammonium.
^Rieyaremagnedum, potasdum, sodium, lithium, ammonium. Carbonate of magne-
nnn is insoluble in water, soluble in chloride of ammonium : the carbonates of the other
fmr metals (alkaline metals), are soluUe in water. The different solubility of their
plMphiteB affords a means for the forther detection of the metals of this suodividon.

In the usual dassification, the alkaline-earthy metals rbarium, strontium, caldum,
■■gMsium) constitute Group 8 : and Group 4 comprises tne alkaline metals.

The following table exhibits in a compendious form the behaviour of all tha
nttali to the guieral reagents aboye enumerated.

ANALYSIS — DTOEGANIC.

Behaviour of Metallic Solutions with Hydrochloric Acid,

HydrosulphtiTio Acid.

M«Uli which ITS pn-
eipiutad u eiioriJeM
from thair usntnJ at
uid uUlioiit b; ^jl'

dneUorie aeid.*

Uetali which uv pnci^tatud u cnlphidca from thdr
hjdnchloric add loliilian bj ^fJretBfyitirie add.

MeliltvliaMnlk

dueediaiatai
•olntioa I^ If'

Lead (putnlly), whiles
ciyitilliiie, lolable in
hot water, predpiUtBd
these* hf inlphDiii!

BUvn, whila, curdy,
•olnbls in Mnmotiu,
precipitated thence by

Hxtrnxj u nbtalt,

whits, fiuelf-diiided,
biackeoed br am-

&AtU« im tulpkidt of

Ararale (jellow).
Antincn^ (orange),
nn* (bnwn or jellow).
0«ld \fbi^

[««»))"'""■

XolfbduilUB+ (brown).
[Btknllllll] (red-jellow).

[T«Unriaiii] (bluk).

Imolubh

jCbUd:).

SOvar

LMdf

Capptr

Oadmisn (jellew).
Kmath (hrown).
[Palladlnm] % \
[Oamlnm] I (hiack-

[ShodiuB] I brown).
[KntlianlaBi] )

viA KlTv K wfdte wvAa,
nuM-] lolnbla lu niter.

hrdr^kiriii (or nlbtiO llS^

■n MlaHeTgndS^ ef

* Vennr u DrotoHlt ie
PtedD. whUa Iff a BUU hj-
Soin^ hU( Uluk br »-

SrtMJsris.'s

aCHtJOMttOU.

int oiiiiUdM or in tu

mntr to we— el

Tin netala cndowd thai [ ] oia tctj lare, n

AMYLENR 209

Bfantljr absorbed, and the amylene is gradnany converted into a pasty mass of minute
oyrtals, which may be pnrifLed by washing with cold alcohol, reciystaLlisation &om
boiling ether and drying in Tacno over smphuric add. It gare byanalysis, 37 '26
per cent C, 6-61 H, and 17*66 N ; the £»nnula requiring 37*09 0, 618 H, and 17*28 N.

The oompoand may also be obtained, though less advantageoosly, by passing yaponr
of amylene mixed with air into fnming nitric add. It is remarkable as affording the
first esample of the direct combination of nitryl, (NO'), with an or^mic radicle.

Heated Vr itself in a dry tube, it decomposes at about 96^ C, giving off nitrons an-
hydride, N*U', and nitrons add, HNO', and lea'nng a heavy liqnid apparently containing
niteate of amyl. Heated with quick lime, it gives off an aromatic body, probably con-
sisting of oxide of amylene. (Guthrie^ Ghem. Soc Qo. J. xiii 46, 129.)

OxmJi or AmumB, (C^H**)''.0, a volatile liqnid, isomeric with valeric aldehyde.
It boils at 95^ C Has a pleasant ethereal odour, and a rough taste. Specific gravity
in tbe liquid state, 0*8244 at 0^ 0. Yapour-density by experiment 2*982, by (^cula-
tion (2 voL) ■■ 2*806. It bums easily, with a yellow flame. It is insoluble in water,
and is not converted into amylene-glycol when heated with water in a sealed tube.
It dissolves in alcohol, in ether, and in a mixture of the two. It mixes with aeids. It
unites with an^ydrotu or crystaUisahU fiitrie acid at a higher temperature, but the
combination is attended with partial decompodtion, (A. Bauer. Compt; rend,
li.600.) r- r N

Axxxsmi WITH BunPBXjR iJXD Chlobikb :

1. Diehhroeulpkide of Amylene, 0^»«SC1«, or C^5>»5*CP.— Protochloride of sul-
phur (SCI') is Drought into a flask surrounded with ice and an excess of amylene
added very gradually. The excess of amylene is evaporated off, — ^the residue digested
and washed with water, dissolved in ether, filtered, and evaporated. It is a non-volatile
liquid, having a pungent odour, insoluble in water, soluble in ether and alcohoL
Specific gravity, 1*149 at 12^ C. Distilled with excess of alcoholic caustic potash, it
yields amylene, disulphide o/fusyl (en's), and other products.

2. IHsulpkoehhride of Amylene, CH^'SCl, or C^^H^S^CL—On treating disulphide
€i chlorine (SCI), with excess of amylene, and evaporating the latter, a transparent
yellow, non-Tolatile liquid, of faint and nauseous odour is obtained, having the above
compodtion. It is obtained pure by digestion with water, solution in ether, filtration,
and evaporation. Specific gravity, 1*149 at 12° C. Soluble in ether, absolute alcohol,
and snmbide of carbon. (Guthrie, Chem. Soc. Qu. J. xii. 112.)

Djaoiphochloride of amylene treated with chlorine, gives off hydrochloric add, and
is converted into a non-volatile liquid, of specific gravify 1*406 at 16° C, miscible with
ether, insoluble in water, but soluble in hot alcohol. This liquid gave bv analysis
mnnbezs agreeing approximatdy with the formula, 0*WCl*8, which may be that of
Mtromdpkide ofirichloranwlene, C^\IPC^),SCS, or tha^t of sulphide of tetrachloramyl,
a\B?Cf)8. (Gathrie^ Chem. Soc. Qa. J. xiii. 43.)

AXTUERB WITH SOLFHUB AND OxTOEN:

Disuljphoxide of Amylene, O*B}*^0. — ^Prepared by digesting the disulphochloride in
alcohohc solution with protoxide of lead, till all the chlorine is combined, dissolving in
ether, filtering and evi^porating. Specific gravity, 1*054 at 13° C. Non-volatile, yellow,
or almost colourless. Soluble in ether and alcohol, insoluble in water.

Bydrate of Ditulphoxide of Amylene, Q^B^S'O.ffO, — ^Disulphochloride of amylene is
heated in alcoholic solution for some hours, in a current of ammonia ; the liquid is then
poured off from the chloride of ammonium formed, and heated for some hours in a
sealed tube to 100° C. with alcoholic ammonia ; the excess of alcohol is driven off
is a water-bath ; the residue treated with water ; and the oil which Is thereby pre-
cipitated is washed with water. Yellow liquid of meaty odour. Somewhat soluble
in hot water, soluble in alcohol and ether. Non-volatUe. Specific griavity 1*049 at
8®. (Guthrie, Chem. Soc Qtt J. x* 120.)— F. G. and H. W.

U C^H^O*. or C»*J2"0'.— This add is contained, together
trith eardol, in the pericarps of the cashew nut (Anacardiwn ocoidentale). The pericarps
are extracted with ether, wluch dissolves out both the anacardic add and the caidoi ;
the ether is distilled ofi^ and the reddue, after being washed wilh water to firee it &om
tannin, is dissolved in 15 of 20 times its weight of alcohol* This alcoholic solution is
digested with reeentiy predpitated oxide of kad, which removes the anacardic add in
the form of an insoluble lead-salt The lead-salt is suspended in water, and decom-
posed by sulphide of ammonium, and from the solution of anacardate of ammonium,
obtained after the removal of the sulphide of load by filtration, the anacardic add is
h*berated by the addition of sulphuric add. After repeated purification by solution in
alcohol, oonvernon into a leacUsalt, and decompodtion of this salt by hydrosul-
phuric add, the add is obtained as a white crystalline mass, which mdts at 26° C. It
Vol. L P

220 ANALYSIS — INORGANIC.

If we suppose the case of a solution oontaiuiug all the metals, it is ohvions that, hj
the successiye application of each of these general reagents, we shall sepaiate, fint) W
hydrochloric acid, those metals whose chlorides are insoluble ; secondly, by hydrosBl-
phuric acid, those metals whose sulphides are insoluble in dilute acids : thirdly, hj
sulphide of ammonium, those remaiaing metals whose sulphides or hydrates tn
insoluble in neutral or alkaline liquids ; and lastly, by carbonate of ammoniun, those
metals whose carbonates are insoluble : so that at last we haye only the alkaline
metals left in solution. In order, however, to effect the complete sepuation of each
group, the general reagents must be employed in the order aboTe stated: for solpbide
of ammonium would precipitate those metals whose sulphides are insoluble in ailnte
acids, as well as those whose sulphides are only insoluble in neutral or alkaline Hqnids;
and carbonate of ammonium, if employed before the other reagents, would pzedpitite
most of the metab*of Groups 1 and 2, their carbonates beinjg auo insoluUe.

The following rules, the importance of which will be obrious on the least zefleetion,
must also be strictly observed.

1. The mineral add employed to acidify the original solution (when it is not ilietdy
sufficiently acid), is either hydrochloric or nitric acid. Both are employed dilute, and
not in sufficient quantity to interfere with the formation of the sulphides of Gronp L
Hydrochloric is generally preferable to nitric add : for it serves as a general reag^t,
separating at once those metals which form insoluble chlorides. If nitric add be em-
ployed, these metals will be found in the predpitate by hydrosulphuric add.

2. The precipitation by each general reagent must be complete. To ensore thii^
the reagent must be added gradu^y, allowing the predpitate to subdde between eadi
addition, until no ftirther predpitate is produced. In the case of hydrosulphuric aod,
the predpitation is complete inien the solution, after agitation, still smells stronglj of
the gas. Gentle heat facilitates the separation of predpitates in almost every caML
Arsenic (as arsenic add), gold, platinum, iridium, rhodium, and molybdenum, are
predpitated very slowly by hydrosulphuric add. Tungsten and vananinm are not'
precipitated by hydrosulphuric add i^m an add solution : they are, however, iodnded
m Group 1, because their sulphides ^obtained by adding sulphide of ammoniim and
then hydrochloric add), are insoluble in adds, but soluble in sulphide of ammoninm.

3. JSach group, when precipitated, must be thoroughly freed by washing with water
from all members of the subsequent groups, which ma^r be contained in thesofaitioD.
This washine; is effected, according to circumstances, either on a filter, or by decan-
tation. If the predpitate contains any easily oxidable sulphides, a little hjdnaol-
phuric add must be added to the wash-water ^if the sulphide is insoluble in dQatd
adds, e. g, sulphide of copper), or a little sulphide of ammonium (if the sulphide is
soluble in dilute adds, e, g. sumhides of iron and manganese), in order to prevent the
partial oxidation of the sulphide by exposure to the air during the wasning of llie
precipitate. After the precipitation of each group, it is advisable to ascertain tb
presence or absence of any members of the succeeding groups, by carefully evaporating
on platinum-foil a moderate quantity of the filtrate; i^ after ignition, there is no
distinctly visible reddue, non-volatile substances need not be looked for fbrther. It
is obvious that, if these two precautions (complete precipitation and thorough washing)
be neglected, metals belonging to one group are liable to be found among those of
another group ; and consequently, as the analysis proceeds, reactions will be obtuned
which will be the source of ^;reat perplexity to the unpractised analjrst

Eadi group of metals having been separated by the application of general reagents,
the presence or absence of each member of each group is ascertained by means of
special or diaracteristic reagents. It seldom happens that the number of elements
contained in any inorganic compound exceeds ten or twelve : and in most cases some
distinct idea of the nature of its principal constituents is afforded by the results of the
prdiminaiy examination. In metallic minerals and alloys, the heavy metals an
chiefly to be looked for : in silicates, the earthy, alkaline-earthy, and alkaline metal^
iron, and manganese. It frequently happens that important information may be
derived from t£e colour of a precipitate or of a solution. Thus solutions of aiqpnf^
chromic, molybdic, and vanadic salts, are blue or green ; those of nickd-salts, green;
those of ferrous-salts, light bluish-green ; those of chromates, gold-salts, ferric- and
platinic-salts, yellow, wiui a red or brown tinge ; those of cobalt-salts, red, &c. Tfaesft
colours are not perceptible when the amount of metal present is very small, or when
they are masked by the presence of other metals, the colour of whose solutioDS ib
complementary to them.

In order to show the systematic method by which the memben of each group are
detected in presence of each other, we wiU now briefly go through the most important
groups mentioned in the table.

1. Precipitate produced hy hydrochlorie acid. — Chloride of lead is soluble in a la^
quantity of water, especially on boiling; chloride of silver, in ammonia; subdilorioe

ANALYSIS — INORGANIC.

221

cimeecarj is llackened hy ammonia. (The addition of either hydxoohloric or nitrio
acid may produce a precipitate in presence of such adds, hydrates, <granide8, sulphides
^tc^ as ai« soluble in a&aline liquids, but insoluble in water; or a precipitate of
solpbur, in presence of a polysalpmde or hyposulphite, or a white predpitate^ readily
sohiUe in more water, in a saturated solution of a barium>salt.)

2. PreeipttaU protktced by kydro9ulphurie acid,

a. Portion mdubU in aUkaiine tulpmdea. — Sulphide of arsenic is soluble in acid sul-
phite of potassium or in sesquicarbonate of ammonium, the salphides of antimony and
tin are soIl When the three sulphides are dissolTed in aqua-regia, and the solution is
introdueed into a Marsh's apparatus, antimony and arsenic are detected by the behaTiour
of their gaseous hydrogen-oompounds ; tin, aiter its separation by zinc, by its solubility
in hydrochloric add, and by the reaction of its solution with chloride of mercury.

& Bortiim iruolMein alkaline ndpkidet. — The predpitate is treated with nitric
acid : sulphide of mercoiy and sulphate of lead may remain undissoWed. In the
solution, lead is detected by sulphuric add; silrer, by hydrochloric add; bismuth by
its precipitation b^ ammonia, or hy water if no excess of add is present ; copper, by
the blue colour of its anmioniacal solution, or by fenocyanide of potasdum ; cadmium,
by the predpitation of its ammoniacal solution by hydrosulphuric add, after the addi-
tion of cyanide of potasdum.

3. PrteipUate produced by stdvhide ofammoniwn, — ^The predpitate is digested with
ezoees of caustic potash in the cold : chromium, zinc, aluminium, and gludnum are found
in the solution. Of the metals contained in the residue : cobalt, nickel, and manganese
form soluble double salts with ammonia, and so are not predpitated by it : iron, uranium,
the rarer earthy metals, and alkaline-earthy phosphates, oxalates, &c, are predpitated
by ammonia, eren in presence of chloride of ammonium. The hydrates of uranium and
the rarer earthy metals are readily soluble in carbonate of ammonium : ferric hydrate
is less sohibles,.and the alkaline-earthy salts are insoluble. Ferric salts are detected
by snlphocyanate or fenocyanide of potasdum ; the alkaline-earthy salts by appro-
prijite characteristic reagentSL

4. PrteipitaU produced by carbonate of ammonium* — The metals which compose
this group rbarium, strontium, caldum) are diHtingnished by the different solubiHty
of their sulphates, oxalates, chromates, &c. : and by the colours which they com-
mnnicate to the blowpipe flame, or to that of burning alcohoL

5. The solution, after the successiye application of the above general reagents,
cmo only contain magnedum and the alkaHne metals. Magnesium is detected by its
precipitation by phosphate of ammonium ; the alkaline metals by the colour which
thej impart to the blowpipe or alcohol flame, and by the different solubility of their

or diloroplatinates. Ammonium is always sought for in a separate portion of

the (Hig^nal solution : it ii detected by the evolution of ammonia when any of its salts

Edi

heated with a fixed alkali or alkaline earth.

Aypoaulpkite of sodium is decomposed by the salts of most of those metals which
precipitated by hydrosnlphuric add nom an acid solution, a metallic sulphide being
predpitated, it has been proposed to employ^ this compound as a general reagent
instead of hydrosulphuric add, and so to avoid the unpleasant smeu of the latter.
This sobstitution, however, has not as yet been generally adopted.

Carbonate of barium may also be employed as a general reagent When a solution
containing metallic salts is shaken up with excess of this salt, m the cold :

Are predphated.
Tin.
Gold.
Iridium.
Bhodiunu
PalladiunL
Platinum.

Ooppeor.

Bismuth.

Gadmium.

-Altfui'iiiilimj

Manganese \

Iron ^ las sesquisalts.

Uranium j

Chromium, as sescjuisalt, or as chromic

Titaninm,as titanic add.

Are DOC predpitated.
Silver.
Lead.
Iron
Nickel
Cobalt
Manganese ,
Zinc.
Cerium.
Yttrium.
Gludnum.
Magnedunu
Caldum.
Barium.
Strontium,
acid. Ammonium.
Lithium.
Sodium.
Potassiom.

as protoealta.

222 ANALYSIS — INORGANIC.

' Mercniy, plAtmiun, pAUadinm, rhodium, iridiuxn, and gold set precipitated by*
carbonate of barinm only when they are present as oxygennmltfl, not when preient as
chloridefl, &C Anauc, antimonic, phosphoric, aelenic, and aulphnrie acxda ar^ BOft
precipitated "bj carbonate of barinm nntil the aolntiona of their salts have beea
addtuated with nitric or hydrochloric acid. Carbonate of barinm is not mnch wed m
a general reagent ; it is however emplored with advantage for the s^Muataon of the
metals which are precipitated by sulphide of anmioninm, since it precipitatee com-
pletely those which are present as sest^uisalts, while the protosalts remain in SQlntion.
When, in the course of a systematic qualitative analysis, one or more membea of
the different groups have been recognised as constituents of the subetanee under ex-
amination, by means of the reactions above enumerated, the results must be oonfinned
by certain special reactions, which will be detailed at length in the articles devoted to
the several elements,

b. ExaminalionforJjsids.

The qualitative detection of acids, ii, on the whole, more difficult than that of metds ;
still, with due care, it may be accomplished with great precision. In most cases, the
preliminaiy examination, as well as the nature of tiie metals already found* give iiif<^
mation as to what acids should especially be looked for. The knowlet&e of the
solubility of different salts, and of the reactions of their aqueous solutions with
vegetable colours, is of the greatest importanoe in this examination. By heatang the
substance either alone or with concentnted sulphuric acid, the presence or absence of
organUs and ifoUUile inorgamo acids is at once ascertained, these acids either vdati*
lising undecomposed, or vielding volatile products of decomposition. For this pur-
pose, a small portion of the dry substance is heated in a test>tube (not to boiline) with
8 to 4 times its volume of concentrated sulphuric acid; when, in the case of afl adda
which are either volatile without decomposition, or are decomposed by sulphuric acid
at a high temperature, gases or va^uis are evolved, (he properties of whirh, in most
cases, indicate the nature of the acids present

1. Non-'VoUitiU acide : whose compounds evolve no vapours when heated with sul-
phuric add, the mixture not being blackened — Silidc, Boric^ Phosphoric, Sulpfaioie,
iodic, Arsenic, Sdenic, Tungstic, Molybdic, Titanic acids.

2. Acid9 which evolve a eUowred gae^ the mixture not being blackened — Hydriodic,
Hydrobromic, Bromic, Chloric, HypochlorouS| Nitrous adds.

3. Aoide which evolve a colourlese aae, generaUg possesses an irritaUng smell
and an acid reaction^ the mixture not beine blackened — a. Volatile witi^out decoxa-
position: Hydrosulphuric^ Hydrochloric, Nitric, Acetic, Benzoic, Soccinic, Hydro-
floric adds. The gas evolved is not inflammable, except in the case of hydro-
sulphuric add — b. Decomposed — Cjranic, Chromic (evolves oxygen). Carbonic,
Sulphurous, Hyposolphurous, Polythiomc, Oxalic, Formic, Hydrocyanic, Sulphocyanic^
ados, Ferro- and Ferri-cyanides. In most of these cases, tne gas evolved is inflam-
mable.

4. NonrVolatUe organic acids: Tartaric, Bacemic, Citric, Halic, Tannic, Gallic,
Uric acids. The mixture is blackened, and carbonic and sulphurous anhydrides and
carbonic oxide are evolved.

The behaviour of a mixture of salts, when heated alone or with sulphuric acid, is
often different from, that of each individual salt under the same circumstances. Thus
a mixture of a nitrate or chlorate with a salt of an organic add, does not bladcen when
ignited, but commonly detonates : a chloride, in presence of a nitrate, when heated
with sulphuric add, evolves dilorine and red nitrous fumes ; in presence of a chromate,
red fiunes of chlorochromic add ; in a mixture of a sulphite and a nitrate, ddorate,
chromate, &c., the sulphurous add is converted into sulphuric add ; in a mixture of
a sulphide and a sulphite, the two adds decompose each other, sulphur being sepa-
rated, and the characteristic smell of each destroyed. Chloride and subchloride of
mercury, and chloride of tin are decomposed with difficulty, if at all, by sulphuric
acid.

From a solution containing volatile and non-volatile adds, the former maybe
separated by distillation with dilute sulphuric add.

The general iMgents usually employed in the examination for adds in the wet way,
are chloride or nitrate of barium ; chloride of caldum ; a mixture of sulphate of mag-
nesium, ammonia, and chloride of ammonium ; seequichloride of iron ; nitrate of silver;
and indigo-solution. By these reagents, the most important adds are divided into the
following groupsL

1. Acids which are precipitated by chloride of barium : —

a. from a solution addtuated with nitric or hydrochloric add — Sulphuric, Selenie,
Floosilidc adds.

ANALYSIS — INORGANIC. 22S

. &. Ram a nentnl aobdifm (the precipitate beiiig soluble in acids) ^- SiiIpliiuoiiB»
PlK]i|)hiorie, Carbonic, SiUcie, Hydroflnoric, Oxalic, Chromic, Boric, Tartaric, Citric,
AiMoion^ Anenie adds. The last five acids are not precipitated in presence of

1 Adds vhich are preeipitsted by chloride of calcium : —

a f^mm a neutral station only (the precipitate being soluble in acetic add) — Phos-
phflric^ Anenie, Boric^ Carbonic, Snlpbnroos, Tartaric, Citric adds, and Femx^anides.
k "Fnm a neutral ok acetic add soIittion---Siilphnric^ Hydxoflnonc^ Oxalic, Kacemic

5. Aodfl irhieh are pzedpitated by aulpJkats of magnenum^ in jfre»enee of ammonia
MdcUoridi ofammomum — Pbospbonc^ Arsenic^ Tartaric adds.

4. Adds vhieh are detected by Hsquiddofide of iron : —

a Are predpitated — Ferrocyanides (from a solution containing firee bydrodiloric
add): Phosphoric^ Arsenic, Tannic adds (from a neutral or acetic aad solution) : Boric,
Bencoc, Soodnic adds (iScom neutral solutions ouIt).

b^ An coloured — In presence of free hydrochloric add ; Ferricyanides (brown), Sul-
phocyinic add (red). In neutral solutions only : Acetic^ Formic, Sulphurous, Meconic
idda (rod): Gallic add (black).

6, Adds whieh axe predpitated by niiraU oftilver .* —

f. Fran neutral solutions only (predpitate being soluble in dilute nitric add) — >
Pliosphozie, P^^ro- and Meta-pbosphoiic, Arsenic, Arsenious, Chromic, Oxalic, Boric^
Taitaiic^ GitDC^ SaJphnrous, formic adds: Silide and Acetic adds from concentrated
Nhitioos.

& From add Mentions also (the predpitate being insoluble in dDnte nitric acid).
Hjdzoehlorie^ Hydxobromie^ Hydriodio, Hydrocyanic, Sulpho^yanie, Iodic, Hydro-
Bdpfannc adds, and Ferro- and f erri-cyanideSi

6. hH^o^wHion is decolorised, without the addition of an add, by free chlorine
and broimne ; by all the 03^gen-adds of dilbrine, when free, and by metallic hypo-
ehloriteB ; l^^ free nitric add, if not too dilute, b^ alkaline scdphides, and by caustic
alkilia On addition of sulphmnc add, and heatmg, by chlorates, bromates, iodates,
and nitrates. On addition of bydrodiloric add, and beating (chlorine being erolred),.
Vf an the foregoing compounds ; also Inr diromates, sdenates, tellurates, ranadi^es,
TnanganatcB, permanganates, ferrates, ana all peroxides.

In inrestigatinff the adds contained in a soluble compound, the first step is to as-
certain the behaTiour of the solution to vegetable colours. Wben, as is frequently the
caae^ a neutral solution is required, the solution, if add, is neutralised by ammonia :
if alkaline, \fy nitric add, or, if nitrate of silver be not employed as a reagent, by
hydrodiloric add. But, as manj of the heavy metals, as weU as some alkaline-earthy
salts, are pfedpitated when their solution is neutralised by ammonia, it is generally
necessaiy to remove from the solution all metals except the alkaline metals, before
pioeeeding to test lor adds ; in whidi process, the presence or* absence of metallic adds,
and of alkaUne-earthy phosphates, oxalates, &e. will be ascertained. When this is
not done, it is frequentfy necessaiy to substitute for the general reagents mentioned
abore^ the nitrate of the same base, since nitric add forms no insoluble salts : thus
mtnte, instead of chloride, of barium, must be emploved in solutions oontaininff lead,
dlTcr, or snbsalta of mercury. We have already mentioned cases in which the addition
of nitric or favdrochloric add to an alkaline solution will produce a predpitate. The
fitUowing adds are also predpitated by the mere addulation of their <Jkaline solutions :
Tungstie, Molybdic, Antunonic, Benzoic, tJric adds ; Boric and Silidc adds from con-
ccotnted solutions. Under the same circumstances, a predpitate of sulphur is produced
in pnaence of hyposulpburous add or polysulphides : of iooine, in a solution containing
an iodide and an iodate : of add tartrate of potasdum or ammonium, in a solution
containing the normal tartrates of these metals. The nature of the metals found in
a Bofaitjon win often imply the absence of one or more adds : generally speaking, a
neotial or add sohition containing one of the metals whose salts are used as general
nagenli for adds, need not be examined for any of those adds which are predpitated
Ij that metal. Tfans^ sulpburic or bydrodiloric acid need not be sought for in soluble
eoflBponnds omtaining barium or silver respectively. In order not to overlook Ibe
presenoe ef uncombined volatile organic acids, the add solution is neutralised with
csibonate of sodiimi, evaporated to diyness, and ignited : when the organic add, whidi, if
free, wodd have been volatilised nndeoompos^ is decomposed, with separation of
eaiboo.

Sahstaaces whidi are insoluble in water or adds are rendered soluble by one of the
methods already described, and the solution is examined for acids in the wet way. In-
sobUe compounds of the heavy metals are mostly decomposed by digestion with

224 ANALYSIS — INORGANIC.

Bulphide of ammonimn ; Bulphates of stiontiiim and ealcimn by digestion with cajbonate
of sodium : in both cases, the filtrate contains the acid, together with an eau^ess of the
decomposing agents while the metal is found in the residue. Insoluble salts of arganie
acids are decomposed hj boiling with an alkaline carbonate ; ferric salts of Tolatile
oiganic acids by digestion with ammonia ; in both cases, the filtrate contains an alkaHne
salt of the adoL eiulphides and all salts of the lower oxygen-acids of solphur, yield
sulphuric acid when digested with nitric acid, or any other oxidising agenL

The application of confirmatory tests is as necessary in the case of acida as in that
of metals.— F.T.O.

The methods of guantitativB inoraamo analysis cannot be included in one article.
The processes for the separation and quantitatiTe estimation of each element are de-
scribed in the article deyoted to that element. The analysis of ashes, soila, mineral-
waters, &c and Tolumettic analysis, are also described in separate artidea. We may
here howerer describe a method, of general application, which is found useful in many
cases, -viz.:

7%elndire€f method of Quantitative Analysis, — The usual method of de-
termining the quantities of the several constituents of a compound or mixture, is to
separate each of them in the form of a definite compound, whidi can be collected and
weighed, e, a. silver as chloride, barium as sulphate, &c, and calculate the weight of
the required constituent from the known com|>08ition of this compound. It aometiincs
happens however, that the complete separation of certain subetonces is -very diiBcQ]^
or even impossible, and in that case, recourse is had to a method of determinatiaa,
which depends on the general principle that any number of unknown quantities duj
be determined simultimeously, if we can find between them a numMr of relatiaDB
equal to that of the quantities themselves ; in other words, n unknown quantities may
be determined by means of n equations*

Suppose for example, we have a mixtnre, either solid or liquid, containing potassiDBi
and sodium, in the form of hydrates or carbonates. Take two equal portions of the
mixture (it is not necessary to know the weight of these portions), convert one poctioD
into chlorides, the other into sulphates, and weigh the two products. Let the som of
the weights of the chlorides be a, and that of the sulphates b : the unknown weigjbt
of potassium «, and that of sodium y; then from the known atomic weights of the
metals, their chlorides and sulphates, we have:

74-5

68-5

■"

whence the quantities x and y may be determined.

Another form in which .the indirect method may be applied to the detenninatioo of
two substances, is to bring them both together into a form in whidi they can be
weiffhed, «.^. as chlorides or sulphates, and determine the^uantity of chlorine or of
sulptiuric acid in the mixture ; thus, suppose a mixture of potash and soda to be eon-
verted into chlorides : let the sum of the weights of these chlorides be «, and let the
amount of chlorine in this mixture, determined as chloride of silver, be c ; then if « be
the quantity of potassium and y the quantity of sodium, we have the two equations:

Ka NaCl CI ^ CI ^^

k"* kt^"'' 2* •" ra^ -'^
^' 3"9-' + 2r^-'' 89~* + 2ry -*^

whence x and y may be found.

If three substances are to be determined, e. g. barium, strontium} and calcium, we
should of course require three equations, which, in the case supposed, might be obtained
bv weighing the three substances, first as carbonates, then as oxalates, then as sul-
phates. It is seldom, however, that the indirect method is applied to the determinatioa
of more than two substances.

A case in which this indirect method of anal^rsis is often applied, is to the d^er-
mination of a small quantity of bromine or iodine in presence of chlorine, as in the
analysis of mineral waters. The chlorine and bromine are precipitated by a solution
of silver, and the mixed chloride and bromide of silver is weigheoL It is tiien i^ted
in a stream of chlorine till all the bromine is expelled, and the resulting chloride ie
again weighed: let the diflference of the two weights be d' then, since chlorine and

ANALYSIS (ORGANIC> 225

bramiiie repbice one another in the proportion of their atomic weights, viz. as
Sd-dtoSO^vehaTe:

«'-«- "'■ m- Ik

whence Br — - Bt = d; g^— Br » </.

and Aerefore Br ^ 1*797 d.

The indirect method of analysis can only Be employed with advantage to ascertain
die lebtiTe quantities of subetances whose atomic weights differ considerably : with a
mixture of bodies of the same atomic weighty it cannot giro any definite result ; in
&et the two equations which it inTolyee become in that case identicaL

(OIBdAirac)* — ^The analysis of oiganic substances divides itself
like that of inoiganic bodieSf into qualitatiTe and quantitative. A further division is
tlso oonvenient, viz. into Elemewtary or Ultimate Analysis and Prosifnate analysis,
aooording as the object of the inquiry is to determine the ultimate elements, carbon,
hjdrogen, &c., of which Hie body is composed, or the proximate principles, such as
fogar, Etaich, fibrin, &c, in which those elements are grouped.

I. Elbksktabt OB Ultimatb Oboanio Analysis.

Oiganic bodies are composed of carbon, hydrogen, and oxygen, with or without
mtrogen, sometimes also associated with sulphur and phosphorus : these are all the
ekmeots that occur in natural organic compounds ; those which are artificially prepared
may contain any elements whatever.

The detection and estimation of these elements dc^nds essentially on the process
of GoKBUsnoiv. Wlien an organic compound is heated to redness in contact with free
oxjgen, or with a substance which gives up that element with fiEunlity, it is com-
pletely decomposed, its elements being separated either in the free state or in new
iuma of oombination.

Q^ultlattve Analjnrifc Chrbon and Hydrogen are detected by burning the
eompoond in a gUss tube in contact with oxide of copper or chromate of lead. The
eubon is then converted into carbonic add*, which if passed into baryta-water, forms
1 white precipitate of carbon of barium, and the hydrogen into water, which collects
in drope in a small cooled receiver attached to the combustion-tube, or, if in very small
quantity, may be rendered visible by causing the vapour to pass through a narrow
^an tobe lined with phorohoric anhydride, which if water is present, will be con-
verted into phosphoric add and dissolved. Carbon may also, in nearly all cases, be
detected by the black reddue which remains when the organic substance is burned in
the air, or ignited in a close vessel, or heated with strong sulphuric add ; very few
oiganic bodies contain suffident oxygen to bom away the carbon completely, even in
contact with the air. The black residue of carbonaceous matter may b« distinguished
from black substances of inorganic ori^, by burning slowly away when heated to
redaeea, and by its property of deflagrating with nitre and chlorate of potassium.

nitrogen in organic bodies is for the most part given off in the fr«e state when the
eompoand is burned with oxide of copper, but a surer mode of detecting it, especially
when in. small quantity, is to heat the substance in a test-tube with a considerable
excess of hydrate of potasdum or sodium. The carbon is then converted into car-
home add by the oxygen of the alkaline hydrate, while the whole or the greater
put of the hydrogen unites with the nitrogen to form ammonia, which may be detected
oy its odour, by its action on litmus paper, and by the white fumes which it produces
when a glass rod dipped in dilute hydrochloric acid is hdd over the mouth of the
tabe (see AmioifiA). A still more delicate test for nitrogen is the following, given by
I^osBugne. A portion of the organic compound is fused in a test-tube with a smaJl
piece Sl potasdum ; the mass is treated with water when cold ; and the liquid boiled
with protosnlphate of iron partially oxidised by contact with the air. If it be then
npertatorated with hydrochloric add, the presence of nitrogen will be indicated by
the fcmnation of a predpitate of Prussian blue, or in case of very minute quantities, by
ft bhiiah green colour being communicated to the solution.

ddorine in organic bodies is detected by igniting the compound with quick lime,
whetehj it is completely destroyed, the chlorine uniting with the calcium, in which
state ox combination it may be dissolved out by water, and the chlorine precipitated
by nitrate of silver. In some organic compounds which contain hydrochloric add
ready formed, viz. the hydrochlorates of the organic bases, the chlorine may be imme«
diatdy detected by nitrate of silver without this preliminary treatments

* Throogboat thU article, the term earbonie aa'd is used for CO*, in accordance with eatabllihed
w^e, liMti^ of the mora correct appdlaUoo carbonic tmkjfdride*

226 ANALYSIS (ORGANIC)

Bromine and Iodine may be detected hy similar treatment ; Fluorine in the same
manner as in inorcanic bodies.

Sulphur^ Phosphoruet and Arsenic, are detected by igniting the organic compomd
with a mixture of hydrate of potassium^ and nitre or chlorate of potassinm, vhereby
those elements are conTerted into sulphuric, phosphoric, and arsenic addi, the
presence of which may be demonstrated by reactions appropriate to each.

Metale occurring in oi^anic compounds, remain for tiie most in the form of oxides,
or in the metallic state when the organic matter is burnt. Mercuiy may be detected
m the ordinary way, by distillation with lime.

QuantitatlTe Analysts* The first quantitative analyses of organic bodies were
made by Gay-Lussac and Th^nard. The substance to be analysed was mixed with a
known weight of chlorate of potaeatUTn, and made up into small pellets, whidi were
dropped one by one through a stopcock of peculiar construction, into an iqvight ^bss
tube heated to redness, the gas thereby produced escaping by a lateral tube and bang
collected over mercury. The volume of gas was exactly measured, and the carbonic
acid absorbed by caustic potash. The remaining gas consisted either of pure oxygen,
or (in the case of azotised bodies) of a mixture of oxygen and nitrogen, the propo^
tions of which were determined eudiometrically (see Air ai^ysis of Gases). Knoving
then the weight of the substance burned, the weight of the chlorate of potaasium used,
and consequently the quantity of oxygen evolved, also the quantitv of carbonic add
produced, and of the oxygen remaining after its absorption, sufficient data were obtained
for calculating the amount of carbon, hydrogen, and oxygen in the substance analTsed:
for, the difference between the total quantity of oxyeen which had disappeared, and
that which was consumed in burning the carbon (this latter quantity bemg e^ual in
volume to the carbonic acid produced), gave the quantity which had unitea with the
hydrogen to form water, and thence the amount of hydrogen was calculated.

This process was a great step in chemical science, and yielded many important
results ; but it was difficult of execution, requiring great skill on the part of tlie
operator ; it was also inexact in the case of nitrogenous bodies, and totally inapplicable
to liquid or volatile compounds. Berzelius simplified it by mixing the chlorate of
potassium with common salt, thereby causing the combustion to go on gradually, and
rendering it possible to introduce the whole of the material at once. He also coueeted
and weighed the water produced, and thus greatly simplified the calculation.

Saussure and Prout burned the organic substance in an atmosphere of oj^gen.
Front's apparatus was so contrived that the substance was burnt in a measured vofome
of oxygen, and the volume of the gas remaining after combustion was compared with
the original volume. Now, since the volume of carbonic add produced by the com-
bustion of carbon is equal to that of the oxygen consumed, while that which unites
with the hydrosen to form water disappears lUtogether, it follows that if the oigank
substance contains oxygen and hydrogen exactly in the proportion to form water (as
in acetic acid, sugar, &c.), the volume of gas remaining after combustion will be equal
to that of the original oxygen : whereas if the proportion of hydrogen is greater (as in
alcohol and ether), the volume of gas will be diminished by the combustion ; and if
the proportion of hydrogen is less (as in oxalic acid), the volume of gas will be in-
creased. Hence, by absorbing the carbonic acid with potash and measuring the
residual gas, sufficient data were obtained for Aftlpulafing the quantities of carbon,
hydrogen, and oxygen.

The method now universally adopted for the estimation of carbon and hydrogen in
organic compounds, consists in burning the compound with a large excess of oxide of
copper or chromate of lead, and determining the quantities of carbonic acid and water
produced by the combustion, not by measure but by weight, the water being absorbed
by chloride of calcium, and the carbonic acid by potash. The use of oxide of copper
was first introduced by Gay-Lussac and afterwards adopted by Ure ; but it is to Liebig
that we are indebted for those modifications of the process which have brought it to
its present state of simplicity and exactness.

The process, as now performed, requires the following materials and apparatus.

OxuU of Copper, — ^I^pared by dissolving copper in nitric acid, evaporating to dzy-
ness, and calcining the residual nitrate in a crucible at a low red heat. As thus
prepared, it is a dense, soft black powder, which rapidly absorbs water £nom the air
even before it is quite oold. If, however, it be very strongly heated, it aggregates
into dense hard lumps, which, when broken into small pieces and sifted from tiie finer
powder, yield an oxide well adapted for the combustion of volatile liquids. Oxide of
copper may also be prepared by igniting copper turnings in a muffle. The oxide thus
obtained is much harder and less hygroscopic than that prepared from the nitrate,
but it is not so easily mixed with an organic substance in the state of fine powder.
Oxide of copper must always be heated to low redness immediately before use.

Chromate of LeacU — ^Prepared by precipitating a solution of acetate of lead with hi-

ELEMENTARY OR ULTIMATE. 227

dtronute of potasdnm, fusing the washed and dried precipitate in a crucible, and
pahensing it in an iron mortar ; it is then obtained in the form of a yellow-browB
poirder. It is but rery slightly hygroscopic ; but to ensure its complete diyness, it
Bhoald be fsnerred in stoppered bottles and heated oyer a lamp just before it is used.

MddUe Copper, — Used in the analysis of bodies containing nitrogen. The most
comrenient form is that of fine copper turnings, or thin foil rolled up into a spiral. As
the Burfuse, especially of the turnings, is seldom dean, the metal should first be heated
in t current of air, to destroy any organic matter adhering to it^ then pressed
into a combustion-tube, and heated in a current of diy hydrogen gas to reduce the
oodde prerioosh' formed, the heat beine continued as long as vapour of water continues
to be giren o% and \h» stream of hydrogen afterwards kept up till the metal is cold.
By this treatment, the surfiice becomes covered with finely divided copper, which is
Toy hygroscopic and must therefore be strongly heated over a lamp before use.
Hoely mrided copper reduced by hydrogen from ihA oxide, is not applicable, being
Inuid to decompose carbonic acid at a r^ heat.

ComlmtUon-tHbes of hard glass. — They must be capable of sustaining a strong red
bat without melting or even softening to such a degree as to be blown out by the
pnasme of the evolved gases. The best are made of the hard Bohemian glsss (silica!^
of caldom and potaasium), which may now be procured without difficulty. Glass
C(aitaining lead is utterly unfit for the purpose. When the temperature required for
a comboBtion is very high, the tube should be protected by wrapping it in copper foil
or brass wire-gauze, to prevent it from bending if it becomes softened by the heat.

The length and diameter of tube required vary according to the substance to be
burnt For the combustion of ordinary solids, tubes of half an inch internal diameter,
and 18 inches long, are well adapted : for solids containing very little carbon, a diameter
of A of an inch is snfiicient: for liquids, it is necessary to use tubes ^ of an inch
viae and 20 or 30 indies long, the length being greater as the liquid is more volatile.
The nse of tubes of larger dimensions than the particular case requires, is not to be
RcomBiended, as it involves waste of oxide of copper and increases the unavoidable
enoTB of the operation.

The tubes, t^er being thoroughly deansed and dried, are drawn out into an inclined
luA, and sealed at one end,
while the other end is cut as Fig, 8.

evenly is possible with a ^

file, and afterwards made / J

■Booth at the edges by care-
fid heating in the blowpipe
flame. T^b best mode of
sealing is to take a tube of
doable the length required,
soften it in the middle by

means of a powerful blow- f

pipe ibime, then draw it out I

m the manner shown in ^. 8,

and apply the point of the flame for an instant at the middle of the neck a, so

as to divide and seal it. By this means, two tubes of the required shape are made

at once.

CUoride of calcium tubes, — The chloride of ealdum for absorbing the water gcne-
nted in the oombostion, is usually contained in a bulb-tube of the form shown in
fy. 9. The end a passes through a perforated

flotk fitting into the combustion-tube, and Fiff, 9.

the end 6 is fitted with a cork and narrow
glass tube, which is connected with the potash-
apparatas by means of a flexible tube of caout-
chouc Small plugs of ootton-wool are placed
>t c, d^ to keep the chloride of ealdum in its place. The cork d should be covered
vith sealing wax, so that it may not vaiy in weight by loss or absorption of atmo-
■phericmoisture.

Another form of this apparatus presenting some advantages is the U-tube {fig. 10)
haring at the end nearest to the combustion-tube, a small test-tube, f , which serves to
BoQect the greater port of the water, so that the chloride of ealdum does not get so
madi wetted, and may be used several times without renewal Chloride of calcium
tabes are sometimes also made in the form of a U-tube (fig. 11), having two bulbs, the one
>t the extremity of the arm of the tube bdng fllled with chloride of ealdum, and the
YP!^ being empty to receive the greater part of the water. This form of tube
u note aqpeotiye than that last dcscnbed (Jig, 10), and does not appear to possess
vtj advantage over it.

223

ANALYSIS (ORGANIC)

The tJ-tnbe must always be used in preference to tlie straiglit tobe {fig. 8\
when the combustion is made in a stream of oxygen gas ; because the cmrent of gu
being then rather strong, is apt to cany the yapour of water through the stnught
tube so quickly that a portion of it escapes imcondensedf whereas the U-tabe
detains it longer, and is more likely to ensure complete absorption.

Fiff. 10.

Fig. U.

Fig. 12.

The chloride of calcium should be in the spongy state in which it is obtaiDed Ij
drying at about 200° C. The fused chloride is not so good for the purpose, becaiue it
often contains free lime, which absorbs carbonic acid as well as water.

Potash-btUbs. — The solution of caustic potash
which absorbs the carbonic acid, is contused b
a liebig's bulb-apparatus (fig. 12), the form of
which is so contrived as to keep the bubbles of gas
in contact with the solution for a considerable tune,
without using a long column of liquid. The laige
bulb a, is connected with the chloride-of-caldim
tube, the other extremity of the apparatus being
left open. The solution of potash should have i
density of about 1*27. If a weaker ley be used,
the carbonic acid will not be completely absorbed,
and stronger ley is apt to froth, and in that case
a portion of it is sure to be forced out at the open
end of the apparatus, thereby annihilating the re-
sult of the experiment. To fill the bulbs, the potash
solution is poured into a small beaker or enable,
and drawn into the apparatus by means of a ediII
suction-tube (Jig. 13), attached to one endbymems
of a perforated cork. The quantity of liquid introduced should be sufficient to nearir
fill the three lower bulbs, not more : the apparatus thus filled weighs from 40 to 60

grammes. Before weighing, it must be careftilly wiped on the
outside; and the inside of the tube, by which the liquid ha*
entered, must bo dried by means of a thin roll of filtering paper.
Corks. — The connection between the combustion-tube and the
chloride of calcium tube, is made by a perforated cork. The
greatest pains should be taken to select for the purpose good
corks, smooth, and free from flaws. They should \k softened l»y
beating or by pressure. Immediately before the combustion.
the cork must be thoroughly dried in an air-bath or sand-bath at a temperature a
little above 100° C. : too great a heat must be avoided, as it renders the cork brittle
Caoutchouc-tubes. — The chloride-of-calcium tube is connected with the potash-
apparatus by a flexible tube of caoutchouc. These tubes are easily made by binding »
piece of sheet-caoutchouc over a glass rod or tube of the proper size, and cutting it
with a single stroke of a pair of scissors. Kthc edges be then pressed together, a pe>
fectly tight tube will be made. The connections are made air-tight by tying *iti
silk cord. Tubes of vulcanised caoutchouc, which may be purchased ready made, nay
also be used, and if of such a size "as to require some force to fit them to the tubes,
they make an air-tight joint without tying ; they must however always be preTionsly
digested with a moderately strong solution of potash, in order to remove the sulphur,
wUch is otherwise apt to get into the chloride of calcium tube and potash-apparatus.
Combustion-furnaces, — The combustion-tubes are heated either with charcoal or
with coal gas : formerly charcoal was the only fuel employed ; but ga^-famaces m

Fig. 13.

ELEMENTARY OR ULTIMATE.

229

mMming into ^ncral qm. Fiirn»c«s have also been constmdcd for burning spirit;
kt the high priw of that material in most oouatries renders its use reiy limited.

Tie Amoal'tartiace is made of sheet iioo, in the form of a trough (fy. 14), 22 to
U indies Ion);, and 3 incbM high. Ths bottom is 3 inches wide, wth narrow spei^
tuM about j an inch apart, which form h BOrt of gral« ; the sides of the {iimace are
indiwd ontnids. aod t| inches apart at top. To support the combustion-tube, pieces
itf Krong ib«et-imi of the form d (^. 15), ure liTStea to th« bottom of tbe fuiiuce at

iaUTTila; they are of exacfly equal heighti.witb their edges ground flat, and correspond
vitb the rooaii aperture in front of the furnace K. The liiriiacs is plaeed upon flat bncka,
» that bat little air can enter the grating unless the whale is purposely raised ; ths
dnnght can thus be r^ulated at pleasure. The heat produced by the eharCDal fire
is Tprj rtgntar, and may be raised to any degree required, higher indeed than the
heit eombustion-tubvs can bear ; on the other hand, Uie nse of cbanoil as fuel haa

Fig. IS. Fig.n.

Mcenuy to perform the combustions sa a i-oom apart irom the general laboratory.

F» these reasomi. it has long been consiiiered desirable to nse coal-gas as Che (iiel
fiv thi Forabustion process, and seTcral forms of iiintace bare been contrired for the
pnrpote. It is only lately, however, that the problem has received a satisfactory
Bohition. Tit in the pis furnace constructed by Dr. Hofmann, and described by him in
tlie Jouriud of the Chemical Society, vol. li. p. 30, whence the following details and
iliusbadons are l^en.

In Biing coal-gas as fuel, it is essential that the gas while baming be mixed with
air in nif^ent quantit; to ensure complete combustion and prevent smoking. This
is nsnillj eSecled by interposing a sheet of wire gauze between uie flame &nd the oriflcea
frmn whirh the gas issues. This contrivance was indeed adopted in a form of furnace
for organic analysis inventfd some years ago by Dr. Eofmuin, and has also been
adopted by others. But all furnaces thus constructed are very liable to get out of
order, in ronsequence of the speedy destruction of the wire gauze ; moreover, thej
do not ifibid enffident heat for many combustions : hence they have not come into
gcuenlnae.

Inthenewlbnnof gasfamace,tbe mixing of the gas with air is attained bycaasiog
it to issue Ihrongh a number of small orifices placed very close together. For this
purpose, ■ pemliu form of burner is used,
rxlied atnmpUTt {fig. 16). It consists of a
boUow cylinder of burnt clay, closed at top,
•fea at bottom, and having nnmerons per-
(Sratjons in the sidea. Those which are
used for the combo^on-t^imace, ore 3
inches high, { of an inch in eitemsl, and
\ internal diameter. The perforations, of
aboot the thickness of a pin, are made in
io*a, each cylinder having 10 rows of Ifi
Ikolfs eodi. From such a claj <rvlinder
loosely fixed upon an ordinair bats wing
bomer, ths stopcock of which has been
piopeity adjosted, the gaj boras with a
perfectly blue smokeless flame, which en-
velopea the cylinder and soon renders it i . I
iacaadcflcent. ^-- --^ *■ Horiionui cu p!p«-

Thedi«po«itioooftheaH>aralnsisshown ' iild^il^Mp '""

in fg. 17. Into a brass tube a, from 3 feet to S feet °a.,a^^^^°\ ""w**"
(iadialoDg, and 1 inch in diameter (shown in section >. l«w iiij bumrn. "*'*'
n the figure), which communicates at both ends with /■ ''vP'"""^,",'"'"^,-
the gas-main of the Uborstory, there are screwed &om Vii Cut "nm upporu *'
W to M Inbes A. These tubes, \ an inch wide and V^ '^a'il.™i£t?iw"'
7 inches high, are provided with stopcocks and carry u. cotb plus ct iri-dir.
bncket* e e, J an inch long, and | of an inch in diameter,
fcr the reeeptiaa of five ordinary hab'a wing burners (each consuming from 3 to 1

230 ASALTSIS (ORGANIC)

cnliiF f«t of gat per iioax, for a foli lominoiiB efiect) npoD vhich ore fizpJ a eotre-

epomUng number of clij bnmen. These dtj tinmen dddd. have the dimetuioDB
aboTC itatfd, eaieptiiig the middle one, vhich is onl; IJ iuchffl high and has 70 or
80 perforatioiM. It eerres M > mpport for the cornhnslion-tube /, whirh is thm
bedded in a chatinel of heaUd Kre-cluy. The sjBt«m of braclieb lying aide b; side,
acquires efficient itabilitj by a otrong iron frame gg, vhich rest) upon tiro Snn
nipporta hh, c^ caat-inni, &stened down by icrewa npon the foot-plate, ■ i, likeviae
of csst-iroii. The iron frame gg, haa moreoTer a grcxne for tha reception of
moTeable eide plates of fire-day it k. They are of the name height aa lie high
bonien, over which thej project about | of an inch, ineonaequenceof their reating npon
the IVame g .- Lutly, 1 1 are corering platra, likewise of &re-clay, vhich.jAre Bupporled
bj tha Bide plalea k k. ^'

The whole dispositioD of this E^iparatna wilt be best nndentood by toe pciTpective
Ttew giren in^, IS. In the &ont part, contignona to tho potash-apparatna, the side
platea and the corering platee are oiDit(«d, in order to show the diaposition of the
bunien. Doling the combustion, bowerer, all the bonen are inclosed, as exhibitea]
in the posteriar port of the apparatns.

Fig. 18.

The efficiency of the iiimace depends essentially upon the correct di8peeiti<m at
the gas jets. The moat appropriate apace between the sereial burners, is about J
inch. It is TeiT important for the attainment of a perfectly uniform temperMBTO
that the BeTeral braclieta bearing the bnmers ahould be ei^nidiataot. Their pontioD is
therefore specially secured hj eyerj bracket being fixed id an apertim fonoed in the
iron ftame gg. Jig. 17-

According to the length of the combustion-tube, from 8 to 10 stopcocks (under all
circnmatances the largest poaeible number) are opened at once at the conmiencemsit
of a combuation. If care haa been taken to regulate the amount of gaa, either by
the stopcocks in the horizontal gas pipe, or hy tboae in the acparate supply-tabea, tbs
lighted portion of the furnace will, in 10 or IS minutes, be in a state of perfect in-
caudeacence- After this it is only necessary to open the remainder of the stt^iccw^
in appropriate BUPcession, to inanre a alow and regularly progressing combustion. The
time required for the completion of an analysia Tsries &om 40 minutes Xo an hour,

The heat ohtainpd by this furnace Ls very regular ; and since it ia conrejcd to the
combuation-tube chiefly by radiation from the incaudescent maaa of aunoundine day
ereiT part of the tube is equally heated. The temperature which it is capable of
yielding i4 entirdy at the command of the opomtor. When atrained to ita full
power, It giTCS a heat equal to that of the strongest charcoal combustion-fDmace ; bat
by properly adjusting the stopcocks, it may 1» kept at any desired tempomture,
especially since it is only necessary to look into the channel, when, with a littla
practice, a correct idea of the temperature is rapidly obained from the colour of
the glowing cylinders. It deaerres, however, to be noticed that the apparatus
fiimiahes rather more heat than ia generally roqaired ; it ia preferable, therpfbrt^
under all circumstances, to protect thd combustion-tube by a metallic shield : for this
purpose ordinaty brass wire gauae may be convenieutly employed ; it is more easily
manipulated, and may be used longer than the thin copper or brass plate generKltj

Ona great

ELEMENTARY OE ULTIMATE,

tlw hol«fl in the bomen Derer become stopped ap^irith carbon. Voreorer, tbe cr

Hie gal ooDTOiiKil is yery mach Uiss than tbat of tbc thBTl^oal required to pmdoC'

Buneunonntof liefttingeffiKt. Dr. HofmiiDii has foandthat

a eombnstioii luting I hour, and reqniring the whole lengtb

of the ftmtace (M rows of bornerB), coDsomes from 80 to 90

nbie feet of gat. For a carbon determination, with 24 roTS

of bomers, which general]}' laats about 40 mindtcs, fiom

60 to 60 cubic feet are required, luid fbr a nitrogen deter-

minatton, 2d to 30 cubic feet. In laboratories vhere manj

combastioaa are made, the aaviiig of fuel voon coven tbe

original awt of the fiimace.

Tfae expense of Iho apparahia and the consumption of
gis^ naj be diminished bj reducing the number of
revs of bomen from S to 3, aa iihown in Jig. 19. The
heat giren by such a furoace is of cDurae not so great as
'* ~ ~ ' d bjthela^erone, but it issaffidentfor nearly

SereTBl other fi»vis of gas ftmace far organic analysis
b*Te also been pri^naed. One of these invented by Babo, which is much used in the
German laboislories, is represented in Jig, 26, page 235.

Pbefisatich of the Substahcb fob Amaltsts.

Before praeeeding to determiae the proportion of the elements in ao oi^imic Com-
pound, it is necpsaary to ensure that the substance is in a perfectly pure and definite
state. It is bat teldom that the procesaea of ultimate analysis can be adran-
tageonsly applied tn complex orgHnic mixtures ; only indeed when the proportion of
s Binf^ dement is to be determined for commercial purposea, as in the ralnation of
articles of fbod or of manures by the quantity of nitrogen which they contain.

In solids, qnifimnify and regulari^ of stmctnre, whether ciyslalline or otherwise, is
in many caaea the best tent of purity : in snch cases, examination by the microscope
is often of gnat aervice. Conatsncy of melling-point is also a test of the purity of
nupy anbataneea, especially of fiitty bodies. The purification of solids is geneAlly
eflMcd by reoystalHaation from solution, or from the fused state, or in the ease i^
Tolatile bodies, by suhlimatioii. In houids, the chief test of pnritr is constancy of
boiling point, and purification is effected chiefly by fractional distillation. InoUcoset
a small qnanti^ of the substance must be burnt npoQ platinum foil, in order to ascer-
tain whether it contains any inorganic matter; if the organic body is pure, it will bum
wilhont midue. If inorganic matter is present in considerable qaantitf, or if it forms
an eaaential part of the compound, sa in the salts of organic adds, its quonti^ must be
exactly determined by bonung a weighed portion of the compound.

P^irther, it is necessary before proceeding to the process of combustion, to free the
compound from hygroscopic water. For this purpose, a weighed qnantity of the sub-
stance ia heated for some time in a water-bath at 100°, and then weighed again ; if it
has loat weight, it is again heated and again weighed : and these operations are re-
peated till two successive weighings, between which the subiitance baa been heated,
give the same rt«ult. The substance may then be considered dry.

Bodies which cannot bear a temperature of 100° C. without demmpoaitioD, may be
dried by placing them over a largo dish containing strong sulphuric acid, and covering
the whole arrangement with a bell-jsr; the desiccation is greatly accelerated by
fdacing the whole apparatus on the plate of the air-pump, and exhausting the air.

The same methods may be applied to determine the amount of chemit^y combined
Titer which exists in many compounds, the water of crystallisation of salts, for ex-
ample^ Many bodies, however, retain their water with too great force to be over-
come by the means just mEutioned. Snch snbstances may bo dehydrated by enclosing
them in a test-tube immersed in a water Or oil-bath, while a cnrrent of dry air ia
drawn throng the tube by means of an o^trator. In some cases even this is not sufB-
dent u") ^^^ desiccation can only be effected bj heating the substance in a tube
from whidi the air is exhausted by an air-pump, then introducing dry air, eibaast-
again, and so on, till llie sobatanca ceases to lose weight. (See Evafosatioh and
twl)

It ia oftm, however, difficult to determine how much of the oxygen and hydrogen
exiatins in a compound exists in the form of water: for many substances, before they
me off all the water that can be eliminated by the methods above described, bq;in to
decompoae and form new compounds. In snch cases, the process of orgunic amtlysia
must be applied to the compound in the hydrated state, and the quantity of watcv
estimated as nearly as possible by the phenomena which the substance exhibits when
heated, or by its chemical reactions.

232 ANALYSIS (ORGANIC)

VolatilB liquids ar« dehydraled by iesving them for some I ,._

lamps of fused chloride of calcium and then dUtiliinj^ the chloride of calcium bcii^
hawerer preTiotisly removed, aa it might, when beatad, give up wme of Uie n>a
which it haa absorbed.

The Bubatance haring been brought to the proper State of poii^ and diynen, mij
now be Bubjected to the combustion process.

EsmuTioH OP CiEDOM Airo Htdhoobm.

in Solidt Hot ooniaining Nitrogen. — The Bubslance being thoccmghlj di}: nd ii
the state of fine powder, about 03 grm. (or 6 grainB) ia weighed out in a small UA-
tube, or between two watch-glaases, the weighing being made eiact to the IgaOi of i
milligrammo (or '001 of a grain). The vessel and it* contents an wsghed li^alia,
and after the sabBtanee has been removed, the Teseel, with the amidl qmntilj k
matter adhering (o it ia again weighed. This weight deducted from the fonoer pia
the quantity of substance used in the eiperiment. The combustion-tnbe afhr baif
cleaosed, if necesaair, ia made veiy hot in the sand-bath, and a long bUss tube beia{
thrust into it^ the air is sucked out bo as to remove ever; trace, of moisloie.

The combuHtioQ may be made either with oiide ot copper or with chromate of W;
the latter being the more easily managed, on account of i\a possessing httle or h
hygroscopic tendencies, we shall describe its use in the first plaoe : — A qnantitj of (n
chromate (previoosl; fused and pnlverised) sufficient to fill the tube, is healed ma
a gas lamp till its colour changes to brown-red. When it has cooled, a amall qun-
titf ia poured Into the tube, sufficient to fill about au inch of its length, aad iboiitti>
thirda of the remainder is poured iat« a clean dry porcelain mortar. The mbituin b
be analysed is then added to It, and the two are carefallj mixed bj gentle tritnratiiiii.
The combustion-tube being then taken in the right band, and the mortar is tbe Ml
the mixture Is transferred to the tube by a, kind of screwing motion, the open end of
the lube being slightly inclined upwards after each addition, and the tube Ughtlj
tapped against the aide of the mortar to make the mixture descend. When na£^
the whole of the mixture has been thus introduced, a small quantity of freili due-
mate is poured into the mortar, triturated ao as to rinse it, and then transferred to tin
tube in the same manner. The remainder of the tube up to within an inch of Ifn
end is filled with pure chromate. The contents of the tnbe are then shaken bigeths
by a few gentle tape on the table, so as to leave a &ee passage throughout for tht
«TolTed gas. The nrraugemeiit of the nilxture in the tube is shown ia fig. 20, rtere

a represecta the pure chromate, b the mixture, c the rinsings^ and d the pun chrooiU
near the open end.

The talw is now laid in the combustion furnace, and the chloMde-of-caldmn tst«
and potash-bulbs are attached to it in the manner already described, the pctJiii-
bulbs resting on a fobbed cloth, and the outer bulb being slightly raised by pliciii; >
cork under the apparatus at r. Fi^. 2 1, represents t£e arrsagement for bnnuag
with charcoaL The disposition of the gas-furnace is shown in ^. 18, pige JM.

re commenMng the combustion, the apparatns must be carefully examined to
re its tightness. For this purpose, a hot coal is held for a short time wat tlit

ELEMENTARY OR ULTIMATE. 233

iiiiCTljon) (m) of the pofaali sppsniluB, bo M to rare^ the air and cause a few bubbles
to pim tluoDgb the liquid. TLe coal is then withdrawn, and thn apparntuB left M
itself for about tan ntinntes. If all Che joiDta aro air-tight, the liquid will dow riss
in the bnlb m to a hi^er level than in the Qater bulb, and will retain its position ;
bat if inj leak ocmrs, it will noon full down to its original lerel. Should this be the
Hae, the leakage is most probably in tbe coA which fits into the combustloa-tube, or
in tbe caentchouc connector. To remedy this inconveiuence without dels;, it is well
to ba pmided with two or three well dried perforated corka and a good stock of
caootcbooc connectOTs.

The tightness of the apparatus haTing been eatabliahed, the heat may now be
tpplinL The antetioi portioa of the tube containing the pure chroinat« is first
hatHl to redneas, bj l»iDg red-hot charcoal round it (or taming on the gas jets im-
■wdiatfly uder it^ The charcoal furnace is provided with a maveable screen g,
(Jig. i\\ to prerent the heat from extending too quickly along tlie tnbe. When the
ulerior portion is thoronghlj red-hot, the pure chromate of lead at the dosed end of
the lube mnit also be heated, to redness, in order to bum an; vapour that maj diffiisa
into that part of the tube, and to prevent its depositioa on the drawn oat point,
wbmoo it would afterwards be difBcult to remove (this precaution mOEt be taken it)
«verj combustion, bj whatever process). The fire ia alowlj extended towards tbe ^i^
ther eitremitv, each portion of the mixture being thoroughly burnt before the fire is
extended further. The combustion should be so regulated that the carbonic acid may
enter the potBah-bnlbe at a uniform rate, and in a BucceBsion of bubbles which may be
easily counted. If no nitn^en is present, these bubbles are, after a certain time,
completdj absorbed by the potash ; but when an azotised body is burnt, bubbles of
niCfogen pass through the potash-Bolution during the whole process.

When the tube has been heated to redness throughout, the heat must be rtused by
fiinntng the firo on the 1^^ and admitting air below by aligbtly raibing tbe furnace &om
tbe bricks. As sooc as the evolution ot gas begins to slacken, tbe cork is removed
bam under the potash-bulbs, and the apparatus brought into the horizontal position.
If the combustion has gone on well, the evolution of carbonic acid ceaaea all at once;
if, on the contrsry, tbe gas bubbles continue to pitss slowly at intervule for a long time
after the tube has been thoroughly ignited, we may be sure that tbe combustion is
imperfect, most probably in consequeuce of the mixture not having been snfBciently
intimate, and that the qnanti^ of carbon will be found deficient.

Aa soon as the evolution of gus ceases, the liquid begins to rise in the bulb m.
The coals must then be quii^y removed &om the end of the tube, and the point
broken off with a pair of nippers. If the passage through the tube is clear; the potasb-
■olntion immediately fulls to the same level in both bulbs : if it does notj there is a
stoppage in the tube, and no time must be lost in clearing it, by thnieting in a stout
iron wire from end to end ; otherwiae the potash -solution will be sucked up into the
chloride of calcium tube, and the result will be entirely destroyed. To complete the
eiperiment, it is now only necessary to draw a stream of airtbrongb the apparatus, by
^plying the suction-tube (fig. 13) to the extremity p, of the pota^ apparatus, so as to
draw the small portions of carbonic acid and aqueous vapour remaining in the tube
into the chloride of calcium tube and potash-bulbs. In doing this, however, a certain
[oecsQtian is necessary : for tbe broken end of the tube being surrounded with an
itmoophen of carbonic acid, a portion of tbia gas is likely to be drawn through the

e into the potash-solution, thereby making the proportion of carbon appear loo
it. To prevent this, a long glass tube open at both ends is placed over the end of

234

ANALYSIS (ORGANIC)

the eombustion-tabe, and supported in a slanting position, as in Jig. 22, wliile the air
10 being drawn through the apparatus. By this means, the air is <lrawn from a height
above the stratum of carbonic acid over the fomase. When the gas fomaoe is used,
this precaution is of course superfluous, as the flame can be extinguished at once.

Lastly, the chloride-of-calcium tube and the potash-bulbs are detached, left to cool
for about half an hour, and then weighed. The increase of weight of the potash-bolKi
gives the quantity of carbonic acid produced, and ^ of this is tiie quantity of caiboa
in the sul»)tance analysed. The increase of weight of the ehloride-of-calciiiiii tnbe
giyes the quantity of water produced, and \ of this is the amount of hydrogen. £nov*
ing then the quantities of carbon and hyorogen in a given quantity of the snbstance
analysed, it is easy to calculate the proportions of carbon and hydrogen in 100 pirti
If the quantities thus determined make up 100, the substance is a hydrocarbon ; if
there is a deficiency, and it is known that no nitrogen, sulphur, chlorine &c. is present,
the difference gives the percentage of oxygen. Examples of the calculation vill be
given further on.

Combustion with Oxide of Copper, — When the combustion is made with oxide of
copper instead of chromate of lead, particular precautions are required to prevent the
absorption of water during the mixing and filling of the tube. A quantity of the
oxide is heated to redness in a covered earthen crucible, and left to cool till it vill
no longer bum a cloth in which the crucible is held. It is then mixed in a hot mortar
with the substance to be analysed, and the mixture is arranged in the tube betveen
two columns of pure oxide of copper, exactly as described for chromate of le&d, tlie
whole operation being conducted as quickly as possible. Some substances, howeTer,
will not bear mixing with hot oxide of copper ; and even when this can bo done, the
oxide is sure to cool during the mixing sufficiently to cause an absorption of moistors
from the air : hence an excess of hydrogen in the result of the analysis. To obriate
this source of error, it is sometimes recommended to lay the tube, after filling, in «
trough of hot sand, and connect it with an air-pump, then introduce air dried bypass-
ing over chloride of calcium, exhaust again, and so on. This, however, is a trouble-
some complication of the process, A simpler method of preventing the absorption of

Fig,2Z.

Fig, 24.

Fig. 7.5.

^\/^^

water, is to pour the oxide of copper, while still hot, into a long-necked flask (fig. 23),
closed by a perforated cork in which a chloride-of-calcium tube is inserted, leaie
it to cool, and mix it with the organic substance in the combustion-tube itseUl
The neck of the flask must be a little wider than the combustion-tube, so that
the latter will just pass into it (fia. 24) : the oxide may then be transferred to the
tube without coming in contact with the air. A small quantity of the cooled oxide
is flrst introduced in this manner, then a portion of the organic substance is added,
and upon this a column of oxide about three inches long is poured in the same
manner as before. This portion of oxide is mixed with the organic substance by
stirring it with a dean iron rod {fig. 25), the extremity of which is bent into two
turns of a scrow^ and when it is thoroughly incorporated, the rest of the substance ifl
introduced, then another column of oxide of the same length as before, and the stirring
18 repeated. Lastly, the rest of the tube is filled with pure oxide, and the combustion
performed as above. This method of incorporation does not ensure so complete a mix-
ture of the substance with the oxide as trituration in a mortar; but it answ^ this
purpose suficiently well in most cases.

Oxide of copper is in many respects more convenient for use than chromate of lead,
and indeed is more generally used for the combustion of substances which bum with
facility. It is more easily prepared, and when partially reduced by the combustion
procesSi may be restored to its original state by moistening it with nitric acid, and

ELEMENTAEY OR ULTIMATE.

, it improves in thia rpspeot by ead
lepetilion of the treatment. Chromate of lead nmy also b« reoiidised b; digvettoi
mlh nitric acid and Babeeqaent fiisioii ; bat the piUTerisatioa of the timei maaa ia a
Ten^ Uboriona operation.

On the other hand, there are many cases in vbich the uae of cbromate of lead
nnsenta decided adrantases, viz. in the combaatioa of substances vhieh are verf rich
m carbon or difficult to bom, such as fatty bodies, coal, graphite, indigo, &c Such
bodicfl are nerer completely bnmed by oxide of copper, probably because, at the be^n-
oing of the combofltioii, they give off combostible gases, which partially reduce the
eopptf in the neighbonrbood of each particle, and leave behind a qiiantity of charcoal
DO limgec in contact with the oxide, and requiring an atmosphere of free oxygen to
bnni it. Nov chromato of lead fuses vhen the heat becomes strong, thus becoming
more iDtimately mixed with the combustible sabstance, and moreover gives off a
qnanti^ of free oi^gen, which eflectuflJly completes the eombnstion of the carbon.
Ita effioenoy may be still further increased by mixing it witb about -jf of its weight
of acid ehiomale of potosainm.

Organic aalta (tartrates, acetates, dec) of potassium, sodinm, barium, strontium, or
<ii]innni, if bomt with oxide of copper, also exhibit a considerable deficiency of carbon,
because the metal then remains in the tbnn of a carbooate. This source of error majr
be obviated liy adding to the Oxide of copper a qoantity of phosphate of rojiper or
oxide of antimony sufficient to decompose Uie carbonate ; or, better, by making the
eombnstion with chiomate of lead.

Comiuttion wilK Chridi of Copptr in a ttrmm of Oxygm. — The oiygec may either
be crolved from chlorate of potassium placed in the combustion-tabe, or in a veesel
connected with it ; or it may bo previously prepared and supplied fmm a gas-holder
connected with the tube.

He simplest way of proceeding ia to place at the closed end of the combustion -tube
about 1| inch of a mixture of 1 pL of cMorate of potassium (or better of perchlorale)
and 8 pta. oxide of copper, preciously heated over a lamp and introduced while hot ;
then half an inch of pure oxide of copper, then the mixtnre, and a column of pore
oxide as osnaL The combustion is corned on in the ordinal^ manner, until tlie tube
is ignited as &r as the pure oxide near the sealed end. Heat is then cautiously applied
to the mixture of oxide and chlorate, so aa lo evolve oxygen at a moderate rata.
The carbon ia thereby completely burned, and if the saprSy of oxygen is sufficient,
the reduced copper is reoiidued. After the gas has passed through the potash-solu-
tion for a few minntes without bein^ perceptibly absorbed, the bulbs and the chloride-
of-calcinm tube may be detached, without tireaking off the point ofthecombusllon-tube,
and air drawn through them to displace the free oxygen, which would otherwise in-
crease their weight

The stnam iS warm oxygen passing through the potash-solution is sure to carry
•way • certain quantity of vapour of water. To prevent this, a small tube containing
hnnpa of fnsed potash should be attached to the bulb apparatus. The apparatus
with this addition usually weighs between SO and 30 grammes.

In operating in the manner above described, there is, however, considerable danger
td the stream of oxyEen becoming too rapid, and thereby caning off the vapour faster
than it can be absoiwd by the solid potash.

It is betttr, therefore, to supply the oxygen &om a gas-holder. The combnstion-

M>e is open at both ends, and the end a, fiirthcatfrom the potoah-bnlbs and chloride-

o£<aldnm tuba is ooonected witb two gos-boldcrs (./^. SS), one filled with atmospherio

236 ANALYSIS (ORGANIC)

air, and the other with oxygen gas. The communication is made by means of A
T-tube provided with a cock, which renders it easy to connect either gas-holder with
the oombustion-tabe and shut off the other at the same time. The air and oxygen
before entering the combustion-tnbe, are made to pass through two U-tabes, one con-
taining pumice-stone soaked in sulphuric acid, to dry the gas, the other lumps of caustic
potash, to free it from carbonic acid. The combustion-tube may be heated either
„. ntr ^^^ S^ ^^ '^^^ charcoal (the figure represents a

Jfig, 11. Babo's gas apparatus), and themuxtnre may be disposed

■^ in the tube in the ordinary way. But instead of mix-
-y ing the substance with the oxide of copper, it is better

^ in many cases to place it by itself in a small boat of

platinum or porcelain h {fig. 27).

The combustion-tube is first filled to two-thirds of its length with oxide of copper,
which need not be previously ignited, the remaininjB^ third, nearest to the gas-holder
being left free to receive the boat. It is then laid in the furnace, and connected, in
the manner just described, with the gas-holder containing atmospheric air ; the oxide
of copper is heated to redness ; and a stream of dry air is passed through the tube so
as to remove every trace of moisture. The tube is then left to cool ; the boat con-
taining the substance is put into its place, a plug of recently ignited asbestos having
been previously introduced to prevent the oxide of copper from coming in contact with
it ; the chloride-of-calcium tube (U-shaped, see p. 228) and potash-bulbs are attached in
the usual manner, and the apparatus is connected with the gas-holder containing oxyg»i.
The oxide of copper is now once more heated to redness, and as soon as it is thoroughly
ignited, heat is very cautiously applied to the part of the tube containing the boat^ a
slow stream of oxygen being passed through the apparatus, sufficient to prevent any
backward passage of the evolved gases, but not to cause any free oxygen to pass throo^
the solution of potash. If the oxide of copper exhibits a red colour, arising frtnn
reduction, the heating of the substance in the boat must be dis(K)ntiQued till the copper
is reoxidised. When at length there is nothing left of the substance but black char-
coal, the heat may be increased and the stream of oxygen accelerated. In this manner
the combustion is soon completed ; and when the bubbles of gas appear to pass through
the potash without absorption, the process is continued in the same manner for a
few minutes longer, and the potash-bulbs and chloride-of-calcium tube are then de-
tached, after air has been passed through the apparatus for a little while to expel the
oxygen. Lastly, the stream of air is continued for a sufficient time to effect the com-
plete reoxidation of the copper, which is then ready for imother experiment without
further preparation.

After the tube has cooled, the boat is taken out and reweighed. If any inoiganie
matter remains in it, the quantity of this is at once ascertained if the weight of the
boat itself is previously known.

This method, when carefully conducted, ^Ves veiy exact results : it ensures tiie
complete combustion of the carbon, and obviates all danger of an excess of hydrogen
arising fcom. moisture in the oxide of copper. It likewise saves the trouble of igniting
the oxide of copper before the experiment, and afterwards treating it with nitric aci^
But to ensure a good result, especial care must be taken not to heat the substance in
the boat too suddenly ; otherwise combustible gases will be given off more quickly
than they can be burnt, and the analysis will be worthless.

Combustion of Liquids. — ^Volatile liquids are enclosed in small glass bulbs with
narrow necks {fig. 28). The bulb is first weighed and then filled with the liquid, in
the same manner as a thermometer tube, viz. by gently warming the
Fig. 28. bulb so as to rarefy the air, and dipping the neck into the liquid, so that
as the air cools, a small quantity of the liquid may be forced up by ex-
ternal pressure. The bulb is then again heated tiU the liquid boils, the
end of the neck immediately plunged again into the liquid, and Uie heat
removed. The vapour now condenses and leaves a vacuum, into which
the liquid is forced up so as to fiU the bulb and the greater part of the
neck. The neck is then sealed, and the bulb re-weighed. It is best to
use two bulbs, each containing about 400 milligrammes of liquid.

The analysis is made with oxide of copper : the coarse-grained variety
obtained by oxidising copper turnings in a muffle, or by breaking oxide
which has been hardened by strong ignition intp small lumps, and sifting
off the finer particles, is best adapted for the purpose, because it affords
free space for the passage of the vapours, whereas the fine-grained
oxide lies more compactly, and the greater part of the vapour possee
over the surface instead of finding its way between the particles. For
tlie same reason, chromate of lea'), which fuses into a mass, is not so well ada{>ted foe

ELEMENTARY OR ULTIMATE. 237

the oombostion of Tolatile liquids. The oxide of copper mnst be ignited in a cmciLIe
and left to cool completely in a corked flask (p. 234).

The oombnstion-tube should be at least 20 inches long, veiy Tolatile liquids
TequiriDg even a greater length. About an inch of the cold oxide is first poured in
through a wide-necked funnel ; one of the bulbs is then taken by the neck, a slight
9CTat<^ haying been previously made on it with a file ; it is thrust into the tube, bulb
downwards, the neck broken off at the scratch, and both bulb and neck dropt into the
tube. About three inches more oxide is then added, the other bulb introduced in the
same manner, and the tube filled up with oxide of copper. This oxide is first heated
to rednees, care being taken to proceed yery gradually, and when the charcoal furnace
is used, to protect the bulbs by a screen. As soon as the oxide is well ignited, a hot
eoal is approached to the nearest bulb, so as to volatilise a portion of the liquid,
especial care being taken not to drive it over too fast. When the first bulb is empty,
the heat is gradually extended ; the liquid in the second bulb is then distilled in the
same manner, and the combustion is finished in the ordinary way. As soon as the
distillation of the liquid commences, a few pieces of hot Charcot must be placed under
the point of the combustion-tube, to prevent the liquid from condensing there, as if
this occurs, considerable heat will be required to dislodge the liquid, and a sudden
boist of vapour is likely to take place.

The object of using two bulbs is to prevent too great a reduction of copper in the
neighbourhood of either of them ; when there is no longer any oxide close to the bulbs,
a deposition of carbon is apt to take place, and then a stream of air or oxygen is
required to bum it. Greville Williams, however, uses only one bulb, and drives all
the liquid, at the very commencement of the analysis, into a column of cold oxide of
eopper about four inches long. This portion is not directly heated till the end of the
analysis, tJie liquid being volatilised by the heat conducted by the oxide. Finally, a
stream of oxygen is passed through the tube to bum the deposited charcoaL Volatile
liquids cannot be burned in a continuous stream of oxygen, because an explosive mix-
tore WDold be formed.

For extremely volatile liquids, like aldehyde, a different plan is adopted. Such
liquids are enclosed in a bulb having the form of a small retort, the neck of which,
raeviously sealed, is inserted into the
hinder extremity of the combustion-tube, Fiff. 29.

which is drawn out and left open for the r

purpose, the connection being made air- f

tight by means of a caoutchouc tube. As '

soon as the oxide of copper is ignited, the

sealed end of the retort is broken off by

pressing it against the oombustion-tube,

and the liquid is volatilised by cautiously

applying the heat of the hand or of tepid water to the bulb. If the liquid is so volatile

as to boil at the temnerature of the room, the bulb must be immersed in ice, and the

evaporation regulated by removing the ice fi?om time to time, and replacing it as soon

as the liquid begins to boiL

Fixed oils are weighed in a short teat-tube, which is then dropped into the com-
bustion-tube,— a small quantity of oxide of copper having been first introduced, — and
by inclining the tube, the oil is made to spread itself over the sides for about half the
length, after which the tube is filled up with oxide of copper or chromate of lead.
Soft, easily fusible fats are treated in the same manner. Waxy bodies are weighed in
small lumps, then dropped into the combustion-tube, and spread over its surface by
fosion. Fatty and waxy bodies may also be placed in boats in the manner already
described (p. 236), and burnt with cl^omate of lead, or with oxide of copper in a stream
of oxygen.

Modification of the Comhuation-process in particular Cases:
a. In bodies containing Nitrogen. — ^When an azotised organic body is bumt^ the
greater part of the nitrogen is given off in the free state, together with the water
and carbonic acid; but a certain portion, var^ng according to the nature of the
substance and the manner in which the combustion takes place, is converted into nitric
oxide, or one of the higher oxides of nitrogen. Now, if either of these compounds is
fcrmed in the process of oiganic analysis, it will pass over with the carbonic acid, and
if not decomposed before it reaches the potash-ley, it will be absorbed by that liquid
and give rise to an error in the estimation of the carbon. Before, therefore, an organic
compound is subjected to the combustion process, it must be carefully examined for
nitrogen in the manner already described (p. 226), and if that element is found to be
present) the combustion must be made in such a manner as to ensure that the whole
of it shall be evolved in the firee state.

238 ANALYSIS (ORGANIC)

For fcliis purpose & long combustion-tube is taken, and after the mixtai« and \h»
pure oxide of copper have been introduced in the ordinary way, about flye inches of
copper-turnings, prepared as described at p. 227, are placed at the open extremity.
This metallic copper must be heated in a sand or air-bath just before it is iranted
and introduced into the tube while still hot, as its surface is yeiy hygtosoopic
The combustion is made in the ordinaiy way, the metallic copper being however first
he-ated to redness, and kept in a state of strong ignition during the whole procefls.
The nitrogen is then eyolved in the £:ee state, and passes through the potasn-ley in
bubbles.

The combustion must be made with oxide of copper alone : if chiomate of lead ii
used, or a continuous stream of oxygen passed through the tube, the quantity of nitric
oxide formed is too large to be e£fectually decomposed, eyen by a very long column of
red-hot copper. Oxygen may, howeyer, be passed through the tube at the end of the
combustion, being eyolyed for that purpose from chlorate of potassium (p. 235). The
more slowly the combustion is conducted, the smaller will be the quantity of nitzic
oxide formed.

$. In bodies containing Sulphur. — ^When organic bodies containing snlphitr are
burned with oxide of copper, the sulphur is conyerted into sulphurous acid, which, if
not intercepted, will pass into the potash-solution together with the carbonic acid.
This may be preyented, by interposing between the chloride-of-calcium and potash-
apparatus, a tube containing peroxidp of lead : the sulphur will then be retamed in
the form of sulphate of leao. It is better howeyer to make the combustion ^th
chromate of lead, placing in the front part of the tube a rather long colunm of pure
chromate, which is heated only to dull redness : the sulphur wijl then be retained in the
combustion-tube.

y. In bodies containina Chlorine. — ^When chlorinated organic compounds are horat
with oxide of copper, chloride of copper is formed, which being yolatUe, passes OTcr
into the chloride of calcium tube, and renders the detennination of the hydrogen
inexact. This source of error may be completely avoided by burning with chromate
of lead, the chlorine then fbrming chloride of lead, whidi is not yolatile even at a red
heat.

Similarly with bodies containing bromine and iodine.

9. Jn bodies containing Inorganic Matter. — If an organic body, when burnt in the
air, leayes a residue which gires off carbonic acid on being treated with acids, its
analysis by combustion with oxide of copper will not ciye exact results, because a part
of tiie carbonic acid will be retained in the ash, instead of passing into the potash-bulbs.
This is particularly tlie case with the organic salts of potassium, sodium, boriom,
strontium, and calcium. If the residue were in all cases a neutral carbonate, its
quantity might be determined and the amount of carbonic acid contained in it added
to that which is absorbed in the potash apparatus. But this is not the case, the
composition of the residue being yariable, and depending on a Toriety of ciicnmstanoes.

In such cases, the complete eyolution of carbonic acid may be ensured in two ways:
either by burning with oxide of copper, and mixing the organic substances with ignited
phosphate of copper, boric anhydride, or oxide of antimony ; or better, by burning with
chromate of lead, the alkaline carbonate being then completely decomposed by the
chromic acid. — ^When these organic salts are burnt in a platinum boat, in a stream of
oxygen (p. 231), the residue may be weighed, the quantity of carbonic add in it
determined in the ordinary way, and added to that absorbed by the potash.

Amount of Error in the Estimation of Carbon and Hydrogen,— ^^^'^
methods above described, the carbon may be determined within 0*2 per cent The
error is generally in defect^ in consequence of imperfect combustion ; sometimes, how-
eyer, it IS in excess, especially in azotised bodies.

The hydrogen may be determined yet more nearly, viz. within 0*1 per cent The
error is usually in excess, arising from absorption of water from, the air during the
mixing of the substance with oxide of copper. But if this be avoided, by making the
mixture in the tube itself, or if the combustion be made with chromate of lead, only
a very slight excess of hydrogen need be apprehended. When the substance is burnt
in the platinum boat (p. 231), the hydrogen sometimes comes out a little below the
theoretical quantity.

EsnUATION OF OXTGBN.

Oinrgen is usually estimated by difference, after all the other elements of the com-
pound have been determined directly. In compounds containing only carbon, hydro-
gen, and oxygen, this method is sufficiently accurate : for, the error of the carbon being
generally in defect, and tibat of the hydrogen in excess, the two nearly compensate
each other ; but when chlorine, sulphur, and other elements are present, the ezrois

ELEMENTARY OR ULTIMATE. 239

upon all these being usually in the same direction, tie. in defect, the amount of oirgen
determined by difierenoe is likeJy to be mnch too great. A good method of determndog
oxygen directly is therefore a desideratum, more especially as it would afford a check
on uie estimation of the other elements.

A method of efiecting this determination has been given byBaumhauer (Ann.
Ch. Pharm. ze. 228), and applied in one or two eases. A combustion-tube open at
both ends is fitted up in the ordinary way for the determination of carbon and hydro-
gen, and the two ends of the apparatus are placed in connection with graduated glass
tubesi, the one at the hinder extremity of the combustion-tube being filled with oxygen,
80 that, wh»i tile combustion is finished, a stream of oxygen may be passed through
the tube and re-oxidise the reduced copper. The apparatus is then left to cool, the
quantity of gas in the two tubes is read oS, and compiled with the quantity before the
experiment, due regard being paid to corrections for temperature and pressure. The
difference gives the cjuanfity of oxygen taken up by the reduced copper. Now, the

Suantities of carbonic acid and water produced by the combustion having been
etermined, ike amount of oxygen in this earbonie acid and loater^ diminished by the
quantity of oxygen which has aisappearedf gives the quantity of oxygen contained in
the substance analysed: thus, if the amount of oxygen in the carbonic acid and water
were 10, and the quantity of oxygen absorbed by the copper were 7, the amount of
OK^en contained in the substance would be 3.

jBaumhaner gives two analyses (of oxalic acid and oxalate of lead), in which the
oxygen was detennined by tins method with great exactness. As, however, the total
ToKime of gas in the apparatus (the eombustion-tube, potash-bulbs, &c.) is not known,
but only the difference of volume before and after the experiment, the corrections for
pamcore and temperature cannot be made with accuracy. For exact results, it is
therefore necessary that the pressure and temperature at the beginning and end of the
experiment should be nearly the same.

Estimation of Nrntoosir.

The quantity of nitrogen in an organic compound is determined, either by burning
the compound with oxide of copper and metallic copper in the manner already described,
and measuring the quantity of nitrogen evolved, — or by igniting the com^und with
soda-lime, whereby the nitirogen is evolved in the form of ammonia, absorbing the
ammonia by hydrochloric add and precipitating hj dichloride of platinum.

When the mtrogen is evolved in the free state, it maybe estimated in two ways, vis.
eomparativdy, that is, by comparison with the quantity of carbon in the compound,
previously detennined; or absolutely^ that is, by direct measurement of the whole
quantity evolved.

Idebs^s Comparative method. — A mixture of the substance (which need not be
weigfaedX with the usual proportion of oxide of copper, is introduced into a combustion-
tube of such a length as to be half filled by it^ the remainder of the tube being filled

Fig. 30.

up, half with oxide of copper, half with copper turnings. To the mouth of the
eombustion-tube is fitted a gas-delivery tube, which passes into a trough of mercury
and is made flexible by the insertion of a tube of caoutchouc.

A screen being placed between the mixture and the pure oxide of copper, the oxide
and the metallic copper are first raised to a strong rea heat; a secona screen is then
placed at t^e back part of the tube, about an inch from the sealed end, and the portion
of mixture at that end is ignited, so that the products of the combustion may drive
the atmospheric air out of the tube. The combustion of the rest of the mixture is
then carried on in the ordinary wa^, the heat being gradually extended towards the
hinder part of the tube, and the mixture of carbonic acid and nitrogen evolved is
collected in a number of graduated jars, half an inch in diameter, and twelve or
thirteen inches long. These jars must be accurately divided into equal parts of the
same value in all ; but the absolute value of the divisions may be any whatever.

As soon as one of the tubes is about three-fourths filled with gas, it should be lifted
up and the rest of the mercury allowed to run out^ so that its place may be supplied

240

ANALYSIS (ORGANIC)

Fig. 31.

with atmospheric air. The object of this is to ascertain whether the gas is free from
nitric oxide ; if only -^^ pt. of that gas is present, reddish fumes of peroxide of
nitrogen will be produced, and if not seen immediately, will become yisible on look-
ing along the axis of the tube. If any red or yellow colour is perceptible, another jar
must be examined in the same manner, and so on till perfectly colourless gas is
obtained. When about six jars haye been filled with the gaseous mixture, the pzocess
may be stopped, nothing being gained by carrying it to the end.

The jars filled with gas are now to be transferred one by one to a tall par {Jig. 31),
containing mercury, and the proportion of carbonic acid and nitro-
gen in each of them determined, by first bringing the mercury to
Qie same leyel inside and out» and reading off the yolume of the
gaseous mixture, then absorbing the carbonic acid by a strong
solution of caustic potash, intr^uced by means of the curv«a
pipette ▲, and reading off the yolume of nitrogen left If tlie
combustion has been properly conducted, the proportion of car-
bonic acid and nitrogen should be the some in all the jars.

Now, a molecule of anhydrous carbonic add CO', containing 1 atom
of carbon [ *» 12], occupies the same yolume as a molecule (or doable
atom) of nitrogen, NN [2 . 14 — 28]. If therefore, the yolnmes of
carbonic acid and nitrogen in the gaseous mixture are to one
another as m : 1, it follows that the number of carbon-atoms is
to the number of nitrogen-atoms as m : 2, and oonsoquently tlie
weight of the carbon in the compound is that of the nitrogen as
m X 12 : 2 x 14, or as 3 m : 7 ; so that, if the percentage of
carbon (c) bepreyiously found, the percentage of nitrogen (n) will be
given by the equation : ^

Fig, 32.

For example, caffeine, which contains 49*48 per cent of carbon, is
found by the process just described to yield carbonic acid and
nitrogen in the proportion by yolume of 4 : 1 ; the percentage of
7
nitrogen in caffeine is therefore 7. 49*48 = 28-89.

This comparative method of estimation yields perfectly satisfactory results for all
compounds in which the proportion of nitrogen to carbon is not less than 1 : 8, pro-
yided the combustion is conducted in such a manner as to ayoid the evolution of nitric
oxide. The risk of error from this source is less, the mart intimately the organic sub-
stance is mixed vnth the oxide of coppery and the mare slowly the combustion, is per-
formed. This rule applies to all combustions of azotised bodies.

Liebig^s comparative method has been variously modified by different ehemist?.
Bunsen has contrived a form of apparatus by which it may be carried out writli
accuracy, even when the proportion of nitrogen is very sm^ and with not more
than a few centigrammes of substance. This method consists in burning the sab-
stance with oxide of copper and metallic copper in a sealed tube filled
with hydrogen, and analysing the resulting mixture of carbonic acid and
nitrogen in a carefully graduated eudiometer.

A tube of thick Bohemian glass, about 15 inches long, and J of an
inch internal diameter, is drawn out at one end in the form of a oone,
as shown at a {Jig. 32), and the part a is then heated in the blowpipe
flame till it is contracted and the glass very much thickened. A mix-
ture of 3 to 5 centigrammes of the organic substance, with 5 gm». of
oxide of copper, is now introduced into the tube, together with a fe"«r
copper turnings, and the other end of the tube is drawn out and thickened
in the same manner as the first The tube is then connected at one end
with a hydrogen -apparatus, jig. 33 (a being the generating vessel, and
B a receiver containing sulphuric acid to dry the gas), and at the otber
with an exhausting syringe. The hydrogc^ after passing through the
tube, escapes by the cock p.

As soon as all the air is expelled, the cock p is closed, the cork of tbe
generating vessel loosened, the caoutchouc tube c tightly tied, the tnbe
partially exhausted by a stroke of the pump, and the cock s immediately closed. The
tube is now sealed at d and h with the blowpipe flame, the sealing being much facilitated,
by the partial exhaustion. The next step of the process is to heat the tube to rednesa,
having flrst enclosed it in a mould of gypsum, to prevent it from being blown out by
the expansion of the enclosed gases. For this purpose, the two halves of a cylin-
drical mould of iron plate, shown in Jig. 34, are filled with gypsum paste mixed

1,1

ELEMENTAKT OB ULTIMATE. 241

wHh > tew eo»-hairB, and w aoon u tha plaster begins to set, the tnba ia kid
in one half of the monld, the other half put on, and the two flrmlv vedged
tggether. The appamtas is then heated to lor ledneas for an hoar, the tube t^ea
oat ^len qnita cold, *iid one of the sealed ends broken off midei a gndnated jar fhll

ednaKmy, so that the mixture of nrbonie add andnltrogeD in the tube may ^ss np
to Om iap of the jar. The gaseoos miitnie is moistened bj passing up a drop iMt
VBtcr, then accnntelj meaaared, with doe Tegard to coirections for pleasure and
temparatara, and afterwards &eed from carbonic add by thrusting up into it a ball of

ftased potash, fixed at the end of an iron wire (see Akaltsis of GubsV the ball being
first moistened by breathing on it. This ball is then withdravn, and another ball of
irj potash inttridaceil for the purpose of drying the gas, after irhich the raidnal
nitnigeii is mBasnred. The proportion of carbon and nitrogen is then calculated in the
■aanneT already described.

Other modiflcalioDB of Liehig's method hare been introduced by Dr. Haxvell
Simpson (Chem. Soc Qu. J. -ri. 290), by Marohand (J. pr. Cheia, iL 177) and
by Bottlieb (Ann, Ch, fbarm. Imnii. 2*1).

i. Attotnle nuiiifd. — The organic compound is burnt with oxide of copper, as before,
and tb^ vbole quantity of rarbonic acid and nitrogen coUe<:ted, In the fonn originiUly
given to this proceas by Liebig, the carbonic lu^d and nitrogen were collected in a
eraduated jar, containing air and standing over mercury, the jjas-deliTery tube being
beat BO as to pass np through the meroui; into the air in the jar. The Tolume of air

ToL. I. R

242

ANALYSIS (ORGANIC)

'WBB eareftilly noted before the ezpeEunent, also the Toltune of air and gas when the
combostion was finialied and the apparatoB had been left to cool, the obaerred Tolunes
being in each cam redaoed to the standard pressure and temperature; the increase
gave the Yolume of carbonic acid and nitn^n produced by the combustioD. The
Tolume of carbonic acid was then calculated from a preTious determination of the
carbon, and this, deducted from the yolume of the mixed gases, gave the quantity of
nitrogen by yolume, from which the weight was calculated. For example, 0*1 grm.
caffeine burnt in this manner yields 114*06 cub. cent of gas at 09 0. and 28* bar.
The same quantity burnt in the ordinary way yields 0*181 grm. carbomc acid, oor-
responding to 91*09 cub. cent at 0° 0. and 28 inches of the barometer : consequently 0*1
grm. caffeine yields 114*06— 91*09 » 22*85 cub. cent nitrogen gas — 28*86 per cent by
weight

The process in this form is liable to numerous sonroes of error. In the first place,
the necessary limits to the the size of ^ jars standing aver mercnir, restricU the
quantity of substance burnt to 1 or 2 decigrammes ; and with this small quantity the
exTors of observation and manipulation beur too great a proportion to the whole togire
even a good approximation to the truth, unless the proportion of nitxogen is nUier
large. Very considerable errors may arise from the alteration in the oimensioDs of
the tube, likely to result from softening by heat, and from the consumption of a
portion of the oxygen of the air in the tube during the combustion. (For tie detaiU
of the proceaSt see Handtoorterbuch d. ChemU, 2** Aufl. i 873.)

To remove these sources of error, the process has beeji modified bv Bomaa and
others, so as to make the result independent of the yolume of air in the appazatis.
This is effected by replacing the air by another gas, which can afterwards be remored
by absorption, and sometimes also by exhausting with the air-pump.

In Dumas's process, the air is removed from the combustion-tttbe, partly by ex-
haustion with the air-pump, and partly by a stream of carbonic acid gas evolved from
carbonate of copper placed at the sealed end of the tube. The combostion is then
performed ; the carbonic acid and nitrogen eyolyed bj it are collected in a graduated
jar standing oyer mercury, and containing also solution of potash, which absorbs the
carbonic acid ; and, when the combustion is finished, the carbonate of copper ia agiia
heated, so as to eyolye carbonic acid, and sweep all the remaining nitrogen into the
jar. The yolume of nitrogen is then obseryod, with due regard to pressure and
temperature.

This process giyes accurate results ; but it is troublesome, and requires rather
complicated apparatus. A simpler form of it is now generally used, in which the
exhaustion with the air-pump is dispensed with by the use of a substance vfaich
evolves carbonic acid more abundantly than carbonate of copper. This simpliflcatira
is due to Melsens. (Ann. Ch. Pharm. Ix. 116.)

At the sealed end of a combustion-tube 30 inches long, is placed a layer, 6 inches loDgi
of acid carbonate of sodium, a b (fig» 85) ; then oxide of copper, h c; then the mixture

of the organic substance with oxide
Fig, 36.

d'.

jar, standin
The tube

of copper, od; then strong ig-
nited oxide of copper, (ft; and,
lastly, copper turmngs, tf. The
tube is enveloped in oo^^wr foil (v
brass wire gauze, and connected by
a eas deliyery-tube with a gradnated

iing oyer mercury (^.36), and partly filled with strong solution of potsA
is laid in the combustion furnace, and the acid carbonate of sodium gradually

heated, tiie other jMurt of this
Fig, 36. tube being protected by a

screen. Carbonic acid gas
is then erolyed, and driTei
the air out of the tube. It
is tested from time to time
by collecting it in small
tubes filled with meiciny>
and passing caustic potash
into it. As soon as the
gas is completely absoibed
by the potash-ley, showinc
that all the air IS expelled
from the tube, the heat is remoyed from the acid carbonate of sodium ; the gndnated
jar, filled partly with mercury, and partly with potash-ley, is adjusted in its phw»
oyer the extremity of the delivery-tube, and the combustion is commenced. The
nitrogen and carbonic acid then pass over together ; the carbonic acid is absorbed

ELEMENTABY OR ULTIMATE. 243

Vj the potash ; and the nifarogen collects in the jar. When the oombostion in finished,
heat is again applied to the aeid carbonate of sodinm, so as to evolve more carbonic add,
and sweep all die residnal nitrogen into the gas jar.

The gas is left standing over the caustic potash till the absoiption of the carbonic
add appears to be qoite complete : it ma.;^ be accelerated by a gentle agitation. A
ground ^aas plate is then placed under the jar, pressed against it, to prevent the mer-
Guy firom running out^ and the jar is transferred from the meicuiy-trough to a large
Teasd of water. On removing the glass plate, the mercury and potash-ley run out,
their place being supplied by water. The volume of the gas is then read ofi^ and
ledueed to the standwd pressure and temperature, allowance being also made for the
tendon of the aqueous vapour. From the corrected volume of nitrogen thus obtained,
the weight is easily deduced by calculation.

If commercial bicarbonate of soda is used in this process, it must be tested
beforehand, in order to ascertain whether it gives off any gas not absorbable by
potash. Indeed, it is advisable to subject all the materials used in the process to a
trial by ignition without the organic substance. They ought not to yield more than | to
1| e. c' (Kf gas not absorbed by potash-ley.

It is also of the greatest importance, in all nitrogen estimations in which the
nitraeefi is determined by volume, to test carefully the accuracy of the weights with
which the substance to be analysed is weighed out In other analyses, the absolute
Tafai#i of the weights used is unin^rtant, provided they agree amongst themselves ;
but if the gramme weight and its subdivisions, with which the substance is weighed
oat, are not true to their standard values, the weight of the nitrogen, determined' by
calculation from its observed volume, according to fixed data, wul not give the true
weight of nitzogen contained in the compoxmd.

Another mocUfication of Bumas's process is given by Dr. Maxwell Simpson
(Chem. Soc. Qn. J. vi 299). The combustion is made with a mixture of oxide of
copper and mercnne oxide^ the free oxygen evolved by the latter being absorbed by
red-hot copper, and the atmospheric air expelled by a stream of carbonic add, evolved
from carbonate of manganese. The gaseous mixture evolved bv the combustion ii
eoUeeted in a reodver of peculiar constniction, from which, after the carbonic add has
been absorbed by potash, the nitrogen can be transferred, without loss, to a eudio-
meter, and accurately measured over mercury. The details are as follows : —

A eombustion-tabe, from 2| to 3 feet long^ is sealed at one end, and a mixture of
12 gnn. carbonate of manganese and 2 gnn. mercuric oxide (the latter being added to
pievent the possible formation of carbonic oxide) is introduced into it At an inch
from this nuxture is placed a plug of asbestos, and then the mixture of the substance
to be analysed (5 or 6 dedgm.) with about 45 times its weight of a mixture of 4 pts.
oxide^ of copper and 6 pts. oxide of mercury. To ensure that the oxide of mer-
cmy is free mm nitrogen, it must be prepared, not by ignition of the nitrate, but by
predpitatinff oorrodve sublimate with excess of caustic potash; the predpitato is
washed with aqueous phosphoric add, to remove free potash, then witn water, and
dried at a rather strong heat.

The mixture having been introduced, the mortar is rinsed out with oxide of copper,
and the rinsings addMl as usual ; then a plug of asbestos is thrust in ; then 2 or 3
inches of pure oxide of copper added, this aSao being kept in its place by an asbestos
phig; and the tube is filled up with metallic copper, prepared by
reducing the coarse-grained oxide (p. 226) with hydrofijen. The open Fiff. 37.
end of the tube is then drawn out, and the neck joined by a
eaootdiouc connector with a gas ddiveiy-tube, bent at right angles
and dipping into the mercuxy-trough.

The combustion-tube is now laid in the fiimace, and heat is applied
to the metallic copper and oxide of copper, and f^ the same time to
the carbonate of mancanese, the heatea portions being shut off by
Bcreeos from the midme of the tube ; and as soon as the air is com-
pletely expelled from the tube by the stream of carbonic add, the
mixture of the organic substance with the oxides is heated in the
.usual way, fiiom the front backwards, the tube being first connected
with the vessd intended to reodve the nitrogen. This vessel has the
tem shown infy. 37, and a eapadty of about 200 cub. cent : the ex-
ternal diameter of the upper part should not exceed 7 or 8 mm.
A tnbe of thidc vnlcanisea caoutchouc, 1| inch long, is slipped over
the top, which it must accurately fit, to the extent of half an inch, and securely
bound round with silk cord. A glass rod, half an inch long, with the ends ground
flat, and having the same diameter as the caoutehouc tube, is thrust down the latter
till it touches the gas vesseL A piece of thermometer tubing, also of the same dia-
meter, and having a fine hair-bore, is bent into the form shown in fiff. 38, and also

244 ANALYSIS (ORGANIC)

inserted. The e&oatchotie ie n«it BlightJy rtrelthed over it, and Brmlj (Murnd irith
tfilk cord, 10 that there maj be no iiiCerv^ between tJie glaaB rod, hent tnbo, ind gu
Teasel. A silk cord it, Uetlj, tied round the port of the coontchonc tube «bae lbs
solid rod liea, bo aa to moke it perfectly aii-tight. Before oeiiig the appuuhu, the
joints must be tested hy partialjj filling it with mercoiy, [Ranging the moitli
beneodi the surbce of ttie liqnid, and observing if the level remains constant

The apparatus is completely filled with mercuij and caustic potash nlalign, lod

placed in the mercnciol trough as shovn in^i^. 3S. The gas deliTery-lobe, piscatdin;

from the oombnflHo.

^ «rted into its Istoil

opening, the poduOi
of comhuiticai pan into
I it, the carbomc ind
being abeoi^wd V ''"
potush-ley, vliile tbe
nitrogen lem^na. M
the termination of tie
combnitioii, the nitn-

the tnbe is iwepl ml

stream of cubonic idd.
evolved bj heating ttie
portion of cubmiaU it
manganne still imaiD-
ing undMomposed.
The next thing to be done is to transfer the nitiogei) to a endiometiic tnbe. Fot
this purpose a bent tube, narrowed towards the lower part of the upright ana a GUeJ
air tight to the lateral opening of the receiver b/ means of a cork, care being Uken
that DO air is introduced in fitting it, to euaure which it is beat to moiBtenlhe oni
with a solution of corrosive sublimate. Mercury is now poured into the bent tobf,
and the receiver is lifted out of the mercury, carried to a mercurial trough vith glio
•ides (fy, 39), and allowed to stand for an honr or two, so that the absorption of the
carbonic add may be com-
Fig. 3B. pleta, A eudiometer, pre-

viously moistened vilh a in^
of water, so that the gis mi;
be saturated with moisture,
is then carefolly fllltd "ili
mercQiy, and inverted in the
trougb ; tbe end of the |><
1 delivei7-tube from the «■
I oeiver is brought nnder it;
I the coid which tied Uu
caontchouc tube to the |lM
rod is removed ; and the a-
tiogen is driven into the
eudiometer bj slowly fonnag
meteury into tie bent tabt,
as shown in the fignra, it
aoon as the potash-ley niikf*
its appearance in the gia d^
livery-tube, the addition of
mercury is stopped, lis
volume of nitK^ whim
then remaine in the gas delivery tnbe is exactly equal to the volume of the airwhidi
was oontaincd in it at the beginning of the process, and was driven into the oadiome'er
tube by the first portions of mercury added, so that the volume of gas driven into the
eudiometer is exactly that which was contained in tbe receiyec. lastly, the n» »
measnred, with due regard to pressure and temperature, and the weight calonlittd
accordingly.

This process gives very exact results. Its peculiar advantages ire, that the free
oxygen evolved from the oxide of mercury ensures eon^lete combostioii, whil« th'
vupour of meicury prevents the formation of any oxides of nitrogen r moreover, it
enables the gas to be measured over mercury, which is much mora exact than li«
ordinary mode of measoriug over water.

ELEMENTARY OR ULTIMATE, 245

Eitimaliom ofNiinigai by Will and VarToitTapji'i Method. — Mort azotued organic
bodiea hesh^ with hjdmle of potassinm or Bodinm, give off tJie whole of their nitrogen
in (he fonn of ammonia, the carbon nniting vith the o^rgea of the alkaline hjdiata to
fwincarbomcaeid.iThiletlieh;clTogen combines with the aitrogen to form ammonia. If
the quantity of nitrogen prEeent ii not anffldent to unite in this maiuior vith all the
hydragen, the remainder ia evolved as gaa ; but there ia no organic anhstance, ex-
cepting tboK containing nitrie add, in which tht quantity of nitrogen is too great to be
eompletelj conreited into ammonia b; the hTdrogen thus liberated from the alkaline
bjdrate. In many cases, however, cyanide of potassium or sodium is formed in the
flrat instance ; but even then, if a sufSdent excess of the allialine hydrate ia present,
the cyanogen ia decomposed when the heat becomes very atrong. and the whale of the
nitrogen is giren off as ammonia. It is on these iscta that Will and Tarrentrapp'il
method of «timating nitrogen is ' — '-'

Aa the hydrates of potasaium
glaaa at high letnperatorea, it is
theiD more manageable, and diminiahea their action on the glaaa. The miitnre
genermllr oaed ia toda-lime, containing 1 pt. of hydrate of sodium, and 2 pts. of quick
ume. It is prepared by adding the requlaite quantity of quicklime to caustic soda-ley
of known strength, evaporating to dryness m aa iron pot, ealciniiig tbe residue in a
cnieible, snd afterwards rubbing it to fine powder in a warm mortar. It must be
I*«aerTed in wide-monlhed Tessela with good atoppeca. If commercial soda ia used
jbr this purpose, it rooBt be prerioualy teated for nitric add, aa the presenca of that
co^ionnd would vitiate the analysia.

llie Bobetance to be analyaed is mixed in a warm porcelain mortar, with a qoantity
of eodA-liine sufBdent to fill about tiro-thirds of a combustion-tube, &om 16 to
IB inchea long. The aoda-lime most be previously heated over a lamp to eipel any
QMiatore or ammonia that it may have absorbed, and the miitnre mnst be made by
veiT gentle tritnratioB. otherwise portions of it will adhere obsfinalely to the mortar
and pestlei After it has been introdaced into the tube, the mortar is rinsed with
fieah aods-Unke, and finally with pounded glass, to remove any small portiona of ad-
beriog matter. lastly, the tobe is filled up with aoda-lime to within an inch of the
^Ltrtmi^, a ping of ignited asbestos being placed at the end to prevent the light
powder &Qm being earned forward by the vapoun.

The ammonia is collected in a bulb-apporatua of the form ahowa in fig. 40, con-

Fig. *0.

tube ia gmdnally healed from end to end. Ammonia is then given
off and la absorbed by the hydrochloric add. Towards the end of the combustion, th?
hsat moat be very much increased, in order to decompose any cyanide of sodiom that
may have formed in the earlier stage of the process. When the combustion ia finished,
thepointof the tube is broken off and air drawn through the apparatiia in the asaal way.
Bonia (Bullet. Soc Chim. de Paris, i. 106) recommends to pUce at the closed end of
the tnbe a mixture of oxalate of calcium and slaked lime (obtained by neutralising
oxalic afid with milk of lime, boiling the prccipitato with excess of lime, and drying
rapidly at 110" C.) which, when decompc»«d at the end of the operatioo, evolves a
ctKun of hydrogen that sweeps all the ammonia remaining in the combuation-tube into
the add placed to receive it.

T^ acid liquid ia emptied into a capanle. and the bnlba are rinsed with alcohol,
and then repeatedly with distilled water. Sometdmes oily hydrocarbons are formed
daring the oombiiBtion, and collect on the surface of the acid liquid. In tbia case it
ia beat, before proceeding farther, to separate the oil from the acid liquid by flltration,
the filter being previously mcistened with water. Bichloride of platinum is now added
to the arid solution, which precipitates the ammonia as chlaropfatinato of ammonium,
NB'CI . PtCi' ; the whole is evaporated to dryness over the water-bath ; and the diy
maas when cold, ia treated with a mixture of 2 volumes of strong alcohol and I vol.

246 ANALYSIS (ORGANIC)

ether, which disflolres the excess of bichloride of platinum, and learefl the chlonv
platinate of ammonium. This salt is collected on a weighed filter, washed with the
same mixtuxe of alcohol and ether, then dried at 100^ and weighed ; 100 pts. of it
correspond to 6*279 pts. of nitrogen. Or, the salt with its filter maj be ignited in a
weighed crucible of platinum or porcelain, till the filter is completely bnmed to ashes
and metallic i>latinum is left The ignition must be performed with great eaie^
commencing with a Tery gentle heati which should be increased rery gradually,
because the yapours of sal-ammoniac and chlorine which escape are yery apt to esrry
with them a small quantity of platinum : 100 pts. of platinum ooirespond to 14*204
pts. of nitrogen.

The process just described may be applied to most axotised ofganic bodies without
Airther modification. Sometimes, however, when the proportion of nitrogen is huge,
as in urea) mellone, &c, the whole of the hydrogen is given off as ammonia. In this
case, the quantity of unoondensable gas evolyed is oomparatiyely small, and towards
the end of the process, the acid in the bulbs is veiy likely to be suddenly drawn back
into the combustion-tube. This accident may be prevented by adding to the mixture
a small quantity of sugar or tartaric acid, so as to dilute the ammonia with unoon-
densable gases.

Liquids containing nitrogen may be treated in the same manner, being enclosed in
bulbs, as for combustion with oxide of copper.

There are some azotised organic bodies to which Will and Varrentrapp's process is
not applicable, — those, namely, in which the nitrogen exists in the form of an oxide,
generally as NO' (the so-called nitro-compounds) : these bodies, when ignited with
an alkaline hydrate, giving off only a portion of their nitrogen in the form of ammonia,
so that the quantity found is always too small.

Other azotised bodies, when heated with soda-lime, give off, not ammonia, but Ofganie
bases free from oxygen, and more or less resemblinj^ ammonia. Thus indigo yields
phenylamine (CH'N), and many non-volatQe organic bases, e.ff» narootine, mcMphine,
quinine, and dnchonine, give off oiganic volatile bases. Many non-oxygenised
organic bases, such as phenylamine, chinoline, &e., pass over i^ted soda-lime without
decomposition, or at all events do not yield sll their nitioeen in the form of amiiM»ia.
Now all these volatile oiganie bases form platinum-suts, in which, as in diiloio-
platinate of ammonium, 1 atom of platinum corresponds to 1 atom of nitrogen. I^
th««fore, these bases are treated by Will and Vacrentrapp's process^ the nsoltin^
platinum-salts ignited, and the metallic platinum weighed, 100 pts. of it will oorte^wnS
to 14*204 pts. of nitrogen, whatever oiganic base may have been formed in the deoom-
position. As, however, the platinum-salts of many of these bases are more soluble in
alcohol than chloroplatinato of ammonium, it is best to wash them, not with the
mixture of alcohol and ether above-mentioned, but with absolute ether to which only a
few drops of alcohol are added. In all cases in which it is not certainly known that the
body suomitted to analysis gives off the whole of its nitrogen as ammonia, the chkno-
platmate should be ignited after being weighed, and the residual platinum weired
again, so as to ascertain whether the chloroplatinate weighed was reaUy chloroplatinate
of ammonium. (NH^PtOl' corresponds to 44*3 per cent platinum.)

Instead of precipitating the ammonia with bichloride of platinum, its quantity may
slso be determined volumetrically, for instance, by reoeiyin^ it in dilute sulphunc add
of known strength, and estimating the quanti^ of free aad remaining hv means of a
standard alkaline solution. P^ligot uses for this purpose dilute sulphuric aad, containing
61-25 grms. of SO^H*, in a litre of liquid; neutralises it with a measured quantity of
a solution of lime in sugar-water ; ana compares the quantity of the lime-solution re-
quired for this purpose with that which is required to neutzaUse the same volume of
acid after absoiption of the ammonia. Instead of the solution of lime in sugar-water,
which quickly varies in strength, and must be standardised before each eneiiment, it
is better to use a standard solution of caustic soda (see AcmafBTBT, bm Akaltsb
YoLUXETBic). If an acid be used containing 1 at. SO^H* in a Utre of liquid, and a
solution of soda containing 2 at NaHO in the same volxmie of liquid, the quantity of
acid saturated by the ammonia will be ver)^ readily found, and thence also the quanti^
of ammonia absorbed. These methods, being more rapidly executed than the platinum-
determination, are especially applicable in the determination of nitrogen for tAr*hi^iWl
purposes, in the valuation of euano for example.

Other modifications of Wm and Varrentrapp's process have been proposed, fat
example, receiving the ammonia in tartaric acid, — l)ut they do not appear to preamt
any peculiar advantages.

EsTDCiLTioN or Chlobimb.

Oreanic bases combine with hydrochloric acid, forminp; salte (the hydrochlorate of
morphine, for example), from the solutions of which chlorine may be completely pteci-

ELEMENTARY OR ULTIMATE. 247

pitated bj simp] j adding nitrate of aolTer. Bat many oiganie compounds contain
chkrine in a fonn in wmch it cannot be pzecipitated aa cbJozide of silver, nntil the
eomponnd ia eompleteij destroyed.

The mode of decomposition adopted in soch cases is to ignite the compound with a
caustic alkali or alkaline earth, generally with quick lime. The lime used for the
pozpose ia obtained by subjecting marble to a strong red heat in a crucible. It must
be tested for chlorine, and if that element is found in it» the lime must be daked, and
the eUoride d calciom separated £rom it by crashing -with water, after which it is to
be recalcined.

The organie compound, if solid, is mixed in a mortar with the pure pounded lime,
the mixture introduced into a combustion-tube from 12 to 18 inches long, and the
tube filled-up with pure lime, or (in order to diminish the quantity of lime which has
to be subsequently oissolTed in nitric add) with a mixture of lime and pounded glass.
The mixture is then burnt in the usual manner ; afterwards, while tne tube is still
hot, the open end is closed by a cork, it is then wiped with a piece of filtor^paper, and
gradually introduced into a tall glass cylinder about one-third full of cold distilled
water: the hot tube breaks on thus coming in contact with the water, and its contents
fall into the cylinder, where the excess of lime is dissolved by nitric acid. The liquid
is then filtered, if neeessaiy, and the chlorine precipitated by nitrate of silyer. Or,
the oontents of the tube when cold are turned out into a jar of distilled water, and the
whole is diasolved by nitric acid. This method, however, is more subject to error than
the first ; for it is difficult to prevent a portion of the veiy fine dust of lime being
carried away by the air while emptying the tube into the water.

liquids containing chlorine are endosed in bulbs in the manner slready described
(p. 232), and the vapours passed over the red-hot lime.

Broadne and iodine in organic compounds are estimated in like manner.

Estimation of Suipeub.

Sulphur 18 sometimes contained in organic compounds in such a manner that it
exhibits its usual reactions with metallic solutions ; more generally, however, its sepa-
ration can only be effected by the complete destruction of the compound. In some
cases^ oxidation with strong nitric add will effect the decomposition, the sulphur bein^
converted into sulphuric add; but a more certain method is to fiise the compoima
wiUi an alkaline hydrate or csrbonate, mixed with nitre^ chlorate of potsssium, or oxide
of mercury.

For non-vdatQe bodies^ a hw lumps of hydrate of potassium am fhsed in a silves
crudble over a piB Ump^ with about f of nitre, a fbw drops of water being added to
fa^l'ta*^ the fosion ; a weig^Md quantity of the sulphuretted organic compound is then
added in sneoessive smsll portions, and the heat is gradually raised, small quantities
of nitre being thrown in from time to time, if necessary, to bum away the carbon.
The fused mass when cold is dissolved in boiling water, the excess of alkali neutralised
with hydrochloric add, chloride of barium then added, and the predpitate of sulphate
of barium filtered, washedt and ignited with the osual precautions. (See Sujlphubio

AOD.)

Sulphur-compounds may also, whether fixed or volatile, be burnt in a combustion-
tube with a mixture of carbonate of sodixmi, with nitre, chlorate of potassium (Kolbe),
or <ndde of mercurv (Bus sell, Chem. Soc Qu. J. viL 212), — ^non-volatile pulverisable
solids behig mixed up with the carbonate of sodium and the oxidising a^t, volatile
liquids bemg endosed in sealed bulbs, and volatile solids and fiitty bodies placed in
piftfimnn boats,

EsmcikTiGir ov PBoaPHOKUB.

Plios|>boni8 in ozganic bodies is estimated by burning the substance with a mixture
ci alkalme carbonate and nitre or chlorate of potassium, in the same manner as for
solphnr, and psredpiteting the resulting phoapnoric add as phosphate of magnesium
and ammonium. SimilarJy for arsenic.

Other non-volatile substsnces occurring in organic compounds are estimated by the
ordinary processes adapted to each of them, in the reddue left after the organic matter
has been Domt away.

An easier method of estimating sulphur, phosphorus, chlorine, &c., in oreanic com-
ponnds, latdy introduced by Carius (Ann. Ch. Pharm. cxvi 1), consists m heating
the substance with nitric add, of specific gravity about 1*2, in a sealed tube.
8utpkur is thereby, in nearly aQ cases^ completely converted into sulphuric acid, and
may be predpitated b^ chloride of barium ; phoephorut and arsenio are converted into
phosphone and arsenic adds, and may be predpitated as ammonio-magnedum salte ;
cUorine is partly oxidised, partiy separated in the firee state, but may be completely

248 ANALYSIS (ORGANIC) PROXIMATE.

converted into hydrocUoric acid ^by means of a dilute solution of snlphnrons acid or
sulphite of sodium, and then precipitated by nitrate of silver; bn/mme and iodme are
completely separated in the nee state, and may be estimated in like maimer ; lastly,
metala are converted into oxides or nitrates, and may be estimated by the oocdinary
methods of mineral analysis.

This method of oxidation by nitric acid in sealed tubes, is likewise applicable to
many inorganic compounds, the sulphides of arsenic, for fxampK (For detoils^ see the
articles CKLOBDia^ fBosPHOBUS, Sulfbub, &c)

Bbibbkeia^iion of thb Chbmzoai. Fobhuia of ax OsaAnio CoKPOuiro.

When the quantities of the several elements of a compound which make op a given
weight, say 100 parts, are known, it is easy to calculate the relative number of atoms
of these elements. For, since the actual weight of a substance {W) is equal to the
weight of «u^ atom (^), multiplied by the number (n) of the atoms (FT — n ^), it
follows that the number of atoms is equal to the total weight divided by the atomic

weight (n a ^) ; so that^ when the percentage composition is known, the zdatiTe

numbers of the atoms — ^in other words, the empirical formula — ^will be found by dividing
the percentage of each element by its atomic weighty and reducing the result to ita
simplest numerical expression.

For example, sorbic acid is found by Hofinann's analysis (Chem. Soc Qo. J. xii. 16}
to contain in 100 parts : 64*38 C, 7*20 H, and 28-42 0. Therefore :

64*38
Number of Carbon-atoms ■> —tk- ■" ^'^^ o^^ ^

7*20
„ Hydrogen-atoms -« — r — — 7*20 or 4

„ Oxygen-atoms ■■ - -^ « 1*77 or 1

consequently, the simplest atomic expression of the c(m8titution of sorbic acid is
C»H*0.

Whether this is the real expression for the composition of the moleenle^ or whether
it should be CH'O', or CH^^O', or any other multiple of the first formola, must be
determined by other considerations. In the case of an acid, we naturally look to the
constitution of its salts, the barium- and silver^salts being generally selected as being
the most easily prepared and analysed. The analysis of sort>ate of barium gives :

Carbon

Hydrogen .

Barium . . .

Osgrgen

10000

This approaches very nearly to the formula CHTBaO*, showing that the rational
formula of sorbic acid is, not &H*0, but C*H*0', supposing the acid to be monobasic, or
C*^**0^ if it is dibasic Which of these hypotheses is correct must be determined
by other eonsiderations (Acms, p. 46). The monobasic formula is adopted because it
is found that sorbic acid forms but one class of salts, one ether, one amide, 4bc

The rational formulse of bases are also determined by the constitution of their salts.
The platinum-salts are most generally relied on, because they can be easily obtained
pure, and the platinum can in most cases be determined with great aocuracy. The
rational formula of the base is that which cotresponds to 1 atom of platiimm, Thus
the platinum-salt of nitranindine gives numl^rs cotresponding to the formula,
CH*N'0".HCl,Pta*: hence the formula of the base is C'H"N«0". In some cases, the
gold-salts are better adapted than the platinum-salts for determining the constitutioa
of an organic base. But any well defined and stable salt in which the amount of add
or add-radicle can be directly and accurately determined, will answer the purpoee
equally well.

To determine the rational formula of a compound which is neither add nor banc,
recourse must be had to its derivation and to its modes of decomposition. Thus
indigo yields by analysis numbers corresponding to the formula, C*H*KO. By
oxidising it with nitric add, we obtain isatin^ C*H*NO* (^ indigo + O) ; and isatin
treated with potash yields the potassium-salt of isatic add, C*H'KNO*. Now, as
isatic add exhibits the characters of a monobasic acid, this fonnula shows that it eon-

[n 100 pU.

atwt.

No. of atoms.

40-87

+ 12 -

3*36 or 6*08

4-02

+ 1 =

4*02 or 7*27

87-89

+ 68*6 -

0*56 or 1

17*72

•t- 16 a

111 or 2

ANALYSIS (OBGANIC) PROXIMATR 249

f*iiMi 8 atoms of carbon ; and oonseqnently isatin and indigo, which are related to it in
the manner just mentioned, most also contain 8 atoms carbon. Substitution-prodacts
formed under the influence of chlorine, nitric acid, &c are often of great nse in deter-
mining rational formnlsB. Thna the composition of mesitylol may be expressed em-
pirieaSy by either of the formn]», C■H^ G*H' or O^H^*. But this body, under the
mfluenoe of nitric add, yields the three substitution-products, nitromesitylol,
CH>*(NO>X dinitwmeaitylol, CW^NO^*, and trinitromesitylol, G*H*(NO*V|, the com-
position of iHiich is utt^y irreconcilable with the formula, G'H\ or G^. Again,
the eompoeition of napktkaliniDight be expressed empirically by the formula, G**H', or
C»H«; but the existence of the compounds, C»»H'C1, C»«H'a*, C'*H*C1«, C"H»BtCl«,
C>*H*BrCi', and G'^H'BrH}!', shows clearly that the higher formula is the true one.

When a oompound is volatile without decomposition, its atomic weight may gene-
rally be determmed by means of its vi^ur-density. In nearly all cases, the mole-
cule of a compound in the gaseous state is supposed to occupy 2 yolumes (Atomio
Yolukb), in other words, the Tapouislensity is half the weight of the molecule, and
the formula of the compound must be calculated accordingly. Thus the yapour-
density of alcohol, as determined by Qay-Lussac, is 1*6133, referred to air as uni^, or

1*6133

z — tz- a. 23*25, referred to hydrogen as imity. The double of this number, or 46*5
0*0093

m therefore the weight of the molecule. Now the composition of alcohol, as deter-
mined by elementaiy analysiB, is CHK), and the weight of the molecole calculated
from this formula is 46. The formula of alcohol is therefore CHK) and not any mul-
tiple thepeot

XL Pboximatb Oboanic Analysis.

The knowledge of the ultimate elements of which an organic body is composed, is
not sn£Beient to giye a complete idea of its constitution, unless the substance under
examination is a definite chemical compound, such as sugar, alcohol, albumin, &c In
that ease, all the knowledge that we wish to obtain, or indeed that we can obtain re-
garding the constitution of the body, is deriyed from its elementary analysis, together
with the study of ite chemical reactions ; but when a complex organ, as a leaf or a
root, or a yegeteble or animal fluid, such as the sap, milk or blood, is to be examined, it
is necessary, before proceeding to t^e ultimate analysis, to separate the seyeral definite
compounds ^ proxmaU dements^ of which the complex substance \b made up; just as
in o^ttintumg a sample of granite, it is not sufficient to know the relatiye quantities
of ailioon, akuninium, potassium, oigrgen, &c, which it contains, but we require
also to know something of the manner m which these elements are grouped in the
form of defimto minerals ; in other words, to ascertain what proportions of quartz,
felspar, and mica enter into the composition of the rock.

The ultimate analysis of oreanic lx>diee is, as we haye seen, reduced to a yery com-
l^eto system ; there is indeed no element occurring in an organic compound which
cannot be detected with certainty, and estimated quantitatiyely within yery narrow
fimits. But it is otherwise with the proximate analysis. With regard to yj^teble
substances inpazticnlar, nothing more than a few general directions can be ^yen. In
the case ctf anmtal bodies, some pogress has been made towards the estebhshment of
a systematie course of quaUtetiye analysis, but much remains to be done before the
method can approach in regularity and exactness to the processes of mineral analysis.

The substance, whether yegeteble or animal, soUd or liquid, is dirided into two parts,
one for the determination of the inorgaidc, the other for that of the organic consti-
tuents. The former is dried and incinerated (see Ashbs) and the ash examined by
the processes of mineral analysis. The former, if the analysis is to be quantitetiye,
and m some instances also for qualitetiye analysis, is dried at a temperatare between
100^ and 110^ or 116^ C, |preat care beiiuf taken not to let the heat rise too high, as
Ofganic bodies are yery easily decomposed by heat. Some bodies must be dried at
the ordinaiT temperatare oyer sulphuric acid. la^oids are first eyaporated in
shallow basms oyer the water-bath, and tiie residue is then dried at a somewhat
hi^iier temperature.

The dried residue or the original substance, is then subjected to the action of
variooa solyents, senerally of ether, alcohol and water. Oerhardt recommends these
solyente to be used in the order here indicated: this of course implies that the sub-
stance is nreriously dried. Ether dissolyes especially fatty and waxy substances,
resins ana camphors; alcohol dissolyes the same substances with less fiunlity,
but on the other hand, it dissolyes many substances which are insoluble in ether ;
water dissolyes saccharine, gummy and amylaceous substances, and salto of organic
adds. Benzol, oil of turpentine, chloroform and sulphide of carbon, are also
used as solyents. Yegeteble alkalis are extracted by dilute sulphuric or hydro-

250 ANALYSIS (ORGANIC) PROXIMATE.

chloric acid ; organic adda by dilute ammonia or potash. The solationa of Tegetable
adds, and of certain other substances thus obtained, are often treated with acetate or
subacetate of lead, in order to precipitate the organic prindples in the foniL of in-
soluble lead-salts, whidi are then decomposed by sulphuretted hydrogen. At^t^f^ of
aluminium and feme acetate are also used as precipitants.

The solutions obtained in this way generally contain a mixture of proximate ofganie
prindples, which must be separated by fractional distUIation, precipitation, aaturaliiCHi,
or crystallisation : when crystals are obtained, it is mostly of great service to examine
them by the microscope^ in order to determine thdr form, and asoectain whether they
are homogeneous.

Fractional predpitation with acetate of lead is much used for the separation of tlie
higher terms of tiie fatty add series, stearic, palmitic, add, &Q. The mixture of fiitty
adds is dissolyed in alcohol ; the solution is partially predpiteted with acetate of
lead ; ihe predpitate is decomposed by sulphuric add ; the &tty adds thereby sepet-
rated are redissolyed in alcohol, and again partially predpitated; and this series of
operations is repeated till the fatty add thus separated shows a constant Tnaltiwg
point

The method of fractional aaturaHon applied by Liebig te the separation of some of
the lower terms of the fatt7 add series, may also here be noticed. When ralerie and
butyric adds occur togetner in a liquid, their separation may be effected by lialf
saturating the mixture with soda^ and distilling. If the valeric add is in excess, pure
valerate of sodium is left behind, and a mixture of butyric and valeric adds HigriU
over ; i^ on the contrary, the butyric add is in excess, the residue contains butyrate as
well as valerate of sodium : but the distillate consists of pure butyric add. On dis-
tilling the residue with excess of dilute sulphuric add, the two adds pass over together,
and by partially neutralising the distillate with an alkali, and agam distilling a fiir>
ther separation may be effected. At each stage of the process, the less volatile acid
(the valeric) displaces the more volatile, and one only of the adds is found either in
the distillate or m the residue, according as the more or the less volatile acid predo-
minates. When a mixture of acetic add with butyric or valeric add is treated in this
manner, different phenomena present themselves, tlie acetic add, though the most
volatile, exhibiting the greater tendency to displace the other two and remain in the
residue. Thispeculiar behaviour is due to the formation of an add acetate of sodimn,
C^H'NaO^C'H'O*, which is not decomposed by either of the other adds. Hence,
if the mixture contains more acetic add than is suffident to form an add acetate with
the quantity of soda added, the excess will pass over together with the whole of the
butyric or valeric add present^ the residue consisting of pure add acetete of sodiiun ;
if, on the contrary, the quantity of acetic add is lees than suffident to oonvert the
whole of the soda into the add acetate, pure valeric or but^c add will pass over, and
the residue will contain acid acetete of sodium, mixed with butyrate or valerate.

Volatile oils are separated bv fractional distillation. The roots, seeds, leaTea, &cl,
containing them are macerated in water and distilled, and the oils which pass over
with the aqueous vapour, are 8^)arated mechanically from the watery distillate, and
subjected to fractional distillation, the portions which distil at constant boiling points
or between narrow limits of temperature being collected apart Hany volatue oils
have the composition of aldehydes, and these are separated from mixtures containing
them, by agitetion with a saturated solution of add sulphite of sodium, with whii^ th^
form oystaUine compounds. •

In most cases, however, more information will be obteined concerning the best
method of procedure in any particular case, by consulting the metiiods which axe
actually in use for separating spedal substances from, complex mixtures in which they
occur, than from any general rules : see for example the artides AuukLoms (dbtbctxox
cif)j Bomb-oil, Gimchona.-babx, Ofiux, for the methods of separating alkaloids ; the
artides Bilr, Oleio Acm, Stbabio Acid, Ubio Acid, &c, for the methods of separating
acids ; and the artides Axbuxik, Gh^TCEBiN, Sxtoab, &c., for the methods of separating
neutral bodies.

Examination of Animal Substances: Zoochemieal Analysis. — The
general directions just given for the proximate analysis of complex orgamo bodies, aire
for the most part equally applicable to vegeteble and to animal substances : bnt the
proximate prindples of the animal body being less numerous than those of the
vegeteble kingdom, where distinct proximate principles occur in every natural order
and in many individual spedes, it is somewhat easier to lay down a systematic oourae
for the qualitetive analysis of animal substances. The following is the method gi-ven
by Gorup-Besanez, in the Handtodrterbuck der Chemie, 2** Aufl. i. 984.

a. For liquids, — ^The physical characters must first be examined. Any tnii>idity or
sediment occurring in the liquid is to be examined by the microscope for the detection
of crystals, or bodies of any other definite form. An add reaction of the liquid indi-

ANALYSIS (ORGANIC) PROXIMATE. 251

eales the yreaenee of free acids or of acid salts ; an alkaline reaction, that of free
alkalis^ alkaline carbonates or phosphates (as in blood, blood-senun, and serous transu-
dates^ or of ammonia resnltin^ from decomposition (as in orine). A coagoliim forming
apootaneonslj, after a while, in a liquid oziginally clear, generally consists of fibrin ; it
maj also consist of organised bodies, a question to be deoded by examination with the

The liquid, clarified, if necessazy, by filtration or straininff, is now to be examined
MikdlowB.

1. A portion of it is heated in a test-tabe to the boiling point, acetic acid being
added, before the boiling heat is attained, in sofildent quantity to produce a £unt
acid reaction, in case the liquid was ongimilly neutral or alkaline.

«. If no distinct coagulum is ibzmed, albumin is absent : pass on to (2).

K A distinct coagulum or turbidity is produced: Biyide the liquid into two portions.
To one portion add a few drops of dilute hydrochlozic acid. If the precipitate dis-
appears, albumin is absent, but earthy phosphates are probably present. Look for
them by the microscope or by chemical tests.

If the coagulum or turbidity does not disappear, add hydrochloric acid and heat to
the boiling-point ; if it dinolyes gradually, with blood-red colour, album ii^ is present :
for & eoofirmatoij test, add a lew drope of nitric add to a small quantity of the
origualliquid.

K.B. If the coagulum fozined by boiling the liquid, or the liquid itself^ has a reddish-
tinge^ hematin and globulinmay be present. The coagulum ii then to be digested
in aleobol containing sulphuric add, and the liquid treated with the tests specially
adapted to the discovery of those compounds.

2. The liquid in which no coagulum ia produced by boiling, or the liquid filtered
from the coagulum in the contrary ease, may stQl contain the following albuminoidal
substances: paralbumin and metalbumin, casein andglobulin.

If only a turbidity was produced on boiling the liquid, paralbumin or metal-
bumin may be present. Add acetic add during ebullition; if the liquid then becomes
turbid or deposits flocks, and yields a turbid filfarate, if it also giyes a predpitate with
fefroeyanide of potassium and nitric add, and the last-mentioned predpitate is inso-
luble in excess of nitric add, paralbumin is present. Then look for metalbumin
witli alcohol and fetrocyanide of potassium. If alcohol produces a predpitate soluble
in a large quantity of water, but ferrocyanide of potassium produces no predpitate,
metalbumin is present.

If the liquid remains perfrctly clear on boiling, it may still contain the following
albnminoidanbataDces and their deriyatiyes; casein, globulin, glutin, chondrin,
pyin, and mucus.

A sample of tiie liquid is mixed with ferrocyanide of potassium. If it remains
dear, cftsein and g^bnlin are absent: pass on to (3).

If apiredpitste is finmed, test for caseizi with solution of chloride of caldum and
boilii^ also with calfs rennet; for globulin, by observing whether a predpitate is
foxmed by neutralising the solution after it has been made acid or alkaline.

3. To a portion of we liquid add acetic add. If it remains dear, pyin, mucus,
•ad choi^dr in are absent: pass on to (4).

A predpitate is formed : test the solution with corrodye sublimate. If no predpi-
tate is formed, pyin is sbsent. The occurrence of a predpitate indicaties the presence
of py i n, which may be verified by tincture of galls and neutral acetate of lead. If the
eoRoaiTe sublimate produces merely a turbidity, chondrin ia perhi^ present Gon-
eeotrate a portioD of the liquid: uie formation of a jelly indicates cnondrin, the
pMCPce of iHiieh may be confirmed by its behaviour to alum and metallic salts.

4. The liquid in whidi acetic add produced no predpitate may yet contain glutin.
Concentrate a portion strongly, and leaye it to cool : the formation of a jelly wiU then
indicate glutin, which may be ftuther tested with corrodye sublimate.

6. The original liquid — or of it contained albumin, the liquid freed from that com-
pound by boiling — ^is concentrated by a gentle heat to jf or | of its yolume^ then hoEkted
to boiling and Wt to cooL

If no predpitate fiorms, the liquid is probably free from urates : pass on to (6).

If ft pree^tate is formed, add acetic add. If the hitherto amorphous masses are then
Be«n under the microscope to assume the form of rhombic tablets, uric add is present
and may be ibrther tested with nitric acid and ammonia.

A crystalline predpitate not altered by acetic add points to the presence of sul-
phate of calcium, or phosphate of magnesium, which may be ftirther sub-
mitted to microsoopie and chemical examination. The predpitate, if crystalline, may
also contain allantoin, tyroein, hippurate of calcium, and*benzoic acid.
Hieroseoptcal examination and the general behaviour of the substance must then do-
teivine ue ftirther tests to be appUed.

252 ANALYSIS (ORGANIC) PROXIMATE.

6. The concentrated liquid in which no precipitate is formed by boiling and sub>
sequent cooling, or the liquid filtered from such a precipitate, ia CTaporated to a Byrop
on the vater-bath, and left to itself for a considerable time.

K crystals gradually form, it is left to stand as long as they continue to incresK.
They may consist of creatine, creatinine, glyccocoll, leucine, allantoin,
taurine, sarcosine, inosite, alkaline hippurates, chloride of sodium
and other inorganic salts.

It must in the first place be determined whether these crystals are orgameor
inorganic. In the former case, they must be tested especially for nitrogen, sulphur
and phosphorus (p. 221), their chemical character deteimined as neariy as possible,
and the further examination regulated accordingly. In the latter case, thermnst be
treated by tiie methods of inorganic analysis. Ii they blacken when stronely heated,
but also leave a fixed residue, they probably consist of an organic acid combined
with an inoiganic base : in that case, the fixed residue will effervesce stron^^y with
acids.

7. The syrupy residue itself^ or the liquid separated from the crystals which haTO
formed in it is evaporated nearly to dryness, and the residue exhausted with alcohol
of specific gravity 0*833.

a, A portion a£ the alcoholic solution concentrated and then diluted with water, is
tested with nitric acid containingnitrous acid, forbile-pigment: — b. A second portion
treated in like manner, is tested with sugar and sulphuric acid for the acids of bile:—
<?. A third portion is evaporated nearly to dryness, the residue dissolved in water, and
the solution examined by Trommer^s orFehling'stestfor sugar: — <L A larger poitioD
of the alcoholic solution is evaporated to a small bulk, the cooled residue treated with
nitric add free from nitrous acid, and the vessel immersed in ice-cold water or in &
freezing mixture. A laminar cr^talline precipitate exhibiting the micKHaystallise
characters of nitrate of urea, indicates urea (care must be taken to diBtingoish it
from nitrates of the alkalis). A crystalline precipitate appearing after some time, or
more quicklv after previous heating, indicate hippuric or benzoic acid, the pre-
sence of which must be verified by uie microscope ana by chemical reactions:—^. Aixa
portion of the concentrated alcoholic extract with a syrupy solution of chloride of zinc:
if a crystalline precipitate forms, it may contain creatine and creatinine: if no
such precipitate appears after a considerable time, creatine is certainly absent:—
/. The last portion of the concentrated alcoholic extract, which will exhibit a strong
acid reaction, if any free acid is present, is to be heated with oxide of zinc, filtered
hot, and a drop left to evaporate on a glsiss plate : if lactic acid is present, the dii-
racteristic dub and tun-shaped crystals of lactate of zinc will he seen by ezaminatioD
with the microscope. The presence of lactic acid may be confirmed by preparing a
pure salt of the acid from a larger quantity of ihe liquid.

8. The residue insoluble in alcohol may contain, in addition to inorganic and so-
called extractive matters, uric add, guanine, hypoxanthine, andalbami-
nates not predpitated by boiling. It must be exhausted with water, which takes np
casein, pyin, and extractive matters, together with soluble salts, then with dihte
potash solution, which dissolves uric acid, hypoxanthine, and guanine, and lastly, with
dilute hydrochloric add. What then remains may contain albumuiates wtu(» hate
become insoluble, mucus, and perhaps also silica. All these substances mnst be
further looked for by special testa.

9. Part of the original liquid is evaporated to dryness, and the remdue, pnlverised
if possible, is exhausted with ether. The ethereal extract, chiefly containing fats in
solution, is evaporated and further examined (see Fats and Gltobbidbs). The residoe
insoluble in ether is incinerated, and the ash examined by the methods of inorganic
analysis.

P, Tissues and Organs. — ^In the analysis of animal tissues, it is absolutely oeoessarr
to operate with considerable quantities of material, not less than 20 pounds ; otherwise
a very tedious investigation may be gone through without any satisfactory resnlt.

The tissue is first carefiQly comminuted and completely eodiausted with cold water;
the extract is freed from albumin by boiling, and to the filtered liquid a concentrated
solution of caustic baryta is added as long as any predpitate or turbidity is prodneed.
The precipitate ma^ contain phosphate of barium, phosphate of magnesium,
sulphate of barium, uric acid, and hypoxanthine. The filtrate is evaporated
to a syrup over the water-bath, care being taken to remove any mucous films like
casein that form during the evaporation. These generally consist of carbonate of
barium or phosphate of magnesium, but may also contain uric acid, hypoxanthine,
or barium-salts of organic acids; they must, therefore, not be thrown away. As
soon as the filtrate is concentrated to the consistence of a thin syrup, it must be leit
to evaporate spontaneously. If small short colourless prisms form in it, they

ANALYSIS (ORGANIC) PROXIMATE. 253

lirobablj consiat of creatine; as soon as they appear to be completely deposited,
they are to be separated from the mother^Iiquor, reciystallised, and submitted to
farther eximination.

The mother-liqnor is then further evaporated, and mixed with small portions of
alcohol, till a milky turbidity is prodnced, after which the mixture is left to itself for
a few days ; if granular, laminar, or needle-shaped crystals form in it, they may con-
tain, bendes creatine and phosphatis of magnesium, inosate of potassium and
inoaate of barium. To obtain the inoeic acid, dissolve the deposit in hot water,
add chloride of barium, purify the inoeate of barium which separates by crystallisation,
and separate the inoeic acid by precipitation with dilute sulphuric add.

The liquid separated from the deposit of inosates is now to be mixed with a fresh
portion of alcohol, whereupon it generally separates into two layers, the lower being
synqyy, Uie upper more mooile. The upper layer is decanted, and the lower is mixed
with an equal volume of ether, which generally causes a f^h separation. The lower
stratum thus formed mav contain alkaline lactates, inosite, and salts of the
volatile fatty acids; the upper, creatinine and leucine. The ether-alcoholic
liquid is evaporated and left to ci^stallise. If the residue gradually deposits fine
laminated crystals, dilute it with a httle alcohol, filter off the mother-liquor, and treat
the crystals with boiling alcohol ; they may contain creatine and creatinine. The
creatine separates immediately as the filtrate cools ; the creatinine crystallises from
the mother-liquor.

The heavy syrupy liquid mixed with the mother-liquor of the creatine and creatinine
18 supersaturated with dilute sulphuric acid, in order to precipitate all the baryta, and
the filtrate is distilled to obtain the volatile acids. The residue of the distillation, if
shaken up with ether, may perhaps yield lactic and succinic acids.

The residue of the distiUation, titer being freed from these acids, is mixed with
strong alcohol, tiU it becomes turbid, and left at rest Sulphate of potassium then
ciystallifles outy and on repeatedly adding fresh portions of alcohol, more sulphate of
potassiam, together with inosite, which must be separated from the sulphate of
potassium, as far as possible by mechanical means, and then by recrystallisation from
a small quantity of warm water. To obtain hypoxanthine and uric acid from the
baiTta-precipitateSy viz. that which separated in films at the beginning of the process,
and that which was produced by adding sulphuric acid to separate the volatile acids
treat the united precipitates with boiling potash-ley, filter, acidolate with hydrochloric
add, redisBolve the resulting predpitate in potash, and add sal-ammomac Uric
acid is then predpitated as urate of ammonium, while hypoxanthine remaiins in
solution, and may be obtained by evaporation as a yellowish-white powder.

If the filtrate from the coagulum of albumin, after being evaporated to a syrup,
does not yidd any well developed crystals, but after standing for some time, maisses
having a crystalline aspect, soft and unctuous to the touch, and appearing under the
mienwoope as yellowish refracting spherules, the presence of leucine may be sus-
pected. These masses are then to be separated from the mother-liquor, which, after
standing for a longer time, depodts more of them, and the entire product strongly
pressed between porous tiles and purified by repeated ciystaUisation from boiling
alcohoL If tyrosine is present^ it covers the filtrate, after it has been freed from the
albumin-ooagulum and evaporated, with numerous stellate groups of slender needles,
which for the most part remain undissolved when treated with aloohoL They may be
dissolved in boiling water, whence they separate on cooling, — ^purified by solution in
hydrocbloric acid, with addition of acetate of potassium, and boiling, — and then further
examined.

The mother-liquors i^m the leudne^ and t^sine deposits are examined as above
for volatile acids, lactic acid, succinic acid, inosite, &c

Another process for the examination of animal tissues is given by Stadeler and
CloetU :

The extracts obtained bv maceration and pressing are boiled with a few drops of
aeetie add to coagulate albumin and colouring matter of blood, and the strained
liquid, after being evaporated over the water-bath to ^ of its bulk, is predpitated
with sobacetate of lead. The predpitate, which may contain uric acid and inosite,
is collected on a filter and washed ; the filtrate is freed from excess of lead by sul-
phuretted hydrogen, and evaporated to a syrup ; the reddue, which generally contains
alkaline acetates, is freed from these compounds by digestion in cold weak alcohol ;
sulphuric add diluted with alcohol lb then added as long as a precipitate of alkaline
sulphates continues to form ; and the excess of sulphuric acid is removed by careful
adoition of barvta-water. The clear filtrate evaporated till it no longer becomes
permanently turbid when mixed with an equal volume of absolute alcohol, is heated
till the turbidity disappears, and then left at rest Any crystals which separate must

254 ANAIiYSIS (VOLUMETRIC).

be Auther examined: they may consist of creatine^ but also cf tyroeine and
taurine, which last compound has hit^ly been found by Cloetta in the tissue of the
lungs. The mother-liquor of the ciystals, if carefully evaporated to a smaller bnik,
depofiitB an^ leucine that may be present.

The precipitate produced by subacetate of lead is washed, suspended in water, and
decomposed by sulphuretted hydrogen. If the liquid filtered from the sulphide of lead
deposits, after some time, small wmte crystalline grains, exhibiting under tiie mioo-
soope the forms of uric acid, theymust be collected and examined for uric add ^
the murezide test (Umc Aom). The liquid filtered from the uric add ia eTaporated
over the water-bath, till a sample mixed with alcohol becomes permanently toibid.
The entire liqtdd is then mixed with an equal Tolume of alcohol, and wanned till the
turbidity disappears. If after some days, a deposit forms on the bottom and aides of
the Teasel, consisting of cr^staUine masses, which, when recrystaUised from water, torn
rhombic prisms insoluble in alcohol and ether, having a pure sweetish taste, and leav-
ing no residue when burnt, inosite is probably present, and must be sought for by
other tests. [For frirther details, and for the quantitatiye analysis of animal subatanoes
seeLehmann, Lehrb. d. physiolog. Chem. 2** Aufl. Ldpadg, 1853; Heintz,Lehrhi
d. Zoochemie, Berlin, 1863 ; Robin et Yerdeil, Traite de Chimie anat etphjsbL
Paris, 1858 ; Gornp-Besanez, Anleitnng eut zoocfaem. Analyse, 2** Aufl. Narabaig
1854.]

AWAXiTSlS rvOKUXBTBIC) of &XQUZB8 and SO&IBS. The method
usually employed by chemists to determine quantitatiyely the oonstituenta of a mix*
ture, consists in separating them out one after the other, either in the pure state, or io
the form of some compound of known composition, and weighing the jnoducta. 'Evftj
one who has occupied himself with such separations knows how much time they mmUlj
require ; indeed the value of an analytical result is v^y <9ften much less than that i
the time and trouble spent upon its determination. We are indebted to the aa^ty
of Gay-Lussac for the introduction of a new principle in analytical chemistiy, which in
many instances obviates the inconvenience mentioned. This consists in aubmittisg the
substance to be estimated to certain characteristic reactions, employing for soeh
reactions liquids of known strength, and, from the quantity of the liquid empioyed,
determining the weight of the su^tance to be estimated by means of the known laws of
equivalence. Let us, for example, consider the problem which suggested to Qtj-
Lussac the idea of this method. Suppose it be required to determine the amoant of
silver in an alloy of silver and copper. The older analvtical method consists in dis-
solvins a weighed quantity of the alloy in nitric acid, precipitating the ailTer as
chloride bv the addition of hydrochloric add, then filtering, washing, ftising, and
weighing the resulting chloride of silver. From the known fact that chloride of slTer
contains ^,j of its weight of silver, the amount of silrer in the allov is calealated.
The same result is evidently obtained by preparing a solution of chloride of aodiam of
known strength, and asceitaininff how much of the solution is neoessaxy and anffident
to precipitate the silver as chloride of silver from a solution of a weighed ouanti^ of
the alloy in nitric acid. The weight of the precipitated silver may be aeterauned
from the amount of the chloride of sodium employed; because it is known that 68*6
parts by weight of chloride of sodium are exactly sufficient to conrert 108 puts of
silver into cmoride of silver.

The liquid reagents of known strength employed in determinations of this nature ire
called " a tan d ar d sol u ti on s." The amount of standard solution employed in a dete^
mination mav be estimated either by weight or by Yolume ; but masmoch as the
latter method has been found easier of application, it is now unirersally employed;
and hence the method of analysis based upon the use of standaxd solutions ia called
"volumetric analysis." At first glance it would seem that nearly all analjtiesl
methods based upon weight might be transformed into processes by volume, as in the ease
of the silver determination above quoted. This is, however, not uways possible. A ^ea^
tion to be applicable in volumetric analysis must satisfy two conditions. ( 1.) It mast not
occupy much time ; precipitations, for instance, which take place gradually are at once
to be rejected. (2.) The termination of the reaction must be recoffnisable with ease and
certainty. Hence the number of possible volumetric processes is mudi limited. On
the other hand numerous reactions inapplicable in weight-analysis furnish exodlent
means for volumetric determinations.

It is proposed in this article to give a short introduction to volumetric analysis,
and for this purpose the subject will oe divided into three parts :

I. Description of the necessary apparatus.
II. General rules for the preparation of standard solutions.
IIL Description of the most important volumetric methods as yet discovered.

ANALYSIS (VOLUMETRIC). 255

X jkmarahis : deteription^ use, and wrificaiion, — ^Besides the apparatus neeessaiy
ibr ormnazy chemical operations, aucli hjb beakerS) bauinfl, &c., the perfonnance of
TQlmaetiie analTsia requires: (1.) a delicate balance and weights. (2.) Gradnated
ffjaas Teflsels fbr the measurement and preparation of the standard solutions. A balance
18 neceisaiT for the preparation of the standard solutions, and for ireighing the sub-
stances to M analjrsed. A good analytical balance arable of weighing 100 gramme8»
s quite sufficient for both purposes. To those who haye many Tommetric analyses to
perfonn, & small li^t sensible balance with short arms is of great use. Such balances
admit of more repid weighing than can be obtained by the ordinaty laboratory

The absolute magnitude of the units of weight and measure adopted, may of course
be dioeen at pleasure. But the Erench decimal system of weights and measures offers
so many adyantages, chiefly on account of the simple relation which it establishes
betveen the units of measure and weight, that its employment in the sequel in all data
of weight and measure needs no justificataon.

In order to be able to measure the standard solutions accurately, certain precautions
are to be observed which we wiJ now proceed to consider more particularly.

When an aqueous solution is poured out of a vessel, the ressel is, as is well known,
never eompletoly emptied ; a small portion of the solution remains always upon the
the sides^ even after the yessel has oeen long held in an inclined position. In using
a nueasnre for liquids we must) therefore, be careful to note whether the dry yessel,
when filled up to a certain Hue, holds the required volume, or whether such yolume is
delivered fiom the yessel when it is emptied in a certain manner. In the first case
the yessel is said to be graduated for the contents; in the second for delivery
(d ricowdementy. The reading off is performed by bringing the eye and the surfiuse of
the liquid into one horisontal line, and noting what division of the yolumetric instru-
ment is opposite to the liquid surface. Now aqueous liquids which are endosed in
cylindrical glass yessela, always show a concaye surface, which is the more strongly
carved the nazrower the yeeseL But a curved surface is of course opposite to many
points of the scale at once. In order to avoid the ambiguities which are here intro-
cnoed a definite method of reading off must be inyariiwly adopted. The following
has been feund practically the best. A small piece of black paper is fastened a few
jniUimeitres bdow the surface of the liquid by means of a caoutchouc ring; the instru-
mant is brought into an exactly vertical position, one eye is dosed, and the other
brought to the right devation. The meniscus then appears b^ transmitted lights
sharply bounded Mow by a black line, by means of which it is easy to see with
what point of the scale uie former coinddes (see Analysis of Gasbs). In order to
ensoze a fixed point of sight the eye, the memscns, and a distant horizontal line, of
about the same elevation as the e^e, are either brought into one horizontal line, or the
instrument is placed at a short distance before a vertical strip of mirror, and the eye
is bio^iht into sndi a position that the image of the pupil and that of the meniscus
may ccnndde as nearly as possible: the scale is then read off.

It must be mentioned that the yolume of eveiy body yaries with the temperature,
and that consequently the divisioiis on a measure for liquids, as well as the strength
of a standard solution, are applicable for one temperature only. The expansion of the
glass is so small that it may be always neglected in yolumetric analyses. A glass
yessel, for instance, which holds a Uter at 15^ C. contains at 15^ + 10°, one litre +
0-27 CLCL : now 0-27 cc. ; are only the ^^ of a litre. The expansion of liquids is
greater, and must be taken into account in exact experiments.

This is especially to be attended to when volumetric instruments are to be graduated
by determining the weight of water which they hold. In this case the correction for the
expansion of water by heat is not the only one to be made. Since one g^romme is by
definition the weight in yacuo of one cubic centimetre of water at + 4° C, the volume of
a giyen quantity oif water in cc is never expressed by the same number as its apparent
weight in grammes, eyen at + i? C. There is of course no necessity for employing
the Tfol cubic centimetre in yolumetric analyses ; but, as everything connected with
weights and measures should be as precise as possible, we think it advisable to use
the words litre, cubic centimetre, &c, in their strict sense.* Wo therefore eiye the
Ibllowing table, b^ means of which the apparent weight of a certain required yolume
of water may ^uoly be found.

* There are, even in fciratlllc retearchft, eatet fn which tibtolutef^ correct meaturei moat be em.
plofedi for liMtanoe, 1 litre of air of O** G. bai the weight of rs93 grmt., only when iu tension Is
«>qiiiraleut to the preesure of a mercury column 0*76 real metr<>i high, the litre being the volume of a
qiusitlty of water of 4^ &» which balancei in vacuo the kilogramme employid.

256

ANALYSIS (VOLUMETRIC)

The weight of 1000 c.c. of water of ^ C. when detenmned by means of biusa
weights in air of ^ G. and of a tension of 076 metres, is equal to 1000— x grms.

<*»

•11

l-«A

1 »

11»

113

IMS

1-1«

1*14

116

1-21

1-27

1-84

1*43

1.59

1-68

1-76

180

9-04

S-80

a-87

a-55

2-74

9^6

317

3 89

8-88

4*18

4*39

4-67

4-94

♦«

When the barometer stands at 76 + n centim., eyety x is to be replaced by « +
0*014 n. The variations of atmospheric pressure may however be neglected, imilees
a veiy great degree of exactness is required.

If the strength of a standard resolution is luiown for one temperature^ the strength
corresponding to another temperature can only be calculated, if the rate of expansion
by heat of the liquid is known. It would lead to entirely wrong results if such cal-
culations were founded on the known expansion of pure water, as experiment has
shown that even weak solutions of salts and acids expand far more than water
(see Gerlach "Specifische Gewichte der Salzlosungen, &c," Freiberg). As long
as the expansion of the commonly used standard solutions is not directly deter-
mined, it 18 advisable to estimate the stzength of such solutions not only by volume,
but also by weight, which is easily done by weighing a known volume of the liquid
immediately after its strength has been determined. The ratios of the V)dgkt of the
solution to the weight of active substances in it, is of course independent of
temperature.

It is a matter of course that such corrections are appropriate only where the errors
from other sources are not greater than the corrections themselves.

We may now proceed to describe the separate instruments.

1. lEiipetU». — Qlass vessels of forms shown in figs, 40* and 41, provided with a sin^e
mark upon the narrow neck, and which are only graduated for delivery. In usinc
them, they are filled, at a little above the mark, by suction, and then dosed above witn
the forefinger of the right hand. The lower point is brought in contact with a wet
piece of glass ; the liquid is allowed to flow out, by very gentle displacement of the
finger, as &r as the mark ; and the finger is then removed, to allow it to run out into
the vessel employed. The drop of liquid in the point of the pipette is to be kept in
exactly the same conditions as during the marking of the pipette ; t. & it is either
totally neglected, or it is partly removed by holding the point against the wet aide of
the ^ass, or it is to be blown out entirely. If the same method of evacuation be
always feiithfhlly followed, we may assume that, with all thin liquids, equal volumes
remain adhering to the sides of the vesseL

It is convenient to be provided with such pipettes containing 100 cc, 60 ce., 20 ce:,
10 C.C., and 5 cc. Pipettes of 10 and 6 c.c may conveniently have the form of ^. 41,
larger ones the form of>i^.40*. It seldom happens that we have to make pipettes our-
selves, as they may be bought at a low price; but they should always bis verified.
This is easily done by filling them with water of a known temperature, pouring this
into a tared fiask, and weighing. The volume of the water may then be found from
its weight by means of the table above given.

2. Pipettes which are divided throughout their whole length and graduated for
delivery. It is sufficient to have one of 50 cc., which is divided in half cc. (Jiff, 42),
and several of 2 to 3 cc, divided into -^ cc {fig, 43^.

3. Flasks^ graduated for the contents {fig, 44), in various sizes, from -^ litre to
5 litres. They may be easily made by making an arbitrary mark upon the neck of
the fiask, and then measuring the volume by pipettes. It is more exact to wdgh
the contained water. It is convenient if, but not absolutely necesssair that, the volumes
of these fiasks should be whole numbers, such fiasks being used only for the prepara-
tion of standard solutions.

4. For meastiriDg the liquids used in an analysis the tureite is most generally
employed. This is an ingenious instrument invented by Gay'-Lussac Upon a g^aas
tube {fig. 45) about 16—18 mm. wide and 30 centim. long, a narrow tube is fused at d,
carried up dose along the wide tube to about 2 ctm. firom its upper end, and theme
(at c) bent and cut off in the manner shown by the figure. The divisions of \ cc,
begin about one ctm. below c^ and the instrument is graduated '* for delivery." In using
the burette it is washed out with some of the standard solution, then filled to 0 ; the
point c is slightly greased, and the required quantity of liquid is poured out of the
narrow tube.

After some practice it is easy to allow the liquid to flow out either in a

OF LIQUIDS AND SOLIDS.

257

alio diopB. The Tolnme mtiBt notbs read offbefore the snriiice has attained aroDBtant
hei^t. Teoths of cubic centimetre* mty, after aome practice, be eaail; judged of hj
tlH eye in burette" gradnatcd to half cnbic centimetwa. It i« erroneons t« suppOM that
gnater ■ccnisey ia attained by employing naRDver tabes. The gain in accorat^ doe
to the increaBed distance of the diviaiong is lost, becanse in narrower tabes, the
maiUma ia l«a ahaiply defined, and the qnantitj of liqnid adhering to the aidea it
loi coDCtanti A burette of tbe dimconona giTcn, containa 60 to SO cc, an unotint
more than mfficient for moat analyeee : la^ei bnrettes are ioconTenienl. If more
than 60 ce. liquid ara reqoiied in analysia, the greatest portion ia meaaored off in a
pipette. (40*.) and the remainder added from the burette. In easee vhera greater
aeeaacj U reqVKd than can be attained b; the bnrette, the latter is replaced by tlie
nae ot ■rreral pipettes.
Mohr hat sobstitnted fbr Qaj-Lussac'a bnrette a simple dirided tube (fy. 46), pro-

Tided beknr with a caoutchouc tube, which ii
(QueUck-HaJiti) made of brais wire. Where a great nnmber ol

tmd hare to be perftnaad, Mohr'a bnretta is much to be preferred 'to Gsj-Lii

la aeientifie bbonttnies, however, where a greater direni^ of analyses oecnr, the old
fans i* {neferable, inasmoeh as caoutchooe is ac(«d npon by some solutioiii which
an frequently emfJoTed.
The Tarifiotion of a burette ii perfoRoed either hj Iha balance i» by the pipettes

.(1).

XL PreparaUon of lie Slandard SoluUom. — Standard eolations may be divided into
(1) snch as are immediately prepared by weighing a substance of known composition,
diastdnng it and diluting to a certain Tolome ; (2) such as are pretwred by Hiproxi-
mate iniztatc and eobsequent tzact analysis. The Mepanlion of the iint kind re-

VulL 8

258 ANALYSIS (VOLUMETRIC)

quires no deecriptioii. The preparatioa of the seeond niAy be effiBCted by a kind of
successiYe approximation, wmch ia beat deacribed by an exampki

Let it be required to prepare a standard solution of sulphuric acid oontaisiDg t
grammes of hydrate of sulphuric acid SO^H' in 1 litre. The table §^yen by Bineaa of
the relation between the specific graTitj and strength of sulphuric acid aifords the best
means for determining the strength to the fint approximalion. Pure solphiuic acid
(monohydrate, SO*H') is diluted with about its own weight of water; the mixtiire is
allowed to cool, and its q)ecific gravity is quickly and aocuiately determined by mein^
ing 100 cc in a pipette, weighing this, and diviaing the weight (in grammes) by 100. If
the temperature be observ^ the percentage of monohydrated sulphuiic acid (p) may
be determined by tlie table, to within a Hundredth of its true Talue^ Aiwf^ing

to the result of this determination eyezy - 100 ^ q grms. of the solution are di-

luted with water up to 1 litre. From Bineau's table (see Sulphubio Acm) the
specific grayity (^ of the required solution may be seen. To ereiy q grms. of add,
1000 8 — q ^ w grammes of water have to be added. An analysis performed with
this mixture generally shows that it contains not t but t^ grms. in 1 litre. Two cases
are now possible :
(1) <* IS greater than t. It is dear that the quantity ^ of sulphuric add oontamed

in 1 litre is sufficient for J. « (1 + A) litre. With every 1 litre of the mixtnie,
A litre of water must be mixed, in order to bring it to the right strength. (2) f is

less than t From t^ grms. of sulphuric acid only -^ a (1 — A) litre of standard solii-

tion can be formed. Hence 1 litre of our mixture may be regarded as a mixtore of

( 1 — A) litre of right standard solution and A litre of water. Hence to every litre of the

solution as much of the acid of p per cent, must be added as is sufficient to form the

right standard solution, with A of Utre water ; and since by mixing q grms. of the;

per cent, acid with to grms. of water, we had obtained a mixture of nearly the right

strength, it follows that the quantity of strong acid which must be added to every libe

is ( '— q] grammes, neglecting an error which need not be considered, if A is a

small fraction.

After performing these operations, we must determine by experiment how neariy
we have arrived at the required strength, and, if necessair, make a second cor-
rection. If the corrections required are great, it will be alnioet invariably ibond,
on performing the analysis, that the strengSi required has not been exactl]^ attained,
however carefully the mixture of the liquids may have been made. This is the ease
even if the above described approxinuite synthesis is replaced by a theoretieally exact
one, this cause of the inaccuracy being, that in the measurement and mixtore a! large
quantities of liquids, small errors of measurement and losses are difficult to avoid, and
thftt the contraction of the mixture has been neglected. K, on the other hand, the
solution to be corrrected is already so nearly right, that its strength difiers bjr only
1 or 2 per cent from that which is required, uie result will be satisfactory, even if the
volume of the liquid taken was only approximately determined, provided the analysis
was performed accurately, and the measurement of the small quantities of water or
acid which were added, were made with sufficient care.

If, for instance, we consider the case (1^ and assume that the volume of the add to
be corrected was found to bo n litres, while in fact it was n (1 •*- a) litres, the qnan*
titv of water to be added would then be, not n A litres but n A (1 + a). The reanltisg
volume of the mixture would accordinglv be too small bynA(l + a)~nA»nA«. U|
for instance, it is found that a «s ^, which seldom occurs, if moderate care is employed,
and A » yj^, then the volume of the mixture would be n ^^ litres too small, and
consequently the amount of sulphuric add in 1 litte would be too large by about |^
of its actual quantitgr. Similar considerations are applicable to case (2), and lead to
the condusion that in the preparation of large quantities of liquids, aooocding to the
method just described, lai^ measures accurately divided are not neoessazy. Sodi pro-
cesses are conveniently performed in large cylindrical bottles, which are divided dovn
the side with divisions corresponding to entire decilitres. As the liquid in such eaara
is not transferred from one vessd to the other till it is quite prepatred, loss is eaiily
avoided.

The strength of a solution is best noted by giving the number (n) of granuEe|
atoms of the active substance whidi it contains in 1 litre. By "gnumne-atMB
we understand a number of grammes equal to the atomic weight of the substance
(H » 1), lor instance, 108 grammes silver, 28 iron, Z6'6 chlorine, &c It is dear tint
the calculations are hereby simplified. For instance, 1 Utre of solution of silver, eon*

OF LIQUIDS AND SOLIDS. 259

teiiung n atoms («- » x 108 grms.) of silrer ezactlj piecipitat^s n x 35*5 gnnn. of
cUoiiafl^ » X 80 gnus, of bromine, n x 127 grms, of iodine. It is also evident that
ealenlation will be facilitated by making n a small number. If it can be done without
loos of time, it is in fjict adTisable so to adjust the strength of the standard solution

that » a- 1, i ^ ^^

It is of the invest importance that the standard solutions should remain of constant
strength. To ensure this condition, they must be carefully protected fiom eyiqx>ration
and other hurtful influences. Large quantities may be pr«senred in bottles of 1 or 2
litres capacity, proTided with well ground stoppers. Bottles which are not in daily
use shoiUd haTe hare their stoppers greased and bound over with bUdder or sheet
caoutchouc.

m. Deseripium of the most imporiant Volumetrie processes hitherto employed, —
Among the many Tolumetrie methods hitherto discorered, those only are of general
Bdentific interest by help of which the analysis of a whole series of bodies can be made
with one, or at least, a few standard solutions. These alone will be more particularly
considered here. For the many methods applicable in special cases, reference must be
made to the sereral articles of this work.

Volumetric determinations may be classified as follows, according to the principles
on which iStaej are based: —

1. Analysis by Precipitatiott. — ^The quantify of the substance to be determined, is
derired firom that of the reagent requiied to separate it out in an insoluble state.

2. Analysts by Saturation. — The quantity of a base or an acid is measured by the
quantity of acid or base which is necessary to convert it into a neutral salt

3w Analysis by Oxidation and JReduciion, — The quantity of substance to be deter-
mined is found by the quantity of chlorine, bromine, iodine, or o:^gen to which it is
equivalent (reearded as oxidant), or by the quantity of chlorine, bromine, iodine, or
oxygen which it requires to pass fiom a lower to a higher stage of oxidation.

1. Ahjxtbis bt Prbcifit^tiok. — Of the numerous methods belonging to this divi-
sion, we will h«re consider those only which depend upon the insolubility of the com-
binations of silver with the halogens (chlorine, bromine, iodine, cyanogen).

If the neutral or slightly acid solution of a chloride^ bromide, iodide, or cyanide,
is mixed with a solution of nitrate of silver, it is well known that an insoluble chloride
bromide, &&, of silver is precipitated, while a nitrate remains in solution. For

NO*Ag + CONa - CUg + NO*N&

All these silver precipitates have the common property of forming, on violent agita-
tion, a curdy mass which rapidly subsides. Hence it is possible to recognise exactly
the point at which the precipitation is completed. The reactions mentioned may,
therefore, be employed, on llie one hand, to determine chlorine, bromine, &c., by
means of a standard silver solution, and on the other, to determine silver by standard
solntions of chlorides, bromides, &c.

JSkteeial processes for the determination of SydrocUoric Acid and Chlorides.

Meessarjr reagents.

I. Chenueally pure silver in the form of foil or wire.

2l a sUver solution (nitrate) containing ^ gramme-atom (10*8 gnu.) silver in
1 litre. It is easily prepared by dissolving 10'8 gnn. of silver in excess of nitric acid
and df^ntitig to 1 htre.

3. A solution of -jiz gnn.-atom » 1*08 grm. silver in 1 litre.

4. A solution of chloride of sodium of <£ grm.-atom (» 6*85) in 1 litre.

a. 5*85 grm. pure recently fused chloride of sodium is dissolved in water and diluted
Htra.

h. A solution of chloride of sodium saturated at ordinazy temperatures, has a com-
pontioii almost independent of the temperature : it contains in 1 litre, 81 8 '4 gnu. of

KaCL 18*87 cc. ( — ^^^ — J diluted to 1 litre, gives accordingly the standard

floiatioB required.

The chloride of sodium solution must, if properly prepared, be exactly equivalent to
the silver solution (2). We must never n^ect to try whether this is really the case
by the method to be described below, and if necessary to make the proper conrectionB.

6, A solution of chloride of sodium containing ^ gnn.-atom in 1 litre » 0*585 grm.

kikowledge of the amount of efalmne in the substance to be examined. In this case
a weighra quantity is introduced into a bottle of dear glass with a well-fitting stopper,

8 2

260 ANALYSIS (VOLUMETRIC)

diflsolTod in water or nitric acid, and the previoiiBlT calculated quantity of strong
solution of silver (2) is added from a pipette. The quantity of sabstanoe, and that
of the water employed in its solution or dilution, are to be so taken that 100 cc. of
the mixture may contain 0*4 grm. to 1 grm. silver, and less than about 3 gms. of the
dissolved saltk If a mixture has to be examined which is poor in chlorine, this rela-
tion is no lonser possible. In such cases, enough freshly precipitated chloride of nlver
(6) must be added to brin^ the quantity of silver present up to that mentioned. Small
quantities of silver-precipitates disseminated through mvum liquid do not emee that
adherence and consequent tendency to subsidence which is neoeesaiy for the aecimte
performance of this mode of analysis. Solutions which are poor in chlorine, soch as
mineral waters, must be concentrated by evaporation previous to analysis. It is also
advisable in such cases not to employ a standard solution of silver, but to weigh
metallic silver and dissolve it in a minimum of nitric acid.

The mixture obtained as above is now to be violently and contuiuoufily shaken, till
it has lost its first milky appearance, and forms a mixture of curdy chloride of silTer
in the midst of a dear solution. A speedy clarification is evidence of an exoeas of
silver ; slow subsidence indicates the reverse.

As soon as the chloride of silver has sufficiently subsided, | cc. of strong solution
of silver must be added, in order to determine whether chlorine is still present in the
solution. K no precipitation occurs, the } cc. silver solution is neutralised by the
addition of | cc solution of chloride of sodium ; the liquid is then shaken, and \ cc.
of solution of chloride of sodium being added shows whetner silver is in solution. Let
us assume, for example, that the addition of the chloride of sodium has shown tiie
presence of silver in considerable quantity. The amount of solution of chloride of
sodium, which is exactly equivalent to this, cannot of course be known ; but in every
case we are sure of the existence of some m«Timnm value (V cc) which certainly

includes it -- cc of chloride of sodium solution is then added, the mixture is shaken,
2

and J cc of the same solution being added shows whether the precipitation with the

first quantity was complete or not In the first case, j cc of silver are added; in

the second r- cc. of chloride. In both cases, the completion of the precipitation is

tested by the addition of \ cc of test solution. By continually adding half the
possible maximum of the necessary reagents, we soon arrive at a point when leas than
I cc. of one of the two solutions is present in excess. When this point is amved at,
cubic centimetres are added singly of the weaker (^ atomic) solutions, until the last
cubic centimetre leaves the liquid quite clear. This last cc u not at all considered,
and the one preceding it is considered only of the value of } cc In this way, a resalt
is obtained, the error of which corresponds to less than | cc of the weak standard sola-
tion. It is easily seen that a systematic procedure like that given is quite essential, in
order to arrive quickly at a result ; by pJanless addition of standard solutions, we msT
lose much time without arriving at any result. As long as X atomic solutions are nided,
it is scarc^ necessary to wait for a complete subsidence of the precipitate prsrioa^y
formed, inie white cloudv freehlj precipitated chloride of silver is easily distin-
guished from the previously preapitated, tiolet-ooloured, and coagulated chloride.
As soon, however, as we begin to work with ^ atomic solutions, we must always wait
for the complete clarification of the liquid before adding a fresh quantity of solution.
Weak precipitations are best seen by holding the vessel against the light, with a picM
of black paper obliquely behind it The precipitation can be consideied complete only
when the last cubic centimetre of solution gives no more turbidity after } to 1 minntes
standing.

Those who make such analyses for the first time, will do well to place in setenl
flasks some chloride of silver (6) and 100 cc water, then add to the several flabb
J, |, I, 2 milligrammes of silver; shake, and after subsidence add to each flask 1 cc.
of the ^ atomic solution of chloride of sodimn. By this means the judgment u
greatly assisted in the subsequent actual reactions.

Experience has shown that it is not expedient to work with less than | grm. ottShft
at once, and that no greater accuracy is obtained by adding less at once than 1 cc. of
the jli; atomic solution ; the termination of the reaction is thereby only rendered took
indistinct

If it be desired to arrive at the utmost accuracy in such determinatiotts, a aecond
analysis may be made by dissolving 1 grm. or more of silver in nitrie acid, adding the
quantity of substance necessary for its precipitation, as found frx>m the pefv^
analysis, and completing the precipitation bv means of the yjx atomic solution. The
determination of atomic weights, performed in this way by Marignac and Felooze,
shows to what groat accuracy the process may be brought

It has boen hitherto assumed that the amount of chlorine in the substance is ap*

OF LIQUIDS AND SOLIDS.

261

proximatelj kno-wn. If this is not the case, the definite determination must be preceded
bj a tzial upon a small quantity of the substance. The more exact such trial is made^
the quicker will be the performance of the final determination.

The calculation of the analysis is Teiy simple. The number of atoms of silver,
diminished by the number of atoms of ichloride of sodium, added as standard solution,
is eqvAl to the number of chlorine-atoms contained in the substance.

Tnat which is here described for chlorine is applicable, mutatia mutandis^ to bromine,
iodine, and cyanogen.

The dfitezmination of silver by means of chlorine also follows immediately from the
aboTe^ and requires no further explanation.*

2. AsALTSES BT SiLTUBATioN. — All mcthods belonging to this division depend upon
the ftct that potash, soda, ammonia, baryta, strontia, and lime combine easily and
directly with acids, and that the corresponding carbonates are fully decomposed in
cmtact with stronger acids, with evolution of carbonic acid. The solutions of the
Leutxal salts which the above named bases form with strong acids are without action
upon litmus, while the smallest excess of add or alkali is immediately detected by its
reddening or blueing that vegetable colour.

BeagenU, — 1. Pure anhydrous monocarbon4iU ofaodium. If this salt be kept ready
prepared in powder, it must always be ignited before use. Carbonate of sodium, fused
m a plutiTifim crucible, and cast in dabs, is less hygroscopic, but its use must be
avoided, since Scheerer has shown that carbonate of sodium loses on fusing a con-
wderaMe part of its carbonic acid.

2. Standard solution of hydrochloric acid, containing nearly or exactly 36* 6 grms.
Hd (1 atom) in 1 litze. Tlus may be prepared in several ways.

a. The most exact method is to detennine the specific gravity of a sample of con-
centrated pure hydrochloric add, deduce its strength by means of Ure's tablet (see
Htdbocslobic Acm, under CHLOBon), add the proper amount of water and determine
e,gaetlff the strength of the mixture by means of silver solution, as dtiscribed in a pre-
ceding paragraph.

5. A oonoentrated add, whose strength is approximately known from its specific
gravity, is so far diluted that it contains, as nearly as can be effected by this means,
20*2 JMT cenL of HCL If the liquid so obtained be quickly boiled in a narrow necked
flask, or in a retort in contact with platinum (not in an open basin), a time soon
arrives after which h^rdrochloric add and water evaporate in the same proportion in
which they are contained in the residue. If about one half be evaporated we may be
CCTtain that the point mentioned is attained. The percentage strength of the residue
depends upon the contemporaiy barometric pressure, accorduig to the following table,
derived from experiments made on thi^ subject bv Boscoe and Bittmar. (Chem. Soc.
On. J. xiL)

Height of barometer in metres

0-73

0-74

0-76

0-77

0-78

0-79

Percentage strength of )
residue in HCl ( '

20-30

20*28

20-26

20-24

20-22

20-20

2018

It win be seen that in cases where the barometer stands at about 0*76, the percentage
of HCl may, without incurring great error, be taken as 20-24. 180*3 grms. of such an
1 are accordingly equivalent to 36*6 gr. of HCL

€. Coneentrated hydrochloric acid of known specific gravity is so far dilated with water
that it contains rather mors than 36*5 ^. HCl. In a measured (quantity ( Fee.) of this
acid, carbonate of sodium is dissolved in the cold in the proportion of 53 milligrammes
to every 1 c.c of the add. A few grammes of sulphate of sodium are then added,
and the whole is boiled to expel the carbonic acid. The sulphate of sodium is added
to prevent the evolution of hydrochloric add.

Tlie liquid so prqwzed contains, beddes the neutral salts, only the excess of add

* Gar-Lanac** m«thod of determinlog liWer has recentW been invettigated by Mulder (Me Mulder,
** Die alberprobir-methode,** etc., Loipsfg bei Weber). He has made the singular observation, that a
mixtorc of exactly equivalent quantities of Ag and NaCI-solution gives precipitates wth boik reagenu.
Of eittaer of the two aolutlonf a quantity equiralent to ^^ of the silver juat precipitated is to be added,
IfCfaffv tbe formation of prcdplutea ceawa. Stass haa. In the eonrse of his determinations of atomic
weigbts, made a similar obtervation ; but according to him, the limits of the state of IndlflRsrent equl-
itbntnn are narrower. Theae olMervaCfons show that in order to attain the highest possible degree of
aeeoracy, a strictly empirical procedure must be adopted.

t For an add whose strength ia between twenty and thirty per cent, the relation between speciflfi
gravity a, and pereentafe ji, is git en by the equation—

psMOCf-O-l-O-S.
8 3

262 ANALYSIS (VOLUMETRIC)

whoBe quantily has to be detennined in order to find the strength of onr test-add.
For this purpose the nuztore is coloured slightly red with solution of litmiu, and
an arbitrarily diluted caustic soda solution is added while the liquid is hot^ tiU the last
drop causes a decided blue colour (without mixture of yiolet). The quantity of
soda (t C.C.) required to produce the effect is noticed.* On the other hand, a fixed
Tolume (v) C.C of the test-acid is measured, and in exactly the same nuumei^ the
quantity {t} ce.) of caustic soda required for its neutralisation is determined.

From the last test, we haye found that 1 cc. of the arbitrarily diluted soda is equi-
valent to i' '■ of our acid. Hence we had preTiously added ^r ^ c-c* more of this add
than is necessary for the neutralisation of V. 53 milignn. of carbonate of soda, «'. e.

(^ -^ JT )c<s* <'^ ^^^^ ^^ would haye exactly sufficed to neutralise the weigihed
quantity of carbonate of sodium. If, accordingly, we dilute [^ ^ m) ^.c. <>' <^^^ ^

F cc, then 1 ce. of the mixture will contain exactly 1 milligramme-atom of HCI.

In most cases, howeyer, it is better not to perform, this dilution, but to note that Ice

y
test-acid contains / ^^ 36*5 miUigrammes of HCL ^

3. Test Sulphuric acid, — ^It is not necessary to haye this as well as the hydrochloric
test-acid. Nevertheless it has over the latter the important advantage of being wlkoUy
non-volatile when boiled in dilute solution. It can be prepared according to the
method described for hydrochloric acid under (c).

4. Test Caustic soda, which is, volume for volume, exactly or nearly equivalent to
the test-acid. Carbonate of sodium is rendered caustic in Uie ordinary manner, and
so fsx concentrated that the requisite strength is nearly attained. A small quantity
more of mUk of lime is then added, the liquidallowed to cool (the air bein^ excluded),
and the dear liquid drawn off by a syphon. For the exact determination of its streoffth,
60 cc. test-add are poured into a porcelain basin, a few drops of litmus are adued,
and then the soda^solution is poured in from a burette till the colour begins to deepen.
A dedded reaction is recovered by addition of 1 cc of test-acid ; about 2 etins. of
sulphate of soda are then added (if hydrodiloric acid is bein^ employed); the Uqnid is
heated to boiling, and soda is again poured in, till the Uq^uid exhibits a distinct blue
colour. The calculation of the result requires no explanation.

5. Solution of Litmus, — ^Powdered litmils is digested in the cold with twenty tiines
its weight of water, the solution filtered, and so exactly saturated, that 1 ce. of
the litmus solution diluted with about 100 cc water, is turned deddedly red by j^ cc.
of test-add, and decidedly blue by the same quantity of test-alkalL

Acidimetry. — Free adds in aqueous solutions, if these be free from magnesia,
alumina^ and the heavy metals, and are not deeply coloured, may be determined in a
manner which will be suffidently dear from paragraph 4. If hot solutions are used,
the caustic soda may without ii\jury contain a little carbonic add. But if we are
compelled to work in the cold, in consequence of the presence of salts of ammonia, or
because the add to be determined cannot be prevented from evaporating by addition
of sulphate of sodium, caustic soda must be employed which is almost perfectly free
from carbonate But even in such case, the termination of the reaction is not ao easily
recogmsable as when the solution is warm. It is best detected by dropping in the
soda rather quickly and without intermission, till the liquid, after stimn^ wmainw
distinctly blue for some seconds. The gradual change (Mf this colour to violet is no
evidence of the solution not being neutraL Such change depends upon the subeeqnent
action of carbonic acid upon the litmus. In the determination of weaker acids,
such as the organic, the same exactitude of reaction is not observed as occurs in tiie
determination of sulphuric, nitric, hydrochloric, and other strong adds. It must be
also noticed that many substances somewhat modify the blue colour which is the
criterion of completed reaction. In presence of many substances, such as ammoniacal
salts, &c, the change of colour from red to blue does not occur so quickly and decidedly
as when these substances are absent ; and in a few instances, as when acetic acid is pre-
sent, tlie real point of saturation is not reached until after the change of colour has taken
place. In order to render the analysis, in such cases as these, as accurate as possible,
it is advisable to make a control experiment under the same conditions as occur in the
real determination. Thus, for instance, if the strength of an acetic add be required,
it will not be sufficient to make an analysis in the ordinary way, because the nentral,
acetates of sodium and potassium have an alkaline reaction, and this will mask the
true point of saturation ; it is best^ therefore, to prepare a solution of acetic acid of

* The cbsoge of colour ii best icen In a poroeUin bailn, or In a fljuk tUndtng oa white p«per.

OF LIQUIDS AND SOLIDS. 263

knovn stxvngUi — by adding a known quantity of standaid milphtiric acid to excess of
aeetate of sodimn, and to detennine now much standard soda-solution is necessary
to biiBff about a definite change of colour in this acid sohition. The strength of the
8oda-«oration being thus empiricallj determined with acetic acid, the real analysis
can be made without any reference to hypothesis. •

Alkalimetry, — Caustic alkalis and their carbonates are easily determined in a
manner which is so analogous to the method given (2, c.) for the preparation of standard
add, that a foller description is unnecessai^. If many such determinations are to be
made, it is adTisable to employ test-sulphunc (not hydrochloric) add, and so to dilute
the soda that it saturates the test-add, Tdume for Tolnme. If ammonia is to be deter-
mined, the reneutralisation by soda must be performed in a perfectly cold solution.

Baryta, StrorUtOt and lame, and their carbonates^ are determined ezacUr as the
the fixed alkalia. But hydrochloric add must be employed and no sulphate of sodium
can be added, otherwise sulphates of these earths are predpitated, and such preci>
pitates influence the litmus reaction. If only a small excess of add has been used, the

2uantity of hydzocfalorie add lost by a boiling of short duration is vezy inconsiderable.
f tfaia excess of add does not occur in the fiirst analysis, it may be made to do so in a
second one (see page 117).

S. ANA.I.T8I8 BT OxiDATiOK AND Rbductioit. — It is kuowu that most ele-
ments combine in Tarious proportions with oxysen or its substituents ; that lower
oxides or chlorides are oonyerted into higher oxides or chlorides, by the direct or in-
direct addition of oxygen or chlorine ; and that these higher compounds often give up
a portion of their o^^en or dilorine when in contact wiw reducing agents. Amongst
the innumerable reactions of this kind, all those can be employed which occnr quickly,
aind in whidi the tennination of the reaction may be recognised with distinctness.
Amongst the numerous methods of Tolumetrie analysis of thii kind hitherto pro-
posed, we shall mention only the most important These may be diyided into
two daases: (a) those in which permanganic add is the oxidant, — (6) tiiose in
which iodine acts as oxidant.

(a). With PxBifANOAino Acan :

1. Jkteradnaiion of Iron. — If a solution of permanganate of potassiimi be added to
a strongly add and dilute solution of a protosalt of iron, the Mn'O^K gives up | of
its oxygen to the iron, converting it into sesquisalt, and is itself converted into a
manganosom- and a potasdum-salt of the add added ; e. g, :

2MnK)<K + lOSOTe^ + 8S0*H« - 2S0«Mn« + 80*B? + 6(S0*)«Fe« + 8H«0.

The deep purple red colour of the pennanganic add is continually destroyed as lone
as any protoxide of iron is present ; but as soon as all the protoxide of iron is converted
into sesquioxide, the next drop of the reagent, even if the solution is very dilute, gives
a distinct rose-red coloration. Hence it is dear that protoxide of iron may be
determined by means of peimangauato of potassium. A convenient standard solution
is obtained by dissolving about 8 grammes of the commercial crystallised salt in 1 litre
of water; 1 cc. of sndi solution oxidises, according to the relative puri^ of the salt,
from 12 — 14 milligrammes of iron present in the form of protoxide. On account of
tliis uncertainly, imd because the solution gradually though slowly decomposes, a fresh
estimation of the strength of the solution must precede evezy series of iron deter*
minations. For this purpose, 0*6 grm. of pure iron (thin haipnchord wire is almost
perfectly pore) is dissolved in a great excess of pure dilute sulphuric add, the air
being as nr as possible exduded Hohr recommendB the double salt, SO^FeNH* +
SH'O, as a standard. The air-diy salt does not oxidise in air : it contains ^ of its
-weight of iron. The solution is then allowed to cool, and is diluted with water free
&om air to between 0*4 and 0'5 litres. Chameleon solution is added £rom a burette
to this liquid, till the colour of the last drop no longer disappears. From the result
it is easy to calculate how many milligrammes of iron are oxidised by 1 cc of the
chameleon solution. In order now to determine the quantity of iron in a given sub-
stance, so much of the substance as will contain about 0*5 gr. of iron is dusolved, if
possible, in water or sulphuric add ; hydrochloric add should be used only when it
cannot be avoided. If all the iron is dissolved as protoxide, the solution is diluted
to about 0'4 or 0*6 litres, and examined just as was aone in the case of the standard
solution above described. If the iron is present partly or wholly as sesquioxide, this
must, previous to the dilution by boiling with zinc free from iron, be completely
rednced to the state of protoxide. The eduction may be considered complete when
the sohition has become completely or nearly colourless. If any metids such as
arsenic, copper, &c are hereby precipitated, they must be removed by quick filtration
through bibulous paper.
That tiie determination may be accurate, it is necessary — 1. That the solution be

s 4

264 ANALYSIS (VOLUMETRIC)

vezy dilate, in order that the yellow colour of the Besquiozide of iron fonned may not
interfere with the distinctness of the reaction. If hydrochloric acid be present, man
water than usual must in general be added, because in concentrated solutions, hydro-
chloric acid reduces permanganic acid.

Mn*0» % 14HC1 - 7HK) + lOCl + 4Mna

2. An excess of acid — ^if possible, of sulphuric acid — ^must be present The object of
this is not only to make the colour of the sesquiozide of iron faint, but also to prerent
the oxygen of the air and the small quantity of air in the water uised for the dilntioD,
iiom exerting an oxidising action during the operation.

It is scarcely necessary to mention that protoxide of iron may in this manner be
determined in the presence of sesquioxide. The principal advantage of this dete^
mination consists in the fact that the presence of many substances, which often greatly
complicated weight-analyses, does not interfere with its simplicity and accuracy. Eten
the iron contained in ferrocyanides may be determined by means of permanganate of
potassium.

The behayiour of permanganic acid towards protoxide of iron may serve for the
indirect estimation of many substances which are capable of oxidising proto-saits of
iron. It is only necessary to allow the substance to act upon a known qoantity of
iron in excess dissolved as protoxide, and to estimate the amount of protoxide nnacted
upon, in the manner just described. Free chlorine, the active chlonne in chloride of
lime, the higher oxiaes of manganese *, nitric acid, &&, may be determined in this
way. We shall subsequently discuss other and better methods of estimating these
substances, and will not therefore here enter into further particulars.

2. Determination of Copper. — ^The solution of the substance in water or nitric add
is mixed with a quantity of tartrate of potassium and sodium su£Scient to prereDt
precipitation by the subsequent addition of an excess of caustic potash. The alkaline
liquid is heated to boiling, and milk-sugar is added, till all the copper is predpitated
as suboxide. This is collected on a filter, washed with hot water, and digested,
together with the filter, in strong hydrochloric acid and chloride of sodium. The
resulting solution of NaCl + Cu*Cl, is to be diluted and treated with permanganate
of potassium, as in the determination of iron. The filter, if the operation be qoicUj
performed, has no action upon the permanganic acid. Since in this reaction^ 4 atoms
of copper take up one atom of oxygen from the permanganic acid, eveir Tohime of
our solution wiU oxidise as many atoms of copper (31 '7 grms.), as it aces of iron
(28 grms).

6Cu<0 + Mn*0' = lOCu'O + 2Mn»0
and lOFeK) + Mn*0» - fiFe*0« + 2MnK),

3. Determination of Oxalic acid. — ^When oxalic acid and permanganic add an
brought together in acid solutions, the former is oxidised to carbonic add, the latter
reduced to protoxide of manganese, which unites with the acid present :

Mn«0» + bOWO^ + 2S0*EP - 10CO» + 2S0*Mn« + 7HK).

Hence oxalic acid may be determined by means of permanganate of potassium in a dUvte
solution containing an excess of free sulphuric acid, in a manner exactly similar to
that described under iron. For the determination of the permanganic acid, either inre,
air-dried, ciystallised oxalic acid, (?W0* + 2H*0, or pure iron, is employed. A Tolone

of test-solution which oxidises x atoms {x . 28) of iron, will convert - atoms of oxalie

acid (x : %\'6) into carbonic acid and water.

The behaviour of permanganic acid towards oxalic acid may be employed for the
valuation of commercial peroxide of manganese : 1 grm. of the very findp powdered
peroxide is mixed with a weighed quantity (about 1*5 g^mme) of ciystailised oxalic
acid and a considerable excess of pure dilute sulphuric acid, and warmed till the
peroxide of manganese is decomposed. Water is added, the solution allowed to cool,
and the excess of oxalic acid determined as above : 1 atom of peroxide of manganese
transforms 1 atom of oxalic acid into carbonic acid :

Mn«0* + C«H O* + SO*EP - SO«Mn« + 2C0« + 2H«0.

(5). Methods iir which Iodinb acts as oxiDisiira agbkt. — Iodine in
aqueous solution, in presence of oxidable substances, often acts upon the dementa of
water so as to form hydriodic acid with its hydrogen, while the oxygen acts upon the
substance present. Now as the smallest quantity of free iodine may l^ recognis^ by its
property of blueing starch-solution, whereas hydriodic acid and the iodides are without
action upon starch, the substances mentioned may often be determined by mixing their

* The detennlnatloD of nitric acid bec&met exact only when the reaction takei place in mh atmo*phvt
or hydrogen, but thii precaution being taken, N*0' oxidise* exactly ISFe. (Freseulua.)

OF LIQUIDS AND SOLIDS. 265

aqaecus solutions with starch-solntioii, and then adding a standard solution of iodine
in iodide of potassium, until permanent blue coloration occurs. In order that this
reaction may succeed, the substance to be oxidised must, even in Tenr dilute solution,
possess the property of decolorising the iodide of starch which has been locally
formed. For examples of determinations of this kind, we wiH take the following.

Hjfpondpkurous acid, as potassium-, or sodium-salt, in neutral or alkaline solutions
(made alkaline by bi carbonates of the alkalis), acts upon iodine in such a manner
that tetzathionotes of alkalis and metallic iodides are produced, e,g. :

2SH)^a« + 21 - 2NaI + S«0«Na».

•

Jrwadotu add, in the form of an alkali-salt, is converted by iodine into arsenic acid,
in a solution made distinctly alkaline by carbonate or bicarbonate of an alkali-metal.
Iodine must be added till the iodide of starch formed is no longer decolorised on the
addition of bicarbonate of sodium ; 4 atoms of iodine (508 pts.) oxidise 1 atom of

arsenioos add (198 pts.) :

As«0> + 41 + 2H«0 - 4HI + As«0».

Sulpkurtna add, may be determined like hyposulphurous acid in solutions rendered
feebly alkaline by an alkaline carbonate. The product formed is sulphuric acid:

SO* + 21 + 2H*0 - 2HI + SO*H«.

If we endeaTonr to determine free sulphurous acid by iodine, yery direii^nt results
toe obtained when the solution is strong. In such cases, the quantity of snl-
phuztras acid oonyerted into sulphuric acid yaries yei^ much, according to the quantity
of water present and the rapidity^ with which the iodine is added. I^ howeyer, beforo
adding the iodine, the solution is so far diluted with water free from air, that less than
0-4 grm. of sulphurous acid is contained in 1 litre of water, the reaction, 21 + 2HH> +
SO* « 2HI + SO*H», occurs with perfect regularity.

The dicumstances under which this reaction takes place, were determined by
Bun 8 en (Ann. Ch. Pharm. Ixxxyi. 266), and applied to a series of yery accurate yolu-
metrie determinations, the most important of which we shall here explain.

Jnalyees by means of Iodine and Sulphurous Acid,

Seaaents. 1. Pure iodide of potassium. 2. Pure hydrochloric acid. 3. Freshly

piMMtfed, thin, yeiy dear starch-solution.* A dilute solution of iodine of potassium,
moed with starch and hydrochloric add, must giye a mixture which remains colourless

for seyeral minutes.

4. A standard solution of iodine in iodide of potassium, 6 grms. of commercial
iodine, and 10 to 12 grms. of iodide of potassium, are dissolved in about 20 cc water,
and as soon as all the iodine is dissolyed the solution is diluted to 1 litre.

6, A solndon of sulphurous add in distilled water. This must be so diluted that
about 10 Tolumes of it are necessary to decolorise 1 volume of the iodine-solution (4).
This solution should be prepared in quantities of 10 to 20 litres, and allowed to stand
about an hour exduded from the air, before use, so that the oxygen contained in the
diasolred air may be absorbed by the sulphurous acid. It may be advantageously
kept in an earthenware vessel, provided with a tap at the bottom, and a fine drawn
cHrt tube above to allow the air to enter. The strength of such a solution may be
considered as constant during the performance of one analysis.

The first question is to determine exactly the strength of the iodine-solution, already
approximately known. If we had a small quantity of perfectiv pure iodine of known
wnght, this might be easily done by comparing such iodine with the standard-solution

anhydrous bichromate of potassium
evolved chlorine in a solution of iodide of potassium (for one part of the bichromate
about 20 parts iodide of potassium are employed)- 1 atom ( 294-8) of bichromate
liberates under these circumstances 6 atoms of iodine (6 x 127*0) :

Cr«K*0» + 14HC1 = 7H«0 + 2KC1 + 2Cu*Cl* + 6C1
6C1 + 6KI « 6KC1 + 61

In order to perform this operation without loss, the following method is adopted.

On a glass tube of about 4 — 6 mm. internal diameter, a bulb of about 30 cc. capacity
is blown, and a flask is thus obtained of the form shown in Jig, 48. To a short piece
of the same tubing, a longer and narrower tube is fused, drawn out at d, and bent as
ahown in the figure. K^e neck of the flask and the adapter-tube be ground flat and
connected with caoutchouc, in such a manner as to bring them close together, an appa-

• SUrcb-Mlatioo, when Altered and uturated with chloride of todlum, may t>e kept a long time with-
out decompotltloa. (Mohr.)

266

ANALYSIS (VOLUMETRIC)

ratuB 18 obtained for 'the evolution of chlorine, which is scaroelj inferior to one con-
sisting wholly of glass. The caontchoiic tube befiire use mnst be freed from adhering
Bulphur by boiling with yeiy dilute caustic soda and thorough washing with water.

A retort of about 150 cc. capacity ( J^. 49) serves to hdSi the 8oh£on of iodide of
potassium. The neck of the retort is widened at a, to reeeiTe any solution driren
back by the expelled air. In order to make the determination, we bring the bi-
chromate of potassium into the iiask, which is then filled to | with fomix^ hydro-
chloric add ; the deUyeiy-tube ia attached, and placed so &r in the retort ^Uled np
to the commencement of the neck with iodide of potassium solution), that the chlorine
which is not immediately absorbed must collects at b. The flask is first gently heated
till tiie decomposition is complete, then more strongly, in order to drire orer every
trace of chlorine into the iodide of potassium solution bv means of the gaseous water
and hydrochloric acid. The retrogression of the iodide can scarcely take plaee if
some care is taken, because it can only occur very riowly, in consequence of the small
volume of tiie apparatus and the fineness of the point d. After the hydroehloric acid
vapours have be^ evolved for about five minutes, it may be assumed that all the
chlorine is expelled. Without discontinuing the boiling, the deliveiy-tiibe is witli-
drawn from the retort* and the vapours are conducted into some fresh sohition of
iodide of potassium, the boiling being continued for a few moments longer. If this
solution remains uncoloured, the operation may be regarded as successfoL

The contents of the retort (coloured deep brown by iodine) are quickly cooled, and
poured out into a beaker glass, and portions of 400 to 450 c.c of the dilute suiplniiotu

acid are suocessivefy added, without

Fig, is.

Fiff.id.

loss of time, until the Uqmd is
colourless. The measurement of the
sulphurous acid is effected in a flask
which contains, up to a mack on its
narrow neck, from 400 to 460 cc,
but whose capacity need not be ac-
curately known. The flask is rinsed
out with the sulphurous acid, filled
up to the mark, and emptied in a
definite manner, which shonld be
strictly adhered to during the same
analysis. Direct experiments hare
shown that the volume of the liquid
delivered is sufficiently constant.

The liquid decolorised by sol-
phurous acid contains an excess of
this body. Starch and then normal
iodine- solution are therefore added
tUl blue coloration occurs. X«et the
volume of the latter necessary for
this be f ac. Immediately after-
wards, one of the measures of sul-
phurous acid previously employed is
taken, and the volume {i cc) of
standard iodine-solution determined
which is neeesBary fbr its oxidation. I^ then, the number n of the fiasks of sul-
phurous add which were added to the iodide of potassium solution from the retort
has been noted, the strength of the normal solution may be eauly calculated.

Let us call, for brevity, the contents of the fiask the " volume." From the resolt
of the determination just given, we find that nt cc. normal iodine-solution were
necessary for the oxidation of n volumes sulphurous acid. For such oxidation, t^ cc
of the same iodine-solution, together with the quantity of iodine produced by the
distillation of A milligrammes of bichromate of potassium with hydrochloric acid, were

also sufficient. This amount of iodine I A, j millg. is therefore equivalent

to (nt — t^) cc. of iodine solution. Hence 1 cc of the latter contains

^ X 8 X 127
147-4 (nt - <>)

A X Z

milligrammeB of free iodine, or
SB T milligramme-atoms of free iodine.

147-4 (nt - <»)

Inasmuch as all subsequent analyses depend upon these determinations, the latter
must be performed two or tnree times, and the mean taken of the remits (which should

OF LIQUIDS AND SOLIDS. 267

nmdj agree). The moet Tarious analyses may be performed by means of an exactly
deteniined iodine-flolntion. We will take the following examples.

1. The determination of «tt/pAurot», k^fposulpkitrouSf and artenioua acids has been
already described.

2. StdpkttrHted kjfdroaen may be determined similarly to sulphnioos acid, in a
sdittion containing less tnan 0*4 gnn. in 1 litre; but from some unexplained cause the
resolts are only approximately exact. The reaction vhieh beve occuxs is zepraeented
by the equation: H'S -i- 21 - 2&I + a

S. I>eteimination of free lodmt, Bromwe^ and ChUrine, Iodine dissolves directly in
a solution of iodide of potassium ; bromine and chlorine form bromides and chlorides,
libeniing an equivalent of iodine. The quantity of the latter is determined by adding
excess of sulphurous acid (n volumes), then starcn, and Anally solution of iodine (fi cc),
until the ireU*known reaction occurs. If now t cc of iodine solution were neoessaxr '
for the oxidation of 1 volume of sulphurous acid, the liberated iodine must be equi-
valent to n< — t' of iodine-solution, or the chlorine^ bromine, or iodine must have the
vafaie of (fi/ — <')r milligramme atoms.

4. Detennination of ^e Oxidea of Chlorine which contain Uu than Jhe atoms of
Oryfftn for two atoms of Chlorins.^ All these substances an decomposed by iodide
of potaaaiDm and hy drochlorie add in the following way :

any +2*Ha - «hh) + 2{x + lyx

The firee iodine is determined according to (3). Commercial bleaching powders are
tested for the amount of active chlorine which they contain, by treating them with an
excess of iodide of potassium and enou|^h hydrochloric acid to cause a slightiy acid
reaction. Each atom of active chlorine liberates an atom of iodine :

GaClO + CaCl -¥ 2KCi + 2KI » 2Ca01 -f H*0 + 2KC1 + 2L

5. Chlorates. — ^According to Bnnsen's experiments, these salts when distilled with
hydrochloric acid do not give up free o^^gen, but only free chlorine and lower oxides
of chlorine. If the products of distillation be received in excess of iodide of potas-
sium, the final result is the liberation of 61 for ClO'H. Such iodine may be deter-
mined according to (3).*

6. /Mioses.— -One atom of free iodic acid decomposes with 5 atoms of h3rdriodic acid
to 3 atoms of water and 6 atoms of free iodine (HIO* + 5HI t- 61 •«• 8HH)^.
This reaction may serve for the determination of iodic add. On the other hand,
pore iodate of potasdum may be convenientiy employed for determining the strength
of the normal iodine-solution. (B u n s e n.)

7. MetalUe oxides containing a portion of their oxygen in sodi a state that it liberates
an equivalent quantity of chlorine on boiling with strong hydrochloric add, may be
determined by boiling them with fuming h^W)chloric acid, collecting the chlorine in
iodide of potasdum, and determining the iodine set free according to f 3). To this
dasB belong all peroxides, the higher oxides of mansanese, chromic acid, and other
metallie acids, ice. &c. In analydng manganic oxides, a weak hydrochloric add of
about 30 ver cent, must (exceptionally) be employed, because on using frmiing hydro-
chloric acid, dilorine is apt to escape. The calculation scarcely needs any expumation.
The amount of free chlorine, if we retain the usual symbols, amounts to {nt — t^)T
milligramme-atoms. Half this number of atoms of active oxygen are therefore
pieeent, and l^ese stand in a known simple numerical relation to the number of atoms
of the substance to be determined.

8. Metallie oxides which may be peroxidised by chlorine, are determined by boiling
them with a weujfaed excess of bichromate of potassium and hydrochloric add, receiving
the excess of ch&rine in iodide of potasdum solution, and determining it according
to ^3). As an example of the calculation, let us take the determination of protoxide
of iron. XiCt the amount of bichromate of potassium employed be A milligrammes ;

milligramme-atoms of free iodine. If mstead of this, we actually find only {nt — t^) T
milligramme-atoms^ then:

BiiIligrainme-«tom8 of chlorine must have served for the oxidation of the iron. Or :

j-ny^-(«^-<')Z'[.2x28

milligrammes of iron must have been present.

* If perchloric add wercprocliicedin thit reaction (and Its entire tbtenee has not jet been prored), thh
wtbod, M S|iplted to chlonlM, would net gif a accurate roulta. Bnnien, in hla Memoir, giret only
Qoe detarmlnaUoQ of chlorate of potaiijum. which, however, agrees very well with theory.

268 ANALYSIS (VOLUMETRIC)

Havinff become acquainted with the most important volometric methods ve may
now consider a point in connection with the calcolation of the resoltM. If a loDgaoies
of determinationB of the same kind have to be performed BnooeflsiTely, the time neces-
sary for their calculation is of great consequence, and it is important to consider tiw
liest waj of simplifying it as much as possible. This may generally be effected by lo
choosing arbitrary magnitudes which occur in the calculation, as the wei^t of the
substance, the strength of the normal solution, &c, that the mathematical expression for
the result may be as simple as possible. The following examples will illustrate this:

1. A number of soda determinations hare to be made with an add which contains

1'017 milligramme-atoms of sulphuric acid (SO*H' « 98) in 1 c.c If a milligrainmes

of soda be employed in tiie anaiysiB, and if the volume of the acid used in neutralisation

V T XI. .1. J ^ . A? X 1017 K 62 X 100 . . , ,

be k c.c then the soda oontams per cent, of anhydioiis

soda (Ka'O). If now 1-017 x 62 x 100 milligrammes of soda be weighed each time,

then the fraction * is « 1, and theperoentafeof thesodajncanstie

soda is B k, that is, simply equal to the number of c.c of the standard add nsed.

2. In the previous division (8), we have considered the determination of iron by
means of iodine-solution and sulpnurous acid. If c milligramme of the iron con^wund
be employed for the analysis, the percentage (x) of iron is derived from the formnla

X mm

2 x28 X IW \^-(nt - fi)'l\

in which the letters have the signification before given. It is clear that the calcnlstioa
is considerably simplified if (1) 7 be a round fractional number, for instance, ^
(2) if ui be made a simple multiple of 147*4, for instance, 6 x 147*4 milligrammes.
(3). By taking « so as to be a simple submultiple of 2 x 28 x 100, for instanee,
30 X 28 millignunmes. — ^W. D.

AVA&T8ZS (VOKUMBrKZC) of CMUiBS. This branch of analysis ha
of late attracted mudi attention from chemists ; but the chief improvements and de-
vdopments relating to it are due to Professor Bunsen. Previous to his researches
on the subject, the processes adopted for measuring and analysing gases were so ex-
ceedingly imp^ect, the inaccuracies introduced so numerous, and even the reagents
made use of so defective, that only the most variable residts could be obtained; noir,
on the contrary, gases may be analysed with an accuracy which cannot he eqoslled
in any other branch of chemistry. So far indeed as accuracv and simplidf^ of mani-
pulation are concerned, Bunsen's method leaves little to be aesired ; but it is long and
tedious, even a simple analysis requiring some days for completion. The neoessaiy
calculations for the reduction and correction of the observations are also numerous and
require considerable time and attention.* To obviate these inconveniences, serenl
methods have of late been proposed, by which the composition of a gas may be accn-
rately determined in a very much shorter time, and without the calculations fozmeiiy
necessary.

The arrangement of the subject adopted in this article is : first a description of the
apparatus and general method proposed by Bunsen ; then that of the more recent and
expeditious methods ; and lastly, the processes, which to a certain extent are common
to all tiie methods, for separating and estimating the difierent gases.

According to the method of Professor Bunsen, the gases are collected and measai«d
in graduated tubes over mercury. For this purpose, two straight glass tubes are used ;
one of them, which should be about 250 mm. long and 20 nun. in dumieter, is termed the
absorption-tube, and the other which is from 600 to 600mm. long, and 20 mm. in
diameter, is termed the eudiometer (figs. 50, 61). The absorption-tube is pro-
vided with a sort of lip as shown in the figure, to enable the operator to pass the gas
easily out of this tube mto the eudiometer. As this latter tube is the one in which the
combustible gases are exploded, two platinum wires must be frised into the dosed end
of it, for the passage of the eleetric spark. This is done by strongly heating the end of
the tube in the blowpipe lamp, and then just touching it at the point where the ^rireis
to be introduced, with a hot platinum wire ; to this the glass strongly adheres, and by
this means is drawn out to a fine thread, which, on being cut off dose to the eudiometer,
is found to be hollow ; through this hole a platinum wire is introduced, and the glass
carefully fiised all round it. A second platinum wire is then by similar means fused into
the opposite side of the eudiometer. These wires should not project straight across the
tube, as they are then apt to become bent and moved fix)m their proper distanee

* For a more detailed account of Bunsen** method of analyilt, and for ftirthcr Information oa
gMometry in gen<>rAl, we would refer the reader to Buns'-u't ^* Gatometrjr," translate bjr RoMoe.
( Walton and Maberly.)

OF GASES.

269

tptrt on filling the tube with merctur; — if straight, they would also prevent the
eadiometer from being properly deaned : it is consequently most conyenient to have
tbem bent so. as to lie a^|ainst the rounded top of the eudiometer. The ends of the
wires ahonld be at the distance apart of about 1 to 2 m.m. In order to ascertain
whether the wires have been properly fused in, so that the con-
tact of the plalinnm and g^aas may be perfect and no probability Fiff, 60. Fi^. 6l»
of leakage can occur, the eudiometer is filled and inyerted in a
metcnxytzough, and Uien, while held in a vertical position, sharply ^^

rapped against the bottom of the trough; this communicates a more- ~

ment to the mercury in the tube, which sinking for a moment leaves
a vaenum at the top, whereupon if the wires are not fused in abso-
lutely aii^ti^ht, a row of small bubbles will be seen rising from the
defectiTB pomt.

Having proved the tube to be air-tight, the next operation is to
etch, by means of hydrofluoric add, a millimetre scale on it and
on the absoiption-tube. This may easily be done by the following
process, whicn was also suggested by Professor Bunsen. The tube
to be etched is heated np to the temperature at which bees-wax
melts over a fire, being ndd by means of a stick which passes
through a ooA fitted into the open end of it. The tube is then
covered as uniformly as possible with mdted wax, which is best
done by p^^'ntjng it all over with wax, by means of a brush
or feather. During the cooling, it should be continually turned
round in the hand, so as to keep the wax equally distributed over the
whole snr&ce. If ttte tube wnen cold is found to be completely
ooveored with wax, it is then ready for etching.

Fiff^ S2 represents the apparatus used for this purpose, a b is a
table or huge board, with a groove running along it of such size
that the tube to be graduated will lie easily in it ; d d represents
this tabe, which is firmly hdd in its place by two brass plates e e,
acrewed down upon it. At the other end of the groove, a standard
tube bb, ia also firmly fixed by means of a brass plate, and on this
tube is the scale which is to be exactly copied on the wax covering
the tube d d. This is done by means of a long bar of wood, to one
end of which is fixed a sted point, and to the other a kind of knife.
The rod is held by the ends as shown in the figure, the right hand
guidinff the knife. In using the apparatus, the steel point is
alloweS to fidl into one of uie divisions on the standard tube,
which are purposdy deeply etched, and while it is hdd there, a cut is made by means
of the knife on the wax covering the tube. The length of this cut, and the consequent
breadth of the scale, is regulated by the distance between the two brass plates e e.
As aoon as this first stroke has been made, the wooden rod is gently moved a

Fiff. 62.

i!iiiniiiiuiiiiJitim\iiuuiutmiiiuimiuii<

liiiiiiiiiiiiiiiiiiiiHiiiiuiiiiiiiiiiiiiuiuuuumiuiUi

litde forwards until the point falls into the next mark on the standard tube ; then
a second cut is made in the wax, and so on. The sted point should always rest
against the brass plate o e, whidi will then serye to keep it in the same straight line.
In Older to render the reading of the scale more easy, it is convenient to have eveiy
fifth stroke on it longer than uie others ; which is easily accomplished by having slits
made in the brass plate e, at the distance of 6 mm. apart, so that when the knife
arrives at one of these slits, it passes f^irther across the tube than in other cases.
Before removing the waxed tube, it must be carefully examined, and if any fidse strokes
are seen, they may be removed by applying a thin heated wire to the spot : then,
when the wax has cooled, a fresh stroke may be made. The tube is now removed, and
at each centimetre, the figures indicating uie number of millimetres from the top are
scratched in the wax by means of a needle. If any of the wax has been removed from
the tube by the pressure of the brass plates, these places must be caiefUlly re-covered,
and the tube is then ready to be exposed to the hydrofluoric acid.

270

ANALYSIS (VOLUMETRIC)

Fig,6Z.

This is most oonyenientiiy done in a kind of long nairow leaden dkh. Powdeml-
floor-spar is strewed along the bottom, and a laige esoess of snlphniie add added;
heat may then be applim. As soon as the gas comes off abundantly, the lamp is
remoTed, the tabe lua over the dish resting on two wire sappotts, and Ihe Yhole ■
covered with a sheet of paper. When the tnbe has remained there about three minaitflB
it should be removed and one of the dirisions examined by passing the nail over it,
to ascertain to what extent the etching has taken place. In from thne to six minatei,
most tabes will be sufficiently acted on. The etcmng may also be accompUahed with-
out applying heat to the hydrofluoric mixture ; in this case the tabe must be left in
contact with the acid for several hours. This latter method yields peihap the most
distinct eraduation. In order to render the scale still more dear, it should be nbbed
over with a mixture of vermilion and copal varnish, which fills and hardens in etch of
the divisions, rendering them verv evident to the eye.

Since no tube is of precisely the same diameter for any length together, the scale
thus etched bears evi^ntiy no constant relation to the cubic capacity of the tabe.
In order then to ascertain to what extent the cajMusity varies in diffarent parts ai tabe
equal volumes of mereuiy must be poured into it, and the space they occupy read off
on the scale. Fig. 63 represents a convenient form of apparatus for always obtaiiiiiig,

these equal volumes of mercoiy. a is a small gbas
tube fixed in a handle and capable of opntainiog
about that amount of mercuzy which is reqoized to
fill the eudiometer through 20 mm. of its length.
0 is a glass plate, on the top of which the two aidi
of a strip of caoutchouc are fitstened by sealingwix,
so as to form a loop whidi is slii^nd over the
thumb. By turning tne stopcock, ^^ich aUom the
mercury to flow horn, the reservoir 6, the g^
measure, the top of which most be ground perfeetlj
even, is completely filled, and the mercoiy rises
in a curve above the top ; on depressing the plate e,
the excess is e3q)elled and the tube obtained pe^
fectly full : care must, however, be taken that no
bubbles of air remain adhering to the sLdo. In
filling the measure, it is well to allow the end of
the tube e to rest on the bottom of it, and only
gradually to withdraw it when nearly Mi of me^
cuiy. The tube to be calibrated is firmly faehl in
a perpendicular position by means of a damp, and
the measures of mercury are then carefoUy poured
in, any bubbles of air which may remain adnenng
to the tube, being removed by means of a small stiA
7 or piece ctf whalebone. After each addition of
-=^^ mercury, the height which it occupies on the scale is
read on. In order to prevent errors firom parallax,
this should be done by means of a tdescope fastened
to a damp which moves on a perpendicular support.
In all readings-of^ it is the position of the higfaert
part of the mercury meniscus on the scale that is observed. This process for deter-
mining the cubic capacity of the tube should always be gone through twice, and the
mean of the two series of observation taken as the basis of calculation. An eaunple
will best show how these calculations are made and the results tabulated. The height
of the mercury in the tube after the successive additions of the measured quantit]^ is,

diff.

^^•^ I 18-6

6015 - .^^ ^^

In the second column is expressed the height which this constant quantity of m^^

cury occupied. This varies of coxurse with the capacity of the tube, increasing as the

tabe diminishes, and diminishing as the tube increases in size. One of these di&renoes,

generally the lajgest, is taken as the standard, say 13*9, tiiat is, 13*9 volumes of me^

cury have been found to occupy on the scale :

mm.

1 X 13-9 - 9-1

2 X 13-9 - 23-0
8 X 18*9 - 36-6
4 X 13-9 - 6015

UIIMIIIIIIIIIUIIIIIIIIIIIIIMIfihllinilllll^tl

OF GASE&

271

This gives the Mlattre Talues of the scale at these partieQlar points, and it only

nmains to interpolate the lespectrre Talues of each diTision between these snocessiye

points. In the fiist instance, between 9*1 and 23*0, each millimetre will represent

enctly 1 Tolume of mercniy; bnt in the second instance, where the 13*0 toIs. of mep-

oiny oeeopj only a length of 13*6 mm. where the tabe in £MSt is broader, each division

13*9
win hare a Talae eqnal to ^^ « 1*022, and in drawing out the table^ this number

most be added to each millimetFe between 23*0 and 36*6. Again, the number to be

18*9
added to each dirision between 36*6 and 50*16 is -• 1*025. In this way is

formed a table, which, although perfectly arbitraiy, is relatively correct, tiieamonntof
error arising fhmi the alteration of the size of tne tube between each leading^off of
the height of the metcozy, being qnite inappreciable, when the measured qnantity does
not extend over more than abont 20 mm. The following table is calcnlsied from the
foregoing observations. In the first oolmnn, the divisions on the scale are given, in the
second uieir arbitrary value.

13*80

28*82

4417

14*80

29*84

45*20

15*80

30*86

46*23

16*80

31*88

47*25

17-80

32*91

48*28

18*80

33*93

49-30

19*80

34*95

50-33

20*80

35*97

51*36

21*80

36-99

52*38

22*80

38*02

53*41

23*80

89*04

54*43

24*80

4006

55-45

25*80

41*10

26*80

42*12

27*80

43*15

As it is always the highest point of the meniscus of the mercuiy that is read off
on the scaler bota in calibrating the tube and afterwards in measuring the amount of
gas it may ff>F»t4M", a slight correction must be api^ed to every obser^tion to correct
the enor which would otherwise arise from the convexity of the mercury. By re-
ferring to Jiff. 54, it will easily be seen how this error arises. (1) In calimnitinff the
tube lifao tf* represent the meniscus, it is the number on the scale coinciding with the
Hne e e\ that is read off, although the tube is not full up to that point by the space
ae e' a* ; and (2), in analysing a gas, when the tube is in the reverse position, the same
number on the scale would be read (^, although the meniscus of the mercury oyly
eoineided with the curve n o n\ leaving in &ct a space as much below o c' unoccupied
by mercury in tiiis instance^ as was leH above it m the former one. Hence after re-
fttriiig to the table to ascertain the relative value ot any readin^-ofl^ there must be
added to it a quaatitr equal to the whole space ana* n\ What this number is, which
has always to be added can easily be ascertained by the following process. The
codioiBeter being fixed in a perpendicular position with its dosed end downwards^ a

272 ANALYSIS (VOLUMETEIC)

email qoantitj of mercnir ii poored into the tube, and ita height eueMf m
a few drtpB of a ililut*! sdution of corroaiva luhlimale are now tAAed, ihe efl^
whidi ia eDtirelj to dcstioj the memscas, and render the mrbce (rf Uie me

perfectly flat: die height x x* at which it now Ettmda in the tabs ii Mad oC Tviwlht
diSereDCe of theee two readings ia then the qnanti^ to be added to nch obtmUJat
after refeiring to the fable of capadtiae.

The most coBvenient form of mercury-tioagh is that propoaad hj BmiMi, aiid

repreaented in Jig, EG. It ij about 3G0 "itp, long, and 80 nun, broad. Ths tiro ailn

o 0, are made of thick slasa plates, and the lower part of it j^ is formed out of a aa^t

piece of wood hollowed out. In order to economise the amount of mimuT

i^, 6t, Deceaaaiy, the inaide of the troogh ia made lomid at the bottom iutad c^

being square, a forma a convenient anpport for the ecdiometer. Brfon

naing the trough, it ebould be well rubbed with corrosiTe imbhmile ud

mercury, or elae amall bubbles of air are apt to remain adhering to tht wood,

and may afl«niarda rise into tbe eudiometer.

A good tbenaomeler and barometer am of course indispensable. Tht
len^h of the degrees on the thermometer scale shoald be iucb IhU &t
position of the mercury, to a tonth of a degree centigrade, may be euilj
lead off by meana of the telescope. The barometer generally uieil ii M
the ayphoD form {fig. 66). The scale ia etched od the glue ud tbe
dosed end is bent as shown in the figure. So that the scale on the two linibi
is in tbe same straight line. The thermometer I, is placed in the opa
end of the barometer, and held in its place by a small piece of whalebone
which acts as a spring. Before reading off the height of tbe buomebi ud
thermometer, the latter should be genllj moved a little up and don, thm
communicating to the loerem^ in the barometer a slight moremeot, ^t^
OTcrcomea any adhcmon between the mercury and the glaaa.

The kind of room which is uaed aa a gas-laboratory when this moeai
u adopted, ia a point of tcit considerable importance. It abonld nsTe i
northerlj aspect, and the waUs should be thick ; in fact, the room mait I*
protected in every way from sudden changes of temperature. The moau}'
trough and barometer should stand on a table immediately ia fivot of >
mndow, if possible a double one. The table is provided with a rim noad
it, in Older to prevent the loss of any mercury that may happen to be ipH
upon it. Between every two operetiona in the analysis, at least half inbnir

lo the top of the eudiometer ; the mercuty then rises gradually, the funnel being

ANALYSIS (VOLUMETRIC) OF GASES.

273

Fiff.67.

kept ion, and expels the air yery thofronglily firom the tabe. A small bubble of air
will however senerally be found to remain in contact with the platinum wires in the
eodiometer ; utis must be got rid of by placing the thumb over the open end of the
tube, and holdinff it in an inclined position ; then, by means of a sudden jerk, the
bobble may be <utached from the wires, and by merely inyerting the eudiometer,
alknred to eeeape.

AH the readinpiMif!^ as before stated, are made with the help of a telescope, which
should be at a distance of seyen or ei^t feet from the tubes. Care should always be
taken that the division to be read off is nearly in the middle of the field of the tele-
scope, cr a slight error may arise from parallax. It is tiiorefore convenient to haye
the telescope proyided with a cross wire.

At «aeh stage of the analysis, four obsezrations haye to be made : 1st, the height
of the Tuaeury in the gas-tube ; 2nd, tiie height of the mercury in the trough as

measured on the scale of the ^as-tnbe ; 3rd, the tempera-
tare ; and 4th, the atmoephenc pressure. The barometer
and thermometer are always read off last ; for before doing
this, it is necessary to approach the table in order to moye
the thermometer, as before described, and the heat given
out from the body would increase the volume of gas in the
tube. In order to read off accuratdy the level of the
mercury in the trough, it is necessary so to place a piece
of white paper between the glass side of the trough and
the tube, that it may reflect the light from the window on
to the softle. Fiff. 67 shows how this is conveniently ar-
ranged, the scale being seen through the slit m,

iLfter each operation in the analysis, before leaving the
tubes to cool, a n^id observation should be made with

-^ 1 the telescope, in order to see that the scale on the eudio-

H ^ meter is in its right position, passing apparently exactly

^Jp^ through the highest point of the meniscus, and also that

^^B^ K ^^® height of the mercury both in and outside the tube

can be easily read off.

In order to render the observations thus made at different
temperatures and pressures comparable, they must be re-
duced to a oommon standard, the one generally employed being dry air at Ql° C, and
under a pKessnre of 1 metre of mercury. If v represent the volume of gas as taken
from the table, m ike error of the meniscus, b the heidbt of the mercury in the gas-
tobe above that in the trou^ f* tibe temperatore, and B the height of the barometer,
the foDowing formula wiU give the corrected volume V\ under the standard tempe-

ratnreandpessure: v_____. . p-.

There is also another point whidi must not be overlooked in the calculation, viz. the
cffict of the tension of water-vapour. If the gas is saturated with moisture, and the
tempentnre at which the observation of its volume was made is known, it is then
only neeeasary to refer to the table of tensions of aqueous vapour and extract the
number oocreaponding to that temperature : this must be deducted from the height of
the banmeter. Thus, the formula for the reduction of gases saturated with aqueous

TBPoor is V '*' **)^-" "" 7 ^ -i V\ where T is the tension of aqueous vapour

^^^ 1 + 0-00366^ . .

Ibr the temperatoze ^. To ensure a gas* being completely saturated with moistore, a
drop of water is always introduced into the eudiometer before filling it with mercury.
Ill order to show more clearly how tiiese calculations are made, the following ex-
ample taken from Bunsen's Gasometry, is dted, of the measurement of the same
quasti^ of air, first saturated with moisture and afterwards dry.

Obaeration at the lower level of the mercury .
Obaeryation at tiie upper level in the eudiometer
Height ci the column d to be subtracted from

barometer •••••••

Hm divisioiis 317*8 and 310*7 correspond to the

Tcrfumes in the table of capacity
Ooirectioii fiir the meniscus
Temperature of the air
He^t of the barometer •
Tension of aqueooa vigour for 20-2 G

Vol. I.

Molit. Drj.

666*9 mm. 666*9 mnu
317*3 310*7

248*6

266*2

r • 292*7

2860

m 0*4

0-4

t 20-2 C.

20-2 0.

B 07469 m.

0*7474 m.

r 0*0176 m.

274 ANALYSIS (VOLUMETRIC) OF GASES.

)oe.(F ■(- M) - log. 203-1 - 3-46701

+ ]«g.(B - b-T) -]^ -4807 - 0-8818; - I

-«- etn^ log- (1 ->- 0-003860 - ''^mpL W 1-0739 - O-96903 - 1
tog, r- a-llTBi ■

V 131-M.

For tlie di7 air ve luve ;

log. ( F -I- m) - log. 286-4 - 2-4EeST

+ log. (5 - A) - log. 0-4S22 - 0-88314 - I

+ compl. log. (1 + O'OOSSSf) — coiifl log. 1-0739 — 0-96903 - 1
tog. r 211814

V - 131-38.

A modlflcatioD of Btmsen's method has lieen proposed bj ITusn. Williimion
andBaaiell(Pn>c«ediags of thsBoja] Sodetj-, toL ii. p. 318), w^anlnlheefinl
of U1T Rltantioii in the buometer at thenoomelar on ttae gu daring the uiijsi
IB eotirelj duniiiBt«d : moreorei, the gas operated on is always raad off tatwited
with aqneans lapoar, lo (hat no cslimlaiions are neceasar; for redodii^ tht
volume to a gtandud t«mperatDre and presaore. The principle on which thii impli-
flcation depends is, that of alwajg retaining the gas at thf same degree of etu-
tioity. Jt, for instaoee, a fall of tempejatnre has OH^nrred, then br i^irniri«liiT}(. thi
pruBBUre on the gas a certain amount, its elaaticitj will remuD unaltered ; uid fn i
nsfl in temperatnr^ thepreesore most l>e coiroapandingly increased to rstain tht pj
at the Bama yolnme. TMb aqnallj appliea Ia any alteration in the barometer. Ttt
means adopted for aaeertaining exactly how mach the pressure on the gu hu In be
increased or diminished for any Tariations of the barometer or thermometer, ii aa^
to inbodace a standard qoactity of sir into a tube oier mercan, and mark off Iht
height of tiie mercury on the tube, at the normal lemperatnre and presfure ; then, il
any othal temperature or pressojre, bj raiaing or lowering the tube in the durht-
(raugh, BO BB exactly to bring the mercni^ again to the same mark, the elsilirit] ^
the air is maintained constant. The gas in the eadiomater is always read off at Ihit
constant d^ree of expansion, and this is done merely by raiaing or lowering it in 11k
trough, untd the column of mercury within the eudiometer ia of exactly the mat

height w that in the tube conUining the itandoid amoont of air. Pig. 68 itpnsniti

i» — r^

the appBTalos used in this method, a b is the tube containing the standard awiuil
of air, and ia termed the '^pressure-tube:" the upper part of it ia aii or serm
inches toog, and of alwnt the diameter of an ordinary Bunsen's endiometer; the lover
part B is of about the same length, but only | inch internal diameter. Into tttis pv-
■nre-tnbe is introdnoed such a qtuuititj of mercoiy that, when it is inrerted in the
trough, the marcarr stands at a convenient height in the oarow tube ; at tbie poiol, llw
nark is made which indicates the height of mercurj needed at any tcmpcmlare or per

ANALYSIS (VOLUMETRIC) OF GASES. 275

nue, to reduce the endued air to ita origiiuil Tolame. The mercurj-trougb c n differs
Sroa the ordinaiy form in beiiig provided wiUi a well B, ■( one end, in which the
cadiometer is to be rwaed or lowered m ■> to bring the gu it contHins to the rama
pmsure u the air in the preesore-tabe. Both the eudiometer and the preuore-tnbe
m held in aperpendicolar position bf meau of ditmpa r and a, irhich slide on up-
right loda. £ach damp ii prorided with a simple kind of slow morement, by which
the tabs can be rsised or loweied bf the operator, whilst he is looking through a
telescope at a snitable distance.

Fig. S9 ii an enlarged view of one of the clampl, which sbowa more diatjnctlj how
the uow movement is produced, a. is the part which slides op and down the veitieul
rud; it is fbniish^ on the iiuide

with a small steel peg which mores Fig. 69.

in > groove, thus csnaii^ the arm
aJwsTS to remain in the same plane.
c D n a tobe through which the rod
r, aiTjiDg the clamp, passes, n is a
■crew which retaina the rod r in its
plae^ and bj mean* of which the
friction on the rod passing throogh
the tnbe can be increased at pleasure.
0 is a small cylinder flied to o d ;
on taming this round to the right or
to the left, the string above or below
is wonnd on to it, and consequentlj
therod rnuKd or lowered. !□ order
that the heat from the body maj not
affert the volume of the gases in the
tabee, thin iron rods, aome six feet in
lei^h, are screwed into these cylin-
den, and rest on the arm carrying
the telescope, as shown in Jig. £8. h
is merelj an arrangement for tighten-
ing the atiing. K is a peg so placed I
with r^ard to the stop i., that when, 1
bj turning the damp round, it is
pressed agaioBt the stop, the tube is
then in the right position for uppljing

the final adjuibDent and readmg off. In operKting with this apparatus, the pressure-
tube is placed immedialel; in front of the endioiceter, and tae clamp moved up or
down the vertted rod till the top of the mercmy inside about coincidea with the mark
on the stem of the tube ; in the same way, the eudiometer is so at^justed that the
internal column of mercury is of about the same height as that in the preasure-tube.
The iron rods are than screwed on, nnd the whole allowed to cooL

The method adopted in reading off the amount of gas is, while looking through tho
tdescope, first to tnrn the rod connected with the pressnre-tube so as to bring tho
mereuiy exactly up to the muk on the stem, then raise or lower the eudiometor no
that the meniscns of the mercury inside it may coincide precisely with the meniecus in
Ibe preasnre-tube. This is easily dona, as the diameter of the preBanre-tubo ie con-
mderably nnaller than (hat of the eudiometer, and the meniseoB in the latter can be
deariy seen on both sides of the meniacnB of the pressure-tube. Jt is convenient dso
to have a second pressura-tube, the stem of which shodd be about three times as long
■II that of the one already deseribed. By this means, when only a small amonnt of
gas has to be measured, it can he read off ut a greatly reduced preannre, and eonse-
quentlj with greater absoloto accuracy. la order to render the reading made with
one piiseure-tobe comparable with those made with the second, it is only necessary to
measure the same amount of gas at each of these degrees of expansion, this at onco
twtabliahea the proportion in which any amount of pi read oC^ at the greater d^jree
of expanaioa, for instance, will have to be diminished in order to reader it com-
paikble with gas read off at the lower degree of expansion, lliis method yields veir
sccnrate results, and they are obtained with leas trouble than by Bnnis^p'B method,
Kiid without any tedious calcdotions.

The metliod and apparatus nfit to be described (s that proposed by MU. Begn a nit
u>d Beiaet (Ann. Chim. Phys. [Sj nvL 333). Its pecoUar wlvantage is, that
analyWH may be made hj^ it wiOi very much ereater rapidity than ia possible by
either of the methods previously described, and also (hat it doee not require a room to
Iw set tjmit for gas analysis.

276 ANALYSIS (VOLUMETRIC) OF GASES.

The eeoDomT of time is effected in two way* : first, bj snTromiduig Ibe gu-tibM
«ith miter, TUich almiwt immodiatel; caiuea their coDteDte to isanme tlu mm
tempusture aa th&t of tlie eitemol medium ; secondJf , hj the use at liquid Mgniii
iuatead of solid, which ore necessarily used in BmueQ^s method.

The fbnn sod principle of H. BegQsalt'B spp&ntue will be ettilj nndentood tna
Jiffi. 60 and 61. It consista esBentioU; of two partA, whidi can be ssailj juoed ud

Fig. 60. Fig. 61.

aepanted. In the one part, the gas is snljecttd to the action of liie liquid ieegaitii*>d
this is termed the laboratory or abaorption-tabe; in the other, the gu iimei-
anred, and it is £enned the meairaring-tabe ; these ore represented in the Bgartt 1^ /}<
and a b. The meaaoring tube ab, in from IB to 20 mm, internal diameter. It i> diTidgd
into millimetres, and tonninatcs above in a fine capillary tnbe a r, wMls lie lom'
ead is luted into a cast iron piece Nlf, baying two tubulations, b and c, and a itqin^
S. To the second tabulation i^ is luted a atraight tube e d, open at both enda, al"

Fig: 62, 63, 61.

same diametar as the tube a b, and divided also into millimefres. The stopcoA B j"
bored through in two directions at right angles to one another, as due* 1"
fiffi. 82, 83, and 64, oo tiat by turning the key in diflbreut pomtions, fomn""'-
cation can be established between the two tubes a bmied, or the meicniy can n

ANALYSIS (VOLUMETRIC) OF GASES.

277

Fig,

66.

• ^

Fig. 66.

•Qoved to flow from either. These tubes are surroiinded by a glass cjlinder filled
vith water, in which the thermometer T is immersed. Bunng the analysis, the
tbeimomet^ mnst of course indicate a constant temperatore ; should any altenition
have taken place, the original temperature mnst be restored by the addition of hot or
cold water.

The whole apparatus is fixed on a cast-iron stand z s, fiunished with levelling-
serewsw The^ absorption tube o /,iB open at the bottom and terminated above by a
ciDTed^pillaiy tdbe/e r\ This tube dips into a small mercuiy
txDogh )% of cast iron, or what is still better, gutta-percha,
Figs, 66 and 66 represent more clearly the form of this trough.
IVnen in its plaoe^ it rests on a small iron bracket, which by means
of the rack t i» and the pinion o, to which the handle b is at-
tached, is easily mored up and down. It is retained in any
position by the rachet q, to which, in order to facilitate its
VQzking, a weight is fixed, and as this is turned from one side
to the other, the rachet is thrown in or out of gear with the
pinion. To the ends of the capillary tubes, which terminate the
abeoq^tion- and measuring- tube, are carefully luted two small
fteel stapcocks, r /, the ends of which exactly fit each other,
and hare the shape represented in Jig. 67, in section. In order
to render the joining of the two as air-tight as possible, a little
melted caoutchouc is applied to the faces a b and a' b\ which
are tiien pressed together as tight as possible by means of a screw
damp, represented in Jig. 68. The laboratoiy-tube is held in a
Totical position by the clamp «, which is lined with cork, and
can be adjusted to the required distance from £ z, by means of
the screw s. The measuring-tube a 6 is proyided with two
platiniim wires, as in the ordinary eudiometer. The following
aoooont giTen by Begnault (Cours de Chimie, iv. 77) of an
aoalyBis of a mixture of air and carbonic acid will perhaps best
exdain how the apparatus is used.

The first operation is to fill the measuring-tube : this is done
by pouring mercury into the tube e d^ until it begins to escape
tfaroofl^ ti^e stopcock r, which is then dosed. The laboratoiy-
tube 18 next filled by plunging it into the mercury-trou£^h F*, the
stopoodL r' being open, 'xo fill the capillaiy-tube /« r , the best
method is simply to apply the mouth to the open end of it and
sock the mereniT up, then dose the stopcock. The tube being
now periectly fou of mercuiy, it is fixed in its place and the
damp screwed on to the stopcocks.

Tl^ gas to be analysed is now introduced into the laboratory-
fohe^ the trough V baying been lowered to such a position that
the end of the laboratory-tube only reaches to a short distance
under the mercuiy ; the gas is then easily passed up into it This being done, the
tTDOgh is again rtused and the mercury allowed to flow out of the measuring-tube, by
which means the gas is forced oyer into the measurins-tube. When the mercuiy reaches
the cainllaiT tube / e, the stopcodc r is nearly dosed, thus causing it to rise but slowly,
and wnen the column of mercury airiyes at a certain mark <r on the horizontal part of
the capillaiy tube, the stopcock r\ is dosed. The leyel of the mercuiy is thus
brought to a giyen diyision a, of the tube a 6, and the difference of height of the two
cohimns can immediatdy be read ofiP on the scale of the tube c d. The water should
be well agitated by blowing air into it through a tube which descends to the bottom of
the cylinder. The height of the thermometer and barometer must also be obseired.

In order tiiat no calculation should be necessary for estimating the tension of
aquDons yapour, the gas is always saturated with moisture ; this is done by moistening
the aides of the measuring-tube ah: the mercury, in passing through, merely remoyes
the excess of water, and always leayes a small quantity a&ering to the sides of the
tube; Let t be the temperature of the water, which, as before stated, must be station-
ary during the analysis, f the tension of the aqueous yapour at this temperature ; v
the Tolmne of the gas ; H the lieight of the barometer ; and lastly, h the difference
of the height of the mercuiy in the two tubes. H + h + f Ib then the elasti-
city of the gas when dry. Haying thus measured the quantity of gas taken, the next
operation is to absorb the carbonic acid present. The trough Via again lowered and
by means of a bent pipette, a single drop of a strong solution of caustic potash is
introduced into the laboratory-tube.^ Mercuiy is then poured into .the tube e d, and
the stopcock b turned so as to establish communication between the tubes a b and c d.
On opening the stopcocks r /, the gas is then forced back into the laboratory-tul^e,

T 3

1^.67.
Ftg. 68.

278 ANALYSIS (VOLUMETRIC) OF GASES.

As the mercury in it sinks, the caustic potash moistens the sides of the tube, ihos
exposing a yery large absorbing soi^ioe. In a few minntes, the vhole of the eaibonic
acid is absorb^ ; and the absorption may be rendered still more speedy and certain, by
raising the trough and opening the stopcock r, so that the pas may again be drawn into
the measuring tube and afterwards forced bade a second tmie into the labontory-tabe^
thus bringing it in eontact with a fresh siir&oe of potash. Ithas been ^ownthiit after
this operation has been repeated twioe^ no appreciable amount of carboni^add lemaina
unabsorbed. As it is essential that none of the absorbing liquid should eter paat
over into the measuring-tube, the error arising from an amount of gas remaining in
the capillary tube / « r', is best eliminated by always making this a constant quantity,
which IS done by dosing the stopcock t\ when the column of liquid reagent or mereoiy
arrires at a certain mark v.

The absorption being completed, the lord of the mercury in the tube a ft is again
brought to the mark a, and the difference of height K of the mercury in the two tubes
a h and c (2, is read ofC B* the height of the barometer, is also noted. If the tempe-
rature of the water in the cylinder has changed, it must be restored to the original
temperature ^, by the addition of hot or cold water. The elastic force then of the gas
deprived of carbonic acid and dry, is ^ + K —f; and oonsequentlj (J? + * - /) -
(If + h' — f) ^ H -^ H' + h —^ h\ ia the diminution of elastic force, caused by the

jtr _ fj' 4. I X*

absorption of the carbonic add ; and -rs -r 7 represents the proportion ef

carbonic add in the gas when dry. — The proportion of oxygen in the remaining gas
has now to be determined. The laboratory-tube is detadied, thoroughly washed, and
dried, first by means of paper, and afterwards by bringing it into connection with an
air-pump. It is then agam filled with mercury and fitted on to the measoring-tabe.
The trough u is now raised, and the stopcodc r opened. On now turning the codks r r\
the mercury in the laboratory-tube passes into the capillary-tube a r, and is allowed to
proceed as far as a given mark r ; when it reaches this mark, the stopcocks r r ' are closed.
The mercury in the measuring-tube is then again brought to the point a, and the
difference of the level h" and the height of the barometer &" read off IT* + h' '-f
is therefore the elastic force of the dry gas now in the apparatus, a smaD qnanli^
(about s^) of the whole having been lost by detaching the laboratoiy-to.be. This
second measurement prevents any inaccuracy thence arising.

A proper quantity of hydrogen is now introduced, and a uniform mixture of the
whole product by passing the gas two or three times backwards and forwards from
the laboratory-tube into the measuring tube. When thoroughly mixed, the oolnmn of
mercury is again brought to the mark r, and the sas in ute measuring tube to the
point a. The difference of height hT of the two columns of mercuzy is read ofl^ and
the height H^' of the barometer. H^ + h'" ^ f U therefor© the elastic force of th*
mixture of hydrogen, oxygen, and nitrogen. The capillary- tube ra^ is now com-
pletdy filled with mercuiy, so that none of the gas shall escape combustion, and an
dectnc spark passed through the mixture. After the explosion, the stopcocks r r are
carefully opened and the ^ subjected to a slight pressure, so that the mercniy is
forced bacK along the capillary-tube tUl it arrives at the point r ; the stopcocks are
then again dosed, and the gas expanded as before to the mark a. Its elasticity
now be represented by ST" + h"^ - /. Consequently {JT* + IT ^ f) - (H" +
hr - f^ ^ H^ - k*^ + A"* - IT, is the elastic force of the wsecras mixtare
which disappeared during the combustion ; \ {H^ — H*^ + A"* — A ) is the clastic
force of the oxygen contained in the diy gas, of which the elastic force was H' + k'-f:

XT'** if"** J. A** _ A***

and J ^ k"* — ^ ^ *^® proportion of oxygen contained in the gas when

fireed from carbonic add, whence the proportion of oxygen in the original gas may be
easily deduced.

As the gajB is made to occupy a constant volume during the whole analysis, this
entirely removes the necessity of calibrating anv of the tubes. This apparatus may,
however, be used in a different way, and then the calibrating of the tube a h becomes
necessary. In this case, instead of always bringing the gas to a constant volume and
reading off the pressure it supports, the pseesure is retained constant, and the diffiearence
of volume read off. The cauDration of the tube a b is' effected by filling it oonqtletely
with mercury, and then allowing a small quantity to fiow out through the stoooock i.
eollecting and weighing this, then reading off on the tube the height througn which
the mercury has fallen. The temperature of the water in the cylinder should be kept
constant during the whole operation.

The apparatus of MM. K^nault and Beiset leaves but little to be desired vith

regard to the rapidity with which analyses can be made ; but this rapidity is to a

certain extent obtained at a sacrifice of accuracy, considerable change in the bulk of

'{as operated on being represented by onlv a small change in the amount of pressure.

n a comparison made by Messrs. FranUand and Ward, of the methods of Bnnsen

ANALYSIS (TOLUMETRIC) OF GASES. 279

iDd Begnanlt, it vw iliowii that an eiror of ^ of s miUimetTS in tlie flret ol*«r'
Tttion vonld causa in B^nault'a method an enor in the pereentige amount, aeren
tints as KK*t aa woold be tlie caae when Bonaen's method ira« adopted. There is
also «aiti£nlile practie*! difficult in maintaiiiiiig the water in the t^lmdsr at pceeiBelj
' « Ito any length of time togMhn.

I of SHiantaa foF the
nethod of working

time BSOT inmortant adTan-
t^eaorerit. Ibedbctofat-
rao^b(*ie ^l^»wu^e on the (pis
is entiidj ramored ; the pnn-
dple mdc^ited in messnriug the
amooBt of gas yidds very sc-
aoata nsolta ; the gu may be

raidBring this ^ipaiataa Mia of

conaidcrable importunes. Fig.

69 is k drawing of the appan-

tna. "Itconsistaofthe.tnpbd A,

famished with the osnal lerel-

ling aerewa, and carrTing tha

Tstdeal pillu B B, to viucb in

attached on the one aide iiie

moTBble mncnij-tHmgh c, of

gnttA-pereha, with ita rsd and

pillion a a, and on the other

the g^aaa cylinder d d, with its

contents. The cylinder is 36
indiee lon^ and i inches in-
ternal diamrter; ita lower ex-
tremity ia flimly cemented into
an iron collar c, the under
BOrtaCG of wtich can be screwed
perfectly watertight upon the
brBCket<(il«(e d, by the inter-
position of a Tnlcamsed caoat.
ehooc ring. The circnlar iron
plate d a perfbnled with tJuee
■pertare^ into which the cape
( e « an screwed, aod which
eommanicata below the pUte
with the T-pioce ■ b. This

latter is formahed with a doable-waycock /, and a aindo-wsycock g, by means of
which the tabes cemeoted into the xwkets se«,eanbe made to communicate with each
other, or with the exit pipe k at pleamre." r, a and u are thtee glass tnbes which
are fiimlj cemented into the eqie tee. r and h are each IS to> 20 mm, internal
diameter, and to amid any difference in the capillary action, are eelected of a« nearly
the aalBe bore aa possible. The tube □ ia somewhat wider, and may be continued to
tmj eoDTenient height abore the t^linder. h ib secimtely gndnated into milli-
mebes, and is Aimished at the top with a BmnJi funnel t, into the neck of which a
^*m stot^er, about 2 mm. in diametw, ia earefollv EToand. The tnbe r terminates
at ita opper eitreniity in the capillary-tabe *, whidi is earefnUy cemented into the
small ateel stopcock /. F has also fused into it at m two platinum wires, for the paassgo
of the electric spait Ailer this tube has been firmly cemented into the cap (, its in-
tenal Tolnme is accurately divided into ten equal parts. This ia done first by filling
it with mepcniy from the supply tube o, np to its junction with the capillary tube t, and
thenallowinglhe mercnry to run off through the noide *, until the highest point of the
meniscus stands at the dirision 10 preTiously made, >o as exactly to coincide with the
' — - - , n off is care-

re tenths of the entire weight, and
IS after each abstraction of the metal.

28a ANALYSIS (VOLUMETRIC) OF GASES.

by Bcrewing a small copper ring on to the tnbe at that point. By nsng proper pn-
cantiona -with regard to temperatoro, &c., an ezceedingly accurate ealibtatioD on be
made in thia way. In practice, however, it is found nmch easier to make the cdibn-
tion in the following manner. The ten copper rings are screwed on to the tabo ibit,
at abont eqnal distances apart, bnt withont any relation to the capacity of the tube,
which IS afterwards ascertained by expanding the same volume of gas down to eidi
of the ten divisions, and reading off the height of the column of mercury in the tabe
H in each instance. The way in which the uboratory tube j is joined to the rest of
the apparatus is precisely similar to that adopted by HM. Begnault end Baiset, and
alreaoty described.

When the instrument is thus &r completed, it is requisite to ascertain the hci^
of each of the nine upper divisions on the tube above the lowest or tenth dirinon;
this is very accurately dTected in a few minutes by carefuUv levelling the iostamient,
filling the tube o with mercury, opening the cock 2, and the stoppered Amnel i^ and
placing the cock / in such a position as to cause the tubes F E to oommimicate vitfa
the supply-tube a. On now sughtlv turning the cock a, the mercury will bIowIt riie
in each of the tubes F and h ; when its convex surnoe exactly ocHnddes vith the
ninth division on f, the influx of metal is stopped, and its height in h aoeontelj
observed ; as the t^th division on f corresponds with the sero dT the scale iqion e,
it is obvious that the number thus read off is the height of the ninth division above
the zero point A similar observation for each of the other divisions upon f oompletei
the instrument.

Before using the apparatus, the large (^linder d d is fiUed with water, tod the
inside of the tubes f and h are once for all moistened with distilled water, hj the
introduction of a few drops into each, as in Begnault's apparatus. The three tabes
being then {daced in communication with each other, mercury is poured into o until
it rises into the cup t, the stopper of which is then flnnly dosed. When the mercoy
begins to flow from /, that cock, is also dosed. The tubes f and h are nowapparenUj
filled with mercury, but a minute and imperceptible fllm of air still exists Wirea
the metal and the glass : this is effectually got rid of bv connecting f and h irith
the exit-tube A, and allowing the mercury to flow out until a vacuum of several inchei
in length has been produced in both tubes. By aUowing the instrument to remain tfau
for an hour, the whole of the film of air above mentioned will diflbse itself into the
vacuum, and will become visible as a minute bubble in each tube, on allowing the
vacuum to be filled up from the supply-tube a. By opening for a moment the stopper t
and the cock /, whilst o is full of mercury, these bubbles are expelled. The absorption
or laboratory-tube z being then filled with quicksilver, and att^uihed to / by the aoev
damp, the instrument is ready for use.

The method of introducing the gas, applying the absorbents, and pssdng the gu
from one tube to the other, is in thos apparatus so precisely similar to that adopted in
using Begnault's apparatus, and before described, that it need not be further dwdt
upon. The method of reading off the amount of gas is, however, different, and
requires a few words of explanation. When the gas has been passed orer into
the tube f, taiercury is allowed to flow out of the stopcock /) untU a vacuum of tvo
or three inches in length is formed in h, and the metal m f is just below one of
the divisions ; the cock / is then reversed, and the mercurr very gradually admitted
from o until the hip^hest point in f exactly corresponds with one of the divisions on
that tube ; that this is really the case, must afterwards be ascertained by viewing it
through a telescope. The height of the mercury in the tube h is then read oi£ If
the division on the tube F, to which the gas has been expanded is, for instance, the
fourth, then, from the number read off on the tube h must be deducted tiie height of
this fourth division above the zero point of the tube. The remainder will express the
volume of the gas; but in order to compare this with subsequent readings made at
other divisions upon f, the number thus obtained, which represents the pressure of the
sas, is fDduced to what it would have been had the gas been expanded to the tenth
division of f. This is very simply done, by merelv multiplying the number npif'
senting the pressure of the gas by a fraction whose denominator is 10, and numerator
the number of the division to which the gas has been expanded ; thus, in the case above
cited, the multiplier would be 0*4.

The following are the results of an analysis of air made by Messrs. FranUand and
Ward.

Volume of air used. (Determined at fifth division on f.)

Observed height of mercury in h .... 673*0 mm.

Height of fiftn division above zero .... 888*0

Corrected pressure of gas 290*0

Corrected pressure of gas at tenth division . . 145*0

ANALYSIS (VOLUMETRIC) OF GASES.

Volwne after the udmiiwrion of hydrogen. (Determined at sixth dmsion.)

281

Obeerred height of mefcur in h
Height of sbSh diTieion above seio

Ccmected pname of gae

772*8 mm.
304*0

OoBreeted pfueeum of gas at tenth dirision

Yofauiie after ei^oeion. (Detennined at fifth division.)

Obeerred height of mercniy in H
Height of fiftn division above zero

Correct prcKnire of gas • • • •

468*8

-e

280*98

. 763*8
. 888*0

. 380*3
'6_

GoDeeted pressue of gas at tenth divisioa • . 190*16

Volome Off air used 146*00

Yclnme of oigrgen 30*276

•

Nitrogen 79*120

Oxfgen 20*880

100*000

Greatlj si^wrior as this ibnn of appeiatos is to that of Regnanlt, and capable as
it is of jieUhng aoeorate and rapid resolts, still there are defects in it which detract
somewhat ftom its practical vahiCL The principal of these is Che great difficnlty there
cxista in always maintaining the apparatus in a perfectly air-tight condition, especially
ss the stopcocks Tend I have to be joined and separated once or mce during an analysis.
ConsideiaUe inoonTenience has also been foond to arise from the yerj fragile natore
of the laboratoiy-tabe ; this, even when frill of mercnry, is only supported by the
fapJUaty tube, to which it is fiised, and consequently the slightest blow or pressure
upon it is upt to cause it to separate at this point of junction. Some difficulty is also
e^wrienced in keeping the water in the cylinder at exactly the same temperature
dming the whole course of the analysis. Begnault, as before stated, suggests adding
hot or cold water till the required temperature is obtained; this ia aa operation
'iHiidi takes considerable tinier and without much care is likely to lead to fallacious
resnha. Br. Frankland has poposed using a stream of water direct from tiie street
main, which enters the cylinaer at Ae bottom, and is allowed to flow off by an ezit-
tabe near the top. This is a great improvement upon Begnault^s method, but even
with this snangement, slight variations occasionally occur.

Having now described the principal forms of apparatus used in the analysis of gases,
we shall proceed to state the methods to be adopted for the separation and quantita-
tive estimation of the different contituents whidi may occur m a gaseous mixture.
Oases which have a strong affinity for any particular reagent, are estimated directly by
introducing the reagent into the absorption-tube ; but since many gases are not absorb-
able in this manner, another and indirect method has to be adopted, as foot instance,
in the case of hydroeen, which is estimated by eroding it with oxygen and observing
the diminution of vmume thence ensuing.

The following list will show which gases sre estimated directly and which indirectly.
Two of the number, namely oxygen and carbonic oxide, will be found in both lists, as
they can be estimated by either method.

Gates uiiimaUd by ike direct method.

Hydroehlorie acid (anhydrous).
Hydrobromic acid.
Hydriodic acid.
Bydrofluorie acid.
Hydrosulphuric acid.
Mphurous add (anhydrous).

CSarbonic add (anhydrous).
Oxygen.
Carmmic oxide.
Olefiant ^s.
l^itric oxide.

l^itrogen.

Oxygen.

Bvdroften.

Gatei eatimaUd mdireetlgf, •

Light carburetted hydrogen.

282 ANALYSIS (VOLUMETRIC) OF GASES.

The gaaec estfanated by abtenpCion maj, fur analytical pupons, be ooDTnuentlj
divided into tiivee grovqia.

Ist Gimro:— .^filrodUom mad; Bydrthrvmic mdd; BydHoUe aeid. Them an
absorbable Dj meana of anlphate of sodium.

2nd Gioiq» : — ^fdromdpkmne add; Stdpkmnnu add; Carbonie add. These an
absozbed by cftuatie potash, but not by sulphate of aodinm.

SrdGroap: — Oxygen; NUHe oxide; Canome oxide; (X^fiant ^a». These an
neither absovbed by soliJiate of aodiom nor by eanatie potash. With legaid to the
manner of appljing the reagent* if the appantns of Bcipianit or Fianklsnd be used
a few- drops of a Teiy strong solution of the reagent are intzodneedinto the labontoij'
tabe, by means of a bent pi^tte, as little of the liquid being used as possible, to pre-
rent any appreciable loss siuing from its absorbing power. But in using Bmue&'B
method, or that pt^nsed bj WiQianison and Buasell, the reagoit must be intzodaeed
in a solid farm, if possible^ or if neoessazil j a K^d, some porous snbstanoe mut be
saturated with iti.

Estimation of the Gases of the 1st Group. — ^IDie sulphate of sodium is intn-
duoedinto the gas bj first melting it in its water of crystallisation, and then dipputf
into it the end of a platinum wire ^Hliidi has been bent into a shortcoil; this is rqM»tea
several times untQ a ball of the sulphate of sufficient siae is obtained. If mudi of
these adds is believed to be present, the ball ahould be of a laige sixei or else the
sulphate of sodium is i^t to become deUquesoent^ and run down the sides of the tube.
All aqueous vapour must also be carefully removed from the gas before uitrodudng the
sulphate of sodium. This is best accomplished bj means of a ball of phosphorie add,
iriiich may easily be made bj dipping the coiled endof a platinum wire into hot liquid
phosphoric acid ; a drop adheres to the wire^ and then as the add eoola the siie of the
ball IS increased to about thatof a large pea, by turning it round in the viscous nieUed
mass. The thickness of the platinum wires nsied in tl^se eneriments ahoold be aadi
that the balls of reagent may be easOy poshed into the enaiometer without the vin
bending. Qreat care must also be tiJ^en that the surface of the ball is as smooth ai
possible, or adhering air will be intzoduced into the gas, and some of the gss remond
on withdrawing the balL Oxide of bismuth qpr sine may also be used for abenfaiag
the members of this group. A ball of these substances is best made by applyingthe
moist oxide to the end of the platinum wire^ and then igniting it in the iluie of a
spirit-lamp. The results obtained with these absorbents are^ however, geooaUy not
quite so accurate as those obtained with the sulphate of sodium. Thedifferent memben
of this group cannot be separated by any eudinmetrical process. If several of then
oocur together, the ball of sulphate of sodium used for their absorption must afte^
wards be dissolved in water, and the solution an^sed in the ordinary way.

Estimation of the Gases of the 2nd Group. — ^As stated above, the memben of
this group are all absorbed bj caustic potash. A ball of this substance is made 17
fusing caustic potash and adding suffident water to render it^ when cold, soft enoo^ to
receive an impression from the mul ; the end of the platinum wire bent into a oofl is
then placed in a bullet-mould of convenient size, and the frised potash poured in. If
the baQ should adhere firmly to the mould when cold, as is sometimes the eaae, heat
must be applied ; it will then easily be removed. On using a potash-ball £>r ibsoibing
gases, it must always be moistened with water before introdudng it into the ps.
When much gas has to be absorbed by this means, the potash-baU should, after some
hours, be removed fit>m the eudiometer, washed, and then again introduced. It should
be allowed to remain some four to sis hours in contact with the gas^ in order to enmre
complete absorption.

Hydrosulphurie add, — ^This gas is best absorbed by means of a ball of peroxide of
manganese. The manganese is very finely powdered and made into a tbi« paste, vith
water ; this is introduced into a bullet-momd with the platinum wire in it, an^ then
dried on a hot sand-bath. I^ however, this bedl were at once introduced into a
gaseous mixture, it would, from its porous nature, absorb an appreciable amount of
other gases besides hydrosulphurie add. To obviate this, the ball before being used
should be thoroughly moistened with a syrupy solution of phosphoric add ; care m«t
however be taken that this does not soften the bidl, or it may fiiU to pieces on attempt'
ing to introduce it into the eudiometer. There is also another method of estimatiog
th^ ^, but it is applicable only when sulphurous add is not present A potash-ball
containing a large quantity of water, but not moistened externally, so that, on vith-
drawing it^ none of the potash remains in contact with the mercury, is introdnoed into
the eudiometer : this absorbs the hydrosulphurie and carbonic acid, if any is present
" Distilled water addulated with acetic acid, is then boiled in two fiasks until all the
dissolved air has been removed ; the contents of one flask is then poured, whilst boiliiA
into the other, filling it up to the top of the neck. The fiask is then well closed wiu

ANALYSIS (VOLUMETRIC) OF GASES.- 283

t eoffk eorered with a plato of caootchone, so tiiat no babble of air ib left between the
liquid and the eaontchonc plate. As the liquid cools, the cork is pushed farther into
the neck, in order to prevent the formation of a vacnons space and the possible en*
trance of air. The bau of potash, cut off from its platinnm wire immediately on with-
drawal from the gas, is allowed to dissolye in this liquid when cool, and a few drops
of a dear solution of starch are added." * The amount of hydrosalphnrio add present
is then determined bj means of a standard solution of iodine, in order to free the
determination from any enor which might arise from imparities in the potash, the
OLperimokt is repeated exactly in the same way with a ball ot the same potaah, bat
eontainin^ no solphide of potassiom. The amoont of iodine used in this case is then
sobtracted from tne amount osed in the former experiment*

Sulpkmwu add. — ^This gas is estimated by exactly the same methods as those
adapted for hydrosnlphaiic add.

Carbome ecML—Canatie potash is the reaoent alwa^rs osed in detennining the
amoont of this gas in any miztore. The method of preparing the baU, and the neoes-
saiy precantionB in asiDg it^ were described when speaking df potash as the general
abeon>ent of this groap.

Estimaiion of ike Gases oftheZrd Group. — ThisgroapconsiBtsoffoar gases
not absorbable diher by salphate of sodiam or by caastie potash* They will be treated
in the order in which &ey woald haye to be separated from a flaseoas miztare.

Oxygen. — ^Ibis gas may be estimated dther directly or indirectly, Ihe method to
be adopted in any particalar case depending on the qaantity present, and the nature
of the gases with which it is mixed. If other combastible gases arepresent^ or if there
is onhjr a small amonnt of oxygen in the mixture, it is always better to estimate
it directly. The method to be adopted in determining it indirectly will be described
farther on. Phosphorus was formerly the substance generally used to free a gaseous
mixture from oxygen ; but owing to the tension of the vapour of the phosphorus add
formed, the difficSt^ of removiog i1^ and the action which many gases have in pre-
Tenting the union of phosphorus and oxyee» at ordinary temperatures, the use of
this reagent is apt to lead to incorrect results. A much better method of absorbing
oxygen is to use pyrogallate of potasdum. It may be introduced into the al^
Boiption-tobe dther by means of a papier-machd ball, or if liquid reagents are used, a
few drops of a strong solution of the add are first introduced and some caustic potash
added to it

The papier-machi ball is made by thoroughljr macerating some bibulous p^)er in
water, uien, having introduced the platinum wire into a ballet mould, and tied the
two bandies together so that it cannot open, as mudi of the pulp is forced in round the
platinum wire as poedble. After being dried on a sand-bath, a hard compact ball is
thus formed ; this is thoroughly saturated with the pyrogallate of potasdum, and then
immediatdy introduced into the gas. The absorption of oxygen by this means is not
always yerj rapid, and it is often necessary to withdraw the bail from, the eudio-
meters agam saturate it with the pyrogallate solution, and introduce it a second time
into Ae eudiometer.

nitric oxide. — ^This gaB and oxygen can, of oaurse, never occur together. The best
method of estimating it, is first to convert it into nitrous add and then absorb the add
thus formed, by po t a s h. For this purpose, a few babbles of oxygen are introduced into
the gas in the absorption-tube, and afterwards potash, dther in the solid or liquid
form. When the abaoxption is complete, a forther quantity of oxygen is added ; if
after this addition, no absorption is caused by the potaish, then an excess of oxyeen is
present, but if abeorption again takes place, more oxygen must be added. Having in
this manner ascertaued that the whole of the nitric oxide is removed, it then only
remains to absorb the excess of oxygen present, by means of pyrogallate of potasdum,
as before described. When this ^ is mixed with nitrous oxide, olefiant gas, or hy-
dride of ethyl, this method, according to Br. Frankland, gives good results ; but in the
presence of o^er hydrocarbons, it is poedble that the nitrons add and peroxide of
nitrogen might exerdse an oxidising action on them, and thus vitiate uie results.
ProtMulphate of iron was also formerly used as an absorbent for nitric oxide ; but it
does not yield very satisfSMtoiy results.

Carbome oxide, — ^Like os^gen, this gas is also estimated sometimes directly, some-
tunes indirectly. At present, its direct estimation only will be treated of, This is best
effected by means of a concentrated solution of subchloride of copper. A papier-
madi^ ball, similar to the one used for the pyrogallate of potasdum, is the best means
of introdoeii^ the solution into the absOTption-tube, when the liquid alone cannot be
used. This gas is^ however, generally estimated by the indirect method, which yidds
extremely accurate results.

* Bonien*! Gatometry, p. ML

284 ANALYSIS (^VOLUMETRIC) OF GASES.

Oltfiant gas, — This gas, together with all others of the formula OH^, is easily
and rapidly absorbed by meansof anhydroas snlphuric acid, dissolved in aboat an
equal weight of the monohydrated ado. This mi^;ure is best introduced into the gais
by satarating a coke bidlet with it. The ballet is made by taking a finely powdezvd
mixture of equal parts of cannel coal and coke, or anthracite c^ and aner intro^
ducing the platinum wire, compressing as much as possible of the mixture into the
buUet-mould^ which is then carefully and slowly heated to redness. By this means a
hard and compact ball is easily formed. Before introducing it into the acid mixture,
it should always be warmed to expel any moisture present^ and after being aatnrated
with acid, must be introduced into the gas as qxdckly as possible. The ball, when with-
drawn after some hours from the eudiometer, should still giTO o£f dense white fumes,
on coming in contact with air, thus showing that an excess of acid was present.
Owing to the tension of the sulphuric acid introduced, and the sulphurous acid wliich.
is formed, the bulk of gas in the absorption-tube generally increases instead of dixni-
nishes, on first introducing the coke bullet. To remoye the add yapours thus fionnod,
after withdrawing the coke bullet, a potash-ball must be introduced.

After the coke bullet has been withdrawn, although at present there is no direct
method known for serarating and estimating singly the different hydrocarbons lutring
the general formula C'H^, still, if two of them occur together, the amount of each can
be easily determined by an indirect method to be described fiirther on.

Gases estdcatbd inddsbctlt. — ^In estimating the gases belonging to this claas by
Bunsen's method, the long eudiometer is always used. After haying completed the ab>
sorptions in the short tube, a portion only of the gas is introduced into the eudiometer,
the amount depending on the nature of the gases operated on. In most cases, a
yolume occupying about 120 mm. on the scale, will be found conyenient Gertein
precautions are, howeyer, necessary in using the tube for ei^loding gases. In order
to close securely the open end of the eumometer, so that no gas may be forced otlI
at the moment of explosion, a small round piece of cork or wood, of rather greater dia-
meter than the eudiometer, is coyered, on one side with a thidc piece of caoutchouc,
and the other is so shaped that it rests firmly on the bottom of the mercury-tiaagih.
Before exploding the gas, the eudiometer is tightly pressed down on to the caoutchouc,
and held firmly in this position by a wooden arm pressing on the top of it. In order
to preyent any air adhering to the surface of the caoutchouc, which, after the ex«
plosion, owing to the diminution of pressure, might be sucked up into the eudiometer,
the caoutchouc, before introdudng it under the mercury, should always bo moistened
with a solution of corrosiye sublimate, which causes the mercury to adhere doaely
to it, and entirely remoyes the possibility of any air being introduced into the eudio-
meter.

It will be found conyenient, as it sayes much time and calculation, to form for the
eudiometer a table of yolumes. This is done by introducing a small tube full of air,
and then reading off the height at which the mercury stands ; a second tube fuU is then
introduced, and the height of the mercury again read off, and so on till the eudiometer
is filled with air. By noting down the leyel of the mercury in the tube afte» each
addition of air, the sucoessiye differences of these numbers express the bulk of the
same amount of gas under different pressures, these pressures depending on the heiefat
of mercury in the eudiometer. r — o -e»

The following is part of a table formed in this way : —

Vol-. S^^Si;' Difference..

1 . . . . 63 .

2
3
4
5

96
131
161
187

2
43
35
30
26

The use of this table is to enable the operator to see at a glance the amount of gas
to be added when the mixture is to be exploded ; for instance, suppose the height of
the mercury in the eudiometer was 131, and the nature of the gas such that about
2 yols.^ of oxygen had to be added, in order that an explosion of me proper degree of
intensity should take place ; by referring to this table the operator would see at once
that oxygen must be added till the mercury falls to 187. As the object of the table
is only to show about how much gas has to be added under different drcnmstaneea,
any great degree of accuracy in forming it is not necessary. The readings-off of the
heights of the mercury, after each addition of air, may be made without the telescope,
and any alteration in the heights of the thermometer and barometer during the opera-
tion need not be taken into account

The explosion of the gaseous mixture is best effected by means of an electric sparse.

ANALYSIS (VOLUMETRIC) OF GASES. 283

tor obtaining trliicb, a naall LeTdao far it dinged ttom an electraphoKnu of an
electrical maehine, or else by the itiU nmplsr netkod adopted by Bnnsen, vhich con-
■Uti nanlj in robbing a laige porcelain tnbe vith a piece of silk on irhicb acme
-"■■'C*" ia tpnti. BnhnkorCra coil may also be adTantageonsIj naed fin exploding

AtfrDjren.— Tliia gta, ftom its ineombnEtible nature, can, of conna, be ettimated onlj
by lemumns all otiun vith which it is mixed, and meamniig Uie unonnt ramaining ;
bat allhoQgn it caonot be nude la combine vith dxygen, so as to remore it entiie^
from a miztnre, adll, aa ia well known, the oxidatioa of it doea often take plaoa to a
cmuidanble extent, and, if not [oijperly goarded againet, is likely to lead to Teiy
■eriooa tarom in the analysis of gases. In &ct, the discordant and ineonect letmlbl
obtained bj the earlier experimentcie on the compositian of the atmoaphere, did no
dnobt uiM in grmt meaaine Gram tbis eanse. It became then a point of great im-
portance to aseeitaiii wbethet thia oxidation of nitrogen always totdi pUce whsn mix-
tma containing it were exploded, and if not, what mnst be the lelatiTe amonnts of
eonibnstible and ineombosttble gaees present, in order that no trace of any oxide of
nitrogen abonld be formed. We are indebted to Professor Bnnsen for a seriea (tf ex-
periments on this Babject, which Tamove all nncertointy in t^e matter. By taking
mixtnrca of atmospberio air and electrolftic detonating gas in different proportions,
he has dearlT shown that when for every IDO volumes of non-a>mbtutible gas 2S to
A4 Tolamn of combustible gas are taken, no oxidation of the nitrogen takes place.

To determine the piesenee of nitrogen in a mixtnie, the fbllowing is the process to
be adopted : — HaTing removed all absorbable gases and meMored off a suitable
<]nantity in the eudiometer, some pore oi^gen is introduced, and the volnme of gas
again measaiod. An electric spark is now passed through the miiinie. Even if no
dimimition of Tolnme should ensue, *it cannot be assnmed that the gas was pure
nitiogm, as the combustible constitnents may have existed in so small a qnantitj that
the gas WM not of itself enlosive. In order to sscertoia whether this was the case.
about 40 Tohuncs of dectrolvtic detonating gas most be added for every 100 volumes

of the incombustible saa. I^ after the exploaion which then ensues, the volume of gas

■tni Rmains unaltered, only pure nitrogen could have been present in the gas examined.
The electrolytic gas above-mentionedmay be prepared by means of theif^>aratus repre-
sented in Ggore TO. The tabs A is an ordinary test-tube of lalher strong glass, filled to

the levd s *, with distilled water freed from air by

boiling, and acidulated with a few drops of sulpliuric 'V- 70.

acid. The nicai end of the tnbe is dosed with a

cmk novidad with K gas-delivery tube, and having

two idatinnm witea psaaing through it^ to the ends

of wliich *M atladied plirfJiinm plates, serving as

electrodea. When the outer extremitiee of the wires

are oonneded with the poles of a voltaic'batlery of .

two of Bnnsen's elements, and the portions of ma

evolved in the first quarter of an hour are allowed to

eacue, a chemical mixture of 2 Tols. hydrogen and

IvnL oxygen is afterwaidsobtoined, which disaj^iean

completely on explosion, so that there is no necessi^

to measure the amount of it mixed with any other

SBS. Time must, however, be allowed for it to

diffiiss iiulf tfaiangh the mixture already in the

endiometer ; fiir this pupooak half to three quBiten of

an hoar dkonld ba aUowed to el^m, after the introduction of this gas, before the et-

jilotion takes place, and oudiometai shonld be well agitated.

O^Sigm. — By exploding the mixture containing this gas with an axeeaa of hydrogen,
the qnanti^ present maj be vety occarotely determined, caie being taken that the
amount of explorare goa bears a proper relation to the total amount present, ao that
the detonstian is not so violent as to endanger the safe^ of tbe tnbe or oxidise the
nitrogen if present, and also not too feeble, as in that cose oxygen may eeeape com-
bostion. Ctee-third of the total amount of contraction caused t>j the explosion is the
quantity of on'gen which was present. Tile hydrogen used in these experiments may
be genoaled in a small flask fixnn pure dnc and dilate snlphncic add. To remove
any Inces of carbonic and hydrosulpburic adds, and to prevent sulphuric add being
carried over mechanically, the gas, as it is evolved, shonld be made to pass throu^ a
tnbe ooutaining caustic potash. The evolution of gas should always be allowed to
take place for five or ten nimttcs before any of it is passed up into the codiometer.

286 ANALYSIS (VOLUMETRIC) OF GASES.

For yer^ exact experimenta, the hydrogen should be obtained by another proccfls.
which yields an absolntely pnze gas, namely, from the electrolytic deoon^oatioa of
water. For the generation of this gas, an apparatus similar in form to that used for *
obtaining the donating gas {fia, 70), may be used. Instead, howerer; of two
platinum plates, only one is use<i, and the positive pole consists of a pUdnma inn
melted into the decomposing cell at the bottom, and there brought in contact vith a
layer of mercniy amalgamated with zinc The acid liqnid is of the same deetee of
strength as in the former apparatus. On now passing the current of a battery tbongh
it in the proper direction, pure h^dro^n is erolved, and is dried by passiiig throngh
a small Tessel oontainine sulphunc acid, or a tube containing chloride of eakanm.

Hydrogen,— Tha memod of estimating this gas is precisely the zevene of that
adopted for the estimation of oxygen. The amount of hydrogen present is repieK&ted
by } of the contraction caused by explosion. The oxygen added is best prepared from
powdored dblorate of potassium, contained in amall retorts of about tne capadtj of
eight or ten cubic centimetres.

These little retorts are easily made by blowing a bulb at the end of a pieee of g^
tubing, then introducing the powdered chlorate of potassium, and aftemrds bendine
the tube a little abore tiie bulb, so as to give it the form of a retort The open end
should also be bent upwards, in order that it may be introduced into the eudiometer.
The air is, of course, first thoroug^y expelled by erolTing a considerable amovsl of
gas before any is allowed to enter the eudiometer.

Carbonio Oxide. — ^The method of estimating this gas by absorption has already beea
explained ; it is, however, most accurately, and in most cases most easQy estimated by
exploding it with oxygen, and then absorbing the carbonic add formed by means of
potash.

lA^ht Carhuretted Eydro^tn (Marsh-gas). — This gas is alao estimated by exploding
it with oxygen, and measuring the contraction which has taken place and the amoont of
carbonic anhydride formed. This gas and all hydrocarbons containing their eaibon
and hydrogen, as they do in a condensed form, r^uire much greater dilution vith non-
combustible gases, in order to modify the violence of the exxdosion, and prereat the
oxidation of any nitrogen which may bo present. Pare Hght carburetted hydrogen
should bo diluted with from 8 to 12 volumes of air and 2 of oxygen, in order that it
may be exploded so as to yield accurate results. The object of using air instead of
merely oxygen as the diluent is, that if the gas has afterwards be examined £or
nitrogen, the amount of oxygen which would be present would probably be so lazge
that the eudiometer could not contain sufficient hydrogen to explode it.

Ethyl^ Methyl, ^o, — These hydrocarbons are easily estimated by simple eombnstion
with oxygen, and measuring the amount of carbonic acid formed, care only being
taken that they are suffidentiy diluted with incombustible gas. To pore ethyl boom '
20 times its volume of air should be added, and 6 or 7 volumes of oxygen, methyl,
on the other hand, requires only about 8 volumes of air and 2 or 3 dfoxygen. In operat'
ing with a mixture which may contain any of these gases, and of entirely nnknovn
composition, the best method of proceeding is to add at fint so much air and oxygen
that even if the whole of the gas were ethy^ an explosion of not undue violence vMild
take ^lace. If the gas should not explode on passing the spark through it, then a smill
quantity of electroTytio gas or hvdrogen must be added. In this way all danger of a
violent explosion maj be avoided. The solubility of tiie gases in strong alcohol may
sometimes be exammed with advantiue, in order to ascertain roughly vhat is the
composition of the gas operated on, and consequentiy how much diluent it is neoeeniy
to add. 1 volume of alcohol wiU dissolve some 18 volumes of ethyl, while of methyl
and hydride of ethyl it dissolves only about its own volume. With regard to these
two gases, methyl and hydride of ethyl, since they are isomeric, and in equal TQlmnei
contain the same amount of carbon and hydrogen, they cannot be distinguished by
any eudiometrical process.

The methods adopted for calculating the composition of the gas from the data which
have been thus obtamed, are as follows : — ^With the gases that are estimated directly
the nature of the calculation is easily imderstood. By taking a definite examplei the
method used in calculating the amount of combustible gases in a mixture will be rendered
very obvious. Suppose then that the gas introduced into the long eudiometer contains
hydrogen, carbonic oxide, light carburetted hydrogen, and nitrogen. Oxygen voal<i
be introduced, the mixture exploded, and the carbonic add formed absorbed ; then to
determine the amount of nitrogen present, hydrogen must be addbd in excess, and the
mixture again exploded to remove the o^gen remaining.

Let a be the amount of gas in the long eudiometer,
h „ „ after the addition of oxygen,

0 „ „ after the explosion,

ANALYSIS (VOLUMETRIC) OF GASES. 287

Let d be the amoant of gas after the alieotption of the carbonic acid,
e „ ,» after the addition of hydrogen,

/ „ „ after explosion.

From these obeerratioiis the following data are deduced : —

A, the Toliime of combustible gas. (7, the yolnme of carbonic acid formed.

J?, „ oxygen consumed. D, „ nitrogen present

^ '2'' represents the amount of oxygen which remained unconsumed by the first ex-

plosion. If this quantity be deducted £:om <?, the remainder is evidently the amount
of nitrogen present.

At the Tt)lnme of combustible gas which #bs present, is found by deducting the
amount of nitrogen from the original volume of the gas, thus : —

-('-^0

By subtracting the amount of oxygen "7*^ consumed in the second explosion from

the amount originally added, we obtain B, the amount consumed hy the combustible
g^Sthus:—

The amount of carbonic anhydride formed, is :

The Taluea of A^ B, and C? being thus hnown, it will be possible to calculate from
them that of the three unknown quantities :

X the volume of hydrogen

y „ „ light carbnretted hydrogen

jr „ „ carbonio oxide

On undergoing combustion the hydrogen and carbonic oxide combine with half
their v<dume of oxygen, whereas the marsh-gas requires twice its volume ; and ftirther,
both the carbonic oxide and marsh-gas on combustion produce a volume of carbonic
acid equal to their original volume. These data give, then, the three following equa-
tions:—

X + y '¥ f ^ A

* ' A T»

5 + - + 2y-2?
y + # - C

and from these may be deduced the value of dr, y, and ;?-»

x^ A-'C

2B-'A
y--

O-

3
2B-A

Thus is obtained the quantity of these gases present in the mixture. If another
combustible gas had be^ present, its amount might also have been determined by esti-
matins the water poduced by the explosion as well as the carbonic acid; or else
it mi^t be determmed by previously removing the carbonic oxide by subchloride of
copper in the manner alrsMy described. The aqueous Vapour in a gas is estimated by
placing the eudiometer within a larger tube^ and filling the space between the two
with steam, the heat from which, as the gas is under a mminished prepsure^ is quite
sufficient to convert the whole of the wat^ into vapour.

If two members of the olefiant gas scries OH''" should occur together, the quan-
tity of each present may be indirectly estimated in the following way : — A complete
analyns of the gas must be made in the ordinaxy manner, absorbing the olefiant gases
by nuning sulphuric acid, and exploding the combustible gases witii oxygen. A
second analysis must afterwards be made ; but, instead of introducing sulphuric add
to absorb the olefiant gas, oxy^n is added, and the whole exploded. The cUfference in
the amount of the carbonic acid formed, and in the contraction which has taken place
after the explosion, is evidently due to the olefiant gases present.

288

ANALYSIS (VOLUMETRIC) OF QASE&

Let volume of olefiant gases » A

carbonic add formed ^ B

contraction on oombustion ■> C

If the two gases are, for instance, believed to be ordinaiy olefiant eas and bat^rkne,
then, since 1 volnme of olefiant gas gives 2 volumes of carbonic add, and 2 ymam
contraction, and 1 yolume of butylene gives 4 volumes of carbonic anhydride and
3 volumes contraction, then, if x represent the former gas, and y the latter-

X + y '^ A

2« + 4y - J?

B '-2A

A"-

S ^2A

The contasetion 0 gives also a third formula :

2« + 8y » C

which, combined with the first equation, gives the values of « and y to be:

y B C- 2A

X Bu<— C -^ 2A

The values obtained ttom both these sets of equations ought to agree.

Br means of the following table, it will be easy to ascertain what formule have to be

aaopted in calculating the amount of combustible gases present in any miztora*

Name of Gaa.
•

Volume

OfGM.

Votoine of

Oxygen

oonaiimed.

Oecreuaof

Tolame after

explosion.

Vol. of

CUvODK

anhvitayi

pCOMCCL

Hydrogen .

Garbonio oxide .

Hydride of methyl

olefiant gas

Methyl

Hydnde of ethyl .

Propylene .

Sutylene •

Ethyl ....

0*5
0-5
2*0
3*0
8*5
3*5
4*5
60
6*5

1*5
0*5
2-0
2*0
2*5
2*5
2*5
3*0
3*5

If the gaseous mixture consisted, for instance^ of hydrogen, carbonic oxide, and
nitrogen, and ifA^ the volume of the gas, C the diminution after explosion, and i>
the amount of carbonic add produced, then taking x » hydrogen, y « caibonic add,
and s « nitrogen, we have :

X + y + g wm A '

2C-i)

X ■■ «

which gives :

20 •¥ 21)
8

As another example may be taken a mixture of hydrogen, cail>onic oxide, and
hydride of ethyl or methyl gas ; then, if «, y, and s represent the quantities of tbeea
gases present :

3A + 20^ 4J)

X ■■ — —

0 >■

6
3^ - 2C + 2)

3
2(7 + 2I> - 8^

* The Table ii Ukea 0*001 the Haodwortertnwh der Cbcanlo.

ANALYSIS, ZOOCHEMICAL — ANCHOIC ACID. 289

' (For farther details, see Bmisen's Gfiaometry, translated hj Eoscoe, London, 1867i
|ipL 42—114 ; Begnanlt, ** Conn ^^mentaire de chimie, Paris, 2*^ id, iy. 73 — 103 ;
Haadw. ± Chem. 2*« Anfl. i. 930—978.) W. J. R.

K>CBXKICAXk See Analysis, Obgamig; p. 250.

r» CH'^O^ — The fatty matter extracted from prains of paradise or
ooccnlus indicus (Anamirta cocadus), is composed of a solid glycende, called anamirUn
or tlearophanin^ together inth a certain quantity of a free ^tty acid. The seeds are
first freed from picrotoxine and colonring matter by digestion in ether, then exhausted
with hot etheiv and the filtered ethereal solution is exposed to a low temperature.
Anamirtin then separates in arborescent crystals, which are purified by two or three
oTstalliaations from boiling absolute alcohoL It melts at 36 or 36° C, and on cooling
smidiflfa in a wrinkled mass, but does not ciystallise. It is waxy and not fnablei
(Francis, Ann. Ch. Pharnuzlii. 264.)

Anamiriie acid is obtained by saponifying anamirtin with caustie potash and
deeontpOBxng the soap with hydrochloric acid. It then separates as a colourless oil
which gradually soHoifles in a white crystalline mass. When dissolved in boiling
dilute alcohol, it crystallises on cooling in small needles, which have a nacreous lustre
when dry. It melts at 68^ C. and soli£fies on cooling in yeiy brilliant radiatingmasses.
Aeeorduig to Francis (Ann. Ch. Pharm. xlii 264) it contains C^IP^O*. Heintz,
howeyer ^Lehrb. d. Zoochemie, pp. 387, and 1671), considers it to be identical with
stearic acid. The sodium^salt separates from boiling absolute alcohol in elongated
prisms. The aUver-aait is a white precipitate, soluble in ammonia, and soon blackened
by exposure to light. AnamirUUe of ethyl is obtained by passing hydrochloric acid
pas for seyeral hours into a hot alcoholic solution of anamirtic acid. It separates tX
the snrfiice of the liquid, in the form of a nearly colourless oil, which solidifies on cool-
ing. It is but slightly yolatile, and is partly decomposed by distillation. It contains
76*4 per cent, of carbon, and 12*69 of oxygen.

^'^^^'^'^i OZ& OS aSBBWCB OF. A solution of butyrate of ethyl in 8 or 10
times its weight of alcohol possesses the odour of the ^ine-apple (Ananassa sativa), and
is employed in confectionery and perfumery, also to imitate the flayour of rum. The
butyrate of ethyl thus used must be quite free from yolatile fatty acids. (Hofmann
Ann. Ch. Pharm. IxxxL 87.)

ILMATABMm Octahedrite. Tiiane anatase. TiO*. — A pure or nearly pure oxide
of titanium crystallised in octahedrons, belonging to the quadratic or dimetric system,
with angles of terminal edges, » 136^22 and of lateral edges 97^66. The crptals
are often very much elongated : hence the name, from iardfraais, erection. The mmeral
has an adamantine lustre, exhibiting various degrees of transluoency down to com-
plete opacity ; its colour by transmitted light is greenish-yellow ; by reflected light
yellow-grey, honer-yellow, hyacinth-red, clove-brown, and iron-black, more rarely
dark sky-blue or mdigo. Cleavage distinct parallel to the octahedral faces. Specific
mxitj 3*83 — 3*96, sometimes &er heating, 4*11 — 4*16. Hardness 5-6 — 6. It is
brittle, with sub-conchoidal fracture, and yields a colourless powder. Streak uncoloured.
Infusible before the blow-pipe. Anatase is found most abundantly at Bourg d'Oisans,
in Dauphin^ with felspar, axinite, and ilmenite. It occurs with mica slate in the
Orisons; in Bavaria near fiof ; in the Fichtelgebirg, Norway ; and in the Urals; in
idilorite in Devonshire ; with Brookite at Tremadoc, North Wales ; in Brazil, in
quartz, and in highly lustrous detached crystals. It is also said to occur in the slags
from the iron furnaces of Orange County New York. (Dana ii. 122; Handw. d.
ChemL 2*«. Aofi. i. 990). (See Bbookitb, "kvtilb, Titakio Acm.)

See AxNOTTO.

The name ^ven by Breithaupt to a hydrated silicate of magnesium
and aluminium found at Bilin m Bohemia. Its composition has not yet been ascer-
tained with accuracy, but it contains 11*6 per cent, water, and 66*7 per cent, silica.
It is softer than calc-spar, of a greenish-white colour, with mother-of-pearl lustre,
translucent at the edges. Specific gravi^ 2*26. Cleavage in one direction very dis-
tinct. A doubtful species. (Handw. d. Chem. 2** Aufi. i. 991.)

JkMOKOia ACIB. OH»«0* « (?H»0».H*.0». Lepargylic fl«V?.— Discovered by
Buck ton (Chem. Soc. Qu. J. x 166) among the products of the oxidation of Chinese
wax by nitric acid; and by Wirz (Ann. (3i. Pharm. civ. 266) among the products
of the action of nitric acid on the solid fatty acids of cocoa-nut oil.

Prewaration. — 1. When Chinese wax is heated for several hours with 4 or 6 times
its volume of nitric acid, of specific gravity 1*39, the acid which distils over being
continually poured back, a greenish distillate is obtained, containing caprylic, ccnan-
thylic, and butyric acids, and a residue consisting of anchoic acid, together with

Vol. L U

290 ANCHOIC ACID— ANCHUSIN.

saberie aadpimelic adds. On Ixnliag this rendneirith water, erapontting the llltnte
to the (aystalliauig point, prcaaing the czystalline craatB thna obtuned, vashing with
ether, and naystallisuiff firom hot water, anchoie acid cryBtalliBeB out pnre, the other
add remaining in solution. Cerotic acid alao yielda anchoie add when treated with
nitric add, hut not so readily as Chinese wax (B nekton). — 2. Several pooods of
the solid &thr adds of cocoa-nut oil (obtained by decomposing the soda soap with dilute
sulphuric acid, and tMafiHin^ off the TolatQe add), are digested with mtrie add for
sereral weeks till the oxidation is complete, and the mass solidifies in a white mstil-
line magma ; this product is dLssolTod in twice its volume of hot water ; aad the
granular mixture of suberic and anchoie adds which separates is redissolved and
recrystallised several times, at last from weak alcohol, tall the portion which iixsl
crystallises out exhibits the composition of pure anchoie add. The lnothe^liqQar
separated fiom the crystalline magma of suberic and anchoie adds, contains aerail
other adds of the series OH**— *0* (see Agedb, p. 52) viz, pimelic, adipic^ Epic, aod
Bucdnie add. (Wirz.)

ProperHes. — ^Anchoie add forms snow-white aggregated nodules (Buckton); mmd
granules resembling those of suberic add, but hard^ (Wirz). Helta between 114°
andll6° 0. (Buckton); partially at 116^, completely at 124^, and solidifies on eoolipe,
in a finely radiated nacreous mass (Wirz). At a stronger heat, it snblisus wito
partial decompodtion, emitting white inodorous vapours, which produce a veiy floflb-
eating effect when inhaled (Buckton) : hence the name (ayxf*'', to suflbcate). It
dissolves in 217*4 pts. of water ^t 18^ C. and volatalises partially when the adlntioD is
evaporated (Wirz). Hot water dissolves it readily, the solution beooming whiter and
semi-fluid on cooling (Buckton). It dissolves also in alcohol ; has an add taste and
reaction.

Anchoie add is dibasie, the formula of the neutral aochoates being OWKfJD.Q^.
It also forms add salts. AnchoaU of ammonium is an amorphous mass, which disnlTB
readily in water and alcohol, and gives off ammonia when heated. Na^nd mehodi
of potassium forms indistinct crystalline masaeay which dissolve readily in watff.
The acidaaXtf C*H"EO\ forms microscopic granules, which remain unaltered at 140° C
It dissolves in 3 pts. of cold water, more readily in hot water ; soluble also in wood-
spirit (Buckton). The sodium-aalt crystallises more readily than the potassinm-ealt,
Neutral anehoate of barium, CH'^a'0^ is obtained by neutarslisiiig the acid with
baryta-water, or with carbonate of barium, or bv precipitating a mixtnre of the
ammonium-salt and chloride of barium with aloohoL Forms a transparent film whidi
becomes dull at 100° 0. (Buckton). After drying over sulphuric add, it form a
white opaque mass, having the aspect of porcelain (Wirz). It is veiy • soliible in
water, insoluble in alcohol and in tfther (Buckton). It does not appear possiUe to
prepare an add anehoate of barium (Buckton).

The ammonium-salt forms a geUtinons predpitate with chloride of oaUhtm, whits
with acetate of lead, whitish with ferrous sulphate, light ^dc-red wi^ ferric efaloridev
and bluish-green with euprio sulphate (Wirz). It also predpitates ^^^alts, mereih
rous salts and mereurio salts (Buckton.) Anehoate of miter C*H'*Ag*0*, obtained by
predpitation from the ammonium-salt, forms a white powder which soon decomposes
when moist (Wirz) : white flocks, which are permanent at 120^ C, and dissohe 98^
ingly in water. (Buckton.)

Anehoate of Etl^l. C"H»0«-.0»H««O*.(C«H»)«.— Obtained by passing hydrocWorie
add gas into the alcoholic solution of the acid. It is a yellowish visdd oil lightef
than water and having an agreeable odour. It boils at 325^ C. (Buckton). BeooBOi
brown without distilling at 260° (Wirz).

r« or AMOKVBXO AOtDm The colouring prindple of the aflaoet
root (Anchusa tinctoria). It is extracted bv first macerating the root is cold
water, to extract the matters soluble in that liquid, then drying it in a stor^ asd
exhausting with alcohoL The solution, at first red, becomes violet bj boiling, thsa
of a greyish-green; these changes of colour may, however, be prevented by adding •
few drops of hydrochloric add. The extract is concentrated, and agitated with ether,
which then becomes charged with the colouring matter, and yidds it by evaporation in
the form of a resinous mass. Anchusin is an amorphous substance, having a deep red
colour and resinous firacture : the colour is not altered by exposuro to light It spftens
at 60° C. At a higher temperaturo, it gives off very pungent violet vaponrs, similar
to those of iodine ; at a very high temperature, it becomes carbonised. It is insoluble
in water, but dissolves in alcohol, and especially in ether ; oil of turpentine, and fixed
oils also dissolve it. According to Bolfey and Wydler (Ann. Ch. Phann. lii 141)
it contains C"»H<»0«; 7183 p. c, C; 700 H.

Nitric acid transforms anchusin into oxalic add and a bitter substanoe, OaDea-
trated sulphuric add dissolves it^ forming a solution of a beautiful amethyst coloor.

ANCHUSIN — ANEMONIN. 291

Hm 8lka2i8 iofrm with anehusin blue compoimdfl, soluble in water, lees solnble in
alcohol and ether. With subacetat^ of lead it forms a bloish-grey precipitate soluble
in aloohoL

The alcoholic solution of anehusin evaporated over the Water-bath, leaves a blackish
green residue from which water extracts a brown substance. The insoluble portion well
washed with water and then treated with ether, yields a green extract containing,
aeoording to Bollej and Wydler, C"*H**0*, and formed from anehusin by fixation of

^ r, and elimination of carbonic anhydride;

C»H»0» + 2H«0 -. C"H**0» + C0«.

Al*0».SiO«, or 8^/»0».2^a».— -A cryBtallised mineral, found
originallj in the Spanish province of Andalusia, and occurring also in Scotland, Ireland
the Pyreneo!!, and other localitiesfy in mica-slate, and others of the older rocks. It
ibims rhombic prisms, belonging to the tzimetric system, with angles of 91^ 35', and
88° 27'- Specific gravity fix)m 3-0 to 3-2. Hardness « 7*5. It is infusible before
the blowpipe : dissolves with difficulty in borax, forming a dear glass, and even less
easily in imosphoms salt. It is insoluble in acids. The alumina is generally more
or leas replaoed by the sesquioxide of iron and manganese. The minerals ekiastelite
and cyanite have the same composition as andalusite : cyanite, however, belongs to
the tridinic (doubly oblique prismatic) system, and is found in the oldest plutonic
rocks, whereas andalusite and cyanite occur in metamorphic rocks, as in mica-slate
and day-slate. Crystals are also found having the external form of andalusite, but
made up of a mass of fine czystalline grains of cyanite. (Handw. d. Ghem. 2** Aufl. i.
991 ; am. iiL 412; Dana, ii. 267.)

AmAQVIBB-^VAZ. {Cera de lot Andaqtdes.) — The wax of a peculiar species
of be^ fcnmd near the Oronoco and Amazon rivers, and used as a substitute for
ordinaiy beeswax, in the manufacture of candles, &c. According to Lewy (Ann.
Ch. Phys. [3] xiii. 468), it has a density of 0*917, melts at 77^ C, and contains 816
per cent. C, I3'5 H, and 4*8 O. It is not, however, a definite compound, but, like
ordinaxy beeswax, is a mixture of three different fats, one of which, constituting about
half the entire substance, is insoluble in alcohol, melts at T2P C, and is identical with
palm-wax. The solution obtained by boiling the original wax with alcohol deposits
on cooling, a fat which melts at 82^ C, and agrees in eveiy respect with cerosin ob-
tained from the sogar-cane ; this substance exists in the Andaquies-wax to the amount
of 46 yex cent. I^istly, the alcoholic mother-liquor yields by evaporation about 6 per
cent, of an oily £it, not yet further examined.

AjmssiH. A mineral resembling felspar in external appearance, but differing
from it eawntaally in composition. It may be represented by the general formula

^|4SiO> -> MH>.SiO' -f AlH)*.3SiO', or (regarding siHdc add as tribasic) «

ZM0,2SiC^ -¥ Z{JPC^,28i(F^ the symbol M denoting potassium, sodium, calcium,
or magnesium, which metals may replace each other m any proportions. Specific
gravitv 2733. The mineral was originally obtained from the Andes, but has since
been found in theVosges and in other localities. (Handw. d. Chem. 2^ Aufl. i. 993.)

and ASm&BOUCXa. See Habu otomb.

C»jy"0» (?) — A crystalline body, obtained from the leaves of
several spedes of anemone, viz. Anemone puUattUa, A, praiensis^ and A. nemoroaa.
Wator distilled off these leaves deposits, after some weeks, a white inodorous substance,
which softens at 160^ C, giving off water and acrid vapours. It is purified by
repeated reczystaUisation from boiling alcohoL

The eryatals bdong to the trimetaric system. In the cold, they are but sparingly
•ofaiUe in alcohol ; ether and water dissolve but little, even at a boiling heat ; the
solntions are neutraL Anemonin is a poisonous substance; appHed to the skin, it
pcoduoes slight irritation.

By the action of alkalis, anemonin is transformed into anemonio add. Boiled with
water and oxide of lead, it yields a czystalline compound, (7"ir"0".P60, soluble in
b<Hltng water. Strong sulphuric add blackens anemonin. Hydrochloric add dissolves
it without sensible alt^tion. Bv oxidising agents, such as peroxide of manganese and
solphnric add, it is converted mto formic add. Chlorine attacks it readily when
heated, forming hydrochloric add and an oily volatile body.

Anemonie Acid, — This name has been applied to an acid substance produced by
the action of baryta-water on anemonin (Lowig and Weidmann, Pogg. Ann. xlvi.
46), and likewise to on amorphous substance, which is deposited together with ane-
monin, from distilled anemone water (Schwarz, Mag. Pharxn. x. 193; xix. 168;

u 2

292 ANGELIC ACID.

Fehling; Ann. Ch. Fhann. xxxviii. 218). Both these substances toe said to consist
of anemonin together with the elements of water. (0erhardt» Traits ir. 263.)

When the root of archangel {Angelica arekangtiiea)

is exhausted with strong alcohol, and the residue left a&r i^ifrfailing off the greater
part of the alcohol is evaporated over the water-bath, a Tisdd mass is obtained, whidi,
when washed with water and digested in ether, yields a solution from which, by ev»-

? oration, a black-brown balsam is obtained, amounting to about 6 per cent, of the root
his balsam is a mixed product, and on treating it with potash-fej and dintilluig off
part of the water, a small quantity of an essential oil {angeUcoroff) separates ; on con-
tinuing to heat the mass with the alkaline liquid, a waxy body (ange^ca-fuax), is left
behind: and the liquid concentrated to a certain point jj^elds a crystalline resin,
angdidn. On distilling the residue with excess of sulphuric add, butyric add passes
over with the water, and afterwards angelic acid. (Buchner, Ann. Ch. Phaim. xliL
226.)

AVOBUO ACZD. C»H«0« = ^*^h|o, [or ^•iPO'.irO.]— This add exists

in the root of the archangel, Angelica archangdica (Buchner, Ann.Ch. Pharm. xliL
22G), and in sumbul, or moschus root, a drug imported from Asia Minor, and probably
also belonging to an umbeUiferous plant. F^rom archangel root it is prepared by boil-
ing fifty pounds of the root, cut into small pieces, with four pounds of Hme and with
water, straining through a cloth, concentrating the liquid, and distiUing it with dDute
sulphuric acid. A complex distillate is then obtained, which is neutraUsed with potuh, '
ana evaporated to dryness over the water-bath. The residue, distilled with sulphuric
acid diluted with twice its weight of water, yields first a distillate of water, acetic add,
and valerianic add, and afterwards angelic add, part of which aystaUises in the nedc
of the retort, while the rest passes into the receiver ; on leaving the distilled liquid in
a cold place for some days, the angelic add dissolved in it crystallises out. The
crystals are washed with a small quanti^ of water, and repeatedly crystallised to &ee
them ftom valerianic acid (Meyer and Zenner, Ann. Ch. Pharm. Iv. 307). — From
eunUnd root the add is obtained by exhausting the root with alcohol, evaporating the
filtered solution, boiling the residual balsam with strong potash-solution, filtering to
separate a volatile oil, mixing the brown-red alkaline filtrate with sulphnric add,
which separates a dark brown oU, and distilling this oil with water, added at int^rrals
as Ions as the distillate continues to be mixed with drops of oiL This distillate, set
aside m a cold place, depodts angelic add, which may be purified by twice saturating
it with carbonate of sodium, distilling with sulphuric add, then distilling it alone, and
lastly, boiling it for a long time to separate sumbulamic add. (Reinsch, Jahib. pr.
Phann. vii. 79.)

Angelic acid is also produced by heating the essential oil of chamomile {AnihtmiM
nobilu) — which consists of angelic aldehyde, together with a hydrocarbon (C^H*) —
with hydrate of potasdum :

C»BPO + KHO = C»H»KO« + 2H

Angelic AngeUte or

aldehyde. potaaslum.

The oil must be gently heated with pulverised and tolerably dry potash, till the
temperature of the mass rises considerably, and hydrogen begins to escape. If the
source of heat be then removed, the action goes on by-itsd^ the hydrocarbon vola-
tilises, and angelate of potassium remains mixed with the excess of hydrate. On
dissolving this reddue in water, taking off the small remaining portion of oily hydro-
carbon with a pipette, and treating the solution with sulphuric acid, angdic add rises
to the surface in the form of an oil, which solidifies in a crystalline mass on coding.
This mode of preparation is much more productive than the preceding, provided the
application of heat be discontinued at the right time. If it be continued too long, with
the view of expelling the whole of the hydrocarbon not attacked by the potash, a con-
siderable portion of the angelic add will be resolved into acetic and propionic adds :

C»H»0« + 2BP0 - C*H<0« + C^«0« + H«,

the admixture of which greatly impedes the ciystaUisation of the angelic add.
(Gerhardt, Trait* ii. 449.)

Angelic add is also produced, together with oreoselin, by treating peucedanin with
alcoholic potash :

C»H»K)» + KHO « C?WKO* + C»H«0«

Peuce- Angelate Oreoselin.

danln. ofpoiaMium.

(Wagner, J. pr. Chem. IxiL 276.)
Angelic acid crystallises in large long prisms and needles, which are eolonrless and

ANGELIC ACID— ANHYDRIDES. 29S

tnivpBrent It melts at 45^ C, boils at 190^, and distils without decomposition. It
his a peenliar aromatie odour, a sour but aromatic taste» and reddens litmus. It bums
vilh a bright and rather smoky flame. It dissolres sparmgly in cold, but abundantly
in hot wattf , whence it o^stallises in needles on cooling. In alcohol, ether, oil of
tmpentuie^ and iat oils, it dissolyes with great fiicility.
Angdic acid is monobasic, and belongs to the series of acids whose general formula

is 5 I O, the other known members of which are acrylic acid (0"), pyroterebic

(C^ hypogaeic (C"), and oleic (C").

Has i^gelates of the alJtaU-metals are soluble in water and alcohol The caldum-
salt, 0*^CaO* + HH), forms shining lamins, yery soluble in water. The soluble
angelates form with lead-^ulta, a white precipitate, CHTbO*, soluble in a lai^e
quantity of water ; with/«rrtc salts, a flesh-coloured insoluble precipitate ; with eupric
salts, a bluish-white sparingly soluble precipitate; with mercurotts nitrate, a white
precipitate, which soon turns grey and redissolres ; with mercziric chloride, no pre-
cipitate ; and with nitrate of nlver, a white precipitate, which dissolves in a large
quantity of water, forming a solution which after a while deposits metallic silver. — ^A
some^iat acid solution of oxide of silver in the boiling aqueous acid, yields, when
evaporated at the gentlest possible heat, small greyish-white crystals of the normal
silver-Bait, CH'AgO*, sometimes also laminaB of a basic salt (Meyer and Zenner.)

Amqdate of Si^l, Angdio Eiher, is obtained by diHtilling angelate of sodium with
a mixture of 1 pt strong sulphuric acid, and 2 pts. of 94 per cent, alcohol. It is a
eolourieas oily liquid, which smeUs like sour apples, has a sweetish, bumine, aromatic
taste, and excites coughing and headache when inhaled. (Beinsch and Becker,
Jafarb. pr. FharnL xvi 12.)

AHOsric Akhtdridb, or Anhydrous Angdio Acid, C"H»K>" - (OBPO)*©.—
Frodoced by the action of oxychloride of phosphorus on angelate of potassium :

6 at. angelate Oxvchloride 8 at. angelic
«f potasaium. ofpnoai^orus., anhydride.

The visrid oil resulting from the action yields, when treated with carbonate of sodium
and then with ether, a solution which leaves the anhydride on evaporation. It is a
perfectly neutral, limpid oil, heavier than water, and having a peculiar odour quite
difEbent from that of angelic add. It does not crystallise, even at the temperature of
a mixture of ice and salt. When distilled, it begins to boil at 240^ C, but the boiling-
point soon rises to 260°, and the compound is subsequentiy decomposed, yielding a
distillate of angelic acid and a neutral oil, and leaving a carbonaceous residue. — The
anhydride is birt slowly rendered add by the action of water, but dissolves readily in
strong alkaline liquids. Aqueous ammonia first converts it into a buttery mass, and
then dissolves it In contact with aniline, it becomes strongly heated, and deposits
crystals d jphtnyl-angdanUde, NJ[,C«H*,G^H'0. (Chiozza, Ann. Ch. Phys. [3] xxxix.
210.)

AMS&ZdV. A ezystalline substance obtained, according to Buchner, by treat-
ing angelica-balsam with potash (p. 287).

MMQISLMJUPTMrn A variety of vivianitei found at Azglae, in the department of the
Haote-Yienne, F^ranoe.

Native Sulphate of Lead.

B. An organic base, said by Brands to exist in tzue angustura

bazik, Outparia febrifugiL. Its existence is doubtnil.

AnnBZBMk Secondary Negative Oxides, or Oxides of Acid-radides. — ^These
bodies are also often called anhydrous acids, and are sometimes ev^ oonfounded with
adds. Ab regards their composition, they stand in the same relation to adds as oxide
of potassium, KH), to potash, JLUO ; or, eenerally, as anhydrous (secondary) oxides,
to inrdrates (primary oxides) : that is, they represent one or more atoms'of water,
«H*6 (the substance taken as the standard of comparison for all oxides), in whieh
the whole of the hydrogen is replaced by one or more negative radides; while the
eonesponding adds renresent one or more atoms of water in which the same radides
xe^ace one half of the hydrogen.

Feat example : —

Hypoehlorous anhydride ■■ CLCLO, hypochlorous add » H.CLO,

Nitric „ - N0« N0«.0, nitric „ - H.NO«.0,

Acetic „ - 0«H»O.C*H«0.0, acetic „ » H.C«H«0.0,

Benzoic „ - (rH»O.CrH»0.0, h^pzoifi „ « H.C»H»O.Q

284 ANALYSIS ^VOLUMETRIC) OF GASES.

Olefiant gas, — This gas, together with all others of the formula OH>, is easilj
and rapidly absorbed bymeansof anhTdrous sulphuric acid, dissolved in about an
equal weight of the monohydrated acid. This mi^ure is best introduced into the gaa
by saturating a coke bullet with it. The bullet is made by taking a finely powd^ed
mixture of equal parts of caanel coal and coke, or anthracite oral, and after intro-
ducing the platinum wire, compressing as much as possible of the miztore into the
bullet-mould, which is then car^ully and slowly heat^ to redness. By this means a
hard and compact ball is easily formed. Before introducing it into the add mixture,
it should always be warmed to expel any moisture present, and after being saturated
with acid, must be introduced into the gas as quickly as possible. The ball, when with-
drawn after some hours fix>m the eudiometer, should still giye off dense white fumes,
on coming in contact with air, thus showing that an excess of acid was present.
Owing to the tension of the sulphuric acid introduced, and the sulphurous acid which
is fbrmed, the bulk of gas in the absorption-tube generaUy increases instead of dimi-
nishes, on first introducing the coke bullet. To remoTe the add Tapouis thus formed,
after withdrawing the col^ buUet, a potash-ball must be introduced.

After the coke bullet has been withdrawn, although at present thero is no direct
method known for separating and estimating singly me different hydrocarbons having
the general formula C'H^, iSill, if two of them occur together, the amount of each can
be easily determined by an indirect method to be described fiirther on.

Gasbs bstqcatbd iMDHtBCTLT. — ^In estimating the gases belonging to this dass by
Bunsen's method, the long eudiometer is always used. After having completed tlie ab-
sorptions in the short tul^, a portion only of the gas is introduced into the eudiometer,
the amount depending on the nature of the gases operated on. In most cases» a
Tolume occupying about 120 mm. on the scale, will be found conyenient. Certain
precautions are, however, necessary in usins the tube for exploding gases. In order
to close securely the open end of the eumometer, so that no gas may be forced out
at the moment of explosion, a small round piece of cork or wood, of rather greater dia-
meter than the eudiometer, is covered^ on one dde with a thick piece of caoutchouc,
and the other is so shaped that it rests firmly on the bottom of the merenry-trongfa.
Before exploding the gas, the eudiometer is tightly pressed down on to the caoutchoac,
and hdd firmly in this position by a wooden arm pressing on the top of it. In order
to prevent any air adhering to the surface of the caoutchouc, which, after the ex-
plosion, owing to the diminution of pressure, might be sucked up into the eudiometer,
the caoutchouc, before introducing it under the mercury, should always bo moistened
with a solution of corrosive subhmate, which causes the mercory to adhere doeely
to it, and entirdy removes the possibility of any air being introduced into the eudio-
meter.

It will be found convenient, as it saves much time and calculation, to form for the
eudiometer a table of volumes. This is done by introdudng a small tube full of air,
and then reading off the height at which the mercury stands ; a second tube fiill is then
introduced, and the height of the mercuiy again read o£^ and so on till the eudiometer
is filled with air. By noting down the level of the mercuiy in the tube afte» each
addition of air, the successive differences of these numbers express the bulk of the
same amount of gas imder different pressures, these pressures depending on the height
of mercury in the eudiometer.

The following is part of a table formed in this way : —

Vol.. SSSV/ Dtffemie...

1 .... 63 .... 2

2
3

4
5

96
131
161
187

43
35
30
26

The use of this table is to enable the operator to see at a glance the amount of gas
to be added when the mixture is to be exploded ; for instance, suppose the height of
the mercuiy in the eudiometer was 131, and the nature of the gas such tiiat about
2 vols, of oxygen had to be added, in order that an explosion of uie proper degree of
intensity should take place ; by rdferring to this table the operator would see at once
that oxygen must be added till the mercury falls to 187. As the object of the table
is only to show about how much gas has to be added under different circumstances^
an^ great degree of accuracy in forming it is not necessary. The readings-off of the
heights of the mercuiy, after each addition of air, may be made without the telescope,
ana any alteration in the heights of the thermometer and barometer during the opera-
tion need not be taken into account

The explosion of the gaseous mixture is best effected by means of an dectric sparic.

ANALYSIS (VOIDMETEIC) OF GASES. 283

tbr obbuniDg which, ■ mull Leyden jar il chaigsil from an electropharoiu or an
' ' lieal machitui, or else hy the itill nnipler method adopted hj Bansen, irhicli eon-
mcnJj ID mbbioK a large porcelain tnbe mtb a piece of ailk on which some
ia ^nad. BohMikocff's coit may al«o be advuibigeoasl; need £ir exploding
gaao.

Before flUing tlie mdiometer with merculy, a drop of watei ehonld alwaji be intro-
duced into the top of it, so that the Tohune of gae may be lead off latvnted with
•qoeoai y^nnr.

i/itrofftn. — Thia giB,fiomitaiDeombiu>tibleDatare,eaii,of connetbeeatimatedonly
hj remoring all othen with which it ij> mixed, and meamriiig the amonnt remaimng ;
Imt Blthonf^ it cannot be made to combine with oxygen, so aa to remore it entirely
from s mixture, nill, u ia well known, the oxidation of it doea often take place to a
eomaidcT^e extent, iuhI, if not [«oparly gnarded against^ ia likely to lewl to Ttrj
■erimis eiTon in the analyiia of gaaei. In iact, the diecordant and iocoirect remltit
obtained by the earlier experimenteis on the composition of ths atmoephere, did no
doobt ariae in great meaauie from this cause. It became then a point of great im-
portutce to aaoertain whether this oiidatioQ of nitn^^en always took place when mix-
tares 1*^ twining it were exploded, and if not, what mnft be the raUtiTe amoonti of
combustible and ineombnabble gaaes present, in order that no trace of any oxide of
nitrogen ahonld be formed. We ai^ indebted to Profeamr BncBen for a eeriea of ex-
perimenta on this enlnect, which remove all nncertain^ in the matter. By tiding
mixtnna of ■tmoaphena air and electrolytic detonating gaa in different proportions,
be has dearlr abown iJiat when for eveiy 100 Tolumee of non-eombtutible gaa SB to
64 Toiomee of combnatible gas are taken, no oxidation of the nitxogen takes place.

To determine the presence of nitrogen In a miitnie, Che following is the proceea to
be adopted : — HaTing nmoTed sH abeorbable gaaea and meaaured off a snitable
quantity in the endiometer, some pnre oxygen ia introduced, and the Tolume of gaa
aoaiil meaaored. An electric spark ia now passed throngh the mixture. Eren if no
duninntioB of Tdnme ihoold ensne,-it cannot be aaanmed that tbe gas was pnre
nitragen, aa UieeombnatiUe conatitnents may have exiated in ao amall a qnontity that
the pa wis not of itself entkmre. In order to aacertain whether thia wee the case,
sbont 40 Totomea of electrolytic detonatiuff gas moat be added for erery 100 Tolnmee
of the ioeombostible gaa. ll, after tha explosion which then enanee, the Tolame of gaa
aliU remains nnalteieci, only pure nitKwen could have been present In the gaa examined.

The electnlytic gas aboTe-mentioned may be prepared by means of the appamtnirepce-
aented in figure TO. The tube jl is an orduiaiy test-tube of ratlier strong glass, filled to
the lerel i i, with diitilled water freed from air by
boiliufb and Bcidalat«d witli a few drops of sulphuric ^W- ^^■

add. The i»en end of the tnbe ia cloaed with a
coA raorided with a gaa-delireiy tnbe, and having
two rlj**""™ wires passing through it, to the ends
of <i»iich are attached pl^inum plates, Berring as
elecbodea. When tbe outer extremities of ths wiiea
tre connected with the poles of a Toltaictiattery of i
two of Bunsen's elements, and tbe portions of gaa
erolTed in the first i^nsrtac of an hour are allowed to
eaeape, a chemical mixture of 2 toIs. hydrogen and
1 voL oxygen Is afterwards obtained, which disappears
eompletelj on explosion, ao that tbereia no neoeeaity
to meaaore the amonnt of it mixed with any other
gas. Time must, however, be allowed for it to
difftaae itself throngh the mixture already in the
esdiometer ; fortius pnipoBC^ half to three quarters of

an hour ahonld be atlawed to slapsc^ after the introduction of this gas, before the ex-
plosion takes iilaca, and endiometer ahonld he well aoltated.

Oxggat — ^esptoding the nuitnre containing tbu gas with an excess of faydtogeo,
the qnantltj [ovsent may be very sccurately determined, care being taken that ths
stDonut of explosive gaa beara a proper relation to the total amonnt pieeent, ao that
the detonation is not so violent aa to endanger the safely of the tnbe or oxidise the
nitrogm if present, and also not too feeble, as in that case oxygen may escapa o
bastion. (^ie~third of the total amonnt of contraction caused bv the explosion is
"^' — ' '""-'" "»M present The bydrogon used in these ej ~ " '

s of carbonic and hydrosulphuric

carried over mechanically, the gaa. aa it is , _ — _ ,^.. „

tabe eontaioiug esnatic polaah. The evolution of ^ should always be allowed to
take place for five or ten minutes before any of it is passed up into the cndiomeler.

296 ANIMfi — ANISAMIC ACID.

brown AinericajL West Indian animi, sometimes called courbaril resins is the pro-
duce of the HyTnefUKi Courbanl^ a tree belonging to the order C^fsalpmem, growing in
the West Indies and in South America ; the other yarieties are of unknown origin.
The West Indian resin forms, yellowish-white transparent^ somewhat unctuous tean,
or sometimes larger masses ; it is brittle ; of a light pleasant taste, and yeiy agreeable
odour; hence its use in fumigation and in perfumery. It softens in the mouth, melts
easily in the fire, and bums with a bright flame. Specific gravity 1*028 (Bresson),
1*032 (Paoli). Insoluble in water, perfectly soluble in hot alcohoL Gold aloohot
dissolves about 54 per cent, of it. The soluble portion is, according to Laurent,
identical with the resin of turpentine. The insoluble portion crystallises from
boiling alcohol in slender colourless needles, consisting, according to Laurent, of
83*6 per cent. C, 11*5 H, and 4*9 0, agreemg with the formula C"H"'0. Aoootrding
to Fimol, the resin of Hymenaa Cour&rU is nearly insoluble in cold absolute alcohol,
melts at 100^ C, and^ contains 85*3 per cent, carbon, 11*5 hydrogen, and 3*2 oxygen.

Brown American anim6 softens in the mouth, and dissolves completely in oold
alcohol; specific gravity 1*0781 (Paoli). Oriental anim^ which, according to Qui-
boust, is no longer met with in commerce, is likewise perfectly soluble in oold alcohol,
has a denai^ of 1*027, and appears to consist of two resins, differing in melting
point (Paoli, Trommsdorfi^s Joum. Bd. ix. St 1 ; s. 40, 61 ; Guiboust, Kev. Scient.
xvi. 177; Laurent, Ann. Oh. Phys. [2] Izvi 815; Gerhardt^ Trait^ iii. 669;
Filhol, J. Pharm. [3] i. 801, 507.)

There is some coxifusion respecting the use of the word oniW, the French designating
eopal as rinne anting ; and denoting the West Indian anim^ or courbaril reedn, by the
term Copal or aninU tmdre»

AXTMXKF^ An organic base obtained, together with three others, odortne,
ammolinet and olanine, fi^m bone-oil {Oleum animale Dippelu), by Unverdorben in
1826 (Pogg. Ann. xi. 59 and 67). None of these bases were prepared by Unverdorben
in a state of puitty. Odoriae was afterwards obtained pure, and more exactly inves-
tigated under the name of pieoliney by Anderson, who showed that it is isomeric with
aniline, C'H'N. The other three baaes^ which were less volatile than odorine, were
probably mixtures of the homologous bases littidine, C'H*!N, and colUtUne, C?H"N,
together with other substances. (See Qm. jd. 273.)

AVZOV (from &MOV, that which goes np). — ^A term used by Faraday to denote the
element of an electrolyte, which is eliminated at the positive pole or anode ; the other
element^ which is eliminated at the negative pole or kathode, being called a kation
(icariof, that which goes down). To understand these terms, we must 8ui^x)9e the
decomposing body to bo so placed that the current (of positive electrici^) passing
througn it, shi^ be parallel to, and in the same direction with, that which is supposed
to exiBt in the earth, viz. from east to west, or in the direction of the sun's oiumal
motion. The positive pole or electrode will then be towards the east. (Faraday's
Experimental Eesearchee in Electricity, vol i. p. 196.)

JUrZBAMCZO ACIB. G*H«NO'. (Zinin, Ann. Ch. PharuL zciL 827.) — Ob-
tained by passing hydrosulphuric acid into a mixture of nitranisic acid with 8 pts.
of alcoholic ammonia. After twelve hours, when the acid is dissolved, the whole is
boiled, with occasional addition of water, till all the alcohol is driven off; it is then
filtered from the separated sulphur, and mixed with acetic acid, which precipitates
anisamic acid in long brown needles: they are obtained colourless b^ solution in water
and treatment with animal charcoaL It forms thin, brilliant, fomvsided prisma, which
dissolve but slightly even in boiling water, or in ether, but are readily soluble in alcohol.
HydroiMoric and boiling acetic acid dissolve it unchanged ; its solution in dilute nitric
acid reddens on long boUing, and by cooling deposits brown fiakes and a white pulveru-
lent substance. It melts at 180^0., and is decomposed at a highertemperature. — ^The only
anisamate that has been analysed is the silver-salt, CH'Agl^O': it is a curdy precipitate,
insoluble in water, readily soluble in ammonia and acids ; in the dry state, it may be
heated to 120° C. without decomposition, but turns brown when boiled with wat^.
The ammonium'Salt is very soluble, and crystallises with dif&culfy in fbnr-sided
tables; its aqueous solution is partially decomposed by boiling, ammonia being evolved,
and the acid crystallising out on cooling. The lead and cadmium-^alts are white
precipitates. An aqueous solution of anisamic acid does not precipitate lime- or
baryta-water, or silver-salts. With ammoniacal sulphate of copper, it gives, in ^e
oold, a light blue flocculent precipitate, which, on boiling, becomes pulvenilent, and of
a cinnamon colour.

The mode of formation of anisamic from anisic acid being analogous to that of oxy*
benzamic acid from benzoic add, it should p^haps be regaled as oxyanisanuc add,

(CHgf 1^, . F. T. C.

ANISAMINES— ANISE, OIL OF. 297

C!H*NO* [or,xather, atwamie acid, (0*H«OUq]. (Cahours,

Ann. Ch. PhjB. 13] xzii. 363.) — Obtained by treating chloride of anisyl with dry am-
monia, vheranpon neat is erolred, and the mixtare becomes a solid maas of anieamide,
vhich is BohiUe in alcohol, whence it crystalliBes bj spontaneous eyaporation in
large prisma. It is also finmed by the action of ammonia on anisate of ethyl in a
dosed TesseL F. T. C.

(Gannizzaro, Comptiend. L 1100). — These bases are pro-
duced by the action of strong alooholie ammonia on the ehlorhydrin of anisic alcohol
(C-H«OCl) :

OBHyCi + NH» - 0"H"ON + Ha

Aniwmine.

20«H*0a + NH« - C»^»0«N + 2Ha

DUnUamine.

The resulting mass is freed from sal-ammoniac by digestion in water, then dissolved
in alcohol, and the residae obtained by evaporating the alcoholic solution to dryness,
Qooaists, after washing with ether, of a mixture of the hydrochlorates of the two
bases. These hydrocUorateB are sraarated by water, the anisamine-salt being much
the more soluble of the two ; and the bases are obtained in the free state by adding
ammonia or ^tash to the solutions of the hydrochlorates, then agitating witii ether,
and evaporatmg the ethereal solution.

Anisamine oystallises in small needles, soluble in water, alcohol, and ether, and
melting with colouration above 100^ C. Dianisamine forms at first a thick oil,
which, after a few days, crystallises in white laminsB. It is soluble in alcohol and in
ether; less soluble in water than anisamine. It melts and solidifies between 82^
and Z^ C.

Both these alkaloids are strong bases. The cMoroplatinate of anisamine^
C*HiK)K.HCLPtCl*, crystallises in small fold-yellow laminse. The ektoroplatinaie
o/diammmine, G>«H>*0<N,HCa.Pta* -i- H'O is precipitated as a brown oily liquid,
gradually changing to a mass of yeUow needles.

The oonstitution of these bases maybe viewed in two different ways. If anisic
alcohol be regarded as monatomie * G*H*O.H.O, the bases then appear as ordinaxy
amines, fontaiuiTig the zadide CH'O, viz. :

Anisamine ■■ ^jH'H'O' ^^ft"^"*"^'"^ "* ^irC*H"0^'
bat if we suppose anisic alcohol to be diatomic -i(Oll*)''.H'.0*, then tiie bases must
bo regazded is hydoramines (p. 197)f viz. :

Anisamine a q]^-ds I Dianisamine » Qsj^^t '

\m See Fhezttlantsajodb, under PHEznrLAXiMB.

OX& OlPm Essence eCanis. Anisol, — The name given to the essential
oil which is obtained by distillation with water from the seeds of the common anise
(Pimpindla antsum\ and the China or star anise {JUicium aniaatum), (According to
Hees, 20 lb. of seeds yield 6^ oz. oil.) This oil contains an o^genated principle,
which, by the action of oxidising agents, is converted into hydride of anisyL The
same prmdple is found in the oils extracted from fennel (Anethum fctniculum)t and
tarra^n (Artemisia Dracuncuitu), All these oils may, therefore, be conveniently
descnbed in the same article, though they differ sliffhUy in their physical properties.
I. Oil of aniu and of fennel is a neutral, yellowish, somewhat syrupy liquid,
possessing a peculiar aromatic smell and taste. Its specific gravity varies from 0'977
to 0-99 1. It is soluble in all proportions in cold alcohol of specific gravity 0*806, and in
2*4 pts. alcohol of specific gravity 0*84 at 26° C. It appears to consist of two distinct oils,
one of which solidifies at temperatures below 10^, while the other remains fiuid at all
temperatures. Scarcely anything is known of the latter of these oils ; according to
Gerhardt (Trait^ iiL 852 et aeq.) it is isomeric with oil of turpentine. The former,
which is generally known as anethol or anise'CamphoTf has been examined by
C ah ours (Ann. Ch. Phys. [31 iii. 274). The proportion of these two constituents
varies in different specimens of tne commercial oil ; but generally the camphor composes
} of the whole. The crude oil absorbs oxygen when exposed to the air, becomes more
syrupy, and finally loses the property of solidifying by cold. In order to obtain the
camphor in a state of purity, it is freed from the Hquid oil by pressure between
folds of filtering paper, and repeatedly crystallised from alcohol of specific gravity 0*85.
It ciTstallises in 8oft> white, lustrous lamime, of specific gravity 1*014, havixig a smell
isimikr to, but weidunr and more agreeable than, that of the crude oiL It is very

298 ANISE, OIL OF.

friable, eepecudly at 0^ C. ; melts at 18^ 0., and at 222^ boils and Tolatiliflei com-
pletely, but not vithont slight coloration. Its fisimiila is G**H**0. Its 'mpoar-dani^.
taken at 338° C, is 6*19 ; at lower temperatoies, its deositj is higher. It is not affected
by exposure to the air in the solid state ; bat, if kept in a state of ftision, it graduUy
ceases to solidify on cooling, and finally reunifies completely. NUrie odd oosTerbi
it into hydride of anisyl, anisic or nitranisic acid, and oxalic add ; the jpfodnetB tut
with the concentration of the add. G^erally a yellow resinous snbstanee u alto formed,
to which Cahonrs gives the name nitranisidet and the formula C**H^I^O*)K) (?).
This is a yeiy insoluble substance, which melts at about 100° C, and is oompletely de-
composed by distillation ; when treated with a strong solution of potash, it giyes off
ammonia abundantly, and is converted into a black substance, which Gahooxs ealls
melaniaic acid. Under certain dreumstances, the action of dilute nitric add produces
an add containing 10 atoms carbon (see Akisoic Acid). When distilled with sulphtric
acid and bichromate ofpotasnum, ou of amse yields anisic and acetic adds. (Hempel,
Ann. Ch. Phaim. lix. 104.)

Strong boiling solutions of cauetic alkalis do not attack oil of anise; but when it is
heated with potash-lime in a sealed tube to ttie boiling point of the oil, apecoliar
add is formed, which appears to be isomeric with cuminic add. (Q-erhardt)

Anise-camphor treated with acid stdpMte of aodium^ is resolved into mettijl and
hydride of anisyl, C"H»*0 + HH) = 2CH» + C»H»0«. (Stadeler andWachter
Ann. Ch. Pharm. cxvi. 172.J

Anise-camphor absorbs hydrochloric acid gas abundantly, forming a liquid com-
pound, C*<>H^'0.HC1, which contains 19*8 per cent, chlorine. It absorbs cihrine
rapidly, with evolution of heat and vapours of hydrodiloric acid, forming substitation-
products, in which the number of atoms of hydrogen replaced by dilorine Taries viUi
the duration of the action of the gas. The tricUorinated compound (^chloranital)
C"H*C1"0, is a syrupy liquid, which is completely decomposea by distillatioii, aoa
from which, by the fiirther action of chlorine, aided by heat, a still higher chloniie
compoimd may be obtained. Oil of anise treated Tntli peniackhride of pkoij^onUt
yields a liquid boiling at a high temperature, probably C**H^H}1'. (Aelsmannaod
Ikraut, J. pr. Chem. Ixxvii. 490.)

When anhydrous bromine is gradually added to anise-camphor, heat and hjdro-
bromic add are evolved, and the whole becomes liquid, and finally, when the bromine
is in excess, solidifies after a time ; it is then washed with cold ether, and recrys-
tallised from boiling ether. The bromanieal, C"H'Br*0, thus obtained forms Luge
lustrous crystals, insoluble in water, very slightly soluble in alcohol ; it is deoomposed bgr
heat, decomposition commencing at about 100^ C. ; it is not fiirther acted on by bromina

When oil of anise is treated with j^ercMoride of tin or trichloride of oiUnioRy,
it thickens into a red pitchy mass, which, when boiled with water, deposits a vhite
substance, apparently isomeric witli anise-camphor. Oahours calls it anisoin. It
is also formed when oil of anise is gradually mixed with 1| pts. strong su^hmic
add, and the resulting resinous mass treated with water. It is purified by sdntion in
ether, and reprecipitation by dilute alcohoL Thus obtained, it is a white, inodonnis
solid which fiises a little above 100^ C, and, when further heated, burns with a brilHut
fiame and an aromatic smell; it is heavier than water; insoluble in wat^, almost
insoluble in alcohol, even on heating ; more soluble in ether and volatile oils. It is
soluble in. strong sulphuric acid, forznmg a red solution, whence it is rnxrecuiitated by
water. It is not attacked bv a boiling solution of caustic potash. Wnen distilled, it
partly volatilises unchangea and partly {Misses over as an isomeric oiL When oy-
stallised from its ethereal solution, it forms very small white needles. The substaaee
obtained by Will ^Ann. Ch. Pharm. Ixv. 230), by dropping oil of anise into a sboDg
solution of iodide of potassium saturated with iodine^ and treating the resulting magma
with 6 or 8 times its volume of alcohol, is, according to (jerhardt, whose statement
is confirmed by the recent experiments c^Aelsmann and Kraut {loc, ciL^ identical
with anisoin. This substance, when treated with chlorine, yields a chlonne s^^*^
tution-compound. — ^Anisoin is also produced by treating oil of anise with chloride of
benzoyL (Aelsmann and Kraut)

When anise-camphor is distilled with chloride of rinc, a volatile oil pttssj^ <^'
which after a time generally depodts crystals, volatile without decompodtioB and
not mdting at lOO'' C. Both oil and crystals hav^the same composition as tiie
original camphor; and the vapour-density of the oil is the same as that of ^
camphor. Ijie oil is readily soluble in strong sulphuric add, forming a fine crinoon
solution ; the addition of water destroys the colour, but does not predpitate anything.
B^ saturating the aqueous solution with carbonate of barium, a gummy salt is o^
tained, whose solution gives a dark violet colour with ferric salts ; both adds and
alkalis destroy the colour (Gerhardt). The same product is obtained when oil of
anise or anise-camphor is treated witii 3 — 4 pts. concentrated sulphuric add, vater

ANISHYDRAMIDE. 299

lidded, the oil which separates filtered c(S, and the aqueous filtrate saturated with
baiTtie carbonate. It a{n)eai8 to be identical with Laurent's ndphodraconate of
barium, obtained by him m>m oil of tarragon.

. 2. OH of Tarroffon (Laurent, BeTue Scient. x. 6) consists mainly of a camphor
isomeric with that of anise, and behaTing in the same manner with nitric and sul-
phuric acids and metaUic chlorides, ^e proportion of liquid oU in this essence
IS Yerj small : hence the crude oil does not boil below about 200° C, and the boiling
point gradually rises to 206°, where it remains stationaiy. Its specific gravity is
0*946 ; Tapourndensity 6*167 at 230°. When treated with chlorine, it erolves heat and,
add Tupours, and gradually becomes more synipy ; one of the products thus obtained
{ekiorids of draeonyl)^ of about the consistence of turpentine, gare on analysis per>
centagea which seem to indicate the formula C**H**01K).C1'. When treated with
aleoholic potash, this substance yielded a thick oil {eUorodraeonyl) containing 42*6
per ofsit. carbon and 3*4 per cent, hydrogen.

3. on of Bitter Fennd (C ah ours, he. cU), — ^This essence is composed of two oils,
the less Tolatale of which can readily be obtained pure by firactional distillation. Its
composition is the same as.that of anise-camphor ; but it does not solidify at 10° C. Its
specifie graTity is somewhat less than that of water ; it boils at 226° C. Treated with
nitric acid, it behaves like anise-camphor; with bromine it gives a liquid viscous pro-
duet, which is very difficult to purify. The more volatile oil appears to have the same
eomporition as oil of turpentine. It boils about 190° C. When a stream ofnitrie oxide is
led into it, it becomes thick and turbid, and on addition of alcohol of specific gravity 0*80,
yields a white, silky precipitate, which is purified by repeated washing with dcohoL This
Bubstanoe, which forms fine oystalline needles, contains 3C**H'',8NO. It is discoloured
when heated to 1 00° C, and at a higher temperature is entirely decomposed. It is scarcely
soluble in alcohol of specific gravity 0*80, rather more in absolute alcohol, still more
in ether; soluble in strong csiutic potash, and repredpitated by acids. When heated
with caustic soda, it yieldB ammonia, an oil smemng like petroleum, and a gas which
attacks the e^es. When treated with snlphydrate of ammonium in the cold, and then
by an add, it gives a predpitate which explodes slightly when heated ; the filtrate
gives an abundant blue predpitate with friric salts. It dissolves in boiling snip-
hydrate of ammonium, mrming a brown solution, and depodting sulphur, while a
strong smell of oil of bitter-almonds is evolved. It is scarcely attacked hv boiling
hyposulphite of sodium. (C h i oz s a .) f. T. C.

AVZBBnAAXZBS. Sydrure d! azoaniayl, C'^H'fC^'O*. (Oahours, Ann. Ch.
Fhys. [S'J xiv. 487.) — ^The action of ammonia upon hydride of anisyl is analogous to
that which it exerts upon the hydrates of benzoyl and salicyl, a hydramide being
formed:

80"H«0« + 2NH» « C»<BPWO« + 3BP0

Hydride of Anlshydra-

anityl. miae.

This substance is obtained by abandoning for some time a mixture of 1 voL hydride
%& anisyl, and 4 — 6 vols, of a saturated aqueous solution of ammonia, in, a dosed
vessel, when shining crystals of anishydramide gradually form, until, after some
weeks, the whole becomes a semi-solid mass. The crystals are then freed from ad-
hering liquid by pressure between folds of filtering paper, and dried. They are hsrd,
snow-white prisms, very easily powdered; ins<3uble in water, soluble in boiling
alcohol or ether, and in warm concentrated hydrochloric acid, whence they recry-
staUiae on cooling. They melt at about 120° C. When anishydnuoide is acted on by
sulphide of ammonium, a white powder is obtained, which C ah ours (Compt. rend.
XXV. 468) calls ^Jtotniw/, and Gerhardt (Trait^ iii 360) hydride <ifsulphanisyL Its
formuhi is OH^SO.

Por the probable oonstitution of anishydramide^ see Hydbaxidbs in art Ajodbs,
p. 177.

When anishjrdramide is kept for two hours at a temperature between 166°
and 170^ C, it ia converted into an isomeric alkaloid, to which the name anUitu has
been given (Bertagnini, Ann. Ch. Pharm. IxxxviiL 128). In order to obtain
this substance in a statp of purity, it is dissolved in boiling alcohol, and hydrochloric
add added to the solution, when the hydrochlorate separates out in crystals. These
are freed from the mother-liquor, decomposed by potash or ammonia, and the free base is
leoystallised from alcohol. Thus obtained, anisine forms colourless transparent prisms,
searcdy soluble dther in hot or cold water, slightly soluble in ether, readily in alcohol.
Its solution has a strong alkaline reaction and a bitter taste. Amsine forms crystallisable
salts with adds. Thehydrochhrate, CWH"N«0«.Ha, crystallises in colourless briUiant
needles, slightly soluble in water, readily in alcohol When dried at the ordinary
temperature, they contain 4C«H««N«0».HCa + 9H«0; they give oflF watej at 100° C.

300 ANISIC ACID.

The ehloroplatinate, C^H'<NK)*,HCl,Pta', obtained bj adding bidiloride of plstinim to
the hydrodilonte, forms brilliant orange-colonied scales, slightly soluble in aleohoL

F. T. C.

AVX8IO AOD. Hydrate of anuyl. l>raoonie oM, &e. CH^-(C>H«O)''.H*.0'.
(C ah ours, Ann. Ch. Phys. [3] iL 287 ; ziv. 483 ; xziii 361 ; zxv. 21 ; zzril 489;
Lanrentp Beyue Sclent x. 6, 362; Gerhard t, Ann. Ch. Phys. [3] vii. 292.)— This
acid, discoyered by Cahours in 1841, is a product of the oxidation of amBe-eui-
phor and of the crude oils of anise, fennet and tarragon. The acids obtained
from these sereral oils were at first distinguished by mfferent names; but their
identity is now clearly established. The first product of the oxidation of these sab-
stances is hydride of anisyl, which, by further oxidation, is conyerted into anisic scid.
(See Anistl, Htdhzdb of.)

Cahours prepares anisic add by boiling oil of anise with nitric arid of speofie
grayity 1*2 (23^ Baumi), when a yellow resinous substance (nitranmde) is formed,
together with anisic acid, which crystallises from the add liquid on cooling. The
crystals are washed with cold water, and dissolyed in ammonia; the ammoninrnHnlt
is repeatedly crystallised till it is colouriess, and then decomposed by acetate of lesd;
the difficultly soluble lead-salt is washed, and decomposed by sulphuretted hydrogen;
and the anisic add is dissolyed from the sulphide of lead by boiling water, cr^talltfed,
and purified (if necessary) by sublimation.

Laurent's method of preparing it from oil of tarragon is as fbllovs:— Ipioil
together with a little water, is heated in a large retort^ and 3 pts. common nitne scid
are added gradually. The mixture thickens by degrees, and is finally conyerted into
a brown, resinous, sliffhtly crystalline mass. This is washed, and extracted with hot
dilute ammonia, whi(m dissolyes all but a small quantity of a brown substance. The
ammoniacal solution is eyaporated to a syrupy when it deposits a farther portion of
the brown substance, which was held in solution by the free ammonia: if the evspon-
tion be carried too fiir, the anisate and nitranisate of ammonium contained in the
solution may be partially decomposed. The syrup is mixed with water, boiled, and
filtered through animal charcoal ; and the filtrate (neutralised, if add, by ammooia)
is eyaporated, when anisate of ammonium crystallises in rhomboidal tables^ while the
nitranisate remains in the mother-liquor. The anisate is recrystaUised two or thi«>e
times from alcohol, dissolyed in a boiUng mixture of alcohol and water, and nitne
acid added to the hot solution, which, on cooling, deposits crystals of anisic acid.
These are further purified by reczystaUisation from boiJung alcohol, and, if necessary,
by sublimation.

Anisic add may also be prepared by dropping hydride of anisyl upon fiised canstic
potash. A soft resinous mass is obtained, which, when dimolyed in water and
saturated with hydrochloric acid, depodts crystals of anidc add, which are purified
as above. If hydride of anisyl be procurable, this is the most adyantageons method,
since the formation of nitranisic acid is entirely ayoided. (Handwb.)

Anisic add crystaHises in brilliant colourless prisms, belonging to the monodioie
system, often of considerable size, with angles of 114^ and 66^. liie acute edges are
mostly truncated ; the base is replaced by two prindpal and three smaller ftoea. It
has no taste or smell ; is tolerably soluble in hot, but scarcely in cold, water ; readOy
soluble in alcohol or ether, espedally on boiling; its solution reddens litmus feeUy.
It fuses at 175^ C, and solidifies on cooling to a crystalline mass; at a higher tern-
pcrature it sublimes without decomposition into snow-white needles.

It is isomeric with salicylate of methyL

It is yiolenily attacked by chlorine and bromine fsee below, SvBBrrrvnatt'VwcfDVca).
Hot concentrated nitric acid conyerts it into mtranisic add. Fuming nitrie add
converts it into dinitranisol or trinitranisol (see Aiosol), the product varying with
the duration of the reaction and the proportion of the reagants. If heat be applied,
a third substance, chrysanidc add, isomeric with trinitranisol, is eimnltaneonslT
formed. A mixture of sulphuric and fuming nitric adds converts it into trinitranisol
Perchloride of phosphorus attacks it violently, forming chloride of anisyl, chloride
phosphoryl, ana hydrochloric add. When distilled over caustic baryta, it is decom-
posed into carbonic anhydride and phenate of methyl (anisol).

CBPO* « C0» + C^CH»)0.

Anlsatei* Anisic add is usually considered as monobasic ; but it is probably
diatomic, like glycollic and lactic adds. The general formula of the anisates is O'H^O'
(see Amsn.). They are mostly crystallisable : the alkaline and earthy salts an
soluble, and the addition of a mineral acid separates anisic add from their solutions.

The alufmniumsalt crystallises slowly in fine needles, when a dilute solution of
alum is added to anisate of ammonium.

The ammimium-'ialt, CH*(KH*)0', is very soluble, and crystallises in large rhomhw

ANISIC ACID. 301

tables, the angles of vhose base are 84^ and 96^. Espoeed to the air, they become
opaf^ne : heated to 99^ C. in Tacoo^ they lose ammonia, pure anisic acid being left
behind.

The barium satt^ -when nrepared direct^ by boiling anirie acid with bai7ta« crys-
talliaea fixat in needles, and then in riiomboidal scales. Chloride of barium does not
pRcipttate anisateof ammoninm immediately, but after some time^ a difficultly soluble
oyatalline precipitate forma.

The ealeiitm-iaiU, Chloride of calcium precipitates anisate of ammonium imme-
diately; if the sohitioDS are dilute, it a^rstallises in groups of needles.

The eppper-Moit is a bluish-white precipitate.

The /erriosatt is a yellow precipitate, composed of microscopic needles.

The iead-^alt is a white prodpitate, soluble in hot water, wnenoe it dystallises on
cooling in Amiiig scales, which retain | atom of water after drying at 12C^.

The magneuumrMolt is solnble.

The manganue-9alt crystallises slowly from a mixture of sulphate of manganese and

The mercuric^ mereuroua, and sitit-$aits are white precipitates ; the first crystallises
from hot water in microscopic needles.

Th/b jDoiasnum-mUt oystallises in rhomboidal or hexagonal tables ; the sodium-salt
inneedlea.

The sUver-'SaU is a white precipitate, crystaUising from hot water in fine needles, or
pearly scales.

The MtronHum'Sali crystallises gradually in small hexagonal or rectangular laminaB,
frcfoi a mixture of chloride of strontium and anisate of ammonium.

Axis 10 Etrbbs. (C a hours, Ann. Ch. Phys. [8] xiv. 492.)

Anisaf of Methyl, 0^>«0* - 0'!H'(CH»)0«.— A mixture of 2 pts. anhydrous
'vood-qnrit, 1 pt anisic add, and 1 pt. strong snlphuric add, assumes an intense
earmine-red eoumr ; on the application of a gentle heat, wood-spirit first passes oyer,
and then a hea^ oil, which solidifies in the receiyer. This is anisate of methyL It
is purified hf washing with hot sodic carbonate, and with water, and reoystalliaation
from alcohol or ether. Thus prepared, it forms large, white, shining scales, which
m^ about 47^ C, and solidify on cooling to a errstalline mass ; at a higher temperature
it distils undecomposed. It has a faint smell, resembling that of oil of anise, and
a buning taste. It is insoluble in hot or cold wat«r ; readily soluble in alcohol or
ether, especially on boiling. Unlike salicylate of methyl, it does not combine with
potash or soda ; but, when boiled with a strong solution of dther alkali, is decomposed
into mcthylie alcohol and an alkaline anisate. Aqueous ammonia does not dissolye
it, hot gndually decomposes it into methylic alcohol and anisamide, the Litter of
which erystalliseB out^ bromine, chlorine, and fuminff nitric add attack it yiolentiy,
£>iming raspeetiyely the methyl-salts of the corresponcung substitution-add.

Anisate of Ethyl C»*H»K)» - C?H'(C»H»)0».— When a solution of 1 pt anisic
add in about 6 pts. absolute alcohol is satunited at about 60° C. with hydrochloric add
gas, a fuming liquid is obtained, whence water predpitates only anisic add. On
diafjTKng this liquid chloride, hydrate, and finally anisate of ethyl pass oyer ; and on
adding water to the distillate, the latter product separates out as a heayy oil, which
is washed with sodic carbonate, dried over chloride of caldum, and rectified oyer
oxide of lead. It is a colourless oily liquid, heayier than water, with a smell like
that of oil of anise, and a warm aromatic taste. It boils between 250° C. and 255°, is
insoluble in water, readily soluble in alcohol and ether. It may be kept unchanged
in dosed yessels ; but, when exposed to the air, it gradually becomes add. Its decom-
positions are precisely analogous to those of the methyl-salt

SubsOtuiumHUrifKUives of Anisio Add,

BnovAKisic Acid. Bromodraconetic acid (Laurent). CH'BrO*. — When
powdered anisic add is treated with bromine, heat is eyolyed, together with abundance
of hydrobromie add ; the jxroduct is washed with water, and ciystallised from boiling
alcohoL Bromanisic add is thus obtained in white shining needles, slightiy soluble
in hot water, readily in hot alcohol or ether. It melts at 205° C, and sublimes in
iridescent Isinina*. When distilled with lime, it yields carbonic anhydride and bro-
maniaoL The alkaline bromanisates are soluble; the potassium and sodium-salts
yield bromaniaol by dry distillation. In their solution, lead-, silyer-, barium-, strontium-,
and caldnm-salts eiye white predpitates ; the last three are not quite insoluble, but
oystalliae gradually from dilute solutions.

Bromanisate of Methyl, OH*(CH*)BrO*, is obtained by dropping bromine on the
anisate, and treating the yellowish-red product as in the cose of bromanisic acid. Also

902 ANISIC ACm.

in tlie same maimer aa the aniaate, twmianiaic hang anbititiited tat anine add. The
mixture is boOed in a vater-bath &r a quarter of an hour, and vater added, vImb the
bromanisate separatea in flakes, which are washed with dilate ammonis and oyt-
taUiaed from hot aloohoL It forms eoloorieas tranaparent prisma, which meit at a
gentle heat: it ia inaolnble in water; solnble, eapedallj on heatini^ in aloohol and
wood-apirit ; lesa sofatble in ether. Bj boiU^ potash it ia deoomposed like tiie

anisate.

Bromamsate of Etiyl, 0^'(C^*)BtO*, ia obtained bytiiesame process as asisate
of ethjl, anisic being replaced bj bromaniaie add; or bj treating anisate of ethyl with
bromine. It ia pmfied in the same way aa the meUiyl-aalL It fonns long, vfaite,
shining needles, maolnble in water, solaUe in ahx^l or ether: it ftues at a gentie
heat^ and snblimes nndecomposed. It ia deeon^Msed bj boiling potash, and is not
attacked bj excess of bromine.

Chlobakisio Acid, 0*H^O', is obtained bypassing chlorine orer anisie add
in fiision ; the product is washed with water, and dyatalliaed from alcohol of 95
per cent, It forms fine shining needles, scarcely solnble in water, readify in alcohol
or ether. It melts at abont 176^ C, and may be snblimed without deeompoiitifln. It
is not acted upon by chlorine, even in sonshine. Strong sal{^nric aod dissolm
it by aid of gentle heat ; it reczystalHses from the sohition on oooHng, or is at ooee
precipitated by water. When heated with baiyta, it is decomposed IBlc saisie add.
The metallic chloranisates resemble the corresponding bromanisates in solulHlit^ and
general properties. The chlcranisaUs of meHtyl and ethyl are obtained by snbmitting
the ooiresponding anisates to the action of dry chlorine ; the latter may also be prepared
in a simihur way to anisate of ethyL Both are crystalline oompoundsi iioolaUe ia
water, soluble in alcohol or ether, and decomposed by boiling potash.

NiTBAHisio Acid, 0'H'(K0')0', ia farmed by the action of strong winn nitrie
acid on aniaie add It is nsoally prepared hy healing oil of anise with nitrie add of
spedfie mvity 1*33 (36^ Baom^), until the oijy aubstsmoe which first forms has eomr
pietely £sappeared. The addition of water then predpitates yellowiah flakes of mpat
nitranisic add. This is purifled by washing with water, dmsolying in afnawnia, »•
crystallising the ammonium-salt tiU it is colourless, dissolying it in water, predpitatxng
the add by nitric or hydrochloric add, and waahing it repeatedly with water. It is
also formed in Laurent s process for preparing anide add from oil of taitagoo, remaiit-
ing in the ammoniacal mother^liquor whence anisate of ammonium has oTStallifled
out It is obtained thence by adding nitric add, washing the predpitates and boiling
it for half an hour with nitric add ; the add solution depMits on cooling ahoit prisms
of nitranisic add, which are washed with water, and crystallised from hot alcohol
Nitranisic acid crystallises in small shining needles, of a ali^t yellow tinge^ irithovt
taste or smelL It is scaredy soluble eyen in hot water; re^ily in alcohol or ether.
It melts between 176*' and 180<>. When carefolly heated further, it partly sahliiBee,
partly blackens, and is decomposed ; if heated suddenly, it decomposes at onoe, with
eyolution of light. It is not attacked by chlorine, bromine, or strong nitrie add; bj
fuming nitric add, it is acted on in the same way as anidc add. When heated with
perchloride of phoephoros, it yields a dark yellow oil, with a yery high boiling point,
which is probably chloride of nitranisyl, C^^NO«)0*,a (Ca hours). An alcoholic
solution ik sulphide of ammonium conyerts it into anisamic add (p. 291^. Aoeordiog
to Laurent {Joe, cit.) nitranisic add combines, atom for atom, with anisic, ehloranifie,
and bromanidc adds, forming peculiar dibasic adds.

The alkaline nitranisatcs are soluble and crystallisable : the ammonium-salt erys-
tallises in fine needles, grouped in spheres ; it is soluble in alcohoL The alkaline-
earthy nitzanisates are difficultly soluble; those of the hea^y metals genenllj
insoluble.

Nitranisate of methyl is prepared by a process analogous to that described in the
case of anisate of meuiyl ; or by dissolyinff anisate of methyl in fuming nitric acid,
adding water, and crystallisine the preapitate fit>m alcohol. It forms beantifal
large shining tables of a yellowish hue. It is insoluble in water ; readily soluble in
hot alcohol or wood-spirit, whence it separates almost completdy on cooling. It m^^
at about 100^ C, and sublimes nndecomposed.

Nitranuate of ethyl is prepared either by dissolying anisate of ethyl in an eqnil
yolume of fuminff nitric acid, or by a process analogous to that described in the cue
of anisate of me^yl. In the latter case, the mixture must be kept at a tempetatnre of
60^ — 70^^ C., while it is saturated with hydrochloric acid. The compound is precipitated
by water, washed with dilate ammonia, and crystallised from alcohoL It exactly
resembles the methyl-salt in appearance, and solubility in water and alcohol, and
meltB between 98^ and 100° 0. Strong sulphuric acid dissolves it in the cold, mon
readily on heating ; it rartly recrystallises as the solution cools, and is eompletel/
predpitated by water. Bromine exerts no action upon it.

ANISIC ALCOHOL. 303

Trimitraniaie Aeid, G'H^NO*)*0', ib obtained bv trefttiog aniaie aeid in ihe
eold trith a mbttiue of fiuning nitric and fdming sulphuric acid, and diluting the
mixtore with S to 10 times its volume of vater. ft forms veiy beautiful salts with
tiio alkalis, especially with ammonia and potash.

SvtPHAirisic Acid, CHW.SO*. (Zervas, Ann, Cb. Pharm. ciii. 339; Lim-
pricht^ Gm. Handb. xiiL 128.) — Obtained by heating anisic add with common
solphuiic add to 110^ G. or with fuming sulphuric add to 100^, diluting the mixture
wiUi water, adding carbonate of lead, fitenng at the boilins heat, and boiling the
iDSoluUe residue with water ss long as the filtered liquid yi^ds erystals of the lead-
salt on cooling. These, when decomposed bj sulphuretted hydrogen, yield the add
(Zeryas). Limpricht treats anisic acid with sulphuric anhyc&ide.

Sulphanisic add, obtained by slow eyaporation of the aqueous solution, forms
needles which are permanent in the air, and gixe off 6*9 per cent (1 at) water at
100^ C and suffer no further decomposition below 170^. The aqueous solution may be
boiled without decomposition.

Solpbanisic add is dibasic. The aulphanisaUs of ammonium, potassium, and
■odium crystallise readily, tbe first in long slender needles. The barivm-aali,
C^'Ba*0*.SO' + 8HK), obtained b^ saturating the add witJi carbonate of barium,
fanoB fine oystals, which, after drying over sulphuric add, give off 16-9 per cent
(8 at} water at 180^ C. It dissolves easily in water, and is precipitated hjr alcohol.
The maanenum-9alt forms very soluble needles. The normal iead-salt, CH'Pb*0*.SO*
4. 8H*0, foarms beautifid needles, which give off their water at 180^ G. The acid
Uad-aaU, G^H'FbO'.SO* + HH), forms nodular crystals ; easily soluble in water.

The wUver^aaU forms nodular crystals, sparingly soluble in water. According to
T^demMt the solubility of the barium and lead-salts is diminished by repeated
oystaUisation. F. T. C.

JUnsie AX490BO&. Hydrate of AmaaJtyl, C^H^K)' - C^H*O.H.O. (Can-
nizzaro and Bertagnini, Aim. Oh. Pharm. zcviii 188.) — Formed from Hydride
of anisyl in the same way as benzoic alcohol from hydride of benzoyl. When
a sdlntion of pure hydride of anisyl in an equal yolume of alcohol is mixed with
three times its bulk of alcoholic potash of about 7^ Beaum^ (specific gravity
1*052), a slight evolution of heat takes place, and anisic alcohol and anisate
of potassium are formed, the latter in such quantity that the mixture shortly
becomes a crystalline pulp. (20"HK)« + KHO - C^ITKO" + C^»0«.) After 10
or 12 hours, the alcohol is distilled off in a water-bath, and the reddue is suspended in
water, and extracted with hot ether. On evaporating the ethereal solution, a brown
oil is obtained, and on distilling the oil, anisic alcohol passes over at about 260^0., as
a cokmrlesB liquid, which crystallises on cooling. This product generally contains some
hydride of amsyl, which may be detected by agitating it with a concentrated solution
of add sulphite of sodium (see Ahistl, Htdbtob of). To purify it, it is treated again
with a small (quantity of alcoholic potash, distilled in carbonic anhydride, and the
oystalline distulate pressed between filter-paper.

Anisic alcohol oystallises in hard, white, shining needles. It distils undecomposed
between 248^ and 260^ C, and melts at 23^, when anhydrous, but at much lower
temperatures when moirt. It is heavier than water, has a faint spirituous, sweetish
smell, and a burning taste like that of oil of anise. At ordinary temperatures, it
remains unaltered in the air ; but when heated nearly to its boiling point it, absorbs
ozyeen, and is converted into hydride of ani^L Oxidising agents (as platinum-
UaoE, nitric add, ^^^ convert it, first into hvdnde of anisyl, then into anisic acid.
Potasdnm dissohres in it with evolution of hvdrogea Sulphuric add, even when
moderately concentrated, or phosphoric anhydride, converts it into a rednous mass.
Heated with chloride of zinc, it ;pelds water, and an oily liquid, which solidifies on
cooling into a hard, transparent, vitreous mass, which melts at 100^ 0., and is insoluble
in water and sloohol, but soluble in bisulphide of carbon.

When treated with hydrochloric add gas, it forms water and a colourless liquid,
havvDg a fruity smell anda burning taste. This substance is its hydrochloric ether,
or chloride af amUalyl, CH'O.Ol, and is decomposed by alcoholic ammonia yielding
chloride of ammonium, and the hydrochlorates of anisamine and dianisamine (p. 297).

If, as is probable from its analogy to salicylic add, anisic add be r^;arded as
dibasie, anisic alcohol becomes diatomic, (CH').H'.O' ; and chloride of anisahrl will be

^nt analogous to glycolic chlorhydrin. F. T. C.

AVmo AWHTBBlBa. (^^H^^O* - 0'H'0*.C"H'0«0. (Pisani, Ann. Oh.
Pharm. ciL 284.) — Formed by the action of oxychloride of phosphorus on div anisate of
sodium ; the mass is washed with wat^r, and the insoluble reddue cxystallised from
ether. It Ibrms silky needles, soluble in alcohol or other, insoluble in water or

304 ANISIDINK

aqueous alkalis ; it melts at 99°C., and distils at a higher temperature. ]^ long
boiling with water or aqueous alkalis, it is oonyerted into anisic acid. F. T. CL

(MethylphenicUne, . Gerh.) C'BPNO - N.C'H'O.H'. (Cahours,
Ann. Ch. Phjs. [31 zxvii 443. )P— The action of sulphide of ammonium on the nitro-
deriyatiTe of anisol gives rise to the formation of peculiar organic bases. Anisidine is
obtained by dissolving nitranisol in an alcoholic solution of sulphide of ammonium,
evaporating at a gentle heat to a quarter of its volume, adding a slight excei» of
hydrochloric acid to the brown residue, separating the sulphur by addition of water,
and filtering. The yellow-brown filtrate deposits on evaporation, needles of hydro-
chlorate of anisidine, which are dried with filter paper and distilled with a strong
solution of potash, when anisidine passes over with the aqueous vapour in the form of
an oil, whi<m solidifies on cooling.

The properties of anisidine but are imperfectly known. It combines with acids, form-
ing salts. The hydrochlorate forms fine colourless needles, soluble in water and alcohoL
When a hot concentrated solution of this salt is mixed with a concentrated solution of
dichloride of platinum, the chlaroplatinate separates on cooling in yellow needles. The
nitrate, sulphate, and oxalate are ciystallisable.

The products of the action of sulphide of ammonium on the higher nitro-derivatives
of anisol may be regarded as nitro-derivatives of anisidine, though it is not known
whether they can be formed by the action of nitric acid on anisidine.

NiTBANisiDiNB (MethylnitropherUdine, Gerh.J CBTOK)* - C^NO«)NO.—
Preparedby aprocesssimilar to that described for anisioine, dinitzanisol beingsubstitnted
for nitranisoL The filtrate is mixed with ammonia, and the preci{>itate thus formed
is washed with water, and crystallised from boiling alcohol. Nitranisidine forms lon^
garnet-red, shining needles, which are insoluble in cold, soluble in boiling, water;
soluble in boiling alcohol, whence it separates almost entirely on cooling ; also in
ether, especially u heated. It melts at a gentle heat» and on cooling forms a radiated
mass ; wnen heated gradually to a higher temperature, it gives off yellow fumes, wludi
condense into yellow needles. Bromine atta<^ it violenuy, forming a resinous mass,
which has no alkaline properties. Fuming nitric acid decom{}Ose8 it violently, yielding a
viscous mass, insoluble in acids. The chlorides of benzoyl, cinnamyl, cumyl, and anisjl
attack it when gently heated, forming hydrochloric acid, and compounds analogous to
benzamide, which are described by Cahours under the names of bemonitramsidf^
C'«H"N«0* « N.C'H*O.CH«(NO«)O.H., cinnitraniside, C"H"N*0*, &c These bodies
are obtained pure by successively washing the products of these reactions with water,
hydrochloric acid, and dilute potash, and crystallising from boiUng alcohol; they are
insoluble in water or in cold alcohoL

Nitranisidine dissolves readily in acids, and with many of them forms ciystalline
salts. The hydrochlorate and hydrohromate, when pure, form colourless needles, slightly
soluble in cold, readily in boiling, water. The chloraplatinaie separates in orange-
brown needles from a mixture of hot concentrated solution solutions of the hydro-
chlorate and dichloride of platinum. The nUj^hate forms concentric groi^M of silky
needles, readily soluble in water, especially in water containing sulphuric acid. The
nitrate forms large needles, much more soluble in hot than in cold water.

Dinitr anisidine {Methyl-dinitrophenidine, Gerh.) CH^«0» - CrTB[*(NO«)«yO.
— ^Prepared precisely like nitranisidine, trinitranisol being substituted for dmitranisol.
When dry, it is an amorphous powder, of a bright red or violet-red colour, according to
the concentration of the solution from which it was precipitated. It is almost insoluble
in cold water, very slightly in hot water, forming an oranee solution : slightly soluble in
cold, moderately in not alcohol, and separates on coding in violet-black crystals;
slightly soluble m hot ether. It meks at a gentle heat, and solidifies on cooling into a
jadiated, violet-black, crystalline mass. It is much less basic in its properties than the
foregping compound : it forms crystallisable salto with hydrochloric, nitric, and sul-
phuric acids, if the acids be employed in excess, but these compounds are decom-
posed by water. When heated with fuming nitric acid, it is violently attacked, and
yields a yellowish brown resinous mass, which dissolves in potash, forming an intensely
brown solution. F. T. C.

See Anisetdbaxidb.

(OIO ACZD. C>«H>>0«. (Limpricht and Bitter, Ann. Ch. Pharm. xcviL
364.) — A product of the oxidation of oil of star-anise (probably also of oil of anise, tar-
ragon, fennel, &c.). The oil is heated with nitric acid, of specific gravity 1*2, and the
oily layer which sinks to the bottom of the mixture is agitated with a warm solution
of acid sulphite of sodium, whence anisoate of sodium crystelUses on cooling. To the
purified ciystalB, enough sulphuric acid is added to decompose the salt, the whole eva-

ANISOL. 305

panted to diynefn, and the add extracted from the residue by absolute alcohoL It
erjrstallisi^ from its aqueous solution in small laminae, which have a strong acid reaction,
and are Teiy soluble in water, alcohol, and ether; they melt at about 120° C, and are
not Tolatfle without decomposition.

Anifloates are mostly readily soluble. The sodium^aalt, CH'^NaO*, and the barium-
tali, form white crystalline nodules. The sUver'Balt forms soluble nodules, and speedily
blackens when moist F. T. C.

Stadeler and Wachter (Ann. Gh. Pharm. czyi. 169) regard this acid as identical
with tMamsoie acidy C^*H''SO^the product which they obtam by treating anise-cam-
i^or with nitric acid of specific ^rayity 1'106, then distilling and agitating the distil-
late with acid sulphite of sodium and alcohoL The atomic weights of the two acids
are nearly equal (anisoic acid = 234 ; thianisoic acid a 230), so that the determina-
tions of carbon and metal in Limpricht and Hitt«r^s analyses of the silver and barium-
salts will agree with the one formula as well as with the other. Moreover in Limpricht
and Bitter s analyses of both these salts, the amount of hydrogen found was much too
low for tho formula of anisoic acid (in the barium-salt 5*44 per cent, by calculation
5*65 ; in the silver-salt 4*0 per cent, calculation 4*98), and the absence of sulphur
was not established by direct experiment (See Thianisoic Acid.)

kXV« See Aman, On. of.

(0&. Fkenate of TMthyl Dracol CrHK) « C^»(CH«)0. (Cahours, Ann.
<3i. Phys. [3] iL 274 ; x. 353 ; xxyii. 439.) — This compound is formed by the
aedon of caustic baiyta on anisic acid, or on its isomer, salicylate of methyl : also
directly from phenic acid, by the substitution of methyl for 1 at hydrogen. It may
be obtained in various ways. Anisic acid distilled with excess of caustic baryta or
lime, is decomposed, anisol passing over as a volatile oil: CHK)* + BaK) » C'HK) +
CO'Ba^ The same result follows when salicylate of methyl is dropped on finely
powdered baryta, and the mixture gently distilled. A third method is to heat phenate
ofpotassium with iodide of methyl in a sealed tube, to 1000—120° C. C*H*KO +
Chi - C*H»(CH")0. + KL The product of either of these reactions is washed with
dilute potash and with water, and rectified over chloride of calcium.

Anisol is a colourless, very mobile liquid, with a pleasant aromatic smell. It is in-
soluble in water, very soluble in alcohol and ether, insoluble in potash. Its specific
gravity at 16° C. is 0*991 ; it boils at 162° C, and distils undecomposed. It is isomeric
with bensoic alcohol and tauiylic acid.

It may be distilled over phosphoric anhydride without decomposition. It dissolves
entirely in strong sulphuric acid, and is not precipitated by water, a copulated acid
beins formed. This acid, which Cahours calls siUphanisoliCj and Gerhardt methyl'
sulpkop^enie acid, has the formula C^%0\ By saturating the add liquid with
canwnate of barium, a crystalline barium-salt is obtained, which contains 1 at. barium.
If fuming sulphuric acid be employed, not in excess, the addition of water separates
ciystalline flakes of a neutral bcnly, which Cahours caUs sulphanisolide. Its formula
is C"H'*SO^ ; it is to sulphanisolic acid as sulphate of ethyl is to ethyl-sulphuric acid.
This body is best ob^ined by passing the vapour of sulphuric anhydride into arti-
fioally cooled anisol, and adding water to the mixture ; sulphanisolide is then de-
poeitra in fine needles, which are recrystallised from alcohol, while sulphanisolic acid
remains in solution. It forms soft silvery prisms, insoluble in water, soluble in alcohol
and ether. It melts at a gentle heat and sublimes undecomposed. Strong sulphuric
add converts it into sulphanisolic add.

SuBSTiTiTTiON-DBBivATiVBS OF Anisol. — Chlorino and bromine form with
anisol cnrstalline substitution-compounds. The chlorine-compounds have not been
examined; there are two bromine-compounds, bromaniaol^ CH^BrO, and dihromanisol^
C^*Br*0. The latter is soluble in boiling alcohol, whence it ciystallises in brillant
scales. It melts at 54° C, and at* a higher temperature sublimes entirely in small

whining tables.

Fuming nitric add acts oiergetically on anisol, forming three distinct nitro-com-
pooads, Nitranisdy Dinitranisoly and Trinitraniscl^ according to the proportions of the
reagents and the duration of the reaction. Nitranisd, C'H*(N0')6, is prepared by
ad£ng fuming nitric add by small portions to anisol, the mixture being Kept cool by
ice. A bluish-black oilv liquid is thus obtained, which is washed with dilute potash,
and rectified over chloride of calcium. Anisol diistils over first, and when the boiling
point remains constant at about 260° C, the receiver is changed. Nitranisol is a clear
amber-coloured liquid, heavier than and insoluble in water, with an aromatic smell,
something like that of bitter-almond oiL It boils between 262° and 264° C. It is
not attacked by aqueous potash, even on heating. When gently heated with strong
sulphuric add, it dissolves, and separates out again on the addition of water. When
boated with fiuning nitric add, it is successively converted into di- and tri-nitranisol.

Vol. L X

806 ANISYL.

Dinitranisolf CH*(NO')*0, is prepared by boiling anisol for a few miniftes with
excess of fuming nitric acid : on adding water, a yellow liquid is separated, which
soon solidifies into a yeUow mass, which is redystallised from boiling aloohoL It is
also obtaine<l b^ heating anisic acid to 90^ — 100^ C, for about half an hour, with two
or three times its weight of fuming nitric acid : ehiysanisic acid forma at the same time,
and is removed by dilute potash. Dinitranisol crystalliaes in long pale yellow needleo,
insoluble eyen in boiling water, soluble in alcohol and ether. It melts at about 86^ C^
and sublimes undeoomposed. Aqueous potash does not attack it, eyen on boiling,
imless the solution be yery strong, and eyen then long boiling is required : when
boiled with alcoholic potasn, it is speedily decomposed, dinitrophenate of potasnam
being formed.

Trinitranisol, CH'(NO')'0« is formed when anisol, anisic, or nitranisic acid is
heated with a mixture of equal parts of strong sulphuric and fuming nitric add.
Anisic acid is generally employed for its preparation. The mixture, which at fijnst is
clear and colourless, is gently heated till it begins to become turbid, carbonic anhy-
dride being copiously given off. The heat is then removed, when there gradnaily
collects on the surface an oil, which solidifies on cooling. A large quantitr of wat^
is then added, and the solid product is washed with boilii^ water, and crystallised from
a mixture of equal parts of alcohol and ether. The reaction is complete if 15 pts.
of the mixed acids be employed for 1 pt. anisic acid. Trinitranisol ciystalliaea in
yellowish, very brilliant tables, insoluble in water, soluble in hot alcohol or in ether.
It melts at 6B9 — 60^ C, and if carefully heated, sublimes. Warm sulphuric or nitric
acid dissolves without decomposing it. Aqueous ammonia or dilute potash, does not
attack it, even on boiling ; but moderately strong aqueous potash gives it an intense
brown-red colour, and completely decomposes it on boiling, forming a slightly soluble
potassium-salt of an acid, which is isomeric with, but, according to Cahours, distinct
ttom picric, or trinitrophenic acid, which he designates picranisic acid.

All the nitro-derivatives of anisol are readily attacked by alcoholic sulphide of am-
monium, sulphur being separated, and anisidine and its nitro-derivativeB being formed.

F.T. a

The name given by Brandos and Beimann to a brown product,
obtained b^ extracting anise-see^ after previous treatment with alcohol, water, and
hydrochloric acid, with aqueous potash, and precipitating the alkaline solution by acetic
acid. F. T. C.

C^*H"NO*. — ^An add analogous to hippuric add, produeed
by the action of chloride of anisyl on the silver-compound of glyoocoll (CH^AgNO* +
C«H'0«C1 - Aga + C»«H»»NO«). Acids, with aid of heat, convert it into ^ycocoU
and anisic acid. (Cahours, Ann. Ch. Fharm. ciii. 90.)

AVUTXte CH'O'. — ^A hypothetical radide, supposed to be contained in anisic
add, hydride of anisyl, and other anisic compounds. It may be regarded as salicyl,
C*HK)« in which 1 at. hydrogen is replaced by methyl, C^»0« « Cm\CE^)0*: and,
in fact, anisic acid and salicylate of methyl are not only isomeric compounds, but are
both decomposed in the same manner by caustic baryta. Anisic add is, therefore,
to salicylic add, as acetic is to formic add. If, as Firia*s recent researches (Ann.
Ch. Fharm. xciii 262) tend to show, salicylic acid be not monobasic but dibasic, the
clear analogy between it and anisic acia, would probably lead to the conclusion
that the latter add is also dibasic; in which case, all anisic compounds must be
regarded as containing a diatomic radide, CH'O, rather than a monatomic radide.
CTI'O*.

Bboxidb of Awisti^ CJ^'0».Br. (Cahours, Ann. Ch. Fhys. [3] xiv. 488.)
— ^Prepared by dropping dry bromine (excess of which must be avoided), upon hydride
of anisyl : heat is evolved, hydrobromic acid given off, and the mixture soIidMes. The
solid product is rapidly washed with ether, pressed between filter-paper, and dystallised
from ether. ^ It forms white, silky crystals, whi<^ are volatile without deeomposition.
Strong boiling potash gradually converts it into anisate and bromide of potassium.

Chlobidb op Anisyl. C"H'0«.CI (Cahours, Ann. Ch. Fhys. [31 xxiiL 361.)
--When dry anisic acid is treated in a retort with pentachloride of pnoBphoms, a
violent action takes place, and a mixture of products passes into the reodver. These
are fractionally distilled, that part which boils between 260® and 270® C. being eoUeeted
apart, washed with a little water, and rectified over chloride of caldum. Qiloride of
anisyl also seems to bo formed by the action of chlorine on the hydride. It is a
colourless h'quid, with a strong smell : its boiling point is 262° C; its spedfle gravity it
1*261 at 16®.^ When exposed to moist air, it is speedily decomposed into hydrodilonc
and anisic adds. In contact with dry ammonia, it evolves heat^ and is converted into
nnisamide (9. t;.\ Alcohol and wood-spirit attack it energetically, forming hydro*
chloric add, ana anisate of ethyl and methyl respectively.

ANKERl TE— ANNOTTO. 307

Htbbidb of An X STL, C*HK)' B CJbL'O*. H. AnisyhooMeratoff ; Aniaylotts
Aad; Anitie Aldeh/de; AniadL (Gab oar 8. Ann. Ch. Phys. \Z'] sir. 484 ; zxiiL 354.)
— ^Formed, together with anisic aeid, hj the oxidation of oil of anise, or of anisic
alcohol ; in the latter case^ the actioa of platinum-black is sufficient to produce the
effect. It is prepared bj ^ntly heating oil of anise for about in hour, with three
dmes its Tolnme of nitric acid of specific giaTity 1*106 (14^ Baum^) : the heaTj oil
whidi is thus formed is washed with dilute potash, ana distilled. The distillate is
sgitated with a wann solution of add sulphite of sodium, of specific gravity 1'25 ; the
OTstalline compound thus fonned is collected on a funnel, thoroughly washed with
alcohol, diasolYod in as little hot water as possible, and the solution heated with
excess of strong sodic carbonate, when the hydride of anisyl separates out and floats
on the surface. It is then purified by redistillation. The reaction is as follows, oxalic
add being simultaneously formed :

C»H«0 + 0« = C^K)« + C*H«0« + HK)
Oilofanitew HjdridA Oxalic

ofa&Uyl. add.

Hydride of anisyl is a yellowish liquid, with a burning taste, and an aromatic smell
somewhat Hke that of hay : its specific gravity at 20^ C. is 1*09, and its boiling-point
2530 — 26^ C. It is almost insoluble in water, but soluble in all proportions in ^cohol
snd cither. Strong sulphuric add dissolves it, forming a dark-ivd solution, whence it
is rqvacipitated by water. When exposed to the air, it gradually absorbs oxygen, and
IS conTerted into anisic add ; the same change is produced more rapidly by means of
fflridising a^nts, such as platinum-black, or dilute nitric add. Strong nitric acid
conTerts it into nitranisic add. Strong aqueous potash does not dissolve it till after
long boiling; iused or alcoholic potash convert it into anisate, with evolution of hydro-
gen, or formation of anidc alcohol. Prolonged contact with caustic ammonia converts
it into anishydramide (^. v.). Pentachloride of phosphorus attacks it energetically,
the mixture thickenings and finally becoming a black pitchy mass, and a scanty distillate
is obtaioied, consisting of chloride of phosphoryl, together with a neutral oil having a
strong smell of tnipentine.

Hydride of anisyl possesses the property peculiar to aldehydes, of forming crys-
talline compounds with add sulphites of alkali-metal. Sulphite of anisyl'Sodium,
C"H^aO«,SO« + aq. (Bertagnini, Ann. Ch. Pharm. Ixxxv. 268), is obtained by
agitating hydride of anisyl with a strong solution of acid sulphite of sodium : the mix-
ture assumes the consistence of butter, ^nd .finally becomes crystalline. When dried
and reerystaHised horn boiling alcohol, it forms colourless, shining scales ; but it is
always partially decomposed during ciystaUisation. It is soluble- in cold water, and
is repredpit^ed by add sulphite of sodium, in which it is almost insoluble : its aque-
ous solution IS decomposed by boiling, hydride of anisyl being formed and sidphurous
anhydride evolved Adds and alkalis d^ompose it also. . Ammonia dissolves it, form-
ing oily drop which gradually solidify into ciystals of. anishydramide. Iodine and
bromine decompose it readily. The potassium- and ammonium-compounds are similar
to the sodiiim-componnd, both in mode of formation and in general properties. F.T. C.

JkMMMMXTM, A variety of dolomite, CO'CaMg, in which the magnesium is
parity replaced by iron and manganese. According to Berthier (Pogg. Ann. xiv.
laZ), it rases to a crystalline compound with carbonate of sodium.

See KicxsL-oABBN.

rck {Tempering, Sicttit, Aniasaen,) — ^Many bodies when raised to a
hi^ temperature and quickly cooled, become very hard and brittle. This is a great
inconTenience in glass, and also in steel, when this metallic substance is required to
be aatl and flexible. These inconveniences are avoided by cooling the substance very
gndnahj ; and the process is called annealing. Glass vessels, or other articles, are
carried into an oven or apartment near the great Aimace, called the leer, where they
are permitted to cool, more or less quiddy, according to their thickness and
bulk. The annealinff or tempering of steel, or other metallic bodies, consists simply
in heating them, and suffering them to cool again, either upon the hearth of the
furnace^ or in ai^ other situation where the heat is moderate, or at least the tempera^
tore is not veiy low.— U. (See Dictionary of Arts, ManvfactuTU, and Mines, i. 162.)

The pellideB of the seeds of the Bixa oreUana, a liliaceous shrub,
from 16 to 20 feet high in good ground, afibrd the red masses brought into Europe
under the name of annotto, anaito, amattOj amottOy orlean, and roucou.

The annotto commonly met with in this country is moderately hard, of a broirn
colour on the outside and a dull red within. It is difficultly acted upon by water,
and tinges the liquor of a pale brownish-yellow colour. In rectified spirit of wino,
it dissolves very readily, and communicates a high oninge or ycllowish-red colour.

z 2

308

A NORTHITE— ANOXOLUIN.

Hence it is used as an ingredient in TamisheB, for giving more or less of an onnge
cast to the simple yellows.

Ether is the best solrent of annotto. Potash and soda, either caostic or cariwnated,
disolve annotto in large quantity, frpm which solutions it is thrown down by add*
in small flocks. The alkaline solutions are of a deep red colour. Cfalorme de-
colorises the alcoholic solution of annotto, the liquid becoming speedily wMto aod
milky. If strong sulphuric acid be poured on annotto in powder, the red coloor paases
immediately to a reiy fine indigo blue : but this tint is not permanent, changing to
green, and finally to yiolet, in the course of twenty-fomr hours. This property of
becoming blue belongs also to saSron. Nitric acid, slightly heated on annotto,
sets it on fire, and a finely divided charcoal remains, iljmotto is soluble Iwth in
essential oils, as oil of turpentine, and in fixed oils. (Boussingault, Ann. CL Fhy&
zzviii. 440.)

Annotto contains a crystalline yellow colouring matter, called hixin {q.v.), vhich,
when treated with alkalis, in contact with air, absorbs oxygen, and is oonTerted into a
red substance called bixein, Annotto is used in dyeing, but the colours produced by it
are all fugitive ; also for colouring cheese. — ^U. (See ur^s Dictionary of Arttf licaat-
faeiureSf and Mina^ i. 178.)

AXOVMm Faraday's term for the positive pole or electrode in the voltaic dieoit
(See AxiOTX and ELBCTBicnr.)

AiroSTBZTB. Ca«O.SiO« + Al<0».SiO« = (Caa?)SiO*.— A mineral belonging to
the felspar family. It occurs in small crystals belonging to the tridinic system; also
massive, with granular, colunmar, or coarsely lamelliu* stnicture. Cleaves perfectly in
two directions, inclined to one another at 86^48'. Specific gravity 2*66— 278.
Hardness » 6--7. Transparent to translucent, with white, greyish or reddish ooloiir,
and vitreous lustre. Streak uncoloured. Fracture oonchoidaL Brittle. Before the
blowpipe it melts, and forms with soda a milk-white enameL Strong hydroeUorie
acid decomposes it completely, but does not gelatinise it.

Anorthite is found on Vesuvius and Somma, in the island of Procida, in Goisica, near
Bogoslowsk in the Ural, on Hecla and in other localities in Iceland, in Java, in the
island of St Eustache in the Antilles, and in the meteorite of Juvenas. The folloir-
are analyses :

G. Roie.

Deville.

Damour.

Walterihaaten

. FotykL

Soroma.

Antilles.

Heda.

Hada.

Unl.

SiO«

. 44*49 .

. 45*8 . ,

. 46*97 .

. 4614 .

. 46-79

A1*0«

. 34*46 .

. 35*0 . .

. 33*28 .

. 82*11 .

. 8316

Fe<0«

. 0*74 .

, — ,

. 1*12 .

. 2*03 .

. 8-04

Ca»0

. 16-68 .

. 17*7 . .

. 17*21 .

. 18*32 .

• 16-97

Mg«0

. 6-26 .

. 0-9 . ,

— ,

• ^^"

.—

Na«0

— ' .

. 0*8 . ,

1-86 .

. 1*06 .

. 1-28

K«0

• — •

• — .

— ,

. 0-22 .

. 0-55

Ni*0 and Co»0 .

, — ,

• -^ •

-—

. 0-77 .

—

Water

. —

. — .

— .

. 0-31 .

100-63

100-2

99*43

99*96

100-79

The fbrmula above given, which is that of an orthosilicate, requires 43*2 SiO', 86'8
A1«0», 20-0 Ca«0.

The following are varieties of anorthite having nearly the same composition and
crystalline form: —1. Amphodelite has the structure and specific gravity of anorthite;
found at Logi, in Finland^ and Tunaberg in Sweden. — 2. BytovmiU^ from Bytovn in
Canada. — 3. Diploiie or Ixitrobite, from the island Amitok on tiie coast of Labrador.
Rose-red, with the form, structure, and density of anorthite. — 4. Indianiie^ froB
Hindostan. Ghranular masses, having the structure of felspar. — 6, LepoltiU, fromlxigi
and Orgarfvi in Finland. Resembles amphodeUte. — 6. Idndsayite, from the same
localities, appears to be the same altered, and containing a few per cent ofwtter.
— 7. Polyargite^ from Tunaberg. Eose-red; granular; gives oflT water when heated,
and becomes colourless. — 8. RoaeUan, from Aker, Sodermanland. Exhibits similar
properties. — 9. SundvUkit^ from Kimito, Finland. Has the form of felspar ; ud
specific gravity » 2-70. — 10. Wilaomite, from Canada. Eose-red; roedfic gravity
2*76 — 2*77: hardness very different in different parts; becomes oolouriess vben
heated; |;ives ofiT water and melts before the blowpipe, swelling up to aidiite eoameL
(Dana, iju 234;Rammelsberg's Mineralchcmie, 690.)

See AmroTTO.

According to Le con te and Goumoens (Compt rend, zxhl
834), fibrin, muscular fibre, albumin, vitellin, globulin, and casein, contain t«o
different substances, one of which, called oxoluin, dissolves in glacial acetic add, white
the other, anoxolitin, is insoluble in that acidl In fibrin and muscular fibre, Uie

ANTfiOKIRRIN— ANTHRACOXENE. 309

imozoluin maj alao be distingiiished, when ezamined bj the microscope, by its fibrous
B^uetoTC!, from the oxoluin, which is granular. Anoxohiin dissolyes with reddish colour
in dihite sulphuric acid, whereas oxoluin dissolTes but sparingly and with yellowish
colour. Anoxohiin is precipitated of a carmine-red colour by mercuroso-mercuric
nitrate : oxoluin, light rose-red. Chromic acid dissolves anoxoluin at 100^ C, forming a
red-brown 0(dution, whereas oxoluin is not aflhcted by it. Hydrochloric acid dissolves
the former readily, forming a violet solution, the latter but sparingly, with yellowish
eoloar. A boiling saturated solution of tartaric add dissolves anoxoluin readily, but

DOtOXOhlUL

AMVtMOMXMMXM* The yellow colouring matter of the flowers of yellow toad-
flax (Linaria tntlgans or Antirrhinum Linaria^ L). — ^It may be prepared by treating
the flowers with warm alcohol, evi^rating to dryness, exhausting with water to dis-
solve sugar, gam, &c., treating the insoluble porUon with alcohol, evaporating again
and digesting in ether. On evaporating the ethereal solution, the colouring matter is
obtained in yellow nodules. It melts when heated, and sublimes apparently without
decomposition. The fixed alkalis dissolve it with red colour ; ammonia and alkaline
earbonatesi, with dark yellow colour: from, these solutions it is precipitated yellow by
adds. Mmends acids dissolve it with red colour, the solutions becoming yellow on
standing. The concentrated aqueous solution is precipitated reddish-yellow by acetate
of lead, greenish-yellow by cupric-salts, orange-yellow by protochloride of tin. With
hydrate of alumina it forms a pale yellow lake. The flowers of toad-flax are some-
times used for dyeing yellow ; stufib dyed with them have a light yellow colour, but
assume a dirty yellow colour when exposed to the air. (Biegel, Pharm. Centralb.
1S42, 454.)

AnsOKTAV or OTAVZV. The blue colouring matter of flowers. (See
Covofomao Mjlttbb.)

r. The white colouring matter of flowers. (See Oolotjbing

A mineral belonging to the amphibole family. (See

HOSHBLHHDB.)

AWBOfllBJUUTM. A native silicate of iron, found at Antonio Pereira, in
Hinaa Geraes^ BrasiL It haa an ochre-yellow colour inclining to yellow-brown,
and a flbrous radiated structure. Its composition, according to SchnedeTmann's
analysis, is Si*FeK)" + 2H»0 « 2FeH)».9SiO» + 2H«0.

[OXAflTAJJi ■ The yellow colouring matter of flowers. (See Ck^LOXTBiMa

Syn. with Pabanafhthaun.

Blind coalf Kilkenny coal, or Glance coal. — ^There are three
varieties. — I. Massive, the conchoidal of Jameson. Its colour is iron-black, some-
times tarnished on the surface, with a resplendent lustre. Fracture conchoidal, with
a pseado-metallic lustre. It is brittle and light. It yields no flame, and leaves
whitish ashes. It is found in the newest floetz-formations, at Meissner, in Hesse, and
Walsall in Staffordshire. — 2. Slaty anthracite. Colour black, or brownish-black.
Imperfectly slaty in one direction, with a slight metallic lustre. Brittle Spedfic
g^vity 1*4 to 1*8. Consumes without flame. It is composed of 72 carbon, 13 silica,
3-3 alumina, and 3*5 oxide of iron. It is found in both primitive and secondary
rocks : at Calton Hill, Edinburgh ; near Walsall, Staffordshire ; in the sonthem parts
cf Brecknockshire, Carmarthenshire, and Pembrokeshire, whence it is called Welsh
calm ; near Cumnock and Kilmarnock, Ayrshire ; and mostly abundantly at Kilkenny,
Ireland^ — 8. Column4ir anthracite. Small short prismatic concretions, of an iron-
black colour, with a tarnished metallic lustre. It is brittle, soft, and light. It yields
no flame or smoke. It forms a thick bed near Sanquhar in Dumfriesshire ; at Salt-
coats and New Cumnock in Ayrshire. It occurs also at Meissner in Hesse. — ^U. (See
Ur^s IXctumary of Arts, Manufactures, and Mines.)

AM THXACOIATB or'AVTHBACO Jl IT Jit A variety of calc-spar or limestone,
eoloured black or blackish-brown, by coal and bituminous matter, occurring in certain
ahiminoas schists, and similar formations containing vegetable and animal remains,
as at Andreasberg in the Hartz, and at Christiania in Norway. When the bitumen pre-
dominates^ the mineral is called stinksUme, from the property which it possesses of
emitting^ when rubbed or cracked, an odour like that of putrefying animal remains.

AMTtOLAOOMMMMm A fossil resin which occurs in layers of great extent, and
2^ inches thick, between the strata of coal at Brandeisl, near Schlau in Bohemia. It
is brownish-black in the mass, but exhibits a hyacinth-red colour in thin layers ; has

X 3

3 10 ANTHROPIN— ANTIGHLOR.

a Bhining surfaoe, and conchoidal fracture ; is brittle, and yields a yeQowiBli-browD
powder. It melts and swells up strong when heated, and bums with a not nnpleasaiit
odour, leaving a residue of ferric oxide, lime, sulphuric acid, and silica. It appean to
be a mixture of several substances. Ether dissolves a portion of it^ learing a resis,
which has, according to Laurent^ the composition C*.fi**0**. The ethereal Bolvtioa
deposits after partial evaporation, a bviiwn powder, containing (?*H"(Pj and thii,
when exposed to the air, takes up oxygen, and becomes partially soluble in aloofaol;
and the alcoholic solution, precipitated with acetate of copper, yields a ilocealent pre-
cipitate, containing oxide of copper, in combination with a resin, whose oompositioD is
expressed by the formula CH^O^*. The portion left undissolved by the alcohol
appears to contain C^IP*0^. (Handw. d. Chem. 2** Aufl. ii. 39.)

CO ACZB. See Phbnyijcabbamic Acid.

Heintz, in axamining human htt, obtained, besides steaiie add,
an acid which melted at 62° C, and gave by analysis numbers ooiresponding to the
formula C"H"0^ This he at first supposed to be a peculiar acid (anthropie add)
existing in the fat in the form of a glyceride (anthropin) ; but later inyestigatioDi
proved that it was a mixture of stearic acid with margaric or palmitic add. (Fogg.
Ann. Ixxxiv. 238 ; Ixxxvii. 233.)

JkMTlAMXKf C'^H**0* + 2H'0. — ^The poisonous principle of the Upas antiar, a
kind of green resin which exudes from the upas tree (Antiaris toxicarid), and is em-
ployed by the Javanese for poisoning their arrowa It is extracted by exhanstisg
the upas with boiling alcohol, evaporating to dryness after the antiar-resin (see belov)
has cieposited, treating the extract with water, and evaporating to a spip; the
antiarin then takes the form of scales, which are purified by recrystaUisation. It is
without odour, dissolves at 22^*6 C. in 251 parts of water, 70 parts of alcohol, and 2*8
pts. of ether ; the solution is neutral to test-papers. It likewise dissolves in dilate addi.
When dried at ordinary temperatures, it contains 13*4 per cent of water of OTstalli-
sation, which it goes off at 112° C. It melts at 220<> C. into a colourless liquid, which
assumes a vitreous aspect on cooling, and at a higher temperature turn brown, and
exhales acid vapours. Dehydrated antiarin contains C'*H^* (62'69 p.c. C and 7*45
H.) Sulphuric acid colours antiarin brown. Hydrochloric and nitric adds diaaobre
it without alteration ; so likewise do potaah and ammonia.

Antiarin applied to a wound produces vomiting, convulsions, diarrbxBa, and soon
afterwards death ; its poisonous action is remarkablv accelerated by mixture with a
soluble substance, such as sugar. (Mulder, Ann. Oh. Pharm. xxviii 304.)

AVrraS XIBSnr, C^'H'^O. — The upas antiar also contains a resin whidi does
not exhibit any poisonous action. It is extracted bv treating the upas with boiling
alcohol or ether, and is deposited on cooling in wnite, odourless, glutmons flake^
having a density of 1-032 at 20° C, melting at 60°; insoluble in water; soluble in 825
pts. of alcohol at 20°, and in 44 pta. of boiling alcohol Boiling ether dissohres } f^
of the resin. It dissolves readily in essential oils, and is sparingly dissolved by canstie
potash. Its alcholic solution is not precipitated by alcoholic acetate of lead ; bat od
adding water to the mixture, a plastic mass is precipitated containing 23-44 per oeot
oxide of lead. (Pelletier and Caventou, Ann. Ch. Phyg. zxvi 67; Mulder,
Ann. Ch. Pharm. xxvii 307.)

AITTZOB&OB. The application of alkaline hypochlorites (chloride of lime, &c.)
\» the bleaching of cotton and linen, is attended with this inconvenience, that the
fibre is apt to retain a quantity of free chlorine, which gradually rots and destroys it
Hence tlie necessity of removing this free chlorine, either by long continued washing,
or by the application of some reagent which can unit« with the chlorine, and conreit
it into an innocuous compound. Such reagents are called " Antichlors : " their use is
especially necessary in the paper manufacture, in which lone continued washing in-
volvee a considerable waste of the pulp, and on the other hand, the non-removal of the
free chlorine is attended with a gradual rotting of the goods after stowage, fading of
the coloured quantities, and in some instances partial obliteration of docoments
written upon the paper thus imperfectly prepared, besides injury of the delicate
machinery of the manufactory.

The first substances used for this purpose were the neutral and acid sulphites of
sodium (sulphite and bisulphite of soda). A patent for this application of the
acid sulphite was granted in 1847 to Mr. Henry Donkin, a manufacturer of paper-
maker's machinery, &c. at Bermondsey, and it was largely used till 1853, when it was
superseded by hyposulphite of sodium^ which is both cheaper to prepare and more
efficacious, its practical value being just double that of the acid sulphite. (Se«
Hyposulphites, under Sulphub.) The products formed by the action of chlorine, (or
hypochlorous acid) on sulphite or hyposulphite of sodium, are sulphate and chloride of
sodium, both' of which are perfectly innocuous, and easily removed by washing.

ANTICHLOR-ANTIMON Y. 8 1 1

To ensme the oomplete lemoyal of the tree ehlorme, the bleached paper or other
materia], or the VBsh water which nms £nom it^ must be tested with a mixture of
iodide of potaasiiim and starch : the slightest trace of chlorine will be indicated by a
blue eolonr. To ascertain whether an excess of the antichlor has been used, add to the
mixture of starch and iodide of potassium a few drops of the bleaching liquid, so as
to produce a blue colour, and uien add a portion of the liquid to be tested; if
the antichlor is pesent in excess, the colour will be destroyed.

Sulphide of calcium, prepared by boiling sulphur with milk of lime, has also been used
as an antichlor ; so likewise has a solution of protochloride of tin in hydrochloric acid ;
in the latto* case, however, it is neoessaiy, after the completion of the bleaching
proceM, to add carbonate of sodium, in order to neutralise the free hydrochloric acid,
which would otherwise act as injuriously as the free chlorine itself. The precipitate
of oxide of tin thereby produced ia quite white and soft» and does not interfere with
the subsequent stages of the paper manufacture.

* Lastly, eoal-gas has been used since 1818, as an antichlor in paper making ; it does
Bot appear, howerer, to bo so oouTenient as the reagents aboTe-mentioned. (See
BuucHiHO, Ur^s JXetionary of Arts, ManufaetureB, and Mines,)

\ See Ghlo&ikb.

A hydrated silicate of magnesium belonging to the serpentine
grcmp^ found in the yalley of Antigoria in Switzerland. (See Sbbfbntxnb.)

See Amtdcont, Oxidbs of.

eowwwau NatiTe sulphide of copper and antimony, or "Wol^i-
beigite. (See Goffkb, Sulphxdbs or.)

AamasonaA COVPSR CKLAVCS. Also called Wolchiie.—A mineral
found in the ^n mines at St. Gertraud, in Carinthia. Short rhombic prisms with
cleaTBge parallel to the brachydiagonal, imperfect; also massiTe. Specific gravity
6*7 — 5*8. Hardness «■ 3. Colour blackish lead-grey. Fracture conchoidal, to uneven ;
brittle. Contains, according to Schrottez's analysis, 28*60 S, 16*5 Sb, 6'04 As, 29*50
Pb, 17-35 Cu, 0-40 Fe, » 95*94. (Dana, iL 82.)

IWIJLb CBOCnnK. See Aktzkont, Oxtsulfhidb of.

ULB OXB0. See Lead, Sulphidbs of.

COWXA& mCMMih and AMTIMOWIAX, SI&VBB. See Aim-
xoanr. Allots of.

nFXiVBIBB Of MOtVMMm See Sclveb, Suuphidb of.

Native Sulphide of Antimony.

See AxTucoirr, Oxidbs of.

SpiessglantmetaU, BpiessglastmetaU, Antimoiney AntimoniuTn,
Stibium. Symbol, Sb. Atomic weight (as determined by the recent experiments of
Schneider) » 120*3.*

Some of the compounds of antimony were known to the ancients ; but the method of
preparing the metal itself was first described byBasilius YalentinTis towards the end
of tne fifteenth century.

Antimony is fbund native, and alloyed with other metals; viz. with arsenic, nickel,
and sQver ; also in combination with oxygen ; viz. as trioxide, in the form of antimony
bloom, white antimony, or Valentinite, SVO* and as tetroxide, antimony ochre, or
CervanUte, SbH)^; in combination with sulphur, as stibnite or erey antimony ore,
Sb^; with sulphur and oxygen, as red antimony, antimony Mende, or kermesite
Sb'0'.2Sb'S' ; also as sulphide combined with various other metallic sulphides, chiefly
thoee of lead and silver, e.y. sinkenite, Fb*3 . Sb'S'; miargyrite, Ag'S.Sb'S*, &c. (See
8ci.FHA2rTnfONTTBS.) LasUy it occurs in ferrugiuous water, associated with arsenic,
tin, lead, and copper.

Preparation. — All the antimony of commerce is obtained from the native tri-
sulphide, which occurs in many localities among the older rocks, gneiss, clayslate,
porphyry, ^cc. The sulphide is first separated from its gangue by fiision (p. 329), then
eonverted into oxide by roasting, and the oxide is subsequently reduced by coal or char-
coal; or the sulphide is at once reduced to the metallic state by fusion with a mixture
of ehazeoal and alkali, or with metallic iron. The following details are taken from
Gmelin's Handbook, vol. iv. p. 318.

1. Powdered grey sulphide of antimony, mixed with about half its weight of
cfaarooal powder to prevent caking, is roasted at a gentle heat (on the small scale, on a

* BcrseUofl etthnatod tbs Atomic weisht of untimonj at 129, whtch Dumber wm for a long time
adopCfd; H. Bote (J. pr. Qmm. IxtW. lia,3») obtained the number J90*7; Dexter (Pogg. Ann.
c SO) cetifluted it at in-a. (See page S21.)

X 4

■^

312 ANTIMONY.

roastixig dish; on the lai^ scale, in a reTerberatoiy fnrnaee), with oonstant Btimiig,
tie fire being gradnallj increased, bat not sufficiently to fuse the mass. The sn^or
escapes in the form of snlphnrons acid, and there remains a mixture of tetroxide
of antimony vith a small quantity of triozide, amounting to about \ of its imAi
(Qeiger and Beimann, Mag. Phjum. xviL 136), and traces of undeoomposed sulphide
of antimony : Antimony-ask, Calx AnUmonn grisea per te, or Omu AnHmonu. This
residue is then mixed with half its weight of cream of tartar, or with 1 part of ehiN
coal and } pL jntash, or with charcoal powder saturated with an aqueous solution of
carbonate of sodium, and fused in a covered crucible at a low red heat ; the fused nun
is then poured out into a hot mould partly filled with tallow, and .the mould gently
tapped to make the metal sink to the bottom. The slag at the top consists of a mix-
ture of alkaline carbcmate, double sulphide of antimony and potassium (or sodium) and
charcoal. The charcoal separates the oxygen from the antimony, and from a portioa •
of the alkali ; and the potassium or sodium thus eliminated separates the sulphur from
part of the sulphide of antimony still present, and then, in the form of sulphide, miitcs
with the remainder. — 2. A mixture of 8 parts of sulphide of antimony, and 6 parts
of cream of tartar is heated in a crucible, nearly to Kdness, and from 2 to 3 parts of
nitre are added till the mass becomes perfectly fused. Or a mixture of 8 pts. of
sulphide of antimony, 6 pts. of cream of tartar, and 3 pts. of nitre, is projected by
small portions at a time into a red-hot crucible placed in a furnace, and the whole
is heated for a short time, till perfectly fused. The mass is then poured out as before.
The lower stratum consists of metallic antimony ; the upper, of double sulphide of
antimony and potassium mixed with charcoal. The charooal in the black flax with-
draws oxygen from the potash ; the potassium thus separated decomposes a portion of
the sulphide of antimony, setting the metal free; and the resulting sulphide of
potassium nnites with the stOl undeoomposed sulphide of antimony. Probably acoori-
ing to the following equation :

6Sb*S* + 6KK) + 6C - 3(2K«aSb«S») + 4Sb + 6C0.

According to this, only } of the antimony contained in the sulphide should be obtained
in the metallic state, or from 100 parts of the sulphide of antimony, 29*15 parte of
regulus. This result accords with actual experience, 100 parts of sulphide of anti-
mony being found to ^rield 27 parts of antimony. According to Liebig, howerer, by
leaving out the nitre in this process, 100 parts of sulphide of antimony produoe AS
parts of the metaL — 3. An intimate mixture of 8 parts of sulphide of antunony with
1 pt. of dry carbonate of sodium and 1 pt. of charcoal, heated in an earthen cnicible,
and constantly stirred with a stick till it fuses quietly, and then poured out into the
casting mould, yields 6*7 parts (71 per cent.) of antimony, which is afterwards poiified
from iron and copper by fusion with | its weight of nitre (Duf los, Br. Arch, xzxrl
277 ; xxxviii. 168). In this process, rather more than 3 atoms of carbonate of sodinm
and charcoal are used to 1 atom of trisulphide of antimony, so that a suffideot
quantity of sodium is set free to separate the whole of the sulphnr :

Sb«S« + 3Na«0 + 30 = 2Sb -h 3Na*S + 300.

The fusion must be continued for a long time, during which the mass is reiy apt to
boil oyer, and the antimony to burn away; the total amount obtained is only 66 per
cent., and the antimony still contains the whole of the other metals which were
present in the sulphide (Liebig, Id&g. Pharm. xxxv. 120). — 4. A mixture of 177 pta^
(1 at) of sulphiae of antimony with at most 82 pts. (3 at) of iron filings or iron
nails is heated to bright redness in a closely coyered crucible, and then left to oool :

8b»S« + 6Fe - 2Sb+ 3Fe«a

The iron separates the whole of the sulphur, even at a gentle heat ; but a stronger
heat is required to fuse the sulphide of iron, and cause the antimony to form a distinct
stratum beneath it; at this high temperature, the antimony is apt to bum away if the
crucible be not wdl covered ; hence a layer of charcoal powder over the mixtorc is
usefuL — The addition of carbonate of potassium or sodium, or of nitre, accdcrates the
fusion, because double sulphide of iron and Ttotassium or sodium is thereby formed,
which is more readily fusible than pure sulphide of iron. For example, 22 pts. of

carbonate of sodium, and 2 to 6 pts. of charcoal are melted together. Berthier, how-
ever, found it most advantageous to fuse together 100 pts. of sulphide of antimonv,
65 — 60 pts. of smithy scales, 46 pts. of carbonate of potassium, and 10 pts. of charcoal:
this mixture yielded 69 pts. of antimony ; the mass, however, was found to troth ap
considerably. Liebie ^Mag. Pharm. xxxv. 120) gives the preference to this method;
but the regulus which it separata's from sulphide of antimony containing lead is
contaminated with that metal (Ann. Oh. Pharm. xxii. 62). A mixture of 100 pts. of

ANTIMONY. 313

ciilpiiide of antimony, 42 pts. of iron, 10 paits of dry sidphAte of 'sodium, and 2| pts. of
ehaiooAl, yields between 60 and 64 pts. of antimony (Liebig). — The slag obtained
in the seooiid proeen likewise yields, a laige quantity of antimony by fiision with
iron, because tbs doable solphide of antimony and potassium is thereby conyertedinto
donUe solphide of iron and potassiimL

Antimonj obtained by the fi»t| second, and third processes, — the Be^uaAntinumii
timplex a. wdgariB, which solidifies in the mould, and has a stellated stractuze on the
upper sui&ce, wbenoe it has been called Begulut Antimonii stellatust — may contain
sn^phur, potajniom, anenic, lead, iron, and copper; the antimony prqwied by the
fbuith method, Segulua AtUimomi fnartUdu, may contain a large quantity of iron,
especially when the iron has been used in excess. The powdered antimony may be
freed from iron by fosing it with sulphide of antimony ; from sulphur, by fosion with
carbonate of potassium; from sulphur and potassium, by fbsion with nitre; and, ae-
cording to Benelius, from solfAur, potassium, arsenic, and iron, by fusion with from

1 to 1 pi. of antimonious oxide.

Br ioaing sulphide of antimony, or the slag obtained in the second process, with
tin, lead, copper, silver, &c, an antimony is obtained, which may contain small quan-
tities of these metals ; antimony thus prepared was fbnnerly called RegtUua AntimonH
JiymaUM, satumimts, venereua, lunaris, &c

Pitrifieaiion, — 1. By the following method, commercial antimony and likewise that
prepared on the small scale, may be perfectly freed from sulphur, arsenic, iron (when
not in too large quantity), and copper, but not from lead : hence the antimony sub-
jected to this process, should be free from lead. A mixture of 16 pts. of coarsely
poonded antimony with 1 pt. of grey sulphide of antimony and 2 pts. of diy carbonate
of y^inm, is frised in a hessian crocible for an hour, care bein^ taken to prerent any
charcoal from frlling into the mass. "When cold, the crucible is broken, and the slag
completely separated from the metal, which is again coarsely pulyerised, fused with
1^ pt. dry carbonate of sodium for an hour, and, lastly, after cooling and remoTal of the
sla^ once more frsed with 1 pt of carbonate of sodium. In this manner 15 pts. of pure
antimony are obtained (Liebig, Ann. Ch. Pharm. xix. 22). The sulphide of antimony
cooTerts the other metals, excejpt the lead, into metallic solphides, lAuch pass into the
slag in combination with sulphide of sodium. The remaining arsenic is separated by
the carbonate of sodium, in the form of arsenate of sodium. If any charcoiu falls into
the crucible, it reduces arsenic from the arsenate of sodium, whereby the antimony is
again rendered impure (Liebig). Hence a black-lead crucible cannot be used;
each a crudble also reduces sodium, which then mixes with the antimony (Anthon,
KeperL Ux. 240). If the commercial antimony has been prepared with iron, and is
eonsequently ridier in iron, a larger quantity of sulphide of antimony must be added
in the first fbrion, that is to say, in proportion nearl;jr cozxesponding to the iron (4 pts. of
sulphide of antimony and 4 pts. of carbonate of sodium, to 16 parts of the antimony) :
in this case, the lorn of antimony is greater. As long as iron is present, it is impos-
sible to remoTe the arsenic by means of carbonate of sodium (Liebig, Ann. Ch.
Pharm. xxix. 68; Handworterb. 2** Aufl. ii 45; see also Buchner, Bej^rt li 267).
— 2. Well washed powder of algaroth is reduced with alkali and charcoal. By this
means, all impozitiesfrom the heavy metals are ^t rid oL Artus (J. pr. Chim. Tiii.
127) digests 1 pt of finely powdered ^rey sulphide of antimony or glass of antimony,
with 2 pts. of common salt, 3 pts. of oil dT Titriol and 2 pts. of water for eight hours,
then boils for one hour, and afterwards mixes the liquid with water till a permanent
precipitate begins to appear; then filters; precipitates the powder of algaroth by
»AAing more water; washes it thoroughly, and fuses 100 parts of the dry compound
with 80 parts of dry carbonate of sodium and 20 pts. of charcoal-powder for fifteen or
twenty minutes : 61 pts. of pure antimony are thus obtained. — 3. A yery pore metal
may be obtained by heating tartrate of antimony and potassium (tartar-emetic) to
bright redness, and digesting the resulting metallic mass in water, to remoye any
potassium that may have been reduced at the same time. (Capitaine, J. Pharm. xxy.
616; also J. pr. Chem. xriii. 449.)

PuT^eaJtumfrom Arsenic only. — The extensive use of antimonial preparations in
medicine, renders the removal of this impurity a pohit of particular importance. —
1. Four pt& of powdered commercial antimony are mixed with five pts. of nitre and

2 pts. of dry carbonate of sodium (without the latter, insoluble arsenate of antimony
would be formed), and the mixture is projected into a red-hot crucible. The mass
remaining after the combustion (which takes place quietly) is then pressed together,
heated for ha«f an hour to a higher temperature, so that it may become pasty but not
fused, and pressed down as often as it swells up from evolution of gas. After this, it
is taken out of the crucible with the spatula, while still hot and soft, then reduced to
powder, and boiled for some time in water, with frequent stirring. The water, to«

304 ANISIDINE,

aqneons alkalis ; it melts at 99°C., and distils at a higher temperatoie. By long
boiling with water or aqueous alkalis, it is oonverted into anisic add. F. T. 0,

{Methylphenidine, . Gerh.) CTBPNO - N.C'H'O.H'. (Cahouru.
Ann. Ch. Phys. [31 xxrii. 443.]^— The action of sulphide of ammonium on the nitio-
deriyatiTe of anisoi gives rise to the formation of peculiar organic bases. Anisidine is
obtained by dissolving nitranisol in an alcoholic solution of sulphide of ammomnm,
evaporating at a gentle heat to a quarter of its volume, adding a slight excew ojf
hydrochloric acid to the brown residue, separating the sulphur by addition of irater,
and filtering. The yellow-brown filtrate deposits on evaporation, needles of hydro-
chlorate of anisidine, which are dried with filter paper and distilled with a stroog
solution of potash, when anisidine passes over with the aqueous vapour in the form <^
an oil, which solidifies on cooling.

The properties of anisidine but are imperfectly known. It combines with acids, form-
ing salts. The kydrochlorate forms fine colourless needles, soluble in water and alcohol
"^^en a hot concentrated solution of this salt is mixed with a concentrated aolationof
dichloride of platinum, the chhroplatinate separates on cooling in yellow needles. The
nitrate^ mlpnate, and oxalate are ciystallisable.

The products of the action of sulphide of ammonium on the higher nitro-derivBtiTes
of anisoi may be regarded as nitro-derivatives of anisidine, though it is not knovn
whether they can be formed by the action of nitric acid on anisidine.

NiTBANisiDiWH {^Methylmtrophemdine, Gerh.) C'H'ipO* « CrH»(NO*)N0.-
Preparedby aprocesssimilar to that described for anisidine, dinitranisol being substituted
for nitranisol. The filtrate is mixed with ammonia, and the precii>itate thus fSormed
is washed with water, and crystallised from boiling alcohol. Kitranisidine fonns long,
garnet-red, shining needles, which are insoluble in cold, soluble in boiling, water;
soluble in boiling alcohol, whence it separates almost entirely on cooling ; also in
ether, especially if heated. It melts at a gentle heat, and on cooling forms a radiated
mass ; when heated gradually to a higher temperature, it eives ofif yellow fumes, ▼hich
condense i ' " ^' "" .. i •. • i . ^ • • ^-

which has

A'iscous mass, . . ., , ., .

attack it when gently heated, forming hydrochloric acid, and compounds analogons to
benzamide, which are described by Cahours under the names of benzonitranisidey
C"H"NK)< = N.C'HH).(?H«(N02)0.H., c»«7it<ram«ufe, C"H"N«0\ &c These bodies
are obtained pure by successively washing the products of these reactions with vater,
hydrochloric acid, and dilute potash, and crystallising from boiling alcohol; they are
insoluble in water or in cold aJcohoL

Nitranisidine dissolves readily in acids, and with many of them forms crystalline
salts. The hydrochlorate and hydrohromate, when pure, form colourless needles, slightly
soluble in cold, readily in boiling, water. The chloroplatinate separates in orange-
brown needles from a mixture of hot concentrated solution solutions of the hydro-
chlorate and dichloride of platinum. The axdphate forms concentric groups of silky
needles, readily soluble in water, especially in water containing sulphuric acid. The
nitrate forms large needles, much more soluble in hot than in cold water.

Linitr anisidine (Methyl-dinitrophenidine, Gerh.) CH»NK)» = (?H*(N0750.
— ^Prepared precisely like nitranisidine, trinitranisol being substituted for dmitraoisol.
When dry, it is an amorphous powder, of a bright red or violet-red colour, according to
the concentration of the solution from which it was precipitated. It is almost insolnble
in cold water, very slightly in hot water, forming an oranse solution : slightly soluble in
cold, moderately in hot alcohol, and separates on co^ne in violet-black crystals;
slightly soluble m hot ether. It meks at a gentie heat, and solidifies on cooling into a
judiated, violet-black, crystalline mass. It is much less basic in its properties than the
foregoing compound : it forms ciystallisable salts with hydrochlonc, nitric, and sul-
phuric acids, if the acids be employed in excess, but these compounds are decom-
posed by water. When heated with fumins nitric acid, it is violently attacked, and
yields a yellowish brown resinous mass, whi(£ dissolves in potash, forming an intensely
brown solution. F. T. C.

See Amishtdbaicidb.

C"H>"0«. (Limpricht and Ritter, Ann. Ch. Pharm. xcril
364.) — A product of the oxidation of oil of star-anise (probably also of oil of anise, tar-
ragon, fennel, &c.). The oil is heated with nitric acid, of specific gravity 1*2, and the
oily laver which sinks to the bottom of the mixture is agitated with a warm solution
of acia sulphite of sodium, whence anisoate of sodium crystallises on cooling. To the
purified crystals, enough sulphuric acid is added to decompose the salt, the whole era-

ANISOL. 305

pontcd to dzyneBSi and the acid extracted from the residue by absolute alcohoL It
erjrst^Jliaee from its aqueous solution in small laminy, which haye a strong acid reaction,
and are reiy soluble in water, alcohol, and ether; they melt at about 120° C, and are
not -volatile without decomposition.

Aniaoates are mostly readily soluble. The Mdiumsalt, C^'H^'NaO*, and the barium-
MoU^ form white crystalline nodules. The filver-nelt forms soluble nodules, and speedily
blackens when moist. F. T. C.

Stiideler and Wachter (Ann. Oh. Fharm. cxyi. 169) regard this acid as identical
with tkianisoie acid^ C'*H*^SO\the product which they obtain by treating anise-cam-
phor with nitric acid of specific ^yity 1*106, then dutilling and agitating the distil-
late with add sulphite of sodium and alcohol. The atomic weights of the two adds
are neazty equal (anisoic add « 234 ; thianisoic add » 230), so that the determina-
tions of carbon and metal in Limpricht and Kitter^s analyses of the silyer and barium-
salts will agree with the one formula as well as with the other. Moreoyer in Limpricht
and Bitter's analyses of both these salts, the amount of hydrogen found was much too
low for the formula of anisoic add (in the barium-salt 5 '44 per cent, by calculation
5'65 ; in the silyer-salt 4*0 per cent, calculation 4*98), and the absence of sulphur
not established by direct experiment (See Thiaiosoic Acm.)

lOnr. See Anisb, Oil of.

^X. Phenate of mtthyl Draco!. CJ'HK) « C^»(CH«)0. (Cahours, Ann.
Ch. Phys. [3] ii. 274 ; x. 363 ; xxyii. 439.) — This compound is formed by the
action of caustic baryta on anisic add, or on its isomer, salicylate of methyl : also
directly from phenic add, by the substitution of methyl for 1 at hydrogen. It may
be obtained in yarious ways. Anisic add distilled with excess of caustic ba^ta or
lime, 18 decomposed, anisol passing oyer as a yolatile oil : O'HK)' + Ba'O » C^H'O +
CCBa*. The same result follows when salicylate of methyl is dropped on finely
powdered boiyta, and the mixture gently distillecL A third method is to heat phenate
of potaasinm with iodide of methyl in a sealed tube, to 100©— 120° C. C*H*KO +
CWl -» C*H»(CH»)0. + KL The product of either of these reactions is washed with
dilute potash and with water, and rectified oyer chloride of caldum.

Aniaol is a colourless, yeiy mobile liquid, with a pleasant aromatic smell. It is in-
soluble in water, yexy soluble in alcohol and ether, insoluble in potash. Its spedfic
grayity at 15° C. is 0*991 ; it boils at 152° C, and distils undecomposed. It is isomeric
with benzoic alcohol and taurylic acid.

It may be distilled oyer phosphoric anhydride without decomposition. It dissolyes
entirely in strong sulphuric acid, and is not predpitated by water, a copulated acid
beine formed. This add, which Cahours calls siUphanisoliCf and Gerhardt methyl'
suiphopherue add, has the formula CH^O*. By saturating the add liquid with
caroonate of barium, a crystalline barium-salt is obtained, which contains 1 at bariimi.
If filming sulphuric acid be employed, not in excess, the addition of water separates
crystalline flakes of a neutral body, which Cahours calls stU^hanisolide. Its formula
is C'^'^0^ ; it is to sulphanisoHc acid as sulphate of ethyl is to ethyl-sulphuric acid.
This body is best ob^ined by passing the yapour of sulphuric anhydride into arti-
fidally cooled anisol, and adding water to the mixture ; sulphanisolide is then de-
posited in fine needles, which are recrystallised from alcohol, while sulphanisolic acid
remains in solution. It forms soft silyeiy prisms, insoluble in water, soluble in alcohol
and ether. It melts at a gentle heat, and sublimes undecomposed. Strong sulphuric
add conyertB it into sulphanisolic add.

8rBftTiTVTioN-DBBiyATiyBS OP Anisol. — Chlorine and bromine form with
aniaol crystalline substitution-compounds. The chlorine-compounds haye not been
examinea ; there are two bromine-compounds, bromanisol, C'HfBrO, and dibromanisoly
CH'Br^. The latter is soluble in boiling alcohol, whence it crystallises in brillant
scales. It melts at 54° C, and at* a higher temperaturo sublimes entirely in small
shining tables.

Fuming nitric add acts energetically on anisol, forming three distinct nitro-com-
poanda, SitranUol, Dinitranisol, and THnUranisol^ according to the proportions of the
reagents and the duration of the reaction. Nitranisol^ C'H'(N0*)6, is prepared by
adding fuming nitric add by small portions to anisol, the mixture being kept cool by
ice. A bluish-black oil^ liquid is thus obtained, which is washed with dilute potash,
and rectified oyer chloride of caldum. Anisol (Hstils oyer first, and when the boiling
point remains constant at about 260° C, the receiyer is changed. Nitranisol is a clear
amber-coloured liquid, heayier than and insoluble in water, with an aromatic smell,
something like that of bitter-almond oiL It boils between 262° and 264° C. It is
not attacked by aqneous potash, eyen on heating. When gently heated with strong
solphuric add, it dissolyes, and separates out again on the addition of water. When
hofited wi^ filming nitric add, it is successiyely oonyerted into di- and tri-nitranisoL

Vol, L X

306 ANISTL.

Dinitraniaolf C'H*(KO*)*0, is prepared by boiling anisol for a few miniftes vith
excess of fuming nitric acid : on adding water, a yellow liquid is separated, ▼hich
soon solidifies into a yellow mass, which is reaystallised from boiling aloohoL It is
also obtained by heating anisic add to 90° — 100° C, for about half an hoar, with tvo
or three times its weight of fuming nitric acid : chiysanisie acid forms at the same time,
and is removed by dilute potash. Dinitranisol crystallises in long pale yellow needles,
insoluble even in boiling water, soluble in alcohol and ether. It melts at about 86° C,
and sublimes undeoomposed. Aqueous potash does not attack it, even on boiling,
unless the solution be yenr strong, and eyen then long boiling is required: when
boiled with alcoholic potash, it is speedily decomposed, dinitroj^enate of potaanoa
being formed.

Trinitranisol, C'H*(NO*)*0, is formed when anisol, anisic, or nitranisie add is
heated with a mixture of equal parts of strong sulphuric and fdming nitric acii
Anisic add is generally employed for its preparation. The mixture, which at first is
dear and colourless, is gently heated till it begins to become turbid, carbonic anhy-
dride being copiously given off. The heat is then removed, when there gradiuJly
collects on the surface an oil, which solidifies on cooling. A large quantity of water
is then added, and the solid product is washed with boilii^ water, and dystallised from
a mixture of equal parts of alcohol and ether. The reaction is complete if U pts.
of the mixed acids be employed for 1 pt. anisic add. Trinitranisol ciystalliaes in
yellowish, very brilliant tables, insoluble in water, soluble in hot alcohd or in ether.
It melts at 68° — 60° C, and if carefully heated, sublimes. Warm sulphuric or nitric
acid dissolves without decomposing it. Aqueous ammonia or dilute potash, does not
attack it, even on boiling ; but moderately strong aqueous potash gives it an intense
brown-red colour, and oompletdy decomposes it on boiling, forming a slightly solnUe
potassium-salt of an acid, which is isomeric with, but, according to Cahoora, distinet
nom picric, or trinitrophenic add, which he designates picranisic add.

All the nitro-derivatives of anisol are readily attacked by alcoholic sulphide of im-
monium, sulphur being separated, and anisidine and its nitro-derivatiyes being formed.

F.T.a

r* The name given by Brandes and Reimann to a brown product,
obtained by extracting anise-see{ after previous treatment with alcohol, water, and
hydrochloric add, with aqueous potash, and precipitating the alkaline solution bj acetic
acid. F. T. C.

CO AOZn* C**H"NO'. — ^An add analogous to hippnrie acid, prodneed
by the action of chloride of anisyl on the silver-compound of glyoocoll (CH'iigNO' ^
C^WOHJi - Aga + C"H"NO«). Adds, with aid of heat, convert it into glycocoll
and anisic add. (Cahours, Ann. Ch. Pharm. dii. 90.)

AJUBIJk CH'O*. — ^A hypothetical radicle, supposed to be contained in anisic
acid, hydride of anisyl, and other anisic compounds. It may be regarded as salicyl,
CHH}', in which 1 at. hydrogen is replaced by methyl, C'H'O' « Cm\CB^O^: and,
in fact, anisic add and salicylate of methyl are not ozily isomeric compounds, bit are
both decomposed in the same manner by caustic baryta. Anisic acid is, therefore,
to salicylic add, as acetic is to formic add. I^ as Piria*s recent researches (Ann.
Gh. Pharm. xciii. 262) tend to show, salicylic add be not monobasic but dibasic, the
dear analogy between it and anisic acid, would probably lead to the oondnaion
that the latter add is also dibasic ; in which case, all anisic compounds mnst be
regarded as containing a diatomic radide, OH*0, rather than a monatomie radide,

Bromidb of Ahistl. C"H'0'.Br. (Cahours, Ann. Ch. Phys. [3] xiv. 48$,)
— Prepared by dropping dry bromine (excess of which must be avoid^), upon hydride
of anisyl : heat is evolved, hydrobromic add given off, and the mixture solidifies. Th'
solid product is rapidly washed with ether, pressed between filter-paper, and crystallised
from ether. ^ It forms white, silky crystals, which are volatile without decomposition.
Strong boiling potash gradually converts it into anisate and bromide of potassinm.

Chlobidb op Anisyl. C"HW.CL (Cahours, Ann. Ch. Phys. [31 xxiiL 351.)
—-When dry anisic add is treated in a retort with pentachloride of phosphoros, a
violent action takes place, and a mixture of products passes into the receiver. These
are fractionally distilled, that part which boils between 260° and 270° C. bexM collected
apart, washed with a little water, and rectified over chloride of caldum. diloride of
anisyl also seems to be formed by the action of chlorine on the hydride. It is a
colourless liquid, with a strong smell : its boiling point is 262° C; its spedflc gravity it
1*261 at 16°.^ When exposed to moist air, it is speedily decomposed into hydrodiloric
and anisic adds. In contact with dry ammonia, it evolves heat., and is converted into
nnisamide (^. v.V Alcohol and wood-spirit attack it energetically, forming hydro-
chloric add, and anisate of ethyl and methyl respectively.

ANKERI TE— ANNOTTO. 807

Htdbids of AiriSTi^ CH'O' » U"J±'0'. H. Anisylwasaerstoff; Anisyious
Add; Anine Aldehyde; Anisal, (Cahours. Ann. Ch. Phys. [3] zir. 484 ; xxiii. 354.)
— ^FormeGU together with anisic acid, by the oxidation of oil of anisoi or of anisic
alcohol ; in the latter case, the action of platinum-black ia sofficient to produce the
effifict. It is prepared by gently heating oU of anise for about &n hour, with three
cimea its Tolume of nitric acid oi specific gravity 1*106 (14^ Baum^) : the heavy oil
which is thus formed is washed with dilute potash, and distilled. The. distillate is
agitated with a warm solution of acid sulphite of sodium, of specific gravity 1*25 ; the
erystalline compound thus fonned is collected on a funnel, thoroughly washed with
aloc^l, diasolTed in as little hot water as possible, and the solution heated with
excess of strong sodic carbonate, when the hydride of anisyl separates out and floats
on the surface. It is then pozifled by redistillation. The reaction is as follows, oxalic
add being simultaneously fonned :

C»H»«0 + ()• = CmW + C*H«0* + H«0
OilofanifleL Hydride Oulie

ofanUjl. acid.

Hydzide of anisyl is a yellowish liquid, with a burning taste, and an aromatic smell
somewhat like that of hay : its specific gravity at 20^ C. is 1'09, and its boiling-point
263^ — 265° C. It is almost insoluble in water, but soluble in all proportions in ^cohol
and ether. Strong sulphuric acid dissolves it, forming a dark-red solution, whence it
is reprodpitated by water. When exposed to the air, it gradually absorbs oxygen, and
is conrerted into anisic acid ; the same change is produced more rapidly by means of
oridiging agents, such as platinum-black, or dilute nitric acid. Strong nitric acid
eonverts it into nitranisic add. Strong aqueous potash does not dissolve it till after
hmg boiling ; fbsed or alcoholic potash convert it into anisate, with evolution of hydro-
een, or formation of anisic alcohoL Prolonged contact with caustic ammonia converts
it into anishvdramide {q. v.). Pentachloride of phosphoms attacks it energetically,
the mixtuie thiekemng^ and finally becoming a black pitchy mass, and a scanty distillate
is obtained, consisting of chloride of phosphoryl, together with a neutral oil having a
strong smell of turpentine.

Hydride of anisyl possesses the property peculiar to aldehydes, of forming ays-
talline compounds with add sulphites of alkali-metal. Sttlphite of anisylsodium,
C"HTfaO«,SO* + aq. (Bertagnini, Ann. Ch. Pharm. Ixxxy. 268), is obtained by
agitating hydride of anisyl with a strong solution of add sulphite of sodium : the mix-
ture aasomes the consistence of butter, find .finally becoijcies crystalline. When dried
and recrystallised fix>m boiling alcohol, it forms colourless, shining scales ; but it is
always partially deeompoaed during crystallisation. It is soluble* in cold water, and
is repredjit^ted by add sulphite of sodium, in which it is almost insoluble : its aque-
ous sohition IS deoompo8e4 by boiling, hydride of anisyl being formed and sulphurous
anhydride evohed. Adds and alkalis decompose it also. . Ammonia dissolves it, form-
ing oily dro^ which gradually solidify into, crystals of anishydramide. Iodine and
bromine decompose it readily. The potassium- and ammonium-compounds are similar
to the sodium-compound, both in m(Kle of formation and in general properties. F.T. C.

AMMMMTTMb a variety of dolomite^ COHyaMg, in which the magnesium is
partly replaced hj iron and manganese. According to Berthier (Pogg. Ann. xiv.
103), it nises to a crystalline compound with carbonate of sodium.

See NlCKBIrOBBBN.

rCK (Temperinfff Sicuit, Anlaaam.) — ^Many bodies when raised to a
high temperature and quicUy cooled, become very hard and brittle. This is a great
inooDTemence in glass, and also in steel, when this metallic substance is requir^ to
be soft and flexible. These inconveniences are avoided by cooling the substance very
gradnallj ; and the process is called annealing. Glass vessels, or other articles, are
carried into an oven or iq>artment near the great ftimace, called the leer^ where they
ai« permitted to cool, more or less quickly, according to their thickness and
bulk. The annealing or tempering of steel, or other metallic bodies, consists simply
in heating them, and suffering them to cool again, either upon the hearth of the
fiimaoe, or in any other situation where the heat is moderate, or at least the tempera-
ture is not very low.— U. (See JHctionary of Art$, Manufactures^ and MineSf i. 162.)

IkMMVTTOm The pellides of the seeds of the Bixa oreilana, a liliaceous shmb,
from 15 to 20 fiset high m good ground, afibrd the red masses brought into Europe
onder the name of annoitOf anatto, amaito^ arnotto^ orleafiy and roucou.

The annotto commonly met wi^ in this country is moderately hard, of a brown
colour en the outside and a dull red within. It is difficultly acted upon by water,
and tinges the liquor of a pale brownish-yellow colour. In rectified spirit of wine,
it dissolves very readily, and communicates a high orange or yollowish-red colour.

X 2

818 ANTIMONY: DETECTION.

by a gentle heat. - 2. By distilling 3 pts. of antimony with 8 ptB. of mercuric dilmide^
or 2 pte. of the trisulphide of antimony with 4 6 pts. of mercuric chloride :

Sb + 3Hga = SbCl* + 3Hg; and Sb»S^ + 6HgCl - 2SbCl« + 8H^

8. By heating the trisulphide with strong hydrochloric acid, or metallic antimony with
hydiochloric acid to which nitric acid is added in sucoessiye small portions : if too
much nitric acid were added, a precipitate of oxide of antimony or antimonic add
would be formed. A solution of the trichloride in excess of hydrochloric acid is thus
formed, and on subsequently distilling this liquid, water and hydrochloric acid pass
over fint, and afterwards the pure trichloride.

Trichloride of antimony is at ordinary temperatures a translucent fatty mass —
thence called butter of antimony. It melts at 72^ C, and boils at about 200° : iumes
slightly in the air, and is yer^ corrosive. When thrown into water, it is decomposed
into hydrochloric acid and trioxide of antimony, which however remains united with
a portion of the chloride, forming a white powder called powder of algarotk. The
same decomposition takes place on adding water to the solution of the trichloride in
strong hydrochloric add. The predpitate is redissolved by excess of hj^drochloric
acid, and tl^e solution, which contains hydrated trichloride of antimony, is the most
convenient that can be used for exhibiting the reactions of antimony. The addition
of tartaric add to this solution, prevents its decomposition by water.

The anhydrous trichloride combines with annnonia, forming the compound KH'.SbCl',
and forms crystalline compounds with the chlorides of the alkaU-metala.

PBMT1.CHI.0BIDB OF Antimoxt, SbOl', IS formed, with brilliant oombostion,
when finely powdered antimony is thrown into chlorine gas. It may be prepared by
passing dry chlorine over pulverised antimony, gently heated in a tubmated retort
provided with a receiver, or over the trichloride. Hofmann (Chem. Soe. Qu. J. xiil
65) introduces metallic antimony coarsely powdered into a combnsHon*tube five or
six feet long, rising at an angle of 10° or 15°, one end being fitted into a tabnlatun
of a two-nedced glass globe, the other neck of which is connected with a tube sopply-
ing dry chlorine. Combination takes place in the tube, and the products flow back-
wards into the globe, whilst the long layer of antimony prevents the escape of any
chlorine. — ^Pentsu^hloride of antimony is a colourless or yellowifih, very volatde liquid,
which emits sufibcatins vapours. Water first converts it into a oystalline hydrate
and then decomposes it, forming hydrochloric and antimonic acids. It absorbs mii-
monia and phosphoretUd hydrogen^ forming solid red-brown compounds. It absorbs
olcfiant gas^ C^H^ as readily as chlorine, and forms Butch liqmd. By passing diy
olefiant gas and diy chlorine simultaneously through boiling pentachloride of anti-
mony, in a retort connected with an inverted condenser, lurge quantities of I>uteh
liquid may be easily obtained. The pentachloride here acts as a earner of free
chlorine, a purpose for which it may often be advantageously used (Hofmann,
loc, cit. ) It likewise absorbs hydrosulphuric acid gas, at ordinary temperatures, forming
a white ciystalline chlorosulpUde of antimony, Sb01*S, analogous to chlorosulphide of
phosphorus, PC1*S. — ^With oieulphide of carbon, the latter being in excess, it yields
tetrachloride of carbota, trichloride of antimony, and free sulphur :

CS* + 2SbCl» - CCl* + 2Sba« + S».

The mixture becomes very hot, and on cooling deposits crystals of trichloride of anti-
mony, mixed with sulphur-crystals, the tetrachloride of carbon remaining in the
liquid state (Hofmann, loc, eit). The pentachloride combines with hydrocyanic add,
forming a white, crystalline, volatile compound, containing SbC1^3UCy; also with
chlori& of cyanogen. — A white pulverulent substance containing 2SbCl*.88Cl', is ob-
tained by heating pentasulphide of antimony in dry chlorine gas ; it is decomposed at
300° C. into chloride of sulphur, trichloride of antimony, and free dilorine.

[OVT, BBTsonoir Aim mmmtukmou or ■

1. Bloiopipe Reactions, — Solidcompoundsof antimony fused upon charcoal, with
dry carbonate of sodium or cyq^ide of potassium, yield a brittle globule of antimony,
a thick white fume being at the same time given oS, and the charcoal covered to some
distance around with a white deposit of oxide. If the heat be continued for some
time, the globule will be^ completely dissipated. The reduction with cyanide of potas-
sium may be performed in a porcelain crudble without charcoal.

The antimony globule is converted by nitric acid into a white oxide, soluble in a
boiling solution of cream of tartar. It is insoluble in pure hydrodiloric add, but dis-
solves easily on addition of a small quantity of nitric acid, forming a solution of the
trichloride, which is decomposed by water, forming a white predpitate, soluble in
excess of hydrochloric or tartaric acid. If tartaric acid be previously added, water
produces no predpitate.

ANTIMOIfY: DETECTION. 819

2. Liquid Beaetions, — The add solution of the trichloride giTes with hydrosul-
pkuric acid ffot, a brick-red precipitate of the trisulphide, easily aoluble in sulphide of
ammoninm» and reprecipitated by. acids. — ^With potash^ it forms a white precipitate of
the trioxide» soluble in a large excess of the reagent. — ArAmonia forms the same pre-
cipitate, insoluble in excess. Carbonate of potassium or sodium also giyes a white
precipitate of the trioxide, which dissolyes in excess, especially of the potassium-salt,
out reappears after a while. If^ however, the solution contains tartaric acid, the pre-
cipitate formed by potash dissolTes easily in excess of the alkali, — ammonia forms but
a siifl^t precipitate, and only after long standing, — and the precipitates formed by the
alka&ne carbonates are insoluble in excess of those reagents. These last mentioned
diaracteis are also exhibited by a solution of tartar-emetic (tartrate of antimony and
potasainm). The solution of this salt is decomposed b^ the stronger acids, yielding a
white precipitate, consisting of acid tartrate of potassium, mixed with the oxide or a
basic salt oi antimony, mth solutions of barium, strontium, calcium, lead, and aQyer,
it forms white precipitates, consisting of tartar-emetic, the potassium of which is Jite-
plaoed by the other metaL

A solution of trichloride of gold, added to a solution of trichloride of antimony, or
other sntimonious salt, forms a yellow precipitate of metallic gold, antimonic add being
at the same time predpitated in the form of a white powder, unless the solution
contains a larger excess of hydrochloric add :

4Aua« + 3Sb»0« + 6fl«0 = 4Au + 12C1H + 3Sb«0».

The reduction is slow at ordinary temperatures, but is accelerated by heating. In a
flohitioii of tiie trioxide (antimonious add), in potash, trichloride of gold produces a
black piedpitate, which affi>rds a very delicate reaction for antimonious add. Nitrate
of silver produces in a solution of trichloride of antimony, a white precipitate, from
which ammonia dissolves out chloride of silver, leaving oxide of antimony undis-
solved. In a solution of antimonious add in potash, nitrate of silver produces a deep
Uack predpitate, insoluble in ammonia. In a solution of tartar-emetic, nitrate of
■iiver forms a white predpitate, perfectly soluble in ammonia: but if the solution be
pievioiisljr mixed with excess of potash, nitrate of silver produces a black predpitate
inscduble in ammonia.

Zme and iron precifutate antimony from its solutions, in the form of a black powder.
— Copper predpitates it in the form of a brilliant metsUic film, which may be dissolved
off by a solutaon of permanganate of ootassium, yielding a solution which will give the
characteristic red predpitate with hydrosulphuric acid. (Odling, Guy's Hospital
Keports [3] ii 249.)

Antimonic Acid is distinguished from antimonious add by the different colour of
the predpitate which it forms with hydrosulphuric acid (p. 328) ; but better by its
behaviour with chloride of gold and nitrate of silver. Tric%loride of gdd produces no
piedpitate in solutions of antimonic add, not even when they contain excess of potash.
JfitraU of sUeer^ added to a solution of antimonate of potassium, forms a white pred-
pitate of antimonate of silver, perfectly soluble in ammonia : if the solution contains
excess of potadi, the predpitate is brown from admixed oxide of silver, but even then
it is compfetely soluble in ammonia. The slightest trace of antimonious acid present
pcodnces a black predpitate, insoluble in ammonia. If a small quantity of an oxide
cf antimony in the solid state be rubbed up with water to a milky liquid in a porcelain
capsule, then dried, and moistened with ammKyivuhnitrate of silver, a black Bpot will
be produced, if trioxide antimony is present, either in the free state or combined with
antimonic acid : but if only antixnomc add is present, no blackening will take place.
This is a very delicate reaction (Bun sen, Ann. Ch. Pharm. cvi. 1). — ^Antimonic add
may also be distin^ished from the trioxide by its behaviour with hgdriodio add,
The pore trioxide dissolves in hydrochloric add to which iodide of potassium is added,
producing a pale yellow liquid, containing tri-iodide of antimony, without separation
of iodine; but antimonic acid or antimonate of antimony, forms under the same dr-
cnmstances a solution coloured dark brown by free iodine :

Sb«0« + 6HI « 2SbP + 3H*0
and Sb*0» + lOHI « 2SbI» + fiH^O + 41.

If the quantity of antimonic acid is considerable, the liquid gives off violet vapours on
boiling; but even if it does not exceed a few hundredths of a milligramme, the free
iodine in the solution majr be detected by shaking it up with a few drops of bisulphide
of carbon, which then exmbits a violet or amethyst colour when it rises to the surface.
It is of course essential that the hydrochloric acid do not contain free chlorine, and
that the iodide of potassium be f^ from iodate. (Bnnsen.)

320 ANTIMONY: ESTIMATION.

When the presence of antimony is suspected in liquids 43ontaining oonndermbla
quantities of organic matter, as in cases of supposed poisoning hy tartar-emetic or
other antimonial preparations, it is best to destio;^ the organic matter bj ozidatioB
' with hypochlorous acid. K the matter to be examined is solid, it should be eat into
small pieces ; if a large quantity of liquid is present, it must be brought by eraporation
to a convenient bulk. It is then mixed with strong hydrochloric acid, a gentle heat
applied, and chlorate of potassium added by small portions, tiU the liquid aoqnirea a
light yellow colour. It is then heated till the odour of chlorine is no longer poeep-
tiole, and afterwards left to cool and filtered. From the dear liquid thus obtained,
the antimony may be precipitated by hydrosulphuric acid, or by metallic copper, and
the precipitates treatea in the manner already described ; or the liquid may be inteo-
duced into a Marsh's apparatus (see Absenio), with zinc and dilute sulphutie acid,
and the antimony reduced, either in the escape-tube by the heat of a lamp, or on a
porcelain plate hdd in the flame. The metallic deposit tnus obtained may be diBsolTed
Id aqua-regia, and the solution treated with hydrosulphuric add, wmch will pro-
duce the characteristic brick-red predpitate. Mother method of testing the deposit
is to moisten it with nitric add, of specific gravity .1*42, then heat the vessel OTer a
lamp, and blow over the surface so as to cause the acid to evaporate without boiling.
The white deposit then remaining consists chiefly or wholly of trioxide of antimony,
which will produce a deep black spot with ammonio-nitrate of silver. A deposit of
metallic arsenic, treated in the same way, gives with ammonio-nitrate of silver, either
a yellow predpitate of arsenite, or a red-brown predpitate of arsenate of silver, accord-
ing to the degree of oxidation produced by the nilzic add. (B un s en.)

3. Quantitative Estimation, — 1. Antimony may be accurately estimated in the
form of tetroxide or antimonate of antimony, SbO*, that oxide being ndther volatile
nor deoomposible at a red heat The antimony being predpitated fiom solution bj
hydrosulphuric acid, the precipitate is washed and (med, then placed, together with
the filter, in a porcelain basin covered with a fiinnel, and fuming nitric add poured
upon it. A violent action then takes place, the antimony and the greater part of the
sulphur being immediately oxidised: the oxidation of tiie sulphur may be com-
pleted by heatinff the vessel over a water-bath. The resulting white mass, consisting
of antimonic acid mixed with sulphuric add, is converted by ignition into pure anti-
monate of antimony, containing 70'22 per cent, of the metal. The oxidation of the
sulphide of antimony cannot be conveniently effected by nitric add of ordinsir strength
(specific gravity 1 '42), because that liquid boils at a temperature 10^ C. above the melting
point of sulphur, and consequently the sulphur separated at the commencement of the
action collects in melted elobules, which are extromely difiicult to oxidise, and if left
in the mass during the subsequent ignition, would reconvert a portion of the oxide of
antimony into sulphide. Fuming nitric add, on the contrary, ooils below the melting
point of sulphur, and the sulphur separated by its action takes the form of a fine
powder, which is easily oxidised at a gentle heat. If the sulphide of antimony is
mixed with a large quantity of free sulphur ^which is often the case when it has been
dissolved in an aScaune sulphide and repreapitated by an add), it is best to remove
the free sulphur by washing the precipitate with bisulphide of carbon.

The oxidation of the sulphide of antimony may also be effected by igniting it with
mercuric oxide (prepared by precipitating a hot solution of mercuric chloride with
excess of caustic potash). When these substances are heated together in equivalent
proportions, a violent explosion takes place ; but if the sulphide of antimony be mixed
with between thirty and fifty times its weight of mercuric oxide, the oxidation takes
place quietly. The mixture is heated in a porcelain crucible, gently, so long as mer-
curial vapours go off, afterwards moro strongly, and at last very strongly, to expel the
last traces of mercury. Antimonate of antimony then remains in the form of a soft
white powder. As mercuric oxide, even when prepared with the greatest care, always
leaves a small residue when ignited, the amount of this residue must be determined
once for all, and the proportionate amount deducted &om the weight of the antimcmate
of antimony. As, however, this residue never exceeds a few thousandths of the whole,
it is not necessaiy to weigh the oxide of mercury with great exactness. In this pro-
cess, it is necessary, if the sulphide of antimony contains a lai^ excess of free sulphur,
to remove that substance by washing with bisulphide of carbon, befbre proceeding to the
ignition; because free sulphur, even when ignited with a laive excess of mercuric
oxide, produces explosions which might occasion loss. The method just described has
l>een lately introduced by B u n s e n (Ann. Ch. Fharm. cvi. 3). It is qmte exact, provided
due attention be paid to the precautions above indicated.

2. The precipitated sulphide of antimony is collected on a weighed filter, dried in
an oil-bath, at about 120° C, and then weighed. A known portion of it is then dther
decomposed by ignition in an atmosphero of hydrogen, whereby the sulphur is expelled

ANTIMONY: ES'llMATION. 321

in the fbnn of hydrosnlphiiric acid, and metallic antimony remains: or a weighed
partion of the sulphide is oxidised by means of hydrochloric acid and chlorate of potas-
mum, the action being continued till the greater part of the sulphnr is conrerted into
snlpfaiiric add, and the remainder collected at the bottom of the liquid in a melted
fdobole. The liquid is then diluted with water containing tartaric acid, to prevent
tke precipitation of a basic salt of antimony, and decanted ; the globule of snlphnr
washed and weighed, and the quantity of sulphur in solution estimated as sulphate of
barium (see Sujlpuub), the quantity thus found being added to the weight of the
^bule. The proportion of sulphur in the precipitated sulphide of antimony being
SiUB found, the amount of antimony is easily calculated. Antimony cannot be accu-
rately estimated by merely weighing the precipitated sulphide, because the precipitate
ahnost always contains free smphur, and sometimes pentasulphide of antimony in
unknown proportion.

When antimonious and antimonic acids exist tog|ether in solution, the total quantify
of antimony may be estimated by treating one portion of the liquid as above described,
and the quantity existing as antimonious add determined in another portion by means
of trichloride of gold, 4 at of predpitated gold corresponding to 3 at. of antimony
(p. SIS).

Atonde Weight of Animony. — ^Berzelius (Schw. X xxii. 69) determined the
amount of tetrozide produced from a given weight of the metal by oxidation with
nitric add, and thence found, for the atomic weight of antimony, the number 129*03.
Th<e same process has more recently been followed by Dexter (Pogg. Ann, c. 679),
wiio found the smaller number 122*33 : but even this number is generally regaxded as
too high, the error being supposed to arise from incomplete oxidation and the conse-
quent admixture of trioxide with the tetroxide.

The number at present most generally adopted is that determined by Schneider
(Pogg. Ann. xeviiL 293) from the analysis of the native trisulphide by hydrogen. Stib-
nite from Amsberg, which consists of pure trisulphide of antimony mixed with only a
email quantity of quartz (about \ per cent.), was decomposed by ignition in a stream
of hydrogen, and the reduced antimony weighed, the escaping gas being passed into
aqaeoDS ammonia to absorb any sulphide of antimony that volatilised, and this
qnaadty being afterwards predpitated by hydrochloric add, oxidised by fuming nitric
acid, and weighed as tetroxide (its quantity did not exceed 1 or 2 milligrammes).
CcOTections were also made for the quartz in the mineral and for the small amount of
sulphide which remained unreduced and unvolatilised ; for which purpose the residue
in the reduction-tabe was weighed, — then digested in aqua-regia, the residual quartz
again vdghed, the sulphur in the solution determined by precipitation as sulphate of
barium, and the amount of antimony in the residue thence determined (about 0*4 per
oenL^ After making these corrections, the compodtion of the trisulphide (Sb'S') wus
found to be 71*480 Sb + 28*620 S » 100, whence, the atomic wdght of sulphur being
32; that of antimony is :

71 'Aft

This result agrees nearly with former determinations by H. Hose, and also with that
found by Weber (Pogg. Ann. xcviii. 456), from the analysis of trichloride of anti-
mony, viz. 120*7. Dumas, by decomposing trichloride of antimony with a standard
solntion of silver, finds for the atomic weight of antimony the number 122. (Ann. Ch.
Phazm. cxiii. 29.)

ValuatUm of AnUmony Ores, — To estimate the amount of antimony in the native
aolphide^ tiie ore is carefully roasted, and then ftised at a moderate heat with 1 to
3 ptsL of black flux and about 26 per cent, of borax, the whole being covered with a
Isyer of common salt The quantity of metal which can be thus extracted from the
solphide does not exceed 64 to 64 y^i cent, the calculated quantity being 71 '6 per
cent. Or the sulphide is ftised with iron filings (about 42 pts. iron to 100 of sulphide),
together with three times its weight of black flux, and about 26 per cent of borax, the
whole being covered with a thick la^er of common salt This process yields 66 to 68
antimony from 100 pta. of the sulphide.

To estimate the amount of suj^hide of antimony in a sample of the crude ore, the
ore, in pieces of about the size of a walnut, is heated in a hessian crudble perforated at
bottom, and standing on another cmdble placed bdow the grate, and surrounded with
ashes or sand to keep it cool. Care must be taken to avoid applying too much heat

If the gangue is not attacked by hydrochloric acid, the amount of sulphide may be
estimated by boiling a weighed jjortion of the ore with that add and weighing the
residue. (£erl, Huttenkunde, iii 26.)

4. Stparation of Antimony from other metals. -^"From the metals of the
aecond uid third groups (see Analysis, p. 213) antimony is separated by prtn^ipitation
Vol. I y

322 ANTIMONY: FLUORIDE— IODIDE.

witii hydrosolphuric acid ; from those of the first groap* whose sidphides are insofaiJb'.e
in alkaline sulphides, it is separated by precipitating with hydrosulphiiric add and
digesting the precipitate in smphide of ammoninm. The sulphide of antimony then
diflisolves, the other metals remaining undissolyed ; and on mixing the filtiate with
excess of hydrochloric or acetic acid, me sulphide of antimony is reprecipitated. "When
hydrochloric acid is used, care must be taken to keep the liquid dilute and not allow it
to get hotv otherwise some of the antimony may be redissolyed.

When antimony is combined with other metals in the form of an alloy, it may often
be separated by treating the alloy with moderately strong nitric acid, which dusolTcs
the other metals, leaving the antimony in the form of antunonie acid, which may then
be conyerted into antimonate of antimony by ignition. This method, however, is not
rigidly exact, because the nitric acid dissolves a small portion of the antimony ; but it
is near enough for commercial purposes. It is of course not applicable to the aepan-
tion of antimony from tin, gold, or platinum.

The separation of antimony from tin may be effected by immersing in the aolntaon a
piece of pure tin, which precipitates the antimony in the form of a bladk powder. To
render the separation complete, a gentle heat must be applied, and the somtion should
contain an excess of acid. The antimony is collected on a weighed filter, dried at t
gentle heat> and weighed. If the sum of the weights of the two metals in the solotioD
is previously known, the amount of tin is at once determined by difference ; if not^ the
metals must be precipitated together by zinc from a known quantity of the solution, and
the antimony precipitated by tin from another portion. — ^Another method of Bepora-
tion given by L evol (Ann. dh. Phys. [31 xiii. 125) is, to precipitate the two metaJs hj
zinc, and treat theprecipitate with strong nydrochloric acid, without previously decanting
the solution of chloride of zinc The tin then dissolves, while the antimony remains
undissolved, the presence of the chloride of zinc f^iTnininTiiTig its tendency to diseohB
in the acid. The tin may be afterwards precipitated by hydrosulphuric acid, and the
sulphide converted into stannic oxide by treating it with strong nitric add

For the separation of antimony from arsenict gold^ and ploHnuTii, see those metals.
From selenium and telluriuTn^ antimony is separated in the same manner as arsenic {q. v.)

AWTZMOVTf VXiVOBIBS OV. SbF*. — Obtained by dissolving the trioxide in
hydrofluoric acid It forms colourless crystals, which dissolve completely in water
without decomposition.

COVTv OIiASS or. See Antdcont, Oxtsxtlphidb 07.

EOVT« BnSIBa Or« or ASTIMOVZIIB OV

generally called Antimtmetted or AntinumtureUed hydroaen SbH'.-^When an anti-
mony-compound, tartar-emetic for example, is introduced into an apparatus in which
hydrogen is generated by the action of zinc or dilute sulphuric acid, the flame pro-
duced by the combustion of the gas at the orifice of tiie jet, acquires a bluish t^ge
from admixture of antimonide of hydrogen. This compound may be obtained in a
state of greater purity by dissolving an alloy of 2 pts. of ziac and 1 pt. of antimony
in hydrochloric or dilute sulphuric acid It is ahrays, however, more or leas con-
taminated with free hydrogen.

It is a colourless gas, and when free from arsenic, quite inodorous ; insoluble in
water and in alkaline liquids. When it is passed into hot concentrated nitric add, a
white powder is deposited, consisting of antimonic add When passed into a solution
of nitrate of silver or chloride of mercuiy, it forms a bhick preapitate, containing the
whole of the silver or mercuiy. The silver-predpitate has been found to be SbA^,
and is formed hj simple substitution of silver for hydrogen. Hence the antimonide
of hydrogen is inferred to be SbH', analogous to ammonia, and to arsenide and phos-
phide of hydrogen, AsH' and PH'.

When antimonide of hydrogen is nassed through a tube of hard glass and stzmigly
heated by the flame of a lamp, it is decomposed, and a mirror of metallic antimony is
deposited on the tube. If a funnel be held over the flame of the gas, a deposit of
trioxide of antimony is formed on its inner surface. A cold porceUin dish heldio the
middle of the flame, becomes covered with spots of metallic antimony, which are darker
in colour than those formed in a similar manner by arsenic, and are farther dis-
tinguished from the latter by not dissolving in hypochlorite of sodium. The antimony
deposit dissolves easUy in aqua-regia and in permanganate of potassium, and the
solution thus formed exhibits the characteristic reactions of antimony with hydro-
sulphuric add, &C. (p. 819). j j

There are several compounds of antimony with alcohol-radides, analogpqs to
antimonetted hydrogen, viz. sUbtrimethyl, Sb(CH*)*, stibtrUthyl Sb(0*H»)« and stOn
iriamylf Sb(C*H")*.

AJrnMOn. IOBIBS or. SbP.— Prepared like the bromide. It is a dark
red body, decomposed by water, forming an oxyiodide. The su/phiodide, Sb'PS*. is

ANTIMONY: ORES AND OXIDES. 323

obtaiiied as a red sabUmate, by heating an intimate mixture of iodine and the
tnsalphid<« in a retoitb It ia decomposed by water, yielding hydriodic acid and an
ozysiuphide.

See p. 311 ; for the ralnation, p. 821.

Tf OZlSflS OV« Antimony forms with oxygen three definite com*
poonda^ Tix.1 the

Trioxide or Antimonions oxide 8b*0' or 8bO^

Tetroxide or Antimonoeo-antimonic oxide . . . Sb'O* or £1^0*
Pemtoxide or Antimonic oxide SVO* or SbO*

The tetradde is perhaps a componnd of the other two, Sb'0*.Sb^ -t 2St^O*. A
mbaxidg SbH) (?) is also said to be prodneed, as a grey film, when antimony is used as
the poaitire pcde in the electrolysis of water. It appears, however, to be merely a mix-
ture of the metal with the trioxide, for, when treated with hydrochloric acid, it yieldi
aolntioii of the trioxide and a residue of antimony. (Berselins.) .

Tbxoxidb of Antixovt, or Aktimovious Oxidb, Sb^O*, occurs, though
SBxely, as a natural mineral {VaUniinUe, White Antimony, Antimony'bloomt Weiss'
piest^iaiuers\ in shining white ciystals belonging to the trimetric system; specific
mntj 6'666 hardness ; 2-6—3. It occurs in vems of primary roc^ at P^zibram in
Bohemia, at Briunadorf in Saxony, and at Malaczka in Hungary. It is found also
in regular octahedrons^ Tiz. as aenarmontite, a mineral from the Gued Hamimim
miiM^ in thepforinee of Constantine, Algeria : it is therefore dimorphous. This oxide
is fivmed when the metal bums in the air, and may be prepared by heating antimony
in a enable imperfectly dosed with its coyer: it is then deposited on the sides of the
emciUe^ a little above the melted metal, in shining prismatic crystals, known by the
name of Jlowere of antimony, floree antimonu araentei. But the easiest mode of obtain-
ii^ it is^ to heat the trisulpmde with strong hydrochloric acid as long as hydrosulphuric
acid continues to escape, and pour the resulting solution of the trichloride mto a
boiling solution of carbonate of sodium. A crystalline powder is then deposited,
consisting (according to Graham) of the anhydrous trioxide:

2SbCP + 3Na«C0« - SVO« + 6NaCl + 8C0«.

Regnault, however, states (Cours de Ghimie, iiL 289) that the oxide thus obtained is
a hydrate, containing Sb'C.H'O or SbHO*. The trioxide is likewise obtained, though
mixed more or less with antimonic add, by treating metallic antimony with nitric
acid (pc 318),

The artificial as well as the native trioxide of antimony is dimorphous. The
ciyvtals produced by the rapid oxidation of the metal belong to the trimetric or right
priamatic system. Sometimes, however, when the oxide is suDlimed at a comparativdy
low temperature, as when a few ounces of antimony are heated till the metal b^ins
to bom, and then left to cool dowly, the prismatic crystals are mixed with regular
cctaheifaons. According to Hitscherlich (Ann. Ch. Phys. [2] xxxiii. 394) the
trioxide is also deposited in regular octahedrons from a solution in boiling soda. In
each of its forms, it is isomorphous with one of the forms of trioxide of arsenic
(arseaious oxide) : the two bodies are therefore isodimorphous. Antimonious oxide is
white or greyish*white at ordinary temperatures, but turns yellow when heated. It
melta bdow a red heat, and sublimes when raised to a higher temperature in a close
TcaseL When heated in the air, it is partlv converted into antimonic oxide. It is
not decomposed by heat alone, but is reduced to the metallic state when heated with
hydrogen, charcoal, or potassiimi.

Trioxide of antimony dissolves sparingly in foater, more freely in strong hydro-
chloric acid; the latter solution is ^uite clear, provided the oxide is free from
antimonic add, but is rendered turbid by dilution with water. It dissolves when
boiled with a/jveoue tartaric acid, and very easily in a solution of acid tartrate of
potassium (cream of tartar), forming the tartrate oj antimony and potassium, or tartar^
emetic, C*H*KSbO^ (See Tabtjlltes.)

It is quite insoluble in nitric acid of ordinary strength ; but dissolves in cold fuming
nitric aad, forming a solution which deposits pearly scales of a nitrate, N'0*.2Sb*0'
(Peligot). It dissolves also in fuming sutphurio acid, the solution depositing
•himng scales of a suJphate containing SSO'.Sb'^O*. It does not absorb carbonic acid;
indeed no carbonate of antimony is luiown to exist.

Triradde of antimony acts as a feeble add, forming salts called antimonites.
The predpitated trioxide dissolves easily in alkalis, but the resulting compjounds are
very unstable, being decomposed by mere evaporation. The solutions give with nitrate
of silver and excess of ammonia, a black predpitate insoluble in free ammonia. They
rodnce trichloride of gold, predpitating the metaL More stable salts, the anti«

y 2

824

ANHMONY: OXIDES.

monoso-antimonates, are formed by tbe onion of the antimonitee with antfmmintwt
(vid, inf.). The tarioxide ftised with caustic alkalis or their carbonates ia concerted
into antimonic acid, which unites with the alkali. (Fremj.)

Tbtboxidb or Axtixokt, or Antimonoso-antimonic oxide, sometimes
called Antimonious acid^ SbK)\ — This oxide is found natiye, as CervanHU or AnUnumy-
ochre, forming acicular ciystallisations, or massive, or as a crust or powder. It is
yellow, or nearly white, of a greasy, bright or earthy lustre, and specific graTitj
4*084. It is found at Pereta, in Tnscany (Dana, iii. 141). The same oxide is pro-
duced by the action of heat upon antimonic oxide (SbK)*), by roasting the trioxide or
trisulphide, or by treating pmTerised antimony with excess of nitric acid. As thus
prepaied, it is white, infusible, and unalterable by heat; slightly soluble in 'water,
more soluble in hydrochloric acid. It is easily resolved into antimonious and anti-
monic oxides. On boiling it with acid tartrate of potassium (cream of tartar) anti-
monious oxide dissolves, and antimonic oxide is left behind ; and when a solution of the
tetroxide in hydrochloric add is gradually dropped into a large quantity of water, a
precipitate of antimonious oxide is first produced, while antimonic acid remains in
solution. From these and similar reactions, it has beei^ inferred that the tetroxide is a
compound of the trioxide and pentoxide, or an antamonate of antimony (SbK)* -i-
Sb*0* « 2SbH)^). On the other hand, it is sometimes regarded as a distinct oxide,
because it dissolves in alkalis, forming salts (often called onttTnonitea), which maj
be obtained in the solid state. By fusing the tetroxide with hvdrate or caibonate of
potassium, exhausting with cold water, treating the residue with boiling water, and
evaporating to dryness, a yellow, unoystalline, saline mass is obtained, comjpoeed of
K^.Sb*0^, and by mixing the solution of this salt with a small quantity of hydro-
chloric acid, a more acid salt^ K*0.2Sb*0* is precipitated. By treating the same
solution with a large quantity of acid, a precipitate is formed, consisting of the
hydrated tetroxide, H*O.SbK)\ It is, however, more in accordance with the reactions
above-mentioned, to regard these salts as antimonoso-antimonates, that is to say,
as compounds of antimonaUa (containing SbH)*) with antimonites (containing SVO*) ;
thus the salt, KK).Sb«0«, may be regarded as (K*O.Sb«0«) + (K"O.Sb«0*), or KSbCF.
KSbO«.

The antimonoso-antimonates of the eaith-metals and heavy metals are insoluble in
water, and may be obtained by precipitation. Two of them are known as natural
minerals, viz. — 1. Bomeiru, or (so-called) Aniimonite of calcium^ found at St. Maroel,
in Piedmont, in groups of minute square-based octahedrons, of hyacinth-red, or
honey-yellow colour ; specific gravity 4*714 (in powder 4*675), hard enough to scratch
glass. It contains 62*18 per cent, antimony, 15*82 oxygen, 16*29 Ume, 1*31 iron, 1*21
protoxide of manganese, and 2*86 silica. The formula, 3Ca'0.2SbK>^ requires 61*9
per cent.Sb, 22*7 0, and 15*4 Ca (Dana, ii. 410).— 2. AmmioliU, or (so-called) ^»/«:.
Toonite of mercury, occurs, mixed with day and hydrated sesquioxide of iron, in the
quicksilver mines in Chili, and at Silberg, near Olpe in Westphalia. It is a red
powder, containing, according to Domeyko (Ann. Min. [4] vi. 183), 12*5 per cent.
SbK)*, 14*0 Hg*0, 22*3 Fe*0«, 26*5 SiO» and 24*7 water (and loss). ProbaWy only a
mixture. (Dana, ii. 142.)

Pemtoxidb of Antixont, Antixonxo Oxidb or Anhtdridb, Sb*0*
In the hydrated state : Antixokio Acid. — This compound is obtained as a hydrate :
--1. By treating antimony with nitric acid, or with aqua regia containing excess (^
nitric add. — 2. By precipitating a solution of antimonate of potassium with an acid.
— 3. Bv decomposinff pentachloride of antimonv witii water.

The hydrated oxide obtained by either of these methods gives off its water at a
heat below redness, and yields the pentoxide or anhydrous antimonic acid, as a
yellowish powder. The same body is obtained by heating pulverised antimony with
mercuric oxide till the green antimonate of mercury at first produced is decomposed
and all the mercury driven off. It is tasteless, insoluble in water and in adds, and
has a specific gravity of 6*6 (Boullay). At a red heat, it gives off oxygen, and is
converted into the tetroxide. It is diissolved by boiling potash-ley, and when fused
with carbonate of potassium expels carbonic anhydride and forms a salt, fiom whidi
acids separate hydnited antimonic acid.

The hydrated oxides or adds obtained by the three methods above given, are by no
means identical. That obtained by the first and second method is monobasic, and ac-
cording to Berzelius, contains SbH)*.H«OorSbH0%* accordingtoFremy, Sb«0*.6HH),
or SbH*0*, when air>dried at mean temperature ; but the add obtained by the action of
water on pentachloride of phosphorus is dibasic, and contains, according to Fremy ,
Sb*0*.4H*0. The monobasic acid is called Antimonic acid; fhc dibasic acid, Meiamti-
fiumic acid. These adds are further distinguished by the following character. Anti-
monic add is a soft white powder, sparinghr soluble in water, reddens litmus, and is
dissolved, even in the cold, by strong hydrochloric add and by potash-ley. The hydn>-

ANTIMONATES. 325

efalotie solation mixed with a small quantify of water, yields after a while, a precipi-
tate of antimonic acid, bat if diluted with a large quantity of water, it remains dear.
Ammonia does not dissolYe it in the cold. It is conYerted into metantimonic acid by
heating witii a large excess of hydrate of potassium. — ^Metantimonic acid dissolves in
acids more readily than antimonic add, and is dissolved by ammonia, after a while,
even at ordinary temperatures. It likewise dissolves oompletdy in a large quantity
of water, and is preapitated therefrom by adds. It is veiy unstable, and easily
efaangv into antimonic add, even in water.

AsrsmosATSs and METJkimHOKATBS. — Antimonic add forms neutral or normal
Mlta» oontaining MK).SbK)* or MSbO* and add salts containing M*0.2Sb*0', or
SbH>*.2MSbO*. Metantimonic acid, which is dibasic, forms normal salts containing
2M?OJBb^O», orM*Sb*0', and acid salts containing 2M«0.2Sb*0», or M*O.Sb«0», so that
the acid metantimonates are isomeric or polymeric with the neutral antimonates.* An
add metantimonate easily changes into a neutral antimonate. (Fremy, Ann. Ch.
Phys. [3] xii 316, 357; xxii 404),— Heffter (Pogg. Ajm. Ixxxvi 411) analysed a
senee of antimonates, which, calculating from the old atomic wdght of antimony
(119), he supposed to contain 12 at. Sb'(^ to 13 at. of a base M*0 ; but on recalculat-
ing the analyses with the new atomic weight (Sb » 120'8), it is found that they agree
with the general formula MK).Sb20>.

The metantimonates of ammonium, potassium, and sodium, are crystalline; the
antimonates of the same bases are gelatmous and uneiystallisable. The soluble add
metantimonates form a crystalline predpitate with sodium-salts ; the soluble antimo-
nates do not form any such predpitate.

The antimonates and metantimonates of the alkali-metals are the only ones that
are easily soluble in water. All the rest are insoluble or sparingly soluble, and may
be obtained by predpitation.

Antimonate of Aluminium, — On adding the solution of an aluminium-salt to
ezoeas of antimonate of potassium, the whole of the alumina is predpitated in com-
bination with antimonic add, in white flocks, somewhat soluble in excess of the
aluminium-salt.

Antimonate of Ammonium, (NH*)K).Sb«0« + 2H«0, or (NH<)SbO» + H»0, sepa-
rates as a white powder from a solution of antimonic or metantimonic add in warm
aqueoos ammonia. — Neutral metantimonate of ammonium, 2(NH*)*0.Sb'0*, is ob-
tained in solution by treating metantimonic add with eoid aqueous ammonia ; it is
not easily obtained in the soHd state. The solution mixed wilJi a drop or two of
alcohol, deposits a crystalline salt, which is the acid metantim^mate of ammonium,
(KH*)K>.Sb'0* 4- 6H*0. This salt is soluble in water, and the solution predpitates
■odinm-ealta. It is very unstable, being converted, with loss of water, slowly at
ordinaxy tempexatorea, and immediately at the boiling heat» into the insoluble neutral
antimonate^ with which it is isomeric

Antimonate ofAniimon$f,8bHy*,SbH)^, — ^The tetroxide of antimony is sometimes
zcgazded as constituted in this manner (p. 317).

Antimonate of Barium, Ba*O.Sb'0^ or BaSbO', is obtained hj double decom-
position, as a floccnlent predpitate which gradually becomes ciystallme ; it dissolves
oknrly in aqueous chloriae of barium.

Antimonate of Calcium, Ca'O.SbK>*, is a crystalline predpitate, which adheres
dooely to the ddoi of the vessel like carbonate of caldum.

Antimonate of Cobalt, Co*O.Sb'0*. — Beddish' crystalline predpitate, which,
when heated, gives off water, turns violet, and then black ; when heated to redness, it
becomes incandescent, and on cooling appears nearly white. — ^By mixing a solution of
sulphate of cobalt with a hot solution of antimonate of sodium, Heffter {loo. cit.)
obtained a floccnlent rose-coloured predpitate, containing Co'O.Sb'0* + 7H*0, and
the mother-liquor, after standing for some days, deposited six-dded prisms containing
CoK).SbH)» + 12H«0.

Antimonate of Copper, OuK).Sb'0','or CuSbO^ is a greenish crystalline powder,
whidi when heated gives off 19^ per cent water, and turns black. At a red heat, it
^owa like the cobalt-salt, turns white, and is afterwards unattackable by acids or alkalis
in solntion. Chi charcoal before the blowpipe, it is reduced to antimonide of copper.

Antimonate* of Iron. — The ferrous salt is a white powder which becomes yel-
lowish grey when d^, red by ignition, and is sparingly soluble in water. THie ferric
salt ia hg^t yellow.

Antimonate of Lead, Pb^.Sb*0*, or PbSbO*, is obtained as a yellow anhydrous
powder by frisine pentoxide of antimony with oxide of lead, or as a white hydrate by
predpitation; tEe hydrate gives off its water when heated, and turns yellow.

If O cs 8, the fOTvrate of the neutral md add antimonatM are M0.8bO» and MOJiSbO», and of the
iMO.SbO* and SITO.^M)' ntpeetirely,

326 ANTIMONATES.

A basio antimonate of lead, known by the name of Nt^pU» YeUaw^ ia nnich naed in
oil-paintin£. It is obtained of the finest colour by mixing 2 pta. of chemically pmra
nitrate of lead with 1 pt of the pnzeat tartar-emetio and 4 pta. of common salt puri-
fied by repeated crystallisation, exposing the mixture i(X two honxa to a heat ^ut
sufficient to fuse the chloride of sodium, and diasolving out the chloride of sodium
with water; if the temperature has not been allowed to rise too high, the Naples
ydlow is tiien obtained in the form of a fine powder. — The aame pigment is likefwise
obtained, but generally of a less brilliant colour, by fusing equal parts of antimony
and lead with 3 pts. of nitre and 6 pta. of eommon salt.

Another basic antimonate of lead, 3Pb*0.SbK)' •«- 4HK), oocura natiTe at Nerts-
chinsk in Siberia, forming the mineral BleinieriU, It is amorphous, renifbrm, sphe-

dell

roidal; also earthy or incrusting; sometimes with curred lamellar stmetore, _
grayity 3*933 (Karsten); 4*6 — 4*76 (Hermann). Lustre resinous, dull, or earthy.
Colour grey, brownish, or yellowish. Opaque. Streak, greyish or yellowish. It is
perhaps a mechanical mixture *of lead and antimony ochres, and i^mears to result from
the decomposition of other ores of antimony. (Hermann, J. pr. Chem. zzxit. 179.)

Antimonate of Lithium, — Obtained by mixing a concentrated soluti<m of
chloride of lithium with antimonate of potassium, in flocks which soon become ciys-
talline. It dissolyes easily in hot water, and separates in grains on ooolii^ In
dilute solutions, no precipitate is obtained.

Antimonate of Magnesium^ MgK).Sb*0' + 12H*0. — Separates by double
decompoeition from boiling solutions, in colourless shining hard crystals, which are
isomorphous with the corresponding cobalt-salt, giye ofif 8 per coit water at 100^ C,
10 per cent at 200°, and 11 per cent at 300°. (Heffter.)

Antimonate of Manganese, — White, altered by exposure to the air, sparingly
soluble in water, somewliat more soluble in excess, of the manganous salt. At a red
heat, it becomes unattackable by acids, but does not glow.

Mercuric AniimonatCy HgH).Sb*0*, or HgSbO', is obtained by doable decom-
position as an orange-yellow precipitate. There is also an oliye-green mercaric
antimonate obtained by heating to low redness a mixture of 1 pt powdered antimony,
and 6 or 8 pts. mercuric oxide. At a stronger heat, this salt giyes off oxygen and
mercury, and leayes antimonic oxide. It is but little attacked by acids ; but boiling
hydrochloric acid dissolyes a small quantity of it, and ammonia added to the sohition
throws down a light green powder.

Antimonate of Nickel, — Sulphate of nickel mixed with a boilin|; solution of anti-
monate of potassium, immediately forms a light green flocculent precipitate containing
NiK).Sb'0' -h dHK), and the mother-liquor, after a few days, yields crystals of da^er
coloun isomorphous with the magnesium-salt and analogous to it in constitution.

AntimonaUe of Potassium,— The neutral salt, KH).SbH>* + 6HK), is obtained
by fusing 1 pt of antimony with 4 pts. of nitre, digesting the fused mass in t^d
water to remoye nitrate and nitrite of potassium, and boiling the residue for an hour
or two with water. The white insoluble mass of anhydrous antimonate is thereby
transformed into a hydrate containing 5 at water, which is soluble. The solution,
when eyaporatedf leayes this hydrate in the form of a gummy uncrystallisable mass,
which giyes off 2 at of water at 160° C, and the whole at a higher temperature.
Accordmg to Heffter the anhydrous neutral antimonate is partly decomposed by pfo-
longed boiling with water, an acid salt 2K*0.SbK)* remaining undissofyed, and the
liquid filtered therefrom yielding by eyaporation the neutral salt with 7 at water :
K«0.SbK)* + 7H«0.

Add Antimonate of P&tassium is obteined by passing carbonic add gas through a
solution of the neutral antimonate. It is white, crystalline, perfectly insoluble in
water, and is conyerted into the neutral salt when heated with excess of potash. This
salt is the aniimonium dunthoreticum lavatum of the pharmacopoaias. (Fremy.)
According to Heffter, the salt thus obtained is 2K*0.3SbH5« + 10H<0.

Neutral MetanHmonate of Potassium is prepared by Aising antimonic oxide or neutral
antimonate of potassium with a large excess of potash. The fUsed mass dinolya in a
small quantity of water, and the solution eyaporated in yacuo yields crystals of the
neutral metantimonate. This salt dissolyes ^ely and without decomposition in wi

water oontuning excess of potash ; but cold water or alcohol decomposes it into potash
and the acid matantimonate. Hence the aqueous solution of this salt giyes a pre-
dpitete, after a while, with salte of soda. (Fremy.)

Acid Metantimonate of Potassium, K«O.Sb*0* + 7H*0, sometimes called granular
antimonate of potassium, — This salt is used as a test for soda. To obtain it, the
neutral antimonate is first prepared and dissolved in tiie maimer aboye described; the

ANTIMONY: QXTCHLORIDE. 327

0(^tioQ 18 filtered to separate any acid antixnonate that may remain undissolved, then
evaporated to a symp in a sUrer vessel ; and hydrate of potassium is added in lumps to
convert the antimonate into metantimonate. The evaporation is then continued till
the liquid begins to erystaUise, which is ascertained bv taking out a drop now and
then upon a ^laas rod, and the liquid is then left to cool A crystalline mass is thus
obtyned, oonaiating of neutral and acid *metantimonate of potassium ; the alkaline
honor ia then decanted, and the salt dried upon filtering paper or unglazed porcelain
(r renay). This salt may also be prepared by treating tricnloride of antimony with
an eaoceas of potash sufiSdent to rediasolve the precipitate first formed, and adding
permanganate of potassium till the solution acquires a faint rose colour. The liquid,
filtered and evaporated, yields oyatals of the granular metantimonate (Reynoso).
Hi^HV^ is sparingly soluble in cold water, but dissolves readily in water, between
46^ana 60^ C. When boiled with water for a few minutes, or kept in contact with
water for some time, it is converted into the neutral antimonate. It must therefore be
preserved in the solid state, and dissolved just before it is required for use. A small
qnanti'^ of it is then treated with about twice its weight oi cold water, to remove
excess of potash, and convert any neutral metantimonate into the acid salt; the
liquid is decanted ; and the remaining salt is rapidly washed three or four times with
cold water, then Idt in contact with, water for a few minutes, and the liquid is filtered.
On adding to the solution thus obtained a small quantity of any sodium-salt, a crystal-
line precipitate is formed, consisting of acid metantimonate of sodium (vid. inf.),

Antimonate of Sodium is obtained in tabular aggregates of small crystals, when
the wash-water, resulting from washing a defiagrated mixture of antimony and nitre,
is mixed with a sodium-salK This sslt has, according to Fremy, the composition
KaK>jSb'0* + 7BK>. A salt of the same constitution is obtained, according to
Hefiler, in regular octahedrons, by boiling golden sulphide of antimony with caustic
soda, and filtering the aqueous extract It is nearly insoluble in cold water, soluble
in about 350 pts. of boiling water. It gives off 2 at water at 200^ C, 2 at. more at
300^, and the rest at a red heat

Jdd Metantimonate of Sodium, Na«O.SbK)» + 7H«0, or 2NaH0.Sb«0» + 6EP0.—
This salt is produced when a solution of acid metantimonate of potassium, free from excess
of alkali, is added to the solution of a sodium-salt If the solution is not very dilute
the precipitate is fiocculent at first, but soon becomes crystalline. It is produced
immediately in solutions containing not less than 1 pt of sodium-salt in 300 pts. of
liquid. In more dilute solutions, the precipitation is gradual, the metantimonate of
sodinm being deposited in crystals on the sides of this vessel, the effect being apparent
after twelve hours, even in solutions containing not more that j^ pt of sodium-salt.
The precipitation is accelerated and rendered more complete bv aadmg a little alcohol.
The presence at firee alkali retards it. The solution of sodium to he tested in this
manner should he free from salts of lithium, ammonium, and the earth-metals, all of
which, when diluted to a certain extent yield precipitates of similar character. Acid
metantimonate of sodium gives off 6 at of water at lOO^C, the seventh at about 300^.

Antimonate of Strontium. — Amorphous precipitate containing Sr'O.SbH)' +
6BPO.

Antimonate of Zine, Zn^CSbK)*. — Crystalline precipitate somewhat soluble in
excess of the zinc-salt When heated, it gives off water and turns yellow, but without
incandescence. On charcoal before the blowpipe it does not fuse; neither is it
reduced without addition of alkali.

% OX¥ CHLMMTDM OV. Basic Chloride of Antimony, Powder
of AlgoToihy Pulois Algarotki s. angelicus^ Mercurius Vita^ &c. — A compound formed
by the action of wat^ on trichloride of antimony. It was formerly much used in
medical practice, but now serves chiefiy for the preparation 'of pure antimonious
oxide and tartar-emetic The best way of preparing it is to boil commercial sulphide
of antimony in fine powder with strong hydrochloric acid, till the liquid is saturated,
snlphuretted hydrocen esci^ing all the while ; leave the solution to cool ; add to it,
wiui agitation, smiJl portions of water till it begins to show turbidity ; then filter ;
mix the filtrate with five to ten timeff its bulk of water; and ^icash the resulting pre-
cipitate thoroughly with cold water by decantation or on the filter. The addition of
a small quantity of water and filtration before the complete precipitation, is neces-
sary, in order to remove a small quantity of hydrosulphuric acid, which always remains
in Uie add liquid, but is carried down b^ the first portions of oxychloride precipitated, and
thereby removed : if allowed to remam, it would cause the precipitate to turn yellow.
The dried precipitate is a heavy white amorphous powder ; but if left to stand in
the liquid, or if boiled with it, is converted into a mass of small shining oblique rect-
angular prisms. It varies in composition according to the temperature of the water
nsed for the predpitation and washing. According to Duflos and Bucholz, it is

T 4

828 ANTIMONY: OXY^ODIDE— SELENIDE.

2SbCl*.5SbK>* ; according to Johnston, 4Sba*.9SbH)' ; according to Schneider,
2SbOC^Sb*0*; according to Peli^ot, the precipitate formed in the cold Ib Sbd*.
SVO*, or SbO.Cl, (chloride of antimonyl^ and after it has become oTitaUiM hj
heatine, 2SbCl'.5SbK)'. Continued ira^ung with water removes more and more d
the chloride, ultimately leaving nearly pure antimonious oxide ; alkaline-water remons
the whole of the chloride. ^Rie oxychloride is also decomposed by heat, the eUoide
being TolatiliBed and oxide remaining.

Antimonious oxide dissolyee in about 15 times its weight of the boiling triddoridii^
and tiie solution on cooling solidifies into a pearly grey, perfectly oysfaUline Buai,
apparently consisting of Sb'OCl^SSbCl', analogous to the sulphochloride fomed in
Uke manner (p. 338). It is decomposed by absolute alcohol, with separation of powder
of algaroth. (Schneider, Pogg. Ann. cviii. 407.) m0

AMTXMOWTf OXTZOBIBB OV. Antimonious iodide is decomposed by water,
yielding a white precipitate, which appears to be analogous in composition to the
oxychloride. An oxyiodide, 2SbI'.6SbK)', is likewise obtained in gold-ooloared
spangles resembling iodide of lead, by adding iodine to a solution of tartar-emetic, or
by treating the tridiloride of antimony with solution of iodide of potassimn, eraporat-
ing the solution, treating the residue with water, and repeatmff these opentioDi
seyeral times. It is decomposed by heat. Hydrochloric acia dissmves it, with septr
ration of iodine. It is sUgbtly soluble in tartaric acid and cream of tartar. Nitric
add decomposes it, sepa»£ing oxide of antimony. (Preuss, Pharm. Centr. 1839,
p. 811.)

rXMOBT.OXrSir&VBlBBOV. The compound SbK)'.2Sb9oocnnttatiTe
as Bed antimony^ Antimony blende, Kermesame, Boihepieaeglangerz, in needles or tofts
of capillary crystals belonging to the monodinic system : Specific gravity » 4*6 to 4*6.
HazH^iess » 1 to 1'5. It has a cherry-red colour and adamantine lustre, eiTes i
brownish-red streak, and is slightly translucent, appearing scarlet by transmittMl lig^t.
Melts very readily before the blowpipe, sinking into the pores of the charcoal, and
volatilising in dense clouds. Ignited in a current of hydrogen, it yields hydrosnlt^iinc
acid, water, and metallic antimony (H. B o s e, Popg. Ann. iii. 452). It contains 74*6 to
74*7 Sb, 6'29 to 4*7 0, and 20*5 S. Occurs in veins in quartz, accompanying gre^ and
white antimony, at Malaczka near Posing in Hungarv, at Braunsdorf near ^beif;
and at Allemont in Dauphiny. It appears to result m>m alteration of grey antimony
ore. A similar compound, but of an orange-red colour and containing omy 17*9 per
cent, sulphur, sublimes when aqueous vapour is passed over the ignited trisolphide.
(Begnault.)

Various oxysulphides of antimony may be prepared artificially. They were fonneriy
much used in pharmacy for the preparation of tartar-emetic, but are now neariy ohao-
lete. a. Antimonial croetie or saffron {Crocus antimonii, «. metallorum) is a brownish-
yellow substance, prepared by fiising a mixture' of 3 pts. of the trioxide and 1 pt bi-
sulphide of antimony, or an oxide of antimony with the proper proportion of an^ihiir.
A similar compound, mixed however with variable quantities of antimonite of potassinm,
is obtained by treating the trisulphide with caustic alkalis (p. 832). /3. Glasi ofenH-
mony ( VUrum antimonii) is an orjrsulphide prepared by roasting the grey sulphide at a
moderate heat, till it is converted into the tetroxide, and fusing this antimony ask in
an earthen crucible, with about ^ of its weight of sulphur. It is a brilliant sub-
stance, varying in colour from yellowish-red to hyacinth-red, according to the propcr-
tions used. It eives up its oxide to acids, and evolves sulphuretted hydrogen when
treated with hot nydrocmoric acid. 7. A compound of trisulphide of antimony with a
very small portion of oxide, called Regulua antimonH medicinatis or BuHnus onUmoni,
is obtained by ftasing^ pts. of the grey sulphide with 1 pt of pearl-ash, and sepa-
rating the upper stratum (consisting of sulphantimonite of potassium) from the lowv.
It is a black mass, having a brilliant oonchoi'dal fracture, and yielding a daik grey
powder.

According to liebig, mineral kermes prepared by the action of alkaline eaibonatea
on the amorphous trinilphide, is a definite oxysulphide of antimony (see p. 828) ; Int
kermes obtained bv most other modes of preparation, appears to contain the oxide
merely in a state 01 mixture with the sulphide.

[OBTf 8BUDRBB OV* Antimony and selenium unite when heatod
together, to a lead-grey crystalline mass, the combination being attended with rise
of temperature, often amounting to ignition. The same compound is formed by pre-
cipitating a solution of tartar-emetic with seleniuretted hydrogen ; hence its fomnla
is probably Sl>^Se'. Selenide of antimony is easily frisible, and oxidises when heated
in the air, giving off selenious add, Heated with trioxide of antimony, out of oontaet
with the air, it melts into a mass resembling the fused sulphide.

ANTIMONY: SULPHroES. 829

ftOV. Antimony fomu two ni]pliidr«, Sb'S' and
', ooirapopdiiiK to antuaonioDa Bud to autimoDic oxide, and perliapa alio an
mtdiata ralfjiide correapondiog to the tstroiide.

LBTinonT, AnTiMomoDS SoLPHiBa, Ambtdbouh
CIO, Sb%', 0T5t5*.~-TliiBEompoQDdezi>tBintheci7itilliii«

idtiualphide oc«im ua natDnlmiiMnl called Btibnite, itibiae, gr^
■umr, antimoDj-glanee (^Unglanr, Gravnieieplamtre, AnUmoim nd/uri, Lto
', Atmtttm nigrum, XiipNi melaUormH). It i> the sonice of all the antimonj of
aeree. It is foond in Tarioua localiti«B in Hungary, Qermany, and France, abo
in COTnwaH, in Dmn&ipaahire, in lllaine, Manland, acd Nev Hampshire {XJ. S.), and
abifllAittjiD Borneo, — alvaTi anociBted wiUi the older roeka, snch as gnein, quartz,'
daj-alaCe, mica-slate, limestone^ pon>hjry, &c., whence it is Beparated by Btmple
fluKin, yielding the arvde antim/ms of commerce.

The >ep)uabon of the sulphide from the accompanying gangue is efi^t«d ig Tarions
ways. Tin simpleet arrangement is that which is in use at Malbouc in tbe depart-
ment of Ardiche, in France, and at Wolfsbcig in tie Hara. A anmber of ooniad pot»,
perlbrated at bottom, and standing upon receivers sunk in tbe gronnd, are placed
tweoty-fire rar thirty in a ntw, between walls abonC nine inches high, the space be-
tween the pats being filled with coal, and the €re lighted with brushwood. Each pot
holds abont 4fi kilogranunes of ore, and in fbrt^ hours four meltings ore made, Ei^-
EieDt to fill the TOceiTers. The advantage of this method are that it eaTse Uie ei-
peiue of erecting a fiiTnice, and may be carried on at any place to which the ore and
fuel can be most easily transported. But it inTolree a large consumption of fuel, and
is therefore adTautageons only where fuel is Tery abimdant. At Malboec the con-
sumption is 300 kilogrammee of coal and 4D kiL of wood, for evei; 100 kiL of oude
antimony produced.

Aiaothar method, somewhat different &oid {Jie above, consiBtB in heating the oonical
pota bj the fiame of a reverberalory ftimace, the receivers being placed below the
hpartli. This airangement is also in use at WoUsberg, and at La Lincotdn in Haate
Loire. At SchmSltnitz in Hungary, the pots are likewise heated by a reverberatory
funuice ; but tbe mell«d sulphide runs through a channel into receivers placed outside
the furnace. This arranzement effects a considerable saving of time and fUel, ss it
enable* the pats to be filled and emptied without putting out the fire.

In some localiliea, cylindrical tubes are Dsed in preference to conical pots, as being
more dumble. An srrangement of this

kind is in use at Hatboac The ore Fiff. 71.

is placed in large cylinden a a {fig.
IVj each holding 600 pounds of ore,
and four being heated in each flunace.
Tbe i^liDdeni are perforated at bot-
tom, and stand Cn plates piensd with
corresponding apertures. Beneath these
plates, in the chambers o c, are placed
earthen pots F F, to leceive the melted
salohide. The process lasts three horns,
ana wben il i* finished, the leaidues sie
taken oxt, either through the top of
the fnniace, or thiough apertures in the
lower part of the cylinders (which are

lastly, the ore is sometimM heated on
the hearth of a rererbeiatoiy fonaoe, without the use of either pots or cylinden.
Tbe fbmace has an inclined hearth, and the fbsed snlphide flows into a receiver
[daced oolside. This arrangement, which is in use at T^pj, in Frusoia, and at Bomi
in Id Vendue, effects a greatsaving of hel, and likewise does away with the expense
cf tbe cootainii^ Teasels ; but it involves a considerable loss of sulphide of antimony
by l^itiliistinn. and is thereibre adopted only where fuel is very dear.

Whatenr arrangement may be adopted, it is important that Uie ore be not broken
into TOT amaU ^eces. If it be too much divided or pulverised, the melt«d sulphide
emkea tcgotfaermth the gan^oe, and is ven difficult to separate. Too great heat most
alao be avoided, as at B white heat, sulphide of antimony is perfectly volatile. The
^—'*-«B always contun 10 or IS per cent, of antimony, partly m »nlphide, partly h

330 ANTIMONY: TRISULPHIDE.

oxide. [For further details, see Bnmo Kerf^ " Handbach der metanoigiiriicn
Hnttenkunde," Freibeig, 1858, iii. 25.}

Native sulphide of antimony crystaHises in prisms belongiiig to the trimetric system,
with fonr-dddd summits resting on the lateral faces, deava^ yeiy distinct, panllel
to the shorter diagonal and the principal axis. Specifie gravity 4*616 (H&ay); 4-62
(Mohr). Hardness ^ 2. It is sectile, and in thin lanmise slightly flexible; fiactare
snbeonchoidaL It has a metallic lustre and lead-grey colour, inclining to sted-gnj,
sometimes iridescent. Produces a streak of the same colour. The ftued solpliidfi
generally forms blackish-grey, radiating, specular masses, having a steel-giiey lostie.
It is eanly ftisible, thin splinters melting even in the flame of a candle.

The native sulphide is seldom pure, bSng generally contaminated with lead, ooraer,
iron and arsenic Wittstein found in four samples of crude asUimonjf : M|

rf.

Antimony ,

. 62*48

59-67

70*26

71-98

Lead .

. 10-40

11*96

Iron

. 0-70

0-63

0*31

Arsenic

trace

Sulphur

. 26*42

27-74

29*43

28*02

100*00 100*00 100*00 100*00

a. Iridescent, from E^ronach in Upper Franconia; b. Non-iridescent, ftom the same
locality; e. Hungarian; d. English.

The best way of detecting these impurities is to heat the finely pulverised minenl
with strong hydrochloric acid, till it is completely decomposed. Lead, if present in
any considerable quantity, will then separate on cooling, as crystalliaed chlonde; vat«r
added to the solution will throw down oxychloride of antimony, while iron, copper,
arsenic, and a littie lead will remain in solution ; copper may then be detected hj
ammonia, iron bjr ferrocyanide of potassium, lead by sulphuric acid.

To detect arsenic, the pulverised mineild is deflagrated with nitrate and enrbonite
of sodium ; the fiised mass boiled with water, the filtrate acidulated with hydroehlonc
acid, and sulphurous acid added to reduce tJie arsenic acid to arsenious acid, vhieh
may then be precipitated by sulphuretted hydrogen. The precipitate, howerer, may
likewise contain sulphide of antimony, and must therefore be further examined.

To obtain pure crystallised trisulphide of antimony, it is best to prepare it arti-
ficially, by fising pure metallic antimony with sulphur. 13 pts. of finely pnlrerised
antimony are mixed as intimately as possible with 5 pts. of fiowers of sulphur, and the
mixture is thrown by small portions into a heated crucible, care being taken not to
add a fresh portion till the combination of the last portion is conipleted, which m&j
be known by the incandescence which accompanies the action. When the whole has
been added, the crucible is covered and left to cool. If any portion of the antimonj
remains uncombined, it will sink to the bottom of the fdsed mass, and may easily he
separated from the sulphide after cooling. It is sometimes recommended to rnselt
the product two or three times with smaller quantities of sulphur.

The reacHoJu of crystallised sulphide of antimony are the same as those of the
amorphous sulphide, to be presentiy described : but they take place less quickly, on
account of the greater cohesion of the mass.

Amorphoue Trisulphide of Antimony^ Mineral Ker me; — Bnmm^redtdfidik
of Antimony, Pulvis Cartkunanorumt Sulphur siibiatum rubrum, Stibium sulphtrttim
rubrum. — ^This substance is prepared by a great variety of processes, some of which
yield the pure trisulphide, dififering from the native compound only in odloiir and in
the absence of crystalline structure, while others yield the sulphide more or less miied
with the trioxide, and sometimes with other antimonial compounds.

a. The pure amorphous sulphide may be obtained by the following proeesNS.-
1. By keeping the grey trisulphide in the fused state for a considerable time, and Aeo
cooling it very suddenly by throwing the vessel in which it haa been melted into a
large quantity of cold water (Fuchs). — 2. By dissolving the native sulphide in potash-
ley, and precipibiting by an add (Liebig) 3. By igniting 1 pt; otcruJu antimoi^ with

2 pts. of black fiax (a mixture of 1 pt nitre, and 2 pts. cream of tartar), boiling the
ignited mass with water, and mixing the dear filtrate with an alkaline carbonate,
whereby the pure amorphous sulphide is precipitated (Liebig). — 4. By the deeom-
position of alkaline sulphantimonites (livers of antimony). — 6. By treating mineral
kermes containing oxide of antimony, with tartaric add, whereby the oxide u
dissolved out.

b. MineraUKennes containing oxide is obtained by the action of alkalis on the tzi-
Bulphide. The oldest method, given by La Lig^ne, consists in boiling the finely
pulverised grey sulphide with the solution of an alkaline carbonate, and leaving the

ANXmONY: TRISULPHIDE. 381

filtered solution to oool : the same process is giTen in the last edition of the Pmssian
PhannaoopoBia. Ab howeyer, crystallised sulphide of antimony dissolves but slowlj in
yj^«KiM> oazbooate, it is better first to oonvert the czTFtallised into the amoiphous
salphide, andjarepare the kermes firom the latter. The following is the process given
by Lie big THandw. d. Chem. 2«* Aufl. iL 121).

1 pt. of tlie polverised grey sulphide is boiled for an hour with 1 part of solid
eaaatie potash and 30 pts of water (or 1 pt. of the grey suljphide with 4 pts. potash-ley
of q>eeiflc gravity 2*25 and 12 pts. water, or 1 pt sulphide, with 1 pt carbonate of
potaaaium, 1^ pta. slaked lime, and 15 pts. water), and the filtered liquid is mixed
with dilute sulphuric acid, whereby amorphous sulphide of antimony is precipitated.
Hie *K»''^^'*** mixture is then divided into three parts, and covered with water in three
separ^ vessels ; the precipitate is left to settle ; the water is decanted ; and fresh
water added till the precipitates are well washed: they are then placed upon three
separate filters. 1 pt of anhydrous (or 2'7 pts. of aystallised) carbonate of sodium is
next diasolved in 34 pta. of water ; the precipitate from the first of the three filters is
intzodueed into the filtered solution ; the lic^md is boiled for an hour ; and the solution,
which has taken up all the sulphide of antimony, is l^ft to cool, whereupon it deposits
kermes. The supernatant liquid is now brooght to the boiling heat, tne second pre-
cipitate is added to it and treated in the same manner, and finally the same
prooeases are repeated with the third. The finest coloured kermes ib deposited from
the second boiling. The precipitat^es are washed with cold water : their weight after
diying, amounts to nearly the half of the grey sulphide used. [For the rationale of the
pcoeesB, see Dbooicpositioits of Suuphsdi or Aktdcont, p. 833.]

The solution obtained by boDinff the srey sulphide with caustic potash or soda
deposits kermes on cooling, provided the fukali is not in great excess ; and by boiling
the mother-liquors remaining after the deposition of the kermes with the undissolved
portion of the grey sulphide, fr^sh deposits, smaller in quantity, may be obtained.
Acoordiug to Ihiflos, the solution obtamed by boiling 100 pts. of grey sulphide for
a quarter of an hour with a solution of 30 parts of hydrate of potassium in 300 pts.
of water, deposits on cooling 26 pts. of kermes ; a second boiling of the mother-liquor
with the undecomposed grey sulphide yields 10 pts.; a third yields 2*3 pts. llie
snceesaive deposits thus formed are continually richer in oxide of antimony.

A solution containing so much alkali as not to yield any deposit on cooling, yields
a precipitate of kermes when carbonic acid gas is passed through it, and afterwards
an additional ^uantit^ when treated with strong acids. The precipitate thus formed
generally contains a kttle oxide, and always a sulphantimonate of potassium or sodium,
of the form K.^.Sb^*, because, according to H. Kose, part of the antimony is oxidised
by the air, and gives up its sulphur to the trisulphide of antimony, thereby converting
it into pentasolphide.

Kermes may likewise be obtained by boiling sulphide of antimony with potash-lev
and sulphur, or by boiling a solution of sulphantimonite of sodium with metadic anti-
mony. There are also several other modes of preparation, for which we must refer to
Gmelin's Handbook, vol. iv. pp. 340 — 349, where they are frdlv described. The pre-
paratioiia obtained by these different metiiods, are, however, by no means identical ;
they contain variable proportions of oxide of antimony, and many of them likewise
contain solphantimonite of potassium or sodium.

PnpertieB, — The pure amorphous trisulphide obtained by Fuchs's method is a dense
fiasDzed maae^ harder than the native sulphide, having a conchoi'dal fracture, a grey
eolour, or in thin pieces, dark hyacinth-red, and yiel<ung a red-brown powder some-
vhat lighter in colour than ordmaiy kermes; its specific gravity is 4*15. The pure
amori^ioas sulfide prepared by other methods is a brown-red, loosely coherent
powder, which ihakes a brown straak on paper. It is lighter than the native solphide,
and does notconduct electricity. It contams water, wUch it gives off below lOO^' C.
When treated for some time with cold hydrochloric acid, or when fiised and very
alowly cooled, it is converted into the crystalline sulphide.

Ordinaiy kermes containing oxide is a brown-red loose powder, which becomes
blaekiah-gnj when washed witii boiling water. By fusion and slow cooling, it is con-
vexted into a slag-like mass, totally dratitute of crystalline structure^ a property by
vhicfa it dififera essetnially from the pure amorphous sulphide.

HydraUd Trmiiphide of Antimony, — The amorphous sulphide is obtained as a
hydrate W passing salphuretted hydrogen through an add solution of the trichloride,
or throng a solution of tartar-emetic acidulated with acetic acid. The precipitate at
first formed in a solution of the trichloride acidulated with tartaric acid, is a mixture of
the hydrated sulphide with oxychloride ; but on continuing the passage of the gas, it be-
comes darker in colour, and is completely converted into the hydratod sulphide. The
pseeipitate obtained by decomposing a solution of sidphantimonate of potassium with
snlphnrie aeid is probably also the hydrated sulphide.

332 ANTIMONY; TRISULPHIDE.

HjdratAd triBulphide of antimony when diy has a fine dark orange-colour. It giTn off
water when moderately heated, but to dehydrate it completely, requires a tempentan
of 200° C. it then tomfl black. At higher temperatures, it melts and solidifleB in the
ciystalline fozm on cooling.

DecoT/iposiHons of Trisulphide of Antimony. — The reactions of this compomid an
nearly the same, whether it be in the ciystalline or in the amoiphous state, thecxTstalHne
Tarietj merely acting less <}uickly on account of its closer state of aggregation.—
1. The dry amorphous sul|)hide touched with a red-hot body bums away in the air ynik
a glimmering lights producing sulphurous anhydride, antimonious oxide, and antimomc
oxide ; the grey sulphide heated above its melting point, bums with a blue flame,
yielding the same products. — 2. The recently precipitated amorphous sulphide is d^
compo^ bjr boiling for some time with a huge quantity of water, yielaing hydio-
Bulphuric acid and antimonious o^d^ which di^lye. Vapour of water paoed OTer
recUhot sulphide of antimony likewise yields hydrosulphurie add and antimomoiis
oxide, the latter combining with undeoomposed sulphide, and an orange-yellov body
subliming.

3. Chlorine^ with the aid of heat^ decomposes the trisulphide completely, fonning
trichloride of antimony and chloride of sulphur. — i. Heated in hydrochloric add gat
or boiled with the strong aqueous acid, it gives off hydrosulphurie acid, and form
trichloride of antimony, which in the latter case dissolyes m the excess of add.—
5. With strong sulphuric acid, it yields sulphurous anhydride and antimoniona splphate,
the sulphur b^ng separated as a compact mass. — 6. With strong nitrie adi, it fonns
antimonious oxide and sulphuric add, part of the sulphur, however, being set free and
remaining mixed with the oxide. — 7. Agua-regia containing excess of hjdrochlorie
add dissolves the trisulphide, forming trichloride of antimony and sulphnric add,
and leaving a residue of sulphur often mixed with a little antimonic acid. — 8. Tiie
trisulphide ignited with nitrate of potassium or sodium^ is violently oxidised, beiog
completely converted into sulphuric and antimonic acids, if 17 pts. or more of nitze
are used to 10 of antimony ; with less nitre, a compound of sulphide of potaMvm,
sulphide of antimony and antimonic oxide is likewise formed. — 9. Many metala, t. g.
iron^ potassiuTn, and sodium (or a mixture of carbonate of potassium or sodium with
charcoal), decompose sulphide of antimony at a red heat, the resulting metallic solphida
sometimes uniting with undecomposed sulphide of antimony; iC on Sxe other hand, the
reducing metal is in excess, it sometimes forms an alloy with the reduced antimonj.

10. The fixed caustic alkalis decompose trisulphide of antimony in the aam^ manDcr
in the wet and in the dry way, forming trioxide of antimony and a sulphide of the
alkali-metal :

Sb^S" + 3B?0 = 3K»S + Sb«0«,

but the final products of the action vary according to the state of aggregation of the
antimonious sulphide, the temperature to which the mixture is exposed, and the pro-
portions of the two substances present, a. When amorphous sulphide of antimonj,
prepared in the wet way, is triturated with cold potash-ley, it dissolves oompletdg «p
to a certain pointy the sulphide of potassium formed as above, taking up undeoompoan
sulphide of antimony, and the antimonious oxide dissolving in the potash. T^
solution contains sulphantunonite and antimonite of potassium. When treated vith
adds, it yidds a predpitate of antimonious sulphide, without evolution of snlohnietted
hydroffen, because the quantity of tha;t compound evolved by the decomposition of the
sulphide of potassium present^ is but just sumdent to convert the trioxi^ of antimoaj
into trisulphide. But if the addition of the trisulphide be continued, a pdnt is ^
length reached, at which the alkaline liquid cannot take up any more antimonite d
potassium, and anv further quantity of antimonious oxide then formed remains nsdia*
solved, partly combined with potash, partly with antimonious sulphide, forming the
mixture called crocus antimonii (328). The incomplete solution thus formed contaios,
however, a larger proportion of sulphide of potassium than the complete solution, the
excess being proportional to the quantity of oxide left undissolved. This exeeaa of
sulphide of potasdum takes up an additional quantity ^ sulphide of antimony, and
the solution treated with acids, evolves sulphuretted hydrogen, besides giving a pre>
dpitate of antimonious sulphide. The eomjplete solution mixed with carbonate of
ammonium, or with add carbonate of potassium or sodium, yidds a dir^ brown pr^
dpitate consisting of 3 at antimonious sulphide with 1 at. sulphide of potassinm or
sodium, a portion of the alkaline sulphide also remaining in the liquid. The greater
part of the alkaline antimonite is likewise predpitat^ because the canstic aUab
which held it in solution is converted into neutral carbonate. The predpitation of
the antimonious oxide, is, however, partly caused by its affinity for the sulphide
of antimony previously thrown down in combination with the alkaU-metaL The
incomplete solution is decomposed in like mtinner, but the precipitate oontaina a

ANTIMONY: TRISULPHIDE. 833

•mailer propofrtion of antunonic ozida The compete solution rapidly absorbs oxygen
from the air; the sulphide of potassium is first decomposed, yielding oxide of potas-
mm and solphnr, vhich then conyerts the trisnlpnide of antimony into penta-
sii]^hide:

8K« + Sb«S* + 0« « 2K«0 + K«S.SWS*

so that the solution treated with adds yields a precipitate of pentasolphide of anti-
moiiy ; and subsequently the antimonite of potassium is conyerted into antimonate,
vhidi collects in ciystals at the bottom.

6. When antimonioos sulphide in excess is digested with hot caustic alkalUt the
products formed are the same as in the cold, excepting that the sulphide of potassium
then takes up a larger proportion of antimonious sulphide, the excess of which is sub-
sequently deposited on cooling; not, howerer, in the pure state, but in combination,
pertly with alkaline sulphide, partly with antimonious oxide, the composition of the
precipitate being, in fac^ similar to that which is produced by alkaline bicarbonates
in a cold-prepared solution of antimonious sulphide. The supeinatant liquid gives
with alkalme bicarbonates a precipitate of alkaline sulphantimonite free from oxide.

All the precipitates aboTO-mentioned are altered in composition by prolonged treat-
ment with cold water containing air, or with boiling water, antimomous oxide being
dissQlred oat, in combination wiui alkali, and pure dark-coloured antimonious sulphide
remaining.

A, CiTstalline antimonious sulphide is acted upon by caustic alkalis in the same way
as the amcnphous sulphide, but less easily, and when the action takes place in the
cold, a residue of crocus antimotm is always left, whatever may be the quantity of
alkali present The resulting solution exhibits the reactions of the incomplete solution
abore-mentioned.

11. Alkaline carbonates, fiised with antimonious sulphide, either crystalline or
amorphous, give off carbonic anhydride^ and form antimonious oxide and a sulphide of
the alkali-metal, the fiised mass containing these products in combination with excess
of antimonious sulphide and alkaU. With 4 pts. antimonious sulphide and 1 pt.
alkaline carbonate, an easily ftasible mass is formed, which, after cooling, has an iron-
grey colour, is perfectly homogeneous, and is not attacked by water. A mixture of
2 i^ carbonate to 1 pt. antimonious sulphide requires a strong red heat to melt it,
and yields on cooling 12 per cent, of metaUio antimony, together with a light brown
liver of antimony, which deliquesces in the air,, and b perfectly soluble in water. The
separation of the metallic antimony results from decomposition of the alkaline anti-
monite contained in the mass, part of it being converted into antimonate. With
intermediate proportions, the mixture frises more readily, and the resultinfl liver of
antimony is less soluble in water as the proportion of antimonious sulphide is greater.
The insoluble residue contains the excess of antimonions sulphide in combination with
a portion of the alkaline sulphide and with antimonious oxide ; it is, in fact, similar in
eomposition to the erocus prepared in the wet way, but geuerally contains more sulphide
of antimony. Wat«r acts upon these livers of antimony exactly in the same manner
as solutions of Uie caustic alkalis act upon antimonious sulphide under the same

Solutions €(f alkaline carbonates do not act on antimonious sulphide in the cold, but
at the boiling heat» they dissolve the amorphous sulphide rcAdily, the cnrstalline
slowly. The hot solution, prepaled out of contact with the air, contains the same
products as the complete solution of the amorphous sulphide in cold potash-ley (p. 332).
It becomes turbid on cooling, and deposits a grey-brown precipitate similar in compo-
sition to that which is produced by alkaline bicarbonates in the cold complete solution
Just mentioned, consistmg, in fact, of two compounds, viz. an alkaline sulphantimonite
and an oxysulphide of antimony. The H^uid, after tiie separation of this precipitate,
retains a certam portion of alkaline sulphide.

If the solution of antimonious sulphide in hot alkaline carbonate be boiled for some
time in contact with the air, part of the alkaline sulphide becomes oxidised, and gives
up part of its sulphur to the dissolved trisulphide of antimony, thereby converting it
into pentasnlphide, which r^ains in solution after cooling. The quantity of anti-
monious oxide in the precipitate remains the same, but the proportion of antimonious
sulphide in it is diminished by the quantity thus retained in solution. The proportion
of sulphide of sodium is likewise diminished by the oxidation. The quantity of
antimanioas oxide in the precipitate is now not only sufficient to replace aU the
alkaline sulphide in combination with the precipitated antimonious sulphide, but a
certain quantity of alkaline antimonite likewise remains free in the liquid; and there
is precipitated a compound of trioxide and trisulphide of antimony, which is the true
m e dici nal kermes ; it is generally, however, mixed with small quantities of alkaline
aotiioonite.

334 ANTIMONY: SULPHANTIMONITES.

Kermes prepared is thui manner, oontainfl, under all drcomstanoes, a tolerably
ooDBtant qoaniitj of antimonious oxide, becanae, when alkaline carbonates ai« jmei,
the portion of anlphide of antimony attacked by them paases completely into the solntioii,
without leaving any residoe, and consequently the entire quantity of the prodncts thns
formed ia likewise contained in the liquid. (Xiebig, Handwort d. Chem. 2**. Anfl. ii
126—180.)

12. By Ignition with baryta^ Hroniia, limSf and other oxide$^ antimonious sulphide ii
decomposed in the same manner as by caustic and carbonated alkalis : the products
are insoluble in water, and consist of mixtures of metallic snlphantimonites with an
oxysulphide of antimony.

SuifHAimiioNXTXs. — Trisnlphide of antimony is a sulphur-add, uniting with basie
metallic sulphides. Some of tnese compounds, containing the sulphides of the heaty
metals, are natural minerals, viz. :

Zinkenite Fb<3 . Sb>S*

Miargyrite ....... Ag*8 . Sb«S"

Antimonial Gopper^lanoe .... Cu^S . Sb^

Plagionite 4Pb«8 . SSb«8«

Jamesonite 3Pb^ . 2Sb9

Feather-ore 2Pb*S . 8b^

Bouhmgerite 3Pb*S . Sb^

S«

P^TMgyrite 8Ag>8. °5|

Boumonite .... 8(0u*S.Sb^ + 8PM8.2Sb^)

^•"-o- KfJ)-^^)

Stephanite 6Ag^ . 8b^

^0^7^- 9(^) * ^)

Berthierite 3Fe« . 2SWS»

Variety of Berthierite, ftomAnglar . . Fe^ . Sb9
Yariely of Berthierite, fiom Marturet . . 3Fe*S . 4Sb*S'

In these formulae, the elements whose symbols are written one aboTC the other,
replace one another isomorphously. [For description, see the names of the seTeral
minerals.]

The most important of the artifically prepared snlphantimonites are those which
contain the protosulphides of the alkali-metals : they are called LiyersofAntimony
(Ht^r Anthnonit). They are obtained, mixed wiUi oxide in Tarious proportions, br
fusing the trisnlphide of antimony with alkaline carbonates, or metallic antimony with
sulphate of potassium ; and free from oxide, by melting sulphide of antimony with
alkaline sulphates and charcoal, or with alkaline carbonates, sulphur and charonl, or
again by melting sulphantimonate of sodium with metallic antimony.

These alkaline snlphantimonites, or livers of antimony, are easily fbsible, and deli-
quescent or unalterable in the air, according to the proportion of the alkaline sulphide
and the antimonious sulphide contained in them. They are more or less soluble in
water, when the ratio of the antimonious sulphide to the alkaline sulphide is lees
than 2:1; insoluble, when it is greater.

In the fused state, they are black or black-brown and czystalline. Their solutions
boiled with pulverised antimonious sulphides, dissolve an additional quantity of it,
which on coming is deposited as a flocculent precipitate containing also the. alkaline
sulphide. Acids added to the solutions throw down the amorphous sulphide; so like-
wise does carbonate of ammonium. Alkaline bicarbonates immediately throw dovn
sulphantimonite of potassium or sodium; the solution mixed with an alkaline mono-
caroonate, remains clear at first, but solidifies after a while to a tremulous jelly con-
taining the same compound. The same effect is produced when the aqueous solution
of a liver of antimony is diluted with a large quantity of cold water. The solution of
a liver of antimony dianges veiy quickly when exposed to the air, a sulphantimonate
being formed in solution, and a portion of the trisnlphide of antimony being separated
in brown metallic films or as a powder.

PBNTA.8ULPHIIUI OF AnTIMONT; ArTIICONTC SulFHIDB ; AnHTDROUS Sl7I.FIIA!C-

TXMONio Aoro. — Permtlphide of Antimony; Golden StUphuret of Antimony; Sulpktir
AntimonH auratum, Sb'S^ or 8b8^. — This compound is not found native. It is pre-
pared : 1. By nassing sulphuretted hydrogen through a mixture of the pentachloride
with water ana tartaric acid, or through antimonic oxide suspended in water. — 2. By
decomposing the solution of the sulphantimonate of an alkaU-metal with an add, the
sodium-sidt» for example, whereby the sulphide of sodium is decomposed, a salt

ANTIMONY: SULPHANTIMONATES. 335

flf tlw alkili metal being formed, with eTolution of sulplmretted hydrogen, and penta-
sa]{ihid0 k prodpitated :

8Na«S.Sb«S» + 6Ha - 6NaCl + 3H«S + Sb«S».
Sulphantimooaite
oTaodiam.

[For details see Gmelin's Handbook, iy. 366 ; Handworterb. d. Cbera. 2^ Anfl. ii.
133.]

PeDtaflulphide of antimony is a jellowiBb-red powder, or loosely agglomerated mass,
vithont any trace of ciystaJline stmctore ; it nas a yery feeble odour of sulpbur, a
sveetish solplmronB taste, and is slightly emetic. Heated in close yessels to the boil-
ing point of sulphur, it is resolyed into the trisulphide and free sulphur. It bums
with flsme when heated in the air. Exposed to the air in the moist state, it is partly
CQDTerted, after a while, into the triozide of antimony. — Hot hydrochloric add decom-
poses % giving off sulphuretted hydrogen, separatpig sulphur, and forming an aqueous
Bohtum of trichloride of antimony; cold hydrochloric acid imparts to it a greyish
cobv, perhaps in consequence of the formation of the trisulphide and liberation of
2 at SQlphur. — ^Triturated, out of contact of air, with aqueous ammonia^ it dissolyes
eompletdy, more easihr in a warm aeid than in a cold solution, and is precipitated
therefrom by acidsw If the pentasulphide contains trisulphide, the latter remains as
a brown rendue ; a yellow or white residue, on the other hand, indicates the presence
of sulphur or of antimonic oxide. — ^The pentasulphide dissolyes readily in potash or
toda-ley, also in ttdfhide of ammonium. With a solution of sulphate of copper or
nitrate ot silver, it fonns solphantimonate of copper or silyer, togetner with, antunonic
oxide.

ScLPEiBTiMONATBS. — Pentasolphide of antimony is a strong sulphur-acid, uniting
readily with the more basic metallic sulphides, and forming sulphur-salts, most of
which haye the composition 3M*8.Sb*S*, or WSbS* [or 9M8.8bl^, if 8 ^ 16], analo-
goos to that of the ordinary tribasic phosphates (M'PO*). The sulphantimonates of
the alkali-metals and alkaline earth-metals, are yeiy soluble in wat^, and crystallise
for the most part with seyeral atoms of water ; none of them appear to be soluble in
alcohol The sulphantimonates of the heavy metals are insoluble in water.

The sohible sulphantimonates are obtained : — 1. By ftising pentasulphide of antimony
or a mixture of uie trisulphide and sulphur, with the sulphide of an alkali-metal, or
with cfaarroal and the cartwnate or sulphate of an alkali-metaL If a strong heat is
used, the addition of sulphur to the trisulphide is unnecessary, as at high temperatures
that compound is resolyed into metallic antimony and the pentasulphide.— 2. By dis-
BolTing pentasulphide of antimony in aqueous solutions of the alkaline hydrosulphates.
— 3. By dtBsolTing the pentasulphide in the solution of a caustic alkali, or of an alkaline
carbonate at the boiling heat ; in which process an antimonate of the alkali-metal
is formed simultaneously, and deposited as a white powder. — 4. By decomposing the
aqueous solutions of the alkaline antimonates with hydrosulphuric acid, } of the anti-
mony being thereby separated as pentasulphide, because the alkaline antimonates are
monobasic^ and the sulphantimonates tribasic :

8(K«0.Sb»0«) + 18H«S - 8K?S.Sb«S» + 18H«0 + 2Sb«S»
or: 3KSbO* + 9H«S = K*ShS* + 9H«0 + Sb«S».

The insoluble sulphantimonates are prepared by gradually addins a solution of a
metallic salt to a solution of the sulphantimonate of an alkali-meta^ that of sodium
being generally used, keeping the latter in excess. If, on the other hand, the solution
of the other salt is in excess, and especially if the liquid be boiled, the resulting pre-
cipitate contains oin'gen, and the liquid is found to contain free addl The precipitates
thus formed g;eneraUy contain 3M^.Sb^ + 6W0, or rather 8M*S + Sb'O*, being, in
&ct, mere mixtures of a metallic sulphide with antimonic oxide, the latter being
retained in them by its insolubUily. ^Bammelsberg. Pogg. Ann. Ui. 193.)

The soluble sulphantimonates are aecomposed by aU acids, eyen by carbonic acid,
with evolution of sulphuretted hydrogen. Many of the insoluble salts are decomposed
only by nitric acid and a<iua-regia. The sulphantimonates of the alkali-metals are not
deonnposed by ignition in closed yessels ; those of the heavy metals give off sulphur
at a red heat, leaying sulphantimonites containing 3M*S.Sb*§*, or M'SbS*.

Sulphantimonate of Ammonium, Z(KR*y8£h^*, or (NH*)«SbS*, is produced
by digesting pentasulphide of antimony in excess with pure sulphide of ammonium,
&ee fiN>m excess of ammonia. It cannot be obtained in the solid state, being decom-
posed both by concentration, even out of contact with the air, and by mixture with
alcohol

Sulphantimonate of Barium, Ba'SbS* + 3HH).-> Obtained by dissolving re-

836 ANTIMONY: SULPHANTIMONATES.

centlj pfecipitated piosulphide of antimony in Bnlphide of barium, and mmTtg ^
solution witn alcohol, in stellate needles, which, when exposed to the air, do not
deliquesce, but become corered with a brown kermes-ooloural film.

Sulphantimonate of Bismuth is obtained bj precipitation, bat is not euilj
obtained free from excess either of pentasulphide of antimony or of sulphide of bismnth.

Sulphantimonate of Cadmium. — ^Light orange-coloured precipitate obtained by
dropping a neutral cadmium-salt into a solution of sulphantimonate of sodinm.

Sulphantimonate of Calcium, Sulpho stibtaa-ealeiut. Ca^SbS\— Ftodneed
like the barium-salt, but cannot be crystallised. A mixtore of this oompoond vith
excess of lime and saffiron of antimony, constitutes the pharmacentiod preptntion
known as Calx antimonii cum sulphure Hoffmanni^ Sulpturetum stibu cuan cake^ at
Calcaria sulphurata atibiata^ discoTered by Hofiinann in the eighteenth oentmy. It
is prepared by igniting an intimate mixture of 3 pts. trisulphide of antimony, 4 pts.
Ruh)hur, and 16 pts. quicklime ; or 8 pts. of prepared oyster sheUs, 1 pt anttmany,
ana 2 pts. sulphur. It is a whitish-yellow, yellowish, or brownish-yellow povder, vhieh
has a uiarp sulphurous taste, smells of sulphuretted hydrogen when exposed to moist
air, and is but partially soluble in water. The solution is colourless, and oontaiai
sulphantimonate of calcium*

Sulphantimonate of Cobalt, obtained by precipitation, is black, oxidises in the
ab, and is decomposed by boiling hydrochloric acid.

Sulphantimonate of Copper, Cu'SbS\ — Obtained by dropping a solntioQ of
cupric acetate or sulphate into a solution of sulphantimonate of sodium. The sohtioBi
must be rather dilute ; the copper-solution must be dropped in slowly and with npid
stirring ; and thepredpitate then heated, together with the liquid, with brisk stimng
all the while. Without these precautions, each drop of the copper-solution, u it
enters, becomes enveloped by the precipitate ; and if the precipitate be thrown on the
filter in this state, the solution of sulphantimonate of sodium runs away first, and then
the acetate of copper and sulphantimonate of copper decompose each other, acetic sdd
or sulphuric acid oeing set free, which then acts upon the sulphantimonate of sodimn
still remaining in the precipitate, setting free pentasulphide of antimony and hydro*
sulphuric acid. In this manner, the precipitate becomes contaminated with pentasd-
phide of antimony and sulphide of copper. — Sulphantimonate of copper, when pure, is
a dark brown precipitate, which when neated ^ves off sulphur, and leaves a lesidns
apparently consisting of cuprous sulphantimomte (Sb^* with Cu*S). Boiling potash
decomposes the sulphantimonate, separating sulphide of copper and dissolring pents-
sulphiae of antimony, which is at the same time partially converted into sntuDonie
acid.

If sulphantimonate of sodium be added to excess of cupric sulphate, and the pre-
cipitate ooiled for some time with the liquid, a product is obtained containing 16 it
copper, 8 at sulphur, 2 at antimony, and 6 at oxygen, and the liquid exhibits a
strong add reaction :

3Na«S.Sb«S* + 8Cu«S0« + 6H«0 - (8Cu«S + SbK)») + 8Na«S0* + 6H«80*.
The precipitatethusformed,may, as already observed (seeaboTe),beeither3Ca^SiSh9
+ 5Cu«0, or 8Cu«S + 8b«0*. On boiling it with potash-ley, sulphide of cop^
remains behind, and a solution of antimonate of potassium is formed, which gires with
acids a white precipitate of antimonic add. On the other hand, the predpitate, when
quickly and sttpngly heated in dose vessels, gives off a large quantity of gnlphnrons
anhydride, but no sulphur, and the reddue contains sulphide of copper and peotssol*
phide of antimonv. Moreover the same products are obtained by igniting a mixtara
of 8 at. pure sulphide of copper, and 1 at pure antimonic oxide, or of 1 at sulphantimo-
nate of copper and 6 at. cupric oxide. So far then it is impossible to dedde upon the
constitution of the predpitate obtained in the manner just described. Bat when
sulpharsenate of potassium is dropt into excess of cupric sulphate^ and the mixtore
boiled, a predpitate is obtained consisting of pure sulphide of copper, the whole of
the arsenic remaining dissolved as arsemc acid. Hence, from the analogy of the
arsenic and antimony compounds, it is probable that the antimony predpitate above-
mentioned is a mixture of sulphide of copper and antimonic oxide.

Sulphantimonate of Iron. — Ferrous sulphate dropt into sulphantimonate of
sodium forms a black predpitate, which quickly turns reddish-yoUow. The sodinm-sslt
forms with ammonio-ferric sulphate, so long as the latter is in excess, a greenish-brovn
predpitate, consisting merely of sulphur and pentasulphide of antimony, the whole of
the iron being reduceid to the ferrous state and remaining in the liquid.

Sulphantimonate of Lead, Pb'SbS^— Obtained by adding acetate of lead to
sulphantimonate of sodium, with the same precautions as those described for the

ANTIMONY: SULPHANTTMONATES. 337

proparation of the copper-salt Jt is a dark brovn precipitate, which is decomposed
hj heat, giving off 2 at sulphur, and leaving snlphantimonite of lead, 3Pb'S.Sb^", or
Pb'SbS', of the same composition as the mineial Boolangerite. Boiling potash-ley
deoompoees it in the same manner as the copper>salt A precipitate, containing 16Pb,
8S, 2Sb, and 60, is likewise obtained by adding sulphantunonate of sodiom to excess
of acetate of lead.

Sulpkantimonate of Maanesium. — Recently precipitated pentasulphide of
antimony dissolves in aqueous hydrosnlphoric acid, in which magnesia is suspended,
the magnena likewise dissolving ; but the compound cannot be made to crystallise.

Bulphantimonate of Manganese, — Eed-biown precipitate, produced by mix-
ing the sodium-salt with sulphate of manganese; it oxidises during washing and
dzyii^.

Bulphantimonatet of Mercury, — The mercuric salt, 3Hg*S.Sb«S*, or Hg'SbS*,
obtained like the copper- and lead-salts, is an orange-coloured precipitate. K after
washing it be immersed in solution of mercuric chloride, or a solution of sulphanti-
monate of sodium be added to excess of mercuric chloride^ a white substance is formed,
coataining 8He^Sb'S* + 6HgCl + 3HgH). This substance is not a mere mixture,
but a chemiou compound, which is not attacked by any acid except aqua-regia.
Potash decomposes it inmiediately, leaving mercuric sulphide, and dissolving antimonic
and hydrochloric adds. — Mercuroua nitrate, mixed with sulphantimonate of sodium,
fimna a blade precipitate, whichever salt may be in excess.

Bulphantimonate of Nickel, — Black precipitate, which oxidises in the air, and
is deeompoeed by hot hydrochloric acid.

Sulphantimonate of Potassium^ K^SbS^; in the crystallised state 2K'SbS* +
ftH«0, or 3K«8.Sb*S» + 9HK).— The anhydrous salt is obtained by ftwing sulphide of
potasnom with trisulphide of antimoay and sulphur, or sulphate of potassium with
the trianl|^de and charcoal, or by heating one of the potassium-livers of antimony,
in which case metallic antimcmy separates out The product is a brown mass, the
aqueous solution of which yields crystals of the hydra ted salt The latter is, however,
better obtained by boiling a mixture of 11 pts. of finely levigated trisulphide of anti-
mony, 6 pts. of carbonate of potassium, 1 pt of flowers of sulphur, and 3 pts. of lime
previously burnt and slaked, with 20 pts. of water, for some hours, renewing the
water as it evaporates ; or by leaving the same mixture in a covered vessel for 24
hours, and stirring freouently ; then filtering and evaporating. The hydrated salt
forma colourless or yellowish, granular or radiating crystals, which give on tiieir water
when heated.

Sulphantimonate of potassium is likewise formed when pentasulphide of antimony
is boiled with aqueous carbonate of potassium, antimonate of potassium being formed
at the same time, and separating in the solid state. Hot caustic potash-ley dissolves
the pentasulphide completely ; but on diluting the solution, and adding carbonate of
ammonium, a precipitate is formed, consisting merely of the pentasulphide mixed with
a small quantity of sulphantimonate of potassium. Cola potash-ley of moderate
sttrength acts upon pentasulphide of antimony somewhat differently ; the pentasulphide
loses its colour; white acid antimonate of potassium (£'0.2Sb*0* + eHK)) remains
undissolved, notwithstanding the excess of potash present ; free sulphide of potassium
is formed ; and the liquid yields by evaporation a colourless double salt, consisting of
snlj^ntunonate and antimonate of potassium (K'SbS^.KiSbO* 4- 5H'0), ciystallising
in long needles, which, when exposed to the air, become covered with a kermes-
ooloured film. Cold water renders these aystals milk-white, dissolving a portion, and
leaving a white residue of acid antimonate of potassium. Hot water dissolves the salt
readily, and the solution, when mixed with acids, yields an orange-coloured precipitate,
consisting of pentasulphide of antimony mixed with antimonic acid.

Bulphantimonate of Silver, Ag*SbS\ prepared like the lead- and copper-salts
forms a black, perfectly insoluble precipitate, which gives off sulphur when heated,
leaving a fused grey residue of sulphantimonate of silver, Ag'SbS', which yields a red
powder by trituration. — ^By adding snlphantimonite of sodium to excess of nitrate of
sflver and boiling for several hours, a precipitate is obtained containing antimonic oxide,
which may be completely extracted ^m it by potash.

Sulphantimonate of Sodium, Na'SbS* + 9H*0, or ZNa8.SbS^ + 9H0.
BeUipp^s ealt, — ^This salt is prepared by digesting at ordinaiy temperatures in a
receel that can be dosed, and with frequent stirring, a mixture of 11 pts. of elutriated
trisulphide of antimony, 13 pts. crystallised carbKonate of sodium, 1 pt flowers of
sulphur, 6 pts. of ^uick lime previously slaked, and 20 pts. of water. After twenty-four
hours, the liquid la strained off, the residue washed several times with water, and the

Vauh Z

338 ANTIMONY: SULPHO-CHLOBIDE.

Bolation together with the wash-water, is evaporated in a poroelaiii dish or clean iroo
pot, till a sample yidds ciystais on oooUng. The whole is then left to oool qnietlj, and
the resulting crystals are washed several times with cold water, and dried in the air, or
better, nnder a bell jar, over lime or oil of vitrioL The formation of the salt is mnch
accelerated by boiling the mixture. (Liebi^ Handwort d. Chem. 2** AnIL ii. 139.
For other modes of preparation, see Gmelin's Handbook, iv. 384.)

Sniphantimonate of sodium forms transparent^ colourless, or pale yellow, regular
tetrahedrons, with truncated summits, or acuminated with the &oes of the rhambie
dodecahedron. Its taste is bitterly metallic, and at the same time alkalinn. It dis-
solves in 2'9 pts. of water at 15° C, and the solution is precipitated by alcohol. When
heated, it melts in its water of cnrstallisation, and after all the water hae gone oC
forms a greyish-white mass, which crumbles to a bulky powder when exposed to the
air. At a commencing red heat, it fdses, without decomposition, if the air be exduded.
The ihsed mass is liver-coloured, and dissolves in water, leaving a small quantity of
sulphide of antimony. The decomposition of the solution, as weU as of the salt itseli^
by contact with the air, is due to tbe action of carbonic acid, but is not complete even
iJter many months. The resulting brown precipitate contains sulphantamonate of
sodium with trisulphide of antimony, and the liquid is found to contain carbonate,
sulphide, and hyposulphite of sodium, but no sulphatcL

When Bulphiuitimonate of sodium is added to a solution of tartar-emetic, the liquid
first turns rM, and then yields an orange-coloured precipitate containing pentasolphide,
trisulphide, and trioxide of antimony, while tartrate of sodium and potassium remains
in solution :

6C«H«KSbO» + 2Na«SbS« - 6C*H*KNaO« + Sb«S« + Sb»S« + 2SbK)«

This precipitate melts at a high temperature, forming a black metallic-shining masR,
exhibiting red translucence on the edges, and perfectly soluble in hydrochloric addL
Potash decomposes it^ leaving a yellow residue consisting of sulphide of sodium, tri-
oxide of antimony, and a compound of that oxide with potash. (HandworterbucL)

8ulphaniimonate of Strontium.—Trepated. like the calcium-salt: not oys-
talliaable.

Sulphantimonate of Uranium. — ^Yellow-brown precipitate, obtained by adding
ammonio-uranic chloride to sulphantimonate of sodium.

Sulphantimonate of Zinc, obtained by droppinff sulphate of sine into a solution
of the sodium-salt, is an orange-coloured precipitate which dissolves in the liquid when
heated, and partlv runs through the filter during washing. It is decomposed and dis-
solved by h^drodiloric add.

The precipitate obtained with excess of the zinc-sslt, has the same colour, but is not
easily obtained free from the preceding, even after long boiling. Fuming nitric add
decomposes it> witii ignition. (Handworterbuch.)

AMTtMOWTn 8VUPBOCH&OBZDB OV. SbSa*. Obtained by dowly passing
dry sulphuretted hydrogen into pentachloride of antimony. It is a white crystalline
body, which melts at a moderate heat, is resolved at a higher temperature into sulphur
and trichloride of antimony, deliquesces in moist air, anais decomposed by water into
sulphur and trichloride (? oxychloride) of antimonv ; with aqueous tarteric add, it
yields a predpitate of sulphide of antimony mixed with oxide. (Cloez, Ann. Ql
Phvs. [3] XXX. 374.)

Other sulphochlorides of antimony have been obtained by R. Schneider (Pogg.
Ann. cviii. 407). Finely pulverised trisulphide of antimony dissolves in 14 or 15
times its weight of the melted trichloride, without evolution of sulphuretted hydrogen,
and the light brown solution solidifies on cooling to a yeUow crystalline mass. By
pouring off the stiU remaining liquid at a certain stage of the solidification, the com-
pound may be obtained in regular crystals (rhombic prisms bevelled at the ends with
a macrodiagonal dome), contEiining Sb^Cl^.fiSbOl*. It is very deliquescent, and is
decomposed by a large quantity of water, with separation of a yellow powder ; l^
prolonged heating, it ia resolved into volatile trichloride of antimony, and a Uack
residue of sulphide. It is decomposed by absolute alcohol, out of contact of air, a
large quantity of chloride of antimony and a little of the sulphide dissolving; and a
reddish-yellow amorphous substance being left, containing 2SbC]S.3Sb'8*. This com-
pound is decomposed, by heating in dose vessds, into trichloride and trisuj^hide of
of antimony, also by the action of dilute hydrochloric add.

AJITIMimf SOU^HZODXBB OV. SbSI. — This compound is obtained by S»-
solving trisulphide of antimony in the mdted tri-iodide. It has a brilliant metallie
lustre and nsi-brown colour, appears red and transparent under the microscope, and
3rields a powder of a fine cheny-red colour. (R. Schneider, J. pr. Chem. ]xxi±.
422; lUp. Ohim. pure, ii. 323.)

ANTIMONY-RADICLES (ORGANIC). 339

When a mixtim of equal ports of iodine and trisulphide of antimony is slowly
heated in a letort^ an iodoenlpbide, probably of the same composition, rises in red
Taponia, irfaich condense in the reeeiTcr. Tlie same body is formed by subliming a
suxtnre of 24 pts. antimonT, 9 pts. sulphur, and 68 pts. iodine, or of 2 pts. iodine and
9 pta. iodide of sulphur, ft forms shixung transparent, blood-red needles and laminae,
vni«^ melt at a gentle heat, and sublime more easily than the iodide of antimony. It
has a pungent taste and repulsire odour. It is decomposed at a strong heat, also by
chl<xine and by water. Henry and Garot (J. Phaim. z. 511), assigned to this pro-
duct the fonnua 8bffP; but this is doubtless incorrect.

OWMAMliJm Antimony combines with alcohol-
radicles in yaiious proportions, forming compounds which themselyee act like simple
radakles^ uniting with chlorine, oxygen, sulphur, &&, in the same manner as the
metaia. Some of these bases are formed on the type of ammonia, NH', containing
I aL antimony.Qnited with 3 at of the alcohol-radide ; others on the type NH* ; and a
eompound of antimony with amyl is known containing 1 at antimony with 2 at amyl.
The names and fonnulse of the antimony-radides at present known, are given in the
fiollowing table : —

Antimonides of Amyl :

Stibdiamyl Sb(C»H»)«

Stibtriamyl or Triamylstibine .... Sb(C*H")«

^nfa'in4i,tii<lAa of Ethyl :

Stibtriethyl or Triethylstibine .... S^CH*)*
Stibethylium or Tetzethylstibomum . . . Sb((7H*)«

Antimonides of Hethyl :

Stibtrimethyl or Trimethylstibine . . . Sbf CH*)*
Stibmethylium or Tetramethylstibonium • • Sb(CH'/

The existence of pentethylstibine Sb((>H*)* and pentamethylstibine Sb(CH')* has
abo been rendered probable by the recent experiments of Mr. Buck ton (Chem. Soc
Qn. J. ziii 115).

Hie compounds containing 3 at of alcohol-radicle are obtained by distilling the iodides
of the alcohol-radicles with antimonide of potassium or sodium, or by the action of tri-
chloride of antimony on zinc-ethyL They are liquids which volatilise without decom-
poftition, and rapidly absorb oxygen from the air, with great evolution of heat sufficient
in the case of the ethyl- and methyl-compounds to produce vivid combustion. The
compounds containing 4 at of alcohol-radide are not known in the free state; but
tbor iodides are obtained by treating the coiresponding compounds containing 3 at.
aloohol-radicle with the iodides of Uiose radides ; and these iodides when treated
with oxide of silver and water, yidd the hydrated oxides of the same radides, which
are fixed bases, having a strong alkaline reaction, and uniting readily with adds like
the hydrates of potassium and sodium. In this respect they resemble the correspond-
iiwiutrogen-basea, hydrate of tetrethylium, N(O^M^.H.O, &c

llie antimony-radides containing 4 at of the alcohol-radide, are monatomic, uniting
with 1 at chlorine, iodine, &c. ; but those which contain 3 at alcohol-radide, stibtri-
ethyl, for example, are diatomic, uniting with 2 at chlorine, iodine, &c, and with 1 at
oxygen, c^. Sb(C*H»)«.Cl«, Sb(C*H»)K), &c The same hiw holds good with respect
to other ozgano-metallic bodies similarly constituted, arsentriethyl, for example : but it
does not extend to the corresponding nitrogen-radides, such as triethylamine, tri-
methylamine, &c., which, indeed, do not unite directly with oxygen, chlorine, iodine,
^ce^ but combine with hydrated adds in the same manner ss ammonia.

ABttmoaldaa of Amjl« •r Stibamjla.*

These eomponnds are obtained by the action of iodide of amyl on antimonide of
potaflnmn, the process being conducted similarly to that for the preparation of stib-
ethyl (p. 84 IX After the action has ceased, and the excess of iodide of amyl has dis-
tflled oS, the residue is either distilled in an atmosphere of carbonic anhydride, whereby
a distillate is obtained containing stibdiamyl ; or the product is exhausted with ether,
and the solution freed from ether by distillation, in which case a residue is left con-
sisting of stibtriamyl. If the stibtriamyl thus obtained is contaminated with amylic
alcohol or iodide of amvl, pore compounds may be prepared from it by dissolving it in
a mixtore of ether and alcohol ; adding alcoholic bromine till its colour just begins to
be permanent; jpredpitating the bromide of stibtriamyl by adding a large quantity of
vattf ; oonveitu^ the bromide into oxide by means of oxide of silver suspended iu

* F. BcrU, J.pr. Chera. Uv 885; Qm. xl. US.

340 ANTIMONY-BADICLES (OBGANIC>

alcohol ; precipitatiiig the oxide by water, and diasolTmg it in hjdrodilonc add and
alcohol ; precipitating the pare chloride by another addition of water ; and freeisg it
from a small qoantitT of water by heating it to 100^ C. in contact with foaed cUonde
ofcaldom.

Stibdiaxtl. Sb(G*H")* ^ SbArn*. — The distillate just mentioned, after being
freed from nndecomposed iodide of amyl by re-distillation orer antimonide of potaaniun,
gare off at 80^ C. a oolonrless liquid, which bomt with a white flame, diffiising a wMte
smoke of oxide of antimony. The liquid which then remained was stabdiamyL It vas
greenish-yellow, heayier than water, and tolerably mobile, with a peculiar aromatic
odour and bitter taste ; insoluble in water, but misdUe in all proportioDs with aloohol
and ether. It was not spontaneously inflammable, but when set on fire, homed vi^
a very white flame, diffusing a white fume of oxide of antimony. It eamloded with
great yiolence when heated in oxygen gas, and was decomposed by nitnc add vith
considerable erolution of heat. Its ethereal solution exposed to the air, left an oxide
which absorbed carbonic acid ; and the stibdiamyl itself heated to 100^ C. in a
stream of dry carbonic acid, yielded a yiscid liquid, which appeared to be the cl^
bonate (SbAm')*.CO'. The haloid salts of stibdiamjl are gummy liquids; the
sulphate and nitrate are precipitated from their alcoholic solutions by water, in the
form of gummy masses, which dry up to amorphous solids.

STiBTBiAMTLorTBii.KTLSTiBiirB. Sb(C*H")* » SbAm*.— Transpsmit dightlj
yellowish liquid, yeiy viscid below 20^ C, more mobile at higher temperatures. Ithn
a peculiar aromatic odour, and a bitter, somewhat metallic and yery persistent taste.
Specific grayity 1*333 at 17^ G. (according to Cramer, Pharm. Cen^. IS66, 465,iti9
1*0587). In contact with the air, it does not take fire, but fumes strongly anddNOBh
poses, depositing a white powder. A drop of it placed on bibulous n;ptr and eqxsed
to the air, becomes so strongly heated as to char the paper. It is insoluble imrater,
but dissolyes sparingly in alcohol, and readily in etaer. It does not exhibit wj
tenden<7' to umte witn iodide of amyl, when heated with that compound in a scaled
tube.

Stibtriamyl is a diatomic radicle, like stibtriethyL Its oxide, S^C^H^^.O- is pio-
duced by slow eyaporation of an ethereal solution of stibtriamyl in contact witli the air ;
or by decomposing the chloride, iodide, or bromide with oxide of silyer. It is a gie^Fish*
yellow yiscia mass, which becomes somewhat more fluid when gently heated, bat
decomposes at higher temperatures. It tastes and smells like the r^de itsell It vi
insoluble in water, sparingly soluble in dilute alcohol and in ether, but disaohes
easily in absolute alo(MioL The alcoholic solution precipitates metallic oxides from
their salts. Oxide of stibriamyl dissolyes readily in acids, and the resulting oompoonds
are precipitated from their solutions by water.

1. The chloride, Sb(C^H")*a*, obtained by dissolying the oxide in hydioefaloric
acid, is a yellowish translucent Hquid, yisdd at ordinary, comparatiyely mobile at higher
temperatures, heayier than wat^, soluble in alcohol and etner. It tastes and smells
like stibtriamyl Decomposes at temperatures aboye 160^ C. The bromide uaiwdUt
resemble the chloride.

Nitrate. Sb(C»ff>)«.2N0«.— When the chloride or iodide is mixed with an alooholie
solution of nitrate of silyer, as long as a precipitate forms, and then filtered, the filtrate
forms an emulsion, from which, after standing for some time in a warm plaee^ tvo
liquids separate, the upper being light, yellow, and mobile, and the lower a de^
brown-red oiL The upper layer, when slowly eyaporated, yields the nitrate in slender
white crystals grouped in stars ; they may be purified by recrystalUsation from dihte
alcohol. The dark red oil likewise dissolyes on addition of a large quantity of
hydrated alcohol, and the solution, after standing for some time, yields the same an*
tals. These crystals melt at about 20° C: the fSsed mass does not dissolye in alcohol
so readily as the crystals. This salt, the only czTstallisable compound of stibtriamjl
is insoluble in water and ether, but dissolyes in hydrated alcohoL It has a peeobar
metallic taste.

The sulphate, Sb(C*H")'.SO^ is formed by decompc«inff eqoiyalent quantities of
sulphate of silyer and a haloid compound of stibtriamyl dissolyed in alcohcJ. This salt
was obtained only as an oily liquid body.

The white powder, formed by the action of the air upon stibtriamyl is insohible in
ether, alcohol, and water: it does not dissolye in hydrochloric acid, but imperfeetlj in
fuming nitric acid ; slowly in aqna-regia. It remains unaltered eyen when strong
heated, not decomposing below a red heat Berld supposes it to be antimottite of^
triamyl, SbAm'O.SbK)'. When sulphuretted hydrogen was passed for some time
through this compound suspended in alcohol, a white powder immediatdy separated,
which gradually assumed an orange colour, and then formed a pulpy masa, which eoald
not be filtered. After addition of a large quantity of alcohcM and etiier the liqM

ANTmONY-BADICLES (ORGANIC). 341

vhen left to stand in a wann place, deposited an orange-ved, fioccnlent precipitate,
vhidi, after dxyin^ Ibrmed a brownish-yellov powder, inaolnble in alcohol, ether, and
vater ; thia powder decomposed at a yery nigh temperature, and took fire when
faming nitric acid was ponred npon it. BerU regards this compound as stUphanti'
manite of sUbtrian^lt obAm'S.Sb'S' (it gave 18*38 per cent, sulphur, the formula
requiring 17*59). A compound, supposed to be identical with this, is formed by
p— "'"g snlphuretted hydrogen for some time through an alcoholic solution of oxide
of st&btEiamyL

AntlmMildmi of atbylt or Bttbatlijls.

Stibtbisthti. or Tbiithtlstibins, commonly called iSS^^Ay/. Sb(CH^)'a
Sb£*. (Lowig and Schweizer, Ann. Ch. Fharm. Ixxy. 315, 327; Lowig, Und, bccx.
323 ; Gm. ix. 79 ; Oerh. iL 370.) — This compound is prepared by the action of iodide of
ethyl on antimonide of potassium. The alloy is fine^ pulyerised together with two or
three times its weight of quarts-sand (if pulyerised alone it is apt to take fire) ; the
mixture is intioduora into a number of small short-necked flasks, so as to fill them to
about two-thirds ; and iodide of ethyl is added in quantity just sufficient to moisten the
mixture of alloy and sand. The action begins in a few minutes, and is accompanied with a
rise of temperature sufficient to Tolatilise the excess of iodide of ethyl, whicn is collected
by itself in a small receiyer; as soon asthis action is oyer, the flask is connected as
quiddy as possible with a condensing apparatus, through which a stream of carbonic
acid gas is passed during the whole operation. This condensing apparatus consists of a
tall wide cylindrical yessel dosed by a cork haying three apertures. Through one of
these apertures; passes a tube proceeding from, the carbonic acid apparatus, and reach-
ing to the bottom of the yessel; through the second a short straight tube to carry off
that gas» and through the third is inserted the distillation tube connected with the
flask containing the mixture : this tube descends nearly to the bottom of the glass
^linder, and £ops into the mouth of a small receiyer, partly filled with antimonide of
potaasinm. This apparatus being completely filled with carbonic acid gas, the gener-
ating flask is heatea yety gently at flrst, and afterwards more strongly as long as any
liquid distils oyer. This flask is then remoyed, the distillation-tube stt^yped with
wax, till a second flask is ready to be adapted, and the operation is then repeated.
The contents of 20 to 24 flasks of 3 or 4 ounces capacity yield 4 or 6 ounces of crude
product, which may thus be obtained in the course of a day. The receiyer in which
the distillate has been collected is then closed while still immersed in the atmosphere
of caibonie acid, afterwards remoyed, and used as a retort in the rectification of the
pKoduet, the same condensing apparatus being used as before. The first portions of
the rectified product contain iodine, and deposit after a while, a number of colourless
crystals consisting of iodide of stibethylium. (Lowig and Schweizer.)

2. By the sction of trichloride of antimony on sine-ethyl, similarly to the preparation
of triethylphoBphine. (Hofmann: See Phosphobus Basbs.)

I^vperiies. Stibtrieth;^ 1 is a transparent, colourless, mobile, strongly refincting liquid,
haying a disagreeable alliaceous odour. Specific grayity 1*3244 at 16^ C. It does not
eolidi^ at 2^ C. Boils at 168^*5 (bar. at 730 mm.). Vapour-density, by experi-
ment SB 7*44 ; by calculation 7*18, tiie formula 8b(C'H*)', representine 2 yolumes of
yapour. Stibtriethyl is insoluble in water, but dissolyes readuy in alcohol and ether.

A drop of stibtriethyl exposed to the air at the end of a glass rod, emits thick white
ftimes, and in a few seconds takes fire and bums with a white, strongly luminous
flame. When introduced in a thin stream into oxygen gas, it bums with dazzling
brightness. But if it be made to run into a glass globe containing air, in such a
manner as not to take fire, it giyes off dense white fumes, which collect on the sides of
the yessel in the form of a powder, which is insoluble in ether, bat dissolyes in
alcohol and water; at the same time a transparent, colourless, yiscid mass is formed,
which is soluble in ether. This latter substance is the oxide of stibtriethvlf SbE'O ;
the powder is animonUe of stibtriethyl, SbE'O.SbK)'. Stibtriethyl oxidises yery
dowfy when immersed in water ; hence it is best to keep it under that liquid. Stu-
phuTf selenium, iodine, bromine, and chlorine combine directly with stibtriethyl, the
action bein^ always attended with eyolution of heat^ and in the case of bromine and
^orine, with inflammation. The compounds contain 1 at. stibtriethyl, with 1 at. of
a dibasic radide, O, S, SO^ &c., or 1 at. stibethyl with 2 at of a monobasic radicle,
CI, Br, KO*, &c, in which respect they resemble the compounds of stibtrimethyl, ar-
sentriethyl (see p. 822). Stibtriethyl introduced into hydrochloric amdgcis, yields chlo-
ride of stibhiethyl and free hydrogen :

sbE» + 2Ha » sbEH:a« + m

The SBBie reaction takes place with ftmiinff hydrochloric acid. Dilute nUnc acid, with
the lid of hQit» acts on stibtriethyl in the same manner as on the metals, eyolying^

% 3

342 ANTIMONY-RADICLES (ORGANIC).

nitric oxide and forming nitrate of stibtriethyL Neither faming nitric add nor aqoa*
regia oxidises the antimony completely.

Antimonite of Stibtriethyl, Sb(0•H»)•.Sb*0^ or SbEK).Sb«0«, is formed, together
with the oxide, by the gradual oxidation of stibtriethyL The white ftmes vbicfa
stibtriethyl diffiises in the air consist almost wholly of this oomponnd. It may be pre-
pared by leaving an ethereal solntion of stibtriethyl to evaporate Bpontaneoosly, and du-
solving out the stmnltaneously formed oxide with eth^-alcohoL The antimonite then
remains as a white, pnlvemlent, amorphous body. It has a bitter taste, and is soluble in
water and in alcohoL The aqueous solution i«epared in the cold is perfectly mobile,
but when heated, becomes viscid like starch-paste, and dries up to a friable masR,
having the appearance of porcelain. Water poured upon this mass dissolves the
greater part^ but leaves a small residue of antimonious oxide. Hydrochloric add,
added to the alcoholic solution throws down chloride of stibtriethyl; the acid liqn^
separated from the chloride yields with sulphuretted hydrogen, a precipitate of kermeB;
on mixing it with water, powder of algaroth is precipitated. (Lowig.)

Bromide of Stibtriethyl. Sb(C«H»)«Br*. -Stibtriethyl takes fire when added I7
drops to bromine. The bromide is prepared hj adding a recently prepared aloohoUc solo-
tion of bromine to an alcoholic solution of stibtriethyl cooled by ioe, as long as the ooloor
of the bromine disappears. On mixing the solution with a large quantity of water, the
bromide of stibtriethyl is precipitated, in the form of a colourless liquid which most then
be washed with water and dried by contact with chloride of calcium. TransparflDt,
colourless, strongly refracting liquid, having a density of 1*953 at 17^ C. Has an on-
pleasant odour like that of turpentine, and excites sneezing. Solidifies in a ciystalline
mass at — 10^ 0. It is not volatile. When distUled, it yields, among other ppodneU
a strongly acid liquid having an intolerable odour like that of chlonl It is decom-
posed by oil of vitriol, with evolution of hydrobromic acid, and by chlorine with separa-
tion of bromine. Insoluble in water, but dissolves readily in alcohol and e^er. The
alcoholic solution gives with metallic salts, reactions similar to those of bromide of
potassium.

Chloride of Stibtriethyl. Sb(0<H*)H31*.— Stibtriethyl diopt into ehiorine gu
takes fire and bums with a bright but smoky flame. Introduced into dry hydrochloric
acid gas, it forms chlpride of stibtriethyl, and separates a quantity of hydrogen equal in
volume to half the hydrochloric acid gas. The chloride is easily obtaued in the pore
state b^ decomposing a strong solution of nitrate of stibtriethyl with strong hydroehlorie
acid ; it then separates in the form of a liquid which may be purified in the same
manner as the bromide. Transparent, colourless liquid, of specific gravity 1*640 at
17° C ; it has a powerful odour like that of torpentwe, and a bitter taste. Bemains
fluid at 12^ G. When it is distilled with water, a small portion appears to volatilifie
undecomposed ; when heated alone, it behaves like the bromide. Strong snlphnrie
acid decomposes it, with evolution of hydrochloric acid, while, on the other haad,
hydrochloric acid added to a solution of sulphate of stibtriethyl throws down the
chloride. In other respects, its relations are like those of chloride of potaasiiun or
chloride of sodiunu It is insoluble in water, but dissolves readily in alcohd and ether.

Cyanide of Stibtriethyl appears to be formed when 2 at. cyanide of mencoiy,
and 1 at. sulphide of stibtriethyl are mixed in the state of aqueous solution. Sulphide of
mercury is then formed, together with a liquid which smells like prussic add, and
behaves with metallic salts like cyanide of potassium.

Iodide of Stibtriethyl. Sb{C«H»)«I«.— Iodine and stibtriethyl combine togcAer
under water, with rise of temperature. On adding iodine to an ethereal solution of stib-
triethyl, a violent momentary ebullition takes places, and the iodine quickly disappears.
The iodide is, however, most easily prepared oy adding iodine in small portions to an
alcoholic solution of stibtriethyl surrounded by a frigorific mixture, as long as the coloor
of the iodine disappears, and leaving the colourless solution to evaporate. The iodide
then crystallises in colourless needles, which must be recrystallised frx>m alcohol, and
afterwa^rds from ether, to free them from a small quantity of adhering yellow powda.

Iodide of stibtriethyl has a slight odour of stibtnethyl and a bitter taste. ItaissolTes
in water without decomposition and readily in alcohol and ether. It melts and
solidfies at 70^'5 C, sublimes in small quantity at lOO^', without alteration, bat is
decomposed at a somewhat higher temperature, with formation of dense white fames.
In the fused state, it is instantly decomposed by potassiuMf with separation of stibtri-
ethyl. With sulphuric acid and with metdlic salts, it bdiaves like iodide of
potassium. Hydrochloric acid immediately precipitates chloride of stibtriethyl Bro-
mine and chlorine separates the iodine ; so likewise does nitric acid, forming nitrate of
stibtriethyl. With einc-ethyl it appears to form stibpentethvl, SbtE*I' + Zn£ »
2ZnI -t- SbE'' ; but this compound is decomposed by distillation mto 8tibt(ietiiyl, stlV'

ANTIMONY-RADICLES (ORGANIC). 348

knep and hydride of ethyl; Sb(G>H*)* -> Sb(C>H»)* + 0>H« + C^«. (Bnckton,
Cbem. Soc. Qn. J. ziiL 116.)

Oxyiodide of Stibtrieihyh (;SbE')^PO « Sb£'P,Sb£'0.— Produced by the
action of ammonia on iodide of stibtriethyl :

aSbET + 2NH» + H«0 - (SbB^«I*0 + 2NH*I

also by mixing the oxide and iodide of crtibtrethyl in equiyalent quantities. It forms
octahedral eiyiBtals containing 36*9 per cent, iodine: by calculation 37*1 (Strecker
Ann. Ch. Pharm. cvL 806). Merck, who obtained this compound by mixing iodide of
stibtriethyl with an ethereal solution of stibtriethyl in an atmosphere of carbonic anhy-
dride, siippoeed it to be, not an oxyiodide, but a monoiodide of stibtriethyl SbE'I, and
explainea its formation, together that with of another crystalline compound — not
analysed, but supposed to be SbE*HI, — on the hypothesis that the iodide of stibtri-
etfajl prepared by Lowig and Schweizer, really contained 1 at. hydrogen more than
those ehemiats supposed, its true formula being SbE*HI* or SbE*LHI :

ShE*HI* + SbE» « SbE^ + SbE*HI.

But the formula SbE*.! Ib contraiy to analogy, the triethyl- and trimethyl-compounds of
anenic, bismuth, and phosphorus, all uniting with 2 at J, Br or CL Moreover Merck's
mode of preparation, which consisted in corering the liquid with a funnel, and passing
a stream of carbonic anhydride through the beak, till all the ether was evaporated,
was not very well adapted to exclude tne air perfectly ; hence it is probable, especially
as the action took place but slowlr, that oxide of stibtriethyl was first formed, and
then combined with the iodide. The oxyiodide miffht^ however, be formed without
aeeefls of air, if the mixture was not perfectly dry, the compound SbE'HI being pro-
duced at the same time : thus,

2SbE« + 2SbE^* + H*0 - (SbE«)«IK) + 2SbE»HI

The oiTfiodide treated with hydriodic acid yields iodide of stibtriethyl and water :

(SbE^*I«0 + 2HI - 2SbE^ + H«0

With oxide of silver, it yields oxide of stibtriethyl, SbE'O, and with chloride of
mercmy, an oxychloride of stibtriethyl, (SbE*)<GlH). (Strecker.^

Mevdc soppooed that the action of various mercury and silver-salts on his supposed
iodide, Sb£?X, yielded a series of oompoxmds of analogous constitution, vis. a chloride,
Sb£^ an oxide (SbE*)K), 4to.

mtrate of Stibtriethyl. Sb(0«H»)».2N0*.— Obtained by saturating dilute nitric
add with oxide of stibtriethyl, or by dissolving stibtriethyl in the dilute acid with the
aid of heat. In this latter reaction, nitric oxide is evolved, and a small quantity of
antimonioas oxide separates. The salt may be obtained in crvstals by evaporating the
flolntion. At 62^-6 0. it melts into a transfMirent liquid, which solidifies to a crystal-
line mass at 67^ ; at a higher temperature, it deflagrates like a mixture of nitre and
chaiooaL It ^tissolves easily in water, less easily in alcohol, and is nearly insoluble in
ether. The solutions have an add reaction and bitter taste.

Oxide of Stibtriethyl. Sb{C«H»)"0.~Formed by the direct oxidation of stibtri-
ethyl, dther in the free state, as above mentioned, or dissolved in alcohol or ether ; as
thus obtained, however, it is always more or less mixed with antimonite of stibtriethyl,
especially when obtained firom the ethereal solution. The alcoholic solution on tne
contrary yields but a small quantity of antimonite. Accordingly, the oxide may be
obtained by leaving a dilute alcoholic solution to evaporate slowly in a loosely covered
fbot-glaas, treating the residue with ether, which dissolves the oxide and leaves the
antimonite, and repeating this treatment as long as the ether leaves any insoluble
reddne. — ^The oxide may also be obtained by treating an aqueous solution of sulphate
of stibtriethyl with baryta-water; evaporating the filtrate over the water-bath; ex-
hausting the leddue with alcohol, whicn dissoTves out a compound of oxide of stibtri-
ethyl and bar^; predpitating the baryta by carbonic acid, and evaporating the
filtered alcohohc solution. An alcoholic solution of stibtriethyl shaken up with finely
divided red oxide of mercury, quickly reduces the mercury to the metallic state, and
yields pure oxide of stibethyl.

Oxioe of stibtriethyl in its purest state, is a transparent, colourless, viscid, amorphous
mass, which dissolves readily in water and alcohol, somewhat less readily in ether ;
has a very bitter taste ; does not appear to be poisonous ; is not altered by exposure
to the air ; is not volatile ; but when heated in a tube, gives off white vapours which
bum with a bright flame, and leaves a residue containing antimonv and cnarooaL It
iadeeomposed hj potassium^ at a gentle heat, with separation of stibtriethyl FwMfng
mtrie add decomposes it, with evolution of li^ht and heat ; dilute nitric and strong
mdfkurie add dissolve it> forming salts of stibtnethyl ; hydrochloric acid and other hy-
dvogen-aeida diMolve it in the form of chloride of stibtriethyl and dmilar oompoundm

s 4

344 ANTIMONY-RADICLES (ORGANIC).

Hydrotulpkurie acid has no perceptible action upon it ; but on evmpoisting a loiotioB
of the oxide saturated with the gas, ciystals of sulphide of stibtriethyl are obtained; the
smallest trace of antimonite of stibtriethyl mixed irith the oxide is detected by the
formation of a yellow precipitate.

Sulphate of Stibtriethyl^ Sb(C*H*)'.SO*, is obtained by deoomposmg the aqueous
solution of the sulphide with sulphate of copper. It crystallises in small white prisma,
soluble in water and alcohol, inodorous, but naTing a bitter taste and add readioo.

Sulphide of Stibtriethyl, Sb(C*H*)*S, is formed, with oTolution of heat, when sul-
phur and stibtriethyl are brought together under water. But it is most readily obtuned
by boiling an ethereal solution of stibtriethyl with flowers of sulphur; the liquid decanted
from the sulphur soon solidifies in needle-shaped crystals, which may be purified by
leaving the adhering sulphur to oxidise in the air, and crystallising seTcnl tunes from
ether. Sulphide of stibethyl thus purified forms a bulky mass, having a silveiy Instze,
an unpleasant odour, and a bitter taste ; it is permanent in the air when dry, melts
aboTe 100° C, and is decomposed by a stronger heat, with evolution of stibtriethyl va-
pour. The aqueous solution of the sulphide precipitates metals from their BolutioDS
as sulphides, and yields sulphuretted hydrogen with dilute acids.

Sutphantimonite of Stibtriethyl. SbE".Sb^*, or SbE*S.Sb«S«.— Snlphnretted
hydrogen passed through a solution of the antimonite, throws down this oomponnd in
the form of a light yellow precipitate, having an extremely unpleasant, persistent odour,
like that of mercaptan. The compound is also formed by adding recently piecipitatid
trisulphide of antimony to a solution of sulphide of stibtriethyl, the latter being in ex-
cess, whereupon the brown-red colour of the kermes immediately chanees to light yellow.
Dried over sulphuric acid, it forms a powder of a beautiful light yeUow colour, vhich
changes to brown-red at the heat of the water-bath. When distilled over a spirit-
lamp, it yields a liquid distillate having all the properties of sulphide of stibtriethjL
Dilute smphuric acid poured upon it, separates trisulphide >of antimony, with eTolntun
of sulphuretted hydrogen, and formation of sulphate of stibtriethyl :

SbE«.SVS« + SO*H« « SbE».SO* -i- H«S + Sb*S*.

Fuming nitric acid decomposes it, with emission of light and heat.

Stibbthtliuk. Sb(C"H»)* « SbE*. (R Lowie, J. p. Chem. Ixiv. 416; Chem.
Soc QiL J. viiL 261 ; Gm. x. 627.) — The iodide of this ladide is formed by intro-
ducing a mixture of equal parts of stibtriethyl and iodide of ethyl into a retort filled
with carbonic acid gas, nearly filling the retort with water, sealing the ned:, and then
heating it in boiling water. The solution evaporated and cooled, yields beantifhl hexa-
gonal prisms, often an inch long, containing 2Sb£^I.3H'0, and other cmtals, oon-
taining 4SbE^I.3H*0. The salt has a yeiy bitter taste, and 1 pt. of it wdxa in
6 '26 pta. of water at 20° C . It dissolves more easily in absolute alcohol, but lees in ether.
The solution of this salt, mixed with chloride of mercury, forms a white precipitate, which
dissolves in warm water, and yields crystals containing 3HgI.Sb£*L Another doaUe
iodide, 3HgI.2SbE^I, is obtained by adding iodide of mercury to a hot solution of iodide
of stibethyUum.

The iodide digested with oxide of silver, yields a strongly alkaline solution, which
when evaporated, leaves the hydrate of etihethylium in the form of a thick oolonriesi
oily liquid, having a strong alkaline taste and reaction. It expels ammonia from its
compounds, precipitates metallic oxides, and redissolyes alumina and stannic oxide. It
dissolves in acids, forming salts which have a bitter taste. The carbonate is a toogh
deliquescent mass. T)ie^tjUphate and nitrate crystallise. The formate yields need^
shaped crystals, difficult to dissolve. The acetate forms similar crystals, but more
soluble. The oxalate crystallises ; the succinate does not. The neutxal tartrate and
racemaie form large deliquescent crystals ; the acid tartrate, fine needles.

The sulphide, (SbE^)*S, is obtained by treating the oxide with hydroeulphnrie add.
It is a yellowish oily liouid, soluble in water and alcohol, and exhibiting the reactioDs
of alkaline sulphides. — The bromide and chloride are crystalline compounds obtained
by saturating the oxide with the corresponding acids. The chloride forms with chloride
of mercury, compounds analogous to the double iodides above mentioned. It also com-
bines with dicmoride of platinum, producing the compound 3PtCl'.2Sb£H]Sl, which
forms fine yellow crystals, soluble in water and alcohoL

▲ntimonldes of Vietbjl,*

Stibtbimbthtl. Sb(CH")" — SbMe*. — ^Produced, likethe corresponding ethyl-com-
pound, by the action of iodide of methyl on antimonide of potassium. It is a colonriess
neavy liquid, insoluble in water, sparingly soluble in alcohol, readily in ether. Wb^n
exposed to the air, it gives off thick white fumes, and takes fire, burning with a white

• LandoU, Ann. Cb. Pharm. IxxiiiL 91 ; Om rit SSI ; QerluL 646.

ANTIMONY-RADICLES (OEGANIC> 845

iUme and depofiitmg metallic antimony. Its oompoundB are precisely analogous to
those of stibtnetfayL

SabpentameA^t 8b(CHFf, appears to be produced by the action of xinc-ethyl on
stibtrimethyl ; and to be decomposed by distillation into trimethyl and hydro-carbons.
(Bnekton, compare page 836.)

Stibmshthtliuil S^CH")* » SbMe^ — This oomponnd is obtained as an iodide
by the action of iodide of methyl on stibtrimethyl. It is not quite certain whether it has
yet been isolated. The iodide distilled with excess of antimonide of potassium, in an
atmoflphere of carbonic anhydride, yields a spontaneously inflammable oily liquid, re-
sembbng stibtrimethyl ; and the aqueous solution of the iodide subjected to the action
of the electric current yields iodine at the positiye pole, while at the negatire pole, the
liquid becomes alkaline, and gives off a spontaneonsljr inflammable gas containing
antimony, and havingthe odour of stibtrimethyl ; but which of these products, if either,
u stibmethyHmn, has not yet been ascertained.

The compounds of stibmethylium closely resemble the corresponding potassium-salts,
and are isomoiphous with them. They have a bitter taste. They are decomposed by
potash or soda, and then form white ftimes, if a glass rod moistened with hydro-
ehlorie acid is held over them. They are for the most part easily soluble in water,
less soluble in alcohol, and insoluble in ether. The antimony in them is scarcely
recognisable by the ordinary reagents, not being ]^recipitated by hydrosulphuric acid
till after a long time. They yield a slight deposit of antimony, when treated with
rinc and sulphuric addin MarsV s apparatos. They bear a heat of about 140^ C. without
deeomposition, but between 180° and 200° they are decomposed, and give off spon-
taneously inflammable Tapours.

Bromide. SbMe^Br. — Obtained by decomposing iodide of stibmethylium with
bromide of mercuiy. On filtering from the iodide of mercury and evaporating, a
beantifnl salt is obtained, soluble in alcohol and water, but insoluble in ether, and
having a saline bitter taste. This compound, when heated, evolves white vapours
which take fire in the air. Oil of vitriol poured upon it liberates hydrobromic acid ;
nitric acid separates bromine. With metallic salts, bromide of stibmethylium behaves
in the same manner as bromide of potassium.

Carbonates. — 7%e neutral carbonate is obtained by decomposing a solution of the
iodide with recently precipitated carbonate of silver. The filtered lic^xdd evaporated
over the water-bath, leaves an indistinctly crystallised, somewhat yellowish, transparent
mass, which deliquesces very readily in the air, exhibits an alkaline jnietion, dis-
soWea very easily in water and in alcohol, but v^ slowly in ethsr. This com-
pound is very unstable, beginning to smell of stibtrimethyl as soon as it is formed.
When heated, it gives off white fumes, which take fire spontaneously in the air. It
does not appear to contain water of crystallisation. — The aetd carbonate^ (SbMe.H.)CO*,
is Ibrmed by passing carbonic anhydride through a solution of the oxide or of the
neutral carbonate, and evaporating. It crystallises with difficulty in small deliquescent
needles, ananged in stars. In the solid form, it soon decompoBes, like the neutral
earbonate. The aqueous solution evolves carbonic anhydride when heated, and does
not precipitate magnesium-salts.

Chloride. SbMe^CL — Obtained by adding a hot solution of corrosive sublimate to
aqneoQS iodide of stibmethyhum, as long as a precipitate of iodide of mercury is pro-
duced. The filtered liquid evaporated over the water-bath deposits the chloride in
white six-sided tables, similar to those of the iodide. These crystals are easily soluble
in water and alcohol, neariy insoluble in ether : their taste is saline and bitter. This
salt intomesces when heated in a tube, and at a higher temperature gradually dis-
sfipears, giving off white ftmies, which take fire spontaneously in the air, and deposit
on the cooler part of the tube a white sublimate containing chloride of antimony.

CUoroplatinate. SbMeH?LPtGl'. — Obtained as a yellow crystalline precipitate, by
adding meUoride of platinum to chloride of stibethylium. It may be dissolved in
boiling water, and separates on cooling as an orange-yeUow crystalline powder. It is
the least soluble in water of all the salts of stibmeuiylium, and is intermediate in solu-
bility between the chloroplatinates of potassium and sodium. It is quite insoluble in
alcohol and ether, very difficult of solution in alkalis, but dissolves more easily in hot
hydrochloric acid. When heated, it turns black, and soon takes fire, leaving an alloy
of platinum and antimony, from which the latter metal is but imperfectly removed by

Hydrate. SbHeVH.O. — Obtained by agitating an aqueous solution of the iodido
with recently precipitated oxide of silver, filtering from the resulting iodide of silver,
and evaporating the filtrate in vacuo over sulphuric acid. It is a white, crystalline
mass which feels soapy between the fingers, is highly caustic, and dissolves rapidly in

846 ANTIMONT-BADICLES (ORGANIC).

water and aloohol, bat is ioflolnbie in ether. In the state of aqaeons scdntioii, it is
slightly Toktile, and forms white fames when a glass rod moistened with hydrodilorie
add is held over it ; bat the solation, when eraporated oyer the water-bath, yields the
original qaantity with scarcely any loss. When the solid hydrate is suddenly heated
in a test-tube, it gives off yapours which take fire on coming in contact with the
air, and deposit metalHc antimony; but when cazefdlly heated, it sublimes onde-
composed.

The aqueous solution has an alkaline taste and odour, and instantly tarns reddened
litmus paper blue. In all its chemical relations, it exhibits the closest resemblance to
caustic potash« When eyaporated in an open yessel, it absorbs carbonic add, and then
effervesces strongly with acids ; but on the addition of lime-water, carbonate of caldum
is precipitated, and the pure base is again found in the solution. It expels awnmonia
from ammoniacal salts, even in the cold, and separates baryta from iodiae of barium.
IAtm and oxide of lead are immediately precipitated by the solution of this base.
With ginC'talU it forms a white predpitate, soluole in excess ; with copper'Salts a pre-
dpitate insoluble in excess; with fnercurouSf mercuric^ and tUversalts, it g^ves the
same reactions as potash ; with chloride of^aHnum, it forms a yellow predpitate,
i^sembling the chloroplatinate of potassium. The aqueous solution, boiled with eulphttr,
forms a yellow liquid, which, when mixed with dilute adds, yiekb a ptredpitate of
sulphur, and gives off sulphuretted hydrogen.

Iodide of Stibmeihylium^ SbMe^I, is formed by the action of iodide of methyl on
stibtrimethyL If, in the preparation of stibtrimethyl, the iodide of methyl which distils
over at first, and the stibtrimethyl which passes over when the temperature is raised, are
collected in the same receiver, a slight ebullition takes place^ and the liquid miztoie
solidifies after a while inlto a perfectly white, oystalline mass. This is dissolved in
warm water, the excess of iodide of methyl separated, and the solution set aside to
evaporate slowly over the water^bath. The iodide of stibmethylium then separates in
dystals belonging to the hexagonal system. They are remarkably beautifUi, large,
six-sided tables, usually scalariform, and from 10 to 16 millimetres in diameter; Uie
terminal fiices are plane, and the lateral edges intersect one another at angles of 120^.
The crystals contain water mechanically enclosed, and conseouentlv decrepitate when
heated. They dissolves in 3*3 pts. of water at 23^ C, and are likewise easily solnble in
alcohol, but dissolve very slowly in ether. — Iodide of stibmethylium heated in a test-
tube first falls to powder, and at 200^ C. begins to decompose, disappearing gradnaUy,
and evolving thick white fumes, which have the odour of stibtrimethyl. The vapoar thus
evolved is partly deposited as a coating on the inside of the tube ; but the greater
portion reacnes the mouth, Where it takes fire spontaneously, formine rings of smoke
like phosphoretted hydrogen. Boiling water oissolves but a smaU portion of the
deposit in the tube. The solution treated with nitrate of silver, yields a predpitate
consisting of iodide of silver and metallic silver, the latter being doubtless produced
by purestibtrimethyl or stibmethylium, the former by undecomposed iodide. Theaqoeous
solution of iodide of stibmethyhum is gradually decomposed by repeated efxy^oratiom^
a smidl quantity of a yellow insoluble substance (not yet examined) being formed, and
the odour of stibtrimethyl evolved. The yellow substance likewise appears, though not
constantly, when the solution is exposed to sunshine. [For the decompontion by eleetio-
lysis, see page 345.] Filtering paper, covered with strong starch-paste, to whidi iodide
of stibmethylium has been added, behaves towards osone, exactly m the same tn^nnmr as
paper prepared with iodide of potassium, but is even more sendtive. Sulphuric add,
oroTtUnet chlorine, and nitric acid, act upon iodide of stibmethylium exactly as upon
iodide of potasuum ; hydrochloric acid decomposes it, with formation of dUoride of
stibmethylium. Aqueous solution of iodide of stibmethylium poured upon amalgam
of sodium, produces a succession of little explodons, accompanied b^ appearance of
fire, metallic antimony being also separated. The iodide distilled with excess of sii-
timonide of potassium, yiel<u a yellow oily liquid, which is perhaps stibmethylium.
The aqueous solution dissolves a condderable quantity of the yellow modification
of mercuric iodide. The red iodide boiled in the solution dianges into the yeUow
modification before it dissolves ; and as the liquid cools, a condderable portion of the
mercuric iodide separates out, but always in the yellow modification.

Nitrate of Stibmethylium, SbMe^NO". — ^Formed by adding nitrate of silver to
an aqueous solution of iodide of stibmethylium as long as any predpitate is formed,
then filtering and evaporating till the salt crystallises. The crystals are anhydrons.
The salt dissolves readily in water, slowly in alcohol or ether. Its taste is harsh and
bitter, not cooling like that of nitre. When heated, it gives off white fhmea, which im-
mediately take fire ; the entire mass then explodes with a larce white flame, just like
a mixture of nitre and charcoal The salt is very stable, not oeing decomposed, even
by boiling with strong sulphuric add.

ANTIMONY.EADICLES (ORGANIC). 347

8ulpkaU9 of Stibmetkylium.—'T^ neutral sulphate, (SbMe«)<SO\ is obtained
hj Adding a hot sobition of sol^hate of silver to aqueous iodide of stibmethytium, as long
88 anypredpitate of iodide of nlver is f<«med. On evaporating the filtered liquid over
Uie water-bath, eolourksB czTstals aie obtained, which maybe pressed between paper and
dried in the air; also, by saturating a concentrated solution of the acid salt witL oxide of
stibmethylinm, and mixing the aqueous solution with alcohol and ether ; the neutral salt
then separates in oily drops, which after a while assume tiie solid form. The ciystals,
which appear to be rhombic, contain 16*42 per cent. (5 at.) water of crystallisation,
which thi^ give off at 100^ C. Placed oyer sulphuric acid, they loee part of their water,
and &U to a white powder. The crystals dissolve vezy readily in water ; the anhy-
drodfl salt beeomes strongly heated when water is poured upon it. The salt is also
solnble in alcohol, but insoluble in ether. Its taste is saline and bitttf.

Aad Suipkate, (SbMe«).H.SO«. — Obtained by adding 1 at sulphuric acid to an
aqueouB solution of 1 at. of the neutral sulphate. After sevenu czystallisations,
beautiful, hard, transparent crystals are obtained, some of which are four-sided tablets
with obliquely tnmcated ed^;ea. It has a strongly acid taste, leaving a bitter taste in
tibe month. When heated, it behaves exactly like the neutral salphate. On dissolving
it in a small quantity of water, then adding alcohol, precipitating by ether, and re-
peating theee opentioBa several times, the neutral sulphate is at length obtained*
In this respect^ the acid salt behaves exactly like acid salphate of potassium. The
Bait contains no water of crystallisation. The basic water (or hydrogen), like that of
acid sulphate of potassium, is not driven off at 120^ C.

Sulphide^ (SbMe*)^ — "Bte^axed, like monosulphide of potassium, by dividing an
aqueous solution of oxide of sUbmetiiylium into two parts, saturating the one with
hydrosulphuric acid, and then adding the other. The resulting solution, quickly eva-
porated in a retort^ leaves the sulphide in the form of an amorphous green powder,
which smells like mercaptan, dissolves readily in water and alcohol, but is insoluble in
ether. The solutions give black precipitates with lead- and silver-salts. Heated in a
tube, it melts and decomposes, giving off spontaneously inflammable vapours, and
leaving sulphide of antimony. In contact wita the air, it oxidises rapidly.

A solution of hydrate of stibmethylium boiled with sulphur, yields milk of sulphur
on the addition of an acid : hence it is probable that higher sulphides of stibmethylium
may be formed.

STiBTSiifBTHTi.BTH YLiX7]c,Sb(CH')*(CH'), is obtained asau iodide by the action
of iodide of ethyl on stibtrimethyL It closely resembles the iodide of stibmethylium.

Stibkbthtltbibthtliuh, Sb(CH«)rO*H*)" - SbMeE«. (Friedlander, J.pr.
Chem. Ixx. 443 ; Om. xiii 600). — The iodide of this radicle, obtained by the action
of iodide of methyl on stibtnethyl, forms beautiful crystals, apparently having the
form of rhombic prisms, with a glassy lustre when fresh, changing after a while to
nacreous ; they crumble to pieces when dry, but are otherwise permanent in the air.
The iodide has an intensely bitter taste, is inodorous when cold, but at 100^ C. gives
off a peculiar odour, without sensible decomposition. It dissolves in twice its weight
of water at 20^ C, is soluble also in alcohol, but insoluble in ether. The solutions
turns the plane of polarisation to the lefK

Iodide of stibmethyltriethylium forms two double salts with mercuric iodide, viz.
SbMe^I.2HgI, obtained by adding recently precipitated mercuric iodide to a solution
of iodide of stibmethyltriethylium ; and SbMe£*I.3HgI, which is precipitated on add-
ding a hot solution of mercuric chloride to a boiling solution of iodide of stibmethyl-
triethylium, the chloride of the antimony-radide then remaining in solution :

4SbMeI + SHgCl » SbMe£*I.3HgI + SSbMeE«a

This double iodide is insoluble in water; and sparingly soluble in alcohol and ether,
oystallising from the alcoholic solution in yellow needles which melt below 100^ C.

CAloride, Sb]CeEK)L — ^Produced as above, or by dissolving the hydrate or carbonate
in hydrochloric acid, and may be obtained by evaporation in small cnrstalline needles.

Mydraie. — ^Produced (1), by decomposing Uie iodide with moist oxide of silver (when
thus prepsred, however, it always contains silver) ; or (2), by decomposing the sul-
phate with an exactly equivalent quantity of hydrate of barium, and concentrating the
filtrate in vacuo. It is a thick, oily, non-volatile liquid, which has a strong bitter
taste and alkaline reaction, decomposes ammonia-salts, and precipitates metallic oxides
horn, their solutions, the zinc and alumina precipitates being soluble in excess.

Hydrate of stibmethyltriethylium dissolves in acids, forming neutral and acid salts,
which may likewise be prepared by double decomposition from the iodide, chloride, or
sulphate. The salts are more or less soluble in water and alcoho* ; some are deliques-
cent, others permanent. Those which crystallise do not contain water. There are
no basic salts of stibmethyltriethylium.

348 ANTIPHLOGISTIC THEORY - APATITE.

The carbonate, (SbiNLeWy.CO^t is a white resinoiu mass which reacts like cailxmale
of ammonium. The sulphate^ (SbMeE')'.SO* is prodaced by diesolTing the Iiydnte
in sulphuric acid, or bj decompoeing the iodide with sulphide of ^Ter, and may he
obtained, by evaporation in Tacuo, in white, shining^ bitter dTBtab, wfaidi malt it
100° C. and are extremely deUqueeoent^

The acetate, /omuUe, and butyrate are czTStalline. The nevind ostkte,
(SbMeE*)'.G*0^ forms anhydrous glassy needles, moderately soluble in irater. Tbn
acid axaiate, SbMe£*.H.CH)\ forms needles Tery soluble in water. The tartrtk ii
obtained by evaporation as a syrupy liquid which rapidly absorbs water, bat does not
crystallise.

The cyanide is obtained by dissolving the hydrate in hydrocyanic add. The desr
watery solution boiled with potash-ley gives off ammonia and forms an antimonetted
add, which yicdds insoluble or sparingly soluble salts with all basesi eze^ potash,
soda, and ammonia.

IT. See CoMBCsnoir.

See AXTHOKIBBIN.

JLOXD. An add of unknown composition, obtained byUorin
finom the leaves of the fox-^rlove {Digitaiis purpurea). It is prepared by distilling th«
leaves with water, saturating the distillate with baryta, evaporating, distilling the
residue with excess of sulphuric or oxaUc add, and recti^dng over chloride of esJaun.
The add then floats on the top of the liquid in oily drops, having an unpleasant odoor
like that of the plants and producing headache and giddiness. It reddens litmoi
strongly, dissolves readily in alcohol, and in contact with water forms white fihns,
which g^radually dissolve. (J. Pharm. April 1846, p. 299.)

AWTXSUPTIOB. Substances which prevent the spontaneous decomposition of
vegetable and animal substances. They axe chiefly : the minml adds, the alkaline
hypochlorites, common salt, nitre, spices, sugar, creosote and yeast (See FiBimn-

▲TION and PUTHBFJLCnOK.)

AWTXTARTARZO AOIBt also called Lavotartarie and Lmvoraoemh adi
Pasteur has shown that racemic add, which has no action on polarised light, is a com-
pound of two acids in equal proportions, one of which turns the plane of pourisation of a
ray of light to the right, and the other to the left Henoe ne odls these acids le-
spectively, dextro- and lavoracenUc acids, or dextro- and kBVo-tartaric The dextro-
add is identical with ordinary tartaric add. Gmelin (Handb. x. 865) retains the
name tartaric for the ordinary dextro-rotatory add, and distinguishes the hero-
rotating add as antitartaric acid. (See Tabtabzc and Rlgemio Acids.)

AVTBZBKOXJna. A hvdrated silicate of aluminium, found in white stalaetitie
masses on the north coast of Antrim. According to Th. Tho mpson's analysis (J. pr.
Chem. viiL 489) it contains 43*47 per cent, of silica, 30'26 alumina, and 15*32 vater,
together with 7*60 per cent lime, 4*10 potash, 0*19 protoxide of iron, and 0*098
duorine. It appears to be related to mestoype.

AVTSff OI& OV. The red ant {Formica rufa) contains a volatile oil, iHiidi mj
be extracted by distilling the insects with water : to the amount of 0*12 per eent^
according to Nolle ; 1 per cent according to Hermbstadt. It is transparent and colov-
less, and has an agreeable odour ; its taste is not burning. It is slightly sdaUe in
absolute alcohoL (Qm. xiv. 358.)

AM T 1 il»KTWXO ACIB« The name given by Walz to a volatile add, obtained
by distilling toad-flax {Antirrhinum Linaria, JU, lAnaria vulgarity Dec.) vith watff. It
forms a deliquescent barium-salt, the analysis of which gives for the atomic weight of
the acid the number 212.

Syn. with Nitrosalicylamide. See Salictlajodb.

A native basic sesquisulphate of iron « 2(Fe^O".3S0*) -f SFO,
found, in egg-shaped, earthy, yellow masses, in the day, at Heudon and Anteoil, near
Paris.

Phosphate of calcium, — This mineral occurs both masdve and erjt-
tallised. The ciystals are six-sided prisms, belonging to the rhombohednl system,
sometimes passing into the six-sided table ; often hemihedraL Lustre vitieoiis, in>
dining to subresinous. Translucent^ rarely transparent. Sostches fluor-spar, bat is
scratched by felspar. Brittle. Colours, white, wme-ycdlow, green, and red. Speciflc
gravity 3*17 to 3*25. Phosphoresces on coals. Electric by heat and friction. It
occurs in primitive rocks ; in the tin veins of the granite of St Michael's Mount,
Cornwall; near Chudleigh in Devonshire; at Nantes in France; on the St Oothsrd;
and with molybdenum in granite, near Colbeck, Cumberland; also at Ehrenfiifr

APATOID — APHTONITE. 349

dondor^ in Staxmy, in the Tml, in BaTaria^ in Bohemia, and in Spain. Lax^

efystalB are found near New "Xork — one aystal from Bobinson's farm being nearly a

loot in length, and weighing 18 pounds — also in New Hampshire, in Maine, Massa*

chusets, andDelawBjre. A masBiTeyariety called PAoapAort to, because it becomes phos-

phoRfloent by friction, is foond in veins of tin-stone, and likewise in secondary forma-

tiona. A yeiy large Tein of this mineral is fonnd at Estremadnra in Spain. It has a

botrroidal aad kidney-shaped snifiice, and a radiating fibrons texture.

The chemical composition of apatite may be expreoed, according to Gust ay Eose

Ca F
(Pogg. Ann. iz. 185), by the general formula, SPO^Ca' + q ^n, the chlorine and

fluorine^ which are isomorphous, being capable of replacing one another in any pro-
portion whaterer. If the chlorine is altogether absent, the mineral becomes a FIuoT'
apoHU, or FranooHte, SPO^Ca' -f CaF, containing 7*9 per cent, fluoride of calcium,
and 92*31 tribasic phosphate. An analysis of Franoohte by Dr. Heniy gires in 100
pta. 41*34 phosphoric anhydride (P'O*), 63*38 lime (CaH)), 296 protoxide of iron(Fe*0),
2*32 fluorine^ and a trace of chlorine ; whence we may calculate that the proportion '
of tribasic phosphate of calcium is 93*3, and that of the fluoride 4*91 ; part of the
theoretical quantity of calcium is, however, r^kced by the iron. The apatites of the St.
Crothard, of Ehrenfriedersdorf in Saxony, ana of Falmgl and Cbeiner in the l^rol, are
fluor-s^titeeL Apatites tree from fluorine have not yet been found. The neater num-
ber contain chlorine and fluorine together. The la^^est amount of chloride of calcium
is found in the apatite of Snarum in Norway, which contains 4*28 Cad, 1*59 CaF, and
91*13 POH?a'. An apatite in which the fluorine was wholly replaced by chlorine
would contain 10*62 per cent, of chloride of calcium.

The cdoipoaition of apatite is only a particular case of the general formula

(-p « MCI

. 0*.M* j + 2IP in which M denotes a metal, which, in the species hitherto exa-
mined, maybe either calcium or lead, and in which phosphorus and arsenic may replace
each other in any proportion, as well as chlorine and fluorine. This formula likewise
includes the pyromorphites, or green lead-ores, which are isomorphous with apatite.
Apatite was so named by Werner from oawrf ty, to deceire, on account of the mistakes
of the earlier minendo^sts respecting its nature. Even Beiselius was not aware of
the presence of phosphorus in it (Handw. d. Chem. 2** Aufl. ii 147.)

A mineral free from phosphoric acid, found in certain American

• See AxBLAio Aom.
See Abzchite (p. 6).
See DioBrrs.

'• Lamp without flame, or glow-lamp. (See Alcohol,

meteorites.

p. 74.)

Sekie/erspar. Chaux carbonaUe nacrie. — A slat^ carbonate of
calcium, having a mother-of-pearl lustre, found rarely in beds and vems in the older
rocks, as in ComwaU, at Kongsberg, &c A soft friable variety of it, called earth-foam
(Sekaumkalky 8ekaumerde\ containing silica and oxide of iron, is found at Gera, and
at Eialeben in Thuringia.

See TouBXALDCB.

A hydrated silicate of magnesium, resembling meerschaum,
fimnd at Longbanshytta, in Sweden. Its formuhi is 16MgK).16SiO' + 12H*0.
Now in the magnesia-silicates, 3 at water may be supposed to replace 1 at magnesia
(see SiucATBs) hence the preceding formula may be reduced to 4MK).8SiO', or
2M0.8iC^ [H denoting a monatomic metal].

AVMBOM IT All M« (l(^f froth and Arpw soda.) — An old name for the saline
efflorescences formed on walls, commonly caUed taall^itref but consisting for the most
part of carbonate and sulphate of sodium, sometimes with sulphate of magnesium.

AraxOflZnxsmL A silicate of iron and aluminium, containing, according to
Sandbeiger, 26-4 per cent silica, 21*2 alumina, 1*1 magnesia, 44*2 protoxide of iron,
and 7*7 water. Sandbeiger represents it by the formula Z(ZFeO,8iO^) -4-
ZJPCF.SiC^ f 6irO. It is doubtftil, however, whether all the iron exists as protoxide.

See AscAsm.

The name given by Svanberg to a mineral from Warmkog, in
Wirmeland, resembling fahl-ore {q. v,\ but distinguished by a peculiarly large amount
of basic metallic sulphides. According to Svanberg's analysis (Ofversigt af Kongl.

350 APUN — APOPHYJ.LIC ACID.

Vatenskaps Acad. Vorhandliiigar, iy. 85), its general formula is TM^S^*? ; mEbip8a
mixture of 6M'S.Sb%' with M'S. It consists chiefly of copper, smc, sQrer, uon, and
antimony, with only a trace of arsenic. Specific grarily 4*87.

JLraW. — A gelatinons substance extracted by Braconnot (Ann. Gh. FliyB. [S]
iz. 260), from common parsley {Apium petroselinum) by boiling with water. T)ie
boiling liquor passed through a cloth becomes on cooliug a tnuuparent jelly, like
pectic acid. It is washed in cold water, and after drying oyer the wato^bath, is
treated with boiling alcohol and ether, which extract from it a certain quaatity of
chlorophyll.

Pure apiin is a colourless powder, without odour or taste. It melts at 18(f G. into
a yellow liquid, which forms a yitreous mass on cooling. It begins to deoompoie
between 200^ and 2 1 0° C. It is yei7sparin||1y soluble in cold water, Imt dissolyearadilj
in boiling water, which deposits it on cooling in the form of a jelly. It ia vMk
in boiling alcohol and insoluble in ether. According to PI ant a and Wallace (Ann.
Ch. Pharm. Ixxiy. 262) it contains C'H'O'*. Its solution in boiling water produces
a blood-red colour witii ferrous salts : this reaction is extremely d^cate, samcing to
indicate the smallest traces of apiin. The aqueous solution, after boiling for a long
time, no longer gelatinises on cooling, but deposits nearly wMte flakes, which appear
to consist (^ C^H'O^.HK). When apiin is boiled with dilute salphnrie or by*
drochloric acid, the liquor deposits on cooling, white flakes, which appear to eootain
C^H'^0* that is to say, apiin mintts 4 atoms of water. Apiin is disaolred \n
alkalis and reprecipitated in its original state by adds. When boiled vith su-
phuric acid and peroxide of manganese, it yields carbonic, acetic, and formic acids.

AKOS TUBBKOBA or Glycine apiot (JL) — A l^^uminous plant from North
America, the roots of which haye been proijoseid as a substitute for the potato, and the
young seeds for peas. The roots are eaten in Yirginia, and are said to have been used
oy the aborigines of the country. Pay en (Compt. rend, xxyiii. 189) giyes the foUor*
ing statement of the composition of the roots, compared with that of the yariety of

potato called ^^ro^ Ratine ;

Aptoe. Fouto.

Nitrogenous matter 4*6 1*7

Fatty matter .0*8 0*1

Starch, sugar, pectin, &c 33*55 21*2

Cellulose and epidermis . .1*3 1*6

Inorganic matter 2*26 1*1

Water 67*8 744

APXRXV or AVTSZV« An alkaline substance said to be contained in the nat
of Cooo» nucifera and Coco% lapidea, (Bizio, J. Chim. tdAL 1883, 496.)

See Mangakbse-aluk.

A name inappropriately giyen to a kind of gnnite, eonsistiiig dnefly
of a flne-ground mixture of quartz and felspar with only a trace of mica.

See Gabnbt. — AFOO&VCZO AOZB. See Gi.vcio Acn>.

CC AOm. See Hukio Acn>.

AOZBf CH'NO^ — A nitrogenous acid obtained by the de>
composition of cotamine; first prepared by Wo hi er (Ann. Ch. Pharm. i. 24), aito-
wards more fully examined by Anderson (Edinb. Phil. Trans, xxiii. 347 ; Chem. Soc.
Qu. J. y. 267).

---Preparation. — 1. Cotamine is dissolyed in nitric acid diluted with twice its Tdnme
of wat^r ; strong nitric acid is added; and the whole is heated to boilings whereopan
abundance of red yapours are eyolyed. As soon as a small portion of the solution, on
being mixed with alcohol and ether, quickly deposits crystius (if no czTstsIs tpp^r
the heating must be continued), the whole of the solution is treated in the same vay,
and the crystals which are deposited after 24 hours, are filtered off and purified by
boiling their solution which animal charcoal, and reczystallising. A great exoesB of
nitric add hinders the precipitation of the apophyUie acid (Anderson).—! ^
decomposing chloroplatinate of cotamine with sulphuretted hydzooen, filtering off
the platinum and eyaporating the filtrate with hydrate of bajium, apophyllate of bannm
was found in the residue ; and after extracting the cotamine with alcohol, and boiHic
the residue with dilute sulphuric acid, a yellow solution was obtained which deposited
crystals of apophylUc acid after the lapse of seyeral weeks. (Wohler.J

ApophyUie acid crystallises from a boiling saturated solution on cooling, in isther
long anhydrous prisms, which do not effloresce when heated. It reddens litmus sboBg^T
and has a weak acid taste (Wohler). Melts at 206^ C, and solidifies on ooolin&
into a crystalline mass. (Anderson.)

APOPHTLLITE. 351

ft. ^draUeT i^fophyUie acid, C*H'NO^HK), cipmtallifles from a Mtarated and not
boiling aolntion, in ooJonrleea^ very shaip rhombio octahedrons the fonn of which
mpprou^MB to thiat of a aqnare-hased octahedron. Angles of the base about 88^ and
939; of the lateral edges, abont lOe^' 28', 105° 24', and 190°. The crystals deare very
readily in a direction parallel to the base, forming faces of pearly lustre, like the
czystals of apophyllite (hence the name). These give off their water, amounting to
abont 9 per cent, at a temperature much below 100° G. (Wohler.)

Ajueaus Apopl^Uic JcitL — Apophyllic acid dissolves slowly and with ^;reat difficulty
in oold water. It is soluble in sulphuric acid (Anderson) ; insoluble in alcohol and
ether.

When heated, it melts, chars, and evolyes an oily, strongly alkaline liquid, which
smeDs like chinoline (Wohler). By distillation it yields a neutral oil, as well as a base,
which does not become coloured when treated with chloride of lime (Anderson). —
2l Nitric add converts it into oxalic acid (Anderson).

ApopKyllates, — ^Nearly all the apophyllates are soluble in water.

ApopJ^UaU ofAttwwmum fonns small prismatic needles. It is readily soluble in

ApophyUaU of Barium is obtained in nodular ciystals by digesting the acid with
car^nate of barium and adding alcohol to the solution. (Anderson.)
ApopkyUaU of Ammonium does not precipitate lead-salts, ( W o h 1 er. )
Apopkjfiiate of Stiver, (>il*AgNO*, is obtained by digesting apophyllic acid with
moist caibonate of silver and precipitating the solution with alcohol and ether. It
forms a crystalline powder, which bums slowly when heated, leaving a residue of
metallic silver. It is easily soluble in water, insoluble in alcohol and ether (Ander-
son). On mixing a solution of apophyllate of ammonium with nitrate of silver,
a double salt, consisting of apophyllate and nitrate of silver, CH'AgNO^.NO'Ag, is
deposited after a while in small ciystalline stars, which soon increase to secmtic
nonpe of fine needles. The salt explodes violently when heated, like oxalate of silver.
It is slij^tly soluble in water.

Ichthfophthalmite, Fish-eye stone, — A silicate of calcium and
potaaeinm, also containing fluorine, whidi is found both massive and crystallised.
The ciystals belong to the dimetric system. The most usual form is ao P oo . P, also
with OP. Cleavage perfbct^ parallel to OP, imperfect parallel to oo P ao . The massive
variety has a laimnated stmctore. Specific gravity 2*3 to 2*4. Hardness about that
of apatite, or eenendly rather less. The finest varieties are transparent and colour-
less, or sometimes tinged with rose colour ; translucent ciystalB are also found, or
opaque in the mass, transluoent onlv at the edges, and white, reddish-white, or flesh-
eoloored. Extnnal Instre splendent and peculiar; internal lustre glistening and
peariy. The transparent crystals exhibit, according to Brewster, a peculiar oi>tical
character, which shows that each individual crystal is an ag^resate of several pieces
symmetrically arranged. In some places (especially at Aussig m Bohemia) a variety
eaUed aibin is found, consisting of opaque crystals of peculiar form. Apophyllite, heated
before the blowpipe, exfoliates Thence its name, from &iro^vXA(((cr), then froths, and
melts into an opaque bead. It is easily decomposed by strong hydrochloric acid, with
separation of gelatinous silica. The filtrate, supersaturated with ammonia, yields
» precipitate of fluoride of calcium.

The composition of apophyllite, as determined by analysis, is as follows : —

Benellus. Stromeyer. G. Omelfn.

Silica 5213

Potash .... 5*27
Lime (including CaF) . . 25'53
Water 16-20

99-13 99*30 100*73

From these results, L. Gmelin (Handb. iii 394) deduces the formula K0.2SiC^
'¥9(CaO.2&O^+Ca0.aiO^+CaF+ieS0*, or 15SiO«.7Ca*O.K«0 + 2CaF + 16H*0.t
Simpler formnlsd may be obtained, if we suppose the fluorine to take the place of
part of the oxygen in equivalent proportion. Bexzelius gives the formula JtO.2 jSiO*
* 9{CaOM(^) I + 16J7d, whldi, if M denote a monatomic radicle, may be reduced to
10SiO'.03fO.16£rO. Tile analytical results may, however, be equally well represented
by the general formula 10§^\0',SR0.16HO ; and, assuming that SHO may replace
IMO (see IsoMOKPBisfM, Polticbbic), this formula may be reduced to 9j(iO'.13AfO},
or 27SiO«.26M*0.

•JV»H;0=8. t SiaSB; OalO. { ^i « 31*6} 0»S.

61*86

63-90

6-31

6-13

26-22

26-00

16*91

16-70

852 APOBETIN — ARABIN.

A resin obtained by dissolTing in alcohol that portion of tbe
alcoholic extract of rhubarb which is insoluble in water, precipitating by ether, and
a^ain treating the precipitate with alcohol, the aporetin then remaining undianlTed
(Schlossberger and Dopping, Ann. Ch. Fhann. i. 219). Treated vith ooncen-
trated nitric acid, it yields a yellow subetance, which appears to be chiysammie add,
together with oxalic acid and an acid which produces a brown-red ooloariog with
alkalis. (De la Bue and Miiller, Chem. Soc ftu. J. x. 298.)

V. Kaaoxyd, — A product of the putre&daon of the ao-cdied
protein-compounds, discovered by Proust, but since shown by Mulder and othen to be
merely impure leucine.

APOTRSII* A term applied by Berzelius to the insoluble brown deposit vfaidi
forms in vegetable extracts when exposed to the air. It is not a definite compoimd,
but a mixture of several substances in a state of decomposition, and therefore of reiy
variable constitution. (See Deoat and FuTBEFAcnoir.)

JkmKBS* A comparison of various sorts of apples and pears, with regard to
specific gravity and amount of water and add in the juice, has been made bySchnlze
(J. pr. Chem. Ixii. 207). The results vary greatly according to season, dimate, and
soil; but the general conclusions are as follows: — The spe^c gravity of the freak
fruit varies from 0*72 to 0*91. The fruits contain between 13 and 21 per cent of diy
substance, of specific gravity above 1 *4. The juice of 20 kinds of apples had a apedfie
gravity between 1*020 and 1*027 ; in two varieties only, it was found to be betveen
1*033 and 1*037. The acid in the juice, estimated as tartaric add, amounted to
between 0*48 and 1*13 per cent. In Wurtemberg. the spedfio gravity of the juice of
apples and pears rises in warm seasons above 1*080, and even approaches 1*090, the
amount of free add, estimated as tartaric add, varying from 0*4 to 1*2 per cent, and
iheX of sugar from 4 to 10 per cent

AFVUi«-mB« {Pyrus 3fa/tw.)— The ash of the branch of an apple-tiee eon-
tained, after deducting ue carbonic acid, in 100 pts. : 19*24 potash ; 0*45 aodi;
63*60 lime; 7*46 magnesia; 2*41 ferric phosphate; 4*16 phosphoric add; 0*46 chlo-
ride of sodium ; 0*93 sulphuric add; and 1*31 silica. (Fresenius, Kandw. d. Chem.
2*- Aufl. i. 171.)

APPUl-OSL. MaloUe. — A yellowish oil form'ed in apples when kept^ It is
L'ghter than water, has a yellowish-grey colour, a sharp ana harsh taste, boils at
190^0., and distils completely; bums with a slightly fuliginous flame; dissolTes
sparinffly in water, but readily in alcohol and ether. Contains 64*15 per cent carbon,
20-65hydrogen, and 16*20 oxygen. Forms a crystalline compound with hydrochloiie
acid, but is decomposed by chlorine. (Handw. d. Chem. 2** Aofl. i 172.)

APV&B-OI& (AXTZRCZAA). This name is given to a solution of valerate
of amyl in 6 or 7 parts of alcohol, which has the smell of apples, and is used as a
perfume. (Hofmann, Ann. Ch. Pharm. Ixxxi 87.)

See ApmiN.

8iberite^ Rubdlite, Red tourmaline. See Tottbmalimb.

AQVA VOXTBi. This name is given to a weak and impure nitric add commonly
used in the arts. It is distinguished bythe terms double and sin^le^ the single haTing
only half the strength of the other. The artists who use these adds caU the more
concentrated add, which is much stronger even than the double aqua fords, spirit of
nitre, (See Nmtio Acid.)

AQVAMAMZira. See Bebtl.

AQVA-4MB01JL or ft'BOZB. A mixture of nitric and hydrochloric acid, k
called from its property of dissolving the noble metals, gold and platinom. (See
NrrBO-HTDBOCHLOluc Acid).

AQVA-VXTJB. Ardent spirit of the first distillation has been distinguished by
this name in commerce. The oistillers of malt and molasses spirits call it kw vmm.

AQUXliA. AXaUL, mTZOATAt COS&aBTZS, BODRCUBIX. An oldnan?
for subchloride of mercury ; also mercuriue dulcis, or mild muriate o/ mercury.

AMAMKO (CroiC). This gum exudes spontaneously from several species of
acacia (Aeacia vera^ A, arabica) &c It was formerly imported into Europe trm
Egypt and Arabia^ but is now obtained chiefly from Senegal. The coarser and
cheaper varieties mostly used by calico printers and other manufacturers are knon
by the name of gurnHMuegaL (See Gum.)

The prindpal constituent of gum arable, in which, according to

ARACHIDIC ACID — ABACHIS. 353

Keubaner (Ann. Ch. Pharm. m. 105), it exists in combination with lime, magnesia
and potaah. Bj treating the ^um with hydrochloric acid and alcohol, these compounds
are deoomposed, and the aiabin is separated in the form of a gum, which exhibits the
propcrtiea of an acid. In the moist state, it dissolves readily in cold water, forming a
gummy solution, firom which it is precipitated by alcohol. After drying at 100° C. it no
longer diasolyea in cold water, but merely swells up to a gelatinous mass. Dried at
100*^0. it has the conqioaition CH'K)", ^ of the hydrogen being replaceable by

no AOn. C-H-O' - C-H-OJo.-IW,.cedbythe«,poniflcation

of oil of earth-nut (Arackis kypogaa). The oil is saponified with soda ; the mixture of
£itty acidB sniarated from the soap by hydrochloric acid, is macerated with five or six
times its bu& of cold alcohol to remove the volatile acids ; the insoluble portions
are preased and dissolved in alcohol; and the solution, heated nearly to the boiling
point, is mixed with such a <|uantity of acetic acid, that on adding an excess of alco-
holic acetate of lead, no precipitation fakes place while the liquid remains hot. The
cr^Btali which separate after tne liquid has remained in the cold for forty-eight hours,
are separated from the liquid and mixed with alcohol and hydrochloric acid ; the
TCsnlting ethezB of the &tty acids, after being filtered off from the chloride of lead
and freed from part of the ah^hol by evaporation, are decomposed by boiling with soda-ley
after the alcohol has been completely expelled ; the resulting soda-soap is decomposed
faj hydrochloric acid : and the mixture of &tty acids thus separated, is again dissolved
in aKv>h^i, and fractionally precipitated with alcoholic acetate of magnesium. The
portions first precipitated contain arachidic acid, which after several crystallisations is
obtained pore.

Arachidic acid crystallises in venr small shining scales ; melts at 75° C, and solidifies
again at 73°*5, forming a radiated mass, which after a while assumes the appearance
of porcelain. It is but very slightly soluble in cold alcohol of ordinary strength, but
^flsolves easily in boiling absolute alcohol and in ether. (A. Go s am an n, Ann. Ch.
Pharm. Tmnrix. 1.)

The add ia monobasic, belonging in fiict to the series of fatty acids, C"H^ - 'O^H.
The ammonium, potaasium, ana sodium salts, are soluble in water, the rest insoluble
or mtaing^j soluble in water, but soluble in boiling alcohoL The silver-salt,
CJBPOVAg; is a white precipitate which separates from boiling alcohol in slightly
Insfetoiis pnsms, not alt^ed hj exposure to light. (Gossmann andScheven, Ann.
Ch. Pharm. xeviL 257.)

AraekidaU of Ethyl, C*H*0',OH*, obtaiDed by passing hydrochloric add gas
through an alcoholic solution of the acid at 80° or 90° C, is a crystalline, slightly
tenadona masa^ which melts at 52*5°, and solidifies at 51°. (Gossmann.)

Araekamide, (C*H*O^N*)N, is obtained by leaving earth-nut oil for several
weeks in contact with ammonia. It forms prisms grouped in stars, insoluble in water,
dissolving with tolerable frdlity in boiling alcohol, melting at 98° or 99° G. When
luaed wiu hydrate of potassium, it gives off ammonia.

Arachin, or Arackidate of Glyceryl^ is obtained by heating equal parts of arachidic
add and syrupy glycerin to 210° C. in a sealed tube. It is a lustrous fatty substance
which melts at 70° C., and solidifies in a crystalline mass when slowly cooled. It dis-
soItbs sparingly in alcohol of 90 per cent, more freely in absolute alcohol, and still
Boore in ether. It gave by analysis 76'2 per cent carbon, and 12*6 hydrogen ; whereas
the formula aftriarackidate of glyceryl, C^K)«.(C»H«n)J», requires 7762 C and 126 H
(Gossmann and Scheven). Berthelot (Ann. Ch. Phys. [3] xlvii. 355) regards the
product obtained by Gossmann and Scheven as a mixture of diarachin with free
arachidic add. He prepares the pure neutral arachins by melting in a flask the crude
poodnct obtained by heating glycerin with arachidic acid, then adding slaked lime to
nentraliae the free adds, digesting with ether for fifteen minutes, and afterwards
boiling with ether, which dissolves the neutral fat and leaves the lime-soap undissolved.
The ethereal solution when evaporated, leaves the neutral fat, whidi, if quite free
from adhering fiitty adds, should form with boiling alcohol a solution which does not
redden litmus. In this manner BeaHielot has obtained the three neutral arachins,
eorresponding to the acetins, viz. monoaracHn^ CH^O*.C*H'*O.H', diaraohin,
C^»O».(C»H"0)*.H, and triarachin, C»H«0».(C» H"0)«.

MMAiOMEB BTVOOJBAa Earth-nut — A leguminous creeping plant, indi-
gBDOus to India and the coasts of South Africa and South America, and cultivated in
North America and in the south of Europe. The flower-bearing stems exhibit, as
soon as the fruit begins to form, a tendency to bury themselves in the soil, those
whidi remain above ground bearing little or no fruit Hence in the cultivation of the
plant, the main point to bo attended to is to cover up with earth all the flower-bearing

Vol. L a a

354 AR^CHYL— ARBUTIN.

stenifl ae soon as the flowers iade. The seeds contain about half their irei|^i of hi
cnl, earih^mti cU {hmie d^arachide, hmle de tristaeke de terre, Erdnuu-cl), vhic^ is
extracted from them by pressure. The oola-piessed oil is nearly ookariesB, hss a
faint agreeable odour, and may be used for culinary pnzposes instead of olive mi,
only it becomes rancid more qniddy. The warm-pressed oQ is co&oured, and has
a disagreeable taste and smelL The cold-pressed oil has a density of 0*916 at 6Q9 Cj;
and soUdifles at — 3^ C. When it is exposed for some time to a temperature of -i- 3^.
a solid fat resembling stearin separates from it^ It dissolyes bnt sparingly in alcGdiol,
more readily in ether and essential oilsL It saponifies slowly when boiled with caustic
soda, yielding a hard, white, odomrless soap, wnich is mannfkctnred in France, and to
some extent also in Germany. This soap» when decomposed by the stranger adds,
yields two pecoliar fat-adds. Tie. arachidic add, C^H^O', belonging to the series
OHM)', and hypogsdc addi, C*'H"K>^ belonging to the oldc add, series, 0*H^-*0'
besides a large quantity of palmitie add. The oil consists therefore of araohin, hypo-
gsein, and pidmitin.

CPH^O. — ^The hypothetical radide of arachidic add.
See Htdboiibtsk.

(firom ipaios, rare and ^^Jfos, goest). — A Tariety of Tanadate of
lead, in which a considerable portion of the lead is replaced by sine, giving the
formula yO*(Pb ; Zn)*. Yon Kobell found 48*7 per cent oxide of lead, and 16*3 per
cent, oxide of zinc. The mineral, which was formerly nustaken for chromate of lead,
is found in defts of a bed of sandstone, at Dahn in the Bheinp^aJiz. It forms
botryoidal oystalline masses, exhibiting on the fracture tzaces of raoUating stmctue.
Ck>lour, dark red, inclining to brown ; slightly translucent Streak, lig^t yellow.
Hardness 3. Hdts quickly before the blowpipe, with intumescenosL The powder
is easUy decomposed by heating with hydrochloric add. (See Kobell, J. pt, Chem.
ii. 496.)

AMBOJwmikmllMmtk MMBTMrn This resin is the produce of the Canarium aUmm,

a tree belonging to the natural order TWebinihaceeBf which grows in the FhUfiplne
Islands ; the resin, whidi is used by the natives for caulking their canoes, is greyish
yellow, soft, glutinous, and has a strong agreeable odour. According to Bon a st re
(J. Phann. x. 199) it contains in 100 pts. 61*29 pts. of resin, vexy somble in alcohol ;
26-00 of resin, sparingly soluble in alcohol ; 6*25 essential oil ; 0*62 free add ; 0*52
bitter extractive matter; 6*42 woody and earthy impurities. Baup (Ann. Ch. Phys.
[3] xxxi. 108) has obtained from it four different ctystallisable substances, via. —

Amyrin, — Insoluble in water, sparingly soluble in cold, easily in hot alcohol, easQy
also in ether, whence it crystallises in satiny fibres, having a strong lustre. Melts at
174^ C. Contains, accordmg to Dumas, 85*3 per cent earison and 11*7 hydrogen, and
is perhaps identicsl with crystallised demi-resin.

Brddin, — Crystallises in transparent rhomboidal prisms of 102^ and 78^, tenninated
by four sided pyramids. Dissolves in 260 pts. of water at 10^ 0. much more abon-
dantly in hot water; easily in alcohol, sparingly in ether,. The crystals become
opaque at a genUe heat, mdt at a temperature a little above that of boiling water,
and sublime undecomposcd at a higher temperature, yielding a alightiy pongont
vapour which excites coughing.

Brein, — Insoluble in water, soluble in 70 pts. of 86 per cent alcohol at 20^0.; more
soluble in absolute alcohol ; very soluble in ether. When slowly crystallised from an
alcoholic solution, it forms transparent rhomboidal prisms of about 70^ and 110^,
terminated by dihedral summits whose fosses meet at about 80^. By rapid codii^
adcolar crystals are formed. Melts at 187^ C. Neutral.

Bryoidin. — Crystallises from water in white siU^ filaments. Hss a slightly latter
and burning taste, and when heated gives off a vapour which exdtes oou^ung. Mdts
at 136^ C, begins to volatilise before mdting, and sublimes in colourless needles^ ^p^r.
ingly soluble in cold, much more in hot water, very easily in alcohol and ether. %ie
aqueous solution is neutral to test-paper, but predpitates acetate and snbaoetata
of lead.

names are applied to the arborescent metallic predpitates formed by the cjow reduction
of one metal m solution by another, e.ff. lead hy sine.

A crystalline substance discovered bjr Kawalier (Ana. CSl PIii
Ittti. 241 ; Ixxxiv. 366) in the leaves of the red bear-berry (Jf€ta$Ui^piyio9 D^m
Ursi), The aqueous innision of the leaves forms with neutral acetate of lead a
vellow precipitate containing gallic acid; the filtered liquid freed from exoeaa of
lead by hydrosulphuric acid, and then concentrated to uie consistence of a syrvp,
depodts crystals of arbutin, which may be purified by pressurs, solution in boiliiig

ARC ANITK— ARCHIL. 355

vttter, and trertment witli animal cfaanoal. Arbutin forma gnmpB of colonrless
bitter oystaLs, which an solable in water, alcohol, and ether; the solutions are neutral
to test-paper.

When heated it melts and gives off water of crytallisation. Its aqueoos sdution
does not form any precipitate with ferric salts, or with acetate or subacetate of lead.

A Bofaition of aitrntin mixed with emnlsin (extracted from sweet-almonds), and left
for some days in a warm place, acquires a reddish tint, and leayes when evaporated
over the water-bath, a rradish brown residue, from which ether extracts arctuvin,
and learos a quanti^ of insoluble saoefaarine matters. Ihia decomposition of arbutin
is represented, according to Eawalier, by l^e equation :

C«*H«0»» = C»H»0' + C»«H«*0"
Arbutin. Aretavia. Olucote.

but aooordiog to Gkrhardt, by the equation

Arbutin. Arctnvin. Glucose.

Kawalier^s analysis of arbutin gives 62*4 per cent carbon, and 6*1 hydrogen. His
formula requires 624 C and 60 H ; Gerhaidt's, 64*2 C and 5'6 H. (Gerhardt, Traits,
iv. 266.)

See GiAfiBBiTB.

, or OMBMObLMb a fine purple dye obtained from various
species of Hchen. There are two varieties, called in France orseiUe de mer and orseiile
de. terre. The former is obtained from various lichens of the genus SoceUa growing on
the rodnr coasts of the Azores, the Canary and Cape de Verd isles, also of the Cape
of Good Hope, Madeira, Corsica, Sardinia, &c ; the latter from Variotaria orcina^ from
Auva^gne, Parioiaria dealbata, from the Pyrenees, Lecanora tartareOj frx)m Sweden, and
othen. None of these lichens contain the colouring matter ready formed, but they
contain certain colourless acids, erythric, lecanorio acid^ &c., which are susceptible
of transformation into a colourless neutral body called orcin (g.v.); and this, when
acted upon by the air and by ammonia, changes into a purple substance called
orcein^ which is the colouring principle of archiL

To prepare archil, the lichens, alter being ground between stones, are rubbed up to
a thin paste with water and puftrefied urine or carbonate of ammonium, and left to
fbnnent, with addition of quick lime, a small quantity of alum or arsenious acid being
sometimes added, perfaapa, to prevent the fermentation from going too far. In a week,
a violet colour is obtained, which beeomes brighter in a few days longer. When
carbonate of potassium or sodium is added to the lichens as well as ammonia, a
different change takes place, and a blue colouring matter called LitmuB is obtained,
which is never producea by the action of ammonia alone. (See Lmcus.)

Dyen rarely em^oyarchil by itself on account of its dcamess, and the perishable-
nes6 fd its beauty. The chief use they make of it is for giving a bloom to other
colours, as pinks, &c. This is effected by passing the dyed doth or silk through hot
water slightly impregnated with the archil. The bloom thus communicated soon
decays upon exposure to the air. The addition of a little solution of tin gives a
durable aye, the colour of the archil being at the same time changed toward a scarlet,
and becoming more permanent in proportion as it recedes the more from the natural
tint

Prepared archil very readily gives out its colour to water and to alcohol ; it is the
sabataoce principally made use of for colouring the spirits of thermometers. As
exposure to the air destroys its colour upon doth, so does the exclusion of the
air produce a like effect in these hermeticBlIy sealed tubes, the spirits of large ther-
mometers becoming in a few years colourless. The Abb6 Nollet observes (in the
Memoirs of the Academic des Sdenees for the year 1742) that the colourless spirit,
upon breaking the tube, soon resumes its colour, and this for a number of times succes-
sivdy ; that a watery tincture of archil, indudcd in the tubes of thermometers, lost its
oolour in three days ; and that in an open deep yessel it became colourless at the
bottom, while the upper retained its colour.

A solution of archil in water, applied on cold marble, stains it of a beautiful violet
or puiplish-blue colour, for more aurable than the colour which it communicates to
other bodies. M. dn Fay says he has seen pieces of marble stained with it, which in
two yean had suffered no sensible change. It sinks deep into the marble, sometimes
above an inch, and at the same time spreads upon the sur&ce, unless the edges be
bounded 1^ wax or some similar substance. It seems to make the marble somewhat
more brittle.

There is a considerable consumption of a variety of archil manufactured in Glasgow,
it is much esteemed, and sold by the name of cudbear. It affords very beautiful

▲ ▲ 2

356 ARCTIZITE— ARGTRITES.

colours on silks, of varions shades, fiom pink and crimson to a bright msnrinehloe^
which are said to be yeiypennanent — V. (See Ur^sDicHanaryofj&ttf Manufaetmttf
and Mines, i 175.)

See WsBinaim.

AMCTOBTAWKWlbOm WA UBSZ. The bear-beny.—An ericaeeoas pbnt
which grows wild in the mountainous parts of England and Scotland, and in the north of
Earoi>e. It possesses strongly astringent properties. The leaves boiled with water yield
a liquid which contains tannic add and a large quantity of gallic add, and may therefore
be used for making ink. The same decoction contains, according to Kawalier, (Ann.
Ch. Pharm. Ixxz. 356) arbutin, sugar, ericolin, a resinous substance, wax, fit, ehl«o-
phyll, Tegetable fibre, and a body resembling emulsin, which has the power of indocmg
the transformation of arbutin. The resin may be separated from the mother-liquor of
the preparation of arbutin, by heating it with hydrochloric add. It is brittle^ neadj

blade, dark brown after trituration, and is said to consist of C"fl**0 ', perhaps rather
C**H"0*. Besides these substances, H. Trommsdorff ^Chem. Gas. 1863, p. 61) aho
found in the leares another oystallisable substance whiw could be extzacted l^cthei^
viz. ursane,

ABOTU Via is deposited by evaporating the ethereal solution of the btovn
residue obtained by the decomposition of arbutin (n. 35i), in colourlesa crystak,
which are purified by recrystallisation from water, alconol, and ether, with the aid ol
animal charcoal It forms long prisms, which are bitter, fiisible, and may be Boblimed
when cautiously heated. It contains, according to Kawalier*s analysis, 64*4 C and
5-6 H. The formula C'*H^' requires 64*5 G and 5*4 H. Gerhardfa fonnda,
C*'H**0\ requires 65 '4 C and 5*4 H. If ses(^uichloride of iron be added, drop bjdroft
to an aqueous solution of arctuvin, the mixture assumes a bluish tint^ grtdaal^
changing to green. With a solution of subacetate of lead containing a little ammoDia,
arctuvin forms a white precipitate, which soon tunis brown, i&ctuvin moiatened
with ammonia and exposed to the air gradually forms a black substance, wbkh
Kawalier calls aretuvein ; it contains 35*9 C, 3*0H, 12*5 N, and 48*6 0. (Gerhardt,
Traits iv. 266.)

A3RBCA vmniff the fruit of the areca palm (Jreca cateeku, L.), contain, u
their chief constituents, catechu, a variety of tannic add, and gallic add, together
with acetate of ammonium, £its, oil, ^um, nitrogenous substances, and a dje called
areca-red, which is of a brown colour, without taste or smell, insoluble in cold water and
in ether, soluble in boiling water and alkaline liquids, whence it may be predpLtated
by adds. Boiled with nitric add, it yields oxalic add. (Horin, J. Pharm. riii. 449.)

JkXamAXXTB. See Epidotb.

JkMMTHikWM, a name eiven by Laurent to a product of the decompositaon of
chloride of cacodyl by alcohouo potash. (See Absbmio-badicubs, OBOAMia)

ABVWVBBOVXTB. A ferruginous variety of hornblende. Cdoor UacL
Cleavage-faces much, more brilliant than those of hornblende, which seratchea it
Specific gravity 3*44. Melts even in the flame of a candle ; boils up stron|;ly before
the blowpipe, and yields a black magnetic globule. Not soluble in adds or in caostie
potash. Its composition may be represented by the general formula Si*B£"0^ »
5M'0.6SiO*. A spedmen from Greenland, analysed by Kobell (J. pr. Chem. ziiL 3)
yidded results agreeing nearly with the formula (15Fe*O.4NaK).Ca*O).24Si0*.

SiO« FeK) Na«0 Ca«0 Mg«0 Mn«0 A1*0« Q
Analysis . . 49*27 36*12 8*00 1*50 0*42 0*62 2*00 0*24 » Mi7.
Calculation . . 52-33 36-93 8-77 1*97 . . . . . . . . - 100"00.

ABCIAXi or ARCMZi. The commerdal name of crude tartar in the state in
which it is taken from the inside of wine-casks.

AXOBirTAM. Syn. of Nickd-silver or German silver. See Nigkhl

ft WmiyirTAaiMOJi a U ml a metallic ammonium-radide (p. 198), ooDtatning
1 at. silver in place of hydrogen. Its oxide (NH'Ag)H) is commonly called /WmM*
itiff sUver, (See Silver.)

ilK0BH TUI B. A schiefer-spar mixed with silica, found at Southampton and
Williamsburgh, in Massachussets. (See Caixspab.)

ARCUDTTZVa TIM^WMUM O V AMTAMOVT* An old name of tetmzide of
antimony, or antimonate of antimony (p. 324).

AMmrxm or AXATXOSB. Syn. of Silvbb-olaiio&

ABCNCUbAOaomi MAMTWU See ALtTVDTA and Clat.

See Lbad-oxidii. — ABiCnHMMIWi See SiLYBB-OLAiici.

ARICINE — ARNICA- 357

(?*B*'lPO* (CinehotKitin^, Cuscofdne, Quinomn€).—Ajk aUcaloid, dis-
eorered in white dnchona bark from Aiica^ by Pelletier and Corriol (J. Phamu
[2] XT. 575). Manzini (J. Pharm. ^3] iL 96) afterwards, found in a fibrous white
dnehona fit>m Jaen, an alkaloid which he called etnchoffatine, but which has been
shown by Winckler (Buchner^s Bif^ert d. Pharm. [2] zzzi 294; zlii^26 and 231 ;
•6tdL ^3] i. 11) to be identical with aridne.

Ancine is extracted from the cinchona bark in the same manner as quinine {q, t;.),
Ti&. hj boiling the bark with acidulated water, treating the liquor with lime, and
digp^ing the Hme-precipitato in alcohol. The solution, filtered at the boiling heat,
jveldB a Tezy dark^ooloured Hqaid, which, after a while, deposits the greater part of
the aiicine in dyBtals. An additional quantity may be obtained from the mother-
liquor by expelling the alcohol by distillation, treating the residue with a slight excess
of hydrochloric acid, separating the greater part of tiie colouring matter by means of
a saturated solution of eonmion salt, then predj^itatin^ the aricme by ammonia, dis-
solTing the precipitete in alcohol, decolorising with animal charcoal, and crystallising.

Ancine fSnrms white prismatic crystals, more elongated than those of cmchonine ;
they are inodorous, and haTO a bitter taste, which, however, does not show itself for
some time, on account of the sparing solubililgr of the alkaloid. It dissolves easily in
alcohol, on>eeialIy when warm, less readib^in ether. The solution blues reddened
litmus, and turns syrup of violets green. The crystals, which are anhydrous, melt at
188^ 0., fijnmng a brownish liquid, which blackens at a higher temperature, yielding
fetid empyreumadc products. Aricine dissolves with decomposition in strong nitric
add, forming a deep green solution : this is a verf characteristic reaction.

The salts of aricine are, for the most part, easily soluble and crystallisable. Thej
are obtained by dissolving aridne in dilute acids; the solutions are predpitated
^ alkalis. The acid sulphate, C^H^^O^SO^H', crystallises in flattened needles
(FeDetier), which are anhydrous (Manzini). The neutral sulphate does not czys-
taDiae from solution in water, but forms a gelatinous mass, which dries up to a
horny substance (Pelletier, Ann. Ch. Phys. \%'\ li. 185), The ptatinum^saltf
C*'^'KK)\HCLPtCP, is soluble in alcohol, and is deposited from the solution by
spontaneous evaporation in crystalline plates.

AXnVO&OCBZA. OfcWIIff ATlTJJi. Birthwort. — The root of this plants
wfaieh has a shsErp bitter taste, and was formerl^r much used in medicine^ has been ex-
amined by several chemiste : bitt the resulte hitherto obtained are not very definite.
When <^iiisil^ with water, it yields about 0*004 of an essential oil of spedfio gravity
0*903, and said by Walz to be composed of C"H*0'. A volatile add, aristolochic acid also
passes oivcsr, the barium-salt of which contains, according to Walz, CHfBa'O'. Erom
the aqueous eztiact of the root, Walz obtained an impure bitter compound, clematis
dene^ <>M*0*, which is perhaps identical with the aristolochine obtained by Chevalier
from AHstolochia serpentaria. Frickinger obteined from the root a bitter uncrys-
tallisable body, and also a yellow c^stalline substance, aristolochia'yelloWf perhaps
identical with aristolochine or dematidine. The root also conteins a resin soluble m
alrohol and ether. The inorganic constituente of the root are : potash 10*3, soda 4 '2,
efalaride of sodium 8*6, lime 9*1, magnesia 3*0, phosphoric add (PO*) 14*2, sulphuric
add (SO*) 1*4, sesquioxide of iron 3*1, silica 4*5, sand, charcoal, and carbonic add
4*36. ^Winekler, Jahrb. pr. Pharm. xix. 71 ; Frickinger, Buchn. Expert. [3] vii.
1 ; Walz, Jahrb. pr. Pharm. xziv. 65 ; xxvi 65.)

ASiaVO&OCBTA IIMJPJUfTABTft i The root of this plant, which had
once a great repute in medidne, is now nearly fallen into disuse. Chevalier stetes
that the active prindple of it is a vellow bitter substance, whidi he calls aristolochine.
The root also contains an essential oil, resins, gum, &c

See Bbooxitb.

See As84.

■• A felspathic sandstone, often having a porphvritic structure, found

sear Poivin in the Vosges. According to Delesse (Jurch. d. Sc Phys. et Nat. de
Qenhre viL 177) it has been metamorphosed in the humid way, by taking up the
constitoento of felspar and hyalite^ and gradually transformed into the Vosges sand-
stone above and granite below.

MMMMMZBM STUMS. Lapis ArmemuSy Armenite. — ^An old name for a mixture
of euthy azure oopper and limestone, sometimes mixed with copper or iron pyrites ;
or ibr quartz eoloiffed blue by azure copper.

ABVlCXAr OSb OV. Both the rooto and the flowers of Arnica montana contain
volatile oils. The oil is obtained from, the flowers has a yeUow to brownish green
colour, dissolves in 100 pts. of alcohol, of specific gravity 0*85, becoming turbid and
floecnlent, and in 10 to 60 pta of absolute alcohol, and forms a solid resin when

AA 3

358 ARNICINE— AREAGONITE.

treated with nitric acid. The oU from the zoots has a speeific gprsTity of (hM to (W,
and a wine- jellow to brownish yellow colovr ; disscdyes in 2 pts. of alcc^ of ipeofie
graTity 0*85, and in all proportions of absolute akx>hol» and becomes Tisdd when
treated with nitric acid. Both oils have a slight acid z«actioB. (Zeller, "StodiMi
iiber atherisdie Oele," I^oidaa, 1860.)

A bitter principle in the flowers of the Armea fnonUtna^

SeeSpHBNB.

A silver amalgam from the mines of Arqaeros in CsqumbOt Chili.

iCMm A spirit obtained by fermenting incision of rice. In Cejlon it is ob-
tained from coooa-nnt toddy (palm wine).

AXXAOOXXTB. Bhombio Carbonate of Lime. — ^Tfais minem], which derifes ill
name from the locality where it was first found, yiz. in Airagon, oocors flometimcs in
regular crystals, sometimes in fibrous or radiated crystalline massesi sometimes as a
deposit or sinter from hot calcareous springs.

The crystals belong to the dimetric^ rhombic, or right prismatic system, and are
derived from a right rhombic prism with angles of 116^ 16' and 63° 44', exhibiting
two directions of distinct deavase parallel to the fkces of this prism. Twin-<a;8tah
also frequently occur, likewise lobular, reniform, and botryoloal masses som^ei
columnar, composed of straight or dirergent fibres.

The crystals of arragonite are seldom colourless, mostly exhibiting a variety of
colours ; yellowish, greenish, reddish, brown, grey, &c. They have a vitreous mbn^
and the powder exhibits phosphorescence on a plate of hot iron. Specific gravity in
the pulyerulent state, and when free from air, nom 2*92 to 8*8 ; Isji^ masses nave
occasionally a specific ^vity as low as 2*77. Hardness about from 3*5 to 4.

Crystals of arragomte are found in various localities; in day and gypsom in
Arragon ; in clefts and cavities of the newer volcanic rocks, especially of basalt, as at
Bilin in Bohemia, in Hungary, Scotland, the Feroe Isles, &c. ; also in the dolerite on
the Kaiserstuhl in the Breisgau ; in gneiss and syoni<>e near Dresden and in Koitb
America ; in the lava of Etna and Vesuvius, dec Radiated arragonitey which ftms
crude masses having a radiated structure, is found chiefly on the Kaiserstuhl in the
Breisgau, at G^rgovie in Auvergne, and in Scotland. Fwroue arragomiet iroihlikm,
or ftoeferriy occurs in globular, kidney-shaped <x stalactilic mass, liavi]^ a fibroas or
laminar texture, and a mother-of-pearl lustre. It is* found in yeins S iron ore in
Carinthia and Styria, Hungary ana Transylvania. 8prudeUtein, a fibrous variety of
carbonate of calcium deposited from hot calcareous sowings, contains both arta^nilo
and calcspar. Mountain mUk^ Rock milk {BergmUch^ Ckaux earbonatei vtd^Mtnk),
is, according to H. Rose, arragonite mixed with chalk ; it occurs in uddk, spongy,
globular, or kidney-shaped masses, or as a deposit in limestone cavities in Wurtesi*
berg, Switzerland, Bohemia, and other localities. Specific gravity 2*72 to 2*81 It
contains traces of organic matter, and leaves a small quantitjr of chtfooal when ignited
in a close yessd. Friable aphrite (Schaumkalky Sehaumerae) was formeriy supposed
to be a variety of calcspar, but has been shown by Gustay Kose to be imgonite,
pseudo-morphosed in the form of gypsum. It occurs sometimes in the form of
gypsum-crystals, sometimes as a crystalline or laminar, white or yellowish-white masB.
The crystals exhibit a strong nacreous lustre on the deayage-fiMesu Its spedfie
grayity, after thorough boiling with water to free it from air, is 2*98. Mm or eJlhm
IS a mineral resembling mountain-milk, extensive fonaations <^ which ace fiMiad in
Southern Bayaria, where indeed it forms a subsoil many feet in thickness. OetteeaiU
(Bfinbruckstein) is a carbonate of calcium mixed with sand and orj^anie remain^
which collects round decaying roots, and takes their peculiar forms ; it is found in the
neighbourhood of Berlin. Its specific eravity is 2*82. It exhibits^ under the mion-
scope, the form of arragonite mixed with granular masses.

Arragonite consists of carbonate of calcium, CO*Ca', or CaO.CO^^ sometimes pn»,
sometimes mixed with small quantities of the isomorphous compound, carbonate
of strontium, which, in the arragonite of MoHna, amounts to 4 per cent. ; small qnan-
tities of the carbonates of magnesium, manganese, iron, &c, are also ooessioDafly
found in it A peculiar yariety called iamowHeite^ from Tamowitz in Upper Silesia,
contains 3*86 per cent of carbonate of lead. The chemical properties of amgoniteaie
essentially the same as those of carbonate of calcium in its other forms ; dilute sci^
howeyer, act upon it less auiekly than on calcspar, so that when a mixtore of eakspar
and arragonite is immersea in a yery dilute acid, a residue of arragonite is obtained
after a while.

Carbonate of calcium, in its two forms of calcspar (rhombohedral), and am^gonite
(rhombic or right prismatic), exhibits one of the most striking examples of dimor-
phism, that is to say, of the same chemical compound crystalfising in two forms be>

ARROW-ROOT — ARSENIC. 359

longiDg to diflfarent syvtems (see IHmobphism). Fonnerlj, when the existence of
dnMniihuiu WM nnknoim, the deTistion of arragonite from the more ordinaiy form of
cnlKiiiate of imlriflm was attribnted to the preaenee of carbonate of strontium, which
Miwwju ciyataUiMB in the ihombie 83rstem. It waa fonnd, howerer that this mineral
was present in amgonite^ often in eztremelT- minnte qnantities, or indeed absent
altogether, the fonn atiJl remaining the same; and thna the fiu^ of the dimorphism
of carbonate of ealdnm became apparent

Ammonite and eakspar exhibit many* dififerencea in their physical properties.
Aimgoiiito has two axes of doable refraction ; eakspar only one. Arragonite has less
■pedfle heat (0*1966) than calcapar, greater hardness and greater density. Large
emtala of arragonite frec^nently cwcrepitate when heated, then swell np suddenly and
fiul to powdeir ; amaller piecesii or fibrous arragonite, become turbid and rotten. The
mineral after this change is Ibund to haye the density of calcspar ; indeed the change
appean to oonrist in the paasage of the arragonite to the form of calspar. This action
may •^p*^^" the poeedomorphosea of calcspar in the fbrm of azragomte. Hitscherlich
deeeribes a crystal of arragonite ih>m Vesuvius, which had been couTerted into calc-
spar on the ootride by the aeticm ot the red-hot lava, while its interior still retained
the structure of arragonite.

The drcmnatancee whidi have determined the crystallisation of carbonate of cal-
eimi in one fotm or the other are not precisely known; it appears, however, to
aasune by pvefeienoe the form of arra^nitie, when it crystallises from hot solutions.
Aeeording to H. Bose (Fogg. Ann. xlii. 863), the precipitate formed on mixing the
boiling Bohrtiena of chloride of ealdnm and carbonate of ammonium, consists of micro-
seopic oystala of arragonite, which, however, diange into rhombohedrons of calcspar
if left fiv some time imder the cold liquid.

The oeearrenee of arragonite in (he depodts of hot calcareous springs points to the
same eonduaoon. The concentration of tne liquid appears also to exert some influence.
Aeeoiding to Becquerel (Oompt rend. xxxiT. 29 and 573), when gypsum is im-
mersed at offdinary temperatures in a concentrated solution of add carbonate of so-
dium, carbonate of caleium is depodted in the form of arragonite, but if the solution
of the add carbonate of sodium is dilute, the depodt takes the form of calcspar. On
the whole it would appear that the tendency to the assumption of the arragonite form
inereaaes with the rapidity of the aystallisation.

ASBO^^IF-KOOT* The starch of the Maranta arundinacea^ a plant belonging
to the order Marantacetty and cultivated both in the East and West Indies. Ac-
cording to Bennm, the root has the following composition : — Starch 26-00 per cent ;
woody fibre 6*00 ; albumin 1*53 ; chloride of caldum 0*25 ; water 65*60 per cent.
In the idand of St Vincent, the skinned tubers are washed and ground in a mill,
and the pulp is washed in cylinders of tinned copper with perforated bottoms. To
obtain the fiseala free from nnpurify, great care must be used in every step of the
process. Palette knives of german silver are used for skinning the deposited fecula,
and even shovels of the same material for packing it The drying is dfected in pans,
eovered by white gauze to exdude dust and inse<^

The term arrow-root is applied generically to indicate a starch or fecula ; thus Fort-
land arrow-root ia obtained from Arum macttlatum; East India arrow-root, from
(htremma an^uMiifoHa; Bradlian, fh)m latropha manihot; Tahiti arrow-root, from
Taeea oeeanica ; Engjlish, from the potato.

Arrow-root, like uie rest of the starches, contains C*'11M)^* The cheaper feculas
are aometimea substituted fbr genuine airow-root ; but they are readily detected by
the microeoope. Arrow-root is one of the most palateable and digestible of the
stardMS. The expressed juice of the plant haa been used as an antidote to poisons and
to the bitee and stings of venomous insects. (See Unfs Dictionary qf ArU^ Manufac-
ture», and Jfinef, i 182.)

An alcoholic liquor, procured by the Tartars f^m fermented mare's milk
(Knmis). In the weak state it xa called araca ; after rectification, arsa.

{Arten, Bckerbenkobaltj FUegeng^i, Napehenkobalif Araenicum, Be-

gtJm» Jrmmci^ the h^vwuAm of Dioscorides.) Symbol^ Am. Atomic weighty 75,
FapouT'densityf 160 (hydrmenaBi); Aiomio volume^ ^,

Astory, — This dement naa been known from very early times, chiefly as sulphide
and aneniouB add. The first accurate investigation of its chemical nature was made
by Brandt in 1733. Sdiede, in 1765, discovered arsenic add and arsenetted hydro-
gen pun Bir H. Davy discovered the solid arsenide of hydrogen. The stoichio-
meCneal rektionsof arsenic and its numerous sulphur-compounds, were spedally
investigated by Berzelius. Bunsen in 1842 discovered cacodyl, an organic radido
eontaining arsenic and methyl, and several other organic arsenic-radicles have since
been dJaooveved by Landolt and others.

A A 4

360 ARSENIC.

Occurrence, — ^Anenio ib found natiye, bat modi more firequentlj aMOciated with
other metals and with sulphur. The ores from vhich it is prepared on the lazge scale,
as a principal product, in the form of metallic anenic or arsenious oxide, are : naHee
arsenic. As; arsenical iron, two spedeSi FeAs, and Fe^As*; and arsenical pjiitea,
FeAs + FeS'. Metallic arsenic and arsenious oxide are likewise obtained as secondary
products from smaltine, doanthiie, arsenical cobalt^ cobalt-fflancef nickd-glance^ copper-
nickdy arsenical nickel^ arsenical fahl-ores, and otiier ores of similar character.

These arsenical ores are found more or less abundantly in Tarious parts of the
world, but chiefly in the mining districts of Gheimany and in the Spanish prorince of
Catalonia. In small quantities, arsenic is Tezy widely diffiised, being found in the
ferruginous deposits of mineral waters (Will, Ann. Ch.Pharm. Ixi. 192) ; in nearly all
iron ores (Waf ch n er, ibid, 209) ; in the various kinds of pyrites, and in natire salDhair.
Hence also it is almost always found in sulphuric acid, and in numerous chemical and
pharmaceutical products, in the preparation of which sulphuric add is used. In short,
arsenic in small quantities is one of the most widely diffiised substances in natnre.
It was said by Orfila (J. Chim. m^ zr. 462, 632) to exist also in the bones aad.
muscles of men and animals in a state of health ; but the eiperiments of other diemiatB
have shown this statement to be erroneous.

Preparation. — ^Metallic arsenic is obtained on the large scale by heating naliTe
arsenide of iron, FeAs or Fe^As', or arsenical pyrites, Fe'AsS, in earthen tabes or
retorts : the whole of the arsenic then sublimes, and iron or protosulphide of iron
(Fe'S) remains behind. The retorts are laid horizontally in a long furnace, a tube
made by rolling up a piece of thin iron plate, is inserted into their mouths, and an
earthen receiver luted on. The aisenic condenses chiefly in the iron tube, in the form
of a coherent internally crystalline mass, and when the tube has cooled, is detached by
unrollins it. The arsenic thus obtained is purified, if necessary, by a second sablima-
tion. The metal is also prepared by heating arsenious oxide with eharooal in earthen
crucibles, surmounted by inverted crucibles, or by conical iron caps. This ia the
process adopted at Altenberg, in Silesia. It is more productive and economical than
the former, but the metal which it yields ia grey and pulverulent^ whereas the former
is compact and nearly white. Arsenic may also be obtained from its snlphidea, fay
heating those compounds with a mixture of charcoal and an alkaline caibonate or
cyanide of potassium. (Eerle's Hiittenkunde, iii 4.)

Properties, — Arsenic is a very brittle metal, of a steel-grey colour. Its specific
gravity in the solid state is, according to different observers, between 6*62 and 5*96.
Vapour-density « 10*3995 (air » 1), or 150 (hydrogen «> 1), which is double the
atomic weight ; hence the atomic volume of arsenic vapour is anomalous, being only
half that of hydrogen. (See Atomic Yoluxb.) Arsenic crystallises in rhombohedrona,
isomorphous with tellurium and antimony. It volatilises at a dull red heat, without
previous fusion, emitting a characteristic disagreable odour resembling that of parlic
Its physical properties vary considerably wiUi the manner in which it is subUmed.
When very sfarongly heated, or when it condenses on a part of the subliming apparatniy
the temperature of which ia but little below that at which arsenic wSatilues, ao
that the metal is deposited in an atmosphere of its own vapour, it condenses in a
compact^ nearly white mass, having a strong metallic lustre. This compact anenic
scarcely oxidises in the air, even when pulverised and exposed to a temperature
of 80^ C. Such is the condition of the metal obtained by heating arsenical pyritea
When, on the contrary, the arsenic, as it passes into the gaseous form, becomes
mixed with otlier gases (as when it is reduced from arsenious acid b^ chsnoalX or
when it is deposited on the colder parts of the subliming apparatus, it solidifies in a
dark grey crystalline powder, less dense than the preceding, and oxidising readily in
the air, especially when heated.

Native arsenic forms botryoidal, kidney-shaped, spherical, and oonchoidal maasea,
varying in texture firom fine-grained to compact ; less frequently, indistinct rhombo-
hedral crystals. In the recent state, it has a light lead-grey colour, but soon becomes
greyish-black by exposure to the air. In its ^emical properties, it resembles artifi-
cially prepared arsenic It is found in various localities of the Saxon and Bohnnian
mining districta, at Andreasberg in the Harz, at Kapnik in Transylvania, Keng»beig
in Norway, and several places in the United States of America.

Arsenic forms two principal series of compounds, analogous to those of antimcmy and

phosphorus, viz. the arsenious compounds in which it is triatomic, e,g. iusH*,

XbCI', (As)'O', (A8)'S', &c., and the arsenic compounds in which it is pentatomie,

e. g, ( As)'0*, ( As)'S^ &c Besides these, there are a few compounds into which it
enters in other proportions, e,g, the sulphide AsS, and several alloys.

ARSENIC: DETECTION. 861

Man J oompoiindB of aneoie are isomorplicnu vith the ooneBponding compoands of
phoephoniB and antimonj, «.y. rhombtetanesnovui oxide ia isomoiphons with native tri-
ozide of antimony: the raits of azsenic add are isomoiphons with the oonesponding
phosphates.

Dbtboxion Axa> EsmciLTioN of Absbnic.

L Reactions in the dry way, — ^Metallic arsenic, lieated with bnt slight access
of air, sa in a narrow test-tube, is conyerted into a yapour haying the peculiar al-
liaceoQS odonr already mentioned, and condenses on the cold part of the tube in a
shining, brownish-bladi:, metallic, ring. With greater access of air, as when a small
qnanti^ of the metal is heated in a wide test-tube, or in a tube open at both ends and
held oyer a lamp in a alanting position, the arsenic is conyerted into arsenious oxide,
which condenses on the cold part of the tube in a white czystaUine ring^ soluble in
boiling water.

The oxides of arsenic heated with charcoal or other deoxidising substances, are
reduced to the metallic state, the metallic arsenic thus liberated exhibiting the cha-
ractera just mentioned. If a small quantity of arsenious oxide be placed on charcoal,
and the point of the blowpipe flame directed upon it, a greyish-white smoke is imme-
diately eyolved, accompanied by a powerflil alHaceous .odour; and if the arsenious
oxide be mixed with perfectly dry and coarsely pounded charcoal, and heated to red-
ness at the bottom of a small test-tube, a ring of metallic arsenic will be deposited on
the cold part of the tube.^

The snuphides of arsenic, and the salts of arsenious and arsenic acid, are not easily
reduced by ignition with charcoal alone, but when heated with carbonate of potassium
or sodium, or with a mixture of an alkaline carbonate and charcoal, or cyanide of potas-
sium, they yield metallic arsenic with its characteristic properties.

XL Beaciione in the wet way. a. Of Areenioua Compounds. — ffydrosidphurio
aeid aas passed in1» an aqueous solution of arsenious acid, colours it yellow, and on
addition of hydrochloric acid, throws down the whole of tiie arsenic in the form of
bright yellow triaulphide. The precipitate is said to be perceptible in a solution con-
taining not more than 1 pL of arsenious add in 160,000 pts. of water. The predpitate
disaolres easily in ammonia, carbonate of ammonium, and sulphide of ammonium, and
SB repredpitated without alteration by hydrochloric add. It is likewise soluble in
a eonaiderable quantity of boiling water, and in boiling dilute hydrochloric add, with
liberation of hydrosnlphuric add gas. (Odling, Guy's Hospital Beports 1^81 i. 239.)

NitnUe of sutwr added to aqueous arsenious addproduces a scarcely appreciable yeUdw
turbidity, and en cautiously adding ammonia, a canary-yellow predpitate of arsenite of
aibrer, which diasolyee with great fiuility in nitric add, acetic ado, and excess of ammonia.
Hence, if the quantity of arsenie present is but small, it is difficult to ayoid adding too
much ammonia, and thus preyenting altogether the formation of the precipitate. This
inoonvenience may howeyer be obyiated by usine a solution of nitrate of argeniam-
numium, oommonly called ammowUhnitraC^ of suver^ prepared by treating a solution
of nitrate of silyer with a quantity of ammonia suffident to redissolye only a portion
of the precipitated oxide of silyer, and filtering. Such a solution contains exactiy the
proportion of ammonia required to predpitate the arsenious add as arsenite of silyer.
iS, nowerer, an excess of nitric add is present, a further quantity of ammonia will be
required to neutralise it. In a neutral solution of an arsenite of alkali-metal, nitrate
of silyer produces an immediate predpitate of arsenite of silyer.

With suiphate ofoopper^ on addition of ammonia, arsenious add forms a bright green
preeLpifAte of arsenite of copper (Scheele's green), easily soluble in acids and in am-
nonia. In this case also, it is conyenient to use a solution of sulphate of cupram-
mtmiwm, or ammoniO'Suiphate of copper, SO^NH'Cu)', prepared in the same manner
aa the ammonio-aitrate of silyer.

Jfiirie add, hypoehlorous add, ehromie add, and other oxidising agents^ conyert
ajsenioos add into arsenic add. With a solution of trichloride of .gold, it yields arsenic
add, and a blaek predpitate of metallic gold.

A piece of metallic copper immersed in a hot solution of arsenious add or an arsenite,
mixed with hydrochloric add, becomes coyered with a grey film of metallic arsenic,
which may be sublimed and conyerted into arsenious oxide by heating the coated
metal in a dry g^ass tube (Beinsch's test).

Zine immersed in a solution of arsenious add or an arsenite addulated with hydro-
dilorie or sulphuric add, likewise reduces the arsenic to the metallic state, part of the
reduced arsenic being deposited as a black film on the zinc, while the rest unites with
the nascent hydrogen and escapes as gas ; and from this gas, which bums with a
peculiar greyish flame, the arsenic may be separated in the metallic state, either by
passing the gas, after drying with chloride of caldum, through a narrow glass tube,
one part of which is heated to redness oyer a lamp, the metal being then depodted

362

ABSENIC: DETECTION.

in the eold part of the tabe 1>e70iid the flame ; or else loj banuiig liie gag tt fhe
extremity ol the tabe dnwn out to a fine jet, and balding in tbe flane, near tka
orifice, a plate of dean vbite poioelain. The aaenic is then depoiited on the date ia
browmah-black, shining metallie filma, which may be distingaiBhed from tlion of
antimony formed in like manner ({^ 820, 322), by their aohittlity m aqneoos hjpo-
chlorite of sodium, and by other characten to be nodoed hereafter.

This reaction, which is known as Marsh* s test, is extremel^r delicate, and is thercfen
mnch used in sffliyliiTig for minnte quantities of arsenic, especially in eases of poisoiung.
A conyenient apparatus far the purpose is that represented in fy, 72. ▲ is the gene-
rating yessel, provided with a fiumel-tabe b, for intiodncing tlie actd and the solstiaii

^.72.

tobetested. o is adzying-tabeoontaaningddorideolealeiam; BxUiemdBetiop-tiibe
which should be of hard ^paas, free from lead. It is oonvenient to have this tabe
contracted at one or two points, as shown in the figure, and tomed up at zigfat an^
at the end, so as to Ibrm a vertical jet. The Snlt thing to be done is to asnitain
whether the zinc and acid are free from arsenic For this purpose, they must be iatio-
duced into the generating vessel, without the solution under eramination, and after tbe
evolution of gas has continued long enough to e:q>el atmospheric air, the redadioD-
tube is to be heated at a b^ a lamp-flame &r about a quarter of an hour, and the at
set on fire at the jet f, a piece of white porcelain being held in tiie fiame. If node-
position of arsenic takes nlaee either in the tube or on the porcelain, the li^ tolie
tested is then to be pourea in through the ftmnel-tube and the heating oontniued. If
arsenic is present, it will be deposited in a shininff minor at b, a uttle befoodtiie
fiame. After a sufficient deposit has been obtained at that point, the krmn nay be
removed to o, when a aeoond deposition will taJbe place at <2, and so on. If tbe qoaa-
tity of arsenic is conaiderabU^ spots may also be obtained on a plate of porcebin held
in the flame at n. The portions of the reduction-tube containing the dqponti vtj
then be cut off with a file, sealed, and reserved fior fluther ezanunatiott.^ Instetd <x
bumijag the escaping gas at n, it may be passed, by means of a tube joined to the
reduction-tube by a caoutchouc connector, into a solution of nitrate of silver. Xetaihe
silver will then be deposited, and the whole of the araenae will remain in aoihituin »
anenious acid.

A solution of arsenioos add acidulated with hydrodilcnic or sulphazie add, ia de-
composed by the eiectrio eurrmt, the greater part of the arsenie eliminated it the
negative pole being given off in the form of arsenetted hydrogen, which ^"^J^
examined as above (Blozam, Ghem. Soc Qn. J. sdii. 14). &e appsratos nsed
consists of a two-ounce narrow-mouthed bottle, the bottom of which has been cat off
and replaced by a piece of vegetable parchment tightly stretched over it, and senred
bv a ligature of platinum wire (any ligature of organic nature, even vulcanised caoatf
chouc, would be quickly destroyed by the ozone evolved at the positive pQle)> ^
bottle is fuznished with a cork, canyinff a small tube bent at nght an^es, and at-
tached to the reduction-tube by a caout<£ouc joint, also a flannel-tube for introdaong
the liquid to be tested. Through the cork there likewise passes a nlatiniim vir^
carxying a plate of the same meUl, which forms the negative pole of the vottaie or-
cuit The bottle is placed within a glass of such a sise as to leave a bbmU iotenil
between the two, this glass standing in a vessel of cold water. An ounce of dilate
sulphuric add is introdiued into the apparatus, so as to fill the bottle and the oater

ARSENIC: DETECTION. 363

■ptee to iboot tbe same level, the poeitive pkte bebg immefsed in the a4!id contained
in this outer space. The ennentof a Toltaic batteiy (6 Ozoye's eeUe of ordinary size)
is then passed thzoogh the ammgemait^ and the shoulder of the reduction-tube is
heated to redneas for aboat a quarter of an hour, to ascertain whether any deposit of
anenie is produced £rom the sulphuric acid itself : if the result be ne^tire^ the liquid
to be tested is then introduced uirough the Ainnel*tube and the heatug of the reduc-
tum-tnbe is continued. This method is extremely delicate, even j^ of a grain of
SRenioiia acid diffused tiirongh a considerable quantity of liquid, producing a per-
ceptible deposit in the reduction-tube after 15 — 30 minutes.

The electrolytic method of eliminating arsenic possesses certain advantages over that
of Manh : — 1. It aToids the use of zinc, and thereby obviates a frequent source of error
■rising tram the presence of arsenic in that metaL — 2. It introduces no substance into
the liquid that can interfere with its subsequent examination for other metals. — 3. If
any oueir metals are present^ it jHtecipitates them on the surface of the negative plate.
Even antimony is for the meet part precipitated in this manner. When the reduction
is efiected by zinc^ antimonj if present is evolved, together with the arsenic (p. 322),
and the subsequent separation of tiiese metals is troublesome ; but with the electrolytic
method, as above described, only a very small quantity of antimony is evolved as anti-
monetted hydrogen ; and even this quantity may be omipletely arrested b^ adding to
the liquid a solution of hydrosulphuric acid. Both antimony and arsenic are then
converted into sulphides ; but the sulphide of arsenic is reduced by the electrolytic
hydrogen aa easily as arsenious acid (see below), whereas the sulphide of antimony
eompJetefy leststs the action of that agent, and remains in the liquid.

0. OtArstnic Compounds, — A solution of arsenic add gives with nitrate of silver^
without addition of ammonia, a red-brown precipitate of arsenate of silver easily soluble
in ammonia and in nitric acid. It does not precipitate stUphaie of copper until am-
monia is added, and the precipitate then produced is of a pale bluish-white colour,
qm'te distinct from Scheele's green. With sulphate of maanesium, ammonia^ and
chloride of ammonium (the last being added to prevent the precipitation of hy-
drate of magnesium), arsenic acid forms a white crvstalline precipitate of arsenate
of magnesium and ammonium, AsMg'(NH^)0^ + 6H'0, similar in appearance and
in constitution to the phosphate of magnesium and ammonium. If the solution
is very dilute, the precipitate does not appear immediately but is deposited in
eiystals, after a few hours on the sides of the tube. Molyhdate ofamanonium added in
excess to a solution of an arsenate containing free nitric acid, yields, when the liquid
is heated, a bright yellow precipitate of arseno-molybdate of ammonium; exactiy
similar to tiie phosphomol^bdate (see Phosphobio Acm). This precipitate is in-
soluble in adds, but soluble in ammonia, and in excess of the arsenic solution; hence
it is especially adapted for detecting small quantities of arsenic add, and is indeed
one of the most delicate tests for that add, provided no phosphoric acid is pre-
sent: With aeequiealte of iron and uranium^ arsenic acid forms yellowish-wnite
predpitates. With Uad-ealts, it forms a white predpitate of arsenate of lead, which
when heated on charcoal in the inner blowpipe flame, gives off the odour of arsenic,
and yields a button of metallic lead. Hydrosulphuric acH gas passed through a solution
of arsenic add colours it yellow at first, and aiter a long time produces a yellow pre-
dpitate of trisulphide of arsenic, mixed witli sulphur, the precipitation being accelerated
by heat A solution of a neutral arsenate of alkali-metal, through which hydro-
solphuric add gas is passed, yields the same predpitate on addition of hydrochloric
add. Sulphurous acid^ phosphorous addt and other deoxidising agents reduce arsenic
add in solution to the state of arsenious acid. Hence in a solution of arsenic acid
mixed with sulphurous add or a soluble acid sulphite, hydrosulphuric add produces
an immediate predpitate of trisulphide of arsenic.

Nascent hydrogen evolved by the action of zinc on dilute sulphuric or hydrochloric
add, converts arsenic add into arsenetted hydrogen, which is evolved as gas (Scheele,
L. Gmelin); but the action is much slower than with arsenious acid. When an
dectric current is passed through a solution of arsenic add, metallic arsenic ia
dqxMited on the negative pole (Gmelin*s Handbook, iv.), and arsenetted hydrogen is
evolved provided no chlorides are present (Bloxam) ; on adding sulphurous add, or
add sulpnite of sodium to the solution, whereby the arsenic add is reduced to arsenious
add, tiie evolution of arsenetted hydrogen is greatiy accelerated. The same effect is
produced, even with greater certainty on adding aqueous hydrosulphuric add to the
solution. Hue effect is also chiefly due to the reduction of the arsenic add to
aisenioua add ; but even when the hydrosulphuric acid is added in excess, the evolu-
tion of the arsenetted hydrogen still takes place, the arsenic uniting with the hydrogen
in pre^rence to the sulphur. (Bloxam, Chem. Soc. Qu. J. xiii. 138.)

Compomid* "»^^^M*» ia water, may be examined tor arsenic by dissolving them in

364 ARSENIC: DETECTION',

hydrochloric acid ; passing hjdrosnlphturic acid ma throng the solntioii ; digeeluig
the precipitate with sulphide of ammonium, to cQaaolTe out the sulphide of arsenic;
and precipitating the sulphide of arsenic by hydrochloric add. The predipitate may
then be dried, and reduced by heating with carbonate of sodium and diarooal, or di»-
solred in hydrochloric acid, with addition of chlorate of potassium, and the sohztioD,
which will contain arsenic acid, tested as above.

The following characters t€iken together are sufficient to distingniah azsenic from all
other substances.

1. Formation of a black shining metallic sublimate by one of iha methods of redac-
tion above described.

2. Conversion of this metallic deposit into white crystalline arsenious oxide bj smb-
limation in contact with the air.

3. Solution of this sublimate in boiling water, and production of the reactions chazme-
teristic of arsenious add, viz. yellow with hydrosulphuric add, yeUow with ammonio-
nitrate of silver, light green with ammonio-sulphate of copper.

4. Solution of the metallic sublimate in hot nitric acio, and production of the re-
actions characteristic of arsenic add, viz. red-brown with nitoite of silver, white
crystalline with ammonia and magnesium-salts, bright yeQow with molybdato of
ammonium.

The metal with which arsenic is most likely to be confounded, is antimcmy,
espedally when the reduction to the metallic state is effected by Marsh's method,
(pp. 320, 322.) The arsenical and antimonial deposits obtained in this mannepj znmy
however be distinguished by the following characters:

The arsenic-mirror has a strong lustre, and a black-brown, or brown-black oolour;
thin films of it formed in a glass tube, appear perfectly translucent^ with brown colour,
when held before white paper. On account of the volatility of arsenic, the deposit
is formed only at a certain distance from the heated portion of the tube, and always
on the side towards which the stream of gas is directeo. The spots formed on porce-
lain have a black-brown, or when very thin, a brown or light brown colour. The
antimony mirror on lihe contrary Lb formed in the reduction tube on both sides of the
flame and dose to it. Where most strongly heated, it has a whiter colour, and when
examined by a lens, exhibits small fused metallic globules. It is brownish in thin
films, but not continuouslv brown and shining, like that of arsenic. A ntimony-^)ots
formed on porcelain are velvet black, and without lustre, unless very thin ; in that case
they have an iron-black, or darkplumba^ colour, brownish-grey at the edges.

H the part of the reduction-tube containing the arsenic-mirror be cut o£^ and heated
in a gmaU lamp flame, the flame exhibits me characteristic greyish colour, and the
strong garlic odour of arsenic becomes peroeptible. If the pieces of tube covered
with arsenic are heated in a narrow test-tube, the characteristic white aystalline
sublimate of arsenious oxide is formed, perfectly soluble in boiling water, and ex-
hibiting the characters above-mentioned.

The antimony-deposit does not give off any odour when heated in a lamp-flame, and
if heated in a wide test-tube, yidds a white shininff sublimate of oxide, which is in-
soluble in water and in ammonia, but dissolves readily in hydrochloric add, the soln-
tion yidding with hydrochloric add the characteristic red predpitate of antimonions
sulphide.

The arsenic-mirror dissolves readily in an alkaline solution kypoehiorite ofaodiamt,
the solution exhibiting the characters of arsenic acid. The antimony-minor is in-
soluble in the same liquid, provided it does not contain firee chlorine.

Nitric acid of specific gravity 1*2 to 1*3 dissolves the arsenic depodt in the cold, or
at a gentle heat, the solution exhibiting the characters of arsenious add ; at a stronger
heat, arsenic add is formed. The same add likewise dissolves the antimony mirrar,
but the solution is turbid, gives no predpitate with nitrate of silver and ammonia,
orange-yellow, with hydrosulphuric acid.

A very good way to identify arsenic spots is to collect one or mora in a watdi-glasi^
add a drop or two of nitro-hydrochlonc acid — evaporate quite to dryness, moisten
with water, and then add nitrate of silver solution.

Yellow sulphide of ammonium dissolves arsenic spots with great difitolty, and
never completely ; and on evaporating to dryness, there is always left a grey stain of
arsenic in the midst of the yellow orpiment Antimony spots dissolve at once and
completdy, and the oran^-red sulphide of antimony left on evaporation, dinolves
completely in hydrochloric add, being converted into chloride, wnich volatihaes, or
leaves only a slight residue of white antimonions oxide.

The arsenic-depodt is easily dissolved in the cold hj hydrochloric acid with addUitm
of chlorate of potaseiumy and the solution yields, with magnedum-salts, mixed with
ammonia and tartaric add, the crystalline predpitate characteristic of azwnic add.

ABSENIC: DETECTION. 365

Tlie antimonj-deposit flomilarly treated, dissolTes only when heated, and the solution
mixed with tartaric add and ammonia is not precipitated by magnesinm-salts.

When azsenetted hydrogen is paased into a solation of nitrate of n/wr, metallic
■Qrer is precipitated, and ^ the anenic remains in solation afl araenious add, which
may be predpitated bysnlphnretted hydrosen, &e.; but when antimonetted hydrogen
is paoeed into nitrate of silyer, the whole of the antimony is predpitated in the
metallic state, together with the silver, and the solation, after being freed from excess
of silver by hydroiBhloric add, gives no predpitate with snlphoretted hydrogen.

It often hi^ypena that antimony and arsenic are evolved together as gaseous hy-
drogen-eompoands. In that case, the two metals may be separated by the reaction
with nitrate of silver just mentioned * ; by dissolving the metallic mirror in hvdio-
diloric add, with addition of chlorate of potasdnm, then adding tartaric add and
ammonia, and {oedpitatinff the arsenic by solphate of magnesium ; or by gently heat-
ing the deposit in a very uow stream of diy salphnretted hj^dro^n, whereby both are
converted into sulphides, and then passing diy hydrochloric aad through the tube.
The 0u]^>hide of antimony is thereby conv^ted into chloride, which passes on with the
stzeam of gas, and may be reodved in water and further tested, while the snlphide of
arsenic remains unaltcml. Kthe hydrochloric add gas is not perfectly dry, a small
portion of the antimony will be left behind as oxide.

For other methods of separating arsenic and antimony, see page 368.

Detection of Arsenic in eases of Poisoning, — Kearly all compounds of
aiBcnic are poisonous, the most soluble being, generally speaking, those which act wiUi
the greatest violence. But arsenious oxide, commonly cailed arsenious acid, being the
most generallv known and easily procured, is that which is most likely to be met with
in cases of poisoning bv arsenic, whether acddental or intentional.

As arsenious oxide is but sparingly soluble in water, and is generally administered
in the solid state, mixed with visdd articles of food, such as grud or rice, it some-
times happens that, by careful examinatioii, small lumps of it may be found adhering
to culinary vessels, &&, or even to the coatings of the stomach and intestines after
death. When this is ^e case, the arsenic may be picked out and reduced to the
metallic state by heating it with charcoaL

H the arsenious oxide is too finely divided to be picked out in this manner, it may
sometimes be separated by stirring up the mass several times with water, and leaving
the heavier partides to settle. Any solid arsenious add that may be present will be
sure to be fraud in the reddne, and may then be washed with cold water and dried
over the water-bath.

The oxide thus separated may be reduced to the metallic state by heating it in
a small test>tube with charcoal, as described as page 361. A good way of efiect-
ing the reduction, is to place the dried granules or powder at the bottom of a small
test-tabe^ drawn out as shown in fy, 73, and place above it a splinter of well-dried

Fig. 73.

charcoal, A The tube is first held in a horizontal position with the part a in the
fiame of a lamp, so as to heat the charcoal to redness ; it is then graduallv inclined
to volatiliae the arsenious add, and cause the vapour to pass over the ignited charcoaL
A speculum of metallic arsenic then collects at the shoulder of the tube, and may after-
wards be reconverted into arsenious oxide by sublimation in contact with the air, as
aheady described (p. 861).

More frequently, however, the arsenic is intimately mixed with large quantities of
oiganie matter, such as articles of food, vomited or evacuated matters, portions of the
aiunal body, as the stomach, liver, &c. In such cases. Re in s c h' s test (p. 361) may be
very eonveniently applied. The suspected matter, if liquid, is addulated with about
one-sixth of its bulk of hydrochloric add and boiled. The solid tissue is cut up into
very f^*X\ pieces and boiled for some time in a mixture of 1 pt of hydrochloric acid,
and 6 parts of water, till the whole is completely disintegrated, and then strained
through musUn, or filtered through paper previously wetted. Pieces of coppeivgauze or
ibfl are then to be immersed in the boiling liquid, and if any ^y deposit is produced,
fresh pieces must be added as long as any perceptible alteration of colour takes place
<m the sorfaee of the metaL They are then to be removed, washed with distilled

• Tl* bstt node of dctsettnf hmII qoantltiM of antimony thai precipitated it, after eareftilly wuhing
oot the arMDioaa add, to dlntt the precipitate in aaueout tartaric acid ; the antimony then alone dl»-
lolTCt, and may be tested bj nydroBnlpburic acid. ( H o f m an n, Chom. 8oc. Qu. J. xiil. 79.)

866 ARSENIC: DETECTION.

water, and dried between bibulous paper, folded np, intzodueed into a diy test tnlie,
and heated over a lamp. The arnenic ia thereby converted into anenioos oxide, videfa
collects on the cold part of the tube in the form <:£ a cryBtalline snblimate. It may be
diflBolved in water and tested with nitrate of silver, &a Inasmndi as Beiosdii'B pro-
cess involves the solution of a minute quantity of copper, the foil Gt gause employed
should be so Ikr free from arsenic that the solution of four or five gnios of it should
not vield a trace of the poison.

The ars^c may also be detected by other methods which, however, for tiie most
part require more complete destruction of the organic matter. This may be effected
by one of the following processes :

1. The organic matter is mixed with about a fourth of its weight of strong sul-
phuric acid, and heated till the whole is reduced to a dry fiiable carbonaceous mass;
and this residue, after being pulverised, is treated with nitric add mixed with a small
quantity of hydrochloric acid, in order to bring the arsenic to the state of anenie add,
which is very soluble in water. The mixture \b then evaporated to diyness, and tlie
residue boiled with water and filtered. If the organic matter contains alkaline chlorides,
which is frequently the case, care must be taken not to heat it more strong than is
necessary for complete incineration, otherwise a portion of the arsenic may be oonTsrted
into chloride and lost by volatilisation. — 2. The organic matter is gently heated in a
tubulated retort with strong hydrochloric add, and nitric add is added by small
portions at a time. The organic matter is thereby completely destroyed, with the
exception of the fat The liquid, which is transparent and colourless, is then decanted
from the fatty matters ; the latter are well washed with water ; and the waBhinga, toge-
ther with the distillate in the receiver, are added to the main bulk of the liquid (Gaul-
tier de Claubry, J. Pharm. [3] xvii. 125). — 3. Chlorate of potassium may also be
added in succes^ve portions instead of the nitric add.— 4. The organic matter, after
being comminuted as much as possible, may be suspended in water, and chlorine eu
passed through the liquid till the organic matter is partly destroyed and partly de-
posited in brown flakes. — 6. The organic matter, after being dried, is mixed vHh
nitre, and the mixture projected by successive portions into a red-hot crucible. The
arsenic is thereby converted into arsenate of potassium, which dissolves readily in
water. (Wohler.)

Mr. Graham finds that a most effective separation of the organic matter capble of
interfering with the predpitation of arsenic by reagents, may be effected by his apps*
ratus for the difiusion of liquids. A flat hoop of white wood or gutta-p^cha, about
ten inches ia diameter, is covered with a sound sheet of parchment>paper, so as to fom
an instrument like a tambourine in form. The organic fluid is placed within the
instrument so as to cover the parchment bottom to the depth of half an inch, and the
whole is then floated upon distilled water, contained in a basin. Three-fourths of the
arsenious add present are found to escape by difiusion and enter the water below, in
the course of twenty-four hours, giving a perfectly colourless solution. To this liquid,
when concentrated, all the ordinary tests of arsenic may be applied. (See Diffusuxi
OF Liquids.)

A dear solution having been obtained, the arsenie may be separated from il in
either of the following ways :

1. By Precipitation as TristUphide, — ^The dear arsenical solution is saturated with sul-
phurous add to reduce the arsenic add to arseaiious add, the excess of sulphurous add
IS expelled by gentle heating, and a stream of sulphuretted hy^drogen gas parsed throogh
the hquid for a condderable time. The predpitated trisulphide of arsenic is then care-
fully washed with cold water, dried, and reduced to the metallic state by healtin^ it in a
small tube having a bulb blown at the end with a mixture of dry carbonate of sodium and
charcoal, or cyanide of potassium. The bulb, after the introduction of the mixture,
should 'flrst be gently heated over a lamp to expel moisture, the tube then wiped out
with filtering paper, and the bulb strongly heated in the blowpipe flame. A ring of
metallic arsenic is then deposited in the tube, and may be treated as already described.

2. Bif Conversion into Arsenetted Hydrogen, — ^This may be efiected either by Uarsh'i
or by Bloxam's process (p. 362). The former has long been used by toxicdegistk
It is extremdy delicate, and indeed has nearly superseded all other methods, 6zce(A-
ing that of Keinsch. If the liquid to be testcMl has been effectually freed from
organic matter by dther of the methods just given, so that there is no lon^ saT
danger of frothing, it may be introduced, together with the sine and sulphuric acid,
into an ordinary gas-^nerating vessel, provided with a drying tube and reduetioik-
tube (p. 362). Peculiar forms of apparatus have, however, been devised for peifonn-
ing the process without the trouble of completely removing the organic matter. Saeh
is the original apparatus of Marsh, a figure and description of which are given in
Graham's Elements of Chemistry, 2Dd ed. vol ii. p. 216. Another form m appa-
ratus, contrived for the purpose by a committee of the Prussian goveniment, and

%.'

ARSENIC : ESTIMATION. Sff!

siBplified by the Ute Dr. Ure, is described in IMt Dietumary of Arts, Manivfao-
tures^ and Mmu, new edition, i 189.

It is fimnd hoireTer, that the pmsenoe of oiganie matter BOmetimeB completely pre-
T«nts the detection of minnte qvaatities of aisenic by Marsh's process (O a ling,
Ga/s HoqpitaLB^MxtB,[3] y. 367 ; Phaim. J. Trans. [2] i 374). Hence it is better in
•II caeesi before applying this test^ to eliminate the organic matter by one of the jpro-
oeflses above descnbed. It most be obeerred, howerer, that idl these processes yield
the aneoie in the form of arsenic acid, so that it becomes necessary to add snlphnroiui
add or acid sulphite Gt sodium, in order to reduce it to arsenious acid. Another
mode of prooee<ung, recommended by Odling Uoc, cU,\ is to mix the suspected sub-
stance with strong hydrochloric acid, distil to diyness and test the distillate. In this
case tiie addition of sulphurous acid is unnecessary.

Bloxam's electrolytic process is of recent introduction and has not» so far as we are
aware, beim yet applied m judicial inyestigataons ; but it appears to present sereral
adyantages oyer that of Marsh, especially in securing, by the addition of hydrosul-
phnrie acid to the liquid, the complete separation of arsenic and antimony, the former
being then eyolyed as arsenetted hydrogen, the latter remaining wholly in the liquid.
The certainty of this separation is of especial im^rtance in the inyestigation of cases
of poisoning by anenic, inaamuch as tartar-emetic is often giyen in wnioi cases to pro-
dnce yomiting.

In an processes of testing for arsenic, it is of the utmost importance to ensure that
the indications obtained of the presence of that substance do not proceed from the
reagents themselyes. Arsenic is yery widely difinsed in the mineral kingdom, and
hence it is by no means on easy matter to procure reagents absolutely free from it.
dalphnric acid, hydrochl(»ic %xi% and zinc are often contaminated with it, and con-
sequently Marsh's process, in which these reagents are employed, is yeiy liable to giye
inoorreet indications, nnleas the precaution be taken of testing the reagents in the
manner already described (p. 862) before introducing the suspected Uquid. Sul-
phuretted hydrogen, eyc^yed by the action of dilute sulphuric acid on sulphide of
iron often contains arsenic, pn)ceedin|f from one or both of the substances used ; but
that which is erolyed by heating natiye sulphide of antimony with hydrochloric acid
is generally fr«e from it^ because sulphide (rf* arsenic, even if present in the sulphide of
antimony, is not decomposed by hydrochloric acid. The oomjuete destruction of organic
matter by the processes described at page 366, requires the use of considerable quantities
of solphuric or hydrochloric acid ; consequently the arsenic contained in the acid is
likely to accumulate in the result^ liqmd in sufficient amount to make itself yisible
in the subsequent examination, eyen though the proportion of it contained in the add
may be too small to be perceptible in the comparatiyely small quantities required for
tho actual testing. This oondderation traids rather to induce a preference for methods
which do not require so con^lete a destruction of the organic matters, such as Eeinsch's
en the deetrolytic process.

Quantitative Estimation of Arsenic. — When arsenic is contained in a solu-
tion eotirelr in the form of arsemc add, it is best to precipitate it in the form of
azeenate of magnesium and ammonium, A8Mg*(NH*)0^ + 6HH), by nuzing the
aohition with excess of ammonia, and then with sulphate of ma^esium, addine also a
qoantity of chloride of ammonium suffident to preyent the precipitation of hydrate of
magiMna by ammonia. The Uquid is left to stand for some hours, and the predpitate
is ooUeeted on a weighed filter, and washed with water containing ammonia. It may
then be dried, dther in yacno or sulphuric add, in which case it retains all its water
of eryatallisation — ormore expeditiously at 100 ^., in which case it loses }| of its water,
and m reduced to AaMg^(KH*)0^ + AHK), or rather 2[AsMg* (NH*)0*] + H»0, from
which the quantity of arsenic is easirr calculated.

If arsenic exists in solution in the form of anenious add, it may either be brought
to the state of arsenic add by oxidation with nitric acid, and the anenic determined
t^' as abore, or the arsenic may be predpitated as trisulphide b^ hydrosulphuric add,

i^ the solution bein^ preyiousr]r acidulated with hydrochloric acid, and the predpitate

fl- collected on a weighed filter, washed and dried at a temperature a little aboye 100° C.

X If the trisulphide were quite pure and definite, its quantity might be at once deter-

% mined 1^ dniuctiiig the weignt of the filter from the gross weight, and the quantity

«• of acMoio calculated from the formula As'S'. But^ as the pradpitate almost always

<• eootains free sulphur, the quantity of arsenic in it must be estimated by oxidising the

^ sulphur with strong nitric add, and proceeding in a manner exactly similar to that

^ which has been dessribed for the estimation of antimony (p. 821).

ff Arsenions add may also be estimated by its reaction with trichloride of gold, which

^ oonyerts it into arsenic add, and at the same time yields a predpitate of metallic

f r^ gold, eyeiy 4 at of gold corresponding to 3 at arsenious add :

4AuCP + 6H*0 + 8As*0« « 4Au + 12Ha + 3As«0».

868 ARSENIC : ESTIMATION AND SEPARATION.

The gold solution used for the purpose is the sodio-chloride or ammonio^oride
(see Gold) : it must be free from nitric acid.

When arsenions and arsenic aeids exist together in solution, the latter msT be pre-
cipitated as ammonio-magnesian arsenate (a considerable quantity of chloride of
ammoninm bein^ added to prevent the aimnltaneons precipitation of the aneoioos
acid) ; the arsenious acid in the filtrate is oonrerted into arsenic add bj ozidAUoo
with chlorate of potassinm and hydrochloric acid, and then pecipitated in the
same manner ; or the arsenions acid may be estimated by chlonde of gold, as just
described.

Atomic Weiaht of Arsenic. — ^Ber2elin8(Schw. J. xzziiL 172) determined Uie
atomic weight of arsenic from the quantity of snlphnrons anhydride prodaced by heat-
ing arsenious oxide ■-^*** — i-*— '•^- — — * — - oi_«r« .cm c ■ —

shows that 1 at. AbH
2*203 grm. AsK)' gaye

senious oxide with sulphur. I^e equation, 2AbK>* + S* » 2A8^ + 380^,
that 1 at. AsK)*, yields 11 at. SO*. Kow in an experiment made by Benelioe,
grm. AsK)« gaye 1'1069 SO*. Therefore :

and deducting 0* >» 48, there results As* *- 149*84 and As — 74*92. Felovze
(Compt. rend. xx. 1014) decomposed pure trichloride of arsenic with water, and de-
termined the quantity of hydrochloric add produced by means of a standard ^lotioo
of silyer. His results (calculated with the atomic weights of sOyer and chlorine nov
adopted (Ag « 108 ; 01 ^ 36*6), giye as a mean of t&ee experiments, Ab « TS-Oi
The mean between this number and that of Beraelius ia exactly 76.

Separation of Arsenic from other Elements, — From other metals of the
second and third groups (Akaltsis, Ikoboamic), and from all non-metallic elemcDt^
excepting selenium, arsenic is separated by predpitation with hydro-snlphnrie add
gas in add solutions. From those metals of the first group whose sulphides are in-
soluble in alkaline sulphides, lead, copper^ sUveTf &c, it is separated by precipitatiog
with hydrosulphuric acid, digesting the precwitate with sulphide of ammoniiim,
and acidulating the filtered solution with hydrochloric acid. From seUmum and
tellurium^ it is separated by sulphurous add, which predpitatas those eUanents ficon
their solutions in tne free state.

Separation from Antimony, — ^When arsenic and antimony exist together in the fana
of an alloy, they may be completely separated by heating the oompomid to Unriednesi
in a stream of carbonic anhydride, the arsenic then yolatilising and the antimony re-
maining. Antimony is, howeyer, the only metal from which arsenic can be completely
separated in this maimer ; if the alloy contains any^ other metal, some of the anenie
wOl be retained, and the method is no longer apphcable. When this is the case, &e
alloy may be diasolyed in hydrochloric aci{ to which nitric add or chlorate of potas-
sium is gradually added ; the solution diluted with water after addition of tartaric
add, is then mixed with a considerable quantity of chloride of ftrnmnninm and excess
of ammonia, and the arsenic predpitated by adoition of sidphate of magnesium. The
antimony may then be precipitated from the filtrate by hydrosulphuric add. This
mode of separation is equally applicable when the two metals are in the state of
sulphides ; as, for instance, when th^ are predpitated together from solution by hydro-
sulphuric add. When they occur together as oxides, they may be dissolyed in hydro-
chloric acid, mixed with tartaric add, and treated as aboye ; or they may be squinted
by fusion with caustic soda in the maimer to be presently described!

The separation of arsenic from tin may be ^ected by conyerting the two metals
into sulphides, and separating them, after drying and weighing the ^ole, by ignition
in a stream of hydrosulphuric add gas. The mixed sulphides are introduced into a
wdghed glass bidb, haymg a tube attached to it on each side. One of these.tabes,
the exit-tube, must be at least a quarter of an inch in diameter, to preyent stoppage,
and bent downwards so as to dip into a fiask containing ammonia. The whole ii
then weighed, hydrosulphuric acid gas passed through the iwparatus, and the bulb
heated tm the whole of the sulphide of arsenic ia sublimed. Part of the sulphide of
arsenic passes into the ammoniacal liquid, bjr which it is dissolyed, and the rest
sublimes in the wide tube. When the operation is ended, and the ammratns has
cooled, the wide tube is cut off at a short distance from the bulb, then broken, and
the pieces digested in caustic potash to dissolye out the sulphide of arsenicL The
solution thus obtained is added to the ammoniacal liquid in the fiask ; the sulphide of
arsenic is precipitated by hydrochloric add, and oxidised, without preyious fittratian,
with hydrochloric add and chlorate of potash ; and the resulting arsenic add ra pre-
dpitated by ammonia and sulphate of magnesium. The sulphide of tin remaining in
the bulb is oonyerted into stannic oxide by treating it with strong nitric add.

Separation of Arsenic from Antimony and Tin together. — The separation of these

ARSENIC: ESTIMATION AND SEPARATION. 369

IhiM metab is attended with eoxuiiderable dif&cnlty. The best mode of effecting it
is to cajifert them into arsenate, antimonate, and sstannfite of sodium, and treat the
odzftim irith dilute alcohol of a certain strength, -which dissolyes the arsenate and
stamiate of sodium, and leaves the antimonate undissolved.

If the throe metals exist together in solution, they are precipitated as sulphides by
hjdrosolphmc acid, and the sulphides are fbsed in a silver crucible with a mixture
of nitre and caustie eoda ; or, better, they are oxidised by heating them with strong
nitric add ; and the solution, together with the insoluble stannic and antimonic acids,
is mixed with excess of caustic soda and evaporated to a small bulk, then transferred
to a sflrer emeible, evaporated to dryness, and ftised for some time at a red heat
llie fJBsed mass, consisting of arsenate, antimonate, and stannate of sodium, is disin-
t^liated by digestion in warm water, the contents of the crucible are transferred to a
beaker glaas, and the crucible is well rinsed out with a measured quantity of water.
Hie greater part of the arsenate and stannate of sodium then dissolves, while the
antimonate remains undissolved. But to effect complete separation, a quantify of
alodM)! of specific gravity 0*833, is added equal in bulk to one>third of the water used ;
&e mixture is left to stand for 24 hours and frequently stirred ; and the antimonate of
sodium, which has then eompletely settled down, is collected on a filter and washed,
first wilJi a mixture of 1 vol. of the same alcohol and 3 vols, water ; then with 1 voL
alcohol to 2 vols, water ; next with a mixture of equal measures of water and alcohol ;
and, lastly, with 3 vols, alcohol to 1 vol. water.

The antimonate of sodium, separated by this process, is digested in a mixture of
hydiodilorie and tartaric acids, which dissolves it completely ; the antimony ia then
preeim.tsted by hydrosulphuric acid, and its quantity estimated in the manner already
descnbed (p. 820).

The filtrate containing the arsenate and stannate of sodium is supersaturated with
hydrochloric acid, which throws down a bulk^ precipitate of stannic arsenate ; hydro-
sulphuric acid gas is passed through the liqmd till the white precipitate is completely
con Alerted into a brown mixture of the sulphides of tin and arsenic ; the whole is left to
stand till the odour of hydrosulphuric acid is no longer perceptible ; the precipitate is col-
lected <m a weighed filter ; ana the filtrate is heated for some time to expel the greater
part of the alcohol, then mixed with sulphurous acid, and a^ain treated with hvarosul-
^uric add, whereby a small quantify of sulphide of arsenic is generally precipitated.
This qnantitr of sulphide of arsenic beinff qmte free from tin, need not be added to the
mixed sulphides on the filter. These mixed sulphides are dried at 100^ C, their total
weight determined, and a known quiintity heated in a stream of hydrosulphuric acid
gas in the manner described at page 368. The residual sulphide of tin is then con-
verted into stannic oxide, and the sublimed sulphide of arsenic, together with the
small quantity separately predpitated, is converted into arsenic acid by treatment ■
with hydrochloric add and chlorate of potassium, and the arsenic precipitated as am-
monio-magnesian arsenate. (H. Rose, Anulyt. Chem. 1851, ii. 229.)

This m^od is long and tediou.s but gives accurate results. The most troublesome
pait of it is die disinte^tion of the fused mixture of the sodium-salts, which is very
hard. To obviate this inconvenience. Professor Williamson dissolves the predpitated
solidliides of the three metals in a mixture of sulphide of sodium and caustic soda,
ana mixes the solution with hypochlorite of sodiunf. The sulphides are thereby con-
verted into arsenic, antimonic, and stannic adds, which combine with the soda, and
Bun be Beparated bv treatment with dilute alcohol as above.

If the tnree metals are in the state of solid oxides, the mixture may be dissolved in
hydrochloric add, with addition of tartaric add, and the metals predpitated as
SB^^^des as before. If the metals are mixed in the form of an alloy, they may be
dtsBolved in aquA-regia, the solution mixed with tartaric add, then diluted, and pre-
cipitated in the^ same manner.

The method just described may, of course, be applied to the separation of antimony
fiom tin or arsenic alone. In these cases, however, the simpler methods above given
are preferable.

Bun sen has lately introduced a new method of separating arsenic from antimony
and tin, dependmg on the action of add sulphite of potassium on the sulphides of
those metals. When recently precipitated trisulphide of arsenic is digested with
a solution of sulphite of potassium containing excess of sulphurotis add, it dissolves
at first ; but on raising the heat to the boiling point, the liquid becomes turbid from
deposition of sulphur, which, however, is dissolved for the most part by continued
bouing. Sulphurous add is also given off, and the liquid contains arsenite and hypo-
anlphite of potassium :

2A^g^ + 16KH80« or 4KAsO» + 6K«8«0« + 38 + 780« + 8H»0
Add tolphite Ar>enit« of Hrpoiulphite
of potaMioiD. potaMium. orpoUsnum.

VouL BB

370 ARSENIC: ALLOYS.

The sulphides of tin and antimony are not affiseted bj acid sulphite of pulawiiiiiii
Consequently, when a solution of tnese three sulphides in sulphide of potaasium is
precipitated by a large excess of sulphurous add, the liquid digested for some tiine
orer the water-bath, and then boiled to e^>el the excess of sulphurous add, the sul-
phides of tin and antimony remain undiswlTed, while the whole of the aisenie piwPB
into solution, and may be precipitated fiom the filtrate by hydrosu^huzie acuL If
only sulphide of antimony is present in the vendue, it may l>e waahed with pure wat<er ;
but disulphide of tin thus washed is sure to pass through the filter ; henoe^ if tin is
also present, the residue must be washed, first with a saturated soLutioa of chloride of
sodium, and then with a slightly add solution of acetate of ammonium to remoiwe the
chloride of sodium ; after which it may be dried, the ammonium salt then yolatHisnns.
The washing cannot be performed with acetate of ammonium alone, because arsenic is
neyer completely predpitated by hydrosulphuric acid from a solution containing
acetate of ammonium, that salt being in &ct partly decomposed by hydroBulpbnric
acid into free acetic acid and sulphide of ammonium, which retains uie aisenie in
solution. Hence the liquid which runs through in washing out the diloride of sodium
by acetate of ammonium must not be added to the first wash-water Anntaittti^y the
arsenic (Ann. Ch. Pharm. cyi 8.)

Valuation of Arsenic Orea. — To ascertain the amount of metallic azseme that can
be obtained from an ore, the ore is gradually heated to redness in a retort or earthen
cylinder, either alone or, if it be a sulphide, with potash or ^uick lime. The greater
part of the sublimed arsenic may be collected on a thin iron plate rolled up and
inserted into the neck of the retort, and the rest on a cone of copper foil luted on to
the neck, a small aperture being left to allow the escape of gases. The sublinked
arsenic is then collected and weighed. Commercial arsenious add may be assayed in s
similar manner by heating it with 16 to 20 per cent, of charcoal.

It is seldom required to ascertain the quantity of arsenious add (anhydrous) thmt
an ore will yield by roasting. A more £requently occnrrinff problem is to determine
the proportion of pure anhydrous arsenious add contained m a crude product. If no
other yolatile substances are present, the amount of the pure anhydrous acid may be
determined by sublimation in a retort ; in the contrary case, the arsenious add may
be dissolyed out by boiling water, and its amount ascertained by weighing the rendne.

The quantity of pure sulphide which may be obtained from an ore, realgar, orpi-
ment^ arsenical pyrites, &c., is found by sublimation. (KerFs Sutienkvnde, Bd. lii.
!«• Abth. S. 2.)

rzCp AXAOTB or. Arsenides, — Arsenic unites by fusion with nK>st
metals, forming alloys which are generally brittle. With potassium and sodiumt^ it
forms alloys which giye off arsenetted hydrogen ^as when thrown into water. "With
iro7i, ffincj and tin, it forms brittle compounds ; with copper^ a white malleable alloy;
with gold and silver, grey brittle alloys ; with lead and with antimony, hard, brittle,
yery fusible compounds. It is introduced into the lead used in the manufactme of
shot, to preyent tailing, and cause the metal to run into regular globulea.

Metallic arsenides heated out of contact of air, either retain the arsenic altogeAer
or giye it up but partially. The alloys of arsenic and antimony are oomplet^y de-
composed by ignition at a moderate heat in an atmosphere of carbonic anhydride, the
arsenic yolatilising and the antimony remaining. When an alloy of arsenic is heated
in contact with the air, part of the arsenic is eyolyed as arsenious oxide, while the -
rest remains in the form of a metallic arsenite or arsenate. The arsenides of the
alkali-metals dissolye in hydrochoric or dilute sulphuric add, with evolution of
arsenetted hydrogen ; the arsenides of heavy metals are little, if at all, attadml by
any acid, except nitric acid or aqua-regia. By fusion with nitre, m^ailie arsenidea
are converted into basic arsenates ; when the arsenides of the heavy metals are fiiaed
with nitre and an alkaline carbonate or hydrate, and the ftised mass is treated with
water, the whole of the arsenic dissolyes as arsenate of alkali-metal, and the heayy
metal remains in the form of oxide f^ from arsenic Arsenides are not deoompoeed
by fiision with alkaline carbonates alone or mixed with charcoal, but if sulphur be
added, a sulpharsenite or sulpharsenate of the alkali-metal is framed, and the other
met-al remains as sulphide free fh>m arsenic.

Many metallic arsenides are definite compounds in atomic proportion, and in that
respect differ from the generality of alloys, which are mere mixtores of their constitiient
metab in indefinite proportions. In this respect, as in some others, arsenic resembles
the metalloids rather than the true metals. The distinction is, however, not absolute,
as many of the metals proper form with one another alloys constituted in ddlnite
atomic proportions.

Many metallic arsenides occur in natural minerals, e,ff. eopper^niekel, Ki*AS| ftkiis
nicJkel pyrites, NiAs, tesseral pyrites (Co; Ni; Fe) As, &c

ABSENIC: BBOMIDE— HYDRIDE, 371

jr, also called AUemmUUe, is foxaid. at Allemont; in the Ghalanche
Hbimtainfl^ depaitment of Isire ; also at Andreaabeig, Pmbraxn, &c ; occurring in
reinB in gneiss, together with natiye antimony, antimony ores, and arsenical cobalt. It
ioRDS fine-grained, spherical, and kidney-shaped masses, with uneven fracture. Specific
gnvity 6*2. Hardness 3*6. It is of a tin-white colour, opac^ue^ with a £iint lustre,
and in general appearance more or less resembling native arsemc It contains, accord-
ing to Kammdsbexg^s analysis, 87*9 per cent Sb to 62*1 As, corresponding to I at.
Sb : 2*6 at. As [Sb a 120*3], whence it would appear that the two metals are not
eomUned in at(nnie proportions, but isomorphously mixed.
The other metallic arsenides will be described with the several metals.

I iMPt AsBr*, is prepared by shaking arsenic in powder

into a rrtort fiUed with bromine vapour — the bromide of arsenic being distiUed from
the exeeas of arsenic ; also^ aooording to Nicklis (Compt r«id zlviii. 837), by treating

pohrerifled anenic with a solution of bromine in sulphide of carbon : it then ctystal-
linB from the solution. It forms a white etystalhne mass, which melts at 20°—
26^ C to a pale yellow liquid, boils at 22^ C, and in the fbsed state fumes but slightly
in the air : in contact with water it is converted partly into arsenious acid and hydro-
bromie add, paitiy into ozybromide of arsenic (p. 885).

I OV« Butter of Arsenic ; Caustic Oil of Arsenic^ AsCl'.
— This is the only known chloride of arsenic, and corresponds to arsenious oxide, As'O*.
It is produced when finely divided arsenic is brought in contact with chlorine — the
metal becoming ignited by the intensity of the combination. The same compound is
obtained by distilling a mixture of 1 part of metallic arsenic and 6 pts. of corrosive
sublimate ; also by distilling arsenious oxide with strong hydrochloric acid, or with
oonunon salt and sulphuric acid in excess. A colourless, oily, and very heavy liquid
is obtained, which is decoxnposed by water into arsenious and hydrocnloric acid ; if
the qfoanti^ of water is insufficient for complete solution, oxychloride of arsenic (p. 386)
is produced. It does not solidify even at —29*' C. Boils at 132^, producing a vapour
whose density is 6*3006 (Dumas). It evaporates in the air at ordinary temperatures,
prodncing white fumes of arsenious oxide. It is highly poisonous.

JjmmaidthMorids of Arsemc, As'H'N'Cl' » 2Asa*.7NH)' (H. Rose, Pogg. Ann.

62 Ui.), or 2(NriAs.Cl).4NHKILNH» (Pasteur, Ann. Ch. Pharm. Ixviii, 207).— Dry
ammonia sas passed into chloride of arsenic is rapidly absorbed, forming a white solid
body, which is soluble in water and in alcohol, and crystallises therefrom without
alteration. It is decomposed b^ heat» and according to Pasteur, ammonia is first given
oA^ and then the residue volatilises completely, yielding a sublimate, in which cubes
of sal-ammoniac can be detected by the magnifying glass. It is decomposed by hot
water, amriionia being evolved, ana arsenious acid and sal-ammoniac remaining in
solution. When cold water is poured upon it, it becomes heated, gives o£f ammonia,
and fimns a adution, yielding by spontaneous evaporation six-sided tables, which
may be regarded as a compound of dbloride of arseiuunmonium with arsenious oxide

and water, 2(lO[As.ClVAs*0'.4H'0. This compound treated with strong aqueous
•nunonia is converted into a hard mass of long six-sided tables, consisting of mon-
ammanie arseniie, As(NH*^0', which quickly ^composes in solution, and still more
quickly in the solid state, giving off the greater part of its ammonia.

^^^— "^V WMJUO'MXDM OVv AsF", is poduced by mixing 1 pt. of fluor-spar,
|M*M*<i by ignition, with 1 pt of arsenious oxide and 3 pts. of strong sulphuric acid
tn a Isadaii retrnt^ and heating the mixture tUl it boils. It is a transparent, colour-
leas Uquid, of specific ^vity 2*73, very volatile, boiling at 63^ C, and filming strongly
in the air even, at ordinary temperatures. The vapour is about four times as heavy as
atmo^>heric air. A drop of tlie liquid coming m contact with the skin evaporates
almost instantly, but nevertheless produces a painful wound, which suppurates for a
long tame like a bum. It attacks glass but slowly in a close vessel, but in contact
una moisture^ it is decomposed, yi^ding arsenious acid and hydrofiuoric acid, which
eomdss the glass. With water, it foims a dear liquid, which corrodes glass, but
searedy attacks zinc or tin.

AMMMMWOf SSJMUCDa CNPa Arsenic contains two compounds with hydrogen,
one soUd and the oUier gaseous. The solid arsenide of hydrogen is obtained by passing
an deetrie current through water, the negative pole being formed of metallic arsenic ; or
by dissolTing arsenide of potassium or sodium in water. It is a brown powder, which
cfTolves hydrogen when heated in a close vessel, and bums when heated in the air
(Davy). From Soubeiran's analysis, it appears to be AsH*.

Tbihtdbidb of Absskic, Absbnbttbd Htdboobit, AsH*, a gas analogous
in composition to ammonia, is obtained : — 1. By dissolving arsenide of potassium in

BB 2

872 ARSENIC: HYDRIDE— ORES.

water, the solid azsenide being formed at the same time. — 2. By dissohriiig an alloj of
1 at. arsenic and 3 at. sine or tin, in hydrochloric or dilute solphurie add :

AsZn' + 3C1H « AbH* + SClZn.

3. By dissolTing zinc in hydrochloric or dilate sulphuric add containing
add (p. 361.)

AsW + 12Zn + j JeS%H» - 2AsH» + 8HH) + j J^O^^

4. By dissolring zinc, tin, or iron in aqneons arsenic add or in a nuztnre of that sad,
with hydrochloric or solphurie add :

2A8H*0« 4- 16Zn - 2AbH* •»- 8ZnK).

This last mode of foimatum was first given by Scheele^ and afterwards denied 1)7
Fischer (Fogg. Ann, iz. 261), who stated that aqneons arsenic add, if quite Heo
from anemone add, evolres nothing bnt hydrogen wnen treated with zincr Gmeli n,
however, obtained arsenetted hydrogen with perfectly pore arsenic add and xiifte.
(Handbook, ir. 264.)

6. By the electrolysis of arsenions or arsenic add. (Bloxam, p. 361.)

The gas obtained by dther of the above processes is never purp, bnt always miwrxl
more or less with free hydrogen. It may be collected over water, but the moAt
scmpnlous care most be taken uiat not the smallest quantity be inhftltfid, as it is cxoea-
mvely poisonous, and has proved fatal in more than one instance.

Araenetted hydrogen is a colourless gas, which liquefies at 30^ CL, bnt does not
solidi^ even at 110^ C It has an extremely repuldve odour, and even when lar^gely
dilutea with air, produces nausea, giddiness, and oppression. Small animala mre
instantly killed by it It does not redden litmus. Its spedfic gravity, according to
Bumas, is 2*695 (air » 1). One volume of the gas contains 1| voL hydrogen and ^ tqL
vapour of arsenic : [f . 0*0693 •(- J . 10*39 i- 2*7011.

Arsenetted hydrogen is slightly soluble in water. It does not combine dther ^iritli
adds or with bases. It decomposes the solutions of many of the metsls which az«
predpitated by hydrosulphuric add, its hydrogen alone being oxidised, and tbe
arsemc predpitated in combination with the metu. From a solution of solphate of
copper, for example, it throws down arsenide of copper, AsCu' :

2AsH« + 8S0*Cn» « 3S0<H« + 2AsCu».

When a mixture of this gas with free hydrogen is placed over a solution of sulphate
of copper, the arsenetted hydrogen is completely absorbed and the hydrogen remsdiis.
From the salts of silver, gold, and platinum, arsenetted hydrogen predpitates tbe
metals, and is converted into arsenious add, which remains in solution, e. g, :

6N0«Ag + AsH» + 3BP0 = 6Ag + 6N0«H + AsBPO.«

Nitrate of Nitric Araenloiu

■ilver. add. add.

Arsenetted hydrogen is decomposed at a red heat into free hydrogen and metallie
arsenic. It bums in the air with a bluish-white fiame, quite different in appearasee
from that of pure hvdrogen, forming water and arsenious add, which rises in white
smoke, and is deposited in a white crust on a cold bod^, such as a piece of pcfroelain
held just above tne flame ; but if the porcelain be held in the middle of the flame a
to cool it partially, then the hydrogen is alone bumt^ and the arsenic, being
combustible is deposited on the porcelain in metallic spots (p. 362). This e£RBCt is ^
cisely similar to the depodtion of soot on a glass rod or other cold body held in tlie
flame of a candle.

See AsflDnc, Sulphedbs of (p. 386).

[Of lOSXBB OV« AsP. — Arsenic and iodine unite when gently heated
together, the combination bdng attended with condderable evolution of heat^ By
distilling 3 pt& of iodine with 1 pt of metallic arsenic, in a retort having its bnlb
immersed in a sand-bath, the iodide is obtained as an orange-coloured crystalline
sublimate having the lustre of gold. It may also be prepared, like the bromide, by-
treating metallic arsenic with a solution of iodine in sulphide of carbon. It dissolves
in 3*32 pts. of boiling water, and the solution, if boiled down, leaves pure iodide of
arsenic ; but, if left to cool slowly, depodts crystals of a compound of arsenious oxide
with oxyiodide of arsenic (p. 368). The iodide may be reoTStalliaed from boiling
alcohol, and is then obtained in shining laminie of a fine brick-red colour. Iodide of
arsenic has been used in the treatment of cancer.

^9 XXTMKL or. An old term for the alkaline snlpharsenitea (pi 388X
;0« OBB8 Ol*. (pp. 360, 370.)

ARSENIOUS OXIDE. 873

dXXBMi or. Anenie fatma two veU-defiaed oxides, tis. the 7W-
oatUemJrdmum* Oxide, AifO; or AsC^, axtd the Pentoxide or Artenie Oxids, Am*0^,
or AmO^. The black film which forms on the snz&ce of the metal when exposed to the
air is hj many sapposed tobe a snboxide, but it is more probably a mixture of metallic
arsenic with tiie tnoxide.

Aksbxious Oxxdx (or Akhtdbidb), AsK)*; in the hydrated state, Abssniovs
AciB. — ^This oompoond occurs natiye in the min«»l arsenite orarsenoiite (a. v.) which
fisnns capiBaiy crystals inYesting ores of nickel, cobalt^ &c It is formed when arsenic
•volatilises in contact with £ree oxygen, as when the metal is heated in a glass tube
throu^ which a cuixent of air is passing.

On the large scale, azsemous oxide is obtained as an accessoiy product in the roasting
of arsenical ores of tin, cobalt and nickel, and as a principal product in the roasting of
arsenical pyrites. The ores are sometimes roasted on the hearth of a reTerberatoiy
fnrnaoe, wnere they are in direct contact with the flame, more generally in muffles
which are sanounded by the flame but preTfint it from touching Uxe material. The
latter method inTolves a larger consumption of Aiel, but yields a purer product^ inas-
much as when the flame comes in contact with the ore, the arsenious oxide produced
by the oxidation becomes mixed with carbonaceous matter, which, in the subsequent
sublimation, reduces a portion of the arsenic to the metallic state, and giyes tlie product
a grey colour.

At Beiehenstein, in Silesia^ arsenious oxide is prepared firom arsenical pyrites. The
ore reduced to powder, is roasted in a muffle-fiimace, and the Tapour of arsenious
oxide is made to pass into a condensing chamber, divided into partitions, where it is
deposited in the pulrerulent state, as crude arsenic or poison-flour (^Gi/tmehl). This
pfodnct is refined by sublimation in cast-iron pots, the tops of which are contracted
into cones, and terminate ia pipes which also pass into a condensing chamber. Lastly,
the refined arsenious oxide is again sublimed at a higher temperature, and collects m
the imper part of the subliming yessel in the form of a glass (yitreous arsenious
axidel

At Ribas; in Catalonia, arsenious oxide is obtained from arsenical pyrites by roasting
in a reyerberatory furnace without muffles ; in other respects, the series of operations
is similar to that just described. At Andreasberg, in the upper Haiz, ai^entiferous
natiye arsenic is roasted to extract the silver, and arsenious oxide is obtuned as a
seoondaiy product It is also produced in large quantity in the roasting of tin
ores and cobalt ores at Altenberg in Saxony, and of tin ores in Cornwall. ^See Ure^s
JHctumary of Arts^ Manufaciwrts, and Mines, i 185 ; Kerl's HiiUtenkunde, iiL !*• Ab-
theilung, S. 14.)

Properties. — Arsenious oxide is a white solid, which occurs in two crystalline forms
and likewise in the amorphous state. — 1. Amorphous^ vitreous or glassy arsenious
oxide is produced, when the vapour condenses on a surface whose temperature is but
little below the volatilising point of the oxide, so that before solidifying it passes
through the semi-fluid state. It is transparent when first prepared, but gradually
becomes opaque, and passes into the crystalline state. Its s^^cific gravity, according
to Guibofart^ is 3*7386. — 2. Octahedral arsenious oxide. This variety is produced by
sublimation when the vapour is cooled so quickly that it solidifies at once, without pass-
ing through the semi-fluid state; A hot saturated aqueous solution deposits the
oxide in regular octahedrons on cooling. Vitreous arsenious oxide is transformed into
the oetahedral variety by keeping, especially in contact with the air, and also by
sohition in water or hydrochloric acid. When 2 or 3 pts. of the vitreous oxide are
dissolved in a mixture of 12 pts. of fuming hydrochloric add and 4 pts. of water,
and the solution is left to cool sloidy, the arsenious oxide crystallises in
transparent octahedrons, the fbrmation of each crystal being accompanied by a flash
of liplht (H. Bose). The spedfic gravity of octahedral arsenious oxide is 2*695
(O uibo urt). — 3. Swkt Shombie Arsenious Oxide. This variety, which is isomozphous
with native oxide of antimony, is occasionally obtained by sublimation (Wohler),
also, aooording to Pasteur, when a boiling sohition of potash is saturated with arsenious
acid and left to cooL It is converted mto the octahedral variety by sublimation or
by solution in hot water.

Anenioas oxide volatilises at about 218^ C, forming a colourless vapour of specific
igrmtity 18'85. The vapour is perfectly inodorous, provided the oxide has not been
Seated in contact with charcoal or other reducing agent. The vitreous oxide may be
fused beCbre it volatilises to any considerable extent; but the crystallised oxide
sublimes befine fusion. Under pressure, the oxide may be melted to a glass.

Arsenious oxide dissolves but sparingly in cold water, more readily in boiling water,
the vitieoDs oxide dissolves more readuy than the crystalline variety. A hot saturated
contains 1 pt. of the oxide or anhydrous acid in 10 or 12 pts. of water, and

B B 3

374 ARSENIC: OXIDES.

on cooling deposits th^ greater, portion, leaving a solution eontnoiiiff 1 pt of the
anhydrous acid in 80 pts. of wat«r. The statements of dii&rent mbuhb le^uding
the solubility of anenious add in water differ oonsid»ably, the diaoepsocy tHobsUy
arising ttom the simultaneous oocuraenoe of the Titzeous and crystaUine mowrtias
in the acid submitted to experiment (Gm. iv. 257). Ko definite hydrate of ansniott
acid appears to exist The aqueous s(Uution is transparent and oolouilesi, and slig^tlj
reddens litmus. (For its behaviour with hydrosulphurie add, nitrate of ohfvr, and
other reagents, see page 861.)

Anenious oxide dissolves in hot dilute adds more readily than in water, but aepantes
out completely on cooling, without forming any definite compouhd. It has therdbn
little or no basic power. With tartaric add, however, it forms a potaasic dcabile nit
analogous to tartar-emetic. (See Ta&tabio Acm.)

It dissolves in alkalis, forming aisenites of alkali-metals.

It is nearly insoluble in alcohd, quite insoluble in ether.

Arsenious oxide, whether in the dzy state or in solution, is one of the most violeat of
the acrid poisons, a dose of two or three grains being certain to cause death, qbImi it
be veiy speedily ejected by vomiting or rendered innocuous by conversion into an
insoluble compound. Nevertheless it appears to be poamble, by oomnieacing with
small doses and gradually increasing them, to accustom the human body to soatain
without ii\juiy, doses of 4 grains or even more ; and it is moreover stated, apparentlj
on good authority, that araenio thus taken produces a plun^> and healthy appeaianet
in Uioee who use it, and especially increases the power of the respiratorv otffai, ani
consequently facilitates mountain-climbing under heavy burthens. The Tpoleie
peasantry are said to swallow arsenic in oondderable quantities fat this poipoK.
Those who are accustomed to taking arsenic in this wa^, are also said to espmeuBt
great depresdon and loss of strength if they discontinue it.

Arsenious add in small doses is much used in medicine, chieflj in eases of dda-
disease. The form in which it is most frequently administered is that of Ftwle^i
solution, which is an arsenite of potassium.

The best antidote to poisoning by arsenic is hydrated aesquiaxide of inm, vfaidh,
when administered in excess, converts the arsenious add into a bade ferric anenit^
perfectly insoluble in ^ater and in the fluids of the alimentary canaL It may be
prepared by precipitating a solution of ferric chloride or sulphate with ainin(wiia> and
wadiing by decantation, and should then be kept under water, because when dry, ito
power to lay hold of arsenious add is very much diminished. It is most efficaoooi
when recently precipitated, the absorbing power being somewliat diminished, eren hj
keeping under water (Bun sen and Bert hold; " Bas Eisenoxyd ein Gegendft dff
arsenigen Saure." Gottingen, 1834). Still more efficadous, according to Foutf,!! a
mixture of hydrated ferric oxide with magnesia, obtained by predpitating a adatioBof
ferric chloride or sulphate with excess of calcined magnesia. It snould be prepaiad at
the time when it is wanted, and may be used at once, without washing; the aohiUe
magnedum-salt produced by the reaction being rather beneficial than otherwise, inaa*
much as it exerts a purgative action. When ammonia is used as the predpitant, the
washing cannot be dispensed with, because arsenite of iron is somewhat sdalde in
ammoniacal salts. The magnteia used for predpitating the ferric hydrate most aot
be very strongly calcined. Magnesia itself is likewise capable of abstzacting aiaemoos
acid from solution, and forming an insoluble compound with it ; but Ibnic hydrate is
more powerful in this respect, and the mixture of the two prepared in the nuumer jot
mentioned, is more efficadous than dther, probably because the ferric hydn^ i^
sroead oTer the surface of the partides of magnesia in a state of fine divuBoa
(Handw. d. Chim. 2*« Aufl. ii 294.)

Arsenious oxide acts both as an oxidising and as a reducing agent. It partially d^
oxidises many compounds rich in oxygen, e,ff. nitric add, manganic add, dbroMe
acid, hypothlorous add, &c., being itself converted into arsenic oxide or add. It
quickly reduces gold ftom the solution of the trichloride. Botasdufny ckarcod, ao^tim,
sufphur, phosphorus, and dnc deoxodise it at a red heat, separating metallic anede.
Distilled with acetates, it yidds cacodyl, a compound of 1 at. arsenic with 2 at methji,
As(CH')', which may be recognised by its peculiar and intoIeraUe odour. When
vapour of arsenious oxide is passed over red-hot ItTne, part off it is resdved into
metallic arsenic, which sublimes, and arsenic oxide which unites with the lune, fSoramv
an arsenate (Wollaston), while another portion, greater as the heat is less, umtei
directly with the lime, forming an arsemte (Simon). Heated with carbonate of
potasdum, it likewise yidds metallic arsenic and an arsenate (Qay-Lusaae). ha
an oxidising agent, arsenic oxide is used in the manufacture of glass, for the pmpoee
of converting protoxide of iron into sesquioxide, which yields less hi^bly ookmed {^Maea
than the protoxide.

Abseiotes. — ^Arsenious add unites with bases in several proportions, but the aalti

ABSENITES. 375

■re not fciy staUeb and Iutd been but little examined. Thoee whose oompoeition u
KAbO* or ICO.Aji'O', are generally regarded as neutral ; and besides these there are
bask anenites eontaining WAsHy, or 2MH).As'0', and M'AsO", or 3M'0.As*0*, besides
add aalta.* Arseniooa oxide dissolyes in caustic potash or wda, but does not neu-
tralise the alkali ; the concentrated solutions are aecomposed by the carbonic acid in
the aiz^ and yield, after a while, yery large and well formed crystals of anhydrous
arsenious add. The acid dj^solves in ammonia more readily than in water, and
remains finee from ammonia when the solution is eraporated. 2>tme, baryta^ and stron-
/M, diaaolTe when boiled with water and excess of arsenious add, and on adding lime-,
bazrta-, or strontia-water in excess to the solutions, basic salts are predpitated in white
flocka. These pred^itates dissolve in acids and in ammoniacal salts : hence arsenious
add eannot be precipitated by the alkaline earths from solutions containing ammo-
niacal salts. The other arsenites are insoluble in water, and are obtained by predpi-
tation. They dissolre in hydrochloric add, and some of them in acetic acid, also in
solphate, hydrodilorate, and nitrate of ammonium.

Solutions of the alkaline anenites give a light green predpitate with eupric $alt$f
egg-yellow with nitrate oftilver. — Eyarastdphurie add produces no predpitate unless
a stronger add is present in excess ; but all arsenites when dissolyra in hydrochloric
add giye a predpitate with hydrosulphuric add; and if the metallic base of the
anenite is likewise predpitable by hydrosulphuric add, a compound metallic sulphide
may be produced.

Most arsenites are decomposed by heat : some gire off arsenious oxide, and leare the
base in the form of oxide : but the anenites of the alkali-metals and the alkaline earth-
metals, give off metallic arsenic and leave a salt of arsenic add (fiAsH)* » 3AbK>* +
As*). Arsenite of silver gives off arsenious oxide and leaves a mixtnre of metallic
■liver and arsenate of silver; arsenite of lead alone withstands a red heat without
decompontion, and arsenite of magnenum is but imperfectly decomposed (Simon,
Pogg. Ann. xL 436). — ^Arsenites heated with charcoal give off metallic arsenic

Arsenite of Ammonium^ l^^AsO*, or (KH^)K). As'O*, according to Pasteur ;
(NH^/AsH)*, or 2(NH*)*0«AsK)*, according to Stein, is produced, accordmg to Pssteur,
when very strong aqueous ammonia is poured upon arsenious oxide, and forms a
bard mass composed of microscopic six-sided tables belonging to the triznetrie system.
It exists only m contact with ammonia, quickly giving off ammonia in contact with
the air. It forms a ydlow predpitate witn silver-salts, the solution turning add. It
is iosolnble in alcohol and in ether.

Arsenite of Antimony. -^Produced by digesting metallic antimony with
■queoQs arsenic add, and is predpitated on diluting with water. It may also be ob-
tained as a transparent, fused, vitreous mass, by heating metallic arsenic with anti-
monic oxide.

Arsenite of Barium, BaAsO*, or BaK).As*0', is obtained by mixing a solution
of chloride of barium with add arsenite of potassium, separating after a few hours as
a gelatinous mass or in dendritic ramifications. In this state it is very soluble in
water, but becomes sparingly soluble after drying : the li(juid decanted from the jelly
likewise yields the salt by evaporation, as a heav^ sparmgly soluble powder. The
gelatinous salt is probably a hydrate. A salt containing 2BaK).As'0' -»- 4H*0 is ob-
tained, accdMing to Stein, by dropping baryta-water into aqueous arsenious add, as
long as a predpitate continues to form, and washing with dilute alcohol. It gives off
2 at. water at 100^ C, and the rest at a higher temperature, arsenic, however, voktilising
at the same time.

A ooneentrated solution of arsenious add is immediately predpitated by baryta-
water, a very dilute solution after some time only, or not at aU (L. Gmelin). Ajse-
nite of ammonium predpitates solution of chloride of barium after a while.

Arsenite of Calcium. — The several arsenites of potasdum, added to solution
of chloride of osldum, yield precipitates, but not of constant compodtion (Filhol).
The nentesl salt, CaAsO', is obtained, according to Simon, by precipitating chloride'of
calcium with ammonia saturated with arsenious add ; the predpitate is increased by
mAAing excess of ammonia, but dissolves partially when washed with water. When,
on the other hand, an aqueous solution of arsenious acid is mixed with excess of lime-
water, a white heavy powder (2CaK).AsK)', with water) is predpitated, which is very
Httle soluble in water, somewhat more soluble in the presence of ammonia-salts, or of
dihnnde of potasdum or sodium. According to Stein, the predpitate thus ob-
tained is a mixture of several bade salts, but on adding soffident arsenious add to
disBolye part of it, the reddae consists of 3CaK).2AsK)* + 3H'0 ; this salt gives off
1 aL water at 100^ C, the rest at a temperature at which decomposition begins.

• ir O a 8, the fonnalje are MO.AsCf^, iMO.Aitfl, and iMO.AsO^ rvapeeUvelj.

B B 4

376 ARSENIC: OXIDES.

According to KuHn (Jaliresb. d. Ghem. 1652, 379), a boiling solnlioii of wnaaam
acid add^ to excess of lime-water throws down the salt^ SCa^O JbW, or Gt^AM)*.

Arsenite of Cobalt, 3CoK).2A8*0* + 4HH), is obtained by quicUj mixiBg
arsenite of potassinm with a solution of chloride of cobalt containing a luge ezoeag of
sal-ammoniac.

Arsenite of Copper , Cu*As*0*,'or 2CuK).AsK)*, is obtained by precipitatiag a
salt of copper with arsenite of potassium, or with arsenious acid and a sufficieiitquntity
of ammonia to neutralise the acid present (p. 861). It is a light green preebitato
(Scheele's green), which dissolves in excess of ammonia without colour, yieldog a
solution of arsenic acid and cuprous oxide. Arsenite of potassium contahung exces
of alksli dissolves it readily, with blue colour, but the solution quiddy. deecompoM
into arsenate of potassium and cuprous oxide. Vapour of arsenious oxide passed ora
red-hot cupric oxide does not combine with it-.

Aceto-Arsenite of Copper. 3CuAsO*.G*H'CuO'. JSchweinfurt Green, or Intend Green.
— This compound, the preparation of which is given at page 16, ia much used as a pig-
ment, on account of its splendid green colour. A great deal of needless alarm hai
latelv been excited about the supposed deleterious ^ects of this pigment It is ex-
tensively employed for staining wall-papers, and persons inhabiting rooms thaa papend
are said to have had their h^th seriously deranged by the areenical fwmes erolTed
fiom it I Now it is utterly impossible that arsenic should volatilise from saeh a eom-
pound at ordinaiv temperatures : it does not decompose at any tempeiatare bdov
redness. The only way in which danger could arise &om the use of paper stained
with an arsenical colour, is that partides of the compound might be broshed df in
in dusting the paper, and thus become mixed with the air of the apartment; bat it is
not in Hob way that the supposed accidents are said to have occuned; the panic has
arisen from a mistaken notion as to the volatility of the arsenic That the use of tbe
pigment is not really dangerous may be safely inferred from the fact that no bad
effects are experienced bv the workmen engaged in its manufiacture. (See Un't
Dictionary of Arts, Manufacittres, and Mines, L 167.)

Arsenite of copper forms a similar double salt with hutyrate of copper.

Arsenites of Iron. — There are several basic ferric arsenites. "When recent^
precipitated ferric hydrate is digested with a concentrated solution of arsemoos acid,
in such proportion that the quantity of anhydrous ferric oxide present is equal to ten
times the weight of anhydrous arsenious acid, the acid is completely removed from tbe
liquid. With a smaller proportion of ferric oxide, the precipitation is nearly thoogh
not quite complete. The products formed are basic arsenites containing 3Fe*0.'As'0|,
&c, from which part of the arsenious acid may be extracted by water. It is ^
power possessed by hydrated ferric oxide of removing arsenious acid from a solntioD,
which renders it so useful aa an antidote to arsenious add (p. 374).

Arsenious acid, or arsenite of potassium, forms with ferric acetate an ochie-yeDov
precipitate, which dries up to a brown mass containing 4FeH>'.As*0* -t- 5A^ and
when heated gives off water and the greater part of the add (Bunsen), the whole, a^
cording to Simon. Water removes part of the arsenious add ; strong mineral acida
dissolves the salt completely. Ferric sulphate or chloride is not predpitated by fre^
arsenious add : but gives with arsenite of potassium, according to Guiboort, a zosty •
brown precipitate, containing when dry, 2Fe^0'.A8K)' + 7H'0. According to Damoor,

lining 2Fe*0».As«0» + 7H«0, is obtained by oxididng
ferrous sulphate with aqua-regia, neutralising with ammonia, and predpitatingby soda*
ley, which has been saturated at the boiling heat with arsenious add and fre«i from
the excess of that add bv cooling. It is soluble in caustic soda, and the sdution,
evaporated to dryness, yields a red mass perfectiy soluble in water.

Ferrous Arsenite, 2Fe*0.AsH)', is obtained by mixing ferrous sulphate witii a stAyim
of arsenious add in ammonia, as a greenish white predpitate, which becomes ocbre-
yellow on drying. The non-oxidised compoimd is soluble in ammonia.

Arsenite of Lead.— The neutral salt, Pb*O.Afl«0*, or PbAsO* is obtained by p-
cipitatinff neutral acetate of lead with acid arsenite of potassium, or with axseniooi
add (Filhol), or, according to Berzelius, with ammonia which has been saturated vitb
arsenious add while warm ; the predpitate obtained by the latter process contains
water, becomes strongly electrical by friction, and when heated gives off some of its
acid and water, and melts to a yellowish glass. Neutral arsenite of lead is somevbat
soluble in water, insoluble in potash, but soluble in soda. The tetraplumhic M,
Pb* As*0», or 2Pb«0. As«0», is formed, according to Filhol, by predpitating neutral acetate
of lead with basic arsenite of potassium, or, according to Beitelius, bj predpitatins basic
acetate of lead with an ammoniacal solution of arsenious add. It is a white byorated

{

ARSENITES. S77

powder, insohiUe in mtet and in anunonia-saltB, melting to a yellowiah glass when
healed. According to Simon, it ia obtained by paaaing the yaponr of aneniona oxide
over red-hot oxide of lead, aa a sulphnr-yellow, easily ftisible glaaa, which sustains a
considerable degree of heat without decomposing. A triplumbie saltf 3PbH).A8*0*,
or Pb'AsO', is obtained by precipitating basic acetate of lead with a boUing solution
of aisenioos acid. (Kuhn.)

Arstniie of Magnesium, — Calcined magnesia^ boiled with arsenious add, takes
up a portion of it» but not in any definite amount. A precipitate of xmcertain com-
position ia obtained by mixing sulphate of magnesium with acid arsenite of potassium,
and heating. A sohition of sulphate of magnesium is not precipitated by aqueous
aiaenions acid ; but on adding a small quantity of ammonia, a copious precipitate is
fonned which, according to Stein, has, after drying over sulphuric acid, the composition
Mg^AsO*, or Sltfg'O. AsH)*. It is insoluble in ammonia, but dissolves in a large excess
of sal-ammoniac (H. Bose.)

Aratniie of Manganese, SMn'O.SAs'O* + 5HHD, is obtained, by treating a
man^anous solution with arsenite of ammonium, as a rose-coloured precipitate, which
oridises rapidly in the air, gives off 1 at. water at 100^ C, and at a higher temperature
giyes off arsenious oxide and metallic arsenic, leaving a residue of manganese and
mai^anoiia arsenate.

Araenites of Mercury, — ^The mercurie salt is obtained, by preeipitoting mercuric
nitrate with arsenious acid, as a white powder soluble in nitric acid. It dissolves also
in areenite of potessium, and if the solution contains excess of potash, a black deposit
of reduced metal is immediately formed. The merewrous salt is obtained by double
decomposition, or by digesting mercury in arsenic acid, as a white precipitate soluble
in nitne acid.

Arsenite of Nickel, — ^The salt 2NiK).As'0' is precipitated on adding arsenite of
potassium to a nickel-salt. A less basic salt, 3Ki*0.2A8*0' + 4HH), is produced,
according to Girard (Compt. rend, xxxiy. 918), by quickly mixing a solution of
chloride of nickel containing a large excess of sal-ammoniac, with arsenite of potassium.
It is a greenish precipitete, which gives off 10*3 per cent. (4 at) water at 110^ C.
When heated in ihe air, it first gives off its water, and then yields a sublimate of
arsenious oxide, leaving yellow infusible arsenate of nickel :

8Ni«0.2AB«0« + 0« « 8Ni«0AsH)* + As'O*.

Arsenite of nickel dissolves with violet colour in ammonia. It is converted by nitric
add into arsenate ; by hydrochloric add into arsenious add and chloride of nickeL

Arsenite of Potassium, — The neutral oimonopotassic salt^ KAsO^ or KK).As*0',
is obtained, by boiling the add salt for some time with carbonate of potassium, and
agitating the roddual salt seyeral times with alcohol : it then remains as a ^rrupy
mass (PasteurX Filhol was not able to prepare it pure. An acid salt, KK).2AsH)' +
2HK>, is obtained, by boiling potash-ley with excess of arsenious add, whereby an alka-
line liquid is produced,»whidi gives wiUi silyer-salts a yellow predpitete, 2AgK) AsK)',
mixed witii arsenious add, the liquid at the same time becoming add. On mixing the
alkaline liquid with alcohol, it becomes thick and turbid, deposits after a few days
right rectangular prismatic crystals, adhering to the sides of vessel and alter a longer
time solidifies completely to a saline mass. The salt ^ss off I at. water at 100° C,
whence it should perhuis be regarded as 2KBAbH)* + B*0 (Pasteur). The basic or
tetrapoiassic salt, 2K*0.AsH)', is obtained by mixing the neutral salt with excess of
potash-ley and predpitoting by alcohol It is very soluble in water, and jields with
sSrex^^alts a yellow predpitete of the diargentic salt> 2AgfO As'O', the liquid remain-
ii^nentraL

Arsemts mth Iodide of Potassium. — A solution of iodide of potassium yields with
arsenious add or arsenite of potassium, a predpitete, 2KI,3AsH)', which is sparingly
soluble in cold water, dissolves in 19 pts. of boiling water, and decomposes at 316° C,
when heated with sidphuric add (Emmet^ SilL Am, J. [|2] xviii 583). By passing
carbonic add gas into a solution of this salt in a small quantity of boiling water mixed
with 8 or 4 times ite volume of hot alcohol, and evaporating the resulting syrupy
liquid, a OTstallised compound is obtained, consisting of 2EI . 3(K*0.H^AjbK)'),
Off 2(KL3KAsO') + 3H'0. This salt is soluble in water and in alcohol, and reacte
with metallic salts like a mixture of iodide and arsenite of potassium. Strong sul-
^(uric add decomposes it, forming a red or yellowish predpitete of arsenious iodide.
The hot saturated solution of this salt deposite on cooling, nodular masses, or, when
carbonic add gas is passed throiu^ it, a white powder, consistiiig of the salt
2BX(K*OJtt«0.8As«0»), or 2(KI.KHAs«0<).As"0«, which is roarin^y soluble m
water, and when heated in a narrow glass tube, gives off vapour of water and metallio

878 ARSENIC : OXIDES.

•nenie, together with anenions ozida No iodine is giTen off onleM the air bai
Moees to the Belt. (K HarmSi Ann. Ch. Phann. xcL 871.)

Ars$nite of Silver.^TheUtrafyentic salt, 2AgK)JL8*0* » Ag^AsK)*, is ibnned
MB a yellow precipitate on treating solutions of silTer salts with alkaline anenites
(pp. 861, 375). It gradoallj turns duk grey when exposed to the air, blaekens if exposed
to light When heated, it gives oft, according to Simon, first water, then azBenioiB
oxide, and leares a mixture of arsenate of silver with metallic BilTer.

Another arsenite of silver is obtained, according to Filhol, as a light yellov pn-
cipitate on adding ammonia saturated with arsenious add to an ammoniaeal aohtion
of nitrate of silver. Between 140^ and 160° C. it blackens suddenly, without Iom of
weight, and at a hisher temperature melts and gives off arsenious oxide.

It is easily soluble in acetic acid (whereby it is distinguished from phorohate of
silver) ; soluble also in potash. The latter solution is not precipitated by cfaloiide of
potassium, but, on the contraiy, is capable of dissolving an additional qautitj of
chloride of silver. It dowly aeposits metallic silver, while arsenate of potanom
remains in solution. When a solution of chloride of palladium or platinnm is mixed
with arsenite of potassium, and then with arsenite of silver and potassiiun, tbe
platinum or palladium separates quickly in the metallic state. (Bey nose.)

8e8qid-argentie Arsenite^ 3Ag'0.2A8'0', or AgK).4(AgAsO'), is pzodnoed as a irliite
precipitate, with evolution of ammoniA, when nitrate of silver, mixed with a laij^
excess of nitrate of ammonium, is added by drops to arsenite of potassium. It u
blackened by light, dissolves in ammonia and in excess of arsenite of potassium, and
when heated blackens, yields a sublimate of arsenious oxide^ and leaves a fiiuble
residue of a fine red colour. (£. Harms and others.)

Arsenite of Sodium, — According to Pasteur, the sodium-salts of arsenioos leid
correspond exactly to the potassium-aalts, excepting that the add salt does not 071-
tallise. Filhol did not obtain the neutral salt m a state of purity.

Arsenite of Strontium, SrAsO' + 2HH). — Strontia-water is not precipitated
by aqueous arsenious add in any proportion, even on boiling (Gmelin). Chloride of
strontium is predpitated by arsenite of potassium, but omy after some days. The
predpitate gives off one-fourth of its water at 100*^0.

Arsenites of Tin. — Both the tftonntc and the sto»9u>tw salts are white precipitates;
the former is difficult to fuse.

Absbnic OxiDB, As*0*, or AsO^. In the h^drated state, Absxkic Acid.— This
compound is produced by oxidising arsenious oxide or arsenious acid with nitric add,
aqua-regia, hypochlorous add, or other oxidising agents. — 1. When 4 parts of anemooi
oxide are gradually added to 3 pts. of nitric add of specific gravity 1*36, the mixtuR
becomes hot, and after 24 hours ^elds a syrupy liquid like strong oil of vitriol, oousiat-
ing of arsenic add, still containing a litUe arseuous add, which may be completely
oxidised by tlie addition of a smaU quantity of nitric add. This process is used for
the preparation of arsenic add on the laice scale (£. Kopp).— 2. Four parts of
arsenious oxide are heated with I pt of hy£ochloric add, 12 pts. of nitric add an
graduaUy added (Mitscherlich), and the resulting solution is evaporated to a spvp.
Both the oxidation and evaporation must be performed under a chimney hsTing a
good draught, because part of the arsenic is converted into chloride, which escapes in
vapour. — 8. Arsenic acid is also produced, together with hydrochloric add, by piOiBg
chlorine gas into aqueous arsenious add.

Arsenic add forms three hydrates analogous to those of phosphoric add, vis. :

Monohydrate . . H«OAs*0», or HAsO« « (-^*^|o»

Dihydrate . . . 2HK).AsK)», or H*AsH)'- ^^^'^^l^*
Trihydrate . . 3H«0.AsW, or H«AsO* - ^^^^jo*

The syrupy solution obtained as above, deposits, after standing for some time at
16^ G. (60^ F.), transparent^ rather long prisms or rhomboidal lamins, containing
8H>0JksK)* -I- HK), or 2H'AsO« + H'O; — they deliquesce rupidly in the air, and
dissolve in water with great reduction of temperature. Both the water of ciystalUsar
tion and the basic water may be expelled by heat.

The crystals heated to 100'' C, first melt, and then yield tlie trihydrate, H*A60*, as
a crystalline predpitate The same compound may be obtained in large transparent
crystals by exposing a concentrated solution of arsenic add to a very low temperature,

* If 0 s 8, the fomute are HO,AtO^, 2H0.A$(^, and iUO^*0\

ARSENATES. 879

K duHdres eaiily in vater, without rednetioii of temperature. The dikydraU, H*As*0',
vhidi may be regarded as a compoand of the mono- and tri-hydrates, is obtained by
heating the erystiJlised add, 2H'AbO^ JPO, for some time to \4.(P^\^(P C; it then sege^
ratea in hard ahining eiyatala, leaving a mother-liquor of spedfle gravity 2*86 at 16^0.
It diasolTeB in water with moderate facility, but the solution is attoided with great
ziae of temperatnre.

The mcmoknirate^ "HAbO^, is fanned by heatiog the before-mentioned CTystals to
800^, and at Jut to 206^ C. ; the mass then suddenly becomes pasty, gives off a large
quantity of aqueous vapour, and is ultimately converted into a white naoreous sub-
atanee eonirintang chiefly of the monohydrate; it dissolves slowly in cold water,
with modente filcility in warn water, producing great evolution of heat (E. Kopp,
Ann. Gh. Phya. [3] zlviii. 196.)

Arweme Qxidis, Arteme Ankydride^ Anhydrous Arsenic Acid^ Pentoside of Arsenic,
AsiK)*, is obtaincid by heating either of the hydrates to dull redness, and remains in
the form of a white mass, which has no action upon litmus ; is nearly insoluble in
water, and in ammonia ; and scarcely absorbs water from moist air, even in the course
of several days, deliquescing only after a long time. At a fiiU red heat, it is resolved
into aisenious oxide and firee oiygen.

The solutions of the three hydrates and of the anhydride exhibit exactly the same
characters ; ihej have a sour metallic taste, and all contain the trihydrate, the other
hydrates beins immediately converted into tiiat compound when dissolved in water: in
this rp^ect, the hydrates of arsenic add differ essentially from those of phosphoric add.

Arsenic oadde is reduced to the metallic state by ehareoal, metals^ cyanide offotas-
shtmj ^^ at a red heat, in the same manner as arsenious oxide. Aqueous arsenic add
dissolves sine and iron, with evolution of pure hydrogen ; but if sulphuric or hydro-
chloric add is present^ the arsenic acid is reduced, metallic arsenic, and solid arsenide
of hydrogen are depodted, and arsenetted hydrogen gas is evolTod (p. 363). An electric
eurreni passed \hrough aqueous arsenic add addulated with sulphuric or hydro-
ehkxrie add eliTniTiat.es arsenetted hydrogen, provided the solution does not contain
ddondes (Bloxam). Sulphurous acid reduces arsenic acid to arsenious add, with
fivmation of solphuric add. Hydrosulphuiric acid slowly predpitates trisulphide
of snenic, the action beine assisted by heat, or b^ the presence of another acid.
Bypomdphite of sodium added to a solution of arsenic add containing hydrochloric
add, bhflwise tiirows down trisulphide of araenio mixed with sulphur :

5Na«K)» + 2H»AsO* - As«S» + S« + 6Na«S0* + 8H«0.

Azaeme add and its salts are very poisonous, but not in so high a degree as
arsenious add and the arsenites (Wohler and Frerichs, Ann. Ch. Pharm. Ixv. 336).
A strong solution of arsenic add placed upon the skin produces blisters like bums.

Arsenic add is now extendvely used in calico printing, in place of tartaric add, for
develoinng white patterns on a coloured ground in the chloride-of-lime vat.

ABsmrAiBS. — Arsenic add is a strong add, expelling all the more volatile adds
from their salts at high temperatures. It is tribadc like ordinaiy phosphoric add,
the general formula of its salts being M'AsO\ in which 1 or 2 at M may be replaced
by hydrogen. The solutions of the tri- and <2t-metallic salts, M'AiO^ and M'HAsO^ ;
(aoDBietimes called basic and neutral) have an alkaline or neutzal reaction ; those of the
«»0Mo-n|etallie (or acid) salts, MEPAbO*, have an add reaction. The di- and mono-
metallic arsenates give off their water when heated, but take it up a^ain on being dis-
solved in water : consequently there are no arsenates corresponding to the pyro-
and meta-phoaphatea.

The arsenatee of the alkaH-metals are soluble in water; of the others, only the
mooometallie salts are soluble in water ; but the di- and tri-metallic salts dissolve
readily in free arsenic add, and in the stronger mineral adds, less easily in acetic
adds : heoee solutions of salts of the earth-metals and heavy metals are predpitated
by arsenate ofpotasdum, but not by free arsenic add.

The Airn^i^nu* arsenates of barium, strontium, and caldum, are insoluble in water,
but soluble in ammoniacal salts ; hence solutions oontaining arsenic add together with
large quantities of ammoniacal salts are not predpitat^ by the salts of barium,
strontium, and caldum. When solutions of metallic salts are predpitated by a dime-
tallic arsenate of an alkali-metal, an insoluble trimetallic arsenate, M'AsO*, is often
fixmed, the liquid at the same time acquiring an add reaction.

A solution of an arsenate in h;^drocluoric add is slowly predpitated by sulphuretted
kfdrogen, the predpitate consisting of trisulphide of arsenic and sulphur in the pro-
portion of the pentasulphide; and if the metallic base of the salt is ukewise thrown
down by sulphuretted hydrogen from an add solution, a predpitate is formed consist-
ing of a metallic sulpharsenate. A solution of an alkaline sulphide^ with subsequent

380 ABSENIC: OXIDES.

addition of hydrochlorie acid, acts in the same maimer as ralplmietted hydrogen.
An aqueous solution of an arsenate boiled with hyposulphite of todium, depodti
trisulphide of arsenic and snlphur on addition of hydrochloric aiodi JPoiatk vitb*
draws from the insoluble arsenates the whole or part of the arsenic add.

Solutions of the tri- and di-metallic arsenates of alkali-metal giTC white pncipitattt
with baryta^ or lime-^ater, also with salts of barium, stronHum, cafenmi, the ettrtk-
meUUs, manganese, einc, and lead, also with stannous and ferrio salts ; jeOovuh-
white with uranic and mercurous salts, yellow with mercurio-^a^ ; rose^obured with
(X>&a/^salt8| ereen with nickel-BsltBi pale greenish blue with euj^ salts; li^t
brown with^o^tntc salts ; brown-red with «i^«er-salt8. These precipitates tie for the
most part soluble in arsenic, sulphuric, hydrochloric^ and nitric acid, and in MM^wiin^
salts : arsenate of silver, however, is not soluble in ammoniacal salts.

MamUsium'tml^A mixed with sujQicient chloride of ammonium to prevent predpita*
tion by ammonia, give with solutions of arsenates, a white crystiJline precipitate
of arsenate of magnesium and ammonium, insoluble in aqueous ammonia and in
chloride of ammonium ; the latter character distinguishes it from the ooirespondiog
salt of arsenious acid (p. 377). — Solutions of arsenates added to excess of wAybdsk
of ammonium containing nitric add, form, when the liquid is heated, a farigkt jeDov
precipitate of arseno-molybdate of ammonium. — ^All arsenates dissolved in mter or
m nitric acid, give with hasio acetate of lead, a white precipitate of 'arsenate of lead,
which when ignited with charcoal, meltp and is reduced, with abundant evolntioii of
metallic arsenic. The last three reactions afford very delicate tests for anenic idd.
The reaction with uranic salts is also very delicate, being perceptible to the trenty-
thousandth degree of dilution.

The arsenates are isomorphous with the corresponding phosphates.

Arsenate of Aluminium, 2A1*0*.ZAbK>\ is obtained by double decompontion
as a white precipitate, easily soluble in free acid, and remaining as a Titreoos m&s
when the solutions are evaporated.

Arsenate of Ammonium, — The triammonic salt, (NH*)'AsO*, is obtained hj
supersaturating a strong solution of anenic acid with ammonia, as a heavy sohble
powder, which, when slightly heated, is quickly converted into the following salt: —
The diammonio Bslt, (NH*)^H.AsO^ is formed in the manner just mentioned, and aleo
by saturating a strong solution of arsenic acid with ammonia till a precipitate begins
to form ; by leaving ttie solution to evaporate, it is obtained in prismatic erTstals of
the trimetric system, which efiBoresce in the air, giving off half their ammonia, bat no
water. When heated, it decomposes, yielding metallic arsenic, ammonia, mter, and
nitrogen gas. Its solution has an alkaline reaction. The manammome or aeid salt^
NH^H'. AjbO'. is obtained by imperfectly saturating arsenic acid with unmonia. It is
deliquescent, vezy soluble in water, and separates from the solution by spontaneoos
evaporation in square-based octahedrons. It is decomposed by heat like tiie preced-
ing. Its solution has a strong acid reaction.

Arsenate of Barium, — The tribaryiio salt, Ba'AsO^ is obtained as a vhite
powder, nearly insoluble in water, by precipitating aqueous arsenic acid with biiyta-
water (Laugier), or better, by graaually dropping trisodie arsenate into chkrids
of barium (Graham). The d&arytio salt, 2Ba^HAsO*, is obtained when a solvtioa
of the disodic salt is added drop by drop to an excess of chloride of barium. lii <m tbe
other hand, the arsenate of soditLm is in excess, the precipitate formed is a niiton
of the di- and tri-barytic salts, while monobarytic arsenate remains in solution. The
di-barytic aalt contains, according to Mitscherlich, | at water (2Ba*HAsO* 4- HH));
according to Berzelius, 2 at. It gives up its water at a red heat. In contact vitli
water, it is resolved into the monobarytic salt, which dissolves, and the fribairtie salt
which remains undissolved (Berzelius). The mofio6ar^fie salt, BaH*AsO\ is ob-
tained by adding baryta-water to aqueous arsenic acid till a precipitate b^;in8 to fbm ;
also by treating the dibarytic salt with water, or better, by dissolving it in aqncMH
arsenic acid, and leaving the solution to crystallise. If a very large excess of arseoie
acid be used, the solution evaporated nearly to diyness, and the mass treated ^th
water, there remains a white powder, consisting of an acid salt eontaisiog
Ba"0.8HK).2As«0* + 2HK), or 2BaH«AsO*.AsH)» + 2H«0. (Setterberg.)

Arsenate of Barium and Ammonium, Ba*(NH*)AsO* + JH*0, is obtained by
mixing the dibaiytic salt with ammonia (Baumann), and Ba(NH*)HO*, by mixing
a solution of nitrate of barium with arsenic acid (Mitscherlich); botii salts ara
formed as bulky precipitates, which become crystalline after a while.

Arsenate of Calcium. — The dicalcic salt occurs native, as Saidingmte^
2Ca«HAsO* + IPO, and Pharmacoltte, 2Ca'HA80« + 6H*0, and may be prepawd
like the corresponding barium-salt. The monocalcic salt is soluble^ the trioakk W

ARSENATES. 381

inaofaiUe in water; the latter is obtained hj preciiatating chloride of c&laun in
cxoesB with triflodic azsenate. (Graham.)

ArwetuOe of Calemm and Ammonium^ Ca.*(SK*)ABO* + 613*0, is prodnoed, accord-
ing to Waeh ^Schw. J. zii. 285), by mixing a hot solution of arsenic add in excees
ef ammonia^ with nitrate of calcium, and crystallises on cooling in tables arranged
like steps; if the solntions are mixed cold, the salt is precipitated as a powder. Any
aneniooa acid that may be present remains dissolved. Another salt CifSB^fELAaO*
is obtained by adding ammonia in excess to a solntion of dicaldc arsenate in nitric
add, as a flooeolent jpredpitate, soon changing to a mass of needle-shaped ciystals. If
onfy enoogh ammmna be added to predpitote a portion of the salt, and the remaining
liquid be left at rest» the same salt is obtained in crystals belonging to the regular
system : it is therofine dimorphous. (Baumann.)

CerouM Arsenate, 2Ce*0 jisK)' (?), is a white powder insoluble in water, but
dissolying in arsenic add as an add salt^ which dries up to a Titreous mass.
(Hisinger and Berzelins.)

Ckromie Arsenate, — Ckramie salts yield with arsenate of potasdum an apple-
green predpitate.

Arsenates of Cobalt, — ^The eobaliie salt is a brown predpitate, obtained by
adding arsenate of potaanum to a solution of oobaltic hydrate in acetic add.

Oo&itotts Arsenate. — ^The trioobaltaus salt occurs in red crystals, as oobalt-bloom,
Go'Aa0^.4HK) (Kersten), a seoondaiy product formed by the weathering of cobaltine
(see Cobuult-bloom) ; and is obtained artificially as a reddish powder by predpi-
tatinff cobalt-salts with trisodic arsenate.

A basic arsenate of cobalt^ known in commerce as Chaux mitaUique, is prepared :
I. By adding carbonate of potasdum to a solution of cobalt-glance in nitnc acid or

S[ua-regia, as long^ as a white predpitate of ferric arsenate continues to form, then
terin^ and treating the filtrate with more carbonate of potasdum to predpitate
oobaltoDS arsenate. — 2. By fusing cobalt-glance with twice its weight of crude potash
and a little quartz-sand, exhausting the ftised mass with water, which takes up sul-
phide of potassium, together with arsenic, iron, and potasdum, and again fusing the
white regains with potash, whereby a blue slag is obtained, which is used for the pre-
paration of smalt, and a pure regains of arsenide of cobalt, which, by careful roastmg,
IS coBTerted into the required baisic arsenate.

The product obtained bv dther of these processes is a reddish powder, which dis-
sdlves in ammonia with bluish-red, or in hydrochloric add with led colour. Caustic
potash extracts the arsenic add and leayes a blue protoxide of cobalt, which, when
Ignited with 1 or 2 pts. of alumina yields a fine blue pigment.

Oentele, by mdting Chaux mitalUque, prepared in the wet way, in a porcelain fkir-
nace, obtuned a mass, the cavities of which contained deep blue prisms, yidding a
zose-coJonred powder, easQy soluble in acids, and consisting of 4Co'O.As'0*.

The dieodaitotts salt is not known. The monoeobaltoua salt is obtained by eyaporat-
ing in yaeno the solution of cobaltous hydrate in excess of arsenic aad.

A r senate of Copper, Cu*AsO\ is obtained as a green powder by predpitating sul-
phate of eefpper with disodic arsenate, the liquid at we same time b^ming add. If
the liquid, together with the predpitate, be mixed with a sufB.dent quantity of
ammonia to di»olye the predpitate, and the solution be then left to evaporate, crystals
are obtained, consisting of Cu(NH^)'AsO* + NH*.H.O, which are permanent in the
air at ordinary temperatures, but are decomposed by exposure to sunshine, or by a
temperature of 300^ C, ammonia and water first passing ofi^ and arsenious oxide sub-
Uming at higher temperatures.

Sereral biuie arsenates of copper occur as natural minerals, viz. 4CuH).As'0',
oeenxnng with 1 at. water as- oUvenite, with 7HK) as euchroite, and with lOHH)
as Uroconite; also 5CttH)jLiH)*, occurring witii 2HH) as erinite, with SHH) as
apkanese, and with lOHH) as leiroeJuroite {jtvpferschatm).

Arsenate of Iridium, — ^Brown predpitate formed on adding arsenate of sodium
to dJoride of iridium, and heating.

Arssnates of Iron,—Aferric arsenate, 2Pe*0«.3H«0.3As*0» + 9Aq, or/c*HAsO* +
SAq^ is obtained by predpitating ferric chloride with disodic arsenate, as a
white powder, which turns red and gives ofi* water when heated. At a red heat it
^ows slightly, and acquires a more yellowish tint. It dissolves in hydrochloric and
in nitric acid, separating as a white powder on evaporation. It is insoluble in acetic
add and in ammoniacal salts. Aqueous ammonia dissolves it immediatdy when recently
predpitated, slowly after drying. The solution when evaporated leaves^ a ruby-red,
transparent, fissured mass, consisting of ammonio-ferric arsenate, soluble in ammonia,
Imt decomposed by pure water, whidi extracts arsenate of ammonium, together with

882 ARSENIC : OXIDES.

the undeeompOMd portion of the salt^ and leares ferric arsenate. The aiwinftniVil
eolation remaine clear when mixed with fenocyanide of potasnnm, hot on additkm of
an acid yields Ptusaian blue. When difenous arsenate is oxidised with nitric add
and ammonia is added in excess, a precipitate is formed consisting of PeH)MiK)*, or
f^ABO\ insoluble in ammonia. Potash in larse excess extracts part of the add,
leaving a compound of 7 pts. arsenic acid (anhydrons) with 79 pts. feme oxide, eorre-
spondmg to the formula 16Fe«0*JLB'0*+ 24HK) (Berzelius). On heatingtibii nit to
zednessi bright iocandescenoe takes phu$e, but no arsenious oxide is giyen oC

Iron-ciruler is a natiye fenie arsenate containing 2Fe^0'.AsK)* -¥ 12H*0; toorodUt
is Fe*0«.As«0* + 4H'0 or /e«AsO* + 2HH) ; cube-ore is a fernMhferrkenmtU^
EeK).Fe^O'.As*0* + 6HH); pUtieiU or brwm iron ore is a fenlb anenato, 2Fe*0*.
AsK>* •«- 12HK), combined, or perhaps only mixed, with ferric sulphate and vater.

h. Ferrous Arsenate is obtained by precipitation as a white powder, which aarames
a dirty green colour when exposed to tho air.

Arsenate of Lead, — ^The triplumbie salt, Pb*AsO\ is prepared by droppinff aaola*
tion of a lead-salt into excess of disodic arsenate, or by digesting the dipuunbic aalt
with ammonia. When heated, it turns yellow and cakes t(^ther, but does not melt
Insoluble in anmionia and ammoniacal salts. A teiraplufnlne salt, 2Fb^AiF0* or
Pb^AsH)', is precipitated on mixing a solution of nitrate of lead with azseoie add, or
with less than the e^uiTslent qaantily of di-anunonic, dipotassic, or disodie aiBenate;
It is a white crystallme powder, insoluble in water and in aoetie add, soluble in nitxie
and in hydrochloric add.

Arsemhohlorids of Lead. — ^In many yarietieB of ptfromorphiUt PbGL3FbT0*, the
phosphorus is more or less replaced by arsenic.

Arsenate of Magnesium. — ^The trimagnesie salt, Hjg'AsO^ is formed hypred-
pitating sulphate of magnesium with disocuc arsenate^ or by boiling the dimagnesic
salt for a long time with a strong solution of arsenate of sodium. — ^The dmagiiakfi^
2Mg'HAsO^ + I3HK> (Graham), is formed as a white insoluble predpitateonnuxiiig
the dilute solutions of 3 pts. sulphate of magnesium, and 6 pts. disodic anenate. In the
recent state, it dissolves easily m nitric add, but it is insoluble in adds after ignitios.
The monomagnesic salt dissolves readily in water, and dries up to a goiftmy mass.

Arsenate of Magnesium and Ammonium^ Hg*(NH*)AsO* + cfrO, u ohtaiaed
as a crystalline precipitate by adding arsenic add strongly- supersaturated with am*
monia to a solution of a magnesium-salt mixed with siu-ammoniac. At lOO^t). it
gives off ^ of its water (44'28 per cent.), together with ammonia and a certain portion
of arsenic. Like the corresponding phosphate, it is almost insoluble in water con-
taining ammonia, or in sal-ammoniac, and is therefore well adapted for the estinatiaB
of arsenic acid, and for separating that add from arsenious ada. (H. Rose, p. 367.)

An arsenate of Magnesium and Calcium^ containing Ca'HAB0*.Mig'HA80*+ (&'AaO^.
Hg*AsO^ + 6H'0, occurs native as picropharmaoolite.

Arsenate of Magnesium and Potassiumf Mg'KAsO^ is produced by fusing aiMoate
of magnesium with excess of carbonate of potassium, and adding 1 at hjdrate
of potassium : it is easily decomposed by water. The corresponding soeUvm'mt is
obtained in like manner.

Arsenate of Manganese^ Mn'HAsO^ is obtained by saturating arsenic add vith
recently predpitated carbonate of manganese.

Arsenate of Manganese and Anvmonium^ Mn'(NH^)ABO* + 6HK). — Beddish-^te
predpitate, gummy at firsts afterwards becoming crystalline : obtained like the eotre-
sponding magnesium-salt.

Arsenates of Mercury. — ^A mercuric arsenate is obtained as a yellow jne^itale
on adding arsenio add to mercuric nitrate, or arsenate of sodium to merconocfakxi^lf'
The same yellow salt is produced, with yolatiJisation of arsenious oxide, when aneoM
oxide is heated with mercury.

Di-mercurous arsenate, 2Hg*0.H*0AjK)» + HH), or Hh^.HJLsO* + |H^*» "
obtained b^ dropping mercurous nitrate into a strong solution of arsenic add, as a
white precipitate, wMch turns red in drying. When, on the other hand, aneiu«
add or arsenate of sodium is added to the mercurous solution, a double salt of anenate
and nitrate of mercurosum is first formed ; but it quickly decomposes, especially if
heated, assuming a yeUow, orange, red, and ultimately purple tint When ^thff of
these predpitates is aissolved in warm nitric add, and the add is gradually neutralised
with ammonia, a black predpitate is formed, which turns red when heated for soum
time.

Dimercuroos arsenate is composed of fine needles, sometimes brown-red, sometiiMi
purple-red. When dried at 100^ C, and then more strongly heated, it first gives v

• Uhg 1 Hg m 200.

ARSENATES. 883

a litHe water, then merenzy, and leaTee yellow mercitric anenate, whicb, at a higher
temperature, la lesolTed into mercury, arsenious oxide, and free oxygen. With oold
esncentrated hydrochloric acid, it yields a solution of arsenic acid, and a residue of
calomel, which is reeolTed by boiling into mercury and soluble mercuric chloride. It
is eonyerted into mercuric arsenate by boilmg with nitric acid, but dissolves unchanged
in that acid when cold, the solution being precipitated by ammonia. It diaeolTcs
sligfatiy in aqueous nitrate of ammonium, and separates on eyaporation with fine red
ooJoar and cEystaUine stmeture. It is quite insoluble in water, acetic acid, and am-
monia.. (Simon, Pogg. Ann. xli. 424.)

Moncfmervuroua arsenate^ HhgAsO*, or Hg^O.AsK)', is produced b^ boiling mercuric
oxide, or the di-mercurous salt, to dryness with aqueous arsenic acid, triturating the
dry mass when cold with water, washing the powder, and drying it oyer the water-
bath, whereby the whole of the water is expeUed. It is white and amorphous, giyes
off mercury at a red heat, and leayes mercuric arsenate, which then undergoes farther
decomposition. By careful addition of potash, it is eonyerted into the £mercurous
salt. With hydrochloric acid and with boiling nitric acid, it behayes like the dimercurous
salt. In eM. nitric acid it dissolves less abundantly than the latter, and on heating
with gradnal addition of ammonia, it yields a precipitate of the dimercurous salt. It
is insoluble in water, acetic acid, and alcohol. (Simon.) #

A doable salt, consisting oi arsenate and nitrate of Tnercurosumy Hhg*As'0^2HhgN0*
is obtained, when water is carefully poured upon an equal volume of a strong solu-
tion of mercorous arsenate in moderately strong nitric acid, and an eciual volume of
aqueous ^Tnmonii*. then added, without allowing the liquids to mix. The double salt
is then gradually dqiosited in white nodules and needles. If the mercuzous nitrate be
mixed with a very small quantity of nitric acid, the compound is obtained in the form
of powder. (Simon.)

Arsenate of Molyhdenum.---Molyhdou8 Arsenate \s a gi^ precipitate, produced
by mixing molybdous chloride with arsenate of sodium. The precipitate redissolves
at first, bat afterwards becomes permanent.

Arseno-molyddie Acid. —Arsenic and molybdic acids digested together yield a colour-
less acid solution, and a lemon-yellow basic salt, insoluble in water. The solution
cTaporated to a syrup, yields colourless crystals, which when treated with alcohol, first
yield white flocks, and then dissolve.

Arsen(Hmolybdate of Amnwnium. — On adding arsenic acid to a solution of molyb-
date of ammonium and heating to 100° C, a yeUow precipitate is formed, similar to
that produced by phosphoric acid. It contains 7 per cent, arsenic, and appears to be
analogous to phospho-molybdate of ammonium. (See Phosphokic Acm.)

Arsenate of Nickel^ Ni'AsO*, occurs as nickel-bloom, and is obtained by double
decomposition as an apple-green czystaUine powder, insoluble in water, soluble in
arsenic acid and in other stronff acids, also in ammonia; from the latter solution
potash throws down hydrate of uckel free from arsenic

Arsenate of Palladium. — Light yellow precipitate obtained by heating to-
gether the solations of neutral nitrate of paUadium and arsenate of sodium.

Arsenate of Platinum. — Light brown powder soluble in nitric acid, obtained by
precipitating platinic nitrate with arsenate of sodium.

Arsenate of Potassium. — The tripoiaesic salt, K"AsO\ is obtained, by mixing
aqueous arsenic acid or the neutral salt with potash-ley, and strong concentration, in
small needles, which deliquesce quickly in the air. The dipotassic salt, K'HAsO\ is a
deliquescent non-ciystaUine mass, produced by saturating arsenic acid with potash, or
by fusing anenious oxide with hyorate of potassium.

The monopotassie salt, KR^AsO* (Maoquer's areenikalisehes Mittelsals), is prepared :
1. By deflagrating arsenious oxide with an equal weight of nitre, dissolving the faaed
mass in water, and leaving the solution to crystallise. — 2. By mixing aqueous
carbonate of potassium with such a quantity of arsenic acid, that the solution reddens
litmus-paper but the redness disappears as the paper dries, and then evaporating. —
3. A mixture of potash-ley and arsenic acid neutral to vegetable colours, deposits the
monopotassie salt when partially evaporated, the alkaline dipotassic salt remaining in
solution (Mitscherlich). Monopotassie arsenate is isomorphous with the corre-
monding phosphates of potassium and ammonium, and with monammonic arsenate.
The crystals have a specific gravity of 2*638 ; they are permanent in the air, and give
off but little water, even at 288^ C., but at a red heat they melt, give off water, and are
eonv«ted into a thin liouid, which on cooling solidifies into a ^ite mass, cracked in
all directions. Thqr dissolve in 5*3 pts. of water at 6^ C, forming a solution of
speeific gravity, 1*1134; they are much more soluble in hot water, but insoluble in
aicohoL The aqueous solution reddens litmus, but the redness disappears on drying.

884 ARSENIC : OXIDES.

It do€fl no€ precipitate the salts of bariam, caleium, magnerinxii, or the oQisr eiitli-
metals.

Arsenate of Bfiodiunu — YeUowish-white precipitate formed by heating aneiiat«
of sodium with chloride of rhodium and sodium.

Arsenate of Silver. — The tn^raentic salt, Ag'A80\ is theonly one that can be
obtained by precipitating nitrate of suTer with soluble arsenates ; it is a duk brown
precipitate wnich melts to a brown-red glass when heated, is conyerted into chloride of
silver byhydrochloric acid, dissolyes in aceticacid and aqueous ammonia, and vhen bested,
in sulpnate, nitrate and succinate of ammonium. It dissolves also in aaneons aoenie
acid, and the solution, if left to evaporate, deposits the monargentic salt, AgH'AiO*.
Both this salt and the mother-liquor from which it has separated, are deoompoied bj
water, yielding the brown triargentic salt^

The tziaigentic salt treated with sulphuric aoid yields by evaporation a doable silt,
Ag*As'0'«Ag%0\ which is decomposed by water and by dilute snlphozie add.
(Setterberg.)

Arsenate of Sodium, — The trisodie salt, Na'AsCH 4- 12HK) isprepezedbyftulof
1 at. of the disodio salt with carbonate of sodium, or by mixing the aqueous solntioi
of arsenic acid witl^ excess of carbonate of sodium, and evi^K>rating to a small bulk.
The salt then crystallises almost completely, the excess of soda remaining dunlTed.
The dystals are right rhombic prisms permanent in the air; thej have an aDuliM
taste, melt at 86^ C, and dissolve in 3^ pts. of water, the solufaon as well u tin
ignited salt absorbing moisture froin the air. The disodio salt, Na'HAsO* + 12EP0,
separates from a solution of arsenic acid slightly supersaturated with caibonate of
sodium, and left to evaporate below 18^ C, in la^ ^orescent crystals isomoipbooi
with ordinary phosphate of sodiunL By leaving a more concentrated BoHitio& to
crystallise at 20^ C. or above, crystals are obtained belonging to tiie monodiniesyitaB,
containing 14 at. water, and not efflorescent Both kin£ of crystals give off the
whole of their crystaUisation-water, at 200^ C, melt easily at a mgher tempentore,
and give off tiheir basic water, leaving the anhydrous salt, 2Na*0.AsK)*, or M*A!?0';
this anhydrous salt, however, recovers its basic water when redissolved. Afioordia^
to Setterbeig, a salt with 26 at., water of crystallisation separates from a BoluUaa
cooled to 0^ C.

The monosodie salt, KaH'AsO^ is formed when arsenic acid is added to carboute
sodium till the solution no longer precipitates chloride of barium ; it cmtalliflei out
after a while in the cold. It is more soluble than the disodic salt^ and fonns laige
crystalB isomorphous with the corresponding phosphate.

Arsenate of Sodium and Ammonium, Na(liH^)HAsO^ + 4HK), is obtained by mix-
ing the solutions of the di-ammonic and disodic salts, in crystsls exactly reaembliog
those of the corresponding phosphate (microcosmio salt). When heated to redsen,
they leave monosodie arsenate. (Mitscherlich.)

Arsenate of Sodium and Potassium, KNaHAsO* + IGH'O. (Mitscherlich).—
Obtained by neutralising the monosodie salt with carbonate of potassium. The 07^
contain, according to Mitscherlich's analvsis, 43'88 per cent, water, the preoedinp for-
mula requiring 44*16 per cent. ; but as th^ appear to be ismorphous with the duodi«
salt containing 14 at, L. Gmelin (Handbook iv. 299) considers it probaUe that
they also contain the same quantity of water.

Arseno-fluoride of Sodium, Na«AsO*.NaF + 12H*0.— Prepared by gradnally in-
troducing a mixture of 1 pt aisenious oxide, 4 pts. carbonate of s<winm, 3 pts.
nitrate of sodimn, and 1 pt. fluor-spar, into a red-hot crucible, and ultimately heating
to complete fosion. On boiling the fiuad mass with water and filtering, the dosUe
salt crystallises out in regular octahedrons, exactly like common alum. They have 1
specific gravity of 2*849 at 21^' 0., dissolve in 9*6 pts of water, at 26^ C^ aDdin2ptk
at 75^ 0. (Briegleb, Ann. Gh. Pharm. xcvii. 96.)

Arsenosulphate of Sodium. — ^A solution of 3 at Ka*HAsO\ mixed with 1 at sulphvie
acid, yields crystals containing Na»AsHD»».2Na«S0\ or 4Na«0.3A««0» + 2(Ka«0W;
their solution slightly reddens litmus, but still turns turmeric brown (Hitscheriich).
By dissolving sulphate of sodium and disodic arsenate together in equivalent propoitioDSi
or by heating anhydrous disodic arsenate in a current of sulphurous anhydride (half ^
arsenic acid being then reduced to arsenious acid, which volatilises), and subeeqneot
recrystallisation, a salt is obtained, composed of Na^O^Na^AsK)*, which does not
alter by exposure to the air, and frises more easily than either of its component salts.
(Setterberg.)

Arsenate ofStrontium^ Sr'HAsO*.— Resembles the barium-salt By pncipitat-
ing its solution in nitric acid with excess of ammonia, a double salt is produced oontain-
log 8r«(NH*)As0« -i- JH*0.

ARSENIC: OXYBROMIDE. 385

- ArMenate of 7Aof tntim, is obtained by doable decomposition; as a white floccnlent
precipitate^ insoluble in water and in the aqueous acid.

Art en at 9 of Titanium, — Arsenic acid added to solution of titanic oxide, throws
down white flocks, which di^ up to vitreous masses, and are soluble in free titanic
add, as well as in arsenic acid.

Arsenates of Tin.— ^The stannic salt, 2SnO»wAjs»0» + lOH^O, or (Sn)«As»OM0H«O,
is precipitated as a gelatinous mass when a mixed solution of stannate and excess of
arsenate of sodium is treated with excess of nitric acid. It is transparent when diy,
and giyes off all its water at 120° C. (Haeff ely, Phil. Mag. [4] x. 290.)

Stannous Arsenate is a white precipi%te obtained by adding arsenic acid to stannous
chloride or acetate. Tin heated with aqueous arsenic acid eliminates hydrogen and
forms a gelatinous mass.

A r senates of Uranium, — Uranio arsenate^ or Arsenate of Uranylf (ITK))*HA80* +
4HK>, is formed by precipitating uranic acetate with arsenic acid, or uranic nitrate
with arsenate of sodium. It is a yellow precipitate which gives off its water at
120»C.

A MMHo-uranic nitrate^ (TJ'0)NaAsO + f HK), is obtained by mixing a solution of
uranic nitrate with trisodic arsenate ; ana by boiling uranic arsenate with solution
of basic acetate of copper (obtained by digesting verdigris with water), a green cuj^o-
iifw»r ar<«nai^ is formed^containingj(n'0).CuAsO* + 4Aq. (Werther.)

Uran4fus Arsenate, U*JBLAsO* + fH^O, is a peen precipitate obtained bv treating
uranous chloride with disodic arsenate. It dissolves in hydrochloric add, and the
solution mixed with excess of ammonia yields a veiy bulky predpitate of tri-uranous
arsenate, XPAsO*. (Bammelsberg, Pogg. Ann. lix. 96.)

Arsenates of Vanadium, — A solution of vanadic hydrate in excess of arsenic
add yields by evaporation, a crust of blue crystalline granules, containing 1 at.
vBname oxide (VO) to 1 at. anhydrous arsenic acid. It dissolves very slowly in
water, but easily in hydrochloric acid. A more basic salt is obtained as a Kjrxvpy
mass, mixed with crystals of the preceding salt, by evaporating a solution of arsenic
add saturated with vanadic oxide.

If the solution of the crystalline compound in nitric add be evaporatod till nitrous
add begins to escape, a j&low powder ib deposited, which is a compound of vanadic
and azsenic anhydrides, 2VK)*.3As*0«.

Arsenate of Yttrium, — The di-yttric salt obtained by precipitation is a whit«
heavy powder, which dissolves in nitnc add, and separates therefirom in crystalline
grains. The nitric acid solution supersaturated with ammonia yields the tri-yttric salt.
Yttria dissohres in excess of arsenic add, but the solution when heated deposits tlie
di-yt^c salt

Arsenate of Zinc, — Acetate of zinc treated with arsenic acid or arsenate of
Bodxoni, yields a white precipitate, which dissolves in excess of arsenic acid, and se-
parates on evi^ration in cubical crystals of an acid salt. Zinc dissolves in aqueous
anenic add, with evolution of arsenetted hydrogen, and deposition of metallic arsenic
mixed with brown solid arsenide of hydrogen. When zinc and arsenic oxide are fused
together, a large quantity of arsenic is reauced, with sb'ght detonation.

TVizincie Arsenate^ Zn'AsO^ + 4H'0, occurs as Kbttioite in the Daniel cobalt mine
near Schnecberg in Saxony, forming monoclinic oystafs, or crusts with crystollino
stnustnre. Speofic gravity 3'1. Hardness 2*5~3. It is of light carmine or peach-
blossom colour, translucent, and gives a reddish-white streak. The zinc is partly
replaced by cobalt and nickel. Analysis 37-2 per cent. As*0*, 30-6 Zn*0, 6*9 Co^'O,
2-00 Ni«0, with trace of lime, and 23-4 water. (-Kottig, J, pr. Chem. xlvii. 183;
Nanmann, ibid, 2d6.)

Sulphate of zinc added to a solution of arsenate of sodium containing ammonia pro-
duces a predpitate of trizindc arsenate, which soon changes to a crystalline compound
containing, according to Bette, Zn»ABO«.NH*.f H'O (?)

Arsenate of Zirconium, — ^White predpitate insoluble in water.

fkWIKWnCp paCYBXOBDCDS OF. Bromarsenious Acid, AsBrO. — Arsenious
oxide dissolves easily and abundantly in fused arsenious bromide, forming a somewhat
Tisdd daii:-colonred liquid, which does not solidify so quickly as the pure bromide.
If this liquid be distilled till it becomes rather thick and then allowed to cool to about
150*^ (C. or F. ?) it separates into two layers, the lower of which is a soft dark-coloured
masBi consisting of the oxybromide AsBrO, while the upper, which is very viscid, is a
compound of the oxybromide with arsenious oxide, probably 6A8BrO.A8'0' ; both these
bodies are decomposed by heat, giving off bromide of arsenic (W. Wallace, Phil. Mag.
[41 rrii. 122). An oxybromide of arsenic is likewise formed by the action of water on

Vol, JU 0 0

386 ARSENIC: SULPHIDES.

the bromide (SernllaB). When hiomide of anenic is boiled with a quantity of
containing hjdrobromio acid not sufficient to dissolre it, the undiaBolved partioQ is
converted into oxybromide. A cold solution of bromide of arsenic in water containing
hydrobromic acid, yields, by eraporation oyer sulphuric acid, thin white pearly dyBtak,
consisting of hydrated oxybromide, 2AsBr0.3H'0. A solution of bromide of araemc
in water, prepared at the boiling heat^ deposits on cooling crystals of arsenious oxide ;
but if the water contains a large quantity of hydrobromic acid, the solution deposits on
cooling, white flocks of a compound, which after drying between fllter>paper, consists
of 2Ai%r0.3As*0* + 12H'0. — When bromide of ammonium is added to a cold con-
centrated solution of bromide of arsenic, six-sided tables are slowly deposited, oozunating
mainly of anhydrous bromide of arsenic. (Wallace, loc. cit.)

AmsaMXOfOaKTCB&OBZDB or. ChhrarseniousJcid. AsG10,arAsGl*JU>O'.

— ^Pulverised arsenious oxide added in successive portions to boiling chloride of azsenie
continues to dissolve till the liquid contains 2 at. chloride to 1 at. oxide. The same
solution is obtained by passing dry hydrochloric acid gas into a vessel containing dry
arsenious oxide till the latter is dissolved : great heat is evolved during the renctioxL
On distilling the solution obtained by either process, till it begins to traai, and leaving
the residue to cool, oxychloride of anenic separates as a viscid, translneent, brownish
mass, which fumes slightly in the air, and absorbs oxygen firom it, £roths whoi stron^y
heated, giving off chloride of arsenic, and at the subliming temperature of aiaenions
oxide, leaves a hard vitreous residue, consisting of AsClO.AsK)*.

Oxychloride of arsenic is likewise produced when chloride of arBemc is treated with
a quantity of water not sufficient to dissolve it completely. A solution of chloride of
arsenic in the smallest possible quantity of water (8H*0 to lAsCl") deporita, after
some days, small, white, needle-shaped crystals, grouped in stars or like prehnite, and
consisting of AsClO.H^ ; the mother-liquor yields an additional quantity when mixed
with chloride of sodium.

Oxychloride of arsenic unites with metallic chlorides. By mixing aqueous chloride
of arsenic with a quantity of hydrochloric add sufficient to prevent the separation of
oxychloride, and then adding a lump of sal-ammoniac, crystals of that siJt aepante
out at first, and after a few days, fibrous needles of the compound AsC10.2NHHil,
apparently containing \ at. H'O, which ia given off when the crystals are left over sol*
phuric ack (Wallace Phil. Mag. [4] xvi. 368.)

ABBSWZC, OXTIOBXBB OV. As^PO" « 2AsI0.3A8K>*.— A hot aqueous solu-
tion of arsenious iodide deposits, when concentrated by boiling, fine red needles of the
anhydrous iodide ; but if left to cool slowly, it deposits thin pearly lamins, which after
drying between bibulous paper, are composed of 2AsI0.3As'O' + 6HK), and give off all
their water over sulphuric acid. They are decomposed by water, and when heated
yield a sublimate chiefly consisting of iodide of arsenic, while arsenious oxide remains
behind (Wallace, Plul. Mag. [4 J xvii. 122). The formation of this componnd had
previously been observed by Phsson and by Serullas and Hottot, who regarded it as
a compoimd of arsenious oxide with arsenious iodide. (Gm. iv. 282.)

AXSBWZCf OZTSV&PBXBa OV* See SuLPKOSABSBirATB of PoTAsatrx

(p. 395).

JkMMBMTLCf 8IT&PBZBB8 OF. The sulphides of arsenic are more numefons
than the oxides. There are three well defined sulphides, AsS, As^', and As^* [or
AsS', AsS^y and AsS^^ if 8 — 16], all of which act as sulphur-acids. The first two
occur as natural minerals, realgar and c^rpiment, and may also be obtained in the Iree
state by artificial processes ; the third is known only in combinatioik Besides these
compounds, there is a. suhstdpkide, As'53(?)i which remains as a brown powder when
the disulphide AsS is digested with caustic alkalis ; and, according to Berzelius, a per-
sulphide^ AsS*, obtained in yellow crystalline scales, by mixing a solution of dipotasanc
or disodic sulpharsenate with alcohol, and evaporating to about two-thirds ; but the
product thus obtained is most probably a sulpharsenate with excess of sulphur. When
arsenious oxide is fused with sulphur, sulphurous anhydride is evolved, and a sulphide
of arsenic containing excess of sulphur remains. On distilling this residue, sulphur
passes over, accompanied by a continually increasing quantity of avsenie. Vuni of
the ordinary sulphur of commerce is a compound of this nature.

Disulphide of Absbwic. AbS. Realgar^ Red Orpimeni, or Ruby Stiipkur;
rothes Rauschgelbf Arsenic sulphur I rouge^ Risigallo; Sandaraca of Pliny and
Vitruvius ; o-oySopoin} of Theophrastus and Dioscorides. In combination : Htfosuuv-
AS8BNI0U8 Actd. — This compound occurs native as realgar, ciystallised in oblique
rhombic prisms of the monoclinic system, having an orange-yellow or aurora-red
colour, resinous lustre, and more or less tmnslucent: streak vaiying from orange-
red to aurora-red ; fracture con'choidal, uneven ; sectile. Specific gravity « 3*4 to S'fi.

ARSENIC: SULPHIDES 387

Hardness » 1*5 to 2. It is found accompanying ores of silver and lead, at Andreas-
hoTg in the Han, Kapnik and Kagyag in Transylvania, Felsobanya in Hongary,
JcMchimsthal in Bohnnia, and Schneeberg in Saxony. At T^owa in Hungary, it
o<?curs in beds of day ; at St. Gothard imbedded in dolomite ; near Julamerk in
Koordistan ; also in the Vesuvian lavas, in minute crystals. Strabo speaks of a mine
Ktitandaraca at Pompeiopolis, in Paphlagonia. (Dana.)

Dimlphide of arsenic may be prepared by melting metallic arsenic with sulphur or
orpimenty or sulphur with arsenious oxide, in the required propoitions. As thus
obtained, it is transparent and of a ruby-colour, easily ftisible, and crystalline after
solidification from fiision. An impure product is prepared on the large scale by heat-
ing in a subliming apparatus a mixture of arsenical pyrites and iron-pyrites, and
melting the product with arsenic or snlphnr, according as a darker or lighter colour is
denrcd. This commercial product is amorphous, u^iallv brown-red, opaque, and of
variable composition, geneitilly containing arsenious oxide. It is used as a pigment,
though not so much now as formerly.

Disulphide of arsenic bums in the air with a blue flame, forming sulphurous and
arsenious oxides. When deflagrated with nitre, it produces a bright white light.
Indian white firt is a mixture of 24 pts. nitre, 7 pts. siuphur, and 2 pts. realgar. The
disulphide heated with nitric acid, yields arsenic acid and free sulpur. With strong
tulpiuric aeid^ it forms sulphurous and arsenious acids. When it is digestkl in fine
powder with potoBk-ley, part dissolves and there remains a brown powder consisting
of As^. (?)

HTPOsxTLPHASSENirBS. — These are sulphur^salts formed by the mixing of disulphide
of arsenic with basic sulphides. They are for the most part sparingly soluble in
water. The little that is known of them is due to the researches of Berzelius.

The ammotUumr^t is deposited in small dark brown granules on the sides of a
dosrd vessel in which neutral sulpharsenite of ammonium is kept for a long time. It
absorbs ammonia-gas, but gives it off again on exposure to the air.

liypogtUpkaraenite of Potassium, — The colourless liquid obtained by boiling trisnl-
phide of arsenic with moderate concentrated carbonate of potassium, deposits in the
course of 12 hours, brown-red flocks of the salt K'S.AsS, or K'AsS'. K this compound
be washed with a small quantity of cold water till it swells up to a jelly, and then
treated with more water, the greater part dissolves, forming a red solution of the salt,
3K^.2A&S, and leaving an insoluble oark-brown powder consisting of K%.4AsS, which
melts easily when heated, and solidifies on cooling to a transparent dark red mass.
The basic salt 3K^2Ai)S, remains perfectly soluble in water, even after complete
drying.

The sodium hyposulpkarsenites resemble those of potassium.

Other hyposulpnarsenites are obtained by precipitation. The barium and calcium
saltjs aro rea-hrown ; tiie magnesiumrsalt is brown ; the mangancse-salt dark red.

Trisulphidb of AnsiKic, or Absbnious Sulphidb. In combination:
SuiPHABsnnous Acid. As'S', or AsS^. Orpiment, Ydlow Sulphide of Arsenic, GiU)es
Hansckgdby Bisigallum, Aurtpigrnentum (Vitruvius); Arsenicum (Pliny); *KpiriviKoif
(Dioscorides) ; ^K^^vmow (Theophrastus). — This sulphide occurs native in^ rhombic
prisms belonging to the trimetric system, easily splitting parallel to ooPoo into tliin
flexible laminae. They are translucent, of lemon-yellow colour, inclining to orange-yellow,
with pearly lustre on the cleavage-faces, resinous elsewhere ; powder lemon-yellow ;
speciflc gravity 3-469 (Karsten), 3*48 (Hobs, Haidinger), 34 (Breithaupt).

Triaulphide of arsenic is obtained in the pure state by passing hydrosulphuric acid
gas into a solution of arsenious acid or an arsenite acidulated with one of the stronger
aei<Ls. As thus prepared, it hss a fine lemon-yellow colour, becoming darker by heat,
and produces an orange-yellow powder: it melts easily and volatiBses at a higher
temperature.

Aji impmv trisnlphide is prepared on the large scale by subliming 7 parts of pulve-
rised arsenious oxide with 1 pt. of sulphur. It always contains more or less oxide,
inasmuch as to convert that compound completely into trisulphide requires 7*3 pts. of
aolphnr to 10 pts. of the oxide : hence this preparation is much more poisonous than
the pure artificial sulphide or the native sulphide. It was formerly much used as a
pigment, under the name of Kin^s yellow, but is now almost entirelv superseded by
chrame-yellow. The arsenious oxide may be extracted from it by boiling with water,
or with dilute aqueous acids, or cream of tartar.

Aisenioos sulphide is also used in calico printing, the pattern being printed with a
prepaimtion containing arsenious acid, and then passed through water containing
oydrosofphuric add. A solution of orpiment in potash-ley is used in dyeing as a de-
oxidising agent, especially for reducing indigo. A paste composed of slaked lime,
orpiment, and water, is employed by some nations as a depilatory for removing the

cc 2

388 ARSENIC: SULPHIDES.

beard ; but it ifl a dangerous preparation, and, according to Bottger may be n*
placed for this pnipose by solphydrate of caldmn.

Decom^oosUion$, — 1. Araenious sulphide, like all the other sulphides of anenie, is
converted by oxidirina agenU into oxides of sulphur and arsenic. When it is fiued
-with add sulphate ofpotasfsum^ sulphurous oxide (SO') is nven of^ and anenite ol
potassium remains mixed with neutzal sulphate. — 2. Exposed to the action of cAMu
gas^ it becomes heated, and deliquesces to a brown liquid consisting of a Bolphochloride
of arsenic, As*Cl*S' (H. Bose). — 3. The yapour of arsenious solphide passed otbt red-
hot iron, nlver, and other metals, is decomposed, yielding a metallic solphide and
free arsenic, which, if the other metal is in excess, unites with it

4. When the yapour is passed over red-hot lime, arsenic is sqiarated, and azaenate
of calcium is produced, together with sulphide of odcium.

6. Arsenious sulphide heated with earoonate ofpotauium or sodium in adan tabe,
yields a mirror of arsenic, together with sulpharsenate and arsenate of toe aUati*
metaL If the mixture is heated in an atmosphere of hydrogen^ or with addition of cior*
ooo/, the arsenical mirror is increased by the arsenic reduced from the araeoate; the
sulpharsenate remains undecompoeed. (H. Bose, Pogg. Ann. xc. 666.)

6. When arsenious sulphide is heated in a test-tube with a mixtme of dkdm
carbonate and cyanide of potassium^ the whole of the arsenic is reduced, aoootdiDg to
Fresenius ; only part of it, according to H. Bose, because the sulphnr-salt of aneDk
formed at the same time resists the action of the cyanide of potaaniun. Heooe
arsenious sulphide fused with cyanide of potassium and excess (u snlphor does not
yield any arsenical miiror. The formation of the mirror may also be prerented bj
the presence of other easily reducible metals, which conyert the aiseme into an
arsenide, and do not give it up.

7. When arsenious sulphide is boiled with the solution of an alkaline earhonaU^ and
the concentrated solution is filtered, a clear liquid is obtained, which deponta a brown
powder, consisting of hyposulpharsenite of the alkali-metal, while a sulphanenate re-
mains in solution. A similar decomposition takes place when a soluble neatral anlph-
arsenite is treated with water.

8. Arsenious sulphide is readily dissolved by cold caustic potash, soda, or ammteia,
undergoing exactly the same decomposition as antimonious sulphide under sisular
circumstances (p. 322), the oxygen of the alkali converting the arsenic into flnenioos
acid, while the alkali-metal unites with the sulphur, and the basic solphide thm
formed combines with the rest of the arsenious sulphide :

4Ab«S« + 6K*0 « 8(K«aAs^ + 2K*OJLbK)«

On adding an acid to this solution, no sulphuretted hydrogen is evolved, batthe vbola
of the sulphur and arsenic are separated as arsenious sulphide :

8(K»S.As«S«) + 2KK).As«0« + lOHCl - lOKCl + SBK> + Os^S*

SuLPHABSSNTTES. — Arseuious sulphide unites with basic metallic sulphides in three
different proportions, forming, with potassium, for example, the compounds 3K^SAb9
or K«A8S«, 2K«S Afl«S» or K*As«S», and K«S.As«S« or KAsS« [or SK8,2At8', 2K8Jt^,
and KS.AsS*, — Of these, the dibasic or teirametallic salts are the most oommon, and
are regarded as neutral or normal sulpharsenites.

The soluble sulpharsenites are prepared: 1. By igniting sulpharsenates out of eon-
tact with the air, 2 at-, sulphur then escaping. — 2. by dissolving arsenioos snlphiden
an alkaline sulphide or sulphydrate; in the latter case, sulphuretted hydro^n is eroheiL
— 3. By dissolving arsenious sulphide in a cold solution of caustic alkak—i. By dis-
solving arsenious oxide in an alkaline sulphydrate, in which case half of the alkah u
converted into arsenite ; e.g.:

As«0» + 2KHS « KAsS* + B:AsO« + H*0.

The only sulpharsenites that are soluble in water are those of the alkali-metal^
alkaline earth-metals, and magnesium, and even these are decomposed by water, ob1m>
the water is in considerable quantity. Hence the solutions cannot be evaporated to
dryness without decomposition. The solutions are colourless or yellowish, tasting
hepatic at first, and afterwards disgustincly bitter. — 6. The sulpharsenites of the
earth-metals and heavy metals are obtained bv precipitating a solution of the eoJW'
spending compound of an alkali-metal, obtained by either of the methods 2, 8, 4, vita
a salt of the earth-metal or heavy metaL (Berzelius.) ^ ^

The sulpharsenites are either yellow or red. Most of them, when ignited cot of
contact of air, give off all their sulphur-acid ; others ^ve up such a ouantit^ that the
residue contains 8 at sulphur^base to 1 at. sulphur^aeid ; but the sulphaisenitesofthe
alkali-metals, even those which contain equal numbers of atoms of base and '^'^J^
off nothing when ignited. The alkali-metal compounds obtained by the firat methodr

SULPHARSENATES. 889

•

wben treated vith a small qnantity of water, and the dilute solutions obtained by
method 2, S, or 4, when they evaporate in the air, are resolved into 1»rown hyposulph-
azaenito which is precipitated, and sulpharsenate which remains in solution ; but the
deoompofiition is not complete till the solution is concentrated to the crystallising'
point of the latter salt. Jf the decomposed mass be digested in a large quantity of
water and boiled, the whole is reconverted into sulpharsenite and redissolved« The
»>lutionB of the barium, strontium, calcium, and magnesium salts, containing 1 at. base
to 1 at. add, deposit, on boiling, a portion of the arsenious sulphide ; the ammonium,
potassium, sodium, and lithium compounds remain undecomposed. On adding alcohol
to the aqiieous solution of a compound of 1 at. of arsenious sulphide with 2 at. of the
sulphide of an alkaH-metal, a compound containing 3 at. of sulphur-base is precipi-
tated, while a compound containing 1 at. of sulphur-base remains in solution :

2(2K«SjLbS«) =. 8K«8JlsS« + K*S.AflS«.

But the precipitated tribasic salt soon turns black, being resolved into hypoeulph-
aisenite and sulpharsenate. The potassium and sodium compounds exhibit this
WaM't'Aning on the addition of alcohol, even when the solution contains nothing but
tribasie salt (3K'S«As^) ; but with the ammonium, barium, strontium, and calcium
saUa, it does not take place unless the solution contains dibasic salt (2Ba'S.As'S*). —
Aqueoos sohitions of snlpharsenites exposed to the air are decomposed by oxidation
(more slowly in proportion to the excess of sulphur-base), depositing orpiment and a
bfown oomponnd of disulphide of arsenic with the sulphur-base. Hydrated oxide of
copper, added to a solution containing a compound of sulpharsenious acid with the sul-
phide of an alkali-metal, decomposes that compound, yielding twelve-basic sidph-
azsenite of copper, which remains undissolved, and a hyacinth-red solution, containing
an alkaline arsenite and tribasic sulpharsenite of copper, and deposits the latter on the
addition of hydrochloric acid. Perhaps in this manner :

9(K?aAs«S^) + 27Cu«0 - 2(12Cu«S.As«S») + 3Cu*SjLb«S» + 3(3KK).2AsW).

If the hydrated oxide of copper is in excess, the arsenious add contained in the solu-
tion is converted into arsenic add, and the protoxide of copper reduced to sub-oxide.
— Oxide of silver in excess decomposes the solution, forming sulphide of silver and
alkaline axsenite:

KAsS« 4- 2Ag«0 » 2Ag*S + EAsO*.

Sulpharsenite of Ammonium^ 2(NH*)^.As'S^. — The solution of arsenious
solphida in sulphide of ammonium or caustic ammonia yields, when mixed with
alcohol, a predpitate of this composition, which, however, soon turns brown. If
pievionsly mixed with sulphydrate of ammonium, it deposits white feathery crystals of
the basic salt (3NH^)^SLAs^'. Finely divided arsenious sulphide absorbs 6J per
cent, of ammonia-gas, but gives it up again when exposed to the air.

' Suipkareenite of Barium, — ^The solution of arsenious sulphide in sulphydrate of
barium dries up to a red-brown gummy mass of the neutral salt, 2Ba'S.As%*, perfectly
sohible in wator. Alcohol predpitates i^m the solution crystalline flakes of uie basic
salt, 3Ba%As^, which is likewise obtained by treating arsenious sulphide with excess
of sulphide of barium.

Sulpharsenite of Bismuth^ 2Bi^S'.A8^, is a red-brown predpitate, which
tnrns black in drying. By fusion, a grey metallic-shining mass is obtained, con-
sisting of the basic sut

Sulpharsenite of Cadmium, — Cadmium-salts mixed with a saturated solution
cf arsenious sulphide in sulphide of ammonium, yield a yellow predpitate, 2Cd^. As^*.
-which becomes orange-yellow when dry, and semifluid when heated, giving off part of
the aisenioas sulphide, and leaving a fused grey compound containing a larger pro-
portion of cadmic sulphide.

Sulpharsenite of Calcium, — When orpiment is digested with milk of lime, and
the solution is filtered from the arsenite of calcium, which forms at the same time, a
eoloorless filtrate is obtained, which, by spontaneous evaporation, yields feathery
crystals of the basic salt 3Ca'SAs'S', surrounded by a brown syrup of the neutral salt
SCia^BLAs'S^. This syrap digested with an additional quantity of arsenious sulphide
torus yellow and deposits a brown powder consistin j^ of h^powlpkarsenite of caldum,
CSa^.2Asfi. The solution of the sulpharsenite containing excess of sulphide of caldum
jields^ with alcohol, a white predpitate of the basic salt, containing 3Ca%.As%* + 16Aq.

Sulpharsenite of Cerium^ 200*8^8*8*. — ^Yellow predpitate, which acquires a
deeper colour when dry, melts, and evolves part of the arsenious sulphide when heated,
and when roasted gives up all its arsenic, and is completely converted into sulphate.

Sulpharsenite of Chromium^ 2Cr*S*.3As*S*. — Greyish-yellow precipitate^

390 ARSENIC: SULPHIDES.

greenish-yellow after drying. When heated, it melts and gives off part of tlie
arsenious sulphide, and is converted into chromic oxide by roasting.

Sulpharseniie of Cobalt, 2Co*S.As%', is a daric brown precipitate, wbidi
becomes black in drying, dissolyes in excess of the precipitant, and when ignited
in close vessels, leaves a residne having the composition of cobalt-glanoe.

Sulphar aenite of Copper. — A twelve-basic salt, 12Ca^.As*S', remains undis-
solved as a brown mass, when cupric hydrate is added to solution of monopotassic
sulpharsenate, till the colour of the liquid is no longer altered. The tribasic <a/<,
SCu'S.As'S', is precipitated in li^ht brown flakes on adding hydrochloric add to the
hyacinth-red solution obtained in the manner just mentioned. The neutral salt^
2Cu'S.As'S, is obtained by adding neutral sulpharsenite of sodium to a cupric salt, aa
a black-brown precipitate, which acquires a metal-grey as^t by trituration. When
distilled, it first gives off sulphur, then arsenious sulphide, and leaves a tomefied
metal-grey substance, probably consisting of cuprous hyposulpharsenite.

Sulpharsenite of Glucinum, 2G%.As^S', is a yellow precipitate, formed, without
evolution of sulphuretted hydrogen, on adding a neutral glucinum-salt to a solution
of sulphide of sodium saturated with arsenious sulphide. Adds separate but litde
sulphuretted hydrogen from it, ammonia partly dissolves it, and leaves pure gladna.

Sulpharsenite of Gold^ 2Au*S'.3As^. — Yellow predpitate, beeoming^ daricer
as it settles down, black when dry, and yielding by trituration a jellow-brown powder.
At a dull red heat, it melts, gives off part of the arsenious sulphide, and solidifies to a
transparent yellow-red mass, yielding by dry trituration a yellow-brown mass, whi(^,
however, by continued trituration under water, assumes a metallic lustre, as if
from reduced gold. To expel the whole of the anenious sulphide requires a lull
white heat.

Sulphareenitea of Iron. — The ferric salt^ 2Fe*S*.3As*S*, is an olive-green
precipitate, soluble in excess of the precipitating alkaline sulphanenite, acquiring a
green colour when diy, and a fine yellow-green by trituration. It melts easily when
heated, and decomposes at a red heat, leaving pure sulphide of iron. Theferrous salt,
2Fe''S.As'S', is a brown-black precipitate, ^so soluble in excess of the precipitant ;
grey-brown when dry, dark greenish after trituration. It is decomposed by heat,
leaving pure sulphide of iron. The dried precipitate always contains ferric oxide
mixed with the preceding salt

Sulpharsenite of Lead, 2Pb*S.As*S*. — Red-brown predpitate, blade when dry;
melts to a brittle metallic-looking mass, a shining grey crystalline fracture, and yield*
ing a grey powder.

Sulpharsenite of Lithium resembles the potassium- and sodium-salts.

Sulpharsenite of Magnesium. — The aqueous solution evi^porated, or eoaled
to —5° C, becomes light brown, and deposits a brown powder consisting of hypMnl-
pharaenite of magnesium ; then dries to a visdd mass, which ultimately aouaifies^
and is almost wholly soluble in water.

Sulpharsenite of Manganese, — Light red predpitate, becoming orange-yellow
when cby. Heated in dose vessels, it gives off a considerable portion of the ammicnis
sulphide, and leaves a yellow-green compound, fnxm. which hydrochloric add extracts
the manganese, with evolution of sulphuitetted hydrogen, leaving a residue of anenioua
sulphide.

Sulpharsenites of Mercury. — The neutral msrcurio salt, 2Hg^Jl^S*, is an
orange-red flocculent predpitate, which becomes white in presence of excess of mercuric
chloride, but retains its colour if the precipitant is in excess. It is dark brown when
dry, and gives a yellow powder. When heated, it yields a grey metallic-shining sub*
limate of Hg'S. Ab%', wiiich is translucent in thin films, and vidds a ydlow powder
when findy ground. The m^curous salt, 2Hg*S.As*S', is a black predpitate, which
decrepitates with explosion when distilled, giving off mercury andyidding a sublimate
of mercurous hyposulpharaenite in black opaque metallic crusts, which yidd a red
powder.

Sulpharsenite of Molybdenum, — The solution of molybdic add in hydiocfalorie
add forms with sulphanenite of sodium, a dark brown powder, which becomes black in
drying, and decomposes at a red heat, giving off arsenious sulphide and sulphur, and
leaving disulphide of molybdenum, MoS.

Sulpharsenite of Nickel, 2Ni'S.AsS', is a blade predpitate, which, when distalkd.
easily gives off all its arsenious sulphide, and leaves yellow sintered sulphide of nickeL

Sulpharsenite of Potassium. — The neutral salt, 2K%.As*S', is obtained hf
igniting the corresponding sulpharsenate (2K*S.Ab*S') till the exoesa of sulphur is

SULPHARSENATES. 391

driren off It is a dark yellow mass, which becomes yellow on cooling. Treated with
water, it yielcb a solution of basic Bulpharsenat« (SK'SjU^^) and a residue of
hypoaolpharsenite. When arsenions snlphide is dissolyed at mean temperature in
aqueous snlphydrate of potassium, till all the sulphuretted hydrogen is eliminated,
the solution contains an aeid tulpharsenite, K%.2iLB^. This solution is decomposed
by evaporation, depositing brown hypoenlpharBenite of potassium, K'S. AsS. On mixing
the aomtion with alcohol, a white precipitate of 3£'^.As*S' is formed at first; but
it soon becomes brown and muyv, and deposits the hyposulpharsenite. When car-
bonate of potassium is fdsed with arsenious sulphide till the excess of the latter is
expelled, there remains a mass, consisting of K^^As'S*. This salt is decomposed by
water, the acid salt^ K'S.2As'S', dissolying, and a compound, still richer in arsenious
sulphide^ remaining undissolved.

8ulpkar»enit$ of Silver, 2Ag'S.As%*, is a light brown precipitate, transparent
at firsts becoming black during collection ; when heated in the dry state, it melts and
gJTes off part of the arsenious sulphide. The black fused mass yields a brown powder.
vHien acid sulpharsenite of sodium is precipitated by a saturated solution of chloride
of silTer in ammonia, a dark yellow precipitate is formed, containing 6Ag*S. As%'.

SulpkarteniU of Sodium. — Strictly analo^us to the potassium-salt

Sulpharsenites of Tin, — The stannous salty 2SnS.As'S*, is a dark red-brown
preeipttate, infusible, but giving off part of its sulphur at high temperatures. The
stanmie salt, SnS'jis^, is a gummy yellow precipitate, which becomes orange-yellow
whendiy.

Uranic Sulpharsenite, 2TJ^S'.As%', is a dingy yellow precipitate, which melts
and gives off part of its sulphur when heated, and, after exposure to a white heat,
leaves a grey porous mass, still containing arsenious sulphide.

Sulpharsenite of Zinc, 2Zn*S.As*S^. — Lemon-yellow precipitate, orange-yellow
when icy ; gives off arsenious sulphide when heated, leaving a more basic compound,
and at a hi^er temperature, pure sulphide of zinc

Sulpharsenite of Zirconium, 2Zr*S'.As'S'. — Qrange-yeUow precipitate, quite
insoluble in excess of the alkaline sulpharsenite.

PsiTTASULPHiDS ov Absbnio, or Absbnio Sulphidb. In combination:
Sui.PBaB8BiiT0 Acid. As*S*, or AsS^, — ^A substance containing arsenic and sulphur
in this proportion is precipitated when a soluble sulpharsenate is decomposed by hy-
drochloric acid ; but it appears to be rather a mixture of the trisulphide with free
■ulphur. When sulphuretted hydrogen is passed into an aqueous solution of arsenic
acid, sulphur is first separated, and remains for a long time suspended in the liquid.
The precipitate contains a very small quantity of trisulphide of arsenic, which may be
extracted oy dilute ammonia, pure sulpnur then remaining. The filtered liquid is then
lonnd to contain arsenic acid, together with a small quantity of arsenious acid ; and, if
snlphnretted hydrogen be then rapidly passed through it for a short time, a precipitate
of trisulphide of arsenic is obtained. If this precipitate be separated by filtration, and
the passage of the sulphuretted hydrogen continued, the liquid again becomes turbid
from separation of sulphur, and, by repeating these operations, the whole of the
unenic may be precipitated as trisulphide. ^L Boss, Pogg. Ann. cvii 186; H.
Xndwig, Arch. Pharm. [2] xcvii. 23.)

A snlphide of arsenic corresponding to anhydrous arsenic acid, AsK)*, does not
therefore appear to exist in the free state. Nevertheless, the precipitate thrown down
by arids from solutions of sulpharsenates has the composition of the pentasulphide,
and ms such dissolves completely in alkaline sulphides and in strong ammonia ; dilute
ammonia, however, dissolves out the trisulphide and leaves the sulphur.

SuLFHABsaKATBs. — Thcso salts may be regarded as compounds of pentasuljphide of
arsenic with basic metallic sulphides. Our knowledge respecting them is chiefly due
to the researches of Betzelius. They are for the most part mono-, di, or tribasie, a few
instances only occnnrinff of sulpharsenates with larger proportion either of sulphur-
base or sulphur-acid. Their general formuls are :

Honobasic or HonometaUic . ]iR9.As*S* or MAsS* « '^(s*

Dibaoc or Tetzametallio . 2M^As'S* or H'As>S'

Tribosieor.Trimetallic • 8]raAii*S»orM*AsS« - ^A&

iaS)

MS"

• Or MS,AtS*, 9MS.AsS^, and ZMS.AsS^,

OOi

892 ARSENIC: SULPHmES.

The tetrametallic salts are generally regarded as neutral ; the monometaUic u add;
the trimetallic as basic.

The solpharsenates are prepared : 1. By passing sulphuretted hydrogen through the
solution of an arsenate in water or in hydrochloric acid, thus :

K'AflO* + 4H«S - K»AflS< + 4H»0.

— 2. By fiising orpiment with excess of sulphur and a caustic alkali or alkaline earbonste.
— 8. By digesting the trisnlphide in an aqueous solution of a disnlphide orpolTBulphidfl
of alkaU-metal. — 4. By dissolving the pentasulphide (As^ + 2S) in a caustic alkali,
or in an alkaline carbonate at the boiling heat. In this case an arsenate is formed at
the same time. — 6. ThQse sulpharsenates which are insoluble in water maj be obtained
by precipitation from the solution of an alkaline sulpharsenate.

The ary sulpharsenates of the alkali-metals are lemon-yellow; the othen red or
brown. They are permanent in the air. Those which are soluble taste hepatic at
first, afterwards intensely bitter. The tribasic salts have a tendency to eiyatalliM;
the dibasic and monobasic salts are amorphous.

The trimetallic sulpharsenates of potassium, sodium, lithium, and barium maj, if air
be excluded, be heated almost to whiteness without decomposition ; on ooolii^, thej
solidify to a yellow mass perfectly soluble in water. The tetrametallic and monometaUic
sulpharsenates of these metals give off sulphur when heated, and are conyeited into
Bulpharsenites. The silver- and mercury-salts (the latter of which sublimes) remam
undecomposed at a red heat. The other tetrametallic and monometallic snlpbanenates
are decomposed by ignition, first yielding sulphur and a red salt of snlphaisenioiu add ;
and in many cases, the sulpharsenite is resolved bv continued ignition into trisnlphide
of arsenic, which sublimes, and the sulphur-base, which remains behind. The calcinm-
and magnesium-salts first evolve sulphur, and then the greater part of the trisulphide,
and leave a white imfused compound of magnesium- or calcium-sulphide, with a Teiy
small quantity of trisulphide ; most of the heavy-metal-compounds evolve solphnr at
first, and then all the sulphide of arsenic, so that nothing but the salphnr-baae i«*
mains behind. The sulpharsenates, when heated in the air, give off orpiment and
arsenious oxide, and leave a sulphate when the base contains an alkali-metal, and pore
oxide if it contains a heavy metal. The aqueous solution of the sulpharsenate of an
alkali-metal is decomposed by exposure to the air — the liquid becoming tnrbid, and
depositing sulphur, pentasulpmde of arsenic (As'S* + S') and a brown salt of hypo-
sulpharsenious acid, while alkaline arsenite and hyposulphite are formed, and the latter;
by further oxidation, is converted into sulphate ; the cooler and more conoentnted
the solution, the more slowly does the decomposition proceed. Acids, even carbonic
acid, decompose the alkaline sulpharsenates, separating hydr<%sulphuric acid gas of a

Siculiar odour, and precipitating a mixture of arsenious sulphide and snlphnr.
ydrated cupric oxide, introdnc^ into the solution of an alkaline sulpharsenate,
decomposes a portion of that compound, forming alkaline arsenate and sulphide of
copper, a small portion of which dissolves in the liquid. A similar reaction is
produced by other heavy metallic oxides which do not retain their oxygen with yeiy
great force. (B e r z e 1 i us.)

Many sulpharsenates are soluble in water, namely, those of the alkali-metals,
magnesium, yttrium, and glucinum. The solutions are either colourless or paleyeUor.
From the solutions of the dibasic salts alcohol precipitates a tribasic salt, and leates
monobasic salt in solution. When this solution is placed in a shallow dish, and
evaporated at a gentle heat, there remains a lemon-yellow residue^ from which vater
extracts a dibasic salt. (B e rz e 1 i u s.)

Sulpharsenate of Ammonium, 2(NH*)«S.As*S* « (NH*yAs^\— The aolntioa
of pentasulphide of arsenic in sulphide of ammonium, vields by evaporation, a irisdd,
reddish-fellow mass, which decomposes partially in drying, and still more when heated,
first givmg off a liquid containing disnlphide of ammonium, and then yielding a snb-
limate of arsenious sulphide: (NH*)*As«S^ « 4NH*S + As*S".— The solution beconw
brownish-yellow when boiled, and on cooling deposits a yellow powder composed cf
(NH*)2S.12As*S^ The aqueous solution of the dibasic salt is precipitated by alcohoi
the monammonio or acid salt, NH^AsS', then remaining in solution. If the solntionbe
previously mixed with snlphide of ammonium and heated, alcohol. throws down the
tri-ammonic or basic salt (NH^)'AsS^ in prismatic crystals.

Sulpharsenate of Antimony is a burnt-yellow, easily Aisible precipitate.

Sulpharsenate of Barium. — ^The tribartfOc-salt, Ba'AsS*, is obtained by deeom-
posing the tetrabaiytic or neutral salt: 1, by a red heat ; 2, by mixing its aqueomi aola-
tion with sulphide of barium, the mixture evapqrated in vacuo over sulphuric Add at the
freezing point, yielding the basic salt in loose, transparent, non-crystalline sodes; S, by

ARSENIC: SULPHARSENATES. 393

^irecipitation mth alcohol : it then falLs down as a cnrdy precipitate, very soluble in
water, probably a hydrate :— The dibasic salt, Ba*As*S' » 2Ba*S.Afl«S*, is produced by
satnratuig a solution of neutral arsenate of barium with hydrosulphuric acid. The
solation <uie8 up to a fissured lemon-yellow maasy which, if exposed to the air after all
its water has been drawn ofi^ absorbs water again, swelling up and falling to pieces
at the same time. It dissolves in water in all jpiroportions. With sulphate of potas-
sinm, it yields a precipitate of sulphate of banum, and a solution of neutral sulph-
arsenate of potassium. — The numobarytie or aeid salt, BaAsS^, remains in solution
when the neutral salt is precipitated by aleohoL It is decomposed by evaporation,
yielding a yeUow deposit of the salt, 'Ba?8,BAB^, while the neutral salt remains in
edution.

8uiphar$enate of Bismuth, — Both the basic and the neutral salts are dark-
brown precipltstes, soluble in excess of the alkaline sulpharsenate.

Sulpha r senate of Cadmium is a light yellow powder.

Sulpharsenate of Calcium, — ^The basic salty Ca'AsS^ is obtained by mixing the
solution of the neutr^ salt with sulphide of calcium, and either evaporating or precipi-
tating with alcohol ; it is not ciystallisable, and when precipitated by alcohol, forms
either a powder or a syrup, according to the quantity of water that it contains. It
dissolves easily in water, but is insoluble in alcohol. The neutral salt, Cu^AsS' ->
2^^JUi^, is precisely analogous to the barium-salt. Its solution when evaporated,
coagulates to a syrup, which, if then left to evaporate further, dries up to a yeUow
opaque mass, becoming anhydrous at 60^ C. : when exposed to the air, it absorbs
water, swells up, and detaches itself from the sides of the vessel. There appears to be
no aad sulphanenate of calciunr.

Sulphar senates of Cerium, — ^The eerie salt, 2Ce*S*.As*S*, is a yellowish white
precipitate^ not quite insoluble in water, and consequently not appearing in very
dilute solutions. The eerous salts, Ce'S.As-S^ and 3Ce^.A8'S^ are obtained by
double decomposition as precipitates of a fine yellow colour, which become sothe-
what darker when dry.

Sulpharsenate of Cobalt, Co^As^' *- 20o*S.A8*S', is a brown precipitate which
becomes black when collected and dried, and dissolves with dark colour in excess of
sulphanenate of sodium.

Sulpharsenate of Copper, Cu*As*S* =s 2Cu*S.Afl*S*, is obtained as a dark brown
precipitate^ by treating solutions of copper-salts with neutral sulpharsenate of sodium,
or by pasong sulphuretted hydrogen through an acid solution containing arsenic acid
and cupric oxide: if the arsenic add is m excess, the brown sulphmvsalt is first
precipitated, and then yellow sulphide of arsenic. From a precipitate of tlus kind,
solphLde of ammonium dissolves not onl^ the sulphide of arsenic, but likewise by its
intervention, a large portion of the sulphide of copper. Very dilute ammonia likewise
extracts the sulplude of arsenic : stronger ammonia acquires a brown tint by taking
up some of the sulphide of copper. (Gm. v. 475.)

Sulpharsenate of Glucinum, — Fentasulphide of arsenic digested with hydrate
of glndnum and water, is dissolved to a small amount and repredpitated by adds,
Glncinum-salts are not precipitated by sulpharsenate of sodium.

Sulpharsenate of Gold,— The tribasio salt, (i!u)AsS* - (Au)'S«.As*S*, is formed
by predpitating a gold-solution with tribasic arsenate of sodium. It is a dark brown
precipitate^ soluble in pure water. Petrous sulphate decolorises the solution, and

MMg

throws a yellow-brown substance not yet examined. The dibasic salty 2(AuyS'.8As*S',
obtained by predpitation with neutral sulpharsenate of sodium, dissolves in pure
water, with brown red colour.

Sulpharsenates of /ro«.— The ferric salt, 2Fe*S«.3As«S» =- or /«*As«S^ is a
greyish-^feen predpitate, which dissolves with very dark colour in excess of the pre-
dpitan^ is not altered by drying, but melts easily when heated, giving off sulphur,
and beuig converted into ferric sulpharsenite. — The ferrous sZt, 2Fe'S.As^* «
Fe^As^, is a dark brown predpitate^ which dissolves in excess of the alkaline
snlpharsenate. It decomposes in diying, assuming a rusty colour, and then consists
of a mixture of the preceoing salt with ferric oxide.

Sulpharsenate of Lead.— The salts Pb"AsS\ and Fb^As^^ are obtained by
predpitation. The former Ib black-brown, the latter of a fine red colour; both turn
black in diying.

Sulpharsenate of Lithium, — The basic salty Li'AsS*, is precipitated by alcohol
from tne solution of &e neutral salt in shining, colourless crystalline scales, soluble in
hot water, and separating therefrom on cooling in six-sided prisms, and by spontaneous

894 AESENIC: SULPHABSENATES.

evaporation m four-sided tables with rhombic base. The netUnd salt^ li^ii^, k t
non-CETBtalline lemon-yellow mass, which absorbs moistuo firom the air, tndispeiieetly
soluble in water. The acid salt^ liAsS*, is known only in alcohohe iolation, bdiig
decomposed by evaporation. The hj^peracid aait, with 12 at As9, is pnpaied like
the ooiresponoing potaasinm-salt.

SulphartBtiate of Magnesiufm — ^The tribane salt^ Mg*AsO* or SXg^Sjbj9, fa
obtuned by adding snlphydrate of magnesinm to a solution of the neubnd aah as long
as sulphuretted hydrogen continues to escape, and afterwards evaporating the xdntioii,
or if it be not too dilute, cooling it quickly down. It forms colooriesB ndiatiog
crystals, which become moist on exposure to the air. Aloohol deoompoMi theo,
extracting the neutral salt and leaving a compound of 1 at As^ with man than
3 at. Mg^S, which is nearly insoluble in water. The same compound remains as a
white unfused mass, when the neutral salt is heated to redness in a retort Potash
added to the aqueous solution of the tribasic salt precipitates magnesia, and forms a
solution of tribasic sulpharsenate of potassium. — ^The neutrtU ndtf 2Mg%JLB%*, is a
non-crystalline, lemon-yellow mass, which does not abeorb water from the air, dis*
solves in water to any amount, and is precipitated from the solution by alcohol

Sulpharsenate of Magnesium and Ammonium^ (NH^^Mg'AsS^ (?) — ^Precipitated on
adding alcohol to an aqueous solution of the mixed sulpharsenates of magneaiun and
ammonium, in delicate white needles, which, when exposed to the air, giTe off sul-
phuretted hydrogen and turn yellow. It dissolves easily in water.

Sulpharsenate of Manganese, — The neutral salt, 2Hn%.As'S^ is obtuned hj
digesting recently precipitated sulphide of manganese with water, trisnlphide of
arsenic and sulphur, partly dissolving in the water and partly remaining at the bottom
in the form of a lemon-yellow powder, which however dissolves in a Isurger quantity
of water. The solution when evaporated, yields sulphur, and afterwards d^Kwts a
lemon-yellow mass, no longer completely soluble in water. The neutral salt is lik^
wi^ obtained, but mixed with arsenate of manganese, when carbonate of manganese
is boiled with water and trisulphide of axsenic and sulphur. Hanganons salts an
not precipitated by sulpharsenate of sodium. A sexbasie saltf 6Mn^. As'S*, is produced
by oigesting the yellow powder of the neutral salt in strong ammonia. It is a brick-
red powder, somewhat soluble in water, and, when ignited at one point, contmnes to
bum.

Sulpharsenates of Mercury, — The mercurie salt, 2Hg*S.As*S', is precipitated
from mercuric chloride both by basic and by neutral sulpharsenate of sodium, as a
dark yellow substance, which retains its colour alter drying. It sublimes undeoom-
posed, and yields a powder of the colour of cinnabar. The mcreurous salt^ 2Hg*S.As9,
or Hhg^As^^ is precipitated black from solutions free from mercuric oxide; if
the latter is present, the precipitate is brownish-yellow, and becomes darker in
drying. When distilled, it decrepitates violently and gives off mereuy, and at a
higher t<emperature yieldis a sublimate of the mercuric salt just described.

Mofybdie Acid is is not precipitated by sulpharsenate of sodium.

Sulpharsenate of Nickel. — Nickel-salts, if not too dilute, immediately yield a
black precipitate, with neutral or basic sulpharsenate of sodium. Yeiy dilate solntioDS
first assume a yedlow-brown colour, then yield a precipitate.

Sulpharsenate of Platinum, — The neutral and bamc aodium-salts do not
precipitate platinum-solutions, but merely colour them dark-brown. Ferroos sulphite
added to the brown liquid, throws down a blade-brown substance, whfle the solatioo
becomes colourless.

Sulpharsenate of Potassium.— The tribasie salt, 3K^.As^, or K*AsS«, 'n
deposited as an oily concentrated solution, on mixing the aqueous solution of the
neutral salt with alcohol When dried at a gentle heat, it leaves a fibrous dehqneseent
mass.

The neutral or dibasie salt, 2K*S.As»S*, or K*Aa«S\ is produced by saturating an
aqueous solution of dipotassic arsenate with hydrosulphunc add and evaporating in
vacuo. The residue is a viscid, yellowish, somewhat crystalline mass, which does net
dry up completely, but on exposure to the air first liquefies and then solidifies in a
crysteUline mass of rhombic tablets.

The monobasic or acid salt, K»S.As^*, or EAsS', remains dissolved when the aqoeoos
solution of the neutral salt is precipitated with alcohol The solution is deeompoaed
by evaporation, and deposits crystals of persulphide of anenio (see p. 886X —
2 Aqueous sulphide of potassium dissolves at ordinary temperatures, more than * at
but less than 1 at of pentasulphide of arsenic. The solution, when evaporated in
the air, first becomes covered with a film of sulphur, then deposits a red crusty and by
this loss of sulphide of arsenic, is converted into the dibasic salt, which dries up first to
a stiff syrup and then to a lemon-yellow mass.

ARSENIC: SULPHARSENATES: 395

' A kyper-add salt, K^.12A8^, is precipitated when the solution of the neatial salt
18 decomposed by carbonic acid ; similarly on passing hydrosulphnric acid gas through
monopotassic anenate. — It is a yellow powder, containing 2*9 sulphide of potassium
and 97*1 pentasulphide of arsenic (Berzelius.)

StdpkaxarMnats of P&tasnum, (KK).2H<0)As^S>0' » (K*H«)As%K)*. — Produeed
when snlphiiretted hydrogen is rapidly passed through a cold saturated solution of dipo-
tasaic arsenate (p. 383). The liquid flnt turns yellow, then deposits a small quantity of
trimlphide of arsenic mixed with sulphur, and ultimately a colourless crystalline salt.
When a certain quantity of this salt has been formed, caustic potash is to be added to
the liquid, and tiie stream of sulphuretted hydrogen continued: by this means, an
additional quantity is obtained. The greater part of the sulphide of arsenic must
then be rinsed away with the mother-liquor, and the salt washed with Terr small
quantities of water, pressed, and dried in yacno. It crystallises in small white
dongated prisms, sometimes 1 or 2 centimetres long, slightly soluble in water. The
dry salt ia permanent in the air, and gives up all its' water at 170^ C, without melting.
It fuses OTer the spirit-lamp, giving ofE, first arsenic sulphide and then metallic arsenic.
The aqueous solution decomposes rapidly at a boiling heat, giving off hydrosulphurio
add and depositing sulphur. If hydrochloric add be then added, a precipitate of sul-
phide of arsenic is obtained. From the salt itself, hydrodiloric add precipitates
nothing but sulphur, and the precipitation is complete; the filtrate then contains
arsenious add. Lead-salts added to the solution give a white precipitate, which soon
turns blade. The add of this salt, H'As^H)^ (arsenic acid, having part of its oxygen
replaced by sulphur), cannot be obtained in the free state. If the lead-salt^
immediately after its formation, be collected on a filter and mixed with a quantity
of dilute sulphuric add less than suffident to decompose it completely, a strongly add
liquid is obtained, which gives no precipitate with barium-salts ; but it quickly decom-
poses and deposits sulphide of arsenic. (Bouquet and Cloes, Ann. Ch. Phys. [3]
xiii 44.)

Sulphar senate of Silver. — Both iheneutral and basic isiWs are predpitated from
silver-solutions, with brown colour, turning black in drying ; the predpitates are very
slow in settling down. When they are heated in the air, the sulphide of arsenic bums
away, and sulphide of silver remains ; but if heated to redness in dose vessels, they
fuse wHhout giving off sulphur or sulphide of arsenic, and on cooling soUcUfy in the
form of a grey, somewh&t ductile cake, exhibiting metallic lustre.

Sulphar senate of Sodium, a. Tribasic salt. 3Na'SAsS*+15HK)«2Na»AsS* +
15HK). — Obtained : 1. By precipitating a solution of the dibasic salt with alcohol—
2. By leaving a mixture of the dibasic salt b and sulphydrate of sodium to evaporate.
• — 3. By digesting the alcoholic solution of pentasulphide of sodium with orpiment>
pouring the liquid ofi^ washing the residue with alcohol, then dissolving out the tri-
basic salt with water, and leaving the solution to crystallise. — i. By dissolving penta-
sulphide of arsenic in aqueous soda-solution, and leaving the liquid to crystallise.
The oTstals obtained by either of these methods are washed on a filter with alconol, then
pressed and dried (Berzelius). — 6. By boiling 1 pt. of sulphur, 1} pt. of orpiment,
and 8 pts. of aystallised carbonate of soda with water, and purifying the crystals ob-
tained from the filtrate by rectystalliBation (Rammelsberg, Pogg .Ann. liv. 238).
By method (1) the salt is obtained in snow-white crystals; by (4) in ill-defined rhom-
boidal tables. It crystallises by slow cooling from a hot aqueous solution, in irregular
six-sided prisms, with two of their lateral edges more acute than the rest; W spon-
taneous evaporation or very slow cooling, in transparent rhombic prisms with (uhedral
cmmmits resting on the acnte lateral e^es ; and by still slower cooling, till the tem-
perature hSis bdow 0^ C, in white, opaque, rhombic octahedrons. The opaque
crystals are milk-white ; the transparent crystals are yellowish, and have somewhat
of a diamond lustre. (Berzelius.)

The salt when dry is permanent in the air ; even in vacuo over oil of vitriol, it
does not give up its water tiU gently heated ; it then becomes milk-white ; when more
strongly heated, it ^ves off a small quantity of hvdrosulphuric acid, and turns yellow.
Heated in a retort, in fuses it its water of crystallisation, forming a very pale yellow
liquid, then gives off water, and is converted into a white salt, which, when more
strongly heated, decrepitates slightly, evolves the remaining water and a small quan-
tity of hydKMidphuric add, and fuses to a dark red liquid ; on cooling, this bquid
•(Edifies and forms the yellow anhydrous compound, Na'AsS* (Berzelius). It is
decomposed completely by boiling with sulphate of copper, yielding a predpitate of
fiolphide of copper, wMle soda, sulphuric acid, and arsemc acid remain in solution :

Na'AsS* + 4Cu«Sb* +".4H«0 - 4Cu«S + Na"AsO* + 4H»S0*.

A similar decomposition takes place with acetate of lead ; but the predpitated sul-
phide of lead [if the acetate is in excess], is mixed with arsenate of lead, because that

396 ARSENIC-RADICLES (ORGANIC).

salt ifl insoluble in acetic acid (Rammelsberg). The salt dissolTes easily and
abundantly in water. (B er z el i us.)

b. JHbatie or Neutral 9alt 2Na^.AB^sNa^A8%^ — The aqoeona aolntion of di-
Bodic arsenate saturated with hydrosulphnric acid gas, and then left to eyaporate spon-
taneously, yields a Tisdd liqni<i, and afterwards, if gently heated, a dry lemon-ydlow
mass. This substance melts at a moderate heat, forming a very pale yellow liquid
(losing water at the same time if wanned in an open tcss^), and on cooling solidifies
in a yellow mass, which softens when exposed to the air. (JBerzelins.)

c. MonoboMO ialt. Na*S.As^ » NaA^. — When the tribasic salt is prepared with
tUcohol according to method (1), the supernatant alcoholic solution contains the
mono-basic salt. On distilling off the alcohol, the liquid often deposits persolphide
of arsenic in b^utiful oystals.

d. HypeT-acid saltj Na^.l2As'S'. — Yellow powder, obtained like the potassimn
compound. (Berzelius.)

StUpharaenate of Sodium and Ammonium^ (NH^)'AsS*.Ka'AsS\ is obtained by
mixing the solutions of the two basic salts with alcohol, and cooling slowly, where-
upon it collects on the sides of the vessel in small four-sided tables ; or more easQy by
dissolving sal-ammoniac in an exactly proportional quantity of the basic eodnun-salt
and leaving the solution to evaporate ; it then separates in yellowish six-sided prisms,
permanent in the air, and mucn more soluble in water thim the sodium-salt. Wheo
distilled, it gives off sulphide of ammonium with a little water, leaving snlpharsenite
of sodium.

The neutral sulpharsenates of sodium and ammonium dry up to a yellow mass when
mixed.

Sulpharsenate of Sodium and Potassium. — ^Yeiy regular four-sided tables^ baring
a faint yellowish colour.

Sulpharsenate of Strontium. — The neutral salt is obtained in the same manner
as the barium-compound. On mixing the solution with alcohol, the basic salt is pred-

Eitated, sometimes as a syrup, sometimes as a white powder, according as it is more or
tea purified ftom the neutral salt.

Sulpharsenates of Tin. — Both the neutral and basic sodium-salts ibrm witb
stannous chloride, a oark chestnut-brown precipitate ; with stannio chloridi^ pale
yellow gummy precipitates, becoming orange-yellow when dry.

Uranic Sulpharsenate.— The neutralBsXt, 2U*S".As»8* or(TJ*S)*As'8',isadinjgy
yellow precipitate ; the basic salt has a somewhat darker colour. Both dinolve with
dork brown colour in excess of the precipitant.

Vanadie salts give no precipitate with sulphaxsenate of sodium ; but the Uoe
solution is deooloris^

Sulpharsenate of Yttrium. — Resembles the glncinum-salt.

Sulpharsenate of Zinc. — The neutral salt is a light yellow precipitate^ the bask
salt till lighter; both are orange-yellow when diy.

Sulpharsenate of Ztr^onttfm. -—Solutions of ziroonium-salts aie precipitBted.
though not immediately, both by basic and by neutral sulpharsenate of sodium ; tiie
precipitate is lemon-yellow while moist, orange-yellow after dxyiiig. Adds do not
extract zirconia from. it.

[O AXi COBA&T9 00»BK« Zaow, &C. See the several metalai
COAIi VTXXTBS. See Ibon, Absbmides of.

COA& vnOVBOBm. Arsenite of barium isnited with gom-tiaga-
canth, is said by Osann to yield a greyish-yellow pyrophoric mixture.

CCMRABZO&BS (O&HJLWZC). Arsenic unites with the alcohol-
radicles, forming compounds analogous to those of antimony, and containing 1 at.
arsenic, combinMl with 1, 2, 8, or 4 at of the organic radide. The following is a list
of the compounds of this class at present known. Those to which no fonnqhe are
assigned, have been but imperfectly studied.

Arsenides of AllyL

Arsenides of AmyL

Arsenides of Ethyl:

Arsenethyl As(C^»)

Arsendiethyl, or Ethyl-cacodyl . . . Asf <?H*)*

Arsentriethyl, or Triethylarsine • . . As(0*H')*

Arsenethylium, or Tetrethylarsonium . . As(CII*/

ARSENIDES OF ETHYL.

39T

As(C2H»)(C«H*)

A8«(C«H*)"(C*H»j

AflNH«(C«H*)''(C^H*)»

A8(C»H»)«Au

A8(C?H*)»Pt

Ab(CH»)

Afl(CH»)«

Afl(CH«)«

As(CH»)«

A8(CH»)»(C«H»)

Afl(CH»)>(C«H»)«

A8(CH«)(C»H»)»

Afl(CH«)XC»H»»)«

Anen-bromeihyl-triethjliiim
ArsenTinyl-triethylium
Ethjlene-hexethyl-dianonium
Ethjlene-triethylarsammoiiinm
Anivnenethjlimn .
Platanenethylium « •

Arsenides of Hethjl;

Axsemnethyl • • • . .

Azsendimeth jl, or Oacodjl
Anentrimethyl, or Trimethylarsine .
Anenmethjlinxii, or Tetramethylarsonium .
Arsentrimetfajl-ethTUum
Arsendimethyl-dietiiylinin
AneDmethyl-triinethyUTuii
Azsendunethyl-diamylinm . .

Arsenide of Tetryl (or Butyl).
Arsenide of Trityl (or Propyl).

These oomponndB are produced, like the antimonideB of the aloohol-radides, by dia-
tining tiie iodides of these radicles with arsenide of potassium or sodium. Arsen-
dimethyl, or eaoodyl, is likewise formed by distilling a mixture of arsenious oxide and
an alkaline acetate, and was obtained in this manner by Cadet, so long ago as 1760.
The di-trityl and di-tetiyl compounds appear to be produced in a similar manner, by
i^iwtiniTig arsenious oxide with an alkaline valerate or butyrate. The compounds con-
taining 2 and 8 at of aloohol-radide, e. g. cacodyl and arsentriethyl, haye been obtained
in the free state ; the rest only in combination.

The oompoon^ containing 1 at alcohol-radide, such as As(CH'), are di-atomic and
tetr-atomic, uniting with 2 and 4 at CI, I, &c. ; those with 2 at alcohol-radicle,
caeodyl, for examj^e, are mono- and tri-atomic; those with 8 at alcohol-radicle,
As(CH.*)^for example, are di-atomic ; and those which oontaiu 4 at alcohol-radide^
t.g. As(C'H*)*, ore monatomic and triatomic; (See Oboano-mbtaluo Bodies.)

Arilriflsg of AllyL When iodide of allyl is heated with arsenide of potas-
sium, a number of liquid products are formed, having an extremdy ofTensive odour,
and rising gradually in boflin^ point, so that their separation cannot well be effected,
and at the same time, a sohd crystalline mass is formed, which appears to be the
iodide of arsenallylium or tetrallylarsonium, As(C'H*)*L (Cahours and
Hofmann, Phil Trans. 1867, p. 336.)

Jli««BiA«s of AmyL Iodide of amyl distilled with arsenide of potassium,

S'elds compoonds analogous to the arsenides of ethyl and methyL (Cahours and
iche.)

Jlrsoaldeo of BlIijL*

Three of these compounds, viz. arsendiethyl^ As(C*H*), arsentriethyl^ As(C^*)', and
ar9enetkyUum, As((7H*y, are obtained by a process similar to that already described
for the preparation of stibtriethyl (p. 341), viz. by subjecting arsenide of sodium mixed
with quarts-sand, to the action of iodide of ethyl in an atmosphere of d^ carbonic
acid gas. The action takes place without external heating, and when it is finished, the
resulnnff arsenides of ethyl may be separated one from the other either by fractional
distiQation, or by treatment with etnex. Arwnethylf AsC^H*, is obtained by the
decomposition of arsendiethyL

Absbitbthti^ or Absbnhonbthtl, As(G*H*) a AsR — This radide is not
known in the free state ; but the di-iodide is obtained (together with iodide of ethyl),
by the action of 2 at iodine on 1 at iodide of arBendiethyl, or of 8 at iodine on 1 at
azsendiethyl:

AaS?1 + I« = EI + AsEP
AsE« + I" « EI + AsEP.

The di-iodide distilled with 2 at. iodine^ yields tri-iodide of arsenic (AsEI' + P »
EI -f AsP). Treated with excess of oxide of silver and water, it is converted into
arsenmonethylic acid, A8(C*H*)H'0'. (Cahours, Compt rend. 1. 1022 ; B^p.
Chim. pore, iL 256.)

Absbwdibthtl, or Etrtl-caoodtl, As(C'H^V, is best obtained by treating
arsenide of sodium with excess of iodide of ethyl, m the manner just mentioned,

« Landolt Ann. Cb. Pham. Ixxxix. 301 ; zcii. 96!> $ Gm. Ix. 70; Gerh. ti. 949— Cahours and
Rlcha^ Compt. rend, xxxvi. 1001 ; xxxix. Ml ; Jahre*ber. d. Chem. 1U3, 487 ; 1854, fiaO.~Ca hours,
CoMipc. rand. xtU. 87 } Jahretber. 1859, 430 ; further, Compt. rend. 1. iOXi; K£p. Cbim. pure, 11.355, .

898 ARSENIC-RADICLKS (ORGANIC).

digef ting the crade distillate witli ether, mixiiig the ethereal extiict with absolute
alcohol, expeUing the ether hy eyaporatioB, and mixing the alcoholic aolation with
water, which precipitates arsendiethyl, and retains in solution the iodide of anenethy-
limn, formed by the union of arsentriethyl with the excess of iodide of ethyl

Arsendiethyl is an oily li<mid» haying a faint yellowish colour, strong refracting
power, and a veiy disagreeable, pungent, alliaceous odour. It sinks in water withoot
mixing. Boils between 186® and 190^ C. It absorbs oxygen r^idly from the air,
giving off rapours of arsenious oxide, and if it has been separated by fractional dis-
tillation, it takes fire when a drop of it is let fall'on wood or paper ; bat if it baa been
precipitated by water from the alcoholic solution, it does not take fire till heated to
180® 0. It is rapidly oxidised by strong nitric acid, with eyolntion of light and heat,
less completely by dilute nitric acid, which also forms with it a red substance aaalogoos
to Bunsen*s erythrdrsin, Arsendiethyl reduces the noble metals, silrer, mernny, &cl
from their solutions, and is at the same 'time conyerted into arsetidktiufUe add,
As(C«H*)«HO«.

Arsendiethyl also unites directly with chlorine, bromine, iodine, and sulphur, I^m
compounds are liquids having a peculiarly repulsiye and persistent odour, andattaddng
the eyes strongly ; continued exposure to it produces headache and otiier xinpleaMnt
symptoms. The iodide, Ab(CH^)1, is preptured by saturating an ethereal solation of
arsendiethyl with an ethereal solution of iodine, and eyaporalinff the ether. Itiaa
yellow oil, insoluble in water, but soluble in alcohol and et^er. The alcoholic adatioD
mixed with nitrate or sulphate of silver, yields a precipitate of iodide of ailrer, and a
solution of nitrate or sulphate of arsendiethyl.

On gradually adding a dilute alcohoUc solution of mercuric chloride to an aleoboilie
solution of arsendiethyl, a white precipitate is formed, which however dua^pein
on boiling, and the solution yields on cooling a crystalline powder, oonaiatme of
2Hg^0.As((7H^)^l*. This salt is inodorous, sparingly soluble in cold water and in
alcohol, more soluble in boiling water : it is decomposed by strong nitric add. Tvo
other crystalline compounds are formed at the same time, in small quantify.

Areendiethylic Acid, As(C<H*)*HO'.— When arsendiethyl is triturated vi^
red oxide of mercury under water, mercury separates out, and a solution of anendi-
ethylate of mercury is formed ; and by precipitating the mercuric oxide with baiyta-
water, removing the excess of baryta by carbonic aci^ decomposing the filtered solution
of arsendiethyUtte of barium with sulphuric acid, and evaporating, arsendiethjlic add
is obtained in crystals. This acid is ahso produced by the direct oxidation of arsen-
diethyl, as when that substance is left for sometime in a loosely stoppered bottle; also,
when its alcoholic solution is exposed to the air, or more quickly wnen that Boluiion
is shaken up with oxygen gas. The crystals contain As(C'H*)*HO*. They are
inodorous, have a slightly acid, afterwards bitter ta^e, deliquesce in the air,
and dissolve readily in water and alcohol, sparingly in ether. They melt at
190® C, forming an oily liquid, which solidifies m a crystalline mass on cooling; hot
at higher temperatures, they are decomposed, with evolution of arsenious oxide and
stinking arsenical products. The acid is not attacked by nitric acid, aqua-regia, or by
the milder reducing agents, such as sulphurous acid, and ferrous sulphate ; but phos-
phorous acid reduces it, forming a pungent oily liquid, probably the oxide of orsendi-
ethyL The aqueous solution of the acid readily decomposes carbonates, and precipitate
ferric, mercurous, and cupric salts ; also acetate of lead. The mercuric salt is a d«ii-
qiiescent crystalline mass. The barium-salt, obtained by saturating the aqueoiis add
with barytarwater and evaporating, contains 2BaH0.3As(C*H»)*HO* + JHK); the
water of crystallisation is not completely given off at 120® C.

Arbektbibthtl, or Tbibthtlabsiks. As(CH')'. — ^This is the chief prodaei
of the action 9f iodide of ethyl on arsenide of sodium, and is easily separated from the
other products by fractional distillation in an atmosphere of carbonic anhydride: it
passes over between 140® and 180® G. It is also produced by the action of trichloride
of arsenic on zinc-ethyl (Hofmann and Cahours, Compt. rend. xli. 831). It is a
colourless, mobile, strongly refrneting liquid, having a disagreeable odour, like that of
arsenetted hydrogen. Specific gravity 1*151 at 16*7® C. Under a pressure o{ 736 mm.
it begins to boil at 140® C., but the boiling point quickly rises to 180®, a small quantitf
of arsenic separating at the same time. Its vapour-density is, by experiment, 5*2783;
by calculation ^2 vol.) 5*6156.

Arsentriethyl fumes and becomes heated in contact with the air, but seldom takes fire
unless it is heated : the products of the oxidation arc arsenious anhydride, carbonic anhy-
dride and water. The oxidation takes place slowly, even under water in a closed TesscL
Strong nitric acid oxidises it rapidly, with vivid combustion and explosion, but nitric
acid of specific gravity 1*42, dissolves it slowly, giving off nitric oxide, and produfing
nitrate of arsentriethyl ; but no red compound is formed. This character serrcs to

AKSENIDES OF ETHYL. 3*

distxngoitfh arsentriethyl firom arsendiethyl : a flirtlier distinctioii is afforded by the
ikct that anentziethyl does not reduce the nuble metals from their solutions.

Arsentriethyl is a diacid radicle, 1 at of it uniting with 2 at of a monatomic acid
mdide, €, y. As((^H^)*.P, and -with one at of a diatomic acid radicle, e,g, As(CH*)'.9L

Bromide of A raen triethvl, As(CH^)'Br', is obtained by mixing the alcoholic solu-
tloDB of bromine and anentriethyl, the former in slieht excess, and evaporating at 100^ O,
It is a yellowish, deliquescent, ciystalline mass, the odour of which excit^ sneezing.
When heated it melts, and bums with a white flame. It is decomposed by chlorine,
by nitric acid, and by strong sulphuric acid.

Iodide of Arsentrieihyl^ As(OH*)*P, is obtained by mixing the ethereal solutions
of its ooDstitaents : it is then deposited in yellow flakes which rapidly turn brown and
Hqnefy on exposure to -the air. It dissolres readily in water and alcohol, sparingly in
ether.

The chloride appears to be formed in small quantity by the action of hydrochloric
acid on the oxide or sulphide.

Oxide of Araentrietkyl, As(C^^)'0, is produced when an ethereal solution ot
anentriethyl is left to eyaporate in the air ; but it may be obtained in a state of greater
parity by exhausting the mass produced by the action of iodide of ethyl on arsenide of
sodium, first with ether, and then with alcohol, eyaporating the alcoholic solution, and
<li«d1Kng the residue. It is an oily liquid, heavier than water and not miscible with
it, but soluble in alcohol, and precipitated from the alcoholic solution by water. It
disBolTee in dilute nitric acid, but not in sulphuric or hydrochloric acid. When left
for some weeks in a loosely stoppered bottle; it is gradually converted into an inodorous
OTstalline substance [probably arsentriethylic acid].

Sulphide of Arseniriethylj As(CH*)'S, is obtained by boiling an ethereal solution
of aisentriethyl with flowers of sulphur. It forms beautiful prismatic crystals, which
may be purified by recrystallisation from boiling water or alcohol, or better by
solution in warm ether, and gradual evaporation. It has a bitter taste, but is quite
inodorous when pure. It melts at 100^ C., and decomposes at a higher temperature,
giving off spontaneously infiammable vapours. It is rapidly oxidised by strong nitric
add. Dilute hydrochloric acid decomposes it partially, giving off small quantities of
hydrosulphuric acid and chloride of arsentriethyty recognisable by its peculiarly pungent
odour. It is not decomposed by boiling with cattettc potash. Its aqueous solution
precipitates metallic solutions like an alkaline sulphide.

As8SXBTHTi.itrx or TBTBBTHTLAfisoNiuM, As(C^H'y, IS uot knowu in the free
state, but is obtained as an iodide by the action of iodide of ethyl on azsentriethyl ; also,
according to Cahours and Riche, by the action of metallic arsenic on iodide of ethyl.
Its compounds are analo^us to those of tetrethylium, and contain 1 at arsenethylium
with 1 at of a monobasic acid radicle, or 2 at arsenethylium with 1 at of a dibasic
acid radicle. The hydrate^ obtained by the action of oxide of silver on the iodide,
is a fixed base resembling hydrate of potassium, and dissolves readily in acids, forming
salts which crystallise reamly, are permanent in the air, have a bitter taste, and do
not appear to be poisonous. In this respect, they differ remarkably from the com-
poun<u of arsendiethyl and arsentriethyl.

Bromide of Arsenet hy liuMf As(CIi^)*BTf is a white, deliquescent, saUne mass,
which dissolves easily in water and alcohol, and exhibits with acids and metallic
salts, the same reactions as bromide of potassium.

Chloride of Arsenethylium forms crystals containing As(C*H*)*C1.4H*0,
which dissolve* readily in water and alcohol, but ajre insoluble in ether. The aqueous
solution immediately precipitates chloride of silver from the nitrate and forms an in-
soluble double salt with mercuric chloride. With dichloride of platinum it forms the
compound As(C'H^)*Cl.PtCP, which dissolves very sparingly in cold, somewhat more
reamly in boiling water.

Iodide of Arsenethylium^ As(C'H*yi, forms large colourless crystals, easily
soluble in water and alcohol, but insoluble in ether. When heated, they fall to
powder, give off spontaneously infiammable vapours, and yield a sublimate of arsenic
They are decomp<^ed by nitric and by sulphuric acid. A compound of iodide of arsen-
ethylium and iodide of arsenic is oDtained by heating iodide of ethyl to 100^ C.
with metallic arsenic :

4CH*! + As« - As(C«H»)«I.AsI«.

This compound forms splendid red tables, which are decomposed by distillation, yield-
ing iodide of arsentriethyl and iodide of arsendiethyl (Cahours and Riche, Compt
rend, ^-g^*, 546). It is also decomposed by hot potash-solution, yielding iodide of
anenethylxum, iodide of potassium, and arsenite of potassium. Iodide of arsenethylium

400 ARSENIC-RADICLES (ORGANIC).

iieated with iodide ofgina, jields the compoimd As(0^*yLZ&I ; simOailj trith id^de
ofcadwium,

Aisenethylium likewise fonoB a trt-iodide, Afl(C*H*)*P, analogous to the tri-iodide
of tetrethyhum diflooyered by Weltsden. (Cahours^ Compt rend. 1 1022 ; B^ Chiot
pore, ii 255.)

The atU^haiet [AB(C*H*)^ir|SO^ is formed by precipitating a solution of the iodide
with an acid solution of sulphate of silver. Granular oystals, easily soluble 'm -wtia
and alcohol, sparingly in ether, and decomposed by heat, with evolution of add Tapoms.

AbSBN-BROXBTHTL-TBISTHTLIUX, or BBOXBTHTL-TBIBTHTLABSOKITriL

As(CH^Br)(CH*)'. — The bromide of this radicle is obtained by heating a mixtoze of
triethylarsine with a very large excess of dibromide of ethylene, in sealed tubes it a
temperature not above 50^ C, extracting the product with water, evaporating andreajB-
tallising from boiling alcohol. It forms beautiful crystals, extremely soluble in vater,
the form of which exactly resembles that of the corresponding phosphonium-eompoimd
(see Fhosphobus-radiolbs, Oboanic). It contains the elements of 1 at dibzomide
•of ethylene and 1 at triethylarsine :

(m*Br» + As(C«H«)« « [Afl(C«H*Br)(C«H»)>]Br.

Nitrate of silver added in excess to the solution of the bromide, precipitates only lulf
the bromine ; the other half is precipitated on treating the filtrate with ammooia
(see AiofONiuiE-BASBS, p. 196). The platinum-salt of this radicle foms ^lendid
yellow needles, sparingly soluble even in boiling water. (A W. H of ma no, Vtie. Boy.
8oc xi. 62.)

ABSBNVINTL-TBIBTHTLIirif, Or VlNTL-TBTBTHTLABSOKIUX. AsipW)

(CH*)'. — ^The hydrated oxide of this radicle is obtained by treating bromide of bto-
met^yl-triethyhuraonium with excess of oxide of silver :

[As(C«H^r)(C«H»)»]Br + AgK) « As(C»H»)(C?^)«|q ^ ^^^

A strongly alkaline solution is obtained which, when treated with hydrochloric acid
and precipitated by dichloride of platinum, yields beautifiil, rather soluble oetahedroiu,
containing [AB(C«H*)(C«H»)»]Cl.PtCl*- (Hofmann, loe. cit.)

Ethtlbnb-hbxbthtldiabsokiubl A8*(C*H*)''(C^*)*. — Obtained as a diW
mide or dichloride, by digesting the bromide or chloride of bromethyl-triethylanoDiom
with triethylarsine at 150° C. for two hours. The dibromide rAB«(&B<)''(C^)l"Bi*,

treated with oxide of silver, yields the hydrate [^8*(^'^*)"(C"H^T|ot^ ^ch is a

powerful alkali, and forms with acids a series of beautiful salts :

The platintmsalt [As(C«H«)"(C«H»)«]"Cl*.2PtCl«, is a pale yellow crystalline pre-
cipitate, soluble in water and in boiling hydrochloric acid, from which it oTStallises
on cooling.

The add'Mlt, [A8«((?H*)''((?H»)«a«.2Aua», crystallises ftom hydrochloric add in
gold-coloured plates. (Hofmann, loc. cit. )

Ethylbnb-tbibthtlabsammonium RC'H*)'*^ tJjj^"] . TheiKftnwwfeof

this radicle is obtained by heating the bromide of bromethyl-triethylaisoninm iritli
ammonia to 100^ C. for two hours. Treated with oxide of silver, it yields the eaostie

crystallises from hydrochloric acid in needles, sparingly soluble in boiling water. Tbe
gold'Salt ciystallises from hydrochloric acid in golden-yellow plates. (HofmaDD,
loc. cit.)

The reactions by which the last four bases are obtained are precisely similar to
those which yield the corresponding compounds of the phosphorus series, and will be
more fully considered in the article Fhosphorus-badiclbs (Oboanic), in which also
the phospharsoniumSf containing both phosphorus and arsenic, will be described.

Aubabsenbthtlium, As(C*H*)*Au, and Platabsbnbthtlium, A8(CH')Pt—
The chlorides of these compounds are obtained in fine crystals by treating an alcofaolie
solution of arsentriethyl with trichloride of gold and aiclilorido of platinum respec-
tively. (Hofmann, Ann. Ch. Pharm. cvii. 357.)

Arsenides of Blethyl.

Cadet discovered, in 1760, that by distilling acetate of potassium with arsemoos
oxide, a fetid brown-red liquid is obtained, which takes fire on exposure to the air.
But the nature of this liquid was not understood till Buns en undertook its examinationi
and showed that it contained a metalloidal radicle, AsC'H', to which he gave the
the name Cacodyl (from kokos, bad) on account of its extremely poisonous quali^

ARSENIDES OF METHYL. 401

Bviiseii, moreoTer, isolated this ladide, and prepared a great number of its compounds,
showing that» in its chemical relations, it is precisely analogous to a simple metaL
Thia w&B the second instance of the isolation of a compound radicle, the separation of
mnogen by Gay-Loasac having been the first It has since been shown by Gahours and
Biche(Compt rend, zxziz. 341), that cacodyl or arsendimethyl, Ab(CH*)' may
be obtained by the action of iodide of methyl on arsenide of sodiun, otiier arsenides of
methyl, tis. As(GH*^* and As(CH')* being formed at the same time. I^wtly, Baeyer,
has obtained seyerai oomponnds of arsenmonomethyl, AsGH*.

AssBHXBTHTL, OF Absbnkonoxbthyl, AsCH' » AsMc. — (Baeyer, Ann,
Ch. Fharm. crii 279.) The diehloride of this radicle (which is not known in the sepa-
rate state^ is prodnced either by the decomposition of trichloride of arsendimethyl
(cacodyl) by heat:

AsMeHJl* - AsMea* + MeCl
Trichloride of Diehloride Chloride of
caa>4yl. arienmethjrl. methyl.

or by the action of hydrochloric add on cacodylic add :

AaMe*0«H + 8HC1 - AsMeQ* + MeCl + 2H*0.

When a sfsream of dry hydrochloric acid gas is passed over cacodylic add, basic per-
ehknide of cacodyl (p. 408) is first formed ; bnt by the continued action of the gus,
this oompomid is also decomposed, with separation of water, which paasee oyer in the
distillate, together with the diehloride.

Biehkode of arsenmethyl is a colourless, heavy, mobile liquid, having a strong
lefraoting power. It boils at 133^ C., which is nearly the boiline point of tri-
dikncida of aneni& It does not fume in the air, and is not decomposed by water, but
dissolyeB rather freely in that liquid. It forms a white precipitate witii sulphuretted
hydit)giaL The vapour of this compound exerts a most violent action on the mucous
membranes : on smelling it, the eyes, nose, and the whole fiaice swell up, and a peculiar
iMiwrntting pain is felt, extending down to the throat

Tetrachloride of Arsenmethyl^ AsMeOl^ — When dilorine is passed oyer a
mixtnre of diehloride of arsenmethyl and sulphide of carbon cooled to ~ 10^ C, large
cxyrtala are obtained, which immediatdy decompose at temperatures near the freezing
point of water, yiddine chloride of methyl and trichloride of arsenic : hence the
crystab consist of tetracmloride of arsenmethyl :

AsCH»Cl« - AsCl> + CH«a

Chlorohromide o/ Arsenmethyl^ AsMeGlBr, appears to be produced by the
apontaneoaa deoompodtion of chlorodibromide of cacodyl, bromide of methyl being
gjiven ofiT at the same time :

AsMeKHBr* » AsMeClBr + HeBr;

but the Uqmd product of the decompodtion is too unstable to admit of an examination
of its pn^ertaea.

Iodide of Arsenmethyl, AsOU'P, is obtained by the action of hydriodic add on
the aloi^olie solution of the oxide (see bdow). The liquid yidds by spontaneous
euspanHon, shining yellow needles of the iodide an inch long. They are not altered
by contact with the air, but appear to decompose dowly by keeping (Baeyer). The
same compound is produced l^ the action of 2 at. iodine on iodide of cacodyl, or of
3 at. iodine on fr<M cacodyl, iodide of methyl being set free at the same time.
(Cahonri^ Compt rend. L 1022) :

AsMe*I + P — Hel + AsMeP
AsMe> + P » Hel + AsMel*

It mdts at KP C, and often remains liquid for a long time after cooling. It is colourless
and volatile vrithont deoompodtion aboye 200^ G. It is but slightly soluble in water,
but dissolyes readiW in alcohol, ether, and sulphide of carbon ; less readily, however,
in ptesenoe of free hydriodic add. Hydrochloric add conyerts it into chloride, and
hyoroeuj^urie add into sulphide of arsenmethyl (Baeyer.) Distilled with 2 at.
iodine^ it yidds iodide of methyl, and triiodide of arsenic, Asl*. (Cahours.)

Oxide of Arsenmethyl^ As(OH')0, is produced by the action of potash on the

AsMea* + 2KH0 - AsMeO + 2£:a + H*0;

but on ^MfilltTtg the product with excess of potash, complete deoompodtion takes place
and oxide of caoodyl is obtained, instead of oxide of arsenmethyl (see bdow).
VaL.L D I>

402 ARSENIC-BADICLES (ORGANIC).

A better vunlt 10 obtained by sfttanting the dieUoride with carboiiate of potaMunn,
then addiiig an excess of the latter, extracting with abeolate alcoho], distiUing off th«
alcohol in a stream of carbonie acid, diflesting the residue in snlphide of eaxboo,
which leaves chloride of potassinm and ouier imparities nndiseolyed, and leaving the
dear solution to en^wrate. Oxide of aiaenmethjl is then obtained in large eoiiical
crvstAls (not regolar, however), which soon become dull, and assume the Mpeet o€
wnita porcelain; sometimes, however, aystals are obtained which retain their tmi»-
parency, bnt they are then vexy imperfectly devdoped. The oxide is veiy heavy,
permanent in the air, and has a strong odonr like that of asafoetidai. It oissolves
slowly but abundantly in cold water, ret^y in hot water, also in alcohol, ether, and
sulphide of carbon. It melts at 95^ C, and remains liquid for a considerable time
aftep cooling. It is decomposed by distillation, and the evolved vapours explode when
mixed with air. A portion volatilises, however, with the vapour of water or alcohoL
By distillation with hydrate of potassiumi it is resolved into arsenious oxide and oxido
of cacodyl :

4As(CIH«)0 - Afl«0« + Ab\CIP)K>.

The oxide appears to possess rather basic than acid properties, as it does not unite
with baxyta, but dissolves readilv in adds ; its aqueous solution is neutral to vege-
table colours. Hydrochloric acid added to the coocentrated aqueous solution throws
down the chloride of arsenmethyl in oily drops ; hydrobromic aM acts in Hke manner ;
hydriodic acid produces a yellow predpitate of the iodide ; and hydrondfknaine add a
white predpitate of the suphide. The oxide is not acted upon by hydrogranie add,
but is easily raised to a higher stage of oxidation by niMe acid, merewio oxide, or
sUvcT'Oxide, Chlorine, bromine, and iodine added to its solution in sulphide of
carbon, form predpitates which soon decomoose. Corrosive sublimate does not appear
to unite with it

Areenmethylie acid, Ab(GH*)H'0'. — The barium-salt of this add is obtained
by decomposing the dichloride of arsenmethyl with a slight excess of silver^oxide ;
filtering from ^oride of silver; treating the filtrate with excess of bazyta-water ; re-
moving that excess by carbonic add ; evaporating the filtered liquid to diyness over
the water-bath ; dissolvine the reddue in a small quantity of water ; and prodpitating
by alcohol.. The same salt may be obtained by decomposing the aqneous solution of
oxide of arsenmethj^ with mercuric oxide (for which purpose the alcoholic distillate
obtained in the proparation of the oxide, vid. sup. mav be used), deeomposing the
resulting mercurous salt with banrta, and proceeding as before.

By caiefuUy decomposins the biuium-salt with sulphuric acid and evaporatins the
filtrate over the water-batn, arsenmethylic acid is obtained in the form of a umi-
nated mass, resembling predpitated nitrate of urea. It is purified by solutioB
in hot alcohol, and ciystallises, on cooling, in large spear-shaped lamin»^ composed of
small needles, united in arborescent groups, permanent in the air, and not containing
any water of ciystallisation. It is a strons acid, having a pure, sour, agreeable, tastei,
and capable of decomposing carbonates. It is very soluble in water, and dissolves in
alcohol moro readily toan cacodylic add. All its salts dther ciystallise or fbnn pn*
cipitutes. It is a dibanc add, the formula of its normal salts being As^CH')0OP.
The bariumsaltt prepared as above, ciystalliBes in colourless needles, containing 10 at.
of water, which it gives up at 100° 0. The anhydrous salt separates as a white powder,
composed of rhombic crystals, when the concentrated aqueous solution is evaporated
or mixed with alcohoL On examining with the microscope the pedpitate produced
by alcohol, the rhombie crystals are seen to change in a few mmiites into the long
needles of the hydrated salt. The salt is quite insoluble in alcohol, and may thus be
easily separated firom cacodylate of barium, which is soluble in that liquid. Jrmih^
methylate of silver, As(CH')0*Ag*, is predpitated in small czystds, having a strong
nacreous lustre, on mixing the neutral solution of the barium-salt with nitrate of silver.
It is an^drous, is but little altered by exposure to air and light, does not decompose
at 100° 0., but explodes at higher temperatures, with rather strong detonation.

Sulphide of Arsenmethyl, As(CH^S.— Obtamed bypassing anlphnzetted hy-
drogen into water in which dichloride of arsenmethyl is immersed:

A«(CH»)a* ^. H« - As(CH«)S + 2Ha

The chloride is then converted into a white mass of tiie sulphide^ without the slightest
separation of sulphur. The product is dissolved in a mixtiire of alcohol and sulphide
of carbon, from i^hich it crystaUises by rapid evaporation in shining 1*wi>iii or \j
slow evaporation in small prisms. It is insoluble in water, moderately soluble is
alcohol and ether, very soluble in sulphide of carbon. In the crystallised stats, it
melts at about 100^ C, but often remains fiuid for a long time after cooling. It it

ARSENIDES OF METHYL. ^ 403

decompdeed bj heat, with sepamtion of sulphide of araenio. It ia permanent in the
air, and has a fieont odour like that of aaafoetida. The alcoholic solution daoomposes
the salts of ailTer^ copper, lead, platinum, and marcnzosum, with formation of mo-
talUe sulphides, and proauces a white oloud with mercuric chloride.

Absbxdimsthtl or Caoodti^ As(OH*)* — Kd-^Oadet, GrelL N. Ohem. Arch.
i. 212; Bunsen, Pogg.Ann. zL 219; xlu. 145; Ann. Ch. Fharm. xzzrii. 6; ^riii 19;
Baeyer, Ann. Ch. Phann. cyii 267. — Grm. ix. 316; Gerh. i. 626.)— -This body, together
with the products of its oxidation, constitutes the spontaneously inflammable Uquid,
known as Cadets fuming liguid or alkarsin.* To prepare this liquid, a mixture of equal
parts of acetate of potassium and arsenious oxide is distilled in a retort provided with a
receiTer, from which a long tube passes into the chimney, to carry away the poisonous

gases erolred during the process. The retort is placed in a sand-bath and gradually
eated till it is red-hot at the bottom. A brown oleaginous liquid consisting of im-
pure eaoodyl is then foand in the receiver, together with metallic arsenic, and a
mixture of watec; acetone, and acetic acid, which floats on the top. The reaction is
Tery complicated, considerable quantities of carbonic anhydride and hydride of methyl
(manh-gas) being given oS, together with other eases in smaller quantity; but the
formation of cacodyl is evidently connected with the splitting up of acetic acid at a
red heat into carbonic anhydride and hydride of metiiyl (p. 12). ^e oily liquid,
which is very inflammable, is decanted by means of a syphon, the longer arm of
which dips nnder water. It is then washed with boiled water and distilled over
hydrate of potassium in a current of hydrogen.

Pore caeodyl is obtained by decomposing the chloride with metallic zinc, dissolving
oat the ehlonde of sine by water, and dehydrating the oily liquid, which sinks to
tho bottom, by distillation from chloride of calcium. The strong tendeney of ca-
codyl to take fire in the air and the extremely poisonous qualitv of its vapour, render
it necessary to perform all the distillations in sealed vessels, filled with dry carbonic
acid gas. Bunsen's method is as follows :

1. Chloride of cacodyl is prej^ed perfectly free from oxide, by distilliog alkarsin
with strong hydrochloric acid, till the resulting chloride no longer emits the slightest
fume on earoosure to the air ; or better, by mixing the dilute alcoholic solutions of
ylt^rftin and mercuric diloride, and distilHng the resulting; precipitate of chloroTnercurate
of cacodvl (Kd*0.4HgCl) with very strong hydrochlonc acid To free the distillate
obtained by either of these methods from water and hydrochloric acid, it is digested
for several days with a mixture of chloride of calcium and quick lime, contained m the
bolb-apparatus A (fig, 74). The air is first expelled from this apparatus by a stream
of dry carbonic acid gas ; the lower extremity a is then dipped mto the chloride of
eaoodyl below the hydrodiloric acid; the chloride of cacodyl is drawn into the bulb by
means of a hand-syringe attached by a caoutchouc tube to the upper end h\ and lastly
the apparatus is sealed at both ends and set aside for several days.

2. llie dGGomposition of the chloride of cacodyl is effected in a second apparatus J?,
represented in fig, 76, A moderately strong and rather wide gas-delivery tube is
blown out to a bulb in two places a, 6, about six inches apart ; the lower extremity is
then drawn out and twice bent, as shown at e, d: tne upper bulb a is partly
filled through the wide open end of the tube with small cuttings of pure sine-
foil ; the upper end of the tube is then drawn out and bent, as shown in the figure,
and the wh<ue apparatus is filled with perfectly dry carbonic acid gas. To introduce
the purified chloride of cacodyl into the bulb a, the tube of apparatus A is cut off
•t c, just above the bulb; the upper extremity / of the apparatus ^, is then introduced
into bulb A ; and a quantity of the liquid, sufficient to half fill it, is drawn in by
means of a hand-syringe connected with the lower end f, after which the lower end
of tbe tube is sealed by the blowpipe at e, and the upper end sealed and melted off at y,
cloee to the bulb a. The apparatus is now inverted, and the bulb a immersed m
water at 100^ C. The reduction then takes place without evolution with gas, and
alter some hours, the contents of the bulb a are converted into a white saline mass,
which appears to be a compound of cacodyl with chloride of zinc, and melts to an
fiSij liquid at 110^ — 120^ C. To separate the cacodyl from the chloride of zinc, the

This lh|Qid was tappoted bv Bunsen to. be the oxide of cacodyl, ( AsC*H>)SO« It doei noc appear,
to IM definite in oonsUtutlon. Bunaen*s aoalyset or It vary from 30*9 to SS'4 per cent* in the

cailmi, and from 6&*4 to 66*3 in tlie anenic. Dumai (Ann. Cb. Phyt. {31 viii. 363) found 38 0 and 38*3
aerecBl. cailMa, and from SB'S to ^8 per cent, anenic. Now the formuui of oxide of cacodvl regulrca
Sl-t carboB, and S6-4 anenic while that of eaoodyl Ittelf requires 33*9 carbon, and 714 arsenic. Tbeie
are qjidte in acooidanoe with the suppofUion that Cadet*s Uquid is a variable mixture of cacodyl

imd hs oxide » the spootaaeous Inflammabtlny of the liquid likewlM Indicates the presence of free caco-
dyL TiM trae oxide of cacodyl (Bunsra's paraeaeodifUc •Kide^ p. 407, s«ipposed by him to be Isomeric
wttli aikanin), produced bgr uo* oxidation of eaoodyl or of alkarsin ItoeU, b not spontaoeousl^ Inflam*
(Oerhardt.)

D D 2

404

ABSENIC-BADICLES (ORGANIC).

end e of the apparatiu is broken off under water which has been thoroiiftfaly freed
from air by bomng ; the whole a^paratoB in heated to expel the carbonic anhydride, and
then left to cool, till the bulb b is nearly filled with water; the end e is again sealed ;
the apparatos inclined so that the water may flow into the bnlb a ; and this bulb is
gentiiy neated* The chloride of sine then disBolyes, and the caoodyl sinks to th«
bottom as a heavy oily liquid.

^.75.

To dehydrate the caoodyl and maify it fiirther, it is next transferred, with the sune
precautions as before, into another apparatus A (fig, 7i), the bulb of which oontains
dry chloride of calcium : for this puii)08e, the bulb a of apparatus B is cut off at k^ and
the apparatus A hayine been filled with drj carbonic acid gas, its lower extremity a ie
introduced into tiie bulb a, and made to dip into the cacodyl below the wsteiy liquid;
the cacodyl is then drawn by suction with the minge into the bulb of apparatus A^
which is then sealed at bow ends, and set aside for some time. The ^hydrated
caoodyl is next transferred into a second apparatus b, filled with dry carbonic acid
gas, and havinff some sine-cuttings in the bulb a, and the two arms of the tubes ai<e
then sealed and melted off jjust bdow the bulbs a, h. The bulb h is then immecsed in
cold water ; the cacodyl distilled into it by gently heating the bulb a with a ^trit-
lamp, and tiien poured back ; and the rectification is repeated m this manner two or three
times. Lastly, the bulb b is cooled in a freezing mixture to— 6^ C, and left there till
about I of the lu^uid has crystallised, and the still liquid portiou is poured back: that
which then remains in the solid state is (rare caoodyL ^

Cacodyl may also be prepared by heating the sulphide with mercuxy.

Properties, — Cacodyl is at ordinazy temperatures a transparent colourless^ strongly re-
fracting liquid, heavier than water. It boils near 170^ C. Its Yapour-density (reftfied
to air as unity) is by experiment 7*101, which shows that the rarmula of cacodyl in
the free state is AsH^^H" « As'Me^ « KdKd. For the atomic weight xepieaented
by this formula is 210 (»2. 76 + 4. 12 + 12.1), and if this represents 2 Tois. ci
vapour, the weight of one toI. of Tapour, that is to say, the specific gravity refened to
hydrogen as uni^, is 105; and multiplying this by 0*0693, the soecific gravity of
hydrogen referrea to air, we obtain for the specific gravity of caoodyl-vapour referred
to air as unity, the number 7*2755, which is very near the numl>er determined by
experiment Cacodyl has a disgusting odour, somewhat like that of arsenetted hydro-
gen, and its vapour is very poiBonous. It solidifies at 6^ C.^ in square-based prisms. It
IS sparingly soluble in water, very soluble in alcohol and in ether. Wben healed in a
close vessel to about 400^ C. it is resolved, without deposition of carbon, into m^allia
arsenic, and a mixture of 2 voL marsh gas and 1 voL defiant gas :

As«C*H»» - 2CH* + C»H^ + As«.

Cacodyl takes fire in the air, at ordinary temperatures, even more readily than emdd
alkarsin, yidding carbonic anhydride, water, and arsenious oxide, but if the quantity
of air present is not sufficient for complete combustion, a red compound, Bunsen's
erythrarsin, is formed at the same time. This red substance is also produced

caoodyl is passed through red-hot tubes ; also by the action of protochlorrde of tin,
or phosphorous add on cacodyL It appears to contain C^H^As^O*. Caoodyl

ARSENIDES OP METHYL. 405

to the gndnal aetioii of oxffgen^ as when air is passed into it in snoGessiTe bubbles, is
oonyerted fint into oxide df caoodyl, and afterwards into cacodvlic acid. It takes fiie
in chtorine aas^ and is oonrerted by chlorine-'water into chloride of cacodjL It dis-
solTes ttdj^kur, Ibnnine a protosmphide or trisolphide of cacodyl, according to the
quantity. Fwsung nSphmc odd dissolves it without blackening : the solution ffives
of^ eren in the cold, a considerable quantity of sulphurous add, and yields by distil-
la^on a pirodnct having an agreeable ethereal odour. It dissolves in nitrie acid^
and the solution yields with nUraU of silver a ciystalline precipitate of nitrate of
siWeor and caioodyL

Bromide of Caeodyl, As(GH')9rBEdBr, is obtained by distilling the chlo-
romercurate, As'OH*H).4HgGl, with concentrated hydrobromic add, and is purified
like the chloride. It is ayellow liquid, which does not fhme in the air, and dosely
resembles the chloride, when heated over mercury to a temperature between 200^
and 800^ GL it is decomposed, yielding free caoodyl and mercnrous bromide. Heated
with water it icxnoB an oxyhronUde,

Chloride of Caoodyl, As^GH*}Kn«EdCl.— IVepaied by distilling the chloio-
mercnrate with veiy strong hydrochlorio add, and purified from water and adhering
hjrdrochloric add by placing it in contact with chloride of caldum and quick lime, and
distilling it in the hermetically sealed apparatus (fig, 74) filled with dry car-
bonic anhydride. It is also poduced by the action of chlorine-water on caoodyl. It
is a very mobfle liquid, heavier than water, which does not BoUdify even at— 45^ C.
It boals a little above 100^ C, forming a colourless vapour of specific gravity 4*56
(by calculation 4*85). It does not fume in the air, but emits a very pungent intoxi-
cating odour. The vapour mixed with air produces, when inhaled in rather large
quantity, swelling of the mucous membrane of the nose and extravasation of blood
in the eyes. The vapour evolved from the boiling liquid takes fire spontaneously
in the air, and explodes violently when heated with oxygen gas.

Chloride of cacodyl is insoluble in vtater and ethers but somble in all proportions in
aleokol, Suljpkurio and phoepAorie €U!ids decompose it, eliminating hydrochloric add.
Strong nUrie acid sets it on fire. It bums in chlorine gas, with copious deposition of
charcoal. Zine^ tin, and iron decompose it^ setting the cacodyl free. Wiu tUcoholio
potaeh it yields diloride of potassium, and an ethereal liquid having a disagreeable
odour, and nusdble in all proportions with water and alcohoL Mixed with solution of
nitrate ofeHver, it gives up the whole of its chlorine, forming a predpitate of chloride
of sflver.

A eybeklaride or oxyckhride of cacodyl^ KdCLjrEdK), is obtained by the action of
water on the chloride, also by distilling alkarsin with dilute hydrochloric add, rectify-
ing the product over a mixture of chijk and water, and redistilling in an atmosphere
of carbonic anhydride. It is a Uquid which resembles the chloride, has a very offensive
odour, and boils at 109^ Ol, ^rinff off a vapour Of specific gravity 5*46.

CSktcmcuprite of CoocM^y/, %dClCu*Cl, is obtained as a butt^ white predpitate, on
mixins an alcoholic solution of chloride of caoodyl with a solution of cuprous diloride
in hy3rochlorie add. In contact with the air, it turns green, and gives off very fetid
anenieal vapours. It is decomposed by heat into its component chlorides.

CUaroplatinate of Cacodyl. — ^An alcoholic solution of chloride of cacodyl mixed with
diehloride of platinum, yields a red-brown predpitate, probably consistini^ of AsCHK^L
PtCP ; but on boiling this product with water, a yellow solution is obtamed, which on
cooling, depodts ciystals of a new compound, viz. :

Chloride of CacopUUyl, AsC^^PtCLHK), or rather A8(?H^tK3.H'0, that is to
aaj, the chloride of a radide, cacoplatyl, formed from cacodyl by the substitution
of 2 at. platinicnm (pt. « 49*9) for 2 at. hydroeen. It appears to be formed from
chloroplatinate of ca^yl, by abstraction of 2HCL This salt forms needle-shaped
oystais, whidi are inodorous, have a nauseous taste, and are soluble in hot water and
aleoboL Ammftniii dissolves it in all proportions, and the solution when evaporated
yields indistinct crystals insoluble in alcohol. Chloride of cacoplatyl sustains a tem-
perature of 164^ C. without decomposing, merdy giving off 4 per cent, of water,
which it takes up again when boiled wim water. At higher temperatures, it turns
brown, and then oums away, giving off arsenical vapours and leaving srsenide of
platinum. Chloride of caooji^tyl is not attacked by hydrochloric add; sulphuric
add colouzB it yellow. With iodide and bromide of potassium, it forms yellow,
psedpitates of iodide and bromide of caeoplalyl, jnedBelj similar in compoeition to
the (mloride. With nitrate of silver, it forms a predpitate of chloride of silver, the
liquid remaining neutral. Boiled with sulphate of silver, it also forms chloride of
luver, and the filtered solution evaporated in vacuo yields white crystalline grains of
S9dpktae of cacoplatyl, (AsC«HVt»)*^0*. (Gerh. i 642.)

DD 3

406 ARSEKIC-RADICLES (OB&AKIC).

TViehtorids of Cacodyt, As(Ci^yCn^,^T^ 1. Bjtheftctio&ofpondilorideof

phosphortii on eaeodylic add :

KdO«H + 2PC1» - Kda« + 2Pa«0 + HCL

The chloride of i^oephonis miut be immened in anhydrous ether, the eafiodylie idd
in powder added by emaU portions at a time, and the action modented hy eztenai
eooiing.— 2. By the action of chlorine on the monochkride. The latter eonqxNuid,
when bion^ht directly in contact with chlorine gas, takes fize and imdergoei compitte
decomposition ; bnt if chlorine be led on to uie snrface of a solution of the mono-
diloride in sulphide of carbon externallv cooled, the trichloride is formed in oyBtaUine
laminiB, which may be purified by washing with sulphide of carixm.

The trichloride, prepared by the first method, forms beantiflBl large prismstie cryi-
tals, which, however, are Teiy unstable, being instantly decompose^ at tempentaxes
between 40^ and 60^ C^ into chloride of methyl and dicUoride of arsen-moiiomeflijl:

As(CH»)«.Cl« » As{CH«)a« + CHH3L

The decomposition takes place spontaneously in the course of a day at ordinaiy tem-
peratures, even when the compound is enclosed in sealed tubes. The ctystals obtaioed
by the second method are much more stable.

Trichloride of cacodyl dissolves without decomposition in anhydrous ether, and sept-
rates by quick cooling of a warm saturated solution, in lamins, by slow oooling; or
spontaneous evaporation, in transparent colourless prisms, which, however, beeome doll
even in a vacuum. It dissolves less freely in sulphide of carbon, from which it sepa-
rates in large laminse. Anhydrous alcohol decomposes it, forming a syrap, which, hj
slow evaporation, yields dystala of basic perchloride of cacodyl, or hydroehknte of
cacodylic acid :

As(CH»)*a« + 2(C«H».H.O) - As(CH«)«0»H«a + 2C«HKa.

v.— ^ — -^ * r— '

Batlc perchlorUe of Chloride
cacod/U ofechjl.

The alcoholic solution, left to evaporate, gives off a substance, probably cficiUofuIro/
arsen-TMmOTMthyl (p. 401^, which acts intensely on the mucous membranes. The tri-
chloride fumes in moist air, giving off hydrochloric add, and forming basic perchloride
of cacodyL The same decomposition takes place in the ethereal solution whoi ex-
posed to the air, the basic perchloride separating in long needles, the formation of
which may be accelerated by the addition of water or alcohoL 3^e tridiloride di«-
aolves in water, with considerable rise of temperature, forming a solution of eaeodjlie
acid and hydrochloric acid :

As(CH«)H:1« -i- 2HK) - As(CH«)K)*H + 8HCL

The decomposition is exactly similar td the preceding, the basic petchloride containing
indeed the elements of cacodylic and hydrochloric acid :

As(CH»)«0«H«01 « As(CBP)»0«H + Ha

The ethereal solution of the trichloride does not attack mercuric oxide; but on addiu
alcohol, a brisk action takes place, and an oil separates which contains chlorine and
mercury, is soluble in alcohol, and predpitated by ether. On fixrther addition d
mercuric oxide, liie whole solidifies to a mass of corrodve sublimate, and the oomponnd
of that substance with cacodylic add (p. 408). Oxide of silver is also without aetioo
on the ethereal solution. (Baeyer.)

XHbromoehloride of Cacodyl, Ab(CH^)'C1Bi'. — Bromine acts upon monocUoride of
cacodyl in the same manner as chlorine. On adding bromine to a mixture of the
monochloride and sulphide of carbon, the dibromochloride is precipitated in the fora
of a yellow crystalline body, which is even more unstable than the trichloride, heiag
quickly resolved into gaseous bromide of methyl, and a liquid which i^peaia to be
chlorobromide of arsen-monomethyl, As(GH')*.CIBr, but is very unstable. (Baeyer).

2anide of Cacodyl, As(CH^<.CN»KdCy, is obtained by distilling alkaiBD
(t*s liquor) with strong hydrocyanic add, or better with a concentrated loh-
tion of cyanide of mercury; metallic mercury then separates, and cyanide of cacodjl
collects under the^ water in the receiver, in the form of a yeQowiah oil, ^ch som
solidifies in fine prismatic crystals. The liquid is decanted, and the crystals are dried
by pressure between bibulous paper. The crystals are oblique prisms, truncated on the
acute edges, and terminated by dihedral summits. It melts at 33^ C, farnusut a ooloa^
less ethereal, strongly refracting liquid, which solidifies again on cooling. It boibit
140^ C, yielding a vapour of sp^nfic mvity 4*63. It dissolves sparingly m water, nineh
more readily in alcohol and ether. It is intensely poisonous, more so than any othff
caoodyl-compound. A few grains of it diffused in vapour through the sir of a rooo,

ABSENIDES OP METHYL. 407

are snAdent to amte giddineflai detiritim, xrambneM of the hiuidB and feet^ and even
ioae of oonscioiianeBs; theae attacka, however, are of abort duration, provided the
peiTBoii affected make hia eioape in time. Cyanide of caoodyl is not decompoaed by
dilate alkidia^ but eoneetUroM adds deoom|io8e it^ with evolation of hydroeyanio
aeid. With sUtftr'SohUiotu it forma a precipitate of cyanide of ailver. It redocea
aienwrptit mirvte, bat doee not act on mercuric nitrate. With merettrio chloride^ it
forma a white precipitate of ehloromeicmiate of oaoodyL

Fluoride of Cacodyl, Aa(GH^)9 * KdP.— Pkedueedby diatiUing the chloio-
mescunte with hydxoflu<»ie a<ad. It ia a ccdourleaa liquid, whidi haa an offenaive
odoor, and attacka glan.

Iodide of Caeodyi, Aifi(CHFfl » KdL— When alkanrin ia diatilled with concen-
trated hydriodio add, an oily liquid paaaea over, which on cooling depoaita tranaparent
zliombofdal taUea, oonaiating of oxyiodide ofeaoodyL To complete the aepamtion, the
Uquid 18 immeraed in a freezing miztore, then decanted from the cxystala, and afterwardi
dned and rectified in the manner deacribed lor the chloride, the diatillation beins, how-
eTBT, discontinued when two-thirda of the Uquid have paased over. Iodide of cacodyl thus
prepKred ia a yellowiah, aliehtly ayrapy liquid, having a strong repulsive odour. It is
neavier than melted cfaloriae of calcium. It remains liquid at— 10^ C, and boils at a
tcB^eratore above 100^ G. ; neverthelesB it distila with the vapour of water. It does
not fume when exposed to the air, but gradually oxidises and deposits fine prismatio
erystala of eacodyHe acid. It ia soluble in alcohol and ether, but insoluble m water.
Nitric and sulpmerio adds decompose it, setting iodine free. When heated in the air
it bnzita with a daaitling fiame, giving off vapours of iodine.

Oxide of Caeodyl, Ab*C*B}H) » KdK>. (Bonsen's Paraeacodylio Oxide, see p.
403.) — This compound is formed by the slow oxidation of cacodyl ; also by the action of
redocing aeents, such as hydriodic, hjdrobromic, sulphydric, or phosphorous acid,
ptotochh>ride of tin, &&, on cacodylic acid. When air is made to bubble slowly through
aDcaraixi, tbat liquid is gradually converted into a syrup filled with orstals of caco-
dylic acid ; and on dissolving in water the mass thus obtained, and distilling, water
having the odour of cacodyl passes over at first, and afterwards between 120° and
1300 C., an oily liquid, which when dried over caustio bazyta, and rectified out of con-
tact of air, ^elda pure oxide of cacodyl, in the form of a l^pid oil, having a pungent
odour, apanngly soluble in water, and boiling at 120° C. When exposed to the air, it
oxidises vecy slowly, without fdming or rise of temperature, and is converted into
caeodylie add. Air mixed with ita vapour between 50° and 70° C. detonates violently
on the approach of a bominff body. Oxide of cacodyl dissolves in hydrochloric, hy-
driodic, and hydrobromic ados, forming the chloride, bromide, and io<ude of cacodyl.

Ozidie of ca!codyl forms witii mereurie chloride, a white predpitate, which is a com-
pound of the two substances KdH).4H^01. This compound, called chlorom ercurate
of cacodyl, is also produced by mixing a dilute alcoholic solution of alkmnin with
a dilute solution of mercuric chloride, me latter not being in excess. After several
crrataDisations from boiling water, it forms silky tufts, and by slow cooling of the
solution, may be obtained in small rhombic tables ; 100 pts. of boiling water dissolve
8-47 pta. of the compound : it ia also soluble in alcohol, espedally at Sie boiling heat
It is inodorous, but haa a disagreeable metallic taste, ana is very poisonoos. When
heated in contact with the air, it decomposes without leaving any residue. With
hydrochloric^ hydziodio, and hydrobromic adds, it forms diloride, iodide^ and bromide
of cacodyl

Oxide of cacodyl forms with merourie bromide, a compound similar in composition
and prraerties to that just described, viz. the bromomercurate of cacodyl,
Kd'0.4H^r. With nitraU of eilver, it forms the compound 3EdK).2NO*Ag, which
sqnratea in the form of a heav^^, white, crystalline powder, on pouring a solution of
nitrate of silver into a cold solution of alkarsin in dilute nitric add. This compound
BQstaina a temperature of 90° C. without decomposing, but explodes at 100° C, giving
off fetid ars^cal products. With diehloride of planum, oxide of cacodyl forms a
red-brown predpitate, and with ot/amde of mercury a brown pulverulent predpitate,
ibling pancyanogen and smdUing like dried nightshade berries.

Iff Caoodyl, AaO^«0 - KdO, or CacodylaU of Cacodyl, ^\o*—'^^^

is the thick syrupy liquid which is poduced by the slow oxidation of cacodyl or alkar-
sin, and {^adually becomes filled with arvstals of cacodylic add. It is decomposed by
water, and the liquid then yields a distillate of oxide of cacodyl, and leaves a residue
of cacodtvlic add :

4KdO + HH) - KdH) + 2KdO^

Cec^dylie Acid, AsG>H'0< - EdO>.H, or Kd*0*.HK).^Thi8 compound may be

D D 4

408 ARSENIC-EADICLES tORQANIC>

prepared by passing oxveen gas for seyeral days throngli alkazsin ; the greater part of flt«
liquid is then converted into crystals of cacodylic acid, which may be purified by preasnre
between paper and recrystallisation. This mode of piepaiafcion, however, is msagree-
able and dangerous, on account of the inflammability and^ poisonous character of the
caoodyL A safer and more expeditious method is to oxidise alkazsin with mercnzie
oxide. The two substances are placed together under water, in a Tossel extemallj
cooled ; mercury is therein reduced, and caoodylate of mercnzy formed :

Kd 4- 2Hg^ s 3Hg -h KdO*Hg.

More t^lVm-gin is then added, drop by drop, till mercury no longer separates <m hfmtinq
the mixture, and a fiiint odour of caoodyl becomes perceptible ; after iHiicfa the limiid
is evaporated, the residue dissolved in alcohol, and the cacodylic aetd which crystallises
^m the solution is purified by reciystallisation from aloohoL It is then obtained in
large oblique rhomboidal prisms, transparent and colourless. It is inodorous and not
at all poisonous, although it contains 64*86 per cent, of arsenic. It dissolves in water
in aU proportions, somewhat less freely in alcohol, and is insoluble in ether. It is
permanent in diy air, but damp air decomposes it. It is altogether a very staUle
compound, sustaining a heat of 200° C. without decomposition ; at higher tempeira-
tures however, it decomposes, yielding arsenious oxide and other^ arsenical prodnetB
having a very fetid odour. It is not attacked by fuming nitric acid, or by a mixture
of sulphuric acid and chromate of potassium, even at the boiling heat. It is not deoxi*
dised by sulphurous add, oxalic acid, ferrous sulphate, or hydrogen gas; bat when
heated with phosphorous acid, it gives off vapours of cacodyL It is also reduced when its
aqueous solution is boiled with zinc. An acid solution of protoehloride of tin oonTerts it
into chloride of cacodyl Dry hydriodic acid gas, passed over dry cacodylic add, fovms
iodide of cacodyl, water, and free iodine :

KdO'H + 3HI - Kdl -I- 2H*0 + 2L

Dry hydrobromUs add eas acts in a similar manner. With dry hydroehlorie add, on
the contrary, or with tiie concentrated aqueous add, cacodybc add unites directly,
forming the compound EldO'H.ClH. But by exposing cacodylic add for some time to
a stream of hydrochloric add gas, dichloride of arsenmonomethyl is obtained, together
with water and chloride of methyL (B aey er) :

As(CH»)WH + 8Ha « AsCHKJl* + 2HH) + CHK3L

Btdphydric acid, either dry or in a(]^ueous solution, decomposes cacodylic add, widi
rise of temperature, forming disulphide of cacodyl, water, and sulphur:

2KdO*H + ZIPS - 2EdS + 4HK) + S;

but if the cacodyUc add is dissolved in weak alcohol, a considerable quantity of piroto-
sulphide is formed as well as disulphide :

2KdO«H + 3H«S « Kd«S + 4BP0 + 2a

Caeodylates, — Cacodylic acid dissolves metallic oxides, and decomposes eaibonates
with effervescence. Most of its salts are gummy, but few being capable of crystal-
lising. The general formula of the normal caeodylates is AsC'H'MO' b KdOW.
They require a higher temperature to decompose them than the add, and give oJF
stinking products, leaving a residue of carbonate or arsenate. They dissolve in water
and in alcohoL Sulphydric add converts them into the corresponding sulphtheaeod^-
laies KdS'M. With silver, cacodylic add forins a normal salt^ KdO'Ag, amd an aad
salt, KdO>Ag.2KdO*H, both of which crystallise in needles.

Cacodylic add also combines with certain acids.

HydrochloraU of cacodylic add, EdO*H.ClH, called by Bunsen, hasie percUoride of
cacodyl, is obtained by dissolving cacodylic add in concentrated hydrochloric add, and
evaporating in vacuo. It then solidifies in a mass of beautiful lameUated catystala, in-
odorous, but havine a strong add taste (Bunsen). It is also produced by the action
of water or alcoh(3 on triddoride of cacodyl (Baeyer, p. 406). The oompound is
decomposed by water into hydrochloric and caoodyUe adds, and when heated to
200^ C. ^ves off monochlorinat«d hydride of methyl, water, hydrochloric add, and
an oily hquid, leaving a residue of arsenious acid.

On mixing the alcoholic solutions of cacodylic add and mercuric diloride, a eac^
dylate of mercuric chloride^ KdK)*.2HgCl, is predpitated in white shining scales,
which change after a while to slender needles.

Hydrofluoric acid forms with cacodylic add a similar compound, KdO^.FH, which
crystallises in fine prisms. Hydrobromic acid also unites directiy with caoodylie add,
but the compound is a syrupy liquid which does not crystiJlise.

Selenide of Cacodyl, is obtained by distilling chloride of caoodyl two or three
times with aqueous selcnide of sodium. It passes over with the vapour of water, in
the form of a heavy yellow oil, having an extremely offensive odour. It is iIMw>^i^^^»

ARSENIDES OF METHYL. 409

m water, but Bolnblo in alcohol and ether. It has a yery high boiling point It forms
biaek predpitateB vith lead and silifer salts, and with fnercurio ekhride, it yields first
a hlacJC precipitate of snlphide of merctuy, and afterwards, on farther addition of the
nareniy-aaltt a eoptons precipitate of ohloromercnrate of caeodyL

Sulphide of Caeodyl^HJ'K'S -» Xd^, may be prepared by adding a solution of
sulphide of barium to the cmde liquid obtained by distilling acetate of potassium with
aneniooB oxide, or by distilling sulphydiate of barium witii chloride of caoodyl. It is
poriiled by means of carbonate of lead and chloride of calcium. It is a transparent,
colomrlcias, eztremehr fetid liquid, which retains its fluidity at 40° C, and boils at a tem-
perature considerably abore 100°, yielding a yapour of specific grayity 7*72. It is nearly
maohible in water, but mixes in all proportions with alcohol and ether. It does not
fame in the air, but rapidly absorbs o^gen, being converted into dioxide and disul-
phide of cacodyl :

Kd<S + 0 « KdO + KdS.

Hydrochloric add conrerts it into chloride of caoodyl, with CTolution of sulphydric

JCA)
DistUpkide of Caeodyl, EdS, or SulphocacodylaU of caoodyl^ Kdv^*' — Obtained by

the action of sulphur on caoodyl, or on the monosulphides, or bj treating cacodylic acid
wi^ sulphuretted hydrogen in a ressel externally cooled. Bisulphide of cacodyl then
separates, mixed with excess of sulphur, from which it may be separated Ir^ solution
in boiHng alcohol. The solution, if slowly cooled, deposits the disulphide in laree
rhombic tables, but if quickly cooled, in small prisms, soft and greasy to the touch.
The compound has a pungent odour, like that of asa&etida^ is permanent in the air,
and melte at 60° C, forming a colourless liquid, which solidifies in a oystalline mass on
cooling. It is insoluble in water, but dissolves readily in alcohol, yeiy sparingly in
ether. It dissolyes in hydrochloric add without alteration ; in strong sulphuric acid,
with errohition of sulphurous add and separation of sulphur. Nitric add and peroxide
ci lead oonrert it into cacodylic add. Mercury decomposes it| forming protosulphide
of caoodyl, and sulphide of mercury.

Sulpkocaeodylic aeidy AsO*H'S* » EdS'H. — This add has not been obtained in
the firee state, but its salts, EdS^M, are obtained by precipitating the alcoholic solution
of the disulphide with alcoholic solutions of certain metallic salts, or by decomposing
the eaeodylates with sulphydric add. The Uad-salt, EdS'Pb, forms small white
pearly scales, which are mdorous, permanent in the air, not affected by sulphydric
add, insoluble in water, nearly insoluble in aloohoL The cuprous taltj KdS'Cco,
[Geu ■■ Cu*], is obtained by adding an alcoholic solution of cupric nitrate to a large
excess of alcoholic disulphide of caa>dyl, cacodylic add and nitrate of cacodyl bei^
fiormed at the same time :

4KdS +4N0K)a + 2H«0 « 2KdS«Cu + KdO*H + NO«Kd + NO*H.

It is a soft, loose^ ^eg-yellow powder, which is decomposed by heat, and is insoluble
in water, aoueoas adc^ alcohol, and ether. The aniimony'salt, Ed*S*Sb (Sb being equi-
valent to W% o^allises in short lig^t yellow needles, difficult to purify. The
hismtUJk^saU, Kd^S^i, forms delicate, golden-yellow, inodorous scales, which are per-
manent in the air, sustain a heat of 100° C. without decomposition, and are not affected
by sulphydric add. They are insoluble in water, and nearly insoluble in alcohol
and ether. The gfUd-aalt^ EdS'Au, is obtained by mixinff the alcoholic solutions of
disulphide of caoodyl and trichloride of gold, cacodylic add being formed at the same
time, aa a 8oft» yellowish white, tasteless, inodorous powder, which is set on fire by
Btnxnff nitric add, with separation of sulphur and gold. It is decomposed by caustic
potash, but not by sulphydric add. Insoluble in water, hydrochloric add, alcohol and
ether.

Absbvtbimbthti. As(CH*)' and Absbnkbthtliuk As(CH^^ (Cahours and
Biehe^ Compt rend, xxxix. 541.V~When iodide of methyl is dropped by small portions
into a small flask fllled with carbonic anhydride and containing pulverised arsenide of
sodinm, a connderable degree of heat is developed ; and if the additions of iodide of
methyl be repeated till no Auther rise of temperature is produced, and the mixture be
then distilled in a current of carbonic anhydride, four products are obtained, viz. unal-
tered iodide of methyl, a white crystalline body, and a heavy liquid composed of two dis-
tinct compounds, one of which boils at 120° C., the other between 165 and 170°. The
former is arsentrimethyl ; the latter arsendimethyl or cacodyl. The quantity of these
liqmds obtained is but small, even when the matter operated upon amounts to 100

Ar9enirimethyl is obtained pure by the decomposition of iodide of arsen-

410 ARSENIC-RADICLES (ORGANIC.)

methyliuin, t^g. by treating the oompoimd of iodide of anenmetliyliain and iodide of
anenic {yid, inf,) with boiling potiuh-ley, oTaporating to diyncm, and distilling in
an atmos^eve of carbonic anhydride. It is a colourless mobile liquid, boiling bdov
100^ C. It is diatomic. The oxide^ AaMeK), is cmtallisable bat deliqofiecent The
ntlpkide, AaMe'S czystaUifieB from aqueous or aloonoUc solution by slow eTaunition
in colourless prisms. It unites already with iodine and bromine, forming ^ com-
pounds AsMe'P and AsMe'Bz'. (Oahours, Compt rend, zlix 87; Jabresber.
d. Chem. 1869, 431.)

Iodide of Arsenms thulium, — This is the arystaUised body jnst mentioDed,
which is in fact the chief product of the reaction. It may also be obtained bj tlM
action of iodide of methyl upon cacodjrl. On mixing these two liquids in a tnbe, a
Tiolent action takes place, and a yellowish white mass of crystals of iodide of anen-
methylium is obtained, impregnated with an oily matter of the same edLour, eonsiiting
of iodide of cacodyl :

2CH»I + 2As(CH«)« = As(C«H»)*I + AsC«HM

The crystals, freed from the oil by draining and pressure between bibulons pajwr, and
then dissolved in iodide of methyl mixed with idoohol, separate from the aolntion in
the form of beautiful colourless tobies haying a high lustre.

Iodide of arsenmethj^lium boiled with recently precipitated oxide of silver, yields a
strongly alkaline liquid, which, when evaporated in vacuo, yields veiy deliqaewent
czTst^une lamine consisting of the hydrated oxide of areewmetkylivm ; and its adntion
mixed with sulphate or nitrate of silver, yields iodide of silver, and ndphate of aiGen-
methyUum, SO^(AsHe^)*, or the nitrate, NO'AsMe*. These salts are very soluble, big^j
deliquescent, and separate from their solutions by evaporation in vacoo^ in the ibim of
beautiful crystals.

Iodide of Arsenniethylium with Tri-iodide of Arsenio As(CH')*LA6P.—
When iodide of methyl is heated to 200^ C, in contact with metallic arsenic, tbe latto
disappears, and a laige quantity of orange-zed tabular crystals are obtained, BKnatened
with a brownish liquid.

The crystals are decomposed b^ distillation, yielding an oil which haa a penetnting
odour and excites tears. This oil is a mixtore of several substances, the least Tolatile
of which boils at 170^ C, has the composition of iodide of cacodyl, and yields caoodjl
when distilled with amaig«.m of zinc ; the more volatile portion deposits long white
very beautifdl needles, isomeric with iodide of cacodyl.

Iodide of Areenmethylium and Zinc, A8(0H')*LZiiI, is obtained inoolow-
less crystals by heating iodide of methyl with arsenide of zinc It is deoompoeed
by boiling with potash-ley, a heavv oil separating, which solidifies on cooling, m if
this mass be exposed to the air till the free pota^ is converted into carbonate, then
exhausted with absolute alcohol, and the alcohol left to evaporate, iodide of arsec-
methylium ciystallises out in prisms. (C ah ours, Compt. rend. xlix. 87.)

Iodide of Arsenmethylium and Cadmium, A8(CH')*I.CdI, is obtained io
like manner and exhibits similar properties. (Oahours.)

Tri4odide of Anenmethylium, Ab(CH")*P. — ^Analogous to tri-iodide of tct^
ethylium. (Oahours.)

Bromide of Arsenmethylium, — Bromide of methyl acts energetically on
cacodyl, yielding bromide of arsenmethylium in beautiful, very deliqueecent OTatals,
and liquid bromide of cacodyl. (Oahours and Biche.)

Absbkdikethtl-dibthtliuil Ab(0H')*(O*H*)* = AsMe'B'. — (Cahonrs tsA
Biche, Oompt rend xxxix. 544.)

This radicle, like the preceding, has not been obtained in the free state, but the
sulphide, iodide, bromide, and chloride are formed, together with the oorreaponding
compounds of cacodyl, by the action of sulphide, iodide, &c., of ethyl on caooayL

Iodide. A8(0H»)«(C«H»)*I.— When iodide of ethyl is mixed with cacodyl, no
apparent change takes place at first ; but the mixture, when left to itself gndukDj
deposits magnificent crystals of iodide of arsendimethyldiethylium, and likewise yiddn
an oil consisting of iodide of cacodyl :

2EI + 2AsMe> « AsMe*E>I + AsHe^

Bromide and Chloride of ethyl act in a similar manner, but more slowly. To obtain
chloride of areentnethethylium, the mixture must be heated in sealed tabes to 180^
or 200^ 0. ; it then deposits an oil containing needle-shaped ciystals of the chloride.
On distilling the oil and leaving the distillate to cool, these crystals separate in large

ABSCNIDES OF METHTL. 411

qiu&tity. Chkride of anendimethTldietfajlinin forms eryBtalline compounds -wiih
chloride of mercmy, trichloride of gold, and dichloride of platinum.

The Hydrate h formed by treating a solution of the iodide irith oiide of sxlTer; a
fltioDglf alkaliTie liquid is then obtained, which, when eraporated, deposits the oxide
in Teiy ddiqueeoent aystalline scales.

Sulphide, — Sulphide of ethyl acts Teir slowly on caoodyl, and only when heated,
ftrminff crystalline sulphide of arsendimethyldietnylium and a yellowish oil, consisting
rf 8nl]^de of caeodyL

The Sulphate and Nitrate are obtained in the fonn of yeiy deliquescent
oystals, by treating the solution of the iodide with sulphate or nitrate of silyer.

ABSSKTBIXBTHTI.-BTHTLIU1C, AsMe^EI, and Abssnxbthtl-tbtbthtliuii,
AbMbE^. — ^The iodides of these radicles are obtained by treating arsentrimethyl with
iodide of ethj\ and arsentriethyl with iodide of methyl respectiyel^. Botii are
laomorphoaB with the iodides of arsentetramethylium and arsentetrethyhum.

AmsBMDiXBTHTi^DiAKTLiuit, As(C*H*)^OH")' - AsMe'Am*.— The iodide of
this ladide is produced, together with iodide of cacodprl, by heating caoodyl with iodide
of amy] to 18(r^ C. far two or three da^. It drstaUises either in nacreous needles, or
in thin plates. Treated with oxide^ mtrate, and sulphate of silyer, it ^elds the osidet
nitrate, and ndphaie of azsendimethyldiamylium. (C ah o u r s and Rich e.)

The arsenides of methyl and their compounds are related to one another by the fol-
lowing law. If we arrange them in two groups, the one formed on the type of chloride
of ammonium, NH^Gl, the other on that a! ammonia, NH', as in the foUowing tables,
we find that each member of the second column may be deriyed from the one next
aboye it in the first, by abstraction of chloride of methyl ; and each member in the first
column except the highest, may be formed from the one next aboye it in the second,
fay addition of 2 atoms of dilorine, the series extending ficom chloride of aisentetrame-
thjlium to trichloride of arsenic:

T^VWCL

2)£ps»H>.

As Me Me Me Me CI

As Me Me Me

As Me Me Me CI CI

As Me Me CI

As Me Me CI CI CI

As Me CI CI

As Me a CI CI d

As CI CI a

All the reactions indicated in this table haye been actually obeeryed, excepting the
resolution of AsMe^Cl mto AsMe* and Med, and that of AsMe*a> into AsMe'Cl and
HeCl ; but a decomposition analogous to the former of these, appears to take place in
the preparation of the iodides of the arsenmethyls and arsenethyls, the iodide of arsen-
metnykum or arsenethylium being formed at first, and then resolyed by distillation
into iodide of methyl or ethyl, and arsentrimethyl or arsentriethyl, just as iodide of
tetretiyrlium, N(Cm*)% is resolyed under similar circumstances into iodide of ethyl
and tnethylamine.

There is also another relation to be obseryed between these compounds, yiz. that
each of them may be deriyed from the one immediately aboye it in the same colimm,
by substitution of chlorine for methyl ; and hence it appears that AsMe* is monatomic ;
AsMe* diatomic ; AsMe* eitho monatomic or triatomic ; and AsMe either diatomic or
tetratomic ; just as in chloride of propyl, C'H^Cl, the radicle C*H' replaces 1 at. hydro-
gen, whcfeas in ddoride of pri^ylcne, U"H*C1*, deriyed from the former by substitution
ct Id for IH, tliA radicle C^* takes the place of 2 atoms of hydrogen ; and in tri-
dkloriiydrin, C^*C1*, the next term in the same series, CH* (^l^rceryl), takes the
place ^ 3 s^ H. Moreoyer, just as the group CH* is monatomic in the allyl-com-
poonds, and triatomie in the plyceryl-compounds, so likewise As(CH')* is sometimes
monatomic and sometimes tnatomic. The analogy between the two series of oom-
poonds win be more clearly seen from the following tabular yiew :

As(ch^« . a c<H» . a

As(dk»)* . a« d^* . ci«

A8(fiEP)« . a* c^ . ci*

Ai(Ck«)« CL C<H» . a

Similar analogies may be traced in the compounds of arsenic and ethyl, and like-
wise, though not yet ouite so clearly, in the compounds of antimony, bismuth, and
phasDhoms, with the alcohol-radicles. (Baeyer.)--In fact, the compounds of these
OMtuloTdal radicles may, in almost all cases, be reduced to the general types MR'
M^*, MB*, WR\ where M stands for P, As, Sb, or Bi ; and the 3 or 6 at B are made

•412 ARSENIDE OF TETRYL— AETHANITIN.

up, pardj hy an aloohol-radide, partly bj an eqniTalent quantity of chlorine, iodiM,
oxygen, aulplitir, &c (See Oboano-xbtallio Bodies.)

Arsenide ef Tetryl* TttryU or ButyUeaoodyl, Cacodfi of VaUrk AdL—
When yalerate of potaaainm is distilled with an eqnal weight of aneniooa oxide, t
heavy yellowish oil passes oyer, which has a penetrating alliaceous odour, fumes
copioQSiy in the air, but does not take fire spontaneously. It is soluble in irater, foinu
a ttiidc white precipitate with mercoric chloride, and appears to rednoe mercuric oxide
to the metallic state. When left for some time in a loosely doBod yeseel, it changes
entirely into a mass of large, hard, shining, nearly colourless, prisms, which, ifter
drying between filtering paper, are destitute of odour. They haye an acid reaction,
(tissolye in water, and are completely decomposed by nitrate of silver. (Gihhs, SilL
Am. J. [2] xy. 118.)

Arsenide ef THtjI. TrityU or Fropyl-eaeodyh (keodyl ofBu(me Jdd,—'Bj
distilling e^ual weights of bu^nrate of calcium and arsenious oxide, flhaldng up the
distillate with magnesia and water, and rectifying, a heavy colourless oily liquid ii
obtained, which has a disgusting cacodyl-odour, does not fame in the air, hat hams
when set on fire with a white flame and arsenical smoke. The watery liquid yhich
passes over with the oil, appears to contain a considerable quantity of it, and gives a
white precipitate with mercuric chloride, the eaoodyl-odour being at the same time
destroyed. The precipitate dissolves on heatine the liquid, but reappean in small
crystals on cooling. On mixing the solution and the crystals with hydrochloric add
and zinc, the odour of cacodyl reappears, the evolved hydrogen gives off thick ^te
fumos in the air, and deposits an orange-coloured subistanee on cold bodies. The
mixture when heated yields a colourless foetid oil, which fumes in the air, hot ii not
spontaneously inflammable. (Wohler, Ann. Ch. Fhaxm. Ixviii. 127.)

AJUiSVZOSIBBUn* Arsenocrociie. A hydratod ferrioo-calcite arscDate,
occurring at Boman&che, near Maoon, in spherical masses of fibrous texture and ydlov
colour. Its exact composition has not been determined.

AJtSBVXTX or AS8XVO&XTB. Arsenic bloom. Native Arsenicut Oxide,—
A rare mineral, generally occorring in needle-shaped or capillary crystals, also massive,
with spherical and botzyoi'dal sur&ce ; very rarely in regular octahedrons. Specific
gravity » 3*69 to 3*71. Hardness «■ 1*6. It consists of arsenions oxide more or less
pure, has a white to greyish-white colour, occasionally yellow, red, or green; sometimes
covered with a blackish crust (? suboxide or a mixture of arsenious oxide vith metallic
arsenic). It is translucent, with vitreous to silky lustre. It is found, accompanying
ores of silver, lead, arsenical iron, cobalt, nickel, &c., at Andreasborg in the Han;
also at Joachimsthal in Bohemia, Kapnik in Hungary, and in the old mines of Biber
in Hanau. (D an a, iL 139.)

See Sin M ITU.

Syn. with MisnoKm:..

Native diarsenide of iron. (See Ibok, AsssirmBS of.)

Breithaupt's name for a mineral which, according to hint
has the composition of arsenious oxide, but crystallises in forms of the trimetric
system, isomorphous with valentinite. The trioxides of arsenic and antimony sie
therefore isodimorphous.

iiytMTTDOQ'WMm The name given by L. Gmelin (Handb. ix. 315), to the hypo-
thetical compoimd AsH* ( » Ar), analogous to amidogen, NH', formerly supposed
by Laurent, Grerhardt, and Dumas, to exist in cacodyl and its derivatives. Accord*
ing to this view, cacodyl was supposed to be the hydride of a compound, (^Arff,
analogous to ethylene, viz. C^ArW,H\ oxide of cacodyl =» C*Ar£^MO; the pwto»
sulphide « C*ArJP.S3, &c

ASTBAJHITlHv or OTO&ABKZar, a crystalline substance extracted by Saladin
(J. Chim. mM. vi. 417), from the roots of Cyclamen Eurojxgum {Arthanita offiehalif).
. — It is said also to exist in small quantity in the roots of the cowslip (Primuia mis),
of Anagallis arvensis^ and LimoseUa aqitatica. — ^It is prepared by digesting the fresh
roots of cyclamen with alcohol, evaporating the extract, and treating the residae, first
with ether, then with cold water : the insoluble part constitutes arthanitin. It '^
purified by recrystallisation from alcohol, with the aid of animal charcoal It crys-
tallises in fine colourless needles, which are inodorous, but have a strongly acrid apd
styptic taste. It is neutral to vegetable colours, dissolves in 600 pts. of water, readily
in alcohol It is altered at the temperature of boiling water, becoming less srfuUe in
alcohol Kitric acid transforms it into oxalic acid. Sulphuric acid communicates to
it a violet-red tint. Taken internally, arthanitin acts like a purgative, and prodaces
vomiting.

ARTICHOKE— ASAFCETID A.

413

Aooording to Terdeil (Compt. rend, zli 688), the green ook>iir-
ing matter of the artichoke {Cputra acolymtu) and other composite phinta, ia a sub-
stance distinct from chlorophyll, and is formed by the action of the air, water, and
ammonia, on the comminntM parts of the plants. The liquid, which has a fine green
colour, forms with acetic acid a bulky green precipitate, which resembles indigo when
diT, bat when treated with aqueous alkalis, again forms solutions of a beautiM green
coioar.

The artichoke yields, according to Richardson (Ann. Ch. Pharm. Ixvii. Table),
in tiie fresh sfjpite, 1*17 per cent, of ash; in the dry state, 6*2 per cent. In the roots,
stems, and leayes of the Jerusalem artichoke (Hdianthua titberosus) Way and Ogston
(Joom. of Agric Soe. yu. [2] 693) found in the fresh state, 1*79, 1*94, and 16*00 per
cent of ash ; in the same parts when dried, 12*2, 4*4, and 28*8 per cent. The con-
stitnents of the ash are giyen in the fdlowing table :

Artichoke.

Jeruialem Artichoke.

'Root.

Stem.

Laavei.

Potash

240 .

, 66*9 .

. 88*4

6*8

Soda . . . .

6-6 .

•

0*7

. 3*7

Lime • • . •

9-6 .

8*3 .

. 20*3

. 40*1

Kagnesia

4-1 .

1*3 .

1-9

2*0

Sulphuric add (80^ .
Carbontn add (Ca>) .
PhoephofEio add (PK)*)

6-2 .

3*8 .

3*2

11*8 .

26-4

24*8

86*2 !

. 16*7 .

0*6

7*0 .

1-5 .

1-6

. 17*6

Seeqoinzide of iron

06 .

0*9

Chloride of potassium .

6*0

Ghkmde of sodium

8*6 !

• •

4*7

« 1

. 1-8

Seaquiphosphate of iron

4*8

The fruit of this tree, the bread-fhiit tree, which
grows in the islands of the East Indian Archipelago, contains 14 per cent, of starch,
3 per cenL albumin, 19 gluten and woody fibre, and 63 water.

ABVIK BIMJUJhMMVIIM. The fresh tubers of this plant yield, according to
T. J. Herapath (Chem. Soc Qu. J. iii 193), 1*66 per cent, ash, containing in
100 pts. : 61*7 pts. soluble in water, and consistmg of 46*1 K*0 ; 8*1 NaCl ; 38 SO*;
4*7 PHM; and 38*7 pts. insoluble in water, consisting of 18*3 KK); 1*1 Pe^O*;
11-4 PK>», 6*1 SiO«.

The fresh plant contains a sharp milky juice, which pro-
duces inflammation of the skin, but is so volatile and unstable that it is no longer present
in the dried root The dry root is said to contain 71 per cent starch, together with
23 per cent gum and yegetable mucus.

MMUW90 ^'*^^***^ ■'■""' The dry plant yields 4*7 per cent of ash, which
aeeording to Sehnls-Fleeth (Pogg. Ann. Inadv. 80), contains in 100 pts.: 8*6 K*0*
6-«Ca«0; 1*2 MgH); 0*2Fe*0»; 2*8 S0«; 71*6 SiO«; 6*6 C0«; 2*0P'O»; 0*4Naa|

SeeBEMZoor.

Gtnnmi Am faiida, Stinkasant, Teufdsdreck. — A gom-resin
extracted from the root of the Ferula AsafigHdOf an umbelliferous phint growing in
Persia. The root, which is black on the outer surfiice, resembles a luge persnep. On
cutting it transrenel^, the asafoetida exudes in the form of a white luice, like creun, but
on exposure to the air, it gradually becomes yellow and at last dark brown. It is yezy
apt tonm into decomposition; hence, those who collect it carefully defend it from the sun.
The friesh juice has an exoessiyely strong smell, which crows weaker and weaker upon
hteping ; a single dram of the firesh fluid smellB more wan a hundred pounds of the
diy asafietidalvought to us. The Persians are commonly obliged to hire ships on
pamee for its carriage, as scarcely any one wiH recdye it along with other oommo-
ditiea, its stench infecting eveiytlung that comes near it

Aaafcetida is met with, sometimes in small drops or tears, but more frequently in
reddish masses with white streaks. Specific grarity 1*327. Its recently fractured
Bui&oe has but little colour, but quickly reddens on exposure to the air. It is friable
at yery low temperatures, but softens at the heat of the hand. It dissolyes in alcohol
much more readily than in water. It has an extremely disagreeable alliaceous
odour, and a sharp biting taste. It contains in 100 pts., accoimng to Pelletier
(Bull Pharm. liL 666), 66'0 of resin, 19*4 soluble gum, ll*2bassorin, 8*6 yolatile
oil, and 0*3 of malate of caldum. According to Johnston (Phil.^ Mag. Dec. 1838)
the resin of aMfintida» whidb may be extract^ by alcohol, is of a light yellow colour,

414 ASAFCETIDA — ASABUM.

v-hen pure, Vat l!)«come8 purple on ezpoeure to tlie mm. It eontaiBfl about 70*2
per cent^ of carbon, 7*6 of hydrogen, and 22*2 of ozj^ ; no sulphur. AsKfeetida
la used aa a remedy in nervous and hysteric affectiona, as a deobstmeat^ and
eometimea as an anthelmintic. It is aaid to be used also by some Aaiatie tribes aa a
condiment.

Oil of Mfufrntida, — AaaloBtida distilled with wateryielda about 8 per een*. of a
sulphuretted essential oil, to which its odour is due. This oil is neutral, begins to boil
between 136^ and 140^ C, and when left at rest^ giTee off a considerable quantity
of sulphydric aeid. HI as i wets (Ann. Oh. Pharm. Ixsi. 23) obtained ^m it by ana-
lysis, from 64*2 to 69*3 per cent, carbon, from 9*1 to 10*5 percent hydrogen, and 20*2
to 25*5 per cent sulphur, its composition yarying with the time elided sinoe its
-preparatioi). Hlasiwetz regards it as a Tariable mixture of the two oomponnda
C"H"S' and C"H"S. When it is treated with oxide of silyer, sulphide of silTer
is formed, and the liquid, if afterwards rectified, contains 66*6 per cent C, 13*1 H,
and 24*8_S. On agitating it with strong solution of potash and hydrate of lead, and
then rectifying, an oil is obtained haying an odour of layender or rosemary, and con-
taining about 60*7 per cent 0, 9*6 N, and 29*86 S. An oil haying the aame compo-
sition IS obtained by passing sulphurous acid gas through tlie crude oU.

The alcoholic solution of oil of aaaibtida fonns with dichloride of platairam, yeDow
or brown precipitates yazying in composition, according to t&e stren|;th of ^e aomtions
and the duration of the action, but all containing the aameproportiona of carbon and
hydrogen as the oil itself, yiz. (5*H".

On miidng concentrated alcoholic solutions of oil of asafcBtida and chloride ot mer-
cury a white precipitate is formed, which is partly dissolyed bj boilingalcohol ; and
the solution on cooling yields microscopic dystals containing ^C'W^SJI^Q +
20'H*'01*iHg€^ The portion of the precipitate insoluble in alcohol, bladiena when
treated with potash, a proof that it contains mereurous chloride : it was foimd to
contein 0*H"S'.H^S.4^^1.4%^0L Both these mercuiy-compounds, when tiealed
with sulphoeyanato of potassium, yield a yoktile oil smelling like oil of mustard, and
nke that oil, forming a crystalline compound with ammonia : it doea not howerer
contein allyl, but prol^bly the homologous radide, 0*H'^ (Hlasiwetz, Hand. d. C^ian.
2** Aufl. il 339.)

m^M'mmmr or MMAMOmM, O^H^O*.— This substance is contained in the mat of
asarabaoea (Asarum ettropaun^ and passes oyer in the crystalline form when the diy
root is distilled with water. The ciystals beSong to the monodinic or oUimie pria-
matic system, and resemble camphor in taste and odour. Asaione melte at 40^ 0., begins
to boil at 280^, and may be sublimed in small quantity between two wateh-^aasea.
It is insoluble in water, but dissolyes readily in alcohol, ether, and essential oils.
When it is boiled for some time with alcohol, the solution gradually turns red, and a
portion of the asarone is conyerted into an uncrystallisable, resinous, isomeric modfica-
tion, which does not distil with ya^ur of water, and decomposes at 300^ 0. Nitric
acid conyerto asarone into oxalic acid. It is dissolyed with red colour by strong sul-
phuric acid, and reprecipiteted by water. It is strongly attodced by dilorine, giving
off hydrochloric add, and yielding a thick oil whose composition appzoximatee to tke
formula 0»H«01«0». (Goertz, Ffaff 's System 4. HateriaMedica, iy. 229 ; Blanehet
and Sell, Ann. Oh. Pharm. yL 296; Schmidt, ibid. liii. 166.)

A camphor-like substance found, together with asarone, in tiia root of
Asarum ewropuam^ and resembling that substance in many respects, but differing finm
it in appearance, in not decomposing so readily when sublimed, but d^iefly in its rndting
point which is 70^ 0. whereas that of asarone is 40^. It is obtained by diaeolying in
alcohol the impure crystals of asarone as they are obtained by distilling the root with
water, predpitetinff by alcohol, and coUecung the small silky crystals whidi fioal
about in the liquid. Griiger, who obtained t^ substance at first, reaarded it as a
distinct body, but was afterwards disposed to regard it aa identical wiu asarone : the
difference in the melting point is, howeyer, too great to be accounted for by enor of
observation. Blanehet and Sell suppose it to Imb the solid part of aaonunHM], and
asarone a product of the decomposition of that oil.

A yolatile oil existing in small quantity (about -jj^) in the root
of Ajiarum europattmf and passing oyer, together with asarone, wnen the root isdistiUed
with water. It may be separated from the asarone by treating the oily portion of the
distillate with a small quantity of alcohol. Two layers then form, the upper bdng
an alcoholic solution of asarone, containing a little of the oil ; the lower, a solution of
small quantities of asarone and alcohol in the oil. On diBtilling this lower liquid orer
hydrate of lime, and leaving the distillate to stand for some time, the asarone sepa-
rates out» and the remaining oil may be dehydrated by cbloride of <*^l«"w» The

ASBESTOS — A8B0L1NE. 416

oQ IB jeOowiah ftud vMd, smellB like yalerian oil, has a aliaTp bnnimg taste, ia lighter
than irater, eptamglj aoluble in ▼atar, bat easily aohible in tuoohol, ether, and in oils
both fat and Tolatileu Blanche t and Sell (Ann. Ch. Pharm. -vi, 296) deduce from
tbeir aaal^rna (74*4 G, and 9'7 H) the fonnnla CH*0| vhich does not agree very
well vith it: the formnlA O^'H^O*, ia more in accordance with the analysis. As, how-
ever, the oil donbtlass still contained asarone, it is useless to attempt to determine ita
fijimnla exactly till farther experiments are made. It appears, howeyer, to contain
more carbon and hydrogen than asarone, which therefore may have been formed fiom
it by oxidation.

I or JUIBSBTUBa (&r/3c0Toi, indestractible.)— ^A mineralogical term
osed rather to denote a peculiar form assumed by several minerals, than to designate
BDj particular species. It is, in fact^ applied to seTeral varieties of amphibolic and
aagitic minerals, such as aetinolite, trenmite^ anthophyilite, &c which occur in long
capillaiTcrystals, placed side by side in a parallel position, thus producing a fibrous
mass. These conditions may be fulfilled in various degeees, and there are accordingly
Tarioos kinds of aabestoe. Those varietiee whose fibres are very delicately and rega*
lariy arranged, are called jZenSZs asbestos^ or amianth (a Greek term, siCTifying vnpo^
Uiti); the individual crystals are easily separated from each ouier, are very
-flexible and elastic, and have a white or greenish colour, with a fine silky lustre. A
single fibre of this mineral fusee readily into a white enamel ; but in the mass, it is
capable of resisting ordinary flame, so that when woven it inx>duces a fire-proof doth*.
^he meet beantifulspedmens are found in the Tarantaise in Savoy, and in Corsica,
where it ocean veir abundantly. It is also found near Bar^ in the Pyrenees, in
Daapbiny, and on the St Qothard ; at St Neveme in Cornwall ; at Portsoy in Scotland ;
in mica slate at Glenelg, Invemess^hire ; and near Durham. Those varieties in which
the czystals are coarser, with scarcely any fiexibility, are called ifommon asbestos.
There are also three other varieties, called mountain leather^ nunmtain eork^ and
mountain wbod^ wfaidi differ from common asbestos by the fibres interlacing each
other.

Common asbestos occurs in masses of fibres of a dull greeniiBh colour, and of a
somewhat pearly lustre. Fragments splintery. It is scarcely flexible, and much
denser than amiantiius. It is slightly unctuous to the touch. Specific gravity 2*7.
Foses with difficulty into a greyish-black scoria. It is more abundant than amianthus,
and is found usually in serpentine, as at Portsoy in the Isle of Anglesea, and at the
Lizard in ComwalL It was found in the limestone of Glentilt^ by I^. M*Culloch, in a
pasty stat^ but soon hardened by exposure to air.

Mofuntain Leather consists, not of parallel fibres Uke the preceding, but inter-
woven and interlaced so as to become tough. When in very tliin pieces, it is called
mpuntttin paper. Its colour is yellowish-white, and its touch meagre. It is found at
Wanloduieao, in Lanarkshire. Its specific gravily is uncertain.

MotmUun Cork, or Elastic Asbestos, is, l£e the preceding, of an interlaced fibrous
textuiv; opaque; has a meagre feel and appearance, not unlike common cork, and
like that substance is somewhat elastic. It floats on water. Its colours are, white, grey,
and yellowish-brown. It takes an impression from the nail ; is very tough ; cracks when
handled, and melts with difficulty before the blowpipe. Specific gravity from 0'68
to 0-99.

Mounttdn Wood. — ^Ligniform asbestos is usually massive, of a brown colour, and
has the aspect of wood. Internal lustre glimmering. Soft^ sectile, and tough ; opaque ;
feek meagre ; melts to a black slag. Specific gravity 2*0. It is found in the Tyrol ;
Danphiny ; and in Scotland, at Olentilt, Portsoy, and Kildrumie.

The ancients manufactured cloth out of the fibres of fiexible asbestos, for the pur-
pooe, it is supposed, of wrapping up the bodies of the dead when exposed on the
funeral pile. This doth has also been made in modem times, the chief artifice
seeming to consist in the admixture of fiax and a liberal use of oil, both which
sabstances are afterwards consumed by exposing the doth for a certain time to a
red heat Gloves are made of it for holding red-hot crucibles, &c. The cloth of
asbestos, when soiled, is restored to its primitive whiteness by heating in the fire.
Ignition impairs the fiexibility of asbestos in a slight degree. — XT.

See CoBAJLT, Eaatht.

A nitroji^enous substance contained, according toBraeonnot (Ann.
Ch. Phys. [2] xxxi. 87), m soot (iurfioXii), It is extracted by boiling the soot with
water, evaporating, redissolving in water, addinc hydrochloric add to the solution,
washing the pitchy predpitaite with cold water, ttien boiling it with water, filtering
after cooling; evaporating again, and treating with boilinff water tOl no deposit forms
on eooling: The liquid then yidds by evaporation a kind of varnish, partially soluble

4 16 ASCLEPIADIN — ASH.

in ftloohol ; and on treating the residne with ether and evajKirating, asbolinezemains in
the form of a yellow, very acrid, bitter, Tolatile oil, which ia lighter than water, buna
with flame, and vieidB an ammoniacal product hy distillation. Asboline diaaolTee in
nitric acid, yieldug picric and oxalic acids. Its aqneona eolation ia coloured deep red
by alkalis, forms an orange-coloured precipitate wiui acetate of lead, rednoea nitzate of
Bilyer, and is precipitated by infbsion of g^Jk.

ASCntSFIABZflT. A bitter emetic principle, contained in the Asdepioi tmiM-
toxicum. It is insoluble in water, alcohol, and alcoholic ether. It appears not to
contain nitrogen. (Fenelle, J. Pharm. [2] zL 565.)

ASCnbBVIOn. CPH'*0'. — ^When the white miUrp' juice of dadipias Wjfriaea is
heated, the albumin contained in it coagulates, and on treating the ooa^um with
ether, and eyaporating, asdepione is deposited in finely radiated or canliflower-like
groups of crystals. It is tasteless, inodorous, quite insoluble in water and alcohol, but
disscdyes readily in ether, less easily in oil of toipentine^ naphtha, and strong acetic
acid. It melts at 104° C, and then remains amoiphous. At a higher temperatore, it
decomposes, giying off the odour of burnt caoutchouc It is not attacked by atraiig
boiling potaw. (List, Ann. Ch. Pharm. Ixix. 125.)

ASK or OBOAVSO BOSIBS. When any part of an oreanised body,
yegetable or animal, is burnt with firee access of air, part of it is resolyed into yolatUe
compounds, chiefly water, carbonic anhydride, and fi^ nitrogen, while the other, and
generally the smaller portion, is left as incombustible residue or ash. This residDa
may contain the following elements : -^

Basic. Aeid.

Potassium Chlorine

Sodium Bromine

Calcium Iodine

Barium Phoaphoms (as phosphoric add)

Iron Sulphur (chiefly as sulphuric acid)

Magnesium Silicon (as silicic add)

Manganese Carbon (as carbonic add, and ocea-
Alnminium sionally as i^anogen).

Copper
Zinc
(Lead, nidLel, cobalt^ tin) ?

These substances are the so-called inorganic or mineral constitaents of the Toge-
table or animal structure ; they are essential to its existence, and are asaodated with
the organic matter in certain definite forms^ not necessarily the same as those xrideh.
they assume in the ash. It must be remembered, howeyer, that the distiikcCion
between the organic and inorganic dements of an organised body is by no means
absolute : for the carbon and oxygen, which are neyer absent horn the ash, bebng
essentially to the organic structure of the body. Perhaps the best distinction between
the organic and inorganic constituents of a plant or animal body is, that the fonner,
viz. the carbon, hydrogen, oxygen, and nitrogen, are deriyed, in great part at leasts
from the air, whereas the latter are deriyed exdusiyely from the soiL

The inorganic constituents aboye enumerated are not all of equal importance to the
existence of organised structures, or of equally frequent occnrrence. Potaadinn,
sodium, caldum, ma^esium, and iron, associated with phosphoric add, sulphuric add,
carbonic add, silicic add, and chlorine, are almost always present, in greater or
lesser quantity, in the ashes of organised bodies, whether yegetable or animal;
fluoride of caldum, in yeiy small quantity, appears also to be an almost inyaziahle con-
stituent; and manganese, also in small quantity, is of firequent occnrxenee; the other
elements are of rare or doubtful occurrence.

The mineral constituents of plants and animals yary greatly in amount, as wcH as
in composition. In bone, the inorganic matter constitutes from |^ to } of the entire
mass, the amount in indiyidual cases depending upon the age and spedes of the
animal; in the higher classes of animals, the bone-ash consists mainly of phosphate
of calcium, with a smaller quantity of carbonate; in the lower daases, the propor-
tions of these constituents are reyersed. Phosphate of caldum occurs also in the
ashes of the albuminouB prineiplea, both of plants and animals, and is espedally abon-
dant in the seeds of c^eal and leguminous plants; phosphate of magnesium
is abundant in the ash of wheat-grain. The alkaline chlorides are yeiy
widdy diffused throughout the bodies of plants and animals; chloride of sodium
is inyariably present in the fluids of the animal body and in the juices of plants.
Alkaline carbonates are always present in the blood, and appear to be eoseptial
to the solution of the albuminous principle Carbonate of potassium fimns the

ASH OF ORGANIC BODIES: 417

greater part of wood-ash. Silica is scarcelj ever absent from the ashes of organised
bodies. The ashes of equtseiaeeaus plants contain 97 per cent of silica. The hard
external sheathing of the stems of grasses consists of silicate of potassium. The
shields of the lowest dasses of animaw, infusoria^ &;&, consist mainly of silica, which
is so thickly deposited in their organs, that neither decomposition nor incineration can
destroy their form : hence it is that deposits of infusoria are so often discovered. In
the tisanes and juices of the higher classes of animals, silica occurs only as an inci-
dental constituent, though it is seldom altogether absent. According to Gorup-
Besanex (Ann. Gh. Phann. Ixri. 342), it forms an integral constituent S feathers and
of Aotr.

SnlpliuT occurs to the amount of about 1 per cent, in all the albuminoidal sub-
stances, and is conrerted during incineration into sulphuric acid, which is found in
the aah as alkaline sulphate, sometimes however more or less reduced to sulphide by
th.e action of the carbon at a hi^h temperature. The juices of the animal body and of
plants also contain small quantities of alkaline sulphates and sulphate of calcium.

Iron 18 alwa^ present in vegetable and animal tissues and fluids, and is found in
the aah aa sesqmazide, either free or as basic phosphate.

Alumina has been found in considerable quantity in the juice of plants which ex-
hibit an acid neaction, e.g, in Lycopodium chammcyparissuSf L. clavatum, and L. den-
ttadatum (Salm-Horstmar, J. pr. Chem. xL 302; Aderholdt, Ann. Ch. Pharm.
l^"'^^ 111; Solms-Lanbach, ibid. c. 297). In most other plants, alumina is alto-
gether absent, any small quantities that may be found in the ash, senerally arising
fivm impurity in the reagents, especially in the caustic potash or soda^ or from want
of due care in cleansing the leaves, roots, or other parts under examination, fzom
adhering poiticles of soiL

The ^er motab above-mentioned as occasional constituents of ashes, occur only
in very small quantity, their presence being mostly, perhaps, due to some peculiarity
in the nutrition of the plant or animal in wich they are found. A peculiar kind of
violet {Viola calaminaris) with yellow flowers, was found by A. Braun (Pogg. Ann.
xrii 175) to contain zinc, which metal was likewise found in the soil, its presence
dcmbtless determining the production of the peculiar variety of the plant. The ash of
the blue blood of Idmvlus cydops was found by Genth (Pogg. Ann. xcv. 60) to contain
0'08 to 0*33 per cent, of oxide of copper. The occurrence of titanic acid in
pUmt-aahes is mentioned by Stadeler (Wohler's prakt. Chem. Uebungen, 1853
p. 173), of baryta by Scheele ^in 1788), and more recently by Eckard (Ann. Ch.
Pharm. & 294), and by Forchnammer (Pogg. Ann. xcv. 60; Jahresber d. Chem.
1869, p. 987). On the oocuirence of copper and other metals in plant-ashes, see also
JTahreeber. 1847—8, p. 874; 1849, p. 430; 1852, p. 702; 1853, p. 604.

Ab the mineral constituents of pkmts are all derived from the soil and vary greatly
bcrtli in amount and in composition, it will be easily understood that the examina-
tion of plant-ashes is of great importance with reference to agriculture. A plant will
not grow on soil deficient in the mineral substances whic^ it requires; if phos-
phonc acid is deficient, wheat and other cereal grasses cannot form their seed in its
normal amount; if there is a deficiency of silica, the straw will be weak. Some
plants require abundance of alkali, others of lime, &c The examination of the ash
showB what particular mineral substances the plant requires, and consequently what
substances must be supplied to it artificially in the form of manure, if they are not
already contained in the soil.

We now proceed to describe the preparation and analysis of ashes.

Preparation of the Ash, — The substance to be incinerated must in the first
p]ai» be earefttOy freed from extraneous matter. Herbs, roots, and barks, which are
especiaUy liable to be contaminated with adhering mould, day, or sand, must first
be deancd from the grosser impurities by scraping, or otherwise, and then washed
with a sightly moistened sponge to remove the fine dust; washing with large quanti-
ties of water is objectionable, as it may remove some of the soluble salts. Seeds are
best cleaned by pourins distilled water upon them in a glass jar, stirring for a little
while with a rod, and uen pouring the whole on a coarse sieve, which allows the fine
dust to run through, but retains the seeds. After repeating this treatment two or three
times, the seeds may be further cleansed by rubbmg them between a linen cloth.
Jiaim^l substances are less liable to contamination with mechanical impurities;
their incineration is often &cilitated by exhausting them with water, and incinerate
ing separately the aqueous extract and the residue. The quanti^ of material
incinerated should be such as to jrield from 4 to 6 grammes of ash. Gf seeds, roots, barks,
and leaves, which are for the most part rich in mineral constituents, from 100 to 200
grammes of the dried substance is generally sufiident ; of wood, two or three times
that quantity must be taken ; of animal substances containing a largo amount of

You L E E

418 ASH OF ORGANIC BODIES.

water, it is often necessary to incinerate a mnch larger quantity. The Babstanee dunM,
preyious to incineration, be carefully dried and somewhat comminnted; seeds, hswever,
if not very large, are best incinerated without comminution.

The incineration must be conducted with great care, as the oonstitntioii of the aah
is often materially affected by the manner in which it is peifonned. The ehlondei ol
potassium and sodium, thougn fixed at comparatiTely low degrees of heat, yolstiliBe pn>
oeptibly at the high temperature sometimes attaanea durins the indnentuni, espeeuUy
in a current of air ; this is still further the case with iodic^ Moreoyer, by the joint
action of silica and charcoal, phosphates may be decomposed and phomhonu Tobd'
lised ; sulphates also reduced to sulphides, or sulphuric add driyen off. And eren
when no actual loss takes place, different modes of incineration may giye rise to con-
siderable differences in the composition of the ash. Carbonates in an ash genenUy
result from the combustion of salta of organic acids f^risting in the substanoe boned;
they may, howeyer, be introduced in other ways. If tribasic phosphate of aodhm be
ignited in presence of a large quantity of organic matter, sugar, for example, till the
organic matter is chaired, and the mass be then liziyiated with water, a solotion of
carbonate of sodium is obtained, and the residue, after the charcoal has been com-
pletely burned away, consists of pyrophosphate of sodium, the caibonie add pEodnoed
by the combustion of the organic matter haying decomposed the tribadc {dioephate,
taken away 1 at. of the base, and conyerted it into carbonate. If, on the other
hand, the mass be at once completely incinerated without liziyiation of the diaitoal,
nothing but tribasic phosphate will be obtained. In all cases then, in idiicfa the
arrangement of the mineral constituenta of an organised structure is to be infiened from
the composition of the ash, ^reat care must be taken to guard against or alknr for ugr
such modifications as that just noticed. In the examination of plant-ashes toe agn-
cultural puiposies, such questions are indeed of minor importance, the chief object of
the inyestigation being to determine the ultimate constituents of the ash; bat is
physiologic^ inquiries, the actual arrangement of the mineral oonstLtuents in the liTisg
structure is often a point of great importance.

The difficulty of incinerating an organic substance is greatly increased when the adi
is eaaily fiisible, the decompositions just considered being then most likely to oocnr.
Leayes, herbaceous stems, roots, bark, &c., which diiefly contain infusible nlta of the
alkaline earths, are comparatiyely easy to bum ; but seeds, and many animal sub-
stances, such as dned blood, which contain large quantities of alkaline salts, are Tezy
troublesome, and require great care in regulating the temperature.

The method of incineration originally practued, especially for the prepantson of
plant-ashes, consisted in burning the dried substance in a Cornish or Hessian c^liribi^
laid obliquely in the fire, and kept at a moderate red heat. The carbon then huu
away witii greater fieicility, the looser the texture of the chaired mass, and tiie leas its
position and form are altered by moyement and starring. The objectioos to this
method are that it often giyes incorrect results regarding the amount of phosphone
acid, carbonic add, and chlorine, inasmuch as chlorides are decomposed by the action
of add phosphates in presence of water, and at yeir high temperatures, pho^^horas may
be yolatilised by the action of charcoal on add pnoephates. Extraneous matters nay
also be introduced into the ash by the action of phosphates in a state of fnsion oo the
crucible.

A much better method is that recommended by Erdmann, whidi oonnsts in in-
cinerating the plant or animal substance in a muffle built into the month of a i1I^
nace in such a manner that the heat may play upon it chiefly from the top.
The indneration goes on most fayourably at a distance of 3 or 4 inches from the
iVont aperture of the muffle, and at a low red heat not yisible by dayh'gfat At
this temperature, there is no danger dther of the yolatilisation of dilorides or of the
fiidon of phosphates. If the muffle be kept loosely closed by a day stopper, suiBaent
air will enter to produce, in the course of twelve hours, a quantity of ash free fro*"
charcoal suffident for an analysis. A conyenient mode of proceedmg is first to ehsr
the substance in a platinum or porcelain dish, and then heat the charred residne a
the muffle in the manner just described ; the charcoal then bums away with slight
incandescence. The ash may afterwards be weighed in the dish.

Messrs. Lawes and Gilbert use cast-iron muffles 18 inches long, 3| inches bi^
and 6 inches wide at the bottom. The muffle, which has a flange at the fore peit,
fits exactly into an orifice in a cast-iron furnace firont ; and a 1| inch pipe proceeding
from the farther end of the muffle, passes through the cast-iron furnace bade, and
seryes to carry away the eyolyed gases. The muffle rests on a brick in the fiarnace, to
lessen bottom heat and thus prevent fusion, the fuel being heaped up at the sides and
top, chiefly the latter. The substance is burnt in laige platinum sheets or dishes, the
latter 10 inches long, 4 to 5 inches wide, and 1} inch deep. By this arrangement, the
aecess of ash from the fire is entirely avoided ; the ash is burnt by surface^ not hy

ASH OF ORGANIC BODIES. 419

bofttom heat ; Hie dranght of air is free ; and the incineration may be aceompliBhed at
a Toy low temperatore.*

Thu is by far the beet mode of incineration yet deyised; neyertheleas it is occa-
skmaUT att^ded with slight loss of eolphur, pbosphonis, chlorine, iodine, &c To ob-
riate these Iobms, it has been proposed to mix the substance to be incinerated with lime,
baryta^ or other strong bases capable of retaining the acids. Wackenroder adds for
this pnnpoae, acetate or carbonate of calcium, or quick lime; Strecker proposes to
moisten the dried and chaired substance with such a quantity of baiyta-water, that the
ash, after incineration, may contain about half its weight of baryta. The moistened
charcoal ia then dried and burnt in the muffle at as low a temperature as possible. To
sKtbstanees which produce ashes containing much carbonic and silicic acids, Way and
Ogston , add far the same purpose, nitrate of barium; Slater adds peroxide of barium ;
Yerdeil, nitrate of ammonium; and Will, mercuric oxide; but ul these admixtures
are attended with peculiar inconyeniences, which stand in the way of their general
application.

A. Koae adds a weighed quantity of carbonate of sodium, chars the substance in a
cmdble, and bums away the charcoal by directing a stream of oxygen upon it through
■n apertnre in the lid. Tlda method ei&cts a complete and rapid combustion of the
eharooal, bat the high temperature produced often causes the ash to fuse, and then the
cmciUe is attacked. Crudblee of stone-ware (Steingut) withstand the action better
than those of porcelain.

[Pbrthemethodsof Mitscherlich and Hlasiwetz, seeHandw.d. Chem. 2^ Aufl.
ii 352 ; for the latter also, Ann. Ch. Pharm. xcyu. 244.]

Analysis of the Ash, — Of the yarious methods which haye been giyen for the
analysis of ashes, the simplest and most generally applicable is that of Professor
Will (Handw. d. Chem. 2** Aufl. ii. 361 ; Conington's Handbook of Chemical Analysis,
p. 226). The ash prepared in the muffle at the lowest possible temperature, is tritu-
rated to a uniform powder, and preseryed in a stoppered bottle. One portion of it is
used to determine the carbonic acid by one of the methods giyen under At.kat.titbtby,
p. 119. A second is treated with dilute nitric acid, and the filtrate is used for deter-
mining the chlorine by precipitation with nitrate of silyer ; while a third portion ^4 or 6
grammes) is used for determining the silica and the other constituents. For this last
purpose, the ash is treated with hydrochloric acid ; the silica separated by complete
erapoiBation to dryness, and digestion of the residue with water containmg hydro-
chloric acid (see Sojca.); and the quantity of the filtrate, together with the washings, is
determined, either by weight or by measure.

In one portion of this filtrate, of known weight or yolume, the sulphuric acid is
detennined by pecipitation with chloride of barium; in a second, the lune, magnesia,
aeaquiojjde of iron (alumina, if present), and the phosphoric acid ; in a thi^, the
■ikalis.

Lime, Magnesia, Ferric Oxide, Phosphoric Acid, — ^I^ as in the ashes of seeds and of
many animal substances, all the bases, or the greater part of them, are present as
pho^hates, the liquid is first supersaturated with ammonia (or mixed with acetate of
sodium), then with acetic acid, and the undissolyed ferric phosphate, Fe^O'.cP*0^ is
collected and wei^ied (together with phosphate of aluminium, if present, which may
afterwards be separated by potash). The lime is next precipitated by oxalic acid,
then part of the phosphoric acid and all the magnesia by ammonia, and the rest of the
pbo^horic acid by a magnesium-salt. In ashes containing a smaller proportion of
phosphoric acid, part or the whole of the magnesia remains in solution after this treat<-
ment. This portion is determined by precipitation with phosphate of sodium, or (if
the mtiate is to be afterwards used for the determination of the alkalis) with phosphate
of ammoninm. If manganese is likewise present (as a manganous salt), the ferric
pho^hate is first precipitated as aboye ; the liquid filtered &om the precipitate is
mixed with a known yolume of a standard solution of ferric chloride made as neutral
as possible ; the whole is heated to boiling ; the precipitate thoroughly washed with
hot water and dried ; and from its weight that of the (anhydrous) phosphoric acid is
ioftrnd by deducting the weight of the ferric oxide added t ; to this quantity of phos-
phoric arid, must be added that which was preyiously determined as ferric phosphate
(and phosphate of aluminum). In the filtrate, which contains manganese, calcium,
sod magnesium, these metals are determined by the usual methods, the manganese
being precipitated as peroxide by hypodilorite of sodium, the precipitate collected after
tw«nty-ibar hours, then ignited or weighed as manganoso-mangamc oxide (Mn'O').^

AlkaUs, — The ash, dissolyed in hydrochloric add, not in great excess, is mixed with

• Tor the abore dMcrlption, the BiUtor ii Indebted to the kindness of Dr. Gilbert. ... .

t Tbe amoant of phoephoric add In this prectpiUte might be determined directW by dissolving in
hydrochloric acid, adding sufficient tartaric acid to prevent precipitation of Iron and alumina by aliuaU,-
ibcp addhij excaa of arnmooia, and rtwipitating by a maguesiuro-falt.

BB 2

420 ASH; VOLCANIC.

oxalic acid, then with excess of ammonia, and if magnesia is BtQl in solution, vith
phosphate of ammonium.* The precipitate is washed with ammoniacal water; the
flltrate is evaporated a little to expel the excess of ammonia, and mixed while still
hot with acetate of lead ; the liquid is again filtered, and the excess of lead remored
by ammonia and carbonate of ammonium ; the filtrate from this precipitate, together
with wash-water, is evaporated, with addition of sal-ammoniac; and tke ammoniacal
salts are expelled bj gentle ignition. The residue^ which contains nothing bat the
chlorides of potassitun and sodium, is then weighed, and the relatire (quantities of the
two chlorides are determined, either by precipitating the potassium with dichloride of
platinum, or determining the amount of chlorine by precipitation with nitnte of
silyer. (See Aitaltsis, Btdisbgt, p. 220.)

Knop and Arendt (Ohem. Gentralbl. 1857, 169), determine the phosphoric acid in
ashes by adding uranie acetate to the solution, acidulated with acetic acid as abore,
whereby a precipitate of ammonio-nranic phosphate is produced, which, when ignited
with addition of a few drops of nitric acid, leaves uranie phosphate, containing
2Ur*0'.PK)*. (For the details of the method, see Phosfhqrig Aom, under F&os-

FHOBUS.)

For other methods of ash-analysis, see Fresenius and Will, Ann. CKl Fhann. I
363; Erdmann, J. pr. Chem. xxxviii. 20; H. Rose, Pogg. Ann. Ittt. 94, and
Handb. d. Analyt. Chem. ii. 766 ; Mitscherlich, J. pr. Chem. xxxv. 281 ; Waeken-
roder. Arch. Pharm. [2] liii 1 ; Stadeler, Prakt Uebungen in der Chem. AnaL tob
Wohler, 1863, 172 ; Wittstein, Pharm. Centralbl. 1863, 761. Also for a description
of all these methods, Handw. d. Chem. 2'* Aufl. iL 353.

For the composition of the ash of individual plants, see the names of the plants in
this dictionary. Extensive tables of the composition of plant-ashes are given in the
first five volumes of Liebig and Kopp's Jahresbericht der Chemie^ 1847 to 1852. The
new edition of Ure's Dictionary ofArte^ Manufaeturea^ and Mines (i. 212), also con-
tains a table showing the average composition of the ash of some of the most nselol
agricultural plants.

ASBf VOZKSAVZO. This name is applied to the polvemlent portion of the
matter thrown out by volcanos. The ash emitted by different volcanos, by the same
volcano at different timea, and even at different stages of the same eruption, exhihia
great differences of structure and composition. It is sometimes dail^-coloured or even
black, and composed of earthy or soft particles, sometimes grey or white, and findy
divided. In the eruption of Vesuvius, a.i>. 79, which overwhelmed Pompeii and
Herculaneum, the ash was so fine and diy that it took exact casts of objects buied
in it It is this finely divided matter to which the term ash is especially applied,
the coarser varieties being generally denominated volcanic sana; it sometimes
rises to considerable heights, and is then carried by the wind to great distanres. In
the eruption of Coseguina, on the Bay of Conchagua, in Guatemala (1836), some of the
ash fell at Kingston in Jamaica, at a distance of 700 miles.

Volcanic ash, when examined by the miscroscope, appears to be oomposed of frag-
ments of lava, slae, mica, felspar, magnetic iron ore, augite, pumice, olivine, &e: It
is therefore a mechanical mixture of minerals and rocks abraded by trituration against
each other. In the ash thrown out by Vesuvius on the 22nd of October 1822,
Vauquelin found 28 pts. silica, 8*0 alumina, 18 gypsum, 20*88 iron pyrites, 2'6 lime;
and 1 carbon, together with 41*42 pta. sulphate of copper, sulphate of ammonium,
chlorides, and sulphur. In the ash emitted from the crater of the Soufriire in Guadsp
loupe, in 1797, Dufrenoy (Ann. Ch. Phys. [2] Ixvii. 251) found 2 per cent, of alum,
potash, and gypsum, 8*84 water, 32*61 pts. of matter attacked by acids (which he
regarded as labrador), and 56*23 pts. not attacked by acids (regarded as glassy fel-
spar). In the ash thrown out by the same crater in the year 1836, IHifr^noy found
60*88 pts. of matter insoluble in acids, 33*72 pts. soluble in acids, 6*93 water and
0*62 sulphur (loss 1*85 per cent)

The following table contains the results of a few more recent analyses : a, 6, aiA
from the above-mentioned eruption of Coseguina (Duf r ^noy and £lie de Beaumont,
Ann. Ch. Phys. [2] Ixviii. 266) ; this ash contained 18 pts. of matter decomposiblf^
by hydrochloric acid (a), and 82 pts. unattacked by that add (6). c, Aah from
Gunnung-Gurtur, in Java; eruption of January 4th, 1843 (Mayer, Leonhard, and
Bronn's Jahrb. d. Miner. 1853, 463). d, Ash from the same volcano ; eruption of
November 26th, 1843. Of this ash, water dissolved 0*3 per cent, eonsistbg of lime
and magnesia-salta (Schweitzer, J. pr. Chem. Lev. 194). f. So-called ferrie ashes,
and/ so-called /<?rroi« aah^s from Etna (Sartorius von Waltershausen, "Vul-
canishe Gesteine," Gottingen, 1853, 172). g. Ash from the eruption of Heda in 1846
(Genth, ibid, 176).

* For other methods of separating magnesia ft*om the alkalis, see MAOKlsnni.

ffifica • •
Alumina
Ferric oxide .
Fenous oxide
lime
Kagnesia
Soda
Potaah .
Water and Iors

ASPARAGINE. 421

a h e d e f g

61-7 64-3 34-2 61-6 487 61-3 66-9

16-2 21-1 87-6 21-9 17*9 18-4 142

130 — 18-2 — 12-7 — —

— — 6-7 10-8 — 11-7 13-9
11-1 1-4 0-7 9*3 6-6 7-6 6-2

— 0*7 — 3-3 2-5 4-3 40
6-2 9-6 -— 2-9 4-6 4*6 23

— — — 0-6 2*0 1-6 2-6
2-8 3-4 10 0-6 6*6 05

Matter soluble in water — c — 1*7 0*3 — 2*7

lOO'O 100-6 1000 101-2 101-4 102-6 100-1

C*H«N»0», or C»B*2^a', Mtheine, Asparamide. (Gm. x.
239.) — ^This substance was discoyered in 1805 bj Yanqnelin and Bobiqnet (Ann.
Chim. Irii. 88). It exists ready formed in many plants, yiz. in common asparagas
{Asparagus qjffieinaUs)^ in the marsh-mallow (Alihaaa off.), in com£rey {Syfnphytum
off.% in potatoes, in diestnuts, in the leayes of the deadly nightshade {Atropa JBeHa"
donna\ in liqnorice-root, in the root of Robinia pseudacacia, in Conwularia majalis,
and C. muhijhra^ in the milky jnice of the lettuce, in the tubers of tJie dahlia, and
in the young shoots of yetches, ^eas, beans, and seyeral other leguminous plants grown
in the dark. According to Piria (Ann. Ch. Phjs. [3] xxii. 160), the young shoots of
these plants, when formed in the light, contain just as much asparagine as when they
are grown in the dark ; but the asparagine disappears as the plant arriyes at the flower-
ing stage. On &e other hand, Dessaignes and Chautard (J. Pharm. [3] xiii.
245), and likewise Pasteur (Ann. Ch. Phys. [3], Ixxxi. 70), find ^at yetches growing
in light are free from asparagine.

Preparathn, — The juice obtained from the young shoots of asparagus, filtered and
eraporated to a syrup, deposits after standing for some days, crystafs of asparagine,
which may be purified by recrystallisation from water. As the mucus of the plant
impedes the crystallisation, it is best to leaye the Shoots to ferment for a few days in
a warm place, and then bruise and press them, with addition of water ; by this treat-
ment the mucus is decomposed. In a similar manner, asparagine may be obtained
from mazBh-mallow roots, and isam the young shoots of yetches, &c grown in the
dark. To obtain asparagine from Uquorice-root, the root is cut into pieces and ex-
hausted with water; the liquid boil^ to precipitate the albumin, then mixed with
acetic add to separate the ^ycyrrhizin contained in the root^ and afterwards with
acetate of lead, which throws down phosphate and malate of lead, together with brown
oolooring matter; and the excess of lead is remoyed by sulphydric acid. The
filtered liquid eyaporated to a small bulk, deposits crystals of asparagine after a few
days.

Asparagine forms hard brittle crystals, 0^H^NK)'.K'O, belonging to the trimetric

system. The ordinary form is a right rhombic prism, ooP , oP . ml* oo . oo j^ oo, with

ihB hemihedral faces \, Inclination of the &ces, ooP : ooP » 129^ 37'; ^ : oP «

lie<'-67'; mt CO : oP « 120O 46'. Specific grayity 1-519 at 14° C. The crystals are
inodorous, haye but a alight taste, and are permanent in the air. They giye off water
of crystallisation at 100^ C. They dissolye in 11 pts. of cold, and 4*44 pts. of boiling
water ; the solution has a slight acid reaction. Asparagine dissolyes also in acids and
in alkalis. It is insoluble in cold absolute alcohol, and nearly insoluble in that liquid
at higher temperatures ; insoluble also in ether and in oils, whether fat or yolatile.

Asparagine dissolyed in water and in alkalis, defiects the plane of polarisation of a
zay of li^t to the left ; but when dissolyed in acids, it deflects the phine of polarisa-
tion to the right. The specific rotatory power of an acid solution is + 35°, and of an
ammoniacal solution, —11° 18'.

Asparagine heated with strong acids or alkalis, is resolyed into aspartic add and
ammonia:

C*H»N»0» + H*0 « C^H'NO* + NH».

The crystals subjected to dry distillation also giye off ammonia, and leaye aspartic acid.
Asparagine dissolyed in cold nitric acid, yields aspartic add and nitrate of ammonium,
but when subjected to the action of nitrous acid, as when nitric oxide gas is passed
through a solution of asparagine in pure and moderately strong nitric acid, it is con-
Terted into malic acid, with eyolution of nitrogen :

C«HWO« + N»0» - C*H«0» + N« + HH)

BB 3

422

ASPARAGINE— ASPABHC ACID.

The solution of pure aepangine-dystals may be kept unaltered ; but if the oyvtals
are coloured, their solution soon passes into a state of fermentation, and the vhole of
the asparagine is oonyerted into succinate of ammonium :

The hydrogen is deriyed from the fermenting matter. A solution of pezfecCly pan
asparagine experiences the same change when mixed with a small quantity of tlifl
juice expressed from the young shoots of vetches (Piria). Asparagine fermeats abo
under the influence of casein, and is oonyerted first into aspartate of aounonium, aft»*
wards into succinate.

Asparagine forms definite compounds with acids. The hydrocklorate, C^H*NK)'.HG3,
is obtained in large crystals either by dissolyine 1 at. asparagine in 1 at hydroehlorie
acid, evaporating at a gentle heat, and adding ucohol ; or by passing dry hydroefakne
acid gas oyer finely pounded crystals of asparagine^ exposing the lesulting oompoond
to the air till it no longer gives off add vapours, then diflw>lving in hot water, nd
leaving the solution to cooL

Asparagine also forms salts in which 1 at of its hydroeen is replaeed by a metal;
thus the copper-salt is C*H^CuNO'. These salts are obtamed by mixing a aohitioD oif
asparagine with the corresponding oxides. Asparagine also unites with chloride of
mercury and nitrate of silver.

Asparagine has the same composition as nialamide, 17'(H^C^£[K)'), and itBO(mT«nio]i
into malic acid by the action of nitrous acid, suggests the idea that it may be leelly
the amide of that acid. According to Demondesir, however (Compt reod. xsxiii
227), and Pasteur (Ann. Oh. Phys. [3] xxxriii 437) the amide obtained by the
action of ammonia on malic ether, di&iB frx>m asparagine in crystalline form ud in
other properties.

An old name of the variety of apatite which has the green
colour of asparagos.

JkMPJkMAUJtU oyjffXOlM ft TiTil ■ The ashes of wild and coltiyated aroaiagni,
and of the young heads of the cultivated plant, have been analysed by T. J. Hera*
path (Chem. Soc. Qu. J. ii. 9). 100 parts of the fresh wild plant yielded 2*42 ]^ of
ash; 100 pts. of same dried, 6*07 per cent ash. The cultivated plant yielded in the
fresh state 1*63, and in the dry state 6*07 per cent ash. The young heads in a state
fit for the table gave 0*81 per cent and 11 '24 per cent ash. The oonstitaenti of
the several aahes are as follows : —

Soluble in water:

^ j r Carbonic acid
•g I < Sulphuric acid
^■S (phosphoric acid

Potaah

Soda

Chloride of sodium

Chloride of potassium
Insoluble:

Carbonate of calcium

Carbonate of magnesium

Basic ^phosphate of calcium .

Basic ferric c-phosphate .

SiHca

Sulphate of calcium

Baaic phosphate of magnesium

Soluble in water (per cent) • ^1*67
Insoluble

Wild.

Cultfvmted.

TouDg Heads

4-86

14-27

4*01

777
trace

3 66

210 ;

81-08

16-81
2-72

32-74

82-68

20-61

trace
1306

10*06

21*48

14*61

6-96

2-62

21-67

16*21

14-06

1-70

0-46

0-21

0-86

2-97

100

trace

99-94

99*98

100-00

61-67

67*64

7*78

48-27

42-34

22-22

Syn. with Aspabaoikb.

Syn. with Ahsabtic Acid.

C<H»NO*, or C^WNO'. (Plisson, Ann. Ch. Phys. xxxr. 175,
xL 303.— Plisson andO. Henry, ibid. xlv. 316.~Boutron-ChautardandPeloaze,
ibid. lii. 90.— Liebig, Pogg. xxxi 232, Ann. Ch. Pharm. xxvi 126, 161— Pirii,
Ann. Ch. Phys. [3] xxii. 160. — Dessaignes, Compt rend. •«Tr 329; xxxL 342;
Ann. Ch. Phium. IzxxiiL 83. — Pasteur, Ann. Ch. Phys. [3] xxxiv. 30; Ann. C%.

ASPARTIC ACID. 423

Fhazm. Izxzii 324.— Gm. x. 230 ; Gerh. 1 812.)— This add, vhich is isomeric, if not

•^^ ' \ is obtained either bj the decomposi-

tioii of asparagine, chiefly under the inflaenoe of acids or alkalis, or by the action of
heat on the acid malate, maleate, or fomarate of ammonium. The acids obtained by
these two processes are identical in composition, but differ in their relations to pola-
rised light, the former being optically active, the latter inactive.

To prepare aetive asp ar tic aeid, asparagine is boiled: 1. With water and oxide
of lead, aa long as ammonia continues to escape, the water being replaced as it
erapontteB : the resulting aspartate of lead, after being purified by boiling with
water and alcohol, is decomposed by snlphydric acid, and the filtered solution is
erapoiated till it oystallises (PI is son). — 2. With banrta-water, the aspartate of
banum being decomposed bysulphuric acid (Boutron and f elouze). — 3. With potash,
the liquid being afterwards evaporated to dryness with excess of hydrochloric acid, and
the ddoride of potassium dissolved out by water, which leaves the aspartic acid imdis-
solved and perfectly free from potash (Lie big). — i. With hydrochloric acid, for three
houzs^ the solution being then evaporated to dryness, and the residual chloride of
ammoninm and hydochlorate of aspartic acid dissolved in a small quantity of water
and half neutralised with ammonia; the liquid on cooling deposits a considerable
quantity of aspartic add. (Be s s aign es.)

Aetire aq^mrtic add crystallises in very small thin, shining, rectangular plates, trun-
cated at the angles; they belong to the trimetric system. Specific gravity 1*6613
at 12*6^ G. It is much less soluble in water than asparagine, 1 pt. of it re-
quiring 364 pts. of cold water to dissolve it. In boiling water it dissolves more
readily, but is nearly insoluble in alcohol It dissolves readily in alkalis, and the
solutions turn the plsjie of polarisation of a luminous ray to the left It is also easily
soluble in the stronger adds; and the solutions thus formed turn the plane of polan-
aation to the right The specific rotatory power of the solution in hydrochloric add
28 + 27^-86', (Pasteur.) ^ '

Inactive Aspartic Acid is obtained by heating add malate of amtnonium to
200^ C; boiling tne residue for some hours with hydrochloric acid ; dissolving the hydro-
ehlorate of aspartic add, which crystallises from the liquid on cooling, in hot water, and
half saturating the solution with ammonia. Inactive aspartic add then separates in
small crystals, belonging to the monodinic systeuL Ordinary Combination ooP. oP.
[P od]. Inclination of the faces, ooP : ooP in the plane of the oblique diagonal and
the prindpal axis » 128<' 28' ; oP : ooP •» 91<' 30'; [Poo ] : oP « 131^ 26'. The crystals
are grouped in stars, and sometimes take a lenticular fonn. Spedfic gravity 1*6632 at
12' 6^ Cu The inactive add is more soluble in water than the active add, 1 part of it
dissolving in 208 pts. of water at 13*5® G. It dissolves very easily in hy<uochloric
and in nitric add. The solutions have no action on polarised light (Dessaignes,
Pasteur.)

Aspartic add is decomposed by heat gi'ring off ammonia and a faint empyreumatic
odour, like that evolved m the destructive distillation of animal substances. It is not
acted upon by boiling with hydrochloric add or with dilute sulphuric acid, but when
heated with strong sulphuric add, it decomposes, and suli>hurous add is given off It is
not decomposed by pure nitric add, but if nitrous acid is also present as when nitric
oxide gas is passed ttirouffh a solution of aspartic add or nitric add, the aspartic acid
is converted into malic acid, with evolution of nitrogen gas :

2C^H'N0* + N«0» « 2C*H«0» + N* + H*0

1 — — ' ^— • — '

Aipartic Malic

acid. add.

Comftmitds of Aspartic Acid with Adds, — ^Both the active and inactive varieties of
aspartic acid dissolve in the stronger adds, forming definite oompoimds, which by
evaporation over the water-bath, or better by spontaneous evaporation, are obtained in
erystsJs. The compounds are active or inactive to polarised light according as they
aie obtained from the active or inactive add.

The active hydrochlcratSy G^^O^GIH, forms crystals belonging to the trimetric
system; they are prisms with angles of about 90°, very much truncated on two
opposite lateral edges, and terminated by faces inclined at an aujgle of about 115^, and
bekmging to an irregular tetrahedron. The crystals deliquesce in the*air, the aspartic
add being set free. They are decomposed by solution in water, but the addition of a
few drops of hydrochloric add prevents the decomposition. Specific rotatory power
of the solution + 24*4^. The crystals are decomposed by heat giving off water and
hydrochloric add, and leaving fiunarimide. The crystals of the ina^ve hydroehlo'
rmte belong to the monodinic system, and differ altogether in appearance from those

SB 4

424 ASPARTIC ACID.

of the actiTe compound. Ordinary combination oo P . ooP m . — F . oP . + mP op .
Inclination of the faces oP : ooP oo = 119^^ 46' ; » P od : » P » 123«. ThecrysUls
are nearly unalterable in the air, only in smnmer losing their lustre and transparenej,
and becoming milk-white on the surface. They decompose when diseolTed in mter,
but the inactive acid being more soluble than the active add, is not pieeipitated; if^
however, alcohol be added, an abundant precipitation takes place. The uactiTe hy-
drochlorate is decomposed by heat like the active salt.

The su^hate, C^H'NO'.SO^H', is obtained bv gradually addins as^aitie acidtoatrong
sulphuric acid heated to 6(P or 60° C. in a wide glass tuoe, and Teaving the tube dowd
for a few days ; it then separates in large agglomerated prisma, which are lifhter than
the mother-liquor (Dessaignes). TIm nitrate is obtained, like the hydrooilocate, in
beautiful crystals.

Asp^BTATBS. — Aspartic acid is monobasic, the formula of its normal aalta bdng
C^H*MNO\ It likewise forms basic salts, the composition of which u notveiydeaiiy
made out. The aspartates of the alkali-metali are soluble, and taste like broUi. The
active and inactive aspartates agree in composition, and in most of their properties,
differing only in solubility, crystalline form, and relation to polarised light

The ammonium Andpotassium salts are very soluble and difficult to ayitallifle.

The sodium-saltSj C*H'NaNO^H*0, are obtained by neutralising the add vith
caustic soda or its carbonate, and leaving the solutions to evaporate slowly; thej
are perfectly neutral The active salt crystallises in prismatic needles belonging to
the right prismatic system, and terminated by faces of a tetrahedron inclined to one
another at about 106°. The four faces of this tetrahedron are either present alone, or
are much more developed than those of the opposite tetrahedron, which, if eqnallj
developed with the former, would constitute a rhombic pyramid ; 1 port of this ailt
dissoTves in 1*12 pts. of water at 12*2 0. The specific rotatory power of the aolntioa
is — 2° 23'. The salt gives off its water of crystallisation at 160° C, turns yellov and
gives off ammonia at 170^, and froths up considerably at higher temperatureB. The
inactive eodium^salt crystallises in the monodinic system, the ordinary combina-
tion being a> P . oo P a> . oP . + P. Inclination of the fiices, oP : ooPod « 144<'46';
ooP : odP, in ^e plane and of the oblique diagonal and principal axia » 51® 38^;
4- P : + P B 112° 63'. The salt often forms twin-crystals, with the faee of jon;-
tion 00 P 00. One pt. of the salt dissolves in 1'19 pts. of water at 12*6° C.

Normal banum-salt, C*H^aN0«.2HK).— -The active salt crystallises in very dender
silky needles soluble in water, and giving off 14'4 per cent water at 120^ G. (Des-
saignes). The inactive normal salt forms an unc^tallisable gummv masa (Wolff).
The basic barium-salt ia obtained by gradually adding hydrate of banum to a hot and
rather strong solution of the normal salt The liquid solidifies on cooling in a eiystal*
line mass, but by recrystallisation from boiling water in a vessel prote^ed from the
carbonic acid of the air, this salt may be obtained in rather large shining prisma oon-
taininff 2C^H'BaN0'.Ba'0 + 5HK). In vacuo, the crystals give off 3 at water; when
heated to 160° C. they lose 16*4 per cent, and the residual salt contains, aoeordingto
Dessaignes, 57*05 per cent. BaK), agreeing nearly with the formula C*H*Ba'NO|,
which requires 57*55 per cent. This is the formula of the normal salt of a dibaaie
acid ; but since aspartic acid is in all probability an amidogen-acid, and such adds are
always monobasic, it is rather to be supposed that the true formula of the aalt dried
at 160° G. is 2C«H*BaN0^BaK). This formula requires onlv 55*0 per cent BaK); the
greater proportion obtained by Dessaignes may have been due to the presence of oa^
bonate of barium. (Gerhardt, Trai^ L 818.)

The normal cahium-talt is gummy, and tastes like the sodium-salt. The hatk salt
frequently forms prismatic crystals containing 2G*H*CaN0\GaH) -¥ 7HK) ; according
to Dessaignes, it gives off 8 atoms of water at 160° G., and is then reduced to
G*H«Ga«NO*.

Maanesium^alts. — ^The normal salt forms crystalline crusts, soluble in about 16 ^s.
of boiling water, insoluble in absolute alcohol. The basic salt obtained fay dissolTuig
magnesia in the normal salt is a gummv mass.

Aspartate of Zinc is a white non-dehquesoent salt. AsnartaU of niekd is obtained
by evaporation in a ^;reen fissured mass. An aspartate of iron is precipitated on add-
ing a solution of basic aspartate of magnesium to sesquichloride ox iit>n.

Aspartates of Copper. — The normal salt of the active acid exists only in solution.
A basic salt is obtained by adding a solution of the normal barium-salt to a hot wh-
tion of sulphate of copper. The Uquid on cooling deposits pale blue, very light crys-
tals which, according to Dessaignes, contain G^fiH)u'N0*.5HH) (or rather, perhaps,
2G*H*GuN0*.Cu«0 + 9HK>), and give off their water at 160° G., leaving the anhy-
drous salt G*H■Gu'NO^ Inactive aspartate of ammonium forms a bluish precipitate
with copper-salts. (Wolff.)

ASr ASIOLITE — ASPHALT. 425

AMpariaies of Lead,^Tl» normal lead-salt, C^H<PbNO\ is obtained hj precipitate
jqg a solation of acetate of lead with aspartate of potassium or basic a8pa]rtate of eal-
daln. On mudog an anunoniacal solation of normal acetate of lead with inactive
aspartate of sodium, a curdy precipitate is formed, and the filtered liquid, if diluted
with a considerable quantity of water, deposits, after two or three days, nacreous
aystala united in yery hard spherical masses. These crystals are anhydrous, and
contain 63*88 per cent of lead-ozide, agreeing with the formula 2C«H*PbN0*.PbK>,
which requires 64*6 per cent PbK). a£e formuLi G<H*PVO«, analogous to that of
the basie aspartates examined by Dessai^es, would require 66*1 per cent of lead-
oxide (Pasteur). The sodium-salt of active aspartic add also forms a precipitate with
ammnniawi] acetate of lead, and the liquid aft^wards deposits hard radiated nodules
containing 65 per cent lead-oxide ; these, however, are nothing but a basic acetate of
lead. (Pasteur.)

Aapartate of Mercury, — Mercuric oxide, boiled with aspartic add, forms a white
powder, containing, when dried at 100<^, 2C*H*HgN0^Hg*0, a composition analogous
to that of Paateur^s basic lead-salt (D ess aign es.)

Aspartates of Silver. — When nitrate of silver is added to a slightly alluline solution
of aspartate of ammonium, a predpitate is formed, which disappears on stirring, and
the liquid, after 24 hours, yields white, heavy, entangled crystals of a basic salt The
mother-liquor, left to crystallise, deposits yellowish crystals of the normal salt,
C*H«AgNO«. The basic salt appears to be C*R*AffO\ This formula requires
66'86 per cent oxide of silver, and the mean of sev^^l analyses made by different
chemists, and not differing by more than 0*2 per cent, gives 66*7 per cent. This salt
appears then to be really a dibasic aspartate. Pasteur finds, however, that the same
salt, when merely pressed between paper, and then dried for 24 hours at the ordinary
temperature, agre^ in composition with the basic lead- and mercuzy-salts, its formula
bdng 2C*H*A^0*.AgH>. The active and inactive adds yield silver-salts identical in
composition. (Pasteur.)

Aapartate (?) of Ethyl. — When malate of ethyl is saturated with drjr ammonia-
gas, the liquid becomes heated, and in a few days solidifies to a radiated crystalline
mass^ which, after being drained, and then washed with ether, consists of pure mala-

mate (or aspartate) of ethyl, ^ CK* [ ^' ^^ ^t^er treatment with ammonia, it
is converted into nialamide [ ? asparaginej. (Pas teur.)

ASPJLBZO&ITa. A variety of cordierite [3(Mg<O.SiO<) + Fe^O.SiO* +
2(2Al''0'.3SiO')l, in which the magnesia is partly replaced by water. The two
minerals crystallise in the same form, and crystals are found consisting partly of
eordierite, partly of aspasiolite, the most complete transitions from one to the other
occurring in the same specimen. Moreover, both minerals contain the same propor-
tiotts of silica and alumina ; but aspasiolite contains less ma^esia and more water
than cordierite, the difference being that 1 at. of magnesium in the latter is replaced
by 3 at of hydrogen in the former (or 1 at of magnesia by 3 at of water). Similarly
it is found that 1 at of iron or manganese may be replaced by 3 at H without altera-
tion of crystalline form. This kind of isomorphism, called polymeric isomorphism,
was discovered by Scherer; it was first noticed in the minerals cordierite and aspa-
eioHte. (Pogg. Ann. Ixviii. 319.)

AMWrntLTAMMXa ACJXB. A variety of tannic add obtained by Schwartz (Ann.
Ch. Pharm. Ixxx. 333) to be contained in woodruff (Aspemla adorata). Schwarz
assigns to it the formula C"H'0*, but it does not appear to have been obtained in
a state of purity. (See also Rochleder, Ann. Ch. Pharm. Loxiii 64.)

AflVSAinbA 01M>»ATA> The herb of this pliant contains cumarin, aspertannie
add (?), rubiehloric add, dtric add, and probably catechu.

ASraAST. Compact Bitumen, Mineral Pitchy Jeu^a Pitch, Bitumen Judaicum,
Jiidenpeeh, Erdpech, Bergpech, Goudron minlral. — A smooth, hard, brittle, black,
or brownish-black, resinous mineral, having a conchoidal fracture, and a streak lighter
than the broken surface with which it is made. Specific gravity 1 to 1*68. Odour
bituminous, becoming stronger by friction. Melts at about 100^ C, easily takes fire,
and bums with a bright, but veiy smoky flame. Like all bituminous substances, it is
a product of the decomposition of vegetable matter, consisting chiefly of hydrocarbons,
with variable quantities of oxygen and nitrogen, and yields by dry distillation a small
quantity of ammoniacal water, a peculiar empyreumatic oil, and a residue of charcoal
mixed with variable quantities of inorganic matter. It dissolves partially in alcohol,
more easily in oils both fat and volatile ; it is also dissolved by alkalis and alkaline
earbonates.
.Asphalt is found in most parts of the world, sometimes pure, sometimes associated

^ e asphalt ii firani on the ihatea ot tbc

are ne ai (1m liquid state at ths bottom, and liniw to tlia

and Iv i, which an thrown upm the shcaa. Id Ttinidid

but t JQ «iiaimfereDe^ otdd and solid neai the ahon, bql

hov ns *nd soflnsas towuds the eentie. Asjdult is aln

dr Booth America, and tvHoiu paxtji of £<c^qi^

Mpt de I'Ain), it fonna a drpont 2600 ft. bs^ snd

tons annually. At Bechalbronn aod Lobsum, in

ana mass is found, called jtomk de StrnAaur^, to^

containing about 12 pec cent, of bilnmiwis nator.

lartement dee Landes. there is a siliceons sand, iai-

of bitomen. In the Val de Tnvcn, Benlchllel.

fcrf^^^iftBxaa formatinn, stionelv impregnated with asphalt, which is nsed for

g*^' j^iposBS, In the British IslBl^ asphjdt is foond at the Poldiee minfl in

^'^^^/sMT Uatlock in Derbyshire; at EsngtuDOnd Hill in Sbn^abire ; and at

Vfo^fs^ n««r Bristol ; also in limestone mar Glasgow ; in freeslone near Edia-

^L^ • ia the satidfllone of Caithness ; and eenerallj throogfaoat the Oiknna.

^^hslt is sepaimted from the minerals wiui which it ia aaaodated. either \rj boQing

^j^ wattf, which caosee the bitumen to mn ont in the melted state, or bj the aecicoi

^brdrochloric acid, which diasoli-n carbonate of ealciiun and leaiee the asphalt, or

^h oil of turpentine, which dieBolva out tJie bitamen.

The fbllowing table contains the results of analyses of varioiia kinds of asphalt :
■ is asphalt fnim Coxitambo inPera ; h from Baslennes ; c bora PoDt-da-Chltna,
Aare^ne; i( from t^e Abnizd near N^es ; « fiom PontnaTej; yirom Cuba:

Carbon . . 88B8 88-70 78fO 761S 77-6*

Hydngea 6-66 6-88 8-80 9-41 7'8« 7-23 6-^7

Oiygen ( ,.,. ,.,, 280 10-34 836 a3-98) ,.,

NittSgen • ^^^ ^*' l-sa 231 1-02 l-37i **^

Ash , . — — 8-4S 180 6-13 — —

100-00 10000 100-00 100-00 100-00 100-00 100-00

According to Boneeinganlt (Ann. Ch. Phys. [2] Ixir. 141), asphalt or compaM
bitamen is a roiztum of two deGiiite subatancei, vu. atphdtaif, which ia fixed and
salable in alcohol, and prfrn/ene, which is oily and Tolatile. The gieal^ part of (he
latter may be volatilised by Aiiitilling the asphalt with water.

Pttnlaie (&om the asphalt of Bechelbmnn) forms, when dried Orer chloride of
Calcinm and rectiUed, a pale yellow oil having a faint taate and bitnminons odaar.
SpcdEIc grsTity 0'861 at 21° C. Does not b^me solid at 12° C. It stains paper,
and boms with thick smoke. Boils at280°.farming arapODrof speciflcgraTilj EI'4Ij.
It contains, according to Boussingauit, 87 '2 per cent, carbon and 121 hy&ogen, awn-
ing nearly with the fbrmula C^H", which fi>r a condensation to 2 vols, gins the
n^iOQC"]ensi^ 9-6.

Atphittem is obtained pore \>j henting asphalt for 48 hours to 2fi0° C, iriierel^
tbe petrolene is completely volatiliaed. It ia a black solid substance, having ■ strong
lustre and conchoidal fractnre. It becomes soft and elastic at about 300° C, decom-
poses before it melts, and bitrus like a resin. It giree Inra^yiiB 74-2 per cent. C,
and S'9 H, whence Bouseingault deduces the formula C^HbO*. Oerhaidt pref«n
C"H'*0', and sn^;Gets that aspbaltene may be formed by the oxidation of petroloui.

Aiphait-eiL — Asphalt yields by dry distillation, a yellow oil consistine of hydro-
carbons mixed with a aniall quantity of oxidised matter. It begins to boil at 90° C.
but the bailing paint gradually rises to 250°. The portion bolting betweetn 90° and
200° has a specific gravity of 0-817 at lfi° C. ; that which boils between 200° and
2S0° has a specific gravity of 0-868 at 1S° C. Bolh portions gave by analysis aboni

Asphalt-oil, treated with nitric acid, is tiansfonned into a resin, having the odoar
of musk and the taste of bitter almonds. On treating the oil with strong sulfJinrie
add, part dissolves, while the rest floats on ths surface. This latter, when decantfd,
washed with potash, and rectified, yields an oily mixture, whose boiling point nngs
from 90° to 260° C, and density from 0784 to 0-887 at 16° C Subjected to ftac-
tional distillation at ioterVBll of 20° or 30° C, it yields a number of oila grmdnally
* Abb. Ch. FhJPi. [1] lixlU.4n. t Add. UId. it. sa. t Dlail. polfteehD. Jl IxtU.HL

ASPHODELUS — ASPIRATOR. 427

inereuing in density, but agreeing yeiy nearly in composition, the mean resnlt of their
analysis being 87 '6 per cent, carbon, and 12*5 H, a proportion agreeing with the
formula itCIH*. It agrees also with Bonssingault's analysis of petrolene. All these
oils have nearly the same odour, are insoluble in water, but Teiy soluble, in alcohol
and ether. Strong sulphuric add scarcely attacks them. They are insoluble in strong
nitric acid, and on boiline the liquid, the nitric add Tolatilises, and there is formed a
reiy small quantity of a heary yellow oil.

Asphalt was used by the andent Egyptians in embalming, and appears to have been
employed in the constraction of the walls of Babylon. It is now used, mixed with
saiid, chalk, ground sandstone, &&, for pavement, for making water-tight tanks and
eoT«rs, as a coating for tubes of glass and iron used for couTcying gas or water, and for
various other puiposes of like nature.

Artificial or CrOB^iar Asphalt is a mixture of sand, chalk, or, lime-stone with the
thick pitchy reddue obtained by eyaporating off the more yolatile portions of pas-tar.
The mineral substance must be strongly heated to expel moisture and adhering air,
the presence of which would preyent the pitch from penetrating thoroughly into the
piaes of the mineral, and added to the pitch while in the melted state. The pitch
should also be yery strongly heated, but not enough to char it. This artificial asphalt
is used in the same way as the natural asphalt, for payements, tanks, &c

JkBWMiO'DMMtJIBm The bulbs of AaphodHU de JSardaiffne, of Aaphodelua racemoaus,
and other spedes of the same genus, are said to contain a fermentable substance from
which aloonol may be prepared. According to Landerer, an excellent glue may be
obtained from the bulbs of A, raoemosM and A. fisiulostu by washing them with
water, drying them thoroughly in a stoye, grinding them to coarse powder, and
"^'■^^"g the powder with water.

AffnOULTOB. An apparatus first deyised by Brunner for drawing a stream of
air through a tube or other yessel. The simplest form of it is a cylindrical yessel
A (fg. 76X o^ '^ ^^ ^ plate to hold water, haying a cock a near the bottom, and
three apertures doee<I with corks 6, c, d on the
topi h is connected with the yessel through j^. 76.

which the stream of air is to be drawn ; c is for f^^ ^ ^

the insertion of a thermometer, and d to pour J J

in water. The yessel A being filled with water, ^^h

the raertures c and d dos^ and the coch a ' ^

opened, the water runs out ; and as air can only
enter by the bent tube «, inserted into the
canning 6, a stream of air is drawn through the
apparatus with which the other end of this tube
is eonnected, the yolume of air thus drawn "^

Enough beixig exactly equal to that of the
water which runs out at A, Instead of the
metal cylinder, a glass yessd may be used,
haying a stopcock at the lower part of its
aide.

Regnault^ in his analysis of air, used a cy-
lindrittl metal yessel with eonical tenninations,

and haying at the bottom, a stopcock to which was attached a short glass tube bent
upwards, so that the small column of liquid which remained in it when the yessel was
emptied of water might preyent air from entering at the bottom The advantage of the
corneal terminations is that the yessel can be more completely filled and emptied,
and the yolume of water which runs from it, more exactly measured.

In all these forms of aspirator, the refilling of the yessel with water is yeiy
troublesome, especially when large quantities of air are to be drawn through. To
obyiatethis inconyenience, an aspirator has been contriyed by Brunner, consisting of
two equal (r^lindrical vessels placed one above the other and communicating by tubes
whidi can be opened or dosed, so that» when the water has run frt>m the upper to
the lower vesset the apparatus, turning for the purpose on a horizontal axis, may be
Inverted bo as to bring the empty vessd to the bottom, and the full one to the top ;
the water may^ then be again made to run without the trouble of refilling.

H ohr^s aspirator has the form of an ordinaiv gasometer, consisting of two cylindrical
vessels, the inner of whidi, of rather smaller diameter than tiie outer, is dosed at top,
and inverted in the outer which contains water. The inner vessel is balanced by a
weight passing over a pulley, as in the large gasometers used at gas-works. The vessel
Unough which the air is to be drawn is connected with the inner vessd \i^ a bent
tube passinff through the outer vessd near the bottom and terminating within the
rveaacE

B—B^

428

ASS ACOU — ASSAM AR.

Fig.n.

A simple apparatos, servuig both for aspirator and perspirator is described by Dc
F. Guthrie (Phil. Mag. [4] xv. 64).

An aspirator which works by a constant stream of water and does not moan
any filling or emptying of yessds, has been contrived by M. W. Johnson (CheoL
Soc. Qu. J. iv. 186). The principle of this apparatus is the same as that of the viter*

blast used in the Hongarian mines. The appantu
consists of a small hoUow cylinder A^ of brass or glass,
open at both ends, and connected with the Tesad
through which the air is to be drawn, by the lateral
tube C. A straight glass tube B is fitted to the lover
end of the cylinder A, and the upper end of that
cylinder is attached by a caoutchouc tube to a vater*
tap supplying a constant stream* On opening the tap^
the water, as it runs down, cazries the air in the cjlin-
der A along with it and the air in the bteral tube C
is then driven in by the external pressure. In this
manner, a stream of air is made to pass from C to i aa
long as the water is running. It is best not to open
the tap to the fulL For a cock { of an inch in
diameter, the cylinder A may be 2 in. long and 3 in.
wide \ B \ uu long and } in. wide ; C also 1 in.loi^
and } in. wide. The volimie of air drawn throngh this
aspirator is not equal to that of the water which rans
away. With the tube B, 8 in. long and | in. iride, John-
son found that, for every cubic foot of air drawii in, only
0*69 cub. in. of water was expended. It ii dnr,
therefore, that this form of aspirator cannot be used
when the volume of air drawn in is to be exactly
measured. In that case one of the aspirators before de-
scribed must be used. When only small quantities of
water are run out, it is sufiScient to receive the water
in a craduated measure and determine its volame
directly. When a large aspirator is used and has to
be filled several times, its capacity .must be previously determined by filling it with
Water from a flask of Imown capacity.

This volume of air determined by direct measurement of the water ran out, most of
course be reduced to the standard pressure and temperature, 0^ C. and 760 mm., the co-
efficient of expansion for each degree centigrade being 0*003665. A correction is abo
required for the quantity of aqueous vapour in the air, which is saturated with mois-
ture. To determine l^e alteration of volume thus produced, we must look in the tables
of the tension of aqueous vapour for the tension corresponding to the obserred tem-
perature. Let this tension expressed in millimetres of mercury be/; also let A doiote
the height of the barometer, t the temperature in centigrade degrees ; « the obamvd
and if the corrected volume of the air : then

if ^v

760 ' I + 0*003665 . t

The Brazilian name for the Bura hranlientu Mfff^
a euphorbiaceous tree, the bark and sap of which contain an acrid very poisoDovi
principle. The thickened sap and the decoction of the bark exert an emetic actica,
produce ulcerating pustules on the skin, and are used as a remedv for elephantiaa&
The natives also use them to prepare poisonous drinks, against which no antidote ii
known. (Mirat and Q-ilbert, Pharm. Centr. 1849, p. 30.)

ASSAMLAJU (From assare to roast, and amarui bitter.) This name was given
bv Reichenbach to the peculiar bitter substance produced when gum, ngar, staid),
gluten, meat, bread, &c. are roasted in the air till they turn brown. Beichenbaeh
(Ann Ch. Pharm. xlix. 3) prepares it by roasting thin slices of bread till they become
black-brown, treating the pulverised product with absolute alcohol, evaporrang to a
syrup, again treating with alcohol, &c till a residue is obtained complet^y solnble in
alcohol. The alcoholic solution is then mixed with ether, which precipitates a P«<^^
brown substance ; the decanted liquid is evaporated ; and the residue carefully heated
till it is dry. Y olckel (Ann. Ch. Pharm. Ixxxv. 74) preparcs asBamar in a sonilar
manner, frt>m the brown tarry liquid obtained by the dry distilUtion of sngar or
caramel, after neutralising the add contained in the liquid with earinsiate of aodram,
and evaporating.

Assamar, according to Reichenbach, is a yellow transparent solid; butaeoordiqg

ASTER — ATAC AMITE. 429

to Volckel. it 18 a reddiah-yeUow syrapj liquid, which does not solidify till it b^ns
to decompose. It is extremely hygroscopic, and dissolTCS in water in all proportions.
When heated, it melts (Beic henbach), bscomes more fluid, and at 100^ C, decomposes
and becomes darker in colonr/ after which it no longer dissolves completely in water
(VolekelX The aqneons solution is neutral, and reduces nitrate of silyer when
heated. Assamar is dissolved by potash, and acids precipitate from the solution, a body
of different composition. Yolckel assigns to assamar the formula C**H^*0" ; but it is
donbtfn) whether the substance so-ci£ed is a definite compound, or has oyer been
obtained in the pure state.

ASTXB^iniFOIiIVM. Sea Startoort. — The ash of this plant> which grows in
salt-maishesy is very rich in chloride of sodium. The several parts of the plant
gathered towards the end of September, were found by Harms (Ann. Gh. Pharm.
zeiy. 247) to yield ash of the composition and amount given in the following table :

Ash per cent • • • •
Containing, in 100 pts., after
deducting charcoal and sand :

Carbonic acid (anhyd.)

Sulphuric acid (anhyd.)

Phosphoric acid (anhyd.)

Silica (anhyd.)

Chloride of sodium

Chloride of potassium

Soda ....

Potash ....

lime ....

Itlagnesia •

Seequiphosphate of iron

Ttfanganaso-manganic oxide

Root-Iearet.

stems.

StemoleaTM.

Flowei

14*9

8-7

16-2

9-4

3-4

8-3

4-2

3-7

2-7

1-8

10-6

0-6

1-7

10-8

0-6

0-8

66-5

68-5

60-2

300

3-7

141

—

140

1-4

13-6

26-4

4-5

4-8

7-2

2-2

1-7

6-7

2-3

trace

A native sulphate of magnesium and sodium, S0^MgNa.2H'0
ooeuning in^ white, opaque, prismatic ciTstals, together with ordinary sulphate of
magnesium, in the bitter salt-marshes on the eastern side of the mouth of the Volga.

A glass flux resembling aventnrin, but containing crystals of a
cuprous compound, which by reflected light exhibits a dichroitic iridescence of dark
red and greenish-blue. To prepare it, a mixture of 80 pts. of edlica, 120 lead-oxide,
72 carbonate of soda, and 18 anhydrous borax, is fused either with 24 pts. of scale
oxide of copper, and 1 pt of scale oxide of iron, or with 5 pts. of lime, 26scale oxide
of copper, and 2 scale oxide of iron. The mixture is fused in a hessian crucible, at
the heat of an ordinary air-fumace, and left to cool slowly in the furnace. The first
mixtare melts more easily than the second, and yields larger crystals. The dichroitic
irideeoence is particularly beautiful on cut and polished surfaces. (Pettenkofer,
AbhandL d. naturw. techu. Commission bei d. Akad. d. Wiss. eu Miinchen, p. 134.)

A variety of mica found at Brevig in Norway. It con-
tains silica, alumina, feme oxide, magnesia, potash, soda (a trace), ferrous oxide,
manganous oxide, lime, and about 3 per cent, of water. The amount of iron is
unusually large. Fluorine is absent. Before the blowpipe it melts easily, and with
intomeseenoe. Colour pinchbeck-brown, varying to nearly a golden-yellow in the
thinner parts. The crystals are often united in beautiful stellate and floral groups :
hence the name. (Scheerer, Berg- u. hiittenmannische Zeitimg, 1864, s. 240.)

AVJLCAMITM* A native oxychloride of copper, originally found in the desert
of Atacama in Peru, and since observed in other localities, viz. in some silver mines in
Pern, in the districts of Huasco Bigo and Aconcagua in Chili, in the lavas of Vesu-
▼iua, and in the mines of Schwarzenberg in Saxony. According to the analyses of
Kl^roth, J. Davy, Ulex, and Mallet, it contains CuC1.3GuH0, or Oua-¥ Z(OuO.HO).
Berthier (Bammelsb. Handw. i 66), found in a specimen from Cobna, twice the amount
of water given by the above formula. F. Field (Chem. Soc. Qu. J. vii. 194), deduces
£rom his analysis of a specimen from Copiapo in Chili, the formula OuCl + SCuO +
6HO, at CnCLSCuHO.fi'O. It forms small rhombic ciystais, varying in colour fi?om leek
to emerald green, and generally ag^pregated in crystalline groups. According to Dion-
teiro (Phu. Mag. [4] xiii. 470), it occurs at Serra do Bemoe near Ambriz, on the.
west eoast of Africa, in small translucent crystals, odP . it oo, on malachite and quartz.
It dissolves easily and completely in acids, anl in ammonia. It is used for the ex-
tnction of copper.

430 ATHAMANTA — ATHERl A.STITE.

L OWMMOmvux. The root and seeds of this plant oontain
a peculiar bitter substance, not yet examined, together with athamantin (see next
article). The leaves contain, not athamantin, bat a bitter principle and a TolatHe oO,
which is obtained by distilling the herb with water. This oil has the oompositioii of
oil of tnxpentine, C'^H** ; it smells like elder, has a density of 0*841, and boili at
163° C. Wil^ hydrochloric acid gas, it forms an nncrystidlisable liquid, whieh ii
colonrless after distillation, lighter wan water, and boils at 190° G. It cuDes not appear
to be related, in composition or properties, either to athamantin or to oil of valenao,
which is produced by the decomposition of the latter. (Schnedermann and
Winckler. Ann. Ch. f harm. li. 336.)

ATHAlgAWmr, C«H**0'. (Gm. zii. 101 ; Cherh. iv. 269.)~A6abBtaneeaQBt-
ing in the root and seeds of AtKamanta oreoselinum, and other species of the same genoi.
It was first obtained in an impuro state by Winckler (Bnchn. Bepert xxvil 169),
afterwards propared puro and more completely examined by Schnedermann (Ana.
Ch. Fharm. li. 315). It is extracted by treating the roots and seeds with aloohoL
The solution, if not too concentrated, yields the athamantin, by spontaneous eraport*
tion, in crystals, which may be purified by pressuro and reaystaUisation. It fonns
colourless, fibrous, silky crystals, or sometimes rectangular prisms with tnmcated mm-
mits ; has a rancid soapy odour, and a slightly bitter acrid taste. It is insokble in
water, and melts in it at the boiling hea^ in drops which sink to the bottom of the
vessel. It dissolves readily in alcohol and ether, and the solutions are not precipitated
by metallic salts. It melts between 60^ and 80^ C. It does not volatilise nndeeom-

S>sed, although it can sustain a tolerably high temperature without deoompoaitioD.
y dry distillation, it yields valerianic acid and other products.
Melted athamantin absorbs hvdrochlorio acid gas, and appears to enter into com*
bination with it, but on raising the tempeorature to 100° C, decomposition takes [dace,
and the atbamantin is resolved into valerianic acid and oreooelone :

C»*H«»0» = 2C*H"0« + C"H»«0»

> — , — ' N — , — ^ * , '

Athamantin. ValerUnIc Oreoadoae.

add.

When hydrochloric acid gas is passed into an alcoholic solution of athamantin, the
products formed are oreoselone ana valerate of ethyL Sulphurous acid acts on athaman-
tin like hydrochloric acid, a crystalline compound being formed at first, and soon afke^
wards oreoselone, valerianic add, and sulphurous acid gas. Concentrated snlphnrie add
dissolves athamantin and decomposes it in like manner. Athamantin heated with
caustic potash, yields valerate of potassium, and a white amorphous substance, whidi
appears to be a hydrate of oreoselone. Lime-water and baryta-water act in ti^e aanu
manner, but moro slowly. (See Orsosblonb and Pbucedanut.)

TricidoratKamantin^ (p*H^Cl*0', is a light yellow resinous body, produced by mixing
an alcoholic solution of athamantin with water, and cautiously adcung dilute chlorine-
water, till the liquid smells slightly of chlorine. A corresponding bromine-compoand
appears to be formed by treatins athamantin with bromine-water.

Trinitrathamantinj C«*H"(NO*)«0', is formed, together with other substatntion-
products, by the action of cold fuming nitric acid on athamantin. Precipitated hj
water, it is a yellow pulverulent substance, scarcely wetted by water, easily solnble in
alcohol, ether, and ammonia, slightly in dilute nitric acid. (O^eyger, Ann. Ch. Pharm.
ex. 369.)

JLVBJLKOM or AOAVOB. Ptfffr HenricuSf Foumeau des paresseux.-^L kind
of ftimace, which has long since fiillen into disuse. The long and tedious operations
of the ancient chemists rendered it a desirable requisite, that their fires sbonld be
constantly supplied with fuel in proportion to the consumption. The athanor famace
was peciQiarly adapted to this purpose. Beside the usuu parts, it was prorided with
a hollow tower, into which charcoal was put. The upper part of the towei; when
filled, was closely shut by a well-fitted cover ; and the lower part communicated with
the fire-place of the furnace. In consequence of this disposition, the charcoal sob-
sided into the fire-place gradually as the consumption made room for it ; bat that
which was contained iu the tower was defended from combustion by the exdosion of
a proper supply of air. U.

or ATTAJU The Indian name of volatile oil of roses.

— — » — — . Thf name given by Weibye to a mineral from ArendaL

bearing an external resemblance to scapolite. In composition it appears to be related
to epidote, as will be seen by the following comparison of its analysis by Berlin
(Pogg. Ann. Ixxix. 302) with that of epidote fi:om Arendal by Scheerer (ihid.
xcv. 603).

ATLAS ORE — ATMOSPHERE. 431

Alb«rlMtite.

RpMota.

Silica

. 3800

37-59

Alumina

. 2410

20-73

Ferric ozido

. 6-22

16-67

lime

. 22-64

22-64

Magneaia

. 2-80

0-41

Water .

. 6-95

211

100-71 100-06

Beriin does not state whether the iron in atheriastite is present as a ferrous or as a
ferric eompoand ; bnt it is probably all in theform of ferric oxide. (Scheerer, Handw.
d. Chem. 2*« Anfl. i. 406.)

OXa. See MAiACHnx.

See Satin Spab.

The name given by Kane (Compt rend. iz. 666) to a pro-
dnct which TolatUises in red yaponra, and condenses in roddisn-green laminse, in the dry
distillation of litmylic acid (eiytbrolitmin) and litmic acid (a mixture of azolitmin
and spanioUtmin), with lime.

ATMUMMOOVB. An instrument inrented by Babinet (Compt rend, xxrii.
629) to measure the rate of evaporation.

ATlKOflraSBa* The gaseous envelope which surrounds any solid or liquid
body is called an atmosphere (dr/iat smoke, <r<p<upa globe) ; thus we speak of the atmo-
sphere of oxygen which spongy platinum attracts to its Borface, or of the reduction of
a metal in an atmosphere of hydrogen. The term atmosphere is, however, especially
employed to designate the ^^aseous matter which encircles the solid and liquid portions
of the earth's sui&ce, forming the air or earth's atmosphere.

Of the existence of matter above the visible crust of the globe we have striking
evidence in the resistance offered to bodies moving near the earth's surface and
in the effects produced by wind ; but the most direct proof that the air is attracted
by the solid and liquid portions of the earth's body, or that the air has weight, is
afforded by the fact that a vessel filled with air weighs more than the same vessel
fiom which the air has been removed, and that a dosed vessel filled with air weighs
less in the atmosphere than it does in a vacuum. That the air possesses weieht was
suspected even before the time of Aristotle ; but Galileo, in 1640, was the first wno gave
the right explanation to the fact observed by the Florentine pump-makers, that they
were unable to raise water bv a suction-pump more than 32 feet, and supposed bv
them to show that nature haa a *' horror vacuL" Ghdileo's explanation was beauti-
fully verified by his pupil Torricelli, who argued that, if the atmospheric pressure
supports a column of water 32 feet in height, it must support a column of mercury,
which is nearly fourteen times heavier than water, of aMut 30 inches in height ;
and thus the first barometer was constructed, the empty space above the mercury in
the tube being called, from its discoverer the, ToriceUian vacuum^

The atmosphere, then, having weight, or obeying the laws of gravitation, forms a
part of the earth's body, and accompanies the solid and liquid portions in their axial
and orbital motions. The height to which the atmosphere extends above the earth's
surface is not the same at all points, since, owing to the increase of the attractive
force at the poles and its diminution at the equator, and to ' the action of the
centrifugal force, as also to the increase of temperature, the atmosphere presents,
Hke the earth's solid body, the form of a spheroid, whose polar is considerably
shorter than its equatorial diameter. The absolute height to which the atmosphere
extends above any point on the surface of the earth has not been determined
with any degree of certainty: for, as air is an expansive fiuid, and the volume
which a given quantity of air occupies is directly dependent upon the pressure
and temperature to which it is exposed (in accordance with the known laws regu-
lating the expansion and contraction of gases), the density of the atmosphere is not
uniform, but diminishes as the distance from the earth's surface increases: the
exact point at which the atmosphere terminates is thus very difScult to determine.
That there is, however, a Umit of the earth's atmosphere is rendered certain from the
fact, ascertained by the observations of the occultations of stars or satellites, that our
moon and most of the planets are destitute of an atmosphere like ours, which
eoold not be the case if the terrestrial air were difi\ised throughout space. Br. Wol-
laston supposed that a gas cannot expand beyond a certain limit> and Faradav has
shown that in the case of the vapour of mercui^ such a limit really exists : hence
there can be no doubt that there is a definite limit to the atmosphere ; and, from
calculations of the time during which the twilight extends to the Ecnith, it appean

432 ATMOSPHERE.

that the atmoephere reaches, in a state of sensible density, to the mean height of fmm
forty to forty-five miles above the earth's sonGAoe.*

Barometric observations at various heights above the sea-level prove condouTe'j
that Galileo's theoxy of atmospheric pressnre is oonect. The first of these bannnetrie
measurements, made on the Puy-de-D6me by Pascal's advice in 1648, showed that the
column of mercury supported by the atmosphere sinks as the distance from the certh's
surface increases ; thus, at the sea-level, the mean height of the barometnc eoltumi ia
760 millimetres (29*92 English inches), whereas in Potosi, at a height of 13,220 feet, the
mereuiT sinks to a mean level of 471 millimetres. The average weight, then, of the
atmospnere at the level of the sea is, in our latitudes, that of a oolomn of merai^
7C0 mm. in height^ or equal to a pressure of 103*33 kilogrammes on a ac^uare dea*
metre (nearly 15 pounds on a square inch). This weight, the human body, ui comnoa
with all subistances existing at the bottom of the ocean of air, has to cany; and
although it may at first sight appear remarkable that the animal frame should he aUe
without diBCOmfbrt to bear a pressure amounting to several tons, yet it is certain that
not only is this the case, but that our bodies are arranged so that we cannot eziit with-
out thin pressure ; and as an effect of the weight of the air, it has been shown hj the
brothers Weber, that the human thigh-bono is, in certain positions of the bodj, le-
tained in its place, together with the ball and socket hip-joint, onlv by atmosphecie

gressure ; it is well known also that persons remaining for any length of time at gnat
eights above the earth's surface are inconvenienced by haemorrhage from the nose,
eyes, and mouth, owing to the small blood-vessels, unsupported by the atmoepherie
pressure, being unable to withstand the forcible propulsion of the blood throogh the
system.

The relation according to which the density of the air diminishes in ascending; ii
easily deduced firom the well-known law of Mariotte, that the density of a gts
is directly proportional to the pressure to which it is subject ; whence it foUowB that,
alterations of temperature and variations in the force of g^vity at different heights
not being considered, the density diminishes in a geometrical ratio, as the height in-
creases in an arithmetical ratio. It has been found by experiment that, when the
barometer stands at a height of 760 mm. it is necessary to ascend 10*5 mettei in
order to efiect a fall of 1 millimetre in the barometric column, or to bring the mercoiy

759
to stand at 759 mm., or at 760 * r^^r mm. Now we may assume, withoat appce-

760

ciable error, that the air throughout this space of 10*5 metres is of equal densty;

759
at a height, then of 10*5 metres the pressnre is 760 * =7^; : hence the air in the next

759 *

10*6 metres has only a density of r^ of what the lower layer had; and therefore,

in ascending through the second 10*5 metres, the barometer does not fall 1 millimetre^

759
but only ^^ of a millimetre, so that at a height of twice 10*6 metres, the barometer

760 *fCQ ^iso /7nft\«

will stand at 760 -jl^ - j^ - 760 • U^\ ; and as the density of the third kyer

759
of 10*5 metres is s^h times less than that of the second, the barometer at the height

' /759\* /759\* /759\'

of three times 10*5 metres, will be 760 • [yqq) " (790/ "* ^^^ " (760) ' "^^"^"^ ^'

then, at two places the barometer stands respectively at ^ b 760 * (=Xq) *d<I

(759\" . . . . . \7o9/

r^J , their difference in elevation is 10*5 m x (n — m);^ hence, inoi

these two equations the difference in height, H, between these two points expressed in
metres is

H « 18363 (log B - log B')
or in English feet

H - 60246 (log 2? - log F).

By means of this formula, we find that the pressure is diminished to ha]f its original
amount, and therefore the air expanded into double its original volume, at a height of
5528 metres or 18,136 ft. above the level of the sea, and that at a height of twice
5528 metres, the pressure is reduced to J of its original amount, and so on.

The mean temperature of the atmosphere, like its density, is not equal throngbont
the mass, but diminishes as the distance from the earth's surfiice increases, so tlut, at
a certain height above the sea-level, different for different latitudes, we arrive at a

* In order to gfve an Idm of the rrlatton between the earth's diamKer and the Mght of the *m-
aphere, ft may be atated, that if we represent the e«rrh by a globe of I foot In diameter, the 4tmoqk«ft
will be represented bj a layer of air ^ of aa Inch in height.

ATMOSPHERE. 433

lixte aboTO which the mean temperature of the air does not rise higher than the freezing
point, and tiiis line is called the level of perpetual snow. This regular diminution of
temperature in the higher regions of the atmosphere is to be attributed mainly to two
csoaes : Ist^ to the fiict that the air abeorbs but a small portion of the heating rays of
the son in tibeir passage to the earth, the lower zones of the atmosphere being heated
by contact with the warmer solid and liquid crust of the ^lobe ; and, secondly, to the
increiiae of latent heat which all gases undei;^ on rarefieKtion, producing a dinunution
in temperature. Besides this regular alteration of mean temperature of the yarious
zones of air above the earth, the various portions of the atmosphere exhibit great and
constant variation in temperature, owing to the unequal heating effects produced by
the son on the earth in various latitudes and at various times. The mean tem-
perature of any place, and therefore of the air above that place, is the resultant of the
amount of heat received from the sun, and that lost by radiation. These two con-
trolling causes are, however, never constant, either in the same or in different places,
aiid h^ce the temperature is continually varying. The chief factor representing the
diange of temperature, is the height to which the sun rises above the horizon, and the
intensity with which any point on the earth's suriace is heated, is proportional to the
eoeine of the sun's zenith-distance at that point ; thus, in the torrid zone, the srm's
eemth-distance varies ftom 0^ to 33°*6, or the cosine from 1 to 0'917, whilst in the
temperate and frigid zones the cosine of the angle varies from 0*930 to 0*367, and
from 0*731 to 0. We see from these numbers that, although many other circum-
stances, such as duration of day and night, and the thickness of atmosphere through
whidi the sun's rays have to pass affect the temperature, the warm climate of ^e
torrid zone is not subject to such variations as occur in the other portions of the globe.
The height at which the mean atmospheric temperatxire sinks below 0^ C, or the
hei^t of the snow-line, in different latitudes, is determined by many circumstances
besides those already mentioned, as, for instance, the geographical relations of the
country, neighbourhood of large masses of wat^, &c ; thus the snow-line on the
northern slope of the Himalaya is found at a height of 15,600 ft, whilst on the southern
6i<^ it rea<me8 only 12,200 ft. above the sea. Still the general descent of the line of
perpetual snow with increase of latitude is, notwithstanding these local irregularities,
plainly seen ; thus, under the equator, the snow line is not reached until 15,207 ft,
whereas, under the latitude of 60^, it is found at 3818 ft, and in latitude 75^, at
on^ 1016 ft above the sea^level.

& passing through the atmosphere, a portion of the solar rays is absorbed, the
amount of this absorption depending upon the thickness of the layer of air through which
the rays pass. Pouillet (Fogg. Ann, xlv. 25 and 481) concluded, from his own ex-
periments, tiiat when the sun is in the zenith and the atmosphere clear, the amount
of the sun's heat which is absorbed by passing through the air, varies from 18 to 25 per
cent of the quantity which enters the atmosphere.

The light of the sun is also partially absorbed and reflected in its passage through
the 4ir, and, according to Clausius (Pogg. Ann. Izxii. 204), out of 1000 rays of direct
sunlight entering the atmosphere, 750 reach the earth direct whilst 186 are reflected as
diffuse light and 64 are absorbed. For the more refrangible chemically active rays,
Bonsen and Hoscoe have lately determined the amount of atmospheric absorption and
reflection : for the numerical results of these experiments the reader is referred to the
article on the Chemical Action of Light Besides suffering absorption and reflection,
every ray of light which enters the atmosphere otherwise than perpendicularly to the
Hmifiwg surface, undergoes refraction, or is bent out of its course in the direction of the
denser medium, so that as we see the object in the direction of the tangent to the
carve as it enters the eye, all celestial objects appear higher than they really are. Ac-
cording to the experiments of Biot and Arago, the refractive index, nom the absolute
TacDum into air at 0^ C. and 0*76 m; pressure of mercury, is 1*000294 ; and hence the
lefractiTe power of the air is equal to 0*000588.*

Owing to the unequal heating effect whie^ the sun produces on the various portions
of the earth's suifruse, either from general or local causes, the temperature of the
atmosphere varies in every part of the ^lobe, and u the same part undergoes
oontinnal change, thus producing the motion of masses of air which we call wind.
Winds are invariably caused by the ascent of a heated mass of air, and the motion of
a colder mass to fill up the space thus left vacant ; the former of these gives rise to
currents in the higher regions of the atmosphere, whilst the latter produces the hori-
sontal currents which we observe at the surface of the earth. Winds may either be con-
lined to very narrow limits, as for example the sea and land breezes seen on every coast
or they may extend over a large portion of the globe, as is the case with the trade winds.
The fanner are causedby lo<^ circumstances depending upon the unequal heat-absorb*

* If tbtt Index of refracUon be ■■ », the refractive power U i»<sl. See Liobt.
Vol. L F F

424 ASPAETIC ACID.

of the active compound. Ordinary combination oo F . ooP od . — P . oP . -i-iiiP « .
Inclination of the faces oP : ooP oo = 119° 46'; c»P oo : » P « 123®. ThecrysUls
are nearly unalterable in the air, only in summer losing their lustre and transpareney,
and becoming milk-white on the surface. They decompose when dissolved in water,
but the inactiye acid being more soluble than the active acid, is not predpitated; i^
however, alcohol be added, an abundant precipitation takes place. The mactiTe hy-
drochlorate is decomposed by heat like the active salt.

The 9tclphaie, C*H'NO*.SO''H', is obtained bv gradually addins aspartic acid to strong
sulphuric acid heated to 60® or 60® C. in a wide glass tube, and leaving the tabe doKd
for a few da^s ; it then separates in large agglomerated prisms, which are lighter than
the mother-Hquor (D e s s a ign e s). The nitrate is obtained, like the hydrodilQiate^ in
beautiful crystals.

AspABTATES. — Aspaitic acid is monobasic, the formula of its normal salts hdng
O^H'MNO^. It likewise forms basic salts, the composition of which is not very deariy
made out The aspartates of the alkali-metals are soluble, and taste like broth. The
active and inactive aspartates agree in composition, and in most of their properties,
differing only in solubility, crystalline form, and relation to polarised light

The ammonium a.ndpotassium salts are very soluble and oijfficult to crystallise.

The sodium^saltSf C'H'NaNO^.H'O, are obtained by neutralising the acid with
caustic soda or its carbonate, and leaving the solutions to evaporate slowly; they
are perfectly neutral The active salt crystallises in prismatic needles belonging to
the right prismatic system, and terminated by faces of a tetrahedron inclined to one
another at about 106®. The four faces of this tetrahedron are either present alone, or
are much more developed than those of the opposite tetrahedron, which, if eqnidJy
developed with the former, would constitute a rhombic pyramid ; 1 part of this silt
dissoTves in 1*12 pts. of water at 12*2 C. The specific rotatory power of the solution
is —2® 23'. The salt gives off its water of crystallisation at 160® C, turns yeUov and
gives off ammonia at 170^, and froths up considerably at higher temperatores. The
inactive wdium-^alt crystallises in tJie monoclinio system, the orcUnary combina*
tion being oo P . oo P oo . oF . + P. Inclination of the faces, oP : oo P oo » 144° 46';
ooF : ooP, in the plane and of the oblique diagonal and principal axis ■* 61° SS";
+ P: +Pb112® 63'. The salt often forms twin-ciystals, with the &ce of jvnc-
tion 00 P 00. One pt. of the salt dissolves in 1*19 pts. of water at 12*6® C.

Normal bariumrsait, C^H^aN0^.2HK). — The active salt crystalliaes in very slender
silky needles soluble in water, and giving off 14*4 per cent water at 120® C. (Des-
saignes). The inactive normal salt forms an uncrystallisable gummy mass (Wolff).
The baMO barium-salt is obtained by gradually adding hydrate of banum to a hot and
rather strong solution of the normal salt The liquid solidifies on cooling in a ciystal'
line mass, but by recrystallisation from boiling water in a vessel protected from the
carbonic acid of the air, this salt may be obtained in rather large shining prisms con*
tainiuflr 2C*H«BaN0*.Ba«0 + 6H*0. In vacuo, the crystals give off 3 at water; when
heated to 160® C. they lose 16*4 per cent, and the residoal salt contains, according to
Dessaignes, 67*06 per cent. BaH), agreeing nearly with the formula C^H^BallOS
which requires 67*66 per cent This is the formula of the normal salt of a dibasie
acid ; but since aspartic acid is in all probability an amidogen-acid, and such adds are
always monobasic, it is rather to be supposed that the true formula of the salt dried
at 160® 0. is 2G^H«BaN0\BaK). This formula requires only 66*0 per cent Ba>0; the
greater proportion obtained by Dessaignes may have been due to the presence of C8^
bonate of barium. (Gerhardt, TraiS, i. 818.)

The normal calcium-falt is gummy, and tastes like the sodium-salt The batie salt
frequentl;^ forms prismatic crystals containing 2C*H'CaN0^Ca-0 + THK) ; according
to Dessaignes, it gives off 8 atoma of water at 160® C, and is then redooed to
C*H*Ca«NO^

Magnesium-salts. — The normal salt forms crystalline emsts, soluble in about 16 pt&
of boiling water, insoluble in absolute alcohol. The basic salt obtained by diasoln]^
magnesia in the normal salt is a gummy mass.

Aspartate of Zinc is a white non-dehquescent salt. Aspartate of nickel Ib obtaiDed
by evaporation in a green fissured mass. An aspartate of iron is precipitated on add-
ing a solution of basic aspartate of magnesium to sesquichloride of iron.

Aspartates of Copper. — The normal salt of the active add exists only in solution.
A basic salt is obtained by adding a solution of the normal barium-salt to a hot eola-
tion of sulphate of copper. The liquid on cooling deposits pale blue, vezy light crys-
tals which, according to Dessaignes, contain C*H*Cu«N0*.6H*0 (or rather, perhaps,
2C*H«CuN0*.CuH) + 9H*0), and give off their water at 160® C, leaving the anhy-
drocis salt OHK)u^0*. Inactive aspartate of ammonium forms a bluish precipitate
with coppeTHMats. (Wolff.)

ASr ASIOLITE — ASPHALT. 425

Atpariaiea of Lead.—Thtt normal lead-salt, O^H'PbNO\ is obtainad by precipitat*
ing a aahitioii of acetate of lead with aspartate of potassium or basic aspartate oi cal-
cxolD. On mixing an ammoniacal solution of normal acetate of lead with inactive
aspartate of sodium, a curdy precipitate is formed, and the filtered liquid, if diluted
with a considerable quantity of water, deposits, after two or three days, nacreous
oystala united in yezy hard spherical masses. These oystals are anhydrous, and
contain 63*88 per cent of lead-oxide, agreeing with the formula 2C^H*PbN0*J^bH),
which requires 64*6 per cent Fb'O. The formula G^H*Fb'0\ analogous to that of
the basic aspartates examined by Dessai^es, would require 66*1 per cent of lead-
oxide (Pasteur). The sodium-salt of active aspartic acid also forms a precipitate with
ammoniaful acetate of lead, and the liquid aft^wards deposits hard radiated nodules
containing 66 per cent lead-oxide ; these, however, are nothing but a basic acetate of
lead. (Pasteur.)

Aspartate of M&rewry. — Mercuric oxide, boiled with aroartic acid, forms a white
powder, containing when dried at 100°, 2C*H'HgN0^Hg*0, a composition analogous
to that of Pasteurs basic lead-salt (Dessaign es.)

Agpartatet of Silver. — When nitrate of silver is added to a slightly alkaline solution
of aspartate of ammonium, a precipitate is formed, which disappears on stirring, and
the liquid, aft«r 24 hours, yields white, heavy, entangled cxystals of a basic salt The
moth^Hquor, left to crystallise, deposits yellowish oystals of the normal salt,
C^H«AgNO«. The basic salt appears to be C^H»AgK)«. This formula requires
66*86 per cent oxide of silver, and the mean of several analyses made by different
chemista, and not differing by more than 0*2 per cent, gives 66*7 per cent. This salt
appears then to be really a dibasic aspartate. Pasteur finds, however, that the same
salt, when merely pressed between paper, and then dried for 24 hours at the ordinary
temperatnre, agrees in composition with the basic lead- and mercury-salts, its formula
being 2CH'A^0^jkgK>. The active and inactive acids yield silver-salts identical in
composition. (Pasteur.)

Aspartate (?) of Ethyl, — When malate of ethyl is saturated with dry ammonia-
gaa, tne liquid becomes heated, and in a few days solidifies to a radiated ciystalline
man, which, after being drained, and then washed with ether, consists of pure mala-

mate (or aqwrtate) of ethyl, ^ ^H? l ^* ^^ further treatment with ammonia, it

ia cooiverted into nialamide [ ? asparaginej. (Pasteur.)

JLSPASZO&ITH. A variety of eordierite [3(Mg>O.SiO>) + Fe'O.SiO* +
2(2AI^O'.3SiO')l, in which the magnesia is partly replaced by water. The two
minerals crystaUiBe in the same form, and crystals are found consisting partly of
eordierite, partiy of aspasiolite, the most complete transitions from one to the other
ooduring in the same specimen. Moreover, both minerals contain the same propor-
tions of silica and alumina ; but aspasiolite contains less maenesia and more water
than eordierite, the difference being that 1 at of magnesium in the latter is replaced
by 3 at of hydrogen in the former (or 1 at of magnesia by 3 at of water). Siinilarly
it is found tnat 1 at of iron or manganese may be replaced by 3 at H without altera-
tion of ciystalline form. This kind of isomorphism, called polymeric isomorphism,
was discovered by Scherer; it was first noticed in the minerals eordierite and aspa-
siolite. (Pogg. Ann. Ixviii. 319.)

JLMWXMTAMMIO ACXB. A variety of tannic acid obtained by S ch war tz (Ann.
Ch. Pharm. Ixxx. 333) to be contained in woodruff {AspertUa adorata). Schwarz
assigns to it the formula C*^H*0*, but it does not appear to have been obtained in
a state of purity. (See also Rochleder, Ann. Ch. Pharm. Ixxxiii. 64.)

ASFBMiriiA 0]>OXJLTA. The herb of this pUnt contains cumarin, aspertannic
acid (?), rubichloric acid, citric acid, and probably catechu.

AflVKAS/T. Comjoact Bitumen, Mineral Pitch, Jou^s Pitch, Bitunun Judaicum,
Jvdenpeeh, Erdpech, Bergpech, Goudron minirai. — A smooth, hard, brittle, black,
or brownish-black, resinous mineral, having a conchoidal fracture, and a streak lighter
than the broken surface with which it is made. Specific gravity 1 to 1*68. Odour
bituminous, becoming stronger by friction. Melts at about 100^ C, easily takes fire,
and burns with a bright, but very smoky flame. Like all bituminous substances, it is
a product of the decomposition of vegetable matter, consisting chiefly of hydrocarbons,
wnth variable quantities of oxygen and nitrogen, and yields by dry distiUation a small
quantity of ammoniacal water, a peculiar empyreumatic oil, and a residue of charcoal
mixed with variable quantities of inorganic matter. It dissolves partially in alcohol,
more easily in oils both fat and volatile ; it is also dissolved by alkalis and alkaline
aarbonates.
. Asphalt is found in most parts of the world, sometimes pure^ sometimes associated

436 ATMOSPHERE.

The eadiometrie determinatioiis of Bimseii and Begnault are on the ▼bole to be
preferred to any method of analysis of the air by weight, not only from their greater
accuracy, but from the simplicity of the apparatus employed, and the ease with which
small samples of air collected at yarious times and in drfiferent localitieB can thus be

analysed.

Buns en (Gkwometry, p. 71), in a series of analyses of air nuide on fourteen different
days in January and February 1846, amongst which the maximum amount of oxjgen
was 20-97 per cent and the TniniTmnw 20*84 per cent, found a mean of 20*93 per cent of

o^gen.

Regnault (Ann. Ch. Phys. [8] xxxvi. 386) has analysed a very hage number
of samples of air collected in yarious quarters of the globe in a uniform mamier,
.according to instructions given by him. The method of analysis employed rardy
gave acQfference of 0*02 per cent on the same sample of air. In more than one
hundred analyses of air collected in or near Fans, Regmuilt found a maximum amovnt
of 20*999 vols, of oxygen, and a minimum of 20*913 or a mean of 20*96. This diffe^
ence of 0*086 per cent is, according to Regnault, too large to be accounted for by ex-
perimental errors.

9 samples from Lyons, Montpelier, Normandy gave

from 20*918 to 20-966 p.c of 0.

30 samples collected in Berlin contained . . . 20*908 „ 20*998 „
10 „ „ Madrid „ ... 20*916 „ 20*982 „

23 „ from C^eneva and Chamounix . . . 20 909 „ 20*993 „

Of seventeen samples of air collected in Toulon Roads and other parts of the Medi-
terranean, fifteen gave similar results of 20*912 to 20*982 per cent oxygen, whilst two
samples collected froin Algiers harbour contained onljr 20*42 and 20*396 per cent
This abnormal result cannot be accounted for, but a similar phenomenon was obaerred
by Lewy.

6 samples taken on the voyage from liveipool to Vera

CruEgave 20-918 to 20*966 p. c of 0.

2 samples from Ecuador in S. America contained . 20'96 »

2 „ the summit of Pichincha, higher than

HontBknc 20-949 to 20*988 „

Eleven samples collected in the Asiatic seas frx)m 1848 to 1850, all except two, gave
normal results. On the let February 1849, the air in the Bay of Ben^ contained only
20*46 and 20*45 per cent, oxygen, and on the 8th March 1849 the air from abore the
Granges, collected during foggv weather, in presence of much decomposing animal
matter, temperature 35^ C, when cholera was commencing, oontained from 20*390 to
20*387 per cent of oxygen.

Air collected by Captain Sir James Ross in the Arctic seas gave the normal oom-
position from 20*86 to 20*94 per cent oxygen. The conclusion which Regnanlt diavs
from all these determinations, is that the atmosphere shows percejitible, thon^ Teiy
small, alterations in the amount of oxygen at different times and in different plteo.
This variation ranges frx)m 20*9 to 21*0 per cent, but from special unknown causes in
tropical countries, the amount of oxygen may sink as low as 20*3 per cent BnnBai's
analyses of the air in Iceland confirm these views.

Lewy (Ann. Ch. Phys. [3] xxxiv. 1) has also published a series of analyses of air
collected from various parts of the globe. The relative amounts of oxygen and mtrogen
were determined by Kegnault's eudiometric process, and the maximum difference be-
tween the composition of the same sample of air analysed at different times was ^^^
The air of Pans contained, in a mean of three experiments, 21*014 per cent of oxygen,
that of Havre 20*888 per cent, whilst that collected on the Atlantic gave 20*961 and
21*06; per cent, and in South America^ 20*996 and 21*022 per cent of oxygen. Hence
we can positively state that no greater difference exists between the composition of
the atmosphere as regards oxygen and nitrogen in different latitudes (some few apedal
cases excepted), than is found m the same ^ace at different times.

Frank! and (Chem. Soc. Qu. J. xui. 22) has lately determined the compositioii of
air collected by himself at different elevations on Mont Blanc, vis. at the Grands
Mulcts, at the summit, and at Chamounix. The conclusion which Frankland draws
from his experimental numbers is, that as far as the nitrogen and oxygen are eon-
cemed, the composition of these samples of air fdls within the limits of variation
noticed by former experimenters.

That the air is -a mechanical mixture and not a chemical combination of oxygen
and nitrogen is seen from the following facts : 1. The amounts of oigrgen and nitrogen
in the air do not present any simple relation to the combining proportions of these

ATMOSPHERE.

437

dementi, and are moreorer yariable. 2. On xnizmg oxygen and nitrogen gases in the
proportion in which they occur in air, no contraction or eyolution of heat is observed, and
the mixtoze acts in eyery way as air. 3. When air is dissolved in water, the proportion
between the oxygen and nitrogen in the dissolved air is qnlte different from that in
the nndissolyed air, this difference occurring in strict accordance with the laws of the
absorption of gases in liquids (see GAssif, Absobphon of). When water is saturated with
air at any temperature below 30^ C, lOOvolnmes of the dissolved air contain 34*19 vols.
of oi^gen and 65*09 yoIb, of nitrogen, whilst the nndissolvedair contains 21*1 per cent.
of oxygen and 78'9 per cent of nitrogen. Were the air a chemical combination of
oorraen and nitrogen, sneh a separation by solution would be impossible.

l%e other constituents of the atmosphere, viz. the aqueous vapour, carbonic acid,
ammonia, and decomposing organic matter, alter in amount at various times and in
different places, much more considerably than the oxygen and nitrogen.

The humidity of the air is affected by many circumstanees, such as temperature,
distance firom masses of watsr, and configuration of the land over which it lies. The
amount of aqueous vapour which any volume of air can take u^ depends entirely upon
the temperature of the air, and is represented by the tension and correspon^ng
density of t^e vapour of water in vacuo for that temperature ; thus at 10^ C. the
tension of aqueous vapour is 9*47 mm. of mercury, and the corresponding density
0*00000974, or 1 cubic metre of air at 10^ C. is saturated when it contains 9*74 grms.
of water in the form of vapour. It seldom happens, however, that the air contains its
satorating quantity of moisture, and the amount varies extremely with the corditions
before mentioned; thus, on the coast of the Bed Sea, during a simoon, the air was
found to contain only ^ part of the aqueous vapour required to saturate it, whilst in
our moist dimate, the air is often satmrated with watery vapour. The following table
shows the relative humidity, t. e, the existing percentage on the saturating quantity,
as ibnnd by Kamts in Halle, as a mean of sev^al years' observations :

Jaa.

Feb.

March.

ApiIL

Mv.

Jana

Julj.

Aug.

Sept.

Oct.

Not.

Dec.

850

76-4

71*4

69*1

69^

66-5

61*0

TS-S

78i>

86-3

Heikce we see that in Halle the air is most humid in December and driest in
AngusL

The determination of the aqueous vapour contained in the atmorohere may be
made, either by leading a known volume of air through weighed tubes containing
some hygroeoopic substance, as sulphuric acid or chloride of calcium, or by means
of hygrometers of various construction, for the description of which the article
HvaBOMBTBT must be consulted.

The carbonic acid or anhydride contained in the air varies also considerably in
amount, though by no means to so large an extent as the aqueous vapour. Many methods
are employed for ascertaining the quantity of carbonic acid present in the atmosphere.
The most certain method is to absorb the carbonic acid from a known volume of air by
passing the air, freed from aqueous vapour and ammonia, through weighed tubes con-
taining caustic potash. Saussure (Pogg. Ann. xix. 391), Brunner (Pogg. Ann.
xxiv. p. 669X Pettenkofer (Chem. Soc Qu. J. x. p. 292), Smith (Chem. Soc. Qu.
J. zi. p. 196), and Frankland (Chem. Soc. Qu. J.xiii. 27), have all proposed different
methods, for the explanation of which we must refer to the original papers.

From very numerous observations made by Saussure, Brunner, Lewy, and others, it
appears that air in the open country contains quantities of carbonic acid varying from
8 to 10 volumes in 10,000 of air. As an average number, it has been found that
4 vols, in 10,000 represent the usual composition of the air as regards carbonic acid.
In some few peculiar cases, a much larger proportion of carbonic acid has been found
(as noticed by Lewy in S. America at B^ota) ; but these abnormal results are ex-
gained by locU circumstances, as neighbouring volcanic emanations or burning forests.
The air collected above the ocean showed a small variation in carbonic acid between
day and night; that collected in the day contained 5*4, whilst that collected during
the night contained 3*3 carbonic add in 10,000 volumes of air. I^is observation is
easily accounted for by the increase of the coefficients of absorption with the diminution
of temperature occurring during the night. Air above the land also slightly changes
its amount of carbonic acid at various seasons of the year and times of the day, in
dependence upon different meteorological alterations, but as yet experiment has not
decided the nature of this dependence. At a certain elevation above the earth's sur-
face, the air, according to Saussure and Schlagentweit^ contains more carbonic acid than

FF 3

438 ATMOSPHERE.

18 found in tbe lover belts of the atmosphere; this inereasef ▼hich hovmer it
not laige, probably arises from the decrease of regetation in the higher atmospkerie
regions. In the air of crowded towns or of closed inhabited spaees (sndi as dweUing-
rooms, &e.), the carbonic add often rises to ten times the nonnal quantity, owing to in-
efficient Tentilation.

Although the relative amount of 4 toIs. of carbonic acid in 10,000 Tolt. of air ap-
pears to £b a yery small one, yet the absolute quantity of carbon thus oontainedintbe
atmosphere is yeiy large, exoMdine indeed all that is contained on the earth's nixfhee ia
the solid form, in the bodies of p&nts and animals, and that found under' the earth's
solid crust in the eoal formations. The question of change in the compoeition of the
earth's atmosphere as regards carbonic acid is one of Tital interest to all fbnie of
terrestrial life : for whilst forming the staple nutriment of the regetable woild, el^
bonic acid, when present in certain quantities, acts as a violent poison on the la^
orders of animal life ; nor is the limit at which this gas begins to be hortfiil to the
animal, veiy far remoyed from the quantity which at^reaent exists in the atBM>-
sphere : for we find that Leblanc and ±*^et assigpi a linut of fiye in 1000 (tea timei
the normal quantity), whilst Reid and Amott give a much lower limit to the non-
injurious effect of tins gas. Whether the atmosphere is now slowly undeigmQ^ or
has in past ages undergone, any perc»tible change in the amount of its oarb(mie add,
is a question to which, owing to the absence of certain and accurate data, wean as yet
unable to give any very satisfactory answer. We do, however, know that there are a
great number of causes continually at work, some of which tend to increase the amomt
of atmospheric carbonic acid, whilst there are othos which tend to effeet adiminatioB
in this constituent Whether the resultant of these various counteracting inflnniMwi is
such as to keep, during future a^ee, the carbonic acid exactly at the present amoimt, it
is, with our present knowledge, impossible to say ; but from the remaiks whidi foDoT,
it will be seen that if any alteration occur, it must proceed witii extreme alownesB.

The principal causes which tend to increase the atmospberic carbonic add aie:
(1) The respiration of animals. (2) Combustion of vegetable carbonised materiiL
(3) ExhiUations of carbonic acid caused by volcanic apd other intra-tenestml
agencies. It would appear that the quantitr^ of carbonic acid escaping from Tolesoie
vents, mineral springs, and other inorgamc sources into the atmosphefe is maeh
larger than that produced by the two causes first named. According to the cakolt-
tions of Poggendorff (naturally but veiy rude approximations to the truth), it seems
that, taking the amount of carbonic acid evolved by volcanic action to be ten times
larger than that given off by every kind of combustion of carbonised material, the
quantity of carbonic acid at present contained in the atmosphere would be donUed in
886 years, supposing, of course, that no causes of diminution of were acting. That
such causes of diminution are, however, continually at work we know. TheyocamA
mainly in (1) the decomposition of carbonic acid, t. e. reduction of carbon and regeaeit-
tion of oxygen, which living vegetables effect in sunlight (2) The fixation of carbooie
acid as carboiuito of lime bv the vital action of certain animalcule, giving rise to
coral reefii and islands, and the whole of the vast limestone deposits. (S) T^
fixation of carbonic acid by inorganic chemical processes.

The immense extent to which these actions, particularly the second <me^ ban gone
and are still goin^ on, appears to justify tiie opinion that if any change in the amoont
of the atmospheric carbonic acid occur at all, it is more probably a diminntioa thaa
an increase. Any conclusions which we can draw from geological fiicts, seem n&er to
support this opimon : for it is more likely that the air contained a htiget amoant of
carbonic acid during the deposition of the enormous carboniferous system when the
ve^ietation must have been so luxuriant and proftise, and when few, if any, air-breathing
animals existed, than less than at present StOl, we have no right positivet^ to
assume that the air at the time of the deposition of the coal and limestone contained
more carbonic acid than now : for we know nothing of the length of time during vineh
these formations were in progress.

From the foregoing remaifs, it is seen that a continual circulation of the atmospberic
carbon takes place ; the animal gives off the waste portion of its body mainly as ea^
bonic add, and thus deteriorates the atmosphere, windi would soon become unfit for
his farther use, if the vegeteble world did not absorb the poisonous gaa^ at onee
retaining the carbon in the solid form, fit for the subsequent nourishment of the aaimi],
and exhaling the oxygen wherewith the higher organism again removes his spent
materials.

Haying described the causes effecting possible variation of the atmospheric cabonk
acid, it is almost needless to consider any change which the oxygen may undergo, for
the atmosphere becomes unfit for the sustenance of animal life from the presence of a
small quantity of carbonic acid, long before the oxygen is materially diminished. K
however, the carbonic acid is slowly decreasing, it may be interesting to inquire hov

ATMOSPHERE. 439

long oar wapfAj of oo^gen iriU last us. Saehaspeealatioaliss been answered, as satis-
fatSanlj as uie etzeamstanees admit o^ by Dumas and Bonssmganlt These chemists
calfolated that if the irhole of the earth's atmosphere were pat into a balloon and sus-
pended from one end of a balance, it would require 681,000 cubes of copper, each having
aside of 1 kilometre (1093 English yards) in length, to be suspended at the other end
to eqaalise the balance. Of this total weighty the oxygen would be represented by
1S4,000 eobes. Auoming, from the best data, that a man consumes a kilogramme of
oxygen per day, taking the population of the earth to be 1000 millions, and supposing
that the oxygen taken up by animals and by pntrefaetive processes is four times as large
as that consumed by human beings, and supposing further, that the oxygen given off
by plants only covers the ei^nditare of oxygen effected bv other causes not mentioned,
it appears, even in this exaggerated case, that an amount of oxygen three times as large
as tibat consumed in one centoiy by the whole nimiber of sniinals existing on the earUi,
is renresented by 15 or 16 of the copp» cubes, each having a side of 1 kilometre in
lengui, or the alteration effected in a century is less than ^^ of the total quantity of oxv-
gen, and is therefore altogether inappreciable by our most exact determinative methods.
(See Dumas and Boussingault (1841) Ann. Ch. Phys. [3] iil 257, 288.)

As zagards the ammonia and the organic impurities contained in the atmo-
sphere we stin labour under the disadvantage of insufficient experimental data. The
great difficalty in the estimation of these constituents, lies in the very minute quantities
which are contained in the atmoRthere. This difficulty is seen when we ooiapare some
of the statements put fbrward of taa amount of atmospheric ammonia ; thus Horsford
(Ann. Ch. Fharm. Ixxiv. 243), found in 1 million parts of air, 47*6 parts of ammonia,
whilat Bineau (Ann. Ch. Phys. xlii p. 462) Ibund in the same quantity of air, firom
CK)4 to 0*1 part of ammonia. Between these extremes, we have numerous experiments
in which every variation in the quantity of atmospheric ammonia has been found. Al-
though, firom the great differences in the numerical results (maximum 135 ; minimum
0*1 parts of carbonate of ammonia),* probably arising, partly £rom errors of analysis and
parUy from real variations in the contained quantity, it is impossible to fix upon any
number as ^ving the average composition, still it is certain that the atmosphere
ahrays eontiuns ammoniacal salts, and that rain (the first portions more than the latter
portions^ hail, snow, and dew, all contain appreciable quantities of ammonia.

The atmospheric ammonia plays a very important part in vegetation : for it is mainly
If Aot altogether, from the ammoniacal salts contained in the air, that plants obtain
the nitrogen which thev require for the formation of seed and other essential parts of
their struetora Whether plants are at all able to asomilate the free nitrogen of the
atmosphere, must^ in spite of the numerous researches on the subject, be considered
doubtfuL George Ville has £>r some time asserted, founding his assertion on a large
number of elaborate experiments, that plants can absorb and assimilate the free atmo-
spheric nitrogen. Boussingault, on the contrary, froln his own extensive investigations,
deniet Yille's condosions, affirming that it is from nitrogenous compounds alone that
{dants can assimilate the nitrogen. The commission of the French Academy, which
was deputed to examine the question imder the direction of Chevreul, reported in
Yille's &vour, althoogh some doubt as to the estimation of the ammonia contained in
the distilled water ui^d, was expressed. Still more lately IJawes, Gilbert, and Pugb,
have investigated the subject with great care, and find that plants growing in an
atmosphere and on a soil free from ammonia or combined nitrogen in other forms,
do not contain more nitrogen than the seeds from which ihey grow. In the state of
uncertainty in which such contradictory statements leave us, we mav, however, be certain
of one &ct in which all the esroeriments agree, namely, that whether or not plants can
assimilate small quantities of free nitrogen, it appears that plants growing in air
perfectly free from ammonia, do not flourish to anything like the same extent as plants
living in an ammoniacal atmosphereL

Concerning the remaining constitnente, and especially the organic putrescent matters,
our present knowledge is eren less satisfactory or positive than is the case with the
ammonia. Within a very recent period, we were unacquainted with any method for
determining the presence of organic putrescent matters ; and even the very important
and ingenious method lately proposed by Dr. B. Angus Smith (Chem. Soa Qu. J.
xL p. 196) requires much extension and general application before we can arrive at
a knowledge of the exact qualitative distribution of the organic impurities. Smith's
method (for the details of which we must refer to the paper), depends upon the
reducing action which solid, liquid or gaseous organic putrescent matter effects on per-
manganate of potassium. The strength of the test-solution is determined by adding
it to a solution of sugar of known composition, until the colour of the permanganate
i«mains permanent ; and the same reaction performed with the air xmder examination,
ahowB the quantity of contained ozganic matter. In this way, Smith has detected great

FF 4

440 ATOMIC VOLXJME.

differences between the air of various localities. The air firom high conntzy ground
was found to contain 1 grain of organic matter in 200,000 cubic inches of air, whilst
the air tcom a cesspool contained the same quantity of organic matter in 60 cubic
inches of air. In a sanitaiy, as well as in a purely scientific point of view, it is diffi-
cult to over-estimate the importance of this simple method for determining the ozganie
impurities which air contains ; and if future research confirm its appli»bility to all
cases, it will prove an invaluable instrument in the hands of the physieian and the
sanitary reformer.

Besides the constituents already mentioned, air contains minute quantities of
nitrates, hydrocarbons, sulphurous and sulphuric acids, and according to some
chemists, 'iodine, but this has been lately demed. Ozone also occurs in the atmo-
sphere in veiT small amounts, varying, however, extremely with the situation and
meteorological conditions of the place. (See Ozomt.)

The atmosphere of the ocean, as well as of the masses of firesh water ooeniring on
the earth's surface, is subject to the same changes from the existence of animal and
vegetable life, as the earth's gaseous atmosphere. The relative proportion between the
gases dissolved in the water is fixed in accordance with the law of absorption, and
many important and interesting conclusions, such as the relative increase of dissolved
oxygen, or diminution of temperature, enabling Mammalia to live in the polar bat not
in the tropical seas, can be drawn from an application of these laws to the atmosphere
of the sea. The equilibrium between the constituents of the dissolved atmo^here
kept up by animal and vegetable life, is well illustrated by the vivaria now so eommon,
which were first introduced by Mr. Warington.

The air of towns and dose-inhabited spaces, becomes, as has been stated, often
overcharged with carbonic acid and other impurities^ The amount of carbonic add
present in dwelling-rooms, &c., has been made the subject of experiment byLeblanc
(Ann. Ch. Phys. [3] v. 223; xxvii 373), Pettenkofer (Chem. Soe. Qu. J. x. 292);
Boscoe (Chem. Soc. Qu. J. x.) ; and Smith (Chem. Soc. Qu. J. xi 196). The main
results maybe stated to be : (1) that in rooms which are not thoroughly ventilated, the
amount of carbonic acid may rise from 1 to 7 volumes in 1000 of air ; (2) that in well
ventilated rooms, the amount of carbonic acid should not rise above 0*8 in lOOO;
(3) that in ordinary dwellings, or even in school- or barrack-rooms, the carbonic acid is
difihsed uniformly throughout the space, in whatever parts of the room the exit for
deteriorated aij* is placed, though in the exaggerated case of crowded theatres, the
air at the highest part of the bmlding was found to contain more carbonic add than
the air at the level of the stage. For other interesting details, we must refer to the
original papers, or to the artide on VENnLAiioN. H. £. B.

ATOMXO VO&VMB. 8pec^ tft^ume; Equiwdmt volume; Molecular f»lume.
-^ The atomic or specific volume of a bodv is the space occupied by a quantity of
it proportional to its atomic weight, and is therefore expressed by the quotient of the
atomio weight divided by the weight of a unit-volume, t^at is by the spedfle grarity :

... , atomic weight

Atomic volume = r- :h__

specific gravity

It must not, however be supposed that the atomio volumes represent the relative
volumes of the actual material atoms of different bodies. For, regarding any sub-
stance, soUd, liquid, or gaseous, as an aggregate of material partides capable of
moving amongst themselves, it is impossible to suppose these paitides to be in actual
contact and to fill up the entire volume of the body ; we must suppose them to be
separated by certain intervals : consequently the specific gravity, and therefore also
the specific volume of the body, will depend, partly on the relative weights of these
atoms, partly on the number of them contained in a given space, and therefore on the
magnitude of the interstitial spaces. Unless, therefore, the spaces are dther infinitely
small in comparison with the magnitude of the atoms themsdves, or bear the same
proportion thereto in all bodies, it is impossible to determine the relative volumes of
the actual material atoms: for we have no means of ascertaining the proportion
between the size of the atoms and of the intervening spaces in each particular case.
The atomic volume of bodies must therefore be imderstood, as the spaces occupied by
aggregates of atoms (induding the interstitial spaces), whose weights are proportional
to the atomic weights of the bodies.

As the atomic weights, or multiples thereof represent the proportions in which

bodies combine by weight, so likewise do the atomic volumes or multiples thez«of

indicate the proportions in which they imite by volume, thus : the atomic volume of

127 108

iodine being -^z = 257, and that of silver « r/w = 10'2, wo infer that 257 vola.

iodine unite with 10*2 vols, silver to form iodide of silver, Agl.

ATOMIC VOLUME. 441

The nnmbera repreflenting the atomic Tolmnes of bodies Taiy according to the units
of atomic weight and specific gravity chosen, and accoiding to the particular values
asaignad to the atomic weights. Thus, if the atomic weight of hydrogen be equal to 1,
that of chlorine » 85*5, and of sulphur » 32, the atomic weiffht of hydrochloric acid
(HCl) will be 36*5, and that of sulphydric acid (H^) « 34. Now the specific gravity
of hydrochloric acid gas referred to air as unity is 1*264, and that of sulphydric acid
is 1*177. Henee we have :

Atomic volume of HCl » - ^^. — 14'44

1-264

H«S ■- -?i— . 14'44

n » XL o = 1 'ITT

It on the other hand, we adopt hydrogen as the standard of specific gravily for gases,

that of hydrochloric acid is 18*25, and that of sulphydric acid is 17, in each case

half the atomic weiehtk On this hypothesis, therefore, the atomic volumes of both

gases are enressed by the number 2. Again, if common ether be represented by the

fonnuU OH^H) [C = 12, H » 1, O » 16], its atomic weight is 74; and, its specific

gravity in the gaseous state being 37 (referred to hydrogen), its atomic volume in

74
that state is -^ « 2, and in the liquid state (specific gravity at 0^ referred to water),

74
its atomic volume is --_ » 100*41. But if ether be represented by the formula

OB*0 [C » 6, i7 » 1, 0 a 8], then its atomic volume in the gaseous state will be

87 37

^ ■• 1, and in the liquid state ^-^^ — 60*206. The atomic volumes of gases and

vi^wurs are calculated from the specific gravities referred either to hydrogen or to
atmospheric air ; those of solids and liquids from the specific gravities referred to water
as unity.

Atomic Volumes of Gases.

According to the system of atomic weights adopted in this work, equal volumes of
different elementary gases are supposed to contain, for the most part, equal numbers
of atoms of their respective elements, so that the atomic weight of each body in the
gaseous state is tiie weight of a volume of the gas equal to that of a quantity of hydro-
gen whose weight is taken as unity; in other words, the atomic weights of the simple
gases are expreraed by the same numbers as their specific gravities referred to hydro-
gen as unity. This is sometimes expressed by saying that an atom of each elementary
gas occupies one volume. The only exceptions to this law are presented by phosphorus
and arsenic, whose densities in the gaseous state are double of what they snonld be if
they followed the law ; and by selenium and tellurium, whose vapour-densities have not
yet been ascertained with certainty. Sulphur-vapour was formerly supposed to have
a density three times as great as that which the general law just stated requires, but
recent experiments have shown that it conforms to the general law.

The atoms or molecules of compound bodies in the gaseous state occupy, for the
most part, iwics the volume of an atom of hydrogen or other simple gas ; in other
worda, the number of molecules of a compound gas contained in a given space is half
the number of atoms of hydrogen which would be included in that same space. Con-
sequently, the specific gravity of a oompoimd gas or vapour referred to hydrogen as
unity is equal to half uie atomic weight Thus, the atomic weight of hydrochloric
add (HCl) is 36*5, and its specific gravity refened to hydrogen is 18*25 ; the atomic
weight of ammonia (NH*) is 17, and its specific gravity referred to hydiogen is 8*5.
(For the further development of this law, and for certain exceptions to i^ real and
apparent, see the article Atomic Wbights.)

The mode of stating these laws of gaseous atomic volume, must of course be modified
according to the system of atomic weights chosen. On that which has hitherto been
roost generally adopted {H » 1, 0 » 8, iS c= 16, &c), some of the elementary gases,
viz. chlorine, iodine, bromine, nitrogen, and mercury are supposed to have atomic
volumes eqiuJ to that of hydrogen, while oxygen, sulphur, pnosphorus, and arsenic
have atomic volumes only haJf as great. The former are generally called ttco-volume
eases, and the latter one-volume gases, the volume of oxygen being taken as the imit.
On the same system, the molecules of most compound bcKues in the gaseous state are
said to oceapjfour volumes.

442

ATOMIC VOLUME.

AtonUo Volumes ofldquids and SoUda.

1. Of StommtaiT Bodies. The following table oontBuis die atomic Tolnmes of
those solid and liqTiid dements whose densities haTO been determined with aceoxuy.
The nnmbers in the third column are the quotients of the atomic weights divided bj the
specific giaTities xeferred to water as nnitj :

Sabttiaoe.

Alnmininm

Antimony

Arsenic .

Bismuth

Bromine

Cadmium

Calcinm

Carbon .

Chlorine

Chrominm

Cobalt .

Copper .

Glucinnm

Gold .

Iodine .

Iridium .

Iron

Lead

Lithium

Magnesium

Manganese

Mercurv

Molybdenum

Nickel .

Palladium

Phosphorus

Platinum

Potassium

Rhodium

Selenium

Silicon .
Silver .
Sodium .
Strontium

Sulphur

Tellurium

Tin

Tungsten

Uranium

Zinc

Alonte
weight.

Atomic
Tolume.

120*3

76
210

35-5
26-2
29-6
31-7
47
196

127

103-6
7

27-6
100

29-5

39*2

28
108
23
43*8

128
118

32-5

5*3

17-9

18*3

21*2

25*8

6*5

12*6

8-4

5*2

26-7

3*8

3-5

3*6

2-2

10-2

25*7
4*5
3-6
9-2

11-9
6-9
3*5
7-4
5-3
3*4
4*6

;i6-8

[15*8

4*6

45-6

4*7

[18-4

[l6*4

11*2

10*2

23*7

17-2

(15*2

[16*2

20*6

16*2

5*3

3*8

4*6

SpedSc gnvitj (water a 1).

2*5— 2*67, Wohler; 2*67, Deville.

6*72, Mazehai\d and Sdieerer; Koppi.

5*63, Kamten; 5^7, Hen^yath.

9*80, Maichand and Scheenr ; 9*78, Eopp.

lAqvid: 319, Pierre; 2*99, Lowig.

6*69, Stromeyer ; 8*45, 'Ksfpj^

1*58, Bunsen.

Diamond: 3*52, Biiason.

Graphite: 2*32, Karsten; 2*27, Bcgpault

Liquid: 1*33, Faraday.

7*01, Bunsen and Frankhmd.

8*49, Brunner ; 8*51, Berzelius.

8*95, Marchand and Scheerer ; 8*93, Kopp^

2*1, Defarvr.

19*34, a Hose; 19*26, Brisnon.

4*95, Gay-Lussac.

21*80, Mare.

7-84, Broling; 7*79, Eaisten

11*39, Karsten; 11*33, Kopp.

0*59, Bunsen.

1*74, Bunsen ; 1*70. Sjoro.

8*03, Bachmann; 8*01, John.

Liquid : 13*60, Begnaalt» Eopp.

8-62—^*64, Buchhola.

8*60, Brunner; 8*82^ Tiippati.

11*80, WoUaston.

YeOaw: 1*84, Schrotter; 1*83, Kopp.

Red: 1*96, Schrotter.

21*5, WoUaston, Berselius.

0*86, Qay-Lussac and Thenaid.

11*0, WoUaston; 11*2, Cloud.

Amorphous: 4*28, Schaf^tsch.

Granular : 4*80, Scha&otach.

Graphitcidal: 2*49,Wohler.

10*4, Karsten, 10*57, O. Bose.

0*97, Gkiy-Lussac and Theoard.

2*54, Bunsen.

IVimetric : 2*07, Marchand and Scheerer, Koj^

Monodinic: 1*98, Marchand and Sdieers'.

6*24, Berzelius ; 6*18, Lowe.

7*29, Kaisten; 7*30, Kopp.

17-2, AUen and Aiken; 17'5— 18*3, WoUei:

18*4, P^ligot.

713, Kopp; 7-1— 7-2, BoUey.

The numbers in the third oolumn of this table, do not exhibit the simplicity of re-
lation which exists between the atomic volumes of gaseous bodies. Thero are, indeed,
several causes which interfere with the existence, or at least with the observ^itioo, of
such simple relations between the atomic volumes of soUd and liquid elements. Id
the first place, the densities of three of them, viz. mercury, bromine, and chlorine, are
such as belong to them in the liquid state, whereas the densities assigned to all tie
others have been determined in the soUd state. In soUds, moreover, the density is
greatiy affected by the state of aggregation, whether crystalline or amorphous, and in
dimorphous bodies^ each form has a density peculiar to itself. Further, as solids and

ATOMIC VOLUME.

443

Hqoids are ytaiaaafy affected by heat, each having a peenliar rate of ezpanrion, and
that rate being different at different tempeiataree, it is not to be expected that their
atomic Tolumes should exhibit simple relations, iinless thej are compared at tempe-
fatores at which th^ are similarly afibcted by heat Bren gases are found to exhibit
abnofmal atomic Tolnmes if compared at temperatnres too near the points at irhidi
thej pass into the liquid state. In liquids, the simplest relations of atomic Tolume are
louna at thoee temperatures for wlntk the tensions of the vapours are equal (Kopp) ;
uad in solids^ the melting points are most probably the comparable temperatures.
Nov the specific grayities of most of the solid elements in the preceding table, haye
been determined at mean temperatures (as at \6°'6 C), which, in the case of potassium,
sodium, phosphorus, and a row others, do not diffsr greatly &om the melting points,
but in otner cases^ as with sold, platinum, iron, &c., are removed from the melting
points by rerj long interrab. In spite, however, of these causes of divergence^ the
atomic Tolumes of certain analogous elements are yeiy nearly equal to eadi other : viz.
those of selenium and enlnhnr; of chromium, iron, cobalt, copper, manganese and
nickel ; of molybdenum aad tungsten ; of iridium, [ilatinum, palladium and rhodium;
and of gold and silver.

2. •rSAjiviaOAiBpowidi* The relations between the atomic volumes of liquids,
have been investigated chiefly by H. Kopp (Ann. Ch. Pharm. xcvi. 153, 303, c 19).
The atomic volumes of Hquids, as already observed, are comparable only at temperatores
for which the tensions of their vapours are equal, as at the boiling points. If the
atomic weights are coumared with the densitiaB at ecjual temperatures, no regular re-
lations can be perceived ; but when the same comparison is made at the boiUuff points
of the respeetiye liquids, several remarkable laws become apparent. The density of a
liquid at its boiling point cannot be asoertained by direct experiment ; but when the
density at any one point, say at 16'S9 C, has been ascertained, and the rate at ex-
pansion is also known, the density at the boiling point may be calculated. (See
£xPAiiSHur.)

Table A. contains Eopp's determinations of the atomic volumes of several liquids
containing carbon, hydrogen, and os^gen, at their boiling points. The atomic weights
are those of the hydrogen scale. The c€tlculated atomic yolumes in the fourth column
are determined by a method to be presently described ; the observed atomic yolumes
are the quotients of the atomic weights divided by the i^^edfic gravities at the boiling
zefsrred to water as unity.

Tablb a.
Aiowtie Vclumea of Ligmds containing Carbon, Hydrogen, and Oxygen,

Atomic Volume at the BoIIIdr Point.

Sabttumu

Formula.

Atomla
Weight.

Calculated.

ObMTTed.

irBensene ....

era*

99-0

960... 99-7 at 80° C.

Ojrmene ....

Naphthalin

Aldehyde . . • .

C»*H»*

134

187-0

188-6...185-2 „ 176

C"H»

128

164-0

149-2 . . „ 218

C«H*0«

66*2

660... 66-9 „ 21

Valeraldehyde

C»H"0«

122-2

117-8...120-3 „ 101

?•

Bitter almond oil .

cna«o

106

122-2

118-4 . . „ 179

Cnminol

C"H«0

148

188-2

189-2 . . „ 236

Tetrvl ....

C»H»«

114

187-0

184-6...186-8 „ 108

vAcetone.

cmK>

78-2

77-8... 77-6 „ 66

'Water ....

RM^

18-8

18-8 . . „ 100

Wood-spirit .

CH<0

40-8

41-9... 42-2 „ 69

Akohol ....

0«H«0

62-8

61-8... 62-6 „ 78

AmyUc alcohol

C»H»K)

128-8

128-6...124-4 „ 136

Phenylie alcohol .

C^«0

106-8

108-6...104-0 „ 194

BensyHe alcohol

C»H"0

108

128*8

123-7 . . „ 213

Formic add .

0H«0»

420

40-9... 41-8 „ 99

?•

Acetic acid

C«H*0«

64-0

63-6... 63-8 „ 118

Pkopionic add

C»HH)«

86-0

86-4 . . „ 137

Butyric add .

C«HK)«

1080

106-4...107-8 „ 166

Talenamc and

0»H"0*

102

1800

130-2...131-2 „ 176

JBeoaoieadd •

C»H«0«

122

1800

126-9 . . „ 263

444

ATOMIC VOLUME.

Tablb a (continued).

Atomic Volame at the Boiling Pobt.

Substance.

Formula.

Atomic
Weight.

CalcuUted.

ObMrred.

T.t,hylic ether .

C^H^O

106*8

106-6... 106-4 at 84«>C.

Acetic anhydride .

C*H«0»

102

109-2

109-9...1101 „ 138

Formate of methyl

C«H<0«

64-0

63*4 . . „ 36

Acetate of methyl .
Formate of ethyl .

C»H«0«

86-0

83*7... 86-8 „ 65

C«HW

860

84-9... 857 „ 66

Acetate of ethyl

C*H«0«

108-0

107-4...107-8 „ 74

Butyrate of methyl

C*H"0«

102

1800

126-7...127S „ 93

Propionate of ethyl

C»H"0«

102

130-0

126-8 . . „ 93

Valerate of methyl .
Butyrate of ethyl .
Acetate of telzyl .

C«H"0*

116

1620

148-7... 149*6 „ 112

0«H"0»

116

1620

1491...149-4 „ 112

C«H»K)«

116

162-0

149-3 . . „ 112

Formate of amyl .

C«B[>«0*

116

1620

149-4...160-2 „ 112

Valerate of ethyl .
Acetate of amyl

C»H»*0«

130

174-0

173-6...173-6 „ 131

C*H"0«

130

174-0

173-3... 176-6 „ 131

Valerate of amyl .

C»«H»0*

172

2400

2441 . . ,,188

Benzoate of methyl

C«H«0«

136

162-0

148-6...160-3 „ 190

Benzoate of ethyl .

C»H"0*

150

1740

172-4...174-8 „ 209

Benzoate of amyl .

C"H"0«

192

2400

247-7 . . „ 266

^Cinnamate of ethyl

C"H'K)«

176

207-0

211-3 . . ,,260

''Add salicylate of methyl

U«H«0«

162

169-8

166-2...1670 „ 223

Carbonate of ethyl .

C*H'«0«

118

187*8

138-8...139-4 „ 126

Oxalate of methyl .

0*H»0*

118

1170

116-3 . . „ 162

e«

Oxalate of ethyl .

0«H'»0«

146

161-0

166-8...167-1 „ 186

Succinate of ethyl .

g»h:"o*

174

2060

2090 . . „ 217

A comparison of the numbers in this table, leads to the following results : —

1. Differences of atomic volume are in numerous instances proportional to the iif-
ferences between the corresponding chemical formuUB. — Thus, liquids whose formnis
differ by n . GH*, differ in atomic yolume by n . 22 ; for example, the atomic yolumes of
formate of methyl, C«H*0«, and butyrate of ethyl, C«HH)*, differ by nearly 4 x 22.
Acetate of ethyl, C^HW, and butyrate of methyl, C*H"0*. whose formule diflfer l^
CH*, differ in atomic yolume by nearly 22. The same law holds good with respect to
liquids containing sulphur, chlorine, iodine, bromine, and nitrogen (see Tables B, C,
D). Again, by comparing the atomic yolumes of analogous chlorine and bromine
compounds, it is found that the substitution of 1, 2, or 3 atoms of bromine ibr an
equiyalont quantity of chlorine, increases the atomic yolume of a compound by ODoe,
twice, or three times 6. This will be seen by comparing the atomic yolumes of PBi*
andPCl'; (?H»BrandC«H*Cl,&c (Table 0.)

2. Isomeric liquids beUmging to the same ehemieal type have equal atomic volutiuM. —
The atomic yolume of acetic acid, j^ | O is between 63-6 and 63-8 ; that of

formate of methyl, rm^ [ 0 is 63*4 ; the atomic yolume of butyric acid, ^ [ 0 ti

between 106-4 and 107'8; that of acetate of ethyl, ^^^lO is betwisen 107*4 and
107-8. , . . .

3. In liquids of the same chemical type, the replacement of hydrogen by an equitfolfnt
quantity of oxygen (that is to say, of 1 pt of hydrogen by 8 pts of oxygen), maJket but
a slight alteration in the atomic volume,^T)i\B may be. seen by comparing the atomic
yolumes of alcohol, C*H«0, and acetic acid, C«H*0* ; of ether, C*H"0, acetate of ethyl,

rid, OH«0» ; of cymene, C"H'*, and cuminol, C»H«0.

C^H^O*, and anhydrous acetic acid.

The alteration caused by the substitution of O for H* is always an increase.

4. In liquids of the same chemical type, the replacement of 2 at,'K by \ at C {\ -^
by weight of hydrogen by 6 parts of carbon) maies no alteration in the atomie tolvme.
— Such, for example, is the case with benzoate of ethyl, C*H**0', and ysderate of
ethyl, C'H'^O', and with the corresponding benzoatoi and yalcrates in gen«nl; abo

ATOMIC VOLUME. 445

with bitter-almond oil, CHH), and valeraldehyde, C*H*H) ; alao with phenylic
alcohol, C"H«0. and Tinic ether, C^»»0.

In liqnidfl belonging to different t^pes, the same relations are not found to hold
good. MoreoTer, the types within which these relations are observed, are precisely
those of Qerhazdt's dassifieaiion (see CLA88xncA,TioN). Further, when liquid com-
pounds are represented by rational fonnuls founded on these types, their atomic
Tohounes may be calculated from certain fimdamental values of the atomic Tolumes of
the elements, on the supposition that the atomic volume of a liquid com^und is equi|l
to the sum of the atomic volumes of its constituent elements. In Uus manner the
eakolated atomic volumes in the fourth columns of tables A, B, C, D are determined.
It must be understood however that these values are based upon somewhat doubtM
assumptions respecting the atomic Tolumes of the elements, and are regarded by Kopp
merely as approximations to the truth.

Since the addition of 'CH* to a compound increases the atomic yolume by 22, this

number may be taken to represent the atomic Tolume of C&' ; moreover, since C

may take the place of H' in combination, without altering the atomic volume of the

oompomid, it follows that the atomic Tolume of C must be equal to that of H' ; and

22
therefore the atomic Tolume of C ■■ -^ » 11, and that of H* also equal to 11, or that

of H a 6'6, Further, as the substitution of O for H* produces a slight increase in
the atomic volume of a compound, the atomic volume of 0 must be rather greater
than II ; and it is foxmd that» by assuming the atomic volume of O, when it takes
place of H* (that is to say, in a radide, as when acetyl, CH'O, is formed from ethyl,
Cn3*\ to be equal to 12*2, results are obtained agreeing very nearly with those of

observation. But when oxygen occupies the position which it has* in water, ^O, its

atomic volume is smaller. The specific gravity of water at the boiling point is

18
0-9679 ; hence its atomic volume at that temperature is • ' ■« 18*8 ; now the

2 atoms of hydrogen occupy a space equal to 11 ; hence the volume of the oxygen
is 7*8. The same valve of the atomic volume substituted for 0 la the formula of the
several compounds belonging to the water-type, in which it occupies a similar place,
that is to say, outside tne radicle, gives results agreeing nearly with observation.
That a given quantity of a substance should occupy different spaces, under different
ciivnmstances, is a fact easily explained, when it is remembered that the particles of
a body cannot be supposed to be in absolute contact, but are separated by certain
spaces, which, increase or .diminish according to the temperature of the body, and
aooording as it is in the solid, liquid, or gaseous state.

From these values of the atomic volumes of the elements, carbon, hydrogen, and
ozjgen; viz.

Atomic volume of C » 11

.. H ^6-6

„ „ O (within the radicle) . . . . -■ 12*2

„ „ O (without the radicle) . . . . » 7*8

the calculated values of the atomic volumes of liquids, in the fourth column of Table
A are deduced. The method of calculation may be understood from the following
examples:

Benzene, CfH* = C?H» H.

Atomic volume of C » 66

„ H« * ^

„ „ benzene a 99

Aldehyde, C?H«0 - C«H«O.H.

Atomic volume of C 8-22

„ H* - 22

„ „ 0 (within the radicle) . . . « 12*2

„ „ aldehyde « 66*2

Alcohol, (?E*0 = ^h|^-

Atomic volume of C » 22

H« -33

O (without the radicle) . . . « 7*8

alcohol » 62*8

»t II

»> II

n f>

446.

ATOMIC VOLUME.

Acetic acid, C«H*0 -c«^o|o-

Atomio Tolume of C*

H«

O (within the radicle)
O (without the radicb) .

aoetioadd

f»

- 22

- 12-2
« V^

- 64*0

Acetic anh^dMe (^H«0» - ^^|o.

Atomic volume of C^

ft
If

ff
ff
f»

O* (within the radicle^
0 (without the radide)

aoetio anhydride •

44
38

24-4
7-8

109-2

09alaUofnieikyl,OK*0' -(OTyl^

Atomic Tolnme of 0* . • •

ff H* . . . . .
„ „ 0* (within the radicle) •

o If O' (without the (radicle) .

oxalate of metiiyl •

- 44
-> 88

- 24-4
« 16-0

-117*0

lAqwidt eonUnwng Sui^kur, — Sul}>hur entos into combination in Tazioiu wayi ;
Bometimefl taking the place of oi^gen in the type HH.0 (aa in mercaptan) ; BometiBict
taking the place of carbon within a radicle (as in aulphuroiu anhyoride) 80.0, eoia-
parea with carbonic anhydride 00.0 ; sometimes replacing oxygen within a ndide (as
in sulphide of carbon), CS.S, compared with carbonic uihy£ide. In the first and
second cases^ the atomic Tolume of sulphur-compounds may be calculated by attri-
buting to snlphur, (S *■ 82), the atomic Tolume 22-6, those of the other elements re-
maining as aboTC ; in the third case, the atomic Tolume of sulphur appean to be
greater; Tix. 28-6.

-Rx.— Mercaptan, C?H«S «^*|s.

Suiphide of carbon, CSF - CaS.

Atomic volume of 0 . • ■■ 11

Atomic volume of 0* . . — 22

„ „ S (within the

„ „ H* . . » 33

radicle) . - 28*6

„ S . . - 22-6

„ „ S (without the

„ „ mercaptan . >■ 77*6

radicle) . - 2^

„ sulphide of carbon . » 62-2

Tablb B. — Atomic Vdumee cflAgynd Sv^hur^compomuU,

Sttbttanct.

Formula.

Atomic
Weight.

Atomic Volomo at the Boillnff Point.

Calculated.

Obteinped.

Mercaptan .
Amylio mercaptan .
Sulphide of methyl
Sulphide of ethyl .
Bisulphide of methyl
Sulphurous anhydride .
Sulphite of ethyl .
Sulphide of carbon

C«H«S

C»H"S

0«H«S

C*H»«S

C«H«S«

S0«
C*H»»SO*

CS«

62
104
62
90
94
64
138
76

77*6
143-6

77*6
121*6
100*2

42*6
149-4

62*2

760... 761 at 36oa
1401...140-5 „ 120

76-7 . . „ 41
120*5...121*6 „ 91
1O0-6...1007 „ 114

43-9 . . „ -8
148-8...149-6 „ 160

62-2... 62-4 „ 47

Chlorides, Bromides, and Iodides, — ^In liquid compounds of this daas^ the atomic
volume of 01 is supposed to be 22*8, that of Br « 27*8, and that of I » 37*6, tlioee of
the other elements remaining as above.

ATOMIC VOLUME.

447

Tabu C. — Atomk Volumes of Liquid Chhrides^ Bromides^ and Iodides.

A A M

Atoaate Volume at the Boiling Point.

Subatanccw

Formula.

Atomie
Weight.

Calculated.

Obaarred.

Diehloriiiated ethylene

CHKSP

78-6

79-9 . . at 87° C.

Chloride of carbon •

C«C1*

166

113-2

115-4 . . „ 123

CJhlnride of ethylene .
„ monochlorinated .

C«H*C1«

89-6

85-8... 86*4 „ 85

C«H«C1«

133-5

106-9

105-4...107-2 „ 115

„ diefalorinated

C*BPCl*

168

124-2

120-7... 121*4 „ 137

„ trichlorinated

CHCl*

202-5

141-5

143 . . „ 154

Chloride of tettrlene
HonoeUorinatea chloride

C*H"C1«

127

183-6

1295...138-7 „ 123

of methyl •

CH«C1«

67-6

64*5 . . „ 80-5

CHCI«

119-5

84-9

84*8... 85*7 „ 62

Gbloride of cazbon

ca*

154

102-2

104-3...107-0 „ 78

Chloride of ethyl

„ monochlorinated .

c«H»a

64-5

72-3

71-2... 74-5 „ 11

c«H*a«

99.

89-6

86-9... 89-9 „ 64

„ dichlorinated

c^»ci«

133-5

106-9

105-6...109-7 „ 75

Chloride of amyl

c»H»a

106-5

138*3

135-4...137-0 „ 102

Chloral ....

0»HC1»0

147-5

108-1

108-4...108-9 „ 96

Chloride of acetyl .

CHKKJl

78-5

73-5

74-4... 75-2 „ 55

Chloride of benzoyl .

CTBKKSl

140-5

189-5

184-2...187-8 „ 198

Biomme • • • •

Br»

160

55-6

54 ... 28-7 „ 63

Bzomide of methyl .

CH'Br

55-3

58*2 . . „ 18

Bromide of ethyl

C«H»Br

109

77-3

78*4 . • „ 41

Bromide of amyl

C»H»Br

151

148-3

149-2 . . „ 119

Bzomide of ethylene .

C«H*Br«

188

99*6

97*5... 99*9 „ 130

Iodide of methyl

OH»I

142-1

65-0

65-4... 68*3 „ 43

Iodide of ethyl

C«H»I

156-1

870

85-9... 86-4 „ 71

Iodide of amyl

C»Jtl"I

198-1

153-0

152-5...155-8 „ 147

Chloride of solphnr .

SCI

67-5

45-7 . . ,,140

Chloride of phosphonifl

PC1»

137-5

93*9 .

. . „ 78

Bzomide of phoephomB

PBr«

271

108-6 .

> . ,,175

Chlonde of silioon •

SiCl*

170

121-6 .

. . „ 59

Bromide of rilioon

SiBf*

348

144-0 .

. . ,,153

Chlomde of arsenic .

AbCI*

181-5

94-8

. . ,,133

Chloride of antimony

SbCl*

235-5

100-7 ,

. . „223

Bromide of antimony

SbBr*

869

116-8

. . ,.275

Chloride of tin

SnCl*

260

132-4

. . ,,115

Chloride of titaninm .

TiCl*

126-0

. . ,.186

The componnds PCI* and AbCI', have nearly ec[nal atomic Tolmnee whence it may
be inferred that phosphorus, and arsenic, in their hquid com^nndB, have equal atomic
Tohnnee. The same condnsion may be drawn regarding tin and titanium since the
atomie Tohimes of Snd* and TiCl^ are nearly e^nid.

SUrogei^-^omfounde. — In compounds belonging to the ammonia type, the atomic
Tolnme €i nitrogen is 2*3. This result is deduMd from the observed atomic Tolnme of
phenylamine C*H^, which is 106*8. Now the atomic volume of6C-i-7H — 6.11•l-
7 . 6*5 «• 104*5. which number, deducted from 106*8, leaTes 2*8 for the atomie volume
of nitiogen.

The atomic vohime of c^mogen deduced from the observed atomic volume of ^^anide
of phenyl, CN.C^*. or CH«N, is nearly 28. Thus: —

Atomic volume of CrQ'N

C^»

„

»♦

» 121*6
- 93-5
» 28-1

A shnilar calculation, founded on the observed atomic volume of mnide of methyl,
CHV, fi^M* fixr the atomic volume of cyanogen, the number 26-8. The atomic volume
of liquid cyanogen determined directly at 87° or 89° C. above its boiling point, is

418

ATOMIC VOLUME.

between 28*9 and 30*0. As a mean of these Talnes, the atomic Tdame of eyinoges
may be assumed to be 28 ; and with this yalue the atomic Tolnmes of the liquid cya-
nides are calcnlated Thus, for

Oil of mustard (solphocyanate of allyl), C«H<NS

Atomic Tolume of C*H* . . , «

CN . . . «

S (without the radicle) «

oil of mustard • . ^

If
ft

If
}f

^ C»H»

60-5

280

22-6

1111

The atomic Tolumes of compounds containing the radide NO^ are calculafed on the
hypothesis that the atomic volume of that radide is 33, which agrees nearly irith the
observed atomic volume of liquid peroxide of nitrogen. Thus : the atomic yolnnu of
nitrite of amyl, C*H"NO«-at voL of C»H»» + aL voL of NO«-116-6 + 33-U8-5.

Tablb D, — AUmic Volumes of Liquids containing JSitrogm,

•

A A. a

Atonic Volume at the BofUog FMbL

Subftanoe.

Atomic
Weight.

Calcalated.

Obwrred.

Ammonia .

. H«N

18-8

22-4... 23-8 at W...WQ*

Ethylamine

. C*H'N

62-8

66-3

at 18-7

Tetr^lamine

. C<H"N

106-8

Amylamine •

. C»H»«N

128*8

126-0

„ w

Octylamine .

. C«11»*N

129

194-8

190-0

„170

Phenylamine

. C'Bm

106-8

106-4...106-8 .

n 184

Toluidine .

. C'H»N

107

128-8

Ethylphenylaminc

\ . C^"N

121

160-8

150-6

„2M

DieUiylphenylami]

ae . C"H»*N

149

194-8

190-6

. ,,213-5

^anogen . ^ ,
Hydrocyanic add

. . CN

28-0

28-9... 30-0

. „ 16t

. CHN

33-6

39-1

,, 27

Cyanide of methy

I . C«H"N

665

64-3

» 74

Cyanide of ethyl ,

. C»H»N

77-6

77-2 * . .

„ 88

Cyanide of tetiyl

. C»H*N

121-6

Cyanide of phenyl
Sulphocyanate of i

. C'H»N

103

121-6

121-6...121-9 .

,,191

ttethyl C»H"NS

78-1

76-2... 78-2 ,

. „ 133

Sulphocyanate of

ethyl C»H»NS

1001

99-1

. « 146

Oil of mustard

. C*H»NS

1111

113-1...114-2 .

. »148

Cyanate of ethyl .

. C»H»NO

86-3

84-3.., 84-8 .

. „ 60

Peroxide of nitrog

en . N0«

330

31-7... 32-4

. „ 40}

Nitrate of methyl

. CH«NO«

68-3

69-4

. .. 66

Nitrate of ethyl .

. C«H*NO«

101

90-3

90-0... 90-1

. « 86

Nitrobenzene

. C«H*NO»

123

126-6

122-6...124-9

. „218

Nitrite of methyl .

. CH'NO«

161

60-6

61-6

. 1. IM

Nitrite of ethyl ,

. C«H»NO«

82-6

79-2... 84-6

. 11 18

Nitrite of amyl .

. C*H»NO«

117

148-6

148-4

. 11 W

From the preceding observations and calculations, it appears that the atomic toIbim

of a compound depen£, not merely on its empirical, but likewise on its rational fonnnla ;

in other words, not merely on the number of atoms of its elements, but further on the

manner in which those atoms are arranged. Now a compound may have more than

one rational formula^ according to the manner in which it decomposes ; and hence it

might appear that the calculation of atomic volumes must be attended with oonside^

able uncertainty, inasmuch as the atomic volumes of certain elements, as oxygen and

sulphur, vary according to the manner in which they enter into the compound Alde-

C*H*) CHH))

hyde, for example, may be represented either as ^ [ 0, or as h I ' ^ ^

the atomic volume of oxygen is 12-2 or 7*8, according as it is within or without the
radide, the atomic volume of aldehyde will be 66*2 if deduced from the type HH, and

• Between 44° and 60^ above the boiling point.
X About 35^* aboTe the boiling point.

t Between 87° and 2BP abore the boUlagpout.
§ 37° aboTe the boiling point.

ATOMIC VOLUME.

449

<1'8 if deduced firom the type HH.O. Bnt the atomic weight of aldehyde, and its
Bpeciflc gFavity at a giyen temperature are inyariable ; it cannot therefore haye two
differoit atomic Tolumes. It must be remembered, however, that^ in speaking of a
oompound as having several rational formolae, we consider it rather in a dynamical
than in a statical point of view ; as under the influence of disturbing forces, and on
the point of undergoing chemical change. But i^ on the other huid, we regard a
eompound in its fixed stetical condition, as a body possessing definito physical proper-
ttfls, a Cftrtaiu speciflc gravity, a certain boiling pointy irate of expansion, re&active
power, &BC^ we can scaroely avoid attributing to it a fixed molecular arrangement, or,
at an events, supposing that the disposition of its atoms is confined within those limits
which constitute chemical types, ^t is found, indeed, that isomeric liquids exhibit
equal atomic volumes only when they belong to the same chemical l^pe. If this view
be oozieeti the relation between the atomic volumes of elements and compounds, may
often render valuable serrioe in determining the rational formula which belongs to a
otMnpound in the state of rest. Thus of the two atomic volumes just calculated for
aldcJi^tte, the number 66*2, deduced firom the formiUa G^'O.H, agrees with the
observed atomic volume of aldehyde, which is between 56*0 and 56*9, better than 51*8,

the number deduced from ^ [O. This result leads to the conclusion that the

aldehydes belong to the hydrogen type rather than to the water type.

There are many groups of liquid compounds, irrespective of isomerism or similarity
of type^ the members of which have equal or nearly equal atomic volumes. The fol-
lowing table exhibits the calcnlated atomic volumes of several of these groups :

Water ...

RH)

18-8

Ether

C*H»H)

106-8

NH»

18-8

, Tetrylic aicohol

C*H»«0

106-8

Phenylic alcohol
Tetrylamine

C*H«0

106-8

Bi«

55-6

C*H»»N

106-8

Cyanogen •
jydehyde .

560
56-2

Fhenjlamine
Butyric add

C«H^
C*H»0«

106-8
108-0

Cyanide of methyl

C»H«N

65'5

Acetate of ethyl

C«H«0«

108-0

Bromide of methyl

CH«Br

55*3

Acetic anhydride

C*H»0«

109-2

Chloral

CHCl'O

108-1

Alcohol

C«H«0

62-8

Dichlorinated chloride

Aeetieadd

C«H*0«

64*0

of ethyl

crE«a«

106-9

Formate of methyl

cm*o»

640

Monochlorinated chlo-

Cyanate of methyl

O^H^NO"

63-3

ride of ethylene

c*H«a»

106-9

Ethylamine

C'ECN

62-8

Bromide of phos-

Sulphide of carbon
Iodide of methyl

CS»

62*3

phorus • .

PBr»

108-6

0H«1

65-0

Yaleraldehyde .

C»H»«0

122-2

Aeetdue . • •

0^*0

78-2

Cyanide of tetiyl

C»H»N

121-5

Cyanate of ethyl

C»H»N

77-5

Bitter almond oil

C'H'O

122-2

Soh^ocyaiiate of me-

uivl

So^hide of methyl .

C^«NS

78-1

Cyanide of phenyl
Sulphide of ethyl

C'H»N
C*H»»S

121-5
121-6

C*H«S

77-6

Tliese groups exhibit an approach to the uniformity of atomic volume which is
obserred in the gaseous state.

Berthelot has adduced a number of examples, showing that when a liquid compound
is formed by the union of two other Uquids, whose specific volumes are denoted by A and
B, with elimination of x atoms of water, the specific volume of the compound is nearly
V A + B— «C (the atomic volume of water being denoted by C). Berthelot*8 obser-
vattonsy however, were made at medium temperatorps, not at the boiling points of the
liquids (Ann. Cfa. Fhys. [3] xlviii. 322).

8. Of flottd Compeoads* (H. Kopp, Fogg. Ann. xlviL 133 ; lii. 243, 262 ; Ann.
Ch- Fharm. xzxvi 1. — Ammermuller, Fogg. Ann. xlix. 841.— H. Schroder, ibid.
L 662; lii 269, 282; cvL 226; cvii. 113.— Filhol, Ann. Ch. Fhys. xxi. 415.-—
Flayfair and Joule, Chem, Soc Mem. ii. 477; iii. 54, 199; Chem. Soc. Qu. J.
i 121.— H. Schiff, Ann. Ch. Fharm. cvii 64 ; cxii. 88.— 0m. i.- 67—86.)

The most general relation that has been observed between the atomic volumes of
of solid compounds is, that isomor^hoM compoimds have equal atomic volwnes^ in other
words^ their densities are proportional to their atomic weights. Such is the case, for
iple, with carbonate of strontinm (strontianite) and carbonate of lead (witherito).
Formote. At. Weight. Sp. Gr. At. Volume.

Sr«CO» 147-6 8'60 41-0

PVOO* 267-4 6-47 41-4

VOL.L GC>

450

ATOMIC VOLUME.

If the erystalline fomui are only spprozimfttely similar, the atomic volmnes also iie
only approximately equal, the difference being leas aa the anglea of the two ojstdlliiie

forma are more nearly equal, and their axes more nearly in the aame ratio. An
alteratiou of atomic volnme, soch aa ia often prodnoed by the introdnetioa of one
element into a oomponnd injplaoe of another, ia attended with a ooneaponding altera-
tion of Gzyatalline form. l4ie atomic rolnme may likewiae be altered vithout any
change in the composition of the body, Tis. by change of temperature, and this aho
produoea in most caaes, aa Mitacherlich haa ahown, a corresponding alteration in the
magnitnde of the angles. In crystala of the regular aystem, however, TBiiation of
temperature producea no alteration either in form or in atomic Tolnme.

In dimorphoua compounds, each modification^ haa a density, and therefiofe aho an
atomic Tolnme, peculiar to itsell

The equality, exact or approximate, of the atomic Tolumes of iaomc
haa been traced by Hugo Schifi| throughaereral classes of salts, o
of the general form, M%0«.7HK) {vUrioU), in the double suli

daaa, '^ |S0*.3HK), and in the alums. The atomic Tolumes of these oom-

pounda are given in the following table :

Formate.

Atomle
Weight.

GraTity.

Atonk

VotOM.

FUrioh.

Mg«SO* . 7H«0 .

246

1-686

146

Zn«SO* . 7HH) .

287

1-853

146-9

Ni'SO* . 7HK) .

281*2

1-931

145-6

Co«SO* . 7HH> .

281

1-924

146

Fe'SO* . 7H«0

278

1-884

147-6

(MgCu)SO« . 7H»0
l^nSO* . 7H«0 .

266-7

1-813

146-5

266-6

1-817

146^

MgCdSO* . 7H«0 .

290-0

1-983

146-2

Double Magnetian 8ulphaie$,

(NH«)MgSO* . 3HK)
KMgfiO*.3HK) .

180
201-2

1-680
1-996

1071
100-9

(NH*)ZnSO* . 3H»0
KZnSO* . 3H*0 .

200-6

1-910

104-9

221-7

2163

103

(NH*)NiSO* . 3H«0
KNiSo* . 3H»0 .

197-6

1-916

103-2

218-8

2123

1031

(NH*)CoSO* . 8HK)
KCoSO* . 3H«0 .

197-6

1-873

105-4

218-7

2-164

101-6

(NH*)FeSO* . 3H«0

196

1-813

108-1

KFeSO* . 3BP0 .

217-2

2189

99-2

(NH<)CdSO« . 3HH)

223-7

2-073

107-9

KCdSO* . 3H*0 .

244-9

2-438

100-5

(NHyCuSO* . 8H«0

199-7

1-931

1034

KCuSO* . 3H*0 .

220-9

2137

103-S

Mums.

KA1«S«0> . 12H«0

474-6

1-722

275-6

NaAl«S«0« . 12H«0

468-4

1-641

279-2

{NH^)A1«S«0» . 12H«0 ,
K&*S»0« . 12H»0

463-4

1-621

279-6

600*8

1-846

271-4

(NH*)Cr»S*0« . 12HK) .

• 1

479-6

1-736

276-2

(NH*)Fe«SK)« . 12HH) .

4820

1-712

281-4

The atomic Tolumea of the Titriola are very nearly equal; ao likewise are thoae of
the alums. Those of the double magnesian sulphates, M(K ; NH^)SO*3H*0, differ
somewhat more, the difference between the greatest and least amounting to 8-9. It
is remarkable, however, that the atomic Tolume of the ammonium- ana potaasiam-
aalta in each pair differs firom the mean value (104) by nearly equal values, the ionser
in excess, the latter in defect ,- thus, in the first pair we find, 107-1 — 104 - + 3*1 ;
and 100-9 - 104 - - 3-1 ; and in the second pair : 104-9 - 104 - + 0^; ^
103 - 104 m - 1*0.

ATOMIC VOLUME.

451

The following table contains the atomic Yolumes of certain chlorides^ bromides,
and iodides: —

Formula.

Chloridea.

Chloride of hydrogen
Chloride of lead .
Chloride of iron (ferrosom) .
Chloride of calrinm
Chloride of nickel .
Chlofide of meienrunun, •

Chloride of silyer •
Chloride of cnprosom
Chloride of strontiom .
Chloride of sodinm
Chloride of barium

Bromides,

Bromide of hydrogen •
Bromide of mercnrosnm
Bromide of sodinm •
Bromide of barinm
Bromide of mercnncom .
Bromide of silTer . .
Bromide of lead •

Iodides,

Iodide of hydro^
Iodide of potassinm
Iodide of sodinm .
Iodide of mercnrosnm .
Iodide of silver
Iodide of barinm .
Iodide of merenricnm • •
Iodide of lead

Atomic

Specific

Atomic

Weight.

Grarlty.

Volttine.

36-5

1-601

24-3

139-5

6-78

24-2

63-5

2-628

261

665

2-206

26-2

660

2-66

26-3

136-6

6-320

26-6

143-6

6-617

26-0

98-9

3-70

26-7

79-6

2-96

26-9

68-6

2-148

27-2

1041

3-82

27-2

820

200

41-0

281-0

7-307

38 4)

104-0

2*962

36-2^

149-6

4-23

36 3)

181-0

6-92

30-6>

189-0

6-368

29-8 V

186-0

6-63

280)

1280

2-26

670)
68-3 (

166-2

2-86

160-0

3-46

43-6)

827-0

7-644

42-8 V

236-0

6-36

43-9)

196-6

4-917

39-8)

2270

6-91

38-4 V

231-0

6-07

381)

It will be observed that the atomic Tolnmes of the bromides and iodides do not
agree among themselTes so nearly as those of the chlorides. The atomic Tolnme of a
bromide is not» for the most part, the mean between those of the corresponding chloride
and iodide, but approaches more nearly to that of the chloride. (Schifl)

That isomorphoos compoonds do in many instances occupy equal atomic volnmes
is sufficiently apparent from the preceding examples. Neyeitheless^ Schroder con-
dudes, from calculations founded partly on his own determinations of specific graTity,
partly on those of other observers, that equality of atomic volume is not necessarily
connected with similarity of crystalline form, but is exhibited by hefceromorphous
dements and compounds quite as often as by those which are isomozphous, if not
oftener. (Po^- Ann. cvi 226 ; evil 113.)

Tlie oonnection between the a^mic volumes of compounds and of their elements has
not been so fUly examined in solids as in liquids ; nevertheless certain general rela-
tioDs have been shown to exist. The most important of these relations, first pointed
oot by Schroder, and further established by Kopp, is that equivalent qtuintities of dif-
fertni elemeiUSf in uniting mth the same quantity of a given element (or compound
radicle) receive equal increments of volume. Thus, when 207'4 grammes, or 18-44
cub. oent of lead (FM). 112 grm. » 13 cc. cadmium (Cd'), 63*7 grm. » 7*2 c.c. copper
(On*), or 66*2 grm. — 9*2 &c. sine (Zn*), unite with 16 ^rms. of oxygen (0) to rorm
the compounds Fb*0, CdK), d^c, the increment of volimie is found to be in each case
neariy 2*6 cubic centimetres. Again, in the oxidation of 112 grm. iron (Fe*) to ferrie
oxide, Fe*0*, the increment of volume is 8*1 « 3 x 2*7 c.<i. The explanation of this
law appears to be that certain elements enter into combination with the same atomic
Tofanne that they occupy in the separate state. Such, according to Kopp, is the case
with the heavy metals : so that, bv determining experimentally the atomic volumes of
their oxides, chlorides, nitrates, &c, and depicting therefrom the volumes of the
metals themselves as given in the table (p. 442), the atomic volumes of 0, CI, N0\ &c,

oo 2

462 ATOMIC VOLUME.

which cannot be ohoerred directly, may be found ; thna, a oompariBOQ of the oxidei
abore-mentioned ahowB that the atomic Yolnme of oxygen in these oompomidi ii 2^6.

The metals of the alkalis and earths do not appear to enter into oombiBatioQ with
the same Tolume that they occupy in the free state. Their atomic Tolunes in eom-
bination must, therefore, be caknuated by deducting from the obsenred atomic Tohum
of their salts, the chlorides for example, the volume of the chlorine as detennined
from the chlorides of the heavy metals, this determination of eooTBe resting on the
assumption that the atomic volume of the chlorine in combination is the same in all
analogous compounds.

On these principles, Kopp has made the following estimations of the atomic Tolvnui
of the alkah-metais, earth-metals, and certain sait-radicles : —

NH« in its salts 17-4

K „ 187

Na „ „ 10-4

Ba „ , IH

Sr „ „ 8-6

CO* in' the Cfurbonates of Pb, Od,' F^ Mn^ Ag, Zn, Ba, Ca, E, Mg,

Na»Sr 121

NO* in the nitrates of Fb,Ag,NH\Ba^E,Na»Sr . . .28-6
S0« in the sulphates of Cu, iQ^ Zn, Ca, Hg, Na ... 18*9

80« in the sulphates of Fb, Ba,K, Sr . . . .14-9

a in the chlorides of Pb,Ag,Ba,Ka . . . . .157
CI in the chlorides of NH\ Ga, E, Ccu,Hg,Hhg, Sir . . 19-6

O in the oxides Pb«0, Cd*0, Cu«0, HgK), Zn*0, SnO, Sb*0»,

Fe*0«,CoW, Bi«0«. Pb»0« . 2-6

O in the oxides CcuH), Ag*0, HhgfO, Mo*0« ... .6-2

These values were determined in 1841, and many of them require oorreetion aeeord-
ing to the atomic weights apd densities since established. According to Schroder
(loc, cit)j the relations upon which they depend are true only with regard to iaomtn*-
phous compounds, being regulated by the following general law: ** If two elemals or
^ups of elements, A, B^ &c, unite with other elements or groups, C, 2>, E^ &e^ form-
ing comoounds AC and BC, AD and BD, AE and BE, &c, which belong to the sum
type, and are isomorphous by pairs, the difierences of atomic volume of AC and BC^ JJ)
and BJ), AE and BE, &c., are always equal ; but, if these pairs of compound an not
isomorphous, or belong to different ty]^ then the differences of atomic Tolnme are
nnequalL"

Messrs. PI ay fair and Joule hare observed some remarkable relatians betwea
the atomic volumes of crystallised salts and that of the water which tiiey contain, rii.
1. In certain highlv hydrated salts, viz. the arsenates and phoapkates wUk 12 st. wkr
and in carbonate of eodivm with \h at, loater, the volume of the entire molecule is the
same as that of the water of crystallisation frosen into ice, the partides of the add
and base appearing to be interposed between those of the water without incnanqg
the total bulk. The following table contains the specific gravity oS seme of these
salts, as calculated upon this hypothesis, and as determined by direct ezperiment:

Salt. Spedfle Gravity.

Exp. Ctk.

Na«CO* . lOHK) 1464 1468

Na«HPO* . 12H«0 1-625 1*627

Na*PO* . 12BD»0 1-622 1-622

Na*HAsO* . 12H*0 .... 1-786 1-786

Na'AsO* . 12HK) 1-804 1-634

In cane-sugar and milksugar, the atomic volume is the same as that of the hjdrog^
and oxygen, supposed to be united as water and frozen. Specific grantj of cane-
sugar on this hypothesis » 1-686 ; by experiment » 1*686 ; of milk-sugar, by calcnlatiaB
1*634 ; by experiment 1-631.

2. In another class of sfdts, including the hydrated magnesian sulphates (IPOwSO*
+ 6H*0), normal suiphate of aluminium, borax, pyrophosphate of sodium, and the
aluTns, the atomic volume is made up of the sohd water and of the base (VO or
M^O') ; in other words, the volume of the hydrated salt is made up of that of the irater
of ciytallisation frozen into ice, and that of the base as it exists in the fiee itate, or
in the anhydrous salt (For details see the memoirs cited on page 449.)

ATOanc WazORTS. The ultimate constitution of matter, and its finite or
infinite divisibiUfy, have been made the subjects of specuktion and azgnment fiom
almost the earliest times. The molecular idea of matter seems to hate prevailed in
the primitive philosophies of the Hindoos, Phcenicians, and FIgyptians, from the lait

ATOMIC WEIGHTS. 453

of whom it was noLably traxunnitted to the Gieeks. Among them, we find the notion
of finite diTiflibuitj oonrtitating the basis of the oosmogony of Democritos, who appa-
renitj acquired the doctrine directly from Lencippns. Snbseanently Epicurus, and the
Epicureans generally, extended the atomic hypothesis, whicli, however, was strongly
opposed b^ Empedodes and the later Pythagoreans, who contended for the in-
flmte diYuibilify' of matter, and for its continuity in any ^ven mass. Plato and
Aristotle also, especially the latter, advocated the notion of infinite divisibility. In
modem times, the doctrine of material atoms was maintained by Newton, and opposed
by Descartes, Leibnite, and Euler. After the time of Euler, the question of the ultimate
consdtation of matter fell into some neglect, although the non-atomic view seems to
have been generally preferred, until Dalton, in 1804 — 8, revived the atomic hypothesis,
in order to account for the phenomena of chemical combination in definite and multiple
proportions, which he first brought prominently into notice. Prior to his discovery, tiie
chemical composition of bodies, as determined by analysis, had been expressed in
centesimal proportions only, whereby the relations in composition of dififerent bodies
were in great measure oonccflled from observation. Thus, the relative composition of
olefiant gas and marsh gas, was expressed very impexfectly bv saying that the former
contained 85*7 per cent of carbon and 14'3 per cent, of nyorogen, while the latter
eootaiiied 75*0 per cent, of carbon and 25*0 per cent of hydrogen. It was from the
results of an examination of these two gases that Dalton was first led to the conception
of bis theory. He ascertained that both gases consist of carbon and hydrogen only,
and set out the centesimal composition of each in the cnstomaiy manner. But he
observed further, that the ratio of hydrogen to carbon is exactly twice as great in the
one case aa in the other; that in olefiant-gas, for instance, the carbon is to the hydro-
gen as 6 to 1, whereas in marsh-gas it is as 6 to 2. Or, in other words, a given
quantity of carbon unites with either one or two proportions of hydrogen to form the
respective compounds, olefiant-gas and marsh-gas. Dalton, whose turn of mind was
essentially mechanical, explain^ the constitution of these two compounds bysupposing
that the first consisted of 1 at of carbon united with 1 at. of hydrogen f^O, while
llie second consisted of 1 at of carbon united with 2 at of hydrogen 0^0, the atom
of carbon being considered to have 6 times the weight of the atom of hydrogen.
He then calculated the composition of other bodies on the same plan, and found, for
instance, that the quantity of hydrogen which unites with 6 pti, of carbon to form
olefiant gas, unites with 8 pts. of oxygen to fonn water. Hence water was represented
by the symbol 0O, the atom of oxygen being considered to have 8 times the weight
of the atom of hydrogen. The crowning point of Dalton's theory was reached when
he diwovered tliat the numbers which expressed the respective combining proportions
of carixm and oxygen with 1 pt of hydrogen, also expressed the pro|X>rtions in which
tbey combine witii one another. Thus the ratio of carbon to ox^sen in carbonic oxide
gas was found to be as 6 to 8 ; whereas in carbonic anhydride gas it was as 6 to
twice 8. The former compound he considered to result from the union of 1 at of
carbon with 1 at of oxygen 0O ; Ai>d the latter to result from the union of 1 at% of
carbon with 2 at of oxygen 0#0* Dalton extended the same views to the com-
poands of nitrogen, and concluded that the quantity of that element which united with
1 pt of hydrogen to form ammonia 00, united with 8 pts. of oxygen to form nitrous
gae QO- ^e iQ>7 <^ppty this formula for nitrous gas to the oom^und known as
nitrous anhydride, thoi^gh, from an enor in the rouffh process of analysis then adopted,
it was intended to apply to what is now called nitnc oxide, or deutoxide of nitrogen,
Bven at the present aay, it is highly interesting to compare the information afibrded
by Dalton's expressions for the above-mentioned compounds, with the information
siBsded by a statement of their respective centesimal proportions, thus : —

DalUm'i EzpreMloos.
.6 + 1 96

CeDteiinul Proportions,

Olefiant-gas .

86-72 + 14-28

Manh-gas

. 6 + twice 1 #0#

75-00 + 2500

Water .

.8+1 00

88-89 + 11-11

Carbonic oxide

.6+8 mo

. 42-86 + 5714

Carbonic anhydride

. 6 + twice 8 O#0

27-27 + 72-78

A »

.5+1 a#
.5+8 ao

82*85 + 17-65

Hitzons gas

86-80 + 63-20

Dalton thus established that general piinciple in chemistry known as the law of
combination in definite and multiple proportions. He showed that a pais
ticolar number might be selected for every element in such a manner that the ptopoTm
tioQS by weijg^t in which any two or more elements combine with one another, should
be always in the ratios of their respective numbers, or of different multiples of those
onmbezm. And he accounted for this law by supposing that the elements unite with one

G o 3

454 ATOMIC WEIGHTS-

another atom to atom, and that the proportional number accorded to each pazfieiilar
element ezpNsaes the lektive' weight of its atom. Hydrogen being the lifj^test
aabstanoe in natore, was at once choeen by Dalton as the unit in hia scale of atomia
weights, and the weights of the atoms of other elements were established by asccr^
taining, direcUy or indirectly, the respectiTe qnantitiea of those elements iriiich unite
either with 1 pt of hydrogen, or with the quantity of some other element which unites
with 1 pt of hydiogen. But many chemists, who speedily admowledged the truth of
Dalton's laws of combination, refused to admit the atomic doctzine which he had de-
duced therefrom. Among these was DaTy, who introduced the word proportion as
a substitute for Dalton's word atom, oonceiying the use of the latter word to be objection-
able, as iuTolying a theoretical assrmiption. At the present day, the wora atom
is most generally employed by chemists ; but, while some use it in its strict Dal-
tonian materialistic sense, others use it^ in an abstract sense only, to express the
smallest indifisible combining proportion of a body, and consider the proportiona]
number of a body as an ultimate or unexplained property pertaining to it Dalton's
symbols were speedily replaced by those now in use, idiich represent the abbreviated
names of the elements. Krery such symbol is used to express one atomic proportion of
its particular element. Thus, CI stands for 35*5 pts. of chlorine, Na for 23 pts. c»f
sodium, and As for 75 pts. of arsenic, as compared with 1 pt. by weight of hydrogen.
"Every compound body being composed of two or more elementuy atoms, is expressed
by an allocation of symbols. Thus, common salt or chloride of sodium is reprea«ited
by the formula NaCl, which implies a compound of 28 pts., or 1 combining pro^ortioo
of sodium, united with 35*5 pts., or 1 combining proportion of chlorine. Again, tri-
chloride of arsenic is represented by the formula AsGl*, which implies a compound of
75 pts., or 1 combining proportion of arsenic, united with 106*5 pts. or 8 combining
prc^rtions of chlorine.

iTke proportional number or tUomie weight of a compound body it ike turn of ike
atomic weights of its constituents. Thus, the atomic weight of chloride of sodium is
58'5 and that of trichloride of arsenic 181*5. The relative quantity of a compound
body, represented by its formula, is frequently spoken of as its atom, and tha« is
nothing unpliilosophical in such an emi>loyment of the word. By the atom of sodium,
for instance, is understood, the least indivisible proportion of the elementary body
sodium, and by the atom of chloride of sodium, the least indivisible proportion of the
compound body chloride of sodium, that can have any existence. Soon after the
publication of Dadton's theory, it received a valuable corroboration, through its adap-
tability to groupings of elements or compound atoms. WoUaston, in the course of
some analytical experiments, noticed, that if in the two carbonates of potasnum,
the weight of oxiae of potassium be taken as constant^ then the weights of car^
bonic anhydride in each salt are to one another as 1 to 2 ; and Thomson made a
similar observation with regard to the two oxalates of potassium. Hence these salts
were represented at that time, in accordance with Dalton's views, as consisting respec-
tively of one compound atom of oxide of potassium, united with one or two oamponnd
atoms of carbonic anhydride, and with one or two compound atoms of oxalic anhjtlride.
The compound atom of a body, or more correctly the atom of a compound body, is
now often spoken of as its molecule, but in many cases there is a distinction between
the application of the two words which will be presently adverted to.

The accuracy of Dalton's laws of combination in definite and multiple proportions,
was confirmed by a reference to the previous neglected researdies of Wenzel and
Richter upon the double decomposition of salts; and by the subsequent brilliant
researches of Gay-Lussao upon the laws of combination by volume; in which he
showed that the combining proportions of simple and compound ^ases might be ex-
pressed volumetrically or by bulk, as well as numerically or by weight.

It is worth while to refer for a few moments to the above-mentioned experiments
of Wenzel and Richter. If we add together solutions of chloride of sodmm and
nitrate of silver, which are both neutral salts, we get by double decompositian,
chloride of silver and nitrate of sodium, and the mixture still remains neutraL There
is no redundancy or deficiency of either sodium or silver, but the quantity of sodium
separated from its chloride is exactly sufiicient to replace the silver separated from its
nitrate, and vice versA, Wenzel of Freyberg in Saxony, as early as the year 1777,
made very many analyses of salts with great accuracy, and was thereby cnaUed to
account for this neutr^ty, resulting from the mutual decomposition of neutral salts,
by showing that in all salts the quantities of salt-residue, so to speak, which are com-
bined with equal weights of some one metal, will also combine with equal weights of
any other metal Thus, if y grains of chloride of sodium, and g grains of nitrate of
sooium alike contain x grains of sodium, then (y — «) 4- to gnuns of chloride of silver,
and {s ^ x) ^ w grains of nitrate of silver will alike contain w grains of sflvs';
because the quantities x and w represent the relative combining proportions of the
metals, sUvex and sodium, which can take the place of one another, and unite with the

ATOMIC WEIGHTS- 455

amount of chknine or other salt mdide, or rendue. Bichter of Breslau in
Stlesia, pnbluhed, in the year 1792, what may be regarded as an extension of
the TiewB and ezperimentB of WenzeL He showed that the neutrality of a saline
aolntion doee not change during the direct precipitation or sabstitution of its metal
by some other, and that the reepectiye quantities of difierent metals which displace one
another in salts, all unite with the same weight of oxygen. He also constructed
a table of the quantitiee of different oxides or bases, which contain replaceable
askounta of metal, and of the quantities of different adds which can be neutralised by
those quantities of the respective bases. His experimental results were yeiy inaccu-
rate, but his notions of chemical decomposition, nad they received due attention at
the time^ most have led directly to the doctrine of combining proportions, if not to
the Daltonian theory of atoms. It was not untQ some time after the publication of
Ihaiton's views, that Benelius first called attention to the prior researches of Wenz^
and Bichter, as affording a valuable confirmation of the laws of chemical combination
which Dalton had enunciated.

In the establishment of proportional members or atomic weights, two distinct
points have to be considered, namely the exact determination of the ratios, according
to whieh bodies combine, and the correct expression or interpretation of those ratios.
The first is a question of experiment, while the second is one of judgment or inference.
Thus whether the ratio of hydrogen to nitroeen in ammonia is as 1 to 6, or as 1 to
4*67 is a question of mere experiment : but whether the atom, or smallest indivisible
combining proportion of nitrogen is 4*67 times, or 14 times as heavy as the atom or
smallest indivirible combining proportion of hydrogen, and consequentiy, whether the
molecule of ammonia consists of one light atom of nitroeen united with 1 of hydro-
gen, or of one heavy atom of nitrosen united with 3 of hydrogen, are questions for
the judgment, which can only be decided by an intimate acquaintance with, and careful
consideration of very many dreumstances relating to the respective bodies and their
congeners. The numbers originally chosen by Balton to express the ratios in which
the diflferent elements unite with 1 part of hydrogen, are most of them very in-
eorrect. Thus his number for nitrogen was 6 instead of 4*67, that for carbon 6 instead
of 6, that for oxygen 7 instead of 8, that for phosphorus 9 instead of 10*83, that for
sulphur 13 instead of 16, and similarly with the remainder. Davy raised the number
for oxygen firom 7 to 7*6, which Front, soon after, on theoretical ^unds increased to 8.
But the firft series of numbers, deduced from trustworthy experiments, was drawn up
by Bexseliua, whose remits, the work of a lifetime, must ever exdte our highest
admiration for the marvellous industry and skill by which they were achieved. Of
late years, when analytical and ^thetical processes have been so greatly simplified
and improved, many of his atomic weights have undergone slight corrections at the
hands of Dumas, Marignac, Felouze, Stas, Maumen^ Erdmann, Marchand, and others,
but the general exactitude of his numbers still remains unimpeached. Berzelius,
following the example ofWoUaston in this country, selected the atomic weight of
oxygen as the unit of lus scale, and the same plan was adopted until within t^ last
twenty years by continental chemists in general. The atomic weight of oxygen
was fixed at 100, and those of the other elements estimated in accordance therewith ;
but the simpler numbers by whidi most of the ratios are expressed on the hydrogen
scale, have eventually secured for it the preference.

In the year 1815, Front, in a paper *' on the relations between the specific gravities
of bodies in the gaseous state, and the weights of their atoms," propounded the idea
that the atomic weights of all bodies are multiples of the atomic weight of hydrogen.
His opinion was shared by Dalton on other grounds, and met with veiy general ac-^
eeptance in this country. But it was never acknowledged by Berzelius, or until lately
by any large number of continental chemists. Although Front's views must be con-
sidered, in the present state of our knowledge, to rest rather upon a speculative than a
substantial philosophical basis, it cannot be denied that the tendency of modem investi-
gation has been to confirm his law or rather a certain modification of it, which Dumas
first introduced in a definite form, but which Front himself seems to have admitted. Ac-
cordmg to this modification, the atomic weights of all bodies are multiples by whole
numbers of a submultiple of the atomic weight of hydroeen. A striking confirmation of
this view occurred in the year 1840, when Dumas and Stas showed that the atomic
wa^t of carbon is exactiy 6. In 1843 Dumas also showed that oxygen and hydrogen
unite to form water exactly in the ratio of 8 to 1, and his experiments were confirmed by
those of Erdmann and Marchand. Then Felouze and Mangnao separately ascertained
that the atomic weight of nitrogen is 14 ; andMaumen^ Marignac, and Felouze, sepa-
rately ascertained that the atomic weights of chlorine, silver, and potassium coincide
almost absolutely with the numbers of 36*6, 108, and 39 respectively. Felouze showed
also that the atomic weights of sodium, barium, and arsenic are 23, 68*6, and 76 respec-
tively. At the present time, out of fifty-eight elementary atomic weights, calculated

oo 4

456 ATOMIC WEIGHTS.

from the acknowledged best experiments, not more tlum lia]f a doaen difGer appndaUy
from mnltiples by whole numbers of half the atomic weight of hydrogen. Sobm of
these exceptional numbers ought probably to be doubled, whereby they woold aoeoid
with Front's modified law, while others of them can hardly be looked upon as latiifiMs
torily determined. It is worthy of observation also that the smallest atomie veightB
whidi, as a general role, are those of the best known, and most easily estimated
elements, accord the most precisely with Front's law. Dnmas is of opinion tiiat
some of the exceptional nnmbers are multiples of one-firarth the atomic weight of
hydrogen. Stas, nom an daborate series ox experiments, the exactnees of irkicfa it
seems impossible to exceed, has arrived at the conduaion that Front's law is not tnu^
or at any rate that it is only approximatiyely true. He has obtained the Mowing
numbers tar potassium, sodium, silver, sulphur,' nitrogen, chlozine, and lead. Eaeh
number has been derived from numerous ekisely concordant experiments perfixrmed by
different processes, on a scale of magnitude and with a desrae of dehounr, hitherto
unequalleo. His number for potassium, however, is the only one which wkn eon-
sid^bly i.s. i per cent from toe usually accepted number :

8tit*t Domben* DUferewxi
Fotassium
Sodium
Silver
I Sulphur

Nitrogen
Chlonne
Lead

89*130

0-130

28-060

0-060

108

107-948

0067

82-074

0-074

14041

0-041

36-5 85-460 - 0*040

108-6 108*467 - 0*043

Hence it is apparent that the differences in the experimental determination of the
ratios according to which bodies combine with one another, have been lednoed within
veiy narrow limits. But the case is fax otherwise when we come to consider the ia-
terpretation of these ratios, or the establishment of the atomic weights of simple and
compound bodies. Thus mercuiy unites with chlorine in two propoitiona to fona
calomel and corrosive sublimate respectively. In the former compound the zatio of
chlorine to mercury is as 36*6 to 200 ; and in the latter as 36*6 to 100 ; or as twice
36*6 to 200. We have therefore to decide between the numbos 200 and 100, wboe-
with to expess the atomic weight of mercury. If we select the number 200, the tot'
mula of calomel will be HgOl, and that of corrosive sublimate HgCl*. If we aeleet the
number 100, the formula of calomel will be Hg'Gl, and that of oozrosiTe saUimat^
HgCL Mudi the same difficulty also exists in those cases in whidi two dements oomlHne
in only one proportion. Thus chlorine unites with silver in the proportion of 86*6 to
108, or to twice 64. Now supposing even that we all agree to represent calomel hj
HgHyl, and corrosive sublimate by HgCl, we have still to consider whether chloride oif
silver is a body analogous to calomel or to corrosive sublimate, before we can decide
npon representuig it by the formula Ag^Cl, in whidi Ag « 64^ or by the fonnola A^
in which Ag ■> 108. Again, chlorine unites with aluminium in the single proportion
of 36*6 parts of chlorine to 9 parts of aluminium. Chloride of aluminium may conse-
quently be represented by the formula AlCl, in which Al « 9 ; or by A1C1^ in which
Al - 18 ; or bv A1G1>, in which Al <- 27 ; or by AlHJl, in which Al « 46; or hj
A1*C1', in which Al « 13*6 ; or by one of manv other poesible formnhe. From a
variety of considerations, more or less complicated, the last formula, A1K71*, is the one
which has been generally but not unaminously adopted. Again, the composition of
marsh-gas has been ascertained with the greatest certainly. The ratio of carbon to
* hydrt^n is precisely as 3 to 1. Hence we may represent the gas by the formnla CH
in which the atomic weight of carbon a 3 ; or by uie formula GH*, in whidi G » 6;
or by the formuLi CH*, in which C - 9 ; or by the formula CH\ in which C - 12;
or we may represent the gas by the formula CPB.*, in which C » 6 ; &c. && At the
present time, aU chemists are agreed that the molecule of marsh-gas contains fom atoms
of hydrogen, but they disagree as to whether it contains two atoms of carbon hsTing
each the value 6, or one atom of carbon only having the value 12.

It is obvious that the atomic weishts of an element and of its combinations, shoold
be selected so as to express the entire Stfies of combinations by the simplest series of
formulffi ; so as best to accord wi^ tiie cnemical properties and metamorphoses of the
bodies ; so as best to illustrate their analogies with other bodies ; and so as to be in
relation with their physical properties, such as their specific volumes, spedfie heats,
isomorphism, &c Now it so nappens that these different requirements, chemical and
physical, are not always satisfied by one and the same number. Hence we haie to
subordinate requirements, much in the same manner that zoologists and botanists sub-
ordinate characters, and to select that atomic weight which fidjUs the greatest number,
or rather the most important of them. Many of the discrepancies which were fimneilr
thought to exist between the numbers deduced respectively from chemical and physical

ATOMIC WEIGHTS. 457

eonaideraAioiM, hare of Ute ^ean been satis&ctorilj eiplained away ; and we haye
emy reason to beliere that with increasing knowledge leading to higher generalisations,
all sndi anomalieB as at present exist wilfalso disappear.

In a determination of the least indiyisible combining proportion, or chemical atom
of a body, it is dear that purely chemical considerations mnst be entitled to the greatest
weight, and to some of these we will now direct our attention. If we examine mars h-
gas, for instance^ we soon perceiTe that its molecule contains fonr atoms of hydrogen ;
because we find onrselyes able to displace one-foorth, or two-fonrths, or three-fourths,
or fbnr-foinths of its hydrogen. In other words, we find that its hydrogen is diTisible
into lirar equal parts; and as the atom of hydrogen expresses the least indivisible part
of Uydrogen that can enter into a combination, it is evident that marsh gas must con-
tain four of soch parts, or Ibur atoms, of hydrop^en. Thus taking the formula GLrH* fi>r
mazab-gas, we have the following series of derivatives, the constitution of which could
not be expressed, save by aooordmg four atoms of hydrogen to the molecule of the gas.

CH* Marsh-gas OH*.

O* B*CL Chloride of methyl 0* H^a Sodium-methyL

C H'Cl' Bichloride of methylene . .

CHOP Chloroform C'HI' Iodoform.

0*C1* Tetrachloride of carbon . .

Henoe the metamorphoses of manh-gas show that the most simple formula by which
the zatio of its carbon and hydrogen can be expressed, namely, CH, is not the pioper
fomtola of the body. Again, the quantity of marsh-gas, which is the resultant of any
reaction, cannot be expressed with less than four atoms of hydrogen. Thus, when
acetic acid is decomposed by heat, we have the reaction, C^'H^O* » C'H* + CO*.
The quantity of carbon C', which unites with 4 pts. of hydrogen to form marsh-gas,
unites with 82 pts. of oi^gen to form carbonic anhydride ; but whereas the quantity
of hydrogen in marsh-^ i^ experimentally divisible into 4 pts., the quantify of 03^-
gen m carbonic anhydride is experimentally divisible into 2 pts. only ; so that while
wa represent marsh-gas by the formula 0* H^, we represent carbonic anhydride by
the formula 0" 0^ as will be again referred to.

The same dass of chemical reasons which induce us to regard marsh-gas as tetra-
hydxie, also induce us to regard ammonia as trihydric. In ammonia we can replace
one>third, or two-thirds, or three-thirds of its hydrogen, but we cannot replace one-
fomrth, or two-fourths, or three-fourths. The hydrogen in marsh-gas being divisible
into 4 equal parts, the hydrogen in ammonia is divisible into 8 equal parts only, and
eonaequoitly the molecule of ammonia contains 3 indivisible proportions or atoms of
hydiogen. We are acquainted with many ammonias in which one, two, and three-
thirds of the hydrogen are displaced, for example :

K' H> Ammonia. N' HI' Biniodamide

VWK Potassamine N'Hg' Trimercuramine, &c &e.

But the most striking illustration of displacement by thirds is afibrded by Hofinann's
researches on the volatile alkaloids, in which he successively displaced one, two, and
three atoms of hydrogen in ammonia by a mere continuation .of one and the same
proeess:

AonMifa. Bthylia. DIcthjNa. TrIcCbylla. Bthjl.nethyl.«DUiDe.

!H (H (H (Et (Et

H N-m N'^Et N'^Et N-^Me&a&c

H (Et (Et (Et (Ph

Again, in ninety-nine cases out of a hundred, the quantity of ammonia which is the
agent or resultant of a reaction, must contain 3 or some multiple of 8 atoms of
hydrogen. Thus when ammonia results from the hydrogenation of nitric add, we
obtain, for every molecule of nitric add containing 1 atom of hydrogen, a quantity of
ammonia containing 3 atoms; and when ammonia reacts with benzoic chlondde-
hyde to form benzamide and sal-ammoniac, we require, for eveiy molecule of benzoic
chloraldehyde decomposed, a quantity of ammonia containing ttnce 3 atoms of hydrogen,
2K* H' ; and so in other instances. In the great minority also of compounds which
ammonia forms directly with other bodies, the quantity ox combining ammonia mast
necessarily be represented with 8 or some multiple of 3 atoms of hydrogen. Thus the
sing^ molecule dT aldehyde unites with N' H', and the single molecufo of nitrate of
silver with 2N' H". &c. Express these combinations or reactions how we please, we
cannot rqireeent them save with a proportion of ammonia oontaininff 3 or some mul-
tiple of 3 atoms of hydrogen, and ninety-nine cases out of a hundred will yield the same
result. In those few exceptional cases in which the combining or reacting ammonia need
not necessarily be represented with 3 atomsof hydrogen, it may be, and we contend ought
to be, so r^resentea. Thus when ammonia is decomposed by excess of dilorine, the re-

m m

atftion might be expressed, thus: N' ••• CI » N^Cl -i- Hd: but it is quite certain

458 ATOMIC WEIGHTS.

that the molecule of chloride of nitioffen oontaiiis 8 at of ehlorine^ and conaeqqently
the reaction by which it is pzodnoed ought to be ezprewed thus : N* fi* i- df «
N* CI* + 3HG1 ; and so in other infltanww.

The same class of chemical reasons which indnoe ns to regard marsh-gaa as tetra-
hjdric and ammonia as tiihydrio, also indnoe ns to regard water as dihydric In wrmter
we can replace one-half or two-halyes of the hydrogen, bat we cannot replace one-third
or two-thirds as in ammonia, or one-fourth or three-fourths as in marsh-gas. If we
act upon water O* H' by metallic potassium, we di^kce one-half its hydrogen to form
the very definite body hydraU of potassium O* KH ; and if we act imon hydrate of
potassium by potassium, we di^plaoe the other half of the hydrogen and form oxide of
potassium €>* KK. Or instead of introducing a second atom of potassium, we may
turn out the first one. Thus if we treat hydrate of potassium O* KB. with iodide of
ethyl we obtain alcohol O* EtH, or we put a molecular grouping called ethyl in tlie
place of the potassium, which ctisplaced one-half the hydrogen of the water. Now if
we act upon the alcohol thus formed by potassium, it behaves exactly as did the
hydnte of potassium, or in other words it yields the remaining half of the origiiial
hydrogen in exchange for potassium, and we obtain ethylais of potassium O* EtK. If
we now act upon this new body by the iodide of metiiyl or ethyl, we turn out the
potassium representing one-half the original hydrogen and obtain etkylats ofmeihfl
O EtMe, or ethylate of ethyl 0« EtEt

Again, in ninety-nine cases out of a hundred, the quantity of water, whidi is the
agent or resultant of a reaction must contain 2 or some multiple of 2 atams of
hydrogen. Thus, whenever an alcohol, ketone, or any definite organic substaiice,
3ields a hydrocarbon or other compound by dehydration, — ^whenever an organic acid
yields a pyroacid, or other pyrogenous product by dehydration, — ^whenever a salt of
ammonia, phenylamine, or other volatile alkali loses water, — and whenever two com-
pounds act upon one another to form a new body with simultaneous elimination of
water, whether the action be that of an acid upon a hydrocarbon, of an add upon an
alcohol, of an acid upon an alkali, of an add upon an add, of an add upon an alodiyde,
of an alkali upon an aldehyde, or of an aUcali upon an alcohol, — ^the quantity of
water eliminated inevitably contains 2, or some multiple of 2 atoms of hydrogen.
Moreover whenever a oonjueated compound or diameride, a chloraldehyde, an oigano-
metsllic body, &c. &c., is decomposed by water, the quantity of water whidi reacts
must necessarily be represented with 2 or some multiple of 2 atoms of hydrogen.
For example, wnen water reacts with hippuric add to form benzoic add and giyoodne,
for every molecule of hippuric add decomposed, we reouire a quantity of water con-
taining O* H*. When glycerin becomes acrolein by dehydration, for ever[ molecule
of glycerin decomposed we obtain a quantity of water containing 20* fi*. When
nitric add reacts with naphthalene to form nitio-naphthalene, for every molecole of
nitric add which reacts, we have eliminated a quantity of water containing (VH*.
When acetate of ammonia becomes cyanide of methyl by loss of water, for every
molecule of the salt decomposed, we lib^te a quantity of water containing 20' H* ; and
so in an infinite number of other instances. A^dn, in the minority of direct compounds
which water forms w}th other bodies, the combining water must be represent«l with
two atoms, or some multiple of two atoms of hydrogen. Thus the molecule of gtueose
difTers from that of fructose, and that of lactine d^ers from that of dextrine by the
addition of 0* H*. The molecule of turpentine becomes hydrated turpentine by
absorbing SO* H', and so in many other instances. The water of crystallisation in
the great majority of hvdrated salts must be represented with 2 atoms, or some
multiple of 2 atoms of hydrogen. Thus the molecules of chloride of barium, nitrate of
mercurosum, and chloride of copper, crystallise with O* H' ; the molecules of nitrate
of cadmium, chloride of manganese, and nitrate of calcium with 20* H' ; the mde-
cules of chloride of caldum, nitrate of magnesium, and acetate of sodium with 30" H*;
the molecules of microcosmic salt and hy£ate of barium with 40* H* ; the molecule of
borax with 60' H* ; the molecules of <mloride of aluminium and potassio-sulphide of
nickel, with 60* H* ; the molecule of common arsenate of sodium with 7 or 12 O* H^;
and the molecules of alum and rhombic phosphate of sodium with 120* H*, &c &r.
There are some comparatively few salts, the acetate of barium, for example, in whi(4
the water of crystallisation might be represented by JO' H*, or by IJO* H", &a, but
none in which it need be so represented, while there are scarcely anyreactions in which
the resulting or reacting water could possibly be expressed by )0* U' or 1^0* H*, and
none in which it would be correcUy so expr^sed.

We have mentioned above that the quantity of carbon which unites with four
separable portions of hydrogen to form marsh-gas, also unites with two separable
portions of oxygen to form carbonic anhydride. Now each of these separable porti<His
of oxygen is identical with the quantity of oxygen O', which unites with 2 parts of
hydrogen to form water.

ATOMIC WEIGHTS. 459

Lftrtij, when we oome to examine hydrochloric acid, we are unable to show that
its hjdrogen is diTisible, and we consequently look upon its molecule as containing but
oae atom, or one indivisible proportion of hydrogen ; whence we represent the oom-
poimd by the formula Q'H; and we may anticipate here by remarking, that all
phTEieal eridenoe tends to show that the molecules of marsh-gas, ammonia^ water, and
chlochydric add contain respectiyely four, three, two, and one atom of hydrogen.

In addition to the class of binai^ hydrides, the atomic weights of the principal
membera of which we have just consideied, there is another large class of hydiogenised
bodies, namely, the dass of temaiy or oxacids, the correct determination of whose
molecules is of the highest importance. The molecule of oxalic acid, for instance, may
be represented by the fcmnula C'HO"< «, or C^* *RK)**^ ' , according as the add is found
to be monhydric or dihydric, monobasic or dibasic. Now the polybasidty of an add
does not depend in any way upon the indiyidbility of its formula^ but solely upon its
possession of certain specific characters ; and the examination of the properties of oxalic
add soon shows us that its molecule must be represented, not by the more simple mono-
basic^ but by the more con^lex dibasic formula. In jfact the same dass of chemical
reasons which induce us to regard water as dihydric, must also induce us to regard
oxalic add as dihydric, and so in other instances. Inasmuch as the modes of dis-
tinguishing between monobasic, dibasic, tribasic, and tetrabasic adds haye been
minutely set fbrth in the artide Acids, it is unnecessary here to repeat them. We
will cniy observe that certain special adds, to the properties and metamorphoses of
which we shall presently haye occasion to adyert, are proved by their specific charac-
tefs to be dihydric and dibasic, namely :

Carbonic add H*C*0»««'

Oxalic add H»C»0<««

Sulphurous add H*S*0*«*

Sulphuric add H*S*0*'«*

We will now torn our attention to the atomic weights of the four elements with
which the hydrogen of the four primary hydrides, whose atomic weights we haye con-
sidered somewhat minutely, 4S combined ; whereby it will appear that the quantities of
carbon, nitrogen, oxygen, and chlorine which we haye represented by the symbols
O , K« , O* , and Clf , respectiydy, constitute the atoms of these dements, or the
smallest individble proportions of them which can enter into chemical combination.
To hcfjai with carbon: we wish to prove that 12 parts of that element, or the
quantity thereof which combines with 4 parts of hydrogen to form mkrsh-gas, is
the smallest proportion of carbon that can exist in a compoimd. We find in the
first place that the quantity of carbon contained in the great migority of carbon-com-
pounds must necessarily be represented by 12, or some multiple of 12 parts. We may
adduce in illustration of this position, the primary series of homologous fiitty adds and
their sodium-salts.

Formic . C»«"H«0««* C'xmh NaO*«« . Formate

Acetic . C««"H*0*x* C'*"H»NaO'«« . Acetate

Propionic . (?«»H«0««* C» x "H» NaO' « « . Propionate

Butyric . 0*«»H«0««* O»"H»Na0«x« , Butyrate

Valeric . C*»"H"0«x* C»«»»H»NaO»xt . Valerate

Caproic . C^^^H^O^** C«>cMH"NaO«'«« . Caproate

The ratio of carbon to hydrogen in the sodium-salts, necessitates our expressing
tlie constituent carbon as a multiple of 12. The mere ratio of carbon to hydrogen in
the adds, would allow the carbon, in all of them, to be expressed satis&ctonly by
nnmbers whidi are not multiples of 12, but of 6. Valeric add, for instance, might be
represented by the formula (>>< "HK)*; but the circumstance that one-tenth part of its
hydrogen can be displaced by sodium preyents the possibility of our halyiuff the
hydrogen in its molecule, and consequently of our reducing its carbon ^m a mmtiple
of 12 to a mere multiple of 6.

From the drcumstanoe that all carbon-compounds must be represented with 12
parts, or some multiple of 12 parts of carbon, it follows that wheneyer two compounds
c^^ from one anotner by the different proportions of carbon which they respectiyely
eontain, that difference amounts to 12 parts of carbon, or to some multiple of 12 parts.
Thns, wood-^pirU consists of 16 pts. of oxygen, 4 pts. of hydrogen, and 12 pts. of
carbon, whereas in aldehyde we haye another 12 parts of carbon, and in acrolein two
other 12 parts of carbon in addition, so that the three bodies may be represented by
the respectiye formulae :

Ci»t«H<0' Wood-spirit

OkwH^O* Aldehyde

C"»>«H*0' Acrolein

460 ATOMIC WEIGHTS.

We axe not ftoqnamted with anj bodies intermediate in composition b^ireen wood-
spirit and ald^vde^ or between aldehyde and acrolein, nor hare we an/ roaaoin to
anticipate their formation at any fntore time. Again toluene contains 8 parts of hydrogen
united with seven times 12 parts of carbon ; whereas einnamene contains another 12 parts
of carbon, and naphthalene three other 12 parts of carbon in addition, thus :

C"«"H» Toluene

0"'«"H' Ginnamene

C»xwH" Wanting

C»««H« Naphthalene

Now the probability amounts almost to a certainty that a hydrocarbon intennediate
between einnamene and naphthalene will be discovered, and that a hydrocaiban into^
mediate between toluene and einnamene, or between einnamene and the expected com-
pound, or between the expected compound and naphthalene will not be disooveivd. It
follows also that when carbon, plus some other element or elements, is added to or
taken from a body, the quantity of carbon added or subtracted is always 12 parta^ or
some multiple of 12 parts. ThoB the molecule of eadium^thyl absorbs 12 ports of
carbon, plus some oirgen to form propionate of soditim; aeoniiie aeid^ by the loos of
12 parts of carbon, pius some oxygen, becomes citraoonieacid; and phthaUe acid, by the
loss of twice 12 parts of carbon, plus some oxygen, becomes beieene. Moreover in
those series of compounds known as homologous, the quantity of carbon in eadi
successive member of the series increases by 12 parts, as shown in a preceding^ table of
the &tt^ acids and their sodium-salts. All chenusts recognise the fiaet, vliich is
indeed indisputable, that the smallest increment or decrement of carbon that can be
effected in a compound is 12 times as great as the smallest quantity of hydrogen
that can be introduced into or displaced from a compound ; so that if the entbe series of
carbon-compounds is to be represented by the simplest sati^actory formulae, the atom or
smallest combining proportion of carbon must be represented as having 12 times the
weight of the atom or smallest combining proportion of hydrogen. But some <*TMwtii**a
who from old association still accord to carbon the atomic weight 6, consider that all
carbon-compounds contain an even number of atoms of carbon, and that in the decom-
positions and recompoaitions of these compounds, two inseparable carbon-atoms are
always concerned. But if we understand tne smallest inseparable or indivisible pro-
portion of an element to constitute its atom, the conception of two insepanUy asso-
ciated atoms is clearly illogical. Two small atoms of carbon, having each the value
6, if they can never be separated from each other, must neceoessarily constitute one
large atom of carbon having the value 12.

There are two well-known compounds of carbon, namely, carbonic oxide, and car-
bonic anhydride, which may possibly be regarded as constituting exeeptions to some
of our previously made assertions. Thus the molecules of these two bodies may be
represented by one or other of the following pairs of formulae :

C*"* 0I«" Carbonic oxide C'»** 0>«'«

Qix«o»«« Carbonic anhydride cikhq**"

Now provided we recognise the dibasicity of the carbonic, oxalic, and other similar acida,
as their chemical properties require us to do, it is quite certain that a proportion of either
carbonic oxide or carbonic anhydride, containing only 6 parts of carbon, is incapahle
of effecting or of resulting from a definite chemical reaction. Carbonic anhydride in
particular, is a very frequent product of chemical action, but in no definite decomposi-
tion do we ever obtain a smaller proportion of the gas than that represented by 12
parts of carbon plus 32 of oxygen. A few illustrations are appended of the formation of
carbonic oxide and carbonic ^hydride, from the decomposition by heat of three mono-
basic acids, namely, the formic, acetic, and benzoic ; of two dibasic acids, namely, the
oxalic and tartaric ; and of one tribasic acid, namely, the aconitic^ the decomposition
of which last has been before referred to.

Formic acid . C^^^HW** = c»«"0'«* + HH)

Acetic acid . C'^^H^O'** « C>x»«0»»« + C>««H«

Oxalicacid « cixiih*0*«' « C'>«"0>«* + C*" 0*«* + IPO*

Benzoic acid . C'^^HW**' - C'*"0« «* + C««"H«

Tartaric acid . C*«"H«0««' - c»*»»0««* + C»«"H*0««* + H«0*

Aconiticacid . C^^^HH)*** « QixuQt km + C'^HH)*"*.

With regard to nitrogen, all chemists are agreed that 14 parts of that elemoit,
or the quantity thereof which combines with 3 parts of nitrogen to form ammonia, is
the smallest proportion of nitrogen that^ can exist in a combination. We find that the
quantity of nitrogen contained in the great minority of nitrogenous compounds, in-
duding all salts of ammonia and of organic alkaloids, must neoessarily be represented

ATOMIC WEIGHTS. 461

by 14 putfl^ OF Bome multiple of 14 parts. AmoDg mifloellaiieoiui bodies we may
■ddnoe cjanogen, indigo, and nitric acid, each of which contains 14 parts of nitrogen ;
iirea» aspanigin, and ^lysammic acid, each of which contains twice 14 parts of nitro-
gen ; creatine and oarbazotie add, each of which contains three times 14 parts of
nitrogen ; uric add and caffeine, each of which contains four times 14 parts of nitrogen,
&C. £e. "Etma the drcnmstance that all nitrogenous compounds mnst be represented
wiUi 14 parts of nitrogen, it follows that whenever nitrogen is liberated by a chemical
reaetioii, and whenerer nitrogen plus some other element is introduced into a chemical
oompoond, tiie quantity of nitrog^ concerned must be represented by 14 parts or some
iMiHiplft of 14 parts. Thus by the action of nitric add upon the hydrocarbons, and
i^on a great variety of other compounds, we can introduce into the compounds 14 parts,
or twiee 14 parts, or three times 14 parts, &c &c. of nitrogen, whereas we cannot
introdnce any intermediate proportion. Again, when sal-ammoniac is decomposed
Vy chlorine^ fbr eveiy molecule of the salt decomposed, 14 parts of nitrogen are
fibearated; and when nitrate of ammonia is decomposed by metallic zinc, for eveiy
nolefnln of the salt decomposed twice 14 parts of nitrogen are liberated;
and so on. There are a few bodies formed on the type of one or more atonts of am-
monia, in which the ratios of the constituent dements might be satisfactorily expressed
br temnlsB in which the quantity of nitrogen represented was not a multiple of 14.
IjiQs t rimer enramine might be represented by the formula N'^^'^Hg, and tri-
ethylamine^ by the formula N^ * *'*C4i*. Similarly, all deriratiTes of ammonia in
wliidi the whole of the hydrogen is displaced by one and the same metal, hydrocarbon,
or halogen, mif ht be represented by foxmuls in which N m 4*7 ; which formulsB
maretfTcr, would be more simple than those in which N » 14. But the same dass of
rsaaoM which induce us to represent the molecule of ammonia with 8 atoms of
hydrogen, indnce ns to represent the molecules of these bodies with 8 atoms of
metal, radide^ or halogen. Thus triethylamine is the third of a series of compounds,
namd^, N»«»«HXC»H»), N» « "H»(C«H»)« and N> « >XO«H»)«, obtained succesdvel^ by
a rontin^anfi^ of the same reaction. Moreorer, a quantity of triethylamine contaming
leas than 14 parts of nitrogen, is not suffident to effect any decomjpodtion, or to
combine with the molecule of any add or salt. It is observable tiiat the entire series

of oompounds is represented most simply by formulse, in which N tm 14, although one

particiilai

N-47.

ticoiar member of the series may be represented most simply by a formula in which

Let ns now direct our attention to oxygen. We wish to show that 16 parts
of that dement^ or the quantity thereof which unites with 2 atoms of hydrogen to
form water, is the smallest proportion of oxygen that can enter into a combination.
We find in the first place that the quantity of oxyeen contained in the great minority
of definite oxidised compounds, must necessarily be represented by 16 or some mul-
tiplBof 16 parts. Thus the molecules of all hydrates, double oxides, acids,
oxisalts, aldehydes, ketones, alcohols, oxacid-ethers, and a great number
and Tariety of other compounds, doubtiess forming to|;ether 99 per cent, of all known
compounds of oxygen, cannot be represented save with 16 parts, or some multiple of
16 parte of oxygen. Por example^ the molecules of hydrate of potoMium^ henzoio
aldehyde, acetone, ckhral, hypochlorite of sodium, &c &c each contein 16 parte of
oxygen. The molecules of tptnelle, browti'hamatite, camphor, heneiie, acetate of sodium,
henMoie acid, &e. &c. each contain twice 16 parte of oxygen. The molecules of nitric
aoid, ylyeerin, chlorate of potassium, salicylic acid, augiU, &c. &c each contain three
times 16 parte of orfgen. The molecules of phosphate of sodium, perchloric ether,
gmnst, olivine, sulpS^nie acid, &c ^. each contein four times 16 parte of oxygen.
The molecules of starch, acid malate of lead, nitrosalicylic acid, &c &c. each contain
fiye times 16 parts of oxygen. The molecules of mannite, cream of tartar, &c ^ each
contain six times 16 parts of oi^gen, while the molecules of citric acid, pyrophosphate
of copper and sodium, &;& &c contain each seven times 16 parte of oxygen, and so on.
From the dreumstance that nearly all oxidised compounds must necessarily be repre-
sented with 16 or some multiple of sixteen parts of oxygen, it follows that when two
bodies differ from one another in composition by the different proportions of oxygen
which they respectiydy contain, that difference amounte to 16 parts or some multiple
of 16 parte of oxygen, as is well seen in the two following series of bodies.

KCl Chloride of potassium OH* 'Ethylene

XOiOiKM Chloride of of potassium C«H*0»«'« Aldehyd

KC]0*">* Ihrpochloritoofpotasdum C^iO""** Acetic add

KaO««'« Chlorate of potasrium C»H«0«*w Glycolicadd

KC10«"*< Pecchloratoofpotasdum CH^^"*!* Glyo:^lic add.

It foDowa idflo that the quantity of oxygen which can be liberated by any reaction, and
wtdcfay either alone or together with some other dement^ can be aoded to^ subtracted

462 ATOMIC WEIGHTS.

from, or displaced in a oompoond, must be 16 or some multiple of 16 partSL Nov
'why this should be unless the 16 poits constitnte an indiTisible proportion or chemical
atom, is quite inoonoeiyable. We may adduce the following illustzatums. Bach
molecule cSt nitrate of sodium decomposed by heat into oxygen and nitrite of sodium,

E' ^ ^ 1 16 parts of oxygen, l^ush molecule of permanganate of potassium, deooaiposed
Iphuric acid into oigrgen and mansanese-alum, yields twice 16 parts of oajgeu.
molecule of chlorate of potassium decomposed by heat into oxygen and dilofide
of potassium, yields three times 16 parts of oxygen. Each molecule of pentachloride
of phosphorus, oonyerted by treatment with water into phosphoric chlordldehyde and
hyorochloric acid, acquires 16 parts of oxygen in exchange ror an equiTalent qnantilT
of chlorine. Each atom of alcohol converted into aldehyde by oxi<uition, reacts with
16 parts of ox^fgen, and each atom of aloc^ol eonrerted into acetic acid by oxidatioo,
reacts with twice 16 parts of oxygen. Each molecule of bvomacetie acid, oonTetted by
the action of water into glyoolic acid, acquires 16 parts of oxygen and 1 part of hydro-
gen, in ezchan^ for one atom of bromine. Each atom of b^oiiene^ oonTuted by treat-
ment with nitnc acid into nitrobenzene, acquires twice 16 parts of oxygen, and 14 parts
of nitrogen, in exchange for one atom of hydrogen, and so on. But precisely as there
are some nitrogeniaed bodies which with the atomic weight of nitrogen » 4*7, may be
divided into thirds, and can thus receiye simpler formula than with the atomic wu^t
of nitrogen » 14 ; so are there some oomparatiyely few oxidised bodies which, with
the atomic weight of orygen ■■ 8, may be divided into halves, and can tiius reooLTB
simpler formula than with the atomic weiffht of oxygen a 16. We have seeoi, how-
ever, that if the comparable molecules of mtrogenised bodies were camddj fononlated
they would all be represented more simply by formule in which N « 14, than by
formuliB in which N — 4*7 ; so it will appear that if the comparable molecDlea dT
oxidised bodies were correctly finmulated, they would all be represented more siniply
by formula in which O «• 16, than by formula in which 0^8. Those oxidised
bodies in which the ratio of the o^gen to the otiber constituents csn be satisftciarily
expreased by assigning to the oxygen a numbor which is not 16 or a mult^ile of 16.
but only 8 or a multiple of 8, comprise most compounds in which the oxygen is united
with one kind of matter only, including all the simple metallic oxides. 'Das in water
and lime, the ratio of the constituent oxygen to the hydrogen and calcium raspeetiTdly,
is as satis&ctorilv expressed bv the formula 0*^11, and O^ '*'Ga, as by the finmnte
Qi X i<£[«^ and 0^ '^ **Ca*. The only question is, which of these pairs of formula represents
the molecules of the two bodies. Now it is no more necessary to argue the point whedier
O' >^ *Ca, is the correct e3q>ression for the metallic oxide, lime, than it was to argue the
point whether N* ** ^''Hg, was tibe correct expression for the metallic nitride, mercnr-
amine.^ The accordance of a trihydric formula to ammonia, necessitates the accordance
of a trimetallic formula to mercnramine^ and in a precisely similar manner, the acooid-
ance of a dihydric formula to water necessitates the accordance of a dimetallic fimnula
to lime. It may be observed, moreover, that many strictly comparable reactions can be
effected by means of water, hydrate of calcium, and lime resp^tivelv, and that in these
cases the quantities of the reagents can only be expressed by the formula O* " ■*HH,
QI X i*HCa, and 0^ '^ **CaCa. Again, in bodies analogous to ordinaiy ether and the
homogeneous anhydrides, the ratio of the oxygen to the other constituents may be
satisfactorily represented by formula in which the proportion of o^gen is expreased by
8 parts only. Thus ether may be represented by the formula 0* '^"El, and bensoic
anhyd ride by the formula 0* * *Bz ; but all arguments founded on mode of formation,
on reactions, on vapour-densities, on seriated position and properties, &c. tend to show-
that the above formula are not correct expressions of the molecules of the bodies
represented, which, Hke that of water, contain 16 parts of oxygen. Thus, ether is ooe
of the following series of bodies: 0*"*'H£t,ethyhiteofhydiogen, or alcohol; O'^'^'MeEk.
ethylate of methyl; 0'x'«EtE^ ethylate of ethyl or ether; 0»«'«PrEt, ethylateof
nropyl ; and benzoic anhjrdride is one of the following series : O* xmh£^ beuoate of
hydrogen, or benzoic acid; 0'><**BzBz, b^izoateof benzovl, or benzoic anhydride;
O' * "AcBz, benzoate of aoe^l, or aoeto-benzoic anhydride ; Sec &c Lastly, in cotain
dibasic acids and their salts of one metal, the ratio of the ozrgen to the other con-
stituents may be satisfactorily expressed by monobasic formula, m which the o^gen is
expressed not as a multiple of 16, but as a multiple of 8. Thus sulphurous acid and

sulphite of sodium may be formulated as follows : HS^O* « ■, and NaSTO* * •, re^iee-
tively. But as we have before observed, the distinctions between monobasic and di-
basic acids and their salts are very decided ; and inasmuch as these adds and salts are
indisputably dibasic (see Acms), their molecules cannot be oorrecStly represented by
monobasic formula. The simplest dibasic formula for carbonates, sulphites, and sul-
phates respectively, are the following, in which the proportion of oxygen is necessarily
expressed as a miutiplo of 16 parts :

ATOMIC WEIGHTS. 463

HKJO»*" H«S*0»«w H?S»0*«"

CSftHCO««" NaHS-0«»" KHS'0*«"

. CaHW" Na«8*0»«" K«S»0*«»

MgCaCO*"** NH<NaS*0»«w NiES'0^>(>«

Many chenuBta, who acknowledge that the molecule of water consists of 2 parts of
hydrogen nnited with 16 pts. of oxygen, and that, in ninety-nine cases out of a
hundred, the smallest qnantily of ozyven that can enter into the composition of a well-
defined molecale must be represented by 16 parts, prefer, from old association, to
leeord to ooqrgen the atomic weight 8, and to admit that all oxygenated molecules
contain two inseparably associated atoms of oxygen, or some multiple of two inseparably
associated atoms. Thns, they represent water by the formula H'O* " * instead of HH),
and nitric add by HNO* ^ ' inst^ of HNO*, &c This practice is evidently most
inconsequent: for the conception of two inseparable proportions of 8 each, amounts
after all to that of one indivisible proportion of 16, that is to an atomic proportion of
16. To be consistent, we must represent the molecules of hydrochloric acid, water,
ammonia, and manh-gas either by Gerhardt's atomic, or oy Dalton*8 equivalent
fimnnlaei thus:

^(jimn-ft Hydrochloric acid HCl"*"'*

HK)>»" Water H0»»«

H^»«" Ammonia HN»«*'»

H<C> « » Marsh-gas HC» « «

ezeqpt that Dalton took, not marsh-gas, but olefiant-gas, for his standard hydrocarbon,

and aecorded to it the formula HC* ^ \ whereby maish-gas became H'C* ^ '. Now-a-

days we know that the molecules of marsh-gas and olefiant-gas both contain the same /, ^ ^ '

nomber of hydrogen-atoms, and that their formulse are 0* '^ ^"H* and C ^ '*H* respec-

tiTely.

With regard to chlor in e, all chemists are agreed that 35'5 parts of that element, or
the quantity thereof which unites with 1 part of hydrogen to form hydrochloric add, is
the smallest quantity of chlorine that can enter into a combination. We find that
36*5 parts of dilorine are capable of directly displacing 1 part of hydrogen in a great
variety of compounds ; that in all well defined molecmes, the quantity of constituent
chlorine must oe represented by 35'6, or some multiple of 35*5 parts ; that whenever
two bodies differ from one another in composition by the quantity of chlorine they
lespectavely contain, the difference amounts to 35*5, or some multiple of 35*5 parts ;
ana that it is impossible to add to, subtract from, or displace in any compound a pro-
portion of chlorine which is not represented by 36*5, or some multiple of 36'5 parts.

In the course of the preceding observations, reference has occasionally been made to
the principle of analogy as a guide in determining the molecule of a compound body,
and the atomic weights of its constituent elements. Thus we have referred to the
ansJiOgy of triethylamine with ammonia^ and to that of lime or oxide of caldum with
water or oodde of hydrosen. But, in addition to the arig^uments already used, we
Aaj show more especially that the prindple of analogy is in &your of the atomic
weigbts and molecules which we haye adopted. Thus the indisputable analogies of
mtroua add, mtrie add, and peroxide of nitrogen, with chlorous acid, chloric acid,
and peroxide of chlorine respectively, are shown yery dearly by formulae in which
K ■- 14, whereas they would be concealed by formuuB in which N -■ 4*7, as seen
below:

Chlorous add, HCIO* HNO* Nitrous add HN*0'

Chloric add, HCIO* HNO« Nitric add HNK)«

Perchloric oxide, CIK)* NH)« Pernitric oxide N"0«

Again, with the molecule of water *■ 9, the relation of water to the alcohols as the
undoubted vanishing term of the series, would not be manifested as it is with the
molecale « 18. Thus, if we write alcohol CH*0* ^ \ wood-spirit CH«0' "* * and water
HO' " *, the reUtion of water to the alcohols does not appear, but in the following
aeries of ibrmulsB with 0 « 16, it is peifectiy apparent :

OWK), Amylic alcohol CHK), Ethylic alcohol

C*H'^,BntyUc „ CH«0, MethyUc „

Cff O, Propylic „ H*0, Hydrio „

The rdation of water to the alcohols, as shown in the above formulae, is not a mere
pi^er relation, but has its fbundation in experiment. When water and alcohol re-
spectiyely are acted upon by potasnum, by chloride of benzoyl, by pentachloride of
pnosphorus, and by a host of other roagents, the reactions are acknowledged by all to
DC ptedaely dmilar. All chemists, no matter what the formulse they emph>y, recognise
the fact that the quantity of water which in a reaction corresponds to one proportion
of aloG^l, must contain two units of hydrogen. Similarly, with regard to hydrated

464

ATOMIC WEIGHTS.

bases and adds. The reactioiui of the bodies dearly show that the quantity of water
whidi corresponds to one proportion of hydrate of potasainm, or of hypoddorons add,
for instance, mnst contain two nnits of hydrogen. If we write hydrate of potaasiiuii
KHO'**' hypochloioiis add HGIO^''* and water HO* "• the formnhe do not repre-
sent comparable quantities. But, in tlie following series of fonnulsB with O -* 16, the
relations of the bodies are rendered perfectly erident :

KEO, Oxide of potassium HCIO, ^podilorous add

KBO, Bhrdrate of potassium CICIO, ^ypochlorous anhydride

HHO, Water KCIO, Hypochlorite of pc^taasium

Moreover the prindple of analogy is frequentljr allowed to oyerrule all other eon-
siderations. Thus the smallest quantity of aluminium that can enter into a combi-
nation is 27*5 tunes as great as the smallest quantity of hydrogen. This auantity of
aluminium, like 14 parts of nitrogen, is capable of uniting with 3 atoms of chlorine, and
of its representatiyea. But, from the strong analog existing between aluminic and
ferric compounds, the atomic weight of aluminium is fixed at 13*75, in order that its
compounds may be represented by formuls which, though more complex than those
with Al B 27*5, are in accordance with the formulse of conesponding ferric compounds,
thus:

Fe«Cl«,

KFe«(SO*)» . 12H»0,

HFe«0«,

Ai«a«,

KA1«(S0«)« . 12H«0,
HA1K)«,

Sesquidiloride of iron
Iron alum
Brown haematite
Sesquichloride of aluminium
Common alum
Diaspore

The prindple of analogy frequently enables us to determine satis&ctQrily the
molecules and atomic weights of bodies with which we are comparatirdy but KtMe
acquainted. Thus the anidogy of selenium and tellurium compounds, in so far as they
are known, to the well-known compounds of sulphur, requires us to give similar
formulsB to the similar compounds of all three dements. With regard to sulphur
itself, precisely the same reasons that induce us to represent water by the fbfrmula
HH), and to accord to oxygen the atomic weight 16, must induce us to renreseiit sol-
phydric acid by the formula H*S, and to accora to sulphur the atomic weight 32. But
even if our acquaintance with sulphur were much less intimate than it im, staU. the
analogy of its best known compounds with those of oxygen would suffice to allow of a
satisfactory determination of its atomic weight. The prindple of analogy induces us
to accord to the primary hydrides and chlorides of the more or less electzonegatiTe
elements, the following formulae, and to classify them in four prindpal groi^ thus:

Triatomic.
H^
H»P
H*As
H«Sb

a*N
a«p

CPAs

Cl«8b
Cl«Bi

The followingtable represents the atomic weights of the dementaiy bodies ob the
hydrogen scale (H » 1) as determined by the preceding considerations. Those on the
oxygen-scale (0 * 100), which are now but little used, may be found by multiplying the

hydrogen-numbers by -r^ or 6*25. The actual determinations of the atomic w&fjai»

are given, with the methods of quantitatire estimation, under each element.

Moni^omic.
HF
HCl
HBr
HI

CIH)

Tetratonic
HH)
H<fli

CIH)
Cl^

Cl'Sn

Tablb

OF Atomio Whiokts.

N«me.

Sjm-
bol.

Atomic
Wdfht.

Fonnola of Compoood
analyiad.

•

Acoordlnc to Bipcii-
■MBttby

Alumiaium . •

Antimony

ArMolc ....
Barlam . • . .
BIsmatli • . • t

BofOD ■ • • •

At
Ba
Bi

1376
ISO'S
ISS

68*6
210

Chloride of alumlnlom, APGl*
Triiulphldo, SMSS
Trlchioride, SbCl>
,, AsCls
Chloride, BaCl
„ BiCP
/Boric anhydride, B<0>
1 M chloride, BCP

Dumas.

Schneider.

Dumaa.

Peloose, BeRcHau

Marignaib, Paloese.

Dmnaa.

BeraeUni.

Dansf.

ATOMIC WEIGHTS.

465

Tablb conHnued,

Nabm.

BnmhM .
Cadalam •

Klobiam

Gold

Sym-

tN>L

O&ffACII

PaOMlloB

Sll^

Br
Cd
Ck

Cr
Co

Cb
Cu
Dl
K

Au
U

I
Ir

U
Pb

Mn
Hg

Rh
Rii
So

81
Ag

N«

Tk
To

Tr
Th

Atomic
Wolgbt.

{

80
M
90

S5*5

96S
»5
976
«|-7
48

4-7
7-0
196
1

127
986

{

46
108*6

6*5

7-0

97-6
100

( 48
f S9
\ 99ft

14
100

89*9
59
69
79

29
108

43*8

87*6
198

59-6
rll6
1118

68*6

{

82-5
8S-6

89 !V

Formula of Corapoood
analysed.

Bromldo of potaulttm, KBi
Ozido, Cd*0
Lima. Ca«0

Carbonic anhydride, CO>

Cerous oxide, Ce*0

! Chloride of potassium
,. „ silter
Chromic anhydride, Cr^O^
Chloride, CoCl
Tetrachloride, CbCl*
Cupric oxide, Cu*0
Oxide, Di<0

f Fluoride of caldnm, C«F
I „ „ sodium, NaF
Gludna,GIS0 \
- G1<0» i
Auric chloride, AaCP
Water, WO

f Iodide of poUssinm. KI
I „ „ silver. Agl
Bichloride, IrCl*

f Ferric oxide, Fe«0>

{

^ Ferric chloride, FeSCP
Oxide, La*0

n WO

« Lt«0
Carbonate. LiSCO^
Sulphate, Li>SO«
r Magnesia, Mg*0
I Chloride, MgCl
MoCl
Mffreorlc oxide, Hg*0
Molybdic anhydride, Mo'O*

Oxide, Nl*0
Chloride, NiCl
Sal-ammoniac NH^Cl
Dichloride, OsCl«

Chloride, PdCl
/ Phosphoric anhydride, F>0*
1 Pentachloride, PCI*
Dichloride. PtCl*
Chloride, KCl

ScMiuichloride, Rhsci*
„ Ru«CI»
Selenide of mercury, Hg*Se

Chloride, Sia^
n AgCl

M NaCl
SrCl

! Cinnabar, Hg>S
Sulphide of sllTer, Ag*S
Tetrachloride, TaCH
Bromide of potessinm and tel*
lurinm, K>TeBi4

Thorina, Th'O
Stannic oxide, SnO*

„ chloride^ SnCH
Tetrachloride, tlCl^
Tnngstlc anhydride, W>0*
Uranlc oxide, U«OS
Vanadic anhydride, V^O^

Oxide, Zn<0
Zlrconla, Zr^O^ i
ZrO« r

Aoeq^ng to Experi<
ments by :

Marienac.

Von Hauer.

Erdmann and Marchand.

f Dumas and Stas.

i Erdmann and Marchand

Marignac, Hermann.

Marlgnae, Penny ; Mau-

men£, Berielius.
Dumas.

Piligot, Berlin.
Dumas.
H.Rose.

Erdmann and Marchand.
Marignac

Louyet.
Dumas*

Awdcj

Levol, Renelius.
Dumas { Erdmann and

Marchand.
Bfarignac.
Dumas.
Bersellus.

iSvanberg and Norlln.
Maumen£, Erdmann and
Marchand.
Beraellua.
Dumas.
Marignac
Bersellus.

Troost.

Mallet.

Bersrlius.

Dumas.

Bersellus.

Erdmann and Marchand.

Sranberg and StruTe;

Berlin.
Dumas.
Schneider.
Dumas.

Pelouse, Marignac, Penny.
Bersellus, Frany.

Beraelius.

Schrfitter.

Dumas.

Bersellus, Andrew*.

Marignac, Frfany, Man-

meut.
Stas.

Bersellus.
Claus.
Bersellus, Saoc, Erdmann

and Marchand.
Dumas.
Marignac, Maomen^

Penny, Bersellus
Penny, Pdouse, Dumas.
Dumas.
Erdmann and Marchand.

StruTe,
Dumas.
H. Rose

T. Hauer.

Bersellus.

Mulder, Vlaanderen.

Dumas.

Pierre.

Schneider, Birdi, Dumas.

P^llgot.

Bersellus.

A. Erdmann.
Bersellus, Erdmann.

We will now tuni our attention to the determination of atomic weights from
pb/sical connderationt, and obeenre how far the weights deduced from physical and
ebemii'al conidderations coincide with one another. In the first place then, we will diB-

VoL. L H H

a - 35-5

0-16

100

Br « 80

S r. 32

I - 127

8e- 79-5

466 ATOMIC WEIGHTS.

CUBS the combining Tolumes of gases and Tapours; trom the obserymtion of
which we deriye the most important of all means for controlling our oondnsions as to
the atomic weights of volatile bodies. If we take the specific gravi^ of hydrogen gas as
unity, we find eiperimentally that the specific gravities of most omer elementaiy gases
and vapours are represented by the numbers we have selected to express their atomie
weights. Hence, these atomic numbers represent the weights of equal volumes of
the respective gases and vapours ; and the formula of a compound body shows the
number of elementary volumes of which it is composed. Thus while the formula for
nitric add HNO' represents a compound of one part of hydrogen, fourteen parts of
nitrogen, and three times sixteen parts of oxygen, it also represents a compouna of one
volume of hydrogen, one of nitrogen, and three of oxygen. The relative spedfie
gravities of the following elements, when in the gaseous state, and exposed to the
same pressure and temperature, have been ascertaiuM to be respectively :

N « 14

P « V

Hydrochloric acid gas is composed of one volume of hydrogen, and one volume of

chlorine united without any condensation. Consequently the molecule of hydrochloric

add is represented by two volumes of gas aH t whilst the atoms of hydrogen and

chlorine respectively are represented hj one volume only Q. Hence whQe the

spedfie gravity, or weight of a unit of volume of chlorine coinddes with its atomie

weight, Sie specific gravity or weight of a unit of volume of hydrodiloric add coiB-

1 4- 36*6
ddes with the half of its atomic weight, b 18*25. Now ninety-nine pa cent.

of all known volatile compounds agree with hydrochloric add in this paiticnkr,
namely, that their specific gravities in the gaseous state are the halves of their atomie
weights. Thus the atomic weight of water H*0* « ", being 18, one volume of steam
is found to be 9 times as heavy as one volume of hydrogen. The atomic weight of
ammonia, H'N* * ", being 17, one volume of ammoniacal gas is found to be 8*5 times
as heavy as one volume of hydrogen. The atomic weight of marsh-gas, HK)*^",
being 16, one volume of the gas is found to be 8 times as heavy as one volume of
hydrogen, and so forth. Inasmuch, therefore, as half the atomic weight coinddes
with the specific gravity, or weight of one unit of volume, the entire atomic weight
must represent twice the specific gravity or the weight of two units of volume ; a con-
clusion which may be confirmed by actual experiment Thus one volume of oxygen,
and two volumes of hydrogen at me temperature 100° 0. can be converted into two
volumes of steam at the temperature 100°. Again two volumes of ammonia, when
decomposed by the transmission of a series of dectric sparks, yield one volume of
nitrogen, and three volumes of hydrogen. No matter what the number of atoms or
volumes which enter into the constitution of any volatile compound, they all become
condensed into two volumes, as shown by the fact that the specific gravity or vapour-
density of the compound is the half of its atomic weight.

Seeing that the molecule of a compound body corresponds with two volumes of gas
or vapour, and the atom of an element with but one volume, it is evident that the
quantity of an element which is strictlycomparable to the molecule of a compound body
must be represented by two atoms. Hence the symbols jhThT, |H| ci|, and fajp',
represent comparable quantities of the thr^ bodies, hydrogen, hydrochloric add,
and chlorine respectively which, thus formulated, present an obvious relation of
sequence to one another. By the molecule of an element, therefore, ire invariably
understand two atoms or two volumes ; and there is great reason to^ believe that oor
acquaintance with the uncombined elements pertains exclusively to their molecoles.
So that while CI, for instance, represents the atom, or smallest proportion of chlorine
that can enter into a combination, CI' represents the molecule or smallest proportion
of free chlorine that can result firom or effect a reaction. There are certain com-
pound molecular groupings also, which like the elementary molecules, ooeupy two
volumes when in the free state, and become halved in combination. Thus ethyl in the
free state is represented by C^H'* » DO, in the combined state by C* H* — U, and
so in other instances.

It is evident from the preceding observations that, in the great nunority of instances,
the molecules we have deduced from chemical considerations, are identical with the
molecules deduced from the phvsical law of gaseous volumes enunciated by Amp^,
namely, that all gases contain tne same number of molecules within tiie same volume.
But if we had represented water by the formula HO' '^ *, sulphydric add by' the
formula HS^***', and carbonic oxide bv the formula C*"'0'**, we should hara
represented their molecules as having only half the volume of the molecule of hydro-
chloric add, and should consequenUy have violated Amp^'s physirail law. The

ATOMIC WEIGHTS. 467

gieneral eoocIiurioziB at wldeh we have arrived, however, namely that the chemical atoms
of elementary bodies oorrespond with one gaseous volume, and the chemical molecules
of toBipLe or compound boues, with two gaseous volumes, is quite in accordance with
physical requirements. Nevertheless there are some exceptions, real or apparent, to
which we must now direct our attention. We may premise l^ saying that some
chemists attach so great an importance to the law of volumes, that they would be
guided exdnsivelv by it^ and would accord to all bodies whatsoever, such atomic
weights as would be in accordance with it. In the present state of knowledge, however,
it seems to us preferable to deduce the chemical atom or molecule of a body chiefly
from chemical considerations, and to wait for further investi^tion to clear up the few
«iw>mali<*s which at present exist between the results of chemical and physical inquiiy.
Certain apparent exceptions to the law of volumes have of late years been satis-
factorily explained away, by having regard to the following habitudes of volatile
bodies. In the first place, some vapours, at temperatures but little raised above their
condensing points, have anomalous densities which are much too high, or, in other
words, the vtilnmes of their atomic proportions are much too small; whereas at higher
temperatures their densities and volumes are perfectly normal. Thus at a temperature
a little above its condensing point, an atomic proportion of sulphur vapour occupies
only ] the bulk of an atomic proportion of hydrogen gas at the same temperature ; but
at the temperature 1000^ C. the two atomic proportions .occupy the same volume.
Again the molecule of acetic add vapour at the temperature 230^ C. has the same
vofaune as the molecule of hydrochloric add gas at that temperature ; but at lower
temperatures, its volume decreases almost to one-half that of hvdrochloric acid gas at
the same temperatures. In reference to this property it mnkt be borne in mind that
Taponrs near their condensing points manifest vmations fiom several of the physical
laws aflacting gases. It wouhl seem, indeed, that a vajyour must be heated to a tem-
perature oonsi^rably above its condensiiig point before it acquires the properties of a
perfect gas. The recognition of this circupostance^ enables us to account in several
inatanoes for those departures from Ampere's law, in which the density of the gas is
too high. In the second place, several compounds at the high temperatures required
to bring them into a perfectly elastic state, seem to undereo a change, which has been
investigated by Kopp, Hari^iac, Deville, Hofinann, K6kul6 and outers, and has been
termed ditasnciatuMu According to these investigators, the molecule of a volatile
eompoond, when stronglv heated^ sometimes breaks up into two simpler molecules
which, on a reduction of tempen^re, reunite to form the original body, so that at
the temperature at which the density is taken, we are -really operating, not upon one
more complex, but upon two less complex molecules ; whence the densities are found to
oorreqiona with four volumes of vapour instead of with only two. The anomalous
Tohmies or densities of the following compounds have been explained in this way.

iVoU a Vols. 8 Vol*.

Sal-ammoniac NH«Cl - NH« + HCL

Sulphuric add H«SO* - SO* + H*0.

Pentachloride of phosphorus . . PCI* » PCI' + Cl<.

Hydrate of ethylendiamine . . . C»H»NK) « C«EPN« + H*0.

The phenomenon of disassodation then frequently enables us to explain various
departures from Ampere's law, in which the densities are too low ; or in which, in
other wcwds, the volumes are too great. But there still remain certain exceptions,
v^h, in the present state of knowledge, cannot be satii^actorily explained by either
of the above aescribed considerations. Thus the atomic volumes of the vapours of
phosphorus and arsenic respectivdy, ai« only one-half that of hydrogen. In order to
make their atomic weights correspond with their atomic volumes, the ordinarily re-
edv«d atomic weights would have to be doubled, whereby they would become 62 and
150 reepeetively. But this doubline of the atomic weights of phosphorus and arsenic
would be in violation of all chemical considerations, and likewise of all phvsical consi-
deratioiis except that .relating to the atomic volumes of the dements themselves. Thus
the formula for phosphamme would become P'^^H*, and that for arsenamine
^■itMiQc despite the analogy of the two compounds to ammonia NH*, and despite
the fbct that the hydrogen of the two compounds is divisible into thirds only and
not into sixths. Moreover the vapour^ensities of the compounds P^'^^'H* and
As^'^fH' would correspond to 4 volumes instead of 2, and would consequently be
in opposition to Ampere's law. Again, the atomic heats of phosphorus and arsenic
eonesponding to the atomic weights 62 and 150 respectively, would be twice as high
ss the highMt atomic heat of any other dement Lastly, by doubling the atomic
weufhts or arsenic and phosphorus, the isomorphism of certain comfwundS of ammonia
with the corresponding compounds of phosphamine and arsenamine would become
umitdligible. At present then we are forced to admit that the vapour^densities of the
dements, phosphorus, and arsenic, are anomalous, and that we are incapable of ex-'

Chloride of meicniy
Ethylide of meicoiy
Ethvlide of ssmc .
Meuiylide of zinc

468 ATOMIC WEIGHTS.

plaining the cause of the anomaly. It may be that the Taponn of these eLemeata,
like that of sulphur, though anomalous at one temperatnre, become aonaal tA a
higher temperature, though it must be admitted that the recent ezperimenta of DeTiIIe
do not countenance such an expectation. Or it may be that the anomalieB depend
upon allotropy. Phosphorus and arsenic are known to. exist in different aDo^opse
conditions, and it is not improbable that each allotropie form may hare a diffearent
atomic weight. Hence the anomaly might be explained b^ supposing tbat phoof^iar
mine, ibr instance^ contains the element phosehorosnm, haTing the atomic weipiht 31 ;
whilst phosphorus-vapour is composed of me element phoephoricnm, lupnng the
atomic weignt 62. This supposition of Tapour-allotropy might also serre to explain
the anomolous Tapour-density of acetic acid at a low temperature. Normal achate of
potassium has the formula CH'KO*, but {here is also an add-acetate haTing the
formula C^H'KO^ The small yapour-density might possibly represent an aeefde acid
corseapondinff to the former salt, and the lugh rapour-denaity an acetic acid coa»-
sponding to uie latter.

Certain other real or apparent exceptions to the law of volumes, are affisrded by tiie
chlorides and ethylides of zinc, mercury, and some other metals, as indicated below:

Hydrochloric add . . . HCl = 2 vols.

Hydride of ethyl

Cnloride of ethyl

HgOl - I vol. or Hg«Cl* - 2 rola.
HgEt „ „ „ HgfEt« „ „
ZnEt,, „ „ ZnTSt* „ „
ZnMe,, „ ., Zn*Me'„ „

In consequence of the anomalous vapom^densities of the molecules of these com-
pounds, as above expressed, some chemists have proposed to double the ordinarily
received atomic weight of the metals mercury and zinc, so as to represent the molecolea
of the above volatile compounds by the following 2-volume formulae ; and it must be
acknowledged that very strong reasons may be urged in favour of the dupUcafion :

Chloride of mercury .... Cl'Hg* « "•

Ethylide of mercury . . . Et»Hg»»*»»

Ethylide of zinc' .... Et*Zn»««

Methylide of zinc .... Me^n'*<"

It is admitted both by those who advocate and those who deprecate the proposal, fli»fi
the duplication of the atomic weights of the metals mercury and zinc, would neoecsi-
tate tiie duplication of the atomic weights of several other metals, induding magnesiiuii,
cadmium, lead, copper, iron, chromium, and aluminium. Now the prindpal objections
to the adoption of this proposal are the following. Firstly, because, although tbe
duplication of the atomic weights of the metals would bring the volumes of their
chlorides and ethylides into accordance -with Ampire*8 law, it would bring the VQlnmes
of the dements themselves into discordance therewith. Thus, the atomic vohunea of
mercuiy and cadmium corresponding to the atomic weights 200 and 112 remectiTely,
would each be twice as great as the atomic volume of any other dement. Secondly]
because the chlorides, oxides, &c, of these metals, which are ordinarily represented
as proto-compounds, would have to be represented as deuto-corapounds, thvs
HgCl*, ZnCP, CdCl', &c., a result not warranted by chemical condderations; seeing that
in their chemical properties, these compounds are quite undistinguishable from undis-
puted proto-compounds. Moreover, the adoption of these doubled atomic weights
would lead to most complex expresdons for very many compounds. Of course, if it
could be proved that the true atomic weights of these metals were really the doubles of
those ordinarily employed, the circumstance of the duplication leading to inconvoiient
formulae would have to be disregarded ; but in the absence of such proo^ the com-
plexity to which the condusion would lead is pro tanto eddence against the pioba-
biliW of its being true. Thus, phosphate of lead would become* Pb'^P'O' instead of

mercaptide of mercury would become Et'Hg"S* instead of EtHgS, 9ce. See,
Other exceptions to Ampere's law are furnished by the sesquiddoridee of aluminium,
iron, and chromium, the vapour densities of each of which, as determined by DeviUe^
correspond to one volume of vapour only, instead of to two volumes. Hence it has been
proposed to double the weights of the molecules of these compounds, and to represent
them by the formula Al^Cl*, Fe«Cl«, and WCl* respectivdy. But it is obeer^Ue
that if Uie molecule of sesquichloride of aluminium really contains 6 atoms of chlcnnev
it must also contain 55 parts of aluminium, and as a consequence, 55 parts of abuni-

ATOMIC WEIGHTS.

469

BimD win eonstitiite the smallest oombining proportion of the metal, or the smallest,
qnantitjT iriiieh errer exists in a combination ; in which case the smaUeet oombining pro-
poEtioa of ahunininm will haye twice the specific heat of the smallest combining propor-
tion of anj other element, a result that mnst throw considerable doubt upon the
praprietj ca the dumge on which it would be oonsequenK Again the rapour^ensi^
and chwniral relations of chlorochromic aldehyde alike show that its molecule must
be ggyreawwi br the fimnula GrH)K21'; while the correlations of sesquichloride of
chromium and eUorochromie aldehyde require the molecules of the two compounds to
be represented by Ibrmulas expressing the same amount of chromium, which would not
be the case if the sesquichloride were represented by the formula Cr*Cl*. There is,
moreoTer, another compound, namely, arBonious anhydride, As'O', the yapour-density
of which eoiresponds to only one yolume of yapour instead of two yolumes, although no
reason for the anomaly has yet been brought forward. There are also three well-
known compounds, the yapour-densities of each of which correspond to four yolumes,
instead of to only two, namely, nitric oxide, NK)*, pemitric oxide^ 1P0\ and perchloric
oxide, C1*0^. In its diemical relations, the molecme of nitric oxide, NK)', corresponds
to the moleenle of chlorine, Gl', and the atom of nitric oxide, NO, corresponds to the
atom of chlorine, CI : but whilst the atom of chlorine corresponds to one yolume, and
the noolecnle of chlorine to two yolumes, the atom of nitric oxide corresponds to
two Tcdumes, jind its molecule to four yolumes of gas, and similarly with pemitric
oxide and x)en!h]oric oxide. At present no satisfiictory explanation has been giyen
of these anomalie^ though it is not improbable that they may be explicable on
the prmciple of disassodation. Thus, it is possible that the atom of sulphurous
anhydride, (S"0)*, which, like that of oxygen, O , is capable of displacing two atoms of
hydrogen, would also, like the atom of oxygen, be represented hj one gaseous yolume,
were it not for the circumstance that the molecule of oxygen, 0^ cannot split into two
other molecules, whereas the molecule of sulphurous anhydride, SK)\ corresponding
thereto in equiyalency, can split into two separate molecules, each of which is capable
of occupying two yolumes ; and this relation of oxygen to the diequiyalent atoms of
solphurous anhydride, sulphuric anhydride, carbonic oxide, carbonic anhydride, &c.,
may be a parallel of the relation which subsists between chlorine and the prot-
equiyalent atoms of nitric oxide, pemitric oxide, and perchloric oxide respectiyely.

Out of many hundred yolatile bodies whose yapour-densities hays been ascertained, the
following table comprises all the well-known exceptions to Amp^'s law, though doubt-
less the strict chemical analogues of some of these bodies would also proye exceptional :

Synbol.

Vapour.

Atomic
weifht.

Tbeore-

tical
Tolume.

Actual
Tdume.

P
As

Phosphorus
Arsenic

P - 81
As -75

1
1

HgCl

HgEt

HgMe

ZnKt

ZnHe

As«0»

APCP

Fe»CP

Corrosiye sublimate
Mercuric ethyl
Mercuric methyl
Zinc-ethyl
Zinc-meuiyl
Axsenious anhydride
Ahiminie chloride
Ferric chloride
Chromic chloride

Hg -100

Zn -82-5

As -75
Al -1375
Fe-28
Cr -26-2

2
2
2
2
2
2
2
2
2

N«0«
CPO'

nhh:i

NH«CN

NH«.H.S

PC1»

C"H"*NK)

Nitric oxide

Pemitric oxide

Perchloric oxide

Sulphuric acid

Sal-ammoniac

Cyanide of ammonium

Sulphydrate of ammonium

Pentachloride of phosphorus

Hydrate of ethjlene-oiammonium

Hydmte of diethyl-^ thylene-diammo-

N - 14

a - 35*5
S - 16
N - 14
0-12
S - 82
P - 31
C - 12

2
2
2
2
2
2
2
2
2
2

mum

HB 8

470

ATOMIC WEIGHTS.

The anomalous Toliinies of the last seTen compoimds are dearlj explieable on the nm>
dple of disassociation. With r^ard to the duplication of the atomic weightB of &ose
metals whose chlorides and ethylides haye anonudons densitiefli it must be lemembered
that the proposal is at present yonng, and that farther investigation may gaffice to
remore some of the objections which at present soixonnd it ; precisely as fozther in-
yestigation remoyed the objections which in the first instance seemed to oppose with
oyerwhelming force, Chnrhaidt's proposal to double the then reoeiyed atomic wd^ts of
carbon, oxygen, and sulphur. This same remark applies to the proposal of Ctmusuo,
whidi we shall next haye to consider.

It was contended by Dulong and Petit, who were the earliest inyestigaton on die
subject, that all elementaiy atoms have the same capacity for heat, or, in other iwds,
that the specific heats of all elementary atoms are the same. If this hw
be admittea, it is obvious that the determination of the spc<^<i ^^^ of an elemest
must furnish a i«ady means of fixing its atomic weight. The atomic heats of simple
and compound bodies have been of late years ascertained with great care, ihoofjn fnm
the nature of the subject it can scarcely be said with great acearacy, by Regninlt,
whose results, corresponding to the atoms which we have adopted, are as foUows :—

Carbon •

82-5

Zinc

Cadmium.

13*75 Aluminium

Iron

29-6

Nickel .

29-5

Cobalt .

317

Copper .

100

Mercury .

103-6

Lead .

Palladium

Platinum

27-6

Manganese

26-2

Chromium

Magnesium

Calcium

43-8

Btzontium

68-6

Barium

. 2*89

Bromine

. . 6-74

. 8*10

127

Iodine .

. . 6-87

. 816

Su^hur

. 648

• 2*93

Selenium

. 6-62

. 3*18

128

TeUnrium

. 6-06

. 3-20

Phosphorus .

. . 6-85

. 8-15

Arsenic .

. 610

. 3*01

120*3

Antimony

. 6-09

. 319

210

Bismuth

. . 6-67

. 3*25

118

Tin

. , 6-67

. 316

Sodium .

. 6-75

. 319

Potassium

. 6-71

108

Silver »

. 616

_ fl'i

196

Gold .

. 6-38

The numbers representing Kegnault's atomic heats were obtained by multiplyisg ttte
observed specific heats of the bodies, referred to that of water as unity, by their
atomic weights on the oxygen scale. But it would be found more oonvemeoit in pnc-
tice to assume the atomic heat of lead, which correnionds nearly with ^e meu
atomic heat, as unity ; whereby the atomic heats of the first dass of metab would
approximate more or less closely to the number 1, and those of the second diss to
the number 2. On this scale, the specific heats of the first class elements would eo^
respond to the reciprocals of their atomic weights on either scale, and those of the
second class to twice their reciprocals.

At the time of Begnault's researches, the atomic weights of all the dements in the
second colunm, with the exception of sodium, potassium, and silver, were freqnentlj
expressed by the halves of the numbers we have adopted. Begnault proposed to habe
the atomic weights of these three metals also, whereby the atomic heats of all tiie
elements would be in accordance with Dulong and Petitfs law, and would be ex-
pressed by numbers approximating more or less dosely to 8*0 on the water-nmtj
scale, or to 1-0 on the lead-unity scale. It is observable that in no esse does the
experimental atomic heat thus obtained differ from the mean atomic heat in theptopor-
tion of 1*1, or 0*9, to 1*0 ; whereas the extreme atomic weights differ from one another
in the ratio of 1 to 9. Concerning this dose correspondence in the atomic heatB of the
dements, GMiam writes : '* The law (of Bulong and Petit) would probably represent
the results of observation in a perfectly rigorous manner, if the specific heat of eseh
body could be taken at a determinate point of its thermometrical scale, and if tiie
speofic heat could be further disencumbered of all the foreign influences which mod^
the observation," such as tke original state of hardness or softness of tiie body, its
crystalline or amorphous condition, the heat absorbed to produce softening, and the
heat absorbed to produce dilatation, &c Becent chemical reseajnch, however, has
rendered it impossible for chemists to halve the atomic weights of the dements in the
second column, so as to make their atomic heats coindde with that of lead ; and heaee
Cannizzaro has been led to advocate a transposition of B^^ault's proposal, so as to main-
tain the integrity of Dulong and Petit's law, b^ doublmg the atomic weights of the
metals in the first column, whereby the atomic heats of all tiie elements, with the

ATOMIC WEIGHTg. 471

|HMW^^* exception of carbon, would be expressed by numbezs approaching more or less
closely to 6.

Canniszaro has also pointed out that if his atomic weights were adopted, the atomic
heats of many oomponnd bodies, when divided by the number of their constituent
atoms, would give a number approximating more or loss closely to 6, or in other
words, the atomic heats of these bodies approximate to the sum of the atomic heata
of their constituent elements. It is observable, however, that the latter mode of ex*
pressing the fiict applies equally well, whether or not we double the atomic weights in
the first column. Thus the atomic heat of chloride of silver approximates to 6 + 6
or 12, and that of chloride of lead to 6 + 3, or 9.

It is evident that the atomic weights proposed by Cannizzaro, from considerations
of specific heat, frequently correspond with those which he and others have been led
to from considerations of atomic volume ; and their adoption is consequently liable to
the objections which we have already taken.

Cannizzaro's proposal, moreover, would involve the dissassodation of sUver from
lead, and that of the metals of the alkalis from those of the alkaline earths. The
chlorides of silver andpotassium, for instance, would be represented as protochlorides
by the formnliB AgCf and KCl respectively, whilst those of lead and barium
would be represented as dichlorid«» by the formulffi PbCP and BaCl' respec-
tively. Now the highly basic characters of the alkaline earth-metals, the strongly
alkaline reactions of their dissolved hydrates, the perfect neutrality and great per-
manency of their salts, seem to demonstrate their analognr to undisputed protequiva-
lent metals, such as potassium, rather than to undisput^ di-equivalent metals, such
as tin. Again, the large number of similar compounds to which silver and lead give
origin, the dose resemblance in chemical properties of their corresponding compounds,
their Tery general paramorphism, and not unfrequent isomorphism, seems to forbid
their representation by discordant formuLe. The two metals are soft, malleable,
fusible, volatile, and isomorphous. The two chlorides are anhydrous and insoluble,
or sparingly soluble ; the two sulphates are anhydrous, insoluble and similiform ; the
two hydrates are sparingly soluble, forming alkaline solutions ; the two sodium-double-
chlorides, potassium-double-iodide^ protosulphides, cuprososulphides, monobasic and
tribaaic smphantimonites, are similar in their chemical, and isomorphous in their
physical relations.

It seems to us that the objections to Cannizzaro's ffeneral proposition, are, in the
present state of knowledge, too great to admit of its adoption ; but still it is a question
whether some of the metals comprised in the first column might not advantageously,
receive the doubles of their ordinarily admitted atomic weights. With regard to the
metals palladium and platinum, for instance, it is not by any means improbable
that their real atomic weights may prove to be 106 and 198 respectively. With
regard to aluminium, again, it is certain that, so far as our actual knowledge goes, the
smallest indivisible proportion of aluminium that can exist in a combination is twice
the proportion expressed bv its ordinarily received atomic weight, or, in other words,
it amounts to 27*5, insteaa of to only 13*75 parts. All chemists invariably represent
the compounds of aluminium to contain 27*5 parts of aluminium, which is indeed its
smallest combining proportion or chemical atom. Consequently, by employing the num-
ber I8'75 to express the atomic weight of aluminium, all aluminous compounds have to
be represented as containing two inseparable atoms, or some multiple of two inseparable
atoms of the metal, a result which is evidently unphilosophicaL The chemical habitudes
of the metal aluminium resemble the chemical habitudes of the metal bismuth, 27*5 parts
of the former corresponding to 210 parts of the latter : and there is no greater chemical
reason for halving the 27*5 parts of aluminium in order to represent its trichloride
as a Bfgqnichloride, than there is for halving the 210 parts of bismuth in order to
represent its trichloride as a sesquichloride: Somewhat similar observations apply to
the metals, iron, manganese, and chrome, when entering into the constitution of
ferric, mangMiic, and chromic salts, respectively. Throughout all the decompositions
and reeompositions of ferric compounds, for mstance, so long as they continue to be
fexrie compounds, we find 56 parts of iron constituting one indivisible combining pro-
portion or chemical atom. We have two aUotropic forms of the metal iron, one of
iriiich we caXLfirrosum, having the atomic weight 28, the atomic heat 3, and combin-
ing with 1 atom of chlorine, to form a protochloride ; — the other, which we call
ferrieuntf havins the atomic weight 56, the atomic heat 6, and combining with 3
proportions of chlorine to form a trichloride ; and similarly with chrofnotum and chro-
ntieufH^ manganosum and manganicum. The ferrous and ferric atoms have distinct
chemical properties and form distinct series of compounds, which differ more from
one another than do the salts of ferrosum from those of nickel and copper, or than do
the salts of ferricum from those of aluminium and bismuth. So great, indeed, is the
dilEearence^ that» had we been unacquainted with the methods of converting ferrous

H H 4

472 J^TOMIC WEIGHTS.

and ferric oompounclB into one another, we ahonld never have Biupeeted them td
contain the same metal, or eren similar metals. Now, that two different allotzopic
fbrma of the same element may have different atomic weights and diflferent eqiiiTa-
lent functions, seems to be no longer questionable. Brodie's reseaches on ffripkon
haxe shown oondnsiTely that compounds nunr be prepaied which contain the |rrapiiitie
modification of carbon, and are altogether msmmilar from compounds containing the
ordinary form of carbon. In fiict^ ordinaiy carbon-compounds preaent a gieata-
analogy to corresponding compoundis of sulphur than they do to any of the known
compounds of graphon, precisely as the salts of ferrosum resemble salts of nickel move
closely than they do the salts of ferricum. The only circumstance wanting to complete
the parallel is that not only carbon and graphon compounds, but isolated carbon and
gra^on are known to chemists ; whereas, though ferrous and ferric compounds are wdl
known, chemists have not yet recognised any form of iron distinct from fierrosiim,
unless indeed we make the by no means improbable assumption that iron in the paasiTe
state constitutes ferricum. The specific heats of carbon, graphon, and diamond cor-
respond clearly with different atomic weights. Thus, if we accord to carbon the atomic
weight 12, to graphon the atomic weight 18, and to diamond the atomic weight 24, the
atomic heats of the three bodies, calculating from Begnault's results, will be 2*8980,
3*6324, and 3*5232 re^pectiyely, giving a mean of 3*3512. But it seems pcobaUe from
chemical considerations that the atomie weight of graphon is not 18, but 36 (33
Brodie), in which case its atomic heat will be 7*2048, or exactly as much above the
mean as that of phosphorus is below it.

Precisely as the double atoms of iron and aluminium in feme and alnminie salts
constitute indivisible proportions, so do the double atoms of copper and mensoxy in
cuprous and mercurous compounds constitute indivisible proportions tfaioughoat all
the decompositions and recompositions of their respective salts. So long aa the metals
remain in the state of cuprontm and merourosum, so long do 63*5 parts of the former
and 200 parts of the latter constitute their respective atomie weights or smallest
indivisible combining proportions. Each metal would have for its atomic heat tiie
number 6, and would combme with one atom of chlorine to form a protoeUoride, so that
while the atoms of ferrosum and ferricum combine with the halogens, ^fec., in difiefent
proportions, or, in other words, have different degrees of equivalency, the atoms of
merciirosum, and mercnricum though having difierent atomic weights and different
atomic heats, combine each with the same proportion of halogen, or, in other words^
have the same degree of equivalency ; and similarly with cuprosum and caprieom (see
Equivalknts). a convenient mode of representing the atoms of ferricum, mereurosum,
&c., consists in doubling one of the letters of the respective (symbols used to eaqiress
the atoms of ferrosum and mercuricum, &c, so as to indicate that the atoms of the
former elements are twice as heavy as those of the lattCT. In a similar manner the
atom of gr^hon might be represented by the symbol Ccc, to imply that it had three
times the atomic weight of carbon. In this way we might anange the following
series of atoms :

Atomic heats as 3. Atomic heats s 6.

Carbon . . C*^ 12 On^hon . . Gr or Cce 86

Aluminium . All" 27*5

Ferrosum . Fe' 28 Ferricum . Ffe*" 56

Manganosum . Hn' 27*5 Manganicum . Mm*" 55

Chromosum . Cr' 26*25 Chromicum . Ccr" 52*5

Mercuricum . He' 100 Mereurosum . Hhg'200

Cupricum . Cu 31*75 Cuprosum • Ccu 63*5

By thus recognising the quantities represented in the second column as distinct atoms,
we obtain nearly all the advantages, with scarcely any of the disadvantages, which
would accrue from Cannizzaro*s proposal, and are enabled to account satia&ctorily for
the frequent isomorphism or parallelism of the double proportions of th&e elements,
with the single proportions of other elements, as illustrated below :

KCIO* withKMmO* instead of KMnK)*

K«SO« „ K«MmO* „ K«MnK)«

K«SO« „ K«CcrO* „ K«Cr*0*

SO" „ CcrO« „ Cr»0»

SO«a« „ CcrOH)l« „ CrK)HJL'

Ag«S „ Ccu«8 „ Cu*S

A^SbS" „ Pb«CcuSbS« „ Pb«Cu*SbS»

Pb'S „ PbCcuS „ PbCu«S

In addition to vapour-density and specific heat, isomorphism also furnishes a
TBluable aid in the determination of atomic weights. As a rule, the isomorphism of a

ATOMIC WEIGHTS — ATRIPLEX. 473

compamfchrclj unknown sabstanoe, with ft snbstance of which the formnla and atomic
weight are well determined, wazrants na in according to the lees known bodj a
fofrmnla and atomic weight corresponding to those of the bettor known body. Thus,
the iaomorphiBm of the stannic and titanic anhydrides, of the chromato and moljbdato
of lead, of the solphato and selenato of sodinm, assists ns materially in our determi-
nation of the atomic weights of titaninm, molybdennm, and selenium respectively, and
of the farmnlsB of their respective compounds. But atomic weights deduced chiefly
from isomoTphous considerations, require to be received with veiY great caution,
for the following reasons. We sometimes find obvious chemical analogies to exist in
eases, where from dimorphism, or some other cause, the isomorphism is very imper-
fectly developed ; and on the contrary, we sometimes have a marked isomorphism
existing between bodies whose chemical correhitions are veiy unsatisfactoiy. Thus,
the isomorphism of potassiam and sodium salts is not by any means striking. Nitrate
of potasmnm, for instance, usually ciystaUises in right rhombic prisms, and nitrate of
so^nm in rhomboids. It seems, however, that each salt can crystallise in both
systems, and that while the ordinazv form of nitrate of sodium corresponds with the
raze form of nitrate of potassium, the ordinary form of nitrate of potassium cozre-
sponds with the rare form of nitrate of sodium. Again, the chemical analogies of
imilay lead and mercury compounds are extremely well marked, but isomorphism is
manifested in a veiy few instances onlv. Indeed the isomorphous relations of lead
andealdumare more decided than are toe isomorphous relations of lead and mercury.
Again, tellurium is heteromorphous with ite chemical analogues, selenium and sulphur,
and isomorphous with its chemical, heterologues, arsenic and antimony. One might
here refer for a moment to the well-known isomorphism of certain sulphides and
arsenidea. Thus, sulphide of nickel, Ni^, is isomorphous with the arsemde Ni^As,
and the antimonide Ki'Sb. Karcasite, Fe^S', is isomorphous with mispickel, Fe'SAs ;
and oommon pyrites, Fe'S', with cobalt-blende, Co^As, and smaltine, Co'As*.
F^m this isomorphism a general analogy in composition between arsenic and sulphur
eompoimds, might possibly be inferred)^ were it not that such an inference would
speedily be found incompatible with the resulte of chemical analysis. But if arsenic
had beien a rare and imperfectly known element, the isomorphism of marcasite and
mispickel might not improbably have led to the association of ite compounds with
thoae of sulphur instead of with those of phosphorus.

Jfareover, 2 atoms of one element are not unfrequently isomorphous with 1 atom
of another. We have already given several examples of this phenomenon when
refecting to the isomorphism of sulphates with chromates, M%0* and MH)rK)^ of
perddoratea with permanganates, MClO* and ]IOin*0\ and of salts of silver with
Bmits of cnprosum, Ag'S and Cu^S ; and we have shown how the anomaly could be
readily ex|^ained awav. Nevertheless it may be useftd to point out definitely the
kind of difficolty to which this sort of isomorphism might possibly ^ve rise. At the
present time, the ordinary salts of dnc, iron, lead, and silver, are alike thought to be
protosalts. Now we find that copper forms two chlorides, two oxides, two sulphides,
sc, in one set of which, the proportion of copper is twice as great as in the other.
Which of these sets then comprises the protosalte ? Judging from the isomorphous
relations of cnpric compounds with salto of iron and zinc, we should say that the
copric compounds were*protocompounds, and that the atomic weight of copper was
81*7. Judging, on the other hand, from the isomorphous relations of cuprous com-
poumds with salte of lead and sQver, we should say that the cuprous compounds were
the protooompounds, and that the atomic weight of copper was 63*4.

Xastly, we find that isomorphism sometimes subsists between compounds of a some-
iFliat similar, but not of a strictly analogous chemical constitution. Thus, haematite,
(F^-«0«, is isomorphous with flmenite, Fe^ri'^O'; and zircon, Z'^iO* with wer-
nerite, rAi'V'Ga'SiOf. Again, nitrate of sodium, NaNO*, calc-spar, Ca^CO*, and red-
aflver, Ag^SbS*, are isomorphous with one another; as are also nitrate of potassium,
KNO", aira^nite, Ca'GO', and boumonite, FbK>mSbS'. Perchlorate of potassium,
KCIO*, is isomorphous with sulphate of barium, Ba*SO^; and sulphate of iron,
Fe^SO^.THK), is paramorphous, if not isomorphous, with arsenate of sodium,
Na'ELAsOlTH'O. These illustrations are sufScient to show that the inferences de-
dncible from isomorphism, unless supported by chemical or by some other physical
eridenee, must not be inconsiderately adopted as certain means for the determination
of atomic weights and chemical formule. W. O.

M.TWULMMMM TU M STOn. Airamenienstein, — A product of the partial
oxidation of iron pyrites, consisting of a mixture of ferrous and ferric sulphates with
free feirie oxide and a variable quantity of cupric sulphate and imdecompoeed pyrites.
It is used in the manufiicture of ink (atrajnentum).

JLlBWOnUBLm Many plants belonging to this genus ore used for the extraction
of soda. (Rochleder.).

474 ATROPINR

a chenopodiaceoDfl plant growing in the Kngii
steppeSp leaves 12*5 per cent, of ash containing 43*3 per cent of solnble salts, tub. 7*2 per
cent, sulphate of potassium, 4'8 sulphate of sodium, and 8 carbonate of sodimn, 24*6
chloride ot sodium, and 1*9 caustic soda. (GobeL)

An oiganic acid stated by Kichter (J. pr. Chem. xL 33)
to exist in belladonna, and to be obtained by treating the aqueous extract with alcoholie
ammonia, evaporating the solution with potaah, and decomposing the resultioff
potassium-salt with sulphuric acid. It is said to resemble benzoic acid in form and
volatility ; but its properties, and indeed its separate existence, have not been well
made out.

JLTBOVIvav or DATUSZMa. C^'H:'*N0', or C^SP^NC^.—JhiB alkali, dis-
covered in 1883, ahnost at the same time by G-eiger and H e ss (Ann. Ch. Phann. viL 269),
and by Hein (t^. vL 67), exists in aU parts of the deadly nightshade {Atrcpa Bdla-
donna) ; it is also contained in the seeds of the thorn-apple {Datura stramomum\
The alkaloid has been analysed by Liebig (Ann. Oh. Pharm. vl 66), and by Planta
(ibid, Ixxxiv. 246^ ; the latter has also analyised many of its salts.

To extract it, the roots of the belladonna are treated with strong alcohol, and the
extract left some hours in contact with caustic lime, then filtered, and supenatorated
with sulphuric acid, the alcohol having been previously driven off by a gentle heat
A concentrated solution of carbonate of potassium is then added, and the liquid filtered
as soon as it begins to show turbidity. The crystals of atropine, which separate after
a while, are punfled by repeated crystallisation from alooboL Care must be taken not
to apply too strong a heat, as the atropine is easily decomposed. — ^Rabourdin extracts
the atropine by diloroform. Fresh belladonna taken at the period of flowering, is
heated to 80^ or 90^ 0. to coagulate the albumin. The clarified juice, when cold, is
mixed with caustic potash and chloroform, in the proportion of 4 gnns. potash and
30 gnns. chloroform to a litre; and the whole is agitated for a minute and then left
to settle. After half an hour, the chloroform charged with atropine separates in the
fbrm of a greenish oil, which after berng washed, is distilled till all the chloroform
passes over. The residue in the retort is extracted with -a little water acidulated with
sulphuric acid, which dissolves the atropine, leaving a green resinoua matter behind.
The acid solution is then treated with carbonate of potassium, and the precipitated
atropine cxystalUsed from alcohol.

Atropine ciystidlises in colourless silky needles united in tufts ; by slow evapora-
tion of its alcoholie solution, it is often obtained in the form of a translucent vitreous
mass. It is but slightiy soluble in water, but dissolves readily in alcohol, leas in ether.
It is strongly alkalme, and has a very bitter taste. It melts at 90^, and volatilises at
140^ C, unaergoing partial decomposition. It i^ highly poisonous, causing vertigo,
headache, and even death ; it also produces persistent dilatation of the pupiL

Chlorine acts but slowly on atropine, produdng a yellowish liquid, whi(& contains a
considerable quantity of hydrochlorate of atropine. Tincture of iodine colours it brown.
Hot nitric acid attacks it, with evolution of red fumes. Chloric acid dissolves it, hot
deposits it again unaltered, by spontaneous evaporation.

Atropine dissolves readily in acidSy but the salts are difficult to crysbillise. They
are bitter, acrid, and poisonous ; inodorous in the pure state. They are permanent in
the air at ordinary temperatures, but become coloured even at the temperature of boil-
ing water ; most of them are soluble in water and alcohol, and insoluble in pure ether.
Potaeh, ammoniOf and their carbonateSj precipitate atropine only from highly ooneea-
trated solutions of its salts ; the precipitate dissolves readily in excess of the alkali.
Tannin precipitates it only after addition of hydrochloric acid.

Acetate of atropine forms nacreous prisms grouped in stars: it is permanent and
rery soluble ; after being several times dissolved, it loses a littie of its acid. (Geiger.)

The chhro-aurate, C"H"NO*.HCLAuCl», is precipitated as a yellow powder, graduaUy
becoming ciystalline, when a strong solution of hydrochlorate of atropine is poued
into a dHute solution of trichloride of gold ; the liquid should be well shaken during
the mixing, to prevent the agglutination of the precipitate. The ehloromcrcurate is
precipitate only from very concentrated solutions. The chloroplatinate is a pulve-
rulent precipitate, which rapidly agglutinates : it is very soluble in hydrochloric acid.
The hydrochlorate crystallises in tufts (Geiger); according to Planta, itisunoys-
tallisable. The nitrate forms a syrupy deliquescent mass. Thepierate is a yellow
pulverulent precipitate. The sulphate crystallises, according to Geiger, in delicate,
oolouriess, nacreous needles, grouped in stars or tufts : it is very soluble. Planta did
not succeed in crystallising it. The tartrate is a syrupy mass, which becomes nxnst
in contact with the air.

The valerate^ prepared by dissolving atropine in an equivalent quantity of valerianie

AUGITE. 475

add dflnted with 2 pts. of ether, and cooled to 0^ 0., then addmg a farther quantity
of z«ctified efther (of 60^ Gaitieir), equal to five times the weight of the atropine nsed,
and leaying the solution to itself in a glass cylinder at 10^ C, forms colourlesfi trans-
parent ihombic crystals, which re^ct light strongly. According to Callmann (J. pr.
Chim. Ixxvi 69), they contain C»'H»NO« + JIPO.O»ff •0«. They melt at 42° C, give
off the greater part of their water at 100^, and at 120^ begin to evolve vapours of
valeriajuc add. The salt prepared as above is perfectly soluble in water.

JLVOXTB* Tyroxene. (Gm. iii 402; Handw. d. Chem. ii. 556.) — The name
of a daas of mineraLs distinguished: — 1. By a .certain form, belonging to the mono-
dime or obHque prismatic system, being a prism of 87° with the base inclined at an
angle of 74<';— and 2. By the general formula SiMK)* » M'O.SiO', or 3Af0.2@iO*,»

where H consists £ar the most part of Mg and Ca, giving the formula ^ O.SiO', less

fimjuently of Fe or Mn. Occasionally also iMg is replaced by 3H (polymeric iso-
morphiEm) ; and in the varieties called aluminous augites, 1 at. SiO' by 1 at Al^O' (or
2eiO» by 3J^0»).

Spedfic gravity 3*23 to 3'5. Biudness « 3 to 6. Lustre vitreous, inclining to
resinous : in seme varieties, pearly. Colour green, of various shades, verging on one
dde to white or greyish-white, and on the other to brown or black. Streak white to
gz^. Transparent to opaque. Fracture conchoi'dal to uneven. Brittle.

The nature of the metals, whether caldum, magnesium, or iron, which enter into the
oompodtion of the mineral, produces considerable variations, not only of colour, lustre,
transparency, and density, but also of crystallographical development^ sometimes giving
rise to difierenoes in the magnitude of the angles in the primitive forma. These dif-
ferences of character constitute the distinctions between the several species of augite,
the prindpal of which are the following.

Cotumon Augite^ (M &> Ca, Kg, Fe), ther silica being sometimes also replaced by
alumina. Blade, greenish, or brownish-black crystalline masses, with cleavage parallel
to the £ice0 of a monodinic prism of 87° and 93°. Specific gravity 3*33 to 3*36. The
best devdoped crystals are lound in basalt and other volcanic rocks. It occurs in the
lavas of Etna and Vesuvius, in the volcanic Eifel, in the Bohemian Mittelgebirge, in
the Faasathal, Iceland, and in numerous other localities. In some of these augites, the
Mg 18 almost wholly replaced by iron and caldum. Hudsonite from North America,
oontains chieflv iron and scarcely any magnesium, a condderable portion of the silica
in thia mineral is also replaced by alumina (SiO' by Al^O').

'Pyroxene, — ^This name is sometimes used as synonymous with augite, to denote
the entire fiimily ; but it is espedally applied by some mineralogists to certain varieties
of augite, having a green or dark green colour, viz. FoMaiU^ Coecolite (consisting of an
aggregation of roundish crystalline grains), Funkiiey Baihdite, &c. They are dis-
tinguished from common augite chiefly by containing a smaller amount of iron.

Diopaide (white augite, Mussite). — Essentially a sOicate of caldum and mag-
nednm, (CaMg)SiO", some varieties, however, containing small quantities of iron, man-
ganese, and even hydrogen (H* instead of Mg). Colour, white, greyish, or greenish-
vhite, and light green. Occurs in very fine crystals, especially on the Mussa Alp in
Piedmont.

MalaeolHe. — An augite rich in magnedum, also containing hydrogen, caldum
nnd iron being only subordinate. The water which it contains renders it softer than
the anhydrous augites. Salite and Pyrgom are related in chemical composition to
malaoolite on the one hand, and to pyroxene and diopside on the other.

Diallage and Broncite are, like malacolite, hydrated augites rich in magnesia,
Imt having also the silica more or less replaced by fuumina. In hgpersihenet the iron
predomin^es very strongly as protoxide. All these minerals, to which also the
augitie talcs are related (see Talc), possess a laminated structure, arising from the
peculiar ftdlity with which they cleave in a particular plane.

ABhtatotdal augites, are hydrated caldo-magnesian augites of fibrous structure :
some of them occur as paramorphosesw This is the case with TraversdUte, a hydrated
ferxoso-magnedan augite from Traversella in Piedmont To this sub-species appears
also to belong a nearly pure ferrous augite, analysed by Grann. (Compt rend,
xxiv. 794.)

The following minerals slso bdong to the augite fiimily : Mgyrin, probably a caldo-
sodium angite ; Acmits or Aehmite (p. 36), in which silica is replaced by alumina ;
Spodumene in which 3MK) are replaced by Al^O'; Jefferaonite, an augite containing
nnc; Bkodonite, a nearly pure manganese augite.

• ®iO> a 21 + 3 X 8. S10« a 28 + S X 16.

476 AUGITE — AVENTURIN.

The following are analyses of certain Tarieties of angite:

Wackcoroder. BonadoriC H. Rom.

Linie • • • •
Magnesia • • •
Protoxide of manganese
Ftotozide of iron.
Silica . . . .
Alumina

a b c d e f

2474 2476 2357 24*94 23*47 2(H)0

18-22 18-66 16-49 18*00 11*49 4*60

0-18 0-32 0*42 2-00 0*61 3*00

2-60 0-99 4*44 108 1002 18*85

5416 64-88 64*86 64*64 64*08 60*00

0-20 0-28 0*21

100*00 9973 99^99 100*66 99^67 96T6

a is diopside fiom Fossa ; b from Fammare ; e, salite from Sala; tl, malaeolite from
Qnijezfor ; e from Dalecarlia ; /from Dagero.

Giystals haying the form, stmctore, and composition of angite may be obtained bj
exposing a mixture of 1 at lime, 1 at. magnwria, and 2 at silica (1^0^ to the heat of
a porcelain fomacei and leaving it to cool yery slowly (Berthier, Ann. Ch. Phys. [2]
xxiy. 376) ; similar crystals are likewise Ibnnd among the slags of Uast-fiinaeeB.
(Noggerath, J. pr. Chem. xx. 601.)

The angites are not completely decomposed by any acid except hydioflnoric acid.
Their bel^yionr before the blowpipe yanes according to their constitution. Biopsids
yields a eolonrless nearly transparent glass ; femginoos angite, a daik-cokmred clasL
Ane;ite disaolyes readily in borax, but with difficidty in microsoosmic seit^ foinung a
skeleton of silica.

Syn. wiUi APATm.

The name giyen by Flisson to a body whidi separates from cnl of
neroli, on addition of alcohol, in white nacreons laminae ; it is piobi2>ly the camphor or
stearoptene of the oil, and appears to agree in composition with the camphor of roae*aiL
It melts at 60^ C, and on cooling solicUfies to a waxy non-crystalline mass ; in a dose
yessel it sublimes without decomposition. It is insoluble in water, dissolyes in 10 pta.
of boiling alcohol of 44^ Bm. ; soluble also in ether and in oil of turpentine. It is
not attadLed by acids. Fresh oil of neroli, which appears to be richer in this 8al>>
stance than the old oil, yields about 1 per cent of it. (Handw. d. Chem. iL 668,)

Syn. of HBSFXBiDnr.

TMm ( Aurum, ffold, and x^^^^^'i ^*^) ^ mineral occoinng in trans-
parent, yerdigris-green, needle-shaped crystals at Loktewsk on the Altai Mountains.
It appears to contain 2COH7u*.3ZnHO. When reduced, it yields a gold-eoloiiied
alloy of copper and zinc.

AVmOTBUbintXTai See Tblluxixtx, GsAFHxa
AVTOMLAJUXa. See Sfinbl.

AUTUJilTJL Lime-urauite. (See UaiXiTB.)

AUMUM XOSAZCmiK or BKUBIVUM. The old name of disnlphide of tin
prepared in the diy way. (See Tm.)

AVJUiiMt A nitrogenous substance contained in oats, similar to^ and most pro-
bably identical with, legumin.

AVJUITinun' or AVAMTintnr. A yariety of quarts rock, which, when
polished, exhibits a strong reflected light from innumerable points of its 8nz£ue^ pro-
ceeding partly from minute crystals of mica embedded in the mineral, partly from mi-
nute cracks and fissures. The most beautifiil comes from Spain, but yeiy fine npedmeDS
haye also been found at Glen Femat in Scotland. The most usual oolour is btovn
or reddish-brown, enclosing golden-coloured spangles. The mineral is used as a gem,
but is often replaced by the artificial ayenturin-glass, which eyen excels it in beauty.

A V All TUBZV O&AJMf also called gcldrfiux, — A brownish-coloured dasB
interspersed with snuJl spangles, which giye it a peculiar shining appearance. This
glass was formerly used in the arts and for ornaments, and its preparation waa long
kept secret by the manufacturers at Murano near Venice : it is now, howeyer, pn^ared
in other localities. The following are analyses of this glass : a, by Schnedeimann and
Wohler ; 6, by F61igot ; c, by Kersten.

SiO« I«0* A1«0« FeW FeK) Ca«0 Mg«0 K«0 NaH) Cu Sn Pb

a . 66-2 1-6' ^ 6-6 — 8*0 46 21 32 30 traee —

* . 67-7 — trace — 36 8-9 — 6*6 7*1 8*9 2*3 11

e . 67-8 — — 2-4 — 90 — 6*3 70 4*0 2*3 10

AVENTURIN — AZEL AIC ACID. 477

Gahn flxvt oboerveed that the spangled appearance of the glass is dne to minute
Bhinin^ opaqae, crystals, haying the form of octahedral segments. Hence, and from
the oompoflition of the glass, it was concluded that the crystals consist of metallic
coroer. Clemandot and Fremy (Compt. rend, xii 339), by melting together for
12 noon a mixture of 300 pts. of pounded glass, 40 pts. of copper filings, and 80 pts.
of iron filings, and cooHng slowly, obtained a rather dull-looking glass containing
eopper dilRised through it in octahedral ciystals. — ^Fettenkofer, on the other hand, main-
tains that the iqwngles consist of ciystals of a cuprous silicate, identical in composition,
but laiger in size than the crystals of the compound which impart the deep-red colour
to hmmafinone-glass or porporino {q, v.), and are diffused through a mass of glass
coloured green by protoxide of iron, the red crystals seen through the green glass
producing a mixod or resultant tint of brown. Aventurin-glass may in fiict be pre-
pared with certainty by adding to 100 pts. of a not too refractory ^lass, 8 to 10 pts.
x>f a mixture of eqmil parts of ferrous and cuprous oxides, and leaving the mixture to
oool fery slowly so as to &cilitate the formation of crystals. A red crystalline cuprous
compound then separatee, and the ferrous oxide remains in the glass, impartmg a
green colour. PeUenkofer has also converted hsematinone into aTentorin-glass by
addition of iron. (Handw. d. Ghem. 2** Aufl. ii 504.)

AVMM'rUMOM dTtftltHi A glazing for porcelain invented by Wdhler(Ann.
Ch. FhamL Ixx. 67). To prepare it, 31 pts. of kaolin from Halle, 43 quartz-sand, 14
gypeum, and 12 porcelain fragments, the whole finely grouid and levigated, are stirred
up with 300 pts. of water, and to the paste thus formed are successively added the
solutions of 19 pts. of acid chromate of potassium, 47 acetate of lead, 100 protosul-
I^te of iron, and sufficient ammonia to precipitate the whole of the iron. After the
potassium and ammonium-salts have been washed out by repeated decantation, the
glasing is ready for use, and is laid on the burnt wares in the ordinary manner, and
hamt br the heat of the porcelain furnace. When cold, it forms a brownish CTound,
containing crystalline lamm» which have a golden lustre, but appear green and trans-
parent under the microscope and by transmitted light ; these crystals are regarded
bj Wachter as chromic oxide or a compound of that oxide with ferric oxide.

rmr QMAXMB OV* (Fretich Berries.) See Ybllow-berbies.

A sub-species of jade, from which it differs in not beix^ of so
lig^t a green, and in having a somewhat slaty texture. The natives of New ^aland
work it into hatchets. It is found in Corsica, Switzerland, Saxony, and on the banks
of the Rirer Amazon, whence it has been called Amazonian stone. Its constituents are,
siliea 60*5, magniwia 31, alumina 10, oxide of iron 6*5, water 2*76, oxide of chromium
0-06. U.

mm ■■■»■■■- j^ silicate containing boric acid, so named from the axe-like bevelling
of its lateral edges. It is also called Tkttndtej from one of its localities, Thum in
Saxonjr- Its formula is 6MK).2M«0'.8SiO*.B20*, where MK) stands for magnesia and
protoxide of iron, and M^O* for alumina, sesquioxide of iron, and sesquioxide of man-
ganese (Gm. iiL 463). Crystalline mrstem, the tridinic or doubly oblique prismatic.
Speeific gravity 8*294. Harder than rehipar. Colour vaiying from a fine violet-brown
to leek-ereen, sometimes plum*colour ; some crystals are white and transparent, with
a glassy nistre. Before the blowpipe it exhibits the reaction of boron with acid sulphate
of potasshun. In the unignited state, it is not attacked "bj hydrochloric acid, but
yields to it after fusion. It is found in vanous localities in ^Vance, Norway, Saxony,
the Hans, and the Alps; at Botallack, near the Land's End, Cornwall; and at Tre-
weDand in that neighbourhood.

AXAlMQUni A bitter principle, perhaps an alkaloid extracted from Mdia
jUadiraekta, an East Indian tree, by f iddington (Geiger's Mag. xix. 60), who
states that it may be used as a substitute for quinine. According to O'Shaughne ssy
(Pharm. Centr. 1844, p. 366), all the parts of Azadiraehta Indica are very bitter.
The leaf is bitter and nauseating ; the bark is peculiarly bitter, and somewhat
astringent, and is used efieetively in Bombay as a substitute for cinchona bark ; the
husk of the ripe fruit yields a ver^ bitter fat oil, which possesses anthelmintic pro-
perties, and is used as an embrocation.

MMMLAIO AOEDm An acid stated bv L aurent (Ann. Ch. Fhys. [2] Ixvi. 164)
to be produced, together with suberic and other acids, in the oxidation of oleic acid
by nitric add. It closely resembles suberic acid, being distinguished merely by a
lower melting point and greater solubility in ether. Laurent assigned to it the formula
CJUM)* ; but it is probably nothing but impure suberic add. (Compare Ann. Ch.
Fh^inn. xxxv 103.)

ASOasn^HB. Azobenzide, Azoheneol, C*^'*N'. (Mitscherlich, Ann. Ch.
Fhys. xxxii. 224); Zinin, J. pr. Chcm. xxxvi. 96 ; Ivil 173 ; liaurent and Gerhardt»

478 AZOBENZENE — AZOBENZOYL.

Compt chim. 1849, 417.) — A product of the redaction of nitrobeDsene, or of theoxidft-
tion of benzidine. It is obtained, together with phenylamine, by the diy distiU&tion of
Azoxybenzene ; or simply by distilling a mixture of nitrobenzene and alcoholic potash ; or
by distilling a mixture of 1 pt. nitrobenzene, 3 pte. iron, and 1 pL acetic add (Noble).
Azobenzene passes over towards the end of the operation, as a red oil, which solidifies
on cooling,; it is freed from aniline by hydrochloric acid, andrecxystallised from alcohol
or ether. It forms large reddish-yellow scales, scarcely soluble in water, readily
in alcohol or ether. It melts at 66^0., boils* at 293^, and distils undeeomposed
(P. W. Hofmann^. Vapour-density, by experiment, « 94, referred to hydrogen;
6*50 referred to air; by calculation (2 toL), 91 referred to hydrogen, 6*32 refondto
air (P. W. Hofmann, Ann. Ch. Phaim. cxv. 364). It is soluble in nitric or Bolphniie
acid, and is reprecipitated by water. Sulphide of ammonium and sulphnrons acid ood-
vert it into benzidine. It is not decomposed when heated to 26(P C. orer soda-liiDe.
When acted on by fuming nitric acid, it yields two nitzo-substitutbn compoandi.—
Nitrcusohenzene^ C"£[*(NO')N', is formed when the reaction is not prolonged *. it sepa-
rates out in reddish-yellow ciystals, which, after the acid has been decanted, aremshed
with water, and dissolved in boiling alcohol (which generally leaves a residue of the di-
nitro compound). The solution deposits orange-yeUow ciystals of nitrazobenzene, irhich
are washed with alcohol and ether. When heated, it melts, and cools into a aystalline
mass. It is less soluble in alcohol than azobenzene. — Dinitrtisobetuene^ C**H*(^0*y]X'',
is formed when the action of the nitric acid is prolonged for a few nunntes : red
crystals are deposited, which are washed with nitric add, water, and ether, and leoys-
tallised from boiling aloohoL It forms small reddish needles, which may be obtained
larger by crystallisation from fuming nitric acid. When heated, it melts to a blood-red
liquid, which crystallises on cooling. It is less soluble than nitrazobenzene in alcohol
or ether. Sulphide of ammonium converts it into diphenine (jj. v,) F. T. C.

AXiOmaanXMB. ^■Hi»NO.(?) (Zinin, Ann. Ch. Phamu xxxiv. 190; Lanrent,
Bev. sdent. xix. 445). — ^Formed as a white eranular precipitate, when a not too eon-
centrated alcoholic solution of benzil is mixed with aqueous ammonia: after standing
in the liquid for ten hours, it is washed and recrystallised from alcohol It fbnns
long, lustrous, iridescent needles, which are soluble in alcohol, aloohoUc potash or
ammonia, and hydrochloric acid (whence it crystallises unaltered) ; insoluble in water,
potash, or ammonia. F. T. G.

AZOBBVZOXDB. G«H»N* (?} (Laurent, Ann. Ch. Phys. [2] Ixri 190).-
A white amorphous powder, formed by the prolonged action of ammonia on cnde
bitter-almond oil. It is insoluble in alcohol and ether. When heated, it melts, and
solidifies in crystalline granules ; more strongly heated, it is decomposed.

F.T.C.

AKOBBirZOIBXVa. C^*H"N». (?) (Laurent, Ann. Ch. Phys. [3] L S02.)-A
product of the action of ammonia on crude bitter-almond oiL It forms small, shiniitt,
oblique prisms : is inodorous, nearly insoluble in alcohol, slightly soluble in e&er. fi
is dissolved and decomposed b^ nitric, hydrochloric, or sulphuric acid. It solidifies
after fusion into a non-ciystallme transparent mass. F. T. C.

JLZOBSVZOZ&ZBB. C'«H»K. (Laurent, Ann. Ch. Phys. [3] i 304; xriii.
272.) — ^A product of the action of ammonia on pure bitter-almond oil The oil was
shaken up with potash and chloride of iron, distilled, and the first | which passed orer
was covered with an equal volume of ammonia. Crystals were gradnally deposited,
and in tliree weeks the oil was half solidified. The mass, when extracted with ethec^
left a residue of azobenzoilide.

2(C'H«0) + NH« - C"H"N + 2H«0.

It forms a microscopic crystalline powder, inodorous, insoluble in alcohol, veiy sli^tiy
soluble in ether. It is decomposed by prolonged fusion. Hot nitric acid dissQlres it,
apparently without decomposition ; hot sulphuric acid dissolves it, forming a jelkrv
solution, m which ammonia produces a white precipitate. - F. T. C

AZOBSVXOIX. C«'H»*N«. (Laurent, Ann. Ch. Phys. [2] Ixri. 1M.)-A
product of the action of ammonia on crude bitter-almond oiL When the yellow resinoas
mass obtained by leaving the oil for four weeks in contact with an equal volume of ammo-
nia, is treated with boiling ether, a mixture of azobenzoylandbenzoylazotide is left nndis-
solved : the former is dissolved out by boiling alcohol, and purified by recxTstallisation.
It forms a white, shining, crystalline, indorous powder, composed of uregmar six-sided
tables ; insoluble in water, not very soluble in boiling alcohol After fusion, it co(^ to a
transparent mass ; it is decomposed by a strong heat, leaving a residue of carbon.

* The boiling point of azobenzene it commonly stated, on Mitschertich*i autUbrltj, to be \9fC
doubtleu from a misprint In the original memoir.

AZOBENZOYL — AZOXYBENZENK 479

Aeooiding to Laarent (Ann. Ch. Fhys. [3] i. 800), a mixture of equal volniaes
ende bitter-aJmond oil, ammonia, and sulphide of ammonium, solidifies after a long
time; and on treating the product with boiling ether, a white crystalline powder
icmains behind, consisting of microscopic rhombic tables, which are nearly insohible in
aleohol, and slightlj soluble in boiling ether. Laarent calls thip body hydrostdphate
qf atobetuoyl, and assigns to it the formula C''H"N%**, upon which no reliance can be
placed. F. T. C.

I or. Sjn. with Htdbobbnzajodb (^.t;.)
XZDB or. See Cinnamtl.

An organic base which Anderson obtained by the action of
sulphide of ammonium on nitrocodeine. (See Codeinb.)

Gmelin's name for Azobenzedb.

■ See Obcbdt.

Syn. with (Enabthtlio Acid.

AXOSITBOnUUO AOIB. See Ltthofellio Acm.

; See Lmcus.

AOIB. See Pimabio Acm.

of Zinin. A product of the decomposition of nitro-
phenylamine by sulphide of ammonium. (See Pmbntuliiikb.)

AZOVBXnXhAJMIMB of Gottlieb, more correctly Nitrazophenylamine. A
product of the decomposition of dinitrophenylamine by sulphide of ammonium. (See
Fhkxilamibb.)

AKOXmL- A mineral occurring in the trachytic rock of the Azore Islands, in
email greenish or yellowish white pyramids. According to Hayes, it consists for the
most part of tantalate of calcium.

AJbOSV^FKIDB or BBWmB* Syn. with Htdbidb of Stjuphazo-bbnzoti.
or THiOBBHBALDiir. (Soo Bbmzoti>stdbidb, decompositions by sulphide of ammonium.)

(a priyatiTe and {l^ life.) — ^Lavoisier's name for nitrogen.

^ A name, not much used, for chloride of nitrogen.

Syn. of Njtbides.

Azoxybenzide, Azoxybenzd, C'*H'«N»0. (Zinin, J. pr.
Chem. zzzvi. 96; Ivii. 173; further, Ann. COb. Pharm. cxiy. 217; Laurent and
Gerhard t, Compt. chim. 1849, 417.) — When to a solution of 1 pt nitrobenzene in
10 Tols. absolute alcohol, 1 pt. powdered potash is added, tJie whole becomes brown, and
is heated to boiling. The mixture is shiULen up and kept boiling for some minutes : on
cooling it sometimes deposits brown czystals. The mother-liquor is decanted, and
distilled till it forms two layers. The upper is a brown oily liquid, which, after de-
cantation and washing with water, solidifies into a mass of brown needles ; tlie lower
contains aqueous potash, carbonate of potassium, and a brown potassic salt, almost in-
soluble in alcohol. The crystals are dried with filter-paper, and recrystaUised from
akohol or ether : they are easily decolorised by passing chlorine through their alcoholic
solution. 2 pts. nitrobenzene yield 1^ pt. azozybenzene.

Thus obtained, azozybenzene forms yellow, shining, four-sided needles, often an inch
long, as hard as sugar, without smell or taste, insoluble in water, hydrochloric, or dilute
»alphuric acid, potash, or ammonia, readily soluble in alcohol, still more so in ether. It
melts at 36^ C, and solidifies on cooling to a crystalline mass : it is decomposed by dir
distillation, yielding aniline and azobenzene, and leaving a residue of carbon. It is
not attacked by chlorine : bromine attacks it, forming a yellow compound, very slightly
soluble in alcohoL Strong sulphuric acid dissolves it, forming apparently a copiuated
acid. Sulphide of ammonium and sulphurous acid convert it into azobenzene.

Hi trazoiy benzene, C"H*(NO')N*0. — Azozybenzene is not attacked by dilute
nitric acid, but when gently heated with nitric acid of specific gravity 1*45, it dissolves,
with great evolution of heat, and the liquid, if carefiilly cooled, solidifies after a while, to
a thick pnlp, consisting of two isomeric nitro-compounds, nitrazozybenzene, and
isonitrazozy benzene, which may be separated by their different solubility in
akohoL If the pulp just mentioned be thrown on a filter, washed with water, treated
three or four times with a quantity of boiling alcohol not sufficient to dissolve the
whole (not more than 4 pts. alcohol to I pt. azozybenzene), and the decanted Uquors
left to cool, crystals of nitrazozybenzene are fibrat deposited ; and after a while, shining
needles make their appearance in the midst of them. If the liquid be then filtered,
and port of the alcohol distilled off, isonitrazozybenzene separates on cooling, in the
form of an oil, which quickly solidifies in a crystalline mass ; it may be pimficd by
two or three crystallisations from small quantities of very strong alcohol.

480 A20XYBENZEK E — B ABINGTONITE.

Nttrazoxyhengene is a yellowish erystalline body, sljghtiy soluble in boiliiiff alcohol
or ether. It is promptly attacked by boiling alcoholic potash, and ooIooim brown;
on adding water, a yellowish-red powder is precipitated, which may be crystalliied
from boiling oil of turpentine. This compoond appears to contain C^IPNK) fLati-
rent andGerhardt). If l^e action of alcoholic potash be prolonged, themixtme
becomes bine ; the colour is destroyed by water. An alcoholic soluticm of snlphydnto
of ammonium conrerts nitnuozybenzene, with separation of 3 at sulphur into a crys-
tallisable base^ which dissolyes readily in alcohol and in benaene, and fonna aalti with
adds.

Isonitragoxvhetuens forms crystals vexy much like those of nitiazozybeDiene, bit
easily soluble in alcohoL It dissolyes also in a large quantity of ether, and in benzene,
and often crystallises from these liquids in fine rhomboidal prisms. It melts at 49° C
but does not yolatilise without decomposition. When 1 pt of this substance is treated
with a solution of 1 pt. of potash in 8 pts. of alcohol, it melts and dissdtvea with
ebullition, giying off the odour which is eyolyed on treating nitrobenzene with akdhoiic
potadL On bouing the liquid, a resinous mass separates, which yields by diatiUatifao
an orange-coloured product, which ciystallises from alcohol, and resembles nitzo-
phenylamine. At the same time, an oily body is formed not possessing basic propertiM,
and charcoal remains behind.

Isonitraaozybenzene treated with alcoholic sulphydrate of ammonium, yields a body
haying the composition C''H*N'0 :

C'«H»(NO«)N»0 + 2m3 = C"H»N"0 + 2H)K) + S«.

This body is insoluble in water, yeiy soluble in alcohol, ether, benzene, and rod-oil,
soluble also in acids ; but does not form definite salts. It melts at 85^ C. to a yellow
liquid, which solidifies on cooling, proyided the temperature has not been raised too
high. If a strong heat be applied, a brown liquid distils oyer, soluble in aloohol,
though less so than the original substance. F. T. C.

AZOXIJIAFUIIM. Ghnelin*s name for Azoxtbenzbnb.

A brown substance produced by the spontaneous deeon^
sition of cyanogen and hydrocyanic acid. — ^An aqueous or a dilute alcoholic solution of
cyanogen or aqueous hydrocyanic acid, when left to itself for some time, especially after
addition of ammonia or potash, acquires a brown colour and gradually deposits brown
flakes, consisting of azuhnic acid. The solution contains azulmate of potasdun or
ammonium, from which the add may be predpitated by the stronger acids. The
same product is obtained by passing cyanogen gas into aqueous ftmmnnia. or alcobolie
potash. — Bespecting the compodtion of this substance, statements yaiy greatly; a^
cording to Pelouzeand Bicnardson (Ann. Ch. Pharm. zxyi 63), it is OH^NK)*,
that is to say, 4 at cyanogen + 2HK> : but it is doubtful whether any of tfaeanaljKi
haye been made upon a pure definite compound. The acid yields by dry distillation
hydrocyanic add, ammonia, and water, and leayes a residue of charcoal containing
nitrogen. (For a full account of all the modes of preparation, properties, and reaetkni
of azulmic add, see Qmelin's Handbook, zi. 376.)

See Smalt.

AXumm^TQ

See Lazulitib.

^ A mineral consisting prindpally of siUcate of iron and ol-
dum, found near Arendal in Norway, in the Shetland Isles, at CK>uyemeur in St Law-
rence County, New York, and at Athol in Massachusetts. It forms short, nearly right .
angled rhombo'idal prisms, of the triclinic system, with truncated edges and obtusely
beyelled summits. Fracture imperfectly oonchoi'dal. Colour dark greenish-black,
with yitreous lustre. Opaque in the mass, translucent in thin splinters. Hardness
5*6 to 6*0. Specific grayity 3*4 to Z'6. Brittle, producing a greenish-grey streak
Melts easily with intmnescence before the blowpipe, forming a brownish-bUd[ sfainii^
globule, attracted by the magnet. It is slowly decomposed by boiling hydrochloric
add. The mineral has been analysed by Arppe (Berz. Jahresb. zxii. 20), and
by B. D. Thomson (PhiL Mag. [3] xxyiL 123), but its formula has not yet beea
determined :

SiO« Mg«0 Ca«0 Fe«0 MnK) A1*0« ,^,5J

64-4 2-2 19-6 21*3 18 03 09 « 100-5 (Arppe)

47-5 2-2 14-7 16-8 10-2 65 12 - 991 (Thomson)

or WBB-irB8. The commercial names for tho fruits of eereral

BABL AH — BALANCE.

481

apdeies of acaeia. The principal yarieties ore East Indian bablah, finom the Acacia
Bambolah {Boxburgh), and Senegal and f^yptian bablah, from Acacia nUotica
{Bdiiif^ The pericarp of these fnnXa contains a dark brown astringent juice. The
aqoeoofl extract contains, according to GhcTrenl (Lemons de CMmie appliquSe a la
lihUtire, iL 211), gallic and tannic acids, a red colouring matter, and a nitrogenous
nbstaDce^ besides other substances not yet examined. £a8t Indian bablah yields to
boiUiig water 49 per cent, of soluble matter; Senegal bablah 57 per cent. ; neverthe-
kfl8» according to Ghiibourt, the East Indian variety is richer in tannic and gallic acid,
and therefore more valuable. Bablah is used in calico-printing in combination with
almniita and iron mordants, to produce various shades of fawn-colour. The tint pro-
dneed by the seeds is different from that obtained with the husks ; the seeds are said
to fontain a red colouring matter, and to be used in Egypt and India for dyeing
morooca (Handw. d. Chem. 2** Aufl. ii. 603.)

BASUXi-AUlC or OOVll-BAambv an inferior sort of gum arabic, from the
babul tree. Acacia AraJbica {WiUcL) growing in Bengal.

l^lTAJtTK. This name is eiven to peculiar groups of quartz-
crystaJsjOompofledof thin ciystalline plates, disposed one above the other Uko terraces.
It is found f^ Beerlston in Devonshire.

See Obthitb.

A variety of niobite found

at Bodenmais
BBvaris and at Limoges in France.

. A green modification of diopside.

Ghemistzy being concerned with the relative masses or quantities
ci the elements which compose aS. known substances, and the weight or force of
gravitation of a body being the only practicable measure of its mass or quantity
of matter, the balance, which shows the equality of two weights, and may hence
detennine the iratio of all commensurable weights, is the chemist's most important

^.78.

Theoretieally speaking, the balance consists of a lever or inflexible straight line
turning with perfect freedom on its central point A weight is applied to each extreme
point, and the force of gravity acting perpendicularly downwanls, if either of these
weights be in the least £gree greater than the other, it will prevail and cause the lever
to revolve in its own direction. The equilibrium of tlic lever or balance affords the
desired criterion of perfect equality of weight; and an arbitrary weight being assumed
flB a standard, we can arrive, theoretically speaking, at any of its multiples or sub«
moltaples by successive duplication and bisection combined with addition and sub-
traction, and a perfect measure of all weights from the greatest to the least may thus
be attained. The results of course are not absolute weights, as we say in common
0pe«ch, but ratios of weights to each other, or to the standard unit-weight-

Practically, however, the balance consists of a metal beam with two almost equal
Vox. I. II

482

BALANCE.

and similar anna, suspended near its oentape of grayitj on a pbrot, the veiglitB to bo
compared being also suspended from two pivots at nearly equal distances fimn tiie
centre piyot. In the balanoe thus constzucted, -we have far no means the sin^e and
perfect comparison of two weights supposed in theoiy ; the weight of the beam, the
friction of uie pivots, their unequal diatftnces from t-he middle one^ the nsistaiiee of
the air, and possibly other causes, introduce small extraneous fixreea, whidi render the
comparison required more or less uncertain and erroneous.

The Chbiqcal Bai.ancb, is adapted for the ordinary operatioiis of quantitative
analysis, and is usually capable of weighing any quantify leas than 100 grammes or
1600 grains. In its most perfect form (see Jig, 78) it consists of a perforated bmsa
beam, cast in a single piece, combining great strength and perfect inflexifaility with
comparatively small weight. It is suspended at the centre on a knife-edge of agate
about an inch lon^ and turns on a single polished plane of agate fixed on « pzojectiBg
brass support^ which enters a perforation of the beam, and does not impede its mo-
tion. The a^te knife-edge is firmly embedded in a wedge-8h^>ed piece of braaa, and
being once acy usted exactly at right-angles to the pUne ofOie beam, is then permanentlr
fixed. At each end of the beam is a smaller agate prism (nee Jig. 79), with the edge

J.. _ uppenuMt^ fixed in a hnuu setting, which

^ *^' ' ^' is capable of a little lateral morenunt, bat

slides upon a brass plane, in sndi a man-
ner that the two extzeme edges and tiie
centre edge are all appreciably in one
plane, as may be seen by looking along
them. The extreme edges may be moved
to or fix>m the centre edge by little ad-
justing screws, and fixed in the desired
position with tiie assistance of two damp-
ing screws.

Upon these extreme edges (i. s. km£^
edges) are balanced two agate planes, from
which, by the bent wireand a series of hooks
and light wires, the pans are suspended.
Except, howerer, when a weighing is actually being made, die agate planes and
edges are never in contact^ but the beam and pan suspensions are borne by a fivune or
movement, having in the centre two Y*s (Jig, 78) which catch projecting pins dose to
the centre edge, and lift the beam about ^ of an inch oiF the plane, iriiue steel points
(shown in dotted outline in Jig, 79.) entering hollows in the lower suifrtee of the pan-
suspensions, likewise raise tnese pkmes off the edges, and retain them in the exact
positions proper for a new experiment. The movement of the brass frame is govcned
by a rod descending through the pillar of the balance and resting on a simple eooentric,
by the turning of which it is gradually raised or lowered. In the best b^aaees too, a
second eocenmc, by means of two bent levers, raises supports beneath the pans of the
balance, and either holds these safely while weights are being placed in them, or
checks their oscillations preparatory to the release of the beam. The two eooentrics are
so a^'usted that on turning the handle, the pan supports are first n^dly dropped;
the beam is then very gently lowered on to the centre plane ; and lastly the pan-
suspensions are in the most delicate manner left free upon the extreme edges, the
beam being perfectly honiontal and undisturbed, so as not to show the sli^hteat prepon-
derance one way or another. Much of the excellence of a balance, as it is em|doyed
in chemistry, depends upon these several movements being smoothly peiformed, and
the parts being released without the least stickiness ; otherwise the beam is thrown
into oscillation, and the true approach to equilibrium cannot be readily observed.

Most of the weight of the beam and frame is usually borne by a spiral spring in the
interior of the column. An index moving over an ivory scale one inch long; divided
into twenty parts, indicates the movement of the beam. The index ahould, of coarse,
point exactly to the centre division, both before the beam is raised and when it is free
and unloaded. The balance is enclosed in a glass case, with convenient windows, not
shown in the figure ; but when a very bulky object has to be weired, the finger*
screws at the base of the column (Jig, 78) are to be loosened : the column and beam
may then be turned through about 60°, so that the scales extend without the case.
Two spirit-levels, or a drcular level, and levelling serews, are attadied by whidi the
whole instrument must be ac^justed to hoiizontality. Above the centre of the beam
is a small weighty which we may call the gravittfiob^ and which, being eerewed up
or down, regulates the stability of the balance, wnile a small tfone hdng turned to tiM
right or the left adjusts the beam to equilibrium. In the figure too vrill be seen an
arrangement of rods, by which a small rider weight may be placed upon any pari of
the beam, the balance case remaining cIosihL

BALANCE.

483

TbB Uaaee above described is by Oertling, of Bishopgate Street, London, trha like-
vias euiminicis the chemical balance in seyen diffiarent yarieties more or less elaborate.

J^. 81.

Fiff, 82.

Tlie largest of fhese^ with a 16-inch beam, able to bear two ponnds in each pan, and

Yet torn with ^^grain is a remarkably fine instrument The German balances made

by Oertlins of Berlin, Standinger of Giessen, Steinheil of Munich, and others, are

extremely delicate and well made instrmnents. Delenil of Paris ei^joys also a just

celebrity for his chemical balances. M. Stas, in his late researches npon the atomic

wsu^ts, eiiq>lo7ed a balance

hy Qambe^, which tnmed to ^*^- ^^' ^' ^*-

half a milbiprsmmewhen laden

with a Idlpgramme ; also one

bj Sacri of Bmssels, cany-

iog two or three kilogrammes

and turning with 0*3 miUi-

gramme. Fig, 83 shows the

tennisal suspension of a de-

Ueata balance by Fortin of

Parian capable cf indicating

one part in a million, while

fg, A is fitmi a German ba-

Itfuneeu

Tm AasAT Balaxcb is specially adapted for weighing small obi'ects with great
aoeoracy and'rapidly. The French assay balances consist of a yeiy light steel beam
moimted in the manner of a pair of scales with hook pan suspensions, yet their peifoiv
raanee is g^ood.

Oertling eonstmcts the assay balance in fire forms, of which the most commonly
employed has an 8-inch plain brass beam with a centre steel knife-edge and hook pan
sBupensionsi, a^jnstable by a small screw, as shown in fig, 80. It is not adapted to
bear more than two grammes in each pan, and will perhaps indicate the JU part of a

»«i 1 1 igrrimnA,

Ancyther kind has an 8-inch perforated beam, with three agate edges and planes,
and in fiict all the elaborate movements and a^jtistments of the chemical balance
above described, on a small scale. It will bear 10 or 16 grammes in each pern, and yet
indicate anrely and rapidly abont j^ of a milligramme.

Laatly, we may mention tiie 10-inch assa^ balance, with a very light perforated
beam. A fignre and a short description of this balance will be found under the article
Gold Abbkt, bat the terminal suspensions are shown here in figs. 81 and 82, and are
formed of two small screws, bearing sharp points of ruby, one workins into a little
hollow, the other into a little channel in a steel cross-piece, from whkh the pan is
snniended.

ia eontrast to the last balance it may be mentioned that Oertling constructs balances
on the principles of the chemical balance with a beam 4 feet long, able to bear
2000 oonces in each pan, and yet torn with half a gmn, or the one-millionth part of the
load. _ They are chiefly employed in the several I^^Iish and American mints for
weighing bnllion, but might be useM in some scientific investigations. See Jury
Bmrts on the Great Exhibition o! 1851 (p. 268).

it IB of little use to describe forms of the balance which are now antiaaated« Those by
Bobinson, by Bamsden, and his successor, Berge, and by Barrow, haa beams composed
of two hoOow brass cones joined at the base with many elaborate a^ustments. A
balance made by Bamsden for the Boyal Society is said to have indicated one part in
s^cn millions. In the G^ttingen Transactions, is described a balance constructed by
Osusa and Weber, the beam and scales of which were poised on watch springs, a
method contrived by Gkmss. Beams suspended by ribbons, threads, or turning on
little spheres of steel have been tried by Steinheil ; but in no imrtrument have attempt j
to invent new forms been more futile.

II 2

484 BALANCE.

Thb Adtusticeict of thb Bxajc to the due degree of sensibility and aoenracy
has to be entirely performed by repeated trial-weighings, and requires the greatest
skiU.

Firstly, if the three ed^ of suspension are not already in one plane, but admit of
adjustment, as is sometimes the case, proceed as follows: — Without weights in
the pans poise the beam, and tlien raise or lower the bob until the yibrations are ren-
dered yery slow ; now put weights into the pans equal to about half tJie greatest load
the balance is to carry, eo that the beam may be poised again ; if it now Tibntes
slowly as before, it proves the adjustment to be perfect ; but in case it either over-
sets or Tibrates too quicldy, restore it to slow motion by the adjusting weight or
gravity-bobf as we may call it, noting the number of turns of the screw and parts of a
turn which were required to produce slow motion ; now turn the screw the contrary way,
through double the noted quantity, and then produce the required slow motion by the
proper adjustment at the end of the beam. Kepeat the operation till the adjustment
IS perfect.

Secondly, to a<yust the edges of suspension to equal distances ; poise the beam wi&
weights as in the last case, and then change the pans and suspensions from one side to
the other. If equilibrium stiU holds, the adjustment is perfect ; if not, take as much
hair or wire as when put into the apparently lighter scale, will restore the balance ;
take away half of it^ and poise the beam by the proper adjustment at the left end,
which completes the process. Instead of placing any weights in the pans, all the
poising may be conveniently done by a rider-weight on the beam, and in the last
operation it is to be removed half way towards the centre of the beam. The a^just^-
ment of the edges to perfect parallelism is of course indispensable ; we only presume
that it is done by placing narrow planes or hooks on different parts of the eo^ges and
moving these untu the apparent weight is the same on whatever part the weight
bears.

A good balance in perfect ac^'ustment should bear most of the following tests :
Without weights, of course, it should remain with the index at zero, or make equal
slow excursions on either side. The pans being removed, the beam alone should be in
equilibrium, and oscillate probably much more quickly. If there be nothing in the con-
struction of the balance to hinder it, the beam should be turned round from left to right
and should act as before ; this test is a severe one, generally disclosing as it does
some defect in the work of the middle knife-edge and the planes on which it rests.
If the pans and suspensions have been separately a^ustod to equality, which is
advantageous, although not quite necessary, equilibrium should hold when the pans
and suspensions are variously changed in both positions of the beam. Lastly, the
pans being fully and equally loaded, the weights should be changed from pan to pm,
and equilmrium yet hold, proving the lengths of the arms to be fully equal.

A good balance, too, may be known by its giving the weight of an object, the same or
nearly so, when weighed several times successively. There are few balances that will
do this with certainty to the last minute fractions which they are capable of in-
dicating.

Wktghts. — ^The results required by the chemist in analyses being merdyoomparatiTe
or proportional, the choice of a unit weight \s a matter of indifference, provided
that it be not varied during the progress of an experiment. But it is most con-
venient to adopt weights connected with some national standard, so that al»oIute
weighings may if necessary be recorded. Grain weights are still sometimes used by
English chemists, but most men of science of all nations appear by a kind of tacit
agreement to have adopted the French standard weicht, the gramme, with its uniform
series of decimal multiples and submultiples ; and we therefore strongly reoonunfflid
its exclusive employment by every scientific chemist.

A complete set of Weights extends from the smallest that the balance will indicate,
up to the greatest that it will bear, and the series usually supplied with a balance is
as follows : —

'001 gramme '01 gramme '1 gramme 1*0 gramme 10*0 grammes

•001 „ -Oi „ -1 „ I'O „ 10-0 »,

'001 „ • -02 „ -2 „ 1-0 „ 20-0 „

•002 „ -06 „ '6 „ 2-0 „ 600 „

•C06 „ 6-0 „

the whole making tip just 101 grammes. These are arranged most conveniently in two
little wooden stands, which may either be introduced into the balance case or endosed
together with the^ forceps in a separate box. A glass cover also Ues over the BmaD
weights. The weights from 1 gramme upwards are best made of brass gilt ; below
1 gramme, of platinum in the form of flat squares, with a comer bent Qp for holding
in the forceps, the weight being stamped on each piece. The milligrammo weights

BALANCE. 485

tre sometun^s made of pallftdium or alnmimun ; but the latter metal is rattier too soft
for the purpose, and is apt to wear away.

An admirable improyement in the modem balanee consists in its partial employment
on the principle of the steel-yard, as flar as regards the estimation of the last minute
fraedons. A small rider, or hanging weight of uiin gold (or brass) wire, is placed upon
the Tipper edge of the beam either by the forceps, or more conveniently without opening
the case, by a brass sliding rod and a little arm (see Ji^. 78), on either side of the beam.
Now the weight which this rider exerts towards turning the beam is such a fhiction of
ita whole weight in the pan, as its distance from the centre of the beam is of the distance
of the pan-suspension from the centre. The rider commonly weighs '01 gramme, and
each ann of the beam is graduated into twenty parts ; but the fifth part of these
dirisicHis may eaaily be gueraed, so that the fractional weight may really be read off to
the ^ part of the rider weight, or *0001 gramme. This simple contrivance, compared
with ue use of minute weights in the pans, presents the following advantages.

1. Saving of much time and trouble. 2. Greater accuracy, small weights being
liable to collect dirt^ or to be rubbed or injured. 3. Minute estimation of weights to
any required degree. 4. Diminished chance of error in reading off the weight With
nnmerons small weights eirors are certain frequently to occur.

The series of grain weights 1, 2, 3, 4, 10, 20, 30, 40, &c. is not uncommonly em-
ployed, and is q[aite as convenient as tiie series 1, 1, 2, 5, 10, &c As a curious fact, it
may be mentioned, that the series of powers of 3, viz. 1, 3, 9, 27, 81, affords the greatest
snmher of combinations to a given number of weights. Thus twelve such weights give
hy addition or sttbtraetion, any integral number from 1 to 265,720, while 21 weights of
the aeries, 1, 1, 2, 5, do not reach 200,000.

WeighiB when used in a laboratory must almost always become too light by wear, or
more commonly too heavy by corrosion of the brass. Were the error always propor-
tional to the size of the weighty all error would be eliminated in any comparative
resnlt. But this is not usuaUy the case, since the mass increases as the cube, while
the snzfiice increases as the square of the diameter. Hence the small weights will be
more erroneous in proportion than the large. Weights should never be rubbed, and if
dustf, should be wiped with a silk handkerchief or a camel*s-hair brush. Small platinum
weights may be cleaned if necessary, by momentary exposure to the flame of a spirit-
lampi One set of weights should, if possible, be carefully preserved beyond the in-
floentce of Aimes, and should not be touched but by ivoiy-pointed forceps. The weights
commonly used should occasionally be tested against these, to see whether their errors
be disproportionate ; or weights may less satisfactorily be tested against each other.
An experienced weigher will never trust even the best balance maker as to the ac-
eoracy of his weights, but will always test them against each other in various ways, on
first receiving theuL Many conclusions, observes Faraday, tending to subvert most
important chemical truths, might be quoted as having arisen solely from errors in
weights and balances.

£ assaying (see Ck)U) Absat), a special unit and set of weights is adopted to suit
the weighings required ; the same might be advantageously done in any laige set of
aDa|TBe8 or experiments.

Much time will on the whole be saved in weighing, if the weights be taken me-
thodically in their proper order, 10, 6, 2, 1, 1, except^ of course, the slow motion of
the balanoe indicate that only a small weight more should be added. For if an unknown
weight exceed 10 but &11 short of 20, it is an even chance that it be above or below 15,
80 that if the weights 2, 1, 1, be used after the 10, it is as likely as not that the
we^er will lose his trouble^ and have to resort to the weight 5. In this respect the
series of weights (avoirdupois) 16, 8, 4, 2, 1, ^, }, &c is obviously the most advantageous.

When equilibrium is nearly attained, the expert weigher will notice the rapidity
with which the index of the beam traverses the arc, or the extent of the oscillation if
it be less than the whole arc, and comparing this with the load in the pans, and with
his^ prerioos experience of the same balance, wiU closely estimate the alteration of
weight required, and thus save half the time and trouble which the adjustment would
otherwise nave occupied. It will afterwards be shown that the oscillations of a good
balance may give sure determinations of the most minute fractional weights.

We cannot too strongly impress upon the reader the danger of mistakes in reading
off the weights in the pan of a balanoe. The danger is greater with small than with
large weights, and this alone would be sufficient reason for the use of a rider weight In
any case, the weights in the pan should be read, then taken out and arranged m order,
and again read ; kstly restored to the pan, and fresh trial made. Or the reading of the
weights maybe compared with the vacancies in the box of weights. When the vibra-
tions of the balance have to be read, the divisions of the sc^e should be numbered
from left to right continuously. For if the zero be in the centre, the signs + and —
XDQst be used, and mistakes are sure to occur. Under the article Gold Assay will be

II 3

486 BALANCE.

found an instance in which Tibrationa are used with great oonvenienoe in estimating
the last fractions of weights.

The casual sources of mistake are too many to mention. Not nnfreqnentfy a rider
may remain unnoticed on some part of the betun, and vitiate sereral weighings. 'When
a bulky or flexible object is being weighed, some part is Tery likely to eome in oontMit
with the balance case. We have even known a scrupulously exact gold-flssayer led
into serious mistakes by a small fly, which settled on his balance^ unobserved aft the
time.

An object heated many degrees above the temperature of the air, cannot be aoeantety
weighed ; for it is surzoun&d by ascending currents of air, wiuch cause ita apparent
weight to vaiy every moment, and it is very likely to heat and expand unequal^ the
arms of the beam above. Special modes of weighing hygroeoopie substances, ]i^di»
powders, gases, &c, must be adopted according to the nature of the ease ; the chemist
must generally depend for these on his own ingenuity, but will find many valuaUe
directions in Faraday's Chemical Manipulation, section XL, also in Gbevilie WlUianu^s
Chemical Manipulation.

If we have to oompsze the wdghts of any two objects, A and B» which are held or
accompanied by other objects, X and Y, the weights of the latter may be perfectly
eliminated if each of A and B be weighed as often in X as in Y, and the mean result
taken.

We will make the following suggestions for the care of a balance.

1. It should never be moved, if possible, from its appointed place ; for Uiia would
not only disturb its acHustment to horizontality, but the swingine and ■homing of the
pans and beam would be likely to ii\iure or slightly alter the condition of the ***J*"^
The operator too will never weigh so well as in a places and with a light to whidi
he is accustomed.

2. The balance should not be cleaned or altered often or hastily. A good cleaning
once eveiT three months, for instance^ is enough, if the balance case be kqpt well
closed. An hour or sometimes two or three, may well be spent in the operation of
cleanings All the loose parts should be carefully taken out and dusted ; the move-
ments deaued and fresh oiled ; the suspensions polished with a piece of soft leather.
Then all the parts are to be put together aoain, and brought to elaborate adjustment,
which with careful usage will be maintained for some months.

3. The chemist should be perfectly acquainted with the eapadtf, the general
character, and also the particular condition, at anv moment, of each of his baianceou

4. Before every weigning, or set of weighings, ne should try whether the unloaded
balance is in perfect equilibrium; if not, he may brush the pans or beam with a
camel's hair brush, to remove dust, or if he dust the preponderating aide only, it will
often restore equilibrium. He should not touch the little regulating vane, or alt«r any
part of the balanoe, without being satisfied that some special cause for it has arisen.
The one great essential of accuracy is perfect uniformity in everything but the thing
to be measured, and no one can have faith in a measuring instrument whidi is alwmya
changing.

5. It IS almost needless to say that a balance, especially one with steel knife-edm^
must be kept beyond reach of all acid ftimes or damp. A small vessel of quick lime
or chloride of calcium should be in the balance case, and this should be kept eonstandy
dosed.

All weighing out of reagents, where a grain more or less is not material, should
be made with common apothecaries' scales on the laboratory table.

A balance should be placed in a good light, falling if possible over the right shoulder
of the operator. But it may also with advantage be placed before a window, provided
that a purple silk shade be used. The purple light thus thrown behind the balance is
subdued, agreeable^ and complementary to the yellow of the brass. As a general rule,
the object to be weighed should always be placed in the left hand pan, which we may
hence call the o^'ecUpan, The other, orweiffkt-^^an, will thus be conveniently oppomte
the right hand. In assaying, this arrangement is reversed.

The number of balances required in a chemical laboratory may vary from one to
twenty, or more, according to me size and purposes of the laboratory. Fear the com'
mon operations of quantitative analysis, the chemical balance first described is
alone necessary. A larger balance will, however, be almost indispensable in water-
analyses, and in many physico^emical investigations, and will always be ad-
vantageous by allowing tne use of lam evaporating dishes and veaseLs, or the
weighing of a series of drying tubes, or other apparatus as a whole. But a labotatoiT
is not complete without an assay balance, which will perform all light weighings with
an accuracy and expedition impossible in a large balance.

When the employment for balances is very extensive, it will be best accommodated,
not so much by increasing the number of balances as by classifying them, ftw'g«^"g to

BALANCE.

487

taA Us proper work, and striefilj adhering to roles once laid down. VHiere there are
two balances of the same kind, it is obviously best to retain one for the more refined
pnupoaea^ and make tiie other perform all common work, and two balances thus nsed
may aerve better than half a doaen indiscriminately worked and spoiled.

Mechanical Theory of the Balance.

Fropetlj to miderstand the action of a balance, it must be considered both statically
and dynamically, that is to say, both when the beam is at rest and while it is in
motion ; for the oscillations of a good balance are almost as yalnable an indication as
its position at rest

Fiat, howerer, to show the conditions of eqnilibrinm, let O (Jiff. 85) be the central
axis of tfospenaian of a balance, and EK, the extreme axes of suspension not neces-
sarily in the same straight line with O. Suppose equal weights, eaeh « P\ to act at
£ and E*, including of course the

whole weight of tiie burthen, pans, Fiff. 85.

and other objects suspended at the
extreme axes. Then the whole
we^t 2P' may be conceived as
acting at 0\ the middle point of
thelineEB*. Assuming the axis O
to be properly placed at equal dis-
tances fromS and £*, the fine OG'
will be perpendicular to BE', and
the wmtktai the beam, say P, will
act at its centre of gnvi^, which
is, or should be^ some point G, on
this line or its prolongation.

Lastly, let some small additional
weight j» act at £. The beam can
not now remain horisontal, but may
again rest in equilibrium in some
position indined at ui angle, say 9, to the horiaontal line NIT. Drawing E N, E* IT,
G A,G' B, perpendicular to 'SN', we must have, according to the principle of the
lever, the sum of the moments of the forces on one side equal to that on the
other, or

21^.03 + P.OA -|>.0N -i<BN-BO)
Oi; sobstxtuting in tenns of 9, we have

2P'.0Q'.sine + P.OQeinB ^p.G'E.coaB -^.OG'.stna

smB jpr. G'E

tanB tm

C08B (2P+i»)0G'+P.0G

Now £>r small values, tan B varies very nearly as the angle of deviation B, which anjgle
may be regarded as the true measure of the sensibility of the balance, and j> being
quite inconsiderable oompized with 2P' and P, we may say that the seneibility is iti-
creased by inereasing the tength of the beam^ dinUmshinff the roeighte of the beam and
loadt cr dimimehing the distancee of G and Q' from the axis 0, and also that the sensi'
hUity varies very nearly in the direct or inverse ratio of these chances.

A^gain, the force tending to restore the beam to the horisontal position when dis-
tmbed is <m # (2P' . OG' ^ P.OG). Thisisthemeasureof the «toMft'^ of a balance,
a certain degree of which is required to render a balance useftiL Now with given
weights P and P', and for any given deviation B, the force of stabilily will entirely
depend upon the positions of G and G', and the following are the cases which arise.

1. The extreme points of suspension EE* may be so placed that G' falls above 0.
The stabiUty is Jtn 0(P. 0G--2P'.0G'), which foraoertain value of P' will be fio^Aifi^,
80 thnt the whole system will be suspended at the centre of ^vity, and the beam
beuoft disturbed will have no tendency to return, but will rest in neutral equilibrium,
indi&rentlyin any position.

For a greater value of P*, the force will be negative, and the eq|uilibrium unstable,
tiiat is to say, the beam when loaded beyond a certain degree will overset, and per-
manently sink down on one side without a tendency to return, even when the weights
on the ^o sides are not unequal. A balance of such construction then, could only be
used for weights of a certain smallness, and its sensibility would increase and its
stability decrease with its load.

2. If G faU above 0 and G' below, the stebility is sin B (2P' . OG-P' . OG), which
will be nothing for a certain value of P', and negative for smaller values. The balance

II 4

488

BALANCE.

then would be stcMe only when P', the load in the pans, is not less than a eeitain
magnitude.

3. If G coincide with 0 (OG » 0) and G' fall above 0, the bslanoe is alwajs un-
stable and useless.

4. If G coincide with 0 and G' &11 below 0, the stability is 2P'. OG' . ame, whidi
depends entirely upon the weight placed in the pans.

6. Now let G' coincide with O, (OG' ^ 0) the three points EOF being in a straight

line, but let G fall below 0. The stability is tin B,Pm OG, which for a giyen vahe of OG,

p OE
is constant Also tan B » -^^-r^ which depends only on p. In a bslanoe of gadi

construction, all weights may be weighed indiiferently and with emial aeemacy, ud
any required degree of sensibility may be obtained by duly regulating the length
ofOG.

6. Let G and G' coincide ; then tin $ . 0G(2F + P) is the measure of stability, ind

« GE
is proportional to the weight to be moved. Also tan 9 «■ /op^ ~~p wi ™**

inversely as the total weight moved.

In any case of stable equilibrium, it will be easy to determine the position of the

centre of gravity (say ff) of the whole system from the formula Og ■* .*L'p, p — r

by observing the deviation for several values of p, and for a given load P' in the nsns.
A different value will be found for Oa for each different value of F, unless the batiDce
be constructed in the sixth mode <le8cribed above. In a sensitive balance 0^, vill
probably not exceed ypi^ part of an inch.

We may now consider the balance in th<» character of a compound pendulum, seleeit-
ing for this purpose the fifth mode of construction above described. Thus if 0, the
centre of gravity of the beam (fff, 86), be vertically under O, and the weights in the

^.86.

pans be equal, the system will be at rest. But now suppose a small additionsl veight
p added at E : the centre of gravity is no longer at G but say at y, neaia to £ hj a
distance (Gy), such that

P ^E OE-Gy^'^-^

jp.GE
P + p

Since y is not vertically under O, the beam cannot remain at rest^ but will vifan^
about the perpendicular line OG, and the point C of the index fixed to the beam vill
describe the arc CC, subtending the angle 20.

The velocity of the beam is greatest, of course, when a is vertically under 0, and
being proportional, as proved in the theory of dynamics, to the angle 0, is also
nearly proportional to p. Hence when the deviation is small, the greatest vdoeUy wM
the beam attains may he observed as an indication of p.

As in any other pendulum, the length of time occupied in a vibration is almost the
same whether the vibration be great or small, as may easily be observed to be the
case.

Fully to understand the motions of a beam, it would be neoessaiy to determine iti
moment of inertia round the axis^ which is the sum of the moments of each paitid^
the moment of inertia being the mass of a particle multiplied by the square of it*
distance from the axis. The velocity of the beam depend on the proportion of the
force of stability or the force of disturbance, and the moment of inertia, which it has

BALANCE. 489

U> OT«roome. Hence the force of stability alone giTes a yeiy impeifect idea of the
motion of the beam, which will be slower the greater the weight in the pans, espe-
eiallj if the fbiee of stability itself be not increased, as in tke sixth case, by increasing
the weight in the pans.

Tlie mechanical problem of the balance is not so simple as may at first si^t ap-
pear, and has not, so fi&r as we are aware, been properly considered dynamically. Tne
problem of the compound pendnlnm, will be found best treated by Poisson (Traits
de M^chaniqne, t ii c. i. § 3). Euler, in the Petersboig Commentaries (z. 3), appears
to bore shown the statical condition»of a balance.

It will be apparent that» the length of the beam remaining constant, the properties
of statica] sensibiH^ and stability are reciprocal to each otber. By increasing the
length of the beam, indeed, the balance is said to be rendered both more sensible and
stable. But in reality the weight of the beam must be increased in a far greater pro-
portion than its length, so that its motions will become much slower, to say nothing
of the less conyenience of a large instrument.

The construction in which the three axes are in one straigbt line, is undoubtedly th6
«M>sfc perfect^ and is especially suitable if the yibrations are to be used, as afterwards
dncnbed, for the determination of finctional weights. But a balance in which the
centre axis is slightly aboye the line of the extreme axes, will not become so much
slower in its moyements when heayily laden, and will yet indicate at least as small a
fraction of its load when this is great, as when small. Hence such a balance will, we
think, be suitable for most purposes. It is necessary howeyer to bear in mind, that
when the three points of suspension are not in one straight line, equilibrium may
Bubeist when the beam is not horizontal, and the weights in the pans are unequal. For
when the angle EON is greater than the angle £'6N', ON and ON' are unequal, and
we may haye equilibrium for P' . ON = P* . ON', where P* and P" are unequal weights
in the pans.

The truth is, that a balance must be so adjusted in its length, strength, weight,
and lelatiye position of the centres of suspension and grayity, as to combine the exact
degrees of sensibility, stability, or quickness, and capacity for bearing weights, which
its special employment requires. In this adjustment, the chief skiU of the balance
maker consists. Diminution of weight of the beam is an unqualified adyantage, as long
as the stzenfith is sufficient. Thus the employment of aluminium in the construction of
balances, will be of great adyantage when accomplished ; but an aluminium beam,
which we haye seen, was stated not to be trustworthy in point of strength and in-
flexibility.

The impediment to the free motion of a beam, is usually stated yagnely to be the
friction at the knife edges. But although friction or adhesion may be of some im-
portance, the yariation in the length of the arms has reaUy a much greater efiect.
jlius, suppose, as is generally the case, that the knife-edges, instead of being perfectly
aharp or round, terminate in yezy narrow planes {fig, 87)i of the width x. If the

Fig.^1.

distances between the middle points of the knife edges be a, the real lengths of the two

arms of the leyer when the beam is not horizontal, 'vnll be a — x, and a + x, consequently

weights which haye the ratio of a + dr, and a—x^ may be apparently in equilibrium.

In order then that a balance with a 20-inch beam may indicate the millionth part of

. _ - _. .xi. xv 1,000,000 a — X 10 . , ..,.

Its load, we must at the most haye ^^^^^^^ « jq^^or x « —^^inch; within

the same length too, the two arms of the beam must be a^'usted to equality if the
balance is to be accurate within one millionth part of its load. Now this len^h,
being inappreciable in a common microscope, will giye some idea of the skill required
in a balance-maker. We are thus prepared too for the statement of Prof. Miller
(see reference below), that he not only detected a difierence in the expansion of the arms
of his balance by a change of temperature, owing to some difference in the quality of the
metal, but that temperature also affected the sensibility of the instrument, which
rpsembled an over-compensated pendulurfit from the differejice of expansion of the steel
knife edge and the brass in which it was fixed.
The resistance of the air has but an inconsiderable efibct upon a balance.

490 BALANCE.

Eldokation of Ebbohs. — Since eTezy balanoe however good, xeqaires some ifjMU
weight to caiue it to tarn, a difference of thin amount may exist between any two
weights which aara apparently in eqnilibrinm. Thus if a baJanoe when loaded reftiM
to turn with anything less than ^ of a grain, it is an even ektmioB^ that two wdg^ts
which do not canse the balance to move, differ by ^ of a grain or more. In the
common use of a bahmce, the turning-weight {Bcruptdum in Latin), will giTe the
limit of accuracy of the weighings. I^t this tuming-weight be Ajt/ them the balanee
will turn when Uie weights x -^ hat and x axe in the pans. It will also pfiobably turn
in the opposite direction when x-^Lx is substitftted for x + Ax, because the bolaakoe,
unless a yeiy bad one, will turn as easily one way as the other. Thus tiie mean of
X + Ax and x-« Ax, will be the true weight required, nearly freed from the emnr of in-
sensibility. This operation may be resorted to when a balance has become insensiUe by
age but IS otherwise good, and may be Tety easily performed by the use of a zida
weightb But the deli^cy of balances is generally ahead of what is required of then.
Any good balance should weigh with certainty to the ^^^^ part of its load, bat
there are as yet few chemical operations which can pretend to an aoeunuy of

Tne only other kind of enor to which the determinations of a balance are eosentiBlIy
liable, is tnat caused by the inequality of the arms : for the extreme edges can never
be a4jiuted at perfectly equal distances from the centre edge. This error is aroided
entirely and without trouble, in the ordinary operations of the diemist, by taking can^
during each analysis or series of experiments, to use, say tiie left pan inyaziably fior
the objects to be weighed, and the right pan for the weights. Hie apparent wet^iSm
of aU. the objects are thus increased or diminished in precisely the same ratu\ aad
the comparatiye results are therefore unaffected by the reed fidsitr of the v>*1*»m^-

Thus if a be the length of the arm bearing the weight-pan, and h the lensth of that
bearing the object-pan, then objects of the true weights^ x, y, #, &e. iriU appear to

weigh — X, —V, — r, but the ratios— x \—y \^g are the same as x : v : x, the ratios
a fl n o a n V w

of the true weights. That this elimination of error may be perfect^ it is obriously

necessary that no weights be placed in the object-pan, as is sometimes done^ for the

purpose of making up a giyen weight in the easiest maimer by subtraction.

Ijiere are, however, two well known methods for obtaining the true absolute weig^it

of an object^ even by a^ &]se balance. ^ The first, introduc^ by Cbinss^ proeeeds by

simply weighing the object alternately in one pan and the other. 11 the apparent

weights are the same, they are each the true weight, or the balance is appreciably

coiTOct If not, the geometric mean is the correct weight, and is found by muUiplyi]^

the true apparent weights together, and taking their square root. For if the true

weight be x, and a, d be the lengths of the balanoe arms as before^ -« x, and - x will

b a

be the apparent weights in the respective pans, and x ■■ ^/~ x . - x. If the Hf**

rent weights be very nearly equal, their common arithmetic mean -sfT' + -'] ^

quite dose enough to the truth. Thus the arithmetic mean of 1-000 and 1*001 is
1*0005, and the geometric mean 1*0004998 ... .

The second method for ascertaining absolute weights free from all error, is that
known as the method, of substitution, ascribed by Eronch writers to Borda, but pn^
bably due to the P^ Amiot. If there be one weight C in the weight-pan, and other
wei^ts X, Y, Z, &c be in succession placed in the object-pan, and the balanoe is yet

always in equilibrium, it is evident that Jr» Y ^ Z ^ — C. Thus we prove the

perfect equality of X, Y, 2^ although each of these may differ in an unknown degree
from C, owing to the inequality of b and a, the lengths of the balanoe-anns.

To compare the weights of any two objects by this method, counterpoise the greater
with the weight (7, made up of shot, tin-foil, wire, or any convenient substance.
Then substitute the second object for the first, and observe how many small wd^ts
must be added to the pan to restore equilibrium with C. The only errors which can
affect such a result will be that of insensibility, and any enor whioi may arise from
a minute change of the edges of suspension during the substitution ; but these emn
may be eliminated by taking the mean result of many such operations, a new oonnter-
poise being adjusted each time.

But when important weighings have to be made with the most rigorous accuracy, as
in the comparison of standiard weights, the method of vibrations must be resorted to.
This being a process of pure observation, as distinguished from one of adjustment.

BALLUS— BALSAM. 491

idaufB of imlimited approach to absolute exactness, just as the difference of two
•Undard yards may be ascertained to the ^j^^^s P'^ o^ <^ ^^ although it would
be imposriold to make two yards agree within ten times that quantity.

Theuoer by Fro£ W. H. Miller, on the Construction of the New Imperial Standard
FlDond (^liL Trans, exlvi (18^6) p. 753), should be studied by all engaged in exact de-
tomiaations of weights, but a more explicit account of the method of Tibrations will
ba fooad in Knpffer^s work, "Trayaux de la Commission pour fixer les Folds et
Merarea de Boasie," St Petenborg; 1841. Prof. Miller^s mode of observing the os-
dUatioiia appears to be the most eligible. His balance had a very liffht ivoiy scale,
alMvt ha]f an inch lou^ divided into spaces of about ^ inch, attaoSed to the right
end of the beam. This scale, as it moved, was viewed through a fixed compound
microaoope^ having a single horizontal wire in the focus of the eye-piece. A still more
ddiote mode of observation, is by a small mirror fixed to the beam, in which the
nfleelion of a divided scale is viewed through a fixed telescope, as in the instruments
of a magnedcal observatoxy.

The weights to be compared being very nearly in equilibrium, the balance when

releaaed oscillates slowly through a yery small arc, and the extreme pointa of each

excmaion are to be observed. Supjposing the readings thus observed to be B',B^B",B\

- B' + 2B» + 2B« + B* . ., ... . ..... - ,, 1. * V *v

Then g is the position of equiubnum of the beam : for, by the

nature of the pendulum already considered, the excursions will be as far on one side as
OD the other. In this expression, B' and B' are doubled, because they are the end of
one half vibration and tae beginning of another. Prof. Miller usually rq'ected the
lint reading because it is apt to exhibit slight irregularities, and his result was derired

from , This observation completed, a small known weight is added to

the lighter of the weights compared, and the new position of equilibrium which the
beam tends to take up, is observed by a new set of readings. Now ther deviation from
the hdrixontal position in a good balance being '^^'^[^ nearly proportional to the weight
eaoaing it^ we obviously learn from the angular diserence of the two positions of the
beam, the deviation eoiresponding to a given small weight. Hence we learn by
the simplest calculation the differenoe of weight oozresponding to the deviation in the
firrt obaervation.

The method of weighing by reversal was found more oonvenient by Fiot Miller,
than that by sabstitation, and was thus practised.

The Beoriy equal weights P and Q to be compared, were wcnghed directly against
eaeh odier, but repeatedly reversed, and the balance was so a^jtiated by a smaU con-
ataat weight placed in one of the pans or on the beam, that on interchanging P and Q,
the position of equilibrium was still near the middle of the scale. Then if (P, Q) be
the nadinff of the scale in the position of equilibrium when P is in the left hand pan,
aad Q in tioe r%ht hand pan, and (Q, P) the reading when Q is in the left hand pan,
and Pin the ri^t hand pan; then 2Q «> 2P + m ((P, Q) - (Q, P)), where m is the
veig^t equivalent to one degree of deviation on the scale.

In the detennination of the equivalents of the elements, and in many physico-
chenieal determinations, it is to be hoped that chemists will soon have to tax to the
utmost these refined methods of weighing.

On the balance generally, the reaaer may Airther consult Biot, Traiti de Physique,
i.9; Pouillet^ £L de Phys. i 66; Ann. de Chim. xxxvi. 8; Jury Beports on the
Exhibition of IS61, pp. 267—262; PhiL Trans, cxvi pt 2, p. 86. For a description
of Kspier's "Automaton-lnlance" for weighing coin, see ZWs Diotwnary of Arts,
Manufaehtrti and Mine$, L 246. W. S. J.

or maJbAIS rnmnr. A variety of spinelle^ varying in colour from
leddiah-white to pale red.

»A1fcTilWTMORTrM« A variety of iron pyrites, found in Asturia and Gallicia,
Specific gravity 4*76 to 4*90.

Beceivers andfiasks of spherical form are sometimes called balloons.

This term, originally confined to a single substance, viz. Balm of
Oilead, Mecca Balsam, or Balsam of J udea, is now extended to a variety of products,
mote or lean resembling that body, but exhibiting considerable diversity of composition
ud properties. Q!hey are viscid, aromatic liquids, which exude from growing plants,
other spontaneously, or from indsions made for the purpose.

Balsams are mixtures of resins with volatile oils, the resins being produced from the
oQa by cxidatioii, so that a balsam may be regarded as an intermediate product be-
tveen a volatile oH and a perfect resin. They may be divided into two groups, the
one including those of purely oleo-resinous character, vis. Copaiba balsam^ Mecca bal-

492 BALSAMS.

«am, and the bahams or turpentines of coniferous planta ; the other gcoop, iadud-
ing those which contain cinnamic acid, such as Peru balsayn, Iblu baUamf Liquid'
ambar, and Storax. Benzoin and Dragon's-blood are sometimes also classed among
balsams ; but the j are more properly resins ; the true balsams are liquids more or less
Tiscid, and yield volatile oils by distillation with water. The balsams of the seoond
group yield by dry distillation, cinnamate or benzoate of ethyl or methyl, and accord-
ins to ScharUng, these products, or perhaps others not previously existing in the
busams, may be formed from them by the action of aqueous alkaline Iqrs.

BdUamt of the First Group: Oleo-rerine,

Canada Balsam or Canadian Tubfentxne, Baume du Canada, is the nroduce of
Abies balsamea (Dec.), a coniferous tree growing in Canada, Virginia, and Carolina.
It collects in vesicles under the bark, and is obtained by making incisions in the
stem. It is either colourlers or slightly yellowish, rather mobile, but tenacioas and
capable of being drawn into threads, turbid when fresh, but soon becomes perfectly
transparent when left at rest It turns the plane of polarisation of a luminous ray to
the right, and has an index of refraction equal to 1^32. It dries up to a hard varnish
when exposed in thin layers to the air for about fort^-ei^ht hours, and gradually
thickens, even in closed vessels. Its power of hardemng, its transparent^, and its
peculiar refractive power, which is nearly the same as that of crown glass, renders
it very useful as a cement in the construction of optical instruments. In some coun-
tries it is used as a medicine ; when taken internally, it imparts a nutmeg odour to the
urine.

Canada balsam distilled with water, yields a volatile oil, of balsamic odour, agree-
ing in composition with oil of turpentine (Wirzen), and like that oil, turning the
plane of polarisation to the left (Biot); it also leaves a resinous cake, brittle after cool*
mg, and consisting of a mixture oi several substances. The balsam is partially soluUa
in alcohol, a granular resin remaining undissolved.

Canada bakam contains, according to Bonastre (J.Fharm. viii. 672 [1822]), 18^
per cent volatile oil, 40*0 resins easdy soluble in alcohol, 33'0 resin sparingly sohible
in alcohol, together with 8'4 caoutchouc and bitter extractive matters soluble in water.
The sparingly soluble resin is described as dry, friable, heavier than water, diflimlt to
melt, and becoming electrical by friction. According to Caillot (J. Pharm. xvL 436
[1830]), the balsam contains two neutral resins, one called abieiin (see p. 1), being
crystallisable and easily soluble in alcohol of 0*824, the other white, pulvendent, with-
out crystalline form, very little soluble in alcohol of 0*824, or in rock oil, or potash-
ley, and closely resembling the sparingly soluble resin obtained from other species of
abies ; also an acid resin, which forms a coherent paste when mixed with ^ of its
weight of magnesia, and imparts to Canada balsam the proper^ of forming a white aoap
with potash. According to Wirzen (De balsamis etprasertim de balsamo Canademst
Dissertatio, Helsin^orsee, 1849), Canada balsam contains 16 per cent of volatile
oil, 30 pts. of a resin a, soluble in boiling alcohol of 0*833, and containing CiPO*
(78'31 per cent C and 10*08 H), 33 pts. of another resin /3, insoluble in hot alcohol,
but soluble in ether, and containing C*'£P*0^ ; and, lastly, 20 pts. of a reain y, in-
soluble in alcohol and ether. Wirzen*B a resin ia probably a mixture of abietin with
an acid resin.

A balsam exactly resembling the preceding, excepting that it has a dsaket colour,
is obtained from Abies eanad^sis (Link). Canada balsam is distinguished from all
other varieties of turpentine by its peculiar odour, its perfect tzanspaiency and ducti-
lity, and the facility with which it hardens when exposed to the air. Stnsbmg
turpentine, from Abies pectinata^ which very much resembles it, is distinguished by its
optical IsBvo-rotatory power; and Venice turpentine (from Larix europ9a\ by its easy
and complete solubility in alcohol of ordinary strength, and its indififerenoe towards
calcined magnesia.

The other balsams, or turpentines, derived from coniferous plants, will be described in
the article Tubfbmtinb.

Copaiba or Copaiva Bai^aic. Balsamum Chpaiwe^ Baume de CopoMu, — This
balsam is produced by several species of Ccpaifera (order C(Bsalpiiinem\ particnlariy by
Copaifera bijugal, Willd., C. muitijuga, Hayne, C. Guianensis, C. Langsdarfii^ and d
Jacquinif Dcsf., which are indigenous in Brazil, Peru, Mexico, and the Antilles. It is
obtained by making incisions or perforations in the trees during rainy weather, and
flows so abundantly that a single incision often yields 12 pounds of the K*l«M^nt

Copaiba balsam consists of several resins dissolved in a volatile oil, the amount and
nature of the resins varying considerably in balsam from different sources. Ther« are
three principal varieties, the Brazilian, the AntUlian and the Columbian.

Brazilian copaiba is light yellow, generally transparent, of various degrees of con-

BALSAM OF COPAIBA. 493

nstence, from mobile to sympj, and of specific gravity ranging from 0*920 to 0*985.
It bits apecnliary aromatic, disagreeable odour, and a persistently bitter and irritating
taste. By exposure to the air, it becomes darker in colour, of the consistence of tur-
pentine, heaTier than water, and ultimately solid and inodorous. When heated in
eontact with the air, it takes fire and bums with a bright, but reiy smoky flame. The
baJHaTn from the Antilles differs from the Brazilian by its more viscid consistence,
darker colour, imperfect transparency, and turpentine-like odour. Columbian copaiba
is diatingoished by its turbidity, arising from suspended particles of resin, which are
deposited as a crystalline crust when the balsam is left at rest.

The chemical examinations hitherto made of copaiba balsam relate chiefly to the
Brazilian, of which two varieties are distinguished.

I. Copaiba hdUaim ehiefiy containing acid resins. — This variety, which was for-
meriy ^e only one known, is distinguished by the following characters : — It is inso-
luble in Vfoter^ but imparts to the water its taste and smeU. It dissolves in all pro-
portions in absolute alcohol, in ether^ and in oiU, both fixed and volatile ; the alcoholic
solution, however, is often rendered turbid by the separation of resinous flakes.
Alcohol of 90 per cent, dissolves a large quantity of it ; alcohol of 80 per cent, only
^ to ^ of its own weight. Mixed with an equal weight of fixed oil, it dissolves in
2 pts. of 90 per cent, alcohol, the fixed oil separating only on the addition of a con-
siaerable quantity of aloohoL It absorbs chlorine gas, becoming turbid at the same
time, from formation of hydrochloric acid. With strong sulphuric aoid, it assumes a
red colour and viscid consistence, with evolution of sulphurous anhydride, and an
odour of oil of amber. Strong nitric acid acts upon it with violence ; dilute nitric
acid more quietly, forming a hard yellow resin, jirhich dissolves partially in the acid,
and a yellow bitter substance insoluble in water *and in alcohol. Distilled with 2 or 3
per cent of its weight of strong sulphuric acid or with hypochlorite of calcium, it yields
« volatile oil of fine blue colour (Lowe, Pharm. J. Trans, xiv. 66) ; the same oil is said
to be produced by the action of add chromate of potassium. Three pts. of the balsam
mixed with 1 pt. of potash-leg containing | pt. of hydrate of potassium, yield a clear
liquid, which does not lose its transparency when mixed with alcohol or with a small
quantity of water, but becomes milky on addition of a large quantity of water. A
larger quantity of caustic potash-ley added to the clear liquid, throws to the surface a
transparent copaiba-soap, which forms a. turbid solution with a large quantity of
water, or with absolute alcohol, but dissolves, completely in ether or in hydrated
.alcohoL When an alcoholic solution of the balsam is mixed with dilute potash or sodu-
ley, a volatile oil rises to the surface, while the resulting compound of resin and alkali
remains dissolved in the hydrated alcohol. This process may be used for the prepara-
tion of the volatile oiL Five pts. of the balsam form with 2 pts. of aqueous ammonia
of spedfie gravity 0*921, a dear mixture, from which a larger quantity of ammonia
separates a soapy compound. A mixture of 9 pts. of the balsam and 2 pts. aqueous
ammonia well shaken up and left at rest at -f- 10^ C, gradually yields a crystalline
deposit, consisting of the resinous add of the balsam. The balsam likewise combines
readily with maanesia. It dissolves completely ^ of its weight of calcined magnesia,
and when mixed with ^ of its weight of that substance, thickens to a stiff paste in the
course of a few days; with | in a few hours. Similarly with quick lime. Carbonate
of magnesium likewise forms with 4 pts. of the pure balsam at mean temperatures
{lb9 C. or 60** F.), a dear visdd solution.

The balsam distilled with water yields a volatile mobile oil, C^H^ possessing in a
high degree the peculiar odour of the balsam, and forming a crystalline compound
with hydrochloric add (see Copaiba. Oil), while in the retort there remains a mass
of brittie resin, which is resolved by treatment with rock-oil, into a crystallisable por-
tion soluble in that liquid (the a resin of Berzelius), and an insoluble unctuous sub-
stance ifi resin of Berzehus). The crystaUisable resin has the formula C^'H**0', and
from its popeity of reddening litmus and uniting readily with adds, is called copaivic
acid. The crystalline depodt which separates fi^m the turbid balsam, is, according to
Fehling's investigation, a resinous add containing C^H^O". It is to these two
resins that the peculiar reactions of the balsam with bases are due. The soft resin
is, perhaps, formed by oxidation of the volatile oil in the air, and appears to have but
a very slight a£Snity for buses, inasmuch as when isolated it dissolves but slowly, and
only, witii the aid of heat, in potash and ammonia, forming a turbid solution. (See
Copaiba Bb8in&)

Besides these essential constituents, the balsam likewise contains occasionally a
small quantity of water, and, according to Durand, small quantities of extractive
matter, acetic acid (perhaps also succinic add), and a fatty substance, which re-
mains behind when the balsam is dissolved in alcohol of specific gravity 0*842 ; also
traces of chloride of calcium. The following are analyses of this variety of copaiba
baJaaim:

494 BALSAM OF COPAIBA.

Stoltse.* Giiiboart.t Gerbarl

Freth tnlMn. Cmbakm.

Volatile oil . . 38*00 45'0 41*0 31-97

Alpharienn . . 62-76 63*9 61-38 62-68

Beta-ienn . . 1-66 1-1 218 1116

Water and lose . . 769 6-44 400

100-00 100-0 100-00 lOOiW

IL Copaiba Balaam^ ooniainina only neutral reaim. Pab^oopaiba. BiiiAjL— Tfaii
Taiiety, which ie of recent intiodaction, ie dinfa'ngnJHhed from the farmer bj its niieh
mater mobOitj. In odour and taste it agreee with the preceding; but, aoeoidiiig to
Poeeelt (Ann. Ch. Fharm. Ldx. 67)i beharee in a totally difierent manner vith aol-
Tents and with bases. With alcohol, in any proportion, it forms a tarind mixton.
Potash and ammonia also form with it turbid liniments, which, •mh.ea left it rot,
deposit the balsam in its original state. It does not thicken with maffnena. The
Tohtile oil, paraeopaiba-oU, which it yields by distillation with water, is Gustisgniabed
from, the jsopaiba-oil aboYe-mentioned, by its Tiscidilrf, its spacing solubility in abeo-
lute alcohol, and especially by not forming a arstalline compouiid with hydiDcUode
add. The resinous cake, brittle in the cold, which remains after the volatile oil his
been distilled ofE, is resolred by cold alcohol into a soluble pcxtion, which iqintei
on eyaporation of the alcohol, in drops that gradually solidi^ in amorphoiiB mnmn,
and another resin, which dissolyes only in boiling alcohol and in ether, is diiBcalt to
fuse, and likewise unczystallisable. Neither of these resins exhibits any aod naedon
in the state of solution, or forms compounds with bases (see Copaiba Bmdii). Cm
hundred pts. of the Brasilian balsam Examined by Posseltk contained 82 pts. of toIi^
oil, and 18 pts. resin, the greater part of which was soluble in cold alcohol

The two Tarieties of co^ba balsam just described, the first of which, from its be-
haTiour with magnesia^ is called soUdifiable 6d!Mim, must be refpuded mmij u
types — which are, perhaps, nottheonl^ones — and may yary greatiy in the pnuortiQn
of oil and resin, and therefore in consistence. Oberdorffer (AicL Fharm. [2] xb.
172) found in three Tarieties of mobile copaiba balsam of the first Taiiety :

I. II. IIL

VolatQe oil .... 60 68 64

Eesins .... 40 42 46

The following proportions of oil and resin have been found in serecal balsams of
unknown origin :

Ulex.9 Stockhardt.! Procter.f

IV. V. VI. vll VlII IX X. Xi.

Spedflc gravis 0-928 ' ' 0-916 0-966 0-983 0-985 0^86

Volatile oil . 90 68 666 80 66 60 36 S4

Besins . • 11 42 436 20 36 60 66 64

The amount of volatile oil was estimated either by the loss of wd^t vtidi dis
balsams suffered by boiling with water (L to VI.), or by continued heating to 120^ C
(2480 R), till the weight remained constant (Vn. to XI). The balsams IV. toTL
were mobile and are not further distinguished ; Vll. and VIII. are mobile balsams of
the second variety ; IX. to XL viscid oalsams of the first variety.

According to Procter, the proportion of oil varies with the age of the trws>tfc*
youngest trees yielding the most liquid balsam. The add resins appear to be ftmed
in the plant itself while the soft resin (/9 resin) is produced bj tiie ozidation of ths
yolatile oil, and consequently increases in amount with the age of the balnmt «^
cially when it is kept in loosely dosed vessels; this is in aoooidance irith the resuts
of Oberdorffer's analyses just quoted.

Copaiba balsam is used in the preparation of lac- varnishes and tracing psper; bit
its cmef application is in medidne, as a remedy in diseases of the urinaiv peMg^
It is not known with certainty to which constituent of the balsam the peculiar physio-
logical action is due ; but it does not appear to redde espedally in the Tdatile oO; fir
in many places, the resin completdy fireed from oil is successfully used in medioi
practice^ instead of the balsam in its original state. Whether the more oLeadooes
variety, containing only neutral resins, which is of recent introduction, is capable «
exerting the same action as the more viscid and add variety, which has long Msa in
use, is not yet known.

Copaiba balsam is often adulterated, especially with fixed oils and tnipentinea Of

* Berlfner JahrK f. Pharra. xxrli. 179. f Hiann. J. Traa*. x. I7t

1 Brandfl^i Archlv, xxx. 147. J Arch. Phann. csxii. U.

I Arch. Pbarin. xxxtUI. 18. f Phtrm. J. Tram. x. 6Q&

BALSAM OP MECCA. 495

late jean East Indian wood-oU (also called Gurjun balsam, or eapivi), which closely
resembles copaiba balsam in taste and smell, has been introduced as a substitute for it.
This oil may be easily distinguished by its property of becoming gelatinous when
heated to 130^ CL (268^ F.), whereas pure copaiba busam becomes more fluid when
heated.

'nie presenoe of fixed oils in copaiba balsam may be detected by the following
methods : — 1. By placing one or two drops of the balsam on paper, and eTaporatin|r it
at a rery gentle heat. The pure balsam then leares a hard, sharply defln^ Tamish-
like ^ot» whereas if any fixed oil be present, the spot is soft ana surrounded with a
circle of &t ^Berselius). — 2. The pure balsam, boiled for some hours with water in an
open Tcasci, leases a resin which becomes brittle on cooling : fixed oils render this
xesidiie soft or greasy. — 3. The fixed oils remain behind when the balsam is dissolved
in 8 pts. of alcohol of 90 per cenl (a smaller quantity of alcohol of that stren^
wimla. leave some of the baisam undissolved, p. 493). This last method will not m-
dieate the presence of castor-oil, which is itsdf soluble in alcohol; neither will it detect
the presence of less than 10 per cent, of other fixed oils. Turpentine and oil of tur-
pentane may be recognised by their odour, especially when the balsam is dropped upon
a metal plate.

AH omer methods of testing copaiba balsam are founded on the amount of add
resins contained in it) and reli^ to the first variety (p. 498). This officinal balsam
may be regarded as genuine when, besides exhibiting tiie characters above mentioned
(Pl 493), it forms a dear or nearly dear solution with alcohol, yields by distillation
with water, not more than 45 per cent of volatile oil ; forms a dear solution with f of
its we^t of aqueous ammonia of specific gravity 0'921, and when mixed with ^ of
its weiffht of calcined magnesia, gradually K>rnis (in twenty-four to forty-eight hours)
a plastic paste. (HandworL d. Oiem. 2** Aufi. ii. 634.)

Maoc^ Baxsax or Bauc of Oilbab. OpobaUamum verum s. nUadetue, Bawne
de la Meoqwty de Judie, au du Ccdre, — ^This balsam is the produce of the BaJUamo*
dendron gUeadmte or, Amyris aUeadensis^ a shrub bdongin^ to the terebenthaceous
order, native of Arabia Felix. There appear to be three varieties of it. The finest,
whi^ is used only in the East, and has a pecoliarly fragrant odour, is said to exude from
the flowers in dear colourless drops. An. inferior sort exudes spontaneously, or from
incisions in the young branches of the plant. It is mobile, pale yellow, turbid like
ahnond symp, lias a vexy agreeable odour like rosemaiy and lemon, and a bitterish
sharp taste. When enosed to the air, it gradually hardens and loses its transparency.
The third sort, which is the most common, is obtained by boiling the wood and the
brandies with water. It is somewhat more visdd than balsam of copaiba, becomes
white and soapy when rubbed in the hand, and when dropped upon water, fi>rms a
fllm which is easily removed by a quill feather. Ordinary spirit of wine dissolves it
but partiaUy, and leaves a transparent odorous substance, of which warm alcohol of
^lecifie gravity 0*815 dissolves about two-thirds. The residue is a flocculent sub-
stance^ which may be drawn out into threads.

Trommsdorfi (Trommsd. Neues Journal, xvi. 62) ibund in a sample of this balsam,
80 per cent of volatile oil, 64 per cent, of hard resin, 4 per cent, of soft resin, and 0*4
per cent of bitter prindples. The volatile oil was mobile, colourless, fragrant, and
had a rough taste ; dissolved in- alcohol and ether, and with deep red colour in sul-
phuric add, whence it was predpitated by water as a resin. It was also resinised by
nitric add. The hard resin was honey-yellow, transparent, brittle, of specific gravity
1-383, softened at 44? 0., and mdted completely at 90^. It dissolved with difficulty
in alcohol and ether at ordinair tempneratures, easilv with aid of heat ; it was likewise
soluble in oils, both fixed and volatile. It was altered by hot nitric and sulphuric
acids, and appeared to combine with alkalis, forming compounds insoluble in tree
alkali The soft resin was brown and veiy glutinous, inodorous and tasteless ; melted,
when dry, at 112^ C. It was insoluble in alcohol and ether, but soluble in oils, both
fixed and volatile. It was not attacked bv alkalis or by strong sulphuric add ; with
nitrie add, it swelled up and became friable.

Aeeoiding to Bonastre (Ann. Ch. Ffaarm. iii 147), Mecca balsam contains in
100 pts.:

Fragrant volatile oil 10 pts.

Brown bitter extract, soluble in water and alcohol • • . 4 „
Add resin, soluble in alcohol, and not hardening . . .70 „
Stiff whitish-grey resin, sparingly soluble in alcohol . • 12 „
Acid substance and impurities •«..•. 4 „

Mecca balsam was formerly used in medicine, but has now fallen into disuse on
aooount of its scardty and deamess. In the East it is used internally as a tonic.

496 BALSAM OF PERU.

Balsams of the Second Group, containing Cinnamc Add,

LiQUiDAMBAB Balsak is the produce of Liqutdamhar sttfradfiiuiy a large tree grow-
ing in Lonisiana, Florida, and Mexico. There are two Tarieties of ity riz. :

1. Liquid Uquidambar, or Oil of liquidambar, which is ohtained by making ind-
siona in the tree, receiying the ba]^am immediately, in vesselB which pioteet it from
the action of the air, and afterwards decanting the liquid from a portion of opaque
balsam, which settles to the bottom. It is a thick transparent oil of amber-yeUov
colour, has an odour like that of liquid storaz, but more agreeable, and an aronutie
taste, which irritates the throat. It contains a rather large quantity of benzoic or
cinnamic acid, and reddens litmus paper strongly. Boiling alcohol dissoires it, with
exception of a slight residue, and the filtered liquid becomes turbid on oooUng.

2. Soft or white liquidamhar is formed from, the preceding by exposure to the air, u
when it runs down the stem of the tree and is left there to thicken. It reeembles
very thick turpentine or soft pitch, is opaque and whitish, has a less powerfiil and
more agreeable odour than the preceding, and a sweet, perfiimed, but irritating tasta
It contains a large quantity of benzoic or cinnamic acid. By oontanned exposme to
the air, it solidifies completely, and becomes nearly transparent It was formerly sold
as white Peru balsam. (Q-erh. iii 386.)

Peru Baxsam. Balsamum peruvianum; Bats, indicum. — This balsam is the
produce of certain species of Idyroxylum^ or Myrosnermum^ growing on the Balsam
coast near San Sonate, in the state of San Salvador, Central America. There are thiee
varieties of it :

1. White Peru balsam. — Obtained £rom the fruit of the tree by remoTing the
wings and the outer and middle integuments, and subjecting the inner coating to^er
with the seed, to pressure. The balsam thus obtained is pale yellow, some^^ thidc,
turbid and granular, and has an agreeable odour of melilot. When left at rest, it
deposits a solid crystalline layer. Uold alcohol or ether dissolves it but impeifedly;
the same liquids when hot dissolve the greater portion. The alcoholic solution, vfaen
left at rest, deposits crystals of my roxo carpi n (({[•f.), of which also the oystaDine
sediment above mentioned appears to consist. The ethereal extract of the babam
leaves when evaporated a mixture of resin and fixed oil. The balsam distilled vith
water, yields traces of a volatile oil and a volatile acid (Scharling). According to
Guibourt, there is another kind of white Peru balsam, which is identical with liquid-
ambar.

2. Dry Peru balsam, Balsamum peruvianum siccum, Opobalsamwn tkctm, is
said to be produced from the preceding by hardening in contact with the air. Ac-
cording to Weddell, it exudes spontaneously frY>m the atom of a myrozylum. It is
reddish-yellow, translucent, hard, smells aromatic and like vanilla, melts when heated,
and bums with a smoky fiame ; 100 pte. of it contain, according yy Tromsdoi^ ]2pts.
benzoic (more probably cinnamic) acid, 0*2 volatile oil, and 88'0 resin.

3. Black Peru balsam. Black bs^am of San Salvador or San Sonate. BaltamvM
peruvianum s. indicum nigrum. Baume de PSru noir. This, which is the ordinaiy
Peru balsam, has been known in Europe since 1580. It is said to be obtained by making
incisions in the stem of the trees, partially detaching a portion of the bark in snch a
manner as to leave it still connected with the stem at the .upper part, then thmstingirooIleB
rags between the bark and the wood, and warming the tree oy m Airing a fire ronnd it
Fresh incisions are then made higher and higher up, till the rags are s&torated, the
process occupying ten or twelve aays< The cloths impregnated with balsam are then
removed, and well boiled with water, and the balsam which sinks to the bottom is
freed from water, which it retains somewhat fimdy, by several hours boiling nodef
water. It is then further purified by straining, and sent to Europe by way of Fen,
whence its name. (Copious details of the history and preparation of this balsam, are

J;iven in Muspratfs Chemistry^ L 228 ; see also Uris DictioTuzry of Arts, Mm»-
'actures and Mines, i. 248.)

Black Peru balsam is viscid but not glutinous, of dark brown colour, opaque in Oie
mass, but in thin layers perfectly transparent, with brown-red colour. Specific gnvitj
1*15. In contact with the air, it gradually thickens, but does not solidify. It has so
agreeable odour, like vanilla, a bitter, persistently irritating taste, and an add reaction,
1000 parts of the balsam saturating about 75 of carbonate of sodium.

When heated, it takes fire and bums with a smoky fiame. When distilled with water,
it does not yield any volatile oil, but the distillate contains cinnamic acid, which exists
in the balsaun in the free state, and may bo extracted by repeated boiling with water,
or by carbonate of sodium. Peru balsam mixes in all proportions with absdutf tdcohi;
but the solution is not quite clear, and deposits a fiocculent substance when left at rest.
Weaker alcohol dissolves it less easily, and leaves a residue of resin. It is also hat
\ incompletely soluble in ether and in oils, whether fixed or volatile. It mixes without

BALSAM OF STORAX. 497

tnrbiditj with } of its weight of fixed oil, or with \ of its weight of balsam of copaiba ;
bat if a lazier qoanti^ of either of these liquids be added, two layers are formed.
Suiphurie wid converts it into a thick red mass, with evolution of sulphurous acid ;
nitric acid acts upon it only when heated, giving off nitrous fumes and hydrocyanic
acid ; after Uie evaporation of the mixture, there remains a brownish-yellow bitter
substance, soluble in water. When 2 volumes of the balsam are gently heated with

3 volumes of potaah-ley^ of specific ^vity 1*3, two layers of liquid are formed, the
xcp^et consisting of a brownish oil (oil of Peru balsam), and the lower, which is watery,
containing cinnamic acid, resins, and colouring matters in combination with potash.

4 pts. of the balsam form a soapy mixture with 1 pt. hydrate of potassium and 1 pt of
water. When subjected to dry distillation^ it begins to boil at 287° C. and yields,
with continual rise of temperature, an oil coloured by products of decomposition, while
a porous charcoal remains in the retort.

Black Peru balsam has been repeatedly analysed. The earliest examination of it
was made in 1824, by Stoltze (Berliner. Jahrb. f. Pharm. xxv. 24), who found in
100 pts. 69*0 pts. of a peculiar volatile oil, 6*4 of acid (supposed at the time to be
benzoic acid, but really consisting of cinnamic acid), 20*7 resin easily soluble in
alcohol, 2'4 resin sparingly soluble in alcohol, 0*6 extractive matter, and 0*9 moisture.

According to Fremy (Ann. Ch. Phys. [2] Ixx. 180), the balsam is composed of
variable quantities of a volatile oil (cinnamein or styracin), a crystalHsable substance
{metaeinnatnein)t isomeric therewith, cinnamic acid, and resin. On dissohang the
>^"*™ in alcohol, and adding alcoholic potash, the resin is precipitated in combination
with potash, while the cinnamein remains dissolved, and may be precipitated by
water, the cinnamic acid still remaining in solution. The oil is purified from resin by
solution in rock-oil and evaporation ; by exposing it to a low temperature, and redis-
aolving in weak alcohol, the crystalline metacinnamein, which however is not always
present, is separated (see Cimkambin). The resinous portion of the balsam appears to
be a mixture of several distinct resins, one of which agrees in composition with the
resin produced from cinnamein by the action of sulphuric acid ; another differs from
tbat just mentioned merely by containing a smaller amount of the elements of water.
Fremy therefore regards cinnamein and metacinnamein as the original constituents
of Peru balsam, the cinnamic acid as a product of oxidation, and the resins as hydrates
of cinnamein. This view explains the variation in constitution of the balsam with
age ; also the fact that cinnamic acid is still present in the balsam after it has been
boiled with water, and increases in quantity with the age of the balsam.

For Plantamour's results, which agree with those of Fremy, so far as regards the
presence of cinnamein and cinnamic acid, see Ann. Ch. Pharm. xxvii. 329 ; xxx. 347.
According to Sc barling (ibid. xcviL 168), the cinnamein obtained from different
samples of Peru balsam is not of constant composition ; but the formulae which ho
assigns to them are improbable.

The resin of Peru balsam mixed with pumice and subjected to dry distillation, yields
benzoic add, together with an oily and a wateiy distillate. On distilling the former
by itself, a lighter oilpasses over at 176° C, and afterwards a hea\7 Uquid, which
sinks to the bottom. Ilie light oil, repeatedly rectified with potash-ley, and finally
over hydrate of potassium, yields pure cinnamene, C*H'. The heavier liquid appears to
consist of benzoate of methyl and phenic acid : when distilled with potash-ley, it yields
wood-spirit. (Sc barling, loc. cit.)

BlacK Peru balsam is used in medicine as an application to wounds, and also as an
internal remedy. It is also used in perfumeiy, and in the preparation of chocolate, as
a substitute for vanilla. The white and dry balsams (p. 496) are scarce, and have
not received any practical application.

Adulterations m Peru balsam may be detected as follows : Fixed oils remain un-
dissolved on treating the balsam with strong alcohol ; volatile oils lower the boiling
point) and pass over on distilling the balsam with water; copaiba balsam and tur-
pentine may be recognised by the odour which they give out when heated ; also by
yielding volatile oils on distillation with water ; sugar and all substances soluble in
water, by the diminution of volume which the balsam so adulterated undergoes when
■hakau up with water; syrup of sugar also renders the balsam turbid.

Stobax Balsam. — This balsam is the produce of Styrax officinalis^ a shrub
gtowinff in the Levant, Palestine, Syria, and Greece. It is imported into Europe
fiom Ideate. There axe two principal varieties of it, Styrax liquidus, and Styrax
calamita.

a. Liquid storax. — This variety is sometimes transparent, of brownish-yeUow colour,
of the consistence and tenacity of Venice turpentine, and has a peculiar sweetish or
vanilla-like odour; sometimes opaque, with grey colour, the consistence of bird-Ume,
and a strong oppressive odour, slightly mixed with that of benzene or naphthalene,
liqnid storax is a mixture of styrol, cinnamic acid, styracin, and resins.

Vof- L K K

498

BALSAM OF TOLU.

b. Reed atorax, Styrax calamita, — ^This is imported in compact masseB of frigrant
odour and rich brown colour, interspersed with white tears, whence it has also been
called amygdalctid storax. According to Beinsch, it contains aboat 0*6 per eent of
Tolatile oil, 33 to 54 per cent resin, 1*1 to 2'6 benzoic acid, 8 to 14 gnm and extract,
9*6 to 24 matter extracted by potash, 20 to 27 woodj fibre, 6 water, and tnces of
ammonia. The drug sold under this name is, however, of vexr Tariable eompoaition,
often consisting of nothing but saw-dust or decayed wood, impregnated with coal-
tar, or some similar substance, and bearing no resemblance whatever to the genuine
storax.

Storax is used in medicine, as a stimulating expectorant, its operation being
analogous to that of Fern balsam or benzoin. It is also used as a detergent^ in the
form of ointment (Muspratt's Chemistry, i 225.)

ToLU Balsajl — This balsam is obtained in large quantity from incisions in the
stem of the Myrospermum tolmferum (Sprengel), Myroxylum toltaferum (Biehards),
a tree growine in various districts of Columbia, viz. in the mountains of Tnrbaoo
and Tolu, and on the Magdalena River. In the fresh state it itf yellowish, trans-
parent and liquid, like turpentine {white toltt^haUam) but changes rather quickly bv
keeping, acquiring a reddish-brown colour and stiff consistence (Sack tolti-battam}, and
being ultimately converted into a friable substance of granular crystalline strnctors
{dry toiu'balsam). It has an aromatic odour, like that of lemon and jasmine, and a
sweetish, aromatic, somewhat irritating taste. It melts at a gentle heat ; dissolves
readily and completely in alcohol ; less readily in ether and in volatile oil* ; not com-
pletely in fixed oils. Hot water extracts from it cinnamic acid (and, according to
Deville and Scharling, likewiBe benzoic acid), together with volatile oiL Heated vith
strons sulphuric acid^ it forms a red solution without giving off sulphurous acid. With
potash-ley of specific gravity 1*17, it forms a clear solution having an odour of violets,
and with drops of oil floating on the surfiice.

Tolu balsam is a mixture of volatile oil, free acid, and resin. The volaHle oc/ is ob-
tained by distilling the balsam with water, the quantity being always small, bnt
varying according to the age of the balsam. Deville obtained 0*2 per cent, Scharling
1 per cent, and, by afterwards passing steam heated to 170^ C. through the balsam,
0'2 per cent more. This oil is, according to Deville, a mixture of toiene^ CfH", pass-
ing over betweeen 160^ and 170^ C, and cinnamein^ C'fH'^0', which distils between
340° and 350° C. According to E. Kopp and Scharling, on the other hand, the oil
consists wholly of tolene, which, according to Kopp, is isomeric with oil of turpentine,
C*"H". The small quantity of volatile ou contained in Tolu balsam, and the rapidity
with which it hardens by exposure to the air, are characters by which it is readily
distinguished from bal^am of Feru.

The free acid of Tolu balsam consists, according to Deville and Scharling, of cta-
namic and benzoic acids ; according to Frem^ and E. Kopp, of cinnamic acid only.
The balsam boiled with water, yields a solution which, on cooling, deposits cxyatau
chiefly of cinnamic acid (Deville). The oil obtained by distilling the balsam with
water, and cohobating the distillate several times, deposits benzoic acid when exposed
to the air (Deville). Benzoic acid is likewise extracted, together with cinnamic add,
by treating the balsam with aqueous carbonate of sodium, or caustic potash, adding
chloride of calcium to precipitate the resins, and supersatuiating the filtrate with hy-
diochloric acid (Deville, Scharling). E. Kopp is of opinion that the benzoic aod
is a product of decomposition, and does not pre-exist in the balsam.

Resins, — ^According to E. Kopp, Tolu balsam contains two resins, an « resin, easily
soluble in alcohol, and a jB resin, C"H^*, sparingly soluble in alcohoL

The a resin, C"H"0\ according to Kopp, but more probably CH^'O*, aa suggested
by Gerhardt (Traits, iii. 408), is obtained by treating the balsam with cold akohol,
after it has been freed from volatile oil and cinnamic acid by distillation and boiling
with water. It is brown, translucent, and shining; friable in the cold; but the
powder cakes together even at + 15° C, and the resin melts at 60° C. Strong sd-
pliuric acid colours it purple-red. When dissolved in potash-ley, and exposed to iht
air, it oxidises readily, and is converted into /3 resin. By dry distillation it yields
toluene and benzoic acid.

The iS resin, CIP'O*, is brownish, dull, and without taste or smell ; melts at a
temperature above 100° C. It is sparingly soluble in alcohol and ether, dissolves with
brown colour in potash-ley, and is precipitated with violet colour by sulphuric acid.
It is more permanent than the a resin.

The mixture of the two resins, treated with nitric acid, yields a number of volatile
and gaseous products, consisting of carbonic anhvdride, nitrous anhydride, nitric oxide,
bitt-er-almona oil, hydrocyanic acid, and a small quanti^ of benzoic acid, and th«9«
remains a yellow mass, consisting of benzoic acid and a vellow resinous colouring
matter, which prevents the benzoic acid from ciystallising till it has been separated by

BALSAMS— BAMLITE. 499

■ablunatbii. The reein thus treated yidcLi aboat a third of its weight of pure benzoic
add.

According to I>eTiUe, Tola balsam contains only one kind of resin, which has the
eompoeition of the fi resin just described. To extract it, Deville dissolves the balsam
in potash largely dilated with water, saturates the liauid with carbonic acid gas,
whereby a small quantity of resin is precipitated, then adds chloride of calcium, which
precipitates the carbonic acid and the rest of the resin as calcium-salts, leaying benzoic
and dnnamic acids in solution. The rose-coloured mass, left after filtration, is then
treated with hydrochloric acid, which dissolves out the lime and leaves the resin, and
the latter is porified by solution in a small quantity of alcohol and precipitation by
water. It then forms a rose-coloured powder, having a faint odour of vaniUa, soluble
in alcohol and in potash, very hygrometric, and varying considerably in colour from
the effect of atmospheric influences, and perhaps also of light. Treated with fuming
nitric acid, it takes fire and bums as in oxygen. By dir £stillation, it yields a small
quantity dT water, benzoic acid, toluol, benzoate of ethyl, and a mixture of carbonio
oxide and carbonic anhydride. (Deville.)

Scharling finds that, when the resins of Tolu balsam are mixed with half their
weight of powdered pumice, and covered in the retort with a layer of pumice, the
process of dzy distillation goes on quietly and without tumefaction. 16 pts. of the
resin heated in this manner, ultimately to redness, yield 2 pts. of a waterv, and 5 pts.
of an oily liquid, which is heavier than water, and is resolved by fractional distillation
into toluol, phenic acid, and a portion boiling above 198^ C. The latter was not ob-
tained of constant boiling point, and yielded by analysis numbers intermediate
between the composition of benzoate of ethyl, C'H*(CH^^O^ and benzoate of methyl,
CH^CH')0'. when distilled with potash, however, it yielded only methylic alcohol,
without any common alcohol; hence it appears that the products oi distillation of the
resins are toluene, phenic acid, and benzoate of methyl.

The mode of formation of Tolu balsam is not^ known with certainty. If we regard
dnnamein as the primary constituent, the resins a and /3 may be formed from it by
absorption of oxygen and water :

C»«H«0« - C'*H»«0« + O + H«0
• resin. Cinnamein.

C»"H»0» - C"HW0« + 0 + 2H«0
fi rosin.

or the a resin may be converted by oxidation into the fi resin and cinnamic add :

2C'"H»»0* + 0 - C'*H»0» + 2C»H«0«
• retln. B resin. Cinnamic

acid.

Lastly, the fi resin may split up into benzoic acid, water, and a hydrocarbon :

whidi hydrocarbon is supposed by E. Kopp to give rise to the formation of tolene.
Scharling, on the other hand, supposes that all the constituents of the balsam are
formed from tolene, inasmuch as this body, when exposed to the air, quickly becomes
lesinous and acquires an add reaction. It must be observed, however, that the resins
thus formed are very different in composition and properties fh>m those of Tolu balsam,
and the nature of the add has not been determined.

Tolu balsam is used medicinally to facilitate expectoration in coughs and chronic
catarrhs ; also in perfrimery. It is said to be often adulterated with liquid storax,
liquidambar, and Canada balsam. Pure Tolu balsam may be known by its perfect
transparency when fresh ; by its odour ; by its freedom from water ; by its perfect solu-
bility in potash-ley of 1'17, and in alcohol ; and by its reaction with sulphuric acid.

^^*-«^**»i AXTZFZCZAJb. Pharmaceutical preparations, chiefly for external
nae, and somewhat resembling the natural balsams in their physiod character,
e. g. SaUamum opodddoe, an aloohoUc soap-solution containing ammonia; Bahamum
Arctn, a salve containing elemi-resin ; Balsamwn sulphuriSf a solution of sulphur in
linseed oil, &C.

SAIURMOXZTB* A variety of ehxysotil, or flbrous serpentine, found at Balti-
more in North America.

A silicate of aluminium, found in microscopic linear or flbrous
crystals, at Bamle in Norway. Specific gravity 2*984; hardness about equal to that
of disthene; colour varyin(|[ from white to pale greenish; lustre vitreous to silky;
translucent, or in single individuals nearlv transparent and colourless. According to
Erdmann' s analysu (J. pr. Ghem. xxxi. 165) it contains 66*9 silica, 40*73 almninai

KK 2

500 BARALITE— BARIUM.

1'04 ferric oxide, 1*04 lime, and traces of fluorine, numbers which correspond neariy
to the formula Si»Al>"»0"» = 4Al*0«.9SiO* ; but it requires further examination.
Kobell regards it as a mixture of disthene and quartz.

BAHATiITg or BAVAZiZTB. A mineral from Baralon, C6te du Nord, con-
taining silica, alumina, ferric oxide, lime, magnesia, and water. It is probably a
mixture, the separate constituents of which are not distinguishable by the eye.

BA&BATZIMCAO. A name applied to several Brazilian barks containing taanin,
aud used both as astringent medicines and in the tanning of leather.

BAXBZO&ZOira. A blue Tariety of anhydrite cut and polished for Tarions
ornamental purposes.

BAJtBOZV. Glairin. — A nitrogenous substance contained in sulphiuons thennal
springs, especially in France. It fbrms a deposit on the sides of the basins and
conduits of the springs, which are sometimes filled with water and sometimes empty,
never occurring in parts which are constantly full. The name baregin is derived froia
its occurrence at Bareges; it is also called Ptombierin, from Plombiires, another
locality in which it is found in considerable quantity. Baregin is in the moist state
a transparent, gelatinous, nearly colourless substance, destitute of taste and odoor.
It dissolves very sparingly in the cold, more readily at higher temperatures, in vater,
alcohol, aqueous acids, and alkalis, and in oil of turpentine; msoluble in ether.
When dried, it forms a homy mass, and on heating this mass, it emits an odoor like
that of burnt horn, together with ammoniacal vapours. According to Bonis (Compt.
rend. xli. 16) it contains from 44 to 487 per cent, of carbon, 67 to 77 hydrogen,
5*6 to 8*1 nitrogen, and 30*2 to 407 per cent, of ash, chiefly consisting of silica. It
does not contain sulphur. According to Danberg, it consists for the moat part of a
mass of conferva: and oscillatorise.

Nearly allied to, if not identical with baregin, is a substance which is sometimes
formed m the quick method of preparing vinegar (see Acetic Acid, p. 7\ and attaches
itself in gelatinous shreds to the inside of the perforated casks. This substance when
dried forms a parchment-like layer, containing 42 per cent, carbon and 6 hydrogen,
besides nitrogen and oxygen, and leaving an aULaline ash. (G-erh. iv. 536; fiandw.
d. Chem. 2*« Aufl. iL 643.)

BA&ZXi&A or BARZZi&OK. The term given in commerce to the impure soda
imported from Spain and the Levant. It is made by burning to ashes different plants
that grow on the sea shore, chiefly of the genus SaUola, and is imported in hard
porous masses of a speckled brown colour. Kelp, a still more impure alkali, made in
this country by burning various sea-weeds, is sometimes called British barilla. These
substances were formerly the source of all the soda of commerce ; but their nss is
now almost entirely superseded by the manufacture of soda from common salt,

BABXVM. Symbol Ba ; Atomic weight 68*5. — (The name is derived from ^%
heavy, in allusion to the great density of its compounds.) This metal occurs abon-
dantly as a sulphate and carbonate ; also in the mineral baryiocaicUe^ a carbonate d
barium and calcium, in certain ores of manganese, in Harmotome and in Brevsterite;
traces of it has also been found in mineral waters. It is never found native. Tfa«
oxide, baryta^ was first recognised as a peculiar earth, distinct from lime^ by Scheele,
in 1774 ; and the metal itself was first obtained by Davy, in 1808.

Preparation. — 1. Hydrate of barium, or the carbonate, chloride, or nitrate, is mad«
into a doughy mass with water, formed into a cup, and placed upon a platinnm dish,
which is connected with the positive pole of a voltaic battery of 500 pairs of plates,
the cup being filled with mercury, into which the negative wire dips. The amalgam
of barium thus obtained is heated in a tube of glass without lead, filled with the
vapour of rock-oil, till all the mercury is sublimed (Sir H. Davy). If the hydrate of
barium is mixed with oxide of mercury, the amalgam is obtained in lai^r qnantity
(Sir H. Davy.) Hare (J. pr. Chem. xix. 249) prepared the amalgam m a similar
manner from moistened chloride of barium surrounded by a freezing mixture, nsing
two batteries, each of 100 pairs, and containing more than 100 square feet of a«.
The mercury was expelled by heating the amalgam in an iron crucible prorided vith
an iron cover, and exhausted of air. — 2. Barium may be obtained in an impore state,
according to Davy, by passing vapour of potassium over red-hot baryta or chbrid« of
barium. — 3. Pure baryta or the nitrate is placed in a hole made in a piece of charcoal
or slate, and exposed to a burning jet of detonating gas, produced from three measures
of hydrogen and one measure of oxygen gas. Effervescence takes place, and irhite,
shining little globules of metallic barium are formed. The baryta must be anhydrous
and the detonating gas must be passed through oil and not through water; othervise a
translucent vitreous or homy mass will be obtained. (Clarke, Ann. Phil. xvii. 419.)
— 4. Buns en subjects chloride of barium, mixed up to a paste vnth. water and a little

BARIUM: CHLORIDE. 501

hydrochloric add, at a temperature of 100^ C, to the action of the electric cnrront,
nsLDg an amalgamated platmum wire as the negative pole. In this manner, the metal
is obtained as a solid, suver-vhite highly crystalline amalgam, which, when placed in a
little boat made of thoroughly ignited charcoal, and heated in a stream of hydrogen,
yields barium in the form of a tumefied mass, tarnished on the surface, but often
exhibiting a silyer-white lustre in the cavities (Pogg. Ann. xcL 619). Matthiessen
has obtained barium by a method similar to that adopted for strontium (q. v.) ; but
only in the form of a metallic powder.

Properties. — ^Barium, according to Davy, is a silver^white metal with less lustre than
cast-iron ; according to Clarke, it has the colour and lustre of iron ; according to
Matthiessen, it is a yellow powder. It sinks rapidly in strong sulphuric acid, even
when surrounded by bubbles of gas. Its specific gravity, accoi^ing to Clarke, is 4*0
or somewhat greater. It is ductile, and may be beaten flat, though with difficulty.
It melts below redness, and does not volatilise at a red heat. It oxidises rapidly in
the air, becoming heated at the same time, and decomposes water rapidly at ordinary
temperatures. "When heated in the air, it bums with a dark red light (Davy) ; before
the oxy-hydrogen blowpipe it bums with a greenish flame (Clarke). Sulphuric
add rapidly converts it into sulphate, with evolution of hydrogen.

^dUfXaUi, BKOBOBB Or. BaBr. Crystallised: BaBr.H'O. — Prepared by
saturating baiyta-water, or sulphide, or carbonate of barium with hydrobromic acid,
or by decomposing the sulphide with free bromine, sulphur being at the same time
predpitated. It is very soluble in water and crystallises with difficulty. Isomor-
phons with the chloride. It is soluble in strong alcohol, and may thus be separated
from the chloride, which is nearly insoluble in that liquid.

masnrX, OB&OBZBB or. Bad. ChystaUised.'B&Ci.WO.— The hydratM
salt was formerly called Terra ponderosa salita. This salt is prepared either from the
carbonatA or from the sulphate of barium, both ot which are natural minerals. Tlic
carbonate (witherite) is simply dissolved in hydrochloric add, and the resulting chlo-
ride purified by reciystiUation. From the native sulphate (heavy spar), the chloride
may be prepai«d in two ways : 1. By igniting the sulphate in a crucible with pounded
cool, whereby it is converted into sulphide, %a^, extracting the sulphide by boiling
water, and decomposing the filtered solution with hydrochloric add :

Ba«S + 2Ha « 2BaCl + H«S ;

The acid is added in suffident quantity to produce a strong acid reaction, and the liquid
is boiled for some time to drive ofT all the sulphuretted hydn^n, then filtered, eva-
porated, and cooled till it crystallises. — 2. By heating a mixture of 2 pts. heavy spar,
and t pt. fbsed chloride of calcium to redness for about an hour. Sulphate of calcium and
chloride of barium are then formed (SO«Ba« + 2CaCl » SO^Ca^ + 2BaCl), and the
hitter ma^ be extracted by pulverising the fused mass, boiling with water, and filter-
dug as quickly as possible ; otherwise, a portion of the chloride of barium will be re-
converted into sulphate, because the sulphate of calcium in the residue gradually
dissolves in the water, and mixing with the dissolved chloride of barium, produces a
reaction exactly the reverse of that which took place in the fused mass. The decom-
position of the sulphate may be facilitated by adding to the mixture in the crucible a
quantity of iron filings and charcoal. Sulphide of iron is then formed, together with
an insoluble oxysulpMde of caldum, from which the chloride of barium may be sepa-
rated by water as above.

Commercial chloride of barium often contains small quantities of the chlorides of
strontium and calcium ; also chloride of aluminium, sesquichloride of iron, ana some-
times traces of copper and lead. The chlorides of strontium and calcium may be
removed by washing the crystals with alcohol ; the latter also by digesting the aqueoup
solution with carbonate of barium, whereby the chloride of calcium is slowly decom-
posed and converted into carbonate ; the same decomposition may be more quickly
effected by adding baryta-water, and then passing carbonic acid gas into the liquid.
Digestion with carbonate of barium also precipitates the aluminium and iron in the
form of sesquioxides. Lead and copper may be predpitated by adding to the solution
a small quantity of sulphide of barium.

Chloride of barium crystallises from its aqueous solution in transparent, colourless,
four-nded tables^ belonging to the trimetric or right prismatic system. The form of
the crvstalfl resembles that of heavy spar. The angles are oo P : oo P » 93° 20' ;
oP : iP 00 « 142*^ 36' ; oP : * I* oo « 140° 57'. ITie crystals decrepitate in the fire.
Their spedficmvity is 2*66 (Filhol) ; cubical expansion from 0^ to 100° C. = 0*00987
(Joule and PI ay fair). They have an unpleasant, bitter, and sharply saline taste,
exdte nausea, and are highly poisonous.

100 pts. of water at (P C. dissolve 32*62 pts. of anhydrous chloride of barium, nnd

XK 3

602 BARIUH: DETECTION.

0*271 1 pt8. for eveiy degree above 0^ C. ; 100 pts. of water at 15*6 dusolTe 43'5, and at
105*5^, 78 pts. of the cryetallised chloride (Gaj-Lussac). One pt of oystaUiied
chloride of barium dissolyes at 18*1^ in 2*257 pta. of water, forming a solution of
specific gravity' 1*28251 (Karsten). Specific gravity of a satorated flolntion at
8*^ => 1*270 (Anthon). Water acidulated with hydrochloric acid diaaolves leaa titan
pure water, and concentrated aqueoua hydrochloric acid hardly any ; so that a aata-
rated solution in water is precipitated by it Hot absolute alcohol diasolTes only
■^ pt. of the crystals, but more if it contains water. According to Fresenins
(^nn. Gh. Pharm. lix. 117), one pt of the salt dissolves in 8108 pts. of alcohol of
99*3 per cent at 14^ C, and in 4867 pts. of the same alcohol at the boiling heat

The crystals do not edffloresce in the air : at 100^ G. they eive off the whole of their
water, leaving the anhydrous chloride in the form of a white mass, which rndta at a
full red heat, and is translucent after solidification. Specific gravity of the anhydrous
chloride = 3*7037 (Karsten), 3*8 (Richter), 3*86 to 4*156 (PoL Boullay). Heated
by itself, it does not become alkaline till after fiision ; but when heated in aqueous
vapour, it becomes alkaline below the -melting point, and evolves hydrochloric add.
By ignition with sulphur it is partly changed into sulphide of barium (Karsten).
It is not decomposed, at ordinary temperatures, by vapour of anhydrous sulphuric add.
According to H. Wurts, it completely decomposes silicates when fused with them.

Ghloride of barium in the state of concentrated solution, is decomposed by nitrate
of potassium or sodium, yielding nitrate of barium and a chloride of the alkali-meta].
It forms a crystalline compound with glycocol. Blood mixed with it remains fluid
and does not putrefy.

The chief use of chloride of barium is as a chemical reagent^ especially fbr the
detection and estimation of sulphuric acid.

BASnrM, CT AVZBB OF. See Gtaitidbs.

BARZVM, BBTBCTZOV IkMH S8TI1CA.TZOW OV. 1. Reaetiont in
the dry way. — Barium-compounds, heated in the inner blowpipe flame, colour the
oiiter flame green. They likewise impart a green colour to the flame of alcohol and
when this flame is examined with a prism by Bunsen and KirchhoflTs method (see
Analysis, Inorganic, p. 214, and Ltoht), a spectrum is seen, having seTeral broad
green bands, in the neighbourhood of Fraunhofer's lines 6, £^ a bright yelloir band
coincident with the line 2), a bright orange band just beyond it) and two £unter
orange-red bands, one of which nearly coincides with the line C,

Se actions in the wet way,^The hydrate, sulphide, chloride, nitrate, and many
organic salts of barium, the acetate, for example, are soluble in water ; most of the
other salts are insoluble in water, but soluble in nitric and hydrochloric add: the
sulphate and the silicofluoride are insoluble in aU acids. All barium-oompounds are
colourless, excepting those which, like the chromate, contain a coloured add. The
soluble salts of barium are poisonous. Solution aS potash (free from carbonate), foi
a precipitate of hydrate of barium, only in very concentrated solutions of barium-salts^:
ammonia forms no precipitate, even in the most concentrated solutions. Alkaline car'
honates form a white predpitate of carbonate of barium, soluble, with efflorescence, in
hydrochloric acid. Phosphate, arsenoiey borate, and iodate of sodium, also form predpi-
tates soluble in acids. Free oxalic acid, or add oxalate of potasnvm, precipitate
oxalate of barium, only from very concentrated solutions ; neutral alkaline oxalates
form a precipitate in all neutral solutions of barium-salts, which are not very dilute.
Neutral alkaline succinates precipitate barium-salts quickly or slowly, according to
the con^ntration of the solutions. Ferrocyanide of potassium forms a predpitate in
moderately dilute solutions ; ferricyamd^ only in strong solutions. Suiphydrk add,
sulphide of ammonium, and perchloric acid, form no predpitates. Sulphuric add and
soluble sulphates, throw down sulphate of barium, from all solutions of barium-salta,
whether neutral or acid. The precipitate is insoluble in nitric or hydrochloric add,
even at the boiling heat. A solution of nitrate of barium, containing only 1 pi
of baryta in 60,000 to 100,000 pts. of water, gives a very distinct doudiness vith
sulphuric acid or sulphate of sodium; with 200,000 to 400,000 pts. of water, after
some minutes only ; and with 800,000 pts, of watisr, the reaction is no longer risible.
(Lassaigne, J. Ghim. m^d. viii. 626.) According to Harting (J. pr. Ghem.xxii
68), a solution of chloride of barium containing 1 pt of baryta in 71,000 pts. of water,
becomes turbid with sulphate of sodium after the lapse of half an hour. Alkaline
chromates form with barium-salts, a yellowish precipitate of chromate of barium, in-
soluble in dilute acids, soluble only in a large excess of nitric add. Hydrojluotilieie
acid forms with barium-salts, after a while, a white crystalline precipitate, nearly in-
soluble in nitric or hydrochloric acid. This reaction will detect 1 pt. of the chliwida
in 3800 pte. of water. The precipitation is accelerated by addition of alcohol

This last reaction afTords a complete distinction between barium and stiontium;

BARIUM: ESTIMATION. 503

the Utter metal not being pecipitoted by bydrofluosilicic acid. The reaction with
sulphuric acid distingmshes bariom in solution from all other metals, except lead and
stzontium. From l^d it is easily distinguished by its behariour with sulphuretted
hydrogen, which forms a black precipitate with lead, and by many other characters.
Sizontaam and calcium are distinguished from barium by the greater solubility of their
Bol^hateay so that a solution of sulphate of strontium, or calcium, added to a soluble
banum-salt^ forms a precipitate of sulphate of barium. Another distinction is afforded
by tJie colour imparted to the flame of alcohol by the compounds of these two metals,
Iniium-compoundB colouring the flame pale green (p. 600), while strontium compounds
colour it deep red. The tabular crystals of chloride of barium, which are nearly in-
soluble in alcohol, likewise afford a means of distinguishing barium from strontium
and calcium, the chlorides of which form hygroscopic needle-shaped crystals, easily
soluble in alcohol.

3. Quantitative Eatimation, — Barium is always estimated in the form of
sulphateu The precipitation is effected by means of dilute sulphuric acid. The acid
must be added in excess, and to a hot solution of the barium-salt ; otherwise a small
quantity of the original salt, espedaUy if it be nitrate, will be thrown down undecom-
poeed together with the sulphate. The precipitate is washed with hot water, ignited
at a moderate heat, together with the filter, and the amount of barium or of baryta
calculated from its weight. 100 pts. of it correspond to 58*78 pts. of barium, and
60-64 of baryta.

This mode of estimating barium is very exact ; but the precipitate, unless certain
pzecautiona are taken, is yery troublesome to filter, sometimes passing through as a
milky liquid, and sometimes completely stopping up the pores of the paper. To ayoid
these isconyeniencies, the liquid must be heated, and the precipitate allowed to settle
down completely, before the filtration is commenced. The clear liquid is then to be
passed through the filter, the precipitate stirred up with boiling water, and again left
to settle down, this clear liquid also poured through the filter, and the same process
repeated three or four times. The result of this treatment is to render the precipitate
dense and granular ; it may then be poured on the filter, and washed with hot water
as aboye-mentioned.

Becent experiments haye shown that sulphate of barium is soluble to a perceptible
extent in strong hydrochloric, and still more in nitric acid (Calyert, Chem. Guz.
1866, 55. — Nicholson and Price, Phil. Hag. [4] xi. 169. — Noad, Chem. Soc. Qu.
J. ix. 25). According to Seigle (J. pr. Chem. Ixix. 144), it is also slightly soluble
in dilute acids, but less in acetic than in hydrochloric or nitric acid. Care must
therefore be taken that the liquid, from which the sulphate of barium is precipitated*,
does not contain too much free acid ; and it must be washed with pure, not with
acidulated water.

Barium may ako be estimated as carbonate; but the method is less accurate
than that just described, because carbonate of barium is not completely insoluble in
water.

4. Atomic Weight of Barium.'^The most exact estimations of this number haye
been made by determining the amount of chloride of silyer obtained by precipitating
pare chloride of barium with nitrate of silyer. In this manner Marignac (Ann.
Chem. Pharm. Ixriii. 215), operating on chloride of barium purified by washing with
aleohol, recrystallisation from water, and drying at a low red heat^ found, as a mean
of six doaeiy agreeing experiments, that 1 pt. of silyer corresponds to 0*96365 pt. of
BaCL Hence, the atomic weight of silyer being 108, we haye :

Atomic weight of BaCl » 0*96365 x 108 « 104*07
Whence deducting • CI • . » 35 50

There remains Ba . » 68*57

In like manner, the atomic weight of barium was estimated by Berzelius (Schw. J.
xz. 1014) at 68*40, and W Pelouze (Compt rend. xx. 1047) at 68*65.

Lastly, Dumas (Ann. Ch. Phys. [3] ly. 129), by numerous experiments made with
chk>ride of barium, carefrdly purified and fused in a stream of hydrochloric acid gas,
has obtained results yarying between the limits 68*47 and 68*56 ; mean yalue » 68*5,
which last number is here adopted.

The atomic weight of barium has likewise been estimated from the amount of
sulphate produced from a giyen weight of chloride ; but the results do not appear to
be so trustworthy as those obtained by the method aboye described.

5. Separation of Barium from other metale. — The precipitation of barium
bj sulphuric acid affords the means of separating it froip all other elements excepting
etiontinm, calcium and lead. From strontium and calcium it may be separated by
hydiofluoailicic acid, which throws down a crystalline precipitate of siiicofluorido of

KX 4

504 BARIUM: IODIDE— OXIDE.

barium 2BaF.SiF'. This precipitate is somewbat soluble in water, but tbe separation
may be rendered complete bj adding alcohol and warming the liquid: from dilate
solutions it takes some time to settle down. It must be collected on a weighed filter,
dried at a moderate heat, and weighed. 100 pta. of it correspond to 49*01 of bariam
and 54*73 of baryta. For other methods of separation, see Calciuic and Stboxtiuil
The separation of lead from barium is easily effected by sulphydric acid, which pre-
cipitates the lead as sulphide.

BASXUSICt VKtrOXZBB OV« BaF. — Obtained by neutralising bazyta-Tatn
with hydrofluoric acid, by digesting the recently precipitated carbonate in Uiatadd, or
by decomposing nitrate of barium with fluoride of potassium or sodium. It is a white
powder, or, when obtained by evaporating the acid solution, a granular ciyBtallioe
crust It is insoluble in water, but dissolves easily in nitric, hydrochloric, or hjdio*
fluoric acid.

Fluoride of barium unites with the fluorides of boron and silicon, forming the eom-
pounds BaF.BP and 2BaF.SiF'. The latter is nearly insoluble in water, and sarn
for the separation of barium from strontium and calcium, p. 502 (see Bobofluobidbb
and SiLicoFLuoRiDEs). It also forms a crystalline compound with chloride of hsriam,
BaCLBaF, which is produced on mijdng a solution of fluoride of potassium or fluoride
of sodium with chloride of barium. This compound is more soluble than the fluoride
itself, and remains as a granular mass when the solution is evaporated.

BAXrmiK ZOBIBB OV. Bal. — Formed when hydriodic acid gas is pissed
over baryta at a red heat» the combination being attended with production of light
Protosulphide of barium dissolved in water is mixed with a saturated alcoholic
solution of iodine [iodine without the alcohol might be preferable], as long as a pre-
cipit^ite of sulphur is formed ; the colourless filtrate is boiled rapidly — so as to prerent
the action of the air — almost to dryness ; the mass is dissolved in a small quantity of
water, and filtered quickly ; and the filtrate is evaporat«d to dryness in as short a
space of time as possible in a glass bolt-head. (O. Henry.)

On redissolving the mass in hot water and leaving the solution to cool, the hydnted
salt crystallises in slender deliquescent needles containing, ac(X>rding to Croft (Chem.
Gaz. 1856, p. 125), 2BaI.7H'0 ; they dissolve readily in alcohd Heated out of
contact with the air, they leave the anhydrous 8alt> which is not decomposed by heat
in a close vessel, but in contact with the air, decomposes slowly at ordinary tempen-
tures and quickly when heated, giving off vapours of iodine and leaving baryta.

BAAZUM, OZZDB8 OV. Barium forms two oxides, a protoxide, BaK), and a
dioxide or peroxide, BaO ; the first produced by the direct oxidation of the metal, or
hj heating certain of its salts ; the second, by heating the protoxide to dull redness in
contact with excess of oxygen.

pROTOXiDB OF Babium, Or Babtta, Ba*0, or BaO. Barytea, Ihrapond&rm,
Terre phante, Scktvererde. — Barium oxidises rapidly in the air, even at ordinaiy
temperatures, and when heated, bums with a dark-red light and is completely con-
verted into anhydrous baryta. This oxide is however more readily obtained by igniting
the nitrate or carbonate of barium.

Preparation. — 1. Nitrate of barium is beated in a porcelain crucible, or better in a
porcelain retort, till it is completely decomposed, and no more red vapour or free
oxygen is given off. The heat should be moderate at first, because the nitrate fwes
and froths very much; but towards the end of the process, it must be raised to hrigbt
redness. If the heat is too long continued, the baryta is apt to absorb carbonic add
and oxygen from the fire.

It is not convenient to use a platinum crucible in this process, because baiyta attacb
platinum rather strongly at high temperatures, and if a Cornish or Hessian cnidhle
be used, the baryta becomes contaminated with silica, alumina, oxide of iron, and
other matters derived from the crucible. A porcelain vessel is attad^ed in the same
manner, though less strongly, and the baryta prepared in it always contains ^nall
quantities of alumina and nlica. This contamination, and likewise the inconTenienoe
arising from the frothing of the mass, may be obviated in some cases by mixing the
nitrates with rather more than its own weight of pounded sulphate of barium (hesvy
spar). Such a mixture does not fuse, and may therefore be heated in an earthen
crucible without attacking it (Mohr, Ann. Ch. Fharm. xxvii. 27). This process is
very convenient whon the bai^ta is to be used for purposes for which the presence of
the sulphate is not objectionable, as for preparing baryta-water or the hydrate.

2. On the small scale, baryta may be conveniently prepared by igniting the iodate
of barium, which readily gives up all its iodine and f of its oxygen without fusion or
frothing (2lO*Ba = Ba«0 + PO*).— 3. Carbonate of barium exposed to the strongest
heat of a forge-fire is converted into baryta ( Abich), and at an ordinary white heat,
when mixed with ^5 of its weight of lamp-black or charcoal, and made into a thick

BARIUM: OXIDES. 505

paste with oil ; the mixture should be heated in an earthen crucible lined with larap-
olack, and having a close-fitting cover. Baryta is prepared by this process on the large
scale from Withcrite, to be used in separating crystallised sugar from molasses
(Leplay and Dubrunfaut^ SilL Am. J. [2] xvi. 276)« Baryta is also prepared on
the lazge scale by igniting a mixture of the carbonates of barium and calcium in a
eanrent of aqueous vapour. (Jacquelain, Compt rend, xxxii. 877.)

Properties. — Ghreyish-white, friable mass, of specific gravity 4-7 (Karsten); 6'6i,
(Filhol). It is strongly alkaline, caustic, and poisonous. It melts only at the
strongest heat of a forge-fire^ or in iJie flame of the oxyhydrogen blowpipe, forming a
lead-grey slag. It is a non-conductor of electricity, but may be decomposed by the
electric coirent, with the intervention of mercury, yielding barium and oxygen (p. 560).
Potassium deoxidises it at a red heat Heated in vapour of sulphide of carbon, it forms
carbonate and sulphide of barium :

3Ba«0 + CS» = CO«Ba« + 2Ba«S.

With water, it forms a hydrate (see below). It unites with alcohol and wood-
spirit^ fonning the compounds Ba'0.2C'IP0 and Ba*0.2CH*0. It dissolves readily
in dilute nitric and hydrochloric add, and in some other acids ; with many acids,
it forms insoluble salts. When vapour of sulphuric anhydride is passed over baiyta,
heated to low redness in a glass tube, combination takes place attended with incan-
deseence, and sulphate of barium, SO^a', is produced.

OxiDB OP Babiuk and Htdboobn; Htdbatb of Babivx, BaHO or
BaO,HO. Hydrate of Baryta, Caustic Baryta, Hydrated oxide of Barium, — Fonned
by tiie action of water on anhydrous baryta (Ba'O + H^O — 2BaH0). When anhy-
drous bazyta is sprinkled with water, the hydration takes place^ with great evolution of
heat and expansion of volume. Anhydrous baiyta also rapidly absorbs water from the
air. The hydrate is usually prepared by heating a solution of sulphide of barium (ob-
tained by igniting the native sulphate with coal or charcoal) with oxide of copper, till
a filtered portion of the liquid gives a white instead of a black precipitate with lead-
salts, — Another mode of preparation is to decompose the nitrate of barium with
caustic soda. A solution of soda of specific gravib^ 1*10 to 1'15, whose strength has
been previously determined, is mixed with an equivalent quantity of finely pounded
nitrate of barium, the liquid being kept in a state of ebullition, and water being added
from time to time in small portions to facilitate the solution of the nitrate; and when
the whole is dissolved, the boiling liquid is rapidly filtered, if necessary, through a
folded filter into a bottle which can be well closed. On cooling, it deposits an abundant
crop of crystals of the hydrate, which may be fr«ed from the mother-Uquor by draining,
or better by means of a centrifugal machine. The crystals retain but a very small
quantity of nitrate, and may be fireed from it by recrystallisation. Chloride of barium
may also be used in this preparation, instead of the nitrate, but the presence of small
quantities of chloride of sodium in the product is more likely to be aetrimental in the
use of the baiyta, than that of the nitrate. (Mohr, Arch. Pharm. [2] Ixxxviii. 38.)

Hydrate of barium czystallises from its aqueous solution in transparent, colourless,
four or six-sided prisms with four-sided summits. They contain 4 at water : BaHO
4HK); dissolve in 20 pts. of water at 15° C. and in 2 pts. of boiling water. Tlie
aqueous solution. Baryta- water, has a strong alkaline reaction, is highfy caustic, and
rapidly absorbs carbonic acid from the air, forming a film of carbonate on the surface.

The crystals are efSoreecent and in vacuo over oil of vitriol, give off { of their water
of ciystallisation, leaving 2BaH0.H'0. At 100° C. they melt, giving off 1 at nrater,
and at a red heat, the remainder of the water of ciystallisation is given ofi^ leaving
the pure hydrate BaHO (Bloxam, Chem. Soc. Qu. J. xiii 49). This, when heated
alone, is not reduced to anhydrous baryta below a red heat, but when heated in a
stream of carbonic anhydride, it is easily converted into carbonate of baiium, with
elimination of water:

2BaH0 + CO* « CO»Ba« + HK).

Heated in s cnnent of air, it takes up oxygen and is converted into peroxide of
iMuium, also with elimination of water. (Boussingault.)

2BaH0 + O « 2BaO + H*0.

Hydrate of barium is extensively used as a chemical reagent, viz. for the estimation
of carbonic acid, for precipitating metallic oxides, and especially for separating mag-
nesia from the alkalis.

Pbboxxdb of Babiuv, BaO or BaG^. — ^Produced by heating anhydrous baiyta
or hydrate of barium to low redness in a current of pure oxygen, or of air frre
from carbonic acid. Pure anhydrous baiyta absorbs oxygen with facility ; the hy-
drate less readily, because it melts at the temperature required for the absorption :

606 BARIUM: PEROXIDE—PHOSPHIDES.

•

the absoiption may hoireyer be rendered rapid by mixing the hydrate of barinm with
lime and magnesia in sufficient quantity to prevent fosion, and keeping the mass in »
porous state, so that the oxyeen may penetrate it thoroughly. Peroxide of barimn
may also be produced by sprinkling red-hot baiyta with four times its weieht of
pounded chlorate of potassium in successiTe small portions. Chloride of potaanimi is
formed at the same time, and on washing out uiis salt with water, tne peroiide
remains in the form of a hydrate.

Peroxide of barium is a grey powder, somewhat more fbaible than anhydrous liujta.
At a strong red heat, it erolves oi^gen and is conyerted into bai^ta, and when Tspoar
c^ water is passed oyer it at a red heat, it likewise giyes up half its oxjgen and is oon-
yerted into nydrate of bariuuL The absoxption of oxygen by hydrate of bariom at a
red heat, and its subsequent evolution when the residtin^ peroxide is heated is a
stream of aqueous vapour, has been proposed by (Bonssmgault, Ann. Ch. Fhys.
[3] XXX. 6) as a means of extracting oxygen from the air by a oontinaoos pmm
Hydrate of barium mixed with lime and magnesia, as above described, is heated ia a
porcelain tube through which a current of air previously freed from carbonic arid is
drawn by an aspirator : and as soon as the conversion of the hydrate into peroxide is
complete, the current of air is stopped, the temperature is raised, and vapour of vater
is passed through the tube as long as oxyeen continues to be given off. Anhydfoas
baryta may also be used instead of the hy&ite, being first converted into peroxide ss
above, and the peroxide then decomposed by heating it to bright redness withoat
passing aqueous vapour over it : but the temperature required for this decomposition
18 much higher ; and moreover if the baiyta contains small quantities of silica and
alumina, which is often the case, it cakes into a very hard mass after freauent exposon
to a high temperature, and will then no longer absorb oxygen with £Mility.

Peroxide of barium is readily decomposed by carbon, phosphons, solphv, Hy-
drogen, and the metals, at a red heat, and by sulphydric acid at ordinaiy tempenton&
Heated over a large spirit-lamp in a rapid current of carbonic oxide, it becomes white-
hot, and at the same time small white flames burst out from its sur&oe, probaUr
arising from the evolution of oxygen from the still undeoomposed peroxide. A similar
but more brilliant appearance is presented when the peroxide is neated in solphimnu
anhydride (Wohler, Ann. Gh. Pharm. Ixxxviii. 126). In contact with strong supbinie
acid, it gives off oxygen at ordinary temperatures or when gently heated. uth» tem-
perature of the mixture does not exceed 60^ or 60^ C, part of the oxygen is oTolted
in the form of oeone ; but above 70° C, nothing but ordinary oxygen is evolTed.

Peroxide of barium thrown into water difihses itself through tibe liquid and forms a
hydrate, probably containing Ba0.3H'0. The same hydrate is precipitated in crys-
talline scales when peroxide of hydrogen is added to strong bazyta-water; it is
slightly soluble in cold water, but decomposes at the boiling heat, yielding free oxygen
and hydrate of barium.

Both the anhydrous peroxide and the hydrate dissolve in excess of water addolated
with hydrochloric acid, forming chloride of barium and peroxide of hydrogen, withoat
evolution of oxygen (BaO -i- HCl « BaCl + HO). When the peroxide is mixed
with acidulated water in presence of oxide of silver, peroxide of manganese, peroxide
of lead, &c, oxygen is evolved, both from the peroxide of barium and from the other
oxide, so that tne peroxide of barium here acts as a reducing agent (see Choocal
AFFOnTT and Phrozidb of Htdrooxn). Oxide, chloride, sulphate, or carbonate of
silver, introduced into an acid solution of peroxide of barium, is partly reduced to
metallic silver, the quantity thus reduc^ being, however, always less than that which
is equivalent to half the oxygen in the peroxide of barium (&iK).0). The quantity
reduced increases with tiie amount of silver-salt present^ and diminishes as the tern*
perature is higher. A small ouanti^ of the silver-compound, or of any similar sab-
stance, is capable of decomposing a large quantity of peroxide of barium. Iodine, on
the other hand, decomposes an exactly equivalent quantity : BaO -i- I * Bal •¥ 0.
(Brodie, Pha Trans. 1860, 769.)

mAJtZVMy OZTCHDr-BAlflTB OV. The general characters and reactions sie
described at p. 602. For the special descriptions, see the several Acids.

AAJtZUMv OXTBVIiFBZBBS OV. A solution of sulphide of barimn in boil-
ing water, left to stand in a close vessel, first deposits crystals of hydrate of barium, and
the liquid decanted therefrom yields scaly crystals, whose composition is nearly ex-
pressed by the formula Ba^S'O'.eSHK), and afterwards granular crystals, eonsistingflf
fea*SO.10H»O. A moderately concentrated solution of the sulphide deporits, after
about two months, large transparent tabular crystals, having the form of a heugonal
dodecahedron, with truncated summits, and containing Ba'&0.28H*0, or Ba*0.lOHH)
+ SCBa'S.eHK)) (H. Rose). These oxysulphides are very easily decomposibla, being
resolved by hot water into hydrate and sulphydrate of banum, of which, perhaps, they
are merely mixtures.

BARIUM: SELENIDE— SULPHIDES. 507

I OF« BaP? — When vapour of phosphorus is passed
orer red-hot boiyta, a hrownish-red mixture of phosphide and phosphate of barium is
obtained, Gommonlj ca]led pkosphuret of baryta, the reaction perhaps taking place in
the mannw* represented by the equation :

4BaH> + 6P - 6BaP + PO^a».

It is decomposed by water, formine a solution of hypophosphite of barium, and giv-
ing off a mixture of spontaneous^ inflammable pnosphoretted hydrogen gas and
free hydrogen.

BAJUVaiy MMXtMMTDM OF. Ba'Se, or BaSe, — ^Produced by exposing selenite of
barium to a red heat in contact with hydrogen gas or finely divided charcoal (lamp-black).
It is soluble in water, but decomposes at the same time, like the monosulphide, yield-
ing hydrate of barium, and a higher selenide of barium, the solution of which is de-
composed by adds^ with evolution of selenhydric acid and precipitation of selenium.

BASZ1IBI» SV&VBZBBB OF. The protosulphide, Ba'S, or Ba8, is ob-
taiaed by passing sulphydric add or vapour of sulphide of carbon over red-hot baiyta^
or by re^acing pulverised sulphate of barium in a stream of hydrogen or carburetted
hydrogen. Either of these processes yields a veiy pure product ; but for preparation
on the larger scale, the native sulphate of barium is heated to bright redness with
cairbonaoeons matter. If charcoal is used, it must be thoroughly well incorporated
with the heavy spar, otherwise the reduction will be imperfect, as no fusion takes
place. The adiouxture of resin, oil, or starch is advantaeeou^ to bind the mass toge-
ther and produce partial fusion; but a much better method is to mix the powdered
solphate with about | of its weight of bituminous coal, and heat tiie mixture in a
eracible to full redness for an hour ; the tarry matter of the coal then penetrates
thoroughly into the mass, so that every partide of the sulphate comes wdl m contact
with the reducing matter.

The mass thus obtained consists of sulphide of barium mixed with excess of car-
bonaeeous matter and undeoomposed sulphate ; the sulphide of barium may be ex-
tracted by treating the mass with a suffident quantity of hot water, and crystallised.
Another method is to ignite a mixture of 100 pts. heavy spar, 200 common salt, and
16 pts. chaicoalpowder in a reverberatoiy furnace, and extz^t the sulphide of barium
by hot water. The use of the chloride of sodium is to promote fusion. (Ku c zinski,
Bepertoiy of Patent Inventions, 1836, p. 161.)

Pure sulphide of barium is a white mass, having a hepatic odour and alkaline taste,
and easily soluble in water. Exposed to the air, it absorbs water and carbonic add,
and is converted into carbonate, with evolution of sulimuretted hvdrogen. When
heated in the air, it oxidises but slowly, but when heatea to redness m an atmosphere
of aqueous vapour, it is converted into siilj^hate of barium, with elimination of hydrogen.

Sulphide of barium dissolved in water is easily decomposed by boiling with oxide of
copper, oxide of iron, S^c, forming hydrate of barium and sulphide of copper, &c.
aydroeldoTic, nitric, carbonic acid, $c, decompose it, eliminating sulphuretted hydrogen,
and forming chloride, nitrate, &c. of barium. Chlorine, bromine and to(2tn« decompose
it, with formation of the corresponding salts and deposition of sulphur. Sulphide of
barium is indeed the material most generally used for preparing the other compounds
of barium.

A mixture of sulphide of barium with the sulphate, such as is obtained by igniting
the sulphate with an insufficient quantity of carbonaceous matter (gum-tragacanth
answers well, because it forms a paste with the heavy spar), acquires bv exposure to
the son's rays the property of shining in the dark : it is called the Boiognian phoe-
pkonu.

With waier, protosulphide of barium forms hydrate and sulphydrate of barium :

Ba*S + H«0 - BaHO + BaHS.

The quantity thus decomposed varies with the quantity and temperature of the
water. When crude sulphide of barium, prepared by igniting the sulphate with
earbonaeeous matter, is treated nine times in succession with a quantity of cold
water lees than suffident to dissolve the whole, the mass being digested for twenty-
four hours each time in a dosed vessel, the first two solutions obtained are of a
pale yellow colour; yidd a large quantity of sulphuretted hydrogen and a pre-
dpitate of sulphur, when treated with hydrodiloric acid; and form with chloride
of manganese, a fiesh-coloured precipitate of sulphide of manganese mixed with free
sulphur, sulphuretted hydroffen odng likewise evolved : hence these solutions contain
sulphydrate of barium (BaHS) together with a polysulphide of barium. The third
solution behaves like a solution of protosulphide of banum containing a slight excess
of sulphuretted hydrogen. The fourth is of the same character, but contains at

508 BARIUM— BAROMETER.

slight excess of baryta. Tliis excess goes on continoaUj inereasbg in the fiitii, sixth
and seventh solutions : and the eighth and ninth b^iaTe like pore baiyt^-vater,
yielding with chloride of manganese a white precipitate of manganons oxide. If the
crude sulphide is at once treated with a quantity of water sufficient to diasolve the
whole of the sulphide, the solution exhibits the characters of the pure piotosolphide:
it may however be a mixture of hydrate and snlphydrate of barium (see the aboie
equation). A solution of sulphide of barium in not too large a quantity ol vater,
kept for some years in a stoppered bottle, deposits, first crystus of hydrate of hsxism,
then scales which are a mixture of crystallised hydrate of barium and the hjdnit«d
pTotosulphide (Ba'S.SHK)), and afterwards double six-sided pyramids containing the
same substances, but much richer in sulphide of barium. The mother-liquor boiled
down in a retort, evolves a continuous current of sulphuretted hydrogen, and on cooling
deposits hydrated sulphide of barium in the form of a white powder, while sulphide of
barium and hydrogen remains in solution.

Htfdrated Sulphide of Barium^ Ba'S.3H'0, is a white powder, which soon tons
yellow. When treated at once with a qtiantity of water sufficient to diasohe it
perfectly, it yields a solution which when mixed with a manganons aalt^ yields a pre*
cipitate of sulphide of manganese (Mn*S) without evolution of sulphuretted hydrageo:
but a smaller quantity of water extracts snlphydrate of barium and leaves hjdxate of
barium undissolved.

Snlphydrate of Barium^ BaHS, ot Ba8,H8. — ^Baryta-water, or protoealphide of
barium reauced to a paste with water, and warmed, is saturated with solphydric acid, the
solution evaporated apart from the air, and cooled, when crystals of baryta and jdlov
prisms are formed. Tne remaining liquid is either evaporated in a confined space, vfan
white opaque prisms are obtained, or mixed with alcohol, filtered from the solphor
and hyposulphite of barium produced by air contained in the alcohol, and cooled
down to — 10^ C. ; in this way, colourless and transparent four-sided prisms are pro-
duced. Also when baryta or either of its hydrated compounds is allow^ to OTStallise,
together with sulphide of barium, frt>m an aqueous solution of protosolphideof banmn,
by evaporation in a retort and cooling, and the residual liquid (which is of a jellowish
colour, from the air not being perfectly excluded) farther evaporated and cooled, it
solidifies to a crvstalline mass of snlphydrate of barium (H. Hose). The or^
contain water, which they lose when heated, becoming white at the same time. When
exposed to the air, they effloresce and turn white, while hyposulphite and sulphate of
barium are formed. In a retort, they lose their water of crystallisation without fusiof^
and then evolve sulphydric acid as the temperature approaches redness, leaxing dark
yellow protosulphide of barium, which becomes white as it cools. An aqueous smtm
precipitates chloride of manganese, with escape of sulphvdric acid gas (Berzelia^
Pogg. Ann. vi 441). The salt, when boiled, evolves sulpnvdric acid. Withiodiix^it
forms iodide of barium and free hydriodic acid, sulphur being set free. It is iosoluble
in alcohol. (H. Rose.)

Trieulphide of Barium, Ba'S', is said to be obtained, together with sulphate, hy
igniting 8 pts. of baryta with 6 pts. of sulphur, 1*78 pts. of the sulphur volitiliBiBg
during the process. On treating the proauct with water, the trisulphide dissolTei
and 2*8 pts. of sulphate of barium, remain behind (Van quel in). When the
moistened trisulphide is heated to redness and vapour of water is passed OTer it, sol-
phuretted hydrogen is given off, and sulphate of barium is formed. (Gay-Lussac.)

Pentaaulphide of Barium, Ba-S*, is obtained in solntiofi, by boiling the noto-
sulphide or the snlphydrate with sulphur (H. Rose); also, together with hyposulphite
of barium, by boiling baryta-water with sulphur. The solution is yeUow, bitter,
alkaline and caustic ; leaves a pale yellow amorphous mass when evaporated in tanw;
and is decomposed by exposure to the air, with deposition of sulphur and foimation of
hyposulphite of barium.

See Cebeals.

BAJUrBAmDTITB. A sulphide of copper and iron, 2Cu<S.Fe^*, eontaining
traces of silver, found in a mine in Bamhardt*s Land, and other localities in North
Carolina. Bronze-yellow, with metallic lustre, sometimes dull and opapue. Fitctun
concho'idal ; no cleavage. Specific. gravity 4'621. Hardness « 3-5. Brittle, Stiw
greyish-black, somewhat shining. Tarnishes in the air, especially in contact with
moisture, acquiring a brown or rose-red colour. Before the blowpipe, it gives the
reactions of iron and copper, (Genth. J. pr. Chem. Ixiv. 468.)

L Syn. with Babttocalcitb.
Syn. with WiTHKRrrB.
{0apos weight and fArrpov measure). The barometer is an iwtn-

BAROMETER. 509

ment employed to measure the pressure or weight of the atmosphere. It consists essen-
tially of a oontinuoiis body of liquid, generally mercury, from one part of the upper
nirlace of which all pressure is remoyed, whUe the atmosphere still presses upon the
remainder of the surface. It is a law of hydrostatics that, in a heavy fluid, the pressure
at all points in a horizontal plane must be uniform, in order that there may be equi-
librium. The surface of the mercury cannot, then, remain in one plane, as it does
when the atoiosphere presses equally on every part, but it must rise where protected
from the atmosphere, until the pressure of the portion thus rising exactly balances
and replaces the pressure of the atmosphere. Thus in fig, 92, the surface of mer-
cury on which the atmosphere presses is at a, and the glass tube ▲ b, haying been
perfectly emptied of air and every other fluid, the mercury has risen to b, so that the
perpencUcnlar column of mercury ▲ b exerts a pressure at the horizontal plane a, exactly
eqoal to the pressure of the atmosphere at A.

Now supposing mercury to be always of one specific gravity, the length of the
barometric column will be exactly proportional to tiie weight or pressure of the atmo-
sphere, and thus a length expressed in inches or parts of a metre becomes a convenient
expression for a weight. It is well, however, to bear in mind the real pressures indi-
cated, which are eaaly determined, as in the following example: —

29'872 inches » mean height of barometric column for noon at Greenwich.
13*668 s specific gravity of mercury at 60^ F.
997*137 oz. avoirdupois — weight of one cubic foot of water at 62^ F.

29-872 X 13-568 x 997137 ^.^o c^^ra -la a^*, ^^^ *x.

--7 -^ ^rr = 233*879 oz. « 14-617 lbs. the average atmo-

12 X 12 X 12 ^

spheric pressure for noon at Greenwich on every square superficial inch.

Barometer at 28 inches Atmospheric pressure 13*70 pounds

t» it 29 „ „ „ 14*19 „

n M 30 „ „ „ 14*68 „

If If 31 „ „ „ 16-17 yf

When any other liquid, is used, the height of the barometric column will be in-

Tersely as the specific gravity. Thus the height of a column of water corresponding

1 ^'^Afi
to 29-872 inches of mercury at fiO® F. is 29-872 x ^,^^^, or 406-3 inches or 33-77 feet ;

similarly a column of sulphuric acid would stand 29*872 x g. , or 219 inches high.

A fnll account of a' water barometer constructed for the Boyal Society by Professor
Baniell will be found in Phil. Trans, czxii. (1832), 639.

CoKSTBrcnON of the Babombteb. — AH that is necessaiy to construct a barometer is
to seal a glass tube about three feet along at one end, to fill it perfectly with mercuiy,
and putting the finger over the open en^ to invert the tube into a vessel of mercury.
On withdrawing the finger, the mercurial column descends a few inches, and ameasm*e
being applied, the height of the column remaining is found. But to attain accuracy,
great precautions are required at every step.

If any air remain in the tube, by adhenng to the ^lass, it will rise into the space
above the mercury, and its pressure, partly counteractmg that of the atmosphere, will
depress the barometric column. Most of the air may be got out by^ shaking the
mercnry in the tube, but some will certainly remain, to eliminate which, the tube
must be boOed as follows : — ^Fill only about six inches of the tube with mercury, and
gradually heat it over a strong flame or a charcoal fire until the mercuiy has boiled
for a few moments. At the same Ume, heat another portion of mercury, that it mapr
not crack the hot tube, and with it fill a few inches more of the tube. Expose this
new part diiefiy to the fiame until it boils, and thus proceed, alternately pouring in a
little mercury and then boiling, until the tube is almost fall. It would be well to
anneal the tube, if a large one, while cooling, to prevent fracture. When cold, fill it
entirely with mercury, ^ready boiled, and invert, with great precautions, to prevent
entrance of air. Any kind of dirt entering also will prove very detrimental, and the
tabe, in the first place, before sealing, should be thoroughly sponged out with whiting
and spirits of wine.

The mercury used must be perfectly pure^ otherwise it will be thick, sluggish, and
dirty, as well as somewhat false in specific sravity. To purify it, agitate with diluted
nitnc acid or sulphuric acid, and keep it under the acid, if possible, for a week or more,
afterwards washing with fresh acid and distilled water. Carefully distilled mercuiy
is pure enougli, except that the dissolved oxide of mercuiy must be removed by treat-
ment with sulphuretted hydrogen water, or dilute sulphide of ammonium.

Many forms of the >>arometcr have been contrived since its first discoveiy by Torri-

£10

BAROMETER.

eelli ; but, wuept in rendering tlie inBtrnment portable uid nruItsnblB, no inproTt-
ment hoa e*er, or perhapa csa erer be laiute on the onginsl siinple foim. In tiel, tl»
most perfect boroaivter existing, the Great Standard at ths Slew Oiiaemiacj, moi.
tionea further on. i> also the most timple that contd be imagined.

We Bhall, Uieiefore, content oonelveB vlth deecnbing those fonns of the banaeta
which can be rocommended to the obaerrer of the preaent daj toi theii aesuvj lad

Figt. SS— B3.

In fy. 83 is shown the Pobtablb Stuhilrd Sabombtek. ai first innnted bjFintui
of Fans, and nov made, amongst others, by Negretti and Zambn of Hstton Qtiia,
London, at a cost of eight gniness.

The baiometer tube baa an internal diameter of SB or -40 inch, uid tbe lii i> {f
fectly driven out by the usual procna of boiling. The cistern (Jig. 89) u ampod
partly of aglaas i^linder o, of boiwood sides and top, wand w*. andof ■leatbrab*,'-
the bottom of which can be raised or lowered by Uie finger-screw, s. Tbs »lwle "■
of comse, held together bj a brass casing, and the baiometer tube, the lora ai <i
which is contracted, is connected with the cistern by a leather joint atM.

To make au observation of this barometer, the lower sar&ce of the memry no^
first be a<)juated so as just to touch the ivoiy fidudal point f (fig. S9\ ij limiii!
tJie Bcrew s. The moment of exact contact may be veir accurately olaeiTed if <)••
mercury be properly clean and bright, by watching whan the ivory point and ilj
reflection just meet ; if the mercury be even ^^ of an inch too tow, liglit nil
appear between the point and mercury ; while, if too high, a sniall depRSM*^
instantly detected by reflected light, will be caused in the mercurial mAce by tbi
ivory point

Next, tJie upper snrface of the mercurial column is observed by ai^nstiog th« km
edge of a moveable brass cylinder, so that it shall visuaUj be the tangent to, thit u
shall just touch, the curved Burface of the mercnrj. To avoid the error of panlUi,
the line of vision must be exactly horiaintttL The scale of indies, with the u

of the vernier engraved on the moveable c]" " ■ -"

column, subject to index error, within tt
« little practice, will soon discriminate 1

A Barrmeter thovld neew be carried aimti Vn t<» ^rdinari/ t^rigii pmiUfi '

■ horiHintttL The scale of inches, with the lausin™
oveable cylinder, then gives the aetnal beigbt «i 1m
thin the ^ part of an inch. Bnt tboolserrw, wU"
inate the j^ part by the nslied ^e.

BAROMETER. 611

the merenrial colman, being delicately balanced against the weight of the air, will be
foimd to vibrate, or as it is said, to pump rapidly up and down when the barometer
sofiers any vertical disturbance. Not only might bubbles of air adhering to the lower
part of the tube be thus carried up^ but the mercuiy violently striking the sealed
and vacooos end, might shatter a tube that was not very strong. To rendex this
barometer portal^e, the handscrew at s must be screwed up, and the instrument
gently induied at the same time, imtil the mercmry fills the whole of the tube, and
almost the whole of the cistern ; it is then to be inverted and kept or carried about as
nearly as possible in this position until again safely suspended. A board and bracket,
not shown in the figures, accompany this barometer, as also an arrangement of
three screws, by which it may be secured motionless in the vertical position, which it
of course assumes when firee. Such a barometer is very suitable and quite good enough
for a laboratory, or for a series of meteorological observations. It is the form of baro-
meter most esteemed on the Continent.

Of MocTiTAiN Basombtbbs, which require to be fiur more portable and secure from
accident than that above described, the best is 6ay-Lussac*s form (see Ann. de
Chimie, 1816, i. 113), as improved by Bunten, and drawn in>^. 90 from an instru-
ment by Negretti and Zambra. Its tube is in the form of a syphon, of which the
parts D B and f o have an uniform diameter of '2 inch, while the part b f is a capil-
lary tube, with a bore of about *05 inch. The end of the tube at o is sealed, but a
minute and somewhat sunken h<de is pierced about an inch below the end, so that air
may pass freely in or out, but not the mercury. At b is a pipette or air trap, shown
on a Urger scale in fig. 91, contrived by Bunten, so that even if air pass up the tube
B F, it will collect at b, since it is scarcelv possible that it should find its way through
the capillary communication (h, fig, 91) into the upper part of the tube.

The tube is loosely pecked in a brass tube-case, through two alits in which the
npper and lower surface of the mercury may be observed in the same manner as the
upper surfiu» in the Fortin barometer. There are two divided scales, both 9 inches
long^ and measured from the lowest point of the lower scale, and the difference of the
readings is the height of the barometric column. The verniers read to the ^^ of
an inch.

Kbwicax's Standabd Babokbteb is well known, and has long been relied upon in
other countries as well as this. The tube has a diameter of S or '6 inch, and stands
in a plain cylindrical glass cistern. The graduated scale is of brass, affixed to a brass
rod passing down the inside of one of the upright supports, and terminating below in
a conical ivory point, which by an endless screw and wheel is very accurately ad-
justed to contact with the mercury. In this respect the construction is superior to
that of the Fortin barometer, because the mercury when raised or lowered, as in the
latter, may not at once assume its true position, owing to adhesion. Mr. Newman has
adopted a method of filling his barometer-tubes in vacuo, and of boiling tiiem under
diminished pressure, which obviates all oxidation and fouling of the tubes.

Tbb Gbbat Stahdabd Babombtbb of the Kew Observatory, constructed by the
late Mr. Welsh, has a tube 1*1 inch in bore, and as it was found impossible to fill so
large a tube satisfiEictorily in the ordinary way, the following excellent method was
adopted : — To the upper end of the barometer tube ▲ b {fig. 93) was attached a
capillary tube A n b f, much contracted at d, with a small bulb at b, drawn out at f
to a fine point, and hermetically sealed. To the lower end of the large tube was
attached 10 inches of a smaller tube boo, having a bore of 0*3 inch, and to that
again 'w^u added about 6 inches of capillary tube oh. A bulb of { of an inch was
blown at o, and the small tube finaUy bent into a syphon form at b. The end h of
the capillary tube was now connected with a good air-pump, and the air very slowly
extracted, at the same time that the whole tube whs strongly heated by passing a
large spirit fiame along it. ^ When the air had been as well as possible extracted, and
whUst the pump was still in action and the heat still applied, the capillary tube o h
was sealed at i by a blowpipe flame. When the tube had cooled, it was placed at a
small inclination with the end f in perfectly pure mercnry, which had been previously
boiled, and the point bein^ broken ofi^ the mercury rose until the bulb at o was more
than half filled. The point f was then again sealed, the capilhur tube remaining
quite filled with mercury. When the glass at f had cooled, me whole tube was in-
verted, the mercury now separating at the contracted part d, leaving the tube from d
to F filled, or very* nearly so, and from d to a perfectly vacuous. The operation was
completed by sealing the tube at x, removing the portion x d b f, placing tiie bend b
in the cistern of the barometer, and breaking off the tube o o at the point a

The tube finally adopted at Kew, is perfectly free from air in the portion b, which
is 9 inches long ; it is mounted in an open brass frame {fia. 92), acHusted to verti-
eality bj screws at s ; at c c' are two steel rods, the first terminating below in a conical
pointy the aecond in a knife-edge, and both adjusted so as just to touch the surface of

612 BAROMETER.

the mercury in the cistern. The height of the mercurial column is then easQy obeerred
by a cathetometer placed flye feet off, the telescopic wire of which is made alternately
to bisect a mark on the head of the rods o or o', and to form a tangent to the mercuul
surface at b. The difference of the readings on the divided scale of the cathetometer,
added to the known length (3*615 for c) between the point and end of the steel rod,
and the mark on its head, gives the actual length of the barometric oolnmiL The
cistern of this barometer stands 33*9 feet above the mean sea-lereL (FhiL Tnni.
[1856] p. 507.)

A very interesting account of the construction of the Boyal Socie(/t Standard
barometer by Daniefl, will be found in his Meteorological Essays, p. 353. See al»
Mr. Bail/s Description of a New Barometer, PhiL Trans. czxviL 431 ; and Hndflos,
Phil. Trans. [1832] p. 575.

We will now consider the precautions and corrections necessary in obtamingthe tnie
atmospheric pressure with exactness.

CoBBScnoN FOB Gapaoitt. — It is obvious that in proportion as the barometer
stands higher, so much more mercury there must be in the tube, and oonseqaentlj so
much less in the cistern. We should not then get the true variations in the length of
the mercurial column, by noticing the top of the column only, since the base of thf
column also varies, and a correction must obviously be made for the amonnt of the
variation.

This correction, indeed, is not required in any of the barometers above described,
because observations or adjustments are made both at the upper and lower antfaees
of mercury. But in many other barometers, the scale is measured tmlj from
the lower surface of the mercury, only when the column is at one particular height,
called the neutral pointy usuaUv determined by the barometer-maker, and marked oa
the instrument. When the column is higher or lower than this point, the meztnu; ia
the dstem must be lower or higher in a proportion depending on the sectional areas
of the tube and cistern. If £f be the height of the neutral point, and h the obserred
height of the barometer, the correction for capacity is

! diameter of tube { '^ ^ __
diameter of cistern ) ^ '

In the marine barometer adopted by the Board of Trade, this correction is actoaOf
performed upon the divided scale, so that the inch divisions are aboat } less thaa
real inches. In any syphon barometer, like that of Gay>Lussac, in which both kgs
are of equal diameter, the correction for capacity is made by doubling the variatioaf
in height of one surface, and Chiy-Lussac recommends this method when great nicety
is not required; but measurements of both surfaces are evidently neceasaiy for
certainty.

CoRBBGrnoN FOB TsicPBBATUBB. — The length of the barometric column is propo^
tional to the pressure which it has to measure only so long as the specific gravit/ of
mercury is constant. Now mercury expands ^ossv ^^ ^^ ^^^ volume when its
temperature rises one degree (Fahr.), and its density of course varies invenelj. Hence
all readings of the barometer must be reduced to what they would be at one nniform
temperature, that of 32° Fahr., when the specific sravity becomes 13*60. The bnsi
scale by which the height is measured also expands l^ heat, and is only of theitandaid
length when at a temperature of 62° F. (for tne English yard).

To ascertain the temperature of the barometer, a thermometer is always attached.
This should be placed half way up the barometer tube, with the bulb dose to thetnbe,
and well covered up from the atmosphere. The barometer should be placed io a
room of which the temperature changes as little and as slowly as possible.

If A be the observed height of the barometer, and t its temperature in degrees Fahr^
the height reduced to 32° F. is

._. '0001001(^~32)~'000010434(<-62)
1 + -0001001(^-32)

but it is quite exact enough to subtract (or add if < bo less than 29° Fahr.) the fol-
lowing correction :

hUt- 32)(-0001) - (i- 62)(-00001) I

The reader wiU observe that the cubiCf not the linear, expansion of mercuiy is nsed
in these formulae, for it is on the cubic expansion that the specific gravity depends.

The correction is most conveniently obtained, however, from a table such as that
on the following page, which applies to barometers with hrast scales, extending fiom
the cistern to the top of the mercurial column.

BAROMETER.

513

Tails for the Temperahire-^sorreetUm of the Barometer.

IVap.

a
ss

41
4S

43
44
49

46
47

S8'6
Ineh.

•008

•009
•013
■014
-017
•019

-cn

•034

Inch.

»
36

•7

-oo

•033
-034
•017
-040
•043
-046
•047
•050
<03f
•086

•057
•060

-007
•C09
-013
•014
•057
-O90
-€S3
-035
-037
•CSO

-OSS
-O40
-4M8
-046

-4M8
•051

Inch.

sao

Inch.

•065

•070
•073
•075
•078
•000

-066

-€68

-061
-064
•066
•060
•071
•074
•077
•079

-Ofa

•007
•009

•013
•015
•017
•030
•033
•025
•038
-030

■on

•036
•088
•041
•044
•046
•049
•053
-064
•067

•089
•068
•065
D67
•070
•078
•075
•078
•080
•088

•007
•009
•013
•015
«I8
•090
•028
•026
•088
•081

•084
•086
■080
-043
•044
•047
•060
•053
•055
•058

•060
•068
•066
•068
•071
•074
•076
■079
•083
•085

80-5
Inch.

•007
■010
■013
•015
•018
■081
•023
-026
•039
•081

•034

•087
•040
•043
•045
•048
•051
•053
•066
•069

•061
•064
•067
•070

•or2

•075
•078
■081
•088
■086

Temp.
OF.

61
69

68
64
65
66
67
68
68
70

71
73
73
74
75
76
77
78
79
80

81
83
83

85
86
87
88
89
90

38-5 I 29-0
loch. I Inch.

•083
•085
•068
•090
•098
•096
■008
•101
•103
•106

•108
•III
•118
•116
•118
•131
•183
•126
•138
■181

•184
•136
•139
•141
•144
•146
'149
•151
■IM
•156

•084
•087
•089
•098
•096
•097
■100
•103
■106
•106

•110

•113

•115

•118

•130

•123

•196

•128

•131

•188

•186
•138
•141
■144
•146
•149
•161
•154
•156
'159

29-5
inch.

•086
•088
•091
•094
•096
•099
•109
•104
•107
•109

•113
•116
•117
•130
•123
•133
•128
•130
•188
•186

•188
■141
•148
•146
•149
•161
•164
•157
■159
■162

30^0
Inch.

■087
■090
•093
•096
•098
•101
•103
■106
■109
■111

30-5
inch.

•089
•091
•094
•097
•100
•102
•106
•108

•no

•113

•141
•143
•146
•149
•161
•164
■157
•159
■162
-164

'114

•116

■117

•119

'119

•131

•122

.134

126

•127

•129

130

•132

183

•135

135

•137

138

•140

•143
•146
•148
•161
•164
•156
•159
■162
•166
•167

Aftron. Kaeh. t, iiX ^ w* «*« ^^ ^

Sodetj on Physics," 1840. The Admirally "Manual of Sdentific Enquiiyv""and most
woAb on Fh jdcs and Meteorology, also contain tables, often slightly differing fiom
each other. •

To obtain an appraximate correction, mnltiply the number of inches in the height of
the reading by the number of degrees Fahr. above 32**, and subtract -0001 inch for
every onit of me zesnlt. The following data are usefuL

^Coefficient of the cubic expansion of

For lo Fahr.

}•

0001001

(log. 1-0001001 » 00000485)

Coefficient of the linear ^^^^P^^o^I.qqqqqqkq
of brass y

Coefficient of the linear expansion) .aaaaiac
ofbtass adopted by Schumacher { <^«'<^i06

Coefficient of the linear expansion) .aaa/)^4o
of glaae* \

For 1° Centigrade.
•00018018

•00001722

"OOOOISS

*0000086

The last most be employed instead of the coefficient of brass, when the scale is
engraved on the glass barometer tube, as often occurs on the Continent. Tables for
glass mefare s^es and centigrade degrees, will be found in Bunsen's Gasometry
translated by Koscoe. ^*

Thb CiLFOxABT D»BB68ioK of the morcurial column is a formidable obstacle to the
attainment of accuracy when the tube is of small bore. For this reason, important
rtandaxd bazometers, like that of Kew^ have a large tube in which the capillary de-
prawon is ini^ipredable.

The eatiee of the depression is, that the particles of the merctriy have a much
stronger attraction for each other than for the glass ; a slight resultant attraction thus
arises, tending to draw each particle towards the general mass of mercury. The form
which the mariace of the mercury assumes is spheroidal ; the highest point of the
smfiMe is to be always taken, in adjusting the edge of the vernier for an observation.

To avoid any error from the capillaiy depression, it is far the best way to compare the
barometer witli an undoubted standard barometer in which the capillary depression is
iamredable. The eonection for capilkritv is then merged into that for index eivor.

514

BAROMETER.

If this be not done, the bore of the huometer tube roust be aKertained from the
barometer maker, or otherwise, and the correction then taken ftom the following table,
which is the one generally adc^ed for the puipose in England.

Diameter
of tube.

Add to the reading for

Dieiseter
of tube.

Add to the reeding fsr

UsboUrd tobet.

Dolled tubet.

Unboiled tnfaee. Boiled tobet.

0*60 inch.
0*60 ,.
0*46 „
0*40 „
0-36 „

0*004 inch.
0*007 „
0*010 „
0014 „
0-020 „

0.002 inch.
0*008 „
0*006 „
0-007 „
0-010 „

0*30 inch.
0*26 „
0-20 „
0*16 „
010 „

0028 inch.
0*040 „
0060 „
0*088 „
0*142 „

0*014 inch
0*020 „
0*029 „
0-044 „
0*070 „

Gontinental obeervers haTe attempted to attain greater aocnia^ hj ™«^"g the
hei^t of the meniBcns or carved snimce of the meicarj an argument in the eocrectioiL
M. Delcroa has calculated an elaborate table on this pnnciple of wfaidi a pait is hoe
given.

Bore of the tube.
MiUimetree.

Height of the menltcui in mflttmetree.

0-2

0-4

0*6

0-8

1-0

1*2

1*4

1-6

1*8

30
4-0
60
60
7 0

0*24
0-12
007
0-02
001

0-48
0*24
018
006
003

0*70
0*36
019
009
0-06

0*90
0-46
0-26
0-13
009

107
0-66
0-30
018
0-10

1*20
0*63
0*36
0*20
0-12

1*32
0-71
0-40
0-23
014

0*77
0*44
0-26
016

0-27
016

For the full tables and for a veiy elaborate description of the principal staodard
barometers on the continent, the determination of their mean differences, and the
errors to which barometers are subject, the reader should consult a paper by BraTais
and Hartius in Nouy. M^m. de TAcad* Boy. de Bruxelles zir. 81 (1841); see also
Dove, Repertorium dcr Physik, L 87. ^

The capillanr depression of the barometric column has been investigated mathe-
matically by mr. Ivory in the Philosophical Magazine and Annals for 1828, toL iii.
p. 1. [This reference is usually wrongly given to the Philosophical TransactioDfl.]

This correction is considered unnecessary to the Gay-Lussac, or any other syphon
barometer, in which the two surfaces of mercury are of equal extent, and therefore
subject to equal eapillaiy action. But we think that the aohesion of the merany ia
the lower limb of the Gay-Lussao tube, being much increased by the presence of air
and dust, is liable to cause inaccuracy unless carefully attended to.

The Indbx Ebbob is properly the error in the length of brass rod or scale ex-
tending between the two surfaces of mercury. Such error may usually be considered
uniform for idl parts of the divided scale) which is accurately divided b^ a madiine,
and tiie error probably arises, if at all, from the wrong acyustment of the ivocy fidodal

But the index error, as usually determined by comparison with a standard barometer,
comprises the capillary depression before mentioned, as well as any ininut« errors &om
impurity in the mercury, from imperfect vacuum in the upper part of the tube, error
of the attached thermometer, and so on. Comparison with a standard, in short, secures
the final accuracy of the result^ and no observer of the present day who desires to be
considered trustworthy should use an uncompared barometer. The purchase of a
barometer for scientific purposes should insist on receiving with it an authentic certi-
ficate of its index error from comparison with the Greenwich, Kew, or Boyal Society
Standard. The best barometer makers, Kegretti and Zambra, Newman of Begjeut
Street) or Baitow of Oxenden Street, the latter the maker to the British MeteoroJo^cal
Society, will readily procure such a certificate. Of course a fresh connpariwon is neees-
sary if the barometer be in any way disordered or suspected of being disordered.

To compare two barometers, they should be suspended side by side, and a score of
simultaneous readings of each taken at intervals, if possible when the barometric
column is at various heights, and both rising and falling. The reading of eadi baio-
meter are to be fully and carefully corrected for temperature, according to its own

BAROMETER. 515

attached thermometer ; the mean difference of all the readings, together with the known
index errar of the one barometeTf is the index error of the other barometer.

From the imifiirmity of the i^eadinga, the observer may judge either of his own skill or
of the ehaiacter of the instruments. With good instruments and a careful observer, the
differences should be uniform within about ^ of an inch, and the whole index error,
apart from capillary action, should^ not exceed ^ or ^ ; thus, in the comparison of
the writei's barometer bj Mr. Glaisher at Greenwich, tne differences of twenty read-
ings Tazy fitmi —0*009 to — 0'020, with a mean error of —0*014, apart from the
assumed capilkiy depression '008 inch, making the whole correction + *022 inch.

Treated according to the formulae of the calculus of probabilities, the probable error
of this determination from the mean of twenty observations is rather less than *0015
inch. Assuming the Greenwich standard to be absolutely correct, this probable error
of "0016 inch is the only source of error which would not be elimmated by a proper
use of the instrument, and in the taking oi a number of observations, as is always the
case in meteorology.

It is curious that a barometer maker, named Assier-Perricat, of Paris, as long ago as
1808, fffsetised and advocated the method of ensuring the accuracy of barometers by
comparison. (Assier^Perricat, Nouveau Traits sur 1 Invention des Barometres, etc.)

It is important to be able easily to detect the presence of any air which might by
aecident g^ into the upper part of the barometer tube, where it would falsify the reading
by a minute direct pressure, and probably also by increasing the capillary action. There
happens to be a ready and perfect test as follows : — ^Incline the barometer so that the
meieuzy may run up and steike the sealed end of the tube ; if the sound be sharp and
metallic, repeat the experiment several times, each time more gently. If the least
trace of air be present, the sound will at last become soft and pufiy ; it, on the con-
trary, the vacuum be perfect, the sound will always remain beautifully clear and
distinct]^ metallic.

If air he thus detected, uncover and examine the end of the tube, to see how large
a babble remains when the barometer is laid flat. Also invert the instrument and tap
it, as shanly as is safe, near the bubble, which may sometimes be thus dislodged and
eliminatea, . We do not think that a minute quantity of air can sensibly affect the
reading of the barometer for ordinaiy purposes, but if there be more, the instrument
must certainly be disused until refilled by the maker. If important observations have
been made with a barometer containing air, they mav be corrected, if the barometer be
compared with a true one before its condition is altered. The simple difference of
leadingB will be an approximate correction, but the exact correction is

«i(*-*i) + «9(*a-*)

in which e^ and e^ are the errors of the readings ^ and A, at different points of the
scale, as determined bv comparison, and h is the reading to be corrected.

If we suppose a bubble of air of ^ of an inch diameter a^ the atmospheric pressure
to enter the vacuous space of the Fortin barometer, described above, the depressing
cflfect on the mercurial column may, by a simple calculation, be shown not to exceed
Tsfg^ of an inch, apart, however, from any influence on the capillarity, a point probably
of moch greater importance than the direct effect.

DiSBonoHS fOB TAxnfO AN Observation o9 the BAfioMSTfin.

1. Bead and record the attached thermometer, making a correction for index error
if necessary (see Thbbmombtbb).

2. Adjust the mercury below to exact contact with the flducial point.

8. Slightly tap the tube near the upper end of the column, and adjust the edge of
the vernier to exact tangential contact, the line of vision being horizontal.

4. Becord the reading and work out the correct height as soon as conyenient after-
wards, as ahown in the following example, which comprises all i^e corrections ever
required: —

Inches.

Attached thermometer . . 58*3 F. Barometer reading < < 29*964

JkOa, Keutral point . . 28-861 Gntection for capacity • + *033

Capacity . . . ^ « n capillarity +'007

Diameter of the tube . *4 inch

Index error to K. 0. 4«^.,v«n«*»*«- .nan

8t«.d«i (.1^ from _ " '. :?pf«ir :.o?2

caj^llarity) • — '014 inch

LL 2

80-004

-•080

index error —-014

True height of the barometer 29*910

ft It

516

BAROMETER.

When many observatiomi of one barometer hare to be made, much labour irin be
saved bj combining all theee corrections into a special table, one refereace to Yhich
furnishes the required correction. In important obserrations or oompaiisoDS, the ad-
justments and Temier readings should be made with a pocket lens.

It is much to be desired that the English should adopt the metre scale for the baro-
meter, which is used all over the Continent; bnt although this may at onee be done in
chemical matters, it seems almost impossible at present in meteorology. For the mgj
reduction of the barometer scale from millimetres into English inches and vice ffcna,
we giye the following tables. Negretti's portable barometer may be had'wilh both
millimetre and inch scales attached.

Milll-
ineCrct.

Inches.

Milli-
metrei.

Inches.

Mim-
metree.

Inrfaft.

700

27-660

761

29-667

762

30-000

706

27-766

762

29-607

763

30-040

710

27-963

763

29-646

764

80079

716

28-160

764

29-686

766

30-119

720

28-347

766

29-726

766

30158

726

28-644

766

29-764

767

30197

730

28-741

767

29-804

768

30-287

736

28-938

768

29-843

769

30-276

740

29134

769

29-882

770

30-315

746

29-331

760

29-922

771

30-355

760

29-628

761

29-961

772

30-384

1 millimetro - 0*03937 inch 1 inch » 26-39964 millimetres
0-1 „ » 0*00394 „ 0-1 „ - 2-/)d996 „

0-01 „ » 0*00039 „ 0-01 „ - 0-26400 „

0-001 „ » 0-O2540 „

Uses of tsb Babombtbb.— The chemist requires to know the atmo^beric ^m-
sure when very accurate weighings are made of light bodies, in order that the weight
of the air they displace may be idlowed for. On this subject^ see Bessel's ibnnils in
the article Spbcifio Gbayitt. Secondly, gases are usually weighed or measured, sab-
ject to the atmospheric pressure, and vary directly in densiiv and invendy ta vchmn
with the pressure. Hence the atmospheric pressure must always be obserred at the
moment, m order that the weight or measure may be reduced, by a simple caleolatioD, to
what it would be at some standard pressure, which in England is 30*000 inches^ and

on the Continent 760 millimetres or 29*922 inches. Now ^^Iqoo k 100 « 100i61

or 100 cubic inches of gas ^t the Englisli standard pressure are equal to 100*261 enbie

inches at the French standard pressure. It happens, howeyer, that the Eng^ adoft

60^ F. and the French 32^ F., as the standard temperatures in these matters, and

allowing for the expansion of mercury between these points, 29*922 inches \xffim

30*006. Hence the true equivalent volume on the continental standard for 100 cnhie

30*000
inches of gas at 30*000 inch, 60<> F., is ^-^ x 100 - 99*98 cubic indies, the difRv-

ence being so trifling that it may almost always be neglected.

DBTBSiaNi.Tioir OF A1.TITUDBS. — Since the barometer measures the weight of the
8uperincwmbeni air, the higher we rise in the atmosphere the lower the barometer mast
stand. At the sur^Ace of the earth, the barometer changes nearly *001 inch for ereij
foot in the change of altitude ; but more exactly, the change of elevation corre^poDd-
ing to -001 inch of the barometer, is : —

At temperature of ZQP 0*866 foot

„ 40«> 0-883 „

ss », 60° . . . . . 0-900 „

. ,> „ „ 6OO 0-918 „

M s, ,.700. . . .. . 0-986 „

„ 8OO . . . . . 0*964 „

The difference of level ( a « feet) of two barometers mi^r be calculated by the foUov-
ing formula :

* = 60346-7 X \ 1 + 0002837 cos 2 lat. | x |l + ^-^\ ^ogf

BAROMETER— BARYTIC FLUORSPAR. 617

in vlxich B and b are the simaltaneous corrected heights of the barometers at the
higher and lower stations, and T, t the numbers of decrees Fahr. above 32^, at which
the thermometen stand. (Biot^ Traits de Physique, 1. 100.)

If the heu;ht does not much exceed 8000 feeti the following more simple formula
maj boused:

X « 62494-3 X ^^ x ^ * ^ '*'

In meteorological observations, it is necessaxy to know the height of the barometer
above the mean sea level, and to reduce the average results to that level accordingly, in
ofdtT that they may be comparable witfi observations made at other places, and reduced
in a similar manner.

HxXBOBOLOOT. — The chief use of the barometer is of course in meteorology, since
changes of pressure in the atmosphere are the immediate cause of all winds. These
changes are extremely complicate and interesting : for besides the irregular fluctua-
tions, and extraordinary disturbances during storms, there is an average chanee, ac>
cording to the season, and a semidiurnal oscillation, probably due to a kmd of
atmospheric tide, caused by the expansion of the atmosphere, where it is heat«d bv
the son's rays (Phil. Mag: [4] xviL 313). In keeping a register of the barometer, it
Ehonid be observed every day at 9 ▲. x., the time of the daily maxim nm, and at 3 p.m.,
the time of daily minimum, or eUie at noon, when the pressure is near the mean.

The nightly maximum is about 9 p.ic, the nightly mininnm about 4 A.1C. Almost
eveiy climate, however, is characterised by special laws of barometric fluctuation.

Ajoboid Babomxtbb. (a, priv. yfipos, liquid).— The essential part of this beautiful
inetnunent is a small round metal box, eidiausted of air, and with a thin circuhurly
flated lid, which the weight of the atmosphere more or less tends to press in. A
complicated system of levers, causes an index, revolving over a dial, to mark the
slightest movements of this metal lid. (Vidi, Compt. lend. xxiv. 275; BelviUe's
Manual of the Mercurial and Aneroid Barometers.)

Boitsdor's Mbtaluc Babombtbb also consists of a vacuous metal box, but it is in
the ibrm of a flat tabe bent almost into a circle. The two ends of the tube approach
or recede as the atmospheric pressure increases or diminishes.

These metallic barometers are veiy sensitive and excellent as weather glasses, and
thej should be carried at sea or on exploring expeditions as a last resource in case the
mereorial barometers, as often happens, become disordered. But they afford no inde<
pendent measure of pressure, and are so much affected by variations of temperature as
to be unsuitable for scientific use. The writer, however, has used an aneroid baro-
meter with some success, and obtained an approximate correction for temperature by
sbnply warming the instrument on various occasions, and noting the average change
of reading (» -0065 inch per degree F.) thus caused. An adjusting screw will be
found at the back of the aneroid barometer, by which its reading may be made to
agree at some one point and temperature with that of a mercurial barometer.

For a description of Macworth*s '* Underground barometer," see Ur^s Dietionary
of ArU, Mamtfacturts, and Mtnea, i 255.) W. S. J.

The resinous incrustation in the wounds made in fir-trees.

A silicate of calcium and aluminium found near the river Bar-
sowka in the Ural, in compact white masses eft fine-grained aggregations, having a
distinct cleavage in one direction. The granular variety has a faint mother-of-pearl
lustre : the compact variety is dull and trtmslucent on the edges. 8p. gr. 2740 to
2-7 51. Hardness 6'6 to 6*0. Before tiie blowpipe, it melts with difficulty to a tume-
fied giUss on the edges : with borax, slowly and quietly to a transparent colourless
glass; Hkewise with phosphoms-salt, with s^aration of silica^ the glass becoming
opalescent on cooling if the proportion of the mineral is considerable. With an equal
veight of carbonate of sodium, it melts to a tumefied glass, which with a larger
quantity of soda, becomes snow-white and infusible. With solution of cobalt, it
becomes blue on ignition. The powder is easily decomposed by hydrochloric acid,
forming a thick jelly. According to Varren trapp's analysis, it contains 3(2Ca'0.8iO*).
(4AlK)'.3SiO') a small quantitiy of the lime being replaced by magnesia. (Handw.
d. Cfa«m. 2** Aufl.iL 679.)

SJLVWDOB or C AMWOOB. A red dye-wood, the colouring matter of which
appears to be identical with santolin (Preisser und Girardin, Ann. Ch. Pharm. lii.
376.) See also Ur^s Dictionary of Arts, Manufactures and Mines, i. 255.)

See Babtttk, Oxides of.

or BaJlOSBUBVZTB. See Hravt Spar.
;IT1C FXiVOBSPiUL A mixture of about equal parts of sulphate of barium

L L 3

5 18 B ARYTO-CALCITE — BASALT.

and fluorspar, occurring on the slaty limestone of Derbyshire^ wheze it forms a bed
about an inch thick.

BaCaCO*or BaO.CC^ + CaO.CCP; a ninetal fbnikd ii
Cumberland, of a slightly yellowiah-brovn tinge, translnoent^ with a vazy histoe, sad
sp. gr. 3*66. It contains cavities which are lined with ciystals haying the form of oblkns
rhombic prisms. The external surface is coated with sulphate of barium. (Brooke,
Ann. PhiL N.S. viii. 114.)

The name baiyto-calcite was also given by Thomson to a laminated mmenl mb-
taining 71*9 p. c. sulphate of barium and 28*1 sulphate of calcium, found betwMu
Leeds and Harrogate in Yorkshire ; also by Joi4insto n to Alstonite, which is <tf the
same composition but different crystalline form.

BASTTO-OCBUHiTZV. This name is given to two minerals^ both oonsialiii^
of sulphate of barium and sulphate of strontium (ccelestin), one occurring near Kisgi*
town in Canada, the other in the Binnenthal in Switzerland. The Swiss minenlfnms
orthorhombic crystals, containing, acoordinff to Waltershansen (Fogg. AmLzdr.
134), 87*8 p.c. sulphate of barium and 9*1 sulphate of strontium. The Canadiaa mine-
ral occurs in crystalline masses, containing, according to Thomson, Ba^.SSO*.
Allied to this is a mineral from the chalk mail of Moen, containing 40 p.e: Si^SO^i
28-3 Ba'SO*, 16-5 Ca«SO*, 13-6 Ca«CO«, and 26 water.

kTTOVBTKURnk Syn. with Crlobitoids.

A rock of volcanic origin, occorrinff in amorphous masses; eolnnuttr,
amygdaloidal, and vesicular. Its colours are greyish-black, ash-grey, and raveo-bladL
Massive, with dull lustre and granular structure. FHctare uneven or eonehoiiU.
Concretions columnar, globular, or tabular. It is opaqne, yields to the knife, bnt ii
not easily frangible. Streak light ash-grey. Sp. gr. 3. Melts into a black glssB asd
recovers ita granular structure by slow cooling. It is found in beds and tods m
granite and mica slate, the old red sandstone, and coal formations. It il distri-
buted over the whole world, and is met with in great variety in Scotland.

The most remarkable variety of basalt is Uie columnar, whidi foims immoifa
masses, composed of columns thirty, forty, or more feet in height^ and of enonpon
thickness ; those at Fairhead are two hundred and fifty feet high. These oonstitiite
some of the most astonishing scenes in nature, for the immensity and regokritj of
their parts. The coast of Antrim in Ireland, for the space of three mOes in kogtlii
exhibits a very magnificent variety of columnar difb ; and the Giantfs Gansevay
consists of a point of that coast formed of similar columns, and projecting into the sea
upon a descent for several hundred feet These columns are^ for the most part,
hexagonal, and fit very accurately together; but most frequently do not adhen
together, though water cannot penetrate between them. Another very remaikaUe
formation of columnar basalt is the i^and of StajQb on the west coast cl SMtiand.
The most extensive mass of basalt yet observed is that disoovered by Cokmel 9jkm
in the Deccan, where it occupies a suiliAce of many thousand square miles.

Basalt is not a mineral of definite constitution, but a mixtine of several minoih,
generally of labradorite, augite, olivine, magnetic iron ore, and a leolite. ^ 'Hieie
minerals may however be repuu^ed by others, namely labradorite by other TVstAua d
felspar, and augite by amphibole : the zeolitic portion also varies greatly in compo-
sition. Some of the constituents of basalt viz. tibe olivine, the magnetic iron ore and
the zeolite are decomposible by hydnSchloric or sulphuric acid ; the rest fbr the mort
part resist the action of acids; but the analytical results obtained by tins mode «
treatment are not veiy definite, inasmuch as the action of the add varies vith its
Htren^h, with the state of aggregation of the basalt, and with the natere of die
individual minerals of which it is composed. The constituents of basalt, are alia
(about 50 per cent) alumina, protoxide of iron, Ume, magnesia^ potash, soda and
water, the proportions of which differ considerably in the several varieties of hamit,
as shown by the numerous analyses which have been made of it

Basalt when calcined and pulverised, is said to be a good substitnte fbr posolasa
in the composition of mortar, giving it the property of hardening under water. Wine
bottles have likewise been manufactured with it, but there appears to be some nieety
required in the management to ensure success. A mixture of 1 pt basalt, 2p^
broken glass, 2 soda, 1 wood-ash, and ^ peroxide of manganese, has also been used
for similar purposes.

BABATaTIO BOmWBUnrBB usually occurs in opaque six-sided eiyita]s,vlidi
sometimes act on the magnetic needle. It is imbeaded in basalt or P*"*^*^
Colour velvet-black. Lustre vitreous. Scratches glass. Melts with difficidtytoaWack
glass. Contains 47 per cent silica, 26 alumina, 8 lime, 2 magnesia) 16 iron, and 0*9

BASANITE— BASTITE. 519

water. It is found in the basalt of Aithni^B S6at> in that of Fifeshire, and in the Isles
of Mull, Cannai Eigg, and Skye ; also in the basaltic and floetz traps of England,
Inland, Saxony, Bohemia, Sileeia, Bararia, Hungary, Spain, Italy, and France. U.

See Jasfhb. — migAirollMiAWmi See Ilmenitb.

This term ia the correlatire of Acid, and denotes the electropositiTe oonsti-
toent of a salt. Its signification yaries, howoTer, to a certain extent, aecordins to the
Tiew whidi is taken of the constitution of salts. In the dualistic system, which re-
gards salts as formed by the union of two binary compounds of the first order, e,g,
sulphate of copper « On*O.SO': sulpharsenate of potassium « SK*S.As^*: hydro-
chlorate of ammonia -> NH>.HC1 ; nitrate of ethylamine » NH*(C*H*).HNO*, &c ;
the base is the electropositiTe oxide, sulphide, selenide, or alkaloid, which unites with
the eleetronegatiye oxide, sulphide, &c., or hydracid ; but in the unitaiy system, in
whicii the salts of any acid are regarded as formed on the same type as the acid (or
hydrc^gen-ealt) itself the base must be understood as the metal or other electropositive
ntdide by wliich the hydrogen of the acid is replaced : thus in the salts aboTe-men-
tioned, zegazded as Cu^80«, £>AsS«, NH«C1, NB>(C*H*).KO', the bases are the ladides
Ca,-K, 17H*, KH*(CPH^). (See At.kat.ts, Alkaloids, Axikbs, Aioiokiux-basbs,
OsDss, Badiclbs.)

See Htdbocsbitb.

The power of an add to unite with one or more atoms of base. See
AfTDS, p^ 46.

SASZ&lOUMff OI& oaP« The leaves of the Ocymwn basUieumf a plant belong-
ing to the labiate order, field by distillation with water, an essential oil, which after
a while deposits OTJsmatic crystals, having the character and composition of hydrate
of taipentme, CP*H:xO*«C"H>«.3HH) (Dumas and P^ligot). The oil itself has not
been i*yaTnif^afl,

'MIf lli XJLTiyOSUL* The seeds of this plant, which grows on the Hima-
layas, yield by pressure a yellowish oil, which gradually becomes colourless on expo-
snre to light, has a faint odoTir, a density of 0'958, and a buttenr consistence at
ordinary temperatures ; melts at 27^ to 30^ C. ; dissolves sparing]^ in anhydrous
alcohol, scarcely at all in spirit of ordinary strength, readily in ether. By saponifica-
tion it yields, besides oleic acid and glycerin, two fatty adds, one which has not been
obtained pure, but appears to have the composition C'*H'*0'; the other, originally
supposed to be a pecuhar add, and called bamc acid, is identical in composition and
properties with stearic add, C'*H'H)'. (Hardwicke, Chem. Soc. Qu. J. ii. 231.)

MMkMM/OfBXMm The prindpal constituent of Gumrni beuaora, G. Ihritonerue, or
G. KuUrOf a gum obtained from various spedee of acada. This gum contains only
abofot 6'6 per cent of matter soluble in water (arabin), while the larger proportion,
which IB the bassorin, merely swells up in water. (See Quic)

MJkBVAMD C&OWB. Drtfolium hyhridum. — 100 pts. of the fresh fiowering
plant yield 2-44 pts. of ash ; 100 pts. of the dry plant 8*1 pts. of ash. The ash con-
tains in 100 pts. 19-9 potash, 5*7 soda, 18*4 lime, 3-1 msj^esia, 5*6 alumina (?), 3'9
aesquioxide of iron, 1*8 protoxide of manganese (?), 35*1 silica, 1*4 sulphuric anhydride,
4-6 phosphoiie anhydride, 0*6 chlorine. (Sprengel, J. pr. Chem. x. 56.)

BJIAVm. A mineral found at Basti in the Hans, and forming imperfectly
defined individual crystals inteigrown with serpentine. It deaves very easily in one
direetioD, less easily in another, maldn^ an an^e of 87° with the first ; there are also
two imp^ect deavage-planes in the direction of the longitudinal and lateral faces.
Fractare, uneven and splintery. Colour, leek to olive green, passing into yellow and
brown. It has a metallic, glittering, nacreous lustre on the deavage-faoes ; translucent
on the edges. Spedfic gravity 2*6 to 2*8. Hardness 3*5 to 4*0. Qives off water when
heated, and before the blowpipe becomes pinchbeck-brown and magnetic; it then
splinters^ mdting to a brown glass on the edges. With borax and phosphorus-salt,
it ^Tes the reactions of iron and chromium, and with the latter a skeleton of silica.
It 18 imperfectly decomposed by hydrochloric, completely by sulphuric add. Its
composition is nearly represented by the formula 4Mg*H*0' . 3(Mg^ or Fe*)Si*0*
which, if the hydrogen be regarded as bade, may be reduced to the general form
IP^i'O**, that is to say to the formula of an. orthodlicate ]k[^SiO\ Hermann
regards the mineral as crystallised serpentine somewhat altered in compodtion by ad-
mzxtnre of foreign minerals ; but its form indicates rather a relation to the augite
fiunily. (Handw. d. Chem. i 756.)

SA8T&. GhTiham's name for the metal or other electropodtive constituent of a
•alt (Elements of Chemistiy, 2nd ed. i. 186).

LL 4

620

BATATAS— BATH.

Sometimes called ContiolviUui bataiaa er Spamik
potato, a plant said to be indigenoiu in Indian bnt extensively cultivated in AnuriM,
and sometimes also in the south of Europe. The tubers resemble those of the podtOb
but have a sweeter taste. According to T. J. Herapath (ChenL Soe. Qi. J. iii.
194), they contain, in the fresh state, 66'7 per cent water and other vdlstUe mitto',
31*8 vegetable matter, and 1*5 inorganic matter. The ash contains in 100 pli.: —

(a.) Soluble in water, -^^1 CO*, 71 S0«, Oi) i»0», 29*3 KX), 12^ KCl, and IW
Naa

{h.) ItuolubU. — 6-2 C0«, 7-1 P'O*. 120 CaK), 1-4 MgK), 1-3 Fe*0», 21 SiO», ^th
traces of sulphuric acid and alumina.

According to Henry (J. Pharm. xL 223) the tubers contain in 100 pts. 13*3 itazdi,
0*9 albumin, 3*3 sugar, 1*1 fit insoluble in ether, 6*8 woody fibre, 1*4 malie add, acid
phosphates, chloride of potassium, &c, and 73*1 water, also (H)$ of a volatile poieoiioti
matter.

The heat communicated from lamps and fixes is subject to variation frm
many circumstances ; and this variation not only influences tb^e results of opentioii^
but often eiJdangers the vessels, especially if they are made of glass. To obTiate thcie
sudden changes of temperature, and at the same time to affi>rd means of obeerring and
regulating the degree of heat imparted, the vessel containing the substance <^>ented
upon is immersed in another containing water, oil, fusible metal, air, or other medinni,
whidi receives the heat directly from we source. The sand-bath and water-bath are
most commonly used, the latter for maintaining a substance for any length of time at
the constant temperature of 100° C, the former for higher temperatures, paitJcnlariy
when the exact observation of the temperature is not an object. In usin^ the watv*
bath, the vessel to be heated may, according to convenience, be either immetsed is
the water or so placed above the vessel that its lower surfiice may be in oontaeC vidi
the steam. A ready method of constructing a water-bath for small operationa ia ta
place the basin containing the substance to he heated on the top of another of eqpl
size, containing water and supported over a gas lamp.

The temperature of the water-bath may be raised above 100^ C, by diaaolTing oertain
salts iu the water. A saturated solution of common salt boils at a temperatore of 7^*6 C.
or 13° 3 F., above the boiling point of water ; and by using a solution of ehloride of
calcium, a bath of any temperature between 100° and 125° G. or 212° and UV^f.
may be convenientlj[ obtained.

Liquid baths of higher temperature are obtained by the use of linseed oil or foaibla
metal heated in cast-iron pots. The oil-bath may be used for temperatoree nn to abost
300° C, but it is dirty, and exhales an extremely unpleasant odour when strDngly heated
Fusible metal is much cleaner and more pleasant to use, but its weight is an ineoa*

i^. 94.

Fiff.96,

venienoe where a large bath is required. A thermometer immersed in the lifoid, tf
near the middle as possible, serves to indicate the temperature. The oil-bath is moeh
used in the determination of vapour-densities by Dumas's method, also for heatiiig
volatile substances or mixtures in sealed tubes, so as to sulject them to a higfasr Um-

BATH.

521

pentnre than th«t to which thej could be eicposed under the ordinaiy atmospheric
pteasnre. The danger of erploeion attending this operation may be obviated bj
enfiiUBiig the aealed gkas tabe in a strong tube of wrought iron, haying a massiye
screw cap.

The air-bath is yeiy conyenient for many purposes, especially for desiccation. An
aii^bath may be extempoianeonsly constmcted by placing an empty basin oyer a lamp,
and another basin containing the sabstance to be dried on the top of it. The upper
yeasel ia tiien heated by the air in the interyening specc. A more conyenient apparatus,
which also eerves to indicate the temperature^ consists of a cylindrical copper yessel ▲,
fa, 94, the coyer of which is moyable and has two apertures, the middle serving for
the eeo^w of vapour and the lateral one for the insertion of tiie thermometer. The
vessel to be heated rests on a ring within the box, supported by a tripod. A larger
air-bath serving to heat several small vessels at once is represented in fig. 95. iOr-
baths are sometimes surrounded with a jacket to hold water or oiL When water is
used, tiie temperature of course cannot exceed 100^ C. When oil is used, the tempera*
ture is indicated by a thermometer having its bulb immersed in the li<]|uid.

Bigh-presawre batks. — The danger of explosion in heating volatile hquids in sealed
tubes is greatly diminished, when the tubes are at the same time subjected to an out-
ward presBore. This may be effected by endoeui^ the tube containing the volatile
lionid in a wider glass tube containing a less volatile liquid, and likewise sealed ; the
iraole ia then heated in an oil- or air-bath. In this manner, alcohol or ether may be

Fig. 97.

Fig, 96.

heated to 360® C, the outer tube containing oil of turpentine (Berthelot). Greater
aecnrity is obtained by enclosing the glass tube in a wrought iron tube, with a
•cPBW-cap, or by the use of a Papin's digester, or better, by the following apparatus
invented by Frankland (Ann. Ch. Pharm. xcv. 30).

A A {fig, 96) is an iron cylinder 18J inches long, 3 inches internal diameter,
I inch thick in the side, and welded in one piece by the steam hammer. This cybnder

622 BATH-METAL— BAHLITE.

has a flanch, B B, 1} inch broad, { inch thidc, turned tnie on the upper sazfince, and
having an internal annulns sunk Xth of an inch below the lerel of the ranoonding ea^
fiace. The cap C C, which is of the same diameter and thicknese as the flandi/liM t
projecting face } inch deep which fits ezacUj into the mouth of the qrlindar. 'Vnthia this
projection the cap is pierced with two tapertireB, into one of which is fitted a csat-inn tabs
d, 6 inches long and } inch in external diameter, filled with meicoiy and deetbed to
receive a thermometer. The other aperture is bouched with brass, and serrei as the
bed of the safety-valve, which consists of brass wire | inch thick, somewhat flattened on
two sides, and furnished with a head accurately ground to the buzCekw of the cul The
valve is loaded in the usual way with a lever / and weight a. The cap ai»i flaneh
are fastened together by four screw-bolts, which are inserted m>m below andti^aed
by a lever-key, and the pressure thus exerted acts upon a lead wisher \ inch thkk,
placed in the annular depression of the fianch. In this manner the appaiatDs may be
made capable of bearing a pressure of 100 atmospheres without allowing any eie^
of gas. The cylinder A is about two-thirds filled with water, and the glass tobe eon-
taining the volatile liquid is enclosed in it. In this manner, tubes of oonaidarable vidth
may l^ heated without danger of explosion.

The apparatus is heated in a gajs-inmace ififf' 97). A A A A is a massiTe finme of
wrought-uon, within which is fixed a cylinder B B, of tin plate, closed at bottom and
open at top to receive the apparatus above described, e is a regulator for the admii-
sion of air. The gas-burner is a copper tube e, \ inch wide and pierced with 18 or
20 apertures. To prevent loss of neat by radiation, the whole appanttns is enclosed
in a cylinder B' B', of polished tin plate, separated from the inner cylinder hy a space
about I an inch wide. The products of combustion escape by the apertures D D.

BATH-MBTA&a An alloy of copper and zinc containing a laiger propoitioa
of zinc than ordinary brass, and usually prepared by melting brass with zinc;

BATSACKXTBi A mineral found on theBizomberp in the l^rrol, genemllymaahc,
with a granular structure, rarely crystalline. It oontams according to C. Bammels-
berg (Fogg. Ann. H i66), 37*69 silica^ 36*45 lime, 21-79 magnesia, 2*99 protoxide of
iron, and 1*27 water. Colour varying from liffht greenish-grey, like that of a frog
{fidTpaxos)t to white ; translucent wiSi waxy lustra. Specific gravity 3*0 to 3*1.
Hardness « 5*0. Melts before the blowpipe, assuming a pale red colour with sofaitioa
of cobalt ; is but slightly attacked by aads. The water appears to be nnessentiil,
and the composition of the mineral approaches to that of MonticeUite. (Handw. d. Chem.
ii. 767.)

BATAAOBOIiVXO ACIB. An acid said to be contained, togetiier with stetiic
acid, glycerin, and a peculiar yellow fat, in the oil obtained hj pressore from the
epiploon of the water salamander. (Bossignon, Compt. rend. xiii. 929.)

BAITDISSXSZTa. A dense variety of magnesite containing silica, found neir
Baudissero in Piedmont. As the amount of water contained in it is veiy Tsriable,
F. V. Eobell and Neumann regard it as a compact hydromagnesite intimatdy mixed
with silica.

.or Krablite. — ^A mineral found on the Erabla in ledand, and likewise

on theBaulabeic, either in short prismatic crystals belonging to the tridinic <ff doobly
oblique prismatic system, or in ciystallo-granular masses. Cleavage in two direetioDs
at right angles to each other. Fracture uneven and conchoidal ColourlesB, with
glassy lustre ; transparent or translucent Specific gravity 2*6 to 2*7. Hardness £i
to 6*0. In the following table, a is the analysis of a specimen of baulite resembling
pearlstone, from the Bamaberg, by Forchammer (Ann. Min. viii 644); h is that of
a ciystallo-granular variety of baulite, ejected by the volcano of Viti in Iceland, mixed
with quartz-crvstals and a black needle-shaped mineral, also by Forchhammer (Be^
zelius's Jahresb. xxiii. 261) : o is Genth's analysis (J. pr. Chem. IxvL 93), of emtal-
lised baulite from the Krabla :

SiO« A1«0« Fe<0« Fe«0 Mn«0» Ca*0 Mg*0 K«0 Na«0 CI, H«0

a, 74-38 13-78 1-94 1*19 0*86 0*68 2*63 3*67 0*12 2-08

6. 76*66 11*67 0*63 006 0*20 8*26 3*73

e, 80*23 11*34 trace 1-46 trace 4*92 2*26

These analyses agree sufficiently well with the formula (M«O.3SiO').(AlH)».6a0'),
which (if a/ - |A1) may be reduced to (M«fl/«)Si»0» or 2R*SiO«.7SiO«, the foimola
of an orthosilicate with \ at. silica; but it is probable, as Bunsen supposes, tiiattiie
mineral is intimately mixed with orthoclase, Before the blowpipe, bauHte is fhsibie
in very thin splinters ; with borax and phosphorus-salt it yields clear glasses, a dceleton
of silica floating in the latter. It is insoluble in hydrochloric acid. (Handw. d. CSicbi.
ii. 768.)

BAVALITE-BEAN.

523

SeeBABALTTB.

See SoDnnc, Chloridb of.

A gam-resin of which there are two yarieties, African and Iniian,
Afiieifcn bddHnm is deriyed, aooording to Perrotet^ from a shnib indigenous in Sene-
gambia, the HtnddUia afrioana (Guillem and Perr); BaUamadendron qfricanum
(Ajrnott); Amjfrh IHeattofU (Adanson), belonging to the amjredaceons order. It
forms irregular, translncent masses, of a yellowish, rMldish, or brownish colour, accord-
ing to age; uictoons to the touch, brittle, bnt soon softening, and erowins tough
between Uie fingers. I^>eeific ^^ifT 1*371. It has a bitterish taste, and a moderately
strong balsamic odour, not unlike that of myrrh. It does not easily take fire, and
when set on fire soon goes out : in burning it gives off a balsamic odour, and sputters
a little, owing to the presence of moisture, ^cohol dissolves about f of it, forming a
golden-y|sUow tincture, from which water throws down a yellowish-white resin, and
nitric acid a sulphur-yellow resin. Potash dissolves it completely. By dry distillation
it yields ammonia^ together with other products. According to Pelletier (Ann. Ch.
Phya. [2] \m, 38), it contains 59 per cent resin, 9*2 gum, 30*6 vegetable mucus, and
1'2 volalale oils (and loss).

Tlie resin is transparent^ bnt becomes white and opaque by boiling with water ;
melts between 68^ and 60^ C. According to Johnston (J. pr. Ghem. zxvi 145), it is
C**/P' O*. The cum is yellowish-grey, and when treated with nitric add, yields malic
but no mmac aei£ Theveg|etable mucus is also yellowish-grev, swells up with water,
coagulates with alcohol, and is converted by nitric acid into a thin liquid. The volatile
oil is heavier than water.

Indian bdellium is said to be obtained from BaUamodendron Mttkal (Hooker),
also an amyredaoeous tree, growing in Scinde. It forms iirognlar, greenish-brown, or
bladrish masses, having a strong c^ur, and sharp bitter taste like myixfa. It becomes
sticky between the fingers.

WMBMm Two species of bean ore commonly cultivated in Europe, via. 1. Faha
tmUgariBy or Vida Faba, the common field or garden bean (Fddbokne, groBse Bohne,
Smthaknt), the most common garden varieties of which are the Windsor broad bean,
^e Toker, the long-pod, and the Magagan, while for field cultivation, the Heligoland,
or tick-bean, and tne common horse-bean, are preferred as being more hudy. —
2. PhateoluM vulgaris^ the French, haricot, or kidney-bean, innumerable varieties of
which are cultivated, some dwarf, others climbing. The scarlet-runner, Phaseolus
muitijlarus is closely allied to this species.

The seeds of these several species and varieties differ but little in chemical com-
position, as the following tables will show; but they are all remarkable for the large
amount of nitrogenous matter (legumin) and phosphoric acid which they contain.

Tarlb A—

-Composition in

100 parts of

iHirious kinds of Bean.

1. Flddb-n itir-4rUdi

8. Hartoot-bean

4. ^ old Irtoh (— arlfrf)

C - coBnBonwhiU(Afr-

Lcmmla,

Sogar.

Own.

Starch.

Fat.

Pectin
lubitancei.

Woody
fibre.

Atb.

Water.

94*8
88-8
800
94-7
84-6

98-8

0-8
4<
6

4«5

4-0
6
'5

4'8

86-0
88-0
86^4
81*6

1-4
9-0
80
84
8-8

9-7

18
17
18

19*6
1(H>
•0

•8

8-fi
S'6
8-7
1-8

1-8
8-6

140
14-8
14-0
19-8
10-8

19*8

45*4

•9t

1. Poffgiale (J. Pharm. [8] zzx. 180). The shells amounted to 15 per cent of
the weij^t of the entire pods, and contained neither legumin nor starch. — 2. Mean of
earlier analyses by Braconnot, Horsford, and Erooker. — 3. Mean of earlier analyses by
Einhof, Boussingault, Horsford, and Krocker. ~ 4, 5. Poison (Chem. Gsje. 1855,
p. 211). — 6. Poggiale (loc, cit) The shells amounted to 7*5 per cent, of the weight
of the entire po£, contained very little starch, 0*2 per cent fat, 6'5 nitrogenous
matter, and 5*8 ash.

Ward and Eg gar (Jahresber. d. Chem. 1849, p. 708), obtained from several
Varieties of fresh beans grown on various soils : 2*4 to 3*6 per cent nitrog^en, 1*2 to
1'7 per cent fiit» and 1 1*0 to 17*0 per cent water. — Way and Ogston obtamed from
the same varieties of bean (Heligoland and Mazagan), grown on various soils, in
100 pta. of the fresh seeds : 8*1 to 17*0 per cent water, and in 1000 pts. of the dried
seeds of five varieties, 2*5 to 2*9 per cent sulphur, in a sixth kind, 4*6 per cent

anlpbnr.

• Cellolofe and SfaeUs. t Celluloae.

624

BEAN.

Mayer (Ann. Ch. Fharm. cL 144), obtained from 100 pts. of airbed Uuagan
beans, 11*8 to 12*5 per cent water, 1*18 and 1*18 phosphone anhydride, and 4*26 to
4*3 nitrogen. In dwarf haricot beans, he fonnd 10*1 per cent water, 1*06 phoB{ihorie
anhydride, and 3-32 nitrogen ; in climbing hazioot beanfl^ 9*4 per eent water, (^
phosphoric u^ydride, and 8*17 nitrogen.

The sugar occurring in beana is nsaally regarded as grape-sogar. Yohl (Aim. CL

Tablb B.— Cbmpont»on(inlOOptai)o/

I. Seed.
Faha vulgaris.

1. Common field bean from Holland

2. „ „ „ Alsace .
8. „ „ „ Gieesen
4. „ „ „ England
6. Maaagan bean (seed sown) . .

6. raised therefrom on clay soil

7. „ ti sandy soil

8. Heligoland i>ean (seed sown) . ^ .

9. raised therefrom on clay soil
10. H » sandy soil

PoUub,

Fha»echu vuigaria,

11. Haricot bean from Worms

12. „ „ Alsace . .
18. „ „ Knrhessen
14. „ „ England .

n. SnuLW.

15. CJommon field bean • • . .

16. „ „ . . . .

17. Mazagan bean on day soil

18. „ „ sandy soil .

19. Heligoland bean on day soil .

20. „ „ sandy soil

20*8
46*3
33*9
51*7
36*7
43*4
45*7
42*9
43*5
40*7

88*9
510
221
36*8

15-3
32*8
18*7
25-6
19*6
211

Soda,
Na<0.

Lhe«,
Ca«0.

17-8

13-0
0*5
01
1-3

1*6
2-4

11*3

21-4
18*4

13-8
2*8

13-9
41

0*2

39*3
19*8
18-9
22*4
18*3
25*6

7i
2(
3-1
47
4^
6-9

1. Analysed by Bichon (Handw. d. ChenL 2>«Anfl.ii.[2]59).— 2.BonsiiogaaU
{ibid,)-^Z. By Buchner (t^.)— 4-10 and 16-20. Way and Ogston (Jonnalor
the Boyal A^cnltoral Sodety, ix. pt 1). — 11. Levi (Handw.) — 12. BonsaingauU
(i^K^.)— 13. Thon (t^ti.)— 14. Richardson (Jahresber. d.Chem. 1847, 1848, pi 1075,
Tafd 0).~15. Hertwig (Handw.) This contained carbonic add, which has beea
deducted.

The pods of Phaseoliu muUifiorua contain, according to T. J. Her apath (Chan. Sot
Qu. J. 4), 94-1 percent water ; air-dried, they yielded 0*631 per cent, and, after diyiag
at 100^ C., 10*7 per cent, of ash, containing :«-

Of matter aolubU in water : 14*1 carbonic anhydride ; 3*4 sulphuric anhydride;
1*5 phosphoric anhydride; 36*1 potash; 4*9 chloride of sodium.

Of matter insoluble in water: 22*2 carbonate of caldum; 3*8 carbonate of mag-
nesium; 11*9 phosphate of caldum; and 2*1 silica.

BBAVMO Ji T AT Jk A mineral found in the gneiss at Jones Falk near Balti-
more, in North America, in square pyramids, having terminal dihedral ang^ of 1^7^
28', and the lateral edges rejuaced by the square prism oo P.

Cleavafte paralld to oo P. Yellowish-imte to honey-yellow, tranduoent, ^
nacreous lustre. Specific gravity 2*24. Hiudness 4*5 to 5 *0. According to D el ei a «
(Ann. Ch. Phys. [3] ix. 385), it contains 64*2 silica, 14*1 alumina, 4*8 lime^ 1*7 oar
nesia, 1*2 protoxide of iron, 0*6 soda (and loss), 13*4 water. Alger and Dana area
opinion that the mineral thus characterised is merely stilbite, the form of which hai
been incorrectly determined, and the analysis made with impure matexiaL

7*3

8-9

5*3

9-0

4*9

6-S

6*2

6-9

121

5*8

13*3

6-5

4*8

6-6

8*2

5-9

9-0

6-0

11-9

5-5

7-7

6*3

BEAN— BEBIRINE.

525

Phann. zdx. 125), fbimd, in the imripe seeds, another kind of sugar, which he at
fint regarded as a peculiar substance, designated bj him as pkaseomanniief from its
TCsembXanoe to raannita According to later inrestigations, however, it appears to be
Li«ttfiMi ^th inosite^ the saccharine sabstanoe which Schezer obtained tsom mnscolar

flesh.

tke Atk rfB§an Seed and Betm 8U^w.

Ash per cenu 1

Senal-
nldeor

F«<0».

Solphnrie
n^tide.

SiO>.

Carbonic

anhydride,

CO*<

Phos-
phoric an-

Chloride of

potatslum,

KCI.

Chloride
of sodiam,

KaCl.

In tttb-
stance on-
dried.

In sub-
stance
dried at
lOO^C.

1-0

1-3

2*4

•

38*0

2*4

— .

1-6

0*6

36*7

1*6

0-7

—

0-6

40*5

trace

0-4

8-4

28*7

—

— -

2*37

2-66

0-6

4-3

1-6

33*7

3-2

2*85

3-43

0-1

0-4

3*4

86*7

—

2-68

301

0-6

3-1

0-4

0-8

26*9

0-9

1-8

2-48

2-97

0-3

5-1

2-2

2*6

29*9

—

2-64

2-90

0-1

6-2

0-7

2*8

30*6

— .

8-2

2-63

2*94

0-3

6'Z

004

0*3

33*3

1*2

3*2

2-80

3-83

0-1

2-6

0-4

31*8

0*6

—

1-8

8*3

28*4

0*2

0-3

2-3

1-6

35*9

—

3*4

2-8

—

17*0

^-^

2*8

0-68

2-0

2-1

11-8

121

0*4

0-6

1-4

2-6

25*3

0*6

11*6

4-97

6*66

0-7

1-4

2-2

24*4

6*5

—

10-0

617

6*81

0-5

6-4

4-6

22-6

3*3

—

6-9

4*64

606

0-4

3-9

1-6

26-7

111

3*6

110

6*47

7*24

2-0

2-1

7-3

181

8*4

—

8*3

606

6-69

The name Beaumontite is also siyen by Jackson to a yariety of siliceous malachite,
allied mineral containing suLca, water, and oxide of copper.

An add contained, according to Maclagan, in the bark of
the jBebeeru or Smeeri (Nectandra Bodief)^ a tree growing in British Guiana. To ob-
tain the add, the bark is exhausted with water addmated with acetic add ; the
alkailist bebirine and sepirine, with which the add is in combination, are precipitated
by ammonia ; the filt^ed liquid is predpitated by acetate of lead ; the predpitate
decomposed by sulphuretted hydrogen; the clear liquid eyaporated oyer sulphuric
acid ; and the residue digested in ether, which dissolyes the add, but leayes the
ealovirtng matter. On eyaporating the ethereal solution, bebiric acid remains as a
white cxystaUine substance, haying a waxy lustre. By exposure to the air, it is gra-
dtaJQj reduced to a syrupy liquid. It melts a little aboye 200^ C, and sublimes la
tnfls of needles. With potash and soda, it forms deliquescent salts soluble in alcohol ;
spaaringly soluble salts with the alkaline earths; the lead-salt also ia but sparingly
soliiUe in aloohoL

mmaaauam or MB«Bmi«a, G»H«NO' or C»mNO».^An alkaloid dis-
eoregcd in 1834 by Br. Bodie of Demerara, in the bark of the bebeeru tree (vid. sup.).
Maclagan in 1843 (Ann. Ch. Fharm. zlyiii. 106), showed that Bodie's bebinue
was a mixture of two distinct alkaloida, which he denominated bebirine and sepirine.
The former of these was more exactly inyostigated in 1846 by Maclagan and Tillcy
(Phfl. Mag. xxyii. 186^ who assigned to it the formula C*^J3^N0*. But bebirine

526 BEBIRINE -BEECH.

was fiiBt obtained perfectly pure by y. Planta (Ann. Ch. Pharm. Izxvii. 333), who
aBsigned to it the formula above given.

Pre^araHon, — 1. The bark is exhausted with water containing sulphuric acid ; the
extract is concentrated, filtered, and precipitated by ammonia ; and the precipitate,
consisting of bebirine, sepirine, and tannin, is dried, dissolyed in acidulated water,
and decolorised with animal charcoal. The solution a^ain decomposed by ammonia,
yields a nearly colourless precipitate of beldrine and sepirine. As, howeyer, the
treatment with animal charcoal always occasions a certain loss of alkali, it is better to
triturate the precipitate while yet moist with oxide of lead or milk of lime, dry the
mixture oyer the water-bath, extract the two alkaloids by means of alcohol, and
eyaporate the alcoholic solution. To separate the two alkuoids, the product is ex-
hausted with ether, which dissolves only the bebirine (Maclagan and Pilley). —
2. The bebirine prepared by the process just described, is not quite pure, and does
not dissolve completely in ether. It may be purified by treating it with acetic acid,
adding acetate of leaa to the filtrate, precipitating the mixture with caustic potash,
washing the precipitate with a large quantity of cold water, and redissolving in ether.
The ethereal solution, when evaporated, leaves the bebirine in the form of a clear
yellow syrup, which is dissolved in a small quantity of strong alcohol, and the solution
IS added drop by drop to a considerable quantity of water, with constant agitation :
bebirine then separates in the form of a floculent precipitate, (v. P 1 an ta .)

Bebirine when dry, is a white, amorphous, odourless powder, which does not change
by exposure to the air, and becomes electrical by friction. It melts at 198^ C. to a
vitreous mass, which decomposes at a higher temperature. — By boiling with strong
nitric acid, it is converted into a yellow pulverulent substance. Heated with chromic
acid, it yields a black resin. It does not yield chinoline when heated with caustic
potash.

Bebirine is nearly insoluble in water, but dissolves readily in alcohol and ether,
especially with the aid of heat. The solution has an alkaline reaction, and a very
persistent bitter taste. It dissolves readily in acetic and hydrochloric acid, forming
bitter unciystallisable salts. It is precipitated from its solutions by dilute nitric
add.

HydrocJUoraU of bebirine is very soluble in water; and the solution treated with
caustic alkalis or their carbonates yields bebirine in white flakes, easily soluble in ex-
cess of the reagents. The chloromercurate is obtained by adding mercuric chloride
to the solution of the hydrochlorate ; a small quantity of hydrochloric acid or chloride
of ammonium increases the precipitate ; but an excess redissolves it The chhroaurate
is a brown-red precipitate. The chloropkUinate, C*'H*'N0'.HC1.RC1*, is an orange-
yellow amorphous precipitate, insoluble in hydrochloric add. The nil^hocyanaU is
a white precipitate ; the picrate yellow.

Stdphate ofhebirine in the impure state has been used as a remedy in intermittent
fever.

The bark of the bebeem tree, which has a bitter and astringent taste, contains
about 2*6 per cent of bebirine and sepirine, together with bebiric add and a peculiar
tannin ; the seed contains the same prindples, together with about 50 per cent, of
starch, which impedes the extraction of the bases and acid.

BBOXXTB. This name has been given to a mineral from Paynton in Devonshire^
which, according to Kenngott, is merdy a coral hardened into a chalcedonic or horn-
stone variety of quartz, intergrown with compact grey limestone.

WMBftXHm Fague sylvaHca. — Beech-wood recently felled, has a specific gravity of
0*9fl2, and contains 40 per cent, water ; after diying in the air, it has a spedfic gravity
of 0*590, and contains 18 to 20 per cent, water. After diying at 100^ C. it contains,
according to Baer (Arch. Pharm. [2] Ivi. 159), 46*1 to 48*3 per cent, carbon, 5-8 to
6*0 hydrogen, 46-6 to 45*1 oxygen, and 1'2 to 0*6 ash. According to Chevandier
(Compt rend. xxiv. 269), it contains 49*8 per cent C, 6*0 H, 43*1 O, 1*1 N, and
yields 1*06 per cent ash. According to Sprengel (J. techn. Ghem. xiii 384), the
air-dried wood yields 0*365 per cent ash, containing 0'14 crude carbonate of potash ;
and the leaves which fall in autumn yidd 6*695 per cent. ash.

The following table exhibits the composition per cent of the ash of beech-wood, and
of the leaves, a, ^, A are by Sprengel {loc. cit); 5, c (Witting, Pharm. Centr.
1851, 104); b, of wood grown on sandstone (bunter Sandstein), near Marburg; c of
>vood grown on the Muschelkalk, near Morschen in Kurhessen ; d, e,*/ (Heyer and
Vonhausen, Ann. Ch. Phann. Ixxxii. 180). The wood was grown on a basaltic
hill near Giessen. A hectare of surfiice produced yearly 2*672 cubic metres of stem-
wood {8cluithol£)\ 0-965 c. m- large branch-wood (Frugdholz) ; 0*769 c m. small
branch-wood (Siockhoh); and 1*878 c. m. of twigs (Ra'shoh); and these quantities

BEECH— BEER.

627

of wood extracted from the loil, in all, 51*8 kilograinmefl of aah, tis. the stem-wood
17'0 IdL, the Lirffe branch-wood 9*9 IdL, the small branch-wood 4*9 and the twig-
wood 19*6 kiL Hence a cubic metre of the stem-wood yields 6*842 kilogrammes
of ash; of large branch-wood 10*233 kiL; and of twig-wood 14*144 kiL The table
shows also that, reckoning from the bottom upwards, the proportion of alkali dimi*
nisheSy that of the phosphoric and aulphurio aetd increases ; while of silica^ the twigs
hare more than the stem, and the thick branchaB least of alL

Wood.

Wood with Bark.

LeaTce.

PotMb

Stem.

Laree
Branchea

Twigi.

•

S4'9

10-9

6*9

181

1»5

11-8

5*1

Soda •

i-si

0*3

8-1

1-7

1*8

0 7

1-0

Lime ...

27-4

13*5

43-6

39*8

37^

40*2

61-7

87-7

ICagnetIa . .

6-6

lS-0

6*4

101

13*4

9-0

6*1

Alumioa . .

s-s

(h06

.»

1-1

Ferric oxide

0-6

0-5

0*3

0-6

0-8

0-4

Mannnlc oxide .
Sulphuric anbTdride

7-4

8-4

trace

0*9

l-O

0-6

4 1

2*4

7*1

1-0

0-6

0-4

1*0

1-3

8Uice ....

6-S

6-3

2*1

6-2

0*5

8*2

27*0

28*5

Cubonic anhydride .

36-2

98-8

19-6

17-4

16*3

10*5

Phofphoric .
Ferric phoephate
Chloride of lodlnm .

—

5-6

7-5

6-0

10-3

6*6

15-1

6-7

0-6

0-1

0-8

0-1

0-3

Charcoal

•.

«•!

fiend ....

"•

107

3-7

The hark of the beech contains, together with the usual constituents of Tegetable
substances, about 2 per cent, of tannm, also a peculiar red substance, and another
which smells like Tanilla. The latter is soluble m alcohol, insoluble in water and in
ether; and bv flhaking up the alcoholic solution with hydrate of lead, and repeated
precipitation \iy water, it may be obtained as an amorphous white powder, with an
odour of Tanilla and a bitter taste. It dissolves in acetic acid and m alkalis; nitric
add oouTerts it into oxalic acid. (Lepage, J. Fharm. [3] zii. 181.)

Diy beech-bark yields about 0*6 per cent crude potash. According to Hertwig
(Ann. Ch. Fharm. zlvi. 97), it yields 6*6 per cent ash, containing in 100 pts. 3*0
soluble salts, consisting of alkaline carbonates, sulphate of potassium, and a trace of
chloride of sodium, and 97*0 pts. of insoluble salts, viz. 64*7 carbonate of calcium,
1 6 '9 magnesia, 2*7 phosphate of calcium, 1*9 phosphates of magnesium, aluminium,
and iron, and 9*0 sinca.

The ath of beech-nuts yields in 100 pts. 181 K*0. 7'6 Na»0, 196 Ca«0, 9*2 Mg»0,
2-5 Mn«0*, 16*5 P«0», 0*7 NaCL 1*6 SiO», 9*1 CO', and 9*4 charcoaL (Handw. d. Chem.
2** Aufl. iL [2] 649.)

8SBOB«inrT onb. Suils de/aine. C^^H^O*. — ^Beech-nuts yield, by pressure,
about 17 percent of a dear, light-yedlow, viscid oil, inodorous, having a mild taste and
a density ^ 0*9226 at 16^ C. It solidifies at 17° C, and is coloured rose-red by
nitric acid. It is a non-drying oil, and yields a white soap. It is used in cooking and
for illumination. Jtfixed with eight or ten times its bulk of water, and treated at 60°
or 80° C. with chlorine gas, it is converted into a chlorinated oil oontainixig C^H^IH)*.
Sromine acts on it with violence, but if the oil be cooled at the same time, the com-
pound C»*H*^rH)« is produced. (Lefort, Compt rend. xxxv. 784.)

is the wine of grain, and ia prepared from malt, or grain, generally barley,
which has been allowed to germinate. The grain is steeped for two or three days in
water, until it swells, becomes somewhat tender, and tinges the water of a bright
reddish-brown colour. The water being then drained away, the barley is spread about
two feet thick upon a floor, where it heats spontaneously, and begins to grow by first
shooting out the radicle. In this state, the germination is stopped by spreading it
thinner, and turning it over for two days ; after which it is agam made into a heap,
and suff(mred to become sensibly hot» wluch usually happens in little more than a day.
Lastly, it is conveyed to the kiln, where, by a gradual and low heat, it is rendered diy
and crisp. This is maJt, and its qualities differ according as it is more or less soaked,
drained, germinated, dried, and baked.
Ifalt is distinguished by its colour, as pale, amber, brown, or black malt, accord-

528 BEER.

ing to the different degrees of heat to which it hu been saljeefed. P^ nab is
produced when the diying temperature does not exceed 90^ to 100^ F^ lmbe^
coloured malt when the heat has been raised to 120^ to 126<^, and brown m^ at 160^
to 170^. Black malt, commonly called patent malt, is prepared bj rotstiiig ia
cjlindenlike coffee, at a heat of 860^ to 400° F. ; it is used as eolonriog matter in the
breweiy of porter.

Indian com, and probably all large grain, reqnires to be suffered to grow bto the
blade, as well as root, before it is fit to be made into malt. For this pupoae, it is
bnried about two or three inches deep in the ^nnd, and oorered with lo<»e euth;
and in ten or twelye days it springs up. In this state, it is taken xsp and vaahed, or
fumed, to dear it from dirt ; and then dried in the kiln for nse.

I>arinff the process of gennination, the albmninons matter of the bailey or otJur
grain isbronght into the peculiar state called diastase, in which it acta aa a ftnnoit
on the starch contained in the grain, converting it into dextrin and sugar, and thmby
rendering it soluble. A portion of the starch is, however, always left unchanged I7
the germinating process, and its conversion into dextrin and sugar is compl^ ^
the kiln>drying. Xhe benefit of this latter process is, therefore, not confined to tiie
mere expulsion of moisture from the grain ; indeed kiln-dried malt alvaja jieldi a
larger quantity of saccharine extract than malt which has been left to diy in the air at
OK&iary temperatures.

The diastase of malt is capable of converting into sugar a much laij^ qoantiiy of
starch than that which the grain itself contains : hence in the preparation of the ei-
tract, the malt may be mixed \n.th a certain quantity of unmalted barie^ or other
grain. In Belgium, large quantities of beer are prepared from malt mixed vith
potato starch.

To make beer, the malt, after being ground or cut to pieces in a mill, is pSaeed in a
tun or tub with a false bottom ; water at about 180° F. is then poured iqion it; and
the whole is well stirred about by suitable machinery. This operation is called moA-
ing. After the infusion has been left for a few hours to claxi^ or m^ the dear li^
or sweet wort is transferred to a copper boiler and boiled with hops; whidi gire it a
bitter aromatic taste, and perhaps also render it less liable to spoil hy keenng.
When the wort has been sufficiently boiled, it is drawn ftom the copper into larp
shidlow vessels, so as to cool it as rapidly as possible to the temperatora of the air,
and thereby avoid an irregular acid fermentation, to which it would otherwise be liable.
It is then transferred to the fermenting vats, which in large breweries are of ^reat
capacity, and mixed with yeast, the pr<^uet of a preceding operation. Tb» Uqmd is
therebv brought into a state of commotion ; the sugar is more or less oonvated into
alcohol and carbonic acid, which escapes as gas; and the nitrogenous matter of tlie
extract is converted into yeast, part of which is expended in keeping up the fermenta-
tion, while the rest rises to the surface. The fermentation is never suffered to no
its fhll course, but is always stopped at a certain point, by separating the yeast and
drawing off the beer into casks. A slow and almost insensible fermentation then
takes place, whereby more of the sugar is converted into alcohol, and the beer is lendoed
stronger and less saccharine.

Dimng this last process, the beer gradually becomes dear or fine, the solid m^
tides of yeast which float about in it during the fermentatioii, and render it mnodj,
being gradually brought to the surface and diseharged through the bung-holea of the
casks, whence the yeast is conveyed into proper receptades. A very efiectiTe 8^
rangement for this purpose is adopted at the extensive breweries of Measrs. Bass and
Allsopp at Burton-on-Trent, for a description and figure of which see Mtttpntft
Ckemistiy, voL i. p. 276. Frequently, however, it is found necessary to assist the
darification by means of substances called finings, whidi lay hold of the anspeodM
matter, and precipitate it to the bottom* Isinglaiis dissolved in sour beer is ofta
used for this purpose, also gelatin, white of egg, serum of blood. Carragheen moA
and the dried stomach of tiie cod, called sounds. It is best, however, when the
clarification takes place spontaneously, without the use of finings ; for all these sub-
stances tend to make the beer fiat, and prevent it from carrying a eood head. The
composition of the water used in brewing has a great influence on the result lin^
in particular appears to favour the clariflcation, by combining with the acids of
the malt-extract, and forming insoluble salts, which carry down the suspended
matter. The spring-water of Burton-on-Trent (not that of the river Trent) contains
19 per cent, of sulphate of lime, only a small portion of which is precipitated on
boiling.

The strength and taste of beer are susceptible of endless variety, according to the
quality and quantity of the malt and hope used, and the mode of conducting each
stage of the process, but especially the fermentation. If the first fermentation be

S££iIC*

529

■topped at an eazly stage, tbe beer will contain a considerable quantity of sogar and
comrazatrrelj little alcohol: it will be mild, and if bottled, will acquire the property
of efiexreecing strongly when the bottle is opened, because the carbonic add produced
by the subsequent slow fermentation, remains dissolved in the liquid, and escapes with
nolesce as soon as the pressure is remoyed. I^ on the other hand, the fermentation
be allowed to go on in the vat or in casks, till nearly all the sugar is converted into
akohol and tl^ carbonic acid escapes, the beer then becomes more alcoholic ; but if
the prooesB be sllowed to go on too long, it loses its briskness and becomes flat and
nniialatable. Stnmg beexs are those which contain a considerable amount of alcohol ;
subitantial been are those wlu(^ are rich in malt-extract; the latter are also said to
body.

The malt-liquors oonsumed in this countiy are of two kinds, Alb and Fobteb. Ale
is prepared fiom the paler kinds of malt» and in its preparation, the first fermentation
is cheeked at such a stage as to leave a considerable quantity of saccharine matter in
the Uqiior, which, by its subsequent conversion into alcohol and carbonic acid, may
keep up the briskness. The ale is mild or bitter, according to the quantify of hops
added to the wortw Pale ale is prepared from the palest mtdt dried in the sun or by
steam heat» and from the best and palest hoos. An essential point in its preparation
is to keep the fermenting temperature as low as possible, never allowing it to rise
above 72^ F. Sy this means, the formation of acetic acid is prevented, as also the
solution of the yeast by alcohol, which always communicates an unpleasant flavour to
the liquor, — ana the delicate flavour and aroma of the hop are preserved. Scotch ale
is a sweet strong ale; it was formerly flavoured with honey, but that practice appears
to be now aban£>ned. '

J^orter is a dark-coloured beer, prepared from a mixture of gJe, amber, brown, and
black malt. The following table (taken from Huspratf s Chemistry) exhibits the
eomposition of the vazioiiB mixtures employed :

Table of Porter Griste.

Now

Block.

Brown.

Amber.

PUe.

Total.

. 9

. 0

. 91

. 100

. 6

. 84

. 0.

. 60

. 100

. 2

. 30

. 10

. 68

. 100

. 8

. 2o

. 15

. 67

. 100

. 4

. 24

. 48

. 100

. 6

. 0

. 96

. 0

. 100

Of these the preference is given to the last two ; in the others, the excess of black and
brown malt introduces too much carbonaceous and useless matter, whence the porter
ttoqvircB a disagreeable taste, as if liquorice were added to it The fermentation of
porter in the vats is carried on till the original gravity of the liquid is reduced to
aboat one-third. Stout is merely a stronger kind of porter. Small beer, as its name
implies, is a weaker liquor, and is made either bv adcUng a large quantity of water to
the malt, or by mashing with a fresh quantity of water, the residuum left after ale or
poster has been drawn offi

The temperature at which the fermentation of beer is conducted, has a marked
effect on its quality, and especially on its power of keeping without tominff sour.
When the fermenting temperature ranges from 65^ to 90^ F., as is the case with the
beers of England, France, Belgium, and most parts of Germany, the beer gradually
becomes sour by contact with the air, the alconol being slowly converted into acetic
acid. But Bavarian beer, which is fermented at a much lower temperature, 8^ or 10^
C. (4fl*5 to 60^ F.), does not undergo this change. The difference arises from the
manner in which ^e fermentation takes place, and is explained by Liebig as follows :
Wort is proportionally richer in soluble gluten than in sugar, and when set to ferment
in the ordinary way, it evolves a large quantity of yeast in the state of a thick froth,
with bubbles of carbonic add gas adhering to it, whereby it is floated to the surface
of the liquid. Now the conversion of gluten into yeast is partly, at leasts a process of
oxidetion ; and when the liquor is covered with a thick scum, as just described, the
gluten still dissolved in the liquid, not having free access to the air, appears to take
oxygen from the sugar and other matters contained in the liquid, the formation of the
yeeet tbos going on at the expense of the sugar, which is consequently destroyed before
the whole ot the sluten is converted into yeast. Fi6m this cause, a quantity of free
gluten is left in we liquid, and on subsequent exposure to the air, this gluten acts as
* ferment, inducing the conversion of the alcohol into acetic add. In the Bavarian
pEoocM, on the contrary, the carbonic add, instead of escaping in large bubbles, which,
earrj the yeast to the surface, rises in minute bubbled in the same manner as £rom

Vox. L MM

530 BEER.

an efferreaciiig mui«nil water ; little or no seam fbrma on the soifkoe, Vat tlie jMit, k
it ifl produced, sinks to the bottom, and leaves the sorfiiee of the wort freely enond
to the air. The gluten is thus eonverted into yeast by atmo^erie oxidation, tad is at
last wholly removed from the liquid without decomposition of the sugar. Beer thu
fermented, is not liable to aoidiflcation by exposore to the air.

The kind of fermentation last described, is called bottom fermentaHim {Vntet'
gahruna\ and the yeast produced by it bottom feast ( Unterhefe) ; idnle the ordi-
nary &rmentation process is eallea top ftrmentatton {Obeiyaknma), md tiie
yeast which it produces top yeaat {Oherh^e\ These two kmds of yeaat difls
easentiallT in their ^pertiee and mode of action. The top-yeast ii gluten oxidind ui
a state of putrefaction, and the bottom yeast is the gluten oxidised by trtmaeoMm or
slow combustion. Each of them has a tendency to induce the partieiilsr kind of &^
mentation by which it was itself produced. (See Fbbmentjltiok.)

For further details respecting tne preparation and properties of beer, see the aitidM
BsEBand Bbewtno in the new edition of Ur^s Dictionary of Arts, ManHfaetuHtf ni
Mines ; also the article Bebb in Mutpratfa Chemistry^ and in the HeaMofitrhmA
der Chemie, 2** Aufl. il [1] 103*6

Analysis of Besb. — The normal oonstitaentB of beer are alcohol, outoie idd,
and extractive matters of malt and hope ; acetic acid is also present^ but iti imooiit
in good beer is very smalL

The amount of carbonic acid in beer is but small, not exceeding O'l to O-fi pa
cent even in bottled beer, and of this small quantity the greater poitioB (MI{m
as soon as the beer is opened. The strength of the fiK>th]ng will give a Tei^ good
idea of its relative amount. An exact estimation of the caxbonie acid is indeed
seldom necessary ; but if desired, it may be made by boiling a known quantity of
the beer in the flask-apparatus, represented in fiy, 6, p. 119, (art Aluukxtki.)
The carbonic add (anhydrous) then escapes as gas, while the vapours of vit«r
and alcohol given off at the same time are retained by the chloride of ealdiim in
the drying tube.

The amount of acetic acid is estimated by the usual proeesses of AaDooRir
(q.v,)

The quantity of extractive matter in beer may be determined by erapontiiis
20 grammes of beer in a platinum or porcelain dish, and drying the residue in an si^
bath (p. 620) at 100^^116° C. till it ceases to lose weight Before veigfain^ it
must be cooled under a bell-jar over chloride of calcium, as it is very hygrosoopie.

It is seldom necessary to examine the extractive matter any further. It eonsistB
mainly of sugar, dextrin, albuminous matter, and lupulin, the bitter principle of tke
hop. The amount of dextrin and sugar may be determined by moistening tlie diied
residue with water to a thin syrup, and graduiJly adding strong akohol as long as destzia
is thereby separated. The clear sugar-solution may then be decanted, and thedextria
freed from the remaining sugar by repeated solution in water and precipitatioB by
alcohoL The solutions of dextrin and sugar may tJien be evaporated to diynen, and
the residues weighed. The albuminous matter may be estimated from a separate piv-
tion of the beer by boiling it so as to coagulate the albumin, collecting the pracipitate
on a tared filter, then washing, drying, and weighing it. Lastly ue sum of the
weights of the dextrin, sugar, and albuminous matter, deducted from the total VBg)it
of the extract gives the quantity of lupulin.

The inorganic constituents of beer are estimated by evaporating to diyncsi a
known quantity of the beer, charring the residue, and then igniting it, as inthepicpazar
tion of plant-ashes (p. 419). They consist chiefly of the phos^ates of calaan sod
magnesium. Alkaline phosphates may likewise be founc^ but the greater part of
them is dissolved out during the maceration of the barley for malting. Common nUt
which is sometimes added to beer, will of course be found in the ash. Any eoosidtf-
able amount of alkaline carbonate may be attributed to alkali added to neotnliae fttt
acid in the beer.

The amount of alcohol in beer is ascertained by distilling 500 to 1000 grmBiei
(15 to 30 ounces) in a somewhat capacious retort, having its neck inclined npvwds aad
connected with a Liebig's condenser, receiving the distillate in a tared flask, vei^DBg
it, and determining its specific gravity at 16} G. (60^ F.), that of water at tlie sane
temperature being assumed « I'OOO ; or the proportion of aleohol may be fiiand hj
testmg the distillate with a delieftte alcoholometer. The weight per cent of alcohol if
then found by means of table A, which is an amplification or part of that gino
under Alooholovrtbt (p. 81), and thence the total amount of alcohol in the girea
quantity of beer may be found.

Suppose, for instance, 1000 gnns. of beer gave 616*38 grma. of distillate of speoK

.B££B»

531

gnTitj 0-98949 at 60^ F. ; then, according to the table, the distillate would contain
6*11 per cent aleohol, and therefore the 616*88 grms. of distillate wonld contain 37*6
gnna. aloohoL Now theee 37*6 crmB. of alcohol were obtained from 1000 grms. of beer ;
eonseqnently the amonnt of alcohol in the beer is 3*76 per cent. The trouble of
ealeolation may be sayed bj dilating the distillate till its weight becomes equal to
tliat of the beer employed; the n)eciflc grayity will then at once giro the percentage
by weight of alcohol in the beer. I^ for example^ the distillate after dilation exhibited
a specific grayity » 0*9982, the percentage of alcohol wonld be 8*76. If a Trallea*
alcoholometer were used, it woom show in the distillate^ before dilation, a percentage
by yolume of 7*6, coireoponding to 6*11 by weight In using the alcoholometer, it is
b«st not to dilate the distillate, unless the instroment is especially graduated for yeiy
weak KquidsL If the obeeryed speciflc grayity or alcoholometer-degree does not occur
in the taUe, the weight per eent. of aleohol will be found by interpolation.

Tablb a. — Specific Gravity and Strength of Spirits.

Volume
percent.

Weight
percent.

Specific Grarity.

Volume
percent

Weight
per cent.

Specific Gravity.

0-80

0-99860

4-6

3-60

0-99360

0*88

0-99836

4*6

3-68

0-99336

1-2

. 0-96

0-99820

4-7

3-76

0-99322

1-3

1*04

0*99806

4-8

3-84

0*99308

1-4

112

0-99790

4-9

3-92

0-99294

1*5

1*20

0-99776

6*0

4-00

0-99280

1*6

1*28

0-99760

6-1

4-08

0-99267

1*7

1*36

0*99746

6-2

4-16

0-99264

1-8

1-44

0-99730

6-3

4-24

0-99241

1-9

1*62

0-99716

6-4

4-32

0-99228

2*0

1*60

0-99700

4-40

0-99216

1*68

0-99686

6-6

4-48

0-99202

2-2

1*76

0*99672

6-7

4*66

0-99189

2-3

1-84

0-99668

6-8

4*64

0-99176

2*4

1*92

0-99644

6-9

4-72

0-99163

2-5

200

0-99630

6-0

4*81

0-99160

2-6

2-08

0*99616

6-1

4*89

0-99137

2-7

216

0*99602

6-2

4*97

0*99124

2-8

2-24

0-99688

6-3

6-06

0-99111

2*9

2*32

0-99674

6-4

613

0*99098

2*40

0-99660

6-6

6-21

0-99086

2-48

0-99646

6-6

6-30

0-99072

3-2

2*56

0*99632

6-7

6-38

0-99069

3*3

2*64

0*99618

6*8

6-46

0-99046

3-4

2*72

0-99604

6-9

6-64

0*99083

2-80

0*99490

6-62

0-99020

3-6

2*88

0-99476

7-1

6-70

0-99008

2-96

0-99462

7*2

6-78

0-98996

3*8

8-04

0-99448

7*3

6-86

0-98984

3-9

812

0-99434

7-4

6-94

0-98972

4-0

3-20

0-99420

7-6

6-02

0-98960

3*28

0-99406

7*6

6-11

0-98949 '

4-2

3*36

0-99392

7*7

6-19

0-98936

4*3

3*44

0-99378

7-8

6-27

0*98924

4*4

3*62

0-99364

7*9

6-36

0-98912

8-0

6-43

0-98900

The residue in the retort may be used fbr determining the amount of extractive
natter in the beer. For this purpose it is diluted with water, after cooling, till its
weight beeomes equal to that of the beer before distillation, and the amount of extra(s
tiye matter is then found from its specific grayity, by means of tables proyided for the
pinpoee.

The following is taken from a more detailed table in the ffandworterbuchf 2** Aufl. ii.
[1] 1081.

MM 2

632

S££B«

Tabu B. — Specific Grainiy and Strengik of MaU-Sxtrod.

SpmHAc
Gravity.

Ualt.ntnici

in 100 pU.

ofltquM.

teeclfle
Graviry.

aialt-cxtract
In 100 PU.
ofllquJd.

8pecl6e
OfETlty.

Malt extract

In 100 pu.

of liquid.

SMdfle
Gravity.

ialUtttnct

iBlMfCl

criiqaid.

1-000

0000

1-018

4-600

1-036

8-926

1-064

13-2S8

1-001

i>260

1-019

4-760

1*037

9170

1-066

18-476

1002

0-600

1-020

6-000

1088

9-413

1-066

137U

1-003

0-760

1021

6*260

1-039

9*667

1*057

lS-952

1-004

1-000

1-022

6-600

1040

9*901

1-068

14190

1006

1-260

1*028

6*760

1*041

10*142

1-069

14-428

1006

1-600

1-024

6-000

1042

10-381

1-060

14-666

1-007

1-760

1026

6-244

1-043

10-619

1-061

14-904

1-008

2-000

1-026

6-488

1-044

10-867

1-062

15-189

1*009

2-260

1-027

6-731

1-046

11096

1-063

15-871

1010

2-600

1-028

6-976

1-046

11-333

1-064

16-604

1011

2-760

1-029

7-219

1-047

11-696

1-066

15-837

1-012

3-000

1030

7*463

1-048

11*809

1-066

16070

1013

3-260

1-031

7706

1-049

12-047

1-067

16-302

1014

3-600

1-032

7-960

1-060

12-286

1-068

16-534

1-016

3-760

1-033

8196

1-061

12-623

1-069

16767

1016

4-000

1-034

8-438

1-062

12-761

1-070

17-000

1017

4-260

1-036

8*681

1-063

13*000

A more extended table of the specific grayij^ of pare fljrap, wfaick does not differ
greatly from that of malt-extraet^is given in Xfr^t DieHonary ofJrUt Mmftftxtwa^
and MineSf new edition, toL ii. p. 610.

The amount of alcohol in beer may in most caM« be calculated with snfiaait
accuracy for practical puipoees, from the difference between the ijpBcifle gnvity of tite
boiled and unboiled beer, according to the following principle : the wpvife grnit§ of
the unboiled beer is less than that of the boiled beer, in the same proportion at the ifiei/k
gravitff of spirit of wine of equal aleohoUe strength is less tkan that of loeUr. To
determine the amount of alcohol in beer accordingly, tJie beer is first freed from to-
bonic acid by brisk agitation in a capacious fla^ assisted perhaps by veiy gentle
warming, and its specific g^vit^ is accurately determined. It is then boiled to drive
off the alcohol, and the residue is diluted with water, tiU its weight beeoma exactly
equal to the original weight of the beer; it is then filtered, if neoessaxy, through ft
covered filter, and its specific gravity likewise determined. The amonnt of aleoboi ii
then calculated, as in the following example. Suppose the specific gravity of the snboiled
beer, freed f^m carbonic acid, to be 1*0260 ; and after bofling^ and dilution vith
water, to be increased to 1*0320. Then, acoordinff to the principle just statrd, the
spedfic gravity of pure spirit of the same aloohoBo strength as the beer, vill be to

thatof water as 1-0320 : 10260; thatis to say, it wiU be ^:^^ - 0-9932, which, ut

cording to the table, page 631, corresponds to 3*8 per cent.

The empirical rule fcft finding the specific gravity of spirit of equal strength vith
the beer is : JDivide the specific gravity of the tanhoiled beer by that of the boiUd 5Kf,
after its original weight has been restored by dilution.

It IB clear that the results obtained by tnis method (called in Germany the Sfie{fe •
Beer-test), wiU be more exact, in proportion as the composition of the beer diffisn \»
from that of pure spirit of equal strength, in other woras, the smaller the aaioimt d
of the extractive matter contained in the beer. For beers like those ofBatim,it
answers very well ; but for those which contain a larger amount of extract it Cftnooi
be relied on.

For Balling's Saeeharometrie method {saeeharimeirische Bierprobe), andFnehi'i
Hallymetric method (hallymetrischs Bierprobe), which latter consists in detenniniBg
the quantities of alcohol and extractive matter in beer by the quantity of oobuboo
salt which it is capable of dissolving, see Sandworterbuch der Cheme, 2**Aafl.ii-
[1] 1078 ; and Handbuch der teehnish^chemisehen Untersuekungen von P. JL Solky,
2** Aufl. Leiptdg, 1861, s. 360.)

The following tables C and D, exhibit the composition of various kinds of beer.--
See also Jahresbericht der Chemie, 1849, p. 708; 1860, pi 683; 1863, p. 768; 1855.
p. 862.

S££B*

533

Tablb C — Ateraff$JMOunt of Malt-extract and Alcohol in f/arums Kinds of Beer.

Name of Beer.

Lofndon Ale, for exportation
London Ale, otdinazy .
London Porter, for exportation
London Porter, ordinaiy
Bruaaelfl Xjsmbik .
BnisselB Faro
Bikte forte de Strasbomg
Biksre blanche de Paris .

WHte Beer of Berlin

Percentage of

Halt-extract.

7—6

6—4

7—6

6—4

6-6— 3*6

6—8

4—3-6

8-^

6*6—4

6*2—67

Alcohol.

6—8
4—6
6-6-
3—4

4*6—6

2*6-4
4—4*6

3-6—4
3—4-6

1-8-2

Tablb I). — Special Sesults of the examination of certain Beers,

Name of Beer.

LoBdoD' Ftatter (Barday and Peri^im) .

Porter (Berlin)

Bnrloo Ale

Scotch Ale (Bdinlnirgb)

Ale (Berlin) . ._

BruMcIa LamMk

Paro

»^ wm»» Jter. Ntinclien ■ • • • •

Bocktaier, Mttndiea

Bttvarteo Draught beer (Sekenkbier) MUnrhen
Bamriaa Store-beer (Liger-bier) Manchen I
leiMiithaold .... J
BaTarlan Store>beer, Mifncben
B«Tarian Drangfat^beer. Bruniwick
Bavarian Beer. WaUeehliiMcfaen
Pngoe Drangfat-beer
Pra^ueJTown Beer iStudt-Her)
r, Brimainek

JoetT'i Beer, Berlin
Werder'a Brown Beer, Berlin
White Beer, Berlin
Biive Mandie de XxNtrain
Louvafai

Percentage of

Malt,
extract.

6*0
6*8
IM
14 5
10*9
6*3
8*4
2*9
9*4
9*!!
6*8

6*0

8*9
6*t
4*8
6*9
10-9
14-0
S*6
3*1
3-7
8*0
4*0

43*0

Alcohol.

ft-4
69
47
6*9
8-6
7-6
6-5
4*9
4-6
4*1
3-8

3*1

4*3
3-5
3*6
9-4

8-9

1-86

«*6

1*9

6-5

1-9

Carbonic
acid.*

0*16
0^7

oTis

0*17

O-S

0*9

0*18

017

0*14

0*16

0'16

0-3
0-6

Water.

88-44

86*3

80-0

79-6

80*45

8.V93

90-9

99*0

85*85

86*49

90*96

89*75

91*64

91-1

91*5

90^7

fi.V3

84*7

94*8

94-9

91*8

98^0

89*5

53*1

Analysed
by

Kaiser.

Balling.

Zlurek.

HoflTtaiann.

Kidser.

Ziurek.

Kaiser.

Kaiser.
Otto.
Fischer.
Balling.
Balling.
Otto.
Ziurek.
Ziurpk.
Ziurek.
Le Cambre.
Le Cambre.
Freytag and
Busse.

The following are examples of the t)eTcent&ge composition of the ash of heer, the first
thi«e analysed hj Walz (Jahrh. pr. Pharm. iii. 312 ; Jahresber.derChem. 1866, p. 892),
the rest I7 Dickson (Plul Mag. xzxiii. 341 ; Jahresber. 1847-8, p. 1112).

Tablb R — Ash of Beer,

PMaab . • . .

Soda ■ • • •

Line ....

MamwsU

Solphnrlc add (S09) .

Chlorine

Sitica • • . .

Pheephorie add (P*0^)

"CS"

Fmob
MaDchMi.

FVmd
Spiycr.

SMlchAte
(14 amplM).

Ponst
(9 oteptw).

DiiUhi

Poftar

(laaaplM).

London

Poner

(6 Mmpla).

88^35
768
9*45
3*78
1-86
2-75
987

83*76

36*58
9*03
1*48
5*64
1*68
8*14
9-96

3169

37-(i8
6*59
9*98
466
9*56
31 1
10*99
83*10

82-99*8
90*9 - 88»fl
02— 9*0
0 \»m. 5*6
l*6>-ld*9
4*3^1 1-25
4*6—191
60—25*7

18*9-90*9

S3 8.-38-8

1'8— 1*6

0*9* 1*4

9*9— 6'4

7*4*-ll*4

I3*8ii.l8'6

12-5-18*8

240—427
0 8— 1*5
0-»-. 1*2
2*8-101
6*9-* 10*1
6*9-.l9-7
7-9— «W)

4*9 —31-1
9l*i( —50*8
0*8 — 6*9
0*1 — 1 1
1*6—12 2
6-5 — 1 1«3
825—197
9 -3 — 20P6

100*00

100 00

• The Manka in this column Indicate that the carbonic acid was not determined qtiantltatively in the

MX 3

^34

BEER.

Origina I Gravity of Beer-worta, — The oonyenion of sugar into alcohol bj fe^
mentation, is attended with a diminution of density in the liquid; oonseqnentl j the
specific gravity of beer is always less than that of the wort before fermentation. Now
by the revenue-laws of this country, the brewer is allowed a drawback upon all beer
that is exported, the amount being r^ulated according to the original gravily of the
wort Hence it is necessary that the revenue officer be poseessed of a method of
determining the original gravity, from the observed specific gravity and o»iqK)sition
of the beer, whereby he may check the record kept by the brewer.

If the non-volatile matt^ of beer consisted entirely of starch-^nigar (glucose), th«
determination of the original gravity woyld be a very easy matter : for it is foutd
that every 1 per cent, of alcohol in beer corresponds very nearly to 2 per cent of
sugar in the wort before fermentation : hence it would merely be necessazy to doaUe
the percentage of alcohol in the beer, add thereto the percentage of sugar as fouid
by direct experiment., and the sum would be the total amount of sugar in 100 pta. of
the unfermented wort ; the specific gravity would then be given by a saocharoioetff*
table, such as Table B, p 532.

For example, London porter (No. 1, of Table D), contains 6*0 per cent of nalt*
extract (which we shall suppose to consist of starch-sugar), and 5*4 per cent alcohol,
the latter corresponding approximately to 1 0*8 per cent starch-sugar. Hence the total
quantity of extract in the unfermented wort would be 6*0 + 10*8 « 16*8, giving a
specific gravity of 1'06.

But the actual problem to be solved is much less simple : for the wort cootaios
several other substances, all differing more or less in specific gravity from stardi-engar.
Hence the exact determination of original gravities can onl^ be effected by special
observations. The question has been examin^ by several foreign chemista, especially
by Ba lling of Prague, in his great work on Brewing* ; in this oountiy it has been
investigated by Messrs. Dobson and Phillips, of the Department of Inland BeTeme,
and more recently by Professors Graham, Hofmann, and Bedwood, firam whose
" Keport on Original Gravities," f the following observations are extracted.

The substances contained in beer-wort^ in addition to starch-sugar, are : L Btxtm,
which has not been converted into sugar in the process of mashing. 2. In many in*
stances, cane-sugar^ the use of which is now permitted in broreries. S. Cofm,
arising either from high-dried malt, or firom treacle or burnt-sugar, the use of vhidi
in the brewery of porter is also allowed by law. 4. A peculiar saccharine substance,
called " extractive substance," resembling caramel, possessing decided asid properti«9,
and not fermentable by yeast, even after boiling with sulphuric acid) 5. Axotised
or albuminous matter, derived firom the grain. 6. Alkaline and earthv salts.

The albuminous matter and the inorganic salts, have but little effect on tbe ooo*
parative densities of the wort before and after fermentation ; but the dextrin, cane-
sugar, caramel, and " extractive matter," all give solutions of leas spedfie giarity than
a solution of starch-sugar containing the same quantity of carbon, and thercfcrp
capable of yielding an equal amount of alcohol. The difiPerences are eibihitwl in tbe
following table.

Table F. — Specific Crravities of Solutions of various Saochabznb ScbstaxcUi m^ rf
Pais and Bbown Malt containing equal quantities of Cabbok.

Solution

of Statch-

»ugar.

Solution
of Cane-
sugar.

Solution

of
Dextrin.

Solution

of Extrac-

tire Sub-

•tance.

Solution

of
Caramel.

Solution

of
Pale Mall.

Solution

of Brown

Malt.

FutiorCme

•iigarcorreiMm-
InginlOOOPtfU

1010-4

1010-1

1009-7

1008-9

1008-7

1010-0

10100

1020-8

1020-2

1019-3

1017-8

1017*3

1020-3

1020-2

1031*3

1030-2

1028-8

1026-5

1026-2

1030-6

1042-4

1040*6

1038-3

1035*5

1034-9

1041-2

1041*2

100

1053-5

10510

1047-9

1044*7

1048-8

1052-1

1052-0

126

1064-9

1061-8

1057-3

1053-9

1052*8

10630

1062-9

160

1076*0

1072-9

1066-9

10630

1062*3

1074-2

1074-0

175

1087-8

1083-8

1067-6

1072-7

1071*8

1085-5

200

1099-4

1095-2

1086-3

1082-3

1081-3

1097*2

1097-2

226

1111-4

1106-7

1095-8

1091-0

1109K)

1109-0

260

* Die GakntngsehevUe wUsentck^fUick begrUndet wtd m ikrer Anwendmng aniS dk l»W^»«*"*'
BUrhrauertiy Branntveimbrennerei\ uml Hffenenettgwmgpr«kU$(Jk darge$tHU, Von Carl N. !'»)"»>*
Pngue, 1845. Or a shorter treaUie by he tfiine author : Die SaccAaromeiriseke Bter- mmi Brmmnaa'
mstsekprobe. Prague, 1846. See alto Handirdrterbuch d. Chem. »» Anfl. 11. [11 lOTSl
t Chem. Soc. Q. J. ▼. 829. ^

t It probably contatni glrcerln and succinic acid, both of which fubttancea hare been wo«b >V
Paateur to be produced in alcoholic fermentation.

BEEB. 535

These niimben plainly show that if an nnfermented wort oontains cano-sogar and
dextrin, and the g^nyily lost by fennentation is inferred from the quantity of alcohol
contained in the beer, on the sappoaition that the fermentable matter consisted wholly
of stareh-aogar, the estimated graTity will be too high ; and on the other hand the con-
xenion of a portion of the fermentable sn^;ar into nnfermentable eztractive matter, which
giTM s aoliitiQn of lower spedfle graTitj for the same amount of carbon, will cause
the estimate of the original graTilnr to come out too low ; indeed, the eztractiye substance
indicates only i^xmt fire-si^hB of the saccharine principle from which it is deriyed.

To obriate these difficulties, the authors of the Report were led to propose/or the deter-
mination of original gravities, a purely empirical method, which consisted in ferment-
ing flolntioits OT cane-sugar, starui, sugar, and malt-extxact, of known original gravity,
and making, at ten or twelye stages of the prooeas, two following observations : 1. Dis-
tilling a convenient quantity (4 fluid ounces) of the fermented liquid in a retort as
desenbed at page 630, diluting the alcoholic distillate with water, to the original
vdume of the liquid, and taking its spedfic gravity ; this deducted from the specific
gravity of water (■■ 1000^ 8^^^ ^® spirit-indication of the beer: e,g. if the
specifie gravity of the aloonouc distillate after dilution is 985-95, the spirit-indication
is 14'05. — 2. Diluting the boiled beer after ooolinfft to its original volume, taking its
specific gravity, and subteacting this, which is called the ex tract- gravity, from the
known original gravity of the wort before fermentation. The difference gives the
number of decreet of gravity losty corresponding to the spirit-indication previously
observed. The results of a long series of determinations of this kind on liquids of
known original gravity are pven in the " Report" in the form of tables : of these we
shall quote only those ii^ch embody the ^nenJ result of the inquiry, and are
intended for actual use in determining the original gravity of beer^worts.

Table G (p. 536) is to be used when the spirit^indication of the beer is found by
diitUlatUm in the manner above-mentioned. The first column gives the integers of
^irit-indication, the fractional parts (tenths) thereof being placed at the heads of the
other columns ; the numbers in these several colunms are the degrees of gravity lost
corresponding to the several spirit-indications. Thus, suppose that a sample of beer
distilled as above, gives a spirit-indication «> 9*4, and extract-gravity «■ 1030-6. On
the ninth line of the table, and in the column headed *4, is found me number 41-2,
which is the gravity lost^ and this added to the extract-gravity, gives 41*2 + 1030*6
— 1071*8 fbr the original gravity of the wort

As the distillation of the beer in a retort, and collecting of the entire quantity of
alcohol evolved, is an operation which occupies considerable time, and requires some
experience in manipulation, it is often desirable to obtain the spirit-indication of the beer
by an easier process. This may be done by first taldn^ the specific gravity of the beer
deprived of carbonic add by a^tation, then boiling it in a fla^ till all the alcohol is
e^eUed, diluting it to its origmal volume, and again taking its specific gravity. The
first result, the beer-gravity, deducted from the second, the extract-gravity, is the
new spirit-indication : thus if the beer before boiling has a specific gravity of 1044'7,
and after boiling of 1035*1, the spirit-indication is 9*6 degrees. By numerous
esroeriments in which the beer was Doiled in a retort, and me ^oohoUo ^tillate
ooUeeted as above, it was found that the second method, the evaporation-method,
gives a n»rit>indication nearly equal to that resulting from the first or distillation-
method, out always sensibly less ; thus the spirit-indication of a particular sample was
9*9 degrees by the first method, and 9-6 by the second. The experiments in question
were made on liquids of known original gravity, and thus a series of determinations
were obtained of the relation between the spirit-indication as determined by the
evaporaiion^metModt and the degrees of gnivity lost The general results of the
inquiry, as applied to malt-worts^ are given in the Table H, the arrangement of which
is the same as that of Table G.

The anthofs of the Report likewise suggest a rational method of determining
Ofriginal gravities, which is interesting in & scientific point of view, though not expedi-
ticms eflKmgh fbr practical use. It is as fbllows : First determine the amount of alcohol
in the beer by distillation. Then treat the residual liqoidi which generally contains
both staich-sugar and unfermentable extractive matter, with yeast, to complete the
fennentation, and determine the additional quantity of alcohol thus produced, making
m oocreetion for that which is introduced by the yeast itself I^istly, make up the
reaaalning spiritless liquor with water to the original volume of the beer, and take its
specifie gravity, a correction being also made for the increase of gravity caused by the
yeast The quantity of starch-sugar cofredponding to the corrected gravity of this
flointioii of extractive matter mav now be found from a table provided for the purpose ;
and this, added to the amount of starch-sugar corresponding to the alcohol, gives the
total quantity of starch-sogar, frtnn which the original gravity may be found by the
Baeeharometer tableSi

K V 4

586

SCiitB.

Table G. — To be used in aBcertaining Original GnTiUes hj the DmiLLA.nQv.

Pbogbs&

Degrees of Spirit-indication loith corresponding Degrees of Gravity toei ui Melt-

Degrees o'

Spirit-
iDdication.

•1

•2

•3

•4

•6

1
•7

•8

•9
2-7

0-2

0-6

0*9

1-2 ,

1-8

2-4

3-3

3-7

4-4

4-8

6-6

6-9

6-2

6-6

7-0

7-4

7-8

8-2

9'S

9-0

9-4

9-8

10-2

10-7

111

11-6

12-0

12-4

12-9

13-3

13-8

14-2

14-7

161

16-5

160

16-4

16-8

17-3

17-7

18-2

16-6

19-1

19-5

19 9

284

20-9

21-3

21'«

22-8

22-7

231

2S-6

241

24-6

26-0

26-6

26-0

26*4

86-6

27-4

27-8

28-8

29-2

29-7

30-2

80-7

31-2

31-7

32-2

32-7

83-2

33-7

34-3

34-8

36-4

36-9

36-6

37-0

37«

38-0

38-6

39-1

39-7

40-2

40-7

41-2

41-7

42-2

42-7

43-2

48-7

44-2

44-7

45-1

46-6

46-0

46*^

470

47-6

48-0

48-5

490

49-6

601

60*6

61-2

61-7

62-2

62-7

633

63-8

64-3

54-9

66-4

66-9

66<4

66-9

67-4

67-9

68-4

589

69-4

600

60-6

61-1

61-6

62-2

62-7

€3-3

63-8

64-3

64-8

65-4

66-9

66*6

67*1

67-6

«8*2

68-7

69-3

69-9

76-5

Table H. — To be used in ascertaining Original GiaTities by tbe ErAPOBiTioa

P&OCBS&

Degrees of Spirit-Indication vritA asrrmonding Degrees of Chravitg lost ts Udtr

Worts.

Degrees of

Sp:rii-
indication.

3-6
7-4
11-iEh
16-8
20-3
24-8
29-6
34-3
40-0
44-9
60-3
66-6
61-0
66-6
72 0

0-3
3-8
78
11-2
16-2
20-7
26-2
30-0
34-9
40-5
46-4
60-9
66-2
61-6
67-0

0-7
42
8-2
12-4
16-6
21-2
26-6
30-4

36 6
41-0
460
61-4
66-7
621
67-6

•8

•4

1-0

1-4

4-6

6-0

8-7

9-1

12-8

13-2

17-0

17-4

21-6

22-1

261

26-6

30-9

31-3

36-0

36-6

41-6

42-0

46*6

47-1

61-9

62-6

67 3

67-8

62-7

63-2

88-1

68-7

1-7
64
9-6
13-6
17 9
22-6
27-0
31-8
37*1
42-6
47^
680
68^3
63-8
69-2

•6 .

•7

2-4

6-8

6-2

9-9

10-3

140

144

184

18-8

230

23-4

27 6

28-0

32-3

32-«

37-7

38-3

430

43-6

48-2

48-7

63-5

640

68-9

69*4

64-3

64-9

69-8

70-4

•8

2-8
6-6
10-7
14-8
193
23-9
28-6
33-3
38-8
44-0
49-3
64-6
69-9
66-4
70-9

8-1
7-0
ll-l
153
19-8
24-8
29K)
83-8
3H
44-4
49-8
55-0
60-5
66-0
71-4

Adulteration of Beer, — The addition of eztraneons substances to beer, to gii« it
colour and heading, or to provide cheaper substitutes for the bitter of the hop^ spp^
to have been formerly carried to a great extent in this countiyk Dr. Ure says, m his
" Dictionarg of Chemistry " 4tb edition, 1831, p. 203 : "As long ago as the rasn of
Queen Anne, brewers were fbrbid to mix sugar, honey, Guinea pepper, essentiA oiitti
cocculufl indicua, or any other unwholesome ingredient, in beer, under a ostiu
penalty ; from which we may infer, that such at least was the practice of some; and
writers, who profess to discuss the secrets of the trade, mention most of theses aad
some other articles, as essentially necessary. The essentia bina is sugar boiled dovn
to a dark colour, and empyreumatic flayour. Broom tops, wormwood, and other bitter
phints, were formerly used to render beer fit for keei>in2, before hops were introduced
into this country, but are now prohibited to be used in beer made for sale.*'

BEER — BELLADONNA. • 637

" "By the pteeeat law of this oonntry, nothing is allowed to enter into the com-
position of beer, except malt and hofMS. Quassia and wormwood are often fraudulently
jntrodneed; both of which are easily dLscoverable by their nauseous bitter taste.
Tbey form a beer which does not preserve so well as hop beer. Sulphate of iron,
alum, and salt, are often added by the publicans, under the name of beer-heading, to
impart a frothing property to beer, when it is poured out of one Tessel into another.
JHolaaaes and extract of gentian root are added with the same yiew. Capsicum,
grains of paradise, ginger root, coriander seed, and oranoe pneel, are also employed to
gire pungency and flayour to weak or bad beer. The foUowing is a list of some of the
unlawful substances seized at different breweries, and brewers' druggists* laboratories,
in London, as copied from the Minutes of a Committee of the House of Commons ;
eocetdua indicus mvltum (an extract of the cocculus), colouring, honey, hartshorn
shaTin^pi^ Spanish juice, orange-powder, ginger, grains of paradise, quassia, liquorice,
caraway seeds, copperas, capsicum, mixed drugs. Sulphuric acid is frequently added
to bring beer forward, or make it hard, giving to new beer instantly the taste of what
is ei^teea months old."

This appeazB at first sight-, a rather formidable picture of adulteration : nevertheless
most of the articles enumerated are perfectly harmless, and of tJiose which are really
iignrioas, the use appears to have very mudi declined, partly perhaps in consequence
of the improved taste of consumers. Formerly there was a preference for what was
called good hard beer, that is to say beer in which nearly all the sugar and mucilage
had been converted into alcohol by fermentation : hence the use of sulphuric add,
as above stated, to simulate the taste of beer thus advanced in fermentation.
'With regard to burnt sugar or treade, which is added to porter to give colour and
body, its use is now legalised, and therefore it can no longer be regarded as an
adultBration.

Pierie acid and cocctdus indicus are sometimes added to give bitterness to beer,
especia]]^ to bitter ale. The latter of these substances is especially objectionable, as
it contains a very poisonous substance, viz. picrotoxin. Picric add may be detected
according to Laasugne, by treating the liquid, evaporated to half or a quarter of its
bulk, wiSi subacetate of lead, or shaking it up with powdered animal charcoal. Pure
beer is thereby almost wholly decolorised ; but if picric add is present, the filtered
liquid ivtains a lemon-yellow colour. This reaction is very delicate, sufficing to detect
1 part of picric add in 12,000 to 18,000 parts of beer. Subacetate of lead likewise
precipitates the bitter principle of the hop, and thereby deprives pure beer of its
bitterness ; but beer containing picric add remains bitter after being thus treated.
According to Pohl (Wien. Akad. Ber. xii 88), a still more delicate test for picric
add is obtained by immersing unbleached sheep's wool, or any fabric made there-
with, in the beer, boiling for six or ten minutes, and then washing the wort. K
the beer is pure, the wool remains white, but if picric add is present^ even to the
amoant of om^ 1 pt. in 126,000, the wool then appears of a canary-yellow colour, pale
or dun according to the quantity.

Picrotoxin may be detected, according to T. J. Herapath, by mixing the beer with
excess of acetate of lead ; removing the lead from the filtrate by sulphuretted hydrogen ;
filtering again, boiling for a few minutes ; then slowly evaporating the solution till it
becomes thickish ; shaking it up with pure animal charcoal ; collecting the charcoal,
which contains the picrotoxin, on a filter; washing it with the smallest possible
qnantity of water; then drying it at 100° C.; boiling it with alcohol; concentrating
the alcoholic filtrate ; and leaving it to evaporate. The picrotoxin then separates in
well defined quadrilateral prisms; or if the solution be rapidly concentrated, in
beautifnl feathery tufts. (For figures of these aystals, see Milapratfs Chemistry,
i-2«3.)

Inorganic substances added to beer will be found in the ash. Chalk is sometimes
added to sour beer to neutralise the add ; in that case, the ash will contain more lime
tlian the normal quantity. If copperas has been added to promote the heading, the
lipoid will give the reaction of sulphuric add with chloride of barium, and the ash
will contain an abnormal quantity of oxide of iron.

aBOmnrs VOXJLTEUI AMBXTp Spiritus sulphuris Begvini, consists essen-
tially of sulphide of ammonium with excess of sulphur.

nS&AJMmAf OSb OV« An oil expressed in Wurtemberg from the seed of
deadly nightshade (Atropa beUadonna), and uaed for illumination ana for culinary pur-
poBes. It is limpid, of ffolden-yellow colour, of insipid taste, and without odour. Sp. gr.
0-9250 at 6^ C. It thickens at - 16<> C. and solidifies at - 25°. The vu)Our8 which
it exhales during the process of extraction, intoxicate the workmen. The narcotic
prindple of the plant is retained in the marc, which cannot therefore be used as food
£or cattle. (Gerh. ii 881.)

538 BELL ADONNINE — BENZAMIDE.

An alioloid said to ezirt in Airopa bettadoima.

See Tin PTBITB8.

A fatty subetance pxepazed fiiom Bmmeee naphtha.

Kobell*8 name for NnsDUi-OBa.

The oQ expressed from the fruits of MbrinffalhtxBd^ JkA;
Gtttlandina fnoringa lion. ; or Moringa oletfera Lam. It is eoloorlcfls or dighUy
yellow, of specific grayity 0'912, thick at 16^ C, solid in winter. It is odonrlas, tnd
has a mild taste, is neutral to test-paper, and does not readily beeome landd. It b
used in perfumery to extract the odorous principle of framnt plants. In India it is
used as an embrocation for rheumatism. According to Y dicker (Ann. Ch. Fharm.
Ixiy. 342), it is saponified perfectly by potash, 400 grammes yielding aboot 18
grammes of a mixture of solid fatty ados, together with oleic acid The solid £%
acids are: I. An acid soluble in strong alcohol, insoluble in ordinary alcohol, meHing
at 83^ C. and containing 81*6 per cent carbon and 13'8 hydrogen, numbers vfaieh
approximate to the formula C*H**0'; but the quantity obtain^ was too raiaU for
complete inyestigation. — 2. Ordinary margaric acid. — 3. An add lesembliag stetrie
acid, and called by Yolcker, benio and.

Another kind of oil of ben, said to be obtained from the seeds of Mcfim apten,
yields by saponification four fixed fktty acids, yiz. stearic acid, margaric add, and tvo
peculiar adds, bemc acid and moringio add, (Walter, Gompt rend. xiiL 1143.)

BBWZO AXJtDm This name has been applied to two different fiitty adds, men-
tioned in the last article, both obtained from oil of ben, the one by Yolcker, the other
by Walter. For distinction, Yolcker^s add, which has the higher melting point; maj
be called benosteario aoidf and Walter^s henomargaric acid.

Bbnokaboabio Aoid, C**H'*0', crystaUises from its alcoholic solutbn in Tery boUy
nodules, melting at 52^ or 53^ 0.

Benomargarate of ethyl is yeiy soluble in alcohol, and separates from the sohtira
in a crystafiine mass. It melts at a yery low temperature, eyen at the heat of th«
hand. (Walter.)

Benostbabic Acid, C**H*K)' according to Yolcker, C**H**0* according to Strecker
(Ann. Ch. Pharm. Ixiy. 346). — The latter formula agrees with Yolcker's analysis better
than the former. It is a white crystalline f&tt melting at 76^ C. and solidifying it
70° C. to a shining white crystalline mass, composed of needles; which may he mhbed
to powder; it is soluble in alcohol, and bears a strons; resemblance to stearic acid.

Bcnostearate of sodium, O'H^aO*, is obtained by saponifying the acid vith car-
bonate of sodium, and dissolying the dried soi^ in absolute alcohol The alcoholic
solution solidifies after a while to a gelatinous pulp, which is resolyed into emtallise
grains by drenching it with a lai^ quantity of alcohoL The 6art«m-salt, (T'H'BaO',
is precipitated on mixing an alcoholic solution of the sodium-salt with chloride of
banum. The lead-Bsltf C*'H^aO', is a white predpitate obtained by mixing the
soda soap with acetate of lead.

Benostearate of ethgly C^H^'O'.CBP, is obtained by passing hydrodiloric add gis
through a solution of the add in absolute aloohoL It is a crystalline mass, melting at
48° or 490 c. (Yolcker.)

Syn. with hydride of benzoyl See BssnEOTL, Htdbids op.

Syn. with Oxtbbnzakio Acid {q. v.)
C'H'NO « N.C'H»O.H*.— 2W<rt& of Bensogl and i^N^wyw.
Liebig and Wohler, Ann. Ch. Pharm. iii. 268 ; Fehling, ibid. xxyiiL 48; Schwars,
ibid. Ixxy. 195 ; Laurent, Bey. Sdent xyL 391 ; Gerhardt^ Trait^ iii- btxr.

This body may be obtained in yarious ways. 1. By the action of anunonia on tio-
mide, ddonde, or cyanide of benzoyl. Chloride of benzoyl, when saturated with p(^
fecUy dry ammonia, eyolyes heat and solidifies into a white mass of bennmide and
chloride of ammonium, which must be repeatedly broken up, lest any diloride of hea*
zoyl be endosed in it, and so escape the action of the ammonia. The ssl-anunoniae is
extracted with cold water, and the benzamide crystallised from bdling water. 6e^
hardt prefers pounding chloride of benzoyl in a mortar, with excess of oemmeraal e8^
bonate of ammonium, heating the whole gently, extracting with cold water, and
crystallising the residue from alcohol or boiling water. Laurent prepares it by miiing
an alcoholic solution of chloride of benzoyl with aqueous ammonia. — 2. By the action
of ammonia on benzoic anhydride. — 3. By the action of ammonia on benzoate of ethvl.
The reaction takes place slowly at the ordinary temperature, more rapi^y when the
ether is heated with aqueous anunonia oyer 100^ C. in a sealed tnbe rOumas).— 1 By
boiling hippuric add with water and peroxide of lead (Schwarz, Fehling); or by
heating it m a stream of dry hydrochloric add. (Strecker.)

BBNZAMIDE. 5'69

When its hot aqaeons flohition 10 cooled saddenljri bensamide separatee in small
peufy crystaia, reeemblinff those of potaseic chlorate. When it is cooled slowij, it
aoJidiftee into a maaa of white shining needles, in which cayities form after a time, con-
taining one or more large crystals ; me transformation extends gradnallj thiongh the
whole mass. The finest ctTstals are obtained from a solution containing a little
potash or ammonia. The oystals belong to the trimetrie system. Benzamide is in-
odorooSy almost insoluble in cold water, soluble in hot water (especially if it contains
ammonia), in aleohol, and in ether. It melts at 116^ C, and soudifles on cooling to a
oystalline mass; between 286^ and 290^ it Tolatilises undecomposed ; its Tapour
■meOs sli|^tly of bitter almonds, owing to the formation of some beoaonitrile, is yery
inflammable, and boms with a smoky flame.

When yapour of bensamide is paned through a red-hot tube, it is but slightly de-
composed, a small portion of a sweetish oil being formed, which, according to Gerhardt,
is bensonitrile. It is decomposed at a moderate heat^ when passed t^ugh a tube
filled with pumice-stone, yielding hydrogen, nitrogen, carbonic oxide, and benzol
(Barreswil). Seusamide is not decompiled by cold caustic potash; but on boiling,
potassic benxoate is formed, and ammonia eyofyed. It is similarly decomposed by
ooilii:^ with strong adds, the solution on cooling d^ositing benzoic acid, while it re-
tains the ammonium-salt of the acid employed, when baryta is heated with benza-
mide, it undergoes a kind of fusion, and appears to be conyerted into hydrate of
barium ; ammonia is eyolyed, together with the oil which Gerhardt regards as benzo-
nitrile. Benzamide, heated with potassium, yields cyanide of potassium and benzo-
nitrile (cyanide of phenyl), but no ammonia. Heated with benzoic anhydride, or
chloride o£ benzoyl, it yidcU benzonitrile and benzoic acid :

CH'NO + C"H»0« « 2C'HK)» + C'H*N

Bens, anhjrd. Beaz. add. Bensonitrile.

CHIJO + CrHK).a - CTE[«0« + C»H»N + Ha

Bensonitrile is also formed when bensamide is heated alone, or in a stream of dry
hydrochloric add (Huidw.) ; or treated with phosphoric anhydride or pentachloride of
phosphorus. Benzamide is not decomposed by boiling wiUi water and peroxide of
lead ; but if hydiodiloric or sulphuric acid be added, and the whole boiled, filtered,
mixed with ammonia^ and exposed to the air, it turns brown, and deposits a mould-
like substance.

When benzamide is gently heated with fuming hydrochloric add, it dissolyes, con-
bining with the add, and forming hydroehlorate of hemamide^ CH^NCHCl, which
separates on oooling in long aggregated prisms. It is a yery unstable compound ; the
crystals giye off hydrochloric add when exposed to the air, and in a few days hare
become opaque, and lost the whole of their add. (Dessaignes, Ann. Ch. Fhys. [3]
xxxiT. 146.)

Bensamide is a primary amide, t. e. it represents 1 at. KH* in which IH is replaced
by benzoyL The remaining 2H may be wholly or partially replaced by a metal, or
an organic add or basic rrcide, secondary or tertiary amides or alkahunides being
formed. Those alkalamidee which contain organic radicles are described under the
corresponding amine ; the amides and those of the alkalamidee which contain a metal
will be desci%ed here.

Benzomereuramide, C^«HgNO - N.(7H»0.Hg.H (Dessaignes, Gerhardt,
Joe. eiiJ) — ^Aaueous benzamide dissolyes mercuric oxide abundantly, and the saturated
solution solioifles to a crystalline mass, which is coloured with excess of oxide. This
is treated with hot alcohol, and the solution on cooling deposits benzomercuramide in
white shining lamins, which may be washed and dried at 100° C. It is readily soluble
in alcohol and boiling ether. It is yiolently attacked by chloride of benozyl, yielding
benzoic add, boizonitrile, and chloride of mercury.

Aqneons benzamide also dissolyes small quantities of cupric and argentic oxides ;
but the compounds haye not been examined.

Benraeetosulphophenamide. C»*H"NSO« - N.C»HK).C«H»O.C^»SO«— Pro-
duced by the action of chloride of acetyl on benzosulphophenylaigentamide.

Btngoeumylaulphophenamide, C»H»NSO* - N.CHK).C"H"O.C^»SO», is
obtained by the action of chloride of cumyl on benzosulphophenargentamide ; it crys-
tallises from ether in conftised prisms.

BenMosalieylimide, C"H^O« - N.C'H"O.0'H*O" (Limpricht, Ann. Cb.
Fharm. xdx. 260).— Obtained by heating benzosalicylamic acid (benzosalicylamide) in
a small retort to 270° C., until about ^ has yolatilised, and boiling the residue with
small quantities of alcohol, to remoye the undecomposed add. The pulyerulent benzo-
aalicyumide is dissolyed in a larger ouantity of boiling alcohol, whence it separates on
cooling in small yellowish needles. It is soluble in about 1000 pts. boiling alcohol.

540 BENZAMIDE.

Bensosulphophenamide. C»«H"N80» - KCrHK).C«H*SO«.H (Gerhardt and
Chiozza, Ann. Ch. Phjs. [8] zlvL 145). — Obtained bj heating equTalent onantitiea
of chloride of benzol and sulphophenamide to 140^ — 145^ C, as long as hToioehlorie
acid is evolyed. The fluid mass crystallises on coolixig, and is recmtailised from
.boiling alcohoL Forms shining, colourless, tnmeated, interlaced needles^ which are
slightly soluble in cold water or ether, readily in aloohoL It has a stroQg add reme-
tion, and is readily soluble in caustic alkalis. It melts between 135^ and 140° C. ;
when quickly heated, it bums, gires off yapours of bensonitrile, and no longer solidifiea
on coohng. Its anunoniacal solution becomes syrupy when gently eraporated, and
finally soHdifles into a radiated mass, which Gerhardt states to do the add amoMmiiim-
salt of betuosidph<^henamw acid, C"H»N»S»0« - NH».(C>«H»«NSO«)«. This salt ia
yery soluble in water and alcohol, but insoluble in ether. When an add is added
to its aqueous solution, an oily substance separates, which soon changes into needles
of benzosulphenamide.

Benzosulphophenamide, like many other amides, behayes like a hydrate wbeo acted
on by pentachloride of phosphorus, forming the diloride of a peculiar body, wliidi
Gerhardt calls bensosulpiophenamidyL

Cwff^NSO* + PC1» « C»«H"NS0«.C1 + pa«o + Ha

Chloride ofbraso-
sulphopbenamldjl.

The reaction does not take place till heat is implied. The new compound ia deeofm-
posed by heat into benzonitrile and chloride of sulphophenyL When it is tritu-
rated with carbonate of ammonium it forms an amide, hmfonUpiopkenamidvittmide,
N.C"H"NS0'.H', which crystallises from alcohol, and is yezy sfighUy soloble in
ammonia. (Gerhardt, dted in Handw. it [1] 884.)

Bengoaulphoj^henargentamide, C"H"AgNSO««N.C^K).(>H»SO«JLg. — When
nitrate of silyer is added to a boiUng aqueous solution of bensosulphophenamide con-
taining a little ammonia, there is no predpitate ; but on cooling, this compound separmtcs
out in colourless needles. It is but slightly soluble in cold water, readOy in aloi>h<4.
It is decomposed b;^ heat, giying off sulphurous anhydride and bensonitrile, and leaving
a residue of metallic silyer and carbon. Its solution in strong ammoma yields on eva-
poration, fine rose-coloured crystals, which contain the elements of 1 at. benzosnlplio-
phenamide + 1 at. ammonia. They are readily soluble in boiling water ; the solution
on boiling deponts crystals of benzosulphophenaigentamide ; the addition of an acid
separates benzosulphophenamide. Gerhardt reguds this compound as a dianude,
N'.G^HK).C*H*SO'J^^.H', a view which the absence of a diatomic radide renders
imraobable.

BeneotulphofhenyUodamide, C"H>«NaNSO« - N.C*H»O.C«H»SO«.Na.— Ben-
zosulphophenamioie diBSolves in sodic carbonate with evolution of carbonic anhydride ;
the solution is evaporated to dryness, and the reddue exhausted with boUin^ aleobol,
which deposits the compound on cooling in opaque nodules. It is soluble in water ;
acids separate from it Denzosulphophenamide. (Gerhardt, dted in Qandw. iL
[1] 884.)

Dibengo sulphophenamide. C«H'*NSO* - N.(C'H»0)«.C>H«0. (Gerhardt
and Chiozza, toe, ciL) — Obtained by the action of diloride of benzoyl on bensosnlpbo-
phenargentamide. Chloride of silver is formed, together with a visdd maas* whi^
dissolves in ether, and crystallises in large brilliant prisms. It melts at 105^ C^ and
is slightly soluble in ammonia. It cannot be obtained by the action of diloride of
benzoyl on benzosulphophenamide.

Benzoyl enters into the composition of certain biamides and triamides, forming
compounds, which will be described under the original diamides and triamides
referred to.

SuUtitutioti'produets of Bensamide,

Bromoheng amide ia not known. — ^Benzamide dissolves in bromine, withoixt evo-
lution of hydrobromic acid ; the solution, after some days, deposits deep-red crystals,
having the compodtion C^ITNOBr*, which may be regarded as the hydrobromate of
bromobenzamide, C^9rN0.HBr. The crystals are decomposed dowly by water, im-
mediatdy by ammonia, with separation of benzamido. (Laurent.)

Chlorohemamide, C^H«C1N0 « N.C'H*aO.H» (Limpricht and Uslar.
Ann. Ch. PhaTm. di. 263). — Obtained by dissolving chloride of dilorobenaoyl in
strong aqueous ammonia; the solution deposits yellow lamina of chlorobenzamide^
which are purified by recrystallisation from hot water or alcohoL It is insoluble in
cold water ; it fuses at 122^ C, and sublimes in small quantities. The compound ob-
tained by Gerhardt and Drion (Ann. Ch. Phys. [3] zlv. 102), by tritnrating
chloride of chlorobenzoyl with carbonate of ammonium, has the same compodtion with

BENZAMIL ~ BENZENE. 541

the alMnre, but difibrs from it di^tly in pnperdeB, being insoluble in water, soluble
in alcohol or ammonia, whence it ciyBtaUisea in fine needles. It eyolves ammonia
when boiled with potash.

Nitrobenzamide, (rH«N«0» - N.C»H\NO«)O.H«. (Field, Ann. Ch. Pharm.
Izr. 45. Chancel, Compt. Chim. 1849, 180.) — Obtained in small quantity by fbsing
nifcrobenaoate of ammomum. Better, by adding aqueous ammonia to a solution of
nitrobenzoic ether in a rather large quantity of alcohol, and allowing the mixture to
stand for some days till it is not rendei«d turbid by water. It is then eTapo-
rated on the water-bath till it crystallises on cooling ; and the dystals are purified
by reetystallisation from mixed alcohol and ether. It is also formed by the action
of ammonia on chloride of nitrobenzoyL Nitrobenzamide is slightly soluble in
eold, readfly in hot water; also in alcohol, ether, or wood*spirit. From these
latter solutions it crystallises in long needles, or, by slow eyaporation, in laige tables
resembling gypsum. It fuses above 100^ C, and dystallises on cooliuff. When boiled
with Bizong potash, it forms potassic nitrobenzoate. Its aqueous solution is decom-
posed by sulphide of ammonium, as follows :

(rH«NK)« + 3H>S - C'H'NK) + 2H«0 + S"

Pbenyl-
carbamfde.
(Pbenjl-orea.)

Vinitroheng amide, CH»N«0» = KCH^O^yCH* (Vo it, Ann. Ch. Pharm.
-rm-w 105.) — When dinitrobenzoic ether is digested for some days with alcoholic
ammoniA, it forms a blood-red solution, which deposits dinitrobenzamide in yellowish
IflmiTMM and prisma. It has a bitter taste, and dissolves sparingly in cold, more readily
in hot water ; the solution is neutral It melts at 183^ C, and is decomposed by
furOier heat. Its ammoniacal solution is not precipitated by nitrate of silver.

Thiohengamide, Schoefelheneamid. Betuanude wlfur^ CTH'NS - K.C^H'S.H*
(Cab ours, Compt. rend, zxvii 329). — ^When a solution of benzonitrile in slightly
•iwiTn/^wiAAnl alcohol is saturated wiui sulphuretted hydrogen, the liquid becomes
brownish-yellow ; and i^ after some hours, it is boiled down to ^ its volume, and
water added, it deposits yellow flakes, which dissolve in boiling water, and separate
on cooling in long yellow silky needles of thiobenzamide. It is decomposed by mer-
curic oxide, yidmnff mercuric sulphide, water, and benzonitrile; by potassium,
yielding potassic sulphide and cyanide. F. T. C.

mmanLBMBEL, C*H»NK)* (?) (Laurent, Bev. sclent, xix. 446.) — Crude
Htter-aimond oil, shaken up wiui potash, is distilled till about ) has passed
oretr, the residue dissolved in ether-alcohol, and ammonia passed into the solution.
Hie deposit which forms is separated and boiled with a large quantity of ether ; and
the solution on cooling deposits silky crystals and a white powder : the latt«r is ben-
zamiL It is nearly insoluble in alcohol, difficultly soluble in ether. It melts at 1 70*^ C,
and solidifies very slowly. On dry distillation, it yields a substanbe soluble in ether.
It dlsaolTes in alcoholic potash, and the solution, on cooling, deposits crystals which
have not been examined. F. T. C.

Syn. with Phenylbenzamide. See PEBNTLumra.

C«H«, or O^IP,^Benzine, Hydride of phenyl, Bicarburet
ojltydtown, (Faraday, Phil. Trans. 1825, 440. Mitscherlich, Ann. Ch. Pharm.
iz. 39. Piligot, Ann. Ch. Phys. [2] IvL 59. Mansfield, Chem. Soc Qn. J. i. 244.)
— IHflcovesvd by Faraday. It is a product of the decomposition of many organic com-
pounds, being formed: 1. When benzoic add is heated with caustic lime or baryta
(Mitscherlich), or when its vapour is passed over red-hot iron (Darcet, Ann.
Ch. Pliys. [2] Ixvi. 99). — 2. When phtalic acid is heated with caustic lime
(Marignac, Ann Ch. Pharm. xlii. 217), or insolinic add with baryta (Hof-
mann). 8. By dry distillation of quinic acid (Wohler). — 4. By passing vapour
of beigamoi-oil over red-hot lime (Ohme, Ann. Ch. Pharm. xxxL 318). — 5. By
pBTfriBg £its through red-hot tubes (Faraday). — 6. By dry distillation of coal
(Hofmann, Mansfield). — 7. In small quantity, when acetic acid or alcohol is
passed tiirough a red-hot tube (Berthelot, Compt rend, xxxiii 210). It is also
found in Bangoon tar. ( De La Rue and MuUer.^

The readiest method of preparing pure benzene, is to distil 1 pt benzoic add with
8 pts. slaked lime at a gently increasing heat; the mixture of benzene and water which
passes over is shaken up with a little potash, the benzene decanted, dried over
chloride of caldum, and rectified on the water-b«th. 3 pts. benzoic add yield 1 pt.
benzene. The most abundant source of benzene is coal-tar ; but the product obtained
from this source is very impure, containing several higher hydrocarbons, volatile
alkaloids, and other substances. To obtain benzene pure, Mansfield shakes up the

542 BENZENE.

light oil obtained by the distillation of coal-tar with dilate anl^hiizifl idd, then vith
water, and then with potash, in order to remove all the adds and alkaloids thit it
contains, and submits the washed oil to repeated fractional distaUation; the portioii
which passes over at 80^ — 90^ C. is oooled to — 12^, when the benseoe oyBUOiaes,
and is purified firom liquid substances by preasure. A better method is to disfl
the washed light oil in a metal still, and to pass the vapour iqmards throog^ a tube
surrounded with boiling water, and then into a oooled receiver; tiios the oik vfaidi
boil above 100^ C. are condensed and run back into the stiU. The distillate is
similarly treated, the water round the oondensing-tube being k«pt at 80^G. and the
distillation stopped when the heat in the retort rises to 90°. Tnis seocmd distillate^
(only half of ^Anch solidifies at 20° ), is shaken up with ^ voL strong nitrie aeul, de-
canted, and shaken up with 4 vol. strong sulphuric acid, rectified withoat deeaatatioD,
and the product purified as oefore by coolins and preasure. Commercial benzeiie is
always very impure, containing many higher nydrocarbons; it may be appnxDmatdy
purified by distillation in the water-bath.

At ihe ordinary temperature, benzene is a limpid, colourless, strongly refrioting
oil, of specific gravity 0-85 at 16°*5G. (Faraday, Mitscherlich), 0*8991 at OP
(Kopp). When cooled, it solidifies into fern-like tufts, or into hard masses lika
campnor, which melt at 6^'6 C, expanding in bulk at the samd time, and solidify
again at (P. At — 18°, it is hard, brittle, and of specific gravity 0*956. It Boils at
80°'4 at 776 m m. (Kopp), at 86° (Mitscherlich), and volatilises undeoon^osei
Its vapour-density is (ezpt), 2*77 (calc.), 2*704. It has a pleasant smeD. It is
scarcely soluble in water, but imparts a strong odour to it ; reaoily soluble in alcohol,
ether, wood-spirit, and acetone. It dissolves sulphur, phosphorus, and iodine, espe-
cially on heating; fixed and volatile oils, camphor, wax, mastic, caoatchoiie, iai
gutta-percha, abundantly; gum-lac, copal, anime, and gamboge, in small qnsntitj; I

quinine, somewhat readily ; strychnine and moxphine in small quantity ; eincholli]>^
not at aU (Mansfield). Impure benzene is much used to remove stains from
silk, &c

Benzene is very inflammable, and bums with a bright smoky flame. A nixtue of
1 vol. benzene with 2 vols, alcohol of 0*85, forms a very good lamp-oil; a laiger pio-
portion of benzene gives a smoky flame. When vapour of benzene is passed tbroo^
a red-hot tube, carbon is separated, and a gaseous hydrocarbon formed. Chlorine and
bromine (not iodine), act upon it in the sunshine, forming substitation-inodactB (see
below). Strong nitric acid converts it into nitrobenzene ; according to Aoel, the same
result is obtained by repeated distillation with dilute acid. SuMurie onMriii at
fumifng ndphurie acid converts it into sulphobenzide and snlphopnoiylie add; stioog
non-fuming sulphuric acid into the latter product only (G-erhardt). Aoooiding to
Mansfield and Mitscherlich, the non-fuming acid has no action upon it f&tatshm,
aqueous alkalis, and perchloride of phosph^tis, do not act upon benzene, ereo wbai
heated to its boiling point; neither does aqueous chromic acid (Abel), or phosgene
gas in sunshine. (Mitscherlich.)

Church (Phil. Mag. [4] xiiL 415) describes, under the name of Perubmuite, a
hydrocarbon obtained by imn from the light oil of coal-tar, which is isomerie vith
benzene, but has a different smell, boils at 97°*5 0. and does not solidi^at-SO^-
Nitric acid converts it into nitrobenzene ; fuming sulphuric acid into an add iaonierie
with sulphophenylic acid, but whose copper- and bazium-aalts are somewhat different
in properties from those of that acid.

Hofmann (Ann. Ch. Fharm. Iv. 201) gives a flood {)rocess for the detection of
benzene in a mixture of volatile oils, founded on we &cility with which benzene u
converted into nitrobenzene bv nitric acid, and nitrobenzene into phenylamine 1^
reducing agents. The liquid to oe examined is warmed in a test-tube with fuming ni^
acid, diluted with water, and shaken up with ether, which dissolves the nitrobenzeae
The ethereal solution is separated by a pipette, and mixed with equal volnmei d
alcohol and hydrochloric acid, and granulated zinc added. After five minutes, the
mixture is saturated with potash, again shaken up with ether, whidi dissolies the
liberated phenylamine, and the ethereal solution evaporated on a watch-^aas ; the
addition of a drop of hypochlorite of caldum to the residue gives the intense poiplc
colour characteristic of phenylamine.

Subaiitutian-produete of BmxenB,

Bromine dissolves in benzene, fomung compounds in which 1, 2, and 3 at. H an
respectively replaced by Br.

Bromoheneene. Monobromohenzid, Bromide of phenyl, C*H*Br (Couper,
Ann. Ch. Phys. [3] lii. 309). — The vapour of an equivalent quantity of bromine b
passed into a large flask in which some benzene is heated to boiling; the prodnet »

BENZENE. 543

wuhed with potash, dried, and diatflled ; moat of it paaaes orer ahovt ISC^C. It is a
eolonrieas liquid, wnelKiig like heniene ; it does not solidify at —20^ C. ; its rapoor-
density IB 6*631. It is not decomposed when heated to 200^^ C. with acetate of silver, ov
with a solution of snlphate of silver in strong snlphnric acid. Heated with potassium
in a sealed tnbe>i it explodes ; with sodium, it yields bensene and a crystalline body.
Fuming nitric acid conrerts it into bronundtrobengene, G^^rNO*, a crystalline body
which melts below 90°, and distils undecomposed. Fuming solphuric acid dissolyes it,
lonBing bramomUpkopktf^ie acid,

Dibromobenxene, BibromobetufitL C'H^Br' (Couper, loe. eit.) — When mono*
bramobensene is acted on for some time by excess of bromine, hydrobromic acid ui
cTolTed, and oystals separate, which, by redystallisation from ether, are obtained in
lai^ oblique prisms, which melt at 89^ C. and boil at 219^ without decomposition.

Tribromobenxene. Ttrbromoberuid. CH'Br' (Mitscherlich (1836), Popg.
Ann. zzxT.*374. Lassaigne, Ber. seient. t. 360). — ^A miztmre of bensene and bromme
exposed to sunlight gradoally forms a solid czystalline body, which is purified by
washing wiUi boiling ether. This is the hydrobromate of trimrnobensenef C'H^r' »
C*H^Br'.3HBr. It forms a white inodorous tasteless powder, insoluble in water,
sparin^y soluble in boiling alcohol or ether, whence it crystallises in microscopic
obliqiie rhombic prisms. It is ftisible, and crystallises on cooling. When heated, it
partly sublimes undecomposed, and is partly resolved into tribromobenzene, hydro-
bromie acid, bromine, and hydro^^en. Heated with hydrate of calcium, it yields tri-
bromoiensmu* This compound is best obtained hj boiling the hydrobromate with
alcoholic potash, adding water, dissolyinff the precipitated oil in ether, andeyaporatine
the solution ; it forms silky, very fusible needles, soluble in alcohol and etner, imd
volatile without decomposition.

MonoekloTobeneene, See PHBrrz^ Chlobids or.

Tricklorobsnsene. Cklorobetuid, G*HK)1' (Mitseherlieh, ^.mY. Piligot,
Ann. €3u Phys. [2] IvL 66. Laurent, ibid, bdiL 27). — The action of chlorine in
sunshine upon bensene is similar to that of bromine, resulting in the formation of
crystals of kydroekloraU of trichlorobeMme^ CfHHJl* - G«H*a>.8HGl, which are
washed with ether or reciystallised from boiling alcohol. It forms colourless shining
}iiTn\f*mk or ihombic prisms with tnmcated lateral edges, insoluble in water, soluble in
alcohol or ether: meltsatl32<^C. f Mitscherlich ^; 136^— UO^^ (Laurent); distils
completelv at 288^, with partial ciecomposition, without leaving any residue. In its
decompositions, it resembks the corresponding bromine compound. Trichlorobenzene
is obtained by the repeated distillation of the hydrochlorate alone (M i tscherli eh) ;
or by heating it with hydrate of barium or calcium, washing the distillate with water,
and zvcti^riiig it over chloride of calcium; or by boiling it with alcoholic potssh
(Laurent). It is a colourless oil, of specific gravity 1*467 at 7° C. ; boils at 210^;
vapovr-densiij 6*37 ; insoluble in water, soluble in alcohol, ether, or bensene. It is
not attacked uj ehkrine, bromine, acids, or alkalis.

ChloTodinitrob$n9€%e, See Cmx>BiDB or DDnTBOPBnnx, under Phkttl,
Cbixxbids or*

UTitrobengene. Nitrobetufol. NUrobensid. C^*NO* (Mitscherlich (1834),
PogK. Ann. xzzL 626). — ^Formed by the action of Aiming nitnc acid on bensene, or by
thecbcy distillation ctf nitrobenxoates. Prepared by gra&ally adding benzene to warm
fuming nitric add ; the nitrobensene separates as an oil on cooli^ is washed with
wator, and rectified over chloride of calcium. It is a jeOowish liquid, with a ve^
sweet taste, and a sm^ like bitter-almond oil; specific gravity 1'1866 at 14^40.
(Kopp); boiIsat218°C. (Mitscherlich), 2190— 220O(Kopp); vapour-densitv 4*4.
Below 3^ C. it oystallises in needles. It is insoluble in water, readily soluble in
alcohol and ether. It is much used hr perihmers, under the name of Essence de war'
borne. It is not attacked either by chlorine or bromine at the ordinary temperatore ;
hot its vapour is decomposed when passed with chlorine through a red-hot tube, yield-
ing hydrochloric acid. Fuming nitric acid dissolves it, and on heating converts it
into dinitrobenzene. Stiong sulphuric acid dissolves it> and on heating decomposes
it, fiximing a daik-coloured solution, and evolving solphiurous anhydnde. Dilute
nitrie or sulphuric acid does not attadc it, even at 100^ Cf. It is scarify attacked by
boiling with aqueous potash or ammonia, or by distillation over caustic lime ; when
boOed with alcoholic potash, it TJf^^ azoxvbenzide (]>. 479) ; and when distilled with
aleohoHc potash, asobenzide. When a solution of nitrobenzene in alcohol is mixed
with ^mmnniA, and saturated with sulphuretted hydrogen, snlphur is deposited, and the
prodoct, when cooled to 0^ C, solidifies to a mass of yellow needles, wnich are soluble
in water or alcohol and have a biting taste ; on driving off the alcohol by heat, more
sulphur is deposited, and phenylamine is finally left :

CTI»NO« + 3H«S - C^H^N + 2HK) + SF.

544 BENZHYDRAMIDE — BENZIDINE.

Other rednemg agente, e.ff. zinc with a mixtare of alcohol axkd hydiodilarie add,
iron filing and acetic acid, and aisenite of potaaainm, convert nitrobensene into
phenylamine.

Dinitrobefizene, (>H*N«0« « C^*(NO«)« (Deyille (1841), Ann. CLPbjK
[3] iii. 187. Muspratt and Hofmann, Ann. Ch. Phann. IviL 214).— Fanned voy
slowly by boUing mtiobenasene with fuming nitric acid ; n^idly when nitrobemene ii
dropped graduallv into a mixture of equal toU. fuming nitric and strong nlphozie
acid as long as solution takes place. The mixture is boiled for some minutes, ud the
crystalline magma which forms on cooling is washed with water and zectyRtallised
from boiling ^cohoL It forms long shining needles or l»inm», which melt bdov
100^ C. and solidify into a radiated mass. It is insoluble in water, soluble in vinn
alcohol Sulphide of ammonium converts it into nitrophenylamine, and sepsntes
sulphur. Zinc and hydrochloric add conyert it into nitroaophenylin (g. v.) Aeeord-
ing to Hilkenkamp (Ann, Ch. Pharm xcv. 86), sulphite of ammoninm eQn?erts
it into a peculiar add, ditkiobengolie or phen$fldinUphodiamie acid^ CH'N'S'O'. He
obtained this compound by the action of sulphite of ammonium on nitzobeuKne, as
follows ; but he attributes its formation to the presence of dinitrobenzene. He hested
80 grms. nitrobensene with 240 grms dry sulphite of ammonium, 1 litre absdate aleoko],
and some carbonate of ammonium, for 8 or 10 hours on a water-bath. The Uqiud vai
filtered from the sulphate of ammonium which separated on cooling, and evaponted to
a syrup, when it deposited at first abundance of fine white lamina^ whidi qniddy
decomposed, and then a smaller quantity of hard needles^ which are the ammomiim-
salt of this add.

Cm*^H>* + 6S0«N«H» - C«H»N«S*0« + 4S0«N«H» + 4NH".
Dlnitrobenteoe. Dlthiobeosolle

add.

It is readily soluble in water or dilute alcohol, slightly in absolute alcohol, insohlile
in ether. Nitric add colours its solution yellow ; chlorine forms with it abnndanee
of chloranil, with traces of a brown resinous substance. The barium-salt ib cxys>
talline, soluble in water, insoluble in alcohol. The add has not been obtained in the
fiee state. F. T. C

BBHUtVlMftABKZBa. Hydride of Cyanaedbemoyl. C"H^*NK) (Lanrent,
Ann. Ch. Phys. [2] Ixvi. 180; Laurent and Qerhardt, Oompt Chim. 1850, 114).
— ^A product of the action of ammonia on crude bitter-almond oil ; or of cyanide of
ammonium on hydride of benzoyl.

SCH'O + NH*CN - C«H"NK> + 2HK).

Crude bitter- almond oil heated to 100^ C, is saturated with dry ammonia, tad die
product dissolved in ether-alcohol : after twenty-four hours, the solution begim to
deposit crystals, which go on increasing for three or fbur days. The mother-Iiqiiarifl
decanted, and the ciycSals treated wiui boiling alcohol, which leaves a white iwdne,
beneoylaroUde, The solution, on spontaneous eva^ration, deposits small needles, mixed
with drops of oil : these are washed quickly with a little ether-alcohol, and reeryi-
talUsed from boiling alcohoL It is also formed in the process for the preparation of
azobenzoyl {q, v.)

Benahydnmide forms colourless, microscopic, rectangular prisms, with two taminal
faces intersecting at an obtuse an^le. It is insoluble in water, sparingly sdbible in edd
alcohol, readily in hot alcohol or in ether. It is very fusible, and soBdifies on coding
to a resinous mass, without decomposition : when farther heated, it gives off hjdro-
cyanic add, and yields an oil, a crystalline sublimate, and a little carbon. It is not
decomposed by cold dilute hydrochloric add ; but, on boiling, it yields hvdride of
benzoyl, hydrocyanic add, and chloride of ammonium. f . T. C.

n AWZSSa Syn. with Bbnzdcidb {q. tr.)
WOIi. snunnDBOUCO AOIB. Bochleder and Hlasiweti gave
the name of benzhydrol to a camphor obtained by them from oil of cassia. Fmtber
investigation by Bochleder and Scnwarz, has shown that this camphor contains tvo
substances, one richer in hydrogen, the other in oxygen : they call the former benz^
drolf the latter, henzhydrolio cund, F. T. C

Syn. with Phbnylaiomb (;. v.)

C»«H»«N» - N^.C^fcH* (Zinin, J. pr. CHiem. xxxvi. 98 ; WL
173 ; Ann. Ch. Pharm. Ixxxv. 828.)— An organic alkali formed by the redaction of
azobenzene or azoxybenzene. It is obtained b^ saturating with sulphuretted hydrogen
a solution of azobenzene in alcoholic ammonia : the liquid toms brown, and, ▼hen
heated, deposits sulphur abundantly, which is filtered off The filtrate, on cooling,
deposits crystals of benzidine, which are purified by dissolving them in boiling alcohol

B£kziDINE-.B£NZIL. 515

tddiag difaite solpihiirie acid as long as a precipitate formB, washing the precipitate with
alooh<3, and diflWMTUiff it in boiling agneoos ammonia : the solution, on cooling, deposits
tM>wn<linA in white ■*»ning scalcs. When an alcoholic solntion of azobenseue or asoxy-
bemene is treated with snlphnroos acid, sulphate of benzidine is at once precipitated.

HM»«»*ii«<i is inodonyos ; scaioelj soluble in cold water, readily in hot water, alcohol,
oretiier ; its solution has a bitter burning taste. It melts at 108° C, and cools to a
OTBtaDine mass : further heated, it partly sublimes, and is partly decomposed. When
t loliition of bemtidine, or its salts, is treated with chlorine, it becomes first blue, then
dizk brown, and deposits scarlet ciystals, scarcely soluble in water, more readily in
ateobol (probably aaobenzene). Nitrous fames attack it Tiolently at a gentle heat>
and eooTert it into asobencene (Noble). It is decomposed by strong nitnc acid.

Bensidine combines with adds, forming definite salts, which are mostly readily
mteUiBaUe : their soluti(»s are predpitsted by caustic alkalis or alkaline carbonates.
The J^droeUorate, C*'H*^^2HC1, crystallises in white, pearly, rhombic prisms,
lohhle in water or alcohol, almost insoluble in ether. llie ehloroplatinate,
G^'^.2PtCl'H, is a yellow ciystalline precipitate, obtained by adding dichloride of
plirinnm to Uie aqueous or alcoholic solution of the foregoing salt. It is slightly
nhhle in water, insoluble in alcohol or ether. When boiled with water (more readily
with alcohol or ether), it is converted into a dark-Tiolet powder. The nitrate forms
wiftsngnlar prisms, soluble in water. The acid oxalate, C*'H'^N*.CK)^H', forms
irfaite, silky, radiated needles, aliffhtly soluble in water or alcohoL The acid sulphattf
(?'WJS*Bb*E*t separates as a dull white powder, when sulphuric add ia added to a
solation of benzidine : from a very dilute solution it separates in crystals. It is scarcely
nhble in boiling water or alcohol. The beturoaie, acetatey tartrate, and phosphate are
an oyatalline/witli mercuric chloride^ benzidine forms a crystalline double-salt,
lohibfe in water and alcohoL F. T. C.

DietMbensidine, C^-H-N* - N».C>«H»". (C«H*)«.H»,— Thehydriodate of this base.
(?«H*#.(HI)», or iodide of dietkyl-beneidamnunnum [N« (C"H«)''(C»H»)«.H*].P, is
obtained m crystals bj digesting benzidine with alcohol and iodide of ethyl, in a
•ealed tube at 1(KP C. for two hours. Treated with anunonia, it yields the free
baae, which unites with adds forming well crystallised salts. The chlofoplatinate,
G>*H"a'. iPtCl* is sparingly soluble. (P. W. Hofmann, Fxoc Boy. Soc xr. 6S6 ;
Ana. Ch. Fhum. cxt. 362.)

TetretJ^lbefuidine, C»H"N« - N'.(C><H*)".(G^»)«, is obtained as a hydriodate by
tnating the diethylAted base with iodide of ethyL The free base mdts at 83° C. re-
aolidififis at 800, and forma crystalline salts with adds. Iodide of ethyl acts but
aloirtT on it, iHit when treated with iodide of methyl, attacks it with energy, forming :

Iodide of DimetJ^tetreihyt-benndammanium, C»H*«N*P - [N'.(C"H*)".(CH*)<.
(CH^J*. This salt dissolves sparingly in alcohol, but easily in boiling water,
vhenee it crystallises in lon^ beautiful needles. Its solution is not predpitated by
ammonia^ but yidds with oxide of silver, a strongly alkaline solution containing the
kjdiate N\C»^)'-(C«H»)\Cg)«|QI, ^^ ^^^ ^^^ ^^^^ ^^ ^^ forming

beantiftiny oystalline salts. The cAhnwlaHnaU CPH*«N*Cl*.2PtCl*, is almost in-
soluble in water, \mt dissolves sparingly in boiling hydrochloric add, whence it
QTatalliaes on cooling in beautifid needles. (P. W. Hofmann, loc, cit.)

maanOm Sousoxide de 8tabhe, C'^HMO", (Laurent Ann. Ch. Phys. [2] lix.
402. Liebig. Ann. Ch. Phann. xxv. 26. Zinin, Ann. Ch. Pharm. xxxiv. 190.
Gregory, GiMupL Chim. 1846. 308.)---Formed by the action of oxidising agents on
hoBoin. Laurent prepares it by passing chlorine over fused benzoin as long as hydro-
cblocie add is evdhreo, and crystallising the product from hot alcohol. Zinin heats
gmtly 1 pt. benzoin with 2 pts« concentreted nitric add ; the reaction is complete when
no mote nitrous lumes are evolved, and when the yellow oil which rises to Uie surface
it qmte dear. This oil solidiflee to pure benzil on cooline.

It crystallises by spontaneous evaporation of its alcoholic or ethereal solution in long
TeUoviah six^mded prisms, which are conunonly hollow. Observed fiices, ao P . oP . F.
It ia without smell or taste, insoluble in water, soluble in alcohol, ether, and warm sul-
pbnric acid, and repredpitated from the last by water. It fuses between 90^ and 92^ C.
and solidifies to a fibrous mass : at a higher temperature, it volatiUsefe undecomposed.

It buns with a red sooty fiame. It is not altered by boiling with nitric add or
with aqueous potash : but when boiled with alcoholic potash, it turns blue and forms
l^cndlie add. With ammonia^ an alcoholic solution of benzil forms various products,
■^cording to the concentration and the duration of the reaction (see Azobsnzil,
BnmuMi BxKzcLiM, Imabenzil). With sulphuretted hydrogen, it deposits sulphur,
and fcrms a yellow oil, smelling of garlic : this oil is more readily obtained by dis-
tilling benzil with alcoholic sulf^ide of ammonium. With sulphide of ammonium, it

Vol. L N N

{

546 BENZILAM— BENZlilM.

yields two or three different prodacts, among which is hjfdrobentU (a, ft.) Fused irith
potassium, it gives off yiolet TaponrB and leayes a carbonaoeons ieBiaTi&

Benzil is polymeric with the nypothetical radide benzol, CHK).

HydroeyanaU of BenzU. C»«H>*N»0» - C"H"0«,2HCy (Zinin).— "When beadl
is dissolveid in boiling alcohol, and an equal weight of nearly anhyonms pnueie add
is added, the mixture gradually deposits white shining rhombic tables of hydzocjuate
of benzil. This compound melts and decomposes when heated, leaTing pore beuO.
It is not attacked when boiled with water or strong hydrochloric add: whenheifad
with nitric acid or ammonifli, it yields benziL Its alcoholic solution giyes irith nitnte
of silrer a precipitate of cyanide of silver, and bensil crystalUses ficom the nhitaoiL
When its alcoholic solution is heated with mercuric oxLde^ mercoiy is reduced, and the
smell of benzoic ether becomes distinctly perceptible. F. T. GL

BaVKZ&AME. 0>«HW. rLaurent^ Bev. sdent zix. 443.)— Fonned, togeliher
with imabeiizil and benzilim, by the action of ammonia on benziL It is best pre-
pared by dissolving imabenzil or benzilim in sulphuric acid, and adding viter,
when an oil separates out which speedily solidifies : this is washed with water ind
a little alcohol^ and crystallised from ether-aloohoL It fonns ooloorless riwaifaie
prisms readily soluble in alcohol or ether. It melts at 105^ C. : if imperfectly fond,
it quickly crystallises on cooling, but if perfectly fused, it solidifies mu^ more dowly,
without ciystcdlisation. It is volatile without decomposition. Boiling aboblie
potash hss no action upnon it: nitric acid decomposes it, yielding an oil which erjital'
tises on coob'ng, and is insoluble in ether : it is soluble in sulphuric add, and is resre-
cipitated by water. F. T. G.

BHHXZI20 ACZD. StUbui Acid, C^<H>*0'. (Liebig [18381 Ann. Ch. Fhsim.
zzv. 25. Zizin, ibid, ttti. 329.) — Formed by the action of alkalis on beanl or
benzoin. Benzil is dissolved in boiling alcoholic potash, in such qoantity that the
solution remains distinctly alkaline, and the whole is boiled until a sample of it girn
no turbidity when mixed with water. The solution is then evaporated to diynen ob
the water*bath, the residue powdered, and exposed to an atmosphere of eaibonie anhy-
dride till all the potash is converted into carbonate ; it is then extracted with alcohol,
the solution mixed with water, and, after distilling off the alcohol, decolorised vi&
animal charcoal, and evaporated to crystallisation. The potassic benzilate thus ob-
tained is redissolved in water, and mixed with boiling dilute hydrochlozie add: oo
cooling, benzilie acid crystallises out.

It forms hard, shining, colourless needles, which are sparingly soluble in cold, more
readily in hot water, easily in alcohol or ether. It has no smell, a bitter metallic
taste, and a strong acid reaction. It melts at 120^ C. ; when heated more stronely,
it turns red, and emits violet vapours which condense to a brown-red oily hqaidl *
residue of carbon being left This oil is volatile, insoluble in water, solnble vith a
red colour in alcohol or ether : the solution is not decolorised by water, or by hydro-
chloric or sulphuric add, but it is decolorised by potash, ammonia, or nitiic add
Benzilie acid bums with a very smokv flame. With sf2t>ng sulphurie acid all
benzilates give a fine crimson colour, which is not easily destroyed by neat disupean
on adding water, but reappears on evaporation. It dissolves in warm nitiic acra, and
is precipitated unchanged by wat<er. Pentachloride of phosphorus conveits it into
chlorobenzil.

BengilaU9,—T)itAr general formula is C>*H*iMO*. The lead-saU is obtabed hj
adding the aqueous acid to neutral acetate of lead. It is a white powder, aligiit^
soluble in hot water : it is unalterable at 100^ G^ Imt when strondiy heated melts to a
red liquid, and emits violet vapours. The potasstMrn-saU forms o^uriesS) transpanot.
anhydrous crystals, readily soluble in wat^ and alcohol, insoluble in ether. It meUs
at 200 ^0., and solidifies on oooUng : heated more stron^y, it deoomposes, yielding &
colourless oily distillate, smelling like naphthiJine, insoluble in water, sohiUe in
alcohol ; the residue contains carbon and potassic carbonate* The silveftcU is a
white, crystalline powder, obtained by precipitating nitrate of silver by thepotasEiiim-
salt. It is slightly soluble in hot water ; at 100^ C. it turns blue, without losing wd^
and melts when farther heated, emitting violet Vapours and leaving metallic dher.

F. T. C

BnntUBK. BengUinade, C"H"NK)' (Laurent [1845], I^-8<»«o^^^
— One of the products of the actioti of ammonia on benziL It is most easily obtaiaed
pure by dissolving imabenzil in boiling alcoholic potash, and adding water to the
solution. It forms white, siUcy, very fine needles, sparingly soluble in alcohol or
ether. It melts at 130^ 0. and solidifies slowly in cooling to an amorphous masi It
distils apparently undeoomposed, but the distillate is readily soluble in ether, and
crystallises from it in needles. It is not attacked by boiling potash or \s hydioeUoniB
acid : warm nitric acid attacks it, evolving red fhmes, and yielding a yeuow oili vhieb

BENZIMIC ACID— BENZOERETIC ACID. 547

crjstallifles on cooling, and is insoluble in ammonia, but soluble and ciystallisablo
from ether. It diasolTefl in warm sulphuric acid, and the addition of water separates
bennlim. F. T. C.

■■■MMIO AjCXM^ (Laurent, Compt Chim. i 37.) — The name given by
Lanzent to a peculiar acid which is formed in the preparation of amarine (q, v.) It
is best prepared bj saturating an alcoholic solution of bitter-almond oil with ammonia,
letting it stand for 48 hours, and adding water, which takes up benzimate of ammo-
nium. The addition of hjr^ochloric acid to the aqueous solution precipitates the
acid, which is purified by dissolyinff it in alcohol oontaining ammonia, ooiling the
Bofaition, and neutralising with hydrochloric acid. It forms white silky needles,
insoluble in water slightly soluble in alcohol : it melts when heated, and cannot be
dutiUed undecompoeed. It has not been analysed. F. T. C.

BSnnmiB. Betuhydrocyanide, Hydride of Qyanobenzoyl, C"H**N'0*.
(Xanrent (1836), Ann. Ch. Phys. [2] lix. 397: brri. 193; ReT. scient x. 120.
Zinin, Ann. Ch. Pharm. zzziy. 188. Gregory ibid. liv. 372. Laurent and
Gerhardt, Compt. chim. 1860, 116.) — ^Formed by the action of hydrocyanic add on
h jdzide o€ benzoyl :

8C^"0 + 2CNH e. C«»H»«N»0« + H»0.

Hydride of benzoyl mixed with } its volume of nearly anhydrous prussic acid is
shaken up with an equal volume of strong alcoholic potaah diluted with 6 pta. alcohol,
and the whole gently heated : after a time a white curdy precipitate separates, which
is boiled with water, and purified by solution in alcohol Benzimide also occurs,
mixed with hydride of benzoyl and benzoin, in the resinous residue of the rectification
of oil of bitter-almonds : it may be extracted by treating the residue with hot alcohol.
Benzimide forms a light loosely-coherent mass, white, with a greenish tinge, and
leaves a stain when rubb(Bd or pressed. It iz insoluble in water, or in cold potash or
hydrochloric acid ; sparingly soluble in boiling alcohol or ether. When heated, it melts,
and finally volatilizes with decompoeition, leaving a carbonaceous residue. It dissolves
in strong sulphuric add with a green colour, which soon changes to led, and is re-
preeipitBted dt water. Nitric acid dissolves it with decomposition : heated with nitric
acid and alconol, it evolves red Amies and yields ammonia and benzoate of ethyl.
Boiled with hydrochloric add, it yields hydride of benzoyl, sal-ammoniac, and probably
alsofixrmie acid.

C«H'*N«0« + 6HK) w ZCTEH) + 2CHH)« + 2NH».

Heated with strong bases, it yields benzene ; and with potassic hydrate moistened with
alcohol, it fizrms ammonia and potassic benzoate. F. T. C.

Syn. with Bjutzjuva (^. v.)
CO AVBT9BXII& See Acsnc Anhtdbidv.

See Benzoic Amnmnina.
Bbnzoatb of PHKfTL. See Bsnzoxc Acn>.

J,C"H"C10» (Berthelot, Ann. Ch. Phys. r3]xli. 302).

, One of Berthelot's artificial fats, containing the dements of benzoic and hydrochloric

adds and glycerin, minus water :

C'H«0« + Ha + C»H»0* - C»H»aO« + 2H*0.

It is prepared by saturating with hydrochloric add gas a mixture of glycerin and
benzoic add, which is kept for several hours at 100^ C, and removing the excess of add
bj sodic carbonate : the benzochloxhydrin then sinks to the bottom as an oily liquid.
When pore, it is a neutral oil, solidifying at —40^. It is decomposed by potash,
yielding potasnc chloride and benzoate : and by hydrochloric add and alcohol, yield-
uig glycerine and benzoate of ethvL The chlorine is not withdrawn from the
eompoond even by long digestion at 1 00^ with oxide of silver. F. T. C.

. See Bbmzoic Anhtmubb,
See BsNtoic Ahhvbbidb.
!• See BxNZAMiDi,
Syn. with ToluoL See Bbnztl, HtnuDB of.

Amorphous beruSoio acid, Parahenzoic acid (E.Kopp.
Compt. chim. 1849, 164). — An amorphous powder, obtained by heating gum-benzoin
with 0 or 8 pts. nitric add, not s^ng enough to form nitrobenzoic acid. When
quite pure^ it is white ; but it is commoiHy yellowish, owing to the presence of a small
quantity of a yellow redn, which accompanies it into all its compounds. It is readily
aohilde in alcohol, ether, and boiling water. It has an aromatic, faintly sour and
bitter taste. It melts at 1 13^ C, boils at 266^, and by diy distillation yields pure crys-

K N 2

548 BENZOGLYCOLLIC ACID.

talllne benzoic add, and, if not quite poio, a slight carbonaeeoiia lesidiie. When
ffentlj heated, or exposed to the snn, it beoomea ooTered with small ayBtals of
benzoic add. Distilled with lime, it yidds benzene. It foims salts which oTstalliae
with difficultj, and are generally less soluble than the oonesponduig beiwoalMi.
Different specimens haye ridded different results to anatysis : bat in some oases the
composition is yeiy near that of benzoic add. F T. C.

BB»XOa&TCM»&ldO AOUK CfHH)«»(OiHH))''.C'HK>.KO*(Strecker [184r|,
Ann. Ch. Fharm. Ixyiii 64. StreckerandSocolof^ tMdlxxx. 18. G-ossman, iiiuL
zc 181; zd. 869). — Formed by the action of nitrons anhydride on hif^yaiie add:

2C»H»N0« + NK)» - 2C"HH)« + N« + H«0.

It IB prepared by nibbing hippnric add to a thin paste with strong nitric add, and
passing k current of nitnc oxide into the mixtoie : nitrogen is then eyolyed* and the
hippnnc acid gradually dissolyed. After some time, the ckar solution becomes omit^ue
from the deposition of benzoglycollic add : the current of gu is kept im until the
liquid assumes a greenish colour, when a large ^uantil^ of water is adde^ ana the whole
allowed to cooL The add then separates out m considerable quantities ; it is ocdlected
on a filter, washed with cold water, suspended in water, neutralised with milk of lime, and
the resulting caldum-salt is purified by recrystalHsation and pressure between paper, and
subsequently decomposed b^ hydrochloric add (Socoloff and Strecker). It may also
be prepared by slowly passing chlorine into a solution of hippuric add in excess of
moderately dilute potash : when the eyolution of nitrogen ceases, the miztore is
careAilly neutralised by hydrochloric add, concentrated by gentle eyaporation, and
mixed with a slight excess of hydrochloric add, when it soUdiftes to a oystalline mass.
This is purified by solution in ether, and distilling off the ether from the watery layer
bdow it, when the acid separates as an oil in the midst of the water (G'08sman)L
The acid obtained by either of these methods generally contains a hu^ qaanti^
of benzoic add, which is remored by partially neutralising the add with milk of
Hme and eyaporating to dryness : benzoic add, being the weaker add of the two^
remains uncombined, and is extracted from the reddue by ether.

Benzoglycollic add cxystallises from alcohol in colourless prisms of 37^ 40* and
142^ 2C^, which often take the form of thin plates : when predpitated by acids fiom
aqueous solutions of its salts, it separates as a white crystalline powder. It is seaivel^
soluble in cold, more so in hot water, readily in alcohol and ether : it melts in hot
water before dissolyin^. It mdts when heated and solidifies to a crystalline mass ;
heated more strongly, it giyes off yapours containing benzoic add, and leayes a slight
residue of carbon. When boiled for some time with water, it is gradually deoon^iosed
into benzoic and glycollic adds :

C»H«0* + H«0 - CTI«0» + (?H*0«.

This deoompodtion is aocderated by the presence of a mineral add.

Bhnzoqltooixatbs are mostly aystalline, soluble in water, some of them in alcohol
also. They are neutral to litmus, and haye a faint but peculiar taste. Their aqueous
solutions may be boiled and eyen eyaporated to dryness without deoompodtion. fSrom
most of their solutions strong adds separate benzoglycollic add as a oystalline powder.
The acid being monobade, their eeneral formula is C*HTMO^

The Ammamum'Sidt is obtained. 1^ saturatang the add with ammonia, or deoompos-
ingthe caldum-salt with Munonic carbonate. It loses ammonia when eyaporated.

The Bariun^ali, C*H^BaO* + Aq, forms delicate silky needles, which lose their
water at lOO® C.

The Caieium-salt, CHTCaO* + Aq, forms delicate silky needles, united in groim^
which lose thdr water at 120° C. It dissolyes in 42*3 pts. cold, and 7-64 pts. boiling
water. It possesses in a remarkable degree the property of forming supezsatoratea
solutions, so that a solution saturated at boiling heat frequently takes some days to
deposit all its crystals in saccessiye crops. Wh^i a strong solution of this salt is eya-
porated with chloride of caldum to a syrupy consistence, a double salt separates out
on cooling in octahedronS) which are permanent in the air, but are deoom.po8ed by
water or alcohol into benzoglycollate and chloride of caldum.

The Copper-salt crystallises on cooling in abundant blue rhombic tablea, when a
boiling saturated solution of the calcium-salt is mixed with nitrate of copper. It
becomes preen and opaque at 100° C, but retains its lustre ; is scarody soluble in eold,
more so in hot, water.

The Fertui salt, 2Fe«0».3C»;H»*0' + 28Aq) or 3(/«0.2C«HyeO«) + Aq, is a ^foI«-
minous fiesh-eoloured predpitate, insoluble in water, which becomes darker 'Vhen
dried After drying in the air, it loses 27*36 per cent (28 at) water at 100° C.

There appear to be at least two basic Lead-salts beddes the normal one. When «
cold solution of benzoglycollate of calcium is mixed with normal acetate of lead, m

BENZOHELICIN— BENZOIC ACID. 549

flocenlent predpitote is formed, which is a mixhiTe of several salta. If this be
disaolTed in cold water, the solution, on spontaneous eraporation, yields, first, crystals
of the salt 6, and subsequently soft starry crystals of the normal salt C*H'PbO^ which
melt with partial decomposition at 100^ C.

b, 4CH'FbO*.PbK) + 3Aq, fozma hemispherical groups of eiystals, which melt at
100^, and lose 1) at water.

e. 2G*H'Fb0^6PbK> + 2Aa.— When the cold solution of the calcium-salt is mixed
with basic acetate of lead, and the^irecipitate digested in cold water and filtered, this
sah cxystallises after some days. It loses 1 at. water at 100° C.

The precipitate obtained by adding the calcium-salt to a boiling solution of normal
aeetate of lead, is a mixture of several basic salts.

The MagneaiuM 9alt forms long, yezy slender needles, readily soluble in water and
akohoL

The l^tetstum- and Sodium-Mlis are obtained like the ammonium-salt The former
crystalliBes with difficulty,^ being yezy soluble. The latter crystallizes more readily
from a hot saturated solution in rhombio tables ; it contains 3 Aq, which it loses at
lOOOC.

The Silwr-salt, CH'AgO^, is obtained as a curdy precipitate when the neutral
ammoninm salt is mixed with nitrate of silver ; this precipitate is washed in cold, and
dissolved in boiling, water, whence it separates in white microscopic crystals, which
when moist quickhr blacken in the light ; when dzy they are not changed at 100° G.

Zinesaltf C^H'ZnO* + 2Aq. A boiling saturated solution of tiie calcium-salt
mixed with chloride of zinc, yields on cooling long thin needles, which are dried by
filter p^>er and reaystallised. They lose 2 at water at 100° C. F. T. 0.

aMnosXUECar. C*"H*K)*. (Piria,Ann.Ch.Phy8.[3]xxxiv.278; xUv.366.)
— The product of the action of the nitric acid on populin. It may be regarded as
h^cin, (C"H»'0'), in which 1 H is rephused by benzoyl, C»H»0« - C»«H»*(C'HH))0'.
It is to populin (benzosalicin) as helicm is to salidn.

Obtamed by dissolving populin in pure nitric acid of specific gravity 1*3, the solu-
tion becomes yellow, and benzohelicin soon crystalliBes out On diluting the mother-
Iif|aor with water, more crystals separate out It forms silky needles doselv resem-
bling faeUein. When boiled with water and magnesia, it is converted into helicin and
benaoieaeid. Synaptaae has no action upon it Acids and alkalis convert it into benzoic
Sfcid, hydiids of saucyl, and ghioose :

a»H«^» + 2HH) - (7H«0« + (?H«0« + C-ffK)*,

Hydride Gluooie.

•aliarl.

F. T. C.

BanOIO AOnia Ftowgr* of Bengom, HvdraU of Beiufoyl, Betufoeblwnen,
BetuoeBoSre. Aside benmnqu^ CrH*0* » C'HH)AO. [or 0*«J9«0« - Cf^*IPOMO.]

Sittory and 8ouroe». — ^First noticed by Blaise de Yigenire (Tratti du feu et du
ael, 1606). Its true composition was determined by Liebig and Wohler (Ann.
C3i. Fharm. iil 249). It occurs ready formed in gum-benzoin, dragon's blood,
8t47rax, Peru and T<du balsams, and in many other resins and balsams ; Siao in casto-
ream (Wohler, Ann. Ch. Pharm. Ixvii 360), in the spindle tree, Euonymua europtBtu,
(Sehweiser, J. pr. Chem. 411, 437), and in the putrefied urine of man and of grami-
nivoroos animals (Liebig, iifid. 1. 168).

Formation. — ^It is formed in a great number of organic reactions. 1. By the oxida-
tion of hydride of benzoyl, even by its exposure to moist air. 2. By the action of
-wvtor on chloride, bromide, or iodide of benzo^L 8. By heating benzylic alcohol with
aqueous chromic acid. 4. By the action of mtric acid on hydride of dnnamyl, dnna-
sue acid, cinnamol, cnmol, and cuminoL 6. By oxidising casein or gelatin with sul-
phuric acid and binoxide of manganese (Guckelberger, Ann. Ch. Phazm. bdv. 80).
6. From hippuric add, by putrefii^tion, or by boilins; with acids or alkalis. 7. By the
action of dilute alkalis on populin. 8. By the diy distillation of insolinic (Hofmann)
and quinic aods (Wohler, Ann. Ch. Pharm. li. 146).

I^nparaHon, — Gum-benzoin is employed for the preparation of benzoic acid on the
laige scale ; the process may be conducted either in the dry or wet way. The best
method ofpreparing it in the dry way, or by sublimation, is that given by M ohr,
Ann. Ch. Pharm. xxix. 177). The coarsely-powdered resin is placed at the bottom of
a. round shallow iron-pot» 8 inches in diameter and 2 inches deep ; the mouth is closed
frj a diaphragm ot coarse filter-paper, closely cemented to the sides of the vessel ; and
^rxet this is tied a covering oi thick paper, in size and shape like a hat The vessel
is then heated gently and slowly on a sand-bath (1 lb. of gum requires 3 or 4 hours).
On removing the paper-cover when the whole is cool, it is fbund lined with a crystalline
ffoblimate of benzoic add. The diaphragm allows the vapours of benzoic acid to pass

NN 3

550 BENZOIC ACID.

through it, purifies them in great measure from empyreumatie products, and pNTcnts
the sublimed acid from fidliug back into the TesseL About 4 per cent add is thu
obtained : if the residue in the iron vessel be broken up and again heated, tiie jieU
may be increased to 12} per cent. The acid prepared by this method, vbieh is on th*
vrhole the best for pharmaceutical purposes, is quite pure, with the oception of tnm
of a TohUile oil, which gives it a smell like that of vanilla^ and on vfaidi its medial
properties depend, at least to some extent. — The extraction of the acid from gnn-
bensoiix may oe effected more completely in the wet way. Scheel e's prooesB (OpoK.
ii. 23) is to mix 2 pts. resin with rather less than 1 pt. quick lime, which u iint
slaked, to digest the mixture for some hours with 20 pta. cold water, and to boil the
whole for half an hour. The solution containing benzoate of caldom is flltend
from the residue, which is then washed with hot water, evaporated to one-haU; and
mixed, with excess of hydrochloric acid ; the benzoic acid which crystallises out on oodiag
is purified by recrystalliBation firom hot water, or by sublimation. If sodie carixmate be
emploved instead of lime, a portion of the resin is apt to be dissolved, which eabm ths
benzoic acid, and cannot be removed without difficulty. Wohler (Ann. Ch. Fbarm.
xlix. 245) gives the following method: — ^Powdered gum-benzoin is dissolTsd hj the
aid of heat in an equal volume of alcohol of 90 — 96 per cent, the hot aolntioii mixed
with fuming hydrochloric acid till the residue begins to be precipitated, and the vhob
distilled as long as its consistency permits ; it is then allowed to cool, and again dis-
tilled with water as lonff as any benzoic ether passes over. The joint distillatei, eon*
taining benzoic ether, alcohol, and hydrochloric acid, are heated with caustic potaih
until Uie ether is entirely decomposed, and the resulting solution of potsssic bemoats
decomposed bv hydrochloric acid. The acid thus obtained precisely resemUis tbat
prepax«d by Mohr's method.

Benzoic acid may also be prepared from hippuric acid by boiling it for half an hour
with strong hydrochloric acid, and washing the product with cold water. Bcosoie
acid is sometimes met with in commerce, which is prepared from the urine of giami-
nivorous animals. The urine is allowed to putrefy, then mixed with milk of lime and
filtered ; and the filtrate is evaporated and precipitated by hydrochloric acid. If the
resulting benzoic acid be colour&d, it is redissolved in thin milk of lime, the whole boiled
with chloride of calcium, hydrochloric acid added, and the precipitate reoystalliMd from
1)oiling water. The acid thus prepared is inferior to and cheaper than that obtained
by sublimation. It always smells of urine, and never has the peculiar smell of the
sublimed acid.

Properties. — Benzoic add crystallises in colourless, transparent^ peaifyneedki er
laminae, which, under tlie magnifying glass, appear to be six-mded prisms. It has no
smell, and a faint but persistent sour and warm taste. It x^dens litmus. It mdfei
at 121 -4<> C. to a colourless liquid of specific gravity 1*0888 (wateiir at 0® berngtakenii
unity), and boils without decomposition at 249*2^ (at 740 nojn. pleasure) (KoppX It
begins to sublime at a much lower temperature, and distila over aonndantfy vith
vapour of water. Its vapour-density is 4*27 (Mitscherlich); the vapoms exote
couffhin^. It dissolves in 200 pts. cold, and in 24 — 30 pts. boihnff water, mudi moR
reaoily in alcohol and ether. Fats and volatile oils dissolve it abundantly. It diasohm
in strong sulphuric acid without decomposition, and is repredpitated ^ wato*. It ii
not attacked by boiling dilute nitric or chromic acid ; and is thna distingniahed fton
cinnamic acid, which, under these circumstances, yields hydride of benzoyj.

DecompontUma. 1. By heat — When vapour of benaoie add is passed throng^ a
red-hot tube filled with fragments of pumice-stone, it is decomposed mto bensone and
carbonic anhydride. The same decomposition takes place at a Lower temperature vbca
1 pt add ia heated in a retort with 6 or 6 pts. ooarselj powdered pumice. If too
much heat be applied, naphthalin and some empyreumatie products are also ftnaed,
and a residue of carbon left (Barreswil and Boudault). If benzoie add be heated
with lime, only benzene passes over, the carbonic anhydride being retained by the line-
Heated in contact with air, benzoic add bums with a bright smoky flame^ aod lem
no residue. 2. Dry chlorine acts upon benzoic add in sunlight, forming a reddiih,
tough, gummy mass, whence potassic carbonate extracts chlorobenzoic add (seebelowX
and leaves a brown-red residue, which smells of benzoin, and contains eUoiue
(Herzog). Brojnine acts on benzoic add in similar a manner. When chlorine
is passed into a hot aqueous solution of benzoic add, or when benzoic add^ ia boiled
with aqueous chloride of Ume, or with potassic chlorate and hydrochloric add, a ouz-
ture of mono-, di-, and tri-chlorobenzoic adds is obtained ; but these adds have not been
separated and examined (Stenhouse, Ann. Ch. Pharm. Iv. 10). When a sohtion of
benzoic acid in excess of potash is saturated with chlorine, diloronicdc add, CH'ClO'i
is produced (St. Evre). 3. When benzoic acid is heated with strong nitrk edi,
nite>benzoic acid is formed : a mixture of sulphuric and fuming nitric acid oonrerta it
into dinitrobenzoic acid. 4. Fuming tttlphuric acid converts it into salphobensoM

BENZOIC ACID. 651

add. 6. Heated to 200^ C. with a mixtore of anhydrous acid sulphate of sodium,
(Na^80*.S0*) and chloride of sodium, it yields chloride of benzoyl together with hydro-
cUoric acid.

C»H«0» + S0« + 2NaCa - C^HXJi + B.CI + Na«SO«.

Tlie neatral sulphate of sodium is associated with the sulphuric anhydride to prevent
the laJtter from converting the benzoic add into sulphobenzoic add (Beketofl^
Ann. Ch. Fharm. dx. 256). 6. Perchloride of phoaphonts does not act upon benzoic
add till heat is applied, when hydrochloric add is evolved, and chlorides of benzoyl
and of phosphozyl formed. 7. In the animal organism, benzoic add is converted into
hijqpuiie add, which is found in the urine. (Wohler, &c)

BnooAiifl. — Benzoic add decomposes carbonates, but an alcoholic solution of
potaasie benzoate is decomposed by carbonic anhydride, potassic carbonate being pre-
cipitated. It is a monobadc add, but forms some add and basic salts. The normal
benaoates are mostly crystallisable, and soluble in water and alcohol. Their aqneous
aohitions are decomposed by almost all adds, benzoic add being predpitated. AUcaline
and alkaline-earthy benzoates yield, by dry distillation, benzene, benzene, solid hydro-
carbons isomoric with naphthalin, and a metallic carbonate. A mixture of benzoate
and formate of potassium yields, when heated, hydride of benzoyl (Piria). With
chloride of phosphozyl, alkaline benzoates yield chloride of benzoyl and a phosphate ;
with chlorioe dT benzoyl, an alkaline chloride and benzoic anhydride. With
perchloride of phosphorus or chloride of sulphur, they yield either chloride of benzoyl
or benzoic anhydride, according to the proportion of benzoate present.

Beneoate of Ammonium, a. Normal, — Obtained in crystals by cooling a solu-
tioD of benzoic add in stronff warm ammonia ; or by evaporating a more dilute solution
with addition of ammonia m>m time to time. It deliquesces in the air, and is soluble
in water and alcohol, but lees so in the latter than the potasdc salt When heated
in a retort» it loses water, and is converted into benao-nitiile. Its solution loses
ammonia on evaporation, yielding: .

6. AM ttdt, — Obtained in large irregular crystals by the spontaneous evaporation of
the solution of a. Less soluble than a in water and alcohol.

B^neoate of Barium^ Cll*BaO* + Aq. — Slender permanent needles (Tromms-
dorf X or large tables, which become opaque at 100^ C. (Plan tamo ur), and lose their
water at WQP (Limpricht).

Ben foaie of Cadmium, CHKidO' •¥ Aq. — By evaporating a solution of carbonate
of i^^mium in aqueous benzoic add, shining aggregated needles are obtained, soluble
in hot water, spanngly in alcohoL (Schif f .)

Bensoaie of Calcium, C^*CaO' + Aq. — Crystallises in feathoy needles or in
grannies, soluble in 29 pts. cold, and in less not water.

Benzoate of Copper. — A hot solution of sulphate of copper ^ves with potassic
bensoate an aggregate of bluish>green needles (Ettling), which are anhydrous
(Mitaeherlic^ It dissolves in warm dilate acetic add, and crystallises thence in
small green needles. It is insoluble in alcohol. By dry distillation it yields benzene,
bensoie add, benzoate of phenyl, and an oil which boils at 260^ C, and, when heated
wiUi snlphnric add, is decomposed into hydrate of phenyl and a solid hydrocarbon,
0*H* : me residue contains salicylate of copper.

Ferric Beneoate, — The normal salt crystallises in yellow needles ftom a solution
of ferric hydrate in aqueous benzoic acid ; it is soluble with decompontion in water
and alcohol, a bade salt being left behind. A still more basic salt is obtained when
a solution of ferric chloride, containing enough ammonia to give it a dark-red colour,
is mixed with an alkaUne benzoate : it is a flesh-coloured predpitate, insoluble in,
and not decomposed by, cold water, and containing 17*5 per cent iron. (Berzelius.)

ferrous Bensoaie czystallises in needles, which effloresce and turn yellow when
esqMsed to the air, and are soluble in water and aloohoL Benzoate of ftmrnnn^wTf! does
not predpitate ferrous salts.

Benzoate of Lead, CTH^PbO' + ) A^. — ^A light emtalline powder, obtained by
predpitating normal lead-salts with potassic benzoate. It melts a little above 100^ C,
and gives off its water (Beorzelius). When digested with basic Acetate of lead, it
flpradnally beeomes heavy and granular, being converted into a compound of bane
beaaoate and acetate of lead (Varrentrapp). A bade salt» CrH^PbO*-PbH), is
obtained by digesting the normal salt with ammonia^ or predpitating benzoate of
ammonium with sub-acetate of lead.

Beneoate of Magnesium, — Feathery efflorescent crystals, readily soluble in

Manganoue Bensoaie, CH'MnO* + } Aq. — Transparent, colouriess^ permane&t

M N 4

552 BENZOIC ACID.

noecUes, solnble in 20 pts. cold, and in a much smaller quuitity of boiling viter;
oparinglj soluble in alcohol

Mercuric Benzoate. CH'HgO* + i Aq. — A white precipitate, nude 19 of
slender needles; obtained by adding an a&aline benzoate to a solution of eoooHTe
sublimate. It is insoluble in cold, tolerably soluble in hot, vater ; sleohol and ether
decompose it, leaving a basic salt, which may also be obtained by boiling benaoie aeid
with water and excess of mercuric oxide. When treated with ammonia, mercwie
benzoate is conyerted into ammonUhmercuric benzoate, a white powder, iuokUe in
water, almost insoluble in alcohol or ether; potash turns it TeUow, and jJimin^tn^
ammonia : it contains 69*92 per cent mercuric oxide. (Harf£)

Mercurous Benzoate, (TH'HgH)'. — A bulky ciyBtalline precipitate, ooDnitiiig
of slender needles ; insoluble in cold water ; decomposed bv boUiog water or alooliol,
with separation of metallic mercury. Becomes light-yellow when exposed to tb
light IVeated with ammonia, it is converted into a black powder, containing 8(H)
per cent mercurous oxide.

. Benzoate of Potassium, a. Normal, C^'KO* + Aq. — dystallises with difli-
culty from an aqueous solution, more easily from hot alcohol, in featheiy needles or
pearly laminos. It is vexy scduble in water, has a shaip burning taste, and at 100° (X
loses its water. Heated with arsenious hydrid'e, it yields benzene. (Darcet)

b. Acid salt, CH^KO* + C^*0'. — Formed in the preparation of acetic aohydride
from chloride of benzoyl and acetate of potassium ; the residue is washed with water,
dried, and dissolved in boiling alcohol, when the add benzoate ayBtaUiaes in peariy
lamins. It is slightly soluble in cold water, or in boiling aloohoL (Gregory.)

Benzoate of Silver, — A white curdy precipitate, obtained by double deeompoeition:
it dissolves in a large quantity of boiling water, and crystalliaes thence in long ahiniog
lamine. When heated^ it melts and swells up, and leaves very white metallie iflTer.
It dissolves in 1-96 pts. alcohol, at 100^ C. (Mitscherlieh.)

Benzoate of Sodium, Efflorescent pointed crystals, soluble in water, ^urin^
in aloohoL

The cobalt', nickd', and zinc-salts are ciystallisable and soluble in water and akohol:
the aluminium'SaU, crystalline, tolerably soluble in water : the Uthium'Salt, jaapr
tallisable, very soluble : the bismutk-, cerium-, tin-, yttrium-, and zireonium^taltt, aie
white precipitates, sparingly soluble in water.

Benzoic Ethbbs. Benzoate of Methyl, Benzoeformester. C«HH)«-C^CH*)0".
(Dumas and Peligot [1835]; Ann. Ch. Phys. [2] Iviii. 50; Malagnti, Hid. [2]
Ixx. 387.) — Formed, according to Scharling, in the dry distillation of toh-babuB.
For its preparation, 2 pts. benzoic acid, 1 pt wood-spirit^ and 2 pts. strong ralpfamie
acid, are distilled togetJier, the residue rednitiUed two or three times with freah wood-
spirit, and the united distillates mixed with water. The impure benzoate of methyl
which is thus precipitated, is washed, dried over chloride of calcium, and rectified
over oxide of lead, that portion which comes over above 198^ C. being ooUected apoit
It may also be prepared by distilling sulphate of methyl with potassic benzoate. It
is a colourless, oily liquid, with a pleasant balsamic smell, insomble in water, sohUe
in alcohol and ether : boils at 198^*5 C. at 761 mm., or at 199°'2 at 746 mm. (Kopp).
Specific gravity 1*10 at 17**, or 1-0876 at 16-3 (Kopp) : vapour-density, hr eiperi-
ment, 4*717. Its vapour, passed throuffh a red-hot tube filled with Ume, yields, unoog
other products, bonzene. it absorbs dilorine without apparent iteration : when the
saturated liquid is heated, hydrochloric acid and chloride of methyl pass over fint,
and then chloride of benzoyl in abundance ; the coloured residue contains bemoie add,
benzoate, and (probably) cnlorobenzoate of methyL

Benzoate of Ethyl. Benzoevinester, C»EP»0* « C'HVC'H')©'. (Scheele, Opmt
iL 141 ; Dumas and BouUay, Ann. Ch. Phys. [2] xxxvui. 20; WohlerandLiebig,
Ann. Ch. Pharm, iii 274 ; Deville, Ann. Ch. Phys. [3] iii. 188.)--Benzoate of ethyl
is not formed by the mere contact of benzoic acid and alcohol, however prolonged; Int
the reaction takes place gradually when the mixture is heated to 100^ C. u a sealed tube,
or when a small quantity of a strong acid is added to it The statements of Deville and
Cahours, that it is formed by the dry distillation of tolu-balsam and gum-benzoin, seem
to require confirmation. It is prepared hj distilling 4 pts. alcohol with 2 pts. benioie
acid, and 1 pt fuming hydrochloric acid, oil two-thirds have passed over, and poviiog
back the distillate into the retort two or three times : a little of the ether pssses over,
but the greater part remains in tiie residue, whence it is smrated by additica of
water. Or a solution of 3 pts. benzoic acid in 2 pts. boiling alcohol of 80 per eent if
heated for some time. Liebig and Wdhler prepare it by dissolving chloride of braao^
in absolute alcohol : heat and hydrochloric acid are evolved, andthe addition of water
separates the ether. The ether prepared by any of these methods, contains sone ftee

BENZOIC ACID. 558

bensoie add, from which it is purified by agitation with Bodic carbonate, washing with
water, and rectification oyer oxide of lead.

Beosoate of ethyl is a colourless oil, with a pleasant aromatic smell, and a pnngent
taste; boils at 212-9^ C, when the barometer stands at 746*6 mm. Specific grayity
1*0566 at l(P-6 C. (Kopp). Vsponrnlensity by experiment, 6*406. It is ui^tly
•olnfale in water, soluble in all proportions in aJoohol and ether. It buns with a bright
smoky flame. Chlorine does not act upon it below 60^ or 70^ C, when hydrochloric
acid and chloride of ethyl pass oyer: on heating the mixture, a colourless distillate
passes oyer at 190^, to which Malaguti (Ann. Gh. Fh^. [2] Ixx. 374), assigns the
formula CH^'d'O*, regarding it as a compound of dilonde of benzoyl with bichloro-
yinie ^her : the black residue, when fhrther heated, yields chloride of benzoyl. Nitric
add, or a mixture of nitric and sulphuric adds, conyerts it into nitrobenzoate of ethyl.
It is not attacked by perchloride of phoephoms (C ahours). When distilled oyer fhsed
chloride of cine, it yields chloride of eth^l and benzoate of zinc, which latter is de-
composed by fiaither heat, forming benzoic acid and benzene. Ammonia acts upon it
slowly, at the ordinarjr temperature ; but, if the mixtore be heatpd aboye 100° C. in a
sealed tube, benzamide is readily formed. Aqueous potash conyerts it yeiy slowly into
alcohol and potassic benzoate : when heated with solid potash or potash-lime, hy-
drogen is eyolyed, and benzoate and acetate of potassium formed (Dumas and Stas).
Sodium acts upon it between 60° and 70° C. : the liquid turns brown, without eyo-
hition of gas, yielding; among other products, the ether of a peculiar add. (See Htpo-

BB2IXOTLOUS AdD.)

Bensoate of Ethylene, Benzoate of Glycol, C»«H"0* = (CB*Oy.{C*R*)\0\
(H. Simpson and Wurtz, Ann. Ch. Fhys. [3] ly. 400.) — Obtained by the action of
dibromid of ethylene on benzoate of silyer. It is soluble in ether, and crystalliBes
from tiie solution in colourless, shining, right-rhombic prisms. Melts at 67° C, and
distila without alteration at a temperatoro aboye the boiling point of mercury.

B^ngoate of Amyl. .C>«H»«0« = C*H»(C»H")0« (Rieckher, (1847), Jahr. pr.
Fharm. xiy. 16V — Obtained by distilling 1 pt. fiisel-oil and 2 pts. sulphuric add witii
ciTCfwn of alk^ine benzoate. It is a ycdlowish oil of peculiar smell : boils at 260*7^ C
when the barometer stands at 746*6 mm. Specific grayity 0*9926 at 14°-4 (Kopp) :
readily decomposed by aloohoUc potash.

BensoateofAllyl BensoepropylenyL C"H»0«=C^»(C«H»)0«(Zinin, Ann.Ch.
Fharm. xevi 362; Cahours and Hofmann, ibid, cii 297; Berthelot and De
Luc a, Ann. Ch. Fhys. [3] xlyiii. 286). — Obtained by diBtilling equal quantities of
iodide of allyl and benzoate of silyer, washing the distillate with sodic carbonate, and
recti^ring oyer oxide of lead. Also by the action of chloride of benzoyl on allylie
aloohoL A ydlow aromatic oil, heayier than water : boils at 230° — 240° C. : insoluble
in water, soluble in alcohol or ether : decomposed by boiling with potash.

BentoateofBengyl BeneoaUof Tolyl (Canizzaro.) C"H»»0»=CrH*(CrH^O».
— When dUoride of benzoyl and benzylic alcohol are distilled together in equal propor-
tions, hydrochloric add is eyolyed, benzoic add and chloride of benzyl pass oyer, and
finally benzoate of benzyl, in the form of a yellowish oU, which crystallises on cooling.
It is purified by pressuro between filter-paper, rectification oyer benzoic anhydride,
waahing with sodic carbonate, and another rectification. It forms colourless crystal-
line l^mi«g»^ which melt below 20° C, and boil at about 346°. Alter fusion, it recrys-
talliscs with great difficulty, often requiring the aid of a freezing mixture. It is isomeric
with benzoin.

Benmoate of GlyeyL See BHMZOioor.

Bengoate of Phenyl. Beneophenid. Bengoeoxyd, Benroearbolie aeid, C^'W^O*^
CrBH(ya*)0*. (Ettling (1846), Ann. Gh. Fharm. liii 87; Stenhouse, Und.lm.
91 ; tiaurent and Gerhardt, ibid. Ixxy. 76; List and Limpricht, ibid. xc. 190.)
— Obtained by the action of chloride of benzoyl on phenylic alcohol or phenylate of
potasdnm : by the dry distillation of benzoate of copper (Ettling) : by heating ben-
maalinrlir anhydride f Gerhardt). List and Limpricht haye shown the identity of
the substances obtainea by all these methods. It is best proparod by heating phenylic
alcohol with chloride of benzoyl, as lon^ as hydrochloric add is eyolyed, washing the
CTTstalline product with potasn, exhausting it with ether-alcohol, and eyaporating the
•olution to crystallisation. To obtain it from benzoate of copper, the dry salt is dis-«
tilled oyer the open fire as long as yapours are eyolyed ; the distillate again distUled
with excess of so<uc carbonate, as long as benzene passes oyer with aqueous yapour ; the
inaohible residue in the retort separated from the alkaline liquid, washed with water,
and diasolyed in hot alcohol ; and the crystals which separate on cooling, purified by
tepeated crystallisation from hot alcohoL (List and Limpricht.)

MQsoate of phenyl forms hard, shining colourless, rhombic prisms, often half an

554 BENZOIC ACID.

inch long. It melts at 66^ C, and cools to a cryRtallme man : at a higher tempentnn
it TolatiHses undecomposed. It has a faint smell of geraniums, or, when heated, of
lemons : is insoluble in water, solable in alcohol and ether, espedaUj on hettiog. It
boms with a red, yery smoky flame. Chlorine and bromine conyeri it into sabetitatiaB-
prodncts (see below). Snlphnric acid dissolyes it readily; the addition of water
separates benzoic acid, while sulphophenylic add remains in solndon. Boilhig hydro-
chloric acid does not attack it. It is not decomposed by boiling with aqueous potaah,
but, if the mixture be heated to 150^ — 170° 0. in a sealed tube, potassic hensoats and
phenylate are formed : the same decomposition is efifected by fiision witii solid potash,
or by contact with alcoholic potash, eyen in the cold. It may be boiled with aboholie
ammonia without decomposition ; if the mixture be heated to 160^ G. in a sealed tobe,
phenylio alcohol and benzamide are formed, but no aniline. It is similarij deoonh
posed when distilled in a stream of dry ammonia. Perchloride of phosphoma dsea not
attack it. (List and Limpricht.)

Stibstiiutum-producta of BerufoaU of Pket^

1, 2, or 8 at H in benzoate of phenyl may be replaced by Br, CI, or KO*. ThcN
substitution-products are obtained either by the direct action of chlorine, bromine, or
nitroeulphunc add, on benzoate of phenyl; or by the action of chloride of benzoyl ob
the substitution-products of hydrate ofphenyL

Benzoate of Bromophenpl, C»«H»BrO»=C'H»(C^*Br)0*, and of Dihromo-
phenyl, C"H"Br»0««C»H*OC*H«Br*)0». BroTno- and Dibromo-bemopheiM. (Liit
and Limpricht, loc. cit.) — ^When dry benzoate of phenyl is treated with bromine as long
as any hydrobromio add is eyolyed, the excess of bromine distilled oS, and the reridBs
repeatedly crystallised from hot alcohol, large colourless needles are obtained, vhieh
melt bebw 100® C, sublime undecomposed, and are insoluble in water, bnt adfiUe in
hot alcohol and ether. From the great yariation in the analyses, this oompomid ii
certainly a mixture of at least two substitution-compounds : and it is probable that
tribromobenzophenide is present also. The substance is dissolyed and decompoaedbj
cold alcoholic potash, into benzoic, bromophenylic, and dibromophenylic acids.

Bengoate of Chlorophenyl. Chlorobenzophemd. C»H»ClO»-CrH»(OTHa)0».
(Stenhouse, loc. cit.) — ^When dry dilorine is led for some days oyer fiised bennate
of phenyl, a dark-yellow mixture is produced, consisting of an oily and a solid body,
haying a yery pungent smell : this is pressed between filter-paper, and the solid reii-
doe repeatedly crystallised from ether. Large flat crystals are thns obtained, vhieh
melt at 84® C, and sublime in four-sided prisms : they haye a faint smdl, like that of
sesquichloride of carbon. From analyses, this substance appears to be a miztnre of
chloro- with dichloro-benzophenide. The oily substance contains more chlorine^ and
probably consists in part of trichlorobenzophenide. Both compounds, when heated vith
alcoholic potash, yield chloride and benzoate of potassium, and on addition of hydro-
chloric add, a dark, resinous body, smelling of creosote, which is probably ii^nze
chlorophenyUo add.

Benzoate of JDinitrophenyl. DinUrobeneopkemde, C'*H»1TO< = (?H»(C^
(N0*)*)0*. (Laurent and Gerhardt, loe, ci^.])— Dinitrophenylic add is heated vilh
chloride of benzoyl, as long as hydrodiloric add is eyolyed ; and the prodoet is ezbaeted
with dilute ammonia, washed with cold alcohol, and crystallised from boiling aloohoL
Yellow rhombic lamina, insoluble in water, dightly soluble in hot alcohol, non
readily in warm ether, partly soluble in potash.

Benzoate of Trinitrophenyl Trimtrobenzophmide, C'H'N'O* « C^*(C^
(NO'^')O'. — ^Prepared like the preceding compound, trinitrophen^h'e (pierie) aeid bciig
substituted for dinitrophenylic acid. Shining yellow rhombic l*min«, leas soluble in ill
menstrua than the ainito>-oompound. 'mien heated, it melts and solidifiei to a
crystalline mass : heated more strongly, it explodes. Dissolyes in boiling potaah, fom*
ing a dark-red solutidn, whence adds precipitate crystalline flakes.

Subsiitutionrproducts of Benzoic Add.

Bboxobemzoio Acid. C»H*BrO«. (P^ligot [1836], Ann. Ch. Fhaim. xxriii 246;
Herzog, N. Br. Arch, xxiii. 16 ; Miiller, Compt rend. xxx. 325.)— Bensdc acid ii
treated with bromine in the sunshine, the excess of bromine Stilled off, the reridne
dissolyed in sodic carbonate (when an oil containing bromine remains undissolTed^
and the solution predpitated by nitric add (Herzog). P^ligot makes bromiM-
yapoor act upon benzoate of silyer, by placing the salt, together with a tube contain-
ing bromine, in a dosed yessel, and leaying it for twenty-four hoars : from the pi^^
the bromobenzoic acid is dissolyed out by ether. The solution, on eyaporation, yieldi
a brown oil, which crystallises on cooling : this is dissolyed in potash, treated to
animal charcoal, and repredpitated by nitric add. It ibrms a colourless oTstalhas

BENZOIC ACID. 555

maflfl, vliich meltfl at 100^ C, and sablimefl at 250^, leaTiflg a residae of carbon. It
bums with a amok j green-edged flame : is sparinglj soluble in water, readily in alcohol
and ether.

Bromobensoaies are genenllr soluble and aTstallisable : the kad-^ copper-, and
nisreurou9-^€Uts are leas solnbie. The niwr-salt, CH^AgBrO*, is soluble in warm

- CHLOBOBBmoio AciD. ChloroTmckmyUc acid. CHKIHO*. (Herzog, 1840, N. Br.
Arch, zxdii^ld ; Scharling, Ann. Ch.Phann.zlL49; xliL268; Stenhou8e,t^.lv. 1;
Field, ibia, her. 65 ; Limpricht and y. Uslar, ^nd. di 259 ; Chiozza, Ann. Ch.
Phja. [3] zzxTL 102). — ^When dry benzoic acid is acted on by chlorine, a moist viscid
reddish mass is formed, which appears to contain a mixture of mono-, bi-, and tri-
cUorobenzoic adds ; these acids (which Stenhouse also obtained by treating benzoic
acid with chloride of Hme and hydrochlorie acid^, cannot be separated from each other.
Limpricht and Uslar obtained pure chlorobenzoic acid from eUoride of chlorobenzoyL
Aeoording to them, the add obtained by Chiozza^ by the action of perchloride of
phoaphoma on salicylic add, is not identical, but isomeric, with chlorobenzoic add :
we BAall describe it separately as parachlorobengoic acid. There is no doubt that the
ehloromichmylic add obtained by Scharling by distilling urine with nitric add, is
identical with chlorobenzoic add.

limpricht and TJslar boil chloride of cUorobenzoyl (obtained by the action of per-
chloride of phosphorus on chlorosulphobenzoic adch with potash, and saturate the
■olnlion with hydrochloric add : the predpitated chlorobenzoic add is purified hj re-
eombination with a base and repredpitation by an add. It forms colourless, concen-
trieaUy-gronped prisms, which melt at about 140^ C, but sublime at a lower tempe-
rature in small needles. It dissolyes sparingly in cold water, readily in hot water,
alcohol, or ether. Fuming nitric add converts it into nitrochlorobenzoic add. The
cMordbienMoaUa are generally soluble. The solution of the ammoniuTnrsdlt gives off
ammonia abundantly when evaporated, so that the residue is nearly pure chlorobenzoic
add. The add which Field obtained by boiling benzoic add with potasdc chlorate and
hydrochloric add, melts with difficulty, and bl^ens when heatecL The barium^ fijxd
ealeium-^alia crystallise with 1} aq., which they lose at 100^ 0. The lead-Bolt is a white
pracipitate, which melts and turns yellow at 110^. The jK>ia8rium' and sodiwn^alts
are nncrystallisable. The tUver-Molt, C'H^AgClO', is a white predpitate, consisting of
microMomc needles. Chloroberutoie ether (chlorobenzoate of ethyl), G*H*C10' «
C*HXCU*)C10', LB obtained by treating the add with alcohol and sulphuric add, or
ehloiride of cfalorobenzoyl with alcohol, and predpitating the product with water. It
18 a ]i<]aid smelling like benzoate of ethyl, and boihng at 246^ Cf. It dissolves in nitro-
culphurie add, and water predpitates fnim the solution an oil which gradually solidifies
into ciyatals^ probably of nitrochlorobenzoic ether.

Parmcklarooenxoie Acid, C'H'CIO' (Chiozza, loc. ci^.)— ^Salicylic add is distilled
with perchloride of phosphorus, and the distillate rectified, when a heavy, strongly re-
frftfCtin^ oil passes over between 200° and 260° C, which is converted gradually by cold,
immediatelv by hot water, into hydrochloric and oarachlorobenzoic adds : the oil is
piobftbly die chloride corresponding to the ado. Parachlorobenzoic add forms
colourless shinhig crystals, like those of salicylic add, from whfth it is distinguished
by giivine no violet colour with ferric salts. It melts at 130° C, and sublimes unde-
composeGT: dissolves readily in hot water, and the saturated solution solidifies on
cooling into a mass of needles. Some of its salts diffbr from the corresponding chloro-
benxoatcs in the amount of water of dystaJUisation which they contain: tiius the
bariun^salt is anhydrous, and the calcivm-ealt contains 1 aq. The eUver-ealt may be
obtained in rather large cxystalB.

NiTBOBBraoic Acid, C'H»N0* « C'H»(NO«)0«. (Plantamour [1839], Ann. Ch.
Pharm. zzx. 349; Mulder, ibid, zzxiv. 297; Abel, tbid.'ba^ 313; Berta^nini,
ibid. Izxiz. 269; Blumenau, ibid. Ixxzvii. 127; Gerland, ibid.xcL 185). Mulder's
method of heating benzoic add with fumine nitric add, is a long process. Gerland
recommends agitating 1 pt. benzoic acid and 2 ^ts. nitre with strong sulphuric add,
and heating the whole tifi it softens : the resulting nitrobenzoic add is purified by
ClyBtallisation from boiling water. The acid is also formed by the decomposition of
several organic compounds : by the oxidation of hydride of nitrobenzoyl by chromic
add (Bertagnini) : by boiling dnnamic add and other dnnamyl-compounds (Plan-
tamour, Mulder), cumene (Abel), or dragon's blood (Blumenau), with nitric
add: by heating nitrohippuric acid with hydrochloric add (Bertagnini). Nitro-
benzoic add forms colourless laminse, generally grouped together. It melts at 127° C.,
VutsubUmes at 110°, and if pure, leaves no residue: the vapours excite ooughino.
"When boiled it blackens and decomposes. It dissolves in 400 pts. water, at 10°,
and in 10 pts. at 100°, forming strongly add solutions; it melts in water below 100°^

556 BENZOIC ACID.

to a heavy oil : is readily soluble in alcohol and ether. Stiong nitric or hydrodiknie
add dissolyeB it without decomposition : but it is deoompoeed hj molooged bofling
with nitric acid. It dissolyes in cold sulphuric add : on heating the solution, some
nitrobenzoie add sublimes, and near the boiling point of solphurie acid the miztan
becomes red, a peculiar compound beinff formed (Mulder). It is not attend W
sublimation in dry chlorine. Perchloride of phosphorus attacks it when hesto^
yielding chlorides of nitrobenzoyl and of phosphoiyL With sulphide of ammomim it
forms benzamic add {g,v.) In the animal system it is conyerted into mtrohippoie
acid, which appears in the urine.

Nitrobenjsoaies are generally oystallisable and soluble in water and alcohol: tluj
explode when heated, and gire off nitrobenzoL Nitrobenzoie add is a stzong add, and
decomposes the salts of many other adds. The normal airnnonium-tttU loses anmoua
when heated, and yields an add salt, which also czystallises when the solution of the
normal salt is evaporated : the normal salt on prolonged fodon, yields mtzobeoBBiide
(Field). The barium-salt C*H^BaNO« + 2aq., forms fine Gnfstals which lose their
water at 100° C. The calciumrsalt contains 1 aq., which it loses at 13(P— ISO^C.
The copper-salt is a blue powder, which separates on cooling from a hot miztnre of the
add with cu^c acetate : at 130° C. it loses water and some add. The ferric $tiU u
anhydrous : it is obtained as a bulky flesh-coloured powder, when a boiling solntioii
of tne add is predpitated by ferric chloride. The normal lead-salt lb obtained in ei7>*
tals when a boiling solution of the add is added to bade acetate of lead, until a perns-
nent predpitate is formed : it ia decomposed by washing with water, and jieUi haae
salts.

The mafwanese-salt contains 2 aq., one of which it loaea below 100°, the other it
133° C. The potassium^ and sodiwmrsalts crystaUise with difficulty: idien heated,
they are decomposed, emitting sparks. The silver-salt, C^'AgNO*, is obtained in
pearly Iftminn* by crystallising from hot water the predpitate which nitiobeniotte of
ammonium gives with nitrate of silyer: at 120° C. it turns grey, and loses add, it
260° it ezpl(^es in dosed yessels. forming nitrobenzeneL The zinc^t contains ^ aq.,
which it loses at 140° : it crystallises from the filtrate which runs off from the gelatinoai
predpitate formed by nitrobenzoate of ammonium with sulphate of zinc: this pre-
cipitate is a basic saltw

Nitrobenzoie Ethers. NUrobenzoate of Methyl, C^'NO^sCTH^CH^O^
(Chancel, Compt Chim. 1849, 179; Bertagnini, Ann. CL Phann. Iixix.269L)
— Prepared in a similar manner to nitrobenzoate of ethyl, whidi it nsemhks
in all its reactions. It forms small, white, nearly opaque right ihombie pnma,
which melt at 70° and boil at 129° C. : are insoluble in water, slig^tlj solnhie in
alcohol and ether, somewhat moro in wood-«pirit : have a fiunt aromatic smeD, and a
cooling taste.

NitrobetuoaU of Ethyl, C»H»NO* « C^*((XH»)(NO«)0«. (E. Kopp^ Compt wii
zxziy. 616; Chancel, loe, cit. ; Bertaenini, loe. eit. ; List and Limnriehti Ann.
Ch. Pharm. xc 206.) — A boiling alcoholic solution of nitrobenzoio ada is saturated
with hydrochloric add : after some time water is added, and the predpitated ether if
agitated with hot sodic carbonate, washed with cold water, dried between fitterfaps;
and crystallised from^ther-aloohoL Bertagnini prepares it by crystallising a solitioD of
chloride of nitrobenzoyl in alcohol ; and £st and Limpricht, by dropping beoaoate of
ethyl into a mixture of 1 pt. nitric and 2 pts. sulphuric add. It forms tight dwDbie
prisms, which melt at 42°, and boil at 298° C. : smells like strawberries, uid hai a
fresh taste ; is insoluble in water, readily soluble in alcohol and ether. Boili]i|potadi
decomposes it into alcohol and nitrobenzoie add : with ittnm/>m> it ftnns mtrobea-
zamide and alcohol : with sulphide of ammonium, benzamate of e^yL

Nitrobenzoate of Dibromophenyl. {Nitrobibromobensophenide.) C^H'BrKO* ■■
C^HXC"H'Br>)(NO')0' (List and Limpricht, loc. rt<.)— Separates as a rsinwhea
benzoate of dibromophenyl is added to nitrosulphuric add ; the addition of water
scarcely predpitates anything more. It crystallises from hot alcohol in nodules, ooof
posed of small needles : from a concentrated solution, it separatee as an oil It metta
between 90° and 100° C. : is insoluble in water, sparing^ soluble in hot akohoL
Alcoholic potash decomposes it into nitrobenzoie and dibromophenylic adds.

Nitrobenzoate of JHnitrophenyl. C»«H*N»0« - C»H*[C^NO«)*](NO«)0« (Li at and
Limpricht, loc. cit.)— "Powdered benzoate of phenyl is added to cold nitsrasulphuie
acid, whereupon it dissolyes, and yellow cnystals separate out, which are increased Ij the
addition of water ; these are washed, first with cold water, then with alcohol It feimi
a white crystalline powder, which turns yellow when heated, and mdts at 160° C. : on
cooling, it solidifies to a yellow glass, which gradually becomes opaque. It is insoluble
in cold water or alcohol^ sparingly soluble in hot alcohol or in ether. Heated on
platinum-foil, it burns with yellow smoky flame : heated in a tube, it explodes feebly.
It is decomposed by alcoholic potash. Sulphide of ammonium dissolves it with deep-

BENZOIC ANHTDBIDE. 557

red oolour : bj era^oration on a irater-bath, a dark-Tiolet resinoiiB mass ia obtained
partlj soluble in acida.

Diniirohengoie Acid, CH«IW - CrB*(NO«)*0* (Cahonrs, Ann. Ol Phys.
[3] xxT. 80). — ^When fiued benzoic acid is gradually added to a warm mixture of nitric
and snlpbnrie adds, it dissolves with a&ght evolntion of gas: the whole is then
boiled (ror 1 hour, Cahoors ; — for 6 honrs, Voit), and as soon as it begins to be torbid,
it is oocded and water added, which precipitates yellow flakes, which are washed with
water, dried, and oystallised fiom boilins alcohol Dinitrobenzoic acid is thus ob-
tained in short shining prisms, which mdt at a gentle heat, and sublime in delicate
needles. It is slightly soluble in cold, more in boiling, water ; readily in alcohol or
ether, especially on heating. It dissolves in hot nitric acid, and crystallises on cooling.
Cold snlphnric add diss<Mves it unaltered, but decomposes it when heated strongly.
Solphide of ammonium and other reducing agents convert it into diamidobensoic acid.
The alkaline dmitrobensoateM are soluble and ciystallisable : the lead- and tUversalts
are slightly soluble. DinitrobeHsoic ether (dinitrobenzoate of ethyl), CH'NK)* b
C'H*(G^*)(Na^K)*, is obtained by saturating absolute alcohol with the acid, or heat-
ing tae acid witn alcohol and sulphuric acid : it forms oily drops, which solidify on
cooling, and axe washed with dilute ammonia, and crystaUised from hot alcohol Long
delicate needles, with a slight yellow tinge : decomposed by strong potash, especially
on heatings into alcohol and potassic dinitrobenzoate. Di^nstion with alcoholic am-
monia converts it into dinitiobenzamide : sulphuretted hyozogen converts it into di-
amidobenaoic acid. (Yoit^)

Nttrocklorohenzoie Acid, CH^NCIO* - CrH«(NO«)aO« (Limpricht and
V. Uslar, Ann. Ch. Phazm. cii 261). — ^When chlorobenzoie acid is dissolved in Aiming
nitric acid, there is no immediate precipitate, but the solution oontinnes fot several
days to deposit colourless tables of nitrocmorobenzoie acid. These melt at 1 18^ C. ; are
sohible in alcohol and ether ; melt in warm water, dissolve on boiling, and do not
separate out on cooling. The dart«m- and silver'Salts only are known : the latter,
C^'AffClNO^ + ( Aq (?), forms small shining laminae, tolerably soluble in water. For
nitrocmorokenzoic ether, see above, chUorobetuoic ether, F. T. C.

SXVXOIO AXiCORO&. Syn. with Sxnztlio Alcohol {q, v,)

mmamata AJnmsisa. BeruoaU of Benzoyl, C'^Hi"^* » (C^H))>.0
(Gerhardt (1862), Ann. Ch. Phys. [3] zxsviL 299; Wunder, J. pr. Chem. IzL
498 ; Heints, Pogg. Ann. xcii 468). — formed by the action of chloride of benzoyl on
alkaline oxalates or benzoates : also of oxychloride or perchloride of phosphorus, or
chloride of sulphur on alkaline benzoates, the first stage of the reaction being the
formation of chloride of benzoyl : also by the dry distillation of aoetoboizoic and similar
anhydrides:

CB«KO« + C»H*0C1 - C"H»*0« + KCl

OH)^K« + 2C'H»0a - C"H'«0» + 2KC1 + CO + C0«.

2C^H»K0« + Pa» « C"H'«0« + 2Ka + POCl"

8CH»K0« + 3SC1" - 4C"H'H)« + 6KC1 + SO<K» + S*.

Equal parts of dry benzoate of sodium and chloride of benzoyl are heated to 130^ 0. on
a sand-bath, whereby a dear liquid is produced, from which cldoride of sodium separates
out : the cooled mass is washed with cold water containing sodic carbonate, and ciys-
ft<Jlia<»d from ether or warm alcohol The previous preparation of chloride of benzovl
is avoided by employing perchloride or oxjrchloride of phosphorus (5 pts. oxychloride
to 1 pt. benzoate). Oxalate of potassium is heated with an equal weight of chloride
of bencoyl^ with constant agitation, till the smell of chloride of benzoyl has disappeared ;
and the cooled mass is suspended in cold water, washed with water containing ammonia,
and erystalliBed from alcohol (Gerhardt). In preparing large quantities, it is better to
purify the product liy distillation than bjr ciystallisation from alcohol

Benzoic anhydride forms oblique rhombic prisms, sometimes smelling of bitter-almond
oil or benzoic ether: it mdts at 42^ C, and diJiB\i\a undecomposed at about 310^. It
ia insoluble in cold water, soluble in alcohol and ether : the solution when fresh has no
acid reaction. It melts in boiling water, and remains fluid for a long time, even when
agitated, and is slowly converted into benzoic add, which dissolves. Caustic alkalis
convert it much more rapidly into benzoic add. Aqueous ammonia does not attack it
in the cold, but dissolves it on heating, forming benzamide and benzoate of ammo-
nium : the same reaction takes place when it is heated in dry ammonia :

C*H'*0« + 2NH» - CH^O + C'H»(NH«)0«.

Aniline acts similarly, forming phenylbenzamide. ^Gerhardt.)

One atom of benzoyl in benzoic anhydride is capable of bdng replaced by other add
xadiden, fimning a series of anhydrides containing benzoyl They are obtained by the

B5S BENZOIC ANHYDRIDE— BENZOICIN.

action of chloride of benzoyl on the alkaline salts of other monobooo addi, or, eoo*
Terselj, by treating alkaline benzoates with the chloiides of moaobaiic aadndidci.
They are generally decompoeed by heat into two simple anhydxidot: by vitcr, nd
more rapimy by alkalis, into two adds.

Bbkzoacstio Anhtdbixib. See Acbtio Ahhtdbidb.

BmwoAHOBLio Anhtdbidb. C»*BPK)«-C»H'0.C'HK).0 (Chiozsa,Aim.(2h.ay«.
[3] -rni^- 210). — Produced by gently heating chloride of bensoyl with angdate of
potassium. It is a limpid ou, EeaTier than water, somewhat leas fliiid than ta^Sik
anhydride, and qnite neutral to test-paper. It smells like angelic anhydride, but endti
much more acnd Tapours when heated* In a mixture of loe and salt, i thiduni
slightly, without ciystallising.

BBNZooNKAiao AxHTDBiDB. BmMoaU of OinnamvL CH'H)* - C'HH).O^0.0
(Oerhar dt^ ioe, eU.) — Obtained by heating 7 pts. chloride of benso^ with 10 oti. ^
cinnamate of sodium, and puri^ing the product as in the case of benioie anhjdridoL It is
a thick oil, colourless and odouness, which gradually becomes acid when eipoBod to moist
air. Spe<afic graTity 1'184 at 23^ C. Is decomposed by distillation, ^iefiliiig a feOmr
oil, ftiTftlHng of cinnamol, which gradually deposits crystals of bensoic sohTdziaB, asd
an add substance soluble in sodic carbonate.

BBRSoouMnao Anhtdbidb. Bengoate of Cum^L C^HiH)* - C^H).C^*ff -0.0
(G-erhardt, loe. eit) — Obtained like the preceding, euminate being sabttitiited for
cinnamate of potassium. Besembles the preceding in appearance and beharioor in
moist air. Specific grarity 1*115 at 23^ C. Is decomposed b)r distillation; wfacnheatod
in a closed vessel, it appears to volatilise without decomposition. Aqusoaa afflmoda
oonverts it into cuminamide, and benaandde, or benzoate of anmioniunL

Bbnzoktbistio Anhtdbidb. SensoaU of MyristyL C°H^ » CHK).(7^.0
(Ghiozza and Malerba, 1866). — Obtained by heating chloride of beoioyl wi& ay-
ristate of potassium. Crystallises firom boiling ether, in whidi it is slighdy sololde, la
shining lamints : melts at 38^, and solidifies at 86^ C.

Bbbzooenanthtuo Anhtdbidb. Beruoaie of (EnaniJ^l, Ci<H>H)*»C'HK).CH"0.0
(GhioEsa and Malerba, Ann. Ch. Pharm. xd. 102).— ^Obtained by the aetkm of
chloride of benzoyl on tsnanthylate of potassium. Colouriess oil, of speofle oarity 1'043
at 11^ C. ; smells like oananthylic anhydride : exposed to the air, it yiddi ayatali of
benzoic add.

Bbnzopblabgonio ANHTDBniB. BefUPoateofPdarffonyl O''H*'O'b(7HK).CH**0.0
(Ghiozza, Ann. Gh. Phys. [3] xttit. 310). — ^Prepued like the forefloiog oompounda.
A heavy oil, resembling pelazgonic anhydride. A little below (P C. it aoudifies to tlie
consistency of butter : is decomposed by heat into benzoic and pelaigonic anhydzida.

Bbnzostbabio Anhtdbidb. BenzoaU of StearffL, G^H^H)* » C^K).C"H*K).0
(Ghiozza and Malerba, loe, eit,) — Prepared by heating chloride of benzoyl and poUaae
stearate in an oil-bath. Shining scales, which mdt at 70° O.

Bbnzovalbbio Anhtdbidb. BeneoaU of VaUryl. G^'H'^O' « 0'HK).C'HK).0.
(Ghiozza, Ann. Gh. Pharm. Itttiv. 106). — Chloride of benzoyl acts violently onTik-
rate of potassium: the product is a heavy, neutral, strongly refracting oO, amdliag
like valeric anhydride. At about 260° G. it is decomposed into benzole and Tikrie
anhydrides.

SubftituHon-jtroducts of Betuoio Anhydride,

Bbnzonitbobbnsoio Anhtdbidb. Bensoate of NUrobensoyl, G>*HVO*«
G*H»O.GrH*(NO»)0.0.— 3 pts. chloride of benzoyl are heated with 7 ptadiymtio.
benzoate of sodium, and the product is purified as in the ease of benzoic anhydzide.
Crystalline : more stable than the following compound. (Gerhardt, loe. eit.)

NiTBOBBNZOio Anhtdbidb. Nitroberuoate of NiirobensoyL C^<H*N^'"
[G'H*(NO«)0]«.0. — 8 pts. nitrobenzoate of sodium are heated to 160° Cwith 1 pt
oxychloride of phosphorus, till the smell of chloride of nitrobenzoyl has disappeared.
On treating the product with cold water, a white mass is obtained, almost inadaUe in
alcohol and ether, less fiisible than nitrobenzoic add, into which it is qmAlj oob*
verted by washing with water. (Gerhardt, loe, eit,) F.T.C

BBwxozo snnnts. See p. 652.

BavSOZOZW. (Berthelot, Ann. Gh. Phys. [8] xli 290.)— The name gire&V
Berthelot to the artifldal fa.ts obtained by the action of benzoic add on ffjcain.
Glycerin being a triatomic alcohol, C*H».H*.0", contains 3 at H replaceable by other
radides ; and Berthelot has succeeded in obtaining the compounds in which 1 and S H
respectively are replaced by benzoyL

BENZOIN. 559

IfonobinMoiein. Betuoaie of Glyeyl. C»»H»«0^ - 0»H».C'H»O.H«.0». — Ob-
tained bj heating benaoie acid with glycerin in a sealed tube, for fortj-foor hours, to
12(^—160^ C. if the acid be in excess, to 200^ G. if the glycerin be in excess; at a
higher temperature a shorter time suffices. The product is purified by washing with
potasne caroonate. It is a oolonrlessi neutral, yeiy viscid oil, with a bitter aromatic
tute, and % slight balsamic smell; specific gravity 1*228 at 16<^'5 0. At 40^ it is a
ttan^fiarent neariy solid mass, that can be drawn out into threads ; it boils at 820°, but
deoompoees at the same time, yielding acrolein and benzoic acid. It is insoluble in
water, scarcely soluble in bisulphide ^ carbon, readily in alcohol, ether and benzene.
It ozidiseB veiy slightlj] in the air. Heated with potash it forms {wtassic benzoate ;
vith •™wi<>w<*, bemaiinide. Alcohol and hydrochloric acid convert it in the cold into
|irecana and benzoate of ethyl; the same decomposition is effected when its alcoholic
•oInCion is heated to 100<^ C. for Ibrty-eight hours.

TrihenMoiein. TribensoaU of Giycyl. C»*H»0 «- 0»H».(C»H«0)«.0«. — Ob-
tained by heating monobenzoicin for four hours to 2&(P C, with 10 or 15 pts. benzoic
acid ; tibte product is washed with sodic carbonate, and repeatedly crystiulised from
ether. Laise white needles, unctuous to the touch, and Aising pretty readily.
Alcohol and hydrochloric acid decompose it like monobenzoicin. F. T. C.

mmmWOXm. JBitter^inond-oil-<famphor. C*«H*K>*. (Liebig and Wohler,
Ann. Ch. Phann. iu. 276; Bobiquet and Boutron-Oharlard, Ann. Ch. Phys.
[2]xliv. 352 ; Laurent, ibid. lix. 402 ; Ixvi. 193 ; Zinin, Ann. Ch. Fharm. xxxiv. 186.)
— Ftrat described by Stange, 1823 ^Repert Phann. xiv. 329) ; first correctly examined
by laebig and Womer in 1832. It is frequently contained in crude bitter-almond oil,
and is obtained as a by-product when the oil is purified by lime and ferrous chloride ;
the residue is treated with dilute hydrochloric acid, and dissolved in aloohoL Pure
bitter-almond oil (hydride of benzoyl) is converted into benzoin by cyanide of potas-
sium. To pr^Mure benzoin from crude bitter-almond oil, the oil is mixed with its own
volume of a saturated alcohoHc solution of potash ; after a few minutes, the whole
solidifies to a mass of o^rstals, which are purified by recrystallisation from alcohoL
As the amount of benzoin in different specimens of the crude oil varies considerably,
according to their age and to the amoxmt of prussic add which th^ contain, it is always
advisable to test a small portion first with alcoholic potash ; if it does not speedily
solidHy, the crude oil had betted be first freed from orussic add, and then treated by
the iWMniittg meUiod. Pure oil of bitter-almonds is reaoily converted into benzoin by the
addition of a dilute alcoholic solution of cyanide of potassium, or of alcoholic potash to
which a few drops of hydrocyanic add have been added : this reaction is difficult to
accowit fbr.

Beoaoin is iBomerie with benzoate of bensyl, and polymeric with hydride of ben-
wajL It fi»ms shining, transparent, colourless prisms, without smell or taste ; melts at
120*^ C, and oystaUises on cooling ; if Airther heated, it distils undeoomposed. It is
insolnble in eold, slightly soluble in hot water, whence it crystallises on cooling ; more
soluble in hot than in cold alcohoL It bums readily in the air, with a bright smoky
flame. Its vapour passed through a red-hot tube is reconverted into hydride of ben-
EoyL When heatea in cUorme, it yields benzil and hydrochloric add. Bromine at-
tacks it, evolving hydrobromic add, and forming (probablv) benziL Strong nitrio
meid eunterts it into benzil. Bul^hvHG add dissolves it, rorming a violet solution,
which blarV*^" when heated. K>iling potash does not attack it; frued with solid
potash, it evolves hydrogen and yields benzoic add: C'«H"0* + 2KH0 - 2C'H*E0'
•4- H^ ; boiled with alcoholic potash, it is coloured violet, and yields benzilio add, with
evY^ntioii of hydrogen : C^*WHP + EHO - Ci'H"KO* + H*. With amnumia, it
yields, among other products, benzoinam and benzoinamide. Perehloride of phoa-
phorua attacks it violently, yielding chloride of phosphoryl, and other products diffi-
cult to obtain pure. (Cahours.)

Benzoin combines with chlorides of add radides, yielding compounds representing
benaoin in which 1 H is replaced by an add radidei Zinin (Aim. Ch. Pharm. dv.
116) has obtained the foUowiug : —

Aeetyl-bemoin. C»«H"0«-C"H»>(C*H«0)0«.— 4 pts. of benzoin dissolve in 3 pts.
idiknide of acetyl at 40^—50^ C, with evolution of hydrochloric add ; when the solution
is complete, the whole is heated to 100^ as long as vapours are evolved : on cooling, the
niodnct dowly solidifies into crystals, which are recrystallised from alcohol or ether.
It oystaUises from the ethereal solution in large rhombic prisms and six-sided tables ;
from the aloohoHe solution in thin shining crystals. It is insoluble in water, melts
below 100^, and does not always crystallise on cooling. Sulphuric or hydrochloric
add, or aqueous potash does not act upon it ; with alccmolic potash it yields acetate
and benzoate of potassium. Strong mtric add converts it into a mixture of two nitro-
prodncts in the rorm of a visdd colourless mass, insoluble in water, soluble in alcohol
and ether; the solution depodts crystals.

660 BENZOINAM — BENZOIN-GUM.

BenEOffUbeneoin. 0*iH>*0'->0**H"((7H*0)0<.-<:Uorid6 of bennnfldMiMitiet
iqx>n bensoin in the cold, but at aboat 70^ C. the bensoin dinolTes and hyw)dbkrie lad
18 flfTolTed ; the whole is then heated to neazly the boiling point of chloride of bouoyl
(196^ C.)| when a vellowiah oilj liquid is obtained, which solidifies into oystab on
cooling. Thia prodnct la purified by being ponred while liquid into cold 76 per ent
alooh<^ when bensojl-benzoin separates aa a crystalline poirder, which is waaaed on i
filter with cold alcohoL It is inaolnble in water, spazindk soluble in oold nkohol, lohiUe
in 6 pts. boiling 80 per cent alcohol, iHience it crystdlises in thin colonrifiM media;
readu J soluble in etiier, and cryBtaUises by spontaneons eTi^mration in large dumag
rhombie prisms ; soluble in chloride of benaoyl, and may be heated with it to 150^ CL
without alteration. Melts at 126^ 0., and crystallises rery sbwly on cooling, Chkrine
does not attack it; neither does hydrochloric or dilute sulphuric acid; strons aalpkiine
acid decomposes it. Aqueous potash does not attack it ; alcoholic potash £aMh«i it
witi^ a Tiolet colour, and, on boiling, conTsrts it into benzoate and bemilate of
potassium.

NitrohensoyUenJBoin. C«H»*NO»-C'*H>»(C»H*(NO«)0)0« -Strong nitric add
(spedflc graTity 1*61) dissolves bensoyl^bensoin, which, if too Uttle acid be emplqjred,
crystallises out again unaltered; but if at least IJ pt. acid be taken, and the ydlom
solution poured into cold water, a resinous substance separates, which is a miztoie d
two nitzo-products. Ether dissolves one of these, and aoandons it on evapontian as a
thick oil ; the other, which is nitrobenzoyl-benzoin, remains imdiasolved aa a oyBtal-
line powder, which is reczystalliaed fipom boiling alooh(^ White shining scales, com-
posed of rhombic tables, aggregated into scalariform groups, insoluble in water. Mdts
at 137^ C, and solidifies at 110° to an amorphous maBS, which very slowly beooDei
crystalline. Strong nitric acid dissolves it unaltered and in large quantities, espeei&Ily
if gently heated ; on boiling the solution a new body is formed, solnble in ether,
which separates as a powder on cooling. F. T. C.

BnXOnrAX. C*H*«N*0. (Laurent, ComptChim. [1846] 87).— Panned I7
the action of alcoholic ammonia on bcnsoin :

2C«H>«0« + 2NH» « 0»H«NK) + 8H«0.

Obtained, together with benaoinamide and other products, when a mixtore of aloobolk
ammonia and benzoin is left for some months in a closed vessel Forms white mi-
crosoopic inodorous needles, insoluble in water; slightly soluble in hot ether or rock-
oil, whence it crystallises on cooling in very bullgr needles, readily solable in hot
alcohol containing hydrochloric aci^ whence it is partially precipitated by ^n^«
entirely by ammonia. Melts when heated, and paztfy solidifies on cooling. Potash
does not attack it; strong sulphuric add dissolves it with red colour, and water jnre-
dpitates orange fiakes. F.T. C.

BanonrAamia. C«H>«N«. (Laurent [1837], Ann. CL Fhya [2] bni
189.) — Formed by the action of aqueous ammonia on benzoin :

3C*H«K)« + 4NH" - C«HW* -i- 6BTO.

Obtained as a white powder when benzoin and aqueous Mnmnniifc are left for
weeks in a dosed vessd ; it is boiled in alcohol to remove excess of bcoaoiB. and
cr^tallised firom boiling ether. A white, tastdess, odourless powder, conasting of fine
microscopic needles ; insoluble in water, very sparingly soluble in aloohd or etlw;
melts when heated, and solidifies to a fibrous mass ; distils without decomposition.

F.T.Ci

The commercial name of a resin ^^ch flows from the baik of
Styrax hemcin^ a tree growing in Sumatra, Borneo, Java^ and Siam. It comes into
t^e market in different forms. The Siamese gum occurs in irregular flat fragmentSi
about an inch long, which are reddish-yellow on the outdde, white and shining in the
inside. The common or Calcuttargum forms larger irregular lumps, brittle, of a dirty
reddish-grey or brown colour, with many light coloured spots, and often contains frag-
ments of wood and bark. The Siamese almond-gnm appears to be a miztnre of bou
these kinds. The commercial gum has a pleasant smell, especially when heated, aoi
a sweetish, sharp, balsamic taate. It melts when heated, evolves vapours of benute
acid, and bums with a smokjr fiame. Specific gravitv 1'063— 1'092. Alcohol da-
solves it completely, excepting impurities ; ether partially ; boiling water dissdfvs oat
benaoic add.

According to Un verdorben (Pogg. Ann. viii. 397), Stolae (Beri. Jahrb. Phaim.
xxvi. 76), Van der Vliet (Ann. Ch. Pharm. xxxiv. 177), and E. Kopp (CompL
rend. xix. 1269), gum-benzoin is a mixture of three resins, which may be distingtawd
as a, /9f and 7, t<^ther with benzoic add, and a small quantity of a volatile oil The
whole of the benzoic add cannot be driven off by heat. According to K ol be and ^'^
mann (Ana. Ch. Pharm. cxv.lld), some varieties of gum-benzdn, especially the ahaoad

BENZOm-GUM— BENZOLACTIC ACID. 561

ffim of Sumatra, contain not benzoic acid, but an acid iBomeric with tolnylic acid,
C'H'O^ which meltB to a dear liqnid under hot water, crystallises in forms quite
difierent from that of benzoic add, and yields hydride of benzoyl lidien treated with
oxidising agenta.

UnTeraorben SCTaratee the resins in the following manner: — ^The powdered ^nm is
eztncted with bouine sodio carbonate, which dissolves out all the benzoic acid and
the resin 7 ; the allumne solution is pitecipitated by hydrodiloric acid, and the preci-
pitate treiUed with boiling water, whieh dissolves the acid only, leaving the resin 7
insoluble. The portion insoluble in sodic carbonate is washed, dried, and digested with
ether, which dissolves the resin a, and leaves the resin 0 undissolved. Abiding to
Kopp^ the ethereal solution of a gradually deposits a small quantity of a fourth resin, 9,
of a reddish-brown colour. Analyses of two spedmens d gum gave the following
results (Kopp) :

I. II.

Benzoic add 14*0 14-6

Besina 520 48 0

BesiniS . . \ . . . 26-0 28-0

Besiny 80 3*6

BednS 0*8 0*5

Imparities 6*2 6-6

Kopp fiiitbeir statea that the white spots in the gum are composed only of resin a, and
contain 8 — 12 per cent, benzoic add; while the brown portions consist of resins $
and 7, and contain as much as 16 jper cent, add (18 per cent according to Unverdorben).

The resin a is readily soluble in ether and alcohol, insoluble in naphtha; soluble in
potash, and not reprecipitated by excess ; insoluble in ammonia. Salts of the earthy
or heavpr metals give, in its alkaline solution, predpitates which are insoluble in ether.
Aeeording to Van der Yliet it is a mixture of resins $ and 7, for it is decomposed into
these two resins by prolonged ebullition with sodic carbonate. Besin /9 is a brownish
mass, soluble in alcohol, insoluble in ether and volatile oils; soluble in potash, and re-
piedpitated by excess ; insoluble in ammonia. Besin 7 is dark-brown, soluble in
akobol, slightly in ether and volatile oils, insoluble in naphtha. Potasdc carbonate
sbwiy dissolves it, and the solution is predpitated by sal-ammoniac. Its alcoholic
sofaition predpitates acetate of lead, but not acetate of copper. Besins • and 0, when
precipitated l^ adds from their alkaline solutions, are converted into 7 by exposure to
the air.

The following are the results of the analysis of these resins, and the (unreliable) for*
muiie^ which Van der Vliet has deduced therefirom :

V. d. V. Mulder.

Besina Carbon 729 71*8 731 r»TT«n» Aj.^

Hydrogen 7-2 71 7-8 C»»H«0»-^+7

Besin 0 Carbon 711 710 717 p»wtin«4

Hydrogen 6*2 6-8 6-9 ^ ^ "^

Besin 7 Carbon 73-2 73-2 73-2 pi»TT«n«*

Hydrogen 86 84 8*6 ^ ^ ^^

By the dry distillation of the resins of gum-benzoin, completely freed from benzoic
add, Kapp obtained a solid substance, which he regturds as the odorous prindple of
the gum, and a rose-red distillate, which graduallv becomes darker, and contains crys-
tals of benzoic add ; the fluid portion appears to be hydrate of phenyl. By the same
process, Ctahours obtained an ofl, which jDeville (Ann. Ch. Fhys. [3] iiL 192) regards
as bensoate of ethyl. . When they are distilled to dryness, with excess of nitric acid,
nitrous fbmes are^ abundantly evolved, and a distillate is obtained, containing hvdride
of bensovl, benzoic add, and hydrocyanic add ; boiling water extracts picric add from
the resiaue, and leaves a yellow powder, benzoereHo aeid (q. v,) Sulphuric add dis-
solves the resins to a common solution, whence the addition of water separates them
ahnosi completely as a violet predpitate ; the add Hquid, decanted and neutralised
with lime yields a soluble caldum-salt. F. T. C.

mmmtOUkOTia A0Z9. BeneamOchaaure. C^*H>»0« » CH'O.C^H^O.H.O*
(SocoloiF and Strecker, Ann. Ch. Phaim. box. 46. Strecker ^nd, xci. 369). —
This add is analogous to benzoglvcollic add, representing lactic add in which 1 at. of
of basic hydrogen is replaced b^ benzoyl, just as benzoglycoUio add represents
gljeoDic acid in which 1 at of basic hydrogen is similarly replaced.

It is prepared by heating 10 pts. of syrupy lactic add with 14 pts. of benzoic add
in ao od-bath to 160^ C, finally raising the temperaturo to 200^ and keeping it there
for some hours. Water distils over, and some benzoic acid sublimes. The residue in

Vol- L 0 0

562 BENZOLACTIC ACLD-BENZONE,

the retort Bolidifles on oooliog to a oytsalline mass of benzoic and beDsohdie

These are separated by partial saturation with sodic carbonate, vhich taktt up the
benaohictic acid first ; the solution is filtered from the b<Mttoic add, and freed fron
the small quantity of benzoic acid which it contains by agitation with etiier; on the
addition of hydrtMshloric aeid, benaolactie acid separates in crystals, wlueh are puified
by recrystalUsation from boiling water, or from ether-aleohoL

It forms colourless tabular or roeai^hi^ped crystals, unetuoos to the tondi : melts at
112^ C, and solidifies very slowly on cooling to a ciystidline mass; soblinea nnde-
composed when heated eonaideraUy aboTe 120^. It dissolyes in 400 pte. oold, and ia
mucn less boiling water : when boiled with not enough water to diasolfe it, the
excess of acid melts and the sedation beoomes milkY on cooling, and daiifiesTeiy
slowly, with separation of ciystals. It dissolyes readily in alcohol or ether, the latta
removing it entirely from its aqueous solution ; after drying in the air, it does notkie
any water when heated to melting. By prolonged boiling in water, it is deeompoeed
with benzoic and lactic acids: the decomposition ia aooelezated by the addition of a
dilute acid.

The benzolactates are mostly dystalline, soluble in water, and closely reaeinble the
benzoates, from which, however, they are distinguished by their nentnl sdotioB not
being precif»itated by normal acetate of lead. The barium-salt, CH^BaO* •>■ S aq,
crvstamses in thin, shining, six-sided laminse, which lose their water at 100^ C. The
suver-salt C'*H*AgO^ is a flocculent precipitate, soluble in boiling water, whence it
crystallises in fine needles. The 9odiumrsalt orystaUises in eolovzieaa needles from
boiling alcohol F.T.a

»&ZO A&OOSO&, See BBNZTZjna.

Syn. with Amabiw (j'.t;.)

C«'H»0* (?) (Rochleder, Ann. Ch. Pfaarra. xll M).-¥onied
together with benzostilbin, when hydrobenzamide is heated with sohd potML The
mixture must be heated till it blackens; the product ia powdered, extracted vith water,
washed with cold hydrated aleohol, and the residue dissolved in strong sol^nrie aoi
The blood-red solution thus formed becomes greenish-ydlow on addition of dilate
alcohol, and deposits small cxystals of benzohms : on addition of water, it aepaiatei in
the uncrystalline state. It is insoluble in water or alcohol; mdta at 248^0, wd
sublimes almost without decomposition, when more stron^y heated. Strang nitiie
Hcid dissolves it with a reddish-yellow colour, and it ia reprecipitated \fy water; Aming
nitric acid decomposes it, forming a yellowish resin wita evolution of nitroos fomei.
It is not attacked by aqueous potash. Bochleder's analyses give a mean oomposition of
C 63-6, H 6-2. F.T.a

See Bemzamzdb.
ITIO JLaaSJISIBB* See Bsmoic AmnmBiDB.
Benzophenane. Fkenyl-henzuyL C"H»»0 « Off.CHK) (PMigot,
Ann. Ch. Phys. [2] Ivi. 69. Chancel, Compt. rend, xviii 83.; Ana. CL Fhtfu.
Ixxx. 26). — The acetone of benzoic acid; it ia formed by the dry distillation of bemoate
of calcium:

2C^»CaO« » C»*H"0 + COKJa»

Biy benzoate of calcium is mixed with ^ of its weight of quick lime, and Stalled in
an iron mercury bottle, fitted with a b^nt gnn-barreL The red liquid which puwi
over (which P^ligot called benzone), contains, — ^besides benzene, — benzene, hymide of
benzoyl, and two solid hydrocarbons isomeric with naphthalin. On distinins it in i
tubulated retort, benzene first passes over; and the temperature rises rapidly: the
portion which comes over at 316^ — 326^ C. ia collected apoiti and ooosists of nearir
pure benzone, which solidifies on coolings and may be obtained quite pore byieoTital'
Usation from ether-aloohoL 1 kilogr. benzoate of calcium yields about 260 gnsi.
benzone.

Benzone forms colourless, transparent crystals, often of considerahle sise^ belongag
to the trimetric system. It melts at 46^ C. to a thick oil whidh does not soiidiff
unless it be agitated ; boila at 3 1 6^ and distils undeoompoeed : its vapour ia very inflaai*
mable, and bums with a bright flame. It has a pleasant smell, somewhat Kketi^^**
benzoic ether. It is very soluble in ether, less so in alcohol, not at all in water; i^xW
nitric or sulphuric acid oissohres it abundantly, and water reprecipitateB it unchanged.
When heated with soda-lime to about 260^ C. it is decomposed, yielding sodic beaioate
and benzene, but not a trace of hydrogen :

C«H».C'HH) + NaHO - C^*.H + C^»O.Na.O.
Dinitroheneonc, JHnirobensoph^nane. C«HWO»=C*«H^O*)K).— WaimfinAg

BENZONITRILE. 563

mtrie add eooTerts b«nione into a thick oil, which solidifies Torj slowly ; other dis-
uoitwrn it and depoflits it speedilj in the fonn of a yellowish ciystalline powder, which
is dinitiobenaonA. Bedncing agents conyert it into diphenyl-carbamide (flayine) :

<?»H»N«0» + 6H«S - C"H««N'0 + 4H«0 + S«.

lUvine.

Of ihA two hydzoearbons, isomerie with naphthizin, mentioned above, one cry-
stallises in large needles, fiiaible at 92^ C, the other, much less soluble in alcohol
and ether, forms small nodules fusible at 66^. The former is readily obtained by
diasolTing in strong sulphuric acid the liquid obtained by the dry distillation of
calcic benzoate ; it immeaiately solidifies on the surface, and is remoyed, washed, dried
by filter paper, and crystallised from hot alcohol. The latter is best prepared by the dry
distillation of potassic benzoate with potash-lime : it then passes oyer alone, in solution
in benaol, which is distilled off in a water-bath, and the residue crystallised from
alcohoL It is also formed together with benzol, when ammonic benzoate is passed
orer heated baryta. ' F. T. C.

nmm MMM ITIIIJJL Cyanide of Phenyl G^'N-C^'.CN (Fehling (1844),
Ann. Ch. FharnL zlix. 91. Limprieht and y. Uslar, Und, Ixzxyiii. 133). — Ben-
zonitrile is obtained by yarious methods : — 1. Sy the drr distillation of benzoate of
ammonium, or by heating benzamide, either alone or with caustic Ume, or baryta,
phosphoric anhycuide, or perchloride of phosphoros : the reaction in all these cases
consists in the abstraction of the elements of water :

C*H»O.NmO - 2H«0 « C^»N.
Bens. amm.

N.C^»O.H* - H«0 - C'H»N.
Beniamide.

2. By, heating hipporie add, either alone (Limprieht), or with chloride of zinc
(Odss'inann). 3. By the action of chloride of benzoyl or benzoic anhydride on benza-
mide, or by heating benzamide with potassium (see Bbnzaicdb). 4. By the action of
chloride of benzoyl on oxamide (Chiozza) :

(rHK).a + N«.GK)«.H« - CTI*N + CNH + HQ + C0« + H«0.

ot on Ailphocyanate or cyanate of potassium (Schifi^ Ann. Oh. Pharm. zciz. 117,
ci.93):

2C'H*0.C1 + 2CNSK = 2C'H*N + 2Ka + C0» + CS«.

6. By beating bensoie anhydride with cyanate or sulphocyanate of potassium (Schif f) :

C»*H»0« + 2CN0K - 2C'H»N + CO«K« + CO*

6. By the action of mercuric oxide on thiobenzamide (g. v, under Bhnzamidb).

Preparation, — 1. When dry benzoate of ammonium is heated in a retort, ammonia
eecapes, benzoic acid sublimes, and water passes oyer with a few oily drops of benzo-
nitnle ; as most of the benzomtrile remains in the fdsed residue in the retort, this is
corered with water (to which a little ammonia is added), again distilled to dryness,
and the operation repeated as long as any oil passes oyer with the water: 12 oz.
beuBoie acid yield in 6 days, 6 os. impure benzomtrile. This product is washed with
dilnte hydrochlone acid, then with water, dried oyer chloride of caldum, and recti-
fied (Fehling). According to Laurent and Chancel (Compt chim. 1849, 117),
bensonitrile is more easily prepared b^ passing the yapour of ammonic benzoate oyer
heated baryta. — 2. One pt dry hippunc add is mixed in a warm mortar with an equal
bulk of quartz-sand and 2 pts. chloride of zinc dried as completdy as possible, and the
mixtnieisheatedinadryretorttoSOO^ — 360°C.: benzontnle then distils oyer, carbonic
anhydride escapes, and a little carbon is deposited ; 100 ffrms. hippuric acid (tiie utmost
precautions being taken to exdude moisture) yidded 33 — 40 grms. benzonitrile ;
calculation reqmres 67 grm. (Gossmann, Ann. Ch. Pharm. c. 72). — 3. According to
Bnekton and JSofinann, benzonitrile is best prepared by distilling benzamide with
phoaphorie anhydride.

Bomonitrile u a dear, colourless, strongly refracting oil, smelling like bitter-almond
oil, and hayin^^ a burning taste; spedfic grayity 1*0230 at 0°, 1'0084 at lO'S^ C.
K oppX At higher temperatures it is less dense than water, for it sinks in cold water,
bat rues to the surface when heated. It boils at 190*6^ C. with the barometer
at 733*4 mm. (Kopp), and distils undecomposed : its yapour density is 3'7 (expt) ;
its eoeflldent of rCTnction is 1*603 (Reusch). It dissolyes in 100 pts. boiKng
wnter, and separates out again on cooling; it mixes with alcohol and other in all
proportiona. Sulphur dissolyes in it with the aid of heat> and crystallises out on
cooling.

o o 2

566 BENZOYL: BROMIDE — CHLOBIDR

Wohler^s original snggeetion, is nsaaUj oonridered as existing in benioie sdd lad
many of its kindred compounds, — benzoic acid, C'H'O^ being regarded as Mnte of
benzoyl, G'H^O.H.0, bitter-almond oil, C'H'O, as hydride of benzoyl, &c This viev
explains the reactions of the minority of benzoyl-coifiponnds in a far more satiafiKtoij
manner than that of Beizelius, who, in accordance with his ommon that oijgea never
entered into the composition of an organic radide, oonsiderea C'£P as tiie radicle of
this group of compounds. The reac&ness with which many benzoyl-oon^Miinds pua
into phenyl-compounds renders it probable that benzoyl should be regarded as a
compound of phenyl, C*H*, with carbonyl, CO ; just as acetyl may be regarded ai a
compound of methyl and carbonyL One or mora atoms of hydrogen in beniojl is
capable of being replaced by a monatomie radicle (CI, Br, NO', £c) fermiog vfaat
may be called secondaiy or substitution-radicles (chlorobensoyl, CH^QO, nitrobeniojrl,
C'H^(NO')0, &c), wmch may be suraoeed to exist in ehloro* or nitro-bouoifi acid, ^
Benzoyl has not yet been isolated. Ben^ which baa the same composition, doei not
exhibit any analogy with other organic radicles. . F. T. C

BBirXOTXii BKOMIBB pr. BrombetuMldid. CHH).Br. (LiebigaadWohler,
Ann. Ch. Pharm. iii. 266.) — ^When hydride of benzoyl is mixed with bromine, heat is
evolved, and hydrobromie acid given off: the mixture is then heated, to free it com-
pletely from hydrobromie acid and excess of bromine. Thus obtained, bromide of
benzoyl is a soft, brown, broadly laminar, crystalline mass, semifluid at the ordinaiy
temperature, and melting at a very gentle heat to a brownish-yeUow liquid. It has
a faint aromatic odour, somewhat Uke that of chloride of benzoyl, and lb rndilj soluble,
without decomposition, in alcohol and ether. When heated with water, it melta, and
remains at the bottom, as a brownish oil, which is decomposed into beosoie and
hydrobromie acids only by prolonged boiling. It fumes alightly in the air, stnagly
when heated, and bums with a bright sooty flame. F. T. GL

saVKOTK, CB&0»iaB OV. ChlorhenzaUUdL C«HH>.CL (Liebig and
Wohler (1832X Ann. Ch. Pharm. lii 262; Cahoura, Ann. Ch. Fhys. [3] nii.
334; Gerhardt, ibid, xxxvii. 291). — Formed: 1. by the action of chknne on
hydride of benzoyl (L. and W.) — 2. By heating perchloride of pho^tioras vith
benzoic acid (Ca hours). — 3. By the action of oxychloiide of phosphorus on bensoatea
(Gerhardt). Also in small quantities, by the action of chlorine on mandelic add,
or on benzoate of methyl or ethjl (Malaguti, Ann. Ch. Phys. [2] Ixx. 374), and on
cinnamein (Fremy, ibid, 180).— -4. By heating benzoic acid to 200® C. with anuxtnre
of chloride of sodium and anhydrous acid sulphate of sodium or potassium.

Preparation. — 1. Dry chlorine is passed into hydride of benzoyl, the liquid beisg
^^radually heated to beiling, tiU no more hydrochloric acid ia erolved: tiis piodnet is
freed by heat from dissolved chlorine. — 2. A better and easier method is to wmeqai-
valent proportions of benzoic acid (122 pts.) and perchloride of phosphorus (209 ^)
in a tubulated retort ; a violent reaction takes place, hydrochloric acid is eTOiTed, and
a mixture of chlorides of benzoyl and phosphoryl diciiils over, heat being gndoally
applied. The mixed chlorides are separated by fractional distillation : at 1 10^ C, eUoiide
of phosphoryl passes over ; from 1 10® to 196®, a mixture of the two chlorides ; and from
196® to 200®, nearly pure chloride of benzoyl, which is readilyf):«ed from traces of oxy-
chloride by washing with water, and dried over chloride of ealcium.— 3. Sodie Imd-
zoate is treated^n a similar manner with oxrchloride of phoephoms : the reaetioD is
violent even in the cold, and if the oxychloride be slightly in ezoesss, efalands of
benzoyl and sodic phosphate are the only products:

3CH»NaO« + POa» - SCTH'O.Cl + PO<Na»,

otherwise benzoic anhydride is also formed. The distillate below 196® obtained is (S)
may advantageously be employed for this purpose^

Chloride of benzoyl is a clear colourless liquid, with a peculiar smdl, wfaidi RMB*
bles that of horse-radish and makes the eyes water. Sp«ciflc gravity 1*196 (L and
W.); 1-26 at 16® C. (Cahours): boils at 196®: vaponrnlensity (eznt) 4-W7
(C a hours) ; 4'901 (calc.). It is insoluble in water, but is decomposed slowly bj^
and quickly by hot water, into benzoic and hydrodiloric add : toe same deooiqMW*
tion is slowly effected when it is exposed to moist air. It is deocHnposed by akohol,
with evolution of heat^ into benzoic ether and hydrochloric acid : it does not act
upon pure ether. It is soluble in all proportions in bisulphide of caiboo, wiUwst
decomposition, and with the aid of heat dissolves sulphur and phoephonii^ wtidi
crystaUise out on cooling.

It bums with a bright, green-edged, veiy smoky flame. When boiled with _
alkalis, it is immediately decomposed into benzoate and chloride^ but it m^ n
distilled without alteration over annydrous lime or baryta. With dry ammcmia oroi-
monic carbonate, it forms benzamide and chloride of ammonium ; it is similariy deooa-

BENZOYL: CHLORIDE. 567

poMd by phenyUmine uid other alkaloidi, yielding plieiijll)eiizainide» fte. It is decom-
posed by certam metallic bromides, iodides^ mlphides^ and cyanideSt yielding broQiide,
iodide^ sulphide, or mnide of bensoyL With ndphocyanate of potassium^ it eTolyes
heat» and yields caroonie anhydride and sulphide, and bensonitrile (Schiff, Ann.
(%. Phann. zciz. 117): probably owing to the decomposition of sidphocyanate of
bennyl:

2(CNaC'HP0) - 2CrH«N + CO* + C!8« (Iiimpricht).

It is not attacked by potamum. When heated with hydride of copper^ it yields
hydride of benzoyl and sabefaloride of copper (C h i ozs a). With ckimde of idtmiinium,
it forms a crystalline eomponnd, bnt not with the chlorides of copper, magnesium, or
zinc: it is decomposed by ^ervA/loruis of tin (Casselmann). Witu the alkaline salts
of many oiganic monobasic adds, it yields an alkaline chloride and an anhydride,
e. ff. wiUi tSUe bensoate, benaoie anhydride ; with eodio pelaraonate, benzopelargonic
aouiTdride, &a (Gerhardt). Heated with formate of sodtum, it yields carbonic
ozide^ chloride of sodimn, and bensoic add :

CHKaO* + C»H»0C51 - 00 + NaQ + C^«0*(Oerhardt).

Heated with potaaie oxalate, it yields bensoie anhydride, potasdc chloride, and car-
bonic oxide and anhy^dride (G-erhardt) with oxamtde, bensonitrile and other products
(see BamoKiTBiz.), with most amides, a secondary or tertiary amide containing bensoyl.

When finely powdered aldekyde-ammonia is gradually added to chloride of benzoyl,
sal-ammoniac and benzoic add are formed, together with a. substance which crystal-
lises £pom hot alcohol in needles haying the compodtion CH'fNK)*, isomeric (perhaps
identical) with hipparaffin. It is insoluble in water, readily soluble in hot alcohol or
ether ; is fbdble, and sublimes partly undecomposed ; is slowly decomposed by boiling
potash or sulphuric add into benzoic acid and a brown resin ; is not attacked by boiling
with water and peroxide of lead, till sulphuric add is added, when aldehyde ib eyolyed
and bensamide formed; is similarly decomposed by nitrous add. (Limpricht, Ann.
Ch. Pharm. xcix. 119.)

BentaekloHde of phosphorus dissolyes in hot chloride of benzoyl, and is depodted on
cooling (Gerhardt). According to SchischkoiF and Rosins (Compt. rend. xlri.
M7), wnen equiyalent quantities of the two substances are heated toother in a sealed
tube to 200^ C. for some days, a compound, (TH'OCl*, is formed, which they call o^-
chioride of bemoyi. The contents of the tube are heated in a retort to about 110^ C,
washed fint wiw strong potash, and then with water, and dissoWed in alcohol ; the
addition of water predpitatee the compound as a yellowish neutral oU, hearier than
water, soluble in alcohol or ether. It blackens at 130° — 140*', and cannot be distilled
without decompodtion. It is decomposed when heated with water in a sealed tube, but
not by mere contact with water or aqueous or solid potash : it is also decomposed by
lumiiie nitrie add, etolyiAg nitrous Aimes ; with acetate of silyer in the cold it yidcb
cUoriSe of silyer.

By the action of chlorine on benzoate of ethyl (q. v.) a compound is obtained, baring
the oompositioii C*'H"CA'0*, which may be regardea as a compound of chloride of
beofloyl with tetrachlonmnie ether, 0»H>'01«0* - 2CnB[H)01.0«H«Cl«0. It is a
cokmrieaii liquid, boiling at 188°— 190<> 0., of specific grayity 1346 at lOS^, smells like
chloride of b«azoyl, fbmes in moist air, and is slowly decomposed by water into hydro-
diknic, benzoic, and acetic adds. (Malaguti, Aan. Ch. Phys. [2] Ixx. 374.)

Chloride of benzoyl ^ipears to &>rm a compound with hydride of benzoyL (See
BmsoTL, Htdbzdb ov.)

SubstUuUon^^^rodticts of Ckhrids qf Benzoyl,

Chloride of Chlorobensoyl. C^HK^ « C'H^OIO.CL (Limpricht and y.
ITslar, Ann. dh. Pharm. di. 262). — Obtained: 1. By the action of perdiloride of
phosphoms on dhloiobenzoic add. — 2. By the decompodtion of chlorosulphobenzoie
add:

C*H*a«SO« - C'HH3«0 + S0«.

1 aL. aolphobeDioio add is heated with 2 at. perchloride of phoephonu, as Ions as any-
thing distils oyer ; by repeated rectification of the distillate, a yellowish liqmd is ob-
\ iriiieb boOs at 286° C, and consists ot impure chloride m ehloroben»>yl, which
t be purified by distillation. As obtained by ( 1 ) it is a dear, colourless, strongly-
dng Bquidy vmdi boils at 225° 0. : is slowly deoompoeed by boiling water into
diktobaDBDie and Indrochlorie adds, and quickly by strong aqueous ammonia, into
chlotobiaainida and ddoride of ammonium.

By th« diatfllation of salicylic acid with perchloride of phosphorus Ohiozza (Aon.

oo 4

568 BENZOYL: CYANIDE — HYDRIDE.

Ch. PhyB. [31 zzxtL 102^ obtained a oompound isomenc witii the fofQpnn^ vUdi
may be called chloride o/parachlorobensoyt:

(THW + 2PC1* - C^HKJIK) + 2P0a" + 2Ha

The distillate, which is probably not quite pure, ia a hea^y stronely-rafradiiigliqiud,
with a suffocating smell, and decomposed slowly by cold, immediately by hot YAto;
into parachlorobensoic and hydrochloric adds: when gently heated wiUi aalieykms
acid, it yields hydrochloric acid and salicylide of benzo^ This reaction hu not yet
been explained.

Chloride of mtrobenBoyl CHKaNO* - Cna[<(NO«)O.C!L (Cahonm (IMS),
Ann. Ch. Phys. [3] zziii 339; Bertagnini, ibid. [3] zzziii 466.)-Fonn«d I7 the
action of chlorine in the sunshine on hydride of nitrobenzqyl Also by besting nibo-
benaoic acid with perchloride of phosphorus ; a mixture of the chlorides of pluxphoiyl
and nitrobensoyl distils orer, iniich is rectiiie^%nd the poiiion which panes over
last, is washed with water, dried over chloride of cslcium, and again distilled. It is a
yellow liquid, heavier than, and insoluble in, water, something like chloride of bensojl,
and boilmg at 265^ — 268^ C. It is gradually decomposed in moist air into nitroben*
Eoic and hydrochloric acids. It is simuarly decomposed by strong boiling potash. With
ammonia, it forms nitrobenzamide ; with phenylamine, phenylmtrobemsamide. With
alcohol or wood-spirit, it forms nitrobensoate of ethyl or methyl : it is not decompoted
by ether. F.T.a

BBnOTXiOTAJmiBOV. C^*NO«C'HK).Gy. (LiebigaDdWohler(1832),
Ann. Ch. Phaim. iii 267 ; H. Strecker, ibid, zc. 62.) — ^When chloride of beuojl is dis-
tilled with cyanide of mercuiy, a yellow oil passes over, which may be obtained eoba^
less by rectification (L. and W.) ; after a time, it solidifies to a crystalline mass, which,
after washing with water as long as any mercuiy-^alt is washed out, and dijing vith
filter-paper and over sulphuric acid, leayes pure cyanide of bensoyL It ia a coIooiIm
ciystailine body, which melts at 31° C, ana oyrtallises by alow ooolina; in tabln aa
inch Ions ; it has a pungent odour, exciting tears ; boils at 206° — ^208° C. ; is hearier thaa
water ; is inflammable, and bums with a Tery smokr flame. It is Teiy alowlj deoom-
posed by water in the cold, and not rapidly, even on heating : is decomposed lij aqneooi
potash ; also by ammonia, into benzamide and cyanide of ammonium ; and by one and
hydrochloric acid, into hydride of benzoyl and benzoin. F. T. CI

BBHXOTXn STBBZBB or. Benealdine. Bitter-JImond OH. Oait <i
Picranwl. Oxide of Stilbene, CK*0 » CnBE'O.H. (Liebi^ and Wohler(1883\
Ann. Ch. Pharm. xxii. 1.) — The principal constituent of crude bitter-almond oil, tbe to-
latile oil which is obtained by distilling bitter-almonds with water (see Bima-Auion)
Oil). It is also formed by the decomposition of many oiganic subetanoes. 1. By the
oxidation of amygdalin, amygdalic acid, benaylic alcohol (Cannizsaro, Ana. Ch.
Pharm. Ixxzriii. 180), cinnamon-oil, cinnamic acid (Mulder, Dumas, and Piligot),
and gum-benzoin, by nitric add ; of stilbene and styracene by aqueoaa dnomie add
(Laurent) ; of mandelic acid, s^rone, and ^with seyeral other producta) of casein, al*
bumin, fibrin, and gelatine, by sulphuric acia and binoxide of manganese.— 2. By the
action of hydride of copper on chloride of benzoyl (Chiozza, Compt read. xixtL 631).
— 8. By the rapid diy distillation of a mixture of benzoate and fiynaate «f ealaiiB:

C^»CaO« + CHCaO* - C^«0 + COH)a«

a brown oily liquid passes over, n^enoe hydride of benzoyl is sepsnted by aeid sul-
phite of ammonium (Piria, Ann. Ch. Pharm. c. 104). — I. By the action of nasceat
hydrogen on cyanide of benzoyL Cyanide of benzoyl ia heated gently with hydio-
chlorie acid and excess of zinc ; the cyanide turns yellow, and the zinc becomes eorered
with an unctuous mass, containing hydride of benzoyl, hydrocyanic acid, and bensoiB.
This, when heated with potash, yielcus reddish<jellow oily dtopB^ which, when distiOed,
yield pure hydride of bencoyl (Kolbe, Ann. dL Phann. zcnii 344).--d. By the se-
tion of oxalate of silyer on chloride of benzylene^

CHKH* + C«Ag»0« « C^HW + CO* + CO + 2AgCL

The mixture must be Tery cautiously heated under rock-oil, otherwise a rioIcBt
reaction takes place, attended with complete destruction of the oigame eoBBpomii
(Golowkinsky, Ann. Ch. Pharm. cxi 262.)

Crude bitter-almond oil contains, besides hydride of benzoyl, hydnxTtnie and ben-
zoic acids, benzoin, and benzimide. By submitting the oil to fractional distillatioD,
hydrocyanic acid first passes over, and then toleiably pure hydride of bemoyl; the
other compounds remain in the residue. Pure hydride of benzoyl may also be ob-
tained from the crude oil by seVeral chemical means: 1. By agitating the oil with
powdered mercuric oxide and water (y. Ittner), or with milk of lime and pro(o>
chloride of iron (W. and L.), and distilling. — 2. By agitating theofl with three tote

BENZOYL: HYDRIDE. 569

times ite Tolnme of add snlpliite of sodium of 27^ B., or 1*231 specifie grayitj; dry-
ing by premney or on a porous tile, the crystalline mass which forms after some
hours ; washing it with oold alcohol ; dissolving it in the smallest possible quantity of
water, and decomposing it by a strong solution of sodic carbonate. The oil which
•epazates is decanted and distilled over chloride of calcium (Bertagnini, Ann. Ch.
Phazm. boxT. 186). According to Miiller and Limpricht (Ann. Ch. Pharm. cxl.
136X it is neoessazy, in order to obtain a pure product b^ this method, either to re-
ctystelliae the oystalline compound before distilling it with carbonate of sodium, or
to rectify the liquid which passes over; the portion which distils up to 184° C. is then
free from hydroeyanic acid.

Pure hydride of benzoyl is a colourless, limpid, strongly-refracting liquid, with a
smell leeembling that of oil of bitter-almonds, and a burning aromatic taste. Its
spedAe gravity is 1*0499 at 14*6 or 1063 at 0° C. (Kopp) ; boUs at 179*1<) with the
barometer at 751*3 mm.; yapour^ensity (calc) 3*66. It is soluble in 30 pts. water,
and in all proportions in alcohol and ether ; when free from prussic acid, it is not
poisonous; in the animal oiganism it is converted into hippunc acid (Wo hie r and
Frier iehs, Ann. Ch. Phann. Ixvi. 336). It dissolves in sulphurous acid more easily
than in water, and separates out on evaporating the solution. It is generally regarded
as the aldehyde of the benzoic sroup, since it euibits many of the reactions of an alde-
l^de-y combining with acid smphites of allcali-metals, and oxidising in moist air to
benaoie add ; but it does not reduce silver-solutions.

It bums with a briffht very smoky flame. It may be passed through a tube heated to
doll redness without oeoomposition ; but if the tube be filled with friu^ents of pumice-
stone, it is decomposed into benzoyl and carbonic oxide (Barreswif and Boudault^
J. Phsom. [3] V. 267). Heated to 100° C. in a sealed tube with ferric hydrate (pre-
viously dried at 100°) it is oxidised, and yields a considerable Quantity of ferrous ben-
zoate, part of the non-combined ferric oxide being also reduced to ferrous oxide
(Orager, Ann. Ch. Pharm. cxi. 124). Dry chlorine converts it into chloride of ben-
8oyl and hydrochloric acid; this decomposition is seldom complete, especially if the
gaa be moist^ a compound of chloride ana hydride of benzoyl being formed (see below).
Bromine oonverts it into bromide of benzoyl and hydrobromic add. Iodine does not
attack it. Cold strong nitric acid diasolvee it undeoomposed, and on heating, slowly
oxidises it into benzoic acid : fuming nitric add, or nitrosulphuric acid, converts it into
hydride of nitrobenzoyl (see below). Strong etdphurio acid dissolves it, forming a
red solution, which blackens and gives off sulphurous anhydride when heated. \^th
fWpJUfrtean^iyifrufffitfonnsasul^o-conjugatedadd, sulphomandelic acid(Mit8-
eherlieh, Ldirb. 4** Aufl. i. 163). Wim perohlaride of pkoapharua, it yields the chlo-
rides of benzylene and phosphozyl (C ah ours, Compt rend. xxv. 725). Heated with
eUoride of acetyl in equivalent proportions for several hours to 120° — 130° C. in a sealed
tobe^ it yields hydrochloric and dnnamic adds (Bertagnini, Ann. Ch. Pharm.
e.125):

CHK) + C*HK).C1 - C»HK)* + HCL

"Wiih ndphfdrie acid or sulphide of ammonium^ it yields peculiar products containing
so^phm; and varving acooroin^ to the amount of alkali present, and the medium in
which tile hydride of benzoyl is dissolved. In an akohohc solution, it yields hydride
of thiobensoyl (aee below) ; in an ethereal solution, thiobencaldine* With ammonia
and twdphAde of carbon it ^dds wuifhoeyanobengftlene^ It dissolves potassium^ beoom-
iof( thick and dark, but without evolution of hyorogen (Lowig). When heated with
solid mtosA, it evolves hydrogen, and is converted into benzoate ; with alcoholic potash,
into benzoate and benzylic alcohoL Cyanide of potassium oonverts it into benzoin.
With ammonia it forms various products (Laurent) ; with aqueous ammonia hydro-
bensamide and azobenzoilide; with o^Aolio ammonia am ar in e, benzimic-
aeid, and sometimes, dibensoylimide (Bobson). With ant/tn^ it yidds ben-
xjlene-phenylamine; with urea, benzoyluride.

Combinaiiims, Bens oat e of Hydride of Benzoyls See Bitteb-Alxond Oil.
Hydride of Benzoyl with Chloride of BensoyL C»<H"aO««C*H«O.C'HK)a
(Laurent and Gerhardt» Compt ehim. 1860, p. 123.) — Formed abundantly when
hydride of benzoyl is imperfectly saturated with chlorine, or even when it is treated
with excess of chlorine. The saturated solution, when left to itself in a stoppered
bottle, gradually solidifies into a crystalline mass, which is washed with oold alcohol,
and dried. It forms colourless shining laminn, resembling benzoic add ; melts veir
xvadily, and remains liquid a long time when at rest ; heated above its melting point it
gircs off chloride of benzoyl. When dr^r, it is inodorous, but if moist it gives off fumes
of hydrochlorie add, and smells of hydride of benzoyl. Hot water decomposes it into
besnoic and hydrochloric adds, and hvdride of benzoyl It is insoluble in cold
alcohol ; warm alcohol decomposes it. It is decomposed by strong sulphuric add.

570 BENZOYL: HYDRIDE.

Hydroeyanate of Hydride of Benzoyl OH'NO - CH^O'.CJTH (VoelcW
(1844), Pogg. Ann. Izii. 444). — When crude bitter-almond oil or bitter-alnxnid vatcr
is mixed with hydrochloric add, and eraporated below 100^ C, till it is omiidenUj
concentrated, this compound separates as a yellowish oil, which is washed with vits,
and dried oyer solphuric acid in vacuo. It is inodorous ; boils at 170® C. Spedfio
^▼ity 1*24. Slightly soluble in water, forming a bitter or neatral aolotioii, leadilj
in alcohol or ether. It begins to decompose at 100^ 0., and when boiled is entiielj
resolyed into hydride of benzoyl and hydrocyanic add ; it is similarly deeomposed
by aqueous potash. When evaporated with strong hydrodilorie acid, it takei iq> viler
and forms mandelic add and ammonia :

CET^O + 2H»0 - C»H»0« + NH«.

Gerhardt (Traits, uL 193) mentions a compound obtained by distillmg insltiBe-
bath, a mixture of 2 pts. hydride of bensoyl, 1 pt. cyanide of mercniy, and 1 pt hy-
drochloric add ; it is an oQ which smells like hydride of benzoyl, has aspedfie gnTitj
of 1 '10 ; is somewhat soluble in water, more in alcohol, readily in ether; does not Bolidiiy
at 12^^ C. ; boils at 312^, yielding a distillate which crystallises on cooling.

Hydride of Benzoyl with Chloride of Calcium, — When diy pnlToised
chloride of caldum is added to anhydrous bitter-aknond oil, heat is evolyed, aod a
solid compound is formed, which separates from the liquid in easily decompoable
crystals, apparently containing 2*6 to 3*3 at. CaCl to 1 at hydride of benzoyl (Ek-
mann, Ann. Ch. Pharm. ezii. 151.)

Hydride of Benzoyl with Acid Sulphites of Alkali-metaU, (Bertagnini,
Ann. Ch. Phann. Ixxxy. 183.)

a. With Acid Sulphite of Ammonium, — Hydride of benzoyl dissolves in all propcD*-
tions in add sulphite of ammonium ; but the resulting compound cannot be obtuaed is
the jcrystalline state. The solution dissolves an excess of hydride of benzoyl, vliich
separates out on addition of water. Ammonia renders it turbid, and gFodoauy preci-
pitates a body having the properties of hydrobenzamide. When the £7 ooD^omd is
heated with excess of slaked lime, it yields amarine and lophice. (Gossmann.)

b. With Acid Stdphite of Potassium, — ^When hydride of benzoyl is shaken up with t
solution of this salt of 28® — 30^ Baum6 (specific gravity 1 '24 — 1*26), a crystalline nugm
is speedily formed, which must be dried with filter-paper, and dissolved in dilate boding
alcohol {u boiled too long decomposition takes place) ; the solution on cooling deponts
the compound in shining rectangular laminse. It is very soluble in water, less so in
presence of alkaline sulphites, not at all in a saturated solution of these salts; spu-
ingly soluble in cold, readily in boiling, alcohoL It is permanent in the sir. Iti
aqueous solution is decomposed by boil^g, either alone or with dilute adds, and hj
alkaline carbonates, with separation of hydride of benzoyL

c. With Acid Sulphite of Sodium, C'H«O.SO»NaH.*Aq.— Formed like (*> Snsll
white a^egated prisms, tasting of hydride of benzoyl and sulphurous acid, resdilT
soluble m water, sparingly in hot alcohol, insoluble in cold sIomioL It in^ be kept
in stoppered bottles, ana decomposes but slowly when exposed to the air. When cue-
fully heated in the air, it is decomposed 'Without blackening^ into sulphuroos tthydridi
and hydride of benzoyl, sulphite of sodium remaining; in a stream o! hydrogen, this
decomposition takes place below 100® C. Its aqueous solution is decomposed by boil-
ing, either alone or with adds or alkalis, like that of (6), dso by iodine or chiorine, sodie
sulphate bein^ formed. Nitric add deoon^oses the dry salt in a similar manner. Ito
aqueous solution |ives, with barium-salts, a white predpitate, sohihle in hydroehkiie
add ; it also precipitates lead- and silver-salts : the predpitates appear to ooailna s
portion of the oiL

Substiiuium^produets of ^fdrids of BentoyL

Hydride of Nitrobenzoyl, Nitroberutaldide, CHSP^iy^ « CrHXli'rO)*^-^ (Be^
tagnini, Ann. Ch. Pharm. mix; 269 ; Isxxvi 190.V— When hydride of beniojrl is gn^
dually added to fhming nitric add, or to 16 — 20 vols, of a mixtoze of 1 voL nitrie ud
2 vols, sulphuric add, heat is evolved^ and the addition of water predpitstes hydride of
nitrobenzoyl in yellowish oily drops, which crystallise in a fow days. The yesset nait
be kept cool durin^^ the operation, otJierwise nitrobensoic add will be formed. lbs
crystals sre contaminated by a veUow fotid oil, whence they are porifiMl byprssnxt be>
tween filter-paper, and reerystaUisation from boiling dilute alcoooL

It forms white shining needles, inodorous when pure, witJi a taste like that of hy-
dride of benzoyL It is slightly soluble in cold, reiadily in hot water or aleohoi, \m
so in ether ; dissolves undeoom^osed in nitric, Iq^drochlozic^ <v sulphuric acids, sad
crystallises out as the last solution absorbs moisture from the air. It melts esoly to
u colourless liquid, which solidifies at 46^ C. ; when further heated, it gives off Tipoiiz^

BENZOYL : HYDRIDE. 571

vhieh smell pleasantlT vhen dilul^ but are vtary pungtoit when oonceDtrated. It mar
be Tolatilisea in Bmall quantities without decomposition ; partly even when boiled witn
water, completely when heated in an oil-bath in a stream of gas.

Hydride'of nitrobenzoyl bums with a smoky flame. It does not absorb oxygen from
the air, bnt is readily oonrerted into nitrobenzoio acid by oxidising agents, e,ff.
aqoeons chromic add, or a mixture of nitric and sulphuric acids. Chlorine in sunshine
couTerts it into ohlorins qf nitrobenzoyl (see Bsnzotx,, Cklokidb op). Bromine dis-
solTes readily in fused hydride of nitrobenzoyl, but does not decompose it till heated
orer 100^ C, when a brown resinous mass is formed. Strong hydrocyanio acid readily
disBolTes it, the solution, if eyaporated at once, deposits it imaltered, but after stand-
ing for a few hours, yields on eyaporation, a vificid liquid, permanent in the air, soluble
in hot water, and sepcuating out on cooling, which, when boiled with hydrochloric acid,
yields chloride of ammonium, and another body soluble in water. Cyanide of potas-
sium decomposes it at once, forming compounds which haye not been examined.
With sulpJ^dric acid^ its alcoholic solution forms l^dride of ihionitrobenzylene
(see below). When its solution in alcoholic ammonia is treated with sulphuretted
hydrogen, a semifluid mass is deposited, which consists of a sulphur-compound mixed
with free sulphur; the former is dissolyed out b^ ether, and obtained by eyi^ration as
a yiscdd reddish liquid, insoluble in water or dilute acids, soluble in warm alcohol ; it
is decomposed by heat^ eyolying sulphuretted hydrogen, and when boiled with nitric
add, forms sulphuric add and a yellow resio. Heated with stdphite of amimmiwm
it yields an acid product, readily soluble in water or alcohol. Alcoholic potash
eonverts it into nitrobenzoate in the cold ; aqueous potash requires the aid of heat.
Ammonia, whether dry, a^jueous, or alcoholic, conyerts it into trinitrohydrobenzamide.
When it is gently heated with urea, water is ffiyen off, and the whole solidifies on cooling
into an opaque mass (nitrobenzoylurdd?) slightly soluble in alcohol, readily in alcohol
containing hydrochloric add, being thereby decomposed into urea and hydride of
nitrobenzoyl.

Hydride of nitrobenzoyl combines with add sulphites of alkali-metals, forming com-
pounds of which the following haye been examined :

tf. With Acid Sulphite of Ammonium. C'H»NO«.SO«NH» + ^ Aq.— Hydride of
nitrobenzoyl is dissolyed in a solution of add sulphite of ammonium of 29° Bm. at a
gentle heat, when this eomponnd crystallises out on cooling. It forms small, tran-
8parent» colourless prisms, which grate between the teeth, and haye a bitter and sul-
tJhhous taste; are soluble in water or boiling alcohol, and crystaUise readily from the
utter solution only. It is permanent in the air, though it g^radually acquires a yiolet
tinge. Its aqueous solution is decomposed by boiling, either alone or with adds or
alkalia. With barium- lead- or silyer-salts, its aqueous solution giyes a predpitate of
metallic sulphite mixed with hydride of nitrobenzoyl ; with dichloride of platinum, it
grvea chlaroplatinate of ammomum.

*. With Acid Sulphite of Sodium, (rH«NO».SO«NaH + 6Aq. —Obtained in the
same maimer manner as (a), in yellow scales, which arc rendered nearly colourless by
recrystalfisation firom a little hot water. It is readily soluble in hot, less so in cold
water: eflHoresces in the air : loses its water at 70° — 80° C. ; aboye 90° it is decomposed
giring oflT hydrogen, sulphurous anhydride, and hydride of nitrobenn^l, sulphite of
Bodium remaining behino. Its aqueous solution is decomposed by boiling, especially
on addiixom of adds or aUcalis.

Hydride of Thiobeneoyl. Hydride of Sulphobenzoyl, Sulphide of Stilbene.
Stdpkopicramyl. C'H«S » C'H>S.H (Laurent, Ann. Ch. Phys. [3] L 292. Roch-
lader, Ann. Ch. Pharm. xxxyii 346. Cahours, Compt rend. xxy. 357.) — ^When
1 ToL of bitter-almond oil (crude or pure), is dissolyed in 8 — 10 yols. alcohol, and
1 ToL ralphide of ammonium gradually added, this compound speedily separates as
a mealy powder, which is eadly purified by washing with alcohol. It is also obtained
when an alcoholic solution of hydrobrobenzamide is supersaturated with sulphuretted
faydroraiy and the liquid left at rest It is a white powder consisting of microscopic
gpcanuMS ; is inodorous, but imparts to the fingers a smell of onions ; is insoluble in
water or aloohoL With ether it forms a transparent liquid, which resolidifies on adding
a few drops of aloohoL It becomes soft at 90° — 95° C. After fiidon it solidifies to a
transparent non-ciystalline mass. By dry distillation, it eyolyea sulphuretted hydrogen
and bisulphide of carbon, and yields a sublimate of stilbene and thionessal :

8CPH«S - 2e8« + 8H«S + 2C"H" + 0-H"9.

SMlbene. ThloncnsL

It Imrns with an ofi^dye smell and bright smoky flame. With bromine^ it eyolyes
hydrobromic add, and forms an oily body. Heated with nitric acid, it yields sulphuric
steid and hydride or hydrate of benzoyl ; with sulphuric add, it dissohres, forming^ a
caumine sowtaon, which water decolorises, predpitating yellow flakes; boiled with

672 BENZOYL : IODIDE— BENZOYL-UEEA.

hydroeUorie acid, it evolrefl a little sulphuretted h jdzogen. It is dowiy deeoopoied
by alcoholic potash; water separates an oil from the solution, and adds ctoItb
sulphuretted nydrogen from tne alkaline liquid. It is isomeric with sulphide of
benzylene.

Hydride of Thionitrohengoyl, Sulphide of Nitrobeneylmt. CH'NO'S »
C^H'(NO*)aH (Bertagnini, Ann. Ch. Fhsrm. Izdx. 269).— When analcohdk
solution of hydride of nitrobenzoyl is saturated with sulphuretted hydrogen, thk com-
pound separates as a grey light mealy powder, which is inodorous, but unptrta a dis-
agreeable smell to the fingers. It becomes electric when rubbed. It does not dinolre
in the usual solrents, but melts in boiling waUr^ aggregates together in boiling cbp>
AoZ, and becomes soft and transparent witii ether in the cold. It diaolveB in itzoog
sulphuric acid, and is repredpitated unaltered by water. Stronjg nitric add deoom-
poses it in the cold, dilute nitric aeid on heating, forming sulphuric add and hydride of
nitrobenzoyl. Alcoholic potash dissolves it in the cold, and water predpitatci a
brown substance from the solution. Amtnoniaf whether dry or aqueous, attaeb it,
erolving sulphuretted hydrogen, and forming (probably) trinitrohydiobensumdeL

Oxyiodide of Benealdide, G*iH>*rO (Geuther and Cartmell, Aim. Ch.
Pharm. czii. 1). — ^This compound, which may be reearded as a triple molecole of
hydride of benzoyl (C>>H>H)*), haTin^ 2 at O replaced by 4 at. I. is produced hy the
action of hydriodlc acid gas on hydride of benzoyL Two layers of liquid are thereby
formed, the upper consisting of aqueous hydriodic acid ; the lower, which is oOy, of the
oiyiodide : the latter may be punfied by repeated treatment with water and add enl-
pbite of sodium. It is then obtained as a solid mass, which melts at 28^ C. and
crystallises at 26^ in colourless rhombic plates ; smells like cress ; dissolTes readily in
alcohol and ether, and is insoluble in water. It may be distillfd with water withoot
decomposition ; is not decomposed by add sulphites of alkali-metals, but is neolred hy
alcoholic potash into iodide of potassium, a small quantity of benzoic add, and u
oily body soluble in alcohol, but different from, bitter-almond ofl. By ammoDia, it
appears to be gradually converted into hydride of benzoyL Boiled with nitnte of
silver, it forms iodide of silver, and emits an odour of bitter-almond oil F. T. C

BnZOT&, ZOBIBB OV. CH*O.I. (Liebig and Wohler, Ann. CL
Pharm. iii. 266.) — Obtained readily by heating iodide of potassinm with chloride of
benzoyl ; a brown liquid distils over, which solidifies to a crystalline mass, eoboRd
brown by free iodine. When pure, it is colourless, lamino-crystalline M. leadilj
fusible, always with partial decompodtion; in solubility and general reactions itxe-
sembles bromide of benzoyL F. T. C.

VYTh VaXCBIiOBEDB OV. See BmrroTL, Cblobidh of.

I or. ((7HK)J«S (Liebig and Wohler, foa at)
— ^When chloride of benzoyl is distilled witn finely-powdered sdphide of lead, a
yellow oil passes over, which solidifies to a soft yellow oystalline mass. It hai la
unpleasant sulphurous smell ; is not decomposed by boiling with water or alcohol, aod
but slowly wim aqueous potash ; bums with a bright smoky flame, giring off sol-
phurous anhydride. F. T. C

•UlinoCTJkVZDa OV« See SuifHocTANOBBirzTLia.

C'*N'H" (Laurent (1887), Ann. Ch. Phy& [2] Im
187. Laurent and Gerhardt, Compt chim. (1850), 115. Bobson,ChenLSoc.Qv.
J. iv. 225). — A product of the action of ammonia on bitter-ahnond oil It is tiie
reddue insoluble m alcohol, obtained in the preparation of azobenzoyl^ benekj/Jbw^
and dibenzoylimide {q, vA It is a white powder, without taste or smell, oonsistiBg of
microscopic prisms. It is insoluble in water; requires 300 — 400 pts. boiling acobd
for its solution, and at least as much ether. Fuses when heated, and soHdiflci to i
vitreous mass, in which a few oblique prisms separate. When boiled with alcohol aod
hydrochloric add, it is slowly decomposed, evolving hydrocyanic add. By dry distil-
lation, it yidds an oil, then a sublimate of lophine and amarone, and finally a
carbonaceous residue.

Gerhardt (Trait^ iiL 104) describes this body and benzhydramide under the
name of hydrides of cyanazobenzoyl.

Quadrat (Ann. Ch. Pharm. Izxi. 18), b^ heating sulphocyanoben^lene, oMaised
a resinous mass, which, when exhausted with lUcohoI, left a crystalline rosidiM, in-
soluble in water, almost so in alcohol, to which he assigns the formda 0"H^«

The crystals are permanent at 100^ C. and are not decomposed by nitric arid.

F.T. C

See Benzoin.

WTLf'JIMMJlLm Syn. with Benzocarbaxidb. See Cabbamsb.

BENZOTLUEEID— BENZYL, HYDRIDE OF. 578

C«*H»N»0* (Lanrent and Gerhardt, Compt. chim.

[1350], p. 119). — ^Foimed by the action of vrea on hydride of benzoyl :

4CH*NK) + 8C^«0 - C«»H«»N»0« + 8BP0.

When 6 pts. powdered urea are heated to somewhat below 100® C. with 2 pte. hydride of
benzoyl, the mixtnre becomes liquid, and shortly solidifies to a compact mass. When
cold, this is powdeied, freed from excess of hydxide of benzoyl by etner, and of nrea by
boiline with water; the residne, which is dried at 120^, is bonzoylnreid. It is a white
amorimoas powder, without smell or taste, insoluble in water or ether, soluble in alcohol,
whence it separates on evaporation in amorphous crusts. It turns yellow at 170** C.
g;iire8 off hyaride of benzoyl a few degrees higher, and when farther heated, yields
hydride of benzoyl and ammoniacal water, leaving a yellow residue, which finally
volatilises completely, and is sparingly soluble in alcohoL When boiled with dilute
acids, it is decomposed into hydride of benzoyl and urea. It is not decomposed by
boiling ammonia ; slowly by s£t)ng boiling potash, evolving ammonia and hydride of
benzoyl, and leaving potassic benzoate in solution. Hydnde of nitrobeozoyl yields
with urea a similar compound. (Bertagnini.) K T. C.

Syn. with Bbnzotl-ubba. See Cabbaxidb.

TolyL ToluenyL C*H'. — ^A hypothetical radicle, isomeric with cresyl,
ecmtsined in benzyhe alcohol, toluene, and other compounds. F. T. C.

BMMliKJh, OB&OXIBB HV. Chloride of ^ Tolyl or Tolumyl. Chlorotoluol,
CHTOl (Cannizsaro, Ann. Ch. Fharm. IxvxviiL 129; xcviL 246. Deville, Ann.
Ch. Phys. [3] iii. 178). — Obtained by saturatinff benzylic alcohol with hydrochloric
acid gas whereupon heat is evolved, and theliquid divides itself into two layers, the lower
of which is aqueous hydrochloric acid, the upper chloride of benzyl. Or by passing chlo-
rine into hyaride of benzyl in the dark, expeUing excess of chlorine by a stream of
carbonic anhydride, and rectifying the product It forms a colourless liquid, of specific
gravity 1-117 at0oC;boilsatl70O(Deville); 176<*— 176° (Cannizzaro); insoluble
in water, soluble in alcohol or ether. It is not attacked by aqueous potash ; alcoholic
potaah dieoomposes it on boiling into benzylethylic ether and chloride of potassium.
When boiled with an alcoholic solution of acetate of potassium, it is converted into
acetate of benzyl | of cyanide of potassium, into cyanide of benzyL When heated
in a sealed tube with aloohoUc ammonia^ it yields tnbenzylamine. F. T. C.

aannnnb. erAMZDm or. Cvanide of Tolyl or ToluenyL (yTTS » G^H^CN
(Cannizzaro, Ann. Ch. Fhys. [3] xiv. 468). — Obtained by boiling chloride of benzyl
with a strong alcoholic solution of cyanide of potassium, till no more chloride of
notassium separates out, and distilling the filtrate to remove the alcohoL The residual
liquid separates into two layers, the upper containing cyanide of benzyl, which may be
obtained from it by rectification. It is a colourless liquid, which, by boiling with strong
potash, is converted into toluic acid, C*H'0'. F. T. C.

Ln or. Syn. with Bbnztuo Alcohol (q, v,)
^M or. Hydride of Tolyl or ToluenyL Toluene or Toluol.
Benzoene. Dracyl. C/H« -» C«H'.H. —Discovered bv Felletier and Walter (1837) in
the oily products obtained in the manufacture of illuminating gas from resin ; first
eraminfin by Beville.

Formed: 1. By the action of potash on benzylic alcohol (Cannizzaro, Ann. Ch.
Phaxm. ze. 2^2 ; xcvi. 246) :

ZCnSS) + KHO = (TH'KO* + 2C'H> + 2H«0.

2. Bj heating toluic acid with excess of lime (Noad, ibid, Ixiii. 306) :

C»H«0« - CH* + C0«.

3. By the dry distiUation of tolu-balsam (Deville, Ann. Ch. Phys. [3] iii 152, 168 ;
Mnspratt and Hofmann, Ann. Ch. Pnarm. liv. 9); of dragon's blood (GUnard
andBondault, Ann. Ch. Phys. [3] iv. 274); of the resin of Jnnus mariiima (Pelle-
tier and Walter, ibid, [2] Ixvii. 269); of Burmese naphtha (De la Hue- and
MuUer, PMc. Boy. See. viii. 221) ; of resin-oil (Couerbe, Ann. Oh. Phys. [2] Ixix.
184); of wood ^V dick el, Ann. Ch. Pharm. IxxxvL 334), and of coaL In distilling
coal-tar, the portion which passes over atlOO^ — 115^0. consists of toluene (Mansfield,
Chem. Soc. Qu. J. i. 266). — 4. The yellow oil which separates from crude wood-spirit
on addition of water contains hydride of b^izyL (Cahours, Compt. rend. xxx. 319.)

PreparaHon, — 1. When benzylic alcohol is distilled with four or five times its volume
of stiong alcoholic potash in an apparatus which allows the less volatile products to
run back aeain, alcohol first passes over, then water, and finally, when the residue has
become solid, a mixture of hydride and hydrate of benzyl. This mixture is distilled
by itself the portion which passes over at 116^ C. collected apart and shaken up with

574 BENZYL : HYDRTOE OF.

sulphurio add, the decanted liquid washed with potassie eirboAiU, aod tviee hetified
over phosphoric anhydride. — 2. When tola-balBam, freed hy diatilktion vith inter
from toluene, cinnamein, and a portion of the benzoic acid is subjected to diy distilk-
tion, there passes over, — besides carbonic oxide and anhydride, — ^water, abnndasoe of
benzoic, and a little cinnamie atiid, a heavy oil consisting of amixtare of bensoateof ethyl
(benzoate of methyl, according to Muspratt and Seharling), and brdride of bcozjL
This oil is distilled, and the portion vhich passes over at 18^—140^ G. repeated ne-
tified over strong aqueous potash, and dried over chloride of calamn. Z Kopp
(Compt chinL 16^9, p. 149) purifies the balsam by boiling with aodic caAonate, bdb
the residue with strong aqueous soda, distils the brown solution, decants tlie oil vhith
passes over from the water which accompanies it, and rectifies it repeatedly.>-3. To
prepare hydride of benzvl from coal>tar, the oil which comes over at 100^—120° Cis
mixed with half its weight of sulphuric add and rectified, when a product of eoosfcut
boiling-point is obtained. (Wilson, Chem. Soc. Qn. J. iii 154.)

Hyande of benzyl is a eolouriess, very mobile, strongly refineting Hqiiid, vitii a
smell like benaene, and a burning taste ; spedfic gravity 0*87 at 18^ G. (Deville).
The boiling-point ia variously stated at from lOS^-T (ChurchX to lU^ (Gerhardt);
vapour-density 3 '27 (Deville) ; does not solidify at— 20^. It is jasolabls ia viter,
slightly soluble in alcohol, mortt ao in ether or in fixed or volatile oils. It dJaDhra
most resins, also iodine, forming an amber-red solution, and, when heated, nlphv,
which crystallises out on cooling.

It is not decomposed when passed throu^ a rcdrhot tube tilled with potadi-lime;
It bums with a smoky flame. With eUoriney it evolves heat, and yields serenl sob-
stitution-compounds (see below). With fuming nitric acid, it yields sabstitotion-oom-
pounds (see below). It dissolves in fdming sulphuric actdf forming salphibeoKylk
(sulphotoluic) acid, and sulphibenzyl (Bul{>hotoluol). It is not attacked eitber bj
poiassitwi or hj potash, Wnen digested with sodium, in a closed veaael for foaiteeD
days, it yields two substances, bouing respectively at 97^ C. and 112^. (Chucb,
PhiL Mag. [4] ix. 266.)

Stibstitution-produets of Hydrids of Bensyl.

Deville (Ann. Ch. Phys. [8] iii 178) enumerates seTeral compounds obtained by
the action of chlorine on hyande of benzyl. When the reaction takes plioe in th«
dark, chloride of benzyl (chlorotoluol) is the product (see Benztl, Gc^juds of).
When chlorine is passed through hydride of benzil in bright dayfight, as lone as hy-
drochloric add is evolved, and excess of chlorine removed by carbonic annjdridfl,
hydrocMorate of trieMoroUdttol, C»H*C1« « C'H*CP.HC1, is formed; when distilled it
decomposes and evolves hydrodiloric add. When the action of the gas is still imtber
prolonged, a thickish liquid is formed, together with some crystals. If the Hqnid be sept-
rated, fhrther treated with chlorine wiw aid of heat, and purified by esz^nic aobr-
dride, the product is dihydrochlorate of pentachlorotoltud, C^»a* « (J»H^*.2Hd;
when distilled it evolves hydrochloric acia ; it is soluble in etbar. The crystals are <rt-
hydroehlarate of pentaehlorotoluol, G'HH:!!" » C'H*G1*.3HC1, tfa^ aze purified by reoys-
tallisation from ether, in which the^ are soluble, especially with aid of heat; they an
eolouriess when pure. When the bquid and ciystals together are distilled in a stresa
of chlorine, the distillate bdng repeatedly poured bade again, the whde is gradoally
converted into a silky substance, abundance of hydrochloric add being evolved; this
substance, which is nexchlorotoltiol (hydride of hexchlorobenzyl), GTH^Gl*, is ponfied
by pressure between filter-paper and recrystallisation from, ether ; it is volatile vithoot
decomposition.

Hydride of Nitrohengyl Niirotoluol. C'H'NO'-iTH^NO'.BL (Deville, i«
cit.; Gl^nard and Boudault^ Compt. rend. xix. 606; Hofmann and Mnspnt^
Ann. Ch. Pharm. liii. 220, 224.)--Hydride of benzyl is added to cold Aiming nitric acid
as long as it dissolves immediatdy ; on adding water to the red solution, hjdride of
nitrobenzvl separates as a red liquid, which may be decolorised by washing vitb
water and repeated distillation. It is a nearly colourless liquid, smelling of bitter
nlmonds, with a very sweet and afterwards pungent taste ; specific gravity 1*18 at
160-5 C. ; vapour-density 4*96 ; boils at 226<*— 230° C. Beadily soluble in alcohol or
ether. It is partially decomposed by distillation, completely when passed at a high tem-
perature through a red-hot tube filled with pieces of glass. It bums with a smoky
flame, emitting the odour of gum-benzoin ; when passed over red-hot baryta, it is r^
solved into phenylamine and carbonic anhydride. With friining sulphuric add it fonns
nitrosulphotoluic acid (Church). Aqueous potash dissolves it, forming a red solution,
whence hydrochloric acid precipitates a brown powder ; with alcoholic potash it forms
a black liquid, whence a reddish oil containing phenylamine is obtained by distiHatioD.
Boiled with alcoholic sulphite of ammonium, it forms thiotoluate ox ammonium.
With sulphide of ammonium, it yields benzylamine.

B£NZYLAM£NE. 575

SydriU of Binitrohenzyh Diniirotoluol. C'H«N»0« - C'H»(K(>«).«H. (De-
ville, loc, cit, ; Oahonri^ Compt. rend. zziy. 665.)— Obtained hj boiling hydride of
benzyl with fuming nitrio add, or treating it with nitrosnlphime acid. It cryBtalliseB
{rom alcohol in lustrona, hard, brittle, primnatie needles, which melt at 71° C. and
toUdify to a radiated maaa. It boik at 80(P, becoming coloured, and leaving a resi-
due : when atronsly heated, it yields a sablimate. It is sparingly soluble in water.
It is not attacked by finning nitric acid. Its solution in potash deposits a brown
powder on additicm of hydzochlorie acid. Sulphide of ammonium eonyerts* it into
nitzobensylamina. F. T. C.

JUUimiJU, lOHIBa or. CSDl. ^ (Cannisaaro, 1864.)— When a solution of
benzylic aleobol in buolpliide of carbon is mixed with a solution of phosphoms in bi-
sulphide of carbon, iodine gradually added, and excess of bisulphide distilled ofT,
a hguid is obtained, which izritates the eyes, and is probably iodide of ben^l.

F. T. C.

«MM>lf hAMTW. Toltddine. CTH^ » K.CH'.H*. (Muspratt and Hof-
mann (1846), Ann. Gh. Phaim. liy. 1 ; Noad, ibid, Ixiii 306; Hofmann, ihid. Ixyi.
144; Wilson, Chem. Soc. Qu. J. iii 164; Chautard, J. Pharm. [3] xxiv. 166.)—
Formed by the reduction of hydride of nitrobenzyl by sulphydric acid (Mus-
pratt and Hofmann) : or b^ the action of potash on the yellow resin obtained by
treating oil of turpentine by nitric add. (Chautard.)

Prtparaiion, — 1. A solution of hydride of nitrobenzyl in alcohol saturated with
ammonia, is treated with sulphuretted hydrogen till it smells strongly of the gas, even
after long standing : sulphur then aystalliseB out. The reaction is accelerate by the
application of heat» but the decomposition is never complete. The product is mixed
with water and hydrochloric acid, and shaken up with ether to remove undecomposed
hydride ; it is then evaporated to i, and distilled with potash, when water, ammonia,
and bextfylamine pass over, t<he fast as a heavy oil, which soon crystallisesw The
whole distillate is saturated with oxalic add, evaporated to dryness on the water-bath,
and exhausted with boiling absolute alcohol, which dissolves only the oxalate of benzyl-
amme, which crystallises on cooling. The crystals are washed, dissolved in boilmg
water, and the solution decomposed by strong potash, when benzylamine separates in
oily drops, which collect and crystallise into a radiated mass on cooling : it is purified
by washing and one rectification, or by ciystaUiaation from ether.— 2. The resin ob-
tained by treating oil of turpentine with nitric add, is gradually mixed with aqueous
potash ; the mixture assumes a dark-brown colour, and becomes hot> and when the
reaction has ceased, it is distilled as long as alkaline vapours psss over. The dis-
tillate ifl supersaturated with hydrochloric acid, evaporated to dryness over the water-
bath, and exhausted with absolute alcohol, which dissolves hydrochlorate of benzyl-
amine, and leaves sal-ammoniac undissolved.

Bei^lamine crystallises from dilute alcohol in large colourless laminse^ which are
sparing^ soluble m cold, more readily in boiling, water : readily in alcohol, ether,
wood-spirit, acetone, fixed and volatile oils, and bisulphide of carbon. It smells like
phenylamine, and has a burning taste. It evaporates at ordinary temperatures, melts
at 40^ C. to a colourless, strongly-refracting oil, and boils at 198^. It is heavier than
slightly blues red litmus, but does not redden turmeric ; colours firewood deep

yellow, but does not give the purple colour of phenylamine with chloride of lime, but
only a fiunt reddish tint. With nitric add benzylamine gives a deep-red, phenyla-
mine a deep-blue, colour.

Brvmmt aete on bensylamine violently: when the product is heated, shining needles
■nblime, insoluble in water, soluble in alcohol and ether, — probably tribromobenayla-
mine» It is decomposed by boiling with strong fUtrie aeid, with evolution of nitrous
fkunes; water added to the solution precipitates yellow flakes, which dissolve in
qifc^lMij acod are repredpitated by adds. With aqueous ekromie aotd, it gives a red-
brown predpitate. Whan its vapour is passed over fused pofassiumt vivid combus-
tion ta&ea pUoe, and potassie cyanide iB formed. Oyafiaaen passed into its alcoholic
aolation, yielda eyanobensylamine (see below). — With chloride of cyanogen it
£arma mclobenzylamine (metoluidine) (apd below.) With bromide or iodide of
ttJkylj it yields bensylethylamine (see below).

OimbiiuUions. L With Acids. — ^Benzylamine combines with adds, forming crys-
talline salts, which are mostly inodorous and colourless, but quickly become rose-
coloured when exposed to the air : they are decomposed by alkalis or alkaline carbonates,
bt^uylamine beins separated as a crystalline curd. The chloraurate^ AuCl'0^**N,
separates as a thidc precipitate, which soon aggregates to a crystalline mass, when the
hjdrochlorate is mixed with trichloride of gold: it melte in water at 6(P — 60^C., dia-
aolves when further heated, and crystallises on cooline in fine yellow needles. The
cUoroplatinaU^ FtGl'CTH'^N, separates as an orange-yeUow crystalline pulp, when the

576 BENZTLA31INE.

hydrochlorate is mixed with bicbloridi) of platmnm : it is washed with etha^aleohol
and dried in a water-bath. The chloropaUadate is simihur in appearance. The lijfin-
chlorate, C'H**NCI, is deposited in white ctystalline scales, becoming yellow on
exposure to the air, when a solution of benzylamine in hydrochloric add is enpontod
and cooled : it is readily soluble in water or aloohol, sparinglj in ether, forming add
solations : when gently heated, it sublimes like sal-ammoniac. The witnxU, photpkaU,
and sulphite are ciystallisable. The acid oxalate, G*0\G^**N.H -i- ii4, is obtained
by mixing an alcoholic solution of benscylamine with excess of oxalic add, in delicate
silky neemes, soluble in boiling water or alcohol, insoluble in ether. ORie ttdphaU^
80*(C'H**N)', is obtained when a few drops of solphuric add are added to an ether^l
solution of benzylamine, as a white ciystamne precipitate, which may be washed with
ether : it is readily soluble in water, sparingly in alcohoL With cuprie nlpkaie or
chloride, benzylamine gives a greenish crystalline precipitate ; with niirete of tiller,
a white precipitate, which soon blackens; it precipitate ferric hydrate from fenie
chloride.

2. With Otanoobit,- Cyanohenzylamine; Cyanotoluidine. (THHSP ** CW.CS.
(Hofmann, loc. cit, C^em. Soc. Qu. J. i. 170.) — ^When cyanogen is passed through an
alcoholic solution of benzylamine, the red-brown solution deposits, after some boon, a
crystalline mass, whence hydrochloric acid extracts cyanobenzylamine, which is pre-
cipitated by potash from the hydrochloric add solution. It is homologous with
cyanophenylamine, which it dosely resembles, only being less soluble in alcohol or
ether.

Meloheneylamine. Metolvidine, C'»H»*N» « C'Bi'K.C^^CyN. (Wilson,/*.
cit.) — When the vapour of chloride of cyanogen is passed over fused bem^Iamioe,
heat is eyolved, and a resinous mass obtained, consisting of hydrochlorate of metoloi-
dine ; this is dissolved in water acidulated with hydrochloric add, filtered, and mixed
with potash ; and the white precipitate thus produced, is boiled with potash, washed, sad
reciystallised from alcohol. Crystalline laminae, sparingly soluble in cold, somewhat
more in boiling water; crystallises best from a mixture of water and alcohol; readilj
soluble in hydrochloric acid : the solution gives with dicUoride of platannm, a dail-
yellow predpitate of chloroplattnate^ which is insoluble in water or alcohol and maj
be dried at 100° C. It is homologous with melaniline (melophenylamine).

Secondary and Tertiary Aminss containing Benzyl,

Beneylethylamine. Ethyltoluidine. C»H>"N - N.C?»H^C»H».H. (Morley aal
Ab el, Chem. Soc Qu. J. vii. 68.) — ^Benzylamine is heated with iodide of ethyl in a sealed
tube for two or three days in a water-bath; the product fr«ed from excess of iodide I7
heat ; the resulting oil, which is hydriodate of benzylethylamine, distilled with stroog
potash, and the distillate rectified over solid potash. It is a colourless oil with a peculiar
smell : specific gravity 0*9391 at 16^-6 C. ; boils at 217° The chloroplatinate is a pale-
yellow crystalline compound, soluble in water or alcohol, less so in ether: at 100'' it
becomes dark, and is aecomposed. The oxalate and sulphiUe are crystalline.

Bengyldiethylamine. Biethyltoluidine. C'ff'N « N.C^H'.((?H*)«.-PrepiKd
in the same manner as the foregoing compound, benzylethylamine being snbstitnted fct
benzylamine. A colourless, odorous oil : specific gravity 0*9242 at 15*5 C., boils at 229^.
The chloroplatinate is a resinous non-crystalline mass. The hydriodate forma oilj dropi
which crystallise when touched with a glass-rod ; is very soluble in water, deeoanpoKS
when exposed to the air, or in contact with alcohoL

Benzyltriethylium, C"H««N « N.CHVC^H*)*.— Known only in ooanhinatioa
with adds. When benzyldiethylamine is heated with iodide of ethyl to 100^ C. in a
sealed tube till crystals are formed and excess of iodide of ethyl is removed bj die*
tiUation, iodide 0/ benzyltriethylium remains as a heavy oiL This is decomposed
by heating with oxide of silver, yielding a solution of Aydrdte of benzyUrieth^v^
N.C'H'(C?'H»)«.H.O, which is strongly slkaline, has a bitter taste, and predpttates
most metallic salts. The chloroplatinate is insoluble in cold, solnble in hot water,
whence it oystailises in fine needQes ; it loses platinum on recrystallisation.

Nitrohenzylamine, Nitrotoluidins. C*H«N»0« « N.C»H«NO*.H«. (Cahoari
Compt. rend. xxx. 820.) — ^Formed by the action of sulphide of ammoniom on hydride
of dinitrobenzene ; it crystallises in yellow needles, n>rms definite componnds with
nitric, hydrochloric, sulphuric, and phosphoric adds : yields alkalamidea with the
chlorides of benzene and cumyl.

Tribenzylamine. C«»H«N - N.(0»Hn«. (Cannizzaro, Cimento, iii 897.)-
When chlonde of benzyl is heated with alcoholic ammonia to 100° C. in a sealed tube,
ammonia passed into the cooled product, the resulting predpitate exhausted with
ether, and the ethereal solution evaporated, this compound is obtained in shining
laminae, which melt at 91*3^ C. to a colourless liquid, and at 360^ Toiatiliae with

BENZYLENE. 577

ptituJ deoom^ositiofn. It is sparingly soluble in cold w&ter or alcoliol, more so in bo3-
ing aloohol, stUl more in ether, forming alkaline solutions. The hydrochlorate crystal-
lists in needles from hot water. The ehloroplatinate forms orange-needles. F. T. C.

CH*. — A hypothetical diatomic radide, of which, according to

being that the fininer readily decomposes, yielding water and the latter compound,
'Mai in turn is readily eouTerted into its isomer, hydride of benzoyl. Several oom-
poond efthere have, howerer, been obtained, representing the alcohol in which the
2 atoms of basic hydroffen are replaced bypoeitiTe or neeatiTe organic radicles (see
BnBRiiKfio EmsBs). Hydrobenzamide C^H^I^, should probably be regarded as a
teitiazy diamine containing this radide. K^CTH*)*. F. T. C.

BBnr^nra, CKbOmna or. Chlorobenzol. CmKHK (Cahours (1848),
Ann. Ch. Phys. FS] xxiii. 129. Wicke, Ann. Gh. Pharm. di 866.) --When hydride of
bena^l is brought into contact with a dight excess of pentachloride of phosphorus, a
fivelT action takes ^lace; and i^ when this is over, a gentle heat be applied, oxychloride
of pho^horns distils over at about 110^ C, and chloride of benzylene at about 206°.
Hie latter is washed with water, dried over chloride of caldum, and rectified. It is a
edourless liquid, smelling fiuntly in the cold, but strongly when heated ; insoluble in
water, soluble in alcohol or ether: spedflc gravity 1'246 at 16°: vapour-density
(expt.) 6*695 ; boils at 206° — ^208°. It is not oxidised by exposure to ue air, or to
ox^rgen. When heated in a water-bath with alcoholic potasht more slowly with
aqueous potash to 100°, in a sealed tube, it yields chloride of potassium and hydride
of bensoyL Ammoftia, whether dry, aqueous, or alcoholic, does not act upon it in the
cold: idien heated in a sealed tube to 100° with an ammonia-solution, it yields
chlaride of ammonium, and bitter-almond oiL It is not attacked by dry cyanide of
]^ota9sium at 100°. Heated with alcoholic stdphocyanate of potassium to 100° in a
sealed tube, it yields chloride of potasdum, and an oil smelling like oil of mustard.
Alcoholic nitrate of sUver deprives it of all its chlorine, hydride of benzoyl being formed.
Alcoholic Jufdrostdphate of potassium converts it into sulphide of benzylene.

Gerhardt (Trait^ iii. 167) r^Lrds this compound as hydride of benzoyl in which
oxygen is replaced by chlorine : Wicke, however, shows condudvely that it possesses
none of the properties of an aldehyde. f . T. 0.

JMUililMOrB, mawSDM or. Sulphobenzol, CH*S. (Cahours, loc. cit.)
— Formed by the action of alcoholic sulphydrate of potassium on chloride of benzylene,
and zeciyslailised from boiling alcohol, in which it is readily soluble. White pearly
scales, insoluble in water, which mdt at 64° C. and crystallise on cooling : when f^her
heated, it is partlv volatilised, and partly decomposed. It is oxidised even by dilute
nitric add, with mrmation of sulphuric add, and a substance soluble in alkalis, which
erfstalliaeB in shining yellow scales. F. T. C.

ir.Cna*.C^». (Laurent and Gerhardt, Compt chim. 1860, 117.)— -When perfectly
dry hydride of benzoyl is mixed with about its own volume of perfectly diy phenyl-
amine, water separates out^ and a crystalline mass forms after a time (sometimes not
until water is added) : this is pressed between filter-paper, and recrystallised from hot
alcohol, or purified hj rectification. It forms beautifu shining lamins, without taste
or ameU, insoluble in water, soluble in alcohol or ether. It is easily fusible, and boils
at a very hieh temperature without decompodtion. Bromine acts with violence on its
alcoholic aomtion, forming after a time ciystals of tribromophenylamine. With cold
faming nitrie acid, it forms a dark-green solution, whence water predpitates hydride
of benzoyl, nitrate of phenylamine remaining in solution : stdphuric acid decomposes
it in a similar manner, forming a yellow solution. It becomes liquid by contact witii
aoetie ot hydroehloric acid : the latter dissolves it on boiling, wiUiout decomposition.
It la scazody attacked by boiling potash. F. T. C.

Salts or ethers of Benzylene. (Wicke, loe, cit)

a. Ethers containing a Boeititfe Badide,

Ethkb. Methylate of BensyUne, Off «0« « C'ff.(CH»)«0»
— A mixtore of 1 at chloride of benzylene with a solution of 2 at. sodium in abso-
]at« methyUc alcohol, is heated for some hours, when chloride of sodium separates in
Miundance ; the methylic alcohol is distilled ofl^ and the residue mixed with water,
vfaen the ether rises to the surface, and is removed with a pipette, dried and rectified.
Jt 10 a transparent, colourless liquid, heavier than water, with a pleasant smell like
tfast of geraninms; insoluble in water, soluble in wood-spirit, alcohol, or ether. It
JtaSiB at 208° C, leaving a brown reddue arising ^m decompodtion.
VouL PP

578 BENZYLENIC ETHEES— BENZYLIC ALCOHOL.

ETBTLBBiZYZJDao Ethbb. Eth^loU of Bmeylens. C»Hi*0* « CnS^GV)F.O*.->.
Prepared precisely like the forjBgoing compoimd, ethylic being oabstitated £ar metliylie
alooaoL ft boils at 222^ 0. : in other reBpects it reeemblee 5ie methyl-compoqnd.

Ajctlbshztlbnio Ethbb. JmylaU of Bensylene. C>'H?K)« - (7H«.((>ff»)».0*^—
Prepared like the preceding oomponnda : bat the ether must be 8e|Mmted by feactiooal
distillation, not by addition of 'water. It is a slightly yellowish oil, smeilling like fbsel-
oil, and lighter than water: it boils, not without considerable daoompootion, aboot

2920 a

b. EikeneontaimnffJeidBadicUt:

The only one of these which has been obtained perfectly poie, and in the etystalfine
form, Ib

AGSTOBBorxmno Etheb. AoetaU ofBengylene. C"ff*0* « C^«((?BPO)*.0»—
1 at. ehloiide of bensylene is triturated with rather more than 2 at dry acetate cf
silver, and the mixture heated very gently in a flask; the reaction is so yiolent Uiat
it is well not to nse more than 10 grm. silTer-salt at a time. The product, when eod,
is repeatedly extracted with ether ; the extracts are distilled in the water-bath ; and
the yeUowish oily residue is washed with weak soda-solution and with water, then
redissolved in ether, and left to erapoiate. A yiscid oil ia thus obtained, in which
aystals gradually Ibnn, until at last it solidifiesoompletely. It forms small white shining
dystals, bdonfling to the monodinie system, insoluble in water, solnble in alcohol or
ether, whence it separates on evaporation as an oil, which often does not crystallise tffl
agitated. It melts at 86^ C, and crTstaUises on cooling : begins to boil at 190°, the
temperature ffradually rising to 240^ , and yields a distillate consisting of aeelic an-
hydride and nydride of bensoyL Heated with aqueous potash or duute sul^uiie
acid, to 100° in % sealed tube, it is converted into acetic add and hydride of botiojfl:
with aqueous *"»»nA«ia. nnder the same circuIn8tancei^ it yields acetamide and hytno-
benzamide.

BsKiOBBMZTUDnc Ethhr. BmsfOoU ofBeneyUnt, C«»BP«0« « CTH*. (C*EPO)«.0».—
Chloride of benzylene acts violently on benzoate of silver, with evolution of heat: the
ethereal extract of the product yields on evapOTation a viscid, brown, non-cryBtalliflable
mass. With alcoholic potash it forms immediately a solid mass of potassic bensoate^
mixed with hydride of benzoyL

SucczNOBBMZTLHNic Ethbr. Succtnots of Bmzvlene, C"H'*0* « C^«,C«H*O*,0*.
— ^Pr^pared like the foregoing compounds : its ethereal solution is decomposed by
evaporation or by washing wiui dilute soda, into succinic acid and hydride of beiwoyL

SnjPHOBBKZTUDno Etheb. Sulphate of Beneykne, CH^O««CTI^S<>*.0*.— Pre-
pared in the same manner. It is a red-brown, non-crystallisable oiL

Vaubobbnztlbnio Ethbb. Valerate of BeruyUns, (?»H^*»C»H«.(C*H^)).K>.
— Obtained like the acetate. On evaporating its ethereal solution, it remains as a thick,
yellow, non-crystallisable oil, which is decomposed by distillation into valerianic add
and hydride of benzoyL

Chloride of benzylene acts so violently on oxalate of silver, that no definite prodoct
can be obtained. P. T. (X

(See BBRnLAMiNB.)

LT&XO A&COKO&. Hydrate of Benzyl, Bmzcio AkohoL
AlcvkoL C'HH)»(7H'.H.O. (Cannissaro [1853], Ann.Ch.Phann.lxxxviiLl29; x&
262; xdi 113; xcvi. 246; Scharling, ibid, xcvii. 168.)— Formed : L By the action
of alcoholic potash on hydride of benzoyl:

2CTaTO + KHO = CEH} + C»H»KO*

'When a mixture of pure hydride of benaoyl with its own volume of absolute akohQl is
mixed with 3 — i vols, alcoholic potash, of spedfie grarity 1^)2, heat is evolved, and die
whole solidifies to a crystalline magma. The potassic benzoate is dissolwd out with
hot water, the alcohol distilled oil^ the residue mixed with water till it begins to be
turbid, and then shaken up with ether. The brown oily rendue obtained by eva-
porating the ethereal solutum, is dried over fused potash, and repeatedly rectified. —
2. When acetate of benzyl, obtained by boiling chloride of benzyl with ucoholic ace-
tate of potassium, is boiled with strong aleohoUc potaah, and the alcohol distilled oS,
the rraidual liquid separates into two layers, the upper of which contains beozjJiie
alcohol, which is separated by fractional distillation. — 3. Scharling has shown that
tbe substance known as perttww, obtained by the action of potash on rinnamdn, is
benzylio alcohoL

It m a colourless, strongly-refracting oil, with a fidnt pleasant smell : specific gravity
1051 at 14^*4 a, 1*063 at (P (Kopp): vapouMlensity (expt) 8*86 : boils at 206^

BENZYLIC ETHER- BERBERINE. 579

imdeF preBsure of 751*4 mm. (Kopp.) It is insoluble in water: soluble in all pro-
portions in alcohol, ether, aeetic acid, or bisulphide of carbon.

When its yapour is passed through a red-hot tube filled with spongy platinum, ben-
sene with other compounds is formed. It is couTerted into hydride of benzoyl by
osjfgeny in presence of platinum-black, or by nitrio add : aqueous ehroTnie add converts
it into benaoie acid. With strong sttlpkuno add, fkotplunrio anhydride^ qt chiwride of
sme^ it yields a brown resin, insoluble in water, alcohol, or ether (probably stilbene).
Fused boric anhydride converts it at 100^ — 120^ C. into benzyUc ether, at a higher
temperature into stilbene (or benzylene ?) : with fluoride of boron, it yields the same
pioducL Distilled with strong alcoholic potash, it yields hydride of bensyl (q. v.)

F.T. C.

BHBTR&ZO STBBft. C'^H^^O «. (CH'^'.O. (Cannizearo, Ann. Ch. Pharm.
xcii. 116.) — ^Fused and pulverised boric anhydride is mixed into a paste with benzylio
alcohol ; tiie mixture is heated for some hours to 120^ — 125^ C. i and the resulting hard
brown mass is treated with water and a solution of alkaline carbonate, when a greenish-
brown oil rises to the surface. When this is distilled, benzylic alcohol passes over below
SOO^, and benzylic ether at 300^ — 316^ : the residue contains stilbene. Benzylic ether
is a colonriess, slightly fluorescent oil, boiling at 300^ — 315°. When heated above its
boiling-pointy it becomes yellow and is decomposed, yielding resinous stilbene, hydride
of benzoyl, and a light oil, which is probably hydride of ben^L With phosphoric
anhydride or sulphuric acid, it yields the same product as benzylic alcohol.

Ethyl-bensylic Ether, C»H'*0«»C^'.C«H*.0. (Cannizzaro, Cimento, iii. 397.)
— Chloride of benzyl is distilled upwards with alcoholic potash, and the resulting liquid is
decanted from the chloride of potassium, and mixed with water, when it separates into
two layers : the upper of these is distilled, and the portion which comes over at 185° C.
dried over chloride of calcium and rectified. Colourless, mobile liquid, with a pleasant
smell; lighter than, and insoluble in, water: boils at 185°.

For the compound benzylic ethers containing acid radicles, see Acbtio and Benzoic
AccDS. F. T. C.

li'BR A U1HTB< A hydrated sesquiphosphate of iron occurring at St. Benigna in the
cirde of Beraun in Bohemia, together with cacoxene and Dulrenite. It forms ra-
diated or laminar masses, with perfect cleavage in one direction ; imperfect at right
angles to the first. Specific gravity 2*878. Hardness 2*0 to 2*5. Bather brittle.

JMBBSaWOrB. C"H»NO* (?)* An organic base discovered in 1837, by
Bnchner (Ann. Ch. Pharm. xxiv. 228), in the root of the barberry {Berbcria vulaaris),
and since found in other roecies of Berberis growing in Mexico and in India. It has
also been obtained by Bodeker (Ann. Ch. Pharm. Ixvi. 384 ; Ixix. 40), from colombo-
root (^Coeculus palmatue); by Perrins (Ann. Ch. Pharm. Ixxxiii. 276), from the
oolorabo-root of Ceylon (Meniepermum feneetraium); and by Stenhouse (Pharm.
J. Trans, xiv. 455), in a yellow bark used as a dye by the natives of Abeoconta in
West Africa.

PrepartUiofi. a. From Barberry-root — The root is exhausted with boiling water;
the extract concentrated by evaporation, and treated with warm alcohol of 82 per
eent,; the solution filtered; the greater part of the alcohol distilled oif; and the
residoe left to itself in a cool place. Yellow crystals of berberine are then deposited,
and may be purified by recrystaUisation from boiling water or alcohol. The root con-
tains about 1*3 per eent of berberine. ( Bu chn er .)

b. FYom Cdombo-root — The dried alcoholic extract of the root is treated with hot
water ; the filtered solution neutralised with hydrochloric acid ; and the liquid again
filtered, treated with excess of hydrochloric acid, and left at rest for Fome days. It
then deposits a crystalline sediment of hydrochlorate of berberine, which is dissolved
in a BDuJl quanti^ of alcohol and reprecipitated by ether (Bodeker \ For further
pnrifieatioin, the hydrochlorate is converted into a sulphate ; this salt is reciystallised
and dried at 100° C. ; the aqueous solution decomposed by baryta-water ; the excess of
baryta removed 1^ passing a stream of carbonic acid through the liquid, then filtering,
evaponating nearly to dryness, and digesting the residue in alcohol. The alcoholic
aofaftion is then precipitated by ether, and the precipitated berberine recrystaUised
from water. The same mode of purification may be adopted with berberine obtained
ttcm. barbeny-root (Fleitmann, Ann. Ch. Phaim, xxiv. 228.)

Properiue. — Small sill^ needles or concentrically grouped prisms of a light yellow
eoloor. Odourless, but has a strong and persistently bitter taste. Sparingly soluble
in water and alcohol when cold ; easily at the boiling heat ; insoluble in ether. Oils,
both frtty and volatile, dissolve it in small quantity.

The crystals heated to 100° C. give ofi* 1926 per cent (5 at) water of crystallisa-
tton, sad the residue contains 66*7 to 67*4 carbon, and 5*6 to 5*7 hydrogen, agreeing

* Or rather C»H»?NO< (Perrins, Chem. Soc. J. xr. 339). See Appkndix. ^

pp 2

580 BEBENGELITE— BERGAMOT, OIL OF.

nearly with the fomnla 0«»HmNO».JHH), or C^B^NO^KHO (Fleitmann). The
remaining water cannot be expelled without further decomposition. According to
fleitmann, the aahydroiu salts of berberine contain the group C*^IP*NC^ aasociated
with acids: «.^.the hydroehlorat^ «« C*^H^*NC^.Ha; berberine dried at lOO^ ii
C*^WN(^.2H0, and the crystals contain C^IP*NC^.2S0 + 10 aq. These formnla
are, howeyer, by no means probable, and farther examination is required to detennina
the rational constitution of the base. The fonnula C*>H' VO* or C^S^HO^ is tbt
Bu^estedbyGerhardt (Tzait^ iy. 205).

JBerberine melts at 120<> C. to a resinous mass, without loss of weight. Between 160°
and 200^ C. it giyes off yellow odorous yapours, which condense into a solid body in-
soluble in water, but yezy soluble in alcohol, and leayes an abundant residue of charaMl
Ammonia oolonrs berbenne yellow-brown, and dissolyes it in nearly the same pzopo^
tions as water. Berberine boiled with caustic potash-ley melts, and is conyeited into
a resinous substance^ sparingly soluble in water, easily in alcohol. According to
Bodeker, berberine distilled witii milk of lime or hydrate of lead, yields chinohne.

The salts of berbenne are, for the most part^ sparingly soluble in water ; many of
them may be prepared bytreating the hyd2x>chlorate with a salt of potassium. Btfdro-
chlorate of berbeHne, C*W*NO*.Ha + 2H*0, crystallises in slender yellow needles,
which giye off their water of crystallisation (8*66 per cent) at 100<^ C. With sulphide
of ammonium containing exeess of sulphur, it forms a foetid brown-red precipitftte con-
taining sulphur. A hot alcoholic solution of the hydroehlorate mixed with a conc^
trated alcoholic solution of glycodne, yields on coolings a mass of slender orange^lomw
needles, sparingly soluble in water, which appear to contain C**H'*NO*.HCLC'H*N0v)
The chloropUUinaU of berberine^ C"H»»NO».HCLPtCl« (?) is a yellow precipitate neariy
insoluble in water. The chloraU, C«»H"N0*.HC10» (?) is a buUqr yeUow precipitate
obtained by mixing the hydroehlorate with chlorate of potassium. It is moderately
soluble in pure water, sparingly soluble in saline liquids. The acid ekromaU,
C«H»*NO».Cr«H«0* (?) is a bulky yellow precipitate, sparingly soluble in water, ob-
tained by mixing the hydroehlorate with add chromate of potassium. It is ^^
soluble in hydrochloric and sulphuric acids. When strongly heated, it decoinpw«
suddenly, yielding a laree quantity of the yellow substance produced in the dry dis-
tillation of berberine. Nitrate of berberine forms yellow crystals sparingW soluble in
cold water. The acid sulphate, C*»H"NO».SO*H«(?) is deposited after a while in smaU
yellow crystals on adding sulphuric acid to a dilute solution of the hydroehlorate. ^

BBBSVOBXJnra. Berengda resin* — ^A bituminous mineral found in the provmoe
of St. Juan de Berengela in Peru, about one hundred miles from Ajrica, where it occois
in amorphous masses of considerable extent, forming a sort of pitch-lake, like tiist oi
Trinidad (p. 426). It has a conchoi'dal fracture, a dark brown colour, inclining to
green, and waxy lustre ; yields a yellow powder ; has a resinous unpleasant odoor ana
a rather bitter taste. Melts below lOQO 0., and after cooling remains soft and unctuoos
at ordinary temperatures. It dissolyes readily in cold alcohol and in ether. It is ^^
for caulking ships. According to Johnston's analysis (PhiL Mag. [3] ziy. 87)» its
formula is C~H»0*.

BBRBBXXa is a fine-grained granite containing pyrites, occurring at Beresowsk m
the Ural, in the rocks in which the gold yeins are found.

BBSOJkMOT, Onb or. A yolatae oil obtained hy pressing the rind of a varie^
of orange. Citrus berganUa, cultiyated in the south of Europe. The oil thus obtains
is light-yellow or sometimes ereenish or brownish-yellow ; mobile, with a veiy ^S**®* « J
odour and aromatic somewhat bitter taste. Specific grayity 0'869. It geperaiY
exhibits an acid reaction, arising from the presence of a small quantity of acetic aci
It solidifies a little below 0^ 0., and at ordinary temperatures deposits, after a wim<!»
a soUd camphor or stearoptene.

Bereamot-oil is a mixture of two essential oils, the more yolatile of which is isomen
with oil of turpentine and oil of lemon, C"H"; but it is difficult to separate this on
by simple distillation. .^

The less volatile portion which, when rectified, boils at ISS^ a and has a den«J7

of 0'856, contains oxygen, and according to Ohme (Ann. Gh. Pharm. zxzi.

316),

has the composition of a hydrate of oil of lemon, 3C»*H".2H«0. According w
Soubeiran and Capitaine (J. Pharm. xxyi. 68, 609), this portion of the oil is no*
of constant composition, but yields by fractional distillation, oils continually ^.^^
ing in amount of oxygen, from 3*37 to 16*14 per cent (perhaps the oil was ^^^^
during the distillation). They find also that the first portions turn the l^^-^-i^
polar^tion of a luminous ray to the right, but that the subsequent portions esiu
lew and less of this power, and finally none. ^^

Ohme's rectified bergamot-oil is not altered by caustic potash. Its ^^^^^^^^
oyer red-hot lime yields a large quantity of benzene. It absorbs hydrochlonc s^

BERTHIERIN— BERYL.

581

010 abandantly, ftnniiig s liquid eomponnd, which, after being shalceii np and diertilled
with vater, has the apedfic gtmtj 0896 ; boila at 183<> C, and contains C^R^**CIH),
at 60"H»«.2HCiH«O.

Beigamot-oil placed in contact with phosphoric anhydride becomes heated, and
afterwards yields by distillation an oil nneUing like oil of tnipentine» and havins
exactly the composition G'*H". The residne of the distillation contains a coi^ngated
add, phoapkobergamic acid^ which forms soluble salts with calcium and lead.

Bbboamot-Caicfhob, BerffopterUf Stearoptene of bergamot-oU^ is a solid sub-
Etance deposited by crude oil of bergamot after long keeping. It dystallises in
needles, melts at 206® C, and volatilises without decomposition. It is odourl.ss and
dissolTes in boiling water, alcohol, and ether. Strong sulphuric acid colours it red.
Heated with nitric add, it yields oxalic acid. It gives by analysis about 66-2 per cent,
carbon and 3*8 hydrogen, numben answering to the formtila CH*0', but the ra-
tional formula is not yet determined. (Mulder, Ann. Ch. Pharm. xxxi 70; Ohme,
he, dL)

If ■■»■■■ My»PT^g_ xhe name given by Beudant to a ferruginous mineral occurring
in small grains, resembling iron-spar or brown iron ore; but whether it is a definite
species ot a mixture is not decid^y known. According to Berthier, it contains 12*4
per cent. sHica, 74*7 protoxide of iron, 7*8 alumina, and 5*1 water. The same name
18 also applied to a mmeral from Hayanges near Metz, of gre^h-green or liver^brown
colour, wnidiy under the microscope, appears like an oolitic ro^ consisting of a
Ijieenish amoiphous mass^ oontainmg innumerable small flattened needles of brown
iron ore.

or »^T^»^>«Mi*i'i'M- These names are applied some-
what indiscriminately to three minerals, containing protosulphide of iron, together
with trisolphide of antimony. — a, 8Fe^.2Sb^'. Found at Chazelles in Auvergne,
aystaUine or m^psive, with imperfect deavage in several directions. Specific gravi^
4*284: hardness 2*0 to 3*0. £:on-black or dark steel-grey. Opaque with metallic
losbv. Fuses readiljr before the blowpipe on charcoal^ yielding antimonial fumes
and deposit, and leaving a black magnetic slag (Berthier, Ann. Ch, Phys. [2] xxxv.
351). — 6. 8Fe*S.4Sb^'. Found in a mine near ChazeUes. Fibroos, with granular
tzansverse fractore, almost destitute of lustre (Berthier, Pogg. Ann. xxix. 458). —
a Fe^Sb^ or FeSbS*. Found at Anglar in the D^partement de la Crease. Crystal-
Ibe^ composed of fine paialld fibres. Sted-grey, inclining to bronze (Berthier).
Minerals naving this oompodtion are also found in other locdities.

BflB.VSO&UnRA MaLOHTiBli A Brazilian tree bdonging to the order Lecy*
Uttdaeem. The kernels of the fruit, called Brazilian or Pava nuts, contain sugar, gum,
and a pale yeUow odourless fat oil, which solidifies at 0^ C, and contains stearin,
palmitin, and elain. (Caldwell, Ann. Ch. Pharm. xcviii. 120.)

BJMfcgJU, 3aP0 . A1«0' . 6SiO< Si'CPAlH)'.— A mineral spedes comprising several
varieties, among which are found two very beautiful and oostlv gems, viz. emeraldf and
e^uamarins or precious beryl. The crystals bdong to the hexagonal system, being
regular six-dded prisms varurasly modified, sometimes by the truncation of tibe latend
edges, at other tunes of the terminal edges. The most ordinary combinations are
00 P . oP and ooP . pP . P. {Jig, 98) ; sometimes, however, much more complicated
modiHestLosis occur, like fig, 99, composed of the hexagonal prism oo P. the terminal

Fig, 98.

JP\^. 99.

•p

«»p

£Me op, the primarv hexagonal pyramid P, a sharper hexagonal pyramid of the first
order 2P, a pyramid of the second order 2 P 2, and a ^rmmetrical 12-dded pyramid
8 P|* whose fiMses (denoted in the figure by e) replace the combination-edges between
2F2, and oo P. The prismatic faces are often deeply striated in the vertical direo-

pp 3

582 BERYLLIUM— BETA.

tioxL CleaTage tolerablj perfect^ poraUel to oP. Fnctan eotiehdclal and imeraL
Specific gravity 2*67 to 2*76. Hardnees 7*5 to 8*0. ^e most uoal ooloiff of the
beiyl is green, of yarious shades between jeUow- and blae-green, arisiiig from tU
presence of iron in Tarious stages of oxidation ; yellow, blue, lose-coloaied, and oo-
lourless beryls are also found. The brilliant green of the emerald is dQ(> to the
presence of oxide of chromionL Lustre yitreons. The best specunejis of aoiaatd
and aquamarine are perfectly transparent; but the transparency is eenendly greitljr
diminished by cracks and stris, the coarser Tarieties being opaque m the mass and
translucent only at the edges. Beiyl is difficult to fuse by itseLf before the blowpipe,
melting to a glass at the edges only ; with borax it fuses readily to a transpinot
glass ; with phosphorus-salt^ it leaves a skeleton of silica.

Beryl from Limoges was found by 0. Gmelin to contain 67*54 SiO', 17*63 AlH)*, and
13*51 Gl'O (s 98*68); a specimen from Fahlun, ansdysed by Beizdiua, gare 68*36
SiO«, 17-60 A1«0«, 13*13 G1«0, 0*72 ¥e*G» and 072 TaO* These and numerous otha
analyses agree nearly with the formula above given (calc 67*46 SiO", 18*74 AlH)",
13*80 GIO), which, by substituting al « §A1, may be reduced to that of a metaolicste
{Glal) SiO*.

Beryls are found in various parts of the world; the finest emeralds eooie from
Peru, where they are found traversing day-slate, hornblende slate, and granite; tine
specimens are also obtained firom Katharinenburg in Siberia ; inferior varieties from
the Heubach valley in the district of Pinzgau in Sakburg; varieties are also fjoond
iu some old mines in Mount Zabarah in X^per ^^pt^ finm whidi spot the andeati
are supposed to have derived their emeralds. Fme transparent beiyls or aqai-
marines are found in Brazil, in the granite district of Nertschinsk in Siberia, in the
Ural and Altai mountains, and in the granite of the Mome mountains in thaoonatj of
Down, Ireland. Opaque beryls, sometimes of very laige size, are found at LangenlBln
in Silesia; at Bodenmais in Bavaria, near Limo^ in France; at Einlodi, Bnnaodi,
and Cairngorm, Aberdeenshire ; and in the counties of Dublin and WicUow. Between
the Connecticut and Marimac rivers, near Crofton in North America, enotmoos
specimens have been found, measuring from 4 to 6 feet in length, and veig^iiBg between
2000 and 3000 pounds.

Syn. with Glttcxnuic.

Selenide of Copper.
JBerzelite, Kuhnite^ Chaux arseniatS aniydr% Magnaum Pktr-
macolite, As^(Mg*Ca')0*. — A massive mineral occurring near Langbanshytta in
Sweden. It has an imeven fracture, and exhibits traces of deavability in one diIe^
tion. Yellowish-white to honey-yellow, with waa^ lustre; translucent on the edges.
Perfectly soluble in nitric acid. Before the blowpipe, it exhibits the usual reacticDS
of arsenic, and with soda shows evidence of a trace of manganese. (Euhn, Aon. C3l
Pharm. xxxiv. 271.)

smZBlbXW. A mineral found in the older volcanic ejectionB near Lake Albaoo
in Italy, together with hauyne, augite, and mica. It crystallises in octahedrons or
dodecahedrons, belonging to the regular system, sometimes forming tvin-crjstals;
cleavage tolerably distinct, parallel to the faces of a cube. The ciystala are ofta
uneven and rounded. It occurs also in spherical and stalactitic fbnna^ masmve sad
imbedded. Fracture varying from conchoidal to uneven ; colour white or grey ; In^
vitreous to dull; varies from transparent to perfectly opaque; streak white; har^
ness 5*0 ; specific gravity 2*428 to 2*727. According to an imperfect aoaljais hj
lu Gmelin, its composition is similar to that of leucite. When pulverised and ignited,
it yields a small quantity of water. Melts with difficulty before the blovpipe to s
tumefied glass ; with borax readily to a dear glass. Dissolves slowly in m^ sod,
yielding a jelly of silica when heated. Similar crystals have been found in nepheufi-
dolerite frvm Meiches in Oberhessen. (Handw. a. Chem. iL [1] 102S.)

The same name has been applied to native selenide of copper.

BSSUBlbXra. This name has been given to Mendipite, Petalite^ Thorite, and
Berzeliite.

BBTA« Beet. — ^A ^enus of plants, belonging to the natural order Chenopodiseeft,
distinguished by the large quantity of sugar contained in their roots. The thice
principal spedes are: — 1. Seta milgaris, common beet, well known for its sweet criffls»
roots, which are used as a salad. — 2. Beta oi/ela, chard beet, inferior in the siae snd
flavour of its roots, but distinguished by its remarkably thick-ribbed leaves, which a»
used in France in soups ; or the ribs only are cut out and stewed like s**"^"^"!
3. Beta altissima^ fidd-beet or mangold-wurzel, sometimes, though erroneoualy, i^garoed
as a hybri4 between the two former. This is by far the most important speaes, as it
is extensively cultivated for feeding cattle, and in France and Qermany also fcr the
extraction of sugar.

BETULIN— BEZETTA,

583

• The zoot of iiMtn«>M«wm«eI oontains crystallisable sii^, identical in ereiy respect
vith cameHBiigar. Payen giTea for the ayerage composition of tibe root^ 83*5 per cent
water, 10*5 sugar, 0*8 cellular substance and pectose, 1*5 nitrogenooB matter (albumin,
&e.), and 3*7 pectin and salts. The salts consist of nitrates and ammonium-salts, toge-
ther with alkaline and earthy phosphates, sulphates, chlorides, oxalates and malates, or,
according to some chemists, citrates. The root has also been stated to contain two or
three peculiar acida, which have not been thoroughly examined. The dried leaves
contain, according to Sprengel, 15*44 per cent. ash. The seed contains 11*6 per cent
water, and in 100 pta. of diy substance, 0*09 sulphur and 6*58 ash. (Way and
Ogston.)
The foUowing table exhibits the composition of the ash of the seed, leayes, and roots: —

Potash (anhydrous) •
Soda „

lime ....
Magnesia

Alnmina and feme oxide
Manganic oxide • • '
SiUea ....
Sulphuric add (anhydrous)
Phosphoric „ „

Chlorine • • •
Carbonic acid (anhydrous)
Chloride of sodium

Afh of Med.

Way.

161

6-8

13-4

15*2

0*4

1*8

3*6
13*1

18-8
15*3

Attaofleatef.

Ogston,

36*3

21*3

14*9

5*4

0*4

2*7

6-3

4*5

6*9

Aih of rooU.

I^rengel.

23*9

531

4*8

2*2

2*3

1-8
21
2*8
6*3

Ettl.

19*5—26*6

22-4— 30*6

3-2— 4-5

7*0— 9-8

01— 01

141—19*8
2-5— 2-5
2*4— 2*4
1*4— 1*9

C*H^*0*. — A resinous substance extracted fiom the outer bark of
the birch-tree (BeHda alba\ or from the tar prepared therefrom. It was discoTered
by I«owits (CrelL Chem. Ajin. 1788, i 802), ana analysed by Hess (J. pr. Chem. xiri.
161). It belong to the series of resins, including ^Ivic add, which are produced by
oxidifttion from hvdrocarbons of the form C^H"". To extract it, the dried bark is ex-
hausted with boiung water, then dried again and treated with boiling alcohol. The
sohition on cooling deposits the betulin, which is pressed, dried, and recrystallised
from ether. It forms small crystalline nodules, which melt at about 200^ C. The
melted matter is colourless and transparent and gives off vapours which smell like the
bark when heated. It may be distilled in a current of air. It is not dissolved by alkalis.

JLVru JaOXBTZO AOZS. According to Kossmann (J. Pharm. [31 xxiv. 197)
birch-reain consists of an add, C*'H**0', which is oonyerted by nitric add into picric
* * but is not decomposed by sulphuric add.

See Nbpbblik.

A ferruginous mineral occurring at Horhausen andMontabaur
in Nassau, and near Cork in Ireland. It crystallises in rhombohedrons deavable
parallel to the base, and having the rhombohedral faces horizontally striated. Colour
black to olive-green. Streak light fpceen. The fresh crystals have a waxy lustre.
TfyjainoM above 4*0. The Nassau mineral has a spKodfic gravity of 4*0018, and mdts
readily before the blowpipe (S an d b er g er). The Irish variety has a specific gravity of
4*296, and is infusible (Bammelsberg). It contains sulphate of lead, assodated witii
fearne sulphate, arsenate, and phosphate, the two latter replacing each other isomor-
phoualy; it also contains water (Pavy, Phil. Mag. [3] xxxvii 161). According to
Bammelsberg. it is 2(Pb»0.S0») + Fe«0*.SO« + 3FeW.P«0» + 9H«0; according to
Ssndbereer, Pb«O.SO» + 3Pl«)(As'0*; I«0») + 3[3Fe*0«(As'0«; I«0*)] + 24H*0.
(Handw. £, Chem. ii. 1029.)

WMEMTTAm Thumuol en drapeaux, SchminklSppehen. JSesetta rubra et
emntUa, — A dye or pigment prepared by dipping linen rags in solutions of certain co-
louring matters. Bed bezetta is coloured with cochineal, and is used as a cosmetic.

Bine bezetta (Toumesol en drapeaux), which is chiefly used for colouring the rind
Off Dutch cheeses, is prepared at GaUaigues near Ntmes in the department of Gard,
from a euphorbiaceous plant Chrozvphora iinctoria or Cretan tinctoria. The fruits
and the tops of the plants are gathered, and the juice being expressed, rags of coarse
doth are mpped into it then dried, and afterwards exposed to the fumes of mules' or
horses^ dung. This last operation is called aluminadou. The doths are turned from
to time^ to ensure uniform coloration and prevent any part from being exposed

pp 4

584 BEZOAS— BILE.

too long to the Aimes of the dung, which would turn them ydlow. Thej are then
dried a eeoond time, again soaked in the jnice, mixed thia time with mine, and lisUy
exposed for some time to the action of the son and wind. The quantity thna maini&o-
tnred amounts to about 60 tons yearly. The blue of beaetta is reddened by adds, like
litmus, though not so quickly, but differs from, the latter in not being restored hj al-
kalis. According to Joly, the same dye may be obtained from other enphorbiseeoQB
plants, Chroeop&ra oblongata, Cplicata^ Oroton tricutpidatum, Mereuriaiu perenmi^
and M. iormentosa. The juice exists in all these plants in the colourless state, and
turns blue only on exposure to the air. (Handw. d. Chem. iL [1] 1030; OerL
Traiti, iii. 820.)

BBBOAB* This name, which is deriyed from a Persian word implying an anti-
dote to poison, was giyen to a concretion found in the stomach or intestmes of an
animal of the goat kmd, Capra t^agta^ which was once veiy highly Talued for tliis
imaginary quauty, and has thence been extended to all concretions found in snimaK

Acconiin^ to Taylor (FhiL Mag. Na 186 p. 36 and No. 186 p. 192), besoais may
be diyided mto nine yarieties : — 1. Phosphate of calcium, which forms concretiona in
the intestines of many mammalia, — 2. Phosphate of magnesium : semitransparent and
yellowish, and of specific grayity 2*160. — 3. Phosphate of ammonium andmagneainm:
a concretion of a |;rey or brown colour, composed of radiations fiom a centre.—
4. Oxalate of calcium. — 6. Vegetable fibres. — 6. Animal hair. — 7. Ambergris.—
8. Lithofellic add. — 9. Ellagic or bezoardic acid.

Of true bezoars there are three kinds, oriental, occidental, and German. The
true oriental bezoars found in the Capra mgragvM, the gazelle {AwtUope JDorcas),
and other ruminant animals, are spherical or oyal masses, yaiyins from the size of s
pea to that of the fist, and composed of concentric layers of resmous matter with a
nucleus of some foreign substance, such as pieces of bark or other hard yegetaUe
matter which the animal has swallowed. They haye a shining resinous fracture, aze
destitute of taste and odour, nearly insoluble in water and aqueous hydrochloric acid,
but soluble for the greater part in potash-ley. When heated, tiiey emit an agreeaHe
odour and bum away, leaving but a small quantity of ash. These characters spffice to
distinguish the oriental bezoars from those yarieties which contain a considerable
quantity of inorganic matter. There are two kinds of them, the one consisting of ellagic,
the other of lithofellic acid. The latter haye a more waxy lustre and greener oolonr
than the former, and are also distinguished by their smaller speciflc grayity, yiz. I'h
while that of the ellagic acid stones is 1*6. The^ contain, besides lithofellic acid, a
substance resembling the colouring matter of bile, and are perhaps biliary calcnh.
Oriental bezoars are greatly prized m Persia and other countries of the East for their
supposed medicinal properties. The Shah of Persia sent one in 1808 as a present to
Napoleon.

The oocident4d bezoars are found in the lama {Auchenia Lama), and in A^ Vuh^m-
they resemble the oriental in external appearance, but difif^ tot^y in their cheniical
characters, inasmuch as they consist chiefiy of phosphate of calcium, with but little
organic matter.

German bezoars, which are chiefly obtained from the chamois or gemsbodc (AntU^
rupicapra), consist chiefly of interlaced yegetable fibres or animal hairs bound together
by a leathery coating.

BBZOAXBXO ACXB. Syn. of Ellaoxc Acm.

BXKOASSZCVM AVZXAZJL An antiquated medicament madefrom the dned
hearts and liyers of yipers, and supposed to be an antidote against poison : hence its
name.

BBZOAXBZCUM IWIIIIIBATtm A name applied by the older chemi^ to
antimonic acid, especially to that prepared from butter of antimony by the action of
nitric acid.

BX-COICVOinroB. See Di-CoicFouia>s and Kohxnclatdbb.

B1ZA8TBZW. Syn. with Agalmatoiitb.

BJQLB. Gall, Galle. (Lehmann, "Physiological Chemistry," Oayendish Society's
Edition, ii 61; also Gmelin's Handbuch, yiiL 38. Strecker, Ann. CSl Phann.
Ixv. 1 ; Ixyii. 1 ; Ixx. 149. Gundelach and Strecker, ihid. Ixii. 206).— Bile, •«
secreted by the cells of the liyer, is taken up by the biliary ducts, which unite to fona the
hepatic duct^ by which the secretion is either discharged directly into the d-aodeaam, GC
is conyeyed through the c^ic duct into the gall-bladder, wherein it becomes aoeiunu-
lated and to some extent inspissated. Cystic bile when taken from a healthy animal
recently killed, is a mucous, transparent, ropy liquid, of green or brown coio^'
It has a bitter but not astringent taste, sometimes leaying a sweetish after-taste, aud s
peculiar odour, which, when the bile is warmed, is often yeiy much like that of i&i^

BILE. 585

Its flpeeifle ^lity is ftbont 1*02. It does not difiVue itself readily thiougli water,
QnleBi the mixture be etiired. Its reaction is, for the most part» fsdntly aU:aline, some-
times nentnl, never aeid, excepting in pecnliar states of disease. Bile in its ordinary
•tate^ before the mnens is remoTed, pntiefieB rery readily ; bat when freed from mncus,
it is much less prone to pntrefiBtedTe decomposition.

The chemical composition of bile yaries to a certain extent according to the nature
of the animal which yields it ; but evezy kind of bile contains two essential constitaents,
TIL a resinoQS and a colonring matter, associated with small quantities of cholesterin,
htA, salts of fatty acids, and certain mineral salts, chiefly chloride of sodium and
phosphates, with smaller quantities of phosphate and carbonate of sodium, phosphate
of caldnm, phosphate of magnesium, and extremely minute quantities of iron and
mangsDese, but no alkaline sulphates. No salts of ammonia are found in £resh healthy
hOe^ but during the putrefiguition of bile, ammonia is produced. Bile also contains
mncos mixed with oelis of epithelium.

Tbfr retincns matter of biU is the most abxmdant and important of its const!-
toentB. It consists, in nearly all cases, of the sodium or potassium salts of two nitro-
gf nised acids, one containing sulphur, the other free from that element. The former
of these acids, called tauroeholic acid, is resolred by the action of alkalis into
taurine and cMia acid^ a crystalline add containing neither nitrogen nor sulphur, and
changing, under certain circumstances, into an amorphous isomeno add called cho-
loidic acidy differing from it only by the elements of water :

0»^*»NSO» + H«0 - C»*H«0» + 0«H7NS0»;
Tanroeholic Chollc Taurine,

add. acid.

and the latter, called glyeocholie acid, is resolved in like manner into cholic add
taid glyeoeme :

(?^«N0« + H«0 = C"H«0» + C*H«NO»
Gljcoch<^ Chollc Oljcodoe.

add. add.

AH kinds of bile, excenting that of the pig, contain one or both of these adds. Pi|fs
bile contains an add called glyco-hyocholic acid, analogous to glyeocholie acid,
and, like that compound, resolvable by the action of alkalis into glycodne and hyochoHc
add, an add not containing nitrogen :

CrB«NO* + HK) » C»H*^* + C*H*NO».
Glycohjo- HjrochoUc Glycodne.

cholic add. add.

The colouring fnaiter of bile, hile-pigmeTUy or ehotochrtyme^ is also a nitrogenised
add, and is decomposed by nitrons acid, with evolution of nitrogen and formation of a
aystaUised add, cholochromio acid, which is free from nitn^en. (Thudichum,
Chem- Soc Qu. J. xiv. 114.)

The bUe of carnivorous and omnivorous animals, including man, contains a brown
pigment, the cholepyrrhin of Berzelius : that of birds, fishes, and amphibia has usually
an intense green pi^ent, bUiverdin, The brown pigment is always combined either
with soda or with luue ; in the latter case, it is insoluble, and appears in the form of
brown granules when the bile is examined by the microscope.

The analysis of bile is conducted as follows :

The bfle is first mixed with half its volume or more of 83 per cent alcohol, which
throws down mucus and epithelium; the predpitate is rinsed with spirit, then
with water, afterwards dried and weighed.

The bile thus freed from mucus, is evaporated to dryness, first over the water-bath
and then under the air-pump on a sand-bath heated to 100° 0. ; the residue is left to
cool in vacuo, after which, air dried by passing over chloride of caldum is introduced
into the recdver, and the weighing is completed as quickly as possible, because the
dried bile is extremely hygroscopic.

The residue is next digested for a condderable time with ether, which takes up fat
and cholesterin. The total quantity of these matters may then be determined by
erapnating the ethereal extract ; but the different substAUces contained in it cannot be
separately estimated, unless verv large quantities of bile are operated upon ; in that
eaee, the fiitt^ adds (stearic and maigario or palmitic adds) may be separated from
the cholestenn by predpitation as leafsalts.

The residue insoluble in ether, which contains the essential constituents of the bile,
IS next to be treated with cold abeoltUe alcohol, which dissolves the salts of the biliaiy
adds, together with part of the bile-pigment ; the greater part of the alcohol is then re-
morred by evaporation ; ether added to the concentrated solution as lone as any tur-
bidity is produced ; and the liquid left to stand for some time in a cool ^ace.

Hie alkaline taurooholate and glycocholate are thereby predpitated, and

586 BILE.

tbeir qnantily niAy be estimated hj vBahing tbe pfeeipitate witli efto; tnd vodbing
it after drying OTer the water-bath. It alwaya, bowever, eoDtains a ootain patbonof
bile-pigment| whidi eaimot be oompletelj separated anlea it eoniista of pun dnk-
pyrrhio^ in which case it may be separated by dthnide of ealdion. The qwntity of
soda or potash awHoriated with the biliaij acids and the Inle-pigmient, nay be
determined by deeompoaing a weig^ied poitioa d the ether^pfee^tate with tulplmne
add.

The tamocholie and g^yooebolie adds cannot be completely sepsiated one from the
other. An approximate sepantion may be effeeted by dinohing the pneipttte in
alcohol, and treating it with neatnl acetate of lead, wfaidi precipitates only the gly»>
cholic add; bat the best way of estimatii^ the lelatiTe quantities of the two adds, k
to determine the amonnt of «iiiJpAiir in the ethet^pcedpitate, by foang it with mtre or
by one of the other methods gnren under Amaj^tos (OaoAsnc), pi 226. Sray 6ptB^o(
sulphur correspond to 100 pU. ot tsurocholate of soahmL

The remdneof the bile, inmlable in abeolote alcohol, must nowbedetennined with the
Tiew of dieddng the analysis. It contains pigment^ p^lly free and piitly oombiBcd
with lime; aim aH'sline and earthy pho^iates^ with chloride and esriwnite of
Bodium, Tery raidy sulphate of potaadum, but often a little taurine; its amoimt ii
generally too small to ulow of the quantitatiTe sepantion of theee substaoeeB, nnkai
Teiy large quantities of bile are operated upon. Altogether the detenninitioiis which
hare bmi made of the amount of pigment^ cholestedn, ikts, httj adds, and minenl
oonstitaents of bile, cannot be legaided as more than unoaaniatioDs to the truth.

Ptttenkofer's Test for Bile — ^When bile is mixed with a strong eyru^ of segir, lad
then with strong snlphuric add, so that it becomes heated, it assumes a deep Tidet-nd
or purple tint, which disapfpeon on addition of water. This reaction is prodoeed hy
rholic, dioloidic, glycocholie^ and tanrocholic adds (or the corresponding aeidB in ra^B
bile), but not by any other substance; it is, therefore, perfectly charartmatie of oue,
and affords a veiy delicate indication of its presence. The beet mode of ^yixig it
for the detection of small quantities of bile in blood or other animal fluids, is u
follows : — ^The alcoholic extract of the liquid to be tested for bfliazy mattei; is diinlTed
in a little water, and mixed with a sin^ drop of a solution of sugar (1 pt^ of sogsr to
4 pta. of water), and pure strong sulphuric add is then added by small quantitiei, till
the turbidity at first produced, disappears, cooling after each addition ; it then for t
few moments exhibits a yellowish colour, which, however, soon changes to apale cheny-
red, then to deep carmine, then to purple, and finally to an intense Tiolet tint For
the success of the experiment, care must be taken not to add too much sugar; othff-
wise a black mass wiU be fonned, which will completely maak the reactioo. Tho
temperature of the mixture must be allowed to rise to about 60^ C. but not higher.
Tbe reaction takes place with any kind of sugar, and likewise with acetic add.

(imposition of tke Bile of various animals, — Human bile consists mainly of tsmo-
chlorate of sodium, with very little glycocholate (Gorup-Besanei). Ox-(t7<,0D
the contrary, contains chiefly glycocholate (Strecker). Pig^hilt, as aheady ob-
served, consists mainfy of the sodium-salt of an add analogous to glycocholic add; tv.
glycohyocholicacid (Gundelach and Strecker), t<^[ether withasmaQqiiasti^
of a sulphuretted add, yielding taurine by decomposition : taiiiro-hfoooMio eeii; it
likewise contains a very strong base containing sulphur.

The bile of most other aniinalB consists mainly of taurocfaolate of sodium or potas-
num. That of the doff contains only taurocholate of sodium ; that of the thup, and
that of the kangaroo contain taurocholate, with yeiy little ^ycodiolate. In the bile
of several kinds of fish, viz. turbot, eod, piJce, and perckf Stredcer found tanrodoUte,
with mere traces of glycocholate ; a similar result was obtained by Schlossberger
(Ann. Ch. Fharm. cviiL 166) with the bile of the shad-fish. Aoonding to (Benseh
(Ann. Ch. Pharm. Ixv.) and Strecker, the bile of sea-fish contains potB8Biiim<4iltS|
that offresh^waier fish chiefly sodium-salts. The bile of the Boa Anaconda rSchlie*
per, Ann. Ch. Pharm. Ix. 109) and that of the Ppthon ti^ (Binder, Hid, aL 91)
consist mainly of taurocholate. Goose-bile appears likewise to consist easentiany of
taurocholate of sodium, though Harrson (Arch. Pharm. [2] IviiL 138), and noie
recently Heints and Wisliscenus (Pogg. Ann. cvitL 647) state that the adphnrpttel
add of goose-bile differs in compodtion from taurodiobc add; Heints and 'Wli-
liscenus assign to it the composition C"H*VSO*; but the analyses are not gaite
satisfactory.

Taurocholate of sodium contains about 6 per cent of sulphur : now in the dzied
bile of the dog, Benseh found 6*2 per cent, sulphur ; in tiiat of the fox, 5-96 per ceal;
of the wolf 5-03 ; of the bear 5*75 ; of the pig 032 ; of the calf 5*62 ; of the aheep6*46; of
the goat 6*99 ; of the domestic fowl 5*57 ; and of several fishes 6*46 per cent

In normal human bile, Frerichs found 14 per cent or rather more of solid ^'"^
iuents ; Gornp-Besanec, in the bile of two recently executed criminal/^ foaa^ 1^^'

BILE. 587

tnd 17*78 p6r OMit Bofid matter; in that of an old niaiii 9'18 per eent; and in that of
a boy of twi^a yean old, 17*19 per cent solid matter. Ox-bile contains 10-18 per
eent aolid constitoenta; pig^s bile 10*6 to 11*08 per cent (Gnndelacb and Strecker) ;
do(f a bfle 6*1 per cent ; cat's bile 6*6 per cent ^Bidder and Schmidt) ; sheep's bile
6*8; rabbif 8 bile 1*8 ; goose bile 6*9 ; kangsroo's bile 14*18 ; and crow's bile 7*3 ; per cent.
solid constitiiflntB. '&e concentration of the bile appean to incresae with the time it
zemaina in the gall-bladder.

TbA prraortion of a$k in the dried residne amoonts in normal human bile to 6*14
per cent dornp-BeaanezX in ox-bile to 12*7 (Berzelins); in calTsbileto 13*16
(Bens eh) ; in sheep's bile to 11*86; in goat's bile to 13*21 ; in pig^s bile to 18*6; in
fox bOe to 12*71 ; in that of the domestic fowl to 10*99 ; in that of fresh-water fish,
to 14*11 per cent ; in that of the firesh-water tortle {Emys geographical to b'6 ; and in
that of the salt-water tnrtle {Emytinteulpta) to 6*3 per cent (Wetherill, J. pr. Chem.
IxxtL 61). The fresh bile of lifthon iwria yields 1*21 per cent of aah.

Ox-bile extracted £rom the gftll-blaader without pressore, contains 0*184 per cent
muctu; hnman-bile 0*158 per cent (Lehman n); Gomp-Besanes found in human bile
1*46 and 2*21 per cent mucus and btie-pigment. The bile of the kangaroo contains
4*34 per eent fiwcuB and colouring matter, and 1*09 cholesterin and fat; that of the
shad-flah contains 1*28 per cent mucus and cohurtng-matter, and 0*23 per eeatfat;
that of I^kon iigris, contains 0*89 per eent mucus and 0*03 fat ; goose-bile contains
2*66 per cent mucus, 0*36 /o^ and ekolesterin, (Marrson.)

The btOe, like all the other normal secretions, is liable to alteration from disease, and
sometimes contains heterogeneous constituents. Mbumiin is sometimes found in it,
especially in &tly lifer, in Bright^s disease, and in the embryonic state. Urea has
been fonnd in the bile^ in cases of frtty degeneration of the kidneys, and in animals
whose kidneys have been extirpated ; also in cholera. Bizio once discovered a dark-
red non>bitter bile in a patient suffering from jaundice; it contained an emerald-
green pigment, to which he gave the name of erytkrogen, from its volatilising at 40^ C.
and giving off a red vwour. A similar substance was found by Lehmann in a case of
acute yellow atrophy of the liver. In the bile of a child who died suddenlpr, Lehmann
found a considerable quantity of sulphide of ammofmim, but the previous history of the
ease was not known.

The normal constituents of the bile also vary in proportion, in various cases of
disease. The bile has been found to be poor in solid constituents, in persons who have
died from severe inflammatory affections, especially from pneumonia, and likewise in
fatal cases of dropsy ; it also contains an excess of water in diabetes, and in certain
cases of typhus ; in other cases of that disease, however, the bile becomes thicker than
in health. The solid constituents of the bile are commonly increased in those abdo-
minal diseases in which the motion of the blood in the larger veins is impeded, and in
certain cases of heart-disettse, in which the blood accumulates in excessive quan-
tity in the hepatio veins. In cholera, the bile is also found to be dense, tough,
and consistent The proportion of mucus is often increased when the bile is vexy
dilnte; indeed in typhus, the ^all-bladder sometimes contains scarcelv anything
else, the resinous constituents being almost, if not altogether absent ; the same is
obserwd in catarrh of the biliarv duets. (Lehmann.)

The separation of crystals of cholesterin, which is sometimes, though rarely, observed
in mcnMa bile, appean to be associated with an increase in the relative quantity of
that aabfltance ; tnis phenomenon has been observed by Gbrup-Besanez in very con-
centrated bile. Free fat is always present in the bile, but in the normal state is held
in sofaition by the taurocholato of sodium ; fat globules have, however, been observed
by Gorap-Besanei in the bile of persons who have died from typhus, and from tuber-
coloais in the colliquative stage. (Lehmann.)

The bile is very seldom aM; an add reaction has been observed in typhus, but it
may have arisen partly from spontaneous decomposition after death, partiy from
effbaion of pus into the gall-bladder : for pus, when contained in an enctoeed space,
often becomes add with great rapidit;^. (Le h m a n n.)

Putrefaction of Bile. — ^When bile is left to itself^ dther in a closed or in an open
TCBBcl, it tmdergoes gradual decomposition, ao^uirins an offensive odour and add re-
action, and yidding a solid depodt containing <£olic add and other substances.
Thndiehum (Chem. Soe. Qu. J. xiv. 118) found that ox-bile left for a year or
two in large bottles, well stoppered, and completely filled with it, had assumed a
di^t add reaction, a bright port wine colour, and had depodted a copious, flalnr,
ereen and brown depodt, mixea with white chalk-like particles and ereenish cxystaJs.
This depodt was found to consist of cholochrome (bue-pigment) (molic add, phos-
phate of caldum and magnesium in dichroic cxystals, and mucus. The fluid part of the
ofle was found to contain prindpally choloidate of sodium with a little chelate ; also
tanxine, valerate and acetate of sodium, and of ammonium, and phosphate of sodium,

588 BIMSTEIN— BIRCa

but no glTOoeine, gflyeocholic add, or tanrocholio acid. The deeompodtioii appean *
to begin by the reeolation of the gljoocholate of sodium into eholate of sodium and
glycocine, and of the taurocholate into eholate and tauzine. The ammonia and aoetio
acid are probably formed by the decomposition of the glyoocine (ozyacetamic add) ;
the origin of the Taleiric add is obscure ; these adds unite with a portion of the soda
and predpitate some of the eholochrome and cholic add, the rest of that add remain-
ing in solution as choloidate of sodium. From the experiments of Gorup-Beaanes
(Ann. Ch. Pharm. lix. 129) it appears that bile allowed to decompose m an open
yessel, at a comparatiyely high temperature, 25^ to 30^ "SL, deposited chiefly choloidie
add, but when the deoompodtion took place in a cellar at 10® to 12® R, cholio
acid was depodted iostead of choloidie, the higher temperature fEiTOuring the trans-
formation of cholic add into its amorphous modification.

Human bile putrefies much in the same manner as ox-bile ; but the actual products
are usually modified by the decomposition of the albumin which is present in nearly all
the bile that can be obtained for examination, yiz. the bile of persons who have died
of disease, and usually not obtained tUl some days after death. The alkaline products
resulting from the decompodtion of the albumin partially neutralise the add products
of the decomposition of the bile, and thereby prevent^ to a certain extent^ the formation
of insoluble compounds. (Thudi c hum.)

Biliary ceUetdif or Gall^tonea. — ^These concretions in man sometimes consist diiefly
of chlolochrome, held together b]r some binding material, generally supposed to be
mucus, or inspissated bile, but consisting, acoordins to Thudichum (loe, cit.)j of cholic
or choloidie add, or both. In most cases, a small nudeus of this character is formed,
and becomes coated with eholesterin, which then forms the chief mass of the concretion.
Earthy phosphates and carbonates are likewise present. Ox gall-stones consist mainly
of cholodirome, cholic add, and choloidie add, with small portions of eholesterin, and
unaltered bile mechanicaUy endosed : they also contain the phosphates and carbonates
of caldum and magnedum, and an ammonia-compound, posdbly sulphide of ammo-
nium (Thudichum). The formation of these calculi is attributed by Thudichum to a
decomposition of the bile, similar to the putrefaction which takes place when it is re-
moved from the gall-bladder. (See Oai^-Stoubs.)

BimTBZV. See Puxicb-Stoms.

TBBOBT OV SAIiTS. The theory which regards salts as com-
pounds of a metal with an add or chlorous radide : e. g. acetate of potassium »
C'H*0*.K : nitrate of potasdum, N0*.£, &c (See Acids.)

BZnXTB. A natiye snlphaisenite of lead, ftom the Binnenthal in the Yalais,
where it is found imbedded in white granular dolomite. It sometimes forms distinct

Srismatic crystals, belonging to the rhombic system, but more frequently, broad, reed-
ke, crystalline aggregations, or crude masses : it is yery brittle and friable. Colour,
steel-grey to iron-black, or light lead-grey, with strong metallic lustre. Opaque. Streak
reddish-brown. Hardness, 2*6 to 3*0. Specific gravity 6*0 to 5*5. Its composition
appears to be liable to some variation. Ajocording to Waltershausen, it is a mixtore in
variable proportions of artenomelanet Pb^.As'S*, and scUrodase, 2Pb*S jLb^. (Handw.
d. Chem. iL [1] 1099.)

Syn. with An OBTHm.

Uniaxial or Magnesia Mica. See MiOA.

{Betvla alba.) — ^The hark of this tree contains, according to John (Re-
pert Pharm. xxxiiL 327), one-third of its weight of resin, and a considerable quantity
of tannin, whence it is used for tanning leather, and for black-dyeing, espedally of silk.
The white, easily separated epidermis of birch-bark, contains resin, tannic acid, ex-
tractive matter, and ash, consisting chiefiv of sesquiozide of iron, silica, and lime.
The red-brown bark on the lower pi^ of the stem of an old tree, yidds by suocesdve
treatment with ether, alcohol, and aqueous potash, a resin, C*H*0*, soluble in ether,
a red-brown colouring matter, CH*0', soluble in alcohol, and another red-brown sub-
stance, CH"0*, soluble in alkalis, and predpitated by aads. (Stahelin and Hoch-
Btetter, Ann. Ch. Pharm. li. 79.)

The leawa of the birch contain, according to Grossmann, 0*3per cent, essential ofl
and wax, besides tannin, and a bitter yellow colouring matter. Tney are used as fbdder
in northern countries.

The diy wood of the birch contains, accordinff to Karsten, 0*25 to 0*3 per cent ash ;
according to Berthier 1*0 per cent Berthier round also in 100 pts. of the ash, 16 pts.
of soluble and 84 pts. of insoluble salts. Wittstein (Pharm. Centralb. 1851, p. 404),
has analysed the ash of birch-wood growing on different soils : viz. a. on the paU-
gonitic soil of Akarcyri in Iceland, composed of weathered volcanic rocks; b. on
the sterile calcareous soil of Morschen in Kurhessen, bdonging to the Muachelkalk

BIRCH— BIRDLtME. 589

fimDation ; & on the sandy soil of Marburg in Knrheaaen, belonging to the sandstone

KK)

. 12-8

14-8

S0« ,

0-02

Na«0

1-6

1-2

2-8

SiO» .

2-9

Ca*0

. 26-7

46-9

C0« .

18-8

24-6

12-9

MgK)

2-2

11-8

PW, .

4-2

16-6

A1H)«

1-4

0-4

HH) .

7-1

9-8

FeH)» .

0-8

0-4

Charcoal .

0-6

0-4

0-6

MnH)» .

trace

3-8

Sand

19-8

2*4

Bdms-fubgusl — ^The fdngus of the birch-tree contains woodj fibre, phobkphene (a
sabstance also contained in pine-bark^, fat, a bitter principle, nncrystallisabfe sogar,
tannin, malic add, tartaric acid, and atrio acid. It yields 16*3 per cent, water, and
1*2 per cent ash, eontaining in 100 pts. : 6*0 K*0 ; 41 NaK) ; 488 Ca<0 ; 6'6 Mg»0 ;
81 AlH)*; 1-6 Fe*0«; 44 S0»; 06 CI; 166 PK)*; 47 SiO«; 15*9 C0». (J. Wolf^
Yioteyahrschzift 1 prakt Pharm. iii 1.)

BncH-JuiCB. BscH-WATBB. — ^This liquid is obtained, like the jnioe of the maple,
Ij boring the stems of the trees in February and March. A tree of average size yields
abont 8 fitresof jnice, consisting chiefly of sngar, together with nitrogenous substances
and Tazious salts^ including acid tartrate of potassium. It easily ferments, and quickly
tmiis aonr when exposed to the air. In some localities, as in the Haiz, in Courland,
and in liTonia, it u used for the preparation of an effervescent wine.

BntcK-on.. — ^All parts of the birch-tree appear to contain an essential oil. The
ycmng leaves and buids yield, by distillation with water, a colourless oil, which gradually
turns yellow in the air, has the aromatic odour of newly developed birch-leaves, and a
taste mild and sweetish at firsts afterwards balsamic and burning. It is mobile at
14^C., becomes viscid at 0^, and solidifies to an amorphous mass at —10^. It dis-
aolres in alcohol more readily than in ether : water is said to extract a steaioptene (?)
from it. (Grossmann, B^pert Pharm. xxiii 327.)

The bark of the Betula Unta^ a North American tree, yields an essential oil identical
with oil of winter^reen (salicylate of methyl) : it does not however exist in the bark
ready formed, bnt is produced from a crystalline substance, gatdtheriny contained in the
bark, by the action of a ferment in presence of water, in the same way as bitter^almond
ofl fiom amygdalin. (Procter, Amer. J. Pharm. Jan. 1844.)

BiBCH-Rssnc . See Bbtulzn.

Bibcb-Tas. Dogged, Black Doggert or Beggeli, Birch-tar OU. — In Bussia and
other northern oounmes, the bark of the white birch is subjected to a kind of down-
ward distillation, in conical pits 20 or 25 feet deep, covered over first with a roofing
of stzaw, and then of turf and mould, having holes to regulate the admission of air, as in
the chaztxMd mailers. By this process, two products are obtained, namely, charcoal and
tar, the latter amounting to 60 or 70 per cent, of the bark. It is a brown-black viscid
Ikqnid, used for coating wood, and also for lubricating carriage wheels, as it remains
Hqaid even at very low temperatures.

This tar when distilled yields a brown strong-smelling add oil, and on rectifying
this oil, a liquid hydrocarbon, having the composition of oil of turpentine, passes over
at 100^ C, mixed with an oxygenated oil, the proportion of the latter gradually in-
ereasiug as tiie distillation advances. The oxygenated oil may be removed by potash-
lej, and the hydrocarbon, C**H'*, is left behind. Its smell is like that of oil of
turpentine, but more agreeable, recalling that of birch-bark. Specific gravity 0*87
at 20° C. Boils at 1560. Vapour-density 5*2 (calculation 2 vols. 4*8). At - 16<^ it
deposits a small quantity of stearoptene. Sparingly soluble in water, readily in alcohol
and ether. It absorbs oxygen rapidly from the air, giving off carbonic anhydride, and
being converted into a resinous mass. It is also oxidised by nitric acid, giving off
hydrocyanic acid, and yielding two acid resins. It absorbs 32 per cent chlorine, with-
out forming a crystalline compound. Betulin is perhaps formed from this hydrocarbon
Ijj oxidation. (So brer o, J. Pharm. [3] ii. 207.)

BIBIIUEMX. The best birdlime is made of the middle bark of the holly, boiled
seven or eight hours in water, till it is soft and tender ; then laid in heaps in pits in
the ground and covered with stones, the water being previously drained from it ; and
in this stete left for two or three weeks to ferment, till it is reduced to a kind of mnci-
]age. This being taken from the pit, is pounded in a mortar to a paste, washed in
river water, and kneaded, till it is free from extraneous matters. In this state it is
left fbor or five days in earthen vessels, to ferment and purify itself, when it is fit for use.

It may likewise be obtained from the mistletoe, the yibumum lantana^ young shoote
of elder, and other yc^table substances.

It is sometiDiMi adnltaraffd vitli tnrpratiiie, oil, vitiflgar, tnd otliB nuttot
Good birdlime is of a greenish colour, and ■oui' flHTonr; gloej, stnog;, ud toa-
eious. and in Hmell resemblii^g linseed oiL By expovnrfl to the UTi it botxnms drj lai
brittle, so that it may be powdered ; bnt its TiBcidit]^ is wstored br wrtfiit. It
reddens tincture of litman. Expomd to a gentle best, it liquefies Bli^tl;,' mSu is
bubbles, becomes gramous, emits a Bmell reiiembUng tbat of animal 034 grnn tarn,
but recaveis its properties on cooling, if not heated too much. 71111 a gnatit lictt, it
bums, giving out a orisk flanfe and mnch smok*. The reudus eontaiui nlfiiil* ud
chloride of potassiom, caiboMt* of ealdom, and alumina, with asmallptriiniotiiai.

BZBinmL Sumiol BL' Atomic wigf^ 208 (Scbneider); 210 (T)Daii>—
The metal bismnth has long been knovn, bnt was fbnnerly often eoifOmidBl vilh lii
and lead. It is principally fonad in the metallic state, tnt also oeenti is anliu-
tion with mlphor, oiygeo. and tellnrinm. In Cornwall and CoinbeiiiBd it ii fbmd
associated with ona of cobalt^ and in Sibeiia wit^ lead, in the fbm rf MtdlMn a
bimtut^itiid-'/re.

For the arts it is ptepated almost exclmiTel; from natiTe bismath, aid tlis pot
■ouice for it is Saiany, where it oecors in metallic Tdtls in gneiss and day-slate, hcod-
panring ores of silver, copper, lead, and tin.

The process of extraction is reiy aimple, the mineral being merely hnled is dna

vesaeLt, so as to melt the bismuth, and thereby aeparate it frton the gangv^ « Hcoa-

panying rock. The i^ision is performed in icon tubes, laid in an indined podlica, b

a fumace ijig. 100). The ore u introduced at Hho upper end, if, which is Ihea {logged.

The otJier end, i, is diwd villi

'V' •"*'■ anironplalehavingin^otnre.^

throneii which the TO/OtA dH^

mns mto earthen poti, s, balfll

W a few coals placed in the ipce,

K, below, so as to keep the mcUl

in the melted state. It it tin

ladled oat and nm into numUi,

(See Pre'i DictKmani 0/ Artt.

Manvfactiira, and Ifina, 1 301.)

As thus prepared, 111* meMl ii

I impure, contsuiing >ii];|bnT ind
usenie, copper, nickel, iron, ind
other metals. It mij be paitri
I br placing it in a onciUe "ilk
about ^ it« weigit of nitr^ ai
keeping it melted at a temperature not too much above its point of ftuion, themiitm
being continually stirred, lie nitre, at first liquid, soon solidiflea, forming villi tl«
impurities a slag, which collects on the surface t^ the metal. B; repMtiig tlii)
operation a second time, the metal is obtained par&

Small qnantitiea of bismuth eiisting in lead-, copper-, and silver-orea, often Iwoiit
concentrated in the secondary prodncts of melalinigic operations, e«peci«lly In the
process of separating silver fiom lead by copellation. The lead ojidiies fanter tbu
the bismuth, so that towards the end of the cnieration a blackish litharge is obtvned,
containing bismuth ; and by reducing this mixed oiids, and again dpeUing tbe R-
suiting aUoy of lead and bismnth, the lead is oxidised and metallic binnatli itnsiu
(Jahresber. d. Chem. 1669, 711.)

To obtain chemically pure bismuth, the metal is dissolved in oifaric acid ; and Is ll»
clear solution, a Inrge excess of water is added, which precipitates the bismolh •• lj>«
nitrate, the other sabstanees remaining in solution. The precipitate is well -nM.
dried, mixed with black flux, and redu^ at a gentle heat in a endbla, at Qm bottn
of which a regulus of pure metal is fonnd.

Proptrtitt. — Bismnth is a metal of a greyish-white colour, with a distinct rcsal"
tinge. When pure, it crystalliaes more readily Uiononyortier metal. Itmaybsobtsined
in beautifiil ra^atals by the following method. A few pounds are melted m a fmobk
and then poured into an earthen dish previously made hot: When the sirtue cf the
metal has become covered with a crust, it is pierced on two opposite points *illi » "^
of red hot-iron, and the liquid metal allowed \a rnn oui On afterwards eartfiillT
removing the crust, the sides of the interior are found lined with beantiAd OT''^
often in pyramidal cnbes like the orstals of chloride of eodinm. They posMS u iri-
descent lustre, arising train a veiy thin film of oxide which has been fomipd on thnr
snrfcee while still hot, and exhibits the colours of thin plates. Native bismnll nr*-
talHses in cubes, and combinations of the cube with the octahedron ; bIm in rfgnlir
tetrahedrons, with cleavage very distinct, parallel to the bees of the oetabedroo (Efp''

BISMUTH. 591

Krytiollographie), In Dana's daneraiogy (iii. 20), on the other hand, the eryBtalline
ibrm is sUtea to belong to the hexagonal Bystem. Bismuth appears therefore to be
dimorphous. Its spedflc graTity is 9*83, and it exhibits the wtignUii anomaly, that
vhen it has been exposed to great pressure, its density becomes less. Pure bxnnuih
viud^ has been exposed to a pressure of 200,000 pounds, was found to have the
specific grayity 0*566. It melts at 264^ C, and expands about ^ in solidifying^
Hence its specific grayity is ^ater in the liquid than in tiie solid state. At a high
temperature, it may be distilled, and then sublimes in laminae. It is yery brittle,
\iaB a laminated, crystalline fracture, and is easily reduced to powder. Of all metals
it exhibits in the highest degree the phenomena of diamagnetism.

Exposed to diT or moist air, it does not alter, but when exposed in contact with water
in an open yesso, it becomes coyered with a film of oxide of bismuth. Heated in the
air, it bums with a bluish flame, forming yellow fumes. It decomposes water at high
temperatures only. Concentrated hydrodilorio acid acts on it with difficulty; sul-
phoric acid attacks it only when hot and concentrated. Nitric add briskly attacks it
and effects complete solution.

Bismuth forms three classes of compounds in which it is (7f-, M-, and pent-atonUe^
Tespectiyely. The tri-atomie oompounds are the most stable and the most numerous,
e,g. BiCn*, BiP, Bi^O*. Seyeral di>atomic bismuth-compounds are also known,
Tis. BiBr*, BiCl', BU', BiH)^ and Bi%'. The only ^t-atomie bismuth-compounds
hitherto obtained are the pent-oxide Bi'O', together with the corresponding acid and
•alts. £. A.

Plumbo-cupreous sulphide of bismuth. SeeNssnus-

OTm Bismuth unites readily with other metals, forming
easily fiosible compounds.

A natiye arsenide of bumuth containing 3 per cent of the latter metal, occurs at
Palmbaum, near Marienbeig. It has a radiated texture like natiye sulphide of anti-
mony. Specific grayity 5*392. Hardness « 2 (Breithaupt). 14 pts. of bismuth
fnaed with 1 pt of arsenic yield an alloy which expands stron^y in solidifying.

Antimony unites in all propoi'tions with bismuth, forming brittle alloys ; that which
eontaina equal parts of the two metals expands considerably in solidifying.

The most remarkable alloy of bismuth is that known as ''fusible meta V' which
eonaista of 1 pt. of lead^ 1 of Hn^ and 2 of bismuth. It melts at 93*75 0. Accord-
ing to Brman, it dilates in an anomalous manner when heated. It expands regu-
lariy from 32^ to 95^ C, and then contracts gradually to 131^ ; at which point it
occupies a less bulk than it did at 32^; it then expands till it reaches 174^, and from
that point its expansion is uniform. On account of this property of expanding as it
cools, while still in the soft state, it is much used for taking impression from dies, as
eiren the fidntest lines are reproduced with minute accuracy. An alloy of bismuth
with potassium is obtained when bismuth is fused with cream of tartar, 5 pts. bismuth
to 4 pts. tartar. (For the other alloys of bismuth see the seyeral metals.) R A

Snanm, BKOMXBBB or. The tH-bromide, Bi^Br*, is formed by heating
bismuth with excess of bromine. It is a steel-grey substance, like fdsed iodine ; melts
at 200^ C, and boils at a dull red heat, with formation of hyacinth-red yapours.
Heated with metallic bismuth, it yields a brown crystaUine mass, probably a di-bro»
vnde BiBi*, but it has not been obtained pure. (Weber.) B. A.

aiBMUTH, oaXMBXamm OV. Trichloride, B^'Cl*.— Bismuth and chlorine
readily combine, with eyolution of heat and light if the metal be finely divided. On
heating biamuth in a tubulated retort, in a current of chlorine, trichlonde of bismuth
distils as a white easily fhsible substance. It readify attracts moisture from the air,
becoming oonyerted into a crystallised hydrate. The same substance is produced
when binnuth is dissolved in aqua-regia, and the excess of acid eyaporated. Chloride
of bismnith dissolves in water containing hydrochloric add ; by pure water it is de-
composed into hydrochloric acid, which dissolves a portion of uie chloride, and a pre-
cipitate consisting of oxychloride of bismuth :

BiCT + H«0 - BiaO + 2Ha

When a solution of nitrate of bismuth is poured into solution of common salt, a white
eiyatalline precipitate is formed, which is also oxychloride of bismuth, BiCl'.BiK)*
or BiClO. It is used for paint, and is known as " pearl white." Chloride of bismuth
forms dystalUsable double salts with the chlorides oi potassium, of sodium, and of am-
monium. They are isomorphous with, and analogous in composition to, the correspond-
iog double chlorides of antimony.

DiCHLOBiDB OF BisMUTH, BiCl^ is produced by heating the trichloride with metal-
lit bismuth, also by the direct action of chlorine upon bismuth, provided the action

592 BISMUTH.

be moderated by oonfiniii^ fhe enmnt of diloriiie to the upper part of the xcCort
Partial reduction of the tnchloride is Ukewiae effected by phoaphoriu, sinc^ tin, mer-
cury, and silver. The dichloride is a brown crystalline mass eamly fiisihle and easily
decomposed by water or by a strong solution of sal-ammoniac At a hig^ tempera-
ture, it is resolYed into metallic bismuth and trichloride. (B. Weber, Pogg. Am.
crii 696.) S. A.

See TAMnmim and Wittjuhhti.

MVBOTKIW Jkn BSTnSATIOV OV« Blowpipe reac"

tions. — All bismutii-salts, and likewise the sulphide, are easily redueed bymiziiig
them with carbonate of sodium, and heating the mixtore on <»hftiwM^l in the inner
blowpipe flame. A brittle bead of metallic bismuth is thereby prodooed, and a
lemon-yellow oxide, similar to lead-oxide, but darker, is dqxMited on the char-
coal around. This deposit disi^ypears when heated in the redndng flame, witliont
colouring ihe outer flame, a character by which it is distingoiahed tnim lead, Qzida
of bismuth Ib easily reduced on charcoal without addition of sodiL

In borag on platinum-wire, bismuth-oxide dissolyes to a dear g^ass, ydHow wliile
hot| and colourless when cold, if not supersaturated ; in the latter case, jeliowiah-
red while hot» yellow when cold. In the inner flame on charcoal, the boxax-^aaa
becomes grey and turbid, afterwards perfectly clear. The addition of tm ^w*^*— it
grey at flist, but after complete reduction, colourless and transparent^

Li phoaphorussalt on platinum- wire, a small quantity of bismuth-oxide fixma a
colourless glass ; with a large quantity, the glass is yellow while hot; ooloaiiesB, or
sometimes enamel-white, on cooling. On charcoal, especiaUy with additioii of tin,
the glass is transparent and colourless wh^e hot, but becomes Uackiah-grey and
opaque on cooling. (Berzelius and Plattner.)

Liquid Seaetiont. — The salts of bismuth are mostly colourless. They hav« an
acid reaction, and their solutions when diluted with loater, become milky, and yield a
white precimtate, consisting of an insoluble basic salt^ while an add salt zemains in
solution. This reaction is best seen with the chloride, as the oxychloride farmed is
almost absolutely insoluble. Iroiif copper, lead, and Un^ precipitate bismuth fiom its
solutions in the metallic state. Sutphydric acid and sidpkuU of ammomtan thitnr
down a brown-black precipitate of tnsulphide of bismuth, insoluble in excesa of sul-
phide of ammonium. Caustio alkalis and their oarbonaUa, pAotphaUB, oxaiaUs, and
tartrates^ throw down white precipitates, insoluble in excess of caustic potash or soda.
ChromaU of potassium throws down a yellow predpitate of chrcmiate of btsmnth,
insoluble in caustic ]^tash. Soluble sulphates produce no predpitate. Thia last
character, together with the insolubility of the predpitated chromate, hydrate, Ac,
in caustic potash, distinguishes bismuth from leaiL From antimony, which rvsembles
it in the decomposition of its salts by water, it is distinguished by its behaTiour with
sulphydric add, and by the insolublility of the basic siuts thrown down by water, in
tartaric acid.

Quantitative Estimation, — The best reagent for predpitating bismuth from
most of its solutions, is carbonate of ammonium, which, when added in exoeas;
throws down the bismuth completely, provided the liquid be left to stand for some
hours in a warm place. The predpitate, after being washed and dried, must be
separated from the fllter as completdy as possible, the fllter separately burned, and
the predpitate ignited in a porcelain crueiUe ; a platinum crudble would be attacked
by it on ignition. It consists of trioxide of bismuth, BiH)*, containing 89*66 per cent.
of the metaL

If the solution contains hydrochloric add, the bismuth cannot be estimated by pre-
dpitation with carbonate of ammonium or any otiier alkali, because the predpitate ao
formed would contain oxychloride of bismuth, and on igniting it, part of^e bismuth
would be yolatilised as diloride. In this case, therefore, the bismuth must be preci-
pitated by sulphydric add, the sulphide of bismuth oxidised and dissolred by nitztc
acid, and the diluted solution predpitated by carbonate of ammonium.

Atomic Weight of Bismuth, — ^The flist approximately correct determinations of
the atomic weight of bismuth were made in 1816 byLagerjhelm (Ann. Ch. xciy.
161), who, from the proportion of bismuth in the sulphide Bi^S*, in the oxide Bi^O*,
and the sulphate Bi'XSO^)', estimated the atomic weight at 214*8, 212*8, and 2L2*3«
respectively. L. Gmelin ^Handbook, iy. 428) found that these numbers weie too
high, and that the oxide Bi^O* contained at least 10 'S3 per cent oxygen; whence

Bi« : O" « 89-67 : 10-33 ; and Bi - o^^^^ilt! "• 208*2 at most

This result was confirmed by Schneider in 1851 (Pogg. Awn, bcxzii 308). Piit«
bismuth was oxidised by nitric add in a flask (the amalfportiona of m^al cuxied -^

BISMUTH. 593

hj Ihe TapOQTS, beinff collected and allowed for), the solution eyaporated, and the
TCflidiie gently iffnited. Eight experiments thus made, showed that 100 pts. of tri-
odde of biflmn£, BiK^, contain from 10*318 to 10*366 pts. oxygen; mean » 10*345 :

whence Bi-g?gx 48-2080.

Lastly, Dnmas (Ann. Ch. Pharm. cxiii. 38), has detennined the atomic weight of
hismnxth by decomposing the trichloride BiCl* (prepared by passing chlorine gas over
bismuth, and distilling till the product passed over is colourless), with excess of car-
bonate of sodium, and estimating the cnlorine in the filtrate by means of a standard
silver-solution. Three experiments, with the purest portion of the distillate, gave
the numbers 209*88, 210*08, and 210*27. Dumas considers 210 to be the correct
number.

Separation of Bismuth from other Elements, — From the non-metallic eio-
ments (excepting eelenmm), and from the alkali'metalSf bismuth is separated by carbo-
nate of ammonium ; from the earth-metals^ and from iron, cobalt^ niekd^ and the
other metals of the second group (p. 217), it is separated by sulphydrio acid ; from
Un^ arsenic, antimony, and Murium, by sulphide of ammonium ; and from copper and
cadmium, by ammonia. The separation of bismuth from cadmium may also be effected
by cyanide of potassium, which dissolves the latter as cyanide of cadmium and potas-
siom, and precipitates the bismuth. The precipitated bismuth, however, uways
contains potash, and must therefore be dissolved m nitric add, and precipitated by
carbonate of ammonium. Another mode of separating these two metals, given by
Lowe (J. pr. Chem. Ixvii. 464), is to heat the solution containing them with acid chro-
mate of potassium, which throws down the bismuth as Bi^0*.2Cr'0', and retains the
cadmium in solution.

The separation of bismuth from lead cannot be effected by caustic potash, although
lead is soluble in that reagent, and bismuth insoluble ; for, when the metals are mixed
in solution, the oxide of lead precipitated by potash always carries some bismutli-
oodde down with it The two metab may, however, be separated : — 1. By sulphm*ic
acid. The add is to be added in excess, the solution evaporated till the excess of
snlphnric add begins to volatilise, and then diluted with water, whereupon the sulphate
of lead is left undissolved, while the sulphate of bismuth dissolves completely, pro-
vided suffident excess of sulphuric add is present The sulphate of lead is then
collected on a filter, and washed with water containing sulphuric acid, and the bismuth
is predpitated from the filtrate by carbonate of ammonium, after the excess of acid
has bean partly neutralised by ammonia. This method is not quite exact-, because
sulphate of lead is not perfectly insoluble in add liquids ; sulphuric add, however,
dissolves less of it than any other add. — 2. Another mode of separating lead from
bismutli, is to dissolve the two metals or their oxides in nitric add ailuted with a very
small quantity of water, then add hydrochloric add in suffident quantity to convert
the metals into chlorides, and afterwards a considerable quantity of strone alcohol
mixed with a little ether. The chloride at bismuth is thereby held in solution, while
the chloride of lead is completely precipitated, and may be collected on a weighed
filter, and washed with alcohol containing ether. Lastly, the alcoholic solution of
chloride of bismuth is diluted with water, the alcohol evaporated, and the bismuth
precipitated by sulphuretted hydrogen. This method becomes more exact as the alcohol
used 18 stronger. — 3. TJIlgren separates bisfnuth from lead by predpitating the two
metals as carbonates, redissolving them in acetic add, and immersiog in the liquid a
weighed strip of dean sheet-lead, which must be completelv covered by the liquid ;
the veesel is then dosed and left to itself for several hours. The bismuth is thereby
precipitated as a metallic powder. It is rinsed off the surface of the lead, which is
then dried and weighed, and the precipitated bismuth is collected, dissolved in nitric
acid, and predpitated by carbonate of ammonium, or estimated by simply evaporating
the solution and igniting the residue. The lead in the solution is also precipitated by
carbonate of ammonium, and the carbonate of lead is converted into oxide vy ignition,
and weiffhed, a deduction being made of the quantilr of lead-oxide corresponmng to the
lead which has been dissoived. — 4. When lead and bismuth are mixed in the metallic
state, they may be separated by passing chlorine over the heated alloy, chloride of
bismitt^ then volatilising, while chloride of lead remains. Great care is, however,
required in regulating the heat, as too high a temperature would voIatiUse some of the
cfauxride of le^ and if the heat be too low, a portion of the chloride of bismuth will

For the separation of bismuth from mercury, silver^ yoldf platinum, and its allied
metals, see the several metals.

Valuation of Bismuth-ores, — Ores containing only metallic bismuth, are
assayed by heating them in a crudble perforated at the bottom, and standing over a
VocL QQ

694 BISMUTH.

receiver, into which the melted metal rans. The pzoceos is not quite end^ u i muD
quantity of the metal remains mixed with the ore ; but it is sufficient for a eheck on
the results of the smelting on the lazge scale. If the ore likewise oontiiu lalpjiide of
bismuth, it is ignited with two or three times its weight of black ftnz, sometimes wiliii
addition of metallic iron, also of borax, if much earthy matter is present If tiw on
also contains other metals, which are reduced together with the bismuth, the mcitallic
button must be dissolyed, and the sereral metals separated bj analysis in the wet
waj, as aboTe described. (Kerl, Hiittenkunde, ii. 355.)

BlSMUTBv WMtlJO'BXMiiM OF. Soluble in water and deposited ss a white povder,
when the aqueous solution is evaporated. (Berselius.)

BXSanrTBf XOBBDB OV. BiP.— Obtained bj mixing 1 at itf trisdphide (A

bismuth (which has been prepared by precipitation) with 3 at of iodine, and gentlj
heating tiie mixture in a capacious loosely covered glass globe, on the sides of irbi(i
the compound condenses. The iodine simply takes the place of the sulphur (Sehnei'
d e r.) It is likewise produced by throwing iodine in small portions into a tahe ia
which bismuth is stjx>ngly heated, and distilling out of contact with the air (Weber).
It forms lai^ brilliant grey hexagonal tables, which, according to Niekl^s
(Compt. rend. L 872) are isomorphous with the tri-iodides of arsenic and antJiaoBj.
MetaUic bismuth decomposes it in ihe same manner as the tribroraid& (Weber).

An oxyiodide of bismuth, BilO, is formed when the tri-iodide is heated fbr some tiiar
in a crucible, and collects below the crystallised iodide thus obtained, in a msB of
copper-coloured rhombic laminae. In a dose vessel, it may be paitially TolitiKsed
without alteration, but when strongly heated in contact with the air, it u eonrvted
into oxide. It is not decomposed bj watcjr or by alkaline solutions ; hydrocbksie
acid dissolves it without alteration ; mtric acid decomposes it, with separation of iodisei
(Schneider, J. w. Chem. Ixxix. 424.)

A stclpkiodidej BilS, is obtained by adding to melted iodide of bismuth, as madi
sulphur as it is capable of dissolving ; it is likewise produced in the prqwiation of tbe
tri-iodide by Schneider^s method, and collects at the bottom of the tpsnI, together
with a small quantity of the iodide, in small, shining, steel-grey needles. It appean
to have the same form as the trisulphide. (Schneider, J. pr. Chem. Ixxix. 421)

ELA.

(MUTUf OauSBS OF. Bismuth forms two definite compounds with ox;^
Biamuthous oxide or tHoxide of bismuikj Bi'O', and bismuthie oxide or ank/dnii,
Bi'0^ An intermediate oxide, Bi*0^, is known, but it may be leeaided as a eompoood
of the other two — a bismuthaie of bismuth, BiK)*. Bi*0*. A dioxide, Bi*0*, appeargabi)
to exist ; it is formed when a solution of a bismuth-salt is treated with protoehloride
of tin. A corresponding sulphide is known.

BisM TTTHous OziDB, or TjuoziDB OF BiSMUTK, BiK)*, IB formed when the metal ii
roasted in air, but is b^t obtained by gently igniting the subnitrate. It is a pale ydkw
powder, which melts at a red heat, and soHdifies on cooling to a glass having a dteoti
yellow tint It occurs native, as bismuth-ochre^ associated with iron and some other
impurities (Bi*0« 86*4 per cent; Fe*0« 5-1 ; C0» 4-1 ; water 3*4). at Schned)«g in
Saxony, at Joachimsthal in Bohemia) and with native gold at Beresof in Sberia
(Dana, ii. 141.)

The hydrated oxide of bismuth, BiHO*. or BiK>*HH), is obtained as a white pr«i»
fate when a solution of subnitrate of bismuth is decomposed by an alkalL If w
hydrate be boiled with potash, it loses water, and is changed into a yellow ayStaBiBe
powder which is the anhydrous oiide.

The hydrate is occasionally used in analysis for converting into oxides eeiiiiB
metallic sulphides soluble in alkalis. For this purpose, the alkaline solutions are boikA
with the hydrated oxide.

Both the hvdrate and the anhydrous oxide dissolve in the stronger acids, tonnnig
the normal bismuth salts, which have the composition Bi'TA', the symbol A denote
ing an acid radicle, e^ g, ".

Bia»; Bi(NO«)» = ^ B^-^'l 0»; Bi^SO*)* « [b^^^Ho*. &«•

Many of these salts crystallise well, but cannot exist in solution unless an exeess (<f
acid is present On diluting the solutions with water^ s basic salt is predpitaled, and
an acid salt remains in solution.

BiSKiTTHXC OxroB or Akhtdhidb, Bi*0* ;— in combination : Bismrrroc Acra.— Pre-
pared bv passing chlorine through a concentrated solution of potash which contami
hydrated trioxide of bismuth in suspension. A blood-red substance then sepanta^
which is a mixture of hydrated bismuthie acid, and trioxide of bismuth. This is treated

BISMUTH. 595

with dflate nitric acid, vhich dissolTes the oxide, but, in the cold, does not attack- Uie
and.

Bismnthie oxide is a bright red powder, which loses part of its oxygen at a tempera-
ture little aboTe 100^ G. and becomes converted into the intermediate oxide, Bi*0\
bismathate of bismuth. Acids also decompose it> reducing it to the state of bismuthous
oodde, which then combines with the acid.

The bismuth ate s are little known, and of no importance; according to Arppe,
bismathic acid ^tibb with potash, a salt which is an aeid bismvihaU of potassium :
Bi»KHO« - BiKO*.BiHO». K A.

OZTCB3bOBI]» OV. (p. 591.)
03CTCm-SA&T8 OF. See the several acids.

I OV* Melted bismuth takes up a small quantity of
phosphoms, being thereby rendered more brittle and less laminar. Phosphoretted
liydzt)gen gas throws down from solution of nitrate of bismuth a black phosphide of
the metal, which gives off all its phosphorus by distillation, (Berzelius.)

BHimi'l'Mf SHUnrXBB OV« Bismuth and selenium unite when heated toge-
ther with faint evolution of light and heat, and form a silver-white mass, having a
crystalline fracture, and fusing at a red heat : the fused mass has a specular surface.
(Berzelius.)

mmiUTM, 8UUNUDB8 OV* Bismuth readily unites with sulphur. When
the two substances in fine powder are fused together, uiey combine, with disengage-
ment o£ heat Two distinct compounds are known.

DIS17X.PHIDI ojf BinnrrH, Bi'S. — ^According to Wertheim, it is obtained crystallised
by melting together bismuth and trisulphide of bismuth in ec^uivalent quantities. The
mixture is then allowed to cool slowly, on which the sulphide crystaUises from the
liquid metal, which may be poured off from the crystals.* More recently it has been
shown that these crystals, although giving by analysis numbers corresponding to BiS,
are really a compound of trisulphide of bismuth with metallic bismuth. According to
Sehneidi^, disulphide of bismuth may be prepared in the moist way, by mixing an
alkaline solution of bismuthons oxide with an alkaline solution of stannous oxide, and
praeipitating with sulphuretted hydrogen. The tin remains dissolved, and a black pre-
cipitate is formed, which, when washed and dried in the water-bath, is found to have the
oompoeition BiS.HH). It is a black lustreless powder, which, under the burnisher, takes
the fixrm of black lamina.

TBisfii.pHiDB OF BiBicuTH, Bi^S', occuTS native as bismuth-glance, or bismuikine, in
Cnmberiand and Cornwall, also in Saxony, at Bastnas in Sweden, and according to
Shepard, at Haddam in Connecticut, associated with chrysobeiyL It crystallises in aci-
cular prLnns of the trimetric system, isomorphous with native sulphide of antimony.
« P . ao P 00 . 00 Poo . 00 P 3 . oP. Inclination of oo P : oo P - 91° .30', Cleavage
perfect parallel tc oP and oo I^ oo ; less perfect parallel to oo I* oo . It occurs also
massive, with foliated or fibrous structure. Specific gravity 6*4 to 6*55. Hardness
« 2 to 2'6. Opaque, with metallic lustre, lead-grey colour and streak. Sectilu.
(Dana, ii. 33.)

The same compound is prepared in the dry way, by fusing pulverised bismuth with
one-third of its weight of sulphur, and removing the excess of sulphur by a second
fusion. A laminated mass is thus obtained, composed of crystals having the same fonn
as the native sulphide. According to Marx, it expands to the amount of one-fourth its
Tolume in solidifying. The trisulphide is also obtained as a brown-black precipitate,
when snlphydric acid gas is passed into the solution of a bismuth'Salt. £. A.

miMtUTH, BV&VBOCnBMMUBB OF. BiSCl, or BiCl*.Bi-S^.— This com-
poan<i 15 best obtained by gradually adding pulverised trisulphide of bismuth to
melted ammonio-biBmuthous chloride (2NH*Cl.BiCl'), and washing the resulting mass
with water acidulated with hydrochloric acid. It is also fonned by heating the same
doable chloride with sulphur, or in sulphydric acid gas. It fmtns small, metallic-
shining, blue-grey crystalline needles, which yield a rod powder. Heated in carbonic
acid ipia, it gives off chloride of bismuth and leaves the sulphide ; heated in hydrogen,
it ^▼es off hydiochlorie and snlphydric acids, and leaves bismuth. It is decomposed
by strong hydrochloric and strong nitric acid ; also by alkalis, which remote the chlo-
rine and leave an oxysulphide. (B. Schneider, Pogg. Ann. zciiL 464<)

Tmsuaaaa* Bi^Te. See Tblluaivk.

TSKliirSISB OV, The two metals unite in all proportions by

Native silicate of bismuth. Sec Silicates.
or BZflBRTTBZn. Native trisulphide of bismuth
jkboTe).

QQ 2

696 BISMUTH-RADICLES, ORGANIC.

Orunamte, Saynite, — A sulphide of bismuth and nidLdt
foand, together with quartz and copper pyrites, at Gruxxau in Sajn Altenkizdien,
crystallised in regular octahedrons, sometimes perfect, sometimes haying the saminits
more or less replaced by faces of the cube, deayage octahedraL Specific gravity
5*13. Hardness 4*6. Colour, light steel-gre^ to silver^white, often yellowiah or grejiah
from tarnish. Its composition in 100 parts is given by the following analyses :

S Bi Ni Fe Co Cu Pb

38*46 1411 40*65 3*48 028 1*68 1-58 ' EobeH

31*99 10*49 2203 655 11*24 11*69 711 Schnabd.

8310 10-41 22-78 606 11*73 11*66 4*36 „

Before the blowpipe it melts to a gKy* brittle, magnetic globule, coloaring the <
coal greenish-yellow. Bissolres in nitnc acid, excepting the sulphur. (Dana, iL 44.)

BZSMUTB-OCHXB* Native triozide of bismuth (p. 694).

»ISlftUTII"^MiM>ICXigS, OSCkAJriO. The only compounds of this cLafls as
yet obtained, are the JBismutkides of Ethyl, viz. BisMetkyl, disooreied by Lowig
and Schweizer (Ann. Ch. Phann. Izxy. 366), and further examined b^ Breed (ML
Ixxxii. 106), and Bisethyl, disooyered by Dunhaupt in 1864 {ibieL xdi. 372).

BisBTHTi.. Cn*Bi.— The chloride of this radicle, CH^BiQ* (?) is obtained, together
with a precipitate of chloride of hydraigethyl, by the action of bistiiethyl on chloride
of mercury (p. 696). The chloride of bisethyl remains in solution and may be obtained
by spontaneous evaporation in crystals, which however do not dissolve oom^et«lj in
water, but leave a white powder. On adding iodide of potassium to the aqueous solu-
tion, then diluting with water till turbidity is produced, boiling till the solnticm be-
comes clear, and leaving it to cool, iodide of biseihvl separates in yellow six-sided
laminse, which appear to hav« the composition CH'BiP. A solution <^ this componad
in hydrated alcohol treated with ammonia^ forms a yellowish-white precipitate of the
hydraUd onde^ which, after drying in vacuo, ignites spontaneously in the air, gEving tM
a dense yellow vapour. The oxide appears also to be formed by the roontaiieous
oxidation of bistriethvl, 2 atoms of ethyl being eliminated. Sul^kids oj bueHkyl im
formed by treating the iodide with sulphydric acid ; and the mtrate and sa]pihate>
by acting on the i^de with the corresponding silver-salts. (Diinhaupt^)

BisTBiBTHTL, or TuBTHTL-BisiTUTHnra. (CH')'BL BitnuihyL — ^Formed by the
action of iodide of ethyl on biBmuthide of potassium.

Preparation, — ^Bismuthide of potassium, finely pounded, and without admixtixi« td
sand, is introduced into a small flask ; iodide of ethyl added in excess ; the flask dosed,
and immediately connected with a long narrow disullation-tubo passing into a reoeivR'
surrounded with ice, all tiiese manipulations being performed as quickly as poerableL
In a few minutes, the action begins, the mixture becomes heated, and the ezoeas of
iodide of ethyl distils over. Water free from air is then introduced into the flask.
which is immediately closed and heated in the water-bath, till the mass becomes soft
and the iodide of potassium is dissolved. The same operations are repeated with a
considerable number of flasks ; the disintegrated contents transferred as quickly as
possible into a large flask filled with carbonic anhydride ; shaken up several times with
a large quantity of ether ; the ethereal solution mixed with the de-aerated water ; and
the ether completely distilled off in the water-bath. The bistriethyl renmins at the
bottom of the water, and is purified by distilling it with water (it cannot be disdUed
alone, without decomposition), shaking it up with a small quantity of dilute nitric acid
to free it from oxide, and diyiuff over chloride of calcium. During all these operatioBa,
the air must be carefully excluded (Breed). 3 lbs. of bismuthide of potaasisHi and
1 lb. of iodide of ethyl, yield 4 or 6 oz. of pure bistriethyl (DunhaupL)

Properties, — Transparent, very mobile liquid, sometimes colourless, bat often slightly
tinged with yellow. Has an unpleasant oaour like that of stibtriethyl, and itsvaposs;
when inhaled, even in small quantity, produces a veiy disagreeable boniing sensatioa
on the tip of the tongue (Breed). Insoluble in water, sparingly soluhle in etiiea;
readily in absolute alcohol.

DecompositioTis. — 1. Bistriethyl heated in a retort, begins to boil at about 60^ CL,
giving off a gas free from bismuth, which bums with a dear flame, while metallic fais-
muth separates out in the retort If the heat be continued, the thennometcr rises
above 160^ C, and continues to rise till a sudden and violent explosion takes place,
which shatters the apparatus (B re e d). The dilute ethereal solution is also decomposed
when left to evaporate in the air, leaving a white residue of hydrated oxide of bismvtii
(Biinhaupt). — 2. Bistriethyl exposed to the*air, gives off thick yellow vapours and
takes fire with slight explosion, difihsing a dense yellow smoke of bismuth-oxide ; tliis
effect is best shown by moistening a piece of filtering paper with the liquid and ex-
posing it to the air. — 3. Fuming nitric acid decomposes bistriethyl, with escplosion

BISMUTH-SILVER — BITTER-ALMOND OIL. 597

TiTid eombiutioiL-^. Bistriethyl bonis in chlorine gas vith separation of charcoal,
and takes fire in contact with bromine. In genezal, its reactions resemble those of
sdbtriethyl (Breed). — 5. Bistriethyl added to solutions of metallic salts (e.ff, to
nitrate of silver or oonosiTe sablimate), does not simply throw down the oxide, but is
itself decomposed. On adding an alcoholic solution of bistriethyl to a not too dilate
solution of protocfaloride of mercuiy, the former being poured slowly and with constant
stiiring into the latter, a Teiy lai^ precipitate of mercurous chloride is immediately
obtained, chloride of bismuth and hydrochloric ether being doubtless formed at the
same time. But if the process be reversed, and a hot dilute alcoholic solution of cor-
rosive sublimate be poured in a thin stream and with constant stirring into a dilute
akoholie solution of bistriethyl to which a few drops of hprdrochloric acid have been
added, to pr^ent separation of oxide of bismuth, no precipitate is formed at first ; but
alter some time, a bulky precipitate i^pears, which however is again completely dis-
aohred if the liquid be heated. The reaction is terminated when a drop of the liquid
DO longer produces a white precipitate in a solution of corrosive sublimate ; by a httle
care, it may be airanged that neither Uquid shall predominate. If the liquid be then
he^ed on the water-bath till it becomes perfectly clear, separated, if necessary, from a
small quantity of metallic mercury by decantation, and then left to cool, li^lit, crys-
talline, silveiy, iridescent lamime separate out and graduallv fill the whole fiuicL These
crystals consist of chloride of J^drargeihyl, CH^H^Gl ; the solution from which they
are deposited contains chloride of Htethyl, CH^BiCl* (Diin haupt) :

(0»H»)«Bi + 4Hga « 2C«H»Hg»a + C»H»Bia«.

Combinations. — ^Bistriethvl combines with Bnymne^ Iodine^ Sidphur, &c ; but the
eompoonds are lees stable tnan those of stibtriethvL

Brondde of Bistriethyl appears to be formed when bromine is added to an alcoholic
■oliition of bistriethyl ; but the solution deposits bismuth when evaporated.

Iodide of BiatriethyL — ^When iodine is added to an alcoholic solution of bistriethyl,
heat is evolved, the colour of the iodine disappears; and iodide of bistriethyl is formed.
This compound is less stable than iodide of stibtriethyl ; when its alcoholic solution is
left to itself for a while, iodide of bismuth separates out. (Breed.)

An iodide having the composition C«H"Bi«I», or (C*H»)"BiI«.Bi«P, is obtained by
adding iodine to a tolerably strong alcoholic solution of bistriethyl, tall its coiour [no
k>nger 7] disappears, filtering from the precipitate, and adding to the filtrate a large
qnantity of water at 4CP C. A small quantity of a ruby-coloured Uquid separates ; and
if the wateiy liquid be poured off from this, a large quantity of beautiful red needle-
shaped crystals are formed as it cools ; these must be immediately collected and dried
in vacuo. The same compound is formed when bistriethyl is left for a considerable
time in contact with dilute nitric acid and then mixed with iodide of potassium. It is
sparingly soluble in water, but dissolves pretty readily in alcohol and ether ; the solu-
tions nave a pale yellow colour. The compound heated on platinum foil gives off
a strong yeUow vapour which takes fire on coining in contact with fiame. (Biin-
hanptb)

Another iodine-compound, having the formula (C'H*)*Bi.2C*H*I, is contained in the
abore-mentioned ruby-coloured liquid ; but it is ver^ instable. (Diinhaupt.)

Stdpkide of Bistriethyl, has not been obtained m the separate state, bistriethyl
which has bc«n long exposed to the air under water, gives with sulphuretted hydro-
gen, first a yellow, then a brown precipitate, consisting of ((>H*)*BiS.Bi^. (jDun-
havpt.)

» I B 11 V'l'H gTTiTIIW A mineral sometimes occurring in acicular or capiUaiy
ciystallisations, but more generally amorphous, as at Schapbach in Baden ; it is found
also in the cupreous shale of Mansfeld, Tnuringia. It is soft and sectile, opaque, with
metallic lustre and tin-white or greyish colour, subject to tarnish ; fracture uneven.
Contains, according to Klaproth's analysis, 27 per cent bismuth, 33 lead, 15 silver,
4*3 iron, 0*9 copper, and 16'3 sulphur. A bismutk-siltfer from the mine of San Antonio
near Cc^ipo, Chili, was found by Domeyko to contain 60*1 per cent, silver, 10*1 bis-
muth, 7*8 copper, 2'8 arsenic, and 19'2 gangue. It occurs disseminated, and has one
or more imperfect cleavages, and is probably either monometric or rhombohedral.
(Dana, ii 16.)

Kative carbonate of bismuth. See Cabbonatbs.

A gum resin from Arabia^ resemblinic myrrh. (Y a ugh an,
Pharm. J. Trans, xii. 227.)

BZSVBB. A brown pigment, consisting of the finer parts of wood-soot, separated
from the grosser by washmg. The soot of beech-wood is said to yield the best bistre.
(See Ur/s Dictionary of Arts, Manufactures, and Mines, i. 307.)

A peculiar volatile oil obtained by distilling bitter-
QQ 3

598 BTTTER-ALMOND OIL.

almonds with, water. It was discovered by Martr^ in 1808 ; Stange showed that the
cnrstallised acid which is produced from it is benzoic add ; Bobiquet^ and liebig and
Wohler explained its formation ; and Liebig and Wohler (1^2, Ann. Ch. Phaio.
zxii 1) first fiillY examined it. It is also obtained from the amygdaliloonB parts of
most Pamea and Amygdaiem ; from the leaves of the cheny-lanrel (Gmuw Iomto-
eerasut), and of Cerasus padtUy from peach and ehen^-kemelB, &cl It is ponUs
that many of these oils are not identical, bnt isomeric^ with bitter«lmond oil, and that
it is owing to their presence that different specimens of the commercial oil yield vith
the same reagent such different results. The chief oonstitaent of the oil is hjdzide of
benzoyl, always accompanied by hydrocyanic acid and other oomponnds (see Bsiaon^
HTDRron of). The ou does not exist i«ady-formed in bitter-almonds, but isprodaeed
by the action of water and a peculiar ferment^ emuUin or syfu^»tet«, upon tbe
amygdalin contained in the almonds, whieh is thereby conTerted into hydride of ben-
zoyl, hydrocyanic acid, and glucose-:

(PH^'NO" + 2H«0 « CH'O + CNH + 2(yE}H);

Amygdalin. Hydride Glucose.

of beaxoyl.

The oil is thus prepared : Bitter-almonds are crushed, and fr«ed from fixed oil hj
cold pressing, then stirred up to a thin paste with 4 — 6 pts. cold or lukewarm water,
and the mixture allowed to stand for twenty-four hours before distillation. If dis-
tilled over the open fire, it is very apt to froth over, unless it is stirred oontinnallj;
for this reason it is best distilled with vapour of water. This maybe done byoorenog
the bottom of the still with a thick layer of coarse sand saturated with water, and
pouring the almond-paste upon it. The frothing may also be avoided by removing
most of the solid matter before distilling. The first portion of the HiafilUfft u ricfaeet in
oil, and in hydrocyanic acid also, and is therefore clear; the latter portions, oontainioK
lef» hydrocyanic acid, are milky. The distillation is continued as long as the liquid
which comes over smells of bitter-almonds ; the oil in the receiver is Sien aepanted
from the wat<er, which, as it contains a good deal of oil in solution, is again dietilled,
when the oil passes over with the first portions of the water. The addition of chloride
of sodium faolitates the separation of the oiL 1000 pts. almonds do not yield mora
than 7 or 8 pts. oiL

Bitter-almond oil is colourless when freshly prepared, but soon becomes yellow; it
has a peculiar strong aromatic smell, besides that of prussic add, and a bnnung taste ;
is heavier than water ; boils at about 180^ C, and bums with a smoky flame. Its poi-
sonous action is entirely owing to the presence of prussic acid. (For methods of puri-
fying the oil, see Bsnzoti., Hydbidb of.)

Bitter-almond oil was formerly much used in perfumery, but it is now replaced in
great measure bv nitrobenzene {essence de Mirbane). Being an enwnsiTe article, it is
very liable to adulteration, usually with alcohol (which, if added m moderation, doei
not materially affect its smeU), light ethereal oils, or nitrobeosene. Light oils, vhoee
smell is masked by that of hydride of benzoyl, may be detected by aUowing the latter
to oxidise into benzoic acid by exposure to the air, when the smell of the former be-
comes evident, or by their effect on the specific gravity of the oil, a method whieh
applies to alcohol also. Alcohol may also be detected by agitating the oil with twice
its volume of nitric acid of specific gravity 1*42 ; with unadulterated o3, no immediate
action is produced ; but, if 8 — 10 per cent, alcohol be present^ red fumes are giTen off
with effervescence. By using acid of 1*5 specific gravity, as little as 3 — 4 per cent
alcohol mav be detected (Redwood). A good reazent for detecting adultentioos is
a strong solution of an acid sulphite of alkali-metal, i^ch dissolves the pure oil entirely,
but leaves behind all impurities which are not of the nature of aldehydes.

Owing principally to the presence of hydrocyanic acid, bitter-almond oil behaves
with sevezul reagents differently from hydride of benzoyl. By heat and bj oxidising
agents generally, e.g. oj nitric acid, it is acted on in the same manner as hydride of
benzoyL With sulphuric acidf it yields stilbous acid, and (perhaps) benzoate of hy-
dride of benzoyl. A mixture of Nordhausen sulphuric acid wi& bitter-almond oil
yields, on addition of water, a crystalline body, which presents the properties of man-
delic acid. Dr^ chlorine acts upon it as upon hydride of benzoyl ; with moist chlorine
it forms stUbesic acid and hensocUe of hydride of benzoyl. To this latter compound,
which is frequently r^arded as identical with stilbous acid, Liebig assigns the fb^
mula C^«H'«0* - 2C'H«0 + C'H«0«. Bitte^almond oU saturated with moist chlorine
solidifies finally to a crystalline mass, which, when washed witii cold ether, leaves this
compound as a crystalline powder. It is insoluble in water, slightly soluble in cold
ether, abundantly in alcohol. When heated, it melts and volatilises nndecomposed.
Heated with alcoholic potash, it yields potassic benzoate. With hydrochlcric acH it
yields either hydrocyanate of hydride of benzoyl or mandelic acid. With chloride of

BITTER- ALMOND WATER— BITTER SPAR. 699

mipktirf it yields stilboiia acid. With svipkide of ammonium, it yields hydride of
thiobeiiioyl, hydride of sulphosobenzoyl, and solphydrate of azoLenzoyL With bi-
amiphide of cturbon and ammonia, it yields sulphocyanobenzylene. With cyanide of
j^otagnwrn^ it yields sometimes benzoin, sometimes benzamide. Solid potash converts
it into benzoic add ; aqueous or alcoholic potash (especially the latter) into benzoin.
With am$iumia, it yields very yarious products, according to circumstances ; these are azo-
bensoide, azobcnzoidin, azobenzoyl, benzamil, benzhydramide, benzoylazotide, diben-
xoylimide, hydrobenzamide, stilbazide. Host of these compounds were discovered by
litturentk and many are yeiy imperfectly knewn. Baryta- <a lime-water converts it
into beoasoin. F. T. G.

Bl'rTMgi^ h Tilff HM B ^ITATHR. A pharmaceutical preparation, employed in
medicine, oonsiBting of a solution of bitter-almond oil in water. It is prepared in the
same manner as bitter-almond oil ; but, since the water must be of a known strength,
the quantity of almonds and water to be employed and of distillate to be collected is
fixed by the pharmacop(Bi& These Quantities vary in different pharmacopoeias : in the
Prussian, 2 Iiw. almonds are pressed and macerated with 10 lbs. water^ 4 ozs. alcohol
aidded, and 2 lb& of distillate collected. The Parisian pharmaco^ia collects 2 lbs*
the Saxon 3 lbs. of distillate for each pound of almonds. The addition of alcohol does
not seem to have any advantage. Heat must be carefully avoided in the pressure and
maceration of the almonds. Bitter-almond water is generfdly a more or less milky liquid,
smelling and tasting strongly of crude bitter-almond oil ,* it decomposes by exposure to the
air, and must therefore be kept in stoppered bottles completely fulL Its strength is very
imcertain, howerer closely the pharmacopoeia directions are adhered to. It is usually
Talued by the amount of prussic acid which it contains, which may be readily deter-
mined by Liebig's volumetric method (see HTDRocTAino Aero, under Gtakoosn) ; the
Prussian pharmacopoeia requires it to contain 0*14 per cent, prussic acid. Laurel-water,
prepared from laurel leaves, and cherry-water from wild cherries, contain the same
constituents as bitter-almond water. The latter may be distinguished from laurel-
water by becoming nulky immediately on addition of ammonia, au effect which is
not produced on laurel-water till after some time ; or, according to Lepage, by chloride
of gold, which giyes with both waters a yeUow colour, which, in bitter-almond water,
dirappears in eight hours, while in lanrel-water it remains for twenty-four hours. (J.
Ch, mW. xxiv. 366.) F. T. C.

miVTJUi ysnroIPabBa Many vegetable substances yield bitter extracts, which
were formeriy supposed to contain a common constituent, called I^ncytium amarum.
More exact investigation havine shown, however, that many of these vegetable bitters
are definite chemical compound of voxy various composition, e.a, picric acid and the
yegetable alkaloids, the term bitter principle is now restricted to the brown amor-
phous bitter extractive matter obtained from many plants by boiling with water,
evaporating the extract to dryness, exhausting| with hyarated alcohol, evaporating, and
teeating the residue with absolute alcohol, which dissolyes resins, &c, and leaves the
bitter substance undissolved. The products thus obtained, are not| generally speaking,
of definite constitution. From some plants, however, more definite bitter principles
are obtained, e. g, asbinthin from wormwood, ahin from aloes, &c.

azmUf • The mother-water which remains after the crystallisation of common
salt from sea-water or the water of salt-spring. It contains a considerable quantity
of sulphate and chloride of magnesium, to which its bitterness is owing, also more or
less Inomine and iodine.

or SSOMBSVAX. JBrown-epar. Pearlspar. Talc-epar.
Dolomite. Chaux carbonatU magnSeifhe, — ^This mineral crystallises in rhombohedrons,
which were formerly confounded with those of calcspar, but differ in the angles, the
primary form being an acute rhombohedron of 106^ 18', and 73^ 42' (mean). The
crystals are eeneralfy rhombohedrons K, with more acute or more obtuse rhombohedron
in combination, the base OR and the hexagonal prisms ooB often occurring. The
rhomb R generally has its fhces curved like a saddle ; ^ R is more generally lenticular.
Cleavage parallel to R. Fracture conchoi'dal, uneven, splintery, and earthy. Colour
white, grevish, or yellow, with a somewhat pearly lustre. Rarely transparent, but ex-
hibits various degrees of translucence down to cdmplete opacity. Hardness 3*5 to 4*5.
Specific gravify 2'8 to 3*0. Its formula is (Ca' ; Mg')CO*, the calcium and magnesium
replacing one another in any proportion, so that it presents all varieties of composition,
from that of calcspar to that of magnesite. Iron (ferrosum) and manganese {manga-
nosum) also occur, replacing the other metals in subordinate proportions. In the state
of powder, it dissolves readily in warm hydrochloric acid, but in lumps the acid scarcely
acts upon it. Before the blowpipe, it becomes caustic, but does not melt. It is
usually imbedded in serpentine, chlorite, or steatite, and is found in the Tyrol, Sulz-

Q Q 4

600 BITTERSWEET— BIXIN.

bug, and Daaphiny ; in SeotLand, on the borden of Lodi Lomond, in chlorite daU^
and near Newton Stewart in Cbdloway, also in the lale of Man. It bean the tuae
relation to dolomite, or massive magnesian limestone^ that calcBpar bean to eosuBoa
limestone.

Stipites Jhdcamara, The stems atSolanftm Duleamara {(^.t.)

This term includes a considerable number of inflammable minenl
substances, mainly consisting of hydrocarbons. They are of Tarious consistence, from
thin fluid to solid, but the soUd bitumens^re for the most part liquefiable at a modente
heat The purest kind of fluid bitumen, called Naphtha, or Bock-oU, is a oobukss
liquid of spedfle gravity 0*7 to 0*84, and with a bituminous odour. It often oocim in
nature combined with asphalt and other solid bitumens. Petroleum is a dark-coloand,
fluid variety containing much naphtha. Maltha or mineral tar ia a more viBcid
variety. The soUd bitumens are Asphalt^ already described (p. 426), Mineral tallow,
or Hatchetin, and Elastic bitumeiif Mineral CaotUchoue or BXeUerite, (See the serenl
substances in alphabetical order. For the practical uses of bitumen, see Ur^i Bietton-
ary of Arti^ Manufacturea and Mines, i. 308.)

BZmUiT. C«H»N»0« (dried at 100<' C); C«H»NH)«.H-0 (ciystalli»ed).-A
product of the decomposition of urea and nitrate of urea. It is isomeric with
acid cyanate of ammonium, 2CHN0.NH', and may be regarded as a seeondaiy

amide, N < ' rr ' , whereas urea is a primary amide containing the same ndide^

N I TT2 ' and isomeric with neutral cyanate of ammonium, CHNCKH*.

The formation of biuret from urea is represented by the equation

2CH«N«0 « C«H*N«0« + NH».

Ures. Biuret.

To prepare it, urea is melted in an oil-bath for some time at 150^ to 170^ C. ; and «
soon as the evolution of ammonia ceases and the residue becomes pasty, this reaidiie
is treated with a very small quantity of boiling water; the liquid, after filtntioii,
is precipitated by a solution of subacetate of lead ; the precipitate, consisting of cyun-
rate and ammelidate of lead, is separated by filtration ; and the liquid, after being
treated with sulphuretted hydrogen to remove the excess of load, and again filtered, is
evaporated till it crystallises. Biuret is then deposited in sn&all granular oystab,
which may be purified by recrystallisation from water. It ia alao obtained, thon^
in small quantity, by the action of heat upon nitrate of urea.

Biuret dissolves very easily in water and in alcohol, and oyBtallises from the latter
liquid in long anhydrous lea^ crystals, and from water in hydrated erystals, whidi
give oS their water of ciystsllisation when exposed to dry air or dried at 100' CL It
dissolves without decomposition in cold strong sulphuric acid, and is not altered hf
boiling with nitric acid, unless the acid is very strong. Its solution is notpreripitated
by lefl^ or silver salts, by gallic acid, or by tannin. On adding a few drops of a soln-
tion of copper salt to a solution of biuret, and then a slight excess of potash, a deep
red colour is produced. This reaction takes place also wit£ solutions of biuret in aa<£i
or in ammonia, and affords a very delicate test of its presence. Biuret when heated,
melts, gives off vapours of ammonia^ and ultimately leaves pure cyanurie arid:

3C«H*N«0« « 20»H»N«0» + 8NH».
(Wiedemann, Fogg. Ann. Ixxiv. 67.)

BXXZV. A colouring matter contained, in annotto (the red paste obtained hj
crushing the seeds of the Bixa orellana). According to Chevreutannotto contains
two colouring matters, viz. orellin^ a yellow dye, soluble in water and alcohol, but spa^
ingly in ether, and bi^n, an orange-coloured dye, sparingly soluble in water, easily in
alcohol and ether. According to Kemdt, bixin is C**H*0^ and when exposed to the
air, and in the moist state, is partly converted into orellin. According to Freisser,
Ann. Ch. Fharm. lii. 382), bixin is obtained in small slightly yellowish aystak, \ij
treating lumps of pure annotto witlv carbonate of sodium, precipitating with basie
nitrate of lead, decomposing the precipitate with sulphuretted hydrogen, and eraporat'
ing the colourless filtrate. It is bitter, soluble in water, alcohol, and ether, volatile
when heated, turned yellow by sulphuric and nitric acids, orange-yellow by chromic
acid. Treated with ammonia in contact with the air, it is converted into a durk red-
brown substance, hixtin, which is the red-colouring matter of annotto. It combines
with lead-oxide and alkalis, and is turned blue by sulphuric acid. (Freisser.)

According to Girardin (J. Fharm. [3] xxi. 174), the name of bixin is applied
commercially to a variety of annotto, having six to ten times the colouring power of

BLACK BAND— BLRACHING. 601

common annotto, a saperiority which it appears to owe to a quicker process of
eztnetion.

A Tsriety of carbonate of iron. See Ibom and Cabbonatbs.
This mineral has a blnish-black colonr, a slaty texture, soils
the fingers, and is meagre to the toach. It contains about 64 silica, 11 alumina, 11
carbon, witii a little iron and water. It is found in primitive mountains, and also some-
times near coal formations. It occurs in Caernarvonshire and in the island of Isla.

lCK JACXm The miners distinguish blende, or mock lead, by this name.
It is an ore of zinc.

U See GiuPHiTB and pLUMBiLGO.

\m One of the ores of manganese.

The name of an alkaloid said to exist in China blanoa,

A kind of crude soda, less powerful than barilla, obtained at
Aigues-Mortes, by the incineration of SaUola Tragtu and 8, Kali,

a&AFB OBTUBA. This insect contains, according to Hornung and Bley {J.
pr. Chem. vi 237), a red colouring matter, fatty and volatile oil, resin, formic acid,
uie acid, nhitin, wax, and other constituents.

B&BACBnrCk The chemical art by which the various articles used for clothing
are deprived of their natural dark colour and rendered white.

The oldest method of bleaching, which is still practised in some localities, and for
particular kinds of goods, especially for hempen and flaxen goods, consiBts in extending
the tissues on the grass of a meadow, so as to expose them for some days to the
unitod action of light, air, and water, then washing them in alkaline ley, and repeating
this series of operations a considerable number of times.

This mode of bleaching is effective, but slow, and involves a great amount of
labour. About 1785, Berthollet proposed the use of chlorine for bleaching vegetable
tisBuos ; but its introduction met with considerable opposition from manufacturers,
because the mode of applying it being but imperfectly understood, its action was un-
(^rtain, and moreover it was found to injure the tissues ; gradually, however, these
difficulties have been overcome, and the use of chlorine for bleaching cotton goods has
entirely superseded the old method. Chlorine was first used in the form of aqueous
solution ; idltervards solutions of chlorine in caustic akalis, that is to say, solutions of
hypochlorite of potassium or sodium, the so-called chlorides of potash and soda, were
used ; but these compounds are now almost entirely superseded by the hypochlorite of
calcium, the so-called chloride of lime or bleaching powder. This substance is prepared
on a la^e scale by exposing slfdced lime to the action of chlorine gas, whereby a solid
mixture of hypochlorite and chloride of calcium is produced. It is soluble in water,
and the solution is used for steeping the ^oods to be bleached. By itself it exerts no
bleaching action whatever; but by exposing the fabrics wetted with it to the action of
the carbonic acid in the air, or more quickly by steeping them in a bath of dilute sul-
phuric or hydrochloric add, the salt is decomposed, and the liberated hypochlorous
acid exerts its bleaching action on the tissues.

The strength of the chlorine-liquor is a matter of great importance. The stronger
the liquor, the more rapid will be its action ; but on the other hand, the greater will be
the chance of ii^jury to the goods. In practice it is not found safe to use a solution
ffifir^ing more than 2^ or 3° of Baum^'s hydrometer, or |° of Twaddle's, corresponding
to specific gravity 1002*5 ; and even this must be carefully removed by subsequent
washing, and in some cases by the use of hyposulphite of sodium or other antichlors.
(See AifncHLOB.)

Wool and silk are for the most part bleached with sulphurous acid, chlorine and
the hypochlorites being found to exert an ix\]urious action upon them.

The rationale of bleaching is not thoroughly understood, but the most probable expla-
nation of the action is, that it is due in tdl cases to oxygen in the peculiar active form
called ozone. That active oxygen does possess this bleaching power is well-known :
witness the action of peroxide of hydrogen on vegetable colours. Now in the old
method of bleaching by exposure, light is an essential element of the action, the
bleaching taking place much more quickly in sunshine than under a clouded sky. But
Schonbein's investigations have also shown that ordinazy atmospheric oxygen passes
into the active state under the influence of light and moisture. Chlorine abstracts
hydrogen firom the colouring matter, and the oxygen thus set free produces the bleach-
ing action. The action of sulphurous acid appears at first sight to be apposite to
this, viz. deoxidising ; but it is known from Schonbein's investigations, that an aqueous
solution of sulphurous acid or an alkaline sulphite exposed to air and light quickly
brings a portion of the oxygen in contact with it into the active state ; hence also the
bleaching action may in this case be due 'to oxidation. Sometimes, however, thA

€02 BLEACHING.

Bulpborous acid appears to unite directlj with the colonriog matter of ibe tisroe to
form a colourless compound.

The actual process of bleaching bj means of chlorine or sulphazoiB acid is alvays
preceded or accompanied by certain cleansing operations, consisting in waahiag with
water, and boiling with alkaline leys or soap, the object of which is to remoTe n-
sinous, fatty, and other impurities, either natural to the ftbre or introduced aoeidBat>
ally or intentionally in the course of manufnctoie. All these substances impair tiie
whiteness of the fabric, and often interfere greatly with the processes of djdng and
printing. Indeed, their lemoval by the means above mentioned, oonstitates a Toy
important part of the bleaching process, a laige portion of the colouring matter bemg
got rid of at the same time, so that the chlorine or sulphuroos add serres to gire only
the last finish. Cotton and linen goods are cleansed by washing with watsr and
boiling with alkaline leys : formerly potash and soda were used for the ptupose, bat
they are now nearly superseded by lime, at least for the first deanaiD^ as this sab-
stance, besides being much cheaper than the alkalis, is less likelv to injure the &bric.
Silk and wool are deansed by scouring or boiling with water and soap, as they caimot
bear the action of pure alkaline solutions.

Bleaching of Cotton. — The series of operations in the bleaching of cotton, may be
thus generally described :

1. Boiling, or as it Ib technically called bucking or dowibW.with milk of lime (lib.
of lime to 14 lbs. of doth, and about as much water as wm ooTer the doth). This
operation conyerts the resinous and fatty matters into Ume-soaps.

2. Washing with water, in the dash*wheel, or other suitable madiins, to remote
the excess of lime and Tarious soluble and mechanical impurities introduced in the
process of manufacture.

3. Souring in hydrochloric add of spedfie ^yitj 1*010 or 2^ Twaddle, to deeonh
pose the lime-soaps and remove the lime. Dilute sulphuric add is sometimei used,
but hydrochloric add is preferable, as chloride of calcium is much more soluble than
the sulphate.

4. Washing again to remove excess of add.

6. Bowking with a solution of soda-ash and resin (170 lbs. soda-ash, and 30 Iha,
resin, to 3500 lbs. of doth, and about the same quantity of water as in the lime-
process). An impei^ect soap is thus produced, which removes the rest of the fttty
matter and dirt

6. Wafthine, and then immersing the doth in the chlorine-bath ; this is called Mr-
inating or enemicking. The solution, which should be quite dear, has a spedfie
gravity of 1002'5 or J® Twaddle.

7. Souring in hydrochloric or sulphu^c add of 2^ Twaddle, to set ^ee the hypo-
chlorous add ; then washing and drying.

The strength of the various liquors must be regolated according to the quality of
the goods to be bleached, and the manner in which the operations are conducted:
the preceding proportions of lime, soda, resin, &c. are given merely as examples. Some-
times carbonate of soda is used in the deansing operations, sometimes a mixture of
soda-ash and quick lime, which of course produces caustic soda. It is often found
advantageous to perform the souring and chlorinating in two successive operations, the
goods being washed between the two. This treatment is found to be less likdy to
injure the fibre than long-continued exposure to the action of the liquid in one open-
tion. In all the operations, it is important to keep the doth oompletdy immened in
the liquid, and never to leave it exposed to the air before washing; because the add
or alkaline liquids, if allowed to become concentrated on it by diyin^ are sure to
destroy the filve.

Bleaching of Linen, •— linen contains a much larger quantity of colouring matter
than cotton, and in bleaching loses nearly a third of its weight, whereas cotton loees
only one-twentieth. This large amount of colouring matter is not natural to die flax,
but is chiefly produced in the operation of steeping or water-retting, by which the
textile fibres surrounding the stem of the plant are separated from the voody
portion.

The colouring matter of steeped flax is insoluble in water, adds, and alkalis, but
becomes soluble in alkalis after exposure to light or to the action of cfalorina Oene-
rally speaking, it is not found advantageous to rely on the action of chlwine alone for the
bleachmg of linen ; the old method of exposure on the grass, — crofting, as it is called,'
being almost always resorted to in addition. Moreover, it is not found possible to get
rid of the colour entirely in one series of operations, several alternate exposures to
oxygen or chlo ine and to alkali being required to render the material perfectly
white.

The following is an outline of the Irish method, as practised in the neighbouAood
of Belfast:

BLEACHING. 60S

1. SUepmg, — After the linen has been Bconred in the ftilling^null, warm water is
poured upon it, and it is left immersed for two or three days, till acid fermentation
sets in. — 2. Boiling with potash-ley, soda-ley, or lime-water. — 3. Washing. — 4. CrofU
ing or exposure on the grass for two or three days. — 2\ 8', 4'. The bowkiDg, washing
and cxofdng are repeated several times, six repetitions sufficing for the £ier linens,
and aa many as twelTO bein^ sometimes required for the coarser. — 5. Souring with
hydrochloric- or sulphuxic>acid of 2^ Twaddle. — 6. Washing, as in 8. — 7. Soaping, that
is, nibbing with solid soap or with very strong so«p-sud& — 8. Boiling in alkaline-ley of
about \ per cent. — 9. Washing, as in 3 and 6. — 10. Crofting for two days.-~-ll. Chlo-
rinating with a solution of hypochlorite of potassium, pre^tred by treating common
bleaching powder with carbonate of potash. The liquor used is very weak. —
12. Washing, as in 3 and 6. — 13. Souring, as in 6, but with somewhat weaker acid. —
14. Washing. — 15. Soaping, as in 7. — 16. Scalding, by immersing the cloth in soap-
suds mixed with a little potash-ley of |° B., and heating the liquid to boiling. —
17. Washing. — 18. Crofting. — 19. Washing and drying.

BUoMng of BUk, — Raw silk contains, besides the true fibre, about 40 per cent, of
foreign matter, viz. albumin, gelatinous substances, wax, fat, resin, ana colouring
matter. These substances are removed by boiling the silk in a strong solution ^
soap, then washing and rinsing. The silk after this treatment, is nearly white, but
to render it quite white, it is sulphured, that is to say, suspended in the moist
state in a large box in which sulphur is burned. About 1 lb. of sulphur is required
for 20 lbs. of silk, and to obtain perfect whiteness, about four sulphurings, of twelve
to sixteen hours each, are required.

Aa the silk loses considerably in weighty when cleansed in the manner above de-
scribed, it is sometimes thought better to subject raw silk to the bleaching process
without previous cleansing. For this purpose, a bath is used composed of 7 pts. nvdro-
chloric acid and 3 pts. nitric acid, sometimes with addition of sulphuric add, the
liquid b^ng diluted with water to 3^ Bm. In this mixture, the skeins of silk are
sospended, and repeatedly moved about for two or 'three hours, then wrung, twice
washed, and afterwards sulphured. Sometimes the bleaching in the acid mixture is
preceded by softening in a soap-bath ; sometimes this softening process is made to
intervene between the acid bath and the sulphuring.

BUaeMng of Wool, — ^Wool is never bleached in the fleece, because its whiteness
would be destroyed in the subsequent operations of spinning and weaving ; the bleach-
ing is, therefore, always performed on the yam or on the woven fabric. A consider-
ame portion of the dirt which adheres to the wool while on the animal, is removed
by the washing which precedes shearing ; this washing also removes the sweat, which
is a kind of soap, chiefly composed of fatty matter and potash. But there still remains
a quantity of free fat, which is generally removed by steeping and agitating it for ten
or fifteen minutes in soap and water, or soda-ley, sometimes in putrid urine diluted
with two or three measures of water, sometimes even in pure water. To prepare the
wool fax spinning, it is then greased with oD, as, without this preparation, it wpuld be
too harsh and very liable to tear. The ^ase thus added must of course be removed
in the subsequent bleaching process. The treatment consists in passing the wool
through a sodarbath, then through a soap-bath, washing in lukewarm water, and
stt^wnsion in the sulphur chamber, this series of operations being repeated several
times, and finally passing the bleached wool through a blue-bath, which is a very weak
solution of soap containing hydrate of alumina and indigo. The sulphuring is some-
times omitted, and the cleansing is effected entirely by ammonia^

Bleaching of materidU for Paper. — The ra^ used for making paper are bleached in
the same maimer as cotton goods. After bemg properly sorted and chopped or torn
in pieces, they are bowked with lime-water, soured, washed in the rag-engine, which
is a combined washing machine and filter, then chlorinated, soured, and washed
again, and finally treat^ with a solution of hyposulphite of sodium to remove the last
traces of chlorine. (See AimCHLOB.)

'* For bleaching old paper : Boil the printed paper for an instant in a solution of
eaostio soda. Steep it soap-suds, and then wasn it ; after which it may be reduced to
pulp. The soap may be omitted without much inconvenience. — ^For old written paper
to be worked up again : Steep it in water acidulated with sulphuric acid, and then
wash it well before it is taken to the mill If the water be heated, it will be more
effectnaL — To bleach printed paper without destroying its texture : Steep the leaves
in a caustic solution of soda, eitner hot or cold, and then in a solution of soap.
Ananse them alternately between cloths, as paper-makers do thin sheets of paper
when delivered from the form, and subject them to the press. If one operation do not
render them sufficiently white, it may be repeated as often as necessary. — To bleach
old written paper without destroying its texture : Steep the paper in water acidulated
with sulphuric acid, either hot or cold, and then in a solution of oxygenated muriatic

604 BLOOD.

acid ; after which immene it in water, so that some of the acid maj remain behind.
The paper, when pressed and dried, is fit for use." Ure.

The bkachinff of straw is efi^ted by steeping it in hot water, heatinj^ it repeatedly
during several days, and immersing it in weak solution of chloride of luie or of aoda,
alternately with weak alkaline le^s.

BUaehing of Horse-htur.-^White horse-hair requires fiuther bleaching to adapt it to
many purposes. The process consists in washing it in sodarsolutions, not too strong
and at the heat of the nand, then hanging it np in the snlphur-ehamber, and repeating
these processes several timesL

[For further details, see Ur^s JHoHtmary of ArtB, Manufactvrei, and Mmet, i 818,
also Mtapratfs Chemistry, I 299.]

B&aiLCSnrCI PO'WBBB. Chloride of lAme, Oxymuriate oflAme, See Htfo-
CHLORiTBS, under Chlobikb.

XTB. Basic Antimonate of Lead (p. 326).

Native Sitlphidb of 2inra (See 2iiNC.)

Probably the same as AsraicAinTB (i. 429).

B&OOS>a The blood of the higher animals forms a rather viscous opaque liquid,
heavier than water, and of more or less intense red colour, arterial blood being always
lighter than venous. It is transparent in veiy thin strata. The specific gravity of
normal human blood averages about 1*065, but under certain circumstanera varies
between 1*045 and 1*075; it is slightly less in women than in men, and still less in
children. The specific gravity of arterial blood is rather lees than that of venous.
The blood of most domestic animals differs but little in specific gravity frran that of
man (specific gravity of bullock's blood « 1*060; of sheep's •■ between 1*050 and
1*058). The blood has always an alkaline reaction. When warm it has a^ pecoliar
odour, generally more powerful in the male than in the female.

From two to five minutes after the blood has left the circulation, it begins to eo^v-
late, a film gradually extending from the surface and circumference, so that the whole
becomes gektinous in the course of from seven to fourteen minute& The coogvlmai
{Jibrin and blood-corpuscules) then gradually contracts and separates firom the watexy
portion of the blood (serum) ; and in from twelve to forty hours, the blood is completely
resolved into serum and thick red clots, which swim beneath iU The blood of men
coagulates more slowly, but yields a denser coagulum than that of women ; in the
embryo it coagulates imperiectlv. Arterial blood coagulates more n^idlj than
venous. The presence of air and a rise of temperature promote coagulation; cold
retards it.

The constituents of blood are partly in solution and partlv suspended (blood-cor-
puscules). Swammerdam, in 1664, first observed corpuscules in the blood of the frog ;
he described them as ovaL Leeuwenhoek (PhiL Trans. 1664, p. 23) found that human
blood consisted of round bodies swimming in an opaline liquid, and that tiie colouring
matter of the blood of mammalia, fish, and frogs was contained in these corpnscnko,
which were round in men, oxen, sheep, and rabbits, but oval in birds, frogs and fish.
Later observers discovered that all blood-corpuscules are flattened. The coloured
corpuscules consist of a colourless enevelope, the contents of which are red, or by trans-
mitted light vellow, and each is slightly depressed and concave in the centre. In
general they do not possess any nucleus, and only a few of them exhibit something
approaching to one. The size of the red corpuscules varies considerably in difTemit
animals, the smallest being found in the blood of the Moschusjatfanicus, and having a
diameter of 0*00208 mm. (Gulliver), and the largest in that of ti^e OrwiobroHehus
japonicus (0*05623 mm. broad, and 0*0333 mm. long, Y. d. Hoeven). The human
corpuscules have a diameter of 0*00752 mm., those of the carnivora between ^
and tIj mm. and their thickness is generally ^ or } of their diameter. The blooS
corpuscules of embryos are larger than those of the arown up j^nimala of th

corpuscules of embryos are larger than those of the grown up j^nimala of the
species. Milne-Edwards asserts that the size of the corpuscules is closely connected
with the size of the omins of respiration. To prevent their «briiiting up during
measurement; C. Schmidt moistens a glass plate with an exceedingly thin layer of the
blood to be examined, so that it dries up immediately. The corpuscules thus adhera
by their flat sides to the glass, and remain of this same size when the semm has dried
up. The blood of different animals may fr^uently be distinguished under the micro-
scope by the size of the corpuscules.

According to Schmidt^ the specific ^avity of the blood-corpuscules of a healthy man
varies between 1*0885 and 1*0889 ; m cholera it sometimes increases to 1'1025 or
1 '1027. The red corpuscules sink in the serum ; they are generally equally coloured ;
a few, however, are sometimes darker, sometimes lighter than normal corpuscnlea. The
difference in colour is dependent upon the absolute amount of hiematin in the cor-

BLOOD. 605

piueiileB, thepToportioii of whicli relatiTe to the serum influences the general colour of
the hlood. The form of the oorpuscules also affects the colour of the blood, for if these
be swollen bj addition of water, they become more spherical, and the blood appears of
a darker colour. Mulder supposes that the bright colour of arterial blood is due to the
greater thicluieea of the enyeloping membrane of the corpuscules. Nasse states that
by the action of carbonic add gas, the cells become darker in colour and turbid in the
centre. All substances such as caustic alkalis, and sereral organic acids, which burst
the corpiuculeB, or otherwise liberate their contents, turn the blood dark brownish-red,
while thoae, such as nitrate and iodide of potassium, phosphate and carbonate of
iHMliufF*, &C. which contract and so thicken the external mem orane, render the blood
cf a lighter colour.

The ayersge proportion by weight of moist blood oorpuscules in a healthy man »
61'2 % (47*2 — ^'2 %). According to Vierordt, 1 cubic millimetre of blooa contains
6,066,000 ooipuscules. The amount of dry corpuiMmles in the blood of man is Tariously
arm ^12-9% (Pr^TOst and Dumas), 14-1 (18*1— 15'2%) (Becquerel and
Sodier), 11'66 (Nasse). The blood of women contains fewer coipuscules than that
of men, amounting to 36'924 % moist oorpuscules (C. Schmidt), and 12*72 dry (11'3 —
13*76 %) (Becquerel and Bo dier). The blood of middle-aged men and animals con-
tains more oorpuscules than that of older or younger indiTiduals of the same species.
The amount of oonuscules also Taries in the blood of different animals, that of birds
eontaininff most^ tnat of the camiyorous and herbiyorous mammalia less, and that of
oold-Uooded animals by fiir the least, as will be seen from the following table, in whidi
the pereaUoffes of dry corpuscules are giyen :

CUeken. FlReon. Ox. Sheep.

1671 (Pr. and Du.) 16-67 (Pr. and Du.) 9*70 (AndraL) 9*36 (Pr. and Du.)

14*46 (Kasee.) 1218 (Nasse.) 9*80 (AndraL)

16-00 (Poggiale.) 14*80 (Poggiale.) 12*30 (Poggiale.) 9*24 (Nasse.)

10*20 (Poggiale.)

I>af. Frog. Bel. Carp^

12-38 (P)-. and Du.) 6*90 (Pr. and Du.) 600 (Pr. and Du.) 8*23 (Berthold.)

12*38 (Nasse.) 4*68 (Berthold.)
12*60 (Poggiale.)

The proportion of corpuscules in the blood of different yessels also yaries. In general,
arterial blood contains fewer corpuscules than Venous, the blood of the portol yein
fewer than that of the ju^ar yein, while that of the hepatic yein contains far more
than that of the portal yein, jugular yeins, yena cava or splenic vein (Lehmann).
Lehmann found 66*662 % moist corpuscules in the arterial blood of a horse, 48*996 in
jugular blood, 66*688 in that of the yena caya.

Insufficient nourishment and long abstinence, as well as repeated blood-letting,
diminish the quantity of blood-corpuscules ; the amount increases if large quantities
of £it are taken in the food. It is also influenced by disease, a constant increase beins
observed in plethora, in the earlier stages of heart-disease, in spinal irritation, and
in cholera. Decrease occurs in all cases where the consumption of hlood is greater than
the snppb[, e, g, diarrhosa, intermittent fever, affections of the brain, and chlorosis
(8*613 % Becquerel and Bodier). The percentage of water in tiie corpuscules bears
a pretty constant relation to that of the serum, so that when the amount of water
decreases in the senmi, it also decreases in the corpuscules.

Colourleu blood-eorpuscuiea are always present in blood, but at least in the case of the
warm-blooded animals, in much smaller quantity than the coloured corpuscules. They
are generally almost spherical, but sometimes lenticular ; they have a granulated enve-
lope, and generally a round nudeus, which is more rarely oval or ki<uiey-8haped, and
strongily refracts light : sometimes it is formed of several small nuclei grouped together.
They are identical with the lymph- and chyle-corpuscules, and do not differ much
from, the pus- and mucus-corpuscules. They are unelastic, and their envelope is so
viscous thAt the corouscules readily adhere to one another. They circulate less rapidly
in the blood than the coloured corpuscules, and contain an albuminous liquid holding
very minute granules in suspension. Dilute acetic acid gradually dissolves the ex-
ternal membnme. In human blood they measure 0*01128 mm. m diameter. They
are specifically lighter than the red corpuscules, since they contain more fat and no
hiematin. In healthy blood they bear to the red corpuscules the ratio of 1 : 1*373
(Donders and Moleschott); the number increases during digestion and diminishes
by fasting, the increase commencing thirty minutes after partaking of food, and lasting
two hours. They increase in certain diseases, frequency in pneumonia and tuber-
culosis. In leuchsmia this increase often amounts to one-fourth of the blood-corpus-
cules. The splenic blood contains large quantities of colourless corpuscles, about one-
fiovrth or one-third of the total amount of corpuscules.

606 BLOOD.

6^a«es,— 'Ab early as 1674, free giuMS were suppooed to be dLnolTed in blood, lad
the question was finally set at rest by the experiments of Ma^va. The o^cdioii
raised by Lagrange to Lavoisier's theory, that if combustion took pLsoe only in the
lungs, the other parts of the body would have a lower temperatore, led him to suppose
that the blood merely dissolved the inhaled oxygen, and afterwards distribiitfid it
throughout the system. Fourcroy was, however, of opinion that combustion took
place principally in the lungs, and that onl^ a part of the oxygen was diasolTed by
the blood. H. Davy r<^marked that blood in contact with oxygen absorbs a oertaiD
quantity of the gas, giving off carbonic add in exchange, and Naase obserred diat
blood in an atmosphere of hydrogen evolved carbonic acid. It has also been remarked
that in an atmosphere of nitrogen, arterial blood evolves oxygen, but not Tenooi
blood. Mayow, Vogel, and others, obtained carbonic acid from the blood by means
of the air-pump. Magnus also used the air-pump in his experiments, but edUected
the gas under mercury, and found the gases in arterial blood to consist of 14*6% K,
62-3% C0«, and 232% O, in twium*, 131% N, 71*6% CO«. and 15-8% 0. L. Mejer
undertook a series of experiments on the gases of blood, under the guidance of BuBfen.
The blood was diluted with ten times its bulk of water, and the gaaes were eoUeeted hr
boiling the liquid in vacuo at a very gentle heat : the free gases were thus obtained.
A few crystals of tartaric add were &en added, and the blood again boiled, whereby
the combined gas was liberated. The following table contains the quantities of gasee
(at Qo and 0'76am.) in 100 vols, of blood.

Free Gas.

Free CO«. ^^^^^

ToUl.
CO*.

Tndl
Ga.

Art. Caret, (Bog) (1)

20*88

12-43

2-83

6-62 28-61

34-23

49-49

>t •* »» (2)

25-60

14-29

604

617 28-68

34-76

64-08

. Blood at 0^ and 1 met absorbs 1*161 vol. carbonic add, besides 0-481, independently
of the pressure (combined CO*}. Defibrinated calf s blood, free from air, abiorfae
under different pressures the same amount of oxygen (0'3% voL at 0^ and 0-760 m.)
Serum absorbs a much smaller proportion of gases than defibrinated blood. The red
colouring matter absorbs a considerable quantitv of oxygen, and evolves a Utile ear-
home acid. G-. Harley found that blood, or defibrinated blood, absorbed oxygen vhen
shaken up with air, and evolved carbonic add, but in less quantity than ooirespooded
to the oxygen absorbed

It is difficult to explain satisfactorily why blood should .absorb so mach more
carbonic acid than pure water at the same temperature ; it is periiaps partly owing to
the neutral alkaline carbonate in blood forming add carbonate, but this does not acooont
for all the carbonic acid absorbed. Liebi^ has remarked that water containing 1 %
phosphate of sodium absorbs twice as much carbonic add as pure water, while wat^
containing 16 % chloride of sodium only takes up half as much. It is also wapposed
that oxygen, of which blood absorbs from 10 to 13 % of its vol., and water only
0*926 %, combines in a loose way with blood, like nitric oxide wit^ fenoos snlphate,
since the voL of gas absorbed does not increase proportionally with the pRaenie
(Lie big). It has also been shown that part of the oxygen thus taken np by blood
cannot again be separated. ^See Gasbs, Absobptiow of.)

Constituents of the coloured blood-eorpuscules, — ^Berzelius has diown that
the coloured corpuscules contain an albuminous substance (globulin) differing froa
albumin. Schmidt separated the corpuscnles by means of sulphate of sodinm, and
found them to contain 87*69 globulin and 12-31 % hsematin. Mulder considen tbe
outer membrane of the corpuscules to be binoxide of protein, a hypothetical sabstance ;
others have taken it for fibrin. Its composition does not appear to be fixed, since the
membrane of different corpuscules is variously affected by tne same reagents.

Blood-crystals ; HamcUocrystallin.^-0. Funke first con^letely investigated the at-
ture of the cirstalline substance of the red corpusdes. Funke and Kunde obtain the
crystals by adding to a drop of blood, water, ether, alcohol, or chloroform, allowing
the mixtiue to dry slightly on a glass plate, and then covering the whole with a
glass cover. Lehmann passes a slow stream of oxygen or nitrous oxide for iboat
fifte^ minutes into a mixture of blood and water, and afterwards carbonic acid, till
the liquid turns bright red and becomes turbid, whereupon it crystallises. When a
considerable quantity of blood is to be operated upon, it is best to leave it to coagulate,
press the clot to remove the serum, cut it in pieces, and wash it on a linen filter with
water till the filtered liquid amounts to about IJ times or twice the volume of the
water used The liquid is then to be poured into a glass cylinder, oxygen gas passed
into it for about half an hour, and then carbonic add for ten or fifteen minutes, after
which it is left at rest. If no crystals form after about two hours, the b'quid must be
mixed with | of its volume of alcohol (Lehmann.) Light promotes the ciyBtallieatioii,
which is not caused by evaporation of water, since blood will crystallise as readily

65-41

65-24

56-18

708

7-12

7-14

17-27

17-31

16-40

0-25

0-21

0-26

19-99

26-12

2003

BLOOD. 607

with twice its Tolume of water as with only half that quantity. It cannot b<> doubted
that both oxygen and carbonic acid, by their chemical action on. the contents of the
cotposeolea, are inatmmental in the formation of the crystala. The form of the
oyatals yariea in the blood of different animala; those obtained from the blood of
men, naoet mammalia, and fish, form prisms ; from the rat, mouse, and guinea-pig,
tetrahedrons ; from the squirrel, hexagonal tablets ; and from the German marmot-,
likombohedrons (of about 120^), or yezy thin hexagonal plates.* The tetrahe-
dral crystals dissolve with peach-blossom-colour in 600 pts. of water, the pris-
matic with dark-red colour in 94 ^ts. water. Nitric acid turns the eiystals almost
black, but dissolyes them on warming, and acquires a yellow colour. Their solution
is decolorised by chlorine, which prcipitates white flakes ; it is turned dark brownish-
red by carbonic oxide, and renaered turbid and brownish-red by nitrogen. The
same sised crystals from the same blood often differ in intensity of colour and have
probably not always the same composition. l|hey seem to be an albuminous substance.
The solution of the tetrahedral crystals coagulates at about 63^ 0., that of the pris-
matic crystals between 64^ and 66^. The crystals exhibit, according to Lehmann's
axuilysis, the percentage composition of the albuminoids :

Carbon 65-41

Hydrogen ....

Nitrogen ....

Sulphur ....

. Oxygen ....

100-00 lOC'OO 100-00

Bmmatin is peculiar to the blood-corpuscules of rertebrate animals, and in some way
combined with the remaining albuminous contents of the oorpuscules. It is obtained
as an amorphous blackish-brown substance, by treating the corpuscules with sulphate
of sodium, extracting the residue with alcohol containing sulphuric acid, and treating
with ammonia, water, alcohol, and ether. It is insoluble in water, alcohol, ether,
acetic ether, and oils, both fat and volatile, but readily soluble in alcohol containing
sulphuric or hydrochloric acid. It is not dissolved by concentrated mineral acids.
Aqueous or alcoholic solutions of alkalis or their carbonates dissolve hsematin in all
propcntions. A sulphuric acid solution of hsematin which has been turned red by
admtion of alkaH, exhibits dichioism, appearing green by transmitted and red by
reflected light If hsematin be allowed to stand m contact with pure concentrated sul-
phuric aei4 it may be obtained perfectly free from iron, without suffering any perceptible
change in its properties. Benselius found in the dry blood corpuscules of men and
oxen 0*38 % metallic iron, and since Mulder has found 6-64 % iron in hsematin, the
corpuscules would contain 6*72 % hsematin, and the blood 0*782 %. Becquerel and
Rodier found in blood, 0*0666% iron, and 14*11% corpuscules, which would give
6-02 pCs. hnmatin to every 100 pts. corpuscules. In disease, the proportion of hsematin
to the whole blood probably varies with the corpuscules. It is not known whether
there is a fixed relation between hsematin and the albuminoid of the corpuscules.
Mulder assisus to it the formula C^^H^'O*. The arterial blood of the horse contains
rather less hjematin than that of the outer jugular vein ; the corpuscules of the liver-
blood eontain far less than those of the vena porta. The proportion of iron to dry
corpuscules in arterial blood «■ 1 : 394 ; in that of the Jugular vein 1 : 390 ; of the
vena porta 1 : 312 ; of the liver 1 : 600 (Lehmann.) Poggiale found 0*126 % ferric
oxide inhuman blood, in thatof the ox 0*126, calf 0-111, dog 0-146, sheep 0*106, diicken
0*076.

A substance called A«ma<oiifn has been observed in blood extravasated in the tissues
of living animals. It is sometimes amorphous, in grains and little globules ; some-
times in crystals beloneing to the monodinic system. It is transparent, strongly
rdracting^ yellowish-red or ruby-red, insoluble in water, alcohol, ether, acetic acid,
and dilute mineral acids. It generally turns ardent red on addition of potash,
gradually disintegrates, and snlits up into red granules, which gradually dissolve.
The hsematoidin is not reprecipitated by neutralising the alkali By the action of con-
centrated sulphuric acid, the sharp contour of the crystals vanishes, and the colour of
the round concretions first turns brownish-red, then green, blue, and rose, and finally
dirty yellow. In the liquid, iron may sometimes be detected, but not always. Ac-
CQitfing to Bobin, its formuk is C*«H««NK>*.

The nature of the nudei which sometimes occur in the corpuscules is unknown.

A oonaideraUe quantitv of the fat of blood occurs in the corpuscules, nearlv the
whole of the so-called phosphorised fats being contained therein. Lehmann found
2*214 and 2*284% fat in the dry corpuscules from bullock's blood. The ethereal

* Fifnrf* of these crrtMU ore given in Piinlce't Atlas nf rhyitlolofficiil Chemistry (Leipzig, 18A8, also
IKiMiihcd by tht Caf radish Society) ; aiid in the Ilaudwdrterbuch der Chemie, 2t« AuA. ii. [2] ISG.

608 BLOOD.

extract of these cor^nscnlcs yielded 22 % add ash, conmflt.ing of acid phosphate of
sodinm, from which it is proDable that phosphoglyceric add is contained in the cor-
poscoles. The corpnscnles in the blood of oifferent Tessela do not contain the snne
amount of fat. In the moist corpuscules of the carotid artery of the horse, vere foosd
0'608 % fat ; in the external jnguJar yein 0*652 % ; in the Tena porta 0752 ; in lira^
blood 0*684. Dry oorpnscules separated from artenal blood by sulphate of sodium cob*
tained 1*842 % fat ; from venous blood 8*595 %.

The solid constituents of the corpuscules contain rather less than 6% ettmeihe
matter, the nature of which is unknown. They also contain a fr«e or looedy oom>
bined nitrogenised organic add.

Moist corpuscules contain on the average 68*8 % toater (Lehmann). Taking into
account the amount of serum endosed in the coagulum, the corpuscules contain a mudi
smaller proportion of soluble salts than the serum. It will be seen from the analyses bjr
Schmidt (p. 611), which are the most tmstworthy, that the corpuscules contain pxin-
ci^ally phosphates and potassium salts, and, in smaller quantity, chlorine, sulphune
acid, soda, and earths, while the serum contains proportionally less chloride of potassium
and phosphate of sodium, and more chloride of sodium, sulphuric add and earths. In
man the moist corpuscules contain 0*7282 % salts. The blood of those onimiJa which
contained most corpuscules also contains most alkaline phosphates (Nasse). The
corpuscules contain less earthy phosphates than the serum. Iron belongs ahnoe>t
exclusively to the red corpuscules (hsematin). Clear serum contains no iron. (Nasse
and Schmidt).

Fibrin. — As already stated, the spontaneous coagulation of the blood is caosed
by the separation of the fibrin, which at the same time endoses all the corposcoles
and a portion of the serum. As soon as the blood has left the body, a film gatiiers
on the surface of the liquid, extending in the form of a star, from the sides of the
vessd towards the centre ; a dot, adhering to the sides of the vessel, then forms.
Often, within two minutes after the blood has been collected, it becomes viscid
and gelatinous, and after a time a few drops of li(|uid, gradually increasing in quantity,
separate from the jelly, till the coagulum swims in the serum. According to circum-
stances the coagulum is more or less contracted, consistent, viscous, and elastic. If
the coagulation be observed under the microscope, exceedingly fine straisht threads
wiU be seen to shoot out from various points between the corpuscules, and, gradually
increasing in length, to cross one another, so that finally the whole foxms a network
endosing the corpuscules. If the amount of fibrin is small in comparison to the cor-
puscules, the coagulum is comparatively light; denser, on the contrary, when the amount
of fibrin is larse. A large quantity of water diminishes the consiFtence of the coagulum.
Various salts have the property of retarding or entirely preventing the coagulation of
blood. The alkaUs and their carbonates and acetates nave this effect, and rather
strong solutions of nitrate of potassium, nitrate of caldum, and chloride of am-
monium in a less degree. Most dilute adds also maintain the fluidity of blood, though
they render it rather more viscous. The venous blood of a healthy man contains
between 0-203 and 0*263% fibrin (Scherer), 0*220 (aversge, Becquerel and
Bodier), 0*250 % (Denis). Arterial blood contains more fibrin than venous. (See
FiBBm.)

Constituents of the Serum. — The average specific gravity of serum « 1*028; it is
less variable than the spedfic gravity of blood. The amount of water in the serum
varies between 88 and 95*6%, averaging 90*5 or 90*6% (Nasse). Women's blood
contains more water tJian that of men« According to C. Schmidt, the serum of man
contains 90*884% water, and that of woman 91*715; and, according to Nasse, the
serum of pregnant women is more aqueous than of others. At an advanced age, the
amount of water increases considerably. The following table contains the percentages
of water in the serum of different animals : —

Ox. Sheep. Dog. Chtcken.

90*8 (Nasse.) 91*5 (Ihu and Pr.) 92*6 (Du. and Pr,) 92-5 (Du. and Pr.)

91*6 (Berthold.) 91*8 (Nasse.) 91*2 (Nasse.) 93*1 (Nasse.)

Pigeon. Frog. Ee].

94*6 (Du. and Pr.) 95*0 (Du. and Pr.) 90*0 (Du- and Pr.)

According to most observations, the serum of arterial blood contains more water than
that of venous blood. Simon found in the arterial blood of two horses, 2*734% more
water than in the venous blood, and, according to Nasse, arterial blood contains 5*0%
more water than venous. As a general rule, the amounts of water in the serum and
of corpuscules in the blood are inversdy proportionaL An absolute diminution of
water has only been remarked in cholera.

Albumin is the most abundant of the constituents of the scrum, amounting to be-
tween 6*3 and 7*1% of normd blood, and between 7*9 and 9*8 % of normal serum.
Neutral albuminate of sodium, which becomes turbid on addition of water, oeeurs not

BLOOD. 609

cmlj in morbid blood, but tdao in the blood of the spleen. The sernm of the blood of
the Tena porta gives less turbidity, and that of the liyer-blood more, than of the

3>leen. when the alkaline sernm of liyer-blood is neutralised with acetic acid, the
bumin does not coagulate on boiling till after sereral hours, while that of the yena
porta and other yeins, as well as of the arteries, speedily coagulates on addition of
acetic acid and boiliug. Hoppe is of opinion that the slbtmLin in serum is not dis-
solyed, but merely suspended in a state of fine diyision. According to Becquerel and
Bodier, normal man's blood contains 6*94 % (6*2—7 '8 %) albumin, and that of women
7*06 (6-6 — 7*65) %. The blood of pregnant women was found to contain from the 2nd
to the 7th month, 7*0—6*8 % albumin, and in the last two months, 6*8—6*4 %. (J.
Kegnault). Arterial blood contains less albumin than yenous, and the amount in
liver-blood mcreases considerably during digestion ; it decreases in scurvy, puerperal
fever, and Bright's disease, and increases in intermittent fever, cholera, &c In typhus,
it amounted to 6*5 %, and in Bright's disease to only 4*93 %.

Fats, — But few free fats are found in serum ; they occur chiefly saponified. Che-
vreul and Babington first discovered the presence of normal fats in blood. Oleic, mar-
garic, and stearic acids, both free and saponified, have been detected in the serum of
bullock's blood, and cholesterin is constantly present. Boudet describes, as a fat peculiar
to the serum, a substance extracted from its residue by hot alcohol (serolin), which
6robley considers as a mixture of ol^, maigarin, cholesterin, and cerebrin. Aocordine
to Chevreul, phospholei'c acid (cerebrin) is contained in the fibrin and serum. Compared
with the corpuscules, that of the serum is more ciystalline, less viscous, and colour-
less. Normal serum contains 0^2% fat) and its solid residue 2 22% (Simon, Nasse,
Becauerel). The amount of fat in the blood is not increased by food rich in fat, nor
is it aiminished by nourishment free from fat. During digestion, the amount of fat
in chyle and in the blood of the vena porta, has been found to increase considerably, so
as occasionally to render the serum turbid. According to Becquerel and Bodier, the
blood of women contains 0*57 p. m. fat and soaps, and l^at of men 0*69 p. m. Serum of
arterial blood contains less fat than that of venous, and the vena porta blood is richer
than the jugular. Becquerel and Bodier have found that, almost at the commencement
of eveiy acute disease, ^e proportion of fat (especially cholesterin), in blood increases, as
well as in some chronic diseases, particularly in liver diseases, Bright's disease, tuber-
eulosift, and cholera.

Little is known of the extractive matter of the serum ; it varies between 0*25 and
0*42 %. Lehmann found more in the arterial than in the venous matter of the horse.

Sugar (grape-sugar), is a normal constituent of blood. The blood of the vena porta
contains but traces, while that of the liver contains larger quantities. In normal
bollock's blood, it varies between 0*00069 and 0*00074 % (Lehmann). The blood
of a dog contained 0*0015, and of a cat 0*0021 %. In the blood of diabetic patients
Lehmann never detected more than 0*047 % sugar. The amount varies with the nature
of the food. Urea occurs in healthy blood to the amount of 0*0142 — 0*0177 %. It
has been detected by evaporating large quantities of serum and adding nitric or oxalic
acid to the residue. The quantity increases considerably in Bright's disease (1*5 %
in serum. Bright and Babington), and in cholera (0*14 %). Uric acid has been
found in the blood of healthy as well as of diseased persons. Garrod found between
0*0012 and 0*0055 in the serum in a case of Bright's disease. Creatine, creatinine, hip-
wiric aeidt and kypaxanthine, have also been detected. According to Musing, alcohol
turn been detected in the blood of men who had died from drinking brandy. Ha-
te<uoci states that goat's blood warmed' with sulphuric acid evolves caproio acid,
Scherer has detected lactic acid in a case of puerperal fever. Fourcroy and Vauquelin
and others state that they have found bile-constituents in healthy blood ; they some-
times occur in morbid blood. Leucine and tyrosine occur in small quantities in liver
and portal blood, in diseases of the liver. Little is known of the colourina matters
proper to ^e serum. An intense yellow coloration of the serum is often due either
to bile-pigment) which may be detected not only in icterus, but also in pneumonia.
Black, soucely yellow, brown, or red granules of pigment are said to have been de-
tected in the heart, large vessels, liver, and spleen, after intermittent fever. Blood con-
tains neutral carbonate of sodium (0*1628 % in bullock's blood, Lehmann), probably
as acid carbonate (Lehmann, Liebig). Meyer concludes from his experiments that
it is not present as acid carbonat). Blood seldom contains sulphates, and never more
than toufes; it contains silicic Osid (Mi lion), and according to G. Wilson, traces of
Jluorine, Normal blood never contains ammoniay but that alkali is sometimes found in
disease (cholera, &c)

Salts, — The serum of man's blood contains 0*88 % (av.) salts, that of women
0*81 %. Lehmann gives the following composition of the ash according to the best
analyses: 61*087 % chloride of sodium, 4*085 chloride of potassium, 28*880 carbonate

Vol. L BR

610 BLOOD.

of sodinm, 8'105 phosphate of sodium (Na'HFO*), 2*784 sulphate of potaaaium. The
serum of grown-up animals contains more salts than that of the young ; the scram of
the calf, howeyer, contains 1*12 % salts, while that of the cow contains 0*99, and of the
ox 0*87 % (Nass e and Poggi ale). The blood of cats, goats, and sheep, contains the
most salts; of birds, men, and pigs, less; and of dogs and rabbits the least Artezial blood
serum is somewhat richer in salts than Tenons, and the serum of portal blood contaiai
considerably more than that of the jugular vein. The kind of nourishment has great
influence on the amount of salts, and of their several constituents. Plouriez and Fog-
giale found that in the blood of animalH to whose food common salt had beea added
for several months,* the percentage of salt rose from 0*44 to 0*64, an increase due chiefly
to chloride of sodium. The amount of salts is also greatly influenced by disease, being
particularly small in violent inflammations, and mcreasing in typhus» &c. Weber
foimd 1*19 % silica in the ash of bullock's blood.

The amount of salts, exclusive of iron, in man's blood » 0*728 %, woman 0*896,
dog 0*713 %. Some chemists think they have detected manganese in blood, but its
presence la doubtful Millon found copper in the blood of soldiers whose food had
been prepared in copper vessels, and others have detected traces in the blood of men
and beasts. It is said always to occur in the ash of the blood of Umulus C^febfi,
Millon also detected lead in blood.

Analysis of Blood. — The amount of water in blood is easily estimated by evapo-
rating a weighed quantity, and drying the residue at 120^'^130^ C.

To determine the jihrin^ the blood, as it runs from a vein, is received in a tared
vessel, and stirred for 6 to 10 minutes with a glass rod, the weight of which is in-
cluded in the tare, till the fibrin is completely separated. The blood, together with
the separated fibrin, is then weighed, strained through linen, and the fibrin whidi
remains thereon is placed for some time in water, then dried, well boiled with alcohol
and ether, to £ree it from fat, and weighed after drying at 120^ C. (Becquerel and
Bodier). — Another method of estimation is to leave a weighed quantity of blood to
coagulate at rest, tie up the dot in a fine linen bag, after it has contracted as much
as possible, kneaid it first by itself, afterwards with water, and treat the residue as
above. (Scherer.)

Eeiimation of Albumin and other Matters coagvlabU by Heat, — A weighed quan-
tity of the blood, slightly acidulated with acetic acid, is added by drops to TxnliBe
water, the liquid is poured through a weighed filter, and the coagulum oolleeted
thereon ; it is then washed on the filter with boiling water, and dried, first at a gentle
heat, afterwards at 120° to 130° G. The residue may be freed from &t by treatment
with boiling ether. If the blood had not been previously freed from fibrin, the weight
of that substance, determined as above, must be deducted from the total weight of the
coagulum.

Estimation of the Extractive Matter. — The filtrate obtained in the last determination
is evaporated on the water-bath in a tared platinum basin, the residue dried at 120° C^
weighed, and burnt in a muffle at as low a heat as po8sibl& The weight of the ash,
deducted from that of the total dried residue, gives approximately the amount of ex-
tractive matter.

Estimation of Fat — A quantity of blood (which need not be weighed) is dried at
100° C, the residue is pulverised and dried at 120°, and a weighed portion thereof is
treated with ether in a flask : the ether is passed through a small filter into a tared
platinum capsule; and the treatment of the residue with ether is ropeated several timeeL
The collected ethereal solution is carefully evaporated, and the residue dried at 100° C.
As the weight of the solid constituents of the blood has been previously determined,
the quantity of blood from which this amount of fat has been obtained may be cal-
culated from that of the residue which was subjected to treatment with ether.

Estimation of Mineral Constituents. — A weighed quantity of the blood is dried,
mixed with ignited carbonate of sodium, then dried and incinerated in the muffle at
the lowest possible temperature. (See Ash of Oboanio Bodies, p. 418.)

Separate Estimation of the Serum and Coagulum, with their Constituents. — The
fr«sh blood is collected in a tared cylindrical vessel, having a ground edge, and not
too shallow ; it is covered with a glass plate and left to stand till the coagulation is
complete, after which the edge of the dot is detached from the side of the vessel by
means of a needle. The blood is then weighed, and after the clot has contracted as
much as possible, the serum is poured ofi^, and the quantity of albumin, &c., contained
in it is determined as above described. The clot and the inner surface of the vessel
are then freed from serum as completely as possible by wiping with bibulous vsuper,
and the clot is weighed on the vessel. This weighty deducted from the total weight of
tiic blood, gives the proportion of serum.

The clot contains the blood-corpuscules, the fibrin, and a certain quantity of sernm ;
the amount of water contained in it maybe determined by drying i^ 120° to 130° C,

BLOOD.

611

Vnt there ia no known method of directlj estimating the amount of the blood-cor-
poscules. Prevoet and Dumas estimated it approximately on the assumption that the
water contained in the dot is all due to adhering serum, and accordingly deducting
from the weight of the dried dot an amount of serum-constituents corresponding to the
quantity of water in the dot» together with the amount of fibrin separately determined.
As, howerer, the blood-ooipuscules themselyee contain water, this method necessarily
makes the quantity of diy oorpuscules too smalL

Acoordinff to C. Schmidt, the clot contains a quantity of serum amounting to | of its
Tolumei and the weight of the moist blood-Ksells is four times asgreat as that of the
dry dot, as determined by the method of Prevost and Dumas. Hence, when the con-
stituents of the serum and coagulum have been determined as aboTe, and from the
weight of the coagulum, a deduction is made of the quantity of serum-constituents
oorresponding to } of the weight of the moist coagulum, the composition of the cor-
poscuies may be calculated.

The separation of hiematin from globulin cannot be effected ; but if the quantity of
iron in the dry coagulum be determined, the amount of blood-pigment may be cal-
^^mt^ on the supposition that this pigment contains 6*64 per cent of iron. (Strecker,
Handw. d. Chem. iL [3] 116).

1000 pU. Blood-oorpusclM contain :

Water

Solid constituents :

Density

Hiematin • .

Globulin and membrane of cor-

puscules • .
Fat. . . .
Extractiye matter .
Mineral matter (without iron)

Chlorine

Sulphuric acid

Phosphoric acid .

Potassium • •

Sodium • .

Oxygen

Phosphate of caldum

Phosphate of magnesium

68800
31200

1-0886

1676

282-22
2-31
2-60
812
1-686
0066
1134
3-828
1062
0-667
0-114
0073

1000 pu. Serum contain s
Water
Solid constituents

Density

Fibrin • .

Albumin . •
Fat . .
Extractive matter
Mineral matter .

Chlorine

Sulphuric add

Phosphoric acid

Potassium

Sodium .

Oxygen .

Phosphate of calcium

Phosphate of magnesium

902*90
9710

1028

4-06

78*84
1-72
3-94
8-66
3-644
0116
0*191
3-323
3-341
0-403
0-311
0*222

Mean Com^poHHon of Male and FemaU Blood (Becquerel and Rodier).

Male

1060*00

1028-00

Density of defibrinated blood

Density of serum . • • . .

Water 77900

Fibrin 220

Fatty matters 1*60

SeroUn 0*02

Phosphorised frtt 0*49

Cholesterin • 0-09

Seponifledfat 1*00

Albumin 69*40

Blood-corpuscules 141-10

Extractiye matters and salts • . . 6*80

Chloride of sodium 8-10

Other soluble salts 2-60

Earthy phosphates 0*33

Iron 0*67

Female.
1017-60
1027*40

791*10
2-20
1-62
002
0-46
0*09
1-04
70-60

127*20
7*40
3-90
2*90
0-36
0-64

1000 pts. Blood contain (Schmidt) :

Ifolat corpaieulet

Senim

Han.

Woman.

Dog.

5ia>09
406-98

896*24
60876

648-S6
456*44

BB 2

612

BLOWPIPE.

Salts in 1000 pts. :

Cor-
puscles.

Serum.

Cor-
puscles.

Serun.

Cor-
puscles.

Scran.

Sulphate of potassium ,
Chloride of potatsium
Chloride of sodium .
Phosphate of potassium .
Phosphate of sodium
PotMsa ....
S 'da . . . . <
Phosphate of calcium
Phosphate of magnesium

•

» <

> <
* *

0-132
3*679

2-343
0-633

O'ill
0094
0-060

0.281
0-359
0546

0-271

4 532
0-298
0-218

0-157
3-414

2-Io8

0-857
2-205

J-0-218

0^217
0 447
.V6a9

0-443

1-074
0-550

0-309
0-547
2-4»

^M3

0-861
0-110

0-aoi

0-118

0-311

l-TK
0^1

C.ZL

B&OOB8TO

A yariety of Jasper (q. v.)

Aji instniment for directing a stream of air throngh a flame, dtha
by blowing with the month or with bellows. The flame of a candle, of a lamp with
a simple wick, or of an ordinary gas-jet, consists of three parts. The dark central
portion immediately surrounding the wick or bnmer, consists of combustible caseoas
matter, not yet burned ; this is surrounded by a highly luminous cone, which depoeiti
soot on a cool body held within it ; and outside of all is a thin pale blue enydope
which gives little light, but has a very high temperature. It is here that the oombio-
tion is most complete, the carbon and hydrogen finding sufficient oxygen to convert
them into water and carbonic acid. But in the middle luminous cone, the supply of
oxygen is not sufficient for oomplete combustion, and consequently the hydrogen,
which bums most easily, takes up the whole or the greater part of it, while the eariwn
is set free in the form of minute solid particles. If now a jet of air be directed throogh
the middle of the flame, a double combustion takes place, the combustible matter
uniting on the outside with the oxygen of the air, and in the interior with that which
is supplied by the blast. In this manner, an intensely hot flame is produced, appli-
cable for fusions, reductions, and a rariety of operations in r^bAmmAl analysis ; and
likewise for soldering metals and working glass.

The best and cheapest form of the mou£h-blowpipe for chemical purposes, is that in-
vented by Black. It consists of a tube of tin-plate {J^. 161), about 7 inches long, and f of

an inch broad, tapering to ^ of am inch, where a small
mouth-piece is soldered. At the wide end a is
inserted a small cylindrical tube of brass, about 2
in. long, supporting the nozzle, which may be of
brass or platinum.

The tube is slightly conical at the end where
the jet is flxed, and the latter is tibtus made to fit
on without a screw, which would soon be injured
by the high temperature to which it is exposed,
and would then be difficult to remove for the
purpose of cleaning. The nozzle is drilled from a
solid piece of metal, and in the form shown at b in
the figure. One of the chief excellencies of this
form of blowpipe, is the efficient manner in which
it condenses and retains the moisture of the breath,
and prevents its projection on the heated assay.
The blowpipe may also be provided with a move-
able trumpet-shaped mouthpiece, against which the
lips, partially open, may be pressed during the act
of blowing ; in this manner, a strong blast maj be
kept up for a considerable time with very Httle
fatigue. The use of such a mouthpiece is strongly
recommended by Flattner in his valuable treatise
on the blowpipe ; but it is scarcely necessary, ex-
cepting when the blast has to be kept up for a long
time, as when the blowpipe is used forqnantitatiTe
analysis.

To use the mouth-blowpipe with success, it is necssary to acquire the art of keeping
up a steady blast of air for some time. For this end, the air must- be supplied from
the mouth, not directly from the lungs, which could not, without fatigue, afford a
sufficient stream. The mouth-piece of the instrument being placed between the lips,
the mouth is to be filled with air till the cheeks become distended as in playing on a
wind instrument. The current of air is then forced through the tube by tiie action of
the muscles of the chocks, and during the blast, the communication between the chest

BLOWPIPE.

613

Fig, 102.

Fig. 103.

and month Is dosed, respiration being carried on through the nostrils. The mode of
effecting this is difScnlt to describe, but the right method of blowing is easily acquired
by a little practice.

The qnauty and intensity of the flame vaiy considerably according to the strength
aud direction of the blast. If the nozsle of the blowpipe is inserted into the middle oi
the flame, a little aboxe the wick, as shown in fig, 102,
an donated flame is produced, consisting of an outer
and an inner cone, the former having a yellow, the latter
a blue colour. The outer flame is an oxidising flame.
kn. oxidable substance, such as lead or copper, placed
at or just beyond the point a of this flame, is strongly
heated in contact with the oxygen of the air, and is
therefore brought just into the condition for taking up
oxygen. The greatest heat is at the point of the inner
flame, the combustible gases being there supplied with
just the quantitr of oxygen requii«d to consume them ;
and between this and tiie point of the exterior flame, is
a quantity of combustible maimer, very hot, but not

yet burned, and therefore disposed to take oxygen from any compound containing that
element. This part of the flame is therefore a reducing flame. A piece of ordinary
p^lass containing lead, turns black and opaque when heated in this part of the flame,
m consequence of the reduction of the lead ; but by afterwards heating it in the outer
flame, the lead is reoxidised, and the transparency restored.

Bnt the reducing power of a flame produced m the manner just described, is not
Tcry great, as any one may couTince himself by tarying to reduce oxide of copper or
oxide of tin in it without the aid of a reducing agent. The flame is for the most part
an oxidisins flame, especially if the aperture of the blowpipe is large and gives a good
supply of air. To obtain a^ood reducing flame, it is necessazy to use a blowpipe with
a small aperture, and to adjust the point, not within, but just outside the flame, and
to blow rather over than through the middle of the flame. In this maimer, the flame
is less altered in its general characters than in the former ease, the chief
part consisting of a large and luminous cone, containing a considerable
quantity of free carbon in a state of intense ignition, and just in the
condition for taking up oxygen.

Snbstances to be heated in the blowpipe flame, are supported, some-
times on charcoal, sometimes in spoons or forceps made of platinum,
or on platinum foil or wire, sometimes on small capsules made of clay
or bone-earth. Charcoal is used chiefly in experiments of reduction.
The substance to be heated is placed in a small hole scooped in the
side of the charcoal, not at the ends, because in the latter position, it
is more likely, when in the fused state, to sink into the pores of the
charcoal. Clay basins are chiefly used in the quantitative assaying
of ore& They are made of fire-day kneaded into a stiff paste with
water, pressed into shape in a box-wood mould {fi^, 103), then dried
and calcined. Instead of these, however, very thin porcelain basins,
which may be procured ready made, may be used with advantage.
Basins or cupels of bone-earth made in a similar manner, are used for cupelling silver
and gold with lead. The oxide of lead formed in the process, sinks into the porous sup*
port leaving the silver or gold in the form of a metallic button.

Blowptfb Analysis. — The blowpipe is an indispensable instrument in qualitative
analysis, as it serves to recognise the presence of many substances with greater facility
and certainty than could be obtained by analysis with liquid reagents, especially when the
quantity of substance to be operated on is but small. Generally speaking, however, it
is not safe to trust to the indications of the blowpipe alone, inasmuch as many substances
give but indistinct reactions when submitted to this mode of examination, and are apt
to be completely overlooked when present together with others whose indications are
more decided. In a mixture of iron, nicked and cobalt, for example, it would be
scarcely possible by the blowpipe alone to recognise anything but cobalt^ even though
that metal might be present in small proportion only as compared with the others. It
is best, therefore, to use the blowpipe, and in general, the mode of analysis by the dry
way, as a means of determining the general cnaracter of a compound or mixture, and
detecting certain of its constituents, and thus obtaining an indication of the best
mode of proceeding with the more complete analysis by the wet way.

A concise account of the behaviour of the several elementary bodies, and their
principal inoiganic compounds when heated per se^ and with certain reagents, is given
in the article Analysis (Inoboanic), (p. 213^ ; and these characters will be described
in greater detail in treating of the several elements and compounds. The table on

BR 3

614

BLOWPIPE.

Behaviour of Metallic Oxides before the Blow-

A clear bead is formed by fusing the flnx on a loop made at the end of a platinom-wire: die besd is

in the reducing flame, it is sometimes advisable to employ charcoal instead of platinum-wire. Tks

'emjployed. In this table h. signifies hot ; c. cold ; supers, that the bead is i^er-

Colour
of the
Bead.

Colour-
less,

With Microcosmio Salt.

.^^

In outer or oxidising Flame.

Silica swims undissolved. Alumina^ Slan-
nic oxide. All AUkaline earths, and
iS^^>l« (supers, opaque). TatUalic, Colum-
bicy Titanic, Tungstie anhydrides; Zinc-,
Cadmium^, Lead-, Bismuth, Antimony
oxides not sat : (supers, yellowish).

Yellow

brownish.

Bed.

Violet

Amethyst.

Blue,

Qreen.

Grey and
Opaque.

h. not sat Ferric and Ceric oxides, h. Va-
nadic anhydride, Uranic oxide. Oxide (^
Silver, c Nic&el-oxide,

h. Nickel-oxide, h. supers. Ferric and
Ceric oxides.

Manganic and Didymie oxides.

Cobalt-oxide, c. Cupric oxide.

h. Cupric axidct Molybdic anhydride.
Ferric oxide containing cobalt or copper.
Chromic and Uranic oxides.

In inner or reducing FLune.

Silica swims undissolved. Alumina, All
alkaline earths and earths iwaptn. opa^X
Ceric, Didytnic, Manganic, Stannic oxides.

h. Ferric oxide (reddish). Titanic aniyd.

h. Ferric oxide, c. TOanie and Tnngdie
anhydrides containing iron (blood-red).
Cupric oxide.

c. Titanic anhydride. Colnmbons Mif-
dride (not sat).

Cobalt-oxide. Tungstie anhydride, M-
obous anhydride (supen.)

Chromic and Uranie oxides, Fanadiewi
Molybdic anhydride.

c. Oxides of Silver, Zinc, Cadmium, Lead,
Bismutht Antimony : Tellurous enJ^dride.

BLOWPIPK

615

pipe with Microcosmic Salt and Borax.

dipped inio the finely-powdered inlMtanoe nnder ezaminatioxi, and again heated. In heating
colour of the head freqnently Taries with its temperature, and with the quantity of oxide
aatnrated with oxide ; not sat. that it ii not completely saturated with oxide.

With Borax.

Tn outer or oxidising Flame.

In inner or reducing Flame.

Silica^ Alumina, Stannic oxide. — Supers,
opaque : Alkaline earths and Earth, Oxide
o/sUver, Tantalie, Columbie, Tellurtm
anfydrides. — Not sat: Titanic, TStngstic,
Moljfbdie aniydridet. Zinc-, Cadmium',
Lead-, Biemmth-, Antimony-oxida.

Silica, Alumina, Stannic oxide. — Supers,
opaque : Alkaline earths and Earths, T^n-
thanic and Ceric oxides, Tantalie anhyd.
Manganic and Didymic oxides, h. Cu-
pric oxide.

h. Vanadic anhydride, h. not sat Ferric
and Urame oxides, h. supers. Lead-,
Bismmtk't and Antimonioui oxides.

Tungstie anhydride; Titanic, Fanadie,
and Molybdic anhydrides (hrownish).

h. Ceric and Ferric oxides, c. Nickel-
oxide (led-hrown). h. supers. Chromic
oxide.

c. Cupric Oxide (supers, opaque).

Manyame and Didymic oxides. Nickel-
oxide containing cobalt.

•

CobaU-oxide. c Cupric oxide.

Cobalt-oxide.

e. Chromic oxide, Vanadic anhyd. h. Cu-
pric oxide. Ferric oxide containing copper
or cobalt.

Ferric t Uranic, Chromic oxides, c. Fa
nadic anhydride.

The same as with microcosmic salt. Also
Nickel-oxide, and (supers.) Columbous an-
hydride.

616

BLOWPIPE.

Fig. 104.

page 614 (taken from Coniiigton's " Handbook of Analysis,") exhibits in a eonToieot
form the colours imputed by metallic oxides to borax and microcosmie salt, vben
heated therewith in the oxidising and reducing flames. (Tor further deta^ Me
** Chemical Manipulation," by C. Sreyille Wlliams, London : Van Voont ; also* espe-
peciaJly for the method of QuantitatiTB Analysis irith the blowpipe: Plattnei's '*Pro-
bierkunst mit dem Lothrohre," or the translation of that work "Chi the Use of the Blow-
pipe, &C.," by Br. Musprattt London, I860.]

Tabui Blowfifb. — For sealing and bending ^ass tubes and constmctiiig ^a»
apparatus of yarious forms, it is oonyenient to hare the blowpipe mounted on a fixed
fcupporty and when a flame of oonaidersble power is iwpiired, the blaat most be top-
plied by bellows worked with the
foot. A very oouTenient fonn of
blowpipe for these purposes is that
inyented by Herapath, andrepre-
presented in fig. 1 04. a is a flexible
tube attached to a stopcock 6, which
communicates with a tube c i, bent
at right angles at d^ where a T-
shaped tube efg slips on by raeaos
of the piece f. The blowpipe jet k i

Masses into the longer ann 5l the
'-piece, and fits somewhat tigfatlj;
ktisB, second piece of fiexiUe
tube terminating in a mouth-piece,
or connected with a blowing appi-
ratus. On turning on the gas, it
passes in the direction marked bj
the arrows, and is to be inflamed ft
e. On blowing with the month, or
by means of a pair of bellom into tiie
tube k If the ignited gas takes the
form of a blowpipe flame of great
power, the nature of which is en-
tirely under control by means of the
stopcock 6, and also by rcgnlatiiig
the quantity of air supplied through
the tube k I. The T-shaped piece is
moyeable at /*, eo that the jet ms^
be directed to any position. The
apparatus may be mounted on a heayy foot, and connected with the gas-supply, by
means of the flexible tube, so that it can be placed in any required position on the labo-
tory table ; or it ma^ be permanently fixed on a table specially deyoted to the purpoee,
and haying beneath it a pair of bellows worked by a treadle.

OxTHTDSOOBN Blowfipe. — The power of the blowpipe flame may be immensely in-
creased by supplying it with oxygen gas instead of atmospheric air. The apparatnB
last described is yery well adapted for the purpose, the flexible tube kl bemg con-
nected with a gas-holder containing oxygen. Ab the oxygen and the combustible gas
would meet only at the yery place where the combustion is to take place there wonld
be no danger of explosion. Still greater intensity of heat is obtainea by a flame com-
posed of pure oxygen and hydrogen in the proportions required to form water. Nnme-
rous forms of apparatus haye been contriyed for burning this gaseous mixture, the
object being so to contriye the jet that the gases shall be there mixed in the exact
proportions required, and at the same time to preyent danger of explosion by premsr

«. --.- ture mixture. The best form is that

n. ^*^' ^"^- shown in fig. 106, in which A is a

brass tube filled with a number of
layers of wire ^use pressed dosely
together, or with a bundle of Teiy
thm brass wires placed parallel to
the axis of the tube, and firmly
wedged together by a stout conical
wire driyen into the middle, so as fo
form a collection of extremely narrow
tubes. The gases are supplied by
the tubes O H, connected with gas-
holders or loaded caoutchouc baga,
one containing oxygen the other hydrogen. To the other end of the brass tube A

^>^

BLUE— BOHEIC ACID. 617

•

is attached a jet) the extremity of which is fonned of platinum. The gases mix in
the tube A, and pass on through the meshes of the vire-ganze or the interstioes be-
tween the thin brass wires to the point of the jet) where they are set on fire. The
proportions in which the eases are supplied are regulated by stopcocks on the tubes
0 H. The appearance of me fiame, which should be a Tory narrow cone of a pale blue
colour, indicates when the right proportion is attained, and this having been once
determined, the position of the stopcocks may be marked, so as to ensure the right
proportion of the two gases in all future experiments. The use of the wire-gauze or
Dnndie of thin wires in the tube A is to supply a mass of good conducting material,
which shall prerent the flame firom passing badkwards through that tube (see Flaxb).
The heat produced by the oxyhydrogen flame is the greatest that can be produced by
any artificial means, except by the electric current. Thick platinum wires melt in it like
wax in the fiame of a candle. By itself however, it gives but little Ught ; but any non-
voUtile and incombustible solid substance held in it becomes intensely luminous. If
the point of the fiame be directed on the rounded edge of a cylinder of quick lime, a
pure white light of dazzling brilliancy is produced, imerior only to the dectric light.
It is called the Dntmmond lights and has been used for lighthouses.

BSVa, VRVBaZAW. See Ctanidbs of Ibon.

B&mip 8AXOV. The best Saxon blue colour may be made with the following
composition : mix one ounce of the best powdered indigo with four ounces of sulphuric
acid in a glass bottle or flask, and digest it for an hour at the heat of boiling water,
shaking the mixture at different times ; then add 12 oz. of water, stir the whole well,
and filter when cold. Poemer adds 1 oz. of good dir potash at the end of twenty-
lour hours, and lets this stand as much longer before diluting with water. The doth
should be prepared with alum and tartar.

BO]>JUilT& A mineral related to allanite, discorered by Kemdt in the oli-
godase between Boden and Mauersberg, near Marienberg in Saxony. Found only in
Hl-defined prisms [rhombic?] of 110^ to 112°, without trace of cleayage. Hardness
6*5. Specific eravity 3*523. Eeddish or blackish-brown. Streak dirty white. Opaque
with Titreous mstre. When stron^y heated, it exhibits incandescence like gadomute.
Fusible only on tiie acute edges. Decomposed by strong acids. Analysis gave : 26*12
SiO« ; 10-33 A1«0« ; 1204 Fe*0 ; 17*44 Y«0 ; 10*46 Oe«0 ; 7*56 La«0 ; 1-61 Mn«0 ; 6*32
Ca*0 ; 2-33 Mg»0 ; 1*21 K>0 ; 0*84 Na'O ; and 301 H*0 : whence may be deduced the
formula 6(3MK).SiO«) + 2Al<0».SiO«, the water being regarded as basic. Associated
with this mineral are found black amorphous gz^s of another mineral, Maromontitet
containing the same elements, but not exidbiting incandescence when heated. (K e r n d t,
J. pr. Chem. xliii. 219, 228.)

BOO-SUTTBR. A fatty substance found in the peat-bogs of Ireland. It was
first examined by Luck (Ann. Ch. Pharm. liv. 125), afterwards more exactly by
Brazier (Chem. Gaz. [1852], 375). It is yeiy soluble in alcohol, and crystallises
from the solution in a network of slender needles. It melts at51°C. (Luck), the
crude fat at 45°, but after repeated crystallisation from alcohol and then from ether,
at S7P to 52*7° (Brazier). It gives off the odour of acrolein when heated. By saponi-
fication with potash, it yields an acid, Butyrolimnodic acid (Bogbuttersaure), to which
Lack assigned the improbable formula C^IP*0^\ but according to Brazier, this acid
has the same composition as palmitic acid, (7*^iEf 0^, or C^H^O', and melts at 53° C.

COAXto See CoAi^

See Ibon.

BOS8ZO ACZB. CH^O* « C'HH)*.ff.O«.— An acid occurring in small quantity
in black tea, together witii quercitannic acid (Kochleder, Ann. Ch. Pharm. Ixiii.
202.) To prepare it, a decoction of black tea is precipitated at the boiling heat with
acetate of leaa ; the filtered liquid is left to stand for twenty-four hours, and again
filtered to separato a small sediment ; the clear solution is mixed with a quantity of
ammonia sufficient to neutralise the acid reaction ; the yellow precipitate stirred up
with absolute alcohol, and decomposed by sulphuretted hydrogen ; and the filtrate left
to evaporate in vacuo oyer oil of vitrioL The residue is dissolved in water, and the
solution is left to evaporate in vacuo, then dried at 100° C, this treatment being repeated
three times, and the residue finally lefl for three weeks in vacuo.

The acid when pulverised is of a pale yellow colour, like quercitannic acid. Melts
at 100° C. into a mass which draws out into threads. It cakes together when exposed
to the air, even for a few minutes, and deliquesces very quickly. Colours ferric
hydrochlorato brown, without precipitation. Dissolves in all proportions in water and
in alcohol.

By dry distillation, it yields a light charcoal, and a distillate which smells of acetic
add and blackens iron ^alts. The aqueous and alcoholic solutions decompose when
evaporated in contact with the air. Tne add is dibasic^ the formula of ite normal
salts being C'H"0«.M».0*.

618 BOLE— BOLETUS.

The barium'^altf CB'BafO' + IPO, ifl obtained as a yellow pndpitate "by nixing
the eolation of the acid in aqneona alcohol, with a slight excess of bsjyta-water. The
n&rmal kad-^ait^ C'H'Pb^O* + HH), is obtained by mizinff the alcoholic eolation of
the acid, after concentration oyer potash in yacno, with aleoholic acetate of lead, vash-
ing the precipitate with alcohol, and drying at 100° C. It is white, with a tinge of
grey. A basic leadsalif C'H"f'b*0*.Pb*0, is obtained by precipitating the aq[neoas
solution of the add with an ammoniacal solution of acetate of lead. It fbnna an egg-
yellow precipitate. (Rochleder.)

BOXUOrO FOZWT. See Hb^T.

aO&S. A massive mineral, haTing a perfectly oonehoidal fracture, a glimmering
internal lustre, and a shining streak. Its colours are yellow-red, and bro^pniish-bUck.
It is translucent or opaque ; soft, so as to be easily cut and to yield to the nail It
adheres to the tongue, has a greasy feel, and falls to pieces in water. Specific gn^
1*4 to 2. It may be polished. If it be immersed in water after it is dried, it &Di
asunder with a crackling noise. It is a hydrated silicate of alumininm, in vUch the
aluminium is more or less replaced by iron (ferricum).

The following are analyses of bole:

SIO*

A1«0»

Fe«0»

Ca*0

HS>0

K«0

UH}

a. .

. 41-9

20^

12-9

S4-9 «s 99-9 rWackeoToder)
f4-08«BlOI-OS(Ldvig)

h, .

. 42i)0

1404

10-oa

0-&9

0-48

0. .

. 41-05

25*0S

809

0*4ft

0-50

.„

14-09 ■■ 99*14

d. .

• 4*2 00

90-19

8-53

2-81

9 01

0-50

94-00 — 99^7(ZenBcr)

e. .

. 459S

9914

—

390

—

95-66 -a 97-89 (RuamdflMqK)

/. .

. 47-OS

18-46

e-as

1-00

—

O-90*

95-18 — 99HB (TbomMB)

o, from Sasebuhl, near Oottingen ; b, from Ettinghausen ; c, from Gap de PnideUes;
d from the Brechte Berg in Silesia. The composition of these specimens agreee neadj
with the formula 4MK)*.9SiOM8HK>, which, by substituting m » {M, maybe ledoced
to m*H^Si*0*' + 4aq ; e, from Stolpen in Saxony, is represented nearly by the fonnnls
Ca'K).2Al*0».4SiO«+4aq « (Ca«fli»H*)Si*0»« + 3aq ; / from the Giant's Canseway
in Ireland, is nearly HH)*.3SiO* -i- 6aq, which mar be redneed to (m>H^O*+aq.
All these are formulse of orthosilicates. {Rammdsoer^$ Mineralehemu^ 578; Dana,
ii. 262.)

BO&OOVZAV BTOVa. Lemeiy reports that an Italian shoemaker, named
Vincenzo Gasdarolo, first discovered the phosphoric proper^ of the Bolognian stone.
It is the ponderous spar, or native sulphate of baiyta. If it be first heated to ignition,
then finely powdered, and made into a paste witii mudlase, and tiiis paste, dirided
into pieces a quarter of an inch thick, and dried in a moderate heat, be ezpoeed to
the heat of a wind furnace, by placing them loose in the midst of the charcoal, a
pyrophorus will be obtained, which, after a few minutes' exposure to the son's rajs,
will give light enough in the daA to render the figures on tne dial-plate of a ▼ateh
Tisiblei U.

80&VnO AOIB. The name eiven by Braconnot to the acid A-riaHw^ in Bdldiu
pseudo'ifftiiarius, since shown by Bolley and Dessaignes to be identical with fomane
add.

80&XTUS. A ^nus of mushroom, of which several specieB have been sabjeeled
tochemical examination by Braconnot and Bouillon La u- range (Ann. Chim. hen.
272) ; and more recently by Bolley, (Ann. Ch. Pharm. Ixxxvi 44), and Dessaignes
(Compt. rend, xxxvii. 780).

The chief constituents of these fungi are extractive matter, nitrogenous principles,
the so-called fiingin {q. v.), sometimes mannite, perhaps also fermentable sogar and
certain organic acids, called /Wn^ and boUtic acids by Braconnot, but probably con-
sisting, according to Dessaignes, of malic or fumaric acid. The ash contains potash,
lime, magnesia, phosphoric acid. See. The species which have been examined are
BoUtua bovinus (Crell's Chem. Ann. 1785, p. 280), B, igniariiu (Ann. Chim. li 75\
B, jyglandU {ibid, Ixxxvii 226), B. laricis (ibid, Ixxx. 272), B. sulpkumu and B,
vitcidtu (TrommsdorfTs N. Joum. ix 240).

BoUtua laricis^ is used on the continent in medicine under the name of agorie. It
is in white, light, friable pieces, the outside of which is like dark-coloured leather. Its
taste, at first sweetish, soon becomes bitter and acrid. Its infusion in water is yellowish,
sweet tasted, and reddens vegetable blues.

Boletus igniariua is found in most countries, and particularly in the Highlands
of Scotland, on the trunks of old ash and other trees. The French and Germans pre-
pare it abundantly for making tinder, by boiling in water, dicing beating it, steepii^
It in a solution of nitre, and again drying it. In France it is called amadou, in this
country German tinder. It has been recommended in surgery for stopping haenwas
rhage from wounds. It imparts to water a deep brown colour and an astringent taste.

* Chloride or icMliaiiu

BOLORETIN — BONE. 619

A resin of earthy aspect, found in the fossil fir-wood of Danish

peat-bogs, and in the needles which fall from the growing trees. The fresh shoots
contain but little of it ; but it increases with the age of the needles, and is most abun-
dant in autumn and winter. It is prepared by treating with boiling alcohol the grey
earthy matter found in hollow fossU fir-stems, and precipitating the foreign matters
with acetate of lead. The solution on cooling deposits the Iwloretin as an earthy
mass, which may be further purified by repeated solution in boiling alcohol, with
addition of hydrochloric acid to precipitiGite lead. It is soluble in ether, but not in
cold alcohoL Melts at 75^ — 79^ C. Its composition isyariable, but it appears always
to oontain the elements of oil of turpentine plus water. It does not, however, yield
oil of turpentine when treated with phosphonc anhydride. (Forchammer, Ann. Ch.
Phaim. xli. 44.)

BO&TOSITB. A variety of olivin, Mg*SiO^ occurring in crystalline granules,
disseminated through limestone at Bolton in Hassachussets. Colour ash-grey, wax-
vellow, or yellowish-white, with vitreous lustre. Streak white. Transparent or trans-
lucent Specific gravity 3*008 (Silliman); 3*21 (Brush). Hardness in unaltered
specimens » 6 or rather greater (Brush). Cleavsge distinct in one direction. In-
fusible before the blowpipe ; slightly attacked by hydrochloric acid. The following
analyses agree nearly with the formula Mg^SiO^ or 2Mg'O.SiO': abyJ. L.Smith
(SilL Am. J. [2] zviii. 372) ; 6 by G. J. Brush (ibid, zzvii. 396) :

SiO* Mg»0 Fe«0 Ca«0 A1*0» Jj^J^Jj

a, 42-81 6116 277 . . 018 1-90 - 98-32

b. 42-82 64*44 1-47 086 trace 0*76 » 100*43

Analyses by B. Silliman (Sill. Am. J. [2] viii. 16) and v. Hauer (Kenngott's
Uebersicht, 1864, 90) gave Lirger amounts of silica and alumina, and less magnesia ;
but the mineral appears to have been but imperfectly decomposed.

aoiiVS. A highly ferruginous day fix>m Sinope in Asia Minor, containing, ac-
cording to Klaproth, 320 Si(>«, 266 A1*0», 210 Fe«0», 170 H*0, and 1*6 NaCL

BOHB. (E. V. Bibra, Chemische Untersuchungen iiber die Elnochen und Zahne,
&e. Schweinfurt, 1844, p. 1—268, 289—386 ; E. FrAmy, Ann. Ch. Phys. [3] xlvii.
47 — 107 ; also Traits de Chimie, par Pelouze et Fr^my, 2nd edition, vi. 261 ; C. J.
Lehmann, Physiological Chemistry, iii 12, and Gmelin's Handbuch, viii. 429.) —
Bone-tissue is of two kinds, campaot and spongy. The long tubular bones of the
extremities are formed mainly of the compact tissue, while the flat bones, as those of
the skull and pelvis, and the short round bones, consist of an external compact layer,
enclosing a mass of the more porous or spongy tissue. The outer surface of bones is
covered with a thin membrane {ih^ perio8teum\ traversed by great numbers of nerves
and bloodvessels, while the inner surfaces of their cavities and channels are lined with
a still thinner membrane. These tubes and cavities contain a fatty substance called
nusrrow. The substance of the bone itself exhibits a laminated structure, the indi-
vidual layers being concentric with the tubes and channels containing the marrow.
These layers consist of an amorphous substance, intersected by cavities, from which
proceed mnnmerable intercommunicating channels.

The true bony tissue, distinguished from the external and internal membranes, the
marrow, and the various fluids contained in the channels and cavities above-mentioned,
consists essentially of an oisanic substance, called hone-cartUage^ or ossein^ and an in-
organic substance, composed mainly of tribiuic phosphate ofcalciuvi^ Ca'PO\ together
with smaller quantities of phosphate of magnesium, Mg^O\ carbonate of calcium, and
Jiuoride of calcium.

If a bone be incinerated without previously reducing it to powder, and washing out
the blood and other extraneous fluids contained in its cavities, the ash will likewise
contain small quantities of alkaline sulphaies, carbonates^ and chlorides, and of iron,
but these are derived from the liquids just mentioned, and do not properly beloug to
the bone itself.

The bone-cartila^ or ossein may be separated fh)m the earthy matter by macerating
a bone for some time in dilute hydrochloric acid. The calcium-salts then gradually
dissolve, the mass becomes translucent and soft, and idtimatdy the cartilage is left
free from mineral matter, and retaining the form of the bone. By boiling in water, it
is converted into gelatin and dissolves, forming a solution clouded by suspended fat
and vascular tissue, and solidifying in a jeUy on cooling. When freed from these ex-
traneous matters by digestion in alcohol and in ether, it is found to have the same
proportional constitution as gelatin, as may be seen from the foUowin^j^ table, in which
the composition of bone-cartilage from various sources is compared with that of pure
gelatin (isinglass).

620

BONE.

Compositi^m of Gelatin

and Bone-eartilage

•

Gelatin :

CarboD.

Hydrogen.

Nitrogen.

Oxygen.

From Bone

50-40

6-64

18-34

24-64

Mulder.

„ „ (foflsil) .

60-40

711

1816

24-36

T.Bibnu

„ Isinglass .

60-76

6-64

18-32

24-69

Mulder.

Bone-cartUage :

From femur of Ox .

6013

7-07

18-46

24-35

▼. BibnL

„ Pipa

60*46

7-08

18-21

24-24

„ Kib of River Carp .

60-32

7-22

18-42

2400

t»

„ Ox ...

49-81

7-14

17-32

26-67

Fi^my.

„ Calf

49-9

7-3

17-2

26-6

,, Owl . •

49-06

6-77

Bone-cartilage also contains sulphur, which v. Bibra estimates at 0*216 per cent.

The chief difference between bone-cartilage and gelatin is, that the latter dissolves
easily and immediately in boiling water, whereas the former is insoluble in water until
it has been oonverted into gelatin, which requires long boiling.

According to Fr^my, the bone-cartilage has likewise the same composition in Toxmg
and in old animals. Fcetal bones, however, do not appear to yield gelatin when boiled
with water; or at all events, Schwann (Mikrosk. Unters. 1839, p. 3), could not ob-
tain that substance &om the bones of a fcetal calf, nor Hop pel (Arch, t patboL Anat.
V. 174) from those of a rabbit, down to the last hours of intra-uterine Uie. In fottU
bones, the cartilage is often found to be converted into true gelatin. The cartilage of
diseased bones does not appear to differ from that of healthy bones (v. Bibra and
others). In the bones of certain water-birds, and in the spines of certain fishes,
Fr^my found a substance resembling ossein in physical characters, and isomeric with
it, but differing from it in not yielding gelatin when boiled with water.

Quantitative Analysis. — The bone is first reduced to fine powder by rasping, then
washed with water to remove soluble salts, &c, and digested with ether to remove
fatty matters. Care must however be taken not to continue the washing with water
too long, as by the prolonged action of water, small quantities of the phosphates of
calcium and magnesium are dissolved out, the quiantity thus removed increasing as
the organic matter of the bone passes more and more into the state of patze£u!tioiL
(Wohler.)

The bone purified as above, is next incinerated in a muffle (p. 418), till it becomes
quite white, then moistened with solution of carbonate of ammonium, to restore uiy
carbonic acid that may have been driven off £rom the lime, and again heated just
sufficiently to expel the excess of carbonate of ammonium. The difference between
the weight of the dried bone before ignition, and that of the ash, gives the amount of
cartilage.

The analysis of the ash is made for the most part by the ordinary methods (p. 419)w

The carbonic acid must be estimated by one of the methods given under Alxau-
MBTRT (p. 117), first in the unignited bone-powder, and afterwards in the ash. The
first gives the amount of carbonate of calcium in the bonct and from the dififorenee
of the two determinationB, the quantity of lime which was in combination with oiganie
acids may be found. The amount of carbonate of calcium cannot be coirectly esd-
mated by precipitating with carbonate of ammonium the lime which remains in solu-
tion after the phosphate of calcium has been precipitated by caustic ammonia. The
adoption of this method in the earlier analvses, led to the incorrect conclusion that
the calcium-phosphate contained in bone-eartn was 8Ca*0.P'0*, instead of SCa'OJ'^.

The amount or fluorine in bones has seldom been determined qnantitatiTely, the
calcium really existing as fluoride being generally reckoned togetiier with the car-
bonate or phosphate. M ar c h an d, however (J. pr. Chem. xxvii 83), found in a human
thigh-bone 1 per cent., and Heintz (Wien, AkaaBer. 1849, p. 61), found in a similar
. bone 2-06 per cent fluoride of calcium. In fossil bones, the proportion of this salt is
often much greater.

As bone-tissue is veiy hygroscopic, it is necessary, in comparing the quantities of
water which different bones retain, after drying in the air at ordinary temperatures, to
notice the indications of the barometer and thermometer before exposing the bones to
the heat of the water-bath or oil-bath.

BONE.

621

The most eomplete investigations that have been made of the composition of bone,
an those of t. Bibra and "^imj. The following table exhibits the percentage of
inoigamc matter in human bones of Tarious ages, as detennined by t. Bibra.

Name of Bone.

PercenUg*
of Ash.

Name of Bone.

Percentage
of Ash.

Maleftgius, 7 months:

Woman, 25 years :

Femor, tibia^ humerus .

59-1 to 59-6

Femur, tibia, fibula, ulna,

Flemale fattu, 7 months

64-5 to 65-4

OS occipitis
Humerus

68-4 to 68-8
69-25

Boy, 2 months :

Clavicule

67-51

Tibia ....
Atlas ....

65-32
64-07

Rib . . ,
Stemuib
Scapula .

64-57
51-43
65-48

Boy, jyear:

Vertebne

54-25

Femur ....

56-43

Os innominatum

59-97

Humerus

58-58

Tibia ....

56-58

Man, between 25 and 30 yrs.

Radius ....

52*52

Femur, tibia, humerus.

Ulna ....

56-51

ulna ....

68-0 to 69-4

Rib ... .

49-30

Os occipitis .

68-73

Scapula ....

49-71

Rib ... .

63-99

Boy^ 6 years :

Woman, 78 years :

Femur ....
Tibia ....

67-80
67-71

' w

Femur ....

66-81

Giri, 19 years :

Man, 58 years :

Femur ....

67-85

Femur, dense portion

68-53

67-71

„ spongy portion .

64-18

From these results it appears : 1. That the proportion of inorganic matter in bone
is smaller in youth than in age, although no regular gradation can be observed. 2. The
proportion of inorganic matter is greater in compact than in spongy bone-tissue;
greater also in the bones of the extremities than in those of the trunk ; greatest of all
in the thigh-bone. It appears, indeed, to be greatest in those bones which are most
moved, or have to bear the greatest strain ; this observation is corroborated by the
composition of the bones of birds (see below).

The difTerent orders of mammiferous animals do not exhibit any essential differences
in the proportions of inorganic matter in their bones, the limits being 64 and 75 per
cent. The bones of bir£ contain on the average a larger proportion of inorganic
matter than those of mammals, viz. 68*6 to 75*8 per cent. ; those of reptiles rather
less, 51*7 to 68-9 per cent. The bones of fishes exhibit great variety in the proportion
of mineral matter which they contain, e,ff, Bonj fishes: eel 51*62 per cent; cod
65-76; salmon 64*37; perch 59*40 per cent. Cartilaginous fishes: Snark 46-82 per
cent. ; lamprey 1*66 per cent.

Fr^my's r^ults agree for the most part with those of y. Bibra, excepting in the
proportion of organic and inorganic matter in bones of different ages, which, according
to Frimy, do not exhibit in tlus respect anv sensible variation. The bone of a foetus
was found to yield the same quantity of ash as that of a woman 97 years of age, and
the first bony particles that make their appearance in the midst of the cartilaginous
mass, which in the fcetus precedes the formation of true bone, were found to contain
the same quantity of min^al matter as the bone of an adult animal (see table, p. 621).
The greater brittleness of the bones in a^e is attributed by Fr^mv to the increase in
the proportion of the spongy tissue, the thickness of the haiu and aense portion of the
bones continually diminishing as age advances.

Fr^my'a analyses of the bones of animals belonging to different orders show, in
accordance with those of v. Bibra, that the bones of mammifers exhibit the same
average composition as those of man, the bones of herbivorous quadrupeds, however,
generally containing a larger proportion of lime-salts than those of flesh-eaters. The
bones of birds have nearly the same proportion of lime-salts as those of herbivorous
mammals, and those of reptiles nearly the same as those of carnivorous mammals.
The bones of fishes exhibit great diversity of composition, those of bony fishes being
very much like those of manmifers, whereas those of cartilaginous fishes are rich in
organic matter, and contain but a small proportion of mineral salts.

622

BONE.

Camparahve Analyses of Bones hdonging to different Orders of the Animal Kingdom,

Name of Bone.

Aih per

cent.

Pbo^

phateof

Caidum.

rhot-

phateof
Mag.

nesium.

Cvbonaie

of
Calcium.

Male fcetus, 4 montlifl ; femur . . . .

61-7

60-2

„ 6 months ; „ .

62-8

60-2

Female fcetus, „

630

„ 7 monthfl; humerus

62-8

Girl, bom alive ; femur .

64-8

60-8

Boy, 18 months ; „ .

64-0

61-5

Woman, 22 years ; scapula

63-3

600

„ 1, cranium .

641

67-8

1-7

10-9

,1 „ femur

64-6

tf ,) humerus

641

Man ; spongy part of femur .

610

„ dense „ „ . ,

65-0

Man, 40 years ; femur

64-2

66-9

1-8

10-2

Woman, 80 „ „ . . .

64-6

60-9

1-2

7-6

II 81 „ f» •

64-5

681

1-2

10-0

II ^** II II • • •

64-3

67-4

1-2

9-S

,1 „ spongy part of fei

nur .

69-7

64-0

1-2

„ 97 M femur .

64-9

670

1-2

9-3

Egyptian mummy ; femur

65-0

68-7

1-7

6-9

Daki; femur ....

640

Kink^jou; femur ....

62-0

Genet

70-2

Bitch; femur ....

621

690

1-2

Young lioness ; femur

64-7

600

1-6

6-3

Panther; femur

66-6

Morse

631

63-9

1-6

9-8

Babbit; femur

66-3

68-7

6-3

Guinea-pig ....

71-8

Indian elephant . . . ,

66*8

62-2

1*2

6-6

Java rhinoceros ....

6d-3

600

2-3

5*2

Horse; femur ....

70-4

Calf, still-bom ; spongy part of femur

61-6

60-6

1-2

II II dense „ „

64-4

69-4

1-7

6-2

„ 5 months ; femur ....

691

61-2

1-2

8*4

Cow, full grown „

70-7

II old „

71-1

»l II 19 *

71-3

62-6

2-7

Ox; humerus .

70-4

61-4

1-7

8-6

II II • •

70-2

62-4

1-7

7-9

Bull; femur .

69-3

69-8

1-5

8-4

Lamb; i, . . .

67-7

60-7

1-6

Sheep; „ • . ,

70-0

62-9

1-3

7-7

Goat; „ • . .

68-0

68-3

1-2

8-4

Cachalot,,

62-9

61-9

0*5

10-6

Whale; spongy part

57-6

Eagle .
Vulture .

70-6

60-6

1-7

8-4

66-2

Owl (Grand Dulre) .

71-3

61-6

1-6

8-8

Ostrich ; dense part

700

„ spongy part

670

Bustard .

71-1

Chicken .

68-2

64-4

6-6

Turkey

67-7

63-8

1-2

6-^

Partridge

•

70-7

65-4

Heron ....

70-6

62-5

1-6

10*2

Thrush ....

66*6

630

Humming bird ; bones of head

650

f> II II

limbi

)

59-0

BONE.

623

Table. — continued.

Name of Bone.

Teal

Turtle; carapace .
Land tortoiBe ; carapace .
Crocodile ; cutaneous bone
Crocodile ....

Serpent

Cod

Barbel

Sole

Shad

Carp .....

Pike

Eel

Tetrodon ; maxillary with teeth
Diodon ; spine of the akin

Shark

Bay; cartilage

„ scales ....
lifunprey ; head with teeth •

Ash per
cent.

73-6
64-3
64 0
64-6
64-0
67-6
61-3
60-2
640
60-
61-4
66-9
67-0
760
68-8
62-6
30-0
65-3
2*2

Phoa.
phate of
Calcium.

Phoa-
phate of

Mag-
nesium.

68-4
680
660
68-3
68*3

661

681
64-2
66-1

27-7
64*4

1-3
1-2
1-2

trace
0-6

1-3

1-2

trace

trace
trace

Carbonate

of
Calcium.

6-6

10-7
9-7

7-7

7-0

4-7
4-7
2-2

4-3
1-3

Diseased B on es,z— "Bones are subject to several diseases, in nearly all of which
the proportion of inorganic matter ia found to diminish. In caries^ the <^careous por-
tion of the bone is destroyed, without alteration of the cartilage, the latter still yield-
ing gelatin when boiled with water. In a carious femur, y. Bibra found the
proportion of inorganic salts reduced to 38*3 per cent., and in a portion of astragalus,
taken from the centre of the caries, it was only 18'6 per cent — In osteomalacia and
raehitiSt the proportion of mineral matter sometimes diminishes to such an extent, that
the bones bend under the weight of the body. Marchand found in the femur of a
rachitic child 72*20 per cent, cartilage, 7*20 fat, 14*78 phosphate of calcium, 3 0 car-
bonate of calcium, 0*80 phosphate of magnesium, and 2*02 sulphate of calcium, chloride
of sodium, iron (and loss). In the osteomalacia of adults, the tribasic phosphate of
calcium is converted into f-phosphate, 8Ca'0.3F'0* (Weber), and the bones sometimes
eontain a free acid. In tnis disease, and in the rachitis of children, the cartilage is
frequently altered in character, so that it no longer yields gelatin when boiled with
water. Exostosis is the formation of osseous tumours on the surface of bones ; these
tumours likewise contain an excess of cartilage. Sclerosis is the formation of cartilage,
and ultimately of true bony tissue within the medullary cavities and canals of the
bonea, which thus become denser and almost like ivory. Here also the organic matter
is generally in excess, and the carbonate of calcium is increased in proportion to the
phosphate. In osteoporosis^ which is a dilatation of the medullary cavities, &c., either
from the excessive development of the medulla^ or from the solvent action of fluids
infused into the cavities, the mineral matter is also found to disappear moro quickly
than the organic matter.

Fossil Bones, — When a bone is exposed to the air or buried in the earth, the
organic tissue gradually disappears, while the calcareous salts remain. In buried
bones, the tissue likewise becomes incrusted with various substances derived from the
surrounding soil, so that fossil bones often contain considerable quantities of carbonate,
sulphate, and fluoride of calcium, silica, &c, according to the nature of the fon^ation
in which they are embedded. The' proportion of carbonate of calcium sometimes
amounts to 67 per cent. The silica is in the form of quartz, that is, in the modifica-
tion which is insoluble in acids and in dilute alkalis. In some cases, the proportion
of tricalcic phosphate remains nearly the same as in the original bone, whereas in
others it is greatly diminished. The proportion of phosphate of magnesium does not
vary greatly ; it diminishes, however, to a certain extent when the phosphate of cal-
cium IS replaced by carbonate of calcium or by siliceous compounds. Many fossil
bones stQl retain a portion of their cartilage, which is sometimes also converted into
true gelatin.

624

BONE-BLACK.

Analyses of Various Fossil bones. (BWmy.)

Ash

Phosphate

Carbonate

Silica and '

r%.

Fluoride of iV.'pn^l

Ox, from the caves of Oretton ;

per cent.

Calcium.

Magnesium.

Calcium.

Caldum.

■acier.

metatarsal bone, external por«

tion haTlng the aspect of

wood

80-74

l-»

11-8

10-3

Internal portion of the same,

very friable . . . .

80-6

71-6

1-7

11-S

Spongy portion of the same
Rhinoceros, from Saosan ( Gers) ;

84-a

633

A-a

17-2

Tertebne

83*4

w-o

41-3

2-6

trace

Ribs of the same.

831

C6-8

27-&

1-4

trace

Hyena, from the caves of Klrk-

dale; long txme

75-5

72 0

1-3

4-7

SH)

Rhinoceros ; dorsal vertebra .

69-5

25-7

0-4

67*6

8-5

„ „ humerus.

730

82-4

0-4

64-0

0-S

„ „ teeth

90-4

6.V9

0-7

13-8

14-5

Mastodon; tusk ....

90*4

56-6

0*7

13-1

24-3

Bear ; dense part of bones .

839

69-7

0-4

S3-6

9-8

„ spongy part . .

70-7

28*1

1-2

675

14-0

tebra

84*0

S3*l

0-4

SO-4

19-4

Tortoise ; vertebra «

870

61*1

0-7

10-6

18-6

Animal Mackj Animal charcoal^ Beinschwarz. — A prodact ob-
tained bj heating bones to redness in dose Teasels. Large quantities of stinking gaa,
empyreumatic oil, and volatile alkaloids, are then erolveo, and there remains a blade
mass consisting of an intimate mixture of charcoal containing nitrogen, witli the
mineral matter of the bone, chiefly phosphate and carbonate of calcium. It posseases
the power of abstracting many solid substances from their solutions, and is used on a
reiy large scale as a decolorising agent in the refining of sugar. That it may posses
this property in the highest degree, the preparation must be so conducted as to leare
the largest possible quantity of carbon in the product, and at the same time to resdtf
it Tery porous. The air must therefore be carefully excluded during the ignition, and
the heat must be regulated so as not to cause the mass to cake together or become
agglutinated by the fusion of organic substances. The bones should be fresh ; those
which have lost much of their organic matter by putre&ction, either in the air or
underground, do not yield a sufficient quantity of charcoal They should be coarselj
comminuted and boiled to free them from fat, which would melt ajid yield a yezy com-
pact charcoaL

The yield of bone-black varies from 30 to 60 per cent, according to the com^iiion
of the bones. The long cylindrical bones of the extremities are best adapted for the
purpose ; they yield about 60 per cent of bone-black, containing 1 to 1| carbon to
9 pts. phosphate of calciunu Kibs, skidls, and vertebree yield a smaller quantity,
and not of good quality : hence it is better to use them for the preparation of
gelatin.

The carbonisation of bones is performed either in iron cylinders, like those used in
the distillation of coal, or in covered pots of cast-iron or cmcible-ware, heated in a
reverbcratory furnace; the latter method yields the best charcoal, but the former is
adopted when it is desired to collect the volatile products which az« given off (See
BoNB-On..) (For details and figures of machinery, see Un^s Dictionary of Art*,
Manufactures, and Mines^ i 369 ; Muspratfs Chemistry^ i 315 ; Handworterhuk d,
Chein. 2«* Aufl. ii. 767).

Bone-black is extensively used both as a decolorising and deodorising agent; it
likewise removes lime and its salts frx)m their aqueous solutions, and is accordingly
used for the purification of highly calcareous waters. In the refining of sugar, it
serves to free the syrup both from colouring matter and from lime. It decomposes
many metallic salts, sometimes absorbing the oxides or metidlic acids, sometimes
reducing them. It abstracts iodine, not only from solution, but even from its salts.
It likewise removes bitter principles and organic alkaloids from their solutions, and
has been recommended as an antidote in case of poisoning by such substances.

Bone-black which has been used for removing colouring matter and lime from
syrup or other liquids, may be revivified^ that is, restored to its original state, by the
following processes : — 1. Treating it with acids to remove the lime. — 2. Leaving it to
ferment or putrefy, in order to render soluble the oi^ganic substances which it baa
absorbed. — 3. Washing. — 4. Ignition. (For details, see the works above cited.)

Bone-black is sometimes used as a pigment; for which purpose it ia made into a

BONE-OIL— BORACITE. 625

pute with wmter, and finely tmlyeiued in a oolonr-milL The finest pigment of this
kind is ivory^Uackf which is obtained by the carbonisation of iyoiy.

Lastlj bone-black is nsed as a manuze, especially for cereal crops, being well adapted
foot this pnipoee^both by the phosphoric acid and the nitrogen wnich it contains. It is
diiefly efllcadons on soils wmch still retain a considerable qnantitp^ of decayed yege-
table matter..

WQIMM ftTTi IHppef* oU^ Animal oU, Oleum animale DiffdU, — ^This oil is obtained
in large quantity in the preparation of bone-black, by igniting charcoal in cylinders.
Similar prodncts are obtained W the dry distillation of other animal substances. The
original Dippd*» oil known in Pharmacy was produced from stages horn ; but all the
animal oil now met with in commerce, is obtained from bones in the manner aboye-
mentioned. It has been made the subject of a series of elaborate inyestieations by
Professor Anderson of Glasgow. (Transactions of the Boyal Society of ^linburgb,
xyi 4; xx. Part II. 247; xzi. Part L 219, and Part IV. 671. Ann. Ch. Pharm. Ixx.
32 ; hcxz. 44 ; xdy. 868 ; cr. 836. Jahreeber. d. Chem. 1847-8, p. 661 ; 1861, p.
476 ; 1864, p. 488 ; 1867, P. 392.)

Bone-oil is mainly a product of the decomposition of gelatinous tissue, inasmuch as
the bones used for the preparation of animal charcoal are boiled, before ignition, with
a lazse quantity of water, to depriye them of their fat (p. 624). The crude oil is
dark brown or nearly black, and nas a specific grayity of 0'970. It consists chiefly of
a mixture of yolatile organic bases» together with smaller quantities of adds and
neutral hydrocarbons.

On sumecting a laig^ quantity of the crude oil to firactional distillation, the first I of
the distilkte consists of about equal parts of a yellow oil and a watery liquid holcung
in solution sulphide, cyanide, and carbonate of ammonium, toge&er with sma^
quantities of yery yolatue organic bases. On supersaturating this watery liquid with
sulphuric acid, boiling for a while, then distilling with slaked lime, and immersing
sti^ of potash in the watery distillate, ammonia is giyen off with brisk efferyescenoe,
and a small quantity of oily bases separates on the surfoce of the potash-solution.

The remaining f of the distillate consists of oily bases of yarious degrees of yolatility.
On mixing them (together with the small portion of oily bases separated from the
watery liquid just mentioned) with excess of dilute sulphuric add, setting the mixture
adde Ibr some days, and frequently shaking it, then separating the stron^y add liquid
from the portion of oil still unacted on, and boiling it for some time in a still, an alka-
line liquia passes oyer containing jiyrrAo/, C^H^N, a weak base first noticed by Runge
(Pogg. Ann. xxxL 66) in bon^-oil and in coal-tar, and distinguished by the property df
imparting a deep purple-red colour to fir wood moistened with hydrochloric acid.

The remaining ada liquid, after cooling, is mixed with excess of slaked lime and
distilled, and the distillate is treated with solid caustic potash, which separates a
quantity of oily bases, while the watery liquid retains in solution ammonia and mithy-
famine^ which are giyen off on simply distilling the liquid, and may be condensed in
dilute hydrocUorie add.

On submitting to fractional distillation the mixture of oily bases separated by the
potash, a numb^ of bases are obtained from 66° to 100° C. belonging to the series
OH**«N, yia. ethylamine C«H»N, tritylamine C«H»N, tetryhunine C*H"N, and amy-
lamine C*H*^ ; and aboye 116° G. another series of bases are giyen off belonging to the
series OH* — "N, and isomeric with phmylamine and its homologues, yiz. :

Pyridine, C»H»N, boiling at 116-7° C.
Picoline, C^ETN, „ „ 136
Lutidine, C*H»N, „ „ 1646
Gollidine, C>Hi% „ „ 180

The non-basic portion of bone-oil yields by repeated rectification, a liquid boiling at
66*6° C, which, when exposed to a freezing mixture, separates into two oistinct layers.
The portions boiling at a higher temperature do not exhibit this property. They con-
tain bensene, and probably also homoloffues thereof, also alcokol-ntdictes, and nitro^
g€nou$ eompounda which are decomposed by sodium.

A yariety of hydrous dichroite (ii. 422).

BoroHte, Borate of Magnema, — ^A mineral occurring in ciystals
imbedded in gypsum and anhydrite at Lfineberg in Hanoyer, Segeberg in Hol-
stein, and Luneiolle, La Heurthe, in France. The cnrstals are monometrie ; cubes,
rfaomboidal dodecahedrons or tetrahedrons, generally hemihedral combinations with
a great number of faces, deayage octahedral in traces. Spedfie myity ^ 2*974.
Hardness * 7. Lustre yitreous, indining to adamantine. Colour white, indining to
grey, yellow, and green. Streak white. Subtransparent to subtranslucent. Fracture
condioidal, uneyen. Pyro-dectric, eyen when roassiye. (Dana, ii. 393.)

Boradte was formerly regarded as a borate of magnedum, 3M^.B*0*, containing a
Vol. L S S

G26 BOBIDES— POBNEOL.

mauJl qwmtity of iron ; bafcrecsent andyBCs have shown that it likewise eontabs
The mean results are as follows :

MfifO

Fe»0

HK)

30-67

l-«2

62-56

7-96

0-76 (Potyka.)

80-48

1-88

—

8-50

— (SiewertvidGeist)

If now the fenons oxide be reckoned as magnesia (FeH) : MgfO » 72 : 40) thtte
analyses giT» leapeetiTely 31*57 and 31*25 magnesia; and the results agree aeerij
with the formula MgCL(3MgK).4BK>*X which requires 31*35 per cent MgK), 62-50 B>0>,
and 7*94 CL (Bammebbezg^s Mineralchemie, p. 254.)

Acid borate of sodinm. See BoBi.T«^ under Bonov, Oxma op(p.64S).

Compoondsof boron with metals. SeeBoBox.

VaUrene. C**H**. — A liquid hydrocarbon, isometie witii oil of
turpentine;, secreted by the Dryabalanopt campkora, and holding in solntioa a aolid
substance, bomeol, or camphor of Bomeo. It is also obtained from essential oil of
valerian, by submitting that oil to fractional distillation, and heating the ftnt portioiis
of the distillate with hydrate of potassium, which takes up Tslerol, while boraeeiM
passes as a distillate. Solid Bomean camphor distilled with phorohotie anbydiide
also yields a liquid hydrocarbon having the composition C'*H**. (See Taiosub, Oa or.)

Bomeene is lighter than water, almost insoluble in that liquid, and smells like od
of turpentine. It turns the plane of polarisation of a luminous ray to the left, but leas
strongly than oil of turpentme. The product obtained ftom oil of valerian boils at
160° C, that from B<nnieo camphor at 165°. Vapour-density 4-60. It absorts hjdro-
chloric add gas, forming a cyrstalline compound. It appears to oxidise iHien left ia
bttdly closed vessels, and when immersed in water, especially in pvesenoe of alkali^ it
appears to be converted into bomeol (Gerhardt, Trait^ lii. 628, 641). (Sm
Dbtabalanops.)

Bomeene from Madder Fusel-oil. — ^The fusel-oil contained in the alcohol ptodueed
by the distillation of madder-sugar, yields liquid products when distilled at tempen-
tuies rising to 230° C, while at hi^«> temperatures laevo-rotatozy bomeol sahhmea.
The former, by digestion with caustic potash, then with chloride of calcium, and repeated
fractional distillation, yields a liquid which boils at 160° C, contains 88*23 per oeot
carbon and 11*81 hydrogen, has a vapour-density » 4*85, and is therefore probably
bomeene. Lsevo-rotatory bomeol (via, i^f,) distalled with phosphoric aahydnde also
yidds a liquid which appears to be bomeene. (Jeanj e.an, Ann. Ch. Pharm. d. 94.)

BOSmoii. Bomeol Meokol, Solid Camphor of Bomeo, iyWH).—TtiB sub-
stance is extracted from the Bryahalanope campAora, being found in cavities in the
trunks of old trees. It is also found in small quantity in moist oil of valerian, being
probably formed by hydration of bomeene.

According to Pierlot (Ann. Ch. Fhys. ix. 291) the crystals found in oil of valeriaa
are not borneol, but valerian-camphor, CH*.

Bomeol is produced artificially oy heating common camphor with alcoholie potash,
its formation being attended, either with evolution of oxygen :

C»*H»«0 + HH) = C"H»«0 + 0 ;
Camphor. Bomeol.

or with simultaneous production of camphie acid :

2C'«H»«0 + H?0 - C"ffH) + (^•E}H>*,
C«mphor. BoniooU Camphie add.

The action takes place slowly at 100° C, more quickly at higher temperatures in sealed
tubes. (Berthelot, Ann. Ch. Phys. [3] Ivi 78.)

Bomeol forms smaJl transparent, colourless, veiv friable crystals or aystaUine firsg-
ments, having an odour like that of common camphor and of pepper, and a hot boniiog
taste. The crystals appear to be regular six-sided prisms belonging to the hexagoaai
system. Their alcohohc solution possesses dextro-rotatoiy power, like that of commoD
camphor. Bextro-rotatonr power of natural bomeol «> 33*40 (Biot), of the aztifi-
cial B= 44*9°. Bomeol is lighter than water, and insoluble in that liquid, but xerj
soluble in aloohd and ether. Melts at 198° C, and boils at 212°, distilUng with-

liquefying: the compound
stroyed by heat.

Lmvo^rotaiory Borneol, — This substance, Vhich is isomeric with oidinaxy bw-
neol, but differs from it in possessing equal but opposite rotatory power, is found in the
alcohol produced by the fermentation of madder-sugar, and is (K>tained by collecting

BORON. 627

the laminiB which crystallise out on standing, or during fractional distillation. It forms
eijBtalline laminse, or a white powder smeUing like pepper and common camphor. It
dissolyes sparingly in water, and when thrown on tne surface of water, spins like
eommon camphor. It dissolves easily in acetic acid, alcohol, and ether. Boiling
nitric acid converts it into IsBvo-rotatory camphor. Distilled with phosphoric anhy-
dride or chloride of zinc^ it yields a hydiocarhon resembling oil of lemon or bergamot
(Jeanjean, Ann. Ch. Fharm. d. 94.)

Syn. with Ebubbscitb and with Tbtbabtiotb.

Native borate of calcium (p. 643).

Aiomio Weight 11. Symbol B. — This element occurs in nature as horie
or boracie add, and in a few minerals, viz. native borax or tincalf boracitef hydro^
boraeUey datoUte^ and botryoUte, and in small quantities in echorl, ajn/rite^ axinite,
and rkodtsite. It never occurs in the free state. Homberg, in 1702, first obtained
boric acid from borax, and anhydrous boric acid was decomposed by Ghay-Lussac and
Th&nard in 1808, and immediately afterwards, by Sir H. Davy, into oxygen and boron.
Boron may be obtained in three different states, viz. amorphous, graphiUiiddt, and
adamoHiine. (Wohler and Deville, Ann. Gh. Phys. [3] lii. 63.)

1. Amorphous Boron. — ^This is the form in which boron was first obtained.
Gay-Lussac and Th^nard prepared it by igniting boric anhydride (vitrefied boric acid)
in a tube with an equal weight of potassium in small pieces, then boiling the fiised
mass with very dilute hydrochloric acid, washing with water, and drying. This pro-
cess yields, however, but a small product, as it is difi&cult to deprive the boric acid of
all its water, and the remaining quantity oxidises part of the potassium, with violent com-
bustion, causing part of the mass to be projected. According to E. D. Thomson (Phil.
Mag. [3] x. 419), this inconvenience may be obviated by drying the boric anhydride
as completely as possible, mixing it in the state of coarse powder, with twice its
weight of potassium, freed as completely as possible from the crust of hydrate which
general^ adheres to it, and gradually heating the mixture to redness in a glass tube
over a lamp. Wohler and Deville mix 60 grammes of sodium in small pieces with
100 grammes of finely powdered boric ai^ydride in an iron crucible, and cover
the mixture with about 30 grammes of pulverised and previously ignited chloride of
sodium. The crucible is then quicklv heated to redness, whereupon a violent reaction
takes place, and the whole becomes liquid. It is careftilly stirred with an iron rod
till no more fr«e sodium or unfused chloride of sodium can be seen, then carefhUy
poured into water acidulated with hydrochloric add, and washed and dried as above.
As the amorphous boron is very apt to run through the filter when washed witb pure
water, it is 1>B6t to wash with water containing sal-ammoniac, and then remove that
salt by means of alcohol. — ^Another mode of preparing amorphous boron is that of
Berz^us, which consists in decomposing perfectly dr^^ borofluoride of potassium bv
heating it with an equal weight of metallic potassium in an iron tube closed at both
ends. The mixture is first heated merely to the melting point of potassium, then well
stirred with an iron rod, and afterwards heated to redness. The decomposition takes
place without explosion, and the boron ia afterwards separated from the fiuoride of
potassium, with which it is mixed, by digestion and washing with water containing
sal-ammoniac, the latter being finally removed by alcohol If too little potassium has
been taken to produce complete deoompositipn, the washing is rendered difficult by
the remaining borofiuoride of potassium, which has but litue solubility. Amorphous
boron is also formed, together with the other two varieties, in the modes of preparation
presently to be described.

Amorphous boron is a dark-brown or greenish-brown powder, opaque, destitute of
taste and smell, and stains the fingers strongly. It is a non-conductor of electridty.
In vacuo, or in gases with which it does not unite, it may be raised even to a white
heat without melting, or subliming, or undergoing any alteration, excepting that it
becomes so dense that it sinks rapidly in oil of vitrioL In the uniffnited state, it dis-
solves, to a very slight extent, in pure water, imparting its colour; in water containing
adds or salts it is insoluble, and indeed such substances predpitate it from its aqueous
solution.

Amorphous boron does not oxidise in the air or in oxygen gas at ordinary tempera-
tures^ but at about 300^ 0. it bums in the air with a reddish light, and in oxysen g^s
with dazzling brightness ; the combustion is in both cases attended with vivid emis-
sion of sparlu, and in oxygen gas, according to Berzelius, a faint greenish fiame is ob-
served. The product is boric oxide or anhydride, B^O', the onl^ known oxide of boron,
which melts on the surface of the boron and partlv protects it from further action.
In atmospheric air, according to WoHler and Deville, a small quantity, of nitride of
boron is formed at the same time.

8B 2

628 BORON.

Amorphoos boron does not decompose water, even at the boiling heat« bat it nat3alj
decomposes strong sulphniic acid when heated with it, and nitric add, erm when
bnt slightly concentrated, in the cold, the product in each case being boric add. At a
red heat» it decomposes the carbonates, sulphites, snlphates, nitrites, and nitntei of
the alkali-metals, an alkaline borate being formed, and carbon, snlphnr, or nitrogen
set firee. Thb decomposition is sometimes attended with incandescence and, in the
case of nitre, with explosion. It also decomposes many metallic oxides at a nd heat,
forming a borate, if uie oxide is in excess. Heated with hydrate of potasshm, it
eliminates hydrogen, and forms borate of potawmnm. It likewiM reduces masj
metallic chlorides and sulphides, e.^. chloride of lead, chloride of silver, and solphide
of lead at a red heat, chloride of boron being formed and escaping as gas -(Wdkler
and Devi lie). It precipitates metallic gold from a solution of the ch&ride. 'When
strongly ignited in a coiront of nitrogen gas, it is converted into white nitride of boron.
Heated nearly to redness in a current of nitric oxide gas, it bums brilliantly, ftnmog
boric anhydride and nitride of boron. It does not decompose nitrous oxide. (Wohler
and DeviUe).

By ignition with aluminium, amorphous boron may be converted into tiie two other
modimcations, which remain behind on dissolving out the aluminium by hydrodilorie
add.

Graphitotdal Boron, — ^This variety of boron is obtained : — 1. Bj^pasnoggiseou
chloride of boron for some time over aluminium in the state of fudon. Tas metal
takes up but a small quantity of boron ; but on breaking it, the boron is finmd on tha
fractured surfiice in copper-coloured crystalline Uuninte, like graphite in cist-iion;
they may be separated by dissolving out the aluminium with hydrochloric acid.—
2. By heating 8 pts. of borofluoride of potasdum and 5 pts. of alumininm with a itu
of 9 pts. chloride of potassium and 7 pts. chloride of sodium to the melting nrint of
sUver, in a porcelain crudble, and treating the half frised metallic mass fonsd is tha
midst of the slaff, first with hydrochloric tiien with hydrofluoric add. Boron tiien re-
mains in small bUckish-grey crystalline scales. — 3. By ftising a mixture of 15 pta boiie
anhydride, 10 pts. fluor-spar, and 2 pts. aluminium ; or by frising aluminium with borie
anhydride, or better with ftised borax and cryolite, and a flux of chloride of potaaanm
and chloride of sodium. A large excess of aluminium, howcTer, is required to obtain
but a small quantity of boron.

Graphitoidal boron has a semi-metallic lustro, like graphite or cryBtaHine ferric
oxide, but with a distinct tinge of copper-red. When well crystallised, it forms thin ox-
sided tablets belonging to the hexagonal system ; but it is more generaUy obtained ai
a reddish-grey, micaceous powder composed of fine crystalline lamine. It is peifeetlj
opaque. When heated to redness in the air, it does not bum or undergo any sppucnt
alteration. It does not di&jolve in adds or in alkalis, but appears to be oonTotcd
into boric add by the long-continued action of nitric add. (W ohler and Deville.)

Adamantine or Diamond ^oron.-^This is not, strictly speaking, a fonn of
puro boron ; at least, as hitherto obtained, it always contains carbon and sometimes
aluminium. To prepare it, 80 grammes of alumimum in lumps aro heated with lUO
grammes of boric anhydride to a temperature at which nickel fuses readily. The
mixturo is introduced into a crudble of compact charcoal fitted with a chareoal
cover and placed within a hessian or black-lead cracible, the intermediate space being
filled with charcoal-powder, and the cov^r fastened on with refractory luting; and the
whole is exposed for fire or dx hours to the strongest heat of an air-furnace, hating ft
tall chimney and fed with a mixture of coke and coaL On breaking the cracible
after cooling, two layers are found, one glassy, consisting of boric anhydride and
alumina, the other a metallic iron-grey mass of aluminium, penetrated throng^oat
with crystalline boron. The alumimum is dissolved out by strong soda-ley, iron bj
hot hydrochloric add, and the residue is treated with a hot mixture of mtric and
hydrofluoric acid, to remove silicinm. The crystals of diamond boron thus fiur purified
are still mixed with graphitoidal boron and crystalline laminae of alumina ; the ibm<T,
being light, may be separated by levigation; tiie latter only by careful mecham'cil
selection.

Adamantine boron forms quadratic octahedrons, in which the principal aria is to
the secondary axes as 0*577: 1. The crystals vary in colour, from a scaroehrpw^
ceptible honey-yellow to deep garnet-red; sometimes they are so deeply coloured, pro-
bably by amorphous boron, that they appear black. In lustre and refracting power,
they are nearly equal to the diamond. Their specific gravity is 2-63. They are ex-
tremely hard, always sufi&ciently so to scratch corundum with facility, and eome
crystals are nearly as hard as diamond itself. The hardest are obtained by repeatedly
exposing aluminium to the action of boric uihydride at a temperature high eoougfa to
cause the anhydride to vohitilise very quickly.

BORON: BROMIDE— CHLORIDE. 629

Adamantine boron does not ftise, eren at the heat of the oxyhjdroeen blowpipe, tind
vithatands the action of oxygen even when yeiy strongly heated ; but it is slightly
oxidised at the temperatnre at which the diamond burns, a film of boric anhydride
being then fonned, which stops fiirther oxidation. Heated on platinmn-foil before the
blowpipe, it forms a fiisible bbride of platinum. It is not attacked by acids at any
tempmtore, but when heated to redness with add sulphate of potassium, it is oon-
Tert«d into boric acid. It is not attacked by a strong boiling solution of caustic soda,
but is slowly dissolved by hydrate or carbonate of s^um at a red heat Nitre does
not appear to act upon it at any temperature.

Boron unites, as already observed, with oxygen and with nitrogen, also with
chlorine, bromine, fluorine, and sulphur. With metals it does not, for the most part,
unite rcttdily; but borides of palladium and platinum are known. The platmum
compound is very Visible, so that boron, in either of its modifications, if ignited on
platinum-foil before the blowpipe, instantly perforates the platinum. (Wohler and
Deville.)

Boron in all its combinations appears to be triatomic; the chloride being BCl', the
oxide B«0«, the hydrate (boric acid) H*BO», &c

B or. BBr'.— Discoveredby Pogffiale in 1846 (Compt rend.
xxiL 124), but first obtained pure by Wohler and Deyille (Ann. Ch. Phys. [3] lii
89.) It IS produced by the action of bromine on amoiphous boron, or on boric anhy-
dride in presence of charcouL The beet way of preparing it is to pass bromine-vapour
over heated amorphoos boron, previously well dried in a current of hydrogen ; then
digest the product for some time with metallic mercury, to remove excess of bromine,
and distiL

Pure bromide of boron is a colourless mobile liquid, of specific gravity 2'69, vola-
tilising readily at ordinaiy temperatures, in colourless, pungent vapours, and boiling
under the ordmary atmospheric pressure, at 90^ C. Vapour-density (referred to air),
by experiment, 8*78 ; by calculation (2 vol.) «« 8*7. It fumes in moist air, and is in-
stantly decomposed bv water, with formation of boric and hvdrobromic acids. With
dry ammonia-gas, it iorms a white pulverulent substance, which is converted by water
into bromide and borate of ammonium : possibly thus :

BBr».4NH" + 2H=0 « 8NH*Br + NH«BO».

Or« BCl*. — ^First prepared bj Berzelius (Pogg. Ann,
ii. 147X afterwards by Dumas (Ann. Ch. Phys. [2] xxxi. 436; xxxiii 376), more
exactly inv<«tigated by Wohler and Deville (ilnd. [31 lii. 88). It is formed by the
direct combination of chlorine and boron, which takes place at ordinary temperatures,
or at a gentle heat ; also by heating boron in hydrocnloric acid gas, or a mixture of
boric anhydride and charcoal in chlorine gas, and by the action of boron at a red heat
on chloride of mercury, lead, or silver.

To prepare it, amorphous boron, loosely packed in a glass tube, is first freed from
moisture by passing dry hydrogen over it at a gentle heat ; the tube is then left open
for a few seconds, to allow the hydrogen to escape ; after which, dry chlorine gas is
passed through the tube, the action being assisted if necessary, by gentljr heating the
tube in a combustion furnace. Combination then takes place, attended with evolution
of light and heat ; and the vapours of chloride of boron are passed through a caout*
cfaouc connecting-tube into a x -shaped tube, the two upper arms of which are sur-
rounded with ice and salt, while the lower arm conveys the condensed liquid into a
receiver placed below. The product may be freed from excess of chlorine by digestion
with mercury. A small quantity of oxychloride of boron is generally formed at the
same time, by the action of a little air or moisture left in the apparatus ; but it con-
densea in the cooler part of the oombuation-tube« The chloride of boron may be freed
from excess of chlonne by digestion with merciugr.

When the vapour' of cnlonde of boron is mixed with hydrogen, as when it is pro-
duced by heating boron in hydrochloric acid gas, or with carinmic oxide, as when
produced by the action of chlorine on a hot mixture of boric anhydride and charcoal,
it is very difficult to condense ; indeed, chloride of boron was ori^ally regarded as a
gas at ordinaiy temperatures, until Wohler and Deville obtained it in a state of purity
by the process above described.

Pure chloride of boron is a colourless, mobile, strongly refracting liquid^, having a
specific gravity of 1*36 at 17° C. (? 7^) ; it expands very perceptibly by a rise of l^or
2° of temperature. It boils at 17° C. Vapour-density, by experiment « 4*06—4*08;
by calculation (2 voL) ■■ 4*07. It fumes m damp air, and is quickly decomposed by
water, yielding boric and hydrochloric acids. With alcohol, it forms, with great rise
of temperature, hydrochlonc acid and borate of ethyl : similar reactions with methylio
and amylie alcohols.

88 3

630 BORON : DETECTION AND ESTIMATION.

AmmofUo-ckloride of Boron^ 3NH'.2BG1', is formed, with great erolntioa of heat,
when dry ammonia-gas is passed oyer chloride of boron. It is a white, findj crys-
talline powder, which sublimes unaltered when heated alone, though not so easily as
sal-ammoniac It does not fume in the air, but is decomposed by water, yielding bocie
acid, chloride of ammoniom, and hydrochloric acid :

2BC1».3NH« + 6H*0 « 2H"B0« + 3NHK31 + 3HCL

When the vapour of this compound, mixed with ammonia-gas, is passed through a
red-hot tube, nitride of boron is produced.

BO&OWv CB&OBOCTJLWSDB OV. See Ctakoosit, Chlobidb of.

BOBOVf SBTBOTZOV AMS B8TZMATXOV OV« Boron almost always
occurs in the form of boric acid, and therefore the reactions by whidi it is detected
are best considered in detail in connection with that acid (see page 639). When the
acid is in the free state, it is easily recognised by the green colour which it imparts to
flame, especially to an alcohol flame, and by its peculiar action on turmeric paper. If
the acid is in combination with a base, the compound must first be decomposed in tiie
state of powder by sulphuric acid, and the boric acid extracted with alcohoL KatiTo
borates not decomposible by sulphuric add, must be ftised with potash, and then
digested with alcohol and sulphuric add. Another method of detecting boron in
minerals is to mix the pulverised substance with 4 pta. of a flux containing 1 pt
pounded fluorspar and 4} pts. add sulphate of potassimn, made into a paste with a
utde water, and heat the mixture on a platinum wire in the inner blowpipe flamcL
As the mass melts, fluoride of boron is given off, and imparts a yellow-green ooloor to
the outer flame. If the <}uantity of boron present is small, this appearance lasts only fiv
a few seconds, ceasing, m fact, as soon as the fluoride of boron is completely volatilised.

The green colour imparted to flame is a very delicate test for boron. Before
applying it, however, care must be taken to ensure the complete absence of copper, as
the salts of this metal impart a very bright green colour to flune. C^tain musise-
compounds also colour flames green, as when hydrochloric add is dropped into an
alcohol flame ; but the green colour thus produced has a dedded bluish tinge, which
distinguishes it from that produced by boron. Lastly, phosphates moistened with
sulphuric add, also give a funt green colour to the outer blowpipe flame.

Quantitative Estimation. — ^The exact estimation of boron presents considerable
difficulties, as all borates are more or less soluble in water or in alcohol, and boric add
cannot be heated without loss in contact with water. The best mode of direct esti-
mation, originally proposed by Berzelius, and perfected by Stromeyer (Ann. Ch.
Pharm. c. 82), is to precipitate the boron as borofluoride of potassium, whidi is quite
insoluble in alcohol of a certain strength. This mode of predpitation, however, is
directlv applicable only when the boron exists in solution as borate of potassium : any
other bases present must flrst be separated. Borates of the alkaline-earth-metals,
earth-metals, or heaTT metals, are fused with carbonate of potasdum ; and the mass is
digested in water, which takes up nothing but borate of potasdum, except perhi^ a
trace of magnesia. Borate of sodium is treated with alcohol and sulphuric add ; the
alcoholic liquid filtered from the sulphate of sodium, is mixed with excess of potash
free from siHcic and carbonic acids ; and the alcohol is evaporated. The alkaline bonte
of potassium obtained in dther case, is now to be saturated with pure hydrofluoric
add, and the liquid evaporated to drjrness in a silver or platinum vessel ; the dry
saline mass is macerated with a solution of acetate of potassium (1 pt. of the salt to
4 pts. water) ; the undissolved borofiuoride of potassium is collected on a weighed filter
supported on a gutta-percha funnel, and washed, first with the solution of acetate of
potassium, which removes chloride, phosphate, and sulphate of potassium, likewise
sodium-salts though slowly, and afterwards with alcohol of 84 per cent Trailes (spe-
cific gravity 0*8526), then dried at 100° G. and wdghed. 100 parts of the borofluonde
correspond to 27*78 boric anhydride, gr 9*06 boron.

To ascertain whether the precipitate is pure, it is dissolved in boiling water, whidi
leaves behind anv traces of magnesia that may be present, and the solution is treated
with ammonia, which predpitates silica if present : the predpitate may then be washed,
flrst with acetate of potassium, then with alcohol, and its weight ascertained.

The quantity of free boric acid in an aqueous or alcoholic solution, cannot be deter-
mined by evaporation to dryness, because a considerable quantity of the add goes off
with the aqueous or alcoholic vapours : even the presence of excess of lead-oxide,
baiyta, or bade phosphate of sodium, does not completely prevent this evaporation.
Ammonia prevents the volatilisation to a greater extent than either of these substances,
but it does not quite prevent loss. The only exact mode of determining boric add by
evaporation, is to supersaturate the liquid with a Imown weight of pure fbsed carbonate
of sodium (about 2 pts. of the carbonate to 1 pt of add supposed to be mesent) ; then
evaporate to diyness, and ignite the residue in a covered crudble. The amount of

BORON: DETECTION AND ESTIMATION. 631

eailKmio anhydride in the residue is then to be determined by the method given under
AuL&UMBTBT (p. 149), and deducting this, together with the known weight of soda
contained in the carbonate added, from the total weight of the residne, the remainder
is the quantity of boric anhydride present.

Boron in borates may be estimated indirectly in several ways. The best method is
to digest a weighed quantitjr of the pnlverised compound in a capacious pUtinum
cnicibie, with hydrofluoric acid, then gradually add strong sulphuric acid, and heat
the mixture, gently at first, and afterwards to redness, tiU the excess of sulphuric acid
is expelled. The boron is then completely driven off as fluoride, and the bases remain
in the form of sulphates. If only one base is present, its quantity is easily calculated
from the weight of the residue. If two bases are present, e,a. potash and soda, the
amount of sulphuric acid in the residue must be ascertained ; the quantities of the two
bases may then be found by the method given under Imdibect Akaxtsis (p. 224). BT
more than two bases are present, they must be separated by the usual methods. The
weiffht of the bases deducted from that of the original substance, gives the amount of
bone anhvdride.

Instead of driving off the boron as fluoride, it may be volatilised as borate of ethyl,
by treating the pidveiised borate with strong sulphuric acid and alcohol Or the
boric acid set free by the action of sulphuric acid, may be dissolved out by alcohol
and separated by flltration ; but this last method is applicable only when the resulting
sulphates are completely insoluble in alcohol.

£orie add combined with potash or with soda, may be estimated volumetric all v
by means of a standard solution of sulphuric acid. The solution is coloured witj^
tincture of litmus, and the sulphuric acid is cautiously added from a burette, till the
wine-red colour flrst produced by the liberation of the boric acid, changes to the bright
red which indicates the presence of free sulphuric acid : this takes place as soon as
the quanti^ of sulphuric acid (H^O*) amounts to 1 atw for 2 at of potash or soda
(KHO or MaHO). Hence the amount of the base is found, and this deducted from
the total weight of the diy salt, gives the boric acid.

Separation of Boron from other Elements. — ^When boric acid is in com-
bination with several bases, it is best to estimate the amount of these bases at once,
and determine the boric acid (or anhydride) by difference. From the metals of the
first group, copper f for example, boron is easily separated by sulphuretted hydrogen ; from
trvm, and others of the second group, by sulphide of ammonium. From bmum it is
separated by sulphuric add ; from atrontium and calcium, by sulphuric add and alcohol ;
from maffnesium^ by ammonia and phosphate of sodium : the predpitate in this last
case generally contains a small quantity of boric add.

The separation of boric acid from all these bases may likewise be effected by fbsion
with alkaline carbonates ; in the case of magnesia, carbonate of potassium must be
used, because soda forms with magnesia an insoluble compound.

JS^ulpknric acid is easily separated from boric add by predpitation with chloride of
barium ; J^droehloriCy hydrooromiCf and hydriodic adds, hj adding nitrate of silver to
the solution addulated with nitric add ; phosphoric acid, by ammonia and sulphate
of magnesium.

The estimation of boron in presence of fluorine is difficult. Metallic borofluorides
are analysed by heating them with sulphuric acid, whereby fluoride of boron and
hydrofluoric acid are driven ofl^ and the metal remains as sulphate, from the weight
ox which its quantitj may be determined, and hence the amount of the boron and
fluorine together. If the compound contains water of ciystallisation, it must be de-
j^ermined hj mixing the compound with 6 pts. of oxide of lead, covering the mixture
in a retort with a layer of oxide of lead, and exposing it to a heat short of redness.
The loss of weight gives the water.

In a mixture of a borate with a fluoride, it is impossible to determine either the
boron or the fluorine exactly. By dissolving the compound in excess of nitric acid,
and adding excess of carbonate of calcium, £e fluorine is predpitated as fluoride of
ealcium, but not completely, probably because a borofluoride is formed.

The estimation of boron in silicates is likewise difficult. If the silicate is decom-
posed by adds, like datolite or botryolite, it is flnely pulverised, heated in a corked
flask with hydrochloric acid, at last nearly to boiling ; the thick jelly is then diluted
with water and Altered ; the filtrate supersaturated with ammonia, which separates
alumina ; oxalic acid is added to predpitate lime ; and the filtrate, which now contains
nothing but boric add in combination with ammonia, is evaporated in a platinum
capsule over the water-bath, with frequent addition of ammonia. The dry residue is
then gradually heated to redness in a covered platinum crudble, whereupon boric anhy-
dride renuiins mixed with a little silica. The boric anhydride is afterwards dissolved
out by water, and the residual silica weighed. The result is not quite exacts as a little
boric add goes off even in presence of excess of ammonia, but the loss is not considerable.

ss 4

632 BORON: FLUORIDE.

In flUicatefl not deoomposible by acids, boron is estimated by heating the pQlTerued
mineral, first witii hydrofluoric and then with solphoric add, vhereby the Won ud
silieinm are expelled as fluorides. The bases then remain as sulphates, ind ue de-
termined by the ordinary methods. In another portion of the minenl, the ailiet is
determined by fiision with a mixture of the carbonates of potassium and lodiiun,
treatment of the residue with hydrochloric acid, eyaporation to dryness, digestioa of
the residue in acidulated water, filtration, and washing, — ^whereupon the silica vnnaiu
on the filter in a state of purity, and may be i^ted and wcdg^ed. The bsses and tibe
silica haying been thus determined, the bone anhydride is found by difiereno^ the
result being of course affected by all the errors in the seyeral detenninatioDs.
(H. Rose, Analyt CheuL iL 734.)

The estimation of boron in orgarUe com^^oundt, is generally eflbcted by mixing the
compound with ammonia in a capacious platinum crucible^ then eyaporating and
igniting the residue. This method, according to Ebelmen, always inyoWes a loss of it
least 2 per cent, of boron, and that loss may eyen amount to 4 per cent. A better
method might perhaps be to heat the compound with nitric acid in a sealed tobe, ac-
cording to Canus's method (p. 247) : the boron would thereby be conyerted into
boric acid, and might then be estimated by any of the methods aboye giyen.

Atomic Weiaht of Boron, — ^The earlier experiments of Gay-LussaeandTh^naid,
Dayy, and Berzelius, in which the atomic weight of boron was estimated by the amount
of oxygen absorbed in its combustion, did not lead to concordant results. Beiieliu
afterwards determined its yalue from the amount of water in crystallised borax, vfaieh
in three experiments, he found to be 47*1 per cent. Now supposing the fonnnlaof the
salt to be NaK).2B*0* + lOHK), and that the atomic weight of sodium is 23, this
result makes the atomic weight of boron equal to 11. Experiments by Berille, re-
ported by Dumas (Ann. Ch. Phys. [3] ly. 129), on the proportion of chloiine in
chloride of boron, gaye, on the supposition that the formula of the chloride is BGP,
the two results B = 11*0 and B «» 10*6. Similar experiments with bromide of Iraron
BBr^ gaye B ^ 11 -0. This number appears therefore to haye the greatest weight of
evidence in its fayour. If the formula of chloride of boron were Bd", the atomic
weight of boron would be 7*3.

BOSOW, F&VOmZDB OV. BF*.— Disooyered by Gay-Lussac and Th^nard, in
1810. It is obtained : 1. By the action of boric anhydride on fluoride of calcinm at
high temperatures :

6CaF + 7BH)« - 3(Ca«0.2B«0^ + 2BP".

An intimate mixture of 2 pts. fluorspar and 1 pt. yitreous boric anhydride, is intro-
duced into a gun-barrel closed at one end, and neated to whiteness in a furnace vith
good draught, and the gas which escapes is receiyed oyer mercniy : borate of caldam
tJien remains behind. — 2. By the action of hydrofluoric acid on boric acid or aahj-
dride, yiz. by heating a mixture of 1 pt boric anhydride (or 2 pts. fiosed bocax]^ and
2 pts. fluor spar, with 12 pts. oil of yitriol, in a glass yessel:

6CaF + B«0« + 3H«0« - 8Ca«80« + 8BP0 + 2BP.

This method is easier than the former, but the gas which it yields is not quite noM,
as it contains a little fluoride of silicium, resulting from decomposition of the glan;
moreoyer part of the fluoride of boron is conyerted by the water into boric and hydro-
fluoric acids.

Fluoride of boron is a colourless gas, of pungent sufibcating odour, like Uiat of
fluoride of silicium. Speciflc grayity » 2*37 (Bayy); 2*31 (Dumas); and bj cal-
culation :

11 + 8 . 18*7 ^^^o« ««*.
5 X 0*0693 « 2*29

It reddens litmus, fhmes in damp air, and chars organic bodies like snlphuric add.
It does not corrode glass. It is not decomposed by a red heat» or by the elediie
spark.

Water absorbs about 700 times its yolume of this gas, with great eyolntion of heat
and increase of bulk, forming an oily liquid of speciflc grayity 1*77, which when
boiled, giyes off \ of the dissolyed gas, and leayes a residue consisting of BK)'.6flP,
or 2BF'.3HK), which may be distill^ without alteration. Water incompletely sata-
rated with fluoride of boron, deposits boric acid on cooling, or after standmg fiw some
time, while fluoride of boron and hydrogen HF.BF*, remains in solution.

Strong sulphwric acid absorbs 60 times its yolume of gaseous fluoride of boron, fonn-
ing a yiscid liquid, which deposits boric add when mixed with water.

Potassiumf sodium^ and the alkaline earth-metals, heated in fluoride of boron, be-
come coyered with a blackish crust, which bursts at a red hoat^ the metal then boning

BORON: FLUORIDE. 633

vith bright incandescence! and forming a metallic boroflnoride, vith separation of
boron. Iron does not act upon the gas, even at a bright-red heat. Quick lime absorbs
fluoride of boron readily when heated, forming a ftisible mixture of fluoride and borate
of caldum,

Ihy ammonia aas forms with an equal volume of fluoride of boron, a white, opaque,
solid compound, X^*3F', which volatilises undeoomposed, and is converted by water
into borofluoride and borate of ammonium. By the ^irther action of ammonia on this
body, two liquid compounds, 2NH*.BF*, and 3NH».BF*, are formed; when exposed to
the air or heated, they give off ammonia and reproduce the solid compound.

According to Kuhlmann, fluoride of boron unites with nitric oxide, nitrous add,
peroxide of nitrogen, and nitric acid.

Slnoberio Aeid« HBO'.SHF. — ^This compound, discoyered by Ghiy>Lussac and
Th^nard, is obtained by saturating water with gaseous fluoride of boron, the vessel
being cooled with ice, and the gas-delivery-tube made to dip under mercuiy bdow the
water, as otherwise the rapid absorption would cause the liquid to run back into the
generating vessel The saturated solution has a spedfle gravity of 1*77, and is nearly
pure ftuoboric anhydride, B«0«.6HF, or hydrate of boric fluoride, 2BF*.3H*0 (Gmelipji
bi-hydrofluate of boric add, BO^.SHF, Handbook, u. 363). On heating it, one-fifth
of the absorbed fluoride of boron goes off, and there remains a liquid of spedfic gravity
1-684, which is fluoboric add, HK).B«0».6HF, or HB0«.3HF.

An easier mode of preparing this acid is to dissolve boric acid or anhydride in hy^
drofluoric add contained in a platinum crucible externally cooled, avoiding an excess
of boric add, then evaporate over the water-bath, gently boil the remaining liquid
in the covered crudble, till the vapours form a thick fume in the air, and leave the
liouid to cool over sulphuric acid. It maj also be obtained by fusing an intimate
mixture of 10 pts. fluorspar and 8^ crystaUiaed borax, pulverising the ii^ed mass, and
/liatilling it with 16| pts. strong sulphuric add. The product thus obtained generally
Gontaina a little silica derived £rom the distillation-verad.

Fluoboric add is an oily liquid, like oil of vitriol, fumes in the air, boils at a tem-
perature above 100^ C, and distils without alteration. It is highly caustic, chars
organic bodies, and converts alcohol into ether. By dilution with water, it is decom-
posed, one-fourth of the boric acid being separated, and a solution of hydrofluoboric acid
remaining:

4{HBO«.3HF) - HBO« = 8HBF* + 6H«0.

Fluoboric add forms salta, having the general formula MB0'.3MF. They are pro-
duced by the direct action of the acid on the bases, or by dissolving the corresponding
borates and fluorides in the proper proportions, and leaving the solution to evaporate.
But few of them have been examined.

The iodium^alt, KaB0'.3NaF + } aq, ciystallises in small rectangular prisms,
having their terminal faces obliquely truncated ; they have an alkaline reaction, give
off their water at 40^ C, and melt at a higher temperature. The fused salt, if quickly
eooled, solidifies to a dear g^ass ; but by alow coohng, it becomes turbid, fiK>m separa-
tion of fluoride of sodium, which remains undissolve on treating the mass with cold
water, whereas boiling water dissolves the whole, reproducing the original salt.

Another fiuoborate of sodium, NaHB*0^6NaF+ lOaq, is produced by slowly eva-
porating a solution of 1 at. borax and 6 at fluoride of sodium. It cn^stallises in small
rectangular four-sided prisms, which become turbid at 40^ C. from loss of water, and
behave like the preceding when mdt^ and slowly cooled. (Handw. d. Chem. 2** Aufl.
iL [2] 279.)

BSfdroflnoborie Aeld. HBF^^BF'.HF. — Obtained by passing gaseous fluoride
of boron into water, till the liquid is strongly add, and exposing it to a low tempe*
rature. Boric acid then separates, and hydrofluoboric add remains in solution :

4BF» + 2H*0 » 8BHF* + HBO«.

A similar solution is obtained by dissolving crybtallised boric add to saturation in
moderately strong hydrofluoric acid artificially cooled.

Hydrofluoboric acid is known only in the state of dilute solution. It is decomposed
by concentration, yielding hydrofluoric and fluoboric acids :

BHF* + 2H«0 - HF + HBO^.SHF.

In the dilute state, it does not attack glass ; but if it be concentrated in a glass vessel,
the glass becomes corroded, from separation of hydrofluoric acid ; if, however, boric
add be added during the concentration, so as to form fluoboric acid, no corrosion of
the glass takes place.

Boro/luorides. — These salts, whose composition is expressed by the general
formula, MBF' or MF JtF*, are formed by the action of gaseous fluoride of boron or

634 BORON: FLUORIDE.

aqneoiu flnoboric acid on metallic fluorides ; by the action of metallie oxides on hjdro-
fluoboric acid ; or by dissolving a metallic fluoride, together with boric acid, in aqueous
hydroflnoric add; sometimes also by merely bringing a fluoride in contact vith
boric acid, the liquid then becomixig alkaline if previously neutral, or even if acid.

Most borofluorides are soluble in water, and are obtained in the ayrtalline stite
by evaporating their aqueous solutions. At a red heat, they are resolved into fluoride
of boron and metallic fluoride. Distilled with sulphuric acid, they give off gaseous
fluoride of boron and aqueous hydrofluoboric acid. They are fixr the meet part not
decomposed by heating with alkalis or alkaline carbonates.

Borofiuoride ofAlunUnium, crystallisee by slow evaporation from a solution of hydrate
of aluminium in excess of hydrofluoboric acid; the crystals dissolve in water only
when free add is present. On mixing a solution of chloride of aluminium witJi boio-
fluoride of sodium, a basic borofluoride of aluminium is predpitated, which, at a red
heat, is resolved into flnoboric add and borate of aluminium.

Borofiuoride of Ammonium^ NH^F.BF*, is obtained by subliming a mixture of the
potassium-salt with sal-ammoniac, or more easily by dissolving boric add in aqneoos
fluoride of ammonium, ammonia being then evolved :

4NH*F + H»BO» « NH*F.BF« + 3H«0 + 3NH«.

It crystallises by evaporation in six-dded prisms with dihedral summits ; dissolves
readily in water, somewhat less in alcohol ; reddens litmus ; does not attack glass ;
dissolves in aqueous ammonia, and OTstallises out unaltered ; sublimes when heated.

Borofluoride of Barium, 2BaBF'.HH). — ^Prepared by saturating hydrofluoboric add
with carbonate of l)arium, avoiding an excess, otherwise fluoride Of barium and bone
add are produced. OrystaUises from a warm solution in long needles ; by alow evapo-
ration in a warm atmosphere, in smooth rectangular prisms, often amjDged in steps
like common salt. Has an add reaction ; tastes like barium-salts in general ; dis-
solves readily in water ; deliquesces in moist air. Alcohol decomposes it, dissolving an
add salt, and separating a white powder. The crystals effloresce at 40*^ C. and decom-
pose at a higher temperature.

Borofluonde of Calcium^ — A solution of carbonate of caldum in hydrofluoric add,
deposits on evaporation, a gelatinous mass, which dries up to a white powder, reddens
litmus, and is decomposed by water, with separation of a basic salt

Borofluoride of Copper, CuBF^. — Light blue needles obtained by decomposing the
barium-salt with sulphate of copper, and evaporating the flltrate. •

Borofluoride of Lead, PbBF^ — Prepared like the barium-salt, and crystallises with
difficulty by spontaneous evaporation, in four-sided prisms ; from the solution evi^-
rated to a syrup, in long prisms. Has a sweetish taste, with sour astringent aftertaste.
Partially dissolved by water and by alcohoL Heated with oxide of lea^ it is said to
yield an easily fiisible oxy borofluoride, whose aqueous solution is rendered turbid bj
the carbonic add in the air.

Borofluoride of Lithium, LiBF^ — ^Prepared like the copper-salt, and separates by
evaporation at 40° C. in large prismatic czystals, which have a rather bitter and add
taste, and deliquesce in the air, sparingly soluble rhombohedral crystaia then sepa-
rating, which have not been farther examined.

Borofluoride of Magnesium, — Easily soluble; ciystallises in large prisms ; tastes
bitter.

Borofluoride of Potassium KBF^ — Formed like the ammonium-salt^ by adding
boric add to aqueous fluoride of potassium. It may be prepared by dissolving 2 at
(124 pte.), of crystaUised boric add, and 1 at (138 pts.) carbonate of potassium in excess
of hydrofluoric acid, or by adding a soluble potassium-salt to hydrofluoric add ; it
then separates as a transparent gelatinous predpitate, which appears iridescent hj
reflected light while suspended in the liquid, and dries up to a white powder. It
dissolves in 70 pts. of cold, and in a smaller quanti^ of hot water, and arstallisefl
from the solution in anhydrous, shining, six-sided pnsms. It has a bittenah taste,
and does not redden litmus. Alkalis do not dissolve it more readily than pun
water. Ammonia does not alter it, unless the solution contains silica, in which case a
predpitate is formed. It dissolves in boiling alcohol. When heated, it first melts,
then gives ofi* fluoride of boron, and if not quite dry, likewise flnoboric add; and after
prolonged exposure to a strong heat, leaves fluoriae of potasdunLp Strong sulphuric
add decomposes it but slowly, even with the aid of heat.

Borofluoride of Sodium, NaBF^ forms short four-sided rectangular prisms, very
soluble in water, less in* alcohol ; has a rather bitter and acid taste, and reddens
litmus. The crystals are anhydrous, melt below a red heat, but require strong and
prolonged ignition to decompose them completely into fluoride of boron and fluoride
of sodium.

Borofluoride of Yittrum dissolves only in water containing free add. It is

BORON: IODIDE — OXIDE. 635

obtamed in crjsUls bj dissolying yttnA in excess of hjdroflnoboric acid, and
eraporating.

Borofiuoride of Zine, ZnBF^. — Zinc diflsolres in hydioflaoborie acid with erolntion
of hydrogen. The solution evaporated to a syrup, solidifies at low temperatures to a
ddiqiiesoent mass.

BOSOWf XOBIBB OV> Kot yet obtained in the pure state. Iodine and boron
strongly heated together, form a product which appears to be an oxyiodide (Wohler
andDeTille). Boron does not decompose iodide of silyer, even at temperatures
aboTethe meltinff point of the metal.

According to Lifflis, a mixture of boric anhydride and charcoal heated in iodine-
raponr, yields a ydlow sublimate, which has not been examined.

MOMOWf VZTBZBB OV. BN. — This compound was disoorered by Balmain
(FhiL Mag. [3| xxi. 170 : xxiL 467 ; xxiii. 71 ; xxiv. 191), who at first regarded it aa
capable of uniting with metals and forming compounds analogous to the cyanides ;
but afterwards found that all these supposed metallic compounds were one and the
same substance, via. nitride of boron without any appreciable amount of metal.
This conclusion has been confirmed by Marignac (Ann. Ch. Pharm. l-im'-r 247).
Balmain obtained this substance Jiy heating boric anhydride with cyanide of potassium
or cyanide of zinc, or with cyanide of mercuiy and sulphur. It has since been more
completely investigated by Wo hie r (Ann. Ch. Pharm. Ixxiv. 70), who prepares it by
heating to bright redness in a porcelain or platinum crucible a mixture of 2 pts.
dried «d-ammoniac and I pt pure anhydrous borax :

Na«0.2B«0« + 2NH^C1 - 2BN + 2NaCl + B«0» + 4H«0.

The product is a white porous mass, which is pulverised and washed with water to
free it from chloride of sodium and boric anhydride, the final washings being made
witli boiling water acidulated with hydrochloric acid. The boric anhydride is, how-
ever, so completely incorporated with the nitride of boron, that it cannot be wholly
removed by washing. A purer product might perhaps be obtained by using neutrsi
borate of sodium instead of borax, in which case, no excess of boric anhydride would
be present:

Na*O.B«0» + 2NH^a - 2BN + 2NaCl + 4H«0.

Wohler formerly prepared nitride of boron by igniting anhydrous borax with ferro-
cyanide of potassium. It is likewise produced when amorphous boron is heated to
whiteness in a stream of pure nitrogen ; more easily, but with simultaneous formation
of boric anhydride, when boron is ignited in a current of air, or of nitrous or nitric
oxide gas ; also, with incandescence and evolution of hydrogen, when boron is heated
in gaseous ammonia. (Wohler and Deville, Ann. Ch. Phaxm. cv. 69.)

Kitride of boron is a white amorphous powder, tasteless, inodorous, soft to the
touch, insoluble in water, infiisible, and non-volatile. If very pure, it exhibits when
heated at the edge of a flame, a brilliant greenish-white phosphorescence, xmdergoing
at the same time a slow oxidation. Heated in an alcohol-flame fed with oxygen gasj
it boms rapidly, with faint greenish-white flame, giving off fiimes of boric anhydride.
It easily reduces the oxides of copper and lead, giving on nitrous ftimes. Heated in a
current of aqueous vapour, it yields ammonia and boric anhydride :

2BN + 3H«0 - B»0» + 2NH».

AlVaKa^ and the |;reater number of acids, even in the state of concentrated solution,
have no action on nitride of boron ; strong sulphuric acid, however, with the aid of heat,
ultimately converts it into ammonia and boric acid. Puming hydrofluoric acid con-
verts it into borofluoride of ammonium. Nitride of boron undergoes no alteration
when heated in a curront of chlorine. When fused with hvdrate of potassium, it
gives off a large quantity of ammonia. With anhydrous carbonate of potassium, it
yields borate and cyanate of potassium :

BN + 2(K«C0») - KBO« + KCNO.

It does not decompose carbonic anhydride, even at the highest temperatures.

BOXOlTt OZXBB OV. Boric Oxide or Anhydride, Anhydrous boric acid, BK)*.
— This the only known oxide of boron. It is formed when boron bums in oxygen gas,
in the air, or in nitric oxide gas (p. 626) ; but it is moro easily obtained by exposing
boric add, which is its hydrate, to a strong heat. Water then goes of^ and the an-
hydride melts to a viscid mass, which, on cooling, solidifies to a colourless brittle glass
{tnirijied boric or boracic acid) of specific gravity 1*83. It cracks spontaneously in
cooling, and the formatiou of each crack is attended with a flash of light (Dumas).
It is perfectly fixed in the fire when alone, but in presence of water, and still moro of

636 BORON: OXIDE.

alcohol, it Tolatilises to a considerable amount It ia perfectly inodoroiis ; has a
alightly bitter bat not sour taste ; disaolyes readily in water, forming boric acid, also in
alcohoL The alcoholic solution bums with a green flame; so likewise does a mixtuie
of boric anhydride and sulphur.

Potassium heated with boric anhydride decomposes it with visible combustion;
sodium decomposes it quietly. It is not decomposed by phosphoms-Tapour at a red heat,
or by charcoal even at a white heat (Gmelin). It unites with metallic oxides when
fused with them, forming borates. From its fixity in the fire, it is capable of decom-
posing at high temperatures, not only carbonates, but likewise nitrates, sulphates, and
indeed the Mlts of all acids which are more volatile than itsel£

8orte JLold.

Oxide of Boron and Hydrogen. Boracie Acid. 8el sedativum SombergU. 8el
narcoHcum idtrioli. H'BO' or 3H'0.S*0*. — This acid is formed by the oxidation of
boron in presence of water, e. a. by the action of nitric acid or aqua-regia on boron;
also by dissolving the anhydride in water. It occurs native in the tree state in maav
volcanic districts, especially in Tuscany, where it issues from the earth together witL
vapour of water, and is found, either as an effloresence in the neighbourhood of hot
springs, or dissolved in the water of small lakes ^r lagoons {Lagunt^ formed by
the vapours themselves. It is also found in small quantity in several mineral waten,
viz. in the boiling spring of Wiesbaden ; in the iodine-water of Krankenheil near
Fols, and of the Kaiser spring in Aachen ; in the mother-liquor of the salt-spring at
Bex (Baup), and in several hepatic waters. A few borates are also found in natare
(p. 626), especially borax, the acid borate of sodium, which exists in the water of
certain lakes in Central AJsia.

Preparation. — On the small scale, boric acid is prepared from borax. 3 pts. of
crystailised borax are dissolved in 12 pts. of boilinff water, and to the filtered solution
is added 1 pt. of strong sulphuric acid, or so much hydrochloric acid that the liquid
strongly reddens litmus. The greater part of the boric acid then separates on cooling
in crystalline scales, and a larger quantity may be obtained by evaporating the mother-
liquor. The crystals retain a certain portion of sulphuric or hydrochloric acid ; from
the latter they are easily freed by gentle heating and reciystalUsation. To obtain
them free from sulphuric acid, they must be f^ed in a platinum crucible, and then
recrystallised.

Formerly all the boric add of commerce was obtained from borax. It was fizst
separated in 1702 by Homberg, who prepared it by heating borax with calcined ferrous
sulphate in closed vessels, whereby sodio-ferric sulphate was formed, and boric add
was carried over with the watery vapour which escaped. Boric add may also be prepared
by the decomposition of other native borates, e.g, borate of magnesium iboraciU\
and borate of caldum and sodium {boronatrocalcite).

Preparation on the large scale (Pay en. Precis de Chimie industrielle, 4"* id^
1859, L 423). — All the boric add of commerce is now obtained from the volcanic
district of Tuscany, where it is discharged from the interior of the earth by numerous
jets of vapour called euffioni, often rising in thick columns to a considerable height.
The entire surface of the district, consistmg of chalk and marl, is subject to constant
shocks caused by subterranean agendes ; and columns of boiling water are frequently
projected into the air, which is also strongly impregnated with sulphurett^ hydro-
gen. These vapours contain, besides aqueous vapour, carbonic add, aulphydric
add, nitrogen, hydrogen, a ^eous hydrocarbon, and sometimes oxygen, together
with a smafi quanti^ of bone acid and much solid matter carried up mechanically.
Ch. Beville and F. Leblanc found, in the vapour of one of the sufiS,oni, about 91 per
cent CO', 4 per cent. H*S, and 5 per cent nitrogen and combustible gases.

The vapours which issue from the defts do not contain any appreciable quantify of
boric ado, but where pools are formed round the suffloni, eiUier artificially or by
natural condensation of the vapours, the water soon becomes charged with boric ado.
Probably the gre&ter part of the add is first deposited on the sides of the defts
beforo it reaches the surface, and when water penetrates into them, the add is dis-
solved and thrown up in the state of solution.

To obtain the bone acid, the suffioni are surrounded with basins of coarse masoniy,
glazed on the inside, and large enough to endose two or three suffioni. A series of these
basins are constructed on the hill-side, and into the uppermost A B {fip. 106), the water
of a spring is turned, and after remaining there 24 hours, during which time it is kept
in a state of constant agitation by the subterranean vapour, it is made to pass through
the tube a, into a second basin C D, where it likewise remains 24 hours, and takes up
a second quantity of boric add ; thence it passes successively by the pipes 6, e, into
the third and fourth basins, the liquid dischai^ged from a lower basin beiiag con-
tinually supplied from the one above it When the liquid has thus traversed six

BORIC ACID.

called a oaKo,_whCTB it depositB'a quantity of mud, and therwazda into two anuUer

, _ uriea of leaden

n pUn in fig. 107, placed one aboTe tbe other
in the mannerofterracee on awooden scaffold Formerly UiesepaiuTere healed bj wood
Brea ; but thia waa found loo coatly, the district being nearly ban of wood ; the erapo-
ntion ia now performed by means of the aubterraneiin heat, one or more of the jeta

Fiff. 107.

of fleam encloacd in pipea being conducted between the foundation and the bottom of
the paiu. The steam enters beneath the bottom pani, and ia carried renilariy npwarda,
ao that the lowest pans, which contain the moat coaeentmted Uqnid, become moat
heated Thia mode of atiliaing the mbtorraaean heat wai introdumd in 1817, by
Count Laiderel, at tbat time the proprietor of all the lagoons, and had the effect of
eonrerting an unprofitable branch of industry into one which is now the source of
immense wealth.

Another form of ^paratus for the eraporation is shown in^. 109, The liquid,
after leanng the raacoi A, 6, passes into a sbuUow bailer C, from which it is made to

BOBON: OXIDE.

Eoi&ce, gndiullj eraponto, And the solntion ultiiiutaly reaehea the bum F, U t
degree of coaceatntion fit for cmtilliBatioD. Heat u Biq>plied bj the T^xni of ong
of the suffioni iutioduced noder the baam F, And carded i^i nudev the iheetoflttdlaC
Thii method of eTsporaticiii i* maier than the pceoedio^ and d>ee not intiodnM n
mach le&d into the eolation.

The Bolotion of boric add concentrated bj either of these methoda, ii aett miud
vith the molher-liquoF of a preceding operation, and poured through the fumda B,
- ■ - ^••- tab.8,S,(;Ij7. ■ ■■■ ' ' ■•■ ■

a S, S, (_fyi. 107 IDS, 110) which ai

■ made of wood lined

Fiff. 111.

into the round oyatial lining tc
Fiff. 110.

vilh lead. The ajaCaia are taken out aiter a vhile, and placed to drain in butelB, 1,
on the top of the tabs, the taothei^liijaor ronning into recsiTers pLieed nnder the ^rx.
Laatly. the ciyBtaU, vhile still moiat, are apread oat on the floor C C. of the drjini
chamber D(/!^. III). This chamber haa adoablefloor, and is healed t^ ateam ato-
ing at A, and ciicnlatiiig between the two floors.

^The prodnct thus obtained is tat from para, not containing more than ahont 76 pv
cent, of boric acid. The compositioii of the erode acid, accordijig to the inaljsn d
WitWt«n and Payen, in ut followa :

Ciystallised boric add
Ferric lalphate .
Salphate of alamininu
Sulphate of caldam
Salphate of mt^jneBinni
Sulphate of ammaniam
Salphate of aodiiun
Sulphate of potawiam
Sulphate of manganese
Chloride of unmoninm
Silica ....
Salphoric acid .

76B

2-4 to H ■
11-0 to S

1'3

8-«

T-OtoS-St

cent, boric add and 10 1"

] per cent, boric add and 10 1"
jjd magneaioni. KicbardBOD lod
to 12 per cent, of the pme lai

Schmidt foond, in crade boric acid &Dm Taacany, 8
cent, imparitiee, chieSy the sulphates of ammoniam i

Bcowell foaiid in some samples, not more than 36 to 12 per

[? crystallised or anbydrous]. The experience of the French mano&ctoren of boru,
aeema to show that the impurities in boric add &om Tuscany becmne greater jeu bj

J ear, which may perhaps be dae to the increasing dtaint4f;ratiou of the eailliy alial*
y the aqneoas and add Taponn.
Of the origia of the TBponi* by which the boric add is bronghttotheaotftec; notiiiw
certain is known. Domos has soggeeted that they may proceed from a deep-enttd
bed at sulphide of boron, with which the water of h^es, or c^ tiie na, comes in cMtwt
thereby producing boric and sulphydrio adds. Part of the boric add m<g'thoi be
supposed to act upon the carbonates of olciam and magneaiam in the sdl, oanmtug
• ladudlBi UDd, clar, Ac. f lKliidlBt«iu>ceMUer.

BORATES- 639

them into borates, and setting free carbonic anhydride. The sulphuretted hydrogen
being oxidised by the air, yieldB firee sulphur, which is deposited on the edges of
the suflSoni The ammonia and organic matter are derived from the water, and the
ealine impurities from the water and the earthy strata, throogh which the vapours
make their way. Bolley supposes that the boric acid and ammonia may result firom
the action of solution of sal-ammoniac at a boiling-heat, on borates contained in the
earth ; and according to Warington, the formation ^ these products may be ascribed to
.the action of water on nitride of boron. There is, however, nothing positive to *indi-
(ste the nature of the particular compound or compounds of boron, to which the elimi-
nation of the boric acid is really due.

PrcperUes. — ^Boric acid oystallises firom water in white, translucent, nacreous, six-
sided laminse, somewhat unctuous to the touch; it is inodorous, and has a fsiint,
scarcely add, rather bitterish, cooling taste. Specific gravity =* 1'48. It dissolves in
2-67 parts of water at 18® C. ; in 14-9 parts at 25<*, in 107 parts at 60° in 4*7 parts
at 76^, and in 2*97 parts at 100°. (Brandos and Firnhaber.) It is still more
8(^uble in alcohol and in volatile oils.

Boric acid dissolves in warm concentrated sulphuric, nitric, or hydrochloric acid, but
separates for the most part on cooling, or on addition of water. Its solubility in water
ia increased by addition of tartaric add, tartrate of potassium, Bochelle salt, racemic
add, or alkaline racemates.

Scl

160° it is deprived of 2 at. water more, leaving H'B^O' = H>0.2B«0", and at a
stronger heat, the remaining water goes of^ leaving the anhydride BK)', as a fused
visdd mass, which solidifies to a fissured glass on cooling (p. 635).

Reactions. — ^A cold saturated aqueous solution of boric add colours litmus-tincture
wine-red (the tint of port wine), like carbonic acid, but a hot saturated solution
colours it bright red. Turmeric paper moistened with the alcoholic solution of boric
add acquires a reddish-brown colour, quite different from that produced by alkalis,
and becoming distinct onl^ after drying: it is intensified by adds, especially by
hydrochloric, sulphuric, nitric, and tartaric acids, and turned black by alkalis.

The alcoholic solution of boric add bums with a beautiful green-edged fiame, a
reaction which is quite characteristic of boron, provided copper and certain chlorine-
compounds are absent. This green colour is not produced, however, when the add is
in combination with an alkali or other base ; and its production is partly prevented
bj the presence of chloride of sodium or calcium, and even bv small quantities of tar^
trate of potasdum or Bochelle salt (doubtless because these salts are partly decomposed
by the boric add, and neutralise it), also by free tartaric add or phosphoric acid. In
either of these cases, the green colour appears on addition of sulphuric add, or of a
considerable quantity of hydrochloric acia (H. Bose, Pogg. Ann. (aL 645). It must
be observed, however, that a green flame, though of a more bluish tint^ is produced
when hydrochloric add itself is dropped into burning alcohoL (See p. 630.)

For the reactions with metallic salts see p. 640.

Borates. (Berzelius, Traits, voL i — iv. Gm. voL i — vi. Handw. d. Chem.
2<* Aufl. ii £21 303. H' Rose, Pogg. Ann. ix. 76 ; Ixxxvi. 681 ; Izxxvii 1, 470 and
587; Ixxxviu. 299, 482; xd. 452. Wohler, ibid, xxviiL 525. Bammelsbere,
ibiBL Ixix. 445. ^Ebelmen, Ann Ch. Phys. [3] xxxiiL 34. Herapath, Ann. Ch.
Pharm. IxxiL 254. Bolley, ibid. Ixviii. 122. Laurent, Ann. Ch. Phys. [2] Ixvii
215. Tissier, Ck>mpt. rend, xxxix. 192; xlv. 411. Bloxam, Chem. Soc Qu. J.
xiL 177 ; xiv. 143.)— JBoric acid forms salts in which the proportion of anhydrous base
(MK>) to anhydrous add (B*0'), or of metal to boron, ranges between the limits 9 : 1 and
1 : 6, Those which contain equal proportions of base and acid are usually regarded
as neutral or normal borates, the rest as basic or add. The following proportions
have been observed :

Basic. Keutral. Acid.

9M«0.BH)« M»O.B'0» 2M»0.3BK)«

6M«0.B«0» M«0.2B«0«

9M«0.2B«0> M«0.3B«0«

3M»0.B*0« M*0.4B«0«

6M«0.2B*0« M»0.5B«0»

2M«0.B*0» MH).6B*0»

3M?0.2B«0«

Most of the so-called add borates, however, contain several atoms of water; and if
the whole or part of this water be regarded as basic, we shall find that nearly all
borates may be arranged ia two classes, orthoborates and metaborates (so called

640 BORON: OXIDE.

from their analogy with the oitho- and meta>pho8phatefl and silicates), the eompontkn
of which may be represented by the following ^neml fbrmukB, the symbd 11 denotiBg
either a single metal, or two, or three metals, including hydrogen :

Orthoboratcs 3MH).BK)« or WBG* = 3-|o«

Metaboratee «(MK).BH)»), or M-B^«- « ^^| 0^

The latter formula, which, when n ■- 1, becomes that of the so^saDed neatzil
borates, MBO*, includes the greater number of the salts of boric add. NeTerthrieu
it appears probable that boric acid is essentially tribasic, and that the bontee con-
taining 3 at metal to 1 at. boron are its normal salts '(hence called orthobontes) :
for crystallised boric acid contains H'BO*; and there are boric ethers oontainingS aL
alcohol-radicle to 1 at. boron, whereiui none are known of the form BBO*. Hommr
it appears from the experiments of Bloxam, that boric add, when ignited with metalUe
hydrates, mostly drives out 3 at. of water, forming a trimetallic borate, exc^in the eaae
of hydrate of potassium, in which the water is retained with peculiar force ; and vbeo
heated to brignt redness with carbonates, it expels a quantity of carbonic anhydride
approaching more nearly to 3 atoms as the base is weaker, mat limit being actually
reached in the case of strontia. (See Bok^tbs of Babiux, Lithiuic, Fotasstoii and
Sodiuil) There appear also to be a few borates intermediate in composition betwen
ortho- andmetaborates, viz. M*B*0» « M*BO«.MBO*.

Borates containing more than 3 at. metal to 1 at. boron may be regsrded as oom-
pounds of orthoboratcs with metallic oxides or hydrates (see Borates op Aiuvniux);
and those anhydrous borates which contain more than 1 at. boron to 1 at metal may
be regarded as metaborates combined with boric anhydride ; e. g, anhydrous bono,
Na«0.2B«0» - 2NaB0«.B«0«.

Borates are formed by the action of boric add on metallic oxides or their salti,
either in the wet or in the dry way. At high temperatures, boric add or snbydrida
decomposes carbonates, sulphates, chlorides, and indeed the Baits of all ToIatQe adds.
Add borates, borax for example, take up additional quantities of base when ignited
with metallic oxides, and likewise decompose the salts of volatile adds. In the vet
way, on the contrary, boric add acts as a very weak add, being separated from iti
combinations completely by most acids, andpartiaUy, under certain drcnmfltancwi, even by
carbonic add, sulphydric acid, and water. In concentrated solution, however, it decom-
poses carbonates, especially at the boiling heat ; also soluble sulphides and precipitated
sulphide of manganese. It has but little power of neutralisiiig the alkahne reaetioin
of the stronger bases, so that even the solutions of many of the poWacid borates
exhibit a strong alkaline reaction to litmus, which is not neutralised tul the base is
combined with 5 or 6 atoms of boric add, and even then the liquid does not exhibit
an add reaction.

The borates of the alkali-metals dissolve readily in water, but are predpitated by
alcohot All other borates dissolve but sparingly soluble in wateir ; but none are petfeetly
insoluble. The sparinsly soluble borates may be obtained by predpitation. Jtfanyra
these predpitates are soluble in excess of the soluble metallic saU from which they have
been lormecl, but not in excess of alkaline borate ; e. g. the predpitate formed by bonx
dissolves in solution of chloride of barium, but not of borax : they are often Hkevise
soluble in chloride of ammonium and in free boric add. The sparingly soluble borates
are easily decomposed by water, espedally when boiled with it the boric add being
sometimes almost completely removed. Hence it is very difficult to obtain these alts
in the pure state. H. Rose, in his elaborate investigation of the borates, purified the
predpitates as completely as posdble by repeated pressni« between paper irithoat
washing, and afterwards estimated the quantity of foreign ralta still attached to the
precipitate. The soluble borates are likewise decomposed by water. If a strong
solution of borax be mixed with slightly reddened tincture of litmus, the liquid retuns
its faint red colour, but on dilution with water becomes distinctly blue, beharing
indeed like a dilute solution of free alkali mixed with boric add. Neutral borates of
alkali-metal exhibit a similar reaction.

When a solution of an alkaline borate coloured with tinctore of litmus is gnduallf
mixed with sulphuric add, the liquid exhibits a wine-red colour till all the alkali is
saturated with sulphuric acid ; after that, a single drop of sulphuric add produces the
bright red colour.

Solutions of alkaline borates absorb carbonic and sulphydric acid gases ; expd am-
monia from its salts when boiled with them, like dilute alkalis ; their dilute solutions
also react like alkalis with mercury and silver-salts, and with many organic substaneesL
(See BosAX, p. 648.)

The soluble borates, both neutral and add, give white predpitates with solutions ol

BORATES. 641

chloride of barium, chloride of ealoitmij alvm, solphate of gino and nitrate of lead; zed-
diah wiUi sulphate of oobalt ; greemsh with sulphate of nickel ; yellowish yntii ferric sul-
phate in the cold, brown on boiling. These precipitates dissolve easily in sal-ammoniac ;
and if ^ey have been produced by an acid borate of alkali-metal, borax for example,
they dissolTe pretty reaaily in an excess of the salt from which they haye been obtained ;
The precipitates formed by neutral borates of alkali-metal in the same solutions ex-
hibit simiur characters, excepting that they are less soluble in excess of the earth-
metal or heavy metal salt^

Solution of borax or of monoborate of sodium, does not precipitate sulphate of
wtoffnenmn in the cold; but on heating, a precipitate forms which disappears again on
oocSiag; completely; if formed by the acid borate; nearly, if by the neutral borate.
Both neutral and add borates of alkali-metal form with manganous salts, a precipitate
insoluble in excess of the latter, easily soluble in sal-ammoniac

Dilute solutions of neutral borates of alkali-metal form with nitrate of silver^ a
brown precipitate of nearly pure oxide of silver, insoluble in excess of water, easily
soluble in ammonia or nitnc add. A concentrated solution of neutral borate forms
with silver-salts, a brown predpitate which dissolves in a large quantity of water,
leaving only a slight residue of oxide of silver. Concentrated solutions of acid
borates of alkali-metal form with nitiate of silver a white predpitate of borate of
silver, completely soluble in a large quantity of water. Borate of ammonium forms a
white preapitate in concentrated silver-solutions, none in dilute solutions.

Soluble borates, whether neutral or add, give with mercuric chloride, a brown
predpitate of oxvchloride, insoluble in excess of the mercuiy-salt. Concentrated
solutions give witn neutral merourous nitrate, a yellow-brown precipitate, soluble in
much water: dilute solutions, a blackish -grey precipitate which remains long sus-
pended. Basic mercurous nitrate forms with a strong solution of borax, a dingy,
yellow-brown predpitate which dissolves in a large quantity of water, leaving black
mercurous oxide.

If the solution of a calcium or magnedum salt be mixed with excess of boric add,
and to the boiling solution borax be added in quantity just sufBdent to neutralise the
add of the caldum or magnesium salt, no predpitate is formed ; similarly with salts
of manganous, ferrous, cobalt, nickel, cadmium and zinc salts; but solutions of
aluminium, chromicum, ferricum, stannicum, lead and copper, yield predpitates when
thus treated. (Tissier.)

For the reactions of borates with fluorspar and add sulphate of potassium before the
blowpipe (see p. 630).

BoBATBS OP AxTJUiNiuii;. — A solution of alum mixed with alkaline borates yields
predpitates which, according to H. Hose, are double salts of borate of aluminium and
borate of the alkali-metfd mixed with sulphate of potassium; water abstracts the
greater part of the latter and of the alkaline borate, leaving a basic borate of aluminium.
In this manner, the predpitate produced by monosodic borate yields sexbasic borate
of aluminium, 2(A1*0*)']'3*0« + 8 aq. = 6aTO.B*0' + 8aq., which may also be regarded
as an orthoborate combined with 3 at. hydrate of aluminium = a/*£0*.3a/H0. — By
adding add borate of sodium (borax) to solution of alum, a precipitate is formed con-
taining 8(AlW*.2BK)«+7aq. « 9a^0.2B«0»-^ 7aq. or 2a^BO».3a/HO + 2aq.

Ebefanen, by heating a mixture of alumina and borax for a long time in a porcelain
furnace, obtained a nonobadc salt 3(A1*0»)"'.B«0« « daPOJSK)* or araO».3a/»0.

BoBATBS or AjOfONixTX. — Boric add forms with ammonia, several salts which may
all be regarded as metaborates, expressed by the general formula M'B^O^", the n at. M
being made up partly of ammonium, partly of hydrogen.

a. (NH^)'HB^O' is obtained by saturating crystallised boric add with dry ammonia
ns, or by dissolving one of the following salts in warm concentrated aqueous ammonia.
The salt obtained by the former process contains 4 at., that by the latter 1 aU water
of crystallisation.

h. (NH*)HB'0* + {aq. ciystallises from a solution of boric add in excess of am-
monia, in veiy efiSorescent crystals of the dimetric system, soluble in 12 pts. of water.
It effloresces like the preceding, giving off part of its ammonia.

e. (^H*)H"B*0*+2aq. is obtained, according to Arfredson, by dissolving boric
add in warm caustic ammonia, till the alkaline reaction is nearly neutralised The
liquid, if slowly cooled, deposits rhombic crystals, exhibiting, according to Schabus,
the faces oP . P . ooP. oo P oo, and often assuming a prismatic form fh)m the predomi-
nance of oP and of four P-faces situated in the same zone ; sometimes twin crystals
occur. It is permanent in the air, dissolves in 8 pts. of cold water, gives off ammonia
on boiling, and leaves boric anhydride when ignited. A salt called Larderellite, of si-
milar constitution, but containing less water of cnrstalUsation, viz. (NH^)HB''0^ + Aaq.
was found by Bechi in the boric add formations of Tuscany, in yellowish-white,
transparent, tasteless crvstals, exhibiting under titie microscope, the form of rectancxdar

Vol. I. T T

642 BORON: OXIDE.

tablett, and by polarised light the optical appeanncea of gypenm. It disMlTCs ii
water, but the eolutioii when eraporated d^poaita the salt (NH^)H*B*0**+2aq.

d. (NH«)H«BK)*« + faq. (Laurent) + 2 aq. (R am m els berg). First prepucd bj
L. G-melin, who, however, soppoaed it to contain 4 at boric acid to 1 at ammoiua
(Handbook ii 436). Aooording to Bammelflbeig, however, it has the composition
above given, and is isomorphous with the ooireaponding potaaaiamHult Aceoiding to
Laorent, it is obtained bj dissolving esoees of boric acid in aqneoos *mnwuiiV ^ j^
crystallising. It forms small shining prisms of the monodinie system, genenlly in
cruciform groups. It is permanent in the air, dissolves in abont 8 pts. of cold vater,
and, like the preceding salts, has an alkaline reaction. The solution gives off ammooia
when boiled, and the residne solidifies to a grannlar ciTstaUine mass, which is per-
manent in the air, and i^pears to contain 6 at boric acid to 1 at ammonia.

e, (NH^)'H'BH)**+aq. is obtained by dissolving borio add in aqneoos ammonia.
(Arfvedson.)

A solution of borate of ammonium has been sucoesafnlly used for rendering mnaUn
and other light fabrics non-inflammable. When tissues thns impregnated are held in
the flame of a candle, they are merelv carbonised, the water and ammonia vfaidi
esci^ preventing the communication of the flame. If the Ofmtact with the flame be
prolon^sd, the boric add melts and forms a glas^ varnish round the chaired tinae^
which prevents it from taking flre.

B0RA.TB OF Ajctl. See Bomo Etrsbs (p. fl49).

B0HA.TE8 OF Bajuuic — ^Boric add ignited with excess of hydrate of barium expeli

3 at water, and forms the tribarytic arthoborate, 38*60*. Heated with excess of car-
bonate of barium, it expels 2 at. carbonic anhydride at a dull red heat, and 2J ai at a
bright red heat, forming the anhydrous salts, Ba«B*0* - 2Ba*0.BH)* and Ba>fBK)>>-
6Ba-0.2B*0*. (Bloxam.)

By precipitating barium-salts with borates of the alkali-metals, borates of barium
are obtained, mostly as white crystalline powders, differing in composition aooording
to the composition and relative proportions of the salts employed, the tempenr
ture of the solutions, and the duration of the washing. They are probably all
metaborates.

a. MonometaboraUt BaBO* + 6aq. (or possibly a monobarytic orthoborate, BaH'BO"

+ 4 aq.), was obtained by Berzelius by precipitating chloride of barium with manoborate

of potassium. According to H. Rose, when prepued from cold solutions, and dried at

100^ C. after pressure between paper, but witnout washing, it has the composition

BaBO*-f- ^aq., and when predpitated from very hot solutions it contains more than

4 aq., but less than 1 aq. To <mve off all the water requires a strong heat The salt
dissolves in cold, and more readily in hot water, especially in presence of smmaniaffal
salts, and therefore cannot be completely washed.

b. Sesquimetaborate. Ba'HB*0' + 7 aq. — ^Laurent obtained this salt by mixing a
solution of chloride of barium with pentaborate of sodium, under drcumstances pot
particularly specified. According to H. ^ose, the predpitate obtained by mixing
chloride of barium with an add b[>rate of alkaU-metat has, when dried at 100^ C^, the
composition Ba*H*B*0** +}aq.

c. Dimeiaboratey BaHB*0* -i- 2aq, is predpitated in white flocks when a sdntioii of
nitrate of barium is added by drops to excess <of solution of Borax mixed with am-
monia. It dissolves in 100 pts. of wateiv more easily in ammoniacal salts and ia ex-
cess of chloride of barium. (Laurent)

d. Trimftaborate. BaH*B*0* +.6 aq.— Predpitated as a white czTstalline powder,
when a warm solution of nitrate of barium ia added by drops and with stjiring, to ex*
cess of pentaborate of sodium.

Borates of Oaduuh. — The precipitate formed on mixing the cold solutiona of
borax and sulphate of cadmium contains, after being merdy pressed, the moncbordr^
CdBO', mixed with a small quantity of an add sut The predpitate from boiling
solutions consists chiefly of 2CdB0*.CdH0 + aq.

Borates of Calcium, a. Orthoborate. CaH*BO« (dried at lOO^' C.)-^The fo^
mula mieht also be that ot a monometaborate, CaBO' + H*0, but the first riew of its
constitution is the more probable, inasmuch as the salt gives off* 1 at H as water, onlj
at 200° C, and is not completdy dehydrated even at 300°. It is produced by precipi-
tating chloride of calcium with monoborate of sodium, probably also when solution of
borax is predpitated by lime-water. It is somewhat soluble in water, and is decom-
posed by not water.

b. Sesquimetaborate^ Ca*HB*0*, appears to be predpitated, together with variable
quantities of the dimetaborate, when caldum-salts are mixed with solution of bonx
(H. Rose). A similar composition appears to belong to rhodicitty a mineral foimd m
the Ural, in small, hard, shining, yellowish-whitecrystals of tetrahedral habit It m*
not been exactly aniUysed, but appears to contain 4B to 3Ca» (G, Boss.)

BORATES. 643

. e. JHmetaboratB, CmEBH)*. — ObtuBed, according to Tonnermaim, when borax is
precipitated by nitrate of calcinm. It oocnw also aa a white efflorefioence composed of
crystalline needles containing f at water, on the plain of Iquique in Ecuador, South
America^ fomung the noinertd called borocalcite, hfdroborocaloite^ or hayente (Ulex).
Bechi found a calcic diborate with | aq. in a<i old lagoon*crater in Tuscany.

d. TtirmMtaboraU, CaH*B*0* + } «q.«*-P:recipitated on boiling milk of lime with
excess of boric acid.

Sorate of calcium ooeuzs associated with silicate of caleium in hotryclUe and datoiite
{g. «.), and with magnesia in kydroboracUe {q, v.)

BoRAXB or CoBAiT is probably oontained in the glass fluxes fonned with cobalt-
compounds and borax. Cold solutions of a eobalt-salt and borax yield a reddish pre-
ei{HJtafte, which, after drying ait lOO^' C, consists chiefly of 2CoB0''.CoH0 -f-jaq. It
is soluble in water, and melts to a blue glass when strongly heated.

BoRATW OP GoFPBB.— It is difficult to obt«in these salts in a definite state. Sul-
phate of copper mixed with solutions of alkaline borates, yields precipitates consisting
of compounds of borate and oxide of copper mixed with sulphate of soda and basic
■oi^biite of coi^Msr, which are deeompoeed by water, leaving a residue composed of
oxide and borate of copper, but with less boric acid than the original precipitate.
Cold eoBoeatrated solutions of eupric sulphate and monoborate of sodium Tield a pre-
cipitate which, after washing, oonaists of OuHO.^CuBO' + aq. The precipitate from
the same solutions mixed hot is, after washing, OuH0.20uBO^ That obtained in like
manner ftom oold conoentrated solutions of cuptie suldiate and borax is an orthoborate
containing 2 at. copper, viz. (Cu*H)BO' + j aq. Tlie same precipitate is obtained
fiorn hot concentrated solutioDs of cuprie sulphaie and borax, especially if the copper-
salt is in excess. It ub a loose blue-green powder, sparingly soluble in water, but de-
composed by water, leaying the compound CiiBO'.3GufiO + |aq. Cold c^i/ttte solu-
tions of the same salts yield a precipitate containing 5Cu to 2B and 6H, while tiie pre-
cipitate from hot dilute solutions contains 10 oir 12 at. Cu to*l at B.

BoUey has suggested the use of the green parecipitale, obtained from cold solutions
of 2 pts. cupnc sulphate (blue -vitriol), and 3 pts. borax, as a substitute for the
arsenical greens usea in painting, paper-staining, and calico-printing.

BoiuLTn OP ExsTL.. See Bono Ethbbs (p. 660).

BoRATSs OP Ibon. — Ferrie numoTnetaboraUj Fe*0'.3B*0* + 8 aq. or /<jBO* + |aq.
has not bem prepared artificially, but has been found by Bechi in an old lagoon-crater
in Tuscany : hence called Laaunite,

Ferric orthoborate, Fe*0*.frO" or /<J^BO', is not known in the separate state, but
only in combination with borate of sodium or with ferric oxide. On mixing a solution
of ammoniofecrie sulphate (ammonia-iron-alum) with monometaborate of sodium, a
bulky precipitate is formed, which, after being pressed between paper, but not washed,
is a sooio-ferrie borate containing NaB0'.4^e%0' + 8 aq. Cold water abstracts boric
aeid and borate of sodium, leaying an oxyborate, which, after drying at 100^ C, is
6FeH)«.B^O» + 6aq. or 16/^0. V«*BO» + 6 aq. By precipitating ammonioferric sul-
phate with botox, a light brown bulky predpitaite is fonned containing NaH^BK)*.
4/e%0*+aq., and reduced by waslung with water to 2 V'^'O.^tf'BO* + 9 aq. or
9Fe«0«.B'0« + 9aq.

BoKATBS OP lauji, — a. The monofrutahoratej PbBO'+Jaq. is obtained, according
to Herapath, when the precipitate formed by borax in a neutral lead-salt^ is digested
for some hours with strong ammonia. It is said also to be produced when a solution
of basic acetate of lead is partially precipitated by borax, and, according to H. Rose,
by washing with cold water the precipitate formed on mixing the oold solutions of
bonix and nitrate of lead. It is a white, amorphous, heayy powder, insoluble in water
and in alcohol, soluble in dilute nitric and in warm acetic acid, from which solutions
it is precipitated by ammonia. It gives off some of its water at 120^ C, the whole at
160^, and at a red neat^ melts to a colourless glass, of specific gravity 6'69S.

b. The seaquimetaborate, Pb'HB'O* + |aq. formed by adding a large excess of borax
to a boiling solution of a lead-salt^ resembles the preceding, gives off 1 at water be-
tween 170^ and 200° C, and melts to a colourless glass, of specific gravity 6-236.
(Herapath.)

e. DtmeUtborate, PbHBK)* + {aq. obtained by boiling the salt b with borax. Light
amorphous powder, which gives off its water between 200° and 230° C, and at a red
heat mdts to a vi^eous mass (Herapath). When 100 pts. lead-oxide are fused witii
64 pts. boric anhydride (1:2 at), a nearly colourless glass is obtained as hard as
flint-glass, and possessing much higher refnZctive power.

Bogie borates^ — ^According to H. Hose, the precipitates formed with nitrate of lead
and either mono- or di-borato of sodium, are frequenti^ basic salts, probably mixtures
of monoborate and hydrate of lead, varying in composition according to the strength

XT 2

644 BORON: OXIDE.

of the solntions and the duration of the 'washing. Hot^ yeiy dilute solutioss, prt a
precipitate to which Hose assigns the fbrmnla ^PbO.B(^) -t- FbOMO ■¥ aq^ at
2(3PbBO«.PbHO) + aq.

Borochloride of Lead, PbBO'.PbCl + ^aq^ is obtained bj mixing hot soktbos of
borax and chloride of lead, and czTStallises in very small, iire^ular, nacreous needlei,
which are not decomposed by cold water, but gradiuiUj by boihng water. It giTee off
all its water between 120^ and 160^0.

Boronitrate of Lead, PbBO'J^NO*, is deposited in in«gular shining erjMa, from
a solution of borate of lead in nitric acid, evaporated till a film forms on the sotfiux,
At 120^ G. the ctystals give off water and a little nitric add, and at a higher tempo*
rature evolve nitrous acid and melt to a colourless glass.

BoBATB OF Lrrsruic — Boric acid heated to bright redness with carbonate of lifhimn,
expels 2J at carbonic anhydride, forming the salt 6Li'0.2BH)'. (Bio x am.)

BOBA.TES OF Maokesiuv. o, Orthoborate. Mg'BO*. — Ebehnen obtained this salt
by fusing magnesia with boric anhydride, and exposing the vitreous mass, in a plati-
num dish, to the strongest heat of a porcelain fomace for several days, till the exoen
of boric anhydride was volatilised. It formed radiating nacreous crystals, of specific
gravity 2*987. It is also obtained as a hydrate, Mg'BO*-!- 6 aq, by boiling a mizhire
of borax and sulphate of magnesium, and washing the precipitate (which contBins
borate of sodium, magnesia, and hydrate of magnesium) wito cold water. When boiled
with water, it gives up part of its add, and leaves a basic salt which absorbs carbonic
add from the air. The predpitate formed by boiling sulphate of magnesium with borax,
redissolves completely on cooling.

b. Motuxmetaoorate, MgBO*. — ^Obtained as an amorphous predpitate, containing 2 at
water, on mixing the hot solutions of borax and mtrate of magnesium (Laurent).
The same Bait, but with 4 at water, was obtained, according to Wohler, when a mixed
solution of borax and sulphate of magnesium, which had been heated, and had afte^
wards become dear by cooling, was left to itself for several months in winter in a
place where the temperature o^en fell bdow 0^ C. It formed slender radiating needles,
insoluble in water, soluble in dilute adds, repnecipitated in needles by ammonia, giving
off water and becoming turbid when heated. Boracite, from Segeberg in Holstein,
appears to be a monoborate of magnesium, while that fsom Liuneburg is a mixture or
compound of 3Mg*0.4B''0«, or 6MgB0«.B*0«, with MgCL

c. THTnetaborate, MgH'B*0' + 3 aq. separates, according to Kammelsberg, in czyB-
talline crusts, when a concentrated solution of boric acid is boiled with carbonate or
hydrate of magnesium and the filtrate is evaporated.

d. Tetrameiaborate, MgH'BHD^ + aq. — This, according to lAurent is the compo-
sition of the last crops of crystals deposited when a solution obtained by boiling haan
acid with magnesium is left to evaporate spontaneously.

e. Hexmetaborate, MgH*B*0"+ ^^"aq. — Granular salt obtained by heating hydrate
of magnesium with excess of boric acid ; mdts to a porcelain-like mass (Bammels-
berg). Perhaps a mixture of one of the preceding salts with free boric add.

Magnesio-^hromic Borate. — A salt containing 6Mg*0.3Cr*0'.2BK)*, is obtained
by heating for five days in the porcelain furnace a mixture of 20 gnu. chromic oxide,
15 grm. magnesia^ and 20 grm. E>oric anhydride, bdng depodted in the cavities of die
fUsed mass in grass-green microscopic crystals, of specific gravity 3*82. (Ebelmen.)

Magnesio^ferric Borate, 6Mg«0.8Fe*0».2B«0", is obtained by fusing in like
manner a mixture of 26 ^rm. ferric oxide, 20 grm. magnesia, and 26 grm. bone anhy-
dride, in small, black, prismatic crystals, of specific gravity 3'85.

BoiLLTB OF MsTHYii. See BoBio Ethsbs (p. 650).

Borate of Nickel. — Cold solutions of borax and sulphate of nickd yidd a preci-
pitate of NiBO* -¥ aq. or NiH*BO', from which cold water abstracts boric add, leaxing
a salt containing 2KiB0'.NiH0 + 2 aq. By boiling for some time with bcA^ tbia
precipitate is converted into the dimetaborate, NiB^BK)^.

Borates of Potassiuh. — a. The monometaborate, KBO', is formed by melting
together 70 pts. (1 at) boric anhydride, and 138 pts. (1 at.) carbonate of potsasiom.
It melts at a white heat, has a caustic alkaline taste, dissolves in water, ana separates
slowly from the solution in ill-defined crystals which, according to Schabus, are mono*
clinic. The solution should be evaporated out of contact with the air, as it absorbs
carbonic add. Boric anhydride, heated to redness with excess of hydrate of potsssinm,
expels 2 at carbonic anhydride, forming the salt K*BK)* « 2KK).B*0». (Bloxam.)

b. The dimetaborate, iSBH)*, is prepared by supersaturating a boiling sdntion of
carbonate of potassium with boric acid, and then adding pure potash m sufficient
quantity to produce a strong alkaline reaction. It crystallises sometimes with 2aq.
sometimes with 2Jaq. The hydrate, KHB*0*. + 2aq., forms r^ular six-sided prisms,
which dissolve re^ily in water with strong alkaline reaction, and swell up considerably

BORATES, 645

when heated. The oiher hydrate, EHB*0* + {aq. : forms right rhombie prisms of
98^ Z6\ with basic brachjdiagonal end-faces. It behaves like the former hydrate, but
when kept in a closed yessel, separates into a liquid and a solid salt, apparently the
hydrate with 2aq.

C Irimetaboraie, KH^«0«+ 3aq. or perhaps, tri-orthoborate, KBPBW.— Obtained
like the preceding, but with a smaller (Quantity of caustic potash. Separates in rect-
angular prisms, with four-sided pyramidal summits. Permanent in the air ; melts
withofut much tumefaction. (Bammelsberg.)

£ Peniametaborate^ KH'B^O** + 2aq. — Formed when a boiling solution of carbonate
of potassium is mixed with a BufEudent quantity of boric acid to produce a strong acid
reaction. The solution on cooling deposits small shining prisms, isomorphous with
the cozresponding ammonium-salt. Permanent in the air, sparingly soluble in cold,
easily in hot water; neutraL (Bammelsberg.)

BoiuiTBS OF SxLTEB.— The precipitates formed in solution of nitrate of silver by
alkaline borates vary in composition according to the dilution and temperature of the
the Bolntiona. ^er^ dilute solutions, especially if hot, yield a precipitate of pure
oxide of silver (H. Bose). A moderately dilute silver-solution mixed with a strong
solution of borax, yields a flocculent precipitate of the monometaborate AgBO', which
when diy is a white powder blackenea by li^ht. It dissolves in a large quantity of
water ; but is decomposed by a small quanti^ ; melts at a gentle heat. The same
salt is obtained as a curdy dirty yellow hydrate, AgBO* + { aq., on mixing concen-
trated solutions of nitrate of silver and monoborate of sodium, or boiling concentrated
solutions of silver-salt and borax. It is decomposed by washing with water, especially
if ho^ which ultimately leaves nothing but oxide of silver.

Acid borates of silver have not yet been obtained pure. Bose states that cold con-
centrated solutions of nitrate of silver and borax yield a white precipitate containing
3AgH) to 4B'0', and after washing with a Httle cold water, which turns it brown,
4 Ag^ to 6BK)'. According to Laurent^ nitrate of silver yields with pentaborate of
potassium, an acid borate of silver which decomposes partflEilly in washing.

BoBATBS OF Soniux. — Boric anhydride fused with excess of hydrate of sodium
expels 3 at water and forms irisodic orthoborate, Na'BO*.

B'O' + 6NaH0 - 8H»0 + 2Na«B0«

(Bloxam, Chem. Soc Qu. J. xiv. 143). Fused with excess of carbonate of sodium at a
bright red heat, it expels 1| at. carbonic anhydride and forms: Na'B^O' or 3Na'0.2B'0'.

2B*0« + 3Na«C0» = Na«B*0» + 3C0«.

(Arfvedson, Gmelin's Handbook, iii. 87 ; compare Bloxam, Chem. Soc Qu. J. xii.
186). By fusing borax with excess of carbonate of sodium, Arfvedson found that 1 at.
anhydrous borax expelled 3 at carbonic anhydride producing a dibasic borate of
•odium or tetrasodic borate: Na^BK)* or 2Na^0.B*0':

Na«0.2B«0« + 8(Na'0.C0«) - 8C0« + 2(2Na»O.BK)«),

1 at carbonate of sodium f^ised with 1 at boric anhydride yields anhydrous mono-
metaborate of sodium^ NaBO' or Na'O.BK)*, and with 2 at boric acid anhydride, it
yields anhydrous acid borate of sodium, Na«BW ^ Na*0.2B«0» = 2NaB0» B'O*.
The aqueous solutions of both these salts yield crystalline hydrates which might be
regarded either as orthoborates or metaborates, but are most probably the latter.
Bespeeting tiie behaviour of the tri- and tetrasodic borates in ttte hyorated state,
nothing appears to be known.

Monometaborate or Neutral Borate o/^0(£ttfm,NaBO*, is produced by heat*
ing 62 pts. of crystallised boric add, or 191 pts. crystallised borax, witn 53 pts. of anhy-
drous carbonate of sodium at a heat near the melting point of silver. The unfused mass
thus obtained dissolves in water, with rise of temperature ; and by cooling the hot but
not satorated solution, the hycbated salt NaB0^ + 4aq. (or possibly Ka'BO* -r 3 aq.)
crystallises in lai^ oblique rhombic prisms with lateral angles of 130^ and 70^.
It has a caustic al&line taste, and quickly absorbs carbonic acid from the air, both in
the solid state and in solution ; but on boiling the solutions, the carbonic acid escapes
At 67^ C. it melts in its water of crystallisation, and after the liquid has cooled for
some time, the hydrate NaB0' + 3aq. separate in indistinct crystals. At a stronger
heat, it gives off all its water, and forms a friable tumefied mass, which absorbs
carbonic acid from the air.

Dimetaborate or Acid Metaborate of Sodium, Na«BW « 2NaB0«.B«0*, or
Na0.2B0^, Biborate of Soda. Borax. — ^This salt is obtained in the anhydrous state
by fusing 124 pts. crystalliBed boric acid with 53 pts. anhydrous carbonate of sodium,
or by heating crystallised borax. (A process for obtaining borax on the large scale by

T T 3

646 BORON: OXIDE.

heating boric anhydride with carbonate of aodxom has been patented hf SoUer
Nor. 20th, 1843). In contact with water, it passes into the hjdnted state, and
crfstallises firom its aqii<*oas solntion, either with 6 or with 10 at water, aoeordiag to the
temperature. The former hydrate ia octahedral borax; the latter, prismatie or
ordinary borax.

Borax ia fbnnd natire in serstal localitica, txb. at Halberstadt in TransyiTaina, it
Tiquintizoa and Escapa in Pern, in the minersl springs of Chambly, 8t Om, ke.
Canada West^ but more paiticnlariy in certain aait lakes of India, Thibet, and other
partsof Asia, whence the greater part of the borax of comnierce was Ibrnieriy obtaioedL
The salt separated from these waten by erapormtion, either natural or anisted hy
artificial eontriTancea, ia sent to Enrope as ernde borax or tincal, sometimes is
large regular eiystak, but more freqnentiy as a white or yellowisb-wfaite man. vfaidi
is very impure, containing lime, magnesia, and alvmina, and likewise coYcred orer
with a greasy anbstaiiee (aaid to be added to diminish the risk of breika^ dming
transport). According to analyses by Richardson and BroweO, ends Indian bonz
contains:

Boric acid (anhydrous) . . . 23-88 40*24 24-41

Soda
Chloride of aodium
Sulphate of sodium
8alphate of calciom
Insoluble matter •
Water .

12-69 IMl 11-71

Oi» 0-11 0-21

0-13 0-49 2-81

1-36 0-«8 I'M

17-62 1-37 20itt

44-50 46-00 39-45

100-00 100-00 100-00

The purification or refining of this erode Asiatic borax has been carne<^ <m from
rery early times in Tarious seaport towns of Europe, ei^iecially at Venice, snd mora
lately at Amsterdam. Great pains hare always been taken to keep the proccsi seovt
but two methods, one with lime and the other with soda, haTO become known : — 1. The
tincal is macerated in a small quantity of cold water, and stirred abouUwith gradtuJ
addition of 1 per cent, of slaked lime, the turbid lime-water being poured cHf from
time to time, and when it has clarified, again poured upon the crystals. This trett^
meut nrmoves the greater part of the soupy compound, and the rest is deoompoaed bj
adding 2 per cent of chloride of calcium to the solution of the cmtals in hot mter.
The insoluble lime-soap thus formed, is removed by straining, and the dear liquid it
evaporated to the density of 21^ BeaumA. — 2. Tne powdered tincal is placed in s
tub with holes in the bottom, and washed with a solution of caustic soda of specific
gravity 1034, then drained and dissfdred in water, and 12 per cent, of eoda addtd
to precipitate the earths, after which the solntion is strained and erapotated. Ilie
cr^-stailisation is effected in wooden yessels lined with lead, haTing the fonn of iboit
invert^Ki cones.

The greater port of the borax used in the arts, is now prepared in France hj trett-
ing the native boric add of Tuscany with carbonate of sodium, according to a method
fin>t practised by Payen and Cartier. 1300 kilogrammes of crystallised euhosste
of sodium are dissolved in 1500 litres of water in a wooden vessel lined with ksd;
the liquid is heated to the boiling point by a jet of steam, and 1200 kilogiamiBei
of crystallised boric acid are added. The density of the solution Taries aooordiog
to the degree of purity and dryness of the boric acid used ; it ia lnt>u§^t to a oeitam
strength by adding borax or water as required, then left at rest till the imoIaUe
matters have settled down, and finally tranisferred to the dystallisinff vessels, vfaidi
arc rectangular wooden boxes lined with lead, 6 metres long, 1-7 met. wide, and 0*6 met
deep. The formation of prismatic or of octahedral borax, depends upon the deontf
of the solution, and the temperature at which the crystallisation takes plaoe.

a. PrismaticoT Ort^'nary^orax, NaHB*0« + }aq. or 2NaHB*0* + 9 a^. or Aa 0.2^0^
+ 9aq. — To obtain this hydrate, the solution, after all the carbonic aad has escaped,
should have a density of 21^ or 22<^B. (specific gravity 1-14 to 1-15), and should boil
at 1040 C. (220^ F.) It is left to crystallise for two or three days, the exystallisatioB
being finished when the thermomet^ in the interior of the v^sels stands at 2^ to
30° 0. (77° to 86<' F.) The crystals thus obtained, are freed from mother>Iiquor, then
dissolved in boiling water together with ^ of their weight of cxystallised carbonate
of sodium, to separate any remaining earths, and the strained liquid is conceotiated to
21° or 22° B. and left to oystallise as before. The mother-liquor is then drawn off
as rapidly as possible with wide syphons, and that which remains amongst the angl«s
of the cr}-8tal8 is soaked up with sponges, so that no small crystals may deposit i^o
the larger ones. The whole is then covered and left at rest for several honzH, to avoid
the formation of cracks in the crystals, which would be occasioned by the access of
cold air.

BORATES. 647

The motlier^liqaor u diluted with water and naed in a subBeqnent operation for
disaolring the boric add and carbonate of sodium. After three or four operations, it
contains a considerable quantity of sulphate of sodium ; but on cooling it to 30^ C.
(86^ F.), borax crystallises out alone, tne sulphate remaining in solution. The last
mother-liquors yield by eTaporation an impure borax, which is used in glass-making.

Oonsiderable quantities of borax are also prepared from the native borate of calcium
and sodium {BarcnatrO'CalciU\ from South America, by decomposing it with carbonate
of sodium, either in the wet or in the dry way.

Artificial borax is for the most part purer than that obtained from native tincal by
the refining process, but the crystals often contain cracks, and split when heated, in
the direction of their natural deayage, which is a great inconyenienoe when the bcurax
is used for soldering, as it causes the crystals to fly off from the surface of the metal.
This fault is partially corrected by slow recrystalusation from a rather concentrated
volution; but it is more effectually remedied by the addition of a small quantity of
tincal before recrystalHsation. (For further details of the manufacture of borax,
Bee Ut^b Dictionary of ArtSy Manufactures^ and Mints, i 379 ; Handworterbveh der
Chtrnie, 2*< Aufl. ii [2] 320 ; Pricia de Cfhimie industrieUe par A, Payen, 4>*« ed. i. 436.)

The impurities generally found in artifidal borax, are carbonate of sodium, small
quantities of sulphates, chlorides, and salts of calcium and magnesium. It is some-
tunes purposely adulterated with alum and common salt It should dissolye in about
2 pta. of hot water, and exhibit no effervescence when treated with adds. The aqueous
solution should remain perflsctly dear on addition of alkali, and when acidulated
with nitric add, should not be douded dther by chloride of barium or nitrate of
silyer.

The proportion of soda in borax may be estimated by colouring the solution with
litmus, and adding a standard solution of sulphuric acid, till a bright red colour is
produced (p. 631), and from the amount of i^kali thus determined, the quantity of
Doric add may be calculated.

Prismatic borax forms large transparent prisms, of the monoclinic system, generally
combinations of a nearly rectangular prism, haying the acute and obtuse lateral edges
truncated. The crystals effloresce in the air (according to Sims, only when they con-
tain carbonate of sodium). When heated, they melt in their water of ciystallisation,
swelling up oondderably, and solidifying to a loose spongy mass called burnt or cal-
cined borax {Boras iata)\ at a red heat, the salt fuses to a colourless anhydrous
glass of specfiic gravity 2*36, called vitrified borax. This, if pulverised and ex-
posed to the air, gradually absorbs 10 at water, reproducing ordinary prismatic Ixtrax.

fi. Borax with 6 at, water, Na«0.2B«0« + 6aq. or NaHB«0* + |aq. — Found by
Bechi in an old lagoon crater; not yet obtained artificially.

y. Borax with 5 at. water. Octahedral Borax, Na*O.B*0' + 5 aq. or NaHB*0* + 2 aq.
(or possibly NaH"B*0*). — To obtain this salt, the solution (p. 646), is concentrated
to a strength of 30^ B (specific gravity 1*246), and left to cool very slowly in a warm
place. The crystallisation begins at 79° C. (174° F.), and as soon as the temperature
of tbe liquid has fallen to 66° G. the mother^Uquor must be quickly withdrawn, because
at that temperature prismatic borax begins to eiystallise out After a few hours, the
crusts of the octahedral salt are removed and dried in the air. The crystals are
regular, transparent octahedrons, harder and less fragile than ordinaiy borax; they
have a conchoTdal fracture, and specific gravity «■ 1*8. They are unalterable in dry
air, but in a moist atmosphere, they absorb water, and are converted into prismatic
borax. When heated, they fVise to an anhydrous glass witli less intumescence than
common borax, and without splitting. On this account, octahedral borax is better
adapted than common borax for many purposes, as for soldering and as a fiux ; its
smaller proportion of water (30 per cent, that of common bwax being 47 per cent.)
also diminishes the cost of transport Neverthdess, prismatic borax is generally pre-
flerred by consumers, probably because they are used to it, and it is sold at a lower
price, weight for weight

H Anu^phouB Borax, KaHBH)' •»- aq. — Obtained by evi^rating a solution of borax
at 100° 0.

Borax is easily soluble in water, but insoluUe in alcohoL Poggiale found that 100
parts of water at various temperatures, dissolve the following quantities of prismatic
borax:

at 0° C. .

. 2*8 pts.

at60°C. .

. 27*4 pts.

. 4*6

. 40*4

. 7-9

. 67-8

. 11-9

. 76-2

. 17-9

. 119*7

and at the boiling heat, 201*4 parts.

TT 4

648 BORON: OXIDE.

The aqneons solntion htm a slight alkaline reaction, and changes the light ydlow
colour of an alcoholic aolution of turmeric to brown : on adding a small quantity of
sulphuric acid, the yellow colour is restored ; but a larger addition of sulphuric acid
sets the boric acid uee, which then produces the peculiar red-brown oolonnng already
mentioned (p. 639).

Borax is easily decomposed by acids. Etcu water, when present in oonsidenLble
quantity, abstracts part of the base, so that a dilute solution of add borate of sodium
reacts uke a mixture of boric and the neutral borate, or eyen free soda, giring, for
example, a brown precipitate with silver-salts (p. 641). A solution of borax erapo-
rated with excess of hydrochloric acid leaves a mixture of chloride of sodium and free
boric acid. It also absorbs carbonic acid when exposed to the air, or when the gas is
passed into it, and on adding alcohol to the liquid, when saturated with carbonic add,
no borax separates from it. A solution of boric add saturated with sulphuretted
hydrogen, and mixed with alcohol, separates, on addition of ether, into two layen^ the
lower containing sidphide of sodium, the upper free boric add.

Borax forms with many of the weaker adds, double salts in whidi the boric add
appears to act as a base to the other add. Thus, with anenioua add it forms a com-
pound whose empirical formula is 3NaK>.6BK)*.6As*O*+10aq. It unites also with
fluoride of sodium (see p. 633). When 1 at tartaric acid is mixed in solution with
2 at. borax, boric add separates out on cooling ; if the quanti^ of tartaric add be
gradually increased, the Quantity of boric add separated likewise increases up to a
certain point ; but beyona that it diminishes, and at last no further separation of boric
acid takes place. Here also the boric add seems to play the part of base towards the
tiirtaric aad (see Tabtbates). Aeid tartrate of potassium also forms a doable salt
with borax. Of silicic acid, a solution of borax dissolves but a mere trace.

Benzoic, tannic, and gallic acids dissolve in borax-solution more readily than in
waiter. Many insoluble substances, e,ff. stearic and other fatty adds, eoiophon^^
shellaCy and other resins^dissolvB in borax-solution as readily as in weak alkaline leys,
the solution acting in fact iust like a mixture of boric add and free alkalL

At a red heat^ on the other hand, the boric acid in borax readily unites with and
dissolves metallic oxides, forming frisible double salts : hence the great use of borax
in metallurgic and assaying operations, and for soldering. The compounds thus
formed often take the form of transparent glasses of various colours, affording yerj
characteristic and delicate tests for tne several metals : hence the use of borax in
blowpipe analysis. It is also used in the formation of easily fusible glass fluxes for
enameb and glazes. An enamelled coating for cast-iron vesseLi is made by first fusing
on the surface of the metal, a mixture of quarts, felspar, day, and borax, and then
covering it with a glaze containing borax. A glazing of 1 pL day, 1 pt. felspar, and
2 pts. l^rax is also used instead of lead-glszing for stone-ware.

Borax is likewise used, though not to any great extent, in medicine, dther directly
as a remedy, external or internal, or for the formation of pharmaceutiosl preparations,
such as tartarised borax.

c. Tctrametaborate of Sodium, NaH"B*0* + }aq. — Produced by boiling 2 at.
borax with 1 at. chloride ti ammonium, as long as ammonia continues to escape:

2NaHBK)* + NH*a - NaHWB*0« + KaQ + NH».

It separates from the filtrate by slow evaporation in milk-white, transparent, shining;
hard crystalline crusts ; dissolves in 6 to 6 pts. water of mean temperature, forming an
alkaline solution ; yields a predpitate of boric acid on addition of a dilute add, whereby
it is distinguished from borax ; melts when heated, with less tumefaction than ordinary
borax. (Bolley, Ann. Gh. Pharm. Ixviii, 122.)

d. Pentametaborate. NaH*B*0^ + |aq. — Prepared by dissolving 1 at. borsx
and 3 at. boric add in hot water, and separates from the solution in small aystais
aggregated in roundish masses ; they do not suffer any loss of weight at 100^ C, and
give off their water of crystallisation but slowly at higher temperatures. The salt
to which Laurent assigned the empirical formula Na**B^'* + 66aq. is perhaps this
pentaborate.

e. Hexmetahorate, NaH*B*0".— Kot yet obtained in the solid form, but periiapa
contained in the solution produced by mixing 3 at. borax dissolved in water with 1 at.
sulphuric acid :

3NaHBK)« + H^O* - Ka«SO* + NaH»B^'«.

This liquid thus formed does not redden litmus ; but if 1 at. more of sulphuric
sdd be added, all the boric acid is set free, and the mixture exhibits the wine-red
colour thereby produced, which, however, another drop of sulphuric acid immediately
changes to bright-red (Laurent, Ann. Ch. Phys. [2] Ixvii. 218). The hexbotata

BORATES. 649

is periiaps abo formed when aqneons borax is mixed with boric acid till the liquid no
longer exhibits a basic reaction. This solution is said to yield by evaporation
tabular crystals, having a cooling taste like nitre, a neutral reaction, and giving o£f 30
per cent* water when melted. (Tiinnermann.)

Borate of Sodium and Caloiutn, NaCaH^^O* + 9aq.— Such, with addition
of 1*9 per centw chloride of caldxmi, is, according to Helbig (Chem. Centr. 1858, p.
494), the composition of a mineral from South America, Imown in commerce as
'* borate of lime," and forming irregular nodules, mainly composed of a net-work of
translucent crystals. Stein re^trds it as identical with the hyarobcax>calcite of Hayes
and the boronatrocalcite {q.v,) of XJlex.

Borate of Sodium andMagneeium, NaMg^H'B*©'** 14aq. (Rammelsberg).
— Separates by spontaneous evaporation, from a mixture of the cold aqueous solutions of
borax and sulphate of magnesium, in large, shinine, efBorescent, monodinic crystals.
It dissolves in cold water, forming an alkaline solution which is not precipitated by
ammonia, but becomes turbid when boiled, clear asain on cooling. If the liquid, after
boiling for some time, be quickly filtered, the residue consists of basio borate of mag-
nesium.

BoRA^m OF Stbonttitk. 1. Orthoborate^ Sr'BO*. — Obtained by heating boric
anhydride to redness with excess of hydrate or carbonate of strontium. (Bloxam,
Chem. Soc. Qu. J. xii. xiv. 142.)

2. Metaborates. — ^The monoborate has not been obtained. Strontium-salts, pre-
cipitated by borax in the cold, yield a precipitate, which when pressed between paper
and dried at 100° C, has the composition Sr^'BK)** + |aq> gives off 2 at water at
200^, and the rest at 300°, and is partiidly decomposed by hot water, the residue pro-
bably consisting of the sesquiborate, Sr'HB'O*.

The dimetaborate, SrHBK>« + |aq. (at 100° G.), is said to be precipitated from boil-
ing solutions of borax and chloride of strontium. It has an alkahne reaction ; dis-
solves in 130 pts. of pure water, more easily in presence of ammoniacal salts ; gives off
3 at. H as water at 280°, the remaining atom at a red heat, leaving the anhydrous
salt Sr«Br*0' - Sr*0.2B»0» (« 2SrHB«0*-HK)).

The t^trametaborate, SrH'B^O' + { aq. is obtained, according to Laurent, by boiling
the preceding with excess of boric acid, and evaporating the fUtrate. Pentaborate
of potassiimi also precipitates strontium-salts, but the precipitate has not been
examined.

BoBATB OF 2^iNa — Sulphate of zinc, precipitated by borax in the cold, yields a pre-
cipitate consisting chiefly of f7U7no6ora<« of zinc, ZdBO*, which, however, is decomposed
by washing with cold water, leaving a basic salt » 4ZnB0^6ZnHO + 2aq. (at 100° C.)
A solution of a zinc-salt, mixed at the boiling heat with borax and boiled for some
time, yields a precipitate consisting of a similar basic borate, mixed with basic sulphate
of zinc

Boric Ethers,

BosjiTES OF AmrL. a. Orthoborate. (OH")"B0* (Ebelmen and Bouquet^
Ann. Ch. Fhys. [3] xviL 61). — Produced by the action of chloride of boron on amylic
alcohol :

3(C*H».H.O) + Ba» = 3HC1 + (C»H»)«BO».

When vapour of chloride of boron is passed into amylic alcohol, hydrochloric acid is
evolved, and the liquid quickly separates into two layers, the upper of which, when
decanted and distilled, passes over almost wholly between 260° and 280° C, and when
again rectified, yields pure tri-amylic borate. It is a colourless, oily liquid, having a
specific gravity of 0*87 at 0° C, and a faint odour like that of amylic alcohol ; it bums
with a green-edged flame, and boils between 270° and 275° C. Vapour-density, by
experiment, «i 10*65 ; by calculation (2 voL) » 9*45. Water decomposes it, yielding
boric add and amylic alcohoL

b. The metaborate of amy I, C*H"BO*, has not yet been obtained.

c Aeid borate, 2C*H»B0«:B«0« or (C»H»»)H).2BH)« (Ebelmen, Ann. Ch. Phys.
[3] xvi 139X ia obtained by pouring 2 pts. of amylic alcohol on 1 pt of boric anhy-
hydride, heating the mixture to about 180° C, exhausting it with anhydrous ether,
distilling off the ether from the decanted ethereal solution, and heating the residual
lii|uid to 250 — 270° C, to free it from fusel-oiL The acid amylic borate thus ob-
tained, is a clear, slightly yellowish liquid, having an odour like that of fiuel-oiL It
may be heated to 300° C. without alteration, but is decomposed at higher tempera-
tures. It bums with a green flame.

When fusel-oil is heat^ to 300° C. with excess of boric anhydride, a colourless liquid
over, which smells like amylic alcohol, and begins to boil below 100° ; but the

650 BORON: OXIDE.

boiHofi point riBeR quickly, and there remains a Titreoas maaa^ reBembling fhe add «tber.
As acid borate of methyl gives off oxide of methyl by dry distillation, it is probable
that the lighter products of the distillation just mentioned contain oxide of amyl

Borates OF Ethyl, a. Orthoborate, {C*H*)"BO*. (Ebelmen and Bouquet;
Ann. Ch. Phys. xvii 55 ; Bowman, Phil Mag. [3] xxix. 646.)— Prepaied like the
corresponding amyl-compound. Vapour of chloride of boron is rapidly absorbed by
absolute alcohol, the liquid becoming hot and separating after a while into two lajefs,
the lower of which is merely alcohol containing hydrochloric add, while the upper
contains the tri-ethyUc borate, which may be separated by distilling the deeuted
liquid, with addition of a little alcohol, collecting that which passes OTer between
1 15^ and 125^ C, and rectifying. It is likewise produced by dIstUling a mixtaie of
dry ethylsulphate of potassium and anhydrous borax. (H. Kose, Pogg. Aim. zcriii.
245.) See also vol. ii- p. 628.

It is a colourless, mobile liquid, having a peculiar, agreeable odour, and buniog
bitter taste. Specific gravity 0*885. It dissolves in all proportions in alcohol and
ether, mixes with water, but is decomposed thereby in a few minutes, with separttion
of boric acid. Boiling point 119° C. Vapour-density (by experiment) =614; by
calculation (2 vol.) « 5 07. Bums with green flame, giving off white ^unes of bone
acid, and leaving no residue.

Metahorate, or Neutral Borate, CBPBO*. —Produced, with sepsiation of boiie
acid, by the action of alcohol on the acid borate :

2C«H*B02.B«0» + C«H».H.O « 3C^».B0* + HBO«.

Add borate of Alcohol. MeUborela Boric

ethyl. of ethyl. add.

When the ffyrupy acid ether is mixed with absolute alcohol, boric acid aepante^
with considerable evolution of heat, and on separating the liquid therefrom by decui-
tation and pressure, and heating it for a while to 100^ C, boric acid is again deposited,
and there remains a colourless mobile liquid, which resembles the ot&obor^ ud
yields by analysis 32*93 per cent earbon and 6*97 hydrogen, the fonnula reqaiiing
33-38 C, and 6*96 H. (Handw. ii. [2] 809.)

Acid BoratM. 2C«H*B0».B«0» «- (C«H»)«0.2B«0». 5iaorafoo/JEWy/(Ebelmen,
Ann. Oh. Phys. [3] xvi. 129.) — ^Produced by the action of boric anhydride on aleohoL
When finely pulverised boric anhydride is mixed with an equal quantity of abeolute
alcohol at 18^ 0. the mixture becomes hot, quickly attaining the temperatme (A 50°,
and begins to boil when heated to 95^. If the distillation be interrupted as soon as
the bomng-point rises to 110^, the distilled portion poured back, and the distillation
repeated till the boiling-point again rises to 110^, acid borate of ethyl remains in the
retort, mixed with bone acid, &om which it maybe separated by digesting the reeidoe
for twenty-four hours with aubydrous ether, decanting m)m the undii»olved porlios, and
distilling till the heat in the retort rises to 200^. Add borate of ethyl then remaiDS
in the form of a thick yellowish liquid, which gives off white fumes in the air at 200°,
and solidifies on cooling to a transparent glass. This glass is rather soft, even at
mean temperatures, and at 40^ or 60° may be drawn out into long threads It has a
faint ethereal odour, a burning tiiste, and blisters the skin, being at the same time
converted into a white powder of boric acid. It gave by analysis, 19*8 per cent C,
4*4 H, and 66*7 B«0», the formula requiring 22*5 C, 4*7 H, and 65*3 BK)».

Acid borate of ethyl begins to decompose at 300° C. with fusion, intumescence^ and
thickening, the products being ethyloie-gas, alcohol-vapour, vapoor of the undaeom-
posed ether, vapour of water, and fused boric anhydride free from charcoal. The
ethylene-gas burns with a green flame, the oolonr arising from admixed boric ether,
which, however, may be removed by washing tbe gas with water.

The acid ether becomes veiy hot by trituration with water, beinff resolved into
alcohol, and boric acid. Exposed to moist air, it becomes white on the snz&ee ftom
slow decomposition. It dissolves in alcohtd and in ether, but gives off these liquids com-
pletely at 200° C, a portion of the undecomposed boric ether then paasug ayet with tiie
alcohol so that the distillate bums with a green flame, and when imxA with water
solidifies from separation of boric acid. The syrupy acid ether treated with abeohite
alcohol in the manner above described, yields tne neutral borate of ethyl.

B0RA.TB8 OF Mbtetu — a. Orthoborate, (CBFfBO* (Ebelmen and Bouquet» inn.
Ch. Ph^s. [3] xviL 59.) — ^Produced by the action of chkride of boron on anhydroni
niethyhc alconol ; purified by rectifying the upper of the two resulting layenof Hqiiid.
It is a colourless mobile liquid of specific gravity 0*955 ; has a pungent odour some-
what like that of wood-spirit ; boils at 72° C. Vapour-density - 3*66. I>issolTes
in alcohol and ether, is quickly decomposed by water, and bums with a green flame.

b. Acid Borate2CW1^0\BK)* « (CH»)«0.2BK)« (Ebelmen, Ann. Ch. Phys. [S]
xvi 137.) — Obtained, like the acid ethylic borate, by treating boric anhydridie with

BORON: SULPHIDE — BR AGITE. 651

anhydrouB methylic alcohoL The mass is repeatedly heated to 110^ C, the distillate
beine each time poured back, the residue is treated with ether, and the decanted
solution heated to 200^. Acid borate of methyl is 'thus obtained as a vitreous
mass, soft and tenacious at ordinary temperatures. It bums in the air with a
beautiful green flame ; is decomposed by distillation into boric anhydride and oxide
of methyl ; and by water, into boric acid and methylic aloohoL

MQMOiMf flmbPHXna OV« B'S*. — This compound, which is the analogue of
boric anhydride, is formed by igniting boron in yapour of sulphur (Berselius, Pogg.
Ann. ii. 145) or in sulphuretted hydrogen; also by heating boron with sulphide of
lead (Wohler and Deyille, Ann. Ch. Pharm. cv. 72), or by heating a mixture of boric
anhyoride and charcoal in vapour of sulphide of carbon (Fr^my, Ann. Ch. Phys.
[3] xxxriii. 819X or by stronjdy heating a borate in yapour of sulphide of carbon
(Skoblikoff and Budloff; Petersb. Acad. BulL xii. 319). To obtain apure product,
boron is heated in sulphur yapour as long as that vapour continues to be absorbed by
it. The action is slow, because the sulphide forms a crust round the boron.

Pure sulphide of boron is a white solid body, sometimes amorphous, sometimes
crystalline. It has a pungent sulphurous odour, like that of chloride of cyanogen,
or chloride of sulphur. Its vapour attacks the eyes. By itself it does not appear to
be volatile, but it volatalises in sulphuretted hydroeen, like boric acid in vapour of
water. Heated in a stream of hydrojgen, it melts, and gives off a little sulphur, perhaps
however, only when not quite pure. It decomposes water with great energy, forming
boric and sulphydric adds, a decomposition to which, as already observed, the formation
of boric acid in the Tuscan lagoons has been ascrib^

There appears also to be a persulphide of boron, produced by heating boron in
sulphur-vapour till it takes fiA, and then leaving it to cool in the vapour. When the
product thus obtained is thrown into water, boric and sulphydric acids are formed, and
milk of sulphur is deposited. (B e r z e 1 i u s.)

BOMVATSOCA&CZXa. KaCa<H^O" + ^ aq. — Native borate of calcium
and sodium, called also Hydroboraeite, Hayesin, an^ Tiza. (See Bobatbs of Sodiuu,
p. 649.)

BOTRTO'CIMH'. Hed vitrioL — ^A native ferroso-ferric sulphate from Fahlun in
Sweden, occurrlnff rarely in small oblique rhombic prisms, having the lateral faces
inclined to each other at an angle of 119^ 56', and to the terminal faces at 113^ 37'; more
frequently massive and as a deposit on gypsum, sulphate of magnesium, ferrous sulphate,
and iron pyrites. Translucent, with vitreous lustre. Dark hyacinth-red to ochre-yellow,
Harder than gypsum. Specific gravity 2*039. Swells up before the blowpipe, giving
off water and leaving ferric oxide. According to Berzelius, its formula is 3Pe^0.2SO'
+ 3(1V0«.2S0*) + 36H»0.

BOT&TOUns. Chavx boratie silicieuse eoneritionie. 2CaB0*.Ca*SiK)* + 2 aq.
— A kidney-shaped mineral of delicate fibrous texture, found in the veins of magnetic
iron ore at Arendal in Norway ; generally as a deposit on crystals of calcspar. Its
formula is the same as that of iatcmte, but with twice the amount of water.

BOV&AVOnUTB. A tribasic sulphantimonite of lead, 3Pb<S.Sb<S> or ^1bPb*S\
found at Moli^res in France, in Lapland, and other localities. Crystallo-laminar or
fine-grained. Bark lead-grey. Specific gravity 6*69 to 6*97.

Schiwarzspiessglanzerg. Antimoine jpitombo-cuprifhe : 2Pb'S.

Cu'S.Sb*S* » SbPb*CcuS'. — Crystallises in rieht rectangularprisms of dark steel-grey
colour, with metallic lustre, and yielding a buck powder. Hardness equal to that of
calcspar. Specific gravity 6*7 to 6*8. Melts before the blowpipe, giving off white
fames, covering the charcoal with oxide of lead, and changing to a slag containing a
laree quantity of copper. It is found in the copper mines of Cornwall, at Neudorf
ana Andreasberg in the Harz, at Kapnik and Offenbanya in Transylvania, &C., but is
not very abundant. Some varieties found near Freiberg contain silver to the amount
of about 0-12 per cent (Gm. v. 486.)

80VJBI COA&. A kind of coal of a brown or brownish-black colour and lamellar
texture, the lamime being often fiexible when first dug out, but eenerally hardening by
exposure to the air. It consists of wood penetrated with petrmeum or bitumen, and
frequently contains pyrites, alum, and protoeulphate of iron. By distillation, it yields
a fetid liquor mixed witli ammonia and an oil partly soluble in alcohol. It is found
in England, France, Italy, Switzerland, Germany, Iceland, &c.

BO W jMi I'iriL See Sirfbntxnb.

ro BIQiros. Manostdpkide of Ammonium (p. 193.)

A mineral found at Arendal in Norway, but not yet sufficiently ex-
amined to establish its separate identity. (Forbes and D ahll, J. pr. Chem. Ixvi 446.)

652

BRAIN — BRANDT.

See NncTOus Tissub.

V. Son. Kleie, (Millon, AiiilCIl Fhjs. [31 xxri 6. Paigot^t&O.
5. K^kul^ liebig's chem. Briefe, 3 Anfl. i. 695. Wetzel and Yan Hees, AidL
Pharm. [2] Ixvii. 284. Foggiale, Compt rend, zzxrii 171 ; xlix. 12& SigK
DingL poL J. cxxxL 298. Monriis, Compt. rend, xxxvii 361; zlTii. 505;ilTiiL
431. Ondemans, Kep. chim. app. i. 686.)~The husky portion of gromd ooni,
separated by the bonlter from the flour. The analyses which have been made of it|
even from the same kind of corn, differ widely in the proportion of some of tkeoMo-
tial constituents, as the following table will show.

A«h

W«t«

Fat

N troirenoui matter (gluten, fte.) .

Drxtrin

Stanh

Siifrar

Celluloie ......

Resinous and odorlferoas matter

Nitrogen

££

Whtai*rmu

Onde-

ft«W.

KitaM.

UWm.

3-35
14-55

1*86
14*50

7*79
3819

21*86

6-52
14*07

2-46
13-46

5*52
26-11

80-80

6-26

14*27

2*88

12*68

5*24

29*74

27*11

4-99
14*40

3*88
16-41

8-71
29*31

25*98

5-6
12-7

2-9
13*0

7*9
21-7

1*9
34*6

56
13-8

4-1
67-1

u-i

9^7
!•«

101-59
2-23

98*94
207

98*28
1*95

99 68
2*37

100^

1041

K^kuU's determination of the nitrogenous matter is probably too high. The 13-0
per cent, nitrogenous matter found by Poggiale was made up of 6*6 soluble mttter
(albumin), 3*9 insoluble, but capable of assimilation, and 3*6 insoluble and incapable
of assimilation. Poggiale isolated the cellulose by rendering the starch soluble with
diastase ; he finds that the usual process of determination by the successiTe use of arids
and alkalis, always giyes the amount of cellulose too low, part of it being conrerted
by those reagents into sugar and dextrin.

Bran, though rich in nitrogen, appears to possess but little nutritiye power. Animals
fed upon it quickly lose flesh (Poggiale). It contains a nitrogenous principle called
cerealin, analogous to diastase, and perhaps identical therewith, whicb possesaes the
power of quickly conyerting starch into dextrm and sugar. Mouri^ found that 1 30 pti
of wheaten bread containing bran easily difiused through 620 parts of water ▼bi'n tri-
turated therewith, and yielded 69*36 pts. of soluble and 69*76 pts. of insoluble matter,
whereas the same quantity of bread not containing bran, was oonyerted bj tritontion
with water into a semisolid mass, and yielded only 9*03 per cent soluble mstter to
120-26 insoluble. This action of the bran on the flour eommenoes in the kneading
and baking, but is completed only in the stomach. (See Bbbad.)

Bran is used by calico-printers in the clearing process, for remoying the colonring
matters adhering to the non-mordanted parts of the maddered goods, as well as the dns
matters which doud the mordanted portions. (See Ur^s Dictionary qf ArU, Maw-
facturefj and Mines, L 383.)

BBJUrCKXTB. (>H>*. — A fossil hydrocarbon from the lignite of Mount Vaso is
Tuscany. It is colourless and translucent, like Scheererite ; melts at 76° C. bat does
not crystallise on cooling. It dissolyes in alcohoL Specific gratitj » 1*00. (SitIi
Leonhard and Bronn's Jahrbucb, 1842, p. 459.)

BSAWBXBITB. See CuNTOinTB.

BBAnT. This well known liquor is the spirit distilled from wine, >^ J^
an extensive article of trade in the south of Europe. It is generally mann&ctnred
from white or pale-red wines, but often from inferior articles, such as the refuse wine
and the marcs of the wine-press. Distillation of the wines is the only process neeo-
sary for procuring brandy : hence the richer the wine in alcohol, the greater will be
the yield of brandy. Many circumstances, however, independent of the manufBCtare, id-
fluence the quality of the product. Thus, white wines do not always afibrd more alcohol
than the red, but they yield a spirit of finer quality, because they contain more of the
essential oil of grapes. Wines which have a certain taste of the soil, communicate it
to the brandy derived from them by distillation ; thus, the wines of Selleul in DiujAin*
give a brandy which has the odour and taste of the Florentine iris; tboaeofSLmn
in Vivarais, give a spirit which smells of the violet, and so of many other Tineties.

B^al Cognac is obtained from the distillation of choice wines, ereiy attention bring
paid to the proper degree of cleanliness in the various utensils empIoyedL In the im-
proved form of still, a very superior article is obtained from inferior wines, bnt the
small proportion of essential oils in such wines divests the brandy of that arofflstie

BEASS — BRASSICA, 653

flxTOur which belongs to the bettor sorts of wine, and is oommimieated to the brandies
procured from them. An inferior brandy called eau-de-vie de marcs is obtained by dis-
tilling the dark red wines of Portugal, Spain, and other wine-growing countries, also
the leea deposited by wine in keeping, the marc or refuse of the grapes from the wine-
press, the scrapings of wine-casks, &c

Brandy, as sold in France, is generally of two strengths, designated as a preutfe de
HaUande, and dpmtoe tFkuile, the former yaiying from 18^ to 20^ Beanm^. The
st3t>nger liquors are valued according to the quantity of eau devu a preuve de Hollands
that a given quantity will furnish on the addition of the proper quantity of water.
These strengths are usually twelve, viz. of five-six^ four-fivet three-four^ two-three,
tAree-five,/our-sepen, five-nine, six-eleven, three-six, three-seven, three-eight, and three-
nine, but the last is rarely made. The meaning of these strengths is as follows : — If
a spirit he five-six, 6 pts. of the Bpirit will give a liquor a preuve de HoUande, when
added to six measures of water. The spirit five-six has a specific gravity of 0*9237 or
22^ Bm. ; but all the other strengths are variable, on account of the uncertainty of
the strength of the spirit i preuve de Holland,

The following is an average of the yield of brandy which some wines afford by dis-
tillation:

1000 litres of wine of St. Gilles, in the environs of Montpellier, afford

of three-six brandy 160 litres

„ of good wine of calcareous soils 140 „

„ of wines of fertile soils near Montpellier . . . 100 „

„ of wines of soils producing much grapes . . . 100 „

Wines of the countries nearest the Mediterranean furmsh the largest proportion of
brandy, which diminishes as the grapes grow in more northern countries.

British brandy is an artificial product fUbricated by the rectifying distiller. The
following receipt is given bv Ure : — " Dilute the pure alcohol to the proof pitch, and
add to every hundred pounds weight of it from half a pound to a pound of argol — crude
tartair — dissolved iu water, some bruised French plums, and a quart of eood cognac.
Distil this mixture over a gentle fire in an alembic provided with an agitator. The
addition of brandy and argol introduces osnanthic ether, and if a little acetic ether be
added to the distillate, the whole imparts the peculiar taste of genuine Cognac brandy.
Colour with burnt sugar if necessaiy, and add a little tannic acid to impart astrin-
gency." (See Ur^s Dicticmary of Arts, Manufactures, and Mines, i. 389; also Mus-
pratfs Chemistry, L 103.)

MWLMLMBm An aUoy of copper and zinc. (See Coffbb ; also Ur^s Dictionary of
Arts, Manufactures, and Mines, L 399.)

BKA88ICA. A genus of cruciferous plants, including some of the most impor-
tant fodder plants and culinary vegetables, viz. the cabbage, rape, and turnip.

1. Brassica oleracea. Cabbage. — Of this species, many varieties are cultivated for
their leaves, e,y, the common red or white cabbage {Br. ol. capitaia), the Savoy cabbage
(Br. ol, btdlata), curled kale (Br. ol. acephala), ccc The turnip-stemmed cabbage, or
kohl-rabi (Br. ol. caulorapa or napoorassica), is much cultivated in France and
Germany for its fleshy turnip-like stem or bulb, which makes an excellent vegetable
dish. Cauliflower and broccoli are also varieties of Brassica oleracea.

Fresh white cabbage-leaves contain 0*2 per cent, nitrogen ; the dried leaves 3*7 per
of^t. (Boussingault, Ann. Ch. Phys. [2] Ixviii. 337). Table A exhibits the compo-
sition of cabbage leaves as determined by Anderson (Chem. Centr. 1866, p. 232). —
a. Of tile young plant before the heart-leaves are formed, b. The outer leaves of
perfSectly ripe cabl^ge. c. The heart-leaves of the same.

Tablb a — Composition of Cabbage-leaves.

Albuminous substances •
Woody fibre, gum, and sugar .

Ash

Water

According to Sprengel (J. techn. Chem. xiii. 486), white cabbage contains, in the
air-dried state, 62*6 per cent, water, 19*3 per cent, matter soluble in potash-ley, 26*6 per
eent. woody fibre, besides wax, chlorophyll, &c The ash of cabbage has been analysed
hy Way and Ogston (Joum. Roy. Agr. Soc vii. [2] 693; xi [2] 612), by Sprengel
and by Stammer (Ann. Ch. Pharm. Ixx. 294).

The fleshy stem or bulb of the kohl-rabi contains, according to Sprengel (loc. cit.)
01 per cent, water, the leaves 86 per cent, water. 100 pts. of the dried substance con-
tain 41*4 pts. soluble in water, 38*2 soluble in potash-ley, 18*6 woody fibre, besides

2-1

1*6

0-9

4*6

6*0

1*6

2*2

0*6

91*8

91*1

94*4

654

BBASSICA.

wax, &t» &e. The ash of the conns sad leayes has beea analysed hj Sprengel, and
by Way and Ogston {loe. cii.)

The ashes of the heart of eimliflower (Br, cl. yar. hobrytu cauUfara), and of the zoot
and leaves of brocooli {Br. id. var. botrytis asparagoides) hare been analysed by
Th. Bichardson, Ann. Ch. Pharm. Ivii. ; Anhang zum dntten Heft).

Tablb B. — Ash of dijfereni Varieties ofBrasnca deraeeeu

Ash tn 100 0tB. of freth plant
- .drUd

"at lOo'' C.

•tr.
plaota di

>lai«C
ed

Compoaitioii ofaah In 100 pts.

Potaah (anhydroiu}
Soda

Lime

Magnetia . . .

Alumina ....

Ferric oxide . .

Su phuric anliydiide

Silicic „

Carbonic „

Pbospborie „

Calcic, magnetic, and ferric

phospbatcj . • .
CMortde of potatsiom

M ,. aodium .

W»j«Dd0t«an.
On«CaU«|f»

Lmtci.

O-T

10^

4<W
a-4

150
2*4

9'8

7'3

10-6

16-7

ia*6

trace

Sudk.

mUtCahtaga

l-t

^ T'A5

40-9
40

196
3*8

0-4

ll-l

1*0

6'3

19^6

2-1

31-3

I•^0

93*1

0-3

0-2

0-1

12-7

2-8

10*4

11-62

4S-8

ire

8*3
0*4

16^

War

7-06

37'6

13-3

11-1

4-0

O-A

0-5

12-6

6-7

6-1

121»

17-8
8-1

84-2
32

0-2

14-G

7-1

5-4

0^5

8-09

36*3
2-8

2-8

0-4
tl-4

0-8
10*2
13-6

11-9

Lc««.H

IS-M

9-3

so-s

8-6

55
10-6
9-6
9-0
9-4

6-0

e-7

071

47-16

4*70
893

11-16
1-92

2ar84

»67

278

1-01

170

84-29
14 79

2-96

10 3-<^
0(<9

24-89

2-12

6 22

trace

2210
7a5

26-4-1
3-43

ifrie,
lei

6-!!

2. BrasHca Naptcs, — "Winter Tape, Coleseed, and Br. eampestrit var. oleifera.
Summer rape, Golzat or Colza, are cultivated chiefly for their seeds, which yield
a large quantity of oU, and for the succulent food which their thick fleshy stems and
leaves supply to sheep when other fodder is scarce. The cake which remains after the
oil has been pressed from the seed, is used on the continent as food for cows and pigs,
and aLso as a manure, for which purpose large quantities of it are imported into Eng-
land. Colza or summer rape yields the largest quantity of oil, but wmter rape is said
to be hardier, and is therefore more generally cultivated in this country. Way (Journ.
Boy. Agr. Soc. z. part 2) found, in 100 pts. of the dry seed of dwarf rape, 4-2 per cent
nitrogen, 37*8 &t, 3*3 ash, and 6 '6 water. Of the ash of the seed and straw of rape,
numerous analyses are given in Liebig and Kopp's Jakresbericht der Ckemie for 18<49,
tables D and £ to page 656. From uiese we extract the foUowing :

Tablb C. — Aah of the Seed and Straw ofBraatiea Naptu.

Liebig.

Erdmann,

VTe

*»r.

Aah in 100 pts. ofalr-drted plant

Seed.

Seed*

Seed.

scnv.

1-89

8-41

„ „ « plant dried at lOOO C. . .

5 19

403

4-44

Composition ofaih in 100 pts. t

Potash .

22-5

227

26T

S8-9

24-9

Soda

0-2

6-5

Lime

11-8

14-6

13 2

178

82-8

Mngnesia

11*1

120

11-6

I.V»

Ferric oxide

©•6

0-7

Sulphuric anhydride

Silicic „

1*1

9-0

4-1

Carbonic „

147

Phosphoric „

39-1

47-0

41-6

4-5

Chloride of potassium

—

— .

2-1

„ sodium

0*8

*■"

3. Brassica Rapa, the common white turnip, and Br, campestris var. rutabt^a,
or napobrassica, the swede turnip. — The ashes of these plants have been examined
by T. J. Herapath (Chem. Soc Qu. J. ii. 14), Eggers (Jahresber. d. Chem. 1849,
p. 656); Baer {ibid, 1851, p. 710); Stammer (Ann. Ch. Phaim. Ixx. 295); and Way
and Ogston {foe, cU,),

BRASSIC ACID — BRAZIL WOOD.

655

Table D.-

— Composition of Turnip-ash.

ftcn|Mth*

Way andOislaB.

Bwrr.

Suonmv.

Eggan.

Oil-
caka.

Stmdt

WUU

' ami*

DaUfiBj/Md

Aih In 100 pts. of freth

Bulte

Bolbc.

Bollw.

Lcavffs.

Bttlbc.

Leasts.

BaUa.

Laavw.

Baad.

Saad.

Straw.

Bnlba.

PMDt .•■•■•

1-S

0*65

076

1-97

1-09

119

959

1-82

8*67

0-46

5-70

Ash la 100 pta. of air.

dried plaac . . . .
i»h to 100 pts. of plant

...

— .

4-58

4-41

drifd at 100» C. . .

—

diio

16-40

841

10-80

7-40

15*20

8-98

—

7D0

613

CoBpwttioo of the ath

in 100 pu. :

Potash

GS-6

47-9

»-7

1116

86-9

13-5

48-5

12-7

21-9

161

16*5

46-5

21-9

Soda

trace

14-7

19-4

8H)

4 6

I'l

1-3

Una

6-9

11-8

2K-6

6-6

35-1

6-7

28-7

17-4

11-3

25-4

131

8-6

Magnctia

a*4

3-8

2-6

2-5

1-7

2-3

2*8

8-7

10-4

11-0

1-6

14-7

Alaa»lna

trara

«i>

•^

•M

—

Ferric oxide. . . .

0-ift

trace

O-ft

0-6

0*8

1-9

1-0

1-2

Siilp'- uric anhydride .

161

lfl-4

11-7

6-7

12-8

7-8

7-9

6-5

9-9

1-6

Stlioc

0-1

J-7

1 2

2M)

0-7

9-9

3-4

13- It

Ctrtioole n

_•

10*7

12*6

1 8-8

14-8

14-6

6-9

27-6

2-1

Photphorfc

I5«

16*6

9-1

4-9

8-8

4'6

7-6

3*1

40-1

34 0

4-0

l5-5t

82-7

Chloride of potaasium

J7.

—

15-5

—

10-6

(t todioin

14*6

12*4

10-0

180

5'4

10 7

■~

0-8

3-2

—

0-6

Colza oil is, according to Websky (J. pr. Chem. IviiL 449),
a mixture of two glycerides, which yield by saponification, bras sic acid, which is
solid at ordinary temperatures, melts between 32 and 33^ C, and crystallises £pom
alcohol in long needles ; and another acid, which is liquid at ordinaiy temperatures
and resembles oleic acid. The two acids are easily separable by means of their lead-
salts, the salt of the oily acid beine soluble in ether, while brassate of lead is insoluble.
Websk^ assigns to brassic acid the formula C**H^O*. Stadeler (Ann. Ch. Pharm.
Izzzrii. 133) proposes C**H**0*t or C**H^", which agrees ouite as well with the
analyses, and is the same as that of erutic acid, extracted by Darby from oil of
mustard. Brassate of sodium giyes by analysis 8*5 per cent, soda; the formula
(?*H"N«0* requires 8-6 per cent

Natiye sesquioxide of manganese. See Makoamesb.

The German name of peroxide of manganese.

EO A (K u n t h), or Hagenia abyssiniea (Lamarck).
— The £owen of this plant, called Kusso or Kosso, contain, according to Viale and
Latin! (Correspond. Scient. in Koma, Not. 1862), a peculiar acid, hagenio acid, in
combination with ammonia.

Harms (Arch. Pharm. [2] Ixxxriii. 166) found in 100 pts. of the ash of kusso,
after deducting sand and charcoal :

CO* SO* P»0» SiO* Pe*0«.P"0» NaQ

13-58

1-90

14 43

814 •

6-60

7-88

A1*0»
1-97

Mg»0
6-48

Ca«0
13-37

Na«0
13-41

18-89

Mn»0«
traee

IVOOOa The tree which yields this wood, the Cmsalpina crispa, grows
in Brazil, and also in the Isle of France, Japan, and elsewhere. There are several
-rarietiea, distinguished by the names of the localities from which th^ are obtained, as
Pemambuco, Lima, Santa Martha, Sapan (from Japan), &c. Pemambuco wood
and Lima wood contain the largest amount of colouring matter ; -nz. about 2*7 per
cent. ; Sapan wood, only about 1*5 per cent. Peach or Nicaragua wx)od,«Bometimes
called Santa Martha wood, is still inferior in point of quantity, but is preferred for
some purposes.

Brazil wood is heavier than water, very hard, and susceptible of a good polish.
Its colour is pale when newly cut, but becomes deeper by exposure to the air. The
heaviest specimens generally jrield the best colour. It has a sweetish taste when
chewed, and is distinguished from red Sanders or sandal wood by giving out its colour
to water, which sandal wood does not. The colouring matter may also be extracted
bv alcohol or ammonia, und with greater facility than by water. The spirituous
tincture, according to Bufav, stains warm marble of a purplish red, whicn, on in-
ereaaing the heat, becomes violet ; and, if the stained marble be covered with wax and

* In the calmlatloD of Iierapath*t aaaljtU, the carbonic acid Is deducted.

t Miaed wlib eand. X And 1*5 basic ferric phoepbate.

656 BREAD-

considerably heated, it changes through all the shades of brown, and at kst beeomcs
fixed of a chocolate colour.

According to Chevreul (Ann. Chim. Ixri 226) the red colouring matter of Bcszil
wood, to which he gives the name Brcunlin^ exists ready formed in the wood, and is
simply dissolved out bv water or other solvents; but according to Prei8Ber(A]m.
Ch. Pharm lii. 369), the red coloujcing matter, Brarilein, consisting of C*^*H)', u
formed by oxidation from a colourless principle, BrasUin, CH'H)*, contained to the
wood, BO that Freisser's brazilein is the same as Chevrenl's bnudlin.

Preisser prepares brazilinby agitating a concentrated alcoholic extract of the wood
with hydrate of lead, decomposing the resulting salt with sulphydric acid, filtering and
evaporating the colourless hquid, which afibrcu small, acicmar, colourlera oTBtais of
brazilin, C'^H'K)', .whose aqueous solution slowly turns yellow on exposoie to the air,
and at the margin brilliant red. This change takes place more quickly on boiling the
liquid, which then, on cooling, deposits bri&iant red needles of brazilein, C^'*0^
Chevreul originally obtained the red crystals by agitating the aqueoos extract of the
wood with oxide of lead, evaporating the filtrate to dryness, and digesting the residae
in alcohol The solution thus obtained yielded the red crystals by spontaneous erapo-
ration. Possibly the colourless brazilin was oxidised to brazilein during the process.
At all events, Preisser's view is in accordance with the fact that Brazil wood beeomeB
darker in colour by exposure to the air.

Brazilin is soluble in alcohol and ether. Hydrochloric acid^ with access of air,
colours it bright red. StUphurio acid dissolves it with yellow colour, which aoon
changes to black. Nitric acid first reddens it, then gives off red fumes, and conveits
it into oxalic acid. Potash and 9oda^ in contact with the air, also tun it red ; aai-
moniOy dark red purple. The aqueous solution forms a yellowish precipitate with
acetate of lead, and reduces ffold and silver from their solutions. — (premie aeid^ or
pulverised acid chromate of potassium, introduced into the aqueous solution, prodoces
brisk effervescence, arising from the escape of formic add, and gradually precipitates
a dark crimson lake, consisting of a compound of hydrate of chromium witn braziieizL
(Preisser.)

Brazilein is soluble in water, alcohol, and ether, forming red solutions, which are
decolorised by sulphydric acid, are coloured purple by alkalis, and form poiple pre-
cipitates with lead and tin salts, and a red precipitate with aluoL

These precipitates, obtained with an aqueous decoction of Brazil wood, are exten-
sively used for dyeing and for staining paper for walls. The solubility of the colouriog
matter of Brazil wood, and its strong uBnity for mordants, give it a vezy eztensire
range of application both in dyeing and in calico-printing. (See MuspraUs Chemutty,
L 673, and Ur^s Dictionary of Arts, Manufactures, and Mines, L 397.)

8BBA]>« Bread consists of the flour of wheat or other cereal grain, kaeaded
with water into a paste or dough, which is rendered porous by the interpene^tion of
carbonic acid gas, either generated within the mass of the dough by fermentation, or
forced into it by mechanical means. The dough having thus acquired the proper
degree of porositv, is exposed to the heat of an oven, whereby the enclosed gas is
further expanded, its escape being prevented bv the simultaneous formation of the
crust. The crumb of the bread thus produced is a soft porous mass, of swollen bat
otherwise unaltered starch, mixed with vegetable fibrin ; in the erost, the starch is
mainly converted into dextrin and empyreumatic products.

It is the rising of the dough, produced by the carbonic acid, which gives to well
made bread its peculiar lightness, and distinguishes it from the dose, heaxy cake, pro-
duced by merely mixing flour with water and baking it. The usual method of gene-
rating the carbonic acid is by fermentation, and the manner in which this process is
conducted has great influence on the quality of the bread ; as, if it be not carried &r
enough, the dough will not rise sufiiciently, and if allowed to go too far, it gives rise
to the foqnation of acid and other objectionable products. To facilitate the nDde^
standing of it, we must give some account of the composition of flour.

The flour of all cereal grains consists of an azotised portion, chiefly vegetable fibrin ;
a non-azotised portion, chiefly starch, with variable quantities of dextrin and sugar;
and inorganic suts, chiefly phosphates.

If moistened wheat flour be kneaded into a stiff paste, and well washed with water,
a milky liquid runs ofi^ and a viscid elastic solid, called gluten, is left behind. The
milky liqmd, if left to stand, deposits a quantity of starch mixed with minute par-
ticles of gluten, and the clear liquid filtered from the deposit, leaves on evaporation, a
quantity of extractive matter, consisting of ve^table albumin, dextrin, glucose,
or grape-sugar, possibly also gum, and other similar proximate prindples, besides
soluble inorganic salts. The gluten, which is essentially the flesh-forming oonstitncnt
of the flour, consists of vegetable fibrin, hdd together by a very tenadous nitrogenous
substance, called glutin or yliadin, wh^ch may be extracted by aloohd ; it also con-

BEEAD. 657

tains small quantities of fat^ and fine particles of bran mechanically mixed. It is the
gliadin whicn giyes to the nitrogenona portion of wheat-flour its pecoliar adhesiveness,
and eaoses the dough prepared with it to rise into a spongy mass when penetrated by
gases. Other cereal erains, oats and rye for example, though rich in yeffetable fibrin,
contain scarcely any ^iadin, and consequently the dough prepared from Uiem possesses
but little tenacity. This is the chief cause of the great superiority of wheat oyer all
other cereals, for the preparation of bread.

When flour in the moist state is exposed to the air, the nitrogenous matter quickly
passes into a peculiar state of decomposition, in which it is capable of acting as a fer-
ment, conyerting the starch into dextrin and glucose, and the glucose into alcohol and
carbonic acid (see Fermentation). Hence a portion of dough which has been left till
it undergoes partial decomposition, and in which state it is called leaven, is capable
of inducing the so-called fanary^ but really alcoholic fermentation, in a much larger
quantity of dough, when well Imeaded with it. "A little leaven leaveneth the whole
lump." This method of bread-making has been practised from the oldest times, and
is still the only one in use for the coarser kinds of bread, such as the Schwarzbrot, or
black bread of Germany ; but for the finer sorts, beer-yeast- is now used as a substitute,
or rather as a partial subBtitute of leaven. The process generally adopted in this
oountiy is as follows : A certain quantity of flour is mixed with yeast, salt^ and tepid
water. This constitutes the "sponge," which is covered up and set aside in a warm
place, to undergo fermentation. In the course of an hour or so, the mass swells up
considerably from the generation of carbonic acid, large bubbles of which rise to the
surface ana burst. With each successive burst, a sudden falling of the' sponge takes
place, followed by a gradual rising, and these alternate actions would, if allowed, con-
tinue for many hours. Various other modes of making an active sponge are employed,
particulaiiy by the use of potatoes. When the sponge, no matter now formed, is in an
efficient condition, the baker mixes up with it fresh portions of flour, salt, and water, the
quantities so added forming the greater part of the dough. The whole is then subjected
to a thorough kneading with the hands, or sometimes with the feet, so that the ferment-
ing dough may permeate and aflect the entire substance^ and thus cause an eouable
liberation of carbonic acid in every particle. The dough is set aside for a few hours,
during which the fermentation proceeds, then kneaded a second time, and weighed out
into loaves, which are allowed to continue fermenting till they have doubled their
original buQL They are then baked in the oven, within which they undergo a further
increase of size, due chiefly to the expansion by heat of the confined gases : for the
heat of the oyen quickly arrests the fermentation.

In Paris, where bread-making has been brought to a high degree of perfection, the
fermentation is produced chiefly by the gluten of the dough, yeast being used merely
to faolitato the action. A lump of dough remaining from the last bateh of bread, and
consisting of 8 lbs. flour and 4 lbs. water, is left to itself for ten hours : in this state
it is called fresh leaven (levain de chef). By kneading this with another quantity
of 8 lbs. flour and 4 lbs. water, the once-revived leaven {levain ds premiere) is
obtained. After another interval of eight hours, 16 lbs. of flour and 8 lbs. water are
added, forming the twice-revived leaven {levain de seconde); and after three hours
more, 100 lbs. flour and 62 lbs. water containing J to 41b. beer-yeast are added, form-
ing the finished leaven {levain de tout point). The 200 lbs. leaven thus obtained
are mixed, after two hours, with 132 lbs. flour and 68 lbs. water, containing J lb. of
yeast in suspension and 2 lbs. common salt dissolved. This quantity of dough serves
for five or six bakings. For the flrst baking, half the dough (200 lbs.) is made
into loaves of the required size and form, which are exposed for a while in shallow
baskets, to a temperature of 25^ C. (77^ F.), and then transferred to the oven. The
bread thus obtained has a sourish taste and dark colour. The remaining half of the
dough is again mixed with 132 lbs. flour, 70 lbs. water, ^Ib. yeast, and the requisite
quantity of salt ; the half of this quantity of dough is then formed into loaves, left to
ferment, and baked. The same operations are repeated three times, one-half of the
dough being each time mixed with 130 lbs. flour, IJlb. yeast, and the proper quantity
of water and salt The last stage yields the flnest and whitest bread.

In the normal process of bread-making, the carbonic acid, whose evolution gives
ligjhtness to the bread, is derived principally, if not wholly, from the fermentation of
the sugar of the flour, induced by the action of metamorphic gluten. But flour, as
already observed, contains other nitrogenised substances than gluten, and other non-
nitrogenised substances than sugar. Now these nitrogenous substances, the albumin,
for example, readily undergo transformation, and then act as ferments, not only upon
sugar and dextrin, but also upon starch, transforming it into dextrin and sugar, and
sometimes also into lactic acid. This is the process which takes place in the germination
of grain, in malting for example (p. 328), by the action of the albumin in the peculiar
stete called diastase. Now when wheat has been too much exposed to damp during
Vol. L U U

6o8 BREAD.

harvesting, or has sprouted from any suhseqaent canae, or when the flour even of wdl-
harrested wheat ia exposed to heat and moistnie, the albumin passes into this peculiar
state, and the flour becomes incapable of yielding good bread, because, dnnng the
ptoceaa of bread-making, the conxersion of starch into dextrin and sugar, which always
occurs to a slight extent, then takes place in an exaggerated deg^«e. Bread made
from such flour, is sticky, saccharine, and soddened, never light and porousu The
conversion of the starch into dextrin and sugar likewise renders the braid dazker in
colour. In fiu:t, the brown colour of wheaten bread made from flour oontaining fine
bran, is due, not to admixture of particles of bran, but in great part at least to a eon-
version of the starch into dextrin and sugar W the action of the altered albuminous
matter in the braiL According to Mige-Mouries, bnn contains a peculiar nitrogenous
body called certalin^ which is specially active in inducing this conversion : it aroyean,
however, to be identical or nearly identical, with ordinazy diastase. Be this as it
may, it is certain that the finest wheat flour obtained from the central portion of the
grain, which contains but little nitrogenous matter, has very little tendency to mndeigo
the change under consideration ; but coarse flour obtained from the exterior of the
grain, is rich in azotised substances, and more ready to undergo the glucosic deteriora-
tion. In white bread of good quality, the starch has undeisone very little alteration.
A small portion of it is rendered soluble in water, but the greater number of the
granules are simply swollen, not burst, and may be washed out of the bread, collected,
and weighed. Vogel gives the following analysis of a wheat^bread loaf: sugar, 3*6
percent; altered starch, I8'0; unaltered starch, 53*5; gluten, with some starch,

20-7 - 95-8.

The injurious action of diastase, &c. on starch in the process of bread-making ma j
be prevented by the addition of certain mineral substances. Alum haa long been
eroployod for this purpose by bakers, and it certainly has the effect of rendering;
available for brcad-makmg many qualities of flour, which must otherwise be wasted.
Dr. 0 d 1 i n g says (Journal of the Society of Arts, April 9, 1858) : " If we mix a solution
of starch with infiision of malt, in the course of a few minutes only, the starch can no
longer be detected, being completely converted into dextrin and sugar, but the addition
of a very small quantity of alum prevents altogether or greatly retards the trans-
formation. The action of diastase on undissolved starch is veiy gradual, but here also
the interference of the alum is easily recognisable. Bread maae with iid(bsion of bran
or infusion of malt, is veir sweet, sodden, brown-coloured, and so sticky aa almost to
bind the jaws together during mastication. But the addition of alum to the dough
causes the loaves to be white, dry, elastic, crumbly, and unobjectionable, both as to
taste and appearance. I have found that flour which is of itself so glucogenic as to
yield bread undistinguisbable firom that made with infusion of malt, could, by the ad-
dition of alum, be made to furnish a white, dry, eatable loaf."

Alum is also said to prevent bread from turning sour and mouldy. The soumoRS
often observed in bread of inferior quality, arises firom the conversion of part of the
starch into lactic acid. Now as alum prevents the transformation of starch, it may be
expected also to interfere with the production of lactic acid.

Considerable discussion has taken place as to the probable effects of the habitual
use of alumed bread on the digestive fimctions, some medical men asserting that alum,
unless taken in much larger quantity than is likely to occur in bread, is quite harmless,
while others attribute to it the most iigurious effects. In this, as in many cases, the
truth probably lies in the middle. Many of the statements which have been put forth
on this, as on other questions relating to the adulteration of food, are doubtless grossly
exaggerated ; nevertheless, it would be unsafe to assert that the use of alum is quite
firee from objection. Dr. Dauglish, in a paper to which we shall have again to refrr,
says : " Its effect on the system is (hat of a topical astringent on the surface of the
ahmentary canal, producing constipation, and aeranging the process of absorption.
But its action in neutralising the efficacy of the digestive solvents, is by fiur the most
important and unquestionable. The very purpose for which it is used by the baker,
is the prevention of those early stages of solution which spoil the colour and lightness
of* the bread whilst it is being prepared, and which it does most effectually : but it
does more than needed : for whilst it prevents solution at a time that is not desirable,
it also continues its effects when taken into the stomach, and the consequence is, that
a large portion of the gluten and other valuable constituents of the flour, are never
properly dissolved, but pass through the alimentary canal without afiR>rding any nourish-
ment whatever."

Another objection made against the use of alum, viz. that it has the power of causing
bread to retain a larger proportion of water than it otherwise would, so that bakers
who use alum defraud their customers by selling water instead of bread, does not
appear to rest on satisfactory evidence. Odling {loc. cit) examined the new crumb
of eighteen alumed and seven non-alumed loaves, and found that the former contained

BREAD.

659

OB the avera^ 43*68 per cent, and the latter, 42*78 per cent, water, the difference being
quit« insignificant as compared with the differences between the individual loayes,
whether tdnmed or not. The detailed resolts, together with the proportions of
nilzDgen and ash in the loaves, are given in the following table, the samples marked
with an asterisk being the non-alomed loaves. Thev are interesting in a general point
of view, independently of the alum question. The loaves were new, that is, obtained
daring the day on which thej were Baked.

Pereentage of Watib, NiTHoamr and Ask, in Bread Alumed and Nan-atumed.

Psrcentaso

of Organic

Hatter.

56-48
66*07
63-74
62*12
63-24
64*29

69-79
66*00 I

66*09
66*82
64*61
63-66
64*41
6607
66-69
64*92
66*66
66*99

.*2a-4

64*67
64*22
66*24
66*68
67-76

1381*61

66*26

PerMntago

of Mineral

Matter or

Aih.

1*49
1*07
1*46
117
1-34

1-21
1*69

1-24
1*24
119
1*33
1*26
1-23
1*36
1*18
1*23
1-43

1*26
1*32
1*33
l'-4»
0*90

32-66

1*30

Percentage

of A»h In arj

Bread.

2-61
1*87
2*62
219
2-46
2-47

Tir

2*^8

■mrrt

2*20
2*17
2*13
2-43
2^28
218
2*39
211
2-12
2*60
2*90

2*38
2*36
2*62
1*64'

67-67

2-30

Percentage

of Nitrogen

in new

Bread.

1-83
1-47
1*89
1-14
1*66
1-04
1-06
116

■■i'81 —
0-93
112
1-14
117
1-23
101
1-24
113
1*23
1*34
1*39

118
1*19
117
1-33

81-63

1-26

Percentage

of Nitrogen

in drr

Bread.

3-21
2-67
3-42
213
3-06
1-88
1-90
1-47

1-66
1-96
2-06
2-16
2-21
1-81
218
2-03
2-14
2-34

1-94
2-14
2*10
2-06
2-27

66-72

2-22

Lime-water has also been recommended to prevent the transformation of starch
during paniftcation into dextrin, sugar, and lactic acid. It was first suggested by
Liebig, and is said to have been used to a considerable extent by the Glasgow bakers.
Odling finds, from laboratory experiments, that lime-water is quite as effective
as alum in preventing the action of diastase upon starch, but seems to have scarcely
any infiuenoe on the fermentation induced by yeast, or, at any rate, a much less action
than alum, which certainly retards the process in a perceptible degree. In this respect
then lime-water possesses an advantage over alum ; it would also doubtless be con-
sidered less objectionable in its direct action on the digestive oreans. Bread made
with it is of agreeable taste, of rather more porous texture than ordinary baker^s bread,
and quite free from sourness.

There are doubtless numv other mineral substances which would act in the same way
as alum or lime-water. Tnus sulphate of copper acts very powerfully in opposing
the action of diastase, and is said to have been used for that purpose in Belmum, an
ounce of the salt being dissolved in about a quart of water, and a wine-glassfiu of this
solution mixed with the water necessary for fifty quartern or four-pound loaves. This
quantity is extremely small ; nevertheless the use of so poisonous a substance as sul-
phate of copper cannot be too strongly condemned : breaa containing copper would be
sure to act injuriously in the long run.

uu 2

660 BREAD.

Mineral substances added to bread may be detected and estimated in the ash by
the ordinary processes of inorganic analysis^ A few detaila may, however, be added
relating to the detection and estimation of alumina. The bread taken tat ezaminatioa
should be crumb, from the middle of the loaf; it should be carefully tzimmedfitim
crust and outside crumb, as those portions may be dirty. It is then to be charred on
a platinum tray ; the charcoal reduced to powaer and incinerated in a muffle (p. 418);
the ash digested in pure strong hydrochloric acid ; the filtered solution eTaporated (o
dryness to render silica insoluble ; the dried residue drenched with strong hydroddorie
acidf then boiled with water, and the liquid filtered. The acid filtrate must nest be
nearly neutralised with carbonate of sodium, pure alcoholic potash added in exeen,
which will precipitate earthy phosphates and retain alumina in solution, and the
liquid boiled and filtered ; aqueous pot-ash must not be used, as it always eontaiiu
alumina. The alkaline filtrate is then to be slightly supersaturated with hydrochltnie
acid and boiled with carbonate of ammonium ; this will precipitate all the alamiaa,
which may then be collected, dried, and tested with nitrate of cobalt befisre the blov-
pipe. (See p. 166.)

If a quantitatiye determination is to be made, it must be remembered that the
alumina precipitate generally contains phosphorie acid. To estimate the amoant of
this acid, the precipitato, after being weighed, is to be dissolved in hydroddoric add,
the solution mixed with tartaric add, excess of ammonia added (wmch will pradnee
no precipitate), and then sulphate of magnesium. The phosphoric add will thereby
be precipitated as ammonio-magnesian phosphate, which is conrerted by ignitioD into
p^ophosphate of magnesium, Mg^P'0^ whence tlie quantity of phosphorie anhydride
(P^O*) may be calculated, and this, deducted from the totid weight of the aloBmia
precipitate, gives the quantity of alumina. Or the predpitated alumina containing
phosphate maj^ be dissolved in nitric acid, a piece of metallic tin added, and the hqnid
boiled. : the tin is thereby oxidised, and remains as an insoluble powder, coosistme
of stannic oxide and phosphate, the whole of the phosphoric add bemg thus sfpanted
from the alumina. The whole is next evaporated to cuyness, the lemdue tnated with
water and filtered, and the alumina predpitated from the filtrate by caibonate of
ammonia.

UiTFERiCBNTBD Bbbao. — Instead of using alum or other mineral substaneea, as
above described, to counteract the injurious secondary actions which take place dnnns
the fermentation of dough, methods nave been proposed, and to a certain extent eairiea
out, for dispensinff with the fermentation altogether, and supplying the eaibonie add
which is to give lightness to the dough, from some extraneous source.

1. Instead of mixing salt (chloride of sodium) witii the fiour and water, hydrochloric
acid and carbonate of soda are added in the proportion required to form chloride of
sodium, the carbonic acid thereby evolved caudi^ the dough to rise just as if it had
been generated by fermentation. Bread thus made is said to be of good qnah'ty,
though it is never so white as ordinary baker's bread. There is, however, a seriooa
objection to its constant use, namely, that it is liable to be contaminated with aneaie;
introduced by the hydrochloric add. That acid indeed, as found in commerce, ahnya
contains arsenic, the complete removal of which can only be effected by a process modi
too costly and troublesome for the purposes of a bake-house ; and though the onantity
of arsenic actually present in the bread may be small, still by daily use it mig^t aecn-
mulate in the system and ultimately produce injurious effects.

2. Preparation of A£bated Breaj>. — Carbonic acid gas produced from chalk, either
by the action of dilute sulphuric acid or by ignition, and stored in an ordinaxy gas-
holder, is pumped therefrom into a cylindrical vessel containing water, whereby the
water becomes charged with the gas. This carbonic acid water is mixed under pres-
sure with the flour, and the resulting dough, which becomes vesicular on the remoTiI
of the pressure, is divided into loaves and baked. This process, which was inrented
and patented by Dr. Dauglish, has been carried out on a large scale in London and
other places.

The following is a description of the apparatus: — A (fy. 112) is the mixer or vpsad
in which the flour, water, and salt are mixed together. It consists of a very strong
iron spheroidal vessel, with an internal capadty of from 17 to 20 cubic feet It has
an opening B at the top, to which an air-tight cover is fitted, and the means of dosing
it to resist considerable pressore. There is also a corresponding opening C at the bottom,
large enough for a man-hole, and also closed by a lid, to which is attached the appa-
ratus for drawing off the dough through suitable mouthpieces in a continuous stream,
which is cut into pieces by a boy, and received into boxes or baskets to be conveyed
to the oven. Through the centre of the mixer, a shaft passes furnished with stofBng
boxes, to prevent the escape of compressed gas, and in this shaft suitable mixing arms
are fixed : by means of the necessary gearing this shaft is made to rotate by steam
power. D is a copper water- vessel, having communication with the mixer from the

BHEAD.

boUoro by dimdi of a Talrs, and from the top bj in<
ths nter-TeoeL This WHUr-TeaHel hiu also commun
pampB, which are fixed ia the

fame fr»me behind the mi.er, ^<ff- H^-

and an worked by a stei.m en-
gine. The commnnication ia b;
means of the pipe E, which ter-
minatce within the wat«r-Te«scI
b; a Toee perforated with miontti

To work the appiiTitiis, thi?

top coTCT B of Che mixer in

opened, and abonl fifiO Ibi. of

llonr are ahoC into it bj

means of a hopper and shoot

connreting with toe floor HboTe ;

wstcr, to the amount of 30 gsl-

looB or >o, is drawn into the

water- vessel fHim a cistern abore,

and the whole is then elosed,

after adding to the flour the d»-

eesaan salt. After removing

the air fram the apparatus bjr a

■nitsfale pnmp, carbonic acid

is pumped by the oondensing

pnmp from a gas-holder, in which

It is stored until it ia condensed

to aboot seven atmospheres. This

condensed gas being dispersed by

the rose at Che bottom of the

water-reesel, passes in minute

streams through the water, and

as the density within increase^

the wmt«r absorbs the gas in pti>

portion, that which is not s&-

Borbed paasing down the inlemsl

pipe from the lop of the water-

Tesael into the mixer, so that

the density within that vessel

is kept in equilibrium wiCh that

in ths wster-venel. When the

right density is sttuoed, the

vaJre at the bottom of the' •

water-vessel is opened, when the

water falls upon the floor, afler

whichthemixingarmaaresettowork, and in aboutsii minutes the dough is thoroughly

formed. It is allowed to subside for a minute, and is then drswn off through the

bottom apparatus, being forced through it by the elastic force of the gas within.

On neaping from the condensed atmosphere in the mixer, the dough immedialely

assDmea the vesicular form and texture, and is ready to be bsJied.

The carbonic acid is obtained by acting on whiting or ground chalk with snlphDrie
•rid ; it comes off perfectly pure, and, being kept over water, ia thoroughly washed.
It t^ea about ZO cubic feet of car})0nlc acid at atmospheric density to prepare dough
from 280 Iba, of flour, about 11 cubic feet being incoi^rated with the dough, the re-
maining 9 cubic feet being wasted in the operation of drswiog the dough off, and in
other ways: 7 lbs. of eulphuri; acid give, in practical working, 21 cubic feet of
carbonic acid from 10 lbs. of carbonate of lime, the aulphuric acid being of density of
1 -SiS. The gas which is left in the apparatus slier the dough is discharged, is re-
turned to the gas-holder for further use.

The adrsntsees of this process are thus stated by Dr. Odling in a paper read before
the Chemical Section of the British Association at Aberdeen in 18M:— Ist. Its
cleanlineaa. Instead of the dough being mixed with the naked amiB Or feet, the
bread, from the wetting of the flonr to the completion of the baking, is not, and
scarcely can be, tooched by any one. Zod: Its rspidity. An hour snd a half servea
for the entire conventon of a sack of flour into baked loaves : whereas, in the ordinary
proeras, four or five hcnurs are occupied in the formstion of the Sponge. &nd n further time
in tho kneading, raising, uid baking of the dough. 3rd. Its preventing the glucogenic

662 BREAN— BREITHAUPTITE.

deterioration of the flour, which takes place in the oidinaiy proceBS (p. 657), and tbenly
obviating the necessity of using alum. 4th. Its certainty and uuformity. Oving to
differences in the character and rapidity of the fermentation, dependent on TariaUoos
of temperature, quality of yeast, &c., the manufacture of fermented bread fireqooitlj
presents certain vagaries and irregularities fix)m which the new process is eDtireljfne.
5th. The character of the bread. Chemical analysis shows that the flour has under-
gone less deterioration in bread made by the new than in that made by the fermentiqg
process. In other words, the percentage of extractiTe matters is smaller. The nev
bread has been tried dieteticaUy at Guy's Hospital, and by many London phyndsna,
and has been highly approyed o£ It is well Imown that, for some years past, the nae
of fermented bread in dyspeptic cases has been objected to by memben of the medical
profession, the debris of the yeast being considered unwholesome, and liable to induce
acidity. 6th. Its economy. The cost of carbonic acid is alle^jed to be less than the
cost of yeast Moreover, in making fermented bread, there is a smaiQ but neoessaiy
waste of the saccharine constituents, which is avoided in the new process. 7th. The
saving of labour and health. It substitutes machine labour for manual laboiir of a
very exhausting kind. The sanitary condition of journeymen bakers was investigated
some time ago by Dr. Guy, and round to be most lamentable, firom their constant
night work, and firom the &tiguing and unwholesome character of their labonr, pa^
ticularly the kneading. In a politico-economical point of view, the process is also
important^ as removing bread-making from a domestic manual work to a mannfartnring
machine work. From the character of the apparatus, the process can only be used
profitably on a large scale, and not in small bakeries.

Of all the advantages just noticed, the most important is the prevention of the de-
terioration of the flour, which is so apt to occur in tbe ordinary process of bread-
making. We have already observed (p. 657) that this deterioration consists in a too
great conversion of the starch into dextrin and sugar, and that it takes place to the
greatest extent when flour is used which contains the external as well as the central
portions of the wheat-grain, because the external portions are rich in nitrogenom
matter, — the central consisting almost wholly of starch, — and a portion of this matter
passing into a metamorphic state (diastase or cerealin) and acting as a ferment,
produces the change just mentioned. Now it is important that this external nitro-
genous portion of the grain should be retained — especially for persons who eat bnt
little meat, and to whom bread is essentially the stAff of life, — both for its direct
nutritive power, and for the part which the metamorphic gluten undoubtedly plajs in
assisting the solution of the starch and unaltered gluten m Hlg process of digestion.
In this country, however, there is an almost univenal preference for white bread, and
consequently the miller contrives so to grind and dress his flour as to get rid as &r as
possible of the nitrogenous portion, and thereby prevent the conversion of the starch
into dextrin and sugar during fermentation, wluch, as already observed, is the chief
cause of the loss of whiteness. Hence it is, perhaps, as Dr. Dauglish suggests, that
wheaten bread has not hitherto entered so extensively into the diet of the poor man
in England as oatmeal in Scotland. The latter is prepared for food by simply boiling
it in water in the form of a porridge, so that all the elements are present^ to tiie
system uninjured by artificial processes, whereas our wheaten bread is generally prepared
in such a manner as to rob it of certain of those constituents which not only possess ia
themselves great nutritive power, but likewise materially facilitate the dig^ition of the
whole. Now the new method of bread-making renders it possible to retain all these
matters, and at the same time to produce a light crumbly loaif, without the use of alnm
or any other mineral ingredient (See a paper by Dr. Dauglish read before the Societj
of Arts, 25 April, 1860 ; also " On Fermented Sread and Aerated Bread," Hedical
Times and Gazette, 12 May, 1860.)

For further details on the making of bread, and for descriptions and figures of
kneading machinery and patent ovens, see the article Bread in Ur^s Dictionarj/ of
Arts, Manufactures, and Mines^ i. 400 ; Muspratft Chemistry^ L 353 ; Payen, JWew
de Chimie Industrielle, 4— id. ii. 126 ; Handtoortfrbuch d. Chan. 4*« Aufl. n. [21 511.
On the composition of wheat-grain, flour, and bread, see Lawes and Gilbert (Chan.
Soc Qu. J. X. 1, 269.)

See IciGA Rbsin.

and MBMKMm See Abbol-jL-Bsha..

IZSXhAJCZTB. A mineral occurring in cavities of yesuvlan lava, in capillaiy
crystals. Chapman (Phil. Mag. [3] xxxvii. 444) regards it as a variety of augite.
The form is that of basaltic augite. Colour brownish or grey with metallic lustre ^ Melts
before the blowpipe to a shining magnetic bead. Not attackea by boiling hydrochloric add.

Native antimonidc of nickel, Ni'Sb (p^ 316).

BREMER GREEN — BRICKS. 663

A green pigment consiBting chiefly of basic carbonate of
cof^ier mixed with alnmina and carbonate of calcium. According to Bley, a fine blue-
green eolonr is obtained by dissolving commercial sulphate of copper in 10 pts. of
water, adding a Uttle nitric acid, leaying the liquid to itself for a week, then filtering,
adding fresh lime-water, precipitating with filtered solution of pearl-ash, and mixing
the washed precipitate with gum-water to gixe it lustre.

See MAONXsmL

See Natboutb.

A somewhat rare mineral, occurring in transparent colourless
prismatic aystals, of the monodinic system, with the lateral faces inclined to the ter-
minal faces, at an angle of 93^ 40'. Specific gravity 2*12 to 2-2 (Brewster); 2'463
(Mallet). Hardness » 5'0 to 6*5. According to the following analyses by Conn ell
(Ed. N. Phil. J. xiy. 35), Thomson (Mineralogy, i. 348), and Mallet (SilL Am. J.
xxviii. 48), it is of the form M«O.Al*0«.6SiO* + 5H*0, the symbol M denoting

[2] ,. . . . ^

strontium, barium, and calcium in the atomic proportion Sr : Ba : Ca » 4 : 2 : 1, and

by regarding the water as basic and substituting tduminicum (a/ss9'2) for aluminosum

(Al » 13-7), the formula may be reduced to M<<z^^>«Si*0«, which is of the form

E«Si«0' or R*SiO*.K«SiO«:

SiO» A1«0« BaK) Si«0 CaH) H*0 Fe*0«

53-67 17-49 6'75 832 1-36 12*58 0*29 » 100*45 (ConneU)

53-04 16*54 602 9*01 0*80 14*73 — - 1001 7 (Thomson)

62*42 15*25 6*80 8*99 119 13*22 trace « 97*87 (Mallet)

Before the blowpipe, it parts with its water and becomes opaque, then froths, and swells
up, but melts with difoculty. Leayes a silica skeleton when fused with phosphorus-
salt. Dissolyes in acids, with separation of silica. It occurs at Strontian in Argyleshire,
on the Giant's Causeway, in the lead mines at St. Turpet near Freiburg, in the
Breiagau, in the department of Isire in France, and in the Pyrenees.

JBMMWVTOKMM, A liquid hydrocarbon found in minute caxities in crystals of
topaz, chrysoberyl, quarts from Quebec, and amethyst from Siberia, in which it was
detected by Sir D. Brewster. It is transparent and colourless, and is nearly thir^-two
times as expansible by heat as water, increasing one-fourth of its yolume by an incre-
ment of 30^, at 50° F. On exposure to the air, it undergoes quick motions and
changes, and finally eyaporates, leaying a residue of minute sondparticles, which, from
the moisture of the hand alone, suddenly become fluid again. The residue yolatiUses
by heat, and dissolyes in adds without efflorescence. (Dana, ii. 471.)

BSZCS8. Common bricks are made with day mixed with sand or ashes, and
baked or burnt at yarious temperatures. In some southern countries, bricks are merely
dried in the sun, but they then remain T&rj friable, and are fit only for light con-
structions. Keaiiy all semmentaiy or alluyial formations contain clays which may be
used for making mricks. Some days do not require any addition of sand, but with
plastic clays an admixture of sand is necessary. In this country, coal-ashes are mixed
with the day, partly to giye it the right consist'Cnce, partly to facilitate the burning.
The clay is dug up and turned oyer in the winter, and oeing thus exposed to wet
and frost, it breaks up and mixes better with the coal-ashes which are afterwards
added. For stiff days, 50 chaldrons of ashes are added to 240 cubic yards of day ;
for days containing much sand, 40 chaldrons of ashes to 220 cubic yards of day, and
these quantities make 100,000 bricks. The day and ashes are mixed with water and
thoroughly incorporated, first by raking and afterwards in the pug-milly which is an
iron-hooped barrel, in the centre of which is a yerticad shaft, worked by a horse, and
bearing six kniyes, all of which, except the top one, are fbmished with teeth. At the
bottom of the barrel, is a small hole, through which the masticated clay is forced by
ihe grinding of the teeth. The clay is next fashioned into bricks in rectangulaf
wooden moulds, preyionsly sanded. The bricks are then dried in the air, and after-
wards made up into heaps called clamps^ hayins flues or spaces left in them, which are
filled with dry wood, on which is put a coyenng of breeze, a coarse kind of coal-ash
left from the sifting. The clamp -^en full is surrounded with old bricks, and on the
top of all a thick layer of breeze is laid. The external bricks at the sides are coated
with a thin plastering of day, to exdude the air^ and in wet weather protected by
hurdles hayme rushes woyen into them. The fire is lighted at the mouths of the
fines, which, if it bums well, are then stopped up. In farourable weather, the bricks
are burnt in about twenty-fiye or thirty days. In this mode of burning, the coal-ashes
incorporated in the substance of the bricks contribute greatly towards the effect.
Sometimes, however, bricks are burned in kilns, and then they haye no ashes mixed
with them, the firing being wholly extemcd.

Fire^Mcks are bncks made of refractory clay, that is of clay which will stand a

vv i

661 BRICKS — BROMACETIC ACID.

Teiy strong heat without fusing. Such days most be free from lime and oxide of
iron. The clay of Stourbridge in Worcestershire, and those of Burgundy are cele-
brated for their fire-resisting qualities, and are therefore used for making bricks fw
lining furnaces. The clay is mixed with sand or with the fragments of old fin-
briclu ground to powder. (See Ur^s JHctumary of ArtSj Manufaeturea, and JAiea,
i. 441.)

BKIOX8 (r&OATnrO). Bricks that swim on water were manufactured hy Am
ancients ; and Fabbroni discovered some years since, a substance, at Gastel del Ham,
near Santa Fiora, between Tuscany and the States of the Church, from which similar
bricks might be made. It constitut.es a brown earthy bed, mixed with the reniaiss of
plants. Hauy calls it talc pulvirulent sUicifht^ and Brochant considers it as a Tsriety
of meerschaum. The Gi^rmans name it Bergmehl (mountain meal), and the Italians
laite di luna (moon milk). According to maproth's analysis, it consists of 79 silica,
5 alumina, 3 oxide of iron, 12 water, and 1 loss, in 100 pts. It agrees nearly in oom-
position with Kieselffuhr. U.

BKZ&IAAJTT. Diamond cut in such a way as to reflect light moat riridlj, is
called a brilliant See Diajcond.

KTOMHa See Sulphub.

iZOJkm A plant belonging to the order GutHfenB. The
pericarp of the fruit is used in Qoa as a spice, and the blood-red acid joioe as a
lemonade. The seeds are coutcz, red-brown, tasteless, of the sice of ordinaiy beans,
and contain 1*72 per cent nitrogen, or after removal of the fat, 2*68 per cent In the
dry state, they do not vield any fat by pressure, requiring to be previously softened hj
vapour of water ; by the use of solvents, 30 per cent of fat may be extracted. The
crude fat is nearly colourless, melts at 40^ C, dissolves sparingly in hot alcohol, and
easily saponifies, yielding glycerin, together with oleic and stearic acids, the latter
amounting to 50 per cent From the crude fat, pure stearic is easily obtained hjeep'
tallisation and pressing out the mother-liquor. The red-brown cake left after ex-
hausting the fat with ether, contains a fine red colouring matter, soluble in water and
alcohol, insoluble in ether and in adds. (J. Bonis and D'Oliveira Pimentel,
Compt rend. xliv. 1366.)

li. An alloy of tin and antimony. (See Tin.)

^XTBTV& Syn. with Glaubbbitb. — BKXTZBK C^UIC SeeDsxTBor.

OBSa Native sulphide of silver. See Silvbb.

A calcareous stone or marble, composed of fragments of km
colours, white, yellow groy, and red.

BXOOCO&Zi See Bbassica.

SSOCBAVTZra. A basic sulphate of copper, Cu'SO^GOnHO. found natire.
associated with malachite and red copper ore, at Ekatherinenburg in Siberia, and at
Rezbanya in Hungary. Small right rhombic prisms of 117^. £merald-green, trans-
parent with glassy lustre ; harder than calcspar. Specific gravity 3*80 — 3*87. Melts
before the blowpipe, and forms a bead of reduced copper or charcoaL
^OBBBO TAWTAXiZTBa See Tamtalitb.

A sul^hantimonite of lead and silver, 2PbAgS.Sb^, from
Mexico. It occurs in masses without cleavage. Lustro metallic Streak greyish-
black. It is rapidly attacked by strong nitric acid. An analysis by D amour (Ann.
Min. [4] xvL 227) gave 1038 per cent S, 2996 Sb, 26-03 Ag, 2474 Pb, 0-64 Co, and
004 Zn.

iOGMIAMVJM or MMOOMTAM'Mfl*M!Mm Syn. with Glaubbbrb.

», C«H«BrO«.— <W. H. Perkin and B. F. Duppa, Chen,
Soc. Qu. J. XL 22.)
Formation^ — ^By the action of bromine on acetic acid : —

C*H<0« + Br« « C«H»BrO« + HBr.

A small quantity of dibromacetic acid is formed at the same time.

Preparation. — A mixture of glacial acetic acid and bromine in eqttal numhen of
atoms (an excess of acetic acid being used to absorb the hydrobromicadd and therebr
diminish the pressure) is introduced into a strong sealed tube, and heated in an oil-
bath to 160^ C, and the bath is then left to cool gradually. When the temperat^ire has
fallen to about 146^, the mixture suddenly becomes nearly colourless, or light amber-
brown, and at the same time, the tubes are apt to burst, though the temperature of
the bath may have risen as high as 166^. The tube when quite cold is opened,
torrents of hydrobromic acid gas then escaping ; the contents are transferred to a
retort provided with proper appardtus for condensing the hydrobromic acid, and

BROMACETIC ACJD. 660

hated to 200^; and the retort is left to cool. The whole contents then solidify
after a irhile into a beautifullj crjstalline mass, consisting of bromacetic and dibro-
macetio adds, mixed with a little hydrobromic acid, to remove which the mixture
18 heated to 180^, and carbonic acid gas passed through it till the presence of hydro-
bromic acid is no longer indicated by nitrate of silver. Carbonate of lead is then
added in excess, together with a Yolume of water about ten times as great as that of
the add; and the whole is heated to 100^, and allowed to stand for some hours.
Bromacetate of lead then crystallises out, while dibromacetate remains in solution.
The ciystals may be freed fiom the last portions of this salt by washing with a little
eold water. Lastly, the ciystals of bromacetate of lead are suspended in water and
decomposed by smphnretted hydrogen, and the filtered liquid is evaporated till it
crystallises.

Bromacetic add forms riiombohedial crystals which are Tery deliquescent It melts
below 100^ C, and boils at 208^ ; attacks the skin powerfully, raising a blister like a
bom ; when the add is dilute, this effect takes place after eight or ten hours only. It
ia rezy soluble in water.

The add strongly heated in a sealed tube, is resolved into dibromacetic add,
carbonic oxide, and apparently marsh-gas, together with water and hydrobromic add,
probably as represented by the equation :

8C»H«BrO« - (?H^Bi«0* + SCO + CH* + HBr + H«0.

On distillinp it with acetate of potassium, acetic add is evolved. — ^Heated with
metallic zinc, it yields acetate and Q^mide of zinc. — ^Heated with ammonia, it forms
bromide of ammonium and glycocine :

C«H»BrO« + 2NH» - NH«Br + C^*NO«.

The arid is monobasic, the formula of its salts being tPil*BrO*.M. Most of them
are ciystallisable and many of them decompose rapidly.

Bromacetate of Ammonium. — Nearly uncrystaUisable ; very soluble in water; de-
composes when heated, yielding bromide of ammonium.

Bromacetate of Barium crystallises with difficulty in small stars containing water
of crystallisation ; it is tolerably soluble in alcohol.

Bromacetate of Calcium is a very difficultly crvstallisable salt, very soluble in water.

Bromacetate of Copper is a green crystalline salt, very soluble in water. A
solution of it appears to decompose when boiled, as the colour becomes paler. The
solution, after standing for some days, deposits needle-shaped crystals and small mala-
chite-green tufts of great beauty, which appear to contain a large quantity of water of
crystidlisation*

Bromacetate of Lead. — Obtained, dther by neutralising bromacetic acid with oxide
of lead and recrystallising the product from water ; or by adding a solution of brom-
acetic add to a solution of acetate of lead, washing liie resulting crystalline precipitate
with cold water, and recrystallising frt>m water. Crystallises in needles, sparingly
■ohible in cold, but moderately soluble in hot water.

Bromacetate of Potassium,— Ohtamed. by neutralising a solution of carbonate or
hydrate of potassium with bromacetic acicC and evaporating the solution in a waters
bath. It is a crystalline salt^very soluble in water and alcohoL

Bromacetate of Silver, C^'BrAgO*. — Obtained by treating bromacetic acid
with carbonate of sUver, or by adding a solution of bromacetic acid to a solution of
nitrate of silver. In the latter case, it is thrown down as a beautiful crystalline pre-
cipitate, which may be washed with cold water, and dried over sulphuric add in vacuo.
Contains 43*62 per cent, silver (by calculation, 43*9). It is very unstable. The dry
■alt heated to about 90^ C, decomposes with a sort of an explosion. It is rapidly acted
upon by light when moist. Boiled with water, it yields bromide of silver and glycoUic
add:

CBPBrAgO* + H«0 « AgBr + C«H*0».

Bromacetate of Sodium is very soluble in water, but insoluble, or nearly so, in
alcohol.

BBOMAcmc 'BrnsXBa.—BromacetaU of Methyl, C»H»BrO*-C«H«BrO«.CH». is ob-
tained by heating amixture of methylic alcohol and bromacetic add in a sealed tube
fax an hour, to a temperature of 100^ C, washing the product with water, d^ng over
chloride of calcium, and rectifying. It is a transparent, colourless, mobile liquid, having
an aromatic odour highly irritating to the nose and eyes. It is heavier than water ;
boils at about 144® C», decomposing gradually every time it is distilled. Ammonia acts
on it very readily.

Bromacetate of Ethyl C^H'BrO* » C*H*BrO'.C*H* — Obtained in a nmilar
manner to thn preceding It is a dear colourless liquid, heavier than water, and

666 BROMACETIC ACID — BROMAL.

highly irritatinff to the eyes and nose. It boils at 169^ C. Decomposes paitiaDy tnrj
time it is cUstiUed, with eTolution of hjdrobromic acid. It is rapidly acted on by
anu&oiiia.

BromacetaU of AnwL C'H»«B!0«« C«H«BrO».C»H".— Obtaiiied by headai suylie
alcohol with excess of bromaoetic acid, washing the product with water, and di^
over chloride of calcium. It is an oily liquid which has a pleasant odour wfaan eoM,
but if heated, acts upon the eyes and nose like the preceding. It boils at 207^ C^ and
docomposes partially eyery time it is distilled. Ammonia acts but slowly upon it in
the cold.

The bzomacetates of methyl, ethyl, and amyl, boil at temperatures about 82^ to WPC,
higher than the acetates. Thus —

BolUn^'Polnt. Boning-pohit. DMT.

Bromacetate of Methyl . 144^0. Acetate of Methyl . 68° C. W>
Ethyl. . 1690 ^^ Bthyl . 74« 86«

Amyl . . 207** „ Amyl . 12fi<> 82«

A similar difference exists between the boiling points of bromacetic add (208^), and
acetic acid (120<').

Blbronweetlo Atfld. C^'BrK)*. (PerkinandDuppa, GhenLSoaQn. J.zilL)
— Formed, together with monobromacebc acid, when a mixture of bromine and aortic
acid is expos^ to light (p. 663). To obtain it in quantity, the monobrominatod add
is exposed to the action of bromine-vapour in strong sunshine. The podnct may be
freed from hydrobromic acid by passing a stream of diy carbonic acia gaa thmngib it
atl20OC. ♦

It is a colourless, inodorous liquid, of specific gravity 2*26 ; it was once, during wj
cold weather, obtained in fine needle-shaped crystals. When placed on the £in, it
produces paixiful blisters like bums. It boils between 226° and 230° C, bat cannot be
distilled without decom^ition. It dissolves readily in water, producing cold; aim
in alcohol and ether. Zinc decomposes it, with evolution of hydrogen.

JHbromacetate of Ammonium. CH*Bi^*.NH* +^^- — Obtained try neutralising the
acid with dilute ammonia and leaving the solution to evaporate, either in the air
or over sulphuric add in vacuo. Forms splendid crystals, iniit^ give off their water
at 100°, becoming white and opaque. Heated to 100° C. with excess of ammonia, it is
decomposed, giving off volatile products, which have not yet been examined. It dis-
solves readily in water, alcohol, and ether.

Dibromacetate of Potassium is a beautiftilly crystalline salt, shooting out into
long and very brilliant crystals, containing water of crystallisation ; very aolable in
alcohol and water, but not deliquescent.

JhbromacctcUe of Lead is a very soluble and uncrystaUisable substance, drying op
to a tough gum-like mass. When added to water in excess,' it fiises and mns aooat
like a heavy oil ; it is formed by adding the acetate or carbonate of lead to dibrom-
acetic acid.

Mercurous Dibromacetate is precipitated on adding a solution of mercuroos nitrate
to dibromacetic acid ; it much resembles dibromacetate of silver, and like it nndergpes
decomposition when boiled.

Dibromacetate of Silver is formed by adding the carbonate or nitrate of silrer
to dibromacetic acid; it crystallises in small needles, often grouped in stars ▼hen
the acid is dilute. It is easily decomposed at 100° C. yielding bromide of ailyer and
bromoglycollic acid :

C«HBr*0-Ag.O + H*0 - 0*HBrO.H*.0« + AgBr.

Dibromaceute Bromoglycollic

offilver. •cid.

Dibromacetic acid heated with ethylio and amylie alcohols^ yields the corrraponding
others. The ethyl-compound is de<»>mposed by ammonia, yielding alcohol and
dibromacetamide:

C«HBr*.C«H».0» + NH« « (?H».H.O + N.H«.C«HBiO.

S&OX AOMTJJi 8. See Acbtins.

BBOBKAA. Hydride of TribromaeelyU Omde de Bromitkile. G*HBrK)-iCVr^.H:
(Lowig, Ann. Ch. Fharm. iii. 228.) — A compound analogous to chloral, and produced
in like manner, by the action of bromine on alcohol. 8 or 4 pta. by weight of bronine
are gradually added to 1 pt of absolute alcohol, cooled by ice ; the mixture is left to
itself for ten or twelve days, and then distilled ; and after three-fourths (consistii^ of
hydrobromic acid, bromide of ethy], and other products) have passed over, the residae
is mixed with water, and exposed to the air for a day or more in a shallow bann. It
then deposits lar^e crystals of hydrate of bromal, which yield the anhydrous oomponnd
by distillation with sulphuric acid. Or they may be gently heated with six times their

BROM ALOIN — BROMH YDRINS. 667

weight of sirone salphuric acid, and the anhydrous biomal, which then sinks to the
bottom aa a colourless oil, may be separated by decantation and distilled, first over
slaked and then oyer ^uick lime,

Bromal is said to be also produced by the action of bromine on a mixture of alcohol
and nitric acid. (Aim 6.)

Bromal is a transparent colourless oil, of specific gravity 3 '34. It is somewhat greasy
to the touch, and makes grease-spots upon paper, which however soon disappear. Its
boiling point is above 100° C. and it may be distilled without decomposition. It has a
peculiar pungent odour, and excites a copious flow of tears. Its taste is extremely
sharp and burning, and vezy persistent.

Bromal is decomposed by aqueous alkalis in the same manner as chloral, yielding
faromoform, CHBr", and a formate of the alkali-metal, lame and baryta heated in its
vapour become incandescent, and decompose it, yielding carbonic oxide, water, and
a bromide of the metal mixed with charcoaL Bed-hot iron acts in a similar manner.
It is not decomposed by nitric acid, sulphuric acid, or chlorine.

Hydrate of Bromai. (?HBr«0.2H«0.— Bromal dissolves in a small quantity of
water, and the solution, when left to evaporate, yields the hydrate in laige crystals,
having the form of sul]phat<e of copper. They melt at the heat of the hand, dissolve
readily in water, and vield anhydrous bromal when treated with sulphurie acid. The
hydrate is also formed when bromal is exposed to moist air.

Bromal dissolves sulphur and phosphorus, and mixes readily with bromine, also with
alcohol and ether.

> See Alozk (p. 148).

L See NrraoaHN, Bboiodb of.

Syn. of PBKBBOXOQUiNoinL See Quinonb.

CO AOZB. BBOMULMZXiZO ACI1>. BS01tCAVZ3bA«
^KXDMm Syn- with Dibrokoqvikonamio Acid, Dqbomoquinonio Acn>, and Diuno-
xoauiKoirAjaDB. (See Qtjikonic Acid.)

See Tbibbomofhbntlaxinb, under PKBNTLAXUfx.

CO AOZD. See Amsio Acid. — BBOBCAJTZSOK. See AmsoL.

BSOHASaTSZTB. Native bromide of silver. (See Selvbb.)

8XOIKXZW. C**H*Br* ? — ^A crystalline product^ obtained in small quantity by
the action of bromine on crude benzene. (Laurent)

BROasaTBB&ZBBfBBOannrBB&Zir.BSOIMnTHXBOIBa. SeeViim^
Bbomidb of.

BSO1KBTBZ0VB88Z&. A product of the action of bromine on thionessal {q, «.)
It forms colourless tables, i^parently consisting of C"H"Br*S. (Laurent)

See Bbomidb of Htdboobn.

(Berthelot and De Luca, Ann. Ch. Phys. [3] xlviii. 304 ;
lii 433.)— These compounds are j)roduced by the action of tribromide or pentabromide
of phosphorus on glycerin. Their composition is such as might result from the com-
bination of glycerin and hydrobromic acid, with elimination of water, and may be
represented empirically by the general formula

m C»HK)» + n HBr - jp H*0.

Their names and formula aro as follows :

Monobromhydrin . . C^'BrO* « 0»H»0« + HBr - HH)

Epibromhydrin . . 0^*BrO « C«HH)» + HBr - 2H«0

Dibromhydrin . . Cra«Br*0 « C«H«0« + 2HBr - 2HK)

Tribromhydrin . . C«H»Br» - C«H«0« + 3HBr - 3H«0

Hemibromhydrin . . C«H»BrO» - 2C»HH)« + HBr - 4H«0

H«aglyceric Bromhy- c«H"BrO^« 6C»H^» + HBr - UH«0
arm . . , .

Mono-, di-, and tribromhydrin, may also be regarded as glycerin, C*H*(HO)*, in
which 1 or mora at of peroxide of hydrogen has been replaced by bromine.

Besides th^e compounds, there are formed at the same time others of similar nature,
which have not been examined; likewise acrolein, and dibromallylphosphine, CH'BrT ->
P.H«.(C»H<Br)«.

The bromhydrins heated with aqueous potash to 100^ C, in closed vessels, all yield
bromide of potassium and glycerin.

Preparation of the Bromhydrins. — 500 ^rms. of slycerin are added bv small por-
tions to between 500 and 600 grms. of liquid bromide of phosphorus, the liquid being
cooled after each addition, and the mixture, after standing lor twenty-four hours, is
distilled into a well-cooled receiver communicating with a vessel containing potash-ley.

66S BROMHYDRINS.

to absorb the acrolem yapotir. As an additional precaution against the injurious efieda
of this Taponr, the distillation and all the subs^uent operations should be performed
either in tne open air, or under a chimnej with a good draught

The distillate, consisting of an upper watery layer and a lower liqnid insoluble ia
water, may be freed from part of the acrolein by heating it in the water-bath. It is
then mixed with potash in sufficient quantity to supersatorate the add and des^
the acrolein, and the watery layer is separated from the lower liquid.

The watery liquid is then treated with ether, whereby an ethereal solution is ob-
tained, which, when quickly evaporated, leaves a residue chiefly consisting of the most
volatile products of the reaction, together with epibramhydrin. The lower liquid,
which is insoluble in water and requires to be treated for several hours with rtidu of
potash, consists chiefly of epibromhydrin and dibromkydrin. The residue which re-
mains in the retort after the distiUation, is suspended in water, supersatorated indi
carbonate of potassium, and shaken u^ with etner, and the filtered ethersl extrads
are evaporated : they then leave a mixture of dibromhydriny monobrimkydrv^ and
fleveral other substances.

To sejArate the individual substances contained in these several mixtnree, the mix-
tures are subjected to repeated fractional distiUation, and the fwrtion which does not
volatilise at 240° C. unaer the ordinaiy atmoe^heric pressure, is fractionally distiLed
under diminished pressure (about 10mm. of mercuxy). The distillate thus obtained
between \2(P and 160° consists chiefly of dibromhydrin ; between 160° and 200^, the
compound C*H*Br'P passes over together with monobromhydrin, and between 200^
and 300°, syrupy liquids which cannot be further separated, but appear to be brom-
hydrins. In the retort there remains a thick syrup, together with a black aystaUiae
compound which is hexaglyceric bramhydrin,

monobromhydrin, C»H*BrO««(C»H»r.(HO)».Br.--This compound, which pssw
over at 180° G. m the distillation under diminished pressure, is a neutral ofly Lqnid,
soluble in ether, and having a sharp aromatic taste.

Dibromhydrin, C*H«BrK) « {C»H»)'".HO.Br*.— This, which is the chief product
of the action, is a neutral liquid, of spedflc gravity 2*11 at 18° C. boiling at 219°,
having an ethereal odour, and soluble in ether. Heated with pentabiomide of jrfios-
phorus, it yields tribromhvdrin. Heated to 140° with metallic tin, it is decomposed,
yielding bromide of tin ana a tin-compound insoluble in water but soluble in ether.

When gaseous ammonia is passed into pure dibromhydrin, the liquid becomes
hot, and yields bromide of ammonium, together with an amorphous substance,
CH*^rNO', insoluble in water, ether, alcohol, and acetic acid :

2C»H«Br*0 + 4NH» = 3NH*Br + C«H»«BrNO«;

but if the ammonia gas is passed into a solution of dibiombydrin in absolute aleohol,
the products fonned are bromide of ammonium and hydrobromate of ^ycertmm:

C>H^r»0 + (KH*)«0 « NHfBr + C»H»NO» HBr.

Trihromhydrin. CH'Br*. — Obtained by distilling dibtomhydrin or ejnbrom-
hydrin with pentabromide of phosphorus, treating the product wiUi water, distilling
and collecting apart that which passes over between 17^ and 180° C. It is a heavy
liquid, which fiunes slightly in tlie air, is gradually decomposed by water, and when
treated with moist oxide of silver, yields bromide of silver and glycerin. It rs
isomeric with Wurta's tribromuU of aUyl (called by Berthelot and De Laea, ixtri-
bromhydrin\ and with dibromide of bromotritylene, C'H'Br.Br'.

Epibromhydrin or Oxy bromide of Glyceryl, C«H*BK).— This compoand
is produced in considerable quantity by the action of the bromides of phosphonis oa
glycerin. It may be isolated by repeated fractional distiUation, the portions which boil
at or near 138° C. being each time coUected apart It is a mobUe neutral liqoid,
soluble in ether, with an ethereal odour and pungent taste. Spedflc gravity 1*615 at
14° C. BoUs at 138°. Vapour-density, by experiment, 6;78. (This is considenbly
above the calculated value, 4*80, i^obabiy because the density was taken at a t^pera-
ture too near the boUing point, viz. at 178°, the compound decomposing rapidly at
higher temperatures.)

This compound may be considered as deriving from tribromhydrin, by the snbstitn*
tion of O for Br*. It is isomeric with bromide of propionyl, C*HK).Br. Its fonnnl*
is also that of monobromhydrin minus HK), or of oibionlhydfin nanus HBr.

Epibromhybrin, heated with aqueous potash to 100° for 112 hours, saponifies, yidding
bromide of potassium, glycerin, and a trace of matter soluble in ether. Moist oxide
of sUver decomposes it rapidly at 100°, forming bromide of silver and glycrrin. Dia-
tiUed with pentabromide of phosphorus, it is partly converted into tribromhydiiB, ac-
cording to tne equation :

C«H»BrO + PBr^r* « PBi*0 + C»S»Bf«,

BROMIC ACID. 669

while the rest nndeigoes more complete decomposition, yielding a black sabstanee and a
gaseoiifl mixture, oontainine, in 100 rolumes, 5*5 carbonic anhydride, 6*5 tritylene, 11*0
hydrogen, and 78*0 carbomc ozide.

Hexaglyeerie Bromhydrin. C"H"BrO'. — This compound remains in the
retort in the form of a black crystalline mass, impregnated with a syrupy liquid. It is
purified by washing with cold ether ; boiling ether dissolves it slightly.

Hemihromhydrin, CH'BrO'. — This eompoimd passes orer in the fractional
distillation between epibromhydrin and dibromhydrin, viz. at 200^ C. It is a neutral
liquid, soluble in ether, and saponifiable by potash, yielding bromide of potassium, a suV
fltance analogous to or identical with glycerin, and a trace of matter soluble in ether.
The analyses of the compound are said to agree nearly with the above formula (no
analyses are given in Berthelot and De Luca's memoir), according to which it may be
regarded as derived from epibromhydrin, in the same manner aa the latter from
dibromhydrin, viz. by abstraction of half the hydrobromic acid :

0»H-Br*O - HBr - C«H»BrO :
and

2C«H*BrO - HBr - C«H»BrO«.

It 18 analogous in composition to iodhydrin.

►mo ACZB. HBrO" or H^O.Br'O*.— This add is produced: I. By the
action of bromine on alkalis or alkaline earths :

6Br •«- 3E<0 » KBrO* + 5EBr.

The bromate is separated from the bromide by its inferior solubility. A similar re-
action takes place with triozide of gold, the products being bromate and bromide of
gold:

18Br + 3Au«0» - ^^'^^l'|o« + 5AuBr«.

2. In the decomposition of pentachloride of bromine by water or by alkaUs :

Bra» + 3H«0 « HBrO* + 6Ha

To obtain the free acid (bromate of hydrogen) the barium-salt is decomposed with
an exactly equivalent quantity of dilute sulphuric acid, and the filtrate concentrated
hj evaporation at a gentle heat. It cannot, however, be reduced to a syrupy con-
sistence without decomposition. The solution is colourless, acid to the taste, reddens
litmus, and then bleaches it. It is decomposed at 100^ 0., giving off bromine and
oxyeen. All reducing agents decompose it with facility. With sulphvTOttt acid the
prodocts are bromine and sulphuric acid ; with mdph^drie add, water, bromine, and
sulphur; with Aydriodic acid^ water and bromide of iodine; with hydrochloric add,
water and chloride of bromine; with hydrobromic acid, water and bromine, e,y. i

HBrO» + 6HC1 » 3H«0 + BrCl».

Alcohol and ether decompose bromic acid, with formation of acetic acid and great rise
of temperature.

Bromic acid is monobasic, the formula of the Bromatss being MBrO' or M*O.Br*0\
Host of these salts are soluble in water, though lees so than the bromides. They may
be prepared by the action of bromic acid on the oxides or carbonates of the metals, or
by precipitating bromate of barium with the corresponding sulphates ; the bromates
of tne alkali-metalB also by treating the solutions of the alkalis with bromine-water or
pentachloride of bromine, and crystallising out the sparingly soluble bromate from the
bromide or chloride formed at the same time :

6KH0 + Bi« - KBrO" + 3H«0 + 6KBr
6KH0 + Bra» - KBrO» + 3H«0 + 6KCI

Bromates are for the most part crystallisable, but many of them decompose when their
solutions are heated ; hence it is generally best to evaporate the solutions in vacuo or
over oil of vitriol. The bromates of mercurosum, silver, and lead are insoluble.

Bromates heated to redness either give off their oxygen and leave bromides (K, Na,
Hg; Ag), or they give off bromine and part of their oxygen, and leave o^es, e,y. :

2ZnBrO» - Br» + 0» + Zn«0.

Mixed with charcoal, sulphur, or other combustible substances, fhey explode by heat
or by percussion. Solid bromates heated with sulphuric acid, give off bromine and
oxvgen. A solution of a bromate is coloured red, even by dilute sulphuric acid. By
sulphurous acid and other reducing agents, th^ aro decomposed in the same manner
as the acid. A solution of a bromate, not too dilute, gives with lead-^alts^ a white pre*

670 BROMIC ACID.

cipitata ; with mercurous ialts, a yellowish wMte precipitate, insolnble in eold nitne
acid ; and with sHver-aaltSt a white precipitate almost insoluble in water, spariiiglT
soluble in nitric acid, easily in ammonia. This precipitate is distingiiished from
ehloride of ailyer by giving off red vapours of bromine when heated with solplrazie
acid. The reactions with silver-salts and with solphaiic add distangnish bKnutn
from chlorates (q*v,)

Bromatb of Alxiioniuic. — Obtained as a dear, viscid, deliqnesoent mass, bj dinolr-
ing hydrate of aluminium in bromic add, or by predpitating bromate of potasnom
with silicofluoride of aluminium, and evaporating the filtrate over sulphuric add.

Bbokatb or AxMOMiDiL NH^BrO*. — White needles or crystalline grsDuka, appa-
rently belonging to the regular system. It cannot be preserved in the solid state, aa
it decomposes after a while, with violent detonation, even at ordinazy tempentnrec,
jrielding nitrogen, bromine, oxygen, and water. Hydrochloric add deoomposei it,
forming, however, but a small quantity of chloride of ammonium.

Bbomatb of Basiuic. 2BaBrO' 4- a^.— When bromine or chloride of bromiiM ii
added to baryta-water till the colour begins to be permanent^ bromate of barium oyaEtal-
lises out, while bromide or chloride remains in solution. But a better mode of prepan-
tion is to decompose 100 pts. bromate of potassium dissolved in boiling water, witli
74 pts. crystallised chloriae or 78 pts. anhydrous acetate of barium, and leave the
liquid to cool slowly ; the bromate of barium then separates out, while chloride or
acetate of potassium remains in solution. Acetate of barium is preferable to the
chloride for this preparation, on accoiint of the greater solubility of the acetate of
potassium.

Bromate of barium forms a ciystalline powder or thin prisms of the mooodinie
system, with the faces ooP . ooP oo . ( ooP oo) . Poo . oP . + P oo. — oo P. Indioatioa of
faces, ooP : ooP - 82<» 10' ; (Poo) : (Poo) - 79° 6'; oP : ooPoo - 930 2'; odPob:
Poo = 138°. The salt is isodimorphous with chlorate of barium (Rammelaberg,
Pogg. Ann. zc. 16). It dissolves in 130 pts. of cold and 24 pts. boiling water. It
does not give off its water of crystallisation till heated above 200^ C. When thrown
on red-hot coals, it detonates with a green light. When heated alone, it is resolTed,
with evolution of light and heat, into bromide of barium and oxygen gas, iritboiit
forming a perbromate. Hydrochloric or moderatdy dilute sulphuric add decomposes
it with separation of chloride of bromine or free bromine ; very dilute snlphixric add
separates undecomposed bromic add.

BB01CA.TB OF Bismuth. — When bromic add is poured upon hydrate of bismntli, a
basic insoluble salt is formed, together with a small quanti^ of dissolved salt Thfl
basic salt, 3BiK)'.2Br'0* + 6 aq., is a white amorphous powder.

Bboicatb of CiLDMixTic. iCdBrO* •«- aq. — Rhombic prisms of 127° and 53^ vith
Ibur-sided summits and truncation of the acute lateraT edges by two narrsw fiun.
Soluble in 0*8 pts. cold water. Decomposed by heat^ leaving oxide of cadmium mixed
with bromide.

Ammonio-bromide of Cadmium, 3NH'.CdBrO*, is deposited from an ammomacal
fK>lution of bromide of cadmium evaporated over quick lime, as a white crjstalluw
powder, which gives off ammonia when heated, and is decomposed by water.

Bboxatb of Calcium. 2CaBrO* + aq. — Monoclinic tables or needle-shaped
prisms; ooP : ooP in the dino-diagonal section = 79° 66' ; odP2 : ooP2 in the same-
118° 22'; + F: + P in the same « 98° 41' : - P : - Pin the same « 106° 22' :
(JP oo) : (JP oo) in the same— 123° 33' (Rammelaberg). Dissolves at mean tempe-
rature in 11 pt water, forming a syrupy solution. The crystals gives off their water
at 180° G. ; at a stronger heat, oxygen is given off and bromide of caldum remains.

Bbomatb of CEnnTX. 2CeBrO» + aq. — Colourless laminse, which dissolve easily in
water, and do not effloresce over sulphuric add.

Bromatb of Chbomium. — Chromic sulphate decomposed by bromate of barima
yields a green filtrate, which decomposes by evaporation, giving off bromine and lesT-
ing a dark red residue, consisting almost wholly of chromic add.

Bbomatb of Cobalt. CoBrO»+3aq. — Hyacinth-red, transparent octahedrona,
soluble in 2*2 pts. water; the solution is decomposed by heat. The diy salt when
heated leaves a residue of oxide of cobalt The salt dissolves in aqueous ammonia,
forming a red liquid which turns brown in the air, and yields, after filtration, dark-
brown crystals, probably consisting of the bromat-e of ¥remy sfitseocobaltia,

Bbomatb' of Coffbb, 2CuBrO* + 6aq., crystallises from a concentrated solution in
light-blue or blue-green crystals, which are very soluble in water, do not effloresce m
the air, but crumble to a gre«nish-white powder in vacuo over siQphuric acid. They
retain a small portion of their water even at 180° C, but give it off at 200°, together
with part of the bromine. The aqueous solution mixed with a little ammonia yields

BROMIC ACID. 671

a light-blue precipitate, oonsistuig of a basic salt, 6Ca*0.6r*0*+ 10 aq., which at 200^
gives off its water and becomes greTish-green.

Amm(mio4iromate of Copper^ 2NH'.Ci]BrO', separates as a dark>blue crystalline
powder on adding alcohol to a solution of bromate of copper in excess of ammonia. It
oissolTes in a small qnantity of water, and is decomposed bj excess of water, with
separation of a basic salt. When heated it decomposes with deflagration.

BsOMATBS OF Ibun. — ^A solution of ferric hydrate in bromic acid, yields by evapora-
tion over sulphuric acid, a synip, which, after drying over the water-bath, leaves a
nearly pnre basic salt, 6Fe*O*JBi'0* + 30 aq., insoluble in water.

A solution of ferrous carbonate in bromic acid vields by evaporation in vacuo, octa-
hedral crystals of neutral ferrous bromaie^ FeBrO^ the solution of which easily de-
composea, with separation of the basic ferric salt.

Bbomatb of Lanthanum. LaBrO* -f 3 aq. — Amethyst-coloured crystals (? con-
taining didymium), which give off 20 per cent water at 160^ C.

Bbomaxb of liBAD. 2PbBrO* + aq. — Obtained by precipitation, or better by dis-
solving carbonate of lead in warm bromic acid; it then crystallises on cooling in small
shining prisms, isomorphous with the strontium salt. The crystals are permanent in
the air, and do not give off anv water over sulphuric acid ; -they dissolve in 15 pts.
water at mean temperature. The salt begins to give off oxygen and bromine at 180^ C,
a small quantity of brown peroxide of lead being formed at the same time, whereas at
a stronger heat, red lead or the yellow protoxide is formed ; the residue contains prot-
oxide with a small quantity of bromide.

BnoMATB OF LxTHitTX, LiBrC, czystaUises from a syrupy solution over sulphuric
arid, in needles, which effloresce in a dry atmosphere, but d^quesce when exposed to
the open air.

Bboxatb OF Maonbotjic. MgBrO' + 3aq. — Large regular octahedrons, which
dissolve in 1*4 pts. water at 15^ C. ; melt in their water of crystallisation at a moderate
heat, give off the greater part of it at 200^ C. ; and the last portion at a somewhat
higher temperature, oxygen being at the same time evolved.

Bboxatb of Manoaniisb is formed by dissolving manganous oxide in bromic acid,
bat decomposes very quickly.

Bboxatbs of Mbbcubt. — The mercuHc salt, B[i^BrO' + aq., is obtained by pouring
bromic aeid on recently precipitated mercuric oxide, as a white powder, which dis-
solves in 600 pts. of cold and 64 pts. boiling water. It dissolves also in excess of warm
bromic acid, and crystallises in small prisms on cooling. Hydrochloric acid dissolves it
with de«>mpositioi:k At 130^ — 140° C. it decomposes with detonation, yielding a
sublimate of mercnrous and mercuric bromide, and a residue of mercuric oxide ; but
giving off part of the bromine and oxygen as gas. Ammonia added to the warm
aqueous solution throws down a compound of mercuric bromate with oxide of dimercur-
ammonium, 2HgBrO'.(NH'Hg')'0, which does not yield an^ ammonia when treated
with potash. It is decomposed by heat with violent detonation.

Merevrous bromate, Hg*BrO' or HhgBrO", is obtained as a white powder by preci-
pitation, or br completely saturating bromic acid with mercurous oxide. From a solu-
of the oxide in a slight excess of Inromic acid, it separates by evaporation in shining
crystalline lamin». Water decomposes it, forming a basic salt, Hhg'0.2HhgBrO'. It
decomposes with detonation when heated.

Bboicatb of Nickel. NiBrO'+3aq. — Qreen regular octahedrons having their
summits replaced by cube-faces. Thin plates cut parallel to the cube-faces act
strongly on polarised light (M a r b a c h, Pogg. Ann. xciv. 412). The salt gives off water
when heated. It dissolves in 3*6 pts. of cold water, also in ammonia, and on adding
alcohol to the ammoniacal solution, a blue-sreen powder is precipitated, consisting of
amnumio'hromate of nickel, NH'.NiBrO*, or bromate of nickel-ammonium (SK^iyBrG*,

Bboxatb of PALLADitiK appears to be produced by dissolving palladous hydrate in
bromic add.

BtBOiiATB OF PzATiNDic. — ^Platiuic sulphats decomposed by bromate of barium
yields a yellow filtrate, which, when evaporated, gives off oxygen and bromine-vapour,
and deposits platinic bromide.

Bbokatb of Potassiuk. EBrO*. — Prepared by adding bromine to a warm,
moderately concentrated solution of potash, till the liquid acquires a permanent yel-
lowish tint ; the salt then separates almost completely on cooling, and may be purified
ficom bromide of potassium by washing with water, and recrystallisation. It forms
colourless anhvdrous crystals of specific gravity 3*271 (Kremers). From a hot solu-
tion it crystallises in needles, but by slow cooling it is obtained in four- and six-
sided plates, or in cubes with rounded summits ; b^ spontaneous evaporation in small
ssales^ or sometimes in dendritic masses. Acoordmg to Fritzsche, it always crystal-

672 BROMIC ACID — BROMIDES.

Uses in forms of the reffnlar flystem; bat, acoording to Bamnidgbeiir, in xfaombo-
hedrona, haTing the angles of the terminal edges « 86^ 18', and in formg dezifcd
therefrom. It dissolves in 321 pts. water at 0^ C, in 18'5 pts. at 10^, in 14*4 pfta at
200, ia. 7-6 pts. at 40^, in 4*4 pts. at 60^ in 2*9 pts. at 80^ and in 2 pts. at 100°
(Kremers, foffg. Ann. xcii. 497; xciy. 255; xcvii. 1 ; xcix. 25, 68). Aeeoiduig to
Fohl, 1 pt. of t^ salt dissolves in 17*5 pts. water at 17^ G. The OTStals deponted
from a solution, either perfectly neutral or slightly addnlated with acetic add, deoe*
pitate with violence at 300^ — 350^ C, and crumble to a powder, which, if tbrowa
into water, gives off bubbles of pure oxygen gas as it dissolves ; but the solution vhen
evaporated yields nothing but pure bromate of potassium, probably reproduced bj ab-
sorption of oxygen from the air. The crystals deposited from an alkaline lolatioo
decrepitate but slightly when heated, and the powder dissolves in water without per*
ceptible evolution of gas. (Fritssche, J. pr. Ch. xxiv. 286.)'

JBromate of potassium is decomposed by strong sulphuric acid, with violent decrs-
pitation and evolution of bromine and oxygen. T^en heated per te, it mdts at a teai-
peratnre above 360° C, and then decomposes, with evolution of oxygen, slowly at tint,
out afterwards with explosive violence, beginning to glow at one point, and then
quickly becoming incandescent through the entire mass. When mixed wiUi eamboa-
tible bodies, it explodes ^th great violence when struck or heated.

BnoicATB OF SiLVBB. AgBrO*. — Obtained by precipitation as an amorphoos vhite
powder quickly turning grey when exposed to light. According to Bammdabag, it
forms shming quadratic prisms (P : P in the terminal edges » 12 1° 68*7, in the latoil
edges s 86° 38), isomorphous with chlorate of silver. When rapidly heated, it cx-

f lodes with deflagration, giving off part of the bromine in the form of veUow fapovr.
t dissolves sparingly in water and in nitric add, more easily in ammonia, the adntioB
yielding by spontaneous evaporation, colourless prisms, which are quickly deeampoied
by water, and are very unstable even in the dry state.

Bboicatb of Stbontiux. 2SrBrO* + aq. — Small shining rhomboidal ptismfl, with
truncated lateral edges, isomoiphons with the barium-salt. Ratio of axes ■>
1 : 1*1642 : 1*2292. Indination of cUno-diagonal to prindpol axis » 89^. The
crystals dissolve in 3 pts. of water at ordinary temperatures ; do not lose weight over
sulphuric add, become anhydrons at 120° 0., and at a higher temperators are qniddy
resolved into oxygen gas and bromide of strontium.

Bboicatbs of Tin. — Stannic hydrate unites slowly with bromie add, and ibroi^
after drying over oil of vitriol, a vitreous mass, which loses 1 8 per cent in we^ht at
180° C. Stannous chloride forms a white predpitate with bromate of potasaiam.

Ubanio Bboicats. — ^A solution of uranic hydrate in bromie add yields, by en^Mn-
tion over oil of vitriol, a yellow unciystallisable syrup which decomposes by ev^nn-
tion, giving off bromine and leaving a basic salt

Bromatb of Yttbiuk. — Sparingly soluble in water; remains in the anhydrons state
when its solution is evaporated.

BsoMATB OF Zora ZnBrO* + 3 aq. — Beffular octahedrons modified by enbe-iSuei;
isomorphous with the magnesium-salt. It dissolves in 1 pt. water at oidinaiy tem-
peratures, is permanent in the air, melts in its water of oystallisation at 100° G^ ind
becomes anhydrous at 200°, but undergoes decomposition at the same time, giting off
bromine-vaponr and oxygen, and leaving pulverulent oxide of zinc The nit is de-
composed by a small quantity of ammonia, but dissolves completely in exoesa of an-
monia^ the solution yielding by evaporation over hydrate of potassium :

Amnumio-brofMEte of Wnc, or bromfOU of Mine^mnumiumf 2NH'ZnBrO' + 3 aq. m
small prismatic crystals, which, when exposed to the air, become moist and yellov, and
smell of free bromine. Water and alcohol decompose them with separation of hydnte
of zinc. At a gentle heat^ the salt decomposes with a loud hissing noise^ and gives off
bromine together with nitrc^en gas and water.

BXOmO BTMtVWMm Native bromide of silver. (See Silveb.)

S&OIIXBBB. Compounds of bromine with electro-positive radides. BrorniB^
like chlorine, is monatomic, 1 at of it being capable of uniting with 1 at. of fa^drc^
or other monatomic radide, 2 at. of bromine with 1 at of a diatomic radide, i^*
bromide of ethylene (C*H^)'^r', 3 at. of bromine with 1 at of a triatomie radicle^ tg,
bromide of glyceryl (C«H»)'^r». Bromine is less powerfully dectro-negative than
chlorine ; consequently bromides are for the most part decomposed by chlorine.

Broaaide of Bydroff«ii« B jdrolnromie or BromlijdFic Aold. HBr.— This
compound is gaseous at ordinary temperatures, and is composed of equal measures^
bromine-vapour and hydrogen united without condensation. It is not readily formed
by the direct union of its elements. A mixture of hydrogen and bromine-vapour does
not unite when exposed to the sun's rays ; neither does it explode when a red-hot vi'fr

BROMIDE OF HYDROGEN. 673

or a bnining taper is introduced into it; but combination takes place slowljjr in the
immediate neighbourhood of the hot body, and more quickly when the mixture of
bromine and hydrogen is passed through a red-hot tube, or when a platinum wire im-
mersed in it is kept red-hot by the electric current.
Prtparatum, — 1. By the action of water on tribromide of phosphorus :

PBr* + 3HK) - H»PO» + 3HBr.

A few grammes of bromine are introduced into the bend a of the apparatus {Jig. 113),
and in the bend b are placed some small pieces ^^ 2^3

ofpbosphorus, moistened with water, and sepa- ^'

rated by pounded glass. The bromine at a is
gently heated by a spirit-lamp, and the yapour
passing oyer to h forms bromide of phosphorus,
which is immediately decomposed by the
water, yielding phospnoious acid, which re-
mains in the tube, and hydrobromic acid,

which passes on through the deliyeiy:tube c, ^^ "^ *'

and may be collected oyer mercury. — 2. By decomposing bromide of sodium or potas-
sium with strong sulphuric acid :

2NaBr + H«SO* - Na«SO* + 2HBr.

The hydrobromic acid thus produced is, howeyer, mixed with yapour of bromine and sul-
phurous anhydride, produced in the manner represented by the equation :

2NaBr + 2H«S0* - 2Br + S0« + 2H»0 + Na^SO* ;

the bromine may be separated by agitation with mercury ; but the sulphurous anhy-
dride is not easUy remoyed. — 3. The aqueous solution of the acid may bs prepared by
decomposing a solution of bromide of barium with sulphuric acid diluted witii an equiU
weight of water, and distOling the filtered liquid. — 4. Also by passing sulphuretted
hydrogen into a mixture of bromine and water :

lOBr + 2H« + 4H«0 - lOHBr + BPSO« + S

The liquid is filtered to separate the precipitated sulphur, and the hydrobromic acid
separated from the sulphuric add by distillation. — 6. By the action of bromine on
hydriodic acid, on aqueous ammonia, and on many organic compounds, naphthalin,
for example.

i^yp^r^f.— Colourless gas haying a yery pungent odour, which excites coughing,
and a strongly acid taste. Beddens litmus strongly, and excites itching and inflam-
mation when applied to the skin. Fumes in the air more strongly than hydrochloric

acid. Specific grayity, by experiment, 2*71 (Lowig) ; by calculation — r — a 40*5,

compared with hydrogen, or 40*5 x 0*0693 « 2*801 compared with air. Liquefies
at -920 F. (--690 C), and soUdifies at -100° F. (-730 C.) (Faraday). It is
rapidly and copiously absorbed by water, forming a strongly acia solution, which, when
saturated, has a density of 1*29, and fUmes strongly in £e air. This saturated solu-
tion boils at a temperature below 1C0° C, giying off the gas, and is thereby rendered
weaker : a moro dilute add boils at a temperature aboye 100^, and a yeiy dilute add
becomes stronger by boib'ng.

Decompogitiana. — 1. The gas is not decomposed by heat alone. — 2. PotoMtum intro-
duced into it, eyen at ordinary temperatures, decomposes it completely, forming bro-
mide of potassium, and leaying a yolume of pure hydrogen equal to half that of tho
original gas. Tin produces the same effect when aided by a gentle heat. This reac-
tion determines the composition of the acid ; for the weight of 1 yol. of the gas (the
observed specific gravity) diminished by the weight of half a volume of hydrogen,
giyes a number which is yeiy nearly half the observed specific gravity of bromine
(5*54 according to Hitscherlich) :

2-71 - 5:«|?i - 2-68 - 1?«

Hence the gas is composed of equal volumes of bromine and hydrogen, united without
oondensation. — 3. The ^as, or its aqueous solution, is immediately decomposed by
eUorine, hydrochloric acid being formed and bromine separated, rocognisaHe by its
red colour. Iodine, on the contrary, does not decompose hydrobromic acid. Hence
the affinily of bromine for hydrogen is, under similar circumstances, less than that of
chlorine, and greater than that of iodine. — 4. The acid is also decomposed by oxygen
and by highly oxidised bodies. The aqueous solution turns brown on exposure to the
air, m>m separation of bromine, which romains dissolved. 'Sitrio acid idso separates
VOL.L X X

674 BROMIDES.

the bromine, eepeciallT on heating the liquid. The miztnie of the two adds dinohei
gold, like nitrohydrochloric acid. Strong sulphuric add deoompoaeB it» yidding svH-
phnrons anhydride, bromine, and water :

H«SO* + 2HBr - S0« + 2B?0 + Bi«.
With bromic acid^ it yielda water and firee bromine :

HBrO» + 6HBr - 3HH) + Br».

5. With metallic protoxide*, it forms water and a bromide of the metal: e.g.
2HBr -f AgH) » 2AgBr + HK). VfiMiperoxideB, a similar decomposition takes place,
attend^ a&o with eyolution of bromine: e,g. 2HBr -i- MnO » l&iBr -i- HK) ■¥ Br.

Combinationa. — Hjdrobromic acid unites directly with ammonia NH', fonning
hydrobromate of ammonia, NH'.HBr, or bromide of ammoninm, NHfBr. Simihrij
with the compound ammonias, methylamine, eihylamine, &&, and with pkotphorttttd
hydrogen. The aoueous solution dissolyes certain metallie oxides, viz. the alkalis and
earths, forming solutions, which may be supposed to contain hydrobromates of
those oxides. It unites with many hydrocarbons, e.g, with oil of tmpentineb Isiming
the compound G*«H**.HBr.

Brofiiid«Sf XetAlUo* HBr. — Bromine unites directly with most metala. Po-
tassium, arsenic, antimony, and tin unite with liquid bromine, producing Tivid earn-
bustion ; bismuth, iron, and mercury combine with it at ordinary tempentures
without combustion ; but on the application of heat, combustion takes plaix. Gold
combines gradually with bromine at ordinary temperatures ; platinum does not. With
many metals, the application of heat is necessaiy to induce combustion. Bromides are
also formed by the action of metals on hydrobromie add gas (p. 672). Vapour of
bromine passed oyer ignited potash, soda, baryta, or lime, forms a bromide of the
meitJ and eliminates the oxygen ; bromine decomposes oxide of silrer, even at ordi-
nary temperatures. Carbonates are also readily decomposed by it

Nearly all bromides are soluble in water ; bromide of lead however dissolres Tciy spar^
ingly, and bromide of silver and mercurous bromide are (fuite insoluble. The soluble
bromides may all be produced by the action of hydrobromie add on the oorrpsponding
oxides or carbonates ; and on evaporating the solutions, water is in most eases giveo
off, the metallic bromide remaining. Some of them, however, vi& the bromi£a of
magnesium, aluminium, and the other earth-metals, are more or leas deocHapoeed
during the evaporation of the solutions, giving off hydrobromie add and leaving a
mixture of bromide and oxide of the metid.

Metallic bromides are solid at ordinary temperatures ; most of them fuse at a
moderate heat, and volatilise at higher temperatures. They strongly resemble the
chlorides. The bromides of gold and platinum are decomposed by mere exposure to
heat ; many others give up their bromine when heated in contact with the air. Cfa]o>
rine, with the aid of heat, drives out the bromine and converts them into chlorides.
Hydrochloric add also decomposes them at a red heat giving off hydrobtomic add.
Strong sulphuric or nitric add decomposes them, with evolution of hydrobromie add,
which, if the sulphuric or nitric acid is concentrated and in excess, is partly deeom-
posed, with separation of bromine and formation of sulphurous anhydride or nitrie
oxide (p. 672). Bromides heated with sulphuric add and peroxide of manganese or
chromate of potassium, give off free bromine. If the bromide is quite pure, the
evolved bromine is completely decolorised by ammonia; but if chlorine is also prnent,
cholorochromic acid distils over, together with the bromine, and the distillate then
forms a yellow liquid with ammonia.

Bromides in solution are easily decomposed by dilorine, either in the form of gas
or dissolved in water, the liquid acquiring a red or reddish-yellow colour, according to
the quantity of bromine present ; and on agitating the liquid with ether, that liquid
dissolves the bromine, forming a red solution, which rises to the suiikce. (See Bio-

MINB.

Soluble bromides give with nitrate of silver, a white predpitate of bromide of aflver,
greatly resembling Uie chloride, but much less soluble in'ammonia ; insoluble in hot
nitric acid Mercurous nitrate produces a yellowish-white predpitate ; and acetate of
lead, a white precipitate much less soluble in water than the chloride. Nitraie of pal'
ladium produces in solutions of bromides not containing chlorine, a black predpitate
of bromide. Chloride of palladium produces no predpitate ; ndthear does the nitrate^
if soluble chlorides are present

Bromides of OrfABteltedleles. Bromine unites with organic radides both basic
and acid The compounds are formed in the same manner as the corresponding
chlorides, which they also resemble in most of their properties, though tney are
less volatile. They contain, in two volumes of vapour, one, two, or three volumes of

BROMroES — BROMINE. 675

bromine-yaponr, according as the organic radicle which they contain is mono-, di-, or
tri-atomie, «l g, :

2 ToL bromide of trityl CH^r contain 1 roL bromine
„ „ tritylene (C»H«)'3r* „ 2 toL „

glyceryl (C»H»)'-Br» „ 8 vol „

1. The hrcmidu of the ahohot'tadieleSt iydrobromio or bromhydrie ethers, are
obtained by distilHng the corresponding alcohols with hydrobromic add or bromide of
phoaphoma: e,p.:

C*H».H.O + PBr» - C*H*Br + HBr + PBr»0
Alcohol. Bromide Oxvbro-

or ethyl. mlaeof

lihoephorat.

Distilled with alkalis, they yield the corresponding alcohol and a bromide of the
alkali-metaL

2. The hrwmdee of aeid-radidee are produced by the action of bromide of phosphorus
on the ooiresponding adds, or by the action of chlorides of acid-radicles on certain
metallic bromides : e. g, bromide of acetyl^ CH*O.Br ; bromide of succinyl, (C*H*0*)"Br*.
AUcalis decompose them, with formation of a metallic bromide, and a salt of the cor-
reqKiiiding organic add, e,g, :

(C*H*0«)-Br« + 2KH0 - C«H«0»:K«.0« + KBr.

Bromide of Succinate of

racdnyl. poUMlum.

3. The bromidea of aldehyde-^ttdidea are monatomic bromides of the general form,
OH*-*Br : e,g. brojnide of vinyls CH'Br. They are isomeric with the monobromi-

Bated diatomic alcohol-radicles, e,g, C*H*Br, with bromotritylene, G*-d . They are

YoUtile liquids, obtained by the action of alcoholic potash on the bromides of the
diatomic aloohol-radides : their properties and reactions are analogous to those of the
corresponding chlorides {q. r,)

4. Many other organic radicles, such as oil of turpentine, its isomers and homo-
lognes, likewise nnite with bromine and with hydrobromic add, forming definite com-
pounds, sometimes liquid, sometimes crystalline, e,g, bromide of c({jputene, C'*H*'Br*;
hydrobromaU of turpentine-oU, Ci*H>*.HBr, &c.

See the neoct artide.

The name of a doubtful compound, which Erdmann ob-
tained, together with bromisatin and dibromisatin, by the action of bromine on indigo.
It was resolyed by ootash into bromindoptic (bromophenissic) add, and a Tolatile
body, called by Erdmann bromindamite, but doubtless identical with tribromo-
pheoylamine. (Handw. d. Chem. 1** Aufl. iv. 22.)

wniMlfW %mbolBT. Atonde weight 80. — This dement was discovered in
1826 by Balard, who extracted it from the mother-liquor of the salt-marshes of Mont^
pelHer. It exists in sea-water ; in the water of many salt-sprin|;8, especially in that
of Theodorshall, near Kreusnach in Prussia, whence a large portion of the bromine of
commerce is obtained ; and, together with iodine, in the ash of sea-weed (eoude de
tareeh), whence laiscr quantities are extracted; also in sponges and many marine
M»i»it1a As bromide of silver, it is found native in Mexico and Chili, and at Hnel-
goeth in Bretagne ; very small quantities are found in SUesian sine-ore and in English
rock-salt^

H-^HiraHon. — 1. From the mother4iguor of eeOrXDOter or aaline-^pringe. After these
waters have been freed by crystallisation from the greater part of the chlorides and
sulphates of sodium and potassium, the remaining lK|uid contains bromine, chiefly in
the form of bromide of mapinesium. This liquid is mixed in a retort with peroxide of
mannneee and hydrochloric acid, and distilled. Chlorine is then evolved in the liquid,
and decomposes the bromide of magnedum, setting fr«e the bromine, which distils
over into the receiver, in the form of a heavy dark-red liquid, surmounted by an
aqueous solution of bromine. — 2. From the Ttudher-liguor of varee. This liquid con-
tains iodine and bromine, in the proportion of about 1 pt. bromine to 8 iodine. The
iodine is first predpitated either by passing chlorine gas into the liquid, till a sample
taken out gives no predpitate either with chlorine-water or with iodide of potassium ;
or it is predpitated as free iodine and cuprous iodide, by adding cupric sulpoate to the
liquid: (Cu^O« -f 2NaI - Na*SO' + Cu<I -k- I). The remaining liquid ib then mixed
with peroxide of manganese and strong sulphunc add (the requisite proportions being

XX 2

€76 BROMINE.

first determined by trial on a small quantity) and distilled. The bromine dien

over as before, the decomposition being effected in the manner shown by the eqnatiou :

2MgBr + 2MnO + 2H«S0« - Br» + Mg«0« + Mn*SO« + 2H«0.

The bromine which collects at the bottom of the receiver in either mode of preparation,
is separated from the sapersaturated aqueous solution by means of a tap-funnel, and
further purified by distillation in contact with chloride of calciom. The aqneous
solution IS shaken up with ether ; the red ethereal solution of bromine which rises to
the top is treated with caustic potash, till its colour disappears, whereby bromide and
bromate of potassium are produced ; the liquid is eyaporated to dryness ; and the
residue is ignited in a crucible, to convert the bromate EBrO*, into bromide KBr.
The whole quantity thus obtained is decomposed by distillation with peroxide of man-
ganese and sulphuric acid, whereby the remaining quantity of bromine is obtained in
the free state.

Commercial bronune is generally contaminated with chlorine, derived cither from
that which is used to separate it, or from the mother^liquoritsell It may be parifled
by saturatixig it with hydrate of barium, whereby bromide, chloride, bcomate, and
hypochlorite of barium are formed ; evaporating and igniting to decompose the oxygen-
salts ; and treating the residue with alcohol, which dissolves the bromide of barium
and leaves the cUoride. The pure bromide is then decomposed witli sulphuric acid
and peroxide of manganese, as above.

Properties. — ^Bromine is, at ordinary temperatures, a liquid of a deep brown-red eoloiar.
It has a peculiar irritating, disagreeable odour ; whence its name {0pAf»4n\ and a re-
pulsive taste. It is highly poisonous ; a drop placed on the beak of a bird is sufficient
to destroy life. Specific gravity 2-966 (Balard) ; between 2'98 and 2*99 at 15^ C.
(Lo wig) ; 3-1872 at (P C. (Pierre). It is a non-conductor of electricity. At —22** C.
it solidifies, forming a hard, brittle, laminated mass, having a dark l^d-grey colour,
and semi-metallic lustre: it retains tiie solid state for a long time, even at — 12^ C
It is very volatile ; a few drops thrown into a large flask speedily fill it with red
vapours. It boilsat 63° C. (Pierre) ; at 68° (Andrews) ; at 45° (Lowig). Yapoor-
density 6'6i (Mitscherlich); by odculation, 80 compared with hydrogen; 6'o44
( «s 80 y 0*0693), compared with air.

Bromine dissolves sparingly in water, more readily in alcohol, and in all proportions
in ether. With water at 0° C. it forms a solid hydrate, Br . 6H'0, which is not decom-
posed between 16^ and 20^.

Bromine resembles chlorine in many of its properties. It has a puwnful affinity for
hydrogen, though not quite so strong as that of chlorine, and hence it acts ip.th enery^y
upon many organic substances. It is a powerful bleaching agent, and corrodes wood
and cork, first turning them yellow. A small quantity of it imparts a transient yel-
low colour to the skin ; a larger quantity stains it permanently yellow, then brown,
and a still larger quantity produces immediate corrosion and violent inflammation. It
colours starch orange-yellow. It decomposes vapour of water when passed with it
through a tube heated to bright redness, yielding hydrobromic acid and oxygen. A
burning taper introduced into vapour of bromine, bums for an instant with a green
light, and is then extinguished

Bromine decomposes phosphoretted hydrogen, sulphydric acid, hydriodic acid, and
metallic iodides, but the resulting bromine-compounds are decomposed by chlorine.

Bromine acts readily on many organic compounds, removing part of the hydrogen
in the form of hydrobromic acid, while another portion of bromine takes the place of
the hydrogen thus abstracted, 80 pts. bromine being always introduced for emy
1 pt of hydrogen removed. In this manner, bromacetic acid, CH'BrO', and a con-
siderable number of other brominated compounds, are formed.

Bromine unites with all the elementary bodies, and with many compound radidea.
In all its eompounds, except those with chlorine, fluorine, oxygen, and perhaps sul-
phur, it plajTS the part of the chlorous or electro-negative element. In this respect,
it is intermediate between chlorine and iodine, expelling the latter from its combina-
tions with positive radicles, and beine itself expelled by the former (see Bsoiodbs,
p. 672). We shall here describe otSj those compounds in which the bromine is
electro-positive, viz. the chlorine, fluorine, oxygen, and sulphur-compounds : the othen
are described under the several positive radicles.

BSOMlVBf CB&OKZBB OF. Bromine absorbs a large quantity of chlorine
gas, forming a reddish-yellow, mobile liquid, very volatile, and giving off dark-yellow,
strong-smelling, and tear-exciting vapours, which exert a powerful Ueadiing action,
and in which metals burn quickly to chloride and bromide.

When chloride of bromine is mixed with a small quantity of water, and cooled to
0^ C, or when gaseous chloride of bromine is passed through a glass tube moistened

BROMINE : DETECTION AND ESTIMATION. 677

with water, tlie hydrated chloride of bromine is formed, which erystallifles in
needles or laminae, and melte at 7^ C. to a light yellow liquid. It is decomposed by
ammonia, forming nitrogen gas, chloride of nitrogen, and bromide of ammonium.
Chloride of bromine dissolves with yellow colour in water. The same solution is ob-
tained by dissolying bromine in saturated chlorine-water ; it has the odour and bleach-
ing action of chloride of bromine; decomposes in sunshine into hydrochloric and
bromic acids, and is decomposed in like manner by aqueous alkalis, yielding a chloride
and a bromate of the alkali-metaL The aqueous solution is decomposed by ether,
which separates and dissolyee the bromine. (Handw. d. Chem. ii. [2] 476.)

BROMCm* SBTXCTZOV AVB BSTZSEAiTZOV OF. 1. Reactions. —
Free bromine is recognised by its odour, the deep-n'd colour of its rapour, and the
orange-yellow colour which it imparts to gelatinous starch. When it exists in aqueous
solution in too small quantity to be recognised immediately, it may be separated by
shaking up the liquid with ether, and proceeding as described below.

Bromine in the state of hydrobromic acid or a soluble metallic bromide, is detected
by the reactions already described (pp. 672, 673). Small quantities of bromine are most
easily recoc;nised by cautiously adoing chlorine-water till the solution assumes a red
or yellow tint ; if too much chorine be added, chloride of bromine will be formed,
which 18 colourless. On shaking the solution with ether, that liquid dissolves the
bromine, and rises to the surface in the form of a red stratum. This may be separated
by a pipette, or tap-funnel ; neutralised with potash, which decolorises it, converting
the bromine into bromide and bromate of potassium ; and evaporated to dryness in
a porcelain cmcible. On igniting the residue, to convert it all into bromide, then intro-
ducing it into a test-tube, and heating with sulphuric acid and peroxide of manganese,
bromine is given off in led vapours, which, if led into a s<^ution of starch, colour it
orange-yellow.

The presence of chlorides does not interfere with this reaction ; if, however, the
quantity of chlorine is veiy large compared with that of the bromine, as in saline
waters, it is best to concentrate the solution till the greater part of the chlorides crys-
tallise out^ and search for bromine in the mother-liquor.. If iodine is present, it must
first be removed, either by precipitation with chloride of palladium, or by first adding
just sufficient chlorine-water to ^xrecipitate the iodine, which is sure to be set free
before the bromine : in fact, bromine itself separates iodine firom its compounds ;
but the removal of the iodine is absolutely necessary, aa its deep violet vapour
would disguise the colour of the bromine, unless the quantity of the latter greatly
predominated.

The methods of decomposing insoluble bromides will be given further on ; likewise
the methods of separating bromine from phosphorus, and other non-m{>tallic elements.
Bromates are reduced to bromides, either by ignition or by treatment with sulphurous
or sulphydric acid.

% Quantitative Estimation, — When bromine is present in a solution in the
form of a bromide, it ma^ be precipitated by nitrate of silver, the precipitate of
bromide of silver being ignited in a porcelain crucible, with the same precautions as
the chloride (see Cblorink). It contains 42*65 per cent, bromine. If the solution is
alkaline, it must be aeididatod with nitric acid, added after the precipitation by
nitrate of silver; if it were added before, a portion of the bromine might be set free
and lost.

Insoluble bromides, e.g, bromide of lead^ and cuprous bromide^ may be decomposed
by suspending them in Water, and pa£(sing sulphuretted hydrogen through the liquid.
The metal is then converted into sulphide, while hydrobromic acid remains dissolved
together with excess of sulphydric acid. This excess may be removed by addition of
ferric sulphate, which precipitates sulphur, and in the filtered liquid the bromine may
be estimated, as above, Vy precipitation with nitrate of silver. Bromide of silver may
also be decomposed by fusion with carbonate of sodium, or, better, with a mixture of
carbonate of sodium and carbonate of potassium in equivalent proportion, in a porcelain
crucible. The silver is thereby reduced to the metallic state, and may be weighed
after washing. The bromine is then estimated by loss.

Another method of decomposing bromide of silver, is to treat it with dilute sul«
phuric add and pure metallic zinc The silver is then reduced by the nascent hydrogen,
and the bromine passes into the solution as bromide of zinc The silver may then be
washed and weighed as before. This method, however, is not quite exact (see
Chlobhix). — Mereurous bromide mav be completely decomposed by a solution of pure
caustic potash, a solution of bromide of potassium beine formed, from which the
bromine may be precipitated by nitrate of silver with addition of nitric acid.

Many oxybromides which are insoluble in water, are soluble in nitric acid. The
add ahoiild be dilute^ and if heat is required, the materials must be placed in a flask

XX 3

678 BROMINE: ESTIMATION.

haying a glass stopper, and the heat kept as low as possible, otSurwise bromioe vill
escape. The bromiue may then be thrown down as bromide of Bilver.

VoUUUe bromides^ such as the bromides of sulphur, phosphorus, arKoic, and tsU-
mony, are completely decomposed by water, the bromine bem^ oonrerted into hydn-
bromic acid, from which it may be precipitated by nitrate of silyer.

Bromates must be reduced to bromides by sulphurous or sulphydrie add; Uie
bromine may then be precipitated by silyer-solution, after the excess of the ndodng
agent has been remoyed by a ferric salt. Bromates may also be oonyerted intobramidei
by ignition.

The quantity of free bromine in a solution, is estimated by treating it withexceai of
ammonia, whereby it is completely conyerted into bromide of ammonium, with ero*
lution of nitrogen. The diluted solution is then treated with nitrate of siher.

Estimation of Bromine in preaence of Chlorine. — There is no known method of
effecting a complete separation of these elements, and when they occur together, their
amounts must be estimated by an indirect method. This is effected by prmpitfttiiig
them both together by nitrate of silyer; fusing and weighing the entire precipitate
in a porcelain crucible ; then remelting it ; talong out a oonyenient portion on the
end of a glass rod ; cutting it when cold into small shayings; introducine them in-
to a bulb- tube; and igniting them, after weighing, in a current of dry chlorine. The
whole of the bromine is then expelled, proyided the stream of chlorine is kept op
for some time, and nothing but chloride of silyer remains. This is weighed, and from
its weight, and that of the mixture of chloride and bromide before decomposition, tbe
quantities of chlorine and bromine may be found. For the difference of the veighta
(d) is clearly the difference between the weight of the bromine expelled and that of
the chlorine which has taken its place ; and for eyery 80 pts. of bromine e^qnlled
35*5 pts. of chlorine haye come in : hence we haye the equations :

Br - CI OS <i :

Br JO^
a ■ Z6-6

80
whence : Br - ^^ _ ^,^ d - 1-7W i

that is to say : to find the quantity of bromine, mtdt^y the differenee of the weighti
by 1-796.

If the quantity of bromine is very small compared with the chlorine, this method
does not giye exact results. In that case, it is necessary to concentrate the hrvmrnit^
that is, to increase the proportion of it in the precipitate subjected to the eiqwrime&t
Now when a mixture containing a large quantity of soluble diiloride with a small pro-
portion of bromide, is treated with about one-sixth of the quantity of nitrate of eilxer
required for complete precipitation, the whole of the bromine is precipitated, together
with a portion of the chlorine. The liquid must be briskly agitated to cause the
precipitate to settle down, but no heat must be applied. The precqntate is then to
be ignited, weighed, and decomposed in a stream of chlorine in the manner just de-
scribed. The remainder of the chlorine, now free from bromine, is precipitated as
chloride of silyer in the usual way. Another method of concentrating the bromine in
a mixture of chloride of sodium containing a small quantity of bromide, is to tmt
the dry mixture with yery strong alcohol, which dissolyes the whole of the bromide of
sodium, but only a small portion of the chloride. The filtered alcoholic solution is
then eyaporated, the residue is dissolyed in water, and the bromine and chlorine ue
precipitated by nitrate of silyer and estimated as before. To estimate the qoantit/
of bromine in sea-water or a brine-spring, the liquid must be eyaporated to diynen, s
weighed quantity of carbonate of sodium haying been preyionsly added to prevent the
loss of bromine and chlorine which might arise from the decomposition of thechlonde
and bromide of magnesium during the eyaporation, and the d^ residue treated with
alcohol as aboye.

Estimation of Bromine in presence of Iodine^ — ^The iodine is precipitated hj ehkmde
of palladium (or by the nitrate, if cMoiides are present, p. 674), the excess of pal-
ladium removed by sulphuretted hydrogen, the excess of this last reagent by mtne
acid or a ferric salt, and the bromine then precipitated by nitrate <tf silyer.

(For other modes of estimation, see Chlobikb and Iodinb.)

Field (Chem. Soc. Qu. J. x. 234) has shown that chloride of silyer is eompletdT
decomposed hj digestion with solution of bromide of pK>tassium, the chlorine sad
bromine diangin^ places ; and that both bromide and chloride of silyer are decomposed
in like manner by iodide of potassium. Hence, if a solution containing chlorine,
iodine, and bromine, be diyidea into three equal parts ; eadi portion predpitBted br
nitrate of silyer ; the first precipitate dried and weighed ; the second digested vith
bromide of potassium, then dried and weighed; and the third with iodide of potss*

BEOMINE: FLUORIDE. 67f)

nam, then dried and weighed, the reUtive quantities of the three elements may be
determined bj an extension of the method of calculation above given (see also p. 224).
Let the weights of the three precipitates be w, w\ and w" ; also let the atomic weights
of chloride, bromide, and iodide of silver be c, 6, and t respectively, and the onknown
quantities of diloride, bromide, and iodide of silver, x, y, and z ; then we have the
three equations :

« + y + * — fp

t t

-« + -ny + jr -I 10"

The first and second give : * — ^. ^ — '

Sabstituting this value in the second and third, thej become:

whence : y ■■ ^^. " ^J

t — o

and: <f »« — (« + y).

For the volumetric estimation of bromine, see An altsis, YoLViaTBio (p. 267). For
the estimation of bromine in oiganic compounds, see Analysis, Oboanio (p. 247).

3. Atomic Weight of Bromine. — The older determinations of the atomic weight

of bromine were much too low. Balard estimated it at 16% Liebig at 76*2, Bezzelius

at 78*2. The most exact determinations are due to Marignac (Biblioth. univ. de

Ctenive, xlvL 867), who found : 1. That 100 pts. pure silver dissolved in nitric add

and precipitated by bromide of potassium, yielded, as a mean, 174'066 pts. bromide of

silver ; whence, the atomic weight of silver being 108, that of bromine is x « 74*065 x

108

_. wm 79*91. — 2. That 100 pts. silver required for precipitation, 110*36 pts. bromide

of potaasiam; whence if Ag «- 108 and E — 39*1, we have 100 : 110*36 » 108 :
89*1 + x\ whence s » 80*09. — 8. That 100 pts. bromate of potassium give off by
isnition, on the average, 29*723 pts. oxygen, whence Brae 79*97. The mean of all
these results is veiy nearly Br «- 80, wmdi is the number now universally adopted.
Dumas arrived at the same result by igniting bromide of silver in chlorine gas, and
determining the difference of weight mereby produced.

XBOmw^ VXiVOKDa or. Fluorine is readily absorbed by bromine. The
resulting compound, according to Lees en (PhiL Mag. Dec. 1844, p. 620) is liquid,
easily soluble in water, and does not sensibly attack glass. It has been used as a
means of accelerating the taking of photogn^hic pctures by the electric light (Compt.
rend, rmriii. 601.)

aBOMIBJ, OJnroaw-AOXBS of. The series of oxyeen-componnds of bro-
mine is by no means so complete as that of chlorine. No anhycux>us oxide of bromine
is known, and of the acids, only one has been obtained in the separate state and
thoroughly examined, viz. Bromic acid, HBrO*, already describea (p. 669). AH
attempts to prepare a perb romic acid, analogous to perchloric acid, HcIO*, have been
unsuocessfm; but the existence of hypobromous acid, HBrO, is rendered probable
by many experiments, though neither the add itself nor any of its salts, have yet
been obtained in definite form.

When mercuric oxide is added to bromine-water, a sparinglv sobi^le oxybromide of
mercury is formed, together with a bleaching liquid, which, oy dLstillation in vacuo, 'v

Jields a liquid supposed to be hypobromous acid (Balard). According to Gay-Lussac,
ypobromous anhydride may be obtained in the gaseous state in the same manner as
hypochlorous anhydride. (See Chlobinb, Oxidbs of.)

when bromine is added to cold dilute aqueous alkaUs, a metallic bromide is formed,
together with a very small quantity of bromate, and a liquid, which does not smell of
bromine, bleaches litmus and indigo and vegetable colours in general, and g^Kes off
nitrogen in contact with ammonia. On heating the liquid, no bromine is evolvecL but
a bromate is formed and the bleaching power is destroyed. These phenomen Aare
precisely analogous to those which are exhibited when chlorine is dissolved in ^^
alkaline solutions. (See Htfobbomovs Acm.)

680 BROMIODOFORM— .BRONZITE.

sa&BWZOB OF. See SBLBTtnii:, Bboxxds of.

BROMZn, BV&VBZBB OV. When bromine is brought in contact vith
flowers of sulphnr at ordinary temperatures, a dark brown, faming, oily liquid is formed,
having an odour like that of sulphide of chlorine. It is not ^tered by cold water ;
but water at 10^ C. decomposes it with slight explosion, forming sulphuric, hydro-
bromie, and sulphydric acids. When it is distilled, the first third of the distillate
appears to consist of Br^S* while the liquid remaining in the retort is a mixture of
this compound with another sulphide of bromine, and, eren when the distiUadon is
completed, there still remains a viscid liquid containing bromine. (H. Bose^ P<'S&
Ann. xxviii. 550.)

BBOMZOBOFOBM. CHBrT. — This compound is produced by treating iodo-
form with bromine. It is a colourless liquid, which solidifira to a camphorated mass
at 0^ C. ; melts at + 6^ ; is very volatile ; has a penetrating odour and saccharine taste.
It may be regarded as dibrominated iodide of methyl. (Serullas, Ann. Ch. Phja.
[2] xxxiv. 225 ; xxxix. 97. — Bouchardat^ J. Pharm. xxiii. 10.)

BBOBIISATZO ACZB. See Is^no Acm.

r. See IsA.Tnr.
Native bromide of silver, found in Mexico and in Chili. (See Silvsk,
Bromide of.)

A.OZB. See CrrBic Acm, Bbcokpositions of.
Syn. with Alstonitb.

BBOMO-COIKPOUWB8 or SBOSnVATBB COBKFOmniB. Compounds
resulting from the substitution of bromine for hydrogen, chiefly in organic bodies.
They are produced by the action of bromine or of bromide of phosphorus on alcohols,
acids, hydrocarbons, &c Most of them are described under the several principial
compounds, e, g. Bboxobbvcims under BBUCiini, &c.

BBOMOVOBML CHBr*. — Produced by the simultaneous action of bromine
and caustic potash on wood-spirit, alcohol, or acetone ; idso by the action of bfomioe
on aqueous citric or malic acid; and by decomposing bromal with alkalis. It is a
limpid liquid of specific gravity 2*13, having an agreeable odour and saccharine taste.
It is less volatile than chloroform, very little soluble in water, to which, however, it
imparts its taste and odour ; soluble in alcohol, ether, and essential oils. It dissolves
small quantities of sulphur and phosphorus, and a large quantity of iodine. It boms
with difficulty. When its vapour is passed through a red-hot tube, it is resolved into
charcoal and bromine-vapour. Boiling potash-ley decomposes it mora easilv than
chloroform, yielding formate and bromide of potassium. (Lowig, Ann. Ch. Fhaim.

chloroform, yielding formate and bromide of potassium. (liowig, Ann. Ch. Fhaim.
iii. 295.— Dumas, Ann. Ch. Phys. [2] Ivi. 120.)

BBOKOPXCBXir. CBr^O*.— A product obtained by distilling picric add with
hypobromite of calcium (p. 923).

8B0M08AMXBB. See SALiCTLAionB.

See Citric Aero.
Decompositions by bromine.

BBOMini. A genus of grasses. The ashes of Bromua crectua and Bromus maffig

have been analysed by Way and Ogston (Journal of the Boyal Agr. Soe. [2] xii.
530). 100 pts. of Br, erectus (air-dried) yielded 59 6 per cent water, and 2*1 iiBh ; of
Br. mollis, 70*6 per cent water and 1'4 ash.
100 pts. of ash were found to contain :

KSO NftSO Ca*0 Mg*0 Fe^oa S03 SO* { CO* FSQS Ka VmCI
Br. erectus. .90*3 .. 104 0*0 OM 6*5 SH-5 0>5 7*5 10-6 1*4
Br. mollis . .80*1 O-S 6« 2*6 081 4*9 333 9' I 9-6 . . a*l

Kative bromide of silver. See Silveb.

An alloy of copper and tin. See Copfeb.

SchUliTapar, DiaUage fibro4aminaire, — A mineral belong:ing to
the augite family (p. 476). It is massive, with laminar structure inclining to fibrous.
Colour varying from yellowish-brown to pinchbeck>brown. Lustro firom mother-of-
pearl to bright adamantine (pseudo-metallic). Harder than felspar. Specific gravity
3*201 to 3*25. Like all the augites, it is a metasilicate, its general formula being
M'SiO' or M'O.SIO^ tbe M*0 denoting lime, magnesia^ manganous oxide, and ferrous
oxide in variable proportions, the magnesia, however, predominating. It is found in
large masses in beds of serpentine.

Delesse examined a mineral firom the serpentine of Houx in the Vosgea, which
resembled bronzite in its large amount of magnesia (56*33 SiK); 1*50 MnK)* and
Cr«0«; 6-73 Fe«0 ; 31*93 Mg*0; 1 40 Ca«0 ,* 211 losd by ignition) ; but differed fifwn

BROOKITE — BRUCINE. 68 1

it in not poweanng tihe same metAllic lustre and mnehbeek-'brown oolonr, and in being
lesB distinctly deavable, especially parallel -to oP; specific graxity 3*154 (Ann. Min.
[4] xTiii. 318). (For other analyses of bionzite, see Qm. Handb. iiL 403, 404 ;
Cxarrett, Sill. Am. J. [2] Z7. 333; Kjernlf, Bischofs Lehrb. d. chem. a. phys.
Oeolog. iL 1496.)

BXOOXITB. JuriniU. Arkansite, — One of the forms of native titanic anhydride
TiO\ which is trimoiphoos. The crystals belong to the trimetric system, and generally
exhibit Teiy complicated combinations, among which we may assume, as the primary
form, tJie pyramid P, in which the lengths of the brachydiagonal, macrodiaconal, and
principal axis, are to one another, as 0'5961 : 1 : 0*5558. Angle of the terminal edges
in the brachydiagonal section « 135^ 46'; in the macrodiagonal section » 101^ 37';
and of the lateru edges » 94^ 44. The crystals exhibit, together with P, the faces
ooji^ao and oo]^2, luewise other p3rramid8 and horizontal prisms; and are often
rednced to the tabnUr form by preaominance of the faces oo {^ od. GleaYage parallel
to 00 ]^ 00. Yellow, red, brown, or black, with adamantine or semi-metsllic Instre.
Transparent to opaque. Streak yellowish-white. Hardness wm 6'6 to 6*0. Specific
mritj a 3*85 to 4*22. Brittle. It is found at Oisans in Dauphin^, at Tremadoc in
Wales^ on the St. Gothard, in the Yaloisina and the (hisemthal in Switzerland, at
Minsk in the Ural, and at Magnet Core in Arkansas. The crystals firom the last-
mentioned locality, were at first regarded as a distinct specifi8,callea Arkansite. (K opp,
Handw. d. Chem. ii [2] 521 ; Kiystallographie, p. 256.)

BS08SITB. A variety of bitterspar from the Brossa valley in Piedmont and
other localities, distinguished by a rather large amount of iron. A specimen from
Traversella, analysed by Hirzel (Zeitsch. t.rhaxm. 1850, p. 24), yidded 11*13 per
cent, ferrous carbonate.

BBOmo Jl JTA'TIA TZVCTOXXA or Mortis Hnctoria, — The plant which
yields yellow-wood. (See Morus and MoBiNTAiimc Acid.)

BJRUWJi MMBMJMB. — The fruit of Subus /ructicostis. See Buiius.

BSVCm. Canimarine, Vomietne.—C^B^'NK)* + 4HK) (Pelletier and Ca-
Teuton (1819), Ann. Ch. Phys. [2] zii. 118; xxvL 53.— Pelletier and Dumas,
ilfid. xziv. 176. — Corriol, J. Phaim. xi 495. — ^Liebiff, Ann. Ch. Phys. [2] xlviL
172; Ann. Ch. Pharm. zxxi. 50.— Begnault, Ann. Ch.Phys. [2] Ixviii. 113). This
vegetable alkaloid exists, together with stzychnine, in nux vomica (the seed of Strych'
nos nux ifomica\ in the bean of St. Ignatius (the seed of 8trychno» IgnatU), in the
wood of StrychnoB Colubrina, and in wp<u tieute, an extract prepared from the bark of
the Strychnos tieute^ and used by some of the natives of the East Indian Archipelago,
for poisoning their arrows. It also exists in large quantity, and unaccompanied by
strychnine, in false angustura bark, originally supposed to be the bark of Jarttcia an*
Udytenterica, but now ascertained to belong to a species of strychnos, probably Stryeh-
nos nux vontica.

Preparation. — 1. From/tUse angustura hark, — The pulverised bark is treated with
ether to remove fatty matter, then digested in strong alcohol; the dry alcoholic ex-
tract is dissolved in water ; the colouring matter precipitated by subacetate of lead ; the
excess of lead removed by sulphuretted hydrogen ; and the liquid, which contains the
brudne in solution, is boilea with magnesia, again filtered and evaporat<ed« The
brucine is thus obtained in the form of a granular mass, generally coloured. To
purify this product, it is saturated with oxalic acid ; the oxalate of bracine is washed
with absolute alcohol cooled to O^C. which dissolves the colouring matter, then
redissolved in water, and decomposed by lime or magnesia ; and the brucine thus set
free, is redissolved in alcohol and crystallised by slow evaporation (Pelletier and
Caventou). Th^nard (Traits de Chimie, 6th ed. iv. 281), recommends as an
economical mode of preparing brucme, to treat the bark with boiling water, add oxalic
add to the aqueous decoction, concentrate by evaporation, and puriiy the oxalate of
brucine with cold alcohol, as above.

2. Frwn the seeds of Strvchn4>s nux vomica, fc. — Q^e mother-liquors obtained in
the peparation of sttychnine from these seeds (see Stbtchnine), contain brucine,
which may be obtained from them by concentrating to the consistence of syrup, and
slightly supersaturating with dilute sulphuric acid. The mixture, if left to itself for
a few days, deposits crystals of sulphate of brucine, which are to be pressed, redis-
solved in boiling water, and decolorised by animal charcoaL The brucine is then
separated by ammonia.

Properties. — ^Brudne crystallises by slow evaporation from its solution in hydrated
alcohol, in oblique rhsmboidal prisms, often rather laige, and sometimes agglomerated
in beads like mushrooms, ^y rapid crystallisation fix>m boiling water, nacreous
laminated masses are obtained, having the aspect of boric acid. The crystals contain
4 at water of crystallisation (» 15*45 per cent) ; they efiloresoe quickly in diy air,

682 BRUCINE.

and melt in thoir water of oystallisation at a little above 100^ C. They diaaolve in
850 pta. of cold« and 500 pts. of boiling water; they are yery soluble in idcobol, spar-
ingly in essential oils, insoluble in ether and in fiit oils. The alcoholic solution turns
the plane of polarisation to the left; specifie rotatoiy power » —61° 2T. Acids
diminish the rotatory power.

Brucine is poisonous, and acts on the animal economy like strychnine^ bat widi
much less energy.

Jkcompantions. — 1. Strong nitric acid colours brucine deep red, forming a peeoHar
nitro-compoimd ^cacotheline), and eTolving nitrite of methyl, together with nitric
oxide and carbonic anhydride, this last not being a direct product of l^e reacdon, bat
resulting from the decomposition of oxalic add prerioualy formed. (S tracker, Ann.
Ch. Pharm. xd 76^

C"H»'N«0* + 5HN0« - C»H«NH)» + CH».NO« + C*HK)« + 2N0 + 2WO

Cacotheline. Nitrite of Oxalie

methyl. add.

The addition of protochloride of tin to the mixture changes the red cbloor to a fino
▼iolet. This, together with the red colour first produora, is quite characteristic of
brucine, and serves to distinguish it from other alkaloids. — 2. otzong stdpMuHe add
imparts to brucine, first a rose, then a yellow, and then a yeUowiah-green eoLoar. —
8. JBrucine boiled with peroxide of lead and excess of snJbhuiic add, fnms a brown or
red mass. This character further distinguishes brndne from strychnine, whif^ when
treated with sulphuric add and peroxide of lead, assumes a blue colour, i**"gi^g
through violet and red to yellow. — 4. Brudne distilled with suljthuric add and pet"
oxide of man^anetef gives off inflammable vapours and a liquid (probably hydrate of
methyl), which bums with a blue flame; the same liquid is produced on treating
brudne with mercuric oxide, or with sulphuric add and chromate of potassium, car-
bonic and fbrmic adds being likewise evolved in the latter case. — 5. Chlorine does
not produce immediate turbidity in a solution of brudne, but colours it yellow, and
afbeiwards red ; this last colour disappears after a while, the liquid at the same time
depodting yellow uncryvtallisable flakes. — 6. Brondne dissolved in alcohol, qmekly
attacks brucine, colouring it violet. With a weak solution of bromine and sulphate of
brudne, a resinous matter is formed, together with bromobrudne. — 7. Iodine forms
with brucine two peculiar compounds. Iodide of ethyl converts it into hydriodaU
of ethylbrudne.

Combinations, — ^The salts of bbuoinb have a bitter taste, and are for tlie most part
ciystallisable. Strong nitric add colours them red. They are decomposed, not only
by mineral alkalis, but alsa by morphine and strychnine, which predpitate the
brucine. When diluted with water and mixed with a slight excess of tartaric add,
they are not precipitated by acid carbonates of alkaU-metala.

AcBTATB OF Bbvcime is Very soluble and unciystallisable.

Chlosatb of Bbucinb. — Transparent rhombs. Decomposes suddenly when stnmgly
heated.

Htdbochlobatb OFBnTTcnra,C"H**N'0*.HCl,or ChiondeofBrudum, C"H*TSK)*.C1
(at 140^ C.) A solution of brucine in dilute hydrochloric add, yields the salt on oool^
in crystalline tufts, moderately soluble in water. The cidoromercurate^ CH'*N'*0*.HCC
2HgCl, is obtained as a arstalline magma on mixing the alcoholic solutions of the two
component salts ; and if the mass be heated with a small quantity of alcohol and strong
hydrochloric add, the liquid on cooling, deposits the double salt in long needles, which
must be washed, first with a larse quantity of water, and then with strong alcohoL

The chloroplatinate, C«H««lTO*.HClPtCl«, is obtained as a predpitate of a fine
yellow colour, by mixing a solution of sulphate of brudne with dichlonde of platinum.

Htdbofeubootakates OF Bbucinb. — Three of these salts are known : a. 4C"H"N*0\
4HCy.2FeCy + 2H'0. Predpitated on mixing a solution of ferrocyanide of potassium
with nitrate of brudne, in shining needles, sparingly soluble in cold, more soluble in hot
water and alcohol ; veiy hyepxMcopic When heated to 100^ G. or boiled with wat-er,
it decomposes, giving off hyobocyanic add, and depodting a blue predpitate. iS. The
alcoholic solutions of brucine azid hydroferrocyanic add form a white amorphous pre-
cipitate soluble in excess of brudne. It is nearly insoluble in water and in alcohol,
has an acid reaction, and is rapidly decomposed by heat, y, A cold solution of brudne
forms with ferricyanide (red prussiate) of potassium, a deep yellow crystidline pred-
pitate, which appears to be more stable than the salt, &c. (Brandes, Ann. Gl
Pharm. lxvi« 266.)

Htdboflvatb of Bbttonb. — A solution of brudne in warm, moderately concen-
trated hydrofluoric add, deposits, on cooling, small colourless prisms, moderately soluble
in water, sparingly in boiling alcohol, nearly insoluble in cold alcohol. Gives off 3*34
ut water at lOO^C.

BRUCINE. 688

HTDBiOD^n OF Bbuozxi. C"H*N«0*.HI + aq.-^Eeetaiigiilar laminsB, or very abort
prisms ; sparingly soluble in cold, more soluble in hot water ; dissolyes in alcohol more
readily than in water. (B e gn aul t.)

loDATB OF Bbttcznb. — A Bolutiou of bmcine in iodic add, not in excess, yields by
evaporation two salts, viz. an acid salt, which crystallises in hard, transparent^ four-
sided prisms, and an opaque silky salt» which appears to contain an excess of base.

loDiDns OF BnucnnL a. (C"H"NW)M'. — Orange-yellow precipitate, obtained by
adding to a cold alcoholic solution of brucine, a quantity of tincture of iodine not suffi-
cient to form the compound fi, (Analysis 33'3 per cent iodine ; calc 32*4 per cent.)

/9b 0*H**NK)*.P.— Produced by triturating brucine with excess of iodine, either in
powder or in alcoholic tincture. Brown powder soluble in hot alcohol. Treated with
a hot dilute add, it gives off iodine and yields a salt of brucine. With nitrate of
silver, it gives a predpitate of iodide of sUver. (}ave by analysis 36-13 per cent C ;
3*69 H, and 4666 I; calc. 35-8 C, 34 H, and 480 L (Pe He tier, Ann. Ch. Phys.
[2]xliiil76.)

KiTBATB OF. Bbxtcinb. CH'WO^.HNO* + 2aq.— A solution of brucine in dilute
nitric add yields this salt in colourless fbur^sidea prisms, bevelled at the summits.
Less soluble in water than nitrate of strychnine.

OxAULTB OF Bbucxnb cT^tallises in long needles, especially when the add is in
excess. Sparingly soluble in absolute alcohoL

Pbbchlobjltb of Bbuczns. — Small prisms, sparingly soluble in cold water, more
soluble in hot water and in alcohol. Gives off 5*4 per cent water at 170^ C., and
explodes at a higher temperature.

PsBioDiiTB of Bbvcinb ctTStallises from an alcoholic solution by evaporation at
30^ or 40^ G. in beautiful colourless needles, which are decomposed by heat with a
slight noise. Moderat^ soluble in water and alcohol ; the solutions turn brown when
exposed to the air. (Bodeker, Ann. Oh. Phaim. IxxL 64. — Langlois, Ann. Oh.
Phys. [3] xxxiv. 278.)

PHOflPBA^TBS OF BBxrooni. a. (0»H*N*0«)«.H*PO*, or (C"EPrN«0«)«.HJ>0*. (at
100^0.) — A solution of brudne in tnbasic phosphoric acid yields the salt, when concen-
trated, in large shortened prisms, having a fEunt yellowish colour, sparingly soluble in
oold water, but dissolving in any proportion in hot water. Neutral to litmus paper. The
crystals contain water, which they lose on ezposnre to the air. At 100^ they i^e in
their water of crystallisation to a resinous mass, from which it is difficult to expel the
last traces of water. — fi. Add Salt. Obtained by using an excess of add. OrystalUses
in large rectangular plates, very soluble and efflorescent — y. Phosphate of Brucine and
Soda 0«H*N«0*.NaH«PO« (at lOQO 0.) Obtained by digestiog brucine with ordinary
phosphate of sodium. Short opaque prisms. (Anderson, PhiL Mag. [3] Trriii. 163.)

PicBOTOXATB OF Bbttcins crystaQises from a boiling solution in white, silky, flexible
needles.

SmJPRJLTE OF Bbtjcine.— -The normal salty (C"H?«N'0*)«.H«S0*+7aq. is obtained
by saturating brucine with dilute sulphydric add. Long needles, very soluble in
water, sparingly in alcohol ; gives off its water at 130^ 0. An acid sulphate is ob-
tained by crystallising the normal salt with sulphuric acid, and removing the excess
of add by washing with ether. — Double sulphates. On adding brudne to a solution of
sulphate of copper or iron, part only of the metallic base is predpitated.

SULPHOCTAKA.TB OF Bbucinb. U"ll'*N'O^HCyS. — Obtained by saturating an alco-
holic solution of brudne with a moderately concentrated solution of sulphocyanic add.
Colouriess scales, anhydrous, soluble in water, infdsible at 100^ G.

Tabtbatbs of Bbucinb. o. Normal tartrates, (C"H«*NK)«)*.C*H*0* + 6 J aq.
Ssq. and 14 aq. — Obtained in limpid well-defined crystals by dissolving 2 at. brudne
in a hot aqueous solution of 1 at tartaric acid. Very soluble in hot, sparingly in cold
water. — a. The tartrate (dextro-rotatory) is deposited immediately in limpid laminae,
containing 8 at. water, 7} at of which are given off at 100° 0., and the remainder at
160^ (in all 13*22 per cent ; by calculation 13*18 per cent) Orystallised from 95 per
cent alcohol, the same salt contains only 5| at water, or 11 at water to 2 at of the
salt, 5 of which are given off at 100° 0., and the remainder at 150° (in all 10 per cent ;
by calculation 9*5 per cent) The antitartrate (lavo-rotatory) always contains 14H'0,
whether crystallised from water or from strong alcohol. It foresees quickly in sum-
mer ; gives off 20*66 per cent water at 100°, and 1 per cent more at 150° (in all 21
per cent ■■ 14 at.)

0. Acid tartrates. C**H■WO^C*H•0• + 5 aq.— Obtained by mixing bmcine and
tartaric add in equal numbers of atoms. The tartrate precipitates immediately
and completely, as a granular crystalline powder. It is always anhydrous, whether
crystallised from water or from dcohoL Begins to decompose at about 200° 0. The

684 BEUCINE — BRTONIN.

mUUmriraie anfains 6 at. vater (ealc 15*7 per cent ; expi 14'5 per cent.) : gires off
13-3 per ent. (4 Jat.)at 100^, tlie rest at 150^. Veiy soluble in liot» ^wriii^^ in ecdd
water. Effloreseea easilj in diy air. (Pastenr, Ann. Ch. Phjra. [3] xxxnii. 472.)

TmoscLFHATii or Htkmciphits or BarcDni (C'^**NH>^)'.H^SK>* + 5aq. (air-
dried), is fonned when a solution of bmcine, mixed with alcohol and salphide of am-
moninni, is exposed fiir some time to the air. It crystallises in prismatie needlea,
which disBc^Te in 105 pts. of eold water, and gire off 1 at. water whem dried orer oil
of ritzioL (How, £d. N. PhiL J. [new ser.] toL xeriii).

SttbgUttUion-denvaUvn of Brueine,

BnoMOBBrcnn, C^'WBrS'O*. — When a eolation of bromine in dilute alcohol is
added to an aqneons solution of sulphate of bracine, a resinons substance immediately
forms : and if the addition of the bromine be continued till two-thirds of the bmcine
is conrerted into this substance, the decanted solution then precipitated bj ammonia^
the precipitate dissolred in reiy weak alcohol, and boiling water containing a little
alcohol poured bj small portions into the liquid, and afterwards a little pure water,
also boiling, a slight turbidity soon appears; and on leaving the solution to oool,
bromobrucine is deposited in small needles, haying a slight brown colour. It gare bj
analysis 17*5 per cent bromine (calc 16*9 per cent) It is not coloured red by strong
nitric acid. (Lauren t» Ann. Ch. Phys. [3J xxir. 314.)

ETSixsKUcns. C"li"((7H»)NK)*.— The kydriodate of this bsse is obtained by
treating a cooled alcoholic solution of biucine with excess of iodide of ethyl, in crystals
containing 2[C"fl"(C^*)N*0*.HI] + aq. insoluble in water, but readily soluble in
hot alcohoL Potash does not separate the base from this salt ; but on treating the
solution with recently precipitated oxide of silTer, ethylbradne [? hydrate of ethyl*
biucium, c;"H^U"ll*)N*0*iLO, analogous to hydrate of ammoniuml is obtained.
This base dissolves readily in water, alcohol, and ether, bat cannot be obtained in the
solid state. The solution has a sticaig alkaline reaction, precipitates feme oxide, sine-
oxide, and alumina, rediasolring the two latter in excesai It decomposes ammcmia-
salts, and abeorbs csibonic add from the air. With nitric arid, it gives the same red
colour as brudne. It neutralises arids completely. The nitrate and hydrochlorat^*
crystallise, their solutions however becoming ccdoured during evaporation. The hydro-
chlorate forms with dichloride of platinum a crystalline double sal^ containing
C»H»(C«fl»)NH)*.H(nj>ta«. (Gunniuft J. pr. Chem. hcviL 46.)

■KVdTBa Nemalite. LaneatteriU. Native Ma^neda. — ^BI^KO, the maniesium
being sometimes partly replaced by iron. Crystallises in rhombohedral forms. Primary
form R s 82^ 15', generally forming the combinations oR . oo R. Cleavage very easy
parallel to the base. It is usually foliated or massive ; also iibroas, the fibres being
separable and elsstic. Hardness * 1*5. Specific gravi^ 2*35 (Hardin ger). White
inclining to grey, blue or green, with pesriy lustre. Streak white. Trani^iarent in
various degrees, sometimes translucent on the edges only. Sectile. Flexible in thin
laminae. Gives off water when heated, but does not fose. Dissolves in acids without
efflorescence. It accompanies other magnesian minerals in serpentine, in Unst, one
of the Shetland isles, where it is sometimes found in regular crystals; at ^schminsk
in the Ural ; at Goujat in France ; at Hoboken New Jersey ; and in tiie State of New
York. (Dana, iL 133.)

The name Brncite is also used as a eynonyme of C^HOimsoDiTB {q. c.)

BKWO&ZC ACm. A substance obtained bv Runge from coal-tar mq^htha
(Pogg. Ann. xxL 65, 315 ; xxxiL 308). When the alkaline liquid obtained by treat-
ing coal-tar naphtha with milk of lime, is mixed with an acid, a mixture of phenic or
carbolic acid, rosolic acid and bmnolic acid separates out; and on distilling this
mixture with water, the phenic acid passes over, leaving a brown pitchy residue,
containing rosolic and bronolic acid. When this mixture is dissolved in a nnall quan-
tity of alcohol, and milk of lime added, a rose-colom«d solution is formed, contaming
rosolate of calcium, while brunolate of calcium separates as a brown precipitate, which
when decomposed by hydrochloric acid, yields bronolic acid in brown flakes. It ap-
pears to combine with bases, but neither the acid itself nor any of its salts have yet
been obtained in a definite state.

mtUMIi W M f ^il'B WW« A green pigment consisting of oxychloride of copper,
Cu'ClH)' B 2CuCL3CuK), prepared by moistening copper tnmings with hydrochloric
acid or solution of sal-ammoniac, and leaving them in contact with the air. The oxy-
diloride then forms on the surface, and is washed off with water, and dried at a gentle
heat (See Copfbr.)

roiBnr. One of the constituents of the resin of arbol-a-brea (p. 354).
VTOMIMm The bitter principle of the root of the red-berried bryony {Bryonia
dknea). It may be obtained by treating the root with boiling water, preciiMtating the
Altered liquid with subacetate of lead, decomposing the precipitate with mdphuretted

BUBULIN - BUCKWHEAT.

685

bTcbogeD, cfyaporating the filtered liquid, and exbausting the residue with alcohol
(Brandes and Firnhaber, Brandes' Ardi. Pharm. iii 366). It is a yellowish-white
maas* sometimes red or brownish ; tastes sweetish at first, then styptic and yeiy bitter.
Soluble in water and alcohol, insoluble in ether. Snlphuiie add dLssolyes it^ forming
a bine liquid, which changes to green. It is not altered by alkalis. The aqueous
solution forma white precipitates with nitrate of silver, mercurous nitrate, and subacetato
of lead. Biyonin acts as a drastic puzgatiTe, and in large doses is poisonpus. (Gerh.
Trait*, ir. 274.)

According to Walz (Chem. CSentralb. 1859, p. 5), the alcoholic extract of bryony
root contains two bitter substances, bryonin and bryonitin, which maybe sepa*
rated by treating the aqueous infusion of the alcoholic extract with subacetate of lead,
which precipitates the greater part of the bryonitin, leaving biyonin in solution.
Bryonin^when freed from adhering resin by treatment with absolute ether, is a white
or slightly coloured granular substance, transparent in thin layers, and according to
Walz, contains C^H^O*' ; but the simpler formula, C^HH)', agrees well enough with
the results of the analysis. It appears to be a glucoside, and is resolved by boiling
with dilute sulphuric acid, into glucose, and two amorphous bodies, viz. bryoretin,
soluble in ether, and hydrobryoretin, insoluble in ether, but soluble in alcohol:

Bryonia. Brjoretin. Hydro- Olucoie.

bryoretin.

Bryonitin forms a white crystalline mass, soluble in water and ether, insoluble in
aleohoL Walz regards the biyonin of Brandes and Eimhaber as an impure substance.

See the last article,
(from $oAst ox). The name of a peculiar substance, said by Morin
to exist in cow-dung, and to be copiously precipitated by metallic salts, tincture of
galls, and alum, and therefore to be active in we application of cow-dung to calico-
printing.

auCHO&ZXTB. A silicate of aluminium, vaiying in composition between
Al^O'.SiO' and 2Al«0>.3SiO*, and probably nothing but fibrous disthene mixed with
qoartz. (See Bisthbnb and Sillimaxitb.)

See EpmoTB.
See Bhamnus.

iT- Polygonum faaopyrum,oxidP,*tartaricum. — A plant indigenous

in Asia, but much cultivated in the Norui of Europe, where the flour is used for food.
The dry plant yields on the average, 43 per cent by weight of grain, and 67 straw.

The seed of buckwheat contains on the average :

Air dried. Anhydroai.

Kitrogenous matter ....

Starch, &c

Woody fibre, &c ...

Ash . • . • . . ,

Water

Pierre (Compt. rend. xlvi. 203) found in 100 pts. of buckwheat-seed, 2*1 pts.
nitrogen, 0*5 phosphoric anhydride, and 3*2 fat ; in 100 pts. of commercial buckwheat
flour: 1'3 pts. nitrogen; in 100 pts. of the coarse yellow flour: 6*6 nitro^n, 2*4 phos-
phoric anhydride, and 7*2 fat; in the bran, 2'4 nitrogen, 1*2 phosphoric anhydride,
and 4*8 fat. Mulder found in 100 pts. of buckwheat flour 7*5 pts. nitrogenous con-
stituents, and the same in the bran.

8*6

100

61*9

60-6

231

26*9

2-2

2-5

14*2

.-.

Composition of the Ash of the Grain and Straw of Buohohfat

FoUfh

Grain.

Straw.

15*0

lO-S

817

Sin

89*6

40-5

98-9

Soda . .

SOI

S4-0

...

Lim« • . • 1

6-7

11*5

n-o

167

14-0

\*%

11-6

14-1

18-6

Magncflia •

10-4

18-5

40-8

I»

8*9

1-4

4-7

4-9

Ferric oxide .

1*0

0-6

•_

...

Solphuric anhydrlda

«•«

ft-4

6-8

4-7

S-8

9-7

8-6

Silicic »

10 6

4-4

8-6

4-1

4-9

4-8

6*9

Phosphoric „

80-1

13*5

9-0

10*8

9*6

8-9

109

10-0

Chlorlda of pMMilaia <

7-4

S6-9

0*8

8*1

9-7

Clilorido of sodium

1-0

4«

8-9

8*4

Cu-bonlc anhf drldo

SO-4

161

971

90-0

98 1

Alumina

1-9

0-8

„«

mm»

^m.

•■_

Maogiolc oxide . •

•~

8*2

—

■"•

686 BUCKWHEAT — BUTEA GUM.

1. Analysed by Bi eh on (Ann. Ch. Pharm. L 419). 2, 3. By Sprengel (J. taehn.
Chem. Ti 402 ; jl 350). 4^9. By Wolff (J. pr. Chem. HL 65). 4. Stimv of bark-
wheat grown in nnmanured soil; 6, on soil manured with chloride of aodinm; 6, writh
nitrate of potassium ; 7, with potashes ; 8, with sulphate of magnaahim ; 9, with limeu

Sprengel fonnd in the air^wed straw, 3*20 per cenl ash.

VoUmring Matters of Buckwheat. — The leares contain a yellow eoloaring-matter,
first observed by Nachtigal (Jahresber. d. Chem. 1849, p. 718), further examined hf
Sehun ek (Chem. Qaz. 1868, Jan. 18 ; Jahresber. 1857, p. 489). According to SchuiK^
its composition may be most simply eii|«es8ed by tiie formula, CHK)*, and it is pro-
bably identical with rutin (q. v.\ and with Moldenhanei's ilixantkitL It arygtaluaem
in yellow needles, dissolyes sparingly in cold water, mom readily in boiling water,
more still in aloohoL Alkalis dissolve it» forming a deep yellow solution, from wbieh
it is precipitated by acids ; i^ however, the solution be exposed to the air, the ooloor-
ing matter is transformed into an amorphous substance, easily soluble in water, and do
longer predpitable by adds. Hydrochloric and sulphuric acids change the yellow
colour dT the crystalline substance to deep orange : but water restores it. DUute sul-
phuric add does not decompose it, even at boiling heat; nitric acid converta it into
oxalic acid. With oxide of lead, it forms a bright yellow compound, like chrotDate of
lead, and communicates a bright yellow colour to cotton stafEs mordanted with acetate
of alumina. The presence of foreign matters in the crude extract of budnrheat straw,
renders the colour somewhat impure. According to Nachtigal, 5 pts. of buckwheat
straw contain as much colouring matter as 1 pt. of quodtron. According to Sdiunck,
1 000 pts. of the fresh leaves contain rather more than 1 pt of pure colouring matter.

Budcwheat straw has been said to yidd indigo by fermentation ; a statement which,
however, is not confirmed by the observation of Schunek (Handw. d. Chem. i* Anfl.
ii [2] 651. Ur^s Dietianary of Arts, Manufactures, and Mines, ii 467.)

BUUUJtUMAMO'A BHHW. A fossil resin, occurring in an auriferous aDuriom
near Bucurumanga in New Granada. It is light yellow, transparent, somewhat heavier
than water; becomes strongly dectric by friction ; is insoluble in alcohol ; swells up in
ether and becomes opaque. It mdta when heated, and bums in the air without
residue. It resembles amber in outward appearance, but does not yidd sucdnie add
by dry distillation. It contains 82'7 per cent carbon, 10*8 hydrogen, and 6*6 oaTgen.
(Boussingault^ Ann. Ch. Phya, [3] vi 607.)

A substance obtained by Bodmer, fiopi the bark of Busna AesMsuira.

ITOVa. A cellular flinty quartz rock.

:V &BAW. The leaves of JHosma erenata, a rutaceous plant growing
at the Cape of €Kx>d Hope. O ass i ncour t (Buchn. B^pert Fharm. xxvi. 328) fonnd in
1000 pts. of them, besides gum, resin, &c, 6*6 pts. of a volatile oil, having a gdd-yellow
colour, a sharp irritating taste and odour, lighter than water, and somewhat soluble
therein. Brandes (Arch. d. N. Apoth. Ver. xxii. 229) found malic and oxalic adds
in the leaves, besides albumin, gum, resins, &c. ; and in 1000 pts. 88 pts. volatile oil,
and 40 pts. of a yellowish-brown bitter substance, soluble in water, which he called dios-
ffun. Landerer (Buchner^s Rupert Ixxxiv. 63) found in the alcoholic tincture of
bukku leaves, a czystalline bitter depodt^ iriiich, however, was insoluble in water.

smULTITB. A hydrated carbonate of zinc, copper, and caldnm, occurring in
verdigris-green, radis^tea, adcalar crystals, or plumose aggregations, of specific gravity
3'32, at Chessy and Frammont in France, and at Volterra and Temperino in Tuscany
(Dilesse, Ann. Ch. Pbys. [3] xviii. 478). It is very yaiiable in composition, and is
probably a mixture of several minerals.

See ANiXTSD, Yoluiirbio (p. 266).

WITCM or MMMSMm Paix ds Bourgogne, Fix alba, Poix hfanchr,
is the white pitch obtained from pine-wood. The resin of Pinus picea purified by
repeated boiling with water, is also called Burgundy pitch, (See P^kb-bbsons and
PnccH.)

MUWUUBLML OUMMXFBBA* Gommart. — ^A terebinthaceous tree growing in
the Antilles. It yields a dry white resin having a oystalline fracture, and an odour
of turpentine, also like that of elemi. It is bat slightly fuuble, but difiuses itself
through boiling water in small tenacious granules. The resin distilled with water
yidds 47 per cent of a coloured volatile oil (Chmmart-oil, Essence de gommart\
which, when purified by standing in contact with potash, then with potassium, and
rectification, has the same odour, compodtion, and vi^ur-density as oil of turpentine,
and forms with hydrochloric acid, two compounds, one of which is crystalline and ood-
tists of C»H".2HCL (H. Deville, Ann. Ch. Phys. [3] xivii 90.)

Native sUicate of manganese. See RHODOMm.
Bengal Kino. — The juice of ButeafrondosOf RoKb., often aent into

BUTIC ACID— BUTTER. 687

the maricet instead of genniiie kino. It forms black>brown, slightly lustrous, brittle
hunpsy has an astringent taste, and yields pyrocatechin by dry dStillation.

BUVIO JLOXBm A solid fatty acid, which Heintz obtained (Pogg. Ann. xc.
137), though not pure, by partially precipitating an alcoholic solution of the solid fatty
acidsof butter witn acetate of magnesium, this add then forming the less soluble com-
pound. HeintE is of opinion that in the pure state it would have the composition of
arachidic acid G»H^*. (See p. 353.)

JlUTTJnU The fatty non-azotised constituent of milk. It is suspended in the milk
in minute globules, and rises to the surface, when the milk is left at rest, in the form of
cream, together with a certain quantity of casein and the other constituents of the milk.
Butter is obtained from cream by agitation or chumina, which causes the fat-globules
to unite in larger masses and separate completely from the wateiy liquid, called
butter-milJk. Butter thus obtained and in the state in which it is commonly used, consists
of } pure fat or real butter and { of butter-milk, from which it may be separated by
melting it in a tall vessel at about 60^ C, decanting the clear fiit which floats at the
top^ and washing with water at 40^ C. Ordinary butter from cow's milk, is com-
posed, according to GheTreul, of stearin, maigarin, and olein, with small quantities of
bntyrin, caproin, and caprin, to which its odour is due. According to Heintz, it con-
tains olein, a huge quantity of palmitin, and a smaU quantity of stearin, together
with TCiy small quantities of glycerides, yielding by saponification, myristic acid and
butic acid, C»H»«0« (vid. 3up.)

Butter dissolves in 28 pts. of boiling alcohol of specific grayity 0*82. It is Teiy
apt to turn randd, a change which consists in the separation of the fatty acids from
the glycerin, and may be prevented to a certain extent by salting or by melting it, so
as to separate the foreign matters which induce the decomposition.

" At ConstiMitinople, the butter brought from the Crimea and the Kirban, is kept
sweet by meltinjg it while £resh over a very slow fire, and removing the scum as it
rises. By melting butter in this manner, and then salting it, it may be kept ^ood
and fine-tasted for two years ; moreover, this melting, if carefidly done, injures neither
the taste nor colour. Th^nard too recommends the same method. He directs the
the melting to be done on a water-bath, or at a heat not exceeding 140^ Fahr. ; and
to be continued till all the caseous matter has subsided to the bottom, and the butter
is transparent. It is then to be decanted, or strained through a doth, and cooled in
a mixture of poimded ice and salt, or at least in cold spring water, othewise it Mrill
become lumpy by crystallising, and likewise not resist the action of the air so welL
Kept in a dose vessel, and in a cool place, it will thus remain six months or more,
nearly as good as at first, particularly after the top is taken off. If beaten up with
one-sixth of its weight of Uie cheesynnatter when used, it will in some degree resemble
fresh butter in appearance. The taste of randd butter, he adds, may be much cor-
rected by melting and cooling in this manner.

"Another mode of curing butter, is as follows: Take one part of sugar, one of nitre,
and two of the beet Spanish great salt, and rub them together into a fine powder.
This composition is to be mixed thoroughly with the butter, as soon as it is com-
pletely fi'eed frt>m the milk, in the proportion of one ounce to sixteen ; and the butter
thus prepared is to be pressed tight into the vessel prepared for it, so as to leave no
vacuities. This butter does not taste well, till it has stood at least a fortnight : it then
has a rich marrow fiavour, that no butter ever acquires ; and with proper care may be
kept for years in this climate, or carried to the East Indies, if packed so as not to melt

** At Kebba, in the interior of Africa, Mungo Park informs us, there is a tree much
resemblinff the American oak, producing a nut in appeiurance somewhat like an olive.
The kemd of this nut, by boiHng in water, affords a kind of butter, which is whiter,
firmer, and of a richer fiavour than any he ever tasted made firom cows* milk, and will
keep without salt the whole year. The natives call it shea touhu, or tree butter.
Lai^ quantities of it are made eveiv season." U.

Butter is often largely adulterated with water and salt, which are introduced while
the butter is in the melted state and incorporated by stirring till the whole is cold.
The proportion of water may be determined very nearly by melting a portion of the
butter in a narrow glass vessel, such as a common ounce phial, and leaving it to stand
in a warm place till the water settles to the bottom. The quantity of the water should
not exceed 1 per cent The amount of salt is determined by calcmation, any Quantity
beyond 6 per cent may be regarded as adulteration. Butter is also frequenUy adul-
terated with lard, in places where that kind of fat is cheap. (For the preparation of
butter, see Ur^s Dictionary of ArU^ Manufactures^ and Mines, also Muspratfs Che"
mistry, i. 897.)

BUmnt OV AM TlMOMTff TXV, &c. Old names for anhydrous metallio
chlorides having a buttery consistence.

688 BUTYLACTIC, BUTYRACETIC ACID.

BUn& and deiiTatlTas. Syn. Tbtbtl and deriyaLtires.

VUnrJOLCTXiC JLCm, Oxybutyric acid. C*H»0» « (C«H«0)*'.H«.0*. (A.
Wurtz, Ann. Ch. Phann. cvii. 197.) — ^This acid has hitherto been obtained onlj by th«
oxidation of amyl-glvcol (p. 208) ; but it might doubtless be prodnced also by the
oxidation of butyl-glycol, as well as by other processes. It is prepared by gently
heating 14 pts. of amyl'^lyool with 30 pts. nitric add (HNO') and 42 pta. vster, snd
CTaporating oyer quick hme ; it then remains in the form of a sympy uquid..

Butylactic acid bears to butyric acid the same rehition that lactic add bears to pro-
pionic acid, and in consequence of this relation, it is regarded as dibasic (see Lacnc
Acm), although all the salts yet obtained from it contain but one atom of metal in
place of hydrogen. The bariumrsalt, C^H'BaO*, is uncrystallisable, dissolTes in all
proportions, and with moderate &cility, in dilute alcohol, but is insoluble in abeolute
alcohol ; ether precipitates it ficom the alcoholic solution. The caleiKmsali, C^H*CaO*
(dried at 120^ C), separates firom the aqueous solution by spontaneous eTapozation in
warty crystals, which dissolve readily in water and in absolute alcohol, but are in-
soluble in ether. The tnnc-salt, OH'ZnO' + aq., crystallises in shining Irt^mtwao^ which
dissolve in 160 pts. of wat«r at 15^ C, but are insoluble in absolute akohoL Th«
crystals are permanent in the air, but give off 11 per cent (2 at.) water at 100^ C.

BVnSACarzC ACZB. Pseudo-acetic AM, C^*0* or C'H'O'.C^EK)* — An
acid first obtained by Nollner in 1841 (Ann. Ch. Pharm. xxxriiL 229), as a pcodnct
of the fermentetion of a mother-liquor firom the preparation of tartaric acid rtnwtyJti^wg
a considerable quantity of tartrate of calcium, or by converting crude tartar into im-
pure tartrate of calcium, and fermenting the product Nollner designated this &eid
pseudo-acetic acidf from its resemblance to acetic add. Berselius regarded it as a
mixture of acetic and butyric acids. Nickl&s, however (Compt rend. -irrYiif 419),
showed that, although this acid i& easily resolved into acetic and butyric adds, it is,
nevertheless a distmct acid, and gave it the name butyracetic acid. Dumas^
Malaguti, and Leblanc (Compt rend. xxv. 781), showed that it is identical in
composition and boiling point with propionic acid, which it also resembles in its other
physical properties, and moreover steted that its salts are identical with the pro-
pionates m composition and crystalline form. Nickl^ on the other hand, maintained
that the salts differ in certain respects firom the corresponding propionatesL Lastly,
the acid has been examined by Llmpricht and v. Uslar (Ann. Ch. Pharm. xdr.
321), who have shown that butyracetate of barium yields, by dry distillation, propylal,

Cropione, and propylene (tritylene), in which respect it exactly resembles the propionate;
ut that, on the otiier hand, butyracetic add separates spontaneously or by oistillation,
into acetic and butyric adds, which is not the case with propionic acid. On the whole,
therefore, butyracetic acid must be regarded as a distinct add. It appears to be pro-
duced only by the fermentation of tartrate of caldum ; acid tartrate of potassium,
whether crude or purified, yields by fermentation nothing but acetic add. According
to later experiments of NickUs (J. Pharm. [3] xxxiiL 351), it is likewise obtained
by pouring a mixed solution of equivalent qualities of an acetate and a butyrato into
dilute sulphuric acid.

Butyracetic acid resembles propionic add in most of its properties. It mixes in all
proportions with water, and is separated therefirom unaltered by chloride of caldum, a
property which distinguishes it fiom a mere mixture of butyric and acetic acids.
According to Dumas, it boils constantly at 140° C. ; but, according to Limpricht and
V. Uslar, it be^ns to boil at 120°, at which temperature nearly pure acetic acid paaives
over, and the boiling point gradually rises to 160°, when butyric acid distils over, the
boiling point not remaining stetionaiy for any time at 140°. It does not yield dther a
definite anhydride or a definite ether, but in both cases a mixture of acetate and
butyrate.

Butyracetate of Barium, CH'BaO^ + ^aq., resembles the propionate in composition
and properties ; but on decomposing it with sulphate of copper, the add which is set
firee separates into butyric and acetic adds (Nickl^s). The calcium-salt, CHK^aO*.
forms silkr needles, or, according to Nickl^, regular octahedrons, which effloresce in
the air. The copper-salt ciystal&ses in dark blue-green tables, which give off part of
their water of crystallisation at 100° C. It rotetes on water, dissolves sparingly in
water, more easily in alcohol.

The neutral lead-salt crysteUises fix>m a very concentrated solution at low tempera-
tures in cauliflower-like masses. It melts when heated, giving off part of its add,
and deliquesces in moist air. A concentrated solution, to which chloride of barium is
added as long as the predpitate first formed disappears on agitation, yields by slow
evaporation, a double salt which ciystallises in square prisms containing barium and
lead, and likewise chlorine. The oasic lead-salt is formed by boiling the preceding
with oxide of lead. It crystallises from a moderately concentrated solution at a little
above 0° C, in octahedrons which contain 42 per cent water, undergo aqueous fusioB

BUTYRAL. 689

below 19^, and dissolTe readily in alcohol From a very concentrated eolation or from
fnsioii, itciTstalliees in tables; at reiy low temperatures, however, in spherical seg-
ment8» which, when gently heated, split from the centre outwards with a slight noise.
By Buxing the boiling solution of the lead-salt with a little ammonia, a ciystalliiie
powder is precipitated. (NoUner.)

The mercurout salt crystallises in satiny scales, which are reddened by light The
potassium-^ali crystallises in yeiy deliquescent thin tables. The sUver-salt separates
on cooling from a boiling solution of the ammonium-salt, mixed with a boiling solution
of nitrate of silver, in shining needles resembling acetate of silver and sparingly
solnble in water. The aodiumsalt crystallises from a somewhat dilute solution in
deliquescent octahedrons ; from a more concentrated solution, as a white tallowy amor-
phous mass, or as a radio-crystalline mass. The tino-^alt is soluble in water, but de-
composes by boiling.

ana BUTl BftTillBmiia, C*H*0. — Two compounds are known
which have the composition of the term in the butyric series corresponding to that of
aldehyde in the acetic series ; they are not, however, identical.

Butyral was obtained by Chancel (Ann. Gh. Ph^ [3] xii 416), among the pro-
ducts of the destructive distillation of butyrate of calcium. The crude product of this
operation is a mixture of several substances, of which butyral, boiling at 96^ C. is the
most volatile, and can be separated from the others by finuitional distillation.

Puzo butyral is a colourless, veiy mobile liquid, with a burning taste, and a sharp
and penetrating odour. Its densil^ at 22^ C. is 0*821, and it boils at 95^. It dissolves
a small quanti^ of water. It is slightly soluble in water, and soluble in all proportions
in alcohol, ether, and wood-spirit It rapidly absorbs oxyeen from the atmosphere,
and is converted into butyric acid. It is oxidised by solid (mromic acid with a slight
explosion. It is very inflammable and bums with a brilliant flame. Heated with
water and oxide of sdver, it reduces part of the oxide to the state of metallic silver,
butyrate of silver remaining in solution. On heating it with sulphuric acid, sulphurous
add is liberated, and a small quantity of butyric acid remains in solution. By dilate
nitric acid, it is converted into nitropropionic acid. It forms ciystalline compounds
with acid sulphites of alkali-metals, analogous to those which aldehyde forms. By the
action of pentachloride of phosphorus on butyral, hydrochloric acid, oxychloride of
phosphorus, and a peculiar product, C^H'Cl, are formed:

C*H»0 + Pa» - C*TL'C[ + HCl + P0C1«.

This product is a colourless, oily, very mobile liquid, lighter than water, with a sharp
odour and a biting taste. It is insoluble in water, but soluble in alcohol and in ether.
It boils at a litue over 100^ C. ; it is inflammable, and bums with a green-edged
flame. It is probable that the action of pentachloride of phosphorus on butyral is
analogous to its action on aldehyde, and gives rise to the compound CuI'Gl*,
homoh)goas with chloride of ethylidene (p. 107), and that at the moment of its
foimation, this substance is decomposed into hyorochloric acid and the body above
described.

Chlorinated Derivatives of Butyral. — Chlorine acts veiy energetically on
ba^rral, with the formation of definite compounds containing chlorine in the place of
hydrogen.

Manochhrinated Butyral* C^H'CIO. — Produced by passing a current of dry chlorine
through butyral by diffused light. The gas is at first absorb^ with evolution of heat
and pale red coloration ; afterwards the colour disappears and the liquid gives off'toirents
of hydrochloric add gas to the end of the operation. A rapid current of carbonic
anhydride is then pasMd through the liquid heated somewhat below its boiling pointy
and it is then rectified. It is a transparent limpid lic^uid, heavier than water;
boils at 141^ C; has a pungent tear-exciting odour. It is insoluble in water, but
dissolves in alcohol, and its alcoholic solution does not doud nitrate of silver. It does
not form an amide with ammonia.

Dieklorinated Butyral, C^H*C1K). — ^When dry chlorine is passed for three hours
through butyral exposed to sunlight, the action is observed to slacken after some time.
If carbonic anhydride be now passed through the liquid, which is afterwards rectified, a
neutral oil is obtained boiling at 200*^ C.

T^irachlorinated Butyral, C*H^C1*0. — Chlorine is passed for several days through
butyral exposed to bright sunshine, the liquid being ultimatdy heated, and the action
continued as long as hydrochloric acid gas continues to be eiblved. When purified
like the other substances, it forms a thick heavy neutral oil, which boils at a high
temperature, with decomposition.

Butjnddelijde. C^H"0 - C^H'O.H.— This body was obtained by Quckdberger
among the products of the action of oxidising agents on fibrin, albumin, and casein.
Vol. I. y Y

690 BUTYRAMIDE.

For the fall details of the prooees, GhickeLherger^B paper most be referred to (Ann. Ou
Pharm. Iziv. 39). The crude distillate resulting from the action was neutralised with
chalk and distiUed. A neutral distillate was obtained which consisted of the alde-
hydes of the acetic, propionic, butyric, and benzoic series. These were sepaiated by
fractional rectification, the portions between 70^ and 100^ G. which consisted of
butyric aldehyde mixed with a little propionic aldehyde, being collected separately.
Butyric aldehyde is much less soluble in water than propionic aldehyde, and may be
separated from it by agitation with water. To obtaan the bulyraldehyde quite pnrei,
it is agitated with ammonia, with which it forms a crystalline compound. This is
decomposed by the addition of a concentrated solution of ahun, the liquid distilled, and
the distillate rectified over chloride of calcium.

When pure, it is a thin, colourless, transparent oil, which has the ^tecific grsTity
0*80 at 15^ C. It boils at 68*^ to 75^, and has an ethereal, somewhat penetrating odour.
The small quantity in which this substance has been found, has prerented its com-
plete inyestigation ; but almost ail its properties, as £Eff as they hare beoi ezamined,
are identical with those of butyral. It acidifies in the air; an aqneoos solution
mixed with ammonia, and then with nitrate of silver until the alkaline reaction dis-
appears, eiveSjOn the application of heat, a beautiful coating of metallie salver on the
sides of the vesseL It differs from its isomer chiefly in its boiling pointy its deosxty,
and in forming a crystalline oonipound with ammonia, which bu^rnl does noL

BtUyraldehyde-ammonia, NH'.C*H*0 + 5aq. — Butyraldehyde forms with strong
ammonia, a cirstalline mass consisting of small acute rhombic octahedrons; from an
alcoholic solution, the compound crystallises in large rhombic tables. The diy crystals
do not alter in the air, but in the moist state they gradually become Imown. Gently
heated, they melt, and sublime at a few degrees above 100° C; more stron^y heated,
they give off ammonia. Potash does not expel ammonia from them at ordinary tem-
peratures. Aqueous acids or alum separate butyraldehyde. Butyraldehyde-ammonia
IS almost insoluble in water, but soluble in alcohol, and in ether.

Sulphuretted hydrogen passed into a solution of this body, appears to fbnn a eom-
pound homologous with thialdine. When the liquid resulting from this action is
treated with ether, a sulphuretted oil is obtained, which forms with hydrochloric add
a solid crystalline compound. £. A.

BVTTmAMZBB. C^H'NO -t ]^[^* ^^ compound, homologous with

acetamide, is prepared by placing 1 pt of butyric ether, and 6 pts. of strong aqueous
ammonia, in a flask, and fr^uently agitating the mixture until me action is complete,
which generally takes from eight to ten days : the liquid is then evaporated to one-
third, and on cooling the butyramide crystallises out:

C*H'(C«H»)0" + NH« - C*H»NO + C^«0

Butyric ether. Butjramlde. Alcohol.

It crystallises in snow-white, nacreous, transparent tables, which melt at 115^ C. to a
colourless liquid, and volatilise without residue. It has a sweety cooling taste, with
bitter aftertaste. It is readily soluble in water, also in ether and in aJoohoL Its
vapour is inflammable. Passed over red-hot lime, or distilled with anhydrous phos-
phoric acid, it loses water and yields butyronitrile (cyanide of trityl) :

C*H»NO - ffO - C*H«N
Butjrra- Butjrronl-

mide. trile.

Its aqueous solution is decomposed by boiling with fixed alkalis, yielding ammonia and
an alkaline butyrate :

C*H»NO + KHO - C*H'KO« + NH«.

Bv pentachloride of phosphorus, it is converted into cyanide of trityl, os^chloride
of phosphorus, and hydrochloric acid :

C*H"NO + Pa» - C«H^ + POa« + 2HCL

It is decomposed by nitrous acid, with formation of butyric acid, water, and nitrogen:

C*H»NO + HNO» - C*HK)« + H«0 + N«

Butyramide, Nitroui Butyric

acid. acid.

Mercuric Butyramide, C*B?HffNO, is obtained by boiling merenrie oxi4e with so-
lution of butyramide. ^he filtered solution, when concentrateid, deposits the compound
in small nacreous oystals, more lustrous than butyramide, which they otherwise re-
semble. £. A.

BirmZO ACIB. C'H^'O* « ^^'^|o.~Butyric add is a member of the

BUTYRIC ACID. 691

Beries of volatile fktty acids, of the general formula OB>0*. It was discorered hv
Chevreul, wbo obtained it by* saponifying butter mth alkalis. It occurs in nature both
in the firee state, and' in combination vith bases. It is found in perspiration, in the
jniee expressed from human flesh, and from that of animals ; in crude oil of amber;
and in ood-HTer oil. It is found in all liquids containing lactic acid, as a product
of die transformation of this substance. Butyric acid is also contained, together "with
several fatty adds of the same series, in combination with glycerin, in butter from
oows and goat's milk. This compound of butyric acid -wmt glycerin is inodorous,
and it is to its decomposition on standing, by which butyric acid is set free, that
the odour of rancid butter is chiefly due. Butyric acid is a frequent product of the
oxidation of organic substances, as when flbrin is treated with sulphuric acid and
peroxide of manganese, or when oleic acid is oxidised by nitric acid. It has also been
found among the products of the destructiTe distillation of tobacco (Zeise) and of peat
(Sullivan, Jalu^ber. d. Chem. 1858, 280). Lastly, it has been found in several
plants, in certain beetles, 'and in certain mineral waters. (Gm. x. 76 ; xiii. 388 ;
Handw. d. Chem. a [2] 561.)

The most important mode of its formation, and that on which the present methods
used for its preparation are based, depends on the metamorphosis which starch, sugar,
&C. undergo in the presence of substances which act as ferments. Pelouze and G^lis
have found that butyric acid can be obtained from all amylaceous and saccharine
matters, which can be transformed into lactic acid, such as cane-sugar, milk-sugar,
starch, dextrin, &c. These substances exposed in water to a temperature of 25^ to 30^ C.
in contact with old cheese, or some other decaying nitrogenous substance, flrst undergo
the lactic fermentation, and are ultimately converted into butyric acidl This latter
pliase is attended with disengagement of carbonic anhydride and hydrogen :

C«H>K)« - C*HK)* + 2C0« + H«.
Lactic add. Butfrio
acid.

The oriffinal process given by Pelouze and O-ilis, has subsequently been modified by
Bensch, irtiose method is essentially as follows : 6 lbs. of cane-sugar and 4 an os
of tartaric acid are dissolved in 26 lbs. of boiling water, and left to stand for some
days to allow the cane-sugar to pass into grape-sugar. To this solution, about 4 oz.
of decayed cheese, diffused in 8 lbs. of sour skim-milk, together with 3 lbs. of chalk,
are added, and the whole is left in a place the temperature of which is uniform at about
30 — 350 Q, xhe mixture is frequi'ntly stirred, and generally solidifies after ten or
twelve days, to a thick mass of lactate of calcium. If this be allowed to stand under
the same conditions, the evaporated water being renewed, it again becomes liquid, gas
babbles rise, and at the expiration of five to six weeks, wh.*n the disengagement of
gas has ceased, the whole of the lactic acid (and therefore the whole of the sugar), has
passed into butyric acid, which is present as butyrate of caldum. The operation seems
to sneoeed best with large quantities of substance.

The above solution of butyrate of calcium is mixed with on equal bulk of water, and
a solution of eight pounds of crystallised soda is added, with agitation. The solution
filtered off from the carbonate of calcium is evaporated to ten pounds, and decomposed
by the earefol addition of five and a half pounds of sulphuric acid, previously duuted
with an equal weight of water. The greater part of the butyric acid then separates as
an oily layer on the surfiice of the solution of the acid sulphate of sodium, and is re-
moved by means of a tap-fonneL In order to obtain the butyric acid still contained in
the solution of sulphate of sodium, it is distilled, the distillate neutralised with carbonate
of sodium, evaporated, and the acid separated as before by means of sulphuric acid.

The united portions of crude butvric add, which, besides water, always contain
some sulphate of sodium, are mixed with sulphuric add (about one ounce to one
pound) in order to invent the separation of neutral sulphate of sodium, which would
cause convulsive distillation. Tne distillate consisting of aqueous butyric acid is
mixed with fused chloride of caldum, and rectified. At first, dilute add passes over
accompanied by traces of hvdrochloric add ; this afterwards gives place to concentrated
add, which when fractionally distilled, is obtained of a constant boiling point and quite
pure. It is better to use sulphuric than hydrochloric add in the decomposition of
Dutjrrate of ^dum, as the latter causes the mixture to froth up, and it is difficult to
free the butyric acid completely from hydrochloric add.

Bntyxie add may also be prepared by saponifying butter with an alkali, and distilling
the soap with sulphuric acia. But this method is never used for the preparation of
pure butyric add, as its separation from the accompanying soluble fatty aads is very
difficult and troublesome.

Properties. — Butyric acid, when pure, is a colourless, transparent, and very mobile
liquid, having an odour suggestive both of vinegar and of rancid butter. It has a
very sour and burning taste, and attacks the skin like the strongest adds. It boils at

TT 2

692 BUTTRIC ACID.

157^ C. under 760 mm. incMiue (Kopp), and distfli witfaont altenikm. Iti Tapoo*
density Tsriea with the temperature ; afe 261^ C. it vas found to be 37, eomtponding
to 2 Tola. The Tapoor ii milammable» and boina with a bhie lame. The deniitr
of the liquid add is 0*9886 at O^C; 0-9739 at 15<); and 0-9675 at 25». It dota
not fldidify at 20^, bat in a miztoie of solid carbonie acid and ether it OTataDiNi
in i^atea. Bntjric acid is sohible in all proportions in watai; alcohol, and wood-
spirits

JkeomposUumM, — L Botjric acid diasohres in tuUpkurie add without altenttian ia
the cold ; at higher temperatim^ the greater part di^ils off nnehanged.— 2. It ailfo di»-
flolree in nitric acid in the cold; bj prolonged ebollition with nitric wad of Bgtai/t
gravity 1*40, it ia tranaformed into suocinie add :

C*HH>« + 0« = C^*0« + HPO.

Batyric Soocinlc

add. mM.

3. Iodic acid does not act npon batjric acid. — 4. Botyrie add is energeticaSj attacked
bj ch/orine, with formation of hydrochloric add and of dichlorobntjrie acid,
OH'Cl'O*. If the action of the chlorine be coutinaed, the bntjric acid is idtiinatelj
conrerted into tetrachlorobntyric acid, C*K*ClHy. Iodine has scarodj any
action on bntrric add. — 6. By the action of pentacUoride o/pho^korus, chloride of
bntyryl, C^&'OCl, ozychloride of phoephonu, and hydrochloric add are fanned:

c«H"o« + pa» - OH^oa + POOL' + na

Batyrfc Cbloriie of

add. botTiyL

6. With. pmUuulpkide of photpkonu^ it forma thiobntyrie acid (p. 694).

Batjrric add. Tbiobtiijric

add.

BuTTSATB& — Bubrrie add is monobasic^ the bntyrates being represented by the
general formula C^EPMO' « C'H'O.M.0.

When quite dry, they are inodorous; but niien moist, they posseas a strong odoor of
butter. They are mostly soluble in water, and oystaUisable. Many of them rotate
when thrown upon water.

But y rate of Ammonium, C*H'(NH*)0* — A deliquescent salt, which gires
butyronitrile, OH'N, when distilled with anhydrous phosphoric add.

Butyratt <>/^«yM gee Bottbk Etdm (p. 695).
Butyrait of AmyUS

Butyrate of Barium, OK'iSaO*-i-2aq. — Obtained by neutralising hutyne
add with baiyta-water. The filtered solution evaporated in the cold yields long
flattened prisms, which are quite transparent, and contain 2 at water. Th^ mrit
at a temperature below 100^ C, without any loss of weight, to a tran^arent liquid.
The salt dissolves in 2*27 pts. of water at 10°, and rotates on the soi&oe. Wha
butyrate of barium is crystallised from a hot concentrated solution, it contains IH
per cent of water » 1 at water of crystallisation, its formula being C^H'BaO* -t- aq.

Butyrate of Copper. C*H'CuO* + HK).— According to Chevreul, andtoPeloii»
and Gelis, this salt contains 2 at water ; according to li^Bodart, 1 at vater. It
is obtained by the addition of a cupric salt to a solution of butyrate of potaanoffl.
The bluish-green precipitate formed is ciystallised from boiling water, which yields it in
crystals of the monodinic or oblique prismatic system. By prolonged ebullition vith
water, the salt is partially decomposed into subsalt and free butyric add. By distilla-
tion at about 260° C, butyrate of copper is completely decomposed into a liqnid vhieh
]^>pear8 to be pure butyric acid, a gas composed of equal volumes of carbonic oiide
and carburetted hydrogen, and a residue of finely divided metallic oo^^ier mixed with
carbon. When butyrate of copper is rapidly heated to a high temperatore, there is
produced, along with other substances, a white crystalline body, which is cnproes
butyrate. A compound corresponding to Schweinfurt-green (p 16) ii obtains by
mixing a solution of butyrate of copper with solution of arsenious acid. A yello«isb>
green amorphous precipitate forms, which afterwards becomes crystalline, and exhibits
the pure green colour belonging to SchweinAirt-green. It is a double salt of arsenite
and butyrate of copper, C*H'CuO-.2AsCuO«

Butyrate of Calcium. OH'CaO« (at 1400C.).— Obtained like the barimn-wlt
Crystallises in delicate needles ; mdts on being heated in its water of crystallisation,
which it gives off with tolerable facility. The dry salt, on being distilled gites an oily
distillate, consisting principally of butyral and butyrone. This salt rotates vhen
thrown on water. It dissolves m 5*7 pts. of water at 16^ but crystallises oat so cod-

BUTYRIC ACID. 69^

plaCelj when the solution is heated, that the whole becomes solid. On cooling, it again
beoomes liquid.

Butyrate of Calcium and Barium. — The aqueous solution of 2 pts. butyrate of cal-
chim, and 3 pts. butyrate of barium, deposits octahedions of this double sietlt on spon-
taneous eraporation.

Buiyrate of Iron. — ^Iron does not decompose dilute butyric add, but gradually
ozidisea at the expense of a portion of the acid, the oxide combining wiUi the remainder.
A yellowish basic salt which separates, appears to be soluble in a large quantity of
water.

ButyratB of Ethyl, See Bdttbio Ethbbs (p. 695).

Butyra tes of Lead. — The neutral salt, C^HTbO', is obtained in fine silky needles
by abandoning the solution of lead-oxide in butyric acid to spontaneous evaporation over
oil of vitrioL The same salt is precipitated by but^c acid from a solation of neutral
acetate of lead, as a colourless very heavy oil, which solidifies after some time only.
Bane-salt^ OH'PbO'JPb'O. Alkahne butynites give a copious white precipitate with
solutions of subacetate of lead. When a mixture of acetic and butync acids is satu-
rated with lead-oxide, rose eoloured crystals of basic butyrate of lead are formed.
These are decomposed by the carbonic acid of the air, but are held in solution by the
acetate which adneres to them.

Butyrate of Maanesium. 2(d*H'])lgO*) + 6a^. — ^Beautiftil white laminae, like
oystalliBed boric adcL The water of crystallisation is easily expelled.

Mereurous Butyrate. — ^White shining scales, like mercurous acetate.

Butyrate of Methyl. See Buttbxo Ethbbs (p. 696).

Butyrate of Potaesium. C'H'KO*. — Carbonate of potassium is neutralised
with aqueous butyric acid, and the solution evaporated. CrystttUises in indistinct
cauliflower-like groups. Very deliquescent; dissolves in 0*8 of water at 16° C. Bo-
tates on water. There appears to be an acid butyrate of potassium. When butyrate
of potassium is distilled with an equal ^uantity^ of aisemons anhydride, there is ob-
tained, besides secondary products, an oily liquid blackened by reduced arsenic, and
smelling like alkarsiTi ; it is either alkarsin or the term corresponding to it in the
butyric series (p. 412.)

Butyrate of Sodium is like the potassium-salt, but less deliquescent

Butyrat0 of Silver. G^H^A^iO*. — Butyrate of potassium mixed with nitrate of
■ihrer forms white shining scales, like acetate of silver. The salt does not deflagrate
when heated, but leaves metallic silver mixed with a little charcoaL

Butyrate of Strontium. C'H'SrO' (dry).— Long flat needles like the barium-
salt; fhsible; soluble in 3 pts. of water.

B utyr a te of Zine. OH'ZnO'. — ^Aqueous butyric acid dissolves carbonate of sine
at ordinary temperatures ; the flltered solution evaporated in vacuo leaves shining fusible
lamiiMB. The aqueous solution is decomposed by repeated evaporation into basic salt
and free butyric acid.

SubeUtution-derivaHve* of Butyric Acid.

paaoMOBprrmo A(m>. G^H^r'O*— Cahours (Ann. Ch. Fhys. [3] xix. 495) ob-
tained an add of this composition, by the action of bromine on dtraconate or itaconate
of potassium, to which he gave the name bromotriconio acid. It is now eommonly re-
garaed as a brominated derivative of butyric add, and as such finds its description
here. When bromine is gradually added, until slightly in excess, to a solution of
dtraconate of potasdum in 1} pts. of water, carbouc acid is evolved, and a heavy
yellowish oil is depodted, which is a mixture of two substances, the one an acid, the
other a neutral oil This is washed with water and treated with potash, which dis-
solves out the add, and leaves the neutral oil unchanged. On adding dilute add to
the alkaline solution, the add is deposited sometimes as a heavy yellowish oil, some-
times in fine etrstaUine needles : the two substances are identical in composition.

The oily add has a slight amber colour ; it has a peculiar odour, feeble at ordinary,
but irritatinff at higher temperatures. It is much heavier than water, in which it is
sli^tly soluble ; it is quite soluble in alcohol and in ether. It is partially decom-
posed by distillation, with formation of hydrobromio add fdmes, ana leaves a carbo-
naceous xendue. Sometimes the oily add changes spontaneously into a mass of
crystals. It is attacked by nitric add with dis^igagement of red fames. Stronff
potash-ley dissolves it, disengaging a peculiar odour, alter which the addition of add
no longer predpitates an oiL

The oily acid fbrms with ammonia an add salt, OH*(NH«)Br>0s.C«H'Br*0*, which
crystallises in yellowish white unctuous scales, easily soluble in water and in alcohol.
The silver-salt, C^H'AgBr'O', is obtained by adding nitrate of silver to a solution of

TT 3

6f>4 BUTYRIC ANHYDRIDK

the ammonia-Bait, as a curdy precipitate, which, after standing some time, imitea into a
pitchy mass.

IHinmobuiyric Ether, --C*B.\C^*)3t^\ is obtained with difficolly. A aolntion
of the acid in absolute alcohol is saturated at 70^ — 80^C. with hjdiobromie acid gas ;
the solution is distilled ; the distillate is mixed with water, and the resulting precipit«t«
ia washed first with dilute carbonate of soda, then with pure water, and finally dried
over oil of vitriol. It emits an irritating odour when heated, and has a "harp taste.

Further experiments are required to proye that Cahours' bromotricoiiic acia is the
true dibromobutyric acid, and it is to be regretted that its discoyerer should not have
fdlly cleared up this point. Cabours obtained the following results in attempting to
obtain dibromobutyric acid directly. Bromine was added to a solution of botyzate of
potassium, until a few drops of a brominated acid were precipitated; Ihe whole was
then evaporated to dryness, dissolved in alcohol, filtered, and a few drops of sulphunc
acid added, which precipitated an acid different from butyric acid and less odorooa,
but soluble in water and in aloohoL It did not appear to be identical with branio-
triconic acid.

DicHLOBOBumio Acn>. C^H'Cl^. (Pel o use and Gil is, Ann. €Sl Pbyai [3]
X. 447.) — ^The best method of preparing this acid ia to pass dr^ ddorine gas in bright
sunshine, through about 40 grm. of butyric add, plaoea in a laebig's buib-appsxmtii&.
At first, the absorption is very rapid ; subsequently, hydrochloric acid is disengaged,
and the liquid assumes a yellowish-green colour. The absorption becomes slower and
more diflcnilt, and the current of chlorine must be continued for several days be£bre
it ceases to be absorbed. Dry carbonic acid gas is now passed through it, at a tem-
perature of 80® — 100° C. to expel the hydrochloric add : the residue is dichlorobu-
tyric acid.

It is a colourless visdd liquid, heavier than water, and having a peculiar odour, some-
what like that of butyric and. It is insoluble in water, but entirely soluble in alo^oL
It can be distilled to a great extent without alteration, but a portion always deeom-
poses. It bums with a ^reen-edged flame.

Its potasdum-, ammonium-, and sodium-salts are soluble. Its silvep-salt is B|«ringl j
soluble.

Dichlorobutyric Ethtr, C*H»(C*H*)C1K)\ is prepared by pently heating an alcoholic
solution of didUorobutyiic add with sulphuric acid. An oily compound ether having
an ethereal odour, is deposited, which is washed with water and nistiUed.

Tbtrachlobobuttbic Acid. C*H*Cra*. (Pelouae and Gilia, ke. dtjy—Thm
acid is produced by the continued action of cUorine upon butyric add in bright boih
shine : the chloroDutyric acid at first formed is ultimately converted into a white,
solid, crystalline mass, which when pressed between p^>er, and crystallised from ether,
is obtained in the form of white oblique, rhombic prisms, which melt at 140® C, distil
without decomposition, and smell Uce butyric add. Its silver-salt» C^H'AgClK)', ia
sparingly soluble;

TUrachUyrohuttfrio Ether, C*H«(C^»)C1*0*.— In a solution of tetrachlotobutyrie
acid in several times its bulk of alcohol, the addition of oil of vitriol immediatelj
produces a crystalline mass, which melts at a gentle heat^ and separates into two layeiSi
the heavier of which is tetrachlorobutyric ether. It has an ethereal odour, and boras
with a green fiame, giving off white fames of hydrochloric add.

TmoBUTTBio Acid, C*HH)S - ^*^h1*" ^^T^o^'^'*^ "cid, (ITlrich, Ann.

Ch. Pharm. dx. 280.) — This add is produced by the action of pentasulphide of phos-
phorus on butyric add (p. 691). The substancea in equivalent quantities are distilled
together in a flask furnished with an inverted condenainff apparatus, the aetioin, which
is violent at flrst, being assisted towards the end by genUe heating. After it has con-
tinued for several hours, the mixture is distilled, and the reddish liquid^ which contains
butyric add and dissolved sulphur, as well as thiobutyrie add, is su^ected to fractional
distillation, the thiobutyrie add passing over at 130® C. It is a eolourlees liquid, of
almost insupportable and persistent odour ; boils at 130® C. ; ia aparinffly soluble in
water, readily in alcohol, and dissolves sulphur with yellowish colour. "With ttoetate of
leadf it forms a bulky white predpitate of thiosulphate of lead, C^HTPbOS, soluble in
a large quantity of hot water, also in hot alcohol, and separating on cooling, in small
colourless crystals. The salt decomposes readily, with separatioQ of solphiiSa of lead.

E.A.

mtrrwmta AnnmXBB. Anhydraut JSutyrie And, CH^^O* - ^^^|o.

(Gerhardt, Ann. Ch. Pharm. Ixyiii* 127.) — The formation of this body is analogous
to ^at of the organic anhydrides in general, that is to say, it is fermed by the action
of chloride of butyryl on an alkaline butyrate.

BUTYEIC ETHERS 695

It 18 prepared by treatixig 4 pts. of drr butyrate of Bodium with 2 pts. of oxychloride
of phosphoroB, the oxychloride being added drop by drop to the butyrate, as in the pre-
paration of acetic anhydride. The reaction consists of two stages, the first being the
formation of chloride of butyryl and phosphate of sodium :

SC^H'NaO* + POCl" = NaTO« + 3C*H'0C1.

and the second, the formation of butyric anhydride by the action of this chloride
on another portion of butyrate of sodium. When the reaction is complete, the mass is
dirtJUf^, and the distillate redistilled oyer butyrate of sodium, in order to oonycrt any
remaining chloride of butyryl. The distillate from, this is finally rectified, those parts
only being collected which boil at 190^ 0. ; the portions which pass over below this point
contain butyric acid, the formation of which cannot well be avoided, from the deli-
quescent nature of the butyrate of sodium.

Like acetic anhydride (p. 20), butyric anhydride may be prepared by the action of
benzoic chloride on butyrate of sodium. Fire pts. of benzoic chloride are mixed with
8 pts. of butyrate of sodium in a retort, and distilled, and the distillate rectified, at
lint over butyrate of sodium, and then alone.

Butyric anhydride is a colourless, very mobile^ and highly refracting liquid, of
specific gravity 0*978 at 12'5° C. Its odour is very strong, but not disagreeable, and
rather resembling butyric ether than butyric acid. It boils at 190^, and its vapour-
density has been found to be 5*38. Exposed to the air, it gradually attracts moisture,
and is converted into butyric acid. Poured into water, it does not dissolve like butyric
add, but rises to the surface as a colourless oiL In contact with aniline, it becomes
heated, and forms butyranilide (phenylbutyramide) :

(C*H»0)*0 + 2(K.H«.C«H*) - 2(N.H.(>H».C^H»0) + H»0. E. A.

SUmiO MFMMMtB* These compounds are formed from butyric acid by the
■ubstitation of 1 at of an organic radicle, such as ethyl, methyl, && for 1 at of hy-
drogen. They are for the most part formed by the direct action of butyric acid on
the alcohols.

BuTTRATB OF AixTL. CBP'O* - C*H»((>H»)0«.---Obtained by distilling butyrate
of silver with iodide of allyL After rectification, it is a colourless oilv liquid, lighter
than water, soluble in ether, smelling like butyrate of ethyl, and boihng at about
140® C. Heated with potash, it yields allyl-alcohol and butyrate of potassium.
(Cahonrs and Hofmann, FhiL Trans. 1857, p. 656.)

BUTTB4TB OT Amyl. C«H»«0« - C*H»(C»H")0«, is a liquid boiling at 17-6<» C.
(Belffs). Specific gravity 0*852 at 16^. Index of refiraction » 1402.

BunsATB OF Ersn. Butyrio Ether. CTa»K)» » O'H'CC-ff)©'.— This ether is
readily produced by the action of butyric add on alcohol, sulphuric add being like-
wise present It is also formed, according to Berthelot, by distilling a mixture of
1 pt common ether, 3 pts. butyric add, and 7 to 8 pts. sulphuric add ; but the dis-
tiUate contains a huge quantity of free butyric add. To prepare it, 2 pts. but^c add
are dissolved in an eoual weight of strong alcohol, and 1 pt sulphuric add is added
to the mixture. The liquid becomes heated, and butyric ether immediately rises to
the sorfkoe ; bat to complete the transformation, it is necessaxy to heat the mixturo
for a short time to about 80® C. The butyric ether is then decanted, shaken up several .
times with water, finally with addition of chalk and chloride of caldum, then dried
over chloride of caldum and distilled.

Bntyrato of ethyl is a transparent, colourless, very thin liquid, of specific gravity
0*90198. Boils at 119® C, under a pressure of 0*7465 mm. Va^ur-density m, 4*04.
It has an agreeable odour, like that of pine-apples, and a sweetish taste, with bitter
after>ta0te. It is vezy sparingly soluble in water, but dissolves in all proportions in
alcohol ami in ether. It is slowly decomposed by potash, into butyrate of potassium
and alcohoL

To the presence of small quantities of butyric ether, the peculiar flavour of pine-
axiplea, melons^ and some other fruits, is due. Its formation in the frxdt recdves an
ODvious explanation, from the readiness with which the saccharine matters present

Con the one hand, into lactic and butyric acids, and on the other, into fdcohoL
^ine-flavoured rum, known as pine-apple rum, owes its flavour to the presence
of this ether. When freshly distilled from molasses^ rum has but little flavour, but
this oomes out on keeping, owing to the fi^t that a small quantity of butyric add
eontained in it, graduaUy combines with the alcohol to form etner.

A solution of butyric ether is vezy extendvely used in perfrimery, and in oonfec-
tionay, under the name of pine-i^ple oil It is prepared for this purpose by tiie fol-
lowing prooeM. Butter is saponified bv a strong solution of ^taah-lej ; the soap is
~ in very lit^e absolute aloohot and to the solution is added a mixture of

YT 4

696 BUTYRINS.

alcohol and snlphtiric acid, until a stzonglj acid reaction is set up. The vhole is thei
distilled, heat being applied as long as anything comes over with a firoitjr odoor.

BtTTTBiLTB OF Etkylbmb, C'«H'"0* - ^^^^j"! ^*» » obtained by heating hio.

mide of ethylene for seyeral days to 100^ C. witii bntyrate of silrer and a little free
butyric acid, exhausting the prodact with ether, and distilling firactionaUy :

2(C*H'O.Ag.O) + C«H*Bi:» - 2AgBr + (C*H'O)».(C«H«)''.0«.

It is a colonrless liquid, of specific graTity 1'024 at 0^ C. ; smeUs like bntyrie acid, ud
boils at 239® to 24I0 C. (A. Wurtz. Ann. Ch. Phya. [3] Iv. 400.)

BUTTBATB OF G1.TCIBTX.. See BUTTBINS.

BuTTBATB OF Mbthtl. 0»ff»0* -1 C«BP(CH")0«. — A mixture of 2 pts. butyric
acid with 1 pt. of wood-spirit and 1 pt. of strong sulphuric acid, becomes heatfd aod
separates into two layers, the upper of which is butyrate of methyl In order thit
the transformation may be complete, it is well to agiti^ the mixture, anderen to nuin-
tain it for some time at a temperatore of bom 6Q9 — 80^ G. The product is purified
like the ethyl-compound.

Butyrate of methyl is a transparent colourless liquid of spedfie gravity 1*0293.
Boils at 102<> C. Specific heat is 0*4918. Latent heat of yapour, 87'33. Vapoin«-
density, 3*52. It has a pleasant odour, somewhat resembling that of pine-applM.
It is scarcely soluble in water, but perfectly soluble in alcohol and in ether. £. A.

8U 1' I JtlBIV* This name was given by Berthelot to a compound formed from
butyric acid and glycerin, to whi<£ he at first assigned the formula G"H*'0'
(« 2C«H*0* -I- 2CB>0* - 3H*0), but which he afterwards found to be identieal
with dibutyrin (p. 695).

BirrnzVB. (Berthelot, Ann. Ch.Fhy8. [3] xli. 261.)— By the direct action of
butyric acid on glycerin, a series of compounds analogous to the acetins is obtained
They are monobutyrin, C»H"0\ dibutyrin, C"H»0*, and tributynn, C"H*0^. Thej
contain the elements of glycerin and butyric acid, minus those of water. Their foona*
tion may be thus expressed :

Glycerin. Bu^rHc Mono-

acid, butyrixk

C»H»0« + 2(C<HH)«) - 2H*0 - C"H«»0»

Glycerin. Butyric Dibntyrin.

Cra«C« - 8(C«H«0«) - 8BP0 - C"H«W
Glyoarta. Butyric Tributjiin.

acid.

Viewing glycerin as a triatomie alcohol, we may consider the butyrins as gljovin

H* V ^* ^ ^^<^^ ^t % or 8 at of hydrogen are replaced by the radide batyiyl,

C*H'0.

The butyrins are deoompoaed by alkalis, and also by the alkaline earths, baiTtaaDd
lime, with formation of a butyrate and elimination of glycerin. BissalTed in alooiiol
and treated with hydrochloric add, they yield butyric ether and glycerin.

MoNOBUTYRiK, C^H>^0< - H« iO«. —This body is formed, but only in nnaD

proportions, by exposing a mixture of butyric acid with excess of glycerin, to tiie
action of the sun or of difi\ised daylight for several months. It is also obtaioed \ff
heating butyrio acid with glycerin to a temperature of 200^ C. for three boon, eve
beinff taken not to exceed this temperature. It is a colourless, neutral, odori£eioiu»
oily liquid, having an aromatic and bitter taste, without any after-taste. At - 40^ C^
it remains liquid, and as mobile as at ordinary temperatures. It rapidly aadiflcs vfaca.
exposed to the air.

(C»H»r)
DiBUTTBiN, C"H*0» - HVO*.— Whenever in the preparation of mono-

(C*H'0)M
butyrin, the temperature exceeds 220^ C, some dibutyrin ai|peai8 to be fonned, bat iC
is best prepared by heating a mixture of gljrcerin and butyric acid to 276° fi* ■*^"r
hours. Xt is a colourless, neutral, oily,odonferous liquid, of specific grarity 1"031. 1*
volatilises at 320° without perceptible alteration. Cooled down to -40®, ^"^
liquid, but its fiuidity diminishes. By aqueous ammonia, it is decompoaed, mta
formation of butyramide.

BUT YRITE — BUTYROL ACTIO ACID. 697

Tbibuttbxv, C**H"0* — fC*H'w(^** — '^^ substance is fonned by heating

batyrin with 10 to 15 times its weight of butyric acid to 240° C. for four hours. It is
ft neutral, oily liquid, with an odour analogous to that of the preceding compounds,
and a pungent taste, with irritating aftertaste. It is very soluble in alcohol and
ether, but insoluble in water.

Natural JSutyrin, — A butyrin which is probably tributyrin, is contained in small
quantities in butter, along with caproin, caprin, olein, and margarin. It has not been
obtained free from these substances. According to Pelouze and G^lis, this compound
may be prepared artificially by gently heating a mixture of butyric acid, glycerin, and
concentrated sulj^huric ado. On adding a large quantity of water, a slightly yellowish
oU. separates, which must be washed wiui water, in which it is insoluble. It is soluble
in all proportions in alcohol and ether, from which solutions it is separated by the
addition of water. Saponified by potash, it yields glycerin and butyrate of potassium.
It has not been obtained pure, and is most probably a mixture of the butyrins above
described* £. A

BUTIMITB* A compound formed from butyric acid and mannite in the same
manner as the butyiins are formed from butyric acid and glycerin. Its properties
hare not been described. (Berthelot^ Compt. rend, xxxviii. 688.)

The same name is sometimes applied to bog-butter {q. v.)

BUT I JtOOB&OSSnxnr. By the action of hydrochloric add on a mixture
of butyric acid and glycerin, a product (first observed by Pelouze) is obtained, which,
according to Berth el ot (Ann. Ch. Phys. [3] xli. 303), is a mixture of the compounds
C«H«fC«H'0)C10« and C>H»(C*H'0)CPO, that is to say, of chlorhydrin (C»H'C10«)
and aichlorhydrin (CH'Cl'O), in ^ch of which 1 at. Il is replaced by butyiyl. No
method of separating these two compounds has yet been devised.

smmoZJUC acid. Br o m e i s (Ann. Ch. Pharm. xlii. 63) stated that butter
contains an oily acid resembling oleic acid in most respects, but differing from it in
not yielding sebacic acid by dry distillation. Bromeis assigned to this acid the for-
mula C^H**0*.HO» It appears, however, from the experiments of G^ottlieb, that it
is really identical with oleic acid, and exhibits the characters observed by Bromeis
only after it has been considerably altered by exposure to the air.

rOBZO ACZB. See Bog-btttteb (p. 617).

(C«H^O)">
lO&ACTZO ACZD. CE^O* » C«H'OV 0*. — This add, which is

deriv^ from lactic acid, (C»H*0)'[.H«.0* by the substitution of 1 at: butyiyl for 1 at.
hydrogen, has not yet been obtained in the free state; but Wurtz (Compt rend,
xlviii 1092) has obtained its ethyl-salt, (C*H*0)''.C*H'O.C«H^O^ by digesting chloro-
lactate of ethyl with an alcoholic solution of butyrate of potassium in the water-bath
for several days, then filtering to se|»arate chloride of potassium, treating the filtrate
with chloride of caldum, and rectifying :

(C»H*0)''.C*H» aO + C*H»O.K.O « KQ + (C»H*0)".C*H'O.C«H«0«.

ChloroUctate of ethyi. Butjrrateof ButyrolacUte of ethyi.

potaasium.

It is an oily liquid, of specific gravity 1*024 at 0^ C, having an odour something like
that of butyric add, insoluble in water, soluble in alcohol, and boiling between 200^
and 210^ C. The formation and constitution of this compound tend strongly to sup-
port the opinion that lactic acid is dibasic (See Lacho Acm.)

BUTIBOVB. CH^O. — This body is the acetone or ketone of the butyric series,
and is, therefore, homologous with acetic acetone. It represents butyral, in which 1 at.
of hydrogen in the radide is replaced by trityl :

C«H'0> Q^HWH^)0>

H J H J

Butynl. Butyrone.

Its formation is analogous to that of its homologue, acetone. Butyrate of caldum
carefully distilled in small portions is decomposed into butyrone and carbonate of
caldum :

2(C*H'CaO«) « Ca»CO» + C^"0.
Butyrate of Carbonate Butyrone.
cuclum. of calcium.

But when larger quantities are decomposed, the results are not so precise. The crude
product is composed of at least four substanceff, butynU, butyrone, and two other sub-
stances of the ketone series. The butyrone is obtained pure by rectification, those
parts being collected which boil at 140^ — 146° C. and these are again rectified, until
a product of constant boiling point is obtained.

698 BUTTRONE — BUTYRYL.

Bntyrone, when pure, Ib a colourless limpid liquid, haying a pecolisr penetnting
odour, and density « 0*83. It boils at 144^ C, and its vaponr-density has been fomd
to be 4*0, which corresponds to two Tolumes for the fonnnla CH^^O. SoBQimded
by a mixture of solid carbonic acid and ether, it solidifies to a oystalline nuua It ii
insoluble in water, but quite soluble in alcohol. It bums with a luminous flsme. It
immediately takes fire in contact with chromic acid. It is energeticslly attacked hj
nitric acid, with formation of nitropiopionic acid, C*H*(NO')0*, and of an ethereal
liquid, which is probably butyrate of tritvl, C*H'(C»H*)0*

Distilled with pentachloride of phosphorus, butyrone yields a compoond, (7H^
which Chancel terms ehlarobutyrane. It is a colouriess liquid, of penetratuig odov,
lighter than water, and insoluble therein. It bAQs at 116^ G. Its alcoholie solntioB
does not cloud nitrate of silrer.

From the crude product of the distillation of bntyrate of ralcium, two sahstaseei with
definite boiling points may be separated by treating the crude distillate with add bqI-
phate of sodium, to remove butyral and butyrone, and subjecting the lemaining liqoid
to fractional distillation. One of these boils at 180^ C, and has the specific grant/
0-827. It has the formula C»H»«0', which is that of methyl-buty rone, CrB"(CH»)0,
ormethyl-oen a n thy 1, CH*.CWH). The latter view of its composition is suggested
by the fact that it yieldis csnanthic acid when oxidised by nitric aad. The other ooo-
pound boils at 222^ C, and is a pale yellow Uquid, which becomes solid at 12^ C. Iti
composition is C'^H^O, which would correspond to tetryl-butyrone, CV(G*H*)0,
or te try 1-ananthyl, C^H*.C'H*K). It appears to yield butyric and mnanthir aada
by oxidation. (Limprieht» Ann. Ch. Phann. cviii 183.)

According to Frieael (Ann. Ch. Pharm. criii 126), the crude liquid obtained I7 the
distillation of butyrate of calcium, contains, amongst other products, ethyl-bntjryl,
C*H*H) <s C'H*.C^H'0, a colourless liquid having a biting taste, an aromatie odov
like that of butyrone, specific gravity » 0833 at 0^ C, and vaponr-densitj-S-M,
and a much smaller quantity of methyl-butyryl, C*H**OsCH*.C*H'0, ofspediSe
gravity 3*827 at 0^ C, and vapour-density 3-13. £. A

BUTTRO VITKIO ACIB. Thia name has been applied to the product of the
action of nitric acid on butyrone.

BmnmtowxTBi&B or CTJuma or t»vtt&. CWS - C^.CN.-

This body is best prepared by disfilling butyrate of ammonium or butjiamide with
anhydrous phosphoric acid:

C^H"NO« - 2H«0 - C<H»N.

Butyrate of Butjro-

•mmoniam. nitrile.

It is a transparent colourless oil, of specific gravity 0*795 at 12*6^0., and boi&g it
118*6*'. It has an agreeable aromatic odour resembling l^t of bitter-ahnond oil It
dissolves in boiling potash, with evolution of ammonia and fonnation of bntyiate of
potassium:

C^H^ + KHO + H«0 « C«H'KO« + NH".

Butjro- Batyrate of

nitrile. poCutliiin.

E.A

A name applied to trichloride of antimoDj, od
account of its buttery consistence and fusibility. Other chlorides of like oonsiitence
have also received similar names, e, g. Butyrum stanni, Butyrum jrifiei, &e.

Syn. of BUTTRTL-VBBA.

C^H'O. — The radicle of butyric add and its derivatives. Tb/tU'
lowing compounds of it are known :

Bromide of butyryl C*H»O.Br

Chloride of butyiyl • . . •
Iodide of butyryL ....

Hydride of butyryl (but^c aldehyde) .
Oxide of butyryl (butyric anhydride) .
Hydrate of butyryl (butyric acid)
Butyryl-propyl (butyrone) . « ,
Butyiyl-urea or butyral-urea

The name butyryl has likewise been applied to the hydrocarbon C*H*, sometimea
regarded as the radicle of butyric add.

Bbokide of Bxtttbti^ C^H'CBr, is produced by the action of bromide of pho^ibou
on butyric add at 90<>— 100® C, purified by washing with water anirectiflcatioB.
(Bi champ.)

Chlojudb of Buttbtl. C*H^0.C1 This body, like its homokgw^ «U«^ ^

c*H»o.a

CH'O.I

C*H'O.H

(C^H'O)".©

C*H»O.H.O

C^H'O.CJT

N«(CO)''.H*.eH'0.

BUXINE — B YTOWNITE. 699

acetyl, is pfoduced by the action of 1 at ozychloride of phosphorofl on 3 at butyrate of

eodioxn:

8C«H»NaO« + POa« » 3C*H^0a + Na»PO*.

Botyrateof Oxvchlorlde Chloride of Phosphate

•odium. ofphotpbate. butyrjl. ofiodium.

The powdered bntyrate ia gradually added to the ozychloride contained in a retort :
for if the ozychloride were at once poured on the butyrate, a large quantity of anhy-
dzooB butyric acid would be formed. The mizture is distilled, and the liquid distu-
late rectified over a small quantity of butyrate of sodium, the temperature oeing kept
as low as possible, in order to prevent the anhydrous acid formed during the rectifica-
tion firom distilling oyer with the chloride.

Chloride of butyiyl is a colourless, mobile, strongly refracting liquid, heavier than
water, and fuming slightly in the air. Its boiling point is 95^. It has a pungent
odour like both butyric and hydrochloric acids. It is immediately decomposed by water
into hydrochloric and butyric acids :

C'H'Oa + B?0 - C*H«0« + HCL

Chloride of Butyric

butyryl. acid.

With butyrate of sodium it yields chloride of sodium and butyric anhydride :

C'H^OCl + OH'NaO - NaCl + C»H"0«.

With ammonia it yields butyramide and hydrochloric acid :

C*H'Oa + NH« - OH»0.H«.N + Ha

loDnn OP BurntTL, C^H'0.1, produced by distilling butyrate of potassium with
iodide of phosphorus, is a brownish liquid, which melts in contact with the air, and
boils between 146<' and 148<' C. (Cahours.) £. A.

BUTIMXJa-iniaA. See Cabbamidb.

smcxva. An alkaloid said to ezist in all ports of the boz-tree (Bwnu semper^
virens.) According to Faur^ (J. Pharm. zvi 428) it is obtained as an uncrys-
tallisablemassyby boiling the aqueous solution of the alcoholic eztract of the bark
with maffnesia, ezhausting the resulting precipitate with alcohol, decolorising with
animal charcoal, and evaporating. According to Oouerbe (J. Pharm. Januair 1854,
p. 61), it may be obtained in the crystalline form by treating the sulphate with nitrio
add, whereby an admized resin is destroyed or rendered insoluble, and precipitating
by an alkalL

Buzine has a bitter taste and ezcites sneezing ; it blues reddened litmus-paper ; is
nearly insoluble in cold water ; dissolves readily in alcohol, sparingly in ether ; insoluble
in alkalis. It is decomposed by nitric acid. Its salts are more bitter than the base
itself^ and yield a gelatinous precipitate with alkalis. The sulphate is said to form
crystalline nodules.

Trommsdorff (Tromm. K. J. zzv. [2] 66) obtained from boz-leaves a substance
probably identical with Faur^'s buzine.

BTSSOUm. A name applied to the fine capillary implanted crystals of acti-
noUte, found on the 6t Qothard and in the l^rroL

MTM&fJB MITUJE. The bundle of threads by which the common muscle
(Afy<iZitf edtdis) adheres to other bodies, consists, according to Scharling (Ann. Ch.
Pharm. zli. 48), of a mass resemblins homy tissue, containing a small quantity of fitt
According to Layine (J. Ghem. m6d. zii. 124) it contains the salts which occur in
0ea-water.

VTTO W M ITM* A nanular massive mineral occuiring in large boulders near
Bytown, Canada West The grains have one perfect cleavage and indications of
another oblique thereto. Harmless « 6 to 6*5. Specific gravity 2*80 (Thomson);
2*783 (Hunt). It has a greenish- white colour and vitreous Instre, pearly on the
cleavage surface. Translucent According to Thomson ( J. pr. Chem. viii 489) it
contains 47*57 per cent silica, 29*65 alumina, 906 lime, 7*6 soda, 3*57 ferrous ozide,
0*2 magnesia, whence it appears to be a variety of barsowite (p. 517), the alumina being
partly replaced by ferric ozide and the lime by soda. T. S. Hunt (SiU. Am. J. [21
zii. 213) regards it as a rariet^ of anorthite. A dark bluish-green granular mineral
or rock from Perth, Canada, wnich has been called BytownitCi is considered by the
same chemist as a mizture of bytownite and hornblende.

700

CABBAGE — CACAO.

OA8BACIB. (See Bbassica.) — Infusion of red cabbage, obtained by pouring hot
water on the leaves, is a convenient test for adds and alkalis. A certain quantity of
alkali, just sufficient to neutralise the acid in the juice, turns it blue ; any further
quantity changes the blue to green ; and acids turn it red.

C ABB A omnu A bitter principle, obtained from the cabbage-tree {Gtofraga
inermis^ or G. jajruucensia), also called Janudcine (g. v.)

CABOOXdk A mineral resembling red jasper or felsite, found in the diunanti-
ferous sand of the province of Bahia. It has a density of 3*14 to 3*19 ; Bcntches
fflass slightly ; turns white before the blowpipe, but does not melt ; dissolves partially
in warm strong sulphuric acid, leaving a white earthy residue, which dissolves in the
acid at a higher temperature, and is precipitated therefrom by water. Dam oar
(L'Institut zzi. 78^ found in the red massive mineral, phosphoric add, alumina, line,
baryta, ferrous oziae, and water.

CACAO. The seeds or leaves of the Theobroma cacao and other BP^a of the
same genus (Nat Ord. 8terouliacea\ natives of South America and the West Indies,
which are extensively cultivated in those countries, and in the tropical parts of Asia
and Africa, are remarkable for their nutritive properties, and yicQd the weIl-fa}oini
substances, cocoa and chocolate. They contain la^e quantities of fiitty matter and
vegetable albumin, and about 2 per cent, of an organic base, tkeobrondnit CHPNH)',
resembling caffeine. The ash is very rich in phospnoric add. Shelled beans of good
quality eudbit) before roasting, the following composition per cent : 52 cacao-batter,
20 albumin, fibrin, &e., 2 theobromine, 10 starch, 2 cellulose, 4 inorganic matter, ind
10 water, besides small quantities of colouring matter and essentul oiL (Payei^
Traits de Pelouce et Fr^v, vL 529.)

Cacao-beans have also been analysed by Tuehen (Inaugural Dissertation, 06t-
tingen, 1857 ; and by A. Mitscherlich {Jkr Cacao imd die Ciocolade, Berlin, 18S9),
wiUi the following results :

Tuehen.

MItieberMcb.

Theobromine •

Guajra-
qufl.

SorU
nam.

Caracal.

Para.

Marag.

nan.

Trinidad.

Guava.
quiL

Ciraai

0-63

ojye

055

0-66

0*38

0-48

12-1*5

Cacao-red .

4-56

6-61

6-18

618

6-56

3*5- 5

Cacao-butter .

86-38

36-97

35^

34-48

88*25

86*42

45-49

4S-49

Glutin

S-96

3-ao

8-21

a-99

8-18

3-15

13-19

SUrch

0-53

0-55

0-62

0-28

0*72

0-51

14—18

181-17

Gum'. . . .

1-58

1-19

0-78

0-68

0-61

Extractive matter .

8*44

4*18

6-22

6-(.8

332

5*48

Humic acid •

8-87

73*

928

863

8-08

9*85

Cellulose .

80*50

30*00

28-66

80-21

»-77

89-86

3-6

A*-h . • . .

8*03

8-00

2*91

3*00

2-92

2-96

Water

6-20

6*01

5*58

6-55

5-48

4-88

fi-6..6-3

Starch-sugar

—

0-34

Cane-sugar

—

0-2S

98-38

99'C8

99-48

99 88

99 19

99-84

Mitscherlich's results do not differ from those of Fi^n, more than might be a-
pected in the analysis of different varieties ; those of Tuehen, which differ viddy
from both the preceding, piobablv refer to the unshelled beans.

The starch of cacao-beans exhibits granules of peculiar form, quite iiriand htm
those of the cereals and lesuminosse ; by this means, the flour of either of the latter
may be detected when used to adulterate chocolate.

The ash of the shelled beans has been analysed by Letellier (Pelonze eiFiioLj,
loc, cit), and by Zedeler (Ann. Ch. Pharm. Ixxviii. 848), with the following resultB :

K«0 Ka»0 CaH) MgH) SO* CO* P*0» 3Fe«0».PK)» CI SiO«

33*4 110 170 4-5 1*0 29*6 0*2 3 3 (Letellier^

37-14 1-23 2-9 16*0 15 1*2 396 0*17 1*7 (Zedeler),

The kernels of the theobroma are used as an article of nutriment, either is tbe
natural state, or prepared in various ways. The simplest and best form is that <tf the
seeds roughly crushed, termed cocoa^iba^ which, however, require two hoazs' boiling
as, owing to the peculiar nature of the inner seed-coating, which passes down into the

CACHALAGUA — CACOTHELINE. 701

ralMtanee of the ootyledons, the prolonged applicatioii of heat and moisture is neoessaiy
to diflBoIre the oontents. Flak^^coeoa is merely the seeds crashed between rollers. To
prepare ehocoUUe^ the beans, after being carefully picked, to free them from mouldy or
vorm-eaten ones, are gently roasted over a fire in an iron cylinder, with holes in the
ends to allow the raponr to escape. When the aroma begins to be well developed, the
process is eonsidered oomplete. The beans are then turned out, cooled, and fireed fh)m
their husks by &nning and sifting. The husks, which often amount to 20 or 25 per
cent of the be^ns, should not be thrown away, as they contain half their weight of
soluble or mucilaginous matter, which yields a tolerable nutriment. The seeds are
then converted into a paste, either by trituration in a mortar heated to 130^ F., or more
generally by a machine impelled by steam, and the paste is put into moulds and sent
into the market ; it always improves by keeping. Sometimes the beans, before being
roasted, are left to rot or ferment in heaps, in order to separate the kernels from the
soft pui^y mass which sunounds them in the fruit

The chocolate of different countries varies according to its mode of preparation, and
the ingredients contained in it. When the kernels alone are used, or only a little sugar
is add^ the chocolate is called '' Chocolat de sant6." But vanilla, cloves, cinnamon,
and other aromatics, are frequently added; also rice, almonds, starch, &c Simple
chocolate is mostly preferred in this country, the perfbmed sorts in France, Italy, and
Spain, where the consumption is immense. (See ur^9 Dictionary of Arts, Mani^aO'
tures, and Mine9, l ; also Penny Cydopadia, art Thbobroxa.)

Cacao-btUterf or Cacao^faif is extracted from the beans by pounding them in a slightly
heated mortar, till they are reduced to a pulp, then adding a small quantity of water,
and squeezing the pulp in a cloth between two plates of metal previously heated to the
temperature of boiling water. It has an agreeable taste and odour, is white, semi-
transparent) insoluble in water, soluble, especially with aid of heat in alcohol, ether,
and oil of turpentine. It has the consistence of suet^ melts at 30^ C, but does not
resume the 8<md state till cooled to 23^. It consists chiefly of stearin, with a little
olein. It is used more in France than in this countiy, for making soap, candles, and
pommade. The soap made from it must not be confounded with that made from
eoeoa-nut ail, which is a very different product, obtained from the cocoa palm {Cocos
nueifera).

Cacao-red is the colouring matter of cacao-beans. It is separated by precipitating
the aqueous or sicoholic decoction of the beans with acetate of lead, and decomposing
the washed precipitate with sulphuretted hydrogen. The solution thus obtained is
neutral, has a bitter taste, and yields lilac or greyish precipitates with acetate of lead
and protochloride of tin ; dark green, or brown-green, with ferric salts ; and green of
various shades, or sometimes violet with ferrous salts ; the colour of the precipitate
varies in each case, according as the cacao-red in the solution is more or less mixed
with other substances.

The solution of cacao-red absorbs ox^rgen during; evaporation, and becomes add, the
colouring matter being in fact converted into a kind of tannic acid. This modified cacao-
red gives, for the most part green precipitates with iron and lead salts ; that obtained
from Guayaquil cacao, gives pale oddish precipitates with acetate of lead and with
lime-water, reddish-white with sulphate of masnesium and ammonium. It is preci-
pitated by gelatin, whereas unaltered cacao-red is not.

The alteration produced bv the roasting of cacao-beans, appears to affect the cacao-
red more than any of the otner constituents.

O ACTIff ftTi A IMT A» or OAVCBA &ACIirA« is the South American name of the
Chircnia ekUensis, a gentianaoeous plant which, according to Bley (Arch. Pharm.
xxxviL 85), contains resin and a bitter principle.

OACB03bOWCk A variety of Opal {q, v,)

OACBOUTAWirZOi or OAOHUTZO AOSD* See Catbohu.

OAOOSTIto See Absbnidbs of Hbthtl (p. 403).

O AOOTBaiAra. C»H«N*0» « C?»H«(NO«)«N«0».— A product of the decompo-
sition of brncine by nitric add (p. 682). It pully separates in orange-yellow crrstalline
flakes after the action has ceased, and an additional quantity may be obtainea by pre-
cipitating the red liquor with alcohol. From a solution in water strongly acidulatea with
nitric acid, it separates in yellow scales. It is but very sparingly soluble in boiling
water, still less in boiling alcohol, and insoluble in ether. When heated, it decomposes
suddenly, in the manner characteristic of nitro-compounds. Exposed to difiused light
in a stoppered bottle, it soon becomes dark brown on the surface. Potash dissolves it
easilv, forming a yellowish-brown liquid. Ammonia dissolves it immediately, forming
a yellow liquid, which on boiling changes first to green, afterwards to brown. Caco-
thaline unites with metallic oxides ; with baryta, it forms a soluble compound, con-

702 C ACOXENE — CADMIUM.

taining 20^H*^^0'.BaK). It combines also with adds, hot the ntti an dMom-
poaed by water. When dichloride of piatinum ia added to a aoliitioii d caeotiieliM
in hydrochloric acid, the liquid, after a few hours, yielda a oystalline pndpitato oobp
taxnmg 48 per cent, platinum « C»H«N*0».HCl.FtCl«.

When caootheline is left for some hours in the red nitric solution in whidi it hu
been formed, it changes into another body, which has the colour of ehrome-yeDow, is
insoluble in water, and explodes when hei^^d. (Strecker, Commit. lend. xzzii. 52.)

OAJOOMMMMm A native ferric phosphate, found in the Hrbeck mine, near
Zbiron in Bohemia, in radiated tufts of yellow or brownish-yellow colour, beooming
brown on exposure. Specific gravity « 8-38. Hardness •■ 8 — 4. Of the following
analyses, a and b are by yon Hauer (Jahrb. geolog. Beichsanst 1854, 67); c 1^
Richardson (Thomson's Mineralogy, i 476) :

PK)» Fe«0» HH) CaK> MgK) 8i0«

a . . 19-63 47-64 3273 — — — - 100

b . . 26-74 41-46 32-83 — — — - 100

c . . 20-6 431 30-2 M 0*9 21 - 97*9

« and c agree nearly with the formula 2Fe«0*.P*0* + 12 aq., or 3/e>0.2/e^ 4-12 aq.
The analysis 6, which, however, is said by von Hauer to have been made with less pore
material, approaches more nearly to 3Fe*0'.2P*0* + 20 aq. Former analyses hf
Steinmann, which showed 10 — 11 per cent, alumina, were doubtless made with mpuK
specimens. (Rammelsberg's Mineralchemie, p. 831.)

OACTVS. Yogel obtained from the flowers of Cactus tpeeiotus^ by extraetioD
with weak alcohol, 80 per cent of a carmine-red dye, insoluble in ether and in ab<
solute alcohoL The petals, after the removal of this substance, yielded to a mixtBie
of alcohol and ether, from 6 to 10 per cent of a scailet substance. Both these eoLoo^
ing matters are soluble in water. (J. Pharm. xxii. 664.)

F. Field (Chem. Soc. Qu. J. iiL 57) has analysed the ash of a species of cactas (not
named) growins in Chili The fresh plant yielded 1-36, the dry plant 16*79 per cent
of ash, containing in 100 pts. 67*16 pts. of soluble and 42*73 of insoluble salts. The
air-dried plant yielded 86-09 per cent water. The composition of the ash per cent
is: 7*83 K'O, 2819 Na'O, 1066 CaK), 776 MgH), 034 Mn«0», 6-09 S0». 1640 SiO«.
6-40 P*0*, 1-38 phosphates of calcium, magnesium, and iron, and 14-87 NaCL

OABBT*B JPUMUIO XiIQUXB. See Absbnidbs of Mrtstl (pw 403).

C ABia-OUML A very pure kind of gamboge, probably from Hebradndron earn'
hogidides,

CilimmUKt Symbol Cd. Atomic weight 66. Atomic Tolume in the gaseous
state a 1.

This metal is frequently found associated with sine, and derives its name from ead-
fnia fossUiSj a denomination by which the common ore of zinc was foimeriy known.
It appears to have been discovered about the same time (1818) by Stromeyer (G3h.
Aim.lx. 193) and by Hermann (ibid, lix. 96, 113 ; Ixvi 274), but its more ead
investigation is due to Stromeyer.

Cadmium occurs in small quantity in several varieties of native sulphide, carbonate,
and silicate of zinc, viz. in the radiated blende of Prsibram in Hungary, to the amoont
of 2 or 3 per cent; in the blende of Nuiasi^re, to the amount of 1*14 per cent.;
in silicate of zinc from Freiberg and from Derbyshire ; in caibonate of smc from
Mendip ; in carbonate and silicate of zinc from the Cumberland mines; in the one
ores of the Harz and of Silesia. The zinc flowers obtained as a secondary product in
the smelting of the Silesian ores, contain, according to Hermann, as much ^^ ^^ Pf'
cent, of cadmium. Commercial English zinc frequently also contains cadmium. The
only pure native compound of cadmium is the sulphide called Greenockite^ foond at
Bishopstown in Renfrewshire.

Preparation. — In the process of reducing ores of zinc, the cadmium which tiiej
contain comes over among the first products of distillation, owing to its greater Tob-
tility. It may be separated from zinc in an acid solution by sulphydric add, which
throws down the cadmium as a yellow sulphide. This sulphide mnolves in ooaeen-
trated hydrochloric acid, affording the chloride of cadmium, from which the carbonate
may be precipitated by an excess of carbonate of ammonia. Carbonate of cadminmis
converted by ignition into the oxide ; and the latter yields the metal when mixed with
one-tenth of its weight of pounded coal, and distilled in a glass or porcelain retort, at
a low red heat

Properties, — Cadmium is a white metal, with a slight tinge of blue. It has »
strong lustre, and takes a fine polish ; by exposure to the air, it gradually aoquira a
whitish-grey tarnish. It has a compact texture and fibrous fracture, and easily 07**
tallises in regular octahedrons. It is soft, though harder and more teoadoiu thaa

CADinUM: ALLOYS— CHLORIDE. 703

tin ; Teiy flezibley azid cnckles like tin when bent ; Teiy malleable and dnctile. Its
nedflc graTitj is, after fusion, 8'604, after hammering, 8*6944. Specific heat 0-05669
(Kegnanlt), 0*0676 (D along and Petit). Cadmium melts below a red heat» and
Tolatilises somewhat below the boiling point of mercury without emitting any par-
ticular odour. The density of its vapoar as determined by experiment at 1040^ C. is
8*94, referred to air as unity (Deville and Troost, Ann. Ch. Pharm. cxiiL 46).
Now the calculated value for a condensation to 1 vol is found by multiplying the
atomic weight by the density of hydrogen » 66 x 0'0693 — 3*88. Hence cadminm-
Tapour follows the usual law of condensation (p. 441).

Cadmium dissolves in hot hydrochloric or djdut« sulphuric acid, taking the place of
the hydrogen in the acid ; but its best solvent is nitric acid. The bromide, iodide,
and many of the oiganic salts of cadmium, the acetate for example, are soluble in
water; the rest, e»g. the carbonate, borate, phosphate, and arsenate, are insoluble in
water, and are obtained by precipitation. Most cadmium-salts are colourless ; they
have a disagreeable metaUic taste and act as emetics. The solutions, even of the
neutral sslts, redden litmus. Those cadmium-salts which are insoluble in water are
soluble in sulphuric, hydrochloric, or nitric add, also in ammoniacal salts.

Cadmium, m nearly all its compounds with electro-ne^tive elements, plays the part
of a monatomic radide, the chloride being CdCl, the oxide Cd'O, &c.

CAl^BmnCf Al&OTS OV« But few alloys of cadmium are known. 100 pts.
copper retain at a red heat 82*2 pts. cadmium, forming an alloy having nearly the com-
position CdCu'. It is very brittle, has a fine-grained scaly structure, and a yellowish
white colour. With mercury, cadmium forms a hard, brittle, silver-white amalgam,
whidi oystallises in octahedrons, and contains 21*7 per cent cadmium « Cd&Lg*.
100 pts. platinum retain at a red heat, 117*3 pts. eaidmium » Cd'Pt The alloy
is amost silver-white, veiy brittle, veiy fine-grained, and refhustoiy in the fire.
(Strom eyer.)

CJLSBSmXp BXOMZBB OV. CdBr. — Cadmium absorbs bromine-vapour at
a heat near redness, forming white fumes of the bromide, which crystallises on cool-
ing, and when stronglv heated sublimes in white nacreous laminse. The hydraUd
bromide^ 2CdBr.HK), obtained by dissolving the oxide or carbonate in hydrobromio
acid, forms white efflorescent needles, which give off half their water at 100^ C, and
the rest, without melting, at 200^.

Bromide of cadmium forms cxystalline compounds with the bromides of potassium,
sodium, and barium. The bariumraalt, CoBr.BaBr -f 2aq., forms large, shining,
colourless crystals, isomorphous with the corresponding chloride. A solution of the
bromides of cadmium and potassium in equivslent proportions, first yields crystals
containing 2CdBr.KBr + ^aq., afterwards crystals of CdBr.KBr; both compounds
resemble the corresponding double chlorides (C. v. Hauer, J. pr. Chem. Ixiv. 477 ;
Ixvii. 169). A solution of equivalent quantities of bromide of cadmium and bromide
of sodium yields the eompoimd 2CdBr.NaBr+f aq. in small, shining, six-sided tables.
(Croft, Chem. Oaz. 1866, p. 121.)

CJLSimtrMv cnOKSDB or. CdCL — A solution of oxide of cadmium in
hydrochloric acid yields a orstalline hydrated chloride, CdCLHK) ; and this when
fuMied yields the anhydrous chloride in the form of a transparent, laminated, pearly
mass, which melts at a heat below redness, and sublimes at a higher temperature in
transparent micaceous laminse.

A solution of chloride of cadmium mixed with excess of ammonia yields, by spon-
taneous evaporation, ammoniochloride of cadmium, NH'.CdCl, or chloride of ccdmam-
monium, NHH)d.Cl— A triammcnio-chloride of cadmium, SNH'.CdCl, is obtained by
exposing dry pulverised chloride of cadmium to the action of gaseous ammonia. It
gives off I of its ammonia when exposed to the air, and is converted into the preceding
compound. ^Croft, Pha Mag. [3] xxi« 866.)

Ctiloride of cadmium forms crystalline compounds with Uie chlorides of many other
metals. These compounds, which have been particularly studied by C. v. Hauer
(J. pr. Chem. bdv. 477 ; Ixvii. 169; Jahresber. d. Chem. 1866, p. 392; 1866, p. 394;
Chem. Soc Qu. J. viii 260), crystallise; by evaporation from mixed solutions of the
component chlorides. The following have been obtained :

The ammonium-salt, NH^Cl.CdCl + }aq., crystallises in slender needles ; the mother-
liquor yields by spontaneous evaporation, transparent shining rhombohedrons of
2NH*CLCda

Potassium-salts. KC1.2CdCl + |aq. separates, by spontaneous or by more rapid
evaporation, from a solution of 1 — 2 at. chloride of potassium to 1 at chloride of cad-
mium, in fine silky needles, which give off their water at 100^ C, and at a higher
temperature melt and give off part of their chlorine. The mother-liquor, or a solution
of at least 3 at chbride of potassium to 1 at chloride of cadmium, yields by spon*

704 CADMIUM: DETECTION.

taneous evaporatioiif the salt 2KCLCdCl, in laige limpid crystals, somewiiat leas (f)
soluble than the preceding.

8odium-ealt NaCLCdCl + }an. (air-dried.) — Small, torbid^ wateiy crystals, wluch
give off 1 at. water at 100 C, and the remainder at 150* — 160^.

Bariumrsalt BaCl.CdGl + 2 aq. — Separates from a solution of eqairalent qosntlties
of the two chlorides, in laige shining crystals, which are permanent in the air, lose
half their water at 100^ C, the rest at 160°, and at a red heat gire off part of tkdr
chlorine, and melt to a colourless liquid, which does not OTstalliae. Aooording to
Bammelsberg's determination, the crystals are monodinic, the obliquely inclined axes
making an angle of 76° 45'. Ratio of the dinodiagonal, orthodiagonal, and prineiul
axi8 = 0-8405: 1 : 0-6128. Observed faces, ooP . ooPoo . (ooPoo) . + P.-P.OP.
(2PaD). Inclination of fiices, 00 P: oo P oo = 140° 60' ; ooP : OP^IOIOC; OP: +P-
137° 40'.

Strontium-aalt Sr01.2CdCl + |aq. — Crystallises from a solution of 1 to 2 at chlo-
ride of cadmium and 1 at. chloride of strontium in transparent, oolourless, aeaminated
crystals.

CalciunusalU. — ^A solution of 3 at. chloride of calcium to 4 at chloride of eadminm
deposits the salt CaC1.2CdCl-i-|aq. in deliquescent bevelled prisms, armnged in
stellate groups. A hot concentrated solution of 2 at chloride of cadmium and 1 at.
chloride of (»lcium deposits, on cooling, large deliquesoent crystals of the salt 2GaCl
Cda + aq.

MagnetiumrMolU. — A solution of 1 to 2 at chloride of cadmium to 1 at chloride of
magnesium yields MgC1.2CdCl + 6 aq. in large transparent crystals. From a solution of
2 at chloride of magnesium to 1 at chloride of cadmium, the salt 2MgCLCdClf 12a^
separates in deliquescent tabular crystals.

Manganue^saU, MnCL6CdCl 1 6aq. — Grystallisee from a solution of 2 at chloride
of cadmium and 1 at chloride of manganese, in pale rose-red or colourless prisma.

Iron-salt. FeC1.2CdCl + 6aq. — Crystallises from a solution of equivalent qaan-
tities of the two chlorides, in colourless prisma, which soon turn green and yellov by
exposure to the air.

Cobalt-soft. CoC1.2CdCl + 6 aq. — Somewhat deliquescent prisms, of the coloar of
chloride of cobalt

Nickd-sdts. NiCL2CdCl + 6 aq. crystallises by spontaneous evaporation from a so-
lution containing the two salts in the required proportions, in dark green prisms ; and
the mother-liquor, or the original solution, if it contains a slight excess of chloride of
nickel, yields 2NiC1.0dCl-r 6aq. in large, dark green, rhoibbic prisms.

Copper-salt. CuCl.CdCl ■¥ 2aq. — Crystallises from a solution containing equivalent
Quantities, in slender shining prisms, grouped in tufts, green when moist, bine vhen
ory.

Chloride of cadmium forms double salts with the hydrochlorates of many oiganic
bases. Greville Williams (Chem. Gaz. 1866, 460) obtained the qmnoUnMeit,
C*H'N.HCL2CdCl, as a hard crystalline mass ; and other compounds have oeen obtained
by J. Galletly (Ed. N. PhiL J. iv. 94), viz. :

CinchorUne-salt C»H"N«O.HCLCdCl + i aq.

Morphine-salts. C"H"N0«.HCL7Cda -f- 2 aq., and C"H»N0*.Ha2CdCl+|aq.

Narcotine-salt. Semi-crystnlline, sparingly soluble mass.

Nicotine-salt. C"H> W.2HC1. 6CdCL CrystaUisable.

Lutidimsalt. C^H'N.HCLSCdCl Very soluble feathery crystals.

Piperine-salt. C«*H*»N«0».2HC1.9CdCl + 3 aq. Straw-yellow needles.

Strychnine-salt. C»"H«N«0*.HCLCdCL Sparingly soluble in water.

Toluidine-salt. 2(C'H'N.HCl).3CdCl + aq. Very soluble scaler

OJLBMZVM, naracTzow amb bstzmatzov or. l. BIokv^ Be-

actions. — All cadmium-compounds, when heated on charcoal in the inner blowiHpe
flame with carbonate of sodium or cyanide of potassium, give a brown incmstatioD
of cadmic oxide. A little cadmium, in presence of zinc, may be detected by beating
the mixture with carbonate of sodium for an instant in the inner flame, when a slight
incrustation of cadmic oxide will be formed. Much longer heating is required for the
formation of zinc-oxide. With borax and musrocosmic Milt, cadmic oxide forms a bead
which is yellowish while hot colourless when cooL

2. Liquid Reactions. — Zinc immersed in a solution of a cadmic salt throvs down
metallic cadmium in dendrites. 8ulpht/dric acid gaSy passed throngb cadmium-
solutions, even when a large excess of acid is present, precipitates the whole of the
cadmium in the form of sulphide, which has a lemon-yellow colour at first bnt afte^
wards becomes orange-yellow. A similar effect is produced by alkaline sulpki/draies,
the precipitate being insoluble in excess. The hydrated sulphides of manganese, iron,
eobiutk and nickel, when recently precipitated, likewise throw down sulphide of cad-

J?.ADMIUM: ESTIMATION ^IODIDE. ?05

miiim from cadmie salts (Anthon, J. pr. Chem. x. 353). Cauatio alXuUis throw down
white hydrate of cadmium, Tory easily soluble in a slight excess of ammonia, but in-
soluble in potash or soda. Sulphydric acid likewise precipitates sulphide of cadmixun
from the solution in excess of ammonia. The neiUral and acid carbonates of ammo-
nium^ potasaium, and sodium throw down white carbonate of cadmium, insoluble in
excess of the alkaline carbonates. If the salt contains a large quantity of free add,
the precipitate dissolves in excess of carbonate of ammonia, but not otherwise (S tro-
meyer). PhotjthaU of sodium throws down white phosphate of cadmium. Oxalic
add and alkaline oxalates precipitate white oxalate of cadmium, insoluble in alkaline
oxal&tes, but easily soluble in ammonia. The white precipitate produced by ferro'
ctfanide of potassium^ and the yellow precipitate produced by the fenicyanide, are
soluble in nydrochloric add. The addition of hyposulphite of sodium and hydro-
chloric add does not produce a predpitate of sulphide of cadmium ; neither is any
predpitate produced by chromic add, succinic add, alkaline benzoates, or tincture of

Cadmium is the only metal which forms a yellow sulphide insoluble in sulphide of
ammonium.

3. Quantitative Estimation, — Cadmium is best precipitated firom its solutions
by carbonate of sodium ; it is thereby obtiuned as a carbonate^ which, by ignition, yields
the brown oxide containing 87'6 per cent of the metaL

4. Separation from other Elements. — From the metals of the second and fourth
groups, and from all non-metallic elements except selenium and tellurium, cadmium may
be separated hj sulphuretted hydrogen ; from selenium^ tellurium^ and the metals of
Group 1, Subdivision a (p. 217), by the insolubility^ of its sulphide in sulphide of
ammonium. The sulphide is tlien dissolved by nitric add, and the cadmium preci-
pitated bv carbonate of sodium, as above.

From bismuth, lead, and mercury^ cadmium may be separated by the solubility of its
oxide in ammonia, or of its cyanide in cyanide of potassium : from lead also by sul-
phuric add, and from mercury by precipitating the latter in the metallic state by proto-
chloride of tin. From palladium^ it is also separated by the solubility of its cyanide
in cyanide of potassium ; from silver, by precipitating that metal as chloride. From
copper, cadmium is separated by carbonate of ammonium, an exceai of which re-
dusolves the copper and not the cadmium : or better, by treating the solution of the
two metals witn excess of cyanide of potassium, which predpitates and redissolves
them both, and passing sulphuretted hydrogen through tne liquid, whereby the cad-
mium is predpitated, while the copper remains dissolved. (See Copfeb.)

6. Atomic Weight of Cadmium^ — Stromeyer found that 114*352 pts. protoxide
of cadmium, Cd^O, yidded 14-352 0; whence 14*352 : 100 » 16 : Cd*; and Cd »

- — » 55*7. Dumas (Ann. Ch. Fharm. cxiii. 27)t ftom. the mean of six

experiments on the quantitv of nitrate of silver required to precipitate the chlorine
from cUoride of cadmium, found for the atomic weight of cadmium, numbers varying
from 55*89 to 56*38. He regards 56 as very near to the true value.

OADBKZinMEf F&VOXXBB OV, CdF, is deposited from the aqueous solution on
evaporation, in white, indistinctly crystalline crusts. It dissolves sparingly in pure
water, more readily in aqueous hydrofluoric add. (Berzelius.)

CABmuXf ZOBZna or. Cdl. — ^Prepared either in the dry way, or bjr digest-
ing cadmium with iodine and water. Crystallises in large, transparent, six-sided
tables, which are not altered by exposure to the air. It melts easily, and solidifies
again in the crystalline form ; gives off iodine at a higher temperature. Dissolves
readily in water and alcohol, ana crystallises unchanged from the solutions. Sulphy-
dric add slowly precipitates sulphide of cadmium from the aqueous solution.

Two ammonuModides of cadmium are known, viz. NH'.Cdl, which is deposited in
small crystals from a solution of iodide of cadmium in hot aqueous ammonia ; and
SNH'.Cdl, which is a white powder produced bv gently heating iodide of cadmium in
ammonia-gas. (Rammelsberg, Fogg. Ann. advui 153.)

Iodide of Cadmium and Potassium, CdLKI + aq. crystallises in conliised octa-
hedrons from a solution of the two iodides in equivalent proportions. In like manner
are obtained : NH^LCdl + aq., apparently isomorphous with the potasdum-salt ;
Nal.Cdl + 3aq. in deliquescent pnsms; "iBaLCdl + j aq., also deliquescent; and
SrLCdl + 4aq. in large crystfds, which deliquesce in moist, and efSoresce in dry air.
(Croft, Chem. 0a2. 1856, p. 121.)

CABBSZVMf JiXl*JU3>a OF. (?) When an electric current is passed through a
solution of sal-ammoniac, the positive pole being formed of cadmium, and the negative
pole of platinum, the latter becomes covered with a spongy, lead-grey mass, which,
after washing and drying, has a density of 4*8 ; 5 grains of it gave off when heated,

Vol. L Z Z

706 CADMIUM: OXIDE — CADMIUM-ETHHi.

0*18 to 0*26 cftb. in. of nitrogen gas free from hjdiogen, and left a ydlowish-gna
residue^ containing globules of c^miam. (Grove, AiL Mag. [3] xix. 99.)

OAAMIWp oaOCDas IMP« Gadminm forma two oxides, tiz. a protoxide, Gd*0,
and A anbozide, CdH). The protoxide diasolyea in adds without eromtion or abtoip-
tion of oxygen, and fonna salts of eofrmspondiDg composition : e. g. the sulphate, Cd^*,
the nitnite CdNO*, &c. These are indeed the onlj salts of cadmiom ; the saboxidc
when treated with anda, yields metallic cadmium and a protosalt

Suboxide of Cadmium, CdK), is obtained by heating the oxalate to about the melt-
ing point of lead. It is a green powder, resemblinff oxide of chromium, and is lenlTcd
by heat or by acids, into metallic eadminm and the protoxide. It does not boverer
yield metalUe eadminm when treated with mercuy : nence it appearB to be a definite
compound, and not a mere mixture of the metal with the motoxiae.

Protoxide of Cadmium, or Cadmic Oxide, Od>0, or GfO.— Cadmium, heated in
the air, takes fire and is eonrerted into protoxide. The same compound is fbnned
when Tapour of cadmium and aqueous yapour are passed together throng a red-hot
tube ; but it is most easily prepared by igniting the hydrate, carbonate, or nitnte.
It raries in colour from brown-yellow to blackish, according to the mode of preptration.
By boiling <*«iimiiiin for some time in a long-nedced flask, the oxide may be obtained
in purple ciystala. Its specific grayity is 6*9502. It is quite fixed in the fire, and
does not melt at the strongest white hMl It is easily reduced by eharooal before the
blowpipe, and emits Tapours of metallic cadmium, which is immediatelT reoxidised,
and forms a red or brown deposit on the charcoal (p. 703). It is insohible in vater,
but unites with it, forming a Wdrate.

Hydrate of Cadmium, Cdm>, is precipitated by potash frvnn dHute sohitioBB of
cadmic salts ; it may be obtained in indistinctly crystiJUne warty groups, by the action
of aqueous ammonia on metallic cadmium in contact with iron or copper. It is vhite,
absorbs carbonic acid from the air, is insoluble in the fixed alkalis, dusolres readiij in
caustic ammonia, but not in carbonate of ammonia. It dissolTCS easily in solphnzie^
nitric, hydrochloric, and acetic add.

OJLUMIIFI^ VSOSVHDB of. Orej, with faint metallic lustre ; Teir brittle;
difficult to fuse. Bums in the air with a bright fiame, produdng cadmic phosphate.
Hydrochloric add dissolves it, with erolution of phosphoretted hydrogen.

CABMXVaCt smbrama of. Gd^ or C^^.— This compound oeeon in the
form of Greenoekitf, and is prepared as a pigment known by the name of jatmebnllML
It is formed with difficulty by fusing cadmium with sulphur, — more readily by igniting
cadmic oxide with sulphur ; predpitated in yellow fiakes when sulphydric add or an
alkaline sulphydrate is brougnt in contact with a cadmium-salt. Tbe natire anlphide
crystallises in double six-sided pyramids and other forms of the hexagonal systni,
with cleayage parallel to the terminal and lateral edges of a six-dded prism. SoeaSt
grsTity 4*8 (Brooke), 4*908 (Breithaupt). Hardness equal to that of ca^ar.
Of diamond lustre, semi-transparent, honey-yellow ; yields an orange-yellow or a hnck-
red powder ; becomes carmine-red when heated. Decrepitates when nested somewfaat
strongly (Brooke, Breithaupt). The artifidal sulphide, in the predpitated state,
is an orange-yellow powder, which, when heated to redness, becomes first brovni^
and then carmine-red. It melts at an incipient white heat, and sob'dfies on cool-
ing, in transparent, lemon-yellow, micaceous lamime. It is not Toktile at anj
temperature (Stromeyer). Specific grarity of the fused artificial solphide, ifOL
(Earsten.) ^ ^

In dilute hydrochloric acid it dissolTes with difficulty, eren when the add is heated;
but if the add be strong, the sulphide dissolTes with ease, even at ordinaiy tempe-
ratures, with yiolent evolution of sulphuretted hydrogoi, and without wepottitn of
sulphur. At a red heat, it slightly decomposes rapour of water; at a white h«^
oxide of cadmium is formed (Begnault). It dissolyes in nitric add, with erohitua
of sulphuretted hydrogen and separation of sulphur. Very soluble in ammonia.

CSABMIUBB-JIVU I Jb. Cadmium appears to form with ethyl a oomponod ana-
logous to zinc-ethyl ; but it has not yet lien obtained in the pure state. ^*"yJ^
(Chem. Soc. Qu. J. ix. 193), by heating cadmium-foil with half its weight of iodide rf
ethyl dissolved in an equal volume of ether in a sealed tube, obtained a liquid wdiot
passed over in fractional distillation between 180® and 220° C gave ofiT first white and
then brown vapours on exposure to the air, and at length took fire, emitting a hrown
smoke. It smelt like zinc-ethyl, and was decomposed by water, with eiFerr««noB
and formation of a white precipitate. It contain«l 36*8 per cent cadmium, whereea

Ixvii. 169.)

CESIUM — C AFFEINR 707

Symbol Ob. At(mie VBeight - 124.— An alkali-metal, the chloride of
which has lately been diacoyered by Bunsen and Kirchhoff, in the mother-liquors of
r«rtain saline-waten in Oermany. Its compounds giTe a spectrum distinguished by
two blue lines, one rather ^t at about the middle of the blue space of the normal
spectrum, and tiie other Auch brighter, situated more towards the violet end. It was
by this peculiar spectni^i that the metal was disooyered (page 214).*

CO AC^D. See CAnvrAmnc Acid.

C"H"N*0« or a^H^'N^O*, (Gm. xiii. 223 ; Gerh.
i 642.) — Caffe^e was discoyered in coffee by Runge, in the year 1820 (Materialien
mr Phytologi< 1821, i. 146^. Oudry (Mag. Pharm. zix. 49), in 1827, found in tea a
crystalline subtance, which he called theine, supposing it to be a distinct compound ;
but Jobst (Ann. Ch. Pharm. xxy. 63) and Mulder (Pogg. Ann. zliii. 160), in 1838,
showed that it was identical with caffeine. Martins, in 1840 (Ann. Ch. Pharm.
zxxvL 93), discovered the same substance in guar an a^ the dried pulp of Pauiinia tor'
bUis;uid Stenhouse, in 1848 (PhiL Mag. [3] xxiii.426), obtain^ it from Paraguay
tea, the leaves and twigs of Hex Paraguayensis, The same chemist has shown (PhiL
Mag. [4] viL 21) that it ejdsts in the leaves as well as in the berries of the coffee-
plant. The exact composition of caffeine was first demonstrated in 1832 by Pfaff and
Lieb ig (Ann. Ch. Pharm. L 17). Its combinations and reactions have been especially
studied by Stenhouse (loc^ eU, ; also Ann. Ch. Pharm. xlv. 366 ; zlvi. 227), Nichol-
son (Chem. Soc Qu. J. iii. 321), P^ligot (Ann. Ch. Phvs. [3] xi. 128) and Rochleder
(Ann. Ch. Pharm. Izzi 1 ; IzxiiL 56 and 123). Its alkalme nature was first demon-
strated by Herzog. (Ann. Ch. Pharm. zzvi. 344 ; zxix. 171.)

Preparation, a. From Tea or Coffee. — 1. The mode ofextraction generally adopted is
to treat tea or coffee with boiling water and mix the infusion with subacetate of lead to
precipitate the tannin. P^ligot adds subacetate of lead in excess, then ammonia.
The mixture is boiled for some time, the lead-predpitate carefdlly washed on a filter
with boiling water, the filtrate freed from excess of lead by sulphuretted hydrogen, and
after a second filtration, evaporated at a gentle heat^ On cooling, it yields an abun-
dant crystallisation of nearly pure caffeine, and an additional quantity may be ob-
tained uy concentrating the mother-liquor and leaving it to ciystallise.— 2. Caffeine
may also be obtained by saturating the fr«e acid contfuned in inftision of tea or coffee
with carbonate of potassium ; treating the liquor with with infusion of gaU-nuts ; mix-
ing the precipitate with dry hydrate of lime ; exhausting the mixture with alcohol ; ex-
pcfiing the alcohol from the filtrate by distillation ; and dissolving the residue in boil-
ing water or boiling ether (Bobiquet and Boutron, J. Pharm. xxiii. 108). — 3. Five
pts. of ground coffee are mixed with 2 pts. of slaked lime, and the mixture is ex-
hausted with alcohol in a displacement apparatus. The extract is then dried, pul-
verised, and again treated wim alcohol ; the alcohol separated from the extracts by
distillation ; the fat oil which floats on the surface is removed ; the watery liquid is eva-
porated to the crystallising point ; and the crystals of caffeine are pressed and deco-
lorised by animal charcoal : 50 kilogrammes c^ coffee thus treated yielded more than
250 grammes of caffeine (Yersmann, Arch. Pharm. [2] Ixviii 148). — 4. Ground
coii^ is digested for a week with commercial benzene, which takes up caffeine and oil
of coffee. Both remain behind when the benzene is distilled off, and may be separated
by hot water, which dissolves the caffeine and leaves it in large ciystals when evapo-
rated. The oil may also be dissolved out by ether, which leaves the caffeine undis-
solved (Yogel, Chem. Centralb. 1858, p. 367). — 5. Payen exhausts coffee with ether,
^ then washes it thoroughly with alcohol of 60 per cent., concentrates the solutions to a
slightly syrupy consistence, and mixes them with three times their volume of 85 per
cent, alcohol, whereupon the liquid separates into two layers, the lower being viscid
and the upper fluid. The latter, which contains the greater part of the caffeine, is
decanted, and freed from the greater part of the alcohol by distillation ; and the syrupy
residue is mixed with one-fourth of its bulk of alcohol at 90^ C, and left to itself in a
cool place : it then deposits crystals, which are recrystaUised from alcohol. They con-
sist, according to Paven, of caffetannate (chlorogenate), of caffeine and potassium, and
when submitted to cuy distillation', yield a sublimate of caffeine (Ann. Ch. Phys. [3]
xxvi. 108). — 6. Caffeine or theine being volatile, may also be prepared by sublimation.
For this purpose, waste useless tea is ^adually heated in a sublimation apparatus, like
that used for preparinff benzoic acid, but not so strongly as to decompose the theine.
Part of the sublimate is quite pure ; the rest may be purified by reciystallisation from
water. (Heiynsius, J. pr. Chem. xlix. 317.)

According to the results of an extensive series of experiments made by Graham,
Stenhoussp and Campbell (Chem. Soc. Qu. J. ix. 33), coffee contains from 0*8 to

* Ses Appbndiz to thii folnmsi
z z 2

708 CAFFEINE.

1 per cent, of caffeine ; tea about 2 per cent. Stenhouse (Ann. Gfa.Pliann.lxxxix.246)
obtained from a sample of black tea from Kimaon on the l^malaya, 1-97 per cent tibeine,
and from another sample of good black tea 2-13 per cent According to Piligot
(Ann. Oh. Phys. [3] xi. 68), Hyson tea contains from 22 to 3*4 per cent, ud gun-
powder tea fr^om 2*2 to 4*1 per cent of theine. According to Bobiqnet and Boatron
{loe. cit) Martinique coffee yields 3*6 per cent, Mocha coffee 2*06, and Cayenne eofiee

2 per cent, of caffeine.

6. From Guarana, — Ghiarana mixed with <^ of its weight of qnick lime is repeatcdlj
boiled with alcohol of 33^ Beck ; the filtrate is eTWoratod a little ; the greenish &tty
oil which separates on cooling is removed ; the residoal alcoholic liquid completely era-
porated ; and the dry residue is heated : caffeine then sublimes, at &st yellowisli-wbite,
afterwards quite white. — % Twenty-four grammes of guarana powder are boiled vith
a quart of water ; the cold solution is precipitated with basic acetate of lead; the bnlkj
brownish-red precipitate filtered off, and repeatedly digested with hot wat^; and the
lead is separated from the filtrate by sulphuretted hydrogen. The Hqnid aeparated
from the sulphide of lead is evaporated in the water^bath to dryness ; the residue dis-
flolved in a httle boiling alcohol, filtered, and allowed to crystallise ; and the oystds
thus obtained are purified by pressing and reciystallisation. Guarana contains aboot
6 per cent of caffeine. (S ten house.)

c. From Paraguay Tea. — The filtered decoction is precipitated with nentnl acetate of
lead and the filtoite with basic acetate (or it is boiled witiulitharge), and the liquid de-
canted from the precipitate is evaporated to dryness, a tough, dark brown, bygrosoopie
mass then remaining. From this residue, caffeine may 1m obtained, either hj snUi-
mation, or by reducing it to powder, mixing it with sand, and treating it with ether.
After distilling off the ether, feebly coloured caffeine crystallises, and may be pnrificd
by repeated crystallisation. The product amounts to 0*13 per cent of the Faragoaj
tea. (S ten house.)

[For a full account of the methods of preparing caffeine, see Gmelin*8 Handbook,
loc. eit.]

Properties, — Caffeine crystallises from water in slender needles, having the aspett
of white silk, and containing 8*4 per cent water of ciystallisation (C*H'*N*O*+H'0),
which is not given off completely at 160^ C. (M u 1 d e r). Specific gravity of the ajttals
1*23 at 190 C. (Pfaff). It has a slightly bitter taate, and grates between the teeth.
Melts at 178^, and sublimes completely at 185° in capillary and feathery needles
(Mulder). It is sparingly soluble in cold water ana alcohol, still less in ether.
Boiling water dissolves it more freely, and the solution solidifies in a pulp on oooling.
The crystals which separate from ether and alcohol are anhydrous.

J)eeompo»iiiona. — 1. Caffeine, when quickly and strongly heated, soffera partial de-
composition, giving off vapours which have the odour of methylamine.— 2. SdongfH^-
phuric acid decomposes it after continued heating. — 3. When chlorine is passed into a
thick magma of caffeine and water, the crystals gradually disappear, and a mixture of
several substances is obtained, varying in composition according to the duration of the
action. With a comparatively small quantity of chlorine, the products are amalie
acid, C*H'N*0\ methylamine and chloride of cyanogen, together with dilorocaffeine,
CH*C1N*0*. The formation of the three first-mentioned products is r^nsented by
the equation:

C«H»»N«0« + 2HK) + a* « C^«NK)* + CH»N + CNa + ZEa

The resulting liquid heated in the water-bath gives off hydrochloric add, and a gas
smelling like chloride of cyanogen, and granular crystals of amalie acid separate, spe-
ceeded (if too much chlorine has not been passed through the liquid) by chlonKaffeine
in light fiocks and crusts. If the action of the chlorine be prolonged, the oompoand
C*H«N«0», called nitrotheine by Stenhouse, cholestrophane by Rochleder, and dimOkyl-
parabanio aeid [C\CH*)«N«0»J by Gerhardt, is produced:

O»H«N'0« + a« + HK) « C»H«N*0« + C0« + 2Ha

Amalie add. Nitrotheioe.

4. Caffeine boiled with hydrochloric acid and chlorate of potassium yields alloxan or
a similar body, the aqueous solution of which colours the skin red and imparts to it
a peculiar odour. The solution gives with ammonia the colour of murexid, and vjth
alkalis and ferrous salts the colour of indigo. — 6. Strong nitric add boiled with
caffeine gives off nitrous fumes, and forms a yellow liquid, which assumes the purple
colour of murexid on adding a drop of ammonia (this reaction furnishes a tat far
caffeine). If the ebullition be continued, the liquid becomes colourless, no longer ex-
hibits the purple colour with ammonia, and yielos by evaporation crystals of dimethyl-
parabanic acid (nitrotheine), floating in a mother-liquor containing a saltofmetbjl-
amine. — 6. Caffeine boiled with very stroBg potcuh-ley evolves a considerable quantity
of methylamine. — 7. With soda-lime it gives off ammonia, forms carbonate of sodinm.

CAFFEONE — GAFFETANNIC ACID. 709

cari)onate of cidciam, and a large quantity of cyanide of sodium. This reaction dis-
tinguishes caffeine from piperine, morphine, quinine, and cinchonine, which do not
form cyanide of sodium when similarly treated. (Rochleder.)

Compounds of Caffeine, — Caffeine is a weak base : it dissolves in acids, forming
salts which hare an acid reaction, and are for the most part decomposed by erapora-
tion, caffeine free from acid being deposited.

Hydrochlorate of Caffeine^ C"H^^0*.HC1, is obtained in crystals by dissolving
caffeine in very strong hydrochloric acid, not diluted either with water or with alcohol,
and concentrating bj gentle evaporation. If either water or alcohol bo added, nothing
bnt caffeine aystallises out. The salt forms large, transparent, efflorescent crystals, be-
longing to the trimetric system, ooP . j^ oo . oo 1* oo. Inclination of the faces, ooP :
00 P - 118° 30' : too : oeI>oo « 116® 30'.

Chloroaurate of caffeine, C«H»«N*0».HCl.AuCl«, crystallises from alcohol in orange-
eolonred needles (Nicholson). The chloromercurate, C*H"N*0*.2HgCl, obtained by
mining an alcoholic solution of caffeine with excess of mercuric chloride, forms needles
resembling caffeine, soluble in water, hydrochloric acid, alcohol, and oxalie acid, nearly
inaolable in ether. The cyanontercurate, CH'*N^O'.2HgOy, prepared in like manner
forms prisms belonging to the dimetric system, sparingly soluble in cold water and
alcohoL The ehioroplatinaCey C*H»N^O^HClPtClS forms small distinct orange-yellow
crystala, sparingly soluble in water, alcohol, and ether. With chloride of paUadium^
hydrochbrate of caffeine forms a beautiful brown precipitate, and the filtered liquid
deposits yellow scales of another compound, not unuke iodide of lead.

A solution of caffeine does not precipitate sul^htUe of eoppert protochloride of tin^
acetate oflead^ or mercuroua stdpkate, BoUed with sesqutcMoride of iron, it forms, on '
cooling, a brown-red precipitate, perfectly soluble in water, and probabh' consisting of
a doable salt similar to the preceding. With nitrate of silver, caffeine forms the com-
pound AgNO*.C*H^*N'0^ which separates on mixing concentrated solutions of caffeine
and nitrate of silver, in white crystalline hemispheres, adhering firmly to the sides of
tiie vesaeL It is sparingly soluble in cold, more readily in hot water and alcohol ; deto-
nates when heated.

Sulphate of Caffeine is difficult to crystallise, and is easily decomposed by wat«r.

Tannate of Caffeine is obtained as a white precipitate when an aqueous solution of
caffeine is added in excess to aqueous tannic acid. It contains 41*9 per cent, caffeine
and 68*1 tannic add (Mulder). An infusion of tea, by its tannin, also precipitates a
solution of caffeine.

The aromatic principle of coffee. It may be isolated by distilling
5 or 6 lbs. of roasted coffee with water, agitating the aoueous distillate with ether,
and afterwards evaporating the ether. It is a brown oil, heavier than water, slightly
soluble in boiling water. An almost imponderable quantity of it is sufficient to aro-
matise more than a quart of water. (Pelouze et Fr^my, Traits, ir. 449.)

CAnVTAirVZC ACZB. CaffeicAcid. Chlorogenic Acid. C^R'^O" ? (Pfaff,
1830, Scher. Ixi. 487. — Kochleder, Ann. Ch. Pharm. lix. 300; Ixiii 193 ; Ixvi. 35 ;
IxxxiL 196. — Liebich, t6i<f. Ixxi. 97. — Stenhouse,t^'<2.1xxxiiL 244. — Payen, Ann.
Ch. Phys. [3] xxvi. 108.--Gerh. Traits, iii. 886.)— This acid exists in coffee berries
to the amount of 3 to 5 per cent, as a calcium- and magnesium^salt, and, according to
Payen, as a doable salt of caffeine and potassium. According to Kochleder, it is also
found in Paraguay tea. It is prepared by mixing an alcoholic infusion of coffee or
Paraguay tea witn water to separate the fatty matter ; then boiling the liquid, adding
acetate of lead, decomposing tbe precipitate with sulphuretted hydrogen, and evapo-
rating the filtered liquid. It forms a yellowish brittle mass, which may with difficulty
be obtained in colourless, mammellated, cxystalline groups. It dissolves easily in water,
lees in alcohol ; has an astringent taste, and reddens litmus strongly. Melts when
heated, then chars, and gires off the odour of roasted coffee. By dry distillation it
yields water and a thick oil, which solidifies on cooling, and consists of oxyphenic acid
(Rochleder). Strong sulphuric acid dissolves it with the aid of heat, forming a blood-
ied liquid. Distilled with peroxide of manganese and sulphuric acid, it yields quinone
(Stenhouse). It dissolves with yellow colour in potash and in ammonia. The am-
moniacal solution in contact with the air quickly turns green, producing ifiridic add,
0*H»H)»(?) (Rochleder.)

Caffetannic acid colours ferric salts green. It does not precipitate ferrous salts, but,
on adding ammonia, a nearly black precipitate is obtained. It does not precipitate
tartar-emetic or gelatin, but precipitates quinine and cinchonine. It reduces nitrate of
silver in specular form if the liquid is heated.

The formula of caffetannic acid is not definitely fixed. Rochleder first supposed it
to be C**H'*0*, but afterwards gave the prefert»nce to C'»H'*0'. Gerhardt (Traits,
iii 886) suggested C^H^", according to which caffetannic acid would be a homologuo

sz 3

710 CAINCIC ACID - CAJEPUT.

of gallotannic acid, C*'H*'0", differing from it by 8CH*. Pfaff soppoees it ocmtaim tva
•cidfl, caffeic and caffetannic ; but £(^hleder fbund only one, viz. (affetannie acid, with
traces of citric acid.

The caffe tannatesBxe bat little known. The|MtaMtt(m-flalt is amoipbons, soluble
in water, insoluble in alcohol, and turns brown from oxidation on exposure to the air.
The barium- and (»i/ctum-salts are yellow, and quickly turn green on ezposuie to the
air. The ^ad^salt is a white precipitate of very rariable composition.

The caffetannate of caffdne and potauium^ prepared as already described (p. 706),
forms spheroidal eroups of crystals, which become electric by firiction. Th^ are rvy
soluble in water, less soluble in aqueous alcohol, nearly insoluble in absolute akohoL
The aqueous solution turns brown when exposed to the air.^ They are deoompoeedbT
dry distillation, swelling up strongly and yielding a sublimate of caffeine. Gentlj
heated with potash, they assume a red or orange colour. Heated with strons solphnne
acid, they yield a liquid of deep Tiolet colour, with a bronze peUide on the su&x.
Nitric acid colours them orange-yellow.

CAXVCSO AOIB. C*«H*K)' (?) (Francois, Pelletier, and Cayentou, 1880,
J. Pharm. xri 466.— Liebig, Ann. Gh. Phm [2] xlvii 185.— Boehleder lod
Hlasiwetz, Ann. Ch. Pharm. Ixxvi 238. — Gerh. l^it^ iii. 746.)— Found in the not
of cainca {Chiococoa angwfu^a^ Martius), a rubiaoeous plant growing in Brad], and
used as a remedy against the bites of serpents ; also in tiie root of GJUoooom raeNioM(ZfkX
a plant much used in the Antilles for tne cure of syphilis and rheumatisaL

It is prepared : 1. By exhausting calnea root with alcohol, conoentratinff the alco-
holic extract, mixing it with water, and adding milk of lime to the filtered liquid tiH
it loses its bitterness. An insoluble basic caincate of calcium is thus^ produced, vhieh
is decomposed by a hot alcoholic solution of oxalic add. The filtered sohition, wheo
evaporated, yields caincic acid in shining needles (Pelletier and CaTentou).—
2. From the root of Chiococoa racemoaa^ by exhaurting the bazk of that root vith
alcohol ; mixing the solution with neutral acetate of lead, which throws down caffe-
tannate of lead, together with some caincate and phosphate ; then treating the filtrate
with subacetate of lead, which forms a yellow p«cipitat« containing the greater part
of the caincic acid, with only traces of caffetannic add. This predpitate Ixping deooiB'
posed by sulphuretted hydrogen, and the filtrate sufficiently oonoentrated, the eauidc
add is depodted in crystalline flakes, which may be purified by crystallisation from
boiling water containing a little aloohoL

Caincic add is inodorous ; tasteless at first, afterwards veiy bitter ; sparingly sohble
in water and ether, yery soluble in alcohol Beddens litmus perceptibly. The ayrttls
give off 9 per cent, water at 100^ C. (Liebie). When heated it softens, cfaara, aod
yields a crystalline sublimate which is not bitter. Dilute adds and strong alkaliB
conyert it into quinoyatic acid.

The catncates are but little known ; they have a bitter taste. The neutral eameatee
of amT/tonium, potassium^ barium, and calcium are soluble in water, deliquescent, and
uncrystallisable. Lim&> water, added to the solution of neutral caincate of caldnm,
produces a copious precipitate of a bade salt, soluble in boiling alcohol, whence it
separates in white flakes, which are strongly alkaline. The normal Uad-uit,
C"H*'Pb*0' + H'O, is precipitated on mixing strong alcoholic solutions of caude arid
and acetate of lead. There are also basic lead-salts.

CAZXVOORBI BTOXra. Smoky quartz. See QuABn.

CATXyHTv OXZi or. This oil is prepared in India by distilling the lesTcs of
Melaleuca Leucodendron (L.) with water. It was formerly employed to a great extent
in medicine, both internally and extemdly, but is now but little used, and is seldom
met with in a pure or unchanged state, except in the hands of wholesale dmggiEta.
As introduced into Europe, it possesses a light green colour, resembling that of a dilate
solution of chloride of chromium, which is caused by a resinous colouring matter dis-
solved in it in yery small quantity.

The colour of the crude oil is also partly due to copper, the presence of which maj
be accounted for, either by the use of a copper head in the Hiat^Hng i^rparatas of tlu
Hindoos, or by intentional adulteration, resorted to for preserying the green colour of
the oil, which otherwise changes gradually by oxidation to a reddish-brown, the oil
then becoming unsaleable for medicinal purposes. That the oil possesses a greeo colour
of its own is proved by the fact that the colour remains after the complete removal of
the copper by sulphuretted hydrogen.

Oil of cajeput consists mainly of the dihydrate of a hydrocarbon called cajputene,
isomeric with oil of turpentine. Its spedflc gravity is 0*926 at 10® C. On submitting
It to fractional distillation, dihydrate of cajputene, which constitutes about two-thirds
of the crude oil, passes over between 176° and 178° C. ; smaller fractions, pcrh^w pro-
ducts of decomposition, are obtained from 178° to 240° and from 240° to 260^; iM«l

CAJPUTENE. 711

250^ only a small reeidtie ia left, oonaistiiig of carbonaceoua matter mixed with me-
tallic copper. On treating this residue with ether, a green solution is obtained, which,
when eraporated, leaves a green resin, soluble in the portion which boils between 176^
and 178^, and capable of restoring the original colour. (M« Schmidl, Trans. Boj.
8oc Ed. xziL [6] 360 ; Chem. Soc. Qu. J. zit. 63.)

ClAJVUTSn. C*«H>*. (Schmidl, loc,cit.y-ThM compound is obtained, to-
gether with two isomeric hydrocarbons, isocajputene and paracajputene, by
cohobating dihydrate of cigputene with phosphoric anhydride for half an hour, and then
distilling off the liquid, whereupon cigputene passes over at 160^ — 166^ C. ; isocajputene
at 1760— 178**, and paracajputene at 810®— 316«

Ctyputene is pennaaent in the air. It is not affected by ioditie at ordinary tempe-
ratures, but at a higher temperature, hydrogen is evolved and a black liquid is formed.
Bromine acts quicUy on it, producing a dark viscid oiL With ffoaeous kydrochlorio
add, it forms a beautifU violet liquid, but no crystalline compound, even at — 10® C.
A mixture of ordinaiy nitrio and gulphurie o/cids acts upon it with violence, forming a
yellow bitter resin.

Cigpntene is insoluble in alcohol, but dissolves in ether and in oil of turpentine.

Isocajputene, C**H". — Obtained: 1, as abovei — 2, by distilling the dihydrate of
cigputtoe with oil of vitriol It is an oil boiling between 1 76® and 178® C. Its odour is
less agreeable than that of cajputene, and becomes more pungent and aromatic by expo-
sure to the air, the oil at the same time acquiring a yeliow colour. Specific gravity »
0-857 at 16® C. yapom^den8ity of (1) « 4*82 ; of (2) « 4-62.

Iodine, bromine, ga»eou» hydrochloric acid, and a mixture o{ nitric and stdphuric acids,
act upon isoc^JDutene in the same manner as on cajputene. With oil of vitriol, and
with dilute stdpnuric, hydrochloric, or nitric acid (neither of which acts upon c^putene),
it foima dark viscid liquids.

Isoc^putene is insoluble in toaicr and in alcohol, but mixes in all proportions with
ether and with oil of turpentine,

Paracajputene, C^H**, obtained as above mentioned, by distilling dihydrate of
cigputene with anhydrous phosphoric add, passes over between 310® and 316® 0. It is
very viscous, has a lemon-yellow colour, and in certain directions exhibits deep-blue
fluorescence. Vapour-density, by experiment » 7*96 ; by calculation (2 vol) i^ 9*43.
The difference between the experimental and calculated vapour-densities is probably
due to decomposition, taking place at the high temperature required for the deter-
mination.^

Paracajputene oxidises rapidly in contact with the air, acquiring a red colour and
resinous consistence. A mixture of nitric and sulphuric acids does not act so violently
on it as on cajputene and isoo^'putene. With hydrochloric acid gas, it forms a dark
visdd liquid, which does not yield crystals, even at — 10® C. It is insoluble in water,
alcohol, and oU of turpentine, soluble in ether.

BBomm OF CAJPUTXifB, C"H*«Br*.— Obtained by the action of bromine on oil of
cigeput When dry bromine is dropped into the rectified oil, a very brisk action takes
plac», and the sides of the vessel become covered with yellow needles, which however
soon disappear ; but if the addition of the bromine be continued till the reaction almost
ceases, a dark, thick, viscous oil is formed, which, after several weeks, deposits a
granular substance. By boiling the mixture with alcohol, the granular substance is
extracted ; a heavy oil is left behind ; and the alcoholic solution, on cooling, deposits
bromide of o^putene as a soft crystalline substance having a fatty lustre and much
resembling cholesterin.

Bromide of cajputene melts at 60® C. and solidifies again at 32®. By diy distillation,
it yields a liquid which crystallises again in the cooler parts of the retort. It is not
altered by boilixig with aqueous potash. It dissolves in ether and in boiling alcohol.

Bectified oil ofcajeput shaken up with bromine-water, forms a red resin, from which
a solid substance separates in small white prisms, extremely deliquescent and rapidly
decomposing.

Another crystallised bromine-compound (probably a hydrobromate analogous to the
hydriodate) is formed in the same manner as that compound (p. 713).

Chloridb of Cajfuteitb, C"H"C1*, is produced by the action of nascent chlorine
on the dihydrate (rectified cajeput oil). When the portion of the oil distilling between
175® and 178® C. is mixed with very dilute nitric add, and hydrochloric acid gas is
passed into the liquid, a violent action takes place in a few minutes, chlorine and
nitrous gas being evolved ; and, if the passage of the gas be continued, chloride of
cajputene ultimately sinks to the bottom, as a limpid brown oil, which may be freed
firom adhering nitric and nitrons add by distillation over strong potash-ley. It has a
fragrant odour, and may be kept without alteration for any length of time, but is de-

sz 4

712 CAJPUTENE.

composed by distillation. Boiled -witli nitrate of silver, it detonates in a pecoliar
manner, and forms chloride of silyer.

Hydrates of Cajputene. Hemi-hydrate, C*H»'0=(C"H»^'.HK) (or perhaps
monohydrate of paracajputene^ C**H".H*0.) — Obtained by Uie action of oil of vitriol on
oil of cajeput. When the crude oil is raised to the boiling-point in a deep open Tessel,
and oil of vitriol continuously dropped into it, violent ebullition takes pl»», aooom-
panied, after a while, by a peculiar crackling sound. As soon as this is observed, the
flame must be lowered and the acid very cautiously added, till the liquid soddesly
assumes a dark colour, extending in an instant from the surface throughout the vhole
depth. The vessel must then be immediately removed from the fire, otherwise farther
decomposition will take place, attended with evolution of sulphurous anhydride. The
upper oily liquid is separated from the acid on which it floats, well washed, and distiUed,
and the portion which passes over from the 170° to 175^ is collected and rectified.
It is an oily liquid, whose vapour-density, as found by experiment, is 6*19 to 5*27.
Now the formula^ C^H'^O, if supposed to represent 2 volumes of vapour, gives for the

calctdated vapour-density the number 10*04 ( « 5 x 0*0693), which is

nearly double the experimental number. Consequently, the molecule O'H'K) repre-
sents 4 volumes of vapour, and probably splits up at high temperatures into Cfl"
and H^O, each of which occupies 2 volumes. (See Atomic Wbiohts, p. 469.)

Monohydrate. C"H"0 = C'*H".BPO.— This is the chief constituent of oil of
cajeput (p. 710), and passes over in the fractional distillation between 175^ and 178^ C.
After rectification, it is a colom'less oil which boils constantly at 175^, has a specific
gravity of 0*903 at 17® C, and vapour-density, by experiment « 5*43 ; by calcmatioB
(2 vol.) a 5*338. It dissolves in all proportions in alcohol, ether, and oil 0/ turpentiw.

Exposed to the air for a considerable time, in the moist state, it changes to a reddish
liquid, which ultimately exhibits a rather strong acid reaction with litmus. Iodine
dissolves in the oil, and under certain circumstances forms crystalline compoonds
(p. 712). Bromine acts quickly upon it, and under similar circumstances forms crys-
talline compounds (p. 711). Chlorine gas passed into the oil raises the tempentaie,
but does not appear to act upon it furtiier ; but nascent chlorine (evolved by paasfng
hydrochloric acid gas into the oil mixed with dilute nitric acid) converts it into di-
chloride of csjputene, C**H**C]'. Fhosphortc anhydride heated, with the monohvdrate
takes away the whole of its water, converting it into ci^putene, isocajputene, and psn-
cajputene (p. 711). Chloride of einc likewise dehydrates it, but less completely, ^rong
mljphurtcacid acts but very slowly on the oil at low temperatures ; but if the tempera-
ture be allowed to rise, sulphurous anhydride is given ofi^ and the oil blackens and ulti-
mately suffers complete decomposition. If the action be checked at a ceztain point, a
sulpho-acid is formed, which yields a soluble barium-salt Oil of vitriol dropped into
the oil at the boiling heat,^ in the manner above described takes away half tiie ▼ato',
forming monohydrate of cajputene. Dilute sulphuric acid, on the contrary, erases the
monohydrate to take up 2 at. more water, converting it into C"H".3H*0. FtoMft^
sulphuric acid converts the monohydrate into a thick brown liquid, which boils above
360®. Fuming nitric acid rapidly oxidises the oU, even at ordinary temperatuiM,
forming a large quantity of oxalic acid. Ordinary nitric acid produces the same eftct
at the boiling heat, but at ordinary temperatures it acts very slowly, converting the
oU into a red liquid. Distilled over permanganate or acid ckromate of potassitm in
presence of sulphuric acid, it forms a thick resinous liquid. It does not appear to be
altered b^ digestion with peroxide of lead. In contact with aqueous |wtoAl, or vfaen
dropped into melting potash, it forms a soluble salt, the acid of which is precipitated
as a resin by hydrochloric or sulphuric add. Heated with sodium, it forms a oystal-
line mass, soluble in water and alcohol, and consisting of soda and an oi^ganic substance,
which is separated b^ strong acids in the form of a fragrant resin. When the vapoor
of the monohydrate is passed over red-hot soda4ime, a yellow oil distils over, haviog
a peculiar odour quite different from that of the monohydrate ; at the same tuse
the soda-lime becomes blackened by deposited charcoal, and when treated with acids^
gives off a large quantity of carbonic anhydride. The yellow oil thus formed yielded
by distillation, a fraction boiling between 180® and 185® C. which gave in two analyse^
79-76 and 80*03 per cent. C, 12*20 and 12*07 H, agreeing nearly with the formula
C"BP*0«, which requires 79*69 per cent C, 12*24 H, and 7*97 O.

Trihydrate of Cajputene, Om^O* ^ C>*H".3H«0. —Produced bytheaction
of dilute sulphuric acid on the monohydrate, or on crude oil of cjyeput. Two pts. of
dilute sulphuric acid are added to 1 pt of the crude oil ; and the mixture is r^
shaken for several days tiU the watery liquid acquires a yellowish colour, and then left
to itself for about ten days, whereupon it deposits ciystalline tufts of the trihydrate,
adhering to the sides of the vessel The crysUds melt at 120® C. and solidify again at

C A JPUTENE — CALAMINE. 713

SS^. On sabmittiQg them to dry distillation, an oily liquid passes over and condenses
again in the colder p<irts of the apparatus, appi^ently as the unaltered trihjdrate. The
ciTstals diasolye sparingly in cold, easily in boiling alcohoL

Grystals having the same composition were deposited from a secondary fraction of
crude cajeputoil, which distilled at 210^ — 230^ C, and was left for a yery Ions time
moist and exposed to the air. The crude oil mixed with nitric acid and akohol|
changes, in the course of seven or ei^ht months, into a black heavy liquid in which
crystals are suspended, perhaps consisting of the trihydrate. The same compound
ai^>eani likewise to be lormea in beautiful long prisms, when the crystaUine mass
produced by passing hydiochbric acid gas into rectified oil of cajeput is thrown into
water or alconoL

Htdbochi^batbs of Cajputene. — ^The monohydrochlorate, C**H*'.HCI, is obtained
by distilling the dihydrochlorate, and collecting apart tho fraction which boils at 160^ C.
— A product having the same composition is obtained by treating the dihydro-
chlorate for several days with aqueous or alcoholic potash ; but its odour is ^jQerent
from that of^e product obtained by simple distillation of the hydrochlorate^ and re-
sembles that of pelargonic ether.

The dihydrochlorate, C"H** 2HC1, is obtained by passing hydrochloric acid gas
through rectified cajeput-oil, mixed with a third of its volume of alcohol or strong
aqueous hydrochloric acid. It crystallises from alcohol in beautiful radiating tufts ;
melts at 65^0. and solidifies agam at 30°. It has no taste or smelL By dry distil-
lation, it gives off. hydrochloric gas at 60°, and splits into several fractions, one of
which is uie monohydrochlorate. It is also deprived of half its chlorine by heating
with aqueous or alcoholic potash. It dissolves sparingly in cold, easily in boiling
alcohol or ether.

Htbbiddatb or Cajputene. o. Anhydrous, C*"H*'.HI. — Obtained by adding a
solution of phosphorus in sulphide of carbon to a solution of iodine and oil of caje-
put in the same liquid. The liquid becomes hot, assumes a reddish colour, deposits
red oxide of phosphorus, and gives off vapours, probably containing phosphoretted
hydrogen, and after ten or tw^ve days deposits crystals of Uie hydnocutte. The re-
action is perhaps :

6(C»»H".H«0) + 6PI « 6C»*H"I + 2PH" + PK) + P'O*.

The crystalB are deposited in cells like those of beehives, and possess a black metallic
lustre. The^ are soluble in alcohol and ether, and are very stable, not being altered
even by boiUng with potash.

b. HydraUd, C»H«I«0 - 2(C"H".HIVH«0, or HydriodaU of Hemhydrated Caj-
putene, C*H'*0.2HI. — If iodine be added by small quantities, and with constant
stirring, to cajeput-oil till the temperature rises from 10° to 40° C., and the vessel be
then immersed in cold water, a black crystalline compound soon separates from it, and
on filtering, pressing the black substance between paper, and then dissolving it in
alcohol or eUier, a solution is obtained, from which the nydrated hydriodate crys^llises
in prisms having a fine yellow-green colour and metallic lustre, and melting at 80° C.
to a compound which does not reciystallise on cooling. Potash dissolves the crystals,
abstracting part of the iodine in the cold, and the whole when heated. The crystals
are insoluble in water, and are not decomposed thereby; they dissolve readily in
alcohol and ether.

Syn. of TuBQuois.

Native Carbonate of Zinc, Zinc-spar, Smttheonite, Galmei Zn'CO'.
— This mineral, which is one of the most abundant ores of zinc, occurs crystallised in
rhombohedrons with cleavage parallel to the rhombohedral faces. Katio of principal
to secondary axes » 0*8070 : 1. Inclination of terminal faces = 107° 40'. Also reni-
form, botryo'idal, and stalactitic, and in crystalline incrustations ; likewise granular,
earthy, and friable. Specific gravity b 4*45 ; hardness » 5. It is translucent or
Bubtransparent; white when pure, but often tinged more or less with grey, green,
or brown, from admixture of the carbonates of iron and manganese. Streak white.
Lustre vitreous, inclining to pearly. Brittle, with imeven, imperfectly concho'idal
frmcture.

Pure calamine is found in Somersetshire and Derbyshire. A specimen fr^m Somer-
setshire analysed by Smith son (Nicholson's Journal, vi. 76) gave 36*2 per cent CO',
and 64*8 ZnK), which is exactly the theoretical composition. Generally, however, a
portion of the zinc is isomorphously replaced by iron, manganese, calcium, inagnesiara,
lead, and copper. The following are examples: a. From Nertzchinsk in Siberia,
analysed by^obell (J. pr. Chem. xxviii. 480.) 6, r, d. From Altenberg near Aix-la-
ChapeUe (Monheim, Rammelsberg's Minerahhemie, s. 227.) e,f From Herrenborg

714

CALAMINE — CALCIUM.

. 9600

9-oa

. eo-M

8S*3I

4-08

1-90

0-14

. bbt»

86-46

8-47

«.

. 84^

1*08

6-HO

I'M

8*84

. 8ft^

f94

7-68

098

4*44

. 74*4S

8*80

14-98

1-68

8^18

. M'74

—

1-ftO

1-48

0-39

riff, 114.

near Nirm, Aachen (Mo n h e im, Und) g, A capriferoiu Tariety called Herradte, ftom
Albamdon in Mexico. (Genth, SilL Am. J. ii. zx. ; J. pr. Chem. Lltl 475.)

Zo«CO* Fe*CO> Mn<CO> Ca*CO> Mg^CO^ FbKVi^ Cit«COs SIO* Zo«aiO« H«0

I-I8 - - - ^ m»\\

— — — 8-49 — • 101*11

— — _ 0-41 - s 9H0

— — — 1-86 - B S8-»7

— — 009 — tnera 10l*|l

— — Onto — O-Kb 9RiS

— 8-48 — — - ■ lOBra

OllliAMJJUt snUOBOinL &liceou8 oxide of zine. Hydrous stUeate of nar.
Zin^hglance, KisuUinkerz, KiesdgalmtL Zn^SiO^ + HH). — (Dana applies to thii
mineral the name calandne^ i^iatingtiiRliing the preceding aa Smithsoniie.) Ooeios in
ciyatala of the trimetric sjatem. Ratio of brachydiaeonal, macrodiagonal, and pria*
cipal aziB « 0*6385 : 1 : 0*6169. The dyatals are short pnama (fy, 114) rsiuUag

from the predominance of the fiusea oofo and oo^oo, and no-
symmetricallj terminated, viz. at one end by the Ucm P,
and at the other by 2^ao , too . OP . {I^ao(y) and |P«(').
Indination of faces, oe^ : 00^2 » 103^ 63'; (Poo :j]^« -
6I0 34'; (oo : |»oo - 63° 20'; 2P : 2Pa> -101° ^. QeaTige
perfect oaiallel to 00]^ ; somewhat lesa, parallel toj^oo (Kopp's
Xrystauoffraphie, pp. 260, 264). The mmeral likewise oeeon m
staladitic, mammilfaiy, botiyoidal, and fibrous forms; also mis*
sire and grannlar. Specific gravity 3*16 — 3*9. Hardness a
4*5— 5. It is white when P^u^ sometimes blue, more or \m
coloured by oxide of iron. Transparent or translooent Lostie
generally Titreons. Streak white. Brittle, with mieren fiartoie.
like many other uisymmetrioal minerals; it is pyrodaetrieL

Before the blowpipe' it melta with difficolty at the edges; it
18 not altered by heating on chaicoal, either alone or vith ca^
bonate of sodinm ; but with carbonate of aodinm and bonz it
is completely reduced, with formation of a zinc-deposit It n
>A y/^ easily decomposed by acids, with separation of gdatinou sflica ;

^\^ it alao diasolyes in potash-ley.

Siliceous calamine generally occurs nearly pure. A spedmen
ftrom Tamowita in Upper Silesia, analysed by RammeUberg, yielded 24*99 SiO', 68*66
Zn*0, and 775 H«0 « 101*40; the formula Zn^SiO* + HH5 or 2ZnK)JSiO» + ffO,
requiring 25*1 SiO*, 67'4 Zn"0, and 7*5 HK). Sometimes a small portion of the sine is
partly replaced by iron or lead : in a specimen from Nertzschinsk in Siberia, Henoans
found 2*70 per cent oxide of lead.

Siliceous calamine usually occurs, associated with the natiTe carbonate, in ealcareoM
rocks. Large crystals are found at Nertzchinsk. (Dana, ii. 314; Bammelsberg'i
Minerdchemie, s. 549.)

OIHLAimTB. A Tariety of tremolite {q. v.) having an asparagus-given coloor.

See Calospab. — OA&OB]>OVT. See Chalodoxt.

"^c^yi

Pliny's term for copperas.

The filxed residues of- such matters as have undngone oom-'
bustion are called cinders in common language, and calces, or oxides, by ehemists;
and the operation, when ccosidered with regard to these residues, is teived eskina-
tion. In this general way it has likewise been applied to bodies not really oombnstibl(r
but only deprived of some of their principles by heat. Thus we hear of the cslcinatioo
of chalk, to convert it into lime, by driving off its carbonic acid and water: of gjrpeom
or plaster stone, of alum, of borax, and other saline bodies, by which they are deprived
of their water of crystallisation ; of bones, which lose their volatile parts by this treat*
ment ; and of various other bodies. (See CoMBUsnoiv.)

OA&CZra. Syn.wiihaALC8PA&(p. 721).

CAJbOZUBK. SyniMy Od. .< AUmie weight, 20.— Lime, the oxide of ealdim, hss
been known from the earliest times, and was used by the ancients in the oompositioB
of mortar. Black, in 1756, first pointed out the difference between burnt and nnbnrnt
lime. The metal was first inoompletelv isolated by Davy in 1808, and has reeeotly
been obtained in the pure state by Matthiessen.

Calcium is the most widely diffused of the alkaline-earthy metals. The cari)onate
occurs in a great variety of forms, and, as limestone, constitutes entire mountain rsnges.
The sulphate, fluoride, phosphate, and silicate are also abundant nataral prodocti
Less frequent are the cUoride, nitrate, arsenate, and tungstate. Caleinm also exists
as carbonate and phosphate in the bones of animab ; the ahells ci molluscs are ahncst

CALCIUM: BROMIDE— CHLORIDE. 715

atirety eompoaed of the carbonate. In the bodies of plants, caldum exists in oombina*
tion mth Tarious ofganic adds.

PrtparoUon of the Metal.'-^jytkyj in 1808 obtained caldum in an impure state by
eleetiolysis, similarly to barium (p. 600^ and by passing yapour of potassium over red-
hot lime (?) Matthiessen (Chem. Soc. Qu. J. Tiii. 28) prepares the pure metal as
follows : — A mixture of 2 at. chloride of caldum and 1 at ch£>ride al strontium, with
a small quantity of chloride of ammonium ^this mixture being more fusible than
chloride of caldum alone), is melted in a small porcelain crudble, in which a carbon
poaitiTB pole is placed, while a thin harpdchord wire wound round a thicker one, and
dipinng only just below the surface of tne melted salt, forms the negative pole. The
caldum is then reduced in beads, which hang on to the fine wire, and may be sepa-
rated by withdrawing the negative pole every two or three minutes, together with the
small crust which forms round it. A surer method, however, of obtaining the metal,
though in veiy small beads, is to place a pointed wire so as merely to touch the surface
of the liquid ; the great heat evolved, owing to the resirtance of the cuirent^ causes
the reduced metal to fuse and drop off from the point of the wire, and the bead is taken
out <^ the liquid with a small iron spatula. Or, thirdly, the disposition of the appa-
ratus may be the same as that for the reduction of strontium {q, v.^

Li&s-lBodart and G-obin ^Comptrend. xlviL 23) prepare calcium by i|piitingthe
iodide with an equivalent quantity of sodium in an iron crudble, baring its lid screwed
down. According to Dumas (Compt rend, xlvii. 176) it ia essential that the process
be conducted in a dosed vessel, as, under the ordinaiy atmospheric pressure, the sodium
bums away, and the iodide of caldum remains unaltered.

Properties. — Caldum is a light yellow metal, of the colour of gold alloyed with
silver ; on a freshly cut surface the lustre somewhat dimilushes the yellow colour,
which becomes more apparent when the light is reflected several times from two sur-
faces of caldum, or when tlie sur^Kce is slightly oxidised. It is about as hard as gold,
veiy ductile^ and may be cut^ filed, or hammered out into plates having the thidmess
of the finest paper. Its spedfic gravity is 1*6778. In <uy air the metal retains its
colour and lustre for a few oays, but in damp air the whole mass is slowly oxidised.
Heated on platinum-foil over a spirit-lamp, it bums with a very bright flash. It is not
^uiddy acted on by dry chlorine at ordinary temperatures ; but when heated, it bums
in that gas with a most brilliant light ; also in iodine, bromine, orjrgen, sulphur, &c.
With phosphorus, it combines without ignition, forming phosphide of caldum. Heated
mercury dissolves it as a white amalgnm. Caldum rapidly decomposes wat-er, and is
still more rapidly acted on by dilute nitric, hydrochloric, and sulphuric adds, nitric
acid often causing i^ition. Strong nitric ada does not act upon it below the boiling
heat^ In the voltaic circuit, with water as the liquid dement, caldum is negative to
potasdum and sodium, but positive to magnesium. It is not, however, reduced by
potasdnm or sodium ftom its- chloride by electrolysis. On the contrary, a ftased
mixture of CaCl with £C1 or NaCl, in certain proportions, yields potasdum or sodium,
when sulgected in a certain manner to dectric action ; hence it appears that the metal
formerly obtained by redudng chloride of caldum with potassium or sodium, could net
be calcium, but was probably a mixture of potassium or sodium with aluminium,
silicon, &a ^Matthiessen.)

Caldum unites with all the non-metallic elements, forming compounds into which it
enters for the most part as a monatomic radide, e,^, the chloride CaCl, the oxide CaK),
the sulphide Ca*S, &c Most of the compounds are colourless ; they have an acrid
taste, and a lower spedfic gravity than the corresponding compounds of barium and
strontium. Of the compounds of caldum with other metals, little is known, excepting
that it forms an amalgam with mercuiy.

OA&cmraif BBOmsa of. OaBr. — Formed Hv the direct union of caldum
and bromine, or by dissolving lime or the carbonate in hydrobromic acid. The solq-
tion yidds bv evaporation colourless silky needles of the hydrated bromide^ from
which the anhydrona bromide may be obtained by heating. It is deliquesceni and
very soluble in alcohoL

OASmUBIf <nnbOXXDB of. CaCL — This compound exists in sea-water,
river-water, and spring-water, and is produced by pasdng chlorine over red-hot lime,
or better by dissolvinff lime or the carbonate in hydrochloric acid, and evaporating.
It is also fvoduced in large quantity in the preparation of ammonia by heating sal-
ammoniac with slaked Ume : .

^ .NH«a + CaHQ^- CuCi + NH* + H*0.

The residue is treated with water ; the solution, which is always alkaline, is neutralised
with hydrochloric «kdd, and the residue evaporated to dryness.
The aqueous solution, when highly concentrated, deposits the hydrated chloride,

716 CALCIUM ; DETECTION.

CaCl.SH'O, in six-sided prisms with pyramidal summits. It has a bitter taste. The
crystals give off 2 at. water when dried in vacao, leaving the hydrate CaCLHH), which
retains the original form of the crystals, but is opaque, and has the appeazance of talc
(Ghraham). At 200° C. they part with the whole of their water, leaving the anhy-
drous chloride in the form of a white porous mass.

The anhydrous chloride melts at a low red heat. If it be then exposed to the sun's
rays, it afterwards appears luminous in the dark ; it was formerly called Howber^^t
phosphorus. When ignited in contact with the aii? it is partially converted into oxitlc
and carbonate of calcium. Hence the porous chloride dned at about 200^ C. is better
adapted for absorbing water in organic analysis (p. 228) than the fused chloride ; the
latter, containing lime, absorbs carbonic acid as well as water.

Anhydrous chloride of calcium is exceedingly greedy of water, and is one of the
most deliquescent substances known. 100 pta of it in powder exposed to an atmo-
sphere saturated with moisture absorb 124 pts. of water in ninety-six daya, more, there-
fore, than is required for complete deliquescence(Brandes,Schw. iL 433). The
crystallised chloride also deliquesces rapidly, and dissolves in half its weight of water
at 0° C, in one-fourth of its weight at 16°, and in every proportion of hot water. The
solution of the anhydrous chloride in water is attended with considerable evolution of
heat ; but the hydrated chloride in dissolving lowers the temperature of the liquid.
A mixture of dystaliiBed chloride of calcium and snow produces a degree of cold suffi-
cient to freeze mercury.

Both the anhydrous and the hydrated chloride dissolve readily in alcohol. 10 ptjc.
of absolute alcohol at 80° C. dissolve 6 pts. of anhydrous chloride of calcium; and the
solution when evaporated in vacuo, at the winter temperature, yields rectan^niUr
laminse containing 59 per cent of alcohol, agreeing with the formula 4CaCL7C?HK>.
The alcohol in this compound appears to take the place of water of crystallisation. It
likewise forms similar compounds witJi methylic and amyHc alcohols.

Chloride of calcium combines with ammonia^ forming the compound CaC1.4KH*, it
cannot, therefore, be used for drying gaseous ammonia. It unites also with chnmae
aeid and with acetate and oxalate of potassium.

A solution of chloride of calcium boiled with slaked lime dissolves that substance,
and the Altered solution deposits an oxychloride of calcium, 2CaCL3Ca*0 + 15H'0,
which is decomposed by pure water and by alcohoL

CAXiCZnXOp BXTBCTZOV AJTB B8TIBKA.TZOV OF. 1. Reactions in
the dry way. — The hydrated chloride and a few other calcium-compounds, when heated
in the blowpipe flame on platinum-wire, impart a red colour to the flame, similar to
that produced by strontium-salts, but less intense. The colour di^Lppedrs as soon as
the salts are dehydrated, and is not produced at all if barium is likoni'ise present.
Alcohol burned on soluble calcium-salts exhibits a red flame tinged with yellow.

The spectrum of a flame in which a volatile calcium-compound is ignitoi, according
to Bonsen and Kirchhoff's method (p. 214), is distinguished by a broad bright green
line situated at about the confines of the green and yellow of the normal solar spec-
trum, and an intensely bright orange line situated nearer to the red end of the spec-
trum than the orange band of strontium, and about midway between the lines C and
D of the solar spectrum. This reaction is best seen with the chloride, bromide, and
iodide of calcium ; the sulphate does not produce it till it has become basic, the car-
bonate exhibits it most distinctly after the carbonic add has been expelled. Com-
pounds of calcium with the non- volatile acids require to be decomposed, generally
by hydrochloric acid. To obtain the reaction with silicates not decomposible by hy-
drochloric acid, a small quantity of the mineral in fine powder is mixed on a platinum
plate with excess of fiuoride of ammonium, and gently heated till all the fluoride is
volatilised ; the residue is then moistened with smphuric acid, and the excess of that
acid driven off. If the remaining substance be ignited in the flame as above, the cha-
racteristic spectra of the alkaU-metals, if present, are first seen, and afterwards those
of strontium and calcium. If only a trace of calcium is present, the bead must be
held for a few minutes in the reducing flame of the blowpipe, then moistened with
hydrochloric acid, and again ignited in the gas-flame.

2. Reactions in the wet way. — The bromide, chloride, iodide, nitrate, acetate, and
many other organic salts of calcium are soluble in water ; the carbonate, borate, phos-
phate, arsenate, and oxalate are insoluble, the sulphate sparingly soluble ; all of them,
however, except the sulphate, dissolve readily in nitric or hydrochloric acid.

In the aqueous solutions of calcium-salts, potash or «o<2a produces a white gelatinous
precipitate of hydrate of calcium, unless the solution is veiy dilute. Amtnonia : no
precipitate. Neutral carbonates of alkali'metals : white precipitate of carbonate of
calcium, soluble with effervescence, in nitric, hydrochloric and acetic acids. Acidcar^
honcUes of alkali'Ttutals : no procipitiite in the cold; pulverulent precipitate on boiling,
attended with escape of carbonic acid. Sulphuric acid and soluble sulphates .* white

CALCIUM: ESTIMATION. 717

precipitata of solphate of caldmn, Tmless the solution is \eej dilute ; in that case, the
precipitate appears on addition of alcohol, in which the sulphate of calcium is quite
insoluble. Oxalic acid and oxalate of ammonium, : white precipitate of oxalate of
caldnm, easily soluble in nitric or hydrochloric acid, but insoluble in acetic acid.
Bulphydric aad, alkaline sulphides, ferrocyanide of potassium, hydrofluosUicio acid :
no precipitate.

By these characters calcium in solution may be immediately distinguished firom all
other metals, except barium and strontium, and from these it may be distinguished
by the greater solubility of its sulphate. A solution of sulphate of calcium gives a
white precipitate immediately with a soluble barium-salt, and after a while with a salt
of strontium.

3. Quantitative Estimation, — Calcium maybe estimated either as carbonate
or as nilphate. The best method of precipitating it, is in most cases by oxalate of
ammonium, the oxalate being the least soluble of idl the salts of calcium. If the solu-
tion contains an excess of any strong acid, such as nitric or hydrochloric acid, it must
be neutralised with ammonia before adding the oxalate of ammonium, because oxalate
of calcium is soluble in the stronger acids. The precipitate, after being washed with
hot water and dried, is heated oyer a lamp, care being taken not to allow the heat to
rise above low redness. It is thereby converted into carbonate of calcium containing
40*16 per cent of calcium or 56*12 of lime.

I^ however, the solution contains any acid which forms with lime a compound in-
soluble in water, phosphoric or boracic acid for example, this method of precipitation
cannot be adopted ; because, on neutralising with ammonia, the lime would be preci-
pitated in combination with that acid, and would not be converted into oxalate on
addition of oxalate of ammonium. In such a case, the calcium may be precipitated as
sulphate by adding pure dilute sulphuric add and alcohoL The sulphate, when dried,
contains 41*25 per cent of lime. From acid solutions of phosphate of calcium the
metal may, however, be precipitated by oxalate of ammonium, with addition of acetate
of ammonium, because oxalate of caldum is insoluble in acetic acid, which dissolves
the phosphate with facility.

4« Separation from other Elements. — ^From the metals of the first group
(p. 217) caldum is easily separated by sulphydric add, from those of the second, by
sulphide of ammonium.

From the alkali-metals, caldum is easily separated either by oxalate of ammonium,
or by sulphuric acid and alcohol.

Calcium is separated firom barium by predpitating both the earths as carbonates,
dissolving the carbonates in nitric acid, evaporating to dryness, and digesting the
reddue in absolute alcohol, which dissolves nitrate of caldum, but not nitrate of
barium. They may also be separated in this manner in the form of chlorides, but the
separation is less complete, because chloride of barium is not quite insoluble in abso-
lute alcohoL

From strontium, caldum is separated in the same manner, nitrate of strontium being
likewise insoluble in absolute alcohol.

When baryta, strontia* and lime occur together, the baryta is first separated bv
hydro-flnosilidc add ; the strontia and lime in the filtrate are then converted into sul-
phates; these sulphates, after bdng weighed, are converted into carbonates, either by
fusion with carbonate of sodium or by boiling with the aqueous solution of that salt ;
the carbonates weighed ; and the quantities of strontium and calcium determined, as fol-
lows : — ^Letf be the wdght of the strontium, y that of the caldum, s that of the sul-
phates and e that of the carbonates ; then we have the equations :

Sr«SO* Ca«SO« Sr»CO> Ca«CO«

183-8 136 157-8 100

*^'-9f8' + -40^ "'' ^97^'+^y "^-

Or, the carbonates may be dissolved in nitric add, and the nitrates separated by abso-
lute alcohol, as above.

5. Atomic Weight of Calcium, — Dumas found that 100 pts. of Iceland spar,
Ca*O.CO^ yielded by calcination 56 pts. lime, Ca^O, whence (since CO*»44) the
atomic weisht of lime a. 56, and that of calcium 20. Erdmann and Marchand, and like-
wise Beizelius, in repeating this mode of estimation, found for calcium the number
20*03. Berzelius (Trait^ iv. 538) by converting pure lime into the sulphate, found
Ca a 20*13. Lastly, Dumas (Ann. Ch. Pharm. cxiii. 33) has determined this number by
decompodng pure chloride of caldum with nitrate of silver. White marble was treated
with oilute hydrochloric add; the solution mixed with excess of lime (prepared from
the same marble); the filtrate evaporated ; the residue again treated with hydrochloric

718 CALCIUM: FLUORIDE-^ OXIDE.

acid, and ignited in hydrochloric add gaa ; and tbe pure chloride of alanm tina
obtained waa decomposed by nitrate of silTer. l^iiee experiments thus made gare
reepectiyely Ga — 20'00, 20*03, 20-00. The number 20 is generally adopted.

OFa CaF. — ^Thia compound ocean abondutly in
nature, Bometimea maasive, sometimea crystallifled in octahedrons, cubes, sod other
forma of the regular system (see Fluob-spab). It ia pecnUariy a eonsdtneBt <tf
metalliferous veins. In minute quantity it is very generally diffused, being sssodaled,
to the amount of a few thousandths, with phosphate of calcium, in the bones of aoiiaala,
and in somewhat larger quantity in the enamel of the t-eeth ; minute quantities of it
also foimd in plant-ashes and in the earthy deposit formed in sea-water by boOin^
It may be prepared artificially as a gelatinous mass, by precipitating a soluble eakiim*
salt with fluoride of potassium or sodium, or in the granular at^ by neatnlisiog
hydrofluoric acid with carbonate of calcium.

Fluoride of calcium dissolves in about 2000 pts. of water at 16^ C. (GK WiUon),
and somewhat more abundantly in water containing carbonic acid ; hence its ooeoiraioe
in sea- water. It dissolves in free hydrofluoric acid and in a^ng hydrochloric acid,
and is precipitated as a transparent jelly by ammonia. It melts at a high tempeiatine^
and crystaUisee on cooling. It is decomposed at a high temperature by vaponr of vater,
yieidi^ lime and hydrofluoric acid. Fused with hydrate or carbonate of potaa*
sium, or sodium, it yields oxide or carbonate of calcium and an alkaline fluofide.
Strong sulphuric acid does not decompose it at ordinary temperatures, but on heatii^
the mass, hydrofluoric acid is given off, and sulphate ox calcium remains. Vapour i
sulphide of carbon passed over a red-hot mixture of fluorspar and charcoal at a red
heat, decomposes the fluoride completely, forming sulphide of calcium and Tolatfle
fluorine-compounds. It is also decomposed at a red neat by chlorine. (Ftimj.)
(See Fluobimb.)

Fluor-spar is much used as a flux in metallurgic operations, especially in the trea^
ment of copper ores ; also in the reduction of alumimum (p. 161).

CA&CZiniK« SOnXBB 07« Cal. — ^Prepared by heating calcium in iodine Tapoor
or by dissolving lime or the carbonate in hydriodic add, evaporating and ftaing the
residue in a dosed vessel. Resembles the cmoride, melta below a red heat, and if ia
contact with the air, is decomposed, with formation of lime and separation of iodina
Very soluble and deliquescent. Decomposed by sodium at a red heat The hydxate
ciystallises in long needles.

OAAOZVM, OZZHa OF. Lime^ Ca*0, or Ca 0.— Anhydrous or gnid: lime is ob-
tained by heating to redness the carbonate, nitrate, or any salt of ealrinm coo-
tainins an acid easily expelled by heat ; but for actual preparation, the carbonate ia
the only salt employed. In a closed vessel capable of resisting pressure, carbonate of
calcium may be melted without undergoing decomposition ; but when heated to rednetf
under the ordinary atmospheric pressure, it eives off carbonic anhydride and learea
lime (CaK)0* » Ga*0 + GO'). On the smaU scale, the decomposition may be ^
formed in a crucible heated in a furnace ; to obtain perfectly pure lime, the oystalhsed
carbonate or the finest Carrara marble should be used. On the huge scale, masses of
limestone are burned in kilns, the mineral being mixed up with the coal or other com-
bustible matter. In general, one bushel of coal is sufficient to make five or six bushels
of lime ; magnesian limestones require less fuel than pure limestone. When a lime-
stone containing much aluminous or siliceous eartii is to be burnt, great care should
be taken to prevent the fire from becoming too intense ; for such lime easfly ritrifiea.
The kilns for burning t-hese argiUaceous or siliceous limestones should be prorided
with a damper. (See Ur^s Dictionary of Arts, Mantifaetures, and Mma^ ii 729.)

Pure lime forms white hard porous masses of specific gravity 2*3 to 3*08. It bean
the strongest heat without decomposition, and melts only in the flame of the oxyhy-
drogen blowpipe or in the voltaic are. Its most remarkable property is the aridity with
which it takes up water. When water is poured upon pure ume, it is instanuy ib>
sorbed, and in a few seconds the lime becomes hot, gives off a Uu^e quantity of steam,
and crumbles to powder : this is called the daking of lime ; with krge masses the
evolution of heat and escape of vapour are very violent. lime which slakes easilj, is
called /a^ lime. Impure lime, especially that which contains clay, takes op m^ ^
slowly : such lime is said to be poor.

The product of the action of water on lime, is hydrate o/ealcium or hydrate ofUfitfj
CaHO or CaH).H«0. It is a white soft powder, which grves off its water at » red
heat, and ia reconverted into quicklime. It is sparingly s^uble in water, more i^^
ttian in hot water : hence, water saturated with lime in the cold, deporits the hydrate
when boiled. A solution evaporated in vacuo over oil of vitriol, deposits the ^X"^
in hexagonal prisms (Gay-Lussac). According to Dalton, lime-water fonned atwr
130°, and 2120 (Fahr.) contains 1 grain of lime (anhydrous) in 778, 972, and 1270 ga

CALCIUM: OXYCHLO RIDE— PHOSPHIDE. 719

of water. The solution, called lifne-tDater, is alkaline, and has a caustic taste. It pre-
cipitates most metallic oxides from their solutions, all those in fact which are insoluble
in water; also carbonic^ ^ boradc^ silicic, and phosphoric adds when added to their
neutral or alkaline solutions, or in excess to their acid solutions. When exposed to
the air, it soon becomes ooTered with a pellide of carbonate of caldum. The solid
hjdrate also absorbs carbonic add from water, forming, according to Fnchs, the
hydrocarbonate Ca'CO*.HCaO.

Lime dissolves readily in nitric, hydrochloric, and acetic acid. The hydrate exposed
to the action of chlorine gas, forms a mixture of chloride and hypochlorite of caldum,
commonly called chloride of lime or bUaehing powder:

Ca*0 + CI* - CaCl + OaaO.

Chlorine does not act upon anhydrous lime or on the carbonate.

lime is applied to a varietjr of useful purposes : — 1. For making mortar. The
lime in the state of hydrate, is mixed witn 2 pts. of coarse or 3 pts. of fine sand, and
made with water into a paste, which as it dries, absorbs carbonic add slowly from the
air, and is converted into a hard mass of "hydrate and carbonate, which binds the
stones or bricks firmly together. The chief use of the sand is to prevent by its mass
the too gfreat contraction of the mortar in drying. — 2. In tanning, to promote the
separation of the hair or wool firom the skins, and of the fat and fieshy parts. — 3. In the
preparation of caustic alkalis frova. their carbonates. — 4. In the saponification
of fatty bodies intended for the preparation of stearine candles.— 6. In the defe-
cation of sugar (see Suoab). — 6. As a manure. Soils containing too much day,
are often mix^ with lime, which, by absorbing water and carbonic acid, swells and
disintegrates, and thus renders the soil lighter. It also exerts a decomposing action
on the clay, rendering the silicate of potassium soluble.

Peroxide of Caleium^ CaO, is known only as a hydrate, which fidls down in very
fine ciystalline scales when lime-water is mixed with an aqueous solution of peroxide
of hydrogen. (Th^nard.)

OlA&caVM« OJLTOS&OBHia or. (See page 716.)

CAl^lIUMf OXTCHOr-BJk&TS OF. See the several Aoros.

OA&CIVME, OXnmVKma of. When sulphide of calcium prepared by
Tedndng the sulphate with charcoal, is boiled with a large quantity of water, the
solution filtered hot, and evaporated in a retort containing air, a laiffe quantity of
sulphuretted hydrogen escapes with the watery vapours : the cooled liquid deposits
sulphite of calcium, and on further concentrating the mother-liquor, gold-coloured
neoiles are obtained consisting of an oxysulphide Ca'%^0 + 20 aq. When heated out
of contact with the air, they give off water and sulphur, without alteration of form, and
leave a white residue, which, when treated with hydrochloric add, deposits sulfur,
gives off snli^uretted hydrogen, and forms a product containing sulphate of caldum.
(H. Bose, Jrogg. Ann. xv. 433.)

CUk&OZmif VBOSFSna of. CaP or Ca7 ? —Prepared by passing vapour
of phosphonis over red-hot Hme. A good mode of proceeding is to place a few pieces of
phosphoms at the dosed end of a combuation-tabe, fill the tube with small lumps of

Suick lime (made by forming slaked lime into pellets and calcining them), then heat
be part o£ the tube oontainiuff the lime to redness, and pass the vapour of phon>hortts
over it by cautiously surrounding the dosed end of the tube with not fuel. To pre-
pare larger quantities, a cmdble having a hole at the bottom is filled with pellets of
lime, and placed on the grate of a fbmace, and a flask containing phosphorus is placed
below the grating with its neck passing upwards through the hole in the emdble. The
fire is then lighted, and as soon as the crudble is red-hot, the phosphorus in the flask
is gradually heated, so that its vapour may pass upwards through tne lime. The pro-
duct is a brown mass consisting, according to Th^nard, of hemiphosphide and pyro-
phosphate of caldum :

7Ca«0 + F « 5Ca«P + Ca<FO».

According to Gmelin (Handb. iii 188), it is a mixture of monophosphide and tribasio
phosphate of caldum :

4Ca«0 + !»• - 6CaP + Ca«PO«

Posdbly both these reactions may take place together. The product, when thrown
into water, is immediately decomposed, with evolution of sponteneously inflammable
phosphoretted hydrogen :

3CaP + 3BP0 - PH« + 3CaH0 + I«; or 3Ca«P + 3H«0 « 2PH* + 3Ca«0 + P.

Part of the diphosphide may also be decomposed in the manner represented by the
equation :

Ca»P + n«0 - PH« + CaK).

720 CALCIUM: SELENIDE— CALCOFERRITE.

The formation of the compound PH^ may accoant for the spontaneous inflammability
of the gas. (See Phosphobbtted Hydrogen, under PHosPHO&oa.)

CJLXiCXirAKp BMLMMTUMB OF. A monoadenide is formed bj pred{dtating
chloride of calcium with monoselenide of potassium ; it is a flesh-coloured predmtate.

A poiyselenide, mixed however with selenite of Anlffiniri, ia produced by heatiiig
lime with selenium to a temperature just below redness. lime-water saturated vith
seleniuretted hydrogen, deposits crystals of [mono ? ] selenide of calcium when eipoied
to the air.

CAJLCZVMf smPBZBBS OV. The monosulphide, Ca^is prapaied: 1. By
decomposing the sulphate with charcoal or coal — 2, By decomposing the sulphate tt a
red heat with carbonic oxide : Ca'SO* + 4C0 - Ca'S -I-4C0'. — 3. By pasaiog sul-
phuretted hydrogen over red-hot lime, water being formed at the same time. It is
white, amorphous, with hepatic taste and alkahne reaction. It is but Bparingly
soluble in water: boiling water decomposes it» yielding sulphydiate and hydrate of
calcium:

Ca«S + H«0 « CaHS + CaHO.

Mixed with water, it is easily decomposed by carbonic acid, yielding carbonate of
calcium and sulphydric acid :

Ca«S ■¥ H»0 + C0« - Ca«CO» + H«S.

The monosulphide, after being heated, shines in the dark ; it was formerly called
Canton*8 Phosphorus,

Distdphide of Calcium^ Ga^, is formed by boiling milk of lime with solphnr and
water, but not long enough to allow the Hme to be completely saturated. The fil-
tered liquid on cooling, deposits crystals, whose composition agrees with the foramla
Ca«S».3H«0. (HerschelL)

Pentastdphide of Calcium, Ca^^ is produced when the monosulphide or hydnta
of calcium is boiled for a considerable time with excess of sulphur. It absorbs oxygeii
with avidity. When hydrate of calcium is used, there is also formed an oxysdphide
represented by the formula Ca»«8H).20BPO, or 6Ca*S.OaK).20H«O. (H. Rose)

SuLFHTDBATB OF CALdUM, CaHS or Ca'S.B?S, is formed, together with the hydrate,
when the monosulphide is repeatedly boiled with water. The best mode of preparing
it is to pass sulphuretted hydrogen through hydrate or sulphide of calcium suspended
in a considerable quantity of water, as long as it is absorbed, stirring well all the
while. The solution thus formed has a sharp, bitter, hepatic taste, an alkaline reaction,
and slight causticity. The compound cannot be separated from it in the solid state,
even by evaporation in vacuo or in hydrogen gas, being resolved, as soon as aystaUi-
sation be^s, into sulphydric acid whi(m escapes, and sulphide of caldmn which
separates in silky prisms. If the solution be boiled down in a retort containing air,
sulphydric acid escapes and oxysulphide of calcium is deposited (p. 716).

Sulph^drate of calcium may be used as a depilatory, and is recommended for this
application by B o t tger (Ann. Ch. Pharm. xxix. 79), in place of sulphide of arsenic. It
may be prepared for the purpose by passing sulphuretted hydrogen into thin mill of
lime till the mass acquires a bluish-grey colour (from admixed sulphide of iron). The
paste thus formed, is laid, to the thickness of a line, on the sui&ce frcan which the
hair is to be removed, and scraped off after a minute or two with a blunt knife, the
hair then coming away with it If it could be produced cheaply enough, it might be
used for removing the hair from hides in the tan-yard.

CJEkXaiO^XM TBU. Btdaciitic carbonate of lime. It is found in pendulous coniol
rods or tubes, mammelated, massive, and in many imitative shapes. Fractnre laradlar.
or divergent fibrous. Lustre silky or pearly. Colours, white of various shades, yeUov,
brown ; rarely green, passing into blue or red. Translucent, semi-hard, very brittle,
Large stalactites are found in the grotto of Antiparos, the Woodman's cave in the
Harz, the cave of Auxelle in France, in the cave of Gastleton in Derbyshire, and
Macalister cave in Skye. They are continually forming by the infiltration oi carb<mated
lime water, through the crevices of the roofs of caverns. Solid masses of stalactite have
been called oriental alabaster. The irregular masses on the bottoms of caves are called
stalagmites. 17-

CA3LCOF3nUUTB. A yellow laminar mineral, from Battenberg in Bhenish
Bavaria, containing, according to Keissig, 34 "01 per cent P^O*; 24*34 Fe^C,
2-96 A1^0«, 14-81 Ca«0, 265 I^'O, and 2066 water ( « 99-27), a composition agreeing
nearly with the formula 2(2Ca*O.I»0»).2Fe*0».P«0»+12aq. It exhibits perfect
cleavage in one direction, and traces in two other directions, oblique to each other bnt
perpendicular to the first, and is therefore probably orthorhombic Specific g»yity
2-52—2-63. Hardness BT 2-5. Fuses readily before the blowpipe to a black, shining,

CALCSPAB.

721

■Mgnetie g^bule. DiflsolTes eatdlj in hydrochloric add. (Handw. d. Chem. ii. [2]
671.)

OAliOSFAX. Calcare&ua Spar. Colette, — The rhombohedral form of carbonate
of ealdom. The primaiy form is an obtuse rhombohedron (Jig. 116), in which the
length of the principal axis to that of the secondaiy axis as 0*8643 to 1, and the
angle of the terminal edges is 106*^ 5'. Of this, there are numerous modifications,
unong which are manj acute and obtuse rhombohedrons, and likewise scalenohedrons,
but aJl distinctly deayable parallel to the feces of the primary rhombohedron. The
primaiT form, -f R, seldom occurs as an unbroken ciystal in pure calcspar, but is the
preTailing form of bitter-spar (CaMgCO*). Most of the forms occur only in combination.
The dimensions of the most frequently occurring rhombohedrons are given in the fol-
lowing table, each of them being the next acuter rhombohedron with relation to the
one aboye, and next ohtuser with relation to that next below it (See C^tstallo-

QBAPHT, HsXAOpiTAL StSTBK.)

Principal

IncUaatlon of feeet

Inclination of facet

axis.

at terminal edges.

at iater«l edges.

-ii

0-2136

166° 2'

230 68'

0-4271

1340 67'

460 3'

+ R

0-8643

IO6O 6'

740 66'

- 2R

1-7086

78« 61'

101° 9'

•1- 4B

3-4172

660 60'

114«> 10'

These formB,aiid combinations of them, are shown in figures 116, 116, 117, 118, 119,
120, 121. Fig. 116 is one of the most common of the rhombohedrons, and is fre-

Fig. 116.

Fig. 117.

Fig, 118.

Fig. 119.

Fig. 120.

Fig. 121.

quently found alone, but still more firequently in combination with the hexagonal prism,
produdng the form seen in Jig. 122. It occurs abundantly at Andreasberg in the Hare,
and in the mines of Derbyshire. Among the scalenohedrons, is the variety called
Dog's-tooth spar, + R» (^. 123), in which the indinationa of the fiices in the terminal
edges are 104® 38' and 144° 24'. It is found in Derbyshire and other localities. It
frequently occurs also in hemitropic twin-crystals (Jig. 124), which may be supposed
to be formed by cutting the ciystal (Jig. 123), in halves by a horizontal plane, and
turning one of the halves througn an angle of 180®.

The n»edfic gravity of the purest crystals of calcspar is 2-721. Hardness - 3, being
intermediate between gypsum and fluorspar. Calcspar when pure is colourless, but
often exhibits various tints of yellow, green, red, brown, and even black, arising from
impuritios. Lustre vitreous. .Translucent more or less, and when transparent, exhibits

Vol. L 3 A

720

CALCIUM : SELENIDE— CALCOFERRT-^

The formation of the compound PH*, may account for the tp^

of the gas. (See Phosphoretted Htdbogen, under P

CA.&CXVMr, BBZiSVISBS OF. A monoaela^';
chloride of calcium with monoselenide of potassiomr /'

A. polyaeUnidey mixed however with selenite'
lime with selenium to a temperature just belo^-
seleniuretted hydrogen, deposits crystals of T' /
to the air.

OA&CZVM, SV&PBZBBS OV.

decomposing the sulphate with charcr

red heat with carbonic oxide : Ca*>^-

phuretted hydrogen over red-hof

white, amorphous, with hepat^

soluble in water : boiling wa^

calcium :

Mixed with water, it i^
calcium and sulphydr

>nty IS best seen tia
lodand spar. These
^ents of larger crystals.

Fig, 124.

The monosulph)
CantorCs Phosr

JHsulpMde
water, but
tered liqp'
Ca«S».3^

Pen

of cs'

wit'

^jfipu occurs in all parts of the world, and is one of the most abundant of

^ ja^^ -^^^ lead-mines of Derbyshire and Cumberland, and of Andreasberg in the

^are noted as affording the most beautiful crystals and the greatest Tuiety of

^ [Respecting the circumstances xmder which carbonate of calcium assumes the

Sffs of calcspar and of arragonit«, see Abka^gonitb, p. 368.]

CA^CWVTm An alluyial form of carbonate of calcium, probably deposited from
^careons springs. It has a yellowish-grey cblour, a dull lustre internally ; a fine-
grained eartny ^cture ; is opaque, and usually marked with impressions of Tegetabie
matter. Its density is nearly the same as that of water. It is soft and easQy cut or
broken. U.

CA]liCnri«llB, or STOITB. The name generally given to all hard ooncretiona, not
bony, formed in the bodies of animals. (See Bbeoabs, Biliary Galouu, Ubctabt
Calouu.)

CA&BSRXTB. A mineral from Nepal, said by Sochting (Deutsche geologi
Gesellschait, ix. 4) to be a kind of garnet.

CA&BBOirZTB. Cupreous Sulphocarbonate of Lead, from LeadhiHs in Scot-
and, consists, according to analyses by Brooke (Ed. PhiL JT.iii. 117), and Thomson
(Phil. Msjg. 1840, p. 402), of 3Pb«SO*.2Pb«CO».Cu»CO». It occurs in prismatic crystals
of the trimetric system, with numerous secondary faces, sometimes large, but usually
minute, and occasionally in branches diverging from a point Specific gravitv « 6*4.
Hardness ■> 2*6 — 3. Colour verdigris- or bluish-green. Streak greenish-white.
Lustre resinous. Translucent. Fracture uneven. £ather brittle, fi is easily re-
duced before the blowpipe, and dissolves partially in nitric acid, with separation of
sulphate of lead.

C AliM W I> U JUiy. A mucilaginous substance extracted from the leaves and flowen
of the common marigold, CaUitdula officinaiia, (G-eiger, IHb$. de CaL off., Heiddber;^
1848.)

CA&ZCO«VRZJr Till Ob The art of dyeing doth (chiefly cotton and linen),
topically ; that is, impressing figures in one or more colours on certain parts of the
cloth, while the rest of the surface is left in its original state. (See Un^s JHctionwry
of Arts, Manufactures, and Mines, i. 491.)

CAXiXFOAXrzar. A bitter principle extracted from C%ibaCa/i/brm«i. (Winckler,
Buchn. Bepert. xxxiL 20.)

See CnreHONA Babx. — OAULAZfl. See Turqucms.

An erieaceous plant, commonly called Ltnff, It

contains, according to Bochleder, a peculiar tannic acid ; the leaves and branches

<3ALLUTANNIC ACID — CAMPH AMIC ACID. 723

^^1^ ** .volatile oD, an acid, probably citric acid, and a small quantity of

-^^ "'the air^dried plant yield, according to Sprengel, 1*96 ash (l)

'^ collected at the end of Angnst) 6-66 per cent water, and

^'26 per cent ash (n.) Nutzinger found in tiie air-dried

<2-87 per cent ash (in.) ; and Thielau found in the flower-

nd-stone, 3'32 per cent aah (it.) The ash contained

,•0 AHO> F««0> Hb<0> CI 80> P*0* SIO*
8-4 tS »r 4-6 4-9 Vt 0-8 19-7

k'^^'V^'%r^ta 67 — 4'9 4-1 — \t 10-» 4«-l

N^-i-'*-* •' "^ "* " "' •

^^^ ^^ ';t •••* >"0 0 8 2-0 3-8

^ ^ - 1-8 1*4 40 327

^ 15-5 6*6 0-6 1*5 4 7 4*1 1*0 6*8 30*9

^^ ^ -jrwXO AOIB. C»<H"0» or O^WO (Rochleder, Ann. Ch. Pharm.

, "^"^ * .;. — ^The tannic acid of Calluna vulgarU. To obtain it^ the alcoholic extract

^ e'^^^ parts of the plant (without the root) is mixed with water ; the liquid filtered

^ a green precipitate of fat, chlorophyll, &c., is precipitated with acetate of lead ; the

washed precipitate treated with very dilute acetic acid, in which it is but partially soluble ;

the filtrate mixed with excess of sub-acetate of lead ; the resulting yellow precipitate

decomposed by sulphuretted hydrogen ; and the filtered liquid evaporated on a chloride

of calcium baUi, in an atmosphere of carbonic anhydride. Callutannic acid then remains

■8 an inodorous amber-coloured mass. This acid does not form anv definite salts with

the alkali-metals, alkaline-earth-metals or silver : for its solutions in alkalis or alkaline

earths quickly absorb oxygen from the air, and oxide of silver is immediately reduced by it

Bochleder has obtained two lead-salts to which he assigns the formula 5Pb O.HO. 20*IJ*C^

and SPb0.2H0,ZC*IP(^, and a stannic salt said to contain 7SnO'.2H0.2C^*H*0^.

Callutannic acid may be used to dye wooL The aqueous solution mixed with stannic
chloride and a few drops of hydrochloric acid, and heated to the boiling point, imparts
to wool mordanted witn alum, a sulphup>yellow to chrome-yellow colour, according to
the strength of the solution and the time of immersion.

OA&KinLAirTSZS. C*<H>«0^— A yellow flocculent substance obtained by
boiling callutannic acid with dilute mineral acids. It is sparinsly soluble in cold
water, easily in hot water and in alcohol. It dissolves also in alkaline liquids, but
- the solution quickly absorbs oxygen, and is then precipitated by dilute acids in red-

brown flocks. (Rochleder.)

Hemichloride of mercury ov mercurous chloride. See Mbbcubt.

lUm mamzm. Mavnasrenn, C"H»"0*. — A resin from Maynas

in South America, obtained from CalophyUum Caloba or C, longifolium. It has the
aspect of common resin, dissolves in alcohol, ether, and oils, both fixed and volatile,
and dystaUises from boiling alcohol jn small transparent colourless prisms of specific
gravity 1*12. It melts at lOfiO C, but does not resolidify till cooled to 90-^. It is
deeomposed by dry distillation ; dissolves with red-brown colour in sulphuric acid,
but is precipitated unaltered by water ; and when heated with nitric acid of specific
eravity 1*32, is said to yield butyric and oxalic acids, together with another acid which
does not precipitate calcium-salts. With chromic acid, it is said to yield carbonic
and formic adds. It dissolves in alkalis. (Levy, Compt rend, xviii. 242.)

1?il^^W*F' ■'■'■ifc- An instrument for the estimation of latent heat, specific
heat, heat of combustion, &c (See Hbat.)

OAAOSZMOTOX* A voltaic arrangement consisting of one pair or a few pairs
of very large plates, used chiefly for producing considerable heat enecUu (See ^.bc-

TRIdTT.)

CAXMVMOMMAMYTWL Shepard's name for a variety of heavy spar from
Shoharie in New York, mixed with carbonate of strontium and calcium. (SilL Am. J.
* 161.)

■• A mineral from Haddam and Mittletown in Connecticut,
crystallised in square prisms of specific gravity 4*34, hardness 6*6. Probably an
altered siroon. (She par d, SilL Am. J. [2] xii. 210.)

OlAT WWBXMm A resin from MoruM indiea.

The leaves contain tannin, which is sparingly
precipitated by gelatin, abundantly by lead and iron salts : they do not contain theine.
(Stenhouse.)

CAXFBACHT ISITOOB. See Logwood.

CAUVBAMZO AOZD and CAMFXAMUMI. See Campuobamic Aged and
Cakphobamidb.

3 A 2

724 C AMPHENE — C AMPHENES.

I. This term ia used in rarious ways; sometimes as a generic name
for the hydrocarbons isomeric or polymeric with oil of turpentine, Bometimes as the
name of the radicle of camphor (C*'H") and its allied compounds. By Dumas and
Berthelot, it has been apphed especially to the hydrocarbon, also containing C**H**,
obtained by the action of alkalis on hydrochlorate of torpentine-oil. Laurent ifpiied
the same appellation to the radicle of oil of cloves, eugenin, &e.

Chlorinated and brominated derivatives of camphene, e. g. C'E^Kl* and 0*W^^
are obtained by the action of chlorine or bromine on oil turpentine and its isomen.
jLmonochlorocamiphtMy C**H^1, and a dicktoride of camphene, C'*H**CP, are prodnoed
by the action of pentachloride of phosphorus on camphor (see p. 728).

CAMFKBinw or Terebenes, The generic name for the volatile oils or hydro-
carbons C^H*", isomeric or polymeric with ouof turpentine. Most of them are iaomerie
and consist of G*'H'*, e. g. oil of turpentine, oil of lemons, oil of juniper, caoutcfain,
&c. ; some, as colophene, appear to consist of C"H".

Many camphenes exist ready formed in plants, as the oils of juniper, lemon, and
turpentine ; they are often contained in the natural oils associated with oxygenated
compounds, and may be separated therefrom by fractional distillation, as carvenefrom
oil of caraway, bomeene or valerene from oil of valerian, &c MaJiy are proditced
from oxygenated compounds containing 0"H*" + water, by the action of phosphoric
anhydride {e. g, bomeene from, bomeol, cinsebene from wormseed-oil, &c) Othenare
formed from oxygenated oils by the action of hydrate of potassium (oil of sage and
others) ; some by dry distillation, as oil of amber, caoutchin, &c.

AH the camphenes are liquid at ordinary temperatures (except Berthelot'a camphene,
which is a solid melting at 46*' C.) ; they have for the most part a density of 0*8 to
0'9 (oil of parsley is the only one heavier than water, specific ^vity = 1*0 to \'\\
and boil between 156° and 165° C. ; their observed vapour-density varies from 4*6 to
4*8, the formula C**H" calculated for 2 vol. giving a thoretical density of 4*7. A few
only boil at higher points, viz. oil of copaiba at 250° C. ; petrolene at 280° ; colo-
phene at about 310°; cinsphene at nearly 320° metaterebene about 360°. The
observed vapour density of carvene is 6*1, of tolene 6*7, of petrolene 9*4, of oolopheDe
11*1 *, the formula C**ri.** calculated for 2 voL requires 9*4.

Camphenes are distinguished one from the other by their odours, which in aome, as
oil of lemon, are very fragrant, in others, as in oil of copaiba, extremely disagreeable ;
also by their action on polarised light. All natural camphenea poaaeGs tl^ optical
rotatory power in a sreater or less degree, some turning the plane of polariaation to the
right, otners to the left; but even in the same oil, the strength and direction of the
rotatory power vary according to the temperature and othej circumstances.

Camphenes readily absorb oxygen and convert it into osone. Iodine for the most
part decomposes them readily and with evolution of heat, sometimes even with ali^t
explosion, the iodine taking the place of a portion of the hydrogen ; this reaction
serves to detect the admixture of camphenes, oil of turpentine, for example, irith other
volatile oils. Chlorine and bromine act in a similar manner.

Camphenes treated with broTnine and foattr are easily conTerted into brominated
oils (Gr. Williams, PhiL Mag. [4] v. 636). According to Chautard (Compt rend.
•g-gTiiv 671 ; xxxiv. 485), camphenes distilled with tDoUr and bromide or ckioride of
lime^ yield, amongst other products, bromoform or chloroform.

Most camphenes unite with hydrochloric acittf forming either liquid or aystaSiaed
compounds, frequently having the composition C"»H".HC1 or C"H".2HC1; tiie«
compounds, called artificial camphors, have the same rotatory power as the oils from
which they are produced. Similar compounds are formed with hydrobmak and
hydriodic acid.

Natural camphenes treated with acids, especially with strona nUphurie add, gene*
rally undereo an alteration of molecular arrangement without cnange of chemiol con-
stitution, uie odour being for the most part greatly altered, sometimes also the
density and boiling point ; but the most characteristic alteration is the loss of optical
rotatory power. A camphene often yields several isomeric modifications by trpsfaneot
with dmerent acids, or by repeated treatment with the same acid. The new camphenes
thus produced are called camphenes of the second order, or sometunes cam-
pherenes. Another class, called camphenes of the third order,or sometimes
camphilenes, are obtained by the action of lime or baryta at high temperatures
on the hydrochlorates of other camphenes; these are also optically inactiTe; and
generally differ greatly in odour from the original camphenes, but oftein exhibit neaik
the same specific gravity and boiling point The camphenes of the second and third
orders are decomposed bv chlorine, bromine, and iodine, and form liquid or aystsUued
eompounds with hydrochloric, hydrobromic, and hvdriodic acids.

The camphenes are a very numerous dass of bodies; the principal of them are:

CAMPHERENES— CAMPHINR 725

Oil of bergamot Gaultherilene Oil of pepper

Bomeene Oil of gomart Petrolene

Carvene Oil of hops Oil of savin

Caoutcbin Oil of I'uniper Tbjmene

Cixuebene Oil of lemon Tolene

Nentral oil of cloves Oil of orange Oil of turpentine

Oil of copaiba Oil of parsley
Oil of elemi

For details relating to specific gravitv, boiling pointy vapour-density, and rotatoiy
power, see the several oils« (Handw. cL Chem. iL [2] 69 i ; Gm. xiv. 271 — 322 and
3^6—404.)

CAMVBX&SnS^ Campbenes of the second order (p. 724).

OAMVBBRTXi or OABIVBBBIXA. A name applied by Laurent to the im-
pure camphorone (^. V.) which he obtained from camphorate of calcium.

CABnrano JkOtDm C^'H^K)* ? — A j^roduct obtained, together with bomeol, by
heating camphor with alcoholic soda-solution in sealed tubes to 170^ — 190^ C.

2C"H"0 + HK) - C»«H"0 + C"H'«0«.

Camphor. Bomeol. Campblc acid.

On neutralising the product with sulphuric add, dissolving out the camphate of sodium
with alcohol, evaporating and again adding sulphuric acid, the camphic acid separates
as a nearly solid, coloured mass, heavier than water, sparingly soluble therein, easily
soluble in alcohoL It is decomposed by nitric acid. The potassium and sodium-salts
are nearly insoluble in strong alkaline levs ; they precipitate the salts of copper, iron,
lead, silver, and zinc, not those of the alkaline-earth metals ; all the precipitates are
soluble in a large quantity of water. (Berthelot, Ann. Ch. Phys. [3J Ivi 94.)

CABKVSZIIBB. This term was applied by Laurent to nuclei in which the com-
bustible hydrogen is replaced by oxygen.

CAMVBX&Brai Deville's name for the camphene obtained by treating hydro-
chlorate of turpentine-oil with Ume. Campbenes of the third order (p. 724) are some-
times called camphilenes.

CAIKFSZIKZDB. See CAUPHOBiinDB.

CAMPBZV. C»H" or C»H"? (Clans, J. pr. Chem. xxv. 262; Gm. xiv. 448.)
— ^Formed, together with campho-creoeote, colophene, and campho-resin, by triturating
camphor with an equal weight of iodine, and distilling. A black mass then remains
containing campho-resin, and the distillate separates on standing, into a watery layer
containing hvdriodic add, and an upper oily layer containing camphin, campho-creo-
aote, and colophene. To obtain the camphin, the mixture is agitated with mercury,
to remove iodme, then rectified per se, and the most volatile portion shaken up with
potash-ley, and repeatedly rectified over potash-lime to remove iodine ; it may also be
need from the last traces of iodine by setting it aside with potassium and rectifying.

Camphin is a thin colourless oil of specific gravity 0'827 at 25^ C, and boiling at
167 — 170^ undera pressureof 28 inches. It has a pleasant odour, like that of oil of mace,
somewhat also like turpentine. It gave by analysis 86*06 per cent C and 12'79 H ;
the formula C>«H'* requires 86*96 C and 13*04 H, while C*H'* requir<« 87'10 C and
12*90 H. Q«rhardt regarded it as impure cymene, C**H'^ (89*6 C and 10*5 H).

Camphin burns with a bright but veiy smoky fiame. It dissolves in dtcohoi, ether,
cU of turpentine, and rock'Ou; but not in wat^, weak alcohol, potash, or dilute adds,
or even in strong hydrochloric add. It absorbs a small quantity of hydrochloric acid
ga». It is but slightly attacked b^ stUphuric acid. Nitric acid, with, aid of heat^
converts it into a yeUow nitrogemsed oil, smelling like cinnamon, or by prolonged
heating, into a red oil soluble in potash. Pentachloride of antimony converts it into
a resin.

Camphin is readily decomposed by chlorine and bromine, yielding etthstittUion-prO'
ducts. The chlorocamphins are transparent, colourless, oily bi^ies, which, when
treated with alcoholic potash, yield chloride of potassium and a chlorinated oil having
an agreeable odour. Claus obtained two compoimds, which he regarded as CH"C1'
«ndC»H"a«.

OAMPBZVB This term is applied in commerce to purified oil of turpentine,
obtained by carefully distilling the oil over quick lime, sometimes also rectifying it
over dry chloride of lime ; in this manner it is obtained quite free from resm. In
some cases, the oil is treated with sulphuric add previous to rectification. This puri-
fled turpentine-oil is much used for ouming in lamps, giving a veiy brilliant Hffht
Ik 18 however very apt to smoke, and must therefore be burnt in lamps of peciuiar
construction, with very strong draught. A solution of camphine in three times its

3 A 3

726 CAMPHOCREOSOTE— CAMPHOLIC ACID.

volume of alcohol of specific gravity 0'820, sometimes with addition of a little ether to
ensure more complete solution, is also used as an illuminating material, and may be
burned in ordinaiy lamps with aigand burners.

OAIIFBOC^XBOBOTB. A product of the decomposition of camphor by iodine
at high temperatures ; according to Schweizer, it is probably identiau with carTa-
crol (j. tr.)

OAMVBOIiBV. Dumas' name for the hydrocarbon G'*H'\ obtained from cam-
phor by the action of phosphoric anhydride ; it is identical with cy mene (9. «.)

O AMVHO&* This name was applied by Qeihardt to the camphor of the Laoraeeas ;

but Berth elot has recently applied it {Ajin. Ch. Phys. [3] ItL 78), to Bomeol or
Borneo-camphor, which he regards as the alcohol of a series in which common camphor
is the aldehyde, thus :

EihyU««rlat. Cuopliyl-MriBi.

Ethyl-alcohol, C«HH) Camphol, C»«H»«0

Aldehyde, C»H*0 Camphor, C"'H»H)

Acetic acid, C«H*0« Camphic acid, C"H>K)*

Chloride of ethyl, C*E*Ci Chloride of camphyl, C*m"Ci

Ethylene, C'H* Camphene, C"ff«

Camphol is produced by treating camphor with alcoholic potash (p. 626), just as ben-
zylic alcohol is produced from benzoic aldehyde (p. 578). It is also formed by Hiarillmg
amber with \ of its weight of potash and a large quantity of water.

From later experiments by Berthelot and Buignet (Compt rend. L 606), it
appears that the seyeral bodies to which the name camphol has been applied, are iso-
meric but not identical, being especially distinguished by their different rotatory power,
which in camphol from common camphor ■> + 44'9^ ; in natural camphor or bomeol,
a +33 '4^; in camphol from amb«r » + 4*6^; while in IsTO-iotatozy bomeol, or
camphol obtained from madder-camphor (p. 626), it is — 33*4°.

According to Berthelot, camphol heated with acids unites with tfaem, like all
alcohols, with elimination of water. The resulting compound ethecB may be purified
by remoying the excess of acid with slaked lime and ether, and distilling off the excess
of camphol by prolonged heatiiijg at 150^C. They are cobuiless, neutral, solubie in
alcohol and ether; some are liquids, others ciystalline; the latter melt at a lower
temperature than camphol. Alkalis decompose them into acid and camphol, the latter
exhibiting its original properties. Befisoate of camphol, C"H**0« « CH*(C»«H»^0*
is a neutral, colourless, inodorous oH-^Sbkaraie o/camphol,C^E.'*0^ = C**H»(C*»H")C)*,
is colourless, inodorous, viscid, solidifying after a while in a crystalline mass. — Chloride
of canvphyU C"H"C1, obtained by heating camphol (bomeol) with strong hydrochloric
acid to 100° C. in a sealed tube for 8 or 10 hours, and purified by washing with
dilute potash and crystallisation from alcoho^ has the aspect, odour, and empirical
composition of hydrochlorate of turpentine-oil or artificial camphor (C'*H'*.HC1\
but turns the plane of polarisation to the left, somewhat less stronsly uian bomeoL
Heated to 180°C. with alcoholic soda-solution, it yields chloride of sodium and bomeoL
By this and by its rotatory power, it is sufficiently distinguished from hydrochlorate of
turpentine-oil (Handw. d. Chem. 2*« Aufl. ii. [2] 695.)

CAMIPVOl^BVa. C*H'*. A liquid hydrocarbon obtained by diwtilHng camphoiic
acid with phosphoric anhydride. Vapour^ensity 4*353. (Delalande.)

CASIVBOUCC ACID. Bomenie amd. C^K'H)* - C**H*^O.H.O.~Prodiieed Ij
the action of hydfate of potassium on camphor. The quantity found under the ordi-
nary atmospheric pressure is but small : but if the camphor be enclosed, together with
potash-lime, in a sealed combustion tube of the ordinary dimensions, and its vapour
made to pass several times over the heated potash-lime, about 5 or 6 grammes of
purified acid may be obtained from each tube. To isolate the acid, the contents of
the tube are digested in water, and the solution decomposed by a stronger add. The
camphoiic acid is then deposited as a crystalline mass, which mav be pmrified by dis-
tillation. It is white, and crystallises weU from a mixture of alcohol and ether ; melts
at 50° C. ; boils without alteration towards 250°. Insoluble in water, but imparts to
it an aromatic odour. Vapour-density 6*058. Distilled with phosphoric anhydride,
it yields campholene, carbonic oxide being probably evolved at the same time :

C»*H»«0« - CO + HK) + C»H".

It is monobasic. .The etUcium-talt, C**H"CaO^ is a snow-white ctyetalline powder
obtained by pouring chloride of calcium into a neariy boiling solution of the acid in
excess of ammonia. By dry distillation, it yields an oily body called camphoUmet
C'^H'K) :

2C"H»'CaO« - Ca«CO« + C"H»*0.

CAMPHONE— CAMPHOR. 727

Campholate oftilver, obtained bj decomposing the neutral ammonium-salt with nitrate
of silTer, forms cordy flakes. (Delalande, Ann. Ch. Phys. [3] i 120.)

CAMVHOn* Byn, of Cthhnb.

C AMTHOamTH 1 fcIO AOZB* Camphorate of methyl and hydrogen. (See
Cakfhobic Acid, p. 733.)

CSAMVBOB. C**H><0. (6m. ziy. 358; Gerh. iii. 621).— A cr^talline substanoe
obtained from the Laurtts camphora and other plants in which it exists ready formed.
There are three modifications of it, identical in composition and chemical properties,
but differing in their action on polarised Ught, viz. dcxtro-campkoTy which turns the
plane of pokrisation to the right, kBtfo-camphorf which turns it to the left^ and inaciive
campkoTf which has no action on polarised light,

a. Dextro^amphor, Laurel or common camphor. This Tariety exists in the wood
and bark of several trees of the Lauraceous order, chiefly in the Laurtu campkora, a
tree indigenous in Japan, Jara, Sumatra, and Borneo. The process of extraction is
Teiy simple. In China and Japan, the wood, sawn into biUets, is distilled with water
in a kettle covered with an earthen capital lined with rice-straw, on which the crystals
of camphor are deposited, being carried up by the aqueous vapour. The crude
camphor thus obtained is exported to Europe, where it is purified by sublimation. In
Sumatra and Borneo, the wood is split with wedges, and ike camphor, which is found
between the fibres in tears and crystais, is extracted; a single tree sometimes yields
as much as twenty pounda

Dextro-camphor is also produced artificially by the action of nitric acid on bomeol
or camphor of Borneo, C"H**0 (pp. 626, 726).

Camphor crystallises by sublimation, or by slow deposition fix>m an alcoholic solution,
in octahedrons or segments of octahedrons. It is white and semi-transparent, like ice,
rather tough, sectile, and not easily reduced to powder without the aid of a litUe
idcohol. . It melts at 17 6° C. and boils at 204^ C. evaporating completely away without
alteration. Its specific gravity varies firom 0*986 to 0*996. Vapour-density *» 6*317
(Dumas). Water dissolves ^^ pt of camphor, and thereby acquires its peculiar
smell and taste. When small bits of camphor are thrown into water in a broad basin,
they revolve and move about with more or less velocity, in proportion to their small-
ness. These rotations are attributed to the force exerted by the vapours rapidly ex-
haled firom the camphor on the surface of the water ; but the explanation is not veir
satisfactory. If a pin-point slichtly smeared with oil be dipped into the water, all
the motions cease instantlv, and the particles of camphor are repelled from the pin-i^t
by the spreading film, oi oiL The dispersion of tne camphor-vapour is made very
striking by the repulsion of the water on a moistened saucer from me points on which
bits of this substance are laid.

Laurel-camphor is soluble in alcohol, ether, acetone, acetic acid, wood-spirit, sul-
phide of carbon, and oils. 100 pts. of alcohol of specific gravity 0*806 dissolve 120 pts^
of camphor. It is thrown down almost entirely in fiocks by the addition of water.
Camphor augments in a remarkable degree the solubility of corrosive sublimate in
spirit of wine.

The optical rotatory power of tlie alcoholic solution of camphor, is 47 4 for a length
of 100 millimetres. According toArndtsen (Ann. Ch. Phys. [2] liv. 403), it increases
wit^ the refran^bility of the rays much more quickly than is ooserved in any other
substance. Solid camphor does not exhibit any rotatoiy power.

Beaethns. — 1. Camphor, when set on fire in the air, bums with a smoky fiame, pro-
ducing water and carbonic acid. Spongy ptaHnttrnt or a coil of fine platinum wire laid
on camphor, begins to glow when the camphor is set on fire, and continues glowing
after the fiame is blown out Camphor is set on fire by ehlorochromio acid, — 2. By
prolonged boiling with nitrie acid or permanganate of potiusium, it is converted into
camphoric acid (p. 730).— 3. Heated with strong sulphwric acid to 100® C. for 12 — 13
hours, it is converted into camphrene, C'H'^O, with evolution of sulphurous anhydride
and separation of charcoal (Cnautard, Compt. rend. xliv. 66). According to Dela*
lande (Instit 1839, pw 3991 camphor heated with excess of strong sulphuric acid, is
converted into a volatile oil, which has the chemical properties and composition of
common camphor, but less rotatory power, and when heated with potash to nearly
200^ C. is converted into a solid camphor, whose rotatoiy power is mtermediate be-
tween that of common camphor and that of the oily camphor. Gerhardt supposed that
the oil obtained by Belalande was cymene ; according to Chautard, it is camphrene
containing camphor. — 4. Camphor- vi^ur passed through a red-hot glaaa or porcelain
iubCf yields a combustible gas and an oil soluble in alcohol (Saussure). — 6. When
the vapour of camphor is passed over red-hot iron^ an oily Uouid is produced, contain-
inff naphthalene and a nydrocarbon boilina at 140® C. ana having the composition
ofbensene (D'Arcet^ Ann. Ch. Phys. [2] Ixvi. 110). — 6. Camphor distilled with

3a 4

728 CAMPHOR

2 pta. alumina or eU^, is nsolred into caibomc anhydride, oabowtted bjdragiii,
empyrenniatic oil, and a lesidue of chaivoaL — 7. Distilled vith photphorie ^nHufdride,
it is reeolTed into water and cym ene, C**H'^ (Delalande, Ann. Ch. Fhjs. [3] 1 368).
Heated with concentrated phosphoric acid, it Tolatiliaes for the most part Trndecom-
pooed. It is also resolxed into water and miiene hy distillation with eibride of sine.
— 8. Camphor-Tapoar passed over red-hot &ne, yields camphrone, C"ll*H), an oily
liquid boiling at 75^ C. At a "veiy hrigfat red heat, thisprodnct ia restored into cvtwme
oxide, carim retted hydrogen, and ni^hthalene (Fr^my, Ann. Ch. Fhys. liz. 16)l—
9. When the raponr is paned orer heated poiask4ime, under pressore, campholate
of potassium, C^'K'^O' is produced (Delalande^ p. 726).— 10. Camphor heated
to 180<>— 200O C. with aleokoHe potash or soda, is converted into borneol (Berthe-
lot, pp. 626, 726). — 11. When camphor is triturated with iodine^ and the mixture is
distilled, a dark-coloored oily liquid passes orer, containing camphin, campbo-
creosote^ and colophene, and a blackish residue is left; containing campho-resin
(Clauss, p. 725). — 12. Bromine unites with camphor, fanning an instable bromide of
camphor, C**H*^3r, which is oystalline, and is decomposed by heatt by contact with
air, and by the action of ammonia. — 13. Chlorine exerts but little action on cunpihor,
eren in sunshine. — 14. With pentachloride of phosphorus, camphor yields oiTcUoride
of phosphorus, and a eiystalline substance, C*H'*C1*, haring the aspect of aitifidal
camphor (hydrochlorate of turpentine-oil). It remains disscuTed in the oxydilonde,
and may be precipitated by water (Gerhardt) :

C»H^ + PC1» = P0C1« + C^ff-CP.

This compound yields by repeated diy distillation, a chlorinated oil eonmsting of
C»H«C1. (Gerhardt)

According to Pfaundler (Ann. Ch. Pharm. cxr. 29% 1 at camphor heated to abont
110° C. with 1 at PCI*, yields hydrodiloric add, oxydiloride of phosphonia, and eklo-
rocamphene, C'*H*^C1, which is a white, soft, erystalline substance, haring an odour
of camphor. Its index of refraction is 1*49327. It is insoluble in water, but diaBoIm
in 3*5 ptsL of 87 per cent aleohol at 14^ C, forming an <^>ticaUy inactire sohition. The
crystals volatilise rather quickly at orduiaiy temperatures, melt at about 60^0., and
then sublime, decomposing at h^^her temperatures. With 2 at pentaefaloride of {^os-
phorus to 1 at camjuior, chloride of eamphene, C**H^*C1', is obtained in white
crystals, resembling the preceding in aspect and in odour, but softer, and baring an
index of rpfraetion «> 1*60553. It dissolves in 4*95 pts. of 87 per cent aloohot at
14° C, forming a solution possessing laevo-rotatoiy power. The crystals Tolatilne
rather quickly at ordinary ttanperatures, and melt with partial sublimation near 7(fi.
— 15. 11. chlorine be paned through the solution of camphor in irichloride of phos-
phorus, various substitution-products are formed, aooording to the time for whioi the
action of the chlorine is continued. Tetrachloroeamphor, C'*H*K3^, has been
isolated, though not quite pure. If the action be continued for a long time, and assisted
by heatt a <H>lourie8s product is at length obtained, having the aspect of white wax,
and consisting of sexchloro-eamphor, C**£[**C1*0 (Claua, J. pr. Chem. xxr. 259).
— 16. When camphor is heated with mercuric chloride^ hydrochloric add is erolved,
together with an odour of turpentine, and a carbonaceous mass containing calomel
remaina — 17. Pentachloride of antimony attacks cainphor strongly, giringoff hydio-
ehloric acid, and forming a resinous substance. — 18. Hydrochloric iu:id gas is absorbed
by camphor in quantities varying according to pressure and temperature, as shown by
the following table, which gives the quantity of the gas (HCl) absorbed bj 1(H) pta
camphor, at the temperature t and barometric pressure 5:

t 240 20® 18*50 18.50 130 90 70 70 30 30(3.

5 747 740 735 744 320 288 270 740 232 738 nun.
Ha 19*0 20*0 20*4 20*5 15*3 15*8 16-3 240 17*0 26*0

At a certain low pressure, camphor no longer absorbs hydrochloric add gas. This
pressure varies with the temperature, being 220 mm. at 12^; 340 mm. atUH);
300 mm, at 20<^; and 423 mm. at 24^ (Bineau, Ann. Ch. Phys. [3] xxiv. SSS).—
19. Sulphurous anhydride is quickly absorbed by camphor, forming a colourless liquid,
which IS heavier than water, dissolves iodine and camphor, and when saturated with
camphor, contains 4 pts. camphor to 1 pt SO*. It gives off sulphurous snhydride erea
at ordinary temperatures. The <pantitieB absoi1>ed by 100 pts. camphor at Taiioos
pressures and temperatures, are given in the following tables (Bineau, loe, at):

t 240 240 15-5« 15-5° 12*50 1250 20 80 40 40 2^ 2«C.
b 524 745 355 744 529 727 304 682 490 720 649 650
80*25*5 35*4 28*0 47*6 37*3 50*5 33*0 57*4 460 73*6 484 72-0

CAMPHOR, ARTIFICIAL^ CAMPHORAMIC ACID. 729

At 700 mm. preflsure, 100 pts. camphor absorb of 80* :

at 240 200 16-5^ 140 12-60 lO® S® 40 C.
33-1 37-7 44-3 468 48*9 540 58-6 70*5

— ^20. Camphor absorbs the Tapour of peroxide of nitrogen (or nitric oxide in presence
of air), forming a liquid which is decomposed bj water, dissolves camphor, and
when saturated therewith at 18^0., contains 100 camphor to 26 — 27 peroxide of
nitrogen. (Bine an.)

i9. LmoO'Camphor, — When the essential oil of feyerfew (Pyrethrum parthenium)
is fractionally distilled, and the portion which distils between 200° and 220° G. is col-
lected apart, it deposits on cooling a large quantity of camphor, similar in all respects
to common camphor, excepting in its opticsd rotatory power, which is equal and oppo-
site, Tiz. [a] s> —47*4 for a kngth of 100 millimetres. The camphor treated with
nitric acid yields Isero-camphoric acid. (Dessaignes and Chautard, J. Pharm. [3]
xiii. 241 ; Chautard, Compt rend, xxxvii. 166.)

y. Inactive Camphor. — ^Accordinff to Proust, the essential oils of sereral labiate
plants, Tiz. rosemary, marioram, lavender, and sa^, often deposit a substance like
camphor. Lavender camphor hiu9 the same composition as laurel camphor, but is with-
out action on prolonged light. (Dumas, Ann. Ch. Phys. xiii. 275; Biot^ Compt.
rend. xv. 710.)

Bodies resembling camphor but of undetermined modification, have been obtained
by the action of nitric acid on the essential oils of tansfy, semen-contra, valerian, and
sage. Lastly, when amber is treated with nitric add, it yields a distillate containing
camphor, which may be extracted by saturating with carbonate of potassium and
igniting with etiier.

CAMVBOX, AMTBPXCUkJ^ Syn. with Htdbochloratb of TxrBPBMnME-oiL.

(See TUBPENTINB.)

CAsmos or BOBarao. See Bobmbol.

CAMVHOBf OlXi OV« When the branches of the camphor-tree {Laurus cam-

?hora) are distilled with water, a volatile oil passes over together with camphor,
'his oil is mobile, colourless, has a strong odour of camphor and considerable dextro-
rotatory power, and is resolved by fractional distillation into an oil boiling at 180° C.
and a portion boUinff at 205° ; the latter appears to be essentially the same as common
camphor. The oil ooiUng at 180° is very much like oil of lemon, possesses strong
dextro-rotatory power, and forms with hydrochloric acid a crystalline compound, which
melts at 42°, and gives by analysis 57*34 per cent C, 8*6 H, and 33*83 CI, agreeing
with the formula C»«H".2HC1. (Lallemand, Ann. Ch. Phjs. Ivii. 404.)

The wood of Dryahalanope Camphora, from which bomeol is obtained, likewise yields
by boiling with water, a camphor oil, separable by fractional distillation into two vola-
tile oils, having the composition C"H", one boilins between 180° and 190° C, the
other at about 260°, and a resin, C"H*^* (?), which melts at a temperature a little
above 100° (Lallemand). It is remarkable that the oil of Bryabalanops examined
by Lallemand, did not contain bomeol, and that even the most volatile portion of it
had a boiling point much higher than that of bomeene (p. 626). The subject requires
further examination. (See Dbtabalanops.)

C iLOXB.

C'.ff'NO' - N.H«.(C»H"OTj 0. (L.iirent,

Compt chim. 1845, pi 147.)— Derived fiom acid camphorate of ammonium by elimi-
nation of 1 at water:

C»»H»(NH*)0« - H«0 « C»*H"NO«.

The ammonium-salt of this acid is produced by the action of ammonia on a boiling
saturated solution of camphoric anhydride (C"H"0« + 2NH» « C"H"(NH*)NO»), and
on treating the solution of this salt with hydrochloric acid and evaporating, campho-
ramic add is deposited in crystals, which may be purified by solution in dilute alcohol
and spontaneous evaporation. It is then obtained in splendid crystals, belon^g to
the tnmetric sjrstem, 00 1^ 00 . ool* cx) . P 00, with ooP and P subordinate. Indination
of the&ces: Poo : Poo «114°30'; too : oof^oo » 122° 45'; Poo : P - 155°; oeFoo :
ooP » 131° 40'. It is colourless, moderately soluble in hot water, less in cold ; more
easily in alcohol. A small quantity melted on a plate of ^lass, partly crystallises in
rhoml 9f whOe the rest solidifies slowly into a transparent vitreous mass.

The add is monobasic Its ammonium-eait, C»»H"(NH«)NO» + H«0, orstallises
well, has a slightly acid, bitter, transient taste, and melts at 100° C. It differs from
neutral camphorate of ammonium, with which, in the hydrated state, it agrees in
«onipoiiition, by not precipitating the salte of lead, copper, or silver. The Ifod-eaJt^
C»*ll"PbN()*, is deposited in small cr}*stals, on mixing the concentrated boiling alco-

730 CAMPHORANILIC ACID— CAMPHORIC ACID.

holic solutions of camphoramate of ammoniam and acetate of lead, the foimer in ezoesa,
and leaving the liquid to cool. The silver-salty C'^H'^AgNO, is obtained as a trans-
parent jelly, composed of minute crystals, on mixing the boiling concentrated aohitiaDs
of camphoramate of ammonium and nitrate of silr^, and leaving the liquid to cooL

CA.BKFBOBAWXIiXG ACSXII. See pHBirTL-CAMFHORAMTO AcD>.

OAMFKOKAJnBB. C"H>"N«0» - N«.H*.(C»»H'*07'.— When a conwit of
ammonia-gas is passed inta the middle of a solution of camphorio anhydride in abso-
lute alcohol, the liquid becomes heated, and yields by evaporation a syrupy mass, in-
soluble in water, which is probably camphoramide. It is not decomposed in the oold
by hydrochloric acid ; but when treated with potash, it gives off ammonia, and forms
oamphorate of potassium. (Laurent, Rev. scient. z. 123.)

CaAMPBOSBSXV. The name given by Glaus to the non-yolatQe product of the
action of iodine on camphor (p. 728).

CAMPHOSXO AOXB. C'«H>*0« - C>«Hi«0< H*.0<. (Gm. sir. 465 ; Geili. liL

700.) — There are three modifications of this acid, corresponding to those of camf^ior,
viz. dextro-rotatory, Ustfo-rotatory, and inactive,

Dextro-camphoric or ordinary Camphoric acid. — ^Thisacidwaadiacoreredby
K 0 8 ega rten {l)iss. de camphora et partibusqtus earn eottsiUuant, Gottingen, 1786), and
particularly studied by Laurent (Ann. On. Phys. bdii 207; ConipL Chim. 1846,
p. 141), Malaguti (Ann. Ch. Phys. Ixiv. 161), and Liebig (Ann. Ch. Pharm. xxiL
60). To prepare it, common camphor is heated in a retort wim ten times its weight
of strong nitric acid, the liquid being cohobated several times, and the acid renewed.
On evaporating and cooling t&e residual liquid, the camphoric acid dystallisea out, and
may be punfi^ by dissolving it in carbonate of potassimn, precipitating with nitric
acid, and recrystallising several times.

Oamphoric acid forms colourless transparent scales or needles, which melt at 70° 0.,
and taste sour and bitter at the same time. It is sparingly soluble in cold water, more
readily in boiHng water ; eaaily also in alcohol, ether, and &tty oils. Aceording to
Brandes, it requires for solution, 88*8 pts, of water at 12*6^0., and 8*6 pta. at 96-26o.
Molecular rotatory power of the solution [a] » + 38*876 ; this power diminishes con-
siderably on saturating the acid with an aUcaU.

It gives an abundant precipitate with neutral acetate of lead. By dry distillation
it is resolved into water and camphoric anhydride, leaving only a small film of charooaL
It dissolves without alteration in strong nitric and sulphuric add.

fi. La vo-c amphoric Acid. — Obtained by the action of nitric add on the caanphor
of feverfew (p. 729), has the same composition and chemical properties as dextro-cam-
phoric acid, and rotates the plane of polarisation, by exactly the same amount, to the
left (Chautard, Compt. rend, xzxvii. 166.)

7. Inaoti ve Camphoric Acid, or Paracamphoric Add, is produced by mixing equal
weights of dextro- and Isevo-camphorie add. It agrees with ordinary camphonc add
in most of its properties, but has no action on polarised light. (Ghautar d.)

Oamphobatbs. — Oamphoric add is dibadc, the formula of a neutral eamphorate
being 0"'H*^M'0\ The camphorates are odourless, and have a slightly bitter tastCL
Most of them are sparingly soluble in water. They are deeompo«ed by sulphuric,
hydrochloric, and nitric add.

Camphorates of Ammonium. — The neutral salt, 0"H'*(NH*)H)*, is obtained by
passing a current of dry ammonia-gas over camphoric add, and expodng the product
to a current of dry air. It is very soluble in water, and has a slight add reaeticMi, but
no dedded taste. An acid ammonium-salt is obtained in small prisms, melting above
100° 0. by throwing crystals of acid carbonate of ammonium into a boiling solution of
camphoric add. When dried at 100° in a current of air, they lose 19 per cent, of
water. They contain, according to Malaguti, 63*67 per cent carbon, 8*97 hydrogen,'
and 8*6 nitron, whence he deduces the formula 30^•H>*0^4NH' + 9H*0, that is to
say, a compound of 1 at. neutral eamphorate and 2 at add eamphorate of ammonium;
but, accormng to G^hardt, the salt is an acid eamphorate, 0>*H^NH^)0 + 3HK), the
formula of which requires 66*3 0, 8*7 H, 6*6 N, and 19*9 per cent water.

Camphorate of Potassium. 0**H'^K'0\ — Orystallises m laige nacreous scales when
prepared with hydrated camphoric add, and in small delicate needles when prepared by
dissolving camphoric anhydride in potash. According to Buehols and &«ulJon-
Lagrange, it is but sparingly soluble in water, whereas Brandes states that it is very
dehquescent, and dissolves in a very small quantity of water (probably the sparingly
soluble salt was an acid salt). Oamphorate of sodium forms limpid, CQnfbsed, slightly
efflorescent crystals, soluble in 200 pts. of cold and 8 pts. of boiling water ; also in
alcohol.

The hariumrsalt forms laminae or needles soluble in 600 pts. of boiling water; ac-
cording to Brandes, in 1*8 pts. water at 19*9*^ 0.

CAMPHORIC ANHYDRIDE— CAMPHORIC ETHERS. 731

The sironUum'talt forms oolonrlesa UmiiUB mach more soluble than the barium-
salt

Caleium-Mtlt — The neutral salt forms a non-czystalline mass, neutral to test-paper,
nearly insoluble in cold water, soluble in 200 pts. of boiling water, insoluble in alcohol,
and containing 7 per cent water of erystallisation. It falls to powder in contact with
the air. By treating carbonate of calcium with camphoric acid, a salt is obtained
having an acid reaction, and crystallising in rhomboidal prisms, containing 87*6 per
cent water, and soluble in 6 pts. of cold water (Bucholz, Brandos). Neutral cam-
phorate of calcium yields, by dry distillation, carbonate of calcium and camphorone :

CwH".CaH)« - CO«Ca« + <>H"0.

Cmipkoraie of Co]rper, O^'H^Cu'O* (at 100^), is obtained by double decomposition
as a light green precipitate, nearly insoluble in water. It forms a dystalhsable com-
pound with ammonia.

Camphorate of Manganese is very soluble in water. Manganous salts are not pre-
cipitated by alkaline camphorates.

MercurouB Camphorate is a white precipitate, nearly insoluble in WHter.

Camphorate of Silver is a white fusible precipitate, which becomes coloured by ez-
posu^ to light

CJLBBVBORZO AMHWUMXDM* Anhydrotu camphoric acid, G'*H'^0'.0.
(Bouillon-Lagrange (1799), Ann. Chim. zxiii. 153. — Laurent, Ann. Ch. Fhys.
IxiiL 207.^ Halaguti, und. Ixiv. 151.) — Obtained by distilling camphoric or ethyl-
camphoric add, and crystallising the product from boiling alcohoL It forms fine prisms
without acid reaction, and haying no perceptible taste at first, but afterwards irri-
tating to the throat It dissolves very sparingly in cold water, a little more in boiling
water, veiy abundantly in alcohol, still more in ether. At 130^ C. it begins to sublime
in beautiful white needles, melts to a colourless liquid at 217^, begins to boil above
270^, and distils without residue. Specific gravity of the cnrstals 1*194 at 20^-5. They
become electric by friction, like resins. Their solution does not precipitate neutral
acetate of lead.

Camphoric anhydride boiled with water dissolves venr slowly as camphoric acid.
The transformation is effected much more quickly by alkaus. It does not absorb dry
ammonia gas, but aqueous or alcoholic ammonia converts it into camphoramate of
ammonium. Heated with phenylamine, it yields phenylcamphoramate of phenylam-
monium and phenvlcamphorimide. Heated with strong sulphuric add, it gives off
carbonic oxide, ana is converted into sulphocamphoric ac^ (q. v.)

C»«H"0« + H»SO« - 0*H»«SO« + CO

Cainphorio Sulpho-

anbydrtde. camphorio

acid.

i9n Camphorate of Ethyl, C"H«0* = C'»H"
(C*H*)*.0*. — This body is formed in the dry distillation of ethyl-camphoric add,
and is obtained by pouring water into the alcoholic mother-liquors from which the
latter has been preeipitat^. It is purified by boUing with afkalised water, drying
in vacuo, then washing, distilling, and again drying in vacuo. It is an oil having a
faint amber oolonr, a very disa^eeable bitter taste, and a powerful odour. Specific
gravity 1*029 at 16^ C. Begins to boil at 285° or 287° ; turns brown a few degrees
higher, and leaves a black residue, but the distillate is very pure after being washed*
It is perfectl V neutral and insoluble in water. Potash decomposes it like other ethers ;
Fulphuric acid dissolves it in the cold without decomposition ; at higher temperatures,
decompodtion takes place, but without blackening or evolution of sulphurous acid.
It is not altered by hydrochloric or nitric add, dther cold or hot (Malaguti, Ann.
Ch. Phys. Ixiv. 151.)

Dftrachlorinaied Camphorate of ethyl^ C^H'^Cl^O*, is produced by the action of
chlorine on camphorate of ethyl. Neutral ; has a bitter persistent taste. Soluble
in alcohol and ether. Spedfic ^vity 1*386 at 14° C. When heated it becomes very
fluid, and decomposes before boiling. Aqueous potash scarcely attacks it, but alcoholic
potash oonverta it into camphorate, acetate, and chloride of potassium :

C"H»C1*0* + 8KH0 = C'»H"K«0* + 2C»H»K0* + 4Ka + 4H«0.

(Malaguti, Ann. Ch. Phys. Ixz. 360.)

Camphorate of Ethyl and Hydrogen, Ethyl-camphorio or Camphovinic acid.
C'»H»0« » C»*H»*(C«H*.H)0*.— When a mixture of 2 pts. camphoric add, 4 pts. ab-
solute alcohol, and \ pt sulphuric add is boiled and cohobated several times, a residue
is obtained, which, when diluted with water, yields an oily deposit of ethyl-camphorio

732 CAMPHORIMIDE — CAMPHORTN.

acid. ThiB acid nas, at ordinary temperahires, the consistence of treacle. It b trans-
parent and colourless, has a peculiar odour and a very agreeable taste, not add, but
bitter. It dissolves very sparingly in alcohol and ether. Specific grarity 1-095 at
20*5° 0 ; reddens litmus pt^r alter a while only ; dissoWes in alkaline solutions^ bat
is decomposed when boiled with them. Water caBTects the same deoompositioa after
long contact or continued ebullition. By dry distillation it yields water, camphorie
anhydride, and camphorate of ethyl, together with rery small quantities of alcohol and
carburetted hydrogen gas, resulting trom secondary decomposition :

2C»*H»0* « HK) + C"H»H)» + C"H««0*
Eihyl-carrpborle Ounphorle Ounphoric

acid anhjdrlde. etner.

The alcoholic solution giyes a copious precipitate with neutral acetate of lead. (Ma^
laguti.) ^ ^

Ethyl-camphorie acid is monobasic, the formula of its salts being Cr*H"(Cli*jr;0*.
The ammonium, potassium, sodium, bariufn, strontium, aUcium, and moffTiesium-taltB
are soluble in wuter. The sine, copper, had, fiurcury, and «t/«0r-salt8 are icsolubia
or sparingly soluble. The ooppeiHsalt, obtained by predfatating sulphate of copper
with ethyl-camphorate of ammonia^ is probably a sesquibosic salt (Malaguti, Ann.
Ch. Phys. Ixiv. 161.)

Ca mp ho rate of Me thy I and Hy drogen, Hiethyl-camphorie or CampkomtthyUe
acid. C"H>H)« » C"H*\CH*.H)0«.— Obtained in the same manner as ethyl-cam-
phoric acid, substituting wood-spirit for alcohol The rendue of the third distillation
yields, when washed with water and left at rest, a crystalline mass, which is to be
pressed between pi^>er and boiled with water. It then forms an add liquid, at the
bottom of which some drops of oil collect, ehanging after a few days into well-
defined, colourless, shining crystals of methyl-camphoric add. These arstals are
either needles arransed in radiating groups, or small four-sided or six-sided laminie;
but on dissolving them in ether and leaving the solution to evaporate very slowly,
well formed prisms are obtain^ belonging to the trimetrie system, and exhibiting
the combination, P . ao P . oo F oo. Inclination of the faces, oo P : ao P » 106 30' ;
oot 00 : floP « 1260 45'; ooPoo : P = 116° 25' and 66o 4'; P : P - ISO® 30'. The

four-sided laminse are hemihedral, and exhibit only the combination - . 8J^eo , with

deavage perpendicular to ao ]^ oo.

Methylcamphoric acid is very little soluble in water, very soluble in alcohol, ether,
and chloroform. The solutions are strongly acid, and tarn the plane of polarisation of
a ray of light to the right: [a] - -i- 51° 4. The add mdts at about 68<^ C and re-
mains viscid a Ions time after cooling. By distillation it yidds camphoric anhydride,
a visdd liquid, and a slight rendue of carbon. Boiled with caustic potash, it gives off
wood-spirit and is converted into camphorate of potassium.

The aqueous and alcoholic solutions of the add form a white crystalline piredpitate
with acetate of lead, soluble in excess of the acetate ; with acetate of oojqwr, a greenish
crystalline predpitate ; with baryta-water, they form a cloud, which disappears on add-
ing a drop of nitric add. They have no action on lime-water or on soluble barium-
salts, but form a slight doud wiUi nitrate of silver. Oxide of silver is reduced by
them, producing a blackish deposits (Low, Ann. Ch. Phys. xxxviii. 483.)

CAMVBOBZaiZBB. C'«H»NO« = KBLCC^H'^O')". — Obtained by heating
neutral camphoramate of ammonium to 150° or 160° C, or by melting or <^igt.illi'ng cam-
phoramic acid :

C"H'»NO« = C'»H"NO« + HK)

Camphoramfc Cam|ihoiiinide.
acid.

and : C"H"(NH0NO» ^ C»H»»NO« + NH' + HK).

CamphoraniMte of Camphorimlde.
ammonium.

It is purified by solution in boiling alcohol and crystallises on cooling. It is ooloor-
less, volatilises at a high temperature without decomposition, and dissolves euly in
boiling alcohol, crystallising, on cooling, in tufts lUce fern leaves, beautifiilly divided ;
or by very slow cooling in hexagonal tables, oblique and mudi elongated. From a
solution in weak alcohol, it is gradually deposited in the form of a gummy, transparent
substance, which solidifies after some hours in opaque tuberdes. The alcoholic solu-
tion gives off ammonia when boiled with potash. It dissolves at a gentle heat in strong
sulphuric add, and, on pouring a few drops of water into the solutien, a white ays-
talline deposit is formed. (Laurent^ Compt. chim. 1845, p. 147.)

OAMVHOBZV. Camphorate of Glyceryl, — Produced by heating camphorie add

CAMPHORONE — CANADA BALSAM. 733

with glyceriiL Viscid ; Bolable in ether ; decomposed by oxide of lead, yielding gly-
cerin and camphorate of lead. (Ber thelot.)

OiLBiySOSOWB. Phorone(QteThar dt); Camphoryl (L&xiTent). C*H"0.—
This compound, the acetone of camphoric acid, was first obtained in an impure state,
as a product of the decomposition of that acid, by Laurent (Ann. Ch. Phys. [2] Ixr.
329), afterwards prepared pure and more thoroughly examined by Gerhardt and
Li&s-Bodart (Comptchim. 1849, p. 38&^.

Camphorone is produced, like other acetones, by the diy distillation of the calcium-
salt of the acid:

C"H"O.Ca«.0« « CO.Ca».0« + C»H»*0

Camphorate of Carbonate of Campho-
calcium. calcium. rone.

It is best to operate only on small quantities at a time. The brown or yellow oil
which passes over ia purified by fractional distillation, a small quantity of tar remain-
ing behind.

Camphorone is likewise obtained, together with other products, by distilling with
lime either of the followinffsubstances : 1. Acetic acetone, wnich differs from it only by
the elements of water (3C*H«0 - 2H»0 = C»H"0). On rectifying t^he distillate, oxide of
mesityl, CH'K), passes over at about ldl<^ C, and camphorone between 200^^ and 206^
(Fit tig, Ann. Ch. Pharm. ex. 33). — 2. Crrape-mgar, The distillate yields on recti-
fication, an oil boiling at 86^ C, having the composition of metacetone, C"H'*0' (and
converted into camphorone, or a body isomeric with it, by distillation with phosphoric
anhydride), while camphorone passes over at 208^ (Li&s-Bodart, Compt rend, xliii
394). — 8. The juice of ripe mountain-ash berries, which contains a smaU quantity of
malic acid : this method, nowever, does not always yield it (Li^s-Bodart, loc, cit.)

Camphorone is a colourless or yellowish oil, very mobile, lighter than water : and
having a strong odour Hke that of peppermint It boils at 208^ 0. (Oerhardt), and
volatiUses undecompoeed, yielding a vapour whose density » 4*982 (Gerhardt and
Li&s-Bodart), by calculation for 2 vol » 4*784. It is insoluble in water, but dis-
solves in alcohol and very readily in ether. It does not unite either with acids or
with alkalis, and accordinpf to Limpricht (Ann. Ch. Pharm. xdv. 246), dififers from
other acetones in not combining with add-sulphites of alkali-metals.

Camphorone becomes darker in colour when exposed to the air. It dissolves with
blood-ied colour, in strong sulphuric add, and is for the most part precipitated there-
from by water. It is resinised by nitric acid. Phosphoric anhydride acts quickly
upon it at a high temperature, converting it, by abstraction of water,into cumene, CH"
(not mesityleneX which passes over in fractional distillation at 170^ C, a carbonaceous
mass being left behind. Pentachloride of phosphorus converts it into a chlorinated
oil, CH'*5l, boiling at 176^ C, lighter than water, insoluble tiierein, easily soluble in
alcohoL The alcoholic solution, saturated with ammonia-gas, yielded a crvstalline
substance, probably C'H'^N.HC1 (Li^s-Bodart). Camphorone heated with potas^
sium, gives off hydrogen, and appears to form the compound C*H"KO (Liis-
Bodart). With potoM-lime it becomes heated, and appears to enter into combination ;
the mixture heated to 240° C. gives off a colourless oil, apparently different from
camphorone, while a resinous substance remains with the alkali (Gerhardt and
Li&s-Bodart)

CJLMVSOSIX. C*®H'M>*. The diatomic radicle of camphoric acid, &c The
same term was applied by Laurent to camphorone.

OAMFKOSVUPSintZO AOZB. See Sulphooamphobic Aan.

GAlKFHOVnfXC ACID. Camphorate of Ethyl and Hydrogen. (See Campuobic
Etkbbs, p. 732.)

CAMPHBJMfB. A product of the decompsition of camphor by sulphuric acid
(p. 728).

OAMFHSOVIL C**H^^O. — A liquid produced by passing camphor over red-hot
lime. It is a light oil, having a strong and peculiar odour, quite different from that
of camphor. It boils at 76° C, is insoluble in water, soluble in alcohol and in ether.
It is produced from camphor by abstraction of water (3C'»H'«0 - 2H»0 - C"«H"0),
and is perhaps identical with the product obtained by heating camphor with clay, or
by passing the vapour of camphor through a red-hot porcelain tube. (Fr^my, Ann.
Ch, Phys. [2] lix. 16.)

GAirvroOll. See Babwood (p. 517).

CAJTAAWITBi A greyish scapolite rock, from Canaan, Connecticut, containing
63*37 per cent. SiO», 4*10 Fe*0», 10-38 Al*d», 26*80 Ca*0, 162 MgK), and 400 C0».
(Dana, ii 203.)

See Balsams (p. 492).

734

C ANCERIN — CANNABIN.

O AVOBKXJr. An artificial goano ftom Newfoxindland.

OJkMCUA^lULayjJL, See Cacha-La.oua (p. 701).

OAMCWanVMm A maraiye mineral found near Miask in tlie TTral, in the Mariins-
kaja mine in the Tunskinsk monntains, Siberia^ and in Litchfield in the State of Maine.
It eleaveB parallel to the faces of a hexagonal prism, has an aneT«»n fractore, light rose-
red colour and waxy lustre, nacreous on the deayage faces ; transparent or strong^/
translucent. Specific gravity 2*46 to 2*46. Hardness 6*0 — 6'6. It melts to a vhite
tumefied glass. Hydrochloric acid dissolyes it readily, with effloiwBoenoe and separa-
tion of edatinous silica.

The following are analyses of eancrinite: 1. From Hiask; light red: a. Spedfie
gravity 2*463 (Q-. Rose, rogg. Ann. zlrii. 376) ; b. Specific giavity 2*489 (Pusi-
rewsky, Kokscharow's MaUrialen zur Mtnercdogie Kusslands, i. 81). — 2. From the
Tunskinsk Mountains, yellow; a. Specific gnmty 2*449 (Strnre, Pogg. Ann. zc
613); b. Specific gravity 2*448 (Pusirewsky).— 3. From Litefafldd. a. YeUow.
Spedfie gravity 2*448; b. Greenish. Spedfie gmvity 2*461. (Whitney, ^tid, '
431.)

From Hiuk. From the Toniklnsk Mu. From Maine.

G. Rom. Puairewtky. ScruTe. Potircwtky. Whltncj. VfhHaefm

Silica . . . .
Carbonic anhydride
Aiumiiia . . . .
Ferric and Manganic I
oxidei 3

Lime . • • .
Soda . . • .

Poia<h

Water . . . .

6*38

40-43

88-iS7

6-70

17-52

0-70

b-hH
85-96
29-57

0*19

5'6A
18-53

369
S03 0*3*i

10000

99*49

S'b\*
3S-S3
28-66

424

90-37

100*00

6*61
3772
27*27

3*11

21-60

4-07
99*86

6-95

37 72
S7-M

0*75

S<87

20Tr7
0*67
2-89

99*60

6-91
37*20
27-69

0«

20^46
0-90

100*46

From these results, Rammelsberg concludes that the mineral is a mixture of
bonate of calcium with elsBolite, containing a smaller proportion of potash and more
water than the usual amount (Rammelsberg's Mineraichemief p. 653; Dana, iL
232.)

See Spinel.

Cosiua duicis, Whitt Cinnamon. — ^These names am ap*
plied to the baas or inner bark of Candla alba^ a canellaceous tree growing in the West
Indies, especially in Jamaica. It forms reddish-yellow tubes, three feet long and an
inch thick, having a pleasant aromatic taste and odour: it contains about 8 per cent,
of manna (formerly mistaken for a peculiar kind of sugar called eaneilin\ besides
starch and the other usual constituents of vegetable structures. By distillation with
water, it yields two volatile oils, one lighter than water, the other heavier. If these
oils be left in contact with potash-ley, the liquid then diluted with water and distilled,
the first portion of the distillate is again lighter than water, and at last a heavy oil is
obtained, of very peculiar odour. The potash-ley from which the oils have been dis>
tilled, yields by neutralisation with acid and distillation, a heavy oil, smelling like oil
uf cloves. The light oil of whit« cinnamon smells veiy much like oil of ciyeput, It
may be separated by fractional distillation into several oils, dififering greatly in boiling
point White cinnamon contains about 6 per cent, of ash, consisting nuunly of car^
bonate of calcium. (Handw. d. Chem. ii. [2] 927.)

Syn. of Bbucimb.
A poisonous resin extracted from hemp, by exhausting the bruised
plant {Gunjah) with alcohol, after the greater part of the brown roloiuing matter has
been removed by digestion, first in tepid water, afterwards in solution of carbonate of
sodium, then precipitating the chlorophyll with lime, decolorising witb animal ehaicoal,
and evaporating. (T. and H. Smith, Pharm. J. Trans, vi. 127, 171.)

From the Extract, hh. eanab. ind. tpirituoB. G. Martins has prepared a reaan, by
treating it with cold alcohol of 83 per cent., mixing the dark green filtrate with wat«r
tiU turbidity ensues, agitating with animal charcoal, filtering and distilling off the
alcohol : the resin then separates. It is a light brown, shining substance, becomix^
glutinous and ductile, has a peculiar narcotic odour, like that of the extract, and an in>
tensely bitter taste. It melts at 68^ 0., bums with a bright smoky flame, is insoluble
in potash and ammonia, but dissolves in alcohol and ether, spuingly alao in acids.
Volatile oils dissolve it in the cold; fixed oils, with aid of heat.

The narcotic effects of haschish {q, v.) are due to hemp-resin. (Handw. d. Chem. ii.
[2] 727.)

* Carbonic anliydride and water.

CANNABIS INDICA— CANTHARIDIN. 735

CAMMAMSM ZV]WCJL« Indian Hemp. — This plant; which is indigenous in
India and Asia Minor, is much used in the £ast as an intoxicating agent ; the narcotic
action appears to reside essentiallj in a resinous exudation (see Caknabin and
Haschish). According to Martius (Chem. Centr. 1856, 225), the herb contains a
small quantity of essential oiL The herb dried at 100^ C. yielded 18' 1 per cent, ash,
which, after deduction of carbonic anhydride and sand, contained in lOOpts. : 13*6

Sotash, 1*4 soda, 32*0 lime, 10*4 magnesia, 8*8 phosphate of iron, 10*1 phosphoric an-
ydride, 0*3 sulphuric anhydride, 1*2 chlorine, and 22*1 silica.

OAMMAMXB aJLTTlTA. Common hemp.— -The leayes of this plant contain 40*6
per cent-, carbon, 6*9 hydrogen, 1*8 nitrogen, and 22*0 ash ; the stems : 39*9 per cent. C,
5*0 H, 1*7 K, and 4*5 ash. (Kane, J. pr. Chem. zxxii 354.)

Reich (Jahresber. d. Chem. 1850, Tafel C. p. 661), found in the hemp-^lant 4*6
per cent ash ; in the seed 6*3 per cent The analyses of the ash of the entire plant
and of the seed, are given in the following table :

K«0 Na*0 Ca'O Mg«0 A1*0» Fe*0» S0« SiO« I»0» CI C0«

Plant (Kane) 7*5 0*7 420 4*9 0*4 — 1*0 6*7 3*2 1*5 31*9

„ (Reich) 15*8 8*4 35*6 7*7 — 1*1 2*7 7*7 14*2 3*4 8*4

Seed (Reich) 18*5 0*8 20*2 10*2 ~ 1*2 0*2 9*6 37*6 01 1*3

According to Leuchtweiss (Ann. Ch. Pharm. 1. 416), hempseed yields 5*6 per cent,
ash, containing 20*8 K«0, 06 Na«9, 25*6 CaH), 10 Mg*0, 33*5 PH)*, 13*5 SiO«, 6*2
sand and charcoal, and small quantities of sulphuric acid, chloride of sodium, and ferric
oxida

Hempseed yields 31*8 percent oil, 22*6 albumin, and 6*37 ash, of which 2*47 con-
sists of phos^ates (Anderson, Highland Agr. Soc Journal [new series] No. 50).
The oil is C"H^O','and yields with chlorine and bromine, the substitution-products
C"H»a*0«, and C"H»Br'0«. (Lefort, Compt rend. xxxv. 134.)

The leaves, flowers, and pollen of hemp have been examined by Schl«singer,
(Rep. Pharm. Ixxi 190). The ash of the leaves contains 8*0 per cent soluble, and
9*2 per cent insoluble salts. (Kane.)

OAMWrnSk OOA&^ Bee Coal. ,

CAnoV BCXTAJb. See C!offbb, Allots of.

OASTBAJUmBS. Banish Flies (Lyita vesietttoria.) — These coleopterous in-
sects, so well known for their vesicating properties, are much used in medicine in the
form of tincture, plasters, &c. Their vesicating power is due to a peculiar acrid
principle called cantharidin. Taken internally, they act as a powerful aphrodisiac,
and may even destroy life. According to Thoury (J. Pharm. Jan. 1858, p. 65), their
poisonous effects may be counteracted bj the administration of animal charcoal

When the aqueous extract of canthandes is treated with alcohol, cantharidin is dis-
solved, together with other substances, and a brown nitrogenous substance remains.
On evaporating the alcoholic extract and treating the residue with ether, the canthar
ridin dissolves, together with a yellow substance, and an extractive matter remains,
which reddens litmus and contains lactic add, together with a nitrogenous substance.
The aqueous decoction of canthandes reddens litmus strongly, and gives with ammonia
a precipitate of ammonio-magnesian phosphate (Rob iquet, Ann. Chllxxvi. 302). When
the insects, after being exhausted with boiling water, are treated with boiling alcohol,
a greenish fatty oil dissolves, destitute of vesicating power, and consisting, according to
Gossmann (Ann. Ch. Pharm. Ixxxvi. 317), of olein, stearin, and palmitin.

OAVTBASZBZV. C*H''0'. Isomeric with picrotoxin. (Robiquet ^* ^'^.;
Regnault, Ann. Ch. Phys. [2] Ixviil 151; Thierry, J. Pharm. xxi. 44; Warner,
Amer. J. Pharm. xxriii. 193 ; Procter, Pharm. J. TrsuDB. xxi. 44.) — This substance,
which is the active principle of the Spanish fly, is likewise found in the following
coleopterous insects : — Lytta vittata^ L. nnficoUis, L, ffigas;MyUxbris etchorH (Chinese
canthandes), Af.pustulata, Af. punotum^ M. Stdm^ M, Schomherri/Meloe violaceutf
M. autumnaliSf m, Furca, M, punctatus^ AT. varieg<Uu8j M. seabrosus^ M. majaiis.
According to Warner, Li/tta vesicatoriai L. vittata, and Mylabris cicharii contain about
0*4 per cent of cantharidin. According to Ferrer, Mylabria punctatus contains 0*33
per cent, M. puncium 0-19, M. dchorU 0*10, M. Sida 0*12, if, Sckoenherrii 0*15 per
cent

Cantharidin is prepared from Spanish flies, or better ih>m Myldbris eichorn, inas-
much as this insect contains less fkt, by digesting the pulverised insects for some
days with ether, ether-alcohol, or alcohol alone ; completing the extraction in a dis-
placement apparatus, the ether or alcohol being ultimately displaced by water; and
distilling on the ether or alcohoL The cantharidin, which ciystallises out on cooling,
is redisaolved and purified with animal charcoal Ether is preferable to alcohol for

736 C ANTONITE — C AOUTCHIN.

the preparation, since it dissolyes less of a green oil, which adheres obstinately to the
canthandin (Thierry). According to Procter, cantharidin is best extracted by chloro-
form. The pnlyeiised cantharides are left in contact for some time with twice their
weight of chloroform in a displacement apparatus ; the chloroform is then dndned ofi|
and finally displaced by alcohol, and the solution is left to evaporate, whereopon the
cantharidin cxystallises out, saturated with the green oil. It lb laid on bibnloiu paper,
which absorbs the greater part of the oil, then ciTstallised from chlorofoim mixed
with alcohoL

Pure cantharidin forms colourless nght-aneled four-sided prisms of the dimetrie
system, acuminated with four facea resting on me lateral faces. According to^octer,
it crystallises from ether in oblique four-sided prisms, with dihedral summiti, hating
the aspect of micaceous laminae. It melts at 200° C, and TolatiliseB in white fames,
which strongly irritate the eyes, nose, and throaty and condense in rectangular primu,
haying a strong lustre, and sometimes iridescent.

Cantharidin perse is insoluble in water, but it is rendered soluble by the presence of
other substances (see the last article). It Tolatilises in small quantity at 104^0., and
more quickly at 182^^ ; not with Tapour of water. It dissolyes readily in aleokol, in 34
pta. of cold etheTf and rather less of hot ether ; acetic ether, wood-spirit, and aetUme
also dissolve it readily when hot, and deposit it on cooling. But its best aolTent is
chloroform, which extracts it even from the aqueous infusion of cantharides. It like-
wise dissolves in oils, both fixed and volatile. Its solution in any of the liquids abore-
mentioned possesses the vesicating power, which, however, is not exhibited by
cantharidin in the solid state. A grain of cantharidin mixed with an ounce of laid
produces venr strong vesication. Cantharidin dissolves in sulphuric acid, and is re-
precipitated by water ; also in hot hydrochloric and nitric acids, whence it ciystaQiicfl
on cooling ; phosphoric, acetic, and formic >acids diseolvehut little of it at ordizuuy tem-
peratures, it dissolves in potash-icy, and is precipitated by acetic acid. Ammonia
has no action upon it.

O AXTO VXTB. A variety of sulphide of copper, Cu^S, from the Canton mine in
Georgia, having hexahedral deavage, bluish-black colour, and semi-metallic lustre.
I^>ecific gravity » 4*18. Hardness « 2*0 (N. A. Pratt, ^JL Am. J. [2] xxiii. 409).
Genth {wid. 417) regards it as a pseudomorph of covellin afte^galena.

CAVTOV*8 VBOSPBOXUB* A phosphorescent substance prepared by cal-
cining for an hour, at a red heat in a crucible, a mixture of 3 pts. of finely grouid
oyster-sheUs with 1 pt of flowers of sulphur. A better phosphorescence is obtained
by calcining the entire shell in a closed crucible, after dusting it over with sulphur.
Exposure to bright light is necessary to its luminosity in the dark. The magnesia
in the shells is said to be essential to the effect. Gypsum mixed with flour becomes
phosphorescent when calcined.

OAOVTCRWB. A hydrocarbon, isomeric with t«trylene, C*H', said by Bon-
chardat (J. Pharm. Sept. 1837, p. 464), to be produced, together with others, by the
diy distillation of caoutehouc {q. v,) It has a density of 0*66, boils at 14*5^ C, and
solidifies in brilliant needles at — 10^.

CAOUTOBnr. C"H». (Himly, Ann. Ch. Pharm. xxvii. 41 ; Gr. Williams,
Proceedings of the Boval Society, x. 517 ; Gm. xiv. 326.) — ^A hydrocarbon contained,
together with many other substances, in the oils produced by distillation of caontchooe
and gutta percha. To separate it, rectified oil of caoutchouc boiling between 140° and
280^ C, is repeatedly shaken up with dilute sulphuric add, then washed alternately
with water and potash-ley, and distilled with water several times. The distillate is
dehydrated with chloride of calcium and rectified per se, the portion which distils be-
tween 160^ and 175^, being collected apart; from this, by repeated rectification and
removal of the portions which pass over below 166^ and above 174^, caoutchin is at
length obtained, boiling between 168^ and 171^; and this product, by repeated fis^
tional distillation, may be brought to boil at 171^. The purification mav also he
effected by passing dry hydrochloric acid gas into the cooled oil, previously (uied orer
cliloride of calcium, whereby hydrochlorate of caoutchin is produced ; decanting this
liquid from the resin, after it has stood for some days ; dissolving it in absolute al-
cohol ; precipitating with water ; dehydrating it, and decomposing it by distillation
over caustic lime or baryta^ and finally over potassium. The product thus obtained
is pure caoutchin. (Himly.)

Caoutehin is a transparent, colourless, mobile liquid, having an odour like that of
oil of orange, but not quite so agreeable, and a peculiar aromatic taste. It makes
transient grease spots on paper. Specific gravity 0*8423 at 0° C. Boils at llb'b^ st
0*76 met, pressure. Poes not solidify at —39°. Vapour-density 4*461 (Himly), 4"65
(Williams), by calculation (2 vols.) » 4*714. It has but little electric conducting
power.

CAOUTCHIN. 737

Caoatchin duaobreB in 2000 pts. of toater. It likewise takes up a small quantity of
vmter in the oold, and at higher temperatures a larger quantity, which separates on
cooling. It dissolves in all proportions of alcohol, ether, and acetate of ethyl ; water
separates it from the alcohoUc, but not £x>m the ethereal solution, unless alcohol be
afterwards added. The alcoholic solution bums with a bright flame, which does not
smoke if the caoutchin and alcohol have been mixed in the right proportion. It dis-
solves slightly in concentrated aeetio and fomm acids ; also in oils both fixed and
Tolatile.

Caoutchin absorbs oxygm from the air (45 toIs. in fourteen days), and is oonyerted
into a resin, part of it, however, volatilising. It is likewise resinised by various oxidis-
ing agents, e. g, by peroxide of hydrogen, nitric oxide, nitrous acid, strong nitric acid,
and crystallised chromic a/dd; it reduces eupric oxide to cuprous oxide 9JiA permanganate
of potassium to peroxide of maoganese, but exerts no deoxidising action, even at the
boiling heat, on the oxides of lea{ mercuric oxide, or chromate of potassium. It is like-
wise unaffected by sodium, potadb, baryta, or lime. With potassium it evolves a few
ggs-bubbles, and covers the metal with a ^pey film, then remains unaltered.

Of hydroaen, caoutchin absorbs 2 vols, in three weeks at 20° C. ; of carbonic anhy-
dride 11 vols. ; carbonic oxide, marsh-gas, and olefiant-gas are not absorbed by it. Of
nitrogen, it absorbs 6 vols, in five weelu ; of nitrous oxi& a small quantity ; nitric oxide
colours it yellow after a while. It absorbs 8 vols, a/mmonia-aas, but does not mix with
aqueous ammonia. It does not absorb cyanopen gas, but hyarocyanic acid and chloride-
of cyanogen are absorbed by it in any quantity. It dissolves phosphorus and sulphur
sparingly in the cold, rather more freely when heated; does not absorb sulphydric acid
gas, but mixes in all proportions with sulphide of carbon and xanthic acid. It ab-
Borbs hydrochloric, hydrobromiCf and hydriodic acid gases, forming the compounds
C'*H*'.HC1, &C. It easily dissolves the chlorides of sulphur, phosphorus, and carbon,
small quantities of iodide of sulphur, and ioaide of phosphorus. It dissolves a larga
quantity of bemoic, and a small quantity of oxdUo acid; but not malic, citric, tartrate,
tannic, mucic, or succinic acid.

Caoutchin dropped into strong sulphuric acid, becomes heated, eliminates sulphurous
anhydride, and forms a brown unctuous acid, 0'*H'*SO*, which forms soluble barium
and calcium-salts, the latter having, according to Williams, the formula CH'*CaSO'.
Boiled with strong selenio acid, it turns brown and gradually decomposes. It is not
decomposed by phosphoric or phosphorous acid,

Wita chlorine, caoutchin gives off hydrochloric add and forms' chlorocaoutchin,
which, after washing with soda-ley, then with water, and dehydration over chloride of
calcium, forms a transparent, colourless, neutral, viscid liquid, of specific gravity 1*433,
having a strong eth^eal odour and extremely sharp burning taste. It (ussolves
sparingly in water, easily in alcohol and ether, gives off irritating vapours of hydro-
chloric add when distilled per se, and yields a variety of oily products by distillation
with alkalis.

With bromine, caoutchin gives off hydrobromic add, but remains colourless and
transparent ; it easily separates bromine from its solution in water, alcohol, or ether,
forming heavy drops of oil. Caoutchin mixed with | vol. water decolorises bromine
till 231*7 pts. bromine have been added to 100 pts. caoutchin, which is in the ratio
of 4 at. bromine to 1 at. caoutchin.

By the alternate action of bromine and sodium on caoutchin, 2 at. hydrogen are re-
moved, andcymene, C^*B}*, is produced. (Williams.)

With iodine, caoutchin turns black, and gives off hydriodic add. It abstracts
iodine from solution in water, alcohol, or ether, forming iodocaoutchin, which is a
black-brown oil, giving off hydriodic add when distillec^ easUy decomposed by heating
with oil of vitriol, bromine, chlorine, filming nitric acid, or potash, nearlv insoluble in
water, but soluble in alcohol or ether. Caoutchin distilled with excess of iodine, forms
a colourless firagrant oil.

Hydrochlorate of Caoutchin, C^WJRCL — This compound is prepared bypassing dry
chlorine gas into caoutchin cooled with ice, the delivery-tube terminating a little
above the surface of the liquid, — washing the product first with soda-ley, tiien with
water, and drying over chloride of caldum. It is also produced, though in an impure
state, by treating caoutchin with trichloride of antimony or mercuric chloride. It is a
transparent, colourless, neutral, viscid liquid, having a strong ethereal odour and a very
sharp burning taste. Specific gravity 1'433. It gives off verjr irritating vapours of
hydrochloric add when distilled ; is decomposed by boiling with sulphuric acid, with
elimination of hydrochloric add ; and yields a variety of oily products by distillation
with potash, lime, or baryta. It dissolves sparingly in water, easily in alcohol and
ether ; also in hot nitric add and sulphuric add, separating out unchanged on cooling;
but by long boiling with the latter, it becomes carbonised and gives off hydrochlono
add.

Vol. I. 3 B

. I

738 CAOUTCHOUC.

OAOUTCBOVO. Gum dastie, or India Bubber. Gomme iUuHque. Federkars. —
A product of several genera of arboraceoua plantB, in which it occurs in the form
of a milky sap, and exudes from incisions made in their trunks. Among these trees
are the 9ip&nia elasHcCf 8. Cahuchu, Hevea caoutchouc, H, Guianenns, Jatropka
daatica, Ficus elastica, F. indica, F, rdiaiosa. Formerly tiie greater part of the good
caoutchouc was imported from Para in South America, but an excellent article has of
Lite years been brought from Assam and other districts of India, in which the trMs
that yield it greatly aboimd. The juice drawn from the old ti^es and in the cold
season is preferable to that from the young trees and in the hot season, the quantity
being greater the higher the incision is made across and through the bark of the tree.
The fluid is of a creamy consistence and colour. Its specific grayity, as imported into
this country in well-cfosed yessels, used to rary from 1*0176 to 1*04125 (Ure); the
lighter juice yielded 37 per cent of solid caoutchouc ; the denser only 20, though it
was the thicker of the two. Some samples of juice have a brownish tinge, which pro-
ceeds from a little aloetic matter secreted along with it» which, if dried up in it,
gives the caoutchouc a certain degree of viscidity, and by its decomposition eventually
destroys its firm texture. Such juice ought to be mixed with its own bulk of water
and boHed, whereby the aloes are separated and the caoutchouc concretes into a
white elastic mass, free from offensive smelL

Much of the caoutchouc is imported in coarse rough masses. These are deaned by
washing in a trough, with a stream of water, and afterwards kneaded together by tho
strong pressure of iron-arms in an iron box. The masses thus obtained are next
moulded into the forms of square or round cheeses in a press, and finaUy sliced by
knives driven by machinery into thin cakes or ribbands. U.

Faraday recommends for the purification of caoutchouc, to dilute the natural juice
with four times its weight of water, and^eave it at rest for twenty-four hours. The
caoutchouc then separates and rises to the surfiue in the form of a cream. This is re-
moved, difflised through a fresh quantity of water, and again left to settle at the surface.
By repeating this operation till tne wasn-water is perfectly limpid, the caoutchouc may
be obtained veiy nearly pure. It is then to be spread upon a pute of unglazed earthen-
ware to absorb the water, and afterwards pre89ed.

Pure caoutchouc is colourless and transparent, but the best found in commerce has
a more or less dingy colour from having been dried from the juice in a smoky atmo-
sphere. It is a bad conductor of heat, and a non-conductor of electricity. It is veiy
combustible, and bums without residue, emitting a white light. At ordinary tempe-
ratures, it is soft, flexible, and highly elastic fVeshly cut surfaces adhere easily and
firmly when pressed together, a property which is made available in forming tubes and
vessels out of sheet-caoutchouc. Below 0° G. it becomes hard and rigid. Wnen heated,
itgradually softens, and at 120*^ C. (248^ F.) begins to melt; when it is fused, it re-
mains greasy and semi-fluid after cooling, but if exposed to the air in thin layers,
graduaUy dries up and recovers its original properties, provided it has not been heated
much above its melting point If, however, it be heated to 200^ G. (398^ F.) it begins
to fume, and is converted into a viscid mass which no longer dries up. If mixed in
this state with half its weight of lime slaked to powder, it forms a tenacious non-drying
cement, which serves admirably for attaching glass-plates to vessels with ground lips,
such as are used for preserving anatomical preparations, as it forms an air-tight but
easily-loosened joint ; if a drying cement be required, a quantity of red lead may be
added equal in weight to the lime.

According to the experiments of Ure (Phil. Trans. 1822), confirmed by those of
Faraday (Quart Journal of Sc. Lit. and Art, xi 19), caoutchouc is composed wholly
of carbon and hydrogen, containing 87*5 per cent, of carbon, and 12*5 hydrogen. It is
not, however, a simple proximate principle, but chiefly a mixture of two substances,
one much more soluble in ether, benzene, and other liquids than the other.

On examining with the microscope a thin sheet of caoutchouc, it is seen to be filled
with irregularly rounded pores, partly communicating with each other, and dilating
under the influence of liquids. It is perfectly insoluble in water and alcohol ; but
ether, benzene, rock-oil, and sulphide of carbon, penetrate it rapidly, causing it to
swell up and apparently dissolving it

The liquid tnus formed, is not however, a complete solution, but a mixture formed
by the interposition of the dissolved portion between the pores of the insoluble sub-
stance, whica is considerably swelled up, and has thus become easy to disintegrate.
By employing a sufBcient quantity of these solvents, renewed frt>m time to time, with-
out agitation, so as not to break the tumefied portion, the caoutchouc may be com-
pletely separated into two parts, viz. a substance perfectly soluble, ductile, and adhering
strongly to the surface of bodies to which it Is applied ; and another substance, elastic,
tenacious, and sparingly soluble. The proportions of these two principles vary with
the quantity of the caoutchouc and the nature of the solvent employca. Anhydrous

CAOUTCHOUC. 739

ether extncta from amlser^Kioloured caoutchouc 66 per cent of white soluble matter;
oil of turpentine separates from common caoutchouc 49 per cent, of soluble matter
baying a yellow colour.

The be«t solvent for caoutchouc is a mixture of 6 to 8 pta of absolute alcohol and
100 pts. of suli>hide of carbon. (Pa yen. )

CSaontehottC is not altered bj dilute adds. Strong solphurio acid acts slowly, and
fummg nitric add rapidly on it» the latter with complete decomposition. It resists
strong alkaline-leys, eyen at the boiling heat

C^utchouc yields by (fyyc^M^a^tofi, an empyreumatio oil caUedoil of caoutchouc
or eao utchoucin, which forms an exoiallent solvent for caoutchouc and other resins. It
is a mixture of a considerable number of hydrocarbons. Ordinary impure caoutchouc
likewise yields small quantities of carbonic anhydride^ carbomo oxide, water, and
ammonia.

Bespecting the nature of the hydrocarbons contained in caoutchouc-oil, different ex*
peiimenters have amyed at somewhat difierent results. According toBouchardat
(J. Pharm. xxiiL 467 )f the most volatile of the hydrocarbons has a density of 0*63 at
— 4° G. ; boils at a temperature above 0^ C, is not solidified by cold, and is perhaps
identical with tet^ylene, C^H'. The next, caoutchene, isomeric with the first, has
a density of 0*65, boils at 14*6^ C, and solidifies at —16^ in briUiant needles which
melt at -10°.

The less volatile portion of the oil, which does not distil tiU the temperature is
raised to 816° 0. and does not solidify at the lowest tempeiatures, is cidled heveene.
It is a dear ydlow oil of specific gravity 0*021 at 19°U. and belonging to the gim-
phene group, OH^. It mixes with aloohol and ether, absorbs chlorine quickly, and
solidifies to a waxy mass. By repeated treatment with strong sulphuric add and
potash-ley, it is converted into an oiJ, boiling at 228^0., having a sweeter and more
agreeable taste than heveene, and similar in many respects to eupione. (Bouehardat)

Himly (PhiL Mag. [8] IvL 679), by subjecting caoutchouc-oil to repeated fractional
distillation, obtained : 1. An oil caUea Faradjuyin^ boiling at 33° C, of specific gravity
0*664, and dissolved by strong sulphuric add without evolution of sulphurous anhydride.
Accoxding to liebig, water separates from this solution a colouness oil boiling at
220^0. According to Gregory, both this and the more volatile oils belong to the
group of camphenes, OH'*. The oil unites with chlorine and bromine, forming
brown liquids. — 2. A mixture of oils distilling at 96° C. from which potash extracts
creosote, and dilute sulphuric add separatee a brown resin, destroying tne odour at the
same time. According to Himly, the percentage of carbon in these oils increases as
the boiling point rises. — 3. Gaoutchin (p. 736).

Another hydrocarbon, isoprene, polymeric with eaoutchin, and boiling at 87 —
38° G., has been obtained by Gr. Wil hams (Proc Boy. Soc. x. 66), from the SistiUation
of caoutdiouc. From the composition of these sevoral hydrocarbons, it appears that
the decomposition of caoutchouc b^ heat is merely the disruption of a hydrocarbon into
other compounds polymeric with it

The residue left in the retort a^^ the volatile oil of caoutchouc has distilled off,
forms, when dimolved in the oil, a varnish much used by shipwrights, being impervious
to moistore and very elastic An exceedingly tenadous glue is i&> made by dissolving
1 pt of caoutchouc, cut up into small pieces, in 4 pts. of coal-tar, adding 2 pts. oi
shellac when the solution is complete^ and heating the whole in an iron vessel.

YuusANiSBD GAOuTCHOua — When caoutchouc is kneaded in an iron box with
flowers of sulphur heated to about 112° G. (234° F.), it takes up a certain portion of
sulphur, and acquires new properties which greatly increase its utility for various

Surposes in the arts. It remains perfectly flexible at temperatures below 0° G. and
ocs not soften at 60^ G. (122 F.), whereas ordinary caoutchouc becomes perfectly rigid
at temperatures several degrees above the freesing point while a moderate heat ren-
ders it so soft and adhenve as to be useless. This sulphured or vulcanised caoutdiouc,
is an excellent material for tubes for conveying water or gases, or for bags to hold gases
under pressure.

The vulcanisation of caoutchouc requires a temperature of about 160°G. (304°F.),
maintained for a few minutes only. A longer contact with sulphur at that temperature
causes the caoutchouc to absorb too much, which renders it hard and brittle. Yidca-
nised caoutchouc appears to retain only one or two-hundredths of its weight of sulphur
in the state of combination ; a larger quantity, 16 or 20 per cent, remains simply
interposed between the pores, and may be extracted dther by the action of solvents,
•och as ether, benzene, and sulphide of carbon, or by friction, or alternate extension
and contraction. If the vulcanised caoutchouc be heated to 120° G., this mechanically
interposed sulphur enters into combination with the caoutchouc and rendejn it brittle.
The same combination takes place slowly at ordinary temperatures, so that the caout^
ohouo after some time^ loses its elastidty and becomes britue. By contact with certain

8b 2

740 CAOUTCHOUC — CAPILLARITY.

metalB, such as lead or sUrer, the free sulphur in the pores of the caoutchouc u ab-
stracted, and thus again the quality is deteriorated.

The vulcanisation of caoutchouc is effected in various ways : 1. By immenbg the
sheet-caoutchouc in flowers of sulphur heated to 112° G. till it has absoihed about ^
of its weight, and then heating it for a short time to 160^ C^ or by immoung the
caoutchouc in flowers of sulphur heated to 160°, and keeping up that tempentoM till
the sulphuration is complete. — 2. By immersing the caoutchouc in a mixture of 100 pti.
Bulphiae of carbon, and 2*6 protochloride of sulphur, and then pLungiDg it mto
water to decompose the excess of chloride of sulphur. — 3. By immersing vtidei of
caoutchouc alr^idy manufactured, in a solution of polysulphide of caldum msiking
25^ Baum^, keeping them in it for three hours in a closed vessel at 140^0., and thea
washing them with weak alkaline-ley of 60° Bm. This process always yieUa the
right amount of sulphuration. — 4. By powdering 100 pts. of the caoutchouc in rough
laminae, with a mixture of 4 pts. flowers of sulphur and 60 pts. slaked lime, preeniig it
between rollers so as to incorporate it thoroughly with the powder, then makiog it
into various fabrics by the usual processes, and eroosing the finished artidee for an
hour to the action of vapour of water. By this last treatment^ the snzfiioe of th«
caoutchouc experiences a xind of washing, which removes the excess of sulphide of
calcium, and brings it to the exact degree of sulphuration required.

Hardened CaotUchaue. Ebonite, — Caoutchouc may be hardened and rendered soa-
ceptible of polish by mixing it in the kneadinff machine or between rollers, with
half its weight of sulphur, rolling the mass into lueets, and heating it for two hoora
to 100° C, and then for four hours to 160°. At the latter temperature, the maas may
be rolled ; when cold it may be cut like ivory. It serves for the mannfibcture of
combs, kxdfe-handles, buttons, &e. It is also preeminently distinguished by the laise
quantity of electricity which it evolves when rubbed, and is therefore admirably
adapted for the plates of electrical machines. It resists the action of aolvents eren
more obstinately than elastic vulcanised caoutchouc, scarcely even swelling up liien
immersed in sulphide of carbon. (For a full account of the manufacture and uae of
caoutchouc, both ordinary and vulcanised, see Ur^s Dictionary o/ArtSf Manufaeturu
and Mines, i. 681—604. Muspratfs Chemistry, p. 441 — 461. Pay en, ?rkii it
Chimie IndustrieUe, 4»* ^d. i. 139—184. Handto. d, Chem. 2'* Aufl. ii. [2] 836-^3.)

CAOUTCBOirCf amfH>/ITi. See Ejjltbbitb.

OAOVTOBOVCZV. Empyreumatic oil of caoutchouc (p. 739).

OJk9WMBm See Cappajus.

CAVBOPXCKITB. SyiL of Khsin or Bhababbabiw.

C APX&&AXZTT. The surfiuse of a liquid at rest is horisontal, excepting where
it comes in contact with the sides of the vessel ; there it is curved, being eoncaye if the
liquid wets the vessel, convex in the contrary case. Moreover, if on,e end of a namnr
tube be dropped into the liquid, the level of the liquid withia the tube ia not the same
as that without, but higher if the liquid wets the vessel and assumes a concare auface,
lower if it does not wet the vessel and forms a convex surface ; thus water, alcohol,
ether, oils, &c., rise in narrow tubes of glass, metal, or wood, having the inner anifaoa
clean ; but if the surface is greased so that the liquid cannot wet it, depreaaion takes
place instead of elevation : mercury is also depressed in tubes of glass, but rises in a
tin tube, to which it can adhere. The phenomenon is called capillarity (fitnn
capilla, a hair), because it is most conspicuous in tubes of very fine bore. The teim ii,
however, extended to all the alterations of level and form of surface ^^lieh take place
at the contact of liquids and soUds. The curved saiSsoo of the liquid within the
tube is called a meniscus.

The amount of elevation of a liquid in capillary tubes is measured by mdsog off
with the cathetometar (a telescope moving up and down a vertical scale, ^ 274), iintthe
height of the lowest point of the meniscus, then the height of a fine metadhc point brought
exactlv in contact with the surface of the liquid. In mft^iwg this last obsenration, the
point IS brought down to the surface of the liquid, till it exactly coincides with its re-
flected image therein, and a small quantity of the liquid is then removed with a pipette
so as to leave the extremity free. Another mode of observation, adopted chiefly fot
measuring the depression of mercury in glass tubes, is to place the liquid in a syphoo-
tube one arm of which is of capillary ^re, while the other is wide enough to reader
the alteration of level due to capillarity imperceptible^ The difference of level in the
two arms is then read off with the cathetometer.

By these methods it has been found that the elevation or depressioii of liqnidi in
capillary tubes is regulated by the following laws :

1. In a tube of given diameter, the amount of elevation or depression depends npon the
nature of the liquid, and not at all upon the nature or the thidmess of the material of
the tube, the nature of the tube merely determining whether theUquid shall beelfitated

CAPNOMOR— CAPPERIS SPINOSA.

741

or depressed, according as the tube is or is not wetted by it, but not affecting the
amount.

2. The amount of elevation or depression varies with the temperature, but not accord-
ing to the same law as the density. Thus 6ay-Lussac found that in a tube of 1 milli-
metre diameter, the heights to which alcohol rose yaried with the temperature and

density, as follows :

Dentltj. Temperature. Height of Colamn.

0-8196 S^C. 1218 mm.

0-8185 16 „ 915

0-8595 10 „ 12-01

0-9415 8 .. 12-91

9*
ff

3. In very narrow cylindrical tubes, the amount of elevation or depression of a given
liquid varies inversely as the diameter of Uie tube.

4. In the annular space enclosed between a wide cylindrical tube, and a solid cylinder
which nearly fUls it, the height to which a liquid tibgb is half that to which it would
rise in a cyhndrical tube whose diameter is equal to the thickness of the annular space.
Hence also between two parallel flat plates, which may be regarded as cylinders of in-
finite radius, the height to which a hquid rises is half that in a cylindrical tube whose
diameter is equal to the width between the plates.

The following table shows the height, as determined by Frank en he im (Pogg.
Ann. Ixx. 515), to which different liquids rise in cylindrical tubes of 1 millimetre radius
at 25<' C.

Bcniene .
Oil of turpentine
Oil of lemon
Rock^il .
Oil of cloves
Eupione .
Alcohol .
Ether

Oxalic ether
Acetic ether

Specific
Gravity.

Height

in
mUlim.

0-840

e>GO

0871

6-33

0-8!M)

6-63

0-8S7

6-5a

1030

6-69

0-664

6-72

0-800

8-78

0-716

4-77

1-093

6*05

0-749

6*61

Water . . . •

Sulphide of carbon . .
Trichloride of phosphorus
Disuiphide of chlorine
Trichloride of arsenic
Dichloride of tin
Chloride of nitrogen
Bromine .
Sulphur . •
Mercury . .

Specific
Gravity.

0-997

I'va

l-4»

1-687

2*18

1-34
8-0
2-14
13-59

Height

in
miUim.

14-67
4-84
3-75
4-95
4-07
2-50
3-9
4-5
A-8

-4-6

For the theory of capillary phenomena, we must refer to works on physics {vid,
MuUer, Lehrbuch der Physik una Meteorologies 1853, i 97).

CAWOMOR. One of the constituents of beech-tar, first separated by R e i c h e n-
bach (J. pr. Chem. i. 1). According to Yolckel (Ann. Ch. Phann. Izzxvi 99),
capnomor is contained, together with creosote and another oil, in the portion of wood-tar
which is soluble in potash, and on distilling the alkaline-liquid, capnomor passes over
with the vapour of water. It is perhaps partly formed by the decomposition of the
creosote.

It is a colourless oil, having a peculiar odour, rather lighter than water ; boils
between 180^ and 208^ C. Insoluble in pure water and in potash, but dissolves partially
when creosote is likewise present Contains 81*2 carbon and 7'8 hydrogen ; perhaps
CH^O^ It dissolves in strong sulphuric acid with red-purple colour ; the solution
is decolorised bv water and then contains a conjugated acid. Nitric acid converts it
into prussic and oxalic acid and another crystaUine substance.

CULVOXCX^MCTB. A silicate of calcium and aluminium found in several localities
in Tuscany, both in radiated laminsB and in crystals belonging to the monoclinic
fystem; cleavage perfectly parallel to OP and ooPoo, easy also parallel to ooP. It
has a flesh-red colour with nacreous lustre ; transparent only in thin laminae. Specific
gravity 2-470. Hardness >» 3-5. It splits easily into thin acicular fragments. It
|;ive8 off water when heated in a tube ; and melts with intumescence to a white enamel
oefore the blowpipe. Dissolves easily in adds, with separation of gelatinous silica. Ac-
cording to Anderson's analysis (K. Edinb. PhiL J. zxxiv. 21), it contains 52*8 SiO',
21-7 aPO*, 01 Fe*0», 11-3 CaH), 11 K«0, 0-2NaK), 0*4 Mg«0 and 131 BPO (- 1007),
agreeing nearly with the formula CaH).Al*0'.4SiO' + 3 aq. It appears to be a variety
of Laumontite formed by weathering.

CAVFAXXS UWTMQBAm A shrub growing in the south of Europe, the root-bark
of which is said to contain a neutral bitter principle of sharp irritating taste, and
resembling senegin. The flower- buds pickled in salt and vinegar form capers. Dis-
tilled with water they yield a distillate having an alliaceous odour. After they have
been washed with cold water, hot water extracts from them capric acid and a gelatinous

3d 3

742 CAPBAL — C APBIC ALDEHYDE.

sabstanoe of the pectin gronp. Gaprie acid ia sometimes foimd deposited on the ealices
of the bads in white specks having the i^pearanee of wax. (Bochleder and Bias.)

CAVKA&. A term applied sometimes to ei^iroic^ sometimes to capric aldehyde
(see those compounds).

CAntAMODB. Caprinamide, C**H"NO » N.C*«H»O.H*.— The primaiy amide
of capric acid, prodnoed by the action of strong ammonia, on an alooholie solution of
caprate of ethyl. When purified by ciTstallisation from alcohol, it forms oolourlesa
shining crystalline scales, which haTe a silky lustre when dry, are insoluble in water
and in aqueous ammonia, but dissolye readily in alcohoL (Bo wne j, Ann. CL Fharm.
Uxix. 231.)

CAVmxC ACZD. BtOic Acid. C~H>*0'. (am. ziy. 485.)h-This add was flzat
discoTcred by CheTreul in the butter of cow's milk. It is contained in ooooa-nut oil,
and in seTeial kinds of fusel oil ; it occurs amoDS the products of the distillatiop of
oleic acid and of choloidie acid, and is also formed by the oxidation of oleic add and
of oil of rue.

According to Bowney, it is obtained pure and in tolerable qnantity fiom the reaidne
which remains in the distillation of fusel oil, after the amylic alcohol has distilled off
at 132^ C. The caproic add is present as capeaXe of amyL When this residue is de-
composed by boiling with caustic potash, the amylic alcohol distils over, and the residue
oontains caprate of potassium. (Jn the addition of hydrochloric acid, capric add is
liberated as an oily mass, which is washed with water and dissolved in dilute am-
monia. The caprate of ammonium is mixed with chloride of barium, and the in-
Holuble barium-salt which predpitates is filtered oS, washed with cold, and dissolved in
boiling water : on cooling, caprate of barium is depodted almost pure. To obtain the
acid, this salt is treated with carbonate of sodium, and the solution of cerate of
iKxlium is filtered from the carbonate of barium, then decomposed with sulphuric add,
which throws down capric add almost colourless, and in the solid form. It is purified
by solution in alcohol and repredpitation by water.

The CiLPAATBS are mostly dii&eultly soluble in water.

Caprate of Barium, G**H''BaO', is almost insoluble in cold, but soluble in boil-
ing water, from which it separates in needle-shi^ied or laige pciamatic crystals, which
float on water if not moistened.

Caprate of Calcium, C"H^*CaO', fidls as a white insoluble powder when caprate
of ammonium is mixed with chloride ol caJnnm It is more difficultly soluble in boil-
ing water than the barium-salt, and crystallises in beautiful lustrous lamina*.

Caprate of Magneaium resembles the caldum-salt.

Caprate of Lead is predpitated as a white amorphous powder when caprate of
sodium is mixed with acetate of lead. It is very little soluble in boiling aloohoL

Caprate of Silver is predpitated on the addition of nitrate of silver to caprate of
ammonium. It is but slightly soluble in boiling water, and is deposited on cooling in
needle-shaped crystals. When moist^ it is readily changed by exposure to lighL

Capra te of Sodium \b readily soluble in water and alcohol. On evaporation it is
obtained as a homy mass, presenting traces of oystallisation. It is easuy scduhle in
hot absolute alcohol, forming an opalescent mass.

Caprate of Ethyl Caprie ether, C>«H:i*(CH*)0', is formed by dissbivi]^ eaprie
acid in absolute alcohol, saturating the solution with dry hydrochloric add gas, and
then mixing with water. It separates as an oily layer, which, when washed with
water, forms a colourless Uquid of specific gravity 0*862. £w A

CAVBaco AUDXBna. C>*H*H).— The aldehyde of cun^add has not yet
been obtained with certainty. It was formeriy supposed, aoooroing to the reanlts of
Gerhardt (Ann. Ch. Phys. [3] xxiv. 96) and Wagner (J. pr. Ghem. zlvi 16$ ; liL 48),
to be the chief constituent of oil of me, but aooording to Gr. Williams (PfaiL TransL
1858, p. 199), this oil consists mainly of emodic aldehyde, 0"H^. This result, so fst
as regards the quantitative constitution, has been confirmed by Hallwaehs (Ann. Ch.
Pharm. cxiii. 107), who, however, maintains that the body C^H'H) is not an aldehyde.
According to more recent statements by Wagner, on the contrary, oil of roe is really
capric aldehyde, and forms with ammonia a compound which, whoi treated with sul-
phydric add, yields thiocaprie aldehyde, C^H^S^N, and with hydrochloric and Inrdro-
cyanic add a compound homologous with alanine. (See Biis, On. of.) (Handw. d.
Chem. 2« Aufl. ii [2] 741.)

See Cafbamtob.
Syn. with CAPORCiAKm.
Syn. with Hbxtlenb, CH".

CAPROIC ACID. 748

CAVBOIC ACZB. C*H"0>. (Gm. xi. 414.)— This acid, the sixth in the aeries
of £itty acids, was first discorered by Cheyreol in the butt«r of cow's milk, in which it
exists in combination with glycerin. It exists in considerable quantity in cocoa-nut
oil, and in cheese, and is a not unfrequent product of the oxidation of the fatty acids of
hi^er atomic weight; it is also obtained by the oxidation of poppy oil and of casein.

From cocoa-nut oil it is readily obtained by saponification with soda-ley of spe-
cific gravity 1*12. The soap is decomposed by sulphuric acid, and rapidly distilled
from a copper retort The distillate, which consists essentially of caproic and caprylio
acids, is neutralised with baryta, and the solution eraporated to crystallisation. The
crystals which firat form are capiylate of barium ; when the solution is further erapo-
rated and allowed to stand, caproate of barium is obtained in verrucose crystals. The
salt purified by oystallisation and decomposed by a stronger acid, yields caproic acid
in an oily form.

The best method of preparation is that of Fnmkland of Kolbe^ yix. the decomposi-
tion of cyanide of amyl by potash :

Cra"N + KHO +H»0 - C«H»»KO« + NBP.
Cjranida Caproate of Ammonia,

ofamyl. poCaasluni.

The process as modified by Wurtz, is as follows : — To prepare cyanide of amyl,
the black mass obtained by calcining ferrocyanide of potassium in a covered cru-
cible, is placed in a retort connected with the lower part of a Liebig's condenser,
together with four or fixe times its weight of alcohol, and the mixture is heated to boil-
ing. A quantity of iodide of amyl, not quite sufficient to decompose the cyanide, is
then gradually introduced through a funnel-tube, and the boiling is continued till the
decomposition is complete. This point is ascertained by allowing a drop of the oil
which separates on the addition of water, to evaporate on the end of a glass rod held in
a flame : the presence of the smallest quantity of iodide is perceptible by the brown
vapours of iomne produced. When the conversion of the iodide is effected, the alco-
holic liquor is mixed with excess of water, and the oil which separates is boiled with
alcoholic solution of potash in a retort connected with the lower end of a Liebig's
condenser, until it is completely decomposed into ammonia and caproic acid. The ca-
proate of potassium is then decomposea by a stronger add, and the oily layer removed
and distilled.

Caproic acid is a clear mobile oil of specific gravity 0*931 at 16^ C. It has a sudo-
rific odour and penetrating acid taste. Sparingly soluble in water, but dissolves
completely in absolute alcohol. The acid prepared from cyanide of amyl solidifies at
— 9^ C, and boils at 198^, and according to Wurtz, has the property of circular pola-
risation. That from cocoa-nut oil boils between 202^ and 209^ (probably owing to an
admixture of capiylic acid), and does not affect the plane of polarisation.

Caproic acid is dissolved by sulphuric acid withoat change in the cold, and is again
liberated on the addition of water. A concentrated solution of caproate of potassium,
when subjected to a current from six of Bunsen's elements, is electrolysed in a manner
analogous to valerate of potassium. The oil which separates on the surface contains
amyl, CH**, together with another body, which is probably caproate of amyl, result-
ing from a secondary decomposition :

2C^»K0« + O - C"H« + K«CO» + CO*.
Caproate of Amjrl. Carbonate

potassium. of potauium.

or2C^"KO« + O + H'O - C'»H« + 2KHC0".
Caproate of Amyl. Ae!d carbonate

potassium. of potassium.

Capiioatbs. — The salts of caprie add resemble the valerates, and are obtained in a
similar manner.

Caproate of Ammonium^ obtained by saturating caproic acid with ammoniacal
gas, is a crystalline salt, irhich, by absorbing more ammonia, again deliquesces.

Caproate of Barium is obtained by saturating the add with carbonate of barium.
By spontaneous evaporation of the solution below 18^ C. it crystallises in lustrous
hexagonal limiipi>f^^ which become milky in the air. Crystallised above 30^ C. it forms
needles often of some lenz^. It dissolves in 12*6 pts. of water at 20^ €$. In moist
air it smells of caproic add, and its aqueous solution deposits a basic salt when boiled.
When distilled it yields combustible gases, among which propylene, C*H', is present
in greatest quantity, and an oil passes over which contains propione, C"H'*0. The
residue consists of carbonate of barium and charcoal.

Caproate of Calcium forms lustrous square laminse, whidi are soluble in 49 pts.
of water at 149 C., and fuse on being heated, emitting an odour like that of the
LabiaUe*

3b 4

744 CAPROIC ALDEHYDE — CAPRO YL-

Caproate of Magneaiunk, C5«H"MgO« + aq^ crystallisea in Bmall aggregated
needles, which retain 1 at of water when heated above 100° C.

Caproate of Potaaaium, C*H"KO', is obtained by the spontaneoiis evaporation
of its solution, as a transparent jelly, which becomes opaque when warmed.

Caproate of Silver, C*H"AgO^ is obtained by precipitating an aqueous solution
of the barium-salt with nitrate of silver, as a white precipitate, spuingly soluble in
cold water. After being washed out with cold, and then dissolved in boiUng water, it
separates on cooling in magnificent crystalline laminee, which are unaltered by light.

Caproate of Sodium, CH^NaO', resembles the potassium-compound. Its
aqueous solution forms a white uncrystalline mass on evaporation.

Caproate of Strontium, C*H"SrO', crystallises in transparent laminae, which
effloresce in the air. £• A.

OAntOZO A&COBO&. See Hbxtlic Alcohol.

CAVKOZO A&]>mm>B. Hydride of Caproyl, G*H'K) » C*H"O.H.— This
compound appears to be produced in small quantity in the dry distillation of caproate of
calcium or barium, being found chiefly in tne first portion of the distillate obtained by
the rectification of crude caprone. (Braiier andGossleth, Ann.Ch. Pharm. Ixx. 256.)
CAVKOZO AVSmXZBB or Anhydrous Caproic Acid, C^'H'K)' = (C*H"0)H).
—According to Chiozsa, this body is prepared by placing 6 at caproate of barium in
a retort^ and gradually adding 1 at oxychloride of phosphorus. The mass becomes
warm and pasty; on cooling it is extracted with pure ether; the ethereal solution
is agitated with weak potash, then dried over chloride of calcium ; and finally the ether
is evaporated in the water-bath.

Caproic anhydride is a neutral oil, lighter than water, and with an odour resembling
caproic acid. When heated it volatilises, emitting an aromatic odour, and leaving a
slight carbonaceous residue. £. A.

CAPROZC BTBBBO. Caproate of Methyl, CH"(CH^O*, is obtained, accord-
ing to Fehling, by mixing 2 pts. each of caproic acid and of wood-spirit with 1 pt^ of
sulphuric acid, and gently heating the mixture. The liquid is mixed with water, and
the supernatant oil is washed with water and dried over chloride of calcium. It is
a colourless liquid of specific gravity 0*8977 at 18° C. ; boils at 150° C. Its vapour-
density is 4*623.

Caproate of Ethyl, C*H"(C^*)0', is obtained like the preceding compound. It is
a transparent liquid, with a pine-apple odour, somewhat resembling butyric ether, but
not so delicate. Its specific gravity is 0*882 at 18° C, and it boils at 162° G. Its va-
pour-density is 4*97.

Caproate of Amyl. C^"(C*H")0'. — Crude caproic acid (prepared by Frankland
and Kolbe's method), the greater part of which passes over at 198° C, contains an ad-
mixture of caproate of amy I. On continuing the distillatioB, it passes over at 212° 0.
It may also be obtained by neutralising the crude acid with carbonate of potassium,
whereupon it remains undissolved as an oily layer. Bemoved, dried over chloride of
calcium, and rectified, it is obtained pure, and of constant boiline point at 211° C. It
is insoluble in water, but soluble in all proportions in alcohol and ether. It is decom-
posed by potash into caproate of potassium and amylic alcohoL £. A.

OAVSOn. C^'H'K) ? When caproate of barium is submitted to destructire dis-
tillation, tritylene and other gases are given ofi^, and a colourless oil passes over. If
this oil be dried and rectified, it begins to boil at 120° C, and the thermometer ulti-
mately rises to 160° — 170°C. By rectification, a product is obtained, boiling con-
stantly at 165° C. It is a colourless oil, lighter than and insoluble in water, and having
a peculiar odour. It is readily soluble in alcohol and ether, becomes brown in the air,
and is attacked by nitric acid even in the cold, nitrovalerie acid, C*H*(NO')0', being
apparently formed.

The boiling-point of this compound (164° C), differs widely from that calculated for
caprone, 232°, and it is hence doubtful whether it ia the true caprone.

O/kVSO Ji X'l* HZUia C*H"N. This compound, which contains the elements of
caproate of ammonium minus water [C*H'^^NH^)0'~2H*0], has not been obtained
directly from that salt The isomeric (or identical) compound, cyanide of amy),
C*H".UN, is obtained by heating an alcoholic solution of iodide of amyl to the
Ixnling pointy with excess of ^anide of potassium. (See Ctanidbs op Axoohol-
Radiclbs.)

CAMtOVOIX. A name applied by Weltzien to the radide CH*', which may be
supposed to exist in caproic aldehyde, C*H".H.O, and in caprone, C»H".C*H".0.

OJkrWtOlTL (or Capronyl, according to Weltzien), C*H"0. — ^The radicle of caproic
add and its derivatives : e.y. caproic acid » C'lf 0.H.0 ; caproic aldehyde, C*H'*O.H ;

CAPRYL — CAPRYLIC ALCOHOL. 745

captone^ C*H"O.0*H", &c. The same term is also sometimes applied to the corre-
qwnding alcohol-radicle OH'* ; but it is much better to designate this radicle by the
name Hexjl, aa proposed bj Gkrhardt (See Hbxtl.)

CJkraOT&AKZVa. See HsxTLAxnns.

OJkWMOTltMMMm See Hbxtlbnb.

CUUranx or KUTTZ% C**H"0. — The radicle of capric or mtic acid,
O«H**0.H.0, and its deriTatives. The same term is applied to C*H"0, the radicle
of ci^prylie acid : it is better however to call the latter capr^ly 1, unless indeed the
term capric acid be altogether abandoned, and rutic acid substituted for it. 0'*H'*0
would tnen be called rutyl, and CH*H), capryL There is at present great confusion
between the names of these radicles, which u further increasea by the application of
the same name, eapryl, to CH", the radicle of the 8-carbon alcohol, for this last-
mentioned radicle we shall use Gherhardt's name Octyl (q, v.)

See OoTTUkJONB.

See OCTTLBMB.

C»H'«0« « C»ff»O.H.O (Gm. xiiL 190).— Ci^iyUc acid was
discovered by Lerch, in the butter of cow's milk. It is also contained m cocoa-nut oil
and in Limburg cheese ; in several kinds of fusel oil it occurs partly free and partly
in combination with ethyl and amjL

The best source for this acid is cocoa-nut oil : from the difficult solubility of its
barium salt^ it is easily separated from caproic add, with which it is associated (see
Cafboio Acm). The caprylate of barium is purified b^ recrystallisation ; its aqueous
solution decomposed hj sulphuric acid ; and the oily hquid which rises to the sui&oe
is washed and distilled : the distillate between 230 and 238^ GL is pure capiylic acid.

CapiTlic add has a feeble but unpleasant odour, which is more perceptible when
the add is warm. It solidifies at 12^ C, melts at 15^, and as the liquid slowly cools,
laminss resembling cholesterin form in it At 20^, its specific gravity is 0*911. It
boDa at 236° — 238** ; its observed vapour density is 5*31 (calculated 4*98).

Caprylic add is monobasic, the general formula of its salts being CVMO*.
Caprylate of Barium, C*H"BaO', crystallises from a hot aqueous solution, in fine,
white, &tty lamins ; by spontaneous evaporation, in small white grains. It dissolves
in 50 pts. water at 100° C, and in 126 pts. at 10°, It is quite insoluble in alcohol and
ether. It contains no water of crystallisation, and can be heated to 100° without
change.

Caprylate of Lead, CH"PbO*, is obtained on mixing caprylate of barium with
nitrate of lead. Is a sparingly soluble predpitate, which melts at 100° C.

Caprylate of Silver, prepared in the same manner, is whit« and insoluble. E. A.

Suhstiiution-derivative cf Caprylic Acid.

NiTBOCAPBTLio AoD. C«H»»NO* - CTr»(NO«)0« (Wira, Ann. Ch. Pharm. dv.
289). — ^This add is produced by the continued action of nitric add at the boiling heat on
the mixture of non-volatile faUjradds which is obtained from cocoa-nut oil by saponify-
inff the oil with soda, decomposing the soap with sulphuric add, and distilling off the
ToUtile adds. After washing the product with hot water, till the grains of sub^c add
mixed with it are removed, there remains a heavy oil, containing nothing but nitroca-
piylic and nitrocapric acids. The add thus obtained is a yellowiah-red, syrupy oil, hav-
ing a peculiar odour and bitter taste, of specific gravity 1-093, at 18° 0. ; it dissolves
sparingly in water, more easily in stzong nitric add. When heated, it becomes dark-
co]oure<i, and decomposes, with evolution of nitrous add, and at a higher temperature,
detonates slightly.

Nitrocapiylie acid neutralises alkalis completely. With ammonia, it forms a yel-
lowish-iecC and with potash a deep red solution, leaving an uncrystallisable mass
when evaporated. The ammonia-salt yields with salts of caldum, barium, lead, and
copper, flaky predpitates, which form a viscid mass when stirred. The silver-salt,
0'H'*Ag(NO»)0' is precipitated in yellowish-white flakes, which dry up to ayeUowish-
grey mass.

OAVSTXIO A&OOBOlto See Octtlio Alcohol.

I. Hydride of Caprylyl, Cm»0 - C^»»O.H.--A body
having this composition and capable of uniting with tne acid sulphites of alkali-metals,
is obtained, among*other products, by the diT distillation of castor-oil soap (ridnoleate
of sodium or potassium), dther alone or with excess of alkali It was flrst obtained
by Limpricht (Ann. Ch. Pharm. xciii 242), who regards it as caprylic aldehyde;
afterwards examined by Bonis (Ann. Ch. Phys. [3] xlviii. 99), who takes the same
view of its constitution; and farther by Stadeler(J. pr. Chcm. Ixxii. 241), and by

746 C APRYLIC ANHYDRIDE — C APRYLIC ETHERS.

Dachaner (Ann. Gfa. Fhann. cvL 270), wlio rceaid it as an acetone, tIz. methyl*
OS nan thy 1, CB^.CWO, According to Bonis, me aldehyde ia fanned, together with
an acid (G**H'*0'), and without evolution of gas, chiefly when castor-oil soap is slowly
heated to a temperature not exceeding 225^—230^ 0^ and without esfcen of alkali:

Ridnoleic Caprylic New acid,

add. aldehydeu

whereas if the soap he quickly and stroi^Iy heated, espeeially with ezoess of alkalit
hydrogen is ahundantly evolved, and octylic alcohol is pn)duced, together with sebacie
acid (see page 98). Malaguti obtained sometimes ocfylic alcohol, sometimes caprylic
aldehyde, but always sebacic acid ; he explains the formation of these products by the
equations :

Ci»H»*0« + H«0 + O - CWBP»0 + CP'ffW

Ridnoleic Oetrlic Bebade

add. aicohoL add.

Caprrllc
aldahyde.

3tadeler and Dachauer likewise obtained sebacic add in eveiy ease (p. 98).

Caprylic aldehyde is also produced by distilling a mixture of capiyiate and Sannate
of calcium (Limpricht):

"^'Sjo - TJo - cw . ^-^l

To prepare pure caprylic aldehyde, the crude distillate obtained by heating castor-
oil soap with excess of hydrate of potsssium, is treated with a strong aqueous solution
of acid sulphite of sodium ; and uie resulting crystalline mass is lepestedij pressed
between paper, washed with alcohol, dried over sulphuric acid, and dissolved in hot
water, whereby it is decomposed, and capnrlic aldehyde set free : it is then dried over
chloride of calcium and rectified. According to Bonis, it is better to distil the neutral
soap per se^ or better still, the barium-salt formed from it, because the latter does not
froth.

Caprylic aldehyde is a colourless, strongly refracting liquid, having an aromatic
odour and caustic taste. Specific gravity 0*818 at 19° C. (Bonis). Boiling point
178° (Limpr ich t) ; 171^ under ordinary pressure (Bonis). It is insoluble in water.
It bums with a bright non-smoking flame ; becomes acid when warm air or oxygen is
passed through it (Bonis) ; and is violently oxidised by nitric acid, with formation
of caprylic acid and other fatty acids ; chromic acid also partly converts it into an
acid. Heated with solid potasn, it forms a brown spongy mass. With ammoniacal
nitrate of silver it forms a metallic mirror. With pentaduoride of phosphorus, it forms
chloride of octylene, C«H'«C1«.

Caprylic aldehyde unites with add sulphites of alkali-metals, without rise of tempe-
rature. The compounds are insoluble in excess of the add sulphite, and are decom-
posed by water. The sodium-salt contains 2C«H^«0.2NaSO».SO* + 2 aq.

CAVKTXiZO AVHTBBISa. Anhydrous Caprylie add, C'^H'K)'. =(C^»0^.
— This body is obtained by treating 6 at capiyiate of oarium with 1 at. of oxychloride
of phosphorus. Much heat is disengaged, and the mixture is changed into a pas^
mass, developing a peculiar and unpleasant odour, which probably arises from chloride
of caprylyL From this pasty mass, the anhydride is extracted by treatment with
ether, wUch must be free from alcohol. The ethereal solution is agitated with dilute
potash-ley, in order to remove caprylic add, and then dried over (£loride of caldum.
On the evaporation of the ethereal solution, the anhydride is left as a dear mobile oU,
lighter than water. When freshly prepared, it has a sickly odour, which is more
evident when it begins to pass into capiyUc add. When heated, it gives off vapours
which attack the throaty but have an aiomatic odour. In a frecxing mixture, it
solidifies to a white mass of imperfectly crystalline texture. It begins to boil at
280^ C, the temperature gradually increasing to 290°, when the liquid begins to de-
compose. Boiline water does not convert it into ci^rylic add, but when left for some
time in contact with moist air, it gradually changes into that substance. Potash-ley
^aduaUy changes it into caprylic add. (Chios za, Ann. Ch. Pharm. lixiv. 229).

£. A.

CAMTUCO STBSS8. Caprylate of Methyl, C»ff*(CH«)0», is formed,
when caprylic add dissolved in its own weight of methylic alcohol is mixed with a
quarter of the weight of sulphuric add The liquid immediately becomes turbid, and
the caprylate of methyl forms a light oily layer on the surface, It is removed, washed
with water, and dried. It is a colourless, highly aromatic liquid, with an odour of
wood-spirit. Its spedfic gravity is 0*882, and vapour-density 6*48. It is scaroely
soluble in water, but dissolves readily in alcohol and in ether. (Fehling, Ann^Gh.
Pharm. liiL 406.)

C APRTLONE — CARAMEL. 747

Caprylate of Ethyl, C*ff*(0'H»)0», is prepared like the preceding oompoand.
It 18 a oolonrless liquid, with a pine-apple odour. Its specific gravity is 0*8738 at 15°.
It boils at 214° 0. Vapour-density -» 6*1. It is insoluble in water, but soluble in
alcohol and ether. (Fehling). E. A.

OAPKT&on. This name has been given to a substance which Guckelbeiger
obtained by the destmctiye distillation of caprylate of barium, in quantities oi about
half an ounce, with excess of lime. White vapours pass off, and condense in the re-
ceiver to a ^eUow oily liquid, which after some time solidifies to a yellow buttery mass.
By appropriate purification, it is obtained as a white crystalline body, like Ohinese
wax, and of feeble waxy odour. It is Tery soluble in alcohol and ether, whether hot
or cold. It melts at 40° C, and solidifies at 38° to a radiating crystalline mass. It
boils at 178°, and distils without alteration.

The boiling-point of eaprylone, as calculated firom that of its homologue osnanthylone,
would be 80(^0. The discrepancy between this number and 178°, the boiling-point
of capiylone, seems to prove that this is not the true acetone. Fiurther experiments
are necessary to decide tiie point £. A.

G"H*K). The radicle of eaprylic add, &c.

IVBSA VABTOXZ8. 8kephercP» Pter««.— The green parts of
this plant contain an acrid sulphuretted volatile oil (oil of mustard ?) waxy and fatty
matter, saponin, tannin, tartaric, citric, and malic acids, colouring matter, and traces
of sugar. 100 pts. of the air^dried herb yielded 9 per cent of ash containing sand,
the composition of which, in 100 pts., after deducting the charcoal, was found to be :
15*7 KK), 8*8 NaH), 14*7 Ca«0, 81 Mg«0, 19 FeW, 01 A1*0», 16*2 C0«, 6*2 80»,
8*4 PH)^ 4*2 CI, 20*6 SiO< and sand. (Daubrawa, Eepert Pharm. xdx. 127.)

The seed yields by distillation with water, a volatile oil, which, according to Pless,
is identical with oil of mustard. Axsoording to G. J. MiUder, the seed contains in
100 pts. : 28*8 fixed oil, 26*5 albumin, 12*3 non-nitrogenous soluble matter, 16*0 woody
fibre, 11*6 water, and 4*8 ash. According to Neuburger, the seed contains 20 per cent.
of oil and 28 of albumin. (Handw. d. Chem. V Aufl. ii [2] 780.)

OAPflZOnnb An alkaloid obtained from Spanish peppex, the fruit of Ca^pHcum
aumuum, TBraconnot, Ann. Ch. Phys. [2] vi. 1; Witting, Buchner^s Repert xxxri.
15 ; Landerer, Vierteyahrs. pr. Pharm. iii. 34.) The same name is applied in
America to an oleo-resinous extract from Cayenne pepper {Capsicum baooatum),

CAFirX BIOWmUM. An old term for the residue of a distillation or subli-
mation ; thus the impure ferric oxide obtained as a residue in the distillation of Aiming
sulphuric add from ferrous sulphate, was called Caput mortuum vitrioli.

Irish pearl moss. (Spharoccus crispus.} — An alga,
found in abundance on the coasts of the Atlantic and the North Sea, It is used as
food, as a remedv in chest complaints, and for the clarification of turbid liquids. It
swells up considerably in cold water, and dissolves almost wholly on boiling. The
decoction forms, on cooling, a jeUv having a faint saline taste, and the peculiar odour
of sea-weed. According to Herberger, it contains 79*1 per cent gelatinous matter,
partially soluble in cold water, perfectly in hot water, insoluble in alcohol and ether ;
9*5 mucus, insoluble in water, alcohol, and ether; 07 resin; 1*3 chloride of sodium ;
0*7 chloride of magnesium ; 8*7 skeleton, consisting of cellular substance and salts.

According to Schmidt (Ann. Ch. Pharm. IL 56), the mucus obtained by precipitating
the aqueous decoction with alcohol containing hydrochloric acid, pressing tae pre-
dpitate, and washing it with alcohol, contains 44*8 carbon to 6*2 hvdrogen, (whence it
appears to be a hy<&ate of carbon, like sugar, starch, &c,) and leaves, when burnt,
10*30 per cent ash, chiefiy consisting of sulphate of caldum. The skeleton of caragheeu
moss leaves on incineration an ash containing sulphate and phosphate of calcium,
and, according to Sazphati, likewise metallic iodides. (Handw. d. Chem. 2** Aufl. ii.
[2] 782.)

OAMAUmUf catAJmtVf or CABCmtV. A red dye-stuff, imported from
Para in Bracil^robably identical with cMca-red, which is obtained from the leaves of
the Bignonia Chica, Carajuru appears, however, to be superior to ordinary chica, and
is perhaps distin^shed from it by greater purity. According to Virey (J. Pharm.
1844, p. 151) it IS a light mealy powder, destitute of taste and smell, and acquiring a
coppery lustre "by^ trituration. It is insoluble in water, soluble in alcohol, etiber, and
alkalis, and predpitated from the latter by adds in its original state. Bums with
flame, leaving a considerable quantity of ash.

OAmABODb. (Piligot, Ann. CL Phys. Ixvii. 172.— G^lis, Ann. Ch. Phys. [3]
liL 352.) — A product of the action of heat upon sugar. When cane-sugar is heated in
an oil or metal bath to between 210° and 220° C, care being tfJcen not to exceed the
latter temperature, it assumes a brown colour of continually increasing depth, without

748 CABAMEL.

giving off anj permanent gas ; Taponr of water ia, howerer, erolred, containing traeea
of acetic add and an oily substance. When the tumefaction has ceased, the reaael
is found to contain a black substance, which dissolTes oompletelj in water : this is
carameL To obtain it pure, it is dissolved in a small quantity of water and prec^taled
bj alcohol It maj also be obtained from glucose, but not so readily.

Caramel when pure is insipid ; its aqueous solution has a rich sepia tint* It is in-
soluble in alcohol ; does not ferment under the influence of yeast ; it yields copious
precipitates with ammoniacal acetate of lead and baryta-water. When stzong^y heated
it yidds the same products as sugar. (P^ligot.)

Caramel was long regarded as a simple proximate principle of the formula C^^^'O^,
the precipitate which it forms with barjrta-water havmg the composition CH^^BaO*.
But, according to G^Iis, caramel prepared as above is a mixture of several coloured
substances, some soluble, others insoluble in water, amongst which he particularly dis-
tinguishes three, viz. earamelane, C"H'*0*, caramelem, CQ'^O", and etamdin,
(^*H***0**. All these substances are produced from sugar by elimination of the ele-
ments of water, the atomic weight being at the same time increased, thus :

8C'«H«0" - 37fl*0 - C*«H*«K>»»;
Sugar. CanaMlln.

and by keeping sugar for some time at 190^ C these products may be obtained one
after the otoeT. If ciystallised cane-sugar be used, the residue, after 10 per oent^ has
been given off as water, consists of nearly pure earamelane; after 14 or 15 per cent^
has gone of^ the residue is rich in caramelene ; and after a loss of 20 per cent it
consists almost wholly of caramelin. Grape-sugar yields products nearly resemhlii^
but not identical with these.

Caramelane maj also be obtained pure by digesting ordinazy caramel with 84
per cent, alcohol, which sometimes dissolves it completely, sometimes leaves a residue
amounting to 40 per cent ; treating the solution (which contains caramiJanf^ unde-
composed sugar, and sometimes a little caramelene) with yeast to decompose the sugar
by fermentation ; evaporating the filtrate to dryness ; redissolving in alcohol, which
then leaves the caramelene undissolved ; and evaporating the solution.

Caramelane, to which ordinary caramel chiefly owes its characteristic pn>pertie!i, is
a brown substance hard and brittle at ordinary temperatures, veiy soft at 100^ C^
odourless, with a strong bitter taste, deliquescent^ very soluble in water, moderately
soluble in aqueous alcohol, roarin^y in absolute alcohol, insoluble in ether. It reduces
cupric oxide in alkaline solution, also gold and silver from their salts. Kitric acid
converts it into oxalic acid. The aqueous solution does not precipitate metallic salts.
The alcoholic solution forms, with an alcoholic solution of neutial acetate of lead, a

Jrellow precipitate containing C"H"Pb*0* ; with an ammoniacal solution of acetate of
ead, added in sufficient quantity to produce complete precipitation, it yields the
compound C"H'*Pb'0*.Fb'0 ; and with excess of a solution of baryta in wood-^irit^
a precipitate containing C'*H"BaH>*.BaK). At 190^ C. caramelane givee off water and
passes into caramelene (G61is). Volckel (Ann. Ch. Pharm. Ixxxv. 69) applies the
term caramelane to the black residue, insoluble in water, left on heating sugar to
250° — 300° C. Tlus residue is insoluble in alcohol, sparingly soluble in potash, and
has, according to Volckel, the composition C^H'O". It is periiaps identical with the
substance here called caramelin.

Caramelene. 0"Jl"*0". — The residue left aft«r treating carainel with alcohol of
84 per cent contains caramelene, which may be extracted by cold water, and sepa-
rated from the solution by evaporation or by precipitation with absolute alcohol, and
freed from a small quantity of admixed caramelin by redissolving it in water. It is
solid and brittle, of the colour of mahogany, not hygroscopic, easily soluble in water
(exhibiting a colouring power six times as ^reat as thifit of caramelaiie) and in dilute
alcohol, sparingly in strong alcohol, and insoluble in ether. It reduces cupric oxide
from an alkaline solution, and is converted by nitric acid into oxalic add. Its barium^
compound, precipitated by alcohol, is composed of CH^aK)". With lead it forms
the three compounds C"H*«Pb*0» C*H*Pb«0» 3Pb«0, and C"H«PbK)».5PbH).

Caramelin, CH**K)", exhibits three isomeric modifications, viz. A, soluble in
water; B, insoluble in water, soluble in other liquids; C, insoluble in all ordinary
solvents. The modifications JB and C are contained in the residues left after treating
caramel with cold water; and from these residues B maybe extracted by boiling
water (B then passing into A) by 60 per cent alcohol, or by alkaline liquids. Cara-
melin separates from a hot aqueous solution on evi^ration in films, by precipitation
with alcohol as a copious precipitate, but in both cases as the modification B: similariy
when precipitated by acids from alkaline solutions. But when caramelin B is drit^
or even left for several days in the moist state, it passes into the modification C, and
is then insoluble in all solvents. Caramelin B, which is insoluble in cold water and in

CAR ANNA — C ARB AMIC ACID. 749

stiong alcohol, diasolres in a miztore of those two liqtiids. Its colouring power is 12
timea as great as that of caramelane.

Caramelm is a black, shining, infusible substance. Like caramelane, it reduces gold
and silver from their solutions, and cupric oxide in its alkaline solution. Its solution
is precipitated by nearij all metallic salts. It forms the compounds C*'H***Ba*C>*\
C"H»"BaK>"JBa»0, and C^^PhW*. (G^lis.)

Haumeni (Gompt rend, tyiit. 422) designates by the name caramelin a black-
brown compound, C"H'0^ insoluble in water, acids and alkalis, obtained by mixing 1 pt.
of sugar with 15 to 30 pts. dichloride of tin, evaporating to dryness, and heating for a
few minutes to 120° — 130^ C. ; also by similar treatment of glucose, cellulose, dextrin,
and other hydrates of carbon of similar constitution. Yolckers caramelane (p. 748) is
probably the same as Gilis's caramelin.

CSARAWA* A resin obtained from the Bursera gumm^tra. It is sent into the
market in pieces wrapped in leaves; is grey-black outside, dark brown within ; has a
shining fracture ; is brittle and easily powdered. It melts when heated, emitting an
aromatic smelL It has a bitterish taste. It resembles resin of guaiac in some respects,
and was at one time in repute among the Germans for smoking in pipes, as a remedy
in gout. A distilled oil of caranna was also prescribed for a lOce purpose. It is now
disused.

CSAXAFA B 1111^1 The bark of a tree indigenous in Guiana and Hispaniola,
called Carapa ffuianensia, Personia guareouUs, and Xyloearpus Carapa, It has a
bitter taste, like that of cinchona bark, and is used in intermittent fevers. It is said
to contain quinic acid, a red colouring matter, and an organic alkaloid called cara-
pine, which forms crystalline salts with hydrochloric and acetic acids. (Petroz and
Bob i net, J. Fharm. viL 293, 349.)

The wood of the same tree,*which is beantiAilly veined, is much prized for furniture.

In the buric of Carapa tulucana, C aventou («f. Phamu xxxv. 189) found one yellow
and two red dyes, and a bitter principle, which he calls tulucumine.

The root-bark of Carapa molucensis exudes a whitish powder when wounded ; it is
bitter and astringent^ and is said to be used as a remedy against cholera and biliary
diseases.

CAXAPA Onk A bitter fat oil, obtained by pressure in the heat of the sun
from the kernels of Carapa ffuianenais and C. ttUucana, It is used by the Indians
for protecting the skin against the punctures of insects. It solidifies at + 4° C. and
melts at 10^ ; dissolves sparingly in alcohol, easily in ether ; is saponified by alkalis.
Its bitter taste is said to be due to strychnine, and to be removed by sulphuric acid.
The fruits yield by further pressure, assisted by heat, a fstt which melts at 40° — 6(P C.
(Cadet» J. Pharm. v. 49.— Bouillay, ibid, vil 293.)

CASiAT. An arbitrarv weight by which gold and gems are weighed or estimated.
The diamond carat is equal to 4 grains whereof 612 are contained in the troy ounce ; in
other words, the troy ounce contains 153 diamond carats or 612 diamond-grains.

In estimating or expressing the fineness of gold, the whole mass is supposed to
weigh 24 carats of 12 grs. each, either real or merely proportional, like the assayei^s
weights ; and the pure gold is called fine. Thus, if gold is said to be 23 carats fine, it
is to be understood that in a mass weighing 24 carats, the quantity of pure gold is 23
carats. U.

CAMMAMia JkCXD. CH*NO' - ^^^^^'Jc—This acid is not known in the
free state, neither have any of its metaUic salts, properly so-caUed, been obtained. Its
ammonium-salt, N'H'CO* *» NH^{^' ^ ^^ BO-cnUed anhydrous carbonate of

ammonium, and its compounds with alcohol-radides constitute the dass of bodies
called urethane s: e.g, carbamate of ethyl or ethyl-urethane, C«HTTO«- ^^*^^i| O.

These bodies might also be regarded empirically as compounds of carbonic anhydride
with the corresponding alcohdl-bases: e.ff. ethylurethane as GO' + O'H^ (ethyl-
amine) ; but their formation and properties do not accord with this latter view.

The urethanes are juroduoed, together with sal-ammoniac, by the action of ammonia
gas on the dUorocarbonates of the alcohol-radicles :

C^».C0KI1 + 2NH» - NH*a + C»H».CH^O«
Chloroar. Bthjl-ureUuiM.

booateof
ethyl.

2. By the action of anhydrous ammonia on the corresponding carbonic ethers:

Carbonate Carbamate of Alcohol.

ethjU ethyl.

760 CARBAMIC ACID.

3. B J the action of chloride of cjanogen on the alcohols :

CH».aO + CN.Cl + H«0 «= ^^*^^.lo + HCl

Carbamic acid in which the whole of the oxygen is z^laoed bj snlphnr, eomstitntcs
Bulphocarbamicacid, CH*NS' (q.v,)
There is also an oxysnlphocarbamic acid, the ethyl- and amyl-salts of which

have been obtained, viz. zanth amide, CS* (^ ^^^ zanthamylamide^

^^'c»ri''' { ®" ('^ *^°^ articles ; also page 206.)

CA.RBA.1CATB OP Amkoviuu. Atihydrotu Carbonate of Ammonia^ N^^CC «

NH* { ^' — ^^ ^^ which was discoyered by H. Davy, and farther tntestigated

by J. Davy and H. Rose, is pxoduced : 1. By passing a mixtore of carbonic anhydride
and ammonia-gas through a number of glass tubes cooled to a low temperatnra. In
whateverproportion the gases may be mixed, they always unite in the proportion of
2 ToL NH' to 1 ToL C0^ — 2. By subliming a mixtore of carbonate of sodium and
Bulphamate of ammonium, N'H*SO*, both perfectly diy. (H. Boss.)

It is a white mass which smells of ammonia, has a strong alkaline reaction, Tolatilisca
a little above 60^ C, and condenses again below 60^. The specific gravity of its vapour
is 0-8992 (H. Bose), 0*90 (Bineau). Now 2 vols, ammonia + 1 vol CO*, weig^
1-1787 + 1*5252 -« 2-7039, which is nearly three times the observed specific gravity of
the vapour. Hence the two gases appear to unite without condensation, although not in
equal volumes. Probably the compound exists only in the solid state, and is resolved
by heat into C0« and 2NH?. .

Vapour of sulphuric anhydride converts carbamate of ammonium into sulphamate of
ammonium with evolution of carbonic anhydride. Heated in sulphurous anhydride, it
yields an orange-coloured sublimate. Hydrochloric add decomposes it with aid ot
heat^ yielding sal-ammoniac and carbonic anhydride.

Carbamate of ammonium dissolves readUy in water, yielding a solution which gives
the reactions of neutral carbonate of ammonium, from which, indeed, it dinars only by the
elements of water [N«H«CO«=(N»H*)*CO"-H«0]. It appears, howeverto be capable
of existing in solution for a short time as carbamate ; for on passing carbonic anhy-
dride into aqueous ammonia, taking care that the liquid does not become hot, the
resulting solution does not precipitate diloride of calcium or chloride of barium till
after some time, unless the liquid be heated. This circumstance is of importance in
chemical analysis ; thus, in determining the amount of carbonic acid in a mineral water
by means of chloride of calcium and ammonia, it is necessary to leave the liquid to
stand for some time, or heat it to the boiling points in order to insure that the whole
of the carbonic acid is precipitated as carbonate of calcium. (Kolbe.)

According to H. Bose, ordinary carbonate of ammonium prepared by sublimation
often contains carbamate. (Gm. ii 430).

Cabbah^tb of Amyl. Amyl-urethane, C«H>«NO«-CH*(C*H'»)NO«.— (Medio ck,
Ann. Ch. Pharm. Ixxi. 104.^1. Wurta, J. Pharm. [3] xx. 22).— Obtained by adding
ammonia to amylic alcohol saturated with chlorocarbonic oxide, and washing the re-
sulting crystalline msss with water to separate sal-ammoniac : or by passing gaseous
chloride of cyanogen into amylic alcohol and distilling, chloride of amyl then passing
over first, and afterwards the carbamate.

This compound crystalUses fh)m boiling water in beautiful silky needles, soluble in
alcohol and ether. It melts at 66^ C. and distils without alteration at 220^. Bis-
tilled with caustic baryta, it yields ammonia and amylic alcohol, with a residue of car-
bonate of barium. It dissolves completely in cold sulphuric acid, and is precipitated
therefrom by water. ^ Heated with sulphuric add, it forms amyl-sulphuric add and
ammonia, with evolution of carbonic and sulphurous anhydrides.

Cabbaxatb of Ethh.. Urethane. CH'NO* « CH«(C*H»)NO«. (Dumas. Ann. Ch.
Phys. liv. 233.- Cahours, Compt rend. xxi. 629. — ^Liebig and Wohler, Ann. Ch.
Pharm. liv. 370.— 'Gerhard t, Compt. chim. 1846, p. 120. — ^Wurtz, Compt rend.

xxii. 503, J. Pharm. [3] xx. 19) — ^This compound is prepared : 1. By leaving carbonate
of ethyl in contact with an eqiial volume of aqueous ammonia in a corked fiask till it
completely disappears, and evaporating in a dry vacuum. — 2. By treating chlorocar-
bonate of ethyl with ammonia, and distilling : the action is very violent — ^Alcohol of
ordinary strength is saturated with gaseous chloride of cyanogen; the solution is
heated for some hours in a sealed lone-necked flask placed in a watis^bath ; and the
liquid when cold is decanted from the deposit of sal-ammoniac arising firom a secondary
action, and distilled. Chloride of ethyl then passes over fiist^ then alcohol at 80^ d

CARBAMIC -ACID. 751

(pu 749), after which, the temperature rises, and nrethane passes oyer, oondenGiing in
jaminae.

Carbamate of ethyl forms lajrge transparent colourless ciTstals : eren a few drops of
its Bolution left to evaporate are sure to yield these crystals. It melts below 100*^ C,
ajod distils at about 180^ without alteration if dry ; but in the moist state it suffers
partial decomposition, giving off torrents of ammonia. It dissolves readily in water,
forming a solution which does not precipitate silver-salts ; also in alcohol and ether.
Its vapour-density, by experiment^ is 3'14, by calculation (2 vols.) » 8'08.

CASBAXJL'ni OF Mbthyl. Urethvlane, C*H»NO*=CH»(CH»)NO*.— Obtained like
the preceding compounds. Crystallises in long tables derived from an oblique rhom-
boTdal prism, with very elongated terminal faces. The crystals are not deliquescent,
they melt between 62° and 65° C, and solidify at 62° when perfectly diy. Boiling-point
1 7 7° C. Vapour-density, experimental = 2*62 ; by calculation (2 vol.) « 2*60. It is very
soluble in water, less in alcohol, and still less in ether. 100 pts. of water at 11° C.
dissolve 217 pts. of it, whereas 100 pts. alcohol at 16° C. dissolve only 73 pts. Dilute
sulphuric acid decomposes urethylane into methyHc alcohol, acid sulphate of ammonium,
and carbonic anhydride :

^^^0 + ^:\ 0« + HK) - CH..H.0 + h,|0;jo. ^ ^,

Strong sulphuric acid blackens it, eliminating sulphurous anhydride and inflammable
gases. Potash decomposes it in the same manner as dilute sulphuric acid.

Cabbakatb of Tbtbtl. C^"N0« « CH«(C*H»)NO«.— Obtained by heating te-
trylic alcoholic with liquid chloride of cyanogen, best in a sealed tube, distilling and
collecting that which passes over above 220° C. This distillate solidifies on cooling in
a ciystaUine mass, which, when reciystallised from boiling alcohol, forms shining
nacreous scales, unctuous to the touch, insoluble in water, soluble in alcohol and
ether ; they mdt at a gentle heat and distil without alteration. (Humann, Ann. Ch.
Phys. [3] xliv. 340.)

SubeHtuium'derivaHves of Carbamie Acid.

ETirn>cABBAMic Aero. C^'NO* «^'^(^^*)(^)'| O.—This acid, isomeric

with urethane, is not known in tiie free state ; but its ethylammonium-salt,

^J^5,Jv * [O, is identical with the so-called anhydrous carbonate of ethylamntf

(CH^)'.CO*, obtained by passing carbonic anhydride into anhydrous ethylamine
cooled by a freezing mixture. It is a snow-white powder, whose aqueous solution, like
that of carbamate of ammonium, does not immediately precipitate chloride of barium,
unless aided by heat (Wurtz, Ann. Ch. Phys. [3] xxz. 483.)

Ethylcarhamate of Ethyl, Ethylttrethane. C»H»>NO» » C«H«(C»H»)NO«.—
Produced by heating cyanate of ethyl with alcohol in a sealed tube : 0(C'H*) NO -f-
C^H) «t U*H"NO'; sometimes obtained as an accessory product in the preparation
of cyanate of ethyl. It is an oily liquid, smelling like carbonate of ethyl. Specific
gnvitjr 0*9862. iBoiling point 174—176° 0. Vapour-density 4*071. Potash decom-
poses it, forming alcohol, ethylamine, and carbonate of potassium: C*H'*NO' +
2KH0 - C*H*0 + C^'N + K'CO^. Heated with strong sulphuric add, it yields
carbonic anhydride, sulphate of ethylamine, and probably also ethylsulphuric add.
(Wurts, Compt. rend, xxxvii. 182; Gerh.ii. 929; iv. 869.)

Mbtht]>oabbamic Aero, like the corresponding ethyl-compound, is not known in

the separate state, but forms a methylammoninm-salt^ ^ CH^ [ ^' which

may also be regarded as anhydrous carbonate of methylamine^ (CH*N)*.CO' : it is
formed bv passing carbonic anhydride into dry methylamine, or by distilling a mixture
of ftised hydroduorate of methylamine and carbonate of caldum. In the latter case,
however, it is mixed with carbonate of methylamine. (Wurtz, Ann. Ch. Phys [3]
zxx. 460, 461.)

Phbntl-cabbajuo Aero. CarbanUic Acid. Anthranilio Acid. C^H'NO* *
HH(C^»)(CO)'*|q (Fritzsche, Ann. Ch. Pharm. xxxix. 88; Liebig, ibid.

91 ; Gerland, Chem. Soc Qu. J. v. 183.) — ^This acid, whidi contains the elements of
1 ait carbonic anhydride and 1 at phenylamine, C^'N, and is likewise isomeric with
oxybenzamic add, is obtained by boiling indi^ with strong caustic potash, replacing
the water as it evaporates, and adding peroxide of maneanese before the indigo com-
pletely disappears, till the liquid no longer deposits blile indigo on being left at
rest The mass is then dissolved in wa&r and supersaturated with dilute sulphuric

752 CARBAMIDR

add ; the filtered liquid is neatraliBed with potash and eyaponted to dxyneea ; and the
residue is digested with alcohol, which dissolves chiefly phenyl-carbamate of potassium,
and leaves it in an impure state when evaporated. It is then dissolved in water, acetic
acid added, and the yellow or brownish crystals of phenyl-carbamic add thereby
predpitated are purified by animal charooal and reciystallisation (Fritssehe).
According to Chancel this add. is likewise produced by the action of potash on phenyl-
carbamide.

Phenyl-carbamie add aystalUses in transparent^ colourless, shining prisms or
laminse, often of considerable size. It diesolves very roaringly in cold water, much more
in boiling water, very easily in alcohol and ether. Its solutions have an acid reaction.
It melts at 132° C, and sublimes unaltered. By distillation firom oousely pounded
glass, it is resolved into carbonic anhydride and phen^lamine. It carbonisea when
heated with phosphoric anhydride. Strong sulphuric aad converts it into phenyl-«ul-
phamic add. When nitrous add ^ is piused into its warm dilute aqueous solution
nitrogen is evolved, and the solution yields, when concentrated, crystals of salicylic
(phenyl-carbonic add) :

FheDjl-carbamic acid. Nitrooi Phenyl- carbonic

acid. add.

The metallic phenyl-carbamates are but little known. The calciums-salt, C^*CaNO*,
forms rhombohednil crystals, sparingly soluble in cold, moderately in boiling water. The
silver-salt, CH'AgNO', is deposited in shining lamins on mixing a dilute boiling
solution of the calcium-salt with nitrate of silver. The solution of the ammonium-salt
likewise predpitates the salts of copper, lead, and eino.

Phenyl-carbamates (?) of Ethyl and Methyl, — Chancel (Compt rend, "rrr 751), by
treating the nitrobenzoates of ethyl and methyl with sulphydcate of ammonium, ob-
tained compound ethers, which he regards as phenyl-carbamates; but &om their
mode of formation it is more probable that they are ozybenzamates, which are iso-
meric therewith. (See Oxtbenzajoo Acm.)

Olljr.il/MfflBg, CB:«N*0 » N*.(CO)''.H".IP.— This compound is the primary
diamide of carbonic add, and has the same composition as urea, with which indeed it
is in all probability identical. It is formed in various ways :

1. By the action of ammonia on ozychloride of carbon, both being perfectly dry
(Begnault) Ann. Ch. Phys. [2] Iziz. 180; Natanion, Ann. Ch.Pharm. xcviiL 287) :

COa« 4- 4NH» = CH<N«0 + 2NH*CL

The mixture of carbamide and sal-ammoniac thus produced is soluble in water and in
aqueous alcohol ; and on adding excess of baryta-water to the solution, evaporating in
vacuo, exhausting the residue with absolute alcohol, evi^rating to dryness, dissolving:
in a small quantity of water, treating the solution with nitric add, and decompodng
the resulting nitrate of carbamide with carbonate of barium, the carbamide is obtained
in the separate state (Natanson). — 2. By the action of ammonia on carbonate of
ethvL When the two substances are bested together in a sealed tube to 180^ C,
carbamate of ethyl is first formed (at 100^), and afterwards converted by the excess
of ammonia into carbamide :

(CO)''(C«H»)»0«-f. NH« « C»H».H.O + ^^gP^lo.

^^g?)"! 0 + NH» - C«H».H.O -I- ^COy.W,

3. By the action of heat on the iBomeric compound, cyanate of ammonium, NH^CNO,
or even when a solution of that salt is left to evaporate spontaneously, also when
cyanate of potassium is mixed with sulphate of ammonium, tne mixture left to evapo-
rate, and the residue exhausted with alcohoL — 4. By decomposing ammonio-cupric
falminate with sulphydiic acid (see Fxtlxinic Acid).— ^. In the decomposition of ox-
amide {q. V.) at a red heat. — 6. By the oxidation of uric add.

The product obtained by the last four processes is urea ; the same substance occnn
as an animal excretion in the urine, in which indeed it was first discovered, being
produced by the oxidation of the nitrogenous tissues. Whether the carbamide pro-
duced by the action of ammonia on carbonic ether or on oxychloride of carbon is
identical with this, or only isomeric, is a point perhaps not absolutely dedded. Never-
theless it agrees with urea in its most essential characters, vis. in forming a sparingly
soluble crystalline salt with nitric add, and in being resolved by the action of the
stronger adds into ammonia and carbonic anhydride, as represented by the equation :

CH*N»0 + H«0 = 2NH» ■»• C0«.

CARBAMIDE. 753

It is trae that Begnavlt did not obtain a oystalline salt by adding nitric acid to the
mixture of carbamide and sal-ammoniac produced by the first process ; perhaps in con-
sequence of the presence oC the sal-ammoniac. Natanson, howeyer, did obtain a crys-
talline nitrate in the manner above described. No decided difl^irence has, indeed, been
pointed out between carbamide and urea. We shall, however, refer to the article
XJbsa for the preparation and properties of the substance usually so called, and ^all
here describe a number of substitution-products, commonly called compound ureas,

8ubstiiuHon'^>roduet8 of Carbamide : Compound Ureas,

The l^drogen in carbamide may be more or less replaced by organic radicles, acid or
basic. The compounds containing 1 at of an alcohol-radide, are obtained chiefly by the
action of ammonia on the cyanates of those radicles, just ss carbamide or urea itself is
produced by the action of ammonia on cyanic acid (cyanate of hydrogen.)

HCNO + NH» - CH*NH).
Cvanle Carbunlde.

Acid.

C«H».CNO + NH« - CH»(C«H*)N«0.

Cjanate of Btliyl-carbainlde.

Ethyl.

Those which contain 2 at. of an alcohol-radide are produced in like manner by the
action of an amine-base on the cyanate of an alcohol-radicle, e,g. ethyl-allylcarbamide,
by the action of ethylamine on cyanate ofaUyl. All these carbamides containing basic
radicles formciystaUine-salts with nitric acid, and are resolved bv the action of sulphuric
or hydrochloric acid, or of alkalis, into carbonic anhydride and an amine base, just as
carbamide is resolved under similar circumstances into carbonic anhydride and ammonia.

The carbamides containing acid radicles are produced by the action of the chlorides
of those radicles on urea. They do not form salts with nitric acid. When heated they
are resolved into cyanuric add and the corresponding acid amide {vids ii^fra),

a. CarbamidesoT Ureas containing Acid radicles, (Zinin, Ann, Ch. Phaim.
xcii 403. — Moldenhauer, ibid. zdv. 100.)

( (CO)"
AoBTTL-OABBAKXDS. C*H«N'0'-N*jC«H>0. Ciystallises from boiling alcohol

in long silky needles, and from boiling water, in stars or tufts of rhomboi'dal prisms
Dissolves in 100 pts. of cold and 10 pts. of boUinff alcohol; much more soluble in
water, insoluble in ether. At 160^ 0. it yields a uight woolly sublimate ; mdts at
200^ (Zinin), at 112^ C^Ioldenhauer), and at a higher temperature is resolved into
cyanuiic add and aoetamide :

8C«H«N»0« - C^»N*0» + 8(N.H".C«H"0).

It is not predpitated by nitric add or by mercuric nitrate.

Bbkzotl-cabbamipb. C"H»N«0> « N«.(CO)''.C'H»O.H«.— Obtained by heating
powdered urea with chloride of benzoyl to 150^ — 166^ C. Am soon as all the urea Lb
mdted upon the chloride, the mixture must be removed from the bath and briskly
stirred, whereupon it becomes pasty. The product washed with cold alcohol yields
benzoyl-carbamide as a ciystauine powder. It crystallises from boiling alcohol in
thin elongated rectangular laminae, often united in eroups. It is much less soluble in
water and in ether than in cold alcohol ; strong bomng nydrochloric acid dissolves it
better than pure water. Heated on platinum-foU it melts, emitting the odour of

Sranide of phenyl (benzonitrile), afterwards that of cyanic acid, and finally volatilises
together. Heated to 200^ C. in a tube, it mdts to a colourless liquid, which at a
higher temperature, is resolved into cyanuric add and benzamide. Ammonia has no
action on benzol-carbamide. Potash dissolves it readily, And adds separate it from
the solution. The alkaline solution, when boUedf gives off ammoniai and forms carbo-
nate and benzoate of the alkali-metaL

BuTYBTiHJABBAMiDB,C*H**N«0«»N«.(C0)*.C<H»0.H*.—Crjr5tallise8 readily from
water in small scales, from alcohol in thin elongated rhombic laminA. It is tastdess
and inodorous. Mdts at 176^ C. to a yellowish liquid which solidifies in a crystalline
mass on cooling. A high temperature decomposes it like aoetyl-urea. It aqueous
solution is not predpitated by nitric acid, oxalic add, or mercuric nitrate.

Valbbtl-oarbaxidb, C«H>«N«0« - N»(C0)''.C»H»0,H», crystallises from boilinjg
water in small nacreous crystals, tmctuous to the touch ; from alcohol in needles. It is
nearly insoluble in cold water, melts at 91^0. and when carefrUly heated yidds a sub-
limate of large iridescent scales.

Vol. L 8 0

754 CARBAMIDE.

fi. Carhamides or Ureas containing Baaylout radicles:

Alltl-cabbamids, C*H«N«0 « N«.(CO)".C^*^«. (CahonrtaadHofmaiiB,
Phil. Trans. 1856, p. 656.) — Obtained by the action of ammonia on cyaaate of allyl,
(CH\GNO + NH> » C<H"N O.) Gnrstallifles easOy by evaporation both from mter
and fiK>m alcohol. Its oomposition is that of thioeinamine in which the snl^iir is re-
placed by oxygen.

Alltl-suuvocakbaxidb, in.(GS)''.G'H*.H', also called thios insmin e, is prodnoed
by the action of ammonia on oil of mnstard. Ethyl-, phenyl-, and naphthTl-daiYatiTes
of it are produced by treating oil of mustard with ethylamine^ phenylamine and naph-
tbylamine.

DiALLTi-OABBAMnn. SinapoHne, CTBP^NK) » N*.(CO)*.(0^*)*.H«.-- Produced:

1. By the action of oxide of lead and water on snlpho^aaate of allyl (oil of mnstard) :

2(OB».CNS) + 8Pb«0 + H»0 - CH»«N«0 + Pb«(X)» + 2PMS.

2. By heating ^anate of allyl with water or with aqneons potash :

2(C»H» CKO) + BPO - CrB«NK) + C0«.

If potash is nsed, care must be taken that the action does not go too far; otherwise
nothing but amine-bases will be formed (Cahonrs and Hofmann. loc. cU.) For the
properties and reactions of this compound, see SimXpoldib.

Amtl-oasbaxibb. C^»*NK) » N«.(CO)-.C»H»».H». (A. Wnrts, Compt. rvqid.
xxxii. 417). — Produced by the action of ammonia on cyanate <^ amyl. It is decomposed
by potash into amylamine and carbonate of potassium. It forms a oystalline nitrate.

Bbnztl-oabbaxidb. Toluyl'Urea. 0"H'*N«0 « N«.(CO)''.CrH'.H*.— This sub-
stance, or more probably an isomer thereof, is produced by the action of snlphydrate of
ammonium on nitrotoluamide. (No ad, Phil. Mag. [4] yiL 142. (See Toluaviiul)

Etbtl-cabbamidb. OT«N«0»N».(CO)''.C«H*.H«. (Wurtx, CompL rend, xxxii.
414.) — Produced by the action of ammonia on cyanate of ethyL Dissolves readily in
wat«r and alcohol, and crystallises from alcohol in large prisms which decompose at
200^ C, with evolution of ammonia and other products. The aqueous solution is deoom-

Sosed by chlorine, forming a heavy liquid which crystallises gradually. Nitric acid
oes not form a precipitate in the aqueous solutioUi but cryst^ of mtrate of ethyl-
carbamide are obtained on evaporation.

DiBTHTL-CABBAMiDB, C»H'*NK) « N".(CO)''.((?H»)«.H«.— Produccd, Kke the aByl-
compound, by the action of water on^^anato of ethyl ; also by the action of etiiylamint^
on cyanate of ethyl : C*H».CNO + C^'N - C*H«NK). The nitrate forms very acid
deliquescent rhombic prisms containing C*H**N'O.HNO*, (Wurts.)

Ethyl-alltl-cabbamidb, C«H'«N»0 - N«.(CO)''.C«H».C^*.H«. (Cahonrs and
Hofmann, ioc. cit. ) — By the action of ethylamine on cyanide of allyL Crystallises in
beautiful prisms.

Similar compounds are formed by the action of methylamine, amylamine, and
phenylamine on cyanate of allyl.

£THTL-ALLTL-8ui.PHocARBAiaDB, N'(CS)".C*H*.C'H*.H*. Syu. of Ethtludosika-
xiNB. (See TmosiNAMiMB.)

Ethtl-amtl-cabbamidb, C*H»"N*0 « N«(CO)''.C»H>.0»H'».H«. — Action of amy-
lamine on cyanate of ethyl. (Wurtz.)

Mbthtl-cabbamidb, CHWO = N«.(CO)''.CH«.H». (Wurta» loc. cO.)— Ob-
tained by the action of ammonia on cyanate of methyl ; also by evaporating a mixture
of sulphate of methylamine and cyanate of tiotassium and extracting the residue with
alcohol. Crystallises in long transparent deliquescent prisms. The aqueous solution
is neutral to test-paper, and if somewhat concentrated yields with nitric acid a iveci-
pitate of CH*N»O.HNO».

DiMETHTL-cABBAjfn)B,C»H«N«0«N*.(COr.(CB?)«.H« (Wurta. lee, ct<.)— Isomeric
with ethyl-carbamide. Produced by the action of water, or of methykmine on cyanate
of methyl. Crystallises easily; melts at 97^ C; is permanent in the air; vola-
tilises without alteration; dissolves readily in water and alcohol; combines with
nitric acid, forming the salt CH"N»O.HNO«.

MBTHTL-BTHTi.-CABBAiin)B. C*H'«N«0 - N«.(CO)''.CH».C«H»JH».— Ven[delique«Mit
substance, obtained by the action of methylamine on i^anate of ethyL (Wnrta.)

Naphthtl-cabbakidb, C»'ff«NK)-N»(CO'').C"H'JP. (H.8chiff;Cliem.Gaa.
1857, p. 211.) — Obtained by saturating a solution of naphthylamioe in anhydrous
ether with cyanic acid oas, and recrystafiising from hot alocmcd. Flat^ shiniug, flexible
needles, nearly insoluble in water, more soluble in alcohol, easily soluble in ether: the
latter solution yields a crystalline precipitate with oxalic add. Ni^hthyl-carhemide
yields by spontaneous decomposition, a resinous substance, whose alcoholic solutieu is

CABBAMIDE. 755

oolonied violet by adds, and red again by alkalia. The same reaction has been ob-
senred to be proanced on test-paper by a tincture of madder (Sacc), andby nitroso-
naphthaUn (dhurch and Perk in, Jahresber. d. Chem. 1866, p. 609).

NAPHTHTi^ALLTZrSULPaocABBAMZDB. NXGS'^.C>*H\C*H*.9'.— Syn. of Napbthtl-
TmosiNAiaiaL (See Thiosinaminb.)

Phbnti^abbaxidb, C*H«N*0 - N*.(CO)^<>H*.H». Phmyl-urea, Aniiine-urea,
CarbanUamide, Carbamide'Carbamlide, (A. W. Hofmann, Ann. Ch. Pharm. liii. 67 ;
Ivii 266 ; Izz. 130 ; Izxiv. 14 ; Gm. zi 603.) — This compound is obtained : 1. By
passing cranio add yapour into anhydrous phenylamine, kep>t as cool as possible ; dis-
solring the resulting ciystalHne mass in hot water; filtering to separate diphenyl-
carbamide (which is produced more abundantly in proportion as the phenylamine has
been more heated) ; and oooUng the filtrate to the crystallising point — 2. By
treating sulphate or hydrochlorate of phenylamine with aqueous cyanate of potassium,
and separatmff the resulting phenyl-carbamide (cyanate of phenylamine) by diges-
tion in aloohoT. — 3. By mixmg phenylamine with an aqueous solution of chloride of
cyanogen (obtained by passing cnlorine eas through aqueous hydrocyanic add), puri-
fying the resnltinff oystals with animal charcoal, and recrystsiUising from hot water.
— 4. Oranate of phenyl mixed with ammonia, immediatenr solidifies in the form of
phenyl-carbamide, OT*.CNO + NH« - CH'NH).

Phenyl-carbamide forms fusible needles and laminse, sparingly soluble in cold, easily
in boiling VHUer^ easily also in alcohol and ether. It dissolves in nUric acid, but scarcely
to a greater amount than in water, and oystallises therefrom unaltered, differing in
this respect from carbamide. It dissolves also without alteration in cold sulphuric
acid, but when heated therewith, it is resolved into carbonic anhydride,, phenyl-sulph-
amic add, and add sulphate of ammonium :

C'H'NH) + 2H«80^ - C0« + N.H.Cra».(SO»)'')^ ^ NH«.H.SO«.

Heated above its melting-point, it is resolved into ammonia, dlphenyl-carbamide, and
cyanurie add :

6[N«.(00)".C^».H1 - 8NH« + 8[N«.(C0)''.(C*H»)«.H«] + N».H».(C!b)«
Phenyl-carbamidflL DipbenyUcartMinide. Cyanurie add.

By boiling with strong potaaMey^ or more quickly by fudon with hydraU ^potauiujn^
it yidds ammonia, phenylamine, and carbonate of potassium :

CH'NK) + 2KH0 - NH» + C«H'N + K«CO».

It is not decomposed by boiling with dilute adds or alkalis.

The name phenyl-urea has hitherto been generally applied to the isomeric compound,
which Chancel obtained by the action of sulphydrate of ammonium on nitrobenzamide
(Gerh. Trait^ i 427). This compound is a powerful base ; but it does not agree with
the ureas, either in iti9 mode of fonnation, or in its reaction with alkalis. It should
rather be regarded as oxybefuodiamide (q. v.) the primary diamide of oa^ybenzoic acid
(CH*0'). Its formation may be represented by tne equation :

NltrobaniaaBide. Oxybeoso-

diamide.

When treated with potash, it yidds ammonia, and an add which is probably oirben-
■oic acid. The reaction consists of two stages, ammonia and ozybenaamie add being
formed in the first, ammonia and oxybenzoic add in the second :

jpj((?H^;- ^ HH) - NH« + K.H«.(C^'Orjo

Ozybenso- Oxybensamic

diamide. add.

N^MCH-^-jO + HK) - NH" + ^'H^.Jo'

Ozybeniamie OxybensolG

add. add.*

The true phenyl-urea is the compound above described asphenyl-carbamide.

BTHTL-PHBNti^oARBAicDE, C»H"N«0 - N•.(CO)^(?H^C^^H^ is obtained by dis-
solving phenvlamine in cyanate of ethyL Great heat is evolved, and the mixture
on cooling solidifies to a crystalline mass. It is slowly decomposed by potash, yield-
ing phenylamine, ethyhunine, and carbonic anhydride. (Wurtz, CJompt rend, xxxii.
417.)

• Sm a Dspar tqr Dr. Hofmann (Proc. Roy- Soc s. GOS), where bow«T«r the add rormed U Mid to
be not osybeoioic, bat bensolcadd.

8o 2

756 CARBAMIDE.

NrrAOFKBHTL-CAKBAxmB, C'H»NK)« = N«.(CO)''.C^*(NO«).H*. — Ppodnccd, toge-
ther with dinitromelaniline, by the action of gaseous chloride of cyanogen on nitro-
phenyUmine dissolved in ether. (Hofmann, Ann. Ch. Phann. IxviL 166 ; Ixx. 137.)

DiFMJtw ¥ I r-oAimit^iiTt>«- DiphenyUurea^ Carbanilide, Carbophenylamide, C^S}^S*0 »
W.{COy.(C^W)\lB* (^Hofmann, Ann. Ch. Pharm. Ivii 266; Gm. xi. S49).— Pio-
daced : 1. By the action of cyanate of phenyl on phenylamine, or on water :

2[N.(C0r.<>H»] + HK) -= C0« + N».(COf .(C^»)«.H».

2. By the action of phenylamine on ozychloride of carbon. — 3. In the deoompontion
of diphenyl-Bolphocarbamide by potash. — 4. By the dry distillation of phenyl-car-
bamide, melanozimide, or oxahite of meUniline. (See those compounds.)

Diphenyl-carbamide forms white silky needles, which melt at 205^ C. and distil
without decomposition. It is odourless at ordinary temperatures, but has a snfTocating
odour when heated. It dissolves sparingly in toater, abundantly in alcohol and ether.

When quickly heated in the moist state, it yields carbonate of phenylamine, together
with other products. With strong sulphuric acid, it gives off carbonic anhydride, and
forms water and phenykulphamie add:

N«j (eS*)« -I- 2(^,' |o«\ « {coy.o + hk) + 2/^-^-^(^*)''|o.)

By boiling with potash, it is resolved into phenylamine and carbonate of potassium.

Diphenyl-carlMmide is isomeric with jlavine, an organic base produced l^ the action
of reducing agents on dinitrobenzophenone. This base is indeed sometimes regarded
as diphenyl-urea (Qerh. i. 430); but it does not exhibit the characters of a urea.
(See FuLvniB.)

Phbntlsulphocabbjlmzdb, (?HWS-N«(CS)".(>H».H". (Hof mann,Proceed-
ings of the Boyal Society, ix. 276.) — Produced by the action of alcoholic ammonia on sul-
phocyanate of phenyl :

C«H».CN8 + NH« - CH«ITO.

The mixture, on being ^ntly warmed, quickly solidifies into a eiystalline compound,
which may be obtained in b^utiful neecues by oystallisation from boiling water.

Phenylsolphocarbamide is a weak base, and forms a chloroplatinate containing
CH"N*S.HCLPtCl*. It also combines with nitrate of silver. By boiling with nitrate
of silver, it is converted into phenyl-carbamide.

PHENTi/-ALLTL-suLPHocABiBAHiDB. K'.(CS)''.CH*.C^*.H'. — Syu. with PmnTiw-
THiosmAMUiB. (See THiosnvAiiiifB.)

DiPHBNYL-suLPHOCA RBAMTDB. Sulphocorhamlide, Sulphophenyl-vrea. C'ID'N'S *
N«(CS)".(C«H»)*.H«. (Hof mann, Ann. Ch. Pharm. IviL 266 ; btx. 144 ; Gm. xl 350.
Further, Proc Roy. Soc.x. 274.— Laurent and Delbos, J. Pharm. Ys] x. 309. —
Laurent and Gerhard t, Ann. Ch.Phys. [3] xxii. 103 ; xxiv. 196.)— This compound
is obtained: 1. By the action of sulphide ca carbon on phenylamine, the action being
accelerated by addition of alcohol (Hof mann):

2C^'N + CS« = C"H»«N^ + H«S.

— 2. By heating a mixture of phenylamine, sulphocyanate of potassiuni, and solphuiic
acid, the diphenyl-sulphocarbamide then distilling over, while sulphate of ammonium
remains behind (Laurent and Gerhardt). — 3. JBy mixing phenylamine with sulpho-
cyanate of ohenyl: C*H».CNS + C«H'N « C"H>*NS. (Hof mann.)

Diphenyl-Bulphocarbamide sepatetes from the mixture of phenylamine and sulphide
of carbon, in eiystalline scales or rhombic tables ; from alconol, m brilliant iridescent
laminse. It dissolves sparingly in water, easily in aloohoL It has a peculiar odour,
especially when heated, and a bitter taste exceeding in intensity that of any other
known substance. It melts at 140^ C, and distils without decomposition. Heated
with strong sulphuric acid, it forms phenyl-sulphamic add, giving off carbonic anhydride
and sulphydric add (Hof mann):

C"H»«N«8 + 2H*S0* - C0« + H«8 + 2(N-^^*(SOTlO \

Bj phosphoric anhydride, chloride of ginc, or hydrochloric acid ^as, it is lesolred
into phenylamine and sulphocyanate of phenyl (Hof mann). Fused with potash, it
yields phenylamine, together with sulphydrate and carbonate of potassium :

C'«H'*N«S + 3B:H0 - 2C«H'N + K«CO» + KHS.

When boiled with alcoholic potash, it is converted into diphenyl-carbamide :

C«*H'«N»8 + K«0 = K«S + C"H»N*0.

CABANTL— CARBON. 757

Similarly when ita alcoholic Boliition is boiled with mercurie oxide. It is not decom-
posed by dilate acids or alkalis.

Pipbhtl-Cabbamids. Piperyl'Urea.IHpendine'Urea, C^»«N«0=N*(CO)\ C»H».H»
(Cahonrs, Ann. Gh. Phys. [3] xxzviii. 76.) — Obtained by boiling sulphate of pipe-
ridine with cyanate of potassium, evaporating to dryness, and exhausting with strong
alcohol. It appears also to be formed when Tapour of cyanic acid or moist chloride of
cyanogen is passed into piperidLne. The alcoholic solution yields it, by spontaneous
evaporation, in long white needles.

Metkjd^peryl-carbaimde, C*H"(GH')N*0, and MhyUfiperyl-carhamide^
C%"((?H*)NH), are produced by the action of piperidine on the cyanates of methyl
and ethyL

OAMMAJKU^ Syn. of Ctanatb of Phbnti.. (See OrAiao Ethbbs.)

CAMBAMTUHMm Syn. of Dxphbntl-ca bbawtdb (p. 766).

OAXBAMHiZO JLOTDm Syn. of PHBMTi.-flA rbamio Acid (p. 761).

CAxaAanunrsAWB and c a bw a w imxgTXAir b» Phentlgab-

BAMATB8 OF Ethtl and Mbthtl (p. 762).

CABBAXOrmi The name given b^ Thau low (J. pr. Chem. zxzi. 220) to the
ffas evolved by ignition of cyanide of silver, which he regards as isomeric but not
identical with cyanogen. It has a peculiar odour, and strongly irritates the eyes and
respiratoiy organs. Specific gravitv 1*73. Liquefies at — 4^'C. Eums with red
flame. It dissolves in potash, and the solution when neutralised with nitric acid does
not precipitate iron-salts. (Thaulow.)

»TXO AOXB. Syn. with PiCBic AczD.

U or Carburets. Compounds of carbon with metals. These com-
pounds have not been much studied : none of them occur as natural minerals, and it
is difficult to obtain them in definite form. The usual effect of the union of carbon
with a metal, is to render it hard and brittle. (See the several metals.)

Syn. with Bbnzonb.
^ZC AOZB. See Cinnaicbin (p. 981).

See Htdbooabbons.
kO&XC AOZB* Syn. with Phbmic Aged.

CABBOV. Symbol C. Atomic weight 12. — Carbon is one of the most abundant
of the elements, existing both in the free state and in an endless variety of combina-
tions. It is found pure in the diamond ; nearly pure in graphite or plumbago, less
pure as anthracite. It occurs also abundantly in the form of carbonates, especially
carbonate of calcium, and is an essential constituent of organic bodies, from which
it may be separated in the form of charcoal, by <liaHlling off the more volatile elements,
hydrogen, oxygen, nitrogen, &c.

Carbon in the free state is a solid body, destitute of taste and odour, infyisible and
non- volatile, excepting at the temperature produced by a powerful electric current The
several modifications exhibit great diversities of colour, lustre, transparency, hardness,
density, and power of conducting heat and electricity. It exhibits ciystalline forms
belonging to two different systems, the regular and the hexagonal, and several amor^
phous modifications.

1. Diamond, This valuable gem consists of pure or nearly pure carbon. It is
found in alluvial soils produced by the disintegration of ancient rocks, the principal
localities being in Inoia, Borneo, Brazil, and the Urals. Diamonds occur thinly
scattered through large quantities of soil, and veiy careful washing and examination
are required to separate them.

The diamond crystallises in forms belonging to the regular system, namely, the oc-
tahedron, which is usually the predominating form, though it rarely occurs alone ; also
the cube, the rhombo'idal dodeofthedron, whidi is very frequent ; the triakis-octahedron,
a figure of 24 faces, formed by the superposition of a low triangular pyramid on
each face of the octahedron ; and the hexakis-octahedron, a 48-sided figure formed
in like manner, by a 6-faced acumination of the octahedron. Intermediate forms are
also of frequent occurrence, the secondary faces being sometimes so numerous as to
give the czystal the appearance of having convex &ces. Sometimes the faces are really
curved, and consequently intersect in curved edges : the dodecahedron and octahedron
frequently occur with convex faces. Hemihednd forms and twin-crystals are also found.
(For figures, see the article Cbtstalloobafht.)

All diamonds cleave easily in directions parallel to other faces of the regular octi^
hedron, which is therefore the primary form. The firactnre is conohoidal. The

3o 3

768 CARBON.

specific gravity of the diamond is 3-6295 aooording to Thomson ; 3*66 according to
Pelouze. It is the hardest snbstance known, being capable of scntching all othen.
Diamonds with curved edges are also capable of cutting glass, and are much used
for that purpose, the curred edges penetrating the glass like a wedge ; those with straight
edges merely scratch.

The purest diamonds are colourless and transparent ; but many exhibit Tsrious shades
of yellow, red, green, brown, and blade ; these coloured diamonds leave, when burnt,
firom 0'65 to 0*2 per cent, of ash : colourless diamonds leave but a trace. The diamond
has a strong lustre (called adajnaniine), and high refractive and dii^Mxsive power :
hence its peculiar brilliancy. The lustre of the natural diamond is greatly incresflcd
by cutting it in a peculiar manner, so as to give it numerous facets capable of reflecting
and dispersing lignt in various directions. This is effected by pressing the diamond
against a revolving metal disc covered with a mixture of diamond dust and oil, no
oUier substance being hard enough to abrade the diamond. The dost for this pnrpoee
is obtained either by collecting that which faUs away in the process of euttmg and
polishing, or by pounding up diamonds which have not sufficient transparency to be
valuable as gems. Diamonds are sometimes found in opaque S[^eroidal lumps, desti-
tute of crystalline structure and transparency, and useless excepting in the farm of
powder.

The diamond conducts electricity but slowly. Like all other forms of carbon, it
neither melts nor volatilises at the heat of the most powerful furnace; but when placed
between the charcoal cones of a powerful voltaic battery, it becomes white-hot, swells
up, splits into fragments, and after cooling, presents the aspect of coke prepared from
bituminous coaL When very strongly heated in the air or in oxygen gas, it takes fire
and bums completely away, forming carbonic anhydride. This fact of the oomlmsti-
bility of the diamond, which had been conjectured by Newton from its great refracting
power, was first demonstrated in 1694, by the Florentine academicians, who succeeded
in burning it in the focus of a concave mirror. Lavoisier and Guyton-Morveau, and
afterwards Davy, showed that the sole product of tlie combustion in oxygen is CBrbonic
anhydride, and therefore that the diamond is pure carbon.

2. Graphite. — This name is applied to several varieties of native carbon containing
from 95 to nearly 100 per cent, of that element, some cxystalline, othen amorphous,
but all perfectly opa(^ue, having an iron-black or steel-grey colour, and metallic lustre,
producing a black shming streak on paper ; sectile ; of specific gravity 1*209, hardness
between 1 and 2, and conducting electricity nearly as well as the metals. Graphite
was formerly regarded as a carbide of iron, but the iron is now known to be merely in
a state of mixture, as also small quantities of silica and alumina.

a. Crystallised or Foliated GrapMte.—Tbia variety is found occasionally in small
six-sided tables belonging to the hexagonal system, cleaving perfectly in the direction
of the base, and having the basal planes striated parallel to the alternate sides. More
commonly, however, it occurs in fdiiated or granular masses. It is found imbedded in
quarts near Travancore in Ceylon, and near Moreton Bay in Australia ; with olivine
and sphene at Ticonderoga in the State of New York, and in gneiss at Stourbridge,
Massachussets, where it presents a structure between scaly and fine granular, and an
occasional approximation to distinct orstallisations (Dana, ii. 27). It is also obtained
artificially by melting cast-iron contaming a large proportion of carbon and leaving it
to cool slowly. It is tough and difficult to pulverise by mechanical means, but it may
be reduced to the state of veir thin lamin» by prolonged trituration with water.

/B. Amorphous Graphite. — ^ThiB variety, also called plumbago or black lead, is found
in Borrowdale, Cumberland, where it occurs in nests of trap in the day-slate, and is
largely imported into this country from Germany, principally from Griesbach near
Passau. The Borrowdale mine was formerly very rich, but now appears to be nearly
exhausted (see Ur^s Dictionary of Arts, Manufactures and Mines, iii. 467). Amor-
phous graphite is softer than the crystalline variety, and makes a much blacker streak
on paper : it is tiierefore better w&pted for the maldng of pencils. Some kinds of
amorphous graphite, occurring in the coal measures, have very much the appearance
of anthracite : such is the case with the graphite of New Bninswick.

Graphite resembles the otiier modifications <^ carbon in being unalterable when
heated in close vessels, excepting at the temperature of the electric current, and in yield-
ing carbonic anhydride when burnt in contact with oxygen. But it difi^ essentially
from all other forms of carbon when subjected to the action of certain oxidising agents,
such as a mixture of chlorate or acid chromate of potassium with sulphuric or nitric
acid, or a mixture of nitric and sulphuric adds. In this case Brodie has shown (Ann.
Ch. Phys. [3] xlvi. 351 ; further, PhiL Trans. 1860, i ; Ann. Ch. Pharm. cxiv. 7) that
it is converted into a peculiar add, called graphitic aeid, which is best obtained hj
heating pulverised graphite with chlorate of potassium and nitric add, as long as
yellow vapouTB are given ofl( then washing it with a large quantity of water, drying it

CARBON. 759

on the water-bath, and repeatang this series of qperatioDS seTOnil times. In this manner
the graphite is ultimately oonyerted into thin transparent crystals of graphitic acid,
C"H*0\ Brodie, however, regards this acid as analogoas in composition to the acid
Si^HH)*, which Wohler obtained by the action of oxidising agents on graphitoidal silicon ;
and accordingly he supposes that the atomic weight of graphite is different from that
of the other forms of ^carbon, and equal to 33, which he denotee by the symbol 6r
(graphon) ; subsdtatilig this value in the preceding formuki of graphitic acid, it be-
comes Or'H^O*. (See Atoioo Wbioet of Cabbon. p. 767 ; «i^so Giulphitic Acid.)

Graphite cannot be converted into graphitic acid by a single treatment with oxidis-
ing a^nts, however long continued; but by subjecting it to this treatment for a cer-
tain tune, then washing it with water and igniting, it may be purified and obtained in
a stete of veiy minute division. A good way of proceeding is to mix coarsely
pounded graphite with ^ of its weight of chlorate of potassium, add the mixture to a
quanti^ of strong sulphuric acid equal to twice the weight of the graphite, heat the
whole in the water-bath as long as yellow vapours of chloric oxide are evolved, wash
the cooled mass with water, then diy and ignite it ; it then swells up and leaves finely
divided graphite. If the graphite to be purified contains siUceous matters, a little
fluoride of sodium should be added to the mixture before heating.

Graphite is used for making pencils, for polishing stoves, and other articles, for
diminishing the friction of machinery, for making crucibles, and in the electrotype
process for coating the surfaces of wood and other non-conducting materials, so as to
render them conductive.

3. Antkraeite or stoTU-ooal is an amorphous variety of carbon containing about 90
per cent, of that element associated with hydrogen, oxygen, nitrogen, and ash.. It is
intermediate in composition and properties between graphite and bituminous coal,
bein^ blacker than graphite, and having a higher lustre than ordinary ooaL Specific
ffravity 1*3 to 1*7. Hardness « 2 to 2*1. It bums with difficulty, requiring a strong
draught to keep it in a stete of active combustion : hence it is fit only for burning in
dose stoves and furnaces ; it does not cake together like bituminous ooaL Anthrtweite
occurs abundantly in South Wales, in the departments of Mayenne and Is^ in
France ; also in Pennsylvania and Bhode Island.

4. Carbon obtained from Organic Substances by Dry Distillation or
Imperfect Combustion, — ^When animal or vegeteble substences are strongly heated
in dose vessels, the more volatile dements, viz. the oxygen, hydrogen, and nitrogen,
with part of the carbon, are driven off in the form of gaseous products, some of which
afterwards condense in the liquid form, while a considerable portion of the carbon re-
mains behind in the form of a black mass, called charcoal, of greater or less compactness,
according to the nature of the original substance. If the sulwtance thus treated — wood
or coal, for example — contains any inorganic materials, such as potash, soda, lime, &c,
these remain behind with the charcoal. The purest kind of charcoal is that obtoined
by heating sugar, sterch, or some other organic substance, free from inoiganic dements,
in a dose vessel. There then remains a black, brilliant, porous charcoal, which is
nearly pure carbon, but contains a small quantity of hydrogen and oxygen, which cannot
be driven off even by the most intense and long-continued heat

a. Wood-Charcoal. — Wood oonsisto of carbon, hydrogen, and oxygen, the two latter
being in the proportion to form water. When heated in the open air, it bums com-
pletely awajr, with the exception of a small quantity of white ash ; but if the supply
of air is limited, only the more volatile ingredients bum away, and the greater part of
ther carbon remains behind. This is the prindple of the process of charcoal-burning
as it is practised in countries where wood is abundant^ on the Hars mountains in
Germany, for instance. A number of billets of wood are built up vertically in two or
three rows into a large conical heap, which is covered over with turf or moistened
charcoal-ash, holes being left at the bottom for the air to get in. A hollow space is
also left in tiie middle of the heap, to serve as a fiue for the gaseous matters which
are evolved. The heap is set on fire by throwing burning pieces of wood into the
central opening, near the top of which, however, a kind of grate, made of billets of
wood, is placed, to prevent the burning fuel from falling at once to the bottom. The
combustion then proceeds gradually from the top to the bottom, and from the centre
to the outside of the heap ; and as the central portions burn away, fresh wood is con-
tinually thrown in at the top, so as to keep the heap quite full. The appearance of
the smoke shows how the combustion is proceeding ; when it is going on properly, the
smoke is thick and white ; if it becomes thin, and especiaUy if a blue fiame appears,
it is a sign- that the wood is burning away too fast, and the combustion must then be
cheeked by partially stopping up the holes at the bottom, or by heaping fresh ashes on
the top and sides, and pressing them down well so as to diminish the draught As
soon as the combustion is completed, the heap is completely covered with turf or ashes,
and left to cool for two or three days. It is then teken to pieces, and the portions

So 4

7(>0 CARBON.

sdll hot we cooled by throwing water or sand upon them. The quantity of chaicoal
thus obt4imed varies with the manner in which the eombnstion is conducted. 100 parta
of wood yi^d on the average from 61 to 66 parts by measure, or 24 parts by weight
of charcoal When the borning is very carefully conducted, the quantity may amount
to 70 per cent, bv measure.

In England a large quantity of charcoal is obtained in the dry distillatioD of wood
for the preparation of acetic acid. For this purpose the wood is heated to redness in
caj»t'iron cylinders, whereupon a number of volatile products are given cff, indnding «
large quantity of tany matter, an inflammable spirit oilled wood-spirit or wood-naphtha,
and acetic acid ; and in the retorts there remains a quantity of charcoaL

For the manufacture of gunpowder, charcoal is sometimes prepared by subjecting
wood in iron cylinders to the action of over-heated steam. (Violette, Ann. Cfa.
Phys. [3] xxiiL 476.)

Wood-charcoal is more or less compact, according to the kind of wood from which it
is formed. The lighter woods, such as willow, yield a very porous chareoal, having
comparatively little power of conducting heat and electricity; box-wood, on the
eontraiy, yields a very compact charcoiu, which is a good conductor of heat and
electricity, and is admirably adapted for exhibiting the voltaic light. The density
and conducting power of chareoal are greatly increased by exposing it in dose vessels
to a very high temperature. Charcoal retains the form, and to a considerable extent
the ext^nal structure of the wood, so that a horizontal section exhibits distinctly the
concentric rings and the traces of the medullary rays. When burned it leaves from
1 to 6 per cent of ash. According to Berthier, 1000 parts of lime-wood leave 60 parts
of ash ; of oak, 26 ; birch 10 ; fir 8 ; hornbeam 26 ; beech 30.

b. Coke. — Ordinanr bituminous coal, which consists of the remains of ancient forests
and peat-mosses, and appears to have been formed from wood by a process of slow
decay going on without access of air, dijOTers from wood in containing a larger proportion
of carbon, and less oxygen and hydrogen ; it also contains nitrogen derived from the
tissue of the plants. This substance, when heated in the open air, bums away like
wood, leaving nothing but a white ash ; but, when strongly heated in cast-iron cylin-
ders, it undergoes a decomposition like that which takes place in wood under similar
circumstances, a large quantity of volatile products being given oS, viz. carboretted
hydrogen gas (the gas used for illumination) and a tany liquid containing ammonia
and a variety of other products ; while a black, dull-looiang, porous moss, called co/ce^
is left in the retorts. This substance also consists mainly of carbon, mixed, however,
with a quantity of inorganic constituents, greater than that which occurs in wood-char-
coal, so that it leaves a lar;^ amount of ash when burned. The aspect of ooke varies
greaUy according to the kmd of coal from which it is obtained. Bituminooa coals,
such as the Newcastle coal, undergo a kind of semi-frision before they decompose, and
yield a very porous coke, having a brilliant metallic aspect ; anthracite, on the oontraiy
undergoes but little alteration by heating, and yields a coke having very much of the
form and aspect of the original mass. Coke is used in the iron districts of South
Wales and Staffordshire, for reducing the metal from the ore. It is there prepared
from the coal which occurs in the same districts, by partially burning that substance
in longitudinal heaps, more or less covered up with the ashes of former fires, the object
being to produce a smothered combustion, sunilar to that already described as used for
the preparation of wood-charcoal. This process is very wasteM. unless carefully con-
ducted.

c. Metallic Carbon, Glance-coal, — ^This is a very dense form of carbon, deponted
when certain volatile organic compounds, especially hydrocarbons, are passed through
red-hot tubes of porcelain or cast-iron; it collects in the upper part of the retorts in
which carburetted hydrogen gas is distilled from coal, and is likewise produced in
blast furnaces. It often exhibits the lustre and sonority of a metal, is very hard, a
good conductor of heat and electricity, and bums with difficulty. It is used to form
the negative element in Bunsen's voltaic battery.

A very hard and compact carbon, also used for the purpose just mentioned, is ob-
tained by heating to redness, in an iron mould, an intimate and impalpable mixture
of 2 pts. coke and 1 pt bituminous coal, then several times steeping it in treacle, and
subjecting it again to a very intense heat. The mass thus formed is very hard, may be
sawn and filed without breaking, and conducts electricity like a metaL

d. Lamp-black, — ^Most of our ordinary combustibles, consisting of carbon and hy-
drogen, such as tallow, wax, and oil, undergo but imperfect combustion, unless assisted
by an artificial draught of air. The consequence is, that a portion of the carbon,
which is the less combustible element of the two, remains unburned, and is driven off
in smoke, or deposited on cold surfaces in the form of soot or lamp-black; thus, a plate
of glass or metal held in the upper {>art of a candle flame is quickly covered with a
black deposit of carbon. Lamp-black is ordinarily prepared by the imperfect combos-

CARBON. 761

tion of highly carbonised bodies, such as rarin or pitch. The apparatus consists of a
cylindrical stone chamber, in which is suspended a cone of iron plate, hayins a hole at
top, and capable of moviug up and down ; this cone serves for a chimney during the
operation. A cast-iron pot, containing the resin or pitch, is heated in a furnace out-
side the chamber ; the yapours proceeding from it are set on fire ; and the supply of
air is properly regulated by apertures which may be opened and closed at pleasure.
The impeifect combustion of the vapour produces a considerable quantity of lamp-
black, which collects on the cone and on the walls. When the operation is finished, the
cone is lowered, and as it is made to fit the chamber exactly, it scrapes the wall as it
descends, and causes the deposit to &U down on the floor. Lamp-bliuik thus obtained
is always contaminated with oily matter ; it may be purified by calcination in a covered
crucible. Sometimes the chamoer is hung with coarse cloths, on which the soot col-
lects ; they are withdrawn from time to time and scraped.

A better method of condensation is to cause the smoke and vapour to pass through
an inclined iron tube, in which the oily products collect, and thence into a series of con-
densing chambers ; the purest product is then found in the farthest chamber. The
finest kind of lamp-black is obtained by burning oil or fat in lamps, and causing the
products of combustion to pass through a series of iron cylinders, terminating in a
chimney ; the cylinders are opened at bottom from time to time, and the carbonaceous
deposit removed. As obtained by either of these methods it is always more or less
contaminated with oily matter. It may be purified by calcination in a covered crucible,
but for the purposes to which it is chiefiy applied, viz. for painting and for the manufac-
ture of printing ink, the presence of the oil is not objectionable.

e. Animal Charcoal or Bcne-hlack^ is a mixture of very finely divided charcoal and
phosphate of calcium obtained by calcining bones in dose vessels. Its preparation and
properties have been already described (p. 624).

Absorbent power of ChareoaL^-Wood-chiacoal and other porous forms of carbon
have the property of absorbing large quantities of gases : the greater the porosity of the
charcoal the greater is also its absorbing power. In its ordinary state, however, charcoal
has its pores filled with atmospheric air, and to enable it to exert its full absorbing power
on any other gas, it must first< be freed from the air contained in it by heating it to red-
ness and cooling it under mercury. Saussure has shown that recently ignited box-
wood charcoal absorbs at 12^ C. and under a pressure of 724 millimetres, the follow-
ing quantities of different gases :

Ammonia . . .90 vols. Ethylene . . 35 vols.

Hydrochloric acid

Sulphurous anhydride

Sulphydric acid .

Nitrous oxide

Carbonic anhydride .

Charcoal also absorbs moisture with avidity from the air, as well as other conden-
sable vapours, such as odoriferous efiluvia. Hence freshly calcined charcoal, wrapped
up in clothes which have acquired a disagreeable colour, destroys that odour. It has a
considerable effect in retarding the putrefaction of animal matter with which it is
placed in contact. Water is found to remain sweet, and wine to be improved in quality,
if kept in casks the inside of which has been (harred. In the state of coarse powder,
wood-charcoal is particularly applicable as a filter for spirits, which it deprives of the
essential oil they contain. (Graham's Elements of ChemisPry, 2nd ed. voL i. p. 338.)
Water contaminated with offensive gas and other matters may also be rendered fit
for drinking by filtering it through coarsely pounded charcoal interposed between two
layers of sand.

Charcoal not only absorbs gases, but frequently also determines their combination.
If a piece of charcoal, which has remained for some time in an atmosphere of sulphu-
retted hydroffen, and has absorbed a considerable quantity of that gas, be introduced
into a vessel filled with oxygen, combination immediately takes place between the
oxygen and the elements of the sulphuretted hydrogen, water and sulphurous acid
being formed, and a portion of the sulphur separated. The charcoal always becomes
very hot, and sometimes the heat is great enough to produce explosion. Similar phe-
nomena are exhibited by other combustible gases.

This property of charcoal has been applied by Dr. Stenhouse to the construction of
ventilators and respirators for purifying infected atmospheres. In a pamphlet, bearing
the title ** On Charcoal as a Disinfectant," Dr. Stenhouse observes : — " Charcoal not
only absorbs effluvia and gaseous bodies, but, especially, when in contact with atmo-
spheric air, rapidly oxidises and destroys many of the easily alterable ones, by resolving
them into the simplest combinations they are capable of forming, which are chiefly
water and carbonic add. ... £ffluvia and miasmata are generally regarded as

90 vols.

Ethylene
Carbonic oxide

. 35

85 ..

. 9-42

65 „

Oxygen .

. 9-26

55 „

Nitrogen* *

. 6-50

40 „

Hydrogen

. 1-25

35 ..

764 CARBON : CHLORIDES OF.

bination to another: e.g, ethyl, C*H*, amvl, C*H", aUt/l, C"H*, ethylene, (?S\ amy^
lene, C^H**, &c. The hydrogen in these hydrocarbons, may be more or less replaced
by chlorine, bromine, nitryl (NO*), and other elements or groups, whereby deriTatiTe
radicles are formed, also capable of entering into combination, replacing hydrogen, &c.
like simple radicles, e, g, brofnethyl, C^K*&, ehiorethylent, CH'Cl, dinUronaphthaUne^
C'*H*(NO*)*, &c. Whenthehydrogeninahydrocartwn is thus completely replaced by
another element, a chloride, bromide, £cc. of carbon is produced. In this manner,
tetrachloride of carbon CC1\ is formed firom marsh-gas CH\ dichlozide of carbon,
C*C1«, from ethylene, C*H*, &c

C AXBOWf BBOMIPBS OF. Several of these compounds appear to exist, but
only one of them, the dibromide CfBr*, has been analysed.*- This body is obtained by
treating alcohol or ether with bromine, saturating the resulting hydrobromie acid
with potash, distilling, and treating the residue with water. Dibromide of carbon
then remains as a white crystalline deposit which may be purified by washing with water
(Lowig, Ann. Ch. Pharm. iii. 292). Its formation is represented by the equations :

C*H«0 + 4Br« « C*Br* + 4HBr + H«0.

Alcohol.

C«H»*0 + 8Br* « 2C*Br« + 8HBr + H*0.
Ether.

It is also produced by the action of alcoholic potash on the dibromide of tribromethy-
lene (Lennox, Chem. Soc. Qu. J. xiv. 209):

C«HBr».Br* + KHO - C*Br« + KBr + H»0.

Dibromide of carbon forms white cxystalline plates, unctuous to the touch, hsring an
ethere-al odour and saccharine taste ; it melts at 60° C., and sublimes without alteration.
It is nearly insoluble in water, yeiy soluble in alcohol and ether; not decomposed by
acids or alkalis. It bums in the flame of a spirit lamp, giving off yapours of hydro-
bromic acid, but ceases to bum as soon as it is removed from the flamei Chlorine
attacks it in the melted state, forming chloride of bromine. Heated with oxide of
mercury or passed over red-hot oxide of zinc, copper, or iron, it yields metallic bromine
and carbonic anhydride. When passed over red-hot metallic zinc, copper, or iron, it
also yields a bromide of the metal without disengagement of gas. (Lowig.)

Commercial bromine sometimes contains a liquid l»omide of carbon, which may also
be obtained by the action of bromine on ether and alcohol, especially if chlorine is like-
wise present. It is an oily, colourless, fragrant liquid of specific gravity 2*436, not
solidiflable at — 26*^ C, boiling at 120^ C., so that it is easily separated from bromine by
distillation. It is insoluble in water, not decomposed by ados or dilute alkalis, but
decomposed by fusion with hydrate of pNotassium, into bromide and carbonate of potas-
sium (Pose leer, Ann. Ch. Pharm. Ixiv. 287). The same compound wpears to be
produced by the action of 2 pts. bromine on 1 pt iodide of ethylene, CH*!', and may
be separated from bromide of iodine by means of dilate potash.

In the preparation of bromine, there is sometimes formed an oily ethereal liquid
called oil of bromine, which appears to contain C'H'Br*. When dropped on red-hot
fragments of glass, it yields a deposit of carbon, together with crystals and a dazk-brown
oil, while hy<£robromic acid and a combustible gas escape. The dark-brown oil appears
to be a portion of the liquid which has remained undecomposed and has absorbed
bromine, and the crystals consist of a bromide of carbon C^Bi^. (H. Hermann, Ann.
Ch. Pharm. xcv. 211.)

CASSOW, CBXiO&ZiraS OF. Carbon does not unite directly with chlorine :
but several compounds of these elements are obtained by the action of chlorine, aided
by light or heat, on organic bodies, chiefly on hydrocarbons or their chlorinated deri-
vatives, e. g, CCl* from marsh-gas (CH*), or chloroform (CHCl*), CQ* from ethylene
(C^H*), C»C1« from tritylene (C*H«), C'»C1« from naphthalene (C •H«X &c. It is" ens-
tomary, however, to restrict the term chloride of carbon to four of these bodies,
containing 1 and 2 atoms of carbon, while the rest are regarded as substitution-d^va-
tives of organic radicles, e. g, C *CP, as perchloronaphthalene. The names and formuls
of these four compounds are given in the following table, in the left-hand column, ac-
cording to the atomic weight of carbon [12] here adopted, in the right-hand column
according to the smaller atomic weight of carbon [6], the latter being the names by
which they are generally known :

[C - 12]

[0- 6]

Protochlorido . . C*C1«

Subchloride .

CCP

Dichloride . . . C«a«

Protochloride .

ccr*

Trichloride. . . C-Ci*

»i

Sesqaichloride

cc^

Tetrachloride . . CCl*

Di- or Bi-chloride .

OO'

* CBrO hu been recently obtainrd. See Etbtlbnbs, Biomiiiat«d.

CARBON; CHLORIDES OF. 765

There is, liowever, noreal dxstinetioii between these four compounds and others formed
of the same two elements^ excepting that they are of lower atomic weight, and that
they may be derived from disulphide of carbon, the vapour of that substance mixed
with chlorine and passed through a hot tube yielding the tetrachloride, and the
other three being produced, either by exposing this compound to a higher temperature
or by the action of reducing agents.

TstbachlobidbofCabbon, CCl*. Dichloride or Bichloride of Carbon. Car-
hoTtic chloride* PercMorinaUd Chloride of MethyL PercMoroformene. — This compound,
which is an analogue of marsh-gas CH^ and of carbonic tmhydride CO*, was disco-
vered by Begnault in 1839 fAnn. Ch. Phys. [2] Ixxi. 337). It is produced : 1. By
the action of chlorine on marsh-gas (Dumas, Ann. Ch. Phys. [3] Ixxiii. 95). — 2. By
the action of chlorine on chloroform in sunshine: CHOP + CP « HCl + CC1\
Chloroform is gently heated in a retort exposed to the sun, and a stream of dry chlo-
rine is passed slowly and continuously through it, the liquid which distils over being
repeatedly poured back till hydrochloric acid ceases to be evolved, after which the dis-
tillate is agitated with mercury to remove free chlorine, and then rectified (K e gn a u 1 1).
—3. By the action of chlorine on disulphide of carbon : CS« + 4C1« = CCl* + 2SC1*.
Chlorine saturated with vapour of sulphide of carbon by passing through the liquid is
made to pass through a red-hot tube containing fragments of porcelain and connected
with a receiver surrounded with ice ; and the yellowish-red mixture of tetrachloride of
carbon and chloride of sulphur thereby obtained is very slowly added to an excess of
potash-ley or milk of lime, the mixture being agitated from tune to time and after-
wards distilled. Tetrachloride of carbon then passes over, sometimes mixed with
sulphide of carbon, if too much of that compound was mixed with the chlorine, or if
the heat was not strong enough ; the sulphide of carbon may be removed by leaving
the liquid for some time in contact with potash-ley (Eolbe, Ann. Ch. Pharm. xlv. 41 ;
liv. 146). Geuther {jUnd. evii. 212) removes the sulphide of carbon, by dissolving
the mixture in alcohol, adding alcoholic potash as long as it thereby acquires a darker
colour, and heating the liquid gently to promote the conversion of the sulphide of carbon
into xanthate of potassium ; then separates the unaltered chloride of carbon by water ;
and purifies it by washing.>-4. By the action of pentachloride of antimony on disulphide
of carbon:

cs« + 2Sba» - ca* + 2Sba« + s^

The mixture becomes hot, and on cooling deposits crystals of trichloride of antimony
mixed with sulphur, while tetrachloride of carbon remains in the liquid state. (Hof-
mann, Chem. Soc. Qu. J. xiii. 65.)

Properties. — Tetrachloride of carbon is a thin transparent colourless oil, having a
pungent aromatic odour. Specific gravity 1:56. Boiling point 77" C. Vapour-density

by experiment 5*24 — 5*83, representing a condensation to 2 vols. I — -I x

0*0693 ^ 5*34.) It is insoluble in water, but soluble in alcohol and in ether.

J)ecomposiiio9is. — ^Tetrachloride of barbon passed through a red-hot tube, is resolved
into free chlorine and a lower chloride of carbon, which, at a bright red heat is chiefly
CK)\\ at a still higher temperature C*C1^ and at a dull red heat, a body isomeric with
CCl*, but having only half the vapour^density of that compound (Begnault). —
2. When mixed with hydrogen and passed through a red-hot tube filled with pumice, it
yields marsh-gas and ethylene (Berth e lot, Ann. Ch. Phys. Uii. 69; Jahresber. d.
Chem. 1858, p. 519). — 3. With etdphuretied hydrogen, in like manner, at a low red
heat it jdelds hydrochloric acid and sulphochloride of carbon, CCP -i- H'S » 2HC1 +
CSCl* (Kolbe). — 4. Dissolved in weak alcohol and treated with amalgam ofpotas-
eium, it gives off part of its chlorine to the potassium, and yields chloroform, CHCl',
mono-chlorinated chloride of methyl, CH'CP, and marsh-gas (Begnault). — 5. Treated
in a flask provided with an upright condensing tube with sine aiul dilute acid, it yields
hydrochloric acid and chloroform, the latter being converted by the further reducing
action of the mixture, into a body containing still less chlorine, probably CKK?1'
(Geuther, loc. ciL)'~6. It is not decomposed by a(^ueous potash or sulphydrate of
potassium; but alcoholic potash slowly converts it into chloride and carbonate of
potassium (Begnault). Heated with alcoholic potash to 100° C. in a sealed tube
for a week, it is partly converted into ethylene (Bert he lot, Ann. Ch. Pharm. cix.
118).— 7. Heated to 170° or 180° C. with 3 vols, phenylamine, it yields carbotri-
phenyltriamine (Hofmann, Proc Boy. Soc ix. 284) :

6(N.H«.e'H») -H Ca* « rN'.'e.(C«H»)».H«].Ha + 3[(N.H«.0»H*).HC1].
FhmiyUmine. Hjrdrocblorate of carbotri- Hydrochlorkte or

phenyllriamine. Fhenylamiue.

8. With triethylphospMne it yields a white crystalline product. (Hofmann, ibid. x«
184.)

766 CARBON: CHLORIDES OF.

A compound, GCl'^SO', formed by the action of moist chlorine on sulphide of eaihoiL
fiometimes regarded as ndphiU of tetrachloride ofearbatif bat more probably a dilori-
nated deriyative of methyt^ulphu/rous add, -will be described under that head.

TniOHLOBiDB OF Cabbow. C*C1*. Sesquiichhrideof Carbon,' Berehloride of Car-
bon, Perchlorinated Chloride of Ethylene, Chlorure de Chloroxithose, — This compound,
which was discovered and investigited by Faraday (PhiL Trans. 1826, p. 47), and
further by Regnault (Ann. Ch. fhys. [2] box. 166; Ittti'. 371^ is produced &r tbe
action of chlorine in sunshine on Tarious compounds and derivatives of ethyl and
ethylene: 1. On dichloride of carbon, C*C1* (Faraday). — 2. On chloride of ethylene :
C^H^Cl' + 401* » 4HC1 + G'01« ; the action also takes place, though more slowly in
diffused daylight (Faraday), or with aid of heat (Lie big). — 3. On chloride of ethyl,
first in the sh^e, afterwards in sunshine : C*H*C1 + 601' « 6HC1 + C*C1* (Laurent,
Ann. Ch. Phys. [2] Ixxxiv. 828) ; similarly on mono-, di-, or tri-chlorinated chloride of
ethyl (Resnauit). — 4. On sulphite of ethyl, with simultaneous formation of chlo-
ride of sulphuryl, chloraldehyde, and hydrochloric add (Ebelmen and Bouquet,
Ann. Oh. Phys. [3] xvii. 66) :

(c«H»)«so» + iia« - cKn« + soKa« + chuh) + iohcl

6. On oxide of ethyl, which, in bright sunshine, is Fometimes converted at once into
sesquichloride of carbon and chloraldehyde, sometimes into perchloret^lic oxide,
C*C1*«0, 1 at of which is resolved by distiUation into 0*01*0 and OKJ^ (Begnault,
Malaguti). Several perchlorinated compound ethers (carbonic, succinic, ice.) also
yield tridiloride of carbon, when similarly treated. — 6. On hydiochlorate of etfay-
lamine:

CmTS + 601* -= C«a« + NH*C1 + 3HCL

The sal-ammoniac is ultimately resolved by the excess of chlorine into hydrochlorie
acid and nitrogen, which escapes, a certain portion, being, however, convert.ed into chlo-
ride of nitrogen (G-euthcT and Hofacker, Ann. Ch. Pharm. cviiL 51). The formation
of chloride of nitrogen must render the process dangerous. — 7. Tetrachloride of carbon
passed through a red-hot tube is resolved into the trichloride and free chlorine (p. 765).

Preparation. — L Chloride of ethylene is exposed to the sun in a bottle filled with
chlorine, water being' frequently added in small portions to absorb the hydrochloric
acid produced, and me chlorine frequently renewed as long as any action is percep-
tible. The crystalline product is washed with water, pressed between bibulous paper,
heated to sublimation, then dissolved in alcohol, precipitated by water containing
potash, again washed with water, pressed, and dried in vacuo over snlphurie acid
(Faraday). By passing chlorine through chloride of ethylene, heated nearly to the
boHing point, part of that compound is converted into trichloride of carbon, iriueh
crystallises out for the moat part on cooling the liquid with ice (Liebig, Aim. Ch.
Pharm. i. 219). — 2. A bottle filled with chlorine, and containing a little chloride of
ethyl, is set aside in the shade for twenty-four hours, the chlorine then renewed and
the vessel exposed to the sun : such exposure at the beginning of the process would
produce explosion (Laurent). Or better : vapour of chloride of ethyl produced by heat-
ing alcohol with strong hydrochloric acid, and purified by passing through water and
oil of vitriol, is brought in contact with chlorine in a vessel exposed to the summer son
(Regnault).~8. Perchlorethylic oxide (CKTl'^'O) is distilled, and the distJUate is re-
peatedly treated with water, which takes up chloraldehyde and leaves tzichloride of
carbon. (Malaguti, Ann. Ch. Ph3r8. [3] xvi. 6, 14.)

Propertiee. — Trichloride of carbon crystallises in right rhombic prisms odP, mo-
dified by the faces oo I* od and the horizontal prism P oo. Angles of the prism obP ^
58^ and 122^ (Brooke) ; 69^ and 121° (Laurent). The crystals are colouriess, tran-
sparent, and nearly tasteless, but have an aromatic camphorous odour.. They are as
hard as sugar, and easily pulverised. Specific gravity « 2'0. Refracting power «
1*6767. They do not conduct electricity. They melt at 160° C. ; boil and sublime at
182°, and volatilise even at ordinary temperatures. Vapour-density « 8*157, corre-
sponding to 2 volumes f— ^ ^— ^ X 0*0693 « 8'212j. Insoluble in water,

soluble in alcohol, still more in ether ; the solutions are not donded by nitrate of silver.
Sohible also in oils, both fixed and volatile.

Decompositions. — 1. By repeated distiUation, or by passing its vapour through a red-
hot porcelain tube, the trichloride is resolved into the mchloride, C*C1\ and free
chlorine. -> 2. It bums with a red light in the fiame of a spirit-lamp, but is extinguished
on removal.— 8. Passed, together with hydrogen, through a red-hot tube, it yields
hydrochloric acid and dichloride of carbon (Geuther), and undergoes a similar de-
composition when heated with sulphtir, phosphorus, or iodine. — 4. Most metals heated
in the vapour of the trichloride are converted into chlorides, with separation of char-

CARBON: CHLORIDES OF. 767

eoaL — 5. The yaponr passed over red-hot baryta^ strontia, or limet yields a chloride
and carbonate of the metal, with deposition of charcoal ; with oxide of gine^ it some«
times forms ozychloride of carbon ; with the oxides of copper and mercury^ and with
peroxide of lead^ the products are metallic chloride and carbonic anhydride. — 6. The
trichloride is not altered by distillation with aqneons or alcoholic potash ; but when
gently heated with an alcoholic solution of stdpkydrate of potassiumj it yields dichlo-
ride of carbon, together with chloride of potassium, sulphydric acid, free sulphur, and
a brown sulphur compound, apparently resulting from a secondary action (Begnault) :

c«ci« + 2b:hs « c*ci^ + 2Ka + h«s + s.

7. Heated in sealed tubes with 8 at hydrate ofpotaesium^ it yields oxalate and chloride
of potassium :

(KJl* + 8KH0 - C?K«0* + 6KC1 + 4H*0 ;

but the decomposition is veiy imperfect, even when the mixture is heated to between
210° and 220° C. for several days (Geuther, Ann. Ch. Pharm. Ix. 247).— 8. Heated to
100° C. in sealed tubes with alcoholic potash^ ityields the same products, together wiUi
hydrogen gas and ethylene (Bert helot, Ann. Ch. Pharm. dx. 118). The principal re-
action ia probably represented by the equation :

C*a« + 7KH0 + C«H».K.O - CK'O* + 6KC1 + 4H«0 + CH*,

and the £ree hydro^n results from a secondaiy decomposition, a number of liqtud
products and brown insoluble substances being formed at the same time. Trichloride
of carbon is not attacked by ammonia, nitric add, or sulphuric acid. Boiling nitric
acid dissolves it) part separating on cooling, the rest on addition of water. In contact
with chlorine and water, it does not yield trichloracetic acid.

DxohlobidbofCabbon. C*C1*. Protochloride of Carbon, Perchlorethylene^ Ch!o-
rethoee. — Discovered and examined by Faraday (Phil. Trans. 1821, p. 47), further by
Begnault (Ann. Ch. Phys. [2] Ixx. 104 ; Ixxxi. 372). It is produced by the action of a
red heat on the trichloride or tetrachloride of carbon, either alone or in presence of
hydrogen (pp. 765, 766) ; by the action of nascent hydrogen on the trichloride at ordinary
temperatui^ ; alfso by that of alcoholic sulphydrate of potassium on the trichloride, and
of alcoholic potash on the tetrachloride (p. 765).

Preparation, — 1. Vapour of trichloride of carbon is passed through a red-hot tube filled
with fragments of glass, whereupon a lar^e quantity of chlorine is set free, and the di-
chloride passes over in the form of a liquid coloured yellow by chlorine. It is purified
by passing it several times through the red-hot tube, then shaking it up with mercury,
and rectifying at as low a temperature as possible (Faraday). — 2. The trichloride is
added by small portions to an flJcoholie solution of sulphydrate of potassium, and, as soon
as the evolution of sulphuretted hydrogen has ceased, the liquid is distilled, and the alco-
holic distillate diluted with water: the dichloride then separates in the form of a heavy
liquid: this process is eaflier than the preceding (Kegnault).— 3. Trichloride of car-
bon is mixed with water and granulated zinc, and sulphuric acid added from time to
time with agitation, till all the trichloride is decomposed. On subsequently distilling
the liquid, dichloride of carbon passes over with the aqueous vapour. (Geuther,
Ann. Ch. Pharm. cvii. 212.)

Properties, — Very mobile liquid, of spedfic gravity 1'619 at 20® C. (Kegnault),
1*612 at 10® (Geuther). Eefractinff power <= 1*4875 (Wollaston). It does not
conduct electricity. It remains liquid at— 18® C. ; boils at 122® (Regnault), 116*7®
(Geuther). Vapour^density, by experiment « 5*82, corresponding to 2 volumes.

( — ^ X 0*0693 « 6*75. j It is insoluble in water, adds, and aqueous al-
kalis, but dissolves in alcohol, ether, and oils, both fixed and volatile.

Decompositions. — 1. At a red heat it is resolved into free chlorine and the proto-
chloride, C*C1'. — 2. When its vapour is passed over red-hot baryta, vivid ignition
takes place, with formation of chloride of barium and carbonic anhydride, and separa-
tion of charcoal. — 3. Heated for some time to 200® C, with 6 at. hydrate of potassium,
it is completely converted into oxalate and chloride of potassium, with evolution of
hydrogen gas (Geuther, Ann. Ch. Pharm. ex. 247):

C«C1* + 6KH0 - C«K«0< + 4KC1 + 2H»0 + H».

4. It absorbs dry chlorine in sunshine, forming the trichloride, C^Cl*; but if exposed
to an atmosphere of chlorine under a layer of water, it yields trichloracetic acid.
(Kolbe, Ann. Ch. Pharm. liv. 181) :

C«C1< + 2H'0 + Cl« - C»Ha>0« + 3HC1.

5. It absorbs bromine in sunshine, yielding chlorobromido of carbon, CKll^Br^.

766 CARBON: CHLORIDES OF.

A compound, OCl^SO', fonned by the action of moist chlorine on snlphide of oflriKm.
sometimes regarded as sulphite of tetrachloride of carbon, bat more probably a ehkni-
nated deriyatire of methyt-eul/phuroue acid, will be described under that head.

Triohlobidb of Cabboit. C*C1*. Seeqmchlorideof Carbon,' Perchloride of Car-
bon, Pcrchlorinated Chloride of Ethylene, Chlarure de Chhroxithoee, — This componnd,
which was discoyered and inyesti^ted by Faraday (PhiL Trans. 1826, pi 47), and
farther by Begnanlt (Ann. Ch. Fhys. [2] Izix. 166; Inri. 371), is produced by the
action of chlorine in sunshine on yarious compounds and deriyatiyes of ethyl and
ethylene: 1. On dichloride of carbon, CPCi* (Faraday). — 2. On chloride of ethylene :
C^H^CI* 4- 401< » 4HC1 + G*01* ; the action also takes place, though more slowly in
diffused daylight (Faraday), or with aid of heat (Liebig). — 3. On chloride of ethyl,
first in the shade, afterwards in sunshine : C*H*C1 + 6C1» = fiHCl + C*C1« (Laurent^
Ann. Ch. Phys. [2] Ixzxiy. 328) ; similarly on mono-, di-, or tri-chlorinated chloride of
ethyl (Reffuault). — 4. On sulphite of ethyl, with simultaneous formation of chlo-
ride of sulphuiyl, chloraldehyde, and hydrochloric acid (Ebelmen and Bouquet^
Ann. Oh. Phys. [3] xyii 66) :

(C«H»)^0» + 11C1« - C*C1« + so«a« + C«C1«0 + IOHCL

5. On oxide of ethyl, which, in bright sunshine, is sometimes conyerted at once into
sesquichloride of carbon and chloraldehyde, sometimes into perchlorethylic oadde,
C^CPK), 1 at of which is resolyed by distillation into C*a*0 and C*CP (Kegnault.
Malaguti). Seyeral perchlorinated compound ethers (carbonic, succinic, Bsc) also
yield trichloride of carbon, when similarly treated. — 6. On hydrochlorate of ethy-
lamine:

0«H'N + 6CP = CHjy + NH*C1 + 8HGL

The sal-ammoniac is ultimately resolyed by the excess of chlorine into hydrochloric
acid and nitrogen, which escapes, a certain portion, being, howeyer, conyerted into chlo-
ride of nitrogen (Oeuth er and Hofacker, Ann. Ch. Phann. cyiu. 51V. The formation
of chloride of nitrogen must render the process dangerous, — 7. Tetracmoride of carbon
passed through a rod-hot tube is resolyed into the trichloride and firee chlorine (p. 765).

Preparation. — L Chloride of ethylene is exposed to the sun in a bottle filled with
chlorine, water being' *&equently added in small portions to absorb the hydrochloric
acid produced, and the chlorine frequently renewed as long as any action is percep-
tible. The crystaUine product is washed with water, pressed between bibuloos paper,
heated to sublimation, then dissolyed in alcohol, precipitated by water oontoiniiig
potash, again washed with water, pressed, and dried in yacuo oyer sulphuric acid
(Faraday). By passing chlorine through chloride of ethylen€^ heated nearly to the
boiling point, part of that compound is oonyerted into trichloride of carbon, which
crystalbses out for the most part on cooling the liquid with ice (Liebig, Ajm. Ch.
Pharm. i. 219). — 2. A bottle filled with chlorine, and containing a little chloride of
ethyl, is set aside in the shade for twenty-four hourS) the chlorine then renewed and
the yessel exposed to the sun : such exposure at the beginning of the process would
produce explosion (Laurent). Or better : yapour of chloride of ethyl produced by heat-
ing alcohol with strong hydiochloric acid, and purified by passing through water and
oil of yitriol, is brought in contActwith chlorine in a yessel exposed to the summer sun
(Regnault).— 8. Perchlorethylic oxide (CK)1"0) is distilled, and the distillate is re-
peatedly treated with water, which takes up chloraldehyde and leayes tziehloride of
carbon. (Malaguti, Ann. Ch. Phys. [3] xyi. 6, 14.)

Properties. — Trichloride of carbon crystallises in right rhombic prisms ooP, mo-
dified by the faces oo f* oo and the horizontal prism P oo. Angles of the prism ooP »
58^ and 122^ (Brooke) ; 69° and 121° (Laurent). The crystals are colourless, tran-
sparent, and nearly tasteless, but haye an aromatic camphorous odour. They are as
hard as sugar, and easily pulyerised. Specific grayity « 2*0. Befracting power »
1-6767. They do not conduct electricity. They melt at 160° C. ; boil and sublime at
182°, and yolatiLise eyen at ordinary temperatures. Vapour-density a 8'167, corre-
sponding to 2 yolumes [ — ^ 5 — X 0*0693 « 8*212 j. Lisoluble in water,

soluble in alcohol^ still more in ether; the solutions are not donded by nitrate of sityer.
Soluble also in oils, both fixed and yolatile.

Decompositions, — 1. By repeated distillation, or by passing its yapour through a red-
hot porcelain tube, the trichloride is resolyed into the dichloride, CH}1\ and free
chlonne.— 2. It bums with a red light in the fiame of a spirit-lamp, but is extinguished
on remoyaL— 8. Passed, together with hydrogen, through a red-hot tube, it yields
hydrochloric acid and dichloride of carbon (Gent her), and undergoes a similar de-
composition when heated with sulphur, phosphorus, or iodine, — 4. Most metals heated
in the yapour of the trichloride are converted into chlorides, with separation of char^

CARBON: CHLORIDES OF. 7<>7

eoaL — 5. The Taponr passed otot red-hot baryta^ strontia, or lirMy yields a chloride
and carbonate of the metal, with deposition of charcoal ; with oxide of einOf it some-
timee forms oxychloride of carbon ; with the oxides of copper and mercury ^ and with
peroxide of lead, the products are metallic chloride and carbonic anhydride. — 6. The
trichloride is not altered by distillation with aqueons or alcoholic potash ; but when
gently heated with an alcoholic solution of svlpkydrate of poiaaeium, it yields dichlo-
ride of carbon, together with chloride of potassium, sulphydric acid, free sulphur, and
a brown sulphur compound, apparently resulting from a secondary action (Regnault) :

CKH' + 2KH8 « C»C1* + 2KCI + H«S + 8.

7. Heated in sealed tubes with 8 at hydrate of potassium, it yields oxalate and chloride
of potassium :

CKn* + 8KH0 - C«KK)« + 6KCI + 4H«0 ;

but the decomposition is yeiy imperfect, eren when the mixture is heated to between
210® and 220° C. for seTeral days (Qeut her, Ann. Ch. Pharm. Ix. 247).— 8. Heated to
100® C. in sealed tubes with alcoholic potash, it yields the same products, together with
hydrogen gas and ethylene (Berth elot, Ann. CL Pharm. dx. 118). The principal re-
action is probably represented by the equation :

CHJi* + TKHO + C«H»KO - C«K»0«.+ 6KC1 + 4H«0 + CH*,

and the free hydro^n results from a secondary decomposition, a number of liquid
products and brown msoluble substances being formed at the same time. Trichloride
of carbon is not attacked by ammonia, nitric add, or sulphuric acid. Boiling nitric
acid dissolves it, part separating on cooling, the rest on addition of water. In contact
with chlorine and water, it does not yield trichloracetic add.

DiOHLOBiDB ofCabbon. CCl*. Protochlortde of Corbon, PcTchlorethylene, Chlo-
rethose. — Discovered and examined by Faraday (Phil. Trans. 1821, p. 47), further by
Begnault (Ann. Ch. Phys. [2] Ixx. 104 ; Ixxxi. 372). It is produced by the action of a
red heat on the trichloride or tetrachloride of carbon, either alone or in presence of
hydrogen (pp. 765, 766) ; by the action of nascent hydrogen on the trichloride at ordinary
temperatures ; also by that of alcoholic sulphydrate of potassium on the trichloride, and
of alcoholic potash on the tetrachloride (p. 765).

Preparation, — 1. Vapour of trichloride of carbon is passed through a red-hot tube filled
with fragments of glass, whereupon a lar^e quantity of chlorine is set free, and tin di-
chloride passes over in the form of a liquid coloured yellow by chlorine. It is purified
by passing it several times through the red-hot tube, then shaking it up with mercury,
and rectifying at as low a temperature as possible (Faraday). — 2. The trichloride is
added by sm^ portions to an adcoholic solution of sulphydrate of potassium, and, as soon
as the evolution of sulphuretted hydrogen has ceased, the liquid is distilled, and the alco-
holic distillate diluted with water: the dichloride then separates in the form of a heavy
liquid: this process is easier than the preceding (Regnault). — 3. Trichloride of car-
bon is mixed with water and granulated zinc, and sulphuric add added from time to
time with agitation, till all the trichloride is decomposed. On subsequently distilling
the liquid, didUoride of carbon passes over with the aqueous vapour. (Geuther,
Ann. Ch. Pharm. cviL 212.)

Praperties, — ^Very mobile liquid, of specific gravity 1*619 at 20° C. (Begnault),
1-612 at 10*^ (Geuther). Befracting power = 1-4876 (WoUaston). It does not
conduct electridty. It remains liquid at~18° C; boils at \27P (Begnault), 116-7°
(Geuther). Vapour-density, by experiment a 5*82, corresponding to 2 volumes.

f — —-^ X 0*0693 ■■ 6*76. J It is insoluble in water, adds, and aqueous al-
kalis, but dissolves in alcohol, ether, and oils, both fixed and volatile.

Decompositions. — 1. At a red heat it is resolved into firee chlorine and the proto-
cbloride, CCl*. — 2. "When its vapour is passed over red-hot baryta, vivid ignition
takes place, with formation of chloride of barium and carbonic anhydride, and separa-
tion of charcoal — 3. Heated for some time to 200° C, with 6 at hydrate of potassium,
it is completely converted into oxalate and chloride of potassium, with evolution of
hydrogen gas (Geuther, Ann. Ch. Pharm. ex. 247):

C»a* + 6KH0 = C»K*0* + 4KC1 + 2H*0 + H«.

4. It absorbs dry chlorine in sunshine, forming the trichloride, C'Cl' ; but if exposed
to an atmosphere of chlorine under a layer of water, it yields trichloracetic acid.
(Kolbe, Ann. Ch. Pharm. liv. 181) :

c*ci* + 2H'o + a« « c^a«o* + shci.

6. It absorbs bromine in sunshine, yielding chlorobromido of carbon, CKJl^Br^.

r
I

768 CARBON : DETECTION AND ESTIMATION.

Pbotoohlobide op Cabbon, C*C1*. Subchloride of Carbon, JuUn's Chloride of
Carbon. — This compound was discovered is 1821, by Julin, a manufactiirer of u'trie
acid at Abo in Finland, who obtained it accidentally in distilling crnde nitre with burnt
green vitriol in cast-iron retorts, the cast-iron probably famishing the carbon, and the
crude nitre the chlorine (Ann. Ch. Phys. [2] xviii. 269). It was more exactly in-
vestigated by Phillips and Faraday (Phil. Trans. 1821), and afterwards by Keg-
nault (Ann. Ch. Phys. [2] Izx. 104), who prepared it by passing vapour of chlorofiiim
or of dichloride of carbon, through a strongly ignited porcelain tube filled with frag-
ments of porcelain, dissolving the crystalline product in ether, filtering, evaporating to
dryness, and subliming. In performing this process, care must be taken not to heat
the porcelain tube too strongly ; otherwise, no chloride of carbon will be obtained, but
only a deposit of charcoaL

Properties. — ^Protochloride of carbon forms white, delicate needles, apparently four-
sided, having a silky lustre. It melts, boils, and sublimes between 176^ and 200^ C,
but may be sublimed without fusion at 120^, the sublimate then consisting of long
needles. It has a peculiar odour, something like that of spermaceti, but no taste In
tlie cold it is almost inodorous. It is insoluble in water, but very soluble in alcohol ;
dissolves also in ether, and in hot oil of turpentine, whence it czystallisea in needles
on cooling.

The alcoholic solution does not precipitate nitrate of silver.

The vapour passed through a rod-hot porcelain tube filled with fragments of rock-
crystal, is resolved into chlorine and charcoal The compound bums with bluish eolour
in the flame of a candle, but ceases to burn when withdrawn. It is not decomposed
or dissolved by nitric, hydrochloric, or sulphuric acid, or by boiling potash. Chlorine
does not act upon it, even in sunshine. Potassium bums in its vapoar with intense
ignition, forming chloride of pota.ssium and depositing charcoaL

Berthelot regards this compound, not as C*C1*, but as C**CP*. The Taponr^ensity
does not appear to have been determined.

CAMMOM, OB&OXOBROBKZBB OV. C*Cl*Br*. Bromide of PtrcharetJkylene^
Bromure de ChloroxHhose, (Malaguti, Ann. Ch. Ph^s. [3] xvi. 14.) — Dichlonde of
carbon exposed to sunshine in contact with bromine solidifies in a few hours to a oys-
talline mass, which may be purified by repeated crystallisation from aloohoL The crys-
tals resemble those of C^Cl' ; they have a specific gravity of 2'3 at 21^ C, taste slightlpr
aromatic, begin to volatilise at 100^, decompose at about 200^ into bromine and the di-
chlonde, and when treated with protosulphide of potassium are resolved into bromide
of potassium and dichloride of carbon :

C«Cl«Br» + K*S « CKn* + 2KBr + S.

CABBOB, BBTBCTIOB ABB BSTIBKATZOB Or. The methods of de-
tecting and estimating carbon and its compounds have been already described mider the
head of Anax.tsi8.

If the carbon is not already in the form of carbonic anhydride or a carbonate, it is
converted into carbonic anhydride by combustion, either in an atmosphere of oxygen or
with oxide of copper or chromate of lead, the amount of carbonic anhydride therel^ pro-
duced being estimated by absorption in strong potash-ley (Analysis, Organic, pp. 22^
— 238). This method serves for the estimation of carbon in cast-iron and other metallic
compounds, as well as in organic bodies. Gaseous carbon-eompounds, such as carbonic
oxide and hydrocarbons, are converted into carbonic anhydride by explosion with ex-
cess of oxygen, the amount of that compound produced being then determined by
absorption with potash. (Analysis, Volumbtbio, of Gasbs, pp. 286 — 288.)

Carbonates are decomposed with dilute sulphuric or hydrochloric acid, ana the car-
bonic anhydride thereby evolved is usually determined by loss (see AciDmTST, p. 38,
and Alxalikbtbt, p. 149). The presence of carbonates in any mixture, solid or liquid,
is detected by the effervescence wnich ensues on addition of dilute sulphuric or hydro-
chloric acid. This effervescence may, however, arise from the escape of snlphydrie
acid or sulphurous anhydride, if sulphides or sulphites are also present. These gases
are readily distinguished from carbonic anhydride by their peculiar odours ; snlphydrie
acid also by its property of blackening lead-salts. To detect carbonic anhydrioe when
evolved together with one or both of these gases, the gaseous mixture is passed into
baryta-water. If a precipitate is formed, carbonic or sulphurous add may be present
or both ; if the former alone, the precipitate will be completely soluble in nydrochlorie
acid, after treatment with chlorine-water; but if sulphurous acid is also present^ it will
be oxidised by the chlorine-water, and converted into sulphuric add, which w^ then
form sulphate of barium, insoluble in hydrochloric add.

The amount of carbonic anhydride in a gaseous mixture is ascertained directly by
absorption with potash, sulphurous anhydride or sulphydric add, if present, having
been previously removed by absorption with peroxide of manganese (p. 282).

CARBON: ESTIMATION. 769

Gaibome acid in solution, either free or combined, in a mineral water for example,
18 estimated by adding ammonia and chloride of calcium, and leaving the liquid to
itself in a corked flask for seyend hours. The carbonic acid is thereby precipitated as
carbonate of calcium, containing 43*88 per cent. GO^

To estimate the carbonic acid in the air, a large quantity of air, the volume being
measured by an aspirator (p. 427), is passed throu||;h a series of weighed potash-bulbs.
Another method is to shake up a quantity of air in a closed vessel of known capacity,
with an excess of lime-water of known strength, and then determine the quantity of
lime remaining uncombined by means of a standard solution of oxalic add. This
method is easy of execution, and aflfords the means of quickly determining the varying
amount of carbonic add in the several parts of an iiUiabited apartment at different
times.

Atomic Weiahi of Carbotu^-ThreB methods have been adopted for determining
the atomic wei^nt of carbon : 1. From the quantity of carbonic anhydride produced
by the combustion of a given weight of carbon. — 2. dj comparing the weights of equal
volumes of carbonic anhydride and oxygen, it being supposed that carbonic anhydride
contains its own volume of oxygen. — 8. ifxom the weight of metallic diver obtained
by the combustion of organic olver-salts.

Of these methods the first is considered the most trustworthy. The amount of car-
bonic anhydride produced by tiie combustion of carbon was aetermined with a very
near approximation to the truth by Lavoisier in 1775, afterwards with more or less
aeeoracy by Guyton-Morveau (1785), CUment and Desormes (1802), Allen and I'epys

il807)» and Saussure U809) ; but &e most exact determinations are those made by
>uma8 and Stas (Ann. Gh. Fhys. [3] i IX and by Erdmann and Marchand
(J. pr. Chem. xxiii. 169). These chemists burned weighed quantities of diamoncl or
graphite with oxide of copper and oxygen gas, and weighed the carbonic anhydride
taken up by the potash-apparatus, after it had been £reed from a very small quantity
of admixed water by passing over chloride of caldum or sulphuric acid. The smaU
quantity of reddual ash was deducted from the weight of the carbon employed, and
tiie quantity of water produced in the combustion likewise taken into account.

In this manner the quantity of carbon which combines with 200 pte. of oxygen to
fonn carbonic anhydride was found by Dumas and Stas, in fourteen experiments, to
vary only between the limits 74*87 and 75*12, the mean result being 75*005, with a pro«
bable ezror of + 0*013. Erdmann and March an^ in nine experiments similarly con-
ducted, obtained numbers varying between 74*84 and 75*19, the mean being 75*028. Now
since^ of the two oxides of carbon, carbonic anhydride contains, with the same quantity
of carbon, twice as much oxygen as carbonic oxide, these compounds maybe represented
by the fiiimnlsB CO* and CO, a view of their constitution, which is likewise in accord-
ance with that of the other compounds of carbon. Hence, from the above-mentioned
results respecting the eompodtion of carbonic anhydride, it follows that if the atomio
weight of oxygen « 100, tiiat of carbon will be 75, and on the hydrogen scale :

If 0-8, C » 6

and if 0 « 16, C - 12.

The reason for adopting the numbers in the last line are fUly detailed in the article
Afomo WnxoHTs (pp. 459 — 462).

The seeond method of determining the atomic weight of carbon was first adopted by
Berselius and Dulong in 1819. From specific gravity determinations then made it
was oonduded tiiat eqtlal volumes of carbonic a^ydnde and oxygen wdghed 1*5425
and 1*1026 respectivdy; and assuming that carbonic anhydride contained its own
volume of oxygen, the difference of the two numbers gave the weisht of the carbon in
the same volume, whence it was calculated that the atomic wei^t of carbon on the
oxygen scale (O -■ lOO) was 76*528, which number was adopted as correct for twenty
years. In 1841, Wrede, following the same method, but takmff into account the more
exact coeffidents of expansion <^ the gases determined by Kudberg, Magnus, and
Begnault, obtained the number 75*12. Determinations not much differing from this
were made in like manner by other eoroerimenteis ; but the method is not' capable of
yielding very exact results, because the alterations of volume sustained by oxygen
and carbonic anhydride for equal variations of temperature and pressure are not equal,
and consequently the assumption that oxygen, in being converted into carbonic anhy-
dride, undergoes no diange of volume, cannot be true for all temperatures/

The third method, founded on the analyds of the silver-salts of oiganic acids, was
adopted by Liebis and Hedtenbacher (Ann. Ch. Fharm< xxxviii. 116). Assuming
Ag a 13*51 and H e> 12*48 (0 » 100), these chemists obtained as the mean result of
their analyses, C » 7^*854. The more exact determinations since made of the atomio
weight of silver would lead to a dight alteration in this result. Strecker, from the

Vol. L 8 D

770 GABBON: OXIDES.

flame experiments, and without aiwnining the atomio weights of ailTer as preTioaaiy-
known, calculated the atomic weight of carbon aa » 76*415 ; bnt this methoid, aa weQ
as the second, ia not considered so tnistwozthy as the fixate the zeanlt of iriucfa, ob-
tained by Dnmaa and Staa is now uniTeraally adopted.

OAMMiOWt ZOOnUi or* No oomponnd of carbon and iodine has yet been ob-
tained. Iodoform, CHP, was formerly supposed to be an iodideof carbon, the hydngen
contained in it haying been overlooked. (Gm. yiL 335.)

GASB0Vff WZTBHIB 0V« Only one compound of carbon and nitrogen ia
known with certainty, Tis. Ctavooebt, Ci^ {q. v.) Many cyanogen-compounds yield by
calcination a residue called mellone, whidi liebig regards as a nitride of carbon con-
taining O'S*, It does not, however, appear to have been obtained quite free from
hydrceen (see Mellomb and Mellomidbs). According to Thaulow, a peculiar nitride
of carbon, isomeric^ but not identical with (^anogen, is obtained by igmtion of ^anide
of silver (see Cabbazots, p. 757).

OAMMOW9 OXKDWM IMP. Two oxides of carbon are known, the protoxide CO,
and the dioxide, or carbonie anhydride, CO*, commonly called earbome acid. Both are
produced by the direct combination of carbon and oxygen ; the former is known only
in the gaseous state: the latter is gaseous at ordinary temperatures.

Dioxina ov Cabbov. Cabbobio Akhtdbidb, CO*. Anhydroua Carbonie
aeid, Fiaed air, Mepkitie air, kohUnaawreB oat, KoMenMUre, Oas svlvettre^ Bpiritua
aylvea^ria. — ^The evolution of this eas in the burning of Ume and in rermentatioa, was
known to Paracelsus and Van Hdnont^ the latter of whom gave it the name of ^as
wlvestre; its properties were afterwards investigated by ^les, Black, Gavendish*
^estiey, and &rgmann, bnt its true oomposition was first demonstrated by Lavoisier,
who showed that it was a compound of carbon and oxyeen, containing 28 per cent,
carbon and 72 oxygen, numben approaching very neariy to ue proportions now received
as correct, via. 27*27 carbon to 72*73 oxygen (p. 769).

Carbonic anhydride is fixrmed by the combustion of carbon in oxygen gas, or in the
air. It is a constant product of the ordinary processes of combustion, inasnrach as all
substances used for fuel, such as wood, coal, oil, wax, tallow, &c. contain carbon. It is
likewise formed by the respiration of animals, in various processes of fermentation, as
in the preparation of wine and beer, and by the decay of animal and vegetable sub-
stances. It issues from fissures in the ground, in various localities, chiefly in volcanic
districts, and is ejected in enormous quantities from the craters of active volcanoa.
From all these sources it is continually being poured into the atmosphere, of whidi it
therefore forms a constant constituent: the average amount of it contained in the air
in the open country, is 4 volumes in 10,000 ; in tiie air of crowded towns, it ia often
much greater (p. 487). It exists also in larger proportion at the bottom of weHs, mines,
quarries, and caverns, especially in limestone districts, where it is evolved horn
fissures and does not readily escape, in consequence of its greater density. Carbonic
anhydride (or acid), exists also in solution in all natural waters, some, as those of
Selts, Yichy, and Spl^ containing it in such quantity as to give them an eflferveseing
character. Lastly, it is produced by the decomposition of carbonates, either by heat or
by the action of the stronger acids, and is a frsquent product of the decompo8iti<m of
organic bodies at high temperatures.

Preparation. — ^The easiest way of obtaining the gas is to decompose chalk, or maiUe,
with hydrochloric add, in an ordinary generating vessel, provided with a gaa-delxveiy
tube:

Ca«CO« + 2HC1 - 2Ca01 •«• CO* + BPO.

Dilute sulphuric acid may also be used, but it is less convenient^ aa the sulphate of
calcium procraced forms a hard mass in the vessel, which is difficult to extract, whereas
chloride of calcium is easily soluble : moreover, the chloride is more useful as a resi-
duid product The eas may be received over water, or, aa it is vezj heavy, it may be
colle<^ed by simple displacement of the air, the deliverjr-tube bein^ bent vertically
downwards, so aa lo reach to the bottom of the receiver. Thia is also the most
convenient mode of collection when the gas is required dir, a desiccating tube contain-
ing dry chloride of calcium or pumice-stone soaked in oil of vitriol, being interpoeed
between the generator and receiver. On the large scale, carbonic anhydride may be
obtained by heating chalk or marble to redness, in an iron or earthen retort

Properties, — Carbonic anhydride is, at ordinary temperatures and pressures, a colour-
less gas, but may be liquefied bv cold or pressure (p. 771). Its specific gravity in the
gaseous 8tatei8l'5241(Regnault), being rather more than 1^ times that of air. In
consequence of this great densilT, it may be poured from one vessel to another like a
Hquid, and often collects at the bottom of wells, mines, jmd caverns, as in the Orotto
del Cane near Naples, the atmosphere of which, within about a foot of the ground, is
highly chaiged with the gas, while the upper part is comparatively free.

From the exporimeats of Regnault, it appears that the density of carbonic anhydride

CARBON: OXIDES. 771

does not vary in the same proportion as the pressure, excepting within narrow limits :
nnder a pressnre of sereral atmospheres, the deviation from this law is yery perceptible.
The coefficient of expansion b^ heat between 0^ and 100^ C. is 0*3719 (Kegnault) ;
0*366087 (Magnus); refracting power « 1*526 (Dulong).

Garbonio anhydride does not afi^ the colour of litmua-ptyiter, when both are quite
dry ; but if moisture is present, the blue colour of the paper changes to wine-red,
like that produced by bono acid : on exposure to the air, howerer, the redness disap-
pears, in consequence of the escape of the gas. Lvme-water introduced into the gas is
unmediately rendered turbid, in consequence of the formation of neutral carbonate of
calcium, but if an excess of the ^s is present, the liquid becomes clear a^ain after a
while^ especially if shaken, an aad carbonate bein£ then formed, which is soluble in
water. Solution of potash, or a lump of moist solid potash, introduced into the gas
standing over mercury, rapidly absorbs it. It dissolves in about its own volume of
water at ordinazy temperatures, and in less than \ of its volume of alcohol.

Carbonic anhydride is irrespirable ; animals immersed in it soon die, not only from
want of oxygen, but in consequence of a direct poisonous action, violent spasms being
sometimes produced, sometimes complete atony of the cerebral faculties. Mixed with
air, as it escapes from effervescing liquids, it produces a pungent sensation in the re-
spiratory organs, but it cannot be said to have any decided odour. It is incombustible,
and immediately extinguishes a bumins taper, also the flame of sulphur or phosphorus :
but potatsium heated to redness in the dry gas, decomposes it completely, burning with
a r^ lights and producing a deposit of charcoal mixed with carbonate of potassium.
Sodium decomposes it in like manner, but without becoming red-hot. Phosphorus and
hofTon^ in presence of an alkali, likewise abstract all the oxygen at a red heat. Hy-
drogen, ckarcoal, iron, and sin/i, at a red heat, abstract half the oxygen, converting
the carbonic anhydride into carbonic oxide. It is also resolved into carbonic oxide ^d
oxygen bj the passage of electric sparks, if hydrogen gas, mercury, or some other
metal is present to take up the oxygen ; otherwise, the spark immediately causes the
eases to reoombine. Growing plants, or the leaves and other green parts separated
from the plant, but still in the firesh state, decompose carbonic anhydride completely
imder the influence of daylight, and more rapidly in direct sunshine, abstracting the
whole of the carbon, and setting the oxygen fcee. If some fresh leaves of any plant
be placed in an inverted receiver, fllled with water containing carbonic acid, and stand-
ing over water, and the whole' be exposed to the sun, a considerable quantity of
oxygen gas will collect at the top of the receiver in a few hours. This action of
growing plants is the chief cause which prevents the continual accumulation of car-
bonic uihydride in the atmosphere, and keeps the proportion of it nearly constant.
(See Aticospexbb, p. 438.)

Respecting the mode of determining the composition of carbonic anhydride, see
pu 769. Its density corresponds to 2 volumes of vapour :

^^"^^'^^ X 0*0693 - 22 X 0*0693 « 1*5246

and at pressures and tomperatures considerably above its liquefying point, it contains
a volume of oxygen exactly equal to its own.

Liquid Carbonic Anhydride^Caihoma anhydride passes to the liquid stato at 0^ C.
under a pressure of 36 atmospheres. Faraday effected the liquefaction by evolving the
m from carbonate of ammonia, by the action of sulphuric acid in a sealed tube (see
Gasbs, Coin>BNSA.TiON of), but the method is dangerous^ and yields but a small quantity.
The liquid add is however obtained safely and in large quantity, by the method of
Thilorier (Ann. Ch. Pharm. xxx. 122). The apparatus consists of two very strone
(flinders, capable of holding 6 litres or pints, made of cast-iron, or better, of lead
sneathed wim copper, and s&engthened with a wrought-iron armature ; tbey rest b}
two pins placed at the middle of their length on cast-iron supports, so that they may
be placed either vertically or horizontally, and swung backwurds and forwards. Into
one of these cylinders is introduced 1800 grammes of acid carbonate of sodium, and
4 litres of water (or 4} lbs. of the soda-sal^ and 7 pints of water), and a copper tube
containing 1000 grammes (or 2i lbs.) of strong sulphuric acid^ is likewise introduced
in a vertical position. The cylinder is then tightly closed by a cock of peculiar con-
struction, and swung to and fro, to cause the acid to mix gradually with the carbonate.
The gas is then evolved, and not being able to escape, becomes so much condensed that
it passes to the liquid state. This part of the operation requires care^ as, if the mix-
ture be made too rapidly, great heat will be evolved, and the tension of the gas
enormously increased. A fatal accident happened in Paris from this cause. When
the action is supposed to be complete, the generating cylinder is made to communicate,
by means of a copper tube, with the second cylinder, which is placed horizontally, and
provided ^th a stopcock like the first. This cylinder being slightly cooled, the car-

3d 2

772

CARBON: OXIDES.

borne anhydride distils over ftom the first, which is still warm, and oondeiiseB in the
liquid state. After about a minute the cocks are dosed, the (flinders s^wrated, tht*
charge in the first renewed ; and this series of operations is repc^ated sereral limes, till
the second cylinder is about two-thirds filled with liquid carbonic anhydride.

Liquid carbonic anhydride is colourless and Teiy solnble in alcohol, ether, and Tola-
tile oils, but does not mix with water. Specific gravity 0'90 at —20° C. ; 0-88 at
0° C; 0'60 at + 30° G. (Thilorier). Its tension at dimxenttemperatoros is shown
in the following table.

Tenflon In Atmosphere*.

Tention to Atmofplkeres. 1

MarMkA

MaicAm

Temp. C.

Ftnidiy.

and

Temp. C.

FanMiay.

and

Donny.

Doonj.

— 89-40

4*6

—B-OP

88-1

48*8

7-7

88-8

86-6

19-6

80.6

16-4

lO-O

26*1

17-8

16-5

ao-0

91-6

B-6

19*0

15*0

94*7

96*8

98-6

19-9

96*8

970

10-0

97*6

89^

9-4

99-1

8406

Solid CarborUe Anhydride, — -When the liquid anhydride is suddenly relieved fimn
the pressure nnder which alone it can exist, part of it flashes instantly into vapour,
and in so doing produces so great a decree of cold, that the remaining portion of the liquid
solidifies. To obtain the solid anhydride, the receiver containing the liquid is provided
with a tube passing through its side, and reaching nearly to the opposite side^ so that
when the cylinder is set horizontally, this tube dips into the liquid. On opening a
stopcock provided for the purpose, a quantity of the uquid is forced out by the pressure
of the gas above it, and forms a white cloud of the solid anhydride, as it issaes into
the air. By causing this jet of vapour to pass into a cylindrical metal box, having
within it an inclined metal tongue, against which the jet of liqmd and vapour im-
pinges, and is thus made to circulate within the box for some little time Defai« it
finiuly escapes, a considerable quantity of the solid anhydride m^ be odlected in the
form of a white fiooculent mass like snow.

Solid carbonic anhydride may be left eiq>08ed to the air for some lit4le time without
evaporating, because, like all flocculent substances, it conducts heat bnt slowly. Its
tension is 1'14 atmospheres at -99*4^0.; 1*36 at ~77'2<'; 2-28 at ^705^; 3*6 at
-63'2<'; 4*6 at -59-40; 633 at -570 ^Faraday). An air or spirit thermometer
immersed in it sinks to —78^0. Kotwithstanding this low temperature, the solid
substance ma^r be placed on the hand without occasioning a very acute sensation of
cold, because it does not come into dose contact with the skin, being separated from
it by a film of vapour ; but if pessed between the fingers, it poduces a veij paiiiful
sensation, and raises a blister like a bum. By mixing it with ether, its heatHSondnet-
ing power is greatlv increased ; it therefore evaporates more qnit^y, and produces
much more powerful fingorific effects. Mercury poured into it solidifies instantly to a
mass like lead. The cold which it produces is sufiicient to liquefy sulphydxic add,
chlorine, nitrous oxide, and several other gases. The intensitv dT the cold may be still
further increased by placing the mixture under an exhausted receiver. The tempe-
rature then sinks to a degree at which the liquid anhydride is not more volatile than
water at 30^ C, and alcohol assumes the consistence of a thick oil, but does not solidify.
By exposing to this bath, tubes of glass or copper in which gases have been compressed
by a forcing pomp to 40 atmospheres, Faraday, has succeeded in liquefying all the
known gases, coLoeptuig oxygen, hydrogen, nitric oxide, carbonic oxide, and marsh-gas,
and in solidifying a considerable number of them. C^bonic anhydride itself exposed
to this temperature and pressure, is reduced to a vitreous transparent mass.

Carbonic Acid, — Gaseous carbonic anhydride dissolves in about its own volume
of water at ordinarv temperatures, forming a solution of specific gravity 1*0018. It
has a shazp and slightly acid taste, turns the blue colour of htmus to wine-red, partially
neutralises alkalis, and dissolves the carbonates of barium* strontium, calcium, mag-
nesium, &c It, therefore, possesses acid properties, and horn the compositton of the
carbonates, we nay infer that it contains an acid of the composition H'OO'. But this
acid cannot be isolated, as heat, diminished pressure, or congelation immediately re-
solves it into water and carbonic anhydride. In short, carbonic acid as a definite
compound cannot be said to be known.

CARBON : OXIDES. 773

The Tolome of carbonic anhydride dissolved by water at a given temperature, is
nearly tiie same nnder all pressures ; consequently the weight of the gas absorbed in-
Greases in nearly the same proportion as the pressure. This rule must not, however,
be understood as strictly true, for Begnault has shown that the volume of carbonic
anhydride does not vaiy exactly in the inverse ratio of the j^ressure.

Under a given pressure, the volume of gas absorbed diminishes as the temperature
rises. At the bouinff heat, the whole of the gas is driven off; hence carbonic acid
water holding an earwy carbonate in solution deposits it when the liquid is boiled.
This is the cause of the fbrring of kettles, boilers, &&, in which spring or river-water
containing carbonate of caldum dissolved in this manner, is boiled.

The oMfficients of absorption of carbonic anhydride, that is to say the volumes
(reduced to O*^ G. and 0*760 met.) which 1 voL of water absorbs under the pressure of
0*760 met. and at various temperatures, are as follows :

Vol. of Gm
Temp. abtorbed.

(PC. . . . 1-7697

. 1*64S1

1*5126
1-3901
1*2869
11847

•

Vol. ofGM

TMBp.

abMrbed.

12<>C. .

. 11018

. 10321

. 0*9763

. 0*9318

. 0*9013

(Bunsen's Gasometiy. See also the article Gases, Absobftion of.)

Water which has been saturated with carbonic acid under pressure, ^ves it up with
brisk effervescence as soon as the pressure is removed. The various kmds of aerated
water, aoda-^oateTf effervescing lemonade, &c., consist of water impregnated by mecha-
nical pressure with large quantities of carbonic acid, and flavoured with various saline
and oUier ingredients, j^or a description and flffure of Tylor^s soda-water machine,
see Ur^t ^ietumary oj Arts, Manufactwres and Mines, iv. 728.) Champagne and
other effervescing wines and bottled beer likewise owe their sparkling properties to
the presence of this gas ; but in these liquids the oarbonic acid is product by the
fermentation itself the wine or beer being bottled before the fermentation is complete,
whereby a conaidezable quantity of the gas, which would otherwise escape into the air,
is retained.

For the behaviour of Hqneous carbonic add to bases, see Cabbonatss.

Pbotozidb ov Oabbov. Cabbonio Oxzdb.« CO. — This compound, which is
known only in the gaseous state, was discovered towards the end of the last century by
Lassonne and by raesUey ; but its true nature was first recognised some years after-
wards by Woodhouse (GKlberf s Annalen, iz. 423). It is produced : 1. By the oxi-
dation A carbon at vezy high temperatures,when the supply of oxygen is not sufficient
for the complete conversion of the carbon into carbonic anhydride (p. 763). — 2. When
carbonic anhydride is exposed to a red heat in contact with hydrogen, carbon, metals,
or other bodies which can abstract part of the oxygen : hence it is always produced in
charcoal or coke fires, when the draught of air has to'pass upwards through a con-
siderable mass of red-hot fuel, and is uie cause of the blue flame almost always seen
on the top of such flres. — 3. It is also formed, together with hydrogen and carbonic
anhvdride, when vapour of water is passed over rM-hot coke or charcoal. A sample
of the gaseous mixture thus formed was found by Bunsen to contain 56*03 volumes per
cent, of hydrogen, 29*15 carbonic oxide, 14*65 carbonic anhydride, and 0*17 carburetted
hydrogen. — 4. Caarbonic oxide is produced, either alone or together with carbonic
anhydride, in the reduction of metaUic oxides by carbon at a strong red heat The
gas evolved firom iron blast-Aimaces contains firom 25 to 32 per cent., that from copper-
refining fiimaoes from 13 to 19 per cent, carbonic oxide (Bunsen, Pogg. Ann. xlvL
193; 1. 81).— 5. In the dry distillation of many organic compoundis. — 6. In the de*
composition of oxalic acid and formic acid by strong sulphuric acid :

C«H«0* - CO + CO* + H*0
Oxalie
add.

CH*0« ■» CO + H?0
Fonnie
add.

7. In tbe decomposition of erystallised fenocyanide of potassium by sulphuric acid
(Fownes):

2K«FeC»N«.3H«0 + 6BPS0« + 3IP0 = 6C0 + 3(NH*)«S0* + 2K»S0« + Fe«0«

OrfiUllUed ferro- Solphaleof Sulphate Ferroua

cyanide of annnontum. ofpotat- lulphato^

poiaiaiimu ifam.

3d 3

774 CARBON: OXYCHLORIDE.

Preparation. — 1. By heating to redness in a gon-barrel fitted with a gas-delire^
tube, a mixture of oxide of iron, zino, lead, or copper with eharooal or graphite ; or of
an alkaline or earthy carbonate (chalk for examfuie) with graphite, chaiooal, or iron
filings ; or by passing carbonic anhydride repeatedly oyer red-hot iron or eharooal.
By either of these methods, carbonic oxide is obtained mixed with carlxmic anhydride
from which it may be freed by passing the gas through milk of lime or strong potash ;
it may then be collected oyer water. The charcoal used must be pfrerionaly wul ignited
to free it from moisture and absorbed gases. — 2. By heating in a flaak a mixture of
oxalic acid, or an oxakte, or a formate, with excess of strong sulphuric add, and remor-
ing the carbonic anhydride eToWed when oxalic acid or an oxalate is used, as beforsL —
3. When crystallised ferrocyanide of potassium, in the state of powder, is heated in a
flask with eight or ten times its yolume of sulphuric acid, carbonie oxide is eroWed
quite free from carbonic anhydride, and mixed only with a small quantity of Taponr
of hydrocyanic add, resulting from another reaction which takes place at the same
time, if the quantity of wat^ present is more than suffident for the aboTe deeompod-
tion (see Fbbboctanidbs). . This is the most convenient mode of preparing carbonie
oxide. Care must, however, be taken not to raise the heat higher than is neoessaxr
for the complete liquefaction of the mixture ; for at that point the. evolution of eaibome
oxide ceases, and if the heating be continued, the excess of sulphnrie add acts on the
ferrous sulphate produped, converting it into ferric sulphate^ and being itself xedneed
to sulphurous annydride, which escapes as gas and mixes with the canxmic oxide.

Fropertiea. — Carbonic oxide is a colourless gas of specific gravity 0*96799 (Wrede) ;
its molecule CO therefore occupies two volumes :

^^ ^ ^^ X 00693 c 14 X 00693 - 0*9702.

It is perfectly neutral to vegetable colours, and very spaiinpfly soluble in water,
which, according to Bunsen, dissolves only 0*024 or about j^ of its bulk at 16^ C It
is a vexy poisonous gas, acting chiefly on the nervous system, causing giddiness wlien
inhaled, sometimes also acute pain in various parts of the body, and after a while
complete asphyxia. According to Leblanc (Ann. Ch. Phys. [3] v. 223), it is to
this gas that the suffocating quality of air in which charcoal has beoi burat is ehieflj
due.

Carbonic oxide does not support the combustion of bodies which bum in oxygen,
but in contact with the air it takes fire on the approach of a burning body, and bams
with a blue fiame, producing carbonic anhydride. Mixed with excess of oxygen, it
may be ex{)loded bv the electric spark, 2 vols, of it then imiting with 1 voL oxygen
ana produdne 2 voL carbonic anhydride CO^ Now as 2 vols. CO* contain 2 vole,
oxygen, it fouows that 1 voL oxygen must have been derived from the carbonie oxide.
Hence carbonic oxide contains half its own volume of oxygen. Now the weight of
2 vols, carbonic oxide, compared with hydrogen, is 28, wmch, diminished by 16, the
weight of 1 voL oxyjgen, leaves 1 2 for the weight of 1 atom of carbon. Hence in eaibonie
oxide the same weight of carbon is united with exactly half as much oi^gen as in
carbonic anhydride^

The combustion of carbonic oxide may be brought about by contact with pUUimaL
A wire or foil of the metal requires to be heated to 300° C. to induce the combustion :
spongy i^atinum acts at ordinaiy temperatures, without becoming aendbly heated ;
but platinum-black introduced into the mixture of carbonic oxide and oxygen becomes
red-hot and produces explodon.

Carbonic oxide reduces certain metallic oxides at a red heat, vis. the oxides of copper,
lead, tin, iron, &c. It plays indeed an important part in the smelting of many metals,
especially of iron.

Carbonic oxide is rapidly absorbed by a solution of cuprou$ chloride in hydrodilorie
add, also by ammonical solutions of cuprous salts. This reaction affords an excellent
method of removing carbonic oxide from a ^eous mixture (p. 283), It reduces
gold from the neutral solution of its chloride without the aid of heat.

Carbonic oxide unites directly with chlorine^ forming oxychloride of carbon or phos-
gene gas ; also with potaseitim, (See Potassiuic.)

It is absorbed by hot hydrate of potaseiumj yielding formate of potassinm,
CO + KHO « CHKO«. (Berth elot, Ann. Ch. Pharm. xcviL 126.)

aaJUBOV, OXTCS&OBZBB or, COa* or Chloride of Carbon^ (COy.CP.
Chloroearbonio oxide, Chlorocarbonic acid. Phosgene. — ^This compound was disccrveted
by J. Davy (Phil. Trans. 1812, p. 144), who obtajmed it bve^^sing to the sun's ravs^
a mixture of equal volumes of chlorine and carbonic oxide. The mixture eraduauy
becomes colourless and contracts to half its original volume. The same actum takes

CARBON: SULPHIDES. 775

place slowly in dififhwd daylight ; none whaterer in the dark. The name phosgene
originallj given to the gas signifies a compound formed by light

Oiq^tBhloride of carlwn may be more conTeniently prep»ed by peasing carbonie
oxide into boiling pentachloride of antimony, that oomponnd being at the same time
lednoed to trichlonde. The gas mnst be leoeiTed over mercury, as water decomposes
it (Hofmann, Ann. Ch. Fh^m. Izz. 189). It is likewise produced when carbonic
oxide is passed over red-hot chloride of leaid or chloride of silver, and in the following
deooinpositions of oij^anic bodies :

a. By the dry distillAtion of trichloraeetates:

o»a«Mo* - coa« + co + Ma

h. By the dry distillation of certain perchlorinated methylic ethers, e. 0. of the/or*
iikrfe,C«(31*0« B 2C0C1« ; and of the oxidate, C*C1*0* - COa« + 800.

e. By the action of a lazge excess of strong snlphuzio add on the so-called sulphite
of tetrachloride of carbon (p. 766) :

Ca*SO« + HK) - COa« + 2HC1 + 80«.

Oxychloride of carbon is a colourless gas having a suflbcating and tear-exdting
odour. Its spedflc gravity is 3'6808 (Davy), 3*4249 (Thomson); calculated for a
condensation to two volumes, it is

12 + 16 + 2 . 86-5 ^ ^^^« „ .«^
5 X 0-0693 — 8-430.

Its refracting power is 8-936. It reddens moistened litmus-paper ; does not fbme
in the air.

Oxychloride of carbon is decomposed by tcaterf yielding carbonic anhydride and
hydrochloric acid :

COa« + H»0 « C0« + 2HC1.

When mixed with an equal volume of hydrogen and half its volume of oxygen, it
explodes violently on the passage of an electric spark, vielding the same [ur&ucts.
Mixed with oxygoi or hvdrogen alone, it is not exploded \y the electric sparlL

Araenio and antimony heated in the gas take up the chlonne^ and leave carbonic oxide
equal in volume to the original gas. Many metallic oxides, oxide of rine^ for example,
decompose it with the aid of heat, forming a diloride of the metal and carbonic an-
hydride equal in volume to the original gas. IHoxide of antimony produces tri-
chloride and pentoxide or tetroxide of antimony, leaving carbonic oxije.

By aioohoU it is converted into ddorocarbomc ethersi e. ff, :

With afMnoniaaaSf oxydiloride of carbon produces carbamide (p^ 752) and chloride
of ammonium, yfiih^henvlamine and many other organic bases, it reacts in like man-
ner, forming substitution-derivatives of carbamide.

OAMB0»> &U1»9WI!B!EM OV. Only one of these compounds is known with
certainty, viz. the disulphide corresponding to carbonic anhvdnde. The formation of
a proto8u^>hide, analogous to carbonic oxide, was announceo, in 1867* by Baudrimont^
but his statements have not been confirmed. (See page 777.)

DisuLFKiDB OF Oabbok. OS*. Siwlpktde of Carbon, Sulpkocarhomo AeicL
(Lampadius, Qehlen's N. allg. Joum.d. Ghem. ii. 192; 016ment and Besormes,
Ann. Ghim. idii 121; Yauquelin and Bobiquet, ibid, IxL 145; Berthollet,
Th^nard, and Yauquelin, ibid. Irrii. 252; Berzelius andMarcet, Schw. J. ix.
284 ; Berzelius, Gilb. Ann. xlviii. 177; Pogg. Ann. vL 144; Zeiss, Schw. J. xxvi.
1; xll 98, 170; xliii. 160; Couerbe, Ann. CE Phys. [2] Ld. 225; Eolbe, Ann. Ch.
Pharm. xlv. 53 ; xlix. 143; Pelouze and Fr^my, Traiude CMmie, 4-« ^d. i. 923).—
This compound which was discovered by Lampadius in 1796, is produced by the
direct combination of sulphur and carbon at high temperatures, and in the decomposi-
tion of many oi]^[anic compounds. Sulphur and carbon do not combine when simply
heated together in the sohd state, because the sulphur volatilises before the requisite
temperatue is attained; but if charcoal be heated to redness and sulphur- vapour
passed over it, the carbon bums in that vapour, forming OS*.

For preparing small <^uantities of the disulphide, a porcelain tube is filled with frag-
ments of charcoal, and inserted in an inclined position through a furnace having holes
in its sides. The upper extremity of the tube is closed with a cork, and the lower is
connected by a bent glass tube, with a bottle containing water, the lower end of the bent
tube passing through the cork and dipping just below the surface of the water. WhcQ

3d 4

776 CARBON: SULPfflDES.

the charooal is red-hot, the upper end of the tabe is opened and a piece of sn^nr pnt
in ; the sulphur melts and runs down to the lower part of the tube, where it TolatOisea
and combines with the carbon, forming disulphide of carbon, which pniwcs off in
vapour and condenses in the liquid form at the bottom of the water. For larger qpian-
tities, a tubulated earthen retoit is used, having a porcelain tube passing throng^ tiie
tubiUus, and reaching nearly to the bottom. Tha retort is filled with ciiareoal, heated to
redness in a fiimaee, and bits of sulphur dropt in thiongh the tube. The neck of the
retort is connected with a condensing tube kept cold by a stream of water, aodpassiiw
into a receiver containing cold water as above deseribed. The sulphide of carbon wfaic£
collects at the bottom of the water is not pore, but contains excess of solphur. It is
purified by distillation at the heat of the water-bath, the sulphide of caxbon then
volatilising and the sulphur remaining behind.

Properties. — ^Disulphide of carbon is a colourless, very mobile^ strongly refracting
liquid, having a &int and peculiarly unpleasant odour. Its refracting power is 1*646.
Specific sravity 1*293 at 0^ C, and 1*271 at \6^, Boils at 46-6^ under ordinaiT pres-
sure, and evaporates quickly at ordinary temperatures, producing great cold. Vapoor-

/12 + 2 32 \

density » 2*67, corresponding to 2 vols, f ^ — x 0*0628 » 2-681. It is inso-
luble in footer y to which, however, it imparts its odout. MwhU and ether mix with it
in all proportions. It dissolves euiphwr, phoaphortu, and iodine; sulphur and phoe-
phorus separate from it by spontaneous evaporation in well defined dystala* It dis-
solves camphor and mixes easilv with oi2f , both fixed and volatile.

Decompoeitions. — 1. Disulphide of carbon is veiy inflammable, and boms with a
blue flame, producing sulphurous and carbonic anhydrides. — 2. The vapour pasnd over
various TneiaUio oxides at a red heat, yields the same gaseous products, together with a
metallic sulphide ; the sulphides thus formed are cenerally aystaUised, and resemUe
those found in nature. Sulphide of carbon is indeed one of the most powoftl sul-
phurising agents known, aifording the means of producing several metaUie snlphidea
not otherwise obtainable (Fr^my). It likewise converts oxides into sul^dee when
heated with them in sealed tubes ; with water at 150^ C. it ^Ids earbome anhydride
and sulphvdric add (Schlagdenhauffen, J. Phann. [8^ xxix. 401). — 8. The Tapaur
is stronelv attacked by nitric aeid^ yielding sulphuric acid and nitzoos rapoara,
— 4. Sulphide of carbon heated with chloratee or hypochlorites reduces them to
chlorides, with evolution of carbonie anhydride and deposition of sulphur. — 6, Heated
with aqueous iodic add in a sealed tube, it yields hydriodic add^ together with fripe^
iodine and a deposit of sulphur, also sulphuric add, sulphydrio add, and carbonie an*
hydride. Two reactions appear to go on at once, vis. :

2Hio« + cs« « p + co« + BPso* + a

2HI0* + 2CS« + 2H«0 - 2C0« •!• 2HI + IPBO* + WB + B^.

The liquid is at first coloured violet by the free iodine, but on increasing the heat, the
colour disappears, in consequence of the action of the sulpfi^dric add on the iodine,
which produces hydriodic add and firee sulphur, the latter imparting a straw-ydlow
colour to the liquid (Pelouze and Fr^my). — 6. Bromio acid acts in like manner. —
7. Man^ metals decompose disulphide of carbon at a red-heat, taking up the sah»hnr
and setting the carbon free. — 8. A mixture of sulphide of carbon vapour and sw^J^
dric acid gas passed over red-hot copper yields sulphide of copper and marsh-gaa
(Berthelot):

CJS« + 2H« + Cu« = 4Cu«S + CH«.

9. With nascent hydrogen^ sulphide of carbon yidds sulphvdric add, a orystsDised
body, GH^S, and an oUy substance not yet examined (Girard, Compt. rend. xliiL 39).
— 10. Diy chlorine converts it at a red heat into tetradiloride of carbon ; at ordinaiy
temperatures, into sulphoehloride of carbon, CSCl'; but with moist dilanne it yields
trichloromethylsulphurous add (the so-called sulphite of tetrachloride of carbon,
Ca^SO* - SO'.Ca« (Kolbe).— ll. Bromine and sulphide of carbon do not act
upon each other when pused through a red-hot tube. — 12. Tbit fixed causUe alkalis
gradually dissolve disulphide of carbon, forming a brown solution, which is a mixtoie
of carbonate and sulphocarbonate of the alkaU-metal (Zeise) :

8CS« + 3K«0 - KKIO* + 2K«CS».

13. With alcoholic potashit yields carbonate and ethyl-oxysulphocarbonate (xanthate)
of potassium, which forms a yellow predpitate with copper-saUs (Zeise) :

CS« + C*H».KO - iS2C|s«.

C«H»KI

An aqueous or alcoholic solution of caustic potash, boiled with disulphide of carbon,
forms with lead-salts a block precipitate of sulphide of lead, whidi affords a vciy deli-

CARBON: SULPHOCHLORIDE. 777

eate test for sulphide of carbon. It is instantly produced on dropping a dilute solntion
of that oomponnd into a boiling solution of nitrate of lead containing potaah, a distinct
coloration being obtained, even with a liquid containing only a drop of sulphide of
carbon in a quart of water. — 14. With a^[ueou» ammoma^ it forms sul^ocarbonate and
solphocyanate of ammonium, without any carbonate (Zeise) :

2CS» + 4NH» - (ira*)»CS» + NH*.CNS.

15. With a saturated solution of arnmowUp^faa in anhydrous aleohol, it yields the same
products, together with sulphoearbamate ox ammonium, produced by the simple union
of ammonia with the disulphide (Z eise) :

cs« + 2NH" - (nhkS) jyH*.a

16. With irieihylphMphine it unites directly, forming a compound P(C*EP)*.CS*
which crystallises in splendid ruby-coloured prisms. The reaction affords an ex-
tremely delicate test for the presence of either of the constituent substances, and is es-
pecially applicable to the detection of sulphide of carbon in coal-gas. When a stream of
the gas, piuified from sulphuretted hydrogen in the usual mannef, is passed through a
solution of triethylphospmne in ether, contained in a bulb apparatus, a red colour soon
i^ppears in the liqmd, and when sufficient gas has been passed through the liquid to
evaporate the ether, the bulb-apparatus is seen to be lined with a network of the red
czystals. (A^ W. Hofmann. Ann. Gh. Pharm. cxr. 296.)

The sulphocarbonates MH^S*, or M'S.CS', bear to msulphide of carbon the same
relation that the carbonates M'CO* bear to carbonic anhydride. Moreoyer by treating
snlphoearbonate of ammonium with dilute sulphuric orhydrodiloric add, an oily, yeiy
add liquid is predpitated, consisting of sulphocarbonic add, H^CS".

Pjiotosx7lphidb of Cabbon. CS. — Ab already observed, it is doubtful whether
this compound, the analogue of carbonic oxide, has yet been obtained, though there
can be no doubt as to the possibility of its existence. Baudrimont (Compt. rend,
xliv. 1000), states that it is obtained tolerably pure by passing the vapour of the di-
sulphide over red-hot spongy platinum or pumice, and washing the resulting gas with
solutions of acetate of lead and cuprous chloride, to free it from sulphydric add and
carbonic oxide, resulting from the action of air and moisture remaining in the
materials. The gas thus obtained is described as colourless, smelling somewhat like
the disulphide, not liqueflable at the temperature of a mixture of ice and salt ; soluble
in its own bulk of water ; decomposed by lime-water into sulphide of caldum, and a
volume of carbonic oxide equal to its own : Ca'O + GS ■■ Ca^ + CO ; and yielding
when exploded with oxygen, equal volumes of CO' and SO*.

Baudnmont likewise obtained the protosulphide, but mixed with sulphydric add and
carbonic oxide, bypassing the vapour of the disulphide over red-hot charcoal ; by the
action of snlphydnc add on carbonic oxide at a rod heat (CO + H*S » WO + CS),
and by several other processes.

Flayfair (Chem. Soc. Qu. X xiiL 248) endeavoured to prepare the nrotosulphide
by passing the vapour of the disulphide over red-hot pumice, but obtained nothing but
a mixture of carbonic anhydride, carbonic oxide, sulphydric add, and nitrogen, satu-
rated with vapour of disuli>hide of carbon ; he observed no deposition of sulphur in the
red-hot tube, though Baudrimont states that it choked up the exit-tube of his apparatus.
Flay&ir attributes the formation of these gases to air and moisture retained by the
pumice, thou^ it had been previously ignited, or introduced into the tube together
with the disuphide. He is of opinion timt Baudrimont's gas, which yielded bv explo-
sion wil^ oxygen, equal volumes of SO* and CO*, was a mixture of equal volumes of
CO and va^ur of CS*, which at common temperatures, and under the diminished
pressure existing in the eudiometer, would have suffident tension to diffiise itself in
vapour through tiie carbonic oxide.

In &ce of tiiese contradictory results, the question as to the actual formation of pro-
tosulphide of carbon must for uie present be conddered as undedded.

OASSOV, SUlimoOBZiOaiBH OV. CSa*.-~This compound, the analogue
of phosgene, was discovered by Kolbe (Ann. Ch. Pharm. xlv. 53), and is produced:
1. By the action of dry chlorine on disulphide of carbon at ordinaiy temperatures,
chlorideof sulphur being formed at the same time: CS* + Cl^ »SC1*+CSC1*. A few
grammes of the disulphiae are left exposed for a few days to the action of perfectly drj
chlorine in a closed flask, dther in the dark or lu sunshine ; the resultinff liquid is
digested with water to decompose the chloride of sulphur, and the remaining oily
liquid is freed from the add products thereby formed by repeated distillation with
water and a small quantity of magnesia. It is essential to the production of this com-
pound, that the materials be perf^tly diy, as if moisture is present, another compound,
tiiehloro-methyl-sulphurous add is obtained (p. 776). At a red heat» % different

778 CABBONATES.

action takes plaee, and tetrachloride of carbon is ptodoeed. — % By pasaing a mixtiuv.
of sulphydric acid and yaponr of tetrachloride of carbon through a tabe kept at a
moderate red heat: 'CCi* + H>S « 2HC1 + CSGl^.

Sulphochloride of carbon is a yellow liquid, not miscible irith 'water, haTzog a
pecoliar and powerful odonr, Teiy irritating to the eyes. Specific geaTitj l-4d.
Boiling point 70^ G. These numbers probably require correction, aa it is mj aifScult
to obtain the compound free from sulpnide of carbon. It is not decomposed fay water
or adds, not eren by fuming nitric add. Caustic potash decomposes it slowly, form-
ing carbonate and sulphide of potasdum, and tetradiloride of carbon :

2CSC1* + 3K«0 = K«CO» + 2K«S + CCl\

CAX80VATBB. The carbonat.e6 form a numerous and important dass of salts,
many of which occur as natural minerals. They are usually diTided into normal^ batie^
and aeid carbonates, the normal or neutral salts having the compodtion

M»CO> - MK).CO« = ^^^"|0* [orMO.CO^.

The bade carbonates, however, all contain water, and by regarding the whole or part
of this water (or hydrogen) as basic, the carbonates, like the borates, phosphates, and

C )

silicates, may be^divided into ortho-carbonates, HK/0* ■■ jirJOSandmetaear-

bonates, MK)0',--or more generally orthocarbonates «> H'H^-*(>0^, and metaear-
bonates » M'H*^*O0^, the latter induding the salts usually r^;axded as nentral
carbonates. Nearly all the predpitates obtained by adding a solution of an alkaline
carbonate to a salt of a heayy metal, contain water, and may be represented by one or
other of these formulse. It is difficult to say whether the ormo- or the meta-carbonates
are the more numerous ; but the carbonates of the stronger bases, Tiz. the alkali-metala
and alkaline-earth metals, are certainly meta-carbonates. Only a few add carbonates
are known as definite salts, yiz. those of potaadum, sodium, and ammonium, and these
are metacarbonates containing hydrogen, e, g. monopotasaic metaearbonate^ or diadd
carbonate of potassium, (E^H^CO*.

Carbonates are formed by tne action of carbonic add, or the joint action of water and
carbonic anhydride, on metallic oxides or hydrates, not in any case hj the union of
carbonic anhydride with an oxide without the interrention of water. £ime-water, or
milk of lime, absorbs carbonic anhydride rapidly, forming carbonate of «ilfniiTn ; bat
perfectly dry* carbonic anhydride may be passed oyer anhydrous lime without ab-
sorption. £yen dry hydrate of potaadum, KHO, absorbs carbonic anhydride but
slowly, and soon becomes covered with acrast of add carbonate of potaadum (KHO +
CO' s» KHCO'), which protects the rest from alteration ; but the moist hydrate, or
the aqueous solution, ab«>rbs it with the greatest avidity; similarly with other bases.
The carbonates of the earth-metals proper and heavy metals are most easOy obtained
by predpitating a soluble salt of the metal with an alkaline carbonate; but the pre-
dpitate, as already observed, almost always contains water, and very rardy haa the
composition of an anhydrous metacarbonate M'CO*. The sesqnioxides, alumina,
ferric oxide, chromic oxide, uranic oxide, &c, do not absorb carbonic anhydride even
when moist, and their solutions, when mixed with alkaline carbonates, yidd predpitates^
not of carbonates, but of hydrates. Hetals like zinc and iron, which readily replace
hydrogen in acid solutions, ma^r be converted into carbonates by simply immersing
them m water containing carbonic add.

Carbonates are also formed in the decompodtion by heat of organic salts of the
stronger bases, viz. of the alkali-metals and of the alkaline-earth metals. Oxalates are
resolved into carbonates and carbonic oxide, without separation of carbon :

CMK)* = CM«0« + CO

formates into carbonates, with evolution of carbonic oxide and hydrogen, and alight
separation of carbon :

2CHM0* - CMW + CO + H».

The salts of most other organic adds yield a conddemble quantity of fbee earixm
beddes combustible gaBos ; acetates and we salts of other fttty adds, and a few others^
are resolved by dry distillation into carbonates and acetones ^ip. 81, 82).

The carbonates of ammonium, potaadum, and sodium are easily soluble in water;
carbonate of lithium dissolves in about 100 pts. of water ; the carbonates of all other
metals are insoluble, or nearly so, in water; but all are dightiy soluble in water
containing free carbonic add. Add carbonates are doubtless formed in this case ;
but none of these, excepting the add carbonates of the alkali-metals, ean be ob-
tained in the solid state, as the solutions, when boiled or evaporated, give off car-
bonic anhydride and deposit neutral carbonate. All metallic carbonates, excepting

CARBONATES. 779

carbonate of ammonium, are insolnble in alooboL GarbonMeB of organic alkalis are
fitf the moat part soluble in water and in alcohol ; carbonates of alcohol-radicles, in-
soluble in -water, soluble in alcohoL

Most carbonates are easily decomposed by heat. The carbonates of the heavy metals
are all decomposed at a low red heat, giving off carbonic anhydride^ and lesring a
residuB of metal or of oxide. The carbonates of the earth-metals proper, and of calcium
and strontium, require a stronger red heat to decompose them ; carbonate of bariiim is
decomposed only at a white heat ; and the carbonates of the alkali-metals, when diy,
resist the action of the strongest heat, excepting when a current of diy air oAther gas
is passed over them ; in that case carbonate of sodium giyes up a small quantity of
carbonic anhydride, and carbonate of lithium a considerable quantity. (H. Bose.)

Nearly aU carbonates are more or lees decomposed by water, with the aid of heat,
those of the weaker bases even at ordinazy tmperatures, so that precipitated car-
bonates are rezy apt to undergo partial decomposition during washing. Even the
carbonates of buium, potassium, sodium, and magnesium are conxerted mto hydrates
when heated to redness in a stream of aqueous vapour ; partially also in a stream of
moist air or hydrogen gas : the carbonates of barium and potassium do not suffer any.
decomposition in a current of dry air or hydrogen. (H. Bose, Pogg. Ann. Ixxxv. 99,
279 ; Jahresber. d. Chem. 1852, p. 309.)

Carbonates are decomposed, with evolution of carbonic anhydride, by nearly all
acids, even at ordinary temperatures, and at a red heat by many adds whose salts are
themselves decomposed at ordinary temperatures b^ carbonic acid, e,g. by boric, silicic,
and several metaUic adds. The effervescence which accompanies the decompodtion
affords a rea^ indication of the jpresenoe of a carbonate. Any of the stronger acids may
be used to efirect the decompodtion, but, generally speaking, hydrochloric or nitric add
is preferable to sulphuric add, be<»use Uie latter often forms insoluble or sparingly
soluble saltan the presence of which interferes with the reaction. If the carlx>nate is
in solution, the liquid should be concentrated before adding the add, as in a very
dilute liquid the carbonic add may remain dissolved instead of escaping as gas. The
decomposing add must also be added in excess, otherwise an add carbonate of the
alkali-metal will be formed, and no effervescence will be observed. If tiie substance
to be examined is a mineral, it must be finely pulverised, and the powder should be
soaked in water before adding the add ; otherwise the escape of air-bubbles might be
mistaken for an evolution of carbonic uihydride. Many other volatile adds produce
effervescence when eliminated from these compounds, e^g. hydrochloric, hyoriodic,
sulphurous, sulphydric acid, &c ; but they ma^ all be distinguished from carbonio
add by their colour or their odour, also by passing the evolved gas into lime*water or
baryta-water, and proceeding as described at page 768.

Ca.bboni.tb of AI.UXINIX7X (?) Itis doubtAil whether such a compound exists.
Saussure stated long ago that alkaline carbonates throw down from solutions of alu-
minium, a compound of hydrate of aluminium with a smaU quantity of the alkaline
carbonate, ana that the hydrate is partially soluble in aqueous carbonic add, but is
completely separated on warming the solution or exposing it to the air (G-m. iii. 809).
Other chemists have, however, (Stained different results. According to Muspratt
(Chem. Soc Qu. J. il 206), the predpitate formed by alkaline carbonates consists of
8A1<0«.200« + 16HK). Langlois (Ann. Ch. Phys. [3] xlviiL 602) found 8A1^0>.
3C0> -I- iOH^O ; and Wallace (Chem. Oaz. 1868^ 410) gives, as the compodtion of
the predpitate, 8A1«0^2C0< + 9H*0. H. Bose, on the contrary (Pogg. Ann. xli.
462), states that the predpitate formed by carbonate of ammonixmi is a compound of
trihydrate of alumimum with carbonate of ammonium, AlfH'O' + KH^H.CO*, the
ammonia-salt not being removable by washing. From experiments recently made in
Dr. Muspratt^s laboratory by Mr. James Barratt (Chem. News, L 110), it appears
that the predpitate formed oy carbonate of sodium in a solution of chloride of alu-
minium, after being washed and dried, then triturated with water, again washed, and
dried over sulphuric add, consists of pure hydrate of aluminium.

CA.BBOKATB OF Alltl. See CABBomo Ethebs.

CABB0iri.TB8 OF AxKONiux. Theso salts havo already been described (p. 190).
They are all metacarbonates, and may be formulated as follows :

Neutral carbonate, (NH*)«O.CO« « (|^)i|o»

Add carbonate, ^%.C0« « NHVeN'

Seiquicarbonate, 2(NH«)K).8CO« + 3aq. « /^jjtiy^^J 0« + aq

780 CARBONATES.

CASBOVA.TB OF AxTX^ See Gjlrbohic Ethbbs.

Gabbovatb or Babiuil BaKX)* « Ba*0.00*. — This salt ocean abimdsBtlj
in natnie as WttheriU^ a mineral which frequently aeoompanies lead-ciesL It em'
tallisee in the trimetnc aystem, iaomorphoQslj with azragonite, the crfBtala being
frequently prismatLe^from predominance of the tacea oo P, oo I* oo, and t oo. The eom-
bination P.2]^oo.oo]^ao.aoP, is also common, forming a aix-eided prism with
pyramidal snmmits. Batio of axea^ a: b: e =^ 0*6960 : 1 : 0-7418. Inclination ot
faces: ooP : ooP «6lo 30'; iPoo : t»«71° 47'; 2]^ oo : 2P od « 110° 42*. deayage
imperfec^yarallel to oo P oo, oo P, and P oo (Kopp). It ooenrs also in g^bnlar, tuberose,
and botiyoidal forms ; stractnze either colnmnar or grannlar ; also amor{^ns. I^ecifie
graTitj a 4*29 to 4*36. Hardness « 3 to 8*76. lAstze Titieons, inclining to resinoas
on fractured sorftoes. CSolonr white, or often yeUowish or greyish. Slzoik white.
Subtrancparent to translnoent. Fractoie nneven. Brittle, ll^therite is found on
Alston Moor in Comberbmd, and in splendid crystals at Fallowfield in Karthnmbep>
land. It oocnm also in many places on the continent of Enrope^ in the Altai, near
Coquimbo, Chili, &c It is sometimes fofond altered to hea^ spar by the action of
soluble sulphates.

Carbonate of barium is ra^dly formed when baryta, either in the anlr^droas state,
or in crystals, or in solution, is exposed to the air, and is easily prepared by predpi*
tating an aqueous solution of the chloride or nitrate with carbonate of ammonium, or
a solution of the sulphide with carbonate of sodium ; the salt obtained by this last
method is liable to he contaminated with a sulphur-con^und. It may aim be pre-
pared in an impure state by igniting in a crucible a mixture of 10 pts. of natiTe
sulphate of barium, 2 pts. of charcoal, and 6 pts. of carbonate of potassium (^eail-ash).
A mixture of solphide of potassium and carbonate of barium is then obtained, from
which the sulphide of potassium may be extracted by water. The impure carbonate
thus produced may be used for the preparation of other barium-salts^ but the salts thus
obtained will contain iron.

Carbonate of barium artificially prepared is a soft white powder. It is poisonous,
and is used as ralr-bane. It is yezy slightly soluble in water, about 1 pt in 4000,
rather more (in 688 pts. according to Laasai^e) in water saturated with carbonic acid.
It dissolves easily, even in the cdd, in chloride, nitrate, and succinate of ammonium,
and when boiled with chloride of ammonium, it is completely decomposed, yielding
carbonate of ammonium and chloride of barium. When shaken up wim aqueous sul-
phate of potassium or sodium, it yields sulphate of barium and carbonate of the alkaH-
metaL it bears a strong red heat without decomposition ; but at the heat of a forge-
fire it gives off carbonic anhydride and leaves baryta. The decomposition is greatly
facilitated by the addition of charcoaL Carbonate of barium is decomposed by vuwur
of water at a red heat, and very easily if mixed with an equal weight of cha& or
slaked lime.

An acid carbonate, 2BaK).3CO* or 2Ba*C0'.G0*, was said hj Boussingault (Ann.
Ch. Phys. [2] rrix. 280) to be obtained by precipitating chloride of barium with aes-
quicarbonate of sodium. BL Bose, on the other nand, by mixing chloride of barium
with diacid carbonate of sodium or potassium, obtained nothing but neutral carbonate
of barium, and is of opinion that acid carbonates of barium cannot exist excepting in
solution.

Cabbona-TB of Bismuth. — ^When nitrate of biBmuth is dropt into a solution of
alkaline carbonate, a white precipitate is formed, oonsistingof Bi'O'.CO* (Berselius).
The precipitate formed with alkaline carbonates contains Bi'O'.CO* + (aq., the water
escaping at 100^ C. (Lef ort)

Cabbokatb of Cadxium, CdK/O", occurs in small quantity, associated with
native carbonate of zinc Cadmium-salts yield with carbonate of ammonium, a white
precipitate, containing CdKX)* -i- aq., which gives off its water between 80^ and 120^ C. ;
at a higher temperature, carbonic imhydride goes of^ and brown oxide of cadmium ia
left, wmch when exposed to the air is gradually reconverted into carbonate (Lef ort»
J. Pharm. [3] xiL 406). According to S. Bose (Pogg. Ann. Ixxxv. 304), the preci-
pitates formed by alkaline carbonates in solutions dt CMmium, contain very little water,
and approach very nearly to the formula CdKX)*. Moist hydrate of <*^^^m^«fn absorbs
carbomc add from the air, and at 300*^ gives off aU its water, and is converted into
2Cd»0.CdH}0«, or Cd«O.Cd*CO*.

Cabbonatbs of Calcium. — The metacarbonaiff Ca*CO* « CaK).CO',oeeunmost
abundantly in all parts of the world, in the forms of calcspar, marble, limestone of various
kinds, and chalk ; also in e^-shells and the shells of molluscs, and, together with phos-
phate of calcium, in bones. It is formed when lime, either anhydrous or hydrated, is
exposed to the air in its ordinair state of moisture, but not bv the action of carbonie
anhydride on anhydrous lime. It may be obtained pure by dissolving calcined oyster *

CARBONATES. 781

sbeUfl, chalk, or marble, in h jdrociUoric add, adding ammonia or milk of lime to pre*
dpitate alumina, oxide of iron, and earthy phosphates, then filtering, predpitating the
hot filtrate with carbonate of amTnoninm, waahmg thoroughly, and diying at a heat
abort of redness.

Carbonate of caldmn is dimorphons, qystalh'mng in the hexagonal system as ealcspar
(p. 721), and in the trimetric system as arragomte (p. 358). The spedfic grayitf of
the former Taries from 2-6987 to 2*76 ; of the hitter, generally from 2*92 to 3*28. The
artificially prepared salt is a white powder, consisting of small oystals, which usually
take the fonn of airaeomte when predpitated from hot solntions^ and ofcalcspar when
predpitated from cold eolations, especially if dilute. The microscopic aystals of ana-
gonite gradually change into rhombohedrona of ealcspar if left for some time under the
cold liquid (p. 359). The precipitate formed in hot sdhitions, assumes the dystalline
character at once ; that from cold solutions is amoiphous at first) and gradually becomes
ciyBtallin&

Carbonate of caldum is tasteless, and has a slight alkaline reaction to test-paper.
It ia yezy sparingly soluble in water, requiring, according to Fresenius (Ann. Ch.
Fharm. hx. 117), 88*34 pts. of boiling and 10,601 pt& of cold water to dissolye it; the
solution is sli^tly alkaune. Water containing frae carbonic add dissolyes it much
more firedy. When recently predpitated, it dissolTes easily in aqueous carbonate, sul-
phate, hydrodilarate, nitrate, or succinate of ammonium : out when it has assumed the
crystalline form by long standing, it dissolyes but sparingly, formine a turbid liquid.
The dear solutions sometimes become turbid on standing, but do not depodt the whole
of the caldum which they contain. Hence caldum can neyer be completely predpi-
tated as carbonate from solutions containing ammoniacal salts. Carbonate of calcium
boiled witii solution of sal-ammoniac, the water being renewed as it eyaporates, dis*
solyes almost eompletdy as chloride of caldum, with eyolution of carbonate of am*
monium.

Carbonate of caldum heated to full redness in. open yessels, is resolyed into lime and
carbonic anhydride. The decompodtion commences eyen at a low red heat, so that in
estimating caldum as carbonate in analysis, the ignited ^redpitate should, before
weiring, be moistened with carbonate of ammonium, and agam heated, just suffidently
to £riy6 off the excess of that salt ; by this means, any carbonic add that may hayo
been driyen off will be restored. In a current of air or any other gas, and especially of
steam, the decompodtion takes place at a lower temperature. I^ on the other hand,
the carbonate of caldum be ignited a dosed iron tube, so that the carbonic anhydrido
cannot escape, it foses to a fine-grained mass, consisting of crystals of ealcspar, and
haying the appearance of marble.

Unrated Ifeuiral Carbonate of Caleium, Hydroealeiie, CaKlCSaq. — ^This salt is
obtamed in small, yeiy acute, rhombohedral crystals, of spedfic grayity 1*783, by boil-
ing lime in a concentrated solution' of sugar, milk-sugar, starch, or gum, and leaying
the solution for some months in a cold place (Felouze, Ann. Ch. Phys. [2] xlyiii 301\
Beoquerel, by expodng a solution of ume in sugar-water, to the action of a 12-pair
yoltaic battcoy, obtained crystals haying the same composition, but the form of a
rhombic prism with dihedral summits, like anagonite. C^stals of the same form and
composition were found b^ Scheerer (Pogg. Ann. lyiii. 382), in a running stream.
Salm-Horstmar found six«sided prisms of the same composition, depodted from spring-
water in the copper tube of a pump.

The crystals remain unaltered below 19^ or 20^ C, dther in the air or under
water, but crumble to a white powder at a somewhat higher temperature, and if quickly
heated to 30^, they are conyerted into a pasty mass, 'vniich dries up to a powder. In
ether at 30^, they crumble to a white powder ; also in hydrated alcohol : but boiling
absolute alcohol extracts from them only 2 at water, rendering them opaque, but with-
out change of form. The remaining crystals with 3 at. wat«ff, effloresce yery quickly
in tha air, but may be kept unaltered at a temperature bdow 10^. (G-m. iiL 188.)

Ortkocarbonate, CaK70^, or 2CaK).C0'.— This, with 1 at. water (sometimes regarded
as a hydrooarbonate, Ca*C0'.2CaH0), is, according to Fuehs (Poffi. Ann. xxyii. 601),
the oompodtion of the slaked lime produced by exposing quick lune to the air in its
ordinary state. At a strong red heat*, it giyes off water and carbonic anhydride, and
yidds a quick lime which dakea in water, not with yiolenoe, but dowly and with only
moderate rise of temperature. At a low red heat, the hydrated orthocarbonate giyes off
only water, leaying the anhydrous salt, Ca^CO^, which, according to Fuchs, is ukewise
Produced when ordinary carbonate of caldum is exposed to a m^erato red heat, only
naif of the carbonic anhydride beinff then expelled, and leaying a reddue, which in
contact with water does not slake but nardens, bidng in fact conyerted into the hydrated
orthocarbonate.

Acid Carbonate. — ^This salt, which perhaps has the composition CaHCO*, is known
only in solution, and may be obtained in that state by pasdng carbonic anhydride into

782 CARBONATES.

cold water in wHch the netitral carbonate is mispended. Water saturated with car-
bonic acid dissolves j^ part of the neutral carbonate, at 0^ C, and yjU at 10^
(Lassaigne, J. Ohim. m^d. 1848, p. 312^. In consequence of this sparing Bolubilitf,
solutions of caldnm-salts are precipitatea by alkaline bicarbonates even in the cold.
The solution of the acid salt has a slight alkaline reaction if c[uite saturated, but if the
carbonic add is in excess, it exhibits an acid reaction. It is decomposed, with sepa-
ration of the neutral carbonate, on exposure to the air, or more quickly when heated.
It plajB an important part in the economy of nature, bein^ formed whererer carbonate
of calcium or other <»lcareous formations, especially silicates, come in contact with
water containing carbonic acid, and thus entering in greater or smaller quantity into
the composition of almost all natural waters. Waters which contain it in considerable
quantity, form deposits of carbonate of calcium on their banks or on objects immersed
in them: hence the formation of calcareous petrifactions, of calcareous tufa and
sinter, of stalactites, stalagmites, &c To the same cause also is due the turbidity
which appears in river or spring water when heated, and the incrustation or furring of
kettles and boilers. The formation of this incrustation may to a certain extent be
prevented, by the addition of sal-ammoniac to the water, whereby, as already observed,
the carbonate of calcium is converted into soluble chloride.

Cabboka-TB of Cbbiuh, Ca*CO* + 3aq., or Ce'H'CO* + 2aq., formed, on ex-
posing hydrated cerous oxide to the air, or by precipitation, is a white powder, which
when ignited the air, is partly converted into lemon-yellow coroso-ceric oxide. It
occurs native, with fluoride of calcium, as Parisite {q. v.)

Chboxous Cabbowatb, is obtained by adding a solution of protochloride of
chromium to carbonate of potassium. The predpitate is red or reddish-brown, if the
solution is hot, but has the form of dense yellow or bluish-green flakes, if the solution is
cold : it appears, however, to have the same composition in all cases. (Mob erg.)

Ca.bbona.tb8 of Coba.lt. The anhydrous carbonate Co*CO*, is obtained by
heating chloride of cobalt with carbonate gf caldum to 150^ C. in a sealed tube for
eighteen hours, or by decomposing the chloride with a solution of add carbonate of
sodium supersaturated with carbomc add, and heated to 140^ in a strong vessel dosed
with a cork, through which the carbonic add escapes slowly. It is a light rose-
coloured, sandy powder, composed of microscopic rhombohedrons, and is not attacked in
the cold by adds, not even by nitric or hydirochloric add. (S^narmont, Ann. Ch.
Phys. [3] XXX. 129.)

The predpitates fbrmed by adding cobalt-solutions to alkaline carbonates, are all
hydrated carbonates, or double carbonates of cobalt and the alkali-metaL The former
may be represented as ortho- or meta-carbonates, combined in various proportions with
hydrate of cobalt, the compodtion varying according to the temperature and concen-
tration of the solutions.

The predpitate formed on adding sulphate of cobalt to neutral carbonate of SModium,
the solutions being concentrated or moderatdy dilute, and either hot or cold, is rose-
coloured, and when dried at 100° C, consists of CoK)0».3CoHO + Jaq., or Co*CO*.CoHO
H- |aq. (Setterberg, Pogg. Ann. xix. 55; Winkelblech, Ann. Ch. Pharm. xiiL
148 ; H. Bose, ibid, l-rrr 237). But very weak solutions mixed at the boiling heat,
yield a blue predpitate, consisting of Co«CO».4CoHO + aq., or Co<CO*.2CoHO + 2aq.
The predpitates are very diflicult to wash. Heated above 150^ C. in contact with the
air, they gradually give off water and carbonic anhydride, and are converted into
sesquioxide of cobalt (H. Bose). The first-mentioned predpitate is partly converted
into sesquioxide by boiHn^ wim water (Field, Chem. Soc Qu. J. xiv. 50). The
same precipitate digested with solution of diadd carbonate of sodium or of ammonium,
is graduaUy converted into 3Co»CO» + aq. (H. Beville, Ann. Ch. Phys, [3]
xxxiiL 75.)

A hydrated carbonate of cobalt called RenUngUmite^ whose precise compodtion is
not known, occurs as a soft, earthy, rose-coloured incrustation, on thin veins of serpen-
tine, at a copper^mine near Pinksburg, Carroll County, Haryland. (J. C. Booth, SilL
Am. J. [2] XV. 48.)

Carbonate of Cobalt and Potassium, — Nitrate or sulphate of cobalt forms with excess
of diacid carbonate of potassium a rose-coloured predpitate, which gradually changes
to a network of rose-coloured crystals, easily decomposed by water, and consisting of a
meta-carbonate, (Co«KH)C«0« + 4aq.,[or 2(CoO.GO^) + K0.2CO^ + 9^0J(H. Bose,
H. D e V i 1 1 e). Nitrate of cobalt and sesquicarbonate of potasdum, yield distinct crys-
tals, containing CoKCO»+ 2 aq. (Deville.)

Carbonate of Cobalt and Sodium. — ^Nitrate of cobalt and sesquicarbonate of sodium,
yield a mixture of small prismatic crystals, CoNaCO* + 2 aq., and dark-red crystals,
apparently cube-like rhombohedrons, containing CoNaCC + 5aq. (Devil 1 e).

CARBONATES. 783

Oabbonatss of Coppsb. — ^Two of these oomponndB occur as natural mineralSi
viz. Malachite and Azurite, They may be most simply represented as orthocarbonatesi
viz.:

MalachiU as UtracufHo ortkocarbonate, Cu^CO^ + aq«

JzturiU as iriouprio orihocarhonaU, ^ | G0\

They may also be regarded as metacarbonates combined with cnpric hydrate, vis.
malachite as CuK)0».20uH0 ; azurite as Cu»CO».CiiHO. The hydrated tetracnpric
salt is formed artifidaQy by precipitation. The anhydrous metacarbonato Cu'CO*, is
not known.

Tetraeuprio Orthoearhonaie^ ChiKK)^ + aq. McdaeMte, Green CarhoTuUe of
Copper^ Mountain ffveen^ Atlas ore. — This mineral forms prismatic erystals belonging to
the monocUnic system, in which the lengths of the orthodiagonal, dinodiagonal, and prin-
cipal axis are to one another as 1*273 : 1 : 0*5358. The inclination of the dinodiaeoniil
to Uie principal axis does not diffeiannch from. 90^. The crystals are generally reduced
to thin prisms by predominance of die fiices ooP and ooP oo, and terminated by oP, + P,
— P 00. Cleayage perfect parallel to — P oo and ooP (Kopp). More fireqnently, how-
eyer, it occors in laminar, fibrous, compac^ or earthy masses. Specific grayity » 3*7
to 4*0. Hardness «* 3*6 to 4. *It vanes in colour from, emerald to grass-^en, and
exhibits all degrees of transparency down to perfect qpacily. It takes a high polish,
and when in l^ge masses is cut into tables, snuff-boxes, rases, &c Malachite usually
accompanies other ores of copper. Perfect crystals are yeiy rare. The fibrous variety
occurs abundantly in Siberia, at Chessy in France, at Sandlodge in Shetland; the com-
.pact variety at Sichwarts in the Tyrol, in Cornwall, and in Cumberland. At the copper
mines of Nischne Tasilsk, a bed of malachite was opened which yielded many tons of
the mineraL Malachite is also found on the west coast of Amca, and in several
localities in North America. (Dana, ii. 468.)

Cuprie salts treated wiUi alkaline carbonates, yield at first a greenish-blue preci-
pitate, consisting, according to Brunner, of Cu^CO* + 2aq. ; which, however, when left
in contact with the liquid, and washed, becomes compact and green, and aoauires the
composition of malaclute. When heated to 200^ C. it is slo^y converted into black
cupnc oxide, which obstinately retains a small quantity of water. Malachite slowly
decomposes in the same manner at 220^. The tetraeuprio salt, either native or preci-
^itateo, is decomposed by boiling with water, givixig up carbonic acid, and being entirely
converted into black oxide of copper. (H. Hose ; ¥, Field, Chem. Soc Qu. J. xiv. 71.)
By digestion with neutral carbonate of sodium at 120^ F. (48*8^ C.) it is converted
into 6Cu*0.C0>, or Cu«C0\4Cu*0. Boiled with sesouicarbonate of sodium, it dissolves,
forming a blue liquid, which is not decomposed even oy long boiling ; but when sulphate
of copper is boiled for a very long time with sesquicarbonate of sodium, a green precipi-
tate of tetraeuprio carbonate is obtained, and on filtering from this and adding more sid-
phate of oopper to the filtrate, the basic salt just mentioned is precipitated, as a dense
black powder (Field). Aocordinff to Deville, tetraeuprio carbonate digested with
neutral carbonate of sodium, is partly converted into 8Cu*0.C0* + 6H?0.

Anhydrous tetraeuprio carbonate^ Cu^CO\ or 2Cn'0.C0', occurs, according to
Thomson {Mineraiogy^ i 601), as myeorinj a mineral from Mysore in Hindostan, con-
taining also ferric oxuLe and silica. Dana suggests that it may be only an impure
mftliu*hitff.

Trieupric Orthocarbonate, CvFBiCO* (or SCu0.2C(^ + aq,) Asurite, Lasurite,
Blue Cartonaie of Copper, Blue Malachite, Cheesy Copper, Chessylite, Kupferlasur, — This
mineral occurs in fine crystals, belonpiing to the monoclmic system, in which the orthodiaeo-
nal, dinodiagonal, and principal axis are to one another as 1*181 : 1 : 2*076. Inclination
of axes 87^ 39'. Observed fBc&n ooP . oP. [Poo ] . [JPoo ]. ooPoo , together with others of
lees frequent occurrence. The crystals are often prismaticalN' elongated in the direc-
tion of the orthodiagonaL Cleavage parallel to [Poo] (Kopp's KrystaUographic,
p. 803). The mineru occurs also massive and in imitative shapes, having a columnar
composition, also dull and earthy. Specific gravity » 3*6 to 3*831. Hardness >» 3*6
to 4*26. Lustre vitreous, ahnost adamantine. Colour, various shades of azure, passing
into Prussian-blue. Streak-blue, lighter than the colour. Transparent to sub-translucent.
Fracture oonchoidaL Brittle. It is found in splendid crystaUisations at Chessy near
Lyons, in fine crystals also in Siberia, at Moldavia in the Bannat, at Wheal duller,
near Bedruth in Cornwall ; at Porto BeUo, South America ; and in small quantities
at Alston Moor, Wanlockhead, &c. It is found also in the States of Pennsylvania,
T^ew York, and New Jemey. (Dana, ii. 469.)

Azurite when ground to fine powder forms a bri^t blue pigment ; but it is not of
9iuch use, as it is apt to turn green by exposure. When boiled with water, it deccon-

784 CARBONATES.

poaee like malacbite, yielding black oxide of copper. Heated with a concentrated so-
lotion of diacid carbonate of sodimn, it yields a blue solution, which, after protzacted
boiling, deposits a green precipitate of malachite (Field). According to Phillips
(Ann. Ch. Phys. [2] Til. 44) a cupric carbonate, called blue fterditer^ baring the same
composition as azorite, is obtained by a secret process.

Potastio-cuprio Carbonate. — Nitoite of copper forms with diacid carbonate of potas-
sium, a deqpDloe liquid, which after a few hours deposits a silky mass, consistmg of
6CuH).K«a.6CO* + 10 aq. or (Cu'«K*H«)(>0« + 6 aq. (De v ille, Ann. Ch. Fhys. [8]
xxxiii 75).

SoduHfuprie CaarbonaUj CuKaCH)* + 3 aq., is obtained by adding an add solution of
nitrate of copper to carbonate of potassium containing soda, and leaving the precipitate
in the liquid for a considerable tmie ; also by the action of diacid carbonate of sodium
on tetracnprio carbonate at 40^ — 6(P G. It forms rhombic prisms, having the angles of
the obtuse ed^ — 123^ 14\ and acuminated with four faces resting on the prismatie
edges. (DeviUe.) •

Cuprou$ Carbonate f — ^The yellow precipitate obtained by adding carbonate of sodium
to a solution of cuprous chloride in nydrochloric acid was said by Colin to be a cuprous
carbonate^ but according to H Gmelin (Handbook, y. 414), it is merely cuprous
hydrate.

Carbonate of Ouprafnmoniumf (NH'Cu)'CO*, is obtiined in large deep blue crystals
by dissolving tricupric or tetracupric carbonate in carbonate of a-TnmnTn'A, and pouring
the solution mto aJcohoL It is rapidly decomposed by water into carbonate of am-
monia and a basic carbonate of copper, CuK/0^2CuH0 + 2 aq. (Favre, IhM de
CUmiopar Fdoiue et Frhiw, ilL 201). llie same ammouiacal compound appears to
be formed when cupric oxide or finely divided metallic copper is digested in ammonia
with aoc8ss of air.

CABBOVA.TB OF DiDTXiux IS obtained as a white, slightly rose-ooLoured precipi-
tate containing BiKX)' + 2 a(}., on adding an alkaline carTOuate to the solution of a
didyminm-salt. At 100^ C. it gives off two-thirds of its water and a small quantity of
carbonic add. (Marignac.)
Cabbonatb or Ethti.. See Cabbomic Ethbbs.

CABB0VA.TB ov Glucihux is pFoduccd when the hydrate is exposed to the air,
also by predpitating gludnum-salts with alkaline carbonates, not in excess, and by
boiling a solution of carbonate of glucinum and ammonium. It appears to vary in com-
position; the predpitate obtained by the last-mentioned process has, according to
Schafbotsch, the composition 5G1*0.C0' + 6 aq. or Gl*00^6GlHO•f 2 aq. It appears
to bedecomposed by boiling with water. It dissolves in alkaline carbonates, forming
double salts.

Carbonate of Glucinum and Ammonium, — ^When a solution of gludna in aqueous ear'
bonate of ammonia is heated to the boiling point, till the liquid begins to show turbidity,
then filtered, and the filtrate mixed with alcohol till it becomes milky, white tran-
sparent crystals are gradually deposited, containing 4G1*0.3C0'.B?0 i- 3[(NH*)K).C0']
or perhaps GlH0.3dl(NH*)C0'. They become dull on exposure to the air, are. inso-
luble in absolute alcohol, but dissolve readily in cold water, and are decomposed by
hot water, with evolution of carbonate of ammonia. (Bebray, Ann. Ch. I^hys. [3]
xliv. 5.)

Carbonate of Glucinum and Potaesium, G1H0.3G1KC0*, is obtained in the same
manner as the ammonium-salt, which it resembles in its properties. (Debray.)
Carbonate of gludnum likewise forms a double salt with carbonate of sodium.
Cabbonjltbs of Ibox. — Ferric carbonate does not appear to exist. The predpitate
formed by alkaline carbonates in solution of ferric nitrate, consists, according to
L. Gmelin (Handbook^ v. 222), of ferric hydrate without a trace of carbonic add.
According to Soubeiran (Ann. Ch. Fhys. [2] x1lv« 326), the predpitate thrown down
by alkaline carbonates from ferrous salts, contains, after thorough washing and expo-
sure in thin layers to the moist air of a cellar for six months, 71*4 per cent, ferric
oxide (quite free from ferrous oxide), 8*3 carbonic anhydride, and 20*0 water ; but it
is doubtful whether a definite carbonate is formed.

Double carbonates of ferricum and the alkali-metals appear to be cajpable of existing
in solution, though not in the soHd state. When a feme salt is precipitated by con-
centrated carbonate of ammonia» the predpitated ferric hydrate gradually redisssolvea,
but is slowly deposited a^ain on diluting with water. Well washed ferric hydrate,
however, does not dissolve in carbonate of ammonia, so that the presence of the ammo-
niacal salt formed in the decomposition appears to be necessary to the solution of the
ferric hydrate. Similar reactions are obtained with strong solutions of carbonate of
potassium or sodium.

Ferroui Carbonate, — ^The anhydrous metacarbonate FeKJO' <» Fe'O.CO*, exists
abundantly as a natural mineral, viz. Spathic or Sparry iron ore^ also called Ckaly"

CARBONATES. 785

bite, Sideriie, SideroM, Brown ^par, SpharotideriU, Junkerite, StraMstdn, Eisenspath,
Spatheisenatein^ Oligonspath, This mineral forms rhombohedral crystals, having for
their primary form a rhombohedron, in which the principal axis is to the secondary
axes as 0*8117: 1, and the inclination of the faces meeting in the terminal edges
ss 107° 0', this fbrm being either solitary or predominant, and often with cured
faces; sometimes in twin-crystals. It also oocnrs in botryoi'dAl and globular forms (as
apharoMderiteX occasionally in silky fibrous masses; often deavable massiTO, with clear-
age planes nndulate ; also coarse or fine granular. Specific gravity » 3*7 to 3*9. Hard-
ness B 3*5 to 4*5. Lustre vitreous to pearly. Streak white. Colour ash-grey, yellowish-
grey, greenish-grey ; also brown and brownish-red, rarely green ; sometimes white.
Translucent to subtiiiDslucent. Fracture uneven. Brittle. (Dana, ii 445.)

Pure ferrous carbonate would contain 37*93 per cent, carbonic anhydride and 62*07
ferrous oxide. The mineral always contains more or leas of the carbonates of manga-
nese, magnesium,* and calcium. A black variety from Babbowsky gave 36*61 GO*,
57*91 FeH), 1*51 Mn'O, trace of MgK), 0*59 Ca*0, and 0*60 gangue. A specimen
from the neighbourhood of Durham yielded 35*90 C0«, 54*57 FeK), 1*15 MnH), 318
Ca*0, and 2*63 water (» 97*43). The variety called oligonspar contains 25*31 per
cent, manganous oxide ; other varieties contain 12 to 15 per cent, magnesia.

Ferrous carbonate ia a very abundant mineral, occurring in gneiss, mica slate, day
slate, and in connection with the coal formation. At Freiberg it occurs in silver mines.
In Cornwall it accompanies tin. It is also found accompanying copper and^ iron py-
rites, galena, vitre«us copper, &c In New York, accordrnff to ^eck, it is almost
always associated with specular iron. Occasionally it is found in trap rocks as sphse-
rosiderite (Dana). A siliceous or argillaceous variety called clay iron stone, which
occurs in tne coal measures, is one of the most abundant and valuable ores of iron.
VeiT large quantities of it are found and worked in South Stafibrdshire, at Mertbyr
l^dvil in South Wales, and near Glasgow.

Anhydrous ferrous carbonate may be prepared artificially by processes similar to those
already described for carbonate of cobalt (p. 782). It then forms a greyish-whit« crys-
talline sand, composed of minute rhombohedrons, scarcely attacked by dilute acids,
nearly unalteral^ in dry air, gradually assuming a light red tint in moist air. It is
of a darker grey colour and less alterable in we air in proportion as the heat em-
ployed in its preparation has been greater and longer continued. (S 6 n ar mo n t, Ann.
Ch. Phys. [3] XXX. 129.)

Hydrated ferrous carbonate is predpitated on mixing a ferrous salt with an alkaline
carbonate, in thick white fiakes, which, on exposure to the air, absorb oxygen and give
ofi^ carbonic add, first assuminga dirtv green colour, and ultimately changing to yel-
lowish-brown ferric hydrate. Hence it is difficult to obtain the precipitated ferrous
carbonate in a pure and definite state. The best mode of proceeding is to predpitate
ferrous sulphate quite fr'ee from feme sulphate, with alkaline monocarbonate or
bicarbonate, both salts being dissolved in water which has been thoroughly freed
frt>m air by boiling, wash the predpitate out of contact with the air, e.ff. by decan-
tation with thoroughly de-aSrated water, keeping the vessd quite full and dosed, and
dry it in an atmosphere of carbonic anhydride. The salt thus prepared is a greenish
tasteless powder, which is used in medicine ; it is tolerably permanent if thoroughly dried ;
but if moist it oxidises quickly in the air, becoming hot, and p;iving off water and car-
bonic acid. It may be rendered more permanent by mixing it with sugar while
moist.

Acid Salt — ^Aqueous carbonic acid dissolves ferrous carbonate ; also metallic iron
with evolution of nydrogen. The solution, which exists in many natural waters, called
chalybeate toaters, is colourless, has a slightly ferruginous taste, is decomposed, with
separation of ferric hydrate, by contact with the air, and gives a black pi^pitate with
sulphuretted hydrogen. To preserve chalybeate water in vessels, they must first be
filled with carbonic anhydride, then opened and filled below the surface of the water,
and lastly corked under water. A less effident mode of preservation is the introduc-
tion of iron wire and a few grains of sugar.

Cabbgnatb of Lanthanum, LaH)0' + 3 aq., is found native as Lanthanite, a
mineral (formerly mistaken for carbonate of cerium) occurring in four-sided plates or
minute tables of the trimetric system, with bevelled edges ; also fine-granular, and
earthy. Spedfic gravity 2*67 (?) Hardness 2*5 to 3. It has a dull or pearly lustre^
and greyisn-white, faint pink, or yellowish colour. It is found coating cerite at
Bastnas in Sweden, and in silurian limestone, with the zinc ores of the Saucon valley,
Lehigh county, Pennsylvania. The American mineral was found by J. L. Smith to
coDtain 54*90 per cent. La*0, with oxide of didymium, 22*58 CO', and 24*09 water
(« 101-57), the formula requiring 52*94 La*0, 21*11 CO*, and 25*95 water. With borax
or phosphorus-salt it yidds a glass having an amethystine colour, arising from didy-
mium. (Dana^ ii. 456.)

Vol. L 3 E

786 CAKBONATES.

Carbonate of lanthsnam obtained by precipitation fofnaa a white gelatinous mass,
which gradually changes into shining ciystalline scales.

Gabbovatbs op Lbad. — ^The anhydrous metacarbonato, IVCO» or Pb*O.CO», is
found native as white lead ore or cerueite, in crystals of the tnmetrie system, isomor-
phons with airagonite, witherite, and strontianite, and in which the brachydiagonal,

- , — — — dearage

moderately easy parallel to ooP, less so parallel to 2F oo. It is sometimes found in
twin-eiystAb, the face of combination being oo P (Kopp's KryetaMogrofpHe^ p. 261) ;
rarely fibrous ; often granulariy massiye and compact Specific gravity 6*466 to 6-480.
Hardness 3 to 3*5, in some earthy yarieties as low as 5*4. ' Colomrless when pure, tran-
sparent or translucent in yarions degree and with adamantine lustre. Fracture conchoi-
dal. Very britUe. White lead ore is found in Cornwall and Cmnberland, at Leadhills
and Wamockhead in Scotland, in Siberia, in the Harz, in Bohemia, and many other
localities. It sometimes occTirs altered to phosphate of lead by the action of water
containing phosphate of calcium ; to galena hj the action of sulphuretted hydrogen,
and to minium by oxidation ; also more or less to magnesite^ malachite, ana chiyso-
eolla. (Dana.)
Som4ead or eeragine is a compound of carbonate and chloride of lead.

ffydrocarbonates, — ^The precipitate formed in solutions of lead-salts by alkaline
carbonates varies in composition according to the temperature and concentration of tho
liquids. According to Berzelius, the anhydrous metaoirbonate is obtained by treating
nitrate of lead with excess of carbonate of ammonia ; according to Le fort (J. Pharm.
[3] xy. 26), by precipitating with alkaline carbonates in the cold, whereas from hot
solutions a hydrated salt, dPb^O.CCHK), is obtained. According to H. Bose (Ann.
Ch. Pharm. Ixxx. 236), tiie precipitate always contains hydrate of lead. Equivalent
quantities of nitrate of lead and neutral carbonate of sodium in cold strong solutions yidd
the compound 6Pb'CO'.2PbHO + aq., which gives off some of its water at 100° C,
and takes up more carbonic acid ; with cold dilute, or hot concentrated solutions, the
compound 6Pb"CO".2PbHO is obtained, and with hot dilute solutions 3Pb«CO».2PbHO.
When the carbonate of sodium is added in excess, the precipitate consists chiefly of
Pb«CO».PbHO or (Pb"H)CO*, but contains a small quantity of soda.

Hydrated carbonates of lead are also formed by the direct action of carbonic acid on
hydrate of lead, and the compounds thus obtained differ from the precipitated carbo-
nate, in being amorphous and perfectly opaque, whereas the precipitatea carbonate is
an aggregate of minute transparent crystalline grains. Hence the carbonate formed by
absorption of carbonic acid is much better adapted for a pigment, and is extensively used
as such under the name of white lead or ceruse ; its great opacity eives it that quality
which painters call body, enabling a small quantify of it to form, a brilliant white coat-
ingover a considerable surface.

There are two methods of prepared white lead. In the older, called the Butch
method, because it was originaJly practised in Holland, thin, sheets of lead are placed
over gallipots containing weak acetic acid (water with about 2^ per cent of the strong
acid), the pots being embedded in fermenting tan, the temperature of which varies from
140° to 160° F. The action is often very rapid, the metal disappearing in a few weeks
to the centre of the sheet. In this process from 2 to 2^ tons of lead (4480 to 6600 lbs.
are converted into carbonate by a quantity of vinegar containing not more than 60 lbs.
of strong acetic acid. It is evident^ therefore, that the metal is neither oxidiBed nor
carbonated at the expense of the acetic acid. The oxygen is derived from the air, and
the carbonic acid from the fermenting tan; the acetic acid merely serves to dissolve tho
oxide of lea#and convert it into a basic acetate, which is easily decomposed by car-
bonic acid, the acetic acid being thereby set free te act upon another portion of oxide
of lead. That this is really the mode of action, is shown by what takes place in the
more modem process, in which oxide of lead (litharge) is mixed with water and about
1 per cent, of neutral acetate of lead, and carbonic acid gas is passed over it : in this
manner the oxide is quickly converted into excellent white lead. Nitrate of lead has
also been used in this latter process in place of the acetate.

White lead is a mixture or compound of carbonate and hydrate of lead, in various
proportions. Mulder (Ann. Ch. Pharm. •«"rn'"' 242), from the analysis of numerous
samrfes, concluded that there are three varieties of it> viz. : Pb*CO» J^bHO ; 6Pb«C0«.
6PbH0, and 3Pb*CO».2PbHO. J. A. Phillips (Chem. Soc Qu. J. iv. 166) found
the composition of four samples to agree with me first of these formulae, one with the
third, and another to contain 6Pb*CO".2PbHO.

White lead is often mixed with heavy spar and gypsum, the addition of which
rendera it less liable to be blackened by the action of sulphuretted hydrogen. Oxide

CARBONATES. 787

of zinc is likewise added for the same purpose. (Gm. ir. 127. Ur^9 Dictionary of
Arts, Mant{faciures and Nines, iii 1015 ; GrdhanCa Chemistry, 2nd edition, ii. 120.)

Acid Carbonate, — Carbonate of lead dissolyes slightly in water containing carbonic
acid ; the solution contains from ^^ to j^ of lead-oxide, is rendered torbid by alka-
line carbonates, and coloured brown oy sulphuretted hydrogen. (See Lbad.)

Carbonate of Lead and Sodium. 4Fb'C0'.Na*C0'. — ^Produced, according to
Berzelius (Fogg. Ann. zlyii. 199), when nitrate of lead is precipitated by carbonate
of sodium, tne precipitate boiled in the alkaline liquid, then washed and dried at
160O 0.

Cabbonatb of Lithium, LiK?0*. — ^This salt, which is slightly soluble in water,
exists in the waters of Carlsbad, Eranzensbad, and others. It is prepared by dissolv-
ing an excess of carbonate of ammonia in a concentrated solution of chloride of lithium,
and waging the resulting precipitate withalcohol ; or by precipitating sulphate of lithium
with acetate of barium, evaporating the filtrate, and decomposing the residual acetate
of Hthium by ignition. The salt melts at a low red heat> and solidifies to a vitreous
mass on cooling. It is not decomposed by heat. It dissolves in 100 pts. of cold
water (Vauquelin); in 130 pts. at IS^C, and in 128*5 pts. at 100^ (Kremers
Jahresber. d. Chem. 1856, p. 275). The saturated solution boils at 100^ (Kremers
ibid. p. 294). The solution is alkaline, and deposits the salt by slow evaporation, in
small prisms. It decomposes the salts of ammonia, and gives up its carbonic acid
to caustic baryta and lime.

Water saturated with carbonic acid dissolves carbonate of lithium more freely than
pure water.

CA.BB0NATBS OF MA.ONB8iuif. — The auhydrous metacarbonate, Hg^CO', or
Mg'O.CO^ occurs native as moffnesite, associated with serpentine and other magnesian
rodos. It is found in rhombohedral oystals, isomorphous with calcspar. Bafcio of the
principal axis to the secondary axes » 0'8117 : 1. Angle of the terminal edges »
107^ 25. Cleavage perfect parallel to the rhombohedral tacea. It also occurs massive,
granular, or fibrous, sometimes in radiating groups; also very compact. Specific
gravity « 2*8 to 8. Hardness «■ 3*5 to 4*5. It is white, or with various shades of
yellow, grey, and brown, has a vitreous or silky lustre, and exhibits all degrees of
transparency, down to complete opacity. Fracture flat, conchoi'daL It is infusible
before the blowpipe^ and dissolves slowly and with little efiervesoenoe in acids. It
occurs nearly pure, with only small quantities of water and the carbonates of
iron, manganese^ and calcium, in Moravia, Styria, Silesia^ Piedmont, Spain, and at
several localities in the United States. Carbonate of magnesium occurs also associated
in various proportions with the carbonates of iron, manganese, and calcium, forming
the minerals sphserosiderite, diaUogite, dolomite, bitter spar, &c.

Anhydrous metacarbonate of magnesium cannot be prepared by precipitating a so-
luble maenesium-salt with an alkaline carbonate, as the precipitate Sius formed always
contains hydrate of magnesium ; but by suspending the washed precipitate in water,
passing carbonic add gas through the liauia till the precipitate is dissolved, and eva-
porating the solution by heat^ the anhydrous salt is obtained as a crystallinepowder,
which when examined by the microscope, exhibits the form of arragonite (B!. Rose,
Pogg. Ann, xlii 366). It is likewise obtained by heating sulphate of magnesium with
catenate of sodium, to 160^ C. in a sealed tube, or by endosmg a soluble magnesium-
salt, together with an alkaline dicarbonate supersaturated with carbonic acid, in a
strong vessel closed by a cork, through which the carbonic add can escape slowly.
By this last method, it is obtained in microscopic rhombohedrons, like native magnesite
(S^narmont, Compt rend, xxviii 693 ; Ann. Ch. Phys. [3] xxx. 129). Anhydrous
carbonate of magnesium is therefore isodimorphous with carbonate of caldum. When
moistened with water, it gives an alkaline reaction with litmus and violets. If the
solution of carbonate of magnesium in excess of carbonic add be left to evaporate
spontaneously, or kept for some time at 50^ C, it deposits small hexf^nal prisms,
containing MgfCO' + 3aq. : they give up their water m warm air, becoming opaque,
but retaining their form. The same hydrated crystals aro obtained by mixing the
solutions of sulphate of magnesium and sesquicarbonate of potassium and sodium, and
leaving the mixture to stuid. A saturated solution of carbonate of magnesium in
aqueous carbonic add, exposed for some time to a winter temperature, deposits
transparent oblique prismatic crystals, containing 5 at water: Mg'C0' + 5aq. They
are converted into the preceding, with loss of transparency, by eoroosure to the air,
more quickly in sunshine, and by immersion in water at 50^ C. If boiled with water,
they give up part of their carbonic add, and are ultimately converted into 2Mg'C0'.
MgHO + 2aq. (Fritzsche.)

Hydrocarbonates. a. 5M^0.4CO» + 5aq. «2Mg»C0«J«[gH0 + 2 aq. « (Mg»H«)C*0«
+ aq. — ^Produced, as just mentioned, by the action of water on Mg*CO* + 5 aq., better by

3b2

788 CARBONATES.

boiling with water containiDg ammonia (FritEsche); alao by precipitating sulphate
of magnesium with carbonate of sodium, and drying the precipitate at 100^ C. (H. Rose,
Ann Ch. Fharm. Ixxx. 234) ; also, according to Beraelius, by boiling a solution of acid
carbonate of magnesium for a long time. It is a white granular powder.

b. 4MgK).3CO* + 4aq. « 3Mg«CO».2MgHO +3aq. « (Mg«H*)C«0« + 2aq.— Found
natiye as HydromagnesiU^ in small white, brittle, or acicular ciystab, of the monocUnic
system, or in chall^ crusts. Specific gravity = 2*146 to 2*18. Hardness of the ciys-
tals w 3*5. It is found at Hrubschitz in MoraTia in serpentine ; in Negroponte near
£umi ; and czystallised with serpentine and brucite (hydrate of magnesium), in Lan-
caster county, Pennsylyania. Lancasterite is a mixture of brucite and hydromagnesite.
(Dana, ii 456.)

A substance of the same composition is obtained by mixing sulphate of magnesium
with excess of a hot solution of carbonate of potassium, and boiling the precipitate
with fresh quantities of water, as Ions as any acid carbonate dissolves out (Berzelius) ;
also, according to Fritzsche, by boiling a saturated solution of the add carbonate, and
twice boiling the resulting precipitate with fresh quantities of water. It is a white
powder, slightly soluble in water, and forming an alkaline solution. When dried at
100° 0. in the air, it absorbs carbonic add, and is converted into 5MgH).4CO' + 5aq.
(H. Rose.)

c. 3MgK).2CO* + 3aq. (?) Obtained, according to Fritzsche (Pogg. Ann. xxxvii.
310), by predpitating sulphate of magnesium with a veiy large excess of carbonate of
sodium, boiling the whole till the precipitate passes from the flocculent to the granular
condition ; then washing and boihng rapidly with water, pouring off the liquid, and
twice boiling the residue with fr^h water. It consists of small grains mixed with a
small quantity of the original flocculent predpitate. According to Berzelius, the pre-
dpitate obtained as above may contain carbonate of sodium. According to H. Rose, the
predpitate formed by carbonate of sodium with sulphate of maenedum always contains
5Mg'0 to 4C0^ whatever may be the temperature and strengu of the solutions.

The pharmaceutical preparation known as Magnesia alba, is a mixture of the several
hydrocarbonates of magnesium, the proportions depending on the relative quantity of
the precipitant, the degree of dilution, and the temperature at which predpitaticHi
takes place. It is prepared on the large scale hj fvedpitating sulphate, nitrate, or
chloride of magnesium with carbonate of potassium or sodium. Various mineral
waters containing sulphate of magnesium, such as the Epsom water, are used for the
purpose, also the mother-liquor of sea-water, of many salt-springs, and of many kinds
of saltpetre ; most of these liquids, however, contain lime, which must be previously
separated by sulphate of potassium or sodium. After being well washed with hot
water, it forms a very light, and bulky powder. The utmost degree of lightness is ob-
tained by allowing the predpitate to freeze while still moist (G-m. iii 228.)

Acid Carbonate. — Magnesia alba shaken up with aqueous carbonic add, forms a
solution having a bitter taste and alkaline reaction, and containing, according to Sou-
beiran, just twice as much carbonic add with the same quantity of magnesia as the
normal salt (probably MgHCO'). It becomes turbid at 75^ C, but recovers its deamess
on cooUng. When heated to 50^ C, or evaporated in vacuo, it depodts the trihydrated
metacarl^nate, MgH^O* + 3aq. (Berzelius, Fritzsche.)

Carbonate of Magnesium and Ammonium^ Mg(NH*)CO* + 2H*0, crys-
tallises in translucent rhombohedrons from a mixture of the cold aqueous solutions ol
sulphate or chloride of magnedum and sesquicarbonate of ammonia, the latter in
excess, or from a solution of hydrate of magnesium in sesquicarbonate of ammonia.

Carbonate of Magnesium and Potassium^ (Mg*K'H')C*0" + 8 aq., is de-
posited after a few days in large crystals from a cold aqueous mixture of chloride or
nitrate of magnedum with excess of diacid carbonate of potassium. The crystals become
opaque and lose water at 100° C, and are decomposed by water, which dissolves the
add carbonates of potassium and magnesium, and leaves a reddue consisting of the
hydrocarbonate 3M^C0«JtfcH0 + 8a^. (Berzelius.)

BL Deville (Ann. Ch. Phys. xxxiii. 75), obtained the salt by the same process in
microscopic crystals, apparently having the form of oblique rhombic prisms. By using
sesquicarbonate of potassium instead of the diadd carbonate, he obtained, together with
the preceding, another double salt containing MgHCO' + 2 aq. The latter is obtained
separately in small rhombic prisms by digesting magnesia alba for twdve or fifteen
hours at 60^ or 70° C, with diadd carbonate of potasdum.

Carbonate of Magnesium and Sodium, M^NaCO*, is obtained in anhydrow
microscopic crystals by digesting magnesia alba in like manner with diacid carbonate o:
sodium. A mixture of a magnesium-salt with diadd carbonate of sodium yidds ni
double salt, but only Mg*CO'+ 3aq.

Cahbonj^tb of Manoanesb.— The anhydrous carbonate occurs native as Z^'-

CARBONATES. 789

aUogite, also called Red Manganese^ Hhodochrosite^ Brown S^r^ Mangantpath. It
forms rhombohedral cryBtaJs, isomorphous with calcite, in wmch the principal is to
the secondaiy axes as 0*8117 : 1* and the inclination of the faces meeting in the termini
edges B 106^ 61'. The crystals are tabidar, exhibiting the faces B . — ^B oo B . OR
It occurs also in globular.and botiyo'idal forms ; likewise granular massire ; occasionaUj
as an impalpable powder.* Specific graxity 3*4 to 3-6 ; of a variety from Eapnik, 8*592.
Hardness 3*5 to 4*5. It is transluoent, of rose-red or brownish colour, and Titreous lustre
inclining to pearly. Streak white. Fracture uneyen. Brittle. It is found in the Saxon
mines, at Nagj4y and Kapnik, in Transylvania, near Blbingcrode in the Haiz, &c At
Glendrc^ in the county of Clare, Ireland, it forms a layer of yellowish-grey colour,
two inches thick, below a bog. It also occurs in the pulverulent form, coating triplite,
at Washington, Connecticut. It is generally mixed with the carbonates of calcium
and magnesium, the proportion of carbonate of manganese Tairing firom 97 to 75 per
cent A sample from Ireland, analysed by Gruner (Ann. Min. [31 xviii. 61), gave
971 per cent Mn*CO», 0*7 Fe*CO», 10 CaH50«, 08 M§;«CO«, and 01 Mn*0«.

Aimydious carbonate of manganese may be obtained artificially as a veiy fine
amorphous, fiuntly rose-coloured powder, by heating chloride of manganese in a sealed
tube with carbonate of sodium to 160^ C., or with carbonate of calcium to 140^ — 170^
from 12 to 48 hours. (S^narmont, Compt rend, xxyiii. 693.)

By precipitating manganous salts with carbonate of potassium or sodium, a white
precipitate is formed, wmch, after washing with boiling water, and drying in vacuo
over oil of vitriol, is a snow-white tasteless powder, containing, accor£n^ to the
analyses of lire, Turner, John, and Forchhammer, 2Mn*C0' + aq. (Gnu iv. 214).
According to H. Bose (Ann. Ch. Phaim. Ixxx. 235) equivalent quantities of chloride
of manganese and carbonate of sodium yield a precipitate containing 5Mn'CO*.2MnHO.

Carl^nate of manganese, whether anhydrous or hydrated, is permanent at ordinary
temperatures, but when heated to redness in the air, assumes a dark brown colour, and
is converted into manganoso-manganic oxide. Ignited in an atmosphere of hydrosen,
it yields greenish-grey manganous oxide. Ignit^ in chlorine eas, it yields, according
to Wohler, a crystalline mixture of chloride of manganese and manganoso-manganio
oxide:

4Mn«C0« + a« - 2MnCl + 2Mn«0« + 4C0«.

Chlorine-water or aqueous h^rpochlorite of calcium converts it» first into manganoso-
manganic oxide, afterwards into peroxide. When recently precipitated, it dissolves in
ammoniacal salts. It is soluble in 7680 pts. of pure water, and in 3480 pts, of aqueous
carbonic acid. (John.)

Cabbokatbs of Mbbcubt. — Mereurie nitrate gives with neutral or acid car-
bonate of potassium or sodium, a brown-red precipitate, containing 4Hg;H).C0*, or
8HgH).HgH30* (Setter berg, Pogg. Ann. xix. 60.) From mercuric chloride, alkaline
bicarbonates precipitate, not a carbonate but an oxychloride.

Mercurous nitrate yields with carbonate of potassium, a black or yellow powder,
consisting of mercunnts carbotuUe, "HhafCO^, It is very apt to give off carbonic add ;
and the best way of obtaining it of definite composition is to mix mercurous nitrate
with a slight excess of alkaline bicarbonate, set the mixture aside for a few days, and
stir it frequently, then wash as quickly as possible, and dry in vacuo over oil of vitriol
(Setterberg, loc, cit.) It is converted into mercuric oxide by exposure to the air.
Alkalis blacken it, sepmting metallic mercury. (Gm. vL 15.)

Cabbonatb ov Mbthtl. See Cabbonto Ethsbs.

Cabbonatb of Kiokbl. — The anhydrous salt, NiK)0', is obtained by heating
chloride of nickel with alkaline carbonates in sealed tubes, in the same manner as car-
bonate of cobalt (p. 782), is a greenish-white crystalline powder, composed of minute
rhombohedrons, scarcely attacked by strong acids at ordinary temperatures.' (S6nar-
mont)

A hydroearhonaU of nickel, NiK/0'.4NiH'0*, called Emerald-nickel^ occurs in the
form of a stalactitic crust on chrome-iron ore, at Texas, Lancaster County, Pennsylvania,
also at Swinaness in Unst, Shetland. It is amorphous, with an uneven somewhat scaly
fracture. Specific gravity » 2*67 to 2*623. Hardness 3 to 3*25. Colour, emerald-
green with strong vitreous lustre. Streak green. It gives off water when heated, and
turns blackish. (B. Si Hi man, Jun. SilL Am. J. [2] vi. 248.)

Hydro-nickelma^nte, a mineral allied to the preceding, but containing oiagnesinm
as well as nickel, is found in the same localities in serpentine. (Shepard ibid, 250.)

Nickel-salts treated with alkaline carbonates, yield a pale apple-green, fiocculent
precipitate, which, after washing and drying, sometimes forms a loose, earthy, pale-
^een mass having a faint metallic lustre, sometimes, especially after continued wash*
mg with boiling water, a thick blackish-green mass, having a concho'idal wavy fracture.
The precipitates thus formed always contain water, their composition varying according

3e 3

790 CARBONATES.

to the temperatoTA, strengtli, and proportions of the aolationB employed. According to
H. Bose (Ann. Ch. Phann. Izxz. 237), the precipitate formed in the cold with sulphate
<9f nickel and neutral carbonate of sodium consists, when dried at 100° C, chicdiy of
Ni'CO*.3NiHO + 2aq. ; if boiled with a large quantity of water, it appears to take
up water and lose carbonic acid. If heated in the air above 100°, it gradually gives
on carbonic acid and water, and is partly converted into peroxide of nickel. Jhceci-
pitated carbonate of nickel does not appear to be altered by digestion with bicarbonate
of soda, even at 60° to 70°. (H. D e viUe.)

Carbonates of Nickel and Potamum, — By methods similar to those adopted with
the corresponding cobalt-salts (p. 782), Deville obtained the salt (Ni£)GO* + 2aq. in
shining apple-green microscopic needles, and (Ni'£lH)CH)* + 4aq., in light green
ciTstaJs, apparently having the form of oblique rhombic prisms. The last was aim ob-
tained by Bose.

Carbonate of Nickel and Sodium^ (NiNa)CO* + 6aq., is obtained like the cobalt-salt^
in small dystalsi which appear to be cube-like rhombohedrons. (Deville.)

GABBOiriiTBS OF Palladiux. — Ou adding an alkaline carbonate to a solution of
palladium, a light yellow precipitate is formed, at first without evolution of carbonio
anhydride ; but on continuing the precipitation, effervescence ensues, and the precipitate ^

turns brown. It retains a small quantity of carbonic add when dry. (Berselius.) '

Cabboitatbs of PoTASsirx. — Three of these salts are known, all having the
constitution of metacarbonates, vis. the dipotauio or neutral carbonate^ KH}0' or
K'O.CO', the monopotaseic or di-aeid carbonate^ commonly called bicarbonate, EHCO"
or KK).H*0.2C0«, and the tetrapotaseie or eesfU^and carbonate, K*HH}K)», or
2E70.3CO' + HK). The last has not been obtained in very definite form, and is
perhaps only a mixture of the other two.

Dipotaaeic Carbonate, OT Neutral Carbonate of Potaseium, K"CO*. Buh-
earbonate of Potash. Mild ov Aerated VegetahU Alkali, Salt of Tartar, Purified PotasK
Pearlash, Alkali vegetabile fixum, Cineres daveUati depuraii. — This salt is obtained
chiefiy from the ashes of plants. Living plants contain the potassium-salts of several
vegetable acids, acetic, malic, tartaric, oxalic, See. ; and these salts, when calcined* are
tnmsformed into carbonate, which remains in the calcined residue mixed with charcoal
and the various mineral salts contained in the plant, viz. sulphatei, chloride, and
silicate of potassium and sodium, besides carbonate of calcium and other insoluble
matters. On treating the ash with water, the carbcmate of potassium is dissolved,
together with the alkaline sulphates and chlorides, and a residue is leSt, consiHt.ing of
carbonate and phosphate of calcium, silica, clay, &c. The solution is evaporated to
dryness, and the residue is sold as crude potash. Sometimes lime is stirrod in with
the solution during the eva{X>ration, and then the carbonate of potassium is partly con-
verted into hydrate or caustic potash. The quantity of potaui obtained from diffe-
rent plants varies according to their nature, the most succulent yielding the largest
amount^ inasmuch as the alkaline salts are chidiy contained in the sap : h^ioe herbaceous
plants yield more than shrubs or trees. The different parts of the same plant also
yield diffi^rent quantities — the leaves more than the branches^ the bark more than the
wood.

The ashes of plants are used in all countries for the alkaH which they contain, both
as manure for the soil, and to yield a lye for the bleaching of linen ; but it is only in
countries where wood is very abundant, that potash can be advantageously prepared as
a commercial product. Nearly aU the potash used ia the arts oomes from America or
from Bussia.

Crude potash contains from 60 to 80 per cent, of carbonato of potassium, the re-
mainder consisting of sulphate, chloride, and smidl quantities of silicate of potasssium
together with organic matter which has not been completely burnt. This carbonate
being mucli more soluble than the other potassium-salts, may, fbr the most part, be
separated from them by digesting the crude potash for several days with ito own weight
of cold water, then decanting the liquid, quickly evaporating it, removing it from the fire
as soon as it begins to show turbidity from the formation of small crystals, and leaving it
to cool, stirring all the while to prevent the formation of large crrstals, which would
enclose mother-liquor in their cavities. The mother-liquor is then filtered ofi^ the
crystals washed with a small quantity of solution of pure carbonate of potassium, then
dried and heated to incipient redness in vessels of cast-iron, silver, or platinum. The
product thus obtained, called pear lash, contains only 2 or 3 per cent of foreign
matter, which, however, is difficult to remove.

Pure carbonate of potassium may be obtained by igniting acid tartrate of potassium
(cream of tartar) in a crucible. A black residue is thereby obtained, consisting of
carbonate of potassium and charcoal, which is often used as a reducing agent, under
the name of Aaek Htue, The carbonate of potassium is separated from uie charcoal by

CARBONATES. 791

solution in water, filtration, and evaporation. If the solution hsa a brown colour from
undeoomposed organic matter, the salt must be again ignited.

Carbonate of potassium is sometimes prepared by throwing into a red-hot iron
vessel, by small portions at a time, a mixture of 1 pt. cream of tartar and 2 pts. nitre.
The carbon of the cream of tartar is then all burnt away by the oxygen of the nitre,
and there remains a white mass called white flux, consisting almost wholly of carbonate
of potassium. It frequently, however, contains small quantities of nitrite, — ^which may
be avoided by flimiTiigliing the proportion of nitre used, — and always a little cyanide
of potassium.

Pure carbonate of potassium is, however, more easihr obtained from the add cap*
bonate or oxalate (binoxalate). The acid carbonate, KHCO*, is found in commerce in
large crystals very nearly pure. It may be further purified by recrystallisation, and,
when ignited in a platinum or silver crucible, yields the pure neutral carbonate. The
acid oxalate of potassium may be prepared by mixing hydrate of potassium with excess
of oxalic acid, and purified by several crystallisations. When ignited, it leaves pure
carbonate of potassium unmixed with charcoal. (Begnault.)

The impurities which may occur in commercial carbonate of potassium are the fol-
lowing : mlphate ofpotcusium : detected by the turbidity produced on adding chloride
of banum to the solution acidulated with hydrochloric acid and diluted. Chloride of
potassium : doud produced by nitrate of silver in the solution acidulated by nitric
acid. Phosphate of potassium : crystalline predpitate by sulphate of magnesium in
solution treated first with hydrochloric add, then with excess of ammonia. Nitrate or
nitrite of potassium : reddish brown colour by ferrous sulphate in solution of the salt
in excess of sulphuric add. Cyardde of potassium: Prussian bluc^ formed by ferroeo-
ferric sulphate and excess of hydrochloric acid. Soda : crystalline predpitate with
acid metantimonate of potassium (p. 327). Carbonate ofcalciwn : retained in solution,
parUy through the meaium of the carbonate of potassium : doud with oxalic add after
neutralisation with acetic add. Silica: remains undissolved on addulating with
hydrochloric acid, evaporating to complete dryness, and digesting the residue in dilute
hydrochloric add. Oxide of copper : red-brown predpitate with ferrocyanide of potas-
sium in acidulated solution.

Carbonate of potassium is very soluble in water, 1 pt. of the anhydrous salt dis-
solving, according to Osann, in 1-05 pt. of water at 3° C. (37-4° F.), in 0-9 pt. at 12*loC.
(54° F.), and in 0*49 pt. at 70<> C. (168° F.) The most concentrated solution, contain-
ing 48*8 per cent, of the anhydrous salt, nas a spedfic gravity of 1*54 at 15° C, and
boils at 113° C. (235'4 F.) (Dalton). It has a strong ^kaline taste and reaction, but
is only slightiy oonosive. A highly concentrated hot solution deposits on cooling
rhombic octahedrons containing 20 per cent, of water, corresponding to the formula
K«C0" + 2aq.

Both the crratals and the anhydrous salt deliquesce rapidly in the air, forming an
oOy liquid. The anhydrous salt melts at a red heat^ volatilises at a white heat. It is
not decomposed by any temperature in dose vessels ; but at a red heat^ not sufiident
to mdt it, it is puUy decomposed and converted into hydrate by a stream of aqueous
vapour or moist air ; it is not decomposed by diy air or dry hjdrogen gas. Charcoal, at
a bright red heat) decomposes it| with separation of potassium and formation of car-
bonic oxide and other products (see Potassium). The aqueous solution, containing
not less than 10 pts. of water to 1 pt. of the dry salt, is decomposed by lime at ordi-
naiy temperatures, and more quickly at the boiling heat^ the carbonic add being re-
moved and caustic potassa produced. With more concentrated solutions, the reverse
action takes place, caustic potassa abstracting carbonic add from carbonate of calcium.

Carbonate of potassium is much used in chemical manufactures, especially for the
preparation of soft soap, in ^ass making, and in the preparation of cyanide of potas-
sium, ferrocyanide of potassium, Prussian blue, &c. ; also for the prepajration of nitrate
of potasdum from the nitrates of sodium, magnesium, and calcium.

Monopotassio Carbonate, or Di-acid Carbonate of Potassium, "KHCO* •■
B?0.H»0.2C0*. Bicarbonaie of Potassa. BerthoUefs neutral Carbonate of Potassa,-^
This salt is obtained by passing carbonic add gas to saturation into a solution of 1 pt.
of the commercial neutral carbonate in 4 or 5 pts. of water. Crystals of the acid car-
bonate soon form, and may be purified by washing with a small quantity of cold water.
If a fiocculent predpitate should form at first, consisting of alumina or silica, it must
be removed by filtration. The carbonic add evolved in alcoholic fermentation, or that
which in some localities escapes from the soil, may be utilised for this purpose. A
very good way of preparing the add carbonate is to expose the mixture of neutral car-
bonate and charcoal, obtained by calcining cream of tartar and slightiy moistened with
water, to the action of carbonic acid gas ; the presence of the charcoal greatly facili-
tates the absorption of the carbonic acid. The add carbonate is dissolved out from

3b 4

792

CARBONATES,

the charcoal by boiling water and left to GzyBtallise (Wohler, Ann. Ch. Fhami. xxiv.
49). It muAt not be boiled in iron vessels, as it would dissolvB a small quantity of the
iron.

Acid carbonate of potassimn ciystallises in large rhomboidal prisms bdonging to
the monocUnic system. Batio of orthodiagonal to dinodiagonal to principal axis »
0*3734 : 1 : 0*491. Inclination of dinodugonal to principal aziB — 76° 35'. The
crystals often exhibit the faces oo P . OP . oo P ao . »P oo . + 2P oo {fig. 125), the £M:e

— P 00 frequently predominating so fsir as to obliterate
the adjacent faces. ooP : ooP » 138°. Gleavage
psiallel to 00 P 00, — P oo, and OP. The crystals con-
tain no water of ciystallisation. When neat«d to
100° C, they give off water and carbonic anhydride,
and are reduced to neutral carbonate: 2KHC0* — H-O
-(30* « K«CO«.

Acid carbonate of potassium is much less soluble in
water than the neulral carbonate. 100 pts. of water
dissolve of it| according to Poggiale :

Fig. 125.

At o°a

10
20

19-61 pts.

23-33

26-91

»»

At50°C..
60
70 .

37*92 pts.

41-35

45-24

The aqueous solution when boiled gives off carbonic add, and is gradually changed
into neutral carbonate. The decomposition is sufficiently slow to admit of the puri-
fication of the acid carbonate from a boiling solution without much loss.

It dissolves but sparingly in boiling alcohol, only indeed to the amount of 1 pt. in
1200.

The aqueous solution of add carbonate of potassium, mixed with the salts of other
metals, generally forms double carbonates (pp. 782 — 788). It does not predpitate mag-
nesium-salts in the cold, a character by which it is readily distinguished from the neutral
carbonate.

Acid carbonate of potassium is much used in chemical operations where a pure
potassium-salt is required, as it is veiy easily obtained in a pure and definite state. It
IS also used in medicine, in cases of gout and uric add gravel.

Sesquicarbonate of Potassivm 1 — ^A salt intermediate in compodtion between the two
preceding, was said by Berthollet to be obtained in crystals, by mixing 100 pts. of the
neutral with 131 pts. of the acid carbonate (1 at K«CO* wiA 2 at KHCO»), or by
heating a solution of the di-add carbonate as long as carbonic add goes off; but ac-
cording; to H. Bose (Pog^. Ann. xxxiv. 149), the bitter process yidds almost pure
neutral carbonate of potassium. The salt prepared by the first process should contain
K^H*C*0*, or 2E*0.3CO* + HH) ; but its existence does not appear to have been satis-
factorily proved.

Cabbonatb of Silvbb, A^O*, is produced by precipitating nitrate of silver
with an alkaline carbonate. It is white at first, but becomes yellow when the sofaible
salts are washed out, and blackens when exposed to light or gently heated. It dissolves
readily in strong ammonia, and the solution treated with alraoluto alcohol yidds a pre-
dpitate containing ammonia and carbonate of silv^. (Berzelius.]

At 200° C. it gives off carbonic anhydride, and leaves pure oxide of silver, which
begins to give off oxygen at 250°. By predpitating nitrate of diver with a large excess
of alkaline carbonate and boiling, a basic carbonate is obtained, having, when dried at
100°, the composition 3AgK).C0', or Ag*C0*.2Ag*0, perhaps only a mixture. (H. Bo se,
Ann. Ch. Pharm. Ixxxiv. 202.)

Cabbonatbs of SoDiuic. — ^Three of these salts are known, corresponding in
eomposition to the potassium salts.

Disodio Carbonate, or Neutral Carbonate of Sodium, Na'CO*. Subear-
bonaieof Soda. Soda. Mild mineral alkali. Alkali minerale fixum, — This salt exists in
the soda-lakes of Egypt and Hungary, and in the volcanic springs of Icdand, &c. ; it
also frequently occurs, mixed with sulphate of sodium, in the form of an efflorescence
on walls, being formed from sodium-salts oontaioed in the mortar. It is laigdy used
in the arts, and was formerly obtained from barillOj the ash of SaUola soda and other
plants growing on the sea-shore, and from the ash of sea-weed called kdp : but at the
present day, nearly all the soda of commeree is obtained from common salt^ by a process
invented by Leblanc, towards the end of the last century, and perfected by D'Anfret
and D' Areye. This process consists of three stages :

1. The convendon of chloride of sodium into sulphate by heating it with sulphurio
acidl

2. The conversion of the sulphate into carbonate by heating it in a revorbcratoiy

CARBONATES. 793

furnace with ehalk or limestone and coal. The materials are mixed in the proportion
of about 3 pts. of diy sulphate of sodium, 3 j ^ts. chalk, and 2 pts. coaL The sulphate
of sodium is reduced to sulphide, with evolution of carbonic oxide ; and the sulphide
of sodium is converted by the carbonate of calcium into carbonate of sodium and sul-
phide of calcium, which, b^ taking up lime, is for the most part converted into an in-
soluble oxjsulphide of calcium :

2Na«S0* + 3Ca*C0« + C? =- 2NaKJ0« + Ca"SK) + lOCO.

Part of the carbonic acid is, however, driven off from the lime by the heat, before it
can act on the sulphide of sodium, and consequently, the fosed mass contains, besides
carbonate of sodium, a variable but always large amount of caustic soda.

The crude soda obtained by this process, has the appearance of dark-grey, half-
vitrified balls, — hence called "black balls," — ^being brought into this form oy stirring
while in the semi-fused state. It varies considerably in composition, as the following
analyses will show, one of a sample from Caflsel analysed by Unger, another from New-
castle^ by Richardson.

Qmposition of Black BalU, or Crvde Soda,

Cusel.

Newcastle.

Carbonate of sodium . . . 23*67

9-89

Caustic soda

1112

26-64

Sulphate of sodium
Chloride of sodium

1-99

3-64

2-64

0-60

Carbonate of calcium

12-90

16-67

Oxjsulphide of calcium
Sulphide of iron .

84-76
2-46

36-67
1-22

Silicate of magnesium

4-74

0-88

Charcoal

1-69

4-28

Sand ....

2-02

0-44

Water . . . ,

210

2-17

99-78 10000

3. Purificaiion.'^The crude or ball soday after heing crushed under millBtones and
sifted, or loosened and disintegrated by hot vapour, is lixiviated with warm water, which
dissolves up the carbonate of sodium and the other soluble salts, leaving the oxysulphide
of calcium undissolved. To effect the extraction with the smallest possible quantity
of water, the crude soda is placed in perforated sheet-iron boxes, suspended just below
the surface of the liquid, and is subjected to a continuous process of exhaustion in a
series of lixiviating tanks, arranged somewhat like the pans for the evaporation of
boric acid (p. 637). Each box containing the crude soda is first suspended in the
lowest cistern, which contains a nearly saturated lye, then transferred to the next,
which contains a somewhat weaker lye, and so on tiU it arrives at the highest, into which
pure water ia admitted from a cistern. When the lye in the lowest tank is saturated,
it is transferred to the evaporating pan, its place being supplied by that in the next,
which in its turn is replaced by the third, &c. In this maimer, each portion of Hquid
gets thoroughly saturated, and the ball soda completely exhausted of soluble salts.
The concentrated solution is boiled down to dryness, and yields a salt consisting chiefly
of carbonate of sodium mixed with caustic soda and sulphide. This is called aoda-
talt.

4. To purify this product further, it is mixed with one-fourth of its bulk of sawdust,
and exposed to a low red heat in a reverberatory furnace, for about four hours : the
carbonic acid produced by the combustion of the sawdust^ then converts the caustic
soda into carbonate; also the sulphide, with evolution of sulphuretted hydrogen. This
product contains about 60 per cent of alkali, and forms soda-salt of the best quality.

6. To obtain crystallised carbonate^ the purified soda-salt is dissolved in water, and
the liquid when clarified is boiled down till a pellicle forms on the surface. The solu-
tion is then run into shallow ciystallising vessels, and after standing for a week, the
mother-liquor is drawn off, and the ciystals are drained and broken up for the market.
The ciystals thus obtained contain 10 at. of water. The mother-liquor, which contains
the foreign salts is evaporated to diyness for soda-salt.

The crystallisatioB of carbonate of sodium generally affords a safe guarantee of its
purity ; the crystals also dissolve in water mu<m more quickly than the anhydrous salt,
and are therefore more convenient for many purposes. But when the salt is required
in the anhydrous state, as for glass-making, or as a flux in metallurgic operations, or
where laige quantities are wanted, as in the soap-manufacture, the soda-salt is preferred,
as the large quantity of water in the ciystals (nearly 63 per cent) greatly increases the
cost of transport For some purposes, the crude soda as it leaves the furnace is suffi-

794 CARBONATES.

elentlT pore. In preparing it to be sold for soch puposes, snlphate of aodinm is nsed
eontaming 10 to 12 per cenl of common salt ; this remains nndumged in the soda, and
communicates to it the property of easily faUing to pieces in damp air, thus obviating
the necessity of grinding.

For farther detaiLi respeefcinff the soda-mannfiMstnre, see Miller' » Chemiitiy, toL ii ;
Ur^8 Dictionary of Arts, Manitfactures, and Minu, ilL 720; Chemieal 72»4-
nohgy, by Siehardson and Watts; Pay en, Prhis de Ckimie indusirieUe, 4"* ^
i 296.

Other methods of obtaining carbonate of sodium ftom the chloride hsre been pro-
posed, but none of them appear to be able to compete with that above described. —
1. Sulphate of iron produced by the oxidation of iron pyrites, is a cheap article, and
has been proposed as a substitute for sulphuric add in the first stage of tbe process :
sulphate m sodium and chloride of iron are formed, the latter TolatiUsing ; or the two
salts are dissolved together in water, and the solution is eo^xMed to a low temperature,
whereupon sulphate of sodium crystalliBes out, while chloride of iron remains in solu-
tion ; or the sulphate of sodium may be made to crystallise out by raising the liquor
to the boiling point. — 2. Sulphate of sodium mi^ be formed by rosjsting iron pyrites
in a reverberatory Aimace with common salt. — 3. Sulphate of sodium is decomposed by
a solution of caustic baryta or strontia, these earths being procured by decomposing
the native sulphates with steam at a red heat ; the sulphuric acid thereby set firee
might be used for converting the chloride of sodium into sulphate (Tilarhmann). —
4. Chloride of sodium is decomposed by hot steam in presence of alumma, whereby
aluminate of sodium is formed ; and tiie solution of this salt is decomposed by a
current of carbonic addgas (Tilgbmann). — 5. Ammonia gas is passed into a solution
of chloride of sodium ; tiien carbonic acid, whereby chloride of ammonium and add
carbonate of sodium are produced :

Naa + NH» + C0» + H*0 - NaHCO* + ira*CL

The add carbonate of sodium being the less soluble salt of the two, crystallises out ;
it is converted into neutral carbonate by heat, and the carbonic add evolved is used
again. The mother-liquor containing the sal-ammoniac is boiled, to drive off any car-
bonate of ammonium that it may contain, and this salt is collected ; the solution is then
boiled with lime, to liberate the rest of the ammonia. In this maimer the operation
may be conducted with but little los& (Schloessing and Boland.)

The impurities found in commercial carbonate of sodium are, stUpkLde^ ^fpostdphite,
sulphate, chloride and ferrooyanide of sodium; also potassium-salts, carbonate of
calcium, and carbonate of maanesium. It may be purified by repeated crvstallisation,
or by washing the commercial ciyBtals with cold water, dissolving them in hot water,
stirnng and cooling rapidly, to prevent formation of large ci^tals, then draining
off the mother-liquor, and washing the crystalline powder with cold water. (G^ay-
Lussac.)

Neutral carbonate of sodium in the anhydrous state, is a white powder composed of
translucent partides. It has a specific gravity of 2*4659 (K are tin). It melts at a
moderate red heat, more easily than carbonate of potassium. It is quite undeoom-
posible by heat in dose vessels, but is easily decomposed when heated to redness in a
current of steam or moist air, leas easily in a current of dry air or hydrogen (H. Rose).
It is decomposed by charcoal at a brignt red heat, yiddinff carbonic oxide and sodium.
In contact with water, it becomes heated, and forms a nydrate which dissolves. It

has an alkaline taste and reaction, but is even less caustic than
Fig. 126. carbonate of potassiimL

Hydrates. — There are several hydrates of neutral carbonate of
sodium. — 0. The ordinary crystals which separate from a mode-
ratdy strong solution at ordinaxy temperatures, contain 10 at.
(62-69 per oent) water, N.aK)0" + lOHK). They belong to the
monodinio system. Orthodiagonal: dinodiagonal : principal axis
«0-7049: 1:10452. Inclination of dinodi^nal -67 -40<^. Or-
dinaiycombination+F. oo P . [ oo P oo] (^. 126) ; ooP : ooP»
100^20'. Cleavage tolerably distinct paraUd to oo P ao, less dis-
tinct parallel to [ oo P od]. Specific gravity — 1 '423 (Haidinger).
They effloresce in moderatdy dry air, crumbling to a white powder,
and giving off 5 at. water at 12-5^0. and 9 at at 380 (S chindler) ;
9 at. also in vacuo over oil of vitriol (B lu c h er). The 1 0-hydrated
salt occurs as a natural product called natron, together with the
mono-hydrate, at the soda-lakes of Egypt and Hungarv, at Vesu-
vius, Etna, and in various parts of Asia, Africa, and America.
(Dana, ii. 455.)
a, Na*CO' + 15aq. is obtained in crystals, when a solution of the
neutral salt is exposed to a temperature of — 20^ C, and the frozen water is afterwards

CARBONATES. 795

allowed to liqnefy ; and Na^CO* + 9aq. ^7 repeatedly dygtallimng a aolation which at
first contains a portion of add carbonate. (J acquelain, Compt rend. kxx. 106.)

b. Na^CO* + 8 aq. crystaUises in right rhombic priamfl with fonr^sided anmmita, when
the 10-hydrated sut is melted and left to cool, or from a hot-satorated aqneoua solu-
tion, apparently at a temperatore lower thaji the aystalHsing point of the mono-
hydrated, and higher than that of the deca-hydrated salt. (Thomson, Annals of
Philosophy, 26, 44.)

c Ka*CO' + 7aq. — This hydrate eiystallises in two forms, (a) rhombohedral; (b) in
trimetric oystals of the same form as Thomson's salt (which, according to Loewel,
oontains, not 8 at but 7 Bt. water). When a solution saturated at the boiling heat is
enclosed in a flask, which is corked immediately after the boiling has ceased, no erys-
tals are depodted from it fbr a long time on oooUng down to between 26^ and 18^ C. ;
but on ooolinp^ below 8^ it deposits chiefly the trimetric 7-hydrated salt. Between 16^
and 10°, it yields the rhombohedral salt (a), which redissolTes between 21° and 22°,
forms again at 19°, and on cooling from 10^ to 4° becomes opaque, and passes into b.
After cooling to a lower tem^ratixre and for a longer time, when the state of super-
saturation ceases, the whole is converted into a mass of ezystals of the deca-hydi»ted
salt (H. Loewel, Ann. Gh. Phys. [8] zcdii. 834.)

d, KaKJO* 4- 6aq. crystallises from a solution of protosulphide of sodium eanosed to
the air, and frequently also from a mixed solution of carbonate of potassium and
chloride of sodium. (Mitscherlich, Pogg. Ann. -viii 441.)

«. Na'C0' + 5aq. is formed when the 10-hydrated salt effloresces at 12*6° 0.
(Sch indler), also when the same salt is melted in its water of aystallisation, and after
the mono-hydrated salt has oystallised out between 70° and 80° 0., the remaining
liquid is kept for some time at 34° ; it is also formed from the mono-hydrated salt by
exposure to the air (Berzelins). It was once accidentally obtained at the Buxweiler
soda works, in tran^)arent rhombic octahedrons, which effloresced slightly in the air,
and when dissolred in water and evaporated at 30° 0. yielded the same salt (P er s oz,
Poflg. Ann. xxiii. 303.)

/. Na*CO' + aq. is formed from the deca-hydrate by efflorescence, and is found native
as themumatrite, in the same localities as natron, and is indeed the more common salt
of the two. It forms rectangular tables of the trimetric system with bevelled edges.

The same hydrate separates from a solution of the neutral carbonate concentrated
by evaporation at the boiling heat, a circumstance which is made available in the soda
manufacture for the purification of the salt, the oystalline powder which separates
from the boiling solution being taken out and drained ; if left to cool in the solution, it
would redissolve. It does not undeigo the aqueous frision when heated, but cives off
its water and becomes opaque at 87° U. It absorbs water from moist air, and is con-
verted into the pentahyorate. In a wann atmosphere, it absorbs carbonic add and
forms sesquicarbonate,

SoltUion of Carbonate of SocUunk — ^According to Ppggiale, 100 pts. of water dissolve
of the anhydrous salt, 708 pts. at 0° C, 16*66 at 10^ 26*93 at 20°, 30*83 at 25° ,35*90
at 30°, ana 48*5 at 104*6°, which is the boiling ^int of the saturated solution. Ac-
cording to Anthon, the 10-h^drated salt dissolves m 2 pts. of cold, and much less than
1 pt of hot water. According to Loewel {loe, cit) 100 pts. of a saturated solution con-
tain of the 10-hydrated salt, 7 pts. at 0° C, 12*1 pts. at 10°, 16*2 pts. at 15°, 21*7 pts.
at 20°, 28*5 pts. at 25°, 37'2 i>t8. at 30° 5r7 pts. at 88°, and 45*5 pts. at 104°. Hence
it appears that there is a maximum solubility at 38° 0.

Solutions of carbonate of sodium are capable of assuminff the state of supersatnra-
tion, like those of the sulphate. A solution saturated at the boiling heat and imme-
diately enclosed in a sealed tube or a well corked fiask, remains supersaturated at
common temperatures, and frequently even when cooled several degrees below 0° C.
Keeping the air in contact with the h<j^uid from agitation, as by covering the hot solu-
tion with a glass shade-, is often sufficient to prevent crystallisation at ordinary tem-
peratures ; but access of air then causes immediate solidification, attended with rise of
temperature. The supersaturated solutions, as already observed, depodt the 7-hy-
drated salt in two different modifications, according to temperature (trid. sup.)

Monosodio Carbonate^ Di-aeid Carbonate of Sodium, Bicarbonate of Soda,
NaHGO' or Na'0.H'0.2C0'.— This salt exists in solution in alkaline mineral waters.
It is prepared : 1. By passing carbonic add gas into a solution of the neutral carbo-
nate as long as it is absoroed. — 2. By expodng the effloresced neutnd carbonate
placed on trays in a wooden case to an atmosphere a£ carbonic add. — 8. By adding
commercial carbonate of ammonia (which is chiefly bicarbonate) to an equal weight of
chloride of sodium, dissolved in three times its wdght of water, stimng the whole
well together, and leaving it to stand for several hours. Monoeodic carbonate then
separates in crystalline grains, while chloride of ammonium remains in solution (p. 794)

Naa + NH^H.CO« - NaHCO* + NHH3L

796 CARBONATES.

The precipitate is separated from the liquid by preasuie in a screw press, but it
always retains a portion of chloride of sodium.

Monosodic carbonate crystallises in oblique four-sided tables, and is sometimes ob-
tained by the first method in ciystals of considerable size ; the second and third
methods yield it in the form of a crystalline powder. It has a slight alkah'ne taste and
reaction, and is permanent in dry air at ordinary temperatures. At a red heat^ it gires
off water and carbonic acid, and is reduced to anhydrous neutral carbonate.

100 pts. of water dissolve of monosodic carbonate, 8*95 pts. at 0^ C, 10*04 pts.
at 10° 11-15 pts. at 20<5, 12-24 pts. at 30°, 14-46 pte. at 40°, and 16-69 pts. at 70°
(Foggiale). The solution gives off carbonic acid slowly at ordinary temperatures,
more quickly at 70° C, rapidly at the boiling heat, and is ultimately reduced to neu-
tral carbonate. It does not precipitate magnesium-salts in the cold, but at the boiling
heat carbonic acid escapes and a precipitate of carbonate of magnesium is formed ; this
character distinguishes it from the neutral carbonate. Acid carbonate of sodium is used
for thepreparation of effervescing powders, and asaremedy in certain calculous disorders.

Tstrasodio Carbonate or Seaquicarbonate of Sodium, Na^H'CW +
2aq. B 2NaH).H'0.3CO^ + 2aq. — This salt, which may be regarded as a com^und
of the mono- and di-sodic carbonates (2NaHC0' + Na^O'), is found in Africa, in the
province of Sakenna, two da^' journey from Fezzan, where it is called irona ; it
occurs at the foot of a mountam, forming a crust, varying in thickness frY)m an inch to
that of the back of a knife ; also as urao at the bottom of a lake in Maracaibo, South
America ; efflorescences of it occur also near the Sweetwater Biver, Bocky mountains,
mixed with sulphate and chloride of sodium (Dana, iL 454). It is produced artifi-
cially : 1. By mixing the mono- and di-sodic carbonates in the proportions above indi-
cated, melting them together, drying, and exposing the dried mass to the air of a
cellar for some weeks ; it then absorbs water, becomes crystalline, and contains spaces
filled with shining crystals of tetrasodic carbonate. From a hot solution of mono- and
di-sodic carbonates, the two salts crystallise out separately on cooling (Hermann,
J. pr. Chem. xxvi. 312). — 2. A solution of the monosodic salt, concentrated by boiling,
but not boiled long enough to reduce it to the disodic salt> deposits the tetrasodic salt
on cooling. — 3. If 4 oz. of alcohol be poured on the top of a solution containing 100
grains of the disodic and 152 grains of the crystallised monosodic carbonate in 4 oz. of
water, fine clear needle-shaped crystals of the tetrasodic salt form, after some days, at
the surface of separation of the two liquids, while at the bottom of the solution, large
ciystals of the disodic carbonate are found covered by a crust of the monosodic salt.
(Winckler, ChndirCa Handbook^ iii. 83.)

The crystals of the native salt belong to the monocUnic system. Orthodiagonal :
clinodiagonal : principal axis » 0*3552 : 1 : 1*282. Inclination of clinodiagonal to prin-
cipal axis ss 53° 50'. Observed combination oo F . oF . + F oo, prismaticidly elongated
in the direction of the orthodiagonaL oo F : oo F » 132° 30'. Cleavage very p^ecti
parallel to + F oo. They are colourless, transparent^ or translucent, with vitreous
lustre. Specific gravity 2*112. Hardness 2*5 to 3. Structuro foliated, radiating;
fracture conchoidaL The artificial crystals are small, and of the same form as the
native crystals. The salt has an alkaline taste and reaction, and is not efflorescent^
At a red heat, or when its aqueous solution is boiled for many hours, it is reduced to the
neutral carbonate. It is intermediate in solubility between the two preceding salts.
According to Foggiale, 100 pts. of water dissolve of it, 12*63 pts. at 0° C, 18*30 pts. at
20»; 38-95 pts. at 40°; 29*68 pts. at60°; 35*80 pts. at 80°; and 4 1-59 pts. at 100°. The
solution is not rendered turbid by 1 pt. of sulphate of magnesium dissolved in 10 pts.
of water. Evaporated in vacuo over oil of vitriol,, it yields a mass of crystals composed
of the mono- and di-sodic carbonates together. (H. Bose, Fogg. Ann. xxxii. 160.)

Carbonate of Sodium and Potaesium, KKaCO* + 6aq. — Separates from
a solution containing equivalent quantities of the component salts, in monodinic crystals
exhibiting the faces ooF . ooFoo . [ooFoo] . ooF2 . [ooF2] . OF . + F . + F2 . +
F 00 . + 2F 00 [F oo] . + 2F 00. Inclination of &ces ; ooF : ooF in the clinodiagonal
principal section = 108° 34'; OF: ooFoo « 131° 48'; OF : ooF - 122° 46'; OF:
+ Poo « 124° 48'; OF: + 2Foo = 84° 19' (Marignac, Compt. rend. xlv. 650).
Nearly the same angular values wero observed by S^narmont. The crystals are per-
manent in the air. A salt containing £?NaH}'0* + 18aq. is mentioned by Margue-
ritte (Ann. Ch. Fharm. Ivi. 220) as crystallising from the mother-liquor of ferro-
cyanide of potassium, and from a concentrated solution of the simple salts ; but
Marignac was not able to obtain this compound, and is of opinion that the formula is
deduced from an incorrect analysis.

A mixture of the neutral carbonates of sodium and potassium in equivalent propor-
tions, foses at a much lower temperature than either of the salts separately, doubt-
less in consequence of the formation of the double salt Such a mixture is very useful
in the fusion of silicates, &c

CARBONATES. 797

Carbonate of Sodium and Ca/ciMw, CaNaCO* + 6 aq.— Occurs abnndantlj, as
Gaj-Lussite, at Lagunilla near Merida, in Maracaibo, covering urac ; found also at
Sangerhausen in Thuringia. The crystals are monodinic. Inclination of axes
« 78^ 27' ; ooP : ooP = 68° 50'. Cleavage perfect parallel to ooP : less perfect
parallel to OP. They are yellowish-white, translucent^ double refracting, extremely
brittle, with conchoidal fracture, and exhibit a vitreous lustre on the broken surface.
Specific gravity » 1*92 — 1*99. Hardness » 2~3. The mineral decrepitates when
heated, and becomes opaque from loss of water. In the hydrated state it dissolves
sparingly in water, without decomposition ; but the anhydrous salt is resolved by water
into carbonate of sodium and carbonate of calcium. Ciystals of Gay-Lussite, altered
to calcite, are sometimes called natrocaleite, (Dana, ii. 453).

The s^t maybe prepared by fusing the anhydrous carbonates of sodium and calcium
together in atomic proportions.

The double salts of carbonate of sodium with other metals, magnesium, cobalt,
zinc, &c., are described with the carbonates of those metals.

Casbonatb of Stbontium. Sr^CO*. — Occurs native as Strontianite^ at
Strontian in Argyleshire, where it was first observed; also in Yorkshire, at the Giant's
Causeway, at Clausihal in the Harz, at Braunsdorf in Saxony, Leogang in Saltzburg,
and other localities. It forms ciystals of the trimetric system, isomotphous wim
arragonite and witherit«. Batio of brachydiagonal to macrodiagonal to principal
axis a 0'6026 : 1 : 0*7237. The crystals are often prismatic from predominance of
the faces ooP . oo {^ oo and r oo. Cleavage tolerably perfect parallel to ooP, less per-
fect parallel to 2f^ co. Specific gravity 3*605—3*713. Hardness 3*5 to 4. Colour
white with various shades of grey, green, yellow, and brown. Streak white. Lustre
vitreous. Transparent or translucent. Fracture uneven. Brittle. Before the blow-
pipe it melts on the edges and swells up, emitting a brilliant light, and when strongly
heated in the reducing flame, imparts to it a reddish tinge. Strontianite occurs
altered to ccelestine by the action of soluble sulphates. Baryto^trontianitet from
Stromness in Orkney, appears to be a mechanical mixture of the carbonates of stron-
tium and barium.

Carbonate of strontium obtained by precipitation is a white substance, smooth to
the touch and has but little cohesion. It dissolves in 18045 pts. of cold water, and in
56545 pts. of water containing ammonia or carbonate of ammonium (Fresenius^ ;
in 300,000 pts. of water, whether cold or hot (Bineau, Compt. rend. xli. 509); in
833 pts. of water saturated with carbonic acid at \(P C. (Lassaigne), and in this
state it occurs in some mineral waters, whence it crystallises by evaporation in needle-
shaped crystaU. When heated in close vessels, it does not give off carbonic anhydride
at any temperature short of that of a forge fire ; but in a stream of aqueous vapour or
moist air, the decomposition takes place at a lower temperature, with formation of
hydrate of strontium. It is not decomposed by solutions of alkaline sulphates at
any temperature. (H. Bos e, Pogg. Ann. xcv. 284).

Cabbokatb of Thobinum. — Alkaline carbonates, added to solutions of thori-
num-salts, throw down a basic salt, with evolution of carbonic acid. Moist hydrate of
thorinum absorbs carbonic acid from the air. The anhydrous earth is not soluble in
water containing carbonic acid. (Berzelius.)

CA.BBONATBS OF Ubaniux. — Theso sslts do not appear to exist in the separate
state. AUcaline carbonates throw down from uranous chloride a precipitate of
nranous hvdrate ; from uranous sulphate, a basic sulphate ; from uranic salts, precipi-
tates consisting of double carbonates.

Ammonuhuranic Carbonate, 2[(NH*)»0.C0«] + U*0".CO« or Carbonate of Xlranyl^

and Ammonium^ /tjsqns [ C^O'. — On digesting the precipitate thrown down by ammonia

or carbonate of ammonia from a uranic salt in a solution of carbonate of ammonia
at 60^ — 80^ C, till the L'quid is saturated, then filtering hot, and leaving the filtrate
to cool, this salt separates in small transparent yellow crystals. It decomposes
slowly in the air at common temperatures, more quicklv when heated, ultimately leav-
ing a residue of brick-red uranic oxide. It dissolves in 20 pts. water at 15° C, more
easily in water containing carbonate of ammonia. The solution, when boiled, gives
off carbonate of ammonia, and deposits the whole of the uranium as a yellow precipi-
tate, consisting, according to Arfvedson, of uranic oxide with small quantities of am-
monia and carbonic acid ; according to Pdligot, of uranate of ammonium ; according
to Ebelmen, of uranic hydrate containing 2 per cent ammonia, but no carbonic acid.
(Ebelmen, Ann. Ch. Phys. [3] v. 189; Delffs, Pogg. Ann. Iv. 229.)

Potassio'ttranic Carbonate, k*(U*0)''C'0*. — Obtained by dissolving in acid carbonate
of potassium the precipitate thrown down from uranic salts by the neutral carbonate,

* Uranyl, U^O, \% a mnn.ifnnitc radiclo which maybe luppoied to exist in the uranic said, €^» uranle
niitate, U*OS N«0^=(UaO)NO\ (Sec Uranium.)

798 CAKBONATES.

evaporating at a gentle heat» and reeryBtallifling. It forms a bright- yellow crystalline
crast, which gives off carbonic anhvdride at 300^ C, and when heated to redness leaves
a red-brick mixture of uranate and carbonate of potassium. It dissolves in 13*6 pts.
of water at 16° G. without decomposition, but is partially decomposed by boiling water,
which throws down uranate of potassium. The same compound is deposited after a
while from a cold solution of the double carbonate, ifveiy dilute and not oontainingexoess
of carbonate of potassium. Caustic potash precipitates the whole of the uranium as
uranate of potassium, even in the presence of a large excess of carbonate of potassium.
Acids, if not added in large excess, poduce the same light yellow precipitate as is
produced by carbonate of potassium m uranic salts. The double salt is insoluble in
alcohol. (£1 b el m e n, loc, aU.)

Sodio-uranio Carbonate, Na*(U*0)K?0'. — Prepared like the preceding, which it re-
sembles.

Calcuxuranie Carbonate^ Oa^T7*0)CO' + 10 aq. — Found native as lAdngite^ in
amorphous rounded masses, havmg a distinct deavage in one direction, transparent,
of a beautifial apple-green colour, and vitreous lustre on the fractured suz&oe. Hard-
ness 2 to 2*5. Gives off water when gently heated and turns blackish-grey ; does not
fuse at a red heat, but turns blad:, and acquires an orange-red colour on cooling.
Occurs, with Mec|jidite, near Adzianople, also at Johanngeoigenstadt, and in the
JoachimsthaL (J. L. Smith, Ann. Ch. Pharm. Ixvi 258.)

A caloiO'Uranou9 car^ono^ C^UCO' + faq., occurring in siskin-green scaly aggrega-
tions on pitch-blende at the JBUias mine near Joachimsthal, has been examined by Yogi
and Lindacker (Jahrb. k. k. geoL Beichsantalt, iv. 1853, 221). A carbonate of ura-
nium, copper, and calcium, called Voglite, which maybe regarded as an orthocazbonate
(n^Cu*Ca'H')CK)*'+10aq., occurring in the same locality in i^ggregations of green
dichroic, dystalUne, pearly scales, has also been examined by lindai^Ler {}oc, cU.)

GARBOirA.TB OF Yttaitk, Y^CO' (containing also erbium and terbium). — Precipi-
tated from yttrium-salts by carbonate of sodium, with 13 at. water in the cold, with
2 at. at the boiling heat It is not easily decomposed by heat ; dissolves sparingly
in water containing carbonic acid; decomposes ammoniacal salts and dissolves in Uie
liquid. Its solution in carbonate of ammonia deposits, after atime^ if concentrated, a
white crystalline double salt, which does not redissolve in carbonate of ammonia.
Carbonate of yttrium dissolves also^ though less easily, in the carbonates of potassium
and sodium. (Berzelius.)

Casbomatbs of ZiNa — The neutral earbonatef or Tnetacarhonaie^ Zn*CO', occurs
native as calamine (p. 713). It is doubtM whether this anhydrous salt can be ob-
tained by precipitation. According to Schindler (GhneHn's Handbook, v. 16) it is
produced by precipitating a solution of 1 at sulphate of zinc in 10 pts. water with
1 at. diacid carbonate of potassium or sodium ; but, according to Berzelius, the precipi-
tate thus formed is ZnHX)*.3ZnH0.

8Zn«0.C0« + 3aq., or Zn*C0».4ZnH0 + aq. It is dull and opaque, with white, gr^sh,
or yellowish colour, and makes a shining streak. Specific gravity « 3*58 to 3*6. Hard-
ness a 2 to 2*5 (Gm. vi. 15). AurichaUsUe^ or green caStmine (p. 476), found in the
Altai, and at Matlock in Derbyshire, may be regarded as Zn*G0*.3iUQH0, in which
the 2dnc is partly replaced by copper. JSuraiite (p. 686) is a hydrocarbonate of sine
containing copper and caldum, perhaps a mixture.

The precipitates formed by alkaline carbonates in solutions of zinc-salts, all appear
to contain water, their constitution vaiying with the strength and temperature of the
solutions, and with the nature and proportion of the precipitant. The results obtained
in individual cases are variously stated by different authors ; those obtained by H. Bos e
(Pogg. Ann. Ixxxv. 107 ; Ann. Gh. Pharm. Ixxxiv. 210) are as follows :

a. With 1 at Sviphate of Zine and 1 at. Neutral Carbonate of Sodium, — ^When the
solutions are cold and concentrated, the precipitate consists mainly of Zn'GC.SZnHO
|m., it remains unaltered at 60° G., but, after drying at 100°, is composed of
2Zn*GO'.7ZnHO + |aq. Very dilute cold solutions and concentrated boiling solutions
yield a precipitate consisting mainly of ZnK)0'.2^iH0, or Zn*HGO\ combined with
variable quantities of water.

b. With excess of Neutral Carbonate of Sodium. — ^The precipitate from cold solutions
contained, when dried at 100° G., 5ZnK?OM8ZnHO ; from moderately warm solutions
3Zn«GOM0ZnHO (at 100°), but if very large quantities of liquid were used, it con-
sisted of Zn2GO».2ZnHO.

e. With 1 at. Sulphate of Zine and 1 at. Acid Carbonate of Sodium. (NaHCO*),—
The predpitates contain more carbonic acid than the preceding. When they are dried

CARBONIC ETHERS. 799

In Tacno, a large quantity of eazbonic add escapes, and there remains the compound
Zn«C0».3ZnH0 + aq.

d. With exeets of Acid Carbonate of Sodium. — From cold solutions a precipitate was
several times formed containing 2Zn*CC)*.6ZnHO + ^aq. (at 100^). A precipitation
on the large scale, with rather warm solutions, yieldea Zn'CO'.ZnHO. The precipi-
tate obtained with cold solutions, after standing for some time, had, when air-dried,
but not washed, the composition 8(2ZnK;0'.ZnHO. + {aq. ; after drying at 100°, it
became 2ZnH:;0*.ZnH0.

«. With excess of Add Carbonate of JPotaenum, — ^The precipitate not washed, but
dried between filtering paper, had the composition 2Zn'C0* + 2HK). After washing with
cold water and drying in the air, it became 4Zn*00' + 5aq. ; at 100° it was r^uced
to 4Zn*C0» + aq. ; and at 200° to 5Zn»C0« + aa.

According to Schindler, basic salts having the composition SZn^O.CO' + 2aq., or
Zn"CO«.7Zn«0.2H«0 and ^ZxiK>,C0\2W0, or ZnK)0".3Zn«0.2HK), are obtained by
precipitating the corresponding sulphates of zinc with carbonate of sodium. Accord-
ing to Bouasingault, ordinary sulphate of sine precipitated with sesquicarbonate of
sodium at ordinary temperatures, yields the salt 2Zn*0.C0' + 2aq., or Zn^CO^ + 2aq.
According to Schindler, hot solutions of these salts yield a precipitate of the same
composition as sin&-bloom. (Gul v. 15.)

All the hydrocarbonates of zinc give off their water and carbonic anhydride at
200° C, and are reduced to zinc-oxide, Zn*0. The native carbonate remains unaltered
at 200°, but slowly gives off carbonic anhydride at 300°. (H. Bose.)

AmTJumio-carbonate of Zinc^ NH'.2^K)0*, or CarboruUe of Zinc and Zine-ammonium,

Zn NH*Zn C ^* — ^®P^^^ ^ oystals from a solution of precipitated carbonate of zine

in a strong solution of carbonate of ammonium. (Fa vre, TraiU de Chime par Pelouze
et Frhny, 2" M. iii. 47.)

Carbonate of Zinc and Potaeeium. (Zn»rK«H«)C"0" + 7aq.— Deposited in crystals
from a solution of chloride of zinc mixed with sesquicarbonate of potassium. (D e v i 1 1 e,
Ann. Ch. Phys. [8] xxxiiL 75.)

Carbonate of Zino and Sodium, (Zni^a*)C"CH' + 8aq.— Small shining ciystals,
apparently teteihedrons and octahedrons, obtained in like manner. (Beville.)

Cabbonatb of ZiBCONiuic. Solutions of zirconium-salts, treated with excess
of alkaline carbonate, yield a precipitate soluble in acid carbonates of alkali-metal, and
containing, according to Hermann, 76*6 per cent, zirconia and 20*39 per cent, water,
agreeing with the formula 2Zi^0'.C0* + 6aq. According to Klaproth, nowever, it con-
tains 51*5 per cent., and, according to Yauquelin, 66'6 per cent, zirconia.

CARSOVZO AOXB and JkMBLYWaXDM, See Gabbon, Oxidbs of (p. 770).

OASaoVXO JKTMMMB* Carbonates of Aloohol-radicUs, — ^These compounds are
metacarbonates, M'CO*, in which one or both atoms of base are alcohol-radicles.
Those which contain 2 at. of alcohol-radicle, the neutral carbonic ethers^ are obtained :
1. By the action of carbonate of silver on the iodides of the alcohol-radicles. — 2. By
the action of potassium or sodium on the corresponding oxalates. This reaction is
attended with evolution of carbonic oxide, and probably takes place in the manner
represented by the following equation :

2(c«H»)H?o* + b:« - {cmyyco^ + 2C«h*ko + sco.

Oxalate of ethjl. Carbonate of Bthylate of

ctbyl. potaMlum.

3. By the action of water on the chlorocarbonates of the alcohol-radicles (produced
by passing oxychloride of carbon into the alcohols), and by the dry distmation of
these same products. In presence of water, the action is such as is represented by
the equation,

2(^,1 2,^ + H*0 - (0»H»»)*CO» + C0« + 2Ha

A. 'ir^ Carbodata of

Chiorocarbo- amyl.

nate of amf 1.

The decomposition of the chlorocarbonates by dry distillation is more complicated,
a considerable quantity of charred matter remaining behind ; but the principal reaction
is doubtless the splitting up of 2 at of the chlorocarbonate into a carbonic ether and
oxychloride of car Don, e, g, :

2(cao».c»H»») » (c»H»»)*co» + coa*.

The neutral carbonic ethers are ethereal oily liquids, insoluble in water, soluble in
alcohol and ether. They are decomposed by alcoholic potash, yielding carbonate of
potassium and the corresponding alcohols. Two volumes of the vapour of each of these
ethers contain two volumes of alcohol-radicle, a fact which tends to establish the dibas-
icity of carbonic acid. (See Acids, p. 46.)

800 CARBONIC ETHERS.

The acid carbonic ethers (carbonates of alcohol-radidea and hydrogen) are not
known, bat some of their salts have been prepared.

Cabbonath op Alltl. C»H'»0» «= (C»H*)«CO».— Obtained by the adion of
iodide of all^l on carbonate of silver ^eise, Ann. Ch. Pharm. xcvL 361), or of potas-
sium or sodium on oxalate of allyl (Oahours and Hofmann, Phil Trans. 18^7, p.
656), It is an ethereal liquid lighter than water. The alcoholic solution treated with
hydrate of barium, yields carbonate of barium and allyl-alcohoL

Cabbonatb of Akyl. C"H«0»= (C»H»)«C0"— Prepared: 1. By saturating
amylic alcohol with ozychloride of carbon, decomposing the product with water, treat-
ing it with oxide of lead to remove chlorine, diying over chloride of calcium, and rec-
tifying (Med lock, Chem. Soc. Qu. J. i. 368). — 2. By decomposing oxalate of amyl
with potassium or sodium. The action begins immediately, but heat is required to
complete it. By distillation, a yellow liquid is obtained, whidi begins to boil at 130^ C,
yielding amylic alcohol ; afterwards carbonate of amyl passes over at 225^, the quantity
amounting to about three-fourths of the original distillate. The residue contains a
strong-smelling viscid matter. (Bruce, Chem. Soc. Qu. J. v. 132.)

Carbonate of amyl is a colourless liquid, having an agreeable odour, and specific
gravity = 0-9144; it boils, at 224°— 226° C.

Cabbonath of Ethyl. Carbonic Ether, C»H'«0« = (C''H»)H)0«.— This ether
is prepared : 1. By the action of potassium or sodium on oxalate of ethyl, the materials
beingheated in a retort to 130^ C, and fresh potassium or sodium added, as lon^ as car-
bonic oxide continues to escape. On cooling the residue and treating it ynm water,
carbonate of ethyl rises to the surface : it is dried with chloride of calcium, and rectified
over a small quantity of sodium, then heated alone tiQ the boiling point becomes
stationary, the portion which afterwards passes over being collected apart (Ettling,
Ann. Ch. Pharm. xix. 17). — 2. By distilling a mixture of ethyl-carbonate and ethyl-
sulphate of potassium. (Chancel, Compt rend. xxxL 521.)

C*R\K.CO* + C*H» KSO* - K«SO* + (C*H")«CO«.

Carbonate of ethyl is a colourless limpid oil, having a sweet ethereal odour, and
burning taste. Specific gravity » 0*975 at 19° C. Boils at 125°, and volatilises without
decomposition, vapour-density » 4*243 (Ettling) ; 4*09 (Cahours); by calculation

for a condensation to 2 vol it is 5 x 0*0693 =s 4*089. It is inflammable,

And bums with a blue flame. It is insoluble in water, but dissolves easily in alcohol
and ether. With alcoholic potash, it ;pelds alcohol and carbonate of potassium. Heated
with sodium, it gives off carbonic oxide, and forms etliylate of sooium, together with
carbonate (?) (Lowig, Pogg. Ann. L 122). The reaction is perhaps : C*H»*0» + Na-
2CH*NaO + CO (Gm. ix. 393). Chlorine decomposes carbonate of ethyl, abstracting
hydrogen, and fbrming the two following substitution-products :

Tetrachlorocarbonic Ether^ C*H'C1*0', commonly caRed Bichlorocarbontc ether,
— Obtained by passing chlorine through carbonate of ethyl in difilised daylight, heat-
ing the liquid to 70° — 80° C. in the latter part of the process, and expelling Qie excess
of chlorine by a stream of carbonic anhydride. It is a colourless liquid having a sac-
charine odour, much heavier than water, and insoluble therein ; soluble in aloohoL It
is decomposed by dry distillation. (Cahours, Ann. Ch. Phys. [3] ix. 201.)

Perchlorocarbonio ether^ C*C1"0". (Cahours, loc. cit. ; Malaguti, Ann. Ch.
Phys. [3] xvi. 30.) — ^Produced by the continued action of chlorine on the preceding
compound in direct sunshine. The resulting crystalline mass must be purified by
pressing it between folds of bibulous paper, washing it rapidly with small quantities of
ether, again pressing, and leaving it for some days in a dry vacuum. It cannot be
purified by crystallisation from alcohol or ether.

It is a white mass, composed of small needles, and having a faint odour; melts
between 86 and 88° C, and solidifies between 65° and 63°. At a higher temperature
it partly distils unaltered, and is partly resolved into carbonic anhydride, chloride of
trichloracetyl, and trichloride of carbon : •

c*ci"o« - co» + c»a«o.ci + CHa*.

When dissolved in alcohol, it changes to an oil which is a mixture of carbonate and
trichloracetate of ethyl, a large quantity of hydrochloric acid being produced at the
same time :

eOl"0" + 4C«H«0 = (C»H»)«CO« + 2(C»H».C«a»0«) + 4HC1.

Heated with potash-lev, it yields formate, chloride and acid carbonate of potassium,
together with hydrochloric acid :

C»C1"0» + lOKHO - 2CHK0« + 6KCI + 6BCi + 3KHC0».
With gaseous ammonia^ it forms sal-ammoniac, chlocarbetbamide (trichloracetamide,

CARBONITROTOLUTLIC ACID. 801

aceording to Gerhardt^ DraiU, i 16*6), and an nnknovn substance, which erystalliBes
in long needles (Hala^nti). When thrown into aqueons ammonia, it makes a hissing
noise,Bke red-hot iron in water, and forms trichloraoetamide, together with carbonate,
formate, and chloride of ammoninm, and probably also other ammoniacal salts. (Ma 1 a-
gntL)

CABBOirA.TB OF Ethti. ahd PoTASsiuiL Etkyl-oarbonate OT Carbovinate of
of Potasnum, C^*EO* - C^*.KCO'. (Dnmas and P^ligot, Ann. Ch. Phys. [2]
iaiY, 6.) — ^Obtained hj passing carbonic anhydride into a solution of perfectly dnr
hydrate of potassinm in absolute alcohol, the liquid being carefully kept cool, which
is best effected by introducing from time to time small portions of anhydrous ether.
A crystalline deposit then forms, consistiiu; of ethyl-earlx>nate of potassium, together
with neutral and add carbonate. The ethyl-carbonate is formed as represented by
the equation :

C«H«0 + KHO + C0« - 0»H».KCO» + HK);

the add carbonate results from the action of the water thus formed on a portion of the
ethyl-carbonate, and the neutral carbonate from that of the excess of potash on the
add carbonate. To separate the ethyl-carbonate, the mass is treated with an equal
yolume of ether, which dissolves the excess of free potash, and leaves the two other
salts undissolved : the ethyl-carbonate is then dissolved out by alcohol, predpitated by
ether, and rapidly dried. It might doubtless be more easily prepared from anhydrous
ethylate of potasnum, OWKO.

Ethyl-caroonate of potasdum is a white nacreous salt, which bums with flame on
platinum-foil, leaving a carbonaceous reddue, and yidds by distillation an inflam-
mable sas, a small quantity of ethereal liquid, and a reddue of carbonate mixed with
diarcou. Water transforms it into alcohol and add carbonate of potassium :

0«H».KCO» + H«0 - C«H».H.O + KHCX)».

Etkyl-carbimio acid, CH'.H.CX)', has not yet been obtained; ndther has Carbonate
of methyl, {CB*yCO\norMetJ^l'oarbome acid, CH'.H.CO*.

CABBOiraTB OF Mbtktx. and Babiuk. Methyl^earbonate of Barium.
GH'3a.C0' (Dumas and Piligot, ioe. city^A solution of anhydrous baryta in an-
hydrous methylic alcohol, subjected to the action of carbonic anhydride, yidds a white
prec^tate, which after washing with methylic alcohol, consists entirdy of methyl-
carbonate of barium :

CEP.BLO + BaH) + C0« - CH».Ba.CO» + BaHO.

The salt is insoluble in methylic or ethylic alcohol, but dissolves easily in cold water.
The solution soon however becomes turbid, depositing a condderable quantity of car-
bonate of barium and givins off carbonic anhydride. The action is greatly assisted
by a gentle heat, and at the boiling-point it is instantaneous.

Cabbokatb of Mbthtl and Ethtl. C*H"0» - CH».C*H».CO« (Chancel,
Compt rend. xxxi. 521). — Obtained by distilling a mixture of methyl-carbonate and
ethyl-sulphate of potassium :

CH».K.CO« + C«H».K.SO« - KWO* 4- CH«.C«H».CO«.

Cabboitatb of Phbxctl andHtdboobn. CH*.H.C0*. — Salicylic add (9. v.)
Aay be regarded as constituted in this manner. When subjected to dry distillation,
it splits up into carbonic anhydride and hydrate of phenyL

Cabbonatb of Tbtbtl. Carbonate of ButyL C»H»0» - (C*H»)*.00».— Pro-
duced: 1. By the action of iodide of tetryl on carbonate of silver, the materials
(12 grammes of each^ bein^ endosed together in a sealed flask, and heated for two days
in the water-bath,— distilling the product, collecting apart that which passes over above
I8OO C, and rectifying (Ph. de Clermont, Ann. Qi. Phys. [3] xliv. 336).— 2. By the
action of chloride of cyanoeen, either gaseous or liquid, on tetzyUc alcohol, in presence
of water. (Hum a n n, ibid! xliv. 340) :

2(C«H»Ja.O) + CNa + HK) - (C«H»)«CO» + NH*CL

It is a colourless limpid liquid, lighter than water, and having an, agreeable odour like
that of carbonate of ethyl. It Iwils at 190^ C. Aqueous ammonia converts it into
tetryHc alcohol and carbonate of tetryL

GAXBOWITBOTOIi'nxXO AOIBf also called Nitrodraeylio acid.^^An add
crystalUsing in white dender needles, obtained by treating toluene with excess of strong
nitric add. G-lenard and Boudault (Compt. rend. xix. 606)t who discovered it,
assigned to it the formula CH'NO* ; it is more probably isomeric with nitrotoluylio
add, C*H*NO*; or perhaps, as suggested by List (Gm. ziii 24), the product was
merely nitrobeniois add containing nitros^poL

Vol. L 3F

802 CARBONYL— CARB0V3NIC ACID.

CO. — ^The diatomie ndiele of the carbonates, carbamatea^ eaxba-

mides, &c.

OASSOFTBaoUO ACIB. 0»H»NO« - ^^H«(0^0)'') q (Schwanert,

Ann. Oh. Pharm. cxiy. 63.)>-An amic acid, obtained by heating Malagoti'a pyronraca-
mide, C*H«NK) (^.v-), vhich Schwanert regards as carbopyirolinidei, N*.H*5[C»BP0)'',
with baiyta-water in sealed tubes. Ammonia is then formed, to^ietfaer with carbMryno-
late of barinm, OH^BaNO^ which ctrstaUises in nacreons lamin», and is not decom-
posed by heating with ^tash-lej. The oonoentrated aqneoos solution treated with
hydrochloric acid, depoeitB carboj^ynolic add as a white er^rstalline precipitate. The
ieadsalt, 0*HfPbK0^ forms sparingly soluble nacreous laminaB.

When the aqueous solution of carbopynolic acid is heated to 60° C. or aboye, pynol,
C^H'N, separates firom it as a brown nocculent substance.

CASBOSTnUEA. CH^O « N((^H')(CO)''.--Ptodnced by the action of sul-

5 hide of ammonium on nitrocinnamic add. Probably an add, CH'NO', is first pio-
uced and afterwards oonyerted into carbostyril by loss of 1 at water, thus :

C»H*(NO«)0« + 2BPS = C»H»NO» + 2H*0 + S«
Mitrodnnamie

Mid.

and C»HWO*-HH)-C«HWO.

CarbMtyrlL

The liquid is supersaturated with hydrochloric add, filtered, and eyaporated. It then
deposits crystals of carbostyril, coloured brown by a resin, which may be remoyed by
reciystallisinff the product seyend times from boiling wat^.

Carbostyril forms beautiful colourless silky needles, moderately soluble in boiling
water, easily in alcohol and ether ; melts when heated, and at a higher temperature
sublimes in shining needles ; dissolyes in hydrochloric add, also in boiling potash,
not in ammonia or in sulphuric add. Heated with solid potash, it yields an oil which
appears to be a peculiar alkaloid (OflrN ?) Boiled with oxide of silyer, it ibnns a
compound insoluble in boiling water, from which it is s^arated by adds in its original
state. (Chiosaa, Compt rend. xKxiy. 698.)

OAmBOTBZJLCBTOWnra. Ci*H*>N^.— The sulphydrate of this base is de-
posited in yellow eiystals on mixing acetone with ammonia and sulphide of carbon :

ZCm.H> + CS« + 2NH» « C>»H>«N«S« + 8HK).

(Stadeler, Pharm. Centr. 1863, p. 433; see also Acstons, p. 28.)

OAXBOTHZAJUDOrB. C'H'^N'S'.— A colourless oystalline body, produced by
adding sulphide of carbon to an alcoholic solution of aldehyde-ammoniflk It is inso-
luble in cold water and in ether, spaxingly soluble in cold alcohol, easily in boiling
alcohol. Dissolyes in hydrochloric add, and is repredpitated by ammonia. Boiled
with excess of hydrochloric add, it is resoWed into sulptiide of eubon, sal-ammoniac,
and aldehyde. On adding oxalic add and then ether to the alcoholic sdntion of car-
bothiaidine, crystals of oxalate of ammonium are formed. The alcoholic solution
forms, with nitrate of silver, a greenish-black predpitate, whidi gradually changes into
sulphide of silyer; with mercwric chloride it forms a thick white curdy predpitate, and
witn comer-salU a green predpitate. (Redtenbacher and Liebig, Ann. Ch.
Pharm. Jxy. 43.)

OAXBOTBULXZVaa ^}m« — Ouanidine, a base obtained by the action of

oxidising agents on guanine, may be yiewed as a triple molecule of ammonia (N^H*),
in which 4 at H are replaced by the tetratomic radide carbon. Seyeral substitution
deriyatiyes of carbotriamine are also known, yiz. :

Carhomeihtfltriamine, N'.C.(U±i*)H*. — ^This constitution may be ascribed to me-
thyluramine, a base resulting fiN)m the action of oxidising agents on creatine.

CarbotriethyttriaTnine, N'.C(C*H*)*H*. — ^Produced by heating cyanurate of ethyl
with ethylate of sodium. (Hofmann, Proc Boy. Soc xL 282.)

Carhodvphenyltriamine, lPjS.(CR'yjS*, — ^This is the composition of melaniline.

CarbotriphmvUriamme. N'.S1(C^H*)'.H*.— This base is produced by the action of
tetrachloride of carbon on phenyhunine (p^ 766).

All these bases may likewise be regarded as diamines containing 1 at cyanogen in
plaaB of I at hydr(»en ; thus, carbotriamine « cyan-diunine -■ N'(C^).H'. (See
£thtl-, Hbthyl-, and Pkhntl-Diamuves and TniAifiirBs.)

OABBOVXVZO Ada. Syn. with Casboitatb of Etrtl and Htdboobw. (See
CABBomc Ethebs, p. 801).

CAEBOVINOMETHYLIDE - CAREX.

808

L Cabbovatb of Ethtl and Mbtril (p^ 801).
A gem highlj prized by the ancientSi probably the alnumdiD
or noble garnet.

Syn. with Aixofhanio Aozd. ■
lTB or. CH^S'O*. — Syn. with Ethionio Auxtobidb.

W AMABA* The dried h^b of this plant oontaina an azotised
and snlphuretted organic acid, either identical with or very similar to the myionic add
of black mustard seed, in combination with an oz]^anic (probably basic) compound.
Moreover this acid, either free or in combination with bases, derdops, under uie in-
fluence of myroeyn, but not under that of the emulsion of bitter aunonds, an acrid
■volatile oil, very much like oil of horse-radish or scurvy grass. The decided bitterness
and lower degree of pungency of the fresh herb appear to be due to the absence of
myrosyn or of some analogous compound capable of developing the pungent oil.
(Winckler, Jahrb. pr. Phum. xviiL 89.)

CMkXBAMOIB OXXn An essential oil extracted by distillfltidn from the seeds of
several kinds of cardamom, espedally Alpinia wrdamomum and Amomum repent. It is
pale, aromatic, and has a bumine taste. Spedilc mvity, 0*945. Soluble in ether,
alcohol, and oils, also in acetic acid and ciiustic potash. It detonates with iodine, and
is set on fire by strong nitric acid. . The oil amoimts to 4*9 per cent of the seed-kemeLi
of amomum repens.

Giystals deposited from old cardamom oil were Ibund by Dumas and Peligot
(Ann. Oh. Pnys. [2] hii. 884) to have the formula of a hydrate of camphene,
C"H".8HK).

Cardamom also contains a fixed non-drying oil, which has a rancid bitter taste, and
saponifies by boiling with potash.

04UUK»&. An oily liquid contained, together with aaaesvdic acid (p. 209), in the
pericarp of the cashew-nut {Anaoairdiwm or Caanmum oeetdmUaU), To obtain, it the
pericarp is exhausted with ether, the ether distilled ofi^ the residue washed with water
to remove tannin, then dissolved in 15 to 20 pts. of alcohol, and digested with recently
precipitated hydrate of lead, which takes up the anacardic add, while the oardol re-
mains in solution. The greater port of the alcohol is removed from the filtered liquid
by distillation, water added to the remaining liquid till it^beoomes turbid, and after-
wards acetate and subaoetate of lead till it is decolorised« " Lastly, the lead is predpi-
tated by sulphuric add.

Gardol is a yellow oily liquid, insoluble in water, very soluble in alcohol and ether;
Uie solutions are neutral to litmus. It is not volatile, but decomposes when heated.
It blisters the skin strongly. According to Stadeler, it contains 60 per cent, carbon
and 8*8 or 8*9 hydrogen, whence he dedoces the formula C^E^O^ ; it should perhuxi
beC«IPW.

Cardol predpitates basic, but not neutral acetate of lead. Strong sulphuric add
dissolves it witn red colour. Nitric add appears to form with it under certain cir-
cumstances, the same products as with anarardic add. Strong potash-le^ colours it
yellow, and ultimately dissolves it; and the solution, in contact with the air, acquires
a deep red colour, and then fiorms red or violet predpitates with most metallic salts.
(Stideler, Ann. Ch. Pharm. Ixiii 187.) .

OAXBX. The ashes of Carex remota and CI aofUa hava been examined by EL
Witting. (J. pr. Ghem. Ixix. 149.)
The firesh plants contained in 100 pts. :

Water. ^TSS? lib.

. 5275
. 69*60

2*81
4-90

Fe*0«
2-23
1*39

NaCl

10*23

7-28

Mn*0
1*45
2*02

K«0
28*52
87-94

P«0«
4*95
7-66

45*18
29-28

Ka*0

0*72

0*85

S0«
1*93
1*36

207
1-12

„ acuta
The ash contained :

C, remota .
C, acuta .

C. remota •
C. acuta •

The quantities of soluble and insoluble constittteDts of the ash were as follows : —

^'S;.'' ss?is/j >"o»»"-

49*15 29*45 21*40

57*56 81*50 10*85

8f 2

OaH)

7-86
7-90

C0«
4*75
4*86

MgK)
9-22
7-36

SiO*
30-33
16*98

804 CARICA— CARMINE,

CJkMXOJL PAVJLTA. Papaw Tree. — ^Eveiy part of the papaw tree, except the
ripe fruity aflfords a milky juioe, which is used in the Mamitias as an efifectoal remedy
for the tape-worm. In Europe, however, whither it has been sent in the concrete
state, it has not answered. The miUcy juice is said to make meat washed in it Tezy
tender, and the leaves and fruit are said to have the same effect upon the flesh of 6ld
hogs and poultry which are fed with them ; the flesh, however, soon becomes putrid.
The juice yields a substance resembling the flesh or fibre of animals. U.

CABZaS. See Bonb (p. 623).

I^ft^'— '■'"■ — - A sub-species of augite. Colour black. Occurs massive and disse-
minated. Internally splendent. Besino-vitreous. Distinct cleavage of 124^84'. Fracture
conchoidaL Greenish-black variety : translucent on the edges, velvet-black, opaque.
Occurs on the Saualp in Carinthia, in a bed of primitive rock, associated with quarts,
kyanite, garnet^ and coisite. (Jameeon^s Mineralogy.) V.

Dana (ii. 172) enumerates it as a variety of hornblende.

CAaMZBZVa. An organic base produced bj passing lutidine over red-hot lime.
Its composition has not been ascertained. It produces a fine red colour with pine-
wood and hydrochloric acid, and pale green with bleaching powder ; hence it is pro-
bably a mixture of pyrrhol and vertidine. (Gr. Williams, Chem. Soc. Qu. J.
vii. 97.)

OAXMZWAVSTBA. C'*H*0' (?) — A red colouring matter obtained by heating
naphthalene with a solution of acid chromate of potassium, and adding sulphuric or
hydrochloric acid. It is dissolved by alkalis and precipitated in its onginai state by
acids. (Laurent, Bev. scient ziv. 560.)

OJkMMtMVtMm A product which Laurent obtained by the action of ammonia on
dibromisatin. (See I&itih.)

OAMMXMM, CJkXMZWZC ACID. (Pelletier and Caventon, Ann. Ch.
Fhys. [2] viii. 250, \l 194 ; Warren de la Bue, Ann. Ch. Pharm. Iziv. 1, 23 ; Gerh.
iii. 760.)-— The colouring matter of cochineal (Coccus cacti). To separate it, cochineal
is exhausted with boiling water ; the extract is precipitated by subacetate of lead
slightlv acidulated, care bein^ taken not to add the lead-solution in excess ; the
precipitate is washed with distilled water till the wash-water no longer gives a preci-
pitate with a solution of mercuric chloride, then decomposed by sulphuretted hydrogen ;
the filtrate is evaporated to a syrupy consistence and dried over the water-bath ; and
the dark purple product thus obtained is treated with alcohol, which extracts the carr
minic acid.

This acid forms a purple mass, fdsible and soluble in all proportions in water and in
aloohoL Sulphuric and hydrochloric add dissolve it without alteration. It bears a
heat of 136^ C. without decomposition. It is veiv hygroscopic. Its solution forms red
precipitates with the alkaline earths, also with the acetates of lead, zinc, copper, and
silver.

According to De la Bne's analysis, carminie acid contains 54*1 per cent, carbon and
4*6 hydrogen, agreeing nearly with the formula C'*H**0*.

Sehiitzenberger (Ann. Ch. Fhys. [3] liv. 62^ regards De la Bue*s carminie acid
as a mixture, and assigns to pure carminie add tne formula C'H'O* ; he states also
that it is mixed in cochineal with an oxycarminic add, CH*0', and perhaps also with
other adds of intermediate composition. These statements do not appear, however,
to be borne out b^ the results of his analyses.

Carminie acid is decomposed by chlorine and bromine. The bromine-compound is
yellow and soluble in alcohoL^

Carminie acid treated with nitric add yields fdtrocoeeutie acid ; a compound which
is isomeric with trinitranisic add, and ciystallises in yellow* rhomboidal tables, soluble
in cold but more soluble in hot water ; soluble also in alcohol and ether. All its salts
are soluble in water.

The mother-liquor of the preparation of carminie add contains a crystalline sub-
stance, insoluble in alcohol and ether, soluble in ammonia, and identical with tyrosine,
(Warren de la Bue.)

The colouring pri^idple of cochineal (carmine) was previously obiained in an impure
state by Pelletier and Caventou (Ann. Ch. Phys. viii 2501 by treating the cochineal
with ether to extract the f&Uy matter, and digesting the residue in alcohol.

The fine red pigment known in commerce as carmine, is prepared by treating a
solution of cochineal with cream of tartar, alum, or acid oxalate of potasdum. The
fatty and albuminous matters then coagulate and cany down the colouring matter
with them.

By treating a solution of coduneal with an alkaline carbonate and alum, a compound
of the colouring matter with alumina is obtained, known by the name of carmine-iaJte.

CARMINITE— CAROTIN. 805

For this purpose^ the ooaner sediment deposited from a decoction of ooehineal, after
the finer particles have been separated by decantation, is generally used. For cheaper
florts, extract of Brazil wood is sometimes mixed with the cochineal.

Cochineal colours are nsed for dying wool and silk crimson or scarlet; but the
colonrs it produces are remarkable more for brilliancy than for durability, and are easily
stained by water or alkalis. The mordants used are alum, cream of tartar, and tin-
salt (See XJrii Dictionary of Arts, Manufactures and Mines, L 616.)

OJkMMlM IT JIv or Carmine-mar, — A mineral, probably consisting of anhydrous
arsenate of lead and iron, from Momhausen in Saxony, where it occurs, with Beudan-
tite, in quarts and brown iron ore. It occurs in clusters of fine needles, and in sphe-
roidal forms with columnar structure, cleaving parallel to the fiices of a rhombic pnsm.
Hardness » 2*6. Lustre vitreous, but pearly on the cleavage faces. Colour carmine
to brick-red ; powder reddish-vellow. Translucent Brittle. Before the blowpipe it
gives the reactions of arsenic, lead, and iron. (Dana^ ii 410.)

OJkMMVTMLXMi AOZD. An acid obtained by Muspratt and Danson (Phil.
Mag. [4] ii. 293 V by the action of nitric acid on the aqueous extract of cloves. It
separates from toe concentrated solution in yellow micaceous scales ; and by precipi-
tation with acetate of lead, decomposition of the lead-precipitate with sulphurette<l
hvdrogen, and evaporation, it may be obtained in white ciystals. It is insoluble in
alcohol, ether, ana cold water, soluble in hot water, ammonia, and potash. When
heated, it yields a yellow oil and emits an odour of burnt sugar. Strong sulphuric
.acid does not act upon it in the cold, but carbonises it when heated. A moderately
concentrated solution of the addprecipitates the salts of the alkaline earths, forming
a very thick gelatinous mass. With copper-salts it forms a green, with silver and
ferrous salts a white, and with ferric salts a yellow precipitate, all of flooculent cha-
racter.— ^Muspratt and Danson assign to the barium and lead-salts of this acid, the
doubtfbl formula, C^B^MO^.

O <l W. W A TiTiTTM. KCL2MgCL6H'0. — ^A salt which sometimes separates in coarse-
grained masses, often coloured by oxide of iron, from the mother-Uqnor of rock-salt,
also of certain brine-springs ; it may also be obtained by carefol evaporation of the
mother-liquor of sea-water. (Jahresber. d. Chem. 1866, p. 884; 1868, p. 739.)

OABWAVBA VAX* A wax which coats the leaves of the Cor^/pha cerifera, a
palm growing in Brazil, and is obtained by drying the leaves and meltmg the coating,
which sepanUes in scales. It forms hard, brittle lumps of yellowish-white colour, in-
clining to green, and has an odour of melilot, but no taste. It melts at 97° C, or accord-
ing to Lewy (Ann. Ch. Phys. [31 xiii. 438) at 83'6o. According to Brands (PhiL
Trans. 1811, ^. 261), it is insoluble in cold, sjparingly soluble in hot alcohol, forming a
greenish solution. Similarly with ether. With fixed oils it mixes in all proportions.
With caustic potash it forms a pale rose-coloured mass without actually saponifying.
Nitric add converts the wax into a yellow friable mass. Chlorine bleadies it In
other respects it behaves like beeswax. According to Lewy, it contains 80*3 per cent
carbon and 13*0 hydrogen. (Handw. d. Chem. 2** Aufl. ii. [2] 807.)

OJMUTAT. A variety of lithomaige from Bochlitz. (Breithaupt)

OAXnXiIAJr. A subspedes of chalcedony, of white, yellow, brown, and red
colour. It has a conchoidal fracture. Specific gravity 2*6. Semitransparent, with
glistening lustre. The finest spedmens come from Cambay and Sunt in India* It is
found in peculiar strata, thirty feet below the surface, in nodules of a blackish-olive
colour, passing into grey. These, after two years' exposure to the sun, are boiled for
two davs, and thereby acquire the lively colours for wnich they are prised in jewellery.
Camelian is softer than common chalcedony. It consists mainly of tilica (about 94

S)r cent) with alumina, and a small quantity of ses^uioxide of iron. According to
authier de Claubry, the colour prooeeos, not from oxide of iron, but from an organic
substance. This, however, is denied by He in ta. (Pogg. Ann. Ix. 619.)

O A »0^ tk VMIM* A mineral containing organic matter, found in a coal-mine in
Upper Silesia. It has the aspect of honey-stone ; colour, honev-yellow to wine-yellow :
translucent on the edges ; has a faint unctuous lustre ; very brittle. Specific gravity
1*616. Hardness 2*6. It is decomposed by hydrochloric add. It contains about 16*10
per cent water, 47*26 alumina, 29*62 silica, and 1*83 carbon. The water is not com-
pletely given off below 290^ C.', at which temperature the organic matter begins to de-
compose. The organic matter appears to be allied to humic add. (Sonnenshein,
J. pr. Chem. be 268.)

OAXOTZV. C'E^'O. — ^The colouring matter of the carrot (Daueus Caroia), It
was fint isolated by Wackenroder in 1831 (Geiger's Hag. xxxiii. 144), afterwards
examined by Zeiss (J. pr. Chem. xL 297), and recently with greater exactness b^
Hnsemann (Ann. Ch. Pharm. cxvii. 200).

3f 3

806 CAROTIN— CARPHOLITE.

OurrotB also contain a cdLonrleos substance, hydrocarotin, C'SP'O, containing
6 at. H more than carotin ; and as they are colourless in the early stages of their
growth, Husemann considers it probable that they at first contain only hydrocaxotiny
which gradually changes to red carotin by oxidation.

Preparation, — ^The esEpressed juice of bruised carrots is precipitated with sdohuric
add, to which a small quantity of tincture of galls is added ; the balf-dried coagulum is
repeatedly boiled with five or six times its volume of 80 per cent, alcohol, which extracts
the hydrocarotin ; the residue^ sfter dxyins at a gentle heat^ is exhansted with sulphide
of carbon ; and the filtrate is mixed with an equal Tolume of absolute alcohol The
solution, when left to itself, deposits the carotin in crystals of the dimetric system, which,
while in the liquid, exhibit a golden-green lustre hf reflected light ; i^ however, the
sulphide of carbon was mixed with much alcohol, or if the solution was too much con-
centrated, the crystals are microBcc^ic, and of a ruby-colour. The crystals are washed
on a water-bath funnel with boiling 80 per cent^ alcohol, afterwards with absolute . al-
cohol, till the wash-liquid exhibits only a fiunt yellow colour, and when eraporated on
a watch-glass, leares small octahedral ctrstals.

The pure carotin whidi remains, exhibits, after drying in the air at mean tempera*
ture^ a red-brown colour with yelvet lustre, becoming bzi^t red when dried at lOO^C.
It smells like Florentine Tiolet-root, especially when heated. It is rather heavier than
water; dissolyes sparingly in alcohol, ether, and chloroform, easily in sulphide of car-
bon, benzene, and volatile oils ; fixed oils dissolve it slowlv, with red colour. It be-
comes soft at 126° 0., and melts at 168° to a thick dark rea liquid.

Carotin forms at low temperatures a colourless crystalline hydrate, which may be
obtained by placing a concentrated solution of carotm in sulphide of carbon (not anhy-
drous) in a watch-glass, overa freezing mixture produduff a temperature of — 10° C. It
then separates as a while efHorescence made up of smafl needles ; but as soon as it is
taken out of the freezing mixture, it gives up its water, and is converted into red carotin.
The same phenomenon is exhibited by a solution of carotin in benzene, excepting that
the hvdrate is then slightly yellow. Another hydrate is sometimes formed by adding
to a dilute solution of carotin in sulphide of carbon, so much absolute alcohol, that the
turbidity at first produced shall disappear, at least on heating the liquid. It separates
in thin, iridescent, six-sided laminae, and Appeaxa to be more stable than the first-men*
tioned hydrate. The composition of these hydrates has not been determined.

Carotin is very unstable ; during the evaporation of its solution, it often separates in
a light yellow amorphous modification, which is but sparingly soluble in solphide of
carbon. The red crystals gradually become colourless from without inwards, when
exposed to daylight, and more quicklv in sunshine ; the new substance thus formed is
inodorous, dissolves readily in alcohol or ether, but with difileulty in sulphide of carbon
or benzene, and separates from these solutions in the amorphous state. The same
change takes place when carotin is exposed for a long time to a heat of 160° C.
Whether the new substance thus formed has the same composition as carotin, is not
yet made out. Carotin heated to 260° C. forms a mobile liqud, which on cooling soli-
difies to a soft yellowish-red mass. At higher temperatures, it carbonises and gives off
empyreumatic vapours.

Fuming nitric acid dissolves carotin with yellow colour, and water separates from
the solution a yellow nitro-compound. Strong sulphuric acid dissolves carotin with
purple colour ; and on carefully adding water, the colour disappears, and a somewhat
modified carotin separates in dark green flocks, which, like carotin altered by light, are
coloured brown by sulphuric acid. — Sulphurous anhydride changes the colour of carotin
to dark indigo, but does not alter it fiiilher ; the blue substance crystaUises from ben-
zene in red cubes, and is also converted into red carotin by boiling with potash.

Dry chlorine gas converts carotin into tetrachloro-carotin, a white substance
soluble in ether and in sulphide of carbon, becoming soft and dark-red at 100° C,
melting at 120°. Another substitution-product containing less chlorine appears also
to be formed.

Bromine and iodine likewise decompose carotin, forming substitution-products which
are more Aisible than carotin itself.

Carotin is not decomposed by dilute acids, by hydrochloric add pas, sulphuretted
hydrogen, sulphide of ammonium, or by alkaUs, either in aqueous or in alcoholic solu-
tions. Solutions of carotin are not predpitated by metallic salts ; the alcoholic solution
is coloured greenish by ferric chlonde.

A substance having tiie same colour and composition as carotin, is obtained by treat-
ing tribromhydrocarotin, C"H''Br'0, with potash; but the identity of the two has not
yet been completely established. (See Htdbocabotin.)

CAXVBO&tTB. A silicate of manganese^ aluminium, and iron, found near
Schlackenwald in Bohemia, in radiated and stellated tufts, sometimes also in rhombic
prisms of 111^ 27', and 68° 33', with the lateral edges truncated. Spedfic gravity -*

CARPHOSEDERITE— CARROT.

807

87-53

28-47

18-88

6-27

S«*15

28-67

1916

2-54

8616

19-74

20-76

9-87

2-935. Hudnaw » 5 to 5*5. It is opaooe, with strnw-yellow or wu-jrellow colour
(hence th^ xuune^ from icop^s, straw), and Titreons lustre. Its analysis gires —

SiO« A1*0» Mn^O« FoW Ca«0 HK) F.

— 11-86 — - 99-961 (Steinmann).

0^7 10-78 1*40 - 98-97 (Stiomeyer).

2-56 11-35 — -100-48 (Haner).

Hence the formula 2R*0'.3SiO' + 3 aq.. th^ sesqoioxides of alnminiwTn, manganese^ and
iron being supposed to replace each other isomoxphonsly.

By reducing thesesqmoxides to protoxides (substituting r ^ {B), the fozmula be-
comes that of an orthosilieate, 2r*O.SiO' -i- aq. » r^SiO^ + aq. According to Kobeil,
the manganese and iron are in the state of protoxides, and the formula is (M nK).A1^0')
+ 2(H'O.SiO*). (BammeUberg'8 Mineralchemie, p. 587.)

CJkMVMO&XDMMXTM, A h^drated phosphate of iron, containing small quantities
of manganese and sine, occuning in renifoim masses and incrustations of straw-yellow
colour and resinous lustre. Spedfie pravity 2*5 ; hardness 4 to 4*5. It is Ibund in
fissures in mica slate, and was first distinguisned by Braithaupt, among some specimens
from Labrador. (Dana, iL 481.)

OJkXWMOmTtEJUTWL A straw-yellow yariety of Thomsonite, from Bemfiord,
Iceland.

A commercial name of the TolatOe oil obtained from pi-
mento, the fruit of Myrtua pimento. It is yellowish, heayier than water, and smdls
like doves.

OASmo&ITB. (W. L. Faber, Sill. Am. J. (2) ziii 418 ; Smith and Brush,
ibid, xvi. 866 ; Genth, abid, xxiii. 115.) — ^A sulphide of cobalt and copper, from Finks-
burg^ Carrol County, Maryland, U. S. Forms homogeneous, Teiy friable masses,
with indistinct deavage; tin-white to sted-grey colour; metallic lustre; iron-blade
streak; uneven fracture, iqpproaching to the conchoidaL Hardness 6-6, Specific
gravity 4*58. The mineral has not be«i fi>und in distinct crystals, but appears to belong
to the regular system.

Quarts

2-18 - 99-80 (Faber).

- a 100*08 (Smith and Brush).

0-97 " 100-19 (Genth).

Faber deduces from his analysis (after deducting the nickd, arsenic^ and iron, toge-
ther with 8-468 per cent, sulphur required to form oopper-nickd and magnetic pyrites),
the formula Co^Cn^S or CoConS. Smith and Brush regard the mineral as cobalt
pyrites (Co^), in which part of the cobalt is replaced by copper.

OAMMMkMMMMM MOM. See CABiLORHur Moss (p. 747).

OAXKOT. Baueua Oarota, — The ashes of the root, leaves, and seed of the carrot
have been analysed by Way and O^ston (Jahresber. d. Chem. 1849, Table £ to page
656, and 1850, Table B to p. 660) with the following percentage results :

27.04

1*82

82*99

28-50

1*50

5*81

41-29

18-15

87-70

1-54

1-26

41-71

17*55

88-70

1-70

0-46

WbttoBdctan

Long red Surrar
(oo poor landy loil)

PoCMh

Boot.

LeavM.

Sead.

SI '40.41 •97

6-ft5.7*6S

48-78

IMO

16-91

Soda

8*1S-I7'ft8

9-46.19-76

19-11

4*85

1-98

Line

6-0a-IIB9

99-50-44*96

0-64

9404

89-96

MagHMla .......

S'Sfr. 5*89

9 50—9*93

9*99

0-80

5-70

Fenicozida

on— 1-66

0*90- 4-06

0-51

8-48

0-84

Sulpharic anhjdrlda

4*tt— 9-49

6-47— »68

4-96

o-os

4-90

Silicic »

0^76-.l-99

l-f»~ 7 89

11-61

4-50

Carbonic „

1»*1»— 19-11

14-9a-.99-8S

18 00

9815

15-18

Pboiphorie ,.

GhlorldaofMolam . . . . •

rsS- 9-17

1-19— 9-66

19-81

6-91

18-88

4-91« 7-65

8'77-15-ll

traca

8-69

5-94

99-96

99*96

99-99

Afh per csDl of dry mtetaDM

S*19*9*80

l»'8O-il-80

8-44

lOHtt

4-80

•I frcah „ • .
Moittore lb 100 pM. of alr^riad f nbttanoo

0*n— 106

9-86— fr89

0-47

8*78

8-80

86-40

80 00

1800

Sulpbur per eonC. In dry tiibttaDoo .

0-88

8-06

CJLBmOTf ODb or. The root of the carrot contains a very small quantity (0-01 14^
per eentw of a volatile oil, of specific gravity 0*8863 at 12^ C, which may be obtained

8f 4

SOB CARTHAMINE— CARVENE.

by distilling the fresh roots with water. It has a very strong pungent taste and smell,
dissolyes sparingly in water, freely in alcohol and in ether. (Wackenroder, Mag.
Fhazm. Txriii. 145.)

OAMTHJkMXMm The eolonring principle of saifiower ( Carthamtu Hnetoritu\ flrat
examined by Cheyrenl, afterwaras more fully by Schlieper (Ann. Ch. Pnarm.
Iviii. 362.)

The flowers of Carthamtu tinetorius contain two colonred principles, one yellow,
soluble in water, and of no use in dyeing, the other red, soluble in alkalis and preci-
pitable by acids from its alkaline solutions: this is cartkamin. To prepare it> safflower
IS first washed repeatedly with water, to free it from the yellow substance, then treated
with solution of carbonate of sodium ; the liquid is saturated with acetic acid ; and
pieces of cotton are immersed in it.» on which the carthamin is deposited. After
twenty-four hours, the cotton is removed and treated with solution of carbonate of
sodium, which redissoWes the colouring matter; the solution is mixed with citric add,
whereby the carthamin is precipitated in red flocks ; and, lastly, these flocks are dis-
solved in alcohoL The solution evaporated in vacuo yields the carthamin in the form
of a powder, having a deep red eolour with greenish iridescence. It is sparingly soluble
in water, insoluble in ether, but easily soluble in alcohol, yielding a &e purple
solution.

According to Schlieper, carthamin contains 56*9 per cent, carbon and 5'6 hydrogen,
agreeing with the formula C'^H'K).

The yellow coburing matter of carthamus is add. It has a bitter taste and great
colouring power. It combines readily with oxygen, and is converted into a brown
substance. It unites with oxide of lead, forming the compound (Pb*0)'.CH'*0*.

The red colouring matter 'of carthamus is used in dyeing, and for the preparation of
rouge. The flowers, after being freed as much as possible from the yellow dye by
repeated washing with water, are pressed and dried, and sent into the market in the
form of cakes, known in commerce as safflower^ Spanish red, or Cktna cake.

For the preparation of rouge, the red colour ib extracted by a solution of carbonate
of sodium, and precipitated by sulphuric add or by lemon juice previously depurated by
standing. This predpitate is dried on earthen plates, mixed with tale or F^ch chalk,
reduced to a powder by means of the leaves of shave-grass triturated with it till they
are both very fine, and then sifted. The fineness of the powder and proportion of the
predpitate constitute the difference between the finer ana cheaper rouge. It is like-
wise spr^tid y&cj thin on saucers, and sold in this state for dyeing.

Carthamus is used for dyeing silk or cotton of a poppy, cherry, rose, or bright
orange-red. The cakes of safflower having been disintegrated by steeping in water,
the red fibre is washed in sieves as long as the water which runs through acquires a
yellow colour. It is then put into a deal trough, and sprinkled at different times with
pearl ashes, or rather soda, well powdered and sifted, in the proportion of 6 lbs. to 100,
mixing the alkali well as it is put in. The alkali riionld be saturated with carbonic
add. The carthamus is then put on a doth in a trough with a grated bottom, placed
on a larger trough, and cold water poured on till the larger trough is filled ; and Ibis
treatment is repeated, with addition of a little more alkali toward the end, till the car-
thamus is exhausted and become yellow. Lemon juice or sulphuric add is then poured
into the bath, till it is turned of a fine cherry colour, and after it is well stirred, the
silk is immersed in it. The silk is wrung, drained, and passed through fresh baths,
washing and drying after evexj operation, till it is of a proper colour ; after which it is
brightened in hot water and lemon juice. For a poppy or fire colour, a slight annotto
ground is first given ; but ttie silk should not be afumed. For a pale carnation, a little
soap should be put into the bath. All these baths must be usea as soon as tiiey are
maae, and cold, because heat destroys the colour of the red fecola. The colours pro-
duced by carthamus are very beautiful, but fugitive. (See Ur^9 Dictionary of Arts,
Manufactures and Mines, i. 624.)

CUkSTI&AliB. The cartilages consist of a dry fiexible tissue, which contains
but a small quantity of inorganic matter, and when boiled with water yields chon-
drin (^. v.), a substance resembling gelatin, but differing in certain reactions.

According to Scherer, the cartilage of the ribs contains 40*5 to 50*9 per cent carbon,
7*0 to 7*1 hydrogen, 14*9 nitrogen, and 27*2 to 28*5 oxygen. (See Bonb.)

OAHVXn, CAAVO&, and CA»VJLCBOZto (Volckel, Ann. Ch. Fharm.
XXXV. 308 ; Ixxxv. 246; Schweizer, ibid. L 329; Gm. xiv. 283, 414.)— Essence of
caraway consists of two essential oils, carvene, C"H^* and carvol, C'H'H), which may
be separated by fractional distillation. The latter, however, is more easily prepared
by agitating oil of caraway with an alcoholic solution of sulphide of ammonium :
svlphydrate ofearvol, (CH**0)^H*S is then formed, and Uiis compound, decomposed
\>j ammonia yields canroL (Varrentrapp, Handw. d. Chem. 2** Anfl. ii. [2] 812.)

CARYOPHYLLIC ACID— CASE-HARDENING. 809

Carvene is a colourless mobile oil, lighter than water, haTing a slight agreeable
odour and aromatic taste. Soils at 78^ G. It is nearly insoluble in water; yeiy
soluble in alcohol and ether; it absorbs hydrochloric acid, and forms a ayBtalline com-
pound, which melts at 50-6 C. and consists of 0>«H>^2H0L

Cartro/ is a liquid boiling at 250^0. Specific graTity 0*953. Itisresinisedbystrong
nitric or sulphuric acid, and forms with hydroch&ric acid an oily compound containing
C'«H»<O.HCl StUph^drate ofcarvol, 2C"H"0.H«S, crystallises from solution in alooh<3
in long needles haying the lustre of satin ; they are fiisible, and when cautiously
heated, sublime almost unaltered (Yarrentrapp). Sulphydraie of ndphocarvoi,
20*f£D*S.H'S, is produced by passing sulphuretted hydrogen for a long time through
alcohol in which the preceding compound is suspended. It then separates as a thick
oil, which dissolyes in ether, and is deposited therefrom in white flocks. The ethere&l
solution precipitates chloride of mercuiy and dichloride of platinum ; but the precipi-
tates haye not a constant composition. (Yarrentrapp.)

Carvaerol, a substance isomeric with caryol, is obtained by treating oil of caraway
with potash, or again by treating the same oil with iodine, cohobating seyeral times,
and washing the product with potash ; as thus obtained, howeyer, it is mixed with
caryene. CaryacTol is also found among the products of the action of iodine on
camphor (p. 729), 0»«H'«0 + 21 - 2HI + C"H»*0. Caryacrol when pure is a colour-
less yisdd oil lighter than water, and soluble in water to a small amount. It has an
unpleasant odour, and an acrid yery persistent taste. Boils at 232^ C, giying off
yapours which irritate the organs of respiration. It bums with a bright yezy smoky
flame.

BkCTZB. Syn. with Euobnic Acm.

C*'H"0. — This substance, isomeric with oommon camphor,
is contained in considerable quantity in cloves, the dried flower^buds of the doye-tree,
CaryophyUus aromoHcug, which is mdigenous in New Ghiinea and the Moluccas^ and
cultiyated in Sumatra, in the isles of Mauritius and Bourbon, and in BradL It may be
extracted by treating doyes with cold alcohol ; the liquid in about flfteen days be-
comes coyered with crystals, which may be purified with solution of soda. The doyes
may also be exhausted with ether, and the caryophyllin separated by agitaUnj^r the
ethereal solution with water. Crude oil of doyes also deposits cazyophyllu on
standing.

Caryophyllin forms silky colourless needles arranged in radiating ^ups, destitute
of taste and smell. It melts with difficulty and with partial decomposition (D u m as^ ;
sublimes at about 285° C. (Muspratt). It dissolyes sparingly in cold alcohol, easily
in boiling alcohol and in ether; also in hot caustic alkalis. Stronff sulphuric add dis-
solyes it m the cold without blackening, but the liquid blackens ymea heated. Nitric
add oonyerts it into a resinous substance. (Gerh. iy. 278.)

tUkBOAXMOm The alluyial soil, consisting of ferruginous sand and day, in which
Brazil diamonds are found.

OABCABXJb&A ™^^-*- The bark of cascarilla, Oroton eleutheria and Or,
easeariUOf shrubs indigenous in the West Indies. It contains albumin, tannin, a red
colouring matter, a f&tty substance, an essential oil haying an agreeable odour, wax,
resin, a gummy substance, starch, pectic add, wood, fibre, and cascarillin, together
with a caldnm-salt and chloride of potassium. It possesses tonic and aromatic pro-
perties.

OASOAXZ&KAf OZ& OF. Cascarilla bark contains a yolatOe aromatic oil,

amounting to 0*37 per cent (Bley), 0'87 (Trommsdorf). It is dark yellow, some-
times with a bluish tinge ; of specific grayitr 0'909— 0 938 ; boils at ISO^* C. or higher
(Trommsdorf). According to Ydlckd, the first distillate is colourless^ of sp^ific
grayity 0862, and boils at 173^ C (Gm. ziy. 363.)

C <l BO A BTTiIiTW is obtained by treating the aqueous extract of C4M4^rilla bark
with acetate of lead, filtering, and predpitating the excess of lead with sulphuretted hy-
drogen. The liquid eyaporated at a gentle heat depodts an amorphous mass, from which,
after washing with cold alcohol, the cascarillin may be extracted by boiling alcohol.
It is purified b^ recrystallising seyeral times, after deoolorisins; with animal charcoal.
It crystallises in needles or in hexagonal plates, which are colourless, bitter, fridble,
decomposible by heat^ sparingly soluble in water, more soluble in alcohol, ether, hydro-
chloric add, and sulphuric acid. The aqueous solution is not predpitated hy alkalis,
tannin, acetate, or subacetate of lead. (Duyal, J. Fharm. [3] yiii. 91.)

CI il S»-^W il BT>Myiy Ck Sted when hardened is brittle^ and iron alone is not
capable of recoiying the hardness which sted may be brought to possess. There is, neyer-
thdess, a yariety of artides in which it is desirable to obtain ful the hardness of steel

810 CA.SEIN.

togeHier with the ton^esB of iron. Theae veqidflites aie united by the art of ease-
hardening, which does not differ from the making of steel, except in the shorter dnra-
tion of the process. Tools, ntensila, or ornaments intended to be poUshed, are first
mannfactnred in iron and neariy finished, then pot into an iron box, together with
Tegetable or animal charcoal in powder, and cemented for a certain time. This
treatment eonyerts the external part into a coating of steel, which is usually veiT thin,
because tiie time allowed for the cementation is much shorter than when the whole is
intended to be made into stc^ Immersion of the heated pieces in water hardens
the surface^ which is afterwards polished by the usual methods. Hoxon {Mechanie
ExeroiseSf p. 56) gives the following receipt : — Cow's horn or hoof is to be baked or
thoroughly dried, and pulTorised. To this add an equal quantity of bay salt: mix
them with stale chamber ley, or white wine vinegar : coyer the iron with this mixture,
and bed it in the same in loam, or enclose it in an iron box : lay it then on the hearth
of the forge to dry and harden : then put it into the fire, and blow till the lump hare
a blood-r^ heat, and no higher, lest the mixture be burnt too much. Take the iron
out, aud immerse it in water to harden.

The same end is now more effectually attained by heating the tool red-hot^ and
sprinkling over it ferrocyanide of potassium (yellow prussiate) in fine powder, then
quenching it in water. Some prefer smearing the surface of the bright iron with loam
made into a thin paste, with solution of the yellow prussiate, drying it slowly, then
heating it nearly to whiteness, and plunging it into cold water, when the heat has
fallen to dull redness. (See Ur^s DicHonarjf of Arts, Manufactures and MtneB, i.
630.) V.

CAMMXM constitutes the chief part of the nitrogenised matter oontained in the milk
of mammiferous animals. It takes its name from caseus, the Latin name of cheese, which
is principally composed of casein mixed with fiatty matters (butter) and decomposition
products of casein (carbonate of ammonium and ammoniacal salts of acetic^ butyric,
Valerie acids, &c.).

Preparaiion, — According to the views of Berzelius, Braoonnot, and others^ two modi-
fications of casein are supposed to exist, the one soluble in water, the other coagulated
and insoluble in water. Soluble casein has, however, never been prepared fn& from.
alkali, and is most probab^ idoitical with albuminate of potassium or sodium
(Lehmann). Insoluble casein has nearly the same properties and composition as in-
soluble albumin.

Soluble casein may be prepared as follows : Fresh milk, from which the cream has
been removed, is evaporated at a eentle heat, a portion of the casein becoming coagu-
lated, while the rest remains dissolved. The residue is exhausted with ether, in order
to extract fiBrtty substances, and treated with water, which dissolves casein and lactin
(sugar of milk) ; a little tdcohol is next added to the aoueous solution, whereby most
of uie lactin is precipitated, the precipitate is washed wim weak alcohol, and a solution
of casein is obtained which always contains lactin and alkali (Gerh. iv. 4d4.)

Insoluble casein may be obtained by simply heating creamed milk near to tiie boiling
point, coagulating the liquid with a few drops of acetic acid, completely exhausting
the coagulum with water, treating with alcohol and ether, drying and powdering the
residue, and repeatedly <^gestin£ it with ether (Dumas and C ah ours). Perhaps the
best method is that ot Bopp (Ann. Ch. Pharm. Ixix. 16). Milk is coagulated with
hydrochloric acid, the coagulum washed, first with distillea water, and then with water
containing 2 or 3 per cent, hydrochloric acid, and finally with cold distilled water. A
jelly is thus obtained, dissolving at 40^ C. in a large quanti^ of wat«r. This aolution
is filtered and carbonate of ammonium cautiously added, and the precipitate is well
washed and exhausted with ether-alcohol. Whatever acid be employed in the co-
agulation, the casein, when treated in the maimer described, never contains any trace
of acid, and has always the same composition. (Gerh. loe. cit.)

Chemical Properties. — Soluble casein, when prepared in the manner described,
leaves, alter evaporation, an amorphous residue, inodorous, but having a sickly taste.
It does not rediasolve completely m water, nor does the solntion coagmate by heat» but
merelv becomes covered with a film, which forms again as often as it is removed.
Soluble casein is coa^^ulated by alcohol, a portion at the same time entering into solu-
tion ; a larger quantity is dissolved by boiling alcohol The coagulum produced by ab-
solute alcohol is completely insoluble io water. Solution of casein is precipitated by
all adds ([except carbonic acid) ; the precipitates redissolve in an access of add, and
the solutions become covered with a &m. when, evaporated in an open vessel Hineral
acids precipitate casein from its acetic acid solution. After the coagula thus obtained
have been well washed with water, they still redden litmus, although they do not
impart an acid reaction to water, even on boiling. The spontaneous coagulation of
milk is due to the formation of lactic acid (produced by the fermentation oflactin) the

CASEIN.

811

ftdid neutraliang the alkali in whieh ihe caaexn was disaolved, and thus rendering the
casein insoluble.

Soluble etuein always contains a large amount of mineral matter (when coagulated
by alcohol, 8 to 10 per cent.). Ossein coagulated by an add yields from 1 to 6 per
cent, ash, and the ash is nerer alkaline (Scherer). Casein contains phosphate of
caldum as a oonstitaent part Mulder (Aich. 1 1828, n. 165) found in casein 6 ^
cent phosphate of calcium, whidi is precipitated on coagulating any caseous liquid with
an aem, atthough enough free add be adoed to diasolTS any unoombined phosphate of

oddum.

When moist casein is ez^sed to the air, it soon begins to putnfy, yielding sulphide
and carbonate of ammomum, a neutral oily body, havinff a disagreeable smell,
together with bnfyrie and Taleric adds; at the same time the undeccmiposed casein
dissolves in the ammonia formed (Iljenko, Ann. Gh. Fhann. bdii. 264). According
to Bopp, a crystalline body possessing a most yowaial odour, is fonned under the
same circumstances. When casein putrefies out or contact with the air, it yields acetic^
butyric, yaleric^ and capric adds, as well as ammonia.

The Allowing are the results of the analysis of ooagulated casein, deducting ash :

Scherer.

Carbon

Hydrogen

Nitrogen

Sulphur

Oxygen

By akobol.

63-7
72

15*6

Bj the turn! Df Bj acetic

of milk. acid.

540 53-8

7-2 7-4

15-7 15-7

Bnehleder. Watther. Vcrdell.
By talvharlc

71 — —

1-0

0*9

Dumas and Caboari.*

'rom
«>»*snilk.
by acetic
acid.

53-5

7-1

15-8

Ffoia

msoat'ft
mUk,

by acetic
acid.

53*6

7-1

15-8

From
mtUc,
by acetic
acid.

53-7

16*0

From sheop*!

milk,

by acetic

add.

53*5

15*8

From human From blood
rollk, by weak boil-
by alcohol, inf alcobol t

53-5

7*1

15*8

53*8

7*1

15*9

Carbon

Hydrogen

Nitrogen

Sulphur

Oxygen

(Gerh. iv. 487.)

These numbers agree very dosely with those obtained by the same diemists in the
analysis of albumin, except that casein appears to contain less sulphur than albumin
^2*16, Yerdeil). Casein does not appear to contain any phosphorus, except in the
form of phosphate of caldum.

Coagulatea casein is readily soluble in caustic potash ; after boiling, the solution
contains sulphide of potasdum. When casein is fiised wiUi caustic potash, ammonia
is first evolved, then nydrogen ; the mass, at first dark brown, gradually dears and
becomes ydlow; it is then completdy soluble in water, and contains tyrosin, leudn,
valerate (sometimes butyrate), and oxalate of potasdum, as well as the potasdum-salt
of a volatile add having an excrementitious odour (Liebig). If a yeiy weak solution
of alkali is saturated with casein, the alkaline reaction completely disappears; the so-
lution thus obtained is predpitated by all' adds except carbonic. Casern dissolves in
a solution of phosphate of sodium, and neutralises it at the same time. It also dis-
solves largely in solutions of the alkaline carbonates, of common salt, chloride of am-
monium, nitrate of potassium, &c These solutions do not coagulate by heat, but
become gradually covered with a film which is insoluble in dilute alkalis and adds.
The same film is formed when milk is heated.

The solutions of casein are predpitated by all earthy and metallio salts. The pre-
cipitates with chloride, sulphate, and acetate of caldum and sulphate of magnesium,
are thrown down only on heating the liquid. Compounds insoluble in water and
hardening on exposure to the air, are obtained by heating casein with carbonate of
caldum or of banum. The compound of casein and lime, prepared from dotted ndlk,
is imputrescible, and is employed in distemper painting. (Gerhardt /ioc. ci^.)

If well washed casein, while stQl moist, be digested with water containing 0*0005 per
cent hydrochloric add, it dissolves completdy. The liquid, filtered from a trace of fat,
deflects the rays of jpolariBed light to the left, and has all the characteristics of a solu-
tion of albumin, (^ouchardat)

* Tho aabei raried between 1*6 and 5*4 p«>r c
t See ** Physiological Sourcea of Ca«eln.* (p.

cent. The labttanoe was dried 150** C.
Bit.)

812 CASEIN.

Oifone acts energetically npon casein, the casein being apparently first oonyerted
into a snbstanoe resembling albumin^ which is again destroyed on prolonging the action
of the ozone (Ghornp-Besanes, Jahresb. d. Chem. 1868, p. 63). O. DIaschke says
that he obtained by this reaction a crystallised compound of casein with a new acid
(ibid. p. 643). Concentrated hydrochloric acid tarns casein bine or violet, ibrming the
same products of decomposition as with albnmin. Tbnmn, from gall-nnts, precipitates
the most dilate alkaline solutions of casein. Mercuric chloride yields with soluble
casein a bulky white precipitate, soluble in acetic acid and in excess of alcohol : the
precipitate does not contain chlorine, and is probably identical with albuminate of
mercury (Eisner). Soluble casein is also precipitatea by aeetate and eubacetate of
lead, by o/um, merouroue nitrate, and sulphate of copper. The acetic acid solution of
casein is moreover precipitated hj ferrocyanide, chromate, and iodate ofpotaseium.

Casein yields the same products as albumin with sulphuric acid and add chromate
of potassium or peroxide of manganese (Guckelberger). When chlorine is passed
through ammoniaod solution of casein, a product is likewise obtained analogous to that
produced in the same way from albumin.

The coagulation of miUc by rennet (the mucous membrane of the fourth stomach of
young calves), is supposed bv liebig to result from the animal matter acting as a fer-
ment, and transforming the lactin of the nulk into lactic add; since milk coagulated
by rennet at a temperature of 40° C. always has an add reaction. It appears, how-
ever, that milk may be coagulated by rennet^ even when rendered alluiline bvthe
addition of small quantities of carbonate of soda, so that after coagulation the Lquid
still remains alkaline : it is only necessary to operate at a higher temperature (between
6(P and 60<^ C.) (Gerh. iv. 490.)

Sources and physiological nature of Casein. — ^When morbid bile is evwmted, a film
of coagulated mucus and of a caseous substance is formed (Fr eric hs, Hann. Ann. t.
pp. 1 and 2). Moleschott {Phyeiologie des SUoJfweehsels, Srlangen, 1S61. p. 366, &c^
found casein in tiie fiuid filling the interstices of cellular tissue, also in the interstitial
fluid of the neck-ba$id. M. S. Schultse found casein in the liquid impregnating the
middle lining of the arteries: in 100 pts. of the dried fibrous lining memlmme c? the
aorta thoracica, out of 17*4 — 23*1 pts. soluble constituents, 7*24 pts. casein ; and in the
middle lining of the carotid, which contains more contractile fibrous cells than the aorta^
in 39 per cent soluble pts. 21 pte. of casein were found. The juice of flesh appears to
contain casein ; at least this substance has been found in the liquid pressed fe>m flesh.
It is not certain that blood contains casein. Bumas and Cahours have extracted from
the coagulum of blood, a substance which has the same composition as, casein (see
analysis of casein), but is soluble in warm alcohol (Ann. Ch. Phys. [3] vL 415). Fre-
richs almost always observed in the soluble constituents of the contents of the trmaU in-
testine, albuminous compounds sometimes having the properties of albumin, sometimes
of casein. A substance resembling casein is extracted by boiling alcohol from the
contents of the small intestine of the human fietus, from the fifth to the sixth month
(L e h m a n n). The presence of casdn in the chyle is exceedingly improbable. (L e h m.)

When yoke of egg is treated with ether and water, a coagulum collects under the
yelloV stratum of mher. I^ after removing the ether, the coagulum be filtered off and
washed imtil the wash-water becomes only opaline by heat> a substance remains on the
filter identical with casein prepared by Bochleder^s or Bopp's method (Ann. Ch. Fharm.
xiv. 253 — 6 ; Bopp, ibid. Ixix. 16 — 37), only that it contains a litUe albumin poor in
salts; the albumin was predpiteted by diluting the yoke solution with water (Gmelin,
Handbuch, viii 2, 282). Casein has been said to exist in urina chylosa. Beveil
says that the urine of a child twenty-two weeks old, collected in his presence, con-
contained all the constituents of milk. Lehmann and Chevalier were unable to
confirm this statement Lehmann does not deny that albuminoidal substances may pass
into the urine, but with their properties so changed as not to agree with those of any
known albuminoidal compound.

Coagulable albuminate is sometimes found in the discharge of serous skin. Casein
is not contained in normal pus, nor has it been detected with certainty in abnonnal
pus.

The casein of human mUk is steted by Simon to be yellowish-white and very friable ;
it absorbed moisture from the air, and was but incompletely predpitated by alum or
by acetic add, from its aqueous solution. Casein from omifs mil% is less soluble in
water, and becomes visdd and homy on dnring. Canine milh gives a casein which
does not become visdd and homy when dried, and is less soluble in water.

The following are the percentages of casein in milk from various sources. (Gmelin,
Handb. viii. [2] 254, 5.)

CASEIN — CASSIA.

813

Human.

3'37 (Clcmm).
i7-9*l (Haldlen).
«8-M«(VernoIsaiid
Beoqoarel).

Goat.

4'M(Fif»)-
6*08 (Clemm).
6*51 (Vernoia and Bec-
querel).

Cow.

3*0-8*4 (BooulngRult).
4*16 averagv (PlftTfalr).
6*98 (Vanioto and Bco-
qiierel).

Sow.

8*46 (H. Scharer).
7-86 do.

Essex sow.

BrroH.

14-6 (Simon).
9-78^1S'6 (Domai).
11*68 ( Varaoli and Bee-
querel).

lA'S (Stiprlaan,LttiBclut,

and Bondt).
6*96 ( Vernoli and Bee-

querel).

Asa.

1*95 (Ptiigot).
I'TOGubler and Qu(-

Tenne).
8-57 (Vemols and Bed-

qaerel).

Maeb.

16*8 (Luisdus and

Bondt).
8*84 (Vernois and Bec-

querel).

The soluble casein of inilk is rapidly ooa^^ted by the gastric iuice, and then gra-
dually digested. Milk is the most indigestible of albuminous bodies. A dog digests
100 grammes of cheese in 8 — 3*6 hours ; boiled casein in 7 hours. R t. Schroder re-
marked that in the human stomach, 2*6 hours after fresh milk had been taken, casein
still remained in the form of amorphous or fifany transparent lumps ; and even after
the lapse of 3| hours, undissolved milk globules, adhenng to small ooagula of casein,
were almost always found, although the greater part of the milk seemed to have passed
from the stomach. Cheeses whidi are hard, fat, and poor in salts, are more difficult
of digestion than loosely coagulated, moist, and fresh cheeses (G-melin, Handb. iv.'
[2] 616). The digestibility of casein naturally depends upon its state of aggregation ;
the casein of human milk, which coagulates with sreat difficulty, is more readily
digested than that of cow's milk, which is more visdo. C. R L.

OASVnTfVBCMTASXa. See Lbouion.

MoM8ach$y CasaaWf Cassava Bread, is a kind of starch, obtained

from the root of the maniock {Jatropha manihot, L,) in the West Indies, where this
plant is indigenous. The root is grated to a pulp, which is strongly squeezed in bags
Dy a press. The juice contains nearly one-half per cent, of an ezceedmgly poisonous
matter, volatile, and therefore entirely dissipated by the heat on iron plates, to which
the pressed and crumbled pulp is exposed. Of that poison, as obtainea by distillation,
36 <uops served to kill, with horrible convulsions, in six minutes, a negro who had been
convicted of murder by poison. Cassava may be freed from woody particles by solu-
tion, filtration, and evaporation. If in this state it is exposed to heat on an iron plate,
it concrotes into mammellated small lumps, called tapioca^ an agreeable food, which i$
often imitated by means of potato-staifsh.

Cassava flotur may be distinguished, by the microscope,, from arrow-root, potato-
starch, and wheat-starch, by the ^hape of its paijtades, ^miph are spherules of ^^ of
an inch in diameter, while those of the second and third ftajjiB. ape ellipsoids, varying
in size ; and those of the fourth are spherule, dosterejl more or less together. U.

CASSBXi TBIAOIir. See Xbad, Oxychlobzdb of.

CAS8XA CAHTOWIX&ATA. The bark of Dicyfhdlhan earyophyUatiim
(Nees), a lauraceous tree growing in Brazil It has an agreeable taste of doves, an
aromatic odour, and contains, according to Trommsdorff, 19 per cent, resin, 8*0 tannin,
10 gum and phosphate of calcium, and 69 woody fibre. It also yidds an aromatic
volatile oil contaimng eugenic add. (Handw. d. Chem. 2** Aufl. ii [2] 820.)

CAB8ZJL CXnABKOVBAff Cinnamon Cassia, Chinese - Cassia bark, is the
bass or inner bark of Onnamonum aromaUcum, a lauraceous tree indigenous in China,
and cultivated in Java. It has a burning taste and aromatic odour, and contains, ac-
cording to Buchok, 4*0 per cent soft resin, 14*6 extractive matter, 64*3 woody fibres
and bassorin; volatile oil, &c. According to Mulder, it also contains tannic add
(Handwork) By distillation with salt water, it yidds oii of cassia, an oil mainly
consisting of dnnamic aldehyde, and nearly identical with the oil obtained from Ceylon
dnnamon.

OA88IA SViTOXJL* The fruit of Baeiyrilobium Jistvla, a leguminous plant
growing in India and in the interior of Africa. Accordmg to Vauqudin, it contains
14*8 per cent sugar, and 1*6 gum, together with pectin, gluten, &c. ; according to
Caventou, it contains cassiin. The legume is divided into a number of trans-^rse
cdls, filled witii a sweet, slight add pulp^ 100 pts. of which contain, according to Henzy :

Sugar. Gum. Tknniu. Yellow colooring Water.

matter and mucus.

West Indian . 69*2 2*6 3*9 1*3 23*2

African . . 610 6*7 13*2 — 19*0

The undeveloped flowers of Cinnamonum Louresii (Nees).
By distillation with salt water, they yidd oil of casna. (Handw.)

* Casein and extractlre matter : average of 89 persons (1 933—7 098).

814 CASSnN — CASTOEEUM.

OAJMOnr. A bitter principle obtained from Oasaia fistula. It ia §oIabIe in water
and in alcohol, and ia precif>itated therefrom by sulphuric, nitric^ or hydrochloric acid.
(OaTentoQ, J. Phainu Ti'ii. 840.)

CASazmunm. Native oxide of tin. (SeeTnr.)

OjywUTflBOVAVTA&ITB. Tantalite from Broddbo in Finland, oontainine
oxide of tin« (8ee TAMTALrra)

A pnrple compound of the oxides of cold and tin.
(See Gold.) ^

A syra^y imciyBtalliBable add, obtained, together with
oxalic and flaoeharic add, by oxidinng eane-sngar with nitric add. It forma a sp^u-
lorn with nitrate of ailver. The baruua-aalt appears to contain 0*H*BaK)'. (Siewer t
Institat XXL 78.)

CASTBUr AU JIlTfl. A mineral from the diamond sands of Bahia in BraaiL
It consists mainly of hydrated phosphate of jrttriqm, and occurs in imperfect erystals
or irregnkr grains, probably trimetnc, of greyish-white or pide yellow oolonr, nnctoons
adamantme Instre, harder than fluonpar, bat scratched by a steel mint ^Damonr
Institot 1853, p. 78.) ^ ^ '

C ABTZXAOTA Sl^AanciA. A Mexican scrophulariaceons plant, which yields
caoutchone.

A Gzystalline basic substance, obtained from the seed of Vitex Janus
castusy Zu It is bitter, insoluble in water, soluble in alcohol, ether, and adds ; forms
a crystalline hydrochlorate. (Landerer, Buchner^s Bepert Uy. 90.)

OAJiTOB. A variety of FnALTTB {q. v,)

OASTOmsuiC. BtbergeU^—A substance found in a pair of small sacs situated
in the genital oorsans of the beaver (Castor Fiber and Castor americmus). Ther« an
three sorts of it, Bussian, Bavarian, and American or Canadian. Of these^ the Bussian
is most valued, though the Bavarian is considered neariy equal to it Castoreum
when fresh, is soft and unctuous, but becomes hard and firm when dry ; it has a black
or brownish-blade colour, and is somewhat shining. It has a peculiar pungent odour
and a bitterish spicy taste, which irritates the &oat : it is used in medldne m an
antispasmodic.

According to Brandes, Bussian and Canadian castoreum differ oonsiderably in com*
position, as shown by the following table:

Vqhitileoil 1«00 2*00

Castoreum resin 1B'S6 58-60

Cholesterin — j^.2()

Castorin 0-83 2-60

Albumin 006 i-eo

Glutinous substance 2*30 2*00

Extract soluble in water and alcohol . . 0*20 2*40

Carbonate of ammonium .... 0*82 0*80

Phosphate of caldum • • • . . 1*44 |.^

Carbonate of ealdum 83*60 2*60

Sulphates of potassium, caldum, and mag-

nedum 0-20

Oelatinous substance exizacted by potash . 2*30 8*40
Gelatinous substance, extractable by potash,

soluble in alcohol 2*60

Membranes, skin, &c 20*03 3*30

Water and loss , 22*83 11-70

98-95 100*10

Wohler by distilling Canadian castoreum with water, obtained phone add, toffether
witii bensoic add and saUdn ; he suspected also the presence of ellagic and sSicylio
a<ad. Lehmann found bile in fresh castoreum, by Pettenkofer's test; also alkaline
sebates and urates, and an albuminoidal substance. Laugier, Bnmdes, Batka, and
Riegel, found bensoic arid. Lehmann found, as the mineral constituents of castoreum,
a small quantity of chloride of sodium, sal-ammoniac, and other soluble salts, also
phosphate of sodium and ammonium, and an abundance of phosphate of caldum and
phosphate of magnedum.

A substance resembling castoreum is likewise secreted by the prepuce (PnspuHum
perns and ditoridis) of man and of the horse. Lehmann gives the following tehle of
decomposition of: A. Fresh German castoreum j B. Smoked Bussian: C. Canadian-
D. Smegma praputii of the horse ,* R of man : '

CASTOEIN — CATAPLEnXE. 815

Ethereal extract
Alcoholic extract
Water extract
Acetic acid extract . .

„ „ consisting of •

carbonate of caldnm and al-

bnminoidal sahetance . . 2*4 3*4 6-8 2-8 5*6

Portions of skin ... o*7 9*4 18*4 268 18*5

7*4

2*6

8*2

49*9

62-8

67*7

64*8

41*3

9*6

7-6

2*6

1*9

4*8

6*4

6*1

14*2

18*6

21*4

6-4

9-7

100*0 100*0 90-9 99*9 100*2

The ethereal extracts contained saponifiable fats, cholesterin, and castorin, and a fki
whicb became very finely diyided in water.

Castoreum resin is obtained b^ eraporating the mother^liqnor of castorin {vid, inf.)
to dryness, exhansting the residue with water, then dissolving in alcohol, and eva-
porating. It is black-brown, shining^ brittle, nearly insoluble in ether, soluble in
aqneons alkalis^ and precipitated thereficom by acids.

Castareum-ailf obtainea by distilling castorenm with water, is pale yeUow, viscid,
sparingly soluble in water, easily in alcohol, and has a sharp bitter taste. Russian
castoreum yields 2 per cent of this oil; Canadian 1 per cent. (Handw. d. Chem. 2**
Aufi. ii [2] 1034.)

CABTQiMXM* A fittly substance obtained from castoreum. A solution of castoreum
in 6 pts. of alcohol saturated while warm, yields on cooling a deposit of ordinary feit,
and the mother-liquor deposits crystals of castorin by slow evaporation. This sub-
stance, when pimfled by repeated crystallisation, forms delicate, transparent, four^sided
needles, having a fiunt taste and smell of castoreum. It melts in lK>iling water, and
solidifies on coolinff to a hard translucent, pulverisable mass. It is but sparingly
soluble in cold alcohol ; ether dissolves it readily ; volatQe oils only when warm. It
appears to volatilise with vapour of wator. It dissolves without alteration in boiling
dilute sulphuric add, in strong acetic acid, in caustic alkalis. According to Brandes,
it forms a peculiar compound with nitric add. (Gerh. iv. 280.)

OA8TOS 030. This oO, much used in medicine as a purgative, is extracted from
the seed of Stcinus eommtmiSj a euphorbiaceous plant cultivated in the West Indies
and other warm dimates. It is visdd, yellowidi, odourless, and has a faint taste,
which becomes acrid when the oil is randd. It solidifies at — 18^C. Specific
gravity 0*969 at 12^ 0. It is distinguished from other oils by its easy solubiuty in
alcohol and ether. It is a mixture of several glycerides. When saponified by an
alkali, it yidds a soap peorfectly soluble in water, and from which mineral adds sepa-
rate a mixture of adds, oily at common temperatures, and consisting maiuly of ridno-
leic add, C^H'H)'. When this oily mixture is dissolved in a thira of its volume of
alcohol, and the solution is cooled to — 16^ or — 12^ C, it depodts a small quantity of
nacreous scales, apparently consisting of stearic and palmitic adds.

Castor-oil gives by analysis :

SauMure. Ure. Lefort.

Carbon . . . 7418 7400 74*68 74*36

Hydrogen . . 11*03 10*29 11-48 11*36

Oxygen . . . 14*79 16*71 13*94 14*80

100*00 100*00 100*00 10000

Ammonia converts castor-oil into ridnolamide, K.H'.C'H'H)'. When castor oil is
distilled with potadi, sebate of potassium remains in the retort, and an oily liquid
passes over, consisting of capiylic or oenanthyUo alcohol, and methyl-cenanthyl (see
Alcohols, p. 98). Castor-oil treated with a mixture of sulphuric add and add
chromate of potaisdum, yields cenanthylic add and hvdride of valeiyL Nitric add
attacks it witn violence, and converts it into OBnanthylic add. Peroxide of nitrogen
causes it to soUdify. Castor-oil dissolved in absolute alcohol, and exposed to the action
of gaseous hydrochloric add, is converted into glycerin, and contains ethyl-compounds
formed by the fattf adds previously in combination with the glycerin. Castor-oil
subjected to diy distillation, yidds hydride of cenanthyl and oenanHiyHc add, together
with small quantities of acrolein and solid &tty adds. (Gerh. ii 903.)

CKATAZiTBIBv or Contact action, — ^Terms applied by Berzelius and Mitscherlich
to those cases of chemical action in which a substance appears to induce decompodtion
in another body, without itself undergoing perceptible alteration, or at all events with-
out entering into combination with dther of tne dements of that compound. (See
Contact Action.)

A silicate containing zirconium, from the island Lamo, near

816 CATAWB ARITE — CATECHU.

Breyig^ Norway, together vith ziroon, leucophane, mosandiite, and tritomite. #ni«
perfect prismatio oystalB, with perfect basal deaTage. Specific graTity 2*8. Hardness
near 6. Opaque, with light yellowish-brown colour, and little lustre. Melts easily
to a white enamel before the blowpipe on platinum ;.givei) a colourless elass with
borax; blue with cobalt-solution. Dissolves easily iA hydrochloric add^rithout
gelatinising. Mean of analyses :

SiO« Zr«0« A1*0» NaK) Ca»0 FeH) HK>

46-67 29*67 0*92 10*46 413 0*56 8*96 » 101*26

agreeing nearly with the formula 3(M?O.SiO*) + 2(Zr«0*.8SiO«) + 2aq., which if dr-
conia be regarded as a protoxide (rr » |Zr), may be reduced to that of a metasilieate
(M'2T*)Si*0*-f aq. (Weibye and Sjogren, Pogg. Ann. Ixxix. 299 ; Dana, ii. 308.)
OATAHTBAXITBa A name g^yen by Lieber (SilL Am. J, xxriiL 148), to a
rock which accompanies itaoolumit^ and appears to stand, as a magnesium rock or
slate, between itacolumite and itabirite.

OATBOUUt formerly called also Terra japoniea, is an extract rich in tannin,
obtained by boiling in water the parts of several plants growing in India, and is dis-
tingoished into tl^ee sorts in commerce. 1. Bombay Catechu, from the Areea
cateohuy is prepared by boiling the fruit of the areea palm in water, the first portions
of the decoction being the strongest, and affording the quality called Caeeut the latter
portions, the weaker sort called Coury, The best occurs in dense irregular lumps of a.
a dark brown colour. -It is opaque, with an even, slightly unctaous, shining fracture.
Another variety called ctUecku verum has a somewhat reddish-brown colour, a fatty
lustre, a splintery concho'idal fracture, and is translucent on the edges. Bombay
catechu is almost entirely soluble in boiling water, yielding a dark brown liquor, very
rich in tannic add, and affordmg copious predpitates with solution of glue and with
sulphuric add.

2. Bengal Catechu, is obtained from the Acaeia {Mimosa) Catechu, by boiling
the twigs and imripe pods in water. It has a lower specific gravity, is of a pale brown
colour, with a yellowish cast. It is opaque, with a glimmering lustre on the frac-
tured surface only, and traversed by dark brown shinug stripes. When treated witii
cold water, it leaves a large redduum, but boiling by water it is mostly taken up ; the
solution contains less tannin, but more caiechin, than the Bombay sort

3. The third kind, called Gambir Catechu, is referred to the Naudea (Uncaria)
Gambir, from which also kino is obtained. It occurs in cubical pieces of 1 to 1 j^ inches,
opaque, and of a brown yellow or bright yellow colour. Their fracture is even and
dull. It is little soluble in cold water, but almost completely In boiling water, the
solution affording copious raedpitates with glue and sulphuric add.

4. A fourth kmd called Egyptian or Nubian Catechu, is said byLanderer to be
obtained by the collectors of gum by boiling the fruits of gummiferons acadas, and
to be exposed fbr sale in the bazaars of Smyrna, and at Constantinople. It is for the
most part soluble in water, but differs from the other varieties in many respects.

All kinds of catechu dissolve in great measure in alcohol; and soften with heat.
The specific gravity of good Bombay catechu is 1*39 ; of Bengal catechu 1*28 ; and of
the Qambir variety, 1*40. Catechu is used as an astringent in medidne, and for tan-
ning leather, either alone or mixed with oak bark. The comparative value of catechu
for tanning may be measured by the proportion of gelatin which' is required to precipi-
tate all its tannin. Catechu is also used in dyeing, espedally for silk and wool. When
treated with nitric add at 46^ C, it yields a brijght yellow powder, possessing all the
properties of picric add, but much more soluble in water. Suk and wool may be easily
dyed in the aqueous solution.

Catechu has lately been much used to prevent the fbrmation of boiler incrustations,
or to remove them when formed ; the quantity required is such as will slightly colour
the water. (Newton, Bep. of Patent Inventions, 1868; DingL poL J. cxlviii. 316.)

Catechu is mainly composed of two prindples, catechin and cateckuiannic aad,
together with a brown colouring matter.

Catbchin, Cateckucic acid, or Tanninffenic acid, is obtained from Bengal catechu,
by digesting it for 24 hours in cold water to extract the tannin, and then boiling the
residue several times with water. The yellow catechudc add which depodts itself during
the cooling is to be collected upon a filter, washed repeatedly with cold water, and
finally dissolved in six times its weight of water with purified bone-black to decolorise it-
White catechucic add separates from the hot filtered solution as it cools. It is now
to be washed on a filter with cold water, quickly dried on bibulous paper, and more
completely under the recdver of the air-pump. Other processes, but less simple, have
been prescribed

Pure catechin is a white powder composed of veiy small silky needles. It dissolves
iu 1133 pts. of water at 17^ C, forming a colourless tasteless solution, which has no

CATHA EDULIS— CATHODE. 817

effect on the oolour of litmuB ; it diBsolyes in 3 pts. of boiling water (forming a solution
said to haTe an acid reaction), in 5 or 6 pts. of cold alcoho^ 2 or 8 pts. boiling alcohol
120 pts. of cold ether and 7 to 8 pts. boiling ether. According to Zwenger^s analysis
it contains 61*8 per cent, carbon and 4*8 hydrogen, whence Zwenger deduces the formula
C»H>«0«.

Catechin melts at 217° (Zwenger), and solidifies to a translucent^ am(«phous» brittle
mass. After diying at 100° C. it giyes off 4*4 per cent water when melted. When
heated aboye its meltinff point, it turns brown, and intumesces, giying off water and
carbonic acid. By dry distillation it yields an empyreumatic oil and an acid watery
liquid, which yields by eyaporation crystals of pyrocatechin or oiyphenic acid {q, v.)

Dilute mineral acids dissolve catechin without altering it ; strong acids decompose
it ; with strong sulphuric acid it forms a deep purple liquid.

Catechin does not form definite compounds with bases. It absorbs ammonia, but
giyes it up again in yacuo. The fixed alkalis colour it yellow, brown, and black. It
does not decompose alkaline carbonates, or precipitate the solutions of hydrate or
acetate of calcium or barium. It forms a white precipitate with acetate and subacetate
of lead ; dark green with ferric chloride ; greenish-black or yiolet with ferroso-ferric
sulphate ; brown or black with sulphate of copper; brown or black with salts of silver,
gold, and platinum, the metals being reduced. These decompositions often take place
after a time only, or on heating the liquid, and are always accompanied by decompo-
sition of the cateehin. Solutions of gelatin, starch, tartar-emetic, and salts of quinine
or morphine, are not precipitated by catechin. (Gerh. il 882).

Gatechu-taknio Aoid. Cachoutannie acid. Tannin of Catechu. To ob-
tain this acid, the aqueous infusion of catechu is heated with dilute sulphuric acid,
and after the liquid has been clarified from the colouring matter, &c, thereby thvwn
down, strong sulphuric acid is added as long as a precipitate continues to form. This

Oitate is washed on a filter with dilute sulphuric acid, pressed between paper, and
red in pure water, the solution digested with carbonate of lead, the solia matter
thrown on a filter, and the filtrate evaporated in yacuo. The product thus obtained is
purified by re-solution in ether containing alcohol. Another mode of preparation is to
exhaust powdered catechu with ether in a displacement-apparatus and evaporate the
ethereal solution. A yellowish porous mass then remains resembling gallotannic acid.

Cachoutannie acid has a purely astringent taste, and resembles gallotanic acid in
many of its properties, but is distinguished therefrom by not precipitating tartar-
emetic, and by forming a greyish-green precipitate with ferric salts. It does not
precipitate ferrous salts. It is soluble in water, alcohol, or ether, insoluble in oils
both fixed and volatile ; its solutions are precipitated by gelatin. It is but slightly
soluble in water acidulated with sulphuric acid, though more so than gallotannic acidL

According to Pelouze, catechutannic acid contains C"H"0".

Catechutannic acid softens when heated, and yields by distillation a yellow empy-
reumatic oil, together with a watery liquid which gives a greenish-grey precipitote
with ferric salts, and is coloured brown by alkalis.

The solution of catechu-tannic acid alters quickly by exposure to the air, becoming
red, and leaving on eyaporation a substance which no longer re-dissolves completely in
water. According to Delffs, catechin is one of the products of the decomposition.

The salts of catechutanuic acid are too unstable to be prepared in the pure state.
The potassium-salt is veiy soluble, and precipitates gelatin after addition of an acid.
The catechutannates of the earth-metals and heavy metals form sparingly soluble pre-
cipitates.

O ATBA BBVXAS. The leaves of this plant, called K/U by the Arabs, are brought
from the interior to Aden ; they are said to produce sleeplessness and an agreeable
state of excitement

CATKASTIW. The purgative principle of senna (the leaves and fruits of several
shrubs of the genus Cassia, order Leguminosa). It is prepared by evaporating the
alcoholic extract of senna, redissolving in water, precipitating with acetate of lead,
separating the excess of lead from the solution by sulphuretted hydrogen, and evapo-
rating the filtrate. It is a brownish yellow, uncrystalusable, diaphanous mass, soluble
in water and alcohol, insoluble in ether ; its taste is bitter and disgusting. By dry
distillation it yields products free from nitrogen. Alkalis turn it brown ; with sub-
acetate of lead and tincture of ^alls, it forms yellow precipitates (Lassaigne and
Feneuille, Ann.Ch.Phy8. [2]xvi. 18). Winckler(Janrb.pr.Pharm.xix. 223) applies
the term cathartin to a bitter substance contained in the berries of the buckthorn
(Rhamnus catharticus). (See Bkamko-Cathabtin.)

O ATBOBBf or Kathode, — Faraday's term for the negative pole or electrode in the
voltaic circuit, the elements there ehminated being called cations, or kations, (See
Anion, p. 296.)

Vol. I. 3 O

8 1 8 C ATLINITE ~ CELLULOSE.

A roddish clay stone from the Goteau de Prairiefl^ ireet of the
Hiasifisippi (Jackson, SilL Am. J. xxxy. 388.)

CAT'S STB. A traasliicent quartz of beautiliil appeavance biooglit from Ceylon*
Its colours are gieen, grey, brown, and red of Tarioas shades, f^raeture imperfectly
conchoi'daL Translucent with Titreous internal lustre. It derives its name from a
peculiar play of light (chatoyant), arising from fibres interspersed. It scratches quartz,
IS eaaQy broken, and resists the blowpipe. Specifie gravity 2*64. Ooatains, according
to Klaproth, 96 per cent silica, 175 aiamina, 1*6 lime, and 0*25 oxide of iron. It is
Yalned for setting as a precious stone. U.

CAnoVBTUbOf. A resinous medicinal preparation obtained in North
America from CaulophyUum Halictraides. (Buchnei's N. Bepert vi. 188.)

PAVBTXCXTTa The quality possessed by strong alkalis, acids, nitrate of sil-
rer, &e., of corroding the skin and flesh of animals. In the old language of suigeiy,
caustics were diridedinto the actual, such as red-hot iron and mora, and the poten-
tial, sooh as the above-mentioned preparations.

CAVOZhlB 1TB. See Kbfhxlzn^

CAW% A miner^s term for native sulphate of barium.

OBSAJIv OX& OV (not to be confounded irith OUum de eedro, whidi is one of the
names of (»1 of citron). — A volatile oil obtained from the wood of the Virginian cedar,
Jwiiperus Virginiana, which is used for making pencils, and owes its agreeable odoor
to this oil. It is a soft semi-solid mass, consisting criT a liquid hydrocarbon, cedrene,
C**H^^ and an oxygenated camphw or stearoptene, oontainiz^ G'*H*0.

To obtain the camphor, the crude oil is distilled; the distillate is pressed between
lineu or calico, to free it from the greater portion of the liquid cedrene whidx adheres
to iC and then crystallised from alcohol of ordinary strength, whi<^ retains the rest
of the cedrene in solution.

Cedar-camphor thus purified is a ezystalline mass of great beauty and lustre, having
an aromatic odour, like that of pencil -wood, but not much taste. It melts at 74P C.
and boils at 282^. Yaponr-densibr » 8*4. It dissolves very sparingly in water, but
freely in alcohol, whence it ciystalHses in needles having a silky histre. It gives by
analysis, 81 per cent carbon and 11*8 hydrogen, agreeing with the preceding formula;
hence it is isomeric with camphor of cubebs (q. v.) By distillation with phosphoric
anhydride, it is resolved into water and cedrene, C"fi»0 = C'»H»* + H*0. With
pentachloride of phosphorus, it yields an aromatic substance, which has not yet been
analysed. Strong sulphuric acid colours it strongly and separates an amber-ooloured
oil (Walter, Ann. Ch. Phys.|^3] L 1. 498). According to Bertagnini (Compt. rend.
xxzv. 800), oil of cedar combmes wth the acid sulphites of the alkali-metals.

CBDBBVB. C'El*^. — This body is produced from the concrete portion of cedar-
oil by the action of phosphoric anhydride. It is oily, aromatic, ana has a peppeiy
taste. Specific gravity 0984 at 16^ C. Boils at 248^. Vapour-density 7*5 (4 toL)
(Walter, loc, cit,)

See CsDAOK.

IT. One of the products obtained by Beichenbach (J. pr. Chem. i I)
from the tar of beech-wood; said to crystallise in fine needles. Volckel (Ann. Ch.
Pharm. Ixxxvi 331) was not able to find it.

CBBBOV. Simaha Cedron (Planchon). — ^A tree which grows in the hottest parts
of New Granada, and bears fruits resembling the bean of St. Ignatius ; they have a
bitter taste, and are used in that counta^ as medicine. Ether extracts from them a
neutral dystallisable fat, insoluble in coid alcohoL The fruit, after exhaustion with
ether, yields to alcohol a crystallisable substance, cedrin, which Lewy regards as the
active principle of the fruit. Cedrin is sparingly soluble in cold water, more soluble in
boiling water and in alcohol, and crystaUises from the solutions in silky needles. It
is neutral, and has an intensely and persistently bitter taste. (Lewy, Compt. rend,
xxxii 610.)

OBXiBSTIVa Syn. with Ccelbstin.

CBZAmLZC ACXB. Syn. with MBTAFBcno Aon>. (See Pictio Aom.)
CB&Xiir&OBB. C•H1*0^ Lignin, Woody fibre. Ligneux, ZeOetoff, PlarufetLeeU-
staff, Pflaneenfaaerstoff, (Payen, FriciB de Chimie tndustrieOe, 4-« 6d, ii. 11 ; Gerh. ii
481 ; Gm. xv. 123.) — ^This substance constitutes the essential part of the solid framework
of plants. The cell-walls in the early stages of their development are composed en-
tirely of it, but as the plant grows, they become incrusted with colouring matter, resins,
and other foreign substances, which in some parts, as in the heart-wood of large trees,
fill up the entire cavities. Some tissues, however, consist almost wholly of cellulose,
e,g. the pith of the rice-paper plant (Aesckynomene paludosa), and the homy peii-

CELLULOSE. 819

gpenns of certain Beeds, as those of the phytelephas or v^etable iroiy, the date-tree,
dragon-tree, ^c. Several mannfaetored yegetable fabrics, as cotton, linen, hemp, and
unsized white paper, consist of cellulose yery nearly pure.

Cellulose has also been said to exist in the animal kingdom, oonstitnling the chief
part of the mantle of mollusea, and according to Fr^my, of the testa or integument of
insects and crostacea ; fiom the analysis of other chemists, however, these substAuces
appear to be nitrogenous (see Chitik). According to Yirchow (Compt. rend, xzxvi.
492, 860), cellulose is found in degenerated human spleen and in certain parts of the

brain.

The easiest method of obtaining pore oellulofle, is to wash white cotton, unsized
paper, old Unen, or elder-pith, with a hot solution of caustic potash or soda, then
with cold dilute hydrochloric add, then with ammonia, washinff thoroughly with water
after the application of each of these reagents, and lastly wiu alcohol and ether ; it
is often necessaty to repeat this series of operations two or three times. To obtain
pure cellulose from wooa, it is necessary, after boiling the wood with ^tash till the
Uquid is almost dry, to treat it with chlorine-water or with a weak solution of chloride
of lime, repeating these successiye operations several times, in order to free the cellular
tissue from the encrosting matter which is so intimately united with it The vege-
table fibres in the excrements of herbivorous animals ftimish a convenient source of
cellulose, because the encrusting matter has been already removed or disintegrated to
a great extent by the prooiss of digestion, so that the cellular substance which remains
is mudi easier to punfy than the tissue o^ the plant in its natural state.

Cellulose tiins purified is white, translucent^ of specific gravity about 1*5, insoluble
in water, alcohol, ether, and oils, both fixed and volatile. When quite pure, it is un-
alterable in the air ; but as it exists in wood, in contact with asotiBed ana other easily
alterable matters, it gradually decomposes in moist air, undeigoing a slow combustion,
and being converted into a yellow or brown friable substance cafled touchwood.

The state of aggregation of cellulose varies with its ori^. In its less compact
forms, as in Iceland moss, it is easily disintegrated by boilmg with footer, and con-
verted into a soluble substance, viz. dextrin ; but in its ordinary denser form, as in
wood, linen, cotton, &c. it resists the action of water, and even of moze energetie
■olvents, for a long time.

Strong sulphurte and pkoiphorie acid disintegrate ceUnlose at ordinary temperatures,
and convert it into dextrin, a substance isomeric with cellulose, without colouring
it; if water be then added and the mixture boiled, the dextrin is converted into
glucose. Thin stripe of paper or linen, triturated with strong sulphuric add added drep
by drop^ are converted, after some time, into a viscous mass consisting of dextrin, and
on boiling this maiss with water, it acquires the property of reducing copper-salts in pre-
sence of an alkali, and after some hoius* boiling is completely convertea into elucose.

Unsized paper plunged for a few seconds into sulphuric add diluted with half to a
quarter its bulk of water, and then washed with weak ammonia, undergoes a very re-
markable alteration, being converted, without change of composition, into a tough sub-
stance very much resembung animal parchment, and applicable to the same puroosee.
The formation of this remarkable substance was first noticed in 1847» by Jnessrs.
PoumarMe and Fi^er, who ^ave to it the name of FapyritL The discovery re-
mained, however, without practical application till the year 1857, when it was again
brought into notice and patented in this country by Mr. W. K Caine; and the ma-
teria^ called vegetable parchmentt or parchment j^aper, is now manufactured in large
quantity by Messrs. De la Bue and Co. Besides its application to the same purposes
as ordinary parchment, it is largely used for covering pots in which preserves and
jellies are kept-, and for making shirt-collars, imitation jace, &c. &c. ; it is also very
usefol in the laboratory, for connecting pieces of apparatus in distillations, and as an
intervening membrane in ejroeriments of difiusion, osmose, &c. That it should have
remained so long unnoticed after its first discovery is probably due to the circumstance
that Messrs. PoumarMe and Figuier, in preparing it, used strong sulphuric acid, of
specific gravity 1*842 ; and it has since been found that the material thus produced,
though possessing the general characters above described, is not nearly so tenadous
as that obtained with add diluted to the extent already mentioned. (Hofmann,
Ann. Ch. Pharm. cxii. 243.)

Cellulose (linen, for example), boiled fbr a short time with moderately dilute sul-
phurio or nitrio add, is converted into a pulpy mass, which still exhibits the compo-
sition of cellulose, and does not dissolve sensibly in water. Strong boiling hydrocMoric
acid converts cellnloee into a fine powder, without change of composition. Moderately
strong nitrio acid converts cellulose into a nitro-substitution-product, resembling
xy 1 oTdi n, CH'f N0*)0* (q.v.) With very strong nitric acid, or a mixture of strong nitrio
and sulphurio actdSf higher substitution-products are formed, viz. C*H'(NO')*0* and
C*H'(NO*)"0* called gun-cotton, or pyroxylin (q, v.)

3 q2

820 CELTIS — CEMENT.

Caustic potash or soda disintegrates cellulose but slowly, and with the more oompaet
Tarieties the effect is merely superficial. When equal parts of potash and cellulose
moistened with water, are heated in a closed vessel, hydrogen is evolved, and wood-
spirit distils over, while formic, acetic, and carbonic acids are produced, and remain
with the alkali. Melted hydrate of potassium converts cellulose into malic add.

Cellulose in all its forms is immediately blackened hjfiuoride of boron.

When chlorine gas is passed into water in which cellulose is suspended, the cellulose
is rapidly oxidised, with evolution of carbonic add ; the same effect is produced on
gently heating cellulose with the solution of a hypochlorite : hence in bleaching cotton
or linen fabrics, paper-pulp, with hypochlorites, &&, great care must be taken not to
use too strong a solution.

Cellulose in its more compact forms is not coloured by solution of iodine; but if
previously disintegrated by sulphuric add or caustic alkalis^ it produces a violet-blue
colour with iodine. In this manner, cellulose may be detected in vegetable tissues
under the microscope. Some lichens and algsB, Iceland moss for example, give the blue
colour with iodine after being boiled with water.

Solution of Cellulose. — C^ulose dissolves completely in an anmumuieal solution of'
oxide of copper. This solvent may be prepared by passing air £reed from carbonic
add into a bottle filled with copper turnings and half filled with ammonia; or by
placing copper turnings which have been oxidised on tiie sur&oe bv heating them in
the air and then reduced by dry hydrogen, in a tall glass v^^sel, and causing ammonia
,to drop through them into a bottle placed below ; or again, by directly dissolving
oxide of copper in ammonia. Silver-paper, or thin filtering-paper, dissolves in this
liquid after a while, forming a syrupy solution, which may be filtoied after dilution
with an equal bulk of water. On mixins the liquid thus fonned with excess of
hydrochloric add, the cellulose is predpitateain am<»phous flakes, which, after washing
with water, are colourless and quite firee fix>m copper. Even in ibis finely divided state,
cellulose is not coloured blue by iodine, unless it be first subjected to the action of
strong sulphuric add. (P a y e n.)

Several substances obtained from the solid tissue of plants, and formerly regarded
as distinct proximate pzindples, are now known to be mero modifications of cellulose ;
e. g. funginy from fangi, meduUin^ from the pith of various trees, &c Sordein, from
barley, is a mixture of cellulose with starch and a nitrogenous body.

OB&TIBa The fruit of CelOs orientalis contains 71 per cent of fleshy pericarp, and
28'3 seeds, the latter consisting of 67'3 husks, and 32*7 kernel ; 100 pts. of the kernels
contain 15'2 pts. oil, and 46*6 ash^ of which 40*4 pts. consist of carbonate of caldum,
and 4*4 of silica.

CBMBVT. The term cement is applied to any substance capable of holding to-
gether the surfaces of two bodies without mechanical rivets. Cements may be divided
into two classes, stony cements, and those of a resinous and glutinous character.

1. The chief stony cements are common building mortar, a mixturo of lime slaked
to a creamy consistence, and sharp sand, which hardens partly by diying, partly by
absorption of carbonic add from the air ; and hydraulic mortar, or Roman Cement, a
mixturo of slaked lime with amorphous silica, wluch hardens under water to a compact
mass of hydrated silicate of caldum. (See Silicates of Calciuil)

The mastic cement of London, much employed for giving to brickwork the hardness
and appearance of stone, is composed of ooHtic limestone, chiefly that of Portland,
finely ^und, mixed with sand and litharge, and made into a loosely coherent paste
with linseed oil, either raw or boiled. The oil is extemporaneously mixed by the
workman with the cement powder on a board b^ a trowel, and plastered thinly and
smoothly over bricks, laths, or any surfi&ces which aro to resemble stones. The fine
dust produced by sawing stone slabs, is said to answer a like purpose, when mixed
with litharge and oil. ijialysis shows that the said mastic is composed of 35 pts. of
siliceous sand, 62 of limestone, and 3 of litharge. These proportions may, however,
be somewhat varied without injury. Too much limestone impairs the hardness of the
cement ; too much sand makes it porous. For every 100 pts. of such a mixture, about
7 of oil are required. As this compost is friable, it may be made more ductile by-
keeping it compressed in moulds, for a little time beforo spreading it by the trow^
The si^ace to which it is to be applied, must be deaned and oiled beforehand with a
brush. It is particularly useful in dosing fissures in buildings, and preventing the in-
gress of moisture through seams.

2. Resinous and glutinous cements are of many different compositions. Bosin and
beeswax melted together, and thickened with more or less fine brickdust, serve for
cementing glass and metal works. Asphalt mixed with chalk in due proportion has
been used extensively for paving streets and terraces. The bitumen of Seyssel and
Lobsann in France, has been largely employed for this purpose. The compost rendered
nearly fluid by heat^ is applied to bodies dried, and if convenient, previously heated.

CEMENT. 821

Coal tar mixed with sand, foims a bad composition, which becomes finable and porous
by exposure to weather.

Seven or eight parts of rosin, and one of wax, melted together and mixed with a
small quantity of plaster of Paris, form a very good cement to nnite pieces of Derby-
shire spar, or other stone. The stone should be made hot enough to melt the cement,
and the pieces should be pressed together as closely as possible, so as to leave as little
as may be of the cement between &em : this is a general rule in cementins, as the
thinner the stratum of cement interposed, the firaier it will hold. Melted sulphur
used in the same way will answer sufficiently well, if the joining be not required to
be very strong.

It sometimes happens, that jewellers, in setting precious stones, break off pieces by
accident : in this case thev join them, so that it cannot be easilv seen, with ^um-mastio,
the stones beinff previously made hot enough to melt it^ By the same medium, cameos
of white enamd or coloured glass are often joined to a real stone as a ground, to pro-
duce the appearance of an onyx. Mastic is likewise used to cement false backs or
doublets to stones to alter their hue.

The jewellers in Turkey, who are ^nerelly Armenians, ornament watch-cases and
other trinkets with gems by elueing mem. on. The stone is set in silver or gold, and
the back of the setting made flat to correspond with the part to which it is to be
applied. It is then fixed on with the following cement : Isinglass, soaked in water
tul it swells up and becomes soft, is dissolved in French brandy, or .in rum, so as to
form a strong glue. Two small bits of gum galbanum, or gum ammoniacum, are dis-
solved in two ounces of this by trituration ; and five or six bits of mastic, as bi^ as
pease, being dissolved in as much alcohol as will render them fluid, are to be mixed
with this by means of a gentle heat. The cement is to be kept in a phial closely
stopped ; and when used, it is to be liquefied by immersing the phial in hot water.
This cement resists moisture.

A solution of shellac in alcohol, added to a solution of isinglass in proof spirit,
makes another cement that will resist moisture.

So does common glue melted without water, with half its weight of rosin, with the
addition of a little rod ochre to give it a body. This is particularly useAil for cement-
ing hones to their frames.

Clay and oxide of iron mixed with oU, are said to form a cement that will harden
under water.

A strong cement, insoluble in water, may be made from cheese. The cheese should
be that of skimmed milk, cut into sUoes, throwing awa^ the rind, and boiled till it be-
comes a strong glue, which, however, does not dissolve in the watier. This water being
poured ofi| it is to be washed in cold water, and then kneaded in warm water. This
process is to be repeated several times. The glue is then to be put warm on a levigat-
ing stone, and kneaded with quick lime. This cement may be used cold, but it is better
to warm it ; it will join marble, stone, or earthenware, so that the joining is scarcely
to be discovered.

Soiled linseed oil, litharge^ red lead, and white lead, mixed together io a proper
consistence, and applied on each side of a piece of flannel, or even linen or paper, and
put between two pieces of metal before they are brought home, or dose together, will
make a close and durable joint, that wiU resist boiling water, or even a considerable
pressure of steam. The proportions of the ingredients are not material; but the
more the red lead predominates, the sooner the cement will dry, and the more the
white, llie contraij. This cement answers well for joining stones of large dimen-
sions.

The following is an excellent cement for iron, as in time it unites with the metal into
one mass : — Take two ounces of sal-ammoniac; one of flour of sulphur, and sixteen of
cast-iron filings or borings. Mix them well in a mortar, and keep the powder dry.
When the cement is wanted for use, take one part of this mixture, twenty parts of
dear iron borings or filings, grind them together in a mortar, mix them with water to
a proper consistence, and apply them between the joints.

Powdered ^uick lime mixed with bullock's blood, is often used by coppersmiths to
lay over the nvets and edges of sheets of copper in large boilers, as a security to the
junctures, and also to prevent cocks from leaking^

Six parts of day, one of iron filings, and linsMd oil sufficient to form a thick pastes
make a good cement for stopping cn^ks in iron boilers.

Temporary cements are wanted in cutting, giindini^ or polishing optical glasses,
stones, and various small artides of jewellery, mddi it is necessary to fix on blocks, or
handles, ftr the purpose. Pour ounces of rosin, a quarter of an ounce of wax, and four
ounces of whiting made previously red-hot, form a good cement of this kind, as any
of the above artides may be fastened to it by heating them, and removed at plea-
sure in the same manner, though they adhere very firmly to it when odd. Fitch,

80 3

822 CEMENTATION— CERANTIC ACID,

rosin, and a small quantity of taUow, thickened with brick-diisti is much used at
Birmingham for these purposes. Four parts of rosin, one of beeswax, and one of
brickdust^ likewise make a good cement^ which answers extremely well for fixing
kniires and forks in their hafSi ; bat the manufacturers of cheap articles of this kind
too commonly use rosin and briekdust alone. On some occasions, in which a Teiy
tough cement is requisite, which will not crack though exposed to repeated blows, as in
listening to a block metallic articles that are to be cut with a hammer and punch,
workmen usually mix some tow with the cement^ the fi^bres of which hold its parts
together.

Excellent water-proof cements are made from caoutchouc (p. 739).

The following composition is a good cement for electrical apparatus :— Five pounds
of rosin, one of beeswax, one of red ochre, and two table spoonfuls of plaster of
Paris, aJl melted together. A cheaper one for cementing yoltaic plates into wooden
troughs IB made with six pounds of rosin, one pound of red odire, half a pound of
plaster of Paris, and a quarter of a pint of linseed oiL The oehre and plaster of
Paris should be well dried, and added to the other ingredients in a melted state. — TJ.
(See Ur^a Dictionary of Arts, Man%ifiustiwru amd Mines, L 641).

CBMSHTATIOV is the process by which one solid is made to penetrate and
combine with another at a high temperature so as to change tiie properties of one of
them, without liquefaction taking place, being an exception to the general chemical rule,
that bodies do not mutually act on each other unless when one or more of them is
fluid. The conversion of iron into stoel by absorption of carbon into its inmost sub-
stance, from a mass of ground charcoal in which it lies embedded while exposed to
strong ignition, is one of the best examples of this process. A like change takes
place onpalladium, iridium, and platinum, in contact with charcoal or silica at a high
neat. When a compact mass of the oxide of nickel or iron is ignited in a crucible
lined and corered with charcoal, the carbon exerts its deoxidatmg and metallising
power to the very centrfi. The same phenomenon occurs with oompbct sulphate of
potassium or sodium encased and heated to redness in charcoal, these salts being therely
conyerted into metallic sulphides. These transformatioiis haye been aseril^ to the
progressiye production of the gaseous oxide of carbon, and to its absorption by the
metals, or its combination with the oxygen of the oxides or acids. U.

OBKBMT OOPnBf is the metal precipitated from the blue water of copper
mines or works by plunging iron plates into them. (See Coffer.)

OSWArazWa See GmooDr.

V r"l' W ^ w-T. m ■«»■— ^ hydrated silicate of calcium ooenzring in kidney-shaped
lumpsb together with other minerals, at Fund^ Bay. These^ lumps are coated with a
greenish crust resembling chlorite ; below this crust is a thin layer of cerinite ; within
this the centrallassite ; and the central ^rtion consists of cyanolitcw CentraUassito ex-
hibits a lamellated radiating structure ; it is white or yellowish, tranaluoent, britde^ of
spedflc gravity 2*45 to 2*46, hardness 8*5, and has an almost waxy lustre. It melts before
the blowpipe with intumescence to an opaque ^lass, and forms dear beads with fluxes.
It dissolves in hydrochloric acid without^latinliring. Its analysis is said to agree
with the formula 8GaK>.15SiO*+ 5aq. (H. How, mmh, K PhiL J. x. 847.)

OWBA&ZB. See JjPBCAJCUAxmJu

oaPBA&OTX. Cerancijthalote. — ^A name applied by 0 oner b e (J. Ohim. Med. x.
524) to a yellow elastic &tty substance^ insoluble in alcohol, but soluble in ether,
which he obtained from the brain. According to Fr^my and J. B. Simon, it is a mix-
ture of the cerebrates of potassium and sodium, with traces of olein and oleophoephorie
acid.

CSSABZA mOATAa A plant indigenous on the eoort of Africa, which
exudes an ambobrown resin smelling like olibanum.

CBRAZO ACZD. An acid containing C»H^O*, said by Hess (Ann. Ch. Pharm.
xxvii 3) to be formed by oxidation in beeswax; also supposed to be produced in the
preparation of oxalic or saccharic acid by the action of nitrio add on wheat-starch ;
existing also, according to Oppermaon (Ann. Ch. Phys. [2] xlix. 240), in a Brazilian
wax. Its existence has not been distinctly proved.

OMBJkXMm A name applied by Boudet and Boissenot (X Pharm. xiii. 88) to
the portion of beeswax which is sparingW' soluble in alcohol, and, according to their
statement, is not saponified by potash. It appears to be chid9y impure myndn, inas-
mudi as that body is not quite insoluble in aicohoL

roXlPBA&OTB. See Cbphalots. •

A,CXBm An add fbund by Braconnot (Ann. Ch. Phys. [3] xxL
484) in the fuel taken out of an antique lamp, proba^ of the fourth centmy. This
material was partiy soluble in boiling alcohol of 86°. The solution on cooling deposited

CERASm — CEREALS. 823

a white flaky sabstance meltang at 649 C, probably eerin : and tbe alcoholic mother-
liquor retained a substance, which remained after evaporation, as a white, hard, brittle
mass, melting at 61° C; its alcoholic solution reddened litmus, and by slow eyapora-
tion deposited small gpranular crystals. This more soluble substance Braconnot desig-
nated eerantic acid. The portion insoluble in boiliug alcohol contained myricin.

CBSASnr. The gum which exudes from the cherry-tree, plum-tree, and others
of the same family is only partly soluble in water. The soluble portion exhibits the
characters of arabin ; the remaining portion, which is called cerasin^ merely swells up in
water. Ceraon is colourless, semi-transparent, tasteless, and inodorous ; easily pul-
yerised, unciystallisable, insoluble in water and in alcohol, not susceptible of alco-
holic fermentation. Treated with nitric add, it yields 16*6 p. c. mucic acid. According
to G 61 is (Compt. rend. xliv. 144) ordinary gum arabic is converted into insoluble
oerasin by a heat of 150^ C. This artificial cerasin is reconverted into a soluble gum
by prolonged boiling with water, but again becomes insoluble when heated to 160^.

OXBASnni or OBUkSZTSi Syn. with Hobn Lbas.

OSRABVB. The wood of Oerasiu avium, the bird-cheny, contains 0'28 per cent,
the bark 10*87 per cent, of ash. The constituents of these ashes are as follows :

KK) Na«0 Ca*0 Mg«0 Pe<0» P»0» SO* SiO« CI
Wood. . 25*9 10*4 35*8 11*4 01 96 41 25 trace
Bark . . 79 165 447 64 0*2 8-6 0-8 21*8 0*4

The unripe fhiit of C, eofroniana contains a large quantitr of malic add.

C eapricida is known in Naples, and C, virginiana in Norm America, as deleterious.

OMRAXMm A mixture of wax iKth oil or lard, used by smgeons to screen ul-
cerated surfaces from the air. Sometimes watery liquids are inoozporated with the
mass, as subacetate of lead in lead-cerate. U.

L Syn. with Nephutb.

A nitrogenous substance dosely resembling diastase, obtained by
M&ge-Houri&s (Compt. rend, zxxvii. 861; xxxviiL 606; xlii 1122; zlviii. 431 ;
L 467) from bran. It is contained in the epispermium, the sixth membrane of the seed,
reckoning from without, and possesses the power of converting starch into dextrin,
sugar, and lactic add. The brown colour of bread made with flour containing bran
appears to be diiefly due to the decompodtion of a portion of the flour by the cerealin
ol the bran (see Bbbad, pp. 668, 660). Stiff stardi-paate is quickly converted into a
thin liquid by an infudon of bran at 40^ or 60^ C.

To isolate cerealin, bran is treated for six hours with dilute alcohol, the residue
pressed, and this treatment repeated three times, whereby the bran is freed from
sugar and dextrin, while the cerealin remains unaltered and undissolved. On treating
the reddue with water, the cerealin is dissolved, and the aqueous solution evaporated
at 40^ C. leaves it in the form of an amorphous albuminoid substance easily somble in
water, insoluble in alcohol, ether, and oils. The solution coagulates at 76^ C, also on
addition of alcohol ; it is predpitated in flakes by dilute ad£, not altered by neutral
rennet Its peculiar action on stardi is prevented by the presence of alkalis. Cerealin
once coagulated is no louger soluble in adds or alkalis, but still possesses the power of
transforming starch, though slowly. Cerealin retains its power of decomposing starch
at 70^ C, but not at hi^er temperatures, whereas diastase does not lose this power
below 90^ C. In other respects tne two bodies appear to resemble each other exactly.

According to recent investigation by Mouri^ bran frreed from cerealin, especially
the periaperwiwnj appears to to more active than cerealin itself and possesses the power
of converting starch even at 100^ 0.

CBBBAU. CereaUa, Geireide. — This name is applied to the grasses which are
cultivated for human food, vie wheat, barley, rye, oats, maize, and rice. They
are for the most part distinguished by the large quantitiee of starch, nitrogenous com-
pounds, and phosphoric add contained in their seeds, which constituents it is the object
of cultivation to develop as much as posdbl& The several kinds of cereal grain, ex-
cepting rice, contain nearly the same amount of nitrogen ; but in wheat-grain, the
nitrogenous matter (gluten) possesses a peculiar adhedveness, arising from the presence
of a glutinous substance <»lled ffliaditif which is wanting in the otiier cereals. It is
this property which renders wheat-flour so peculiarly adapted for the making of bread

(p. 667).

From the numerous analyses that have been made of the grain and straw of these
plants, we sdect the followmg :

Way and Ogston have determined the amount of water and ash in the grain,
straw, and chaff of wheat barley, oats, and lye with the following results (Journal of the
Boyal Agricultural Sodety, vii. [2] 693—678 ; Jahrosbor. d. Chem. 1849, p. 672):

80 4

824

TiBLB I.— ^nwuni 0/ ITaiir

and A>i, 4e. X

« Cmrtfc.

W,l»hlof 1

, !™

pu.of

Gnln!

laltH.

ofdrr

^s,:?

<llU

rii»

Gr.ln.

»rm-.

ciuir.

Cnfn.

*""■

ClulT.

°""— 1

Whit

H«pMoii

*■«

10-4*

. Itw

lys

IToo

I-3M

*■*"

lO-U
1*14

987

1-»M

. la-M

16-41

IJ-OO

IL-M

IMO

l-KO

4-61

1 M

IfDO

11-00

i-m

■M

t-0«

IMG

IIU

i-m

e»

141

1107

(p.ii

lO-W

I'HT

Spring

[a-<4

'»

IIU

ITS

-Sit

lain

. 1 -DO

Rriitol nd

'46

Cln.Hl rfd

l-am

61 B

■7<

Rpd.chiff IHii

•Ic ■ I -M

1«»T

■M

PJf»»Lhlckl

* : 1*M

low

JJJ

l-JO

Whllr-chlff"
S|.>1dt>.I

: Urn

IS:SS

i'siS

'frM

IIM

WbiM

■HI

■■

: *sj

1170

-f\

J:S

i«a

cWlng

■M

lO-fi!

il-00

];^

;5|

irM

iw?

i-a»i

1176

■71

I'M?

■M

ir-M

»-n

- 13-W

]'3S9

I6>64

IW . .

. IW

I»07

t* . 1 -»

list

-M

4-«

lOM

■»

■ I'M

law

■07

■w

!»-«

l-Kl

■ 11

»1»

irso

I '413

iVn

i«t

i-s«

f«0

I-M6

-H

»-TS

IMS

■OB

I'MI

E..UI.II .

- 000

lUO

porirt

rat.

•• ■ tw

1J - IMO

ChnillH

■ 10MB

MoVtoflu

'■ IMO
, . IMO

l-HS

ClKT^ir Cw

) ■ IMO

Oint

Ksr

i-Tsi

INHUb

: g

t<m

Unknown

: IH

Mil

Entllih .

• '**»

Specide tn>ltr o( Ibe min V.

rfnigbt fn lut. a( 1 buAd or mm I; i

AiBoimiofuh In liJopti. ofdiyVMin ,"

no „ 1

2
6

^ =i

. .4

¥■

|=n 3.1 S.

„„s

llS| l|5 11

s ilfiii

i„,

I-

Jt 1 1 |s 1 ES

1 ISSI II

1 l^ll

nil

1 111 5" -1

if!!!.,

8 X

JS 1 1 JS 1 ES

es;,

sSii ^£1 ZS

III

SS 1

1
i
i
1

' ill;

Hi ill III

i ^
I s

I !

5 I

! 1

• . 1 1

lUI

ins •
ini 1

- Ij -

Itil

826

CEREALS.

(rf

9
"fe.

£o 1^

feOg

Sulphur
in 100 pU.

of dry
Substaoce

s s

552

it it

a 2

2 *

1 1

Ji r i iiiii 3 I

III I 1 1 1 1 1 I I

«• «

I' 5

) Sims ! J

$ «

SS I I n 1 1 1 I II

Is I 5 sis IS 5 I «

5s 2 5 E££2| I I I

jt I 3 ssssg J

-* •-» T o

3 ' '

to o

I I s

■9 VlM W

i ' s

m* mm ^^

5r 4»

9 r « S '^

& 4; & -^•^- i * * S '^

<0 M

312

32 a 3 32SSS J J S 3 3 2

• :

I I

I ?

I I

C£BEALS.

827

s s
J 3ss s

flO CO

£ S S

Hut

2 2 2

•

IzV V

1 S 3

_S_

1 1 1 1 1

1 1 1

W« •.if

s s s

1 IIS 1

1 1 1

«• s »
• * a

5 ^« s

S S S

J JSS z

2 .E

z s

nsss

S 23

«-

'' ?• «

J 3:8 s

2 i t

^ at mm

4> S ^

90 t-

§1 2

• • • • •

• * • • 4 •

* IS'll'll

•
•

11'

111

»5 3

1 ^^

9 «»
! l1

T 5 r! ♦♦If

I 1

^ Il
° II

5 ^1

IS
€ •a

§4

t"-i

•-'u 00

II -^

9 C

828

CEREALS.

• ■ •

Ash in
100 pts.
of ory
Sub-
stance.

■

■c tiacei

• • • •

•

en — -*

• ■ ■ •

Chloride

of
Sodium.

— ^.-I- —

^<«^«:^

• • • • • a^

Chloride

of
Pous-
lium.

t 1

1 i II

1 1^1 ir

Phos-
phoric
Anhy-
dride,
P«0».

• - ■ ■ ■

Car-
bonic
Anhy-
dride.

1 i 11 M I M i

iHis

i^iSi 1

w *« 9» 'V e« lO ic « o*. M

M>»e«nao

• _ • • ■ • •

ic <o e<9 V ^ **

ODrfdOXO^

• • • • •
■oao — «o

• • • • •

O — S |St«« ■■eqp

■OCQMO

ri»fOiOOOOQDiftaBO-«

= 282**

»*« — — «»«

•

1
• 1

en
'S

1 •

r " '=3 * a

5 mi' •«

! tii

•SS g » .. H
o ".2 c S o"

S5 Sl

K ^ * QU *«| « » • *

6 :s iS

Authorities
(see p. 827).

> ,

^ « .

c
m

•a
a

tfO

9
u

CEREBRIC ACID — CEREBRIN. 829

Way and Ogston deduce from their analyses of the ash of cereals the following
general condnsions :

The amount of ash is not influenced in any definite nuumer by the nature of the
soil ; it appears, however, to be greatest on day soils, less on calcareous, and least on
sandy soils. The strongest straw contains the largest amount of ash. The amount of
ash in the chafif Taries in proportion to that in the straw, not to that in the f^^ain
(see Table L). The amount of ash in the grain yaries between much narrower limits
than that of the straw or cha£ It varies as much in different samples of grain grown
on the same soil as in samples from different soils, and bears no definite re&tion either
to dimate or to variety. But in all cases that were examined, the proportion of ash
in the erain was found to vary inversely as the total weight of grain in the crop ;
whence it would appear that the amount of mineral constituents abstracted £ix)m the
soil by the grain Ib the same whatever may be the actual weight of the crop.

Not onlv the amount, but likewise the composition of the ash appear to be inde-
pendent of the nature of the soil : the predominance of any constituent^ lime or silica,
for example, in the soil by no means leads to a predominance of that same constituent
in the plant. Neither does it appear that different bases have any tendency to replace
one another in plants. An abundance of soda in the soil or the manure does not cause
that alkali to take the place of potash in the plant. Other chemists have, however,
furived at different condusions rdatins to this point. (See Daubeny, Chem. Soc.
Qu. J. V. 9; xiv. 216. — Malaguti and Durocher, Ann. Ch. Phys. [8] liv. 257.)

The difference in the amount of ash in the grain, straw, and chaff relate only to the
silica ; if this be deducted, the remainders exhibit no perceptible difference.

The ash of the grain of barley and oats differs from that of wheat-grain only in the
much Isrger amount of silica contained in the two former ; if this be deducted, all es-
sential differences vanish.

For frirther details, see the names of the several cereals (Baslbt, under Hobdettx) ;
also the artidee Soils and Manubss.

OBSBBSZO ACnOD. (Fr^my, Ann. Ch. Phys. [2] IvL 168; v. Bibra, Ver-
aleichende XInteriuchwngen vW das Gehim der Mmschen und der WirbdtlUere, Mann-
heim, 1854.)— A fatty add contained in the brain. It is obtained by cutting brain
into thin slices ; treating it repeatedly with boiling alcohol to deprive it of water ;
pressing it ; digesting fint with cold then with warm ether ; distilling off the ether
from the solution ; and digesting the slimy residue with a much larger quantity of
ether. Cerebrio add then remains as a sooium-salt mixed with phosphate of calcium,
oleo-phosphoric add in the form of a sodium and caldum-salt, and brain-albumin.
To purify the product, it is digested in boiling absolute alcohol dightly acidulated with
sulfuric add, which leaves the caldum and sodium undissolved as sulphates, while
the alcohol takes up the cerebric and oleo-phosphoric acids, and deposits them on
.cooling. Lastly, the mixture is washed with cold ether, which dissolves the oleo-
phosphoric acid and leaves the cerebric add, which is finally purified by reciystal-
using it several times fr^m boiling ether.

Cerebric add has a white, granular, crystalline aspect ; it is soluble in boiling al-
cohol, insoluble in cold ether, easily soluble in boiling ether; in boUing water it swells
up^ but does not diraolve. It mdts at a temperature near that at which it begins to
decompose, and when more stronglv heated bums with a characteristic odour, leaving
a difficultly combustible charcoal with a decided add reaction. It consists, according
to Fr^my, of 66*7 per cent carbon, 10*6 hydrogen, 2'3 nitrogen, 0*9 phosphoros, and
19-5 oxygen. According to Muller and v. Bibra^ the phosphorus is not an essential
constituent

Cerebric acid is a weak add, but nevertheless forms salts with all bases. The am-
moniwn-^ potassium', and sodium'SaltB are obtained as predpitatee, nearly insoluble in
alcohol, by placing an alcoholic solution of cerebric add in contact with the respective
alkalis. JBaryta, stroniia, and lime unite directly with cerebric add, and deprive it of
its property of forming an emulsion with water.

C8RBBKZV. This name has been applied to several substances obtained from
brain. Fourcroy in 1793 (Ann. Chim. xvi. 283) obtained a substance which was
called cerebrin, brain-fat, or phosphoretted bile-fat, and was probably a mixture of
Fr^my*8 cerebric acid with the substance which separates aft'er some time from al-
cohol in which anatomical preparations containing nerves or brain have been pre-
served. Chevrcul applied the same term to a substance obtained from blood-serum,
probably a mixture of fats and glycerides containing phosphoric add. Lastlv, G ob 1 ey
(J. Pharm. [3] xviii. 107) designates as cerebrin, a substance obtained chiefly fix>m
carp's eggs, and agreeing essentially in composition and properly with Fr^my's cere-
bric acid, excepting that it does not exhibit any tendency to combine with bases.

W. Muller (Ann. CL Pharm. cv. 361) has obtained a substance analogous to

880 CEBEBROL — CEBIN.

FrimfB cerebrin, by tritnntmg bmn to a thin pulp with water, heating the muctmw
to the boiling point, and treating the separated ooagnlnm with boiling aLcohoL The
alcoholic extract filtered at the boiling heat deposits a mixture of cholesterin and eere-
brin, together with other subetanoes ; and on treating this mixtare with cold ether,
cerebrin remains behind, and may be purified by repeated crystallisation from boiling
aloohoL It then forms a snow-white powder composed of microscopic sphemlcs, agree-
ing with Frdmy's cerebric acid in most of its properties, especially in swelling up in
water like starch, and forming an emnUdon. It contains 68*46 per cent carbon, 11-20
hydrogen, 4*61 nitrogen, and 16*66 oxy^n, whence Mttller deduces the emmriod for-
mula C^'H^NO*. It does not dissolve in alkalis or in dilate adds, but is decomposed
at the boiling heat by hydrochloric, snlphnrie, and nitric acid. The product of its
decomposition by nitric acid is a non-aaotised white waxy body, soluble in sloohol and
ether. Treated with strong sulphuric add in the cold, it dissolves with dark purple-
red colour, and the solution mixed with a large quantity of water becomes ooloudess,
and deposits a yellowish, tenacious, flocculent substance.

It is most probable that the cerebrin of Gobley and Muller, the cerebiote of Conerbe^
and the cerebric add of Fr6my and t. Bibra contain, as their essential constituent^
one and the same substance, wnich is likewise pvesent in cephalote and steazoconotei
(Handw. d. Chem. 2*« Aufl. ii [2] 888.)

CBUttBOXi ^Berzelius). EUent-oarebrol (QovLeThe). — ^An oily reddish sub-
stance, insoluble in water, soluble in alcohol and ether, obtained by Couerbe
(J. Chim. m^ ii. 766 ; x. 624) from brain. According to Fr^y, it is a mixture of
olein, oleo-phosphoric add, cholesterin, and cerebric add.

OWMMBMO'&WTMAJL WLVTDm A serous fluid contained in the sub-arachnmdal
cavities, and forming a liquid atmoerohere round the brain and spinal marrow. It
belongs to the class of serous transudates, and is generally distinguished by its yeiy
small amount of solid constituents, espedally of organic matter. These constituents
are albumin, traces of fat, extractive matter, and the inorganic salts of blood-serum.
It contains also a substance which reduces cupric salts, but differs from glucose in not
being resolved into alcohol and carbonic add by fermentation. According to F.
Hoppe (Chem. CentralbL 1860, p. 42) this substance is soluble in water and in abso-
lute ucohol, does not crystaHise, dther jper se or with chloride of sodium, is not predpi-
tated either by neutral or basic acetate of lead alone, but yields a predpitate with the
latter in presence of ammonia. It is decomposed by putrefaction^

Hoppe and Schwabeiv analysed the cerebro-spinal fluid obtained by puncturing, in
two cases of J^na bifida and two of Ej/droc&pXcUus inUmus, with the following re-
sults :^-

Splna bifida. Hydrooephalaa

Water .
Soiled matter

Albumin •
Extractive matter
Soluble salts .
Insoluble saltfi

Puncture. II* Puncture. I. Puncture. II. Puncture.

989*33 989-80 979*01 989*63

10*67 10*20 20*99 10*47

0*26 0*66 11-79 0*70

2*30 200 1-82 1*67

7^7 7-20 7-64 7*67

0*46 0*46 0*36 0*63

The fluids from the Spina bifida were strongly alkaline and perfectly transparent
The first reduced cupric oxide, the second did not. The second hydrocephalic Uquid
also exhibited the reducing action. The greater amount of albumin in the first hydio-
oephalic liquid was due to previous inflammation of the transudent yessels. (Handw.
d. Chem. ii. [2] 891.)

cnnUBKOTB. (Couerbe, Ann. Ch. Phys. [21 Ivi 164.) Brain-wax, Sim-
waeheiL, G-melin), Markmdver, Mydoeone (Kiihn.^A substance containing sul-
phur and phosphorus, whicn Couerbe obtained by treating the deposit which separates
from the fJcoholio and ethereal extracts of the brain with ether; diolesterin then dis-
solves, and the so-called cerebrote remains. According to Fr^my, it is merely a
mixture of cerebric add with small quantities of cerebrate of potaasium and brain-
albumin.

CBUO AOXB. An acid obtained by treating oerin, the waxy matter of ooik,
with nitric add, washing with water, dissolving in alcohol, filtering and evaporating.
It is a brownish diaphanous waxy mass, which softens at a gentle heat^ and melts
below the boiling point of water. Dissolves readily in alkalis. Yields empyreumatic
products when heated. Contains 64*2 per cent carbon, 8*8 hydrogen, and 27*0 oxygen,
with acetate of lead it forms a white predpitate containing 61*1 C, 6*9 H, 19*2 Pb*0,
and 22*8 0. (Dopping, Ann. Ch. Pharm. xIt. 289.)

cnnunr* A waxy substance extracted by alcohol or ether from grated cork, pre-
viously freed from the outer crust. It separates from the solution in yellowish needles,

CEBINE — CERIITM. 83 1

which maj be obtained oolourlesB by reeiystallisatioii. OontaiiiB 74*95 carbon, 10*55
hydrogen, and 14*5 oxygen, agreeing nearly with the empirical formula C^H^O*.
derin softens in boiling water and faUs to the bottom. It is not attacked by boiling

e^tash. Thrown on glowing coals, it TolatiliseB like beeswax, giying off white f^mes.
y dry distillation it yields a little acid and a huge quantity of an oil which solidifies
on cooling ; it leaves bnt little charcoal Treated with hot nitric acid it yields eerie
acid, together with oxalic and carbonic acids. Cork contains from 1*8 to 2*5 per cent
of waxy matter. (Chevreul, Ann. Chim. xctL 170; Dopping, loe. eit.)

The name cerin was also applied by John to the portion of berawax which is soluble
in alcohol ; bnt according to Brodie, the substance thus designated is merely impure
oerotic add (£. v.)

CMRZn or AX&AJriTB. See Obthitb.

A waxy fat obtained from the lignite of Gkrstewitz near Mersebeig,
of which it forms about 18 per cent Contains 76*7 to 78*1 0, and 11*1 to 12*3 H.
Flastio at common temperatures ; melts at 100^ C. ; sparingly soluble in alcohol ; not
saponifiable ; yields a eEystalline product by distillation. (Wackenroder, Ann. Ch.
Pharm. Ixxii. 815.)

OBBZTSi A h^drated silicate of eerium, containing also lanthanum and didy-
mium. It is the emef source of eerium, and is the mineral from which that metal
was first obtained. It is found only in an abandoned copper mine at Biddarhytta in
Westmanland, Sweden, occurring in compact fine-grained masses of indistinct blackish
red colour; also in short six-sided pnsms. Specific gravity 4*93. Hardness 6'5»
Before the blowpipe it gives off water, but does not melt. It is eom|>letely decomposed
by hydrochloric acid, leaving a residue of silica. According to Kjerulf (Ann. Ch.
Pham. Izxxvii 12) it does not give off a trace of chlorine when treated with hydro-
chloric acid, and consequently the cerium exists in it wholly as oerons oxide. Ejerolf
found it to contain :

SiO» Ce«0 ^1^1 Fe*0 Ca»0 H«0 MoS BiS

20-40 56*07 812 4*77 1*17 5*29 8*27 0*18 - 99-27

whence may be deduced the formula 2MH>.SiO' + aq. or M^SiO^ + aq. It generally also
contains a small quantity of yttria.

OWBXUWMm Symbol Ce. Atomio Weight 46. — ^This metal, which was discovered
in 1803, simultaneously by Klapoth and by Hisinger and Boxelius, exists, together
with lanthanum and didymium, in cerite, almnite, ortiiite, yttro-cerite, and a few other
minerals, all of somewhat rare occurrence. The most abundant of them is cerite {yid,
svp.) To extract the oxides of the three metals, the cerite is finely pounded and
boiled for some hours with strong hydrochloric acid, or aqua-regia» which dissolves the
metallic oxides, leaving nothing but silica. The filtered solution is then treated with
a slight excess of ammonia^ which precipitates everything but the lime ; the precipi*
tate is redissolved in hydrochloric acid, and the solution treated with excess of oxalio
acid. A white or faintiy rose-coloured precipitate is Uien obtained, consisting ci the
oxalates of cerium, lanthanum, and didymium : it is curdy at first, but in a few minutes
becomes crystalUne, and easily settles aown. When dried and ignited, it yields a red-
brown powder, containing the three metals in the state of oxide. The finely pounded
cerite may also be mixed with strong sulphuric add to the consistence of a thick paste,
the mixture gently heated till it is converted into a drv white powder, and this powder
heated somewhat below redness in an earthen crucible. The three metals are thus
brought to the state of baaie sulphates, which dissolve completely when very gradually
added to cold water; and the solution treated with oxalic acid yields a precipitate of
the mixed oxalates, which may be ignited as before.

From the red-brown mixture of the oxides of cerium, lanthanum, and didymium
thus obtained, a pure oxide of cerium may be prepared by either of the following pro-
cesses : — 1. The mixed oxides are heated with strong hydrochloric acid, which dis-
solves the whole, with evolution of chlorine ; the solution is precipitated with excess of
caustic ^tash ; and chlorine oas passed through the liquid with the precipitate sus-
pended in it. The cerium is t£ereby brought to the state of ceroso-ceric oxide, which is
left undissolved in the form of a bright yellow precipitate, while the lanthanum and
^dymium remain in the state of protoxides, and disso^e. To ensure complete separa-
tion, the passage of the chlorine must be continued till the liquid is completely saturated
with it, and the solution, tosether with the raecipitate, left for several hours in a
stoppered bottle, and agitated now and then. The liquid is then filtered, the washed
peeipitate treated with strong boiling hydrochloric acid, which dissolves it with evo-
lution of chlorine, and forms a colourless solution of protochloride of cerium ; and this,
when treated with oxalio acid or oxalate of ammonia, yields a peifecUy white precipitate

832 CERIUM.

of oxalate of cerium, which may be converted into oxide bj ignition (Mosander). —

2. The red-brown mixtare of the three oxides ia treated with yeiy dilute nitric acid
(1 pt of nitric acid of ordinair strength to between 50 and 100 pts. of water), which
dissolves the greater part of the oxi<ik8 of lanthannm and didymium, and leaves the
oxide of cerium ; and by treating the residue with venr strong nitric add, the last
traces of lanthanum and didymium maybe extracted (Mosander, Marignac). —

3. The red-brown mixtare of the three oxides is boiled for several hours in a strong
solution of chloride of ammonium. The oxides of lanthannm and didymium then dis-
solve, with evolution of ammonia, and sesquioxide of cerium is left in a state of purity.
It must be collected on a filter and washed with a solution of sal-ammoniac, because,
when washed with pure water, it first runs through the filter, and then stops it up
(Watts, OheuL Soc. Qu. J. iL 147). — 4. Oxalate of cerium obtained as above is mixed
with half its weight of pure magnesia, and made up into a stiff paste with water ; and
this mixture when dry is heated to low redness in a porcelain basin, with constant
stirring. The product is a cinnamon-coloared powder, containing the whole of the
cerium as eerie (? oeroso-ceric) oxide, in combination with magnesia, oxide of lantha-
num, and other protoxides. It dissolves completely, with aid of heat^ in strong nitric
acid, forming a deep brown solution of a double salt, which appears to consist of oerio
nitrate in combination with cerous nitrate and the nitrates of lanthanum, didymium,
and magnesium, sometimes also a small quantity of nitrate of yttrium. This double
salt separates in splendid rhombohedral crystals having nearly the colour of add
chromate of potassium. The solution, if diluted with water before these crystals
have separated, does not yield any predpitate, either in the cold or in boiling ; but if
the crystallisation be allowed to go on till lighter-eoloured laminated crystals separate
containing magnesium and lanthanum with very little cerium, the mother-liquor then
deposits, on dilution and boiling, a basic salt of cerium free ftom. all other metals.
The predpitate is not formed so long as the red double salt remains dissolved in the
liquid ; indeed it redissolves on addii^ to the liquid a solution of that salt. The liquid
from which the cerium predpitate has separated still retains cerium, which may be
separated by repetition of the treatment.

To separate Uie cerium from the solution of the red salt, it is diluted with a large
quantity of water, then boiled, and sulphuric acid added in small quantity as long as
the resulting precipitate is thereby increased. The cerium is then precipitated as a
yellowish-white, flocculent basic salt, containing both nitric and sulphuric adds, but
free from all other metals, which is difficult to wash on a filter, but is easily washed by
decantation with water slightly acidulated with sulphuric add. This salt dissolves
readily^ in strong sulphuric add, and the solution, after reduction with sulphurous
add, yields, with oxalic add, a white predpitate of pure cerous oxalate.

If it be desired to obtain a basic nitrate of cerium free from sulphuric add, as is often
desirable for other preparations, the red solution of the double nitrate must be evapo-
rated to a syrup, and then poured into a large excess of boUing water slightly addu-
lated with nitric add. The predpitate thereby formed is washed by decantation with
water containing a little nitric acid, and the mother-liquor, together with the wash-
water, is again evaporated to a syrup and treated as before, till nearly all the cerium
is extracted. The addition of nitric add to the wash-water is essential, as the basic
nitrate dissolves somewhat readily in pure water. It is best to preserve the predpi-
tated salt under addulated water, since it becomes insoluble in adds when dried and
ignited. (Bun sen, Ann. Ch. Pharm. cv. 40.)

Metallic cerium is obtained by heating the pure anhydrous protochloride with
potassium or sodium. It is a grey powder, which acquires the metallic lustre by pres-
sure. It oxidises readily, decomposes water slowly at ordinary temperatures, quickly
at the boiling heat, and dissolves rapidly in dilute adds, with evolution of hydrogen,
forming a solution of a cerous salt

Cerium forms three classes of compounds, viz. tho cerous compounds, or proto-^som'
pounds, e. g. the protochloride, CeCl, the protoxide CeK) ; the sesgui-compounds, or
cerio compounds, e.g. Ce'Cl*, andCe^O*, and the ceroso-cerio compounds, which may
be regarded as compounds of the other two ; e, g. ceroso-ceric oxide, Ce*0*= Ce*O.C*0*.

CBRZimCy 8SOBCZDB OV. Kot known in the anhydrous state. A solution of
eerie oxide in hydrobromic add yields by evaporation, small crj^stals of a hydrated
bromide, which gives off hydrobromic add when heated and leaves an oxybromide.

CSRXVBi, CBJMBXDBB 07. Cerium bums vividly when heated in chlorine
eas, and forms the protochloride CeCl. The anhydrous chloride may be prepared by
igniting the sulphide, or the residue obtained by evaporating to dryness a solution of
the chloride mixed with sal-ammoniac, in a current of chlorine gas. If the air is not
completely exduded, an oxychloride is also produced. The aimydrous chloride is a
white porous mass, fusible at a red heat^ and perfectly soluble in water. A h^raied

CEEIUM. 833

chloride is obtained in oolonrless fonr-sided piismB, by dissolving the hjdrated oxide
or the carbonate in hydrochloric acid, and evaporating to a syrap. The solution when
exposed to the air, turns yellow, from formation of a ceroso-ceric salt.

I^tochloride of cerium forms with dichlaride of platinum, an orange-coloured crys-
talline double salt, 2CeOLPtCl'.4H*0, easily soluble in water and alcohol, insoluble.in
ether. It also combines with iodide of einc. (Holzmann, Phil; Mag. [4] xxii. 219.)

Ceroeo-cerio chloride. — Hydrated ceroso-ceric oxide dissolves in cold hydrochloric
acid, £>nning a red solution, which, however, soon gives off chlorine, and is reduced,
more or less completely, to protochloride.

OBRXVBi, lIBnOTZOSr AVB aSTXMATZOXT Or. 1. Reaotione.^
All compounds of cerium, ignited with borax or nucrocosmio salt in the outer blowpipe
flame, yield a glass which is deep red while hot., but becomes colourless on cooling. In
the inner flame, a colourless bead is formed with a small quantity of the cerium com*
pound ; but a yellow enamel with a larger quantity.

Ceroiu salts in solution are colourless, have a sweet astringent taste, and redden
litmus, even when the acid is perfectly saturated. They ar^ distinguished by the fol-
lowing reactions : Stdphydric acid produces no precipitate. Sidphide of ammonium
throws down the hydrated protoxide. Caustic potash or soda produces a white preci-
pitate of the hydrated protoxide, which is insoluble in ex,cefis, and is converted into
the yellow hydrated sesquioxide by the action of chlorine-water or hypocblorous acid*
Ammonia precipitates a basic salt Alkaline carbonates form a white precipitate of
cerous carbonate insoluble in excess. Oxalic acid or oxalate of ammonia produces a
white precipitate of cerous oxalate, gelatinous at flrst., but quickly assuming the crys-
talline character, and converted by ignition in an open vessel into a yellowish-white
powder consisting of ceroso-ceric oxide. Ferrocyanide of potassium produces a white
pulverulent precipitate ; ferricyanide of potassium none. Sulphate of potassium pro-
duces a white crystalline precipitate of potassio-cerous sulphate, nearly insoluble in
pure water, and quite insoluble in excess of sulphate of potassium. With dilute solutions
the precipitate takes some time to form. This character, together with the behaviour
of the oxalate and the vellow coloration of the hydrated protoxide by hypochlorous
acid, serves to distinguish cerium from all other metals.

2. Quantitative Estimation. — Cerium is precipitated from neutral solutions of
cerous salts by carbonate of ammonium, as cerous carbonate, or by oxalate of ammonium
as cerous oxalate ; and either of these compounds is converted by ignition in an open
vessel, into ceroso-ceric oxide, which, according to Bunsen, corresponds, within the
limits of experimental error, to the formula Ce*0', and contains 81 "18 per cent of
metallic cenum, or 95*04 per cent of the protoxide. Another method is to dissolve
the precipitated carbonate in dilute sulphuric acid, evaporate, and heat the residue to
commencing redness, whereby it is converted into the anhydrous sulphate, Ce^O^,
containing 48*95 per cent of the metal, or 57*45 per cent of the protoxide.

3. Separation from other Elemen ts. — Sulphydric acid serves to separate cerium
from all metals which are precipitated by that reagent from their acid solutions. From
manganese, iron, cobalt, nickd, zinc, titanium, chromium, vanadium,, and tungsten,
cerium may be separated by means of a saturated solution of sulphate of potassium.

From aluminium it may be separated by carbonate of barium, which precipitates
alumina and not cerous oxide; from glucinum by sulphate of potassium. From
yttrium, with which it is often associated in minerals, it may be separated by a satu-
rated solution of sulphate of potassium, added in excess, the sulphate of yttrium and
potassium being soluble in excess of sulphate of potassium, while the cerous double
salt remains undissolved. From gireonitim, cerium is separated by treating the boil-
ing acid solution with sulphate of potassium, whereby the greater part of the zirconia
is precipitated as basic sulphate, wnile the cerium remains dissolved ; to complete the
precipitation, a small quantity of ammonia must be added, but not sufficient to satu-
rate the acid (H. Rose). From Tnagnesium also cerium may be separated by sulphate
of potassium ; from barium, strontium, and calcium, it is separated by ammonia added
in slight excess ; or from barium by sulphuric acid, and from strontium and calcium
by smphuric acid and alcohol ; and from the alkali^meials by precipitation with oxalate
of ammonia. Bunsen's method of precipitation already described, affords however the
the best means of separating cerium from all the metals with which it is found as-
sociated, especially from lanthanum, didymiwm, and yttrium^

4. Atomic Weight of Cerium,^~The older statements respecting the atomic
weight of this metaf, all refer to cerium containing lanthanum and didymium. For this
impure metal, Hisinger, in 1814, found the number 45-65 (Hb^I), and Otto found 46-8.
After the method of removing the lanthanum and didymium had been pointed out by
Hosander, Beringer (Ann. Ch. Pharm. liL 134), irom the analysis of the proto*

Vol. I. 8 H

834 CERIUM: FLUORIDES — OXIDES.

ehloride CeCl, deduced the itnmber 47*8, and from that of the sidphate the number
46*2.

Herm a nn, from an analysis of eeroos sulphate, in whidi the sulphuric acid was pore-
dpitated as sulphate of barinm, found for cerium the numher 46.

Marignae (Ann. Ch. Phaim. Ixriii 216), hj precipitating eetoiis snlphafte with s
graduated scdntion of chloride of barium, obtained, as a mean of seren comeriments^
Ce -> 47*26. Afterwards, howcTer (Ann. Ch. Phjs. [3] zxxriiL 148), he re|ected this
number, and adopted that pteriously found by Hermann, Tis. 46, attributing the excess
of his former determination to the circumstance, that a portion of the eeroos sulphate
had been carried down undecomposed by the barium precipitate, whence the q[ttantitj
of ddoride of barium required to precipitate the sulphate came out too low.

Lastly, Buns en has determined the atomic weight of cerium by the analysis of the
sulphate. Pure basic eerie sulphate, obtained as abore described (pu 832), was diBSolred
in sulphuric acid, reduced to oerous sulphate by sufehurous add, the salt evaporated and
Ignited till all the excess of add was expelled, ana the residue twice oystallised from
water. A solution of this salt was pved^itated by oxalic add ; the precipitated oxalate
eonrerted into ceroso-oeric oxide by ignition ia an open Teasel ; and ihe sulf^uric add
pedpttated from the filtrate by chloride of barium. The eeroso-ceric oxide was then
heated in a sealed flask containing Tery little air, with pore hydrochloric add and
iodide of potassium, whereby it was reduced to eeroos oxide, and a quantity of iodine
set free equivalent to the oxygen separated from the ceroso-ceric oxide. This free
iodine was estimated by Bonsen*8 Tolumetric method (Analysis^ Volvmbtbic^ p. 266%

and the coixesponding amount of oxygen estimated by the fonniila s b- >— a (nl— #7-

In this manner, 100 pts. of the eezoso-ceric oxide were found to contain 95*04 ccrous
oxide and 4*96 oxygen. From this, the quantity of cerous oxide in the ignited ceR»o>
eerie oxide (that is to say, in the original <|uantity of oerous sulphate), was calculated,
and the amount of sulphuric add (SO*) being likewise found from the predpitated sul-
phate of barium, the composition of the cerous sulphate was found to De 57*49 CeH>-i-
42*51 SO* a 100, whence the atomic weight of oerous oxide was found ^!omthqpit>-
portion 42-51 : 57*49 » 80 : x, giring CeK) » 1081, and thoefore Ge » 46*1. Two
other eiq>eriments gare Ce <=r 46*02 and 46*05.

In accordance with the preceding results^ the whole number 46 is genendly adopted
as the true atomic weight of cerium.

OSKXUatv VSiVOXIBBS OV« The protoflnoride CeF, is obtained as a white
predpitate, by adding an alkaline fluoride to a cerous salt It is but partially reduced
by the action of hydrogen gas and potassium rapour at a red heat. (Hosander.)

The sesquiftuonde, CeTF*, prepared in like manner, is a yellow predpitate. It also
occurs native as fltiocerite, in brick-red or nearly yeUow six-sided prisms and plates,
with Tery distinct basal deavage ; also massive ; specific gravity 4*7. Hardness 4*5.
It gives off fluorine when strongly heated in a glass tube. It occurs at Finbo and
!ftoddbo, near Fahlun, in Sweden. Sesquifluoride of cerium also occurs with the
fluorides of caldum and yttrium, as pttrocerite (q. v.)

A hydrated eerie oxyfittoridey C^F*0* + 3H*0, occurs at Finbo as ft%ioeerinA, in
yellow crystals with vitreous lustre, supposed to belong to the regular system (Gm. iiL
271). A mineral from Bastnas in Sweden, analysed bv Hisinger, yielded numbers
corresponding to the formula Ce^FH)' + 4H*0 ; one from^nbo, analysed by Berzelius^
was found to consist of Ce»*FK)» + 8HK), or 2C5e^.3(CeK)«.H«0). (Dana, ii 96.)

onutmiB, oaUBSS of. The Trotoxide, or Cerous oxide, CeK), is obtained
by heating the carbonate or oxalate in a current of dry hydrogen perfectly free from air.
It is a greyish-blue powder, which on exposure to the air quickly becomes very hot»
and is converted into yellowish-white ceroso-ceric oxide. Cerous hydrate predpitated
from the solution of a cerous salt by a caustic alkali, is white, but when exposed to
the air, quidkly changes to a yellow mixture of cerous carbonate and eeroso-ceric hy-
drate (Kamm els berg, Po^ Ann. cviii. 40). The hydrate dissolves readily m
sulphuric, nitric, hydrochloric, and acetic add, the solutions giving the characters
described at p. 833.

Ceroso^eric Oxide^ Ce*0*. — ^This oxide, which may be regarded as a compound
of cerous and eerie oxide : 2Ce*0«=Ce*0.Cc*0*, is produced when cerous hydrate, car-
bonate, oxalate, or nitrate, is ignited in an open vessel. It is yellowish-white, acquires
a deep orange-red colour when heated, but recovers its original tint on cooling (B u n s e n.
Ram me Is berg). Ignited in hydrogen gas, it assumes an olive-green colour, but
does not diminish perceptibly in weight (Bun sen). It is not raised to a higher state
of oxidation by heating in oxygen gas, or even by fiision with chlorate or hydrate of
potassium (Ramm e Isberg). Nitric and hydrochloric acid have but little action upon
it, even at the boiling heat> unless it be mixed with the oxides of lanthanum and didy-

CERIUM: OXYGEN SALTS — SULPHIDES. 885

mium, in which case it diflsolves readily in hot hydrochloric add, with evolution of
chlorina Heated with a miztnre of iodide of potassium and hydrochloric acid, it
dissolves completely, with separation of iodine, — a property which has been made
available by Bnnsen for determming its composition. Strong sulphuric acid at the boil-
ing heat, converts it into an orange-red s&lt^ which becomes light ydlow on cooling,
and dissolves with yellow colour in water.

Maiignac did not obtain ceroso-ceric oxide of constant composition, but supposed it
to have^for the most part,the composition 3Ce*0.2Ce^O*, or Ce**0'. RammelBberg, by
decomposing the ceroso-ceric sulphate, 3Ce*S0^Ge*(S0*)' with potash, obtained a
reddish-grey precipitate which contained dCeK>.Ce^O', but was quickly converted into
Ce'O', on exposure to the air.

Ceroso-cerio Hydrate^ 2Ce^O*.3H'0, obtained bypassing chlorine into aqueous potash
in which oerous hydrate is suspended ^p. 831), is a oright yellow precipitate, which dis-
solves readily in sulphuric and nitnc acid, forming yeUow solutions of coroso-ceric
salts; in hydrochloric acid, with evolution of chlorine^ forming colourless cerous
chloride.

Cerie Oxide^ Ce^O', does not appear to exist in the free state, inasmuch as ceroso-
ceric oxide is not brought to a higher state of oxidation, even by ignition with power-
ful oxidising agents {vid. sup.)

CSRXVBi, OXT<Unr«aAliT8 OV« The eerous salts are produced by dissolv-
ing cerous oxide or carbonate in acids, also by the action of sulphurous acid and other
reducing agents on eerie or ceroso-ceric salts. (For their properties and reactions
see p. 833.) Cerous silicate exists in nature as Cerite ; the phosphate as Monazite,
ErdwardsiUy CryptoUte^ and PhosphoceriU : the carbonate, together with fluoride of
calcium, in Parisite,

Cerous salphate forms sparingly soluble double salts with the sulphates of ammo-
nium, potassium, and sodium. Tlie potassium-salt, KCeSO\ is the least soluble in
water, and quite insoluble in solution of sulphate of potassium.

The ceros(heeric s&lts are obtained by dissolving the corresponding oxide or hy-
drate in adds. The solution of the sulphate yields by spontaneous evaporation, first
brown-red crystals, composed of 3Ce'S0\Ce^^S0*)*-f 18aq., and afterwards a yellow,
indistinctly crystalline salt> containing Ce*SO^Ce*(SO*)' + 8 aq. By substituting
cericwmf oe a 30} for cerosttm, Ce « 46, in the sesquisulphate, these formulse may l^

reduced to >. LI ^ "*" ®*^**^^ Ce.<jJ* ( ^* "*" **^'* 'fi^^^^'^c^y- ^*^ ■*^** ■'® ^®"

composed by water, with separation of a basic salti containing 6Ce'0^3(p [0*j

+ 12 aq., but dissolve on addition of sulphuric or nitric acid. The solution of either
salt yields, with sulphate of potassium, a mixture of at least two double salts, in which
potassium and cerosum may be regarded as replacing one another isomorphously :
similarly with sulphate of ammonium : the ammonium double salts, when ignited, leave
pure eeroso-ceric oxide.

The rhombohedral nitrate of cerium and magnesium obtained by Bunsen (v. 832),
is, when purified, a ceroso-cerioo-magnesic salt^ containing HgKle(KO')'.(Ce') (NO*)'

+ 8aq., or TLj^n ce"! ^' "*" ® *^' ^^ originally obtained, it contains lanthanum and

didymium, replacing cerium isomorphously.] Double salts of similar composition are
obtained by mixing a solution of this nitrate with the nitrates of potassium and zinc ;

with nitrate of nickel, a basic salt containing N^Oe^J^j 0*-NiHO + 12H*0. (Hols-
man n, J. pr. Chem. Ixxv. 321.)

The existence of pure cerio salts is by no means certain. Bunsen speaks of a basic
eerie sulphate, precipitated by boiling Uie solution of the magnesian ceroso-ceric salt
just mentioned, with sulphuric acid ; but he has not given an analvsis of it : indeed,
no analysis of a pure eerie salt has yet been published. The so-called basic eerie sul-
phate just mentioned, yields, bydigestion with caustic potash, not coric, but ceroso-
ceric hydrate (Holzmann). [For further details respecting the oxygen-salts of
cerium, see the several acids.]

CWKXUMf FB08FBZBB OV« Said to be obtained, together with phosphate,
by passing phosphoretted hydrogen over whit«-hot ceroso-ceric oxide. (Mosander.)

CBBIUlCf BWnUMimkM OV. Produced by decomposing cerous selenit^ with
hydrogen at a red heat. It is a brownish powder, which dissolves in acids, with evo-
lution of selenhydric acid. Cerous salts give with alkaline selenides a pale red preci-
pitate, probably consisting of hydrated setenide of cerium.

OBBZVM, SUUrBZSBB OV. Cerous sulphide, Ce% is obtained by igniting the
earbonate in vapour of sulphide of carbon, or by heating an oxide of cerium with sul-

3h 2

836 CEROLEIN — CEROTIC ACID.

phide of potafiaium. The firflt process yields a light powder of the oolonr of red lead ;
the second, a prodact resembling mosaic gold (Mosander). Ceric sulphide is not
known in the free state, bnt is said to combine with other metallic solphides.

CBROUBIW. A snbstance obtained from beeswax (in which it is said to exist
to the amount of 4 or 6 per cent.) by treating the wax with boiling alcohol, leaving the
cerotic acid to d posit on cooling, and eyaporating the filtered solution. It is yeij
soft, melts a 28*6° C, dissoWes readily in cold alcohol and ether ; is acid to litmus ;
giTesby analysis 7874 per cent C, 12-61 H, and 8*75 O (Lewy, Ann. Ch. Phys. [3]
yiii 438). It is probably a mixture.

GBKO&ZTX or XBSO&ITB {frGm Kifpos wax, and \t0os stone). — This name is
applied to two or three minerals or mixtures, consisting chiefly of hydrated silicate of
magnesium more or less mixed with silicate of aluminium. They are all massiye,
reniform, compact or lamellar, transparent or translucent, white or grey, with Titneona
or resinous lustre, and greasy to the touch.

Analys€8. — a. From Frankenstein in Silesia hj Kuhn ; h. from an unknown localilj
by Delesse ; c. from Zoblitz in Saxony by Melling:

SiO« A1*0» Mg*0 FeH) H«0

a . 46-96 -^ 81 26 ~ 21*22 « 9944

b . . 63-6 0-9 28-6 — 164 » 99*4

e . . 47*13 2-67 3613 2*92 11*60 - 10026

The first agrees nearly with tlLs formula Mg^SiO^ + 3aq. {Rammdtber^8 Mineral'
chemiit p. 862.)

cnuUIPIC MkXni^m An acid obtained by Kawalier (Ann. Gh. Pharm. Ixxxviii. 3601
from the needles of the Scotch fir {Piniu sylvestris). The needles are boiled with alcohol
of 40 per cent, the alcohol is distilled o£^ and the residue is mixed with water, whereby
it is separated into a yellowish resin and a somewhat turbid liquid. The resinous
mass is redissoWed in alcohol of 40 per cent, the solution precipitated with acetate of
lead, and the precipitate suspended in aleohol is decomposed by sulphuretted hydrogen.
The solution filtered hot deposits ceropic acid in yellowish-white fiocks, which, hv
boiling with alcohol and animal charcoal and repeiU^ aystallisation from alcohol
may be obtained in white, friable, microscopic crystals, melting at 100° C, and solidify-
ing in a waj^ mass. The ciystAls dried in vacuo gave by analysis 74*24 per cent
carbon and 12-17 hydrogen, whence Kawalier deduces the improbable formula
CP*H**0^. The barium-sidt gave 66-60 carbon, 10-33 hydrogen, 12-66 oiygen, and
11-52 bazyta, represented by the formula BaO.C^IP*0*.

CBKOBZC ACZ]>. G^H^O'. — Obtained by heating cerosin (sugar-cane wax)
with potash-lime, and purified by saponifying with baryta, dissolving the soap in
alcoh(u, decomposing it with hydrochloric acid, and dissolving the precipitate in rock-
oil, whence it crystallises on cooling. It melts at 93°C. ; dissolves sparingly in boiling
alcohol and ether. (Lewy, Ann. Ch. Phys. [3] xiiL 438.)

CBB08ZW. Cerotie. — The wax of the sugar-cane, obtained by raspm^ the bark
of the cane, especially of the violet variety, and purified by recrystallismg several
times from boiling alcohol. It then forms delicate white nacreous laming, which do
not stain paper. Gives by analysis 81*0 to 81*7 G and 13*6 to 14*2 H, agreeing nearly
with the formula G'H^O', whidi represents it as a kind of aldehyde or ether. It
melts at 82° G., is insoluble in cold ether and alcohol, very soluble in boiling alcohol.
It is very hard and easily pulverised. (A vequin, Ann. GL Phys. Ixxv. 218 ; Dum as,
ibid, Ixxv. 222 ; Lewy, loc. cit)

CBSOTBira. C'H^. — A hydrocarbon homologous with ethylene, first obtained
by Brodie (PhiL Mag. [Z] xxxiii 378 ; Ann. Gh. Pharm. IxviL 199) as a product of
the dry distillation of Ghinese wax. The distillate consists of two parts, cerotic acid
passing over first, and afterwards oerotene mixed with a certain quantity of oily matter,
which may be romoved by pressure. It is purified by crystallisation, first fix>m a mix-
ture of alcohol and naphtha, then fr^m ether. It is crystalline, melts between 67°
and 68° G., and exhibits the characters of the substances which have been confounded
under the name of Paraffin (q. v.) When distilled several times, it is completely trans-
formed into a mixture of liquid hydrocarbons, whose boiling points vaiT from 76° to
260° G.

Chlorinated derivatives of Cerotene. — When moist chlorine is passed over melted
cerotene, the latter assumes a waxy aspect, then becomes gummy, and is ultimately
converted into a transparent resin, becoming harder as it abrorbs mora chlorine. The
reaction takes several weeks to complete, lind at different stages of it the following
compounds are formed : — G''H"G1»» ; G"H"G1« ; GlhH*«Gl« (Brodie.)

CamOTZC ACZB. G«'H"0« - G"H"O.H.O. Cerin of Beeswax. (John, Ch^
tnische Schriften, iv. 38; Boudet and Boissenot, J. Pharm. xiii 38; Ettling^ Ann.

CEROTIC ETHERS — CERUMEN. 837

Gh. Pharm. u. 267 ; Hess, ibid, zxrii 3 ; Gerhardt^ Bev. scient. xix. 5 ; Lewy, Ann.
Gh. Fhys. [3] xiii. 438; Brodie, Ann. Gh. Pharm. Ixvii. 180.) — This acid is the essen-
tial constituent of that portion of beeswax which is soluble in boiling alcohol. It
is prepared by treating beeswax several times in succession with boiling alcohol,
till the deposit which forms on cooling melts at 70^ or 72^ G. The acid thus obtained
is not yet pure. It is, therefore, to be dissolved in a large quantity of boiling alcohol
and the solation precipitated by acetate of lead. The precipitate, after being ex-
hausted with the aid of heat by alcohol and ether, is decomposed by concentrated
acetic acid, and the product ciystaUised from alcohol yields pore eerotic add. Gerotic
acid may also be obtained very nearly pure by crystallising several times from ether,
the crude product which melts at 72° G. The mother-liquors retain a small quantity
of another fatty acid. — Gerotic acid is likewise produced by the dry distillation of
Ghinese wax, and by melting that substance with potash.

Pure eerotic acid crystaUiseB on cooling from its solutions in small grains, melting
at 78° G. The melted mass assumes on cooUng a highly crystalline chimicter.

The pure acid distils without alteration, but the impure acid is decomposed by diff'
filiation, yielding principally oily hydrocarbons of very variable boiling point, and
containing in solution small quantities of a fatty acid and other oxygenised products.
Ghlorine transforms eerotic acid into chloroceroHc acid, G'^H^'GP'O'.

Cerotates, — Gerotic acid is monobasic, the formula of its neutral salts being
G«*H"M.O«. The lead-salt, G"H"PbO«, is obtained as a white bulky precipitate on
mixing a solution of eerotic acid in boiling alcohol with alcoholic acetate of lead. The
mlversalt, G^H**AgO*, is obtained bv precipitating an alcoholic and ammoniacal solu-
tion of eerotic acid with nitrate of silver at the boiling heat.

Ghlosocebotto Acm. G^'H^GPK)*. — ^Produced by exposing melted eerotic acid to
the action of chlorine for several da^'as long indeed as ftimes of hvdrochloric acid
are perceptible. The product is a thick transparent gum of a pale yellow colour.

(Morocerotaie of soaiwn is nearlv insoluble in water.

ChlorocerotaU of ethyl, G»H«a»k)«-C^H*'Gl'«0«.G*H», is prepared similarly to the
cerotate. It has the aspect of chlorocerotie acid.

OBROTZO BTB2R8. Cerotate of ethyl, G»H^» = G»^»0«.C»H», is
easily produced by passing hydrochloric acid gas into solution of eerotic acid in abso-
lute alcohoL It has the aspect of beeswax, and melts at 59° — 60° G.

Cerotate of Ceryl Chinese Wax. G~ff*0« - ^|^"^ | O. — This is a pecu-
liar waxy substance obtained from Ghina, where it is produced on certain trees by
the puncture of a species of coccus. It is crystalline, and of a dazzling whiteness, like
spermaceti, but more brittle and of a more fibrous texture. It melts at 82° G. It is
purified by crystallisation from a mixture of alcohol and naphtha, then washed with
ether, treated with boiling water, and recrystalHsed from absolute alcohol, which dis-
solves it in small quantity only. Ghinese wax is not saponified completely by boiling
with aqueous potash, but decomposes readily when fhsed with potash, yieldm^ cero-
tate of potassium and hydrate of ceryl. By dry distillation it yields eerotic acid and
cerotene. Almost all the wax gathered in Ghina is used there for making candles. It
is also employed by the Ghinese as a medicine.

£t^. of Gbrtuo Aixsouol or Htd]ia.tb of Gebtl (p. 838).

IV* The acetone of eerotic acid, obtained by careful distiUation of
cerotate of lead. (Bruckner) J. pr. Ghem. IviL 1.)

OBKOZTXXV or Palm wax is the produce of the Ceroxylon Andicola, and is ob-
tained by rasping the epidermis of the tree and boiling the raspings in water. The
wax floats on the surface in a soft state, while the impurities sink to the bottom. It
may be further purified by repeated boiling with alcohoL In its natural state it is a
greyish-white powder ; after purification, yellowish-white. It is nearly insoluble in
alcohol, and melts at 72° G. It has been analysed byBoussingault (Ann. Gh. Phys.
xxix 833), Lewy (Ann. Gh. Phys. [3] xiii« 468), and Teschemscher (Ann. Gh.
Pharm. Ix. 270) with the following results: — .

Botusingtolt. Letry. Tetchemaeher.

Garbon .... 80*48 8073 80-29

Hydrogen . . . 13*29 13-30 18*29

OxygeB .... 6*23 5*97 6*42

10000 10000 100*00

CMKUWOOK OV TBS ItAM* A yellow secretion which lines the external audi-
tory canal, rendered viscid and concrete by exposure to air. It has a bitter taste,

3u 3

838 CERUSE — CETIN.

melts at a low hent, and evolveB a aliglitly aromatic odour. On ignited coals it
gives oat a white smoke, similar to that of burning fat^ swells, emits a fetid ammo-
niacal odonr, and is conyerted into a light charcoal Alcohol dissolres | of it; and on
eyaporation leaves a substance resembluig the resin of bile. The { which remain are
albnmin mixed with oil, which by incineration leave carbonate of sodinm and phos-
phate of caldnm. 17.

CBRirsa or White lead. See Casbonatbs (p. 786).

Native carbonate of lead (p. 786).

Native tetroxide of antimony, SbO* or SbK)*.Sb*(>*, found at
Cervantes in Spain and at Pereta in Tuscany (p. 324).

CBSTXi* STBRATB OV. CeryUc Alcohol, Carotin. CP]F*0»^^*^|o.—

Produced by fusing Chinese wax (cerotate of ceryl) with potash, digesting the fused
mass in boiling water, whereby a solution of cerotate of potassium is obtained holding
cerylic alcohol in suspension ; precipitating the cerotic acid with chloride of barium ;
and dissolving out the hydrate of ceiyl with alcohol, ether, or coal-tar oil The hy-
drate of ceiyl, purified by several crystaUisations from ether or alcohol, forms a waxy
substance melting at 97° 0. Heated with potash-lime^ it gives off hydrogen, and ia
converted into cerotate of potassium :

C«^'»0 + KHO = C»^»KO« + 4H.

At a veiy high temperature it distfls partly undecompoeed, partly resolved into water
and cerotene, C*^*^ + HK). Chlorine acts upon hydrate of ceryl, producing a trans-
parent pale-yellow substitution-product, ehlorcerotidt containing 37'62 to 37'89 C,
4*76 to 4*78 H, and 55'11 to 65*07 CI, numbers which correspond to the formula
C"'B.**^CI^*^0, The action of the chlorine was probably not complete. The product
has the appearance of a gum-resin, and becomes electrical by friction. (Brodie, Ann.
Ch. Phamu IxviL 120.)

Hydrate of ceryl treated with excess of sulphuric yields a product which, when
washed with cold water, dried in vacuo, and crystallised from ether, has the composi-
tion of neutral sulphate of ceryl with 1 ai. water^ (C"H**)'SO* + H*0. When pure it is
perfectly soluble in water, especially if a little alcohol is added ; the solution evaporated
at a low temperature leaves the substance in the form of a soft wax. (Brodie.)

CSTBWa or Cetylene, C^'H**. (Dumas and P^ligot, Ann. Ch. Phys. [21 Ixii 4 ;
Smith, ibid. [3] vi. 40.) — ^A hydrocarbon homologous with ethylene, obtained by dis-
tilling cetyUc alcohol with phosphoric anhydride, also by distilling cetin (palmitate of
cetylX and treating the product with potash to saponify the &tty adds which have paued
over in the distillation, the cetene then floating on the sur&ce of the liquid.

Cetene is a colourless oily liquid, which stains paper. It boils at 275° C, distilling
without alteration. Vapour-density 8*007. It \b insoluble in water, easily soluble in
alcohol and ether, neutral to test-paper. It has no particular taste. When set on fire^
it bums with a very pure white 'flame, like the &t oils.

Cetene unites with hydrobromic and hydrochloric acids, slowly at ordinary tempera-
tures, somewhat more quickly at 100° C. The compound is decomposed by distillation.
(Berthelot, Ann. Ch. Phys. [3] li. 81.)

The ethylosulphates (sulphovinates) yield by drv distillation an oily liquid {heatfu
oil of wine), from which water separates an oily hydrocarbon (Ji^hi oil of wine), which
boils at nearly the same temperature as cetene ; and this oil, when exposed to a very
low temperature deposits crystals {camphor or stearoptcne of win&<nl), having the same
composition.

CVTXC ACZB. C"H*0* ? — ^Produced, according to Heintz, in very small quan-
tity in the saponification of spermaceti (p. 840). CrystaUises in nacreous scales
grouped in stars, melting at 53*6° C. Benic add obtained from oil of ben, and stillis-
tearic add, from the fruit of BttUinffia eebifera, have the same composition.

CBTIVt C«H"0« (Chevreul, Becherchea sur lei Corps ffras^j, 171 ; Smith,
Ann. Ch. Pharm. xlii. 247; Stenhouse, J. pr. Chem. xxvii. 263; Badcliff, Ann.
Ch. Phys. [31 vi. 60.) — ^A fatty crystalline substance constituting the essential part of
spermaceti, the substance which, m the state of solution in an oil, fills the cavities in
the head of the cacholot, or spermaceti whale, and other cetaceous animals. To obtain
it in a state of purity, spermaceti is treated with cold alcohol, which removes the oil,
and the residue is crystallised frY)m boiling alcohol.

Cetin melts at 49° C, and solidifies on cooling in a translucent mass, which serves
for the maoufacture of candles. Heated to 360° out of contact with the air, it vola-
tilises without alteration ; but if heated quickly and in considerable quantities, it is
completely decomposed into a solid fatty acid (palmitic add), and a liquid hydrocarbon

CETRARIA — CETRARIC ACID. 839

(oetene), accompanied, chiefljr towards the end of the distillation, by secondaiy pio-
aucts, snch as water, carbonic anhydride, carbonic oxide, and defiant gas. Cetin is
insoluble in water. 100 pts. of alcohol of 0'821 dissolTC 2'6 pts. of it; absolute alcohol
and ether dissolye it in larger quantities, and deposit it on cooling in brilliant laminsB.
Nitric acid attacks it slowly, and converts it into a mixture of oonanthylic, adipic, and
pimelio acids.

Cetin boiled with caqstic alkalis is transformed into hydrato of cetyl and a palmi-
tato of the alkali-metal (Smith) :

C«H«K)« + KHO - C»«H"0 + C»«H"KO«,

Hydrate of Faliniute of
cetyl. potMtium.

It must be obsenred, howeyer, that the statements of different chemists regarding the
fatty acids resulting from the saponification of cetin do not quit« agree. Cheyreol
obtained margaric and oleic add. Heints (Pogg. Ann. bcxxiv. 232) obtained a mix-
ture of stearic, palmitic, myristic, codnic, and cetic adds, which he separated by the
different solubibty of the acids themselves, and of their barium-salts, in alcohol. He
therefore regards cetin, not as a simple proximate principle, but as a mixture of the
cctyl-salts of the acids just mentioned. By repeatedly crystallising spermaceti from
ether, he obtained at last a small quantity of a fatty substance, which melted at
53*6® C, but in other respects exhibited the characteiB of cetin, and also its composi-
tion, yiz. 8003 C, 13-25 H, and 6*72 0.

See LiCHBNS.

A.CZB. Cetrarin, C^ffW. (Berzelius, Schw. J. yii. 317;
Ann. Chim. xc. 277. — ^Herberger, Ann. Ch. Fharm. xxi. 137. — KnopandSchneder-
mann, ibid. ly. 144.) — Contained, together with lichenosteario acid, in Iceland moss
{Cetraria isfandica). To obtain the two adds, the lichen is treated for about a quarter
of an hour with a boiling mixture of strong alcohol and carbonate of potasdum (15 grm.
of the carbonate to each kilogramme of alcohol), whereby the acids are dissolyed
as potassium-salts. The filtered liquid mixed with hydrochloric add, depodts the two
ados mixed with a green substance ; and by treating this mixture with 8 or 10 times
its weight of boiling dilute alcohol, the lichenoetearic add is dissolved, while the
cetraric add and the green substance remain undissolved.

To isolate the cetraric add, which forms the greater part of the reddue, this residue
is washed several times with a mixture of ether and an essential oil, for the purpose
of removing the green matter ; it is then boiled with stionff alcohol, which dissolves
the cetraric add, and on cooling deposits it in slender needles, which are purified by
boiling them with animal charcoal, then dissolving them in potash, and decomposing
the potassium-salt with hydrochloric add. (K n op and S ch n ed er m a n n.)

Cetraric add crystallises in extremely fine capilhuy needles, of dazzling whiteness.
It has a pure bitter taste, is nearly insoluble in water, sparingly soluble in ether, vezy
soluble in boiling alcohoL The crystals are anhydrous.

Cetraric acid turns brown when boiled with water ; the alcoholic solution also turns
brown on boiling: this change is much accelerated by the presence of an alkali.
Suiphuric acid colours cetraric add, first yellow, afterwards led : the mass becomes
elntinous and dissolves : and water added to the solution throws down ulmic acid.
Hydrochloric acid dissolves a small quantity of cetraric add, the undissolved portion
assuming a deep blue colour. This blue compound is dissolved with red colour by
strong sulphuric add, and repredpiteted blue by water. This blue predpitate dissolves
in a mixtuxe of du:hloride and tetrachloride of tin, and alkalis aaded to the solution
throw down a blue lake (Herberger). Cetraric acid is oxidised by nitric acid,
yielding oxalic add and a yellow redn. Chlorine and bromine do not appear to act
upon it.

Cetraric acid decomposes carbonates, and ibrms yellow salts, soluble in water and
alcohol, and havinff an intolerably bitter taste. It has a great tendency to form acid
salts. The neutral salte cannot be evaporated, even in vacuo, without decomposing
and turning brown. The add salts are precipiteted in a gelatinous form, by mixing
the neutral salts with half the quantity of hviuochloric add necessary to saturate the
base. They are difficult to wash, but may be evaporated in the air without turning
brown.

An alcoholic solution of add cetrarate of potasdum, forms a deep red precipitate
nith ferric chloride, the liquid at the same time assuming a blood-rea colour.

Cetrarate of ammonium is obtained as a yellow powder, by treating the acid with
gaseous ammonia, of which it absorbs 10'2 per cent. The lead-BsM^ C^'H^Fb^O*, is
obtained as a yellow floccnlent predpitate, by mixing acetete of lead with cetrarate of
ammonium. The tUver-Bs^t is a yellow predpitete, which rapidly turns bzown.
(Knop and Schncdermann.)

8h 4

840

CETTL: ACETATE — CYANIDK

C"H". — ^A moDOtomic akohol-radide not yet isolated, bnt supposed to
exist in a series of compounds homologous with the ethyl-eempousds^ and derived from
gpermacetL The cetyl-compounds at present known are :

TJipeHAO.

Hydrate of cetyl (cetylic alcohol)
Oxide of cetyl (cetylic ether) •
Oxide of cetyl and sodium
Oxide of cetyl and ethyl .
Oxide of cetyl and an^l .
Acetate of cetyl ...
Benzoate of cetyl
Sulyrate of cetyl • . •
Stearate of cetyl
Succinate of cetyl .
Sulphate of cetyl and hydrogen
Sulph^drate of cetyl
Sulphide of cetyl
Cetyl-zonthic acid •

C«H"^0

(C««H")K>

C»«H".Na.O

C'«H«(?H»0

C»'H»C»H".0

C*H«0.C»«H».0

eH^0.C*EP«.0

C»H«0.C'«H".0

(C*HH)»)''.(C»«H")*.0*

(SO«)''.C"H».H.O*

C»«H»HJ3

(C"H")«S

(CO)''.C'«H«JBLS»

T^BSs

Bromide of cetyl
Chloride of cetyl
Iodide of cetyl .
Cyanide of cetyl

C'*H*Br

C»«H"C1

C»«H"I

C»«H«Cy

2>p«NH*.

Nitride of cetyl, or trioetyl- )
amine . . • •)

Cetylphenylamine

Dicetylphenylamine

N.(C>«H»)"

(C»H»
N<C«H»
i H

(C»
N^C'«H'
(C^»

LTB OF. C"H«^* = C*H»0,C»«H".0, is produced by treating
cetylic alcohol with acetic and hydrochloric or sulphuric acid, precipitating by water,
dissolving in ether, and evaporating, as an oily liquid, which at a low-temperature soli-
difies, after awhile, in a mass of needle-shaped crystsils, fbsible at 18*5^ C. (Becker,
Ann. Ch. PharaL ciL 219.)

CVm, BSVSOATB OV. C*'H^< - CHHD.O^'H^.O.— Obtained by heating
chloride of benzoyl with cetylic alcohol in equivalent proportion, dissolving the residua
in ether, and precipitating with alcohol. It forms crystalline scales, which melt at 30^ C^
dissolve readily in ether, and sparingly in alcohoL (Becker, Ice. cit.)

CXTTXh BSOBKZBB of. C'H'^Br. — ^Produced by the action of bromine and
phosphorus on cetylic alcohoL It is a colourless solid body, heavier than water in the
melted state, insoluble in water, veir soluble in alcohol and ether ; melts at 16° C.
When distilled, it gives off hy drobromic acid. (P r i d a u, Ann. Ch. Phann. Ixxxiii. 15.)

CWm^ smrrSATB or. C»H^O««C*H'O.C"H»0. — Obtained by slowly
heating a mixture of cetylic alcohol and butyric add to 200^ C, and proceeding as
with the b^izoate. It is white, neutral, miscible with ether but not with alcohol,
melts more easily than cetylic alcohol, and when cautiously heated in small quantity,
volatilises without decomposition. (Handw. d. Chem. 2** Aufl. iL [2] 929.)

CBT¥X, ClfTiOmrPB OF. C>*H'>CL HydrocUoraU of C^^en^.— -Obtained by
the action of pentachloride of phosphorus on cetylic aloohoL The two bodies mixed
in fragments in a retort, become heated, melt, and act violently on each other, giving
off large^ quantities of hydrochloric add. On subsequently distilling the product*
oxychloride of phosphorus passes over, and then chloride of cetyl, which may be
purified by redistillation with a small quantity of pentachloride of phosphorus, wash-
ing with boilin^r water, and dzying in vacuo at about 120^ C. If it still contains
hydrochloric acid, it must be distilled with lime leoently ignited. (Dumas and
P^ligot, Ann. Ch. Phy& baii. 4.)

Chloride of cetyl is a limpid oily liquid of specific gravity 0*8412 at 12° C, insoluble
in water and in alcohol, but soluble in ether, whence it may be predpitated by weak
alcohol. It distils above 20<P C, with partial decomposition, and by prolonged ebul-
lition the whole of the chlorine may be expelled as hydrochloric add, leaving cetene
(p. 838). It is not acted upon by nitric acid, but strong sulphuric acid decomposes it,
eliminating hydrochloric acid and forming cetyl-sulphuric add. It does not absorb
ammonia. (Tiitscheff, Bep. Chim. pure, iL 463.)

CBTT&v CTAWZBB OF. C''H''.CN. — Obtained in an impure state, 1^ heating
cetylsulphate of potassium with cyanide of potassium, and extracting with etfaet

CETYL: HYDRATE — IODIDE. 841

(Kdhler, Zeitschr. d. gesammt. Natorw. -ni 252; Jahresber. 1856, 579. — Heintz,
Pogg. Ann. ciL 257 ; Jahresber. 1857, 445). According to Kohler, it is a solid crys-
talline snbstance, melting at 53^ C, easily soluble in ether and in hot alcohol ; accord-
ing to Heintz, it is liquid at ordinary temperatures, but its formation is accompanied
by that of a czystalline solid, which melts at 55' 1®, and is probably a mixture of
cetylic ether wiUi palmitic aldehyde. Heated with potash it appears to yield margaric
add, C"H«0». (Kohler.)

cmVTM^ Bra&ATB or. C*«H>«0 » C'«H".H.O. Cetylic ^ Alcohol, Ethal.
(CheTreul, Rechcrchea sv/r lea Corps gras, p. 171. — ^Dumas and P^ligot, Ann. Ch.
Phys. [2] bdi, 4 ; Smith, ibid, [3] vi 40 ; also, Ann. Ch. Pharm. xlii. 247.— Heintz,
Pogg. Ann. Irmriv, 232 ; Ixzxvii. 553.) — This compound is prepared by saponifying
spermaceti with an alkali, the eetin, or palmitate of cetyl contained in that substance
being then resolved into an alkaline palmitate and hydrate of cetyl, which latter is
dissolved out by alcohol or ether. Dumas and P^ligot add 1 pt. of solid hydrate of
potassium, by small portions and with constant agitation, to 2 pts. of melted sperma-
ceti, treat the resulting soapy mass witii water, and then with a slight excess of hvdro-
chloric add. On boiling the liquid, the ethal and the fatty ad£ of the soap nse to
the surface, in th^ form of an oily layer, which is separated by decantation, and
saponified a second time in the same manner, to decompose a small remaining quantity
of spermaceti ; the fatty acids are again separated by means of hydrochloric acid, and
saponified with slaked Ume added in excess. A mixture of lime-soap and hydrate of
cetyl is thus obtained, from which the latter is dissolved out by alcohol. Lastly, the
alcohol is distilled ofiT, and the cetylic alcohol which remains is purified by cnrstallisa-
tion from ether. Heintz boils spermaceti with an alcoholic solution of potash ; pred-
pitates the boiling liquor with a concentrated aqueous solution of chloride of barium ;
and dissolves out the ethal from the predpitate with alcohol. As the alcohol also dis-
solves small quantities of barium-safts, it is removed by distillation, and the ethal
which remains is dissolved in cold ether, and finally purified by several crystallisations
from ether.

Cetylic alcohol or ethal is a white solid crystalline mass, which melts at a tempera-
ture above 48° C, but solidifies at 48° (Chevreul). It melts in water at 50° C, and
when it solidifies,, the temperature rises to 51 '5° ; when melted alone, it solidifies at
49° or 49*5° (Heintz). When slowly cooled, it crystallises in shining laminse: it
also ciystalliBes on cooling from solution in alcohol. It is without taste or smeU, and
distils without alteration, passing over even with vapour of water. It is insoluble in
water, but mixes in all proportions with alcohol and ether.

Ethal does not give off water when heated with oxide of lead. It is not dissolved
by a^ueotu alkalis; but when strongly heated wii^ potash-liTne, it gives off hydrogen,
and IS converted into a potassium-salt> probably palmitate or ethalate (Dumas and
Stas, Ann. Ch. Phys. [2] Ixxiii. 124) :

C»«H"*0 + KHO - 0>fH"KO« + 4H.

Ethal is decomposed by sodium, yielding cetylaie of sodium, C^'H^^O. Wiihpotash
and sulphide of carbon it forms celyl-xanthate of potassium, C>^**.KCOS'. Distilled
with perUachloride of phosphorus, it forms chloride of cetyl, oxyehloride of phosphorus,
and hydrochloric add:

c««H".H.o + pa*.ci« - c»«H»a + tcih> + hcl

With iodine and phosphorus, it yields iodide of cetyL With strong sulphuric acid, it
forms cetyl-sulphuric add, C"H".H.SO«.

Heintz (loc. cit) regards ethal, not as a simple alcohol, but as a mixture of cetylic
and stearic alcohols, C"H»*0, and C»"H"0 : because, accordinc to his experiments,
the ethalic add of Dumas and Stas, is a mixture of palmitic and stearic adds, sepa-
rable by solution in boiling alcohol and precipitation by acetate of barium.

CSTT&, ZOUIBB OF, C»«H»I. (Fridau, Ann. Ch. Pharm. Ixxxiii 9).— Pre-
pared by introducing phosphorus into cetylic alcohol heated to 120° C. in an oil-bath,
and adding an excess of iodine by small portions at a time, while the mixture is con-
tinually stirred. Hydriodic add is then given off, together with phosphorous add, while
iodide of phosphorus crystallises out, and iodide of cetyl remains in the liquid state.
When the reaction is complete, the iodide of oetrl is decanted, washed with cold
water, which causes it to solidify, and then crystallised from alcohol. It cryrtallises
in colourless interlaced laminae, insoluble in water, easily soluble in ether, more soluble
in boiling than in cold alcohol Melts at 22° C, and solidifies on oooluog in rosettes
having a fatty aspect Bums with a dear flame, giving off free iodine.

It does not distil trithout alteration, but decomposes quickly at 250° C, giving off
copious vapours of iodine and hydriodic add, together with an oily hydrocar1x>n. It is

842 CETYL: NITRIDE — SULPHTDRATE.

yiolently attacked hy mereurio oxide at 200°, yielding an oil (cetene?) together with
iodide of mercorr and metallic mercnrj, and leaving a cryBtallisable solid foBible at 60?.
With oxide of alver recently precipitated, and still moist, it forms the same compound,
melting at 6QP. With oetylate of sodinm it yields iodide of sodium and oxide of oetyl *

C«H«K,0 + C»«H».I - KI + (C»«H»)H).

Ammonia in solution does not act on iodide of oetyl, but gaseous ammonia oonTerts
it ioto tricetylamine, N(C**H^. With phenylamine it fonns oetyl-phenylamine and
dicetyl-phenylamine. (Fridau).

CWTTMh mTBZBB OF. See Gbttlaiomb.

or. OUyUo ether, (Ci*H**YK).— Obtained by treating oetylate of

sodium, C"H"KO, with iodide of cetyl at 110° C., washiof the nroduct with Doiling
water to remoTO iodide of potassium, and ciystallising com alcohol or ether. It
crystallises in shining scales. Helts at 561^ C, and solidiftes between 53° and 64° in
a radiated mass ; distils at 300° for the most part without decomposition. It is not
attacked by hydrochloric or nitro-hydrochloric acid at the boiling heat, but strong sul-
phuric acid destroys it. (Fridau, Ann. Ch. Pharm. IxxxiiL 20.)

CetyUethyl-oxide or oetylate of ethyl^ CTI*.C"H".0, and cetyUamyUoxtde or eetylaU
of amylj G*H".C'*H".0, are obtained in like manner by treating 'oetylate of sodium
with iodide of ethyl or amyL They both crystallise in lamina^ soluble in alcohol
or ether: the ethyl-compound melts at 20° C, the amyl-compound at 30°. (G. B ecker,
Ann. Ch. Pharm. di. 320.)

Cetylsodium^unde or oetylate of eodium, C*'il"NaO, obtained by the action of
sodium or cetylic alcohol, is a greyish-yellow solid which begins to meft at 100° C. and
is perfectly fluid and transparent at 1 10°. It is not decomposed by boiling water, bat
hydrochloric acid separates cetylic alcohol from it. (Fridau.)

CBTTXi, BTBA&Am OF. G*«H«0* » C»H"O.C>«H».0.— Piepaied like the
butrrate. Thin white shining lamine, sparingly soluble in boiling alcohol and in
cold ether, easily in boiling ether. Melts at 66^ — 60° 0., and forms a crystalline mass
on cooling. Volatilises wiui partial decomposition when heated in a tubei (Handw.)

CBTT&, SVCCXWATB OF. C«H«0* « (C«HH)«)''.(C'«H")«.0»— Prepared br
heating 1 at. succinic acid with 2 at. cetylic alcohol in an air-bath, neutralising with
carbonate of sodium and recrystallisinff from ether. White laminiR, sparin^y soluble
in alcohol, more freely in ether-alcohol, still more in pure ether. (Tutschef^
loc. eit,)

camip muunULTM (AOIB) of. CetyUut^hurie acid, Sulphoeetio add,

C"H"SO* - (.(^i^^ 1 0« —Produced by mixing sulphuric acid with cetyUo alcohol

at the temperature of tne water-bath (D umas and P^ligot, loo. eit,) According to
Kohler (loc, eit,) and Heintz (loe. eit) the most abunoumt product is obtained by
mixing the two substances at the lowest temperature at whidi they wiU act, tie. at
the meltinff point of cetylic alcohol ; dissolying the mixture in alcohol and saturating
with potasn; separating the precipitate from the liquid; concentrating the latter;
treating the residue with ether, which extracts undeoomposed cetyUo alcohol, and
leayes cetylsulphate of potassium ; and repeatedly eaystallimng the latter from boiling
aloohoL

Cetyl8tdj[)hate of potassium fbrms white nacreous laminae, consisting of interlaced
microscopic needles ; it is moderately soluble in hot alcohol, less in boiling water, in-
soluble in ether. It is not fhsible. Heated to 140° 0. with cyanide of potassium, it
yields cyanide of cetyL

CBTTIi, SVUPXIBB OF. (C^fH^^— Prepared b}r the action of chloride
of cetyl on an alcoholic solution of monosulphide of potassium at the boiling heat.
Chloride of potassium then forms and sulphide of cetyl rises to the surface of the
liquid, where it solidifies on cooling. It is then washed with cold water, melted in
boiling water, and repeatedly crystallised from a mixture of alcohol and ether, till the
melting point becomes fixed at 67'5° G. It forms shining scales resembling those of
cetylic mercaptan. It dissolres readily in ether, and in boiling alcohol, veiy sparingly
in cold alcohoL The alcoholic solution forms a white precipitate with acetate of
lead, also dissolved in alcohol (Fridau, Ann. Ch. Pharm. lyrn'ii 16.)

CBTn, SmbrcmBATB of, Cetylic Mercaptan, C^*H".H.a —Prepared
by treating sulphydrate of potassium dissolved in alcohol with an alcoholic solution of
chloride of cetyL The product contains a certain quantity of sulphide of ce^L It is
purified by adding acetate of lead, then water, washing wititi water, and digesting in
ether, which dissolves the cetylic mercaptan and deposits it on evaporation in ccystal-
line scales having a silvery lustre. It melts at 60'6°G., but solidifies again only when
cooled down below 44°, assuming the form of interlaced dendrites. It is sparingly

CETYLAMINES — CHABASITE. 843

BoluHe m eold aleohol, easily in ether, somewhat less easily in boiling aloohoL When
boiled with water it gives off a peculiar odonr.

The cold alcohoHc solution produces, after a while, white flocculent precipitates with
the alcoholic solutions of silver^salts and of mercuric chloride ; it does not precipitate
the salts of lead, platinum or gold. Mercuric oxide does not act sensibly upon it»
even at high temperatures. (Fridau, Ann. Oh. Phazm. Izzxiii. 18.)

CWmUkMUKMBm Bases formed by the substitution of one or more atoms of
cetyl in place of hydrogen in a molecule of ammonia. MonO' and direetylamxne are
not known.

Trioetylamine or JHiride of Cetyl. CH"H*W-NfC»«H»)» — This base is produoed
by passing ammonia-gas into iodide of cetyl heated to 150^ 0. A white precipitate
of iodide of ammonium is then formed, increasing in quantity if the temperature be
maintained for a while at 180^, and the substance which remains in the fused state is
tricetylamine. It dissolves in boiling alcohol and crystallises in colourless needles,
melts at 89^ C. and solidifies in inammellated crystals on cooling.

The salts of tricetylamine are insoluble in water, but soluble in ether and alcohol,
especially in the hot liquids. The hydrochhrate^ O^H'N.HGl, crystallises from boiling
alcohol in needles^which are less fbsible but more soluble than the base itself. Potash
added to the boiling solution separates tricetylamine in the form of a heavy oiL
The cKhroplaiinate, 0*H*N.HCLPtCl", is a cream-coloured, almost pulverulent pre-
cipitate, insoluble in water, sparingly soluble in aloohoL (Eridau, Ann. Ch. Pharm.
Ixxxiii. 25.)

CetylphenylaTnine, N.H.C»«H".C«H», and JHeeiylnhenylamine, N.(C»"H«^«.CWB:», azo
produced by the action of iodide of cetyl on phenylamine {q. «.)

CWnrXp^LaXTBZO ACIB. C"H*«0S*« J«^"^|s>.~-This add is known only

as a potassium-salt, which is prepared by adding alcohol and hvdrate of potassium to
a saturated solution of cetylic alcohol in sulphide of carbon, heatine the mixture s
little below the boiling point of alcohol, then leaving it to itself for a while and
decanting. The dear solution, on cooling, deposits light scales, which maybe purified
by washing with a small quantity of cold alcohol and dissolving in boiling alconoL

The salt is white, tasteless, odourless, very hygroscopic and unstable. Its alcoholic
solution gives a white predpitate with mercwric chloride; canary-yellow with nitrate
of silver^ blackening in a few minutes; white with acetate of l^id, also bladcening
n^idly ; white gelatinous with salts of sdnc. Digested with hydrochloric add, it yields
cetylic alcohol. (Desains and De La Frovostaye, Ann. Oh. Phys. [3] vi 494.)

CSVAOZC ACZB. An add- existing in the seed of sabadilla ( Verat'ntm 8aba^
dilla^ Bitz), and probably ateo in the root of white hellebore ( Veratrum album\ and
of Colekicum avtumnale. To prepare it, the oil extracted from sabadilla seeds by
ether is saponified with potash; the soap decomposed by tartaric add ; the mixture
distilled ; the distillate neutralised with baiyta ; and the resulting barium-salt eva-
porated to dryness, and distilled witJi syrupy phosphoric add. Oevadic acid then
sublimes in white nacreous needles. It is soluble in water, alchohol, and ether, and
smells like butjrric add ; melts at 20^ 0. and sublimes at a temperature a few defp^ees
higher. Its salts have a peculiar odour. The ammonium-salt gives a white predpitate
with ferric salts.

OSVA9IM or MOSBBnr. A mixture of starch, cellulose, and azotised matter
obtained from barley.

onXAWITM or OSTXi<MRTB. A ferruginous variety of spinel (Al^BffgO*),
from Oeylon, and other localities, having the magnesium more or less replaced by
ferrosum, and the aluminium by ferricum. It is the pleonast of Hauy. (See Spinel.)

CHABASZra. A mineral belonfi;ing to the zeolite fiunij|y, and consisting es-
sentially of hydrated silicate of aluminium and caldum, a certain portion of the
calcium bcin^ however always replaced by potassium or sodium. It ciystallises in
forms belonging to the hexagonal system. Primary form, an obtuse rhombohedron,
having the angle of the terminal edges = 94^ 46'. It occurs in the primaiy form, and
in the combination R. — }B. — 2B. Batio of prindpal to secondaiy axes » 1*086.
Oleavage distinct parallel to B. Specific gravity 2*0 to 2-1. Hardness 4 — 4*5. Trans-
parent and colourless, sometimes fiesh-red, with vitreous lustre. Streak uncoloured.
Practnre uneven. Brittle. Shrinks before the blowpipe to a blistered, slighdy trans-
lucent enamel It is perfectly decomposed when heated in the state of powder before
the blowpipe. It occurs in scattered crystals in the fissures of some trap rocks, and
in the hollows of certain geodes disseminated in the same rocks.

The composition of most varieties of chabasite is nearly represented by the formula
OaK)AlH)».4SiO« + 6aq., which (ifa/=|Al), may be reduced to that of a meta-
silicate (Oa afl)SiH)* + 3aq. Sometimes, however, the amount of alkali is consider-

844 CH^ROPHYLLUM — CHALCOPHACITE.

able, 88 in the fourth of the following examples, which approaches neariy to

M^l^i^'O' + S^i.

Analysis a is of a speoimen from ffilmalcolm in Benfrewshire, bjrThomson ; b, from
I Aussig in Bohemia, by Bammelsbeig; c, from Annerode near Oiessen, bj Ghmth;

^ d, from Port Bush in Ireland, by Thomson :

i 8tOS AHO> Fe«OS Ca^O VtM K'O WO

' a . . 48-75 17-44 — 1047 — l-4« 21*72 - 99-93

! b , . 47-91 1814 — 964 0-26 266 21-60 « 10000

, c . . 47-00 19-71 0-16 10*63 0*66 OSS 2229 = 10076

I d . , 48-99 19-77 0*40 4*07 607 — 20*70 «. 10000

Sometimes, however, the proportion of silica is somewhat greater, and the oom-
i position is more neailj represented by the fbrmnla 2(GaK).Al*0').6SiO* + 12aq. or

(Ga*a^*'H')Si*C+ llaq. ; and here again, the proportion of alkali-metal maybe con-
siderable, as in the yaiiety called acadiolite, which may be represented by the formnlA

" (Ca^a^B?)*aP*H*Si*0"+llaq. Analysis e is chabasite from Drottning GrafTa

t near Ghistassbeig in Jemtland (Berzelius); / is acadioliUf from New Caledonia

\ (Hayes):

s . . 60*66 17*90 9*37 — 170 19*50 « 99*62

/ . . 62-02 17-88 4-24 4-07 3-03 18-30 « 9964
\ (Rammdsber^B Minerakhemie, p. 816.)

:; According to Dana, HaydeniU from Jones' Falls in Maryland, is merely a fermginons

Yariety ofchabasite ciystaUised in scalenohedrons. — Phacolite from Leipa in Bohemia is
another mineral of similar constitation, bat containing less water, viz. (M*a/^'H')Si"0*'

^ +Oaq.

OKBROVBTIi&IJBIa The fleshy root of CharcphyUum btUbosumf which is now
coming into use in France as an article of food, has been examined by Pay en (Compt.
rend. zliiL 269), and compared with that of the potato (a yellow Tariety) :

ChcrophyUum. Potato.

I Water 63-618 . . . 7400

Starch, &c 28*634 . . . 2120

Cane-sugar 1-200

Albumen and other nitrogenous substances . 2-600 . . • 1*60

Fat 0-348 . . . 010

Inorganic matters 1-600 . . . 1-66

i Cellidose and pectin-substances . . . 2*100 . . .1-64

The comparison is evidently to the advantage of the chserophyllum. According to
Polstorf (N. Aidi. Pharm. v. Brandes, xviiL 176), the seeds of this plant contain
an alkaloid, oharophylline. Host species of chserophyUum are aromatic

An idmaceous plant possessing poisonous seeds.
Native sulphate of copper. (See Sxtlfhatss.)
or Calcedony. — ^A variety of quartz exhibiting various shades of
white, yellow, grey, brown, green, and blue. It has usually the subdued lustre of wax,
and is transparent or translucent, some milk-white varieties being opaque. It occurs in
mammillaiy and botryoi'dal shapes, and as stalactites in cavities roofed or lined with it.
According to Fuchs, it is true quartz with some opal disseminated through it. Va-
rieties of chalcedony are: agate, camelian, cat's eye, chivBoprase, flinty homstone,
onvx, plasma, and sand (^t^.) Common chalcedony occurs m the toadstone of Derby-
shire, m the trap rocks of Fifeshire, the Pentland HjUs, and the Hebrides ; magnificent
specimens also m Trevascus Mine in Cornwall, in Iceland, and in the Faroe Isles.

CBA&COBZTB. A hydrated magnesio-ferrous silicate found near Antwerp in
Je£ferson county. New York, and originally mistaken for cacoxene. It occurs in
stellate globular masses, having a bronze-like aspect, or as a deposit upon red hffima-
tite; also in prisms with very distinct cleavage in one direction. Transluoent^
yellowish-brown to blackish-^reen, with somewhat lighter streak. Lustre metalloidal ;
on the cleavage faces, metaUic and nacreous. Very flexible in thin laminae. Hardneaa
1 to 1*6. Before the blowpipe, it gives off water, and exhibits the reactions of iron.
Hydrochloric acid does not act upon it in the cold, but when heated, decomposes it
with separation of siUca. (C. XT. Shepard, SiU. Am. J. [2] xiv. 266.)

CBAZiOO&ZTB. See Ubakitb.

Octahedral arsenate of copper. (See Lutoooxms.)

CHALCOPHYLLITE - CHAMPAGNE WINE. 845

L Syn. with Copphb-mtca.
CBAXiOOVTXXTB. Syn. with Copfeb-ftbitbs.

Natiye snlphantimonite of copper. (See Wolfsbeboxtb.)
L Native cuproua oxide. (See Coffbb, Oxides of.)
This name is applied to two miBeraU found imbedded in grey
iilmond-stone, from the county of Antrim in Ireland. One of these minerak ib
amorphous, with conchoidal fracture ; cream-coloured, with &int waxy lustre ; trans-
lucent on the edges, with faint lustre on the streak ; slightly unctuous to the touch,
and adhering to the tongue. In water, it falls to pieces with decrepitating noise. It
is decomposed by hydrochloric acid, with separation of pulverulent silica.
According to v. Hauer (Wien Acad. Ber. ziL 229) it contains

SiOS Al^QS FeSO Ca*0 M««0 HSQ ToUI.

4411 10-90 105 674 1301 2407 - 9988

-with traces of manganese and potassium, whence the formula: 4M'O.A1^0'.6SiO* +
13H«0.

The other mineral (first analysed by Thomson), is a dense segregate of concen-
trically fibrous spherules, of pale blood-red colour ; gUstening ; translucent on the edges ;
of haidness 6, and specific gravity 2*24. It does not fall to pieces in water, and when
decomposed by hydrochloric add, yields a jelly of silica.

ThisminenJ, analysed by y. Hauer (Wien Acad. Ber. xi 18) gave:

.LoM by

SiOS

Al<0»

F««0»

CaSO

M8«0

ignition.

Tout.

38-26

27-71

trace

12-01

6-86

14-32 »

9915

whence the formula 6M*0.4Al*0*.9SiO* + 12H'0 (Senngott, Jahresber d. Chem.
vi. 826 ; vii. 842). Both* minerals are orthosilicates, the formula of the first being
reducible to (M»a^H")Si«0« + 7aq. which is of the form 6R<SiO* + 7aq., and that of
the second to (M*a/")Si*0»* + 4aq. or 3R<SiO* + 4aq.

OBAXJK* Friable carbonate of ealdum, veiy abundant^ and forming the upper
member of the cretaceous group which occupies nearly the whole of the south-eastern
part of England, and a considerable portion of the north of France. It is white and
opaque, very soft, and without the least appearance of polish in its fracture. Specific
gravity 2*4 to 2-6. It contains about 2 per cent of day, besides free silica. Some
specimens, perhaps most, contain a little iron. Sometimes also magnesia and chloride
of ealdum occur in small quantities. It may be purified by trituration and elutria-
tion, the ferruginous and siliceous partides subsiding first, while the pure chalk
partides remain suspended : this purified chalk when dried is called whiting. Chalk
IS extensively used in agriculture, as an addition to soils which are defident in
lime.

The name chalk is also occasionally applied to other earthy minerals ; thus Black
ehalk is a peculiar kind of slate, also called Drawing slate, which produces a black
shininff streak on paper, and is used in crayon drawing. S^ chalk is a clay, coloured
by oxiae of iron.

cnA&X BTOns. Oouty concretions in the joints, so called from their resem-
blance to chalk. They consist mainly of uric add.

CHAXJLOSnrB. Syn. with Coffxb-olancs.

COLAXTBBATB ^VATB&S. Mineral waters containing carbonate of iron dis-
solved in excess of carbonic acid (p. 785).

Native carbonate of iron (p. 784),

BOWBHAA. Manganate of potsssium. (See Makoakatbs.)

BVMZZiXB. The leaves of this palm are coated with wax,

separable by alcohol into cerin and myridn. (Teschemacher, Sochleder^s Phvtoehemie.

p. 219.)

CBAMOZBXTB. A black earthy mineral from Chamoisin in the Yalais, contain-
ing, according to Berthier (Ann. Min. v. 393), 14*3 per cent silica, 60-5 ferrous
oxide, 7'8 alumina^ and 17'4 water (=.100), with 15 per cent of carbonate of ealdum.
It is perhaps a mixture of magnetic iron ore with a hydrated silicate of aluminium.

OBAMOTTa. A mixture of fire-day and fragments of burnt potteiy used for
making fire-bricks, pl^s, crucibles, &a Chamotte-stones from the kaolin of Halle,
were found by Wackenroder (Arch. Pharm. [2] Ixxv. 27), to contain 85-00 per cent
silica, 11*33 alumina, 2*23 ferric oxide, and a trace of magnesia; loss by ignition 1*00.

CKAMVAaWB VFTMM is made from selected grapes, red and white, the must
of which, after fermenting in the vats from 12 to 15 hours, is drawn dear off into the
casks ; it is racked off about Christmas, once more after four weeks, and then fined with

846

CHANTONITE — CHEESE.

ifluiglass, which treatment is also repeated. The new wine is put into stout botdea in
the month of Majj leaving about 2 inches empty under the corks, which are wized
down ; and the botUes are laid on their sides for the progress of the fermentation :
from 6 to 10 per cent, of the bottles burst. This stage ^ the process is completed
in September, when the bottles are placed on their mou^s, and left so for fourteen daya
to let the sediment settle in the neck, which settlement is promoted by a slight shak^
ing. By dexterous opening of the bottles, the muddy deposit is discharged, and they
are then filled up with dear wine, corked afresh, and packed up for transport, the cork
being covered either with melted resin, wax, or tin-foiL In seasons or districto
when the must is not sweet enough, sugar is added by pouring a thimble-fuU of syrup
^called liquor), into each bottle, the wine destined for Bussia receiying a double
dose.

A like procedure is followed in making the spailding wines of Germany, as on the
Moselle, and at Esslingen in Wurtomburg. Carbonic acid gas is frequently condensed
hy an air-pump into the other more or less factitious frothing wines of fVaace and
Germany. XT.

CMJUkMrOWirMm A mineral said to exist in certain meteorites (;.«.)

CHABA riBTUMu The ash <^ this plant has been analysed by Schula-Fleeth
(Fogg. Ann. Izxxiv. 80^. Two specimens of the dried plant yielded 64*58 and 68*39
per cent, of ash, the chief characteristic of whidi was the very large quantity of lime
which it contained, viz. 42*7 per cent., which exists in it almost entirely in the form of
carbonate. The water in which the plant grew yielded in 100 pts. 0*1618 pt of solid
mattei^ of which 0*104 consisted of carbonate of calftium.

cnfABfggA'L. See CABBOir (p. 769) ; also Ur^s JHcHonary of JrU, Manufac-
tures and Mines, i. 615).

caULTBAmXSL Kative arsenide of cobalt. (See Cobalt.)

CBAVZOA omCMMJLBXrWim One of the names of the plant whieh yielda
long pepper, (See Peffer.)

CBAT or €SH£LT Jk BOOT. The root of the Oldenlandia umbeUata, whidi grows
wild on the coast of Coromandel, and is likewise cultivated there for the use of dyers
and calico-printers. It is used for the same purposes as madder, to which it is said
to be far superior, giving the beautifiil red so much admired in the Madras cottons. U.

CBMB8B is formed from milk by coagolating it with rennet; separating the curd
from the whey ; compressing the curd in moulds, after it is duly seasoned with salt ;
and keeping this solidified milk in a cool place for some time, to allow it to undergo
a kind of fermentation, by which it acquires the flavour and other well known pro-
perties of cheese. The chemical changes undergone by the casein in this process
are little understood. The milk, before it is coagulated, should be heated to about
85° F. ; then it receives the rennet — the infusion in water of the stomach of a new-
bom calf, commonly salted and dried to make it keep. The rennet effects its curdling
completely in about an hour and a hall The curd is cut with a three-bladed knife ;
drained of its whey; broken down by hand or otherwise, subjected to compression;
then comminuted more completely; put into its mould; and exposed to a graduated
pressure, commonly under a heavy weight, but in large dairies by a screw press, which
can be progressively tightened. The comminuted curd may be well salted by en-
closing it in linen cloth and immersing it for one day or several days in brine. It is
then Gained, wiped, and set away in a cold room. Soquefort cheese is made from a
mixture of sheep and goats' milk, and is ripened in a chamber or cellar having a
very low temperature. U.

The following table exhibits the composition of seyeral kinds of cheese, as deter-
mined by Pay en (J. Pharm. [3] rvi 279).

Composition of Cheese,

Water
In

Ash

inlOUpts.of
substance:

Nitrogen
in 100 pu. of sobstaoce:

Fat

In 100 pU. of
subtian<».

100 pta.

^^ t

1.^. *

Cheese from Chester

normal.

dry.

normal.

dry.

ash.free

normal.

dry.

ao-39

4-78

6*88

5-56

8-00

S-fS

85-41

36*61

(«

Brie .

63 99

6-63

12-08

3-39

R-14

• 6-86

24-83

33 29

Neufchatel

61 R7

4-26

1117

2*28

6-99

6-07

18-74

49-15

»*

Marolle*

40*07

5*93

9-91

373

994

6-92

28-73

47*95

Roquefort
Holland

26&3

4M6

606

6 07

6-91

7-35

82«31

43-99

»*

41-41

6-21

10*61

410

701

784

2506

4278

Oruydres

32-05

4-79

705

5-40

796

8-&9

28*40

41*81

Parmetanu .

30-31

709

10-18

5-48

7 87 8-76

SI 68 81-19

co«

P«0»

NaCl

008

13*68

72-47 - 10102

008

20-45

66-87 « 100-88

CHEIRANTHUS CHEIRI — CHELIDONTC ACID. 847

The ash of two samples of cheeso has been analysed by Johnson (Ann. Ch. Pharm.
Izxriii. 119): a. Hand-cheese {Hand-Kdae) from the neighbourhood of Giessen;
b, Swiss cheese.

K»0 NaK) Ca*0 Mg*0 Fe*0»
4-86 7-38 2-66 — Oil

2-46 8-67 17-82 081 017

The hand-cheese exhibited an alkaline reaction ; gaTe off 46*36 per cent water at
I00<^ C. ; the dried substance yielded 12-86 per cent, nitrogen and 13*16 per cent ash.
The Swiss cheese yielded 44*70 per cent water, and, after drying, 8*0 per cent nitrogen
and 11-36 per cent ash.

On the preparation of cheese, see Draiii de Chinue ginhale^ par Pelouge et Frhny, ■
2"** 6d. yi. 213, and Muapraifa Chemistry ^ article Chbbsb.

CBanuUTTBim CBBXSZ. Wallflower,— The fragrant flowers of this plant
have a bitter taste like that of cress. They contain a substance which assumes a
carmine colour in contact with sulphuric acid. The seeds contain myrosin, but no
myronic acid. {BochUdei's Phytochemie^ p. 98.)

cnn&mTTHSZWBb An alkaloid em'sting in yeiy small quantity in Chdido-
nium majus (Probst^ Ann. Oh. Pharm. ttit. 120 ; zzxi. 260).^ It forms orange-red
salts, and, according to 8 c hi el (SilL Am. J. [2] xz. 220), is identical with sangui-
xiarine, C'*H*^0\ the alkaloid of aangmnaria canadensis, (See Sanouinabi2«b.)

CrSVLSDOXnC ACXB. G'H^O*^ ^'^h!|^* (Probst Ann. Ch. Pharm. zzix.

116.— Lerch, ibid. Ivii. 273.— Hutstein, N. Br. Arch. Ixr. 23.— Gm. xiv. 413.—
Gerh. iii. 764). — This acid exists in all parts of Chelidonium majus, the common
celandine, in the form of a calcium-salt, together with malic acid and another acid,
probably fumaric : it is most abundant at the flowering time. To obtain it, the ex-
pressed juice is coagulated by heat and filtered. The filtrate is acidulated with nitric
acid, and nitrate of lead is added in small quantities, as long as a crystalline precipitate
falls, care beins taken not to add too much either of the acid or of the lead-salt The
precipitate, which contains lime, is difiused in a large quantity of water and decomposed
by sulphuretted hydrogen, which takes place slowly ; the solution of acid chelidonate
of calcium is neutralised with chalk and boiled with animal charcoal ; and the neutral
liquid is eyaporated till saline crusts form. After cooling, white crystals are obtained,
of a silky lustre, which are to be purified by repeated crystallisation. To separate
the acid, the chelidonate of calcium thus obtained is dissolyed in water, the solution
precipitated with carbonate of ammonia^ and the concentrated solution of chelidonate
of ammonium mixed with twice its yolume of moderately dilute hydrochloric acid.
Ghelidonic acid is then precipitated as a mass of crystalline needles, which are to be
drained on a filter, washed, and purified by crystallisation from hot water.

Ghelidonic acid thus prepared contains 2 at water of crystallisation, C'H*0*.2HK),
which it giyes off (amounting to 9-2 per cent.) at 100® C., or when left oyer oil of
yitrioL By spontaneous eyaporation it may be obtained in long needles containing
8 at water (12*7 per cent). It dissolyes sparingly in cold, more freely in boiling
water, tiie solution solidifying as it cools. According to Probst, it requires for
solution 166 pts. of water at 6° C. and 26 pts. at 100®. It dissolyes in hydrochloric
and sulphuric acids more abundantly than in water, and in 700 pts. of 76 per cent
alcohol at 12® 0.

The acid dried at 100® C. giyes off 2*0 per cent (} at) water at 160®, probably
with partial decomposition. If the heat be continued, no farther loss takes place
short of 210®; but at that temperature the acid sustains a considerable though not
determinable loss; between 220® and 226® decomposition takes place, the residue
becoming soft, blackening, and giying off carbonic anhydride. The black mass, treated
with water, yields an acid which crystallises in yellowish crusts. Ghelidonic acid
bums with slight detonation when heated in the air. It is scarcely attacked b^ strong
nitric acid : but moderately dilute nitric oonyerts it, with erolution of nitnc oxide
and carbonic anhydride, into another acid ; malic acid does not appear to be formed.
Ghelidonic acid dissolyes without decomposition in cold oil of yitriol ; but on the appli-
cation of heat, the solution becomes yellowish, and giyes off gas-bubbles, assumes a
fine pun>le-red colour at the boiling heat, but after long boiling, gives off sulphurous
acid and aci^uires a dull undefinaue colour. When the calcium-salt is boiled with
potash, oxahc acid is produced. (Lerch.)

Ghhudokatbs. — Ghelidonic acid is a strong acid, dissolving zinc and iron, with evo-
lution of hydrogen, and decomposing carbonates. It is tribasic, its salts being trifM-
tallie, G'HMK)« dimetallic, G'H«M«0«, or mowmeiaUie, G^^MO", besides a few add
salts containing G'H"MO« C'H<0<.

848 CHELIDONIC ACID.

The dimetaUic chdidonates are formed when the acid is neutralised with a metallio
oxide or a carbonate ; with alkalis or their carbonates, trimetallic salts are apt to form.
Most of the dimetallic salts are soluble in water and crystallisable; they contain
several atoms of water, which are given off at or above 150^ C. ; the ammonium- and
silver-salts, however, become anhvdrous at 100^. Those which contain colourless
bases are tiiemselves colourless. I'hey have no action upon litmus. The monometallic
salts are produced by heating the dimetallic salts with about | of their weight of free
chelidonic acid or a dilute mineral acid. If the acid is in excess, acid salts are pro*
duced. The monometallic salts are resolved by repeated recrystallisation into acid and
dimetallic salts. The trimetallic salts are formed by treating the dimetaib'c salts with
a caustic alkali or alkaline carbonate. Those which contain colourless bases have a
fine lemon-yellow colour ; those which are soluble impart a deep colour to the water.
Most of them contain several atoms of water, which are not given off at 100^ 0. They
have no reaction upon litmus. They are decomposed by continued contact with water ;
those of the alkali-metals absorb carbonic acid from the air and yield a dimetallic
chclidonat« and a carbonate.

The add chelidonates ciystallise from the solutions of the dimetallic salts in hot
hydrochloric acid, in delicate needles or scales, which do not give off their water of
crystallisation at 100^ C. They redden litmus, and may be recrystalliBed, but give up
their base when repeatedly treated with hydrochloric acid.

Chelidonate of Ammonium. C'H«{NH:*)«0«.— A boiling dilute solution of the
dicalcic salt neutralised with carbonaj;e of ammonium, filtered and evaporated, yields the
ammonium-salt, on cooling, in snow-white silky needles. The sohition abandoned to
spontaneous evaporation, ultimately solidifies to a transparent mass, which when col-
lected and drained on a filter, fields the ammonium-salt in long capillaiy crystals re-
sembling a knot of the finest silver- white hair. It effloresces in contact with the air,
gives off 14*23 per cent. (2 at.) wat«r at 100^ C, and then exactly resembles sulphate
of quinine. (Lerch.) It does not give off ammonia, either when exposed to the
air at ordinary temperatures, or when heated to 100®. Heated above 160°, it turns
brownish and gives off carbonate off ammonium ; the residue does not contain any other
acid. By repeatedly evaporating the solution and redissolving the residue, it is
converted into the acid salt. It does not form a trimetallic salt when treated with
carbonate of ammonium or caustic ammonia. (Lerch . )

Chelidonates of Barium.— The triharytic salt, C'HBa«0«+ Satj. (at 100<'), is
obtained by mixing a hot solution of the dibaiytic salt with ammoma, precipitating
with chlonde of barium, and quickly washing the precipitate with water. It is a
lemon-yellow powder which does not give off water at 100° C. It absorbs carbonic
acid from the air, dissolves sparingly in water, not at all in alcohol.

The diharytic salt^ C'H'BaK)* + aq., is obtained by decomposing the corresponding
calcium-salt with a soluble barium-salt, or by neutralising the aqueous acid with
baryta or its carbonate. It is colourless, crystalline, and very brittle; soluble in
water.

The acid salt, C^H'BaO*.C^^O* + 2aq. is produced by dissolving the tribarytic salt
in boiling hydrochloric acid.

Chelidonates of Calcium.— The tricalcic salt, C'HCa«0« + 3aq. (at 100° C.) is
prepared bv boiling the dicalcic salt with ammonia, or by decomposing the sodium-salt
mixed with ammonia with chloride of calcium. It is a yellow amorphous powder,
veiy little soluble in water, insoluble in alcohol.

The dicalcic salt, C'HK)a«0*+ 3aq. (at 100°), occurs in Chelidmium majus (p. 847).
It crystallises in silky prismatic needles, very little soluble in cold water, but easily in
boiling water ; insoluble in absolute alcohol. The solution does not affect litmus. The
salt is not efflorescent, and does not part with its wat^r of crystallisation below 160° C.

The acid salt, CH'CaO'.C'H^O* + 2 aq., obtained by decomposing the preceding
with hydrochloric acid, crystallises in needles.

Chelidonate of Copper, — Green sparingly soluble prisms, obtained by evapo-
rating a mixture of an alkaline chelidonate with sulphate of copper.

Chelidonates of Iron, — The aqueous acid dissolves iron, farnang ferrous cheli^
donate.

Ferric Chdidonate.^Fe*0:C^*B*0^* = 2C^/fl"0« + H«0.— The solution of iron in
chelidonic acid passes to a higher degree of oxidation during evaporation, and deposits
a dingy yellow precipitate. Tne disodic salt forms with aqueous sesquichloride of iron,
a dingy yellow precipitate, somewhat soluble in acetic acid and in excess of sesquichlo-
ride of iron ; it does not diminish in weight at 100° C, and if set on fire at one point-,
bums away with a sparkling light, leaving charcoal and sesquioxide of iron. (Lerch.)

When chelidonate of potassium is mixed with excess of sesquichloride of iron, the
greater part of the ferric chelidonate remains dissolved; the pale yellow filtrate

CHELIDONIC ACID — CHELIDONINE. 849

gradually assiimes a darker colour, and nltimatelj becomes black-brown and opaque,
but recovers its pale yellow colour after some time ; on heating the liqnidi the changes
of colour take place more quickly. The dark brown liquid forms with ammonia a
rusty brown precipitate, which becomes black when treated with a larger quantity of
ammonia^ probably from formation of protoxide of iron.

Chelidonatea of Lead.^A basic salt, 2C'HFb*0<.3PbK), is obtained by adding
the diplumbic salt mixed with ammonia to basic acetate of lead.

The triplumbic salt, CBPb'O*, is produced by treating the diplumbic salt with
ammonia, or hj mixing a cold solution of dicalcic chelidonate with basic acetate of
lead. Yellowish-white flakes are then deposited containing ^ at. water (2C'HPb'0*.
3H*0), which is given off between 150^ and 160^ C, the salt then turning yellow. If
the solutions are mixed at the boiling heat, the anhydrous salt is product at once in
the form of a lemon-yeUow precipitate, darker in colour if mixed with the preceding.
It is decolorised and decomposed by acids. Insoluble in water and in alcohol, soluble
in lead-salts.

The tUplumbic salt, CW^H)* + aq., is deposited, on mixing the dicalcic salt with
nitrate of lead, in small shining crystidline scales or slender needles, which are inso-
luble in water, soluble in lead-salts and in ordinary strong nitric add, but not in Aiming
nitric acid.

Chelidonate of Magnesium, — ^Efflorescent needles, obtained by neutralising the
hot aqueous acid with carbonate of magnesium.

Chelidonates of Potassium. — The tripotasaio salt is deposited in yellow crvs-
tals from a solution of the dipotassic salt mixed with caustic potash. It has no alkaline
reaction when pure, but absorbs carbonic acid from the air, and is converted into the
colourless dipotassic salt. Boiled with excess of caustic potash, it yields oxalate of
potassium.

The dipotassic salt is obtained by decomposing the dicalcic salt with carbonate of
potassium.

A chelidoneUe ofealeium and potassium, CHKCa'O', is obtained by mixing a con-
centrated solution of the dicalcic salt with an equivalent quantity of carbonate of po-
tauBJum, In a very dilute solution, the Ume is immediately precipitated as carbonate.

Chelidonates of Silver. — ^The triar^entie salt, C'HAgK)*, is obtained b^ precipi-
tating the tricalcic or the dicalcic salt, mixed with ammonia, with nitrate of silver. It
is a yeUow very unstableprecipitate.

The dMfrgentio salt, CH'AgK)', is produced by dissolving oxide of silver in cheli-
donic acid, or by precipitating the dicalcic salt with nitrate of silver and heating to
the boiling Dointl It then separates on cooling in lon^ colourless needles resemlmng
acetate of suver. It is permanent in the air at ordinary temperatures, and is not
altered between 100^ and 200^ 0. ; decomposes with slight detonation between 140^
and 150^. It dissolves in water, ammonia, and strong nitric acid, but not in aloohoL

ChtUdoncLte of silver and calcium, C^HOaAgO*, is obtained by mixing a concentrated
ammoniacal solution of the dicalde salt with a concentrated solution of nitrate of silver,
as a light yellow precipitate, which alters but little in drying, and is decomposed by
water only after long continued boiling.

Chelidonates of Sodium. — ^The trisodic salt has not been obtained in definite
form.

The disodic salt, C'H*Na*0* + 4aq., is prepared by decomposing the dicalcic salt
with carbonate of sodium ; care must be taken not to add too large an excess of the
latter, which would give rise to the simultaneous formation of trisodic chelidonate, and
a trimetallic salt containing both calcium and sodium, a reaction which is immediately
indicated by the yellow colouring of the liquid.

The disodic salt is veiy soluble in water both hot and cold, and is difficult to crys-
tallise. Bv slow evaporation, however, small prismatic neediles are obtained, which
effloresce slowlj when elposed to air. They contain 21*16 per cent water of crystal-
lisation, of which 16'6 per cent goes off, at 100^ C, the rest between 160^ and 160^.

The monosodie salt, G'H'NaO* + 2aq., is obtained in slender needles by treating the
disodic salt with chelidonic acid.

The disodic salt treated with boiling hydrochloric acid, yields slender needles or
scales, which appear to consist of an a^ salt^ G'H'NaO*.C'HK)*+ 3aq.

Chelidonate of Strontium. — Slender needles obtained by dissolving the carbo*
nate in chelidonic<acid.

Chelidonate of Zinc. — Obtained by saturating the acid with oxide of zinc; it is
crystalline, and has an acid teaction.

CBBKZBOWZVB. C^H'^NK)' (?) (Godefroy, J. Pharm. Dec 1824; Probst,
Ann. Ch.Pharm. xxix. 123; Bealing, ibid. 131; Will, ibid. xxxv. 113; Gerh. iv.
210.)— An alkaloid contained in all fwrts of the Chelidonium majus, espedally in the

Vol. I. 81'

850 CHELIDONINIC ACID — CHEMICAL AFFINITY.

root It is obtamed by exfaaiutuig the root with water acidulated with Balphmie
acid, precipitating by ammonia, disrolTing the precipitate in alcohol acidulated with
sulphuric acid, reprecipitating by ammonia, and treating the residue with ether,
which dissolyes chelerythrine (saneuinarine) and leaves chelidonine. To purify this
product, it is dissolved in the smaUest possible quantity of water acidulated with sul-
phuric acid ; the solution is mixed with twice its volume of strong hydrochloric acid,
which, after a while, throws down a granular precipitate of hydiochlorate of dielidonine ;
the precipitate is digested with ammoniacal water, which sets the chelidonine at libertr ;
and the base thus obtained is crystallised from strong alcohol — or better from acetic acid.

Chelidonine crystallises in small colourless tablets, insoluble in water, soluble in
alcohol and ether. It melts at 130^ C. to a colourless oil, and decomposes at a higher
temperature. The crystals contain 2 at crystallisation-water, which escapes entirely at
100^ G. According to Will's analyses, the base dried at 100^ contains 67'4 to 68*1 per
cent C, 6-6 hydroffen, and 12-2 nitrogen; the formula C**H**N*0* requires 68*8 C,
5-4 H, 12*1 N, and 137 0. Water of crystallisation, by analysis, 46*6 to 6*13; by cal-
culation 4-91.

Chelidonine dissolves readily in acids, forming salts which hare a bitter taste and
redden litmus. Its compounds with the weaker acids, such as the acetate, are decom-
posed by evaporation. Ammonia added to solutions of the salts throws down a bulky
curdy precipitate, which after a while contracts into a granular crystalline mass. Tho
salts are likewise precipitated by tincture of galls.

According to Probst^ solutions of chelidonine are not poisonous.

HydrochloraU of cheUdonine is crystallisable, and dissolves in 325 pts. of water at
18° C. The ehloroplatinate, C^H^N'O'.HCLPtCP, is a flocculent, afterwards granular
precipitate, yielding by analysis 17*42 and 17*60 per cent platinum, the formula re-
quiring 17'77.

The nitrate is sparingly soluble in water ; the sulphate and phosphate are very soluble
both in water and in alcohol : all three salts are crystallisable.

The acetate is obtained by decomposing the sulphate with acetate of barium : it is
very soluble in water and alcohol, and dries up to a gummy mass.

CBHblBOVZiriO A.om. C'HiK)«? (Zwenger, Ann. Ch. Pharm. cziv. 350).
— ^This is another acid contained in very small (quantity in Chelidanium mqfus. When
the decoction of the plant acidulated with acetic acid, is treated with neutral acetate
[or nitrate] of lead, chelidonic acid is precipitated, and chelidoninic acid remains in
solution ; and by treating the filtrate with basic acetate of lead, not in excess, decom-
posing the precipitate with sulphuretted hjrdrogen, evaporating the filtrate, extracting
with ether, and again evaporating, chelidoninic acid is obtained in hard, mammellated,
yellow crystals. It dissolves easily in water, alcohol, and ether, and separates from
the aqueous solution in hard, white, anhydrous crystals, having the form of an oblique
rhomboi'dal prism. It has a strongly acid taste, decomposes carbonates, and dissolves
iron, with evolution of hydrogen. It melts at 195° C. ; its vapour is extremely irri-
tating. With nitrate of silver, it forms a white, crystalline, sparingly soluble preci-
pitate. Nitrio acid converts the acid into oxalic acid. Zwenger assigns to crystallised
chelidoninic acid the formula C?"ir"0"; it may perhaps be C^*IP*0**.HO, or
20'H"0«H«0.

A yellow bitter substance contained in the root, leaves,
and flowers of Chelidoniwm maitts. It is obtained by precipitating the juice with sub-
acetate of lead, decomposing the precipitate with sulphuretted hydrogen, and exhaust-
ing the sulphide of lead with boiling water. It crystallises in confused needles, but
more firequentlj forms a yellow friable mass. It is sparingly soluble in cold, moderately
soluble in boiling water. The solutions are yellow and very bitter, and are not altered
either by acids or by alkalis. (Probst, loc. cit.)

CKBMZCA& ATnMXTT. Chefmcal Attraction, Chemical Force, Ekctive At'
traction. Elective Affinity; Chemische Kraft, Verwandtsehaft, Wahlvertoandtschaft,
Wahlanziehung;Affinitas,Attractio EUctiva; Affinitl,^AM.mtj is that power by virtue
of which bodies of dissimilar nature unite t(^ther to form compounds of definite con-
stitution, which cannot be destroyed by mechanical agencies, and are, for the most
part, dissimilar in properties to the elements from which they are produced. Whether
this force is of peculiar nature, distinct from all others, or only a modification of the
power which, under various circumstances, shows itself as light heat, electricity, mag-
netism, mechanical force, &c., is a question still undecided. That it is intimately re-
lated to heat and electricity, is manifest from the whole range of chemical phenomense ;
indeed no chemical change can take place without a corresponding alteration in the tem-
perature and electrical state of the bodies concerned. The conclusion to which the pro-
gress of discovery appears to tend, is that chemical action, heat, electricity, and all
other manifestations of force result from certain movements in the ultimate particles of
lK)dies, and are accordingly convertible into the other. This idea will be further deve-

CHEMICAL AFFINITY. 851

loped in the articlefl Hbat, Lioht, and Elsctbicitt ; for the present, while we are
treating of phenomena purely chemical, it will be conyenient to speak of affinity as if it
were a distinct force.

The terms affinity and chemical combination are not nsed by all writers in exactly
the same sense. L. G-melin defines affinity' as " the power by virtue of which bodies
of disftimilar nature combine together into a whole, which appears perfectly uniform to
the senses, even when assisted by the most powerful instruments (Handbook^ i. 33).
Accordingly he applies it to mixtures of liquids, as of alcohol and water, alcohol and
Tolatile oils, &c., and to solutions of solids in liquids, as of salts in water, resins in
alcohol, &c, as well as to combinations in definite proportion. Most chemists, how-
eyer, make a distinction between mixtures and solutions on the one hand, and com-
pounds formed in definite proportions on the other, restricting the term " chemical
affinity " to the force, whatever it may be, that is concerned in the formation of the
latter. In favour of Cknelin's view, it may be alleged that mixtures of liquids and so-
lutions resemble chemical compounds, commonly so called, in these respects, that they
are perfectly uniform in colour, density, refractive power, and other physical characters,
and that the force which holds the heterogenous particles together m them is sufficient
to resist any tendency to separate arising from difference of density {e. g. a mixture of
water and alcohol, never separates into two layers, like oil and water), and can only be
overcome by the same means as ar^ applied to the destruction of the more intimate kind
of combinations, viz. heat^ or the superior affinity of another substance, as when resin
is precipitated from its solution in alcohol by addition of water, or carbonate of potas-
sium from its aqueovis solution by aloohoL

There are^ however, several well marked characters by which chemical combination
of the more intimate kind, such as that of oxygen and hydrogen in water, hydrogen
and nitrogen in ammonia, suldhur and mercuiy in cinnabar, &c., is distinguished from
mere murture or solution. These distinctions relate to the proportions in which the
constituents of the compound are united, to the character of the compound, and to the
drcumstanoes attending its formation and decomposition.

1. As regards proportion. Mixture and solution follow a law of continuity. Mis-
cible ]iqui£, such as alcohol and water, may be mixed in any proportions whatever,
and a solid dissolves in a liquid in aU proportions, up to a certain limit, the point of
saturation : but chemical combination, properly so called, takes place in certain definite
proportions and no others. Thus hydrogen and chlorine unite only in the ratio of I pt.
by weight of hydrogen to 35*5 pts. of chlorine ; oxygen and carbon, only in the ratio
of 6 pts. carbon to 8 and 16 pts. oxygen ; nitrogen and oxygen, as 14 pts. nitrogen to
8, 16, 24, 82 and 40 pts. oxygen; lead and oxygen as 103*5 lead to 8, 10|, and
16 pts. oxygen, mercury and sulphur as 100 mercury to 8 and 16 pts. sulphur, &c. &c.
In all cases, indeed, the number of compounds formed by any two elements is definite,
and combination never takes place in any intermediate proportions.

The law which regulates the proportions of the several compounds of the same two
bodies is called the *' Law of Multiples," and may be thus expressed : The several
proportions in which two bodies, A and B, unite, may be represented by the formuhe
A + B, A + 2B, A + 3B, . . . A + nB, or 2A + 3B, 2A + 6B, . . . 3A + 4B, ... or in
eeneral mA + nB ; where in and n are integer numbers in most cases not exceeding 7, at
least in inoiganic compounds.* We have seen in the article Atomic WsiaHTS (p. 452),
that it was the observation of these proportions which led Dalton to the idea of the
atomic theory. In short, if the ultimate atoms of the several elements be supposed to
possess certain invariable relative weights, and to unite and form chemical compounds
hy simple juxtaposition, in the proportion of 1 : 1, 1 : 2, 2 : 3, &c., the law just enun-
ciated follows as a matter of course. It is possible that the distinction between true
chemical combination and mixture may be found in this : that combination takes
place between ultimate atoms ; mixture between the physical molecules of bodies, which
are complex aggregates of atoms.

2. As to the character oftheproduot, — The properties of a mixed liquid, as the colour,
taste, specific gravity, refracting power, &&, are always intermediate between those of
its components. In solutions al^, the dissolved body imparts to the solvent its taste and
colour, m proportion to the quantity dissolved, the density of the solution also increasing
regularly and continuously with the amount of solid matter taken up ; but definite
chemical compounds generally differ altogether in physical properties from their com-

" The combining proportion! of the •lements of organic oomponndf are regulated bj much more
complex lawi* In the lerlet of fattjr acidt, for example, we find the same quantity of oxygm (8 pta.)
aatodated with 3, 9k8, 8x3, 4x9, 5x3, ... 80x3 part* of carbon ; and if, in addition to this, we con-
sider the rarloua proportions of C, H, N, and O, existing in the numerous series of organic bodies, it
mar fairly be concluded that the constitution of these bodies would never hare suggested the law of
multiples, as abore stated. Indeed, It is only by introducing the hypothesis of compound radicles, that
the composition of organic bodies can be assimilated to that of Inorganic compounds. (See Oroanio
Compounds and RAoicui.)

dl 2

862 CHEMICAL AFFINITY.

ponentfl. Thus, with regard to cclowr : yellow sulphur and grey mercury produce leA
cinnabar ; purple iodine and grey potassiom yield colourless iodide of potassium ;
purple iodine and grey lead form bright yellow iodide of lead ; the colours of metallic
oxides bear no relation whatever to uioee of the metals themselves, and the compounds
of metals with chlorine, iodine, and other salt-radicles, are for the most part trans-
parent, though the metals themselves are opaque. Again, we find organic compounds
exhibiting an endless variety of colours, formed by the union of elements which in the
free state have no colour at all. The deimty of a compound is very rardiy an exact
mean between that of its constituents, being generally higher and in a few cases lower;
and the taste, smell, refraetinff power, fusibility, volatility, conducting power for keat
and electricity, and other physical properties, are not for the most port such as would
result from mere mixture of their components. It must not of course be understood
that the physical properties of compounds are not related to those of their components
by any regular laws. Definite relations doubtless exist, and will one day be discovered :
indeed, the regular gradations of boiling point, atomic volume, &c., exhibited by the
terms of homologous series of organic compounds, afibrd striking examples of them ;
still it is generally true that the properties of a definite compound are not interme-
diate between those of its components, asnn a mixture or solution.

3. As to the phenomena which accompany the formation and decomposition of chemi-
cal compounds, especially as regards temperature. Chemical combination in definite
proportions, is always attended with evolution of heat, sometimes amounting to vivid
combustion, and decomposition is accompanied by absorption of heat and consequent
reduction of temperature ; whereas the mere mixing of liquids takes place without
change of temperature, and the solution of a solid in n liquid, though psrtaking of the
nature of comoination, is attended with reduction of temperature, due to the passage
of the body from the solid to the liquid state. So much Ib this the case, that a rise of
temperature attending the contact of a solid and a liquid, may always be regarded as
an indication of the formation of a definite compound ; thus there are many anhydrous
salts, such as chloride of calcium and sulphate of copper, which become strongly heated
by contact with water, being at the same time converted into hydrates ; but these
hydrates, in subsequently diraolving in the water, produce a considerable degree of cold.
(See Heat.)

The formation and resolution of chemical compounds are also attended with
changes in the electrical state of their elements. Whether the direct combination of
two elements produces an^ electrical disturbance, is not perhaps clearly made out, on
accoimt of peculiar difficulties in the investigation of the phenomena (see EuKnrBiciTT) ;
but the solution of a metal in an acid, which consists in the decomposition of one
compound and the formation of snother, calls into action a large amount of electric
force, which by certain airangements, hereafter to be considered, may be made to take
the form of an electric current. Conversely, an electric current, no matter how deve-
loped, whether by chemical action, or bv Mction, or by magnetic induction, is capable
of overcoming the most powerful chemical combinations, and causing the elements to
travel through the circuit in opposite directions, and finally separate at the poles of
the circuit. No such effect is, however, produced on mixtures or solutions. The
passage of an electric current through the solution of a salt, resolves that salt into
its elements, but never causes it to separate from the water as a whole.

For these reasons, we shall restrict the term Citbmiual Coxbhtation, to l^e forma-
tion of compounds in definite proportion, and Affintft, to the force which is concerned
in their production, and proceed to consider more paitlcularly the circumstances and
results of chemical combmation and decomposition.

. Eveiy elementary body is capable of uniting with others, and for the most part
with eveiy other. It is true that some of the compounds, as those of carbon with
certain metals,^ of boron with sUicon, selenium, and phosphorus, and of iodine with
carbon, have either not been formed or are but imperfectly known ; but there can be
little doubt of the possibility of their formation. The compounds of fiuorine with some
of the other non-metallic elements are least known, on account of the difficulty of
manipulating with fiuorine in the free state.

Compounds resulting from th# union of two simple substances, are called binary
compounds rf the first order; such are the metallic chlorides, oxides, and sulphides, the
chlorides of hydrogen, sulphur, phosphorus, &c. Now, these compounds are capable of
uniting with each other in various ways like elementaiy bodies, and hence result com-
pounds containing three or four elements, which may be regarded as binary compounds
of the second order; such are double chlorides, KCLPtCl* ; oxygen-salts, as Ba*O.SO' ;
sulphur-salts K*S.As'S*; hydrated chlorides CaC1.3H*0, &c, and again these com-
pounds of the second order may be conceived as uniting together to form compounds of
the third order, such as double salts, e, g. common alum, which contains sulphate of
potassium and sulphate of aluminium, KH).SO«-«- A1^0*8S0*. Further than this, the
^wer of combination does not appear to extend.

CHEMICAL AFFINITY. 853

This Tiew of the successiye building up of chemical oompoandfl in binaiy groups,
called the Dtudistio Uteory is, however, not the only one that can be taken, or ind^
that which accords best with the present state of knowledge. It is for many reasons
better to regard all compounds, whether containing two, three, or more elements, as
constituted according to certain typical forms ; for example, chlorides, iodides, bro-
mides, and cyanides, as formed on the type of hydrochloric acid HCl ; acids, bases,
and salts containing oxygen or sulphur, seleniumn or tellurium, as formed on the
type of water HH.O, &c. This is called the Unitary Theory. (See CLAssiFicATioir,
kIdiolbs, SuBsmuTiON, Tttbs, and the various articles in which particular com-
pounds are described.) It is true, indeed, that compounds containing three or more
elements may, in many instances, be formed by the oireet imion of binary compounds
of the first order; thus double chlorides and iodides are formed by fiising together the
component simple chlorides, or by mixing their aqueous solutions and leaving them to
crystallise ; sulphur-salts, such as Na^.A^', by fusing together the simple sulphides ;
03^gen-Balts also, in some instances, by heating toother the so-called anhydrous
acid and the base; thus boric anhydride and magnesia f^ised together in the proper
proportion form borate of magnesium, SMg'O.BK)* or Hg'BO' ; and anhydrous baryta
neated in vapour of sulphuric anhydride, bums and forms sulphate of barium, Ba^O.SO'
or Ba'SO*. But it by no means follows that the axiangement of the atoms in the resulting
compound must be the same as in the simpler compounds from which it is formed ;
thxu, while the mode of formation of sulphate of barium just mentioned would lead
to the supposition that it is BaK).SO*, other modes of formation, and most of its
reactions, indicate rather that its constitution is represented by the formula Ba*.SO* or
SO«.Ba«.0«.

These observations apply chiefly to inorganic compounds. Organic bodies, with
the exception of cyanogen and the hydrocarbons, all contain at leMt three elements,
and the duaUstic view of the building up of compounds by pairs cannot be applied
to them at all, excep^g on the supposition that thev contain certain compound
radicles, such as ethyls Cw, benzoyl, C?IL*0, &c., which play the same part as metids in
inorganic compounds, uniting like simple radicles, with oxygen, chlorine, bromine, &c.
With the help of these radidee, some of which have been obtained in the free state^
the constitution of the best known organic compounds, such as the alcohols, ethers,
aldehydes, acetones, and their derivatives, may be assimilated to that of inorganic
compounds, and represented either on the unitary or the duaUstic view.

Formation and Decomposition iff Chemieal Compounds.

As chemical combination involves a total change in the arraneement of the atoms of
the combining bodies, it is clear that cohesion, which tends to hold them in certain fixed
positions, must be opposed to chemical union, and on the contraiy, anything which gives
mobiU^ to the particleB of the two bodies, and enables them to intermix and approach
within small distances of each other, such as pulverisation, and more especially lique-
faction, must tend to promote it

a. Generally speaking, one at least of the oomhining bodies must be either in the liquid
or in the gaseous state, and if it be not so at ordinary temperatures, it must be brought
into that state by elevation of temperature. Solid bodies either do not combine at
all, or their combination is attended with great difiiculty, because, from the immobility
of their particles, their points of immediate contact are but few, and the exceedingly
thin film of compound which may be formed at such points, acts as a partition to pre-
vent fVirther contact and consequently further combination. But by continued rubbing,
which renews the points of contact, more complete combination may often be effected :
in this manner, finely divided copper may be made to combine with sulphur, the com-
bination being even attended witn rise of temperature. If, on the other hand, the
compound formed by the two solids is itself fiuid, its mobility gives rise to continu-
ally renewed contact, and combination goes on. Thus ice under 0^ C. unites with chlo-
ride of sodium and other salts, and solid amalgam of lead with solid amalgam of bismuth.
Crystallised oxalic add and lime may be made to combine by rubbing them together,
because the add contains more wateur of crystallisation than the oxalate of (^dum
produced is able to take up : hence, at the beginning of the action, a little water is set
free and dissolves the oxalic add. In some cases it is sufiSdent to heat one of the
solid bodies till it softens : thus iron surrounded with diarcoal and heated to white-
ness is dowly penetrated by the charcoal (Cementation), When, in consequence of one
or both bodies being in the fiuid state, combination takes place at the ordinary tempera-
ture or a little above it, it is called solution in the wet way (Solutio via huTnida) : if a
higher temperature is required, the process is called solution in the dry way, fusion
(&lutio iria sicca, Co^fusio).

b. Even if one or both of the bodies be in the fluid state, a higher temperature i$
often necessary to effect the combination.

3i 3

854 CHEMICAL AFFINITY.

Melted sulphur will not combine with carbon ; the sulphur must be brought in the
state of yapour into contact with red-hot charcoal, although the elasticity of the Tapoor
might rather be expected to interfere with the combination. Neutral carbonate at
of sodium, in the efflorescent state absorbs carbonic acid very slowly at first, bat more
and more quickly as it gets heated by the absorption, and ultimately with great
violence. Charcoal requires to be heated before it will burn in oxygen gas, that i^
before it wiU combine with the oxygen. At ordinary temperature, oxygen may be
mixed with hydrosen and other inflammable gases without combining with them, bat
at a red heat, combination takes place immediately. In this case both bodies are fluid,
and we might expect that heat, by increasing their elasticity, would rather oppose than
favour the combination. The manner in which heat acts in such cases is not predselY
understood ; but its effect is probably due to the increased rapidity of movement which
it gives to the particles. (See Hb4T.)

c. In some cases, light has the same effect as an elevation of temperatoie ; thus
chlorine, under the influence of lights unites directly with hydrogen or carbonic oxideu

d. Eiectricity likewise favours the combination of many substances, espedallj of
gases, acting chiefly, perhaps, by elevation of temperature. In this manner the com-
bination of oxygen with hydrogen, carbonic oxide or carburetted hydrpgen, and of
chlorine with hydrogen, is easily brought about.

e. In some instances, the expannon of gaseous bodies favours their combination with
others. Phosphorus undergoes slow combustion in oxygen ^as, however low the tem-
perature may be, the action going on more quickly as the gas is more rarefied ; a mixture
of oxygen and non-inflammable phosphoretted hydrogen gases explodes on expansion.

f. Ae presence of a solid body, particularly a metal, having a great extent of
surface, likewise causes, sometimes at ordinary, sometimes at slightly elevated tem-
peratores, the combination of oxygen with inflammable gases and vapours, which
would otherwise take place only at a red heat. This property is most strikingly ex-
hibited by platinum ; the more flnely divided the platinum, the stronger is its action.
When the combination of oxygen with inflammable gases take place at its surfiaoe, the
heat developed raises its temperature and thereby increases its activity, till at length
the metal becomes red-hot and then sudden combination occurs. Platinum appears to
condense gases, particularly oxygen, on its surface, whereby the heterogenous atoms are
made to approach one another and combine. A similar power is possessed by chazooal
and other porous bodies (p. 761).

A body in the act of chemical combination often exhibits the power of inducing the
same kind of activity in another body and causing it to combine with a third body,
thereby forming a cofapound which, under the existing circumstances^ would not have
been formed without ike presence of the first body (Liebig, Ann. Ch. Pharm. -nrr
262). Nitrogen gas does not by itself combine with oxygen, even when heated ; but
if a mixture of nitrogen and hydrogen be set on fire, the hydrogen bums, producing
water, and a portion of the nitrogen combines at the same time with ojcf gen, producing
nitric acid. Pure copper does not dLssolve in dilute sulphuric acid, but when com-
bined with zinc and nickel (in German silver), metals which decompose acidulated
water, or when combined with three times its weight of zinc only, it dissolves com-
pletely together with the other metals. Platinum when alone does not dLssolve in
nitric aci^ but when alloyed with silver it becomes soluble in that add.

Chemical compounds may be formed, either by direct union of their elements, or by
substitution of one element for another in a compound previously existing.

Oxygen unites directly with most other elements, either at ordinary or at elevated
temperatures ; so likewise do sulphur, chlorine^ iodine, and bromine. Hydrogen unites
directly with oxygen and chlorine at elevated temperatures, with the latter also at
ordinary temperatures, under the infiuence of light ; nitrogen shows but little tendency
to unite directly with any other element ; phosphorus unites readily with oxysen,
chlorine, iodine, and bromine at ordinary temperatures ; with sulphur and selenium
with aid of a moderate heat. Carbon, at high temperatures, imites directly with
oxygen, sulphnr, and many metals, not with any other element Boron and sUicium
combine directly with oxygen at ordinary temperatures, if they are in a state of
minute division, more easily when heated ; with other elements they exhibit little or
no power of direct combination. Mttals unite directly with oxygen, sulphur, selenium,
chlorine, bromine, and iodine, sometimes at ordinary, sometimes at higher tempera-
tures ; in some instances also with phosphorus and with carbon. Alloys of definite
constitution are also frequently produced by melting different metals together, though
the greater number of such products are merely mixtures.

It has been already mentioned that compound bodies can unite with one another
directly, forming new bodies of more complex constitution. These combinations aro
sometimes very eneigetic, as that of anhydrous baryta heated in the vapour of sul-
phuric anhydride, which is a true case of combustion.

CHEMICAL AFFINITY. 855

*- Altogether, howeTdr, the cases in which compounds are formed by direct nnion of

^ elements is small compared with that in which new compounds result from the trans-

* formation of others previously existing. Such transformations may be e£fected in
various ways.

I. By heat, which may either expel one or more of the elements of the original com-
pound in the free state, leaving the rest in a new form of combination, or may cause
the whole of the elements to arrange themselves in the form of new compounds. —
1. Chlorate of potassium, KCIO*, exposed to a full red heat, ^ves off the whole of its
oxygen, and is converted into chloride of potassinm, KCL Similarly with other chlo-
rates, also with bromates and iodates. Many metallic oxides and sulphides, when
heated to redness, give off part of their oxygen or sulphur, and are reduced to lower
^ oxides or sulphides. — 2. Chlorate of potassium exposed to a degree of heat less than

sufBcient to expel the whole of the oxygen, is resolved into perchlorate and chloride

• of potassium: 3KC10* » KCl + 2£aO« + O. Nitrate of ammonium, NHINO*, is
'' resolved by heat into water, 2H'0, and nitrous oxide, N'O. To this head likewise
'* belong the numerous transformations of organic compounds, resulting from diy or
^ destructive distillation.

n. By dectricity, —The action of the electric current on chemical compounds, either
in the f\iised state or in solution, gives rise to an endless variety of new products. In
some instances, the elements of a compound are eliminated by electrolysis in the free
' state, as when water, hydrochloric acia, or certain metallic oxides, chlorides, or iodides

' are subjected to the action of the current ; frequently, however, the elements arrange

themselves in new combinations. We shall consider this subject more fully under
ELBCTRicmr ; at present we will merely mention the formation of peroxide of lead at
the positive pole, when a solution of nitrate or acetate of lead is electrolysed ; the evo-
lution of amenetted hydrogen in the electrolysis of aqueous arsenious acid ; and the
decompositions of acetic acid and other fatty acids, into alcohol-radicles, hydrocarbons
of the ethylene-series, carbonic anhydride, and hydrogen.

III. By the action of another substance, simple or compound,

a. The decomposing substance is an element (or a compound acting as such), and
takes the place of one element of the compound, which is thereby eliminated. This is
SiMFLB Substitution.

Zinc decomposes hydrochloric acid, HCl, forming ZnCl, and earoellin^ hydrogen.
Potassium decomposes water, HHO, expelling half tne hydrogen, ana forming hj^drate
of potassium, KHO. Chlorine decomposes bromide of silver, forming cmoride of
silver and eliminating bromine. Metals in numerous instances displace other metals
from solutions of their salts, e, g, iron decomposes nitrate of copper, forming nitrate of
iron and a deposit of copper. Silicic anhydride, SiC, decomposes carbonate of soda,
NaK).CO', expelling carlK>nic anhydride, and forming silicate of soda, Na'CSiO*,
though not exactly in the proportion here indicated. Boric anhydride, B'O', heated
with hydrate of barium expels 3 atoms of water, and forms borate of barium : B*0' +
3(H«0.Ba«0) - 3Ba'K).B«0« + 3HH).

h. The acting body sometimes enters into combination with both elements of the
compound, or with the compound as a whole.

Sulphide of carbon burnt in oxygen, produces sulphurous and carbonic anhydrides.
Hydrocarbons and organic compounds in general, yield by combustion, carbonic anhy-
dride and water. Chlorine converts metallic sulphides into chloride of sulphur and
metallic chlorides. Chlorine passed into water forms hydrochloric and hypochlorous
acids ; it decomposes metallic oxides in like manner, forming with mercuric oxide,
Hg 0, for example, chloride of mercury, 2HgCl, and hypochlorous anhydride, CIK).
Sometimes only one compound is formed : as when a metallic sulphide is heated in the
j air and converted into a sulphate : e.g, Cu*S + O^ » Cu'SO^ ; or again, when phos-

phoretted hydrogen, PH', is converted by combustion into phosphoric acid, PH*0\

c. The substance by which the compound AB is decomposed, is itself a compound
CD, and the transformation consists in an interchange of elements, whereby the two
new compounds AD and BC, are' produced. This is Doublb Deoomfosition. It is the
most freouent of all kinds of chemical action, and, as we shall presently explain, may
be regarded as typical of the rest Instances of it may be adduced without number,
such as the mutual decomposition of neutral salts, f . g, chloride of barium and sulphate
of copper ; nitrate of silver and chloride of sodium, &c. Also the decomposition of
metallic oxides by acids, resulting in the formation of chlorides, iodides, sulphides, 4^
and oxygen-salts : thus, with hydrochloric acid and oxide of copper:

Cu«0 + H«C1» « CuH:J1« + HK) ;

hydrochloric acid and hydrate of potassium :

KHO + Ha - ECl f HHO;
3i 4

856 CHEMICAL AFFINITY.

Bolplijclrie acid and oxide of lead :

H«S + Pb«0 « H»0 + Pb*8.
Sulphuric acid and protoxide of iron :

H«SO< + Fe«0 - Fe«SO* + H*0 ;
snlphnric add and sesqnioxide of iron :

3H«S0* + Fe<0» - Fe*(SO*)« + 8BP0.

Similarly when compound radidee are concerned, as in organic compounds: e^g. tbe
formation of water and chloride of ethyl by the mutual action of alcohol and hydro-
chloric acid :

of ethylsulphuric acid and water, from alcohol and sulphuric add :

C^S0.=jS0.-^|80..gi0;

of thiacetic add and phosphoric anhydride, firom acetic add and pentasulphide of
phosphorus :

fi(«^'0J0)+P«'-6(^|s)+PK)..

of ethylamine by the action of hydrate of potassium on cyanate of ethyl :

Cjanateof Hydrate Carbonate Ethyl,

ethyl. ofpotas- ofpous- amhie.

Slum. tiam.

In some cases, the decomposition of a compound, AB, is effected by the joint action
of two substances C, D, not previously combined ; as when an oxide, alumina, for ex-
ample, is decomposed by the joint action of chlorine and carbon at a red heat, yidding
a chloride and carbonic oxide :

A1*0« + Cl« + C« = 2A1«C1» + SCO.

Sometimefi, instead of the two new compounds AD, BO, being produced, only one
such compound, AD, is formed, the elements B 0 being either set free or entering into
other combinations. Thus when chloride of ammonium is decomposed by quick lime,
the products should be chloride of calcium and oxide of ammonium ; but the latter
is immediatdy resolved into ammonia and water :

2NH*C1 + CaK) - 20aa + (NH*)*0 [- 2NH» + H«0].

Aluminium and other sesquiatomic metals do not form carbonates : hence, when a
salt of aluminium is predpitated by an alkaline carbonate, the predpitate consists, not
of carbonate of aluminium, but of alumina (hydrated), while carbonic anhydride is set
firee *

2Al«a« + 3Na«C0« « 6Na01 + A1<0» + 800«.

Many peroxides heated with hydrochloric acid, yield water, a protochloride of the
meted, and free chlorine, the metal not forming a chloride analogous in composition to
the peroxide:

MnO + 2Ha - HK) + MnQ + CL

In many cases, one or both of the new products, AD, BO, enters into combination
with an undecomposed portion of one or both of the original compounds, the particular
products formed depending upon the proportion in which the original substances are
present, and on the circumstances of the experiment Thus, when sulphide of carbon
is decomposed by potash, the immediate products are sulphide of potassium and
carbonic anhydride ; but these unite with portions of the original substances, forming
carbonate and sulphocarbonate of potassium :

80S» + 8KK) « KK).CO« + 2(K«S.CS«).

Sulphide of antimonv fused with potash, yidds at first sulphide of potassium and oxide
of antimony ; but the final products are oxysulphide of antimony and sulphantimonite
of potassium :

8Sb«S« + 8K«0 « Sb«0*.Sb«S« + 3K?S.Sb«8«;

but when 4 at. trisulphide of antimony are fused with 7 at. potash, the products are
2 at sulphantimonite and 1 at add antimonite of potasdum :

4Sb«S« + 7K«0 c 2(3K?aSb«S«) + K«0.2Sb*0».

CHEMICAL AFFINITY. 857

It has already been stated that double decomj^sition may be viewed as a type of
chemical action in general ; in fact» all cases of smiple substitution, and even of the
direct union of two uements, or the separation of the elements of a binary compound,
may be viewed as double decompositions, provided we make certain suppositions re-
specting the constitution of elements in the free state.

There are many considerations which tend to show that the atoms of an elementary
body, or of a compound radide in the free state, are associated by pairs in a similar
manner to the heterogenous atoms of a binaiy compound ; that is to say, a molecule
of free hydrogen consists of HH, and a molecule of free ethyl of (>H*.G*H*, just as a
molecule of hydrochloric add consists of HCl, and a molecule of chloride of etliyl of
C'H^.Cl. In the voltaic circuity the metallic conductor exhibits in many respects the
same phenomena as the dectrolyte, both parts of the circuit becoming heated, and
both producing the same deflection of a magnetic needle placed near them : hence
it mav be inftned, that the metallic conductor consists of a series of similar partides
polarised in pairs, just as the dectrolyte consists of a series of heterogeneous partides
thus polarised. In a circuit composed of sine, platinum, and hydrodiloric add,

the dectrolyte may be regarded as consisting of CIH CIH CIH . • . and tho

metallic part of the drenit of ZnZn ZnZn ZnZn . . • PtPt PtPt . . . the entire
circuit being thus made up of atoms in opposite polar states. This, as will be more fully
explained in the artide Elbctbicitt, is the most satisfactory idea that can be given
of the phenomena of electro-chemical action.

But there are also considerations purdy chemical which tend to the same condusion.
Many instanflfm of chemical action are known, in which two atoms of an dementaiy
body or compound radide unite together at the moment of chemical change, just like
heterogeneous atoms.

Thus, when hydride of copper, Ca*H, is decomposed by hydrodiloric add, cuprous
chloride is formed, and a quanti^ of hydrogen evolved, equal to twice that which is
contained in the hydride itself:

Cu«H + Ha - Cu*Cl + HH.

This action is precisely analogous to that of hydrodiloric add on cuprous oxide :

Cu*0 + 2HCI - 2Cu«Cl + HH).

In the latter case, the hjdrogen separated firom the hydrodilorie add unites with oxy-
gen ; in the former, with hydrogeh. When solutions of sulphurous and sulphydric
adds are mixed, the whole of the sulphur is predpitated :

so« + 2m3 - 2H«o + as«,

the action being similar to that of sulphurous add on sdenhydric add :

SO* 4- 2H*Se » 2H*0 -i- aSe'.

In the one case^ a sulphide of sdenium is formed ; in the other, a sulphide of sulphur.
The pred|utation of iodine, which takes place on mixing hydriodic with iodic add,
aiToras a similar instance of the combination of homogenous atoms. The reduction of
certain metallic oxidea bv peroxide of hydrogen, is another striking example of this
kind of action. When oxide of silver is thrown into this liquid, water is formed ; the
sQver is reduced to the metallic state ; and a quantity of oxygen is evolved, equal to
twice that which is contained in the oxide of silver. It appears, indeed, as if atoms
could not exist in a state of isolation. An atom of an elementanr body must unite,
dther with an atom of another element, or with one of its own kind.

Similar phenomena are exhibited by the aloohol-radides : thus, when sino-ethyl and
iodide of methyl are heated together, double decompodtion takes place, the products
being iodide of zinc and methyl-ethyl :

C*H*.Zn + CH».I - Znl + CH«.(?H» ;

aod when dnc-ethyl is heated with iodide of ethyl, a predsdy similar action takes
place, but attended with formation of free ethyl :

C«H».Zn + C^M - Znl + C»H».C«H».

In the first case, the ethyl separated from the iodine unites with methyl separated from
the dno ; in the second, it unites with another atom of eth^L The idea of the duality
of the molecules of alcohol-radides in the free state, is likewise in accordance with
their observed boiling-points and vapour-densities. (See Aloohol-Badiclxs, p. 96.)

Further, dementary bodies frequentiy act upon others as if their atoms were asso-
ciated in binary groups. Thus chlorine acting upon potash forms two compounds,
chloride and hypochlorite of potasdum :

KKO + ClCl - CIK + CIKO ;

858 CHEMICAL AFFINITY.

just as chloride of cyanogen would form chloride and cyanate of potassium. The
quantity of chlorine which acts upon an atom of potash, is not 1 at. » 35*5, but
2 at. « 70. Similarly, when metallic sulphides oxidise in the air, both the metal and
the sulphur enter into combination with oxygen. Sulphur acting upon potash forms a
sulphide and a hyposulphite. Lastly, when zinc-eth^l is ex|^sed to the action of
chlorine, iodine^ &a, these elements unite separately with the zano and with the ethyl,
thus:

C«H»Zn + Cia - C»H»CI + ZnCL

From these considerations it appears that double decomposition, which is generallj
understood as an action between four elements or groups of elements, may likewise be
supposed to take place in cases where only. three elements or groups come into play.
In uke manner we may reg^urd as double decompositioiu even those reactions which
are commonly yiewed as the simple combination or separation of two elements, or as
the substitution of one element for another. Thus when potassium bums in chlorine
gas, the reaction may be supposed to take place between two atoms of chlorine and
two atoms of potassium :

KK + ClCl « KCl + Ka

Again, the decomposition of (^anide of mercury by heat may be represented thus :

CyHg,CyHg « CyCy + HgHg.

The simple replacement of one element by another may also be regarded as a double
decomposition, by supposing the formation of an intermediate compound. Thus the
action of zinc upon hydrochloric acid may be supposed to consist of two stages :

ZnZn + HOI » ZnH + ZnCl,
and ZnH + HCl » ZnCl + HH.

It is true that the formation of the intermediate compound, the hydride of zinc, can-
not be actually demonstrated in this case, because it is decomposed as fast as it is formed ;
but in other cases, the two stages of the action can be distinctly traced. Thus, it is
well known that hydrochloric acid does not dissolve copper ; but an alloy of zinc and
copper, Cu'Zn, dissolves in it readily, with evolution of hydrogen. Here it may be
supposed that the first products are chloride of zinc and hydride of copper, a known
compound :

Cu'^n + HCl « Cu»H + ZnCl;

and that the hydride is afterwards acted upon by the add in the manner already ex
plained. Again, when zinc and iodide of ethyl are heated together in a sealed tube,
iodide of zinc and zinc-ethyl are obtained, thus :

ZnZn + (C^»).I = Znl + Zn(C«H») ;

and the zinc-ethyl, when heated with excess of iodide of ethyl, yields iodide of zinc
and free ethyl (p. 867).

It thus appears that all well understood cases of chemical action may be referred to
one type, namely, that of an interchange of elements between two previously existing
compounds.

d. The transformation of a compound is brought about by a substance which either
remains unaltered, or at all events does not enter into combination with either of the
elements of the compoxmd. This obscure mode of action,*usually called CatalysiSt or
Contact-action, is chiefly observed in the transformations of organic compounds, such as
the conversion of sugar into alcohol and carbonic acid, and of alcohol into acetic acid
under the influence of yeast; of starch into dextrin and sugar by the action of diastase ;
the conversion of urea into carbonate of ammonium, by contact with animal mucus, &e.
The terms Catalysis and Contact-action explain notliing, but as mere names they
are sometimes convenient. Many decompositions formerly spoken of as catalytic, are
now regarded as double decompositions, dependent on the polarity of homogeneous
atoms (p. 8^7).

Magnitvde or Strength of Chemical Affinity.

That the power which causes bodies to unite is exerted with various degrees of
intensity, is evident from the whole range of chemical phenomena. Chlorine certainly
imites with hydrogen more readily than with nitrogen, and the elements of hydro-
chloric acid are held together with far greater force than those of chloride of nitrogen.
If zinc displaces copper from its solution in hydrochloric acid, and copper cannot dis-
place zinc from such a solution, we cannot resist the conclusion that the affinity of
zinc for chlorine in solution is greater than that of copper. But does this show that
the former of these affinities is intrinsically and under all circumstances greater than

CHEMICAL AFFINITY. 859

the latter ? or may not the relative solubilities of chloride of zinc and chloride of
copper, or the cohesion of the metals themselves, have something to do with the result?
Or to state the question generally, does each element possess for eyery other a dis-
tinct and specific afi^t^ or combining power, which is always the same, and liable
only to be modified in its results by the circumstances under which the bodies are
placed, — or is the afi&nity between each pair of elements itself a yariable quantity
dependent on pressure, temperature, solubility, volatility, the presence of other
bodies, &o, &e.? The older chemists answered the first part of this question in the
affirmative. When they found a body A expelHng another B from its union with G,
they concluded that C had for A a greater affinity than for B.

On this principle they formed what were called Tables or Columns of Affinity, of
which the following may be taken as specimens, the several substances in each being
disposed in the oraer of their supposed affinity for the body at the head of the
colunm:

Sulphur: O; K and the other alkali-metals; Zn; Fe; Sn; Cu; Q; H; C; Pb;
Bi; Sb; Hg; Ag; Pt; Cu*S; MoS; Au,

Sulphuric acid: Ba^; Sr«0; KK>; Na«0; Li«0 (?); Ca«0; Mg»0; PVO; NH»;
Fe«0; Zn«0; Ni«0: Co«0; CtfO; A1*0"; Fe*0».

Metals: 0; F; 01; Br; I; Se; P; H.

A veiy slight acquaintance with chemical phenomena is, however, sufficient to show
that these so-called Tables of Affinity are merely tables of the order of decomposition
under particular circumstances, and that the relative affinity of one body for two others
is liable to change from a great variety of circumstanees, sometimes even to be re-
versed. Thus, iron at a red heat decomposes vapour of water, abstracting the oxygen
and setting the hydrogen free, whence it might be inferred that the affinity of ozvgen
for iron is greater than for hydrogen ; but if hydrogen gas be passed over red-hot
oxide of iron, water is formed and iron set free, indicating an exactly opposite order
of affinities. In like manner, potassium heated in an atmosphere of carbonic anhydride,
becomes oxidised and sets carbon free ; and on the other hand, charcoal strongly
heated with potash, abstracts the oxygen and sets potassium free. Garbonic anhy-
dride precipitates silica from a solution of silicate of sodium, and on the other hand
silica heated with carbonate of sodium, forms silicate of sodium, and liberates carbonic
anhydride ; and similarly in numerous other cases.

We must then look to other circumstances besides intrinsic force of affinity to de-
termine whether a pftrticular reaction will take place or not The most important
of these circumstances are :

1. The elasticity or the cohesion of one of the resulting compounds, and its con-
sequent tendency to assume the gaseous or solid state, and thus to remove itself from
the sphere of action.

^ The examples just mentioned affi}rd striking illustrations of the influence of vola-
tility in determining chemical decomposition. The tendency of the resulting gas or
vapour to diffiise itself through the surrounding atmosphere, doubtless contributes
greatly to the result ; thus, when a^ueoas vapour is passed over red-hot iron, the hy-
drogen set fr«e by the decomposition of the water is carried forward by the current
of aqueous vapour, and the iron is left free to act upon a fresh portion. The influence
of cohesion is clearly seen in precipitations. It is, indeed, a general law that if the
solutions of two salts are mixed, and an insoluble compound can be formed trora any of
their elements, that compound is sore to be produced and to separate firom the liquid.
Hence the order of decomposition is frequently reversed by the nature of the solvent.
Aqueous acetic acid decomposes carbonate of potassium, eliminating carbonic acid;
but if the resulting acetate of potassium be dissolved in alcohol, and carbonic acid
gas passed through the solution, carbonate of potassium is precipitated and acetic acid
passes into solution as acetic ether. A strong solution of caustic potash decomposes
carbonate of calcium, forming carbonate of potassium, and leaving lime undissolved ;
but a solution of I pt carbonate of potassium in 10 pts. of water, is decomposed by-
agitation with lime, yielding caustic potash and carbonate of calcium. A weak
solution of sulphurous acid dissolves iodine, forming hydriodic and sulphuric acids,
H^BO* + P + H?0 » 2HI + H«S0*; but if the quantity of water in the solution be
diminished by evaporation, sulphurous anhydride is evolved and hydriodic acid con-
taioinff iodine remains behind, W80* + 2HI » P + SO* + 2HK).

2. The relative quantities of the acting substances. — That the relativp degrees
of affinity of a body for a number of others to which it is simultaneously presented
are greatljr modifled by their relative masses, was first pointed out by JBerthollet.
The law laid down by that philosopher respecting the action of masses, is this : — A
body^ to which two different substances capcu)le of acting on it chcmicaUy, are presentid
in different proportions f divides itself between them in the ratio of the products of their

860

CHEMICAL AFFINITY.

respeelive moMUt, and the absolute etrengthe of their affiniUeafor the first body. Thna,
if we denote by A and B the masses of the two bodies which are present in excess, br
a and fi the coefficients of their absolute affinities for the body C; and by a and o
the qnantities of A and B which actually combine with C, the Uw just stated wiU be
expressed by the proportion :

$B.

If this Tiew be correct, any alteration, howeretr small, in the relative quantities of A
and B, must produce a corresponding alteration in the relatiTe quantities of the two
which unite with C. That this is not the case under all drenmstanoes, is shown bj
the following experiments of Bnnsen and of Debus.

Bunsen's experiments (Ann. Oh. Fharm. Ixxxr. 137), which were made in soeh ft
manner that all the phenomena of combination concerned in them took place simuUft-
neously, lead to the following remarkable laws :

1. wlien two or more bodies, BB' . . . are presented in excess to the body A^
under circumstances iayourable to their combination with it, the body A always selects
of the bodies BB^ . . . quantities which stand to one another in a simple atomic
relidion, so that for 1, 2, 3 . . . atoms of the one compound, there are always formed
1, 2, 3 . . . atoms of the other; and if in this manner there is formed an atom of the
compound AB',in. conjunction with an atom of AB, the mass of the body B may be
increased relatiyely to that of J^, up to a certain limits without producing any altera-
tion in the atomic proportion.

When carbonic oxide and hydrogen are exploded with a quantity of oxygen not
sufficient to bum them completely, uie oxygen divides itself between the two gases in
such a manner that the quantities of carbonic anhydride and water produced stand to
one another in a simple atomic proportion. The results of Bunsen*s experiments are
given in the following table, the numbers in which denote volumes :

Compoeitlon of Gaieouf Mixture.

Qoantitiet of CO and H coDtomed
by DetoMtlOD.

Ratio of
CO:IL

72-67 CO . 18-29 H . 914 0
69-93 „ . 26-71 „ . 1336 „
36-70 „ . 42-17 „ . 21-13 „
40-12 „ . 4716 „ . 12-73 „

1218 CO . 6-10 H

13-06 „ . 13-66 „

10-79 „ . 81-47 „

4-97 „ . ^0-49 „

2:1
1: 1
1:3
1 :4

The results were the same whether the explosion took place in the daark, in diffixsed
daylight, or in sunshine ; and were not affiscted by the pressure to which the gaseous
mixture, was subjected.

The proportions of hydrogen and carbonic oxide consumed in these several experi-
ments, correspond with the composition of five hydrates of carbonic anhydride, contain-
ing, respectively:

H»0.2C0«; H*O.CO«; 2HK),C0«; 8H«0,C0«; 4H«0.C0';

but the results cannot be attributed to the actual formation of these hydrates, inas-
much 08 hydrates of acids containing several atoms of water are incapable of ft-gi'«ri--mg
at high temperatures.

2. When a body^ A, exerts a redudny action on a compound, BG, present in excess,
so that A and B combine together and C is set free; then, if Ccan, in its turn, exert
a reducing action on the nkoly-forTned compound, AB, the final resuU of the action
is, that the reduced portion of BC is to the unreduced portion in a simple atondo
proportion.

In this case, also, the mass of the one constituent may, without altering the A-riatJng
atomic relation, be increased to a certain limit, above which, that relation undergoes
changes by definite steps, but always in the proportion of simple rational numbers.

When vapour of water is passed over red4iot charcoal, the carbon is oxidised and
hydrogen is separated; but the process does not go on so far as the complete formation
of carbonic annydride, but stops at the point at which 1 voL carbonic anhydride and

2 voL carbonic oxide are formol to every 4 voL of hydrogen.

In the imperfect combustion of cyanc^n — ^the gaseous mixture being so for diluted
that it will but just explode, in order that the temperature may not rise too high, and
the result' be consequently vitiated by the partial oxidation of the nitrogen — carbonic
anhydride and carbonic oxide are formec^ and nitrogen set free, likewise in simple
atomic proportion. A mixture of 18*06 voL cyanogen, 28*87 oxygen, and 63*08
nitrogen, gave, by detonation, 2 vol. carbonic oxide, and 4 voL carbome anhydride to

3 vol nitrogen.

CHEMICAL AFFINITY. 861

In the oombnstion of a mixture of carbonic anhydride, hydrogen, and oxygen, in
which the carbonic anhydride ia exposed at the same time to the r^ucing action of the
hydrogen and the oxidising action of the oxygen, the reduced portion of the carbonic
anhydride is likewise found to bear to the unreduced portion.a simple atomic relation.
In the combustion of a mixture of 8*52 carbonic anhyaride, 70*33 hydrogen, and 21*16
oxygen, the resulting carbonic oxide was to the reduced carbonic anhydride in the
ratio of 3 : 2. After the combustion of a mixture of 4*41 yoL carbomc oxide, 2*96
carbonic anhydride, 68*37 hydrogen, and 24* L 6 oxygen, the yolume of the carbonic
oxide oonyerted into carbonio anhydride by oxidation, was to that of the residual
carbomc oxide aa 1 : 8.

That these remarkable laws had not been preyiously obeeryed, is attributed by
Bunsen to the fact that they hold good only when the phenomena of combination,
which are regulated by them, take place simultaneously : for, eyen if a body A wem
originally to select for combination from the bodies JB and C, quantities bearing to
one another a simple atomic relation, but the combination of A uiaB were to take place
in a shorter time than that of A and C, it would follow of necessity, that during the
whole of the process, the ratio of Bto C, and therefore, also the atomic relations of
the associated compounds, would change, so that the obseryed {)ioportion would be no
longer definite. The same result must f oUow if the bodies which are combining side
by side are not homogeneously mixed in the beginnii^.

With regard to the bearing of these results on BerthoIlet*s law, it might be olgected
that, in some of the experiments, as in the combustion of a mixture of carbonic oxide,
hydroffen, and oxygen, one of the products, yiz. the water, is remoyed from the sphere
of action by condensation, and that the circumstances are therefore similar to the
remoyal of an insoluble product by precipitation. It is scarcely conoeiyable, howeyer,
that a reyerse action would take place, eyen if the jpaseous mixture were to remain
at the temperature whidi exists during the combustion. M oreoyer, in the decompo-
sition of yapour of water by red-hot charcoal, the whole of the products remain in the
gaseous state.

Debus ^Ann. Ch. Fharm. Ixxyx. 103; Ixxxyi. 156; IxTryji. 238), has obtained
results similar to those of Bunsen, by precipitating mixtures of lime and baryta- water
with aqueous carbonic add, or mixtiues of chloride of barium and chloride of cal-
cium with carbonate of sodium. A small quantity of a yery dilute solution of car-
bonate of sodium added to a liquid containing 6 pts. of chloride of barium' to 1 pt. of
chloride of calcium, threw down nearly pure carbonate of calcium ; but when the pro-
portion of the chloride of barium in the mixture was 6*7 times as great as that of the
chloride of calcium, 2*3 pts. of the former were decomposed to 1 pt. of the latter.
Hence it appears that, in this reaction also, limits exist at which the ratio of the
affinities undergoes a sudden change. In these experiments, howeyer, the products
are immediately remoyed from the sphere of action, and the results are ther^ore not
comparable wiui those which are obtained when all the substances present remain
mixed and free to act upon each other.

The latter condition is most completely ftdfilled in the mutual actions of liquid
compounds, such as solutions of salts, when all the possible products of their mutual
actions are likewise soluble; as, for example, when nitrate of sodium in solution is mixed
with sulphate of copper, llie question to be sdyed in such cases is this. Suppose two
salts AT^ CD, the e&ments of which can form only soluble products by their mutual
interchange, to be mixed together in solution. Will these elements, according to their
relatiye affinities, either remain in their original state of combination, as AB and CD,
or pass complete^ into the new arrangement AD and CB ? — or will each of the two
acios diyide itself between each of the two bases, producing the four compounds AB,
AD, BC, BD ? and, if so, in what manner will the relatiye quantities of these four
compounds be affected by the original quantities of the two salts ? Do the amounts of
AD and CB, produced hv the reaction, increase progressiyely with the regular increase
of AB, as required bjr Berthollet's theory ? or do sudden transitions occur, like those
obseryed in the experiments of Bunsen and Debus ?

The solution of this question is attended with considerable difficulty. For when two
salts in solution are mixed, and nothing separates out, it is W no means easy to as-
certain what changes may haye taken place in the liquid. The ordinary methods of
ascertaining the composition of the mixture, such as concentration, or precipitation by
reagents, are inadmissible, because any such treatment immediately^ altera the mutual
relation of the substances present In some cases, howeyer, the mixture of two salts
is attended with a decided change of colour, without an^ s^xaration of either of the
constituents, and such alterations of colour may afford indications of the changes which
take place in the arrangement of the molecules. This method has been employed by
Dr. Gladstone (Phil. Trans. 1866, 179; Chem.Soc Qu. J. ix. 64), who has carefully
examined the changes of colour attending the mixture of a groat yariety of salts, and

862

CHEMICAL AFFINITY.

Implied the resalto to the determination of the effect of mass in influencing chemical

Dr. Gladstone's principal experiments were made with the blood-red stdphocjanate
of iron, which is formed on adding snlphocyanic add or any soluble solphocyanato
to a solution of a ferric salt On mixing known quantities of different ferric salts with
known quantities of different snlphocyanates, it was found that the iron was ncTcr
completely converted into the rea salt; that the amount of it so converted depended
on the nature both of the add combined with the ferric oxide, and of the base com-
bined with the sulphocyanogen ; and that it mattered not how the bases and adds had
been combined previous to their mixture, so long as the same quantities were brought
together in solution. The effect of mass was tried by mixing equivalent proportions
of ferric salts and sulphocyanates, and then adding known amounts of one or the other
compound. It was found that in either case, the amount of the red salt was increased,
and in a regular progression according to the quantity added. When sulphocyanate
of potassium was mixed in various proportions with ferric nitrate, chloride, or sulphate,
the rate of variation appeared to be the same, but with hydrosulphocyanic add it was
different The deepest colour was produced when ferric nitrate was mixed with sulpho-
cyanate of potassium ; but even on mixing 1 at of the former with 3 at of the latter,
only 0*194 at of the red sulphocyanate of iron was formed; and even when 375 at
of sulphocyanate of potassium had been added, there was still a recognisable amount
of ferric nitrate undecompoeed. The results of a series of experiments with ferric
nitrate and sulphocyanate of potassium are given in the following table :

Ferric
KItrate.

SnlphocyikDtte of
Potattlam.

1
RiMlSalt
produced.

Ferric
Nitrate.

Sulphocyanate of
Fotaitlttxn.

Red Salt
produced.

1 equlr.
1 >•
1 »•
• i»
1 i»
1 ••

1 ft

5 ttODIS.

6 H

l«-6 „
16-2 ,.

i9-a „

46-8 „

137
156
176
195
813
966
318

1 atom.

• n

1 »»
1 n

63 atoms.

99 „
135 „
189 „
243 „
297 „
375 „

356
419
487
508
539
560
567

The addition of a colourless salt reduced the colour of a solution of ferric sulpho-
cyanate, the reduction increasing in a regularly progressive ratio, according to tho
mass of the colourless salt

Similar results were obtained with other ferric salts, viz. with the black gallate, the
Ted meconate and pyromeconate, the blue solution of Prussian blue in oxalic add, &c.,
and likewise with £he coloured salts of other metals, e. g. the scarlet bromide of gold,
the red iodide of platinum, the blue sulphate of copper, when treated with different
chlorides, &c

The amount of fluorescence exhibited bv a solution of add sulphate of quinine was
found to be affected by the mixture of a chloride, bromide, or iomde, according to the
nature and mass of the salt added ; and the addition of sulphuric^ phoaphoric, nitric,
and other adds was found to produce a fluorescence in solutions of hydrocfalorate of
quinine, or of sulphate which had been rendered non-fluorescent by the addition of hydro-
chloric add. Solutions of horse-chestnut bark, and of tincture of thorn-apple, yidded
similar results.

The oondusions to be drawn from GladstoneVi experiments, are as follows :

When two or more binary compounds are mixed under sudi circumstances that all
the resulting compounds are free to act and react ®^h add element enters into com-
bination with each basylous dement in certain constant proportions, which are inde-
pendent of the manner u which the different elements are primarily arranged, and are
not merely the resultant of the various strengths of affinity of the sevenu substances
for each other, but are dependent also on the mass of each of the substances present in
the mixture. All deductions respecting the arrangement of substances in solution,
drawn from such empirical rules as that the strongest add combines with the strongest
base, must therefore be looked upon as doubtfuL An alteration in the mass of any of
the binary compounds present, alters the amount of every one of the other binary
compounds, and that in a regularly pro^resnve ratio, sudden transitions occurring only
where a substance is present which is capable of combining with another in more
than one proportion. This equilibrium of affinities azranges itself in most cases in an
inappredablv short time ; but in certain instances, the elements do not attain their
final state ox combination for hours.

Totally different phenomena present themselves where precipitation, volatilisation,
crystallisation, and perhaps other actions occur, dmply be«iuse one of the substances

CHEMICAL AFFINITY. 863

18 thus lemoTed from the field of action, and the equilibrium, which was at first
eetablished, is thus destroyed.

The reciproeal action of salts in solution has also been examined by Mai a gut i
(Ann. Ch. Pbys. [31 zzzvii. 198 ; and bj Margueritte (Compt. rend, xzxriii. 306),
both of whom conclude that each base diyides itself between the sereral acids. Mala-
gttti concludes from his experiments that^ in the mutual action of two salts, if nothing
separates from the liquid, the decomposition is most complete when the strongest acid
and the strongest base are not originally united in the same salt, and that two experi-
ments of this kind, made in opposite ways, must lead to the same final result ; that,
for example, when 1 at. of acetate of barium is added to 1 at of nitrate of lead, the
quantities of nitrate of barium and nitrate of lead ultimately present in the liquid are
the same as when 1 at. nitrate of barium is mixed with 1 at. acetate of lead.

Hugneritte finds that two salts in solution decompose each other, eren when one of
them is already the least soluble of the four salts that may be produced from the acids
and bases present. Thus, a saturated solution of chlorate of potassium to which
chloride of sodium is added, becomes c^>able of dissolving an additional quantity of
chlorate of potassium, showing that a portion of the chlorate has been decomposed
and a more soluble salt fbrmed.

There are, however, certain well known phenomena, which show that this distri-
bution of adds and bases in solution does not always take place. Sorio acid colours
litmus wine-red; sulphuric acid turns it bright red. Now if sulphuric acid be gra-
dually added to a warm solution of borate of sodium in water which has been coloured
blue with litmufl^ the liquid at first remains blue, because a combination of soda with
excess of boric acid is ivoduced ; on the addition of more sulphuric acid, boric acid is
set free, and colours the liquid wine-red ; and not till all the soda has entered into
combination with the sulphuric acid does a Airther addition of that acid give the liquid
a bright red colour ; but if sulphuric add were present at the commencement of the
action, either in the free state or combined with sulphate of sodium in the form of an
acid salt, the bright red colour would appear at once. From the same cause, a solution
of sulphate ot potassium or sodium to which boric add has been added, colours litmus
only wine-red ; but the addition of ^^ of sulphuric add immediately produces the
bright red tint. Hence boric add does not take soda from sulphuric acid or set that
add free.— Sulphydric add and carbonic add exhibit similar relations towards sul-
phuric add. — ^Tmcture of litmus is instantly bleached by chlorine-water, but not till
after several days by aqueous solution of iodine : now, a solution of chloride of sodium
mixed with iodine should, according to Berthollet, produce a mixture containing
chloride of sodium with excess of chlorine, and iodide of sodium with excess of
iodine. But the orange-yellow mixture colours litmus preen (ftom the yellow of the
solution and the blue of the tincture) : and a very small quantity of cnlorine-water
immediatdy changes this preen colour into the orange-yellow of the solution of iodine:
this shows that no chlorme had been set free by the iodine. — ^Ferric phosphate is
soluble in hydrochloric add, but not in acetic add. From its solution in hydrochloric
add it is completely predpitated by acetate of potasnum. Now if the potash had
been divided between the hydrochloric and acetic acids, part of the hydrochloric add
would have remained free, and would have held some of the phosphate of iron in
solution. (Om. L 163.)

The decomposition of soluble by insoluble salts, aflbrds a striking instance of the
tendency of atoms to interchange, and of the influence of mass on chemical action.
According to EL Bos e (Fogg. Ann. xdv. 481 ; xcv. 96, 284), sulphate of barium is
completely decomposed by b^ing with solutions of alkaline carbonates, provided that
each atom of sulphate of barium is acted upon by at least 16 at oi the alkaline
carbonate. When 1 at of sulphate of barium is boiled with only 1 at. of carbonate of
potassium, only ) of it is decomposed, and only X by boiling with 1 at of carbonate
of sodium, further decomposition being prevented oy the presence of the alkaline sul-
phate already formed. If, however, the liquid be decanted after a while, the residue
boiled with a fresh portion of the alkaline carbonate, and these operations repeated
several times, complete decomposition is effected. Carbonate of barium is converted
into sulphate by the action of an aqueous solution of sulphate of potassium or sodium,
even at ordinary temperatures. Solution of carbonate of ammonium does not decom-
pose sulphate or barium either at ordinary or at higher temperatures ; carbonate of
barium is not decomposed by sulphate of ammonium at ordinary temperatures, but
easily on boiling. Sulphate of barium is not decomposed by boiling with caustic
potash-solution, provided the carbonic add of the air be exduded ; but by fusion with
liydrate of potassium it is decomposed, with formation of carbonate of barium, because
the carbonic acid of the air cannot then be completely excluded. Hydrochloric and
nitric acids, leftin contact at ordinary temperatures with sulphate of barium, either cits-
tallised or predpitated, dissolve only traces of it; at the boiling heat, a somewhat

864 CHEMICAL AFFINITY.

burger qnantihr is dissolyed, and the solatioii fonns a dond, both with a dilute solution
of chlonde of barium and with dilute snlphuric add. Sulphate of Btrontitun is dissolved
by hydrochloric acid at ordinaiy temperatures, saffidentiy to form a slight precipitate
with dilute solphnric add, and wita chloride of strontiimL Sulphate of caldrnn
treated with hydrochloric add, dther cold or boiling, yidds a liquid in which a preci-
pitate is formed, after a while, by dilute sulphuric add, but not by chloride of caldnm.

Sulphate of strontium and sulphate of calaum are oompletdy decomposed by solutions
of the neutral and add carbonates of the alkali*metals at ordinaiy temperatures, and
more quickly on boiling, eren if condderable quantities of an alkaline sulpnate are added
to the solution : the deoompodtion is also effected by carbonate of ammonia, even at
ordinary temperatures. The carbonates of strontium and caldumare not decomposed
by solutions of the sulphates of potasdum or sodium at any temperature; sulphate
of ammonium does not decompose them at ordioaiy temperatures, but readily wit& the
aid of heat.

Sulphate of lead is completely converted into carbonate by solutions of the neutral
and add carbonates of the alkidi-metals, even at ordinaiy temperatures, the neutral
carbonates, but not the add carbonates, then dissolving small quantities of oxide of
lead. Carbonate of lead is not decomposed by solutions of the alkaline sulphates^
dther at ordinary temperatures or on boiling.

Chromate of barium is decomposed at ordinary temperatures by solutions of the
neutral carbonates of the alkali-metals, and much more easily by boiling with ex-
cess of an add carbonate of alkali-metal. When equiTalent quantities of the chromate
of barium and carbonate of sodium are boiled wiu water, 1 of the whole is decom-
posed ; when the same quantities of the salts are fused togetner, and the mass treated
with water, only j^ of the barium-salt is decomposed. Carbonate of barium is com-
pletdy converted into chromate by digestion with the solution of an alkaline mono-
chromate ; and the decompodtion of chromate of barium by neutral alkaline carbonates,
even at the boiling heat, is completdy prevented by the presence of a certain quantity
of an alkaline monochromate.

Selenate of barium is easily and completely decomposed by solutions of alkaline
carbonates, even at ordinary temperatures: this salt is somewhat soluble in water, and
more readily in dilute adds.

Oxalate of caldum is decomposed by alkaline carbonates, even at ordinaiy tempe-
ratures; but to effect complete decompodtioo, the liquid must be frequently decanted
and renewed. The decomposition takes place rapidly at the boiling heat; but in all
cases it is completdy prevented by the presence of a certain quantity of a neutral
alkaline oxalate. When the salts are mixed in equivalent proportions, ^ of the oxalate
of calcium are decomposed at ordinaiy temperatures, and f on boiling. Carbonate of cal-
dum ia partially converted into oxalate by the action of a solution of neutral oxalate
of potawium at ordinary temperatures, and more quickly on boiling ; but the decom-
position is never complete, even when the liquid is frequently decanted and renewed.
— Oxalate of lead is completely converted into carbonate at ordinary temperatures by
the solution of an alkaline carbonate, a small portion of the carbonate of lead dissolving
in the liquid. (Bose.^

The preceding experiments exhibit in a remarkable manner the influence of difference
of solubility in determining the order of deoompodtion. Sulphate of barium is less
soluble thim the carbonate, and, accordingly, carbonate of banum is.more readily de-
composed by alkaline sulphates than the scuphate by alkaline carbonates. Precisdy the
contrary relations are exhibited by the sulphates and carbonates of strontium* and
caldum, both as regards solubility and order of decomposition. On the other hand,
oxalate of caldum is less soluble than the carbonate, and yet its deoompodtion by
alkaline carbonates takes place more easily than the opposite reaction ; in this case,
the order of decomposition appears rathex to be determined, as in Ma]aguti*s experi-
ments (p. 862), by the tendency of the strongest add to unite with the strongest base.

The ^ect of a soluble sulphate, &c in arresting the decomposition of the correspond-
ing insoluble salts by alkaline carbonates, is evidently due to its tendency to produce
the reverse action : hence the accderation produced by decanting and renewing the
liquid. Some insoluble salts, however, phosphate of calcium for example, are never com-
pletdy decomposed, even by this treatment (See also Malagu ti, Ann. Ch. Phys. [3]
li, 328*)

J%eories of Chemical Action,

Chemical combination was in early times attributed to the general prindple of
Hippocrates that "like assorts with Uke :**' hence the wcod Affinity, which seems to
have been first employed by Barchhusen. Becher assumed, in accordance with t^is
dogma, that when two bodies are capable of combining, tiiey must contain a common

• According to Fretonioi, carbonate of strontium dissoiret in I1,SG2 partu, and sulphate ofstroutiunt
in €896 paru of water. ^^

CHEMICAL AFFINITY. 865

I principle. Otiieis, among whom was Lemery, snpposed that solyents are furnished

I with a number of sharp points, hj means of whicn they are more or less adapted to

t insinuate themselves into the pores of solid bodies and combine with them.

Dismissing these crude notions, we hare to consider four distinct hypotheses which
hare been proposed to account for the phenomena of chemical action.

1. ChemiccU combinations are produced by universal a ttraetion.

Newton was the first who referred chemical combination to universal attraction,
though he did not regard the attraction between ultimate particles as exactly the
same with that which acts between the great bodies of the universe.

BerthoUet also regarded chemical combination as a manifestation of the force of
universal attraction, exhibiting peculiar characteristics, because it is exerted, not on
masses, but on molecules placed at extremely small distances from each other. Being
unacquainted with the laws of combination in definite proportions, he supposed that
bodies, by virtue of their affinity, are essentially capable of uniting in all proportions,
and attributed what he considered the apparent exceptions to the law, entirely to the
infiuence of cohesion and elasticity. That these causes exert considerable influence on
chemical combination, is sufficiently evident £rom the phenomena already discussed ;
but to suppose that combination in definite proportion is absolutely dependent upon
them, would be inconsistent with our present knowledge of the constitution of chemical
compounds ; indeed, the single fact that chlorine and hydrogen unite in one proportion
only, and form hydrochloric acid gas, without any conaensation or e^ansion, is quite
sufficient to show the untenability of such a supposition.

2. Chefmical combinoHona are produced by a peculiar power called Af/i nity^ distinct
from all others. This hypothesis may be reserved for discussion after it has been
shown that all the known powers of nature are insufficient to account for the pheno-
mena of chemical action.

3. 7%e union of heterogenous atoms is the result of Electrical attraction.
Numerous theories of this kind have been proposed, among others by Davy, Dumas,

Beoquerel, Ampere, Grotthuss, Schweigger, Fechner, Berzelius and L. Gmelin.

Bereelius supposed that " The atom of every substance has two poles, on which the
opposite electricities are accumulated in different proportions, according to the nature
of the bodies. The atom of many bodies, oxygen for instance, has a large quantity of
negative electricity attached to one of its poles, and but a very small quantity of
positive electricity at the other ; that of otner bodies, potassium for example, has a
large quantify of positive electricity at one pole, and a very little negative electricity
at the other. Thus the elementaiy substances are divided into eHectro-negatitfe and
electro-positive. To each element, however, there belongs a particular proportion be-
tween the quantities of the two electricities. Oxygen has, of all the electro-negative
elements, the greatest quantity of negative electricity at one of its poles, and the smallest
quantity of positive electricitv at the other, — then follows sulphur, then nitrogen, &c,
and lastly hydrogen, in which the quantities of the two electricities are nearljr equal.
Of all electro-positive substances, potassium has the largest quantity of positive and
the smallest of negative electricity ; and this inequality continually diminishes in
other bodies, till we come to gold, in which the positive electricity predominates but
little over the negative — so that this element occupies the next place to hydrogen.
According to this, the elements succeed one another in the electro-chemical series
of Berzelius as follows, beginning with the electro-negative.

" EUctro^negative, 0, S, N, F, CI, Br, I, Se, P, As, Cr, V, Mo, W, B, C, Sb, Te, Ta,
Ti, Si, H.

" Electro-positive^ Au, Os, Ir, Pt, Rh, Pd, Hg, Ag, Cu, U, Bi, Sn, Pb, Cd, Co, Ni, Fe^
Zn, Mn, Ce, Th, Zr, Al, Y, G, Mg, Ca, Sr, Ba, L, Na, K

" In the combination of an electro-negative with an electro-positive body, the predo-
minant negative electricity of the former unites with the pzedominant positive elec-
tricity of the latter. Before, however, combination takes place, the former substance
exhibits negative, and the latter positive electricity in the free state; and the tension
of the two electricities continually increases as the bodies approach the temperature
at which combination takes place. Hence we have an explanation of electricity by con^
tact. At the instant of combination, the negative poles of the atoms of the first body
turn themselves towards the positive poles of those of the second ; and since it is only
in the fiuid state that the atoms possess the mobility necessary for this arrangement^ it
follows that solid bodies have, generally speaking, no chemical action on one another.
The two electricities of these poles now combine and produce heat or fire, whereupon
they disappear. In every chemical combination, therefore, a neutralisation of the opposite
electricities takes place, by which heat or fire is produced in the same manner as in the
discharge of the electrical pile or of lightning, excepting that these last-mentioned
phenomena are not accompanied by any chemi^ combination, at least of ponderable

Vol. I. 3K

866 CHEMICAL AFFINITY.

bodies. Every chemical combination is therefore an electrical phenomenon depend-
ing on the electrical polarity of the atoms."

The main difficulty of this theory is to account for the force by which combined
atoms are held together. The heterogeneous atoms unit« in consequence of their
adhesion to Ihe opposite electricities ; but when these have been neutx^lised by c<Hn-
bination, it might be expected that the atoms would fall asunder and allow themselyes
to be easily separated by Mction and other mechanical forces, which is not the case.
This objection to the theory of Berzelius has never been satisfactorily answered.

Gmelin's theory is as follows: — "Ponderable bodies have affinity for one another.
The two electricities are substances which likewise possess affinity* for each other, and
by whose combination in the proportions in which they neutralise each other, heat
(fire) is produced. The individual electricities, and likewise heat, have considerable
affinity for ponderable substances, and are united to them with greater force and in
greater quantity, the more simple these ponderable substances are. Ponderable
bodies, according to their nature, have a greater or less excess of positive or negative
electricity united with them, in addition to a definite quantity of heat Thus, oxygen
probabW^ contains the greatest quantity of positive^ and potassium of negative electri-
city. Bodies lying between these two extremes, contain a larger quantity of heat with
a smaller excess of one or the other kind of electricity, the proportion of which varies
greatly according to their nature.

" The combination of two ponderable bodies is the result of two forces, viz. the
affinity of the ponderable boidies for each other, and the affinity of the electricity
which is in excess in the one body for the opposite electricity which predominates in
the other. By these two forces, the affinity of the electro-negative body for the
positive electricity united with it, and that of the electro-positive body for the negative
electricity combined with it, are overcome. The result is heat and the ponderable
compound. The latter retains the excess of positive or negative electricity, by whidi
it requires either an electro-negative or electixy positive chitfacter, and likewise part of
the heat — while another portion is set free^ and gives rise to the development of heat
or fire, by which most chemical combinations are accompanied. When oombiiiation
takes place between two bodies, both of which contain an excess of the same kind
of electricity, «.^. oxj^gen and sulphur, which contain free positive electricity in
different quantities,— it is simplest to suppose that the combination is the lesolt
merelv of the affinity between the two ponderable bodies, that the new compound
contams the sum of the excesses of positive electricity, and that the development of
heat is a consequence of the inability of the new compound to retain as much heat
united with it as was before combined with its constituents.*' (G m. L 154 — 15S.)

4. Chemical action results from a constant motion among the ultimate particles of
bodies, this same moffement likewise giving rise to the phenomena of heat, l*ght^
and eleetrieity. This is the theory suggested by Williamson (Ohem. Soc Qn. J.
vi. 110). The atoms of all compounds, whether similar or dissimilar, are supposed to
be oontinuallv changing places, the interchange taking place more quickly as the
atoms resemble each other more closely. Thus, in a mass of hydrochloric acid, each
atom of h^rdrogen is supposed, not to remain quietly in juxtaposition with the atom of
chlorine with which it happens to be first united, but to be continually changing places
with other atoms of hydrogen, or, what comes to the same thing, continually becoming
associated with other atoms of chlorine. This interchange is not perceptible to the
eye, because one molecule of hydrochloric acid is exactly fike another. But suppose
the hydrochloric acid to be mixed with a solution of sulphate of copper (the com-
ponent atoms of which are likewise undergoing a chanse of place): the basylous
elements, hydrogen and copper, then no longer limit their &ange of place to the circle
of atoms with which they were at first combined, but the hydrogen and copper likewise
change places with each other, forming chloride of copper and sidphuric acid. Thus
it is thi^ when two salts are mixed in solution, and nothing separates out in conse-
quence of their mutual action, the bases are divided between the acids, and four salts
are produced. I^ however, the analogous elements of the two compounds are very
dinimilar, and, consequently, interchange but slowly, it may happen that the stronger
acid and the^ stronger base remain almost entarely t<^ther, leaving the weaker ones
combined with each otiier. This is strikingly seen in a mixture of sulphuric acid
(sulphate of hydrogen) and borate of sodium, which soon becomes almost wholly eon-
verted into sulphate of sodium and free boracic add (borate of h^rdrogen).

Now, suppose that^ instead of sulphate of copper, sulphate of silver is added to the
hydrochloric acid. At the first moment, the interchange of elements may be supposed
to take place as above, and the four compounds, H*SO\ Ag%0\ HGl, and AgOl, to
be formed ;^ but the last being insoluble, is immediately removed by precipitation ;
the remaining elements then act upon each other in the 'faame way, and this action
goes on till all the chlorine or all the silver is removed in the form of chloride

CHENOCHOLIC ACID — CHENOPODIUM. 867

of silTer; if the original oomponnds are mixed in exactly equiralent proportions,
the final result ia the formation of only two salts, vie in this case, H*SO^ and AgCL
A similap result is produced when one of the products of the decomposition is volatile
at the existing temperature, as when hydrate or carbonate of sodium is boiled with
chloride of ammonium.

If no precipitation or volatilisation takes place, and one of the compounds (hydro-
chloric acid) is in excess of the other (sulphate of copper), then, as the atoms of
copper in their several interchanges must come in contact with chlorine-atoms more
frequently than with 80^-atoms, the final result must be the formation of a larger
quantity of chloride of copper and of sulphate of hydrogen than if the bodies had been
mixed in equivalent proportions, this effect of course increasing as the relative quantity
of hydrochloric acid is greater in the original mixture; and thus we have an explana-
tion of the effect of mass in chemical reaction.

The same theory affords an easy explanation of certain chemical changes otherwise
somewhat . obscure. Consider, for example, the formation of ether by the action of
sulphuric acid upon alcohol, whereby ethyl-sulphuric add (sulphate of ethvl and
hydrogen) is first formed, and afterwards, at a certain temperature, ether and water

are eliminated (p. 76). When alcohol, h i^> '^^ sulphuric add, §[S0^ are

mixed together, the interchange between the atoms of ethyl in the former and of
hydrogen in the latter gives rise to the formation of ethyl-sulphuric add and water :

But the change does not stop here : for the ethyl-sulphuric add thus produced, meeting
with firesh molecules of alcohol, exchanges its ethyl for the hydrogen of the alcohol
producing ether and sulphuric add :

The sulphuric add is thus restored to its (»nginal state, and is ready to act upon fresh
quantities of alcohol ; so that if alcohol be allowed to run into the mixture in a con-
stant stream, the temperature being kept within certain limits (between 130° and
140° C), the process goes on without interruption, ether and water continually distil
over,- and the same quantity of sulphuric add suffices for the etherificatlon of an un-
limited quantity of aicohoL This is the peculiarity of the process ; it has given rise
to a variety of explanations, all more or less unsatisfiictory, the discussion of which
would be foreign to the present purpose ; it is sufficient to remark that' the hypothesis
of atomic int^hange affords a ready explanation of the chief peculiaritv of the re-
action, vis. the foitnation and decomposition of ethyl-sulphuric add following each
other continuously, without any change of temperature or other determining cause.
If it be admitted that the atoms of ethyl and hydrogen in the mixture are continually
interchanging in all posdblo ways, this series of alternate actions follows as a neces-
sary consequence.

The idea of atomic motion is in accordance with physical as well as chemical phe-
nomena. To suppose that rest, rather than motion, is the normal state of the partides
of matter, is at variance with all that we know of the effects of light, heat, and elec-
tridty. In the theory of heat, the partides of bodies are supposed to be affected with
progressive, as well as with rottitoiy and vibratory movements ; and this same h^rpo-
thesis of progresnve movement, which of course implies change of relative position
amongst the partides, affords, as already stated, an easy explanation of certain chemical
reactions otherwise difficult to understand.

cnmoOHOUW AOUK CH^O^.— An add obtained by boiling tauro*
chenochoUc add, the sulphuretted add of goose-bile, with baryta-water, and decom-
posing the resulting banum-salt with hydrochloric add. It ia insoluble in water, but
soluble in alcohol and ether, whence it separates as an amorphous mass. The solutions
have an acid reaction, and give the characteristic blood-red colour with sugar and
sulphuric add. It is insoluble in cold potash, but when heated with it, forms a salt
which, when freed fix>m excess of potash, dissolves readilyin water and in alcohol.
The ^rttfm-salt consists of C"H*'BaO\ (Heintc and Wislicenus, Pogg. Ann.
cviiii. 647.)

OMavoCM^VBOUCn. An impure iron sinter, containing a little silver and
arsenate of cobalt It is a product of decomposition, not a distinct mineraL

CaonrOFOBIUll. The herb of Chenopodium ambrosiaides jidds by distillation,
a pure greenish-yellow volatile oil (about l| oa. from 10 lb.) having an aromatic and

8k 2

868

CHERT— CHIASTOLITE.

cooling taste (H. Becker, Zeitschr. Pharm. 1854, p. 8). According to Hirzel (ibiiL^
this oil, dehydrated by chloride of calcium und rectified, yields a colourless distillate
boilingat 1790tol8loC. •

Chenupodium mariHmum. — The ash of this plant, growing on a strip of land re-
claimed from the sea, has been analysed by Harms {Aim. Ch. Pharm. xdy. 247) with
the following results : a. Flowers and young shoots, b. Stems.

KH) NaK) Ca*0 Mg*0 Fe*0«
4-4 2-3 4-2 6-6 4-3
3-1 50 4-4 20 2-5

co»

SO*

SiO*

Naa

0-9

2-4

71-9

100

0-8

2-0

76-9

100

Traces of manganese were also found. The flowers and young shoots are said to yield
31*9 per cent, ash, and tiie stems 24*3 per cent This, together with the veij large
proportion of chloride of sodium in the ash, seems to show that the plants analysed
were saturated with salt water. Aster tripolium grown on the same soil, likewise
yielded a very large amount of ash, containing about 65 per cent NaCl in the stem
and leaves, and 30 per cent in the flowers.

Chtnopodium olidum. — This plant contains an alkaloid hayinff the composition
C*H'N, either trimethylamine or propylamine, to which its foetid odour appears to be
due. (Dessaignes, Compt rend. xTxiii. 358.)

Chenopodium Quinoa. — According to Volcker (Chem. Gaz. 1851, p. 129) qninoa
seeds dned at 100^ C. contain 46*10 per cent starch, 6*10 sugar and extractiye matter,
4*60 gum, 5*74 oil, 8*91 casein with a little soluble albumin, 13*95 insoluble albumin
and other albuminoidal compounds, 9*53 yegetable flbre, 5*05 ash. The aah (after
deduction of sand and charcoal) contained 36*76 per cent potash, 1*31 chloride of
sodium, 2*45 lime, 13*61 magnesia, 1*78 ferric oxide, 38*99 phosphoric anhydride, 3*36
sulphuric anhydride, and 2*19 silica.

CBBBT. A term often applied to homstone and to any impure flinty rock, in-
cluding the jaspers. (See Ur/s JHcHonary qf ArU^ Manvfaotwre* and Mines, L 655.)

CMMBBYZJTM or OKBSST OOFVmU Syn. with Azusitb. (See Casbok^tbs
07 COFPBS, p. 784.)

See EiLfiPAB.

OBBSTJi UT« Castanea vesea, — The fruit of this plant has been examined by
Payen (J. Pharm. [3] xvi 279) and by Albini (Wien.Akad. Ber. xiii. 502). Payen
found in 100 pts. :

Of the cultivated chestnut . .
Of the wild chestnut . . .

Water.

Ath

In dry
Substance.

Nltrogm.

In fresh
Substance.

In dry
Subetaace.

1
After
deducting
Ash.

54*21

4806

4*04
3*21

0*53
0*50

1*17
0*96

1*21
0-99

Albini found in the shelled kernels of dried chestnuts from various parts of Italy :
3*0—3*3 per cent ash, 1*2— 21 fat, 23*2— 380 starch, 22-8— 23*3 dextrin, 17-5— 17'9
sugar, 6*5 — 8*4 cellulose, 0*9 — 2*1 vegetable albumin, and 5*2 — 5*3 so-called protein-
compounds.

According to Dessaignes (J. Pharm. [3] xxv. 28), chestnuts contain a little aspar-
agine, but no querdte.

The entire fruit of the tree (undried) yields 0*99 per cent ash, containing in 100 pts.
39*36 K«0, 1918 NaK), 7*84 Ca«0, 7'84 Mg*0, 5*48 Mn*0» [?J, 3*88 S0«, 232 SiO«,
7*33 PK)*, 1*9 phosphates of calcium, magnesia, and iron, 4*82 Nad (T. Bichard-
son, Jahresber. d. Chem. i. 1074.)

Hollow Spar. MacU. Al*0«.SiO«.— A variety of Andalusite
crystallised in right rhombic prisms with angles of 91° 35' and 88° 27'. On looking
into the end of the prism, we perceive in the axis of it a blackish prism, surrounded
by the other, which is of a gre^sh, yellowish, or reddish-white colour. From each angle
of the interior prism, a blackish line extends to the corresponding angle of the exterior.
In each of these outer angles there is usually a small rhomboidal space, filled with the
same dark substance which composes the central prism. The black matter is the same
day-slate with the rock in which the chiastolite is imbedded. Fracture, foliated, with
double cleavage. Translucent Scratches glass. Rubbed on sealing-wax it imparts
ne^tive electricity. Specific gravity 2*94. Hardness 3—7*5. Before the blowpipe
it is convertible iuto a whitish enamel It has been found in Britany, in the Pjrrenees,

CHICA— CHmOLINE. 869

in the Tslley of Bar^e, and in Galicia in Spain, near St. lago de Compostella. Tho
interior black crystal ie properly an elongated four-sided pyramid. U.

OBZCA. A red dye, obtained from the leayes of Bignonia Chica, (See Cabajubu
p. 747.)

OMKEtDMMM ITll* A phosphate of aluminium and iron (ferrosum) found with
apatite at Tayistock in DeTonshire, and at Crinnis in ComwalL Bammelsbeig found
in two specimens :

P»0» A1K)« Fe«0 Mn'O CaH) Mg*0 HH) Total
L . . 29-36 18-77 80-76 6-12 0*66 — 17-00 102*66

n. . . 28-92 14*44 30-68 907 — 014 1698 100-23

(after deducting 3*82 per cent of insoluble residue in L and 4*03 in II.)

From the analysis XL, which was made with purer material than L, Bammelsberg
deduces the formula : 2(4MK).P«0») + 2Al*0«.P»q» + 16H0, which may be reduced to
that of an orthophosphate with hydrate of aluminium and water, yiz. j (MW)iP*0^\
SalHO + 6aq. The crystals belong to the trimetric system : P . JP. 3f oo JPoo . oop
and OP.' CleaTace parallel to P and oot*ao (Brooke, Ramm elsberg). Specific grayity
« 3*247. Hardness a 6 (Bamm elsberg). The crystals, which are transparent,
have a glassy lustre, and yary in colour firom yellowish-brown to blackish, are found
on the surface of spathic iron ore inteigrown with quarts, iron pyrites, and copper
pyrites. (Brooke, Ann. PhiL yii 316. — Bammelsberg, Pogg. Ixzxr. 436 ; PhiL Mag.
[4] iv. 118.)

Syn. with QdTHiTB.

Syn. with Prehnttb.

ro&ZSa. OH'K. Quinoleinef Leucol (Bunge, Pogg. Ann. zxxi. 68.^
Gerhardt, Ann. Ch. Pharm. xlii 310; zliy. 279. — Hofmann, t^. zlvi. 31; liii.
427; budy. 16. — Bromeis, ilnd, lii. 130. — ^Laurent, Ann. Ch. Phys. [3] xix. 367.
— C. Greyille Williams, Ed. Phil. Trans, xxi [2] ; [3] 877; Jahresber. d. Chem.
1866, p. 648; 1866, p. 632.— y. Babo, J. pr. Chem. IxxiL 73.— Gm. xiii. 243).—
Bunge, in 1839, obtained from coal-tar an organic base to which he gaye the name of
iettcol, Gerhardt, in 1842, obtained a similar product, quinoldney by distOling quinine
and other organic bases with potash. Hofmann showed that Gerhardf s quinoleine
and Bunge's leucol were identicaL Laurent first pointed out that C^erhardt's quino-
leine was a mixture, a fiact afterwards established by Gr. Williams, who separated
pure chinoline from it, as well as from the mixture of bases obtained from coal-tar.
According to later experiments by Williams, howeyer, the chinoline from coal-tar
appears to differ in some respects from that which is obtained from cinchonine, &c.
Williams has also succeeded m preparing from chinoline (obtained from cinchonine),
a fine blue colouring matter likely to be useful in dyeing.

Formation, — Chinoline is produced in numerous reactions : — 1. In the dry distilla-
tion of coal, passing oyer with the tar (Bunge). — 2. By distilling cinchonine, ouinine,
or strychnine with hydrate of potassium (Gerhardt). — 3. By the electrolysLB of
nitrate of cinchonine (y. Babo). — 4. By distilling thialdine with milk of lime
( Wohler and Lie big, Ann, Ch. Pharm. Ixi y/) — 6. By the dry distillation of tri-
genic acid or trigenate of silyer (Liebig and Wohler, ibid. lix. 289). — 6. By dis-
tilling berberine with mUk of lime, or hydrate of lead (Bodeker, Ann. Ch. Pharm.
Ixix. 43). Bodeker also states that chromate of peloeine heated to 100^ C. giyes off a
mixture of chinoline and phenic add; but according to Williams (Jahresber. d.
Chem. 1848. p. 376), the only yolatile products of this decomposition are methylamine,
dimethylamine, and a pyrrol-base. Williams is of opinion that the production of
chinoline in some of the aboye reactions has been inferred merely from its odour,
when, in reality, not a trace of it has been present.

Preparation. — 1. P^m Cinchonine, Pulyerised cinchonine is gradually added to
hydrate of potassium, which is heated in a retort till it melts ; the mixture is then raised
to a higher temperature till it becomes brown and emits stifling yapours (Gerhardt);
and the distillate, which is a mixture of seyeral bases, is boiled with an add for
seyeral days, whereby pyrrhol is driyen off The dry chinoline which afterwards
distils oyer, beginning to boil at 149® C, but not passing oyer in large quantities till
the boiling point rises to 183®, is separated by repeated fractional dutillation (about
200 timesj into seyeral portions, the lowest of which boils between 164® and 160®,
and the highest, which is the largest in quantity, at 271®. Of these fractions, that
which distils below 166® contains lutidine, with a little pyridine and piooline; that
between 177® and 182® contains oollidine, which is also found in the products up to
199®; and the portion which distils aboye 199®, especially that between 216® and
243®, consists of cliinoline and lepidine, the latter being found chiefly in the portion

3k 3

870 CHINOLINE,

boiling aboTe 270°. To obtain chinoline (and the other baaes) perfectly jnir^ the
individual fractions are conyerted into platinum-salts, and separated by fractional
crystallisation. (Williams.)

2. From Coal-tar Oil. — a. The mixture of phenylamine and chinoline (leaool),
obtained from heay^ ooal-tar oil (see PHSNTLAicmB), is dissolyed in absolute alcohol,
and neutralised with oxalic add; and the motheivliquor decanted from the oxalate
of phenylamine which has crystallis<A out» is distilled with potash, the receiver being
changed as soon as the distillate no longer produces a blue colour with hypochlorita
of calcium, and the chinoline which afterwards passes over is collected apart (Hof-
mann). Chinoline thus obtained, contaius lepidine and other bases (Williams). —
b. Fifty gallons of the oil of \reiY high boilins point, and heavier than water, are treated
with sulphuric acid, and the acid liquid is distilled with lime. The portion of the dis-
tillate which sinks in water, contains chinoline, lepidine^ &c., together with a number
of bases of the phenylamine series. The latter are decomposed with nitrite of potas-
sium and hydrochloric acid (see Phbhtlajcimb) ; the acid liquid is distilled from tiis
heavy oil containing phenic acid ; the admixed non-basic oils are expelled by passing
steam through the Uquid ; the residue is filtered through charcoal ; and the bases ai«
separated from the aqueous solution by potash, and dried over sticks of solid potash.
The mixture thus obtained yields, after more than a hundred fractional distillations,
portions boiling between 177^ and 274°, and from these the chinoline is separated by
fractional crystallisation of the platinum-salts, as above. (Williams.)

Properties. — Chinoline is a transparent, colouriess, strongly refracting, mobile oil,
which neither thickens or freezes at — 20° C. (Ho fmann, 6r omeis). Specific gravity
1-081 at 10° (Hofmann). It conducts electricity less readily than phenj^mine
( H o f m a n n ), boils steadily at 238° C. and distils without alteration (Will i a m s) : it
eyaporates even at ordinary temperatures, so that the oil-stain whidi it produces on
paper soon disappears. The yapour-density of chinoline boiling between 238° and
243° C. is 4*519 (Williams). Chinoline has a penetrating odour, like that of phos-
phorus and of hydrocyanic add (Bunge), of ot, Ignatius' bean (Gerhardt), of
bitter-almond oil (Hofmann). It does not apptor to be poisonous (Gerhardt).
The aqueous solution kills leeches, but when introduced into tiie stomach of a rabbit,
produces only transient convulsive symptoms and prostration of strength. It is
alkaline to litmus and turmeric (Gerhardt, Bromeis); only to dahlia-paper
(Hofmann).

Several formulse have been proposed far diinoline. According to the analyses of
Hofmann and Bromeis (made on chinoline containing lepidine, according to Williams),
it is C»H»N ; Gerhardt at first regarded it as C«H»'NO, afterwards (TraiU, iv. 449) as
C'^H'N. The formula C*H^N, first suggested by Laurent^ is confirmed by WiUiams's
analyses of several of the salts ; the puro base does not appear to have been analysed.
The formula C'H'N gives for the yapour-density, calculated to two volumes, the number
4*47 which agrees veiy nearly with Williams's determination.

Chinoline is veiy sparingly soluble in cold water, rather more in hot toaier and is
extracted from the solution by ether (Hofmann). When shaken up with water at
0° C. it forms a dear oil containing 2C*H^.3H*0, which at 16° C. gives up water and
becomes turbid. When chinoline saturated with water at 0°C. is heated to 100°, water
and a litUe chinoline escape, and a dear hydrate remains, containing 2CH*^N.H'0,
which remains limpid and mobile at — 20°, but is resolved by distillation into water and
anhydrous chinoline. (Bromeis.)

Chinoline mixes in all proportions with ndj^hide of carbon, alcohol, ether, wood-
tnjirit, aldehyde^ and acetone ; it also mixes with oHe, both fixed and volatile. It
oLBSolveB phosphorus, sulphur^ and arsenic, also common can^hor and colophony, but
not copal or caoutchouc It does not coagulate albumin.

Decompositions. — 1. Chinoline when set on fire, bums with a luminous but smoky
fiame. — 2. It becomes resinised by exposure to the air. — 3. Chlorine instantly changes it
into a blf ck resin, with great tibq of temp^fature and evolution of hydrochloric add
(Hofmann^, into a yellow oil, which is decomposed by water, leaving a white
insoluble substance (Williams). — 4. With bromine, it forms a similar resin (Hof-
mann).— 6. Aqueous chinoline treated with a mixture of hydrochloric add and
chlorate of potassium rapidly becomes covered with a layer of orange-red oil, which
solidifies to a toush mass on cooling (Hofmann). — 6. Fuming niiric add acts
violently on chinoline, and converts it into a splendid mass of ctystals, but does not
form any products of decomposition (Gr. Williams). — 7. Chmoline immediately
takes fire m contact with dry chrojnic add, and is resinised by aqueous chromic add
(Hofmann). — 8. Permanganate of potassium deoompoaes dunoline into oxalic add
and ammonia Hofmann). --^ Potassium dissolves in chinoline, with evolution of hy-
drogen, but without colouring. On melting potassium in chinoline vapour, cyanide of
potassium is formed. ChinoBne vapour pawed over buri^t tartar, remains for the most

CHINOLINE. 871

part unchanged, bnt fonnfi a small quantity of cyanide of potassium (Hofmann). —
10. Chinoline passed over red-hot quick lime (Hofmann), or sodaAime (Bromeis),
suffers little or no decomposition. — 11. Enclosed in a sealed tube with iodide of methyl^
and heated for ten minutes to 100^ C, it is changed into cnrstals of hydriodate of methyl*
chinoline. In like manner, it is conyerted by iodide of ethyl into hydriodate of ethyl-
chinoline, and by iodide of amylvoto hydriodate of amvl-chinoline (Williams). —
12. Chinoline becomes wwm when mixea with auivhide o/m^Mv/ (sometimes disengag-
ing vapour of methylic ether and methylic alcohol), and forms, if complete combination
has been promoted by heat, a liquid soluble in water, which, when excess of sulphate
of methyl is present^ deposits separate crystals. The liquid is rendered turbid by
potash or ba^rta, and separates oil-drops, which at first become red, then green,
finally yiolet, and when heated pass into a beautiful violet resiii, metJ^lirisine, with
formation of sharp, strongly smelfing, condensable yapours. At the same time a brown
resin and a sulphomethylate are formed. ChinoUne, heated to boiling with etdphate
of ethyly forms a colourless liquid, which, when boiled with strong caustic potash, de-
posits a yiolet resin, ethylirieine^ insoluble in ether, and a brown resin soluble in ether,
while an ethylsulphat« remains dissolved, and a sharp neutral oil, sinking in water,
passes over, which, if immediately mixed with dichloride of platinum, yiel& beautiM
needles, but soon decomposes (v. Babo). — 13. Chloride of acetyl acts violenUy on
chinoline, forming a cmtalline very deHc^uesoent mass ^Williams). — 14. With
eyanate of ethyl, it solidifies into a czystallme mass consisting of phenyl- ehinyl-car-
bamide, N«(CO)''.C^».C»H*.H«.

CHmouirB Saxts. — Chinoline unites with acids, forming salts which crystallise
easily (Williams). It precipitates salts of aluminium and ferricum, and renders
lead-salts and ferrous salts sli^tly turbid (Hofmann). Aooording to Gerhardt, it
precipitates nitrate of silver, but not ferric nitrate.

Chmoline salts are decomposed by fixed alkalis ; also by ammonia at a moderate
heat ; but at high tem|)eratiures, chinoline expels ammonia. i>ry chinoline-salts tresited
with phenylamine, emit the odour of chinoline. (Hofmann.)

Chlorhydrate or Hydroehlorate of Chinoline, — Chinoline absorbs hydro-
chloric acid gas violently, and with evolution of heat, and solidifies on ooc^inff to
white crystals, which take up more hydrochloric acid, becoming red and Uquid, and on
again cooling, solidify to a deliquescent, slightly crystalline mass. Hence diinoline
appears to form both a neutral and an acid hydroehlorate (Bromeis). When hydro-
chloric acid gas is passed over chinoline dissolved in ether, the hydroehlorate separates
in heavy viscous drops, which after a while become slightly crystalline (Hofmann).
Mixed with solutions of metallic chlorides, it forms double salts, which for the most
part crystallise readily.

Chlorantimonite, — Chinoline forms with trichloride of antimony a whit«precipitate,
which dissolves in boiling bydrochloric acid, and crystallises on cooling (Biofmann).

Chloro-aurate. C'H'K.HCl.AuCl'. — Delicate canary-yellow needles^ permanent in
the air, sparingly soluble in water, and containing, when dried at 100<^C. 41*85 per
cent of gold ; the formula requires 42*0 per cent. (Wil liam s.)

Chlorocadmate. C»H^.HCl.PtCl'. —The concentrated solutions of hydroehlorate of
chinoline and chloride of cadmium solidify to a pulp when mixed : the dilute solutions
yield white permanent needles, which give off 2 at. water at 100° C, volatilise com-
pletely at a higher temperature, and are sparingly soluble in alcohol. (Williams.)

Chloromercurate. C*H'N.2HgCl. — ^White precipitate, which is not decomposed by
boiling water (Hofmann), and separates on cooling in beautifol pearly plates
fBromeis). It smells of cninoline, and has a very bitter, disagreeably metallic taste.
According to Hofinann*s analysis, it contains 26*5 per cent. C, 17*6 CI, and 49*9 Hg,
the formula requiring27*0 C, 1776 CI, and 60*0 Hg.

Chhropalladtte. OTE'N.Ha.PdCJl.— Chestnut-brown crystals, containing 20*96 per
cent. Pd ; by calculation 21*18 per cent. (Williams.^

Chloroplatinate, C'H'N.HClJ^tCl*.— Yellow crystalline precipitate, which dissolves
in 893 pts. of water at 16° C. (Williams). The salt obtained by fhictional crystal-
lisation, fourteen times repeated, firom a portion of the bases (preparod from cinchonine,
p. 869), boiling between 238° and 243<Vyielded 32*36 per cent C, 2*74 H, and 29*29
Pt, the formula requiring 32*06 C, 2*68 H, and 29*19 Cl. (Williams.)

Chlorostanniie. — Hydroehlorate of chinoline forms with protochloride of tin, a yel-
low, heavy oil, which afterwards becomes crystalline, and dissolves with difficulty in
alcohol. (H o f m a n n^

Chloro-uranate, C*H'N.HC1.(XT'0)C1. — Concentrated solutions of ammonio-chloride
of uranyl and hydroehlorate of chinoline, solidify when mixed : dilute solutions yield
beautifU yellow prisms, containing (at 100° C.) 31*87 per cent C, 2*77 H, and 20*97 Cl,
the formula requiring 3206 C, 2*37 H, and 21*07 CL (Williams.)

8k 4

872 CHINOLINE-

Chromate of Chinoline. — Chzomie acid forma a j^How crystaDine parecipitste
with chifloline (Gerhardt, Hofmann). Dilute chromic acid added in exceoa to
aqueouB chinoline (obtained from cinchonine), throws down a small quantity of resinous
matter, which becomes crystalline when rubbed with a glass rod, diasolyee in boiling
water after filtering and washing, and is deposited in brilliant needles on cooling. It
detonates when heated, but Dot after addition of hydrochloric add. The crystals gaT«
by analysis, 45*08 per cent. C, 3-49 H, and 22*34 Cr, agreeing rery nearly with the
formula 2C*H^N.H*0.2CrH)' (Williams). Chinoline from coal-tar did not yield a
ciTStallised compound with chromic acid, but only oily drops, eren when the impurities
which could be oestroyed by chromic acid had been remored. (Williams.) j

Niirate of Chinoline. — Solution of chinoline in excess of nitric add, lesrea when ]

eyaporated over the water-bath, a pasty mass, which solidifies on cooling, and when
crystallised from hot alcohol, forms white needles, permanent in the air, infbszble at i

100" C, and consisting of CH'N.HNO' (Williams). Easily soluble in water and ''

alcohol, insoluble in ether. (Hofmann.)

Oxalate of Chinoline, is a confused, radiating, unetaous mass, eadly soluble in
water, alcohol, and ether (H o f m a n n). An acid oxcSiUe, G*H^.CH*0^, is obtained on
mixing a solution of 16*5 pts. oxalic add in a small quantity of water with 243 pta.
of chinoline, as a soft, white, crystalline mass, which when recrystallised from alcohol,
forms slender needles haying a silky lustre. It decomposes at 100^ C, with CTohition
of chinoUne. (Williams.)

When chinoline containing phenylamine is dlssolyed in alcohol or ether, and mixed
with alcoholic oxalic acid, almost all the oxalate of phenylamine is deposited alter a
few hours, while oxalate of chinoline remains in solution. (Hofmann.)

Pierate of Chinoline resemUes picrate of phenylamine. (Hofmann.)

Sulphate of Chinoline. — Crystallisable and deliquescent. (Gerhardt and
Hofmann.)

Tannate of Chinoline. — Chinoline forms with inftision of galls, a yellowish-brown
pedpitate (Hofmann) ; a white flocculent predpitate, 8olub& in b<nling water and
in alcohoL (Gerhardt)

Stthetitution-Derivaiives of Chinoline.

Mbthtl-ohiholihb, C"H»N=N.H.CH».C»H». ^Gr. Williams, EdPhil. Trans,
xxi. [3] 577.) — Not known in the free state, at least in definite form. The hydmodate is
obtained in fine crystals, by heating chinoline and iodide of methj^l together to 100^ C.
in a sealed tube for ten minutes. It is decomposed by oxide of silyer, forming iodide
of silyer, and an unstable, strongly alkaline solution, which when heated with potash
emits a tfuffbcating odour, probably arising from methylamine. The plaiinum-saltf
C"*H*N.HCl.PtCl*, is obtained as a sparingly soluble salt, by decomposing the solution
of the hydriodate with nitrate of silyer, predpitating the excess of silyer with hydro-
ehloric acid, and adding dichloride of platinum to the filtrate.

Ethtl-chinolinb, C»»H"N = N.H.C«H*.C»H». (Gr. Williams, loe. cit)

Chinoline treated with iodide of ethyl, as in the preparation of hydrioKlate of
methvlchinoline, yields, after distilling off the excess of iodide of ethyl, crystals of
hydnodate of ethylchinoline. On treatmg these crystals with oxide of suyer and water
(if this is done in the water-bath, a yolatile product escapes which attadcs the eyes),
and filtering off the iodide of silyer, a colourless, strongly alkaline solution of ethyl-
chinoline is obtained, which decomposes on eyaporation in the water-bath, assuming a
carmine colour, and on the edges emerald-green, afterwards changing to a beautiM
blue. It espels ammonia from sal-ammoniac. It predpitates chloride of mercury and
the salts of lead, iron, and copper.

Hydriodate of Eiht/lchinoline, C"H"N.HI, forms cubes when recrystallised from al-
cohol It is more soluble in water than in alcohol. It giyes by analysisi 46*5 per cent. C,
4*4 H, and 44*1 1, the formula requiring 46*3 C, 4*9 H, and 44*6 L

At 100^ C, it becomes transiently blood-red. It iB decomposed by sulphate of silyer,
forming iodide of silyer, and a liquid which is colourless at firsts but on eyaporation
oyer the water-bath, assumes a carmine colour, dark blue at the edges, and wnen dry
leayes a blackish-red mass haying a coppery lustre. The mass forms with water a
dark carmine solution, which is coloured scarlet by hydrochloric and nitric acids, and
rose-red by ammonia : with potash, itforms ayiolet precipitate which is but sparingly
soluble in water, but dissolyes in alcohol, forming a carmine-rod solution. Dichlonde
of platinum produces in the hydrochloric acid solution of the precipitate, a bulky,
insoluble double salt^ of a higher atomic weight than the platinum -salt of hydrochlorate
of ethylchinoline.

Platinum-ealt of Ethylchinoline. C"H"N.HClJPtCl.— Golden-yellow, sparingly so-
luble predpitate.

CmOLITE. 873

Respecting v. Babo*8 componndfl, methyU and ethyl-irinney which Rppear to be iso-
meric with methjl- and ethyl-chinoline, see p. 870 ; also the names of the substances
themselves.

Amti-ohinolikb, C"H»TT= N.H.C*H".C»H» ((Jp. Williams, he, eit.)—A
mixture of chinoline and iodide of amyl heated in a sealed tube for several hours to
lOO*' C, deposits beautiful crystals of the hydriodate, C**H"N.HL The platinum-
foltf C**H*'N.HCLPtCl*, is sparingly soluble in water, insoluble in ether-alcohoL

Hydriodate of amyl-chinoline heated with alkaUs, yields a fine blue colour, which
may be used as a dye. To prepare it» 1 pt by weight of crude chinoline is to be boiled
for ten minutes wit n 1| pts. of iodide of amyL The mixture, from being straw-coloured
becomes deep reddish>l^wn, and solidifies on cooling to a mass of aystals. This
product of the reaction is to be boiled for about ten minutes with 6 pts. of water, and,
when dissolved, filtered through paper. The filtered liquid is to be gently boiled in
an enamelled iron pan over a small fire, and exceess of ammonia ^adually added.
The ebullition may he prolonged with advantage for one hour, the evaporation of the
liquid being compensated for by the gradual addition of weak solution of ammonia,
prepared by the admixture of ecjual volumes of ammonia of the density of 0*880 and
distilled water. The hour having elapsed, the whole is allowed to cool, when the
colour will almost entirely have precipitated, leaving the supernatant liquid nearly
colourless. On pourinff tiie fluid away^ (preferably t&ough a filter, in order to retain
floating particles of colour^ the dish will be found to contain resinous looking masses
which dissolve readily in alcohol, yielding a rich puiplish-blue solution, which may be
flltered and kept for use.

The colour prepared as above is of a purplish tint, but if a purer blue be required
the following modification is to be resorted to. The filtered aqueous solution of hy-
driodate of amyl-diinoline, is, as before, to be brought to the boiHng temperature ; but
instead of addins ammonia, a solution of caustic potash containing about one-fifth of
its weight of sohd potash is to be substituted. The addition is to be continued at
intervals until three-fourths as much potash has been added as is equivalent to the
iodine in the iodide of amyl used. Tne fiuid may, after a quarter of an hour's ebul-
lition, be filtered to separate the resinous colour. The product is a gorgeous blue with
scarcely anj^ shade of red. On adding the other fourth of potash to the filtrate while
gently boihng, a black mass will be precipitated containing all the red, which other-
wise would have been mixed with the blue. This mass dissolves i^-adily in alcohol,
yielding a rich purple solution containing, however, an excess of red. The alcoholic
solution, on filtration, leaves on the filter a dark mass soluble in benzene, and as some-
times prepared, afibrding a brilliant emexald-green solution of great beauty. It is not
always easy to obtain this green colour.

It is only the chinoline prepared from cinchonine that yields these colouring matters :
a fact which points to an essential difference between this product and the isomeric
base fbund among the products of the distillation of coal. Cinchonine distilled wiUi
excess of potash, yields about 65 per cent of crude chinoline ; and all the distillate
which, on rectification (p. 869), distils above 199° or 209*^ 0. (390° or 408° F.), up
to the highest range of the mercurial thermometer, is suitable for the preparation
of the colour. One pt. of this distillate and 1^ pts. iodide of amyl, yield 23 pts. of
blue dye containing 4 per cent of solid colouring matter. (Gr. Williams^ Chemical
News, 1861, p. 219.)

Chinoline-violet and chinoline-blue are resinous substances, which present a coppery
appearance by refiected liffht, but when in very thin layers, appear of a violet or blue
colour by transmitted light They are bases and dissolve in acids, forming pale red
solutions, which ammonia restores to their original colours. They are slightly soluble
in hot water. Tannin precipitates them from their aqueous solutions, apparently
forming an insoluble compound. Reducing agents do not affect their shade of colour.
(W. H. Perkin, Chem. Soc. Qu. J. xiv. 246.)

Two volumes of chinoline-blue mixed with I vol. of Magenta pink (fuschine), of the
ordinaxy strength found in commerce, form a fine purple inclining to blue (Williams).
When chlorine is passed through an alcoholic solution* of chinoline-blue, a green
liquid is produced, which is perhaps the green spoken of by Williams. (Perkin.)

Syn. with Quinonb.

A fiuoride of aluminium and sodium, Na'Al^F*, occurring at Hiask
in the Ural, in snow-white, translucent, octahedral crystals, of the dimetnc ftystem,
in which the principal is to the secondary axes as 1*077 : 1 ; also massive, granular
resembling cryolite, with crystalline structure. Specific gravity 2*72 (Hermann);
2*842 — 2-898 (Ram m els berg). Hardness « 4. Analysis by Hermann (J. pr.
Chem. xxxvii. 188X gave 23-78 per cent Ka, 18*69 Al, the formtda requiring 23*4 and
18'6. Fuses easily before the blowpipe, and gives the reaction of fluorine. (Dana, ii. 98.)

874 CHITm.

(from x^'''^* A tunic). (Odier, Mim. Soc d'Hist Nat. de Fazis, i. 29.
• — ^Lassaigne, J. Chim. mM. iz. 379; Compt. rend, ztl 1087. — ^Payen, Compt rend,
xvii. 227. — C. Schmidt, Zur ftergleichenden Physiologie der wirbelloaen TlUere,
1845, p. 32; and Ann. Ch. Fharm. liv. 298. — ^Lenmann, Jahresber. d^gea. Hed.
1844, p. 7. — ^Fr^mv, Ann. Ch. Phys. [3] xliii. 94 ; Schlossberger, Ann. c£. Phann.
zcriii. 99. — Stadeler, ibid, cad. 21. — (Jerh. TVaiUy iv. 635. — ^Pelonze et Fr6mj,
TraiUf vi 93.) — ^The name given by Odier to the organic substance which forms the
elytrsB and integuments of insects and the carapaces of Crustacea. It may be obtained
by exhausting the wing-cases of cockchafers successively with water, ^cohol, ether,
acetic acid, and boiling alkalis. The final residue retains completely the form of the
wing-cases. Fr^my prepares chitin by treating the tegumentuy skeleton of a croa-
taceous animal with cola dilute hydrodiloric acid, to remove calcareous salts ; washing
with distilled water; boiling for several hours with solution of potash, which removes
adhering albuminous substances, and has no action upon chitin; again washing with
distilled water ; and purifying the residue with alcohol and ether.

Chitin thus prepared is solid, transparent, of homy aspect, insoluble in water, alco-
hol, and ether. It is coloured brown b^ solution of iodine. Alkalis have no action
upon it. By boiling with dilute acids, it is resolved into glucose and a nitrogenous
compound. (Stadeler.)

When chitin (from the carapace of the crab) is boiled for several hours with dilute
sulphuric acid, only the softer membranes are attacked, while the more solid integu-
ments become loose and soft, and fvm, after pressing and washing with water, a mass
havine almost the consistence of starch. The acid liquid supersaturated with lime,
and then neutralised with sulphuric acid, yields neither tyrosine nor leucine, but con-
tains ammonia, together with amorphous sugar, inasmueh as it precipitates cuprous
oxide abundantly from an alkaline solution of cupric oxide (Stadeler). Berthelot
(Ann. Ch. Phys. [3] Ivi. 149) likewise obtained sugar from chitin ^prepared- from the
integuments of lobsters, crabs, and cantharides,) by macerating it in strong sulphuric
acid till it was dissolved, dropping the solution into one hundred times its volume of
boiling water, boiling for an hour, saturating with chalk, &c.

The above-mentioned pasty residue is coloured brown-red by iodine, like unaltered
chitin, and by prolonged boiling with sulphuric acid, yields an additional quantity of
sugar, while the undissolved portion always contains nitrogen. The same substance^
after removal of the acid, forms with water a turbid emulsion, which takes a long time
to clarify, and dries up by spontaneous evaporation to a soft skin-like membrane, which
exhibits, with iodine-water, the same reactions as the original chitin. (Stadeler.)

The composition of chitin is determined by the following analyses : -*

Carbon .
Hydrogen
Nitrogen
Oxygen

Schmidt.

Meanofll

analysef.

Lehnaan.

SchloMberger.

StiUleler.

CmtetOaikm
C»H»NO».

46-64

46-73

46-64

46-32

46-35

6-60

6-69

6-60

6-65

6-44

6-66

6-49

6-66

614

6-01 1

40-20

4019

40-20

40-89

41-20 1

100*00 100-00 100-00 10000 10000

Fr^my found in chitin 43-35 carbon, 6-65 hydrogen and no nitrogen^ whence he re-
ffiuds chitin as isomeric with cellulose (44*4 C, 6-2 H, and 49*4 0). Gerhardt regarded
Fr^my's results as more correct than those of the G-erman chemists, because chitin
yields by dry distillation only acetic acid and empyreumatic oil, without any ammonia,
and the products of its putrefsiction under water are different from those of most nitro-
genous substances. But the analyses above given exhibit a closeness of agreement
which could scarcely be expected if the substances operated upon had been impure.
(See CsixtTiosB, p. 818.)

Stadeler regards chitin as a glucoside, C»ff *N0«, which is resolved by boiling with
acids into glucose and lactamide (or alanine or sarcosine) :

C»H'»NO« + 2BP0 - C^"0« + C»H»NO«

If this decomposition reaUy takes place, lactic acid should likewise be obtained as
a product of the transformation of the lactamide or alanine ; but the presence of
lactic acid among the products has not yet been demonstrated. Stadeler also suggests
that chitin (at least in Crustacea) may be formed by the union of lactate of ammonium
with gum, and elimination of water :

[C^*0».H.NH* + C^'«0» « C»ff *N0« -f 2BP0],
Acid lactate of Gum. Chitin.

ammoDlum

inasmuch as he has found gum in the juices of crabs and other Crustacea^ and the pre-

CHIVIATITE — CHLORACETIC ACIDS. 875

flence of lactic acid in the gastric jtiice of the lower animalu is bj no means im«
probable.

OBZVZATXTB. A solpliide of lead and bismuth, also containing copoer, from
Chiyiate in Peru, where it occurs, witii pyrites and heaTV spar, in foliated masses,
desTable in three directions in one zone, one malring an an^e with the second of 163^,
and with the third of 133^. Spedflo granty 6*920 ; colour lead-grej; lustre metallic
According to Bammelsberg's analysis (Fogg. Ann. buxviii 320) it contains 18*008,
60-05 Bi, 16*73 Pb, 2*42 Co, 1*02 Fe, with trace of silver, and 0*59 insoluble matter
(- 99*71), whence the formula 2(Pb«;Cu*)S.Bi«S«. (Dana» ii 77.)

OB&AS SXTB. See Mbtbobitbs.

fnrjjAtk MiM»M ■■■»■- l^atiTo arsenide of nickel containing cobalt, also called white

nickel. (See Nigkbl).

Syn. with Tbzchloiuobtaicidb (p. 6).

kOSTAMZO ACnia Syn. with Tbtbjlcelobaobtakidb (p. 6).

See AcBTAioDB (p. 6).

Two of these compounds are known, vis. mono- and
<rt-chloxacetic acids, both being produced by the action of chlorine gas on glacial acetic
add under the influence of light, the former when the add is in excess, the latter
when the chlorine and the acetio add are brought tog^ether in the exact proportions
required for its formation. The tridilorinated add is likewise produced in several
other reactions. Diehloracetio add has not yet been obtained, at least in definite form.

HoBocliloraeetio Aold* or simply Obloraoetto d^eld. CH*C10»C*H*C10.
H.O. (R. Hoffmann, Ann. Ch. Pharm. cii 1.)— Duinaa had observed that, in tiie
preparation of trichloracetic add by the action of chlorine on acetic add in sunshine^
a lower substitution-product is always obtained, espedally if the acetic add is in ex-
cess, in the form of an unciystallisable add, which nowever he did not succeed in pre-
paring in the separate state. F. Leblanc afterwards obtained this add, the monoduor-
actic add, in the form g( a colourless liquid, by passing chlorine through fflacial acetio
add in the shade ; his product however was not quite pure. More recenuy Hoffinann
has shown that the chief product of the action of chlorine on excess of acetic add in
sunshine, is monochloracetic add, and that this add, when pure, is solid and crystal-
line at ordinary temperatures.

Preparation. — 1. A tubulated retort of about 1 litre capadty and containing from
half a pound to a pound of gladal acetic add, is placed in a bath containing a saturated
solution of nitrate of sodium (boiUns at 120° C.\ and dry dilorine gas is passed into
the retort by a tube inserted through the tubtilure and terminatii^ just above the
liquid, so that the gas may mix immediatdy with the vapour of the add. The nedc
of the retort having a wide glass tube attached to it, is directed upwards, so that any
acetic add which evaporates undecomposed may be condensed and flow back again,
while the hydrochloric add and excess of chlorine escape. The whole apparatus is
placed in the sunshine, and the evolution of chlorine is so rcffolated that the upper part
of the retort always appears coloured by it The stronger me light, the more rapid is
the absorption of chlorme; but the action takes place, though slowly, even unaer a
douded sky. A very slow substitution of chlorine for hydrogen likewise takes place in
the dark and at ordinary temperatures. As the formation of chloracetic add goes on,
the action slackens, so that it is best, after about fifteen hours' exposure to sunshine, or
twice as long to diffbsed daylight, to expel the excess of chlorine nom the apparatus by
a steam of ary air, and rectify the product in a smaller retort The portion which dis-
tils bdow 130^ 0. consists almost wholly of unaltered acetic add, and may be used in
a subsequent preparation. That which passes over between 130^ and 190^ is easily se-
parated, by repeated rectification, into acetic and a thick liquid which boils between
185^ and 187^, and either solidfies immediately into a mass of white needlenfihaped
erystals, or yields after some time, lai^, isolated, transparent, colourless rhombic
taoles, while the greater portion remains liquid, but if shaken up or stirred with a
g^ass rod, solidifies suddenly and with considerable rise of temperature, the crystals
previously formed becoming opaque and white like porcelain. The czystalline mass,
which melts between 45^ and 47^, consists of nearly pure monochloracetic add, mixed
however with a certain quantity of liquid, which may be removed by decantation and
rapid pressure, and used, together with the portion of the original liquid which distilled
below 130°, in a subsequent preparation. The expressed crystals are placed on bibu-
lous paper and completely dnedm vacuo over oil of vitriol and a few lumps of hydrate
of potasnum, and then redistilled, the first and last portions of the distillate being re-
jected. As they are very deliquescent, they should oe kept as much as posdble from
the air. (Hoffmann.)

In the first distillation and in the subsequent rectifications, there is obtained a small
quantity of a liquid which boils above 190®, and appears to contain an acetic acid with

876 CHLOEACETIC ACIDS.

more than 1 at. hydrogen replaced bj chlorine. It yielded in different ejcperimfflits
from 48 to 50 per cent, of chlorine, which does not agree with the fonnnla either of
dichloracetic (requiring 56*04) or of trichloracetic acid (requiring 65*13 per cent, ci
chlorine). In one experiment^ this liquid, on being saturated with bajyta, yielded,
besides monochloracetate of barium, a small quantity of small, opaque, warty crystals,
the composition of which seemed to show that they contained a higher cLlorinated
acid ; but in no instance, eyen when the purest crystallised acetic aod was uBed and
the absoiption took place in the brightest sunshine, was any definite dichlorao^e or
trichloracetic obtained, the chief product being iuTariably monochloraoetic acid.
Neither was any oxalic acid formed, as in Dumas' preparation of trichloracetic acid
(pt 877). (Hoffmann.)

2. Monochloracetic acid is also obtained in a state of purity by the action of water
on monochlorinated chloride of acetyL On distilling the liquid, the thermometer rises
from 100^ to 180^, and the liquid which passes oyer at that temperature solidifies in
a aystalline mass on cooling. (Wurtz.)

ProperiieM. — ^The add czystallises from fdsion in rhombic tables, haying acute angles
of 77^ or 78°; from solution in acetic add — e,g, from the liquids obtained in the
first distillation between 180O and ISG^', and between 186° and 190°— in crystals hay-
ing a prismatic character, and yery much resembling those of trichloracetic add. Melt-
ing point 62°. It contracts strongly in solidiMng, and generally giyes off numerous
air^bubbles. The specific grayity of the melted add at 7^, is 1*366 as compared wiUi
water at 19°, and 1*3947 compared with water at 73°. Boiling point from 185° to
187*8°. It distils undecomposed, and when pure solidifies in the neck of the retort;
but if mixed with acetic acio, remains liquid below its ordinary point of solidifieatioii.
When kept for some time at a temperature near its melting pointy it sublimes in long
spicular ciystals. It is nearly inodorous at ordinary temperatures, but its yapour has
a pungent suffocating odour. It has a strong add taste, attacks the cutide, and raises
blisters if kept on it for some time. It deliquesces in the air, and dissolyes yeiy easily
in toaUr^ producing considerable fall of temperature.

Decompomtians. — 1. The add is decomposed hj pentachloride of phosphorus, with
formation of oxychloride of phosphorus and monochlorinated chloride of acetyl, bat the
two chlorides cannot be separated by distillation, as they both boU at about 110°.
When the product was repeatedly distilled with small portions of add chloracetate of
potassium, the residues of the last distillations yielded at high temperatures a large
proportion of chloracetic acid, the last portions of which boiled as high as 200°, and
had a more penetrating odour, probably arising from the presence of a small quantity
of the anhydrous add. — 2. The add heated with potash-l^, ammonia, baryta-water,
or lime-water, immediately yields a chloride of the alkali-metal and glycollic add.
(KekuU.)

C«H«C1M0« + BPO = Ma + (?H<0«.

8. Chloracetic add is reduced hj potasaium-amalgam or sodium^^analffam to acetic
add, in the same manner as trichloracetic add ; the decomposition is howeyer incom-
plete, and is attended with eyolution of hydrogen. (Hoffm ann.)

The Ohlobacbtatbs, CfCClMO', are obtained by digesting the oxides or carbo-
nates in the aqueous add : they are for the most part easily soluble and czystallisable.

Chloracetate of Ammonium decomposes by eyaporation like the potassium-salt.
It is more soluble than that salt» and solidifies only from a perfectly yisdd solution, in
the form of a crystalline cake, which deliquesces on exposure to the air.

Chloracetate of Barium, C«HH:JlBaO» + H«0.— May be obtained, eyenwiih
yery small quantities of material, in distinct prismatic crystals, apparently belonging
to the trimetric system, and containing 39*99 per cent barium (by calculation 40*06^
Decomposes but bttle during eyaporation, and separates out almost completely on cool-
ing from a hot saturated solution. (Hoffmann.)

Chloracetate of X^otassium, a. Neutral. 2C^*C1K0* + 3HK).— Obtained
by saturating the acid with carbonate of potassium and eyaporating to a syrup in yacuo
oyer oil of yitrioL It then separates in thin colourless laminae, which may be obtained
pure by draining on bibulous paper. It is not deliquescent^ and does not giye up its
water of crystallisation at 100° C., but is decomposed at a higher temperature, yielding
chloride of potassium, glycollic add, and a small quantity of glycolide, C»H*0'.
(KekuU, Ann. Ch. Pharm. cy. 288):

C^«C1K0« = Ka + C«BPO«.

It is also decomposed when its solution is eyaporated at a gentle heat. It is yery so-
luble in water. After drying in yacuo, it yielded 24*63 per cent potassium (by calcu-
lution, 24-55).
b. Acid. C«H*C1K0«.C«H»C10*.— When a solution of the neutral salt is mixed with

CHLORACETIG ACIDS. 877

as xnneh acid as it already contains, the whole solidifies to a thick pulp of small white
pearly crystals, which may be purified by draining on bibulous paper or by drying oyer
oil of yitriol. Sparingly soluble in water.

Chloracetate of 8il ver, CH'ClAgO'. — ^A hot solution of the acid saturated with
oxide of silver, yields the salt on cooling in splendid rhomboi'dal, iridescent laminsB
(Wurtz). — ^Anhydrous. Dissolves sparingly in cold, more readily in hot water, and is
easily obtained by cooling, in smsll nacreous scales, which blacken on exposure to
lights and yield chloride of silver. Between 110^ and 120° C. it decomposes with a kind
of explosion, emitting the same odour as the add when it evaporates, and leaving
chloride of silver, mixed with a very small quantity of metallic silver.

Chloracetate of Ethyl. C*H'C510* - C«H?C10»,C*H». (E. Willm, Ann. Ch.
Phys. [3] xlix. 97.) — Obtained by the action of alcohol on monochlorinated chloride of
acetyl :

c*RK) + c«Hra«o - c*H^ao« + Ha

The action, which is very violent^ must be moderated by cooling the vessel externally,
and as soon as it is finished, the product may be washed with water, dehydrated by
chloride of calcium and rectified.

Colourless liquid, having an ethereal odour and burning taste, heavier than water
and insoluble in that liquid. Boils at 143^*5 C. when the barometer stands at 758^ mm.
Vapour-density 4'46.

The ether bums with a bright flame, green at the edgea. It is decomposed by
potash, into alcohol and chloraoetic acid, which then sufiers further decomposition,
yielding chloride and acetate of potassium.

THobloraeetto Aold. C^Ha^O* -» C*a*O.H.O. (Dumas, J. Ghim. m6d. vi
669; also Ann. Ch. Pharm. xxxii 101; Ann. Ch. Phys. Ixxiii. 76; M els ens, Ann.
Ch. Phys. [3] x. 233 ; Malaguti, Ann. Ch. Phys. [3] xvi 10 ; Kolbe, Ann. Ch. Pharm.
liv. 182 ; Gm. ix. 209; Gerh. i. 749.) — This acid was discovered by Dumas in 1839.
It is j^roduced : 1. By the action of 6 at. dry chlorine gas on 1 at. glacial acetic acid in
sunshme (Dumas) :

cm*o* + oa « cmciK>* + shcl

2. In the oxidation of soluble chloral by a mixture of hydrochloric acid and chlorate
of potassium, and of chloral either soluble or insoluble, by fuming nitric add (E olbe) :

CHCl'O + O - C«HC1»0«.

3. By the action of chlorine gas in sunshine on dichloride of carbon covered with a
layer of water (Kolbe) :

(?a* + 2H«0 + Cl« « C«Ha«0« + ZRCI;

part of the CCl^ is at the same time converted into 0*C1*. — 4. In the decomposition
of chloride of trichloracetyl (chloraldehyde) by water (Malaguti) :

CKJi*0 + H*0 « CmCiH>» + HCL

6. In the decomposition of perchlorinated formic ether by water (does, Ann. Ch
Phys. [3] xvii 800) :

C«a«0» + 2HK) « C»Ha»0« + C0» + 8Ha

PreparaHon. — 1. When glacial acetic acid is exposed to the sun in bottles of 5 or 6
litres capacity (in the proportion of 0*8 or 0'9 grms. of the add to I litre of chlorine)
crystals of trichloracetic acid make their appearance in about a day, together with a
small quantity of oxalic add. On opening tne bottles, a mixture of hydrochloric acid
gas with a small quantity of carbonic acid and a suffocating vapour, escapes with force.
The bottles are then left open for some hours, till the gaseous mixture is completely ex-
pelled, and washed out with a small (quantity of water, whereby a concentrated solution
of trichloracetic add is obtained, mixed, however, with hydrochloric add, undecom-
posed acetic acid, and oxalic add. When this solution is evaporated in vacuo over oil
of vitriol and hvdrate of potasdum, water, hydrochloric ad^ and part of the acetic
acid escape, and the solution then yields crystals, first of oxalic, afterwards of trichlor-
acetic add. The mother-liquor distilled with phosphoric anhydride, which decomposes
the oxalic add, yieldb a distillate of acetic add, and tiien, on changing the recdver, of
trichloracetic acid, which soon solidifies to a crystalline massTLastly, the crystals
are left for some hours in vacuo on several sheets of white blotting paper, so tliat the
admixed acetic acid ma^ soak into the paper. (Dumas.)

2. Insoluble chloral is treated with fuming nitric add, and the action, which is at
first attended with evolution of heat and abimdant evolution of red fumes, is afterwards
assisted by the application of a gentle heat, till the flakes of insoluble chloral have com-
pletely disappeared; the greater part of the excess of nitric acid is then distilled off;

878 CHLORACETIC ACIDS.

and the lem&uiing portion is left to evaponte in racao OTar oil of litriol and hydrate
of potassium. (Systallised trichloracetic acid then remains, free from nitric, aoetie,
anil oxalic add, but generally retaining traces of chloraL (Kolbe.)

8. When dichloride of carDon« CKji\ is placed in a bottle filled with chlorine gas,
covered with a film of water, and exposed to the son, there ia formed, besides C?CL\
an aqueous solution of trichloracetic add, which may be obtained in the OTBtaUiiie
state by evaporation in vacuo over oil of vitriol and lime. (Kolbe.)

4. Ghloraldehyde is dissolved in water ; and the solution containing hvdrochlorie acid
is evaporated in vacuo over oil of vitriol and hydrate of potaasium, whereby trichlor-
acetic add is obtained in beautiful ciystals. (Malaguti)

Properties. — Trichloracetic add forms colourless rhombohedrons. It melts above
46^ C, and in cooling bep;ins to solidify at 45^ ; if the mass be then shaken, the tem-
perature rises to 46^, which is therefore the meJting point In the fused state, it has
a density of 1'617 at 46°, that of water at 16° bei^ 1*000. Boils between 195<> and
200° without any deoompodtion, and sublimes in the form of a silvery crust Vapour-
density^ «s 6*3, by calculation 6*637, the difference arising from partial decompodtion.
The add has a nunt odoor at ordinary temperatures, but when heated till it volatilises,
it emits a pungent and suffocating odour. It has a caustic, sour taste, and makes the
tongue white, Lke peroxide of hydrogen. It destroys the cutide, causing it to peel off
on the following aay, and if left for some time on the skin, produces blisters. It
reddens litmus strongly, but does not bleach it, even after a oondderable time. It
ddiquesoes in the air and dissolves readily in water. (Dumas.)

Deoomporitions, — 1. When the add is heated with strong stdphurie acid, part of it
distils over undianged, and crystallises in rhombohedrons ; the rest is resolved into
hydrochloric acid, carbonic anhydride, and carbonic oxide (Dumas). [Perhaps in this

manner: C»HCa«0« + HH) « 8HC1 + CO + CO^ 2. When it is heated with

excess of potash-solution, ebullition takes place, continuing after the vessel has been
removed from the fire ; Ihe first products of the action are chloroform and carbonate
of potassium ; but on frurther boiling with the alkaline liquid, the dihnofonn is resolved
into formate and chloride of potasdum. (D u m as.) — first :

C«HC1«0« + K«0 = CHC1« + K*CO»
then: CHCa* + 2K*0 = CHKO* + SKCL

When the add is boiled with baryta-water, carbonate of barium is predpitated and
chloroform evolved (Dumas). — 3. The add boiled with excess of ammomcL, is re-
solved into carbonate of ammonium, which sublimes, and chloroform, which sinks down
as an oil (Dumas):

Cma«0« + (NH*)K) » (NH«)».CO« + CHa«.

4. Aqueous trichloracetic add, or either of its salts dissolved in water, is deeompoeed
hy potcusittm-afnalgam (1 pt potasdum to 160 pts. meremy) with evolution of heat^
and reconverted into acetate^ of potassium (M els ens), u the ftTn«1g»^ni is not in
excess in proportion to the add, no hydrogen is evolved. Antimonide of potassium,
or potassium alone, or dnc with sulphuric add, does not efifect the transfbnnation,
but causes an evolution of hydrogen gas (Melsens). — If instead of 6 at potasdum,
only 8 at be used in the form of potasdum-amalgam, no acetic add is produced, but
apparently an add containing a smaller quantity of chlorine than trichloracetic add.
6. Zino mssolves in aqueous trichloracetic add, and forms, besides diloride of zinc,
a zine-salt which appears to contain didiloracetic add C^CV^HH)*, Trichloracetio
add is also reduced to acetic add in the galvanic circuit of a two-pair Bunsen's dnc-
oarbon battery, with dectrodes of amalgamated zinc (Kolbe.)

Tbioklobaobtatbs. — Trichloracetic add is monobadc, like acetic add, the
formuk of its salts being G^C1*0*.

Trichloraeetate of Ammonium, C^H*)C1»0» + 2H«0.— The aqueous add
saturated with ammonia, and evaporated at ordmary temperatures, dther in vacuo
or in the air, yidds crystals (Dumas). The salt is likewise produced when trichlor-
acetamide is brought in contact with aqueous ammonia or very dilute nitric add
(Malaguti, Cloez). It erystalHses in beautifiilprisms (containing 2 at water, melts
at 80° ; boils between 110° and 116° C, giving offvapours of chloroform and add car-
bonate of ammonium, the latter appearing in peculiar abundance at 146° ; and solidifies
at 160° in yellowish, micaceous scales of anhydrous trichloraeetate <^ ammonium,
which are tastdess, dissolve readily in water, and give off ammonia when treated with
potash, even in the cold. At a higher temperature, these scales fuse, and are xeadved
into carbonic oxide, phosgene, and sal-ammoniac vapour. (Malaguti)
Deoompodtion of the crystallised salt:

C^NH*)a«0» + 2H«0 « CHCl* + NH*.aCX>» + H«0.

CHLORACETONES— CHLORACETYPHIDE. * 879

Decomposition of the anhydrous salt :

C«(NH*)a"0» - CO + CCIK) + NH*CL

Trichloraeetate of Potassium. 2C'KC1"0« + H'O.— The aqneons add neu-
tralised with carbonate of potassium yields by spontaneous eraporation, silky needles,
which decompose with a kind of detonation when gently heated, and absorb onfy a
small quantity of water when exposed to damp air. (Dumas.)

The Bariwn and Caleium salts are neutral and dissolve yery readily in water.
(Dumas.)

Trichloraeetate of Silver. C*AgCl*0". — Eecently precipitated oxide of silver
immersed in the aqueous acid is converted into grey laminae which dissolve in a larger
quantity of water, and crystalliBe therefirom by evaporation in vacuo over oil of vitriol
and in the dark, in crystalline granules and laminse. The salt is yery readily decom-
posed by light When heated on a sheet of ^aper, it detonates violently, giving off,
the same ^our as trichloracetic acid when it evaporates, and leaves vegetations of

Sure chloride of silver. If it be moistened with alcohol and the alcohol set on fire, it
ecomposes more quietly, and without projection. (Dumas.)
Trichloraeetate of Ethyl. Tnchloraeeiio Ether. C"C1»0«.0«H». — Obtained
either by distilling trichloracetic acid with alcohol and a small quantity of sulphuric
add (Dumas), or by gradually adding chloraldehyde to alcohoL (Malaguti)

00*0 + CHK) = C«aH)«.C«H» + HCL

Chloral-
dehyde.

The product obtained by either of these processes is predpitated b^ water, washed
with water, and dried over chloride of caldum. It is a colourless oil, smelling like
peppermint. Specific gravity 1*367. Boiling point 164^. Vapour-density 6*64.

Aqueous j^tash decomposes it, forming alcohol and trichloraeetate of potassium :

C«C1«0».C»H» + KHO - C«HK) + C«C1»K0«.

Ammonia converts into trichloracetamide, N.H*. 0*01*0 ^p. 22).

Exposed to the action of chlorine in daylight, and in direct sunshine, it yields the
■ame products as acetate of ethvl (p. 22). It is isomeric with the compound obtained
by passing dry chlorine through dichloracetic ether contained in a vessel, the upper
part of which is protected l^m the light. The two compounds are distinguished
nom each other by their behaviour with potash, the latter yielding, not trichloraeetate
of potassium, but chloride of potassium, deliquescent chlorinated potassium-salts, and
a sweet oily liquid no longer decomposible by potash. (Leblanc)

The higher chlorinated compounds produced by the action of chlorine on acetate of
ethyl may be regarded as compounds of trichloracetic add with ethyl in which the hy-
drogen is more or less replaced by chlorine : thus tetrachloracetic ether 0*H*CP6*
- 0«a«0«C«HH}l; perchloracetic ether, C*C1«0« - CKJ1«0».C»C1». All these com-
pounds, indeed, when treated with potash, yield trichloraoetate of potassium, s.ff, :

C«C1»0» + 2KH0 « 2C«a*K0» + 2HCL
Some of them however appear to be susceptible of isomeric modifications.

Trichloraeetate of Methyl. 0*C1K)*.0H*.— Obtained by processes exactly
similar to those which yield the ethyl-compound, vis. by distilling the acid with wood-
spirit and sulphuric acid, or by the action of wood-spirit on chloraldehyde. It is a
colourless oil, heavier than water, and smelling like peppermint. It is isomeric with
the compound C*H'C1*0*, obtained by the action of cmonne on acetate of methyl. The
two compounds are not however identical; for the former is converted by potash into
methyl-alcohol and trichloraeetate of potassium (together with formate and chloride
of potassium resultins from the farther action of the potash, p. 45) ; the latter when
treated with potash yields chloride and formate of potasdum, together with ^lorome-
thylase, CHCl (Lauren t see p. 23.)

Trichloraeetate of methyl exposed to the action of chlorine in sunshine, is converted
into perchloromethylic acetate, 0*01*0*, a compound also produced by the continued
action of chlorine on acetate of methyl.

CB&OXJLOaTOVBfl. See Acbtonb (p. 29).

OXIiOBJLOBTOVXTIKiaUi* See Acbtonitbilb (p. 38).
! CK&OBAO MT I Jm 0*H*C10. — ^The radicle of chloracetic add, chloracetamide, &e.

Trichloraoetyl, 0*01*0, is the radide of tridiloracetic add, tridiloracetamide, chloral,
chloraldehyde, chloralide, &;c

OK&OSACBTTVKZBB. Trichloracephosphide. Phosphide of Trichloraeetyl and
Bydrogen. ^ 0*H*a*PO « P.H*.0*01*0.— This compound, the analogue of tnchloi^
acetamide, is produced by the action of chloride of tridbloracetyl on phosphoretted
hydrogen:

0*a*0.a + PH* = HCl + P.H».OK1*0,

880 CHLORAL.

also, together with oxychloride of carbon, when phosphozetted hydrogen is passed into
heated perchloroformic ether :

c«a«o« + PH« « p.mc^K) + ooa« + hcl

It forma small, white, crystalline scales, having a slightly alliaceons odour and bitter
taste. It is permanent in the air at ordinary temperatures, but decomposes when
heated, leaving a carbonaceous residue containing phosphoric acid. It is insoluble in
water; slightly soluble in alcohol, ether, and wocS-spirit (Cloez, Ann. Oh. Phys. [3]
xviL 309.)

CB&0»A&. Hydride of Trichloraoetyl. C^CIK) » 0K}1*0.H.— This body waa
discovered by Liebig in 1832 (Ann. Ch. Pharm. L 189X and further ezamin^l by
Dumas (Ann. Ch. Phys. [2] lyi 123) and Stadeler (Ann. Ch. Pharm. bd. 101). It
is the ultimate product of the action of chlorine upon alcohol :

C^'O + CP - CHCl'O + 6E.CL

Probably the alcohol is first converted into aldehyde by abstraction of 2H ; and in
this compound 3H are afterwards replaced by 3C1 (see Auconot),- Choral cannot,
however, be obtained by the direct action of chlorine on aldehyde ; it appears to be
produced in the first instance, but is quickly converted into other products. For the
production of chloral from alcohol, it is absolutely necessary that the alcohol be anhy-
drous ; if water is present, aldehvde, acetal, acetic acid, acetic ether, and other pro-
ducts are formed instead of chloral ; these products also accompany the chloral, even
when the preparation is made with absolute alcohol (see Alcohoi., Decomposition by
Chlorine, p. 74). Chloral is also produced by the action of chlorine on starch or
sugar. (Stadeler.)

Preparation. — 1. fVom alcohol. Pure and dry chlorine gas is passed into absolute
olcohi^ contained in a tubulated retort having its neck duected upwards, and fitted

with a long condensing tube, which passes down
Fig. 127. ; ^ to the bulb, and projects considerably above the

extremity of the neck to cany off uncondensed
gases; the chlorine is introduced through the
tubulus. Or the alcohol may be contained in a
tube bent, as shown mfy, 127, the middle por-
tion being 2 or 3 ft long, and placed at a*slight
inclination, so that the chlorine entering at the
a ^""^ lower part, may pass through a column of alcohol

of considerable length but no great height. The
chlorine is best evolved firom a mixture of common salt, peroxide of manganese and
sulphuric acid (which gives it off more regularly than hydrochloric acid and maganeee);
it must be passed first through a wash-bottle containing water, and then through sul-
phuric acid or over chloride of calcium, to dry it. The unabsorbed chlorine, together
with hydrochloric acid gas and vapour of hprdrochloric ether, may be passed into two
Woulfe's bottles, and thence into the open air, so that the oj^erator may not be annoyed
by it. At the commencement of the operation, the alcohol is cooled by afiusion of cold
water, to prevent it from taking fire and depositing soot ; but afterwards, when the
absorption of the chlorine diminishes, and the liquid assumes a yellow colour, it must
be gradually heated, and at last nearly to the boiling point ; 200 grammes of alcohol
require the passage of a rapid stream of chlorine to be continued for 15 or 20 hours,
involving a consumption of about 1200 litres of chlorine gas. The alcohol becomes
continually thicker, acquires a higher boiling point, and is finally converted into a
heavy syrup, which, after standing for some days, solidifies completely to a Boft» white
cryBtalline mass, consbting of hydrate of chloral, together with a small quantity of
hydrochloric acid and undecomposed alcohol : Crude Hydrate of Choral. If a sample
of the liquid, after being agitated with four times its volume of sulphuric acid, and
set aside, does not in a few hours form a solid stratum of insoluble chloral above the
oil of vitriol, the passage of the chlorine must be continued for a still longer time.
The solidified dystalline mass is heated till it melts, briskly agitated witii 4 to 6
times its bulk of sulphuric acid, which does not heat or blacken it ; left at rest till
the dehydrated chloral has risen to the top of the sulphuric acid, a result which may
be accelerated by gentle heating ; and the transparent, colourless film of chloral is
immediately decanted by means of a pipette. If the sulphuric acid contains water,
it is particularly necessary to decant as quickly as possible, before the chloral is
thereby converted into insoluble chloral. Lastly, the chloral is distilled over lime
which has been slaked and subsequently ignited, to remove hydrochloric acid, care
being taken to keep the whole of the lime below the surface of the liquid, as it will
otherwise decompose the vapour and become red-hot. In tliis manner the chloral
is obtained tolerably pure ; but it still contains traces of water and alcohol, which

CHLORAL. 881

may be removed bj repeated treatment vith sulphario acid, the chloral being each
time rectified over Ume. All these operations must be performed in well closed yessels.
(Liebig.}

2. By oiHtilliPg starch or sugar with hydrochloric add and peroxide of manaanese
(Stadeler). 1 pt. of starch, or grape-sugar, or common sugar, is gently heated with
7 pts. of commercial hydrochloric acid free from snlphnrons acid and diluted with an
equal Tolume of water, tiU the paste (formed when starch is used) has become fluid ;
the li(}uid, when cold, is introduced, together with 3 ots. of manganese and a smidl
quantity of common salt (to fix the sulphuric acid proauced from the sulphurous acid
in the commercial hydvcN^oric add) into a capadous fiask, in which it is heated as
quiddy aa posdble to the boiling point ; and the fire is then completely remoyed. The
mass swells up, giying off a large quantity of carbonic acid, and continues to boil
for some time by itsdt Ab soon as the ebullition slackens, it must be kept up by
firesh application of heat, and the distillate collected, as long as it becomes turbid when
mixed with tolerably strong potash-ley (in consequence of separation of chloroform
from the chloral). More hydrochloric add is then repeatedly introduced into the flask
by small portions, till the distillate no longer smells of chloi^ or becomes turbid with
potash. The watery distillate is carefully freed firom the colourless oil-dro^ heavier
than water and smelling of cMoroform, which are produced at the be^nning of the
distillation ; and saturated with common salt, in onler to raise its boiling point and
retain the water. It is then redistilled, and the resulting distillate is in^ from a
sulphur-ydlow very pungent oil, and distilled several times more with common salt,
the oily drops being each time removed, in order to obtain aqueous chloral as concen-
trated as posdble, and as ftoe as posdble from the yellow ou, which greatly impedes
the purification.

The removal of this oil is fiicilitated by saturating the distillate^ before each rectifi-
cation, with chalk, whidi decomposes the oil, l)ut does not attack the chloraL The
concentrated solution of chloral is saturated with drv chloride of calcium, and dis-
tilled in an oil-bath at 120^ 0. Hydrate of chloral then passes over, as a colourless
liquid, which aoUdifies in the receiver into a crystalline mass. The last portions of
the distillate are contaminated with a brown oily substance. 1. From the hydrate
of chloral thus obtained, the anhydrous chloral may be separated by distillation, and
purified in the manner above described. (Stadeler.)

Properties. — Chloral is a thin colourless oil, greasy to the touch, and making grease-
spots on paper, which, however, soon disappear. Specific gravity » 1*602 at 18^ C, 1*518
at 0^, 1-4903 at 22^. Boils at 94-4<> (Liebig) ; at 98*6 when the barometer stands at
760 mm. (Ko p p), and distils without decomposition. Vapour-density ^ 6* 1 3. It has a
peculiar pungent odour, and exdtes a copious fiow of tears : its taste is greasy and slightly
astringent. It acts very strongly on the skin, especially when its bomng vapour comes
in contact therewith. It has no add reaction, even when dissolved in water, and does
not predpitate a solution of silver.

luxed with a small quantit|r of water, it becomes heated and solidifies, forming a
mass of crystals of hydrate of choral, CHCl'O.HH) : a larger quantity of water dis-
solves it, and the sohition evaporated in vacuo deposits the hydrate of chloral in large
rhombic laminsB. The hydrate volatiUsee graduinlly in the air, and distils without
decompodtion when heated. Its vapour-dendty is 2*76.

Chloral dissolves also in alcohol and in ether. It absorbs chlorine gas without
further change, and readily dissolves iodine, bromine, sulphur, and phosphorus, especi-
ally when heated. The iodine-solution has a purple-oolour<

DeoompoeUione, — 1. Chloral is under certain circumstances inclined to pass into
an isomeric insoluble modification (p. 64). — 2. Anhydrous chloral distils, for the most
part unchanged, with strong sulphuric acid; but when hydrate of chloral is heated
with that acid, part of the chloral distils over in the anhydrous state, while the rest is
converted into chloralide (p. 61), with evolution of hydrochloric and sulphurous
adds, and a trace of carbonic add. This reaction serves for the detection of chloral
in liquids. The liquid, concentrated by several distillations over chloride of caldum,
is heated for some time, with six times its volume of strong sulphuric add, to 125° C,
and diluted, after cooling, with six measures of water. Chloralide then separates out
mixed with carbonaceous particles ; and the mixture washed, pressed between paper,
exhausted with ether and evaporated, yields crystals of chloralide, which may be
further purified by heating with sulphuric acid and reciystalliBation from ether. —
3. Fuming nitric acid, if ultimatdy aided by heat, converts chloral into trichloracetic
add : the same transformation is effected by a mixture of hydrochloric add and
chlorate of potasdum. — 4. Anhydrous metaUio oxides, such as baryta, strontia, lime,
cnpric oxide, mercuric oxide, and peroxide of manganese, exert no action upon chloral,
when that liquid is distilled over them. If, however, in the distillation of chloral over

Vol. I. 8 L

882 CHLORAL.

Uoytay ptiontu or lime, a portion of the oxide is left diy, or if either of thew sabstanees
is heated in chloral Taponr merelj to 100^, it beoomes zed-hot» and oompletelj de-
composes the choral, with erolation of carbonic oxide^ and fixrmation of a metal-
lic chloride mixed with charooaL — 6. Alkalis, either in the form of solid hydrates
or of aqneons solutions, decompose chloral readily^ at ordinazy temperatozesy with
erolntion of heat^ oonreiting it into formate of potassinm and chlorofarm, and a portiofu
of tlie latter compound is farther decomposed, yielding finmate and diloiide of potas-
sinm:

CHa*0 + EHO B CHKO* + CHGl'.

Chlonl. Fonnat* Chlmoftw.

ofpotauliim.

and CHa* -i^ iKHO - CHKO* + ZKCl -h 2H*0.

— 6, Vaponr of chloral passed oyer red-hot iron yields carbonic oxide, and chloride
of iron mixed with charcoaL — 6. PotoMtv m, in contact with chloral, eliminates hydrogen*
and forms a resinous body from which water extracts potash and choride of potassium.
— 7. Chloral forms with ammonia a compound, which, lilce aldehyde-ammonia, reduces
silTer in the specular form, and from which sulphydric add throws down a sulphuretted
compound apoarently analogous to thialdine (Stadeler, Ann. Ch. Phann. cvi. 263).
— 8. Sulphydria acid ga» passed through an aijueous solution of chloral separates
a sparing^ soluble crystalline compound, which is probably analogous to ace(^l-mer-
Cfl^tan (p. 107), but decomposes much more easily, giying off sulphydiic acid eyen
during dzying (Stadeler). — 9. By boiling hydnite of chloral with IMro^ame
Kudhydrochlorie add, a ^rupy ada is formed resembling lactic acid. These last
three reactions indicate a close analogy between chloral and aldehyde, which is further
strengthened by the fact that chloral forms crystalline compounds with add sulfates
of alluUi-metsL (S ta d e 1 e r.)

IfiBoluhU Chloral, I£etaehloral{Q[iiLym,205\ GerlLL671.) — Chlonl is eon-
yerted, under certain drcumstances, into an isomeric modification insoluble in water.
This diange takes place spontaneously when chloral is preserved in a stoppered
bottle, or when it is placed m contact with a quantity of water not sniBdent to con-
yert it into the hydrate. Metachloral thus prepared is pure, and has the same com-
position as chloiaL It is also produced, mixed, howeyer, with a little ddoralide,
by the action of sulphuric add upon chloraL A layer of the crude hydrate of chloral
obtained in the preparation of chloral from alcohol (p. 880), left in ecmtact with
strong sulphuric add, solidifies in a few hours into a mass of insoluble chloral. Pure
chloral in contact with six times its yolume of strong sulphuric add, nndagoee the
same transformation in the course of a night. The metaduoral thus obtained may be
purified from chloralide by pulverising^ and washing it, first with water and then with
alcohol.

Mefachloral is a white powder, greasy to the touch, and having a £unt aromatic
odour. It yolatilises slowly in the air or in vacuo. It is insoluble in water, alcohol,
and ether. When perfectly dry, it is reoonverted by heat into soluble chloral, at 180°C,
according to Kolbe, above 200^ according to BegnaulL Heated with sulphuric add,
it partly distils over as soluble chloral, but a considerable portion is decomposed,
with formation of chloralide, and evolution of hydrochloric and sulphurous adds. By
frmiing nitric add, metachloral is, like chloral, converted into trichloraeetie add ; but it
is not attacked by a mixture of hydrochloric add and chlorate of potassium. With
solutions of the caustic alkalis, it behaves like ordinary diloral, yielding an alkaline
formate and chloroform ; but the quantity of the latter is less as the ^ali is more
concentrated.

See Chlobaxtlax..

This name was applied by Eane (Pogg. Ann. xlir.
473) to a pungent yedcating liquid of specific gravity 1*83, and boiline at 71° C,
which is obtained by passing dry chlorine into acetone. Eane^s analysis gives 66'8
per cent chlorine; Liebig found only 52*6 per cent. It is probably a mixture con-
taining two or more of the chloracetones (p. 29).

C«&OBA&» VKOPZOVZC. Rvdride of Peniachloropropione, C*aK)*.H. This
body is*found amongst the products ootained by <^i«t:il1ing starch with a mixture of
hydrochloric acid and peroxide of manganese. On saturating the acid distillate with
chalk or carbonate of sodium, and rectifying over a small quantity of chloride of caldum,
the propionic chloral passes over among the first portions, together with an oil. To
remove the latter, the rectified distillate is flgitat4Ml seyeral times with ice-cold water,
and the cold saturated solution is decanted and heated, the promonic chloral then
separating in heavy drops having a faint yellow colour. By diffhging these drop^
through a small quantity of water, and exposing them to a temperature of 0° C,

CHLORALBIN — CHLOBALDEHYDES.

883

ooloiiiiefla tables are obtained, which may be purifled from adhering oil by raesmm
between Hbulona paper. They oonsist of a hydrate containing 4 at. water : CHCIK)*.
4HH>. (Stadeler, Sandw. <£ Chem. SuppL ii 796.)

cniTiO'B ik ¥tBTW« G'H'Cl*. — A. dyetalline substanoe contained in trichlorophenic
acid prepared by pasain^ chlorine through coal-tar. It is separated by treating the
erode aad with ammonia and alcohol, or better with ether, whereupon the ehloralbin
remains in rery white needles ; it may be flxrther pniifled by dissolving it in boiling
ether. It is but sparingly soluble in boilins alcohol, and insoluble in allalis. It boils
at 190^ C, and dystaUises on cooling in fem-Uke tufts. At a higher temperature,
it sublimes without alteration and czystallises in needles. It is not attackea by hot
nitric or sulphuric acid. (Laurent^ Bey. sdent. yi. 72.)

OBXASAZABKTBJHS. These compounds are aldehydes in which the hydrogen
is more or less replaced by chlorine, and may be regarded as derixed from the cor-
responding acids by the substitution of 1 or more at. Silorine for an equivalent quantity
of peroxide of hydrogen HO, thus

Ch1onldebjdM« Acldf.

. C*H»0.C1 C*H»O.HO

. CHl'O.a 0H31«0.H0

. N0«.C1 NO».HO

. (S0«)''.C1« (SOy.rHO)*

. (P0)'".C1« CPO)"'.(HO)»

Acetic

Trichloracetic
Nitnc • •
Sulphuric .
Phosphoric .

The chloraldehydes are a more numerous class of compounds than the alde-
hydes themselves, including many compounds usually denommated ozychlorides,
«. a. «xychloride of phosphorus. They Dear to their ooiresponding acids the same
xeUtion that metallic chlorides bear to metallic hydrates.

The tenn chloraldehyde is also specially applied to the second compound in the
above Ust» vis:

Chloride of Triehlor acetyl or Perchlorinated Aoetie Aldehyde^ CHjI*Ob,
(TGl'O.CL— This body, discovered by Malaguti (Ann. Ch. Phys. I [2] xvi 6); Gm.
ix. 218 ; Gerh. i 766), is a constant product of the action of heat on the perchlorinated
ethylie (vinic) ethers. Thus:

CKn*0 + c«a«.

Seiqalchlorido
of carbon.

CHJI*0 + COCi*.

OxTchlorlda
of cirboD.

2<xa*o

tato of ethyl.

0K31»«0» - CH31*0 + C«C1« + CO*.

Pvrchlor. car-
bonate of ethyl.

CH31«^« -
Perchlor. oxa-
late of ethyl.

c*a>»o -

Perchlor. oxide
of ethyl.

CH31«0« -
Perchlor. ftyr*
mate of ethyl.

C*C1«0« «
Perchlor.

2CH3i*o + coa« + CO.

It is best prepared from perchlorinated oxide of ethyl, C*C1'*0 (the product ob-
tained by the continued action of chlorine in sunshine, on anhydrous euier). This
compound is resolved at 300^ 0. into chloride of trichloracetyl and trichloride of
carbon ; and by subjecting the mixture to rei>eated fractional distillation, the tri-
chloride of carbon is left behind, and the chloride of trichloracetyl is obtained pure.
The rectification must be continued till the distillate no longer shows any turbidity
when mixed with water.

Chloraldehyde is a transparent, colourless liquid, of specific gravity 1*603 at 18^ C.
Boiling point 118^. Vapour-density 632 (calc. 2 vol 6*295). It gives off excessively
pungent vapours on exposure to the air, and when placed on the tongue, first excites a
sensation of dryness, tnen forms a white spot, and ultimately exerts a caustic action.
It reddens litmus after a few seconds.

It sinlcs in water, and gradually dissolves, forming a dear solution of hydrochloric
and trichloracetic acids : the same decomposition is produced by aqueous solutions of
the fixed alkalis :

CK31H).C1 + HK) - HCl + C»a»O.H.O.

When a small quantity of alcohol is poured upon it, great heat is evolved, and the
whole is quiddy volatilised ; but if the chloraldcSiyde be slowly added to an excess ot

8l 2

884 CHLOEALIDE.

alcohol, gradual decomposition takes place, attended vith but little rise of temperatqic^
the pzoducte being hycurochloric acid and trichloracetate of ethyl:

c«a"o.ci + c*H»^o « Ha + c«cih).c^».o.

With ammonia it forms trichloracetamide (p. 22) ;

CH:J1*0.C1 + 2NH» = N.H*.C»CIK) + NH*C1,

and with phosphoretted hydrogen, PH", the analogooB compound, chloracetyphide,
P.H«.(?C1"0 (p. 879).

caObOmA&ZBB. C*H*C1*0*. (Stadeler, Ann. Ch. Fharm. IxL 104.— Keknl^
ibid. CT. 293.) — ^A crystalline oomponnd obtained by the action of sulphnric add upon
hydrate of cnloraL To prepare it, hydrate of chloral is ^tly heated with 4 to 6
times its Tolnme of strong sulphnric acid, the mixture being weU shaken, and then
distilled at a heat between 120^ and 130^ C, as long as unaltered choral continues to
pass over. This choral is reconyerted into hydrate by addition of a little water, then

Soured back, and the distillation is repeated till the greater part of the chknal ia
ecomposed. The sulphuric acid is then found to be coTered with a colourless oily
liquid, which solidifies on coolii^ into a white czystalline crust This mass is broken
up, the sulphuric acid is drained ofP, and the crystals are washed ydth water, till the
wash-water no longer reddens litmus ; they are Uien dried between bibulous paper, and
dissolved in ether, and the ethereal solution is mixed with } its volume of aloohoL
The ddoralide then separates as the ether evaporates, in well-defined crystals, which
must be crystallised several times from a mixture of alcohol and ether, in order to free
them from an oily matter which adheres to them : — According to Kekule (Anzu Ch.
Pharm. cv. 293), a purer and more abundant product is obtained by the action of
fuming sulphunc acid on hydrate of chloral. When chloral which has been onoe
distilled over ordinary sulphuric add, is mixed with an equal volume of add, a large
quantity of hydrochloric add is evolved, and about one-third of the chloral is con-
verted mto chloraIid& Carbonic oxide is also given off abundantly, together with a
very small quantity of carbonic anhydride ; sulphurous anhydride occurs only towards
the end of the process. The oily distillate soudifies on cooling in a crystalline mass,
which may be purified by reci^tallisation from boiling alcohoL ^ *

Kekuld explains the formation of chloralide and the accompanying products bj the
following equation : —

8C»Ha«0 + BPO - C*HK31H)« + 3HC1 + CO.

Stadeler, on the other hand, conddets it improbable that the conversion of the chloral
into chloralide can be due to the action of water, inasmuch as fuming sulphuric add
seems to act better than ordinary sulphuric add. He supposes that a triple molecule
of chloral (insoluble chloral) splits up into chloralide and chloroform, according to the
equation:

scmciH) » C»H«C1«0« + CHa«,

and attributes the evolution of carbonic oxide observed by Kekul6, to the resolution
of a molecule of chloral into this gas and chloroform :

C*HC1»0 = CO + CHa*.

Chloralide is insoluble in water, and likewise in sulphuric add. It dissolves sparingly
in cold alcohol, but easily in boiling alcohol and in ether. From a hot saturated al-
coholic solution, it is depodted in very delicate white needles ; from a mixture of
alcohol and ether, in stellate groups of rectangular prisms belonging to the monoclinic
system, with oblique terminal faces, and generally having their lateral edces truncated.
They are transparent and colourless, with a glassy lustre, and deave with facility in a
direction parallel to the prismatic faces. Chloralide mdts between 112^ and 114^ C.
to an oily liquid, emitting at the same time an odour like that of chloral : it solidifies
at 108^ (KekuU). Chloralide bums at 200^ (Stadeler) ; at 260<» (KekuU) with
a bright flame, green at the edges.

The alcoholic solution of <£loralide does not predpitate nitrate of silver, but on
adding a drop of ammonia, a precipitate is immediately formed, consisting of chloride
of silver. Coloralide immersed in aqueous potash, is resolved into c^rofprm and
formate of potasdum; but if alcoholic solutions are used, the only products axe formate
and chloride of potassium, these compounds being in fact produced by the action of
alcoholic potash upon chloroform.

The composition of chloralide has been variously stated by different chemists. Sta-
deler, who discovered it, assigned to it the formula C*H*C1*0*, which is confirmed by
the recent experiments of Kekuld. Gerhardt (lyaitif i. 672) proposed the formula
C«H«a'0* ; am el in {Handbook, ix. 207) gave C"H*C1"0», and in the Simdwdrterbuch
dcr Ckemie^ 2<« Aufi. i. 112, the formula (>HCPO' is a&signed to this compound.

CHLORALOIL — CHLORATES. 885

The fbUowing table exhibits the calculated compoaition of chloralidoi aooordixig to
the preceding fonnulflB^ as compared with the results of analysis :

CalemlaUam aeeordhig to : Anaii/Hi:

StSdeler. Gerhardt. Gmelln. Handw. StiUeler. Kekul£.

C*H«a«0« C*H»C1'0« C«H*CI»»0» OHa»0«

c .

. 18-61

18-60

17-98

18-65

18-64

81-64

H . .

. 0-62

0-77

0-39

0-75

0-77

0-72

CI .

. 65-88

64-10

68-62

66-29

66-20

66-00

0 .

. 14-89

16-63

12-44

14-98

100-00 10000 100-00 10000

A prodnct of the action of chlorine npon aloin (p. 148).
ACnia An acid piodnced, together with other snbetanoes, bj
the action of chlorons acid on uric add. It ctyst-allues in nacreons laminae ; forms
ciystaUisable salts with barinm and lead, and a cordj precipitate with sUver-salts.
It gare bj analysis 27'3 per cent C, 8-8 H, 28-1 N, and 11-4 d, numbers whicli
are approximately repiesented by the formula C*^H*^i*Cl*0". (Schiel, Ann. Ch.
Pharm. cxii. 78.)

OH&0»AJmnUi&. G*H'C10 (?) — A heayy liquid produced by the action of
chlorine upon amylie alcohol {q. v,)

■OBAVUte Syn. with PBBcaLOROQUiNOMB, CCl^O*. (See QrxNONS.)

ZO AOZS. Syn. with DiCHLOBOQuiKONijac Aged. (See
QiTiNOxno aoxd).

CH^OMAyriiilMlPB. Syn. with Bicelqboquxnonamids. (See Quinomio
Acid.)

Syn. with BiCKLOBOQUiNOifAicATB or AxMomux.
Syn. with Diohloboquinorio Acm. (See Qunromo
Agd>.)

Syn. with GHLOBOFRBifTLAMiNa. (See PHnrrLAHnnL)
See Amsio Acm (p. 302).
A mineral found on the shores of Isle Boyale, Lake
Superior, in small rounded water-worn pebbles which have come from the tnm. It
has a finely radiated or stellate structure, light bluish-green colour, and pearly lustro
slighUy cliatoyant on the rounded sides. Specific graTily 3-180. Hardness 5-5—6.
A^yses by Whitney :

SiO« A1*0« Fe*0« Ca«0 Na«0 KK) H«0

86-99 25-49 6-48 19-90 8-70 0-40 7*22 - 101-18

87*41 24*25 6-76 2168 488 577 - 100-25

These numbers lead to the formula —

whidi, if H«Ca, Ka and m^\ (Al, Fe), may be reduced to that of an orthosilicatey
(M*OT«)Si«0»+2aq.

The mineral gives off water when heated, and melts with intumescence before the
blowpipe to a greyish blebby ^ass. With borax it forms a transparent fl^ass tinged
with iron; bine witii cobalt s^ution. Dissolyes in hydrochloric acid, with separation
of flocculent silica^ (Dana, ii 315.)

OBSiOXATBS* Chloric acid, HCIO*, is monobasic and forms but one dasa of
salts, haying the general formula MCIO* or M'0.C1*0*. They are all soluble in water,
and are resolved by heat into oxygen and a metallie chloride. (See Chlobio Acid
under Chlobimb, p. 910.)

Chlobatb of ALUMiirinx is a deliquescent salt obtained by precipitating a
solution of silioo-fluoride of aluminium with an equivalent quantity of potassium, and
evaporating the filtrate. (B erz eliu s.)

CKLOBA.TB OF AxxoNiXTX is obtained by adding ammonia or the carbonate to
chloric add ; bjr precipitating an earthy chlorate with carbonate of ammonium ; or by
addinff finely divided chlorate of potassium by small portions to a solution of silioo-
fluoride of ammonium, and filtering. It crystallises in slender needles, has a pungent
taste, explodes when heated, and sometimes, acoordinff to Mitscherlibh, even at ordinaiy
tempemtores. Dissolves easily in water and in alcohol.

Chlobatb of Babxuk, BaClO*. — ^Prepared: 1. By saturating aqueous chloric add
with baryta-water or carbonate of barinm. a. A hot solution of chlorate of potassion^

3l 3

886 CHLORATES.

is precipitated with hydzoflnoolieic acid in slight excess, and the filtrate is saturated
with carbonate of barinm, whereapon chlorate of barium dissolTes, and a small quantit j
of silioo-fluoride of barinm remains behind. The filtered solution yields aystals id
the chlorate by evaporation ^Wheeler, Ann. Ch. Phvs. [2] Tii. 74). h, A aolntion
of 27 pts. chlorate of sodium in 54 pts. water is xnized with a solution of 38 pts. tar-
taric acid in 38 pts. water ; the mixture is thrown into double the quantity of absolute
alcohol; and the liquid, after standing 24 hours, is filtered fix»m the crystalliaed
tartrate of sodium, then saturated with carbonate of barium, &a (Du flos, N. Br. Aicfa.
TtTTiii- 306.) e. Equivalent quantities of chlorate of potassium and acid tartrate of
ammonium (122*6 pts. of the former to 167 of the latter) are dissolved in the smallest
possible quantity of boiling water; the Uquid, after the add tartrate of potassium has
crystallised out, is mixed with an equal quantity of alcohol ; the filtrate decomposed by
boiling with carbonate of barium, &a (L. Thompson, Jahresber. d. Chem. 1847 — 8,

2. By passing chlorine into hot water in which baryta is partly suspended, portly
dissolved. Chloride and chlorate of barium are then formed, the greater part of tlM
chloride is suffered to aystaUise out, and the rest is removed by adding ^osphate of
silver to the solution, in the exact quantity required. (Chenevix, Vauqueliii,
Qmdin'8 Handbook, ii. 161.)

Chlorate of barium forms hydrated prismatic ciystals, 2BaC10' + HK), belonging to
the monoclinic system. Katio of orthodiagonal, dinodiagcmal, and principal axis «■
0*882 : 1 : 1*07. Inclination of axes » 86° 30'; ooP : ooP in the orthodiagonal sec-
tion «97®; [Poo] : [Pto], in the dinodiagonal section =»79° 10'. Ordmaiy com-
bination ooP . [P oo] . — P 00 ; also without —P oo ; also with ooP oo (Kopp, KrysiaUo-
grapkie, p. 304), and less frequentiy with OP (Bammelsberg, P<^. Aon. xc 16).
The crystals are transparent and colourless, give off their water (47*2 per cent^) at
120° C, oxygen at 250° and melt at a temperature above 400° (Wachter, Amu
Ch. Phaim. m. 231 ; Souchay, ibid, di 381). The salt detonates powerAilly with
combustible bodies; produces a green fiame when heated with sulphur (Duflos) ; and
emits a bright flashing light with strong sulphuric acid (Chenevix). It disaolTeB
easily in water, but is insoluble in alcohoL The anhydrous salt dissolves in 4*38
pts. of water at 0° C, iu 2*70 pts. at 20°, in 1*92 pts. at 40°, in 1*29 pts. at 60° in
1*02 pts. at 80° and in 0*79 pts. at 100° ^Eremers, Jaheresber. d. Chem. 1856,
p. 274.JI According to Hutstein (Arch. Pnarm. [2] Ixxvii. 137) it emits light on
crystallising.

Chlobjlts of CAI.0TU1C, CaClO' + HK). — ^Prepared like the barium-salt. Cxys-
tallises in deliquescent rhOmbo'idal prisms, easily soluble in water and alcohcd. They
contain 16*5 p.c. water, melt in their water of crystallisation when gently heated, and
decompose at a higher temperature. (Gm. iii. 212.)

Chlobats of Cobalt, CoClO' + dHK). — Crystallises in cubo-octahedrons. De-
composed by ignition into chlorine, oxygen, and a residue containing oxide andchlorido
of cobalt. (Wachter, Ann. Ch. Pharm Iii. 233.)

Chlobatb of Coppbb, CuC10*-f 3H*0. — A solution of cuprie oxide in chlorie
acid yields green deliquescent octahedrons having a slight add reaction, and soluble
in alcohoL At 100° C. it gives off a few gas-bubbles, and at 260° sufEers further
decomposition, leaving a residue which is insoluble in water but soluble in adds, and
appears to consist of a basic chlorate, inasmuch as its solution in nitric add gives no
predpitate with silver-salts (Wa ch t e r, loe, citA Cuprie chlorate detonates wiui bright
green flame on glowing coals, and is much usea in pyrotechny for tiie production of
green fire.

Chlobatb of Lb ad, 2PbC10' + H*0. — ^Bhomboidal prisms, which become dull
and opaque by exposure to the air ; soluble in water and alcohol but not deliquescent.
When heated, they leave oxychloride of lead containing Pb*C1^0. (Wachter.)

Chlobatb of Lxthiux, 2LiC10* + B?0.— Badiated, very deliquescent mass, melting
at 0° C, and giving off water at 140°, together with oxygen and small quantities of
chlorine. Very soluble in alcohoL (Wachter.)

Chlobatb of Maonbsiux, MgC10*+3H*0. — Crystalline crusty easily soluble
in alcohol, melting at 40° C, and giving off its water at 120°; (Chenevix,
Wachter.)

Chlobatb of Manoanbsb. — Colourless, known only in solution.

Chlobatbs of Mbbcubt. — The merounc salt is obtained by dissolving mercuric
oxide in warm chloric acid (Vauquelin), or by heating mercuric oxide with succes-
sive portions of chlorine-water, filtering from mercuric oxychloride, and concentrating
the filtrate ; mercuric chloride then crvstallises out, while the chlorate remains in
volution (Braamcamp and Siqueira.) Mercuric chlorate forms small deliquescent

CHLORATES. 887

needles, which redden litnuifl, taste like the chloride, and are resolved hv heat into
oxygen gas, mercurons chloride, calomel, and metallio mercuiy. The salt does not
deflagzate on red-hot coals, but sets flre to sulphide of antimony at ordinary tempera-
tures. (GuL Ti 62.)

Mereuro'us Chlorate, Hp'O.ClO' orHhgOlO*. — A solution of mercnious oxide
in chlorie acid yields the salt in beautiful prismatic eiystals, which dissolve in water
and in alcohol, and are resolved bv heat into oxygen, metallic mercurv, and cal6meL
(Wichter.)

OHi.oBATa OF XicxBi., NiClO* -f SHH), crystallises in regular octahedrons of a
deep green colour, deliquescent and soluble in alcohoL When heated, they give off
oxygen and chlorine, and leave a mixture of chloride and oxide of nickel ; at a very
strong red heat, however, nothing but oxide remains behind (WSchter.)

Ghloratb of Potassium, KCIO*, or KO.CIO^. — This salt is an important
artide of manu&cture, being nsed in the preparation of lucifer matches and for other
purposes in the arts. It is prepared, either by passing ehloiine into solution of potash
or carbonate of potassium, whereby chlorate and chloride of potassium are formed,
which are separated by crystallisation, the chlorate being much the less soluble of tiie
two ; or bv aecomppsing chlorate of calcium with sulphate or chloride of potassium.

1. A solution of i pt. hydrate of potassium in 8 pts. water is saturated with dilo-
rine ^s, whereby chloride and hypochlorite of potassium are produced, the liqidd
acquiring strong bleaching properties :

2KH0 + OT - KaO + Ka + H«0.

The liquid is then left to itself for a day, or heated fbr some time to the boiling point,
whereby the hypochlorite is completely resolved into chloride and chlorate :

3KC10 - 2KC1 + KaO».

The ultimate resolt is to convert 6 at hydrate of potasnum, by the action of 6 at.
chlorine, into 1 at. KCIO* and 6 at. KCL It has bieen found that if a solution of
potash either stronger or weaker than that above mentioned be used, part of the
chlorate produced is decomposed into free oxvgen and chloride of potassium.

The sdution, when left to itseli^ deposits tne greater part of the chlorate of potas-
sium in crystals, which may be purified fsoim adhering chloride by recrystaUisation.
The mother-liquor yields by concentration an additions quantity of chlorate, which,
however, is more contaminated with chloride, and requires a greater number of crystal-
lisations to purify it. The test of purity is that the solution is not clouded by a drop
of nitrate ox silver.

Carbonate of potassium may be used for the preparation instead of caustic i)otash.
In that case a considerable ouantity of acid carbonate of potassium is formed in the
early stage of the process, ana crptallises on tiie sides of the vesseb ; but on continuing
the passage of the chlorine, this salt is decomnosed, with evolution of carbonic acid,
the ultimate products being dilorate and chloriae of potassium as before.

Carbonate of potassium may also be used in the solid form, being laid on shelves or
trays in a chamber into which chlorine gas is introduced, just as in the manufificture
of bleaching powder. When the absorption of the chlorine is complete, the product
is dissolved in water, and the chlorate crystallises out, as above described.

2. Hypochlorite of calcium, or bleaching powder, the so-called "chloride of lime"
is made into a " cream " with water, and submitted to continuous boilinff or evapora-
tion to dryness, whereby it is resolved into a mixture of chlorate and chloride of
calcium (p. 910^, a change the completion of which is indicated by the loss of bleach-
ing properties in the mass. The residue, after evaporation, is treated with water, and
cMoride or sulphate of potassium is added, whereoy the chlorate of calcium is de-
composed, with production of chlorate of potassium and chloride or sulphate of calcium.
The chlorate, amounting to about •^ of the weight of chloride of lime employed, is
separated from sulphate of calcium by the insolubility of tiie latter, or fh>m chloride
of calcium by crystallisation.

The process now generally employed consists in a modification of the last, in which
the chloride of lime is formed in the tame operation as tiie chlorate itself, instead of
starting from a previously manufactured blea<^ng powder. Excess of chlorine is
passed into a mixture of 300 pts. caustic lime and 154 of chloride of potassium with
100 water, the operation being pexformed in dose leaden tanks, heated by steam and
provided with agitators. A man-lid, through which the tank can be deansed or
repaired, and one or two wide tubes descending nearly to the bottom of the^ vessel,
through which materials can be introduced, complete the arrangement. During the
action, the temperature rises to about 200^ F. After the completion of this operation,

St. 4

888 CHLORATES.

the liquid is filtered and eraporated nearly to dryness by steam heat ; and the resulting
mass IS redissolyed in hot water and set to czystallise.

The whole of the chloride of calcium remains in the mother-liqnors, and the crystals
of chlorate are rendered fit for the market by slight washing and draining. The reac-
tion upon which this operation depends is represented by the following equation :

KCi + 8Ca«0 + 6C1 « KC10» + 6CaCL

In this process, 154 pts. ECl give more than 200 pts. KCIO', while, by the method
of direct saturation, 116 pts. caustic potash yield only 30 pts. of that salt; at the
same time, no by-product is formed except cluoride oi calfiium. The crystaUisabie
moiher-liquors of this manufacture consist, within 1 or 2 per cent., entirely of this
salt> and may be decomposed either by an addition of sulphate of potassium, or of car-
bonate of sodium. In the former case, sulphate of calcium is precipitated, avail-
able in the manufacture of paper, while chloride of potassium remains in ddta-
tion, and may be recovered by evaporation, to be employed in the preparation of firash
portions of chlorate: in the latter, carbonate of calcium, the "creta praecipitata " of
the druggist, is precipitated, and is largely employed by the pharmaceutist and the
perfumer. Nearly the whole of the waste liqiiors of the English manufiicturer are
oouTerted into the latter product.

Carbonate instead of chloride of potassium may also be mixed with the quick lime :
in that case, on treating the mixture with water, after it has been exposed to the
action of chlozine, the ^ole of the lime remains as carbonate, while chloride and chlo-
rate of potassium are dissolyed. (Gtm. iii 59, Ur^s Dictumary qf ArU^ Manufaetwret
and Mines, i 66.^ .

Properties. — ^Cnlorate of potassium crystaUises in anhydrous six-sided l*wiiTia» mon
rarely in needles. The czTstals belong to the monoclinie system. Batio of ortho-
diagonal, dinodiagonal, and principal axis ■■ 1'360 : 1 : 0*804. Inclination of axes «
70^ ir. Ordinary combination goP. OP . -fP. +2Pap; also twin-oystals. Oesr-
ageparallel to ooP and OP.

Chlorate of potassium is but slightly soluble in cold water. The quantities dissoWed
by 100 pts. of water at dififerent temperatures, as determined by Gay-Lnssac, are given
in the Allowing table :

at 49*06<'C. . . 18*98 pts.

74-390 . 85-40 „

104-7BO . . 60-24 „

It is insoluble in absolute alcohol

Chlorate of potassium is permanent in the air at ordinary temperatures, but is
easily decomposed by heat^ being at first resolyed into chloride and perdilorate
of potassium, with a small quantity of free oxygen : 2KC10' — ECl + EClO* + 0",
while at a higher temperature the whole of the oxygen is giyen o£f (39*15 per cent
of its weight m all), and chloride of potassium remains.

The decomposition is greatly fiAcilit^ed by mixing tiie chlorate with peroxide of
manganese or oxide of copper, the whole of the oxygen of the chlorate being tiien
given off at a low red heat without prerions formation of perchlorate : sudi a mix-
ture is Teiy convenient for the evolution of oxygen. The metallic oxide does not
undergo any alteration, appearing to act merely by dividing the particles of the chlo-
rate and preventing them nom fiising into a mass.

Chlorate of potassium is a powerM oxidising agent, and detonates violently when
mixed with certain combustible bodies and struck or heated. Triturated in a mortar
with>Zot(tfr« of sulphur, it produces a series of sharp detonations. A mixture of the
salt with suipMde of antimony takes fiire when triturated, sometimes with explosion.
A small quantity of the chlonte mixed with phosphorus and struck with a hammer
detonates with a loud report • These combustions are attended with great danger
when large quantities are used.

Chlorate of potassium is decomposed Wadds, with evolution of parozide of chlorine,
ohlorous acid, or hypochlorous add. with strong sulphuric acid, it is resolved into
peroxide of chlorine, perchlorate, and acid sulphate of potassium :

8E010* 4- 2£P80« - 2C10« + EC10« + 2EHS0* + HK)

The decomposition is attended with violent decrepitetion, and sometimes with a flash-
ing light; combustible substences, such as siilphur, phosphorus, metallic sulphides,
arsenic, su^ar, gum, resin, &&, are infiamed by the petoxide of chlorine evolved. A
finely-divided mixture of chlorate of potassium and excess of oystallised oxaUe add
heated to about 70^C. gives off peroxide of chlorine mixed witli carbonic anhydride^
yrhiie chloride and acid oxalate of potassium remain (Calvert and Da vies, Chem,

at Qo C. .

. 8*8 pts.

15-370 .

. 608 „

24-480 .

. 8*44 „

8502<»

. 12-05 „

CHLORATES. 889

8oe. Qu. J. XL 193). The reaction probably takes place in the manner represented by
the equation:

3KaO* + 6C«H»0* - 2C»KH0< + KQ + 2aO» + 8C0« + 6BH).

Chlorate of potassinm boiled with strong nitric acid yields nitrate and perchlorate of
potassium, with erolution of dilorine and oxygen, but no peroxide of chlorine.
(Penny, J. pr. Chem. xxiii. 296):

8KC10» + 6HN0» = 6KN0« + 2KC10* + Cl« + O" + 8H*0.

Dilute nitric acid free from nitrons add does not act on chlorate of potassinm, even
when boiled ; but if it contains nitrous add, or if an^ reducing agent is present,
such as tartaric acid, or arsenions acid, a lower oxide of chlorine is produced.
If the temperature be kept bdow 6^ C. the chief product is chlorous acia, HCIO',
the nitrous acid being at the same time reconyf^rted into nitric add: HKO* + HGIO'
— HNO* + HC10« (Millon, Ann. Ch. Pharm. xlvL 298). Chlorate of potas-
sium heated witii hydrochloric add, yields chloride of potassium, and eives ofif a mix-
ture of peroxide of chlorine and free chlorine, called euchlorincy haying tne proportional
composition of hypochlorous anhydride (CIO* -i- CI' » 2CP0). The reaction is :

4KC10» + 12HCJ1 = 4KC1 + 6H«0 + 8aO» + Cl».

A mixture of chlorate of potassium and hydrochloric add is much used as an oxidising
agent, e. g, for the destruction of organic matter in toxicological inyestigations.

Chlorate of potassium heated vnihpentachloride o/phMpkoruSf giyes off a deep yellow
gas which does not ei^Iode when neated, and when passed into dilute potash-ley,
forms chloride, chlorate, and hypochlorite of potassinm (H. Schiff, Ann. Ch. Pharm.
cyi 116). — Chlorate of potassium distilled with iodine^ giyes off » chloride of iodine,
while chloride and iodate of potassium remain mixed with the excess of chlorate
(Wohler):

KC10« + I + I« = KIO« + I«Cl

Iodic acid added to solution of chlorate of potassiimi, forms crystals of neutral or add
iodate of potassium, while free chloric acid remains in solution. (Serullas.)

Chlorate of potassium is extensively used in the manufacture of ludfer matdies and
fire-works. Ludfer matches which take fire by friction, are tipped with a mixture
of chlorate of potassium, phosphorus, and gluo or gum.

Mixtures for produdng fires of yafious colours, are composed as follows :

Bad Are. Green fire. Purple fire.

Nitrate of strontium 40 pt& Nitrate of barium 77 pts. Oxide of copper 12 pts.

Chlorate of potassium 6 „ Chlor. of potassium 8 „ Chlor. potassium 30 „

Fine charcoal 2 „ Fine charcoal 3 „ —

Sulphur 13 „ Sulphur 13 „ Sulphur 12 „

The following composition is applied to the interior of percussion caps, in quantities
yazying from 0^ to 0*3 of a grain . Chlorate of potassium 26 pts., nitre 30, fhlminate of
mercury 12, sulphur 17, ^und glass 14, gum 1 ( » 100).

Chlorate of potasdum is now extendyefy used as an oxididng agent in heightening
the intensity of ateajn-colours on printed ^oods. It is of constant use in the laboratory
as a source of o:^gen, and is employed in medicine in the treatment of irritation of
the mucous membranea For the manu&cture of gunpowder it is not well adapted,
as the powder made with it, ^duces a yery yiolent explodye force within a small
space oi^y, and bursts the gun instead of propelling the balL

Chlobatb or SiLysB, A^lHO*, — Obtained by dissolying oxide of silyer in
chloric add, or by passing chlorine through water in which the oxide is suspended,
filtering from chlonde of silyer, and eyaporating. It crystallises in white opaque
four-sided prisms, with oblique terminal fiices (Vauquelin), of specific gravity 4'430
(Schroder) ; tastes like the nitrate. It deflagrates brightly on hot cosus, and when
mixed with sulphur, detonates violently on the slightest pressure. Hydrochloric,
nitric, and acetic add, conyert it into chloride, with evolution of oxygen.

Chlobatb of Sodiuh, NaClO'. — This salt maybe prepared by the action of chlo-
rine on solution of soda; but it is difficult to separate from the chloride formed at the
same time ; the separation might, however; be effected by alcohol, which dissolyes the
chlorate much more eamly than the chloride. The salt is likewise obtained by decom-
posing chlorate of potasdum with siHco-fluoride or add tartrate of sodiimi, or chlorate
of ammonium by carbonate of sodium (WittsteinV It might also be prepared by
decomposing chlorate of caldum with carbonate of sooium.

Chlorate of sodium crystallises in regular tetrahedrons, modified by the faces of the
oppodte tetrahedron, also of the cube and rhomboidol dodecahedron : the crystals are

890 CHLOBHYDRIC ACID.

ifomorpluMis with those of btomato of Bodimn. Thejr diaaolyc in 3 times their veig^
of oold water, and in a smaller qnantitj of boiling water ; abo in 34 pta. of 83 per cent.
alcohol at 16^ C. and in a smaller quantity of hot alcohoL

Chlobatb of St&ohtiuii; SidO*. — ^Prepared like the barinm-salL CzystalfiBes
in deUqaesoent needles, or, aoeording to Waehter, in laige pyramidal ccjBtala. It deeom-
poses at the same temperature as the barinm-ealt^ and deflagrates with puple '
on growing coals.

Chlobats or Ubaitium. — ^Ph>toxide of nraninm dissoWes in ehlorie
forming a green solntion, which decomposes spontaneonslj, with evoliition of chlorine and
formation of uranic chloride. (Bammelsberg.)

Chlobatb of Zikc, ZnClO* + 8HK), is obtained by dissolving carbonate of zinc
ormetallicsincinchloricacid,chlorideof zinc being also foimed in the latter case; also
by passing gaseous fluoride of silicon into water in which cazbonate of sine is soapended,
and boiling the filtered liquid with chlorate of potassium. It crystallises, appftroitlj,
in octahedrons, has a yeiy rough taste, and is solable in water and alcohol.

CMXiOXSnraDBA&i Syn. with Momoghlobbthyuc Ethbb. See £ikzi,
OxiDB OF (iL 643).

CB&OSSnXZC or HTBSOGBltOBIC ACIB. HCL— This gas is the only

known compound of chlorine and hydrogen. Its solution in water has been used from
Tery early times, and has receired the names of tpirit of salt, mmrioHe aad^ kydr^-
ehlorie acid, and chlorhydrio aeid. The gas was duscoTeied by Priestley in 1772.

Natural Sources, — Hydrochloric acid gas is erolTed from Tolcanos in eniption,
and the acid solution is sometimes found in' crevices on their slopes. It exists ako,
to the amount of I or 2 pts. in a thousand, in certain rivers of South Amexiea
which have their source in Tolcanie formations.

Formation and Preparation. — 1. Hydrochloric acid is produced by the direct union of
chlorine and hydrogen. A mixture of the two gases in equal volumes, explodes
violently if a burning body is introduced into it^ or an electric sparic passed throng^
it, or if it be exposed to direct sunshine (Gm. iL 319). Ko combination takes place
in the dark, but if the mixture be exposed to difEhsed daylight, the gases combine
gradually. Thus, if two bottles of exactly equal capacity and fitted to one anodier by
grinding, are filled by displacement with chlorine and hydrogen respectivelj, then
adapted to each other by their mouths, the chlorine-vessel b^ng placed uppermost,
and set aside for some hours in a light situation, but not in direct sunshine, the green
colour of the chlorine will gradually disappear almost entirely, and a few minates*
exposure to sunshine will complete the combination. If the two bottles be th^i sepa-
rated under mercury, each will be found ftill of hydrochloric acid gas, no gas escaping
and no rising of the mercury taking place in eitner bottle, showing that the dilorine
and hydrogen have combined without expansion or contraction. If a jet of water
tiuflsd with blue litmus be thrown up into either of the bottles, the gas will be rapidly
and completely absorbed, while the litmus solution will assume a bright red o^oor.
Any bleaching of the litmus would indicate free chlorine ; any unabsorbed gas, the
presence of free hydrogen ; in this manner, an excess of either gas in the original
mixture may be detect^

2. Hydrochloric acid gas is usually prepared by the action of sulphuric acid on fused
chloride of sodium. There is at first a copious effervescence, which, after some time,
it may be neoessazy to revive by the application of a gentle heat The reaction is :

NaCl + H*SO« - NaHSO* + HCL

The gas must be collected over the mercurial trough, as it is rapidly absorbed by
water.

3. Hydrochloric add mav also be produced by the action of water on certain
chlorides. The two chloriaes of phosphorus are decomposed immediately and com-
pletely by mixture with an excess of water, with formation of phosphorous and phos-
phoric add respectively, thus :

PC1» + 3H*0 » H*PO« + 8Ha ./

pa» + 4H«o - BfF0**+ fiHay

The two chlorides of antimony are decomposed more slowly. Trichloride of bismnth
requires prolonged treatment with water to effect its thorough decomposition, which,
however, takes place readily at a boiling temperature. Stannic chloride, even at a
boiling temperature, is decomposed very imperfectly. The seequichloride of aluminium
fmd protochloride of magnesium, ^., are decomposed by steam, with evolution of
hydrochloric add, at temperatures considerably below redness :

2A1K!1» + 3H»0 a A1*0« + 6HCL
2MgCl + H«0 « Mg«0 + 2Ha

CHLORHYDRIC ACID. 891

•

Horeorer, hydrochlorio acid reiralts from the reaction of chloride of phosphonis,
chloride of antimony, and some other chlorides, usually hyperchlorides, not only with
water, but with most oz^hydrogenised compounds (pp. 897 — 900). ^

4. Hydrochloric acid is a constant attendant upon the direct action of chlorine on
hydiogenised substances. A solution of 6hlorine in water is converted, when exposed
to light, into hydrochloric and hypochlorons adds : CP -i- HK) » HGl + HGIO. Chlorine
instantly decomposes sulphydric acid, with formation of hydrochloric acid and separa-
tion of sulphur : CP + H*S » 2HG1 + S. Phosphoretted and arsenetted hydrogen are
likewise decomposed by chlorine, with formation of hydrochlorio acid. Numerous
organic compounds also are decomposed by chlorine, one portion of that element
TiTiiting with the whole or with part of the hydrogen, and an equal portion taking the
place of the hydrogen thus remoyed : e, g,

C*H*0« + 8a« - C^CIW + 3Ha
Acetic Trichlor-

acid. acetic

add.

Hydrochloric acid also results from the iuTerse action of hydrogen upon a chlorine
compound, as when ignited chloride of nickel is subjected to a current of hydrogen,
thus: NiCl + H -HCn + Ni.

Properties. — ^Hydrochloric acid is a colourless gas, having a strong add taste, and
a pungent irritating odour. Its specific gravity (air « 1) is, according to the deter-
mination of Blot and Ghiy-Lussac, 1*27 ; by calculation, it is — ^^ x 0*0693—1*265.

It forms opaque white fumes in the air, owing to its union with, and condensation of, the
atmospheric moisture. In perfectly diy air these fumes are not produced. The gas is
extremely soluble in water. When a fiask of dry hydrochloric add is opened under
water, the whole of the gas is absorbed in an instant, and the flask not unfrequently
broken by the violent rush of liquid. At mean temperature (15° C.) water dissolves
alx>ut 468 times its volume of the gas (see Gases, A^OBPnoN of). At the tempe-
rature of 10^, under a pressure of 40 atmospheres, hvdrochloric add is condensed into
a colourless liquid, having a specific gravity^ 1*27. It has never been solidified. Hy-
drochlorio add is not inflammable, and extinguishes most bximing bodies, but when a
piece of potassium is introduced by means of an iron wire into a tube ftill of the gas
retained over mercury, and is then heated to redness by a spirit-lamp applied exter-
nally, it undergoes combustion, unites with the chlorine, and leaves the hydrogen,
which is eventufdly found to occupy exactly one half the volume of the origmal gas :
HCl + K - KCl + H.

Solution of hydrochlorio acid is usually made from common salt and sulphuric add
diluted with about two-thirds its bulk of water. The reaction is effected in a retort
to which a gentle heat is applied, and the evolved sas is condensed in a vessel or
series of venels of distilled water. The condensing Uquid increases oonsiderablv in
bulk, and may eventually be made to acouire a specific gavity of 1*21, under which
circumstances it consists of one atom of hydrochloric .add, Hd, dissolved in three atoms
of water, HK). Solution of hydrochloric add has usually a specific ^vity of 1*162,
and then consists of one atom of hydrochlorio add HCl, dissolved in four atoms of
water, H*0.

Commercial muriatic add is made by heating in iron cylinders two proportions of
common salt, with as much brown sulphuric add as contains one proportion of
real add, and condensing the evolved w in water contained in a series of stoneware
Woulfe's bottles. The reaction is : H'^SO^ -f 2NaCl - Na*SO« -t- 2HCL For detaOs,
see Ur^$ JHetionary of Arts, Manufactures and Mines, ii. 481. — ^Pelouze et Fr^my,
IVaiti ds ChimisffhUrale, 8>« ^ L 436.— Payen, JPriois de Chimie industrials, 4"« ^d.
L264.)

The commercial add, which frequently contains, as impurities, sulphurous add,
arsenious add, sesquichloride of iron, stannic chloride, ana even free chlorine, may
be partly purified by dilution and redistillation. A pure solution of hydrochloric add
is usually colourless, but when in lai^e quantities, has a very pale yellowish green tint.
The slight yellow colour of miscalled pure add is geneRuly due to the presence of
free chlorine, but the bright deep yellow of the commercial add results from the
presence of chloride of iron. The introduction of a small quantity of oiganic matter,
as by contact with a cork, will likewise impart a yellow colour to hydrochloric add
othcorwise pure.

A strong solution of hvdrochloric add evolves fumes on exposure to air. ^When
boiled, it gives off hydrochloric add gas, until the temperature slightiy exceeds 100^ C,
when there distils over a diluted solution of the add, having a specific gravity of 1*1,
and consisting of 1 atom of hydrochloric add, HCl, dissolved in 8 atoms of water, HH>.

892

CHLORHYDRIC ACID.

From the experiments of Boscoe, hofwerer (Chem. Soe. Qn. J. xiii 156), it
that the composition of aqneoufl hydrochloric acid (and of other aqueons acids)» of
constant boiUng point, varies vith the uressnre, and that there ezista for each px«s-
sore a ooirespondmg aqneoos acid, which undergoes no change in composition wlien
distilled nnder this pressure, and therefore has a constant boiling point. In table A,
oolnmn P shows the pressure in metres of mercmy under -vdiich aqueous hydiochlone
acid most be distilled to attain the composition given in the next column.

Tablb a. — Percentage of HCl m aqueoue Hydroehiorie Acid hoUing wader different

Preseuree,

Pftrcentage

Percentage

Perccotage

of HCi.

of HCI.

006

23-2

0-7

20-4

1-3

19-3

2-0

18-5

22-9

0-76

2014

1-4

191

18*4

0-2

22-3

0*8

20-2

19-0

2-3

18-3

0*3

21-8

0-9

19-9

1-6

18-9

2*4

181

0-4

21-4

19-7

1-7

18-8

2-6

18^

211

19-5

1-8

187

0-6

20-7

1-2

19-4

1-9

18*6

The add which boils constantly under the pressure 076 met, and contains 20^
per cent. HCI, is the hydrate above mentioned, HC1.8H'0. The table shows that the
percentage of HCI in the aqueous add of constant boiling point, diminiBhrn with in-
crease of pressure.

When aqueons hydrochloric add is vaporised by passing a current of dzy air through
it at a gitfen temperature, a point is likewise reached beyond which no deoompositioa
occurs. In Table B the first column gives the temperatures, the second the percentage
of HCI contained in the acid, unalterable at the corresponding temperature.

Tabls B. — PercerUage of HCI in Aqueout ffgdroehlorie Add of constant composition

at different Temperatures.

Percentage of
HCI.

Percentage of
UCl.

Percentage <rf
HCL

Percentage
of HCL

O^C.

250

30«C.

241

60° C.

230

90OC.

21*4

24-9

23-9

22*8

211

247

23-8

22-6

100

207

24-6

23-6

22-3

24-4

23-4

220

24-3

23-2

217

The spedfic gravity of aqueous hydrodiloric add, of various degrees of concentration
has been determined by Ure and by E. Davy. The results are given in Tables G
and D; it will be observed that the spedfic gravities as determined by DaTy are
rather lower for each percentage of HCI than those of Ure.

Tablb C.^Percentage of HCI in Aqueous Hydrochloric Acid at 25** C. (77<> F.)

according to R Davy.

Sp. Gr.

HCl.

8p. Gr.

HCI.

Sp. Gr.

HCI.

Sp. Or.

Ha.

1-21

42-43

116

82-32

1-11

22-22

106

1212

1-20

40-80

1-15

30-30

110

20-20

1-05

1010

119

38-38

1-14

28-28

109

1818

104

808

118

36-36

1-13

26-26

1-08

16-16

103

606

1-17

34-34

112

24-24

107

14-14

1-02

4-04

1-01

2-02

CHLOBHYDRIC ACID — CHLORHTDBINS.

893

Tabls D.~

CompQ9itum of Aqueous Hydroehlorie Acid aooording to Ure.

Add

ofSp.
gr.l<9.

SpcdBc
Onrltj,

Cblo-
percant.

percoDt.

Add
of ip.

8p«dlle
GraTlty.

Cblo-

rtoo.

peroent.

HCl.

percent.

Add

off p.

gr.l-S.

Spedflc
GraTity.

Chlo«

rlae.

per eent

Ha.
per cent.

100

1*2000

80-676

40*777

1-1328

26-186

26-013

1*0637

12-607

13-040

1-1082

80*278

40*360

1-1308

26-780

26*606

1-0617

12-300

12-641

11064

88*882

30-061

1-1287

26-302

26-008

1-0607

11*003

12-233

1-1046

38-486

30-664

1*1267

24-006

26-600

1-0677

11-606

11-825

1-1028

38-080

30-146

1-1247

24-600

26-282

1-0667

11-100

11-418

1-1010

37-602

38-738

1-1226

24-202

24-874

1*0637

10-712

11010

1-1808

37-206

38*330

1-1206

23-806

24-466

1-0617

10-316

10-602

1-1876

36000

37-023

1-1186

23-408

24068

1-0407

0-010

10104

11867

36-603

37-616

1-1164

23-012

23-060

1-0477

0-622

0-786

1-1846

36107

37-108

1-1143

22-616

23-242

1-0467

0-126

0-370

1-1822

36-707

36-700

1-1123

22-218

22-834

1-0437

8-720

0-071

1-1802

36-310

36-202

1-1102

21-822

22-426

1-0417

8-332

8-663

1-1782

34-013

36-884

1-1082

21-426

22010

1-0307

7035

8-166

11762

34-617

36-476

1-1061

21-028

21-611

1-0377

7-538

7-747

11741

34-121

36068

1-1041

20-632

21-203

1-0367

7-141

7-340

1-1721

33-724

34-660

1-1020

20-236

20-706

1-0337

6-745

7-032

1-1701

33-328

34-262

1-1000

10-837

20-388

1-0318

6-348

6-524

1-1681

82-031

33-846

1-0080

10-440

10-080

10208

6-061

6-116

11661

32-636

33-437

1-0060

10-044

10-672

1-0270

6-664

6-700

1-1641

32136

33-020

1*0030

18-647

10-166

1-0260

6-158

6-301

1-1620

31-746

32-621

1*0010

18-260

18-767

1-0230

4-762

6-803

1-1600

31-343

32-213

1-0800

17-864

18-360

1-0220

4-366

4-486

1-1678

30046

31-806

1-0870

17-467

17-041

1*0200

3-068

4-078

11667

30-660

81-308

1-0860

17-060

17-634

1*0180

3-671

4*670

1-1636

30*163

30-000

1-0838

16-664

17-126

1*0160

3-174

8*262

1-1616

20-767

30-682

1-0818

16-267

16-718

1-0140

2-778

3-854

1*1404

20-361

30-174

1-0708

16-870

16-310

1-0120

2-381

3*447

1-1473

28-064

30-767

1-0778

16-474

16-002

1-0100

1-084

2*030

11462

28-667

20-360

10768

16-077

16-404

1-0080

1*688

2-631

11481

28171

28061

10738

14-680

15087

1-0060

1101

1-224

11410

27*772

28-644

10718

14-284

14-670

1-0040

0*705

1-816

11380

27-376

28-186

10607

13-887

14*271

10020

0-307

1-408

1-1360

26070

27-728

10677

13-400

13-863

1-1340

26-683

27-321

1-0667

13-004

13-466

Aqaeous hydrochloric acid poflsesseB powerftd add properties, reddens litmus, tastes
intensely sour, effervesces with carbonates, and dissolyes many metals with evolution
of hydrogen. It does not bleach vegetable colours or dissolve gold leaf. W. O.

CBXiOBBTBSIO BTHAIUi. See Chlobidbs of Aloohol-Radiolbs (p. 807).

OB&OSBTBaz»i. (Berthelot, Ann. Ch. Phys. [31 xli. 206.^Berthelot
and Do Luca, ibid, zlviii. 304; liL 483.) — These com^unos, which are precisely
analogous to the bromhydrins (p. 667), are the chlorhydnc ethers of glycerin, and may
be regarded as derived therefrom by the substitution of one or more atoms of chlorine
for an equivalent quantity of peroxide of hydrogen. They are produced, either by
the action of hydrochloric acid or of the chlorides of phosphorus on glycerin ; the
latter method does not however yield very good products.

Monochlorhydrin, C«H»aO« «. (C«H*)"'-(H0)«.C1, is obtained by saturating
gently heated glycerin with hydrochloric acid gas ; then keeping the liquid at 100^ C. for
some hours; saturating with carbonate of sodium; agitating with ether; distilling the
residue left after evaporation of the ether ; and again treating it with carbonate of
sodium and ether. It is a neutral oil, having a fresh e^ereal o£>ur and a sweet taste,
with pungent after-taste. Specific gravity 1-3 1. It remains perfectly fluid at — 36° C. ;
boils at 227^; bums with a white^ green-edged flame, emitting nydrochloric add!
Oxide of lead saponifies it slowly. It does not immediately precipitate nitrate of
silver. It mixes with its own bulk of water. With 8 or 10 times its bulk of water, it
forms a very stable emulsion. It also mixes with ether. •

Liehlorhydrin. CHHnH) » rC»H»)'".HO.Cl«, is obtained by heating a solution of
glycerin in 10 or 12 times its weight of fuming hydrochloric acid, to 100° C. for threo
or four days, purifying the product with carbonate of sodium and ether as above, and

894 CHLORHYDROPHENIDE — CHLORIDES.

eTBporatixiff, fint over the water-batli, then in vacao. It is a neatral oil, baTing aa
ethereal o<£>iir. Specific graTily l'd7. It boils at 178^ C. ; remains quite finid at — Z6^;
buma like the preceding ; ia easily decomposed by potash, yielding chloride of potas-
sium and glycerin ; mixes with e&er, but does not form a stable e9a.nl8ion with water.
Trichlorhydrin; Trichloride of Olyaeryl, CHHTl*.— Produced by the action at
pentachloride of phosphorus on diehlorhydrin :

(yRKJLH) + PC1» - PC1«0 + Ha + C»H»C1».

It is a neutral liquid, much more stable than tribromhydrin. Volatilises at about
166^ C. (Berthelot and De Luca.)

Epiehlorkydrin. Oxychloride of Glyceryl 0^"G10.— Obtained by tresfcine di-
ehlorhydrin with hydrochloric acid gas, or with the tuning acid. Neutral oa^ re-
sembling diehlorhydrin. . Distils between 120^ and 130^ 0. (Berthelot)

Epidichlorhydrin, Dichhride of GlyceryUne, C^^Cl'. — Produced m small
quantity in the preparation of trichlorhydrin and bromodichloriiydrin, probably by a
secondary reaction, inasmuch as it difl&ra from diehlorhydrin by HK), and frcnn tri-
chlorhydrin by HCL It is isolated and purified by repeated finictional distillarifiin.
Keutru liquid, volatile at about 120^ 0. Treated with moist oxide of silver, it alovlj
reproduces glycerin. (Berthelot and De Luca.)

Dihromoohlorhydrin^ C'H'Br'CL — ^Ph>duced by the action of pentachloride ct
phosphorus on dibromhydrm. Neutral liquid, volatile at about 200^ G. With moist
oxide of silver at 100^, it slowly reproduces glycerin. It is isomeric with dibromide
of chlorotritylene, CBPClBr*.

Bromodiehlorhydrin^ CH'BrCl*. — ^Produced by the action of pentabiomide of
phosphorus on diehlorhydrin. Neutral liquid, volatile at about 176^ C. Isomeric with
didiloride of bromotritylene.

With moist oxide of silver at 100^, it slowly reproduces glycerin; at the same time,
however, a small quantity of carbonic anhydride is formed by oxidation, together with
crystalline scales, which appear to be propionate of silver :

C«H»Bra« + 8H«0 » C«H«0» + 2Ha + HBr

Olyeerln.

and CJ»H»Bra' + 2HH) - C»H«0« + 2Ha + HBr

Propionic
acid.

For the Aobtoghlobhtdbins, see p. 26 ; Bbmzoohlobetdbinb (p. 647.)

(yhloride of PhenyL (See PEBxmi.)

A name applied by Mulder (J. pr. Chem.
zviL 316), to the precipitate formed by hydrochloric add in a solution of albumin, said
by Mulder to contain 8-7 per cent of hydrochloric add. It is probably however
nothing but albumin.

vbjUOXXBBS. The term chloride is applied to all compounds of chlorine which
may be derived £rom one or more atoms of hydrochloric add, H'dl", by the substita-
tion of a metal or other radide (which may itself contain dilorine), for an equivalent
quantity of hydrogen. Those which are volatile contain, in two volumes of vaponr,
1, 2, 3, &C. atoms of chlorine, according as the radide with which the chlorine is aa*
sodated is mono-, di-, tri-atomic, &&*, thus :

2 vol chloride of ethyl, OH*. CJl, contain I at dilorine
„ „ sulphuiyl, (S0»)''.C1« „ 2

„ „ boron, B.Ca* „ 8 „

i» t, silidum, §iCl^ „ 4 „

Chlorides may be conveniently divided into the following groups, each of which
contains compounds derived &om one or more atoms of hydrochloric add.

a, Metalllo^ Cblorldes. Chlorine combines with all metals, the number of
chlorine-atoms in the resulting molecule varying from 1 to 7*

a. Chlorides^ with one atom of chlorine, formed on the type of the einyU atom of hy-
drochloric acid, HCl, namely, protochlorides, MCI, and hemichlorides, or sub-
chlorides, M^CL The greater number of metals form protochlorides, all indeed,
except aluminium, antimony, arsenic, bismuth, t^Mif^tlnni^ titanium, tungsten, vanadium
and zirconium. The protochlorides are all more or less soluble in water, except those
of silver and platinum, which are quite insoluble. The protochlorides of gold, platinum,

■ If, howerer, fhe radicle contains chlorine, thii statement mnit be understood as applying only to the
portion of chlorine which is not thiu Included, and Is remorable by water or by aqueous potash : for
example, 2 vols, chloride of trichloracetyl, C>CPO.CI contain 4 atoms of chlorine; but only one of these
is remoTable by water, the compound/treated with water, yielding hydrochloric add and trichloraoetla
acid (C«Cl»O.Cl + H«0 ■■ HCl + CCPO.H.O).

CHLORIDES. 895

and palladium, are completely decomposed at a red heat ; that of copper, partially.
The other protochl^rides melt when heated, and yolatilise unchanged at higher tempe-
ratures. Seyeral hydnited protodilorides, those of magnesium and zinc, for instance,
are resolved more or less completely by heat into metallic oxide and hydrochloric add.
The fused protochlorides are electrolytic.

The heTM-^UoTtUo metals^ especially copper and mereuiy, fbrm subchlorides, con-
taining, «. ff. Cu'Cl, Hg*GL They are insoluble in water, and xmder certain circumstancee
manifest a tendency to bseak up into metal and protochloride.

0, Chlorides with two atoms of chlorine, formed on the type H'Cl*, ncemdy. Bi-
chlorides, M'Gl'. The metals which form dichlorides, are molybdenum, palladium,
platinum, teUuiium, tin, titanium, tungsten, and vanadium. The dichlorides of platinum
and palladium give off at a gentle heat one half, and at a stronger heat the whole of
their chlorina The others are easily yolatHe.

7. Chlorides with three atoms of chlorine, formed on the type H'Gl', namely, Tri-
chlorides, M'^a*, and sesquichlorides, (M»rCl«.— The metals which form tri-
chlorides are antimony, arsenic, bismuth, gold, molybdenum, tungsten, and vanadium.
Trichloride of gold is reduced at a gent& heat to protochloride, which at a higher
temperature is resolved into chlorine and metal. The rest volatilise unchanged. The
trichlorides of antimony and bismuth are very ftisible solids ; the rest are liquids.
The volfl^e trichlorides are decomposed by water, yielding hydrochloric acid and an
oxychloride, thus : BiC51« + HK) - 2HC1 + BiClO.

The sesqidchlorides are formed from a triple molecule of hydrochloric acid, by the
substitution of 2 at of a sesqui-atomio metal for 3 at. hydrogen ; the metals which
form them are aluminiuniY cerium (?), chromium, iron, and manganese. The cerium
and nuinganese compounds are known only as hydrates ; the rest are fusible and volatile
solids. They are all soluble in water, and are-^>artially decomposed by heat.

8. Chlorides with four atoms of chlorine, formed on the type H^C1\ namely, Tetra-
chlorides. These are formed only by the metals tin, titanium, and zirconium.
The first two are liquids, the third solid: they are all volatile, and their general be-
hariour shows that two of the dilorine-atoms are retained less forcibly than the other
two. The tetrachlorides of tin and titanium are soluble in water ; the zirconium-
oompound is decomposed bv water.

c. Chloride with 5 at. cAlonfM.-— Pentachloride of antimony, SbCl*. Volatile liquid,
decomposed by water.

There are no hexaehlorides known, and only one heptachloride, namely, the hepta-
chLoride of maneanese, ICn'Cl'.

FormeOion of Metallic Chlorides, — ^Chlorides are generally prepared by one or other
of the following processes, a. Sy acting upon the metal with chlorine gas. This
method is frequenuy employed for the preparation of anhydrous chlOrides. The penta-
chloride of antimony and protochloride of copper are examples of chlorides sometimes
produced in this manner. The chlorides of ^Id and platinum are usually prepared by
acting upon the metals with nascent chlorine, developed by the mutaal action of
hydrochloric and nitric adds. Sometimes, on the other nand, the metal is in a nascent
state, as when titanic chloride is formed by p^i^i; a current of chlorine over a heated
mixture of charcoal and titanic anhydrida The chlorides of aluminium and chromium
may be obtcdned by dmilar processes.

/§. Chlorine gas, by its action upon metallic oxides, drives out the oxygen, and
unites with the respective metals to form chlorides. This reaction sometimes takes
place at ordinary temperatures, as is the case with oxide of silver; sometimes only at
a red heat, as is the ease with the oxides of the alkali- and alkaline earth-metals. The
hydrates and carbonates of these last metals, when dissolved or suspended in hot
water and treated with excess of chlorine, are converted, chiefly into duoridefl^ partly
into chlorates.

7. Many metallic chlorides are prepared by acting upon the metals with hydrochloric
add. Zinc, cadmium, iron, nidcel, cobalt, and tin dissolve readily in hydrochloric
acid, with liberation of hydrogen ; copper only in the strong boiung add ; silver,
mercury, palladium, platinum, and gold, not at all. Sometimes the metal is substi-
tuted, not for hydrogen, but for some other metal. Stannous chloride, for instance, is
frequently made by distilling metallic tin with mercuric chloride, thus : 2HgCl + Sn —
SnCl« + Hg*.

8. Or the oxide, hydrate, or carbonate of metal may be dissolved in hydrochloric
acid. In this way the hydrated protochloride of copper and sesquichlonde of iron
are usually made :

eu*0 + 2Ha - HK) + 2CuCL
Fe«H»0» + 3Ha - 3H*0 + FeKJl*.

VTith a peroxide, the reaction is accompanied by an evolution of chloxine, thus :

Pb«0« + 4HC1 « 2H«0 + 2PbCl + Cl».

896 CHLORIDES.

c. Chloride of silTcr and mereiuoM diloiide^ vliidi axe inaolnble in water, and
chloride of lead, which ia hot maringhf loliible, axe eaailjfbnned bypcedpitating anj
of the cuticqwDdiDg aoLable aatta witii s aofaible chloride^ thna:

NaCl + AgNO* - Aga ^ NaNO*.

DeoompomUkm*, — 1. The actioii of heat upon cUoridea haa been alieady notieed,
Moetprotochloridea Tolatiliae at Ug^temperataree^ without deeoni^^ thehiglier

chlondea give off part of their chlnine when heated. — %, Some ehloridea which resist
the action of heat alone are decom]^oaed by ignition in the air, fielding metallic oodUies
and free chlorine : thisiathecaaewith the ehloridea of iron and manganese; botmoet
protochkridea remain nndecompoaed, eyen in this case. — 8. All y^^Mm chlaridea, ex-
cepting thoae of the alkali-metala and earth-metala, are deoompoaed at a red heat "hj
h^rogen ^aa^ with £armation of hjdrochlorie add : in this waj, metallic iron maj be
obtained m fine cubical cryatala. Chloride of ailTcr placed in contact with meteDie
sine or iron, nnder dilate aulphnric or hydrochloric add, ia reduced to the w«<»»*nii»
state by the ncuotwt h^rogen, — i. Metallic chkridea, which are not decomposed by
heat alone^ likewise roust the action of cAorcoo/ at a white heat, bat if agveouc eqpgar
is likewiae present^ deoompodtion takea place, the metal being redneed, and hydn>>
chloric add formed, together with an oxide of carbon, e,g. :

2Aga 4- B'O -¥ 0 ^ A^ ^ 2Ha •»- CO.

— 6. Metallic ehloridea are not deoompoaed by heating with ndpkur, hoX pkotpkomM
deoompoaea aerenl of them. — 6. Those metaUie ehloridea which are not decomposed
by heat alone, likewiae reaist deoompodtion when heated to whiteneas with borie «■<-
hydHde, at MtHae md^ride; bntif water is preaent, hydrochloric add iaerolTed,
and a borate or aflicate of the metal ia produced. Vapour olsuipkurie anl^^dridt,
however, deoompoaes certain metallic ehloridea, a sulphate being formed, and a mixture
of equal Tolumea of chlorine and sulphurous anhydride evolTcd, e,g.z

2Naa + 2S0« « Na«SO« + S0« + Q*.

— 7. Sulpkurie, pkotpkoric, horie^ and artemc acids, deooo^ose moat mftfalH^ ehloridea,
sometimes at orainazy, aometimea at higher temperatuzea. — 8. All metallic ehloridea
heated with peroxids of lead or manganae and swpkuric aeid, give off dilorine^ e. y. :

2NaCl + MnK)» + 2H«S0* « Na«SO« + Mn>SO« + 2IP0 + Cl«.

— 9. Distilled with mlpkurio aeid and chrcmaie of poiasntan, they yidd a dark
bluish-red distillate of cblozo-chromic add.— 10. Some metallic chlondea are deoom-
posed by water, forming hydrochloric add and an ozycUoride, e.a. : BiCl' + HK) -«
2HC1 + BiClO. The chlorides of antimony and stannous chloriae are decomposed in
a similar manner.->ll. All soluble chlorides gire with solution of nitrate of silver, a
white predpitate d chloride of silver, easily soluble in ammonia, insoluble in nitric
add. With mercurous nitrate, they yidd a white curdy predpitate of mercniona
chloride, blackened by ammonia ; and with lead-salts, not too dilute, a white crys-
talline predpitate of chloride of lead, soluble in excess of water.

Comiinations. — ^Metallic chlorides unite with esdi other and with the ehloridea of
the non-metallic dements, foryiing such compounds as diloromercuiate of potassium,
KCLE^Cl, chloroplatinate of sodium, NaCLPtCl*, chloriodate of potassium, KCLId',
&C. ^ey also combine with oxides and sulphides, forming oxycnlorides and sulpho-
chlorides. Metallic chlorides likewise combine in defi^te proportions with am-
monia and orgumc bases ; the chlorides of platinum form with ammonia the compounds
NH».PtCl, 2NH«.PtCl, NH».PtCl« and 2NH«.RC1« ; mercuric chloride forms with
phenylamine the compound C^'N.HgCl; with chinoline, C*H'N.2Hc<)l, dec Many
of these compounds may be regarded as chlorides of metalloldal radides, formed on
the ammonium type : thus, ammonio-protochloride of platinum, NH' JHCl » chloride
of platammonium (NH'Pt).01.

Many metallic dilorides are soluble in alcohol, ether, volatile oils, &c.

b, Obloiidas of Ihrgano-metalllo Badtelaa (induding Phosphorus-bases). —
These compounds, which bear considerable resemblance tothe aimple metallic chlo-
rides, are produced, either by the direct union of chlorine with the organo-metallic
radicle, or by the action of hydrochloric add on the oxide or hydrate of that radide.
Some of them are volatile hquids ; others crystalline solids. They contain 1, 2, 3,
or 4 at. of chlorine associated with 1 molecule of the organo-metallic radicle, thoso
which contain an even number of atoms of alcohol-radide forming mono- and tri-
chlorides, while those which contain an uneven number of atoms of alcohol-radide
form di- and tetrachlorides, thus :

Arsen-monomethyl fomiR AsMeCl'

and ArMoCI^

Arsen-dimethyl „ AsMe'Cl

„ ArMcKJI*

Stib-triethyl „ SbMe"Cl«

Stib-tetramethyliuto „ SbMe*Cl

CHLORIDES. 897

All these oomponndB may be regarded as deriyed from a moleeale of tri- or penta-
chloride of arsenic or aDtiinony by tbe substitution of an aloohol-radide for an equiva*
lent quantity of chlorine (pp. 339, 397, 411).

8. Oliloridas of Aleoliol^Uidlelea. Hvdroehlorio or Chlorhydrio Ethers. —
Theise compounds may be regarded as deriyed from hydrochloric acid in a similar
manner to the metallic chlorides, or from the corresponding alcohols by the substitation
of chlorine for an equiyalent quantity of peroxide of hydrogen, e,ff. :

Chloride of ethyl, C*H\C1 from Ethylio alcohol, 0*H*.HO
CJhloride of ethylene, 0«H«.C1« „ Glycol, 0«H*.(HO)«

Chloride of ^yceiyl, C»H».C1» „ Glycerin, C«H».(HO)»

a. The numatomie aicoholio eJdoridea are obtained :

1. By the action of hydrochloric add on the alcohols :

C*H».H.O + HQ - HH) + C^».a

2. By the action of the chlorides of phosphorus, or of oxyoUoride of phosphorus, on
the alcohols :

3(C«H».H.O) + Pa« - H»PO» + 8C«H»C1.

8(C»H».K0) + PCIK) - H*PO* + 8C«HKJ1.

3. By the action of chlorine on the coiresponding hydrides. This reaction has been
obeeryed only in the case of hydride of benzyl (p. 573).

Most of these monatomio chlorides are liquids more Tolatile than the corresponding
alcohols : one, y iz. chloride of methyl, is gaseous at ordinary temperatures, and chloride
of oetyl is soUd. Treated with alcoholic potash, they yield chloride of potassium and

an alcohol :

C*H»C1 + KHO - Ka + 0*BP.H.O

When recently prepared, they do not precipitate nitrate of silyer immediately ; but
when they are heated with it in sealed tubes, a slow precipitation takes plat^ Sodium
at ordinary temperatures decomposes them, with formation of chloride of sodium and
an aloohol-radiele :

2C^"C1 + Na« - 2Na01 + C"H»'.0«H".

Chloride of Octyl.

octyl.

But if heat be applied, the sodium assumes a yiolet tint and swells up considerably.
The liquid then becomes hot ; hydrogen is eyolyed ; the yiolet colour cusappears ; and
a pasty mass is ultimately obtained, consisting of chloride of sodium and as oil, which
is the corresponding hydrocarbon, C*H^ : thus, with chloride of octyl :

2(CTa".Cl) + Na« - 2(C«H»«Na.a) + HH
and: C"H»*Ntt.Cl - NaCl + 0»H'«.

violet tubiUnce. Octyleoe.

The same yiolet substance is produced by the simultaneous action of chlorine and
sodium on octylene. It quickly turns white in contact with the air, yidding soda and
chloride of sodium, and is quickly decomposed by water, alcohol, and otiier liquids
containing oxygen (B oui s, N. Ann. Chim. Phys. xliy. 1 14). A similar yiolet substance
is formed by the action of potassium on chloride of phenyL ^

/S. The diatomic alcoholic chlorides are produced : 1. By the direct union of chlorine
with the corresponding diatomic hydrocarbons, e,a. chloride of ethylene, chloride of
tetiTlene, &c. — 2. By me action of pentachloride of phosphorus on the ooziesponding
aloonols, e, g, :

C«H^H«.0* + 2PC1» - C«H^a« + 2P0C1* + 2Ha

Gljcol. Chlnride of

ethylene.

Two series of these chlorides are known, containing the radicles C"H!'', homologous
with ethylene, and C"H^~*, homologous with benxylene.

The chlorides C*H!^C1', are li<^i^ds, for the most part yolatile without decomposition.
They are decomposed by chlonne, yielding substitution-products. Heated with al-
coholic potash, they yield chloride of potassium, and the chloride of an aldehyde-
radicle :

C«H*a« + KHO - C«H»C1 + KCl + HK).

Sulphide of potassium simply conyerts them into sulphides of diatomic aleohol'-
radides:

C«H*C1« + K«8 - 2KC1 + 0«H*a

Heated with ammonia in sealed tubes, they appear to yield the same products as tht
corresponding bromides, yiz. diamines containing 1, 2, or 3 at. of the radicles OH> ;
but the reactions haye not been so much examined as those of the bromides. (See
Ammontuic-Basbs, p. 196 ; also ETHTiJori-BAsss.)
Vol. I. 8 M

898 CHLORIDES.

The cUorides G"H'''^'C1', are abo rolatile liqaidB heayier tihan water. Heated with
alcoholic potash, they yield chloride of potassium and an aldehyde : e. ff. chloride of
benzylene yields bitter-almond oil. (Wicke, Ann. Ch. Pharm. eii 366) :

C'H«C1« + KHO = Ka + Ha + (THH).

Ammonia heated with chloride of benzylene in sealed tubes, acts in like manner
(Wicke). With alcoholic sulphide of potassium, they are decomposed like the chlo-
rides last mentioned, yielding diatomic sulphides.

y. Of triatomic tdcoholie chUyridea^ only one is known, yiz. chloride of glyeoyl or
trichlorhydrin, (G'H*)"'C1', which is produced by the action of pentachloride of phoe-

HO i

phorus on dichlorhydrin, (G'H*)"'qi2 . (See CHLOBirroBiNS, p. 894.) i

4. cnilorltfea of Aldebyde-Kadleles. — ^These are monatomic dilorides of the '
general form C"H^-'C1, isomeric with the monochlorinated diatomic alcohol-radicles^
e, g. chloride of vinyl, C*H*.C1, with chlorethylene, C*(H"C1). They are obtained by the
action of alcoholic potash on the chlorides of the diatomic alcohol-radides (p. 987X ^om/ei-
times also by that of oxychloride of carbon on the aldehydes, e. g. CH'Cl frcm. acetic
aldehyde, C^^O (Harnitzky, p. 107). It is probable also that they might be ob-
tained by treating the aldehydes with pentachloride of j^oephoms; as butyral, the
isomer of butylic aldehyde, yields when thus treated, the compound (XH'Gl (p. 689).

These chlorides are volatile liquids, except chloride of vinyl, which is gaseous at
ordinary temperatures. Chlorine converts them into dichlorides of chlorinat&l alcohol-
radicles.

5. ClUorlde* of Aeid SadlolMk — These componnds may be derived from aeids
by the substitution of chlorine for peroxide of hydrogen, e.g,\

Chloride of acetyl, CH'O.Cl from Acetic acid, . 0*H»O.HO
Chloride of sulphuryl, (S0«)''.C1« „ Sulphuric add, (SOT(HO)«
. Chloride of phosphoiyl,(PO)"'.Cl» „ Phosphoric add, (BOyjiJlOY

0. Monatomic add dilorides axe mostly derived from oinmic adds ; in faet^ the
only inorganic compounds of this class are hydrochloric octdt, HCl ; chloride ofazctyi^
NO.Cl, produced by the direct combination of chlorine and nitric oxide gases, or by
the decomposition of nitromuriatic add; and chloride ofnitryl, NO'.d, produced by
the action of oxychloride of phosphorus on nitrate of lead : SPbNO" + PC1«0 « Pb'PO*
+ 3N0*C1, or by the action of chlorhydrosnlphuric add upon nitre : KKO* + HCISO*
•e NO'Cl •!- KHSO^ Free chlorine, ClCl, may be regarded as the chloride corre-
sponding to hypochlorous add, C1.H0.

The chlorides of monatomic organic adds are obtained : by the action of the chlo-
rides of phosphorus, or of the oxychloride, on the corresponding acids :

c»H*o.H.o + pa».ci» = c'H»o.a -j- hci + pci».o.

Benxolc acid. Chloride of

beuoyl.

or of trichloride or oxychloride of phosphorus on salts of the same adds :

8(0^HK).K.0) + PC1«0 - K'PO* + 8(C»H»0.a).

Bensoate of Chloride of

pota^lum. beiiioyl.

B<HnetimQB also by the action of chlorine on the corresponding hydrides (aldehydes) :

C^H*O.H + Cl» « C^HK).C1 + HCL

They are mostly fuming volatile liquids (chloride of cyanogen, CK.Cl, is gaseous),
remarkable for the fadlil^ with which they are decomposed by water and its deriva-
tives (aJcohols, alkdis, alkaline salts, &c.), and by ammonia and the compound
ammoniaa.

Water transforms them into hydrochloric add and a monobade organic add:

C«HH).C1 + H^'O - HCl + C«H»O.H.O.

Chloride of Acetic acid,

acetyl.

With alkaHs, in like manner, they yield the alkaline salts of the corresponding aeids^

and with adds, compound ethers :

C«H»0.C1 + C«H».H.O - Ha + C*H«O.C«H».0.

Chloride of Alcohol. Acstate of ethyl.

acetyL

Distilled with the alkaline salts of monobasic adds, they yield anhydrides :

C«H«0.C1 + C«H»O.K.O « KCl + (C*H»0)«0.

Chloride of Acetate of Acetic

acetyl. potassium. anhydride.

C«H«0.a + C'H»O.K.O = KCl + C«H»O.C^O.O.

Chloride of Benzoate of Aceto-beniotc

acetyl. potauium. aohydrlde.

CHLORIDES. 899

With unmonii, or caibonate of ammoniiim, they yield primarj amides :

C'H»0.a + NH» - HCl + N.H«.(rHK).
Chloride of BeniamMd

baoiojL

and with compound ammoniaa they yield alkalamidee :

C»HH).C1 + N.H«.C«H» - HCa + N.H.C«BP».C'HH).
Chloride of Phenjr- Phenjl-bensamlda.

bensojl. Limine.

In like manner, with primary amides they form seoondaiy amides :

CmH>,Ci + N.BP.CHK) - HCl + N.H.C'BPO.C'HH).

Chloride of AceUmide. Aoeto-beoMmlde.

b«iuoyl.

fi. Ditttomie aeid ehloridea, deriyed from a double molecule of hydzoehlorio aoid, and
corresponding to dibasic adds. Sneh are :

Chloride of carbonyl (phosgene) (00)". Ci*

Chloride of snlphtiryl (80»f.Cl«

Chloride of succinyl (C^H^Oy.a*

Two volumes of the yaponr of these chlorides contain 2 atoms of chlorine capable of
conversion into a metamc chloride by the action of a mineral alkaU.

They are obtained by the action of pentachloride of phosphonis on dibasic adds or
anhydrides, the reaction, as shown by Williamson, consisting of two stages, the first
resulting in the formation of a chlorinated add, the second in that of a chloride^ «,ff.-
with sulphuric add:

^^ipl^* + pci«.a« - (soy 1^^ + Ha + poci».

Chlor-hydroo
sulphuric add.

(SO*)" 1 01^ + PC1«.C1« - (soy.ci* + HCl + POCl*

Chloride of
sulphury!.

Chloride of sulphuiyl and chloride of carbonj^l si^ ftlso formed by the direct combi-
nation of chlorine with the radicles, under the influence of light

The diatomic acid chlorides are liquid at ordinary temperatures, with the exception
of phosgene, which is gaseous. Their reactions are similar to those of the monatomic
chlorides.

7. TriatonUo Acid ChhrideSf corresponding to tribasio adds, and containing in
two volumes of vapour, 8 voL chlorine capable of conversion into a metallic chloride
by the action of an alkaU. Such are :

Trichloride of phosphorus PCI*

Chloride of phosphoiyl (ozychloride of phosphorus) . . PO.Cl'

Chloride of sulphophosphoryl PS.CP

Chloride of boron B.C1«

Chloride of cyanogen (soUd) (CN)'.Cl'

The trichlorides of arsenic and antimony must also be regarded as add chlorides. The
explosive compound, commonly called chloride of nitrc^n, is perhaps also a trichlo-
ride, NCI' ; but, according to some authorities, it contains Ir^drogen.

Add trichlorides are produced, for the most part^ by the curect action of chlorine on
the radides. Chloride of phosphoryl is produced by the action of water, and of various
derivatives of water, on the pentachloride, PCI* + oK) - 2Ha + POCl* ; and chloride
of sulphophosphoiyl, in like manner by the action of sulphydric acid on the penta-
chloride. All these compounds are decomposed by water and its derivatives in the
same manner as the mono- and di-atomic dilorides, yielding adds, salts, and compound
ethers. Most of them unite with monatomic metallic chlorides, forming double chlorides.

9. Tetraiomio Aeid Chloride*, containing 4 at. chlorine in 2 vols, of vapour. Some
of the tetratomic metallic chlorides are of add character, vis. SnCl^ and TiCl* ; chloride
of silidum, SiCl\ is also tetratomic. The only orsanic compound of this dass is tetra-
chloride of carbon, CCl^ (p. 765). In these duorides, two of the dilorine-atoms are re-
tained less fordbly than the other two.

c. Pentatomie Aeid Chlorides. — Two only of these compounds are known, vis. PQ*
and SbCl*. They are both volatile, but the antimonic chloride suffers partial decom-
podtion at the same time. To each of these chlorides there is a corresponding tri-
chloride, and their general relations indicate that two of the chlorine-atoms are
retained less fordbly than the other three.

With 1 at of water, they yidd hydrochloric add and an ozychloride, a. y. :

PCl» + H«0 = 2HC1 + PC1«0>
3x2

900 CHLORINDATMITE — CHLORINE.

but an excess of water likewise decomposes the ozychloride, forming hydrochloric acid
ftnd phosphoric or antimonic add. Similar reactions are prodooed by *llriiHi»^ and in the
case of pentachloride of phosphoros, by alcohols, the products being hydrochloric acid»
a chloride of the alcohol-radicle, and either oxychloride of phosphorus or a phosphata
of the radicle, according to the quantities present. Thus with phenylic alcohol :

pa» + c^».H.o - c^».ci + Ha + pcih>,

and PC1«0 + 8(C«H».H.O) « (C^»)»PO* + 8HCL

With adds, or with talte of alkali-metal (acetate of sodium, for example) peDta-
chloride of phosphorus yields oxychloride of phosphorus, hydrochloric add, and m
chloride of uie add nidide (pp. 898, 899), and in some cases, if a salt of the alkali-
metal is present in excess, the corresponding anhydride is formed : thus

C^H»O.Na.O + Pa» - Pa».0 + Naa + C'H»0.C1 ;

Benzoate of Chloride of

sodium. beuxoyl.

and CH»O.Na.O + dPO.a - £i^ + (C'H'OyO.

Brazoateof Chloride of Bensoic

fodlum. bentoyl anhydride.

ratm. A product of the action «f chlorine upon indigo (^. «.)
Wm See Imbin.

Symbol CL AtonUo weight 35*5. DmHty 35'5 (referred to hydrogen
as unity.) Atomic volume 1.

Chlorine is a substance yeir widdy distributed in nature. It exista chiefly in the
form of chloride of sodium, which constitutes rock-salt when depodted in inland beda^
sea-salt when dissolyed in masses of water. The sea also contains chlorides of potas-
sium, caldum, and magnesium. The chlorides of caldum, lead, mercury, and silTer,
respectiyely, form the partial or sole constituents of sereral well-known minerals, and
free hydrochloric add has been met with in the air of Tolcanic neighbourhoods.
Chlorine was discovered by Scheele in 1774. Its elementary nature was first esta-
blished by Davy in 1810.

1. Chlorine is usually prepared by the action of hydrochloric add upon peroxide of
manganese, at a gentle heat:

4HC1 + 3M[n«0« « 2H»0 + 2MnCl + a«.

The liberated chlorine may be washed by transmisdon through a small Quantity of
water, and dried with oil of vitrol in the usual manner. It is best ooUeetea by down-
ward displacement It cannot be collected over mercury, on account of its rapid
action on the metal. It cannot readily be collected over water, on account of solubiUty
therein ; but the difficulty may be obviated by evolving the gas rapidly, or by paasing
the delivery tube to the summit of the receiver, or by keeping the water in the trough
perceptibly warm, or by saturating it with common salt In the above reaction, the
peroxide of manganese may be replaced by add chromate of potassium ; as also, though
with questionable advantage, by several other oxidising agents, such as red or brown
oxide of lead, chlorate of potassium, hypochlorite of calcium, nitric add, &c More*
over, a mixture of common salt and oU of vitrol, which generates hydrochloric add
abundantly, may be, and frequently is, substituted for the ready formed hydrodiloric
add, thus :

2Naa + 2^80* + Mn«0* « Na'SO* + Mn«SO* + 2HK) + a«

This is the method usually adopted on the large scale, to generate chlorine for the
manufacture of bleaching powder, cnlorate of potassium, &c It has the advantage of
oUtninnfing the wholo of the chloriue from tne chlorine-compound used, whereas, in
the decomposition of the peroxide by hydrochloric acid alone, half the chlorine remains
as protochloride of manganese. The sulphuric add, when present in excess, has also
the efifect of drying the chlorine. The materials are mixed in a larse alembic of nearly
spherical form, and constructed dther entirely of lead, surround^ at its lower part
with a cast-iron steam-jacket, or of two hemiroheres joined together in the middle,
the upper being of lead, the lower of iron. In the former case the vessel is heated
by steam, in the latter over a very gentle open fire. (See Un^s Dictionary of Arts^
Mantrfacturee and Mines^ L 666.)

Another method, which may be economically practised in sulphuric add works, con-
sists in heating a mixture of common salt and mtrate of sodium (Chili saltpetre) with
excess of sulphuric add. Hydrochloric and nitric adds are thereby evolved, and bj
their mutual action generate chlorine, peroxide of nitrogen and water :

HCl + HNO* -= CI + N0« + HK).

The mixed vapours are made to pass into condensers containing sulphuric add,
which absorbs the peroxide of nitrogen, forming a peculiar compound, which is after-
wards used in the manufacture of sulphuric add itself (see Svlphusio Acid), while the

CHLORINE. 901

chlorine paiuefl on and may be used for the preparation of chlorates or hjpoNchlorites.
The resiane of add sulphate of sodium, left by the action of the sulphuric acid on the
mixture of nitre and sut, remains liquid, and may be ran off into a fiimace and heated
with an additional quantity of salt, producing hydrochloric acid and neutral sulphate of
sodium, which last mtij be used in the manufacture of soda. {Traiti de CHimie gini'
rale^ par Pelouse et Frimy^ 3™ 6d. i 414.)

2. Chlorine is also liberated by the simple action of a red heat upon certain chlorides,
such as those of palladium, platinum, and gold, thus : PtCl' » Pt + CI'. Pentachloride
of antimony, SbCl*, brides u]p, when gently heated, into trichloride of antimony, SbCl*,
and free chlorine, CI' ; and m like manner, the trichloride of gold, AuCl', breaks up
into protochloride of sold, AuCl, and free chlorine, CI*. Moreoyer, chlorine gas fre-
quently results from the decomposition of its oxidised compounds.

ProperHes, — Chlorine has a yellowish-green colour, whence its name (x^wpof), and
a pungent irritating smell. It is irrespirable unless yery much diluted. It is one of
the heayiest substances that are gaseous at common temperatures, being 35^ times
heayier than hydrogen, and 2^ times heayier than atmospheric air. By a pressure of
four atmospheres, at mean temperature 15'6^ C, it is condensed into a yellow mobile
liquid, haying a spedfie grayity 1*33. It has resisted all attempts at solidification. At
ordinaiy temperatures, water dissolyes about twice its yolume of chlorine, forming a
solution whicn has the colour, smell, and general chemical properties of the gas. At low
temperatures, water dissolves a still apreater proportion of chlorine, and at the tempera-
ture 0^ 0. a definite hydrate of chlorine, CL6H'0, crystallises out. If this hydrate be
cently warmed in a seialed tube, it will, at a temperature of 88° C, decompose into a
&yer of water fioating oyer a layer of liquid chlorine. This liquid chlorine may be
readily distilled off, and condensed by means of a freezing mixture at the other extremity
of the tube, which is usually bent for this purpose at an obtuse angle.

Chlorine possesses yeiy actiye chemical properties, and giyes ori^n to many phe-
nomena of combination, substitution and indirect oxidation. It is moreoyer, non-
inflammabl^ and does not unite directly with oxygen under any drcumstances. At
ordinary temperatures, chlorine combines directly with all the metals^ with many me-
talloids, such as hydrogen and phosphorus, and with ma^ compound bodies^ such as
sulphurous anhydride, SO', ol^nt gas, CH^ hengene, CH*, ana carbonic oxide, CO.
Its union with phosphorus, and with finely diyided arsenic, antimony, tin, or copper,
is attended with the phenomena of combustion. At increaised temperatures, chlorine
combines with many other substances, such as sulphur, selenium, boron, and silicon.
It has not been made to combine directly with carbon. When ordinary combustible
bodies containing carbon and hydrogen, such as paper, wood, wax-taper, &c., are
ignited and immersed in a yessel of chlorine, the combustion continues diiefiy at the
expense of the hydrogen, which forms hydrochloric acid, while the carbon is deposited
as a dense black smoke. Preyious ignition of the hydrocarbonised substance is not
always necessary to induce these phenomena. Paper dip]pi^% oil of turpentine,
C'*H", and plunged in a Tessel of the gas, takes fire spontaneously, yielding abundance
of hydrodiloric acid and carbon.

Cnlorine displaces bromine, iodine, Bndijluorine, from their combinations^ by equiva-
lent substitution. Free iodine strikes a deep blue colour with starch ; and when
starched paper dipped in Jpdide of potassium solution is brought into contact with
chlorine, the iodine is libSated by the chlorine, and the characteristic blue iodide of
starch produced: KI + CI ss KCl •(- L Chlorine also displaces A^^ro^^n by equivalent
substitution, one half of the chlorine taking the place of an equivalent quantity of
hydrogen, while the other half unites with the hydrogen eliminated:

Q*WO' + Cl« - C"H"C10» f Ha

Salidn. Chloro mHcIq.

C«H*0« + a* - CHCl'O* + 3HC1.
Acetic add. Trichloracetic

acid.

Chlorine, by combining with hydrogen or a metal, acts indirectly as an oxidising
agent. Thus, when chlorine-water is exposed to the action of sunlight, we have
CI* + H'O « 2HC1 + 0. Again, when feme hydrate, suspended in solution of hydrate
of potassium, is treated with chlorine, we have produced ferric and hydrochloric acids,
which react with the alkali to form potassium salts :

H«0 + Fe'BPO* + Cl» - H»O.Fe»0«, (i.e. H*Fe»0*) + SHCl

Ferric Ferric,

hydrate. acid.

Chlorine destroys the colour of most organic pigments. This bleaching action is
usually accompanied by oxidation and substitution, thus :

C«H»NO + H»0 t Ci' ^ C»H*C1N0» + 8Ha
ludigo. Chlorisatiiu

8h 3

902 CHLORINE.

Chlorine also destioys odotin of yarious kinds, and possibly infections miaamatay
either by abstracting hydrogen with or without substitution, or by indirectly oxidis-
ing. W. O,

Antichloristio Theory. — Chlorine was originally re«irded as a compound bodyv
namely, Oxygenised muriaHc acid^ or OxymrmaHc acta. Muriatic acid waa supposed
to be a compound of oxygen with the unknown radicle MuriaHcwiiy or Mttriumj and
chlorine or oxygenised muriatic acid was supposed to contain the same radicle united
with a larger quantity of oxygen. Moreover, as the driest muriatic acid, when brought
in contact witii red-hot metals, evolves a laige quantity of hydrogen, and as 1 toL
of dry chlorine with 1 vol. of dry hydrogen forms 2 vols, of perfectly diy muriatic
acid gas, it was concluded that 1 vol of chlorine (or oxymuriatic add), contains m
half volume of oxygen, which, in the formation of muriatic acid gas, combines with
1 voL of hydrogen ; and that muriatic acid gas is an intimate compound, in equal
numbers of atoms, of water, and a not yet isolated anhydrous muriatic acid, which
may be called hypothetical anhydrous muriatic acidy to distinguish it from ordinary dry
muriatic acid gas. Bezzelius formerly arranged the various degrees of oxidation in the
series aa follows :

1 at. MvurlinnaBl 1 *4 ^ f

teket op of oxygen thneirUli AntichlorUtic Kamei. Chlorhtlc Kanes.

2 at a 16 ... 27'4 pts. of Hyp. anhyd. muriatic add.

3 „ » 24 ... 85*4 „ Oxymuriatic add. Chlorine.

4 „ a 82 ... 43*4 „ Euchlorine. Hypochloroua an-

hydride.
6 „ — 48 ... 59*4 „ ? Perchloric oxide.

8 „ ■■ 64 ... 75 '4 „ Hyperoxymuriatic add. Ghlorio anhydride

•a^,

10 „ a 80 ... 91*4 „ ? PmMorio anhy-

dride (hyp.)

It is easy to see that most of the phenomena exhibited by chlorine-oomixnmds, may
be rationally expressed in the language of this so-called *' antichloristic theory."
Muriatic acid gas is supposed to be a compound of 1 at. hypothetical anhydrous
muriatic add * 27'4 with 1 at. water » 9, making together 36-4 (MuO>.H:0).* MetaUic
chlorides are hypothetical anhydrous muriates of metallic oxides, MuO'.RO, and may
be formed, with evolution of hydrogen, by contact of a metal with muriatic add gaa, the
oxidation of the metal being produced by the water. The same compounds are formed
when a metal is immersed in oxymuriatic add gas (MuO'), the metal then taking
away the third atom of oxygen of that gas, and forming an oxide, which unites with
the remaining hypothetical anhydrous muriatic add. The formation of a muriate and
hyperoxymunate (chlorate), when oxymuriatic add comes in contact with the aqueous
solution of an alkali, is effected by 5 at of oxymuriatic add giving up their third
atom of oxygen to a sixth atom of the same add, which is thereby converted into
hyperoxymuriatic add [6MuO* + 6K0 « KO.MuO» + 5(KO.MuO«)]. And in all
cases in which chlorine is as an oxidising agent, where the one theoiy supposes that
the element chlorine unites with hydrogen as a metal, and sets oxygen free, the other
supposes that the third atom of oxygen in MuO', performs the same functions.

On the same theory, phosgene gas (oxychlorideof carbon), is supposed to be a com-
pound of hypotiietical anhydrous muriatic add with carbonic add (MuO^.CO*) ; terchlo-
ride of phosphorus is a muriate of phosphorous add, PO'.SMuO', and the pentachloride
is PO'.5MuO*, both compounds being formed by the combustion of phosphorus in the
third atom of oxygen of MuO*, whereby phosphorous or phosphoric add is produced,
which unites with the resulting MuO^

Such was the theory of the chlorine-compounds which maintained its ground till
1809. In that year, however, Gay-Lussac and Th&iard showed, by arguments founded
on numerous experiments, that the chemical rolations of the so-called oxymuriatic
acid, or chlorine, might all be explained on the supposition that it is an elementary
substance, and this view was further carried out by Sir H. Davy in 1810, who first
gave to this substance the name of Chlobink. It is not necessary to go into all the
arguments by which this view was ultimately established ; it is suffident to observe,
that chlorine has never been shown to contain oxygen, or indeed to be capable in any
way of resolution into simpler forms of matter, and thereforo that its daim to the titie
of an element rests on the same foundation as that of the* other bodies at present re-
garded as dementaiy. (For further details, see Chnelin's Handbook, ii 856, and Vir^M
Dictionary of Chemistry^ 4th edition, p. 318.)

• 0«8.

CHLORINE: DETECTION. 903

f QTm 1. Reactions*-^
Chlorine in the £ree state is recognised hy its suffocating odour, its yellow-green colour,
the bleaching action which it exerts on htmus, indigo, and other Tegetable colours, and
the deep blue colour which it produces with a mixture of starch and iodide of potassium.
The aqueous solution exhibits the same characters.

Hydrochloric acid and solutions of metallic chlorides, either neutral or slightly
acidulated with nitric acid, give with nitrate of silver, an immediate white curdy pre-
cipitate of chloride of silver, insoluble in hot nitric acid, easily soluble in ammonia ,*
and with mercurouM nitrate, a white curdy precipitate of mercurous chloride (calomel)
insoluble in nitric acid and in ammonia* and turned black by ammonia^ Both these
reactions are extremely delicate. Solutions of chloride of sodium of various degrees
of dilution, give with nitrate of silver and mercurous nitrate, the reactions indicated
in the following table :

1 pt. chlorine in : Nitrate of Silver. Mercaroui Nitrate.

100,000 pts. water Slight turbidity. Slight precipitate.

200,000 „ ,, Immediate slight doud. Turbidity after a few

minutes.
400,000 „ „ Very slight turbidity. Yeiy slight turbidity

after some minutes.
800,000 M It ^ozy f*^^ opalescence. Opalescence after some

time.
1,600,000 „ „ Scarcely perceptible Scarcely perceptibleopa-

opalescence. lescence after some

time.

' With solution of sal-ammoniac, the silver-solution behaves in a similar manner, and
gives a perceptible doud, even with 3,200,000 pts. of water; with the mercurous solu-
tion, the reaction ceases to be perceptible with 400,000 pts. of water to 1 pt. of chlorine.
(Lassaiene, J. Chim. m^ viii. 618.)

The only salts which give with silver>solution a predpitate resembling the chloride,
are bromides, iodides, and cyanides. Either of these salts is easily detected in
presence of a chloride, viz. bromides and iodides bv the colours of the bromine and
iodine when set free, and by their reaction vrith starch-paste ; cyanides by the
formation of Prussian blue with ferroso-ferric salts ; but the detection of small quan-
tities of chlorine in ptresenee of excess of either of the other salts, presents greater
difficulty. Bromide, iodide, and cyanide of silver are all insoluble in cold nitnc acid,
and more or less soluble in ammonia. Iodine is, however, completely predpitated by
nitrate of palladium, which does not precipitate chlorine : consequently the chlorine
may be detected b^ adding nitrate of silver to the filtrate. The best mode of detect-
ing a small quantity of a chloride in presence of excess of bromide, isto distil the
dried salts with sulphuric add and add chromate of potassium, and pass the evolved
red vapours into ammonia : if chlorine is present, duorocluromic add will be evolved,
and the liquid will be coloured yellow, ftY)m formation of chromate of ammonium ; but
if onlv bromine is present, it will remain colourless. Cyanide of silver dissolves
with decomposition when boiled with strong nitric add, and may thereby be separated
from the chloride, which will remain undissolved.

As the greater number of metallic chlorides are soluble in water, the method of pre-
cipitation by nitrate of silver may be applied to them immediately. Cuprous chlo-
ride, and many oxychlorides which are insoluble in water, dissolve m njtric add,
and the chlorine contained in them may then be detected in the same manner. Oxy-
gen-salts of chlorine, viz. the hypochlorites, chlorites, chlorates, and perchlo-
ra tes, give off their oxygen when heated, and are reduced to chlorides : the reduction,
excepting in the case of perchlorates, may also be effected by sulphurous acid. The
chlorides of phosphorus and other non-metallic dements, are decomposed by
water, yielding hydrochloric add, in which the chlorine may then be detected by nitrate
of silver. The chlorine in organic compounds is for the most part not imme-
diately predpitated by nitrate of silver, only indeed when it may be said to exist as
hydrochloric add, namdv, in combination with organic bases; from other organic
compounds, as the chlorides of the alcohol- radicles, and the numerous class of com-
pounds in which chlorine takes the place of hydrogen, it must first be separated,
either by ignition with lime, or by heating the compound with nitric add in a sealed
tube (pp. 225, 247).

2. Quantitative Estimation, — Chlorine is always estimated as chloride of
silver. If not present as hydrochloric add or a metallic chloride, it must be reduced
to that state by one of the methods just indicated. The solution is then slightly
acidulated with nitric add in tbe cold (the application of heat to the acid solution
would drive off part of the chlorine) ; nitrate of silver is added in excess ; and the

3 M 4

904 CHLORINE : ESTIMATION OF.

liquid either briskly agitated with the precipitate, or else left for some honrs in a
warm place, till the precipitate has completely settled down. The precipitate is col-
lected on a filter, which should be as small as possible, washed with water, and dried
at lOO^C. It must then be separated as completely as possible fi^>m the filter, and
introduced into a porcelain crucible preTiously weighed, the filter burnt to ashes oat-
side the crucible, the ashes added to the contents of the crucible, and the whole stronglj
heated over a lamp till the chloride of silver is brought to a state of tranquil fusion,
after which it is left to cool and weighed. It contains 24*74 per cent chlorine. As a
small portion of the chloride may be reduced by the oieanic matter of the filter during
ignition, it is best, before weighing, to treat the cooled mass with a small quantity of
nitric acid, in order to dissolre the reduced silver, then add hydrochloric add, eva-
porate to diyneas, fuse, and weigh. The quantity of chlorine introduced in this man-
ner, will only be the equivalent of that which may have been lost bv the previoos
reduction. The chloride of silver may also be collected on a weighed filter, and dried
in an oil-bath at about 150° 0.

The quantity of chlorine in a soluble chloride may also be estimated volumetri-
cally, by precipitation with a standard silver-solution, a cubic centimetre of which con-
tains 30*42 milligrammes of silver, corresponding to 10 miHigrammes of chlorine.

Volumetric Estimation of Chlorine in Hypochlorites : Chloiukbtbt. — ^The value of
the so-called " chlorides of lime, potash, and soda," which are mixtures of the hypo-
chlorites, chlorides, and hydrates of the respective metals, depends upon thepercentago
of hypochlorite which they contain, or, what comes to the same things on the quantitj
of chlorine which they evolve when treated with an acid, thus :

2CaC10 + H«SO« - Ca«SO* + B?0 + Cl«

and this quantit;^ mav be conveniently estimated : a, "Bj the quantity of arsenious
anhydride which it will convert into arsenic anhydride in an acid solution : AsH)* +
CI* + 2H«0 « As*0* + 4HC1. — b. By the quantity of ferrous oxide which it wifl
convert into ferric oxide. — c. By the quantity of iodine which it will liberate ttom a
standard solution of iodide of potassium.

a. 14 grammes of pure arsenious anhydride, dried at 100° OL, are dissolved in
caustic potash, and the solution is diluted to 1 litre ; 1 cub. cent of this solution con-
tains 0*014 grm. As'O", and requires for its conversion into atsenie anhydride,
0-010 grm. chlorine (AbH)« - 198 : CI* - 142 : : 14 : 10).

Five grms. chloride of lime are triturated with water, the whole washed into a gra-
duated cylinder and diluted to 100 cc. ; 50 co. of the arsenious solution are placed
in a beaker, diluted with water, saturated with hydrochloric acid, and coloured blue
by a drop of indigo-solution ; and the solution of chloride of lime (well shaken up), is
added firom a burette, till the blue colour is nearly destroyed. A fresh diop of indigo
is now to be added, and then the chlorine-solution again, very cautiously, and drop by
drop, the contents of the beaker being continually asitated, till the colour finally dis-
appears. This marks the end of the operation : for the decoloration of the indigo does
not take place till all the arsenious anhydride is converted into arsenic anhydride.
The percentage of available chlorine in the sample is then easily calculated. Suppose
that 45 cc. of the arsenious solution have been employed ; these correspond to 0*45 grm.
chlorine : consequently, the sample contains 9 per cent of (dilorine in Uie form of
hypochlorite.

Another mode of proceeding is to act on a known volume of a standard alkaline
solution of arsenious anhydride added in excess, and to estimate the excess by a
standard solution of iodine (p. 266). This, according to Mohr, is the only accurate
method.

b. A weighed quantity of the sample is made to act on a known quantity of ferrous
sulphate added in excess, and the quantity of that salt imoxidised by the hypochlorite,
is estimated by a standard solution of permanganate of potassium. jSveiy 1 at. ferrous
oxide converted into ferric oxide, corresponds to 1 at. chlorine :

2Fe»0 + a* :*• H«0 - Fe*0« + 2HCL

c. For the iodometric method, see Analysis, Yoltthbtbio (p. 266. On Ghlobucbtbt,
see also Ur^s Dictionary of Arts^ Manufactures and Mines^ i 671).

3. Separation of Chlorine from other Elements, — The method of precipi-
tation by nitrate of silver serves to separate chlorine from all other elements except
bromine and iodine.

To estimate chlorine in presence of bromine^ the two elements are precipitated to-
other by nitrate of silver, the precipitate dried, ignited, and weighed in tiie manner
Iust described (p. 904), and the bromine determined by the method given at page 678.
?rom this the quantity of bromide of silver in the precipitate is found by the propor-
tion Br : AgBr «■ 80 : 188; this deducted from the total weight of the precupitate,

CHLORINE : ESTIMATION OF. 905

ffiyes the quantity of chloride of nlyer therein; and 24*74 per cent, of this last qoantily
18 the amount of chlorine sought.

The method of estimating chlorine in presence of iodine is preciselj similar.

When chlorine, bromine, and iodine occur together, the iodine is first precipitated
by nitrate of palladium (see loDoai), and in the filtrate the chlorine and bromine are
determined as aboTe. Or the three elements may be separated and estimated by
Field's method (p. 678).

4. Atomic Weight of Chlorine, — The atomio weight of chlorine vas determined
by Berzelius (Ann. Gh. Phys. [2] xcL 102) in connection with those of silTer and
potassium ; and the same method nas been carried out, with yery neariy accordant
results, by Marignao (J. pr. Ghem. zzxi 272 ; Ann. Oh. Pharm. xUt. 14), Penny
(PhiL Trans. 1839, p. 129), Maumen'6 (Ann. Oh. Phys. [3] zriuL 41 ; Ann. Oh. Pharm.
tz. 173), and, lastly, by St as {Beoherchee sur lee Bapporte rSeiproques des Ftrid*
atomiques, BruxeUes, I860). The series of operations is as follows :

1. Ohlorate of potassium, KGIO*, when heated to redness, siyes off all its oxygen,
leaTiog chloride of potassium, whence the atomic weight of cmoride of potassium com-
pared with that of oxygen is known.

2. As 1 at chloride of potassium throws down 1 at. of silrer from its solutions, the
detennination of the quantitjr of chloride of silver precipitated by 1 at chloride of
potassium gires the atomic weight of chloride of silyer, AgOL

Or if a' known weight of ulyer be dissoljed in nitric acid, and the quantity of
chloride of potassium required to precipitate it be determined, the ratio between the
atomic wei^ts of silrer and chloride of potassium becomes known; whence also the
atomic weight of chlorine ma^ be found, by determining the weight of chloride of silrer
produced l^m a given quantity of silver.

8. The quantity of chloride of silver (c) produced fh>m a given weight of silver («)
is found, either by igniting silver in chlorine gas, or by dissolving it in nitric acid and
precipitating bv hydrochloric add : hence, the atomic weight of chloride of silver (to)
being previously Imown, that of silver (x), is fi^und by the proportion, e: e » to : x,
and that of chlorine bv difference ; or, the atomio weight of silver beinff found from
the quantity of chloride of potassium required to precipitate it, that of chlorine is cal-
culated from the composition of the chloride as just determined.

1. JkterTninaiion of the Amount of Oxygen in Ohlorate of Potassium. — This may be
determined either by heating the rait to redness, or else by reducing it with hydro-
chloric add, evaporating to dryness, and i^tinff. In carrying out the former method,
it is necessary to arrange the apparatus in such a manner theit any small partides of
the salt that may be carried away by the escaping gas may be collected ana weighed.

The proportions of oxycen and chloride of potassium in 100 pts. of the chlorate^
and the atomic weight of chloride of potassium thence determineid, by the proportion
O* : EOl » 48 : X, are as foUowa, according to the authorities above quoted :

Benellof. UarlgDM. Peony. HanmenC. Staf.

0* . . . • 89150 89*161 89177 89*209 89154
Ka .... 60-850 60-889 60-823 60*791 60-846

100-000 100000 100000 100000 100-000
Atomic weight of Ea . 74-606 74-575 74-520 74*4*24 74*59

2. Detemdndiion of the Atomic WeigU of Chloride of BSLvef :

100 ptB. of chloride of potassium yielded, by predpitation with nitrate of silver :

Benelloi. Marlgnae. Maiim«D<.
OhlorideofsUver ..... 1924 192-35 19276

100 pts. of silver dissolved in nitric add, require of EOI for predpitation :

Marlgnae. Staa.

69-062 69*108

Now 1 at chloride of potassium predpitates 1 at silver, forming 1 at chloride of
silver ; hence, according to Marignae — -

100 : 192-35 - 74*575 : AgOl - 143*44.

3. By igniting 100 pts. of silver in chlozine gas^ the fiollowing quantities of dibride
of silver are obtained :

Bersdioi. ICarisnae. Panaj. lfanm«ii. Staa.

^ * s

(1M4.) (IMa.)

AgOl . . 132*75 182-78 13284 132-84 132-78 132*845
Comparing now Marignac's first number, 132*73 (which agrees with that of Maumen4

906 CHLORINE : OXIDES AND OXYGEN- ACIDS.

and reiy nearly with that of Benelinfl) witii his determination of the atomic weig;ht
of ehlonde of silver above quoted, viz. 143*44, we find for the atomic weight of fiilver:

132-73 : 143-44 - 100 : Ag = 10806

whence: CI - 143*44 - 108*06 - 36*38

and : K - 74*675 * 36*38 « 3919

If, again, we start from the same atomic weight of KGl as before, viz. 74*675, and
assume, according to Marignac's second determination (also that of Penny) that 100 ptsL
silver produce 132*84 pts. chloride; also that 100 pts. silver require for predpitation
69*062 £C1 (Marignao), we arrive at the numbers in the left hand column of the
fbllowing table ; those in the right are £>und in like manner from the detenninataona
of Stas:

Marignae.
K - 74*575 - 35*46 » 3912

StM.

ICO K 74-69 _
•*« 89.108 i"n«

107-04 X 82-848 _

100
K » 74*59 - 85-45 « 8914

Dumas (Ann. Gh. Phaxm. <**iii 21), by igniting silver in chlorine gas, focmd
that:

9*954 grm. silver gave 13*227 AgCl
19*976 „ „ 26*542 „ .

whence, taking the atomic weight of silver at 108 (a result deduced from the analyses
of the nitrate by Marignac) :

The first determination gives CI - 35*512
The second „ „ CI » 35*499

Mean » 35*5

This number 35*5, being also very near to the results above detailed, is genendly
adopted.

CMMbOMXMM, BTBIULTB OV. CL5HK).— When water is introduced into a
vessel filled with chlorine, in quantity not exceeding 5 at^ water to 1 at. chlorine, and
the vessel is exposed for some days to a freezing temperature, a pale yellow translucent
hydrate is formed, sometimes in arborescent crvstalline masses, sometimes in needles
and rhombic octahedrons. It may be sublimed from one part of the vessel to another.
When gently heated in an open vessel, it is resolved into chlorine gas and aqoeoos
solution of chlorine. At 38^ C. in a sealed tube, it is resolved into aqueous cUorine
and free liquid chlorine, which separates as a distinct stratum. The hydrate acts on
ammonia, ammoniacal salts, and alcohol in the same manner as gaseous chlorine.
(Faraday, Quarterly Journal of Science^ zv. 71.)

OSIKIBXMa, OSXBBSff and OXTOaWi^ACIDS OV* Chlorine forms four
oxygen-acids, all of which may be regarded as oxides of hydrochloric acid, namely:

Hypochlorous acid HCIO Chloric add HC10»

Chlorous acid HCIO* Perchloric add HC10«

They are obtained by the following processes :

1. Hypochlorous add, HCIO, is produced by oxidising hydrochloric add witii per-
manp^anic add ; and hypochlorite of potasdum is formed, together with chloride^ by
passing dilorine into a cold solution of potaah :

KHO + Cl« - KaO + KCL

2. Solution of hypochlorous add, HCIO, especially at increased temperatures, is
converted spontaneously into chloric add, HCIO', together with water, chlorine, and
oxygen. Moreover the solution of an alkaline hypochlorite, when boiled for some
time, breaks up into chlorate and chloride : 3EC10 » ECIO^ + 2E:CL

3. Chloric add, HCIO*, when deoxidated by nitrous add, yields chlorous add,
HCIO' ; and conversely, chlorous add, by its spontaneous decomposition, yields chloric
add and other products.

4. Chloric acid, HCIO', when oxidated at the positive pole of a voltaic battefi^,
vields perchloric add, HCIO*. Moreover chlorate of potassium, when moderately
heated, breaks up into perchlorate of potassium, chloride of potasdum, and oxygen.

Hypochlorites, chlontes, chlorates, and perchlorates of alkali-metal, when strongly
heated, are alike converted into chlorides bv loss of oinrgen.

The anhydride of a monobasic oxyeen-acid is formed from two atoms of the add by
the loss of one atom of water. The cnlorine-acids should therefore yield the following
anhydrides :

CHLORINE: OXIDES AND OXYGEN- ACIDS. 907

Acldi. Anhfdridat.

2HC10 — HH) « CIK) Hypochloroiui
2HC510« - H*0 - any* Chlormis
2HaO« - BPO - a«0» Chloric
2HaO* - BPO - C1«0' Perchloric

The first two anhydrides are tolerably well known, the lafit two hare not jet been
obtained. We are, however, aoqnaintea with the corresponding iodic and periodic
anhydrides, I^' and VC, respectirely. By the reabsoiption of an atom of water,
one atom of each anhydride is xeconTerted into two atoms of the corresponding acid

a«0 + ffO - 2HC10

a*0« + H*0 - 2HC10»
(IW or) C1«0» + HH) - 2HC10* (or 2mO»)
(PO* or) CIH)' + HK> - 2HCaO* (or 2HI0*)

In addition to the abore anhydrides, s eomplete series of chlo^e-ozides should
obrioosly indade three other tennsi thus :

CP Chlorine

CIK) Hypochlorons anhydride

CIK)* Chloric oadde?

CIK)* Chlorons anhydride

CIK>* Perchloric oxide

C1K)« Chloric anhydride

any Hyperchloric oxide ?

Cl'O' Perchloric anhydride

Sonbeiran obtained from eachlorine (p. 913) a gas which deoomposed into equal
Tolumee of chlorine and oxygen, a result considered by Berzelius to be condusiye of
the existence of chloric oxide, ^mrchloric oxide is not improbably identical with
Millon's porchloro-chlorio acid, CrO*% or 8C1H>* (?)^ Perchloric oxide is a yeiy
well-known substance, which, moreover, appears \o be identical with Millon's cfaloro-
chloric add, C1*0**, or 8C1K)^ (P) Perchloric oxide is decomposed by water into
chlorous and chloric adds :

Cl«0« + H»0 - HC10« + Hao».

HypoehlorouB Anhydride Acid^ and Salts,

Htpocklobous Ahhtdbidb. Cro.— This gas, which was discoyered by B alar d
in 1834 (Ann. Ch« Phys. [2] Ivii. 225), may be prepared : 1. By adding ^cial phos-
phoric acid to a concentrated solution of hypochlozous add standing over mercury.
The glacial phosphoric add abstracts water from the hypochlorons add, and the
gaseous anhydride thus produced collects in the upper put of the tube : 2HC10 —
WO - CPO.

2. By passing chlorine gas over mercuric oxide contained in a tube kept cool by
ice:

Hg«0 + a* - QH) + 2Hga

The mercuric oxide should be prepared by predpitation, and dried at a somewhat high
temperature, 800^ C. Any excess of mercuric oxide rcmains combined with the re-
sulting mercuric chloride in the form of a brown crystalline oxychloride. The gas
may be collected by downward displacement, or in the mercurial trough, but it cannot
be kept long over mereuiy, as it gradually acts upon the metal

Hypochlorons anhydride is a gas of a pale reddish-yeUow colour, and a powerful
o^our somewhat resembling that of chlorine. Its specific gravity does not appear to
have been determined experimentally. By calculation, supposing the molecute to oc-
cupy two volumes, it is ^ ■» 43*6, referred to hydrogen, and 8'016 re-
ferred to air as unity. It is so readily decomposed into two volumes of chlorine and
one volume of oxygen, that it cannot be preserved nndianged, even for a few hours.
By a slight elevation of temperature, or sometimes s^ntaneously, decomposition takes
place with explodon. In sunlight the decomposition is very rapid, but usually lianquiL
At the low temperature product by a mixture of salt and ice, the gas is condensed
into a deep orange-coloured liquid, heavier than water, and very explosive. Both the
gaseous and liquid anhydride dissolve in water, undergoing decomposition and being
converted into hypochlorons add :

a*0 + HK) - 2HC10.

The general reactions of the anhydride correspond with those of the add, but are more
violent.

Htpochlobovs Acid. HCIO. — This add may be prepared :

1. From the anhydride, as just mentioned.

2. By passing air saturated with hydrochloric add through a solution of perman-

908 CHLORINE: OXIDES AND OXYGEN- ACIDS.

ganate of potaMiaip, acidiiLited with snlpliaric acid and heated in a water bath. The
oistiDate is a solution of hypochloioiiB acid fonned by the direct oxidation of hydro-
chloric acid: HQ + O - HCIO.

3. By the addition of almost any oxacid to a metallic hypochlorite.

4. By passing chlorine gas into water, holding snspended or dissolred certain me-
tallic oxides, hydrates, carbonates, snlphates, pnosphates, &c. In practice, oxide of
mercniy, and, according to WiQiamson, carbcmate of caldnm, are found to be the most
advantageous. Either of these snbstanoes is to be agitated with water and treated witii
chlorine gas:

Ca«CO« + BPO + a* - C0« + 2HC10 + 2CaCJL

The product of the action is to be distilled off, and if necessaiy concentrate^ by one
or two redistillations of the most volatile distillates.

Aqueous hypochlorous add has a yellowish colour, an acrid taste, and a character-
istic sweet cUoroid smeUL The strong add decomposes n^idly, eyen when kept in
ice. The dilute add is more stable^ but is decomposed by long boiling into chloric
add, water, chlorine, and oxygen. Hypochlorous aad, like chlorine, possesses powerful
bleaching properties. MoreoTer, ehloro-deriTatiTes may be produced by its agency,

tiius:

(yR* + HCIO - C«HK31 + H«0.

Beniene. Chloro-

benicoe.

Hydrochloric add decomposes hypochlorous add, with fennation of chlorine:

HaO + HCl - HK) + Cl«.

Hypochlorous add is a Tory powerful oxidising agent It rapidly oonyerts many of
the elements, iodine, selenium, and arsenic^ for instance, into their highest oxides^ at
the same time liberating chlorine. The metals difSsr much from one another in the
nature of their respective reactions with hjnpochlorous add. Those u^ch deoompoee
the add form oxides, as does iron, or oxychioridee, as do copper and mereuzy. Simr,
indeed, forms a diloride and liberates oxygen, thus :

Agf + 2HaO » 2AgOI + HK> + 0.

Kany metallic oxides, those of manganese, cobalt^ and lead, fiir example, are per-
oxidised, with liberation of chlorine; but oxide of silver is converted into chloride of
silver, with liberation of oxygen :

Ag*0 + 2HaO = 2Aga + H*0 + 0«.

HTFOCELOBms. — 1. Pure hypochlorites are made by neutraHsing hypoddoroas
add with hydrates, sudi, for instance, as those of sodium, potasnum, caldum, barium,
magnesium, zinc, copper, &c. — 2. Hvpochlorites are usually prepared by passing
chlorine gas into solutions of hydrated or carbonated alkali, or over the dry hydrates
of the earths. Bjr this process, a chloride and a hypochlorite are simultaneously pco-
du(»d. The reaction is oelieved to be as follows :

a« + 2CaH0 = CaCl + CaClO + H?0.

These mixed compounds constitute the bleaching and disinfiBcting salts of commerce^
the properties of which were known as earlv as the time of BeraioUet They were
long regarded as chlorides of the alkali- and earth-metals, and known as chloride of
lifMf chloride of eoda^ &c., till Berzelius suggested the idea that they mi^t be mix-
tures of metallic chlorides with alkaline chlorites (SPO.Gl'O*). Balard, in 1834, showed
that their properties are best explained by regarding them as mixtures of chloridee
and hypochlorites. The only objections to thu view are that alcohol does not extract
chloride of oddum from bleaching powder, as we should d priori expect, and, unlike
mixtures containing chloride of caldum, bleaching powder is not deUqueseent. These
anomalies may possibly be due to the formation of a double salt^ containing diloride
and hypochlorite of caTciuTn in diemical combination with one another.

The pure hypochlorites, when acted upon by sulphuric add, or even by carbonic
add, lil^rate hypochlorous add, thus :

2CaC10 + H«SO* = 2HaO + Ca«SO*.

The mixed salts behave in the same manner, provided the sulphuric add is not in
excess ; but otherwise chlorine, and not hypodilorous add, is evolved :

CaClO + Caa + IPSO* « HK) + OT + Ca«SO«.

The sulphuric acid acts first upon the hypochlorite to liberate hypoddorous add, and
then upon the chloride to liberate hydrochloric acid, the co-existence of which two
adds cannot occur, owing to their mutual decomposition into water and free dilorine,

CHLORINE: OXIDES AND OXYGEN-ACIDS. 909

88 we have already seen. Hydrochloric acid can liberate hypochlorooB acid from the
pure or mixed aalte, thiw : NaClO + HCl = HCIO + NaCL jBut any excess of hydro-
chloric acid immediately reacts upon the nascent hypochlorous acid to form water and
chlorine. Solutions of the hypochlorites, either pure or commercial, are rery unstable,
but are more permanent in the presence of free alkali. Th^ gradually giye off oxygen
gas, and final^ yield mixtures of chloride and chlorate. Their decomposition takes
pkce vezy definitely at a boiling temperature, thus :

SCaaO a CaQO' + 2CaCL

Of themselTes they act as bleaching agents, probably by erolution of oxycen ; but the
effects produced oy acidifying their solutions, ana thereby liberating hypochlorous
acid, are much more rapid. With most metallic oxides and salts, the hypochlorites
react as does hypochlorous acid upon the oxides. They conyert oxide of silyer, for
instance, into chloride of silyer, with liberation of oxygen :

Ag'O + 2NaC10 4- H«0 - 2AgCl + 2NaH0 + 0«;

and sulphate of manganese into hydrated peroxide of manganese, with liberation of
chlorine:

Mn«SO* + 2NaaO + HK) - Na«0* + 2MnH0« + a«.

The characters of the indiyidual salts will be described in a distinct article (Htpo-
CHLOsiTBs). For the yaluation of hypochlorites see p. 904.

Chlorous Anhydride^ Aoid, and Salts.

Ghloboxjs Anhtdbidb. GIK)'.— This gas, discovered byHillon (Ann. CIl
Pharm. xlvi. 298), results from the spontaneous decomposition of chlorous acid, which
is a somewhat ill-defined and unstable substance :

2Ha0« = H«0 + a«o«.

It is also produced by the reaction of chloric acid with nitrous acid or anhydride :

2HN0« + 2HC10* = 2HN0« + H*0 + CPOK

Instead of preformed chloric add and nitrous acid or anhydride, a mixture of chlorate
of potassium, nitric acid, and arsenious anhydride is usually employed. The nitric
acid is first reduced by the aisenious anhydride to the state of nittous acid, which is the
real deoxygenant of the liberated chloric acid :

AsH)» + 2H»0 + 2B:C10» - 2Kn»A80* + C1«0«.

The reaction is effected by the. application of a yety gentle heat The aisenious anhy-
dride may be replaced by tartaric acid or other deoxidising agent. The gas must be
collected by displacement.

Chlorous anhydride is a yellowish green gas, pennanent in a freezing mixture of ice
and salt, but liquefiable by extreme cold. Its specific gravity, calculated for a conden-

71 + 48
sation to 2 vols., is — - — *- 59*5 referred to hydrogen, and 4-123 referred to air.

At slijghtly elevated temperatures, 67^ C. and upwards, it is decomposed, with explo*
sion, into chlorine and oxygen. It dissolves freely in water or in solutions of the alka-
line and earUi-alkaHne hydrates, gradually forming chlorous acid or chlorites.

Cki^obgus Aoid. HdO*. — ^This acid may be prepared by condensing chlorous
anhydride in water :

CIK)" + H»0 - 2HC10».

or by acting upon a chlorite witli some diluted add, such as sulphuric or phosphoric :

2Pba0« + H«S0* =■ 2HC10* + Pb«S0«.

The acid, or its concentrated solution, is a greenish yellow liquid of great tinctorial
power, and having strong bleaching and oxidising properties. It does not decompose
carbonates, but reacts slowly with caustic alkalis and earths to form chlorites.

Chlobitbs. MClO'. — The alkaline and earthy chlorites are formed as above de-
scribed. They also result from the action of perchloric oxide on bases (p. 912). They
are, for the most part, soluble, crystallisable^ colourless salts, possessea of bleaching
properties. The insoluble chlorites of silver, lead, and other metals are produced by
double decomposition :

AgNO* + KCIO* - KNO* + Aga0«.

The chlorites are decomposed even by carbonic add.
For the characters of the individufd chlorites, see page 914.

910 CHLORINE : OXIDES AND OXYGEN-ACIDS.

Chloric Acid and Salts,

Ckloric Acid. HCIO*. (Vauquelin, Ann. Ghim. zcr. 91 ; Sernllaa, Amu Ch.
Pliys. [2] xlv. 204, 270.)~1. The acid is liberated from chloiatea by the addition of a
Btronger acid. It is found adyantageona to use eqniyalent qnantitiea of chlamto of
barium and sulphuric acid:

2BaC10« + H«SO* « 2HaO« > Ba'SO*.

The solution of chloric acid is separated from the insoluble sulphate of barium bj fll-
'tration, and concentrated by eyaporation in vacuo. — ^2. This acid also results firom tiia
spontaneous decomposition of solutions of hypochlorous acid, diloxous acid, and per-
oxide of chlorine.

Chloric acid is a colourless syrupyiliquid, having a strong acid reaction, and vrben
warm, a pungent chloroi'd smelL It is decomposed by organic matter, with chairing
and frequently even with ignition. It is somewhat unstable at ordinary temperataresi
At 40^ C. it undeigoes marked decomposition, and at a boiling heat ia rapidlj con-
verted into perchloric acid, water, chlorine, and oxygen. It is a very poweiiiil oxidw-
in^ and bleaching agent It is decomposed by hydrochloric, sulphydric, and salplmioas
acids, with liberation of chlorine.

Ghlosatbs. MGIO*. — 1. These salts may be prepared by saturating the acid with
bases. Chlorate of barium is usually made by this process (p. 885).

2. Zinc, and one or two other metals, dissolve in chloric acid to form chloratfa,
thus : HC^O' + Zn ss ZndO' + H ; but a part of the add always undergoes a mora
complex decomposition.

8. Alkaline chlorates are produced by boiling solutions of the hypochlorites, or, wliat
comes to the same thing, by passing chlorine into caustic or carcMnated alkali, and
boiline the resulting liquid : 3KC10 » KCIO* + 2KC1. The chlorate is separated from
the chloride by crystallisation.

The chlorates are chiefly interesting as sources of oxyeen gas. Chlorate of potassium
and most chlorates are decomposed by heat into chloride and oxygen, thus, KCIO* »
KCl + 0' ; but the chlorates of the earth-metals yield oxygen, chlorine, and metallic
oxide: 2MgC10' » Mg*0 + CI* + 0*. Prior to the ultimate decomposition of chlorate
of potassium, a portion of perchlorate is produced. The fused chlorates are powerful
oxidising agents. Mixtures of chlorate with combustible substances, such as sulphur,
sulphide of antimony, and sugar, explode violently on the application of heat, or by
percussion. Strong sulphuric acid liberates perchloric oxide firom the chloratoi, an^
by its action on mixtures of chlorate with combustible matters, frequently induces
combustion. Nitric acid reacts with chlorate of potassium to form nitrate of potasBinm,
perchlorate of potassium, and free chlorine and oxygen gases. Hydrochloric acid pro-
duces euchlorine, which is a gaseous mixture of chlorine and perchloric oxid& A
mixture of chlorate of potassium and hydrochloric acid is much used for oxidising
mineral and organic compounds. All the chlorates are soluble in water, and hence do
not precipitate the salts of the heavy metals. Chlorate of potassium, the most im-
portant member of the class, is one of the least soluble. Unlue Hie hypochlorites and
the chlorites, the chlorates do not bleach until after the addition of an add. [For the
description of the individual salts, see pp. 885 — 890].

Perchloric Acid and Salts,

Pbbchlobio Acid. HC10^ — This acidwasdiscovered in 1816 byCount8tadion
(Gilb. Ann. lii. 197), afterwards more particularly examined by Serullas (Ann. Ch.
Phys. [2] xlv. 270; xlyi. 294, 323), and quite recently by Rosooe^ who has obtained
it in definite form. It is produced: 1. Bj the electrolysis of chloric acid. Oxygen
and chlorine are evolved in small quantities at the positive pole, and hydrogen at the
negatiye pole ; but the greater part of the oxygen remains in the liquid, and converts
thechlonc into perchloric acia (Stadion).~2. By the distillation of chloric acid
(p. 910). — 3. By the action of sulphuric acid upon chlorate of potassium (see Pbr-
OHLOBio Oxide, p. 912). — 4. By the action of certain acids upon the penhlorates.
Thus, fluosilicic may be added to perchlorate of potassium, and ttie resulting insoluble
fluosilicate of potassium filtered off from the solution of perchloric add; or sulphuric
instead of fluosilicic acid may be employed, and the volatile perchloric acid distiUed
off from the sulphate of potassium. (Serullas.)

Aqueous perchloric acid obtained by either of these methods may be concentrated
by boiling till it attains a temperature of 203<^ C, after which it passes over unchanged
in the form of an oily liquid containing 70*3 per cent, HCIO*. If this oily acid be

* TheM results, which arc not yet publUhfd, have been kindly communicated by Profeisor Roccoe.

CHLORINE : OXmES AND OXYGEN-ACIDS. 91 1

distilled with twice its Tolnme of strong sulphuric add, it gives up its water to the
latter, and perchloric acid passes oyer nearly pure in the form of a yellowish strongly
Aiming liqmd. On continuing the distillation, the oilv acid aboTe-mentioned begins
to pass over ; but as soon as it comes in contact with tne more volatile portion of the
distiUate, the two unite into a ciystaUine mass consisting of a hydrate, HGIO^HK).
Both these products are, however, contaminated with sulphuric acid mechanically
carried over. To obtain the volatile liquid in a pure state, the crystals must be redis-
tilled jper 9e. They then split up into pure perchloric acid, HCIO^ which is obtained
as the first produce of the distillation, and the oily acid, which contains a larger pro-
portion of water, and passes over afterwards. (Boscoe.)

Pure perchloric acid, HdO*, is a colourless very volatile liquid, having a specific
gravity of 1*782 at 15*5 C. Its vapour is likewise colourless and transparent, but on
coming in contact with the air, it absorbs water, and forms dense white ftimes. Per-
chloric acid in this state is one of the most powerful oxidising agents known ; a single
drop brought in contact with charcoal, paper, wood, or other ozganic substance, imme-
diately causes an explosive combustion, which in violence does not fall far short
of the sudden decomposition of chloride of nitrogen. The add unites also very
energetically with water, a violent hissing noise bei^ produced. The greatest care
must be taken in working with this substance, as one drop falling on the skin produces
cauterisation, and leaves a wound which does not heal for months. Like pure nitric
acid, this add cannot be distilled by itself without undeigoing decomposition, a sin-
gular black explosive body bdng produced when it is boiled. It likewise undergoes
spontaneous decomposition at the ordinary temperature, the bulbs in which it was
sealed exploding even when kept in the darL

The composition of pure perchloric add was determined by neutralising it with car-
bonate of potassium, adding acetic add to acid reaction, evaporating to d^ness, throw-
ing the perchlorate of potassium on a weighed filter, washing out the soluble acetate
with absolute alcohol, and determining the composition of the potasdum salt thus pro-
duced. In this manner results agreeing closely with the theory were obtained. Thus,
1*2185 grm. of add gave 1*6786 of potassium salt, calculation requiring 1*6876. Of
this sal^ 0*966 grm. heated with peroxide of iron lost 0*444 grm., and the residual KCl
required 0*744 grm. pure diver for completeprecipitation. Now 0*744 Ag is equiva-
lent to 0-513 KCl, and by calculation 0*966 KCIO* should yield 0*519 KCL (Roscoe.)
The Hydrate, HC10*.H«0 (containing 84-81 per cent. HaO*), is obtained in the
pure state by adding water to the pure add HCIO^ It is a white, solid, crystalline
substance, which mdts at 50^0., and undergoes decompodtion when heated to 110°,
splitting up into the pure add and an aqueous oily adcL Its composition was deter-
mined by the method adopted in the case of the pure add. The specific gravity of
the liquid hydrate at 50° C. is 1*811. Although not so violent in its action on organic
matter as the pure add, the fused hydrate when brought into contact with paper or
wood, induces immediate combustion, and when dropped into water, combines therewith
maldng a hisdng noise.

When it is distilled, the temperature is found to rise gradually to 203° C, at which
point it remains constant, a heavy oily liquid then passing over, which in outward ap-
pearance cannot be distinguished from sulphuric acid. This acid contains 72*1 per
cent, of HCIO*, and does not therefore correspond to any definite hydrate, HC10*.2H*0
requiring 73*6 per cent HCIO*, and HC10*.3H«0, requiring 65*05 per cent. HCIO*.
If aqueous perchloric acid be concentrated by boiling, water goes gS, and the tempera-
ture rises to 200° C, wheU the acid is likewise found to contain 72*1 per cent, of
HC10\ Hence an aqueous acid loses water, and the crystallised hydrate loses per-
chloric acid on boiling under the ordinary atmospheric pressure, until both arrive at a
e>int when no further change takes place, and an add containing 72*1 per cent.
ClO^ passes off unchanged. (Boscoe.)

Aqueous perchloric acid reddens litmus strongly, but does not bleach. ^It dissolves
dnc and iron, with evolution of hydrogen, forming perchlorates. When dilute, it is
unaffected by sulphydric and sulphurous adds, wmch reduce all other oxadds of
chlorine.

Pbb CRL OB ATBS. — ^Thesc salts are produced : 1. By the reaction of perchloric add
with metals, oxides, sulphides, or carbonates, or of perchlorate of barium with sulphates,
thus:

HQO* + BaHO = BaClO* + H«0
2BaC10* + Na«SO« = 2Na010* + Ba«SO«.

2. By the decomposition of chlorates. During the decomposition of chlorate of potas-
sium by heat, and after a considerable evolution of oxygen has taken place, the previously
fbsed salt is observed to assume a pasty condition, and if the heat be then discontinued,
the reddue will be found to consist prindpally of perchlorate and chloride of potasdum.

912 CHLORINE : OXIDES AND OXYGEN-ACIDS.

which two salts may be Beparatod from one another by solution and exystaUisatioo, the
perchlorate being much the less soluble :

2KC10* - KCIO* + KCl + 0«.

Or, the chlorate of potassium may be decomposed by nitric acid :

8KaO» + 2HN0* - KCLO* + 2KN0« + WO + CP + O*,

and the resulting nitrate and perchlorate of potassium separated by dystallisation.

Perchlorate of potassium is sparingly soluble in cola water; butuie perchlorates
in general are soluble, crystalline, deliquescent salts. They deflagrate, though len
-violently than the chlorates, when thrown on ignited charooaL They require a stronger
heat than do the chlorates to effect their decomposition into chloride and oin^gen. Snl-
pharic acid liberates perchloric acid from the perchlorates, but not until the tempera*
ture rises to 100^ C. : other acids liberate perchloric acid, only when they form insoluble
salts with ike bases of the perchlorates. Hence, unlike chlorates, the peichloratee do
not assume a yellow colour when acted upon by sulphuric or hydrochloric add. [For
the description of the indiyidual salt^, see Pbbchlobatbs.]

Perohlorio Oxide and Euohlorine.

Pbrchlo hxc Oxidb. Cl'O^ — This Teiy explosive compound, which was disoorered
by Count Stadion (loc, eit,), may be prepared by the action of strong sulphuric acid
upon chlorate of potassium, whereby perdilorate of potassium, acid sulphate of potaa-
uum, water, and perchloric oxide are produced :

8KaO« + 2H«S0« - KC10« + 2KHS0* + H?0 + aK)«.

The chlorate should be purifled by reciystallisation, fused after drying at the lowest
adequate temperature, and then finely pulverised. The powder must be added little
by Httle to sulphuric acid, made cool by a mixture of ice and salt, until a pasty maas
is produced. This is to be set aside for some time, and afterwards, by means of a water-
bath, to be very gently heated in a retort. The evolved gaseous perchloric oxide must
be collected by downward displacement Calvert has shown that perchloric oxide,
mixed with carbonic acid, may be readily obtained by heating finely powdered ciilorate
of potassium with ciystallised oxalic acid to a temperature of 70^ C. ^p. 888^

I^erchloric oxide is a gas of a bright yellow colour, and sweet aromatic smeU. At tho
low temperature produced by a mixture of salt and ice, it is condensed into a yellowiah
highly explosive liquid. Faraday succeeded in solidifying it by means of the intense
cold produced by Uie evaporation of solid carbonic acid and ether. In dayli^t tiie
gas undergoes spontaneous decomposition into chlorine and oxygen. This decompo-
sition is fi^uently, and, when induced by elevation of temperature, almost invariaHy,
attended by a violent explosion. The contact of highly combustible matters also
determines an explosion. Liquid perchloric oxide unites with water at a tempera-
ture of 0^ C, to form a solid l^ydrate. At ordinary temperatures, water dissolves several
times its volume of the sas* The solution has a yellow colour, is devoid of acid re-
action, bleaches powerfufly, and is very unstable, being decomposed into chloric add,
chlorous add, and other products. Perchloric oxide is absorbed by alkaline solutions
with formation of chlorate and chlorite :

2KH0 + ciK)« <« xao* + Kao» + H*0.

The molecule of perchloric oxide CiH)\ like the molecule of chlorine Gl', seema to be
binary or dyadic, and to halve itself in the act of combination. In this manner, the
correlations of chlorite and chlorate would correspond with those of chloride and hy-
pochlorite, thus :

Chloride ^J Hypochlorite qJo. Chlorite ^,| Chlorate QQt|o.

EnoHLOBiNB. — ^When chlorate of potassium is acted uponby^ hydrochloric add, a
bright yellow gas, called euchlorine, is liberated. This gas contains chlorine and o^-
gen in the same proportions as hypochlorous anhydride, Q'O, but despite its unifoimitj
of composition, it is evidently a mixture, probably of chlorine and perchloric oxide*
The following equation is believed to express its formation correctly :

4KaO« + 12HC1 « 4Ka + 6H«0 + (9C1 + SQO*).

This mixed gas has a sweet aromatic smell, and powerful bleaching properties. By
passing it through a U-tube immersed in a mixture of salt and ice, the perchloric oxide
IS separated in the liquid state fix)m the free uncondensed chlorine. According to
MiUon, the liquid percnloric oxide obtained bv cooling euchlorine, differs from the
liquid perchloric oxide obtained by means of sulphuric add and chlorate of potassium,
in its somewhat greater stability, in its somewhat higher boiling pointy and in the

CHLORINE: SULPHIDES OF — CHLORITE. 9J8

eircninBtanoe that| although, like the nonnal compound, it is decomposed by alkalis
into chlorate and chlorite, yet that, unlike the nonnal compound, it yields two equi-
Talents of the former for one of the latter salt. Hence Millon assigna to it the formula
C1«0" - 3CTO*?

C1«0» + 6KH0 « 3H«0 + 4KaO« + 2KC10*,

but these differences may probably be due to differences in the puritjr of these two
bodies. Moreover, perchloric oxide is a reiy difElcnlt subject to inyestigate, and the
descriptions of different experimentalists yaiy considerably from one another. (See
Gmelin's Handbook, u, 304, 810.) W. 0.

OS&OSnrB, BUIiVBISSS of. Two only of these compounds are known in the
free state, yiz. SCI and SGI'. The former is analogous in composition to hypochlorous
anhydride, CIO, but exhibits no analogy whatever to that compound in its properties.
It is doubtful indeed whether the sulphur or the chlorine in these compounds is the
negative element ; but they are usually regarded as chlorides of sulphur^ and as such
will be more fuUy considered. (See Sulpeub.)

Similar observations apply to the compounds of chlorine and selenium.

CB&0SZ0B070XBB. Dichlonnated Iodide of Methyl CHa^I. (SeruUas,
Ann.Ch. Phys. [2] xxv. 314; xxxix. 225. — Mitscherlich, Fopg. Ann. xi. 164.—
Bouchardat^ Ann. Ch. Pharm. xxii. 2229. — Gm. viL 337). This compound was dis-
covered by Senillas in 1824, but its composition was first ooirectly ascertained by
Bouchardat It is obtained by distilling iodoform with an equal weight of penta-
chloride of phosphorus or mercuric chloride. The materisls are intimately mixed, and
distilled in a retort ; the dark red distillate is decolorised with aqueous potash, then
shaken up with strong sulphuric add, to free it from chloride of ethylene, afterwards
separated from the siSphuric acid by a tap-fiinnel, and purified by rectification.

Chloriodoform is a transparent pale yellow liquid of specific gravity 1*96, having an
aromatic odour and saccharine taste, and becoming rose-coloured by exposure to the
air. It remains fiuid at the lowest temperatures, and is not decomposed by distillation.
It is but sparingly soluble in water. Heated with strong aqueous potash, or with
alcoholic potash, it yields formate, chloride, and iodide of potassium :

CHCra + 2K*0 - CHKO* + 2KC1 + BX

In contact with chlorine gss, it solidifies and yields trichloride of iodine.

CyLOTgAMTO AOIB and CH&OSISAMSDB. See Isamio Acn> and IsA.-

lODB.

OB&ORZ8ATZO ACZD. See Isatio Acm.

OBX4>XZ8ATn>B and CBXiO&ZAATnZC AXSO^ See Isattdb and IsA-
Tio Acid.

See IsATm.
MBUXPHATJUi. See Isatosulfhites.

LeuchtenberffUej Pennine,— ^'XYnM name is applied to certain sili-
cates of magnesia and alumina occurring in plutonic formations, and forming the cha-
racteristic ingredients of chlorite slate. It rormerly included ripidolite and clinochlore,
and is still applied to at least two minerals, differing in crystalline form, and some-
what also in chemical composition. Chlorite from Achmatowsk in the Ural is mono-
clinic ; but the variety called Pennine, from Zermatt in the Yalais, is hexagonal, generally
forming six-sided tables with perpendicular edges, oP . oo P, or with bevelled edges,
oP . P, where P denotes a six-sided pyramid with basal edges of 106^ 60' and pyramidal
edges of 132^ 40' ; also with other faces subordinate. Cleavage perfect^ parallel to the
base. The crjrstaJs are sometimes imbedded singly, but more frequently grouped in
spherical, conical, or vermiform masses ; also in minute scales, forming a deposit on other
minerals. Specific gravity 2'd5 to 2'S5. Hardness 2*0 to 2*5. Flexible in thin lamins,
but not elastic Colour various shades of green, frx)m leek to blackish green. Small
ciystals are dichromatic, appearing red when viewed in a direction perpendicular to
the vertical axis* Lustre nacreous on the basal faces, vitreous to waxy on the
others. Transparent in thin laminie, but generally translucent, and transparent on
the edges only.

AU varieties of clilorite give off water when heated in a tube, and melt with difficulty
before the blowpipe to a black slag, sometimes magnetic. The mineral gives with fluxes
the reactions of iron, more rarely that of chromium, and is perfectly decomposible by
sulphurie add.

The several varieties of chlorite exhibit considerable diversity of composition ; the
essential constituents are silica, alumina, magnesia, and water, the alumina^ however,
being often more or less replaced by ferric oxide and the magnesia by fenons oxide.
The following are analyses: 1. Varrentrapp (Fogg. Ann. xlviii. 186).— -2. Kobell

Vol. L 3 N

ao-M

16-96

88-97

4-87

18-68 a 98-81

13-68

14-97

8811

6-97

0-28

1810 liMol. l-QXafi»n

tl-47

16-67

88 66

«.

bin

0-01

18*48 « 99-11

88-1

18-5

867

0-6

191 a 10-0

80-01

19-11

88*16

4-81

18-tt a 99-60

80-8T

19-llb

83-18

4-49

—

18-64 « 100-89

80-80

17-S7

87-07

1-87

12*80 « 96-88

88*86

18-00

88-29

4-87

19-50 a 99-61

88-07

9-69

88-84

1186

18-58 »90<0B

88-86

18-14

8481

els

19-80 Ofl(P 0^0 s 99-74

914 CHLORITES.

(J. pr. ChfJXL ZTL 470). — 8. Brnel (Fogg. Ann. 3dyi]L)>-4. Deleeae (Ann. CHl Fh j^
[3] IX. 896). — 6, 6. marignao (Urid. z. 430). — 7, 8. Hermann (J. pr. Ghem. zi
13). — 9. Schweiser (Fogg. Ann. L 526). — 10, 11. Harignac (loe. eit.)

SiO* AHO* lCg>0 Fe40> FeSQ Mii*0 H*0

I. Achiiialowfk
9. ScbwarMnttein .
8. ZUlerthal .
4. pTraD6M .
6. Ala (Ptedmont) .

6. Slatoiut (Ural) .

7. .. wkiie .

8. LmektembergOe .

9. ZermmiPetmHu) 88-07
10. n n 88-86

II. Blnnan „ 88-96 18*46 88*71 619 » — 19-69 » 0^ s too

These nnmben may be approzimately repreoented bj the foninila 2(8MK)JSiO') 4-
A1^0*.SiO* 4- 4aq. which, if M denotes magneanm, reqnizes 80*82 SiO', 17*14 MHy,
40*03 MflK), and 12-01 water. If alumina be represented as a protoxide (bj eabstita-
tion of <ub-| A1), the preceding foimnhi maybe reduced to the form M'O.M^SiO* + }s<9-
Besides the above localities, cUorite is found on the Col de Pertdis, in theVooges, and
in various parts of the Eastern United States. (Dana, ii. 294; BammeUber^s
Mineralchemie, p. 534 ; Handw. d. Ghem. 2^ Aufl. iL [2] 1106.)

Ckloritb Eabth is earthy chlorite in the older sense of the word, without regard
to the distinction between cmorite and ripidolite, because in the earthy state the two
minerals can scarcely be distinguished.

Chlobitb Fbbbuoxkoxjs. Ddeante, — ^This mineral occurs in the amygdaloidal por-
phyry of Oberstein and Zwickau. It is massive, with short fibrous or scaly feadieiy
texture. Specific gravity 2*89. Hardness 2*5. Colour olive-green to bladosh-green.
According to Del esse (Ann. Min. [4] xvi. 520) it contains 29*45 percent SiO', 18-25
Al'O', 8-17 Fe«0*, 1512 Fe*0, 1582 MgH), 0*45 CaK), and 12*57 water (» 99-S3),
which may be approximately represented by the general fonnula 2(2HK>Ji*0'.2SLO^
•f 5aq. Chrengesite, from Orengesberg in Dalecarlia, containing, according to Hisinger,
27-01 SiO*, 14-31 AlK)*, 218 Mn«0*, 25*63 FeH), 1481 If^, snd 12-58 water, ap-
pears to be related to it (Dana, ii. 296; SammMferfs Mmeralehemie^ 540.)

Chlobith Sultb. — This name is applied to chlorite occurring in mountain masspH,
including, however, those which are made up in Hke manner of ripidoUte.

Chlobttb-Sfab. See ChlobitoXdb.

cni&OXZTaB. MClO*. (Millon, Ann. Ch. Fys. [3] vii. 298 ; Ann. Ch. Phaxm.
xlvi. 281.) — Salts of chlorous acid. Their general properties are described, togetiier
with those of the add, at page 910. Onfy a few of them have been studied indi-
vidually.

CHI.OBITB OF Babium. BftClO^ — Obtained by saturating chlorous add with
baryta. By quickly evaporating the solution and finishing the evaporation in vnteo, it
may be obtained ciystaUised and free from chlorite. It dusolves readily in water, and
decomposes at 235^ C.

Chlobitb of Lbad, FbdO^ is prepared by adding nitrate of lead to diloioitB
add nearly neutralised with lime or baiyta, washing the sulphur-yellow scaly predpitate
therebv produced, and drying it If the solution be warmed before adding the nitrate
of leacC the chlorite of lead is deposited in larger crystalline scales. The salt deeom*
poses with a kind of explosion at 126^ C. (Hillo n), at 100° (Schiel, Ann. Ch. Pharm.
cix. 317). It sets fire to fiowers of sulphur when triturated therewith fM illo n) ; when
rather large quantities of the salt are mixed with sulphur or a sulphiae of an electro-
negative metal, the mixture takes fire spontaneously after some time (Schiel). Chlo-
rite of lead introduced into sulphydnc add gas blackens at first, but afterwards
turns white, from formation of sulphate of lead. With a mixture of equal parts of
strong sulphuric add and water, it evolves pure chlorous anhydride (CIK)*), especiallj
between 40° and 50° C. and yields 88-75 per cent of sulphate of lead. (Millon.)

The mother-liquor filtered fr^m the precipitate of chlorite of lead in the aboT&-
described mode of preparation, deposits on the sides of the vessels, small sparingly so-
luble yellowish crystals, which appear to be a compound of chlorite and chloride of lead.
(SchieL)

Chlobitb of Potassium. KaO«.— Potash-ley, mixed with excess of chlorous
add, forms a deep red liquid, which, when concentrated, gives off chlorous anhydride,
and leaves neutr^ chlorite of potasdum in the form of a very deliquescent salt 14 o^
the contrary, chlorous add be gradually added to an excess of hydrate of potasdum, the
formation of the neutral salt takes a longer time, and even after the liquid has become
colourless, the presence of free chlorous add may be detected by its power of convert-
ing nitrate of lead into the peroxide. The saline solution must be quickly evaporated.

CHLORITOIDE — CHLOROCAFFEINE. 915

otberwiae the chlorite of potaadam will be completely reflolred into chloride and
chlorate. The same decomposition takes place if it be heated to 160^ G. (Millon.)

Chlobits of Siltbb. AgClO'.— Prepared by mixing a soluble chlorite containing
a slight excess of base with nitrate of suver, and boiling the resulting precipitate of
chlorite and oxide of silyer with water. The solution on coolinp^ deposits the salt in
yellow crystalline scales. At 105^ C. it decomposes with enplosion. A mixture of it
with sulphur takes fire when triturated with a glass rod. In preparing the salt, an
excess of chlorous acid must be avoided, as it would thereby be quickly resolyed into
chlorate and chloride. (Millon.)

Chlobitb ofSodzuil KaClO*. — Deliquescent. Besembles the potassium-salt,
but is not decomposed by a heat bebw 260^ C. (Mill o a)

Chlobitb of Stbontiux. SrClO^ — Ddiquesoent. Decomposes at 208^ C.
(Millon.)

HMMMBXTOTDMb Chlorite Sjpar, Barytofhyllite^ Mtuonite, — ^A coarsely foliated
massive silicate of alumina and iron ibund at Kosoibrod in the Ural, Bregratten in the
1yTo\ and Ghmmmch-dagh in Asia Minor. Its specific gravity is 3*557 ; hardness 5'6
to 6 ; colour dark grey or greenish black ; lustre faint and pearly. Gives off water
when heated in a tube, is infusible before the blowpipe^ but becomes darker and miCg-
netic. It dissolves completely in sulphuric add.

Allied to chloritoide are : MOMnite^ from Rhode Island, which fiises with difficulty
to a dark green enamel, and SismondinCf a dark ^yieh or blackish green mineral of
specific gravity 3 '565 and hardness 5'5. Nearly infiisible before the blowpipe, occur-
ing in the chlorite slate of St MarceL

Analysis: ChhritouU, — 1. 0. Erdmann (J. pr. Chem. vi 86^. — 2. Bonsdorff

iBers. Jahresber. xviii. 283). — 3. Hermann (J. pr. Chem. liii. 18). — 4. Smith
Ann. Min. [4] xviii 300).— 5. Kobell (J. pr. Chem. Iviii. 40. Magonite, Whitney,
(Proc Boston Soc Nat. Hist* 1849, p. 100). Sisnumdine, Delesse (Ann. Ch. Phys.
[3] ix. 385).

CkhHMde *®'

1. KoMibrod • M'SO

8. „ . 27'48

8. „ . i4M
4. Gummueh-dag h 28*76

ft. Bregratten 96*19

Matonite . . »V

Among these analyses Nos. 8 and 5 of chloritoide are the only ones in which the de-
gree of oxidation of the iron appears to have been correctly determined ; these agree
approximately with the formula (2M*O.SiO*).(M*0'J3iO*) + 2aq., which, by substitut-
ing proto- for sesqui-equivalent metals, may be reduced to M'0.2(M^SiO\aq). (Eam-
fndwer^s MifieralcheTtUe, p. 864; Dana, ii. 298.)

cgnK>»0»MWX il lillTPa, Syn. with Chlobidb ofBbnsotl. (See Bbnzotl,
Chlobzdb of, p. 566.)

See Bbnzaiodb {p. 540).

See Bbnzbmb (p. 543).

I Syn. with Tbiohlobobbnzenb. (See Bbnzbrb, p. 543).

C«*H"C10«. (C ah ours, Ann. Ch. Phys. [Sjxxiii. 350.)
— Formed by the action of pentachloride of phorohorus on benzilic acid : the product
is distilled, and the portion which comes over above 250^ C. washed, dried, and rec-
tified. It is a colourless, strongly-smelling oil, heavier than water ; boils at about 270°.
By exposure to moist air, or hj the action of hot strong pota^ it is quickly decom-
posed into chloride and benzilate. With ammonia and phenylamine, it yields crystal-
line products. F« T. C.
cnObOXOBSnolO A€9XB« See Bsmoic Acid.

OB&OBOBawSOlk Syn. with Cblobidb of BbnstlbiiB. (See Bbmztlehb,
Chlobidb of, p. 577.)

CM&OXOBSarZOVXTBX&B. See BsinsoKiTBiLB (p. 563).

OB&OSOliXVZOVXXMZBai See Bbkzoio Ethbbs under Bbnzoio Aoid (p«
554).

CB&OXOSnxOT&f CRXiOXZBS OV» See Bbnzotl, Chlobidb of (p< 6^),

OH&OSOOAmsn. C*H*C1N*0*.— A product obtained by the incomplete
action of chlorine on caffeine suspended in water (p. 708). When purified by three
or ^ur crystallisations from water, it forms a light bulky mass. From alcohol it cirs-
tallises in needles. By tho continued action (3 chlorine, it is resolved into chloride

3n 2

A1«0S

re«o»

F<^0

Ma^O

;m«io

Lime and
alkali

BSO

46*90

98-89

— a 99*99

85ft7

97*06

0-80

499

6'9& a 101*64

80^78

17-8

17*80

—.

878

6-38 at 99*97

89*84

97*69

0*«S

0-58

6*85 a 100*10

88-80

6 00

91*11

8*30

5*50 a 100*40

89*16

88*79

.1.

8-18

.VOOa 99"i8

48*9

—

98-8

— .

—

7*6 a 987

916 CIILOROC AMPHENE — CHLOROCODEINE.

of cyanogen, methylamine, and amalic add. (Rochleder, Wien Aluid. Ber. 1856,
iL96.)

CB&OSOOAMySBira. See Caxphemb (p. 724).

OB&OSOOASBO-RVOSlJXiiFSintZC ACZD. Sjn. with Tbichlobo-

HUTU VL8X7LPHUBOU8 ACID. (866 MbTBTL.)

OB&INBOOAXBOWIO ACZD* Sjn. with Oztchlobidb of Casboit, Cblobidb
OF Cabbobtl, or Fbosgbnb (p. 774).

CMMMROOAMBOMJO BVUMJR8. Gompounds prodaced by the action of chlo-
ride of carbonyl on the alcohols. They may be regarded as compounds of carbonic
. anhydride with the chlorides of the alcohol-radideSi or as bodies formed on the mixed
type HH0.HC1, in which 2 at of hydrogen are replaced by carbonyl, CO, and the
third by an aloohQl-radide, B :

CO'JBCl - CO'^Cl

')C1
B,\0

Their formation is represented by the equation :

co-JS . Ijo - Ha . oo-ja

Cblobocabbonatb of Mbthtx.. 0*0*010' « CW^ vO* (1^^™<^b *>^

P^Iigot, Ann. Oh. Fhys. lyiiL 62.) — Obtained by introducing wood-spirit into a laz^
flask filled with phosgene-gas :

CH».H.O + COa« « HCl + C«H»C10«.

Colourless, yeiy fluid oil, heayier and more yolatile than water ; has a penetratizig
odour ; bums with a green flame. G^eous ammonia conyerts it into carbamate of
methyl (urethylane) :

C0«.CH»01 + NBP - ^]p^^^^lo + HCL

CBLOBO0ABBON1.TB OF Etbtl. C'H^CIO'. (Dumas andP^ligott Ann. Ch.
Phys. Ky. 226.— Cloez, ibid. [3] xyii. 303.— Cahours, ibid, [3] xix. 346.)--Preparwi
like the precediog ; also by the mutual action of alcohol and perchloroformic ether, or
perchlormated o^uilate of methyl:

CH31«0« + 2C*H«0 - C»H»C10* + 0*H»C1H>« + 2HC1.

Ferchloro- Alcohol. Chlorocar- Trichlorace-

formate of bonate of tate of

ethyl. ethyl. ethyl.

CH31«0« + 4C«HK) = 20«HH310* + C«H>H)« + 4HCL

Perchlor« AloohoL Cblorocar- Oxalate of

oxalate of bonate of ethyL

methyl. ethyL

Colourless liquid, yeiy mobile, haying a suffocating odour which irritates the eyes
Perfectly neutral to test-paper. Specific grayity 1'139 at 15® C. Vapour-densitr
3*823. Boils at 94® 0. Very inflammable. Burns with a green flame. Decomposed
by hot water, not by cold. Ammonia conyerts it rapidly into chloride of ammonium
and carbamate of euiyL

Ohlobooabbomatb of Ahyl, C'H"C10', appears to be formed by the action
of phosgene gas on amylic alcohol, but is immediately decomposed by moisture and
conyerted into carbonate of amyl.

See Cbbotio Acm (p. 887).
See CmBAKXC Acm.

OBbOXOCZmrOSa. HtDBIDB of TBTBACHLOBOOnmAMTL. (See CcfKAlCTL.)

ca&O&OOBKOazc ACSD. 01*0" (?) A compound obtained, according to
Millon, (Ann. Ch. Phys. [3] yii. 298) by passing euchlorine (p. 913) through a series
of U-tubes cooled by freezing mixtures, the first to 0® C, the others to — 18®. Hydro-
chloric add then condenses in the first, and chlorochloric acid in the rest, while free
chlorine escapes at the end. Chlorochloric add thus obtained, is a yellowish-red liquid,
which boils at 32® C, and is conyerted into a yellow gas, which decomposes with ex.-
plosion at 70®. With caustic potash, it yields a mixture of 2 at. chlorate and 1 at.
chlorite of potassium, whence its compositioB is inferred :

01*0" + 3K«0 « 4KC10* + 2B:C10«w

Chlorochloric add resembles perchloric oxide, ClO^ in most of its i>roperties, and ap-
proaches yeiy nearly to it in composition (6C10' » Cra") ; indeed it is most probably
nothing but perchloric oxide mixed with excess of chlorine (see p. 913.)

See CoDEQiB.

CHLOROCOMENIC ACID— CHLOROFORM. 917

CHIiO&OCOlKBVZC AOZB. See Comsnio Acid.

See CuMBMs.
See Cuumoi^
OBXiOmOOT.

See CrANAicDa.

Syn. with CHLORAinsio Aom. (See Ainsio

Acid.)

OB]«OSO]>XAOOVT&. When chlorme ia passed into oil of tarragon, a yiscid
oily liqaid is found, called chloride ofdraconyl, containing 39*9 -ger cent C and 3*6 H,
answering approximately to the formnla C**H*^C1K).C1' ; and this, when treated with
alcoholic potash, yielcLi another viscid oU, chlorodraconyl, containing 42*5 C and 3*4 H ;
possibly diloride of draoonyl minus the elements of water. (Lanrent^ Key. scient.
X. 6. — Gerh. iii. 356.)

oniMRtBWAMTaxa JLOtD* See (Enamthio Acid.

OB&OSOFOAM. DichlorinaUd chloride of methyl, PercMorideofformvl, OHCl*.
Sonbeiran, Ann. Ch. Phys. [21 zlYiii. 131. — Sonbeiran and Mialh^ Ann. Ch.
Pharm. hud. 226.— Liebig, ibid, L 198; Dumas, Ann. Ch. Phys. [2] iTi. 116^—
Begnault, ibid, IxxL 677. — Gm. Tii. 342.) — Chloroform was discovered in 1831 by
Soubeiran, who called it Ether bichlorique, and independently in 1832 by liebig, who
regaled it as a chloride of carbon: its true constitution was discoTeied by Dumas in
1834. Hutman (J. Chim. m^d. [3] ir. 476) states, on the authority of Porta's Magia
naturalis and Scott's Letters on Defnumology and Witcherqft, that it was known in
former times, and useA as a means of producing insensibility.

Formation and Preparation. — 1. Chloroform is produced, together with mono-
chlorinated chloride of methyl, CHK}1^ when a mixture of chlorine and gaseous chlo-
ride of methyl is exposed to the sun's rays. If the two gases be made to pass
continuously mto a vessel exposed to the sun and connected with a series of cooled
receivers, the chloroform, being the least volatile of the products formed, condenses
first) and if the current of chlorine be made rather strong, and the receivers not much
cooled, the product consista almost wholly of chloroform.

2. By the action of alkalis on chloral :

C^C1*0 + KHO - CHOT + CHKO*.

Chloral. Chloro- Formate of

form. poCaitiam.

Chloral is distilled with excess of aaueoua potash, soda or bazyta* or with milk of
lime, and the oily distillato is repeatedly agitated with water, separated from the water
as completely as possible by decantation, and distilled with 6 or 8 times its volume of
strong sulphuric acid in a perfectly dry apparatus. (Liebig.)

3. By the action of nascent hydrogen upon tetrachloride of carbon. (Geuther,
p. 766.)

4. By boiling trichloracetic add with aqueous alkalis :

C«HC1K)* + KH) « CHa* + K«CO«.

6. By the action of hypochlorites, or of chlorine, in presence of alkalis on various
organic substances, vi2. : a. On meUiyUc, ethylic, and amylic alcohols, perhaps also on
all alcohols of the series C"H*"'*'*0. Yfith common alcohol and hypochlorite of calcium
the principal reaction appears to be :

C»H«0 + 6CaC10 - CHa« + CaHX)« + 2Caa + CaHO + IPO ;

but other products are likewise formed, and chlorine is set free.— 9. On acetic acid
and acetates ; probably thus :

C«H*0« + SCaClO - CHC1« + Ca«CO« + CaHO + H*0.

c. On acetone.-— <?. On ethylsulphate or ethyltartrato of calcium. — e. On oil of tms
pentine and ite isomers, the oils of lemon, be^mot, copaiba, &c

The most economical method of preparing chloroform, and that which is always
adopted on the manufacturing scale, is the distillation of alcohol with chloride of
lime. The proportions used are about 6 pts. chloride of lime difibsed through 30 pte.
water, and 1 pt alcohol of 83^' Beaum6. The addition of slaked lime is i£o advan-
tageous, as it absorbs the chlorine, which would otherwise be set free^ and thereby
diminishes the quantity of secondaiy products. The following mode of preparation on
the laige scale is given by Kessler (J. Pharm. [3] xiii. 162).

The apparatus consists of a large leaden cylinder, the sides of which are soldered
with lead. Through the middle of the upi>er end passes a vertical rod, provided
at the bottom with fans, and at the top with a curved handle, its lower extremity
turning on a pivot in the base of the cylinder. By this arrangement, the mixture

3n 3

918 CHLOROFORM.

maj be stirred np during the operation, and the heat thereby equally difibaed. In
the npper end of the cylinder there is aJao a wider aperture, which can be closed at
pleasnre, and through which the materiaLs are introduced ; through a third apertoze ii
inserted the deUvery-tabe by which the chloroform yapour is oonTeyed to the eon-
densing apparatus. Opposite to this tube there passes, trough the upper base of the
cylinder, a leaden tube, widened above like a funnel, and reaching just below the
surface of the liquid. Into this funnel-tube, at some distance below the funnel, is in-
serted a steam-pipe, serving to convey steam from a boiler to the inside of the funnel-
tube ; and above the point of insertion of the steam-pipe, the funnel-tube is furnished
with a cock, whidi, when open, allows the steam to pass upwards to the funnel-tabe,
and when shut directs it into the mixture in the cyhnder. This cock serves to regu-
late the supplv of vapour, and thereby regulates the heat The chloroform vapour
passes upwarais through a worm-tube, enclosed in a condensing vessel, to a cooled
woulfe's apparatus, the last bottle but one of which is half filled with alcohol, and the
last with cotton saturated with alcohol. . A dose-shutting wooden cask may be naed
instead of the leaden ^linder. 40 kilogrammes (88*8 lbs.) of the strongest chloride
of lime are introduced into the cylinder by means of a four-cornered wooden funnel
adapts to its widest aperture, and provided, near its lower extremity, with two hori-
sontal rollers pressing against each other, as in a rolling-mill; these, when tamed
by their handles, serre to drive the chloride of lime quickly into the cylinder. 4 kilo-
grammes (8*8 lbs.) of daked lime are next introduced in the same manner, and then a
hectolitre of water (22 gallons^ at a temperature of 80^ to 90^ C, ia poured in. The
apparatus is now thoroughly luted, and the contents are well mixed by turning the
fans. 4 kilogrammes of commercial alcohol are then poured* in, tx>gether wim the
residues of former operations. If the distillation of the chloroform does not imme-
diately begin, steam is admitted from the boiler, and stopped as soon as the di8tiIlati<Hi
is fairly set up. If the evolution of vapour becomes too rapid, cold water is poiured in
througn the funnel-tube. When the reaction is complete, steam is again admitted
into the cylinder, and the contents, which are now heated to 100°, frequently stirred.
After 3 litres (5}^pintB) have been distOled off, the residue contains scarcely any chlofro-
form or alcohoL The contents of the cylinder are discharged by an opening in the bottom,
the liquid portion drawn off, and used in the next operation. The alcohol in the last
two Woulfe*8 bottles likewise serves for the following {reparations, and the process
may be repeated three or four times in a day. 1 kilogramme of chloride of lime yields
from 60 to 80 grammes of pure chloroform.

Aoccnrding to Simerling (Arch. Pharm. [2] liiL 28), Ihe largest quantity of dilotro-
form, in (ffoportion to the alcohol used, is obtained from a mixture of 8 pts. chloride
of lime, 1 pt. quicklime, 1 pt. alcohol, and 40 pts. water; the rectified cUorofbrm thus
produced, amounts to nearly one-third of the alcohol consumed (8 grm. Ghl<»ofiinn
from 26 grm. alcohol).

The use of acetone fi>r the preparation of chloroform is not advantageous, because
the price of it is high, and the product does not exceed one-third of the acetone used.
This proportion was obtained by first distilling 30 grm. acetone with 150 grm. chloride
of lime mixed with water, and rectifying the watery distillate with 40 grm. chloride a£
lime. Chloroform obtained from wood-spirit has an empyreumatie odour, and always
blackens when agitated with sulphuric add. The largest product was 6 grm. diloaro-
fbrm from 60 grm. wood-spirit

For other methods see Ann. Gh. Fharm. xix. 210. — Oman's Handbook, viL 344.

Chloroform may be contaminated with alcohol, ether, and empyreumatie oilsw Ac-
cording to Soubeiran, pure chloroform sinks in a mixture of equal parts of oil of vi^ol
and water. According to Kessler, chloroform, containing alcohol mminishes in volume
on the application of this test. The presence of alcohol causes opalescence when the
chloroform is mixed with water, whereas pure d^roform remains dear (Mialh^
J. Chim. mM.^ [3] iv. 279). ^ Chloroform containing alcohol acquires a green colour
when mixed witii chromic acid or with sulphuric acid and add chromate of potassium ;
pure chloroform produces no green colour (Cottell, J. Phann. [3] xiii. 359). Chlo-
roform prepared from wood-spirit is much less pure tiian that obtained from alcohol.
The former is spedfically lighter than the latter, has a repulsive empyreumatie odour,
and produces unpleasant sensations when inhaled. It is contaminated with about
6 per cent, of an empyreumatie oil, containing chlorine, burning with a smolgr flame,
lighter than water, and boiling between 85^ and 133^ C. This od cannot be completely
separated by simple rectification, but is nearly, but not quite, destroved by distillation
With sulphuric acid. Asimilar oil, but in smaller quantihr, is likewise obtained in the pre-
paration of chloroform from alcohol ; 20 kilogrammes of chloroform from alcohol yielaed,
when rectified over the water-bath, only 40 grm. of residue consisting of this oil ; it is
heavier than water, has an odour different from that of the oil obtained from wood-spirit,
and its boiling point varies from. 68^ to 117^ C. (Soubeiran and Mialh^}. According

CHLOROFORM.

919

to Gregory (Proc Boy. Soc Edinb. 1850, p. 391)i impure chloroform may be nopg-
DiBod by the disagreeable odour which it leaTes, after evaporation, on a doth whidi
has been moistened with it, and by the yellow or brown colour which it imparts to
pnre oil of yitriol when agitated therewith. Pure chloroform placed upon oil of vitriol
piodnces a oontact-snrfi&ce convex downwuds ; impure chloroform gives a phme con-
tact-surface. According to Rous sin (J. Pharm. [3] zxziv. 206), the pnri^ of chlo-
roform may be tested by means of dinitrotulpkide of iron, Fe^'H*S*NH>* (a salt obtained
by the action of ferric chloride or sulphate on a mixture of sulphide of ammonium and
nitrite of potassium^ Pure chloroform shaken up with this salt, remains colourless ;
but if it contains afoohol, ether, or wood-spirit> it acquires a dark colour. To purify
chloroform, Gregory agitates it and leaves it in contact with oil of vitriol till the latter
is no longer coloured by it, then removes the chloroform, and places it in contact with
a small quantity of peroxide of manganese, to free it from sulpnurous acid. According
to Abraham (Pharm. J. Trans, x. 24), chloroform thus pnnfled quickly decomposes,
and is afterwards found to contain hydrochloric add and nee chlorine. According to
Christison (Ml. x. 253), chloroform keeps well after being once treated with oil of
vitriol ; but the continued action of that liquid (especially if contaminated with nitrous
add) exerts a decompodng action upon it

Properties. — Pure chloroform is a transparent and colourless oil of spedflc gravity
1-491 at 17° C. (Regnault); 1*52628 at OP (Pierre). It boils at 61° (Regnault);
at 63*5° with the barometer at 772*52 mm. (Pierre). In contact with platinum-
wire and widi the barometer at 27'' T^, it boils in a diy vessel at 60*8°, but m contact
with water, at 57*3° (Liebig). Its vapour-density is 4*199, according to Dumas;

4*230 according to Regnault. By calculation (2 voL) it is 5 x

0*0693 » 4*141. Chloroform remains liquid and transparent at — 16°C. (Pierre),
but may be solidified by the cold produced by its own evaporation ; when it is thrown
upon a double filter, the rapid evaporation at the edges causes the remaining portion
to solidify in white tufts (Soubeiran and Mialh^). It has a very pleasant, pene-
trating odour, a sweety fi^ taste, and its vapour, when inhaled, produces a sweet taste
on the palate. The inhalation of a small quantity of the vapour causes exdtement
similar to that produced by nitrous oxide ; but a larger quantity produces insensibility
to pain, in fact, a kind of coma : hence it is extensivdy used in surgical operations.*
According to Robin (Compt. rend. xxx. 52) and Augendre (ibid. xxxi. 679), chlo-
roform preserves meat firom putrefaction (200 times its weight, according to Augendre).

Chloroform dissolves slightly in water, imparting its sweet taste to the liquid. It
mixes in all proportions with alcohol, and is partidly predpitated theref^m by water.
It dissolves rapidly in ether. It is quite insoluble in sulphuric add.

It diaaolveBphoiphoruSf ettlphur, todine^ and iodoform, also many organie bases and
their salts. Tne solubilitv of several organic bases in (Moroform has been determined
by Michael Pettenkofer (Jahresber. d. Chem. 1858, p. 863) and A. Schlimpert
(ibid. 1859, p. 405), whose statements however differ widely, as the following table will
show:

QuanHHes of Alkakftds dissolved by 100 pis. of CUoroform,

PettsnkofiBr .

ScbltnperL

Pettenkofer.

Schllnpert

Morphhia .

1-66

V«ratria« .

66-49

116

aoeUto

i*e6

Atroplna .

6I-flB

»'0

Narcoilne .

17-17

Strychnine

to* 16

14-1

Quinine •

»7'47

16-0

nluato

6*6

•ulphate
hydrodilorate .

Caflblne

11*1

Brudne •

M-79

14*0

ClochoDlne .

4-Sl

S*6

DigiUlfaM . . .

.«

i-as

sulphate

3*0

Aconitlne . .

.1.

QiilnldlM(?) .

15-8

Stntonlne .

-•

»*o

DeeomposiHons.^l, Chloroform decomposes when exposed to air and lights with
formation of chlorine, hydrochloric add, and other products ; but when kept under
water, it remains unaltered (M arson, Pharm. J. Tzuis. viii 69).— 2. At a red heat

* ** For the Introduction of thla reliuble remedj we ere indebted to Dr. Simneon ; and altbov^ ether,
hettsoiOi and many other llquidt can produce Inaeniflylllty to pain, chlorofomi u of all the most poverftil
as well at the most manageable. Of coane great care muit be taken to insore it« pvurity, for the ofle
which aocoDinany It are rerr deleterious: and in administering it, one person should do nothing but
watch the poise and respiration of the patient and remove the chloroform If necessary. With due pre-
caution, chlorororm is Tery safe; and this precaution will prerent its being uaed hi cases where its use
Is contra-indicated by the disease of the heart, or by marked tendency to apoplexy." (Gregory, Ham4*
book t{f Organic CkemMrv, Srd ed. London, I85S, p. 178.)

3n 4

920 CHLOROFORM — CHLOROGENIC ACID.

its Taponr appears to be resolved, partly into trichlorida of eaibon and hjdxogen gta,
partly into carbon, hydrochloric acid, and chlorine :

2CHC1* » CKJl* + H*
and: CHCl* = C + HQ + CP

The liberation of chlorine in this manner, is applied to the detection of chlomform
in blood. A quantity of blood, not less than an ounce, is introduced, immediately
after its separation from the organism, into a flask connected by a oork with a kziee»
shaped tube somewhat drawn out in the horizontal arm. A itnp of paper, moistened
with starch-paste and iodide of potassium, is inserted into the end of this tube; the
drawn-out part is heated to redness ; and the flask is heated in a water-bath. The
Tapour of chloroform thereby erolved is decomposed at the red-hot part of the tube,
and the liberated chlorine turns the paper blue. This method is said to be capable of
detecting 1 pi. of chloroform in 1,000,000 pts. of blood (Ragsky, J. pr. Chem. xlri
170). Acocading to Duroy (J. Pharm. [3] xx. 401), it is not to be depended on unless
the blood be taken from the animal immediately after the inhalation of the chloroform,
or immediately after death. Duroy considers it better to pass a stzeam of cold air
through the blood ; then pass the air, together with the chloroform-Taponr, thiou^ a
red-hot tube, and thence into a solution of nitrate of silyer, whereupon, if chlarofarm
be present, a precipitate of chloride of silver will be formed.

3. Chloroform cannot be set on fire in the air, not even with the aid of a wick ; but
its vapour passed into the flame of a spirit-lamp, bums with smoke ; a mixture of
chloroform and alcohol in equal measures, bums with a veiy smoky flame and puneent
odour, producing hydrochloric acid (Soubeiran, Liebig). It imparts a green oolovir
to the flame of a candle ^Liebig). — 4. Chloroform repeatedly distilled in a stream of
diy chlorine, is resolved mto HCl and CCl* (Regnaul t). — 6. Chloroform heated with
nitric acid evolves but a small quantity of nitrous fumes (Soubeiran). — 6. When
kept under sulphuric acid, it gradually gives off vapours of hydrochloric acid. The
alcoholic solution of chloroform, mixed witi& nitrate of silver, does not deposit any ehlo*
ride of silver, even in the course of a month (Soubeiran). — 7. Boiled with potash-Uy
in a closed tube, it is resolved into formate and chloride of potassium ; but the de-
composition is imperfect (Dumas) :

CHa» + 2K«0 - CHKO« + 3Ka

Chloroform is not decomposed by boiling with aqueous alkalis in an open Tessel
(Liebig). Alcoholic potash boiled for a long time with chloroform, produces formats
of potassium (Regnault). A mixture of chloroform, potash, and alcohol, heated in a
sealed tube to 100^ C. for a week, yields ethylene-gas and formic aeid (Berthelot^
Ann. Ch. Fhys. [3] liv. 87). — 8. Chloroform vapour passed over ignUed baryta or
lime, yields metallic chloride, carbonate, and charcoid ; if the heat be moderate, these
products are not accompanied by any gas ; but at a full red heat, carbonic oxide ia
produced by the action of the charcoal on the alkaline carbonate (Liebig, Soubeiran).
— 9. Chloroform may be distilled over potassium without decomposition; but potas-
sium heated in its vapour takes flre with explosion, forming chloride of potassium
mixed with charcoal (Liebig). It is not decomposed by sodtumif even when heated
with it to 200^ C. in a sealed tube (Heints). Chloroform is not decomposed bv
heating with cyanide of potassium, mercury, or silver, even on the addition of alcohol
(Bouchardat.)

A mixture of chloroform and ammonia-gas is decomposed by a heat e^yproaehing to
dull redness, yielding chloride and cyanide of ammonium :

CHa« + 5NH« - 3NH*a + NH*.CN.

If the temperature be raised too high, a brown substance is formed, probably pan-
cyanogen. When a solution of ammonia in absolute alcohol is heated with chloroform
to a temperature between 180° and 190° C, formate of ammonium may be produced
as well as cyanide ; in man^ instances also neither of these salts is formed, but only
a brown mass, probably consisting for the most part of paracyanogen. (H e i n tx, Fogg.
Ann. xcviiL 263.)

Chloroform and phenylamine do not react at ordinary temperatures; but when equal
volumes of the two are heated to 180°— 190° C. in a seated tube, hydrodilorate of
phenylamine is formed, together with hydrochlorate of formyl-diphenyl-diamine.

CHa« + 4(N.H'.C«H*) - 2[(N.H«.C«H»).Ha] + [N«.H.(CH)-(C«H»)«].HCL

(Hofmann, Proc Roy. Soc. ix. 229.)

CKIiOSOrOBMTXi - STFOStnLVHITBIO AOIIK Syn. with Dichlobo-
KBTHTL-suif Hu&ous AoTP. (See Mbthtl.)

CWOMWMQiaano ACIB. Syn. with CAFFBTANinc Acm (p. 709).

CIILOROG£NIN— CHLOROPERCIILORIC ACID. 921

CH&OXOCIinrXir> A substance which accompanies rubian precipitated from
extract of madder by sub-acetate of lead, and forms a green powder when boiled with
sulphuric or hydrochloric acid.

<3B&OSOBnnEiA&a A product of the action of chlorine on hydrate of mTricyl
{a. V.) Its analysis agrees approximately with the empirical foimuU C**H^*^Cr*'*0.
(Srodie, Ann. Ch. Fharm. bud. 144.)

CB&OXOBCaXiAJrB. See Cronstbdtitb.

CB&OSOlOB&AWZ&m* See Melantlinb.

cmOROBKBKCnnULTBSa Compounds of mercuric chloride with basic metallic
chlorides, or with hydrochlorates of organic bases, e. g. ChloromercuraUs of potassium,
KCLHgCl; KCL2HgCl; Ka4H^; Chloromercurais of morphine, C«'H»N0'.HC1.
4HgCl. They are obtained by mixing the aqueous or alcoholic solutions of the com-
ponent salts, and are for the most part crystallisable.

OHXiOBOMBSZTATB OV XSTBTXJUnL C*H'«aH)*.~A crystalline
substance produced by the action of chlorine on methylic alcohol (q, v,)

CB&OXOBnBTBTXkAAB. C*H*Cll — An oily liquid produced by the action of
potash on acetate of trichloromethyl. It has 'the composition of dtchlortthyUntf
(Laurent, Ann. Cb. Phys. Ixiii. 382.) (See Acbtatb of Mbthtl, p. 23.)

CBSbOSOVAVBTBAlTfl. See Naphthalene.

CmOftOVAVBTiauiXZO AOZB. See Nafhthalsnb, CHLOBiMB-DBRiTATnrBS

OF.

CB&OAOmoazc ACXB. This name was ^ven by St Err e (Ann. Cb. Phys.
[3] xxT. 484), to an acid crystallising in microscopic four-sided needles, which he ob-
tained by passing chlorine into a solution of benzoate ofpotassium, containing excess
of potash. St. Eyre assi^ed to this acid the formula C*M*C10'. But from the expe-
riments of Pisani, made in Oerhardt's laboratory, it appears that this acid is nothing
but cUorobenzoic acid, C'HH^IO^ The acid prepared as above was found, after purifica-
tion by repneated crystallisation, to be identical in composition and properties with
chlorobenzoic acid prepared by the action of pentachloriae of phosphorus on salicylic
acid, or on salycilato of methyl. E. Kopp likewise obtained nothing but chlorobenzoic
add, by passing chlorine into a solution of benzoic acid in caustic soda. Hence also,
it may be inferred that St. Evre*s chhronioeamide is identical with chlorobenzamide ;
that chloronicene, a volatile liquid obtained by distilling chleroniceie add with baryta
or lime, is the same as chlorobenzene, CH*C1 ; and that cMoronicine, a base obtained
bv the action of sulphide of ammonium on diloronidne, is identical with chloro-
phenylamine. (Gerh. iii. 980.)

OSAOXOVAZk A hydrated ferric silicate, of which there are two varieties, the
conchoidal and the earthy. The former has a pistachio-green colour, is translucent on
the edges, has a flat conchoidal fracture; specific gravity 2*158 ; hardness 4'6. The
latter has a light green colour, verging towards olive-green and brown, is sometimes com-
pact, sometimes Mable : the compact variety is very soft. The compositioif of Uiis mineral
varies considerably, as the following analyses will show: 1, 2, nom Hungary (Bern-
hardi and Brandos, Schw. J. xxxv. 29) ; 3, 4, from the Meenser Steinberg, near
Qottingen (Hiller, Jahresber. d. Chem. 1857, p. 671) :

SiO«

Fe*0»

Al^O*

HgK)

Mn«0

ffO

1. Conchoidal

18 - 100

2. Earthy .

0-75

—

20 «- 99-75

8, „ •

71-6

16-3

1-5

trace

8*3- 99-8

4. Conchoidal

89-7

280

8-7

2-4

trace

261 « 99-9

It is perhaps a mixture in variable proportions of opal with a hydrated ferric silicate*
Fe«0».3SiO« + 3H«0, or/«*SiO« + H«0, or (/««H«)SiO*, the conchoidal variety analysed
by Hiller, containing about 41 per cent, of the ferric silicate, the earthy variety, 70
per cent. (Jahresber. loe. eit.)

CJKIiO&OP AULAS ATBS. Compounds of dichloride of palladium with the more
basic metallic chlorides, or with hydrocnlorates. They are not much known.

Cm&OXOVAULASITBS. Compounds of protochloride of palladium with the
more basic motallic chlorides, or with hydrochlorates of organic bases ; e,g. chloro-
palladite of potassium, KClPda ; chloropalladito of strychnine, C"H^K)>.HCl.PdCl.

OHXiOSOFAJbMZno ACSD« See Palxitio Acid.

C1*0"? — A compound said to be produced
by exposing chlorous anhydride to sunshine, the containing vessel being at the
same time immersed in water of 20^ C. It is a reddish brown liquid which is de-
composed by heat, but not explosively ; forms extremely dense white ftimes in con-
tact with moist air, and is decomposed by potash; yields 1 at. chlorite and 2 at. dilorato

l-T,- —

922 CHLOROPH^ITE— CHLOROPHYLLITE.

of potaseium : C1*0" + 3KX) =- 2KCaO« + 4KaO* (Millon, Ann. Ch. Ptji. [S]
vii. 298. It u perhaps hyperchloric oxide, C1H>" - 3CPO* (p. 907)-

CB&OSOFB JBZTB* A ferrous silicate, oocmring in foliated or granular manre
forms, in the Faroe Islands, also in the neighbourhood of Fife and of Newcastle, It bs
a dark green colour, and subresinons lostre; roeeific gravify 2*02 ; hardness 1*5 tol
According to Forchhammei's analysis (Berz. Jahresber. xziii. 265), it contains 32*85
per cent silica, 21*56 protoxide of iron, 3*44 magnesia, and 12*15 water, whence tilie
formula 2({Fe'0.{Mg>0).3SiO' + 12H*0, which may be represented as an orthoaiieito
of the form (M*H»)Si»0" + 8H«0.

C^B&OROVHJBnRlTB. A hjdrated ferrous silicate, found in csTities of tb
amygdaloi'dal porphyry of Weissig in Saxony. It is blackisb-green, with dir^ appie-
green streak ; not very hard ; of specific gravity 2*684. Analysis gave 59*4 per cent
SiO', 12*3 F^O, and 5*7 HK), besides alumina, magnesia^ lime, potash, and toAx
(Jenzsch, Chem. Centr. 1856, 76.)

OB&OSOPBAn* A variety of fluorspar, which emits a green light on aUdjOr
tion.

OBXiOSOPBairBBZO ACZB. Syn. with Dichlorophonic acid, (7H*CI 0. (Sea
Fhrnic Acid.)

OB&OBOVHBHZ8ZC AOXD. Syn. with Tbichlobophxnic Acid.

CBlbOBOPBBBUBZC AOZB. Syn. with Pbntachlobofhehxc Acm.

CBZiOBOVBaVTZta This name was applied by Laurent to a crystalline sabstaDM
obtained by the action of boiling nitric acid on trichlorophenic acid. It czystallised
in yellow scales insoluble in water, soluble in alcohol and ether, and subliming in rerf
brilliant scales. Analysis gave 37*8 per cent C, 1*88 H, and 54*30 CL (Gerh. ii. 2&)

CBXiOBOPBOSPBZBB OP BZTmOOHV. See NiTBOOBlf .

CBXiOBOPBT&K. (Berzelius, Ann. Ch. Fhaim. xxi. 257, 262; zxvii. 296.-
Verdeil, Ck>mpt rend, xxiii 689.— Schulze, Ond. xxxiv. 683.— Mulder, Ann. Ch.
Pharm. lii. 421.)— The colouring matter of leaves and the other green parts of plants.
It is extracted bv digesting green leaves for several da^ with etiier, evaporatnig ibe
filtered liquid to oryness, troating the residue with boiling alcohol, and adding to the
solution a small quantity of milk of lime, which precipitates all the colouring natter,
while the alcohol retains a quantity of fat which was mixed with it The ehloiDpbyll
is separated fiN>m the lime by means of hydrochloric acid and ether, which dianlres
the colouring matter, forming a green stratum at the top of the liquid. By evaponting
the ether, the chlorophyll is obtained in the pure state.

Chlorophyll thus prepared is an earthy powder, of a deep green colour, una3te»M«
in the air, infusible, sustaining a heat of 200^ C. without deoompodition, bat deoom-
posing at higher temperatures. It is insoluble in water, even at the boiling heat;
easily soluble in alcohol, less in ether. Adds and alkalis dissolve it with green coloor:
a solution of alum precipitates it Nascent hydrogen decolorises it like ia^
(Mulder). Mulder represents chlorophyll by the formula C^H'NO*, whickhxmftt
cannot be considered as established. According to Yerddl, chlorophyll hss a gnat
analogy to the colouring matter of blood, and like that substance^ contains a W^
quantity of iron. According to Morot (Jahresber. d. Chem. 1859, p. 562), chlorafwyil
is C'"H»N«0», and is always accompanied by a fatty substance, C«H»*0. Thelattff
is produced by the action of atmospheric oxygen on starch, according to the equation;

2C«H"0* + 0« « C^»0 + 4C0* + 3H*0.

and chlorophyll results from the simultaneous action of carbonic add and anunoma oft
this fat, under the infiuence of light :

C«H"0 + 2KH« + loco* « C"H»N*0»,+ 0«.

According to Schultze, chlorophyll forms the colouring matter of several grMO aiu*
malcules inhabiting ponds and ditches, such as polypes, turbellaiias, and inflosona
(Hydra viridis, Vortex viridis, Mesostomum virituUumf J>eroBtomum cmctm, SUffifff
polymorphuSy Ophrydium versatile, Bursaria ifemaUs).

The name ErythrcmhyU has been given to the red colouring matter of Icates la
autumn. It is soluble in water and alcohol ; dissolves with brown cokmr in attain,
and forms with lead-salts, a predpitate of a fine green colour.

_ _ An altered form ofoordierite, found at Haddam in Con-

necticut, ' •- — - ■ . - ., - — ««

form
spedfic

cent S__ , , _- , .^ „ ^ ««,,« „A ^,. vr V vw ^- -'

water ( « 100*66), which numbers, if a small quantity of the iron be supposed to east
as protoxide, may be nearly represented by the formula 2(M«O.M*0".2SiO*) + 3JMlf °'

CIILOROPICRIN — CHLOROSPINEL. 923

2(lCm')SiK)* + 3 aq., which is that of a hydrated oordieiite. {Ramrndther^B Mineral'
ehemtefp. 833.)

OS&omo»ZOSZV. CCl'NO*. (Stenhouse, Phil. Magj;3] zzziiL 63.— Ger-
hard! and CahourSy Compt chim. 1849, pp. 34 and 170.) — This compound may be
regarded as marsb-gaa, CH^ in which 1 at. H is replaced by NO', and 3 more by
cUorine. It is produced : .1. By the distillation of picric add, styphnic add, or chiy-
sammic acid with chloride of ume and water c hence also when the bodies which
yield either of these three adds by treatment with nitric add are first boiled with
nitric acid and then distilled with chloride of lime. To these belong : creosote, salicin,
indigo, cumarin, the yellow resin of Botany Bey, liquid storax, benzoin, Peru-baJsam,
ealbanum, gum assafoetida, ammoniacum, purree, aloes, extract of Campeachy wood,
K)g-wood, Aistic, red sandal>wood, &c. Lastly, Dammara resin, and the chlorinated
rosin formed in the decomposition of usnic add b^ chlorine, likewise yield chloropicrin,
when treated with nitric acid and chloride of lime. — 2. By treatinff picric add with
chlorine water or aqua-regia, or a mixture of chlorate of potassium and hydrochloric add.

To prepare it^ aqueous picric acid is distilled with chloride of lime tall, after about a
quarter of an hour's boiling, no more heayy^ oil pa^sses oyer with the water. Should
tne residue be still yellow, it must be redistilled with firesh chloride of lime. The oil
is separated from the watery distillate, washed with water to which a little carbonato
of magnedum has been added, dried by pladng it oyer chloride of caldum, and
rectified.

Chloropicrin is a transparent^ colourless, strongly refracting oil, of spedfic grayity
1*6667, boiling at 120^ C. Its odour, in the dilute state, is peculiarly aromatic, but in
the concentrated state yeiy sharp, and attacks the nose ana eyes leas persistently, but
quite as yiolently, as yolatile chloride of cyanogen and oil of mustaro. It is neutral
to yegetable colours. It dissolyes sparingly in water, yery easily in alcohol and ether.

Chloropicrin sustains without alteration a heat of 150^ C. ; but when passed through
a red-hot tube, it is completely decomposed, yielding nitric oxide, chlorine, and tri-
chloride of carbon. A small piece of potassium gent^ heated in the oil, causes strong
oxplodon : at ordinary temperatures, it forms in a few days diloride and nitrate of
potasdum. Chloropicrin is not decomposed by aqueous potash, eyen after prolonged
contact ; but alcoholic potash gradually decomposes it, forming diloride and nitrate of
potassium. Aqueous ammonia exerts scarcely any action upon chloropicrin ; but with
Ammoniiical gas or alcoholic ammonia, it forms chloride ana nitrate or ammonium. It
is not acted upon by sulphuric, nitric, or hydrochloric add, eyen at the boiling heat.

Bboxopzobin. CBr^O*. (Stenhouse, PhiLMag. [4]yiiL 36.)~ObUined, like
chloropicrin, by diHtilling picric add with solution of hypoDromite of caldum (lime-
water containing bromine), and purified by washing witn carbonate of sodium, agita-
tion with mercury, and digestion (not distillation) with chloride of calcium. It is a
colourless liquid, heayier than water, haying the acrid odour of chloropicrin. It is in-
soluble in water, easily soluble in alcohol and ether. It may be heated to its boiling
point (aboye 100^ G.) without decompodtion, but is then decomposed, wiUi eyolution
of brown-red yapours, eyen in an atmosphere of carbonic anhydride. At a higher
temperature, it decomposes with slight explosion. The alcoholic solution is slowly
predpitated by nitrate of silyer in the cold, immediately when heated.

CBX4ISOPXATZV ATBS* Compounds of dichloride of platinum with the more
bade metallic chlorides, or with the hydrochlorates of organic bases: e.ff. Chl&roplaii'
nate ofamnumium, NH^CLPta*; ChioroplaHfiate of Strychnine, C**H"I^'.HCLPtCl*.
(See PzATnTux.)

cm&OSOy&ATXVZTas. Compounds of protochloride of platinum with more
basic metallic chlorides: ChloropltUinite of potaesittm, KCLPtCl. (See PLATnruii.)

OSZiOSOBHOllATBS. Compounds of sesquichloride of rhodium with more
basic chlorides, e.g, Chhrorhodate of ammonium^ 2NH*CLBK!P.

See RuBiAx and Maddsb.
See Sauoot.

See SALiosNOf .
Syn. with Htdbidb of CHLOBoaAUOTL. (See Saliotl.)
A grass-green spinel from Slatoust in the Ural, of spedfic
grayitr 3*691 — 3'694. It contains, according to two analyses by H. Bose ^ogg.
Ann. 1. 620) :

A1«0» Fe*0« Mg«0 CuK) Ca«0

64-13 8-70 ' 26-77 0-27 0*27 - 100-24

67*34 . 14-77 27-49 0*62 ~ - 100*22

whence the formuhi Hg*0.(Al*0' ; Fe«0') or Mg(Al ; Fe)K)'. It is distingoiahed bom

Ceybnite (p^ 843) by the absence of ferrous oxide.

924 CIILOROSTRYCHNINE— CHOLESTERIC ACID.

■i See Stbychninb.

See Sttbacin.

CB3bOX08VCOXC ACZB. An acid obtained by the metamorphosis of perchloti-
nated succinate of ethyl. (See Succinic Ethebs.)

CB&OXOBVCCZSZaaBB. See Suocxnimide.

CnOROTBSSBBirS. See Tsbbbbnb.

CHAOBOStnbPBinUO JLCXD^ See Sulfhttbtl, Chloktob of.

CB&OBO VJL&BBZ8ZO ACZB. Syn. with TmcHLOBoyAUisio Acid. (See Va-
leric Acid.)

CB&0B0VAUm08Z0 ACZD. Syn. with TETBACHLOBOTAUEmc Acm.
CB&OBOZA&OVZBZC ACID. See OxAUC Ethbbs.

CB^OBOB AMBTB ABB. Syn. with Pentaghlobinated Oxaxate of Etetl
(See OxAHio Ethebs.)

CB&OBOBBTBZBB. Syn. with Chloboxaloyinic Amhtdbibe. (SeeOxiuo
Ethers.)

CBK0B0ZBTB08B. C^a*0. ^Malagnti, Ann. Ch. Phys. [3] xtI 19.-0b-
tained by the action of monosulphide of potassium on perchloric ether:

c*a»*o + 2K«s » 4K:a + & + c*ci«o.

To prepare it, 60 pts. of monosulphide of potassium are heated with 16 pts. of po^
chloric ether «Lnd 200 pts. of alcohol of 95 per cent Chloride of potassium is thai de-
posited ; the liquid assumes a dark colour ; and after a day, the deposit of chloride of
potassium becomes covered with crystals of sulphur. On adding water to the liquid,
chloroxethose separates in the form of an oil.

It is a colourless, limpid, oily liquid, having an agreeable odour like that of meadow-
sweet, and a saccharine taste. Specific g^vity 1*654 at 20^ C. Boils at 210^ G. vitfa
slight decomposition. Insoluble in water, soluble in alcohol and ether. It is aJtoed
aft^r some time by exposure to the air. It is not attacked by alkalis or by ordiiuiy
nitric acid ; but nitric acid of specific gravity 1*5 attacks it strongly when heated. On
exposing it to sunshine in an atmosphere of chlorine, crystals of perchloric ether nuke
their appearance after a few days : C*C1«0 + 01* = 0*C1>«0. It likewise absorbs bo-
mine in sunshine, producing perchlorobromic ether. Exposed to the action of chlorine
under a layer of water, it yields hydrochloric and trichloracetic acids :

C*a«0 + Cl* + 3H»0 - 4HC1 + 2C«HC1»0«

OB&OBOBTVAPBTBAJUO JLCZB. See Oxtnaphthalic Aod.

CBOCBOCA. A name applied by the natives of South America to dried potatMs
prepared by exposing the peeled and boiled tubers to the alternate action of frost and
sunshine.

CaOBBBFVZTB. Syn. with Obtoutb.

OBOKACBOXn C"H"N*0" « C«H"(NO«yO»(?)— A product of the action of
nitric acid upon bile. This action gives rise to both fixed and volatile products. Tbe
volatile substances formed are capric, caprylic, valeric, and butyric acio, together with
an oily body which, when treated with strong caustic potash, is resolved into^ nitro-
cholic acid and cholacrol, which latter may he separated from the saline solation by
decantation. It is an oily neutral body having a strong odour; dissolves sparingly in
water, freely in alcohol and ether ; when heated, it decomposes with slight ei^losioo.
(Redtenbacher, Ann. Oh. Pharm. Ivii. 145.)

CBOXJL&ZC JLCZB. O^^H^'O'.— Syn. with cholic acid, the non-asotised acid
obtained by the action of alkalis on taurocholic and glyoocholic acids. (See Ceouc
Acid.)

CBOILBZO ACZB* Syn. with Taubochouo Acm, the sulphuretted add of bile.

CBOZiBSTBBZC AOZB. 0*H*»0\— This acid is produced, together vith ebo-
loidanic acid, oxalic acid, several volatile acids, and a resinous substance, by ^^
action of nitric acid on cholesterin. Oholo'idic and glycocholic acids treated with
nitric acid yield the same products. To prepare it> cholesterin is treated ^"'^
nitric acid in a retort, the distilled liquid being frequently poured back, whereby »
resinous mass is produced, which slowly dissolves after prolonged boiling with exceffl
of nitric acid. The liquid, when sufficiently concentrated in the retort, leaves aj *^°
gummy residue, containing a large quantity of cholesteric acid, mixed with choloidanic
acid and a resinous substwice ; and this residue, on cooling, separates into two l^Fra,
the upper of which consists' of crystalline choloidanic acid, while the lower, ^^^^
viscid, consists chiefly of cholesteric acid containing a little oxalic add. On satura^

CHOLESTERIN. 925

ing this liquid with ammonia, precipitating by nitrate of Bilver, and boiling tbe preci-

Sitat« with water, cholesterate of silver is deposited in crystalline crusta, which, when
ecompofled by sol^hxiretted hydrogen, yield the add.

Cholesteric add is a yellowish gummy solid, resembUng the gum of the cherry-tree.
It is deliquescent; veiy soluble in water and alcohol ; has an add, bitter, and astrin-
gent taste, and is decomposed by distillation, giving off bitter vapours and leaving a
considerable quantity of charcoal.

The formulk of the cholesterates is C^'M'O*. The alkaline and earthy salts aro
soluble and uncrystallisable ; the cholesterates of the heavy metals are insoluble.

CBO&XSTnUOr* CH^'O. — ^This substance was first obtained by Conradi, in
1775, from human gall-stones, of which it sometimes constitutes nearly the entire sub-
stance. It has been found in human bile by Chevreul (Ann. Chim. zcv. 6 ; xcvi.
166); in the blood by Lecanu (Ann. Ch. Phys. IxviL 54), Boudet (ibid, lii. 336),
Denis (J. Chim. mM. [2] iv. 161), and by Becouerel and Bodier (Gaz. m6d. No.
zlvii.) ; in the brain (Couerbe, Aiin. Ch. Fhys. IvL 281 ; Fr^my, ibid. [31 ii. 486), in
yolk of egg (Lecanu, J. Pharm. xv. 1; G-obley, ilnd. [3] xu. 12), and in certain
morbid products of the animal economy, such as cerebral concretions, scirrhous matter
of the mesocolon, hydropic liouid of the abdomen, ovaries, testides, &c. (Lassaigne
Ann. Ch. Phys.ix. 324; 0. Henry, J. Chim. m^d. i. 280; Caventou, J. Pharm. xi.
462 ; Lehman n, Lehrb. d. PhysioL Chem. 2** Aufl. L 286). The first exact analysis
of cholesterin was made by Chevreul, who assigned to it the formula above given.
Its metamorphoses have been studied by Marchand (J. nr. Chem. xvi. 37),
Bedtenbacher (Ann. Ch. Pharm. IviL 145), Meissner and Scnwendler (ibid. lix.
107; and J. pr. Chem. xxxix. 247), Zwenger (Ann .Ch. Pharm. Ixvi. 5; Ixix. 347),
Heintz (Pogg. Ann. Ixxix. 524), and Berthelot (Ann. Ch. Phys. [3] Ivi. 51).

Cholesterin is easilv prepared by crystallising biliary calculi firom ooiling alcohol,
to which a little potash is added to dissolve any fatty adds that may be present. The
cholesterin is then deposited in colourless nacreous laminie. To obtain cholesterin from
brain, that substance is treated with ether, the ethereal extract boiled with alcoholic
potash, and the liquid left to cooL It then deposits cholesterin mixed with cerebrate
and phosphate of potassium, from which the cholesterin may be dissolved out by ether.

Cholesterin is white, tasteless, inodorous, insoluble in water, sparingly soluble in
cold alcohol, but dissolves very eiasily in boiling alcohol, from which it separates on
cooling in beautiful crystalline nacreous laminflR, soft to the touch, and melting at
137° U. It dissolves also in ether, wood-spirit, oil of turpentine, soap-water, and
neutral fats. A solution of cholesterin in a mixture of 2 vols, alcohol and 1 voL ether
deposits by spontaneous evaporation laminated transparent ciystals of hydrate of cho-
lesterin, C"H«*0 + HK), which give off their water at 100° C.

Cholesterin resists the action of concentrated alkaline solutions even at the boil-
ing heat; but lime decomposes it at about 250° C, hydrogen being given off and
the cholesterin being converted into an amorphous &tty lK>dy nearly insoluble in
alcohoL

' Cholesterin is attacked by chlorine and bromine^ yielding substitution-products ; the
chlorine compound is C"H"C1H). For the action of nitric acid upon cholesterin, see
Cholesthbic Acid.

Cholesterin sublimes without alteration at 200° C, but decomposes at a higher tempe-
rature, yielding several oilv products and a solid body. When distilled in a retort, it
yields a carbonaceous residue and a neutral oily liquid insoluble in potash, from which
a second distillation with water separates a volatile oil having the agreeable odour of
geraniums.

When ttron^ sulphuric acid i/t gradually added to a slightly heated mixture of cho-
lesterin and dilute sulphuric add, the cholesterin becomes soft, acquires a deep red
colour, and decomposes, giving off all its oxysen in the form of water, and is changed,
without evolution of gas, into three isomeric hydrocarbons, which Zwenger designates
as eholesterilin, a, 5, and c; they are insoluble in water, and may be freed from sul-
phuric add bv washing with that liquid. These hprdrocarbons are easily crystallisable,
and Uke cholesterin are remarkable for possessing hi^h melting pomts. a has an
earthjr aspect, melts at 240° C, and is nearly insoluble in alcohol veir sparingly so-
luble in ether ; b forms shining scales melting at 255°, moderately soluble in hot ether ;
if kept in the Aised state it loses the power of crystallising ; o is resinous without
appearance of crystallisation, and melts at 127°, it is also soluble in hot ether.
• With coneenXx^UA phosphoric acid, cholesterin forms two compounds, called c h o 1 e s -
terone, a and $, isomeric with each other, but differing ia physical properties. Cho-
lesterone a forms very brilliant rectangular prisms, melting at 68° C, and distUling
almost without alteration ; easily soluble in alcohol and ether. The modification fi
forms small silky needles sparingly soluble in ether, neariy insoluble in alcohol.

Tho composition of cholesteruin and cholesterone agrees nearly with the formuli^

926 CHOLESTROPHANE—CHOLIC ACID.

CH^ ; they axe, therefore, either isomeric or poljmeric. Their formation fiom dio-
leeterin is represented by the eqoation :

C*H*H) - HK) - 0«H«

This decomposition shows that cholesterin partakes of the nature of an alcohol; it is,
in fact, homologous with cinnamic alcohol, and its formula may be written C*^^.H.O.
Heated with acetic^ butrrie, benzoic, and stearic adds, it forms compound ethen^ with
elimination of water ; thus with stearic acid :

Stearic Choles- Stearate of

add. terin. cboleateryl.

These ethers are prepared in the same manner as the glycerides, and are purified bj
boiling the product with eight or ten times its Tolume of alcohol, which extracts tie
unalt^ed cholesterin, and arstallising from boiling ether.

Senzoate of ChoUsterjfl, 0»H«K)* » C'H*O.C>«H«*.0, crystallisee in small Bhiniif
micaceous laminsR, which melt between 125^ and 130^ C, dissolve with modcsate
fiicility in ether, very sparingly in boiling alcohol. The butyraie, C^BPO.C"H".0, ii
easQy fusible, somewhat soluble in hot alcohol The stearaU, C>^H"O.(?^<>.0, op-
tallises in small shining needles, haying a neutral reaction, sparin^y soluble in cold
ether, nearly insoluble m alcohol eyen at the boiling heat. The acetate has likeviN
been formed, but is difficult to purify, being more soluble in alcohol than the pieeediDg
compounds. (Berthelot.)

OBO&aiTBOPSAVB. G»H'N*0*.— The name given by Bochleder to the iizul
product of the action of chlorine on caffeine (a. «.), called also nitrotheins by StenhooK,
and regarded by Gerhardt as dimeihylparabanie acid, C\CB.'fSHy. It is also ob-
tained by the action of nitric acid upon csffeine. It is soluble in alcohc^ and ayBtal-
Uses in iridescent scales, which sublime at 100^ C. Boiled with potash it yieiids
carbonate and oxalate of potassium, and gives off ammoniit (according to Bochleder^
or rather methylamine.

OXOXAO AdD. Ckolalie Acid* O^H^^O.—This acid was discovered bj De-
mar9ay in 1888 (Ann. Ch. Phys. [2] Ixyii 177), further examined by Theyer ud
Schlosser (Ann. Ch. Fhaim. xlviii. 77 ; L 236), and finally by Strecker (ibid. Izr.
9 ; Ixvil 1 ; Ixx. 161, 166). It is produced by the action of alkalis on ths acids of
bile, viz. glvcocholie and tauzocholic acids, the decomposition taking place in the mumer
mpresented by the equations :

C^H^NO* + HH) « (?<H«K)» + C*H»NO*
Olycechollc Cholic Glycoclne.

acid. acid.

C«^«NSO» + H«0 - C"H*>0» + C»BraSO»

Taurochloric Cholle Taurinou

acid. acid.

Cholic acid does not exist ready formed in normal bile, but is produced fiom ^
nitrogenised acids of bile during the putrefaction of that liquid after its remoTsi frm
the body. Similar changes appear also to take place within the body in certan
states of disease ; hence, accoromg to Thudichum, it occurs in gall-stones (p. ^8).

The easiest mode of preparing cholic acid is to boil the resinous adds jprecipitated
by ether from an alcoholic solution of bile (p. 586) with baryta- water in a ntort
having its neck directed upwards, adding as much hydrate of barium u will dissolve
in the boiling liquid, and continuing the ebullition for about twelve hours. The 078-
talhne mass of hydrate and chelate of barium obtained on cooling, is decomposed by
hydrochloric acid, the cholic acid then separating as a glutinous resin, while chloride of
barium remains in solution. The cholic acid is suffered to remain in the liquid UU^^
is completely solidifie>d, a few drops of ether being added to accelerate the process, after
which it is washed with cold water, dissolved in boiling alcohol or ethff, and the solo'
tion left to crystallise. Potash may be used in the preparation instead of baiyta, bot
it is less advantageous.

Cholic acid has a bitter taste, with slight saccharine aftertaste. It crystaUiaeB u
two different forms, and with different quantities of crystallisation-water, accordisg tf
it is deposited from alcohol or ether.

a. 2(>H<»0*.6H«0. This hydrate is deposited from boiling alcohol It fonos
tetrahedral or more rarely octahedral cxystfds, belonging to the dimetiia systeao. |

Observed combinations— . ooPandP. oopoo. Ratio of principal to seoondaiy «*^

• Cholic acid is the name originally proposed bv I>emar9ay. Strecker aftervardi altered it to^
lalic acid, resenrlng the term cholic acid for the nitrogenous bile-acid which vieldt this f^^^lSSe
with glycodne, by decomposition 1 but It it more syatematic to call this nitrogenlMd scid f J/c<x*°"^
add, and retain Demar^ay's name for the non-aaotised add.

CHOLIC ACID— CHOLOCHROME. 927

« 0-7946 ; F : Pp in the tenninal edjges « 116^ 114'; in the lateral edges » 96^ 40'.
The crystalfl are colourless, veiy brittle, and have a glassy lustre. In a dry atmo-
sphere th^ lose their water of crystallisation, and become opaque. They dissolye in
760 pts. of boiUng water, in 4000 pts. of cold water, in 20*8 pts. of cold alcohol of
70 per cent, and are yery soluble in boiUns aloohoL The alcoholic solution becomes
tnoiuy on addition of water, and after a whue deposits shining needles. 1 pt. of cho-
lie acid (? the {-hydrate), dissolyes in 27 pts. of ether.

b, C*W*0^*n?0, "This hydrate is deposited from boiling ether, in crystals belong-
ing to the trimetrie system, exhibiting the combination ooP . odI^oo . P, but haying
the aspect of monodinic crystals, in consequence of the predominance of one half of
the P-fikoes in the same sone. Ratio of brachydiagonal, macrodiagonal, and principal
axis - 0*6036 : 1 : 0-3752. Inclination of faces, P : P » 71^ 6S'; 119<> 36', and
144« 39'; P : ooP - 126^ 39'; ooP : ooP - 62<> 16'; »!>«; ooP «. 148° 68'. (H.
Kopp.)

The two hydrates aboye described seem to contain different modifications of cholic
acid ; the dimetric yariety giyes off all its water at 100^ C, and may then be heated
to 170^ without decomposing, whereas the trimetrie modification is not easily dehy-
drated at 100^, and melts, with decomposition, at 160^. The two modifications^ how-
eyer, yield the same salts, and are easily oonyerted one into the other.

GhoUc acid heated to 200^0. giyes off the elemento of 1 at water, and is oonyerted
into choloidic acid: C"H«»0»-H»0 - C»*H"0«, and at 290° it is conyerted in like
manner into djislyrin : C«H«K>»-2H«0 - C^H"0». By distillation, it yields a yel-
lowish, yezy add oil, with only a yery slight carbonaceous residue. The oil is soluble
in etiier and in alkaJis : the aficaline solution procimtetes metallic salts.

Cholic add dissolyes easily in caustic alkalis, also in hot solutions of alkaline car-
bonates, expelling the carbonic add. The Cholatbs, C^H'^0', haye a yery bitter
taste, sometimes slightly saccharine; they are soluble in alcohol; those of tiie earth-
metals and heayy metals are sparingly soluble in water, and may be obtained by
predpitation.

Cholic add and ite salts giye with sulphuric add and sugar the reaction already
described as Pettonkofer's test for bile (p. 686).

Ckolate of Afnfnoniunit obtained by passing ammonii^gas into an alcoholic solur>
tion of cholic add and predpiteting by ether, forms slender needles, soluble in water.
It is decomposed by prolonged exposure to the air, with loss of ammonia, more quickly
when boiled with water.

Chelate of Barium, C^H^'BaO*, is obtained by dissolying the add in baryta-
water, predpitatin^ the excess of bairta by carbonic add, and concentrating the fil-
trate, as a crystalline pellide mammellated on the surface, silky in the interior. It
dissolyes in 30 pts. of cold, 23 pts. boiling water, and in a smaller quantity of alcohol.
The solutions are decomposed by a continued stream of carbonic add. A concentrated
solution of chelate of potasdum yidds a white flaky predpitate with chloride of
barium.

Cholat$ of Calcium^ is predpitated in thick clots, which crystallise from ether.
The copper^alt is a bluish-wmte precipitate. The lead-salt ia white, sparingly so-
luble in water, soluble in alcohol and acetic acid. The manganese-aalt is a semi-
crysta^ne flocculent precipitate. The mercurysalta are white precipitetes, which
dissolye slowly by ebullition.

Chelate of Potaeaiun^ predpitated by ether from its alcoholic solution, or ob-
tained by spontaneous eyaporation, forms slender needles. From its aqueous solution
it is predpiteted by strong potash. Chelate of sodium resembles the potasdum-
salt.

Chelate of Silver is obtained as a white predpitate, which partly dissolyes on
boiling, and crystallises as the solution cools. It blackens slightly at 100^ C, dissolyes
easily in alcohoL

crBO&OOBBOIOL The general name fbr the colouring matters of bile ; it in-
dudes the ordinary brown bile-pigment called cholophsein or biliphsBin ; a green
substance, cholochloin or bitiyerdin, produced by oxidation of cholo|>hffiin ; and
cholofulyin or bilifulyin, a yellow substance found in thickened ox-bile. These
substences were first examined byBerzelius (Lehrb. d. Chem. ix. 281^, afterwards
^ Simon, Plattner, Schmid, Scherer and Heintz (Gerh. Traiti, ly. 632), and
Thudichum {British Medicaljoumal, July 14th, 1860).

Cholophain, or the brown pigment, is contained in bile and in the intestinal canal,
and is the substance to which excrements owe their colour. In certain states of disease
it occurs in the blood, the serous fluids, the urine, and other liquids of the organism,
and is the cause of the yellow colour of the skin and the cornea in jaundice. It is

928 CHOLOCHROME— CHOLOCHROMIC ACID.

most oonTezdently prepared fW>m gall-stones, of which it sometimes forms the chief
part> by eaJiaustimg them with alcohol, ether, and boiling wat«r ; washing the residue
with hydrochloric acid, then with water ; dissolying it in a weak solution of carbonate
of sodium ; and precipitating by an add. Ajb the cholophaein is yeiy apt to naas bto
the green pigment bj oxidation, it is best to perform all these operations u an at-
mosphere of hydrogen (Heintz). From human gall-stones cholopluein may also be
extracted by benzene or by chloroform. (Thudichum.)

Cholophaein recently precipitated is a brown amorphous substance, becoming darker
when diy. It is infusible, insoluble in boiling water ; soluble in boiling alcohol, the
solution gradually tuminff sreen by contact with the air. Hydrochloric acid disaohes
it in sm Jl quantity, aoquirm^ a blue .colour. On adding excess of ammonia, the liquid
immediately acquires a greenish-yellow colour, which is changed to red by nitric add.

Cholophaein contains, according to Heintz's analysis, 60-9 per cent carbon, 6-06
hydrogen, and 9'1 oxygen, whence may be deduced the empirical formula, C^^'^N'O**^
(61-9 C, 58 H, 9-0 N, and 23*2 0).

Caustic alkalis and alkaline carbonates dissolye cholophaein with brownish-yellov
colour : the ammoniacal solution yields a brown flaky precipitate with chloride of
barium or chloride of calcium. A solution of cholophaein in yeiy dilute alcoholic
potash assumes a green colour on addition of hydrochloric acid ; and if nitric add be
then added drop by drop, a fine blue colour is produced, which lasts a long time.

Cholochlo'in or Biliverdin, — This green pigment is produced by the oxidation of
cholophsein. An alkaline solution of the latter gradually oxidises by exposure to the
air, and, if then treated with acids, yields a green precipitate. Cholochlom exists
ready formed in ox-bile, and is abundant in that of biras, fishes, and amphibia.

Thudichum obtains the green pigment by allowing bile to stand m well-dosed
bottles for two years, whereupon a putre&ctiye decomposition ensues (p. 587), and
cholochrome is precipitated, together with cholic acid and other substances. The pre-
cipitate, after decantation of the liquid, is put into a calico-bag and washed with vater
as long as the liquid will pass through ; then boiled with alcohol and washed on a
filter with large quantities of that Uquia, which remoyes cholic acid and its salts, also
fats and fo^tty acids. The colouring matter then remains, mixed with mncos, from
which it may be freed by solution in carbonate of sodium. The alkaline solntioD,
treated with nydrochloric acid, throws down a substance of a fine green colour, vhich
howeyer is probably still somewhat impure.

Cholochlom is aestitute of taste and odour. It does not melt whon heated, bat
decomposes at a high temperature, leaying a laige quantity of carbon. It is inaolahle
in cola, slightly soluble in boiling water ; easily soluble in alkalis, also in alcohol.

According to Heintz, cholochlom contains 60-04 per cent. C, 5-84 H, 8*53 N, and
25-59 0, whence is deduced the empirical formula C"HWO«'*, requiring 60-38 C, 666B,
8-80 N, and 25*16 0. Cholochlom forms with baryta a green amorphous compound,
containing 27*3 per cent baryta.

The formulae of cholophaein and cholochlom, as deduced from their analjses, an
yery uncertain. Thudichum found 60 to 62 per cent, carbon in cholophaein &om gall-
stones, and as much as 66 per cent, in that prepared from bile. Probably both
modifications contain the same number of carbon-atoms, the green compound contain-
ing more oxygen than the brown : thus cholophaein =« CBPNO****, and cholochloih
CH'NO «•« , or possibly C»HWO» and C«H»NO«.

CRBOIiOCBSOMZO AOZ3>. When nitric acid containing nitrous add, is f^ded
to a dilute solution of cholochrome (either brown or green) in an aqueous alkali, th<>
colour of the liquid changes to green, blue, yiolet, red, and finally to yellow. These
changes of colour are connected with the formation of a non-azotised acid, which* ac-
cording to Thudichum, may be obtained by passing nitrous acid yapours into water in
which cholophaein is suspended. Efieryescence then takes place, arising from evolution
of nitrogen; the colour of the bile-pigment changes from brown to red; and on
subsequently shaking it up with ether, a red solution is obtained, which on evaporation
leaves a pink syrupy residue, consisting of the non-azotised add, chohchroiMC add.
It dissolves easily in chloroform, and the solution, when evaporated in an atmosphere
of coal-gas, and afterwards left to stand for some days in a flask filled with the aaine
gas, deposits the acid, partly in fiat rhombic octahedrons, partly in groups of radiating
needles, partly as an amorpnous mass.

Thudichum assims to this acid the formula C^*B^O\ or C«HW^ It should nerhaps
be OIW)*, in whidi case its formation from cholophaein might be represented by the
equation :

C"H»NO« + HNO« = C«H^» + N» + H«0,

the reaction being that of nitrous acid on an amic acid (p. 168).
Cholochromic add is nearly insoluble in cold water, but easily spluble in aloohoi:

CHOLOtoANIC ACID — CHOLONIC ACID. 929

the solution has an add reaction, and precipitates metallic salts. The lead-salt has a
red, the silyer-salt a pink colour.

OBO&omaarzO AOZB. C*<H<<0' (?)— The residue in the retort obtained in
treating choloidie acid with nitric acid, separates on cooling into two layers, the upper
of which is crystalline, and consists of choloidanic acid. The crystalline crust is
drained on a funnel containing pounded glass, and purified by recrystallisation from
boiling water. Should the residue in the retort be merely a resinous mass, it must
be farther subjected to the action of nitric add, which will finally conyert it into the
crystalline add.

Gholo'idanic acid ciystallises in long hair-like prisms, which, after drying on paper,
have the aspect of asbestos. It is nearly insoluble in cold water, and but sparingly .
soluble in boiling water ; easily soluble in alcohol : the solutions are acid. It does
not lose weight at lOO^C; but at a higher temperature it blackens and gives off an
acrid add rapotir. It dissolyes without alteration in hot nitric or hydrochloric add.

Choloidanic aci4 re<}uires a ki^ quantity of alkali to saturate it. The choloidanates
of the alkali and alkalme earth-metals are soluble in water ; the rest are insoluble or
sparingly soluble. They are all decomposed by washing with water.

OMO&OZBZO A03CD. C^H'^O*. — This add was discoyered by Demar9ay, and
has been further examined by Theyer and Schlosser and by Strecker (see refe-
rences, p. 926^. It is produced by the dehydration of cholic add at 200^ C, and,
according to toe observations of Gbrup-Besanez and of Thndichum (p. 687), is one of
the products of the putrefaction of bile : hence also it is found in gall-stones. It may
be prepared directly from bile by boiling that liquid, dissolved in 12 to 15 {)t8. water,
witn excess of hydrochloric add for three or four hours, and leaving the liquid to cooL
Choloidie add then collects at the bottom in a solid mass, which must be several times
melted with water to remove the hydrochloric add, then pulverised, dissolved in a
small quantity of alcohol, shaken up with ether to free it from oholeeterin and nxargaric
add, and finally evaporated to dryness over the water-bath. If the action of the hydro-
chloric add be too lon^r continued, d^slysin is obtained instead of choloidie add
(Demar9ay). Cholo'idic add is likewise obtained by digesting bile with oxalic add.
(Theyer and Schlosser.)

Choloidie acid is a white non-crystalline substance, whieh melts in boiling water
without dissolving to a sensible amount. After drying it requires a heat of more than
160^ C. to melt it It is very soluble in alcohol; water renders the solution milkv,
and separates the acid in the form of a resin ; the solution has an add reaction. It
is sparingly soluble in ether.

Choloidie acid unites with bases and decomposes carbonates with aid of heat The
chloidates of the alkali-metals are soluble in water and alcohol, insoluble in ether ;
they have a pure bitter taste without any sweetish after-taste. By evaporation they
are obtained in the form of ^ummy masses. The salts of the earth-metals and heavy
metals are insoluble or spanngly soluble in water, insoluble in alcohol, and are ob-
tained in the form of plastic predpitates. The hanum^alt, C*H»'BaO<.2H«0 (at
120® C.} is insoluble in water and amorphous. The saver-salt, CP*BVAgQ* (at 100« C.),
is a bulky white predpitate, which undergoes considerable contraction and coloration
by drying.

Cholo'idic acid is oxidised by strong nitric add, yielding a great number of products.
If 1 voL cholo'idic add be treated in a tall vessel with 4 or 5 voL strong nitric add, the
whole distilled to one-fifth, after the first violent action has subsided, cohobating
if necessary, and the liquid, when the action has ceased, diluted with twice its bulk
of water and again distilled, a distillate is obtained having a very acrid suffocating
odour, arising from the presence of a heavy oil, consisting of nitrocholic acid,
CH*N*0* (?), and cholacrol, while on the surface of the wateiy liquid there fioats
a light oil, which is a mixture of acetic, valeric, caprylic^ and capric add. The reddue
in the retort is a yellowish mixture of oxalic, cholesteric, and cholo'idanie adds.
(Redtenbacher, Ann. Ch. Pharm. Ivii. 145.)

CMOIMMIO £LOXn. C>^^>NO^ (Strecker, Ann.Ch.Pharm.lxvii I.— Mulder,
Uniersuch. iiber die Galle, — Gerh. iv. 722.) — This add, which is homologous with
glyco-hyocholic add (C'^H^'KO*), is produced by the action of strong adds upon
glycochoUc acid, frx>m which it diners only by tho dements of 1 at water.

When a solution of gljrcocholic acid in strong sulphuric or hydrochloric add is heated,
it becomes turbid and yields oily drops, which solidify and become rednous on cooling;
and by treating this resinous product with baryta-water, and decomposing the insoluble
barium-sidt with hydrochloric add, cholonic acid is separated, and may be obtained in
shining needles by crystallisation from alcohol.

Cmonate of Sodium, C"H"NaNO», is crysUllisable,
Voi. I. 8 0

930 CHONDEIN — CHONDEODITE.

In preparing cholonic acid by the action of ^hydrochloric on glyeocholic
acid is sometimes formed containing 1 at HK) less. (Strecker.)

OBOWBSnr. C**£P^*0'. (J. Miiller, Pogg. Ann. zxxviiL 305. — F. Simon,
J. Chem. mM. I 108.— Vogel, J. pr. Chem. xxi. 426.— Hopp, ibid, tn. 129).—
A substance resembling gelatin in many of its properties, and long eonfouM^ded With
it : its separate identity was first established by Muller.

Chondnn, like gelatm, does not occor ready formed in the oiganiflm, bat is pgrodaeed
by boiling certain tissues with water. All permanent cartilages in a healthy state yield
cnondrin when boiled with water ; so does bone-cartilage or ossein before cwuuflrjttkni ;
but bone-cartilage aiter ossification yields gelatin by boiling: ao likewi5«e do tiw
tendons, skin, calTCs' feet, hartshorn, isinglass, and fish scales ; idso the pennAiieiit car-
tilages when they become ossified by disease.

Chondrin may be prepared by boiling the cartilages of the rib^ larynx, or jointa
wiUi water for about forty-eight hours, evaporating the liquid to a jelly, and trestiiig
this residue with ether to fipM it from fat The cornea of the eye yields the same
substance.

Chondrin, when dried, is a hard, homy, diaphanous substance, which aoftens to a
jeUy in cold water, and dissolves completely in boiling water ; it is insoluble in aleohoJ
and in ether. The aqueous solution, when boiled for a long time, yields a sabstanes
perfectly soluble in cold water, but resembling chondrin in all its other reactions.

Nearly all acids, oven organic acids, precipitate chondrin from its aqueons solntiaEL
The precipitate formed b^ hydrochloric, sulphuric, nitric, phosphoric, pho^horoiis,
chlonc, or iodic acid, redissolves easily in excess of the acid ; that formed hy sul-
phurous, pyrophosphoric, hydrofiuoric, carbonic, arsenic, acetic, tartaric, oxalirv cHiie,
lactic, or succinic acid does not redissolve in excess of the acid employed. Strong
sulphuric acid dissolves chondrin, forming a syrupy liquid, which, when dilated with
water and boiled, yields leucine without elycocine ^Hopp). Sulphurous acid slowly
decomposes chondrin. Nitric acid, by prolonged action, converts it into xantko-preUk
acid.

Alum, sulphate of aluminium, acetate and subacetate of lead, sulphate of cofpper,
ferrous and ferric sulphates, ferric chloride, mercurous and mereuric nitrates, psoduee
copious precipitates in a solution of chondiin, soluble for the most part in excess of the
reagent Ferrocyanide of pota'^sium produces no precipitata The precipitates formed
by acetic acid, alum, and sulphate of aluminium dissolve completely on addii^ a suffi-
cient quantity of acetate of potassium (or of sodium) or common salt The precipitate
formed by ferric sulphate redissolves on heating the liquid. Mereuric chloride does
not precipitate a solution of chondrin ; sometimes a slight turbidify is produced, owiqg
apparently to the presence of a little gelatin. *

Chondnn is especially distina;uishea from gelatin by its precipitation by alom, snl-
phate of aluminium, acetate of lead, the sulphates of iron and sulphate of copper, and
by its non-precipitation by mercuric chloride. (See Qelltir.)

The aqueous solution of chondrin treated with chlorine, yields a precipitate eontain-
ing C"H*»C1N<0 (?) rSchroder.^

£ly dry distillation chondrin yields the same products as gelatin {q, «.)

Mulder (Ann. Ch. Pharm. xxviii. 328) found in chondrin from human cartilage,
49*3 per cent C, 6*6 H, 14*4 N, and 0*4 sulphur. Schroder also found in chondrin
from the cartilages of the cow, 49*3 carbon and 6*6 hydrogen.

OBOraxOBXTBa Hemiprismatie Chrysolite, Madureite, Sitmite, BmeiU {in
part). — A silicate of magnesium containing fluorine ; sometimes occurring in small
implanted crystals, but more fr^uently in crystalline grains or masses of somewhat
granular structure, imbedded in granular limestone, as at Paigas in Finland, at Aker and
Gul^d in Sweeden, in Sussex County, New Jersey, in Orange County, New York, and
other localities. The variety called humiU is from Vesuvius, where it occurs in ejected
masses of a kind of granite rock, together with olivine, mica, and magnetite.

The crystals belong to the trimetric system, and are often henuhedral in octahedral
planes, producing forms of monodinic cnaracter; ooP : ooP ■> 94^ 26'. They are of
three types, in which the axes have the following ratios :

Macrodiigonal. BrschTdtagonal. Prlndpal axi^

Type L 1*4678 : 1

T^ n 1*5727 : 1

T^Tpein. 1-4154 : 1

1-0806
10805
1*0805

Compound crystals also occur. Cleavage indistinct Specific gravity 8*118 to 3*22.
Hardness 6 to 6*5. Colour yellow or brown, inclining to rad and green, with waxy or
glassy lustre ; more or less translucent. It is scarcely fusible before the blowpipe,
gives the reactions of fluorine when heated with sulphuric acid, and with fluxee the

CHONDROGEN — CHROMATES. 93 1

veactioiifl of iron and silica. DiflsolTes in hydrochloric acid, with Beparation of gelatinous

silica.

Analyses. — 1. Seybert (SiU. Am. J. v. 836. — 2, 3, 4. BammeUberg (Jlftn^ol-
ekemief p. 443). — 5. Fischer (SiU. Am. J. [2] iz. 85. — 6, 7, 8. Bammelsberg (Joe,
dL):

BIOS.

Mi«0.

FeSQ.

Fe^O*.

1. N«w Jersey •

. diarm

MDO

a-38

— MP 4*09; IPO 1*0; K^O S-U

8. ParfUtfetfMV

• tt-oe

6ft-46

8*66

••

7-60 B 99-77

. as- 10

06*61

S-86

8 69 a 100-75

4> »• fV •

. a8-i9

64-50

6-75

m.m

9-69 a 104*18

&. New Jeney, rsd .

. S8-S5

58*05

6-60

-m.

7*60 a 99-60

6. HmmHet type I. .

. M*80

60-08

8-40

cJb.

8-47 - 10075

7. M type II. .

. S8M

67-99

070

5-04 AHOS — 1*06 » 100-88

8. ^ type III. .

. 86-67

66-88

1-67

—

8*61 a 97-78

These analyses lead to the formula 8Mg*0.3SiO* - Mg**SiH)*« -> 2MgK).3Hg«SiO«,
wherein part of the oxygen is replaced by fluorine ; or the mineral may be represented
as made up of the two compounds :

Mg>«Si«F". or 16MgF.3SiP« - A
and : Mg>*Si*0>«, or 8MgK).3SiO* - B

in various proportions, namely :

Ghondrodrite from Finland and North America ^ A + 12B

Homite ftom YesuTius, type L « — ^ + IBB

„ „ type n. 'm A + 27B

„ „ type UL » ^ + 36i3

Chondrodite occurs altered to serpentine at Sparta^ Kew Jersey, -with spinel and mica.
(Dana, iL 186.)

VWLOMmtOQMKm A name applied to the tissues which yield chondrin when
boiled with water, or rather to the substance which may be regarded as the basis of
these tissues.

OBOraBOmML Concretions occurring in the eavities and channels of the
animal body which are lined with mucous membranes, especially in the nose, gulleti
tonsils, and bronchi» : they are produced, under abnormal circumstances, from the
secretion of these membranes, their nucleus being jM>metimes a solid body accidentally
lodged in these cavities. They contain very variable quantities of -water and animal
matter, togetiber with 60 — 80 per cent, of phosphate of calHum, 6 — 20 per cent car-
bonate of oilcium, 8 — 12 per cent carbonate ox magnesium, and small quantities of
soluble salts. (Handw. d. Chem. ii [2] 1196.)

OHOVZOmZTB. A dense non-crystalline mineral from Elba, of specific gravity
2*91, hardness 3. Fracture oonchoidid. White. Translucent at the edges. Melts
with tolerable facility to a gBeyish-wfaite ^lass, evolving bubbles of gas at the same
time ; blue glass with cobalt-solution. Dissolves slowly in borax, yielding a glass
dighUy coloured by iron. Easily decomposed by concentoated hydrodiloric add, with
separation of silica, not in the usual gelatinous state. According to Kobeirs analysis,
it contains 12*6 lime, 22-5 magnesia, 1*46 ferrous oxide, 17*12 alumina, 36*7 silica, and
9*0 water, a composition whidi may be approximately represented by the formula :
9(2M*O.SiO*).2(2AlK)*.3SiO') + 12 aq., which by substituting a/ « } Al, may be reduced
to 3M*SiO\2di*SiO* •»- 4 aq. {RammeUber^s iiinaralchemie^ p. 868). Dana regards
chonicrito as a -variety of pyrosderite {q, v.)

OBXZSlttJkTZV* A -viscid translucent resin from Wettin near Halle, where it
occurs as a coating on calcspar in a fissure. It has a shining lustre, and varies in
colour from yellow to olive-green. Bums with flame and without odour. (Germar,
Deutsche geoL Zeitschr. L 40.)

k See Phiixipsitb.

Chromic add unites with nearly all bases. The salts are for
the most part easily crystallisable and isomorphous with the corresponding sulphates.
The chromates of the alkali-metals, and of strontium, caldum, and magnedum, are
soluble in water : the others are insoluble, or sparingly soluble.

With the alkali-metals, chromic add forms two series of salts, namely, neutral or
normal chromates, MGrO', or lIPCCrK)*, which are ydlow, and add diromates, com-
monly called bichromates, 2MGrO*.Cr'0', or M'0.2CrO*, which have an orange-red
colour: a hyperadd chromate, or trichromate of potassium, KCrO'.Cr'O', or E*0.3O'0',
is likewise known. These salts are produced, dther by direct saturation of the base
with chromic add, or by igniting chromic oxide with an alkali and a nitrate or other
oxidisinff agent

The insoluble chromates are obtained by predpitation. Most of them are bsde.
Those which contain 3 at banc metal to 1 at chromium, may be celled orthochro*

30 2

932 CHROMATE&

mates, IfCrO*, or ZWO.CrHy, the ordmazy neutral chromates MGrO*, wliieh differ
from, them by M'O, bein^ metuchromates.

A solution of an alkalme chromate gives with a salt of Intrium, lead, or bismMUk, a
yellow precipitate : with mtrcwroua salts a brick-red, and witb «t/«0r-8alts, a red-pmple
precipitate : all these precipitates are soluble in nitric acid. Chromates boiled vitfa
excess of hydrochloric acid, yield a green solution of sesquichloride of chrominin. A
chromate of alkali-metal boiled with sulphuric acid and a reducing agent, such as su^ar^
dcoholf or tartaric acid, yields a purple or a green solution of a chromic alum. Cbro-
mates heated with sulphuric acid and common salt, give off yeUowish-red Tapoors of
ozychlori 1e of chromium. The chromates of the less bssic metals give off oxygen
when ignited, and leave chromic oxide ; the acid chromates of the alkali-metals leave
a mixture of chromic oxide and neutral chromate. Insoluble chromates fused vitli
nitre, yield chromate of potassium, which may be dissolved out by water.

Chromates in solution have a bitter metallic taste, and a poisonous action.

Chbomatbs of Ammonium. — ^The neutral salt (NH^)CrO* is obtained by eva-
porating a mixture of chromic acid with excess of ammonia, or by decomposing duo-
mate of barium with sulphate of ammoniuuL Hirzel (Zeitschr. £ Pharm. 1852, p. 24),
gradually adds oxychloride of chromium to excess of ammonia, and evaporates the
solution at 60° C. Chromate of ammonium then ciystallises out, and may be purified
by recrjBtallisation. It forms lemon-yellow needles, permanent in the air; has a
pungent taste and alkaline reaction. It is very soluble in water. Leaves chromic oxide
when ignited.

Acid salt, 2NH*CrO«.Cr«0», or (NH*)*0.2CifO*— Obtained by dividing a solution of
chromic acid into two parts ; saturating one with ammonia, then adding the other, and
evaporating the whole over sulphuric acid. It forms orange-coloured ctystals, perma-
nent in the air, soluble in water, and yielding green chromic oxide when ignited.
(Richmond and Abel, Chem. Soc Qu. J. iv. 199.)

Darby {ibid, L 20), hj partially saturating chromic acid with ammonia and eva-
porating to the crystallising point, obtained a compound of ammonia with chromie
anhydride 2NH'.CrK)*, wluch may be regarded as a ehromamate of ammomum,

^ ^^4 [ 0, analogous to sulphamate of ammonium, vw* I ^'

Hyperacid salt, 2NH*CrO».6Cr»0»+ lOaq., or (NH*)*O.6Cr^«+i0aq.— Biown-yel*
low,' very efflorescent salt, obtained in ill-defined crystals by evaporating a station d
chromic acid half neutralised with ammonia. (Rammeisberg, Pogg. Ann, xeir.
607.)

A compound of chromic anhydride and sal-ammoniac, NH'Cl.Ci'O*, is obtained by
adding oxychloride of chromium to a strong solution of sal-ammoiliae, in eiyatab
having the same form and aspect as the corresponding potassium-compound, but modi
more soluble in water. (P^ligot, Ann. Ch. Phys. [2] lii 267.)

CsBOMATB OF Babium. — The neutral chromate, BaCrO', is prepared by pre-
cipitating chromate of potassium with chloride of barium or baiyta-water. It is in-
soluble in water, but dissolves, with reddish-yeUow colour, in nitric, hydrochloric, or
excess of chromic acid, and is precipitated from the solution by ammonia. It is de-
composed by alkaline carbonates and sulphates, even at ordinary temperatures, and
more quickly when heated. It is used as a pigment called yellow ultramarine.

Acid salt, 2BaCrO«Ci«0», or Ba«0.2Cr*O».— A concentrated solution of the neutral
salt in chromic acid is decomposed by dilution, part of the salt being precipitated^
while an acid salt remains in solution, and may be obtained by evaporation in yel-
lowish-brown stellate crystals, containing Ba'0.2Cr*0»+ 2aq., wluch dissolve slowly in
water, with separation of the neutral salt. (Babo, J. pr. Chem. Ix. 60.)

Chbomatb of Bismuth. — ^When a solution of nitrate of bismuth is added to a
moderately concentrated solution of acid chromate of potassium, leaving the latter
-slightly in excess, an egg-yellow, .flocculent precipitate is formed, which afterwards
becomes dense and crystallme. It consists of 3Bi«0».2CrK)* or 7BiK)».4Bi"'Gr»0«. It
is insoluble in water, may be dried without decomposition at 100^ to 125<* C, but ac-
quires a dark green colour when ignited, and retains this colour after cooling. It
dissolves in nitric or hydrochloric acid, forming a deep yellow liquid, whidi beoomes
turbid on dilution, from precipitation of basic nitrate or chloride of bismuth. If it be
treated with a small quantity of acid, a yellow salt remains undissolved, consisting of
BiH)».2Cr'0« or Bi«0».4Br"Cr»0«. The latter may also be obtained byprecipitiSng
acid chromate of potassium with a slightly acid bismuth-solution (J. I#dwe, J. pr.
Chem. Ixvii. 288, 463). According to Pearson {ibid. Ixviil 255), the precipitate
formed in the latter case is Bi'O'.Cr^', and is perfectly insoluble in water, so that \\
may be conveniently used for the estimation of bismuth.

CHROMATES. 933

Chboxatb 01* Cadxivii.— Aba8ic8alt,5Cd'O.2Ci'0* + 8aq.,or30dK).4CdCrO*

+ 8aq., is obtained as an orange-rellow precipitate, on mixing a cadmium-salt with

neutral cfaromate of potassium. On adding ammonia, the salt 2NH*CrO^(NH'Cd^H)

•I- 2aq. is obtained, which crystallises in transparent, bright-yellow, six-sided pyramids,

decomposing when exposed to the air or immersed in water.

GHBOXA.TB or Calciuh. — ^The nmtral salt CaCrO*+ a<^., is obtained by dis-
Bolyixig carbonate of calcium in aqueous chromic acid, or as a light yellow precipitate
by mixing concentrated solutions of chromate of potassium and chloride of calcium.
It is moderately soluble in water, insoluble in alcohol ; gives off its water at 200^ C,
and is afterwards very sparingly soluble. The anhydrous salt is used as a pispnent.
The acid-salt obtainea by dusolving the neutral salt in aqueous chromic aad and
eyaporating, forms red deliquescent crystals, containing 2CaCrO'.Cr*0'-}- 3aq.

Chromate of Calcium and Potassium, (KCa)Cr'O* + aq., obtained b^ saturating acid
chromate of potassium with hydrate of calcium, forms lemon-yellow, silky crystals.

Chboxatb of C^biux, CeCrO*, is deposited as a yellow powder from a solution
of carbonate of cerium in chromic add. The filtrate yields on evaporation an acid salt
in red prisms, soluble in water.

Chboxath of Chbomiux. — ^The brown oxides of chromium intermediate be-
tween the sesquioxide Cr*0', and chromic anhydride, Cr'O", may be regarded as com-
pounds of these two in various proportions, that is, as chromates of chromium. (See

C^mOXIUlC, OXIDBS OF.)

Chbgii ATB OF CoBALT. — Solutious of oobalt-salts form with chromate of potas-
sium, a light red-brown precipitate containing, according to Sarzeau and Malaguti
(Ann. Ch. Phys. [3] ix. 431), Go'CrO' + 2aq., which is the formula of an orthochromate.

Ghbomatbs of Coffbb. — ^When impure cupric hydrate is immersed in a strong
solution of chromic acid, a brown solution is formed which deposits a brown powder,
probably a tetrabasic salt, 4Cu»0.2CrH)», or 2CuH).4CuCrO« (Droge, Ann. Ch.Pharm.
ci. 89). The solution filtered through asbestos, and evaporated over oil of vitriol,
yields, after a while, ^preen crystals, consisting, according to Kopp {ibid. Ivii 386), of
cupric sulphate in which part of the sulphuric acid is replaced by chromic add (H^O*
bv HH>'0\ or S by Or*). The mother-liquor decanted therefrom, is free from sul-
phuric add^ and yields hj evaporation, a cid cupric chromate, 2Cu*CrO'.Cr^'
+ 2 aq., in brown-black, dehquescent crystals, soluble in alcohol and in ammonia. The
aqueous solution deposits on boiling a brown insoluble salt The crystals give off
their wat^r at 100^ C, and at a red heat the salt is completely decomposed. The
tetrabasic salt above mentioned is deposited as a chocolate-brown predpitate, contain-
ing 6 at. water, on mixing a boiling solution of neutral chromate of potassium with
bwic sulphate of copper. (Malaguti and Sarseau.)

An ammoTiuhchromate of copper, 6NH".Cu'0.4CuCrO* + aq., is obtained in dark green
prismatic crystals, by passing ammonia-gas into water in which tetrabasic chromate of
copper is suspended, and cooling the liquid below 0^ C. It soon gives off its ammonia
when exposed to the air : and is resolved by water into insoluble basic chromate of
copper, and a basic ammonio-chromate which dissolves in the water with emerald-
green colour. The same basic ammonio-chromate is obtained by treating acid cuprio
chromate with ammonia.

Chromate of Coj^per and Potassium, K*0.3Cu«0.3Cr*0« + 8aq., or CuHO.(KCu«
(VO* 4- aq., is obtained by treating recently predpitated cuprio hydrate with solution
of acid chromate of potassium, or by mixing a solution of cupric sulphate with acid
chromate of potassium, and gradually adding caustic potash. The product is a light
brown powder, consisting of microscopic, translucent, six-sided tablets, nearly insoluble
in water, but dissolving with deep green colour in ammonia or carbonate of ammo-
oium. The solution, if saturated while hot^ deposits on cooling green prisms having a
strong lustre.

Chboxatb of Gluoinvh is a yellow insoluble predpitate.

^ Chboxatb of Ibon. — Aqueous chromic add digested with moist ferric hydrate,
yields a brown solution, containing Fe*0*.4CiW. The solution is not rendered turbid
either hj dilution or by boiling, and yields on evaporation a brown resinous residue,
soluble in water and in alcohol. The basic salt is a brown powder, which is resolved
by water into ferric oxide and chromic add.

Chbomatbs of Lb ad. — The neutral or metachromate, PbCrO', is found native as
Red-lead ore, Crocoisite, or Lehmannite, in monodinic prisms, in which the ratio of the

_ . paralld to »P. Specific gravity

6*9 to 6*1. Hardness 2*6 to 3. The crystals are translucent and of a yellow colour.

3o 3

934 CHBOMATES.

with yarious shades of bright hyacinth-red ; streak orange-yellow. Sectile. ItocciUBza
deoompoeed gneiss or granite, at Nischne Tagilsk in the Ural, in Brazil, at Betzbanja
in Hungary, at Moldawa in the Bannat, and in Luzon, one of the Phillippine Ues.

Neutral chromate of lead is obtained as a light yellow insoluble precipitate, bj
mixing a dilute solution of a neutral lead-salt wim neutral or acid chromate of dcM^ks-
sium ; concentrated solutions yield an orange-yellow precipitate. It may also be ob-
tained by decomposing sulphate or chloride of lead with chromate of potassiam. It
is insoluble in water, slighUy soluble in nitric add, easily in potash. At a moderate
heat, it melts without decomposition to a brown mass, exhibiting a radiated structnze
when cold, and yielding a dark yellow, slightly hygroscopic powder. At a full red
heat, it gives off oxygen, and is reduced to a mixture of basic chromate of lead and
chromic oxide. Heated in a stream of hydrogen gas, it gives up 12 per cent, o^geo,
and is reduced to a mixture of chromic oxide and metidlic lead, which when heated
in a stream of oxygen takes up 7 per cent, of that gas. (On the use of chromate of
lead in organic analysis, see pp. 227, 232.)

Chromate of lead is much used as a pigment, known as chrome-yellow, also
Umon-yeUotD, Leiptig yeUow^ Paris yellow, &c. The finer sorts are prepared by preci-
pitation, the commoner kinds by decomposing carbonate, chloride, or sulphate of lead
(obtained as a by-product in the preparation of alum-mordants), with chiomate of
potassium. Accormng to Anthon, 100 pts. sulphate of lead require for decompomtion
25 pts. of red chromate of potassium, and 100 pts. chloride of lead require 27 pt&
of red chromate. Chrome-yellow exhibits various shades of red and yellow, aoccodiiig
to its mode of preparation : it is often mixed with chalk, gypsum, heavy spar, daj,
sulphate of lead, &c Cologne yellow is a mixture of chromate and sulphate of lead
witn sulphate of calcium, obtained by precipitating a mixture of the nitrates of lead
and calcium with a mixture of sulphate of sodium and chromate of potassium. It u
not altered by exposure to air or light ; sulphuretted hydrogen turns it brown ; proCo-
chloride of tin and sulphurous acid reduce it ; alkalis turn it orange or red, by rovma-
tion of basic chromate of lead. It is used as an oil or water-colour, for lacquering, and
may be mixed with many other colours without decomposition ; with Prussian bine it
forms a green mixture, called chrome-green, or green cinnabar. In calico-
printing, chrome-yellow is formed on the &brics themselves, by first steeping them in
a solution of lead-salt^ then in chromate of potassium. For dyeing silk and wool it is
not so well adapted.

Basic Chromate of Lead, — ^A dibasic or tetrapltmbic chromate^ 2Fb'0.Cr*0' »
PbK).2PbCrO*, known in the arts as chrome-red, is produced from the neutral
chromate by digesting it with caustic alkalis, or with levigated oxide of lead, or by
boiling it in the recently precipitated state with neutral chiomate of potassium, or by
fusing it with nitre. It is of a deep orange or red colour, according to the mode of
preparation. The finest vermiHon-red chromate is formed when 1 pt of chrome-yellow
IS thrown into 5 pt& of nitre in a state of fusion, and tiie resulting chromate of
potassium, together with the excess of nitrate, dissolved out by water: the basic
chromate of lead then remains in the form of a crystalline powder (Liebig and
W o hler). An orange pigment may be obtained very eoonomicallv, by boiling the sul-
phate of lead, which is a waste product in making acetate of tuumma from aium by
means of acetate of lead, with a solution of chromate of potassium. The basic chromate
of lead, forms a beautiM orange upon cloth, which is even more stable than the yel-
low chromate, not being acted upon by either alkalis or acids. One method of dyeing
chrome-orange, is to & the yellow chromate of lead in the calico, by dipfnng it
successively m acetate of lead and acid chromate of potassium, and then washing it.
This should be repeated, in order to precipitate a considerable quantity of the chiomate
in the calico. A milk of lime is then heated in an open pan ; and when it is at the
point of ebuUition, the yellow calico is immersed in it, and instantly becomes orange^
being deprived of a portion of its chromic acid by the lime, which forms a sdlnble
chromate of calcium. At a lower temperature, lime-water dissolves the chromate of
lead entirely, and leaves the doth white.

A ses^^uibasic or hexplumbic chromate, 3Pb»0.2Cr*0» - Pb«0.4PbCrO«, is found
native as MdanochrtfUe, Phanicite, or Phamikochrotte, at Beresof in the Ural, aaso-
dated with crocoisite, vauquelinite, pjromorphite, and |;alena. It occurs in tabular
crystals, apparently belonging to the tnmetric system, reticularly interwoven ; deaving
perfiBcfly in one direction ; also massive. Specific gravity 6'76, Hardness 3 to 3*5. It
has a resinous or adamantine, glimmering lustre, cochineal or hyadnth-red colour, be-
coming lemon-yellow on exposure to the air. Streak brick-red. Subtranslucent or
opaque.

A chromate of lead and copper, of analogous composition, viz. Qt | *0. 4 [q^ CtO*,

called Vauquelinite, occurs at Beresof, at Pont Gibaud in the Puy de D6me^ and

CHROMATES. 935

with the crocoisite of Brazil, in monoclimc ciystals, usually minute and irregularly
aggregated ; also reniform or botryoidal, and granular ; amorphous. Specific grayity
6'6 to 578. Hardness 2'5 to 3. It has a dark green to brown colour, sometimes nearly
black, with adamantine or resinous lustre, often faint Streak, siskin-green or brownida.
Faintly translucent or opaque. Fracture uneyen. Bather brittle. (I) an a, ii. 860.)

Chrohatb of LiTHiuic, LiCrO\ crystallises in orange-yellow, oblique rhombie
prisms, easily soluble in water.

Chbokatb or Maokbsivm, 2MgGrO' + 7 aq., obtained by eyaporating a solution
of magnesia in chromic acid, forms lemon-yellow crystals isomorphous with sulphate
of magnesiunL Specific grayity ^ 1*66 at 15° G.

Chromate of Mafftiesium and Amrnonium^ Mg(NH*}Cr'0^ + 8 aq., is isomorphous with
the corresponding sulphate.

Chbohatxs of Manoanbsb. — ^A manganic salt, 3(Mn^O'.Cr'0').Cr'0' + 6a^., is
precipitated on mixing sesquichloride of manganese with chromate of potassium.
(Fairrie, Chem. Soc Qu. J. iy. 300.]

A hatio Tnanganoua chromate, 2MnH).Cr'0'+ 2aq. BMn'0.2MnCrO', is obtained as a
crystalline predpitato on mixing manganous sulphate with neutral chromate of potas-
sium. It is brown, transluoenti and dissolyes with orange-yellow colour in sulphurio
and nitric acids (Waring ton, Vlnstitut, No. 518, p. 366. — ^Beinsch, Fogg. Ann.
ly. 97). According to Fairrie, it contains chromic oxide.

Chbomatbs of Mbbctjbt — Mercuric metachr ornate, HgCrO^ is obtained
by boiling equal parts of chromic anhydride and yellow mercuric oxide in water,
and gradually eyaporating till the mercuric oxide disappears, and red crystals are
formed in its place : the mother-liquor prields an additionaJ quantity by concentration.
It forms daxi garnet-red rhombic pnsms, becoming darker-oolourea when heated.
They are decomposed by water, eyen in the cold, and completely when heated, yield-
ing free chromic acid and amorphous mercuric orthochromate, HgHM)'. They dis-
Bobre readily in hydrochloric acid, and potash added to the solution throws down yellow
mercuric oxide, or perhaps the orthochromate. Strong nitric acid conyerts them, in
the cold, into an amorphous yellow compound, a large portion howeyer dissolying;
moderately strong nitric acid and dilute sulphuric acid act in the same manner, ex-
cepting that a larger quanti^ of the yellow compound remains undissolyed.

Mercuric orthochromate, Hg'CrO', or 3Hg'0.Cr'0', is obtained as a brick-red pow-
der on adding mercuric nitrate to add chromate of potessium ; or by boiling yellow
mercuric oxide with chromate of potassium (Millon^. It is also produced, together
with a less basic salt, by predpitating the mother-liquor of the metachromate with
carbonate of sodium. On ooiling the predpiteto with soda-ley, an amorphous, yellow,
heayy powder is predpiteted, which appears to consist of 7Hg*0.2CrO*, or
Hg^.4Hg'CrO'. The same salt appears also to be obtained by boiling recently pre-
cipiteted mercuric oxide with add chromate of potassium, till it is conyerted into a
brick-red powder, washing this powder repeatedly by decantation, and heating it with
moderately strong nitric add. It dissolyes in strong nitric acid only when recently
precipiteted ; strong sulphuric add, with aid of heat, conyerts it into white mercuric
sulphate; hydrochloric add does not dissolye it (Geuther, Ann. Ch. Pharm. cyi
244.)

A tetrabasic mercuric chromate, 4Hg*0.Cr*0«, or 3HgK).2HgCrO*, of dark yiolet or
brown colour, is said to be obtained by boiling red mercuric oxide with chromate of
potassium. When equiyalent quantities of basic mercuric chromate and solution of
cyanide of mercury and potassium are boUed together for some time, oxycyanide of
mercuiy separates firsts and afterwards a compound containing KHgCy' and HgOrO^
(Geuther.)

Mercuroui chromate, Hg^O.CiH)' « HhgCrO*, is obtained as a brilliant red
^ erystalline powder, by boiling tne basic salt next to be described, with a small quantity
' of dilute mtric add, or the double salt of cyanide of mercury and chromate of potas-
sium with mercurous nitrate.

Basic merouroue chromate, 2ngK).CrH)' » HhgH).2HhgCrO*, is obtained as a brick-
ted powder by predpitating mercurous nitrate with chromate of potassium. Both
these salts when heated, giye off oxygen and mercury, and leaye chromic oxide of a
beautiful green colour.

Chbomatbs of Moltbdbnum.— The neutral salt dissolyes in water with yel-
low colour, and fields by spontaneous evaporation, white, scaly, needle-shaped crystals.
The add salt dnes up to an amorphous brown mass. The solution of either salt mixed
with ammonia yields a precipitete of basic chromate of molybdenum.

Ghb^oxatb of NickbTm — Hydrate and carbonate of nickel dissolve in chromic
add with yellowish-red colour, forming an acid salt (Malaguti and SarzeaaV The

So 4

936 CHBOMATES.

Bolution of a neutral nickel-salt bofled with nentral cbromate of potaasiniii, yidds sb
amorphous precipitate, consisting of 3Ni*0.2NiCrO'+ aq., and having the oolom of
Spanish teinicco. If this or the soluble salt be corered with ammoniA, a heavj jel-
low-green crystalline powder, 3NH".NiCrO' + |aq. is formed, which is deo(nnpo0ed hy
air and water.

Chbpmatbs of Potassiux. — Three of these salts are known, tis.:

Neutral chromate, monochromateu or ) -trtrk /x-int trrL-nm
metachromate of potassium \ ^'O.CrH), orKCrO-

Add or dichromate . ... K«0.2Ci»0«, or 2KCrO«.Cr«0«

Hyperacid or trichromate . • . KH).30r*0», or KCrO«.Cr«0".

The nentral and acid salts are important articles of manufacture, being exteDsiTciiy
used in dyeing and calico-printing, and for the preparation of chrome-yellow ai^
chrome-red ; idso as oxidising agents : the acid salt is most used, because it ocMitaiDS
a larger percentage of chromic acid.

The chromates of potassium are prepared by igniting chrome-iron ore, a compoond
of sesquioxide of chromium and protoxide of iron, in contact with alkalis and oxidisiiig
agents, and lixiriating the fased mass with water. A yellow solution is thus obtained,
from which, by quick evaporation, the neutral salt is thrown down in yellow cxTstalline
granules ; and by redissolving this granular salt in water, and leaving the solution to
evaporate slowly, the salt is obtained in regular crystals. The concentrated solntion
of tne neutral chromate, treated with one of the stronger acids, yields the acid cbro-
mate ; and by evaporating the solution to the crystallising point, picking out the crystals
of acid chromate from the nitrate or other potassium-salt formed at the same time,
and recrystallising several times, the acid chromate is obtained in large tabular crystals
of an orange-red colour

The process first adopted for the preparation of chromate of potassium, was to cal-
cine the ore with nitre; but it may be rendered more economical l^ substitntuig
carbonate of potassium (pearlash) for a portion of the nitre ; and still more by dis-
pensing with the nitre altogether, and effecting the oxidation of the chromic oxide fay
means of air admitted into the reverberatory furnace in which the calcination takes
|dace. But whether nitre be used or not, the oxidation is still found to be impeffect^
because the alkali foBea into a thin liquid, and the chrome-iron ore, being very heavy,
sinks to the bottom, and thus remains to a great extent unaltered, especially when the
oxidation is effected by contact with the air, an inconvenience which is but imperfedly
obviated even by contmual stirring. But by adding lime to the mixture, as first pro-
posed by Stromeyer, it is rendered less fluid, and a moderate amount of stirrizig then
suffices to keep it well mixed, so that the oxidation takes place with mnch greater
facility. It is found, indeed, that when Ume is added, the nitre may be altogether dis-
pensed with, and its place supplied by carbonate, sulphate, or chloride of potassium,
which are cheaper. Mr. Tilgnman has patented a process for the use of felspar as a
source of alkali, 4 pts. by weight of that mineral J)eing calcined in a reverberatory
furnace, with 4 pts. of lime or an equivalent quantity of chalk, and 1 pt. of chrome-
iron ore. Mr. Booth of Philadelphia subjects the chrome-iron ore to a preHminaiy
ignition with coke or other carbonaceous material, whereby the iron is reduced to the
metallic state, then removes the iron by means of dilute sulphuric acid, and subjects
the chromic oxide thus purified, to calcination with alkali and nitre ; by this means,
the portion of oxygen which would be expended in converting the protoxide of iron
into sesquioxide, is rendered available for the production of chromic acid. The pro-
duction of sulphate of iron incidental to the process tends to defray the e3q>ense.

Jacquelain prepares acid chromate of calcium from chrome-iron ore, and converts
that salt into acid chromate of potassium by double decomposition. The chrome-ore,
after being ground to veir fine powder and sifted, is mixed with chalk in rotating
barrels, aikl the mixture is spread in a layer 1^ to 2 inches thick on the hearth of
a reverberatory furnace, heated to bright redness for nine or ten hours, and stirred
at least every hour. After this treatment, the mixture has a yellowish-green colour,
dissolves in hydrochloric acid, and with the exception of a certain (|uantity of sand,
consists essentially oi neutral chromate of calcium (CaCrO*) mixed with oxide of iron.
This mass is ground to powder by millstones ; the powder is stirred up with hot
water, and sulphuric acid is added till a slight acid reaction becomes apparent. The
neutral chromate of calcium is thereby converted into acid chromate^ The liquid also
contains sulphate of iron, which is precipitated in the same vessel by stirring up with
chalk, which does not affect the chrome-salt. The precipitate having settled down,
the clear solution of acid chromate of calcium containing a little sulphate is run o£^
and may be used, without further treatment, for preparing by double decomposition,
add chromate of potassium, chromate of lead, either neutral or basic, and chromate of

CHROMATES. 937

cine. To obtain acid duomate of potassium, the solution of add chiomate of calcium
is treated with carbonate of potassium, which throws down carbonate of caldum in a
form easy to wash, leaving add chromato of potassium in solution, which may then be
evaporated and crystallised. The chief advantages of this process are that it requires
less stirring than the ordinaxy method, even when lime is used, and that it avoios the
loss of alkali, which always ensues (to the amount of 9 or 10 per cent) when the mix-
ture of chrome-iron ore and potassium-salt is raised to a bright red heat. (For fiirther
details on the manu^itcture of alkaline chromates, see TJr^9 Dictionary of ArU,
Manufacttire9, and Mines, L 684 ; and Richardson and Watttt Chemieal Ttohnology
i [4] 69.)

a. Neutral Chromate of Potassium, KCrO*. — This salt is obtained by neutrali-
sing the add chromate with an alkali, or by igniting chrome-iron ore with excess of al-
kali (p. 936). It cnrstallises in double six-sided pyramids, belonging to the trimetric
system, and isomorphous with sulphate of potassium : hence it is capable of crystallising
with the latter in all proportions. It has a pale lemon-yellow colour, an alkaline re-
action, and a cooling, persistently bitter taste : it is poisonous even in small doses.
Sp^c gravity^ 2*705 (Kopp). 100 pts. of water at 15° C. dissolve 48^ pts. of this 2
salt, and in boiluiff water it dissolves m itll pyyp^F^jinnB- It possesses great colouring *
power, 1 pt. of it imparting a distinct yeJlow tint to 400,000 pts. of water, and a deep
yellow colour to 20 pts. of nitre when crystallised therewith. It is insoluble in alcohot
and IB predpitated oy iJcohol from its aqueous solution. The solution yields by eva-
poration, red crystals of the add chromate, and the alkaline mother-liquor after-
wards deposits yellow crystals of the neutral salt. The neutral chromate acquires a
transient red colour when heated, melts at a higher temperature, and solidifies in the
crystalline form on cooling. It is not decomposed by simple ignition, but when heated
to redness in contact with charcoal, sulphur, sal-ammoniac, and other redudng agents,

it forms chromic oxide together with a potassium-salt. It is decomposed by adds,
even by carbonic add, yieldbg the acid chromate of potassium. Sulphydric acid and
sulphide of potassium decompose it, with formation of chromic hydrate ; sulphurous
acid forms at first brown oxide of chromium, then a chromic salt. According to
Schweizer ( J. pr. Chem. xxxix. 267), arsenious add forms with it a gelatinous
mass, which after drying at 100° C. contains 4K«O.3CVO».3AsK)M0HH).

b. Acid Chromate, KK).2Cr*0« « 2KCrO«.CrK)«. Bichromate of Potash, Red
Chromate of Potash, — This salt is obtained by treating the solution of the>neutral salt
with one of the stronger adds, ^r by precipitating a solution of acid cliromate of
calcium with carbonate of potassium (p. 936). It separates hj rapid evaporation as
an oranffe-coloured crystalline powder, and by slower evaporation in splendid garnet-
red tables or prisms, belonging to the tridmic system. It is permanent in the air,
reddens litmus, has a cooling bitter, and metallic taste. Its powerful oxidising pro-
perties cause it to exert a poisonous action on the animal economy, both internally and
externally : the workmen engaged in its manufacture suffer greatly from malignant
ulcers. It dissolves in 10 pts. of water at 15° C, much more abundantly in boiling
water ; it is insoluble in alcohoL It melts at a heat below redness to a transparent
red liquid, which by slow cooling yields large fine crystals, having the same form as
those obtained from the aqueous solution, but crumbling to powder at lower tempera-
tures. At a white heat» it gives off oxygen, leaving neutral chromate mixed with
chromic oxide. Heated with charcoal, it is reduced, with slight detonation ; paper or
calico saturated with the solution and dried bums like tinder when heated. Faper
thus saturated acquires a darker colour by exposure to light, but remains unaltered in
the dark : hence it may be used in photography. Heated with strong sulphuric add
it gives off oxygen (about 16 per cent by weight), and yields water and potassio-
chromic sulphate (chrome-alum).

KHVO' + 4H«S0* « 2[(Cr*)'rKS»01 + 4HH) + 0».

It is also reduced when heated with sulphur or sal-ammoniac Sulphydrie add pre-
cipitates from its solution a mixture of chromic oxide and sulphur. Sulphurous add
colours it green without formins a precipitate, from formation of chromic sulphate and
hyposulphate. A solution of the salt in boiling hydrochloric add depodts on cooling
chromo- chloride of potassium (p. 938 )i The solution of add chromate absorbs a con*
siderable quantitf of nitric oxide^ acquiring a dark colour, and depomting after a while
brown oxiae of chromium.

A concentrated solution of the add chromate mixed with strong sulphuric add,
yields a deep red predpitate of chromic add.

A double salt, composed cistUphate and acid ehrofnaie of potassium, is obtained bj
mixing a concentrated solution of the add chromate with a quantity of sulphuric add
less than suffident to convert the potasdum into add sulphate. It oystallises on
cooling in stellate needles. (Reinsch.)

938 CHROMATES.

c By per acid Chromaie, or Triehromate of Potaatium, K'O.SQW,
KCrO^C^'O*, Beparates from a solntioii of the acid chromate in oidiiiaiy nitr^
prepared at 60° C^ in dark red naczeona prisma, of specific gra?i^f' 3-631, which
when exposed to the air, and melt at 145° — 160° C. (Graham.)

Chr ornate of Potassium and Ammonium^ E(NH*)Ci'0\ crystalliaes fiona a
concentrated solution of acid chromate of potassimn satnrated with ammowiii, and
cooled by a freezing mixtmre, or evaporated over Ume, in oystals appazentlj isDniar-
phons with snlphato of potastdnm : when exposed to the air, it gives off ammonia and
toms reddish-yellow. (Johnson, J. pr. Chem. Ixii. 261.)

Chromate of Potassium with Mercuric Chloride, ECrO*.2HgCl, is obtained
by mixing the component saltB in eqniyalent proportions, and adding sufficient hjdio-
chloric acid to redissolre the precipitate first produced. Small slightiy reddish cxT^tals^
which form a yellow solution in water. Another salt^ 2KCrO'.Gi^.2HgGl, is obtasined
in red spicolar oystals, by mixing acid duomate of potassiiim and mercuric chloride in
equiyalent proportions, and leaying the solution to eraporateL (Darby, Gheoi. Soe.
Qu. J. i 24.)

Chromate of Potassium with Mercuric Cyanide, 2ECrO'.dHgCy. — li^
yellow laminar crystala, obtained by evaporating a solution of 1 pt. neutral chromata o€
potassium and 8 pts. cyanide of mereury. (Darby.)

Chromo^hloride of Potassium, KCLCrK^^^^'^^%. This salt^ wfaidi is

analogous in com^KMition to the triacid chromate KGrO'.Cz'O', is obtuned by dissolTzi^
together, with aid of heat, 3 pts. acid chromate of potassium, and 4 pts. hydrodihsie
acid, avoiding evolution of chlorine. It crystallises in flat, red, rectangular prisms^ and
is decomposed by solution in water.

CHBOXA.TB8 OF SiLVBB. — The nsutral salt, AgCrO*, is obtained as a red pre-
cipitate by decomposing neutral chromate of potassium with nitrate of sQver, or by Vnl*
ing the acid silver^salt with water, whereby it is partly resolved into chromic acid asd
the neutral chromate, which then separates in crystals green by transmitted light, and
yielding a red powder. A solution of the acid salt in ammonia depositB the neatial
salt on evaporation, in dark green metallic crusts.

Acid Chromate of Silver, 2AgGrO'.Cr*0', is obtained bv immening metalfie afl-
ver in solution of acid chromate of potassium mixed with sulphuric acid, or by preczjn-
tating the same acidulated solution with a silver-salt It has the colour of carmine, is
partly soluble in water, and crystallises therefrom in tridinic prisms, having a dark
brown colour, r^ by transmitted light, and yielding a red powder.

Ammonio-chr ornate of Silver, 2NH'«AgOrO', separates from a hot solntaon of
chromate of silver in ammonia, in ydlow, square prisms, isomorphous widi tiie oone-
sponding salts of sulphuric and selenic acid : they give off ammonia when eipoeed to
tne air.

Chbokatbs or Sodiux. — ^Two of these salts are known, namely, the neutral
0&rofna^c,NaCrO',and ih^ acid chromate, 2NaCrO*.Cr*0'. Theyare analogous inall
respects to the neutral and acid chromates of potassium, and may be prepaid in like
manner. The neutral salt, which may also, according to Johnson (JT pr. Chem. hdi.
161 ), be obtained b^ saturating a solution of add chromate of potassium with carbonate
of sodium, and leaving it to evaporate at 0° C, crystallises at low temperatures ia yellow
transparent crystals, containing KaCiO'.5aq., isomoiphous with Glauber 'salt : they
melt at the heat of the hand, ddijuesce rapidly in the air, are easily soluble in water,
sparingly in alcohol, and when immersed in alcohol, become opaque from loss of
water. The aqueous solution evaporated at temperatures above 80° C, deposits the
anhydrous salt

Acid chromate of sodium^ 2NaCrO'.CrK)*, forms thin, hyadnth-red prismi^
very soluble in water.

Ohroxatb of Stbovtiuic. — ^Light yellow powder, obtained by nredpitatioB ;
soluble in hydrochloric, nitric, and chromic add ; rather more soluble m water than
the barium-salt,

Chbomates of Tin. — Stannic chloride forms with diromate of potassium a yel-
low precipitate, which becomes brownish-yeUow and translucent when dry, and passes
into violet stannic chromate when ignited.

Stannous chromate is predpitated in yeUow curdy flodcs, when stannous chloride
is added with stirring to exo^ of chromate of potassium. If the contrary course be
adopted, a greenish- white predpitate is formed, perhaps consisting of chromic stannatep
The salt leaves a violet residue when ignited.

Ubanio CHBOMATB.---nranie nitrate forms an ochre-yellow predpitate with
neutral chromate of potassium. The yellow rough-tasting solution of uramc carbonate
in aqueous chromic add, yields small fieiy-red ciystals. The salt melta at a gentle
heat, with partial decomposition.

CHROME ALUM — CHROME IRON ORE. 939

Chboxatb of VaVadiux. — The brovnisli-yeUow solation of Tanadic hydrate
in aqueous chromic acid, ^elds on eyaporation, a shining/ dark brown, Tamiah-like
mass, which dissolves partially in water, forming a yellow liquid.

Chboxatb of Yttbiuh. — Soluble salt, crystallising in small yellow prisms.

Ckboxatb of ZzNa — Sulphate of jsinc, mixed with neutral chromate of potas-
sium, forms a yellow precipitate of a baaio salt Malacuti and Sarzeau, by treating
carbonate of zinc with pure chromic add, obtained a yellow crystalline basic salt, con-
taining 4Zn*0.CrH)* + 6 aq., or Zn'CrO'.ZnHO + 2 aq. By boiling this salt with chromic
acid as long as anything cussolyes, the same chemists obtained a soluble non-crystalline
salt, 2Zn*0.3Cr»0*, or 4ZnCrO«.Cr*0«.

Ammonio-chromate of Zino, — The tetrabasic salt repeatedly treated with am-
monia, yields yellow cubic aystals, containing 2(ZnCrO*.NH') + 5 aq. Soluble chzomate
of zinc, 2ZnK).3Cr'0', treated with excess of ammonia and then with alcohol, yields a
copious precipitate, consisting of microscopic needles containing 5NH'.4i^CM)'+ 9aq.
(Malaguti and Sarzeau.)

Chromate of Zinc and Pota»siufH.-^The precipitate formed by chromate of
potassium in sulphate of zinc, if left for some time under the liquid, changes to an orange-
yellow powder, consisting of the double salt. It is sparinely soluble in cold water, but
imparts a yellow colour to a large quantity of the liquid ; in boiling water, it dissolves
widi deep yellow colour, with separation of a lighter coloured basic OEiit, Vfhen ignited,
it leaves a dark brown residue, from which water extracts neutral chromate of potassium,
leaving a compound of sesquiozide of chromium and oxide of zinc. (Handw. d. Chem.
ii [2] 1246.)

OBBOBia AXiim. This name is applied to the double sulphates of chiomiuqi
and the alkali-metals, analogous in composition to common alum and isomorphous

therewith, e.ff. ^poUutuMihT<ymie sulphate, K(Cr«)"'(SO«)« + 12HH) - ^?^^^| O* +

12H«0.

OBBOm 0XBBV. A name applied sometimes to green oxide of chromium,
sometimes to the pigment produced by mixing chrtme yellow with Prussian blue.
(See Chboxatb of Diad, p. 934.)

OBSOMB XBOV OMMm Chromic Iron, Chromate of Iron, ChromeiseMtein,
BSsefichrom, Ferrochromate, — This mineral, which is the most abundant ore of chromium,
usually ooctirs massive, with fine granular or compact structure, forming veins or im-
bedded massra in serpentine; more rarely in regular octahedrons, with imperfect
cleavage parallel to the octahedral faces. Specific gravity 4*32 to 4'57. Hardness 6*5.
Colour brownish-black, or iron-black. Streak brown. Lustre submetallie, inclining
to waxy. Opaque. Brittle, with conchoidal or uneven fracture. Sometimes magnetic.
Beforo the blowpipe it does not fuse, but becomes more strongly magnetic. With
borax or phosphorus-salt it fuses with difficulty, but completely, to a beautiful green
globule.

Chrome iron ore belongs to the spinel group of minerals, whose general formula is

H'O.R^O' or /^iN^'fO*. The monatomic metal is chiefiy iron, but magnesium is

generally also present in considerable quantity, and in some specimens a small portion
of the chromium appears to exist as chromosum. The sesqui-atomic metal R is
principally chromium, but it is replaced to a considerable extent by aluminium,
and sometimes also by iron (ferricum), so that the general formula of the mineral is

rw// fp . * pe* * ( ^' ^'^"^ ^® numerous analyses that have been made of it^ we se-
lect the following as samples of the different varieties : a, f^m Baltimore, Maryland,
by Abich (Fogg. Ann. xxxiii. 336); 6, from Yolterra, Tuscany, by Bechi (Sili Am.
J. [2] xiv. 62); r, from Texas, Lancaster county, Pennsylvania, by Franke (Bam'
mdeber^a Mineralchemie); d, from the same, by Garrett (Sill. AJm. J. [2] xiv. 46) ;
«, crystallised, from Baltimore, by Abich (ho, cit); /, from Beresow, Siberia, by
Moberg (J. pr. Chem. xliii 119) :

CHO» .

. 66-87

44-23

66*14

63-38

68-26

69-80

Cr«0 .

• — >

—

1-61

4-39

Fe*0« .

110

0*38

1206

—

...^

Fe^O .

. 1804

86-32

1802

88-66

2013

18-69

A1*0» .

. 18-97

20-83

6-76

11-86

10-93

Mg«0 . .

10*04

—

9*39

7-46

6-74

NiK) .

—

2-28

—

98-62 100*71 100-36 10432 99*29 100*46

940 CHROME-MICA — CHROMIUM.

Beeides the aboTe localities, chrome-iron ore is found in the islands of TTiist and Fetlar
in the Shetland group, in the D^partement du Yar in France, in Silesia and Bohemia,
at Boraas in Norway, near Kranbat in Syria, abundantly in Asia Minor and the
Eastern Urals, and in seyeral parts of North America. It assists in giving the green
coloor to verd-antiqae marble. The ore used in this country is obtained aueAj firom
the Shetland Isles, Norway, and Baltimore, the quantity amounting to 2000 tona an-
nually. (Dana, ii. 106; BammeUberg's Mineratcheinie^ p. 172.)

OKSOim-MZOA. This name was given by Breithaupt to an emerald-green
mica with nacreous lustre from the Pinzgau.

OBSOKX-OCKUi. Natiye chromic oxide.

I and OSXOBDi-TBabliOllir. See Chboxatbs ov Lbad (pi 934).
[C AXSIBm (pp. 931, 952). — OBSOBKTTB. Syn. with Cmtoxs-lBojr Obb.
Compounds of sesquioxide of chromium with protoxides (pi 951).
Symbol Cr. Atomic weight 26*2. — ^This metal was discovered by
Yauquelin in 1797. It is not yery abundant, and never occurs in the free state. It
is found as sesquioxide {chrome-ochre), as sesquioxide combined with protoxide of in>n
{chrome-iron ore\ as chromate of leawd (crocoisite or red lead-gpar, p. 934) ; in small
quantity in many iron ojes, and frequently in meteoric iron ; it is also the oolonriii^
principle of many minerals, as the emerald, green serpentine, olivin, &c.

The most abundant ore of chromium is chrome-iron. This mineral ignited with al-
kalis in presence of oxidising agents, yields a chromate of the alkali-metal; these salts
treated with acids and reducing agents yield sesquioxide of chromium ; and from thia
substance the metal itself^ and many of its compounds, may be prepared.
. Metallic chromium is obtained by reduction of the oxides or chlorides, as when ses-
quioxide of chromium is mixed with one-third of its weight of lamp-black or sugar-
charcoal and exposed in a crucible lined with charcoal to the heat of a blast ftimace;
the metal is thereby obtained as a whitish-grey mass, which cannot be melted together
into a button. F^Hgot, b^ heating the violet sesquichloride of chromium with potaa-
sium, obtained the metal m the form of a dark grey powder. Fr^my, by heating the
sesquichloride in a ^rcelain tube and passing vapour of sodium over it in a current of
hydrogen, obtained it in very hard shinine crystals. Bunsen, by electrolysing a solu-
tion of the sesquioxide, obtained the metiu in brittle laminae, havine the colour of iron
and metallic lustre. According to Bezzelius, when sesquichloride of chromium is
heated in an atmosphere of hy(&ogen, there is obtained, besides the protochloride, a
shininff deposit of metallic chromium.

Wdhler (Ann. Ch. Pharm. cxi. 230) obtains metallic chromium by reducing the
sesquichloride with zinc. One pt of the violet sesquichloride, and 2 pts. of a mixture of
the chlorides of potassium and sodium (7 pts. chloride of sodium to 9 pts. chloride of
potassium) are closely pressed into an ordinaiy earthen crucible, 2 pts. of zinc are laid
on the mixture, and the whole is covered with a layer of the flux. The crucible is
then gradually heated to redness, and the mass ia kept in a state of fusion, till a hiss-
ing noise is heard, and a zinc-flame is observed on removing the cover for a moment.
The crucible is then taken out, gently tapped to cause the metal to collect, and left to
cool. A good regulus of zinc is then found at the bottom covered with a green slag.
This regulus is well washed with water and digested in dilute nitric acid, which dis-
solves the zinc, and leaves the chromium in the form of a grey powder, which must be
purifled by again heating it with nitric acid and washing. By this method Wohler
obtained 6 or 7 grms. of metal from 30 grms. of the chloride, the calculated quantity
being 10 grms. Magnesium may be used in the reduction instead of zinc, but it oflfeis
no particular advantege. With cadmium as the reducing agent, a violent explosion
occurred.

Chromium obtained by Wohler's process is a light green, glistening, crystalline
powder, which, when macnifled flfty times, exhibits aggregates of crystals like fir-
branches, interspersed with individual crystals of tin-white colour, high lustre, and
specific gravity 6*81 according to Wohler, 7*3 according to Bunsen. These crvstals^
according to Wohler, have the form of a very acute rhombohedron ; but according to
Bolley (Chem. Soc Qu. J. xiil 334), who e>xamined them with a magnifying power
of 85, they are quadratic octahedrons with acuminated summits and bevelled terminal
edges, and very frequently united by fours in the form of a cross. This is the third
example known of an elementary body crystallising in the diinetric or quadratie
system, the others being tin and boron ; as a gener^ rule, ductile metals oystallise
in the monometric or regular system ; brittle metals in the hexagonal system.

Wohler^s chromium does not exert the slightest action on the magnetic needle.
When heated to redness in the air, it acquires a yellow and blue tarnish like steel, and
gradually becomes covered with a thin film of green oxide; but the oxidation is by no
means complete. Thrown into a spirit flame f^ with oxygen, it bums with sparuing.

CHROMIUM: BROMIDES — CHLORIDES. <Hl

bat not 80 brightljr as iron. On melting chlorate of potassium it bums with dazzling
white light Melting nitre oxidises it Teiy readily, but without incandescence. In
melting carbonate of sodium it remains unaltered. Heated in chlorine gas, it exhibits
vivid incandescence. It is but superficially converted into green oxide by ignition in
a stream of aqueous vapour free firom air. Hydrochloric acid dissolves it readily, with
evolution of hydrogen, forming blue chromous chloride. Dilute sulphuric acid does not
act upon it at ordinary temperatures, but on applying a gentle heat, a violent action
suddenly takes place, and the remaining metal acquires the power of dissolving easily
in the most dilute sulphuric acid, even after washing. It is not attacked by nitrio
add, either concentrated or dilute. (Wo h 1 er.^

The properties of chromium differ consideraoly, according to the manner in which
it is prepared, the peculiarity doubtless depending chiefly on the atate of aggregation.
P^ligot's chromium oxidised with greftt fifunlity, taking fire in the air, even at a heat
below redness, and being converted into green ses(^uioxide. It likewise dissolved in
dilute sulphuric and hydrochloric acids, and was oxidised by nitric acid.

The aystals of chromium obtained by Fr^my belong, according to S^narmont, to the
regular system. They were not attacked by any add, not even by nitromuriatic add.

Chromium mav be polished, and then acquires a fine metallic lustre. When pure it
is even less fusible than platinum (Deville, Polyt CentralbL 1867, p. 605). A frag*
ment of it scratches glass ; it is at least as hard as corundum.

Chromium unites with bromine^ chlorine^ fluorine, iodine, cyanogen, nitrogen, oxygen,
phosphonu, and mlphur, also with aluminium and iroTi, There are two classes of
chromium-compounds, into which the chromium enters as the positive or basic ele-
ment,
Cr»SO^
Cr*(SO\
atomic, and to this there corresponds a class of salts, the chromates, into which the

Cr'")
chromium likewise enters as a triatomic radide, e. g, chromate of lead, p, [ 0*.

OBBOMXUlCp aBOMTPM OV« The anhydrous seequibromide, Cr'Br', may be
prepared, like the chloride, by passing bromine-vapour over an ignited mixture of
chromic oxide with charcoal ana starch-paste. Part of the resulting bromide then
sublimes beyond the mass of oxide, while another portion remains therein in crystal-
line scales, which, however, are easy to separate. It forms black semi-metallic hexa-
gonal scales, translucent with olive-green colour, and exhibiting in one direction a
faint red dichroism. It forms a yefiowish-green powder when triturated, in which
form also part of the compound sublimes during the preparation. It is quite insoluble
when pure, but dissolves to a green liquid if mixed with protobromide. It is decomposed
by alludis more easily than the chloride. When gently heated in hydrogen gas, it is
reduced to the white protobromide, CrBr, which on exposure to the air quickly de-
liquesces to green ox^'oromide. (Wohler, Ann. Ch. Pharm. IxL 382.)

A solution of chromic bromide is obtained by dissolving chromic hydrate in hydro-
bromic add, or by treating chromate of silver with hydrobromic add and alcohoL
The solution yields green crystalsi and is easily decomposed by evaporation, with form-
ation of oxybromide.

OKSOmUMt OR&OSXBB0 OV. Two chlorides of chromium are known in
the free state, viz. CrCl and Ci'Cl'. A trichloride, CrCl', may also be supposed to
exist, combined with chromic anhydride, in chlorochromic anhydride, CrCl'.Cr'O'.

Pbotochlobidb OF CHBOXixrxorCHROXOUs Chlobidb. CrCl. (Moberg,
J.pr. Chem. xxix. 176; P^ligot, Ann. Ch. Phys. [31 xiL 627.)-^This compound is ob-
tained by passing hydrogen gas over perfectly anhydrous sesquichloride of chromium
very gently heat^, as long as hydrochkric add gas continues to escape. The hydrogen
must be previously freed from all traces of oxygen by passing it through a solution
of protocnloride of tin in caustic potash, then through tubes containing sulphuric acid
ana chloride of caldum, and lastly over red-hot metallic copper. The protochloride is
also formed by passing dry chlorine gas over a red-hot mixture of charcoal and chromic
oxide. The first method yields the protochloride in the form of a white, velvetv sub-
stance, retaining the form of the sesquichloride from which it has been formed ; the
second method yidds it in fine white crystals, usually mixed, however, with chromic
oxide, chromic chloride, and charcoaL

Protochloride of chromium dissolves in water, with evolution of heat, forming a blue
solution, which rapidly turns green when exposed to the air or to chlorine gas. With
potash it forms a dark brown precipitate (yeUow, according to Moberg, if the air be com-
pletely exduded) of hydrated chromous oxide, which, however, qnicUy changes to light
brown chromosochromic oxide, with evolution of hydrogen. Ammonia forms a sky-
blue precipitate, which turns green on exposure to the air. With ammonia and sal-
ammoniac, a blue liquid is formed, which turns red on exposure to the air. Sulphido

942 CHROMIUM: CHLOBIDES.

of ammonium or potatsium forms a black precipitate of chromoos solphide. The solu-
tion of protochlonde of chromium is one of the most powerfol deoxidising agents kziovn.
With a solution of neutral chromaie of potassium, it forms a dark brovn precipitate
o^chromosochromic oxide, which, howerer, disappears on the addition of an exeeas
of the protochloride, and forms a green solution. It precipitates ealomd from a solu-
tion of oonosive sublimate. With cuprie salts, it forms at first a vhite precipitate at
cuprous chloride, but when added in excess, throws down red cuprous oxide. It in-
stantly converts tunastic acid into blue oxide of tungsten, and precipitates gold from
the solution of the chloride.

A solution of chromous chloride containing zinc, may be obtained, aeooiding to
Loewel (J. pr. Chem. Ixii. ll)f by pouring a solution of the sesquichloride^ or of
chrome-alum, in 3 to 5 pts. water, made as neutral as possible, into a bottle neaiij
filled with granulated zinc. Hydrogen is then eTolved for some hours, and a fine blue
liquid is formed, which, if left to stand in contact wit^ the zinc, continues slowiy to
evolve hydrogen and deposit a light grey chromous oxychloridei, and after fonr or sax
months becomes perfectly colourless.

Sbsquichlobidb OF Chbokiuil Chromic Chloride. Ci'CP. — The anby-
drous sesquichloride is prepared by igniting an intimate mixture of chronuc oxide and
charcoal in a stream of dry chlorine gas. A mixture of the oxide with lamp-black is made
up into pellets with starch ; these are well baked in a covered crucible, and then in-
troduced into another crucible, through the bottom of which there passes a porcelain
tube connected with an apparatus for evolving chlorine. Into the mouth of this crocible
is fitted a smaller one, placed in an inverted position. The lower cmeible stands on
the grate of an ordinary air-famace, and, as soon as the apparatus is filled wiUi dry
chlorine, the mixture is heated to bright redness, the firing being so regulated as to
keep the upper crucible comparatively cool, so that the chloride as it is prodoced may
sublime into it When the process is completed, the stream of chlorine must be kc»t
up till the apparatus is cool, to prevent the formation of sesquioxide or protochloride.
The sesquichloride is then washed with water to free it from chloride of alnmininm
deriv^ from the crucible. If it contains protochloride, which is the case if the sbieam
of chlorine has not been strong enough, it will dissolve during washing (Wohler, Pogg.
Ann. xi. 148). The sesquichloride may also be obtained by beating the sesqnisn^ihide
in a stream of dxy chlorine. (Berzelius.)

Anhydrous chromic chloride forms shining micaceous laminee of a beantifdl peach-
blossom colour, which mav be rubbed on me skin like talc It Is quite insoluble in
cold water ; but, if boiled m the finelv divided state with water, it slowly dissolTes and
forms a green solution. If the cold water contains in solution a small quantity c^
chromous chloride, not even exceeding j^ to -^^ the sesquichloride dissolves imme-
diately, with evolution of heat, forming a green solution identical with that obtained
by dissolving chromic hydrate in hydrochloric acid. This effect is perhaps due to the
formation of an intermediate chloride, which is immediately resolved by the action of
water into protochloride and the soluble p;reen modification of the sesquichloride^ the
protochloride thus liberated again acting m the same manner (see p. 943). The addi-
tion of a small quantity of stannous or cuprous chloride is said to produce the same
effect.

Anhydrous chromic chloride is not decomposed by sulphuric aad, either strong cft
dilute, or by hydrochloric, nitric, or nitromuriatic acid, or by ammonia, carbonate of
potassium, or carbonate of sodium : eaustie potash attadLS it but slightly at the boiling
neatw FuJsed with nitre and an alkali or al%aline carbonate, it yields a chromate and
chloride of the alkaU-metaL Potassium, zinc, &c., separate metallic chromium from
it Heated in a stream of hydrogen, it yields chromous chloride, and if the heat be
strong, metallic chromium is likewise separated. Heated to redness in theoiV, it gives
off chlorine and yields green chromic oxide. By ignition in phosphoretted hydrogen
gas, it is converted into phosphide of chromium. Heated with sulphur, or in a stream
of sulphydric acid gas,^ it yields sulphide of chromium. Ignited in ammonia gas, it
forms nitride of chromium.

By dissolving chromic oxide in hydrochloric add, or by boiling ehromate of lead or
silver with hydrochloric acid and alcohol, or even with excess of hydrochloric acid alone^
a green solution is obtained, containing the modification of chromic chloride which ocv-
responds to the green chromic oxy-salts (p. 950). This solution, when evaporated,
yields a non-ciystelline dark green syrup, which, when heated to 100^ C. in a stream
of dry air, yields a green mass containing 2Cr*Cl'.9H*0 (Mob erg, J. pr. Chem. xxix;
175). The same solution evaporated in vacuo yields green granular crystals containing
Cr«Cl».HK). (P^ligot, ibid, xxxvii 475.)

Hydrated chromic chloride heated to 250^ C. in a stream of hydrochlorie add or
chlorine gas, gives off its water and yields delicate peachblossom-coloured scales, which
are soluble in water and even deliquescent ; but^ if more strongly heated in either of

CHROMIUM: DETECTION AND ESTIMATION. 943

these gases, it begins to sublime, and the sublimed chloride thns obtained is insoluble
in water, like that obtained by igniting chromic oxide with charcoal in a stream of
chlorine. The anhydrous chloride cannot be obtained by heating the hydrated chloride
in the air : for hydrochloric acid is then giyen off and soluble ozycmoride produced,
afterwards an insoluble ozychloride, and the residue ultimately consists of green
chromic oxide. In this respect> the hydrated sesquichloride of chromium resembles the
corresponding compounds of iron and aluminium.

Nitrate of silyer added to a green solution of chromic chloride, throws down at first
only ^ of the chlorine ; but on leaTing the liquid to stand, or on boiling it^ the whole
of uie chlorine is precipitated. This effect was attributed by BerzeUus to the tendency
of chromic chloride to form double salts ; by Otto to the solubility of chloride of silver
in chromic nitrate.

A solution of chromic chloride, corresponding to the yiolet solutions of the chromic
salts of oxygen-acids, may be obtained by precipitating one of these yiolet salts by an
alkaJi, and dissolving the precipitated hydrate in hy<uochloric acid ; also by decom-
posing the yiolet sulphate with chloride of barium. From these solutions nitrate of
silyer immediately tnrows down all the chlorine. If^ however, the yiolet solution of
the chloride be boiled, it turns green, and after this change the chlorine is but partially
precipitated by nitrate of silver. *

Chromic chloride unites with the chlorides of the more basic metals, forming salts
containing MCLCr^l', or MCr^*, of which however only the potassium, sodium, and
Hmmonium-compounds have been investigated. They are obtained by mixing the cor-
responding add chromates with excess of hydrochloric acid and alcohol, and evaporating
over the water-bath till the mass turns violet. The double chlorides thus obtained
become green and deliquesce on exposure to the air. Treated with a small quantity
of cold water, they dissolve, with deep yellowish-red colour, which in a short time
passes into pure chrome-green. If the solution be then left to evaporate, the alkaline
chloride separates out, and the chromic chloride remains in the form of a green syrup.
These double chlorides belong therefore to the yiolet modifications of chromic salts, but
are decomposed by water into chloride of alkali-metal and green chromic chloride,
which does not form double chlorides. The effect of chromous, stannous, and cuprous
chlorides in facilitating the solution of anhydrous chromic chloride in water (p. 942)
probably depends upon the formation of analogous double chlorides. If the double
chloride decomposed by slow evaporation be mixed with hydrochloric acid and evapo-
rated to dryness over the wateivbath, the double chloride is reproduced. When the dry
double chlorides are treated with absolute alcohol, green chromic chloride dissolves,
and a rose-coloured salt remains, consisting, according to Berzelius^ of SMCLCr'Cl'.

CrsmOMIUM, BBTBCTZOV A»B mmTSaULTtOK OV. l. All compounds
of chromium ignited with a mixture of nitre and an alkaline carbonate j\ei6. a chromate
of the alkali-metal, which may be dissolved out by water, and on being neutralised
with acetic acid, will give the characteristic precipitates of chromic acid with lead and
silver-salts.

The oxides of chromium and their salts, fiised with borax in either blowpipe flame,
yield an emerald-green glass. The same character is exhibited by those salts of
chromic acid whose bases do not of themselves impart decided colours to the bead.
The production of the green bead in both flames distinguishes chromium from ura-
nium and vanadium, which give green beads in the inner flame only.

2. Reactions in Solution, — The sesqui-salts of chromium or chromic salts
exhibit two principal modifications, the green and the violet. Ammonia produces in
solutions of the green salts, a greyish-^reen precipitate ; in solutions of the violet salts,
a greyish-blue precipitate, both of which however yield green solutions with sulphuric
or hydrochloric acid. The liquid above the precipitate has a reddish colour, and con-
tains a small quantify of chromic acid. Potasn and soda form similar precipitates,
which dissolve in excess of the alkali, forming green solutions from which the chromic
oxide is precipitated by boiling. The alkaline carbonates form greenish precipitatefl
^olet by candle-light) which dissolve to a considerable extent in excess of the reagent>
Stdph^dric acid forms no precipitate ; sulphide of ammonium^thiowB down the hydrated
sesquioxide.

ZinCf immersed in a solution of chrome-alum or sesquichloride of chromium,'ezcluded
from the air, gradually rieduces the chromic salt to a chromous salt, the liquid after a
few hours acquiring a fine blue colour, and hydrogen being evolved by decomposition
of water. If the zinc be left in the liquid after the change of colour from green to blue
is complete, hydrogen continue to escape slowly, and the liquid, after some weeks or
months, is found no longer to contain chromium, the whole of that metal being pre-
cipitated in the form of a basic salt, and its place taken by zinc Tin, at a £)iling
heat, likeiKise reduces the cliromic salt to a chromous salt, but only to a limited extent ;

944 CHROMroM : ESTIMATION.

and on learing the liquid to cool after the action has ceased, a contraiy action takes
place, the protochloride of chromium decomposing the protochloride of tin prerno-asLy
formed, reducing the tin to the metallic state, and being itself reoonrerted into sesqni^
chloride. Ironaoes not reduce chromic salts to chromous salts, but merely pn^pitatea
a basic sulphate of chromic oxide, or an oxychloride, as the case may be.
Chromous salts are but rardj met with in solution : for their chanieteiB, see Piboto-

CHLOBIDB OF ChSOKIUM (d. 942).

Chromic acid and its salts are recognised in solution by forming a pale yellov pre-
cipitate with barium-salts, bright yellow with ^eoc^salts, brick red with mercurous-eilta,
and crimson with silver-Balis (p. 932).

3. Quantitative Estimation. — Chromium is usually estimated in the state ai
sesquioxide. When it exists in solution as a seequi-salt» it may be precipitated by
ammonia, care being taken to avoid a large excess of that reagent (which would difSolTe
a portion), and to heat the liquid for some time. The chromic oxide is then com-
pletely precipitated, and the precipitate, after washing and drying, is reduced by
Ignition to the state of anhydrous sesquioxide, containing 69*1 per cent, of ih€ metaL

When chromium exists in solution in the state of chromic acid, it is best to precipt>
tate it by a solution of mercurous nitrate ; the mercurous chromate thereby tJirown
down yields by ignition the anhydrous sesquioxide. The chromic acid might also be
precipitated and estimated in the form of a barium or lead-salt.

Chromic acid may also be estimated by means of oxalic acid, which reduces it to
sesouioxide, being itself converted into carbonic add. The quantity of carbonic anhy-
driae eyolved determines the quantity of anhydrous chromic acid present^ 3 at. CO*
corresponding to 1 at. Cr*0', as shown by the equation :

2Cr*0« + 3CB*0« - Ct*0* + 6C0« + 3HK).

The mixture may be heated in the carbonic acid flask represented in Jiff. 5, p. 119.
If the object be merely to determine the quantity of chromium present, any salt of oxalic
acid may be used; but if the alkalis are also to be estimated in the remaining Hqnid,
the ammonium or barium-salt must be used.

Lastly, chromic acid may be estimated by Bunsen's volumetric method. The chramie
acid is decompcMed by boiling with excess of hydrochloric acid, whereupon 1 at. efaronde
anhydride eliminates 3 at chlorine :

Cr'O* + 6Ha « Cr»Cl« + 8HH) + Cl«;

and the 3 at. chlorine passed into a solution of iodide of potassium, liberate 3 at.
iodine, which is estimated by a standard solution of sulphurous acid, as described under
VoLUXSTBio ANAI.TSIS (p. 264), BO that 3 at iodine correspond to 1 at CrK)*.

4. Separation of Chromium from other Elements. — Chromic oxide, in
the state of neutral or acid solution, is easily separated from the alkalis or aikalins
earths by precipitation with ammonia, care being taken in the latter case to protect the
liquid and precipitate from the air. The same method, with addition of sal-ammoniac^
serves to separate chromic oxide from mtwiesia. Tha separation from the alkaline
earths and from magnesia may also be effected by precipitating the whole with an
alkaline carbonate, and igniting the precipitate with a mixtoro of carbonate of sodium
and nitro. The chromium is then converted into chromate of sodium, which may be
dissolved out, and the solution, after neutralisation with nitric or acetic add, treated
with mercurous nitrate as above.

From alumina and glucina^ chromic oxide may be separated by treating the solution
with excess of potash, and boiling the liquid to precipitate the chromic oxide. The
separation is, however, more completely effected by fusing with nitre and carbonate of
sodium, treating the fused mass with water, adding an excess of nitric add to dissolve
anything that may be insoluble in water, and predpitating the alumina or gludna hj
ammonia.

Another metHod of converting chromic oxide into chromic add, and thereby efiectmg
its separation from the above-mentioned oxides, is to treat the mixture with excess of
potash, and heat the solution gently with peroxide of lead. The whole of the chro-
mium is then converted into chromic acid, and remains dissolved as chromate of lead
in the alkaline liquid ; and on fQtering from the excess of peroxide of lead, and any
other insoluble matter that may be present, and supersaturating the filtrate with acetie
acid, the chromate of lead is predpitated. (Chancel, Compt. rend, -gliii 927.)

Chromic acid may be separated from the alkalis in neutral solutions by pred|ata-
tion with mercurous nitrate ; also by reducing it to chro^pic oxide with hydrochloric add
and alcohol, and predpitating by ammonia. From the earths it may also be separated
by this latter method, or, again, by fusing with carbonate of sodium, dissolving out
with water, &c

From t>o«, einc^ nickel, cobalt, uranium, and cerium, chromium may be separated by

CHROMIUM: ESTIMATION OP. 915

t foaion with nitre and carbonate of sodium, or with the car1x>nate alone if it is already in

I the form of chromic acid. Or, again, the separation may be e£fected by means of potash

t and peroxide of lead, according to Ghancelf s method above described,

I The separation of dumnium from manganese cannot be effected immediately in this

manner, because the manganese is at the same time converted into manganate or ^er-
I manganate of sodium ; but on dissolving in water and adding alcohol to the solution,

the manganese is reduced to peroxide and completely precipitated, while the chromium
remains dissolved as chromate.

From titanium^ tantalum, and columbiunif chromiuni, if in the state of sesquioxide,
may be separated by fusing the mixture with nitre and alkaline carbonate, extracting
with water, reducing the (Siromium to the state of sesquioxide by boiling with hydro-
chloric acid, and precipitating by ammonia.

From copper, lead, tin, and the other metals of the first groop (p. 2VJ), chromium
\ is separated by sulphydric acid.

To estimate chromic acid in presence of aulphurio acid, the chromium is first re-
^ duced to sesquioxide as above ; uie sulphuric acid is then precipitated, after conside-

- rable dilution, by cMoride of barium ; the excess of barium is removed by sulphuric

add : and the chromic oxide precipitated by ammonia.
' When Tahoephoric acid is present in solution, together with chromic acid, the phos-

\ phoric acid is precipitated aa phosphate of magnesium and ammonium, and then the

chromic acid by any of the preceding methods.
I Hydrochhrie acta is separated from chromic add by nitrate of silver, and the excess

K of silver is removed by sulphurotted hydrogen, the chromic add being at the same

time reduced to sesquioxide, which may be predpitated by ammonia.

Silicic acid is separated firom diromic aad in the same manner as from all other
substances, and the chromium is afterwards precipitated as oxide.

When sesquioxide of chromium and chromic acid occur together in solution, the

chromic add may be predpitated by mercurous nitrate, the solution being first com-

^ pletely neutralised, ana the sesquioxide predpitated from the filtrate by ammonia,

1 which at the same time throws down a mercuiy-compound, to be afterwards separated

from the chromic add by ignition.
t- Valuation of Chrome'Ores. — The value of a ehrome-ere depends upon the

I quantity of chromic add that it will ^eld. To ascertain this point, tJbe oro is c^ldned

with a mixturo of nitro, alkali, and lime, the use of the lime being to keep the mixturo
in a pastpr condition, and prevent the heavy ore from falling to the bottom (see p. 936),
after which the soluble chromate is extracted, and the amount of diromic acid may*
I then be determined by any of the methods already given.

' Professor Calvert of Manchester, has given two processes for the valuation of chrome

' ores. (Chem. Soc Qu. J. v. 194.}

I a. The oro in fine powder is mixed with three or four times its weisht of soda-lime

(obtained by slaking quick lime with caustic soda, then drying and calcming the mass),
and to this mixture of soda-lime and oro is added one-fourth of nitrate of sodium. The
whole is then well calcined for two hours, caro being taken to stir the pasty mass
every quarter of an hour with a platinum wire. This mixturo not becoming fiuid, the
oro 18 constantly kept in contact with the oxygen of the atmosphere, and thus the oxide
of diromium is converted into chromic add. One treatment is generally sufi^ent for
the complete decompodtion of the oro.

The greater part of the mass is now dissolved in water, and the insoluble portion
treated with sulphuric add diluted with twice its bulk of water; the whole is then re-
moved from the crudble, and a little alcohol is added to the solution in order to ronder
the sulphate of caldum insoluble. The whole is next thrownon a filter and washed with
weak alcohol, which dissolves all the add chromate formed, and leaves the sulphate of
calcium, together with any portion of oro that may not have been attacked. The sul-
phate of caldum ma^ be romoted by washing Che filter with boiling water, and the
residual ore, if any, is to be recaldned.

The solution containing the acid chromate of sodium is now neutraUsed with
ammonia, and oxalate of ammonium is added, which gives rise to a small predpitate of
sesquioxide of iron, alumina, and oxalate of caldum, together with a little siUca dis-
solved by the sulphuric add. The predpitate having been separated and well washed,
the liquor is either mixed with alcohol to roduce the chromic add to the state of ses-
quioxide, which may then be predpitated, wasQied, dried, ignited, and weighed ; or,
better, the liqtior is rondered ad(C and the amount of chromic acid estimated by
Pennv's process (Chem. 8oc. Qu. J. iv. 239) witii dichloride* of tin (commonly called
protochloride). This method depends on the reaction of dichloride of tin with add
chromate of sodium on potassium in presence of free hydrochloric add, wheroby

• Atomic weight of tin a 118.
Vol. L 3 P

^ I

946 CHBOMIUM: FLUORIDES.

the dichloride of tin is ooDTerted into tetnehlondeb and the ehiomis add into
chloride of chromium :

3SnCl« + 2NaCrO*.C5r«0» + 14Ha - 88na* + 2Naa + 7H«0 + 2Cr»CP.

A solution of dichloride of tin of known streneth* is added to the Bolntion of acid
chromate of sodium, till the latter is completely decomposed, — ^which may be known bj*
the solution no longer giring a yellow precipitate with acetate of lead — and t^
quantity of acid duomate present is calciuated from the amount of tin in the aolntiasi
used. I^ennj has shown, by direct experiment^ that in the aboTC reaction, 100 pts^ of
metallic tin correspond to 83*2 pts. of add chromate of potassium, or 78*4 pts^ of add
chromate of sodium.

b. The finely divided ore is calcined with nitnte of barimn, a small qmantity of
caustic potash being added towards the end of the operation tofarilitate the action, mad
give rise to chromate of potassium. The pasty condition of the fused baryta prerents
the ore from fiiUin^ to the bottom, and thus keeps it in contact with the air. On coding
the crudble and its contents are immersed in dilute nitric add, which dissolvee the
greater portion of the mass, learing the unattacked ore, which, after being washed,
may be recalcined. The Uquor containing the add chromates of potaoaima and
barium, nitrate of barium, sesquiozide of iron, alumina, and lime, is fint heated with
sulphate of potassium, which throws down the baryta as sulphate, which is collected on
a niter and washed ; ammonia and oxalate of ammonium are then added to thivw
down sesquioxide of iron, alumina^ and lime ; the mixed predpitate U collected and
washed ; and the amount of chromic add determined as bdbre.

6. Atomic Weight of Chromium.— "BeneSHxtB, in 1818 (Schw. X zxiL 6S), esti-
mated the atomic weight of chromium from the compodtion of chromate of le^d. 100
pts. nitrate of lead (containing 67*31 FbH)), yielded bypredpitation with chzomaie of
potasdum, 98*772 pts. Pb*O.CrK)*; whence, taking the atomic weight of lead at
103*59, that of chromium was found to be 28*14.

P^ligot, in 1844 (Ann. Ch. I'hys. [3] xu. 628), showed that this number was too
high. From the analysis of chromous cmoride, CiOl, in which he found 66'7 to 68*4
per cent chlorine, and likewise from that of the acetate, he estimated the atomic weight
of chromium at 26*24.

Berlin (Ann. Ch. Fharm. Iri. 207 ; Ix. 182), analysed duomate of siItct b^ pre-
dpitating the silver with hydrochloric add, then reducing the chromic add in the
filtrate to diromie oxide, and predpitating by ammonia. From the quantity of chloride
of sUver obtained (Agsl08; CI » 36*206), he found, as a mean of fiye experiments,
Cr» 26*34, and by comparing the quantity of chromic oxide predpitated with the
original quanti^ of chromate of silyer, Cr» 26*27.

Berlin likewise adopted the method of BeneUus^ and fcmnd. that 100 pta. nitmte of
lead yield from 97*569 to 97*694 pts. chromate of lead, whence, as a mean zesnlt,
Cr« 26*99.

Moberg, in 1841 (J. pr. Chem. xliii. 114 ; xliv. 322), estimated ike atomic weight
of chromium by the analysis of chromic sulphate and of ammoniacal chrome-almn.
From the quantity of chromic oxide in the sulphate dried at 300° C. he found Cr » 26*66;
fW>m that which remained alter heating ammonio-chrome-alum to bright redness,
Cr = 26*78.

Lefort^ in 1860 (J. Fharm. [3] xviii 27), determined the quantity of baryta in
chromate of barium, by dissolving the salt in nitric add and precipitating hj snlphoric
add. In fourteen experiments, he fotmd that 100 pts. chromate of buinm yielded
60*36 to 60*01 baryta; mean 60*19: whence, if Ba^ 68*66, Cr^ 26*64.

Lastly, Wildenstein, in 1863 (J. pr. Chem. lix. 27)» determined the quantity of
chromate of barium predpitated from chloride of barium by neutral duomate of
potassium. Aa a mean of 32 experiments, he found that 100 pts. chromate of barium
correspond to 81*70 of the chloride ; the lunita were 81*62 and 81*86. If then Bas
68*66 and Q- 36*46, the value of Cr is 26*76.

As the predpitation of baryta by sulphuric add is affected by an error arising frmn
the canying down of a portion of the dissolved salt with the precipitated solphate, and
as moreover the atomic weight of bariun is not xery exactly Imown, it is probable
that the determinations of the atomic weight of chromium by Berlin and by Pfligot^
are the most exact, and the number 26*24 may be conddered very near to the tma
value. (Handw. d. Chem. 2** Aufl. ii [1] 482.)

CBBOMZinc, r&VOSIBBS or» The seaquifluoride, Ci<F", is obtained
by treating the sesquioxide, dried, but not ignited, with excess of hydrofluoric add,
and heating the dned mass yery strongly in a platinum cradble. It is dark gimi,
melts at a high temperattire, and is but very slightly volatile, even at the mdting
point of steel. When subjected to the highest temperature produced by a lamp aiged

* The ftreuctb of a solution of dichloride of tin li moet euily aicertslned bj means of a tUndanl
solution of pure acid chronutte of potassium.

CHROMIUM: lODmES— OXIDES. 947

by bellowB, it siiblimes in shining regular octahedrons (Deyille, Ann. Ch. Pharm.
cL 197). Beizelius obtained it as a green crystalline saline mass.

Chromic fluoride unites with the fluorides of ammonium, potassium, and sodium,
forming green sparingly soluble compounds.

Trifiuoride, CrlP. — This compound, discovered by Unverdorben, is obtained by
diBtilling 1 pt. of chromate of lead with 1 pt fluor spar and 8 pts. fuming oil of
vitriol in a leaden retort, and collecting the vapours in a perfectly d^ leaden receiver
kept at a very low temperature: it then condenses to a blood-red, strongly fuming liquid,
which becomes gaseous again at a temperature very little higher. The vapour is red,
and when inhaled, produces violent coughine and severe oppression of the lungs. It
is decomposed by water, forming hydrofluoric and chromic acids, and when it mixes
with the air, forms a thick white fume, coloured orange-yellow on the edges by minute
particles of chromic add. With ammonia it unites, according to Unverdorben, forming
a yellow volatile body ; but, according to Berzelius, it is decomposed with slight ex-
plosion, producing mtrogen gas, water, and hydrofluoric acid. Metals and other
reducing agents, oi]g;anic as wdl as inorganic, abstract part of the fluorine, leaving the
sesquifluoride. Sihcic acid decomposes it immediately, forming fluoride of silicium
and chromic acid ; hence it corrodes glass ; it may be kept» however, for a while in
glass vessels coated with resin.

H. Bose (Pogg. Ann. xxvii 565^ supposed that the formula of this compound was
CrF", because it contains more fluorine umn the formula CrF* requires, and its decom-
position by water is attended with evolution of oxygen, as well as the formation of
chromic and hydrofluoric acids. Berzelius, on the contrary, was of opinion that the
excess of fluorine above 3 atoms arose from admixture of hydrofluoric add, and that the
evolution of oxygen in its decomposition by water, was due to the previous mixture of
that gas with the vapour of the fluoride, inasmuch as the residue obtained in the pre-
paration of the compound always contains chromic oxide.

A fluoride of intermediate composition between the sesqui- and tri-fluorides is ob-
tained in solution by dissolving brown oxide of chromium in hydrofluoric add. The
solution is red, and yields by evaporation a rose-coloured salt, which is redissolved
without alteration by water, and predpitated brown by ammonia.

CHSOMZmc. Z09ZBB8 OV, ThesiMfui^oditU, Ci^\ is obtained in solution
by dissolving chromic hydrate in ^driodic acid, or by treating chxomate of silver with
hydriodic add and alcohol. It is green, and yields by evaporation a green glawy
residue, which splits into small pieces on eooUng. It is insoluble in eold, easil^
soluble in warm water, but does not separate oat again on cooling. No other iodide of
chromium is known with certainty.

OBlftOmmCv VZTRZDB or. GHN*? This compound is produced when
sesquichloride of chromium is heated in a stream of ammonia-gas: probably thus :

SCrKJl* + 18NH« - 20r^« + 9NH«C1 + H";

also when chlorochromie anhydride is treated in a similar manner. It is a brown
powder, which, when heated to 150^ — 200^ C. in a stream of oxygen, takes flre and
pums with a red light, giving off nitrogen gas and a small quantity of pemitric oxide,
and leaving sesquichloride of chromium. (Liebig^ ^^SB* Ann. xxL 869. — Schro tter,
Ann. Ch. Pharm. xxxviL 148. — Gm. iv. 139.)

CHBOBnVMt OSZnafl O V« Chromium forms several compounds with oxygen,
namely, the protoxide, Cr^, the seaqmo^nde, Cr*0', the trioxidey or chromie anhydride,
Cr'O' ; also an oxide, 0*0^ intermediate between Cx^ and CrH)*, and several oxides
intermediate between CrK)* and Ct'O*.

Pbotozidb of Ckboxiux. Chboxous Oxidb, CrK). (Moberg, J.pr.Chem.
xliv. 322. — ^P^ligot^ Ann. Ph. Phys. [3] xii. 628.)-— This oxide p^bably exists in some
specimens of chrome-iron ore (p. 989) and in pyrope. It is predpitated as a hydrate
by the action of potash on a solution of the protocnloride. The anhydrous protoxide
has not been obtained. The hydrate, 2Cx'0.H'0, is very unstable, decomposes water
even at ordinary temperatures, and unless carefully protected flrom the air, by pred-
pitating with a well-boiled solution of potash, is converted, as soon as it is formed, into
chromoso-chromie oxide, with evolution of hydrogen. It must be dried in an atmo-
sphere of hydrogen. It is yellow when recently predpitated, brown when dry, and
may be preserved unaltered in dzy air. "When ignited, it gives off hydrogen and leaves
sesquioxide: 2CrK).HK> - Cr*0" + H".

Chromous hydrate is insoluble in dilate adds, but dissolves slowly in strong adds«
The chromous salts are most easily prepared by mixing a solution of the proto-
chloride with the potasnum or sodium-salt of the corresponding acid^ They are
generally of a red colour, sometimes indining to blue, dissolve but sparingly in cold
water, more readily in hot water. Like fenous salts, they dissolve Lu^ quantities of

8p 3

948 CHROMIUM: OXIDES.

nitric oxide, forming daiic brown Bolationfl. (For their other reactions, see Fboto-

CHLOBIDS OF CHSOMinM, p. 942.)

CEB01CO8O-0HB01CI0 oxiDB, Ci*0*, or Ci^.CtK)'. — ^Formed when protochlonde i

of chromium is precipitated hy potash witiiont the precaations aboTe m^itianed far
excluding the air. After washing in water and drying in the air, it hajB the colour of
Spanish tobacco. It is but alightiij attacked by adds.

Sbsqitioxidb of Chbomiux. Ghboxic Oxidb, Cr^'. — ^This oxide existB in
chrome-izon ore (p. 939). and in chrome-ochre. The Utter occurs as a yellowish-greeii,
earthy or argillaceous deposit generally mixed with day, in the Shetland Isles; at Czeuzot
in France, at Halle and Waldenbmg in Silesia, at Martenbezg in Sweden, &e. (Dana,
ii 339). It is produced by heating chromium to redness in Sie air, by the ignition of
chromic hydrate, by the decomposition of chromic anhydride and of yarious cbromatie,
some of these processes yielding it in the amorphous, others in the crystalline slate.

a. Amarphoiis, 1. When mercurous diromate is heated as long as oxygen and
vapour of mercury are eyolyed, chromic oxide remains of a very fine green colour.
It IS best to heat uie salt in a covered crucible, since, if the air has free access to it, port
of the sesquioxide is converted into brown oxide, which impairs its colour. (Otto.)
— 2. When acid chromate of potassium is heated to redness with snlphur, tiie duomie
add is reduced, sulphurous anhydride is eyolyed, and there remams a mixtoze of
chromic oxide with sulphide and sulphate of potassium, from which the soluble salts
may be extracted by water. (Lassaigne, Ann. Ch. Phys. [3] xiy. 299.) — 3. Bertfaier
ignites chromate or potassium in a charcoal crudble, or mixes it with diarooal powder
or lampblack, and i^ites it in an ordinary eaithen crucible ; dissolves the chromite of
potassium produced in cold water; heats the filtrate to the boiling point ; collects the
predpitatea hydrate on a filter ; washes it thoroughly with water ; and lastly ignites it.
— 4. Wohler (Pogg. Ann. x. 46) ignites a mixture of acid diromate of potassium with
about its own wei^K of sal-ammoniac and a small quantity of carbonate of sodium
in a covered crudble, till no more vapour of sal-ammoniac is disengaged ; and tiieu
purifies the sesquioxide of chromium from chlorides of potassium and sodium, by
washing with water. — 5. Parian (Bev. sdent^ xx. 425) mixes 4 pts. of add chromate
of potassium with 1 pt of starch ; ignites the mixture in a crudble ; washes away
the resulting carbonate of potassium with water ; and again ignites the residue. He
states that the chromic oxide thus obtained is so pwe that it may be used for glaxii^
porcelain.— 4. When add chromate of ammonium is heated in a platinum or porce-
udn basin over a lamp, a very energetic action takes place, accompanied by stzong
incandescence, and green bulky masses of chromic oxide shoot out in every direction,
very much resembling unopened tea-leaves. (Bottger, Ann. Gh. Pharm. xlvii. 332.)
— 7. A very fine and intimate mixture is made of 4^ pts. of gunpowder, 240 pts. d
perfect^ dry add chromate of potsssium, and 6 pts. of equally dry chloride of ammo-
nium. This mixture is made into the shape of a cone (by pressing it into a wine
glass, and afterwards carefully shaking it out) and then transferred to an iron plate.
A burning fusee or other combustible is then applied to the top of the cone, nmere-
upon it takes fire, and slowly bums throughout its whole mass. On exhausting the
cone, while still hot, with water, a residue of chromic oxide is obtained in the form of a
pale green powder. (Bottgei^ he. cit)

b. CfrystaUised. 1. When vapour of chloro-chiomic anhydride is slowly passed
through a plass tube heated to low redness, chlorine and oxygen are evolved, and
chromic oxide remains in the tube as a crystalline deposit, sometimes interspersed with
laiger crystals (Wohler, Ann. Ch. Phazm. Ix. 208).— 2. When add chromate of
potassium is heated to whiteness for eighteen hours, a mixture of the neutral chro-
mate and chromic oxide is obtained; and on dissolying out the former with water,
chromic oxide remains in fine iridescent spangles (Q^ntele^ J. p. Chem. Hv. 184). —
3. When dry chlorine is passed over chromate of potasdum heated to redness in a
porcelain tube, the gas is completely absorbed, oxy^n is evolved, and chloride of potas-
sium is formed, together with chromic oxide, in long, shining, green, brittle tablets, if
the tube is heated only to a^ dull redness, but in hard brown crystals like those ob-
tained by Wohler^s method, if the temperature is raised to bright redness (Fr^my, Ann.
Ch. Pharm. xlix. 274). Blake (ibid, di. 331) found chromic oxide aprstallised in
plates having the metallic lustre and belonging to the hexagonal system, in the czadca
of a ftunace which had been used for a long time for the preparation of chromate of
potassium from chrome-iron ore.

Crystallised chromic oxide prepared by Wohler's method forms crystals of rhombo-
hedral diaracter, greenish-black with metallic lustre, and as hard as corundum, so
that they scratchy glass. Their specific grayity is 6*21, and they yidd a greenish
powder by trituration.

Amorphous chitmiic oxide obtained by decomposing the hydrate at a temperature
below redness, has a dark green colour; that which has been strongly ignited (methods

CHROMIUM: OXIDES. 949

1 to 7 p. 948) 18 bright green. When the oxide prepared at a moderate heat is gradu-
ally raued to a higheir temj)eratare, it suddenly becomes incandescent and is after-
wards nearly insoluble in adds. According to Senelius, it then contains the indif-
ferent modification of chromium (p. 941). By ignition with nitrate or acid sulphate
of potassium, it may be brought back to the solulue state.

Amorphous diromic oxide melts at the heat of a forge-fire, and on. cooling forms
a greenish-black crystalline mass, exhibiting all the properties of the crystalline oxide
obtained by Wohler^s method. It is not reduced by hydrogen ^;as. Charcoal reduces
it at an intense white heat» but only at the points where it is in contact with the
charcoal.

Chromic oxide is used in the preparation of green glass and enamel, but especially
in the painting of porcdain. It is also used in ordinary painting, forming one of the
most permanent greens, called chrome-green.

Hydraied Chromic Oxide, Chromic Sydraies, — Chromic oxide forms
seTeral hydrates differing in their properties. When a solution of a ^reen or violet
chromic salt is mixed with potash or soda, a bluish-green hydrate is precipitated,
which dissolres with emerald-green colour in excess of the precipitant^ but is repre-
cipitated completely as green hydrate on boiling. With ammonia, the violet salts give
a grey-blue, the green salts a grey-green precipitate. Both these precipitates dissolve
in cold acids, the former with re^ the latter with green colour. In excess of am-
monia, they both dissolve slowly with peach-blossom colour, the greyish-blue pre-
cipitate, however, the more abundantly of the two.

The properties of the hydrates, precipitated by ammonia, are affected to a eon-
siderable extent by the concentration and temperature of the chromic solution and
of the ammonia, by the way in which they are mixed, &e. ; and the results obtained
by different experimenters regarding the constitution and properties of these hydrates
are by no means accordant L. Schaffner (Ann. Ch. Pharm. IL 168) describ^ three
modifications of chromic hydrate : the first obtained by boilinff chromic chloride with
excess of potash, and containing, according to Or d way (SilL Am. J. [2] xxvi. 197),
Cr*0'.4H^, or H"Cr^O'; the second, by treating the chloride with sufficient potash to
redissolve the precipitate first formed, and neutralising the excess of alkali wiu hydro-
chloric add ; tiie third, by predpitating a solntion of a diromie salt with excess of
ammonia : the dried predpitate thus obtained is, according to Schaffiier, Cr*0'.6HK),
or H'«Cr<0».

The following results have been obtained by Lefort (J. Fhaim. fS] xviiL 27).
When a chromic salt is treated with excess of caustic soda-solution, tne predpitate
first formed redissolves with ^;reen colour if the original chromic salt was green or
red, with bluish-violet colour if the chromic salt was bluish-violet The solutions, if
heated, depodt a gelatinous hydrate of fine green colour, containing Cr*0'.dHK), or
HH>H)^ It becomes hard and black when dry, and yields a danc sreen powder.
The same hydrate is obtained by pouring a chromic salt of either modification into
excess of the boiling slkali-solntion.

Another green hydrate, Cr'O'.fiH'O, or H'^CrK)*, is deposited when the solution of
chromic oxide in excess of alkali is left to itsel£ It exhibits the same properties as
the preceding (Lefort). According to Fr^my, these hydrates contain 8 and 9 aq. re-
spectively.

A hydrate containing Cr*0'.7H'0, or H'Cr'O*, is obtained when a solution of violet
chrome-alum is poured into excess of ammonia ; the predpitated oxide then turns red
and redissolves, and, on heating the ammoniacal solution to a temperature not exceed-
ing 60^ C, a greyifl^-green pulverulent predpitate is formed, having the compodtion
just stated, and dissolving in adds with violet colour. (Lefort)

d, Cr*0*.9HK>, or H*CrH)*.— This hydrate is deposited as a violet powder when the
aramoniacal-solution of chrome-alum is left to evaporate in the air or over oil of vitrioL
When diy, it forms a greyish-violet^ very light powder ; when dissolved in adds, it yields
red salts. (Lefort)

According to Er^my, this hydrate is obtained by predpitating a violet chromic salt
with ammonia, and drying the predpitate in vacuo. It dissolves in acetic add, am-
monia, and dilute potash-ky. Its properties are liable to condderabla alteration from
apparenUy trifling circumstances ; thus, by the action of boiling water, or by proloneed
contact with cold water, b;^ the action of concentrated saline solutions^ by dedocation
for several days in the air or in vacuo, and trituration, it is rendered insoluble in
liquids in whidi it was previously soluble. Er^my^ is of opinion that these alterations
result from an allotropic modification of the chromic oxide, and not from loss of water.
He applies the term cnromic oxide to the oxide which has been rendered insoluble
in acetic add, potash, and ammonia in the manner just mentioned, and metachromio
oxide to that oxide which is soluble in these reagents^ and is predpitated by am-
monia from a violet chromic salt

3p 3

950 CHROMIUM: OXIDES.

A chromic hjdrate, much used as a pigment, is the emerald-green of Pannetia;
Gr*C)'.2HH^ •■ H^Cr*0\ It is prepared by melting in a crupible a mixture of eqmT»-
lent quantities of boric anhydride and acid chromate of potassium, whereby f^roniir
borate and borate of potassium are obtained, and treating the fused mass with water,
which resolyes the chromic borate into boric acid and chromic hydrate. By VBohixig
this hydrate and finely triturating it» a brilliant green powder is obtained. (G-nigne t,
lUp. Ghim. app. 1859, p. 168.)

Am an don {ibid. 201), by acting on acid chromate of potassium with phosphate of
ammonium, likewise obtained a rery fine green pigment, which appeared to be chieflj
a chromic hydrate containing phosphoric acid.

For further detaOs respecting the modifications of chromic hydratei, see Handw. d.
Chem. 2'* Aufl. ii [2] 1221.

Chromic Salts. — The salts obtained by dissolying chromic oxide or faydrsteiB
acids, correspond in composition to the oxide itself, containing, that is to say, 3 at.
of monatomic acid radicle to 2 at of chromium, or 3 at. of a diatomic aeid radios to
4 at. chromium, e. a. the nitrate Ci^(NO*)*, the sulphate Cr*(SO*)P. The most d^biit«
are the double sulpnates, called chrome-alums, consisting of 1 at. chromic soli^te with
1 at. sulphate of an alkali-metal and 12 at water, oorre8pondin|; in oonipoeition to
common alum, and crystallising in the same form, e,g. potassio-chromic sulphate,

K«SO^Cr«(SO«)« + 12H«0, or KCr»(SO*)« + 6H«0 - ^c^-|o* + 6H?0.

Chromic salts exhibit two modifications, the green, and the red, or yiolet, whidi
pass easily one into the other. Thus, a solution of chrome-alum prepared in tiie eoM
has a violet colour, which changes to green on heating the solution, but reappears after
it has been left to itself for some time. In many chromic salts the nitrate, for example,
the change from green to yiolet takes place \ery quickly. The green solutiosis also
take a bluish tint ^en heated with nitric add. The yiolet i^pears to be the normal
modification, inasmuch as the others always pass into it after a while ; and it is only
the yiolet solutions that yield crystallisable salts, the green solutions, iriien eyapomtod,
leaying green amorphous masses.

Schrotter (Pogg. Ann, liii 13) supposes that the change from the yiolet to the
green modification by heat, is the result of a loss of chemically ocnnbined water, which
is gradually resumed when the green solution is left at rest. Otto (Lehrbuch, 3 Anfl.
ii. 93) remarks, in opposition to this view, that a red solution of chrome-alnm does
not turn green when mixed with strong sulphuric acid, proyided rise of temperature
be prevented.

Lowel (J. pr. Chem. xxxyiL 38) supposes that the dijQTerent coloured aofaitioiiB
contain different proportions of acid and base, the red solutions containing; normal
chromic salts, such as Cr*(SO^)', or Cr*0*.3S0', and the green solutions basie satts of
the form Cr'0'.2S0'. This view receives some support from an observatioD of
Kruger (Pogg. Ann. Izi 218), that when a green solution of chrome-alum, obtained
by boiling the salt with a very small quantity of water, is mixed with ahsohol, the
alcohol takes up a portion of the sulphuric add, while the separated syrupy liquid
contains the salt KH3.CrK)'.3SO'. This salt, when dissolved in water, does not retum
to the violet modification unless a quantity of sulphuric add be added to it sufiScient
to reproduce the normal salt K*0.Cr*0».4S0»

Fr^mj attributes the change of the violet salts into green by the boiling of their
solutions, to a conversion of metachromic bxide into ordinary chromic oxide ; this, how-
ever, can scarcely be caUed an explanation.

For the behaviour of chromic salts with reagents see pp. 943, 944.

Chr 0 mites. — Chromic oxide unites with protoxides, forming compounds of the fotm
M*O.Cr*0', or MCr'O^ which may be called chromites. The ^st Imown of these com-
pounds is chrome-iron ore, in which, however, part of the chromium is usually replaced
by aluminium and sometimes by iron. Lime, magnesia, and oxide of me, when they
exist in solution with chromium, are sometimes predpitated by alkalis, when, if the
chromium were not present, they would remain dissolved ; thus, a solution of chrome-
alum mixed with chloride of caldum yields with ammonia a green predpitate, eon^
sisting of 2Ca*0.Cr^0*. On the other hand, bases which would otherwise be pre-
dpitated are sometimes retained in solution through the medium of chromic oxide ; this
is often the case with manganous and ferric oxide. In presence of 80 per cent ferric
oxide, however, chromic oxide is completely predpitated. These drcumstanoes require
to be carefully borne in mind in analysis.

Compounds of Chromic Oxide with Ammonia. (Fr^my, Ann. Ch Phaim.
ex. 226.) — Chromic hydrate is slightiy soluble in ammonia, and, under certain circum-
stances, takes up the dements of ammonia, forming peculiar metallic bases, designated
by Fc&my as amido-chromium compounds.

Chromic hydrate which has been subjected to the action of boiling water does not

CHROMIUM : OXIDES. 951

act upon ammonia; bat metacluomic hydrate (p. 960), in contact "with ammonia,
aoquiree a violet colour, and forms the eompomid oontaimng 2NH'.Cr*0', which gives
off the whole of its ammonia when heated.

Ammoniacal salts do not act on metachromic hydrate by themselves ; but if am-
monia is likewise present, ^e hydrate dissolves, forming compounds of a beautiful
violet colour, which may be obtained in definite form by precipitating with alcohol and
rapid drying in vacuo. The compound formed with ammonia and doloride of ammo-
nium diss^es in water with deep violet-red colour. The solution has a scarcely
perceptible alkaline reaction, and does not yield any precipitate with nitrate of silver;
but if it be heated to the boiling point, ammonia is ^ven off, chromic hvdrate sepa-
rates out, and the remaining liquid then gives a copious precipitate wim nitrate of
silver. The products of the decomposition are 4NHK)1, 8KH*, 8(V0", and H*0.

If Uie solution of tiie amido-chromium compound be left to itself for a while, it decom-
poses, ammonia being evolved, sal-ammoniac being reproduced, and an insoluble violet
body being formed, which separates in round, transparent, iridescent granules. This
body likewise contains the elements of ehromio oxide and ammonia, ft is completely
decomposed by boiling water, the products of decomposition being in the ratio of
Cr*0" : 2NH* : 12H«0. Acids convert it into a basic compound, CV0*.8NH*, called
roseo-chromammonia. With sulphuric acid the reaction is :

4(Cr«0«2NH») + 12H«S0* - (Cr«0«8NH«).8SO« + 3(Cr*0«.3SO^ + 12H«0.

Sulphate of roMo- Chromic

chronMmmomia. lulphate.

Boseo-chromammonia may likewise be obtained hy the action of strong acids in the
cold on the soluble amido-diromium compounds precipitated by alcohol from the zose-
ooloured liquids which are produced by the joint action of ammonia and ammonium-salts
on metachromic hydrate. The salts of this base have neady a wine-red colour ; the
hydrochlorate crystallises in regular octahedrons, and forms crystaUisable double salts
with mercuric and platinie chlorides. Pure water decomposes it into two new salts,
one crystallising in right rhombic prisms, the other remaining in solution. The bases
of these two salta appear to differ from each other, and likewise from that of the hydro-
chlorate from which they were produced. (Fr^mv.)

A basic compound containing Cr'(CNS)'.(NH*)'0 is obtained, by adding add chro-
mate of potassium to fiised sulphoqranate of ammonium. (M o r 1 a n d, Chem. Soc. Qn.
J. xiii 252.) (See SuiPHOOTAHAns.)

Bbowk Ozidbs of Chboxitjic Chboxatbs of Chbomivx. — ^These names
are applied to certain oxides intermediate between the sesqui- and tri-oxides of chro-
mium. They are obtained by gently heating chromic nitrate ; by partial reduction of
chromic anhydride with alcohol, solphurous acid, nitric oxide, or ferrous sulphate ;
also by boiling a solution of chromate of ammonium ; by digesting chromic acid with
excess of chromic oxide ; by heating chromic anhydride above 260° 0. ; and by keeping
chromic oxide for some time, at 200° C, in contact with the air. A solution of acid
chromate of potassium, mixed with ammonia or with alcohol, likewise deposits a brown
sediment when exposed to sunlight, but not in the dark.

These brown compounds, when heated, first give off water, if they are hydrated, and
at higher temperatures are reduced to chromic oxide ; they dissolve in acids, forming
brown solutions, from which thev are predpitated by ammonia without iJteration.
They give off chlorine when heated with hydrochloric add. Alkalis separate ehromio
acid from them.

The brown oxides, obtained by different processes, exhibit considerable diversity of
composition, and it is not exactly known whether they are distinct oxides of duromium
or compounds of the sesqui- and tri-oxides. The compound obtained by heating
chromic hydrate in contact with the air, which has the composition CrO, or CrH)'.Cr*0^
is regarded bv Kriiger as a peroxide of chromium, GrO, because, when heated with
sulphuric acid and chloride of sodium, it ^ves off only chlorine and no chlorochromio
anhydride, as all chromatcs do. A predpitate of the same compontion is formed, ac-
cording to Berzelius, on mixing neutral solutions of chromic chloride and chromate of po-
tassium. The predpitate thrown down by ammonia from a solution of chromic sulphate
mixed with acid chromate of potassiusi, likewise gives off nothing but chlorine when
similarly treated ; according to Vogd, it is 2CrO.H'0. The blade substance obtained

r* ^ eating chromic anhydride to 200° C. is, aocordin|p to Traube, normal chromate of
mium, Cr*0'.3CrK)*. It becomes soluble by boiling in water, imparting to the
water, first a yellowish, then a deep brown colour.

The precipitate formed on mixing the solutions of chrome-alum and neutral chromate
of potassium has, when dried at 100° C, the composition 3Cr*0'.2GrK>*.9H*0. The
oxide obtained by reducing chromic anhydride witn alcohol, has, according to Traube,
the same composition. It is insoluble in water ; dissolves in hydrochloric add with

3f 4

952 CHROMIUM: OXIDES.

yellow, in nitric and in hot diluie snlphnzic acid with brown coloor. The
yield with ammonia a precipitate of sesqnioxide, while chromic acid renuuna in solu-
tion. Potash quickly resolves it into chromic oxide^ and chromic acid.

Chromib hydrate digested with excess of chromic acid, yields a dark brown
which dries up to a residue soluble in alcohol, and containing, afoonling to
Cr«0».4CrK)«, or Cr«0». (Handw. d. Chem. 2*« Aufl. ii. [2] 1236.)»

Tbioxidb of Ghboxiuic Chboxio Anhtdbidb. Ankydrous CJkromic
Add, Cr'O*. — This oxide may be regarded as a constituent of the ehxomatea, tiie
formula of a neutral chzomate being HuM)*, or MK).CrH)'. It is obtained in the free
state:

a. By deeompoting trifluoride of chromium mth a »maU quantity of waier^'^The
vapour of the trifluoride, evolved by distilling ehromate of lead and fluor spur with
fuming sulphuric acid, is passed into a large platinum crueihle, slightly moistened on
the inside and closed with moist paper. The trifluoride is then decomposed by the
aqueous vapour, with which the air in the crucible is charged, into hydroflnone acid
and beautiful red needles of chromic anhvdride, which fill the crucible.

b. By decompoaifw a ehromate toith swphitrio acid. — Chromic acid is easilT' primed
by pouring 1 vol. of a saturated solution of acid ehromate of potassium in a thin Btream
into 1^ voL strong sulphuric add, stirring all the while. As the liquid cools, chzomie
anhydride crystaUises from it in splen<Hd crimson needles often an inch long. The
mother-liquor is decanted, and the crystals are drained on a porous tile till they are
nearly dry, and then purified by recrystallisation. For many pur^poses for which ehiomie
acid IS used, the presence of a certain quantity of sulphuric acid is not objectionable^
so that the purification may be dispensed with.

Bolley (Ann. Ch. Pharm. Ivi. 113) prepares chromic anhydride by dissolving a
weighed quantitv of acid ehromate of potassium in a small quanti^ of boiling water,
and adding to the hot solution the exact quantity of sulphuric acid required to fom
add sulphate of potassium. The mixtore when left to cool, solidifies for the nioet
part into a red granular mass consisting of add sulphate of potassium with adhenpg
chromic anhydride. The mixture is stirred to cause the granular mass to subside ; the
solution is decanted; and the residual add sulphate is washed several times with cold
water. There then remains an orange-coloured sulphate of potassium with very little
chromic acid, the greater part of USat acid being contained in the united solutions.
The separation thus effected depends upon the circumstance that add sulphate of po-
tassium, which dissolves verv freely in boiling water (2 pts. of the salt to 1 pt. of
water), is but sparingly soluble at ordinary temperatures, and cold water removes sul-
phuric acid from it with scarcely any potash, leaving neutral sulphate of potaasiam,
while the chromic add dissolves in llie cold water. The solution of chromic add con-
taining only a small quantity of add sulphate of potassium is then fkrther concen-
trated, and the chromic anhydride is predpitated by adding about an equal volume of
strong sulphuric add, which throws it down free from any trace of add sulphate.

Chromic anhydride may also be prepared by decomposing ehromate of lead with
strong sulphuric acid, diluting with water after twenty-four hours, to predpitate sul-
phate of lead, then filtering and evaporating to the crystallising point, or by decompos-
ing ehromate of barium with strong nitric acid, filtering the liquid fit»m the resulting
nitrate of barium, which is insoluble in the strong add, and heating the filtrate till
the excess of nitric add is enpelled, and crystallising as above.

Pure diromic anhydride forms either a red powder, a red loose woolly mass, or
scarlet crystals. It deliquesces in damp air and dissolves in a small quantity of water,
forming a dark brown liquid having a sour astringent taste and ydlow or brownish
yellow on dilution. The solution contains chromic add, but when evaporated it yields
the anhydride : indeed chromic add is not known in the solid state.

Chromic anhydride melts at 190° C, and begins to decompose at 250^, giving off
oxygen and leaving a brown oxide or ehromate of chromium, which, when further
heated, is reduced to sesqnioxide. Chromic anhydride is a powerM oxidising agent,
being quickly reduced to sesqnioxide of chromium by mUphydric acid, sine, arsefwna
acid, tartaric add, ^ugar, alcohol, and various other organic bodies, especially when
heated. With sulphydrio acid it forms water and sets si3phur free : 2Cr*0* + 3H^ «
Cr*0* + SH'O + S" ; with hydrochloric acid it yields sesquichloride of chromium,
water, and free chlorine: Ci«0» + 6HC1 « Ci*Cl» + 3H«0 + CP. Stdphurcus acid
added to a solution of chromic acid or a ehromate throws down a brown diromate
of chromium, consisting of Cr'O'.Cr'O' or CrO. A few drops of anhydrous
alcohol poured upon chromic anhydride instantly reduce it to sesquioxide, the
alcohol sometimes taking fire. A similar reduction attended with mcandivcenoe

» From recent experimenU by Storer and Bllot (Proc. Amer. Acad. ▼. lOS), it apfiean tiMt tlMreii
but one definite oxide of chromium Intermediate between Cr*(fi and Cr<OS, tIs. CrO or Cr<0>.Ci«OS.
Tbe authon hare UkewUe obuined the analogous componnda Al«OS.CrK>>, Fe^O^.d^O^, Ma40>.Cf«0*.

CHROMIUM: OXYCHLORmES. 953

takes place when a small quantity of the anhydride is introduced into an atmosphere
of flioohol Yaponr, or of alcohol or ether rapour mixed with snlphido of carbon. ^ Dry
iwrntonia gas saddenly directed npon perfectly -dij chromic anhydride, renders it in-
candescent and conyerts it into chromic oxide, while nitrogen and aqueous yapour are
giyen oS. Aqueous chromic add hleadies yegctable colours.

Chromic acid in the firee state is sometimes used practically as an oxidisng agent,
but more frequently a mixture of sulphuric acid and chromate of potassium, which
yields it

When crystalliaed chromic anhydride is added to strong sulphuric add as lon^ as it
dissolyes, an ochre-yellow, pasty, yeiy hygroscopic substance is formed, containing,
according to Bolley (Ann. Gh. JPhaim. lyL 113), H^O\Cr>0*. When exposed to the
air, it quickly turns red from separation of chromic anhydride. Schrotter (Pogg.
Aim. lix. 616) obtained in like manner a yellow-hrown sediment, which he represents
approximately by the formula Gr'O'.SSO'.

Pbbohboxic Acid. HCr*0* or BPO.Cr*0'? — When peroxide of hydrogen dis-
solyed in water is mixed with a solution of chromic add, the liquid assumes a deep
indigo-blue colour, but often loses this colour yeiy rapidly, giring off oxygen at the
same time. The same blue colour is produced on adoing a mixture of aqueous pe^
oxide of hydr(^[en and sulphuric or hydrochloric add to add chromate of potassium ;
but in a yery short time oxygen is eyolyed, and chrome-alum is left in solution. For
each atom of add chromate of potassium, KH).2Cr'0', 4 at. of oxysen are eyolyed,
proyided an excess of peroxide of hydrogen be present. We may, tnerefore, suppose
that perchromic add, HCr'O*, is first farmed dj the union of HO with (V0\ and
afterwards resolyed into oxygen and chromic hydrate, 2HCrH)^ * H'O.CrK)' + O^
With ether, perchromic anhydride forms a more stable solution than with water. The
ethereal solution, which has a deep blue colour, may be obtained by treating peroxide
of barium with hydrochloric or nitric add, pouring ether on the liquid, gradualljr add-
ing a solution of add chromate of potassium, and agitating. Perchromic add is de-
composed by aqueous alkalis, with formation of a chromate and eyolution of oxygen ;
but ammoma and certain organic bases dissolyed in ether and added to the ethereal
solution of the add, form stable compounds, from which stronger adds separate the
blue acid. The most stable of tiiese compounds is the quinine-ralt, which is soluble in
alcohol, insoluble in ether, and may be dried without decomposition. (Barreswil,
Compt. rend. xyi. 1085.)

The recent inyestigations of As chof (Inatigural-IHssertaium Sber die TJthermangan*
saure und Ueberchromsaurej Berlii^ ^^^11 ^^^^^ strongly to confirm the formula (>*0'
for hypothetical perchromic anhydride. He also finds that when the deep blue ethereal
solution of perchromic add is shaken up witii such a quantity of yery dilute aqueous
potash, that the ethereal layer shall stdl exhibit a faint blue tint, the aqueous, per-
fectly neutral liquid below exhibits a peculiar deep bluiah-yiolet tint, which is tolerably
stable ; but if more potash be added, the colour changes to the light yc^ow of neutral
chromate of potasdum, while bubbles of oxygen are ^yen off. Hence it appears that
the blue colour belongs to the free add, the yiolet to its salts.

According to Storer (J. pr. Chem. IxxxL 44) the colouring power of perchromic
add is so great, that when a solution of 1 pt. add chromate of potasdum in 30,000 to
40,000 pts. water is shaken up with ether containing peroxide of hydrogen, the ether
acquires a perceptible blue tint; he therefore recommends this reaction as a yeiy deli-
cate test for chromic add. Schonbein (Und. Ixxix. 66) applies it as a test for per-
oxide of hydrogen.

cnatomOMCp OXTOB&OSXBSi OV« Four of these compounds are known,
three of which may be regarded as compounds of sesquioxideand sesquichloride of chro-
mium, and the fourth (uie so-called chlorochronUe acid), as a compound of the tri-
chloride and trioxide. They may also be regarded as deriyed fh>m the trichloride or
sesquichloride by the substitution of oxygen for part of the chlorine.

a. Compounds of SesqmcMoridB and Besquioxide of Chromium, — These compounds,
of which three haye been distinguished, are obtained hy eyaporating the green solu-
tion of the sesquichloride, and heating the reddue to different temperatures. By dry-
ing at 120O C. a reddish tumefied mass is left, containing 8Gr*Cl*.CrH)* -f 24H*0, or
Or*a*«0« + 24H«0.

By diying at 150^ C, with constant stirring, a greyish red deliquescent powder is ob-
tained, conristing of 4CrH31«.Cr*0» + 8HK) - 3Cr«Cl*0 + 8HK), or, according to PAligot,
2(CrOCl.HCl) + HK). If this compound be heated to redness, it becomes partially
insoluble in water, and the undissolyed portion consists of GrKH'.Cr^O', or Cr'OCl. It
is flpreyish-red by daylight, green by lam{>li^ht, like neutral chromic sulphate. By
prolonged ignition in contact with the air, it is completely conyerted into seequioxide.
(Moberg.)

054 CHROMIUM: OXYGEN-SALTS — SULPHIDE.

Filigot ( J. pr. Chem. zzzrii. 476) obtained the last mentioned onydiloride by
precipitating a green solution of chromic chloride with baiprta, eraporating the filtrate
to dxynesa, treating the reaidne with alcohol, and e^aporatrng in -racuo, as a green de-
liqnescent maaa containing 201*001 + 3H*0. The same oxychloride ia obtained bj
boiling the green solution of the chloride with chromic hydrate, or bj prolonged boil--
ittff of dilate hydrochloric acid with excess of chromic hydrate.

b. Chlorochromie Anhydride, Chlaroekromic Acid. CrOCl, or GrOl'.Oi'O'.—
This compound, discovered by Berzelias, is produced by distilling any auhydroua metallic
chloride with an anhydrous chromate and strong sulphuric acid; its fonnation aflfords
a useful test for the presence of chlorides (p. 908). To prepare it, 10 pts. of decr^-
tated chloride of sodium are iused with 16-0 pts. of neutnu cnromate of potassium, and
the fused mass, after being broken into lumps, is distilled in a tubulated retort with
30 pta. of strong sulphuric acid, or better with the ftuning add. A brisk action imme-
diately takes place, and the chlorochromie anhydride quickly distils oyer, without appli-
cation of heat ; it must be collected in a dry receiyer kept at a low temperature. The
distillate obtained by heating the mixture towards the end of the process, is likely to
be contaminated with chronuc and sulphuric acida (Wohler, Pogg. Ann. *<Tf"i 343).
Another and easy mode of preparation is to distil in a small retort a dxj mixture of
chromic anhydride and feme chloride. ^Geuther, Ann. Oh. Pharm. cvi. 239.)

Ohlorochromic anhydride is a mobile liquid of a splendid blood-red colour by trans-
mitted li^^t, nearly black by reflected light It has a density of 1 '7 1, and boils at 1 1 8^ 0.
When exposed to the air, it difiiises a yellowish-red yapour of specific grayity 5*48. It
attacks mercury rapidly, detonates with phosphonUf seta firo to nUphur, alcakol, oU of
tur^eniine, and other inflammable bodies, and decomposes stdphydrie add^ with emiasion
of hght. In arnmonia gas, it solidifies with brilliant incandescence, forming a daric brown
mass, which remains red-hot for some time. If moro ammonia gas be passed oyer the
ignited residue, it changes to a black powder, which, according to Schrotter, ia nitride
of chromium. When chlorochromie anhydride is distilled wiSi ventachloride o/pkoi-
phoruSf chlorine-gas is eyolyed, and a small quantity of sesquichloride of chromium is
lormed, but the greater part of the chlorochromie anhydride diatils without alteration,
It dissolves iodine and forms a solid brown mass with chlorine. When dropped into
toaterf it remains unaltered for a few seconds, but is afterwards decomposed, with vio-
lent ebullition, into chromic and hydrochloric adds.

Vapour of chlorochromie anhydnde passed through a glsss tube heated to low red-
ness IB decomposed, with formation of crystalline chromic oxide (p. 948).

The compound described at pase 938 as chromochloride of potassium, may be re-
garded as a compound of chlorocSiromic anhydride with neutnl chromate of potas-
sium, K0r0*.0r0CL

€JMtLOWKKUWtLf OXTOaw«8AliTS OV* See Ohbomotjs and Oksomio Ozmis
(pp. 947, 950) ; also the several Acms.

cnmOKTUlIf PBOSFBXDB OF* Or?. — ^Formed when chromic phosphate is
strongly ignited with charcoal, or when sesquichloride of chromium is heated u phos-
phorotted hydrogen gas. The product obtained by the first process is light srey, with
faint lustre, and loosely coherent. The phosphide prepared firom crystaUised diromie
chloride forms crystalline scales, like those of the chloride itself; it is black, dissolves
but slightly in nitric, nitromuriatic or hydrofluoric add, oxidises slowly when healed
in the air ; when it is heated with hydrate of potasdum, hydrogen is evolyed, and
chromate of potassium very slowly formed. (H. Bose, Pogg. Ann. xxxiv. 833.)

OKHOanVM, BinurKZBBB or. The protoeulpkide, Or^, is said to be ob-
tained, mixed with chromic oxide, by heating chromic sulphate in dry oxygen gas
(T r an b e). According to Moberg, protochloride of chromium gives a black predpitate
with sulphide of ammonium.

The eesauietUphide, Or^S*, is produced by passing vapour of sulphide of carbon over
the white-not seequioxide ; by passing dry sulphydno add gas over chromic anhydride,
oxide, or chloride, heated to bright redness ; by heating chromic hydrate with suk»hur
in vacuo ; or by melting chromic oxide with pentasulphide of potassium at a very high
temperature. It cannot be obtained by predpitation, the predpitate formed hy sd-
phide of ammonium in solutions of duromic salts, consisting, not <^ sulphide, but of
hydrate.

Sesquisulphide of chromium is dark grey or bladE, according to the mode of profiara-
tion, sometimes shining and crystalline, without metallic mpeazance, but aci^uiring an
iron-groy metallic lustre by pressuro or trituration. When heated in the otr, it bums to
sesquioxide. Heated in chlorine gas, it yidds chloride of sulphur and seequiddoride of
chromium (Berzelius). According to H. Rose, on the other hand, chhurine scarody
acts upon it, even at high temperatures. Heated with nitre^ it yields sulphate and
chromate of potassium. It appears to unite with the add sulphides, forming sulphur-
salts. (Gm. iv. 124.)

CHROMOTARTARIC ACID — CHRYSAMMIC ACID. 955

. A siilpbide containing Ci^S* is obtained by heating chromic sulphate in hjdrosen
gas. Snlphnioiis anhydride is then eTolyed and solphniic acid is foimed, together
with a blackish-bzown, extremely pyrophoric powder, which bums in the air to cmx>mie
oxide and sulphurous anhydride. (Kopp, Compt. rend. ziz. 1166.)

OBSOBtOTJLSTAXIO AC^ZD. When tartaric acid in powder is gradually
added to a warm aqueous solution of. acid chromate of potassium, as long as carbonic
acid is evolYed, a green solution is formed, which yields by eyaporation a yitreous
mass, Teiy soluble in water, precipitated by alcohol, and containing, according to
Malagnti, O^H«K(Cr*0)'0* + 7aq. The solution of this salt yields with acetate of
lead, a bluish-green precipitate, which, when decomposed by sulphuretted hydrogeu,
yields tartrate of chromium and hydrogen, or chromo-tartario acid, C*H'(Cr'0)'0*.
(Berlin, Gerhardfa TraiU, ii 81.)

CHXOMnnbB* Syn. with Chlorophyll.

OSXTZOBZVB. A product of the decomposition of chrysammic acid by sulphuric
acid. (See Chbtsajixic Acn>.)

OHOtTSAMXBa. C*H*(NO*)<NO » N.H*.CrB[(NO*)*0. — A compound formed
by boiling chrysammic acid with aqueous ammonia^ The acid dissolves ; the liquid
acquires a deep purple tint, and on coolins deposits chrysamide in needles, which are
reddish-brown by transmitted, and metaSic green by reflected light. Its solution,
treated with dilute acids, does not yield a precipitate of chrysammic add. With
chloride of barium- and ammonia, it forms a precipitate of chrysamidate of barium.

According to the formula C'H'(NO')'NO, which is that proposed by Gerhardt
{Traitij iy. 253), chrysamide, like amides in general, differs from chrysammate of
ammonium, CrH(NH*)(KO^)0', by 1 at HK). This formula requires 40 per cent G,
2*4 H, and 20*1 N, whereas the analysis of chrysamide by Schunck and Mulder, gives
87*6 -38-8 G, 1-86— 2*35 H, and 18*2— 19*9 N; but it is probable that the chrysamide
analysed was partly converted during the preparation into chrysamidic add by addi-
tion of water, or rather perhaps, that the conversion of the chrysammate of ammonium
into chrysamide was not quite complete.

CSSmTBAMZBIO AOIB. Ammonuhckryaammuf aeid. CrH*N*0* » NH*.
G'HVNO')K)'. — This add, which is isomeric with chiysammate of ammonium, is pro-
duced by addine dilute sulphuric or hydrochloric add to a boiling aqueous solution of
dirysamide, an^ ciTstallises on cooling in dark-coloured needles, which become olive-
green on drying. Its aqueous solution has a deep purple colour, from which it is partly
predpitated by adds without change of colour. It gives off ammonia when treated
with potash. It is not altered by dilute adds. Strong sulphuric and boiling nitric
add partly convert it into ch^sammio add, with formation of ammoniacal salSi.

The chrysamidates, G'H^MN'O", have the compodtion of double chrysammates
of ammonium and another base, C(NH^)MN'0' They resemble the chrysammates
in appearance, and in their property of detonating when heated ; but are distinguished
by giving off ammonia when treatra with caustic potash.

Shrysamidate qf potassium crystallises in smsjl needles, having a green metallic
lustre by reflected light The bturiumrsalt is a red crystalline predpitate.

CSBTSAKMIO AOKD. G'H<NK)« - G'H^NO*)*0*. (Schunck. Ann. Cb.
Fharm. -rrr^^. i; Ixv. 235. — Mulder, ihid, Izziii. 339; Izzii 285. — Laurent,
Gompt chim. 1850, p. 163.— Sobiquet, J. Pharm. fS] x 167, 241). — This add is
produced by the action of nitric add upon aloes ; probably, also by the action of nitric
add on aporetin. (De la Bue and Miiller, Ghem. Soc Qu. J. z. 298.)

Preparation from aloes, — 1 pt of aloes is macerated with 8 pts. of nitric add of
specific gravity 1*37 ; the mass is heated in a large basin till the first violent action
has subsided, afterwards in a retort till two-thirds of the nitric add have been expelled ;
3 or 4 pt& more nitric add and water are added to the reddual liquid as long as a
predpitate continues to form ; and thejpredpitate, which consists of small shining scales,
is washed with cold water till the liquid no longer acquires a ydlow, but a fiunt purple-
red colour. The resulting duysammic add, still containing aloeUc acid, is triturated
with aqueous carbonate of potasnum ; and the gelatinous mass, which is thereby
formed, with evolution of carbonic add, is washed with cold water till tiie whole of
the carbonate of potasdum is removed, then dissolved in boiling water, and the solu-
tion filtered ; as the liquid cools, the pure potasdum-salt separates in golden-yeUow
laminiB. These o^stals are dissolved in boiling water, decomposed by nitric add,
and the chrysammic add, which separates in the form of a yellow powder, is washed
with cold water till the nitric add is completely removed, and the water is coloured
no longer yellow but light purple-red. In treating the chrysammic acid with carbo-
nate of potasdum, an excess of the latter must be avoided as &r as posdble, because it
produces a decompodtion and reddening of the salt, perhaps from admixture of aloetic
add.

956 CHRYSAMMIC ACID.

Chzysammic acid is a yellow powder, often light yellow or greeniflh yellow, and eon-
DBtiDg of small shinlDg scalee. It is sparingly soluble in cold, more easily in boiliiig
water. The solution has a deep purple colour, tastes bitter, and reddens litmus. It
dissolyes easily in alcohol and etker ; also in nitric acid and in saline solutions.

The add detonates Tiolently when subjected to dry distillation, emittii:^ a bsg^t
but smoky flame, and diffusing an odour of bitter almonds, tog^Bther with nitzona
Tapours. Heated in chlorine ^aa, it giyes off hydrochloric acid. Boiled with emutie
potash, it forms a brown solution from which acids throw down a dark brown pxeeipi*
tate (Schunck's aloeretic acid ; Huldei^s chryBotic add), soluble in pure water; forming
soluble salts with the alkalis and earths, insoluble with lead and si^er. If the potash
is yezy strong, ammonia is likewise evolved. Ghiysammic acid is not attadked bj
fuming nitric acid (Schunck). WiUi strong sulphuric acid at the boiling beat, it
reacts yiolently, giving off copious red fumes containing carbonic anhydride, cscbooie
oxide, sulphurous anhydride, and nitrous anhydride. At the same time a dark
Tiolet-coloured substance is deposited (Mulder^s chryiodine\ soluble in potash and re-
precipitated by hydrochloric acid, as a g^tinous mass of the same colour. This pio-
duct appears to be only a mixture, for ammonia separates it into a soluble ana an
insoluble portion. Sulphide of potassium mixed with caustic potash, transfonns
chxysammic add into hydrochrysamide : a similar blue substance (Muldei's ehrymndin-
ammonium) is obtained by decomposing a warm ammoniacal solution of chryaammie
acid with sulphuretted hyorogen. Ammonia oonyerts chiysammic add into chiysamide.
The add boiled with water and stannous chloride, forms a powder which has a deep
-violet colour, is nearly insoluble in all solvents {C^*H*I^0^^,Z8n0^, according to
Mulder), gives off ammonia and assumes a fine blue colour when treated with potash,
and is decomposed by nitric acid, yielding aloetic and chiysammic adds.

The chrysammate9 mostly crystallise in small scales, and exhibit a gold-grem
metallic lustre on the ciystalline faces ; those which are amorphous, exhibit the same
lustre when rubbed with a hard body. They detonate violently when heated. They
are all sparingly soluble, even those of the alkali-metals. In solutions of aoctatea they
dissolve more easily than in water, but less when heated than in the cold.
Chrysammate of Ammonium changes rapidly into chiysamide.

Chrysammate of Barium, C'HBaNK)* + 2aq., is obtained as a Termilion-coloored
predpitate by mixing a solution of the potassium-salt with chloride of barium ; alao by
prolonged boiling of chiysammic add with chloride of barium. It is quite inaofaible
in water.

Chrysammate of Cadmium is a dark purple predpitate.

Chrysammate of Calcium is a dark red insoluble powder, exhibiting traces of OTSftal-
lisation.

Chrysammate of Copper, CHCuNK)* + xaq., is sparingly soluble in oold, more soluble
in boiling water, from which it separates in dark purple needles, exhibiting a golden
lustre by reflected light : its solution has a flue puxple tint.

Chrysammate of Lead, C'HPbN*0«? — Brick-red insoluble powder, obtained by
precipitation. According to Schunck, it gives by analysis 34*2 per cent^ PbK>, the
formula requiring 35*78. Mulder found in the predpitate formea with chiysammate
of potassium and neutral acetate of lead, 61*6 per cent. PbK), whidi ooireeponda to the
formuk C^HPbN«0«.PbHO.

Chrysammate of Magnesium resembles the caldum-salt.

Chrysammate €f Potassium, C^KKNK)* crystallises in flat rhomboi'dal plates, which
exhibit very remarkable relations to polarised light Light transmitted through one
of them, exhibits a reddish-vellow colour and becomes polarised in one jdaae ; bat
if the crystal be pressed with the blade of a knife on a plate of glass, it spreads on
the glass like an amalgam, and a beam of light, transmitted through the thin film
thus formed, splits into two rays polarised in planes perpendicular to eadi otiier, one
having a carmine-red, the other a pale yellow colour. As the thickness of the film
increases, the colour of both rays approaches more and more to carmine-red. Stifl
more remarkable phenomena are eidiibited by reflected light. An ordinaiy ray of
white light reflected perpendicularly from the &ce of a crystal or from a film, has the
colour of virgin-gold, but as the inddence becomes more oblique, the colour becomes
less and less yellow, and at length passes into pale blue. The beam thus reflected ia
composed of two rays oppositely polarised ; the one which is polarised in the plane of
reflection remains of a pale blue colour at all angles of inddence ; the other, polarised
at right angles to the plane of reflection, has a pale-yellow colour at small indinationsi,
then changes to deep yellow, greenish-yellow, green, bluish-green, blue and violet.
(BTew8ieT,Gerhardfs Traiii, iv. 261.)

Chiysammate of potaAsium dissolves in 1260 pts. of oold water, easily in boiling
water ; the solution has a flue red colour.
Chrysammate of Silver. Dark brown precipitate, quite insoluble in boiling water.

CHRYSANILIC ACID — CHRYSATRIC ACID. 957

Chrysammate of Sodium resembles the potassium-salt in appearance, and possesses
the same degree of solubility.

ChrysamrtuUe of Zinc crystallises in small dark red needles with gold-green reflection.

OBBTSAJnXiZO ACZB. This name was given by Fritzsche to a bluish-red
substance obtained by the action of potash upon indigo;, according to Gerhardt
however (TraiUy iii. 521), it is nothing but a mixture of isatin, white indigo, and
possibly other products. (See Inbioo.)

CB&TSAWZ8ZO AOZB. CrH»N*0' » 0'H*(N0')*O (Cahours, Ann. Ch. Phys.
[3] zxvii 454\ — ^This acidf which is isomeric with tnnitranisol, and may also be re-
garded as meinyl-picric acid, C*H*(CH")(NO*)"0, is produced, together with di- andtri-
nitranisol, by the action of warm fuming nitric acid on anisic acid (p. 300). When 1 pt.
of perfectly dry anisic acid is veiy gentiy boiled for half or three-quarters of an hour
with 2^ pts. of fuming nitric acid, and the somewhat thick liquid is mixed with 20 times
its bulk of water, a yellow oil separates out, which soon coagulates into a solid mass
consisting of chrysanisic add mixed with di- and tri-nitranisoL This mixture, in the
form of mie powder, is washed on a filter with ammonia diluted with two or tiiree
times its bulk of water, whereby the acid is extracted ; the ammoniacal liquid, after
being evaporated to one-third, yields on cooling brown needles of the ammonia-salt.
These crystals aro dissolved in water ; the solution mixed with dilute hydrochloric
acid ; the separated yellow flakes are collected on a filter, repeatedly washed with cold
water, dried between bibulous paper, and dissolved in hot alcohol ; and the scales
which crystallise from the solution on cooling are dried.

Chrysanisic add forms small golden-yellow rhombic tables, nearly insoluble in cold
water, sparingly soluble in hot water, whence it ciystaUises on cooling. It is but slightly
soluble m coM alcohol, but dissolves so abundantly in hot alcohol, that the hquid
solidifies on cooling. It dissolves in ether, especially if hot, and ciystallises in shining
laminae as the ether evi^porates. The add melts when cautiously heated, and solidifies
in the crystalline form on cooling; at a stronger heat, it emits a yellow vapour which
condenses in small ctystaUine s(»les having a strong lustre.

When boiled with strong nitric add, it is converted into picric add. Distilled with
aqueous chloride of lime, it yields chloropiczin. By boihng with potash, it is con-
verted into a brown substance.

Chrvsanisate of Arnrnonivm, — The solution of the add in dilute ammonia, evaporated
over the water-lMtth, yields on cooling, small brown needles having a strong lustre.
Finer crystals are obtained by spontaneous evaporation of the solution.

ChrysanisaieofPotasnum, G*S^K(NO')*0, is obtained by exactly saturating the add
with potash. It is very soluble.

The ammonium-salt produces in solutions of ^inc-salts, a pale yellow precipitate ; with
nitrate of cobalt^ a greenish yellow gelatinous predpitate ; with nitrate of leadf a
copious deposit of chrome-vellow flakes ; with/emc salts, a pale ydlow ; with cuprio
salts, a greenish yellow, gelatinous predpitate ; and with mercuHo chloride^ yeUowish-
red flakes, which in dilute solutions appear after a time only.

ChryMmwUof SUffer^ C«H*Ag(NO«)K>.— -The ammonium-salt forms with nitrate
of silver, beautiftd yellow flakes^ whidi must be washed with water and dried in
vacuo.

Chiysanisate of Ethyl, C'HXC<H^)(NO*)'0, is obtained by saturating the alcoholic
solution of the add with dry h;^drochloric add gas, gently lioiling for some time, and
then adding water. The resulting predpitate is washed, first wiui ammoniacal, after-
wards with pure water, then dissolved in boiling alcohol,' and the solution is left to cool.
It forms transparent crystalline laminie of a splendid golden-yellow colour, melting at
about 100^ C. It is soluble in warm ether.

CHHTBAVTSSMUM MWUlTUBi* The ash of this plant has been analysed
by Banger t (J. pr. Chem. Ixx. 86). — The fresh plant ^dded 1*61 per cent, the plant
dried at 100° C, 8'52 per cent ash (63*3 per cent of which was soluble in water). The
ash contained in 100 pts. : 24*86 £>0, 6*21 Na'O, 1408 Ca*0, 6*96 Hg«0, trace of
manganese, 6*12 S0«, 12*36 CO*, 6*16 P*0», 4*68 8iO», 1610 NaCl, with 3*06 sand and
charcoal.

OBmTSATBlO AOXB. (Mulder, J. pr. Chem. xlviii. 16.) Aloeretie acid,
(Schuncl^ Ann. Ch. Pharm. Iv. 240.) — An add produced by heating chiysammic
add with alkalis. Chiysammic add heated with potash-ley dissolves, forming a brown
solution, from which, according to Mulder, acetic add does not predpitate anything;
according to Schunck, however, a brown predpitate is obtained. The solution of the
potasdum-salt yields with acetate of lead, a brown precipitate containing; according
to Tonningen's analysis, 68*71 per cent FbK), 1908 C,-078 H, and 6*61 N. With
chloride of barium, a predpitate is fonned, containing 30*80 per cent Ba^, 28*03 C, and
1*82 H. (Schunck). These analyses do not lead to any satisfiictozy formuku

958 CHRYSENE — CHRYSOPH ANIC ACID.

i»<>H«. (Laurent^ Ann. CHl Phya. [2] Ixvi. 136.) — AaTstalllDe
hydrocarbon obtained, together with jiyren^, bj the dry diatillation of hta, lesms, and
coal: it may be extracted from ooal-tar by redutillation. The products which pass oy«r
towaidfl the end of the process, consist of a soft yellow or reddish mass, aiod a ihiek.
oil containing ciystalline scales. That which condenses in the nedk of the retoxt ia
chiefly chrysene, the pyrene passing for the most part into the receiyer. By tx«ating
the mass in the neck of the retort with ether, the pyrene and certain oily matteis axe
diBSolved out, while the chrysene remains in the pnlveralent state.

Pure chrysene has a fine yellow colour ; it is crystalline, destitute of taste and odom;
insoluble in water and alcohol, nearly insoluble in ether : oil of tnipe&tine diasolTies it
at the boiling heat^ and deposits it on cooling in yellow crystalline flakes. It meltB
at 230^ — 235^ C, and solidifies on cooling to a deep yellow mass composed of needles..
At a higher temperature, it distils with slight alteration.

URtroehr^tme^ nCH*(NO'), produced by the action of strong boiling nitric acid on
chrysene, is a red powder, destitute of taste and odour, insoluble in water, nearly
insoluble in alcohol and ether. It is dissolved with brown colour by sulphuric acid,
partially also by alcoholic potash. When quickly heated in a dosed tobe^ it melts
and decomposes with explosion.

cnftTBZVBZV. A product of the decomposition of chrysammic aeid by am-
monia. (Mulder, p. 956.)

CBSTSOBBBTlh CyTnaphane, Chrygopal. — An aluminate of gludnuzn, APGK>*,
or GP0.A1*0*, generally containing 2 or 3 per cent, of iron. It is usually found in itnmd
pieces about the sise of a pea, but sometimes in eight^ded prisms with sixHoded
summits, belonging to the trunetric system. Specific gravity 3*6 — 3-7. Hardneas 8*5.
Lustre vitreous. Colour various ^ades of green. Streak unooloured. Transparent or
translucent, sometimes with bluish opalescence internally. Fracture oonchoidal, uneren.
It exhibits double refraction, and becomes electric by friction. It is infbsiUe alone
before the blowpipe, and very difficult to fiise with borax or phosj^orus-flalk With
carbonate of sodium, the sui^ioe is merely rendered dulL It is not acted upon by acids.

Chiysobeiyl is found in Brazil and Ceylon, in rolled pebbles, in the alluvial deposit
of rivers ; and in mnite at Haddaw, Connecticut, Greenfield, near Saratoga New
York, and Orange Summit, Vermont. When transparent and of sufficient sisc^ it is
cut into feicets and forms a gem.

Crystals of chrysobezyl have been formed artificially by exposing a mixture of
alumina and glucina in the proper proportion, together with boracic acid as a flnx, to
the heat of a pottery furnace for several days, tifi the boracic acid is completely vola-
tilised (Ebelmen, Ann. Ch. Phys. [31 xxii. 211; xxxiii 34). {For the CTystalline
form of the artifidal chrysobor^l, see Jaliresber. d. Chem. 1851, p. 766.]

A variety of chrysobeiyl called Alexundriie, from the Ural, exhibits pleoehioisni,
viz. by perfectly white light, an orange-yellow colour in the direction of the longer
diagonal of the base, oolombo-red along the shorter diagonal, and emerald-green along
the principal axis. (Haidinger, Pogg. Ann. Ixxvii, 228.)

CB&nOGOXabA. The Greek name for borax. Applied also to silicate of copper.

iSBMTBOMAMMOMMm Syn. with NnsoHABMAZJini {q. v.)

CHXnOTUIMn C^^* ? — A yellow colouring matter said to exist in very small
quantity in asparagus-berries.

CBBTSOXAPXO ACZS. Syn. with Picnic Acm.

CKS.TBOXATB. PeridoU, Olivin. — A silicate of magnesium and iron, (Mg ;Fe)*
SiO*, occuixing in basalt and lavas, in prismatic crystals of the trimetrio system, also
massive and compact or granular; colour olive and other shades of green. The term
Chrysolite includes the transparent crystals of paler colour, while OUoine (ao^allod
from the olive-green tint) is applied to imbedded masses or grains of inferior ocdour
and clearness. (See Guvinb.)

Syn. with Plbonast.
Syn. with Chbtsobsbtl.
See Climtonitb.

CBMTBOWKJUno AOZXI. Ckrysophane, Rhubarbario add, Rkubarbarm, Eku-
harb-yeUow, Rhein, Rheic acid, Sheumin, Bh(wo9Uicin, JRutmdn, C'HK)', or C'H>*0*
The yellow colouriiu; principle of rhubarb and of the wall lichen (PamuUa parieiuut).
It was first obtained m an impure state by Herbeiger, Dulk, and Brandes, afterwanu
analysed by Bochleder and Heldt (Ami. Ch. Pharm. xlvui. 12), who extracted the
pure substance from the ParmeUa; also by Bopping and Schlossberger (tiML 1.
215X by Be La Bue and Miller (Chem. Soc. Qu. J. x. 298) and by Thann (Ann.
Ch. Pharm. cvii 324), who obtained it from rhubarb.
Preparation from Parmdia parietina. — The dried lichen is digested in the cold

CHBYSOPHANIC ACID. 959

with alcoholic potash or ammonia; the dark red infnnon is filtered and mixed with
acetic acid ; the bulky yellow flocks thereby precipitated are washed with water and
redifisolved in alcoholic potash, a certain qnantity of resin then remaining nndissolved ;
the liquid is again precipitated by hydro<uiloric acid ; and the precipitate, after wash-
ing and drying, is rediBsolred in a small qnantity of boiling absolute alcohoL The
s^ution thendepositB du^sophanio add in the crystallised state.

Fnyn i?Att&arS. ^Dnlk prepared chiysophanic acid from rhubarb by exhausting the
root with alcoholic ammonia, predpitating with subacetate of lead, and decomposing
the piedpitate, suspended in afcohoi, with sulphuretted hydrogen. Schlossberger and
Dopping ochaust uie pulyerised rhubarb with 80 per cent alcohol; eyaporate; redis-
soWe in a small quantity of alcohol ; add ether to the solution to preapitate certain
resinous matters ; evaporate the filtered solution to the crystallising point ; and purify
the chiysophanic add ^us obtained by repeated crystallisation from boiling absolute
alcohoL

Be la Bue and Muller find that chiysophanic add may be extracted from rhubarb
with much greater facility by means of benzene or the lisht hydrocarbons obtained
from Burmese naphtiia, these liquids dissolying it yery reamly, to the exdusion of the
greater part of the other oonstibients. The crushed root is first macerated in water,
whidi remoyes about (fO per cent, of soluble matter, then dried and treated with
benzene in a Mohr*s displacement apparatus ; the greater part of the benzene is then
distilled off; the residue, which becomes nearly solid on cooling, is pressed between
blotting paper to remove the mother-liquor which contains enrthroretui and a neutral
fat- ; the crude dirysophanie add thus obtained is redissolved in hot benzene, which
leaves behind a reddish-yellow substance {tfmi>dAn\ an additional quantity of which
separates as the solution cools ; and the chiysophanic acid, which afterwards ciystallisee
out, is farther purified by reciystallisation from acetic add, amylic alcohol, or common
alcohoL The residuary rhubarb, thrown away in pharmaceutical laboratories after the
preparation of the ordmaiy alcoholic tincture, may be advantageously used for the pre-
paration of chiysophanic add b^ this process, inasmuch as it contains about 2*6 per
cent of liiat acid, which is but sUghtly soluble in alcohol, espedally in the weak spirit
used in the premuration of the tincture. The dark coloured resinous sediment which
separates from Tmetura Sheiyrhen left to itself is also rich in chiysophanic add, and
may be subjected to the same treatment.

Thann extracts ttie root of Sumex obtuttfoliua with ether ; distils off the greater part
of the liquid ; washes the dark yellow-brown mass which separates on cooling with a
small quantity of ether ; dries it between bibulous paper ; boils the residue with 90
per cent, alcohol ; dissolves the dirty green granular mass which separates on cooling
with alcohol, and predpitates by water, repeating the solution and precipitation several
times ; purifies the proauct by treatment with alcoholic ammonia and acetic add, as in
Bodileder and Helat's process ; then aystallises it from alcohol, and lastly from etiier
by slow evaporation.

Chiysophanic add ciystallises from benzene in six-sided tables (monodinic), having
a pale yellow or orange-yellow colour ; from alcohol, amyl-alcohol, or glacial acetic
add, in moss-like aggregates of laminar crystals. It is sparmgly soluble in cold water;
dissolves in 224 pts. of filing alcohol of 86 per cent. ; in 1126 pts. of the same alcohol
at 30^ C. It is soluble also in ether and in oil of turpentine, coal-naphtha, benzene, and
other hydrocarbons (trid, stip.) It melts without decomposition at 162^ C and soli-
difies in the crystalline form on cooUng.

The formula of chiysophanic add is not quite settled. The analyses by Bochleder
and Heldt) and by Ischlossberger and Dopping, approach nearly to Uie formula
C'HH)', while those by De la Bue and MiUler, and by Thann, agree better with

CaltmlaUbn.

Rochleder

Schlocsben^er

DelaRuo

CaladaHom.

CMII"OS

and H«klt.

and Ddpplng.

and MOller.

Thann.

C»?H'0O«

Carbon .

. 6812

68*08

6812

68*76

69*62

69-62

Hydrogen

. 4*64

4-67

4*69

4*26

4-89

412

Oxygen.

. 27-84

»>

26*36

100*00 100*00

Chiysophanic add subjected to diy distiDation, partly sublimes, while another por-
tion becomes carbonised. Dilute nitric add does not appear to act upon it, even at
the boUing heat, but the stzong add converts it into a red substance. Stiong sulphuric
add dissolves without decomposing it, and water predpitates it from the solution.

The add dissolves in alkalis wim fine deep purple colour: the reaction is very deli-
cate, so that a dilute solution of chiysophanic acid may be used as a test for alkalis.
Its solution in potash may be evaporated to dryness without alteration ; but at a certain
degree of concentration, it deposits blue or violet flocks, which redissolve in water or
ali^ol, forming red solutions. If the purple solution of the acid in moderately strong

960 CHBYSOPEASE — CHYLE.

potash, together with the flocculent precipitate, be mixed with gnpe Bogar and left to
Btand in a dosed yessel, the alkali being in excess, the colour of the liquid gradnalfy
chanffes to brownish-yellow, and the precipitate disappears : on snbseqnent exposure to
the air, tiie original colour and the precipitate are reproduced. Hydnte of potaosinm
at its melting point does not act on ehzysophanie acid at first ; bnt if the heat be oon-
tinned or incrMsed, the liquid turns blue and decomposes, emitting an odour like that
of odylie alcohol. (De la I^ue and Muller.)

With bairta and oxide of lead, chrysophanie add forms yezy unstable oompooiids^
which are decomposed eren by the carbonic add in the air. Its alcoholic solution
forms with aloohoUc subaoetate of lead, a reddish-white predpitate^ wideb. changes to
rose-red by boiling with water ; no predpitate with neutral acetate of lead. The am-
moniacal solution of chrysophanie acid yields with neutral acetate of lead, a lilac ; with
alum, a beautifhl rose-coloured predpitate. (Thann.)

CMKTUOWtUkMM» An apple-green or leek-green varietj of chalcedony, coloured
by nidceL

OBKTSOmAn BASTB. See Pdceutb.

OBBTBOXSXXV. A yellow resin obtained from senna-leayes by evaporating
the aqueous extract, treating the reddue with alcohol, evi^rating, dissolying in ether,
and again evaporating. It is a mixture of several substances, perhaps containii^
chiysophanic add, or a similar add. (Bley and Diesel, Jahresbor. 1848, p. 823.)

OBXTBOBBABmar. A yellow aystalline substance contained in I>enaan
benries or ydlow berries {grainea ^Avtgnon^ KratUz-beeren% the fruit of Bkammu
amyffdalintu, R. oleMeSt B. saxatUiSf ^., espeisiaEy in the unripe state. According to
Kane (Ann. Ch. Fhys. [3] yiii 380), it may be extracted from the benies by ether, in
which it is easily soluble. It is nearly insoluble in cold water, soluble in alcohol, and
contains 58*02 per cent carbon, and 4*7 hydrogen, whence Kane deduces (he fomnila
CH'H)". By boilinff with alcohol or water, it is decomposed, yiddingp another
colouring matter, XantAorhamMHt C**H**0", which is soluble in water and alcohol, bat
insoluble in ether.

Gellatly (Edinb. K PhiL J. vu. 252), by treating Persian berries with ^iier, ob-
tained ndther chrysorhamnin nor any other eharacteristie substance ; but with alcohol,
he obtained a yellow substance ezystallising in needles, which appeared to be xantho-
rhamnin.

According to Boll ey (Chem. Soc. Qu. J. xiii 327), Persian berries yield an abun-
dant extract when treated with crttde ether (this may perhaps explain the difference
between the statements of Kane and Gellatly) ; and on evaporating the ether, dissolving
the residue in alcohol, filtering, and evaporating with addition of water, stellate gionps
of yellow needles are obtained, which are not altered by repeated solution, boiling,
and precipitation. They gave, by analysis of two specimens, 58*87 and 60*239 per cent
carbon, 4*66 and 4*18 hydrogen. The crystals were somewhat soluble in pure ether,
sparingly in water, easily in alcohoL The solution Rives with neutral acetate of
lead, a brick-red predpitate ; with nitrate of silver, a blood-red liquid, and afterwards
reduced silver. Hence^ and from the analysis, Bolley oondudes that this substance ia
quercetin (q, v,)

See SBBFBiniiis.

Uncrystallisable sugar. (See Suoab.)
See OuviNB.

OKTUL (Lehmann, GmelMs Hatidbueh, yiii. 216 ; Physiological Chentuiry, u.
281.— Pelouse and Fr^my, Traitij vi 162). — Chyle is that portion of the products of
digestion which is absorbed by the lacteal vessels terminating in the inner surface of
the small intestines, chiefly the jejunum, and thence passing by numerous converging
streams into the main trunk of the absorbent system, called the thoracic duct, through
which it is gradually poured into the blood of the left subdayian vein, at a short <^i»tJi«^»^»
before it enters the nght side of the heart.

The physical properties of chyle differ according to the nature of the animal to
which it belongs, the condition of the animal, wheUier latdv fed or fiisting, and the
nature of the food which has been taken. Chyle obtained from the thorade duet
during digestion, is an opalescent^ milky, yellowish-white or pale red liquid, having a
faint,^ peculiar odour, a somewhat saline and mawkish taste, and very weak alkaline
reaction; its specific gravity varies from 1*012 to 1*022. Kine or ten minutes after
removal from the vessels, it coagulates ; the coagulum, which contracts in from two to
four hours, is smaller in bulk compared with the serum than that of blood ; it is very soft,
easily torn, and sometimes gdatinous. If of a yeUow colour, it generally becomes some-
what reddish on exposure to the air, an effect especially observed In the chyle of
horses. The serum of chyle, after separation from the ooa^ilum, is never quite dear ;
it does not usually become turbid when mixed with water ; on boiling with water, a

CHYLE. 961

milky turbiditr appears in the liquid, which, howerer, generally deposits only a few
smaU clots. Acetic acid often produces a turbidity in the serum, and the filtered
liquid when erapomted exhibits on its surface, colourless, transparent films of albumi-
nate of sodium. Ether does not ooagalate chyle-serum, but renders it clearer, and
between the ether and the serum there is formed a cream-like staitum of a dirt^
yellowish-white colour.

The chyle of birds, amphibia, and fishes, is nearly transparent and colourless; in
horses, it is of a deeper red colour than in any other aninmls which have been
eumined with reference to this subject* That of camiyora is oomparatiyely thick and
milky ; that of herbivora, thinner and more transparent ; in cats, it is of a perfectly
milky whiteness^ whateyer may be the nature of their food. Burin^ digestion, the
chyle is for the most part yery turbid ; at other times it forms a famtly opalescent
fluid, exhibiting a red(ush colour only in the thoracic duct.

The morphological elements of the chyle, are : 1. Extremely small granules, consist-
ing of drops of fat enclosed in an albuminous enyelope. — 2. C^ranules bound together
by a hyahne substance, with or without nuclei, sna separate flranules with distinct
nucleus. — 3. The so-called chyle-cells, 0*002 to 0*0065 of a line in diameter, the granules
of which mostly become yiaible on addition of water or acetic add. — 4. The transition
forms of the seyeral structures from the more simple to the more complex. — 5. A small
quantity of coloured blood-cells, especially in the chyle of the thoracic duct

TheehenUcal constituents of chyle are yery nearly the same as those of the interoellnlar
fluid of the blood. It is difficult, howeyer, to obtain chyle of constant composition,
partly becanse it yaries with the quality and quantity of the fbod taken, partly because
it is always more or less mixed with lymph and blood.

The fibrin of ch^le is in general less contractile and more gelatinous than that of
blood ; like the flbnn of many pathological exudationa^ and that of fibdi, it sometimes
redissolyes after coagulation, especially if heated; it is usually destitute of the fibrous
structure of blood-fibrin ; dissolyes yeiy easily in dilute alkalis, carbonic acid, and
organic acids; also, after awhile, in solution of nitre, and eyen in sal-ammoniac; from
its solution in acetic add, it is completely predpitated by sal-ammoniac, and from its
solution in sal-ammoniac by acetic add.

The albumin of ohyle contains a larger amount of alkali than that of blood ; it is
not rendered turbid, eyen by yery great dilution with water ; when boiled, it forms,
not coherent flocks, but a milk-white opaque liquid ; on eyaporation, colourless films
form on the surface. The aqueous extract of the ch^le-residue has a strong alkaline
reaction ; on neutralising it with acetic add, a turbidity is produced, which uterwards
redissolyes ; on snbseqnentiy adding ferrocyanide of potassium, a copious predpitate is
formed.^ The original aqueous extract becomes strongly turbid by boiling with sal-
ammoniac, also on addition of nitric add. From chyle-albumin exhausted with water,
alcohol, and ether, Lehmann obtained 2*068 per cent of ash, containing a considerable
quantity of alkaline salt which efiTenresced with adds.

The fat of chyle is mostly unsaponified in the smaller lacteals, saponified in the
thoradc duct Chyle does not appear to contain any crystalUsable fat

The existence of suffor in chyle is doubtftil ; that of bile-constituenU, though pro-
bable, has not been demonstrated. Lactic acid was found by Lehmann in the chyle of
two horses, one of which had been fed two hours before death, with oats, the other with
starch.

Chyle is TeiT rich in alkali^ combined partly with albumin, partly with lactic and
sebadc adds ; hence the aqueous solution of the ash has a strong alkaline reaction,
and efferyesces with adds. Sulphates of the aUbali-meials are found in the ash, but
not in the diyle itsell StUpMocyanides are not found. Alkaline phosphates occur in
small quantity only, eyen afier the digestion of yegetable food. Thechkiides of sodium
and potassium occur in large quantity.

Iron is found in the serum of chyle, but its presence may be due to admixed blood-
cells.

^ During fluting or scanty nutrition, the chyle is poorer in solid constituents, espe-
dally flit and consequentiy has a turbid but not a milky appearance.

Food rich in fi^t whether animal or yegetable, increases the quantity of flit in the
chyle.

In the contents of the thoradc duct two hours after death, of a man killed by
drowning, Rees found 98*48 per cent water, 7*08 albumin, with traces of fibrin, 0*66
aqueous extract, 0*5 alcoholic extract 0*44 chloride, carbonate, and sulphate of potas-
sium, with traces of phosphate of potassium and oxide of iron, and 0*92 fatty matters.

F. Simon has giyen the following analyses of the chyle of three horses, the first fed
OD peas, the other two on oats :

Vol. L 8 Q

962 CHYME— CICHOBIUM INTYBUS.

T. II. IIL

Water 949*670 928-000 916-000

Fat 1-186 10-010 0*900

Albumin 42717 46-430 60530

Fibrin 0*440 0*805 0-900

Hematosin 0*474 trace 6-691

Extractire matter and ptyalin . . 8*360 6*320 5-265
Chloride and lactate of sodinm wiUi traces of

calcinm-salta — 7*800 6*700

Sulphate and phosphate of calcium with traces

of oxide of iron — I'lOO 0*850

1002-847 998*965 996*636

The first of these analyses does not, however, admit of direct comparison with the
others, as it eyidently applies to the organic matter alone.

In the chyle of a cat, Nasse found in 1000 pts. : 905*7 wat<>r, and 94*3 solid matter,
consisting of 1*3 fibrin, 32*7 fiittj matter, 48*9 albumin, globules resembling those ci
the blood, and extractiTe matter, 7*1 chloride of sodium, 2*3 other soluble salts, tnoa
of iron, and 2*0 earthy salts.

CHIMB. This name, now but little used, was applied to the products of digestion
contained in the small intestines^ before they haye been submitted to the action of the
bile and pancreatic juice.

OHIMOSZV. A peculiar nitrogenous matter existing in the gastric juioe (^. «.) ;

also called pepsin or gasterau.

CBYTOPBT&UITa. A name applied by Hausmann to certain slags &om blast-
furnaces, haying a broadly laminar structure. They are mainly ferrous silicatesi»
2Fe*0.3SiO*, the iron being partly replaced by calcium and the silica by alumina.
(Jahresber. d. Chem. 1850, pp. 26, 710; 1851, p. 768; 1856, p. 842.)

CBTTOSTX&BXTB. Radiate blast-furnace slags, having the oomposidoo of
augite, M'SiO' or HK).SiO*, the silica being partly replaced by alumina. (Haus-
mann, Jahresb. d. Chem. 1856, p. 843.)

CXBOnvlC CVMZVOZZ. An East Indian fern, the haiiy stem of which is
much used as a means of arresting haemorrhage. It contains wax, resin, tannic acid,
crenic acid, &c (v. B em m el en, Viertelj. pr. Pharm. v. 321.)

OICXB ASZBTmM. The Chickpea.'^The hairs of the stem, leaves, and
other parts of this plant exude an add liquid, containing oxalic, acetic, and perhaps
malic acid, and, according to Dispan, another acid peculiar to the plant

CZOHOXKVIK BVBZVXH. SeeEin>rvB.

CZCBOazUK JLHTSJIVS. Chicofy. — The root of this plant is extensiTelj
used for mixing with co£fee. The following table exhibits the composition of the
organic part of Sie wild and coltiyated varietfes, as determined by y. Bibra :

CultiTatod. Wild.

Fat, insoluble in alcohol ...... 0*07 0*47

Resin . 0*84 0*96

Organic acid, precipitable only by subacetate of lead . 1*01 1*18

Organic acid, precipitable also by the neutral acetate . 2*54 2*51

Sugar 22*08 87'81

Inulin 1912 10*90

Albumin 0*12 0*15

Tannic acid and volatile oil trace trace

Woody fibro 5421 4600

99-99 99^

The chief difference in the composition of the two varieties appears to be in the il-
lative proportions of inulin and sugar.

Ander 8on.(Hi£hland Agric. S^ Joum. 1853, p. 61) found in a specimen of chicorr
cultivated in Yorkshire, 1*6 per cent nitrogen and 3-6 ash ; in another, fipom the neigh-
bourhood of Glasgow, 1*5 per cent, nitrogen and 6*7 ash.

The leaves contain in 100 pts. 90*9 water and 1*42 ash. (Anderson.)

The composition of the ash of the root and leaves of chicory, as determined by
Anderson (loc. cit.\ and by Graham, Stenhouse, and Campbell (Chem. Soe.
Qu. J. ix. 45), is as follows :

CICUTINE — CIDER.

963

Composition of CHicoBT-AfiH in 100 ptfl.

Root.

Leaves.

Anderson. 1

Graham, Stenbouse, and Campbell.

Anderson.

Darkest

Scotch.

Yorkshire.

English

English.

Foreign. Guernsey

PoCaah ...

(Yorkshire.)

84*6

S7'I3

40^

41-41

46-6

Soda • • •

8-9

8-99

16 46

2-77

4*92

Xjtino • ,• •

10- 1

7-9

1088

10-53

6*79

ens

11-8

Magnesia .

6-7

4-1

5-K3

787

4*66

497

2-6

Ferric oxide . •

0-8

l-O

4-22

8-41

7-24

4 55

Silica

4-4

1-S

8*81

S61

12*76

10-52

Sulphuric acid (an-

hydride)
Phoapboric acid (an-
hydride)

15*2

6*1

1098

11*48

7'82

7 76

16 S

130

11*81

ia-»

9-60

859

Chloride of potaulum

—

1-6

,, sodium .

8*8

—

.—

Chlorine . . •

—

6-46

610

4-80

6-89

Carbonic add (anhT-

drlde) . . .

—

1*97

»I4

8-6I

4*12

20*6

99*9

99*8

100*49

IQO-OS

99-58

99*58

99-7

When chiooiy-root ifl roasted, sereral Yolatile products are given oft, and on con-
densing them, a yellowish liquid is obtained, which has a sharp unpleasant odour,
colours tlie skin permanently dark brown, and contains tannic add. The aqueous
infusion of the roasted chicory contains sugar, a bitter substance, empyreumatic oil,
substances which exert a strong reducing action on gold and silyer-salts, and organic
acids precipitable by lead-salts. It has a disagreeable taste, and, if taken in con-
siderable quantity, produces nausea and sometimes giddiness. (Handw. d. Chem.
iL [2] 24.)

CZCrmmL An alkaloid but litUe known, said to exist in the water-hemlock,
Oicuta virosa. (Polex, Arch. Pharm. xviii. 174. — Witts tein, Buchner's Bepert.
XTiiL 19.)

CZ9BB. A fermented liquor prepared from^ apples. Large quantities of it are
made in Herefordshire, Deronshire, and the acyoiniog counties ; in the counties of
Waterford and Cork in Ireland ; in Normandy and Picudy in Fnnce; in Belgium; in
Germany ; and in many parts of the United States.

The apples used in the preparation of cider, ripen at different seasons ; in this
country, the earliest be^ to fall from the trees at the end of September, but the ma-
jority do not attain their maturity till about the end of November or the beginning of
December.

To make good cider, it is necessary that the apples be quite ripe, to ensure which, it
is customary to leare them to ripen for a month or more after gathering ; they must
not, however, be allowed to get over-ripe, otherwise the quantity of sugar will diminish.
The average proportion of sugar in apples at different stages of maturity, has been
found to be as follows:

Unripe
4*90

Ripe.
1100

Over-ripe.
7-95

To make cider, the apples are thrown into a circular stone trough, usually about
18ft. in diameter, called tne chasej round which the runner^ a heavy circular stone, is
turned by one or sometimes b^ two horses; the pulpy fruit or " mist '^ is then enclosed
in coarse hair-cloths, and subjected to pressure by a screw-press, and the brown juice
which exudes is pour«d into casks placed either out of doors, or in sheds whero there is
a free current of air. Sometimes tne dry residue which remains in the bags, is mixed
with water, ^und again, and the liquor pressed out as before. This latter product
makes what is called ** water-cider," a thin unpalatable liquor which is given to the
labourers early in the year.

About three or four days after the juice has been transferred to the casks, it b^ns
to ferment, the thick heavier parts then subsiding to the bottom, while the lighter
become clear bright cider. This is then racked off into another cask, and the sediment
is put to strain trough Unen bafis, the liquid which oozes through being restored.

The fermentation is the most delicate part of the process ; alight fermentation leaves
the liquor thick and unpalatable ; rapid fermentation impairs its strengh and durabilty ;
and excessive fermentation makes it sour, harsh, and thin. Other things being equal,
that cider will probably prove the best in which the vinous fermentation has proceeded

3q 2

t)61 CIMICIC ACID — CIMOLITE.

Blowly, and has not been allowed to pass into tlie acetous. If the cider does not dear
spontaneously, finings, such as isinglaffl, eggs^ or blood, are added, aain the prepazmtion

of beer.

At the beginning of Jannaiy, the cider is moved into cellars, where, by large
growers, it is frequently stored in casks of great capacity, oontainiiig 1000, 1500, or
even 2000 gallons. In March, the liquor is bunged down; it is then fit for sale, and
may be used soon afterwards, though it wiU greatly improve by keeping: For bottled
or effervescing cider, the liquor should be bottled or wired down in the September or
October after it is niade ; some persons prefer an earlier time, the end of April or the
beginning of May. A more effervescent liquid is thus obtained, but oonsiderable loas
occurs from the bursting of bottles. (Penny Oydopetdia.)

The strongest cider contains in 100 volumes, 0*87 volumes of alcohol of 92 per oeot.;
the weakest^ 5*21 volumes. (Brande.)

CZMCSCZO ACZB. G»H"0' » ^ h(^' (^^'^^"> ^^^°^ ^^- liianii. eziv.

147.) — An acid, belonging to the oleic series, contained in the fetid oily liquid ^ected
by a kind of bug (Shaphigaater punctipmnU) when irritated. To prepare it^ the in-
sects are treated with strongalcohol, which extracts a brown resinous substance, then
macerated with cold ether. The solution thus obtained, yields the acid by evi^omtioii,
as a coloured mass ; it is purified by. converting it into a barium-salt, waafaii^ with
water and with dilute alcohol, then decomposing the salt with hydrochloric acid, and
drying the resulting fat between 40^ and 60*^ C. Two or three hundred of the ineects
yield about 12 grms. of the fatty acid : the insects freed from fat and dried, w^eighed
23 grms.

Cimicic acid is a vellow crystalline mass, having a peculiar rancid odour : lighter
than water and insoluble therein ; very little soluble in alcohol, easily in ether, from
which it crystallises by slow evaporation in stellate groups of colourless needles. It
melts at 44° C, and, when subjected to dry distillation, yields, besides pases^ an oil
which solidifies on cooling, and appears to contain some undecomposed acid.

Cimicic acid, treated with pentachloride of phosphartu, gives off hvdrochlaric add
gas, and forms a liquid which, when shaken up witn cold water, yielos chloride of
cimicyl, C'*H^0.G1, as a heavy oil, which solidifies at about 44^0., does not crys-
tallise distinctly ; dissolves in ether without alteration ; is immediately decomposed
by alcohol into cimicic ether and hydrochloric acid ; and by potash into cimicate and
chloride of potassium.

Cimicic acid in alcoholic solution is strongly add. It dissolves easilj, with aid of
heat, in aqueous alkalis.

The cimicates have the compodtion C^'H'^O*. Those of the alkali-metals
dissolve in a small quantity of water, but a larger quantity renders the solutioiis
opalescent; they froth with soap-solution, and are precipitated from their aqueoos
solutions by excess of alkali and oy chloride of sodium. The cimicates of the earth-
metals and heavy metals are nearly or quite insoluble in water and alcohol ; the iead-
sait only appears to be slightly soluble in ether. The nlver-salt blaekens quickly
when exposed to light.

Cimicate of Ethyl, C»»H«(C"H»)0*, obtained by treating chloride of dmicyl with
with alcohol and predpitating by water, is a light yellow oil, smelling like the fi«e
acid, but stronger : it is lighter than water ; does not solidify at 0^ C ; dSsolves readily
in alcohol ; turns brown when heated.

Syn. with Htdbidb or Cimkaiiyl (p. 988).

Lowig^s name for the radide C*H', which he supposes to exist in
cinnamic acid.

CXICOUTa or CZMOUEAV BA&TB, the eimolia of Fliny, which was used
by the ancients both medicinally and for deaning doths, uid which l»*m been con-
founded with fuller's earth and tobacco-pipe clay, is found in the island of Aigentien,
the ancient Cimolus, also in Bohemia and in Kussia. It is of a light greyish- white
colour, acquiring superfidally a reddish tint by exposure to the air; massive; of
an earthy, uneven, more or less slaty fracture; opaque when shaved with a knife,
smooth, and of a greasy lustre ; tenadous, so as not without difficulty to be powdered or
broken ; and adhering pretty firmly to the tongue. Its spedfic gravity is 218 — 2-30.
It is imroediatdy penetrated b^ water, and spUts into thin laminae of a curved slaty
form. Triturated with water, it forms a pappy mass; and 100 grains will sive to three
ounces of water the appearance and consistence of a thickish cream. If left to diy
after being thus ground, it detaches itself in hard bands, somewhat flexible, and stiU
more difficult to pulverise than before.

When it is ground with water, and applied to silk or woollen fabrics greased with oil of
.almonds, the oil 20 completely discharged by a slight washing in water, after the stufla

CINACROL— CINCHONA BARK. 965

hare been hnog up a da^r to diy, witliont the least itiQxiry to the beauty of the colour.
It ia still used bj uie uatires of Aigentiera for the same purposes as of old.

The following are analyses of dmolite: — a. From Argentiora, by Klapioth:— >
b. From Alexandrowski in Bossia, by Ilimoff: — c. A pseudomorph of augite (also
called anauxite), from the decomposed basalt of Bilin, Bohemia, by Bammobberg: —
d. Also ciMied pdikanitet from the decomposed granite of Kiew in Bussia, by Oucha-
kofH {Banundsber^s Mineralchemie, p. 583.)

SiO« A1H)« Fe*0» CaK) Mg«0 K>0 P«0» H«0

4L 63-00 28-00 1-25 — — — _ 120O - 99-25

b. 68-52 28-55 — — — .«.— 1200 - 9907

C 62-30 24-28 ■— 0-83 — _ — 12-84 - 99-70

d, 65*66 22-84 0-44 — 0*56 0-30 017 931 . 99-28

The first three analyses asfee nearly with the formula 2A1^0'.9SiO* + 6aq., which is
that of a ses^uisilicate, and leducible to 2a/K).8SiO* + 2aq. or a/«SiOVSiO* -r- 2aq. ; the
fourth contains the same proportions of silica and alumina, but only 4 at water,
2Al<0».9SiO' + 4aq.

Cimolite appears to be formed from augite containing alumina and magnesia, by the
action of infiltrating waters containing carbonic add, which carry away the magnesia,
leavinff a hydrous silicate of aluminium ; an addition of alumina may probably take
place uirough the accompanying decomposition of associated felspar. (Dana, ii. 164.)

onrACnU>XN A product of the action of iodine. on wormseed oil (q. v.)

cnHMMMMTB and onrJBaxVB-OAMFBOS. Constituents of wormseed-oil,
according to HizzeL

onHMVW^MMf ifEMMWBMMMf OISJBPBOVB. Products obtained, accord-
ing to Hirzel, by the action of iodine on wormseed-oil (q. v,)

OnrOBOVA BIIBB. Cortex CMnm^ C, Peruvianus, Quinquina, Cascartlla.^
This name is implied to the bark of the stem and branches of various spedes of Oin-
ekona and other genera of the order BubiacoB, sub-order Oinchonea. Those which are
obtained from trees of the genus Oinekona, are called true cinchona barks; they
contain quinine and dnchonine, and haye lonff been known for their antifebrile pro-
perties; Uie barks of the other genera of the sub-order above-mentioned, chiefly
iadenberffia and ExottemmOy are called false cinchona barks ; they contain certain
proximate prindples, likewise found in the true dnchona barks, namely quinic acid,
quinovie add, quinotannic add, and cinchona-red, but no alkaloids.

The antifebme barks were first introduced into Europe from Peru» about the year
1638, by the Countess of Chinchon, wife of the Viceroy of Peru (in whose honour the
name (Xnchona was given to the genus by Linnsus), and a few years later by the
Jesuits, and soon acquired great cdebrity for the cure of intermittent fevers, being
known by the names Pulvis ComitisstB, Jesuiticus, Cardinalis, Patrum. The trees
which yield them were first recognised and described, about a century later, by the
French astronomer La Condamine, in his journey in Peru.

The true cinchonas grow on the wooded slopes of the Cordilleras, from western
Venezuela to northern Bolivia, between lO^N. and 19<^S. latitude, in a narrow zone
extending through a vertical height of about 6400 feet The barks which are richest
in alkaloids, and are exported (Ca»cariUo*8fino*$), occur most abundantly {h)m 7^K.
to 15^ S. latitude, and as they require a cool moist climate, thev occupy the region
from 11,150 to 6400 feet above the sea-level, whilst those which contain smaller
quantities of the alkaloids, and are therefore not fit for exportation, occupy a warmer
and drier sone, between 6400 and 4800 feet in vertical beight With these also are
found the Ladenberffias, which produce false cinchona barks ; they extend also 2000
feet lower through the tropicd part of the continent The ExostemTnaa, which also
produce frlse dnchona barks, inhabit only the hot zone, and are found not only on
the continent, but on the islands. Since 1853, the most highly prized cinchonas have
been suocessAiIly cultivated in Java. The cultivation has also been attempted in
Algeria and in India.

The collection of the bark takes place in New Granada at all times of the year ;
in Pern and Bolivia, only in the dry season. The inner baric of the stems and larger
branches, after having been freed from the outer bark, is very carefully dried over a
fire for three or four weeks, the weight of the dried products being about one-third of
that of the fresh baric According to Karsten, a tree 60 feet high and 5 feet in
diameter, yields about 10 cwt of dry bark ; but such specimens are not often met with.
In Ecuador and northern Peru, the bark is taken chiefly from the branches; in
southern Pern and Bolivia, from both stems and branches ; it is dried in the sun,

3q 3

966 CINCHONA BARK.

either in the forest itself, or in drier situations lower down the hill-mda. AcoonUng
to Pasteur, the process of drying in the son is ii\jarioiis.

The TBUB cnroHONA basks known in commerce, are of three kinds, grty or hrwen^
^elloWf and red. They come to market either in rolled quills, or in flat or hollowed
oblong pieces of very varions dimensions. They have a more or less Bplinteiy-fil»T>ns
textore, contain the cinchona alkaloids, quinine, cinchonine, quinidine, &c., and whoi
coarsely powdered and heated in a test-tube, give off a red tar.

a. Grey Cinchona-barks. China fuaca s, grisea. — These barks are obtained
from the branches, and have therefore the form of quills ; they are whitish on the
outside, with spots of grey, greyish-brown or brown, sometimes black, fine-fissured, of
even fracture, splintery only on the inner surface, and contain more cinchonine than
quinine. Five species are enumerated, namely, Huanoco^ Loxa^ Fseudoloxa^ Huarna-
lies, and pale Jaen bark.

b. Yellow or Orange-yellow barks. Cinchona flava s. auranUaea, — These barks
are obtained from the stems and larger branches, and consist wholly or nearly so of
the bass or inner bark ; hence they have a fibrous or splintery texture. The aucaloids
contained in them are chiefly quinine and quinidine. The most important species is
the Royal, King's or Calisaya bark, of which there are three Tarieties, viz. —
1. Fine Calisaya bark, from V. Calisaya, which occurs either in quills or rolls, of
1 tol^ inches diameter, partly covered with the outer bark, and is then called Cinehma
Calisaya tecia s. oonvoluta; or in flat plates destitute of outer bark ; C. Calisaya nudxi
B. plana; this last variety is the richest of all the barks in alkaloids. — 2. C. Calisaya
morada, from C. Balifnana; and 3. C. Calisaya fibrosa s. scrobieulata, Thm
are four other species of yellow bark, viz. Cusco bark (Weddell) ; Carthagena or
Bogota bark, also called Cinchona fiava fibrosa; Cinchona fiava dura; uid.
Cinchona Pitaya.

e. Red Barks. Cinchona rubra. — These barks are obtained from the stems
and larger branches ; they are mostly of brown-red colour, with proportionately thick
outer bark, and strong fibrous or splintery bass. They contain more quinine than
cinchonine. The species are Cinchona rubra suberosa, from C.suoeirubra and C
rubra dura,

Falsb cinchona babks are derived chiefly from trees of the ^nera Ladenbergia
and Exostemma. They occur in rolls, half rolls, or flat pieces, having a pre-eminently
corky texture. They contain no cinchona alkaloids, and when coarsely pulverised and
heated in a test-tube, yield nothing but a dirty yellow or brown tar. The species are:
1. Cinchona de Para, ohtsisi^ ftomKLadenberaia. — 2. Cinchonanofia Grana-
ten sis, from Ladenbergia obl^mgifolia or magnifima, Pelletier and Caventou found in
it quinovic acid and an alkaloid; Winckler found quinovic acid and cinchona-bitter;
Hlasiwets found quinic acid, quinovic acid, quino- tannic acid, and cinchona-red.—
3. Cinchona novaBrasiliensis,ftomLadenbergiaRiedelana,BaidtocorittdBqTdme
and quinovic acids. — 4. Cinchona alba Granatensis, from L. macrocarpa, said
to contain alkaloids, but the statement is doubtful. — 6. Cinchona bicolorata s.
Atacamesf, s. Pitoya, said to contain an alkaloid pitoyine. — 6. Cinchona
Caribaa, from Exostemma CarilxBUin, contains quinovic acid. — ^7. Cinchona Sta.
Lucia, s. Piton, s. Martinicensis, from ExostemTnafloribttndum,

The organic constituents of cinchona barks, are quinine, cinchonine, and two or
three isomeric modifications of those bases ; aricine ; quinic, quinovic and quinotannic
acids ; cinchona-red; a yellow colouring matter; a green fatty matter; a small quantity
of volatile oil, having the odour of the bark ; together with starch, gum, and woody fibre.

The ash of cinchona barks consists chiefiy of carbonate of lime, and varies in
quantity from 0*68 per cent Xia Calisaya bark), to 8 '4 (in ash-bark or pale Jaen
bark). The acids of the bark are neutralised, partly by the lime, partly by the alka-
loids, and accordingly analysis appears to show that the lime diminishes in proportion
as the bark is richer in alkaloids. Some barks, e.g. Calisaya and Huanooo, yield ashes
of a green colour, arising from manganate of potassium (Futtfarcken, Phaxm.
J. Trans, xi. 129). Reichel found in the ash of various cinchona barks, potash, lime,
magnesia, silica, and sulphuric acid, with smaller quantities of alumina, iron, manga-
nese, phosphoric acid, and chlorine.

The first chemical examination of cinchona bark appears to have been made in 17S5
by Hermbstadt, who obtained from it the calcium-salt of quinicacid, which he
designated as essential salt of quinine. Schneider in 1807 and VanqueUn in 1808,
separated quinic acid from the calcium-salt Quinotannic acid was discovered by
Deyeux in 1793, and obtained in more definite form by S%uin, in 1797. Cinchona-
bitter and cinchona-red were obtained from red cinchona bark by Renss in 1810.
At this time, ten years before the discovery of the cinchona alkaloids, Beizelius made
a quantitative examination of a yellowish-brown cinchona bark, and found in it 0-5

CINCHONA BARK. 967

per cent, of green soft resin, which quickly hardened, 7*36 quinotannie acid, 6*87 bitter
8jrupj extract (this contained the aUcaloids), 2-6 qninate of potaasium and quinate
of calcium, coloured by a small quantity of extractive deposit, 1*25 extractive
deposit dissolved out by carbonate of potassium, 2*70 amylaceous gum and 73*75 woody
fibre.

Cinchonine appears to have been obtained in an impufe state by Gomez of Lisbon
in 1811; but its true nature remained unknown till 1820, when Houton-Ijabillardiere
first drew attention to the alkaline reaction of the substance obtained by Gromez, and
communicated his observations to Pelletier and Caventou, who, in the same year, suc-
ceeded in isolating, first cinchonine, and afterwards quinine, and in proving them
to be true vegetable alkaloids. Several isomeric modifications of these alkaloiib were
afterwards discovered and variously named; but according to Pasteur (Compt rend.
xxxvL 26; xxxvii. 110), whose results appear to be the most exact, their number may
be reduced to four, namely, cinchonicine and cinchonidine isomeric with cincho-
nine ; quinicine and quinidine isomeric with quinine. Cinchonicine and quin icine
are produced by the action of heat on cinchonine and quinine respectively ; cinchonidine
is found in certain cinchona barks, namely, Huamalies, Maracaibo, and Bogota barks,
and quinidine is obtained from the mother-liquors of the manufacture of sulphat-e of
quinine.

The three isomeric bases of each group are distinguished by their optical rotatory
power. (See the several Alkaloids.)

Aricine was discovered in 1829 by Pelletier and Corriol (J. Pharm. xv. 676),
in a white cinchona bark, from Arica. Elaborate examinations of various cinchona
barks, were published by Reichardt in 1855, and by Beichel in 1856 ; and lastly, in
1860, De Yzy published his researches (BonplandiOy viii. 270), on the Cinohona 6al^'
saya cultivated in Java.

Cinchona barks are employed medicinally in the form of tinctures and infusions, and
were used in this manner, for their febriftige and tonic properties, long before the dis-
covery of the alkaloids ; but as these qualities are likewise possessed by the pure
alkaloids, and the administration of these alkaloids is, in many cases, much more con-
venient than that of the bark in substance, the alkaloids, especially quinine in the
form of sulphate, are prepared from the barks on a very large scale ; — ^the value of a
bark to the manufacturer may indeed be said to depend on the quantity of sulphate of
quinine that it will yield. It is found, however, tnat the medicinal properties of the
barks are due to the quinic and other acids which they contain, as well as to the
alkaloids, and consequently that the bark in substance cannot in all cases be advan-
tageously replaced by the pure alkaloid. At one time indeed it was supposed that the
medicinal efficacy of the Darks depended chiefiy on the tannin contained in them.
Beizelius wrote in 1831 {T^aitS de Chimie, Paris, v. 587) : " There is a law in Sweden
in virtue of which, every cinchona bark imported into the countiy must be tested with
infusion of gpalls, ferric sulphate, solution of gelatin, and tartar emetic ; and it is proved,
by an experience of sixteen vears, that the most efficacious bark is that which gives
the strongest precipitate with solution of gelatin and tartar-emetic, in other words,
which contains most tannin." The barks ymich. appear to be best adapted for medici-
nal use are, the fiat Calisava and the Huanoco barks, the former containing the largest
proportion of quinine and quinotannie acid, while the latter is richest in cinchonine
and quinic acid.

BeactioTU of Cinchona Barks. — The aqueous infusion of these barks contains the
alkaloids in combination with quinic and the other acids, — and as these salts, and
likewise the starch, are more soluble in hot than in cold water, the liquid always
becomes turbid on cooling. To extract the whole of the bases, it is necessary to
acidulate with hydrochloric or sulphuric acid.

The solution thus obtained may be tested :

1. For alkaloids, which, if present, will give a white precipitate with tannic aad,
and a yellow civst^line precipitate with dickUmde of platinum. Another mode of
testing for the alkaloids, is to precipitate the acid solution with carbonate of sodium,
and distil the precipitate with excess of caustic alkali, whereby a distillate of chinoline
(p. 869) will be obtained.

2. For Qui no-tan nic acid. — White jRecipitate with soluHan of gelatin ; green
with/<;rrac Baits; dirty white with tartar-emetic.

3. For Quinovic acid. — ^If this acid is present, sulphate of copper first colours the
liquid green and then throws down a precipitate, which when collected and washed,
has a bitter metallic taste. Winckler proposes to estimate the relative value of cin-
chona barks by the amount of quinovic add thus precipitated, inasmuch as the bitter-
ness of a bark depends partly (and in the case of the false barks, exclusively) on the
presence of quinovic acid. #

4. For Quinic acid. — This acid distilled, with stdphurie acid and peroxide ofmanm

3a4

968 CINCHONA BABK.

yaneae, yields a diatillato of quinone, which is a jdlow czTitallisable sabstanepv lumqg
a pongeDt odour, and soluble in water. The aqueous solution mixed with ammonia^
absorbs oxygen from, the air, and assumes, first a brown, then a black colour ; a re-
action whidi will indicate the pfresenoe of very small quantities of quinie acid. CbHo-
rine-water changes the colour of the aqueous solution of quinone from yellow to bright
green. The formation of quinone in this manner is proposed by Stenhoase (Mem.
CheuL Soc ii 226), as a means of distinguishing between true and false dndMHia
barks, the former alone containing quinie acid. According to other authoritiea, how*
ever (p. 064), this acid is likewise present in some of the false cinchonas.

For the quaniitative estimation of the alkaloids, the following methods may be used.

1. One drachm of the finely powdered bark is to be boiled for a few minntea with
an ounce of water and half a drachm of strong acetic add ; the liquid filtered ofl^ the
residue boiled with a little dilute acetic acid ; the liquid again filtered ofl^ and the
powder washed ; the whole of the liquid evaporated to dryness on a water-bath; and
the extract dissolved in a little water and again evaporated, to expel all the free acetic
add. The residue is then to be treated with absolute alcohol and blood-chaicoal ;
the colourless solution filtered of^ and the residue exhausted with alcohol. To this so-
lution a few drops of hydrochloric add are to be added, and next a solution of chloride
of platinum as lon^ as it causes turbidity; and the predpitate of chloroplatinate oi
quinine and dnchcMiine tzansferred to a weighed filter, washed with alcohol, dried and
weighed. The platinum-salt of quinine contains 44*8 per cent, of that base ; the cin-
chonine-salt 48 per cent, of dnchonine : hence the propoxtion of the two alkaloids maj
be found by tiie method of indirect analysis ^p. 224) (buf los). The alkaloids might
also be predpitated by tannic add and infusion of gall-nuta.

2. Fifty grains of the pulverised bark is treated with a little dilntedhydroehloric acid ;
the liquid filtered, and the residue washed with a mixture of alcohol and a few drops
of the same acid The dark brown solution is then mixed with a little powder of hy-
drate of lime, so as nearly to decolorise it, and the precipitate, being thrown on a filter,
is washed with alcohoL The liquid contains the organic bases in the free state. It is
to be neutralised with hydrochloric add, diluted with water, and freed from alo^iol
by evaporation. When it is reduced to two or three drachms measure, the bases axe
to be tmrown down with solution of caustic ammonia; andthepredjpitate is to be filtered,
washed with cold water, dried, and weighed. By digesting it with ether, the quinine
is dissolved, and the dnchonine remains behind.

As the alcoholic s<^Qtion of the bases thrown down by the alkali is often rather
strongly coloured, and requires to be decolorised by animal diarooal, alum, protochloride
of tin, or hydrate of lead, which occadons loss, Thibouwery extracts the alkaloids
from the precii>itate by oil of turpentine, or other non-oxygenated oil, and Babonzdin
efiects the solution by means of chloroform. The same object is attained, according to
Badollier and Scharlan, by subjecting the bark, before treating it with addulated
water, to the action of dilute potash, which removes the tannic add and the dnchona-
red.

3. A quarter of a pound of the coarsdy powdered bark is boiled for half an hour
with very dilute hydrochloric acid ; this operation is repeated on the filtered residue ; the
final residue is washed with water ; the wnole of the liquors evaporated to diyness over
the water-bath ; and the extract redissolved in faintlv addulated water, on the bath.
Much of the dnchona-red will remain undissolved The filtrate is to be concentrated
to a small bulk, its bases precipitated bv ammonia, and the mixture drained and washed
with cold water on a weighed filter. The quinine and dnchonine may then be sepa-
rated and determined, as above, by means of ether.

4. An ounce of the pidverised bark is digested with five ounces of water containing
hydrochloric acid {\\ drachm of add to a pint of water); the extract is pressed through
linen, the operation being repeated three times with each four ounces of the addulated
water ; the extracts are then evaporated on the water-bath to six ounces, and the reddne
washed. From this solution, the alkaloids are predpitated by soda-ley, till an alkaline
reaction is produced; the liquid is then supersaturated with acetic add; and after the
cinchona-red has separated, the nearly limpid liquid is to be filtered. The filtrate
is again predpitated with soda-ley ; the precipitate left to settle for a dav; the dear
liquid decanted ; the predpitate coUeeted on a small filter, and left to dram well ; the
still moist filter, with the precipitate, repeatedly shaken up with chloroform; the dear
chloroform containing the alkaloids poured into a tared capsule ; the operation re-
peated three times, with fresh chloroform ; and the liquid left to evaporate* in the cap-
sule: the net weight gives the total amoimt of the alkaloids. The quinine may then
be completely dissolved out by ether, the residue in the capsule consisting whoUy of
dnchonine, which may be weighed. In this manner the relative quantities of the two
bases are detennined. ^

A crystalline deposit in the amber-like mass of quinine, indicates the presence of

CINCHONA BARK — CINCHONA-RED.

969

iflomerie alkaloids. To separate cinchonidine (Pasteur^s, p. 965), dissolve 1 gramme
of the mass in 15 drops of dilute sulphuric acid and 24 drops of water, then add 20
drops of ether and 30 drops of ammonia : the quinine will then dissolve, leaving the
cinchonidine, provided the quantity of the latter is not less than 10 per cent. Smaller
quantities mav be separated by means of ether already saturated with cinchonidine,
which ^rill still dissolve quinine. (Zimmer.)

Quinidine may be separated firom quinine by the greater solubility of its oxalate in
cold water; on treating a solution of quinine with oxalate of ammonium, tlie quinine
is almost wholly precipitated as oxalate, whilst the quinidine-salt remains dissolved.

The following table (p. 968) exhibits the proportions of the alkaloids contained in dif-
ferent cinchona-barks. The determinations must not however be regarded as very exact,
partly because the barks known in commerce by the several names in the table are
usually mixtures of different sorts, partly also because different methods of analysis
often sive different results. According to Wittstock, the precipitation of the bases
from the acid extract of the bark by alkalis, is not complete, inasmuch as a somewhat
considerable precipitate may afterwards be obtained witn tannic acid. Moreover, the
precipitates which contain the colouring matter always retain a certain portion of the
alkaloids, and charcoal, if used to decolorise the extract^ carries down nearly the whole
of the bases ; lastly, the separation of quinine from cinchonine by ether is by no means
complete.

Beichazdt has determined the whole of the constituents of various cinchona-barks.
The following is an extract from his table :

Compo&iiion of Czncrona-Babks.

CfHckona

Cinekona

Cinduma

G^tdiona

Cinekona

QuillilM

JIava
JlbroM.

rtthra.

Htianoco.

plana.

Calitoffa
eonvoluta.

0-706

0 99)

0-8M

2-701

0-650

Cinchonine •

0-S45

(•389

2-240

(^264

0-827

AmnMmia •

0^66

0-100

(^086

0-187

0-123

Qttlnic add .

G>730

6-019

8-965

6-944

7-245

QulDovic mM

0 196

0-sn

1-786

0-6H4

0-679

Qulnotonnic acid

0-964

8-179

0-515 -

8-362

2162

Clochona-red

0-988

4*884

0-722

0-706

Humic acid . <

^7»

g-gns

27-068

16-885

27-345

Celluloie

S9-I46

47-777

25-4S9

45-522

32-658

ToUl of organk consMtuenU

77-604

74*»4

66-514

77-968

72-777

Inorganic oonatituenta .

1-684

1-661

2-518

1-224

1-650

In the bark of Cinchona Calisaya^ cultivated in Java, De Yiy found ordinary
quinine, crystallisable quinine, quinidine, cinchonine, and quinovic acid. The stem-
bark was found to contain 3*90 per cent, of quinine and quinidine ; the root-bark
1-136 of the crude alkaloids; the root-wood 0*06, chiefly cinchonine; the stem-wood
0-08, quinine and cinchonine ; the young branches scarcely a trace of alkaloids ; the
leaves none. Quinovic acid was found more abundantly in the wood than in the bark ;
in greatest quantity in the root-wood, and least in the leaves. The bark of Cinchona
lueumafolial yielded only 0-4 per cent, of crude alkaloids. (Handw. d. Chem. ii [2] 971.)

CZVCBOVA-Ka]>> A constituent of cinchona bark, produced from quino-
tannic acid by atmospheric oxidation. It may be extracted by boiling the bark witii
water, treating the residue with ammonia, and precipiteting the ammoniacal filtrate
with hydrochloric acid, washing the resulting precipitate of quinovic acid and cinchona-
red, and boiling it with thin milk of lime : quinovate of oilcium then dissolves, and
cinchona-red remains undissolved in combination with lime. The residue, after being
washed with water, is treated with hydrochloric acid ; then washed aeain, dissolved in
ammonia, and reprecipitated by hydrochloric acid ; dissolved in alcohol, after another
thorough washing; and the filtrate evaporated to dryness over the water-bath*
(Schwarz, Ann. Ch. Pharm. Ixxx. 332.^

Cinchona-red is an amorphous, chocolate-coloured or red-brown, nearly black mass,
almost insoluble in water, easily soluble, with red-brown colour, in alcohol, ether, and
alkaline lyes, also in strong acetic acid. It is decomposed by heat, givine off copious
red fumes, and yielding by dry distillation, an empyreumatie oil, pyrogamc add, and
an impure, volatile, carmine-coloured, aromatic substance, insoluble m water, but soluble
in alcohol, ether, and alkaline liquids. (Boissenot, J. Pharm. [3] xxv. 199.)

The formula of cinchona-red is CH'O*'*, according to Schwarz ; 0'H*0* according to
Boissenot; it is doubtful whether it has ever been obtained pure. The bark of^n-
ehona lancifoHa (Mutis) contains, according to Reichel, from 1 to 2*5 per cent of it;
-other cinchona barks are said to contain a larger amount

*Mi|aoqoai3

66 '.:<6~.:-6^6

'•U|uin5

teco r» op

666 >6

6 16

O 3

i
i

• ^ S %• 9

•0 w .e «e = o S
3 * = Si? ^

•s^n.

■9a|aoipa{3

6-66 '6666

ft< 6 = 6

e ■

-9U|p|(ioqdu|3

■8U|U{n{)

11 I I M l|?

o6o9-«

ICO — r^^to I I
■666666 I I

11 1 I I I 1^2

S I

666

is!' I

n
M
M

o
H
o

••»

O
>4

-4
M

J3
9
<

8«

*9U|aoq9UO

6«4i.^66^^::.«<«t.::.^:^A.:.&66

*ja)piaoq3a}3

1 1 1 r 1 1 1 1 1 M 1 1 1 i|i M

valuing)

e*w

•» o«

M;ijgi III I igs^SlSi

A-

*9a|iioq9U}3

*3U]piiioq9Ui3

. ^

1^^

6:9 '6 '.:.6dx-666 '6-6

•o —

I I i I I i I I I I I llfl I

"III

•»U|ilIiiJ)

3
<

'9a{aoq9a!3

V •BUiuinft

«■» — oo . c« fo «<9 »e « CD s»«o
666-6 '<f4^^J«^6-666

I I I

e
a

US' '-11

PS OX C (S

oDo^o^ — dno4^Sm6?i<>eosac&^«m
<bI^--^(»«666^^-6;u-66666

oc »e «
^666

66666666

rf? ** «f ;o « ^o

j;i6?«-^<:^^-^6

'9aiaoq9U|Q

-eoiuint)

I
I

t) 6

/• **
§•

■5 C«-S

I 1^^

1 1 1 1 ilI5

ooo

66«^6

3o28Rr*®
ci« 04 -•6 — -^6

6666

^<s

666^

■9a}uoq3af3

I I

III igl II I I I I llfgl

'auiuinf)

.!. — 6^e«e4fi«0'~e«nm^c«<^e<4<'h

CINCHONA-TANNIC ACID - CINCHONIDINE. 971

CXirOBOir A-TAWXO ACZ9. Syn. with Quinotankio Aoro.

cnrCBOWSTXWB* A prodact of the decomposition of dnehonine by peroxide
of lead (p. 074).

cnrCHO Ji lOUl «■ C^B'^N'O. (Pasteur, Compt rend, zzzrii. 119; Chem.
Soc Qu. J. vi. 273.) — ^An alkaloid isomeric with cinchonine, and produced from it
under the influence of heat Any salt of cinchonine may be transformed into the
corresponding cinchonicine-salt by heat ; but to make the transformation complete and
prevent decomposition, the heat must be moderate and the salt must be kept for some
time in a resinous state. The change takes place most easily with the sulphate, which,
when mixed with a small quantity of water and sulphuric acid, remains melted at a
very moderate heat, even after all the water has been expelled^ and if kept in this
state for three or four hours between 120^ and 180^ C, is completely converted into
sulphate of cinchonicine. Pasteur is of opinion that the resinous state of the fused
sulphate is essential to the molecular transformation which takes place. The base
may be separated from the sulphate by precipitation with an alkali

Cinchonicine is nearly insoluble in wat^ but ver^ soluble in alcohol, whether anhy-
drous or of ordinary strength. It is very bitter, and is precifiitated from its solutions in
the form of a liquid resin. It deflects the plane of polarisation to the right It unites
easily with carbonic acid, and separates ammonia from its salts at ordinary temperatures.
It possesses febrifuge properties. It is distinguished from cinchonidine by its action on
polarised light, and by not being ciystallisable ; from cinchonine also by the latter
property, and by its much greater solubility in alcohol, and greater bitterness.

CZM<«OWZ»ZVB. C»H»*N«0, or C»«H«N«0? (Winckler, Repert Pharm.
[2] xlviii. 384; xlix. 1. — ^Leers, Ann. Ch. Pharm. Izxii. 147. — ^Pasteur, Compt
rend, xxxvi. 10; xxxvii. 110; Chem. Soc Qu. J. vi. 275. — ^Bussy and Guibourt,
J. Pharm. [3] xxii. 401.) — This alkaloid was discovered by Winckler in a bark re-
sembling the Huamalies cinchona-bark, also in that of Maracaibo. It has likewise
been ibund, accompanied by a small quantity of quinine, in the Bogota cinchona-bark
(p. 965). According to Pasteur, it is isomeric with cinchonine, (C"H*^N'0). The
Qerroan chemists generally pive it the name of quinidine.

Preparation. — Cinchonidine is extracted from the barks by the same processes as
quinine and cinchonine (pp. 966, 971), and purified by ciystallising it several times
from alcohol of 90 per cent, till the solution no longer deposits any resinous matter by
spontaneous evaporation ; then reducing the crystals to fine powder; agitating with ether
till the powder no longer exhibits with chlorine- water and ammonia, the peculiar green
colouring produced by quinine and quinidine ; and finally, recrystallising from alcohoL
(See also Zimmei^s method of separation, p. 967.)

Properties. — Cinchonidine separates from its alcoholic solution by slow evaporation
in anhydrous rhombic prisms, of 94^, hard, with vitreous lustre, and having their faces
deeply striated. The same striae are observed on the faces which replace the obtuse edges
of the prism, and the crystals cleave perfectly in the direction of these faces. The
prism is modified by two brilliant faces, too inclined at an angle of 114^ 30', and
restinff on the acute edges. The crystals are easily reduced to a perfectly white pow-
der, yndch becomes electric by friction. They do not taste so bitter as quinine.

Cinchonidine is very sparingly soluble in water, 1 pt of it dissolving in 2180 pts. of
water at 17^ C, and in 1858 pts. at 100^. It diraolves in 12 pts. of aloohol of sp. gr.
0*835 at 17^ ; ether dissolves but little of it^ 100 pts. of the solution containing odiy
0*70 pts. of dnchonidine. (Leers.)

A solution of cinchonidine in absolute alcohol at 13^ C, deflects the plane of polari-
sation of a ray of light strongly to the left; [a] — —144*61^. (Pasteur.)

According to the analyses of Leers, cinchomdine contains from 76*40 to 76*88 per
cent carbon, 7 '70 — 7*81 hydrogen, and 9*99 nitrogen, whence Leers deduced the for-
mula C"H«NH), requiring 76*60 per cent C, 7*80 H, and 9*93 N, whereas the formula
of cinchonine, C*H«*N*0, requires 77*9 C, 7*79 H, and 9*09 N. Nevertheless, Pasteur
regards cinchonidine as isomeric with cinchonine, inasmuch as it is transformed into
cinchonicine by heat> without alteration of weight, in the same manner as cinchonine.

Decompositions. — Cinchonidine melts at 175^ C, and solidifies in a crystalline mass
on cooling. When stronglv heated in contact with the air, it bums with a smoky flame,
giving on an odour like that of bitter-almonds or quinine, and leaving a considerable
quantity of charcoal. Distilled with hydrate of potassium and a small quantity of
water, it yields the same mixture of volatile bases as cinchonine (p. 869^. When
diffhsed in flne powder through chlorine-water, it dissolves without perceptible change,
even after addition of ammonia.

Commercial cinchonidine is ^ten contaminated with quinidine, the presence of
which may be detected either by the green colouring produced by chlorine and am-
monia, or by exposing the recently deposited crystals to the air ; the cryst^ils of qui-
nidine then effloresce without losing their form, assuming a dull white appearance,
while the crystals of cinchonidine retain their transparency.

972 CINCHONIDINR

The Salts of Cinehonidine are for the most pozt more eolnblem water than tinae
of quinine ; thej are Teij soluble in alcohol, but nearij ineoluble in ether. Tfe
aqueoufl solution yields with alkalis and their carbonata, white pulTemlent pncxni-
tates, which become arstalline when left at rest ; and are insoluble in excess of &e
reagent. With phosphate of sodium^ merourie chloride, and nitrate of silver^ tfaej
proauce white precipitates; light yellow with chloride of gold, onng^jellow with
dichloride of platinum, and brown with chloride of palladium. With ~_ ~
of ammonium they yield a white, and with tannm, a dirty yellow precipitateL

HTDROCHLOitATBS OF CiHCHONmiNB.— The neutrsl salt, G"H**NH>.HG1 (at 100^ CL),
forms large rhomboidal prisms, having a vitreous lustre* soluble in 27 pts. of wa.ter at
17^ C, rery soluble in alcohol, nearly insoluble in ether.

JnofKtii (meam), Cakmlutkm,

Xeert. Leen. caerhanlt.

At 100® C. C»"B*N«O.HCLaq. C*JBP«NK).HCL

Carbon . • • 64-34 64*19 69*67

Hydrogen . . 7*17 7*13 6*97

Chlorine . • 10*06 10*54 10*31

The acid salt, C*'H'^NK).HC1 + aq., forma large ciystals, very soluble in water and
in alcohol ; after drying over oil of vitriol, they give off 5*8 per cent water ; the cal-
culated quantity for 1 at. is 51, according to L^rs* formula ; 4-5 acoording to that
proposed by Gerhardt

CahmUMm.
L«ert. Gnfaaadt.

At lOOO C*

C"H«N«0.2RCL

C-H^N'O.Ha.

Carbon .

58*30

57-93

63-32

Hydrogen
Chlorine •

7*12
18*98

6-97
18-99

6-33
18-73

Chloromereurate of Cinehonidine, C"H»<N«0.2(HCl.HgCl)? aystallises ia
shining nacreous scales, sparinffly soluble in cold water. Analysis gave 34*77 per cent. 0,
4*01 H, 31*9 Hg, and 22*46 (S, agreeing nearly with Ci*H»NK).2(HCLHgCl), which
requires 34*52 C, 3*83 H, 31*97 Hff, and 22*63 CL The formula C**H*<NK>.2(fiCL
HgCl) would require 35*8 C, 3*51 1^ 29*8 Hg, and 21*18 CI.

The ehloroplatinate, C^H'^N'O.HCl.PtCl'? is an orange-colouied preeipttate,
containing atllO^ C. f^m 27*05 to 27'17 per cent, platinum, whence Leers aednees the
formula C*'H'>irO.HCl.PtCl* + 2a^., requiring 2704 per cent Yt, whereas Gerhaidt
proposes C"H**N*0.HCLRC1', which requires 27*36 per cent It is not probable ihaX
the salt should retain 2 at of water at 110° C.

Chlobatb of CmcKOMiDiNE, obtained by decomposing ihe neutral sulphate with
chlorate of potassium, ciystallises from alcohol in long silky prisms, grouped in tufts.
It melts at a gentle heat» and decomposes with loud explosion at a higner tenqperatozeu

HTDBOFLU^n OF CiKCHONiDiMB fopms silky needles, vezy soluble in water.

Htfosulpjuth of Cutcrokidinb, obtained by jiredpitating the neutral sulphate
with hyposulphite of sodium, crystallises on coohng^ in long asbestos-like needles,
sparingly soluble in water, easily in alcohol.

NiTRATi OF CnfCHONiDiNS is obtained in mammellated crusts, having the appear-
ance of enamel, and very soluble in wate&

SULPHA.TBS OF CmcHORiDiKB.--The neutral salt, 2C»H»«NK)JH«S0* (at 100*>G), \

crystallises in long silky needles grouped in stars, neutral to test-pap^. One pt of
the salt diBsolves in 130 pts. water at 17° C, and in 16 pts. at 100° ; it is very soluble I

in alcohol, nearly insoluble in ether (Leers); it dissolves at mean temperatures in
30—32 pts. absolute alcohol, and in 7 pts. alcohol of 90 per cent (Bussy and
Guibourt)

Anaiy^i* {mean). Ca/culatidn,

IfCcn. Leers. Gerhardt.

At 100° C. 2C"H«N«0.H*S0« 2C*H»«N«0.HWO*

64-75 65*25 67*20

7*05 6*95 6*72

12*01 12-08 11*20

The acid sulphate is obtained by evaporation in vacuo, as a ciystalline mass com-
posed of shining asbestos-like needles.

Sulphate of lodooinchonidine. — Cinehonidine forms with iodine and sul-
phuric acid, a ciystalline salt, which acts upon light in the same manner as the cone-
spondiag salts of quinine and cinchonine, also two'other salts, one yellow and the
other oUve*groen, which do not exhibit these peculiar optical properties. (W. B. Herft>
path, Chem. Soc. Qu. J. zL 130.)

CmCHONlNE. 973

•i

I
I

Sjf Analysis
At 100° G.

Carbon . «
Hydrogen
Iodine .

63-87

6-92

29-84

Acetate of Cinekonidine crystallises in long silky needles, which are very
sparingly soluble in cold water, and gire off part of their acid on drying. The but y rate
and valerate form mammeUated crosts, having the odonr of the respectiye acids.

The citrate forms small needles, haying but little lustre. The iippurate crys-
tallises in silky needles, having the aspect of fem-leayes, yeiy soluble in water and
^ alcohol. The oxalate separates on cooUns in long silky needles, from a mixture of

^ the hot alcoholic solutions of oxalic acid and dnchonidine. The mother-liquor depo-

P sits by spontaneous evaporation, dull white, mammellated crusts. The quinate crys-

^ tallises in small needles, very soluble in water and in aloohoL The neutral tartrate

I forma beantiM needles, having a vitreoul' lustre. The acid tartrate fonns small

nacreous needles, veiy sparingly soluble in watar.

Mbthtl-cihohonidiwe, C»"H«VCH«)N«0, or C"H"(CH")N»0 ? (Stahlschmidt,
Ann. Ch.Pharm. xc. 218.) The hyariodate of this base is obtained by the action of
> iodide of metiiyl on cinchonidine. It czystallises in colourless shining needles, con-

taining:

By CaicMlaUim,
C»H«(CIP)N»O.HI C»H«^CH«)N«0.m.

63-76 661

6-89 60

' Iodine . . 2984 29*87 28*0

Oxide of silver converts it into a basic compound resembling methyl-cinchonine.

CZVCBOirnnB. C»H"N«0, or C^iP*^»0«. (Fourcroy, Ann. Chim. viii. 113 ;
ix. 7. — ^Vauquelin, ibid, lix. SO, 148.— Gomez, Edinb. Med. and Suig. Journal, 1811,

Oct p. 420 ^Pfaff, Schw. J. x. 366.— Pelletier and Caventou, Ann. Ch. Phys.

XV. 291, 337. — ^Pelletier and Dumas, ibid. xxiv. 169. — Liebig, Ann. Ch. Pharm.
zxvi. 49. — Regnault, Ann. Ch. Phys. Ixviii. 113. — Gerhardt» Bev. scient x. 886;
Traiti, iv. 106.— Laurent, Ann. Ch. Phys. [3] xix. 863.— S tree ker, Compt rend,
xxxix. 68.)

This alkaloid exists, together with quinine, in most of the true cinchona-barks, most
abundantly in Cinchona Huanoco, C. HuainalieSf C, rubiyinoea, and C. fiava fibroea,
(See table, p. 968.)

Preparai^on, — ^All methods of extracting the alkaloids from cinchona-barks consist in
treating the barkwith a dilute acid, and precipitating the alkaloids from the add extracti
with lime or carbonate of sodium. The general mode of proceeding is as follows :

The bark, reduced to powder, is boiled for an hour or less with 8 or 10 times its
weight of water, acidulated with 10 per cent, of strong sulphuric acid, or better, with
26 per cent, of hydrochloric acid ; tne decoction is strained through a cloth ; and the
residue is boiled a second and sometimes a third time, with more and more dilute acid
till the marc is completely exhausted. The extracts, after cooling, are mixed with a
slight excess of milk of lime, added by small portions, to precipitate the alkaloids together
with the colouring matter. The precipitate is left to drain, and submitted to a gradu-
ally increasing pressure, the liquids which run off firom the cloths and from the press
being collected in a single vessel ; they yield after a while a f^«sh deposit. The pressed
cake is now dried, and macerated with alcohol in a dosed vessd heated over a water-
bath. The strength of the alcohol used depends upon the quality of the bark under
treatment. For Calisaya bark, which is very rich in quinine, alcohol of 76 to 80 per
cent, is suffidently strong ; but barks which contain a smaller nroportion of quinine,
require alcohol of 86 to 90 per cent., because dnehonine is mudx less soluble in weak
alcohol than quinine.

If the bark is rich in dndionine, and the quantity of alcohol used is not too laige,
the dnehonine is deposited in the crystalline state as the alcoholic extracts cool, and
an additional quantity may be obtained by decanting the supernatant liquid, and dis-
tilling off half or two-thuds of the alcohol. The quinine remains in the mother-
liquor and may be separated in the form of sulphate. (See Quihinb.)

If on the other hand the bark contains more <|uinine than dnehonine, it is best to
treat the alcoholic extract with dilute sulphuric add, and remove the alcohol by
distillation. The greater part of the sulphate of quinine then separates in a crystal-
line mass, the rest, together with the sulphate of cinchonine, remaining in the'mothejv
liquor. By predpitating the two alkaloids with carbonate of sodium, redissolving in
smphuric add, and recrystallisin^, a further separation may be effected ; or they may
be predpitated by a caustic alkali, and separated by ether, which dissolves the quinine
much more readily than the cinchonine (p. 966).

Carbonate of sodium is a better predpitant fbr the alkaloids than lime, because thej
are soluble to a slight extent in lime-water and chloride of caldum.

Oil of turpentine, fixed oils, and chloroform may be used instead of alcohol for dis-
solving the aUuJo'ids from the crude predpitate thrown down by lime or soda; and

974 CmCHONINE.

these Bolventfl hare the adrantage of not taking up so much of the eolonrisg nottnas
alcohol does (p. 966) ; but they are better adapted for the preparation of qainiBetbtt
of cinchonine, which is but sparingly soluble in either of them. (See QGDnxx.)

Properties. — Cinchonine deposited by slow eyi^ration of its alcobolie sobitis&,
forms colourless, shining, quadrilateral prisms or needles, which are anhydnnK. It
has a peculiar bitter taste, which howerer is slow in developing itself oo aceoutcf
the sparing solubility of the substance. It is insoluble in oold water, and leqninilbr
solution 2600 parts of boiling water. In alcohol it is much less soluble than qnioiM,
the solubility increasing however with the strength of the alcohol and thetempentm
According to Duflos, strong alcohol dissolves 3 per cent of its weight of cmchoiuBi
It is insoluble in ether, slightly soluble in chloroform, volatile oils and fixed oils.

The solutions of cinchonine have an alkaline reaction, and deflect the phoe d
polarisation of a luminous rav strongly to the right An alcoholic solution aodnhtcd
with sulphuric acid gives [a] ■- + 190*40^ ; acids produce a temporaiy decrene of
the rotatory power. Cinchonine possesses febrifuge properties, but in a maeh knv
degree than quinine.

The following are the mean results of the analyses of cinchonine by various chemists

CaiculaiioH. Llebiff. RegnaulL OerhardC. HlatArett. LagrcoL

C» . .240 77-98 70116 7678 7763 77-97 ni9

N«« . . S4 7-79 7-37 769 7*98 776 7«

Na . . 28 909 887 9'45 — — -

O . . 16 R19 7-40 6*08 _ _ -

C'0H«»N«O 308 100-00 100 00 100 00

Laurent assigned to cinchonine the formula C"H**N*0. According to SchfitxfD*
berger (Jahrouber. d. Chem. 1858, p. 372J, the name cinchonine is applied to ba«
of different constitution ; one sample whidi ne analysed yielded numbers agreeiiig Tith
the formula C»H«N«0«.

Cinchonine melts at 165^ C. forming a colourless liquid, which becomes cryBtalliBe
on cooling ; at a higher temperature, it partly sublimes, exhaling an aromatie odov.
According to Hlasiwetz, cinchonine may be sublimed in hydrogen or ammonu g»
in the form of shining prisms more than an inch long. Heated with sulphffic w
and peroxide of lead^ it yields a red substance, cinchonetine, which has not bea
examined (Marchand, J. Chim. m^d. x. 362). Other oxidising sgents, ^.y.ni^
acid, permanganate of potassium, and a mixture of sulphuric acid and peroxide of
manganese, do not exert much action upon it; neither is it decomposed in a definite
manner by emulsin (Hlasiwetz). With nitrous acid, it forms a base contaiuiiig
1 at oxygen more than cinchonine, and isomeric with quinine, but approaching mow
nearly to cinchonine in its properties (Schiitzenberger, Jahresber. d. Chem. 18^
p. 371). It dissolves in fuming sulphuric acid, yielding sulpho-cinchonicscia,
which forms a soluble barium-salt, C«H»BaN*O.SO* (Schiitzenberger.) Withc**^
rine and bromine, it forms several substitution-bases, as well as a resinous nih8t«a»
"With chlorine and amTnonia, it does not exhibit the green colouring which is dint'
teristic of quinine. "With iodtTie and iodated potassic iodide it behaves like quinine.
Distilled with hydrate of potassium, it yields chinoline, together with seTersl other
volatile bases (p. 869).

Beta'Cinchonine.Sehw&he (J. Pharm. [3] xxxviii. 389), has obtained ta
commercial quino'idine (a product of the alteration by heat of quinine, cinchonine, st
fbund in the mother-liquors of the preparation of sulphate of quinine), an aJJaim
isomeric with cinchonine, but differing from it in many properties. This ^-cinchonine
is contained in the portion of quino'idine which is sparingly soluble in alcohol ; Mid the
sulphate is obtainea therefrom by dissolving the substance in dilute acid, P'^^P^^
with ammonia, treating the washed precipitate with cold alcohol of specific gravity 0'84^
again dissolving it in dilute sulphuric acid, and crystallising. The base sepantw
from the sulphate crystallises from boiling alcohol by spontaneous eTsporaboD u
rhombic combinations, ooP. oof oo. oP ( ooP : ooP » 119<^). The crj^stallisfd »>
well as the precipitated base is anhydrous, and melts at 160® C. /5-cinchonine tf
more soluble in water, alcohol, ether, and chloroform than ordinal^ a-rinchonine-
The following table nves the quantities of these several solvents required to diaolte
1 pt. of a and fi cinchonine, as determined by Schwabe.

m- Cinchonine, fi-dndumlne.

Water, cold insoluble insoluble

Water, hot 2500 scarc^y soluble

Alcohol, cold .... — 173

Alcohol, hot 30 43

Ether insoluble 378

Chloroform 40 268

CINCHONINE. 975

The alcoholic solation of /S-cinelionine is dextro-rotatoij.
' /S-cinchonine is precipitated white from the solutions of its salts by caustic or caiv

k bonated allcalis, the precipitate being somewhat soluble in excess of the reagent, and

t disappearing when shaken up with ether. A solation of the base containing tartaric

1 acid IS not precipitated hj acid carbonate of sodium. A neutral solution of the sul-

L phate mixed with chlorine-water and then carefuUj with ammonia^ exhibits a yellow

I colour. With feirocyanide of potassium and chlorine, a red colouring is produced,

i. turning green on addition of ammonia. Quinine-solutions thus treated, exhibit a dark

I red colour ; ordinary dnchonine and quinidine, wine-yellow.

t Salts of Cinchonine, — Cinchonine dissolres readily in acids. The salts are

1 bitter and are Tezy much like the corresponding salts of qmnine, but for the most part

! more soluble in water and in alcohoL Ordinary cinchonine forms both acid and

t neutral salts ; jS-cinchonine apparently only neutral salts.

c AcsTATi OF CiNCHONiNB. — A solutiou of cinchouine in acetic add always exhibits

L an acid reaction, howeyer great may be the excess of cinchonine contained in it ; but

if concentrated by heat, it deposits on cooling, small spcuringly soluble crystals, which
c exhibit no acid reaction after washing. If the liquid be slowlj evaporated to dryness,

a gummy mass is obtained, which is decomposed by water into an acid salt which
' diwolTes and a neutral salt which remains at the bottom. (Pelletier and Ca-

ventou.)
Acetate of fi-Cinehonine ibrms right-angled four-aided prisms, like those of the

sulphate and hydrochlorate. (Schwabe.)
Absbnatb of CuroHONiNB. — Very soluble ; difficult to crystallise.
|. Caxbojxatb of Cinchoninb. — Cinchonine dissolves in aqueous carbonic acid more

easily than in pure water ; but the solution does not yield a crystallised carbonate.
j Chloiia,tb of CiNCHONiNS, C*H'*N*0.HC10".— White bulky crystalline tufts ; melts

at a gentle heaty and decomposes with explosion at a higher temperature. (Serullas.)
f Chbokatb of Cinchonine. -^Obtained as a yellow amorphous precipitate, adhering

I to the ^lass, but becoming crystalline after a while when a solution of sulphate of

I cinchonine is mixed with acid chromate of potassium. It is decomposed by water and

, alcohoL (Elderhorst.)

I Ctantjr^te of Cinchoninb. — A solution of cinchonine in a boiling saturated so-

i lution of cyanuric acid deposits rhomboi'dal prisms, sparingly soluble in water, inso-

\f luble in alcohol and ether. The salt gives off 17'79 per cent, water at 100^ C; and

; • decomposed at 200^, exhaling an odour of bitter almonds. (Elderhorst)

Fesbictanatb of Cinchoninb, C"H**NK).3HCy.Fe*Cy' + 2aq. — Oran^yellow pre-
{ eipitate, obtained by mixing the aqueous solutions of hydrochlorate of cinchonine and

^ ferricyanide of potassium. After drying in the air, it undergoes no iQteration at 100^ C.

( (D o 1 1 f u s , Ann. Ch. Pharm. )xv. 224.)

Febboctanatb of Cinchoninb, C*H'*NH).4HCy.2FeCy + 2aq. — ^Lemon-yellow pre-
cipitate produced on mixing the alcoholic solutions of cinchonine and ferrocvanic acid.
It is very sparingly soluble in alchol, and when heated, either alone, or with water, is
decomposed, yielding hydrocyanic acid and a blue residue (Dollfus). Ferrocy^
anate of Cinchonine is sparingly soluble and crystallisable. (Schwabe. )

FoRUATB OF Cinchoninb. — Very soluble; crystallises from a syrupy solution in
silky needles.

Gaxlotannatb of Cinchonine. — Yellowish-white powder, very little soluble in cold,
more soluble in boiling water, whence it separatee in transparent grains on cooling.

HiPPUHATB OF Cinchoninb. — UncrystalUsable.

Htdeochlosatb OF Cinchoninb. — Theneutral salt, C**H"N'0.HC1, obtained by
exactly saturating cinchonine with weak hydrochloric acid ; ciystallises in transparent
shining rhomboi'dal prisms ; melts at 100** C. ; dissolves easily in water and in alcohol,
but is insoluble in ether. The aqueous solution possesses dextro-rotatory power;
[a]» +139*50^ (Bouchardat). When subjected to electrolysis, it yields chloro-
cinchonine, together with chlorine, oxygen, and hydrogen. (Babo.)

Hydrochlorate of Cinchonine, C**H'*N*0.HC1 + 2aq., crystallises apparently
in rhombic combinations, ooP. ooPoo.oP, in which ooP: ooPm1264^. It dissolves
in 22 pts. of cold, 3*2 pts. of hot water ; in 1 pt. of cold, } pt. of boiling alcohol, and
in 660 pts. of ether.

Acid hydrochlorate of cinchonine, C"H**NK).2H"C1, is produced by exposing
cinchonine to hydrochloric acid gas, and is obtained crystallised by pouring a slight
excess of the acid on cinchonine, and dissolving the product in a mixture of water and
alcohoL The solution left to evaporate very slowly in an unclosed bottle, deposits
very well-defined rhombic tabular crystals, having the acute angles truncated,
ooP : ooP« 101^; ion : oP » 137 to ISS^'. It is vexy soluble in water, rather
less in alcohol : reddens litmus. The solution is dextro-rotatory.

976 CmCHOMINE*

Chlorine puwd into a solntkni of tiiis nlt^ Conns a depoot of acid lajdrodJoiate of
dichlorocincnonine.

Ckloromereuraitt C**H**NK).2^HGL]^;C1).— On mixing a aolvtion cianAaaM
in ftiong alcohol containing hjdxoduMie add with a addition of macarie dhlondB afao
in strong alcohol, the miztoze eolidilles after airiiila to a maas of smaU needlei^ neniy
ineolnble in cold water, ofdinair alcohol, and ether, moderalelj aohiMe in boiliig
water, and in wann alcohol, easilj eohihle in itxong hjdiodilarie acid. Tine aalt aaj
be dried at lOO^ C. without alteration.

Cklorovlatinate, 0"H*«NK).2(HCLPtCP).—Ligfat yellow pne^tate, olitainedW
adding dichloride of platinum to a wdntion of acid hjdrodilonte of cindMHune. Wim
an alcoholic eolation of cinchonine containing hydneUoiie add, the ptedpitate ia 07*-
taUine and neaiij whiter and diasolTee after priMonged boiling with water, the aolntMB
ae it boils, depositing, fizsta whitish polTemlent pcedpitate^ afterwards beantifalaTstifa
of a deep orange cdonr. The salt contains, aocordingto Hladweti^ 33*1 per cenLQ
8-6 H, and 27*36 Ft, the fonnnla requiring 330 C, 8'3 H, and 2736 Pt.

CkloroflatinaU of 3^t »c Aon ttt^C**H*'N'O.HCLPtCP,er78taD]se0 on mizii^
the akohohc solutions of its component salts, in rhombic combinstiona, ooP . oo jl^ ob . oP,
in which odP : ooP ■■ 119 (approzimateljr). (Schwabe.)

Htdboctahatb of 3-G^lCROllI2a^ obtained bj ptedpitation with gnsnide of pola^
sinm, is smoiphous, anhydrous, insoluble in water and alcohol (Schwabe.)

Htdbovluatb of CnfCHOinm, (7*H"KK).2HF. — A solution of recently prsedpitated
dnchonine in dilute hydrofluoric acid, depodts colouriess prisms when ooncentraf ed
The salt crystallises esnly from dilute aliDohol in ihomboidal prisms terminated by
octahedral mces. After drying at mean temperature^ it gives off 2*8 per eeok water

at 166^0.; at a high temperature, it acquires a fine purple tint, yields a zed anbliaiate^
gives off hydrofluoric and, and becomes carbonised.

Htdbxcdatb op CiHCifoinicn, G*H**NK).HI-f aq. (Begnanlt.) — ^Kndi leea solnUe
than the hydrochlorate. CiystaUises easily in nacreous needles. Its aolntion is pre-
dpitated by mercuric chloride snd cyanide. Sydriodate 0/ fi^inckonine ia euily
Bolnble in water and in alcohoL (Schwabe.)

Htposuuphatb of CntcHoimrB. — Crystallisable ; resembles the qoiuine-Balt (;.«.)

HTFOsnuvrri of GnfCHomiiB. — Obtained by j«edpitation in small needles ; ray
sparingly soluble in cold water. (Winckler.)

loDATS OF CmcHONnai, C**H*<NK>.HIO* (at 105<»C.).— Long nSkf fffarea^ voy
soluble in water and alcohoL Explodes with violence at 120^ C. *^

NiTBATB OF CnrcHoinNB, C»H'«N*O.HNO* -1- aq. (Regnault)— Obtained by die-
Bolying cinchonine in dilute nitric acid If the solution is rather concmtrated, pait
of the nitrate separates in oDy globules, which, if covered with water, az« conTcrCed
in a few days into a group of oblique rectangular prisms, yery soluble in water. The
solution IB dextro-rotatory, [a] «- + 172*48^ (BouchardatX When deeonqwaed
by the dectro-current (from six Bunsen's cells), it gives off oxygen at the pontiva
pole, mixed after a while with carbonic add and oxides of nitrogen, and at the nentive
pole, a mixture of hydrogen and nitrogen containins a little ammonia ; in the nqnid
into which the negatire pole dipped, a resinous siSxrtance was depodted, and the
solution decanted therefrom and duitilled with potash, yielded ammonia and ofl j di«pa
of chinoline. (Babo, J. pr. Chem. Ixxii 73.)

Nitrate of 0-einekonine crTstaUises slowly, by spontaneous evaporation, in
monoclinic or triclinic crystals, which are moderately soluble in water and alcohol, and
do not effloresce. (Schwabe.)

OxAiATBs OP Onxcaovun. — ^The neutral oxalate is a white predpitate, insoluble
in cold, slightiy soluble in boiUng water, very soluble in alcohol, especially if hot, and
in oxalate of ammonium. The acid oxalate is much more solul^ than the nentxal
salt 0«a/a^« o/ZS-ctncrAontntf is crystallisable. (Schwabe.)

OxALUBATa OF CiN OHONiKB. — Obtained by saturating a boiling solution of parabanie
acid with excess of cinchonine. The solution dries up to a yellowish transparent mase^
which whitens a little as it sssumes the crystalline form. When boiled with hydro-
chloric acid, it dissolves, producing oxalic add (Elder horst)

PsBCHLOBAn OF CxircHoxiiCB, C»H*<NH).HC10* + sq.— Obtained by decomposing
sulphate of cinchonine with perchlorate of barium. Large rhomboidal prisms, hsTing
a strong lustre, and exhibiting a fine blue and yellow dichroism, even in very dilate
solutions. Very soluble in water and alcohoL Slelts and gives off its water st 160<* C.
and decomposes with explosion at a higher temperature. The sidt dried at 30^ GL
gives off 3-67 per cent water at 160^ (Boedeker, jun. Ann. Ch. Pharm. Ixxi. 69).
According to Dauber (ibid, 66), the crystals belong to the didinic system of Nan-
mann (see Cbtstalloobafkt), being rhomboidal prisms of 125° 47' and 64<> 13' witli
perpendicular truncation of the acute edges.

CINCHONINE, 977

Pbsiodatb of CiNOHOinNB. — ^Very nxurtable priflmfl, obtained like the perchlorate.
According to Langlois, periodic acid ozidiseB cincbonine more rapidly than qninine.

'Phosphate of CnfCHovora. — ^Veiy soluble. A solution of cinchonine in phosphoric
acid, yields by eraporationf sometimes radimentaiy dystals, bat more generally amox^
phons, transparent plates, which gradually become aystalline by contact with water.

FhotpkatB of fi^inchonine forms oystals nearly a line in length, and appa-
rently oblique-angled. (Schwabe.)

PiCRATi OF CmcHOMiHB. — ^YeUowpulvemlent precipitata, nearly insoluble in water,
rezy soluble in aloohoL

QuiKATB OF CiNcaoNiinL — A strong aqueous solution of cinchonine in quinic add
deposits, when left at rest, sometimes sillnr needles, sometimes a mammellated mass of
small granules. The salt dissolres in half its weight of water at 25^ C. : it contains
water of aystaUisation. From a solution«4n warm alcohol, it crystallises on cooling in
colourless, shining, short, compressed prisms, apparently unadterable either by ex-
posure to the air or by a moderate heat, but becoming completely opaque in course of
time. Water dissolves them reiy readily, but with partial decomposition. Their
aqueous solution turns reddened litmus blue, but the alcoholic liquid from which they
were deposited, turns blue litmus red.

SuLPHJLTBS OF CmcHOiONB.— The neutral tulphate, 2C^H**NK>.H^SO^ + 2aq., is
obtained by exactly saturating cinchonine with dilute sul{>huric acid. It forms rhombic
prisms of 83^ and 97^, generally very short, and haTing their ends truncated or
beyelled : deavable parallel to the prismatic faces ; sometimes hemitropic. They are
hard, transparent, and hare a -vitreous lustre ; permanent in the air ; melt a little
above 100^ C. and give off their 2 at water between 100^ and 120<>. They dissolve at
mean temperatures in 64 pts. water, 6 J pte. alooholof specific gravity 0*86, and 11^ pts.
absolute alcohol; insoluble in ether (Baup). It is but slightly decomposed by the
electric current

Sulphate of cinchonine becomes phosphorescent at 100^ C. like sulphate of quinine.
At higher temperatures, it melts and then decomposes, yielding a resinous matter of a
fine red colour. But if the salt be previously mixed with a little water and sulphuric
acid, it remains liquid at a low temperature, even after all the water has been driven
off; and if kept in this state for three or four hours at 120^ to 130^0. it is completely
transformed into sulphate of cinchonicine, only a very small quantity of colouring
matter beipg then produced. (Pasteur, p. 969.)

Sulphate of fi-cinchonine, 2C"H"N'0.H*S0* + 2 aq.—Ciystallises in rhombic
combinations ooP.ooPoo.oP, in which od P : oo Pb« 136^. It dissolves in 76 pts. of
cold, and 14 pts. of hot water; in 13*6*pts. of cold, and 1*6 pts. hot alcohol of 80 per
cent., and is insoluble in ether. The dilute aqueous solution is strongly iridiscent
(Schwabe.)

Acid Sulphate of Cinchonine, CJ"H**NK).H^O* + 8 aq.— Bj adding sulphuric
acid to the neutral sulphate, and evaporating till a slight pellide is formed, the add
salt is obtained in rhombic octahedrons, often having some of their edffes or summits
modified, and cleaving very easily, at right angles to the axis, in weU-defined shining
laminse. It is permanent in the air at ordinary temperatures, but effloresces in very
dry air or if slightly warmed. When heated, it gives off 11'73 per cent, water ■« 3 at
At 14^ C, 100 pts. of the salt [? anhydrous or hydrated], dissolve in 46 pts. water, in
90 pts. of alcohol, of specific gravity 0*86, and in 100 pts. of absolute alcohol : it is
insoluble in ether. (Banp, Ann. Ch. Phys. [3] xxviL 828.)

SxTLFHOOTANATB OF Cdtohonimb, C'*HVNH)MCj8, Gmtallises in brilliant anhy-
drous needles (Dollfus). Sulphocyanate o//3-otn0AOittn0isalsoczystallisable.
(Schwabe.)

Tabtratbs of (^XNCHOKiinL (Pasteur, Ann. Ch. Phvs. [31 xxxviii. 466, 469. —
Arppe, J. pr. Chem. liiL 331.)— These salts, neutnl and ado, dextro- or kevo-rota-
toiy, are prepared by dissolving cinchonine in tJie proper proportions in the two modi-
fications of tartaric add.

a. Neutral, 2C~H"N*O.C*HK)*-i-2aq.— Large needles grouped in bundles, spar-
ingly soluble in water, and giving off their ctystaUisation-water, 4*6 per cent, between
100° and 120<> C. (Arppe^

3. Acid Tartrates,'-'!!)!^ dextro-rotatory $alt, C"*H**N«0.C*HH)« + 4aq., forms
nacreous shining crystals grouped in radiate stars. They belong to the trimetric
system, and are often hemihedml. Observed combination, oo P . j^ oo . P. Inclination of

faces, 00 P : 00 P« 133® 20' (nearly); j^ co : J» oo «r 127*» 40'; ? : t oo - 1610 13'. The

faces 00 P are longitudinally striated. It gives off its water (13*76—14*0 per cent ;
calculation, 13*68 per cent) at 100® CL, and at 120®, assumes a red colour and begina
Vol. I. 3 R

978 CINCHONINE.

to melt It dissolves but sparingly in cold, much more eaafly in hot water, still mm
in alcohol ; the solution is neutral to test-paper.

A solution containing twice the quantity of tartaric acid required to form this alt,
deposits at first, another acid tartrate in transparent well-defined crystals.

lAtvo-rotatory acid tartrate, C*H«*N*O.C«H«0«+aq.— This salt gives off its
water » 4*58 per cent (calc. 378), at 100^ C. It is very spaiin^y soluble in alcohol
and in water; the alcoholic solution is neutral, the aqueous eolation acid to test-paper.

If a great excess of acid is used in the preparation, another acid tartrate is obtab«d
crystallised in brilliant tufts, composed of ym slender needles, and very difleicDt is
appearance from the second dextio-rotatoiy acid tartrate aboTO-menfioned. (Pasteur.)

Uratb of CmcHOKno, C=»H**N*O.C*H«N*0« + 4 aq.— Obtained by boiling uric add
with cinchonine recently precipitated and diffused through a lai^ge quantity of water.
The liquid filtered at the boiling heat, deposits long prisms sparingly soluble in vatez;
boiling alcohol, and ether. On heating the salt to 100° C. or leaving it to evaponte
over oil of vitriol, it becomes opaque, and finally assumes a sulphur-yellow ooloin',
giving off 12*49 per cent (calc. 4 at » 13*73 per cent). During the desiocatioo, it ii
in a state of constant agitation, and is finally converted into a crystalline povde^
probably differing in form from the hydrated crystals. (£lderhor8t,/iMr. at)

Srominated, Chlorinated, and lodated DerivativeB of Omehonme.

BBOMOCiifCHOiriNS, C*H"^rl^O. (Laurent, Ann. Ch. Phys. [3] xxiv. 301)
— When bromine is poured upon moist acid hydrochlorate of cinchonine, a product is
obtained, which, when freed from excess of bromine by washing with a little alcohol, is
a mixture of acid hydrobromate or hydrochlorate of bromocinchonine and seBtjiubrooo*
cinchonine. On treating it with boiling alcohol, the former of these salts disrolTM,
while the latter is nearly insoluble ; and on adding ammonia to the decanted sohtioii,
boiling to expel part of the alcohol, and leaving it to cool, bromooinchonine is depo-
sited in laminae, which may be purified by recrystallisation.

The acid hydrochlorate, C*H"BrN«0.2HCl, crystalliaes in the same form as the
corresponding siolt of cinchonine. The chloroplatinate, C*H**BrN*0.2(HCLPtCPi
is a pale yellow powder, containing at 50^ C. 24*2 per cent platinum (calc 24*7i>).

SasQUTBROMOciNCHOviNB, C»H"'»Br»*N*0. (Laurent, loc. (»<.)— When tts

Sulvemlent residue, insoluble in boiling alcohol, obtained in the preparation jut
escribed, is boiled with water, and ammonia added, a white bulky precipitate of sesqai-
bromocinchonine is formed, which, after washing and drying, dissolves in boiling ueo-
hoi, and crystallises therefrom in slender needles. It is slightly bitter ; its aloohobe
solution turns reddened litmus blue. It melta when heated, afterwards blackens vith
intumescence. It gives by analysis 55*45 per cent G, 5*18 H, and 28*3 Br, the fbaaoii
requiring 56*27 C, 5*27 H, and 28*13 B^.
The acid Ay^irocA/ora^e, C*'H»*Br»"»N«0.2HCl, forms rhombic tables, inwhiA

ooP:ooP = 107<*to 108°.

The hydrohromochlorate, C»H«'«Br>'»N«O.B[ClHBr, is obtained by ponnng
bromine on hydrochlorate of cinchonine; boiling with alcohol as above, to remove hj-
drochlorate of bromocinchonine ; again pouring alcohol (m the residual salt ; ^^^'
adding ammonia, which dissolves it immediately; then adding excess of hydiochknc
acid to the solution, and leaving it to cool. The salt is then deposited in smidl rhomhie
tables, in which oo P : oo P - 107° to 108®.

The choroflatinate, C»H»»Br«-*N»0.2(HCLPta*). is a very pale-yeUowpreop*
tate, containing at 100° C. 23*0 per cent platinum ; by calculation, 23*5.

DiBBOMOOiNCHONiNB, C*H«Br*N»0. (Laurent, Compt chim. 1849,p.5lVh"
Bromine in excess is poured on acid hydrochlorate of cinchonine, to which a little vvtf
has been added ; the product is heated when the action is over, to complete the xx^
mination of the cinchonine, and expel excess of bromine ; water is then poured np^
it ; the liquid is boiled and filtered ; alcohol is added to the aqueous filtrate, beatagaiB
applied, and the solution is neutralised with ammonia. On cooling, it deposits dibrono*
cinchonine in colourless laminae, with nacreous reflexion. .,

Dibromocinchonine is insoluble in water, sparingly soluble in boiling fllcohoL A
about 200° C. it sweUs, blackens, and yields a substance which dissolves f'^v "
potash, and is separated therefrom by acids in brown fiakea Dibromocinchonine^^
by analysis 51*20 per cent C, 4*4 H, and 34*00 Br, the formula requiring 5H»^
4*70 H, and 34*19 Br. A solution which had been left for some days in •» «P^
vessel, deposited rectangular octahedrons, containing 4*2 per cent -» 1 «^ ^^
crystallisation. ..,

Theacirf hydrochlorate, C»H«Br«N*0.2HCl, obtained by treating the base ^
hydrochloric add, is sparingly soluble in water, and separates from a boilioiP ^^p^
on cooling, in rhombic tablets, having their four acute angles truncated; ooF : * '^*

CINCHONINE. 979

1 04^ to 105^ : j^oo : oP »137. Its solution deflects the plane of polarisation to the
right.

DiOHLOBOCiKCHONiNB,C"H"Cl'N*0. (Laurcnt, Ann. CLPhys. [3] xxiv. 302.)
— ^The acid hjdxochlorate of this base is formed bypassing chlorine into a hot concen-
trated solution of acid h^drochlorate of cinchonine ; and on adding ammonia to a
solution of thia salt in boiling water, the base is precipitated as a lipht flocculent mass,
which ayBtallises from boiling alcohol in microscopic needles, yielding by analysis
18*9 per cent chlorine (calc 18*83).

The aoid hydrochlorate^ C*H^C1'N^0.2HC1, is sparingly soluble in water, and
requires 60 pts. of alcohol to dissolve it : the solution is dextro-rotatoiy. The salt
dystallises in rhombic tables isomorphous with the crystals of acid hydrochlorate of
cinchonine, oo P : oo P=106°; Poo : oP = 136o 30' to 137*^ 30'.

The chloroplatinate, C •H«a«N«0.2(HCLPtCl»),i8 apaleyellowpowder, yielding
at 100^, 2500 per cent, platinum (calc. 25'06).

The aoid hydrohromaie, C»H«CPN«0.2HBr, obtained by treating the base with
hydrobromic acid,i8 sparingly soluble, and cirstalliBes in brilliant laminse, haying sensibly
the same angles as those of the acid hydrochlorate, bat presenting a different appearance,
inasmuch as tiie modii^ing faces are considerably deyeloped, so that the rhombic tablet
is transformed into a six-sided prism ; oo P : oo P b 104^ ; P oo : oP « 137°. The salt
has the same composition as the acid hydrochlorate of dibromodnchonine, but differs
from it in giving with nitrate of silver a precipitate of bromide of silver, whereas the
latter yiel£ a precipitate of chloride.

The nitrate is sparingly soluble in water, and crystallises in small elongated tetra-
hedrons, formed of four equal scalene triangles, and having their opposite edges trun-
cated.

IoDOCiKCHOifiNi^2C»H«N«0.P(?) (Pelletier, Ann.Ch. Phys. [2] Ixiii 181.)—
When cinchonine is triturated with about half its weight of iodine, and the product is
treated with alcohol of 36 per cent, the whole dissolves, and on leaving the solution to
evaporate, it first deposits the so-called iodocinchonine in saffiron-coloured plates, after-
warcls crystalline nodules of h^driodate of cinchonine. On treating the whq^e with
boiling water, the hydriodate dissolves, and the iodocinchonine separates in the melted
state.

Iodocinchonine has a deep saSron-yellow colour when seen in mass ; its powder is
lighter. It has a slightly bitter taste. When heated, it softens at 25° C. but does
not enter into complete fusion till heated to 80°. It is insoluble in cold water, very
soluble in boiling water, soluble in alcohol and ether. It gave by analysis 28*83 per
cent iodine (calc. 29*03).

•Iodocinchonine may be decomposed by the successive action of acid and alkaline
solutions. It is likewise decomposed by nitrate of silver. (Pelletier.)

If the preceding formula be correct, the compound is not iodocinchonine, but iodide
of cinchonine.

Sulphate of Iodocinchonine, (W. B. Herapath, Chem. Soc Qu. J. zi 151.) —
Cinchonine treated with iodine and strong sulphuric acid, jjrields a crystalline salt, which
resembles the corresponding quinine-compound in its action on light It crystallises in
long needles, which appear deep purple-red by transmitted, and dark purple-blue by re-
flected light ; their lainin» appear lenion-yellow by transmitted light, and if two such
thin plates be superposed in such a maimer that their longest dimensions may cross
one another at right angles, the system is perfectly impervious to light the two plates
acting in fact like two tourmalines with their axes crossed. (For further details re-
lating to these properties, see Sulphate of Iodoquininb, under Quhonb). The salt
disscuves easily in strong boiling alcohol, and crystallises therefrom; sparingly in
weak alcohol, and scarcely at all m water, ether, and chloroform. Herapath assigns
to it the formubi C*»H"N*0«I«.H«SO* + 3aq., which is very improbable.

Sulphate of Io€h^$^nchonine is obtained in indistinct crystals on adding a warm
solution of 3 pts. iodine in 115 pts. alcohol to a solution of 10 pts. of sulphate of /3-cin-
chonine in 144 pts. acetic add, and 12 pts. dilute sulphuric acid. (Schwabe.)

Derivatives of Cinchonine containing Organio Radidee,

BBWzoTL-ciKCHONiNa, C*'H"N»0 « C^H?»(C'H»0)N«0. (Sohiitzenberger,
Ann. Ch. Pharm. cviii. 351.) — Dry cinchonine dissolves with rise of temperature in
chloride of benzoyl, and the mixture, if heated for a few seconds, solidifies to a crystalline
mass of hydrochlorate of benzoyl-cinchonine. This salt dissolves readily in water, and
the solution, quickly decanted fVom undissolved chloride of benzovl, yields with ammonia
a white glutinous precipitate of benzovl-cinchonine, which hardens in the cold. It is
tasteless and uncrystallisabley insoluble in water, but dissolves in all proportions in

Sb 2

980 CINCHOVATINE — CINXAMEIN.

alcoliol and ether. Its salts are easily soluble in water. The i^roeilaraie is
C"H»N«O.Ha ; the ehloroplaiinaie C"H*NK>*. 2(HCa.Pta*).

MBTHTL-ciNCHOinira, C«»H"NK)s=C»H«(CH»)N*0. (Stahlschmidt^ A»ti_ Ch.
Fharm. xc. 218.)— The hydriodaU of this base, C'iH*'N*O.HI, is produced by the
action of iodide of methjf on pulverised cinchonine. It dissolres easflj in boiling
water, and separates in fine needles on cooling. It is not attacked by iodide €€
methyl when heated therewith to 100^ C. in a sealed tube : hence dnchonine appesrs to
contain but 1 at. of hydrogen replaceable by an alcohol-radide.

The iodide treated with oxide of silver, yields a solution of the base, which, when
quickly evaporated over the water-bath, leaves a brown crystalline mass, from which,
when dissolved in water, brown oily drops separate. The aqueous solution pzedpitstei
the salts of sesquioxides.

The salts of methyl-cinchonine are very soluble in water and in alcohol, And difficult
to crystallise.

The ehloroplaiinaie, C"H»N'0.2(HCUPta«), yields when dried at 100«>C., 26-70 —
2677 per cent platinum, the formula requiring 26*93.

CIWCBOVJkTZVa. Syn. with ABicnnk (p. Z67).

Protosnlphide of mercuiy. (See Mxscust. )

r. Cinnamaie of Benzyl C"ff*0* - ^*^^|o. (Plan tain our,

Ann. Ch. Pharm.xxvii. 329; xxx. 241. — ^FrAmy, Ann. Ch. Phys. Ixx. 189. — ^FL De-
ville, Ann. Ch. Pharm. Ixxiv. 230. — E. Kopp, Compt chim. 1850, p. 410. —

Scharling, Ann. Ch. Pharm. xcvii. 184.— Gm. xiii. 283 Gerh. iii. 404.) — This

compound was discovered by Plantamour (1838), who obtained it from balsam of
Peru, in which, according to Simon, it exists ready formed ; according to Fr&my and
Deville, it exists also in small quantity in Tolu balsam. According to Schariin^
cinnamic acid dissolved in p'sruvin (a mixture of benzylic alcohol and toluene) fonna a
liquid, which, when saturatetl with hydrochloric acid, yields to boiling water a nentnl
oil resembling cinnamein.

Preparation. — Balsam of Peru is saponified by agitation with excess of caostie
potash, and the solid soap dissolved in water : the solution on being warmed, sepantes
after a few minutes into two layers, and the upper, which is oily, is to be repeatedly
washed with water, till the oil exhibits a fJEunt reddish-yellow colour. The residual
water is evaporated over the water-bath ; the oil dissolved in warm alcohol and evapo-
rated ; and this treatment repeated as long as resin separates out on evaporatioo.
(Plantamour). — 2. Balsam of Peru dissolved in alcohol of 36°, is treated with alco-
holic potash, whereby a compound of resin with potash is precipitated ; the solution is
mixed with water ; the cinnamein which separates out in the form of an oil is separated
from the inferior solution of cinnamate of potassium, and dissolved in £reehly*icetified
rock-oil, whereby resin is removed ; the rock-oil is then evaporated, and the residual
oil placed in a vacuum. Cinnamein thus prepared, still retains styracin in solution, the
quantity varying according to the nature of the balsam. To free it from this im«
purity, it is dissolved in weak alcohol, and cooled for several days below 0^, as long as
a crystalline deposit of styracin continues to form (Fr^my). — 3. Balsam of Pern is
repeatedly boil^ with aqueous carbonate of sodium, and the cinnamate of sodium is
removed by washing, the residue then separating into a resin, and a yellowish-brown
liquid which must be heated to 170° C. on the oil-bath, and distilled in steam heated
to 170°. Colourless, somewhat milky cinnamein then passes over, and is freed from
adhering water by standing for some time in a warm place, over chloride of calcium.
Sometimes, perhaps always, the cinnamein thus prepared contains in solution styracin,
which, after long standing, partially crystallises out (Scharling). Calcined mae-
nesia or oxide of lead also separates cinnamein from balaam of Peru, by combining wiu
the cinnamic acid, and separating resin. (Simon.)

Prowriies.— CinnBmeia is a feebly coloured or colourless, strongly r6&aeting,neatral
oil, which remains liquid when cooled to — 12° or —15° C. for several days. It boili
at 305°, and distils without decomposition (Plantamour); between 340° and 350°,
with partial decomposition (Deville, Fr^my). It has a feeble pleasant odour. Its
taste is sharp and aromatic, recalling that of fat. It makes grease spots on paper.
Specific gravity, 1098 at 14° ; 10925 at 25° (Scharling). It is nearly insoluble in
water, but dissolves in alcohol and ether.

Cinnamein contains, according to Scharling's analysis, 79*18 to 79*24 per cent. C,
6-56 to 6-03 H, and 14*26 to 13*72 0, agreeing nearly with the preceding formula,
which requires 80*62 C, 588 H, and 13*45 0. — When kept under water for some time,
it yields a crystalline substance of the same composition, metacinnamein, whidi melts
between 12 and 15° C. sometimes resolidifies alter cooling and standing, but after solu-
tion in boiling alcohol cannot again be obtained in the oystalline form. (Scharling.)

CINNAMENE. 981

Omnamein slowly abflorbs moist oxygen (Fr^m j). When exposed for vears to air
and Iwht^ it acqnires a rancid odour and acid reaction. CrystalliBed cinnamein preserved
in a glass yessel for a year melted to a viscoiis mass, and in another year solidified to a
transparent amoiphons mass (Scharling). Cinnamein is partially decomposed by dis-
tillation, leaying a small quantity of tar, and yielding a distillate differing in compo-
sition from the original substance.

It is resinised by strong mdphurio acid (Fr^my. It dowly absorbs chlorine^ more
easily when heated, becoming at the same time coloured and tiiickened, and when dis-
tilled, idtimately yields chloride of benzoyl together with an oil (Fr^my). Nitric
acid acts briskly on cinnamein when heated, forming a yellow resin and a large
quantity of bitter almond oiL Peroxide of lead acts in a similar manner (Fr^my).
Cinnamein forms a crystalline compound with aTMtwnia (Plan tamour). Mixed with
sulphide of carbon and powdered hydrate of potassium, it forms a saline mass con-
taining xanthate of potassium (Scharling). Rapidly heated with yery concentrated
potash-ley, or melted with hydrate of potash, it giyes off hydrogen, and passes into
cinnamate (and benzoate) of potassium (Fr^my^ Treated wi& yery concentrated
potash-ley in the cold, or with alcoholic potash, it is completely re8<^yea, in 24 hours,
without disengagement of gas or absorption of oxygen^ into benzylic alcohol and cin-
namate of potassium : C*«H>«0* + KuO - C'H"0 + C»H»KO«. By the continued
action of the potash, the benzylic alcohol may be converted into benzylene. (C'H*,)

FlantaxAour, by treating cinnamein with strong alcoholic potash, obtained, together
with cinnamic acid, an acid which he designated as carbooenzoio or myroxylic acid ;
probably impure benzoie-acid resulting from the decomposition of cinnamic add under
the influence of potash (p. 984).

CSHVAanara. C^*. dnnamol, Siyrol. Volatile Oil of Liquid Storax, (Bo-
nastre, J. Pharm. xviL 338. — D'Arcet, Aim. Ch. Phys. Irvi. 110. — Mulder, J. pr.
Chem. xy. 307.— E. Simon, Ann. Ch. Pharm. xxxi. 26o.^-C. Herzog^ Pharm. Centr.
1839, p. 833. — Gerhard t and Cahours, Ann. Ch. Phys^ [3] L 96. — K Kopp, Compt
chim. 1846, p. 87; further, Compt. rend. Uii. 634. — ^Blyth and Hofmann, Ann. Ch.
Pharm. liil 293, 325. — Hem pels, ibid. Gx. 316.— Scharling, ibid. xcviL 184.—
D. Howard, Chem.8oc. Qu. J. xiii. 134 ; Gm. xiiL 1 ; Gerh. ill. 374.) — This compound
is produced by the decomposition of cinnamic acid (^. 981), and is contained in uquid
.storax (p. 982), whence it may be obtained by distillation with water. It was for-
merly supposed that cinnamene obtained from cinnamic acid was not identical, but
only isomeric, with styrol, the volatile oil of storax, because the latter is completely
converted by heat into a solid substance, metastyrol, of the same composition, vmereas
with cinnamene this change had been observed to take place but imperfectly ; but £.
Kopp has lately shown that this transformation takes place quite as completely with
cinnamene as with styrol, an observation which removes the only objection to the sup-
posed identity of the two substances.

Preparation. — a.^ From Cinnamic Acid and the <Oinnamates. Cinnamic acid, when
slowly distilled at its boiling point, is completely resolved into cinnamene and carbonic
anhydride :

C^«0* » C0« + C"H«.

Pure cinnamate of calcium is likewise resolved by dry distillation into cinnamene and
carbonate of calcium (D. toward). Cinnamic acid distilled with excess of lime or
baryta yields a mixture of cinnamene and benzene, which may be separated by rec-
tification.

b. From Storax. — The liquid balsam is distilled in a copper still connected with a
worm-tub, with water containing carbonate of sodium, to retain cinnamic acid ; 3J lbs.
of carbonate of sodium suffice for 10 lbs. of storax. The water which passes over is
milky, and the cinnamene floats on the surface. The quantity obtained varies with the
age of the balsam. Blyth and Hofmann obtained in one operation about 360 grammes
of oil from 20^ kiL of liquid storax, in another not more than 90 grms. from 13J kil.
The oily distilmte is dried over chloride of calcium and rectified. This last operation
requires particular precautions-.. The liquid begins to give off vapour between 100° and
120°C., and at 145° it is in full ebullition, a limpid oil then passing over, and the
thermometer remaining stationary for some time ; suddenly, however,, a considerable
rise takes place, and the thermometer must then be quickly withdrawn from the retort,
for the residue thickens, and on cooling solidifies to a transparent glass, consisting of
metacinnamene or metastyrol. The quantity of this solid residue varies, but it some-
times amounts to half the oil subjected to distillation.

c. Cinnamene may also be obtained from the resin of Pern balsam, by heating that
substance mixed with pumice to dull redness in a retort, and subjecting the oil which
passes over, together with benzoic acid and an aqueous liquid,, to fractional distillation.
The portion which goes over under 175° C, and is lighter than water, is collected, re-
peatedly distilled with potash-solution, allowed to stand several days over piece»of solid

3b 3

982 CINNAMENE.

potash, and then distilled at a temperatare not exceeding 150° G. The distillate is dried
with chloride of calcium, treated with potassium, whereby hydrogen is erolTed, and tlie
fluid part is decanted from the resulting gelatinous precipitate and distilled. The boiling
point then gradually rises to 100° — 14^ C, by wnich time all the cinnamene remains
behind, amounting to { of the liquid employed. (Scharling, Ann. Ch. Pluum. zcriL
184.)

Cinnamene is a Texy mobile colourless oil, having a strong persLstent azomatieodotir,
i«minding of benzene and naphthalene together. It does not solidify at— 20^ C. It
is very volatile, the grease spots which it produces on paper disappearing in a few
seconds. Specific gravity 0*924. Boiling point 14676° C. (Bly th and Hoffmann) ;
146° (£. Kopp). It is neutsral, mixes in all proportions with alcohol and ether, Tola-
tile oils, and sulphide of carbon, and dissolves sulphur and phosphorus.

Cinnamene is not acted upon by potash. With fuming sulphuric add it appears to
form a conjugated acid. If added by drops to fumxng mtric add, it dissolves with
evolution of red vapours ; and water added to the solution throws down a yellow resn,
which, by careful distillation, yields crystals of nitrocinnamene. If boiled with
excess of nitric acid, it yields benzoic or nitrobenzoic acid, according to the streogth
of the nitric acid. Distilled with dilute chromic add, it yields ciystals of nitrobenzoie
acid. With chlorine and bromine, it forms chloride and bromide of dnnamene.

Mbtaoinna-KBUB. MeUutyrol, Draeon^l, — ^This is the solid substance into which
cinnamene or styrol is converted by the action of heat. The conversion takes piaee
readily in a sealed tube heated to 200° C. in an oil-bath. Metacinnamene is likewise
obtained from dragon's blood. When the crude oil produced by the drydistillatioo of
that substance is custilled till the temperature rises to 280° C. a liquid is obtained con-
taining toluene (hydride of benzyl, p. 673), and cinnamene. On distilling this mixture
at a temperature b«low the boiUng pointy till the greater part of the toluene has passed
over, a viscous liquid remains, consisting of metacinnamene, held in solution by a
small quantity of styrol. On pouring this liquid into alcohol, tiie cinnamene dissolves,
while the metacinnamene is precipitated In the form of a soft cdonrless resin like ter-
pentine, which may be washed with alcohol, and then dried in a stove at 160° C.

According to E. Kopp, the transformation of cinnamene into metacinnamene likewisa
takes place spontaneously at ordinary temperatures. This property, joined to the high
refracting power of metacinnamene, suggests the possibihty of using cinnamene for
filling hollow glass lenses or prisms. According to Kovalevsky (Ann. Ch. Phazm.
cxx. 66), metacinnamene exists also, together with cinnamene, in Uquid storax.

Metacinnamene is a colourless, limpid, highly refractive substance, destitute of taste
and odour. At mean temperatures it is hard, and may be cut with a knife ; but it softens
by heat, and toaj then be drawn out into long threads. It is insoluble in water and
alcohol ; ether dissolves it in small quantity, and at the boiling heat transforms it into
a gelatinous mass, which, after drying at 100° C, forms a white spongy substance,
having exactly the composition of stjyrol.

Metacinnamene liquefies when heated in a small retort, and yields by distillation
pure cinnamene, which may be reconverted into metacinnamene by heating to 200° C.
in a sealed tube.

Chlorine and bromine act very slowly on metacinnamene, but ultimately convert it
into chloride and bromide of cinnamene respectively. Strong nUphurie add carbo-
nises it By fusion with hydrate of potassium it is converted into styroL Nitric add of
ordinary strength acts but slightly on metacinnamene, but fuming nitric add dissolves
it easily, with evolution of red vapours ; and if the add has been added in suffident
quanti^, the solution yields with water a precipitate of nitrometaeinnamene.

Compounds and Derivatives of Cinnamene,

Brohtob of CnmAKENE. C*H*Br*. —Produced by the action of bromhie on cinna-
mene. It is insoluble in water, but veiy soluble in alcohol and ether, whence it ciys-
tAllises in needles. Solutions saturated at the boiling heat usually deposit it in the
form of an oU, which remains liquid for a long time, and solidifies suddenly when
agitated. It has a peculiar odour, which is not disagreeable, but exdtes tears. It
melts at 67° C, and often remains liquid, even when cooled to 30° C, but tiie least
agitation causes it to solidify in a crystalline mass. Its boiling point ib above 200° C.
It may be distilled almost wholly without alteration. Alcoholic potash converts it
into bromide of potassium and a brominated organic compound.

Chloride of Cinnamene. — C*H"C1*. Oil^ li<^uid, produced by the action of chlorine
on cinnamene. It is decomposed by distillation into hydrochloric add and another
oily compound.

Treated with alcoholic potash, it yields chlorocinnamene, C*H'OL

Dnehloride of Dichlorodnnamene, CH'Cl'.SCl*, is obtained, according to Lanrenti
by the action of dilorine on cinnamene.

CINNAMIC ACID. 983

NrrBOGiNHAiaDni. Nitrostj^oL C"H*(NO*). — Prodnced by the action of fuming
nitric acid on cinnamene (p. 080). It cryBtallises in large -prisms ; has an odour of
cinnamon which excites tears ; produces painful blisters on the skin.

yitrometacinnamenf. Niiromftastyrol. Nitrodraconyl. — This compound, isomeric
with the last, is precipitated on adding water to the product of the action of fuming
nitric acid on metacinnamene. It is a white amorphous powder, insoluble in water,
acids, potash, ether, and alcohoL When slightly heated, it bums with explosion.
When distilled with lime, it is decomposed, with separation of carbon and evolution of
ammonia, together with a small quantity of a brown oil containing phenylamine. It
does not appear to be attacked by strong nitric acid, even after several hours' boiling.

cmAMZO ACXD. C*H*0* « ^^h1^* ZimmUdure. Cinnamylsaure.

(Dumas and F^ligot [1834], Ann. Ch. Fhys.lvii 311. — ^R Simon, Ann. Ch. Pharm.
zxxi. 265. — Stenhouse, imd. Iv. 1; Ivii 79. — Herzog, Arch. Pharm. zvii. 72;
zx. 159.— E. Kopp, Compt. chim. 1847, p. 198; 1849, p. 146; 1850, p. 140.— Ca-
hours, Ann. Ch. Phys. [3] xxiii 341.— Schabus, Wien Akad. Ber. 1850 [21 206.
— Chiozsa, Ann. Ch. Phys. [3] tttit. 439. — J. Lowe, J. pr. Chem. Ixv. 188. — ^Piria,
Ann. Ch. Pharm. c. 104. — Sertagnini, Cimento, iv. 46. — Gm. xiii. 268. — Gerh.
iii 388.) — This acid exists in the free state in several balsams, as in liquid storax,
Tolu balsam, Peru balsam, and gum benzoin, and is often deposited in lai^ prismatic
crystals from old samples of oil of cinnamon ; also from dnnamon-water.

Formation. — Cionamic acid is produced : 1. By the action of oxidising agents on dn-
namic aldehyde and on styrone. — 2. By heating bitter-almond oil with chloride of
acetyl in a sealed tube to 120<'— 130^ C, but not higher, for 20—24 hours, hydrochloric
add being formed at the same time :

C'H«0 + C«HK).C1 - HCl + C^»0«

The cinnamic add may be extracted from the viscid residue by digestion with water
containing ammonia. — 3. By boiling cinnamein with potash, benzylic alcohol being
formed at the same time (p. 979). — 4. By fusing styradn with potash (Fr6my) or
boiling it with potash-ley. (Simon.)

PrqHiratian, — a. From the deposit of dnnamate of lead mixed with dnnamie add,
found in the old leaden packages in which oil of cassia-dnnamon is imported. The
deposit is dissolved in alcohol and filtered from the dnnamate of lead, and the alcohol
is removed from the filtrate by distillation ; the cinnamic acid then quickly ciTstallises
out from the oil, and is purified by treatment with carbonate of sodium and precipitation.
The residual dnnamate of lead is boiled with carbonate of sodium, filterod f^m the
carbonate of lead, and the dnnamie add is predpitated by dilute sulphuric add, in
silvery lustrous laminse, which are washed, and recrystallised firom alcohol (H erzog).
Dumas and P^ligot dissolve the crystalline depodt from oil of dnnamon in boilug
water, and evaporate the filtrate to the crystallising point

b. From Liquid Storax, — Liquid storax is distilled with water and I to ^ pts. of crys-
tallised carbonate of sodium, whereupon styrol passes over. The residual aqueous liquid
is filtered from the resin ; and the filtrate is mixed at first with just so much sulphuric
add, that a very small quantity of cinnamic acid is precipitated along with dissolved
resin ; and the liquid filtered from this precipitate is treated with ezcesA of sulphuric
add, which predpitates cinnamic add of a tolerably white colour. It is dissolved'
in a large quantity of water, with as little carbonate of sodium as possible, and again
precipitated, first with a little sulphuric add, and then, after the filtration, with an
excess of acid, by which a white {)redpitate is formed. This is washed with water,
dried, and dissolved in alcohol, which, by spontaneous evaporation, yields quite white
and very large crystals (£. Simon). Erdmann and Marchand purify the acid by dis-
tillation, pressure between paper moistened with alcohol, and repeated crystallisation.
D. Howard (Chem. Soc Qu. J. xiii. 72) finds that cinnamic add prepared from liquid
storax contains a small quantity of benzoic add, from which, however, it is purified by
crystallisation from alcohoL

c. From Balsam of Peru, — When the slimy reddue which deposits in Peruvian
balsam by keeping, is dissolved in warm alcohol, and the filtrate is placed in a tall
and narrow cylinder with a layer of water on the top, crystals of nearly pure cinnamic
add separate in a few days f^m the clear brown liquid (H erberger). When Peru-
vian balsam is boiled with thick milk of lime, the liquid filtered, the residual magma
exhausted three or four times with boiling water, and the solution again filtered, the
filtrate deposits on cooling, loose, almost white masses of crystals ; and these, when
decomposed bv hydrochloric acid, yield nearly pure dnnamie add, which majr be ob-
tained perfectly pure, either by distillation, or by solution in ammonia, filtration, and
predpitation wlule hot by hydrochloric add (R Kopp). Simon proceeds as with
storax.

3b 4

984 CINNAMIO ACID.

d. From BaUam of Tolu, — ^BaUuun of Tola is boiled six or seven times with soln-
tions of carbonate of sodium, which are taken continually weaker (the last extracts only
contain a little benzoic acid, produced by the action of the alkali on the resin) ; anJ
the alkaline decoctions are strongly concentrated by eraporation, and precipitatipd hot
by hydrochloric acid, whereupon most of the einnamic add melts into a brown resiii,
and but little crystallises out on cooling: The latter is pressed, the resin is polTerised,
and both are dissolyed in ammonia diluted with 2 pts. of water, and heated to 80^ C.
The greater part of the resin then remains dissolved. The liquid is filtered; the re-
sidue is boiled with water ; and the whole of the very brown liquids are evaporated
and decomposed, while boiling, by hydrochloric acid, whereupon most of theaad again
melts, while the remainder seprates out on cooling in nearly white crystalline acidea,
which are preaaed, and washed with a little cold water. The melted acid is alao washed
with a little water. The whole of the acid is heated in a porcelain dish covered with
paper till the water is expelled — very little acid subliming even at 200*^ C. — and the
fused residue is bruised and distilled. Pure einnamic acid then passes over as a oololl^
less^ clear, stronely refracting liquid, which solidifies to a white crrstalline mass like
stearin. Towards the end, yellowish vapours arise, which, when collected in another
receiver, solidify into a mass of add, which is contaminated by the presence of the em-
pyreumatic oils of the resin, but may be obtained quite pure uy reczystallisation from
boiling water. (£. Kopp.)

2^ropertie8. — Cinnamic add oystallises in colourless prisms or laminae belonging to
the monoclinic mtem. Ordinary combination, odP . [ odPoo ] . [Poo ]. Batioofoiiho-
diagonal, dinodiagonal, and piindpal axis » 0*3674 : 1 : 1'1694. Inclination of dino-
diagonal to prindpal axia m^ 82^ 58'. Qeavage perfect parallel to [ ooPoo ]. Spediie
gravity of crystals «■ 1*196.

Cinnamic add dissolves sparingly ia cold water, easily in boiling water, alcohol, and
ether ; water predpitates it from the alcoholic solution. It melts at 129^ C, and hoils
without decomposition at293<> (Dumas andP^ligot), at SOO^ — ZO^^ (£.Kopp),with
or without decomposition, according to the mannex in which it is heated. If enclosed
in a sealed tulM, it may be heated to 200^ C. (in a paraffin-bath) for several hoon
without alteration. (Howard.)

DecoTnpositions, — 1. CSnnamic add, when slowly distilled, is resolved into dnnam^w
and carbonic anhydride: C»HK)> - C»H» + C0«, a small quantity of stabene, C"H",
being likewise produced, and passing over with the cinnamene (Howard), — 2. On nd-
hot platinum^foil, or in the fiame of a candle^ it burns with a smoky flame (Bisio). On
red-hot charcoal, it evaporates without fiame producing a strong bitmg smoke. — 3. Strong
gidphuric acid, or sulpnurio anhydridt, converts it into suipho-cinnamic add. — 4. Cin-
namic acid heated with excess of iodine^ melts to a dark brown mass; and when this
mass is heated with water, and the excess of iodine expelled by evaporation, iododn-
namie add crystallises out on cooling (Hersog).— 5. Jaromine passed over dnnsmate
of silver forms bromocinnamic add (He r zog).-— 6. Chlorine passed in diffused dajlight
over dry cinnamic add, forms a tough greasy substance, which, when heated vith
carbonate of potassium, forms chlorocinnamate of potassium, and depodts a white oil
containing chlorine (H e r z o g). The same products are formed when chlorine is psssed
into warm aqueous cinnamic add or cinnamate of sodium, and when dn'r**'"'^^ acid u
distilled with hypochlorite of calcium (Stenhouse, K Xopp), or with chbrate of
potassium and hydrochloric acid. — 7. Strong nUrio add converts cinnamic add into
nitrobenzoic add, provided the mixture be kept cool; otherwise nitrous fumes are
evolved, and hydride of benzoyl is first obtained, then benzoic and nitrobenzoic acids.
The same products are formed on heating cinnamic acid with more dilute nitric acid.
— 8. Boiled with peroxide of lead in aqueous solution, dnnamic add gives off the odoor
of bitter-almond oil, while the peroxide of lead assumes a light yellow colour, and is
partially converted into benzoate of lead. This behaviour serves to distinguish cin*
namic add from benzoic add (Stenhous e). — 9. Cinnamic add distilled with sulpkurte
acid and acid chromate of potassium, yields oil of bitter^almonds (Simon).— 10. Wi^
pentachloride of phosphorus (also the trichloride, according to B 6 champ), ityidd^

chloride of dnnamyl (Cahours) 11. Fused with hydrate ofpotassiumy it giye« o»

hydrogen, and forms acetate and benzoate of potassium, a small quantity o( xUej^^
of potasdom being slso produced by the action of potash on the benzoic add pre-
viously formed (C h i o z z a) :

C»H»0« + 2KH0 - C«H»KO» + C'H«KO» + H«.

Cinnamic add is not decomposed by boiling with strong caustic potash (Simon).-^

12. In the dry distillation of the alkaline cinnamates or of dnnamic add with etntstie
baryta or lime, a carbonate is formed, together with cinnamene and benzene.-'

13. Cinnamate of caldum, distilled "with. forTnate of calcium, yields dnnamic ald^Jw
(Piria.) The reactions 6, 7, and 8, serve to distinguish cinnamic add from henzoic
«dd.

CINNAMIC ACID. 985

GiXNAif ATBt. — Cinnamic acid ib monobasic, the formula of itssalts being C'H'MO*.
They are cryBtaUiaable, and bear oonsiderable resemblance to the benzoates. The
cinnamatee of the alkali-metals are easilj soluble in water ; those of the earth-metals
and heavy raetals sparingly soluble, the least soluble being the silyer-salt. They dii-
Bolve moie readily in water containing chlorides or nitrates.

The solutions of most cinnamatra yield a precipitate of cinnamic acid when decom-
posed by the stronger acids. Cinnamates are decomposed by dry distillation, giving
off an oaour of bitter-almonds. With strong niirie acid, they turn yellow, and give off
the odour of oU of cinnamon and bitter-almond oil They likewise yield bitter-almond
oil when distilled with ehromio acid. Vfith ferric salts, uey give a yellow precipitate,
and with manganaus salts, the dnnamate being in excess, a white precipitate which
soon becomes yellowish and czystalline. Benzoates give a reddish precipitate with
ferric salts, and none with manganoos salts. The cinnamates have been investigated
chiefly by Hersog (J. pr. Chem. xxiz.61), and K Kopp (Gompt. rend. liii. 634).

Cinnamate o/Muminium, — ^Loose white powder, sparingly soluble in cold, easily in
hot water.

CinnamaU of Ammonium, 2C^H*^NH*)0*-f aq. — Sparingly soluble in cold water :
eires off ammonia when melted, yielding a Gnrstamne sublimate and a resinous residue.
With excess of dniuunic acid, it forms an ada salt still lees soluble in water. (H erz og.)

Cinnamate qf Antimony and Potassium is deposited from a mixture of cinnamate
of potassium and tartar-emetic, in delicate hydzated aq^stals, which redissolve if left
for a long time in the li<}uid. The salt yields by calcination, a colourless residue,
which effervesces with acids^ and is coloured orange-red by sulphuretted hydrogen.
(Herzog.) ^^

Cinnamate of Barium, 2C*H^aO'+ aq. — ^Precipitate, soluble in boiling water, erys-
talHsing on coolinff. Gives off its water at 110^ C. (He rsog). Accordingto E. Kopp,
the salt forms broad, irregular, transparent, nacreous laminaR oontainins CH'BaO* + aq.
becomes anhydrous at 140^ C. and when distilled with excess of baiy tic hydrate, yields
nearly pure dnnamene.

Cinnamate of Calcium, G*Hn3aO*+ aq. — ^Yery little soluble in odd water, easily in
boiling water, whence it separates in light dystaUine masses (He r zo g). — 3G*H'CaO' +
8 aq. White shining needles compoMd of thin nacreous laminan, having the form of
nearly rectangular puallelograms. It gives off one-third of its water when exposed to
liie air at ordinarv temperatures, and we rest at 150^ C. (£. Kopp.)

Cinnamate of Vobalt. — Bose-coloured precipitate, soluble in alcohoL (Herzog.)

Cinnamate of Coj)^, CH'CuO'.«CuHO. — The greenish-blue precipitate obtained
by double decomposition, is a highly hydrated basic salt. When heated, it loses its
blue colour and decomposes, giving off cinammic acid and dnnamene, and leaving
metallic copper mixed with charcoaL

Cinnamates of Iron. — ^Both ihe ferric taid ferrous salts are yellow predpitates, spar-
ingly soluble in water. (Herzog.)

Cinnamate of Lead, C'H'PbO*. — Granular crystalline powder, anhydrous and in-
soluble in water (Herzog). Sometimes obtained in laminae, flattened or elongated
into needles, and in small hm rounded grains (£. Kopp). Alcohol extracts a portion
of the cinammic add, leaving a basic salt

Cinnamate of Magnesium, 2C*H^MgO' + Saq., czystallised in the cold, forms small
white needles, which quickly become opaque on being exposed to the air. From a
boiling solution it separates in tufts of shining needles, formed by the supeipoeition of
elongated lamime, vexy thin, and of nacreous aspect. It melts at 200^^ C. and be-
comes anhydrous.

Manganous Cinnamate, C'H'MnO' + aa.— Yellowjsh-white crystalline precipitate,
which dissolves in boiling water acidulatea with acetic add, and separates therefrom in
shining yellowish laminse, superposed on one another. (£. Kopp.)

Mercurous Cinnamate, — White curdy predpitate.

Cinnamate ofNickeL — Green precipitate soluble in alcohoL

Cvnnam4ite of Potassium, 20*H'K0' + aq.— Ciystals belonging to the monodinic
system, giving off their water at 120^0, and decrepitating when strongly and suddenly
heated. It is veiy soluble in water, but less so than the benzoate ; moderately soluble
in iUcohol (Heizog). From a rather strong boiling solution containing excess of caustic
potash, it crystallises readily in nacreous needles, which are anhydrous. (E. Kopp.)

When dnnamie add is dissolved in a hot solution of dnnamate of potassium, a
sparingly soluble acid salt is deposited on cooling. \H erzog.)

ciystalL'ne

after a while ; not much altered by li^t. It is insoluble in boiling water, but dis-
solves slightiy in the liquid i^m which it has been predpitated (Herzog). White
predpitate, or silky nacreous needles composed of small elongated lamina^ often bi-
Aircated. (E. Kopp.)

Oinnamate of Sodium, aC^fnO* * aq. — CiTitala vith dull Borfeee. *faich gire off
their water at 110° C, (Heriog). Tho anhjdroua salt, PH'NaO' + 2«q., crjatallue*
in cTQsta Eonnounted vith txifla of small needlra, or in compact nodules. FVom a
lolntioD in weak caustic >oda, it optaUises in benulifal needles containing j at. mter
of cryBtallisation. !□ Htrang eanstic soda, it dlMolrea but sparingly at common t«npe-
catora, Mparating in hard, yiillowiBh.tadiatad.iuihydrona spfaem. (K Kopp.)

Cinnamale of Sfrond'nm, CH'SrO' -^ 2oq., when recently cryBtallised, fonni irtiita,
nacreoui, uearly opaque needles, composed of Tery amall primis. It is much more
■olable in hot than ia cold water ; gives off 1 at vater vtien exposed to iij air, and
the reat nt. ItOT.. (R. Kqdd.1

Cinna
(Her.o,

Cinna
of hydro
BogJ,-;
cryittuui
likemu

ClIfH

1876).-
drochloi

Specific

There*

pores, I

eoUdifii

CINNAMIC ACID. 987

from water, soUdifles on standing in open Teasels, to a fiuntly coloured crystalline mass,
which mav be recrystellised from alcohol (S char ling). — 8. Liquid storax is mace-
rated or digested at a temperature not exceeding 30° C. with 5 to 6 pts. of dilute soda-
ley, till the residue becomes colourless ; this residue is coUected, washed, dried and
dissolved in alcohol containing ether ; and from the solution, which, if not colourless,
is to be rendered so by treatment with animal charcoal, pure styradn crystallises out.
(Gossmann.)

Proper^ie«.--Cinnamate of cinnyl,or styracin, crystallises in tufts of beautiful prisms,
destitute of taste and odour, insoluble in water, sparingly soluble in cold alcohol, Tery
soluble in ether. It melts at 44° C. (Toel, ScharlingX at 38° (E. Eopp), and re-
mains liquid and yiscous for a long time after cooling. It distils without deoompoei-
tion in steam heated to 180° C. (Scharling.)

In treating storax as above described, styradn is sometimes obtained in a liquid,
uncrrstallisable state, especially if it has been left too long in contact with adds to
free it from the last traces of soda.

Deoampontions. — Styracin in contact with caustie alkalis solidifies to a mass of
agglomerated granules. When distilled with potash, espedally with strong alcoholic
potash, it is decomposed like other compound ethers, yielding dnnylic alcohol (styrone)
and cionamate of potassium :

<^?Jo.fo-<^So.c^o|o.

CinnuBJUe ClniiTlic CInnamie

ofclDDjL «looboL acid.

Heated with nitrio acid it yields hydride of benzoyl, hydrocyanic add, benzoic acid,
and nitrobenzoic add. With chromic acid^ it yields hydride of benzoyl, benzoic add,
and a resin. With a mixture of stdphurio acid and peroxide of manganese^ it yields
hydride of benzoyl With strong aul^huric acid, it yields dnnamic acid and a brown
snbftance, soluble in water, insoluble in saline solutions.

SuhetiitUion'derifxitiffes of Oinnamic Acid,

Bboxocinkakio Aoid. CH^BrO'. — This add is obtained by passing bromine
Tapour in excess over dnnamate of silver, treating the decomposed salt with ether,
and evaporating the filtered solution. A thick oil then remains, which dissolves par-
tially in potash, and the alkaline solution decomposed by hydrochloric add deposits
crystals of bromodnnamic add. The portion of the oil insoluble in potash is probably
a bromide of carbon.

Bromodnnamic add decomposes partially when dissolved in water and evaporated.
It forms easily soluble salts with all bases, and does not predpitate nitrate of silver.
(Herzog.)

Chlorocinkaicio Aoid. C*H'C10*. (E. Kopp, J. Pharm. [3] xvL 426. — Toel,
Ann. Ch. Pharm. Ixx. 7.)— Obtained : 1. By passing chlorine into a cold solution of
dnnamic add in concentrated carbonate of sodium (%opp). — 2. By the action of alco-
holic potash on an alcoholic solution of chlorostyracin, a chlorinated oil and chloride of
potassium beins formed at the same time. The mixture soon solidifies to a pulp,
which is washed with alcohol, pressed, dissolved in a small quantitpr of boiling alcohol,
and mixed with excess of hydrochloric acid. Chlorocinnamic acid then crystallises
out on cooling, and may be purified by reerystallisation.

The acid crystallises in long shining odourless needles, melting at 132° C, and sub-
liming at a higher temperature. Its vapour exdtes coughing. It is sparingly soluble
in cold water, melts in boiling water, dissolves easily in alcohol and ether.

ChlorocinnanuUe of AmnumiuTn^ 2G*H*C1(NH^)0' + aq., forms curved arbores-
cent needles. The potaS8ium-^alt forms lustrous pearly flakes. The barium'Salt^
2CH*ClBaO' + aq., is precipitated as a white powder, soluble in boiling water, and
crystallising therefrom in shining lamine. The calcium-salt is sparingly soluble, and
resembles the barium-salt. The silver-salt, CH'ClAgO*, is obtamed by predpitation
from hot solutions, in slender needles which blacken on exposure to light.

Ckloroeinnamate of Oinnyl or Chlorostyracin, C"H**C1*0'. — Clilorme converts sbr-
ladn into a visdd substance, having an acrid taste and an odour like that of copaiba
balsam. It is insoluble in water, soluble in boiling alcohol and ether, whence it sepa-
rates in the unofphous state. It is decomposed by potash, yielding a chlorinated oil,
chlorodnnamate of potasdum, and chloride of potassium. Distilled in a current of
chlorine, it forms a volatile chlorinated liquid ana a oystallisable chlorinated add, the
salts of which also erystalUse readily. (£. Kopp.)

NiTHOciNKAKic AciD. C»H»(NO«)0«. (Mitscherlich, Ann. Ch. Phys. [3] iv.
78.— B. Kopp, Compt chim. 1849, p. 146 ; Compt rend. liii. 684.— J. Wolff, Ann. Ch.
Pharm. Ixxv. 303.) — This add is produced by the action of strong nitric add on dn-

Damic acid (MitBelierlich, Kopp), or by heating strrone with nitric add, loidiiA
oreaiB added to preT«Dt fonnatJon of nitniiia acid (Wolff). To (ireura it, ajoca-
tiBtod nitric acid ia &eed ttom sitroiu acid by boilmg, and after coolm^ iJxiit no-
eighth ofeinnamie acidiv added. Thaciimanue add dinolTeii in afevmiuntnwitJiciei
diMngagemeiit of gas, tha liquid beoomes haated to 40° C, and a maaa of crjiitili a
deposit^ In ocdcT to obtain iaiger qnantitieB, dnnainic add ia tritunted with nitn
acid and ccxiled, ao that the temperatoic may not riu above 60° ; the mua ia vuhid
with cold vat£r, till all nitric add ia lanored, then disaolved in boiling ilcoliol ud
Sltered; and the resulting ciyrtala are va^ed with cold alcohol (Mitscheilicht.
Kopp diaaolvea 1 pt of powdered cinnamic afid in 3 pta. of moDobTdrslcd nitric iQd
ftf-ed &om nitroui add by paaaiBg a dry stieam of air throogh it, tJie miiton tbm ■>
lidifytng almost immediately, in consequence of the cryBtallisaition of the mtniciniiimie
acid; waahea the magma with wafer; then dries, and set^ it aside tor tweuty-foin bgiin
with 4 pla. of cold alcohol, which removes any benzoic acid that may be present.

The add forma very small white eryatals, with a &iat yellowish tinL It mdtl il
aboutS70°C^aDdsolii£fieatoamaBa<rfe>7atalsoncDolinB; boils a litde above 270°, vilb
decomposition. It ia nearly insoluble in oold water, and disaolTea but epari^ j in Inl'
ing water; 1 pt of it dinolvea in S27 pta. of absolate alcohol at 20° C. Ba£ngbjira-
cUoric add dissolves it without decompomtion (Mitscherlich.) With i^plult >/
amnHmiuiRit forms car boatyriL When it is dissolved in alooholie sDlphide of unm-
uium, Bolphur separatee on gently wanning the liquid, while a yellow icHin and an lUt
loid remain diaaolved. Nitrocinnamic acid may be boiled wiUi excess of ^kali withnt
decomposition.

NitTodcnamie add ia bnt a feeble add; nevertheleoa it fonns nenlnl sails, tod
decomposes alkaline carbonates. The nitrocinnamates of the alkali-metals an ra;
soluble, the rest are insoluble or sparingly soluble; they deflagnte when quid);
heated, eepeciatly the potassium- and sodium-salts.

Kitnxinnamate of Ammonium gives off its ammonia when en^rated ta dryness; id
solution precipitates the salts of caldum, Btrontium, and magnesium when Uiej in
concentrat«d, but not when they are dilute.

mtroeimamabi of Barium, 2CH>(KO')BaO' -i- 3 aq., arstallises &vna a Iniliiig
solntioQ on cooling, in atellaU groups of yellowish needles. The ttrontitm-MU,
2CH"CNO*)SrO" + 6 aq^ may be obtained in small yellowish crysialfl grouped in no-
doles ; it is moderately solnble in cold water. Tha caidum-iail, 2CH'(m?)CaO' t 1*1,
fomu small yellowish white agglomerated grains havinf a crfstalline aspect Tbt
magnttium-^all, (?H*(NO')MgO' + 3 »q., oiysUllises in yellowish white nodulo^ vliid
dissolve with tolerable &cility in water, eepecialij if warm.

IfiirodntianiaU of 0™ier.— Bluish-white precipitate, which beoomes SaAa Aa
air-dried. When miied with sand and distilled, it yields bensoic add, nitiocinumoi
having the odour of oil of cinnamon, and a small quantity of nitrobenzene.

Mcrcune Jrt<nwint!oma(c, (?H'(NO")HgO', is thrown down from boiling Bolntidu of
mercuric chloride and au alkaline nitrocinnomste, as a brownish anbydmis predfil'l'-
The mother-liquors deposit im cooling a ciyntulline mass of very light bul^iHiD-
leacent tufts, consisting of the double salt. 2(HgCL2CH*(NO>)%0*)-r 3*q.

yitrocinnamalrofPotattium. CH*(NO^KO'.— Very soluble; crystalljs« in mwif
lated groups by spontaneous evaporation. From solution in boiling alkaline ley, it
crystaLisee in priamatie needles. The todium-aall resembles the potasaium-salt-

SitrodnHomaU of SUwr. CH*(N0')480'.— Y.-llowish whife insolnblB predpiH".
which, when cautiouBlj heated, decomposes with projection of the silver.

NrmoctimiMio Ethkis.— The cthi/l-compotrnd, C"Hi'NO< - CH'(N0'XC^)9'' "
formed by healing nitrocinnamic ad^with alcohol and solphuric add (UitseheiUcb,
J. pr. Chem. nil. 1 94), or by the action of strong nitric add on dunaniate of ellijl
(E. Kopp, CompL rend. aiiT. 6IS). It crystallises is prisms, vhieh melt at 136°li;
boils with decomposition at 300°. Potash at the boiling heat cwivertB it into slrobol
and nitrodnnamate of potaaaium.

Sitrocinnamatt of Miayl. C'HTfO' = (?H'(NO')(CH')0'. (E. Kopp, Cempt
rend. liii. 636.) — Obtained by heating nitrodnnamie acid with methylic alcotol iiu»^
with a small quantity of sulphuric acid or saturated with hydrochloric add gas. Tie
mixture thickens at flrat, then liquefies again, and finally m brown liqnid is obtaineo.
from which the ether separates as a ciTStatline mass, which may be piuiied by p"^
sure and recrystallisation &om alcohoL It forms white, delicate^ rather rioB^^
needles, sparingly soluble in cold alcohol and ether, and having but httle odour ; seits
at 161° C. to a eolonrlees liquid, which solidifies in a crystalline man on cooling. H
•bout 200° C. it begins to sublime in iridescent crystalline plates, and at 200° it t«iU

CINNAMIC ALCOHOL — CINNAMON, OIL OF. 989

CZnAKZC A&COBOlta See Cimkyijc Alcohol.
Cnnf AMXO ATt'DKHTPa. See Cinnamtl, Htdbidb of.

cnnriUttZO AKBTASZBB. C"H'«0* » (C*H'0)*.0. dnnamate of Cinnamyl
Cinnamic dnnamate, Anhydrous Cinnamtc Acid. (Gerhardt, Ann. Ch. Phys. [3]
xxxviL 285.) — ^Produced by the action of oxychloride of phosphoms on well dried cin-
namate of sodimn, the best proportions being 1 pt. of the former to 6 pts. of the latter.
The product is washed with water and carbonate of sodium, then dried and dissolyed
in boiling alcohol It may also be obtained by the action of chloride of cinnamyl on
neutral oxalate of potassium. It crystallises from the alcoholic solution as a white
crystalline substance, composed of microscopic needles. It is insoluble in cold alcohol,
and dissolTes but slightly eyen in boiling water, becoming acid at the same time. It
melts at 127° C.

AoBTo-ciNNAiQC Anhtdbidb. C*H*0.C*EP0.0. See Acamo Anhtdbids (p. 21).

BsKzo-CDmAKic Anhtdbidb. C^H'0.C*H^0.0. See Benzoic Anhydbidb (p. 558).

NiTBOciNNAMic Anhtdbidb. C»H»«N«0» » [OH«(N0«)0]».0. (Chiozza, Ann.
Ch. Phys. [2] xxxiz. 231.--Gerh. iii. 388.)— Produced b^ the action of oxychloride
of phosphorus on nitrocinnamate of potassium. It melts in boilins water more easily
than nitrodnnamic acid, forming a yellow kneadable resin. It easily takes up water,
and is converted into nitrocinnamic acid. With ammonia, it easily forms nitrocinna-
mide and nitrocinnamate of ammonium. With alcohol, it forms nitiocinnainate of ethyL
It is sparingly soluble in ether.

See page 986.

C»H»NO « N.H«.C»H'0.— Chloride of cinnamyl treated with dry
ammonia, yields sal-ammoniac, together with a white substance which dissolves in
boiling alcohol, and separates in delicate needles in cooling. (Cahours.)

NrrBOdNNAMiDB. C'E^N'O" « N.H2X?H«(N0«)0. (Cahours, Ann. Ch. Phys. [8]
xxvii 452.)—- Prepared : 1. By the action of aqueous ammonia on the product ob-
tained by treating nitrocinnamate of potassium with oxychloride of phosphorus. After
an hour^s digestion at a gentle heat, the reaction is complete, and the nitiodnnamio
anhydride is completely transformed into nitrocinnamide and nitrocinnamate of am-
monium, which remains in solution. The nitrocinnamide is collected on a filter and
purified by crystallisation from boiling water. — 2. By the action of alcoholic ammonia
on nitrocinnamate of ethyl ; this process, however, takes a long time, and requires a
large quantity 6f alcohoL

Kitrocinnamide separates from solution in boiling water in shortened, lustrous
needles, sometimes in grains and laminse having the appearance of flies' wings. It
melts and turns brown between 155^ and 160^ C, and decomposes completely at 260^.
It dissolves sparingly in cold alcohol, moderately in ether, and separates from solution
in boiling alcohol in small, very regular, hemispherical concretions, smooth in the
upper, and nodular in the lower part. It dissolves in caustic potash, producing a red
solution, without evolution of ammonia.

Phentl-Cinnamidb. dnnanilide. N.H.C*H».C»H*0. (Cahours, Ann CL Phys.
3] xxiii. 344.) — Produced by the action of ^henylamine on chloride of cinnamvL
t dissolves easily in hot alcohol, and separatee in slender needles on cooling. It melts
at a gentle heat, and distils completely at a higher temperature. Potash-solution
Bcareely attacks it, even with aid of heat ; but when fused with hydrate of potassium,
it gives off phenylamine.

NiTBANisTL-CiHNAiODB. dnnttranistdine. C»«H'<NK)* - N.H.C'H«(NO*)O.C»H^O.
— Produced by the action of chloride of cinnamyl on nitranisidine (p. 304). Vellowish
needles, sparingly soluble in cold, more soluble in boilins aloohoL (Cahours.)
aXMWJkMJXKBM, Syn. with Phsnyl-Cxmnabodb {vid. tup.)

CUMJIHapmillimim C*rH**N^ - NXC*b*)*.~A compound produced by the
action of ammonia on hydride of cinnamyl It is analogous to hydrob<mzamide,
C^iH^vN*, and is therefore more properly called hydrocinnamide (^. v.)

OZnAMOW, OI& or, and QTMb or cassia. These oils, which are nearly
identical in composition, are obtained from the bark of different trees of the genus
dnnamonumj order Lauraeem, viz. oil of cinnamon from Ceylon cinnamon, dnnamO'
mum Zeyianieum; and oil of cassia^ from the bark of Chinese cinnamon, dnnamomum
aroTnaUeum, or from cassia buds, the undeveloped flowers of dnnamomum LauresH
(Nee s). The oils are prepared by softening the bruised bark or flowers with salt water,
distilling quickly, and drying with chloride of calcium. Oil of cinnamon has a more
agreeable odour than oil of cassia, and is therefore more esteemed.

Both the oils consist mainly of cinnamic aldehyde, which may be separated hj means
of an add sulphite of alkali-metal (p. 991) ; also a hydrocarbon, not yet examined, in
variable, but always yery small quantity, together with dnnamie acid, and resins.

[

Oldsample* afl«n d^poditerTstala of dmutmit: acid. The densitj of the oils Tuica frum
l-02Stol'OE; their boiling point &om 220° to 226° C.

Retint from Cinnamon^oU. — Old umpleB of the oil ore more ai less colonrFd aod
charged Tith resinous matterB, vhich remain, after the oil has beai distilled with salt
wstar, the residQe treated with cold water, to extract the suit, and aAerwaids with
boiling water, to eilract einnamic acid. According to Malder (Ann, Ch. Pharm.
' r. H9], there are two resins farmed in the oil by atmospheric oiidatioii ; one, a.

hydrogen, and IG'18 oxygen ; the other, P, BparLDglTSolable onlj in hot akoho), radt-
iogat 116°, and containing 834S per sect. C. 0-06 H, and 10-49 0.

Mulder likewiee describe Bevenu other reeins, some soluble, others insolobla in al'
cohol, produced by treating oil of cinnamon with solphniie acid, hydrochloric acid, and
ammonia : they have all nearly the same compodtion as the ^-nain, produced hj at-
mospheric oxidatloD. (Om. ziiL 261.)

onnrAKOH-aTtnrm. A variety of garnet (}. e.)

om&BTTX. CH'0.~The mooatoniic radicle of dnnamie add and its dcoin-
tiiea. The following is a list of its componnds, and of those of tbe deriTed tadielea,
chloncinnaiDyl, &c

tMoride of Cinnamyl (^H'O.CI

CTanideofCinDamyt CH'O.Cy

Hydride of Cinnamvl : Cjnnantw Aldeht/dt .... CH'O.H
Hydride of letrachlorocinnamyl : CAiDTomnnoM . . CH'Gl'O.H

Tspe-RRO:
HjdratflofCinnamyl: Cinnamie Acid . . . (WO.H.O
Hydrate of Bromocinnamyl : BTOmecHnamic Aeid . C»H*BcO.H.O
Hydrate of Chiorooinnamjl; CMorocinnamio Acid . CH'OO.H.O
Hydrate of Nit«>cinnamyl : Sitrocinnamis Add . CH*(N0')'0.H.O
Oxide of Cinnamjl : Cinnamie Anhydnde .... (CTH'0)'0
Oxide of Cinnamyl and Acetyl : Aceto-cinnamic Anhy-
dride CH'O.CHK).©

Oxide of Cinnamyl and Benzol : Brmo-cinnamie Ashi/-

dridt CH'O.CH'0.0

Oxide of Hitcocinnamyl : Nitrocinnamic Anhydridt . [CH'(K0')01'O
Tspt'SB}-.

Cinnamide V.'B.'.CB^O

Phenyl-dniMunide : Cinnanilide .... N.H.CH'.C^'O

Nitranisyl-cinnamide : CiTmiiranindint . N.H.CH*(N0')0.t?H'O

The compounds of cinnamyl are intimately related to those of bsnioyl, CH?0, and

are easily converted by oxidising Teagents into hydride of benzoyl and hfsaxnt: vid.

Cinnamie acid heated with excess of hydrate of potaasinm, ie leBolved, with erolatiDa

of hydiflgen, into acetic and benioie acids (p. 984).

omAWYXq OKIrflKZm or. CH'O.CL (Cahonrs, Ann. Ch. Fhn. [3]
iiiil 341.— B& champ, Compt. rend. xliL 224.)— This compound is {vodtK^d by the
action of trichloride or pentachloride of phoephoms on cumamio acid. When the
pentocbloride is used, tbe product is distilled, the portions which paw over between
250° andaSS" C. being collected apart and rectifiKl (Cahoars). With the trichlo-
ride, the mixture must be heated to between 60° and 120° C, as long as hydtochkne
acid continues to escape. It then melts and forms two kyers, the upper of iriii^
consisting of chloride of cinnamyl, is decanted and distilled. (Bi champ.)

Ciloride of cinnamyl is a heavy oil, of Bpociflc gravity 1 -207, boiling at 263° C In
a moist atmosphere it decomposes quickly, yielding hydrochloric acid and fine eryalali
of cinnamie acid. In contact with alcohol, it braomea strongly heated, and if walT
be then poured upon the mixture, cinuamate of ethyl separatea aa a heavy oil. With
ammonia and phenylamine, it yielda cinnamide and phenyl cinnamide respectivtJj.
Heated with cinnamate of aodium, it yields cinnamie anhydride.

cmAJCTK, CTAXX9B OV. Ci'H'NO ~ (CH'O.Cy. (Cahonrs, ^ ril)
— Produced by distilling chloride of danamyl willi eyanide of potasaiiUD or cyanide

CINNAMYL: HYDRIDE. . 991

147.— Bertagnini, ibid. Ixxxv. 272.— Gm. xiii. 268.—Oeph. iii. 373.)— This com-
pound forms &,e essential part of oil of cinnamon or oil of cassia, and may be sepa-
rated therefirom by tlie action either of nitric acid or of the acid sulphites of the
aUcali-metals.

0. When commercial oil of cinnamon is shaken dp with strong nitric acid, laree
crystals are formed, after two or three hours, consisting of a compound of nitric acid
with cinnamic aldehyde, which, when collected on a filter, so as to allow the still liquid
portion to drun off, and then decomposed by water, yields pure cinnamic aldehyde.
(Dumas andP^ligot.)

5. Oil of cinnamon is agitated with three or four times its yolume of a solution of
acid sulphite of potassium of 28^ — 30° Bm ; and the crystalline mass, which forms in a
few minutes, is separated &om the mother-liquor, left to dry on a filter, then pulrerised,
washed with cold alcohol, again dried, and dissolved at a genUe heat in dilute sul-
phuric acid. A large quantity of sulphurous acid is then given off, and the cinnamic
aldehyde rises to the surface as an oil, which may be purified by washing and drying.

Cinnamic aldehyde is a colourless oil rather heavier than water. It may be distilled
without decomposition, either in vacuo, or with water which has been freed from air by
boiling. When exposed to the atr, it quickly becomes yellow and resinous, and ao- .
quires an acid reaction. It rapidly absorbs oxygen gas, especially if moist, and is
thereby converted into cinnamic acid. Heated with nitric acidj it forms benzoic acid
and hydride of benzoyl. Chromic acid converts it into benzoic and acetic acids
(Persoz). Boiled with solution of hypochlorite of calcium, it yields benzoate of
calcium. Strong sulphuric acid converts it into a resinous mass.

Cinnamic aldehyde gradually heated in a stream of chlorine^ forms at first & liquid
compound, which solidifies when treated with a strong solution of potash. When dis-
tilled four or five times in a stream of chlorine, it is converted into tetrachlorodnnamyl.
With pentachloride of phogphorus, it yields hydrochloric acid and chloride of cinnamyl.
Fused with hydrate of potassium, it forms dnnamate of potassium, with evolution of
hydrogen:

C»H«0 + KHO - 0»H'KO« + H».

Ammonia-gas converts it into cinnhydramide :

SCH'O + 2NH» - C"H«N« + 3H*0.

Compounds of Cinnamic Aldehyde,

a. With Hydrochloric Add. — Oil of cinnamon absorbs a large quantity of hydro-
chloric acid gas, acquiring a green colour and becoming thicker. 100 pts. of the oil
take up 26*9 pts. of hydrochloric acid.

b. With Iodine and Iodide of Potassium. — ^When cinnamon-water is placed in con-
tact with iodine and iodide of potassium and cooled to 0° C, a czy^tallisable compound,
C'H'O.P.EI, is formed. It ciystallises from alcohol and ether, but water decomposes
it, setting free the cinnamic aldehyde. An excess of iodide of potassium prevents the
decomposition. (Apjohn, Ann. Ch. Pharra. xxviii. 314.)

c With Nitric Acid. C*H*O.IINO". — ^Produced when strong nitric acid is left in
contact with cinnamic aldehyde. It fbrms oblique, rhombo'idfd prisms, often two or
three inches long. After being drained, they may be preserved for some hours, but
the least rise of temperature or atmospheric humidity quickly decomposes them. When
treated with water, they vield pure cinnamic aldehyde.

Nitrate of cinnamic iddehyde kept in an imperfectiy closed vessel, yields after a few
days a red liquid, which has the characteristic odour of bitter-almond oil, is converted
by ammonia-sas into nitrate of ammonium and a red resin ; and is dissolved by strong
sulphuric add, the solution yielding with water a precipitate of cinnamic acid.

a. With Acid Sulphites of Alkali'metais, — Cinnamic aldehyde dissolves easily in
aqueous acid sulphite of ammonium, forming an oily liquid, which afterwards sob'dofles
to a crystalline pulp. Oil of cassia shaken up with a strong solution of acid sulphite of
ammonium soon solidifies to a yellow cirstaUine mass, which may be purified from the
hydrocarbon and other substances which the oil contains, in addition to cinnamic al-
dehyde, by washing with alcohol of 80 or 90 per cent (Gossmann). The compound
is very unstable, quickly turning brown, even when kept in closed vessels.

The potassiwnrsalt is obtained by agitating oil of Ceylon or Chinese cinnamon with
three or four times its volume of a solution of acid sulphite of potassium of 28° to
80° Bm.; after washing with alcohol and recrystallisation from boiling alcohol, it
forms beautiftil silvery plates nearly inodorous and permanent in the air. It is soluble
in cold water, but the solution is decomposed by heat, giving off sulphurous acid and
yielding colourless drops of cinnamic aldehyde. Heated in a test-tube, it gives off
water, sulphurous acid, and cinnamic aldehyde, which, by contact with the air, is con-
verted into cinnamic acid. Bromine and iodine dissolve in the aqueous solution with-

992 . CmNYL— CITRACONIC ACID.

out oolonring it, but converting the solphurous acid into solplmric acid, and setting frn
the cinnamic aldehyde. Bromine in excess produces a solid, slightly azomatie bqV
stance fusible in hot water.

Sodinm-^alt. — Oil of cinnamon mixed with solution of acid sulphite of sodinm of
370 Bm. forms a crystalline fibrous substance, which, if left to itself^ soon becomes eom-
pletely liquid ; at the same time there is formed an oil which is not solidified, either bj
acid sulphites of alkali-metal or by nitric acid, the sulphite of cinnamyl-sodimn ippa-
rently remaining dissolTod. The liquid, if left to eyaporate, yields crystals of salpaate
of sodium, together with opaque ci^stalline nodules, which dissolTe in boiling alcohol,
forming a solution which on cooling deposits long thin needles arranged in spial
groups. (Bertagnini.)

Hydbidb OF Tbtbachlobocinnaxti.. Chlorodimow. C*H'C1K).H. (Damas
and Piligot, Ann. Ch. Phys Ivii. 316.)— By repeatedly distilling hydrate of dnnamjl
in chlorine eas, this compound is obtained in long white yer^ Tolatile needles. It melts
at a gentle neat and sublimes without decomposition. It is soluble in alcohol It is
not decomposed by strong sulphuric acid, even at the boiling heat, and may be vdar
tilised witnout alteration in a current of dzy ammonia.

The formation of this substance is preceded by that of seyeral liquid compoasdB, (m«
of which, perhaps hydride of monochhrocinnamyl, solidifies in contact with potaah-ley.

OmrXta C^*. — The radicle of the compound usually called cinnamic akobol
or aiyrone. Cinnyl bears to cinnamyl, C*H'0, the radicle of cinnamic acid, the same
relation that ethyl, C*H», bears to acetyl, C*H»0.

cmr&ZC AX1COBO&. C^H'^O <- C*H'.H.O. HydraU of annyi, Ciiuumc
Alcohol^ Styrone^ Styracone, Styrtue-Alcoholy Styrylic Alcohol^ Peruvin. (E. Simon,
Ann. Ch. Pharm. xxxi. 274.— Toel, ibid. Ixx. 3.— Strecker, ibid. Ixx. 10.— J. Wolft
ibid. bcxxy. 299.— E. Kopp, Compt chim. 1850, p. 113.— Scharling, Ann. CkPham
cxv. 90, 183.— Gm. xiii. 266.— Gerh. iii. 402.)— This compound is obtained by csa-
tiously distilling styracin with a stronff solution of caustic potash or soda. A milkj
liquid then passes oyer, from which, when saturated with common salt, a creamy sob-
stance separates, gradually collecting on the surface in an oily la^er and solidi^Fiog
(To el). Wolff dissolves styracin in boiling alcoholic potash; mixes water with tw
liquid ; filters from cinnamate of potassium ; and separates the precipitated cuooamie
alcohol from undeoomposed styracin by distillation.

Cinnylic alcohol forms beautiful soft silky needles, haying a sweet taste and n
agreeable odour of hyacinths. It melts at 33® C, and yolatilises without altention st
a higher temperature. It is moderately soluble in water, very soluble in alcohol, in e^«i
in styrol, ana in oils, both fixed and volatile. When the aqueous solution saturated at
the boiling heat is left to cool, it becomes milky, and does not clarify for sereral hou^
when it becomes filled with needle-shaped crystals.

CZVOZiIWO. A white marble with shadings or zones of green talc, found is Italy*

OZSBAMra&zmk Syn. with Pblosinb {q. v.)

OZTBACOVABKZBBB and CITKAOOVAMZUCDaB. See Ajodbs or Ci-
TBACONic Acid (p. 993).

CZTKAOOmo ACZB. P^roeitrio Acid, G*H«0\ (Lassaigne [1822],iBO'
Ch. Phys. xxi 100.— Dumas, ibid. cxi. 21.— Robiquet* ibid. hey. 78.— Liebig, Am.
Ch. Pharm. xxvi. 119, 162.— Crasso, ibid, xxxiy. 68— Engelhardt, ibid. Ixx. 24«.
—Gottlieb, ibid. IxxyiL 266.— Baup, Ann. Ch.Phy8.[3]xxxiii 192.— Gm. x 417^
Gerh. ii 120.)— This add, or rather its anhydride, u produced by the dry distillaboB
of citric add, constituting in teuct the chief portion of the distillate (p. 995). The aohT-
dride rapidly attracts moisture, and when exposed to the air, is oonyerted into a oys^*''
line mass of dtraconic add, which is freed from excess of water by pressure ^^^'^
blotting-paper and exposure to a temperature of 60^ C. Citraoonic add is also one oi
the prc^ucts of the diy distillation 01 lactic add.

Citraconic add is inodorous, and has a sour and slightly bitter taste. It oystaUtfes id
four-sided prisms, dissolves in 8 pts. of water at 10<> C, and is readfly soluble in alco-
hol and in ether. It melts at 80^ C. ; small quantities of it kept for some taoe
at 100^ are converted into itaconic add. By dry distillation it is resolved into citit'
conic anhydride and water.

When dtraconic add is heated with strong nitric acid^ a violent reaction is ^^
accompanied by disengagement of gas, and an oily body is produced, which 00 ^"y^^
soUdifies to a crystalline mass, consisting of two crystalline nitro-compoonds, ??'7 .
and dyslyte, which dissolve in alcohol to an unequal extent; their oompofi^oo
not known. By dUuU nitric acid-^ citraoonic acid is converted into mnaoomic f^

When bromine is gradually added to a strong solution of dtraoonate of potassim^ ^
bonic acid is disengaged and a heavy yellowish oil separates, consisting of fto '^ i|^
a neutral substance. The former is removed by treatment with dilute potaah, ▼"^

CITRACONIC ACID. 993

leayes the latter unaltered. When a weak acid is added to the alkaline solution, there is
separated, sometimes a heavy oil and sometimes fine needles. These two bodies are iden-
tical in composition, and consist of an acid, C^H^r'O', which has been named by Ca-
houis, its discoTerer, brofnotriconic acid. It has the composition of dibrominated butyric
acid (p. 693) ; but Cahours did not obtain it by the action of bromine on butyric add
or butvrate of potassium. The liquid acid is ^ghtl^ amber-coloured, and has a pecu-
liar odour, when distilled, it gives off hydrobromic acid and leaves a carbonaceous
residue. The liquid add, after standing for some time, occasionally solidifies to a mass
of czTstals. When it is heated with concentrated potash, a peculiar odour is disen-
gaged, and the addition of an add no loneer predpitates an oiL The add forms a
curdy precipitate with silver-solution, and its ammonium-salt crystallises.

The neutral oil formed in the preparation of the add has the composition CH^r'O,
and may either be tribromopropiome aldehyde or iribrominaied acetone,

Sy the action of bromine on citraconate of potassium, or on this salt in the presence
of excess of hydrate of potassium, an oil is also separated and carbonic add disengaged.
When a weak solution of potash is added, the greater part dissolves, and a small quantity
of tribromopropionic aldenyde remains ; on adding dilute nitric add to the alkaline solu-
tion, large white crystalline fiakes are deposited, consisting of an acid which crystallises
from alcohol and ether in long prisms. It has the composition of tribromopropionic
acid, CHfBrK)*, but Cahours names it bromitonie acid.

GiTBA.ooirATBS. — Citracouic add is a dibasic add, and forms two series of salts,
the neutral ealts, C^K*MH)\ and the aoid salts, CH^MO*; they are isomeric with the
itaconates, mesaconates, and lipates. The add salts mostly crystallise welL

The acid barium-^alty C*H*BaO\ crystallises in large groups of fine silky needles.

The neutral silver-salt, C*H*Ag*0\ crystallises both anhydrous and with an
atom of water. In an aqueous solution of dtraconic add, nitrate of silver produces,
on addition of ammonia, a venr bulky precipitate which dissolves in boiling water.
On coolingi the salt is deposited in long needles. If tiie mother-liquor froni this be
slowly evaporated, hexagonal crystals are formed whidi have an adamantine lustre, and
consist of the hydrated salt, C»H*Aff»0* + H*0.

The acid silver-salt, OH*4gO\ is obtained by dissolving the neutral salt in an
add solution of dtraconic acid. On evaporation, large groups of ciystals are obtained.

Citraconate of Ethyl, or Citraeonio Ether, G*H"0\ is obtained by repeatedly
cohobating amixtiire of alcohol, dtraconic add, and hydrochloric add, and wasning the
distillate with water.

It is a colourless, bitter, somewhat aromatic li<juid, of density 1*040 at 18^'5 G. It
boils at 225^0. with partial decomposition. It is insoluble in water, but readily soluble
in alcohol and in ether. In contact with water, it gradually addifles and alcohol is
formed. By potash it is decomposed into dtraconate of potassium and alcohol £. A«

OiTBAOOKAXiDB, C^H«NK)« - K^.H^CC'E^O*)*, is obtained as a yellow viscid
mass, which becomes brittle and vitreous on cooling, when dtraconic anhydride is
heated in a stream of dry ammoniacal gas. It dissolves in water, and the solution on
cooling yields dtraconate of ammonium. It is derived fsom neutral dtraconate of am-
monium by the loss of 2 at. of water :

C»HXNH<)«0* - 2H«0 - C*H"NK)«

CiTBAOONixiDS. G»H»NO» - N.H.(0*H<0*)''.— Citraconic add is mixed with
excess of ammonia and evaporated to dryness, and the residue heated to 180^ C. An
amorphous oily yellow mass is left, which is citraoonimide. It does not dissolve in cold
water, and but slightly so in alcohol ; it is highly hygroscopic. It is derived from
add dtraconate of ammonium by the loss of 2 at. of water :

C»H»(NH*)0« - 2H«0 - C*H*NO«.

Phenylcitraconimide or CitraconanU, G"H*NO« - N.O^BP.CC^H^O*)".— When
anhydrous dtraconic acid is mixed with phenylamine, a brisk action ensues, and the
mixture, if kept for some time in the water-bath, is totally converted into the above
compound. It crystallises in colourless needles, which melt at 96^ G., and sublime at
a little above 100^. It is readily soluble in alcohol and in ether.

It is derived £rom add dtraconate of phenylamine by the loss of 2 at of water :

C»H*(G«H«N)0* - 2H«0 « C"H»NO«.

lodophenylcitraeonimide, G^*H'INO*, is obtained by substituting iodophenylamine in
the above reaction.

Dinitrophenylcitraconimide, G"H'(NO*)*NO», is obtained by the action of a mixture
of nitric and sulphuric add on phenyldtraconimide.

Vol. L 3 8

994 CITRACONIC ANHYDRIDE — CITRIC ACID.

Citraoonamio Acid. C»H^O^ « N.H».OH*0*.H.O.— Citraconiinide appeals to
be partially convertible into this acid by boiling with ammonia. Its salts are im-
crystallisable.

Phenylcitraconamic Acid, C"H"NO* =^ N.H.C«H».C»H*0».H:.0, i« obtained m
an ammoninm-salt by boiling pheny lei traconimide with dilate ammonia. On the addition
of acetic acid, it is separatea as a crystalline precipitate, which is washed with cold
water. It is an unstable body. It is deriyed from acid citraconate of phenjlamiiia
by the loss of an atom of water :

C»H*(C«H"N)0* - HK) - C"H»»NO«.

JHnitrophenyleitraoonamic add, C"H'(N0')'NO*, is obtained in a friwiilar maasec

CXTKA.COVZO ASBnmiBB. G^H^O'.^This compound is prodnced by tbe

dry distillation of citric acid, constituting the greater part of the cnide product. On
rectifying this crude distillate, two layers are formed, the upper being aqueoos, and the
lower an oUy acid liquid which does not solidify. This, which is dtraconic anhydride,
is purified by redistillation. The same substance is formed by heating itaoonic acid

Citraconic anhydride is a colourless inodorous liquid of specific grarity 1-247. It
rapidly absorbs ammonia, with disengagement of heut, forming a ritreons deliquescent
mass, which probably consists of citraconamic acid. £L A.

CXTaACOWZC CB&OSZna. Pyrodtric Chloride, ChUmde of P^froeitrff.
C^H^O^CP. — When pentachloride of phosphorus Lb mixed with citraconic anhydride, a
brisk action ensues, and on subsequent distillation, oxychloride of phosphoms passes
over, followed by chloride of pyrocitryl when the temperature has rcaiched 175° C.
It contains, however, some citraconic anhydride, which raises the boiling point ; it
is freed therefrom by redistillation with pentachloride of phosphorus, the part dis-
tilling between 175° — 190^ being ultimately collected. It is a highlv refracting fuming
liquid, with a density of 1 '4. With water, it forms citraconic and nydrobromic acidsi,aiid
with absolute alochol, citraconic ether and hydrochloric add £. A.

TBMau See CiTBiLOONATBS (p. 993).
See page 1000.
I (p. 993).

CZTKACOWZOBiLVZIta Syn. with loDOFHENTLCrrBAOOKlMiDB (p. 993).
CXTUmra. dtronyl. C***!!". — A liquid isomeric with oil of lemon, &c, ob-
tained by distiUing the solid di-hydrochlorate of lemon-oil over hydrate of potassiam
or quick lime. It is transparent and colourless, of specific gravity 0*8569, Tipoor-
density 4*73 (by calculation for 2 voL 4*71) ; boils at 166° C. It resembles oil of lemon
in most of its properties, and in forming a czystallisable compound with h7dzt>ch]o(ne
acid, but differs from it in being without action on polarised light (Gm. xir. 303.)

CXT&XC ACZB. C«H"0' ^ C<H«0«.H*.0*. (Scheele [1784], Opustula ii 181.
— Berzelius, Ann. Chim. xciv. 171; Ann. Ch. Phys. lii. 424, 432; IzriL 303; hex.
215.— Robiquet, iind. Ixv. 68— Liebig, Ann. Ch. Pharm. ▼. 134; xxvi. 119, 452;
xliv. 67. — Marchand, J. p. Chem. xxiii. 60. — Oahours, Ann. Ch. Phys. [3] ^^
488.— Pebal, Ann. Ch. Pharm. Ixxxii. 78; xcviiL 67. — Grm. xi. 436. — Gerh. ii. 85.)
— The existence of a peculiar organic acid in the juice of lemons and of oranges has
long been known, but the discovery of the separate identity of this acid, and its dis-
crimination from tartaric acid, was first effected by Scheele in 1784, who gare to it
the name it bears.

It is to the presence of citric add that a great many fruits owe their additj. This
acid occurs in the free state in oranges, lemons, dtrons, tamarinds, cherries, cur-
rants, gooseberries, raspberries, strawbmies, whortleberries, and a great many others.
In some of them it is associated with malic and tartaric adds. It is also contained
in seyeral tabers and bulbs, such as the potato and the onion. Occasionally it oecnn
AS acid potassium or caldum salt

Preparation, — The raw material for the production of dtric acid is lemon juice.
The juice is made to undergo an indpient fermentation ; it is then filtered and
neutralised, first with chalk and afterwards with quick lime, by which an insoluble
citrate of calcium is formed: 10 pts. of this salt are carefully decomposed by a cold
mixture of 9 pts. sulphuric acid and 66 of water ; the gypsum is washed with coW
wat^T ; and the filtrate and wash-water are boiled down in a leaden vessel over the naked
fire until the liquor has the specific gravity 1*13, then concentrated over a water-bath
until a saline film begins to form, when the Liquid is immediately cooled to the crystallis-
ing point ; if it were further concentrated, the excess of sulphuric add would convert
the residue into a black mass. The cxystals formed are purified by four or fiverecrvs-

CITRIC ACID.

995

taHisations, and the mother-liquors are ntilised for the preparation of citric acid by
treatment with chalk, in the same manner as the fresh lemon juice. In the south
of France, the citrate of calcium is bleached with chloride of Ume, prior to its decom-
position with sulphuric acid. €K}0!^ lemons yield about 6^ per cent of the crystallised
add.

The raw material generally used in this countzy for the preparation of citric acid
on the large scale, for the use of calico-printers, is a black fluid, like thin treade,
which comes from Sicily, and is obtained by inspissating the exj^ressed juice of the
lemon after the rind has been removed for the sake of the essential oiL ( Urt^s DiC"
twnary of Arta^ Manufactures and Mines, L 690.)

Citric acid may also be prepared from goosebories. Tilloy (J. Fharm. xiiL 305)
expresses the jmoe of the unripe berries ; leaves it to ferment ; distils off the alcohol
formed ; filters the residual liquid ; and treats it with chalk in the same manner as in
the preparation of the acid from lemon juice. 100 pounds of gooseberries give 10 pounds
of spirit of specific ^yity 0*928, and 1 pound of crystallised citric acid.

Properties. — Citnc acid crystallises in two forms. A concentrated solution deposits
by spontaneous evaporation, large, transparent, colourless prisms, having the composi-
tion C*H'0' + H'O ; this is the ordinary commercial acid. The cryiritalB belong to
the trimetric system, and generally have the faces oo P . j^ oo . P oo predominant^ also
with 00 j^ oo; the face 2l* oo likewise occurs together with t oo, and sometimes without
itb P also not unfrequently occurs subordinate. Batio of brachydiagonal, macrodia-
gonal, and principal axis » 0*6068 : 1 : 0*4106. (Kopp's KrystaUographie, p. 264 ;
see also Gerh. ii. 88.) The ciystals effloresce in the air between 28° and 60° C,
and lose their water of crystallisation at 100?. A boiling concentrated solution of •
citric add allowed to cool, deposits crystals of a different form, which, according to some
chemists, contain 2CH.H)' + H'O ; according to others, this water is only mechanically
mixed.

Citric add has a strong, but pleasant, addity, in which respect it differs from tar-
taric add, the addity of which is accompanied by a somewhat bitter taste. This dif-
ference is still great^ in the salts.

Citric add is soluble in 0*75 pts. of cold and in 0*5 pts. of boiling wcttw. It is
readily soluble in alcohol, but insoluble in ether.

Citric acid and its potassium-salt are used in medicine. It is also used in the pre-
paration of effervescent summer beverages. Its most extensive application is in dyeing
and calico-printing ; for certain of the finer colours, it cannot be replaced by less costly
adds.

When lime-water is added to a solution of citric add, a slight predpitate is fbrmed,
if the solution is concentrated and the lime-water present in ^reat excess. But if the
mixture be boiled, a considerable predpitate of citrate of calaum is formed, which re-
dissolves as the solution cools. By this deportment, free dtric add is easily detected.
It is distinguished from tartaric and racemic adds by the fact that its potasdum-salt
is soluble.

JkcomposUions. — 1. Solution of dtric acid, when kept for some time, becomes covered
with fungi.-»2. An aqueous solution mixed with chalk and exposed for some time to a
temperature of 20° — 30° C. in contact with a little yeast, yields acetic and butyric acids.
According to How, when exposed in contact with putrefying curd and a base, it fer>
ments and becomes converted into acetic and propionic adds. — 3. When dtric add is
heated in a retort, it first melts in its water of crystallisation and then boils, giving off
the water, which condenses in the receiver. Afterwards at about 175° C. vapours of
acetone distil over, and a copious disengagement of carbonic oxide takes place. At this
time, the residue in the retort consists ofaconiticacid. If the distillation be con-
tinued, carbonic add is ffiven off and oily stris begin to appear in the neck of the retort,
which solidify to crystaJjs of itaconic acid. If these last crystals be repeatedly dis-
tilled, an oily mass of anhydrous citraconic acid is obtained, which no longer solidi-
fies. These decompodtions of dtric acid are thus expressed :

C«H«0»

Drj citric
acid.

C«H«0«

Aconitic
acid.

C»H«0*

Crrstallised
IUcodIc
acid.

- H«0

- C0«

- H«0

38 2

Aconitic
acid.

C*HW.

Crygtallitod

itaconic

add.

C*H*0«.

Citraconie
anljydrido*

The acetoDe and Cftrbosic oiido oliierTed in on eariier itan of the decookpoaition
KK probaUj' due to a secondury decomposition of aconitic acii^ tboa :
CH-O* - 2CO* + CO + CH*0.

Heated irith pumice, dbric acid girm off carbonic anh^dridaat 153° C. — I. Fused vith
polaih, citric acid ia decompoaed into oxalic and acetiii adds :
CH^' + HK) - CHK)' + aC^-O'.

6, Wben cilric acid is treated mth strong tutphurie add, a disengagement of earbonie
oxide ensues, evcD vitbout the application of heat. But if tJie t^unpeiBtnre be rsiivd.
the odour of acetone is peiceired, and carbonic anhydride is given o£ On adding
curbonste of eodium to the reeidual liquid diluted with water, a broon reainoiu man
is precipitated, and the lolutioa contains the sodium-saltof a peculiar acid, which does
not precipitate baryta or etrontia. — 6. Citric acid ii not attacked by dilnte tiitrit
acid; but if heated far some time with Strang nitric acid, it jields oxalic and carbonic

If a huge exe«es of the penuanganafii be used, otliar prodaeta are likewise fbmied,
Damelj, a body which atroogly irritates the eyes and respiratory organs, redoeaa per-
manganate of potassinm at eonimcn tempenttnrea, and is turned brown bj alkalis, pro-

'COiide of manganese acts in the same way as the permanganate. (PAan Ao

bably therefore acrolein, blether with an add closely analogons to acrylic add. Fiuply

'iTided peroxide of manganese acts in the sam " /r,, .

"" 8, Ann. Ch. Phyii. [3) Iv. 374.)

8. dUoritie acts bat feebly on citric add. When a layer of concentrated aolotiini of
citric add is exposed to the sonligM in a large globe filled with chlorine, the gaa ia
elowly abaorbed, and an oil gradually separates, which nAer rectification is coloarieas,
has a sweetish burning taste, and a peculiar odour. It boils at 200° — 201° C, and
does not solidify at U". It reddens litmus paper only afUr prolonged contact. Plan.
tamoui, the discoverer of thia body, assigns to it the formula C*G1"0'; whm it is
agitated with wafer and cooled to + 6°, a mam of crjrtals is formed, CKn"0'.SH^,
miich melt and give off their water at 16°. The oil is attacked by potash, with tur-
mation of a body. CK^I'KV*. Sladeler considers the oil lo be hexachlorinated
acetone (TCl'O (p. 3D), and tha crystals to be a hydrate, C^n•0 + H<0. l4Unait
ascribes to the ail the formula C%1"0*.

9. The action of chlorine on dtrate of sodium, though not very energetic em in
mnshine. is different. Carbonic acid is disengaged, and the liqoor becomes miU^ from
formation of an oil; at the same time, an acid citrate of sodium is formed, wiueh twja-
tallises in stellate groups. Tbe odour of the oil, at Stet swertish, becomes gradually
more acrid. It is a mixture of seTeral bodies. On rectification, chlorotonn flnt distill
over at 64° — 68° C; the boiling point then rises to 188°^I90°, and remains constant
for some time : it then rises to 200°, at which point the oil produced by the free add
distils OTer. The intermediate product, on rectificatian, boils at 190°. It is a coloniieH
and very flnid oil, of specific ^rity 1 '06, with a burning tast^, an extremely irritating
odour, and exciting tears. It has the formula OCP'O*. The action of alcoholic
potHsb on this oil yields chloride of potassium, and a Teiy soluble potasdum^alt
which crystallises in satiny scales; it has the farmuLi C%1'K*0'. The same salt is
produced by the action of potash on the ail from the &flfl add. A, corresponding
silTer-salt ia very unstable, and is readily reduced to the metallic state even in the cold-
The potassium-salt has the composition of that of a cblarinat«d succinic acid. Tie
mother-] tquor &om which the chlorinate oil has been dopoeited contains, besidea
chloride of sodium, the sodinm^olt of sn add which has the composition of suodnic
add but ^)pean to be only isomeric witli it.

10. When htondm is pwlually added to solution of citrate of potasaiuin, a brisk
disengagement of carbonic acid takes place ; and if the addition of bromine be continued
ns long as gas is girpn off and the excess of bromine careftitly t«inored by potash, an
oil ia precipitated which ia a mixture of two bodies. The most volatile at these is
bromoform, CHBr". The otberhasreceivedfrom CabouTB thonamo bromoxaform.
It consists of lustrous silky needl™, which by spontaneous evaporation oystalliae in
large colourlese plates. They melt between 74° and 76° C, bnt are gradually deeom*
P« "■ ' '

CITRIC ACID. 997

pionie nad) : it is decompofled by potash, with formation of bromide of potassium, oxalic
acid, and bxomoform:

C«HBrH>« + 2KH0 - 2KBr + C»H*0« + CHBi*.
Bromoxmfonn. Ox«tIe Bromoform.

acid.

11. Dried citric acid in contact with pmtaokloride ofphovphonu^ becomes heated, and
yields oxychlorooitric acid and oxjchloride of phosphoms :

C«HH>» + PCI* - C«HH)K)l« + POa*.

If the mixture be heated, hydrochloric add is CTolved, and chloride of citryl appears
to be formed :

c«Hwa« + pci« - cra»OK!i« + poa« + hci + hk>.

Chloride of
dtryl.

If the heat be continued, the liquid assumes a deep cheny-red colour and then appears
to contain chloride of aconityl:

c«H»0H}i« + pci» - c«H«o«a» + poa« + 2Ha

Chloride of
■eonitjU

CMtmtes. Citric acid is a strong acid. It reddens blue litmus papier and expels
carbonic acid from carbonates. An aqueous solution dissolTes zinc and iron, with dis-
enfinigement of hydro(|en.

Citric add is tribado. It may be derived from 3 at. water in which 8 at. hydrogen
are replaced b^ the triatomic radical dtiyl, C*H*0^ It therefore forms three series
of salts, in which 1, 2, or 3 at. hydrogen are replaced by metal, thus : —

Citric add (C«HH)<)

Add monometallic dtrate (^^'PTJo'

Add dimetaUie dtrate (CraH)«r^/M

Neutral trimetaUic dtrate . . . . . . (C«H»0*rJQ,

Some of the dtrates occur naturally, as dtrate of caldum in onions and potatoes,
and citrate of potassium in artichokes and potatoes. The alValiiie dtrates are xery
soluble ; other dtrates, as those of sinc^ iron, cobalt and nickd are less so, while the
dtrates of the alkaline earths are insoluble. In the presence of soluble dtrates, alkalis
do not predpitate the salts of iron, manganese, or alnminimn. The dtrates decompose
when heated to 230^C., forming empyreumaticmoducts, which haye not been inyestigated.

The following list indudes all tne prindpal dtrates.

CiTSATS OF ALtrMXwiuic. — Insolublc powder when it contains excess of mAta] ;
soluble gum when the add is in excess.

CiTBATB ov Amxoniuil Monammonic Citrate, CfH^(NH^)0'. — Solution
of citric add, neutralised with ammonia, and then mixed with twice as much add as
it already contains, yields this salt by spontaneous evaporation in small tridinic
prisms.

Diatnmonie Citrate^ CfH*(NH*^*0^ oystallises on the evaporation of a solution
of dtrie add which has been saturated by ammonia, in prisms which are anhydrous but
deliquescent.

CITBA.TBS OF Babxux. Tr^harytto Citrate, CH'BaK)^— Citric add added to
excees of bazyta-water throws down fli&es which become somewhat crystalline. White
powder ; dried in the cold, it contains water of crystallisation, which it gives off com-
pletely at 200^ C.

Monobarytie Citrate? — Obtained as a gummy mass by evaporating a solution of
baiytio dtrate in dtrio acid.

A ci^talline dtrate of barium which, dried at 160^ C, has the fbrmula C>*H"BaK>>«,
is obtained by adding tribaxytic dtrate to a boiling transparent mixture of dtrio acid
and chloride of barium, as long as the resulting predpitate redissolves, and then allow-
ing the mixture to cool It appears to be a double salt of tribarytio and dibaiytic
ntzate.

^ Citrate of sodium is predpitated only by a lar^ excess of chloride of barium : hence
dtrate of barium must be somewhat soluble in atrate of sodium.

CiTBATB OF Cadhium. — Crystalline sparingly soluble salt
CiiBATBs OF Calciuk. Trioalcic Citrate, C^»Ca»0» + 2HK).— When

38 3

998 CITEIC ACID,

chloride of caldnm u aradnallj added to a solution of citrate of sodium, the pneip-
tate at first fonned redissolves, but when agitated, it suddenly forms a magma vhieh
becomes ciystalline on the application of heat. The salt is more soluble in cold thas
in hot water, so that a cold solution becomes turbid on being boiled.

Dicalcic Citrate^ O'H'CaK)' + HK). — Obtained in shining lamine by djanhing
the preceding compound in excess of citric add, and eTsporating the solution.

CiTRATB OF Gbrivil — ^Whitc insolublc powder, obtained by double deeompoa-
tion of alkaline citrates and cerous salts.

C1TBA.TB OF Cobi.lt, C*HK7o*0^ + THK) ^The solution of carbonate of coUt

in warm citric acid, solidifies on cooling, after adequate evaporation, to a lOse-coIoaRd
magma, which dries up to a powder of the same colour.

GuPBic CiTBATB. — Obtained in microscopic rhombohedra by heating a lolTitigs
of cupric acetate with citric acid. The formula is (>H•Cu•O^CuHO + H*0.

C1TBA.TB8 ofIbon. Ferrous Citrate. — ^Alcohol precipitates white flakes of
triferrous citrate from a dear solution of iron in dtric add.

Ferric Citrate, — Freshly predpitated hydrated ferric oxide dissolTes in wann
aqueous dtric add, forming a reddish-brown liquid which on eraponition leave t
light-brown film. It is administered medicinally under this form. Ferrocranide d
potassium does not predpitate an add solution of ferric citrate, but forms a bme liquid
which is decolorised by ammonia.

AmmoniO' ferric Citrate. (Ammonio-dtrate of iron.) — ^When 2 pts. of fredily
predpitated ferric hydrate are dissolved in 3*pts. of citric acid, the solution satnnted
with ammonia leaves on evaporation a greenish-yellow mass, insoluble in strong akohol,
but soluble in aloohol of 40 per cent.

CiTBATB OF Lithium. — Amorphous, limpid, hard massi

CiTBATBs OF Lbad. Triplumbic Citrate, C«H*PVO» (at 120° C), is bat ob-
tained by predpitating an alcoholic solution of plumbic acetate with an aleobolie
solution of dtric add, and washing the predpitate with alcohol; it is granular vha
hot solutions az^ employed.

Diplumhie Citrate. OH«PbW + H»0.— A solution of acetate of lead is added
to a boiling dilute solution of dtric acid as long as the predpitate redissolTes. On en-
pora<ing the dear solution, the salt crystallises in suLall prisms. Ammonia diaolTes
this salt, and the solution afterwards deposits triplumbic dtrate.

Tetrabaeie Salt. — By digesting triplumbic dtrate with ammonia, BeneliM ob-
tained a heavy white powder, which had the formula C«H»Pb«0'. PbHO, or C«5»iV0".
PbO + HO). The triplumbic dtrate digested with excess of subacetate of lead, gave
an insoluble amorphous powder, which had the formula C*H*PbH)'JPbHOJV0 (of
C»*J3*PA»0".3P60 -I- HO). Hddt obtained a salt of the formuU 2(C«H*PbK)'JV0)+
3HP0, or C^^B^Pt^O^\2PbO -h ZHO, by digesting triplumbic dtrate with ammom* for
two diays in a dose vessel. Bulky, white, insoluble powder

CiTBATB OF Maonbsiuic. C«H*MgK)' + 7H«0.— Carbonate of BMgnesinmdi^
solves in dtric add to a solution which forms a thick magma when concentrated. Alcohol
precipitates the salt from its aqueous solution.

This salt, evaporated with excess of citric add, yields a gununy mass, which doei
not become ctysteUine.

When carbonate of magnedum is digested with disodic dtrate, the filtered solation
on evaporation leaves small crystalline groups, which contain sodium and magnesiunL

CiTBATB OF Manoanbbb. C^«Mn*0' + HK).—Citrate of sodium does not
precipitate manganous salts ; but when carbonate of manganese is digested with atnc
add, the above salt is obtained as a white insoluble ciystalline powder.

CiTBATBS OF Mebcubt. — Citric acid precipitates from mercurout acetate, avhit*
powder soluble in nitric add.

Freshly precipitated mercuric oxide dissolves in hot citric add, and the solntion on
cooling depodts a white powder, which is decomposed by water,

CiTBATB OF NicKBL. C«H:»NiK)» -»• 7H«0.— Oxido of nidtd dissolves in citric
acid to a green liquid, gradually changing into a green jelly, which on evaporation
leaves an oUve-green film, soluble in water but precipitated by alcohol.

CiTBATBS OF PoTASSiuK. Tripotassic Citrate. C«H»K»0' + ffO-^
solution of carbonate of potassium neutralised with dtric add, yields hr spontaneons
evaporation, transparent, stellate-grouped needles, very deliquescent, ana ina(dttble in
absolute alcohoL They lose their water of crystallisation at about 200® C.

Dipotaesic Citrate. C«H«KW.— A solution of 2 pts. of citric add neuttalif^
with carbonate of potasdum, and mixed with I pt of dtric acid, yields by eTsporatiw
an amorphous mass having a sour taste.

CITRIC ACm. 999

Monopoiatsie Ciirate. CH'KO* + 2BP0.— 1 pt of citric acid is neutralised
with potash, 1 pt. of citric acid added, and the mixture eyaporated at 40^ C. Large
transparent prisms, permanent in the air, and haying an agreeable sonr taste. Thcj
melt in their water of crystallisation, and giye off 13*8 per cent of water, forming a
yiscons liquid, which solidifies on cooling to a concentric radiated mass of ciyst^s,
consisting of C«H^£0^

Ammonio^potaisie Citrate, C*H*K'(NH^)0^ — A solution of dipotassic citrate
neutralised with ammonia, yields this salt, on eyaporation, in transparent deUqueecent
prisms.

Potassio^antimonic Citrate, — 1 pt of dtric acid is neutralised with potash;
1 pt more of acid added ; the mixture boiled for some time with trioxide of antimony,
and the filtrate left to crystallise. White, shining, yeiy hard prisms, grouped in tuft^.
They giye oflT 6*7 per cent of water at 190° C. Hay be regarded as a double molecule
of tripotasdc citrate, in which part of the potassium is re^daced by the tribasic radicle,
antimony: C"H»*(K»Sb'^0".

OiTBATi OF SiLysB. C'H'Ag'0^ — Citrate of potassium added to solution of ni-
trate of silyer, throws down this stdt as a heayy white powder, which crystallises firom
boiling water in white or yellowish needles. Pefiagrates at a high temperature.

A rgentouB Salt, — The aboye salt heated to 100° C. in a current of hydrogen, is
changed into a dark brown mass, which is a mixture of citric acid and triargentous
citrate. Water extracts from this mass first citric add, and then a small quantity of
argentous salt with a red colour. This red solution heated to boiling, assumes a green
and blue colour, then deposits metallic silyer, and becomes decoloriseid.

CiTBATBB OF SoDiux. TrtBodio Citrate, 2fC^»Na»0') + 11H«0.— Wben
a solution of citric add is saturated with soda, and the solution left to eyaporate,
large rhombic prisms are obtained of this compodtion. They quicUy effloresce and
are sparingly soluble in aloohoL At 100° C. 7 at water are giyen o£^ and at 190° —
200^, 4 at more. A solution of this dtrate eyaporated at 60° C, yidds monodinic
dystals containing only 2 at water.

Dieodie Citrate, C*H*Na*0*.H*0. — Obtained like the ooiresponding potassium-
salt Prismatic, stellate-grouped crystals, which giye off their water of ciystallisation
when dried oyer oil of yitrioL

MonoBodie Citrate, CHITaO* + H*0. — Obtained like the corresponding po-
tasdum-salt A y ery concentrated solution left to eyaporate in a warm pliuse, solidifies
to a mass of adcular ctystals, and crystallises to the laist drop.

AmmoniO'Bodic Citrate, — Confused crystalline crust.

PotaBBiO'Bodic Citrate, C«H»NaK)».C^»K»0» + 11HH>— Obtained by dissoly-
ing equiyalent quantities of trisodic dtrate and tripotassic dtrate, and concentrating
by eyaporation. It is depodted after some days in radiate-grouped, lustrous needles.

CiTBATB OF Stbovtiux. — Stroutia-water is predpitated by dtric add in thick
white flakes, which, after drying oyer oil of yitriol, haye the compodtion C'H'Sr'O' +
HK>. They lose their water of crystallisation at 210° C.

CiTBATB OF Ziirc. C*H*Zn*0* + WO. — Carbonate of dnc dissolyes readily in
aqueous dtric add ; on boiling, the salt is predpitated as a granular, crystalline powder.

The aqueous solution of this salt mixed with a small quantity of dtric add, and
eyaporated at a gentle heat, depodta transparent crystals, which haye the compodtion
C«H»Zn»0».C«H&«0» + H«0.

SubetiiuHon-deTivaHve of Citric Acid,

OxTCHLOBOCiTBio AciD. C«HK!1«0« » (^*^'^*j^]I|q1*.— Whenpentachloride

of phoAphorus is mixed with dry dtric add, the mass becomes heated, liquefies, and
then solidifies to a magma of crystals which consist of oxychlorocitric add mixed with
oxychloride of phosphorus. The latter is remoyed b^ digestion with disulphide of
carbon, tiie mass is thrown on a filter, and washed with £sulphide, then pressed be-
tween bibulous paper, and dried in a current of hot air. li forms coburless silky
nABdles *

CTBPO' * fa* - c«HK>KJi« + poa*.

In moist air or in wat«r, this add becomes heated and is oonyerted into dtric add.

On heatinff it in a stream of dry air to 100° C, hydrochloric add is liberated, and the
residue consists of aconitic add. Dry ammonia acts yiolently upon it, forming a black
yesicular mass. In contact with aniline, the add becomes strongly heated, and yidds
phenyl-aconitimide. ^ A.

S B 4

CZ^BXO ACZ9, AKDBa OT. (Pebal, Ann. Ch. Phum. Ixnil. 73 ; zenu.
6T.V— Of tbe unides ofdtric add, bodJ«s derifsd from unmonubj' tlie i^laeoracot of
h^drogBD by the radicla citijt, anl; dtiamide ■■ known ; bat manj of the consqiciod-
iug phenjl-compoanda hftve been ob^ined bf PebaL

ClTBAKlDl. CH^'HK)* ~ H< [V, iM ft c^staHiiM eompomid, ali^itly *iv

labl« in water, obtained bj &» Ktian of al«ohalio ammooia on citnto of methjl or
dtrata of ethyl

(CHK)')-)
PktHgleitrattid*. Oiirintilidt. (CS.'HS', i* obtained b; the uAioa of h«at

on tri[dMnjlainio dtrata ;

CE^CHTW)' - 8HK) - C-S'-SH):

TiipbMirluDlc dcnu. Plien jlcltniBkla.

To prepaTS tbis bodj, the yellow powder l*ft on beatjng triphenylumc dlrate ii dti-
•alvea in boiling alcohol, and the solnlion i« decolorised bj animal diarcoaL On eooliiig
two acta of crrBtala mn deposited, hexagonal pUtsa and floe priams. The former oottnt
of phenyldtTimiiie, and are diaaolTed ont by boiling w)|^ alkali, which doea not nvr-
eeptibly affect the phenyldtTamide. Fhenyldtramide ia depodted fitnu aleolxri in
coloarieaB priama, tnmeated longitudinarily, and with a nacreona Inatn. NeDtral to
Tegetable eotonre.

PttngUitriiHidt. CUrMtmO. C"IPH»0* - (Cff)'lN',repr»Bant» dlpheDj-
Luoio dtiate ninui S atom* of water:

C•H^OWN)'0' - SffO - C^fNK)'.

It ia obtained it) tlie [nparation of phenyldbamide ; alao bj heating phenyldtnmic
acid with phenytamine :

■_CS7S - C"H"1P0' + H*0.

dtrlmUa.

PiinyloUramie Aeid. OOraKilio Jeid. CWN0'-^t(™'XCfH^<)-tQ _
Obtained by the actios of heat on monophenjUnuo dtrato :

C'H'(C'HT()0' - 2HK) - CE'iNO".

UuDOpliinrluBk Phmjl-

Honophenylamic citrate ia heated to 140° — 150°C. ailongaa water ia given off- Oa
ooolins. the neidae beeomca eryatalline. It diuolTea readily in water, airi if excev of
phenyTainine has been avoidai, it ia depodted in emaU oyatalline aidiFrtila, or in
mamilLuj gronpa of imall prisma. It hai an acid reaction, and fbrma etyitaQine nlta
with diver and with aniline.

On beating it with pcntachlorids of phoaphoroa, hydioeUorio add is given oir,
and a liquid formed, which appesn to contain ehloride of aamilanyl, C'*NHK)'.CI, as,
when treated with water, it is resolved into hydrochloric add and ^tenylaeonitamic

Diphettyleitramia Aeid. CUrebuatdie Acid. C"H"N*0*. — ^Obtained in tha
form of an ammonia-salt by boQing phenyldtrimide with ammonia By adding hydro
cMorie add to the solntion, the add is predpitated. BecmtalliBed trrm alcohol, it
forms saft,concentricall;-^nped,ailkynFedleB. It melta ftod give* offwatei atlfi()°C,
and beeomee reconvertfld into phenjlcitriraide.

Diphe^lcitramie add eontaine the dementa of dipheaylamia dbata mhhu S aL
water : (?H'^^N)'0' - 2EK) - C"'H"lW>', and may be represented by the

fbrmnla (OWO')-('^ derived &om the mixed type IPH'.HK). E. A.

O^TBZC Tg— >■ The d&io etharl represent dtriesdd in which one or mo™
atoma of hydrogen an replaced by alcohol-radicka. Thoee tn whieh one or two
atoms of hydrogen are thus replaced lure add propeitiea.

CITRIDIC ACID— CITROMANNITANS. 1001

Ik
1

CiTBATB OF Ethtl. CiMo Ether. [^^^^ {o*. (Th^nard, M^m. d'Ar-

CiTBATi OP Mbthtl. Trtmethylio Citrate. C»H'W - ^^ct^"^*^! ^'•■~"

A solution of citric acid in wood-spirit is saturatfid with hydroehlorie acid gas ; on recti-
fying the mixture, chloride of methyl and the excess of wood-spirit pass ofi^ and a
eolonriess liqnid distils oyer at about, 90° C, which is citrate of methyl. After standing
^^ some time it ciystalliBes. (Saint- Eyre, Oompt rend, xxi 144.)

Bt: Monomethyloitrio Aoid, ^-m nm [ 0', and IHmethylcitrie aeid, V^ /nm\s ( 0',

ate both formed in the preparation of citrate of methyL They haye been but little
examined. (Demon desir, Compt rend. xTxiii. 227.)

caeil, ii. 12. — ^Malagnti, Ann. Ch. Phys. bdii. 197. — Bum as, Compt. rend. yiii. 528. —
Harchand, J. pr. Chem. xx. 318. — Heldt, Ajin. Ch. Fharm. xlyii* 57. — ^Bemon-
desir, loo. eit.)—T}as body is formed by distilling a mixture of sulphuric acid, citric
acid, and alcohol; but the best method of preparing it, according to JDemondesir, is as
follows: A solution of citric acid in alcohol is saturated with hydrodbloric acid gas,
the liquid neutralised with carbonate of soda, and agitated with common ether, which
dissolves out the citric ether. On eyaporating the ethereal solution, citric ether is left
as an oily, yellowish, transparent liquid, with an odour resembling olive oiL Its spe-

^'^ cific gravity is 1*142. It is very soluble in alcohol and in ether. It boils at 280^ C,

but decomposes — probably into aconitic or citraconic ether. It is decomposed by free
alkalis into citrates and free alcohoL With ammonia it yielda, besides dtramide,

^ several products which have not been examined. £. A.

Syn. with Aoonrno AotD.
SeeCiTBSini.

A glassy variety of quartE having a wine-yellow colour.

OITSXV8. Oitroglyeerma. OUrutee of Glyceryl, (van Bemmelen, J.pr. Chem.
g Ixix. 84.) — Two of these compoonds have been obtained by heating cilxie add with

glycerin.

Neutral Citrate of Glyceryl, C»H»«0» - ^^^^H*^**!^* " prepared by heat-

mg dtric add with a sliffht excess of glycerin to 160° — 170** 0. fbr twenty hours,
"miter then escapes, and were remains a hard, light yellow, transparent mass, from
*' which the pure poduct may be obtained by boiling out the excess of s^ycerin with

alcohoL It is difficult to pulverise ; insoluble in water, alcohol, and etner. Hydro-
f chloric add dissolves it gradually with aid of heat; sulphuric add immediately, with

I blackening. It dissolves gradually in cold potash-ley, and when boiled with bases, is

quickly resolved into dtric add and glycerin. The formation of the compound is re-
presented by the equation :

C*H»0» + C«BTO» « C^"0» + 8H:»0.
Citric Mid. Gljecris.

Basic Citrate of Glyceryl Citrodiglyeeride, C»«H>«0»» « C»H'«0».C«H»0»,

«rw^io) X

may be regarded as a double molecule of glycerin f ^ ( 0' j, in which 3 at hydro-

(C«H»«)'» )
gen are replaced by dtryl, that is to say, as (C'H^O^y^O'. — Obtained like the pre-

H» )
ceding, by heating dtric add with a double quantity of glycerin. The mass melts at
100^ G., and the transformation is completed between 160^ and 170^. The product
purified by boiling with alcohol, is yellowish-brown, somewhat darker and less hard
than the neutral compound, which, however, it resembles in other respects.

OXTROOSRZO and CXTSOauO AOZB8. Two adds said to be contained in
the sediment of lemon and bergamot oils; the former is waxy, the latter oHy. (My-
lius, Arch. Pharm. xxxii 28.)

emL/omUkSKZLm Syn. with PHEmnxTnoiaDB (p. 998).

CXTXOO&TCBSnr. See Citbins.

l« (y. Bemmelen, Jahresber. d. Chem. 1858, p. 485.) —
This term is applied to two compounds derived from mannite in the same manner as
the dtrins are derived ftx>m glycerin. They are formed by heating dtric add with
mannite in proper proportion to between ISO*' and 140^ C, combination then taking
place, attended witn elimination of water.

A. htii, light jeOaw, tutelesa HDlMtaiice,iiuolable in eold nba, ileobiA, and «tliv.
decomposed by long boiling with mlar oi ikohol, kIio bj alkilis. Between 170° and
180° C. it toitu brown and decompoeeiL

DMlronannitan. CH-O"- (CH-OTJO* t- 2HK).— Obtained aa ■ hy-

(CTI'O')'-^
drate br heating 3 aL citric vid and 1 at. mannitefor eometimeto between 110° and
150° C The product ia a dry. hard, tight yellow mil an, which haa no acid reactioD.
diaBolree in water oidj after long boiling, a etailj dMompoaed bj alfcalia, and doc*
not gire off water without decomposition when heied.

CxnUnr, O^ or. See Citbdb taowi. (p. 1004).

CTtMOwn^ The name applied bj Slanchet and Sell to that eonatitnent of
lemon-oil, which fbrma a eTTstaUiaable eompoond with h^dioehknic acid (p^ IDOl). It
ia aometimea also applied to the triatomic radicle of dtnc acid.

CXnUWl'MHA- The camphor or atcuopteiie of lenios-oil (p. IQ04).

tSITMiVW. A genus of plants beloDging to the natnral older Aio^niiaeiM, and
mcloding the orange, lemon, citnin, ahaddoi^ &c Tbey alt prodoce juicy truita oon-
taining citric acid, and enclosed in a thick fle^j rind coDtaimng -roUtile oila, vludi
are isomeric with oil of turpentine, but differ bun one another in odoor, densi^, ac-
tion on polariaed light, &c

CiTHUB Adiaittiuii. The fliMd Oranfft. — The rind of this fruit ""t*'™ ■
volatile oil, Oii of oramgt^piA, OltUM eortieum amrantiomm, which mAjbs extnded
by pressure or bj distillslion with water. It has the same compoeition and Taponr-
denaitf as oil of lemon. Spedflc gravity in the liquid state 0'83 — O'SS. Boiling
point 180° C. It is nentral, and baa an agreeable odour. Optical rotatoiy power,
laSflO — 127*° to the right. It diaaolTes completely in abeolnte alcohol, and with
turbidity in 7 — 10 pta. alcohol of iroccifie parity 0 85, It nnit« with hydrochknie
add, forming a liijaid compound. C"H".HC1, and a solid compound, C"H''.2HC1,
which roeltfl at 60°C. (Qm. iIt. 306.)

Orange-peel also containa, especially in the onripe state, a biUn jaincifde caDed
AnrantiinovHesperidin (;.tr.)

The juice of the orange contains citric and malic acids, partly ft«e, partly eomtnnad
with basM. The juice of sweet oranges likewise contains grape-sugar or cane-mgar;
the grape-mgar predominatee in the onripe Btate, but does not sensibly inorawe is
qoanti^ as Uie uuit ripens, while the amount of cane-sngar increases, both abaolntely
and reUtiyoly to the weight of the oran^, the juice, and the aoUd coostitnenta (Ber-
thelot and Buignet, Compt. rend. li. 1094). 100 pte. of oranges contain 4-2 pa
cent cane-sugar, 4-3 grape-sugar, and 0'4$ free add (Bnignst, Ann. Ch. fliyn. Ill
233). The pips of the orsnge contain a bitl«r substance, which appean to be M"^fr^l
with the limonin of lemon-pija.

The flowers of the orange contain a very fragrant Tolatile oil, called OHqfNtraU,
OleanJIoTvm tiaplia s. tteroli, which is obtained by distilling the flowers with Wats'.
When recently prepared, it ia nearly colonriess, but reddens quickly on expoauiv to

Sht. According to Soubeirsn and Cspitaine, it is composed of two oila, one eaaily
ubie in water and reiy Ira^^rant, while the other is sparingly aolnble and has a lena
agreeable odour : the latlsr floatson the watery distiUate, and is easily separated. The
more &agrant oil may be extracted from the watery distillate (oratar-fiomer tMfcr) by
means of ether. It ia reddened by tulpkurie acid, and communicates this property to the
entire essence. A'lfricaci'if colouis the oil brown. According to Dobereiner, oil c^neroli
produces a peculiar add in contact with p/adnun-i/ocir. Oil of neroli dissolTee clearly in
1 3 pta. mcoJvd of §pecific grartty 0-Bfi, and with turhidi^ in a larger quantity. Ac-
cording to Boullay and Plisson, alcohol of 90 per cent- aepsratcs from oil of neroli a
solid Bubstance, neroli-camphor, melting at 60° C. ; insoluble in watrr. sparingly
salable in boiling absolute alcohol ; very soluble in ether ; it appears to contain 83'76
per cent. C.lfi-Oe H, and 1-15 O ; probably a hydrocarbon when pure. (Qm. ziv. 386 ;
Gerh. iii. 630.)

The leaves of the orange yield a watery inhsion characterised by a bitter ai«nwtic
taste.

if Tsrions parts of tb*

CITRUS BERGAMIA— CITRUS LIMONUM.

1003

Ash of Orange-tree,

RowNBY and Blow.

RicBAaoaoN.

Aflh, per cent,

Root.

Stem.

Leaves.

Fruit.

Plpt.

Fruit.

4-48

2-74

13-7

8-94

3-3

—

Potash ....

15-4

11-7

16-6

36-4

403

38-7

Soda ....

4-5

1-7

11-4

0-9

7-6

Lime ....

49-9

66-6

56-4

24-5

190

23-0

Magnesia

6-9

6-3

6-7

8-0

8-7

6-5

Ferric oxide .

- 10

0-6

0-5

0-8

mm^

Sulpliuric acid (anhy-
drooB^

6-8

4*6

4-4

3-7

2-9

Silicic acid (anhydrous)

1-7

1-2

4.8

6-2

PhoBphoric acid „

13-5

171

3-3

11-1

23-2

14-1

Chloride of sodium

1-2

0-2

6-6

3-9

6*8

trace

Ferric phosphate .

—

^—

—

1-7

CiTBUS BsKOAHiA. Tke Bergamot. — The rind yields by pressure a yolatile oil,
C^H", which deposits by keeping, a solid camphor called bergaptene, haying the
composition CH*0. (See Bbboamot, Oil of, p. 580.)

CiTBUs BioABADiA. The Bigarade or Bitter Oranae (Bigaradier of the French,
Mdanaolo of the Italians). — ^The rind of the fruit of t£is pUnt vields by pressure a
Tolatite oil, C**H", commonly called Oil or Essence of Mandarin (^though the mandarin
orange is a variety of Citrus auranUum), After filtration, it has a pale yellowirti
colour, but after rectification it is colourless, clear, and mobilei Specific gravity, 0*852
at 10^ C, 0*8517 at 12^. Boiling point 178^'. It has an agreeable odour, different
from that of lemon or orange-oil, and a not unpleasant taste, like that of orange-oil.
Optical rotatonr power 85*5° to the right. It is insoluble in loaier^ but soluble in
10 pts. of alcohol, also in ether and glacial ooeHc add, and in all proportions in stU-
phide of carbon. It dissolves bromine, iodine, phos^horuSt sulpnur, oils both fixed
and volatile, toor, and resins, With hydrochloric acid it forms a dystalline compound
containing C**H*'.2HCL Cold nitric acid colours it faintly yellow ; hot nitric acid
decomposes it, with evolution of nitrous fumes, and the mixture, on addition of water,
deposits a nearly solid mass. With alcoholic nitric acid, it forms a crystalline mass,
probably a hydrate. It is reddened by cold sulphtme acid, and carbonised when
heated therewith. (S. de Lnca, Compt rend. xlv. 904. — 6m. ziv. 304.)

The Seville bigarade, or Seville orange, is much used for the preparation of bitter
tinctures and of candied orange^peeL The bitter aromatic principle is a powerful tonic,
and gives its tlavour to the liquid called Cura^oa.

CiTBTTS LixBTTA. The Lime, — The rinds when torn and pressed, or distilled
with water, yield an oil which resembles oil of lemon, and when treated with sulphuric
acid and chromate of potassium, forms limetticacid,C* 'H*0*. (G m. ^. cit.)

CiTBUs LixoicuiL The Lemon, — ^Regarded by many writers ss a variety of
Ciirtts medica.

Lemon-juice contains free citric acid, and is used for the preparation of that acid
(p. 902), also mucus, vegetable albumin, and sugar; according to jBuignet (Ann. Cli.
Phys. [^1 Ixi 233), 100 pts. of it contain 1*1 grape-sugar, 0*4 can&-sugar, and 4*7 free
acid. The nitrogenous matter causes it to putrefy easily, whence it acquires an unplea-
sant smell and taste ; to prevent this change, it is often kept in bottles, with a layer of
oil on its surface.

According to Witt (Chem. Soc Qu. J. vii 44), lemon-jxiice contains from 0*2 to 0*5
per cent ash, consisting in 100 ^ts. of 44*3 per cent potash, 2*1 soda, 7*6 lime, 8*3
magnesia, 12*5 sulphunc anhydnde, 19*7 carbonic anhydride, 7'6 phosphoric anhy-
driae, 1*0 ferric phosphate, 1*2 chlorine, and 0*6 silica.

Lemon-pips contain in the nucleus, citrate of potassium, a fktty non-drying oil, a
tallow-like fat, a bitter principle called Ivmonin, together with other constituents.

In the ash of lemon-pips, Souchay (J. pr. Chem. xxxviii. 25) found 38*2 per
cent potash, 3*5 soda, 12*6 mne, 8*5 magnesia, 0*2 ferric oxide, 34*1 phosphoric anhy-
dride, 3*2 sulphuric anhydride, 2*3 chloride of sodium, and 0*3 silica.

1004 CITRUS LIMONUM.

Oil of ftamoii. — ^Lemon-peel contains a Tolatile oQ, called Oil of lemon, Oleum eUri^
which is extracted by pressure or by distillation with water. This oil is oovapnaed fnr
the most part of a hydrocarbon isomeric with oil of toipeotine, G^*H", and haying the
same Tapon^ensi<T (4*81-— 4*87). It is nentral, and has an agreeable odour. SpeaAe
gravity in the liquid state, 0-84^0-86 (Zeller ). Boiling point 173^ C. (Blanchet
and Sell) ; 176*1^ (Briz). It volatilises in the air at ormnaiy tempeiatitres without
leaving a perceptible grease-spot, provided it has not become zesinoos bj OTidation. It
deflects the plane of polarisation of light to the right.

Oil of lemon, obtained as above, is, nowever, a mixture of two hvdroearbona, having
the same composition, but differing in optical rotatory power and in their behaviour
with hydrochloric acid. These two hydrocarbons may be separated by distilling the
col in vacua The first portions collected at 65^ G. have a density of 0*8514 st 15^ CX,
rotatory power -• -f 66*4^, and when saturated with hydrochloric add gas^yieid a solid
and a liquid dihydrochlorate. The following portions collected at about 80^ d have a
specific gravity of 0*8506 at 15^, rotatory power >- + 72*5^, and are almost wholly
transformed by hydrochloric acid into a solid dihydrochlorate ; they likewise contain a
sensible amount of oxidised oils. (Berthelot)

Oil of lemon dissolves sparingly in water^ in 7'14 pts. alcohol of specific gravity
0*8317, in 10 pts. alcohol of specific gravity 0*85, in any quantity of absolute woho^
and mixes readily with oUa both fixed and volatile. It dissolves sulphur and pho*-
pkoriUt also resins and other bodies.

Oil of lemon when exposed to air and light, absorbs oxygen, with formation of aaoae,
becoming at the same time darker and more viscid, and forming a small quantity of car-
bonic acid ; according to Aschofif, the crude, but not the rectified oil, turns acid on expo-
sure to the air, forming acetic acid and lemon-camphor. At a red heat, the oil is decom-
posed, with formation of tar and charcoal Chlorine decomposes it ; cotton soaked in the
oil and immersed in chlorine sas becomes charred on the surface, but does not take fixe.
When bromine is covered wiSi a layer of water, the water with oil of lemon, and the
whole carefully mixed, the bromine becomes decolorised without explosion, and a bromi-
Aited oil is formed, 1 pt. of rectified lemon-oil taking up 2*28 pts. and 1 pt. of the cmde
oil, 2*4 to 2*5 pts. of bromine (G. Williams, Ohem. Gtiz. 1853, p. 365). Iodine decom-
poses oil of lemon with rise of temperature. Strong nitric acid turns it brown and res:-
nises it ; alcoholic nitric acid converts it into a hy&ate. With strong stdpMirie acid, it
assumes a yellowish brown colour, and yields terebene and colophene ; sunilarlj wi»eii
distilled with phosphoric anhydride. I^mon-oil dropped into a laree quantity of oil of
vitriol ii said to yield sulphoterebic acid (G-er h ardt). Potassium diminates hydrogen
from lemon-oi^ slowly at common temperatures, more quickly when heated, a^i^iV^g
at the same time a brown colour ; after repeated distillation over potassium, however,
the oil undergoes no further alteration, and then possesses a finer odour than before.
Hydrate of potassium separates from oU of lemon a brown substance^ the oil thereby
acquiring a stronger and^ore agreeable odour.

Oil of lemon is largely used in perfumery ; it should not be dark coloured or viscid
or leave a perceptible stain on paper. It is often adulterated with cheaper oils, such
as oil of turpentine or oil of lavender, and sometimes with alcohol. The latter adnltA-
ration may be detected by agitation with water, the pure oil then exhibiting no per-
ceptible diminution of volume. The pure oil is uso coloured brownish by acid
chromate of potassium, whereas if it contains alcohol, it turns greemsh.

The admixture of cheaper oils mav generally be detected by the odour. Oil of tux^
pentine may also be detected in oil of lemon by its difierent behaviour to polarised
light, especially when heated, the molecular coustitution of oil of lemon being much
less altered by heat than that of oil of turpentine. The rotatory power of^£e sus-
pected oil is first to be determined at the ordinary temperature, and again after the
oil has been heated to 300^ 0. for an hour or two. If tne oil is pure, no change will
be perceived, but if oil of turpentine is present, especially the Frendi kind, which is
Isevo-rotatory, the dextro-rotatory power of the oil will be considerably increased by the
heating.

Hydrate of Lemon-'fiil is a crystalline substance isomeric with hydrate of tur-
pentine-oil, G**H*'.2HK), obtained by mixinp 1 pt of lemon-oil with | pt alcohol, of
specific gravity 0*85, and } pt. ordinary nitnc acid, and leaving the mixture to itsdf
for some time. (D e v i 1 1 e.)

Hydrochlorates ofLemon^oil. — These compounds are formed by saturatisgthe
oil with hydrochloric acid gas, also by treating the oil with the aqueous acid. The
compound formed in larg^est quantity is the dihydrochlorate, C"M".2HC1, of which
there is a solid and a liquid modification, the latter being produced chiefly from the
more volatile, the fbrmer fh>m the less volatile portion of the oiL (Berthelot*
frid. sup,)

CITRUS LUMIA. 1005

MonohifdroeldoraU. C**H".HC1. — ^This oomponnd is produoed by satnratiiig a sohi^
tion of lemon-oil in acetic acid or alcoholic snlplmric acid, with hvdrochlozic acid gas,
and collecting the few ciystals which separate, rarely, however, and only under peci£ar
circumstances. It appears also to be present in small quantity in the portion of
lomon-oil which remains liquid after the separation of the solid dihydrochlorate. The
ciystals melt at 100^ C, and volatilise without decomposition at higher temperatures.

JHhydrochlorate. G**H**.2HCL — ^The solid modification of this compound is ob-
tained by passing dry hydrochloric acid gas to saturation into rectified and dehydrated
oil of lemon well cooled, separating the resulting crystals from the mother-liquor, press-
ing them repeatedly between paper, washing them with cold alcohol, recrystauising from
hot alcohol, drying in the air, afterwards in vacuo or over oil of vitriol, and once more
crystallising firom ether (Blanchet and Sell). It forms ri^ht four^sided prisms or
lamiiue, heavier than water; has an aromatic odour ; is insoluble in water, soluble at 14^ C.
in 5'88 pts. of alcohol of specific gravity 0-806 ; and separates from the solution, on ad-
dition of water, in crystalline laminae. On evaporating the alcoholic solution, partial
decomposition takes place. The crystals are also soluble in oils both fixed and vola-'
tile. The compound is optically inactive, melts at 43^ or 44^ C, and solidifies ciy-
staUine on cooung; it sublimes at 60^ C. without decomposition, boils at 142^
(Cahours), at 162^ (Blanchet and Sell), with partial decomposition, hydrochloric
acid escaping and an oil passing over, which does not solidify till cooled to 20^ C
The aystals bum with difilculty when heated in the air. Chlarin^aa converts the
fused compound, with rise of temperature, into a chlorinated compound, C^*(H*^C1').2HC1,
Laurent's hydrochlorate de chhrocitren^e,

Dihydrochlorate of lemon-oil is decomposed by ailver and Tnercuroua salts in the
cold, not by oxide of lead^ even when heated. Nitric acid does not act upon it in the
cold, but diecomposes it when heated, with evolution of nitrous acid. Strongs sulphuric
cCbid decomposes it, separating hydrochloric acid. Potassium decomposeis it, with sepa-
ration of lemon-oil ; if heat be applied, dtrene (p. 992) is produced. The same pro-
duct is obtained by repeated distiUation of the compound with potash or lime, or by
the action of those bases at high temperatures.

The liquid dihydrochlorate, called also hydrochlorate o/dtriUne and hydroehlorate
tf citryl, is contained in the mother-liquor of the preceding compound, and may be
obtained pure by cooling the mother-Uquor to — 10° C. to separate the remaining
quantity of the solid compound, and filtering through a mixture of chalk and animiu
charcoiJ, to remove free add and colouring matter. It is a mobile oil, optically inac-
tive, soluble in alcohol, and precipitated from the solution by water, with loss of hydro-
ehloric acid. By treatment with nydrochloric add gas, it is converted into a crystalline
mass, which dissolves in alcohol, but separates therefrom, not in czystals, but in the
form of a heavy oil, a small quantity remaining in solution.

Lemon'camphor or Citroptsne. — A soUd substance produced from lemon-oil
by oxidation. It is formed when the oil is kept for some time in half-filled bottles,
partly separating in the solid state, while the rest remains dissolved, and may be sepa-
rated by rectifying the oiL It forms colourless volatile crystals, which smell like oil
of lemon, have a sharp pungent taste, are neutral, insoluble in cold water, but very
soluble in hot water, to which they impart a dedded dichroism. It is soluble also in
alcohol and ether, the hot saturated solutions solidifying on cooling. The compound
melts at 46°C. (Mulder), above 100° (Berth elot), hoUa at a temperature above 100°,
and distils in oil-drops, which solidify in the crvstaliine form ; it may also be sublimed.
When thrown on red-hot coals, it^olatilises without taking fire. It dissolves in sulphuric
acid with red colour and peculiar aromatic odour, and water predpitates from the
solution a white resinous substance, which is insoluble in water, and does not melt at
100°. Nitric acid dissolves the camphor, with decomposition at common temperatures^
but gives off nitrous add when heated with it The camphor does not absorb hydro*
chloric acid.

The compodtion of lemon-camphor is not known with certainty. According to
Mulder, it contains 64*8 per cent C, 9*2 H, and 36*0 0; according to BertheLot, 68*0 C,
7-6 H, and 34*6 0.

The term lemon-camphor is likewise applied to two other compounds, viz. the
solid dihydrochlorate of lemon-oil, and the hydrate formed by the action of alooholio
nitric add on the same oiL

CITBT78 LuxiA. The Swret Lemon, — ^This plant, which grows abundantlv in
Calabria and Sicily, yields a fruit very much like the common lemon. The rind yields
by pressure a volatile oil, the greater part of which distils between 180° and 190° C.
yielding a colourless limpid li<^uid.

The portion boiling at 180° is isomeric with oil of turpentine, &o., and has a density
of 0*863 at 18°. It possesses a dextro-rotatory power — 34° for the transition-tint

The acetone sod earboiiie oiido observed in an eariier atage of Ihe dsooraipantini
are probably due to a secandary decampogitioD of aconicic ada, thai :
C^'C - 2C0« + CO + C"H"0.

Heated witli pumtM, citric add giTesoffearbonioanb^drideat 153°C. — (.Fuaedsilk
polaik, citnc acid ia decompoaed into oxalic ajid ocelie acida :
CH'O' + HK> - CHH)' + af^HfO*.

5. When citric add ib treated with strong su/phuric acid, m disengagement of c^rboDie
oxide enau™, even without the application of heat. But if the temperHbur be raised,
the odour of ncetone is perceired, and c&rbonic anhydride is giTen off. On adding
carbonate of sodium lo the residual liqoid diluted with water, a Imnra rreinoas mae*
is precipitated, and the solution contains the sodimn-Balt ot a peculiar acid, which do«

not precipitate baryta or strontia 6. Citric acid ia not attacked by dilate nitric

add; but if heated for soma time with strong nitric acid, it yields oxalic and cartuiuc

7. Citric add ia eaailj oiidiaed by peitiuniffamc add, A solution of citric add
mixed with aulpburic add doe* not decolonae pcmtanffanalt of polatnu/» in the
cold ; bat at 80° C. the dtric add is oxidiE«d to carbonic add aod acetone :

20^*0' + HKI + O" - CfH-O + 9C0' + 6H'0.
If a laige excess of the permanganaCe be used, other prodncti are likewise farmed,
namely, a body which strongly irritates the eyes and reapiratoiy organs, Tedocea per>
Diangaiiate of potassium at coEumcu temperatuno, and is tuned brown by alkalis, pro-
bably therefore acroldn, together with an add dosely analogous to acrylic add. FinHy
divided peroxide of manganeae acts in the same way as the permanganate. (F^sn da
Saint dillea, Ann. Ch. Phys. [3J It. 87*.)

8. CAZariru acts bat feebly on citriu add. When a layer of concentrated Boliitiaa of
litric acid ia exposed to the Bunlight in a large globe filled with chlonne, the gaa ia
alowly absorbed, and an oil gradu^y separates, which after rectification is colouleai,
has a Bweetiah burning taste, and a peculiar odour. It boils at S00° — 201° C., aod
does not solidify at 0°. It reddens litmus paper only after prolonged contact. PUn-
tamour, the diacoverer of this body, assigns to it ue formula CH]1"0' ; when it is
agitated with water and cooled to + 6°, a mass of crystals is formed, C^"0'.3H'0,
i^ch melt and giro off their water at IS°. The oil is attacked by potash, with f<n^
mation of a body, C*C1<K*0*. Stsdelei considers the oU to be hexachlorinated
acetone C%1*0 (p. 30), and thn crystals to be a hydrate, CH3>0 + H*0. Imnot
ascribes to the oil the formula CCl'*©'.

6, The action of chlorine on dtrate of sodium, thongh not very energetic eren ia
Bunshine, is different. Carbonic acid is disengaged, snd Uie liquor becomes milky bom
formation of an oil ; at the same time, an acid citrate of sodium ia fbnned, which em-
talliaes in atellate groups. The odoor of the oil, at flist sweetish, becomes gradn^W
more acrid. It is a mixture of several bodies. On rectification, chloroform fint diatiu
over at 61° — 66° C; the bailing point then rises to 18S° — 19D° and remains constant
for some time ; it then risea to 200° at which point the oil piodaced by the free acid
distils over. The intermediate product, on rectification, boils atlBO°. It is a eolonrifia
aod very fluid oil, of apeciflc gravity 1-86, with a burning taste, an extremely irritating
odour, and exciting teare. It has the formola C*C1"0'. The action of slcohohc
potash on thie oil yields chloride of potassiom, and a -very solnble potasdum-silt
which crystallises in satiny acalea ; it haa the formula C*C1>K'0'. The same aait ii
produced by the action of potaah on the oil from tJie free add. A coiresponding
silver-aalt is very unstable, and is readily reduced to the metallic state ereo in the «^
The potassium-salt has the composition of that of a chlorinated succinic add. Tht
mother-liquor team which the clUoriDat«d oil has been depouted contains, besides
chloride of sodiom, the sodinm-solt of an add which has the compoaitioa of sucdme
add bat appears to be only isomeric with it.

10. When bromine is gradually added to solution of citrate of potassinni, a bnik
disengagement of carbonic add takes place; and if the addition of bromine be oonlinsed
ns long as gas ia given o£ and the excess of bromine csjef^lly removed by potash, an
oil is predpitated which is a mixture of two bodies. The most volatile ot theee ia
bromoform, CHBr". The other has rOTeivedftem Cahours the name bromoxaform.
It consists of lustrons silky needles, which by spontaneous evaporation GiystaUiae in
large colourless phites. Tiiey melt between 74° and 76° C, Init are gradually decom-
poMd by distillation. The formula of the body is CKBf*0' (pentochlorinated ^n-

CLARIFICATION— CLASSIFICATION. 1007

Ciret unites with oik, bat not with alcohol.

Boutron-Gharlard states, that in an unexoeptionably good civet, semi-fluid, unctuous
and yellow, he found free ammonia, stearin, olein, mucus, resin, volatile oil, yellow
colouring substance, and salts. No benzoic acid could be detected in it. (J. Fharm.
1824, p. 637.)

(nbASXVZOATZOW. Clariflcation is the process of freeing a liquid from hete-
rogeneous matter or feculencies ; the term is, however, seldom applied to the mere
mechanical process of straining, for which see Filtration. — Albumin, gelatin, acids,
certain salts, lime, blood, and alcohol, serve in many cases to clarify fluids, which
cannot be fireed from their impurities by simple percolation. Albumin or gelatin,
dissolved in a small portion of water, is commonly used for fining vinous liquors, as
it inviscates the feculent matter, and gradually subsides with it to the bottom. Al-
bumin in the form of white of egg or serum of olood is particularly used for fluids with
which it will combine when cold, as syrups ; as it is coagulated by the heat, and then
rises in a scum with the dregs. — Heat alone clarifies some fiuids, as the juices of
plants, in which, however, the albumin they contain is probably the agent. — ^A couple
of handfuls of marl, thrown into the press, will clarify cider, or water-cider.

Yeiy finely divided precipitates, wnich remain for a long time suspended in pure*
water, may often be made to settle down, by adding a soluble salt, such as sal-
ammoniac, to the water. The same addition greatly facilitates the filtering and wash-
ing of precipitates, which otherwise stop up the pores of the filter.

C&ASSZVICATKOW. The object of a dassiflcation of chraiical substances is
the arrangement of them in snch a way that the position in the system of each sub-
stance may express its own chemical nature and the relation in which it stands to
other substances. Hence it is easy to see that a system of dassiflcation, which
should be perfect, relatively to any given stage in the development of the science,
would be an epitome of the whole mass of chemical knowledge existing at the time.
Hitherto but slight advances haxe been made towards establishing a theory of the
causes or essential nature of chemical action; our so-called diemical theories arc,
for the most part, attempts to express the mutual relations of a greater or lesser num-
ber of chemical substances ; in reality, therefore, they are more or less comprehen-
sive schemes of dassiflcation. A general system of chemical dassiflcation ought to
embrace the fundamental prindples of all such partial systems, so as to show the
real nature and relative value of each : it ought, in fact» to be a general expression
of these theories in much the same sense that they are genoral expressions of
chemical facts. A discussion of the bases upon which a comprehensiye dassiflcation
is to be founded becomes therefore a discussion of chemical theories in general; and
in this artide we shall endeavour to set forth dearly those general results of chemical
research, by reference to which the true Talue of all diemical theories must, in the
present state of the science, be tested, and which must for the present, be taken as the
foundation for any attempt at chemical classification, rather than to construct a detailed
scheme of classification in which each individual substance should find its place.

A collection of complex objects can always be classified in several difierent ways,
according as this or that quality is regarded as the most important In the case of
chemical substances, two causes are always at work to bring about changes of the
point of view from which they are regarded with reference to their classification. In
the first place, the number of objects to be dassified is continually increasing through
the discovery of new substances ; and, in the second place, the finding out of new
qualities in the bodies already known, tends continually to modify their apparent
rdations to each other. Hence it is not surprising that» instead of otfr being able to
trace, in the history of chemistry, the gradual extension of one ftmdamental scheme of
classification, we should find that the prindples upon wliich it has been attempted to
dassiff eheinical substances have been gntdually, but frt>m time to time almost
completely changed as the sdence has advanced. It is not necessary to consider here
what these changes have been ; we have only referred to their occurrence, in order
to draw attention to the &ct, that the most perfect dassiflcation which it is possible
even now to cive, can of necessity be nothing more than a representation of the results
of chemical kbour, as they appear viewed from the point which the sdence has now
reached, and that it must hereafter be absorbed in some more general system, if it be
not entirdy set aside.

All chemical substances bdong to one of two dasses : namely, elements or simple
bodies, and compound bodies. The chemical deflnition of an element is — a
body which cannot be decomposed or shown to contain matter of more than one
kind ; compound bodies, on the other hand, are such as are made up of, or can be de-
oomposed into, two or more distinct kinds of matter. For instance, water can be

988 CINNAMIC ACID.

namie add (Mitscherlich, Kopp), or by heatinff styrone with nitric add, to vldek
urea is added to preyent formation of nitrous add ^Wolf f). To prepare it^ eonces-
trated nitric add is freed from nitrous acid by boiling, and after cooling, aboot one-
eighth of dnnamic add is added. The dnnamic add dissolves in a few minutes witiunt
^en^agement of gas, the liquid becomes heated to 40° C, and a mass of aysUk a
deposit^ In order to obtain larger quantities, dnnamic acid is triturated vith mtn
acid and cooled, so that the temperature may not rise above 50^ ; the mass is vuiied
with cold water, till all nitric add is removed, then dissolved in boiling alcohol ud
filtered; and ike resulting crystals^ are waedied with cold alcohol (MitscherHeh).
Kopp dissolves 1 pt of powd^^ dnnamic add in 3 pts. of monohydrated nitric add
freed from nitrous acid by passing a dry stream of air through it^ the mixture then so-
lidifying almost immediately, in consequence of the crystallisation at the nitrodxmanie
acid ; washes the magma with waiter; then dries, and sets it aside for twenty-four horns
with 4 pts. of cold alcohol, whidi removes any benzoic add that may be present

The add forms very small white crystals, with a Saint yellowish tint It melts at
about 270^C., and solidifies to amass cicTystuSB on cooling; boils a little above 270°, vith
deoompontion. It is nearly insoluble in cold water, and dissolves but sparingly in boil-
ing water ; 1 pt of it dissolves in 327 pts. of absolnte alcohol at 2(P C BoiEng bydzo-
chloric add dissolves it without decompodtion (MitscherHeh.) With sti^k^ of
ammonium it forms carbostyriL When it is dissolved in alcoholic sulphide oif ajDmo-
nium, sulphur separates on gently warming the liquid, while a yeUow resm and an alkt-
loid remam dissolved. Nitrocinnamic aad may be boiled with excess of alkali without
decompodtion.

Nitrocinnamic acid is but a feeble add ; nevertheless it forms neutral saltan ad
decomposes alkaline carbonates. The nitrocinnamates of the alkali-metals are ray
soluble, the rest are insoluble or sparingly soluble; they deflagrate when qaidly
heated, especially the potassium- and sodium-salts.

Nitrocinnamate of Ammonium gives off its ammonia when evaporated to diyness; its
solution predpitates the salts of calcium, strontium, and magnesium when they ire
concentrated, but not when they are dilute,

Nitrocinnamate of Barium, 2C»H»(NO«)BaO« + 3aq., crvstallises from a bofliag
solution on cooling, in stellate groups of yellowish needles. The stronUvm-uU,
2C*H*(NO')SrO*-*-6aq., maybe obtained in small yellowish crystals grouped in no-
dules; it is moderately soluble in cold water. The calcium-sali, 2CH^NO')CaO'r3aii,
forms small yellowish white a^Iomerated grains having a crystalline aspect Tbe
moffnesiwrnraalt, C»H*(NO*)Mg^+ 3aq., crystallises in ydlowish white nodules, whid
dissolve with tolerable facility in water, especially if warm.

Nitrocinnamate of Copper. — Bluish-white precipitate, which becomes darker vhoi
air-dried. When mixed with sand and distilled, it yields benzoic add, nitzDeinnsmes*
having the odour of oil of cinnamon, and a small quantity of nitrobenzene.

Mercuric Nitrocinnamate, C"H«(NO»)HgO» is thrown down from boiling solutioM of
mercuric chloride and an alkaline nitrocinnamate, as a brownish anhydrous predpit^
The mother-liquors deposit on cooling a crystalline mass of very light bulky arbo-
rescent tufts, consisting of the double salt, 2(HgC1.2C"H«(NO«)^0«) + 3aq.

Nitrocinnamate of Potassium, C»H«(NO«)KO«.— Very soluble ; crystallises in msmel-
lated groups by spontaneous evaporation. From solution in boiling alkaline ley, »
crystallises in prismatic needles. The sodium-salt resembles the potassium-salt

NitroeinnamaU of 3Uffer. C»H«(NO*)AgO».— Yellowish white infloluble precipitat<^
which, when cautiously heated, decomposes with projection of the silver.

NiTROcnwAMic 'Etvbbs.— The ethyl-compound, C'>H«»NO* « C»H»(NO"XC^)f!*»^
formed by heating nitrocinnamic acid with alcohol and sulphuric add (HitscherlicDi
J. pr. Chem. zxii. 1 94), or by the action of strong nitric add on dnnamate of ^
(E. Kopp, Compt rend. xxiv. 616). It crystallises in prisms, which melt at 136 uj
boils with decomposition at 300°. Potash at the boiling heat converts it into alcoW
and nitrocinnamate of potassium.

Nitrocinnamate of Methyl. C"H»NO* - (?H«(NO«)(CH»)0*. (E. Kopp, Compt
rend. liii. 636.)— Obtained by heating nitrocinnamic add with methylic aloohd, mij^
with a small quantity of sulphuric add or saturated with hydrochloric add gas. ^^
mixture thickens at first, then liquefies again, and finally a brown liquid is obtained,
from which the ether separates as a crystalline mass, which may be yuaHsd ^7 P*^
sure and recrystallisation from alcohol It forma white, delicate^ rather ^^^f^S
needles, sparingly soluble in cold alcohol and ether, and having but little odaot', nei
at 161° C. to a colourless liquid, which solidifies in a ciystalline mass on ^^^'y^
about 200° C. it begins to sublime in iridescent crystalline plates, and at 200*^ jt b^
It dissolves in alcoholic sulphydrate of ammonium, fi>rming a red li^dd, which ****^
wards turns brown, and when heated yields an abundant crystallisation of soipAB^

CLASSIFICATION. 1009

2. Triatonde Elements. — Nitiogen (N « 14), phosphornB (P as 31), araenic (Am
-i 75\ antunoDv (Sb » 121)^ bismuth (Bi » 208) ; boron (B - 11) ; gold (Au » 197) ;
probaoly molybdenmn (Mo « 48), vanadium (Yd ■■ 68'5), tungsten (W — 92); and
perhape others.

These elements do not form many combinations amons themselyeB not containing
any element belonging to another claiss. They combine with the monatomic elements
in the proportion of 1 at to S, to form such bodies as KH", PH*, AbR\ 8bA^, BiCl',
BCl', AuCl*, &C. ; 1 at. of some of them can also combine with 6 monatomic atoms,
many bodies of the following form being known : NH^Cl, PH^I, PQ*, &c ; but none of
these compounds appear to oe capable of Tolatilising without decomposing; so as to re-
generate a compound of the class first mentioned, as £own in the following examples : —

NH<a - NH» + HCl
POT » PCI* + CICL

With the diatomic elements and with the diatomic and monatomic elements together,
they combine in very various proportions, but always so that the sum of the triatomic
atoms, or of the triatomic and monatomic atoms together, when the latter are present,
contained in a molecule of the products formed, is an even number.

3. TetraiaTMcElemenes.'-Caxhon (C « 12), silicon (Si - 285), titanium (Ti - 485),
tin (Sn » 118), tantalum (Ta « 138); probably lead (Pb » 207), and perhaps other
elements.

These elements can combine with the monatomic elements in the proportion of 1 at.
to 2 (e.g. SiCl^ SnCl'), and with the diatomic elements in the proportion of 1 at. to 1
(e.g. GO, SiO, SnO); but the compounds so produced readily combine with 2 mon-
atomic atoms, orwith 1 diatomic atom, to form such bodies as the following : Sid*, SnCl*,
COCl', CO*, SiO', &c, which appear to represent the normal compound of the tetra-
tomic elements. They also form verv man^ compounds with the triatomic elements,
or with these and the monatomic or diatomic elements together. The following are
examples of the simplest combinations so produced :

C«N», CNH, CNHO.

4. Hexatomie EZemm^.— -The following elements are perhaps hexatomic: iron
(Fe M 112), aluminium (Al « 64), and other similar bodies.

Mlret to the statement of certain feets whose bearing on the point will be understood if the reader has
studied the article Atomic WsioaTt.

». Magnesium, Ztme^ Cadmium^ Jlfcre«yy— Of these foor elements It may be said, that the eTldence in
favour of doubling the atomic weights of sine and mercury is concluslTe, while magnesium and cadmium
are so obviooily members of the same natural family, that it Is not possible to double the atomic weights
of the former two metals without doubling theirs also. The most important reason for doubling the
atomic weights of sine and mercury are the following i — When these metals act upon the iodides of the
aloohol-ramdes, 60 pts. sine or 900 pts. mercury combine directly with the quantities represented by the
formulsB CH'I, C*H^I, CSH'M. (PH^I. fai each case formlog a single product, such as Zn"C*H»I,
Hg"CSH>I,He*"C*H»I, ftc, as though 65 pts sine and SOO pU. mercury, represented Indivisible quantities,
or atoms, of those metals, whereas if these weights represented two atoms, we should expect that the
action of 66 pts. sine or of 900 pts. mercury on C*H^I would give rise to two distinct products, ethyllde
and iodide of sine or of mercury. The combination which actually takes place is analogous to the com-
bination of (the diatomic element) oxygen with cyanide of potassium :

KQy -C O a KCyO ;

if sfaie and mercury were monatomic, their action on the hydrlodic ethers would probably be analogous
to that of (the monatomic element) chlorine on cyaxiide of potassium :

KCy + CIS a KCl -I- CyCl.

Again, the reactions represented by the following equations (and the similar reactions which take place
with mercury-methyl) all teud to show that a molecule of mercury-ethyl (or mercury-methyl) contains
9 at. ethyl (or methyl) :

Hg(C>Il»)(CSHB) + BrBr » Hg(CSIP}Br + C>H».Br (Buckton).

l]g((?H«)(C^H>) + CIB - Hg(C>HS)a + C*H>.H (Buckton).

Hg(CiH'}(CSH») -I- HgClCl - Hg(C>H»)a -f HgCl(C>H») (Bnekton),

and it is difficult to understand what can cause the two atoms of alcohol-radlde to remain combined, if it
be not that the quantity of mercury with which they are united is one indlrlsible atom.

To these chemical arguments may be added that drawn from the determinations which have been made
of the Tapour-densitics of sine and mercury compounds. All the determinations hitherto made agree
with the supposition that the atomic weights of these metals are 65 and 900 respectively, and not 89*6 and
100, as generally admitted ; the specific heats of these metals ooint also to the same eonduslon.

We may add, 6naliy, that the readiness with which all the four metals under consideratioQ fbrm basie
salts is a fbrther indication of their diatomic character.

B. Caieimm, StronihoH, Awfims.— The decomposition of the hydrates of these metals by heat alone,
taken hi connection with their general close resemblance to the alkalis, mav be regarded as evidence
of their being hydrates of diatomic radicles bearing the same relation to the hydrates of potassium, so-
dium, ftc, that the bibasic adds (most of which are similarly decomposed by heat) bear to the monobasic
acids. Moreover, the nonexistence of acid carbonates, sulphates, oxalates, Ac., of any of them seems
to show that the quantities of metal (twice the Quantities usually admitted as representinff their atomic
weights) contained in their neutral salts with blbaslc adds are indivisible. Notwithstanding, however.
tb««e and some other Indications of a diatomic character, the atomidtj of caldnm, strontium, ana
barium vast be consMwed as still more or less open to question.

Vol. I. 8 T

Old umplM o(t«D dpporitcTTitaliofcmiiaiiiie add. The density of the inb mica tn
1-026 to 1'0£; their boiling point from 220° to 22fi'> C.

Eetini from Cinnamor^M. — Old Bomplea of the oil are more or leas eolooRd ud
chuged with resinous matten. which remain, aAer the oil has been distilled nith alt
mter, tbe residne treated with cold wster, to eitfoct the suit, and ofterwuds lill
boiUng water, to extract einnsmic acid. According to Mulder (Ann. CLlliim.
zuiT. 119), there ars two resins formed in the oil b^ atmoapberic: oxidatim ; oh, i,
■olable in cold alcohol, melting at 60° C, and coataioing; 78'33 per csnL aHmi, S-tf
hydrogen, sjid 1518 oxygen ; the other, &, ■paringlvsoiabla only in hot alcolial, mk'
ing at 14S°, and cotttaining B3-1S per cent. C, S-03 H, And 10-49 O.

Uulder likewise de8crib« MTeral other reains, some solnble, others insolaUe b il-
eohol, produced by treating oil of cinnamon with SDiphoric acid, hydrochloric acid, ud
ammonia : they have all nearly the same compooition aa the ^-reeio, prodocsd liy il-
mospharie oxiiktion. (Gm. ziii 264.)

OnnrAlKtnr-BTOKS. A lariety of ganiet (;. «.)

OIW&STTX. VB?0. — Tbe moaatomic radicle of cinnamic acid and its don-
tivea. The following is a list of ita compoonds, and of those of the deriTed ndido,
cbloiDcinnamyl, &c.

CUoride of Ciunamyl CrffO-a

Cyanids of Cinnamyl CH'O.Qf

HTdride of Cinnamyl ; CmnoTme Aldtlu/dt .... CMI'O.B

^drideofTetrachlorocinnamyl: CJUorucinttaM . . CflVi'Oil

I^pcHHO:
Hydrate of Cinnamyl; Cinnamie Acid . . . CH'O.H.O

Hydrate of Bromocmnamyl : BnrniocHniami! Acid . C»H'BrO.H.O
Hydrate of Chlorocinnsmyl : ChloTocinnamie Acid . CHflO-aO
Hydrate of Nitrocinnamyl: mtrocinnamio Acid . C»H"(NO')"0-H.O

Oiide of Cinnamyl : Cinnamie Anhydride .... {(7H'0)V
Oxide of Cinnamyl and Acetyl ; Aceto-einnamio Anhv-

dride cwo.cmv.o

Oxide of Cinnamyl and Bennd : Bento^nnanac An^-

dride CH'O.CHS).0

Oxide of Nitrocinnamyl : t/itrocinnavaa Anhydride . [C?H*(NO^]*0

ninnHmide N.H'.OrH^

N.H.C'H'.CH'O
N.H.C'H*(NO')O.CffO

The compounds of danam^l are intimately related to those of beotoyL CBK), ai
are easily converted by oxidising reagents into hydride of benzoyl and benioie toi-
Cinnamie add heated with excess of borate of potassium, ia re«dTed, witli enihtioa
of hydrogen, into acetic and benioie acids (p. 981).

OIVXASCTX* OB&Oftma OT. CH'O.CL (OahoDrs, Ann. Cb.Fliy&P1
xiiii. 341.— B^champ, Compt. rend. xliL 221,)— This compound is [»odiiccd Irr ''*
action of trichloride or pentachloride of pboephoms on cionamie acid Vhei tb>
pentschloride is used, the product is' distillod, Che portions which pass over b«t«*
260'" and 266° C. being collected apart and rectified (Cahonrs). With the !«*»■
ride, the mixtore must be heated to between 60° and 12u° C, aa long as hydiodilanB
acid continues to escape. It then melts and forma two layata, the upper of ma,
consisting of chloride of cinnamyl, ia decanted and distilled, (Bj champ.)

Chloride of cinnamyl ia a heary oil, of specific gevriW 1-207, boiling at 2fl2° C. U
a moist atmosphere it decomposes quickly, yielding hyteichlorio aeid and fine crjst"
of cinnamie acid. In contact with alcohol, it bwomes strongly heated, and if ^f'
be then poured upon the mixture, cinnamate of ethyl sepaiataa as a heavy ofl. ^i''
ammonia and phenylamine, it yields ciunamide and pnenjl cinaamide rcspccbTcif-
Heat«d with cinnamate of sodiom, it yields cinnamie anhydride.

omABrrXi. trr±xmm or. CHifO ^ (?H'O.Cy. (Cibozri.loi^"!-)

— Produced by distilling chloride of dnnsmyl with cyanide of potassium "^^'J'm
of mercury. A liqnid then passes orer, which rapitQy turns brown when eip"" "
the air, yielding hydrocyanic and cinnamie acids. It still conl^ns chlorine '"'' ''''''
aisCs for the most part i^ cyanide of cinnamyL

annrAMir&, KTSKXBH or. CHK) - CH'O.E. CVnnamo Jliif^
(DnmasandPiligot, Ann. Ch.Phys.lTu. 306.— Mulder, Ann. Ct. PhanD.m"'

CINNAMYL : HYDRIDE. . 991

147.— Bert a gn in i, «Wrf. bmcv. 272.— Gm. xiii. 258.— Gerh. iii. 373.)— This com-
pound forms uie eesential part of oil of cinnamon or oil of cassia, and may be sepa-
rated there&om by the action either of nitric acid or of the acid sulphites of the
alkali-metals.

a. When commercial oil of cinnamon is shaken ap with strong nitric acid, lax^
ci^stals are formed, after two or three hours, consisting of a compound of nitric acid
with cinnamic aldehyde, which, when collected on a filter, so as to allow the stUl liquid
portion to drain off, and then decomposed by water, yields pure cinnamic aldehyde.
(Dumas and P^ligot)

6. Oil of cinnamon is agitated with three or four times its Tolume of a solution of
acid sulphite of potassium of 28^ — 30^ Bm ; and the ciystalline mass, which forms in a
few minutes, is separated from the mother-liqaor, left to diy on a filter, then pulverised,
-washed with cola alcohol, again dried, and dissolved at a gentle heat in dilate sul-
phuric acid. A large quantity of sulphurous acid is then given off, and the cinnamic
aldehyde rises to the surface as an oil, which may be purified by washing and drying.

Cinnamic aldehyde is a colourless oil rather heavier than water. It may be distilled
without decomposition, either in vacuo, or with water which has been freed from air by
boiling. When exposed to the air^ it quickly becomes yellow and resinous, and ac-
quires an acid reaction. It rapidly absorbs oxygen gas, especially if moist, and is
thereby converted into cinnamic acid. Heated with nitric acidf it forms benzoic acid
and hydride of benzovl. Chramic acid converts it into benzoic and acetic acids
(Persoz). Boiled with solution of hypochlorite of calcium, it yields benzoate of
calcium. Strong sulphuric acid converts it into a resinous mass.

Cinnamic aldehyde gradually heated in a stream of chlorine^ forms at first a liquid
compound, which solidifids when treated with a strong solution of potash. When dis-
tilled four or five times in a stream of chlorine, it is converted into tetrachlorocinnamyl.
With pentachloride of phosphorus^ it yields hjrdrochloric acid and chloride of cinnamyL
Fused with hydrate of potassium^ it forms cinnamate of potassium, with evolution of
hydrogen :

C»H«0 + KHO =- C»H'KO« + H«.

Jmmonia-yas converts it into cinnhydramide :

3C»H"0 + 2NH» - C»H«N» + 3BP0.

Compounds of Cinnamic Aldehyde.

a. With hydrochloric Acid, — Oil of cinnamon absorbs a large quantity of hydro-
chloric acid gas, acquiring a green colour and becoming thicker. 100 pts. of the oil
take up 26'9 pts. of hvdrochloric acid.

b. With Iwiine and Iodide of Potassium. — ^When cinnamon- water is placed in con-
tact with iodine and iodide of potassium and cooled to 0^ C, a crystaUisable compound,
CH'O.P.KI, is formed. It crystallises from alcohol and ether, but water decomposes
it, setting free the cinnamic aldehyde. An excess of iodide of potassium prevents the
decomposition. (Apjohn, Ann. Ch. Fharm. xxviii. 314.)

c With Nitric Acid, C'H'O.HNO*. — ^Produced when strong nitric acid is left in
contact with cinnamic aldehyde. It forms oblique, rhomboidal prisms, often two or
three inches long. After being drained, they may be preserved for some hours, but
the least rise of temperature or atmospheric humidity quickly decomposes them. When
treated with water, they vield pure cumamic aldehyde.

Nitrate of cinnamic aiaehyde kept in an imperfectly closed vessel, yields after a few
days a red liquid, which has the characteristic odour of bitter-almona oil, is converted
by ammonia-ffas into nitrate of ammonium and a red resin ; and is dissolved by strong
sulphuric add, the solution yielding with water a precipitate of cinnamic acid.

a. With Acid Sulphites of AlkaH-metals, — Cinnamic sldehyde dissolves easilv in
aqueous add sulphite of ammonium, forming an oily liquid, which afterwards sob'difiee
to a crystalline pulp. Oil of cassia shaken up with a strong solution of acid sulphite of
ammonium soon solidifies to a yellow crystalline mass, which may be purified from the
hydrocarbon and other substances which the oil contains, in addition to cinnamic al-
dehyde, by washing with alcohol of 80 or 90 per cent. (Gossmann). The compound
is very unstable, quickly turning brown, even when kept in dosed vessels.

The potassium-salt is obtained by agitating oil of Ceylon or Chinese dnnamon with
three or four times its volume of a solution of acid sulphite of potassium of 28^ to
30^ Bm.; after washing with alcohol and recrystallisation from boiling alcohol, it
forms beautiful silvery plates nearly inodorous and permanent in the air. It is soluble
in cold water, but the solution^ is decomposed by heat, giving off sulphurous acid and
yielding colourless drops of cinnamic sldehyde. Heated in a test-tube, it gives off
water, sulphurous acid, and dnnamic aldehyde, which, by contact with the air, is con-
verted into dnnamic add. Bromine and iodine dissolve in the aqueous solution with-

992 . CmNYL— CITRACONIC ACID.

out coloxiring it, but converting the snlplmrons acid into sulphnric acid, and setting fres
the cinnamic aldehyde. Bromine in excess produces s solid, slightlj aromatic nib-
stance fusible in hot water.

Sodiumsalt — Oil of cinnamon mixed with solation of add sulphite of rodinm of
87° Bm. forms a crystalline fibrous substance, which, if left to itself soon becomes oon-
pletely liquid ; at the same time there is formed an oil which is not solidified, dtfaa by
acid sulphites of alkali-metal or by nitric acid, the sulphite of cinnamyl-sodimn apps*
rently remaining dissolved. The liquid, if left to evaporate, yields crystals of snlpaate
of sodium, togeuier with opaque ci^stalline nodules, which dissolve in boiling alooho],
forming a solution which on cooling deposits long thin needles arranged in spul
groups. (Bertagnini.)

Htdridb of Tetbachlobocinnaxtl. Chloroeinnose, CHK!1H).H. (Bnmas
and P^ligot, Ann. Ch. Phys Ivii. 316.) — By repeatedly distilling hydrate of cinoamjl
in chlorine gas, this compound is obtained in long white Tery volatile needles. It mdti
at a gentle heat and sublimes without decomposition. It ia soluble in alcohol It k
not decomposed by strong sulphuric acid, even at the boiling heat^ and may be Tob-
tilised without alteration in a current of diy ammonia.

The formation of this substance is preceded by that of several liquid compound!, ooe
of which, perhaps hydride of monochlorocinnamylt solidifies in contact with potash-Iej.

CJJiJilJi. CH*. — The radicle of the compound usually called cinnamie aknboi
or ttyrone. Cinnyl bears to cinnamyl, C*H^O, the radicle of cinnamic acid, the same
rektion that ethyl, C*H*, bears to acetyl, C«H»0.

cmr&ZC AXiCOBOlb. CH'«0 « C*H*.H.O. HydraU of Cifmj^ Cumam
Alcohol, Styrone, StyracotiBy Styrax-Alcoholf Styrylie Alcohol, Peruvin, (B. Simon,
Ann. Ch. Phann. xxxi. 274.— Toel, ibid, Ixx. 3.— Strecker, ibid. Ixx. 10.— J. WoJi^
fWrf.lxxxv. 299.— E. Kopp, Compt. chim. 1860, p. 113.— Scharling, Ann. Ch-Phmn.
cxv. 90, 183.— Qm. xiii. 256.— Gerh. iii. 402.)— This compound is obtained by e»-
tiously distilling styracin with a strong solution of caustic potash or soda. A miltf
liquid then passes over, from which, when saturated with common salt, a creamy 6al>-
stance separates, gradually coUectLog on the surface in an oily lajer and Bolidifpg
(Toel). Wolff dissolves styracin in boiling alcoholic potash; mixes water with the
liquid ; filters from cinnamate of potassium ; and separates the precipitated dmiMue
alcohol from undecomposed styracin by distillation.

Ginnylic alcohol forms beautiful soft silky needles, having a sweet taste and a
agreeable odour of hyacinths. It melts at 33° C, and volatilises without alteration at
a higher temperature. It is moderately soluble in water, very soluble in alcohol, in ether,
in styrol, and in oils, both fixed and volatile. When the aqueous solution satnrated at
the boiling heat is left to cool, it becomes milky, and does not clarify for several bcna,
when it becomes filled with needle-shaped crystals.

OZPOXAMTOa A white marble with shadings or zones of green talc^ fbond in Ita^>

OlBBAMmOJOnL Syn. with PRLOsnnt (g. v.)

OXTRACOVAaOBBB and CITSACOWAVZKZBaS. See AxmBS OF &
TBACONic Acm (p. 993).

CZTSAOOmc ACZB. Pyroeitric Add. C*H«0*. (Lassaigne p822],ABiL
Ch.Phys.xxi 100.— Dumas, ibid. cxi. 21.— Robiquet, ibid. Ixv. TS.-^^iehig, J^
Ch. Pharm. xxvi. 119, 162.— Crasso, ibid, xxxiv. 68— Engelhardt^ ibid. ia. 24^
—Gottlieb, ibid. Ixxvii. 265.— Baup, Ann. Ch.Phy8.[3]xxxiii. 192.— Gbl x- «[.-
Gerh. ii 120.)— This add, orratherits anhydride, is produced by the dry distaUabon
of citric acid, constituting in fiict the chief portion of the distillate (p. 996). ^**2J'
dride rapidly attracts moisture, and when exposed to the air, is converted into aaj"**'
line mass of citraconic acid, which is freed from excess of water by pressure ^^'^'J
blotting-paper and exposure to a temperature of 50^ C. Citraoonic add is also ooo or
the products of the diy distillation of lactic add.

Citraconic add is inodorous, and has a sour and slightly bitter taste. It aystalMejui
fouivsided prisms, dissolves in 8 pts. of water at lO** C, and is readily soluble la «»•
hoi and in ether. It melts at 80° C. ; smaU quantities of it kept for some w
at 100° are converted into itaconic add. By diy distillation it is resolved into ot»-
conic anhydride and water. ^

When dtraconic add is heated with strong nitric acid, a violent reaction is "^^
accompanied by disengagement of gas, and an oily body is produced, which on ^^"^
solidifies to a crystalline mass, oonsistinff of two crystalline nitro-componnds, ff ^ '
and dyslyte, which dissolve in alcohol to an unequal extent; their ^"*P°^^"
not known. By dilute nitric acid-, citraconic acid is converted into mesaeonie .

When bromine is gradually added to a strong solution of citraoonate of potassiuro,
bonic acid is disengaged and a heavy ydlewish oil separates, consisting ^^*°?^ijj(||
a neutral substance. The former is removed by treatment with dilute potash, wu

CITRACONIC ACID. 993

leiiTes the latter unaltered. When a weak acid is added to the alkaline solution, theie is
separated, sometimes a heavy oil and sometimes fine needles. These two bodies axe iden-
tical in composition, and consist of an acid, C^H'Br'O*, which has been named by Ca*
. hours, its discoTerer, bromotriconic acid. It has the composition of dibrominated bntyric
acid (p. 693) ; bnt Cahonrs did not obtain it }yj the action of bromine on butyric add
or but^nrate ofpotassium. The liquid acid is slightly amber-coloured, and has a pecu-
liar odour. When distilled, it gives off hydrobromic acid and leaves a carbonaceous
residue. The liquid acid, after standing for some time, occasionally solidifies to a mass
of crvstals. When it is heated with concentrated potash, a peculiar odour is disen-
gaged, and the addition of an acid no longer precipitates an oil The acid forms a
en»ly precipitate with silver-solution, and its ammonium-salt aystalUses.

The neuto&l oil formed in the preparation of the acid has the composition CH'Br'O,
and may either be tribromopropionic aldehyde or iribromnated acetone,
' By the action of bromine on citraconate of potassium, or on this salt in the presence

' of excess of hydrate of potassium, an oil is also separated and carbonic add disengaged.

^ When a weak solution of potash is added, the greater part dissolves, and a small quantity

■ of tribromopropionic aldehyde remains ; on adding dilute nitric add to the alkaline solu-

tion, large white crystalline flakes are deposited, consisting of an add which czystaUises
^ from alcohol and ether in long prisms. It has the composition of tribromopropionic

' acid, CH^rK)', but Cahours names itbromitonioacid.

' GiTBA.ooiri.TB8. — Gitracouic add is a dibasic acid, and forms two series of salts,

the neutral ealte, (yB*WO\ and the aoidsalte, C*H''MO'; they aie isomeric with the

itaconates, mesaeonates, and lipates. The acid salts mostly ciystallise well.

The acid barium-ealt^ OM*BaO\ crystallises in large groups of fine silkv needles.
The neutral eilver-ealt^ C*H*Ag*0*, cr^tallises both anhydrous and with an

atom of water. In an aqueous solution of atraoonic add, nitrate of silver produces,
I on addition of ammonia, a verv bulky precipitate which dissolves in boiling water.

; On cooling, the salt is deposited in long needles. If the mother-liquor from this be

slowly evaporated, hexagonal ciystals are formed which have an adamantine lustre, and
\ . consist of the hydrated salt» C»H*A^O* + H*0.

c ThQacid eilver-ealt, C*H*AgO^ is obtained by dissolving the neutral salt in an

I add solution of dtraconic add. On evaporation, large groups of crystals are obtained.

; Oitraconate of Ethylt OT Citraoonic Ether, G*H"0\ is obtained by repeatedly

cohobating anuxtare of alcohol, dtraconic add, and hydrochloric acid, and wasning the

distillate with water.
I It is a colourless, bitter, somewhat aromatic liquid, of density 1*040 at 18^*6 C. It

boils at 226^0. with partial decomposition. It is insoluble in water, but readily soluble
[ in alcohol and in ether. In contact with water, it gradually acidifies and alcohol is

formed. By potash it is decomposed into dtraoonate of potasdum and tJoohoL £. A.

crrmjLOOimza acid, ambbss ov :

CiTBAOOXAXiDB, C^BTOPK)' - N».H*.(C*H*0«)'', is obtained as a yellow viscid
mass, which becomes brittle and vitreous on cooling, when dtraconic anhydride is
heated in a stream of dry ammoniacal gas. It dissolves in water, and the solution on
cooling yields dtraoonate of ammonium. It is derived from neutral dtraconate of am-
monium by the loss of 2 at. of water :

C*B*(SB*yO* - 2H»0 - C»H"NK)«

CiTBAOONiMiDB. C»H»NO* - N.H.(C»HW)''.— Citraconic add is mixed with
excels of ammonia and evaporated to diyness, and the residue heated to 180^ C. An
amorphous oily yellow mass is le^ which is dtraconimide. It does not dissolve in cold
water, and but slightly so in alcohol ; it is highly hygroscopic. It is derived from
add citraconate of ammonium by the loss of 2 at. of water:

0»H»(NH*)0* - 2H»0 - C*H«NO«.

Phenylcitraeonimide or CfitraconanU, C"H^O» - N.C^».(C»H*Oy.-.When
anhydrous dtraconic acid is mixed with phenylamine, a brisk action ensues, and the
mixture, if kept for some time in the water^bath, is totally converted into the above
compound. It crystallises in colourless needles, which melt at 96^ C, and sublime at
a little above 100°. It is readily soluble in alcohol and in ether.

It is derived from acid dtraconate of phenylamine by the loss of 2 at of water :

C»H»(C«H*N)0« - 2HK) - C"H*NO«.

lodophenylciiraconimidey G"H'INO', is obtained by substituting iodophenylamine in
thfi &bov6 reaction

Vimtrophtnyldiraconimide, G"H'(NO*)«NO«, is obtained by the action of a mixture
of nitric and sulphuric add on phenyldtruconimide.

Vol. I. 3 8

It will be nsdenitood that Qie foregoing lemArlu toitcliiiig the comlnmi^ "f*^
of Tuioos ktomic groupings, and the «aj in which it is afiected by tike addituu k
■lomB of Tariaus kmda, have rofarence 01^7 to the li^kett nttmber at monitomie itmu
that ia ever fbond in combination with a given nambei of polyatomic atomi; uithil
it is by no means intended to imply that all compoonda contain, or even ihcv D]
great tendency to combine with, the whole nnmbec of monatomic atoms vUcJi Uk
nlea above given indicate as the itimiiniiin in each case. Several compiiniiiig M
containing the maztmnm of monatomic atoms have alreadj been incidentallj itfand
to ; bnt it is neeetsaiy that the eonatitation of anch componnda ahould be nswibl
tnore speciallj discnssed in relation tA the theoi; of the deflmt« combining lajutj
of lh« eWentarj ktoma.

Aceording to thu theo^, there are four different waya in which it it potditt fa
two tetxatomio atoms, for instance, two atoms of carbon, to oombine. Two radi lioti
may matosUy saturate, cither the whole, three fborths, one half^ or one fourtli of aA
oth^B oMnbming capacity, as expressed by the following diafpoma : —

rm I I I I I I I I MM

mpivteLj utaintnL

e first disgiam pie _ ^ _

and fonrtli, the manner in which the two eBrboQ-«tomB are combined in tesljhs^
(?H', ethylene, (?H', and hydride of etbjl, CfH', rmpeotiTclj. In the la* of tbm
bodiea, one unit only of the oorabining capaeity of each carbon-atom ia ntanttd h
the other, laoving three units of affinity belonging to each free for combinalioB »i!a
hydrogen ; and it is plain that two atoms of carbon can only combine with 1 larpi
number of hydrogen, or other monatomic atoms, than are contained in this coafmi.
when they aie entirely nneombined with each other. In etljlene and acelyloi^ "
the other hand, the two atoms of carbon are so combined that, if we may » ^«t
they can combine with an additional number of monatomic atoms by looseuisg, ■illi'
ont Botipely giving np, their hold iqiOB eacli otbec. And in all componndf is "iid
the DFoporlion of monatomic to polyatomic atoma is below the maximum indicated hj
the formula gives higher up, we must, unless we suppose the atomicity of the elfiatiti
to be variable (in which case the word atomicity ceases to have any speciil meuiuig^
suppose that a greater or lesser number of the piuyatomic atoms are combined in s km-
lar way. But, m the great m^'ori^ of such cases, the composition alone of a compMal
does not enable us to decide as to how many of ita ptdyatomic atoms are in tliis Hii
of more intimate nnion with each other. For example, oUylene, CH*, homalogcnuiuli
acetylene, might, so far as its mers composition is concerned, be constitnted a&a

ever, would be somevhat different in the two cases. It would not be possible to lot-
bine a compound conotituted in the first manner with two atoms of hydiogro, wilboot
transforming it into propylene, CH', or an isomeric body ; bot it wonld donbtlea bj
possible, under appropriate conditions, to cause a body constituted in the seam
manner to split up, by tbe addition of two atoms of hydrogen, into monh-gu, CE'

<-[ I j ]. ■.d.nit,U.^C1P..,j } j [ j

In tJiepreceding port of this article, we have triad to show that thoM of the ehnenli
which have been suffieiratly atudied may be divided into distinct classr^ aectndjigl"
the manner in which they enter into combinatioii, and further, that each element f*
■esses a certain deSnite atomic combining lapv^ty, which rcgolatts the fbimiCiaii *
its most complex as well as of its Bimplest compounds. By the ^iplieation rf tl^
principle of the definite atomicity of the elementa, it would be easy to constnict tsUit
showing all the possible combinations of each element ; ail compounds whose comtil^-
tion was snfflctently nnderatood, misht then be classified by inserting them in ^
places in these tables. Bat since Uie place of any compoiuid would be det«iinii>»
not only by its composition, but also by the mode ck' order of combination of its stoi^
a point concerning which we have, in most Cases, no definite knowledge, 10^ *
^tem of classification would not be widely sp^caUe in tlie present state of "^
mistiT. Ouracquuntonce with the great minority of the more complex compounds wn-
Ststs in the knowledge of transformatiOQa, by which only a small nnmbra' of their iSooi
nre afiltcted. It has, therefore, been found convenient, for the numosn of claMifiesdoa

CLASSIFICATION. 1016

to regard such compoondfl as consisting of two parts, namely, the atom &r atoms which
take part in their Imown transformations, and a residue, or nndens, or radicle, which
is nnaffected by these transformations, and appears as a constant constituent in all
the prodacts to which they give rise. By aid of this convention, the classification
founded upon the atomicity^ of their elements, which, as we have seen, is applicable to
the more simple compounds, may be extended so as to comprehend all tolerably well
known substances. The radicles, whose existence this view supposes, may be of any
degree of complexity ; their nature and their relation to the compounds in which thev are
contained will be most easily understood by considering a few of the sim^est of them.
Hydrochloric acid, HCl, water, H'O, ammonia, H'N, and marsh-gas, M*C, have al-
ready been shown to be compounds, each of which may be taken as the representative
of a whole class of bodies. If we imagine 1 atom of hydrogen to be removed from each
of these substances, it is plain that the residues CI, HO, H^, H'C, will each be able
to combine with an atom of hydrogen to reproduce the original compounds, or with
some other monatomic atom, such as chlorine or potassium, to form such bodies as :

KCl, aCl; KHO, OHO; KH»N; KH«C, C1H»C; &c

It is plain also, since 1 at. of a diatomic element is equivalent in combining capacity
to 2 monatomic atoms, that 1 at. of oxygen, sulphur, ccc^ will combine with 2 at. of
each of these residues, or with two different residues at once, or with 1 at of a residue
and with 1 at. of a monatomic element, forming such compounds as the following :

q(C1 q<H?C q(H»C q<H»0 oJ^3^ &!•

For similar reasons, it is evident that 1 at of a triatomic element will combine with
3 at of such residues, or with 2 at of residue and 1 at of a monatomic element, or
with 1 at of residue and 2 monatomic elementary atoms, e. g, \

CI (H«C (HK3 (H"0 (H»C

a, N^H»0, lBi\BS? , N^H'O, Nm , &c.

[a (h«c (H'»c»t (h (h

In like manner, 1 at of a tetratomic element will combine with 4 at. of residue, or
with 4 at partly of residue and partly elementary, «. g. :

»}:

fCl

fHK)

fHO

CP ^

H » ^

H
H '

H«0
H '

&0.

From all this it follows that these residues or radicles follow the saifie laws of com-
bination with the elementary bodies of different classes as do the monatomic elements
themselves. Further, they combine also with one another according to the same laws
as are followed by elementary monatomic atoms ; that is, they combine together in the
proportion of 1 at to 1 at, 0.y. :

CI + H»0 - C1H»0

Chloride of meUiyL

HO + H»0 - 0H«0

MethyUc ilcobol.

H«N + H»C - NHK)

Metbylamin*.

H«0 + H»0 « H?C«

Free methyl.

But, just as there are not only monatomic but also polyatomie elements, so there
are polyatomic as well as monatomic radides. If we suppose H' to be withdrawn
from each of the compounds HH), H'N, H*C, it is evident that the residues O,
HN, HK), will have the properties of diatomic radicles, the compound radicles HN and
H'C being similar in ueir combining capacity to the simple radicle O, just as the
compound radicles HO, H^, and H*C, resemble the simple radicle CI in their com-
•bining capacity. After the detailed illustration of the properties of the monatomie
radicles given above, it is not necessary to dwell upon the characters of the diatomic
radiclM, since what has been said of the former applies, mutatiz mutandis, to the UUter.
In like manner, the abstraction of H* from H^ and H^C gives the triatomic radides
N and HC ; and the withdrawal of H* from any normal compound leaves a tetratomio
radicle analogous in properties to the simple radicle C, which results from the with*
drawal of H« from H«C.

• H*C» C3 WC » H : It li a residue or radicle comparable to H'C.
t H»»C» s H>«C» - H.

1016 CLASSIFICATION.

Althoofffa, in oonsideriiig the properties and eombinationa of these or of other
pound radicles, we may confine our yiew to their analogies with the dementaij bodiM
and regard their atomicity as an ultimate property, which, like the atomieil^ of the
elements, is not to be explained, it is easy to see that the atomicity of the raaides of
which we have spoken, is the direct result of their composition and the atomicity of their
component atoms. It only requires to be put into words to be at onoe cTident that^ if
one, two, three, or more monatomie atoms be removed firom any normal oompoond what-
eTor, the remainder will be a substance possessing one, two, three, or mora nmts of
atomicity free for combining with other bodies, and therefore, as to its power of com-
bination, exactly analogous to an atom of an element whose atomicity u represented
by one, two, three, or a higher number. Hence the derivation of any oomooinid
radicle determines its atomicity. The maximnm atomicity of a radide may aJso be
always deduced from its composition by means of the formula A 'i- A' -i- A' 4- . . . .
— 2(» — 1), in which A, A', A", &:&, indicate the atomicities of the elementary atoms,
monatomie as well as polyatx>mic, of which the radicle is composed, and n the immber
of atoms it contains. fVom this formula it follows that a compound radicle can never
eonsist of monatomie atoms only ; that radicles containing only diatomic atoms are
always diatomic ; and that the atomicity of radicles containing only teteatomic^ or tetra>
tomic and diatomic atoma, is always represented by 2, 4, or some other even number.
It follows also from the same formula, and from what has been previously said as to the
composition of complex compounds in general, that, starting firom the simple radicles
already described, tiiere may exist series of radicles of the same atomicity in which

I I' I [

the common difference is P", a. ^. 0 ; or ! ' ', e.ff. HN * or : : , e.^, CM'.

For example :

»
1

CIO

C10«

S0«

C10«

ao*

Common differmce, I

HO H

PHK) (in hypophoa- NH«
phites)

Cammim I I I I

difference, I I

CH" CH» CH

C«H» C«H* C*H«

C»H' C«« 0»ff

&e. &C. &e.

From these, considered as primary radicles, fo-called derived {aconfugaie radidea may
arise by equivalent substitution ; for instance, W substitution of CI, Br, or I. for H ; of
OorSforH*; of SforO; of N for H", or for H0«, &c; or of NO«orNH«forH; orof
SO* or CO for H', or generally of any radicle for its equivalent Again, sUU other
radides exist differing from these by containing some multiple of H" (or its equiva-
lent) less than they do, but possessing the same atomicity ; for example, we have
ethyl, C«H», and vinyl, C«H«; trityl, C»H', and allyl, C»H»; propionyl. C«H»0, and
acryl, CH'O ; hexyl, .CH**, and phenyl, C*H*; all of them monatomie radidea.

Hence it follows that triatomic radides may often be isomeric with monatomie
radides; for example, acetyl (Berzelius) C*H*, triatomic, with tmiy/,C^*, monatomie ;
glyceryl^ C*H*, tnatomic, with aUyl, C*H*, monatomie; in like manner, tetratomic
and diatomic radides may be isomeric with each other; for example, tartiyl^ C*HK>*

tetratomic (tartaric add «» ^ ^/ |0^), witk/umaryl, CHK)*, diatomic (fumarie

add a '^ ^f I O*). In such cases, we must suppose that the carbon (or other

pol^tomic atoms) of the radicles which contain a bmaller proportion of hydrogen, or
which have a lower atomidtjr, are more intimatdy combined with each other than they
are in those which, having; the same atomidty, contain a larger proportion of hydrogen,
or with the same composition have a higher a^midty.

We have hitherto spoken only of the composition and atomidty of oomponnd radides ;
it remains to explain a little more fully the grounds upon which their eodstenoe in,
various comnounds is assumed, and what that assumption is intended to imply. It'
has been said that compound ludides are groups of elements which are contained in
a greater or lesser number of bodies, and are tmaltered in the reactions by which one of
ihese is transformed into another. For instance, the bodies of the following series :

C'H*0 Oilofbitter-aUnonda,

C»H*aO Chloride of benaoyl,

C^*0* Benzoic add,

C'H*ON Benzamide,

C*H*ON Cyanide of benzoyl,

CLASSIFICATION. 1017

contain the gronp C'HK) (benzoyl) as a common constitaent which remains unchanged
when they are tnuisformed one into another. Now the reactions by which these trans-
formations are ^ected are essentially quite similar to those by which the following
bodiefl are changed one into another —

EH(?) «... ... Hydride of potassiom.

KGl Chloride of potassium.

KHO Hydrate of potassium.

EH^ Fotassamine.

KCK Cyanide of potassium.

This analogy is hidden if the formula of the bodies of the former series are written
as aboTe ; but if they are written as containing the compound radicle benzoyl, C^H'O,
the analogy becomes at once apparent :

(C'HH))H . . . ]B^dride of benzoyl, or oil of bitter-almonds.

(C'H«0)CI . . . Chloride of benzoyl

!C'H*0)HO . . Hydrate of benzoyl, or benzoic acid.

CHK))H*N . . . Benzamidfi.

(C'HK))^ • • . Cyanide of benzoyl

These latter formula express that the bodies represented by them are Amctionally
analogous to compounds of the monatomic elements, and that they respectively possess
the general properties of those classes of bodies of which HCl, HH), H^, &c, are tiie
typical representatives.

The precise nature of the radicle which any substance is represented as containing
will naturally vaiy according as it is desiz«d to express the relations of the suV
stance in question to this or Uiat series of other bodies, or its capability of undergoing
this or that series of transformations. If, for example, we wish to express the rektion
in which acetic acid stands to aldehyde, chloride of acetvl, acetamide, &c., we shall
do so most simply by representing it as the hydrate of the compound radicle acetyl,

C'H'O, thus, H I ^* ^^^ if it be desired to express also that, by distillation with

excess of alkali, by eieotrolysis, or by distillation with arsenious add, acetic add is
resolved into a compound of the methyl series and a compound of the carbonic series,
and that it can be formed irom sodium-methyl and carbonic anhydride, or from
cyanide of methyl by the action of alkali, this must be expressed by representing the
radide CH'O as composed of the simpler radides CH' and CO ; and if we fiixther
wish to express the analogy of acetic add to formic add, we must write acetyl thus,
C(CH*)0, or as foimyl, CHO, in which hydrogen is replaced by methyl : the whole

formtda of acetic add then becomes ^ H [ ^* Similarly, in order to express the

relations of acetic add to still other sets of compounds, we are obliged to represent it
as containing radides of continually simpler composition, until finally we come to
represent it as built up from elementaiy atoms ; for instance, thus ;

c o o

rm n n
1 1 i 1 I I 1 1

U U il C H

Henoe the idea of a compound radide is seen to be entirely rdative, the same body
from one point of view appearing to contain one compound radide, and fix)m another
point of view appearing to contain a different one. A comparison of the definition
of an elementaiy body, given near the begining of this artide^ with that of a comjponud
radide, shows that compound radides bear the same relation to certainmore or less hmited
sets of chemical processes that the dements bear to all the chemical processes known.
The application of the prindples which we have been discussing, to the classification
of chemical compounds generally, is illustrated by the following table, which is a modi-
fication and extension of that given by Gbrhardt ( 7Vai7^, iv. 612, 613), and reproduced
in Graham's Elements of Chemistry (2nd edit ii. 628, 529). By referring to the de-
tailed comm ntaiies by which (Jerhardt's table of classification is followed in the
places referred to, the reader will be able to understand frdly the meaning of this table
without requiring frirther explanation in this placa

1018

CLASSIFICATION.

dassifieatum

Compounds comparable to Bytfroeliloiio Aoid« I

HCL

ContalnlDg non-
atomic radlclM
(ChlorldM, Hj-
drldcfl, Ac.)

ContainlnK dU

atomic radlclet

(Dlcblorldea,

Dlhjdridet.&c.)

Containing

triatomtcra-

diclet(Trl-

chlortdca,

Trthy-
drldeSfftc)

Containing

tetratomic

radidet

TeCrachlo-

ridet,

Tetrahy-

dride«, Ac.)

Basle obloridesr bydrldaflf ojrttBldeSy *«•

HaUnd salts.

(chloride of

(chloride of
moTCurTt
BgCIS).

or DO.
tasilum, KCl).

MetaUie hydrides (hydride of copper, #«.)

(chloride of
antimony,
SbCP).

(dilorido

of tin.
SnCH).

MetaU proper and aUoys.

(potaMtum.KK.) (tiWor.amal-

gam.)

Aleoliolie oblorldMv bjrdrldeflv 4U».

Halogen ethers.

Compounds compareiie

Containing moo-
atomic radidee
(OxidM, *c)

Containli^dt
atocnic mdtrtea
(Diozldea, ftc)

1. Primarjft ex Ay-
drtUes (hydrate
of potautnm,
KHO).

S. 8eeomdarp,cr
amht/drtdaijoai-
ide of _potaa-
•lum, Ksoa.

_ (h
drat«of

CaHao*).

lime, Ni?CaOS>.

(chloride of ethyl,! (chloride of
C«H»C1). ethjiene,

C«fi<Cl«).

(trichlorhy-
drlne,
C>H»Cl»)

MetaUio eompounds of akohoUradicles.

(pg«.ta««U.,l. (.««j«|gV„,

(biim ethyl,
BKC»H5)>).

(plamb-

Pb(

CTi»)«)

JLold oUortdeflf lajdiidesy *«•

Act-chlorides.

(chloride of
acetyl,
(C<R»0)C1).

I (chloride of
succlnyl,
(C<H40i»)Cl^.

Aldehydes, acetones, ^.

(acetic aldehvde,

(C«H30)Hi

acetone,
(C«H»0)(C^H»)).

(chloride of

fthotphoryl.
PO>CP).

1. jPf Antffy (com-
mon alcohol,
(Gnii)HO).

a. Seeondarw (cam-
moo ether,
(C»H»)»0).

1« J^rAnefw fglicul,
(C«H*>liHi«>.

S. Seeomdag^

Monatomic oxt-
mIu and atni
(chlorate ofpotas-
Bium. (CIO<)KO;
acetate of ethyl,

(C»H»0>(C2H»)0).

Diatomic osyialta
andcchen (sul-
phate of poCaniai
(80S)Kn>S; Md.
pbate of ethyl,
(SO»KC«H»)KP)

1. PrAnory (acetic 11. PrANArjpfMlpharie
add,(C>IPO)UO). add, (SO*)EPO«}.

8. Seoomdan^t
tic anhydride,
(C»IPd>«0).

natc of ethyl<
(C<H^O«>(<?H*)0*).

CLASSIFICATION.

1019

according to Types.

I to IB^ater* H*0.

Containing tri-

atomlc radtdet

<Triozid«s, ftc.)

Containing ta-

tratomle radldet

(Tetrozidett ftc.)

Compounds comparable to Jkinmoiila« WN,

Containing non-
atomic radiclet
(Amines and Amidet).

Containing di-
atomic raudfli
(Diamines and
Dlamidei).

Containlngtriatomic

radiclet (Trlamloei

and TrlamidM).

Cootaining

tecratomic

radicles

(Tetramtnes

andTe-

tramidea).

I saleBMAflfl

k 1. Primanf (by-
drate of
bismuth,

S. Seeamdainfi9ix.
' Ida of bis-

muth, BiSQS).

Baalo nitrldMh pliosplildes, arseoldoav *«•

1. Primary •

1. Frimant (amide of
potasslom, KHSN).

2. Seeowtary.

3. TertiarM (nitride of
potaulum, K'N).

(sincamlde,
inH^KS).

S* SCOOttdOTff*

8. TertUurv (ni-
tride of sine,
_Zn»N«).

!• PriMttttff,

9. Seeomdarff.

8. TerUanf.

1. Primary.

2. 50OMd-

8. Tertiary.

svlplildmh A««

AloohoUo BltrldASf pliospliUleSf 4U).

!•

<yS)Hio»).

S. SMOMdory (ox<
■ Ide of glyceryl,
CC>H»)*0»).

!■ PriMory^

% Secondary,

■nlpfctd— , 4no,

Trlatomle ozT-
aaltsandetners
(phosphate of
bismiith,
(PO)Bl6>i
phosphate
ofethyL

fPO)(C»H»)»0»).

Tetratomie osy-
salts and ethers
(orthosilicatesi
ortbosiUcate
oTethrl,
SKC*H»>«0«).

1. Primary (ethyl-
amine, (C^U»)U<N).

S. Seeomdary (dlethjl-
amine, ((^H»}SHN).

3. Tertiary (trlethyl-
amine, (CSH>)nf ).

1. Primary {MkjU
enedtamine,
(CSU<)U4M<).

2. Secomdary (dl.
ethjlenediarolne,
(OfH*)«H«N»).

8. Tertiary (trl-
echrlenedlamine,
(CTH<>aN«).

L Primary.

2. Secondary,

8. Tfrtfiyy.

I« Primary*

2. SttOMd-
4iyy.

a. Tertiary.

Zntennedlate ottridest pbosplUdeSf Ao.

Dlalkalamldes,

Monalkalamldea
fcthyl-aceUmlde,
(C«H»)(C«H»0)HN;
silver-acetamidk
Ag(CSU»0)HN).

(oxanilide,
(C»0«XC«H»)«N»).

Trialkalamldes '

(ciiranillde.
(C«H»0*)(C«H»)»N»).

Tetralkal-
amldes.

Aeld Bttrld«Sf plio«pbldes« A«.

1. Pf/iivafy(phos<
phoric acid,
(PO)U»0»).

% Seeondary
(phosphoric
anhydride,
(P())«Oi).

1. Primary (tar-
taric acia,
(C<IPO»)H<0«).

% Secondary*

I. J^rAmnv (acetamlda,
(CsU>0)H>N)r

2. Seoondarv (dlaeeta-
mIde,(C<£PO;SUN).

3. T«nlefy(dlben|0]rl-
sulpho-Mienylamidr,
(C'H%)«(0»H»SO«)N).

1« Primary
(ozamlde,
(C«0«)H«N«).

2. Seeondarum

3L Tertiary,
(trlsttocinamlde,
(C«H«0«)>N«>.

1. iYMMfy (phot-
photrlaroide,
(PO)H«N«).

t. Tertiary,

1. Primary,

% Second'
ary.

8. Tertiary.

1020 CLASSIFICATION-

The groups into which chemical sabstances are here divided, may be cooAdcred as
representing the principal Tarietiea, but they are far from including all ohemiral eom-
pounda. By means of polyatomic radicles, molecules may be built up of mudi greater
complexity than any shown in this table. There appears to be no ansignable limit to
the number of such compounds or to the degree of complexity which tney may readi.
Without discussing these bodies at length, we shall be able, by a few examples, to iUns-
trate their nature and tJieir relation to more simple substances. One of tne most re-
markable series of bodies of the kind to which we refer, are the polyethylenic aieohoU
of Louren90 and 'Wurtz. These chemists hare shown that ^yool, (CH*)HH>^ is able
to fix upon itself the elements of several molecules of oxide of ethylene, so as to give
the following series of products :

(C«H«)«H*0« (C»H*)»H«0* (C*H«)«H«0» (C«H«)»BTO« (C*H*)«H*0»

OieihTleolc TriethrleDie ^etnih^lenlc PaiitaUiylailc Bcucbylenic

•IconoL alcoboL mkohol. aleohoL alcohal

The principal transformations of glycol (monethylenic alcohol) itsdf are most oout^
niently expressed by representing it as containing the diatomic radicle etbylene, (7H*.
With this radicle we must suppose the 2 at. of oxygen contained in glyool to be com-
bined in such a manner that half the combining capacity of each is saturated by half the
combining capacity of the radicle, the other hiuf of the combining capacity of each atom
of oxygen being saturated by an atom of hydrogen. This yiew of the oonstitution of

H [O

glycol is expressed by the following formula^ (CH*)"} . Thus regarded, glycol may

H r

be compared to water by representing it as two mol^ules of water in which H' is re-
placed by (C'H*)". The polyethylenic alcohols then become comparable to glycol if
yiewed as 3, 4, 6^ &c., molecules of water in which respectiyely {C*H*)\ (C*H*)",
(C*H*)\ &c., repUces an equivalent quantity of hydrogen. This comparison is ex-
pressed by the formuln by which these compounds are represented abore; bat their
relation to glycol becomes perhaps still more apparent if the same formule be written
a little differently, so as to be directly comparable with that last giren for ^yeoL
Below are the formuln of some of them so written, side by side with sulphur-com-
pounds, which may be regarded as of analogous constitution.

H |0 K ^O

(CH*)"} (S)"}

[O JO

(C^H*)"} (S)"J

[O [o

H (O K {O 0 fo

. (C^E.*y\ (sr{ (C«H<r{ (sy
H \o cifo fo fo [o }o

(C«H<)'> f^^"^

(sr{ (c«H«r{ (S/l (cm.*y{ (sy\

0 qJq H JO- K |0 H JO K {O

Glycol. Chlorotul- Dletbirlenlc H/potolphlto FwleChylode

phurlcadd* alcohol orpousclum akobol ofpotaniam

(■-C^HioOS). (-SfKH)*). (■- Ci«ll*>0«). (s8>KSO^

After these remarks, and what has been previously said about the combinations of
polyatomic elements and radicles in general, the following table will be intelligible
without farther explimation. It giyes a list (probably almost complete) of the known
compounds containing two or more atoms of the same carbonated radicle, and a few
examples of compounds containing radicles composed of other elements, such as sul-
phuryl (SO*) and phosphoiyl (FO). Kany other examples of compounds of a similar
nature might be found among mineral substanQBS both liatural and artificial, and these
can be little doubt that the complex silicates and other minerals belong to this dass
of compounds. In the table, compounds of the same radide are arranffed on the same
horizontal line ;> those referable to the same type are arranged in the same vertical
column.

CLASSIFICATION.

1Q21

■2S

1503
s-S

Oil

&:>;

S)%

5zd

£5:4

&SB 5% &SB

al S| B|

SS lb |g

55 "So*
saali

ero

?. • 8
D 5

« * O ■go

lis

e
hi

aai

6 5

lla
^1

5 3gga^

So©
§1

il
E2

6 8

0!X9

•8

* X 3

O .^ O >^ s

***** «

O »

5 •«

9-s

£a|£

e
o

*ll

.•

iii 8

ill

»|6
5||

1Q22

CLASSIFICATION.

CktuifieaHon aocordinff to Types (contmned).

Compound! containing the

radicle etkylau, (CSR')''

ifiOHtifkued).

Compounds
referable to the ^pe

Cuiapouudi
referable to the type

(C«H«)«
(C«H»)« N^
H3 )

(C2H»)s f N>
Hofinann.

(C«H»)« J *
(C«H<)«N«

Hofioaaniu

A little reflection upon what has been said (p. 101 7) on the natore of oompciBai
radicles, and on the sense in which they are employed, will make it dear tiiat a dassi-
fication of compounds by means of them, aocoiding to types, sndi as that illostnted
in the two tables given, pp. 1018, 1019, 1021, 1022, expresses all we know of thdr
general chemical properties. For the classification of a nnmber of sabstances as a»-
taioing the same radide, expresses that they are mutually convertible by oomparativehr
simple processes, that is, that they are genetically related, — ^while the clawriflration cf
any set of bodies by reference to the same type, expresses that they are capaUe d
undergoing similar transformation, and are therefore functionally related. All oar
strictly chemical knowledge, however, consists in a knowledge (1) of the natore and
proportion of the dements of which substances are composed ; (2) of their genetie
relations, or of the bodies from which they can be formed, or to which they can gxt#
rise ; and (3) of their chemical functions, or the transformations which they cause or
undergo when they react with other bodies. In the foregoing pages, we have aeeoird-
ingly endeavoured to point out the leading prindples which must be kept in view in
dassifying diemical substances with reference to considerations of each of these three
kinds, considering however at the greatest length the daasification of bodies aooordii^
to their composition; partly because much less attention has been paid to tfab
subject, in the existing fiterature of chenustry, than to their genetic and fonctional
relations, but chiefly because composition is the most fundamental of all chemical pro-
perties, and the manner in which all other chemical properties depend upon it is tJw
fundamental problem of chemistry. Throughout, we nave endeavoured to distingui^
between ideas and mere forms of expression, rendered convenient by the existing state
of the sdence.

The order and system which has been followed in this artide, has made it impos-
sible to trace the historical devdopment of the ideas thereih set forth. The follawing
list of Memoirs of theoretical importance will be of assistance to such readers as widi
to trace that development from the birth of Organic Chemistry to the present time ;
many other memoirs of equal importance with some of those enumerated, mig^t have
been quoted; but in a large number of these, references are given which will serre as
a guide to those who wish to pursue the sulject further.

Lavoisier {Cfompound radicles). Traits d^mentaire de Chimie (edit 1789), i. 197,
209.

Dumas and BouUay {Compound ethers), Ann. Ch. Phys. xxxviL 15 (1828).

Wohler and Liebig (Benzoyl compounds), Ann. Ch.Phaim. iii. 249 (1832); Ann.
Ch. Phys. li. 273.

Berzclius {Sadideo/the benzoic compounds), Ann. Ch. Phann.iii. 282; Ann. Ch.
Phys. IL 808.

Berzelius (Sadides of alcohol and its derivatives), Jahresber. (1833), xiiL 189;
Pogg. Ann. xxviii. 617 ; Ann. Ch. Phys. liv. 5 ; extract, Ann. Ch. Pharm. vi 173.

Liebig {Ethyl), Handworterb. d. Chemie (1** Auflage), artide JEther; Ann. Ch.
Pharm. ix. 1 ; JPogg. Ann. xxxi 321 ; Ann. Ch. Phys. Iv. 113 (1834).

Liebig {Acetyl, constitution of acetic acid, &c.), Ann. Ch. Phann. xiv. 133 (1835);
Pogg. Ann, xxxvi 275.

Dumas {Substitution), Ann. Ch. Phys. Ivi 143 (1835); Traits de Chimie appliqnte
aux Arts, v. 99 ; J. pr. Chem. vii 293.

CL AUSTH ALITE — CLAY. 1023

Lanrent (Nueieus theory), Ann. Cli. Phys. bd. 125 (1836).

Gerhardt (Conjugated compounds), ibid, Izxii. 184 (1838).

Bumas {Subsiiiution), Compt rend^ x. 149 ; Ann. Oh. Pharm. xxxiil. 259 (1839).

Gephardt (^Aiomo weights of oxygen, carbon, &c), Ann. Oh. Phys. [3] vii. 129;
riii. 238 ; Precis de Chimie organiqne (1844), i. 47.

Gerhardt (Homology), Precis, ii 489.

Lanrent (Law of even numbers of atoms ; nature of the elements in the free state ;
monads and dyads), Ann. Ch. Phys. [3] xviii. 266 (1846); Chemical Method, 46—96,
et passim,

Wnrtz (Compound ammonias), Compt. rend, zzyiu. 233, 323 (1849); zzix. 169;
Ann. Ch. Phys. [3] xxx. 443 ; Chenu Soc Qu. J. iii 90.

Hofmann (Compound ammonias), PhiL TraiiB. 1850, i. 93; Chem. Soc. Qn. J. iii.
279.

Williamson (Mixed ethers, etherificaUon), Chem. Soc Qil J. iy. 106, 229 (1851).

Williamson (Constitution of salts), Chem. Soc. Qu. J. ix. 350 (1851).

Gerhardt and Chancel (Constitution of organic compounds), Compt chim. (1851)^
vii. 65.

Gerhardt (Basicity of acids), Compt chim. (1851), vii 129.

Gerhardt (Anhydrous organic acids; classification by types), Compt rend, zzziv.
755, 902 (1852^ ; Chem. Soc Qu. J. y. 127, 226 ; more fully Ann. Ch, Phys. [3]
zxxyii. 245 ; Damas's Beport, Compt rend, xsxyi. 505.

Berthelot (Synthesis of fats; nature of glycerine), Ann. Ch. Phys. xli. 216
(1853—54).

Odling (Constitution of salts ; polyatomic radicles), Chem. Soc Qn. J. yii. 1 (1854).

Wurtz (Theory of glyoerin»<ompounds ; polyatomic radicles), Ann. Ch. Phys. [8]
zHii 493 (1855).

Wnrts (Mixed radicles), ibid. zHy. 275.

Gerhardt and Chiozza (Amides), ibid, zlyi. 129 (1855 — 56).

H. L. Buff (Polyatomic radicles), Proc Roy. Soc yiii. 188 (1856).

Wurtz (Diatomic alcohols), Compt. rend, zliii. 199; Ann. Ch. Pharm. c 110; more
fully, Ann. Ch. Phys. [3] ly. 400 (1856—59).

Kekul^ (Mixed types, radicles, &c), Ann. Ch. Pharm. ciy. 129 (1857).

KekuU (Ditto; tetratomic character of carbon), ibid, cvi 129 (1858).

Couper (Atomicity of carbon and oxygen), Ann. Ch. Phys. [3] liii 504 Qfi^8);
Ann. Ch. Pharm. ex. 46 (here followed by crittqne by Buttlerow, 1859). *^

Kol b e (Constitution of lactic acid), Ann. Ch. Pharm. cix. 257 (1859) ; same subject,
ibid, cxiiL 223 (I860).

Foster (Nature of radicles and types), Brit Assoc Beports, 1859, 1.

Wurtz (Basicity of acids), Ann. Ch. Phys. [3] li. 342 (1859).

C ah ours (CoTnbining capacity of the dcTnents; limits of combination), Ann. Ch.
Phys. [3] Iviii. 5 (1860).

Frankland (Same subject), Chem. Soc Qu. J. xiiL 177 (1S60).

Wurtz (Constitution of lactic acid), Ann. Ch. Phys. [3] lix. 161 (1860).

C ah ours (Same subject), Ann. Ch. Phys. [3] xiL 257 (1861).

Buttlerow (Atomicity of the elements), 2ieit8chr. Chem. Pharm. iy. 549 (1861).

Erlenmeyer (Sam£ subject), ibid, r. 18 (1862).

Kol be (Classification of organic bodies), Ann. Ch. Ph&nn. cxiii. 293 (1860);
Critical remarks by Wurtz, B^p. Chim. pure, ii. 354.

Laurent, M^thode de Chimie, 1844; Cavendish Societ/s translation, 1855.

Gerhardt, Traits de Chimie organiqne, 4 vols. 1853—56; especially i. pp. 121 —
142, iv. pp. 561—808.

Keknl^ Lehrbuch der organischen Chemie, voL i (1859 — 61).

Odling, Manual of Chemistry, part i. (1861). G. 0. F.

I. Native selenide of lead. (See Lbad.)

This term is applied to hydrous silicates of aluminium, produced for the
most part by the decomposition of felspar rocks, and generally mixed with small quan-
tities of other substances, chiefly lime, magnesia, and oxide of iron. The days exhibit
the following general characters: — They are opaque, non-ciystallised bodies, suffi-
ciently soft to be scratched by iron ; they have a dull or even earthy fracture ; they
exhale, when breathed on, a pectiliar smell called argillaceous. The clays form with
water a plastic past«, possessing considerable tenacity, which hardens with heat, so as

to Btrifee lire with sUel. UhtIb snd chalks also soften in water, bnt their paste b v<C
tenacious, Dor does it acquire a liliceons hardnen in tha fin. The uffinitj of \he
etay> for moisture is manifested b; their sticking to ths tongue, and by tht imron
heat oecpssaiT Ui make them perfectlj dry. Those which contain iron ton red wboi
burnt. CIbj is otlea mixed with quartz, and contains flne particles of felsptti, mics. aid
benl, showing that it has been [ni>dnced by the decomposition of felqnr or grsnile.
The princip&l Taricties of clay are the following;

1. Porcelain rarth, the kaolin of the Chinese. — This mineral is friable, mragre totlw
loDCh, and, when pare, forms with difBcnlty a paste with water. It is infOable in ■
[lorcelaio ftimace. It is of a pure white, Terging sometimea npon the yellow or Ah!:-
red. Some Tarieties exhibit Mrticlea of mica, which hetraj their origin to be &oa
felspar or graphite gmnite. Porcelain claj scarcely adheres to the tonj^ne. Sppotr
gravity 2'2. The average composition of kaolin, when separated from free silica and
undecomposed felspar, is 47 per cent, silica, 40 alumina, and 13 water, agreeii^
with the fbnnnla Ai'0*.2SiO' + 2 aq. It may be supposed to be fonned trom orthoelaiv.
K'O.Al'O'.eSiO', by abstraction of the whole of the potash and I of the silia. and
addition of 2 at. water. Some varieties, however, exhibited a different c:oBipoait)<!ii ;
thoa the kaolin of Passsn contains, according to Fuchs, ii-BB per canL SiO*, 3SS3 A1H)>.
I'OO Fe'O', and 1B'60 water, beeidea DBS carbonate of calciom, a compoaitjan whifh
may be approiimBtely represeated by ths formula 4Al'0'.9SiO*4- 12aq. Fom-l^m
cUv from Gutenberg, near Halle, eontaina, according to Bley, 39'02 SiC, 45-00 Al-U".
and 10-00 water, together wit^ 0-07 carbonate of calciiun, 3'3li carbonate of magOFeiim.
and O'lS sesquioxide of iron. af;Teeins approximately with 2Al'0'.3SiO* + 3aq. fRam-
miltberft Mintralehmiit, p. £74). la two specimens of Chinesa kaolin, Ebelmea
and Salvitat (Ann. Ch. Fhya. *txi 267) found 73-4 and 80-7 SiO*. 44-fi A1*0*, 14-4
and 120 water; in these the qnontity of silica is twice as great, inproportioD to Itie
alumina, as in the ordinarr fonuula of kaolin (Dana, iL 290). ^obn is Josod ia
primitive mouataina, amid blocks of granite, forming interposed strata. Kaolins an
sometime* preceded by beds of a micaceous rock of ths texture of gneiss, bnt red and
very Mahle. This remarkable disposition haa been observed in the kaoliD quarries (t
China, intboseof AIeD^n,andof St. Yrieui, near Limoges. The Chineae and Japanas
kaolins are whiter and more onctuous to the tonch than those of Europe. Hie Saxoa
haa a slight tint of yellow or carnation, which disappears in the fire, and therefore ii
not owing ta metsllic impregnation. At St. Yrieux, the kaolin ia in a stratum, and
also in a vein, smid blocks of granite, or rather the felspar rock which the Clun«ee
call ptiunlze. The Cornish kaolin is very white and unctuous to the toocb, and is
obviously formed by the disintegration of the felspar of granite.

2. fli<(er«' clai/, or plattic day. — The claja of this variety are compact, smooth, aad
almost unctuous to the touch, and may be polished by ths finger when they are diy.
They have a ^^t oSuitj for water, form a tenacious paste, and adhere stron^y to
the tongue. The paste of some is even slightly transparent. They acquire great so-
lidity, but are infusible in the porcelain furnace. This property dialmguiahn them
&om the common claya employed tor coarse eorthenwaie. Some of Uiem remain white, or
become so in a high beati others turn red. Specific gravity about Z. The slaty potters'
cUy of Werner has a dark ash-grey colour ; principal fracture imperfectly eon^oidal.
cross fracture earthy; fragments tabular, rather light; it feels mom greasy than
common potters' clay. Vauqnelin's analysis of the plastic day of Forges-Iea-Eaui,
employed for making glass-house pots, as well as pottery, gave 16 alomuu, 63 silica.
1 lune, B iron, and 10 water. Another potters' clay gave 33-2 and43'fi, of alnmina and
silica, with 3-6 lime.

/Vre-cAiy is aveiy refractory plastic clay, much used in the manufacture of firo-bricka.
glass-house pots, fee. In this country it lies immediately beneath the coal, each bed
of which rests upon a stratum of this clay, hence called in the mining distiicta tmdrr-
day. The Stourbridge clay is of this character. (See FlB^CLiT.)

3. Loam, — This is an impure potters' clay miiedwitb mieaand iron ochre. Coloor
yellowish-grey, often spotted yellow and brown. Massive, with a dull glimmering
lostro from scales of mica. Adheres pretty strongly to tha tot^ne, and feels slightly
greasy. Its density is inferior to the preceding.

4. runr^afcEf cjuji is striped or spotted with white, red, or ycQow. Uasaive, with »•

earthy fracture, verging on slaty. " " ' ' " ' "

Feels glighUy greasy, and adhen
Upper Lusatia.

5. Siaii day. — Colour grey, (

meting from interspersed mica, ^, ^ j.

Fragments tabular. Opaque, soft, sectile, and easily broken. Specific gravity iS.
Adheres to the tongue, and breaks down io water. It is found along with coal, and is
the floeti trap ibrmation.

CLAY-SLATE — CLINOCHLORE. 1025

6. Clajf stone, — Ck>loiir gtej, of TarionB sbades, sometimeB red, and spotted or
striped. Massive. Lustre dull, vith a fine earthjjr fracture, passing into fine-grained
uneTen, slaty, or splintery. Opaque, soft, and easily broken. Does not adhere to the
tongue, and is meagre to the touch. It has been found on the top of the Fentland
hills in Scotland, and in Qermany.

7. Jdheaive slate. — Colour lignt greenish-grey. Internal lustre dull; fracture in
the large, slaty; in the small, fine earthy. Fragments sUty. Opaque. Streak
shining. Sectile. Easily broken or exfoliated. Adheres strongly to the*tongue, and
absorbs water rapidly, irith emission of air bubbles and a crackling sound. It is
found at Montmartre, near Paris, between blocks of impure ^psum, in large straight
plates like sheets of pasteboard ; also at Menilmontant, enclosing menilite. Klaproth's
analysis giyes 62*5 silica, 8 magnesia, 0*5 alumina, 0*25 lime, 4 oxide of iron, 22
water, and 0*75 chareoaL Its specific gravity is 2-08.

8. Polishing date of Werner. — Colour cream-yellow, in alternate stripes. Hassive.
Lustre dull. Slaty fracture. Fragments tabular. Very soft, and adheres to the
tongue. Smooth, but meagre to uie touch. Specific gravity in its dry state 0*6 ;
when imbued with moisture 1*9. It has been found only in Bohemia. Its consti*
tuents are, 79 silica, 1 alumina, 1 lime, 4 oadde of iron, and 14 water.

9. Common day may be considered to be the same as loain, — Besides the above, we
have the analyses of some pure days, the results of which show a very minute quan-
tity of silica, and a large quantity of sulphuric acid. Thus, in one analysed by Bu-
cholz, there was 1 silica, 31 alumina, 0'5 lime, 0*5 oxide of iron, 21*5 sulphuric acid,
45 water, and 1*5 loss. Simon found 19*85 sulphuric acid in 100 pts. These clays
must be regarded as basic sulphates of aluminium. U.

For analysis of various days, see Ur^s Dictionary o/Arts, Manufactures and Mines,
i.691.

Argillaceous schist; the Argitlite of Kirwan. — Colour bluish-
msj and greyish-black of various shades. Massive. Internal lustre shining or pearly.
Fracture foliated. Fragments tabular. Streak greenish-white, (^aque. Soft. Sec-
tile. Easily broken. Sonorous when struck with a hard body. Specific gravity 2*7.
Its constituents are 48*6 silica, 23*5 alumina, 1*6 magnesia, 11*3 sesquioxide of iron, 0*5
oxide of mansanese, 4*7 potash, 0*3 carbon, 0*1 sulphur, 7*6 water and volatile matter.
Clay-slate melts easily before the blowpipe into a shinins scoria. This mineral is ex-
tensively distributed, forming part of both pimitive and transition mountains. The
great beds of it are often cut across by thin seams of quartz or carbonate of lime,
whidi divide them into rhomboxdal masses. Good slates should not imbibe water. If
they do, they soon decompose by the weather. U.

See Ieok.

A mineral from Peru, occurring erystalliised and as a crust } of an
inch thick on quartz. It appears to be composed of the sulpharsenites of copper and
sulphantimonites of copper and lead. The crystals belong to the regular system, being
combinations of the tetrahedron with the rhombic dodecahedron. Colour bladdsh-
grey. Streak the same. Lustre metallic Hardness - 2*5. Sectile. Melts easily
before the blowpipe, and gives the reactions of lead, arsenic, and antimony. With
soda it yields a metallic elobule, which becomes dull on cooling. Possibly a pseudo-
morph of fahl-ore. (W. jT Taylor, SilL Am. J. [2] rrix. 867.)
C&BAVAaa or omTSTA&fl. See Cbtstaixoobafht.

Soda-felspar. (See Fxlspab.)
Syn. with blende or native sulphide of zinc (See Zino).

JKFHOX. The young branches of Clematis flammtUa, CI, in-
talba, CI, vitieella, CI. ereeta, &&, yield by distillation with water, a liquid which has a
sharp taste, a punsent odour of radish, and reddens the skin ; when exposed to the
air, it loses its acidity, and if left to stand in dosed vessels, deposits white scales and
flocks of clematis-camphor. (Braconnot, Ann. Ch. Phys. vi. 734.)

^'"-*™** — A bitter substance, perhaps CH'^O*, obtained by Walz from

the root o£ Aristoloehia dematitis (i. 357).

CXAVOBKAJI H ITM. Syn. with Maboabitb {q. v.)

O&nnuiTOn or MIOVOIiXTB is a compact felspathic rock, of grr^ish colour
and smooth fracture, dinking when struck with a hammer, somewhat Uxe a metaL
Specific gravity « 2*2 - 2*4.

OUOrocOi&OBa. A mineral having the same composition as chlorite (i. 913),
but differinff from it in cnrstalline form, inasmuch as it belongs to the trimetric system,
whereas cblorite is rhombohedraL The crystals of dinochlore are hemihedral, and

Vol. L 8 U

1026 CLINOCLASE — CLOUDS

hare a micaoeons stractare, the cnrstaQisinff planes often fenmng eqmlatenl triangieflL
It is optically biaxial, the azij^le between the axes being 84<> 3a (or 80^ to 86^); the
plane of the axes is perpendicular to the deaTage-omfaee, bnt the two axes are ns-
equally inclined to this surface, one at 54^ the other at 30^. It ocems in laige crjatak,
usually having a rhombohedral aspect, and in plates ; often eompoonded, ttie ciyslaJs
giring a second pair of optical axes, making an angle of 60^ with the other. Specific
gravity about 2*7 14. Hardness 2-^2*6. Lostre somewhat pearly. Colour olive-
green. Transparent^ unless in thick plates. Somewhat elastic.

Analyses. — a, b, ttom Chester oounihr, PemmlTania, hj W. J. Craw (SOL Am. J. [2]
ziii 222) ; c, firom Lisgau, Bavaria^ Kobell (GeL Anseige, 1864, Na 49) :

SiO" A1«0« FeK^ CrW Mg"0 H»0

a. 81-84 17-47 8-85 1*69 83*44 12*60 - 100-39
^ , /

i. 31-78 22*71 38*64 12*60 - 100*72

c 33-49 15-87 2-30 066 82*94 11*50 Fe*0 4*25 - 100-40

Before the blowpipe it behares like chlorite, showing tnoea of fhsioii on the edgea
(Dana, ii. 294.)

Syn. with Abxchttb (l 1).

Seybertite^ HcimetUe, Ckrysophane, — A silicate found mt Amity,
New York, in limestone connected with sen>entine» together with augite, hornblende,
spinel, and ^pn^^hite. It forms small tabular crystals or foliated masses* aometimee
lamellar, radiate. Structure thin, foliated, or micaceous, parallel to the base. Aooording
to Breithaupt, the crystals are monoclinic, with the angles between the lateral plants
■■ 94°. Specific gravity i« 3 — 3*1. Hardness » 4 — 6. Lustre pearly, snbmetallie.
Colour reddish-brown, yellowish or oopper-red. Streak unooloured, or slightly yd-
lowish or greyish. Folia brittle.

Closely allied to dintonite are XaiUkophyUUe^ from Slatoust in the Ural, where it
occurs in implanted globoles, and in columnar or lamellar individuals, sometimes en-
closing small hexagonal czystals secondary to a rhombic prism, and Diaterrite or ^ron-
ditite, occurring in the Fassa valley, Tyrol, in hexagonal prisms of specific gravity
3*042^ — 6*061, and hardness » 6 on the base, 6 — 6-6 on the sides.

Analyses, — a, Seybertite, by Clemson (SilL Am. J. xxiv. 171).— 5f HcHmesUe^ by
Kichardson (Bee Gen. Sci. May, 1836).— c, Clintonite, by Brush (SilL Am. J.
[2] xviiL 407).— <2, Xanthophyllite, by O. Bose (Pogg. Ann. L 664).— < IHsUrriU or
£randisUe^ by E obeli (J. pr. Chem. xli. 164):

Ca«0 K*0 N^O HSO F

10^ — — W '- B 98-7

1145 — ^ 4-M 0^ a SSSS

IS'69 0*S 114 1-04 .- s 100-41

19*16 — 0-61 4*8S ^ = 1 00-57

4*00 0*97 — S 60 ~ » 100

These resolts may be approximatdy represented by the following fozmnhe^ in which
H denotes a uni-equivalent and B a sesquiequivalent metal : —

Clmtomte (Seybertite, Hohnesite) . 2MK).38iO« + 2(3]!P0.2R<0«)

Xanthophyllite 2M«0.3SiO« + 8(8M«0.2RK)«) + 3aq.

Disterrite 2MW.8SiO* + 4(M«O.RH)^ + 2aq.

It is doubtftil whether either of these minerals has been found in an unaltered state.

Clintonite is infusible before the blowpipe, but loses its brown colour and becomes
opaque ; heated in a flask it gives off neutral water. It is oompletdy deeompoaed by
hydrochloric acid.

Xanthophyllite yields green glasses with fluxes: it is decomposed by adds, like
dintonite, but much less easily.

Disterrite when heated gives off water, which is neutral or alkaline, aooording as
the specimen is fresh or has turned red-brown by weathering. B^iore the blowpipe it
•becomes turbid and greyish-white, but does not fbse ; with fluxes it gives the reac-
tions of iron and silica. It is not sensiblv attacked by hydrochloric acid ; but sul-
phuric acid decomposes it when heated with it for some time. {Rammelberfs
Mineralchmie, p. 848.— Dana, ii. 297.)

O&OVBS are masses of air which contain innumerable minute partides of sus-
pended water condensed from a state of vapour, and thus assume the appearance of
white or misty bodies. The forms of douds, which of course d^>end on the form and
motions of the mass of air, were first properly classified by Howard, {Ber^ Cydop^ia,
art. Cloud; Nicholson's Journal^ 1811, xxx. 36 — 62 ; or HotoareTs (Mimate ofLondon^
2nd ed. toL i), whose arrangement we may thus shortly describe.

SiOS

ZrO«

A1«0»

Fe^O* MnSO

Mg«0

\T0

87*6

6-6 —

84-3

19*3»

so»

44-7t

4-80 1*38

9-05

90-18

0-19

88-90

3-87 —

91-86

i6>ao

43-95

9-91 —

19-81

20*00

•-

43-n

3*60 --

95*01

CLOUDS. 1027

CirruB. — ^Parallel, flemous, or diyeiging flbres, commonly called mare-tails^ ooeoiv
ling most diBtinctly in the higher regions of the atmosphere, but sometimes originating
from large masses of other dond at lower elevations. The a^jectiye cirrose may hi
applied to any streaked appearance in clouds.

OwntUus. — Conrez or conical heaps, increasing upward ttom a horusontal base.
This is the most abundant form of doud, generally appearing during the day at a
moderate elevation, and moving along with the current next the earth.

Stratus. — A widely extended oontinuous horizontal sheets either lying upon the sur-
face of the earth as a mist, or elevated at any height in the atmosphere.

Cirroatratus. — Stratus streaked with the fibres of the drms. This form of cloud,
generally oocnirtng at a great elevation, and consisting, therefore, of partides of ice,
18 the cause of solar and lunar halos, and also of the parhelion and paraselene.

CumtUostratm. — Jl cumulus the summit of which spreads laterally, producing an
anvil-shaped doud. This kind of doud is very likdy to turn to the following :

Nimbus, Cumul<heirro^tratu»f Bain, or I%undereloud is a doud or system of douds
forming a great sheet or mass, mostly cumulose, but with lateral stratose extensions,
and with tufts of cirrus spreading from the summit It indicates a great distur-
bance of the atmosphere, caused by a violent upward current in the centre of the
doud, and is generally accompanied by wind or squalls.

The following Airther statements are on the authority of Howard.

The cumuiuaatLB the densest structure, and is formed in the lower atmosphere. A small
irregular spot first appears, and is, as it were, the nudeus on which the mass increases.
The lower surfkce continues irregularly plane, while the upper rises into conical or hemi-
spherical heaps, which may afterwards long continue nearly of the same bulk, or rapidly
rise into moxmtains. They will begin, in fkir weather, to form some hours after
sunrise, arrive at their maTimnm in the hottest part of the afternoon, then go on
diminishing, and totally disperse about sunset Previous to rain, the cumulus increases
rapidly, appears lower in the atmosphere, and with its snr&ce Aill of loose fleeces or
protuberances. The formation of large cumuli to leeward in a strong wind indicates
the approach of a calm with rain. When they do not disappear or subside about sunset,
but continue to rise, thunder is to be expectisd in the night.

The stratus has a mean degree of density, and is the lowest of douds, its inferior
surface commonly resting on the earth or water. This is properly the doud of night,
appearing about sunset It comprehends all those creeping mists, which in calm
weather ascend in spreading sheets (like an inundation of water), from the bottom
of valleys and the smrfaces of lakes and rivenk On the return of the sun, the level
surface of this cloud begins to put on the appearance of cnmulus, the whole at tiie
same time separating from the ground. The continuity is next destroyed, and the
cloud ascends and evaporates, or passes off with the appearance of the nascent cumulus.
This has long been regarded as a prognostic of fair weather.

The cirrus having continued for some time increasing or stationary, usually passes
either to the drro-cumulns or the cirro-stratus, at the same time descending to a
lower station in the atmosphere. This modification forms a veiy beautifdl sky, is fre-
quent in summer, and attendant on warm and dry weather. l%e cirro-stratus, when
seen in the distance, frequently gives the idea of shoals of fish. It precedes wind
and rain, is seen in the mtervals of storms, and sometimes alternates with the drro-
cnmulus in the same doud, when the different evolutions form a curious spectacle.
A judgment may be formed of the weather likely to ensue, by observing which
modification mrnSiM at last

Howard did not explain the special causes of forms of douds above described, nor
can we point to more than one or two attempts at all sound and sdentific to accom-
plish this. In two papers, however, in the PhUosopMeal MagazinB (4th ser. xiv. 22 ;
XV. 241), it is shown, by analogical experiments with liijuids, that the cirrus arises from
the interfiltration of masses of air saturated with moisture, and not in equilibrium ;
the stratus, from mixture or contact of layers of air tranquilly moving on or lying
over eadi other, while the cumulus arises from the violent ascent of columns of air
in the atmosphere. The nimbus, rain, or thundercloud appears to be formed in like
manner.

Very little is known of the natore of douds from which dow long-continued rain
falls, as it 80 commonly does in London, but the doud is probably for the most part
stratose.

More particular accounts of the phenomena of the douds and weather must be
' sought in works on meteorology, among which by fax the most philosophical and reliable,
is Sir J. Herftchers Essay on Meteorology (Encyc. Brit 8th ed.). To this Essay
we are indebted for some of the following remarks.

It is more within the province of the chemist to consider the nature of the maUer

3 v2

1028 CLOUDS.

of doadfl. Meteorologists have geoeraUy assumed, as an imsnpported dogma^ that
doiid particles are smidl yesides or watery bubbles. Sanssure, indeed, is said to baTo
examined these yesicles in the mists of high mountains, and to have found them Tarj-
in sise from j^ inch to the ^hs ^^* occasionally however attaining the aiae of a
pea. Now although no observer is in general more deservedly trusted than Sanaaaixe,
his unsupported announcements must not always be adopt-ed as oondusive^ and we are
quite unaware of any one else having witnessed vesides of appreciable saze floating in
tne air and forming clouds or mists. It is also stated {Gmam's Elements, 2nd ed.
i. 314), that the vesides maj be observed bj a lens of an inch focal length, over tlie
dark surface of hot tea or oo£fee, mixed with an occasional solid drop, which contrasts
with them. Having tried this, we witnessed a white dust of wateiry particles of
uniform size, blowing about over the sui&ce of the coffee, or rising in little wreaths
and whirlwinds like dust on a wind^p" day, but we saw no drops appearing solid as con-
trast^ with the rest, and were incUned to consider them all solid partides of about
the diameter of ^^ inch. No one has ever suggested how the vemdes are formed,
nor is it easy to conceive any possible mode of their formation.

In favour of the vesicular tneory, it mav be urged that rainbows are at least Toy
sddom produced when the sun shines on doud or on steam, although a rainbow is ex-
hibited under such circumstances by the minutest rain and by spray from a fountain
or waterialL Sir J. Herscbd suggests that the partides may be of an order of emaU-
ness comparable to the lengths of the light-undulations, which are on an average
about ^xj^ inch long. Hence, he infers, the refractions and reflections of light whidi
cause the rainbow would not take place. (See also Haillard, Con^tee JSendue,
xliii. 906.)

The existence of vesicular vapour oi water seems, however, to have been disproved
by the microscopic observations of Dr. A. Waller (PML Trans. czxxviL [1847]
p. 23), which later writers have overlooked. Steam bemg thrown upon a soi&oe a£
Canada balsam, the partides of water became fixed and were easily examined in the
microscope. It was concluded that whenever we are enabled to inspect the minutest

Eartides of wativ arising from condensed steam or vapours, they consist of minute
quid globules without any appeiurance of internal cavity.

The suspension of the douds is in no way mysterious, and arises only from the
enormous comparative resiBtanoe which the air oners to the motion of a very minnte
body, as Prof. Stokes has lately shown (Cambridge FhiL Trans, vol viiL ix.) A
globule of water of the diameter of ^^ inch, in frlling through the air, would have the
maximum velocity of about *067 inch per second, which is quite inu>preciable com-
pared with the ascensional movement of the air, which is generally taking place
in all large masses of doud The wateiy partides, or the air, generally both, must
then be in motion in every cloud (See aLso PhiL TnnB. vol Iv. [1765] p. 162.)

No satisfactory reason has ever been given why the douds only sometimes dis-
charge rain, but it is not difficult to see that if all the p«rtideB were of equal sixe, thej
would all subside at exactly the same rate, and no collisions could take place. But if
a further set of partides were precipitated of a different size they would move at a
different rate, and encounter the other partides ; many partides would thus coalesce
into drops of suffident siae to fall rapidly, and receiving accretions in their passage
through the air, reach the sur&ce of the earth as rain. The coalescence of minute
globules vastly diminishes their surface as compared with their bulk ; it is easy then
to understand how electric tension existing on the surface of .doud partides is so in-
tensified when rain falls as to occasion lightning. This theory of the thundercloud
was suggested as earlv as 17^2 by Eeles (PhiL Trans, p. 527), and it is repeated in
the papers in the Pkuoeophioal Magaeine before referred to.
There are two principal ways in which doud partides are produced :

1. A gas in changing its volume also changes its temperature, and may thus be
unable to sustain in the gaseous state all the aqueous vapour which is diffused through
it Thus, if the air wit£m the receiver of an air-pump be moist> a few strokes of ^e
pump will produce a visible mist. In the atmosphere, by far the largest masses of douds
are mus produced by columns of air rising, and consequenUy expanding and growing
cold as they rise. Fogs, it is also said, may be produced at the sur£Me by sudden
changes of barometric pressure.

2. Two masses of moist air of diffSarent temperatures wiU not, when mixed, sustain
the whole of the contained vapour in the gaseous state : for the maximum tension of
aqueous vapour varies in a higher ratio tlum the temperature. Hence the mean ten-
sion of vapour on mixing, will always be higher than the tension possible at the mean
temperature, and vapour will be condensed until the two are equalised Thus arise
the cirrose and stratose forms of doud, from the mixing of bodies of air under various
circumstances.

Oases have but an inappreciable power of conducting heat A cold surface may

CLOVES — COAL. 1029

indeed eondeiise vapour from the air, as in the formation of dew, bat the water con*
densed will all attadi itself to the cold snrfaoe, and no dond-pazticlefl will be prodneed.
Dr. l^dall having lately proved that gases may radiate heat, it is possible that donds
may be produced in the higher parts of the atmosphere by slow radiation. W. 8. J.

GewursffidkenSL — This oil, obtained by «^i«tniing with
water the bads and flower-stal&s of the dove-tree^ Eugenia oaryophyUata^ or
CaryophylluB aromaHetis, L., is a mixtore of eoffenic acid (g. v.) and a hydrocarbon,
C**H*', isomeric with oil of tuipentine. This hydrocarbon passes over wiUi vapoor of
water, when the erode oil of obves is distQled with potash-ley. It is highly refrac-
tive, has a density of 0-918 at 18<> C, and boils at 1420— 143<>. It is not attacked
by alkalis ; it absorbs a large qoantity of hydrochlorio acid, and without forming a ciys-
taUine compound (Ettling, Ann. Ch. Pharm. Iz. 68). Water distilled from doves
sometimes deposits nacreous scales of eugenin, a substance probably isomeric with
eugenic add.

Accordinff to St en house (Ann. Ch. Fhann. xev. 103), the so-called oil of cinna-
mon-leaf is likewise a mixture of eugenic acid and a hydrocarbon, C**H^'. It has a
density of 0*862, uid boils at 160^ — 165^ G. ; it contains also a small quantity of
benzoic add.

<?X4>VOSUBXXIf • A resinous body produced by the action of sulphuric add on
oil of doves.

See Ltoofodixtic.

A mineral related to analdme (p. 210), occurring in flesh-red
vitreous crystals in the amygdaloid of the Kilpatrick Huls. Specific gravity a 2*166.
Hardness » 8*5. Opaque or subtranslucent. Fragile. Contains 51*27 SiO*, 23*66
Al'O* 7-31 Fe«0*, 6*13 KaH), 1-23 HgH>, and 10*66 water - 9906. (Thomson,
System of Mineralogy, i. 339.)

OVZOZV. CenUntrin, (Horin, J. Chim. mM. iii. 106; Scribe, Compt. rend,
zv. 803). — ^A bitter substance contained in Ckni€nir€a benedtcttu or Cnicus benedietus
(Morin); also in the leaves of Centaurea caleiirapOt and in all bitter plants of the
order Compoeitm, sub-order Cynarooephala (Scribe). Horin fint obtained it in an
impure state by treating the aloohohc extract of Centaureti benedictus with ether,
evaporating, precipitating with sub-acetat« of lead, evaporating the filtered liquid after
fi^emg it from lead, and treating the residue with ether and alcohoL It was after-
wards obtained by Kativelle and farther examined by Scribe.

Cnicin forms white transparent silky needles, inodorous, having a pure bitter taste,
and neutral reaction, easily soluble in alcohol and wood-spirit, very little soluble in
ether. The alcoholic solution defiects the plane of a polarised ray to the right;
[a] «- ■¥ 130*68^ (Bouchardat). It is neailp insoluole in cold water, dissolves
somewhat more easily in warm water. The solution is decomposed by continued boil-
ing* becoming turbid and afterwards depositing a viscid body like turpentine.

Cnicin gives by analysis 62*9 per cent, carbon, 7*0 hydrogen, and 30*1 oxygen,
whence have been deduced the three formula C"H>H)*, C»H»K)», and Cm^Hy. They
all agree pretty nearly with the anal^rsis, but as there is no means of determining the
atomic weight of cnicin, it is impossible at present to dedde between them.

Cnicin submitted to dry distillation gives off vapours and becomes carbonised. Strong
sulphuric add dissolves cnicin with deep blood-red colour, the liquid becoming black
when heated. Strong hydrochloric add is coloured green by it ; if heat be applied,
the liquid turns brown, and oily drops collect on its surface, solidifying in a resinous
mass on cooling.

OO ACMnbUM is a term appHed to anv visdd or curdy mass separated from a
liquid, as cheese from milk, the dot from blood, &c.

OOJkJLm HouUU, Steinkohle, — ^The vast masses of fossil Aid which are stored up
within the bowels of the earth, and in particular constitute so essential an dement of
our national prosperity, areimdoubtedly the result of complex diemical changes, acting
under varying circumstances of temperature, pressure, moisture, &c, either upon vege-
table matter growing on the spot^ or upon the remains of plants collected by the drift of
rivers, &c, into particular localities.

The vegetable origin of coal is beyond doubt^ nor can there be any question as to the
character of the flora of the carboniferous era, about 600 distinct spedes, induding
260 ferns, having been recognised as belonging to that period.

The discovery of distinct ligneous strnctare in most lands of coal appeals^ however,
to be somewhat Questionable ; and although Bischof and others have entered into in-
teresting and highly valuable speculations as to the precise changes, by virtae of which

of wood into coal, MmrHing to Bisduit n»T take plaea in tamr £f-

Oftb.

ceptioD

The

1. By lepuatioD of eutodo «dd and cat6iii«tt«d bj'dMigciL

S. „ „ „ wnter.

S. „ carbontted IiTdiogen and wBt«r.

i. „ „ „ caibonie add.

(For the fonnuLe repreeenting tti«e chaBgea ve refer die reader to BtMchoft Citmied
and Piftioal Geology, voL L p. 27*, el. wj.J

" W^en wood or vegetftble matter, then, u IntUd nnda' cSrenmetaiioea whidi allov
of theextricttiioQ of these snlistaiicee ftom it^ in tlie cooiae of ite decomposilion, it mait
bocomecoDTfrtod into coal; tbeextremeremtltoftlieproMesbtuigtoBiTeiB, flntantlnv
taining pcrhape 94 per oenL of cartMHi, aid fiiultf gnphite^ which u
bon ilself) or tJiHt eubstaiiee minxiledTitli others vnidi an hate excteda

coneiderstion, aa not being amonz the elementa of wood, and which it aaj hare ac-
quired irom eilemal sourcea dnnng the proceag of MnTeraion,

"The great qnantities of cvbomc aaagta (choke-damp), and eartmretted hjdiagi*
(flee damp) met with in coal minea, show the bet of the law extrication of theae lob-
Blances, and corroborates, if need were, this eiplanatioiL BeetsvoirB of thr&r giaci
in a highly compressed state are often found to be pent np in the trtricta mad caritiM
of coal beds. Some beds of ooal are so sstorated with gas, that when they ai« eat
into, it may be heard oodiig &inn erer; pore of the rock, and the ooal is sailed bj
the colliera ' singing cosl.' " (Beete Jnkea, Maimai of Geoiaffj/.)

The natiiral escape of light caihuretted hydrogen, marsh-gas or fiie-dmnp (CH'),
which freqaently bnrBlB forth in Ureo i^nantitiea £Rim the seams of coal oc strata ef
fire-clay which djride them, is the frequent eaose of those tenible accidaite, of wUci
the Lond Hill CoUiery ex{>loeion in lSfi7, uid the atQl mom recent one at Bonadon,
have been the most ealamitons npoD record.

The sudden issue of ess from a blotetr in the colliery adjBoent to that of Xoitd Hill
is thus described. " The fiie-claj of the floor of the seam was seen to hesTC at dif-
ferent points altnig the face, and preeently large fractnraa were nude in it, through
which gas was ejected with great violence and with a sannd very similar to the iKw
of atesm at a high pressure from a boiler." Snbeeqnent to the explosion at Lund
HiU, the peat up gas still issuing within the mine in the higher parts of the woikingB
supported two columns of wat«r 30 feet high, one 10 feet and the other 11 j feet dia-
meter, correepanding to a pressure of about 1 1 lbs. on the sqnafe inch. Tliis gas in «[•
ploding renders unfit for nepiradoiiHO times ite own bulk of air: hence tEe "sAct
damp " of the miner, the vitiated atmosphere produced by the explosion, oftm btal to
those working in other parts of the mine, or to those who deecend into the pits withoat
proper precautions, or until ventilatian has been sufBeient>f re.»tablished.

' ' The subjoined tables, given by Miller, give an idea at the compositioB of wood

re geoloncal stages. The proportion of oxygen diminiabw r^iidly and that
of hydrogen mora dowlv, as the coal passM &om ligute towards anthracite, to whkfa
• — -"* '-tsof nearly pnnearbon."

dinfwnfwn i^f Wood and CoaL

<ha-«m.

Dylmeor

■^sr-

speciecr>*>tr .

»""«■

LMK.

Vua.

Kfi^t.

Yiux.

um„.

■«

■w

i-oa

M»

I-IW

Coke [wr MM

»l-3

vVi^ ' '

, -"•

frSl

»i

S^': .- ]

' ,.

COAL.

1061

Compotition of Coal.

LetmakoMow
ParroiCoal.

MiUer.

Vans.

Caking Coal
Newcastk.

Bichantoon.

10 pard
hanvptoHm

V«QZ.

Netpport
Steam.

MlUer.

5. WaU»
Antkradte,

Vaux.

1-961

itre

1-9B0

l-9;8

1«809

1*899

Coke per cent.

Carbon .

Hrdrogen •

Nitrogen

Oxynn .

Sulphur .

Asb . , .

48-3
78*44
7*69

1 11-761

M48
6-084

60-86
80-07
6-89
9-19
8-08
1-AO
9-70

86-76
1-40

89-91

78-87

8*99

1*84

19-88

•89

l^08

76-10
81-47
497
1*63
8-28
1-10
8-81

99-10

90-99

8-98

0-83
9-98
0-91
1-61

The compoflitioii of ooals yaiies largely, not only in xespect of the relatiye propoitionB
of carbon, hydrogen, oxma and nitxo^ which they contain, but also of the amount
of extraneous matters which constitute the impurities of fuel. These consist of a yari-
able amount of mineral matters which remain after combustion of the ooal, as ash or
" cUnker."

The percentage of ash ranges from about 1 to 30 or 8^, and in some coals, which are
considered too i>oor to be brought to market, to eyen more than this quantity.

It consists chiefly of silicate of alumina, with yariable amounts of oxide of iron.
Vaux found also in many coals traces of fead and copper.

" We haye in nature eyery gradation, from jmre ccral into a mere carbonaceous (com-
monly called bituminous) shale or * batt ' which often contains enough imflammable
matter to giye out flame and support combustion for a time when burnt with better
cobIs, but soon passes into a lump of ash, unaltered in form and not retaining heat
longer than a brickbat would under similar drcumstanoes." Accordingly, the compo-
sition of the ash of coals closely resembles that of the batts, shales, or fircKdays which
usually occur, either as strata aboye or below the coal, or in their " partings " between
the seynal layers of the coal itselfl

The following table exhibits the amount and composition of the ashes of seyeral coals,
compared with that of fire-days and " batts " :

Composition of Coal-ash,

Silica . .

Alumina

Seaquioxide
iron • •

Lime

Ifagneela .

Potash

Soda . .

Sulphuric
acid (an-
hjrdroui) .

Sulphate of
Calcium .

Pboiphoric
add (an-
hTdroua) .

Percentage
of Ash .

NewcMUe
coal after
deducting
Suphurlc
acid.

Tisylor.

Porous
Coal from
Zwickau.

Kramers.

Compact
Coal from
Zwickau.

Kremem

ATorage
of Ave

samples.
Welsh.

IPhlllips.

ATerage
or lire

sampln.
Scoteh.

PbilUpa.

Blue
Shale

Tajlor.

NewnaUe
Fireclay.

Rlehaid-
son.

American
Anitaracite

Fawn.

Ash of

Bitumlnoui

Shale.

Bilston,

Stalfordshlre.

VVilU.

69-44
81-99

9-96

•76

-86

9-48

• •

• •
1-86

60-98
81-68

6-86

1-08

•88

• •

• •
•94

• •
1-74

48-18
99*47

96-88.
9^80
•89

• •
•94

• •
9-97

*
• •

1-89

49-67

(48-66

6-68
108

• •

4-46

•66

8*18

49-63

88*21

• •
8-18
1*41

• e

• «

646

r
1-03

• •

86-98
9619

F^O.l6-98
■67
1-64
984

• •

• •
•

671M
86-09

8-17
1-68
1-78
•

• •

84-80
8448

7-86
9-98
1-80

• •

•

• •

6841
99'88

8-14
»I9
1-83

I 9*19
0-69

traoea.

Chlorine 046

Huspratt states that the ash of lignite yaries from 1 to 60 per cent, ayeraging about
5, and that of bituminous ooal 1 to 2 per cent In addition to these substances, the
mineral matter of coal contains a small but yariable quantity of sulphur, not accounted
for in the aboye analyses, but constituting a most important element as regards^ the
yalue of friel for domestic and technical uses. This remark applies more espedally
to the yalue of coals for metallurgical purposes, particularly for employment in tho

1032 COAL.

blast-ftimaee ; the iionmaster, has learned to eschew such Bamples of ironstone aa
contain any conaiderable percentage of sulphur and phosphoric add ; bat this pre-
caution is wholly inefBsctaal, unless a like care be exercised in the selection of ^a
fuel and fluxes which are to be introduced into the blast-furnace with the ore.

The presence of sulphur is equally detrimental in the manufacture of gas, some por-
tion of it being always eliminated as sulphuretted hydrogen and bisulphide of carbon,
the complete remoTal of which is a matter at once of great difficulty and of the highest
necessitYi while the frequent cases of spontaneous combustion of coals in the hold of
Tessels u probably due, in some measure, to the oxidation of the pyrites viuch they
contain under the influence of a moist atmosphere.

A minor eril is the eyolution, during combustion, of snlphuions acid, a gas wbich is
not only noxious and hurtful to human life, but destructiTe to IxnieEB^ locomotiTe
tubes, and so forth.

Some of the lower seams of the South Sta£Ebrdshire coal beds, otherwise arailable as
good fuel, are unused, because they contain an amount of sulphur which renders it im-
possible to bear the smeU which they exhale during combustion ; whence their local
name of stinking coal.

The mean percentage of sulphur found in the gOTemment inyestigation, under
Playfair and De la Becne, was as below :

Samplw. C<»ftlf. Mean.

87 . . . Welsh 1-42

8
28
17

Derbyshire 1-01

Lancashire « . 1*42

Newcastle « 0-94

Scotland 1*4^

The following are other determinations of sulphur in coals : —

^ Men.

4 samples from North Wales, Ruabon -79

Lignite from Bovey (Yaux) 2*36

Boghead (Miller) 0-96

Wigan cannd (Yaux) 1*50

10 yard Wolyerhampton 0*39

„ bottom 2*67

Newport steam coal (Miller) 1*10

Anthracite, South Wales (Yaux) -91

" The frequent occurrence of iron p3rrites in coal shows that its formation at the
cost of organic remains is a very frequent phenomenon. This formation of iron pyrites
can only bis explained by the presence of sulphates ; and so far as it goes on in the aea,
only by the decomposition of sulphate of calcium.

The minor varieties of coal are almost inflnite in number, and it is said that fkdl a
hundred different kinds are sent into the London market The following appears to be
as satisfactory a classification of the more important kinds as is possible, together with
an indication of their characteristic differences, and of the localities whence they are
obtained : —

1. LiONrni or BsowN Coal generally retains in some degree ita iMnAllfff and woody
structure. Yields a powdery coke in the form of t&e original lumps. Brittle, bums
readily, but often contains from 30 to 40 per cent water.

Occurs in England chiefly at BoTey Heathfield, in Devonshire^ where it has long
been used as fdd in the local potteries ; the supply is now, however, falling off Its
other chief localities are Westphalia, the Hessian States, Lower Austria, Russia,
Spain, Portugal, Italy, the Tapper Missouri Yalley, New Brunswick (impregpiated with
<^PP^)» Qi^senland, China, and the Burmese Empire^ and in Centnl Ama^r^t*^ in the
province of Panama.

2. BiTuicnrous or CAxma Coals. — ^The most extensively diffused and valuable of
English coals. These are of various shades of brown and black, emit much gas on
heating, and hence are prized as *' gas-coals ; " they leave a coke more or less lustrous
and Auied, or caked together. Their fracture is generally uneven and their hutre
resinous. The coals of this class are subdivided into :

Caking Coal, which splinters on heatinff, but the fragments then Aise together into a
semi-pasty mass. Its chief sources are uie Newcastle and Wigan districts, along the
banks of the Tyne and Wear, and the north of the Tees.

Cherry Coal or Soft Coal. — ^Lustre very bright Does not fuse. Ignites well and
bums rapidly. Occurs in Glasgow, Staffordshire^ Derbyshire, Nottingham, L«iica-
shire, &o.

COAL. 1033

Sjdintf Bouffh or Hard €W.— -Black, and of grHstening fracture. Doee not ignite
readily, bnt bums np to a dear hot fire, constitating a good house coaL Occurs
in the Glasgow field, in Shro^hire, Leicestershire, Warwickshire, Derbyshire, and at
Nottingham, and constitatea in particular the bulk of the great coalfields of North and
South Staffordshire.

Cannel Coal; Parrot coal of Scotland. — Of dense, compact, and even fracture, con-
choidal in eveiy direction. Takes a polish like jet. S^lint^ in the fire and bums
clearly and brightly. The chief localities in Great Britain are Wigan, and other parts
of Lancashire, West Glasgow, and in smaller quantitieB at Coyentry. It is found also
in Kentucky.

The Tazious kinds of bituminous coal constitute also tiie bulk of the immense coal-
fields of North Americai compared with which the most eoctensiye fields of the Old
World are insignificant These are the Alleghany or Appaladiian field, and those of
Pennsylvania, Illinois, New Brunswick, and Noya Scotia. In South America they
occur m the proyince of Chili. They compose also the south side of the South Wales
basin ; are foimd in Connaught and Ulster, and on the European continent in Belgium,
France, Prussia, Sweden, Bussia, and Spain, finally, the great coal range of New
South Wales is supposed to belong to this dass.

4. AmsBAcnii. Stoks-coal or Cuuc — ^The densest^ hardest^ and most lustrous
of all yarieties. Bums with yeiy little fiame or smoke, but giyes great heat Con-
tains yeiy little yolatile matter. Splinters when heated, and icnites with difficulty.
Colour deep black, fracture lamellar, parallel to the bed of the deposit^ conchoids! in
the cross fracture. Applied sucoessfuUy to smelting, and much yalued as a steam coal
in the nayy. Its most extensiye deposit occurs oyer yast tracts of North America,
chiefly in Fennsylyania. It constitutes also a laige portion of the yield of the north-
west portion of the South Wales coalfield. A fiirther deposit occurs oyer a tract of
about 12} miles in Beyonshire, in the neighbourhood of Barnstaple Bay and Bideford.
Its other situations are Leinster andMunster in Ireland, and some districts of France,
Sweden, and Portugal.

ff. Stbah Coai. approaches nearly to anthracite. It does not crumble into small
pieces under friction, and is hence well adapted for stowage. It also emits little
smoke, a point of great importance in nayal warfare, where the smoke of ordinary coals
would reyeal the position of yessels to a distant enemy. Its chief locality is the
north-west of the »)uth Wales basin and tibe north of the Tjtlq and Bly th district

In addition to the aboye-named yarieties, we must mention the remarkable deposit of
Bathgate, near Edinburgh, commonly known as the *'Torbane hill mineral or Boghead
cannel coal," respecting which a curious lawsuit arose upon the question whether or
not the substance was to be considered as " coaL" It is of a dull brown colour in the
upper part, and black in the lower part of the seam, and of low specific gravity. It
contains about 20 per cent of aluminous ash, which remains after ignition in the
form of the original lump, retaining 6 to 10 per cent of carbon. About 70 per cent,
therefore, consists of volatile matter, whence uie great value of the mineral for two pur-
poses ; 1st for gas making ; 2nd for distillation, by Young's process, in dose vessek at
-a low temperature, whereby a large number of liquid hydrocarbons of various densities
and boiling points are obtained, fit respectivdy for illuminating and lubricating pur-
poses, together with paraffin and other solid products.

The analyses already given fairly represent the ordinary composition of the several
dasses of coals.

Valuation of Coal.'-^A. ready method of accuratdy estimating the general value of
coal as fbel is yet a desideratum. Its elementary analysis affinds the means of cal-
culating its theoretical heating power; but it is found in practice that the amount of
work indicated by this result can never be obtained, and further that the condition of
mechanical division, draught of furnaces, and many other extraneous circumstances
affect the result so lai^pdy, that the actual work obtained sddom bears any palpable
relation to the theoretical indication.

The weight of water in pounds raised otie degree in temperature by the combustion
of 1 cubic mdi of each of a laige number of combustible substances, and also by such
a weight of each as combines with 1 cubic inch of ozygen, has been determined by
the direct experiments of Lavoisier, Laplace, Despretz, JDulong, Rumford, Begnault,
Andrews, and others, the general prindple of their methods consisting in the use of
an apparatus wherein the entire heat of combustion was absorbed by a known weight
of water, the whole arrangement being protected from the influence of external changes
of temperature, and the increase of temperature of the water being known b^ the
simultaneous indication of several delicate thermometers suspended in it (See Hb^t.)

The method of Berthier, though only approximative, affords useful indications wh^

1034

COAL.

>»

tf
If

31*8 Ibe. lead

81-2

30-9

!•

28-3

27-2

24-9

81-6

30-6

••

•nplied, with certam precantioiia, to Tarious samples of the same dass of ooal or £msi
tne same mine.

It is based apon the reduction of oxide of lead by the carbon and hjdrogtea of the
fuel, in fEkct the combustion of the ooal at the expense of the oxygen of lithaige, the
weight of metal produced indicating the amount of oxygen expended, whence the heating
power may be calculated. It is found that 1 pt of pore carbon psodnoes 34*6 of Bks-

25
tallic lead ; hence if a sample of fuel produces 26, the heating power is ■ of that

of carbon, or asHnming that 1 lb. of carbon raises 7900 lbs. of water 1^, I Dk of the
sample of ooal is capable of raising 6724 lbs. of water by 1^.

Various tables hare been gixen by Beithier and other experimanteraiy of resolta ob-
tained in this manner, the fulowing being some of the most useful figures : «-

Goldng Dowlais coal produces

Glamoigan

Newcastle

Wigan cannel

Cherry coal, Derbyshire

Glasgow cannel

Durham

Fennsylyanian anthracite

By a comparison of the result of any experiment with these standard figures^ a
tolerably fair estimate may be made of the specific yalue of any sample.

The method of operating consists simply in mixing a known weight of the finely
powdered fuel with about forty times its weight of pure litharge^ and exposing the
mixture to a gentle heat in a large crucible finally raised to a dear red heat. The pot
is removed, struck on the floor to assist the settling of the metal, and broken when
cold. The button is cleaned and weighed. The accuracy of the result depends greaHj
upon the relative proportion of hydrogen and oxygen : when they are in the yiapoT'
tion necesaaiT to form water, the result is tolerably correct; but it is evident that any
excess of hy w^en over and above this proportion introduces an error, inasmnch as its
heat equivalent is calculated as if it were carbon, while in truth it is about four times
as great The results of the British Admiralty investigation, by De la Beche and
Playfair, exhibit a variation often " amounting even to a virtual contradiction " of the
simultaneous results of direct combustion.

Other experiment^^rs have found difficulty in obtaining constant results by Berthiei's
method, but Mitchell has found that the difficulty may be obviated by sabstitnting
ordinary carbonate of lead for the litliarge.

The best practical method of valuing fuel consists in employing an a^^iaratui
similar to those used by Andrews and other chemists in the determinatioii of the
actual heating power of carbon, hydrogen, &c., or of a miniature ftimaoe to which a
known volume of air is supplied, with arrangements, such as readily suggest them-
solves, for the complete utilisation of the heat evolved. It is to be remembered that
the real value of all such results is simply relative.

The imperfect character of most boiler arrangements and the large quantity of coal
which passes into the ash-pit xmconsumed, together with the irregular supply of drangfat
and the amount of heat absorbed by the great excess of cold aur, result practically in
an enormous loss of heating power, to an extent which, even under the most caieful
management, is widely variable. Thus, the results obtained in the American and
British Admiralty experiments exhibit grave discrepancies. In the case of the latter
investigation, a Uomish boiler only 12 feet long was employed, and "even from the
smallness of the boiler employed, the results fell short by 20 per cent, of the maxinnxm
amount of work which the same fuels could perform when applied to larger boilers ccmi-
structed and set on the same principle The inouiry is rendered less effident from
another cause, vis. the wont of a thorough control and measurement of the air rtmring
through the furnace."

We have referred to the ij\jurious properties of sulphur as an ingredient in coals,
and to its average quantity in various dasses of fuel Its amount may be estimated
by fusing in a large silver capsule a few pieces of caustic potash and | of its weight
of nitrate of potash and a few drops of water. After cooling, the findy powdered
coal is added, and the whole re-fused till white. The mass is dissolved in hydro-
chloric acid, and the sulphuric acid produced is estimated by piedpitation with
chloride of barium. It is always necessary at the same time to estimate the quantity
of sulphuric acid present in the ash of the coal, and to deduct this from the amount
obtained as above, in order to obtain the quanti^ due to the oxidation of the sulphur
only.

COAL-GAS.

1035

Deflagration "with 2 pta. nitre and 10 of chloride of sodium may also be employed,
but the greatest care is necessary to control the action.

The importance, in addition to a knowledge of the chemical character of a fuel, of a
consideration of its mechanical condition, is amply exhibited by the fact acknowledged
in both the government series of experiments, that it was a sine qvd non that the
toughness of coals must be such, for naval use, as to resist, without crumbling, the
constant friction in the ship's hold, at the same time that its fracture must be such
that it packs into the smallest possible space. In this respect, coals of equal heating
power vary 20 per cent, at least " This factor, which is of extreme importance in steam-
navigation, becomes reduced the more the cleavage of the coal or the shape of the fuel
approaches the form of a cube. In order to attain, at least, a relative idea of the
waste occasioned by transport, i. e. of the attrition of the individual pieces of coal
against each other, and conversion of unbroken coal into dust unfit for use, which is
occasioned by the motion of the vessel, the various specimens were rotated in a drum
for the same length of time, and the dust thus produced separated and weighed."

The subjoined table shows some of the results of the British investigation as regards :

1. Number of lbs. of water at 100° C. converted into steam by 1 lb. of fueL

2. Ditto, after deducting portions of coke contained in the ash.

3. Theoretical evaporative power in lbs. of water of 100° G. evaporated by lib. of

fuel calculated from litharge test.

4. "Weight of coal per cubic foot of stowage in lbs.

6, Ditto, per solid cubic foot» deduced from specific gravity.
6. Percentage loss by equal amount of attrition.

KlDdofFu*!.

Wblbh:—

Jones and Co*s Anthracite ....

Ward's Fiery Vein

Graigola

Duffryn •.•....

Ponty Pool

Bbbw Vale

Bedvai

Scotch:—

Dalkeith Jewel

Walltend Elgin

Fordel Splint

Grangemouth

Bmglub:—

Broombill

Park End, Sydney

Uua:—
Slleverdagh .......

Mean of three patent ftiels . . • .

9-46
9-40
9-85

10-14
7-47

10-21
9^9

7-08
8-46
7-66
7-40

7'K)
8-52

9-66
9^

970
10-rjO

9*86
11*80

8*04
10-64

9-99

7-10
8-67
7-69
7-91

7*66
8-98

10-49
9-66

13-84
16-40
16-72
16-64
14-31
16-68
14-70

13*77
16-16
16*12
14-86

13*90

16*21
15-44

68-36
67*43
6017
63-22
65*70
58-30
60-60

49-80
64*60
6500
64-26

62*60
64-44

62*60
66*48

85-79
83-6^
81*11
82-72
82-36
78-81
82*60

79-67
7861
78*61
80-48

77-99
80*06

99*67
70-66

68-6
46-6
493
66-2
67-6
46-0
64-0

85-7
64-0
63*0
69-7

66-7
66 0

74*0

For further information on coal, see Ur^s Dictionary of Arts, Manufactures and
Nines, L 696 ; also Bonalds and Sichardson*s Chemieal Technology, 2nd ed. i [1] 28 ;
i [2] 761 ; Percifs MetaUurgy, I 78—106. W. W.

COHTiFiClilBi The gas produced by the destmctlTe distillation of pit-coal at regu-
lated temperatures.

The apparatus used in the manufacture of coal-gas on the great scale consists essen-
tially of a system of closed retorts of flreday or cast-iron, ue exit pipes from which
communicate with a hydraulic main, in which the crude gas deposits part of its tar
and ammoniaeal products. It passes thence into a series of condensing pipes, wherein
it is exposed to the action of a large refrigerating surface, and deposits the greater
part of its tar and ammonia-liquor, the last portions being remoTcd in its passage
through another s^es of yessels of yarious forms and m<^ifications, in which tEe
gas is sorubbed, by being obliged to force its wa^ through breese, stones, or other mate-
rials which serve to comminute it and bring it mto thorough contact with a stream of
water which continually percolates the TesseL It is then deprired of its carbonic acid
and sulphuretted hydrogen in lime purifiers, and finally is drawn by exhausting appa-
ratus into the gas-hol^srs, passing on its way through the station-meter and other
beautiful and delicate apparatus, whereby the pressure and amount of gas which
passes into the town are regulated and registered. (See the article Coal-Gas in Unfs
JHctionary of Arts, Manufactures and Mines.)

1036

COAL-GAS.

The £>]lowiiig analjBU by Bniuen and Bosooe eziiibits the ooBlpoaition of
Chester coal-gae preparcd from Cannel coal :

^drogen 45-58

^^arsh-^ 94*90

Carboxuc oxide 6*64

Olefiant gae or ethylene 4*08

Tetrylene 2*38

Sulphuretted hydrogen 0*29

Nitrogen 2*46

Carbmiic add ......... 8-67

100-00

In addition to these oonatitaents, there are frequently present traooB of tanmoma.
Vapour of sulphide of carbon, cyanogen, and oxygen.

The composition aboTe given, represents that of a first-rate sample of gas ; bvt the
relatiye proportion of the several ingredients depends both upon the quality of coal
used, upon the temperature of the retorts, and the time during which the diatillmtian
is continued. It is to the olefiant gas and other heavy hydrwarbons present in oom-
paratively small quantities^ that the illuminating power of gas is chiefi^ doe ; the
maintenance of a full proportion of this gas is therefore of the utmost importaaoe.
The following table shows the quality of gas from 1120 lbs. of common coal at the
Clifton gas-wo^s, Manchester, at different periods of distillation :

Honrt fron con*
meaeemwal.

100 BBflMorM purified gai contain

100 meeium of parifled
gatooonnne

Oxygen.

Oleflsnt gai.

Nitrogen.

Other Inferior gut*.

1
3
5
7
9
11

10
9
6
5
2
0

0
0
0

15
9

90
91
94
80
89
85

164
168
132
120
112
90

Hence, two things should especially be avoided in the maaufiicture of gas,
too low a heat and a too long continuation of the distillatory process. The eSeiet of
too low a heat is a great diminution of the gaseous products, tilie chief result of the
distillation being the production of tar. The efiect of continuing the distillation too
long, is that gases of very feeble illuminating power are evolved, together with nitrogen,
which, when once mingled with the combustible gas, cannot be removed by any knovn
method, and must seriously impair its illuminating power.

The following table by Hughes gives an idea of the relative and absoluto yield of
different kinds of coal under practical management :

Name of CoaL

Newcastle, average of 3 samp.
Wigan cannel

Scotoh Parrot

Lesmahago cannel

Boghead cannel .

Inoe Hall cannel

Derbyshire .

„ soft, aver, of 3 samp

Neath, South Wales

Westbromwich, parliament-
ary return of ISirmingham
gas company .

Staffbrdahire, iiTen^e of 4
samples . • . .

Cubic feet of
Gai per ton.

11,492

11,336

9,500

9,408

9,500

11,312

15,000

11,400

9,400

7,166

11,200

6,500
10,467

Specific Gra<
vlty of Gae.

*452
-416
•490
•478
•640
•737
•752
•528
•424
•466
•468

•453
•376

Weight of Gat in tba.
per too of Coal.

398 Hedley.

362 Glegg.

857 We.

344 Wright

638 Hedley.

866 Evans.

461

308 Wright

256 ParUamentary return.

401 Hedley

226

302 Clegg.

COAL-GAS. 1037

Modes of estimatifig Lufmn{feroU9 Value.

The gas manufacturer relies much as an indication of the puzitj of his gas, upon its
specific grayity, which he commonly takes approximately by means of a balloon, con-
taining when foil 1000 cubic inches, and gauged by a ring which fits its largest diameter
when falL Attached to the balloon is a car, into which as many grains are put as balance
the balloon. This result^ although not scientifically accurate, pptves, after correction for
temperature, barometer, &a, an indication of sufficient practical value, but of course
vitiated by the presence of any large amount of carbonic acid.

The comparison of gases by the photometer is a test preferred by many gas-engineers
to all others. It consists of the comparison either of shadows, or of transmitted light
passing through a semi-transparent disc of paper with reflected light striking on an
opaque portion, in juxtaposition to the transparent portion. When the light is so ad-
justed that the shadows are precisely similar, or that the liffht reflected and that
transmitted by the disc are equal, then the lights are to each otner in the ratio of the
squares of their distance from the disc or screen.

The only chemical test upon which the practical gas maker commonly relies, is the
amount of absorption which takes place upon introducing into a known volume of gas
a bubble of chlorine or a drop of bromine, the prindpid hydrocarbons to which gas
owes its luminiferous value being condensed by these reagents into oily compounds.
These methods are, however, of the roughest kind.

An accurate result may, however, be obtained by substituting for chlorine or bromine
a fragment of coke saturated with Nordhausen sulphuric acid, the experiment being
made over mercury and the absorption beiu^ allowed to ^ on for two or three hours.
Subsequently the sulphurous acid produced in this action is removed by a ball of bin-
oxide of manganese^ and finally aqueous vapour is removed 1^ a ball of caustic potash.
The quantity of carbonic acid being also determined, the difference between tne two
experiments gives the amount of luminiferous hydrociEurbons accurately. The value of
these, being in proportion to the carbon they contain, is ascertained by exploding
portions of gas before and after removal of the hydrocarbons with excess of oxygen, and
comparison of the amount of carbonic add produced in each case respectively. The
difference is the amount due to the carbon of the luminiferous constituents. (For
details of the mode of analysis of such a mixture, we refer to Miiler'a Chemistry^ ii.
661, to Regnaulf$ Coura JSUmentaire, iv. 73, to CUg^a TreatUe on Coal-gcu^ and
more particularly, for the most recent and accurate methods of operation, to BunsetCs
Gtuometry^ p. 107, to the article Aitajltsis (Voltticbtbio) of Gasbs, in this Dictionary,
and to the article Coal-oas in the new edition of Ur^a Dictionary of Arts, Manvfao-
tures and Mines^

The Bev. W. B. Bowditch proposes to determine the relative illuminating power of
coal-gas, in other words, the pro^rtion of ethylene, propylene, and other heavy hydro-
carbons contained in it, by the intensity of the red colour which they impart to woody
fibre moistened with sulphuric acid. When rich coal-sas, giving the light of 20 to 25
sperm candles from consumption of 5 ft. per hour, is sfowly passed through clean dead
sawdust, well moistened wiu pure sulphuric add diluted with five or six volumes of
water, so that it may not blacken the sawdust^ that substance instantly acquires a
beautiful pink colour, which eradually deepens to a dark mahogany ; with a |)oor
gas, which ^ves the light of on^ ten or twelve candles at the same rate of consumption,
the coloration is faint at first and deepens very slowly. The differences of coloration
are so considerable and constant that they may perhaps be used as a means of deter-
mining the illuminating value of the gas. By using a standard add, the same kind
of sawdust, a uniform volume of gas, and the same sized U-tubes, notation of time and
depth of colour would give a dose approximation to the light-giving value. (Proc
Boy. Soc. xi 25.)

Li addition to the constituents estimated by these operations, it is frequently im-
portant to determine sulphuretted hydrogen and bisulphide of carbon. Their presence
IS well detected bv the simple and useful apparatus of Wright, consisting of an ar-
rangement for condensing the products of combustion from a gas-jet^ and testing the
condensed liquid for sulphuric acid.

Their amount may be determined by passing a known volume of gas through, 1st, a
solution of caustic potash in water, and, 2nd, a solution of the same reagent in alcohol.
The former absorbs sulphuretted hydrogen ; the latter the sulphide of carbon, which
it converts into xanthate of potasdum, which is in turn decompoised by boiling. Dilute
solution of nitrate or acetate of lead being added, sulphide of lead is predpitated, and
its amount is judged of by comparison of the shade of colour produced in the liquid
with a solution containing a known quantity of lead predpitated in the like form.

Another method of detecting sulphide of carbon in coal-gas, is to pass it through an
ethereal solution of triethyl^hosphiw^ which forms with sulphide of carbon a compound

ing s CBirent of coul-giu tfarongh a solution of four or fire dron of triethjlphosphine
ID ctliec iwDtamcd in a hulb- apparatus, a, distitict red mloratioa iru pnidoced lArr
0-2 of a irubii; foot of gas had passed through the liquid; uid after O'S of a cahic foot
had passed, the whole of the ether had evaporated, and the inner mrikee of the bull"
apparatus was lined with a beantithl net-»ork of tie raby crystals.

IjibIIj, ^e sulphide of carbon may he easily detected by a method which lilewis*
lervBB for ita removaL For Ihig method we are indebted to the Ser, W. K. Bow.
ditch (/oc. eii.) It conswts in decomposing the Eulphide of carbon with hydmj'a.
thereby conrerting it into mJphide of bydiogeo, wbieh ia eaaily detected and remoied
by the usual methods. When a mixture of hydrogen and Tapour of sulphide of carbon
is passed through a tube filled with slated Kme or clay, which has been dried betwrea
400° and fiOO" Fahr.. and ia kept between 400° and 800° durinc the passage of the
gaseous mixture, the sulphide of carbon is completely deeompoe^ the lime or rlsy is
blackened by a deposit oif carbon, and sulphur sublimes in the exit-tube, while snlphide
of hydrogen pusses through, and may be detected by acetate of lead. Tbe same effirt
is produced when coal-gas containing sulphide of carbon ia passed oTer heated limew
clay, the tiee hydrogen in the gss then decomposing the sulphide of carbon in the
manner just described. This method may be applied on the large scale to the puri-
flcation of coal-gas from sulphide of carbon, the snlphoretted hydrogen resulting frtm
the decomposition being afterwards remored by slaked lime in the ordinary way.
Paasing the gas over clay likewise decomposes other volatile sulphnr-componnds wbich
are not removed by the ordinary mode of purtflcation with lime. These a>mpo(indi,
including sulphide of carbon, have long been regarded ai the most troublesome im-
purities of coal-gas. The sulphur which is evolTOd from the coal as sulphuretted hy-
drogen, ia easily removed by slaked lime ; indeed, the London coal-gas rarely, if ever.
exhibits the sUghteet trace of this compound. Bnt it always coutsins Enlphide of
earlMU or some of the other volatile sniphuiH»mpaanda just mentioned, the proportion
of sulphur contained in it varying, according to Hofinann (foe. cil.), from 6'68 to 10'S3
Bruins in 100 cubic feet Now the sulphur in tiuming produces sulphnrone aeid, which,
besides being otTcnsive to the senses, is vcrj destmcliTe to art-dc«)ration», bindings of
books, &C. The removal of these snlphur-componnds will, therefore, do awsy with
the greatest existing objection to the use of gas in dwelling housee.

The use of clay as a purifier of coal-gas is likewise attended with other adv«nlaj>i«,
as it absorbs ammonia and other nitrogen-compounds which diminish the light-girini;
power of the gas. This ofTcct is especially conspicnona when the gas given off to-
wards the end of the distillation (p. 30), is submitted (o the action of the clay.

Clay which has become charged with the impurities from coal-gas, may afterwards
be naed as a maDurs.

Secondary PreJucll otloined m lie tnanufiKlun of Ckxd-gtu.

After a charge of coal has been worked off to the extent considered most desirable,
the man-lids are removed from the retorts, and the residual coke raked out iDti> barrows,
wheeled away and quenched with a jet of wafer. Ifs appearance and uses, aa fne! tut
locomotives, in the blast furnace, and in a vait number of technical operationa, are tuo
well known to need description, nor does space allow us to gu Into details of rhe
numerous processes which have been employed, with more or less success, fnr the
economical preparation and purification of coke.

The liqnids condensed during the passage of Ihe gas through the hydrsnlie mains
and condensers, are of a very complex character. They consist essenti^y of two
portions, the onewateirand the other tarry, crude coal-tar varying in density between
1120 and llEO, the lightest portions containing the largest proportion of liquid oils.

The basic substances contained in coal-tar include ammonia, aniliD^ picotine,
chinoline, pyridine, toluidine, and othera of Ices importanca.

The acids inchide acetic in minute quantities, rosotic, bronolic, to, but prindpally
phcnic or carbolic acid. The neutral portions contain benzene, toluene, cumene, cymeno
(liquids) ; naphthalene. paranaphthsJene or anthracene, chrvsene, and pjrene (soliili).

The commercial dietillaf ion of coal-tar is performed in large retorla, holding from
20O to 600 gallons. The first products are gaseous ; next passes water chafed -wiXh
ainmoniacal salts, and contaminated with black oily matter.

The proportion of oil continues to increase, while that of watery products diminishes.
Finally, aflorfrom 6 to 10 pec cent, of the whole has passed in the form of " light oil."
the product becomes heavier than wafer, and is collected apart aa "kreasote oil," or
dead oil," used extensively for the pickling or antiseptic preparation of timber, and
for burning into lamp-hlack. Naphthalene and other solid products now become abun-
dant and (he oil becomes paaty. Finally, tho residue in the retort ia nm off while hot.

COBALT. 1039

and on cooling becomes hard and brittle, constitating asphalt, a product nsed in the
manufacture of coarse Tarnishes, and on a vaetlj larger scale in laying down railway
and other bridges, as a means of protecting their masonry firom the infiltration of water.

The heary oil contains a variety of hydrocarbons of high boiling pointy together
with carbolic acid, to which latter it probably owes its antiseptic qualities.

Theliffht oils obtained in the aboTe piooess are rectified, whereby a further portion of
heavy ous is separated and crude naphtha obtained. This is agitated with sulphuric
acid, and the supernatant liquid, upon carefbl rectification, yields the " highly rectified
naphtha" or "benzole" of commerce, consisting of a complex mixture of at least
five oils boilinff at from 149° to Z97P F., and of specific grarity -860 to '890.

The watery liquids deposited in the condenser during the manufacture of gas, are
devoted to the production of sulphate and chloride of ammonium. They are usually
removed from the gas-works in flats or canal boats of known capacity, under contracts
commonly taken at so much per 10,000 gallons.

The manufacture of chloride of ammonium direct from the liquors, is conducted on
a large scale in Liverpool, and consists essentially in saturating with hydrochlorio
add, concentrating the liquors, crystallising and subsequently subliming the crystaLs.
A far larger portion, however, of the crude gas-liquor is consumed in the manufacture
of sulphate of ammoniimi, by processes which consist essentially of distillation, with
addition of lime, to decompose ammoniacal salts, and condensation of the vapour in
sulphuric acid, concentration and dystallisation of the solution after saturation has
been efibcted. Sulphate of ammonium is employed in lajrge quantities in the mauu-
facture of artificial manures.

The above are the chief products of distillation of coal at high temperatures, while
those at regulated low temperatures are finr difierent. Under the latter conditions,
the gaseous products are reduced to their minimum, while the quantity of liquid and
solid hydrocarbons is proportionately increased.

The Boghead C^umel of Batheate, near Edinburgh, is extensively submitted to the
process of slow destructive distillation, under the patent of Young, while successful
efforts have lately been made by Mr. Blackwell, of Dudley, to turn to account the vast
heaps of somewhat bituminiferous shales or " batts " ejected from the coal mines of
Staffordshire.

To this subject we cannot farther refer than to remark that for practical purposes
the products may be separated into tiiree portions.

1. Remains liquid at all ordinary temperatures and forms, after proper purification,
a valuable burning oil, known as " photogen." — 2. Deposits crystals of solid hydro-
carbons at very low temperatures ; used extensively ror lubricating machinery and
known as '* paraffin oil." — 3. Solid or semi-solid products, which when freed from the
oik which contaminate them by pressure, &c. consist chiefly of paraffin (q, v,) and may
be employed alone or mixed with tallow, stearin, &c. in the manufacture of candles.

W.W.

OOBAIUT. Kobalt, Cohaltum.—Sffmbol, Go. AUmie Weight, 29-5.— The use of
cobalt for imparting a blue colour to glass, appears to have been known to the Greeks
and Romans, though most of their blue glasses were coloured with copper. Some of
the pigments used oy the ancient Greeks likewise contained cobalt. The use of cobalt
for the preparation of smalt was introduced about the middle of the sixteenth century.
The metal, in an impure state, was flrst extracted by Brandt in 1733.

Cobalt is not a very abundant metal It occurs as an arsenide, called tin-white cobalt
or 9maltine; as sulpharsenate, or cobalt-glance; as arsenate, or cobalt-bloom; as sul-
phate and as black earthy cobalt^ which is a compound of protoxide of cobalt with per-
oxide of manganese. It also occurs in small quantity in other minerals — as in selenide
of lead, cerite, and Flemish ooaL In the metallic state, it occurs only in meteorites^
many of which contain from 0*1 to 1 per cent, of it, associated with iron and nickeL

Preparation, — Cobalt is extracted chiefly from smaltine and cobalt-glance, or from
the impure arsenate obtained by roasting these ores. The roasting has the effect of
driving off a considerable portion of the arsenic, which escapes as arsenious oxide, and
is condensed in the manner described under Assmno (i. 365). The roasted product
consists essentially of basic arsenite, arsenate and sulphate of cobalt, together with
iron, nickel, and in smaller quantity bismuth, tin, copper, and manganese. When
prepared on the large scale, it is mixed with twice its weight of siliceous sand, and
sent into the market under the name of taffre^ which is used for giving a blue colour
to glass, enamels, and pottery glaze.

The preparation of a pure oxide of cobalt from the native minerals or the roasted
ore, is effected by one of the following processes :

1. Cobalt or smaltine is dissolved in nitric acid, or in dilute sulphuric or hydro-
chloric acid, to which a little nitric acid is added, — or the roasted ore or earthj
cobalt is dissolved in sulphuric or hydrochloric acid alone ; the filtered solution is

1040 COBALT.

evaporated nearly to dzynefle, a large quantity of arsenions acid then aepazating out ;
and the L'qnid is largely dilated, separated £rom the arsenions acid, and treated with
Bulphnretted hydrogen as long as the sulphides of arsenic^ copper, and bismnth (to-
gether viUi tin) continue to be precipitatecL The solution is thea filtoed, and heat«d
till the excess of sulphuretted nydrogen is expelled and the protoxide of iron con-
verted into sesquioxide ; carbonate of sodium is then added in excess, while the liquor
is hott to precipitate the nickel and cobalt in the form of carbonates, and the iron as
sesquioxide. The precipitate is then wdl washed and digested with excess of aqueous
oxidic acid ; the s<uuble ferric oxalate is separated by filtration from the oxalates of
nickel and cobalt, which are insoluble even in excess of oxalic acid; and the latter
salts are triturated with dilute ammonia (it should be strong ammonia according to
Stromeyer) and dissolved in excess of the ammonia^ by agitation and gentle heating
in a dose vessel. The filtezed solution, after exposure to the air for several days,
deposits the oxide of nickel in combination with oxalic add and a small quantity of
ammonia, while pure oxalate of cobalt remains in solution. (The oxalate of nickel
separated as above may be freed from the small quantity of cobalt-salt which Mia
down with it^ by washing with water, re-dissolving in ammonia, exposing the liquid
to the air, and separating the solution which contains the cobalt from the nidcel pre-
cipitate, the purity of wMdi increases at each repetition of the process.) The residue
obtained by evaporating the ammoniacal solution of the oxalat^ yields sesquioxide of
cobalt when igmted in the air, and metallic cobalt if ignited out of contact of air.
(Laugier.)

2. To avoid the tedious passing of sulphuretted hydrogen through the liquid, the
arsenic acid may be precipitated by first mixing the dilute solution with a feizic salt,
and then adding carbonate of potassium in smau successive portions and with constant
agitation, as Ions as the precipitate continues to exhibit a white or brownish colour
(arsenate of feme oxide) ; tilC in short, a filtered sample of the liquid gives a reddish
precipitate with a small quantity of carbonate of potassium. If fhe quanti^ of ferric
oxide be suffident, and the proportion of carbonate of potassium rightly ac^usted, the
whole of the arsenic add and ferric oxide may be predpitated. ^ If the copper and
bismuth be then removed by sulphuretted hydrogen, it only remains to separate the
nickel from the cobalt (Berthier.)

3. Finely powdered cobalt-ore is careMly roasted, and 1 pt of it added in suc-
cessive small portions to 3 pts. of acid sulphate of potassium heated to the melting
point in an earthen or cast-iron crucible. The mass, which is thereby rendered pasty,
IS then more strongly heated till it fiises quietly and no longer gives off fumes of
sulphuric acid, as it is neceesazj to drive away the excess of that add. The mssa,
while yet liquid, is then taken out of the crudble with an iron spoon — broken to
pieces after cooling — dissolved in boiling water, and filtered from the arsenates of
iron and cobalt, wtach are not soluble in a neutral liquid. Sulphuretted hydrogen is
then passed through the filtrate to throw down any antimony, bismuth, or copper that
may be present — the liquid again filtered, and pure carbonate of cobalt pred{»tated by
carbonate of potassium. To prevent the formation of arsenate of cobaJt, the roasted
cobalt-ore, before fusion with sulphate of potasdum, may be mixed with a small
quantity of ferrous sulphate, so that the aisenio add may combine with the oxide of
iron contained in that salt in preference to the oxide of cobalt. No nickel is taken
up by the liquid, because the sulphate of nickel is decomposed at a red heat [not so,
however, the sulphate of nickd and potasdum, unless the neat ^plied is very strong].
The solution retains but a trace of iron at the utmost. (Lie big, ^ogg. Ann. xviii, 164.)

4. One part of pulverised smaltiue or cobalt-glance is fused in a covered earthen
crudble with 8 pts. of carbonate of potassium and 3 pts. of sulphur, whereby the
whole of the metals present are converted into sulphides, and sulphide of potassium is
formed, which unites with the sulphide of arsemc, forming a soluble sulpharsenate.
The heat must be so regulated that me sulphide of cobalt may not ftise, but remain in the
form of a ciystalline powder, because, if fusion takes place, portions of the sulpharsenate
of potasdum will be endosed in the fused mass, and will he difficult to wash out. The
mass is then freed from sulpharsenate of potassium by repeated exhaustion with water
and decantation ; again treated with carbonate of potasdum and sulphur, and then with
water to remove the rest of the arsenic; afterward^ dissolved in niteie add or in
dilute sulphuric add mixed with nitric; the solution is treated with sulphuretted
hvdrogen to remove any remaining arsenic, together with bismuth and copper ; and the
filtered liquid is treated as in method b, to separate the cobalt from nickel and iron.
(Wohler, Pogg. Ann. vi 277.)

6. To obtain cobalt from black earthy cobalt ore, the mineral is dissolved in hydro-
chloric add ; the arsenic, antimony, lead, and copper are precipitated by sulphuretted
hydrogen ; the filtrate is boiled with nitric add to promote the further oxidation of
the iron ; the iron is predpitated by boiling with acetate of sodium, and the cobalt
separated from the filtrate by sulphuretted hydrogen, which leaves acetate of manga-

COBALT: ALLOTS. 1041

neBe undecompoied. The precipitate is free from nickel, but contains a trace of zin&
The liquid freed from arsenic and copper hj sulphuretted hydroffen maj^ likewise be
precipitated by sulphide of potassium or barium, and the washed precipitate treated
with cold dilute hydrochloric acid, which dissolyes the sulphides of manganese, sine,
and iron, and leayes all the sulphide of cobalt undissolyed. (Wackenroder, K. Br.
Arch. xn. 188.)

The greatest difficulty in the preparation of pure cobalt-compounds is the separation
of the nickd. Iiaugiers method (yid, n^.), aflbrds the means of obtaining a cobalt so-
lution free from nickel; but it leayes a certiiin portion of the cobalt in the nickel pre-
cipitate. For mare complete modes of separation^ adapted to quantitatiye analysis, see
Cobalt, Dxraanos akd EsTiMAnoK or (p. 40).

JIfetallie Cobalt — Cobalt is reduced fi!om its oxides by ignition with charcoal
more easily than iron, or the difficultly fusible brittle' metals; when thus reduced,
howeycir, it contains carbon. The purest metal is obtained by igniting the oxalate in
a coyered crucible, the salt^ CoKX)\ being then resolyed into 2 at cobalt and 2 at.
carbonic anhydride. If the oxalate or the mixture of oxide and charcoal be coyered
with pounded glass free from reducible metals, and heated in a blast-furnace, the co-
balt is obtained in the form of a fhsed re^us. Cobalt may also be reduced from its
oxides by hydio^ ; and if the heat ap^Ued be not yeiy great the reduced metaJ is
pyrophorie, like iron reduced under similar circumstances,, and takes fire on coming
in contact with the air, producing cobaltoso-cobaltic oxide.

Cobalt rendered compact by fasion is rather hard^ has a granular fracture, and is
somewhat malleable at a red heat The presence of arsenic, manganese, &C., renders
it brittle. It has a steel-grey colour, inclining to led ; in the policed state, howeyer,
rather to white. The statements respecting its speciflc grayity yaiy from 8*518,
(Berselius), to8*7(Lampadiu8). That ofthe metal reduced by hydrogen was found
by Bammelsberg, in fiye experiments, to yary from 8:132 to 9*495; mean 8*957.
Specific heat - 0*10696 (Begnault), 0*1172 (De la Biye and Marcet). It fuses
more easily than iron, less easily than gold. It is attracted by the magnet, and is
capable of receiying a slight magnetic power when rubbed with a magnet^ this power,
according to Poumet, not bei^ destroyed by the s^ngest red heat^ A minuta
quantity of arsenic destroys the magnetic power.

Cobalt is not altered by the action of air and water at ordinaiy temperatures, but
when yery strongly heated, it tskes fire, and is oonyerted into oobaltoso-eobsltic oxide^
C*K)^ it decomposes aqueous yapour at a red heat It is dissolyed by hydradds and
by dilute oxygen adds, with eyolution of hydrogen, slowly howeyer, and only when
heated. The solutions haye a fine red colour^ and contain salts corresponding in com-
position to the protoxide. It is easily dissolyed by nitric add, IDLewise^rming a
proto-salt

Cobalt forms seyeral classes of compounds, the most numerous, and generally speak-
ing the best defined beina; the proto-compounds or cobaltous compounds, e.g. Cod,
Co'O, Co^ Co'SO\ &C. ; there are likewise cobaltic- or sesqui-compounds, e. g, Co^O',
Co^S*; three oxides intermediate between the two preceding; a dioxide, CoK)*, a disul-
phide, Co^, a tricobaltic phosphide, Co*P, and seyeral classes of salts containing bases
in wMch cobalt is united with the elements of ammonia.

COBA&T« AS^tMYU O V. Cobalt unites readily by fusion with antimony and
arsenic, the combination being attended with incanoesoance ; the resulting alloys are
brittle, and haye an iron-grey <»lour.

Proioarsenide of Cobalt, CoAs, is found natiye as smaltine or tin-white
cobalt, being in frict the most abundant of cobalt ores. It occurs in crystals belong-
ing to the regular system, yiz. cubes, octahedrons, dodecahedrons, and intermediate
forms, deayaoe octahedbral, distinct ; cubic, in traces. It occnrs also masdye and in
reticulated and other imitatiye shapes. Specific grayily 6*8 to 6*6. Hardness 6'5.
Lustre metallic Colour tin-white, inclining sometimes to steel-grey, sometimes to
silyer-white. It tsmishes by expoeurew Streak greyiBh-bhick. Brittle. Emits a
smell of arsenic when broken. It yidds no sublimate when heated in a test-tube;
but in a tube open at both ends a sublimate of arsenious add is fbimed. It dissolyes
in nitric add, leayin^ a reddue of arsenious add.

Arsenide of cobalt is neyer found <^uite pure^ the cobalt being always more or less
replaced by nidtd or iron ; those yaneties which contain more nidcel than cobalt are
called Cloanthite (see Nickbl). The following are analyses of smaltinA containing
little or no nickd; a, from lUecheladozf in Hesse, by Stromeyer (Qott gdehrt«
Ansdge, 1817, p* 72); 6, from Tunaberg in Sweden, by Yarrentrapp (Pogg. Ann«
xlyiu.505); c, from Scbneeberg in Saxony, by £. Hofmann {ibid, xxy. 485^; d^
from the same locality, by t. Kobell; e. from Biechdsdoxli^ by Jack el (BammeUber^t
AfinerakhemUf p. 23): —

Vol. I. 8 X

. 74-21

20-81

8-42

016

. 69-46

23*44

4-96

—

. 70-87

18-96

11-71

1-39

. 7108

9-44

18-48

trace

..^

0-88 - 98-98

0-90 « 98-76

001

0-66 - 99-88

100

traee« 99-92

0-04

0-49 - 101-26

1042 COBALT: BBOMIDE-^HLORIDES.

1-79

€ . 66-02 21-21 11-60 190 —

The formula CoAb TCqniree 71 '8 As and 28*2 Co. When the noportion of iron is
considerable, aa in e^ d^ e, the mineral is alao called Safiorite, The oompoeition of e
agrees more nearly with the formula (Co ; Fe^As*. Ckathamite, from Chatham ia
Connecticut, is chiefly an arsenide of nickel and iron containing 1*3 p» eent. cobalt.

Smaltine occurs altered to cobalt-bloom by oxidation.

8e*quiars§nide of Cobalt Co^As*. — ^This compound also occurs natrvo aa
Skntterudite or Modumite (Tsaseralkies, Hartkobaltkies, ffartJkobalt\ at Skat-
temd, near Modum in Norway. It crystallises in the regolar system, exhibiting fiices
of the cube, octahedron, dodecahedron, and trapezohedron. CleaTage cubic, distinct;
dodecahedikl in traces. Also massiye, granular. Specific grarity 6*74^6-84. Hard-
ness M 6. Lustre bright metallic Colour between tin-white and pale gtej, some-
times iridescent A ciystaUised specimen analysed by Wohler (Pogg. AmL xBU.
591), gare 79*2 As, 18*6 Co, 1*8 Fe » 99*0, the fbrmu& requiring 78-2 per oeot As
and 20*8 Co. This mineral heated in a dosed tube yields a sublimate of met*nip
arsenic

When smaltine is ignited in a retort, part of the arsenic is expelled, and there re-
mains a lower arsenide of cobalt, which is non-magnetic, and fuses before the blow-
pipe to a brittle metallic globyle. In cobalt-blue works, ciystaUised alloys of cobalt
and arsenic* are often formed, containing also copper and iron. (Scheerer and
Francis, Pogg. Ann. L 513.)

With X of its weight of gold, cobalt fonns, according to Hatchett, a dark yellow
very brittle compound ; eren ^ pt. of cobalt is sufficient to render ^Id brittle.

The alloy of cobalt with iron is very hard and difficult to pulTense.

With mercury, cobalt forms a silTer-white amalgam, wkich is attracted bj the
magnet.

With platinum, it forms a fWble compound.

When cobalt is f\ised with silver, two layers are formed, the lower consisting of
oobaltiferous silver, the upper of argentiferous cobalt; a small quantity of cobalt
renders silver brittle

With tin, cobalt forms a somewhat ductile alloy of light violet colour.

With zinc, it unites only with great difficulty, also with lead and bismuth, whidi
exhibit with cobalt the same deportment as silver.

OOBAXiTt axoanSB or. CoBr. — Cobalt takes op bromine-Tapoor at a dull
red heat, forming^ a green compound which melts, and at a nigher temperature soflers

J martial decomposition. The compound deliquesces ruddly in the air, forming a red
iquid. The same solution is obtained by heating flndy divided cobalt with fannnine
and water. It turns violet-red on evaporation, and leaves a green mass when evapo-
rated to dryness. By evaporating the solution over oil of vitriol, red crystals of die
hydrated bromide acid are obtained, which soon effloresce in the dry air of the receiver,
but deliquesce when exposed to the air in its ordinary state. (Hammelsberg.)

A solution of the bromide forms, with excess of ammonia, a blue precipitate, whidi
turns green on exposure to the air, and a red solution whidi turns brown in the air,
and then sometimes deposits red quadratic tables, perhaps consisting of a eomponnd
of Co'Br' with bromide of ammonium. (Rammelsberg.)

Bromide of cobalt absorbs ammonia'-ffas, forming ammonio-bromide of cobalt,
3NH'.CoBr, a red powder which graduallv turns brown, and is resolved by water into a
brown solution, ana an insoluble green residue containing bromine. (Bammelsberg.)

OOBA&T, OMLOmxnmm or. The protoehioride, CoCl, is formed, with vivid
incandescence, when pulverulent cobalt is heated in a stream of chlorine-gas ; it then
sublimes in blue crystalline scales. It is also produced in the wet war 1^ dissolviBg
cobalt or the protoxide in hydrochloric acid, nydrogen being evolved in the former
case, or by heating the sesquioxide or cobaltoso-coWtic oxide (C6H>*), with hydro-
diloiic acid, its fbnnation being then attended with evolution of chlorine The sohi-
tion is pink, and yields by evaporation non-deliquescent crystals of the same eoloiir,
consisting of hycbated chloride of cobalt But if the pink solution be mixed with
strong hvdrochlorio or sulphuric acid, it turns blue the more readily as it n more eon-
centrated and more strongly heated. The effect appears to be due to the abstraction
of the crystallisation-water by the strong acid. According to Proust, such a solution
sometimes deposits the blue crystals of the anhydrous chloride. The red eolonr is re-
stored by dilution with water. By evaporating the solution to dryness, or by heating

COBALT: DETECTION AND ESllMATION. 1043

the hydiated crystals, hydrochloric add is efvolyed, and a greenish blue mass is obtained,
consisting of an ozychloride (Berzelius), which is decomposed at a hiffher tempera-
ture, yielding a sublimate of anhydrous chloride, and leaving an oxidised compound.

The sublimed chloride forms soft loose crystalline spangles, unctuous to the toudi,
and of li^rht blue colour. On SEzpoeure to the air, it takes up vater and becomes rose-
red, and IS then easily dissolyed by water, forming a red solution ; bat if not previously
hydrated in this manner, it is rery slowly dissolved by water.

The red solution forms a sympathetic ink. Characters written with it on paper are
colourless and invisible or neariy so ; but when the paper is wanned by holding it near a
fire, the writing becomes visible and appean of a beautiful blue. After a while, as the
salt absorbs moisture, the colour disappears, but may be reproduced by the action of
heat. If the paper be e^osed to too nigh a temperature, toe writing becomes black,
and does not afterwards disappear. The addition of a nickel-salt to the solution gives
a green instead of a blue colour.

Ammonuhchloride of Cobalt, 2NH'.CoCl, obtained by paasinff ammoniA-gas over
the heated chloride, is a bulky powder of a pale reddish-white ocMour. With water it
ibrms a red-brown solution, and leayes a green powder. (H. Boss.)

Sesquiehloride of Cobalt, CoKll', is a very unstable compound, fbrmed by dis-
solving hydrated ocbaltic oxide in cold hydrochloric acid. A brown solution is thus
obtained, which begins to evolve chlorine, and pass into the protochloride, this
effect taking place instantly on heating the Uquid. The sesquiehloride is also formed
in small quantity when chlorine is passed through a solution of the protochloride
mixed with hydrochloric acid, the liquid then nswiTning a darker colour.

COBAXiT, BBTSOTZOV' AVB BSTiaKATZOW OV. 1. SUwpipe Re-
action 8, — All compounds of cobalt fused with borax or phosphorus-salt before the
blowpipe, either in the inner or the outer flame, impart a splendid blue colour to the
bead, affording an extremely delicate test of the presence of the metal. The produc-
tion of the blue colour in both flames distinguishes cobalt from all other metals. If
the substance under examination contains a large (quantity of manganese or iron, as
well as cobalt, the bead formed in the outer flame is violet in the former case, green
in the latter. If the glass be then heated in the reducing flame, the manganese colour
disappears, and that of iron changes to bottle green, the glass then exhibiting either
the pure blue due to cobalt, or the greenish blue of a mixture of cobalt and iron.

Cobalt-salts mixed with carbonate of sodium, are reduced on charcoal to a grey
magnetic powder of metallic cobalt..

2. Reaetiona in Solution. — Solutions of proto-salts of cobalt or co-
balt ous salts have a rose-red colour, excepting when the^ are very concentrated and
contain a free acid, in which case they are blue ; dilution with water changes the blue
colour to red (p. 36). The neutral solutions fiiintly redden litmus. Sulphydrie acid
produces no precipitate in cobalt solutions containing an excess of either of the stronger
adds ; but m a solution of the acetate, or of any cobalt-salt mixed with acetate of

Sotassium it forms a black precipitate of sulphide of cobalt. Alkaline siUphidei throw
own the same precipitate, insoluble in excess of the reagent

Potash or soda forms in oobaltous solutions a blue precipitate of a basic salt, which
is insoluble in excess of the reagent, assumes a green or dirty bluish-grey colour on
exposure to the air, from formation of sesquioxide, but if protected from the air, is con-
verted into the hydrated protoxide of a dingy red colour. This last change takes place
quickly on heating the hquid, even if the air be not excluded. A solution of proto-
chloride of cobalt containmff a little sesquiehloride, yields with potash a preapitats
which does not change to cungy red, even on boiUng, but merely acquires a darker
colour.

Ammonia added in small quantity to a cobaltous solution forms a blue precipitate
consisting of a basic salt, which, by continued digestion with ammonia out of contact
of air, is converted into Qose-red hydrated cobaltous oxide, the change being, however,
much slower than when a fixed alkali is used as the precipitant. In contact with the
air, the precipitate becomes green. If more ammonia be added, it dissolves and forms
a biown]sh-i«d liquid, which, if exposed to the air, absorbs oxygen, becomes red-brown,
and then contains salts of various bases, consisting of the elements of ammonia
united with the higher oxides of cobalt (see Cobalt-Basbs, Aii]COiaAoiAi.\ If the
solution contains but a small quantity of ammoniacal salts, which will be tne case if
the original cobalt solution was neutral, potash produces in it a precipitate of hy-
drated sesquioxide of cobalt ; but if chloride of ammonium be added, or if the original
solution contained an excess of acid which has been neutralised by the ammonia,
potash produces no precipitate.

Neutral carbonate of potassium or sodium, forms a rose-coloured precipitate of h^dro-
carbonate of cobalt^ which, when boiled, gives off carbonic add, and assumes a violet,

8x2

carbonate of polattivm fbmia, in nentnl eobaltoa* solutiQca, i roae-coloond ^reripi-
t«l«, with eTolatiaa of carbonic iifid. the liqoid retaining > rsddish cc^onr -wbiefa it
doe* not lose for ■ ■yerj long tims. Ths predpttate altimately ehangea to ■ mu* of
■mall Tose-coloDTed ciTatalii, coiuiating of a compoond of nenbvl eartwnate ct cobak
vith acid carbonate of potauinm. Froqnentlj, also, there i> fonaed a compact pna-

eate, deatitnte of cr}'itallina Btiiictiii«, and omaiiting of a compoand of nentnJ eai-
oate of cobalt with a xeij small qnautitj of cobaltons hirdnta. — Cm-toHoti aj
am/nuraiam produce* a nd predpitale of carbonate of cobalt, Bolahle Jn excos of Xbt
pradpitaot and in chloride of amraomiim ; theaolutLondocanot torn brawn in cont^
with ths air.

CarbonaU of harivm don not in guieral predpatate oobaltoos aalts at ordisuj
temperatum ; from a solntion of tbe ntlphate, bowever, the greater part of the eobatt
is precipitated after a tut long lime, bo that the remaining Ugoid i> nearij oolonricM.
From a eolutioD of the chlorides "^^ precipitation takes pla«e m Um cold, bat bj in>-

1 J v.:i:__ .1.. _i,_i. .r.k bait is pMfiiutated.

B time, a hinllj reddiih while pnci|ntate, wlock
gradoally increBsea, the whole of the cobalt being uHimatelj thrown down *a '»"l-t-
The precipitate is aoliibla in ammonia, lesB euily in cazbocata of ammoniDm
eoloiii«d ammoniacal aolntian, when expoaed to the air, tiit iloiriy depCHta

Fhiipiiate of todiKm prodacea in nentral cobaltooa aoliitioni, a blue precuiitate of
cobaltooa phosphate. K>lublt witii red colour in exeeoe of the oobalt-aolntioii, dsponlAl
again on boiling, and rediseolving aa the liquid cools.

Cyanide of potaetium produces a red-brown precipilat« comdetelj aolable in exceaa
The solution has a gnm-green colour, changing, after a while, to pale brown, and
yields, with hydrochloric acid, a reddiflh-wiiite precipitate, Kllnfale in potash. Snlphids
" """"n does not precipitate the cobalt from this solution, even after a long time.

Ftrroeyanide ofpotainum prodacee a ^reen precipitate of fdrocyanide of cobalt,
changing after a while to greji iosolnble m hydrochloric acid. FerHegattide at potat-
aium prodacea a reddish-brown predpitale, likewise insolabte in hydrochloric acid.
• Brown peroxide of lead mixed with the solution of a coballoDs aall, piccipitalM
nearly all the cobalt, after some time, in tha fbnu of •eaqnioiide; the leactioa m
accelerated by heaL

The non-predpitalion by solphydiic add in praaence of tna mineral aeida, and tha
reactions with alkalis, — oapedauy the formation of a brownish-red solution with eiceaa
of ammonia, from which aolphids of ammonium throws down a black ptedpatets, — are
together aafflcient to distingniah cobattoos solutions &om all otheia. The bkiwpape
reaction will of course be resorted to aa a conflrmatoiy teat.

Many non-volatile organic substaneea, mch aa tartaric add, prevent the [avcqiitadcB
of cobalt by alkalis, but not by mlphide of aaunoDiam.

Sesqni-salts of cobalt, or cobaltic aalta — tha liquid formed hj paaaiBg
chlorine into a aolotion of a cobaltons salt, or by treating it with chlorate of potassinm
and hydrochloric add, till it asaomea a brown-red colour and amella otrongly at
chlorine, exhibits the following reactions : —

Sulphgdric acid produces no pr«dpitata, but only a milktnMS arising from separatiaB
of sulphur, the solation at the same time acquiring the roas-red ootoor cfaanicleriatie
of cobaltoos solto. Suiphide of ammonium, after aatnration of the free acid tiy am-
monium, produces a black precipitate of solphide of cobalt. PoUui, a dark black-
brown precipitate of hydnted cobaltio oxide. Aniinoma, a browniah-red solatku,
which doea not change hj contact with the air. Carionata of potauiuM and todium:
green aolntion which deposits a small qoactity of Bsaqnioxid& Fermofanide ofpotoM-
tium, a green ; and ftrrieyaiude of potatiium, a teowni^-red predpitale. Cbsiw
odd slowly prodacea a precipitate of cobaltons oxalate.

3. Quantitativt utimalion. — Cobalt is gsneralty predpitated from its solutiooa
by tatiitie voUuh, The basic salt at first thrown down ia conTcrted into hydrate

alkali, whici

boiling in the liquid, and than well washed with hot water to free it from

adheres very otMCinately to it. It is then dried and ignited in an atmo-
spnera of hydrogen, by which it is reduced to the metallic state. Ths redaction ia
moat easily performed by placing the dried predpitale in a platinum or porcelain
cmcible, throogh the lid of which paeeea a tube connected with a hydrogen ajqiarataa.
The cmdble mnst be heated to foil redness over a lamp ; if a lower de^ee of bent be
appUed, the reduced cobalt will be pyrophorie, and is anre to oxidise partially during
weighing. The stream of hydrogen must be kept up till the cndble is qnile cold.

As the predpilate thrown down by polaah almost always retains a small quantity of
alkali, eren aftw prolonged wuhing, uie reduced metal mus^ after weighing, be woU

COBALT : ESTIMATION. 1045

Waslied with vnier, tfll the liquid which rana away no longer exhibits any alkaline
reaction. The metal ia then to be dried, again ignited in hydrogen gas, and weighed.
The di£Perence between the two weighings seldom exceeds 0*2 per cent If the cobalt
has been precipitated from a solution <^ the sulphate^ the precipitate may retain a
small quantity of snlphnrie acid : in that case, the reduced metal will contain sulphur,
but nerer more thim a mere trace, unless the precipitate has been boiled with the
liquid fbr a yery long tune.
Alluiline carbonates do not |n«cipitate cobalt so completely as the caustic alkalis.
If the cobalt-solution contains ammoniacal salts, uie precipitation is not complete
eren when a caustic alkali is used, and the liquid well boiled. In that case it is
necessary to precipitate by sulpkids o/ammomum^ wash the precipitate, dry it on the
filter, bum the filter to ashes, then dissolye the sulphide in nitric or nitromuriatio acid,
and precipitate with potash as abore.

If the solution contains none but easily volatile adds, such as nitric or hydrochloric
acid, and no fixed base but cobalt^ the precipitation may be dispensed with altogether,
the liquid being merely evaporated to dryness in the crucible, and the residue ignited
in an atmosphere of hydrogen, in the manner already described.

Lastly, cobalt may be completely precipitated from its neuUfal solutions hy nitrite of
potttssitim, in the form of potassio-cobaltic nitrite, or cobalt-yellow (p. 52). The solu-
tion is eyaporated to a small bulk, and neutralised by potash if it contains excess of
add. A solution of nitrite of potassium is then added, together with suffident acetic
add to neutralise any free potash in the nitrite : the whole is left at rest for two
days, and the yeUow compound which has sei>arated is collected on a filter. The
filtered liquid niould also be treated with nitrite of potassium and acetic add, and
left at rest for some time, in order to see whether any further predpitate forms. The
predpitate is washed with solution of chloride or sulphate of potassium, then dissolved
in hydrochloric add, the liquid being heated till it is quite free from nitrous add,
and exhibits the rose-red colour of a eobaltous salt, and the cobalt is finally pred-
pitated by potash. This mode of predpitation serves to separate cobalt from mckel,
line, manganese^ and many other metals. (A. Stromey er, Ann. Ch. Pharm. xcvi 218.)
4. Separation from other elements. — The metals of the first group (L 217),
are separated from cobalt by predpitatins them with euipkydrie acid, from solutions
addulated with one of the stronger mineral adds. From the metals of the third group
and from the non-metallic elements, cobalt is separated by predpitating it as a
i sulphide with sulphide of ammonium from neutral or alkaline solutions. In applying

I this method to the separation of cobalt from magnedum, it is necessary to add diloride

I of ammonium to retain the magnesia in solution, and even then the sulphide of cobalt

1 sometimes cames down with it a small quantity of magnesia. This may, however, be

prevented by boiling the whole till the free ammonia present is volatilised, then
I adding a few drops of sulphide of ammoniimi, and filtering.

Aluminium is best separated from cobalt by predpitetion as insoluble diacetate
(i. 13). The solution, if add, is neutralised with carbonate of sodium, acetate of
sodium is added, and the liquid boiled for some time. The alumina is then predpi-
' tated in a form in which it may be easily filtered and washed. The washing must be

performed with a warm weak solution or acetate of sodium, as the predpitate is slowly
dissolved by pure water. The whole of the cobalt remains in solution, and the
alumina, which may contain soda, is dissolved by hydrochloric acid, and precipitated
by sulphide of ammonium (L 155). (H. Rose.)

Aluminium cannot be separated from cobalt by solution of potash, the predpitated
oxide of cobalt always carrying some of the alumina with it. A better method is to
frise the mixture of the two bases with solid potash in a silver crudble, and extract
the fused mass with water. The oxide of cobalt which then remains may contain a
little potash, but it is free firom alumioa.

Another vexy good mode of separation is to mix the solution of the two bases with
tartaric add and excess of ammonia, — which will not then predpitate either of them,—
and add sulphide of ammonium, which will throw down the cobalt and leave the
aluminium in solution. The predpitated sulphide of cobalt is then to be treated
with nitric add, See,, as already explained; the filtrate containing the alumina
evaporated to drynees, and the rendue ignited to bum away the ori^ic matter. If
no other base is present, the ignited reddue will consist of pure alumina, which may be
weighed ; in the contrary case, the residue must be dissolved in hydrochloric acid,
and the alumina predpitated by one of the methods given on page 155, vol. i. As the
burning away of the oxganic matter takes a long time, it is perhaps better to destroy
it by boiling the liquid with chlorate of potasdum and hydrocnloric add, and then
predpitate tiie alumina.

Cobalt may also be separated from aluminium by predpitation with nitrite of
potassium.

1046 COBALT : ESTIMATION.

From glueiniim, cobalt may be sepuated by either of the two methoda last-i-

tioned; also from yttrium, lirconinm, thorium, cerium, lanthanum and
didymium. The laat three metala may alao be separated £rom cobalt by preeipit*-
tion with nUphtUe of potassium (L 833), ^ ^^ oxalic add from a solntion ^■nmt^^iwrag
excess of ammonia.

From iron, cobalt is most easily separated by predpitatuig the two metab with
nUvhide of ammomtim, and digesting the washed precipitate in dilute faydiodikirie
add, whidb dissolves the iron and leaves the cobslt As, however, veiy sdaII qvantities
of sulphide of cobalt may likewise be dissolved, it is best to rmeeipitate the iron by
sulphide of ammonium, and teeat the i«ecipitate with very dilute nydroefalone acid : any
slight traces of cobalt that may lie mixed with the iron will then be left undiseotved.

Oobalt mav also be separated from iron (in the state of sea^uioxide) in the aaae
manner as alumininm, viz. by boiling the neutralised solution with oeetaU qfsodiMmk.
The iron is then precipitated, while the cobalt remains in solution. The iron preci-
pitate is washed with warm dilute acetate of sodium, dissolved in hydiDcfaloric acid,
and the iron repredpitated by ammonia; and the cobalt is precipitated by sulphide of
ammonium. If the iron in the original solution is in the state of protoxide, it most
first be converted into sesquioxide by heating with nitiie add. This meUiod yields very
exact results.

A third method of separating iron (as sesquioxide) from cobalt, is to mix the solu-
tion, if neutral, with a considerable quantity of chloride of ammonium, then cantioiish'
add ammonia till a permanent predpitate of ferric oxide just begins to form, and preci-
pitate the rest of the iron with succinate of annmomum. The cobalt remains in solu-
tion, and the ferric succinate, after beins washed and dried, is ignited with good aecea^
of air, to prevent reduction of iron by the organic matter (see Ikon). This method is
not, however, so- good as the two preceding, as the oxide of iron, when ^frumia^i^ \iy
the blowpipe, always exhibits the presence of a small quantity of cobalt

liastly, oobalt may be separated from iron by predpitation with nUrits oj

From mi
separated
of manganesewith dilute hydrochloric add, .

Another method, proposed by Liebig, is to predpitate the two metals as cjaaideB
with cyanide of patassivan^ then add a sufficient excess of that reagent to lodissoiTB
the cyanide of cobalt and part of the cyanide of manganese. The latter is eoUerted
on a filter and washed ; the filtered liquid is heated, and hydrochloric add is slowly
added by dropa, care being taken not to add enough to render the liquid add ; and
the separation of the cobalt and manganese is effected exactly in the manner which
will be presently described for the separation of cobalt and nickel The cyanide of
man(|aneee previously separated by filtration is dissolved in hydrochloric acid ; the
solution is boiled till the hydrocyanic add is completely volatilised, the manganese is

Sredpitated by carbonate of sodium, and the quantity thus obtained is added to that
etennined the other way.

If the cobalt and manganese exist in solution as chlorides, the liquid may be evapo-
rated to drvness (being transferred to a porcelain cmdble wb^ nduced to a small
bulk), and the reddual chlorides ignited in an atmosphere of hydrogen in the manner
described at page 37, as long as vapours of hydrochloric add continue to escape. The
oobalt is then roduoed to the metallic state, while the chloride of manganese remains
undecomposed, and may be dissolved out by water. The metallie cobalt which ra-
mains is washed with hot water, then digested with a small quantity of very dilute
acetic acid, to dissolve out any small quantity of chloride of manganese that nay
remain, afterwards ignited in a currmt of hydrogen, and weighed. The manganese is
precipitated from the solution of its chloride by carbonate of sodium. If the tempera-
ture be raised too high during the reduction by hydrogen, a small quantity of ehloxids
of manffanese may hk volatil^ed.

Anouer mode of separating cobalt from manganese, is to digest the mixed protoxides
(predpitated by an alkali) in a solution of peniasulpkide ofcdlcium, whidi converts
them both into sulphides, dissolving the sulphide of cobalt^ and leaving the solphide
of manganese undissolved.

From nickel, as from most other metals of the second group, cobalt is most eaflfly
separated by predpitatioii with nitrite of potassitimi the process being peribnned
exactiy as described at page 39. With due attention to the precautions there indi-
cated, the whole of the cobalt is predpitated, without a trace of niekd

Another method is that of H. Kose, depending on the frust that protoxide of oobalt
in solution is converted by chlorine into sesquioxide, whereas with nickel this change
does not take place. The^ metals or their oxides being dissolved in excess of hydro-
chloric add, the solution is diluted witii a huge quantity of water, about a pound of

COBALT : ESTIMATION. 1047

water to a getmm^ of the metals or their oxides. Ghlorino gas is then passed thiongh
the solution for several hoars, till, in fact, the space abore the liquid becomes per-
manently filled with the gas ; carbonate of barium is then added in excess ; and the whole
is left to stand for twelve or eighteen hours, and shaken up fiK>m time to time. The pre-
cipitate, eonsisting of sewjuioxide of cobalt and carbonate of barium, is then coUected
on a filter, and washed with cold water. The filtered liquid, which has a pure green
colour, contains all the nickel without a trace of cobalt The precipitate is boiled with
hydrochloric acid to convert the sesquioxide of cobalt into protoxide, and dissolve it
toffether with the baryta; the latter is then precipitated by snlphuiic acid, and the
cobalt from the filtrate bj potash. The nickel is also precipitated bjr potash, after the
removal of anj baiyta that the solution may contain by sulphurie acia This method,
if properly executed, gives very exact results. The chief precautions to be attended
to, are to add a lar^ excess d chlorine, and not to filter too soon, because the preci-
pitation of sesquioxide of cobalt by carbonate of bariom takes a long time.

According to Heniy, bromine may be used in the preceding process instead of
chlorine as the oxidising agent

Liebig has siven > everal methods of separating these two metals, founded on the
difference of uieir reactions with cyanide of pc^aseium. 1. The oxides of the two
metals are treated with hydrocyanic acid and then with potash, and the liquid warmed
till the whole is dissolved (pure cyanide of potassium, free from cyanate, may also be
used as the solvent). The reddish-yellow solution is boiled to expel 6ree hvdrocyanic
acid, whereupon the cobaltocyanide of potassium (KCoChr*), formed in the cold, is
converted into cobalticyanide (KKJoKy*^, while the nickel remains in the form of
cyanide of nickel and potassium (KNiCy*! Pore and finely-divided red oxide of
mercoi^ is then added to the solution while yet warm, whereby the whole of the
nickel is precipitated, partly as oxide, partly as cyanide, the mercury taking its place
in the solution. The precipitate contains all the nickel, together with excess of mer-
onric oxide ; after washing and ignition, it yields pure oxide of nickel The filtered
■olution contains all the cobalt in the form of cobalticyanide of potassium. It is
supersaturated with* acetic add, boiled with sulphate of copper, which precipitates the
eobalt in the form of cobalticyanide of copper (2Cu'Go'€>y*.7H'0), and tiie precipitate
retained in the liquid at a boiling-heat till it has lost its glutinous character. It is
then washed, dried, ignited, and dissolved in hydrochloric acid mixed with a little
nitric acid ; the copper is precipitated by sulpfay&e acid ; and the filtrate, after boiUx^
for a minute to expel the excess of that gas, is mixed with boUing caustic potash to pre-
cipitate the cobalt (Ann. Ch. Pharm. 1x7. 244). -^2. Instead of addinff the oxide of
mercury, the solution containing the mixed cyanides may, after cooung, be super-
saturated with chlorine, the precipitate of cyanide of nickel thereby produeed being
continually redissolted by caustic potash or soda. The dilorine produces no change
in the cobalticyanide of potassium, but decomposes the nickel-compound, the whole <^
the nickel being ultimately precipitated in the form of black sesquioxide. (Ann. Ch.
Pharm. Ixxxvii. 128.)

laebig's first method (j3nd, xlL 291), which consisted in treating the solution of
the mixed cyanides with excess of hydrochloric or sulphuric add, whereby the nickel
was predpitated as cobalticyanide of nickel, leaving a solutiofi of cobalticyanide of
potassium, has been found, both by himself and others, not to pre perfectly satis-
mctory results. The method by oxalic add (p. 34), and the predpitation of nickel
fh)m an ammoniacal solution of the two metals by potash (see Nickel) are not sufii-
dently accurate for quantitative analysis.

F. daudet separates cobalt from nickel and other metals in the form of the ammonio-
compound described on page 46, that compound being very insoluble, while oone-
spending compounds of the other metals do not appear to be formed under the same
circumstances.

From uranium, in the state of sesquioxide, cobalt, as protoxide, may be separated
by means of carbonate of barium, which throws down the uranic oxide and leaves the
cobalt in solution. (For other modes of separation, see Ubaniux.)

From sine, cobalt may also be easily separated by predpitation with niiriU of
potassium. Another mode of separation is : Convert the two metals into chlorides,
and reduce the chloride of cobalt with hydrogen, as described for the separation of
colmlt from manganese; the chloride of zinc then remains unaltered, and may be
dissolved out. Thirdly, the metals may be predpitated by carbonate of sodium, the
carbonates dissolved in a large excess o£ acetic add, and sulphydric add gas passed
throuffh the solution. The sine is thereby predpitated as sulphide, while the cobalt
remains dissolved. To ensure complete separation, it is necessary to add a h^ve
excess of acetic add. Fourthly, the separation may be eflfected by predpitating lM
cobalt as sesquioxide, by means of peroxide of lead (p. 38).

1048 COBALT, EARTHY— COBALT : OXIDES.

^. Valuation t>f Cobali'Ore4»^The valna of a eolwlt-on is estimated eHbtr
hy the amount of piotozide that it will yield, or bj its power of impaztixig a hlae
colour to glass and enamel (For the latter mode of Talnation we lefer to tbe aitide

SXALT.)

To estimate the quantity of protoxide contained in a oobslt ore, the oire may be
treated by either of ike methoas already siTen (pp. 3S, 34^ to separate the arsenic,
copper, iron, &&, the cobalt being afterwards seponted from the nickel, and estinaled
by either of l^e processes deseribed onjpp. 38, 39.

(For Plattnei^s method of estimation in the dir way, see his freaiue on the Momuim^
translated by Miispratt» also £srf s HStUnkSnde, m. [1] 340, 342).

6. Atomic Weiffkt of Cobalt — Dnmas has determined the atomic weiglit of
cobalt by the qnantaty of silyer reqnired to decompose a known weight of the duoride.
Pore metsUic cobalt was dissolTed in nitro-moziatio add, the eolation evaporated to
diyness, keeping the hydrochloric add continnally in excess ; the reddoe ignited in a
stresm of hydrochloric add gas, or else heated in yacno ; and the diloxide of eofaah
thns obtained was decomposed by nitrate of silrer. Five experiments thna made gave
for the atomic weight of cobsit niunbers Tarying from 29*60 to 29*69. Dumas z»-
gards 29*6 as the oorrect number (Ann. Ch. Phann. cxiii 24). This sgrees with the
original detennination of Roth of (Po^« Ann. riii. 186), which was made by eon-
▼erting a Imown weiffht of the protoxide into chloride, and 'dien predintating bj mtixte
of silyec S ehn e i d er (Pogg. Ann. d. 3 1 7), from the analysis of the oxalate, estimated
the atomic weight of cobah at 30 ; but the number 29*6 is generally regarded

OOBA^Tf MAMVMTt or J^folan, — A rariety of wad or eaztiiy
containing oxide of cobalt (See Makoahbbb, Oxidss of, and Wad.)

COBA&Tt V&VOSZBB OV, CoF, maybe obtained bydinolTing coibaltoiia oadde

or carbonate in aq«ecns hydrofluoric add. The solution yields by evaporation m*n
irregular rose-coloured crystals containing CoF.BjK). The compoond oiasolvca with-
out decomposition in water containing see hydrofluoric add, or in a small quantity
of pure water ; but with a larger quantify of watei; it ii resolyed into an add liquid
containing cobalt* and an insoluble pale red bade salt consisting of 2Go^F^.H^. or
2iChO.CoF) + HO,

Fluoride of cobalt unites with the fluorides of smmonium and potMsinin, forming
sparingjly soluble double salts which ctystsUise in pide red granular ayatsla. (Ber-
zelius.)

CM>BA&Tv XCnEDM OV. Col, is produced by digesting flnely diyided «M^f*TK<t
cobalt with iodine and water, the mixture becoming hea^ to the boiling point. With
a small quantity of water, it forms a green, and with a larger quantity, a red solntioo,
and remains, on eyimoraticm, as a dark green ddiquescent mass soluble in *WhoL
(Erdmann, J. pr. Gnem. yii 364.)

Ammonio'iodidet of Cobalt. — ^Iodide of cobalt absorbs 3 at ammonia-gas, forming the
compound, GoL2NH', which is a reddish-yeUow powder. A ooncenteated sohitioo of
iodide of cobalt forms with ammonia a reddish-white predpitate whidi diseolyes on
heating, leaying only a few green flocks. The solution depodts small rose-colomed
erystala, which, as well as the reddish-white predjpitate, consist of CoL2NH', bat
appear also to contain waiter. When dried, they giye off ammonia^ turn btown and
afterwards green. Water decomposes tbem. liberating ammonia and depodting a green
powder. A dilute solntion of iodide of cobalt forms with ammonia a blue ptedpitate
which turns green when exposed to the air, and a brown solution. (Bammelaberg,
Pogg. Ann, uriii. 166.)

OOBA&Tf oauCDas or. The following oxides of cobalt are known :

Protoxide or eobaltous oxide 06*0 or CoO

Sesquioxide or cobaltic oxide CoH)* or Co*0^

{Co»0« orCb*0«
Co"H)* or Ct^C
Co»«0» or Cfa»0»

The protoxide is a strong, the sesquioxide a weak base. According to Fr^my, the
oxide GoH)* is also a salifiable bsse, which unites directly with acetic add and exists in
some of the ammoniacal salts of cobalt. Fr^my has also obtained salts of this nature
containing a dioxide of cobalt, CoH)*.

Protoxide of Cobalt or Cobaltous Oxide, Co*0. — ^This oxide is obtained by
igniting eobaltous hydrate or carbonate in dose yeesels ; by igniting the piotochloride
in a stream of aqueous yu)our (Schwar z enberg) ; also, mixed in yarions proportions
with sesquioxide, when imely diyided cobalt bums in the air, or when the conmaet
metal is heated to redness in the air. The pure protoxide is a light gneinah-gttyot
olive-green non-magnetic powder. It is reduced to the metallic state at a red heat by

COBALT: OXIDES. 1049

IiTdroflen, cbarooal, carbonic oxide, potaBsiam, and flodiimi. When heated "with sol-
phur, it ia converted into sulphide of cobalt and aalphuroiu anhydride ; and with
■olphydric acid, it yields water and sulphide of cobalt

Hydrated eobaltous oxide, or Cobaltons hydrate, CoHO, or OoOMO, is nzodnced
when a cobaltons salt is decomposed bjr potash out of contact of air. ▲ bine basic salt
is flzst produced which ehuiges gradually at ordinary temperatures, quickly, on boiling,
into the rose-coloured hydrate. If the cobalt^solution be dropped into strong boiling

Sotash-ley, the change nom blue to red is almost too rapid to be traced. Oobaltous
ydrate is a powder of a dingy rose-red colour, which gives off water at 100^ C, and
is converted into the protoxide if the air be excluded, into a higher oxide if exposed
to the air. It dissolves readily in adds, forming the eobaltous salts.

8es^uio*id€ of Cobalt^ Cobaltie Oside, CoH)*, is formed when chlorine is
transmitted through water in which the hydrated protoxide is suspended, or when a
salt of the protoxide is precipitated by a solution A chloride of lime. In the former
ease, water is decomposed by the dilorine, and hydrochloric acid produced, while the
oxygen of the water peroxidises the cobalt :

2CoK) + H«0 + Cl« - CoW + 2HCL

The sesquioxide of cobalt is precipitated as a black hydrate^ which, when cautiously
heated to 600^ or 700^ C, vields the black anhydrous oxide. When ses^ioxide of
cobalt is digested in hydrochloric add, chlorine Ib evolved, aiidthe nrotochlonde formed.
Exposed to a low red heat, ^e SMquioxide loses oxygen, and tne compound oxide,
CoK).CoH)*, is produced (Hess). When protoxide of cobalt is calcined with a borax
glass, at a moderate heat, it absorbs cujgen, and a black mass is obtained, which,
mixed with manganic oxide, serves as a bhuk colour in enamel painting.

SesquioxidA of cobalt acts as a weak base. Phosphoric, sulphuric^ nitric, and hydro*
chloric adds dissolve its hydrate in the eold, without decompodtion at first, but the
resulting salts are afterwards reduced to salts of the protoxide. A protosalt of
cobalt containing a small quantity of a sesquisalt is somewhat deepened in colour. The
most permanent of the sesquisaltB is the ac e t ate ; the hydrated sesquioxide while yet
moist dissolves in acetic aad, slowly but completely. Hie solution, which has an in-
tense brown colour, forms a brown predpitate with alkalii and alkaline earbonatet,
Withferrocyanids of potamum, it forms a dark predpitate^ which, if the predpitant
IS in excess, gives up cyanogen to it, converting it into ferrii^anide of potasdum and
bdn^ itself converted into green ferroeyanide of cobalt Alkaline oxauUea colour the
solution vellow, forming an oxakte of the oxide Co*0*, or Co*01

CobaUosO'eobalUo oxides.—a. The oxide, Co*0« or Co«0* - Co*O.Co*0", isob-
tained in the firee state by heating the nitrate or oxalate of cobalt, or the hydrated ses-
quioxide^ to redness in contact with the air (Hess, Bammelsbere); but according to
Beets and Winkdblech, the oxide thus obtained is C6"0\ When the reddue obtained
by eentlv i^ting the oxalate in contact with the air is digested in strong boiling
hyarochlonc add, the oxide Co*0* remains in hard, brittle, greyish-black microscopic
octahedrons having a metallic lustra. The same oystalline compound is obtained by
6taK>ngly igniting £y protochloride of cobalt^ ^one or mixed with sal-ammoniac, in dry
air or oxy^^ gas. ^Schwarsenberg.)

This oxide, according to Fr^my, is also a salifiable base. The corresponding oxal a t e
has already been mentioned. The ace tat e is obtained by digesting in dilute acetic add
ihe hydrated oxide obtained by continued action of oxygen on the blue predpitate thrown
down from ordinal cobalt-salts by potash not in excess. Frimy also states that when
chlorine is passed into the solution of ordinary acetate of cobalt, a brownish-yellow salt
is formed containing the base 00*01*0*, or Oo*0* in whidi 1 at. O is replaced by 01*.
This chlotine-bsse exists also in some of the ammonio-compounds of cobalt (p. 46).

b. The oxide, Oo>*0' - 30o*0.0oK)*, is ssid b^ Winkdblech to be farmed bv keep-
ing the hydrated protoxide at a zed heat in the air for a condderable time, or dj first
reducing it to the metallic state by^ heating it very gently in a stream of hydrogen, and
then burning it again by passing air through the tul^ According to Bammelsberg,
however (Pogg. J^in. Ixxul 93), the oxide obtained bv dther of these nrocesses is Oo*0*.

e. Anotiier oxide, 00**0* » GOo'O.OoH)', is said to be obtainea br predpitatang
cobaltie nitrate with ammonia, exposing the liquid to the air till the blue predpitate
turns green, then BUSfNendiiur the predpitate in water, and exposing it to the air for a
month till it turns auite yeUow. But the yellow hydrate thus fbimed always retains
a trace of nitric add, whidi cannot be removed even by long contact with water.

A eobaltie acid (or anhydride), Oo*0*, is obtained in combination with potash, by
strongly igniting the oxide, Oo*0', or the protoxide or carbonate, with pure nydrate of
potassium. A crystalline salt is then formed which, when dried at 100^ 0^ contains
ETO.SOoH)* + 3aq., and eives off 1 at water at ISO®. (Schwarsenberg.)

Dioxide of Cobalt^ OoO, or Oo*0*, has not been obtained in the ftee state, but
may be supposed to exist in the oxycobaltic sidts (p. 00).

1060 uuuAiJi ; <jA.iouijriiix»E. — ouLirtiiiJii.s.

OOBAKT, OKISUUrKOBM OV, Co*90, <a CbACbO.— Frodoeed ly ignHing
the mlpluita in hjdrofjen gia. Water and mlphnnin* Mad taaipe, tui diere iBtaitt
k dark grrj nnUrad nuas which i> not sltemd h^ Uie fnithcr actum at Oia hjdiogai.
Cold hTdrDchlorie add decompoaea it, diaiolTiiig oxide of cobalt and laavii^ rali^uda;
bat if heat b« applied, the lolphide likewise dinolTea. (Atfradion.)

tJOBAXV. OXTOKW-aAXiTB OT^-The eobaltooa lalti aw prodoMd hj- d>-
•oliing metallic cobalt in the atronger aeida ; bj the aetioD of aodt on the protoxide
hydrate, or carbooata ; hj boiling the hydrate or earbonstv in aotntuma ot nmmonia-
■alts, ammonia bring then eTOlTed and a eobaltona aolotion ftomed ; and bj cn^ata-
tion. The esibonatiE^ phoapbat«, bont«, silieate, and tfaoM vhiefa contain metaillie aodt,
wra inaolidile in water ; mnrt of the othan are sohiUn. The inaohiUe aalta hwrt a
Tiidet or peaeh-Uoaaom colour ; the diaalTod nits a roae ocloor. Tbft nmtiml Hia-
tiona redden litmn* alightlj. For their rcactiolui and thooe of the eobaltic aalta, ne
pp. 37, S8.

OOaAKT, VMOaVMnaXB op. — The trieobalUe pliotpiide, or trinobait-fkm-
plane, Co7, was obtained b^ H. Boae aa a gnr powder, on paving bydnigengn onr
baaic phoapbota of cohslt ignit«d in a poreelam tube. It is slao piodncnd b; the
action of phoaphoretted hjdrogBD on ehlmide of oobalt.

Another pboaphid* containing a 107 lafge exceaa of cobalt !■ prodocrd wiica pueca
of phoapbonu an thrown on led-hot cobalt ; when 1 pt of the metal is ignited with
7 pta. glseial pbosphoiic acid and ^ ehamnl powder; and when a mizton at
TO pta. mflallie cobalt or oxida of ooball, 100 bona^aah, SO ponndad qnarti, ftod 10
eharooal is nrponnd for an hoar to tha beat of a blaat-foraacsL The eonptinud {■«■
pared bj the fliat or aecond method is blnisb-whita, with metallio hiabe, brittle, cS
adcoUr atmctoio, more ftuible than cobalt, cootaine 6 per cent phospfaonut acd bnu
to a dark bine glasa when heated (Pelletier). The product otilsiard br the third
proceaa is of a ahining white coloor, toj fnsibl^ non-aagnetio, and often haa aeedle-
ahaped crystals in iti cavities.

OOSAVr, MMB. Sjn. with COBU,T-BU>nx (p. SI).

OOBAIiT. >SZSWII>B OT. Heated cobalt nnitaa with aelenlnm, ftnning a
grey msH. which exhibits metallie luetic and ciTBtalliDe stmctnn, and melta at a nd
heat; the combinatioD is attended with ignitum. (Berielina.)

OOB&&T. STrXFKXSaS OV. The pretoiulpAide, Co^ or OaS, ocen*
DBtive as Syepooritc^ > massive minaisl of staal-g^ colour inclining to yvllow,
fbond diseeminated in grains or veins in sndent swiits, associated with magnetie
pyritea, at Svepoor, near S^^pootaniih, in North-west India. It is employed 1^ the
Indian jewenen to nve a rose-colour to gold. According to Hiddleton'a analysis
FhiL Ahg. [3] iizvm. 8fi2), it contains 3S-36 S, and 61-64 Co, agreeing clooely with
the formula (JO'S.

The piotOTulphidema^bo prepared by throwing mlphnr on red-hot cobalt eontaiiKd
in a ret«rt, also by beabiig the protoxide with solphTir, and by igniting cobaltona sol-
tihate to whitenese in a cmcible lined with charcoaL As thus obtained, it ia a grey
laminar mass having the metallic InEtre ; according to Berthier, it ia magnetic In
the wet way, it ia prodaced by predpitsting cobaltons acetate with sulphy^ie add or
•ny DCDtrBl cobaltons aolution with an alkaliQe snlphide. The predpitate is a blail
powderwbich gives ofFwater when heated, and in the moiat state slowly oxidiaea in tha
air, beiDg converted into snlphate. It is inaolnble in alkalis and alkaline snl^dea,
•olnble in concentrated mineral acids, iniolnble or nearly so in dilnte acias. It
nniteB with add snlphidea, forming Hnlphnr-salls, which are all insohibla in water.
According to Anthon, it decompoaea the aolntions of other metals, e. g. iron, nidel,
copper, and ailver, a sulphide of the other metal being precipitated and ths cobalt
taking its place in the solntioQ. This appears somewhat inconsistent with the action
of diSite hydrocblorie add on a mixtore of the sniphidee of iron and cobalt, whidi,
according to H. Kose (p. SSI aflbids a method of completely aepsiating cobalt btga
iron. It unites with peroxide of cobalt, forming an o^ndplude (e»t n^).

St(;uisti/pAi<f«D/(7Dia;f, or C^Diaf(Dll«5<(IpAiif(^ia obtained by precipitating
eobaltic acetate with solphydric add, or by heating eobaltic hydrats^ bnt not to redneaa,
in an atmosphere of the same gas. It has a dark grey eolonr. AecordingtoFcllen-
beTg(Pogg.Aim. 1. 73), it is olSainedin graphitic lamiiuebyignitingthepnrtODde with
■nli^ni uid an alkali. LinnmU or cobati-pyriict is commonly stated to be a aeaqm-
snlphide, bnt its composition approaches more neaily to that of the (bllowing compound :

Ceballoto-eobaltie Svtphide, Ca'3', or Co'a.Co'8'. or Q^S' - Coa.O^».—
LiiaimU from Hiisen, near Siegren, in Fmssia, has nearly thia composition, yielding
according to Wsmekuik's analysis, 43'2S S. 6iSB Co, O'BT Cn, and 3'30 Fe — SS'87,
theformola requiring 12 8 and 58 Co (Dana, ii. 66). In moat varietiet of this minenl,
however, the cobalt IS replsoedtoagreaterextentbynq^ietM-niekel. (See Lmxin.)

COBALT-BASES, AMMONIACAL. 1051

Oxymlpliide of cobalt heated in sulphydric acid gas yields a product which appears
to be a sulphide intermediate in composition between the proto- and seaqui-sulpMdes,
(Anthon.)

Disulphide of Cobalt, CoS^ or CoS*, may be supposed to exist in combination
with arsenide of cobalt in cobaltine (q. v.)

eOBA&T-BASas, AMlia«XJLOA&. (F. Glandet [1857], PhiL Mag. [4] ii.
268.—Genth, Ann. Gh. Pharm. Izzz. 276.— Fr^my, Ann. Ch. Fhys. [8] zzxr. 267.—
Bogoiski, ibid, zli 446. — Gregory, Ann. Ch. Irhann. IzzxriL 126. — Gibbs and
Genth, Smithsonian Contributions, 1866 ; SiU. Am. J. [2] zzziiL 234, 819 ; zzxiT. 96 ;
Ann. Ch. Pharm. ciT. 160, 296 ; Jahresber, d. Chem. 1867, 227. — Knnzel, J. pr.
Chem. Ixzii. 209 V — Cobaltous raits treated with ammonia in a Teasel protected from
the air unite with the ammonia, forming compounds which may be called ammonio-
cobaltous-salts. Most of them contain 8 at. ammonia to 1 at of the oobalt-salt;
thus the chloride contains CoCL8KH* + ^aq.; the nitrate CoKO*.3NH* + aq. They
are generally crystaUisable and of a rose-colour, soluble without decomposition in am-
monia, but decomposed hy water, with fSonnadon of a basic salt (Frimy). H. Boae,
by treating dry chloride of cobalt with ammonia-gas, obtained the compound CoCL2NH',
and in like manner an ammonio-sulpfaate has been fonned containing Co^BO*.6NH".

When an ammoniacal solution of cobalt is exposed to the air, oxygen is absorbed,
the liquid turns brown (p. 87), and new salts are formed containing a higher oxide of
cobalt (either CoH)* or CoK)*), and therefore designated generally as per oxidised
ammonio-cobalt salts. Sereral of them containing different bases areoftenfoimed
at the same time.

Most of the perozidised ammonio-cobalt salts are composed of sesquisalts of cobalt
(oobaltic salts), united with 2 or more molecules of ammonia. The composition of the
neutral salts may be illustrated by the chlorideS) as in the following table :

Diammonio-cobaltic chloride Go*Cl*. 2NH*

Triammonio^cobaltic chloride Co'Cl*. 3NH"

Tetrammonio-cobaltic chloride C6*C1*. 4NH'

Pentammonio-cobaltic diloride Co'Cl'. 6NH*

Hexammonio-cobaltic chloride Co*Cl'. 6NH"

The formul» of the corresponding neutral nitrates are deduced from the preceding
by substituting NO* for d; for the sulphates, oxalates, and other dibasic salts, the
number of atoms of cobalt and ammonia must of course be doubled. Thus, om^ammonto-
eobaltio sulphate - Co\SO*)*.I0NH>. Thero are also several acid and basic salts of
the same ammonio-molecnles, the formula of which will be given further on. Further,
thero is a dass of salts oontaininff the elements of nitric oxide in addition to am-
monia, e. ff, pentainmoniiMutroto-^sooaltie oxychlorids » Co*Cl^O.10NH'.2NO. Lastly,
Fi^my has obtained ammoniacal compounds (oxycobaltic salts) containing salts of
cobalt conesponding to the dioxide CoK)'.

DiAxvoNio-ooBA.LTia S^LTS. — The sulphite of this group is obtained by
addinff add sulphite of ammonium to an aqueous solution of pentammonio-cobaUic
chloride containing a veiy small quantity of ammonia, till the odour of sulphurous
add becomes distinctly perceptible ; on leaving the solution to stand for some time, the
sulphite separates in brown, nearly insoluble octahedrons^ containing Co\SO')'.4NH'
•i-6aq. (KunseL)

TBXiLXXOKio-coBA.LTio SA.LT8. — Whdu a solution of pentammonio-cobaltie
chloride containing a little ammonia, is mixed with so much add sulphite of ammonium
that the liquid does not smeU either of ammonia or of sulphurous acid, it changes colour
from red to deep yellow, and deposits triammonuhcobaltie sulphite, CoXSO')'.6NH'
•f aq., as a yellow powder or in ciystalline needles, according to the temperature and
concentration of the liquid. It is insoluble in cold water, and is dowly decomposed
by boiling with water. Its formation is expressed by the equation :

2(Co«Cl».6NH*) + 2NH" + H»0 + 6(NH*.H.80») -

[Co*{80»)».6KH» + HK)] + 6NH«CI1 + 8[(NH*)«.S0^. (KunaeL)

Tbtbaxxonio-cobaltzo Salts. Fr^my's Fuaeo-eobaltie eaits.^^Thcme salts
aro formed when an ammoniacal solution of a cobaltous salt is eaqMsed to the air, and
b^ the action of water on oxy-cobaltio salts. They «re brown, and mostly nncrystal-
lisable, but may be obtained in the solid state by predpitation with alcohol or excess of
ammonia. They aro slowly decomposed bv boihx^ with water, but quickly on addition
of an alkali, with evolution of ammonia and predpitation of oobaltic hvdrate. They are

bade salts, the nitrate containing Co«0<.2KK>*.8NH* -f H*0, or [q^^^|0'.4NH*,

and the l^fpoeulphaU Co*0«.2S»0*.8NH«,

COBALT-BASES, AMMONIACAL. 1053

The Bolution lias an alkaline taste and reaction, absorbs carbonic acid from the air,
and decomposes •with facility. — Pwrwtreo-^obdUiG oxide, obtained in like manner, forms
a violet-rea alkaline solution, which absorbs carbonic acid from the air, and suffers
decomposition when concentrated.

Nitrates, — The neutral or raeeo'oobaltio nitrate, is obtained, as a shining yellow
precipitate, when an ammoniacal solution of cobaltous nitrate is left to oxidise in tne air,
(crystals of Fr&my's ozycobaltic nitrate are fre<;|uently also formed at first, but subse-
quently disappear). The deep wine-red liquid yields, by spontaneous evaporation, red
crystals, containing GoXNO'^.5KH'. + HK), easily soluble even in cold water. Accord-
ing to Dana, they are monodinic combinations oo Poo . [ooPoo] . + Poo . — Poo . 00 P.
Inclination of faces, oo P : oo P in the dinodiagonal principal section «<■ 103^ ;
00 Poo : Poo mm 140° 80' ; 00 Poo : —Poo « 136°. From the solution of these crystals,
or firom the original oxidised ammoniacal solution, nitric acid added in the cold
throws down a brick-red precipitate of the hydrated salt; but on boiling the liquid
with nitric add, the anhydrous nitrate, Co'(NO')'.5NH', is thrown down as a yiolet-
red crystalline precipitate. It dissolTes in dilute anmionia and seroirates from the
solution by spontaneous eraporation in dimetric crystals P . Poo . oo P . oo Poo . 3P3.
Inclination of P : P in the lateral edges, » 82° 40'. This anhydrous salt is nearly
insoluble in cold water, more soluble in hot water, but the solution is easily de-
eomposed by heat; addition of nitric acid prevents the decomposition. The anhy-
drous salt explodes when heated, giving off nitrous vapours, and leavinffbladc
sesquioxide of cobalt. — A basic nitrate, probably Ck>H>*.2N*OM0NH" + 7HH) or

}co*^^ H [ 0''6I7H' + 3HK), is obtained in purple scaly crystals, when a solution of the

hydrated neutral nitrate, mixed with a large quantity of nitrate of ammonium and a
little free ammonia is left to evanorate. These crystals are decomposed by solution
in water, and when boiled with hydrodiloric acid, yield with brisk effervescence, a

Ole-red solution and a deposit of purpureo-cobaltic chloride (Gibbs and Genth).
I this basic nitrate and the anhydrous neutral nitrate appear to belong to the so-
called puipuzeo-cobaltic |proup. Kilnzel, by exposing an ammoniacal solution of
eobakous nitrate to the air till it had acquired a dark olive-brown colour, and then
adding nitrate of ammonium, obtained a yellow crystalline precipitate^ to which he
assigns the formula 2(CoH>*.10KH').5N*0.

Oxalates.'— BosetheobaUio oxalate is precipitated by oxalate of ammonium from
a solution of the chloride immediately, from the nitrate very slowly ; it may be puri-
fied by recrystallisation from water containing ammonia. The cherry-coloured crys-
tals, which are rhombic prisms of 101° 48', with a brachydome of 108° 64', contain

iGo^V' I ^-^^^^ + 6aq. ; they are neariy insoluble in pure water. The basic, or jwr-

pwreo^eohaltie om/a^ >q^4Nv1 |0*.dNH'-i>3aq., separates in violet-red needles on

adding oxalate of ammonium to a solution of purpureo-cobaltic chloride.

Oxalo- sulphates.^ Ajxt add oxalo-^ulphate, GoH>*.2CK)'.2SO*.10NH*-i' 3H>0 or

(CK)')")
(S0*rl0^5NH"-fHK), 18 obtained in brick-red, ill-defined needles by boiling

<Co»)'^j

roseo-cobaltic sulphate for several honn with excess of oxalic acid. The solution

of this salt assumes a violet-red colour on addition of ammonia, and, if exactly

neiftraliBed, yields by evaporation prismatic crystals of a basic oxalo-^tdphate.

(SO*)* VO^.IONH"-!- 7H*0, which is mtfre soluble than the acid salt* and is easily de-

((?0«>
?S0»)*
(Co*)"
composed by boiling.

'Sulphates, — Bosetheobaltic sulphate is generally (but not always) produced in an
ammoniacal solution of cobaltous sulphate by atmospheric oxidation, the liquid be-
coming firat brown and then dailc red. On carefully adding sulphuric add to this red
solution, the sulr^te is deposited as a brick-red crystalhne powder, whidi may be
purified by washing with cold water and redystalHsation from a slightly addulated

solution. The eheny-coloured crystals, containing >qu4^^>O*.10NH' -i* 613*0, are,

according to Dana, dimetric combinations, P . 2P . Poo . OP . ooP . ooPoo . Indination
ofP : Pin theterminaledges * 107° 20'. Length of jpndpal axis - 1*0866. The
■alt is nearly insoluble in cold water, sparingly soluble in bouing water, and crystal-
lises from the solution on cooling. It dissolves in dilute ammonia, and crystallises
unaltered ftom the pnzple-red solution. On boiling the neutral salt* a dark brown

1054 COBALT-BASES^ AMMONIACAL.

powder Beparates, which, after diying in the air, contains CoK)* -i- SWO, wiul» Intto-
cobaltic sulphate Temaina in solution, being, howerer, partially deeompoMd.

An aeid(jpurpure<H»baltie)9u^hate, CoK)«.iSO».10NH'+ 6H«0,or , (^1^ 0*.gSB*

•f 2H'0, is obtained hy miziiig the anhydrous chloride (p. 46) with oil of Titriol to a
thick poll), diluting the solution with twice its bulk of water, as soon as the erolutiao
of hydiochlorie acid has oeased, then washing the yiolet^red needles which sepante
with a little cold water, and pressing them ; also bj adding oil of Titdol to zoseo-
oobaltic sulphate till an oily hquid is produced ; digesting this for an hoar or two^
taking care to aToid escape of oxycen, diluting the erolred purple solution with an
equal bulk of water, ana recrystaUising. The crystals are red prians ; aeecrdh^

to Dana, rhombio hensihedxal eombinations, ooP . ooj^oo . ^oo • -^ • o»f2. In-

dination of ooF : a>P - 1069; }f»<x>: ^ao, on the principal axis » 122947:. The
salt has an acid taste and reaction, dissolyes easily in water, but is quickly oooTcrted
into the neutral (roseo-cobaltic) sulphate ; especially by slow evaporation of a ■ol"«Mi^
prepared with the aid of heat, (Qibbs and Genth.)

Sulphite. (^vL\ O'-^NH* + |H*0.— Black-brown, heavy, amorphous pnaphatfl^

formed when sulphurous acid gas is passed through a dihite ammoniacal solution of
pentammonio-cobaltic chloride ; also by passing the gas through water in which tzi-
ammonio-oobaltic sulphite (p. 45)is suspended. It is insoluble in cold wate^ and is
decomposed by boiling water. (KiinzeL)

NiTBOSO-PBNTAKHONIO-COBALTIG, Or X ANTHO-CO BALTIO SaZ.TS. (Gibbs

and Genth, loc. dt.) — These salts are produced by passing the nitrous yapours evolved
from a mixture of nitric acid and stardi or sawdust, into ammoniaeal JtrtlnH^yn^ of
oobaltous salts, or into neutral, add, or ammoniaeal solutions of roseo- or pmpmeo-
oobaltic salts. The gas is absorbed ; fiimes of carbonate of ammonia make their appear-
ance ; the liquid gradually assumes a dark reddish-brown colour, and then, on eoolii^
generally deposits a xantho-oobaltic salt.

Xantho-cobaltic salts are brownish-yellow, more soluble in water than the loseo-
or purpureo-cobaltic salts, the dilute solutions having a yellow, the more oonomtzated
solutions a dark brown colour. Thev decompose, though not easily, when these solu-
tions are boiled - sometimes also bdow the boiling temperature — giving off a.intwft»M^
and depositing a dark-coloured heavy powder. The addition of a few^drops of aoetie
acid prevents this decomposition ; but, on adding a small quantity of an inorganic ad^
nitric oxide gas is evolved, and a purpureo-cobaltic salt is formed, which, howew, ■
difficult to separate ftom the undecomposed xantho-cobaltic salt

The xantho-cobaltic salts appear to have the composition of sesquisalts of coImII;
associated with 6 or 10 at NH>, 1 or 2 at NO, and 1 or 2 at water. /mmrwm «

The chloride, or rather oxychloride, CoH>ClM0NH«.2NO+H«O, or [^i^[

5NH'.N0, is not produced by either of the reactions just mentioned, but may be
prepared by decomposing the sulphate with chloride of barium, and evaporating the
filtrate at a gentle neat, after adding a few drops of acetic add. It forms brownish-
yellow, iridescent crystals. Its solution, mixed with tricht4>ride ofgold^ yields a double
salt, which, by recrystalUsation from hot water, is obtained in Inownuh-yeUow, iri-
descent prisms, containing Co«OClM0NH*.2KO.2Aua' + 2HK).— The 0 A/or oo/a<u
nate, C!o^OClM0NH*.2NO.4PtCl' + 2H*0, is nearly insoluble in water, but ma^ be
crystallised from hot dilute hydrochloric add. The chloromereurate, Co*OCl\
10KH'.2NO.8H^ + 2H'0,is obtained bypredpitation in pale brownish-yellow lamina;
by reerystallisation from hot slightly addulated water, in brownish-yellow needles

Xantho-cobaltio ferrooyanide, Co*OCy*.10NH».2NO.2Fe(>+ 7H«0, ie ob-
tained by prednitating the nitrate with feirocyanide of potassium (the s^utiona of the
chloride and sulphate are merely douded by that reagent) in orange-yellow priamatie
ciystals, which give up their water easily and without decomposition, are iMftiwbtft in
cold water, and are decomposed by hot water.

The nitrate^ which is a basic salt, containing Co^O*.2NK)M0NH'.2NO + H^,

OF /i ,Y"H [ ^''^^^'^^' fonns b'ght brownish-yellow quadratio prisma^ having

F : P in the lateral edges, between 100° 45' and lOl^ 15'.

The oxalate, Co*O«.2C»O«.10NH».2NO + 5HK) - .^^^^|o^5lm»JffO+ ia

obtained by nrecipitation in yellow acuminated crystals^ insoluble in odd, sparindk
■olnble in bouing water, decomposed by boiling.

COBALT-BASES, AMMONIACAL. 1055

The*tt/i?Aa<«,Co<O«.2SO».10NH».2NO + H«Oor, (®^*i!^|o».5NH«JTO, cryetal-

Usee in thin platei, apparentlj rhombic. It dissolTes in stroiup sulphuric acid, giving
off bat little nitric oxide, and forming a red oily liquid, which giyee off nitnc oxide
abundantly on addition of water, whue the remaining liquid consists dbiefly of am-
monio-cobaltons sulphate, usually mixed with a small quantity of acid puipureo-co-
baltio sulphate.

Hbxavkonio-oobaltic, or Lutio-oobaltio Sai.t8. (Fr^my; Gibbs
and Oenth, loe, «»<.)— These salts, disoorered by FrAmy, are often produced hj the
direct oxidation of ammonio-cobaltous solutions ; frequently also by the decomposition
of pentammonio-cobaltic salts, although their molecule contains an additional atom of
anunonia. They are of yellow or brownish-yellow colour, more soluble in water than
the zoseo-oobaltic salts, and yield browmsh-yeUow solutions. They are Tery permanent
, in presence of acids, but are decomposed by continued heating with sulphuric acid ; in

neutral or alkaline solutions they are easily decomposed by boiling.

Lutethcobaliio ohloride^ CSo^Cl'.GNH*, is often formed during the oxidation, by

exposure to the air, of an ammoniaeal solution of protochloride of cobalt mixed with a

la^e quantity of coarsely-pounded sal-ammoniac (in other cases, the products are

roeeo and purpureo-cobaltic chloride) ,* almost always, if the ammoniaeal solution con-

' tains sulphate of cobalt as well as chloride : in the latter case, a salt is formed contain-

I ing sulpnurie and hydrochloric acids, and this, when boiled with ^drochloric acid

{ and chloride of barium, yields a solution of luteo-cobaltic chloride, ^nds salt^ purified

, by repeated crystallisation, forms brownish orange-coloured crystals of spedflc era-rity

1*7016. Th^ belong to the trimetric system, and, according to Dana, exhibit the

faces ooP . OP . ]Pao . 3&oo , two faces, ooFS, on one side only of the macrodiagonal,

and four faces, fP, lying in one zone. Inclination of ooP : ooP b 113^ 16'. n dis-

■olyes easily in boiling water, and separates for the most put as the solution cools.

It is precipitated unaltered by hydroddoric add and the chlorides of the alkali-metals.

^ Boiling aqueous ammonia decomposes it slowly, with formation of chloride of ammonium

' and a daric brown oxide of cobalt

^ Concentrated solutions of luteo-cobaltic chloride and dichloride ofi^tinum, yield

orange-coloured needles of a chloroplatinate containing Go*Cl'.3PtCl'.6NH!'+8aq. ;

>■ dilute solutions deposit yellow neeoles of the same compound with 10} at. water ;

* these, according to i)ana, are monodinic combinations ooP . ooPoo . OP. Inclination
I- of ooP : ooP, in the dinodiagonal section, » 107^' 10'; OP : ooPoo - 1\4P 15'. The
^ crystals are often twins unitS hj the fiice OP. — Trichloride of gold forms with luteo-
f cobaltic chloride a yellow precipitate, consisting of small granular crystals, Co*Cl*.

• Aua».6NH».

' LuteO'Cohaltie iodide^ Oo'I'.dNH', is thrown down by iodide of potassium from

luteo-cobaltic solutions, as a yellow precipitate, nearly insoluble in cola water, mode-

'- rately soluble in hot water, and separating in brownish-yellow crystals on eyaporation.

The bromide is obtained in like manner as a deep yellow predpitate, in other respects

', resembling the iodide.

r Luieo^ohaltio cohaliieyanide (C6*Cy*)*.6NH*+JHK), is predpitated by co-

f balticyanide of potassium as a yellowish flesh-coloured precipitate composed of micro-

S scopic, oblique rhombic crystals. Ferricyanide of ^tassium forms an orange-yellow

t precipitate, exhibiting the same forms under the microscope.

t Luteo^ohaltio oxide, — By decomposing the sulphate with baryta-water, a

t brownish-yellow alkaline solution is formed, which absorbs carbonic add from the

air, and is decomposed by eyaporation, with evolution of ammonia and deposition of a
\ black powder.

' Lutio^obaltie nitrate, Co*(KO')'.6NH', separates from an oxidised solution of

' ammonio-cobaltous nitrate in orange-coloured crystalline laminae, the supernatant

I liquor being usually red and containing roseo-cobaltic nitrate. The sal^ purified

i by recrystallisation, forms crystals belonging to the dimetric system, with the faces

I P . 8P . OP. Angle of P : P in the lateral edges - llO^' 20'; of 3P : 8Pin the same

I - 16S^ 62'. Le^h of prindpal axis for P » 1*0161.

Carbonate8.~-Th^ neutral earbonaU, probably Co\CO*)M2KH*+7H'0, is ob-
tained bj decomposing a solution of the chloride with carbonate of silyer, and leaying
i. the liqmd to eyaporat^ in rhombic crystals, ooP. oof^ao .Foe IndinationofoDP: ooP

-i 116^ 50'; I>ao : f oo on the prinapal axis » lli^ 16'. If the air has had access to
the solution, the cxyiBtals are generally mixed with those of the add salt. The acid
carbonate, (C6')'^H&0'.6yH' + f aq., separates, on passing carbonic add gas into the
solution of Uie neutral salt» in large brown-red crystals, which, according to Dana, are
monodinic combinations, as P . opPqo . [ooPoo]. OP. —P. +2Pao, Inclination of

1056

COBALT-BASES, AMMONIACAL.

ooP : ooP, in thedinodiAgonal seetioii, « Sd^fiV; OP : a»P - 102O W; OP : a>P«
- 71° 44'; OP : -P - 189® 60'; ooP : +2Pae> <- llio 46'.

Oxalates, — ^The neutral oxalate is thrown down "bj oxalate of mnmonift, as a nddlrii*
yellow precipitate oomposed of alender needles, insoluble in water, easily sdnfale ia
oxalic acid, and sepawtting therefrom in wine-yellow, efflorescent, prismatic ayatak^
containing Co*(CK)V*^217&* + 4H*0. The acid oxalate was not obtained.

Luteo-eobaltie sulphate is obtained, mixed with the chloride, when an anmio-
niacal solution of oobaltons sulphate and chloride mixed with a large excess of eoarady
pulverised sal-ammoniac, is left exposed to the air. The crystalline mass deposited aitibe
bottom of the Teesel is dissolved in hot water ; the filtrate is acidulated with a few drofs
of sulphuric acid and treated with sulphate of silver ; and the liq[uid, after filtration and
oonoentiation, is left to czystalliseu The salt is also (though not constant^) ptrodneed by
the action of strong ammonia on roseo-cobaltie sulphate^ the dian^ oonaistiiig ausply
in the assumption ^ 1 at NH" : also as a product <tf the deoompositiaii of roseo-cobakie
sulphate (a salt of another base, not yet mrther examined, called by Oenth and GiUs
praveo-cobalt, being sometimes formed simultaneously). The wino-yellow ctystab of
luteo-oobaltic sulphate contain Co\SO«)'.12NH' + 6HH), and siTe (rff 4 at water in d^
air, or in vacuo. According to Dana, they are trimetrie combinationB, a»P . OP . fP .
IP . Sl^oo . I>ao ; also with SPoo or ool^f . Poo . ZPoo ; also with OP and ^oo. In-
clination of ooP : ooP h. 113<' 38' and 66<> 22'; ooPf : oo^ » S99 44' and 91^ 16*;
P 00 ;f» 00, on the principal axis - 112^8'; Poo :Pao, also on the same — 88^22*;
Luteo-oobaltic sulphate is isomorphous with the chloride, and the two salts axe capable
of crystallising together in all proportions.

Luteo-cobaltio ohromate, obtained by precipitation (pure only from the nitrate),
is yellow, soluble in hot water, and separates therefrom in yellow crystak. This aak
^80 crystallises in all proportions with the chloride. (Gib bs and Genth.)

AxxoNio-PBBOOB^LTio Salts, or OxTCOBALTio Salts. Frimy (leceit^y
—These salts contain 5 at ammonia associated with a basic salt of dioxide of cobalt
Thus, the nitrate is Co»0«.NK>».6NH«. + H«0, and the stUpkate, CoK)«J30».5NH» + |HK).
They are produced by the action of the air on concentrated solutions of ammooio-
cobidtous salts. They have ^nerally an olive-brown ccdour ; OTstallise well, are but
slightlv soluble in the ammomacal liquid, and are decomposed by water, especially when
hot "With, evolution of oxygen, liberation of ammonia, and separation of a green basic
salt containing the oxide Oo*0^ The nitrate of this group was first prepared, thoqgh
not analysed, bv L. Gmelin. (Handbook^ v. 342.)

The oxyoobaltic salts may be supposed to contain the diatomic base^ GoK), tfans:

The mYrfl<fl -. (^^}o».6NH»

General formndm of the Ammomacal Cobalt-oompownds, — These compounds may bs^
represented as ammonium-salts, in which part of the hydrogen in one or more moleedea
of NH* is replaced by ammonium itseb^ and another portion, in the ammonio-cobaltous
salts, by the monatomic radicle Go' «* 29*5 ; in the ammonio-cobaltic salts by the tri-
atomic radicle Ceo"* « Co" » 69 ; and in the ammonio-percobaltic salts, by the
diatomic radicle (CcoO)" -■ 75. Such fbrmuhn have been proposed by WeltsicB
(Ann. Ch. Pharm. xcviL 19), and H. Schiff (Compt rend. liu. 411).

In the following formuls, which are nearly the same as those of Schif!^ the symbol
Am stands for NH* and X for a monatomic add radicle, such as nitryl, NO^

0*.5NH».

a. Biammonio-cobaltoos salts .... « N(Co'AmH«)j^

/I .Triammonio-cobaltons salts

..... N(Oo'Am^JQ

7. Pentammonio-pert»baltic salts (oxyoobaltic salts) - N»[(CcoO)''Am»ff]

d. Tetrammonio-oobaltic salts (fbsco-cobaltie salts) - ^^^""^^lo*
c. Pentammonio-cobaltic salts:

Diacid, or Pnrpureo-cobaltie •

Triadd, or Boseo-cobaltic • •

C Xantho-cobaltio salts

If. Hexammonio-cobaltio salts (luteo-cobaltic salts)

o«

N«(Cco"'Am«Hn)^

N»(Coo"'Am«H')>^

_ N»[Cco-Am«H«(NO)]|0,

^ NXCco'"Am«H«)>Q,

COBALT-BLOOM ^ COB ALTINE. 1057

Some of these formulae, riz. those of the fuaco-, porpiireo-, and zantho-cobaltic salts,
differ by 1 at. H from those preyiously given ; but in compounds of such complexity,
the question of 1 atom of hydrogen more or less can scarcely be decided by analysis.

The formulsB of the chlorides and ozychloiides are deduced from those in the table
by substituting 1 or more at. CI for a corresponding number of atoms of XO.

The salts fi are transformed, by the joint action of ammonia and oxrgen into y,
and these, bv f^irther oxidation, are resolved into ammonia and the salts 8, which
again, by addition of 1 at NH' are transformed into c ; and these last, by the further
action of ammonia, yield i|. The salts ( are formed by the action of nitrous acid on
c, and are reoonverted into the diacid salts «, with evolution of nitric oxide, by the
action of strong acids.

For Weltzien's formulae, see Graham** EkmenU of ChtmiBtry, 2nd edition, ii 721.
G-ibbs and Genth object to the representation of these compounds as ammonium-salts,
and express their composition by means of formulas involving so-called conjugate
radicles, such as 6NH*':X)o' in the luteo-cobaltic salts, and KO'^6NH*^Go^ in the
xantho-cobaltic salts. It is not easy to say what is gained by such a mode of repre-
sentation.

COBA&T-B&OOM. Erythrine, Prismatic Red Cobalt, Red Cobalt- Ochre, Cobalt-
mica, KobaU-bluthe,—lL hydrated arsenate of cobalt, Co'AsO* + 4H*0, otZCoOjLbO^
•t- %H0, occurring in monoclinic crystals, in which the orthodiagonal, dinodiagonal, and

faces QoPaoand + Pa»are vertically striated. It is likewise found in glo-
bular and vermiform masses ; also pulverulent, incrustisg. Speeiflc gravity « 2*948.
Hardness, 1-6— 2-6, least on [^ooPoo]. Lustre on [ ooP oo ] pearly ; on the other
faces, adamantine inclining to vitreous. Colour, red of various shades, grey and green ;
the red tints incline to blue when viewed at right angles to dearage. Streak, peach-
blossom red. Sectiie. Flexible in thin plates.
Analyses of cobalt-bloom ftom Sehneeberg by Kazsten (Pogg. Ann. Ix. 261), gave

A8«0» Co»0 FeK) Ca«0 H«0

38-43 86-62 101 — 2410 - 10006

38-30 83-42 401 — 2408 - 99*81

3810 29-19 — 800 23*90 - 9919

The formula requires 88*43 AsH>», 37*63 Co*0, and 2402 water.

The mineral, when heated in a tube, yields water and turns blue if pure, ^re«i if it
contains nickel or iron. Before the blowpipe, on charcoal, it gives an arsenical odour
and melts in the inner flame to a dark grey bead of arsenical cobalt; gives with fluxes
the usual cobalt reaction. Dissolves easily in acids.

Earthy cobalt-blown (Kobalt-beachlag), of peach-blossom colour, is arsenate of
cobalt with free arsenious acid. A specimen from Sehneeberg analysed by Karst^n
gave 61-00 per cent. As«0«, 1910 As'O*, 16*60 Co»0, 210 Fe«0, and 1190 water
(« 100*70), with traces of nickel, lime, and sulphuric i»eid. ,- ,, . mv

Cobalt-bloom occurs in minute crystals at Sehneeberg in Saxony, Saalfeld in ^u-
ringia, Riechelsdorf in Hessia, Wolfach and Wittichwi in Baden, and Modum in Nor-
way. The earthy varieties are found in Dauphinv, in Cornwall, and near Alston,
Cumberland. A green variety occurs at Flatten in Bohemia. The mineral is also
found at Prince's mine. Lake Superior, in ealcite. When abundant, it is used for
the manufacture of smalt (Dana, iL 407.)

OOBA&T-B&ua. A pigment of a fine blue colour, like that of ultramarine,
obtained by mixing the solution of a cobalt-salt, perfectiy free from iron and nickel,
with a solution of pure alum, precipitating with an alkaline carbonate, careftilly wash-
ing the precipitate, then drying and igniting it strongly. It is a compound of protoxide
of cobalt and alumina, and is used both as oil and water colour.

OOBA&T-0&A]f OS* See Cobaltdol

COBAIiT-OKSSV. Rinman't Green. - A permanent green pigment prepared
by precipitating a mixture of the sulphates of zinc and cobalt with carbonate of
sodium, and igniting the precipiUte after thorough washing ; -- or by mixing a solution
of nitrate of «>balt with oxide or nitrate of sine, then evaporating and igniting.

COBA&TXWB. Cobalt-glanee, Glanoe-eobalt, Saver-tokite cobalt, C^t ffrts,-^
A native sulpharsenide of cobalt, Co«AsS or CoAa . Co^, occurring in forms of the
recrular system, viz. the cube, octahedron, pentagonal, dodecahedron, and several com-
binations of these forms. Cleavage parallel to the cubic faces. Also massive, g»nulap
or compact Specific gravity - 6-6*8. Hardne«i - 6*6. Fracture imperfect, coa-

Vol. I. ' Y

a .

. 33-10

8-23

b .

. 29-77

6-38

c .

. 30-37

5-76

d .

. 32-03

4-56

« .

. 32-60

3-47

/ .

. 8-67

26*98

1910 » 100-00
19-76 = 10000
19-78 « 10000
20-68 =: 100-34

]058 COBALT-MICA— COBALT- YELLOW,

choidal, uneren. Opaque, with metallic Inatre. Colour silTer-white, indining to ooppo-
red, occasionally tarnished- Streak, greyish-black. Srittie.

Before the blowpipe, it gives off fames of arseDic and yields, after roastiiig, a doll
black feebly magnetic globule, which coburs borax blue. It dissolTes in waoi nitric
acid leaving a residue of arsenious acid.

Anali/9es. — a, from Skutterudby Stromeyer ; 6, from Siegen by Scbnnbel; e, from
Orowitza in the Banat by Huberdt ; </, from the same by Patera ; e, frx>m Skottemd by
Ebbinghaus ; /» from Siegen by Sehnabel {BammeUberg^s Mineralekemic, p. 60.)

As Sb S

43-46 . . 20-08 » 99*88
44-76
44 13
43-63
43-68
42-63 2-84 1998 ^ lOOHH)

The formula Co'AsS requires 36*6 Co, 46'2 As, and 19*3 S. In analysis /, three-
fourths of the cobalt is replaced by iron.

Cobaltine occurs in large splendid crystals atTunaberg, Hiddarhyttan, and Hokansbo
in Sweden, and at Skutterud in Norway. It is also found at Querbach in Silesia,
Siegen in Westphalia, and several localities in Cornwall. This species and smaltine
afford the greatest part of the smalt of commerce. The most productive mines are
those of Vena in Sweden. (Dana, iL 68.)

OOBA&T-MIOA. Syn. with Cob^lt-blook.

COBJL&T-mZTBB. See Cobalt, Sitlpeidbs of (p. 44).

COBA&T-VXTBZO&. Bieberite, Bed Cobalt, Bhodalose^—BySnt/edi native sul-
phate of cobalt, of somewhat variable constitution, found in stalactites, and crusts
investing other minerals, in the rubbish of old mines at Bieber near Hanan, and at
Leogang in Salzburg. It is translucent, with flesh-red or rose-red colour and vitreous
lustre. A specimen analysed bv Winkelblech (Ann. Ch. Pharm. xiii. 265), after
being freed by solution and filtration from admixed manganous arsenate, yielded
2905 SO*, 19-91 Co'O, 3*87 ^1^ and 46*83 water, agreeing nearly with the formula
(Co«Mg«).(SO«)*. + 28 aq.

C0BA&T*TB&Xi01V^. This compound, discovered by Saint- £v re in 1862
^Ann. Ch. Phys. [3] zxxviiL 177), and further examined by A. Stromeyer (Ann.
Ch. Pharm. zcvi, 218), is produced by the action of nitrite of potassium on cobaltous
salts. Saint-£vTe regards it as a compound of peroxide of nitrogen with cobaltovs
oxide and potash, CoO,K0.2NO* or CoKO.(NO»)«:

CoNO« + 2HN0» + 4KN0« - CoKO.(NO')« + 3KN0« + 2N0 + HK)

NUrateof Nitric Nitrite of Cobslt-yeUow. Nitrate of Nitric

cubalt. acid. putastium. potassium. oxiJe.

Stromeyer oi\ the other hand regards it as a basic potassio-cobaltic nitritei,

(NOV* )
Co^O*.SK0.6N0^, or /QL^nnt v* [ 0", on which supposition its formation may be re-
presented by the equation :

Nitrate of Nitrite of Cobalt- Nitrate of

coImU. potaMium. yeliow. potasaittin.

The compound is prepared : 1. By adding an alkaline solution of nitrite of potas-
sium (obtained by passing the nitrous vapours evolved frx^m a mixturo of nitrate of
potassium and starch into caustic potash) to an add solution of nitrate of cobalt. —
2. By adding potash, not in excess, to a solution of nitrate of cobalt, so as to throw down
a blue basic salt (p. 37), treating this with a slight excess of nitrite of potassium, and
adding nitric acid in a thin stream from a pipette. ~ 3. By treating nitrate of cobalt
with a slight excess of potash, so as to throw down the roee-colonred hydrate, and
passing nitric oxide gas into the mixture. — It forms a bright yellow crystalline porwder
composed of microscopic fonr-sided needles with pyramidal summits. It is insoluble
in cold wat^r, also in alcohol and ether, but when boiled with wat^r, it gradnallT
dissolves, with evolution of acid vapours, and the solution, if subsequently evapomtedr
yields a lemon-yellow salt of different composition. Nitric acid and hydrochloric acid
do not act upon it in the cold, but decompose it at the boiling heat, with evolution of
nitrous vapours. Sulphydric acid decomposes it veiy slowly, sulfide of ammonium
immediately forming black sulphide of cobalt; when heated, it assumes an onnge-

COCA — COCAINE. 1059

yiOlow colour, gires off water and afterwards nitrooa ftunea, and leaTes seaqnioxide of
^ cobalt mixed with nitrate of potaasium.

Cobalt-yellow forma an excellent pigment for artiatie purposes, haying a beautiful

colour, like that of sulphide of cadmium, great permanence, and mixing easily with
. other colours. Its formation affords also an excellent method of separating cobalt

;' from other metals, especially from nickel (p. 40).

'^ When a solution of lead is mixed with nitrite of potassium and acetie acid, the

* liquid assumes a yellow colour, but no precipitation takes place ; but on adding a
<K>balt-8alt, a yeHowiBh-green precipitate (brownish-black ana crystalline frt>m dilute

1: solutions) is formed, whose composition is that of ^e yellow cobalt-compound, haying

I, half the potassium replaced by lead. (Stromey er.)

COOA. The leayes of Erythroxyhn Coca^ a plant cultiyated in the mountainous
t: districts of Peru and Boliyia, and in some parts of Brasil, are extensiyely used by the

I: inhabitants of those countries, and of other parts of South America, for chewing like

!:, tobacco, for which purpose they are mixed with burnt Hme, or the ash of a peculiar

plant, the Chenopoditm Quinociy according to Niemann. They possess powernil tonic
' and aedatiye properties, and the practice of chewine them is said to giye great power

of enduring fatigue, eyen on a scanty supply of food ; but like the use of opium, it is
^ apt to become an indispensable necessity, and ultimately produces all the baneful

' effects of a narcotic poison, such as hallucinations and premature decay both of body

' and of mind. The use of coca is said topreyail among ten millions of people in South

^ America, the annual consumption amounting to thirty million pounds of the dxy leares.

Coca leayes do not long retain their actiyity ; indeed they are said to become useless

after a year's keeping.

Coca leayes contain, according to Niemann (Arch. Pharm. [2] ciii. 120 and 291),

a cxystallisable basic substance called co c a 'i n e, a yolatile odoriierous substance, a pecu-
1 Uar tannic acid, cocatannic acid, and a waxy body, coca-wax.

i The yolatile constituent of coca leayes has a strong tany, almost intoxicating odour.

\ On distilling the leayes with water a slightly turbid distillate is obtained, firom which

P no oil separates ; but on saturating it with common salt and redistilling, a yery small

I quantity of a white non-ciystalline substance is obtained, which is yolatile, fusible,

g bghter than water, and possesses in a yery high degree the o lour of the leayes.

g. Cocatannic acid remains in the aqueous decoction of the leayes after the cocaine

has been precipitated by carbonate of sodium, and is left as a brown-red amorphous

substance when the liquid is eyaporated. Its sdution is coloured deep brownish-green

• by ferric chloride, and is precipitated by tartar emetic, or solution of white of egg, but
' not by gelatin ; it reduces chloride of gold eyen in the cold.

I! Coca- wax is contained in the precipitate formed by lime in extract of coca leayes

> prepared with alcoholic sulphuric acid. It contains 80-2 per cent carbon and 13*4

hydrogen, agreeing with the formula C'H'H)', and witJi the composition of the wax
from grass, and of that frt>m SyritiffOy as determined by Mulder. If the precipitate be
exhausted with ether, the ether eyaporated, and the residue repeatedly boued with
alcohol, the solution on cooling deposits a wax, which is white, amorphous, yery friable,

. and becomes strongly electric by trituration. It is insoluble in water, dissolyes slowly

in boiling alcohol, easily in ether, sometimes, though rarely, remaining in a somewhat

I crystalline form when ue ethereal solution is eyaporated. It melts at 70® C, and de-

composes when heated. Aqueous alkalis do not act upon it, but melting hydrate of
potassium decomposes and mssolyes it.

The substance mixed with coca leayes, to render them fit for chewing, is called
Llipta. According to Niemann, it is the ash of Chenopodium Qmnoa, Gad eke found
it m 400 KH), 17-7 Na«0, 66 Mg«0, 02 Fe, 4-6 PK)*, 18 S0«, 2*5 CI, 67 8iO«
30 CO', 18'6 sand, 1*0 water, and a trace of organic matter. (Handw. d. Chem. iL
[2] 123.)

OOOAIVB. C|^'»NO« or (7«^»J^0«. (Niemann, Ann. Ch. Pharm. adv. 218.)
— An alkaloid obtained from coca leayes, resembling atropine in many of its properties.
Niemann assigns to it the formula C^H^NO*; but this is improbable, because the
sum of the atoms of H and N is an odd number.

Cocaine is prepared by digesting coca leayes with 85 per cent alcohol containing a
small quantity of sulphuric acid, mixing the expressed mass with milk of lime, neu-
tralisins the filtrate with sulphuric ad^ eyaporating off the alcohol, mixing the re-
sidue with water, precipitating the resulting yellow-brown solution with carbonate of
sodium, treating the brown precipitate of impure cocaine with ether, and eyaporating.
Cocaine then remains, partly amorphous, partly crystalline, and may be purified by re-
peated treatment with alcohol

Cocaine crystallises in small, colourless, inodorous prisms ; it has a slightly bitter
taste, and produces temporal^ insensibility on the part of the tongue with which it
comes in contact It is soluble in 704 pts. of water at 12® C, more soluble in alcohol,

3t2

1060 COCATANNIC ACID — COCHINEAL.

and still more in ether. It melts at 98^ C, and solidifies to a transparent mass, wlucb
grHdaally becomes white and crystalline. At a higher tempemtnre, a Tery smsU p(»^
tion appears to rolatilise undeoomposed, but the greater part is decomposed, yieldiiig
ammoniacal products. Cocaine dissolves without colour in strong nitric, hydrochkne,
and sulphuric acid, the last solution only becoming black when heated.

Cocaine is strongly alkaline ; it dissolves in dilute acids, and neutralises them oon-
pletely. Its salta do not crystallise readily, the hydrochlorate, however, more essilj
than the others. Solutions of cocame^salts yield with cau$tic alkaltM, a white preemi-
tate soluble only in a large excess of fixed alkali, more solnUe in ammonia. Csrot*
naif of sodium forms a precipitate insoluble in excess. OoHnmate of ammomMMf a
precipitate easily soluble in excess. Anid carbonate of pUa$nvm and jihotphaU of
sodium produce a red precipitate. Sid^hocyanids of potassium produces but a sligfat
turbidity ; picric acid forms a sulphur-yellow precipitate, which gradually aggregates
into resinous lumps ; tannic add, on addition of hydrochloric acid, forms fc white jnr
cipitate, which aggregates in a similar manner ; mereurie chloride and potassio-mer-
curie iodide produces white precipitates ; iodine-water a kermea-brown ; iodide uffUat-
sium containing iodine, a dark-brown precipitate ; trichloride of gold and dicUoridt of
platinum ^ield precipitates with the hydrochlorate ; protochloride of tin prodoeef a
white precipitate, even in slightly acid and dilute solutions.

In most of these reactions, cocaine closely resembles atropine (L 474) ; the lattov
however, is not precipitated by carbonate of ammonia, or in acid solutions by BtaimoiH
chloride ; the two bases differ also in their reactions with gold and platinum-satta^ ttd
in their melting points, that of cocaine being %^ C. higher than that of atropine.

Hydrochlorate of Coca'ine crystalHses in white slender needles, easily solablt
in ifater; it has a bitter taste and produces on the tongue the peculiar action of the
base itself^ but in a higher deme. The solution, even when veiy dilute, is neeipi-
tated by chloride of gold, yielding the compound C*«H"NO«.HCLAuCl', whidi tsp-
tallises from alcohol in gold-bellow scales or laminae. This gold-^alt melti vltn
heated, and then yields a subhmate of bensoie aeid, aifording a very ehancteriftie
reaction. The chloroplatinate as a yellow-brown floceulent pvaeipitBte^ whidi soqb
becomes ciystalline, and is nearly insoluble in hydrochloric aeid.

Acetate of Cocaine crystallises readily; the nt^ra^^ with difficulty. Tbeis'-
phate remains when its soluticn is evaporated, as a colourless Taniish-lil» maaa, wbieli
becomes crystalline after a while ; it is permanent in the air.

OOOATAJnno AOIS.— COCA-HTAZ. See Coca. (p. 63).

COOCXV. A peculiar nitrogenous substance existing, according to PeUetier and
Caventou, in cochineal, and forming, as it were, the flesh of the inseet ; it reaenUei
gelatin in some of its characters, albumin and fibrin in others^

OOCCnfXTau Haidinger^s name for the reddish-brown mineral, with adaiaaB
tine lustre, from Casas Viejas in Mexico, which Del Rio regards as mercuric iodida
It melts and sublimes with facility.

COOOSmrXC ACXB. a volatfle fatfy acid existing, according to Felletisr and
Caventou, in cochineaL

COCCnroanc ACZB. A derivative ofeuxanthlc add (p. 712).

COOOOS3BA VntZOXS. This plant contains a green oolouring matter difieiing
from chlorophyll (Salm-Horstmar, Fogg. Ann. xciv. 466; cxv. 176.)

OOCCOOWIC JLOXDm An acid contained, according to Gob el (Buehn. "Repei^
viii. 203), in the seeds of Daphne Gnidium. It is dissolved by water from the alco-
holic extract; crystallises in colourless, slightly acid prisms; does not precipitate lime'
water, or the solutions of chloride of barium, acetate of lead, or ferrous sulphate.

COCCOUITJk A name applied to certain granular varieties of augite.

OOOOOXiO&a WXraRA. The plant which yields American kina

OOCCVXiZW. Syn. with PlCBOToxnr.

OOOCir&ini ZHSXCUB. Grains of Paradise,— The fimt of the Coeeidvs suhr
rosus (Dec), Menispermum cocculus (Linn.), Anamirta cocculus (Wight and Ar-
nott). It possesses strong narcotic and poisonous properties, due to the presence of a
bitter substance, pier o toxin (C*H*0»), of which it contains about J^cf its ▼ei^*'
It is used to adulterate beer, and is sometimes thrown into water to intoxicate or kill
fish ; it is occasionally employed in medicine. (See Un^s Dictionary of Arts, Jftw-
factures and Mines, i. 786 ; also the article Bbkb in this Dictionary, L 537.)

OOOCVSZC ACl]>v C"H*0*, is the acid corresponding to nitrocoeeusie aei4
a product of the action of nitric acid on carmine (i. 804) ; it has not yet been obtained
in the separate state.

COCBZKBA&. CocheniUe, CoccioncUa.'^BevGaX insects of the genus Cooeut, es-
pecially the Coccus cacti or cochineal insect-, yield a splendid colouring matter, sztsn-

COCHINEAL. 1061

sirely used for dyemg and the preparation of piements. The cochineal insect liTee on
Tarioiu plants of the genns OpuniiOf especially on the nopal, Opuntia decumana,
O. cactus, and O. monacantka. It is a native of Mexico, bnt its cuItiYation has been
introduced into many other hot countries, namely, the West Indies, Teneriffe, Ma-
deira, Algeria, Jaya : in colder climates it does not thrire. The female insects only are
collected ; they are killed either by drying in the sun, on hot plates, or in stoves, or by
immersing them for a short time in hot water. The last method yields a cochineal of
somewhat red-brown aspect, whereas if the insects have been killed by drying, it has
more of a blackish or ash-grey colour, with a silvery surface ; the latter is preferred.
The diy cochineal is freed from dust and adhering impurity by shaking it in sacks ;
the fine dust is then removed by sifting, and the laiger and smaller lumps in the re-
maining mass are separately sorted.

Other species of coccus probably contain the same colouring matter, but in smaller
quanti^ and more contaminated with foreign substances.

Oochmeal occurs in commerce in nearly egg-shaped grains I or 2 lines long, somewhat
hollowed below and arched above, about 70,000 going to the pound. It is inodorous,
very friaUe, and contains within it a dark red granular mass, which yields a powder of
a fine deep red colour; it has a bitter, slightly astringent taste, and leaves but a small
qiiantity of ash when burnt. In water, it swells up considerably, the shape of the
insect and its three pairs of legs then becoming distinctly visible.

The first investigation of cochineal was made by John (Chemical Tables, 'p. 127),
who found in it 60 per cent, coccus-red (carmine), 10 waxy &t, 1*5 inorganic salts
(chlorides of potassium and ammonium, and phosphates of calcium, iron, and magnesium),
28*0 ammal matter, and 10*6 water. According; to PelletierandCaventou(Ann. Ch.
PhySk vii. 90; viii 255), it contains a peculiar nitrogenous matter, coccin ( p. 54),
which forms, as it were, the flesh of the insect^ and an acid, not examined, to which
ther give the name of coecinic acid.

The colouring matter of cochineal is carminie acid (i, 804).

The watery extract likewise contains a ciystallisable nitrogenous substance,
C*H"NO', homologous with tyrosine, (C"H'NO*), and very similar to it in appearance
and reactiona It remains in the aqueous decoction of cochineal after the carminie
acid has been precipitated by acidulated acetate of lead, and may be separated by re-
moving the excess of lead from the filtrate with sulphuretted hydr^^en, and evapo-
rating to a syrup ; it then separates in a crystalline mass, and an admtional quantity
may be obtained by further concentration. It is insoluble in alcohol and ether, soluble
without decomposition in hydrochloric add, decomposed by shong nitric acid, the
liquid yielding crystals of a new acid on evaporation ; hot utric acid produces a more
thorough decomposition, with separation of diarcoaL The chalky substance dissolves
in alkalis, and is separated therefrom by acids. It does not appear to form definite
compounds either with acids or with bases.

The mother-liquor from which the whole of the chalky substance has been removed,
dries up to a soft mass amounting to 10 or 12 per cent, of the cochineal ; part of this
mass is soluble in alcohol, the remainder in water.

Cochineal boiled with water yields a deep red liquid, which assumes a reddish-yel-
low colour when mixed with tincture of gaUs or with strong aeids, and a beautifril
violet with lime-ioater ; it is precipitated violet-blue by neutral acetate of lead^ brifffat
red by ammonia, dark black-brown hy ferric chloride ; olive-green by a larj^er quantity,
deep red by alum. After the cochmeal has been thoroughly boiled with water, a
brownish animal substance remains.

The red colour of cochineal is likewise extracted by alcohol.

The chief use of cochineal \a icft the preparation of carmine and carmine-lakes
(i. 804). It is likewise employed for dyeing wool and silk scarlet (the fabric beinff
steeped first in annotto, then in a decoction of cochineal containing cream of tartar and
stannoso-stannie chloride^ or crimson (cochineal with tartar and tin-salt). Cochi-
neal is likewise used for tne preparation of rouse, of painters' colours, and of red ink,
and for colouring tooth-powder, confectionery, Uqueurs, &c.

Cochineal vanes much in colouring power, according to its source and mode of
preparation. The relative Quantities of colouring matter in different samples may
be estimated approximately by the depth of colour of a solution obtained by heating
1 gramme of c(>chineal in the water-bath for an hour, with 1000 grammes of water
and 20 drops of a saturated solution of alum ; also b^ the depth of colour which the
same extract will impart to wooL Bobiquet estimated tne amount of colouring
matter by means of a graduated solution of chlorine ; Anthon by a graduated solution
of an alumina-salt

A better method is that of Penny, depending on the action of ferricyanide of
potassium. 1 gramme of cochineal is extracted with 50 cub. cent of dilute potash-
solution ; the extract is farther diluted with 100 cc. of cold water ; and the purple

1062

COCHINE AL-RED — COCHLE ARI A.

■olntioii thereby obtained is mixed, when oold, with a gradvated solntioii of ferricjuide
of potaninm (1 grm. of the salt to 200 cc of solution), till its colour changes to dark
brown. All Uiese methods yield only relative results for eomparins different sorts of
cochineal one with the other. (See Ur^9 Dietumary of Arts, Manu/aeh§m imd Mines,
I 786 ; Handw. d. Chem. 2*« AufL ii. [2] 127.)

OOCTSZraAX-XBA is properly carmine ; the same term is, howerer, applied to
a splendid red artificial colour, whidi contains a considerable quantity of arsenate of
aluminium, and is therefore highly poisonous.

COOXUlAXZJu Aeenus of cruciferous plants, including horse-radish and
seurTy -grass, distinguisned by their acridity, arising from the presence of Tolatilo
oils, similar to, or identical with, volatile oil of mustara. (sulphocyanate of allyl).

Cochlearia Armoraeia, Horu-raduh. — The volatQe oil of this plant, when
purified, is identical with oil of mustard. It appears to exist in the root rndy formed,
and may be obtdined by bruising the root to a pulp, and distilling it jmt ae. The
best mode of preparation, however, is to distil 3 pts. of the finely chopped root with
2 pts. water, in a glass vessel (if a copper still be used, onlj a small quantity of oil is
obtained, in consequence of the formation of metallic sulphide). 100 pts. of the root
thus treated yield about 0*05 pt of crude oil, which majr be purified by rectification
with water and drying over chloride of calcium. The purified oil is oolourlees or pale
yellow; has a density of 1*01 ; smells like oil of mustard, and contains 48*41 per. cent C,
and 6*26 H (sulphocyanate of allyl, C^* CNS, requires 48*49 C and 6*06 H).
The crude oil is light yellow, of the consistence of cinnamon-oil, heavier than water,
evi^rates quickly, has an intolerable odour of horse-radish, taates sweet at find;
afterwards sharp and burning, and inflames the lips and tongue. When kept under
water for a year, it disappears, and silvery needles are formed, which smell like horse-
radish, excite irritation m the throat, melt and volatilise when heated, and diasolve
but slowly in alcohoL Oil of horse-radish is decomposed by nitric add, sulphuric
add, and chlorine. It yields sinapoline with oxide ot lead, and thiosinnamine with
ammonia. It dissolves slightly in water, the solution farming a brown predpitate
with acetste of lead, black with nitrate of silver. It dissolves readily in aleoboL
(Gm. X. 65).

Cochlearia of/ieinalit. (hmmon scurvy yrass, — llie herb of this plant con-
tains 92*2 per cent water, and yields 1*6 per cent, ash, which, according to Geiseler,
is very rich in potash, but, according to Braconnot, contains soda. The base is partly
combined with nitric add and, aooording to Braconnot^ with an organic add resembling
malic add.

Oil of scurvy-grass, Oleum ooohlearim^ obtained by distniing the heri> with
water, is yellow, pungent, of specific gravity 0*942 (Geiseler), bouB between 156^
and 159^0. (Simon). It dissolves easily in alcohol, and the alcoholic solution,
Spiritus coehiearitB, may be obtained by distilling the braised herb with alcohoL
According to Geiseler (Arch. Pharm. cxlvii. 136, 257), the oil is an oinrsulphide of
allyl, CB^SOy and yields with ammonia a crystalline compound, &H^80JiB*.
[These formulie are doubtful.] The oil does not exist ready formed in the plant, but
IS produced by the action of myrosin in presence of water, on a peculiar substance exist-
ing therein. According toWinckler ( Jahrb. pr. Pharm. xviiL 319), this substance is
neutral, and is converted into the volatile oil by the joint action of myrosin and lime.

Scurvy-grass camphor, or Oochlearin, C7*J7'0'(?), is a czystalline substance
sometimes deposited from Sjnritua cochlearia^ and from the water which has been
distilled off the plant It forms small, nacreous, shining laminae or needles, having a
&int odour, and sharp aromatic taste. Specific gravity « 1*248. It melts at 46^ G.,
sublimes without alteration, dissolves lightly in pure watei; easily in water containii^
carbonate of potasdam, also in alcohol and ether. (M aurach, Bepert Pharm. xdx. 128.)

Cochlearia Drab a. Whitlow Pepperwort, yidda, by distillation with water, »
volatile oil, similar to that obtained ftom radish-seeds. (Pless, Ann. Ch.Pharm.lviii.40.)

Cochlearia angliea^ English ecwrvy-grau, — The fresh herb of this plant con-
tains, according to T. J. Herapath (Chem. Soc. Qu. J. ii. 4), 2*42 per cent ash ; the
diy herb. 21*1 per cent ash ; of whidi 781 per cent are soluble, aaa 21*9 per cent in-
soluble in water. 100 parts of the ash contain :

8ol%Me in Wetter.

Potash 01

Soda 7-7

Carbonic add (CO*) 3*6

Sulphuric add (SO*) 3*1

Chloride of sodium 63*6

InsolubU in Water,

Carbonate of calcium
Carbonate of magnedum
Phosphate of caldum .
Feme phosphate . . .
SiUca

7*2
1-3
10*3
0-6
2*5

COCHLEARIN— COCOA-NUT OIL, 1063

See GOCHLBABZA. OFnCXNAUS.

COCmo AOIB. Cocottearic acid. Cocylic acid. Cocontutalffsaure, A fatty

acid, or probably a mixture of acids, obtained from coooa-Dnt oiL

Bromeis (Ann. Ch. Fharm. xxxt. 277), by saponifyinpf cocoa-nut fat» decomposim?
the soap with an acid in the usnal way, pressing the resulting fatty add between paper
and recrystallising from alcohol, obtain^ a nearly inodorous fatty acid, which meftedat
35^0., solidified to a por^Uin-like mass translucent at the edges, and distilled without
decompositioa Saint-Evre (Ann. Ch. Phys. [3] xx. 95) decomposes the soda-soap
of cocoa-nut oil with acetate of lead ; exhausts the lead-soap with ether ; decomposes
the undissolved soap with an add ; and crystallises the fatty add from alcohol. From
a saturated solution in aqueous alcohol, it crystallises, on cooling, in needles; but
from a solution in strong alcohol, by eyaj^ration, in amorphous masses. It melts at
84*5^ C, and Tolatilises without decomposition only in a stream of gas.

Bromeis assiffned to his codnic add the formula C^if^O*, but his analysis, calculated
according to the more recently determined atomic weight of carbon (C= 6), gives
rather (^IP*0*, or C"H"0*. Heintz has since announced the separation of an acid
of the same composition from spermaceti. Fehling obtained from cocoa-nut oil an acid
resembling the add prepared by Bromeis in appearance and mdting point, and corre-
sponding/exaetly to the formula G'*H"0*.

Saint-Evre, on the other hand, assigned to the oodnic add which he obtained, the
formula C'^H'K)*, though it agrees veiy closely with that of Bromeis in the mdting
point ^^

Heints regards the add C^^H^* from cocoa-nut oil, and likewise that obtained by
himself from spermaceti, as a mixture, especially on account of its melting point, which
is lower than that of lauric add (C*'H*^0') ; whereas if it were really a definite add,
its melting point would be intermediate between those of lauric add (44^ C.) and
myristic acid, C"H"0« f 64*> C). He finds, indeed, that a mixture of 14 pts. lauric and
2 pts. myristic add melts at about 86^ C. Saint-Erre's formula, C'H'K)* is on this
account more probable.

Ooeinaie of barium^ crystallised from boiling alcohol, is, aceording to bromeis,
C"H»BaO«. CWn«<«<>/stfwr,0"H»AgO»(BromeisXC"H"AgO«(Saint-Evre), is
obtained by predpitation from alcohoUc solutions, in white flocks mdting at 56^0.
soluble in ether, sparingly soluble in alcohol.

CocinaU of ethyl, C»H»f C*H»)0« or C"H««((?H»)0«, obtained by pasdne hydro-
chloric acid gas into a hot aloobouc solution of codnic add, washing the product with
weak alkali, and drying oyer chloride of caldum, is a liquid haying a &int-yellow
colour, a very pungent <Kiour of apples, and a sweet mawkish taste.

OOCnnv. Godnate ofglyeeryl, — The name of the neutral fkt corresponding to
codnic acid. The separate identity of such a fat, like that of the add itself, must, for
the present be considered doubtfrd. Brandes (Ann. Oh. Fharm. xy. 115), by ex-
pressine the fat from cocoa-nuts, and Grystallising it repeatedly from. boOing alcohol,
obtained a snow-white laminar crystalline fat, of specific gravity 0-92 at 8^ C, less
soluble in pure than in common ether, soluble in 40 pts. absolute alcohol at 20^ C,
about 12 pts. at 44^ C, sparingly soluble in aqueous alcohol of 0*75 in the cold, more
soluble in the same when warm; crystallising on cooling; decomposed by dry dis-
tillation.

A product of the decompodtion of neutral oodnate of calcium,
consisting, according to Delffs(Fogg. Ann. Ixxxvi. 587), of C^'H^'O, and therefore
the acetone of Saint-Evre's codnic add G'^B^O*. When purified by reczystallisation
from boiling alcohol, it forms colourless, inodorous, tasteless laminse, melting at 38^ C.,
and boiling at a temperature beyond the range of the mercurial thermometer.

OOOOA*>WinF OUfc This oil or fat is obtained by pressure from, the fruit of
certain cocoa-palms, Cheognveifera, C, butyraeeOf &c., and is imported in large quantities
into Europe for the manufrcture of soap. It is whitish, of unctuous consistence^ with
a peculiar disagreeable odour of volatile fat^ adds, and a mild taste ; it mdts at 20^ G.,
dissolves with aid of heat in alcohol and ether, readily in oils^ both fixed and vohitile,
bensene, &c.

Gocoa-nut oil quiddy becomes randd, and is easily saponified. It is a mixture of
several glycerides, containing also free iaity adds. By saponification it yields botii
fixed and volatile fatty adds. The volatile adds, which may be separated by dis-
tilling the mixture of free fatty adds with water, consist chiefly of caprylic add mixed
with small quantities of caproic and caprie adds. The fixed fatty adds of cocoa-nut
oil are partly liquid at ordinary temperatures, partly solid. The former have not been
particukrlv examined ; of the latter, several may be isolated by crystallisation from
alcohol, via. lauric add, 0"H**0', which maybe obtained pure, with the mdting
pdnt 48^ 0., by fractional predpitation of the soda-soap (On a em an a, J. pr. Ghem.

1064 CODEINE.

Ixzzi 367) ; Uie add, C^EFO*, which was obtained finom the oil lay Saint'Erre. ar.d
C»«H"0* by Bromeis, (see Codxic Acid, p. 67); myriatic add, C**H*0*, lit.^-
wise eziats in oonaiderable qoanf ity in cocoa-nut oiL The add actoaJly obtained h^d
Yeiy nearly the composition of myriatic acid, and melted at 49^ C, the melting point of
the pnre add being 63*8° (Fehling, Ann. Ch. Pharm. liii. 899). Oorgey {ibid.
dv. 26) likewise found a fatty add, G**H**0', melting at 66'^ C^ which, from the <>x-
amination of the ailTer^salt, he regarded as a mixture of myristic and palmitic acids.
Fehling also fonndpore palmitic acid. Stearic acid is joobably paresent in small
quantity.

The solid fats of cocoarnut oil are separated from the more liquid fats by pttasme.
and used for the manu&cture of candles.

The solid fatty adds of coooa-nut oil are oonTerted, by prolonged treatment witb
nitric add, into a mixture of adds of the seriea OH^~^0*, yiz. anchoic, anberie.
pimelic, adipic, sucdnic add, and an oily mass containing nitzocapric and nitroeapiylie
acids.

OOBWOra. C*'H«NO' + HK) or C^H^NO^ + IHO.—Jl non-rolatQe oiganie base
contained in opium. It was discovered by Robiquet in 1832 (Ann. Ch. Phya. [2] LL
269), and has been further examined bv Conerbe {ibid, lix. 168), Regnanlt {Aid,
Ixriii. 136), Gregory (Ann. Ch. Pharm. xxvL 44). Will {ibid. 44i Gerhardt (Ker.
Scient x. 203 ; Traiti. iv. 40), and espedaUy by Anderson (Ed. Phil Trans, xx. [1] 67)u

Preparation. — 1. The aqueous inftuion of opium, eTaporated to a syrup, is mixed
with solution of chloride of caldum ; the mass is diluted with water ; the resulting
meconate of caldum is separated, washed several times with anall quantities of wat4»r
and pressed ; and the liquid thus obtained is evaporated, lumps of marble being thrown
into it to neutralise the free add. Fresh quantities of meconate of caldnm then
separate, and the decanted liquid, if left at rest, deposits oystals of hvdrochlarate of
morphine and hydroehlorate of codeine. These crystals are dissolved in water, and
the solution, after purification with animal charcoal, is predpitated by ammonia,
which separates the greater part of the morphine, leaving the codeine in scuntion. The
filtered bquid is evaporated over the water-bath to expel the excess of ammonia, tiie
morphine salt remaining in solution being at the same time predpitated ; the saline
solution is concentiatMl and predpitated by caustic potash ; and the predpitate of
codeine is washed, dried, and dissolved in ether, whence it is deposited in cxystala.
(Robiquet)

2. To obtain the whole of the codeine f^m the mother-liquor which remains after
the morphine has been removed bv precipitation with ammonia, as just described, it
is necessaiy to get rid of the sal-ammoniac with which it is mixed. This may be
effected by repeatedly conoentratinff the liquid — the greater part of the hydroehlorate
of codeine then separating out, while the sal-ammoniac remains dissolved — and decom-
posing the remaimng sal-ammoniac with caustic potash. By repeating the crystallisa-
tion a certain number of times, the hydroehlorate of codeine might be obtained quite
firee from sal-ammoniac; this, however, would occasion the loss of a oonsideraUe
quantity of codeine, inasmuch as the two hydrochlorates do not difier greatly in solu-
bility ; but if the czystalliBation be discontinued at an earlier stage, the ereater psit
of the sal-ammoniac may be removed without loss of oodeine. The crystau of hydro-
chlorate of oodeine are then to be dissolved in boiling water, and a strong solution of
caustic potash added in excess, which will predpitateSie oodeine, partly as an oQ which
graduallpr solidifies, partly in the crystalline state as the liquid cools. The mother-
liquor yields by evaporation a f^h crop of crystals of codeine, and lastly, alter redne-
tion to a verv small bulk, it becomes filled, on cooling, with long vaXkj needles of
morphine, which had been retained in solution by the excess of potash. (Anderson.)

3. Opium is exhausted with cold water, the morphine predpitated by ammonia, the
meconic add by chloride of caldum, and the colouring matter by snbaeetate of lead.
The liquid filtered teom the lead-predpitate'is freed frnn lead by sulphuric add and
filtered again ; the filtrate is mixed with excess of potash ; the mixture left to stand
in the air till carbonate of potasdum has lionned ; and the whole agitated with ether,
which extracts the eodeine. (Winckler, B^pert. Pharm. xliv. 469.)

4. Merck (Ann. Ch. Pharm. xL 279) predpttates the mixture of the hydrochlorates
of codeine and morphine with pure soda ; treats the predpitate with cold alcobcd ;
saturates the alcoholic solution with sulphnrie add ; removes the alcohol by distillation,
and adds cold water to the remaining liquid as long as it produces turbidity ; then
filters, evaporates to a syrup, and affitates ^e residue with excess of potash and with
ether. The eodeine dissolves in the ether and is deponted by spontaneous evapora-
tion ; it is finally treated with alcohol, to free it from an oily substance which prevents
CTfstallisation.

Pwifioaii<m,— Impart oystals of codeine are purified by dissolving them in hydro-
chloric add, boiling with animal charcoal, repredpitating with caustic potash, aad

CODEINE. 1065

'\^ finally dissolving the precipitate in ether containing water, in order to free the codeine

from the last trace of morphine ; the ether used mu8t> however, be fr«e from alcohol,
otherwise a sympj liquid remains, on eyaporation, which cannot be made to crystallise.
If anhydrous ether be used, the codeine dissolTes much more slowly (Handw. d. Chem.
ii [3] 136). 100 pounds of opium yield from 6 to 8 oz. of codeine ^Robiquet). The
proportion of codeine in opium is from ^ to ^ of that of the morphine. (Anderson.)

ProperUet. — Codeine oystallises from axm^drous ether in small anhydrous rect-
angular octahedrons, truncated and modified in rarious ways. From hydrated ether
or alcohol, and from water, it separates in hydrated ciystals of the trimetric system.
Those deposited from alcohol exhibit the combination ooP . OP . f oo . &ao ; those
from water, the combination ooP . ^ao . jf ao . Inclination of ooP : ooP a 87° 40';
too : OP = 141° 37'; J?oo : OP - 140° 23'; jPoo : OP - 167° 26'. Cleavage pa-
rallel to OP. (Kopp, KrystaUographU, 266.)

Codeine dissolves in water much more readily than moiphine, especially in boiling
water. 100 pts. of water at 16° C. dissolve 1'26 pts. codeine. When heated with a
quantity of water less than sufilcient to dissolve it| it melts to an oily mass, which
remains at the bottom of the liquid. It dissolves easily in alcohol and hydrated ether,
lees easily in anhydrous ether. The alcoholic solution deflects the plane of polarisation
of a luminous ray strongly to the left; [a] s — 118*2° ; acids have scarcely any effect
on the rotatoxy power.

Codeine is quite insoluble in potash; it dissolves in ammonia, but not to a greater
.extent than in pure water.

Anhydrous codeine contains :

Robiquet. Couerbe. lUgnault. Oragory. WtU. Andaraoo.

Cfffc

KlofrA

{memm.'S

(iiKm.)

(mean.)

c»» .

•

. 216

72*24

70-16

71-84

78^1

7805

73 27

72DI

H» .

•

. 21

ro2

7*68

7-87

ri9

7'2I

7*25

7*09

N .

. U

4-68

»-S6

4-88

4-89

4*80

o> .

•

299

1606
100 00

—

—•

—

The hydrated crystals contain, according to Gerhardt's analysis, 67'82 per cent. C,
and 7*46 H, agreeing nearly with the formula C<*H*'NO* 4- HK), which requires
68-13 Cy 7-26 Hi 4*41 N, and 20*21 0.

Codeine is a strong base, auickly restoring the blue colour of reddened litmus, and
precipitating the salts of leaa, iron, copper, cobalt, nickel, &c

In its action on the animal economy, codeine resembles morphine in many respects.
According to Bobiquet, doses of 0*02 to 0*03 grm. produce in 24 hours, especially in
excitable persons, a sensation of comfort and repose, and a refreshing sleep, whereas
dos^ of 0*16 to 0*12 grm. produce heavy sleep, with a feeling of intoxication after
wakinff— sometimes also nausea and Tomiting; more than 0*2 grm. cannot be taken
in 24 hours without danger of serious consequences.

Codeine is said to be sometimes adulterated with sugar-candy ; this impurity may
be detected by its greater solubility in water, its smaller solubility in alcohol, and its
rery different action on polarised linit. According to Bobiquet> a solution of 0*600 pprm.
pure codeine in 100 cub. cent, alconol of at least 66 per cent gives, for the transition
tint, a deflection of 11° to the left.

JkooTnponUoru. — 1. When codeine is dissolved in excess of tulphuHe acid of medium
strength, and the solution is digested in a sand-bath, it acquires a dark colour, and
after a while vields a precipitate with carbonate of sodium, which is not the case with
codeine-salts in their ordinary state. The precipitate thus Ibrmed consists of amor-
phous codeine, which, after washing wiui water, solution in alcohol, and precipi-
tation by water, forms a grey powder with more or less oreen reflection, insoluble in
water, Msily soluble in alcohol, and precipitated therefrom by ether. It melts at 100° C.
to a black resinous mass. It dissolres easity in acids, forming amorphous salts, which
dry up by evaporation to brown resins. If the action of the sulphuric acid on the
codeine be prolonged, a dark green substance is obtained.

2. Niiric aoidf according to its degree o^ concentration, forms with codeine either a
basylous nitro-eompeund (p. 61), or a yellow resin soluble in alkalis.

8. Chlorine and oramins form substitntion-prodttcts (p. 69).

4. Iodide of ethyl heated with codeine forms hydriodate of ethyl-codeine.

6. Codeine gently heated with hydrate of potaeeium^ yields several volatile alkalis,
vis. ammonia, methvlamine and tritylamine, in variable proportion, accordinff to the
maimer in which the process is conducted. A volatile crystalline base is likewise
produced in small quantity, and a brown or black substance remains.

Salts OF CoDiiKB. — Codeine is a mono-acid base, dissolving readily in acids,
and yielding for the most part crystaUiBable salts. They are very bitter, are not
reddened by nitric acid, and do not impart a blue colour to ferric salts. Pbtaah pre-

1066 CODEINE.

dpiUtcM codeine from their solationi; ammonia doei not precipitate them imme-
diAtely, bat gires riae, after some time, to the separation of small tnuuparent erystala
of codeine. Infunon of ffoU-nuis precipitates oodeine-ealtB immediately.
Chromate of Codeine is easily obtained in beautiful yellow needles.

Hydroeklorate of Codeine, C1'H:"N0*.HC1 + 2H*0.— A somewhat concentrated
solntion of codeine in hydrochloric add, solidifies completely on cooling; a more dilute
solution deposits radiate groups of short needl«^ exhibiting under the microooope the
form of prisms with four fiuses, terminated by dihedral summits. The crystals dissolve
in 20 pts. of water at 16-6^., and in less than their weight of boiling water. They
giye off^ of their water at 100^ 0., the remainder at 121^, part of the add, howerer,
goins off at the same time.

Chioro'^mraU of Codeine^ obtained by mixing the solutions of the component aalta,
is a reddish or light-brown predpitate, moderately soluble in hydrochloric add.

The Chloromereuraie is obtained in like manner, as a predpitate, soluble in b<n]ing
water and in alcohol, and deposited in stellate groups on cooling.

The ChloroplaHnate, C'H^'NO'.HCLPtCl* -i- 2H*0 separates on adding dichloride of
platinum to a moderately concentrated solution of hydxocblorate of codeine, as a light-
yellow powder, which, if left in the liquid or kept moist on the filter, gradusJly becomes
crystaUine, and of an oranee-red colour. From rery dilute solutions, the double salt
separates after some time in silky needles. It dissolves sparingly in cold water, and
is decomposed by boih'n^ witter. It gives off } of its water at 100° C, the rest at 120°,
with indpient decompositiozL

Hydriodate of Codeine, Ci'H**KO'.HI -i- HK).— Long thin needles, soluble in
about 60 pts. of cold water, much more soluble in boiling water. They do not give off
aoy water at 100° G.

Hydrocyanate of Codeine is unciystallisable. — The hydroferroeyanate, prodnced
by mixing the alcoholic solutions of codeine and hydroferrocyanie add, is a white
predpitate which orvstallises after a while in needles, and dissolves in excess of hydro-
ferrocyanie add. The hydroferricyanate produced by adding aqueous ferricyanide of
potassium to hydrochlorate of codeine, is a very unstable crystalline compound.

Nitrate of Codeine, C»H'>NO*.HNO*, is produced by slowly adding nitric add
of spedflc eraTity 1*06 to pulverised codeine, carefully avoiding an excess of the add,
which would produce decomposition. It dissolves easily in boiline water, and separates
on cooling in small prismatic ctystals. It melts at a moderate heat, and deeorapoaes
at a higher temperature, leaving a difficultly combustible charcoal

Oxalate of Codeine, 2C»H"K0«.H*C*0«+ 8HK), is deposited on cooline. from
a hot saturated solution in short prisms and sometimes in scales. It dias^^ree in
80 pts. water at 15*6° C, and in about half its weight of boiling water. It gives off its
water at 100°, tonis brown at about 121°, and decomposes completely at higher
temperatures.

Phoephate of Co deine, C'»H««NO«.H*PO* ■»• fBPO— A solution of ordinary phos-
phoric add saturated with pulverised coddne does not oystallise by concentration, but
on addition of strong alcohol immediately depodts scales or short prisms. It is very
soluble in water.

Other phosphates of codeine appear also to exist.

Sulphate of Codeine, 2C»H*«NO*.H»80« + 6H«0 (or C»B«N0^.BSO* + 5H0)
crystallises in radiate groups of long needles, er by spontaneous evaporation, in flattened
prisms. It dissolves in 30 pts. of cold water, and is very soluble in hot water,
when pure, it is neutral to test-paper ; but it is apt to retain a small quantity of add,
which may be separated by repeated crystallisation. The crystals belong to the tri-
metric system, oo P . I^oo . oo Peo . Inclination of oo F : oo P « 151° 12' ; oo Poo

too - 113° 45' ; too : 1 00 « 133° 3'; oot oo : ooP « 104° 24. Qeavage parallel
to ooPoo.

Sulphocyanate of Codeine. C>"H>*NO*.HCvS + ^IPO.-^Badiate needles melt-
ing at 100° C., giving off 2*45 per cent water (-> ) atw) at 100° C.
Tartrate of Codeine is uncrystallisable.

SubetitutUm-products of Codeine*

Bromooobbiks. 2Ci*H>*BrN0*«f 3HK) (Anderson ^.cil)— Prepared by add-
ing bromine-water in small sucoesnve portions to pulverised codeine. The codeine dis-
solves, and the solutum loses the colour of bromine but acquires a characteristic reddish
tint On adding ammonia, the whole of the bromooodeine is predpitated as a silver-
white powder, containing a small quantity of unaltered codeine. It may be obtained
pure by repeated washing with cold water, solution in hydrochloric add, predpitatioB
with ammonia and dystfldlisation from alcohol

CODEINE. 1067

Bromocodeine is nearly insoluble in cold water, rather more soluble in hot water,
whence it separates on cooling in small prisms with dihedral summits. It is nearly
insoluble also in ether, but dissolves easuy in alcohol, especially at the boiling heat.
Better crystals are obtained firom alcohol dQuted with an equal volume of water. The
crystals are always very small, but of dazzling whiteness. They give off their
water (6*66 per cent.) at 100^ C. The anhydrous base gives by analysis 57*44
per cent. C, 6*44 H, and 21*5 Br, the formula C"B:«BrNO», requiring 57*14 0, 5*29 H,
21*16 Br, 3*70 N, and 12*71 O.

Bromocodeine melts when heated, forming a colourless liquid, which decomposes at
a somewhat higher temperature. It dissolves in cold sulphuric acid, the solution be-
coming dark coloured when heated. It is attacked by nitric acid, but much less
quickly than codeine.

Hvdrobromaie of Bromocodeine, C"H"BrNO".HBr + H'O, forms small prisms,
sparingly soluble in cold water, very soluble in boiling water. It gives off its water at
100^ C. The hydrochlorate forms radiate needles, resembling hydrochlorate of codeine.
The chloroplaHnaU, C'»H»BrNO«.HCLPtCl« (at lOO® C), is precipitated as a pale-
yellow powder, insoluble in water and in alcohol (platinum, by analysis, 16*98 per
eent ; "bj calculation 16*89).

Tribromocodeine, C"H**Br*NO' (Anderson, loe. cit) — ^When bromocodeine is
subjected to the continued action of bromine-water in excess, a light-yellow precipitate
of hydrobromate of tribromocodeine is formed, which rediasolves at first, but becomes
permanent on farther addition of bromine. On leaving the liquid to itself for 24
hours and then adding more bromine, a fresh precipitate is formed, and this treatment
must be repeated day after day as long as any furUier precipitate is thrown down by
adding bromine. The yellow precipitate is then to be washed with cold water, and dis-
solved in hvdrochloric acid ; and the base precipitated by ammonia, purified by solu-
tion in alcohol, and precipitated hj water.

Tribromocodeine thus prepared is an amorphous bulky powder, grey when dry,
insoluble in water and ether, easily soluble in alcohol It dissolves somewhat sparingly
in cold, more easily in hot hydrochloric acid, a small portion however remaining un-
dissolved, apparently from partial decomposition. It turns brown when heated on
platinum-toil, and decomposes completely at its melting pointy leaving a very slowly
combustible charcoal.

Tribromocodeine is but a weak base ; its salts are all soluble in water and amor-
phous. The hydrobromate, 2C>^Hi*Br*NO*.8HBr, obtained as above, is a light-yellow
perfectly amorphous powder, sparingly soluble in cold, more soluble in hot water. The
cMoropUUnate, C»fl»»Br»NO».lICLPtCl» is obtained by predpiUtion, as a brown-
yellow powder, insoluble in water and in alcohol (platinum, oy analysis, 13*07 per
cent ; by calculation, 13*29).

Chlobocodbins, 2C»*H*C1N0* + 8H«0. (Anderson, loc, «'<.)— Dry codeine
treated with chlorine gas, yields a number of complex products, whidi have not been
examined. By passing chlorine into the aqueous solution of codeine, a nearly black liquid
is produced, from which ammonia throws down an amorphous resinous base. A more
definite reaction is obtained by treating codeine with cnlorate of potassium and hy-
drochloric acid. Finely pulverised cUorate of potassium is gradually added to a
solution of codeine in hydrochloric add at 65^ — 70'-' 0. till the hquid yields apredpi-
tate on addition of ammonia. Excess of ammonia is then added, which throws down
ehlorooodeine as a silver-white or generally somewhat yellowish crystalline powder,
while a reddish liquid remains, containing products of a ftuther decomposition. In
this process, the same precautions must be observed as in the preparation of nitro-
codeme (p. 62). The cnlorocodeine is freed fh)m a small quantity of nndecompoeed
codeine by solution in hydrochloric add, boiling with animal charcoal, predpitation
with ammonia, and crystallisation from a hot alcoholic solution.

Chlorocodeine resembles bromocodeine in most of its properties. It dissolves
sparingly in boiling water, and crystallises on cooling in small prisms, which appear
to be isomorphoos with the crystals of bromocodeine. It is very soluble in strong
alcohol, especially if hot ; sparingly soluble in ether. The crystals give off thdr
water (7*48 per cent.) at lOO^' C. The dried base gives by analysis 65*31 per cent C,
6*11 H, and 10*32 CI, the formula C'»H«C1N0« requiring 64*76 G, 6*99 H, 10*64 CI,
419 N, and 14*42 0.

CUorooodeine dissolves without alteration in strong sulphuric add ; but the solution
is carbonised by heat Nitric add also dissolves it, and the solution decomposes on
boiling, though, much less easily than that of codeine^ giving off nitrous gases and a
very pungent vapour.

The 9ali$ of ehlorooodeine resemble those of bromocodeine. The ehloroplo'
Unate is a pale yellow predpitate, which after drying at 200^ C. yields 18*29 per cent

__ M

■alnble in boiliDg w>t«i ind id ilcohoL

Ct&kocodbihi, C"H"NO*.Ct* (ADderion, loe. of.)— HiU compound, iriiicb u
not m mbstitation-fcodnct like tbs preceding bnt r&ther ± cj&uide of codeiae, i>
prodnead when trmogen g»a i» riowlj maaed mto » eoneentrttol ticoholic ■olotion. TIm
gu ia abnnduiUT absorbed, the liqud fint taming yellow, then brown ; the odoor of
ejumgHi endiullj disuqiein, and u replaced by tlut of hydnxTanic add ; and djatala
. an dfpo«t«l, eontiniullj increaniiig in qnutitj, as the pura^ of the gae ia ohi-
tinnHL The mother-tiquor B^nJated from the crjataJa yields an additional qoandtr
if again treated with cyuogen gaa. The crystals are washed with a amall qaantity of
aleobol, and disaoWed in a hot mistare of elher and alcohol, into which solnlioa
cyanogen is agun paand to tranifbrm any codeine that may have remained nnactrd
on. Cyanoeodeine then appant«a in thin, shining, colonrleaa or bintly yellow, ux-
■ided lamina. It diaaolvM eaailj in boiling abaolat« alcohol, or in a mixture of aieohol
and ether, aparingjy in water, more easily on addition of alcohol ; this solution how-
CTBT doe* not deposit anything when left at rest, and decompoeea bj erapcomtiiin,
leaiiog a reaidoe of codeine.

QyuocodeiM yield* by analysis es- 1 3 percent C, 6-05 H, and tl-66 N, ealcniatwn
reaniiii^ UST per cent C, M7 H, 11-68 IT, and 13-97 O.

fit is Hrlups a hjdra<7anate of eyanocodeine, C"H^I}yNO'.HCy,]

With MjfdmMorie aeid, it forms a eryatallisable sail, which bowerer quickly de-
eompoaea, giving off ammonia on addition of potash ; the hydrochloric add aalntion, if
left to stand fi» twenty-fbnr hooiB, gives off hydrocyanie acid. With exatic and ral-
pkurie adds, ^anocodeine fi>rms aparingly solnble salts which likewise decompose
quickly, giving off ammonia and hy^ocyanie add. (Anderson.)

BtHTLConniicm. C"H"NO' = CH^I^H-jNO*. (H. How. Chem. Sot Qn. J. vi.
125.) — The hydriodate of this bsse is obtained by endosiug in a sealed tube pnl-
verised codeine with a amatl quantity of iodide of ethyl and snfGdent abaolste
alcohol to dissolve the codeine, and heating the mixture in the water-bath for two
honra. On cooling, a oyEtalline mam is obtained, very soloble in cold water, whence
it ia deposited, after eoncectrstion, in tolts of fine needles. Dried at 100° C_ it
contains S2-6B per cent. C, 5'S7 H, and 27'E)1 I, agreeing nearly with the fbranila
C"H»NO«,HI, which requires 62-73 C, 5-76 H, and 27-83 L

The solntioQ is not [a«dpit«ted either b^ potash or by ammonia. .Treated with
oxide of silver, it yields a stioD^y alkaline liqnid which ahsorba carbonic add dniing
evaporation. The residue is again attacked by iodide of ethyl, but the reaction
appears to be very complicated.

loDocoDiiHB, C""H'"NO'.P. (Anderson, lee. ctt) — This enapoond — which
■honld rather be called iodide of codeine, for it is not a snbstitntion-ptidaet—is
prepared by dissolving equal weights of iodine and codeine in the smaHeEt passible
goautitiee of alcohol, mixing the si^ntions, and leaving Uie mixture at rest ; iodocodeine
is then deposited, after a longer or shorter time, accOTding to the ooueentration of the
Bolotions, in trian^nlar plates belonging to the tridinic system ; they have a line inW
colour by transmitted light deep violet by reflected light and if well iUmninate^
exhibit a beantiftal adamantine, nearly metallic lustra. They arc inaolnlile in water
and in ether, bnt dissolve in alcohol with red-brown ooloor. After dtying in vacno,
they contain, according to the mean of Anderaon's analyses, 33-07 per cent C, 3'3II
H. and fifi'SS I. the formula reqoiring 31-7fi C, 3-OS H, and 56 L

Iodocodeine gives off iodine at 100° C. It is dissolved t^ hot snlphoiic acid, and
slowly attacksd by hot nitric add. Boiling potash dissolvee out the iodine and Invea
codeine. With snlphnretted hydro^n, it yidds hydriodate of codeine, with dqmaitioB
of anlphnr. With nitrate of silveT, it forms an immediate [necipitate, which, however,
contain* only abont Jof the iodine in the compound. (Anderson, toe. eU.)

NiTBOCODBiHB. C''H"N»0' ^ C'^'^IIO^NO'. (Anderson,&c.n(.)— To[a*-
pare this base, dilute nitric add, of specific giKvity 1-060. is heated in a fl««fc to ■ tem-
perature short of ebullition, finely pulverised codeine is added, sod the mixture ia kept
at a gentJe heat for a few minot«, tills sample of it gives a predpitate with ammonia,
and tba quantity of this predpitate no longra increases after several trials. The whole
of the Bolotion ii then satnrated with ammonia and briskly agitatrf. whereby a thick
predpitate of nilrocodeine is formed. The action of the nitric add is very rapid, the
tnuidbnnation bdng complete in a few minntes, so that close watching is nrimwij to
■eiie the exact point at which the liqnid should be satutaled with ammonia. Evolu-
tion of red vapoius is a sign that the action has gone too br, and that a portion of the
codeine has l^n converted into a peculiar red mbetance, not yet examined. In this

COD-LIVER OIL —COFFEE. 1069

case, it is best to interrupt the procfss before the whole of the codeine is decomposed.
Strong nitric acid acts on codeine with Tiolenoe, producing a yellow resin.

Nitrocodeine precipitated by ammonia, as aboye, forms yery small silyeiy laminie,
sHffhtly tinged with yellow. It is purified from colouring matter and a little unaltered
codeine, bjr solution in hydrochloric acid, boilins with ammal charcoal, reprecipitation
by ammonia, and reciystallisation from dilute uoohol or ether-aloohoL From alcohol
it crystallises in thin xiky laminn of a pale tawny colour, forming, when dry, an inter-
laced silky mass. From ether^alcohol it separatai, by eyaporation, in small yellowish
crystals, exhibiting under the microscope tne form of quaarilateral prisms with dihe-
dral summits. It is sparingly soluble in boiling water, and separates in small crystals
on cooling. It dissolyes readily in boiling alcohol, sparingly in ether. It giyes hy
analysis 62*49— 6310 C, and 5*91—6*04 H, the formula requiring 62*79 C, and 6*81 H.

Nitrocodeine when cautiously heated melts to a yellow liquid, which solidifies to a
highly crystalline mass. At a higher temperature, it decomposes quickly, without
flame, leaving a bulky charcoal When the alcoholic solution of nitrocodeine is treated
with sulphide of ammonium at the heat of the water-bath, it acquires a dark colour
and deposits sulphur. When the action is complete, the filtered liquid yields with
ammonia a brown amorphous precipitate, which, after solution in hydrodbloric acid,
boiling with animal charcoal, and reprecipitation, forms a pale yellow basic substance
{azoo^Mne)^ which has not been fiirther examined.

Nitrocodeine dissolves in acids, forming salts which are neutral to test-papers, and
from which the base is precipitated as a crystalline powder by potash or ammonia.

The kydrochloTaU is obtained by eyaporation in the form of an unciystallisable
resinous mass. The ehloroplaHnate, C**H»(N0>)N0*.HCLPta'-i-2aq., is a yellow
precipitate, insoluble in water and in alcohol. It gives ofP its water at 100^ G., and
then yields by analysis 17*88 per cent. Pt (calc. 17*93).

The oxalate crystallises in short yellow prisms, yery soluble in water. The su^
pkatr, 2C'*H»(NO')NO'.H^80«-i-2aq. (at 100^ C), is obtained in radiate groups of
short pointed needles, neutral to test-paper, and yeiy soluble in boiling water.

OOB-&IvaK OZ&. See Oils, AmMix.

C<BXa8Tnr. 8r*S0* or SrO.SO^. — Native sulphate of strontium. This mineral
is so named ftom its occasional delicate blue colour ; though
it is frequently found of other shades, as white, greyish and r^l28.

yeUowiBn-white, and red. It occurs massive, and crystal-
lised, sometimes also in fibrous and stellated forms. It
belongs to the trimetric system, being isomorphous with
sulphate of barium and sulphate of cakium. ^e primary
form is a rhombic prism of 104^ 20* and 76^' 40'. An
ordinary combination is (oo . Poo i^«o^2 (fy, 128).
Cleavage very distinct parallel to r» ; less distinct
parallel to ^oo . It has a vitreous lustre, and is trans-
parent, translucent^ or opaque. It is very brittle. Specific gravity 8*963 (Breit-
haupt). Hardness 3 — 3*6. Before the blowpipe it foses to a white, opaque, friable
enameL Gcelestin occurs abundantly in the massive form at Montmaitre^ and near
Bristol The crystallised variety is found in the red sandstone at Inyemess, and in
many other localities. Splendid groups of crystals occur at GKrgenti in Sicily, mixed
with sulphur and gypsum. Fine specimens are also met with at Bex in Switserland,
Conil in Spain, BetzDanya in Hungary, in compact limestone near Lake Erie, and
many other localities. Cr}'vtals of (^estin are often found in which the strontium is
partially replaced by barium or calcium, the substitution being attended with a certain
alteration in the magnitude of the aneles of the crystaL The blue colouring of eesrtain
specimens of ocslestin appears to be due to the presence of small quantities of ferroso-
fecric phosphate. (Jahresber. d. Chem. 1847, 1219 ; 1849, 776 ; 1860, 767 ; 1863, 842 ;
1866, 970; 1866, 874; 1867, 692.— Dana, ii 368.)

0<B&OOUara »0&TOAm»A. The tree which yields the Abeooouta bark of
West Africa, where it is used for colouring skins, mats, &c. ; also as a local appli-
cation for ulcers. According to Stenhouse, the bark contains berberine.

OOBBmuO JLOZB. According to Vlaanderen and Mulder (Jahresb. d.
Chem. 1868, p. 262), caffeic or cafietannic acid (I 709), which they regard as C'«Hi<0',
yields by oxidation, cqfeame add, C^^H^'O*, and from this, by the action of air and
ammonia, are pzoduced a-emrulie add, CH"0*, and 0-^€frulie add, C**H**0*, both of
which form blue salts, and consequently resemble viridic add (q, v.)

OIBRUUnr. A name sometimes applied to the body C*H"NO, supposed to exist
in sulphindigotie add, CH»NO.SO'.

COnaa. Cqfi, Kaffee. — Coffee beans are the seed of Cc^fea arabica, a tree of the
mbiaoeous order, indigenous in southern Abyssinia. It is said to have been transpUmtod

The ned> ue wptraUd from the wift pods bj braising with a hvarj idHt, tfaeii Wkihed
Bad dried, and UbU; freed trom their parchmeDt'lika eoatlnE bj- punng them under a
Toodeu edgfr-vheel, aad rabeeqneDtlj vinnowing. Id thii stale thej are wnt to
Eorope.

Tlie moat hig^^MtMmedmietjiitlieHocha coffee, which ii grown in the proriiKS
of Yemen in ArBbia: it bos ■ mora agreeable taate and amell than aD7 other kind, and
ia diatingoiabed bj ita jellow- colonr and the compatatiTa amallneaa and nmndneai of
the bean. Kext to it in Eoropean repntation, ara the Haitioiqiu and Booibon
cofTeea ; the fomer ia largei than the Arabian aad more oblong ; it la rotinded at the
ends, of greeaiah colonr, and almost alwaja retaina a ailTer^iTej pHii-l- which eomea
off io roaBting. The Boorbon coffse approaches nearest to the Moeha, from vfaieh it
oiiginallj ^tmiig. The Saint Domingo coffee, which haa ita two extnoniliea pointed, ia
uneh less esteemed than the preceding.

The chemical piopertiee and composition of esiSet beana have been made the nlgeet
of nomeroDi inTestigatioM. Schroeder in 180B (Gwhlei's J. Chem. Phja. n. 6M),
shoved that thaj contain ht,raidD, macua, eitiactiTe matter, &«., aad that the aqneona
(ntract is coloiued graen by ferroso-ibrnc salts, and jields a graen precipitate with
copper-aaltB on addition of an alkali — Range in 1830 (l\falenlun rur P^tialaf^
Lief L p. H6) discovered caffeine: and Pfaff (%tt. <{. Materia Mediae^ ia.i)loaai
in the beans, in addition to thia sabstance, two adcb, via. caffeic and caffetannie
acids, which, bowerer, were afterwards shown bj Bochleder to be identicaL The
examination of coffee-beans was farther carried ont bj Koblqnet and Bontron
(J. Pharm. iiiii. 101), who found, in addition to fat, extractire matter, and cafleii

raiying

legnmin, and a ven small qoantity of citric acid (a few grains io a poond of
coffee);— afterwards % Payen (Ann. Ch. Fhys. [3] zztL 108), tod Bibra {S*r-
kolucke Genuumittel, u. s. w. Nnnberg, 1B6G), andlastl; b; Qraham, Btenfaoase,
and Campbell (Cbem. Soc Q<l J. iz. 33). According to Payen, the caS^e exists
parOy in the free state, partly aa caffetannate ot caffeine and potanEiom (a new conai-
dered aa donbtful by Qnham, Stcnhooae, and Campbell). Payen also {bond anirar
in the nnroaated beana. According to Qraham, Stenhouse, and Campbell, the ni
beans contain, partly cane-sngar, partly another kind of sugar, probably u
nation aa a glacoside, the total amonnt of sugar in variona kinds of ooflee
from 6*0 to 7'5 percent. The caff eioe amonnls Io IT) percent, according to Payen;
from 0*5 to I'D according to Qraham, Steiihouae, and Campbell. The amoont of
fat appears to vary conaiderably. According to Rochleder, the beans contain cJein
and palmitin, perhaps alao laorostearin. Kobiquet and Bontron found in 8 pta. of
Marbniqne eoffe^ 1 pt. of fat Payen found thai Mocha coffee contains abont 13 per
cent of fai^ whiiih is rather greater than the proportion in Maitiniqne coffee. The
fal of Mocha coffee also retains the odoriferaus pnndpls more tenacioualy than that of
other Tarieties; it ia yellowiah, very fluid, and separates on) j into two portions of
different melting points, whereas that of Martinique coffee has a more browDish colosr,
is less fluid, and may be separated into at least four distinct fata, melting at about
5", 20°, eO°, and 90° C. le^ectiTely, the laat being a kind of Tcgetable wax. Ac-
cording to Stenhonse, coffee beans contain about 12 per oenti of faL A«oording to
Vogel, beniens extracts from them 18 per cent of aolubde matter.

The following is the aTcrage oompositiou of raw coffee beans, aa determined by
Payen and Ton Bibra : —

CeUuIose 34

Glucose, dextrin, and o^;aDic

L^;iimin and Casein ,
Other uitrogeuoua substancM .
Caffeine (free) ....
Caffbtannate of caffeine and

pctassiam . ' , 3fi to 60

Tiscid eesential oil (inaoluble

ia water) .... 0-001
Aromatie oils, some lighter,

others heavier than water . 0-003

Substances precipitable by
nentral acetate of lead . 7 to B

Precipitable by baale ace-
tate of lead . . 6 to 6

COFFEE.

1071

Leyi (Ann. Ch. Fhann. 1. 421) found 3*2 per cent, ash.— T. J. Herapath (Ghem.
Qaz. 1848, p. 159) found 6*7 per cent in the oiy beans. Vogel found 3*5 percent aah,
of which 0*80 waa soluble in water.

(hmjposUion of ihe Ash of Coffee-^teans in 100 parts.

Orahan, Stenhottia, and Campbell.

Fbtaah . . .

Uri.

Herapath.

CeyloD
cult.

Cerloa
wUd.

Jara.

Coata
Rica.

Jaaaica.

Mocha.

Nell-
gheny.

60^

lG-5

»l

64*0

tt-8

«-7

•1-6

itr%

Soda ....

14*8

7-1

Lime . . • .

«7-7

4«1

4-6

4-1

4-6

8-9

6-7

MagnMla . .

10-9

5*9

8*9

8-5

8-ft

Ferric oxide .

0-98

0-73

0-63

0-44

044

0-61

Salpharie acid

anhydrous .

trace.

1-S

S«

4*5

B'S

»8

3-1

5-9

8-1

Carbonic acid

anhrdroot .
Ph'««pnorlc

17-5

16*9

18-1

16*9

16*4

17-0

14-9

addanhjrdroitf

13*6

40-7

10>3

11*6

11-0

10-8

111

10*1

108

Chlorine. . .

1*2

0-4

0-5

1-0

0-7

0-6

Silica. . . .

3-6

From the analysis of the six yarieties by Gbaham, Stenhouse, and Campbell, which
exhibit a remarkably close agreement, it appears that oo£fee>a8h is especially distin-
guished by the absence of sooa and silica. The soda found by "Leevi is doubtful, and
Herapath s results, which differ enormously from all Che rest^ may be rejected as un-
trustworthy.

Boasting Coffes. — Coffee-beans, when heated or roasted, assume a light brown, chest-
nut-brown, or even black colour, according to the degree of heat applied. The air-
dried beans diminish in weight during roasting by 15 or 25 per cent, bat increase
considerably in Tolume, the increase amountino, aocordins to t. ^ibra» to from 50 to 58
per cent, if they haye been preTiously washed, or if they are strongly heated. Ac-
cording to Payen, 100 grms. of raw coffee-beans yield 50 grms. of roasted beans, and
100 T(M8. of the beans increase by roasting to 130 toIs. To roast the beans with peifect
regularitr, it is best to steep them in water for ten or twelye minutes, then to cby
them lightly, after draining, and roast them immediately. The steeping removes im-
purities, and perhaps also serves to impart to the beans a uniform amount of water, so
that they get more regularly heated.

The vessels used for roasting coffee are generally of iron : recently silver and glass
vessels have also been used for the purpose. The cnief point to be attended to in their
construction and use, is to ensure that the heat be sradual and not too strong. If the
beans are heated above the temperature required to brown them, they swell up strongly,
turn black, and ultimately become carbonised. (See XJr^s JHctionaty of Arts, Manw-
factureSf and Mines, L 794.)

By heating coffee-beans in a retort with proper condensing fl{>paiatus, the following
volatile products are successively obtained (v. Bibra) :

1. A volatile oil, pre-existing in the raw beans, and little^ or not at all altered by
heat

2. Volatile oil having the odour of roasted coffee.

3. Empyreumatic oiL

4. A &tty body.

5. Acetic acid.

6. A small quantity of caffeine, together with an aromatic body, probably aimflmaT
(i. 428).

7. Humoid substances, and one or more compounds which easily reduce gold and
silver-salts.

The statement of Bochleder that pyrocatechin is formed in the distillation (from
the caffetannic acid), is not confirmed by the observations of Graham, Stenhouse^ and
Campbell.

The composition of roasted coffee has been investigated by Payen, by v. Bibra» and
by Graham, Stenhouse, and Campbell Payen exhausted 100 grms. of ground coffee
with a litre of boiling water ; heated the filtrate in a distillatoiy aoparatus for two
hours, by which time it had quite lost its odour ; and collected the oistillate in four
conaected receivers^ the first of which gradually became heated to about 90^ C, while
the second was kept between 25° and 30°, and the third and fourth were cooled to 0°,
or a little below, the vapours which escaped from the fourth being passed through
strong sulphuric add, or through a tube fiUed with red-hot oxide of copper.

1072 COFFER

In the first reoeiyer, a jellowijBh water coUeeted, and a fev drops of oil, amomating
to about ^ of the infiuion, floated on the snrfaoe, quite destitute of feignnoe. Hie
liquid oondensed in the second receiver amounted to about ^ of the volume of the in-
fusion : a few drops of an odourless fixed oil floated on the top of the watery liquid,
which possessed the firafl;rant odour of coffee in so high a degree that a few dr^ of it
sufficed to impart the odour to a cup of milk. The water of this second reoeirer oon-
tained the principal part of the coffee-aroma, concentrated about 10€ timesL On agi-
tating the water with about { of its Tolume of ether, repeating this fzeatment serenl
times, and then evaporating the ether, there remained a yellowish oil (aboot O"! grm.
from 10 grms.), the yezy strong odour of which resemblea that of -the aioma connmooi
to the several varieties of coffee. Another oil, somewhat more volatile, and of man
delicate aromatic odour, remained, together with a little ether, in the water : this cSk
appears to be contained especially in the finer kinds of coffee, as that of Moeha.

To obtain the whole of the oils from the infusion of coffee, lumps of chloride of
calcium are introduced into the first two receivers during the distillation ; the third
receiver is connected with a chloride-of-calcium-tube and cooled to + 2(JP C. A solu-
tion of chloride of calcium is then obtained, containing the whole of the volatQe cofiee-
oil, which may be extracted from it by agitation with ether. Payen obtained from
10,000 pts. of coffee only 2 pts. of this o^ but possessing so strong an odour that a
single drop sufficed to fill a whole room with the characteristic odour of oofifba

fi the third receiver be cooled to —2^ or —3^ C. during the distillation, a fisw drops
of liquid collect in it having the odour of coffee, but likewise the less agreeable odour of
empyreumatic hydrocarbons, which are present in greater quantity in proportion ss the
coffee has been more strongly roasted. The odour of these bodies is peroepdble also
in the fourth receiver and m the vapours which escape therefrom, these vapours like-
wise imparting a brown colour ^o oil of vitriol.

According to Zenneck, the aroma of coffee is obtained in larger quantity by adding
sulphuric acid to the liquid in the retort

Yon Bibra, by exhausting roasted coffee-beans with ether, obtained from Mocha eol&e
8*8 to 9*3 per cent, fatty matter; from Java ooffise 8-9 to 9*2 per cent He suppoaes
that tlus fat is for the most part produced during the roasting; inasmuch as the raw
beans yielded only from 4 to 6 per cent of tat ; and, if the beans thus exhausted were
subsequently roasted, they yielded an additional 4 to 6 per cent fat on being again
treated with ether. It is possible, however, that the frt in the raw bean is encLowd
in cells, and does not become accessible to the ether till the envelopes are burst by the
heat

The fat extracted by ether has the consistence of cacao-butter (L 699), and ezhaki
the peculiar aroma of coffee, which appears to be produced from the volatile oil of the
raw Deans by roasting ; by boiling the fat with water this aroma is driven off The
fat is a mixture of several substances, some of which are likewise soluble in aloohoL
It appears to contain olein and palmitin, together with a resin and a hydrocarbon ;
perhaps also other bodies. The ethereal extract likewise contains the whole of the
caffeine, and a body which colours iron-salts greenish, precipitates lead-salts, and re-
duces gold and silver-salts.

When ground coffee which has been exhausted with ether, is twice heated with
boiling water, after drying, a dark brown, strongly acid liquid is obtained, having a
very bitter taste, but without the peculiar agreeable fiavour of cofiee. The aqueous
extract likewise contains sugar, humoid substances, assamar, and tannic add, nearly
identical with caffetannic acid ; also a substance which reduces gold- and silver-salts,
a small quantity of empyreumatic oU, salts, and indifierent substances insoluble in
alcohol The brown bitter products in roasted coffee appear to be produced chiefly
from the sugar, inasmuch as that substance diminishes greatly in quantity, or disap-
pears altogether, in the roasting process. Grabim, Stenhouse and Campbell found
that, whilst the raw beans contained 6*7 to 7*8 per cent, sugar, the roasted beans never
contained more than 1*1 per cent, and in many instances none at all.

The residue, after extraction with ether and water, yielded by boilins with water
containing carbonate of sodium, a solution coloured deep brown by humoid substances.

Decoction of coffee does not contain albumin or legumin.

Graham, Stenhouse, and Campbell found in roasted cofi^ a brown volatOe oil (the
eaffecne of Boutron and Fr4my^. heavier than water, easily soluble in ether, sparingly
in boiling water, but communicating to the water a strong aromatic odour. They
also found from 2*5 to 3*0 per cent nitrc^n and sometimes a little sugar.

Von Bibra finds that when ground coffee is treated with boiling water in a French
coffee-machine, — in which the boiling water is forced by the pressure of its own vapour
from the lower vessel into the upper, which contains the cofiee, — from 10 to 12 pts.
out of 100 of the coffee pass into the solution: by complete exhaustion, a larger
proportion would of course be dissolved. The proporaon of soluble matter is increased.

COFFEE. 1073

up to a certain pomf^ by strong roasting. According to Cadet> coffee roasted to a red-
brown colour yields 12*3 per cent ; chestnut-brown coffee 18-5 per cent ; and dark
brown 23*7 per cent of soluble constituents. Payen obtained 37 per cent, and the
residue, after thorough exhaustion with water, yielded only 1'2 per cent ash, J of which
consisted of soluble salts. Lehmann found in roasted Java coffee, 21*5 per cent,
soluble matter. Vogel found 39 per cent, (in the raw beans only 25 per cent.). Soft
water dissolTCS out more than hard water; water containing carbonate of soda most
of all.

The aqueous extract of coffee yields 16*6 per cent ash, containing 51-5 per cent
K«0, 8-6 Ca»0, 86 MgK>, 0-2 Fe*0*, 100 P«0», 40*0 SO*, 20'6 C0», 20 KCl, 0*7 SiO«,
with 0*5 sand and charcoaL

Ph^fsioloffical action. — Coffee acts physiologically in two ways : first, by stimulating
the action of the nervous and vascular systems, thereby producing; a feeling of cheerful-
ness and mental activity ; secondly, by retarding the transformation of tissue, and thus,
to a certain extent, supplying the place of other nutriment - Experience has in fact
shown that labourers who habitually take coffee as a beverage, require less nitrogenous
food to keep up their strength than those who do not take coffee. The stimulating and
invigorating action of coffee appears to depend both upon the empyreumatic oil and
the caffeine ; the retardation of tissue-transformation, chiefly on the empyreumatic oil,
the caffeine acting in this manner onh^ when it is present in considerable quantity.
The unpleasant symptoms which sometimes attend an excessive use of coffee, such as
headache, trembling, and a peculiar delirious sensation, are mainly due to the caffeine
(J. Lehmann, Ann. Ch. Pharm. Ixxxvii 207). The assamar and tannic acid in roasted
coffee doubtless also contribute in some way to its phvsiological action.

Tea resembles coffee in containing theine (identical with caffeine) and tannic acid ;
and, accordingly, its action resembles that of coffee to a certain extent; it differs from
coffee, however in not containing the peculiar empyreumatic oils just mentioned, and
in being richer in theine and tannin.

JLdulterAtloB of Coffee. (Graham, Stenhouse, and Campbell, loc. cit) —
Various substances, more or less resembling coffee, are used, either as substitutes for,
or additions to it A great variety of seeds were tried in France during the con-
tinuance of the continental blockade, including — in addition to maize, barley, oats,
and the other cereals — the seeds of the yellow flag (Iris pseudo-acorus^ the grey or
chick pea (Oicer arieiinum), the milk vetch or Andalusian astragalus {Aatroffolus
boeticus\ the Hibiscus esctUenttiSj the holly, Spanish broom, acorns, chestnuts, the small
lupine (iiupintts augiutifolia\ peas, haricots, norse-beans, sunflower, pips of the goose-
berry and grape eglantine {Bosa viUosa), and the capsules of box {Bttxus sempervirens).
Of Uiese the yellow flag, a common marsh-plant in England, appears to offer the
greatest similarity to co£tee ; but it is doubtful whether the resembhuice extends beyond
the aroma of the seed when roasted. Indeed no seed appears to be known which, when
roasted and pulverised, forms a true and efficient substitute for coffee, either in the phy-
siological properties or in the chemical composition of the soluble extract The poorer
sorts of coffee-beans are sometimes tinted by dusting them with coloured powders, such
as Prussian blue, powder of lime-tree charcoal, green earth, &c., mixed with a little gra-
phite, to give them the silvery appearance of the finer sorts.

The use of certain roots roasted and pulverised, to mix with ground coffee, is, how-
ever, much more common. The roots most used for this purpose are those of chicoxy
(Cichorium inii/btts)^ carrot, beet, rush-nut {Cypertts e^ulenttis)^ earth-nut {Arachis
nypogaa\ scratch-weed (Galium aparine\ fern (Folypodium filix Tnas), and butcher's-
broom (Ruscus aeuleatus).

These roots are prepared by cutting them into thin slices, drying them on a stove^
and then passing them through a coffee-roaster, generally with addition of about 2 per
cent of butter, and sometimes of a red powder, to,give them the colour of coffee. In
this country and in France, the root most used as an addition to coffee is chicory,
the annual consumption of which in France amounts to 6,000,000 kilogrammes. In
Germany, beet ana c a r r o t are extensively used for the same purpose. Not one of these
roots contains either caffeine or the peculiar aromatic oils of roasted coffee, and hence
they can never serve as efficient substitutes for coffee ; but they are valued as an addition
to it, because they contain a large quantity of sugar-— chicory as much as 30 per cent
— and consequently, when roasted, acquire the peculiar bitter taste and somewhat of
the aroma of caramel or burnt sugar, which is well known to be one of the strongest and
most general of our gustatory preferences, being that which gires the peculiar flavour
to the several varieties of brown beer or porter (i. 529).

The examination of a sample of ground coffee for the detection and estimation of
these admixtures, is a matter of some difficulty. As none of the roots contain caf-
feine, the quantitative determination of that base in the sample may give an approzi-

VoL. L 8 Z

1074 COFFEE.

mation to ita d«gree of purity. For this pfinpofle, the eoffiw mgj be eihaMlcd Vj
lepetttod boiling with hot water; the aolatioii ooncentnted a UUle by evapontion;
the caffetannic add, and certain other sabetanoea^ precipitated first bj nentnl and tbcn
by basic acetate of lead; the ezceae of lead remored £roin the fittnte hj nlphinetted
hydxogen; the liqnid then eraporated to dimness; the dry matter ahaastodvithipint
of specific grayity 0*840 ; and the alcoholic eolation eoncentrftted to a nrady tjiupy
state, and left to stand for ten days. The crystals of eaffeine» vhidi theo Mpante,
are coUeetad on a small filter, compressed poverfnlly to remore the mother>Uqiiar, then
rediasolred in a small qnantity of water, and the solution is efaperated and oystiJliMd
anew. It yields slmost pore caffisine, the onantitjr of which in the sample is tins
determined. Samf^ of pipe ooilee of sereralTarieUes yielded, by this trQatawBt»froai
0-80 to 1-01 per cent caneine ; if then the amount obtained from a gireii sample bs
less than 0*80, the admixture of some other sabstance may be infietred. (Granan,
Stenhonse, and CampbelL)

If it be desired merely to determine whether a grrsn sample of ground yegetaUs
sabstance contains coffee or not^ the search for caifpinw may be made b^ a simpla
process, namely, by evMraiating the aqneoos infusion to dryness after addition of lims,
treating the diy mass with ether, leaying the solution to crystaOiae by eTapontion,aiid
testing the crystals with nitric acid and ammonia, wherel^, if caf&ine be pnsenl^ the
parole colour of murezid is produced (L 708).

The formation of qui none by the oxidation of caflfetannic add (i 7091 may also
bensedasameansof recognising the presence of coflfee in a mixtme. Fortoiipanoas
the inAision of the powder is evaporated to syrap, and 1 pt. of the reddae is distuled
with 4 pts. peroxide of manganese, and 1 pt. oil of yitriol diluted with 1 toL vsttr;
quinone is then siyen ofl| part subliming in crystals, while the rest passes OTa with
the wateiy distiUate. (Graham, Stenhouse^ and CampbelL)

The adulterations of coflfee an most easily detected by their physical charadeta,
by the proportion of sugar contained in the sample, and by the compodtion of the aafa.

1. AeHon of Water, — ^VThen hot water is applied to the powder of chiooiy and other
rootSi it softens immediately, ftom the Uahtj with which the water is imbibed;
whnpeas the pprains of coffee remain hard and gritty. Boasted grdn, such as wheat
and bariej, gires with hot water a thick mudlaginons infiodon, while the infosion cf
coffee is remarkably thin and limpid. The grain-inindon genezally oontdia starch,
and giTes a blue coloration with iooine, whereas the infddons of both coffee snd cfaicoiy
appear to be quite destitute of stsrch.

2. Colouring Pmoer. — Chicorj^ and the aUied roots impart to water a modi deeper
coloor than coffee, Uie coloration beins also much more rapidly prodnoed. By in-
fosing sqnsl quantities of the several substances with boiling water, and obserrisg the
colour 01 the filtered inftidons in glass tubes <^ equal diameter, it was fbond:— if the
colouring power of caramel be represented by 1000, that of diioory is 4JK), of maiae
360, of dandelion-root 300*3, of rod beet 800*3, of bread-ratings 274*72, of aooras
200, of highly-roasted coffee 173*31, of medium-roasted cofiee 143*88, of peas 7318,
and of brown malt 25. Hence it appears that chicory has more than three times the
coboring power of highly-roasted c^See ; maize double that of coffee ; whereas pess sad
beans haye only about ludf the colouring power of coffee.

In infndons prepared with cold water, chicory exhibits four times the colouring pows
of coffee. If a few grains of rossted chicory or any oUier sweet root be dzoppM into
a glass of cold water, without being stirred, a yellowish-brown colour diilbses rapidly
through the liquid, idiereas pure coffee giTes no "wunM^y colour to the water aader
similar drrumstancea.

3. 8ptci/!c Gravify of the Infiuione, — Coflfee is sharply distinffuished fiom the two
most important classes of adulteiatiiig substances, the roots ud ceradSi by the eom-
paratirely low spedfic grarity of its infosion. The comparison may be made by du-
solring 1 pt of the substance in 10 pts. of cold water, rudnff the temperatarc to the
boiling point, keeping it there for about half a minute, and tlien filtering. The I^
minous seeds gire iiSbdons of low spedfic gravity : peas 1007*3, beans 1008*4. The
Fpedfic grarity of coffee infodons Taries fiom 1008*0, for Mocha, to 1009*5, that of
Costa Rica eoWee ; that of chicory infodon is much higher, ranging in different san^ks
foom 1019*1 to 1023*2. Infodons of cereals stand equally hi^ or h^er, in the
scale of grarity, rye-meal girinc 1021*6, and maize 1021*5.

4. AcUon of Etker,—The foltowing substances, agitated with ten times their weigbt
of ethsr, gire diflferent proportions of matter soluble in that liquid, jiz. :

Boasted beans 1*81 percent of oil snd resin,

maise . . . • , 6-15

t» MMMmaMfv • • • » W Atf I, „ n

„ chiooiyfTorkshire) . . 6-83 „ „ •.

•• tt N

coffee (Mocha) . . 15*03

COFFEE LEAVES — COFFEINE. 1075

the laft indnding piobably 1 per cent of caffeine. Hence it appeen that ooflbe yields

to ether much more soluble matter than beans, maize, or chicory, which represent the

three classes of legnminona seeds, cereals, and sweet roots. The fSat obtained from

chicory was donbtless that which is added in the roasting process, to prevent burning.

The experiment with ether is easily made, and may sometimes prove valuable.

6. Quantity of fermentable Sugar. — The quantity of fermentable sugar in sweet

roots, both before and after torrefiu^tion, is mu<^ greater than in coffee. By subjecting

the different substances to fBrmentation with veast, and determining the amount of

alcohol in the distillate (see Sugaa), the sugar in raw coffee is found to vary from 6 '20

to 7'62 per cent. ; that of roasted ockSee from 0*0 to 1*14. The proportion in chicory

and other sweet roots is given in the following table:

Sagar per cent

^ * ^.

Raw. Boasted.

Foreign chicoiy 23*76 11*08

Guernsey „ 30*49 15*96

English „ 35*23 17*98

„ „ (Torkshire) .... 32*06 9*86

Mangold-wurzel 23*68 9*96

Carrots (ordinazy) 31*98 11*53

Turnips 80*48 9*65

Beetroot (red) 24*06 17*24

Dandelion root ...... 21*96 9*08

Parsnips 21*70 6*98

Bo'nka (a coffee substitute) . . . • t ^^'^

These numbers are sufficient to show that the fermentation-test affords an easy
method of distinguishing these roots from coffee. The leguminous seeds, cereals, and
other seeds are not so easily distinguished b^ this method, the proportion of sugar in
the roasted material vaiyine only from 0*74 in lupine seed to 2*70 in aooms.

6. Comjpoaition of the AsH, — Coffee is remarkably distinguished from the roots and
cereals by the small quantity of silica in its ash, which never exceeds 0*5 per cent. ;
and even this small quantity, which is not always present, probably arises from acci-
dental adhesion of sand to Uie beans. Chicory-ash, on the other hand, contains (after
deducting sand) from 3*81 to 10*52 per cent, silica (L 962), and roasted dandelion-root
11*26 per cent. The proportion of silica maybe determined, without making a formal
analysis of the ash, hj simply digesting it in strong hydrochloric acid and weighing
the residue. In lupines, aooms, maize, and parsnips, the proportion of silica is not
laige enough to afford a good distinction from coflfee; but lupine-ash contains 17*75
per cent of soda, which, according to Qraham, Stenhouse, and Campbell, is not found
in coffee-ash; the ashes of lupines and of acorns likewise contam twice as much
chlorine as ooffee-ash, and in the ash of maize th^ proportion of phosphoric acid is
very high, vis. 44*5 per cent, whereas in coffee-ash it is only alx>ut ten per cent.
Beetroot ash is distinguished from ooffiBe-ash by its very large amount of chlorine,
which varies from about 8 to 29 per cent.

7. Proportion of Nitrogen, — ^The nitrogen in foreign raw chicoiy amounts to 1*51 per
cent in tne roasted root to 1*42 pear cent. English chicory gave, m the raw state 1*86,
in the roasted state 1*74 per cent nitrogen. In roasted coffse the proportion of ni-
trogen is rather greater, vis. about 2*75 per cent ; but the difference is not great
enough to afibrd a good mode of distinction. It may, however, be admitted that less
than 2 per cent of nitrogen in coffee is a strong presumption of adulteration with
chicory or some other root

On the whole, we may conclude that the best indication-tests of the presence of
foreisn substances in ground coffee are afibrded by the colouring power, the specific
gravity of tiie infdsion, the fermentation-test, and the composition of the ash.

OO&VWM XMMkVWMm The leaves of the coffee tree have been examined by
Stenhouse (FhiL Hag. [4] viL 21), who received a sample of them, dried at rather
too high a temperature, from Sumatra. They were found to contain 1*2 per cent caf-
feine, and altogether 2*1 per cent nitrogen ; as some of the caffeine may have been
decomposed in the diving of the leaves, the real proportion may perhaps amount to
1*5 per cent They also appear to contain a larger proportion of odTetannic add than
the beans ; the proportion of matter extracted hjr water was 38*8 per cent An infu-
sion of the leaves in boiling water has a deep brown colour, and in taste and odour
resembles a mixture of tea and coffee. The leaves might therefore^ perhaps, be used
as a substitute for tea-leaves or coffee-beans. Their use for this pappose was first
suggested by Van den Corput in Brussels. (Ann. Gh. Phann. Ittxit, 244.)

COlvanra. Syn. with CAmma (L 707).

8b2

1076 COGNAC — COHESION

OOOVAO. The finest kind of French tnandy distined from wine ; it tiiikeB its
name from the town of Cognac, in the Dipartement de la Charente. (See Brakdt,
I 662.)

COBOBATZOW. The continuous redistillation of the same liquid from the same
materials.

OOBBBXOar and JU0BB8ZOV. Cohesion is the force by which partidee of one
and the same body, or homogenous particles in general, are held together. Adhesioii
that which holds together the particles of two diasimilar bodies when brought into
close contact.

These forces i^pear to act only at fjistancpw inappreciable to our senses. When a sdid
body, as a piece of wood or stone, is broken, the pieces cannot be made to cohere again
by merely pressing them together, because the suifiMies, being uneven, can only come
into contact at a few points, and the cohesiTe force is imperceptible; but if the bodies
touch each other by large flat surfaces, as when two well polished plates of g^ass or
metal are pressed together, they cohere with ^rcat force.

The adhesion between the particles of dissimilar bodies is determined by precisely
similar conditions. Plates of lead and tin, or of copper and silver, may be almost in-
separably united by strong pressure betweoi rollers. Adhesion takes place with peco-
liar facility when one or both of the bodies is in the liquid state, because the partides,
being free to move, can easily adapt themselves to each other. All liquids, like oil and
water, which do not mix, adhere with more or less force by their suiiaoes, and adhesion
shows itself in most esses when a liquid comes in contact with a solid body, the liquid
being then said to wet the soHd. A glass plate suspended from the arm of a balanee
and made to* touch the surface of water requires considerable force to separate it If
the liquid which adheres to the sur£euie of the solid afterwards solidifies^ tiie adhesion
becomes still stronger : this is the principle of cementing. When two glass plates are
joined together with sealing wax, the adhesion is sometimes so strong that in attempt-
ing to part them, particles of the glass separate from each other rather than frv>m the
wax.

Notwithstanding the great difference whidi appears to exist between these mole-
cular forces, and that of gravitation, the former acting only at insensible, while the
latter acts at all distances, it is not difficult to show that bodi kinds of attraction maj
be merely different modifications of the same power. Let it be assumed that all ulti-
mate atoms attract one another with forces varying directly as their masses and in-
versely as the squares of the distances between them, and that the aggregates of atoms
constituting the physical molecules are not spherical, at least not in aU cases. The
law of molecular attraction will then depend in great part on the forms and dimen-
sions of these molecules. The attraction between spheres composed of particles which
attract one another according to the law of the inverse squares, is the same as if the
whole matter of each sphere were concentrated in its centre, that is to say, the
spheres attract one another inversely as the square of the distance between their
centres. But in bodies of any other shape, the attraction may be regarded as consist-
ing of two parts, one following the law of the inverse squares, just as if the bodies were
spherical, the other dependent on the shape of the bodies, and varying inversely as the
cube of the distance between their centres of gravi^. Such is the case with the attrac-
tion of the earth and moon. The equatorial protuberance of the earth produces certain
perturbations in the relative movement of the two bodies, which vary in magnitude,
according to the law last stated, and would become much more perceptible if t£e earth
and moon were nearer to each otiier, but would vanish if the distance between them were
much greater than it is : for example, if the distance were diminished to ^ of its present
amount, the principal part of the attractive force, which determines the elliptical zno-
tion, would be increased 100 times, but the disturbing force depending on the figure
would be increased 1000 times. If then the law of attraction between the molecules of
bodies be affected in like manner by their figures, it will follow that at the extremely
small distances existing between the particles of a solid body or of two bodies pressed
closely together, the molecular force, which determines the phenomena of cohesion and
adhesion, may become almost immeasurably greater than when they are separated by
any appreciable distance : for the molecules are so minute that the smallest distance
appreciable to our senses may be regarded as infinitely great compared with thor di-
mensions, so that it is only at insensible distances that the influence of their form
makes itself felt.

The force of cohesion varies with the temperature and the nature of the body. In
gases, in which the dimensions of the actual material particles must be siqpposed to be
infinitely small as compared with the intervals between them, the cohesive force is
little, if at all perceptible ; in fact, the particles of gases have a constant tendency to fir
asunder. (See Gasbs and Hi^t.)

COHESION.

1077

. In liquids, the distance between the particles is still suffleientlj great^ compared
vith their size, to give great freedom of motion, but not sufficient to render the
molecular attraction depending on the form of the particles imperceptible ; hence
liquids, though their particles yield with ease to any external force, neyertheless ex-
hibit, when left to themselves, a tendency to assume the spherical form, that being
the arrangement in which a given number of particles occupy the smijlest space ;
since, however, the liquid mass is subject to the influence of other forces, as gravita-
tion and adhesion, the spherical form of a drop is never perfect ; this may be seen in
the form whidi drops of mercuiy assume on glass, or water on glass smeared with fat
or lycopodium. As the temperature rises, the cohesive force becomes less, in conse-
quence of the greater separation of the particles ; consequently a heated liquid gene-
rally forms sn^er drops than a cold one. Different liquids exhibit different degrees
of cohesion, the cohesive power being veiy nearly proportional to the density.

In solids, the cohesive power shows itself in the highest degree, the particles
not being able to move freely over one another, so that an external force, if it
does not produce disruption, gives rise to an equal and parallel motion throughout the

mass.

The force of cohesion in a solid is measored by the resistance which the body offers
to any mechanical force tending to separate the particles. The resistance offered to
a force tending to pull the putides asunder is called the absolute cohesion or
tenacity; the lateral resistance to fracture is the relative tenacity; and the resist-
ance which the body opposes to a crashing force is sometimes called the retroactive
tenacity {rucikwtrkende FeatigkeU). These three modifications of the cohesive
strengtli have all been made the subject of direct experiment in numerous bodies ;
they are connected with each other by relations which are capable of exact
mathematical analysis, but the investigation of which is foreign to tne character of
this work.

AhaoluU tenacity — Huschenbroeek made numerotis experiments on the absolute
tenacity of bodies; his results are given in the following table, which shows the
weights required to break rods or wires of various materials when suspended from.
them:—

AhaotuU Tenacitiei of SoUda

HorixoDtal section

Horisootal nction

■a|iqaareline.

es 4 sq. oendmetrtt.

Elm-wood 87 pounds

918 kilogr.

Vine (Pinua satfestrie) ,

. . 97 „

• 1021 „

Fie (Pintu abies) .

. 67—88 „

600 929 „

Oak .

. 110—140 „

1160—1466 „

Beech .

, 136—148 ,,

1349—1686 „

Ebony .

, • 89 „

934 '„

Copper wire .

. 266 „

2782 „

Brass .

. 340 „

3660 „

Gold .

. 442 „

4646 „

Lead .

. 26 „

272 „

Tin . . .

. 48 „

467 „

Silver . .

. 826 „

3411 „

Iron

. 898 ,,

4182 „

Glass (white^
Hempen cord i

> 1

* 14-22 „

. 142—233 „

1 1

, 2

14—60 „

360—360 „

The great variation in the strength of hempen cord arises from the unequal quality
of the fibre. Thin cords are comparatively stronger than thick ones, because they are
made of better hemp.

The number for gold in the above table is doubtless too high. According to Count
Sickingen, the tenacities of diffisrent metals are to one another in the following propor-
tions:—-

. 304696
. 362927
• 669880

The following table exhibits the absoluto tenacities of different metals at the tem-
peratures of 0^, 100°, and 200° C, as determined by Baudrimont (Ann. Ch. Fhys.
[3] -rrr 304.) The upper number opposite each metal gives the highest tenacity ob-
served ; the lower number the mean of each set of experiments :

Gold .

. 160966

Copper . ,. .

Silver • •

. 190771

Soft iron (Swedish)

Platinum •

. 262361

Hard iron • •

1078

COHESION.

Geld .

PUtina

l*jKDaidiii]i&
Iran

Tenacity to gninme* for a trantTcne tectiai of 1

5 19051
( 18400

5 23026
\ 22625

5 25838
X 25100

( 28620
\ 28324

( 36983
] 36481

(209813
{205405

\Wfi

200°

15766
15224

20421
19284

22050
21873

24526
28266

82871
32484

201039
191725

13094
12878

18118
17277

19839
18215

18705
18577

29212
27077

213305
210270

These immbefs flhov that the tenacity dimmiahee fbr tiie most part as the tempera-
; iiQii, however, eidiibitB an exception, being more tenacionfl at 200^ than

aiioo(>a

■gmrfiTfff to emtim^.— The following taUe if the leenlt of experiments hj George
Bennie. Jul, pnUiahed in the lint part of the FkOotopkieal TranMutums for 1818.
Mr. Beanie fcond a eobie inch of the following bodiea cmahed hj the fdlowing

1284

1606

1928

3860

can pine
White doJ
En^iAoak

A priam of Ftetland sfeon^ S indies long
Ditto akatnaiy maihle . • •

Cuimofllmdk.

Chalk

KftdcefapalendeokNir

Boe-etone, GhNweBtenhira ..•.<•

Bfldhadt,BMonoftwotzial8

Tdkv-Aice haked Hammerndth psvion, three times .

Bunt dittos mean of two trials

Stomhridge, or tie hridc

Doby giit, a led fiEiahle sandstone ....

Derhr giift ftom another qioany

BiUala white freeskoMi not stzatifted . . . .

Portland ....•• ^ « •

white fireeitone

jarin^ with the strata ....

Dittos against the strain

White stataaiy maiUe, not Tained ....
Bramky-Fatt mndstnn^ near Leeds, with sterta .

Ditto, against strata

Oonidi granite . •

Dvadee sandstone^ or breeda, two kinds

A two indi cabe (tf FHtlaiid

Cn^detth, with rtiata

DeroBobire red marble^ vsaegatod • . • .

2-085
2*168

Dsteiheafl granite^ hard doee grained

2-316
2-428
2*423
2^28
2-452
2-507
2-507
1-760
2-506
2-506
2-662
2-650
2>i23
2-452

2-584

9*598
2-599
2-697

805
3216
8688

1127

1265

1449

1817

2254

3243

3864

7070

9776

10264

10284

12846

12856

13632
13632
14302
14918
14918
15560

16712
17354
18S36
19934
20610
90742

COHESION. 1079

Cubes ofl\ inch (caniinutdy,

Cnuhlng weight
Sp. gr. in Um. at.

VeiY hard freestone 2*528 21254

White Italian Teined murble 2725 21788

Aberdeen granite^ bine kind 2*625 24556

Cubes of different metals of \ inch were icroshed by the following weights : —

Ibt. ST.

Cast iron 9773

Cast copper 7318

Fine yellow brass 10304

Wronght-cqpper 6440

Cast tin 966

Cast lead 483

Bars of different metals, 6 inches long, and J of an inch square, were suspended by
nippers, and broken by the following weights : —

llM. «▼.

Cast iron, horisontal 1166

Ditto, Tertical 1218

Cast steel, preTioosly tilted 8391

Blistered steel, reduced by the hammer 8322

Shear steel, ditto 7977

Swedish iron, ditto 4504

English iron, ditto 3492

Hivd gpn-metal, mean of two trials «.»... 2273

Wron^t copper, reduced by hammer 2112

Cast copper 1192

Fine y^ow brass 1123

Cast tin 296

Cast lead 114

On the tenacity and other mechanical properties of eaat iron, a large number of ex-
periments were made by Stephenson, Fairbaim, and Hodgkinson, in connection with
the construction of tubular bridges (The Britannia and Conway Tulndar Bridaes, by
Clarke, London, 1850; Ann. Min. [4] xz. 427). The experiments on the resistance
to direct tension, gave for the absolute tenacity of oast-iron a mean yalue of 10 to 11
kilogrammes for a square millimetre. The retroacdye tenacity was found to be on
the arerage 5*7 times greater than the absolute tenacity.

The tenacity of gla9$ has been examined by Fairbaim and Tate (Free Boy. Soe.
z. 6). The absolute tenacity determined by direct stretching was found to be for :

Traacl^ per iq. in. in Ibc

FHnt glass (best ; specific graTity 8-0782) 2413

Oreen glass (specific gmyity 2*5284) 2896

Crown glass (extra white ; specific gravity 2*4504) . . 2346

But from experiments on the resistance of glass globes to internal pressures, much
higher Tslues were found for the absolute tenacities, Tis. for :

Tenacity in 11m.

Flint glass 4200

Green g^tass 4800

Crown glass 6000

These results are regarded by the^authorsas more trustworthy than the former, be-
cause the globes were better annealed than the rods used in the first experiments.

Experimento on the resistence of glass to crushing were made upon small cylinders
and cubes crushed between parallel steel surfaces by means of a lerer. The cylinders
were cut from rods drawn to the required diameter while hot, and then annealed.
The cubes were cut from much larger portions, and were probably less thoroughly an-
nealed. For this reason, the experimente on cylinders, which gave neailytwice the
resistance afforded by the cubes, are regarded as the more trustworthy. The ibllow-
ing table giTcs the mean results :

1080 COLCHICEINE— COLCHICINE.

Sesistanee of Glass

to Crushing.

Flint glass

Green ^aM

Crown glass

Mean oriMhlnc weight In lbs, per eq. tnch. 1

I'or cjUoden.

Foreob..:

27582
31876
31003

13130
20206
21762

CO&CKZOanra, G**H«<NK)" (Oberlin, Ann. Ch. Phja. [3] L 108).— An alka-
loid prepared from colchicine by acidulating the aqneons solution of that bodj with
sulphuric or hydrochloric acid, concentrating the liquid to dryness over the water-
bath, then adding water, and crystaUising from aloohol the yellow mass which
separates. At the same time there is produced, by the action of the acid on the col-
chicine (perhaps impure), a resin whidi dissolves in alcohol and in ether, and with
deep red colour in ammonia or nitric acid. According to Oberlin, oolchiceine exists
ready formed in the seeds of Colckieum atUumnale.

Colchiceine crystaUises in colourless nacreous laminiB or needles, sparingly soluble
in cold, more easily in boiling water, easily soluble in alcohol, wood-spirit, and chloro-
ibrm. It melts at 155^ C. and becomes coloured at 200^. It dissolres with deep-
yellow colour in strong nitric add ; without colour in sulphuric, hjdrocfaloric, and
acetic acid. It is insomble in alkalis, appears to unite with baryta, is coloured green
by ferric chloride. The alcoholic solution is not precipitated by lead-salts, pUtinie
or mercuric chloride, nitrate of silver, or tincture of galls. ^

Colchiceine exerts, sometimes at least, a poisonous action when injected into the
stomach. Oberlin states (Compt rend. liii. 1202), that 0*1 gnn. killed rabbits in
12 hours, and 0*05 gnn. in a few minutes ; but according, to another acoomit (Ann.
Ch. Phys. [3] L 114), even 0*6 grm. produced only temporary symptoms.

OO&OBZOZVa. This alkaloid, which is contained in all parts of the Colckicvm
autumnale, and probably also in other species o( colckieum^ was discoyered by Pellet ier
and Oayentou (Ann. CIl Phys. [2] xiv. 69), who however regarded it as identical with
vcratrine. It was farther examined by Geiger and Hesse, who first, in 1833,
(Ann. Ch. Pharm. vii. 274) recognised its separate identity, and has been more
recently investigated by Hub sen man n (Arch. Pharm. [3] xcii. 330), Aschoff,
ilnd. Ixxxix. 4), Bley (ihid. 18), and others.

l^eparaUon, — 1. The bruised seeds of oolchicum are macerat«d with alooho.
containing sulphuric acid ; the extract is treated with lime, the filtered liquid sa-
turated with sulphuric acid, and the aloohol expelled by distillation. , The concen-
trated aqueous solution is then decomposed with carbonate of potassium ; the pre-
cipitate IS dried, and dissolved in absolute alcohol ; the solution is decolorised with
animal charcoal ; the filtered liquid is evaporated at a g^tle heat ; and the alkaloid
thus obtained, is purified by repetition of the treatment with sleohol and animal char-
coal (G-eiger andHesse). — 2. Acoordingto Htibschmann, a larger product is obtained
by exhaustinjg the seeds with Z\ pts. alcohol of 90 per cent^ then distilling off the
alcohol, precipitating the residual liquid with carbonate of potassium ; exhausting the
dried precipitate witn ether, and finally with sulphuric acid, to separate resin ; and re-
precipitating with carbonate of potassium. — 3. Aschoff boils the comminuted seeds
with water, neutralises the decoction with lime-water ; filters after boiling, and eva-
porates to the censistence of an extract; then exhausts the extract with alcohoU
continuing the process as long as the alcohol acquires thereby a bitter taste. The
residue left after the distillation of the alcohol, is dissolved in water and precipitated
with tannic acid; the precipitate is washed and pressed, then dissolved in alcohol,
and digested with a sufficient quantify of recentiy precipitated ferric hydrate at
30^ C. ; lastly, the filtrate is evaporated, and the residue treated with absolute alcohol,
which dissolves out the pure colchicine. — 4. Polex exhausts the bruised seeds with
a mixture of 4 pts. ether and 1 pK alcohol, evaporates to dryness, dissolves the
residue in water, and purifies the dissolved alkaloid with animal charooaL

Bley and Aschofl^ obtained from the seeds, as a maximum, 0*2 per cent of colchicine.

Colchicine may likewise be prepared by simUar processes frx>m the flowers, leaves,
and bulbs of the plant

VtfyptTtks. — G)lchicine czTstaUises frt>m its alcoholic solution, on addition of water,
in colourless prisms and needles : the alcoholic or ethereal solution leaves it on evapo-
ration, in the form of a transparent varnish (Geiger). According to other chemists,
colchicine is always obtained as an amorphous yellowish iriiite powder. It has a
persistentiy bitter taste, not burning like that of veratrine ; it is inodorous, and does not

Tha oompodtioii of eolcbicitiB has n
to Bier, it eoDtaiiu Gfi'O per eent C, 7i H, and 13-0 N, which he represents b; tbe
empincal fbnnnla CH-lPO", althongh his remits agree better with C-H^S'O",
or CH^ITO*, Aschoff found 66-2 C, 6-2 H, and 2-8 N, whoace he deduces the
formula ClfNO". The great differeDceia Uie nitrogen determinutieoB, and certaia
difierencea in the properties of the bsae, as ohierred by these two chemists, seem to
show that they must have been operatii:^ either npon different bases, or on the suao
in yerj different degrees of purity.

Colchiciiie dissolvea vith modersto fiidlily ill water, according to BiibscbmHan, in
leM than2p(a. at 22° C; this property distingQisheB colchidQe from vers triaa, which is
iiisolnble in water. It dissolves easily in alcohol, less easily in pure ether ; at 20° C.,
in 18 pts. ether of speciflc gravity 0-71. Chloroform dissolres it readily, and with-
drawa it for the most part from tbe aqueous eolation on agitation.

Colchicine, when strongly healed, melts and decomposeswith intumescence (according
to Bley, it volatilises at 112° C). Strong citric add colonrs it deep violet or blue,
quickly changing to oliv&j[reea and yellow; strong sulphuric add colours it yellowish-
brawn, not violet, thus afiording a distincUoQ &om veratrine. Phosphoric acid and
hydrochlorie acid coloor even dilute solutions of colchicine distinctly yellow ; chroniio
add coloun the solution green. Chlorine-water renders the solution turbid, and on
subsequently adding ammonia, it asaomes a yellowish-red colour. Colchicine is pre-
cipitated of a kermee-brovn colonr from its aqueooa solution by tincturo of iodine;
yellow by dichloride of platinum, white by tannic acid, the last-mentioned predpitate
being soluble in alcohol, acetic acid, and alkaline carbonates.

The statements of different chemists regarding the behaviour of colchicine with
bases and acids do not agree. According to Ascht^ colchicine is converted by canstio
alkalis intc a brown reeinons mass, soluble in water and alcohol ; it nnitcs with baiyta
and lime, bat doea not decompose alkaline carbonates. According to Bley, a solution
of colchidne mixed with carbonato of soda, yields by evl^ioration a non-ciystalline
mass, fi-ee from carbonic add (?].

According to Qeiger, colebicme nentralisca acids completely, forming extremely bitter
salts, with rough irritating after-taste ; some of them, the anlphato for eiample, are
crystallisable and permanent in the air. They ore very soluble in water and in
alcohol, the aqueous solutions yielding with iodine and with tincture of galls the
same reactions as the pore base ; caustic alkalis predpitate the colchicine &t>m con-
centrated, but not from dilute solutions of the salts. Bley and Aschoff did not succeed
in preparing crystallisoble compounds of colchicine with acids. The aalls were acid,
and soluble in water and slcobol, excepting the lancato, which is insoluble in water.

Fht/tUJogical aetion. — Colchidne is poisonous, even small doses causing violent
Tomiting and purging ; ^th of a grain killed a cat in twelve hours. Tannin is said to
be a gocd antidote. In cases of poisoning by colchicine, the alkaloid may be detected
by treating llie stomach and intestines with strong alcohol, evaporating the liquid,
and again treating the residue with alcohol, or with alcohol and ether, and again
evaporating. Coldiicine then remains as an amorphous yellowish mass, which exhibits
the above-mentioned reactions with mineral adds, tincture of iodine, and tannic acid.

OOKOAIUUM * — ■■■T.w ^B root and seeds of this plant are used in

pharmacy ; according to Coindot, however, the flowers are more active and to be
recommended for the preparation of a tincture.

Tbe flowers, according to Beithner, contain colchicine in combination with tannio
add, also sugar, pectin, gum, fiit, wax, and resin. The dried Sowers, without anthers,
yield i'OS per cent ash (a) ; the dried antheta alone yield 4-Ifi per cent ash (i), con-
taining in 100 parte :

ft.
Potash . . . 37-4 40-0

Silidc add (anhydrous) 77 0 8

Carbonic „ . . 22-3 225

Sulphuric „ . 3-7 62

Phosphoric „ . . lOfl 144

Chlorine . . .IS 06

The ripe seeds eol]ecl«d in July contain in 100 j^, ai
cina, S glucose, and 6 fixed oil, together with ri — — '■
traces of veratiic add and gallic add.

The fresh bnlbt contAin, according to the same authority, 0-2 per cent, colchicine.

1082 COLCOTHAR VITBIOLI— COLLTOINE.

0*3 sugar, 0*5 eolonring matter, 29*0 stardi, together with gallie add, eaEtractm
matter, odlnlose, &c. Colman fbnnd also 21 per cent starch. The starch maj be ex-
tncted from the bulbs by washing with water ; after prolonged washing, it is perfectly
pore and tasteless. (Handw. d. Chem. iL [8] 163).

CO&OOTBAK VXTSZO&It also called Croew Mortis. — ^Ihe brown-red oxide of
iron whidi remains after the distillation of snlphnzic acid from sulphate of iron ; it is
used as a polishing powder.

CMIK&anZV. A oTstallisable bitter prindikle, obtained from CoUetia spimota
(order Rhamnaeea). It forms needles insoluble in cold water and ether, sparinglj
soluble in boiling water, easily in aloohoL It is contained in the alcoholic tincture <n
the plant) which, according to t. Maztius, is used in Brazii as a remedy for inter-
mittent forer. (Handw.)

OOUUimnu C'H^'K. — An alkaloid found, together with many others, among
the products of the diy distillation of animal substances and of coaL It was discoyered
by Anderson in 1866 (PhiL Mag. J. [4] iz. 146, 214), who obtained it from bone^-oQ,
and was afterwards found by Greyille Williams in the bituminous shale of Dor-
setshire (Chem. 8oc Qu. J. TiL 97), in coal tar, and in the impure quinoline obtained
by the drjr distillation of quinine and dnchonine (Chem. Oac, 1866, p. 308). It is
isomeric with ethyl-phenylamine, ethyl-piooline, dimethyl-phenyhuaine, and ^lidine.
PrepentUon, — 1. The portion boiling above 170^ C. of the mixture of volatile bases
obtained from bone -oil (L 626), is mixed with a considerable quantity of strong nitzie
acid, which acts vezy fiolently upon it) thereby acquiring a deep red colour, and <m
boiling erolTes nitrous acid fiunes and an odour of bitter almonds. The part boiling
at 18^ G. must be well cooled while being mixed with the nitric acid, to prerent ex-
plosion. The acid solution, when mixed wiUi water, becomes turbid, from the separation
of a reddish-yeUow oil, which seems to be impure nitro-benzene; the acid solution is
filtered through moist paper, and the filtrate is boiled for some time to expel the last
traces of the neutral oils, tii^ saturated with potash and distilled. The oil ¥^<di
pamrs over with the water is repeatedly rectified, and the portion boiling between
178^ and 180° is collected. The part of the mixture of bases boiling above 170° con-
tains a considerable quantity of phenylamine, which cannot be removed, either by
repeated rectification or by reczystaUisation of the oxalate ; by the action of nitiic add
it is destroyed, whilst tiie alkalis homologous with odlidine remain undecomposed. —
The part boiling between 172° — 180°, when treated in this manner, yields, by distilla-
tion with potash, an oil which begins to boil at 160°, and is eompoeed for the most
part of lutidine; while the portion boiling above 180° yields an oil, the greater part of
which goes over at 179° and when rectified yields pore colHdine. (Anderson.) —
2. When the mixture of chinoline with other bases, which is obtained by the dis-
tillation of dnchonine with potash, is subjected to oft-repeated fractional distillation,
the portion boiling between 177° and 182° C. yields, with solution of platinum, chloro-
platinate of oollidine. This salt may also be obtained from the fraction boiling be-
tween 182° and 187° if another base mixed with it has previously been destroyed by
means of nitric add. (Gr. W illi am a.)

3. Gr. Williams mixes the naphtha obtained by the distillation <rf the bituminous
shale of Dorsetshire with sulphuric add; boils with water until all the tar is eon-
verted into resin, and all the pyrrol is removed ; concentrates the liquid; neutralises
with lime or potash, and distils ; supersaturates the distillate with hydrocfalorie acid ;
removes the non-basic oil ; then supersatntutea the add liquid with lime or potash,
and distils. The distillate is freed from ammonia by washing with strong potash,
dried by solid hydrate of potash, and fractionally distilled until liquids of oonstant
boiling points are obtained. The small portion which passes over between 132° and
138° C. IS lutidine mixed with a little piooline (from the mother-liquor of the dikco-
platinate of lutidine, the double salt of picoline is obtained) ; the pozticai obtained
between 149° and 166°, and between 177° and 182° is puie lutidine ; and that which
passes over between 227° and 268° is ooUidine. — 4. The mixtore of volatile bases ob-
tained in like manner from coal-tar oil is treated, as in Anderson's proeess, with
nitric add, and subjected to repeated fractional distillation. The portion whidi distils
between 160° and 166° C. is lutidine, and afterwards a small quantity of oollidine
passes over. (Gr. Williams.)

iVop«r<te».--Collidine is a colourless, oily fiquid, having a strongly anmialie, not
unpleasant odour. Specific gravity, 0*921 ; boiling point* 17^ C. It forms white fumes
when a glass rod moistened with hydrochloric add is held over it. It is insoluble in
fpoier, but takes up a small quantity of that liquid, which it gives up again to hydrate
of potassium. It dissolves readily in alcohol, eth^, and otZs, both fixed and volatile.

Oollidine dissolves readily in acids, but does not neutralise them. It does not pre-
cipitate the salts of barium, caldum, magnesium, manganese, or nickel, but throws down

dTBtalliK) from hot \n,teT in needles. The eUoraplalinait, (?E."]!I.&ClAcP, fbrmi

orange-yellow SbIcsb, (Andeisoii.)

Etkyl-eoliidint, CH^N - C*H'VCH')K.— The hydriodate of thia baw »
obtained aa an oily liquid by heating collidice to 100° C. with iodide of HfajL On
dt'compoatne it viui nitrate of silver, removing the excels of silver by hydrocblorie
acid, and iniiing the filtered liquid with dichloride cf platinnm, the Alor^atiniOe,
C"H"N.HCLPtCl* is obtained, as a finely -diTided, crystalline, sparingly soluble preci-
piUte (Anderson, Fhil Hag. [4] ix. 211).

COUXVXO AOnt. C?H'0'-°'^^|o. (Frohde [1880], J. pr. Chem. lux.
Z^^).—AIi acid belong to the aromatic aeries OH'°-*0', fbnnd amon^ the producta of
the oiidatloD of the ilbamiaoidal substancea, and of gelatin. Td obtain it. themiitora
of Hcida produced by oxidising gelatin with chromic add is latonted with csrboDate
of Bodium, and evaporated to drive off the neutral roUtile bodies; the nearly diy salts
are decomposed by snlphnric acid ; and the solid acid thereby separated is filtered and
washed. If the residue be then treated with a small quantity of boiling water, the
greater part of the collinic acid remains in fused reddish maasM (about O'SS grm.
coUicie acid &oin 1 Mlogrm. gelatin), while the other acids, especially t2ie benzoic add,
dissolve completely, together with a small portion of l^e collinic acid. By reci^stal-
ligation from water, it may be obtained in small crystals having a prismatic aspect

Collinic " ' ......

S4°; in the dry state, it dow not melt till heated somewhat above 100°. On cooling,
ia solidifies to a waxy mass generally having a radiate texture. At a higher tem-

gatnre, it sublimes. When set on fire, it bums ivith a bright but smo^ flame,
iled with carbonate of sodium, it yields homoid flakes. Heated with hydrate of
potaadom, it decomposer, bat does not appear to yidd any volatile adds.

Collinic acid is a strong add, dissolving in caustic allalis, and decompodng ettr-
bonatea. It forms both neutral and basic aalta. The silver-salts decompose with
firalitj.

A solution of coilinei* ofaniMOtavnn gives off ammonia and becomes a^d on boiling ;
add vapours, however, escape at the same Hme. The bariwn-$ait, SCE'BsO* + u].,
ia crystalline, easily solable in water, gives oft watn of cryatallisatioa when heated,
mel^ and blacfcene at a higher temperature. The ferrk lalt is a light, yellowish-red
predpitate, whidi dissolves wiUi blood-red colour on addition of a small quantity of
add. The neutral tUver-ialt, CH'AgO', is obtained in crystalline scalefl by predpi-
fating the ammooium-salt with nitrate of silver, dissolving the predpitate in water,
and evuiorating over oil of vitriol The mother-liqnor when evaporated gives off add
and yields grey grsjmles of a basic salt, Ag*0. SCH'AgO* ; by continued heating of
the Bolntion, the silver-salt is reduced.

Ad add isomeric, if not identical with collinic add, is produced by oxidising coal-
tar naphtha with dilute nitrio acid (De La Rue and Uiiller, Chem. Soe. Qo. J. xiv.
61), or Bulpho-benzolic add with chromic add. (Church, ibid, £3.)

OOX&XXZa AUBMYSK Hydridi of collul. — This compound occurs, accord-
ing to Frohde (J. pr. Chem. 1ti', 326), among the neutral volatile products of the
oxidation of the albumoids, and of gelatin ; it appears to have been previously noticed
by Schlieper and Quckelberger. It is probably C'H'O (isomeric with phenic acid). It
has not yet, however, been obtained pore, especially not free fii>m hydride of benioyl.
It is a colourless visod oil, smelling somewhat like oil of cinnamon, and turning yellow
from oxidation when exposed to the air. By prolonged boiling with potash-ley, it is
* converted into collinic add. By continued contact with ammonia, it is converted into
* white crystalline sabalance, probably the homologue of hydrobenzamide.

According to Schlieper (Ann. Ch. Pharm. lix. 32), this oil having the odonr of
cinnamon is converted by the action of dry chlorine, with elimination of hydrochloric
add, into a while snbstajice which is insoluble in ether, and when heated with potash-
ley forms a blood-red volatile oil ; the potassinm-salt, on addition of an add, emits
the odour of phenic add.

W (from ihiAAbSi|i, glntdnoDsV A solution of pyro^Iin (gun-cotlon)
in ether. The solubility of this substance m ether, varies considerably according to
the mode of its preparation ; the most explosivs kinds are by no means the most
solubls (see Pisoxtlim). The best mode of obtaining pyroxylin, fbr the preparation
of collodion, is to mix 10 pts. of nitrate of potssdum with 12 pts. of common and
13 pta. of iiiming oil of vitriol; immerss in this mixture, ss soon as it ia made, 1 pt. of
cotton wool, stir it about for five minutes, and then wash it well with water.

1084 COLLTL, HYDRIDE OF — COLOCYNTHIN.

To prepare collodion, pyroxylin obtained in the manner just described is sbaken up
with 16 ptB. ether, in a bottle which can be dosed. 1 or 2 pts. of absolute alcohol are
added after a while, and the vessel shaken at intervals, till the solution is complete.
Lassaigne pours 26 pts. of ether on 1 pt. of pyroxylin, and mixes the resulting
jelly with 18 pts. more of ether. According to other methods, 1 pt. of pyroxylin is
treated with nom 20 to 120 pts. of ether, and from 4 to 16 pts. of aloohoL The soln-
tion obtained by either of these methods is left to stand till the nndissolTed parts
haye settled down.

FyroxyUn is said also to be rendered perfectly soluble in ether by moistening it
with acetone.

Collodion is a dear colourless gummy liquid, insoluble in water and alcohol, but
soluble in ether ; when exposed to the air, it soon dries up, leaying a transpsient cr
translucent residue, which becomes strongly dectric by friction, explodes less easily
by heat, pressure, or percussion than flooculent pyroxylin, and is soluble in ether con-
taining alcohol and in strong acetic add.

When the ethereal solution is suffered to evaporate in a thin film, it dries up quiddy
f o a thin transparent membrane, which possesses great adhesiveness, is tolerably im-
pervious to air, and is not dissolved either by water or by aloohoL These properties
render collodion very useful for a variety of purposes. It is employed with great
advantage in surgery to form an air-tight covering for wounds and bums; when
spread over an incised wound, it greatly promotes the healing by drawing the edges
of the wound together, the film of collodion contracting strongly as the ether eviqio-
rates. As the collodion film is rather solid, and has but Httle elastidty, it has been
recommended to mdt 2 grms. of Venice tui^ntine with 2 gnus, castor oil and 2 gnna.
of white wax, mix the fused maas with 6 grms. of ether, and add the whole to
140 grms. of collodion.

Collodion is also used as an envdope for caustic substances, in order to confine their
action exactly to the desired spot. Iills may be coated with it, so as to render them
tastdess, and wood, paper, and other fabrics may be rendered water-proof by being
covered with it.

Collodion is also largdy used in photography. A thin layer of the solution, mixed
with iodide, bromide, or chloride of potassium, or ammonium, is spread uniformly over
a glass plate, then treated with a solution of nitrate of silver to fi>rm the sensitive
film. 1% appeara to be essential to use anhydrous ether and alcohol for the solvent, in
order to insure uniform evaporation.

Another application of collodion is for making balloons. For this purpose^ a
solution of collodion, not too thick, is poured into a fiask of suitable dimensions, wldch
is turned about to spread the liquid uniformly over it, and then inverted to allow the
excess to run out The ether is now evaporated from the film of liquid which adheres
to the glass, by blowing into the fiask with a pair of bellows, whereby the collodion is
left in the form of a thm membrane on the siuface of the glass. To remove it, tbB
edges of the film are loosened from the glass, a glass tube of suitable character is in-
serted into the neck of the fiask, so that the balloon may adhere to it, and the air is
slowly drawn out with the mouth ; the baUoon then detaches itself from the vessel,
contzacts, and is easUy withdrawn through the neck. It must be immediately blown
out and tied at the neck, so that it may diy in the distended state. Small and thin
balloons do not diminish much in volume as they diy ; but larger ones contract strongly :
this contraction may, however, be prevented by during the ^dloon in warm air. Collo-
dion balloons may be made much lighter than those of gold-beater's skin, so that much
smaller ones wiU rise in the air unien filled with detonating gas (2 vol H and 1 vd.
0). They may be made so thin that a balloon containmg 100 cubic centimetres
shall weigh only 0*03 grms. when empty, and 0*04 when filled with hydrogen ; now the
weight of an equal volume of air is 0*13 grms., consequently such a baUoon will rise
rapidly in the air. Hydrogen diffuses quiddy through their pores. Collodion balloons
become strongly electric by slight friction ; when very thin, they exhibit beautifol
interference-colours. (Handw. d. Chem. ii. [2] 158).

COULTKp BY]>SI3>B OF. See Coujmio Aldbetdb.

OOliXiTSXTB* A hydrated silicate of aluminium, 2A1^0'.SiO*+ 10 aq., found at
Ezquerra in the Pyrenees, near Schemnitz in Hungary, and near Wessenfds in Saxony.
It is white, very soft, earthy, unctuous to the touc^ adheres strongly to the tongue, la
water it becomes transparent and crumbles to pieces : it dissolves in adds and the
solution yields a jeUy by evaporation (G-m. iiL 411.)

CO&OCmmnv. A bitter substance contained in the pith or pulp of the fruit
of Cucumds coloeynthia (bitter apple), a plant growing wild in the Oredan Archipelago,
also in Egf pt^ and other parts of North-eastern Africa. •It haa been examined by
Yauquelin (J. Fhys. Ixsdv. 338), Braconnot (J. Fhaim. z. 416^ Herbergec

COLOCYNTHITIN— COLOMBIN. 1085

{BuehiMr's R^ert. xzxv. 368), Bastick (Fharm. J. Trans, x. 289), and lastly by
Wals (Arch.Pharm. zcyL 241 ; xcix. 338^, who regards it as a glucoside a C^H'^O**.

It is prepared ^m the pnlp of the fruit separated from the seeds. Yanqnelin ex-
hausted the pulp with cold water, and evaporated the extract, the colocynthin then
separating in oily drops, which solidified on cooUng. Lebourdais (Ann. Ch. Phys.
[3] xxiv. 58^ precipitates the aqueous extract with neutral acetate of lead, and treats
the filtered liquid with animal charcoal, which takes up both the colouring matter and
the bitter principle. The charcoal is then washed with water. As long as the liquid
which runs through it acquires a bitter taste, nothing but pure colocynthin is dissolved ;
and on again precipitating it with animal charcoal, boDing the charcoal with alcohol,
and leaving the solution to evaporate, the colocynthin separates in small warty
groups. WaJz exhausts the fruit with alcohol of 0'840 ; evaporates ; dissolves the
extract in wat«r ; precipitates the filtrate with neutral and with basic acetate of lead ;
removes the lead from the filtered liquid by sulphuretted hydrogen ; and precipitates
the colocmithin by tannic acid. The precipitate, which becomes resinous on heating
the liquid, is dissolved in alcohol ; the tannic acid is precipitated with basic acetate of
lead; the filtrate, freed from lead, is heated with animal charcoal; the liquid is
again filtered and evaporated ; and the dry residue exhausted with ether, which leaves
the colocynthin imdissolved.

Colocynthin is intensely bitter, and acts as a drastic purgative. It is soluble in
water, sJcohol, and ether. The aqueous solution is precipitated by chlorine ; it also
yields, with acids and with deliquescent salts, a viscous precipitate insoluble in water.
The solution is also precipitated by acetate of lead and many other metallic salts.

Colocynthin boiled with acids is resolved, according to Walz, into sugar (7*7 per
cent.) and colocynthein, C'**H**0", which remains as a resinous mass, and may be
purified by washing with water, solution in absolute ether, and evaporation.

A body contained, according to Walz (N. Jahrb. Pharm.

ix. 225), in the alcoholic extract of bitter apple (see Cucttmis). When this extract is
treated with water, colocynthitin remains undissolved ; and on treating this residue
with ether, digesting the solution with animal charcoal, evaporating the filtrate,
exhausting with hot absolute alcohol, and leaving the filterea liquid to cool, colo-
cynthitin separates in white microscopic crystals. It is soluble in ether.

CO&oai8ZO ACZHi An acid obtained by Bodecker (Ann. Ch. Pharm. Ixix.
47), from colombo-root, the root of MenUpermum palmaiumy L., CoccttlttspalmatiSy Dec.
To prepare it, the alcoholic extract of the root is exhausted with water or lime-water,
and the solution treated with hydrochloric add. Colombic acid is then precipitated in
white amorphous fiakes, which are strongly acid, nearly insoluble in cold water, veiy
soluble in alcohol, sparingly soluble in cold ether. By the evaporation of its alcoholic
solution, it is obtained in the form of a yellow varnish.

The alcoholic solution of colombic acid is not precipitated by acetate of copper, but
yields with neutral acetate of lead a copious wMte precipitate, which, when dried at
130° C. contains 30*53 per cent, lead oxide, agreeing nearly with the formula
3Pb*0.2C«H"0'». Dried at 100° C, it contains in addition 6HH).

The acid itself dried at 116° C, gave by analysis 66*64 per cent C, and 6-29 H,
agreeing nearly with the formula C«H«0", or C«H«0".H*0.

OO&OBIBZV. Col&mbo Bitter. C^H^Ofj (Wittstock [1830], Pogg. Ann.
XIX. 298. — ^Liebig, ilnd, rri. 30. — ^B6 decker, Ann. Ch. Pharm. Ixix. 39.) — A neutral
substance which constitutes the active principle of Colombo root. Bodecker prepares
it by exhausting the root with alcohol of 75 per cent., drying the extract as completely
as possible, dissolving it in water, agitating the solution several times with an equal
volume of ether, decanting the ethe^al liquid with a siphon, filtering, and evaporating
off the greater part of the ether. The colombin then crystallises out, and is ^urifiea
by rinsing it with cold ether, pressing it between bibulous paper, dissolving it in boil-
ing absolute ether, and concentrating the solution to one-fourth of its bulk. The
greater part of the colombin then separates out ^uite white, the rest reniaining dissolved
in the ether, together with the fat contained m the root To fr«e the colombin en-
tirely from fat, it must be repeatedly crystallised from ether; when quite pure it will
dissolve in acetic acid without separation of oil-drops.

Colombin crystallises in colourleas prisms belonging to the trimetric system. Ob-
served combination, oo P . oo^ oo . oo P a> . P oo. Inclinations of the fiices, oo P : ooP »
125^30': <xP:ooI»a>«152°45'j QoP:ootoo- 117° 16'; I>a> : P oo » 176° 19';
P 00 : 00 P 00 - 123° 39-5' ; oo P : P oo « 119° 31'. The feces are brilliant, but the
crystals do not cleave in any direction (G. Rose, Pogg. Ann. xix. 441). Colombin
is inodorous, very bitter, and perfectly neutral to vegetable colours. It melts at a
gentle heat. It dissolves but sparingly in cold water, alcohol, and ether, but imparts to
them a strong bitter taste. Boiling alcohol of specific gravity 0'835 dissolves from j>g

>.>

thf

1086 COLOMBO BOOT— COLOPHILENEL

to j^ of its weight of colombin. It diflsolvee to a small amoant in Tolatile oOa, and
more freely in potash, whence it ia precipitated by acids in its original state. Aoetie
acid dissolves it and deposits it in the crystaUine state on evaporation. Strong sol-
phnric add dissolves it with orange colour, gradnally fflntnging to deep red, and on
adding water to the solution, brown flakes are deposited. Solutions of colombin are
not precipitated by any metallic salts or by tincture of galls.

Colombin yields, according to the mean of Bodeckez^s analyses, 65*20 per cent. C and
6*98 H, the above fbrmula requiring 65*3 C, 6*7 H, and 29-0 O. It does not fonn any
definite compound, so that its atomic weight cannot be determined.

COXOMCBO SOOV. The root of Ooeeuhu palmatus. Bee., obtains eolomHn,
berberine, oolombic add (probably as oolombate d berbenne), besides starch, ooloor-
ing matter, &c The oolombic add and berbenne may perhaps be formed ficona co-
lombin by addition of the elements of ammonia (Bo decker) :

4CnH«0» + 2NH» « 2C*»H»N0» + C«H«0»» + SBH>.
ColoBdiiii. * Berberine. Cokmibte

acid.

The root acts with violence on the animal organism ; a grain of the diy extmet pre-
pared with ether and freed by water from &t and wax, killed a rabbit when intro-
duced into a wound. This active property appears to be due to the colombin.
(Buchner.)

OOIiOVBAni A constituent of icica resin (q.^.), containing, according to
Scribe (Compt. rend. ziz. 129), CH^O*. It is yellow, amorphous, easily soluble in
alcohol, melts above 100^ 0., is insoluble in aqueous alkalis, and reacts neutraL

OO&OynVB. C^^« or C*»H^, (H. Deville, Ann. Gh. Fhya. [2] Ixxr. 66;
[3] xxviL 85.) — ^A hydrocarbon polymeric with oil of turpentine, obtained by liiatJIKng
Ihat oil with strong sulphiuic add, or by distilling hydrate of turpentine-oil with
phosphoric anhydride. In either case, terebene (C'*fi") passes over first ; afterwards,
s»^ when the heat rises above 210^ C. colophene distils ; it is purified from sulphur and a

"^^ substance resembling colophony by repeated rectification, at last over antmionide of
potasdum. It may also be obtaiaed by the rapid distillation of coloj^ony, tiie
product being purified in like manner.

Colophene is an aromatic oil, colourless by transmitted lights and exhibiting bj
refiect4^ Ught a dark indigo-blue iridescence. Spedfic gravity, 0'940 at 9^0., 0-9394
at 25^. Boiling point between 310^ and 315°. Yaponr-dendty » 11*18 (probably
only twice as great as that of oil of tuipentine, tiierefore a 9*526). Befracting
power B 1*517 (Becquerel and Cahours), 1*5212 (Deville). It has no action on
polarised light.

Colophene absorbs ckiarine gas without evolution of hydrodiloric add, becoming
hot, and changing to a resin like colophony, which separates in vellow spherules from
its solution in absolute aloohoL If, when the absoiption of chlorine has ceased, the
psodnct be heated to fiision in the stream of chlorine, a lafge quantity of hydro-
chloric add is evolved, and Deville*s ehloroeolopkme >■ C'H'Kyl* is formed, vdiich how-
ever still contains a resin removable by alcohol, and when distilled, gives off* hydro-
chloric add, yields a distillate of colophene and hydrochloiate of colophene, and leaves
charcoal.

BydrochhnUe of Colophene, — Colophene absorbs hydrochloric add gas, with rise of
temperature, and acquires sn indigo-colour. The hydrochlorate gives up neari^ aJl
its hydrochloric add when treated with chalk, and when distilled with baryta, yields
Deville*s eohpkUene » C'H'', which does not exhibit the dichroism of colophene^
and has a refiracting power for light « 1-51 75. (Deville^ Becquerel, and Cahoara^
Pogg. Ann. li. 427-433.)

Colophene from Camphor. (Clans, J. pr. Chem. xxv. 266. — -When eamphw is
distilTed with an equal weight of iodine, hydriodic add is evolved, camphin passes over
at 180° C, and charcoal, iodine, campho-creosote and colophene remain behind (L 728)l
On increasing the heat, the two latter substances distil over as a bluish-green oil,
which Ib deprived of its creosote odour by agitation with potash, but cannot be ob-
tained quite pure, even by distillation over lime and finallj^ over potasdmn.

It is a thick, yellowish oil, with violet iridescence, having a hi^h boiling point, a
mild taste, and an odour of violets, and burning with a bright fhliginons flame. It is
perhi^ identical with colophene frmn oil of turpentine or from colophony.

It is not soluble in toater or in weak alcohol^ but dissolves in ether, oil of turpentine,
rock-oU, and camphine. When 2 drops of it are dissolved in 2 drachms of alcohol,
the solution, after agitation with animal charcoal, exhibits a fine daik blue colour
by refiected light

OOliOFBk&BVa. The hydrocarbon C^H" obtained from Deville's hydro-
chlorate of colophene {yid, eupj)

COLOPHOLIC ACID— COLOPHONY. 1087

OO&OVROIAC AOZD of Unyeidorben ; y-resin of Colophony of BeizeliiiB. Tlie
eoDstitaent of colophony which is least soluble in alcohol, and is produced by the
action of heat on pinic acid. It is therefore present in colophony in variable quantity,
according as that substance has been more or less heated during fusion; the darker
Tsrieties contain about one-tenth. Colopholic acid is said to be likewise produced
when pinic acid is distilled till a third of it has passed over.

Colopholic acid is brown,, sparingly soluble in alcohol of 67 per cent, more readily
in presence of pinic acid. It has a stronger afiSnity for bases tnan pinic acid; never-
theless the oolopholates exactly resemble the pinates,

COJbOraoVZO AOZIMI. The resinous adds, pinic^ pimaric, i^lvic and colo-
pholic, which are present in colophony.

COXOraoVITBi A variety of garnet^ so called from its brown colour, resinous
lustre, and easy fbribility. (See Gabmxt.)

OO&OFBOVOVa. C"H>"0. (Schiel, Ann. Gh.Phann. czv. 96).— An oil occurring
among the more volatile products of the dry distillation of colophony ; it ia separated
by frfustional distillation. It is colourless, mobile, highly refractive, of specific gravity
0'A4, boils at 97° C; vapour-density about 5'1. When heated above its boiling point
in a dose vessel, it turns brown, and emits an odonr of peppermint It mixes with
sulphuric add, and on addition of water, a green oil separates, having an odour of
thyme and rosemary. Hydrochloric acid acts in like manner ; nitric add converts it
into a resin. With potassium, it gives off gas, and is converted into a brown mass,
subsequently turning yellow.

00&09H0VT. Eosin, Colophomutn, Colopkane, Arcanton, Brai sec, Gtigenharg.
—The resinous substance which remains when turpentine or pine-resin is heated till
the water and volatile oil are expelled. It is for the most part a mixture of sevend
resinous adds, viz., pinio add (the a-resin of Berzelius), which forms the principal

5artt sylvic add (^resin), and coMpholic add (7-resin), sometimes also pimaric acid«
'hese acids, which are mixed in various proportions, are all isomeric, their common
formula being C"H'*0' or C**£P*0*. They are perhaps formed by oxidation of tur-
pentine oil:

2C»»H»« + 0' - C»H»0« + HK).

Ck)lophony is either pale yellow and transparent (C album) or brownish-yellow and
translucent (C commune), according to the degree of heat to which it has been ex-

red. By distillation with steam under a pressure of about ten atmospheres, it msr
obtained very nearly colourless (Bunt and Pochin's Patent, 1858, No. 926). It
has a vitreous lustre, is brittle in the cold, has a conchoidal fracture, and vields a
yellowish powder. Its specific gravity varies from 1*07 to 1'08. It is insoluble in
water, but dissolves easily in alcohol, ether, wood-spirit, and oils both fixed and
volatile. Bock-oil dissolves only a portion of it ; the undissolved part is said to be
identical with pinic add altered by the action of the air. Nitric add dissolves and
decomposes it at the same time.

Colophony, being a mixture of adds, unites withl)uses. The compounds which it
forms with the alkalis are soaps soluble in water. It is easily sapom'fied either by
caustic alkalis or by their carbonates.

Colophony softens at 69^ or 70° C. and melts at 135°. At a higher temperature
it gives off volatile oils, acquiring a darker colour, and yields colophoue add.
When qnickly heated in a retort, it distils partly undeoomposed, partly resolved into
gases, volatile oils, viz. Deville's terebene and colophene, and perhaps other hydro-
carbons, finidly vielding visdd oils, with a small reddue of carbonaeeotDs matter. When
the distillation is performed on the large scale in cast iron retorts, the gases evolved in
the first half of the distillation contain, besides the constituents of the air, 15 per
cent, carbonic anhydride, 11*5 carbonic oxide, 5*9 ethylene and tetrylene ; at a higher
temperature, the oxygen disappears, the prcmortion of carbonic anhydride incrrases,
and lastly a small quantity of marsh-gas is formed. The first portion of the liquid
distillate is a yellow, mobile, strong-smelling liquid, known in commerce as eseence of
rosin (irive essence, Hartessenjs) ; it yields by fractional distillation, first colophonone
(q, v.), and afterwards an optically indifferent camphene(L 724), boiling at 160° C,
having the odour and other properties of oil of turpentine, and perhaps identical with
Deville's terebene. At a later stase of the dry oistillation, a visad fiuorescent oil
passes over, called rosin-aU or paraffined, which, after being treated with quick-Ume,
corresponds in composition to the formula C**H^O. After rectification, it no longer ex-
hibits fiuorescence, and if again treated with lime, gives the formula C^K^*Q (Schiel,
Ann. Ch. Pharm. cxv. 96). At a red heat, colophony yields a mixture of gases burning
with a very bright flame, which it has been attempted, though without much success,
to use as an illuminating gas.

1088 COLORIMETER - COLOURING MATTERS.

Colophony is eztensiTelj used in making TanuBhes and eementa, in the cavIkiDg of
ships, in the preparation of plasters and ointments, and as a reducing agent in the
soldering of metals. Large quantities are oonsnmed in the mann&ctme of yellow
soap. A well known use of it is for oovering the bows of Tiolins, to prevent tlie bow
from slipping oyer the strings without producing vibration. Of the products obtained
b^ the dry distillation of colophony, tiie more volatile oil is used in place of turpentine-
oil, the more viscid rosin-oil for soap-making, and Ibr lubricating eartwheejs, &e.
(Handw. d. Chem. i [3] 160.)

COlbOXXMBTBB. An instrument for measuring the depth of colour in a liquid
by comparison with a standard liquid of the same tint. 'Ab comparison is made
either by varying the depth of the stratum of liquid under examination till it ezhibiiB
the same intensity of colour as the normal liquid, and then measuring the depth of
the stratum, — or by diluting the strongerK»>loured liquid with water, till equal oolnmn*
of the two exhibit the same depth of colour.

OOJMMIMm A colouring matter obtained by Bobiquet and Colin firom madder,
since shown to be impure alizarin.

dOIiOBTJt U ML The milk of mammalia secreted in the first few days after partu-
rition, before the access of milk-fever. It is distinguished horn oj^iinanr milk by con-
taining a larger amount of solid oonstitaents, also a larger proportion of hXj casein, and
milk-sugar. (See Mmc.)

OOXiOinu (See Light). — A table of oil painters' colours, with notices of their
chemical and artistical qualities, drawn up by W. Linton, is given in ZMs JHctionaiy
of ArtSf Manufactures, and Mines, vol. i p. 803 ; see also VktmU des Qmleurt pow
la Peinture a FEau et a VHmU, par. J. Lefort 12mo. Paris, 1865.

bOliOinUCire BKATTBBS. This term is usually restricted to coloured com-
pounds of ye^table or animal origin, sometimes^more especially to sudi as exist
ready formed in the bodies of plants and animals, or are easily formed from them by
natural processes, such as oxidation or fermentation. Accordingly, it would be applied
to such bodies as indigo, Indian yellow, and carmine, rather than to compounds like
aniline-purple or murexide, which are formed by complicated artificial processes. This
restriction of the term must not, however, be regarded as absolute, since many artificial
organic coloured compounds resemble the natural colouring matters in their most
essential properties, especially in those which render them available as dyes.

Colouring matters occur in all the organs of plants and animals. Many are obtained
from roots, as alkanet, turmeric, madder, &c. ; from the stems, as from sandal-wood,
log-wood, Brazil-wood, &c. : leaves, flowers, fruits, and seeds are also rich in colouring
matters. Of some insects, as the cochineal-insect, the entire substance is used as a
dye ; certain liquids of the animal organism, as the blood and bile, are also strongly
coloured. Colouring matters rarely exist either in ptlants or animals in the separate
state ; indeed their separation is oft^ a matter of considerable difficulty. Many do not
exist ready formed in plants, but are produced from originally colourless compounds
by oxidation or fermentation ; in some instances, also, by the action of oxygen in pve-
senee of alkalis.

Colouring matters are for the most part either red, yellow, or blue, the last being
the least numerous. Only one green colouring matter occors in nature, namely, the
chlorophyll of leaves.

Colouring matters have generally a saccharine and somewhat harsh taste ; they are
inodorous, some of them, as indigotin and alizarin, crystallise readily; others are of a
resinous character. Many are volatile, as alizarin ; but they must always be distilled
with caution, as a heat of 150^ C. is often sufficient to decompose thouL

All colouring matters are affected by light, mostly absorbing oxygen under its in-
fluence, and becoming more or less decolorised. The green colour of chlorophyll on
the contraiy requires the presence of light for its developments

Many colouring matters are soluble in water, others only in alcohol, ether, or vola-
tile oils ; in some cases, the presence of an acid facilitates the solution, although the
colouring matter may not actually possess basic properties, e.g. hsematosin, indigotin,
alizarin, putpurin ; others on the contrary, as carthamin and santalin, dissolve rndily
in alkalis.

The tint of colouring matters is modified in various degrees, and sometimes com-
pletely destroyed, by chemical reagents. The alkalis turn the naturally red colour of
litmus to blue, many vegetable blue colours to green, and the yellow of rhubarb or
turmeric to brown. The alkaline compounds of alizarin are of a rich violet colour,
though alizarin itself is reddish yellow. All colouring matters are decomposed by
concentrated alkalis.

Many metallic oxides, e.g, alumina and oxide of tin, form chemical compounds with
colouring matters. Such compounds are ealle<l 1 a k e a Many salts also, especially those

COLUMBITE ^ COMBUSTION. 1 089

of alumininm, iron, and tin, act upon colonring matters bo as to form componnda bj
means of which the colouring matter is fixed upon organic tissues; such substances
are called mordanta

Porous substances, especiaUj animal charcoal, absorb colouring matters without
decomposing them; thus, if an infusion of logwood be decolorised by filtration
through animal charcoal, the colouring matter may be recovered by treating the char-
coal with a weak alkaline ley.

All organic colouring matters are destroyed by chlorine in presence of water, the
action consisting, in most cases, of a direct oxidation of the colouring matter, by
oxygen set free by the decomposition of water. Sometimes, howeyer, the chlorine
takes hydrogen from the colouring matter itself and partly replaces it.

Oxygen in the nascent state hkewise acts as a decolorising agent, when derived
from oSier sources ; thus, peroxide of hydrogen quickly destroys the colour of organic
bodies, and indigo is bleached by nitrous acid.

Sulphurous acid decomposes and bleaches many colouring matters, sometimes by
abstracting oxygen, sometimes by uniting with the colouring matter and forming a
colourless compound. It is a valuable bleaching agent in many cases, especially for
silk and wool, Dccause it destroys the colouring matter without acting on the tissue,
whereas chlorine would act very iiyuriously upon it Fruit stains are easily removed
from linen by washing with a weak solution of sulphurous acid, or by holding the
moistened doth over burning sulphur ; care must be taken, however, to wash it well
afterwards, or the sulphuric acid produced in the reaction will destroy the fibre.

Many reducing agents, such as nascent hydrogen, sulphydric acid, alkaline sul-
phides, ferrous salts, &c, decolorise colouring matters in such a manner that the colour
IS restored by mere exposure to the air; fiius, blue indigo is converted into white
indigo by the action of these bodies, but recovers its blue colour by atmospheric oxi-
dation. The action consists either in a direct deoxidation of the colouring matter, or
in a combination of the colouring matter with hydrogen derived from the decomposi-
tion of water. Thus white indigo, CH^O, is formed from blue indigo, OH^NO, bv
addition of 1 at hydrogen. ( TraiiS de CMmie ffinSraUf par Pelause et Frimy, 2'** ed.
V. 492 ; Uri^a Dictumary of ArU^ Mant^actures, and Mines, L 806.)

See NiOBiTB.

or WZOBZVBK. A metal originally discovered in oolumbite from
Massachusetts, and since shown to exist in the tantaUte (or rather columbite) of Boden-
mais in Bavaria, also in Samarskite, pyrochlore, wohlerite, ennenite, and a variety of
pitchblende from Satersdalen in Norway. It was discovered by Hatchett in 1801.
WoUaston erroneously supposed it to be identical with tantalum, the metal discovered a
short time afterwards by Ekebeig in Finland tantalite. This opinion was long received
as correct, and columbium is even now spoken of in most Manuals of Chemistry as
identical with tantalum ; but the researches of H. Rose have shown that this supposed
identity does not exist. In short, columbium is identical, not with tantalum, but with
Bose's niobium {q. v,)

COMBUSTJIOV. This term properly denotes the development of light and heat
accompanying chemical combination. It is sometimes used as synonymous with tn-
ftammaiumj which, however, is better restricted to those cases of combustion in which
the products are gaseous, in other words, in which fiame is produced. lanition is the
incandescence of a body produced by extriosic means, without change of its chemical
constitution.

The earlier chemists, feeling daily the necessity of fire to human existence, and
astonished at the changes which this power seemed to produce in charcoal, sulphur,
the metals, and other bodies, regarded combustion as the grand and essential pheno-
menon of chemistry. At the beginning of the eighteenth century, S tah 1, of Prussia, by
applying the views of Albertus Magnus and Becher respecting combustion to the whole
coUection of facts discovered bv himself and others, and uniting them into a connected
whole, laid the foundation of the first system of chemistir. This system received the
name of the "Phlogistic Theory," because Stahl assumed that all combustible bodies
contain one and the same principle of combustion called Fhloguton, the escape of this
substance from a heated combustible body being supposed to produce the phenomenon
of combustion or fire, and its addition to a burnt body to restore the combustibility of
that body : thus, phosphorus was regarded as a compound of phlogiston and phosphorio
add ; lead of phlogiston and lead-euth or calx of lead, the substance now called oxide
of lead. When a calx or earth was reduced to the metallic state by heating it with
charcoal (a body rich in phlogiston), it was supposed that the burnt body took phlo-
giston from the charcoal, and was thus restorea to the combustible state.

An obvious defect of the phlogistic theory was that it took no account of the essen-
tial part which the air plays in all ordinary cases of combustion, a fact suggested by

Vol. I. 4 A

1090 COMBUSTION.

common experience, and fiilly demonstrated by the discoreries of Scbeele, Carendisli,
nnd Priestley. Moreover it had long been known that many combustible bodies, the
metals for example, do not lose, but gain weight when burnt ; and towards the end oi
the eighteenth century Lavoisier showed, by experiments on oombustion, made with a
degree of accuracy in the determination of weights and yolnmea, quite unknown before
his time, that whenerer a body bums in the air or in oxygen gas, the oxygen enters
into combination with the burning body, and the weight of Uie prodnet is exactly
equal to the sum of the weights of the combustible body burnt and of the aayge^ oon-
Bumed. It was also shown that^ in the reduction of a metal from, its calx (or oxide) by
charcoal, the latter body takes oxygen from the calx and leares the metal in the free
state. In short, wherever the phlogistic theory supposed that phlogiston was remored
from a body, Lavoisier^s experiments showed that oxygen was taken up, and wherever,
according to the fonner theory, phlogiston was supposed to be added, Lavoisier showed
that oxygen was removed. This system of chemistry, called the " Antiphlogistic Theory,'*
did nott however, meet with immediate acceptation from the majority of cbemiste,
the advocates of the phlogistic system maintaining that the increase of weight of
metals and other bodies in burning might be explained by abecribing to phlogiston a
principle of 1 e vi ty, — in other wor£, a tendency to recede from the earth itrit^^ of fsU*
ing towards it, as ponderable bodies do. Such an assumption, however improbaUe in
itself, would of course suffice for its immediate puipose ; that is to say, of acoonnting
for the increase in weight of a body by loss of phlogiston ; but the explanation thus
afforded took no account oi the oxygen, which Lavoisier had shown to be abstracted
from the air and added to the burning body. Accordingly, as experiments were multi-
pi iod, and it was shown that in all cases of combustion, the weight of the product was
equal to the weights of the combining bodies taken together, the phlogistic theory
gradually lost its hold on the minds of chemists, and was ultimately abandoned.

At the time of Lavoisier, attention was chiefly directed to oombustions taking place
in the air or in oxygen gas, and to the reduction of metallic oxides by hydrogen or
carbon. Chlorine aUo, vien called oxymuriatie acid, was supposed to contain oxrgen ;
bromine and iodine were not known. Accordingly it was natural that oxygen uonld
be regarded as essentially the supporter of combustion, the bodies which burned
in it being called combustibles. Afterwards, when chlorine was shown to be an ele-
mentaiy substance, and when bromine and iodine were discovered, and metals, &e^
were found to bum in their vapours, the term supporter of combustion was extended
to all substances capable of forming vapours in which others can bum ; thus, when
copper-foil bums in sulphur vapour, the sulphur may be called the supporter, and the
copper the combustible. But since the same substance may act sometimes as a com-
bust ible, sometimes as a so-called supporter, — e.ff. sulphur as a combustible with
oxygen, as a supporter with metals, — the distinction has graduaUy become obsolete.

The development of heat and light in combustion was attributed, on Stahl's theory,
to the escape of phlogiston. The antiphlogistic theoiy, by dwelling chiefly on the
ponderable substance produced by the combustion, and the relation between its
weight and those of the combining bodies, tended rather to divert attention from the
attendant phenomena of light and heat, and, indeed, was somewhat reproached bv the
adherents of the older theory for not rendering a sufficient account of those pheno-
mena. Lavoisier attributed the heat accompanying oombnstion to the aepamtion of
the latent heat of the oxygen gas ; and attempts have been made to extena this mode
of explanation to all cases of chemical combination, in ?^ch gaseous or liquid sub'
stances pass to the solid state. This, however, will not account satisfactorily for the
noTts intense evolution of heat in combustions and other combinatioiis : for the latent
heat of gases and liquids is email in comparison with such developments of heat.
Moreover, in many instances, the combination is not attended with condensation ; r.^.
in the combustion of charcoal or sulphur in oxygen gas, and of hydrogen in chlorine
gas; or again, gaseous products are formed from solid bodies, great heat being at the
same time evolved, as in the explosion of nitre with charcoal, &c.

Neither can the heat of combustion be generally attributed to diminution of specific
heat in the resulting compound ; for in most cases the atoms of simple substances
retain their ioriginiJ specific heat when they enter into combination (see Atoxic
Wbiorts, i. 472, and Hbat). In other cases, on the contrary, combination is attended
with an actual increase of specific heat, so that the result would be a production of
cold, if heat were not developed from some other cause.

Thus, 1 lb. of hydrogen gas, of specific heat 3*293, combines, under the most violent

evolution of heat^ with 8 lbs. of oxygen of specific heat 0*236, producing 9 lbs. of

, ' , , . /3•298-^8. 0*236\
water of specific heat 1*000, whereas calculation gjives I ^ 1 «■ 0*576 as

the mean of the two specific heats. If then water had a specific heat « 0*676, the
quantity of sensible heat in the hydrogen and oxygen gases together would be exactlj

COMBUSTION. 1091

Bufficient to bring the vat«r formed to the same temperatare as that of the gases them-
selres ; bnt since the actual specific heat of water is 1*000, the quantity of sensible
heat in the gases is not sufficient for this purpose ; and if heat were not developed
from some other cause during the combination of oirgen and hydrogen, the water pro-
duced would be much colder than the two gases before combination.

Benelius, on reyiewing these dicumstances, justly concluded that all such explana-
tions of the origin of fire are defectiya He supposed that, in erery chemical com-
bination, there is a neutralisation of opposite electricities, and that this neutralisation
produces the flame or fire, in the same way as it produces fire in the discharges of the
Leyden phial and the roltaic battery, and in thunder. He admitted, however, that
this hvpothesiti does not a£fbrd a satisfactory explanation of the union of the atoms
after tlie discharge has taken place. (See Chbkigal Affinitt, i. 865.)

A more satisfactory explanation is that adyanced by Sir Humphry Bavy, viz. that
the immediate cause of the phenomena of heat is motion, and that the laws of its com-
munication are precisely the same as the laws of the communication of motion ; that
in fact, these phenomena are analogous to those of light, as expounded by the undu-
latory theory. On this principle we may explain the great heat produced by fridtion,
and in explosions, such as those of oxide of chlorine, and chloride of nitix>gen, eases in
which heat and light are copiously displayed, at the same time that great enlargement
of volume takes pmce, rendering the idea of the extrusion of a calorific fiuid altogether
inadmissible. Whenever the diemical forces which determine either composition or
decomposition are energetically exercised, the phenomena of combustion, which axe
incandescence with a change of properties, are exhibited. In all cases, the heat and
light depend on the same cause, and merely indicate the energy and rapidity of the
reciproaU chemical attractions. No peculiar substance or phlogistic essence is neces-
sary to the production of fire ; but it is a general result oi the actions of any bodies
possessed of energetic chemical attractions or different electrical relations ; and it is
produced in all cases in which an intense and violent motion may be conceiyed to be
communicated to the particles of bodies.

We now proceed to consider the circumstances which fiivour or retard combustion
and determine the nature of fiame, confining our attention cbiefiy to cases of combus-
tion in the air. For the greater part of our knowledge on this subject we are indebted
to the admirable researches of Sir Humphry Davy (Phil. Trans. 1817, pp. 45 and
77), which led him to the invention of the Miner*s Safety-lamp. The subject may be
treated under the following heads : —

1. The temperature and other conditions required to infiame different bodies.

2. The nature of fiame and the relation between the light and heat which compose it.

3. The causes which modify and extinguish combustion.

The quantities of heat evolved in the combustion of different bodies will be more
conveniently considered in the article Hsa.t (^. v.)

I. Conditions of Inflammability,

But few substances are capable of combining with oxygen at ordinary temperatures,
and those which exhibit this capacity lose it at lower temperatures. The temperature
required to brins; about the combination of oxygen with any substance, the burning
pointy as it may be called, is different, not only for different substances, but even for the
same substance, according as the combustion is to take place rapidly or slowly. Thus,
phosphorus combines slowly with oxygen, or exhibits slow eornbustion at 25^ 0. (77^ F.),
but aoes not enter into rapid combustion till raised to 60° G. (1 40° F.) Charcoal like-
wise bums slowly below a red heat Sulphur takes fire in the air at about 285° C.
(550° F.) Most other elementary bodies require to be heated to redness before they
take fire in the air or in oxygen gas. Several organo-metallic bodies, as zinc-methyl,
cacodyl, and some of the antimonides of ethyl and methyl, take fire immediately on
exposure to the air. Nitrogen cannot be made to unite with oxygen by elevation of
temperature, except under peculiar circumstances ; chlorine, bromine, and iodine not
at all by heat, only by substitution.

Chlorine unites rapidly with hydrogen at ordinary temperatures, and under the in-
fluence of direct sunshine, produces a violent explosion. Many metals also bum when
introduced into chlorine at ordinary temperatures. Bromine and iodine unite rapidly
with phosphorus and with several metals, especially if in the finely divided state, at
ordinary temperatures ; but in a tube coolea with ice, phosphorus and iodine may be
brought together without acting on each other.

Sulphur unites with many metals at a red heat, the combination being attended
with vivid incandescence, e.g. with iron and copper.

The relative infiammability of different bodies in common air may be approximately
estimated by fusing a series of globules of different sizes at the ends of thin iron wires,

4 a2

1092 COMBUSTION.

and lighting a number of rery smaU flames of different snbetaneea, but all of tba
aame size. A globule ^j^ of an inch in diameter brought near an oil flame ^cian iDch
in diameter wiU, if oolo, extinguish it at the distance of a diameter. The aiie of tha
clobule required to extinguish the flame will afford a rough measure of the xelaliTe
inflammability of the burning body. The oombostibility of different gases may also be
approximately measured by the sizes of the masses of heated bodies required to set
them on fire. An iron wire j^ of an inch thick at a cheixy-red heat will inflame hy*
drogen, but not olefiant gas, which, however, is kindled by a wire } of an inch thidL
at ue same degree of heat. A wire ^ of an inch thick must be heated to white-
ness to inflame hydrogen, but it will kindle phosphoretted hydrogen at a low red heat.
Carbonic oxide takes fire in the air by contact with an iron wire at a dull red heat ;
but the fire-damp of mines is not kindled by a wire ^ of an inch thick heated «vai
to whiteness. (Dary.)

Compression of the air does not appear to facilitate combustion, unless it takes plaee
rapidly, and is consequently attended with considerable evolution of heat. Thdnaid,
however, found that wood does not take fire in oxygen gas under the ordinary pres-
snrif at temperatures below 360^ C, but under a pressure of 2*6 met. oombostion
begins at 252°. On the other hand, phosphorus in oxygen gas or common air exhibits
slow combustion at a temperature which is lower in proportion as the gas or air is
more rarefied ; and a mixture of oxygen and phosphoretted hydrogen, which, under the
ordinary atmospheric pressure, requires a temperature of 116-7° C. to inflame it, does
not take fire at 118° when the density is increased to fifteen times its former amount ;
but if the mixture, contained in an inclined glass tube standing over mercnxy, be rarefied
by setting the tube upright, combustion takes place at 20°. Dobereiner likewise
found (J. pr. Chem. i. 114) that a mixture of equal measures of oxygen, hydrogen, and
nitrogen gases contained in a detonating tube was always ex{doded by the electric
spark, if the tube were open at the bottom, or merely closed with water ; but not
always when the tube was closed by a cork, — the compression appearing to offer an
obstacle to the continuation of the combustion.

The combination of oxygen with inflammable gases and vapours is greatly facili-
tated by contact with platinum and certain other metals, the effect depending partly
on the power possessed by the metal of condensing the gases on its snr&oe or within
its pores, if it be in the spongy or finely divided state, i^rtly on a polarised condition
of the molecules (see Contact- actiom). When a clean plate or wire of platinum is
immersed in a mixture of oxygen (or common air) and a combustible gas, a slow com-
bustion takes place at first, by which- the temperature of the solid body is raised, —
and consequently, the process of combustion is not only sustained but actually ac-
celerated ; and at length the temperature of the solid body may be so much raised as
to give rise to rapid combustion. The larger the sui&ce of the metal, the mors
powerful is its action.

It was observed by Sir H. Davy that a mixture of oxyg^i gas or common air with
hydrogen, carbonic oxide, olefiant gas, cyanogen, or vapour of hydrocyanic acid,
alcohol, ether, rock-oil, or oil of turpentine, is brought into a state of slow combustion
by contact with thin platinum foil or a spiral of platinum wire heated to a tempe-
rature short of redness, — ^that the heat thus developed brings the platinum to a state
of bright ignition, — and that, with certain gases, rapid combustion at length ensoea.
He likewise found, as had been previously observed by Grotthus, that the mixture of
oxygen and hydrogen gases heated not quite to redness in a glass tube, psniied in a
few minutes into the state of combination and formed water, without senmble evolu-
tion of light and heat, Erman showed that the platinum wire requires a teiiq)eratun
of only 50° to 61° C. in order to induce the combination of oxygen and hydrogen.
E. Davy found that platinum-black (platinum in a state of division still finer ^an that
of spongy platinum), moistened with alcohol, became incandescent in the air .and
induced combustion of the alcohol Finally, Dobereiner discovered that freshly
ignited spongy platinum (as it remains after ignition of ammonio-chloride of plati-
num) excites, even in th,e cold, first the slow, and then, under fiivourable circum-
stances, the rapid combustion of a mixture of hydrogen gas with oxygen or atmo-
spheric air. It appears from the experiments of Dobereiner, Pleischl, Dulong; and
Th^nard, that this property is possessed (though in a less degree, so that in most
cases the temperature must be raised, though never to the burning point) by othej
solid substances, both metallic and non-metallic, e.y. palladium, nuKlium, iridium,
osmium, gold, silver, cobalt, nickel, charcoal, pumioe-stone, porcelain, gjlass, rode
crystal, and fiuor-spar.

These effects may be shown in either of the following ways :

1. Spongy platinum fastened to the end of a wire is suspended within a glass flask,
which IS then exhausted of air and filled with the mixture of oxygen and the com-
bustible gas. — 2. The gaseous mixture is contained in a vessel 8tan<Ung over mercuiy.

COMBUSTION. 1093

uid the spcngy platmum fastened to a wire is pushed up into it : or a piece of it is
simply passed up hy itself through the mercury into the gas. The platinum is best
prepared for this purpose by forming a mixture of moistened clay and ammonio-
chloride of platinum, or of sal-ammoniac and spongy platinum, into baUs, and heating
them gently : the balls thus prepared may be used several times. — 3. The mixture of
oxygen or air with the combustible gas is directed on the spongy platinum contained
in a glass dish or a funnel. — 4. The spongy platinum is attached to a fine platinum
wire (for this purpose the platinum wire may be wound into a spiral, or a KKwe net
may be made of it ; and upon this a portion of ammonio-chloride of platinum, made
into a thick paste with a small <^uantity of water, may be fastened, and then ignited) ;
a stream of uie combustible gas is then to be directed upon it : the gas is thus brought
in contact with the platinum after^bst mixing with the air. — 6. Fine platinum wire
is wound from three to eight tijnes in a spiral form round a thin glass rod or an iron
wire, the turns of the spiral being kept yery close together: it is then removed, and
inserted by its lower extremity into tne end of a glass tube, firom which the combus-
tible gas issues into the air ; — or the lower turns of the spiral are fixed round the wick
of a lamp fed with a combustible and volatile liauid, such as alcohol, ether, or a vola-
tile oil ; or again, the end of the wire is inserted into the middle of the wick or into a
capillaiy tabs into which the liquid rises. This arrangement serves for the lamp
without fiame or glotO'lamp (i. 74). It is usual to set fire to the vapour, and let it
bum till the platinum wire becomes red-hot ; then, when the fiame is blown out, the
wire continues to glow. — 6. A triangle of fine platinum foil is cemented by one of its
comers into a thin ^lass rod, which serves for a handle, and held over the aperture (in
some cases after being heated) from which the combustible gas issues into the air, —
or else over a volatile liquid, such as alcohol or ether. The greater the purity of the
ammonio-chloride, the more efficient is the spongy platinum prepared from it. As
with platinum, so also with the other metals above named.

Effect of meehanical dimsion, — ^Many finely divided substances are capable of burn-
ing at comparatively low temperatures, as shown by the following experiments : —
"Wlien oxide of nickel, cobalt, or iron is reduced by hydrogen gas at a temperature of
about 360^ C, or not quite amounting to redness, or when oxaUte of iron is heated in
dose vessels not quite to redness, whereby the iron is reduced, the metallic powder thus
obtained bums with a glimmering light on being exposed to the air at ordinary tem-
peratures. If the heat during the reduction be raised to redness, or if the metal re-
duced at a heat below redness be afterwards ignited in hydrogen gas, it will no longer
exhibit spontaneous combustibility, possibly, because the metal when thus, strongly
heated agglomerates in denser masses : but if a quantity of alumina or glucina be mixed
with the metallic oxide, — ^by mixing the solution with that of the s^t of alumina or
glucina, and precipitating by an alkali, — the metal, when reduced by hydrogen, even at
a red heat (provided the heat has not been very intense), takes fire on exposure to
the air, as readily as that which has been reduced at a lower temperature, — possibly,
because the interposition of the earths, which are not reduced by the hydrogen, pre-
vents the particles of metal from welding together. Copper reduced by hydrogen gas
at a very moderate heat was likewise observed on one occasion to become covered, on
exposure, with a film of oxide, without however taking fire. Iron reduced by hydrogen
gas absorbs several times its volume of carbonic acid gas ; it thereby loses itsinfiamma-
bility, which, however, it recovers by being again heated in hydrogen gas. This pro-
perty of spontaneous inflammability may be explained in two different ways : 1. The
metal reduced "by hvdroeen retains a portion of this gas enclosed among its particles ;
when exposed to the air, it induces combination between this substance and the
oxygen of the air (after the manner of Dobereiner's process), and the great heat
evolved in this combination causes the metal to take fire. Against this, however, it
may be alleged that iron reduced from the oxalate cannot contain hydrogen gas en-
closed amongst its particles (it may, however, contain carbonic oxide) ; and even when
the metal is thrown into water, and the water driven off by evaporation, spon-
taneous combustion is still produced by contact of air. — 2. The metal when exposed
to the air absorbs the air mechanically, just as any porous body would do (and pos-
sibly it may absorb oxygen with peculiar avidity) ; and the heat developed by this
mechanical absorption gives rise to the combustion. If the metal has been preriously
saturated with carbonic acid gas, of which perhaps it absorbs a larger quantity than
of oxygen, it does not become heated by contact with the air (Magnus). Wohler
likewise found that intimate mixtures of charcoal and reduced met&Ls oit«n possess
theproperty of taking fire at a red heat.

l^e spontaneous combustion of other porous substances, such as charcoal-powder or
small coal, and especially of masses of tow, cotton, or rags saturated with oil, takes place
in a similar manner. The substance absorbs and condenses the air within its pores ;
oxidation then commences immediately and raises the temperature, which again

10&4 COMBUSTION.

mectAent&B the oxidation; and tliiui the process goes on with oontimullj
rapidity, till at length the mass bunts into flame. The low conducting power of
a porous mass greatly facilitates the combustion, by preventing the dinipatioa of the
heat generated. Instances are known of olive oil igniting upon sawdust; of greasy
rags from butter, heaped together, taking fire within a period of twenty>fi>ur houn ; oi
the spontaneous combustion of tape-measures, which are covered with an oil-Taraish,
when heaped together ; and even of an oil-skin umbreUa put away in a damp states
The presence of moisture greatly promotes the spontaneous ignitum of porous materials,
such as hay or coal-dust, the water probably supplying oxygen to the combostiUe
matter. (See Graham' s Bepart on the cauae of tie fire intke** Amaum^^ Cliem. Soc.
On. J.-T. 34,)

IL l^aiwre of FUms,

The fire which accompanies the process of combustion appears either as Glow at
Incandeeeence, when the buminsr body does not become gaseous before combustion, or
as FlaiHff when the burning body is previously converted into gas or v^iour. In the
former case, the heat evolved at the surface of contact of the oxygen and the com-
bustible body, chareoal or iron for example, heats the body and causes it to glow with
various degrees of brightness, according to the temperature. Feebly Rowing coals
emit a dull red light (ckerry'red heat or dull red heat) ; when more stzongly heated,
they emit a yellowish-red light (bright or full red heat) : at still higher temperatures,
a yellow light {dull or oommencinff white heat) ; then a yellowish, then a greemsh, and
lastly a bluish-white, intensely dawiling light {bright, fully or daexUng wuU haii\

VHien the combustible body is in the gaseous foim, either originally or in conse-
quence of the heat required to set it on fire, the mixture of this gas with the oxygen
and the products of the combustion constitutes flame, which is, in fiicti gaseous matter
heated to incandescence. If the combustible gas or vapour, and the oo^gen or air ars
uniformly mixed before ignition, the combustion takes the form of an expkxdon, com*
bination taking place at once throughout the whole mass of raaeons matter, which conse-
quently appears equally luminous uiroughouL A similar ^ect takes place when a com-
bustible substance, such as sulphur or charcoal, is intimately mixed with a nitrate,
chlorate, or other solid substance which readily gives up oxygen : if the temperature of
such a mixture be raised to the burning point at one spot by friction, percussion, oc
the contact of a hot body, the ignition of the first few particles raises the temperature
of the next, and then the action is propagated in an inappreciably short qiace of time
throughout the whole mass, producing a sudden and violent evolution of gas, occupying
many thousand times Uie volume of the original solid mixturs. The noise attmding
the explosion arises from the violent concussion of the sunounding air produced by
the sudden expansion of the burning gases.

But when the combustible gas or vapour issues from an orifice or a wick into the
air, or into an atmosphere of oxygen, the combustion takes place ffradually at the
surface of contact of the two gases, and a fiame is produced, consisting of an inner
dark and less heated space filled with the combustible gas, and a glowing envelope
marking the boundary at which the combustible gas and the oxygen come in contact
and unite. That such is really the structure of fiame may be shown by pliM^wg ^
piece of phosphorus on the wick of a burning spirit lamp, tne phosphorus not taking
fire tin it is pushed outwards. If a piece of phosphorus be placed on a wooden
support in the middle of a basin filled with alcohol, and the alcohol be set on fire, the
phosphorus melts, but does not take fire till the alcohol is burnt away or extinguished,
or tiU the fiame is blown on one side, or air directed upon the phoephorus by means
of the blowpipe. In a similar manner, a lighted candle will go out when plaoed in
the midst of an alcohol flame.

The brightness or illuminating povoer of fiame depends, not only on the degree of
heat, but likewise on the presence or absence of solid particles which may act as
radiant points. A flame containing no such particles emits but a feeble lights even if
its temperature is the highest possible — the flame of hydrogen gas, for example. But
in flames which do contain sobd particles, the brightness increases with the tempera-
ture to which these particles are raised. Solid particles in a flame sometimes arise
from the combination of the combustible body with oxygen, e, g. phosphoric add or
oxide of sine in the combustion of phosphorus or zinc ; sometimes, when the burning
body is an organic hydrocarbon in the gaseous state, they consist of particles of
carbon in the form of soot, separated in the interior of the flame by the heat of the
burning envelope. A dull flame becomes brighter by the introduction of a solid body
in a finely divided state.

The foUowbg substances give a dull fiame : hydrogen gas, carbonic oxide gas, sul-

COMBUSTION. 1095

phvr, Beleninm, arsenic, alcohol — and likewise coal-gas wlien it is mixed with a
iiafficieQt qnantitj of air to cause it to burn without deposition of soot : phosphorus
also boms with a dull flame in chlorine gas, because the chloride of ^osphorus, which
is the product of the combustion, remains in the gaseous state (H. Dayj). When a
spiral of platinimi wire or a piece of asbestos is hM in either of these flames, or some
powdered oxide of sine thrown into it, the solid matter immediately becomes white,
and emits a vivid light (H. Davy). Paper soaked in solution of chloride of calcium
and burnt in the flame of a spirit lamp, leaves a white network of ashes, which, when
held in the feeblest alcohol flame, emits a brilliant light (Talbot, Phil. Mag. [3] iii.
114.)

If alcohol vapour be projected from one set of tubes, and oxygen gas from another
set, upon a b^ of quicklime, having a stem by which it is listened to a wire, the
alcoh(M burning in the oxygen gas heats the ball to the most dazzling whiteness ; so
that the light, when reflected by a concave mirror placed behind it, is plainly visible
at the distance of 68 miles. Zirconia gives a light somewhat less powerful than that
of lime; that produced by magnesia is onl^ half as strong. (Brum m on d, Ed. J.
of Sc. 5, 319.) By the oxy-hydrogen blowpipe (i 613) lime is rendered much more
brightly luminous than by alcohol and oxygen gas. Supposing the intensity of light
of a wax candle ■- 1, that emitted by a cylinder of lime whose circumference is one-
fifth of that of the flame of the candle, is equal to 153 when it is i^ted by the oxy-
hydrogen flame ; to 76, in the flame of ether and oxygen ; to 69, in that of alcohol
and oxygen; and to 19, in that of coal-gas and oxygen* Unbumt chalk, white day,
and magnesia, give much less light than burnt chalk.

A bright fiaiM is produced by the following bodies : —

1. Those which in combination with oxygen form a solid compound : phosphorus,
potassium, antimony, bismuth, zinc, and most other metals. (Davy.)

2. Compounds containing carbon, from which a portion of the carbon is separated
in the form of soot, by the heat produced at the part where the combustion actually takes
plaoe, the separated carbon being first brought to a state of vivid incandescence, and
subsequently burnt when it comes in contact with oxygen. This is the case with
marsh-gas, olefiant gas, ether, volatile oils, fats, resins, &c. (H. Davy). The flame of
alcohol may likewise be rendered bright by the presence of any substance which
causes the carbon to separate from it Thus, chlorine ^ mixed with the flame of
alcohol increases its luminosity, because, by combining with the hydrogen, it causes a
deposition of solid carbon. Vapour of dioxide of osmium likewise gives luminosity
to the flame of alcohol, by giving up osmium and separating carbon from the alcohol.
To produce this effect, a piece of osmium is laid on the edge of a piece of platinum-
fbil, and the foil held over the alcohol fiame, so that the osmium may bum, and the
vapours of the oxide may mix with the va{)our of alcohol (Berzelius). The flame
of hydrt^en or marsh-gas may be rendered bright by passing the gas through coal-tar
naphtha, rock-oil, or some other volatile hydrooirbon, the vapour of which then mixes
with the gas and brightens the flame by the separation of its carbon.

On the contrary, by mixing a jet of carbonaceous gas or vapour with oxygen, as in
Bunsen's gaa-bumer, in which air is admitted just above the point where the stream
of gas enters the burner, so that the gas and air become well mixed before they reach
the orifice, a complete combustion of the carbon is obtained, and only gaseous products
are formed, the result being a very hot smokeless flame of feeble luminosity. A
similar flame is obtained by laying a sheet of wire-gauze on the top of the chimney
of an Aigand gas-burner, and setting fire to the cas above the gauze. The gas then
becomes well mixed with air in passing up the chimney, and the carbon is completely
burned as before.

The more slowly a carbonaceous substance is burned, the greater is the quantity of
carbon separated from it ; the brightness of the fiame is, however, diminished in the
same proportion, because the particles of carbon are less strongly heated. On the
contrary, the quicker the combustion, the smaller is the quantity of carbon separated ;
but the temperature to which it is raised is so much the higher, and consequently it
emits a brighter light

The flame of highly carbonised substances, such as a wax or tallow candle, consists
of four parts, as represented in flg. 129. a, a dark inner eonf, surrounding the wick,
and consisting of tne combustible gas and vapour issuing therefrom, mixed with atmo-
spheric nitrogen and the products of combustion, viz. water and the oxides of carbon ;
bf a light blue z<me at the bottom of the flame, and reaching a little way up the inner
cone. In this part, the combustible matter of the inner cone comes in contact with
the oxygen of the air not vet rarefied by the heat, and is completely burned just as in
the inner blowpipe-fiame (i. 613), producing a light of the same bright blue colour.
c, a highly luminous cone surroundmgthe dark inner cone. In this part, the supply of
oxygen is not sufficient) excepting at the outer surface, for the complete combustion

I0B6 COMBUSTION.

of tb* orbon, which tl tiierefbre lepuated in i
fltroQgly beil«d by the combmrtion,
F\g. 1 29. body be iDtroduced into the flsme, these psrticlee of oibon an depoeil«d
u BOot. d, the inanlit, a feebly lomiDoru, yellowish cone narnmnduw tho
entire fl&me, excepting jnet at the bortom, tai eonsistiiig of atmospheric
air heated to iDcaDdesceDce, and mixad with the final prodDcte of tbe
combnstdon. This part of the €ame it ofteo eonfoiuided with the blue
zone, from vhich, however, it is leally distiDct. The beat mode of ob-
BGrring it ia to cut oiU a piece of cardboard of Baarly the shape of the
flame, and hold it at such a distance from the eye as jost to hide the lami-

The flame of on Aigand lamp, which is sappUed with air within aa writ
a> withont, may be compared to the flame c^ an ordinary lamp or eamlla
flattened oat, and then bent into a erlinder. It contains the same paiti
'■ as the conical flame, bat from the form of the wick, the daik lone is ne-
cessarily very thin.
The compoaition of the flsme of wax and tallow bnmii^ from a wieJc
> has been *eeiirat«ly investigated by Hilsard (Ann. Cb. Fhann. xdi
129; Jahreab. <i Chem. liSi, p. S87). The lamp used in the experi-
ments coniiited of a shallow cylinder coDtaining tbe tad, and having in
ila axis a gls™ tube, over the npper end of which the i^lindrieal wick was
drawn. Throogb this tabe, which was capable of iiliding up and down,
a narrower tnbe connect«d at itj lower end with an aspirator passed
upwards into the &Hme. This narrow tube was attached to the enter tnbe
by means of a caoutchooe connecter, in soeh a manner that no air eoold
psm throti$;h the vide tube into the flame. By this arrangement, the gasM eonld be
collected at any required height in the flame ; they then passed through a seriea of
eoDilensen, and finally into a ^asa tube in which they were sealed up for examiualion.
In the fallowing table, the compoaition of tbe gaaes at difllerent heighta (in nulH-
metres) above ( + ) and below ( - ) the edge of the wick is given in percentages by
volume ; the symbol CE' inclodes etJiylene and tbe hydrocarbons polymeric with it.
X denotes the weight of liijuid and solid matter condensed from a litre of the flamB-

Qmpotitiim of Was and TaUow fittmt*.

B«r.uii»w FUn... 1 wtiFuw. 1

»■

CO.,

CO.

CH.

H. il>

'■

«.

CO.

dH'

e...

»■

0-lt

O'M

Rrt«

lO-M

Itii

IIS

4-00

ISO

l-M

•■a
;

otn

Is
li

a-s»

»«s

I9-M>
WW

14 n

aa-a

SflT

*»i

»7«

7-flO
S-97

The large qoanti^ of nitrogen in tbe interior of the flame aroie from the circnm-
stance, that the air entered the flame in a nearly horizontal direction, eepeeially at the
lower part. The proportion of nitrogen is a minimum at 2mm. above the edge of the
wick, chiefly because the greater heat and increasing amount of deoo^toaition in this
part of the fiame produce a larger amonnt of permanent gases. The quantity of
earbonio anhydride is nearly invenely proportional to that of the hydroearbona, C*H^.
YHieB the nitrogen is deducted, the sums of the amoonts of carbonic anhydride, ethy-
lene, &c., and carbonic oxide are needy constant. Tbe total quantify at these three
gases appears to niter but slightly from the bottom of the flame to a height of Tmm. or
8mm 1 at a greater height, it appean to inccewM, in oonsequenee of the exeeas (hT the
products of oxidation.

The inner oone of the flame contains t^e unbnmt gaaes isming from the wick,

COMBUSTION.

1097

e alwajB pre-
Fig. 130.

mixed with atmospheric nitiogen and carbonic oxide, earbonio odd, and water, pro-
daced by the combuation going on in tie ooter cone, but no free taygen, that gu being
completely conyerted into ths prodncta joat mentioned in paaaing throogh the outer
cone. The composition of the gusee at different heights of the flame is determined
bj the nataiBl action of the combnatible gawe in the inner gone and the oxidiiad
prodncta [meeeding from the outer part.

The laminoiui envelope annonnding the innv cone Tariee In composition from irith-
out inwardi, the onter portion containing a eoneiderable quantity of free oxygen
which gradually diminiehee as it penetrates inmrds. The thickneoa of the Inminons
eoTelope iDcreaces towards the upper part of the fleme, because this portion contaioi
the oxidised prodacte ascending from below, in addition to those direclly formed
there, so that the proportion of combustible giaes in the upper part of the flame is less,
the combustion is slower, and the oxygen of the air can penebvte to a greater depth;
hence the lumicons enTslope diminishes in brightness and incceoaea in thickness from

_^ ,__! -earthe apex it Drr--'- "^ - ' ' - "' """

reducing part of the fli
envelope.

The Semes of combnstible bodies which do not onde^ the decompositions above
deecribed, differ considerably in composition from those of wax or tallow. The iominooa
cone is often abeent, more rarely the mantle ; the inner com
sent, and the hloe zone is almost always T(ipresent«d by
the part where the still undiluted combustible gas cornea
in contact, at a comparatively low temperature, with eit
containing its fall amount of oxygen. The flame of car-
bonic oxide exhibits a distinct dork cone (consisting of
unbumt gas}, a dark blue zone, and a yellowish'red mantle
not sharply de&ned from the surrounding air. The flame
of sulphur has a blue lone at the bottom and a Tiolet-
reddish mantle, the colour wil^ which sutphur-Tapoar
burns when previously atcongly heated. In the alcohol-
flame {jig. ISO) the inner cone a is very large, in conse-
quence of the volatility of the combostible substance : the
lominoos cone b is small, because there is but little carbon
separated; and the mantle d n>peaiB veir much derdoped,
because the eye is not daslsd by a bright lominous cons.

The composition of the flame oteoat-gat has been ex-
amined by Landolt (Fogg. Ann. xcii. 389), by a method
sinilar to that above described for the wax and tallow
flames. The gas, properly purifled from carbonic add,
oxygen, and aqueous Tspoor, waa passed, under pressure ^
of a column of water, 17 Paris lines high, into a brass box,
having at the t«p a circular aperture Tnun. wide, and a tube of nearly the same diameter
passing tightly tbrongb the bottom, and tenninatitig on a levu with the circular
opening, so that the gas was made to isene through the narrow ring-shaped slit tbua
formed. A tube connected with on aspifator passed up through the brass tnbe into
the flame, as in Hilgard's experiments. The fiame waa protected from draoghts of
air I7 a gloss cylinder suspended over it and reaching to within ZOmm. of the bamer;
it was from E)S to 100mm. high when burning freely, and troia S6 to 9Smm. while gaa
was being drawn out of it The following table gives the eomposition of die pmiifled
coal-gas (L) introdnced into the burner, and that of the flame-gas, at Tariotu height*,
Q mm., above the ring-shaped aperture, in percentages by volome (E).

Compotitiim of CrKii-gat fiant.

D . . .

^^.

■-•

««..

«-..

u^ 1

■•

KS=, :

as!:?"!

£',S". :

tIltrof«> . .

3»-30

7(8

*js

Ifl

0-1 s

o-n

l-OO
»1B

0-90

1 -SJ

s~4a

X7,

O-fiO

1098

COMBUSTION.

From theie Kfolta, Landolt has calculated the uroportioDS of coal-gas and aarwfaiA
by their matval action form the several parts of the flame-gas. The results are som^
what diaeordant, according as the carbon, hydrogen, or nitrogen Is taken as the basil
of the ealeolation ; but the most probable reralts are giren in tiie foUoving tables in
which A denotes the Tolnmes of atmospheric air which have mixed with 100 toIsl ooat>
gas to produce the flame-gas at the several heights, D, indicated in the firrt lines,
100 •»• A » M Tolumes of this nnbomt gaseous mixture yield, after eombnstion, V
Toluraes of flame-gas. The composition of the M Tolumes of unbumt gaseous mixture
•ad of the V volumes of flame-gas produced by their combustion are given in the lower
part of the table.

Con^M)siiion of Ooal-gtu Jlame,

D . . •

Oram.

10mm.

90mm.

aOnm. I

«-^

«—

A • • *

S7m

4ft-48

178-76

887-73

336-30

aai-«6

N • • .

1S7*08

146-43

878-76

3/7-73

436-30

481-66

V . . .

111-41

180-09

845-96

311^

428-69

461-13

14-60

▼

Hydrogen .

S930:

18-66

41-04

14-95

44-00

ft-49

44-00

1.V54

41-37

11-96

Murah-ns .
Carbonic oxide .

iO-JW

aa-T?

40-71

80>20

38*40

38-34

38-40

81-65

38-80

11-92

38-30

364

4-9^

7-a4

764

14-07

6-73

14-06

6-73

14-68

6-56

88 84

6-56

15-14

RMiTlene .

404

4-81

A- 10

431

4-13

4-S8

4-13

483

5-<0

380

6-(10

877

Telrylene .

3*1A

S-06

8-lh

3^18

3-14

3*89

3-14

3-11

4-34

a-85

4-34

S-6A

Oxfffen .

ft*«7

0*66

9'W

0-78

36-81

0-47

47-73

...

70 88

79-99

Nitrogen .

29-41

89-41

38 66

14078

HO-78

184-23

184-83

270-48

870-45

307-10

307*10

("^rbonie add .

1-94

8-34

0-37

10-11

0-37

14-98

83 76

31-34

Water

—"

8-14

u-eo

36-86

58-66

—

7«JS7

76r61

187-08

111*41

14A-43

l-*1>-0-

878-76

-246-96

387-73

311-37

435-10

481-ae

481 as

46I-r

The sudden increase in the quantity of air mixiuff with the combustibie gas between
the heights of 10 and 20inm., is attributed by Landolt to the efibct of the ^ms cylinder.
The proportion of carbonic acid does not increase towards the upper part of the flame
so rapidly as might be expected, probably on account of the reduction of that gis to
carbonic oxide by the the ignited carbon in the flame ; hence also the sudden increase in
the proportion or carbonic oxide between the heights of 30 and 40mm. The quantities of
the several combustible gases in the flame diminish from below upwards, at ratea propor-
tional to their combostibility. From 0 to 20mm. the decrease of the hydzoeen is the most
rapid ; the increase in the proportion of this gas in the flame above the height of 20min.
is probably due to the reducing action of the ignited carbon in the aqueoua vapour.
The marsh-gas diminishes more slowlv, and the heavy hydrocarbons still more slowly,
the latter indeed remaining nearly unaltered in the flame up to 40mm., and burning only
in the higher part.

The hnghteat liffkt was found to be given out by the part of the flame a little above
the top of the dark cone. In a gas-flame 100mm. high, in which the dark cone reached
to about 65mm., the highest part was at 70mm., and supposing the brightness of this
part « 100, that of the other parts of the flame was found to be as follows :

mm. mm. mm. mm* mm*
Height above burner . . 80 70 60 60 40

Brightness at the edge . . 66 100 77 47 20

Brightness in the middle * 66 100 50 24 6 —

The MM of a JUtme is greater in proportion as a larger quantity of oxygen is re-
quired to consume a g^ven volume of the rising combustible gac^ and also as the sor-
tounding oxygen is mixed or combined to a greater extent wiUi foreign gases ; for, in
that case, the combustible gas must present a larger circumference, and a greater number
of points of contact to the oxygen, m order that the hitter may be consumed as £ut aa
it IS supplied.

When different oombostible gases ai^ made to flow from a jet» in streams of given
strength, into oxygen gas and mixtures containing it» the following effects are observed :
Hydrogen gas gives a much smaller flame than <Sefiant gas (1 volume of hydrogen re-
quires half a volume of oxygen, and 1 volume of olefiant gas requires 3 volumes of oxygm
to bum it). Hydrogen gas mixed with nitrogen piives a still smaller flame than pure
hydrogen. The flame of hydrogen gas in oxygen is smaller than that of the same gas
in air; but there is this anomaly observed, that hydrogen gives a smaller flame in air

COMBUSTION, 1099

than it does in chlorine or nitrons oxide gas, — although one Tolnme of hydrogen na
requires 2*4 volnmes of air and only 1 Tolnme of chlorine or of nitrons oxide gas. This
pecoliarity is probably due to the different degrees of diflfusibilily of the gases through
each other.

The colour of the flame depends partly on its temperature, partly on the nature of
the substances contained in it.

Cold carbonic oxide gas gires a blue flame in bumine ; but if it has preriously been
heated, it gives a yellowish red flame. H^dropen and other gases, wnich in burning
evolve more heat than is evolved by carbonic oxide, exhibit a yellowish red flame even
when set on flre in the cold. But when hvdrogen gas issues from a flne jet (as in
Marsh's apparatus) against a porcelain slab held close in front of it, a pale green flame
is produced, — possibly in consequence of the cooling action of the porcelain. The blue
flame at the lower part of the flame of a candle likewise indicates a comparatively low
temperature. It is remarkable that in the glowing combustion of solid booies the colours
exhibit exactly the opposite relation (p. 88).

The addition of boric acid, or of a metallic chloride and oil of vitriol, to alcohol,
eives the flame a ^en colour — or, when it is more strongly heated, it turns yellow.
Chloride of strontium or chloride of caldum colours the flame of alcohol red ; cnloride
of barium, or common salt, colours it yellow ; protochloride of copper gives it a bright
red colour, with green and blue edges. Copper covered with oxide or sulphide (but
not clean copper^ held in the flame of alcohol, colours it green. The flames of other
burning bodies undergo similar alterations. Chloride of strontium reddens the flame
of hydrogen, marsh-gas, and oleflant gas, as also that of a candle — but only so long as
the salt itself remains moist ; on the flame of sulphur it has no effect In all these cases,
a portion of the added substance undoubtedly vmatilises : but whether it volatilises un-
decomposed, so that the colour of the flame is altered merely by the presence of boracic
acid, diloride of strontium, chloride of copper, &c., or whether decomposition takes
place, so that boron, strontium, calcium, barium, or copper is introduced into the flame
m the roduced state, is thero burnt, and thereby produces a different colour — is a ques-
tion not yet decided. Davy suggest'Cd the latter explanation.

Bespecting the prismatic spectra produced by flames in which Tarious salts, Sec are
igniteo, see Analysis (i 214), also Lioht.

In ordinary flames, the combustible gas occupies the int«rior^ and is surrounded by
atmospheric air or oxygen gas. But the combustion may likewise be sustained by
directing a stream of oxygen gas, air, &c, into a vessel filled with the combustible gas.
The interior dark part of the flame then consists of oxygen gas ; and this gas seems,
as it were, to bum in the combustible gas. In this manner, oxygen gas (and also
chlorine) may be made to bum in hydrogen ; likewise oxygen gas, common air, vapour of

Semitric oxide (or chlorine ma, with large deposition of sootj in defiant gas. To pro-
uce this effect, a stoppered bell-jar standing over water is filled with olefiant gas,
the stopper removed, the gas set on fire, and the oxygen tube, which is fitted into
a cork, plunged into the olefiant gas, the cork serving to dose the aperture. Or a
quantity of chlorate of potassium, contained in a small basin suspended from the cork,
may be heated till it evolves oxygen gas, and then plunged into the olefiant gas pre-
viously set on firo at the mouth of the jar : the combustion then goes on, producing a
beautiful light, the colour of which may be variously modified bv the addition of nitrate
of sodium, strontium, or copper (Kemp, J. Pharm. xx. 413; also J. pr. Chem. iiL 44).
The fiame of oxygen in hydrogen gas is green, even when both gases are quite pure :
that of oxygen in marsh-gas is yellow. The first-mentioned flame is much larger than
the other, l^cause a measure of oxygen gas requires two measures of hydrogen, and only
half a measure of marsh-gas (Hess, Fogg. Ann. xliv. 336 ; also J. pr. Chem. xiii. 516^.
The flame is smaller when oxygen or nitrous oxide gas, or vapour of pemitno
oxide, or chlorine gas is made to pass into hydrogen gas, than in the contnu-y case ;
according to what was said on page 92, the contrary might have been expected. A
much smaller flame is produced when oxygen passes into oleflant eas than when it passes
into hydrogen. With olefiant gas, the fiame is dark within ; uien follows a brilliant
envelope, hot enough to melt platinum ; then, towards the outside, a dark yellow flame,
lengthening above and containing soot, the greater part of which remains unbumt
When oxygen gas is blown into boiling sulphur, a yellow flame is produced, dark within,
red on the outside and at the apex : air gives a smaller flame than oxygen, dark within,
blue without, and red at the apex (Waldi e, Phil. Mag. [S] xiii. 86).

The Blow-pi^ flame is of the same character as those just mentioned, inasmuch aa
the air is blown into the middle of the ascending combustible vapour. The strongest
heat exists at that part of the flame where the dark cone of injected air terminates in
a bluish vertex, and the burning envelope which surrounds it concentrates itself upon
a single point (i. 611).

1100 COMBUSTION.

UL Causes which modify and exHngvish OomlnuUon,

When the bIow or rapid combinatioii of a body -with oxygen has once been set up by
elevation of temperature, the continuance of this combination, after the supply of heat
from without has been withdrawn, depends in general on the following oonditioa : —
Whether the quantity of heat, which the body in combining with oxygen evolves in a
given time, is equal to that which, in the same time, is carried away by snnonnding
bodies ; and consequently, whether the bodv remains at the temperature neeeasaiy far
combustion; — and in particular: 1. On the difference between the temperature at
which the body will combine with oxygen, rapidly or slowly, and the external tem-
perature ; 2. On the quantity of heat which it evolves in burning ; 3. On the rare&ctioii
or condensation of the oxygen gas ; 4. On the greater or smaller admixture of foreign
gaseous bodies not contributing towards the oombustion ; 6, On the presence of liqiud
or solid h^t-conducting bodies.

1. Iron and diamona require a white heat to make them bum rapidly: hence, when
they are heated in the air till they be^ to bum, the combustion ceases as soon as the
access of heat from without is discontmued, whereas sulphur, and other easily inflam-
mable bodies, continue to bum.

2. Carbonic oxide gas, which is as easily inflammable as hydrogen, does not exhibit
rapid combustion after it has been rarefied to about one-fouith of its ordinaiy density,
because it evolves less heat during combustion. (H. Davy.)

S. A certain degree of rarefaction prevents the continuance of combustion ; because
combination, and therefore, also, development of heat, is retarded by it. Detonating
gas (a mixture of two measures of hydrogen gas and one of oxygen), when rarefied
to -fk of its ordinaiy density, no longer explodes by the electric spaik (H. Davy).
Hydrogen gas, mixed with air in the right proportion, will not take fir« under an
external pressure of five inches (Orotthuss). Hydrogen gas issuing from a jet into
the air exhibits rapid combustion under a fomrfold rarefaction of the air, burning even
with a larger flame than before, but is extinguished when the density is reduced to
between ^ and } of its ordinary amount.

The burning vapour of alcohol, ether, or wax, is extinguished, under these cirenm-
stances, by a five or sixfold rarefcu^tion; sulphuretted hydrogen by a sevenfold rare-
faction of the air. Sulphur continues to exhibit rapid oombuiStion, even when the air
is rarefied fifteen times; phosphorus, When the density is reduocid to ^; while the
easily inflammable variety of phosphoretted hvdrogen gas produces a flftghing light,
even in the best vacuum that can be made witn the air-pump. Vapour of ether, in
air rarefied thirty times, still produces a feeble fiame on the introduction of a red-hot
iron. Slow oombustion on the surface of platinum is exhibited by marsh-gas, down
to a fourfold rare&ction of the air ; by carbonic oxide, to sixfold ; by vapour of alocdiol,
ether, or wax, to eightfold; by olefiant gas, to ten or elevenfold; by hydrogen gas, to
thirteenfold ; and by vapour of sulphur, down to twentyfold rarefaction of the air.
By elevation of temperature, the limits of inflanmiabiUty are still fizrther extended;
so that detonating gas rarefied eighteen times, and heated to redness, exhiHts a light
as if from combustion, on the passage of an electric s^k. (H. Davy.)

Within certain limits, however, the rate of combustion is independent of the density
of the surrounding atmosphere. Frank land found that a steann candle burned away
at the same rate on the summit of Mont Blanc and in the valley of Ghamounix. The
brightness of the fiame is, however, greatly diminished by rarefaction of the air. A coal-
gas flame, burning in artificially rarefied atmospheres, exhibited an average decrease
of illuminating power amounting to about 5*1 per cent for each diminution of 1 inch
of mercurial pressure. (Proc. Koy. Soc xL 137.) See Flajcb.

4. Foreign gaseous bodies, which contribute nothing to combustion, absorb a portion
of the heat genejrated by the combination, and re£ice the temperature below the
burning pointy the rapidity of their action being proportional to their quantity, mobi-
lity, and capacitv for heat. Not onl^ do bodies m general bum more rapidly in
oxygen gas than m atmospheric air, which contains only one volume of oxygen to four
of nitrogen ; but iron and diamond, which, when once set on fire, continue to bum in
oxygen gas, are immediately extinguished in atmospheric air. In air four or five
timea compressed — which, therefore, contains one volume of oxygen gas — candles,
hydrogen gas, sulphur, charcoal, and iron, do not, in consequence of the abetraction of
heat by the nitrogen, bum more rapidly than they would in uncompressed air, to
which f of a volume of oxygen had been added. One volume of detonating gas loses
its power of taking fire by the electric spark, if there be added to it | a volume of
olefiant ea^ i^^^ volume of fluoride of silicium, 1 volume of marsh-gas, 2 volumes of
sulphydnc or hydrochloric acid gas, 8 volumes of hydrogen in excess, 9 volumes of
oxygen in excess, or 11 volumes of carbonic oxide: 5 measures of aqueous vapour do
not destroy the inflammability of 1 measure of detonating gas (H. D a vy ). According to

COMBUSTION. 1101

Humboldt and Q-ay-Lnssae (Gilb. Ann. xz. 49), theinflammabilitj of one Tolome of
detonating gas is destroyed by the admixture of 5 Tolumes of oxygen, or 4*7 volumes
of hydrogen eas. Marsn-gas is no longer inflammable by the electric spark, when it
is mixed wiui 11 measures of oxygen instead of the 2 measures whicn it actually
requires to combine with it (H. Davy). Goal ^rb bums continuously in a mixture
of 1 measure of oxygen and 7 of nitrogen, but is extinguished when the quantity of
the latter amounts to 8 measures ; it bums in a mixture of 1 measure of oxygen with
8, but not with 4 measures of hydrochloric acid gas ; with 2}, but not with 3 measures
of carbonic acid : with 2, but not with 2} measures of fluoride of silicium. The greater
the density of the inactiye gas, the smaller is the quantity which suffices to stop the
combustion ; because the combustible gas difiuses itself more readily through a heayy
than through a li^ht eas, and therefore cools down the fiister (Waldie). A lighted
candle is extinguished in air to which | of its rolume of hydrochloric add gas, or X of
fluoride of silicium, has been added. When combustible bodies bum in a confined
space, the relative quantity of nitrogen, &c. becomes increased, partly by consumption
of oxygen, partly by formation of gaseous products of combustion, such as carbonic
acid, sulphurous add, &c ; and thus the combustion is brought to an end. In one and
the same limited space, a candle goes out first, then hydrogen gas, then sulphur; while
the slow combustion of phosphorus will go on as long as the smallest quantity of
oxygen remains. (H. Davy.)

6. Solid burning bodies are extinguished when laid on good-conducting supports,
e. g. glowing coals on considerable masses of metaL — A mixture of a combustible gas
and oxygen will not take fire in yery narrow tubes, because their sides cool down too
quickly: this is the prindple of the oxy-hydrogen blow-pipe (i. 616). From the
same cause, the flame of a mixture of combustible gases and common air is often
unable to pass through the meshes of wire-gauze : the passage of the flame takes place,
however, with greater facility, the lower the temperature at which the gas takes fire,
the greater the heat evolved by its combustion, the more quickly it is foreed through
the apertures by pressure or draught, the wider the meshes, the smaller the mass and
specific heat of the metal of which the gauze is made, and the higher its tem'perature.
Above a certain temperature, all flames pass through it. The flame of a cotton thread
may be extinguished by holding over it, even at some distance, a ring of fine iron wire,
or a thicker ring of glass (Davy). On this impenetrability of wire-gauze by the
flame •of light carburetted hydrogen gas in coal-mines, is based the Safety-lamp of
Sir H. Davy, which consists essentially of a common oil-lamp having its flame sur-
rounded by a cylinder of wire-gauze. Wlien this lamp is taken to a part of the mine con-
taining an explosive mixture of ^as and air, the interior of the cylinder becomes fllled
with a blue fliune ; but this flame is not communicated to the enlodve mixture outside,
because it is cooled down below the burning temperature in its passage through the
meshes of the gauze. (See the artide Batbtt Laicp, in Ur^s Diciionary of Arts,
Manufactures, and Mines, ilL 612; also BonaltTs and Richardson* s Chemical Technology,
i [2] 611.)

The same prindple is appHed in many elegant contrivances now in use in diemical
laboratories for bunung a mixture of ^SB and air, so as to produce a hot smokdess
flame (p. 89), the mixture of gas and air being made to pass through a sheet of wire
gauze, and set on flre at the other side, so that the flame cannot extend to the oriflce
whence the gas iasues.

Motion of the air, produced by draught or by the bellows, acederates combustion
and increases the intensity of the heat, by continually bringing fresh portions of air
in contact with the burning body. Very rapid motion of the air may however extin-
guish combustion, dther hj the cooling — if the quantity of air supplied in a given
time is such that the burning body cannot in the same time consume the whole of
its oxyeen ; or by blowing the burning vapour away from its source, so that the flame
can no longer communicate with the fresh mafler which issues.

Fire-extinguishing substances act either by cooling, as water does, — or by covering
the burning body and thereby impeding the access of air — as when a rug or other not
easily combustible body is thrown on a mass of light burning materials, or when a flre
is choked with earth or ashes ; — or lastly by surroundinff the burning mass with an
atmosphere not containing oxygen. This is the prindple of Phillips*s ^e-annihUator,
in which a mixture of 20 pte. charcoal, 60 pts. saltpetre, and 5 pts. gypsum, is
set on fire by means of chlorate of potash, sugar, and sulphuric add, the heat pro-
duced by the combustion being made at the same time to convert into vapour a
ouantity of water contained in the apparatus. The result is the instantaneous pro-
auction of a large quantity of steam, carbonic add and. other inactive gases, which can
be at once dir^ted on the burning mass. (See Uris Dictionary of Arts, Manu-
factures, and Mines, ii. 212.)

With regard to the effidency of steam in extinguishing fires, Mr. Ghraham observes

1102 COMENAMETBANE — COMENAMIC ACID.

in his "Report on the fire in the Amazon/* already quoted (p. 88), that ** stesra can
only be said to be efficient in extinguishing flame, or a blaee from light objects, and
ia not to be relied on beyond an early stage of a fire. Upon a maas of red-hot cinders^
the extinguiahing effect of steam is insensible." The same is probably trae iritb re-
gard to carbonic acid, nitrogen, and other gases.

Method of diminishing the infiammability of light fahric$, — Much attention has
lately been devoted to the problem of rendering muslin and other light fabrios non-in-
flammable, with the Tiew of preventing the terrible accidents, which so frequently arise
from ladies' dresses coming in contact with the flame of a candle or the fire in a
grate. This object is attained by steeping the fabric in a saline solution, and then
drying it in the ordinary way. The fibre is thereby surrounded with a crost of in-
combustible matter, which prevents it from taking fire by momentaiy contact with a
burning body, and causes it, even if held in a flame, to bum with a alow amouldoing
combustion, without bursting into flame.

Almost any salt will produce this effect, but the greater number are unfit for appli-
cation to articles of dress, because they injure the texture, rendering tbe fabric hanh,
and destroying all its beauty. The scdt which is found to answer most completely all
the required conditions, is the neutral tungstaU of sodiunu Mualin steeped in a
solution containing 20 per cent of this salt is perfectly non-inflammable when diy,
and the saline film left on its surfiu^ is smooth and of a fiitty appearance like tale,
and therefore does not interfere with the process of ironing, but allows the hot iron to
pass smoothly over the surface. The non-fulfilment of this latter condition com-
pletely prevents the use of many other salts — such as sulphate and phosphate of
ammonium, which are otherwise efficacious in destroying inflammability — for all
fabrics which have to be washed and ironed.

The use of the tungstate of sodium for this purpose offers but one difficulty, viz. the
formation of an acid tungstate of little solubility. This inconvenience may, however,
be obviated by the addition of a small quantity of phosphoric acid or phosphate of
sodium. The best way of preparing a solution of minimum strength for the purpose,
is to dilute a concentrated solution of the neutral tungstate with water to 28^ Twaddell,
and then add 8 per cent, of phosphate of sodium. The solution is found to keep, and
to answer its purpose well; it is now constantly used in Her Majesty's laundry
(Versmann and Oppenheim, Communication read before the Britieh Association
at Aberdeen, 15th Sept. 1859 ; Pharm. J. Trans. [2] i. 385). The use of phoephate of
ammonium for preserving light fabrics from ignition was proposed, many years ago» by
Quy-Lussac.

COMBVAMBTBAWB. Syn. with Comenamjlte of Ethtl.

COMBWAAKZC ACZB, C?'H*N0* + 2H«0 =^-^'-^^^*^g'^''|o + 2H»0. (How,

Ed. Phil. Trans, xx. [2] 225 ; Ann. Ch. Pharm. Ixxx. 65.)— This acid is produced hj
the dehydration of acidcomenate of ammonium, C«H«(NH*)0»-H«0-CTB[*NO*. IX
may be prepared by heating the salt to 199^ C. in a sealed tube, and precipitating
the aqueous extract with hydrochloric acid ; or better, by boiling aqueous comeoie
acid with excess of ammonia till nearly all the ammonia is expelled, collecting on a
filter the grey argillaceous sediment of comenamate of ammonium and colouring matter,
and dissolving it in hot water ; decomposing the solution with hydrochloric acid not in
excess ; and purifying the precipitated dark brown scales of impure comenamic add
by repeated crystallisation from hot water, and treatment with animal charcoal free
firom iron. The crystals contain 2 atoms water (18*81 per cent), and give it ofiT at
100*^ C. They dissolve sparingly in cold, more freely in hot water, forming a solution
which reddens litmus strongly. The acid dissolves in boiling alcohol of ordinaiy
strength, but is nearly insoluble in boiliyg absolute alcohol.

The acid is decomposed by boUing with potash, yielding ammonia and eomenate of
potassium. It dissolves readily in hydrochloric actd and other strong mineral acids,
and is precipitated therefrom by ammonia in quantity rather less than sufficient for
saturation, as comenamate of ammonium.

Comenamic acid is monobasic, the normal salts being C*(H*M)NO^ There are also
several basic salts. The ammonium-salt, C'H'(NH^)NO^ forms small grains made up
of delicate needles nearly insoluble in cold water ; their solution reddens litmus. The
potassium' and sodiumrsalts crystallise readily and redden litmus. The normal barium-
salt, CH^aNO*, obtained by mixing a solution of thecrystaUised ammonium-salt with
chloride of barium, forms crystals with 1 at water, which redden litmus. A basie
barium-salt, C"H*BaNO'.BaHO + |H^0, is formed, by mixing chloride of banum
with an ammoniacal solution of comenamate of ammonium, as a white heavy pre-
cipitate, which gives off its water (2*83 per cent) at 100° C. The aqueous add left in

COMENIC ACID. 1103

oontaet with carbonate of barium fonnfl the nonnal or the baaie salt according to the
relatiye quantities. With /tme, it forms two salts of similar constitution.

The ammoniom-ealt forms, with acetate of Uad, a heavy insoluble precipitate.

Comenamie acid imparts to ferric salts a deep purple colouring, which is destroyed
by mineral acids, but reproduced by water.

The crystallised ammonium-salt forms a grey precipitate with sulphate of copper.

The ammonium-salt super-saturated with ammonia forms, with nitrate of eitver, a
yellowish flocculent, quickly blackening precipitate ; and the crystallised ammonium-
salt forma a white gelatinous preeipitatei which is partially deoomposed by boiling
water.

Comenamaie of Ethyl, Comenamio ether, Commamethane, C*H*NO* •■
C*H*(C*H*)NO*. (How. Ed. M. PhiL J. L 212.>--When a solution of comenamie add in
absolute alcohol is treated with dry hydrochloric acid gas, and the liquid subsequently
evaporated, there remains an oil which dries up at 100*° C. to a solid mass, and when
dissolved in alcohol, yields a hydrochloraU of comenamie ether, C»H"N0*.HC1 + H«0 ;
and on treating this compound with oxide of silver, or with ammonia (not in excess),
comenamie ether is obtained in needle-shaped crystals containing 1 at wat«r, which
they give off at 100^ C, leaving the anhydrous ether. — When the solid mass above men-
tioned is treated with water, comenamie acid remains undissolved, and another portion
of that acid separates as a crystalline powder from the solution, which contains hydro-
chloric acid.

The ether is neutral ; melts to a yellow liquid when heated ; is not altered hj
ammonia in the cold; and is converted by nitric acid into oxalate of ammonia. It
dissolves sparingly in cold water, readily in hot water and in mineral acids, sparingly
in absolute alcohol.

A compound of this ether with hydriodic acid is obtained by heating iodide of
ethyl with a solution of comenamie acid in absolute alcohol to 160^ C, in sealed tubes.

OOmVXC AOZB. C«H*0»-» ^^^^^*^/\0\ or C'*E*0** - Q*E*C^.2H0. Pa-

rameconic add. Anhydrous Meconic aeid.^(R ohi quel, Ann. Ch. Phys. [2] 11 326;
liii. 428. Liebig, Ann. Ch. Pharm. viL 237 ; xxvi. 116. Stenhouse, I^hil. Mag.
[3] xzv. 196. H. How, £d. PhU. Trans, xx. [2] 225. Om. xi. 328. Gerh. il 182.)
Comenic acid was discovered in 1832, by Bobiquet, who at first regarded it as anhy-
drous meconic acid ; it was afterwards recognised as a distinct acid by Liebig, who first
observed the formation of carbonic acid which accompanies the conversion of meconic
into comenic add. It is produced: 1. By heating meconic acid to temperatures
between 120*^ and 220^^ C, the change being attended with evolution of carbonic anhy-
dride:

C*H*0» - C«H*0» + C0«.

2. By continued boiling of meconic add dissolved in water or in hydrochloric add,
likewise with evolution of carbonic add. (Bobiquet.)

Preparation. — Meconic acid or its potassium or barium-salt, is boiled with a strong
mineral add; or meconate of calcium is boiled with highly concentrated hydrochloric
acid (Stenhouse) ; or add meconate of potassium, produced by treating crude neutral
meconate of calcium with very dilute hydrochloric acid, is heated with as much strong
hydrochloric add as is required to dissolve it (How), and the solution is left to crystal-
lise. When the mere aqueous solution of the acid is boiled, too large a quantity of
brown secondary product is formed. (Bobiquet, L iebig.)

To purify the product, the still reddish avstals are dissolved in a slight excess of hot
concentrated potash ; the solution is filterea hot to separate a small quantity of lime ;
the white nodules which form on cooling are washed with a small quantity of cold
water, till the strongly coloured mother-liquor is removed, then boUed with excess of
hydrochloric add; and the comenic add which separates on cooling is freed from
hydrochloric acid by two or three recrystallisations from water. The still remaining
tinge of red may be removed by treatment with animal charcoal (Stenhouse). Or,
the impure add is dissolved in a quantity of boiling ammonia just sufficient to dis-
solve it (an excess, as well as continued boiling, causes the liquid to turn brown), and
^tered immediately at the boiling heat ; the yellow crystals which separate from the
dark filtrate when left at rest, are washed with cold water and recrystallised horn
hot water ; their pale-yellow aqueons solution is mixed with strong hy<uochloric add ;
and the comenic acid, which is predpitated in the form of a white or pale ydlow powder,
is crystallised fi^m boiling water.

Properties. — Comenic add forms anhydrous prisms, laminae, or granules, havins a
very faint yellowish colour, reouiring more than 16 pts. of boilina water to dissolve
them ; sparingly soluble in hydrated alcohol, but insoluble in absolute alcohoL

Decompositions. — 1. The add, when subjected to dry distillation, behaves like
meconic add (Bobiquet). When comenic (or meconic) add is quickly heated in a

1104 COMENIC ACID.

retort, aboTe the temperature of 200^ to 22Q9 C, at idiich pyiomeeonic acid would be -
formed, bat not till complete carbonisation takes place, an add yeUowish watery
Uqnid passes oyer, haying a &int empyreomatic odour ; and there remains a blacki^
grey, poroos, carbonaoeons mass, from whose ammoniacal solution, after filtration,
hydrochloric acid throws down thick dark green flakes, which, if exposed to the air
after washing with water, shrink up to a sabstance resembling glanee^coal in appearance,
and in its chemical relations agreeing perfectly with metagallic acid (Winckler,
Repert, 69, 42). — 2. Comenic acid suspended in water through which a stream of
chlorine gas is passed, ibrms a solution of chlorocomenic add, which crystallises out
after a while, and oxalic add, which remains in solution :

(>HK)» + a« - C*HK)10» + HCL

The oxalic acid and a brown colouring matter which forms during eyaporation must
be regarded as secondary products (How). — 3. Similarly, the co&urless solution of
comenic add in bromine-ioater yields bromocomenic add which oystallises, and oxalic
add (How). — 4. Nitric acid^ eyen when yery dilute, conyerta comenic add into
carbonic, hydrocyanic, and oxalic acids ; and if the nitric add is tolerably strong, and
heated at the beginning of the action, the process is complete in a few minutes
(How^. — 5. Strong sulphuric acid acts upon comenic add in the same manner as on
mecomc add. (B o b i q u e t). — 6. The add dissolyed in water and boiled with excess of
ammonia till nearly all the ammonia eyaporates, forms a black-red liquid, which, on cool-
ing, deposits impure comenamate of ammonium as a grey yisdd sediment. (H o w, p. 96.)

GouBNATB s. — Comenic add is dibasic, forming neutral or normal salts, <>H'M*0*,
and acid salts, C'H'MO^. The nsutrail comenatos of the alkali-metals cannot be
obtained in the solid state.

Acid Comenate of Ammonium, CH'(NH*)0*, is obtained in How's process for
purifying comenic add. The aqueous acid slightly supersaturated with ammonia,
and eyaporated in yacuo oyer oil of vitriol, yields four-sided prisms haying a yellowish
tinge ; they giye off 9*04 per cent (1 at) water at 100^ C. (Stenhouse). The salt
forms white square prisms haying a yery strong lustre ; they redden litmus eyen when
they separate on cooling from a hot solution of the add in excess of ammonia. They
do not giye off anything at 177° C, but at 199°, in a sealed tube, they melt and are
conyertod into a black mixture of charcoal and comenamate of ammonium ; their
aqueous solution is also conyerted into this salt by continued boiling with ammonia
(p. 94). They dissolye readily in boiling water, sparingly in alcohol. (How.)

Comenatea of Barium, o. Neutral. C«H«Ba*0» + HH) (at 121o C.).— Chloride
of barium mixed with a solution of the add in excess of ammonia throws down imme-
diately— or in yer^ dilate solutions, after some time only — ^yellowish quadratic needles
united in concentric groups. These crystals do not lose water at 100° C, but at 121°,
they giye off 19*03 per cent water, and if then heated to redness in the air, bum
away in a fiery doud. They do not dissolve in boiling water, but when boiled with
it are converted into a basic salt, which does not give off water at 121° C, and con-
tains 54*6 per cent baryta. (How.)

fi. Acid salt C'H'CaO* (at 100° C.).— The free add does not predpitate barium-
salts (Stenhouse). The salt is produced when baryta is boiled with excess of the
add. Chloride of barium mixed with a cold-satarated aqueous solution of the crys-
tallised ammonium-salt immediately forms a crystalline predpitate, and with a more
dilute solution, gradually depodts transparent crystalB, whidi give off their 20*86
per cent (somewhat more than 3 at) water at 100° C, and melt at a stronger heat
(How.)

Comenate of Calcium, a. Neutral. C«H*Ca«0» + HK) (at 121°C.)— The add
Bupersatorated with ammonia, predpitates from chloride of caldum, if the solutions
are saturated, veiy short prisms which give off 18*20 per cent (f at.) water at 121^ C,
and when the solutions are dilute, smau shining crystals, which at 121^ give off 31*37
per cent. (6^ at) water. The two kinds of crystals are insoluble in water, but become
basic when boiled with water.

fi. Acid salt. C«HK:^0* (at 121° C.)— A mixture of chloride of caldum and a cold
saturated aqueous solution of the oystalline ammonia-salt, quickly deposits trans-
parent^ shining, rhombic crystals, which give off their water slowly at 100°, but the
whole, amounting to 26*15 per cent (| at) at 121°. They dissolve readily in boiling
water, and crystallise therefrom on cooling.

Comenate of Copper. C«H*Ca*0*+H«0 (at 100°C.)--The dark green aqueous
mixture of cupric sulphate and comenic add (or the crystallised ammonium-sait, ac-
cording to How) deposits, after a few minutes, elongated pyramids having the colour
of Schweinfurt green. No add comenate of copper i^pears to exist (How.)

Comenates of Iron. Ferric Comenate. Fe«0*.4C«H*0» + 8HK), or [if/« «
JFe] « /»«0.4C«HycO» + 6HK) (at 100° C.) — Comenic add imparts a brij^t red

COMENIC ACID. 1105

colour to ferric salts. The dark blood-red mixture of ferric sulphate with a cold-
saturated solution of oomenic acid or its ammoniacal salt, becomes paler by long
standing, and deposits small pitch-black, shining, veiy hard, nearly tasteless crystals,
which grate between the teeth, yield a dark brown powder, and £ssolye slowly both
in cold and in hot water, forming a pale red solution. (Stenhouse.)

The red mixture of aqueous comenic acid with ferric sulphate, becomes dazk yellow
at 66^ C. (and gives off carbonic acid, according to How), by conyersion of all the
sesquioxide of iron into protoxide at the expense of the acid, part of which at first
remains undecomposed, so that a fresh portion of ferric sulphate again produces
reddening. This colour, howerer, disappears when the liquid is digested for twelve
hours with excess of ferric sulphate, in consequence of the complete conversion of co-
menic acid into another acid; hence the no longer red liquid deposits small, pale
yellow, shining crystals of a ferrous salt (probably ferrous oxalate, as the liquid con-
tains oxalic acid, according to How), which bum away when heated, and dissolve
sparingly in water; the acid of these crystals extracted by potash no longer reddens
ferric salts. (Stenhouse.)

Comenate of Lead, — The acid and its ammonia-salt form with neutral acetate of
lead a yellowish white granular precipitate, soluble in excess of oomenic add, but not
in acetic acid. (Stenhouse.)

A lead-salt examined by Bobiquet contained 64*1 per cent, oxide of lead.

Comenates of Magnesium, a. Neutral, C'H'MffH)* + |H*0 (at lOOOC.)—
Sulphate of magnesium forms with the acid saturated wiui ammonia, especially when
the mixture is stirred, hard, closely adhering, o^stalline grains, consisting of short mi-
croscopic needles. These crystals heated to 100^, slowly give off 26*50 per cent.
i4 at.^ water ; and if then kept at 121° for four days, they give off such a quantity
nearly J at] that the residual salt contains 21*30 per cent, magnesia, and is there-
bre not quite anhydrous. They are not soluble in boiling water. (How.)

/S. The acid eglt, C*H*MgO« 4- H*0 (at 100° C), crystallises, after a while, £rom a
mirture of sulphate of magnesium with the cold-saturated solution of the crystalline
ammonia-salt, in small rhombs, and from more dilute solutions, on evaporation, in
larger crystals, which are strongly acid, give off 22*08 per cent. (3 at) water at 116°,
and dissolve readily in hot water. (How.)

Comenic acid does not precipitate Tnercwrio chloride. (Stenhouse.)

Comenate^ of Potaeaium. a. Neutral, O'H'K'O'. — The aqueous add half
neutralised with potash, so as to form the mono-potassic salt^ yields no predpitate, but
when completely neutralised, deposits the sparingly soluble dipotassic salt In this
respect^ comenic add is oppodte to meconic add, the add potasdum-salt of which is
the less soluble of the two. (Bobiquet)

/9. Aeid Malt G*H"EO*. — The add, dissolved in a slight excess of boiling potash-ley,
yields crystals on cooling, which, after washing; with cold water, crystallise from hot
water in short, square, anhydrous needles, which redden litmus. (How.)

Comenatea of Silver. — The neutral salt, C*H'Ag'0^ is obtained by exactly pre-
cipitating a sohition of nitrate of silver with oomenic add neutralised with ammonia.
Tne thick yellow precipitate does not detonate when heated. (Liebig.)

The acia salt, C'H'AgO*, is the predpitate (white, granular, or flocculent^ according
to Stenhouse) which the free add produces in solution of nitrate of silver. (Li ebig.)

Comenate of Sodium. — The solution of the add in tolerably strong boilinff soda-
ley yields, on cooling, nodules sud prisms, which, after washing with a little cold water,
crystallise fh)m the smallest possible quantity of hot water, in acid, anhydrous, four-
sided prisms, containing 17*09 per cent soda, and therefore -> OH'NaO*. (How.)

Comenatea of Strontium. — ^The neutral and add salts closely resemble the cor-
responding barium-salt^ but are more soluble.

Subaiitution'derivativea of Comenic Acid.

Bbox<)ooxbnio Aoid. CH'BrO'. (How, loc.oU.) — ^The colourless solution of
comenic add in a slight excess of bromine-water deposits, after a few hours, oily,
colourless, shining, strongly refracting, fouivsided prisms, which dissolve in water and
in alcohol less easily than chlorocomenic add ; they give off their water of crystallisa-
tion at lOO*" C.

The acid is decomposed by nitric acid, yielding hydrobromic, carbonic, hydrocyaoie,
and oxalic adds. With sine and water it decomposes like chlorocomenic add.

Bromocomenic is dibanc, like oomenic add. The acid bromoeomenatea of ammonium,
potaaaium, and aodium are orystallisable ; the first crystallises in long needles. The
neutral salts of these bases are not obtainable.

The neutral bromoeomenatea of barium and calcium are amorphous and insoluble;
the aeid salts are very easily soluble.

Vol. L 4 B

1106 COMENIC ACID.

The solution of the acid in a eUght excess of ammonia jielda, ^th nitztte of silrcr,
nentral IfnnnocotMnate of gUver in the form of a jellow precipitate haring the oon-
sifltence of day when dry ; and the solution of the acid in warm water fomu with
nitrate of silTer, flakes of the add saU, C'H'AgBrO*, which crystsliiies from boiliog
water in short shining prisms.

Chlosocombkio Acid. C*H*C10*. (How, he. 6i<.)— Obtained by passbg
chlorine through water in which pulverised comenic add is suspended, washing the
crystals which separate with cold water, and recrystallising from hot water, — (vby pui-
ing chlorine into cold water saturated with acid comenate of ammonium ; the liquid
then acquires the colour of chlorine-^water, and gradually deposits ayBtak of chloro*
comenic aeid, which increase on addition of hydrochloric acid, and may he purified
as in the first process. The mother-liquor becomes continudly browner, and stiH
deposits brown crystals of the acid.

The crystals are long, colourless, shining, four-sided prisms, containing 12*47 per
cent. (I at.) water, which they give off at 100^ C. They dissolve both in cold and
in hot water^ more readily than comenic acid ; very easily in warm alcohoL

The acid melts when heated, blackens, gives off a large quantity of hydiochloiie
acid, and at last yields a small crystalline sublimate, probably consisting of ptn-
comenic add. By niiric acid it is quickly converted into hydrochloric, carbonic; hj-
drocyanic, and oxiEtlie adds. Its aqueous solution, tzeated with zinc, slowly gives off
hydrogen, and afterwards contains hydrochloric acid and oxide of zinc.

Chlorocomenic add is dibasic, forming neutral salts, CHM*C10*, and add taltt^
C«H«MC10».

The chlorooomenaies resemble the oomenates, but dissolve more readily in water.

The add chlorooomenates of ammonium, potassium, and sodium erystallise readily.
The neutral salts are not obtainable.

The ammonium-salt forms with chloride of barium and chloride of eakivm, bnndlei

of needles which appear more or less quickly, according to the degree of ooneentratioD;

I with stdphate of TnaffTiesium, it gradually forms a few crystals ; and with ci^nic td-

i phatey immediately, a crystalline predpitate. The neutral chlorocomenates of these

bases appear to be all amorjdious and insoluble.

The add colours firric salts deep red, like comenic add.

Silver'salts. a. Neutral. — The add dissolved in a slight excess of ammonia forms,
with nitrate of silver, yellow amorphous flakes, which, after drying, resemble clay in
appearance, consistence, and tenacity. The salt dried at 100® G. contains 56*85 per
cent, silver, and is therefore CHAgH}10*. When ignited in the air, it leaves silrer,
together with a small quantity of chloride of silver ; when boiled wi^ hydrochloric
acid, it remains partlv undecomposed. It is insoluble in boiling water, but dissolTea
in nitric acid, from which, if heated with the salt, it separates cyanide of silver.

b. Acid. — The warm aqueous add added to solution of nitrate of silver throvi
down feathery crystals, which, after washing with cold water, separate from boiling
water in short shining needles. These crptals give off 4*44 per cent water at 100° C.
! When ignited, they leave silver and chloride of silver.

! Ethtlcokbnio acid. C*H»0» « C«H»(C*H»)0» (How, loe. dt.).— To raepars

this add, dry hydrochloric add gas is passed through absolute alcohol in which pnlreriiBed
comenic add is suspended, till the add dissolves, which takes place slowly ; the dear
liquid (which deposits nothing on addition of water) is CTaporated at a temperataro
below 100° 0. ; the crystalline residue is maintained at this temperature, till it no
longer smells of hydrochloric acid, and then left to crystallise by cooling from its sola-
tion in water at nearly 100°. Or, pulverised comenic add, heated with alcohol and
iodide of ethyl in a dosed vessel to a temperature above 100^, forms a granular deposit
consisting of an add not yet examineo, and ethylcomenic add, in needle-shaped
crystals, which may be separated and purified by reciystallisation. Similar products
are obtained by heating a mixture of comenic add, alcohol, and chloride of amyl to
160° for 12 hours.

The add forms large squaro needles, which begin to evaporate at 100^ C. ; melt at
135° into a dear brown-red liquid, which solidifles again in the crystalline form on
eooling ; and if kept for a longer time at 136°, sublime in long flat unaltered needles^
having the same compodtion. It is very soluble in water and alcohol, and reddens
litmus ; the aqueous solution coagulates albumin.

The acid may be boiled Ibr a short time without alteration, but if boiled fbr a longer
time, it yields firee comenic add. With aqueous solutions of the fixed alkalis, eren
in the cold, it very quicklv finms salts, and yields free alcohoL

When ammoniacal gas is passed through a solution of the add in absolute alcohol,
the ammonia salt is depodted in yellow silky bundles of needles, which give off am-
monia in drr air, and almost completely in vacuo over oil of vitriol, karing ethyl-
oomenic acid.

COMPTONITE — CONCRETIONS. 1 107

The acid imparts a deep red colour to ferric saits. Its silwrsalt is gelatinous^ and
decomposes Tery qxiicklj, even in the dark*

COaCFTOWZTa. See Thoxsonitb.

r. A process which has for its object to increase the amount
of a dissolved substance in a liquid, relatively to the quantity of the solvent, without
adding any more of the dissolved substance itself. 'When the solvent is volatile, this
object is effected by evaporation, as when water, alcohol, or ether is expelled from a
solution by heat, by exposure to the air, or in vacuo. If the dissolved substance is
more volatile than the solvent, the concentration is effected by distillation, the more
concentrated liquid being then found in the distillate, as in the rectification of hydrated
alcohol and of volatile ous dissolved in water. In the case of aqueous liquids, concen-
tration is sometimes effected by freezing out the water ; in this manner, a strong solu-
tion of salt may be obtained from sea-water ; strong spirit from vinous liquids, &c.

A similar principle is applied to the separation of silver from lead. The argenti-
ferous lead is melted and left to cool, till about two-thirds of the mass is soHdified ;
this consists of nearly pure lead, the portion which still remains liquid being an alloy
richer in silver than the original mass. By repeating this operation several times, the
alloy at last becomes sufficiently rich in silver to be treated by cupellation.

An organic constituent of the shells of certain molluscs, first
observed by Fr^my. It closely resembles keratin, or epidermose ; does not yield gelatin
by boiling with water, even under strong pressure; is insoluble in water, alcohol, ether,
acetic acid, dilute mineral acids, and potash-ley. It contains 60 per cent, carbon,
6 hydrogen, and 16 to 16 '7 nitrogen, a composition very near to that of epidermose :
whether it contains sulphur does not appear to have been made out. A similar sub-
stance, but containing only 12 or 13 per cent, nitrogen, was found by Schlossberger in
the byssus of acephidous moUuscs.

COWCRSTZOVSv AVZBUJL. This term is applied to aU deposits in the animal
body which are destitute of distinct organic structure. They are almost always of
morbid character, a few only, as the brain-sand (the sabulous matter of the pineal
gland), the crystals in the auditory organs of most animals, and in the vertebral
column of frogs, appearing to occur in healthy animals.

Concretions are formed: — I. In the liquid secretions, as urinary, salivary, and biliary
calculi, concretions in the stomach and intestines, in the lachiymal ducts, the cavity of
the nose, the sebaceous glands of the skin (gouty concretions), &c. — 2. In the cellular
tissue of the organs, as m the brain, heart, veins, lungs, and indeed in all parts of the
body. These latter are formed by the gradual transformation of other morbid products
the animal matter of which is gradually absorbed, while the inorganic substance
remains, and is often increased by addition of fresh deposits. All concretions of this
kind have a very similar, indeed almost identical, constitution, consisting of a base
sometimes predominant, sometimes subordinate, of coa^ated fibrin, with deposits of
phosphate and carbonate of calcium, ammonio-magnesian phosphate and carbonate of
magnesium, in variable proportions. Another class of concretions allied to those last
mentioned, are the so-called asteromatose deposits in the coatings of the arteries,
especially of the aorta. They are sometimes, but not always, associated with calcareous
deposits, and form layers of yellowish-white colour, and very slight consistence.
They consist mainly of crystalline deposits of cholesterin.

The essential constituents of animal concretions are .

Uric add and its salts.
Xanthin and cystin.
Hippurates and benzoates.
Cholesterin and fat.
Bile-pigment or cholochrome.
Fibrin.

Phosphate of calcium; ammonio-magnesian phosphate ; oxalate of calcium ;
carbonate of magnesium.

The following substances occur as cements or less essential constituents : urinary
and gall-bladder mucus, albumin, blood-red, the biliary adds, animal matter of inde-
terminate character, and sometimes soluble salts.

The chemical anidysis of animal concretions must always be preceded by an examina-
tion of their physical structure. They are very often made up of concentric layers of
substances differing in chemical constitution, so that it becomes necessary to make a
separate analysis of each layer.

As respects their behaviour when heated, concretions are distinguished as — 1. Per^
fecUy e&7nbu8tibU. — 2. ParUaUy combuBtible. — 3. IncoTnbusiihle, Their special chemical
charactezB are given in the following tables. (Handw. d. Chem. ii. [2] 171.)

4 b2

eONCBETIONS : ANIMAL.

io b5 i-d if3S i 4 A

•!||-;°3'1^;|J

|.a.a3--a|.r;i|«i

^llllllllll-sl

l.|'s-BSl-a||j

||41Hfltl

=^111' ill J

III

'51

CONCRETIONS: ANIMAL.

■si

liljl

•2 I 5 a

1111

'I "III 111

ISi" all Kail III
"I ill -I sill ill ^'

1 1 10 CONDENSATION — CONGLOMERATE.

COSraVSATIO V. This tenn, in its moot general sense, implies ineretse of
density, but it iB'often restricted to the passage of a gas to the liquid or solid state.

COVnSOSZTB. See Chomdbodits.

COMUmWKMXTM, A mineral containing copper and aisenic, originallj obtained
from the Condorrow mine near Helstone, in Cornwall ; since found in the Hnel Druid
mine, near Redruth ; also in mines at Coqnimbo and Gopiapo, Chili. It forms amor-
phoos, zonndish, flattened nodales» with fliU; conchoidal firactore, brownish-black eoloor,
blnish-black on the outer sur&oe^ opaque, dull or with glimmering faistze; streak m»-
taUic ; powder brownish-black ; soft. Specific gravity, 4*2 — 6*2.

Condurrite has been frequently analysed, but with very Tariable results ; in fact it
appears to be a mixture resulting from the alteration of Domg^kite (Cu'As), and mainly
consisting of a hydrated cuprous arsenite mixed with small quantities of manganese,
sulphur, iron, and silica. (Kopp^ Handw. d. Chem. ii [3], 173.)

COVCOOIKSBATa. A geological term applied to masses of rounded fragments
of older rocks held together by a cement ; if, on Uie other hand, the fragments are for
the most part sharp-edged, the mass is called breccia. Conglomerates are distin-
guished as quartzose, oJcareous, dolomitic, granitic, syenitic, &C., according to the
nature of the component fragments : the cement may be siliceous^ calcareous, or argilla-
ceous.

ADDENDA

C*H*. A gaseoufl hydrocarbon, which appears to hare been
first obtained by E. Davy (Kecords of gen. Sci. Nov. 1836; Gm. yiii. 150),
though in an impure state, by the action of water on the black substance which
passes over in the preparation of potassium; but its preparation in the pure
state, and indeed the estaolishment of its existence as a definite compound, is due to
Bert helot (Institut, 1859, p. 410; 1860, p. 565 ; R^p. Chim. pure, ii. 222 ; Ann. Ch.
Pharm. czv. 116), who obtained it by passing ethylene-gas, or the vapour of ether,
alcohol, aldehyde, or wood-spirit, through a red-hot tube, and by the action of red-hot
copper on chloroform. Ether yields it in largest quantity, but by whichever of the
preceding methods it is produced, it is always mixed with a considerable quantity of
other gases, and requires to be purified by passing the gaseous mixture into an
ammoniacal solution of cuprous chloride ; a red precipitate is then formed which, when
decomposed by hydrochloric acid, yields pure acetylene.

Berthelot has farther shown £bat acetylene is one of the constituents of coal-gas, and
that it may be formed by the direct combination of carbon and hydrogen, viz. by
passing hydrogen gas over charcoal, heated to whiteness by the passage of the electric
arc.

Acetylene is also produced : a. By the action of alcoholic potash on monobromethy-
lene (voL u. 569), C«H*Br - HBr « C«H« (Sawitsch, Compt. rend. lii. 157), or on
bromide of monobromethylene (C^'Br'), bromacetylene, C*^Br, being formed at the
same time (Reboul, Ann. Gh. Pharm. cxxiv. 267)u — 5. By passing the vapour of
monobromethylene into an ammoniacal solution of nitrate of silver, in which case a
precipitate is formed consisting of the silver-compound of acetylene CH'Ag' (more
probably CHAg), which, when treated with dilute hydrochloric acid, yields acetylene
(Miasnikoff, Ann. Ch. Pharm. cxviii. 330). — e. By heating monobromethylene with
ethylate or amylate of sodium, the products being bromide of sodium, ethylic or amylio
alcohol, and acetylene (Sawitsch, see vol. iu p. 569.)

C*H«Br + C»H"NaO - NaBr + C'ffH) + C«H».
Brometbylene. Amylate of Amyltc Acetylene.

•odium. alcohol.

d. When a mixture of marsh-ga^and carbonic oxide is passed througn a red-hot tube.
(Odling.)

. CH* + CO - C«H« + HK).

Acetylene is a colourless gas of specific gravity 0*92, having a peculiar and
unpleasant odour, moderately soluble in water, not condensed by cold or pressure. It
bums with a very bright and smoky fiame, 1 vol. acetylene consuming 2{ vol. oxygen^
and producing 2 voL carbonic anhydiide. When mixed with chlorine^ it detonates
almost instantly, even in diffiised daylight, with separation of charcoal.

Acetylene unites with copper and with silver^ forming detonating compounds,
which are produced on passing the eas into the ammoniacal solutions of cuprous
chloride ana nitrate of silver respectivd,y. The copper-compound is red, the silver- •
compound grey ; both are decomposed by hydrochloric acid, with separation of acetylene.
Acetylene mixed with air, and in presence of moisture, rapidly attacks metallic copper.
The gsB is absorbed and the copper becomes coated with a black deposit which
explodes violently when heated. Ulie formation of this substance (acetylide of copper
mixed probably with cuprous oxide) is doubtless the cause of the dangerous explosions
which sometimes occur in the cleaning out of copper gas-maina after long use. (Crova»
Compt. rend. Iv. 435 ; J. pr. Chem. Ixxxvii. 124.)

1112 ADDENDA.

Ajsetylene mutes with tuueent k^droaen, and is oonTerted into ethylene CH*. TUs
change is bzongfat about by snbjectug the copper-compoond of acetylene to the action of
hydrogen erolved by the action of xinc on a^jneons ammonia; the hydrogen eTdred
fiom acid liqaida does not prodnce this roaction.

Acetylene unites, like ethylene, with 6fwwtiM', sulphuric add, and the elements of
iDater^ forming with bromine the compound U*il»JJr*, with sulphuric acid, acetyl-sul-
phuric acid CH*.H^O\ and with the elements of water, acetyl-alcohol CH*.
H«0 - C*H*0. (Berthelot)

Aoetylsuiphurie add, CH*SO\ is produced by brisk and long-continued agitation of
acetylene with strong sulphuric acid. If the liquid be then ear^ully diluted, satorated
with carbonate of iMirium, and the filtrate evaponted, acetyl-su^hate of barium is
obtained in crystals. (Berthelot)

Aeetylte alcoM, C>H«0 « CH*M.O, is obtained by distilling and rectifying the
acid liquid just mentioned, as an easiW decompoeible liquid resembling acetone, but
having an extremely pungent odour, it is somewhat more volatile than water, auid is
separated therefrom by carbonate of potassium, but apparontly not by diloride of
eaiciuuL (Berthelot.)

BromaeeiyUne, (THBr. (Reboul, Ck>mpt rend. It. 18d.) — Produced by the
action of alcoholic potash on dibromide of dibromethylene :

C«H*Bi«.Br* - HBr - Br* - CHBr.

Also, together with acetylene and dibromethylene, by the action of boiling alcoholic
potash on dibromide of monobromethylene.

C*H*Br.Br» - HBr « C«H^r*.

Dibrouethylene.

C*H*Br* - HBr = C*HBr.

C*HBr.Bi» - HBr -Br* « CH*.

Acetylene.

It IB spontaneously inflammable, liquefies under a pressure of three atmospheres, is
soluble in water, and very soluble in dibromethylene, whereas acetylene is much less
soluble in that liquid. This property may be rendered ayailable for the separation of
acetylene and bromacetylene.

It unites with 6romtn^, forming the dibromide of bromacetylene, CHBi* ■»
CHBr.Br'. When passed into ammoniacal solution of cuprous chloride, it yields a
precipitate of cuprosacetylene, CHCcu:

C*HBr + 8Cu*Cl - CHCcu + CuBr + 3Cna;

which, when treated with hydrochloric acid, yields a gas haring the oompositioiL and
most of the properties of Berthelofs ace^lene, but differing scnnewhat in its behaTiour
to bromine, with which it yields the compound C"H*Br*, and a small quantity of CHBi'.

A3bliT&sra> CH^. This compound, homologous with acetylene, is produced,
in like manner, hf the action of ethylate of sodium on monobromotri^ene, CH'Br.
The materials are made to react in a well-cooled, sealed flask, and on opening
the vessel, a laige quantity of gas escapes, which, when passed into an ammo-
niacal solution of cuprous chloride, produces a yellow precipitate. This precipitate
decomposed by hydrochloric acid yields pure ally^e, a oolouriess gas, naving an
unpleasant odour, buniing with a smoky flame, and forming with fnercurous saUs a daik
grey precipitate, and with differ salts a white precipitate which detonates when heated.
The copper compound above mentioned bums with a reddish flame, and is decom-
posed with incandescence by bromine. (Sawitsch, CompL rend. EL 399 ; Ann. Ch.
Pharm. czix. 185.)

Allylene is also produced by passing the vi^)Our of bromotritylene into a hot con-
centrated alcoholic solution of potash. The gas thus evolred forms in ammoniacal
silver-solution, a precipitate consisting of a dark yellow compound, silver-acetylene-,
and a heavier white compound which is sUver'allylene, CH^Ag*. The gas erolved
from this compound by the action of hydrochloric acid, forms with bromine an oily
liquid, which boik, with partial decomposition, between 180^ and 200^ C, and has
the composition of a mixture of CH^Bz' and CPH^Bi^. (Morkownikoff, BulL
Soc. Chim. 1861, p. 90.)

CJBSZmir. Symbolf Cs. AtoTnic umgkt, 133. — A metal belonging to the same
group of elements with Uthium, sodium, potassium and rubidium. Its existence was
detected in 1860 by Kirchhoff and Bunsen, by help of the method of spectral analysis
which they introduced (see Spbctruii, Sfbctsax. Akaltsis). The compounds of
csBsium so closely resemble the coiresponding compounds of potassium and rubidium,

CiESIUM. 1118

that no differenee can be pereeiTed between them by ordinary analytical means ; but
in the spectram-apparatiis a few thonaandths of a milligramme can eaaily be detected.
The most characteristic lines in the oesinm-spectram are two blue lines Cs a and Cs /3,
in the neighbourhood of the strontium-line, Srd; they can be clearly seen, even with
silicate of cssium, and the name Casium^ from cmsiuSt sky-blue, has been chosen as
recalling their colour.

Cseeium hasttot yet been found, except in company with rubidium (see HuBmnTic),
and it occurs in even still smaller quantities than the latter element. Caesium was
first detected in the Diirkheim mineral water, ten kilogrammes of which contain not

Suite two milligrammes of chloride of caesium. Kreuznach water contains less, and in
tie lepidolite of Bosena (which is the principal source of rubidium) only insignificant
traces of it are found. (Kirchhoff and Bunsen, Pogg. Ann. cziii. 363 ; Jahresber.
1861, 177.)

The most abundant source of it yet disooTered appears to be the lepidolite of Hebron,
in Maine, U.S. This mineral occurs there in la^ quantity in a coarsely crystalline
granite, associated with red and green tourmaline and albite. It has a granular, and
at the same time foliated o^staliine structure, a pale rose to Tiolet colour, and very
d^stly resembles the lepidohte of Penig, in Saxony, and, like that, is also associated
with ihe rare species, amblygonite. It contains rather more than 0*3 per cent, of
caesium, and as much rubidium as the lepidolite of Bozena. (O. B. Allen, PhiL Mag.
[4] zzY. 189.)

Caesium has also been found, in comparatiyely large quantity, in the mineral waters of
Baden-Baden rBunsen), Bourbonne-les-Bains, Haute-Mame (Gran dean, Ann. Ch.
Phys. [3] Ixrii. 177), in the salines of Aussee, and in the lithium-mica of Zinnwald
(Schroetter, Wien Akad. Ber. xUv. 218). It exists in •perceptible, but generally reiy
small, quantities, in several other minerals, as triph^hne (Blake, SiU. Am. J. [2]
xxxiii. 274; Grandeau),camallite(Erdmann),petalite(Grandoau),in the mineral
water of Vichy (Grandeau), in those of Topusco and Lassii^ja (Schneider, Wien
Akad. Ber. xlv. 483), and in the salines of Ebensee. (Bedtenbacher, ibid, xUv. 1 53.)

The separation of caesium from sodium and potassium depends upon the exceedingly
slight solubility in water of its chloroplatinate. In order to obtain it pure^ it is preci-
pitated, together with chloride of potassium and chloride of rubidium, by means of
chloride of platinum, from the mother-liquor, freed frt>m everything except alkaline
salts, obtained by the evaporation .of Durkheim water (Bunsen operated with the
residue of about 40,000 kilogrammes of water^ ; the precipitate is boiled with a very
small quantity of water, allowed to settle, ana the stul hot solution decanted ; when
this operation has been repeated twenty times, the mixture of chloroplatinates of caesium
and rubidium which remains undissolved is reduced by heating in a stream of hydrogen,
and the chlorides of those metals are extracted fix>m the resioue by boiling water. To
separate the rubidium, the chlorides are transformed into carbonates, and the dry mix-
ture of salts repeatedly exhausted with absolute alcohol, in which carbonate of caesium
is soluble, but carbonate of rubidium insoluble. As the carbonate of caesium so obtained
may still contain smaU quantities of pot^tssium and rubidium, it must, for com-
plete purification, be treated with sufficient baryta-water to render about four-fifths
of it caustic, evaporated in a platinum dish, and tiie residue extracted with the smallest
possible quantity of alcohol, which dissolves hydrate of caesium, but leaves the carbo-
nates of potassium and rubidium behind. When this operation has been repeated
until the product^ examined in the spectrum-ai^MiratuSj no longer gives the potassium
and rubiouum reactions, or gives them only very feuntly indeed, the further treat-
ment of it is found not to alter its equivalent weight ; although the salt thus obtained
is still a mixture of the chlorides of caesium and rubidium, and not pure chloride of
caesium, as Bunsen at first supposed {yid, i^fr.).

The following process is given by Allen {loc, cit) for the extraction of caesium from
the lepidolite of Hebron. Ten parts of the mineral, pulverised until it will pass
through a sieve of 20 holes to the linear inch, are mixed with forty parts of , coarsely
powdered quicldime ; a Quantity of water sufficient to slake the Ume is next mixed
with as much hydrochloric acid as will convert from six to seven parts of the lime
into chloride of calcium ; the two mixtures are then united, and stirred vigorously
during the slaking, thus intimately blending the mineral with suitable proportions of
dry hydrate of lime and chloride of calcium. The mixture is put into Hessian
crucibles, and heated to redness for six or eight hours (a shorter time would probably
suffice). During the ignition, care must be taken to prevent the heat rising much
above redness, as loss woidd then occur by volatilisation of the alkaline chlorides, and
by the ftision of the mass and its consequent absorption into the crucibles. The pro-
duct of this operation is detached from the crucibles, and boiled with water till all but
a trace of the chlorides' is removed. The solution thus obtained, containing chloride
of calcium and alkaline chlorides, is evaporated till crystals begin to form ; sulphuric

1114

ADDENDA.

acid is then added as long as Bolphate of caldom separatefl, excess of acid being
avoided, and the whole mass is eyaporated to diyness, and strongly heated, to expel free
hydiochloric acid. The residue is treated with water, the small quantity of sulphate
of calcium whi6h passes into solution is precipitated by a carbonate of ammonnun, the
precipitate is filtered o£^ and the £Qtrate is a^ain eyaporated to dryness and ignited.
In thin way a mixture of the chlorides, containing also small quantities of the sulphates,
of sodium, Uthium, potassium, rubidium, and csesium is obtained, fmm which the
chlorides of the last two metals can be separated by treatment with bichloride of
platinum as directed by Bunsen.

For the separation of csBsium from rubidium, Allen recommends the following
process. The chlorides of the two metals are oonverted into sulphates, and then into
carbonates, by precipitating with caustic baryta and saturating the solution wilii
carbonic add. From the carbonates, the add tartrates are prepared by adding to the
solution twice as much tartaric add as is neoeesary to neutraJiBe it^ and these salts
can then be separated from each other by fractional crystallisation : add tartzBte of
rubidium requires for solution about eight times as much water as does add tartmte
of «»*i«"i, and therefore crystalliBes out first, while the latter salt aoemnulates in the
mother>Uquora. The salts of the two alkalis may be thus separated from each other
so completely that neither shows any trace of the presence of tne other when examined
with the spectroscope.

Pure metallic cesium has not yet been obtained, but an amalgam of csdum can
be easily procured by electrolysing a solution of chloride of caesium, using merenxy as
the negative pole. Cndum-amalgam decomposes water in the cold, and when exposed
to the air, sets hot and covers itself with a coating of deliquescent hydrate of caesium.
When caesium-amalgam is connected with potassium-amalgam or with mbidinm-
ameJgam and water, so as to form a galvanic circuit, it shows itself to be more elec-
tropositive than dtJier of them ; csesium is therefore the most electropodtiva element
yet known.

Bromoplatinate of Casium readily separates, together with the rubidium>salt,
when dibromide of platinum is added to a dilute solution of the chlorides of the two
metals. If potassium is present^ the bromoplatinate of that metal is carried down
likewise. (Allen.)

Carbonate of ChBsium^ Cs*CO' + aq. — Confhsedly developed crystals, which give
an anhydrous sandy powder when heated. Dissolves in 9*1 pts. absolute alcohol at
19° C, and in 6 pts. at 78*4^ C. ; very caustic ; deliquesces in the air aind gradually
becomes converted into add carbonate ; dissolves in water in nearly all proportions
with the aid of heat.

Acid carbonate of Casium, CsHCO*. — Tolerably well-formed, but not measur-
able prismatic crystals, permanent in the air, of a glassy lustre. Keacts hardly alkaline ;
by ignition it is easily changed into the neutral salt.

Chloride of Casium, CsCL — Crystallises in cubes, which deliquesce in the air
like chloride of lithium, and can thereby be distinguished from chloride of potassium
or of rubidium. When gently ignited, chloride of caesium easily melts ; it is somewhat
volatile, and in the air easUy becomes somewhat alkaline. (Bunsen.) According to
Johnson and Allen pure chloride of csesium is not deliquescent.

Chloroplatinate of Casium^ OsCIPtCl*. — ^Bright yeUow sandy powder, com-
posed of shining, transparent, microscopic regular octahedrons. It is more difficultly
soluble than the chloroplatinate of either potasdum or rubidium; the following table
gives the solubility in 100 pts. water of the three salts, as determined by Bunsen, the

Temperature.

Fotauium-aalt.

Rubidiiim-Mlt.

C«Hlam-ialt.

o°(i .

0-74

0184

0-024

0-90

0164

0-060

0141

0-079

1-41

0146

0110

1-76

0166

0-142

217

0-203

0-177

2-64

0-268

0-213

319

0-329 •

0-251

3-79

0-417

0-291

4*46

0-621

0-332

100

618

0-634 .

0-377

C-ZESIUM. 1115

csBsitimHMiltB haTuig been pmrified by the first prooeeSi and therefore stOl oontaining a
little mbidium.

Hydrate of Caaium^ CsHO + aq.— Confusedly mstallised, deliquescent, exceed-
ingly caustic At a red heat it does not become anhydrous ; it attacks platinum, is en-
tirely volatile when heated on a platinum wire, and is easily soluble in alcohol.

Nitrate of Casium, CsNO*. — Contains nowaterof cxystallisation, is isomozphoiu
with nitrate of rubidium and not with nitrate of potassium. The crystals are hexagonal
prisms combined with the hexagonal pyramid P: F in the terminal edges s 142*^ 56';
in the lateral edges » 78^ 68'. Bates of axes, 1 : o » 1 : 0*7135.

P. ooP.P2. ooP2.0P.fP.

The salt has a cooling saline taste, like that of saltpetre, and is soluble in ten times
its weight of water at 3^ C. (B u n s e n.)

Pier ate of Caeium Testmhlea the corresponding potausium-salt It cannot be
separated from picrate of rubidium by crystallisation. (Allen.)

Sulphate of Casium, Cs'SO\ forms anhydrous, ill-defined, hard crystals, grouped
together in bunches, and permanent in the air. One part of the salt dissolyes in 0*63
pts. of water at — 2^ C. (1 pt of sulphate of potassium dissolyes in 12*5 pts. of water
at the same temperature.)

Sulphate of csesium forms double salts with sulphate of magnesium, sulphate of
oobal^ &C., belonging to the type KMgSO' + 3HK), and is isomorp^ous with the cor-
responding potassium- and ammonium-compounds. CsCoSO* f 3M'0, shows the fol-
lowing surfaces : OP . ooP . + P . [P oo] . + 2P oo . qoP2. Sulphate of caesium forms,
with sulphate of aluminium, an alum crystallising in regular octahedrons of a glassy
lustre. (Bunsen, Ann. Ch. Pharm. cxix. 111.)

Acid tartrate of Casium, C*E.H)80*, — Colouriess, transparent^ flattened prisms,
which do not diminish in weight when pulverised and dried at 100°. One part of this
salt dissolves in 1*02 pts. of 1x>iling water, or in 10*32 pts. of water at 25° Cf. (Allen.)
The neutral tartrate is very deliquescent. (Bunsen.)

Atonde weight of Casium, — The atomic weight of csesium has been determined by
the analysis of its chloride. This salt, purifi^ from chloride of rubidium by means
of chloride oif platinum in the manner already described, was found by Bunsen to
contain :—

Chlorine. Cadain.

After the 1st purification, .... 22*334 77*666

„ 2nd „ .... 22*334 77*666

„ 3rd „ .... 22*316 77*684

whence he deduced 123*4 for the atomic weight of csesium. Subsequent experiments
by Johnson and Allen (Phil. Mag. [4] xxv. 196) have shown that the chloride of
caesium used for these determinations still contained chloride of rubidium, and that the
atomic weight calculated from them is consequently too low. Their analyses of
chloride of csesium, prepared from the acid tartrate purified by concentrating its solu-
tion and recrystallisation, gave the following results : —

Csfium.
78-966
78-969 •
78*957
78-937

Bunsen has since published new determinations (Pogg. Ann. cxix. 1) which agree very
dosely with these. The chloride of csesium used for them was prepared by the follow-
ing process, from a mixture of the chlorides of csesium and rubidium which had been
/previously completely freed from potassium, sodium, and lithium. The chlorides were
first converted into carbonates, and then a little more tartaric acid was added to the
solution than was needed to convert the csesium into neutral tartrate and the rubidium
into the acid salt (the quantity of acid requisite being deduced from a preliminary
determination of the amount of chlorine in the mixed chlorides). The liquid was next
evaporated to dryness, and the powdered saline mass exposed to moist air in a f\mnel
stopped with a small filter. In this way a solution of the very deliquescent tartrate of
caesium was obtained, while the acid tartrate of rubidium remained as a solid salt in
the funnel. The tartrate of csesium was converted into chloride, precipitated with
bichloride of platinum, the precipitate washed and decomposed b^ heating in a stream
of hydrogen, and this process was repeated until the proportion of chlorine in the

Chlorine.

21*044

21031

IIL

21*043

IV.

21*063

1116 ADDENDA.

TCsnltii^ Monde of eaBaam did not alter anj longer. The prodnet 00 prepmed

Alter the 4tli purifiemfion, .... 21-057 78943

„ 6ih „ .... 21-045 78-955

„ 6th „ .... 21-052 78-948

Taking Aga 107-94 and CI » 35*46 (Staa), the mean cf Johnaon and Allen's experi-
Benta givea 133-03 fiir the attHnie weight of caeaiam, while the mean of Bansen's mosi
reeent cxperimenta girea 132-99, ao mat wb may take Oaal33-0 as being xtrj near
tbetrath.

On the apctUiun of eaesinm, see Johnacn and Allen (PhiL Mag. [4] xxr. 199), and
^■>B**> (^<n- ^'^ °^ 6).— O. C. F.

INDEX

THE FIRST VOLUME.

PAGE

Abicbite 1

Abietic add —

Abietin •—

Abrazite —

Absinthin 2

Absorption of gaaea (s. Gaaes).

Acacin —

Acadiolite —

Acajoa —

AcaroTd re«in —

Acechloride of Platinam (a. AcetonOi de-
compositions of).

Acediamine —

Acephosgenic and Acephoosic acids . 8

Ac«tal —

Cbloracetals 4

Acetamide 5

* Cbloracetamide .... 6

Diacetamide 7

Etbylacetamide (s. Ethylamine).

Mercaracetamide .... —
Phenjlacetamide (s. Phenylamine).

Acetone —

Acetic add —

Acetates ...... 12

of Alaminiam ..... 13

Ammoniam —

Barium —

Bismuth —

Cadmium —

Calcium —

Cerium —

Chromium ..... 14

Cobalt —

Copper —

Iron —

Lead 16

Lithium 17

Manganese ^-

Mercury —

Nickel —

Potassium •...• —

Silver 18

Sodium —

Strontium .....—

products of

Acetates of Tin .

Uranium

Yttrium

Zinc .
Acetic acid, substitution
Acetic anhydride .
Aceto-benzoic uihydride . •
Aoeto- dnnamic anhydride .
Aceto-cnminic anhydride
Aceto-salicylic anhydride
Acetic ethers

1. Monatomic;

Acetate of ally] .

Amy] .

Benzyl

Ethyl .

Chlorinated acetates of Ethyl

Methyl

Chlorinated acetates of Methyl

Acetates of Octyl

Phenyl

Tetiyl

Trityl

2. Diatomic:

Acetates of ethylene, amvlene,
benzylene, tet^lene, and tri-

tylene

• 8. Triatomic: AetHns

Monacetin

Diacetin

Triacetin

Acetochlorhydrin .

Acetodichlorhydrin

Diacetochlorhydrin

Acetochlorbromhydrin

Acetite

Acetometer

Acetone

Substitution-products of Acetone :

Chloracetones . . • .

Bromacetone • . • .

lodacetone

Methvlacetone . • • •

Ethyfacetono . • . •
Acetones or Ketones . • • .

PAOB

22
28

29
81

1118

INDEX TO

34
85

FAOB

Acetonine 82

Acetooitrile —

Acetony] 38

Acetosyl —

Acetoxyl —

Acetiimd —

Acetvl —

l^romide of Acetyl .
Chloride of Acetyl .
Hydride of Acetyl .
Iodide of Acetyl
Peroxide of Acetyl .

AcetvlouB acid

Achillea millefoliam

Achilleic acid —

Achillein —

Achirite (a. Dioptase).

Achmite or Acmite . . . . —

Acfarolte. — ^Achtarandite ... 87

Acibromidea, Acichloridea, &c. (a. Oxy-
bromides, Oxyebloridea, &c) • . —

Aciculite —

Acidimetiy —

Acids 89

Aconitic acid 64

Aconitates rmetallic) ... —
Aconitate of ethvl .... 55
Aconitanilic acid .... —

Aconitodianil —

Aconitanilide ..... —

Aconitine —

Aconityl 56

Acrene —

Acrolein ....... —

Acrolein-ammonia .... 57

Acrolein with acid sulphite of sodium —
Hydrochlorate of acrolein • . —
Metacrolein .... —

Acrylic acid •

Acrylates 58

Actinolite (s. Hornblende).

Adamant (s. Diamond).

Adapter or Adopter . . • . —

Adhesion (s. Cohesion).

Adhesive slate (s. Slate).

Adiaphanous spar (s. Gehlenite and SaoB-
Rurite).

Adinole ....

Adipic acid .

Adipates

Adipocere . . •' . . .59

Adularia. — .fidelforsite .

Aegirin, or Aegyrin

Aerated Waters (s. Carbonic
Water)

Aerolite (s. Meteorite) .

Aerugo (s. Acetate of Copper ;

Aescnynite

Aesculetin, or Escaletin

Aesculic acid

Aesculin, or Escnlin .... 60

Aethal (s. Cetyl) .

Aether, Aethyl, &c. (s. Ether, Ethyl,
&c) ....

Aethiops

Aethokirrin .

Affinity (s. Chemical Affinity)

Aitonite (s. Aphtonite) .

Agalmatolite .

Agaphite. — ^Agar-A|par .... 61

Agaricin (a. Amanitin) .

Agaricus

Agaricns Mineralis . • . . 62 |

Agate ....

Acid

Yerdiflpns)

and

-1

PAOB

AgedoiL — Agnesite . . . 62

Agrostemmine —

Aikinite. — ^Air 68

Aiuga reptans . . . . • —

Ajumticon. — ^Akcethin (a. Acetone) . —

Akmite (s. Achmite) . . . . —

Akontite. —

Alabandin (s. Manganese-gUmce) . —

Alabaster —

Alalite (a. Diopside) .... —

Alanine —

Alantin (s. Innlin) .... 64

Albene . —

Alhin (s. Apophvllite) .... —

AlbiU (s. FelspM") —

Album grscum • . . • • — ~
Albumin ... . . .65

Albuminates 68

Albumin, vegetable . • • • 69

Albuminin 70

Albuminoids —

Albuminose ...... 73

AIcarrazRS —

Alchemilla Tulgaris .... —

Alcohol —

Alcoholates &i

Alcohol- bases ' 81

Alcoholometry —

Alcohol- radicles 96

Alcohols 97

Monatomic alcohols . . • —
Diatomic alcohols : Gfycols . . 102
Triatomic alcohols : Glycerins . 1U3
Alcohols not included in the prece-
ding groups .... 104

Aldehyde 105

Aldehydates 107

Aldehyde-ammonia ... —
Compound of aldehyde with acetic

anhydride 108

Modifications of aldehyde: Elal-

dehyde, metaldehyde,'8cc. . . 109

Aldehyde-resin .... —

Aldehydes 110

Aldide 112

Alembic .113

Alembroth-salt •—

Alexandrite (s Chrysoberyl) . . —

Algaroth-powder .' . * . • . —

Algerite ... . . —

Alimentary Substances (a. Kutrition) . —

Alismin —

Alixia-camphor —

AUzaric add —

Alixarin. — Aliaite (a. Pimdite) . . —

Alkali 115

Alkalimetry 117 .

AlkaloTds 120

Detection of, in chemioo-1^^ in-
vestigations .... 125

Alkanet 128

Alkai^n and Alkarsin (s. Anenio-

radicles Organic^ p. 403) ... —

Allagite. — Allaite —

Allanite (s. Orthite) . . . . ^

Allantoic and Amniotic liquids . . —

Allantoin 180

AUanturic acid 132

Allemontite ...... —

Allituric acid —

Allium sativum —

AUochroIte. — ^Allogonite ... —

iAIlomorphite —

Allophano —

THE FIRST VOLUME.

-1119

PAGE

AHophanic add . . . . . 132

Allopbanates (metallic) • . —

Allopbanic ethers .... 183

Adiophanate of Amyl ... —

Ethyl . . . •—

Ethylene . .131

Glycervl . . —

Methyl ... —

Eugenic acid . . —

Allotropy (a. Iflomerism) . • . 185

Alloxan -.-

Alloxanic acid .... 187

AJloxantin 138

Tetramethvl-alloxantin . . • 140

Alloys (s. Metals^ ..... —

Allnaadite (s. Tnphyline) . . . —.

AUyl.— Allyl-alcohol . . . . —

Allyl : Bromides of .... 141

Chlorides of .... 142

Hydride of —

Iodides of —

Oxide of . . . . . —

Oxygen-salts of . . . 143

Salphide of: Oil of Garlie . —
Ikletallic compounds of Salphide

of Allyl 144

AUyl and hydrogen. Solphide of AUyl-

mereaptan 145

Allyl-sulphocynate of (s. Salphocyanic

ethers^ ...... ~-

Allyl-sulphocarbamic acid: Su^osm^

ofne acid —

Allyl-sulphocarboniCy or Allyl-xanthic

acid 146

Allyl -area (s. Carbamide^ p 754) . . —

AUylamine , — -

Diallylamioe —

Dibromallylamine .... —

Ethyl 'dibromallylamine . . —

Triallvlamine —

Tetraflylium —

Tetraliylarsoninm . . . —

AUylene 147

Chloride.— -Acetate .... —

Almagrerite. — Almandine ... —

Almonds, oil of —

Aioeretic acid (s. Aloetic acid p. 148) . —

Aloes —

Aloetic acid 148

Aloln . . .... —

Aloisol —

Alottchi or Alachi-reain .... —
AJphene, salphide (tf (s. Sulphocyanide of

ammonium) 149

Alstonite —

AlUite —

Althein —

Althionie acid ..... —

Aludels —

Alum (s. Snljphates) .... —

Alumina (s. Oxide of aluminium, p. 157) —

Alaminates • —

Aluminite —

Aluminium —

Preparation ftom the chloride . 150

Cryolite . 151

Redaction by hydrogen or carbon . —
Preparation by electrolysis .152

Properties J58

Uses 154

General characters and reactions of

aluminium compounds . . —
Quantitative estimation of alumi-
nium • . . . , • 155

PAOB

Aluminium, alloys of . . . .155

Arsenide 156

Boride —

Chloride —

Fluoride 157

Iodide —

Oxide: Alumina .... —
Hydrates of, or of Alumina . .159

Alaminates 160

Oxygen-salts of aluminium . . —

Phosphide of aluminium . . —

Silicide of aluminium ... —

Selenide of aluminium . . . ..

Sulphide of aluminium ... —

Alumo-calcite —

Alum*earth ......—

Alum-slate .—

Alunite or alum-stone. — ^Alunogen . 161

Amalgam —

Amalgamation .—

Amalic acid ~-

Amaoitine —

Amarine -~

Amarine-salts 162

Diethylamarine . . . . .»

Trinitramarine .... —

Amarone —

Aman-l 168

Amarythrine —

Amasatin —

Amausite —

Amazon-stone ..... .^

Amber

Ambergris 164

Amblygonite ...... -^

Ambrein ...... 165

Amethanes — .

Amethyst ...... i—

Amianthold (s. Hornblende) . . —
Amianthus (s. Asbestos, p. 415).

Aroic acids —

Amides 168

Monamides 169

Diamides 172

Triamides 178

Amines:

Monamines —

Diamines 176

Triamines 177

Tetramines and Pentamines . . »
Phosphines, Arsines, Stibines . .178
Alkalamides :

Monalkalamides ......

Dialkalamides 180

Trialkalamides .... 181
Amidin (s. Starch).
Amidogen (s. Amides, p. 168).
Amidooe (s. Starch).
AmmeHde, Ammeline (a. Melam).

Ammiolite 182

Ammonia ...

History, Sources, Formation .
Preparation, Properties, Decomposi

tions 183

Combinations :

1. With irater : Aqueout Ammaina . 184

2. With alcohol . . . .187
8. With metollic salts .

4. With acids . ' .

5. With polybasic anhydrides .
Ammoniacal salts, or Ammonium-salts . 187

Reactions of Ammonium salts .
Separation and Estimation of Am-
monium . • . • • .

1120

INDEX TO

PAGE

Ammoniacal salts : Acctalet • . .190

Carbonates . . . * . —

Chloride 191

Hydrate 192

Nitrate —

OxaUtes —

Phosphates 193

Sulphates —

Salphides —

Ammomam 194

Ammoniam-amalgain (p. 186).

Ammoniam-bases —

Polyammoninm -bases . . 19H

AmmoDiam-bases containing metals 1 98
Amniotic liquid (p. 128).

Amoibite 199

Amorphism ..>... —

Ampelicadd 201

Ampelin —

Amphibole (s. Hornblende).

Amphid salts —

Amphigene (s. Lencite) .... —

Amphilogite (s. Didrimite) ... —

Amygdalic acid —

Amvgdalin —

Amyl 202

'Bromide of Amyl . . . —

Chloride 203

Cyanide —

^3*drate of Amyl .... —

Aroylic alcohol .... —
Hydride of Amyl . . . .204

Ichlide of Amyl .... 205

Oxide of Em'yl: AmifBeeAer . —

Oxide of Amyl and Ethyl . . —

Methyl . . —

Potassiom —

Sodinm . . —

Sulphides of Amyl :

Protoaulphide and Disulphide . —

Sulphide of Amyl and Hydrogen :

Awud mereapioM . . . •—
Solphide of Carbonyl, Amrl» and

Hydrtw^en : Amfl'xa.'miiue add 206

Dioxysaiphocarbonate of Amyl . —

Telluride of Amyl .... —
Amylamines :

Amylamine —

SalU of Amylamine . . . 207
Amylsulphocarbonate of Amyliam —

Diamylamine —

Triamylamine .... —

Tetramyliam —

Amvlates (p. 205).

Amylene 208

'Acetate of Amylene ... —

Bromide —

Hydrate ...... —

Nitrylide —

Oxide 209

Amylene with Snlphar and Chlo-
rine:

Dichlorosulphide of Amylene . —

Disolphochloride of Amylene . —
Amylene with Sulpfanr and Oxygen :

Dianlphoxide of amyloie . . —

Anacardic add —

Analcime . ^ 210

Analvsis Inorganic :

Preliminary examination . . 218

Solution of solid bodies . 314

Qoalitatire analysis of solutions . 216

Examination for metals ... —

Exaininiuion for acids . . - . 222

237

238

PAOV

Analysis, Inorganic :

Qoantitative analv^:
Indirect method .... 224
Analysis, Organic . . . . *. 225
1. Elementary or ultimate analysis:
Qualitative analysis . . . _
Quantitative analysis :
Apparatoa and materials . 226

Preparation of the substance for

analysis 231

Estimation of Carbcn and Hydrogen :
In solids not containing nitn^en 232

In liquids 236

Hodifications in the case of
bodies containing nitrogen .
Modifications in the case of bo-
dies containing sulphur, chlo-
rine, brominciodine, or metals
Amount of error in the estima-
tion of carbon and hydrogen
Estimation of Oxygen .
Estimation of Nitrogen :
Uebig's comparatiTe method .
Bunsen^ oomparative method
Dumas's absointe method
Simpson's

Will and Varrentn^'s
Estimation of ChlcHrine
Estimation of Snlpbnr
Estimation of Phosphorus
Determination of the chemicsl
formula of an on^anic compound
n. Proximate organic wulym .
Examination of animal substaneei :
Zooehemieai amafytU .
Analysis (volumetric) of Liquids sod
^Uds:

I. Apparatus

n. Preparation of Standard solutioos
IIL Docription of Volumetric pro-

239
240
242
243
244
246
247

248
249

250

254
257

1. Analysis by Precipitation . . 259

2. Analysis by Saturation . 261
Anidimetry and Alkaltmetiy . 262

3. Analysis by Oxidation and Be-

dnctien —

a. With Permanganic add . . 263

h. With Iodine .... 264

Analysis (Volumetric) of Gases . • 268

Bunsen's apparatus . . . —

Williamson and Russdl's appamtns 274

Regnault and Beiset's apparatus . 275

Frankland and W^aid's apparatus . 279
Estimation of gases directly or by

absorption S^l

Estimation of gases indirectly or by

combustion . . . • 284
Analysis Zoochemical (pw 250).

Anamirtin 289

Anamirtic add . . . • —

Ananas, oil of . . . • • —

Anatase —

Anatta (a. Annotto).

Anauxite *-*

Anchoic add —

Anchoates 290

Anchusin or Anchusic add . . • —

Andalusite 291

Andaquies wax —

Andesin —

Andraolite (s. Harmotome).

Anemonin -*

Anemonic add ....''*

Angelica balsam ^

THE FIRST VOLUME.

112i

TAQB

Angelic acid 392

Angelates 393

Angelic anlijilride .... —

Angellcin —

Anglarite. — ^Angladte .... —

AnKusturine —

Annydrides —

Anhydrite 295

Anil —

Anilamic acid (a. Pbenylamic acid) . —
Anilides (& PhenylamideB).
Aniline (s. Phenylamine).

Anim^reain ~~

Animine. ••.... 296

Anion —

Anisal ^s. Hydride of Aniayl, p. 807).

Anisamic acid —

Anisamide . . . • . • . 297

Anisaminea —

Anisanilide (a. Phenylanisamide) —

Anise, oil of

Oil of anise and oil of fennel
Oil of tarragon . . ' . . 299
Bitter fennel
Anishydramide
Anisic add 800

Anisates (metallic) •

Anisic ethers 801

Bromanisic acid

Chloraniaitfacid .... 802

Nitranisic add .

Trinitranisic acid .... 808

Sulphanisic add
Anisic alcohol

Anisic anhydride . •

Anisidine 804

Nitranisidine .

Dinttranlsidine

Anisine (a. Anishydramide),

Anisoic acid .

Anisoin (s. Anise, oil of).

Anisol 805

Chlor- and Brom-anisol

l^Iitranisol
Di' and tri-nitraniaol ... 806
Anisnlmin

Anisaric add . . .
Anisyl ....

Bromide of Anisyl •

Chloride .

Hprdride . .... 807

Anken te. — ^Anoabergita
Annealing • . •
Annotto

Anode 808

Anorthite

Anotto (s. Annotto).

Anozolnin . •

Antbokirrin 309

Anthokyan or Gyanin .
Antholeucin .

Anthophyllite (a. Hornblende).
Antboaiderite
Anthoxantbin
Ai.tbracene or Antbradn (s. Para-
naphthalin).

Anthracite

Antbracolite or Antbraconite . . —

Anthracoxene

Anthranilic acid (s. Phenylcarbamic

Add, p. 751).
Antbropin . . . . , . 8io
Antiarin

Vol. I. i

PAOB

Antiar resin 3x0

Antichlor _

Antichloriatic theory (s. Chlorine) .

Antigorite 311

Antimonates (s. Antimony, Oxides of.

p. 825).
Antimonial Copper (s. Copper, Snlpbidea

of),
Antimonial copper glance .,...-.
Antimonial crocos (a. Antimony, Oxy-

snlphideof).
Antimonial lead-ores (s. Lead, Snl*

phidea of \.
Antimonial nickel and antimonial
silyer, (s. Antimony, Alloys of,
p. 816).
Antimonial sulphide of sUver (s. Silver,
Snlphide of).

Antimonite ^ . —

Antimonites (s. Antimony, Oxides of,
p. 823).

Antimony -.

History, Sources, Preparation . —

Purification 818

Testa for imparities . . .814

Properties 315

Amorphous antimony . . . ._
Antimony, Alloys of , . . .816

AntinM>ny Bloom 817

Antimony, Bromide of . . . , — -
Antimony, Chlorides of*

Trichloride

Pentachloride 313

Antimony, Detection and estimation of:

1. Blowpipe reactions ... —

2. Liquid reactions . . . .819
8. QuantiUtive estimation . , . 820

Atomic wdght of antimony . , 321

Valuation of antimony ores . . —
4. Separation of antimony from other

metals ^^

Antimony, Fluoride of . ... 82S
Antimony-glass (s. Antimony, Oxysal-

phide of, p. 328).

Antimony, Hydride or . . . . .
Antimony, Ores of (pp. 811, 321).
Antimony, Oxides a^i

Trioxide or Antimonioua oxide . 823
Tetroxide or Antimonoeo-antimonic

oxide 824

Pentoxide, Antimonic oxide^ or an-
hydride . . < . .

Antimonates and Metantimonates . 825

Antimony, Oxychloride of . . . 827

Antimony, Oxyidide of . , . . 828

Antimony, Ox3'^8nlphide of . . . —

Antimony, Selenide of . • , . —

Antimony, Sulphides of . . . 329
Trisulpbide, j\ntimonious sulphide,

or Sulphantimonious Anhydride —

1. Crystallised ... —

2. Amorphous: MinenU Kenne$ 380
Hydrated trisulpbide . . 881

Snipbantimonites . . 834
Pentasulpbide of antimony,
Antimonic sulphide or Sul-

phantimonic anhydride —

Suiphvitimonatea . . 335

Antimony, Solphochloride of . . 333

Antimony, Sulpbiodide of . . .

Antimony-radicles, Organic . . 339

Antimonides of Amyl or Stibamyls

Stibdiamyl 840

Stib-triamyl or TriamyKslibine . -^
0

1122

INDEX TO

841
844

845

847

848

AiiUmon3r-rtdide8,OrgMdc: page

AntiroonideB of Ethyl or StibethyU :

Stibtriethyl or Triethylstibino

Btibethyliam or Tetrethylstibo-.
nium • • • • •
Antimonides of Methyl or Stib-
methyls . . . •

Stibtrimethyl or Triethylsiibiiie

StibpenUunethyl

Stibmethyliam or Tetramethyl-
Btiboniam ....

Stibtriroethyltriethyliam •

StibmethTltriethyliam
Antiphlogistic theory (s. Combustion) .
Antirrhin (s. Anthokimn, p. 809).

Antirrhinic mdd

Antiseptics ......

Antitartaric acid

Antrimolite

Ants, oil of

Antvrrhimc acid

An3'lamide (s. Salicylamide).
Apatelite ......

Apatite

Apatold ......*

Apelaic add (s. Aselaic Acid\
Aphanesite (s. Abichite, p. 1).
Aphanite (s. Diorite)
Aphlogistic lamp (p. 74).

Aphrite • •

Aphrisite (s. Toarmaline).

Aphrodite ... • •

Aphronitram

Aphrosiderite

Aphtalose (s. Arcanite).

Aphtonite

Apiin • '

Apios toberosa . . • •
Apirin or Apj'rin ....
Amohnite.'ApUte ....
Aplome (s. Garnet).
Apuglucic acid (s. Glade Acid).
Apocreoic add (s. Humic Add).
Apophyllic add ....

Apophyllite

Aporetin

Aposepidin

849

850

851
852

ArctQTin • • • . .

Areca nnts

Arendalite (s. £pidote>

Arethaae

Arfvredaonite

Argal or Algol

Argentan • ....

Aigentammonimn

ArgULtine . .....

Argentine flowers of antimony
Argentite (s. Silver-glance).
Argillaceous earth (s. Alamma snd Clay).
Aigyrnta, — ^Argyrose ....

Aricine . . .....

Aristolochla Clematitia

Serpentaria
Arkansite (s. Brookite, p. 681) . .
Arki (s. Arsa).

Arkoee '

Armenian stone

Arnica, oil of

Aniidne . . . • • •

Arpidelite. — ^Arqneriie ....

Arrack

Arragonite • . . • • •

Arrow-root

Arsa

Arsenic:

History . . . . • . •
Occurrence, preparation, g^qierties.
Detection and estimation :
Reactions in the dry way .
Reactions in the wet way .
a. Of arsccions compoands
fi. Of arsenic compounds
Detection of arsenic in cases of
poisoning . . • • , •
Quantitative estimation of srseme.
Atomic weight of arsenic
Separation m>m other dements .
Valuation of arsenic ores

Arsenic, Alloys of

Arsenic, Bromide of • • •

Arsenic, Chloride of . • • •

Ammonio -chloride . • •

Arsenic, Fluoride of . • • •

PAoa
8M

857

859

860
881

863

8''5
867
868

870

871

Apothem :•••::= 'i~!:bSs'v"^df

Apples

Apple-tree

Apple-oil (artificial) .... —

Apyrin (s. Apirin, p. 860).

Apyrite (s. Tourmaline).

Aquafortis . . • -,^ • '

Aquamarine (s. Beryl, p. 681).

Aqua-regla or regis . . . . —

Aquavittt . • •. / • .;
Aquila alba, mitigata, cselestis, mercuni. —

Arabic (gum) —

Arabin . . • • . • • • "

Arachidic acid ^^

Arachidates . • •• • • "~

Arachin "~

Arachis hypogna -"

Arachyl ..••••• ^^*
Aneometer (s. Hydrometer)' ^

Ar8X>xene

Arbol-a-brea redn „• • • . • ^
Amyrin, Breldin, BreSn, BryoTdin . —
Arbor D'ianiB, Martis, Satuml. Ac. . —
Arbutin . . ; • • •
Arcanite (s. Glasente).

Archil • . • ., X •
AroUzite (s. Weraente).
Arctostaphylos Uya Ursi

856

Arsenic, Dihydrido

Arsenic, Trihydride, Arsenetted Hydrogen,

or Arsenamine . . . • "
Arsenic glass, (see Arsenici Sulphides

Arsenic, Iodide of . . • • ""

Arsenic, Liver of (a. Sulphursenitei) . -
Arsenic Ores of Cpp. S60, 870).
Arsenic Oxides of.

Trioxtde, Aisenions oxide or snhy-

dride

Arsenites . . • • •
Pentoxide of Arsenic, Arsenic oxide

or anhydride • • * * £5

Arsenates ^

Arsenic, Oxybromide of . . . «»
Arsenic, Oxychloride of , . . ~"
Arsenic, Oxyiodide of . . • • ""
Arsenic, Oxyaulphide of (see Snlphox-

arsenate of potassium, p. SDo).
Arsenic, Sulphides of:

Disulphide or Hyposdphsrwuous

add ^

Hyposulpharsenites . , , oot
Trisulphide, Arsenious sulphide, or

Snlpharsmious add "

Snlpbarsenites _ •

878
874

THE FIRST VOLUME.

1123

898

899
400

402

403
406

Arsenic : page

Pentatulphide, Arsenic sulfAide, or
Sulpbarseoic acid . . .391
Salpharsenates ... —
Arsenical cobalt, copper, iron, &c. (s.

the several metals).

Arsenical pyrites (s. Iron, Arsenides of:

Arsenical pyropborus. . • . . 896

Arsenic-radicles, Organic . . , —

Arsenides of Allyl . • • • 897

Arsenides of Amyl • • • • —

Arsenides of Kthyl .... —

Arsenethyl —

Arsendietbyl or Eth^l-cacodyl

Arsendiethylic acid .
Arsentriethyl or Trieihylarsine
Araenethylium or Tetrethylarso

nium ....
Arsen-bromethyl-triethyliam
Arsenvinylotrlethylium . . —
Ethylene-hexethvl-diarsonium —
Ethylene-triethyl-arsammonium. —
Aurarsenethyliam and Platarsen-
ethylinm .... —

Arsenides of Methyl ... —
Arsen methyl, or Arsenmonomethyl 40 1
Dicbloride, tetrachloride, chloro-
bromide, iodide, di-iodide, and
oxide of arsenmethyl.
Arsenmethylic acid .
Sulphide of Arsenmethyl
Arsendimethyl, or Cacodyl .
Bromide of Cacodyl .
Chloride, oxychloride, chloro
cnprite, and chloroplatinate
of cacodyl
Chloride of Cacoplatyl
Trichloride of Cacodyl .
Dibromochlride of Cacodyl
Cvanide of Cacodyl .
Fluoride and Iodide of Cacodyl
Oxide of Cacodyl •
Dioxide ....
Caoodylic acid .
Cacodylates
Selenide of caoodvl .
Sulphide of cacodyl .
Disulphide
Sulphocacodvlic acid
Arsentrimethyl and Arsenmethv

llum

Arsendimethyl-diethylium .
Arsen trimethyl-ethylium .
Arsenmethyl-triethylium .
Arsendimethyl-diamylium .
Arsenide of Tetryl •
Arsenide of Trityl .
Arseniosiderite ....
Arsenite, or Arsenolite .
Arsenomelane (s. Dufrenoysite) .
Arsenosiderite . .^ . .
Arsenphyllite . .* . .

Arsidogen

Arthanitin, or Cyclamiu .

Artichoke

Artocarpus incisa ....
Arum esculentum ....
Arum macnlatura ....
Arundo phragmites

Asa dnlcis

AsafcBtida

Asnrin, or Asarone • . . .414
Asarite ......

Asarum-oil . . • • •
Asbestos.— Asbolan . . . .415

40Q

407

408
409

410
411

412

PAGE

Asboline 415

Asclepiadin 416

Asclepione —

Ash of Organic Bodies :

Constituents —

Preparation 417

Analysis 419

Ash, Volcanic 420

Asparagine 421

Asparagolite 422

Asparagus officinalis . . . . ^i—

Asparamide (s. Asparagine) . . . .»

Asparamic acid (s. Aspartic Acid) . —

Aspartic acid —

Active and inactive aspartic acid . 428
Compounds of aspardc add with

other acids —

Aspartates . . ... . 424

Aspasiolite 425

Aspertannic acid —

Asperula odorata . . . .' , .-

Asphalt —

Ashphallene, Petrolene, Asphalt-oil 426

Asphalt, artificial .... 427

Asphodelus —

Aspirator —

Assacou, or Ussaoou .... 428

Assamar -»

Aster tripolium 429

Astracamite —

Astralite -. —

Astrophvllite — •

Atacamite —

Athamanta oreoselinnm . . . 480

Athamantin —

Athanor, or Acanor .......

Athar, or Attar —

Atheriastite —

Atlas ore (s. Malachite) . . . i—

Atlas spar (s. Satin spar) . . * . —
Atmerythrin . ... . .431

Atmidoscope '—

Atmosphere —

Physical properties , . . —

Chemical composition . . . 484
Estimation of Oxygen and Nitrogen

in the air 485

Estimation of Aqueous vapour . 487

Carbonic acid . . —

Ammonia . . 489

Organic matter • •—

Atomic Volume 440

of Gases . . . 441

Elementary bodies in

the liquid and solid state 442

Liquid compounds , 443

Solid compounds . 449

Atomic Weights 450

• Determination of Atomic weights

by chemical considerations . 457

Atomic weight of Carbon . . 459

Nitrogen . . 460

Oxygen . .461

Chlorine . . 468

Table of Atomic weights . • 465

Determination of Atomic weights

by physical considerations . . 466

From the combining volumes

of gases and vapours . . — -
From the specific heats of ele-
mentary atoms . • .470

From isomorphons relations . 472

Atramentnm stone • • • • 478

Atriplox •••••• —

c2 '

1124

INDEX TO

PAOB

Airiplex verracifera . • . . 474

Atropic acid —

Atropine —

Aagite, or Pyroxene .... 476

AugoBtite. — Aurade .... 476

Aarantiin (b. Hesperidin) ... —
Aurarsenethylium (b. Arsenides of

MeUivl, p. 400). — Aurichalcite . . —

Aurotellurite. — Automalite ... —

AuruDi mosaicum or muaiynm . . —

Automolite (a. Gahnite) • . . —

Autanite. — ^Avenin • • . • —

ATentnrin —

Ayentnrin glaas —

Aventurin glaze 477

Avignon, grains of (s. Yellow Berries) . —

Axe-stone —

Axinite —

Azadirine —

Azelaic acid —

Azobenzene —

Azobenzil —

Azobenzoide —

Aaobenzoidine —

Azobenzoilide —

Azobenzoyl —

Hydride of (s. Hydrobenzamide) . —

Azocinnamyl, hydride of (a. Cinnamyl) 479

Azocodeine (s. Codeine) .... —

Azodifune —

Azoerrthrin (s. Orcein\ ... —

Azoleic acid {s. CEnantoylic Acid) . —

Azolithofellic acid (s. Lithofellic Acid) . —

Azolitrain (a. Litmus) .... —

Azomaric acid (s. Pimaric Acid) . . —

Azophenylamine —

Azorite —

Azosulphidd of Benzene (s. BenzoyU

bydride, p. 568) —

Azote (s. Nitrogen) . . • . —

Azotan ....... —

Azotides (a. Nitrides) .... —

Azoxy benzene —

Nitrazoxybenzene .... —

Isonitrazoxybensena ... —

Azoxydifone 480

Azulmic acid —

Azure blue (a. Smalt) .... —
Azure-stone ) (s. Carbonates of Copper,

Asurite J p. 788). ... —

Babinfftonite ....

Bablab, or Neb* neb

Babul-gum, or Gond- babul .

Babylonian quartz

Bagrationite (;&. Orthite)

Baierin or Baierite

Baikalite (s. Diopside) .

Balance

Chemical Balance .
Assay Balance
Adjustment of Beam
Weights ....
Suggestions for care of, in Balance
Mechanical Theory of the Balance
Elimination of Errors .

Ballus, or Balais Ruby .

Ballesteroaite . • • •

Balloon

Balsam . . • • •

480
481

482
488

484
486
487
490
491

493
495
496

497
498
499

500

PAGK

Balsams, Oleo-resinons:

Canada balsam

Copaiba, or Copaira balsam

Mecca bilsam, or Balm of Gllead
Balaams containing rinnamir add
' Liqnidambar .

Peru balsam .

Storax

Tolu balsam .
Balsams, artificial .
Baltimorite .
Bamlite .
Baralite or Baralite
Barbatimao •
Bardiglione .
Baregin or Glairin
Barilla •
Barium .

Barium, Bromide of
Barium, Chloride d
Barium, Cyanide of (s. Cyanides)
Barium, Detection and estimation of:

1. Reactions in the dry way

2. Reactions in the wet way
8. Quantitative estimation'

4. Atomic weight

5. Separation irom other elements
Barium, Fluoride of
Barium, Iodide of .
Barium, Oxides of:

Protoxide: Baryia

Hydrate .

Peroxide
Barium, Oxygen- salts of
Barium, Oxysulphides of
Barium, Phosphide of
Barium, Selenide of
Barium, Sulphides of

ProtosuJphide

Sulphydrate •

Trisulphide .

Pentaaulphide .
Barley (s. Cereals) .
Barnhardtite .
Barocalcite. — ^BaroUta
Barometer

Constniction .

Correction for capacity

Temperature
Capillarity
Index wror

Directions for taking an
of the barometer

Uses of the barometer .
Determination of altitndea
Meteorology

Aneroid barometer

Bourdon's Metallic barometer

Macworth's Underground barometer —
Barras . . .^ . •
Barsowlte ..*...
Barwood or Camwood .
Baryta (s. Barinm, Oxides of, p. 504).
Barytes (s. Heavy Spar) . •
Barytic nuoispar • •

Barytocalcite 518

Baiyto-cceleetin ....
BarytophiUite. — Baryto-etrontianite

Basalt

Basaltic hornblende
Basanite.— Basanomelane

Base 519

Basicerine (s. Hydrocerite)
Basicity . . . •

501

503
503

504

505
506
507

508

508
513

513
514

515
516

517

THE FIRST VOLUME.

1125

PAOB

BMnicnm, ofl of 519

Baatia latifolia ~

Baatic acid —

BaMorin —

Bastard Qorer .....—

Bastite —

Basyl —

BaUtaiedoIis 520

Bath . —

Bath-metal —

Batrachite —

Batracholdc acid —

Baadisserite —

Banlite —

Bavalite (s. Baralite, n. 500)
Bay-salt (a. Sodium, Chloride oQ

Bdelllam 528

Bean ....... —

Beauroontite 524

Bebiricacid 626

Bebirine, or Bebeerine .... —

Beckite 526

Beech . ■ • • > • • ^-

Beech-natoil 527

Beer —

Preparation 528

Analysis 530

Tables showing the Composition of

various kinds of Beer .
Original ^riij of Beer-worts
Adulteration of Beer
Beguin's Volatile spirit
Befiadonna, oil o£ — Belladonnine .
Bell-metal ore ....
Belmontin .....
Belonite (s. needle-ore).

Ben, oil of

Benic acid

Benzaldide (s. Benzoyl, Hydride oO-
Benzamic acid (s. Oxybenzamic acid).

Benzamide

Benzomercuramide .
Benzacetosulphophenamide .
Benzocumylsnlpnophenamide .
Benzoealicylamide . . .
BeniDsulphophenaraide . .
Benzosulphophenaigentamide
Benzosnlphophenylsodamide .
Dibensopnenamide .
Benzamide, Substitution products of:
Broroobenzamide .
Chlorobenzamide • •
Nitrobenzamide

Dinitrobenzamide
Thiobenzamide
Benzamil . . . » .
Benzanilide (sw Phenylamine).
Benzene or Benzol ....
Substitution -products of Benzene :
Bromolwnzene .
Dibromobenzene .
Tribromobenzene • .
Chlorobenzene .
Trichlorobenzene
Chlorodinitrobeozene
Nitrobenzene
Dinitrobenzene
Benzhydramide ....
Benzhydrocyanide (n Benzamide).
Benzhvdrol or Benznydrolic acid .
Benzidam (s. Phenylamine).

Benzidine

Diethylbenzidine .
Tetrethylbenzidine . .

538
534
536
537
538

539

540

541

642
643

54 i

Benzidine ; taqe

Iodide of Dimethyl-tetrethyl-benzi-
dammonium .... 545

Benzil •.—

Benzilam 546

Benzilic acid —

Benzilim —

Benzimic acid . . . . . 547

Benzimide —

Benzin (s. Benzene).

Benzoacetic anhydride (s. Acetic anhy-
dride, p. 21).

Benzo-angelic anhydride (s. Angelic An-
hydride, p. 293).

Benzocarbolic add (s. Benzoate of Phe-
nyl, p. 563).

Benzocnlorhydrin —

Benzodnnamic anhydride (s. Benzoic
anhydride, p. 567 >

Benzocuminic anhydride (s. Benzoic an-
hydride, p. 293).

Benzocumylsulphophenamide (s. Benza-
mide, p. 539^.

Benzoen (s. Benzyl, Hydride of, p. 573).

Benzoeretic add •»

Benzoglvcollic add

Benzoneiicin

Benzoic acid :

History, sources, formation, pre-
paration . . .
Properties, decompodtions
Benzoates (metallic)
Benzoic ethers
Benzoate of Methyl
Ethyl .
Ethylene
Amyl .
AUyl .
Benzyl .
Glycyl ,
Phenyl
Bromophenyl
Chlorophenyl
Dinitrophenyl
Trinitrophenyl
Benzoic add. Substitution-products of:
Bromobenzoic acid . •
Chlorobenzoic add .

Parachlorobenzdc add
Kitrobenzoic add
Mitrobenzoates (metallic)
Nitrobenzoic ethers

Kitrobenzoate of Methyl
Ethyl
Dibromophenrl —

548
549

560
551
652

568

564

555

556

i^ioromopnenri —
Diniirophenyl —

545

Dinitrobenzoic add . . . 657
Nitrochlorobenzoic add . . — .
Benzoic Alcohol (s. Benzylic Alcohol.

p. 579).
Benzoic anhydride ....,—.
Beiizo-scetic, -dnnamic, -cominic,
-myristic,-<Bnanthylic,-peIargonic,
-stearic, and -valeric anhydrides . 558
Benzonitrobenzoic snhydriue . . —
Nitrobenzoic anhydride .....

Benzoicins —

Benzoin 659

Acetyl-benzoin . . . . _

Benzoyl -benzoin .... 560

Nitrobenzoyl-benzoin . . . -.

Benzoinam .«..•• —

Benzotnamide —

Benzoin-gum —

Benzolactic add 561

1126

INDEX TO

FAOB

Benzolic Alcohol (s. Bensylene).
Benzoline (s. Amarine, p. 162).
Benzoline . . . . • 662

Benzomercuramide (p. 689\
Benzomyrifltic anhydride Qp. 558)
Benzono . . • • •
Dinitrobenzone

Benzonitrile 563

Chlorobenzonitrile .... 664
Nitrobenzonitrile .
Benzonitrobeiizoic anhydride (p. 558).
Benzonitrocumide (s. Cumylamine).
Benzcenanthic anhydride (p. 558).
Benzopelargonic anhydride (p. 568).
Benzophenide (a. Benzoate of Phenyl,

p. 553).
Benzopbenone (s. Benzone, p. 562).
Benzopiperide (s. Piperidine).
Benzoprup^lenyl (a. Benzoate of Allyl,p. 552).
Benzoaalicm (a. Populin).
Bensoaalicylamic acid .... —
Benzosalicylamide • . • . 566

Benzosalicylic acid .... —
Benzosalicylimide (b. Benzamide, p. 589).
Benzostearic anhydride (p. 558).

Benzostilbin •—

Benzosnccinin —

Benzosulphophenamic acid (a. Beozamic

acid, p. 5d8\
Benzosulphophenamide (a. Benzamide, p.

540).
Benzoaulphophenamidyl, Chloride and

Amide Ta. Benzamide, p. 540).
Benzosalpbophenylaodamide (p. 540).
Benzosylanilide (a. Benzylene-phenyl-

amine, 677).

Benzotartaric acid ~-

Benzovaleric anhydride (p. 558)
Benzoyl .....
Benzoyl, Bromide of

Benzo}'], Chloride of
Chloride of Chk
Chloride of Nitr

Benzoyl, Cvanido of

71
Chloride of Chlorobenzorl
Chloride of Nitrobenzoyf

566

567
568

Benzoyl, Hydride of: Benzaldine ; Sitter
Almond Oil, . . . . . —
Benzoate of Hydride of Benzoyl . 569
Hydride with Chloride of Benzoyl . —
Hydrocy anate of Hydride of Benzoyl 570
Hydride of Benzoyl with Chloride

of Calcium —

Hydride of Benzoyl with acid Sul-

phitea of Alkali metals . . —

Substitution-products :

Hydride of Nitrobenzoyl . . —

Thiobenzoyl . .571

Thionitrobenzoyl . 572

Oxyiodide of Hydride of Benzoyl —

Benzoyl, fodide of —

Benzoyl, Perchloride of (p. 666).
Benzoyl, Sulphide of • . . . —
Benzoyl, Sulphocyanide of (s. Snlphocy-
anobenzylene).

Benzoylazotide —

Benzoyl-benzoin (s. Benzoin, p. 659).
Benzoyl-urea (s. Carbamide, p. 763).

Benzoylureid 573

Benzureid (s. Benzoyl-urea).

Benzyl : Tolyl, Toluenyl ... —

Benzyl, Chloride of ... . —

Benzyl, Cyanide of —

Benzyl, Hydride of.
H

ydride of Nitrobenzyl .
Dinitrobenzyl

674
675

Benzyl, Iodide of . «
Benzylamine: Toimdine

Cyanobenzvlamine : .

Melobenzylaroine : Mt

Benzethylamine

Benzyldiethylamine

Benzyltriethylium .

Nitrobensylamine .

Tribenzylamine .
Benzylene

Benzylene, Chloride of .
Benzylene, Sulphide of .
Benzylene-phenylamine
Benzylenic ethers .

Methyl-benzylenic ether

Cvanatolu
laotohddii

kABme 676

^ohadime

PAGE

676

577

678

Ethyl- and Amyl-benzylenic ethers
Aoeto-, Benzo-, Succino-, Sulpho-,

and Yalero-benzylenic ethers . —
Benzylethylamine (p. 676).

Benzylic Alcohol — .

Benzylic Ether 579

Ethyl-boiZrylic ether ... —

Berannite —

Berberine • —

Berengelite 689

Beresite —

Bergamot, Oil of —

Bergamot-campfaor; Bergaptene. 681

Berthierin —

Berthierite or Haidingerite ... —

Bertholletia exoelsa .... —

Beryl —

Ber3*nium (s. dndnam).

Betzelianito 682

Berzeliite .... . —

Berzelin —

Berzelite —

Beta .... . • —

Betnlin .... . . 68S

Betuloretic acid . . . , —

Beudantin (s. KepheUn).

Beudantite ... . . —

Bezetta —

Bezoar 684

Bezoardic acid (s. Ellagic add).

Bezoardicum animale . . . * . —

minerale .... —
Bi-compounda (s. Di-comnounds).
Bildstein (s. Agalmatolite).
Bile .......—

Analysis 685

Pettenkofer's test .... 586
Composition of Bile of yarioos

animals .—

Putrefaction of Bile ... 687

Bilianr Calculi .... 688
Bimstein (s. Pumice-stone).

Binary Theory of Salts .... —

Binnite . —

Biotin (s. Anorthite, p. 808).
Biotite (s. Mica).

Birch —

Birch AinguSyjttioe, oil, resin, and tar 689

Birdlime —

Bismuth 690

Bismuth, Acicular . . . .691

Bismuth, Alloys of —

Bismuth, Bromide of —

Bismuth, Chlorides of:

Trichloride ..... —

Dichloride . . . . .«

Bismuth Cnpreoas 592

Bismuth, Detection and Estimation of:

Blowpipe reactions ....»-

THE FIRST VOLUME.

1127

FAOB

Biflmnth, Detection and estimation of:

Liquid reactions .... 592

Quantitative estimation ... —

Atomic weight . . . . —

Separation n-om other elements . 593

Yaloation of Bismath ores . . —

Bismatby Fluoride of ... . 694

Bismuth, Iodide of. • • . . —

Bismuth, Oxides of ... . —

Trioxide, or Bismuthous oxide . —

Pentoxide, or Bismuthic oxide . —

Bismntbates .... 695

Bismath, Oxychloride of (p. 591).

Bismuth, Oxygen-salts of . . . —

Bismuth, Phosphide of ... —

Bismuth, Selenide of . . . . —

Bismuth, Sulphides of . . . . —

Bismuth, Sulphochloride of . . . —

Bismuth, Telluric (s. Telloriam).

Bismuth, Teliuride of . . • . —

Bismuth-glance^ or Bismuthine . . —

Bismuth-nickel 596

Bismuth-oehre . . . . . —

Bismuth-radicleSi Organio ... —

Bisethyl —

Bistriethy], or Triethyl-bismuthine -*

Bismuth-silver 597

Bismutite —

Bissa-bol • • . . . . —

Bistre —

Bittep-almond oil —

Bitter-almond water .... 699

Bitter principle —

Bittern . • —

Bitterspar, or Bhombspar ... —

Bittersweet 600

Bitumen —

Biuret —

Bixin .••«.. . —

Black Band 601

Black Chalk —

Black Jack —

Black Lead (s. Carbon, p. 758).

Black Wadd —

Blanchinine —

Blanquette . • - . . . • —

Blaps obtusa — *

Bleaching 602

Bleadiing Powder (s. Hypochlorites).

Bleinierite —

Blende .....«• —

BMJdite —

Blood —

Its analysis 610

Blood -stone (s. Jasper) . . . .612

Blowpipe • —

Blowpipe analysis . . • . 618
Table of behaviour of Metallic
Oxides, with Microcosmic salt

and Borax 614

Table Blowpipe . • . .616

Oxyhydrogen Blowpipe . . —
Blue, Prussian Qs. Cyanides of Iron).

Bine, Saxon 617

Bodenite —

Bog-butter —

Bog-head Coal (s. Coal). ... —
Bog -ores (s. Iron).

Boheic acid ...••• —
Boiling Point (s. Heat).

Bole . —

Bolognian Stone —

]}oieticacid 618

Boletus —

619

623

624
625

626

627
629

Boloretin . . •
Boltonite.— Bolus .
Bone ....
Diseased bones
Fossil bones .
Bone-black .
Bone-oil.— Bonsdorffite .
Boracic acid (s. Boric acid, p. 686)
Boracite ....
Borax (s. Borate of Sodium, p, 645).
Borides (s. Boron, d. 629).
Bomeene. — Bomeol . .
Bomite.— Borocalcite .
Boron ....
Boron, Bromide of .
Boron, Chloride of . .
Ammonio-chloride .
Boron, Chlorocyanide of (s. pyanogen.

Chloride of).
Boron, Detection and Estimation of:
Reactions ....
Quantitative estimation
Separation from other elements
Atomic weight
Boron, Fluoride of •

Fluoboric acid
Hydrofluoboric acid
Borofluorides . •

Boron, Iodide of .
Boron, Nitride of .
Boron, Oxide of: Boric anhydride
Boric acid
B6rates .

Borates of Aluminium
Ammonium
Barium .
Cadmium
Calcium
Cobalt •
Copper .
Iron
Lead
Borochloride of Lead
Boronitrate of Lead
Borate of Lithium .
Borates of Magnesium
Borate of Nickel .
Borates of Potassium

Silver . • . .645
Sodium .
Strontium ... 649
Zinc .
Boric Ethers: Borates of Amyl

Ethyl 650

MeUiyl —

Boron, Sulphide of .... 651

Boronatrocsldte —

Botryogen ...••• -^
Botryoute ...... —

Boulangerite.— BonmonitA . . . —

BoveyCoal —

Bowenite (s. Serpentine).
Boyle's fuming Liquor (s. Sulphides of
Ammonium, p. 194).

Bragite —

Brain (s. Nervous Tissue).

Bran 652

Branchite —

Brandisite (s. Clintonite).

Brandy . . • • • • • -*

Brass 668

Brassica —

1. Brojftea oforoeea : Cabbage . . — >
Composition of Cabbage-leavei —

680

681
632

688

685

686
639
641

642

648

644

1128

INDEX TO

BnMic*: paob
Ash of different ririeties of

Cabbage 664

8. Braasica jVapus : Rape . . . —

Aflh of Seed and Straw . . —

8. Sroasica Rapa: Turnip . —

GoropoBition of Ash . • . 656

Braasic acid —

Brayera antnelmlntica . . . . —

Braril wood —

Bread 666

Fermented 667

Unfermented 660

Aerated bread .... —
Brean (a. Icica-resin).

Brein and Breidin (s. Arbol-a-brea, p. 846) 662

Breialakite. — Breithaaptite . • • —

Bremer Green 663

Brennerite (a. Maffneaite).
Brevicite (a. Natrolite).

Brewsterite -~

Brewatolin —

Bricka —

floating 664

BrOUant ~

Brimstone (s. Salphnr).

Brindonia indica .....—

Britannia metal . . . ^ . ->

Brithvne (& Glauberite).

British gam (s. Dextrin).

Brittle Sil?er-ore.—Brocatello . . —
Broccoli (s. Braasica).

Brochantite —

Broddbo TanUlite (a. Tantalite).

Bmgniardite —

Brogniartin, or Brogniartite '(s. Glau-
berite).

Bromaoetic acid —

Bromacetates 665

Dibromacetic acid .... 666
Bromacetins (s. Acetins, p. 26).

Bromal , —

Bromaloln (s. Aloln, p. 148).
Bromamide (s. Nitrogen, Bromide of).
Bromanil (s. Qoinone).
Bromanilamic acid (b. Qninonlc acid\
Bromaniloide (s. Tribromophenjla-

mine, under rhenylamine).
Bromanisic acid (p. 801).
Bromanisol (p. 805).

Bromargyrite. — ^Bromein . . . 667
Brometheride Ts. Yinyl, Bromide of)-

Biomethionesal —

Bromhydric acid (p. 672).

Bromhydrins —

Mono-, Di-, and Tribromhydrin . 668

Epibromhydrin .... —

Hezaglyceric Bromhydrin . 669

Hemibromhydrin .... —

Bromic acid —

Bromic Silver 672

Bromides 672

Bromide of Hydrogen: Bromhydric

or Hydrobromic add . . . —
Bromides, Metallic . . . .674

Bromides of Organic radicles • . —

Bromindaraite 676

Bromindoptene —

Bromine —

Bromine, Chloride of ... . 676
Bromine, Detection and Estimation of:

1. Reactions 677

2. Quantitative estimation —

680

FAGS

Bromine, DeiectioD and estimatioo of:
Estimation in prmnca of Chlo-
rine and Iodine . . . 678
8. Atomic weight .... 679
Bromine, Fluoride of
Bromine, Oxygen-adds of
Bromine, Sdenide of
Bromine, Sulphide of .
Bromiodoform . •
Bromisatic add (a. Isaticadd).
Bromisatin (a. Isistin).

Bromite ^

Bromitonic add (a. Oitnoooie add. De-
compositions of, p. 998).
Bromhte (s. Alstonite, p. 149).
Bromoibrm. — Bromoplcrin . . . —
Bromosamide (s. SalicyUunide).
Bromotrioonicadd) . r«i#,A» -^j « ooc\
Bromoxafbrm J ^*' ^"™^ *=^ P- '*>■
Bromus. — ^Bromyrile • • . . —

Bronae —

Bronzite ....•• —

Brookite 681

Brossite —

Bronasonnettia tinctoria ... —

Brown berries —

Brudne —

Salts of Bmdne • . • • 682
Bromo-bmdne .... 683
Ethyl-bmcine ...•--

Bmdte 684

Bmnolic add —

Brunswick green ...•• —
Bryoldin ......—>

Bryonin —

Bryoretin

Bubnlin

Bucholsite

Bucklandite (a. EpidoteS.

Buckthorn (a. Bhamnns).

Buckwheat

Colouring matters of Buckwheat
Bucnrumanga resin
Buenin. — ^Buhrstone
Bukku leaves
Buratite

Burette (p. 256).
Burgundy Pitch or
Bursera gnmmifera
Bustamite (s. Rhodonite).
Buteagum .
Butic add

Butter ....
Batter of Antimony, Tin, &c.
Butyl (s. Tetryl).
Butylactic add
Bntyracetic add • • •
Butyral

Chlorobutyrals
Butyraldehyde

Butynudehyde-ammonia
Butyramide ....

Mercoric batyramlde
Bntyric acid ....

Butyrates
Butyric add. Substitution-derivatives of

Dibromobutyric add

Dichlorobntyric add

Tetrachlorobutvric add

Thiobutyrie acid .
Bntyric anhydride •
Btt^jrric ethers

Bntyrate of Allyl .
Amyl

686

687

688

689

690

691
692
698

694

696

THE FIRST VOLUME.

1129

PAGE

Bat jric ethen :

Bntyrate of Ethyl . • . . —

Ethylene ... 696

Glyceryl ... —

Methyl ... —

Batyndin —

Botyrins :

Mono- and Dibutyrin • . —

Tribntyrin 697

Natural bntyrin • . • . —

Botyrite —

Batyrochlorhydrin • . • ' —

Bntyrolelc aad —

Bntyrolironodic add (& Bog-batter, p. 617).

Batyrolactie add —

Batyrone —

Batyronitric add .... 698

Batyronitrile —

Batyram antimonii . • . . —
Batynirdd (s. Bntyryl area)

Batyryl —

BromidOi Chloride .... —

Iodide 699

Bntyryl-orea (a^ Carbamide, p. 758).

Baxine ...... —

Byssolite —

Byssiia Mytili —

Bytownite —

700

701

702

703

705

Cabbage

Cabbagiine

Cabocle

Cacao

Cacao-fat ....

Cacao-red . ... •
Cachalagna.— Cachdong
Cachoutannic add (i. Catecho, p. 817).
Cacotheline . • . • •

Cacoxene

Cactus ....••
Cadet's Faming Liqaor (p. 408).
Cadie gam . • . . •

Cadmium

Cadmium, Alloys of . . •
Cadmium, Bromide of . * . * —
Cadmium, Chloride of . . . • —

Double salts of Chloride of Cadmium —
Cadmium : Detection and Estimation of 704

1. Blowpipe reactions

2. Liquid reactions
8. Quantitative estimation .

4. Separation from other dements

5. Atomic weight •
Cadminnit Fluoride of . . .
Cadmium, Iodide of . • •
Cadmium, Nitride of • • •
Cadmium, Oxides of . . •
Cadmium, Phosphide of •
Cadmium, Sulphide of . •
Cadmium-ethyl • . • .

Cesium .'

Caffeic acid (s. Gaffetaanio add, p. 709).
Caflfeine or Theine . • . •

Salts of Cafidne

Caflfeone

Caffetannic acid . . • t

Calncic add

Caimgoi m stone (s. Quarts).
Cajepnt, oil of • • • •
Gi^putene

Isoc^jputene • • • •

Paracaiputene • • •

Bromide of Cajputene .

706

707

709

710

711

FAOB

Cajputene:

Chloride of Cajputene . . .711
Hydrates of Cajputene . . .712

Hydrochlorates of Cajputene . . 718

Hydriodate of Cajputene . . —
Calaite (s. Turquois).

Calamine —

Calamine, Siliceous .... 714

Calamite —

Calcareous spar (s. Calcspar).

Calcedony (s. Chalcedony).

Calchantum ...•..—

Calcination^— Caldte .... —

Calcium • —

Calcium, Bromide of . . . .716

Caldum, Chloride of ... . —

Caldum, Detection and Estimation of . 716

1. Reactions in the dry way . . — -

2. Reactions in the wet way . . —
8. Quantitative estimation . . 717
4. Separation from other elements . —
6. Atomic wdght ....-—

Caldum, Fluoride of . . . .718

Calcium, Oxide of —

Calcium, Oxychloride of (p. 716).
Calcium, Oxygen-salts of . . .719

Calcium, Oxysulphide of . . . —

Caldum, Phosphide of . . • . —

Calcium, Selenides of ... . 720

Calcium, Sulphides of • • . . —

Calc-sinter . . • . - . . —

Calcoferrite —

Calcspar 721

Calctuff 722

Calculus —

Calderite —

Caledonite .••... —

Calendulin —

Calico-printing —

Caliibmin —

Calisaya bark.— Callais . . • • —

Calluna vulgaris —

Callutannic add 728

Calluxanthin —

Calomel (s. Mercury).

Calophyllum redn — -

Calorimeter —

Calorimotor —

Calstronbar>'te —

Calyptolite —

Camboley resin —

Camellia japonica —

Campeachv wood (s. Logwood).
Camphamic acid, and Camphamide

(p. 729).

Camphene ...... 724

Camphenes —

Campherenes 725

Campheryl or Campherfle .^ . . —

Camphic add ....*.. —

Camphides ' *^ —

Camphilene .••...—
Camphimide (p. 782).

Camphin —

Camphine 726

Camphocreoflote —

Camphol —

Campholene ...... —

Campholicadd • • . . . —

Camphone 727

Camphomethylic add (p. 788).

Camphor —

Dextro- camphor • • • • —

L«vo-camphor • • • • 729

1130

INDEX TO

Ctmphor:

Inactive camphor • • . •
Camphor, artificial (a. Turpentine).
Camphor of Borneo (a. Borneol, p. 626).

Camphor, oil of

Camphoramic acid . . . .
Camphoranilic acid (i. Phenyl- campho-
ramic acid).
Camphoresin . - . • . .

Camphoric add :

l>extro>camphoric add •

X««vo-camph<Hrie add •

Inactive camphoric add

Camphoratea .
Camphoric anhydride .
Camphoric ethers :

Camphorate of Ethyl •

Camphorateof Ethvl and Hydroeen

Camphorate of Methyl and Hy-
drogen • • • ■ •

Camphorimide

Camphorin

Camphorone .••••.

Camphoryl

Camphosulphoric add (s. Snlphocam-

pboric add).
Camphovinie add (b. Campnoric ethers^
p. 732).

Camphrene •

Camphrone

Camwood (a. Barwood, p. (17).

Canaanite . ...

Canada balsam (s. Balsams^ p. 492).

Cancerin

Cancha-lagna (a. Cachalagoa, p. 701).
Cancrinite.— Candite . . . •

Canella alba

Cannabis indica

Cannabis sativa

Cannamine (s. Bracine^ p. 681).

Cannel coal Ql Coal).

Cannon metal (a. Copper, Alloys of).

Cantharides

Canthariditt

Cantonite

Canton*s phoaphoms . • • •

Caontchene

Caoutchin

Hydrodilorateof caontchin .
Caootchouc

Yalcanised caontchonc .

Hardened caoutchooc ; Ebonite •
Caontchoncin (p. 789).
Capers (s. Capparis).
Caphopicrite (s. Rhein).
Capillarity ••..••

Capnomor

Capordanite

Capparis spinosa

Capral

Capramide

Capric add

Capric aldehyde . . . • •
Caprinamide (a. Capramide).
Caprodanite (a. Capordanite).

Caproene

Caproic add

Capruic alcohol (s. Hexylic Alcohol).

Caproic aldehyde

Caproic anhydride . . . . •

Caproic ethers

Caprone

Capronitrile

Capronoyl

FAQB

729

780

781

782
783

784

786

787
788
789
740

741

742

748

PAGE

. 744

744

Caproyl • • • • •
Caproylamine (a. Hexylamlne).
Caprovlene (a Uezyiene).

Capiyl, or Rutyl 745

Caprylamine (a. Octylamine).
Capfylene (s. Octylene).

Caprrlie add —

Nitrocaprylic add • . . . —
Capn'lic alcohol (a Octylic Algohol).

Caprylic aldehvde —

Caprylic anhydride «... 746

Caprylic ethers —

Caprylone 747

Caprylvl —

CapseUa —

Capsidne . • • . . . —

Caput mortnam —

Caragheen moss —

Carajum, Cnuom, or Carciini . , ^

Caramel —

Caiamelanep Caramelene^ Caramelin 748

Caranna 749

Carapa bark —

Carapaoii —

Carat —

Carbamicadd. —

Carbamates of Ammoninmy Amy],

and Ethyl 750

Carbamates of Methyl and Tetryl . 751
Etbyl-carbamic add ... —
Ethyl-carbamate of Ethyl, or
EthyUnrethane ......

Phenyl* carbamic acid . . . —
Phenyl-carbamates of Ethyl and
Methyl • ... 752

Carbamide —

Substitution-prodocts of Carbamide :

QxiuioMiMi c7reaa:
«, Carbamides or Ureas containing
AddRadides:
Aoetyl-carbamide . . . 758
Bensoyl-carbamida • • . —
Bntyryl-carbamide ... —

Yalciyl-caibamide ...

fi, Carbamides or Ureas ft^nfiyftg
BasyloQs Radides:
Allyl-carbamide . . . 754
AUyl-snlphocaibaaaida
Diallyl-carbamide .
Amyl-carbamide •

BenayUcarbamide
Ethyl- carbamide
Diethyl-oarbamide .
Ethyl-allyl-carbamide .
Ethyl-allyl-enlphoearbaaiide
Ethyl-amyl-carbunide •
Hethyl-oarbamide
Dimethyl-carbamide
Methyl-ethyl-carbamide
l^aphthyl-carbamide .

Naphthyl-allyl-carbamida . 755

Phenyl-carbamide

Ethyl-phenTl-eaihamide

Nitrophenyl-carbaaaida • . 756

Diphenyl- carbamide

Phenyl- suphocarbamide

Phenyl-allyl-salphocarbamide

Diphenyl"

PiDefyl-catbam'ide • . 757

Methyl-piperyUoarbamide

Caibanil (a Cyaaic Elhen).

Carbani]ide(a Diphenyl-<atftiamide^'pi756).

Carbanilic add (a '^'^ — ' "^ — - — ''

P 751).

THE FIRST VOLUME.

1131

PAOB

Carbanilethane and Caibanimethjlane
(p. 752).

Carbasote 757

Garbazotic acid (s. Picric acid).

Curbides, or Carburets .... —

Carbobeoaide (a. Benione).

Carbobenzoic acid (s. Ginnamein).

Carbo-hydrogena (& Hydrocarbona).

Carbolic add (a. Phenie acid).

CarboD ~-

1. Diamond —

2. Graphite 758

8. Anthracite 759

4. Carbon obtained from organic

subatancea by dry distillation

or imperfect combuation :

a. Wood-charcoal ... —

6. Coke 760

c. Metallic carbon, Glanoe-eoal . —

d. Lamp-black .... —
a. Animal charcoal . • .761

Absorbent power of charcoal . . —
Platinised charcoal . . .762
Charcoal aa a precipitant and deo-

doriaer —

Compounds of carbon . . . 768

Carbon, Bromidea of • • • . 764

Carbon, Chloridea of ... . —

Tetrachloride 765

Trichloride 766

Bichloride 767

Protochloride 768

Carl>on, Ghlorobromide of . • . —

Carbon, Detection and Eatimation of • —

Atomic weight of Carbon . . 769

Carbon, Iodide of 770

Carbon, Nitride cf —

Carbon, Ozidea of —

Dioxide or Carbonic anoydride . 771

Liquid Carbonic anhyaride . —

Solid Carbonic anhydride . . 772

Carbonic acid .... —

Protoxide or Carbonic oxide . . 778

Carbon, Oxychloride of: Phoagene . 774

Carbon, Sulphides of:

Diaulphide ..... 775

Protoanlphide 777

Carbon, Sulpnochloride of . . . —

Carbonates .... . 778

Carbonste of Alumininm • . 779

Carbonates of Ammonium . —

Carbonatea of Barium, Bismuth,

Cadmium, Calcium . . . 780
Carbonates of Cerium, Chrominm,

Cobalt .... .782

Carbonates of Copper . . 788
Carbonates of Didyminm and Gln-

cinum 784

Carbonates of Iron:

Ferric Carbonate . • . . ^

Ferrous Carbonates . . . 786

Carbonate of Lanthanum . . —

Carbonates at Lead .... 786
Carbonate of Lithium . . .787

Carbonates of Magnesium . . —
Carbonates of Manganese, MerciHy,

Nickel 789

Carbonate of Palladium ... 790
Carbonates of Potassium :

Dipotaasic or Neutral carbonate . —
Mono-potassic or Di-add carbo-

nate 791

Sesquicarbonate .... 792

Carbonate of Silver • . —

PAOB

792
796
796

797

798
793

800

801

802

Carbonates:

Carbonates of Sodium ;
Diaodic or Neutral carbonate
Monosodic or Di-acid carbonate
Tetrasodic or Seaquicarbonate

Carbonate of Sodium and Potaaaium

Carbonate of Sodium and Galdnm

Carbonates of Strontium, Thorium
Uranium ....

Carbonate of Yttrium . .

Carbonates of Zinc . . .

Carbonate of Zirconium
Carbonic acid and anhydride (p. 770).
Carbonic ethers ....

Carbonate of Allyl . .

Carbonate of Amyl

Carbonate of Ethyl
Tetrachlorocarbonie ether .
Perchlorocarbonic ether
Carbonate of Ethyl and Potassium

Carbonate of Methyl and Barium

Carbonate of Methyl and Ethyl

Carbonate of Phenyl and Hydrogen

CarbonaU of Tetryl (or Butyl)
Carbonitrotolnylic add .
Carbonyl
Carbopyrolic acid
Carboatyril .
Garbothiacetonine
Garbothialdine
Carbotriamine

Carbomethyltriamine

Carbotriethyltriamine

Carbophenyltriamlne

Carbotriphenyltriamine
CarboTinic add (a. Carbonic ethers, p. 801).
Carboyinomethylide (ayn. with Carbo-
nate of Ethyl and Methyl, p. 801).

Carbuncle

Garbnrdo add (ayn. with AUophanic

acid, p. 182).
Carbyl, Sulphate of (ayn. with Ethionic

anhydride).
Gardamine aroara .
Cardamom oil
Cardol . . ,
Carex

Garica papaya
Gariea (a. Bone, p. 628).
Garinthin . .
Garmidine
Carroinaphtha .
Garmindin

Carmine, Carminic add
Carminite, Carmine apar
Carmufellio add .
Gamallite. — Caroat
Gamauba wax
Camelian .
Garoluthin
Carotin .
Garpholite
Garphodderite
(^rphostilbite
Garpobalsamnm
Garrolite

Carrsgheen moss (s. Caragheen moas,
p. 747).

Carrot <i—

Carrot, oil of —

Carthamin 808

Cartilage .••,.,—
CarTone, Carrol, and Canracrol . • —
Garyophyllic add (s. Eugenic acid).

803

804

806

806
807

1132

I5DEX TO

PAGBl

Ourfophyllin . .... 809

Ciscalho . • . . . —

CiUKarilla bark . • . . —

Cascarilla, oil of —

Cwcarillin —

Case-hardening —

Casein .810

Casein, vegetable (s. L«gumin).

Cassava 818

Cassell yellow (a. Lead, Oxjchloride of).

Cassia caryopbjllata . • . . —

Cassia dnnamonea .... —

Cassia fistula —

Cassia buds —

Cassun 814

Cassiterite ......—

Cassiterotantalite . . . . . —

Cassius, Purple of —

Castelnaudite .••... —

Castilloja elastica —

Castine —

Castor . . ' • . . * . —

Castoreom —

Castorin 815

Castor oil —

Catolysis —

Catapleiite —

CaUwbarite 816

Catechu —

Catechine ; Catechodc acid . . —

Catechu-tamiic add. . . . 817

Catha edulis ....*. —

Cathartin ...... —

Cathode, or Kathode .... —

Catlinite 818

Cat's eye —

Caulopbyllin —

Caustidty —

Cavolinite (s. EUeolite and Nephelin).

Cawk —

Cedar, Oil of —

Cedrene —

Cedrin (s. Cedron).

Cedriret —

Cedron —

Celestin (s. Coelestin^.
Cellulic add (s. Pectic acid).

Cellulose —

Solution of Cdlolose . . .820

Celtis —

Cement —

CemenUtion 822

Cement Copper ...,.->
Centaurin (s. Cnidn).
Cephalis (s. Ipecacuanha).

Ceradia fuscata —

Ceraicacid .••... —

Cerain —

Cerancephalote (s. Cephalote).

Cerantic acid —

Cerasin 823

Cerasus —

Cerate —

Ceraunite (s. Nephrite).

Cerealin —

Cereals —

Cerebric add ..... . 829

Cerebrin —

Cerebrol . 830

Cerebro- spinal fluid .... —

Cerebrate ......—>

Ceric add ...... —

Cerin . . . . . . . —

Cerine (s. Orthite).

Cerinin .

Cerite .

Cerium .

Cerium, Bromide of

Cerium, Chlorides of

Cerium, Detection and EsUmatioa of

1. Beactions

2. Quantitative ertimation
8. Separation from other dementa
4. Atomic weight

Cerium, Fluorides «
Cerium, Oxides of .

Ceroiis oxide .

Ceroso-ceric oxide

Ceric oxide
Cerium, Oxygen-salts of
Cerium, Phosphide of
Cerium, Sdenidd of
Cerium, Sulphides of
Cerolein .

Cerolite, or Kerolite
Ceropic acid •
Ceroeic add • •
Cerosin • •
Cerotene
Cerotic add .

Chlorocerotic add
Cerotic ethers :

Cerotate of ethyl .

Cerotateof cervl; Chinese
Carotin (p. 838).

Cerotinone .....
Ceroxylln: Palm-wax .
Cerumen of the ear
Ceruse (s. Carbonates of lead, p. 786).
CerudU (p. 786).

Cervantite

Cer^l, Hydrate of: CujHe akokof, Cero'

Cetene, or Cetylene • • . .

Cetic add

CeUn

Cetraria (s. Lichens).

Cetraric add

Cetyl

Cetyl, Acetate, Benzoate, Bromide, Bntj-

rate. Chloride, and Cl}'anide of .
Cetyl, Hydrate of : CetgHc AkoM;

Eihal

Cetyl, Iodide of

Cetyl, Nitride of (s. Cetylamine).
Cetyl, Oxide of : CetvUeeAer

Getyl-ethyl-oxide . . . .

Cetyl-sodium oxide.

Cetyl, Stearate of

Cetyl, Sucdnate of ... .
Cetyl, Sulphate (add) of: Cet^'n^AMrie

acid

Cetyl, Sulphide of

Cetyl, Sulphydrate: OtfyKe Man^pian .
Ceiylamines :

Tricetylamlne

Cetyl-pbenylamine . •

Cetyl-xanthic add

Ce\nuiic add

Cevadin: Hordem

Ceylanite, or Ceylonite . . . .

Chabasite

Chsroph^Ium . . . . •
Chailletia toxicaria. . . . •

Chalcanthite

Chalcedony ......

Chalcodite ......

Chalcolite (s. Uranita).

PAGB
881

832
833

834

885

836

837

838

839
840

841
842

843

844

THE FIEST VOLUME.

1133

PAGE

Chalcophacite 845

Chalcophjllite (s. Copper mica).
Chalcopyrite (a. Copper pTrites).

Chalcofltibite —

Chalcotrichite —

Chalilito —

Chalk —

Chalk stones.— Chalkostn . . . ^

Chalybeate waters. — Chalybite . . —

Chamflsleon mineral .... —

Chamsrops hnmilif • • . . —

Charooisite —

Chamotte ...... —

Champagne wine —

Chantonite 846

CharafoBtida —

Charcoal (s. Carbon, p. 759).

Chathamite —

Chavica oflScinamm .... —

Chay, or Chaya root • • . . —

Cheese . • • ■ • . —

Cheiranthns Cheiri 847

Chelerythrin —

Chelidonic add —

Chelidonine 849

Chelidoninic acid 850

Chelidoxanthin . . , . . —

Chemical affinity —

Distinctions between Chemical Com*

rounds, properly so called, and

Mixtares or Solutions t

1. As regards proportwn: Law

OF MULTIFIJCS . . .851

2. As to the eharaeter of the pro-
duet —

8. As to th^ ohenomena which
accompany tne formation and
decomposition of chemical com-

pounds 852

Different orders of chemical com-
pounds —

Formation and decomposition of

chemical compounds . . 858
Formation of compounds by di-
rect union of elements . . 854
Formation of compounds by trans-
formation of previouslyezisting
compounds :
I. By Heat . . . .855
n. By Electricity . . . ^
HI. By the action of another
substance, simple or com-
pound : Substitution
AND Double Dkcomfo-
8ITI0N .... —
Magnitude or strength of affinity . 858
Circumstances which modify the
strength of affinity :

1. Elasticity and Cohesion . 859

2. The relative quantities of
the acting substances

Berthollet's law
Bunsen'slaw .... 8C0
Debus*s experiments . .861
Gladstone's experiments
Halaguti's experiments . . 863
Margueritt^s experiments
H. Hose's experiments .
Theories of chemical action . . 864

Chenocholalic acid .... 867

Chenocholic acid •

Chenocoprolite

Chenopodium.

Chert ..••••• 868

PAOB

Che8S}'1ite (s. Carbonates of Copper, p. 784).
Chesterlite (s. Felspar).

Chestnut 868

Chiastolite ...... ^

Chica 869

Childrenite — .

Chilelte (s. Gttthite).
CbUtonite (s. Prehnite).

Chinoline —

Salts of chinoline .... 871

MethyUchinoline .... 872

Ethyl-chinoline • . • . —

Amyl-chinoline .... 878

Chinone.— Chiolit« .... —

Chitin 874

Chiviatile 875

Chladnite (s. Meteorites).

Chloanthite. —

Chlocarbethamide (^n. with Trichlo-

racetamide, p. 6^.
Chlorocetamic acid (tjn, with Tetra

chloracetamide, p. 6).
Chloracetic acids :

Monochloracetic acid . . .—

Trichloracetic acid . . . , 877
Chloracetones (s. Acetone, p. 29).

Chloracetonitrile 879

Chloracetyl —

Chloracetypbide ..... —

Chloral 880

Metachloral 882

Chloral, Amylic (s. Chloramylal).

Chloral, Mesitic ....._

Chloral, Propionic . • . —

Chloralbin 888

Chloraldehydes —

Chloride of trichloracetyl, or Per-

chlorinated acetic aldehyde . —
Cbloralide . . . . *. .884

Chloralofl 885

Chloraluric acid —

Chloramrlal —

Chloranil

(see Quinone and
Quinonic acid).

Chloranilamic acid

Chloranilamide

Chloranilammone

Chloranilic acid

Chloraniline (s. PhenylamineY

Chloranisic acid (s. Anisic acid, p. 802)

Chlorastrolite

Chlorates

Chlorates of Aluminium, Ammo<

nium. Barium
.Chlorates of Cobalt, Copper, Lead,
Lithium, Magnesium, Manganese,
Mercury

Chlorate of Nickel .

Chlorate of Potassium

Chlorate of Silver .

Chlorate of Sodium

Chlorates o( Strontium, Uranium

Zinc

Chlorhydrie or Hydrochloric acid .
Chlorhydric ethers (p. 897).
Chlorhydrins ....

Chlorhydrophenide (& Phenyl).
Chlorhydroproteic acid .
Chlorides :

1. Metallic chlorides

2. Chlorides of Organo - metallic

radicles . * .
8. Chlorides of Alcohol-radicles

4. Chlorides of Aldehyde-radicles

5. Chlorides of Acid-radicles •

886

887

889

890

898
894

896
897
898

1134

INDEX TO

PAOB

Chlorindatmita . • • . .900
Chlorindin (a. Indin).
Chlorine :

Antichloristic theory . . . 902
Chlorine, Detection and Estimation of:

1. Reactions 903

3. Quantitative estimation . . —
8. Separation fix>m other element* . 904

4. Atomic weight .... —
Chlorine, Hydrate of .... 906
Chlorine, Oxides and Oxycen-acids of . —

Hypochlorous acid and anhydride . 907

Hypochlorites .... 908

Chlorous anhydride, add, and salts 909

Chloric acid and salts . . . 910

Perchloric acid and salts . . —

Perchloric oxide and Encfalorine . 912

Chlorine, Sulphides of ... . 913

Chloriodoform .....—

Chlorisamic add and Chlorisamide (s.

Isamic acid and Isamide).
Chlorisatic acid (b. Isatic add).
Chlorisatyde Chlorisatydic add (s. Isa-

tvde and Isatvdic add).
Chlorisatin ^s. Isatin).
Chlorisatosulpldtes (s. Isatosulphites).

Chlorite ^

Chlorite earth; Chlorite, fermgi-
nons ; Chlorite-slate ; Chlorite-

spar 914

Chlorites ~

ChloritoTde 915

Chlorobenzaldide (s. Bensoyli Chloride

of, p. 666).
Chlorohenzamidfi (s. Benzamide. p. 640).
Chlorobenseue (s. ISenxene, p. 648).

Chlorobenzil —

Chlorobenzdc acid (s. Benzoic add,

p. 666).
Chlorobenzol (s. Benivlene, Chloride of,

p. 697).
Chiorobenzonitrile (s. Benzonitrile, p.

668).
Chlorobenzophenide (p. 654).
ChlorobenzoyI, Chloride of (667).

ChlorocafTeine -—

Chlorocamphene (s. Camphene, p. 724).
Chlorocarbo-hyposulphuric acid, S3m.

with Trichloro-methylsulphorous add

fsee Methyl).
Chtorocarbonic acid (p. 774).
Cbloroearbonlc ethers .... 916
Chlorocerotic add (s. Cerotio acid, p.

887).
Chlorodnnamic acid (see Cinnamic

acid).
Chlorocinnose (s. Cinnaroyl).

Chlorochloric add —

Chlorocomenic acid (s. Comenio add).
Chlorocumene (see Cumene).
Chlorocuminol (s. Cuminol).

Chlorodraconedc add (syn. with Chlora-

nisic acid. See Anisic add, p. 802).

Chlorodracon^l 917

Chloroenanthic acid (s. (Enanthic add).

Chloroform —

Solubility of alkaloids in chloroform 919
Chloroformyr-hypoaulphuric acid (s>'n.

with DichloromethylSulphurous acid.

Se^ Methyl).
Chlorogenic add (s. Caffetannic add, p.

709>

FAGB

C%lorogen!n 9zU

Chloromelal

Chloromdane (a. Cronstedtite).
Chloromelaniline (s. Melaniline).

Chloromercnrates -.

Chloromedtate of Methylene ~

Chloromethylase —

Chloronapthane (a. Naphthalene).
ChloTonaphthalic acid (s. Naphthalene,
Chlorine-derivatives of).

Chloronicdc add —

C^iloropai -.

Chloropalladatea ^

Chloropalladites _

Chloropalmitic add (s. Palmitic add).
Chloroperchloric add .....

ChloTophsNte m

Chlorophcnerite —

Chlorophane —

Chlorophenesic add\
Chlorophenisic add [ (s. Phenic add).
Chlorophennsic add J

Chloropbenyl —

Chlorophosphide of Nitrogen (s. Nitro-

gen).
hi<

CblorophyU —

Chlorophyllite —

Chloropicrin 92S

Bromopicrin —

Chloroplatinates —

Chloroplatinites —

Chlororhodates "

Chlororubin (s. Bnbia and Madder).
Chloroaalicin (s. Salidn).
Chlorosaligenin (s. Saligenin)*
Chlorosamide (syn. with Hydride of
Chlorosalicyl ; a. Salicyl).

Chlorospind >—

Chlorostrychnine (a. Strychnine),
(^lorostyradn (s. Styxacin).

Chlorosncdc acid 924

Chloroeuodnimide f s. Sncdnimide).
Chlorosulphuricadd (s. Sulphnryl, (Chlo-
ride of).
Chloroterebene (s. Terebene)^
Chlorovaleriaic and Cblorovaieroaic adds

^s. Valeric add)
Chloroxalovinic add (s. Oxalic ethera).
Chloroxamethane (s. Oxamic ethers).
Chloroxethide (s. Oxalic ethera).

Chloroxethoee —

Cbloroxjmaphthalic add (a. Oxynaph-

thalio add).
Chochoca . . . . . • —
ChodnefBte (a. Cryolite).

Cholacrol . ' —

Cholalic add —

Choldc acid —

Cholesteric add —

Cholesterin 926

Cholestrophane ..... 926

Cholicacid —

Cholochrome ...... 927

Cholochromic add 928

Chololdanle add 929

Choldfdic add .....—
Cholonic add ..... —
Chondrin .... .930

Chondrodlte ......—

Chondrogen —

Chondrottea —

Chonicrite —

Chrismatin — >

Christianite (s. Phillipdte).

THE FIRST VOLUME.

1135

Cfaroinaies . • . •
Cbromates of Ammonium
Chromate of Barium
Chromate of Bismuth
Chromate of Cadmium
Chromate of Calcium.
Chromate of Calcium

and

mum . •

Chromate of Cerium

Chromate of Chromium

Chromate of Cobalt

Chromates of Copper
Ammonio-chromate
Chromate of Copper and Potaa
eium

Chromate of Glucinom

Chromate of Iron .

Chromates of Lead :
Neutral chromate
Di- basic chromate
Sesquibasic chromate
Chromate of Lead and Copper

Chromates of Lithium, Magnesium,
Manganese, Mercniy, Molyb-
denum, Nickd . • •

Chromates of Potassium .
Neutral chromate •
Acid chromate • •
Hyperacid chromate .
Chromate of Potassium and Am

Potas

PAOB

930
982

monmm ....
Chromate of Potassium with Mer

curie chloride .
Chromate of Potassium with Mer

curie cyanide .
Chromocnloride of Potassium
Chromates of Silver

A ramonio-chromate
Chromates of Sodium, Strontium,

Tin, and Uranium

Chromates of Vanadium and Yttrium

Chromates of Zinc .

Ammonio-chromate .

Chromate of Zinc and Potassium

Chrome-alum

Chrome-p^reen ....
Chrome-iron ore ....

Chrome-mica

Chrome-ochre

Chrome-red and Chrome'jellow •
Chromite (s. Chrome^iron ore).
Chromites (p. 960).

Chromium

Chromium, Bromides of.
Chromium, Chlorides of:

Protochloride ....

Sesquichloride . . . .

Chromium, Detection and Estimation of

1. Blowpipe reactions .

2. Reactions in solution .
8. Quantitative estimation

4. Separation from other elements

5. Valuation of Chrome- ores .

6. Atomic weight of Chromium
Chromium, Fluorides of:

Sesouifluoride ....

Trifluoride ....
Chromium, Iodides of . . .
Chromium, Nitride of . .
Chromium, Oxides of:

Protoxide, or Chromous oxide

Chromoso-chromic oxide

Sesquloxide, or Chromic oxide
Chromic hydrates . .

938

934

935
936
937

938

939

940

941

942

943

944

945
946

947

.Q51
952

958

954

955

948
949

FAGB

Chromium, Oxides of:

Chromic salts . • • . 950
Chromites .... —
Compounds of Chromic oxide
with Ammonia ... —

Brown oxides of Chromium, or
Chromates of Chromium

Trioxide, or Chromic anhydride .
Chromic acid ....

Perchromic acid ....
Chromium, Oxychlorides of .

a. Compounds of sesquloxide and
sesqnichloride of chromium .

h Chlorochromic anhydride .
Chromium, Oxygen-salts of .
Chromium, Phosphide of . . •
Chromium, Sulphides of . . . .
Chromotartaric add ....
Chromule (syn. with Chlorophyll).

Chryiodine —

Chrysamide —

Chr}'samidic acid .,...—

Chrysammic acid —

Chrysanilic acid . . ^ . . 957
Chrysanisic acid ..... —
Chrysanthemum segetum . . . -^

Chrysatric acid —

Chrysene 958

Chrysobeirl —

Chrysocolfa -»

Chrysoharmine (syn. with Nitroharmine).
Chrysolepic acid (syn. with Picric acid).

Chrysolite — .

Chrysophane (s. Clintonite).

Ohrysophanic acid —

Chrysoprase ...... 960

Chrysoprase earth (s. Pimelite)
Chrysorhamnin. — Chrysotile . . —

Chulariose —

Chusite (s. Olivine).

Chyle .......—

Chyme . . 962

Chymosin ...... —

Chytophyllite —

Chytostilbite —

Cibotinm —

Cicer —

Cichorium —

Cicntine 968

Cider —

Cimicicacid 964

Cimmol (s. Cinnamyl, Hydride of, p. 990).

Cimmvl —

Cimohte ..*...

Cinacrol

Cintebene

CinsBphane, Cinnphene, Cinssphone
Cinchona barks :

Occurrence •

Varieties . • •

Composition •

Reactions

Estimation of Alkaloids
Cinchona- red .
Cinchona-tannic acid (s. Quinotannic

acid).
Cinchonetine . .
Cinchonicine . . •
Cinchonidine .

Salts of Qnchonidlne

Methvl-dnchonidine
Cinehonin'e . . .

Beta-dnchonine

Salts of Cinchonine .

965

966

967
968
969

971

972
973

974
975

1136

INDEX TO THE FIRST VOLUME.

PAOB

Cinchonine :

firominated and Chlorinated Deri-
Yat6S of Cinchonine :
Bromocinchonine
Sesqai-hromocinchonine
Dibromocinchonine .
Dichlorodnchonine .
lodocinchonine .
Derivatives of Cindionine contain
ing Organic Kadicles :
Benzoyl-cinchonine .
Methjl-cinchooine •
Cinchovatine ....
Cinnabar (a. Mercoiy).
Cinnamein ....
Cinnamene, or Styrol , •
Metadnnamene . •
Bromide of dnnamene .
NitrocinnameQe •
Cinnamic acid.' . . •
Cinnamatea • .
Cinnamic ethers ;

Cinnamate of Ethyl .

Cinnamate of Meuiyl

Cinnamate of Cinnyl ; StyradH

Bromodnnamic add

Chlorocinnamic acid

Nitrodnnamic add .

Nittodnnamic ethen

Cinnamic alcohol (a. Cinnylic alcohol,

p. 992).
Cinnamic aldehyde (a. Cinnamyl, Hydride

of, p. 990).
Cinnamic anhydride

Nitrodnnamic anhydride

Cinnamide

Nitrodnnamide
Phenyl-cinnamide .
Kitraniayl-dnnamide, or Cinnitra
niddine ....
Cinnanilide ^s. Cinnamide).
Cinnhydramide ....
Cinnamon, OU of, and Oil of CaMia

Reiina from cinnamon dl
Cinnamon-stone ....

Cinnamyl

Cinnamyl, Chloride of . . .
Cinnamyl, Ci'anide of . • .
Cinnamyl, Hydride of .

Compoand with Hydrochloric add
Compoand with Iodine and Iodide

of potassium
Compoond with Nitric add
Compoands with Add sulphites of

alkali -metals
H vdride of Tetrachloro-cinnamyl

Cinnyf

Cinnylic alcohol ; Styrmu
Cipolino ....
Cissampdine (a Pelosine).
Citraconamides and Citraconanilides (a.

Citraconic acid, Amidea of).
Citraconic add

Citraconatea .
Citraconic acid, Amides of:
Citraconamide
Citraconimide .

Pbenylcitraconimide, or CStra

conanil .
lodophenylcitraconimide
Di ni trophenylcitraconimide
Citraconamic acid . . • .
Phenylcitraconaroic and Dini
trophenylcitraconamic add

978

979

980

981
982

988

985

986

987

988

989

990

991

992

992
993

997

999

1000

1001

P94

PAQV

Citraconic anhydride .... 994
Citraconic, or Pyrodtric diloiide • • —
Citraconic ether (p. 993).
Citramidea (p. 1000).
Citraconimide (p. 993).
Citraconiodanil (ayn. with lodopheoyl-

dtniffonimidf, (p. 990).
Citrene ....
Citric add

Citrates .

Ozychlorodtric add
Citric add, Amidea of .

Citramide

Phenyldtramlde

Phenyldtrimide

Phenyldtramic add

Diphenyldtramic acid
(Htric ethers . . •

Citrates of methyl

Citrate of ethyl
Citridie add (a. Aconitic add, p. 54).
Citrilene (a. Citrene^ p. 994).

Citrin —

Citrins —

Citroceric and Gitrolic adda . . • —
Citrobianil, or Gitrodianil (a. Citric add,

Amidea of)
Citrobianilic or Citrodiaailic add (a.

Citric add, Amidea of, p 1000).
Citroglyoerin (s. Citrias).
Citromannitana .... . — >
Citron, Oil of ([a Citroa medics, p^ 1004).

Citrus Anrantium 1002

atmsBergamia 1003

Citma Bigaradia • . • • • —

Oitros Limetta —

Citrus Limonum —

OU of Lemon ..... ^
Hydrate of Lemon-Oil . . 1004
Hydrochlorates of Lemon-oil • —
Lemon-camphor, or Cttroptene ~~

Citrus Lnmia 1005

Gtms medica 1006

Citryl —

Civet —

Clariflcatioa 1007

Claasification . . • • • • —

Clauathalite 1023

Clay —

Clay-alate 1025

Clay iron-stone .«..• —

Clayite —

Cleavage of Cryttala • . • . —
Cleavlandite ..•••• —

Cleophane —

CIematis*camphor . • . • • ^-
Clematitin ......—

Clingmannite (a. Margarita).

Clinkstone ..•••• ^

Clinochlore —

Clinodase (s. Abichite). . . . 1026
Clintonite ....•• —

Clouds —

Cloves, Oil of 1029

Clororubrin —

Club-moss (s. Lycopodinm).

Cluthalite —

Cnidn ...••..—
Coagulum ... . • —

Coal —

Coal-gas 1035

INDEX TO THE FIRST VOLUME.

1137

PAOB

Cobalt 1089

Cobalt, Alloys of 1041

Cobalt, Bromide of —

Cobalt, Chlorides of .... —
Cobalt, Detection and Estimaticm of:

1. Blowpipe reactions • • . 1042

2. Reactions in solution ... —
8. Quantitative estimation . . 1044
4. Separation from other elements . 1045
6. Valuation of Cobalt-ores . . 1048
6. Atomic weight of Cobalt . . —

Cobalt, EarthT —

Cobalt, Fluoride of . • . . -^

Cobalt, Iodide of —

Cobalt, Oxides of —

Cobalt, Oxysnlphide of . . . . 1050
Cobalt, Oxygen* salts of . . . —
Cobalt, Phosphides of ....--

Cobalt, red —

Cobalt, Selenide of —

Cobalt, Sulphides of .... ^
Cobalt-bases, Ammoniacal . . • 1051

Diammonlo-cobaltic salts • . —

Triammonio-cobaltic salts . . —

Tetrammonio-cobaltic or Fusco-co-
baltic salts —

Pentammonio-cobaltic (Roseo- and
Purpureo-cobaltic) salts . . 1052

Nitroso - pentammonio - cobaltic or
Xantbo-cobal tic salts . . . 1054

Hexammonio cobaltic or Luteo-co-
baltic salts 1055

Ammonio-percobaltic or Oxyoobal-
tic salU 1056

General formuI» of the Ammonia*
cal Cobalt-compounds ... —

Cobalt-bloom 1057

Cobalt-blue . • . , , . —
Cobalt-glance (s. Cobaltine).

Cobalt-green ^

Cobaltine —

Cobalt-mica (s. Cobalt-bloom).
Cobalt-pyrites (s. Cobalt, sulphides of). 1058

Cobalt-Titrioi —

Cobalt-yellow —

Coca.— Cocaine 1059

^^^'•^•^j^eCoc. . . .1060

Coccin. — Coccinite . . • . • —
Coccinnic acid. — Cocdnonic acid . . — ^

Coccodea viridis —

Coccognic acid —

Coccoiite —

Coccoloba —

Coocnlin (js. Picrotoxin).

Cocculus mdicus —

CoGcnsio acid -*

Cochineal —

Cochineal-red 1062

Cochlearia.~Cochlearin . . . .1063

Cocinic add —

Cocinin —

Cocinone —

Cocoa-nut oil —

Codeine 1064

Salts of Codeine .... 1065

Substitution -products :
Bromocodeme .... 1066
Tribromocodeine .... 1067
Chlorocodeine .... —

PAGE

Codeine

Substitution-products :
Cyanocodeine .... 1068
Ethylcodeine , . , • -^
lodocodeine • . • . —
Nitrocodeine . • . . —

Ccslestin 1060

Coslodine • —

Coeralicacid ... • . . —
Oarulin . . . . . . . —

Coffee —

Coflbe-leaves 1075

Coffeine (s. Caffeine).

Cognac 1076

Cohobation ......—

Cohesion and Adhesion . • • . —

Colchicine 1080

Colchidne — -

Colchicum 1081

Colcothar 1082

Colletiin. • —

Collidine —

Ethyl-coUidine .... 1083

CoUinic add —

Collinic aldehyde —

Collodion —

CoUyl, Hydride of 1084

CoUyrite —

Colocynthin —

Colocynthitin ....... 1085

Colombic acid. — Colombin . . . —

Colombo root 1086

Colophane. — Colophene. — Colophilene . —

Colopholic acid 1087

Colophonic acids —

Colophonite —

Colophonone —

Colophony —

Colorimeter 1088

Colorin . —

Colostrum —

Colour. — Colouring matters . . . 1088
Colurabite. — Columbium . . . 1089

Combustion —

Conditions of Inflammability . . 1094
Nature of flame .... 1096
Causes which modify and extinguish

combustion 1100

Comenamethane 1102

Comenamic add —

Comenic acid 1103

Comenates 1104

Bromocomenic add . .1105

Chlorocomenic acid . . .1106
Ethylcomenic add .... —

Comptonite 1107

Concentration ..... —

Conchiolin —

Concretions, Animal .... —

Condensation 1110

Condrodite (s. Chondrodite).

Condurrite -^

Conglomerate —

ADDENDA.

Acetylene
Allylene .
Caesium .

nil
1112

mm OF THE FIB6T TOLVMS.

VyJL. I.

4 D

vWi

LOKVOir

PSXirTXX) BT 8POTTX8WOODB AITS CO.

KBW'flXSIET BQVABl

• 7^

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Books

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "A dictionary of chemistry and allied branches of other sciences"

See other formats