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^M 



f 



CHEMISTRY: 

GENERAL, MEDICAL, AND PHARMACEUTICAL. 



At (he First Lnternational Pharmaeeutmil Exhlhi- 
(ion, held in Vienna in Anyu^^ 1 883, for (hiti 
Manual t/ie Anchor wa.H awarded a Go/a Jf('d(d. 
A( the Se<*ond, held in JVa(/tte in IS! fa, he 
received for (he book (he s(U( higher, indeed 
the hi{fhes(^ prize of a Diploma of Honor, 



The Nineteenth Edition of thi^ Manual han been 
rcvii<€d from the Kujhieenih English Edition 
and M adapted to conform to the new United 
Sta (en Ph a rm acojnv ia. 



CHEMISTRY: 

GENERAL, MEDICAL, AND PHARMACEUTICAL, 

INCLUDING 

THE CHEMISTRY OF THE U. S. PHARMACOPffilA. 



A MANUAL 

ON THE SCIENCE OF CHEMISTRY, AND ITS APPLICA- 
TIONS IN MEDICINE AND PHARMACY. 



BY 
JOHN ATTFIELD, F.R.S., 

M. A. AND PH. D. (xf BINGEN), F. I. C, F. C. R. 
PROFFXSOR OF PRACTICAL CHEMISTRY TO THE PHARMACEUTICAL SOCIETY OF GREAT 

BRITAIN, 1862-96; FORMERLY DEMONSTRATOR OF CHEMISTRY at sT Bartholomew's 

HOSPITAL, LONDON; HONORARY MEMBER OF TWENTY-THREE SOCIETIES, 

ASSOCIATIONS. AND COLLEGES OF PHARMACY IN EUROPE AND AMERICA ; 

ONE OF THE THREE EDITORS OF THE BRITISH PHARMACOPlEIA. 1885; 

EDITOR OF THE ADDENDUM TO THE BRITISH PHARMACX)P(KIA, 

EDITOR OF THE BRITISH PHARMACOPCEIA, 1898, AND 

OF ITS INDIAN AND COLONIAL ADDENDUM, 1900 

Edited by LEONARD DOBBIN 

PH. D. (WORZBURO), F. I. C, F. C. S. 

LECTTREB ON CHEMISTRY IN THE UNIVERSITY OF EDINBURGH: LATELY 

EXAMINER IN CHEMISTRY ON THE BOARD OF EXAMINERS FOR SCOTLAND, 

OF THE PHARMACEUTICAL SOCIETY OF GREAT BRITAIN 



NINETEENTH EDITION 




LEA BROTHERS & CO., 
PHILADELPHIA AND NEW YORK, 



Copyright, 1906, by 
LEA BROTHERS & 00. 



Authority to use for comment the PharmacopoBla of the United 
States of America (Eighth Decennial Revision), In this volume, has 
been granted by the Board of Trustees of the United States Pharmaco- 
poBlal Convention ; which Board of Trustees Is In no way responsible 
for the accuracy of any translations of the Official Weights and 
Measures, or for any statement as to strength of Official Preparations. 



|H>KNAN, TRINTKR, 
PHII.ADKI.PHIA. 



C3 I 



" But the grreatest error of all is, mistaking the ultimate 
end of knowledge : for some men covet knowledge out of a 
natural curiosity and inauisitive temper; some to entertain 
the mind with variety and delight ; some for ornament and 
reputation ; some for victory and contention ; many for lucr«» 
and a livelihood ; and but few for employing the diviae 
gift of reason to the use and benefit of mankind."— Lord 
Bacon. 



"I hold that the greatest friend to man is labor; that 
knowledge without toil, if possible, were worthless ; that 
toil in pursuit of knowledge is the best knowledge we can 
attain; that the continuous effort for fame is nobler than 
fame itself; that it is not wealth suddenly acquired which 
is deserving of homage, but the virtues which a man exer- 
cises in the slow pursuit of wealth— the abilities so called 
forth, the self-denials so imposed; in a word, that Labor 
and Patience are the true schoolmasters on earth."— Lord 
Lytton. 



*' I want to l«am all that one human being can. It is 
awfiil to be buried alive in the coffin of one's own ignorance 
and helplessness."— Orauaii Travers. 



PEEFA.CE. 



The short title on the back of a hook, and even the Herds on 
the title-page, are generally, and even ueeesHanlj^ imperfeet 
descriptions of the contetits^ and henee not unfrequently iuduce 
at the outset miseoneeptions in the minds of readers. The 
author of Vhvmi»fr^ : Gtitrml, Mrihaif, am! PhfirmfUvttfkud^ 
would at once state, therefore, that his chief aim is to teach 
the science of chemistry to medical and pharmaceutical 
pupils. So far as laws and principles are concerned, the book 
ia a work on General Chemistry ; but inasmuch as those laws 
and principles are elucidated an<l ilhiHtrated by that large por- 
tion of chemistry which is directly interesting to medical prac- 
titioners and pharmacist!^^ tlie bfiok may be said U^ be a work 
on Medical Chemistry and on Pharmaceutical Chemistry. Only 
in this conventional sense would the author speak of Medical 
and Pharmaceutical (liemistry ; lor the truths of chemistry 
are the same for all students — crystalline verities which cannot 
bt* expanded or compressed to suit any class of workers. The 
leading priiiciples of the science, however, can iiA easily he 
illustrated by or deduced from those facts which have interest 
as from those which have little or no special interest for the 
fullnwers of medicine and pharmacy. The grand and simple 
leading truths or laws of chemistry, the lesser truths or pnn- 
dpIcSf and nearly all the interesting relationships of elements 
and compounds — in a word, the ncittKr af chemistry — can be 
laughl tti medical and phiirmaceutieal students with little other 
aid than that afforded by the utatcrials which lie in rich abun- 
dance all around these workers. ♦Such a mode of teaching the 
*;erieral principles of ihe science and their applications in medi- 
cine ami pharmacy is adojited in this volume. It la a mode which 
greatly increases tlto usefulness ol' the science to the students 

vii 



o^o 



M 




Vlll PREFACE. 

chiefly iiddressed, while it in no way dirainifthes the value of 
clienjistry to them ;i8 an in^trunient <if' mental culture — an 
instrument which sharpens and expands the powers of observa- 
tion, which enlarges and strengthens memory and imagina- 
tion, whieh gives poiiit to the perceptive facuUieSj and whieh 
develops and elaborates the powers of thf night and uf reason. 

ThiH Munuul is intended, then, as a systematic exponent of 
the science of chemistry, but is written mainly for the pupils, 
assistants, and principals engaged in medicine and pharmacy. 
Tt is a Manual of Applied Chemistry or Technical (Chemistry, 
but it is first of nil a Manual of Chemistry, 

Tlie book will be f<>und equally UKeful as ji reading-book for 
Btudents having no opportunities of attending lectures or per- 
forming experiments, or, on the other hai\d, as a text-book for 
college pupils; while its eomprehfnsive Index, containing 
nearly ten thousand references, will fit the work for aft-cr- 
consultatirm in the course of business or professional practice. 

From most uther chemical text-books it differs in three par- 
ticulars : first, in the exclusion of matter relating to compounds 
which at present are only of interest to the scientific chemist j 
whose aims have no special relation to medicine and pharmacy ; 
secoiidlyr in ci>ntaiiiing more or less of the ehemislry of every 
Bubstanee recognized officially or in general practice as a 
renu'ilijil agent ; thirdly, in the paragraphs being so east that 
the volutne may be tt»ed afi a guide in studving the science 
experimentally. 

The order of subjects is that which, in the author's opinion, 
beat meets the rc(|uircmcnts of medical and |>harmafeuiicftl 
atudents in Great Britain, Freland, India, the British colonies, 
and the United States of America. Introductory pages are 
devoted to a few leading properties rtf the elements. A 
review of the facts thus unfcdded aflfurds ttpport unity for st4»t- 
ing the views of philosophers respecting the manner in which 
these elements influence each otht*r as components of ti^rres- 
trial matter. The consideration in detail nf the rtdations of 
the elementary and compound radicals follows, synthetical and 
analytical bearings being pointed out. and attention frequently 



PREFACE. ix 

directed to connecting or iiuderljiiig truths nr general prin- 
ciples. The cliemistry of siibstances met with in vegetables 
anil animals, or of simihir substances artificially produced (the 
so-called ''organic ehemiiitrj' "), is next considered. Cliemicul 
toxicology and the chemical as well an microseopical chamcter^ 
of morbid urine, urinary sediments^ and ealeuli arc then given. 
The concluding sections form a hiboratory-guidc to beginners 
in the study of quantitative analysis. 

In ibii euur?sc of the treatmeut outlined in ibe preceding 
paragruph it will be observed tliat tlie whole of the elements 
are first noticed very shortly, to give ihe pupil a general view 
of his course of &tudy, and afterward at Ictigrh and thor- 
oughly ; that the chcnustry of the metallic radicals precedes 
that of the acid radicals (a Ici'm applied consistently through- 
out the Man mil to designate that purt o\^ each of the acids 
which is not rcplaeeabl(! hydrogen) ; and that while the 
tnetaIHe radicals are iirninged ueeording to their annlvti<'!il 
rcdations^ the coninittn radicals arc arranged according to 
exchangeable value or r|u:intivalenceT and the rurer acid 
radicals alphabetically. By this plan the more important 
facts and principles arc repeatedly hnmght under eonsideraijun, 
the points of view, however, differing according as interest is 
concentrated on physical, synthetical^ analylical, or i^uantitative 
properties. This arrangement of matter was adopted, iilso, partly 
in the behef that the separate and general truths of chemistry 
ncvcrdo or can enter the mind in the order of any seienlitie classi- 
fication at presicnt pos.sible, (^hemieal facts are not yet united 
by any single, consistent theory. In the current state of 
chemical knowledge consistency in the methodieiil arrangement 
even of elements can only he carried out in otie direction, and 
i» necessarily nccompnnied by incousisteneics in other directions 
— s result most perph*xing to learners, and hence totally sub- 
Tersivc of the chief advantages of classification For this reastiri 
the writer ban preferred to lead up t<i. rather thnn follow, scien- 
title cinssification — has allowed analogies and afiinities to 
«iiggesl» rather than be suggested by, classification. Among the 
aciduloua radicals^ especiaity, any km>wn system of classification 



X PREFACE. 

would have given undue prominence to one «et of relations, 
ill id undeserved obscurity to otUers, Then, b}' sejmnidng 
more inifiortiiut from less iiiiptirtant matter, iiiHtruetion is 
adapted to the waists of gentlemen whtise »jjjportunitie}4 of 
studying chemistry vary gretitly, and are untivoidiibly insuf- 
fieient to enable them to gain a knowledge of the wljole area 
of the science. One great advantage ul' the mode of treat- 
meat is, that difficulties of nonieneiature, notation, chemieal 
constitution, and even those arising from conventionality of 
language^ are explained as they arise, instead of being mas:<ed 
under the head of ** Introduetor}^ Chapters/' '' Preliniinary 
Considerations/' or '^ Cieneral llemarks/- which are not unlVe- 
quently too difficult to be understuuil by h beginner, too vo- 
luminous to he remeuibered except by the aid of suhset[uent 
lessons, and are conse(juentIy the cause of much trouble and 
confusion* This plan has also admitted of greater prom- 
inence being given to 'The tJeneral iVineiples of (nieniieal 
Pbilosophyt' the only set-tion to whirh the .student is asked 
freijueiitly to return until he tiuds himself natn rally empbiytng 
ihowe principles in the inierpretalion of the phenomena fihttiiiied 
by experiment. 

The metric system of weights and measures (that which, 
doubtless, is destined to supersede all others) is alone used 
in the sections on (juaniitative analysis. In other parts of 
the Manual avoirdu|Hjis weights and imperial measures are 
employed, necessarily . 

It is hoped that ihe numerous etymobigicnl references scat- 
tered throughout the ful lowing pages will be found useful. 
Words in (Ireek continue to be rendered, by special request, 
in Mnglisb characters, letter for h-ttcr. The word '' oflieial '* 
is used thryughout for things reeognixed officially by the com- 
pilers of pharmaeopujias. 

Chemical substJUices rccogniied in the Fnited Btates Phar- 
xnacopccia, but not in the Hntish Pharmacopueia, have, never- 
theless, u certain amount *if notice in the British editions o\^ 
the Manual, and the chemical aubstancea official in Great 
Britain are noticed in the Ameriean editions. 



PREFACE. XI 

Students are strongly recommended to test their progress by 
frequent examination. To this end appropriate questions are 
appended to each subject. 

The author's ideal of a manual of chemistry for medical and 
pharmaceutical students is, then, one in which not only the 
Acience of chemistry is taught, but in which the chemistry 
of every substance having interest for the followers of med- 
icine and pharmacy is noticed at more or less length in pro- 
portion to its importance, and at least its position in relation 
to the leading principles of chemistry is set forth with all 
attainable exactness. The extent to which he has realized 
this ideal he leaves to others to decide. Such a work will 
doubtless in certain parts partake of the character of a diction- 
ary ; but this is by no means a fault, especially if a good index 
be appended, for the points of contact between pure and applied 
chemistry are thus multiplied, and abundant outlets supplied by 
which a lover of the science may pass into other chemical domains 
by aid of other guides, or even into the regions of original re- 
search. Among the rarer alkaloids, bitter bodies, glucosides, salts 
of organic radicals, solid fats, fixed oils, volatile oils, resins, oleo- 
resins, gum-resins, balsams, and coloring-matters mentioned in 
this volume, will be found many such points whence the ardent 
student may start for the well-known, the less-known, or the 
untrodden paths of scientific chemistry. 

WaTPOKD, HkRTS, ENCiLANI), 

iSepteniber, 190C. 



LIST OF PREVIOUS EDITIONS. 



No. OF 
Edition. 



Date. Notes. 

1 18()7 A hand-book of practical chemistn' only. 

2 18G9 This and succeeding edition.s include<l the 

chemistry of the British Pharniacoi)cria. 

3 1870 American edition ; adapted to the United 

States Pharmac(>pa?iii. 
English edition. 
American edition. 
English edition. This and succeeding editions 

contained notices of substances inchi<led in 

the Indian Pharmacopa»ia. 
American edition. 



English editions. 

American edition. 
English edition. 
American edition. 
F^nglish e<lition. 
American edition. 
English eilition. 
American edition. 



4 


1872 


5 


1878 


G 


1875 


7 


1870 


8 


1879 


9 


1881 


10 


1883 


11 


1885 


12 


1889 


13 


1889 


14 


1893 


15 


189.^ 


Ifi 


1898 


17 


1898 


18 


1903 



English editicms. 



ADVICE TO STUDENTS 
RBSPECTING THEIR OBJECT IN STUDYING. 



Avoid studying chemistry , or indeed any subject, merelj/ by 
way of " preparation for examination ;" all ordinary " exam- 
inations '* being, admittedly, inefficient tests of competency. 
Do not so mistake the means for the end. You are studying 
to fit yourself for your position in the world. Work dili- 
gently, study thoughtfully and deliberately ; above all, be 
thorough, otherwise your knowledge will be inaccurate and 
transient, and will be unaccompanied by that enlightenment 
of the understanding, that mental training, mental discipline, 
and general elevation of the intellect, which constitute, in a 
word, education. When you are thus educated you will with 
ease and pleasure pass any examination in the knowledge you 
have thus acquired. 

All authorities on education, whether statesmen, teachers, 
or examiners, regard " examinations," even by the most highly 
skilled " Board," with ample time at its disposal and a wide 
area from which to select questions, as but a partial test of 
knowledge and an imperfect test of education. It is the least 
unsatisfactory, however, that has been devised, and is especially 
useful when, following instead of leading education, it is re- 
stricted to the subjects of a well-defined, earnestly followed, 
compulsory public curriculum of study — a curriculum directed 
by a competent representative body, admidistered by properly 
qualified teachers, and followed by pupils who have had sound 
preliminary training. 

Students I in all honor and in the highest self-interest take 
care that any inefficiencies in8ci)arable from '' oxamination " are 
abundantly compensated by the extent and precisiini of your 
knowledge and by the soundness and thoroughness of your 
whole education. 



1 g»=??!??!??!?- 


«»»»»»»,.«-«o. ^^^^^^^^^^^^^^^^^^^^^^^^^^B^^^^^^^^^^^^^H 


] - 


^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 




APPARATUS. 




List of Aimuratih mm Exi-ehiments is Analysis. 




Lj?it nfjippanitu* Hoitiiblc for tho three months' courw? of pnw»ti' 
ciil fheioij^trv in tliii Muiiiwier sf^HKion oi' unxlicjil m'IiohIh *>r mr any 






fiimihtr .sitIl'S uf leKfwuiJs — iiiL'ludhi"^ the pr<'piiratit>o «^f i^t'iiifntury 




j5aH43s^ fttiniytical riMietioii!* t>reouiiiH>ii uietiLls* and iioidiiloiiH nulit^lH, 




analysis of sin^lo naltK^ fhmnk'ul t-*)xii'olo^Vf iind tlw I'xauuiiation 




uforiiM*, urinnry 8cdiment*, and eaifuli: 




Vhie ilozen tPHt-ttil><*8. 


A 12-ineh and a 3-ineh evaporat- 




fi^Ht-tubf* jstand. 


ing-haHin, 




'rejiit-tul>c eleiiiiio»^-I>riiHli. 


Two jtoreeiaiu cruciblea. 




A few pieces of ^hwH tuliiiii^, 


Blowpijie. 




eight U) t*ixt**eri inchen lon^^ 


<>ijeihle t^)ngK. 




with a few inehf^s of india-rul>- 


Unun<l file. 




her tuhio"^ to tit. 


Triansj^uhu* file. 




Small rtask/ 


Small retyrt-sUiud. 




Tnvo j^inall beakers. 


Sand* tray. 




'J'wf* rainall funnels. 


Wire triangles. 




Two wateh- glasses. 


Platinum wire ami foil. 




Two or three ^la*5« nxJa. 


Test- papers. 




Wa-sh-hottle. 


Filter-paper. 




Small ijentli^ and mortar. 


Towel, 




A 2-phit ejijthenware ha-'«iii. 


Two dozen eorks. 




{This set, parked in a oiSi\ran be obtained of iim^ rhrmirat^tppara- 




(tin ffHiker/or ahont sei^en d<itlarjt,) 




LkST OP" ApeARATlS Foil Kx PKR 1 Mfc NTS TN SyNTUESIS ANO AwLVXIS. 




A larger set, ^uitahle for the perforniaiiee of im^H of thf 8yiitln}t* 




iral on well m qiialitative analytieal experimentK de.<wTihe<l"in this 




Mtitmai : 




A set of evaporating- biiwnB, of the 


Two K^iup'plat^s. 




fill low in *^ r^rivH : 


(hie tl at- pi ate. 




One 3-ineh; on** 4*inch; one*>}- 


Two s|»aiala knives. i 




iiich; oneTi-ineh; one 8J-inidL 


One pair of scissors. 




One ret4)rt-Htand and three rings. 


One round tile. 




Two test-;ihi8«e8. 


One trianguhir file. 




()iii3 half-pint fla^ik. 


Ilulf a pound of gla.<«8 rod. 




Haifa cpiire of tilKT-napcr. 
Two pf)ret*lain erueihles. 


Haifa pound of ghij^H tubing. 




One foot of «mall indiji-ruhher 




*hie ineawiire-^laHfi, '> ox. 


tubing. 




IMowpipe, H-inrh. 


Three dozen corke of Tarioua 




Two glaji« funnels. 


sixefl. 




One dozen te.^ttuhes (hard glass). 


Plnttnum wire and foil. 




One test-tube hrufih. 


Test-papen*. 




One pair of H-ineh bra^s erueible 


A nest of three beakers. 




ton|5*«. , 


(hie lest- tube f*tuml 




(ThtJt se ft packed in a f^xr.ean he oi/tnincdofany chemirat-afTpara- 




tttM fnftketfnr n^mt ttreJrr dftiiar.f.) 




A sponge, towels, and a nnt<^-lKM>k may he included, 

XIV 


^ 





APPARATUS, 



XV 



List op Furniturb of a Chemical Laboratory. 

The foUowirig appamtus should be ready to hand for etudf^nt^ fol- 
lowiui: an extended course of pniotical chenotstrj, in a room net 
apart for th« purpose : 



Test-tulio ritrk» two fiozon liok*«. 
I rem stand w I'vlimitT furj^upport- 

in*; litr^t> dislir^s* 
Iron adapt<*r« lor titting diahcs Uy 

Pestle and niortiir* ^ or inehcs. 
One ("p-inefi funnel. 



A lx»nch or table and Ktool. 
WatA^r-supply and wa»te-pipL\ 
A cuplioard attaehtHl t^i aehimney 

with an outward drau^rbt. 
A furnace fed with coke ; tong», 

hot-|>late or sand-bath, etc, 
A \Ttt«te-box. 
Slielvefi for chemieal and other I Browii pan, I- or 2-gal!on* 

inat4'nAl$ in jarB c»r tmttle^. Wliite jiii^, I -gallon. 

lTa--»'^upply and himp with dexilih> Water-lMittfev rpiart. 

tulM' (or a s[>irit-lanip and I Twenty -eight test-bottles, 6-o«. 

Sfurit). I 

Other artieles, such as fla^kjt, retorts. reeeiver«, condenser^t bir^e 
eTttp»rating-dishe8, may be obtained as wanted. In Quantitative 
Analy^ii^ the apparatus described In the sections on that subject will 
be required. 



y 



List of Fij:id Reaobntj*, 

Tertain cheinieal 8u}>f«tani'e!4 are used so fre<|uently in analytical 
proce-Hsc's that it is desirable to have t*Tnall <|uaiititieN placed in bot- 
tlejs in front of the of>erator (Seep. 22, ) Ak thene reii^'ent?* are 
|5«*ne rally employed in a state of scjlutiont nearly all tb*? Milid salts 
mav at once bo tiis^solveil (in iliKtilbnl w;iter). The b<ifiles enijdoyed 
i4MmId be well 8tnpf»ered, and of r» or *\ rHineew rapacity. Cntnniou 
fS,lsU'n Ijottlc* of Uhs sixe may be hatl b^r about one dr»llar and a 
iiuarter per doien. The iMittles s^lioiild not be more ibaii about 
three- fotirtJn* f«»ll ; Minjrle drnp>', if rerpjircil^ i-an then be [lonred out 
with e»iM« anr] priTision. The followini; lint of tr^t-Ndiition^ is 
t^r'om mended ; direction** for methods of preparing the Kub*<tiincea 
tint rpttilily purehaHnble will l>e found by referring to the Index: 



j^ulphurie Aeiii, (^one, ami dilute. 
Nitric Aeid» " 

I f yd r» nddorie Aeid * ' 
Vci^ie Aeid. iltlule. 



Potajj*!ium Flydroxide, 5 |>eix;ent, 
Soiliuuh r» to \'} iH'iveut. 
Hydroxide Ammonia, h» [>ereenL 
I Ame- watt-T, Hiit urated 



The next nine ma>' cttmtaiit nl>ont h» {>er(Tnt, of solid salt : 



\minoiiiiiin ^a^^>^lIlat«^ with u 
little 2^>bi(ion of Ammrtni^t 
arided. 

\ ninionium f "hloride. 

\ iinnoniuin Pbohphat^. 



.VniuiMitiam IfydroKulphide. 
li.uiuni Clilonde. 
(VIcinni (iilifrule, 
l*ota?isiiim (linnnate. 
iSudiyni Hitartrrtle. 



XVI 



SOLID CHEMICAL SUBSTANCKS 



The succeeding seven may have a strength of about 5 jKircent. : 



Potassium Ferrocyanide. 
Potassium Ferricyanide. 
Potassium Iodide. 
Ammonium Oxalate. 



I Ferric Chloride. 
Silver Nitrate. 
Chioroplatinic Acid. 



Lists of Solid Chemical Substances fob Study. 

List of chemical substances necessary for the practical study of the 
non-metallic elements mentioned on pp. 1 7 to 37. The quantities arc 
sufficient for several experiments : 

Potassium Chlorate . . . 1 oz. , Phosphorus i oz. 

Black Manganese Oxide . 1 oz. I Hydrochloric Acid ... J oz. 

Zinc . 1 oz. I Sulphur • J oz. 

Sulphuric Acid 2 oz. I Iodine J oz. 

List of chemical substances nec»€ssary ibr the analytical studv of 
the important metallic and acidulous radicals (pp. 71 to 301 ). The 
(|uantities will depend on the frequency with which experiments are 
rei>eated or analyses performed ; those mentioned arc sufficient for 
one or t^wo students. The eight substances mentioned in the above 
list are included : 



The set of test-solutions dcvscribed 

in the previoiLs section : 

Potassium Carbonate . . I oz. 

Tartaric Acid I oz. 

Litmus \ oz. 

Magnesium Sulphate . . 1 oz. 

Zinc Sulphate 1 oz. 

Alum 1 oz. 

FerroiLS Sulphide ... 1 lb. 

Oak -galls 1 oz. 

Potjussium Thi<>cyjinatc . 1 oz. 

Arsenic Trioxide . . . i oz. 

Zinc \ \h. 

Charcoal i lb. 

Ferrous Sulphate ... 1 oz. 

(.\)pper-f(>il 1 oz. 

Copper Sulphate .... 1 nz. 

Taftarated Antimony . . \ oz. 

Mercury ....... 1 oz. 

MeRMiric Chloride . . j oz. 

(Vlomel A oz. 

Tin i oz. 

PotJissiuin HiciirlMmate . 1 oz. Hcnzoic Acid 

Ix^id A«-ct:itr 1 oz. Fluor Spur 

Potas-sium (Vanidc . . A <»z. Tannic Aci<l 

So<lium Thitisulphate . . 1 oz. 
A Lithium SaU .... lOirrs. 

Strontium Nitrate . . . 1 oz. 



' Black Manganese Oxide J lb. 

Manganese Chloride . . . 1 oz. 

Cobalt (Chloride . . . . 50gr8. 

Nickel Nitrate i oz. 

Chromic (^hloride ... 1 oz. 

(lold -leaves 2 or 3. 

Cadmium Chloride . . J oz. 

Bismuth Nitrate .... \ oz. 

Potas-sium Bromide . . 1 oz. 

Starch . 1 oz. 

Potassium Nitrate ... 1 oz. 

(^pper borings or turnings 1 oz. 

Indigo i oz. 

I IVtassium Chlorate ... 1 oz. 
I L)dine \ oz. 

Alcohol (9<) to 95 i»er cent.) 1 oz. 

Sulphur 1 oz. 

l^otassium Acid Oxalate . 1 oz. 

Citric Acid 1 oz. 

I*h(Ksphorus 1 oz. 

Borax 1 oz. 

Turmeric \ oz. 

. . 50 grs. 

. . 1 oz. 

. . 5<)grs. 

iJallic Aci<l 50 grs. 



Pyrogallic Acid 



50 grs. 



CHEMICALS. 



XVll 



The quaDtities of materials required for the study of chemistry 
syntheticalbj will necessarily vary with thtj desires and tastes of the 
operator or according to the number and requirements of students 
working together, 

The materials that will be needed for the home-study of organic 
chemistry will vary with the requirements of the student. By the 
time he has qualified himself for a preliminary experimental course 
in that section of the science he umy trust largely to his own judg- 
ment as regards both materials and apparatus. 



CONTRACTIONS USED IN THIS MANUAL. 



B. P., British Pharmacopoeia. 

U. S. P., United States Pharma- 
copccia. 

C, Centigrade. 

Cc., Cubic centimetres. 



F., Fahrenheit. 

grm., Gramme. 

mm., Millimetre. 

T. S., Test solution, U. S. P. 

V. S., Volumetric solution, U. S.P. 



CONTENTS. 



PAGE 

Preface vii 

Advice TO Students xiii 

KisTs OF Apparatuh xiv 

List of Furniture of a Chemical Laboratory . . xv 

L18T OF Fluid Reagents xv 

Lists of »Solid Chemical ►Substancf^ for Study . . xvi 

Lntrodu(tion 17 

( f ENERAL Properties of the NoxN-Metallic Elements . 20 

Derivation of Names of Elements 37 

Numerical and Physical Matters 40 

The General Principles of Chemical Philosophy . 49 
The METALLrc Elements, their Official Prepara- 
tions and Tests: 
Salts of Potassium, Sodium, Ammonium, Lithium, 
Barium, Stnmtium, Calcium, Magnesium, Zinc, 
Manganese, Cobalt, Nickel, Aluminium, Iron, 
C*hromium, Arsenic, Antimony, Tin, Gold, Platinum, 
Copper, Mercury, Lead, Bismuth, Cadmium, Silver . 71 

Analytical Tables for the Metai^ 243 

jCoMMON Acid RADiCAiit, Official Acids, and Tests : 
Chlorides, Bromides, Iodides, Cyanides, Nitrates, Hypo- 
chlorites, Chlorates, Bromates, lodates, Acetates, 
Sulphides, Sulphites, Sulphates, Thiosulphates, Persul- 
phates, Carb<mates, Oxalates, Tartrates, ( .itratci*. Phos- 
phates, Borates, 251 

Salts of Rarer Acid Badicai><: 

Ben7X)ates, Cyanates, Formates, Hippurates, Ferroi-y- 
anideH, Ferricyanides, Fluorides, Hypophosphitt»s, 
Lactates, Malatos, Mec<mat<'s, Metiiphospliates, Ni- 
trites, Phosphites, Pyrophosphates, Silicates, Tannates 
and Gallates, Thiocyanates, Urates, Valerates, etc. . 821 

xix 



XX 



CONTEmS. 



PAGE 

Analytical Table for Acid Radicals 404 

Systematic Analysis 354 and 55(5 

Organic Chemistry 368 

Chemical Toxicology 559 

Examination ok Urine and Calculi 572 

Official Galenical Preparations 592 

Official Chemical Preparations 592 

Quantitative Measurements 593 

Quantitative Analysis : 

Introductory Remarks 609 

Volumetric Analysis 611 

Gravimetric Analysis 638 

Dialysis 680 

Appendix : 
The Elements, their Symbols, and Atomic 

Weights 682 

Index 686 



CHEMISTRY: 

GENERAL, MEDICAL, AND PHAilMACELITICAL 



INTRODITCTION.^ 

Man can Deither *Teatti luatttT m>r det>troy inaUer, hot he 
e&u permiineudy alter its character. All that is bunied m 
thus altertnl, anil nearly all that is eaten and dige^sted Is 
tbut* alt-ere<^I. Mao can iti muuy cwaes bring riboiit^ or in a 
measure contnd, tht^' pern itii unit altenitions which iimtter is 
capable of unde^r^oin;^; lunl in nil cas(\s he cnu investigiite (be 
ftlteratiou.H in matter whicli are ever |iroceedinjjj around him 
in anbnal, ve<^etahle, and minend nalnre. The Mudy «d' 
tbe4«e ttlteralioiis in all tlu^ir kn<iv\ n h^ngth. ami breadth, antl 
rleplh, 18 the «tndy of natural science, of which Chemistry- — 
the study of most r)f thtj alteratioos — is one of the moat com- 
prehensive branches 

The infinite vurietit^s of s?iulitb liqnid, and gaf^etmi* mutter 
of whicli our earth and almof^phere are compoi^Hl may be i¥t 
altered by man as to be re^dvid into a few liistinrt sul>Ht*Hn- 
cet^ appropriately termed Elements {EhmrHiuw, lirst or con- 
Mituent princi|:»le of anythintp), fbr by no known nicans can 
they \w further decomposed. More than stn^enty tjf these 
eU'tneutji have been proved Uy exi.st. 8<mje» 8uch as gohb tHX'ur 
naturally in the uncondiined j^tate ; bul the greater number 
are rortd)ined in so subtle a manner as to iNmceal them from 
<»niinary methods of oliservtition, Thnn none of the coiinnon 
pr<>pcrtie8 I if water imlicate that it is cons pi )scd of two ele^ 
niinrt.s Iwilh jkrast\s IhiI diflenn^ much from each other ; nor 
am the senses of si^dit, ton{*h, ami lasle, or other ortlinary 
oieaoa of exaiuiuation, lU^tect in (heir conx»ealmerit the three 
dtfnsimte i>f which i^u^^ar is wmpiseih The art by which 

' " iiHititr tills l><H(k ii< !i iiiiuti' III ff»nowiti^ cJieinistry pnicti' 

ail i\'xu\ tho lirst four cu^^rs, anil thtni < oiumt-^iicp work by |jre- 

p*r ^ J ^' u. All MtudvTitH ilioutd reud llie prt^fatory pagt^s. (fspecially 
Ui« piig« «»f '" Advic« to 8tud«ut8/' 

S IT 




18 INTMOBUCTION. 

these and all utlier c"oiy|Kiuijd substances ure re«3lve<l ititu 
their eleinents ii* termed the nri ofChvnustrv. a name derived 
(Kiwiibly t'riHii the Arabic vvuni liuaai, t^i ctinc'eal.' The arf 
of C -hen list ry id so iiieiudes tlie eoDstructiun of coujjmuiids 
frum elemetjl;*^ the deeuiupjsition of com^joundfc;, and the c^jd* 
version (jf tiubstaneeg of one ehu meter ioto others of different 
eharaeter. The tfcttm(*e of Cfienusiry deals with the g^enend 
prioeiple.s or lea din ji; truths rehilin^^ to the elenieutis, antl te 
the iiHinoer in whieb tJiey i^veiiilJy nnnhiiie ; with the obser< 
vation of the pheiiotneiiii whieh aeeonijtaiiy elieniieal eombi- 
uatioiKS interactioiLs nuil deeoni(Mif^itioD« ; ttiid with ihe de- 
scriptioQ ui tbe general |)ruperiies of the suhistauees prochieed 
during these cliangeH. 

From these tew words eoni-eruing the nut u re of the art and 
science of ebcini.stry, it will Ik' seeo tbat in niOi?t of the occu- 
pations that eniraj^^e the attention of man, Chemif^try plays m\ 
important jmrt — in tew more m than in the praetiee of the 
various depart»ient;« of Medirine, espeeiiilly the bratiehea 
ternied Thera|ieiitie8 * and rimrnmey.* 

Air, writer, food, drnt^^, jind ehemieal ^y balances — in j<hort. 
all material thinp? — are eoniiH^sed* an stated, of Elements, 
An intimate kuowled^e of tbe projiertii^ of the more imjior- 
taiit Element**, hith in tbe free for nneondiined ) and in the 
combined state^ an<l of tbe varionn suhstatieeJ* they form when 
they have eombined with eaeh other; tdl attainable knowledtte 

'Tin* jdt*a that euimuon metalrt crmtaoi<^<l vjihiAljle metals nmcealiMl 
Willi til ilicm wuii the one m>v.d from wbioh t.'lifiivical knowledi^'e niiiitily 
spmiig;. The men who eutie-4ivort'd to find ihu secret of sucli fonceal- 
meat Wf r*^ a|>propnatt!ly termini nlchrfnistfi. and their rlTorts were s[H}koii 
of its nhhrtfty \nl kimia, frtiiii icnmai. tu concfaJ). Their jiersiisti^nt lal>r»m. 
generutiou uftt^r generation, were nttKtJce*i«fiiI *i> far as the tninBtatitil- 
tton of baser metals into gold was concernerU, yet were invaltmhle ia ikw- 
terit J ; for new MnlKHtnuees were diseovereil ancl truths of niiturt* niiveiled : 
from the^ diseoverie*! further diMoverieH reKultni and thus grew th© 
still progTessing bnineh of knowledge called Cbcniihtrv. 

' TherapcDtics (ff«^jrevTt*<;*. thrrapeuHkn^i, from fitftawtvm, iherapeud, I 
Dnnte, S43rvet or cure) ia the bmnch of medidne which treats of the aji^ 
plication of remedies for disease,-*. The therapeutist iilso takes eogui- 
KUtire of hftfjintr — tbe dejwirt.nienl of niedieine whieh r«i*]H«eta the pr««er^ 
vatioQ of health— iiiid of dieMkn, the s^nhject of diet or food- By phar- 
maeofo^i/ iH niideratitod the narmal or physiolugieal action of drugs, as 
nnderiyine tlie therapeutic aclion. 

' Fhnnnaey /from ^iP#uo»^, phnt-mnl-mi a drug) is the frenerie tinme for 
the operattntiK of preparing or componndiog medicines, whether p**r* 
formed hy the Medical Trac tit ion i*r or by tbe Phnriiniceuticol Chemist or 
the Ohemist riT'-' l''""'iHt, It is also SH'unetinica nf '" -' ''^' »»-- f-Mrrr^^ 
)Kmding tenii o ihe aiwirtmetit in whieh ; -i 

ducted. Pkn i IB the i*tudy of the crude u . , mit* 

ftod auimftl kingdoms 




METALLIC ELEMENTS. 



19 



of the {M>wer or fonv (the I'heriiicul iorce or rheiiii<*ttl alfiuity) 
by whieh the element^ eoirtuiiietl io the n*iij|KiuiKlH nre held 
t<>l»'erher; and the ai)|diriitioa af *^y(4i krio\vh:Hl;.re to nmriiiaey 
and Medicine, luuHt he the ohjeetis i*<»y^ht tu lie iiUaiued by 
the student ofehemistry fur whom esjjeeiiilly ihw bmik hsis l>eeu 
writleu. 



The Elements. — Of the seventy or so ktujwn elenienttJ, the 
Ptndy of about forty i.* ei^Kemml for the proj>er e«nn|n"ehension 
of ehenustry. Fortunately for niedieal and phariiKH-eutk-al 
siudeut^ all these are of speeial niedieal or |diarniaceutieal 
interest, hence such student*^ while learrnn*^ the s<^ience iti^elf 
vna study its appli<*ution?* to metlieine and |»huriiiaey. Two* 
thirds of the forty are nvetals^, one-third non-ntetnlti. Tlie re- 
nmiuder of the eleinenl^ * are wldorn met with iJi Nnrure, or 
cK-^ur only in small fjuimtities ; and a niindier t»i' them have 
not received any praetieal application either in Metlieine, Art, 
or Manufacture, 

Before i njjinate ly i^tndyin^ the element's it is cle*iirahle to 
aerjuire H^nie general nohonn eoneerniny thein : sueh a proceVf- 
ure will als<> t*erve to intHMlnee the praetieal student to his 
ap|mrHtu8, and nntke Idm better nrquaintt^d with I he vari*ius< 
niethixl^ of inanipiilalion.^ 

Metallic Elements. — With rejL'ard to the metallic elemeiitti, 
it may wifely l»e aA^unied that the reader has* iiuHicient kiidwl- 
eil^e for present pur|H>8C«i; but little, tberefr)re, need he said 
rw*jn*etifig them at this sta^.'^e. He has an iilea of the aftjiear- 
aut^» relative weight, hardnesH, ete,» of such metallic ele- 
mentit ns gM, silver, eoi^jter, lend, tin, zinc, and iron. If he 
ha;^ not a similar kni»wledpe of niercyry, antiiruaiy, arsenic, 
plalinum. nickel, aluminiufli, ma^^neHimi, |MitasRinm, and 
fK^diuni, he shouhl einhraee the earlie>«?t opjiort unity of seeiirg 
and examining i^[>eeimen,«* of each of these metallic elements*. 

I I 11. t i^iillio found in ttie A|>|iejid}x, (>Vf al^* |*J'* '^* *'^'*' '^'* ) 

^ioii to npin^nitns nefMl tioi dt'itootjm^*' tlio TiMniKt*st i^tudcnt 
4*f ' wlui is III th<i j4*mi*i tiun* u (mpil \n medit'iiu' or plmr- 

luftcy. With the aid of a ft-w |iliinh. wincjijluHhis, nr otiar winatftr 
•In jilwuyH III hjiiidt liei may, tiy studying tin* folluwiri^ i«it;t'8, k*iirii 
If,,. .,i.....i,...i y. ,,,>;. ...^ ^i^icli lire (*urii«tiintly o<'< iirriiig ia tin' roiinst! tif 
u. inidrrKUnd tho pnKvsst.'* by w tilth utcdicinill 

j.r liacturrd, iiiid dr-tcct udultf rations, iniparitirs. nr 

i\i i>u!aj luri', Anjonir the ftwiwttiiiws iist'd in medi»'iini will \w 

f'. . »|| tht* chetnti'ul niatfriiits roqiiired. If, in addition, it 

d' ' ' I few feet of tflnsiJ tubing he pnx'ur«*d, many of 

il brd inuy hr formed. For fall UitA of upporntus 

»ii >. ftee the prefatory i)agc«. 




N0X-MP:TALLJC ELE.\fENTS. 



Non-MetaUic Elements. — With regard to tlie tioii-mettiHii" 
t'lemt'ULs it i.H lii-rc su|(]M>si!il tlint tht? stiniuiit huf^ ui» ji:ctieriil 
kiii*\vK"il^H*. lie slinuld f'oniiiieiKv hh stiiditv^ tberefWis by 
a aeries uf o|H*mtiuu« lU* toliuvvt^, on^UHu of lljeir uuiul)er, 

OXYGEN. 

}\ ^ Pt'rpnrafioti.—DsLY^t^n m tbe iiittt*t nbundant ekiiieiH in nature, 

foniiiim' (in n stiite ijf ecmibiiiitthiiij aUmt <»ne-lmll' c*]' tbe whole 
wi*i|i^ht iif our «flulj*\ To tibtiiin il lor ex]ti'rinuMJt:ii |>iirjio?*r** 
lilt Ibitt in iiecfs-^iry in to apftlv \wid to t'LTUiiii i^a^jly Uerniii[M.>t4- 
abU^ i'<iui|>oiiii(ls L'diitaiiiiiij.': uxygeij, whereupon the bitter is* 
evolveil in tbe ^juseous eouditiinr. There ari^ Hrvenil j^ubstHuees 
which readily yield oxyj^eri upnn heating, biit Ihr eryrttJilliin- salt 
kutAvu as pcttasHiuui ehbirat4' is^i [lerhaps l>et«t litted for tin/ exj»t*ri- 
uient. The »ize and ftirtn nl" thi* v«'i<s<1 iu wbieb t^ti bent ibe hhU 
will uiainly dr|H"ii(l on thiM|uantity of uxvjreu retjuired; but for the 
[►urpost's *if thr" Htudcnt the be?*t m a feM-tuhf^ an iustruuierit iu 
rnuHtant u^f in sttidyiu;^ praetieal eheniititry. It i.h siui|jly a lube 
oflhin ^liLs.s, a few inches iu len^jth, au<l hitlfor thri-c-^uarU'i^H of 
an int^i iu duHUrt4^r, elo^<»d by Iuhuui at awv end. Jt is ujade 
111' thin ^\\i>^, in fmler tlmt it may he rajiidly hcaterl or nwdt-tl 
without riHk *jt* (nu-ture, (Set- jiieture?^ tjf toHt-tuW'^ \n Figs. 8 
juid 4.) 

Outline of the Process. — Heat |K>tn«8iiiiii cblomte, PoUi^di 
rhlorm, V. H. 1*., (suy. ajs inueh n>* will lie ou ii twenty-five 
cent piett* in a test-tube held in tbe Haiiie otVa Hiujf^eii luiruer 
or spirit buup. The .'^nit first fiise-M — t.r», li(jyefie.«« — tiud Ibrm.s 
a eolorlesrt lif|*iid; and on further heating'" lbi?< lii[iiid, *:a^eoUH 
oxygen is fjiiiekly evolviMl, Before Hpplyin^' beat, however. 
provif^iou tihould fa^ nunle for eolkM'tiu^' ibe^'-ai?. 

Collection of Gases {Sfe m V'xyi. 3 ).— Proeure a piece of j;hi«f* 
tuluii"; i\Ui\\{ the tbiekne^H fd' tttjuill jk^h, am! t\ ftw^t or eigh- 
teen inebns bui^, au*l fit it U\ tbe te,Mt-tulH* by merttit* of a 
eork, ( Ivouj^'er tubes omy be neatly eiil U\ any sisu^ by 
smartly drasvtug the e<]Lre of a triau^rulnr 61e a<'r<»s^ tbe fflass 
at the re*juired point, tben elanping tbe tube» the i^erateb 1m^ 
in^ l>etween the bauds, and pulling tbe iMirtious asunder, tbe 
pull beiiitf exerted iw if to i»pen out tbe era* k wbb^h tbe file 
\\m oouinienc*ed») The tube h fixed in tbe t-ork thnui>fh a 
n>uuil hole made by the aid of a refldiot wire, or, better, by 
a rat-tail file, or, liej<t of all. by oue of a ik*t of eork-Uirers — 
pieces* of hra^M tuluoi^ of different diameters* sbariK^neii at 
oue eud and liaviug a flat head at the othen The cork aud 





OXYGEN. 



21 



test-tube must \^e fitted to eiicli other aeeiirately find closely, 
but aot 80 ti;^'hLly lis to Ureak tli« tuHt-tiihe. Tht^ long |iicH*e 
of tiibitig tihoiild be heiit t^) the most coiiveuieiit j*luipe tor de- 
li veriug the ga.s. 

To Bend Glass Tubes. — llohi the purt of the tiiho re<[yired 
to \ye In^Dt in iiny gas- or i^pirit-fiuiiiie (a hsh-tale gtLs-jet, for 
example, Fi^* 1 ), cotistmitly rolatitigil, ho that li bout an itu-h 




Hortcniug mid iR'ndliig Bluis& taboi. 



1 II*. 2. 



of the glaRS beeoTnej? heate<l. It will t^MMi J>egin to soften, and 
by the (jthtle [jre^sure of the Hjigers, it eiiii then be made to 
HSKiime any reijuired angle. In tlie present ea.^e, tlie tube 
iihould 1k» heated at ubotii fVair inehe.s fr«)iii tlie extremity 
|o which the cork i.s attaelteil, nnd iienl to an angle of JM) 
degrees (Fig. 2). A similar bend may he nnule near the other 
end, and the s^hort pieee i)f straight tubing should then be 
etit oil'. The eut ends shfmhl tiiially 
l»e nmiideil off liy holding tliein iu 
the Ha me until tlie gla,«?* softens. The 
finished tnln* biLs the sha)>e nhown in 
Fig. 3. 

Fit the t^ork mid bent tulte into 
ibe le<it-tul>e ; the apparatus will tlier» | 
he ready for delivering giis at a eon- 
venient dii«tanee from I he heated |wir- 
(idii of the arrangement. To eollei^t 
the oxygen, have ready three or fVmr 
leftist ub«^«^ (orwnall wide-mouthetl bot- 
tles i quite fille<i with water, and in- 
verte*! in a ba^^in or other vesweb alfto 
^lUainifjg water, taking eare to keep 
the mouths of the filled tubes a little 
behtw the surface-. Now apply heat 
In the ehlornfe eontained in the test- 
ttibe, ami w» arrange the tipen end of 
llii* bent tulie under the water that the gas which pre-sently 

iipcg with erterveiseence from the melted cidorate ma}? 







NON-MET A LLIC ELEMENTS. 



pass out i'nun the free end of the tube, anil nmy biibhle 
m\i\ and jrm4iially till tl^e j)reviniistly water-filled inverted 
te:*t-tubei*» The first tube fill may l)e rejeete*!, sie it probiibly 
coDsists of little more thau the air which waa originally in 



*\U'*h 'v; ' •• >5 i& *W * "e '^ *% '1* 'Is -te * m 



i 



immuutiiuu 




■Mil ■ \ 

of n prr! 

Ill n t, »,i luh, 1.1, ). Jii-,' jii , 
an' fiiptNmnli for ii|»)KrirMi < 






;:/;;.. 



.lt)r> fcnlHUatlg U'xtlllg Jf^ii 



oxroBN. 



23 



I 



the nppjiratui^ and \\m \wen displaced hy the oxygen. That 
which ctmieK atterwards will l>e |jmctically pure oxygen, 

A>* each tul>e or hottle becomes fulli chme itt* mouth (still 
under the surface of the water) by a cork aod theu set it 
iy*jde; or in^^tead of a curk a little cup (such as a porcelain, 
crucible or small ^•■allijM^t ) may be brought under itsj mouth, 
and the cup, with the mouth of the tube m lU l>e lifletl out 
of the water and plaee<i ai^tde until wanted, the watt^r ri'uuitn- 
ing in the cup effectually preventiug thegiu* from escaping. 

On thr fnrge Mrnit\ oxygen intty he [>r(.'jNtrrd in rhi' sjiiuf wjiy, 

larger ve*«eb (ghisH fliisk« or irnn Iwjttles) liein^i; uiiiplityed. 1 1' 

ih^' {HitUMiHtuni rhhirale be previously mixed witli about :u; eiimii 

weight of coirimou bbuk tuangimeHe iixi«l!% thi- nxygt-ri will W 

iven nff nl a ronjiidmilily lower teni|MM'atun\ 

Oxygen, when required in it very pure t<tiit<3 for meditintil pur- 
~>o8e.^, might he jirepared by adding water, in ^rnall HUeee^sive 
qujintitie^, to u mixture of sAOilinm peroxide ami sand ; hut the 
high dQ^TC:^ of |>urity attainetl Tn the cMinmerciul prepaniti«m of 
oxygen fmni the atmosphere (by a uu^llidd that will l>e deHt'riljed 
later) by manufaeturerd who 8Uj>i»ly the ^j^ii-s o«>iupress4'<l in jsteel 
cylinderH, rem I ers this oxygen stiitable for all such purposos. 

yt^if. OH the (hif*Tfhin and Sfhrage of (ra»fi>. — A nunit>er af 
^»i«e>*, whether prepared for experiment!il pur[)am?s nr f»u the larjjje 
iW'.ale, may be collerted and st4»red in Ye^wt^ln inverted in water in 
the manner just deHcribeil for oxygtjn. The eoal-pis (generated 
at ii^aw- works* by ntrongly heating coal in irem retorts, very much 
the shape f»f te?*t-tuhea, rmly iis many feet hmp ha a tent ttilie is 
inchLi*) iM Ht4>reil in the well-knowu iron ^iis-luiMers whieh may he 
regartletl iw jilaying the part of the inverted te.Kt-tuh<;^ or bottles in 
the oxygen experiment It is [dain that enJleetiun mid storage 
over water w only praetieahle in the case of pises whieh df» not 
diesidve to more than a snudl extent in water* Co:il-t*jis ami 
<»ther prases bes^idetn oxygen uiay be stored in steel cylinders uuder 
high prefwure. 

Sfiinbilittj of Gfiftes in Wftfer. — All gases are more or less 
•(oinble in water The ipuuilily of any gas whirh dis^solves de* 
pf*nd9 Upt>n the teinpenture— <'oIil water diasi»Iviu^' more than 
hot— anci upon the prepare, Wliatever the qnautity of a gas 
di!»«iilviHl by a li*pn<l at onJituiry almospherie pret*sure, double that 
qiuiatity is diAiiUilved at ilouble the ftressure, treble thtU ipmntity 
ait triable prenHiire, and so on. This is a general law (Henrs- and 
Ilaltf>n) regiirding the solubility of gjt4M?» in liijnitl* at eon»*tant 
ten* I »e rat u res. 

Proimrtiee* — Free oxygen is a colorlesn, iKlorless, and tiuite- 
liwe giin, ( 'ailletet and Pictet eueeiH*de<l in lifpicfying it on a 




24 



NON-METALLIC ELEMENTS. 



^^inftll scale^ aud Wroblews*ki obtained it in larger quantity as 
i\ tniiii<[)iiretit ilujd, cl«»8ely rt^*^ml>liog water iti a[)i>eiimnce, 
but 8li;ihtly bluer ; Dewar bus uow liqucfitKl it iu Irirge quan- 
tities, ami ha.s aliio olitained it iu the mVul rouditiou. Obvi* 
ou^ly oxygen is ut>t very si>lulile in water, or it nudtl not be 
t'olleetefl l>y tbe aid of tbat lic^yid. It m H>lyble, however, t<» 
a eertaiu exteut, almut '*i vohuneis dis8olvtU|^r in 101) of water 
at ordiiuiry teunMrTatures. When any ordinary s^auijile ol'eis- 
lern or river water is heated, or wubjt^eted t<* *:reatly redneeil 
pressure, luimerous small bubbles* of gas, rontaining a eonsid- 
erable pi;ojKU'tio[i i*f oxygen, gradually es<*ajK* from it, Tbe 
jjresenie of dis.'^alvei! oxygen in river and sea water is ei-^sen- 
tial for tiie res|iiration of lislie8. 

To *ibs<^rve the relation of oxygen to eondiustion, renicjve 
one of the tube.s from the water, by plaeing tbe thnndi over 
its mouth, and a]>j4y for a st^'ond a lighted wood match to the 
orifiiv ; the gtL*i will l>e found t*) be ineond>ustible. Extin- 
guish tbe flame of the niateli* and then t|niekly introduee tbt^ 
etill ineandeseent earboiu/A'd extreniitv of the w<n«l svell in- 
side the test-tube ; the wt>od will at ouee burst iutt» tlame» 
owing to the extreme violeiiee witli whirli oxygen su|iiM»rtft e(»m- 
btjstii»n. These tests of the [irei^-nre of free oxygen may also be 
applied at the extremity f if the deb very-tube whilst tbe gaj* \h 
iKring evi*lveii. ( [t is desirable to retain twtj ttilje*^ of the gas 
for u*«e in subsequent ex]>erinients ; also one tube in which 
only one-third of the wat«*r ha» bt^en iii«plaee<i by oxygen. ) 

Rfhtdon of Ojifijt^n fo Auhnttl nnJ Vrtjrhthit' Lift', — N«it tally 
tlie earhon at the vwtl of a piei-e nf l- barred w<tfnl, but any »aher 
sahstioice that will burn in siir (which, as will l>e H4L'eu preMt?nlly, 
in ilibited oxy^^ea) will hum iin»re brilliaatly in pure oxygen. 
The warnitli of the l»o<tjei* of animals is kept np by the continuous 
bnrni!i«r of the tissut^s m the oxygen of the jur, drawn int4> the 
Bysteui through the kmg>«. The product of tliin combustion is 
exhaled into the air iu* a ga^ou?< eompouud of carlwia and oxygen 
terauHl earbonie imhydride, a j^as which, in stnili«:ht, is absorhefl 
by and decomposed ia the cells of plants with fixation of earl»on 
and blK^ratioa uf the *»xygca. Thus, too, i?n the atmosphere kept 
constant in coaipOHition, 

MeriioranriftitL — At present it is not advif*4ible thnt the reader 
should trouble himself witli the consirlcraiion of the i^bemieaJ 
action which occurs eitht^r in the elimination of oxygen frf>m 
ttn comfwunds, or iu the s<'piiratiori of any (>f the following non- 
metallic eleuu'nts t'roni tticir ctanbiruvtions. ft is to the pn>pertieji 
of these elements themselves, especially in their free, or unconi'- 




BYDROOEX 



25 



hine<l, t'fuidition, that be should jit prtJ^en! restrict hi;* iittcntion. 
Working thuH from .•^imph' to more ciinijdi^x fjk'ti^, he will in tliir 
lime Htid that the r^mipreliefision 4if stich autitins a« oceur in the 
|*re|>aratjuu of tiie.se lew elomente will be easier tlian if he 
atteiiipteU their lull study now. 



^ 



HYBROGEK. 

Preparation and Collection. — The element Hydrogen, in 
tb«i unnnnhined stitle, Irt iilso a g«sJ It is al>taioahle frow its 
conimoneiit ronijKHjnd, water (of whicli about one-ninth hy 
weight 18 by<lro*;i'n ), hy the ugei)ey of liot /Jnr or iron, l»jt 
more runvenieritly l>v the aetion of either of ibeM- nietuirt on 
eold diftite »4ul[ihuric oeid. The aiiiJiiratn^ ut^ed for making' 
oxy;^^en may be emjiloyed fi^r ibis experirneiil ; hut nn lanij^ 
is required. Phice i*everui piece** of thin zinc^ in the geiier- 
ating tulje rFitr. 4), or iu a eominon ^la.sj* iHtttle (Fig. 5), t^r 
fla*<k, and cover then» with water. The coll€*eting-lohe.s 
(the!«e alinTmay be wide-mouthed bcittles) being ready, add 
cH*iieentrate^l tiulphuric aeid (oil of vkrol ) (o the zinc and 
water, in the pro[K»rtion of alx^ut 1 volume of aeid to 5 of 
water, antl fit on the delivery-tube; or pour the add down 

^ Undisini obtAinpc! uUm-^ of hydro;;*'H with palludumi and oihvv mvUih 
rotii|M)utu1» in whirh Pt^verul 1iumlr«*ii times itj* bulk nf gas is retained 
hy thf incfal in ruruo or even at ft red heat. This was ri'jcarded as phys- 
i« ' I (lion of iht> opiiiioiii hinp h<?Ul by <:hL^miftts» that lijdro|?»Hii is 

>t _ \n\, (vralutm tt'iiiK'^rt it hifdrtiijntfHw. iiiht'T rhrimM><htjfh-hfm, 

ftii.. .^. , .irtd itrt n*la!ivi" weJMlit in the nilid ^tute tii b<- injirly tUnt- 
fcorlhs that of wati*r. niszow^iki rla lined t*« biivi' lk|ij(Hf-d hydrnj^eii in 
IftSK'i, It htiA been 1i<|ni'fifMl by Jb^wtir, who find^ it<) rritiesil t4*iniH^ratnr« 
(i. r., the teia|ienitijrt' tu wbieh it nui^t Im» roaled befon- it jji imwiblr to 
convert it into Ih** lifjuid slate by the applieati«n uf any |trr*<Hnre, how- 
ever itmM) to Iw }ippr*iximul«ly— 2ii3''^ C. and its b<jihti|L: ixtiiit — 'iiri'^ (u 

StttiutH^ — More tiisiit thirty j'fijM ago, Fmnklanc! and Ij*»c'kyer* to at*- 
rotirit for a errtnin y*lbm line in the solar Hpeetrnru, aKsuoied Ibe exist- 
met? of X JM'|H*nile ebinn*nt whieb tbey termed helium. In iftJt5 Ramfiay 
found a new elenn nt in tbe mineral cltAvite sriving an i}£tiitimi n yellow 
liur 111 the np<'rtmni, |»roh:ih!y idenf ica,! witb that juM alluded t^o. To 
tliU uvw tern'?*trial «dement he pivi> the name helium. Ram«<ay. CVdlie. 
and TraverN afierwartls fotuid biliuni in nitmy minenils, often aecnm- 
|Mifilr>d by hydrogen, tbotigh it seem s rather to liave anal oKi'-** with ar^on, 
another ronj|ttinitively reeeutly dis4H>vered flement whieh will l>e re- 
ft f ' " ' lilrojfen. Many mineni Is yield gikneji wbeti heated, and 
r in cavities, 

^ is rirnmttntfri zinc prt^ji^ired hy beating zinc in an iron 
1a*llr ovrr a iiri% and immediately the metal is fnsed. ponnne it in a nIow 
stream int** a pail of water from a hrifrht «if H or 10 frtjt, Karb drop of 
aitie thu(* yir'bls a thin little Ih^I, whieh^ frtr its weiirbt. presi nl.s a large 
aurfarf to the aetioii ofllii a<id liquid. If the melted zine heeumes too 
Hot. tbe little bella will not he formed. A trace of iron in the zinc greatly 
incnoiM^ii the rate at whieh the hydroj^en }a eyaJved. 




NON METALLIC ELEMENTS. 



surb a fuDU€l4ybe ' as i& rIuwii in Fig. h : the hydrogen at 
oiic't^ i^Hraji^s with edervestH^nct^ Ihnii the fluid. Having re- 
jectetl ihe first j>i>rtiuati (or Ijaviug vvidtuJ until the air orig- 



Fia, 4. 



Fig. 5. 




PrepAmtion f»f hydrogen. 

inally m the bottle may l>e considered to be all expelled), 
rollect four or five tul>es of the ^as in the aiiiimcr described 
under oxygen. 

NoU'9. — In making larger quaatities, bottles of ii|iprc« prints t^izc 
may be cm ployed. Other Tnetalw, notnhly potiLssiom imd siHlinni, 
lihtTatf hydrn-^en the moment tbey rome into cuntiiet with wntfr; 
bnt the proeenHc*^ are not econnmiejd, and the Jicliun m danger- 
ously violent. 

Properties. — ^Hydrn^en, like oxyg-en, is eolorleiftH, odorle«y^ 
atid tasteleiiH, If iron In* used ui orenerate ihe p'as, it has a 
marked smell; but this is due to impurities derived from the 
iron. 

Apply a flame to the mouth of the delivery*tnbe, bnt not 
until it in plain llmt the hri.^k efferveseenee of hydnigen rnuMt 
baverenulti'd in the drivint' out of all air from the generatin;,^ 
tube ur bnltle, /or ihf intjrhtrf of hijfhofjeii and air mail e.rpfoftr^ 
Ignitita* of ihe by<ln)gen ensues showing that» unlike oxygen, 
it 18 eombustible^ * ^^ 

rinnge a light«?d mateh well into a tube (or wide-mouthoil 
bc^ttle) exmtnining free hydrogen; the ga» is iguiled, bnl the 
niateh be<'onie8 extiiiguif»he(L This .shows' that bydn:)ijen is 
not a sup[M)rter of ordinary eondiuMion. 

' Kimii<?l-ttib<9*? mny ht* piirolui^d of thf* )V)i|H>nitUN-in}ik<^r ; or, if the 
ptiiiil liAs iuT4.i«1<» » UiliUt liKkwpifM\ jiiul thr advitiit«g« of n tuti^tf i" di- 
rect bi9 opemtioiifl, thc^ amy be xnade \ry h\msu\f. 





HYDROGEN, 



27 



Hydrugt^ri in Imrning iniite^ with the oxygen of the air 
and tV>rnig water, which may \w. conilensed on ti cool glass or 
other surface. Prove this by holding a glass vessel a few 
inches alK>ve a hydrogen-tlanie. In l)uraing the hydrogen 
ttmtaiueil \n one of the liihej^ or hi>ttk\s, the Hume m best t^een 
when the tulie is held mouth iipwanl, and water jMjured in 
\ JUS t*> ex|jel the gas gratlualiy. 

If, iu:^tea<l of thii* gradiial e^Hiihinatiou of the two eleiuenis 
oxygen and hydrogen, they l>e inixeil together in the right 
proj>ortionjs and then ignited, they will rapidly eoruhiue, mid 
explosion will re*siilt. Prejmre a mixture of this kimi hy 
fining up With hydrogen a t4:'^4iihe fronj whieb one-third of 
the water has already Ixxn ex[X"Iled hy oxygen. Keniove 
the tuf>e from the water, plaeing a linger over it.H mouth, and 
having a lighte<l luateh ready, ap|)Iy the tlame; exph^siou 
ensne^s, owing to the itistantaueou.s eomhination of the whole 
bulk of the tsvu elemeuts, and the ex|MiU!*ive furee of the 
highly heiited steam produced. If anything hirger than a 
ieet-tulH? is employed in thi« experiment, it sboidd be an 
iratal water bottle^ or f^>me sueh vessel ecjufllly strong. 

Notes, — ^Tliese gases thus unite at a temperature far higher than 
that of hoiHng water, two vrtlumes iif hydrogen and <ine of oxy- 
gen yieiding two of pa^^*ous water (steam). 

Thf nfiUe of *urk rxplfmonji m iiuised by roncussion between the 
niddrtdy expanded gaseous Imdy nni\ tht* air. 

Thr force of the fxph*ioH, or, in nther words, the pressure of 
the suddenly heated and therefore suddenly expamled stenm, is 
Im'Iow that neeessary to lireak the test-tnl>e. Some pressure, 
however, is exerted; and henee the necessity of the preennti^iu 
previous*!? suggested, of allow! np^ all the air whieh may hv in a 
liydr<igeii-apparatus X*} es<^aiM* before proceedini^ with the experi- 
meals. If a flarne he applii^l to the delivery-tulie lieforr all the 
nir is exj)elled, the protmlilf result will be i^'intion of the mixture 
of hydn»gen iind <ixygen (of the \\\x) anrj ronsequent explnsi^m. 
Hut evfn in this c'as<! the geaeratintr vessel is nut «il1en trarhir»"<l 
ttnlem it be hir^re and of tJiin glass, thr ordinary elfect beinjr tbat 
the eork i» blown out, imd the drlivtry-iulH* bmken on falling to 
ground. 

Hydrogen im ;i cnnstituent of all the subMiiinces burned for pro- 
Ueing urtifirial b^dit* wuch :LHsolifl fats, oil^ and eoal-gas. The 
rxplojiive force of Inrgi' <|Uautitii*H, siub a« a roomful, irf enrtl-pis 
and air is well kufuvn to ^iitlire for blow in jr out that side of Uie 
n>4itti whieh offerf* h^nnt n'sistanee. 

The fifinpo^UioH <ij water vm\ W f»rc>vcd iinalyticany as well oa 



28 



NON-METALLW ELEMENTS. 



sytithetically, by passing a currfot of electridty through dilute 
Hiilj»hnnf iifid (electrolywit*^ fmuj ?'<*\ lutt, I Itiost, or I dcriuii- 
jM»s4 ). I>unng the [>iijiHiigi* uf tlu' turrcnt, hydrojrt>n aiid oxyj^en 
aru lilxTut^ m the }>n>p<»rlicmg in which they nre present in 
water, twiee iAs niueh hydn^gen h,h nxy^^'ti, by volume, being 
jinHhuHd. Tlie quantity ^d* nulphdne acitl reiriHins the siime irt 
the end lis at the hejiiniiiiijET f>f tiu' experiment, the ipiantily ni 
wattT havinir nhme fliminiKhed, 

rti,\fBiTKTt<iN (friim m//i/>i/r<^, 1 burn). — The exjierimenb* with 
bytlro^reii and uxyi^'eii illiistniti' the true ehu meter of e»niibu>ttion. 
\\'lRMiever eheinieal eoinbinatinii is KiHlieiently inteiiH*' to l>e ae- 
etHJipanJed by heat and It^ht, the uititeriids are siiid to iindei^ro 
efUiihustMrn. ('oinliiisti*iii *>nly <*erurrt at the line of (Hiiiljtrt 
of the etinibining botlie.s; a jet ot* oxypen will burn in an 
atnlf*^^(^he^e of liydro^en quite m^ eiinily as a jet of hydmgen in 
oxyjreti. A jet of air (diluted nxygen) will burn an readily in a 
jar of e*Ml-pu* UM a jet of eoal-piw Imrns in air; eaeh is eond>U!*- 
tible, eaeli ,^npports the eoinhiistion »»(' the other. Henee the 
tenuH iytmhuniihir and xnjtporfrr (>/ lytfttlftt^tfion are merely eonveu- 
tional, and <»nly applicable ho lon^ uh the rireuinManees uhdiT 
wbieh tbey are ap}died remain the if^aine. In the eaj*e of sidi- 
stanees burning? in air, the eonditi(»n8 ar<% jiraetieally, always 
the same; henee ao eon fusion ari^e*^ from repifdin^ air m^ the 
great supjiorter of couibuHtion, and bodies whieh burn in it as 
being couibu*^tible. 

Kio. G. Fio. 7. 




Blmctnrp of cntnlle-fiaino. "BuoiCii/' Of ilr-BM» Ininier, 

Sfntrfurr of Ffamr.^ \ eaiidle-flame (Fig, H) or oibflame is 
eimipOfH»d of intensely heated material ; the central portion is un- 
humt gjM*, the iiejtt envelof>e is formed of partially Inirnt and 
very dense g^itiWNms and 'nilid partieb^s sufneiently hiirhly heaU>d 
to give light, and the onter eone of completely burnt ^i\m^. In 
thc< figure the iihitqme«& of limit of tbest:! cancft is purposely 




EYDROOEN. 



29 



I 



Hfimewhat exaggoratefl. Air nuiele by any iiipeliiiuitiil loiiEri- 
viiiicfi t4» mix witli (Iif ^sih in tln' iiili nnr of it llame iit oiu e Imrtis 
Uf», or [K^rbajis jtri'vi^iit?* tlie fnnnatioji ol* tlciirtt' fi^asi^s; jyTiving" ii 
hi»tt*T, l>iit utin-liiiinjioiiji jtt. The air-pL^ lainjM (Fig. 7), <ir 
•iliins4;ri" jrjis-l»unK"i><, ruinm<iiily Uf*i.^<l in i beiiiical Jatj<iraiorH\s, 
art' eoiiHtmcte<l on tlii.'< }»rijjdpk'; lluir ttariH' !iuh UiiMiddilioaal 
jidvaiitfi^i* of nut yiflditi^ a rleposit iif soot. 

Ill iht* air-i!;as lnirULT i'oal->cas t^ca^nii;; from a Hiiiall oritiro at 
the Uittoiii of I be upn^^ht lube draws in and aiixes witb ratber 
mure thnn twiiv iU vidoai*' of air (.^n[*|dinj tlitonKli adjao-nt 
holes). Tbii mixturi*, wben kindb"*!^ snAy burns iil tbe end of tb<' 
iiprij^ht tulx-, and nut within it, partly I>er3inse the nn^bil of the 
hnrner, liy eondnetin^ beat away, e<n>ls tht; niixtnre below the 
tetnpenitiire at wbieb it can ignite; partly because the veb)eity 
with which the mixture flows out is greater than ttie rate at whieb 
HUeh a mixture iirnit-es: and partly because the pro[Hirtion uf air 
to jrus ill the mixture in iusutlieient tor [)erfeet eimibnstion, the 
external air immediately surronndirig the flauie routnbutinLr m;i- 
t«?rially tr» the eompJete enirdaistioa of the pis. In the Dnttj 
pa^rtij'lmnp advantage is taken i*f tln' ra]iidity with wliieh a sur- 
"Bire of wire piuze eonduets jiway beat; a wire-j^:aU7.e eii^e sur- 
rounds an oil-flame; an inflEiuinialde mixture of pis (fire-(hunp) 
and air eau pjLss ttimutfb tin; pinze and burn inside j but the 
Haine cannot, ordinarily, be i-ominunirat^^d U* tlu^ mixture <ui(- 
Kide, lufuuse tlic metal id' the piuze and of the other jiarts eools 
down tbo gaH below the U'int>tTature at which combustion can 
continue. 

Propertiee of Hydrogen (contiEued). — (Jiii«i<HJs Iiydroiren 
is the light4eLst wub«tanre known. It is used tor hlHiiL' lail- 
IcMJiis, hut hiis l>een, to some f*xtent, sujwrseded by eoal-pin 
be<'«use i'oiil-pij<, thou;j:h ttot s<* liglu, is eheaf»^r nnd more 
eaniiy obtained. The lightness of bytlrogen niay lie rendered 
^•videut by the tol lowing experinieat: — Fill I wo test-tuln^s 
with the L([us, iind bold otie with its rnoutli downwards mid 
the other with its mouth U|jwar<l. The hydrogen will have 
esrnjM'd from the bitter in a few 8t-eonds, whoreius the former 
will still eontnin lhi» ^ius at\er the lapse of many secomla. 
Thin may Ix' prt)ve4 by aiiplying a lightetl tuatch to the 
mouths of the tubes. 



Tht rfiatlvr weight or sjieeifie gravity of oxygen is nearly »ix- 
tren timi^M that of hydnjtren, A vt's,H*d boldinjr one ^rain «d' by- 
dro|^'en will hold nearly >,ixl4*eu )f rains of oxygen. The rebition 
of the wei^rht of bydro)(en to air is iis I to 14.44, or as O,0tI9Ji to 
l,f>. One grain of hydrogen by weight measures alMiut 27 fluid 



\ 




30 NON'METALLW ELEMENTS, 

ounces, and, therefore w<»ul(] u\>*mt fill ii ruiunnHj \vine-lM*ttle. 
Hiieli ik Itottle would, at onlinary IrnqnTaturcs Hohj iilKml I4J 
^Hiiris (tf air, i»r idwujt lii ju'raiiis (if oxygen, 

Mtmurfutdnm.^-\i is flt^si^al>le tt> retjim \\\u tnin'}< uf hydrogen 
for M^Q in t^nijsiequent t xiK*ri 1111*11 te. 

Diffl'shjN \}F (tAme^s. — Hydru|?en etmnot be kept in wuth ves- 
sels a» ilje inverk'd tej^t*tube of the aliove exjseriiiu nt ; for, though 
mut'h lighter tliiin air, it dtffune^ d<i\vnwiiril into the air, while thi* 
air, though miieh heavier, ditfiL^es upward into the hydrogen. 
This' power itf diffuaiofi is poHsen^'M^d f>y all ga**i'?*. The rates **f dif- 
fusion *d" the dirt'erent gii^^es are inversely projxirtional to the 
wjuare roots <jf the densities of the ga*ei* {Grahirmj, Thus hydni' 
gen dirt'ufies four times faster thfui oxygen. The great imd im|>or- 
tjyit proj>erty of dirtUsinn syggcsU that tlie partieles uf ga.«*4:*8 tire 
alvvayn moviug, never at rest ; [low otherwise eoufd gitse-s ditlhi*** 
into each other iis they do, notwithstanding the r»p[ic»Ming influ- 
cnre of gravitatifni? Diifusir»u strongly sn[>[mrts this (Clausius'i?) 
kinetie (am/u, l-inri), I move, 4jr put in jnution) tlieory of the 
physiual eondilioii of gtuses. 

PHOSPHORUS. 

Apprftrnfict' find /<i)urrr, — Phosphorus {f*hmpftorttM^ V. K P.) 
is a solid elenient^ in ajipearnnee jind rousistenee resenildiug 
white wax ; hut it gradually heconjes yellow hy exposure lo light. 
It is :) ( oiistant eonsttlnerit of honc^, iuid may he j*ri'pared from 
them hy a proi-ess which will be desenlied f^uhseijuentfv. 

ihtdion. — Phosphorus, on aeeount of it« great alhnity for oxy- 
gen, bikes fire very reiidily in the uir, and shoulcl therefore be 
kept under water. When wanted for use, il ninsl he eut under 
wiiter. It is employed in ti(*ping lueifers though rrd or amor' 
phftm phoHphtfnis is less objectiojial^le ftir this purpose. 

Experiment. — Dry a piece td' orditniry pho^jihnrus, nbout 
the i*ize of i\ fvea, by cpiiekly and earefitlly pressing it lM?twec*n 
the tbhls of (»orou!^ (filter or hlotting ) paper; phiee it on n 
phite, and Ignite it hy tonehiug it with a jdere of warm wire 
or wood. The product of condniiitiou is ti ilensie white >utf(>- 
oating smoke, which myst Im? eonfinefl at once by phicing an 
inverted tumbler* or beaker, or other Hiinilar venwel over the 
phoHfdmruK The fumes rapirlly aggregate, and fall in white 
ihikes on the plate. When thii* has taken phice, am! the 
pho8phorii8 in no longer fjtiming, taoiHten the ]Kjwdcr with a 
drop or two id^ water, and ob?5erve that j*ome (d' the water h 
converted into ^tejiiu, an et!t*ct due to the inten.se athnity with 
which another pension *»f the water aud the jjowtler have com- 
bined, with the Involution of fieat. 



1^ 



NITROGEN. 



31 



UthhhI ]4ius|»hijn(' iuitiyitrifle ; tlie i-ojiilnTiatinii ol'tlu* latUT with 
Ui«* cIciiieiiM of Wiik^r pnaluti'?! a vurk*ty of pliuspljorii' iu-nI which 
ilis4^cilvi'4« in Ibf wakT ari<l forrj*K, iHi f^turi<liii^, ii iliUite Holutinn cif 
cjrdiniiry phonpliorie twuh The I>iluttMl J*hos|jfi<irk- Arid of llu* 
PhamiHrof»n*iii i« a similar Hfiliitinn, made in a somewhat differt^nt 
Wiiy, ami <»f definit*.* Htren^th. 

OTTEOGEN. 

Source. — The chief ftouiTc or this gaseous t-lemeut is the 
at»i\ij(8pbere, uearly four-liiUi« of wldrh emisbta of nitrogen 
(whibt rouj^^hly one-fiith is oxygen). 

Preparation. — Jiurn a |iiere of «lry phi^sphoryp, the size of 
w jKut, in a eorifiiud |H>rtion of air* The oxy^^eji \^ thus re- 
iijove^l^ and the nitnigeu remains. The readiest mode of jier- 
fonriing ihiiJ ex(>erijnent h to tix a piece of earthenware (the 
lid of a small |Kir**ehiin crucible answers very well J on a ihiti 
fdeee of cork, m that it nmy floMt in a dish of water ( Fijf, H). 
Phu'e the dry phosphorus on the lid, itjnite with a warm rod, 
and then invert a tumbler, or any gbis< vesst 1 of alioiit i\ half- 
[iinl mpatnty, over the hurniiTir phosjihorus, so that the montfi 
tjf the ^h\^ nmy «lip into thi* water. Ijt4 the arnin<^rement 
rent fnr a whort time, tor the flakes of phosfdioric anhydride to 
Hul^ide ami diswdvc in the water, and then decani the iras into 
tc»t-tubeii as iudieated in Fig. 9, u.^ing a tnh or other vessel of 

Fjo, 8, Fio. \K 





t^ri'lMimiion of nUrogi^n. 



DecAiitatlon <>f gase*. 



ffiiftieient depth to achnii of the ^la«ii coataining the nitro^n 
lH*tng turneil on one nitle without air gaining acei'ss. 

Larger rpnintitlen of aitrojiren may he ohtained in tho same way. 
< uh't comliUKiibles, a« sulphur or a candle, might be iii*ed U> burn 



32 NON-METALLIC ICLEMENTS, 

(*ut die (ixygeii ga*i fnjuj the alr» but iimie answer ho quit-kly ao 
ciimpk^tely as iihosphnruw, tnWeci to whieh, the jiroflurti lA' thd 
t!iimbiif^lioii wuiihl iiftt alwav!* be diKMilvetl by water, but wuidil it 
main nuxcnl wilh ihr tiitni^en. 

}kmornndum. — The statement efineerning the eomptJ!»itiou < 
the air is rtmghly eontirnied in bMihitin^ nitro^j^en^ abi>ut one-hfl 
of the voliiJiie of tliu air originally in the ^hiKs ves-sel havin 
(li?ia(tpt'iin'd, itn jiliit-e being »n.'ai[>ied by water. 

Froperties.^Nitrogen, like uxy*^en ami hydrogen, is colol 
leAs, liL<k^Ie8s, and iMlorie.ss, liy preHsnre, i'aiUetet uiid Pit*ti 
uonilensetl it to n liquiii Wmblevvski and Olszewski otttiiiuo 
it «onie qnantity as t\ ueiirly c(dorle,sii, tranH|Hirent Hnid, whid 
auigeiihi, by it>* mvn v\ii\yi\n\lmh to a whit« snow -like ah did 
It i« only slightly sol nble in water. Frer nitrogen h* distill 
gnished from nujst other gases by the absenee of any ehtirac 
teristie or positive jn-opertieH. Ajjply a Haine to t^onie eoil 
tiiined in i\ H»be; it will lie found to be incoinbnstilde, \m 
merH« a liglUed mateh in the gas; the Hanit' is rxtingnished 
Hhowing that nitrogen is a non-i^npiKirter of eonibni^tion. 

Nitrogen is nmirly fon rteeii liim-s us lieavy a.'* hydrogen. I 

The frtH? nilro^^en in the air mts an a dilqtent of the energetl 
oxygen, with wlneli it torniM nu-rtdy :i mrchnttwa/ inixlure. 

The air in nearly fourteen itml a half ( 14.44) times iw heavy H 
hydrogen. It may In? bijuehed and so Hi lifted. lis nvenige eona 
poHitioii, ineludijig minor t onstilni-nts (whirli will !xj referreil U 
subs4'(|uently), in aa tollows:— j 

(hm position nf fh^ Afmnftp/mr. 

In l««i volumes. 

Oxygen* 2(lfi(l 

Nitrogen , 7(1/051 

Argon /i|4 

Carbon ie jtn hydride ,.,.,.,.. ,084 

Aqueimn vajKir ,,...,,..» L40 
Ammonia, nitrie add, earbu rotted 1 

hydrogen, hydrogen, o»nne, helinnj, > Irticea. 

krypton, neon, xemni . . . . \ 
Sulphnretled hydrogen, snlphwro«8 ) traces in 

anhydride / . ' ( t^iwni. 

Pure dry air, freed from earlxade atdiydri<ie, ete,, ia reinarkab|| 
eon.Htiint in eompositif>n, and eoiilaiiin ap{*Rixi mutely :— j 

Nitrogen (including argon, cte.) . . 79.04 76.9 

Oxygen 20,90 23.1 



VliLUlUNK 



33 



/Vff Nitrogen and (hmbimd Niirogeth 

NfjtwJtbstiiJKiing the coitipariittvt' insK tivity or iiegiitive duirac- 
tcr cif njtn»|^t'ri in its IVei^ coinJition — \\iiil is*, wIkti uimJiribiiied 
with MtliiT cienienlt^ — iLis element, when e<iiiibifUHl with liytiru- 
gt'ii, eiirlxiti, oxygen, ete., it* ii eoiirtiituent of ii tiirge imitiber of 
im|H»rtaut hUl>Hiaiui^, iniludiiig ibt- aiuinunium eniu|M(urid«, the 
vari*m» eyaiitjgfi» counMiuiids tiie extensive ^n>uj> of saltn ealletl 
tjjtruto^, tJie valuiible ujetiieiriai agents known as iilkubtiijs, the 
variouft Hllairninoi*i iiud collii^enie tnatt^TH ekaraet<'ri«tie <if tho 
tifi8ue» ul* animals an<i plants, and w> tbfth. Free nitrog(.4j is not, 
huwevt-r, altogether inaetive, for the nitrogen of the air ajijieiirj^ to 
be iil>sorlM.'d ami iLs>iimitaled by souie plants — ^^-ertuin cr^ips e<>n- 
tiiiuing (nore nitrfigrn than the soil anri manure in vvhieli they 
grew* The absorption is edbeti'd by means of noduk^s whit b oe> 
euroM the rootw of ebiver uiml other leguminous phtids ; thesL* are 
the dwelling-phiet's of ndtroorganisms, and it is tbrougb their 
jiffcney that the wdl m wbirh sueh jiltinti^ grow beeomeH riidu'r in 
intr*>gen. Kxperinn^its Imve iH'tn nnnle with a view to ijulueiitg 
Lbe?H.' organisms to live on the roots of graminaceous (ilant.s, f^^r if 
tliih, eouhl be done a great wiving *d' urtiiieial nlimurL^s eo^fd hi* 
e(rtM:lod. 

ARaON. KRYPTON. NEON. 

It haj* long Imx-ii known that \\\wv\ nitrogen i« prepared from 
attncmphc^ric iiir, the gas olitained is slightly heavier than introgm 
prepared from nitrates or from annnonia. Tlie iiiveHtigations of 
Itiiyicigii and Ramsay have pn^ved that this is due to the [>resenee 
of another ga^, heavier tlian nitrogen, to whieh, on him ount of 
Itn apparent eliemicul inaetivily, they gave the name nifjon («, 
with»»iit, f\i)tn'y trgon^ work). Its dt-nsity is about 1*J, It is 
prt?Nt'iit in atinoKphene air to tlie extent of nearly I pereent. 
li<H*ently a eomponnd of argon with eurhon ba.s been obtaini'd by 
tbe pannage of tlirtri^ity Ixtween tliin larboti [ndis in an atintis- 
pherc of argon; and exjyeriments show thsit it probably eonibines 
wilh the va(Mir of nnigne?iinm at a v*'ry high tenifH rature. Arg#>u 
ami helium oeeur with nitnigen in X\w gas<'s id" many naturally 
a^rateil watern* 

UamKjiy obtained anotlier element from atnoispherie air, tn 
which he gave the name Ktyptftn (hfw^Tor^ krtjpf(m^ bid^len): 
traet>* ordy are preMent. Ramsny and Traven^ mbseqnently iiti- 
ntmneiMJ the presence of anotlier elemint, Nmn (icw;, ntm^ new), 
and Ramsay Xcnofi, 

CHLORINE. 

Soared. — The eldef nonrce of tliin element is cominim salt, 
mon» than huH'of whieh u ehlorine. 




34 



^'ON-METALLIC ELimENTS, 



Reparation. — ^Abtiut a quarter ut' au uunct* itiicK uf salt 
aufl of hlark iimiiguiiese i>xide are [iiixefl, plaf*e<i in a teet- 
tuhe» luirl covereil with waiter ; on afUiinji a small *|Urtiitity of 
siilplnirie nv'ul, evolution of uhUjriQL' eonimeutt's. For thi- 
jiiode of colk'C'tion .sve the ft^llowiui^ paragraphs. 

Another process. — At* I he aeiion of the suli>hurie acid on 
thi' sah in the a hove proee^ss i-s mainly to give hydriM'hlorie 
ueid, the hitter ueiil (ahiait 4 piirl.<) and the hlaek mangtui- 
t«y oxide (alwjut 1 part) may he used in making eh lorine, 
iiiHtead of sidt, f<ul|thtirie neid, antl black numgunese oxide. 

Collection and Properties. — Free ehlorine is a Hnffoearing 
gas. (are tlierefttre must he oliservt'd in expertmenttiig uith 
this elentent. As snnii ns its [K'lietriitiiig odfO* indN*ales that 
it is escaping from the test -tn he, the cork and ilelivery-tntie 
(aiinilar to that used in making tixygeiu shonhl he litlt^l nn^ 
urtil the ^iiA led tt> thf UKtoni «if another test-tnlie eontaiuing 
Wilier (,F»g. 10). When thirty or forty small hubbies have, 



Fui. to. 



Fin, n. 





Prepmnilinn t»f ehlorine. 

pftflsefl, their evolution being ttSMisted by slightly hesitiTig the 
generating lulw, the latter should be rennnn^d to the enj>- 
iKWird nsniilly |m>vided in laboratories for jierforming opera- 
tions with noxiou8 gase«, or Ije dismounted mid the contents 
c^;irefnlly and rafiidly washed away. The water in the col- 
lecting-tube will ivosv be found to smell of the gas, <4dorine 
ImngpoUible in abt)nt half its hulk of water. 

7Mr<ffr fjunnftfir^ aniy lie iinido from hydroehlori*' aeid and 
blaek imiaganese oxide (4 to 1 1 in a fla^^k fitted w ith a deh very- 
tube, the flask Vjeing snpiwrted over a flflme by the ring of ji 





"1 



OBLORINE. 35 

retart-atand (Fig. 11). A piece of ciinlboiird on the neek of the 
folleetin^-bottle, iw inilieatnl in the figure, retards dil!'n?^ion of 
t'blorine from thi^ battle during the prnt'e^^s of ctdlrellnn. 

MtumtaHtinm, — Fhusk.< miA similar i;hiss vessels are less liable 
Ui True tu re if pniieeted from the direct aetinn uf the Hjuni- by being 
jdfleed mi a pieee of wire gjin/e ubtiut (J inches wiuare, ur t»ii il 
jfand'bafh, thut is, a saueer-tihajied tray of sliret iron *tn which a 
thin hiycr of sjind irt j^bieed. 

During these nuiuijiulationH the operator will have noticed 
I bat chlorine is of a light yd lowisli-grecii eobir. The tint is nh- 
servable when the giis is collected iu large vessels. As chlorine 
if* soluble in watjer (2 J voU. in 1 vol. at (l^P F., lo.,'>*' C), it can- 
wot be economically j^tored over that liquid. Being, however, 
Deiirly two and a half times ius heavy as siir, the ^'^s nmy be col- 
lected by simply allowing the ilcli very- tube to piuw to the botU^ai 
of a dry te»t--tube or dry bottle ( Fig. 11). 

An ira|>ortttDt propf^rty of free tddoritie is its IjleuebinL^ 
p^wer. Prepare a c^ilored infusiou by pladng ti few chips of 
b>gw(xjfl in tt t4Bst-tali€ lull f full of hot waler. Pour off Rime 
of ilm red infusi«>a iuto another tube aud arid a lew drops of 
chlonne-water; the red color is rapidly destroyed. 

Free chlorine readily decompose* nffensivQ effluvia; it is one uf 
the mo»t powerful of (kodnrizem. It als** deenmp<iHeH putrid and 
infectious matter; it ih cme of the be^^t of dlvnfectantn, (Antisrptic^ 
are subntance** which prevent putrefaction.) 

Oombmation of Hydrogen with Cldoriiie, formiiig Hydro- 
chloric Acid.- — ^If an opjM>rtunify occurs of geneniting eldurine 
in a closed **band)er or lu the o]M'n iiir. ii test-lube, of the 
same size as oue of thone m which hydrogen Imi* Iwen retained 
fn>m a previous ojxjralioii, is filled with I he ^':as. The hydro- 
^eri-tul>e is then inverted over that t^mtaining the chlorine, 
tlie mouths l)eing kept together by encirelinjyr thenj with a 
fiti;,'er. Af\er the pi.sej^ have mixed, the mouths of the tube?* 
urc* quickly brouj^ht into eontact with a flatnr, wlien ex|>loHloii 
occurs and fumes of a eompHinil of liydnH*hlorie acbl gm 
wilh the mointure of the air are formerl. The Hydrochloric 
Acid of pharmacy (Aridum Ilijdrfwhfurlenm^ V, S. P. j Inn 
sululiori of ibia gas (made m a more economical way) in 

The fore^'oinj^ experiment affords evidence fd' the (K»werful 
aitirdty of chb»rine and hydnitren for each other* Chlorine dis- 
•^dved in water will, io ,sun light, .slowly remove hydrogen from 



J 



36 NON'METALLIC ELEMENTS, 

some of Uie water and liberate oxygeo. The blencbing power of 
ehJurine b geniTally referred Uj t h isi ind i reel uxulixi rig eflwt which 
it jircKluces in presence of water; for dry chlorine does not blcitch. 

Bensity. — Cbloriuc is more thau 35 times as heavy as hy* 
drogeu* A wiue-l)ottle wutild hold about 35 grains. 

SULPHUR, CAEBON, IODINE. 

The physiral properiien (color, hanhiess, weight, etc.) jkj6- 
8ees^ed by tliei^e ek^iueut^ when they are in the free stute, are 
probably familiar to the student. 8<jme of their leading 
cheuiieul characters will aljso l>e nnder^t^xwl when a few facts 
conceruinf,' each are made the suhjeet of experiment. 

Siilphiir.^Burn a !<mull pii*<^v of sulplmr ; a [>enetnit]Dg otiar 
18 pnxiueed, due to the furuiaiinn of a rtilorle>%* gai^ This 
product 18 a eheniienl ("onijxmnd fornietl by the union \A* the 
oxygen of the air with the sulpliur It \i< termed sulphurous 
aidjydride (or sul[>hurous aeid gai* J. 

Carbon, in a more or les*? puri^ condition, is faniiliar. in the 
free form, a?* »oot» coke, ehartHml, gnijihite (or jjluinbasjo, |x»p- 
uiarly termed hlacklead ), and iltiirnond* The presenile i»f 
combined carina, in w*xwl and iu other vegetable and animal 
matter, !« at once rendere<l evident by heat, Fhu*e a little 
tartaric aeid on the end \>i' a knife in a flame; tlie hlaekentng 
that fXH^ur* i^ due U\ the sepaniticm of ctirlioti. The black 
matter at the extremity of a piece of half-burned uood ali*a 
18 free earl>on, 

CarlKiTi, likf liyilrofreii, pho!^phr»rin?, and Hiifphnr, h^Ls a great 
atfiiiity ff»r oxygon ut hi^h temitenilun*?*. A j^triking evidence of 
that affinity iit the evohition, during \i» rondnixtion, of suRu'i<'nt 
heat tM make the materials eonrernod red or evrn white-hot. 
When ignited in the dilut+nl oxygen of ihe air» carbon dimply 
hiirn^ with a nnHlenite glow*, n,H iwen in an ordinart' coke or char- 
eoid fire; but when ignited in pun* oxygen, \\\v intensity f)f \U 
eombu«tion i?* greatly exaltinh Tin* f>n>ducl fd' the eoad^inalion 
of the two idcuient**, if the oxygen be in oxct*«», is* an invisiVde gaj* 
lerniwl curlMtnic ardiydride (nr t^arhonic ncid gas) ; if llic carlHjn 
be in cxec^ aad the f4'nnH»nitun» very high, attotlier invinible gas, 
tenrR»«l carli^jnic *»xi<le, rc*<ulL«^ 

Iodine, — \ (rrojninent chemical characteristic of free 
ioiliue is it>* great affinity for metak Pla<^ a piece of imline, 
alKiut tlie si/A* of a \Mtiu in a t<'Ht-tul>e with a small quantity of 
water and a<ld a few iron B lings or small naih. On gently 



J 





THE ELEMENTS. 

warming this mrchauieul mixluff^, t^r evea shiiking, if longer 
time Iw allowed^ the color iirid iwior »jf the itwHue disa[)|iearj 
it hog cheinicaUy uooihined with the irun — ii ('hem't<'*il eottt- 
pound has Ik'cu |ir<Kiiic'e«L If I lie lii|uid he iilu^retl, a eienr 
aqueous stiiutiuo of the com|KJUiitl of the two elemeiits^ i.s ol>- 
tained. 

This compiund is an iodide uf irtjn» Its ssolntion, nui<le us 
a^Mjve, and mixed with sugar, fnrnih, wht-u of a eerUihi 
fltretiglh, the ordinary Syrup of Fernnis In+lide of pharumey 
(Stjrup\ut Ferri lodidi, U, 8, P, J. The solid iodide m ol> 
talned on removing the water of the above solution by evap- 
onidon. 



Su/phur and Iroft, also, when verj' stroTigly lieate<l, chtmittttly 
vmuliim to form a substance whitli luus nniie ol' Uu' propertiets of u 
wiij'/iir^ of s*ul|>hnr and iron — thiit in, hits iitmo of the ehararters 
of s^nlphur and none <»f iron, hut nt'w iiropurtkH altogethrr. The 
product \s ternuHl Ferrous 8ulphide* It^ miinutiu lure and ust^a 
will \\& alluded to in treatin^r of the coui]>onnils of ir«in ; ft is %\\v\\- 
tiohed here as a simple hut striking idntitration ol tlie ditlerence 
bc»twe<*n a chemical compound juid a mcchanica! mLiiurt'. 



THE ELEMENTS. 



di^JfTtOy^^K ^7^ U- 



From the foregoing statements a general idea will have 
lieen ohtaim^l of the nature of several of the more fre<[ueijtly 
oeeurring elements, Some additional facts eoneeruiiig t!iem 
Timy l>e gathered from the following Table, whit^h give^ i\w 
origin of the namea of a number of the element-s: — 



Ahixnlntum < . The mHallic Imsi.-^ of uhjin was \\\ first icmfmiiiflod 
with ihat of iron huI|i}kiOs wliicli was the aliiiii of 
the Komaus, :nid wus ^io ralltMi in uUuHifJii tu itH 
t^mic propertjew. from rt/o, I mmiUh. 
(Ammoillum] . Thli iKidy b not an elemi nt ; but its ounfiotieuts 
k%\si ill »U uunuutiiral ^\is, and ii|«i(nn*iiily pliiy 
the [Hirtof such <L*h'iiH'nlJiH.H fHiUissinio atul siKliuiu. 
Sill amiuoTiiuc uimoioiiiiiin thlMride) was linst <»l>- 
Uiiiied frmn mur tIk- teniplo of JupiU<r AniiUttn ui 
Lihyii : heme the name* 

. , iri^i f>,tih»), or *m/M>ii (stimuli), wum the tJieek immo 
for the native UDtifDony ^iulphidi'. The word im- 
tinnttiff is sjiiil to bi' ilerivt'd fr*>ni iin (iinti) 
'tfioif'Hi, and nmiut', Frtnch for monk, from the fmi 
thtl «'t'ft;»tn motik* w'eit* ptjiKontnl by it. 

. , Ftittn o, without ; iftyor (ergon), work. 

, , 4pir«i'ur«i' ^nnsenikon), th*.^ iJreek immo for orpi* 
in«?iit, iiii simenie sulphide. Common tchit^ ar»mne 
\b ftFBcnh^ Lrioxiile, 



38 

Barium .... 

Bismuth . . . 

Boron .... 

( Bromine . . ,. 

Cadmium , . . 

Calcium . . . 
- f f Carbon .... 
f^ Cartum .... 

f ~ Chlorine . » , 

Chroraium . . , 

Cohalt .... 

1^ Copper (Cuprum) 
f -f Fluorine . . . 

Qold (Aurum) . 

^ Hydroffon . . * 

Iodine .... 
_, Iron(Ferrum) . 

Lead (Plumbum) 
Lithium .... 
Magnesium . . 

Manganese . . 



THE ELEMENTS. 




From /impvt iharus) Atvfi V, tn Hllii.sioD to the high Hpe* 

cifie gnivity of "hmvy simr/' the most c^niiiioQ 

tof lilt? Imriutij mi lie nils. 
Slightly altered frwm tlie Ctermaii WltutHth, derived 

from lM«fM'mattc, "a iMMiutiful muiidow." (i natue 

given to it urig^iniiily by the uld miiit^raiu ailii^ioti 

t*j ihtt |»rettiiy variegated ilnta ureiienU'd by the 

freshly exptined t^urfare of this eryslAlljue metAl, 
From bm'iik i>r bnurni\ the Arjibic iiumti uf ftortix^ the 

siibHtniice from wtikh the eleiiieQt was lirst ob- 

taiued. 
From /J^MOf (brimios), u xtink. It hiii> cut intobT- 

ahlt) trtlor. 
KaitAtia. {kiidiueiiU waus the iiiu-ienl mime of «JHliiiiiiii(? 

(y.ioc carlKjiiMte), with wbk h ejidmiiim carbomite 

vvnA long confoTiiideii, the iw*> often cK-riirriug 

t^igether 
Cnlc^ fimf. euleiura oxidi'. 
From cttthn, i!<wt/, whkh h cliiiefly t-iirlMm. 
Discovered in \<r^yA, and mimed aft<T the |jlauet 

Ceit'4t, wliieli wa.s diMovered on Jan. 1. IN>1. 
From j(A-p6v (ehioros) grem, the color of this tde- 

meut. 
Frmn j^pwiAot (chromii) *Wwr, in al In si on U> the ohar- 

iiet4.'risti*J iviiiM!iirHii*-'e of its «i11k. 
i'ohdfu^, or Kotntid, wns ihii imme of it ileiiion sup- 

P<ks4mI to iiihiihit tbii inin**s of (Jermiiiny. The 

*>reH of lulKilt were furuierly lr<mlde?Mime to the 

fiermftti miuers, liml he: nee rcceivetl the name 

their metttllie nwlirul now beiir^. 
From f'ffpntjtf the mime of the Muli term noun island 

where this nietul was tirwt worked. 
Frmii /«(>, [ Hotr. Cakium lluoride, its sourc**, i« 

L'onimoid}' u^ed as a Hux in metal turgie opcm- 

tion!^. 
Aftvum (IjtiTin^ friim a Heiirew word signifyius tbo 

eolor of fin^. 
Ooid : a ^tniliir wonl is espresslv<* of tft'tttht tiftlow in 

several i>ld laiignages. 
From i-&*tp Oiudor) vater^ and yiv*<rit (gcDCsii^). j?rit<*r- 

*itmn, ill iilltiJ!«ioti to the product of it« combustion 

in air. 
Fio!n toy imn) « n^iohi, and *r*o^ (i>idos) /iJtn*<'M, in 

reference to the enlor of il>* vafwir, 
rrehistorie. The Hpellin^ may l>e fn»m the Saxon 

ii'ivi, the proiHifieiation from the Gothic " »<irn/* 

The derivation in peHia|K< Aryan; it pmlmbly 

tiriginnlly uieaiit meUil. 
The I^itiii expiv,sf*e-4 **Bomethiiig heavy "; th<5Sax<m 

hrd has a !>^imilar sig^nitiealiim. 
From Ai^tfioc 1 litbeio*i) iditn^f, in alhisiou to its sit|v 

posed existeuce in the mineral kini;dnni only. 
From Magnejtia, the name of the town {in Asia 

Minor) near which the «nbstnnee now cntletl 

"native nia^iesium carbonate** wjw first dis- 
co vertMl. 
Prolnihly the Bltgtitly alU^red word maifnetia^ with 

wlititH* cotufMiunds i1u>se of mauganesG were tan- 

fonmlcd till ITKJ. 





nffiltiHiiifrHin, from fiw^ Hnitlor) tmtfr, and apyvptt^ 
\.nt^uruH\ Mthfr, in ulluaioii to itn li<iin<l und Jus- 
truLis L'luintctcTS. Atrrfuitf^ ul'tur Ibn ui^KSt'iigi-'r 
of the gtitij<, oij account uf itn ,suscc|»libiliiy of 
muLioti. The uld luuiie quickifiirfr also tijdicut«« 
itri n luly millliilily utid silvery up|tcamiice. 

Xichf jrMoi lrli^^ wmthtejM. Nicktd on) was formerly 
cjillcd KHpfrrniikd^ fnine atpper. Wbi^ii li uew 
idcnicnt was fuyud in Uic urv, llie utiiiit* iiit:ktd 
w»ii ruUiiiied fnr it. 

Frmlu fitpoy liutrou) aiul Y«i'*aic (guuesLs) ifmrrtitimi, 
i. c.^ (jfHfnttof of nUrf, 

From ofLi^ I oxiisj nnVi, mid ^tftirif i jjieticsibl (fi'Hcmfion, 
L f., gt'ijcmtor ofa^iilti. When hml discovenwl it 
wu^ jsiiijpitSLHl to filter iiitu tbc Lomi>oaiu>Liu of all 
acidii. 

*«« (jibo>^) ?tf/A/, aud ^ti>*iy (pheruin) to bear. The 
lijLflit it(iUiit6ruay be di^eii an expuBiug it in a dark 
rmjin. 

From iduihm {"i^imnUh), diminutive of iUata, Mthrr. 
It soiiit;^wliat n^ii<5iJible»tiiLver, but is 1c»h whitt' and 

lu>itriM18. 

Knfinm from htii, Arabic for axhr» {sen 8ml in mi. 
Muttdfuriigries in wbicb romi)oLind>« of |»otas»inm 
ami ullivd sodinm huUh are iinide. are niUed fi/lWi- 
workK to tills {lay. iXttnminm^ from pttUt»h, Vni- 
a>b sfi-iulb^d lM'c:in?«t5 olmiincd by cvajionititijg tb« 
lixivium of \vo<h1 nHhea in |h>1«*. 

From Hih'i, Initio for put, which is luurly all f^ilira 
(silicon oxide:. 

'Xp,yvfm% (arwinrfi!-.) nihn; from ipyia (ar^os) vi*hite. 
Words i^»semblin)? tlie torm itilnT ocinir in s««veral 
biiignageSt anil indlt-aU^ n while uiipvamiH'c. 

Nntnitm, from nittnttt, the old name lor certain 
natural d**|ioHits of t*(idium carlKmale. SoiiiHm, 
from notlit^ the name originally given to the n^i^i- 
due of the C(»inl>nj!Jtion of niarino plants. Soria 
afibes VtX've cbeininilly dtKtinj:nished from |iot- 
hi^ by Dnbamel in 17:i<j. IVevioitsly buth uere 
fnimply kali or finheii from two diJTeri^nt j*ourcc8* 
Sir Humphry' ]>avy Arst iHolated the two metaliH 
in l.H)T- 

TbiK intme is conimenvonitivi* f»f Sfrmitmn, a mininir- 
villagr in ArKvlexbirc, Scotland, in the neliibl><»r- 
IoumI of which tin* inincnil known a» utroutinuitr, 
or ^trroitinm carbon:it<', was tirs*t found. 

From «i/, u iniH ami nvp (pnri ,/frr, indicutiuj; itjicom- 
bu^tjtkle qmiliiicH. Its lonmion name, hrhnKtottt, 
haft the sjinie mcauinjt;, Iwdn^,' the Hli^btly altered 
Sjixon worrl, hvtfn»tonf^ i. ^., bnniistone. 

Beth worilis ure |io>«Hildy corrnptionK of the old Rrit- 
ish wonl nUw^n, or I he Sjikoji word utttn, a stone. 
Tin was fin<t ditaovered in rornwadl, and the arv 
(an lixideli is rallied thtMhmr to tbe prcHenl day. 

From tier. %iun. tin, with which Zinc iscemB at first 
to have been confounded, 




40 NUMERICAL AND PHYSICAL MATTERS. 

QUESTIONS AND EXERCISES. 

T)i«liiigin?ih Wtwtjen the art ami the »tirtu'e of clu'mij^trj-.— Of how 
niuny t^lftiietit>> is terrestrial niHlliT cotupost'd 'f EritiiDcrute ihv ehiuf 
noD-nietulIii^ tleoiLiiitii.— Dt'-^'ribf a profess for the iirepuruliiiti of oxy- 
geu. — Hmv iirc guj^xs usually stored? — Mention i\w cliief i»ro|H.*rtk"s of 
oxygf^J — What is the source of Miiimal wurtiitU ?— St,it*MlK" ]ir*ijiortioii ut 
oxygen in air.—Is the |)r«i|>ortioi!i rotistiiiit. niul wljy?-(iJvL- a ni'.4hotI 
for the eliniintition of hyilrogen from water. -Stat t^ tb<' p^fjiertiL's of 
hydrogen, — Why is a mixturti: of hydrogen and air explosive? — ^Exphiiii 
the etTeris |inHliieible by the igiiitinii of Uitrv i|uautilies of coabgn^ and 
uir. What in the nature of conibHe^tiuu? — iKdine ;i comfmntiUf ami a nup- 
pat'trt' of t'OHiAtwrfitun, — Oe-Kt-riliw? the structnit' of tlame. State the priiHiiplo 
of the lifivy Nafety-liimp,— 111 what proportion is hydrogen lighti*r than 
oxygen?— W bat do yon iue»n by dijfivtum of jtjases?— Stat*^ Gmbain's law 
comorning diffusion. — Name the soiiree of phospborus^ and giire ibi char- 
acters.— Why does phonphorns burn in air?- What gas renniina wben 
ignited pboHphorus ban renn>VLHl all the oxygen from a conflned p<irtion 
of air?— Mention the properties of nitrogen.— What otlice is fuinUt-d by 
the nitrogen of the air?— Stat** the proportiona of the eliief eonstituent« 
of air.— Mentiim the minor or occasiional eontitituent* of air.— What ir; the 
proportioi> hy wfigbt of nitrogen to oxygen in the atmosphere? — tiive 
the speei6e gravity of nitrogen,— How w chbirine preii!\red ? — Ennniersitxj 
the pro|wrtiert of ehlorine.— r>efine tlie terms ff^wfon^cr and <!ixinfectmtL — ' 
Explain the bleaching effect of chlorine. — What jiroportion of hydrogen 
to eblorine if? neressary for the foruiation of hydroehlorie aeid g;ift? — StAte 
the t»rominent chernjeal and physical ebameteisof Kulphar— Sttite Ibofs*' 
of cjirbon.—8t4ite thi>i»e of iodine. — Give the denvations f«f the nanii^ of 
somo of the ci'lements. 



NUMERICAL AND PHYSICAL MATTERS OF SPE- 
CIAL IMPOKTAKCE IN ELE.MENTARY 
(HEMISTUY, 

The Metric System of Weights and Measures (the \von\ 
metric h fn>iii tlie Cirt^vk //ir/^*'>» metrou, nicat^ure ) \slii**li in 
now in rtunmnn uhc- iti jnoHt of tlie iM)tjntnefl of Etirt>|K» and 
else\vhert\ |>rasen1i* i^eYerjil iidvHiitaf^cs nver ihr tAder i^yMemii, 
The two t'hief tnlvalllIl;fl*^^ of the nitdric" syf^teni arc, that <"t'r- 
liiin of the tinits Mi*e relalnl iti one Miiollier in uri exeet^liujLrly 
simple nti«l pnietical niaiiiier : hikI ihnt ihe jjystem 18 u diH^i- 
ma I one tliroujjrhoiit, nw\ is tlup* iti nimpUdt* hiinnony with 
I be universal nuale of coyntin^i. 

The metric syt^tem of wei^hlf* atnl measirrtf* In fotiutliHi uri 
ilie metre. Fig. 12 represt^ntii a pKK'ket frOdin^ measure the 
teoth part of a metre in leni^lh. clividtMl inlo 10 centimeti-es, 
and eaeh centimetre itito 10 ruillirneires* 

The unitB of the Mystem, whh their nuiUiplesand submtil* 
tiplei*, are as follow:*:— 

Leng^ — The Unit of Length is the Metre, derived fnjm 



THE M ETHIC SYSTEM, 



41 



the meftsiirement of the Quiulnuit of n Meridian oi' i\w Kurlh. 
f PracticnUy it m the leiigtli of eeilaiu eiirefiillv prt^ervi^d 
Imrn of melul, from which iNipies Inive \mm tiikt'ii.) 

Siir&ce. — The Unit of Sni-faee Is the Ake, which is the 
square of Tea Metres. 

Fig. 12. 



rmii^tiiiiiiii4i!''i'Ni[iiiii>nfiiit![!ii4iirru^ 



=® 



The decimetre. 

Capaci^.^ — The Unit of Cnpaeify is the Litre. It was 
originally intjemlefl that the Litre should \m^ exact Jy one 
CuIhc Decimetre, lojt the Stimdiird Litre althoyj^h very 
nearly in conformity with this iiitention is not ahsoliitely .mv. 
(1 Litre — LDODHi Cuhic Decimetre. ) In the U, R Phiir- 
niacopa'ia tfie Cnluc (Centimetre is iHiderstoo<l to be identical 
with the miliilitre* or thousandth jiort of a litre* 

Mass. — The Unit of Mnn^ h the GkammIv. ^ which in the 
luiijis of that quantity of lUstilled water, nt its maximum den- 
gitj p<iint (4^ C.) which m^cupies the space of the one- 
tbousaodth part of a Litre (1 ^Iillilitre;. 

Table. 

Nate, — Multiples are denoted by the Greek words ^*Deka," 
Ten, *'Hecio/^ llnmlrcd, ''Kilo/' ThouKaiKl 
8ubclivi»ion» by the Latiii wonts, "DiHi/' Onc-ti-ath, 
**17enti," One-humlrelli, ^^Milli," One-thonwindth. 



QIMtttte*. 


Umih, 


Surfiwc 


t'upftiity. 


Wixinhh 


1000 


Kilo- metre 




Kiki'litif 


Kilo-j^ramine 


100 


nefto-iiietPB 


HiM*tnro 


Jlertn-litre 


He^jto-gniiiimo 


10 


Iloca-incrtrc 


• ^ > 


l»erii li(r<^ 


nt'iii'^raiiimo 


I nTtiiui 


METRE 


ARE 


LITRE 


GRAMME 


,1 


Ik»ci luiHre 




Ik«t'i'Htrr 


r)c<^i-i;ri4iiiiiii* 


.01 


rVtiii-fiictro 


C4*fitiar<_^ 


(>-iiti-lirn' 


t*<inli-(fniniinc 


.001 


Mi1ti-iu4*tri* 




Mtlti'liin^ 


Mitli gmmuie 



When the* Metric method is t'xrhisively adtijiteih tlu*M«> tl^nits 
mid Table, eom|irisinji tlie entire System of WiMi^bb* and Measures, 
rr|»ret*ent all that will lie cH»ik'ntial t<» be IcanoMl in lieu of the 
numi^rous and eompHcated Tables hitherto in UBf. Adtijitinjr the 
ptyle of elementary bfM>ks cai arithmetic, the table may he ex- 
panded thu**: — 

' The irord gramme i« «ometiini»«, anfortuaat*?I.v written gram, which 
t4M cloMily fewmiblci thi^ word grnin. 



^'1 



42 yUMERICAL AND PHYSICAL MATTERS, 

10 niilliifraniuieH aiHke I rt'Htiy:raiiMJiLv; ]0 tvnligrumHies iii:ike 
1 <leri|^nytime* 10 liL^igraiimuK iiuikr 1 gniiume; III grriuime.s 
iiiuki" 1 cieL'4igniinirit\ or dekagrmmuv; 1*1 tlc'ai|!^nuiniit"s iiu^kr 1 
htrta^miiujjr; III bix'to^riuiuiK^ niakt* 1 kiln|rriitJiiiie; III luilli- 
litrt^ tuake 1 centilitre, ttr. ; 10 iniHiimdrt'rt inukfc! I centimetre, iit<.\ 

AhhnmaHonji, — Metre = m ; deeimetre — dm ; eeritinietre = *7?4; 
mi Hi metre = mm ; kilcnnetre =^ km, Sijuare metrt* — m^ ; cubic 
metre = w<*; anci h*! oti. Litre = / ; tleei litre = <// pte. Kilo 
grHimne ^ % ; deeagramme = dkfj ; gniiiuue — </ ; dtvij|:nimrue — 
d{j ; centi^rramim* — cy ; and nidligramnie = mtj. 

The fcillr»wiag approximate equivaleutH iif metrical iinita should 
be eommitted t-o memory*: 

1 Mttro = 3 feet 3 incheii aucl 3 ei^rhtfl. 
1 Are ^% square wlmw gide in 11 yards. 

1 Lilrc -^/2G12 IJ, 8. liqilirt galloaa 

I (Tram OIL' - ITiJ gmiuH, 
Tli*^ Iviloim'lre is t'tjiml to H*Mj yards. 
The Hrtiurit^ 2h in rt-Ji nearly. 
The Metrkt Ton nf KRHI Kilof^niaitiRs lU cwt. 2 qrs. 20 lbs. 10 oz. 
The Kilu^ranime = 2 lbs. 3i oz. nearly. 

A litre ut water at 3**^ F. {aH'^* C.) weighs 15,4:12 ^^ai us; at 
50^ R (Hi° C), 15,421^ graifiKj at GO'' R (lJ^.r>*» C.), iri,418 
grains; at TO^F. (21J°C.), 1 T), 4 IKl grains; and atHirF. (2<i.7''<:\), 
irv,3S:S grains (rile). 

/heimtil Cmnatft'. — In most countries where the metric system 
»d weights* and meiL^iires is em|>hiyerl, a deeinial eniiiap- is als4i 
adof»ted. This, r^nyoiiied witb ttie ordinary deeiunil method of 
enumerating, wineli tiirtiiTiatdy is in universal unt^ sim(>lifii^ 
ealeulations r^l all kinds. 

WEItniTS AND MKA8URE8 OF THE METRIC SYSTEM. 

WEKillTa, 

1 Miingramme ^ the thouaiindth partofnnegna.orO.OOl gnn. 
1 fJeritigrainme == t!ie hundret!i ** '* 0J)1 

1 Dectgraniaie ^= the tentb " ** <i. 1 

1 trramuie ^ weight id' one millilitrc of dij*- 

lilled water at 4^ O. (3**.2^ R) 
1 Dekagramme = ten gnnnnies 10.0 *' 

I H ec tog ram aio = n lie luind red grammes IIHIJ) ** 

1 Kilogranniie = one thounand gramnien lOOO.tJ (I kilo). 

MKAHTRK^ OF CAPACITY. 

1 Millilitre = the vcdurne at 4** C of 1 gramme of wilier. 
1 iViitilitre = '' •' 10 " •♦ 

1 [Jeeilitre = ** *' UK) *' " 

1 Litre = ** " 1000 '* " 



THE methw system. 



43 



MEASURES OF LENGTH. 

1 Millimetre ^= the thoiL^^juitlth part of one melro or 0, UOl metre 

1 Ouritituetre == the hiojtlretli ** '* lUJl *' 

1 Decimetre = the tenth »• ** (M ^' 

I Metre = ** '' \}J} *' 

UELATIUNS BETWEEN THE VA1UOU8 UNITS OF WEKillTi? AND 
MKASl'KK,siN V^K 

1 5fetre = nHJMm iiu-JieH 

1 Yard = (HltU440:i metre 

I Litre = 0. 2fi4 1 7(*4*>7 liquid gallon 

I Liquid gallon = 3.7Hr»4»'J4 litresi 

I Fliiidouuee =^ 29.r)7;i7 liiillilitres 

I Kilogrumnie = 2.2()4(J2 jwninds or L')482. 3563Q grains 

1 Pound = 458.5924277 ^^mmuies 

1 Ounie = 2KJ1495 gntmuio* 



1 AixithecarieH- ) oi imoiu 

* [ =; Si- 10348 irrammea 



1 Grain 



G4.7989 inillignunfues 



COMPARISONS OF WEIGHT ANI> VOLUME AT MAXIMUM DENi^ITY, 
IN VACUO. 

1 Litre of water weighs I Kilogramme 

I Gallon of 'water weighs 3785.434 grammas or 58418.1444 

grain!*, 
1 Flnidounce uf water weigba 29.5737 grammea or 45**, .^92 

gra>ins. 
I Apothefaries' Ulnnee c»f waiter mejiHure?^ 'H, l(f34H luillilitrea 

or cubic centimetreS| or 504,829 minimH* 



QITESTIONS AND EXERCISES, 

DtJon Rome ad vantages of the metric idcfi'imii)) i^y&tciu ijf wri^'ht^ 
ifcni] mifastnres, — Whal is the iliiil' unit of tJiu njutrie system? M*iit ion 
tbc niiiucft fjf th<* U)«*trie uuitw of Hurfnee, esiiuirity, tuid mut^, nod Mniv 
bow thvy !irt.' derived from tin* unit of kngth.-HdW anj innltiplcM of 
metric unit8 iodi«'Htt'd?— State th*^ de.si>:ni«riMn uf stilmojUi|»Ie."^*if nut'tru' 
unila,— How many metrt^s sire there in a kilnnietrv V -How luatij iiiilli- 
nif^triM in a mi'tre?— How nmuy unonme.s in 5 kilounininus?— Huw omny 
milltKrammej) in 134 gminmes?— In Irtilt* t'luUgnuioiieH Imw nniny 
Ipunitnt'sV—In a metre me^wure 5 rttjitino'trcs wide imd 1 eentimrtre 
Chirk, how many <Mihie ee ii timet rt«? — How riuiny litren ure ee>riljiined 
hi RL'ubie metre t»f any lit|uid?— State the I'liuivttleiit nf the metre in 
fwt and inches,— How mimy H<jn!in' yanln in an jire?— How mniiy 
fluldoancHB in a litre?— How manyounee^^ tn a kilu^rumnte/ 

Mrrj^urrmtut nf Thnperrthire, Ffthrmhf^f nud (*ettfitjmde Thtr- 
.W^omHer iStftlra (Fig, lvJ).^^The mensnrement of temjH^rature is 
ait by aid of the thmnumttfr,^ the eonstrnetion of which 



44 



NILMERK'AL AND PHYSICAL MATTERS 



ai. 



ThennometrJc scales* 



18 described in the Bectioii tm iiuuiitjtjitive >reiusureintMvts. The 
tbtTninnit'ttTf* I mpioyed in Itir UijiIhI Sliitej*iirt' [>ructic;illy ulwuys 
gnuJujiteci iii tuxoriiami* with oither the Fahrenheit or the IVjiti- 
p |r> gmiie scale, < Jii the i'enti|^rjide (t\) i^eale 

M t.^ I. J. i' .f I the freeziiii^-THiiiit of water is iiiarked /,eni, 
iiJid tile hojJitig'iM»irit MM; on the Fahrenheit 
(F. ) settle the zt.'rrj k [>hieed rill degrees heh^w 
the freezing- [mint *\f wiiter^ anil the l>i*ilirig- 
poiiit is 212. Conversions of expressions of 
ti*mpenitiiri>i in degrees F, jnt4i the enrres- 
pf>nding exprei^i^ioiis in de^ree^ C, and eon- 
versions in tlie revers*.^ direetioii^ can be made 
Ijy apjilyins^ the tolhjwiiig rules: — 

i. F/t4> C. HithHtraet 32, cnuUijdy the rtv 
niainder hy •% divide the pnKlnet \>y II. 

liiarnpfe: — 68® F. Fin<l the corresponding 

t;H-82 = Hf> ; 36X5 = 180h"U = 20. 68° F, 
eorrespnuds to 20** C« 

2. C. to F. Multii»H' by ^, divide the pro- 
dnet hy fi, add H± 

Eu'ampk: — 52** C. Find the corresponding 

52 X 9 = 468; -ifjS -r 5 = 98,6; 9H.6 } ^2 = 125.6. 

52 ^'C. correapoml« to 1 25.6° F. 

The following ig an eiwily remembered rule for converting fram 
°C. t-o ^F. :— 

Double tlie number of degroe*i C, substrml from the rewult itn 
tenth part, add 82. 

Tbus^ applying the rule to the example immeiliately preeetling: 

52 X 2 = 104; 104 - 10.4 = ^3.6; ^3 -f 32 = 125.6. 

52 **C. eorresprmds, as above, to 125.6 **F. 

Care fnuat be taken in dealing with exiiresainns of temperature 
having the - sign; iliat is, with expressions rei>ri»senting tempeni- 
iures lielow the xcra point** of the re^[HH'tive st^aleH. 

Ejctimpk: — -4 ®F. Fiml the t'orrewponding *^^ 

-4-32= -86; -36 X 5= -180-^ I* = -20. 

-4 *»?. corresponds to - 20 «»a. 

Mtnmirrmenf of Afnumpht-rif' Prmmrp. Thr Rtiromrtei: — Tije 
analysis of gases an<l vapors involves determiujitions of the varying 
pretttrtire of the atmosphere a** indicated l\v the tmromtter (from 
/^w>f, barm^ weight, and itiTi»fn\ mffnm, measure). 

The onihuirtj mercurmf haromrfrr is a gla*vs tube .^3 or B4 iuehes 
long, clo?H*d at one enti, which hit** lieen fdleil with mercury and 
inverted in a KmaJI cistern or cup oi* mercury (Fig* U). The 




Fiti, 14. 

> 

I 

\ 



1 



ATMOSPHERIC PRESSURE, 



greater part of the mercury reniaiiiH in the tube, owing to the 
|iiv»ture of the atuioisphrre uii the expot*e*d surfiire of i\w liffuid, 
Ulc Jiverage height m1" the tnlumn hein^ neiirlv SOinehen. In tlie 
|>t»|mlar fomi of the iiLstruineat, th<* wheel han>in<'t<'r, the eisteru 
b formed by u reeurvalure ni* the tube (Fi|r. !'>); mi ihe ox|MhS4.'d 
surface of the mereury n flout is* 
placed, from whicii Ji thread piLsse^s I'^itJ- 15. 

over a puik^v uinl iiKives nn index /' ^•, 

whenever tiie etilunin oi mercury rLses 
or falls. The glass tube and con- 
tamed column of mercury are altu* 
gether enclosed, the iudex alone 
iM.'ing visible In the f<jrm fireit 
described the upper eml of the glass 
I I tube aufl nierenriul eolunin are ex- 
? « pfiwi], juid t!ie height «*f thi* mer- 
eury i» aseertjiined by direct tjhi*er- 
vation. 

The aneroid haronuirr (from i, n, 
without, and rv/^V;, mroft^ Huid) eon- 
f*iflt» of a rtuiall, shalluw, vacuous 
metiil drum, the sides of which ap- 
proach eiieh other when an inerwiae 
of lit niOf*ph eric pressure occurs, their 
chuiticity eiialiling them to rcceile 
towiLrd their lornicr ponitinii im ii 

^ decrease of i»ressure. Thi^ motion 

t. V ,"' is ^ uudtiplied and altered, in direc- 
tion by levers, etc., as to act on a 
IteKiinnrr. hand traversing a plate on wliieh Biirometer. 

an* marked numbers eorrespmnling 
irtlh th«»«e sliowing the height of the mercurial column of the 
orciinar>* bunanetcr by wluih the aneroid was adjui^ted* The 
Bmtnhm ^Mifomrtrr (from tlir name of the invent^tr) is a raoditied 
mtierntd, containing in ihe place of the n»und metal box a flattened 
faenouf* inlR' of metal iM-nt nearly t^) a circle. TheiH' Imrometers 
are alw* u**ed for measuring the [>reK!«ure in steamdjoilers^ ek% 
tTndcr (he mime of j/rrMjtnri'f/fiiti/fjt tln-y are s<j!d in indicate 
prvMiures of iw much n> TjOO pounds per t«<jmtre imh or higlier, 
Auen»id barometers, on accounf of thc^ir portability (they can be 
niMfie of I t<» 2 inehes in dinmeter un<l bj*w than an inch thickj, 
are handy ciitn pan ions for a>4certiiiuing the heights of hi Us, 
mouutaiiii^, and other elevutiou^. 



I 




40 



NUMERICAL AND PITYSICAL MATTERS, 




QUESTIONS AND EXERCISES. 

Give Tuli*8 for the coiivt^rsion of degrees C* intr* di^^-recB F., find of 
degreiiia F. iiittj ilt'jfrtHrs C—Nimie the degree C. iqiiiviikiit to tii}'^ F,— 
What de^ri.'e i\ is repTf»L*iited hy - A^ F. ?— Mciitioii thi* dejLrrre F* 
iiidiiat^'d by 2(J° C — Ci»tivrrt KXI"^ F. into de^rtcs ('.—How are vuria- 
tioiia in Htiiiosph<'ri« pn'A8iirti dt4eniiiut*d ?— Exjibiiii the coiistrmtioii 
liud mixlw of ju'lioii «jf harumi-ters. — In what riispHt doe** a wlitL'l- 
Imromt^tt^r dirt'rr from mn iiislriiiiu»ut in whii li IUk n-iiditigsj are taken 
from tlir lo|i of tin- ot>liiiiiii of nirnury ?— -Dt'scribc the constnictitin 
iitnl inod« of Hit ion of an aiUTui^l barumtilL'r. 

Rt'iafkm uf (he Volume of n (hw fo Prtfumre and to Ttmjterntnre, 

The volume occU|)itil by miy given (juatUitv of a ga.s Viirit-H (n) 
with variatitJiis in tlie pn-swure to whit!li it is Huhjectod; jind (6) 
with vsiriiitionH in itw tt'in|.KTatitr<". The juiKuirit of the vnriftliuif 
iti vnltiiiH.' Utt any ^rivi'ii rhiin|::e in, t-ithrr i*r tin w:» n>nflitir»nK i^ 
praclirjdly indi^penrlent of th« nature (d" tht^ ^a^ sitH/i' (within 
inoihTsite mnj^t^ nf j^rL^niire and of ti^tnjHTature) it in a|j[>hix- 
iniati'ly the siuoe for all JLfai^*•^*, niik'ss tluse are near thvir 
lii|iudyinj*r iHnnl.*^. The id>servetl variatioiLs take jdaee approxi- 
mately ill aeeonJaik'e with the^ liillowinjf laws: — 

Hoyfe'i^ Lfur. — When the temperature ol' a (juanlity of gaj* im 
kept eonstiint, the volume whieh the fras ^KTUpiets v Uriels hirrrndy 
as the pressure. When tlu* original preHHure i^ ihmlded, the vnliniie 
is «limini>'hecl Ui one-half ; when it is trebled, the v(duine it^ 
diminished t<i one-third ; when it is halved, the volume iw doubled, 
and *i **n. The pres**ure under whieh a gas is iaea.HuriHl is expressed 
in millimetres of mereury — thiit 18, by the heiglit in niillimetreH 
of a column of mert.niry cajuible ofcounter-bnlaneiiig the pres^nure 
exerted by the f^as. 

Charkji's Law.^ — ^Wheii the prt^sHure under which a quantity of 
gji« 18 meaiiiireil is kept eonstimt, the volume whit li the gJLs rH'cupies 
variL*s (iirevflf/ as tlie **al»solute** tempemlun^. The absrdute 
temperature is obtained by adiling 273 to thcol>servi*d temperature 
of the gim in degrei/s IVntlgrade- Suppow that n quantity of gas 
oeeupies 273 Ce, at 0^ C, then the ytduines wliieh it is found to 
oeeupy at the tern per jtturt*s in Column I. of the f(dlowing tiible 
are thost* ^iven in Cidumn III. (Vduinns II. itnd III. show how the 
volume varies directly as the abs^ihite temperature. 



I. 




II. 




1IL 


Temperature 


Absolute Teui 


iperatTiro 


Volume in 


inn\ t^t). 


( = 


- 27;i + 


t.). 


Cc. 


I 




274 




274 


2 




275 




275 


10 




l'H3 




283 


m 




sm 




H03 


—1 




272 




272 


— 10 




26a 




268 


— m 




24S 




24» 



Alau ocoiwiaaally called '*Gay Loqbv^j's Lrw/ 




DENSITY. 



47 



This table illustrates atiuther way m svbtch Ctuirles's hiw may 
be stat^dj viz., thiit the vulunu* <»t a ]jjiis iniBtTeusifd nr dimiiiishecl 
by jj,y ( = f»JKKit»(5) nl it'* voliiiiK' ut 0° U. tVir uurb tl« xrci^ (Ariti- 
gradt' tlitit tbr tt^mjHTntun* <jf tiie pis is nuKt'il or lowtTtvL 

Siantlntd Trnip* rfi/ttrr irnd IW.Hitur't', — Tlu* teitiiieniliirt' of C 
siinl tilt' jirt^sure «»J' liU) Mm. are trrmej ainnthrd ffrnprrfifttrr nud 

It i!^ fVefiuciitly ncci'Hsiiry to Liik'ubite,, in arrimbiiKv witii the 
f»»rt'}^*nr»^ Iaw8, wbut the v^jIuhkm^' si t|umitity rjfirjLs would bmniit^ 
timler lU'W ctmriitioiis fd' |>rt/f^ure juul tif t«nnpenUure, when its 
volurae iiuder fibittd eiUMlitinnH (firiiiiual eiuifbli^ns) it< known. 
Tfie eahniluliuu Iwbii li in idieu tt'nn**(l ^'cnrrei'ti<Hi for pressure rnul 
tempemture**) can be niiide in all 8Ueb uu*e*H in tiernrdiuice with 
the frjllowin^ fiiirly ((bviHiirs rule:— 
Taking' tbc known vidunie^ 
(I I Multiply by the ori;j:inal presHure, and dividi* by tbe new 

rtUre; uJid 
(2) Multiply by the imhv absolute t^Mujierature, and divide by 
the original al)*^idute ttMupeniture. 

~ ^ Krft mpk ; — A q U« « 1 1 ty < >r h y < I ri i)i;e r i < k ;< • u p i es 2 K i 'r . at 2 7 O. 
75(1 Mm. Find iti* volume at W iX and 7Ht) Mm. 
Wt^ have* here: — Known volume ^^ 2**0 C\'.; Oripnid l*re,ssure = 
750 Mm.; New Prei^sure = 7 HO Mm.; Original Absolute IVnij^era- 
ture = 273 + 27** = aOO^; New AlJHolute Temperature = 273 + 
P 0« = 273*. 

^K Proceeding an indicat-ed by the rule given above, we get; 

^H nil 

m "' 



750 
260 X X 

780 



273 



300 



- = 227.5C< 



JMrmty, — By the density of a nubstjinee we understand the 
number rif unitH of nnijw of the !<ubrtt4inee which occupy ti unit 
ofHpaet*. The gramme and the ntillilitre are lubipted as unit of 
nuiHH and unit of ?<|»ace re?5pcctivi'ly, and tbe density of" ii suhntsiinee 
IM then re(»reHented by the numlh-r id" gruinmeM of that Hubt^tance 
which (K'cupy a inillilitre. At 4** ( Vntigrade one gramme of water 
o<;eupi«»Hrt millilitre, hence at thi« temperature the (!enj«ity of water 
U — I in terniH of the nhuve units. 

Uefufirr fhnMifieM or Sp*r{fff firfit'itiej* tif L'uptifh and of Solids. — 
llidativo fbMi»itieH (or i*peciHc gravitie.-*) are the di-nsitieH of other 
>Mib»*t««ee>* HH ecMiipared with that fd* wime snbitaiH-e wbielj is 
ch'weii af» t^Uimbinl. WaliT at 4^ <'. (with dennity anHunu^d =• 1) 
woahl l>r a th<»orfticuliv perfect standard for the compariwai of 
the rehith'i* den^sitien of other li»piifL« and id' Hiilidn. At 4"^ Oenti- 
Iffaile wat4T in i%\ \{h maj'itfwm tfruxift/ poittf; that Ih to njiy, any 
iriven (jiiantily id' water oei Ufde.H at thiH temperature a smaller 
volume than it doe?, at any teEniKcrature above or below 4° (\ The 
MUnLlN]*rH repre*^^ming llie relative deiiiitie«> of ^lidn and of I iquidn^ 




48 NUMERICAL AND PHYSICAL MATTERS. 

in Utiilh <>f tht' uniLs and ?^tjindard rt'ltTred to tihovr, * w^mld Lliua 
sliovv hi*w iiiitny ti nit's liriivii^r or lighter the rt"S|H\'tive Hiihstiinn-j* 
nn% hnlk fV>r iiutk, than Wiiter at 4° U. ;<»r, what is the ^aine ihiiig, 
huw insmy ^niiinnL\s of the reH| »*.'!■ tive rtuh.Ktaaue.s oeeupy the watiic 
rtjiuie iu^ (*nr ^^ranjine u\^ water ut 4^ C (/*c. I aiillilitre). 

Reltttive UffutififH nj (ttuftn, — The relative tlcrisities (<>r j^peeifie 
gravifies) of other ^ase,*^ are UMinlly eonipared with the density of 
hydn»gen, the lighti'^t known gas, whieli is arhitrarily ehnsin as 
slsmchml, with density ^L (Fortnt^rly air was the .standard 
ado|^tfd witli density = l.) In t>rik*r to Ik; in ii|Hisitioji to tonijiare 
t\w dcnf^ity of'aay given gaa with tliiit ol'the standard^ it in in.n'i'j*,stiry 
to dettTiniDc the nja-sHen of «Hjua! vohimes ai' l>oth gai<e?«, umler 
the Banii* etjnditiuns ni' pri^^nrt' arid of temperature («"• p. 4(i, an*l 
the Seetitjii nil (Quantitative Mea?^urL'UieJit.s). The mnaberH ri^pre- 
fteiitiiig ihii rehdive densitii'?^ of jras >* >ihow how many tiairs heavier 
the respective ga-^es !iri% l)iilk tor lndk, than hydrogtni nndtT the 
same eondithiai* nf pressure and of leinixTaturr, or, wfnit i,s the 
E^arne thing, how njimy grain iiieiH of the rt^H|»eetive gasi's cHCUjiy, 
under the winie eonditionH i»f pressure and «(l' t(*mperature, the 
t^iame space aa one gramme of, hydrogen (Lr, 1 1. 1 litri's). 

Vnpf/r I>rmUif, — This term is apphi'd in the rehdive den^iity (or 
speeifie gravity) of the vapor in the ease of any snbstariee whk'h 
is liijiiid fir solid at ordinary temperature's hut which is eitpaf»le of 
being convert<?d int<^ the state of vaf»or, withtnit undergoing deeoin* 
position, by a sufficient ristt of temperature. Vapor denj*itie*« are 
thus strictly conijiarable with the rehtttve densities of g»se«. {See 
iJie Section on Quantitative Mea^^urements, ) 



QITESTIONS AKD EXERCISES. 

Define nrvyle'g hiw,- What thvcs tho vohinio nf a litre of liydroirfn 
nt ordinary utuiusjilurie pnHHtire tNtiimir wlivn tlie pn-x^ire isilouliled, 
lull vihI, qniiflra pled? — Meiitifni to wnys ii» wirirh \\w roirulnrity km»wa 
AS (Imrlea^a law may Ih' stntftd. — How is tin* atiinbcr wliieh rtjjin'iwnts 
Uic nbsohit** tefufK-nitute ohtiuncil?— Ik-(ia** Mturidaoi t«'mpL'rntaii» and 
prf^H«iirt\— What in the rule for '*ci>rrt'^tinfr*' the voliiiiir of » jtAs for 
change ill t<'ii»(»L"ru(un' mid prvsflurf? — What do yoa anderHtamJ hy tlif 
ii»rrtm dptisity, rehitivc deiihity, viijmr density?* 

7%f^ ntufif'nt M rtrtxmmtfnM fa rt^ail tht fotfotvint/ jmrnfrmphjn nn 
the iirnerni fYittripirj* of Chnnltyil Phifo^tfi/rhif Cftrtfulhj onrr or 
htirr, thai to ntu*iff (rj-fH-nmrntfttttf, if po^tj^thfr) the *Hriyer(fin*j pa^f^^ 
tftnrtfitttf /ft fittrt reniiinrj over the Grnrrnt /ViVwf/i/^P ffvm time tn 
tim*' untii thrff itrf t/iftntttifhft/ ertmprrhr tided, 

* Xot4\ however, that thu KtioulHrd teni|ii*mtttre adopted in pmciioo 
ffir compilHiur ^tw^'iflr Ki-HVitifH U not 4** t\, hwX STi'' C. (T?** F.), {^n 
the Sectiuii on Quuntitalive Measurtjniouis,) 




CHEMICAL AND PHVSICAL CHANGES. 



49 



I 



THE GENERAL f'RINCIlM.E.S OF CHEMICAL 
PHILOSOi'llY. 

The Science uf Clieinistrv in'al^ oC a piirlifuhir i'hi*H of cbangea 
tbiit uiatler uiuitTj^oe.s, TIji\h4' rlinn^rs rt-Kull in tin/ iunniitiun of 
lU'W rtulihtmiciH — tluit in, <*j Hubj*UyiL'u>< wliith art' difUTf'nl in cnm- 
(HM^ition luul (jropertien iVom tiie iniitt'risiLs out of wUirli llu-y Inive 
\mx%i prtKllKtiJ— and tin y are loiinnrnily «_'iiJlLMj elinnivnl chttfHffn, 
Huch cbaiig^i*^ may 1k' tln^ ri>uU of natnral ngi-noies cnily, an in 
the gniwth «»f (ihuits anil aiiinialr^ in 1% wholly itahiral ntiitf, and in 
iJie tnLUi!it«>nnuiion}« that the iniiniiiiiitc niat^TialH of wlikh tbt' 
eiktih Is amipim^l mnU'rgo owing to chiuatit- und otlirr inflnrnco,**; 
Of thf-y ni:iy W directed ainJ, wi fitr, contndled hy hninan ii^eucy^ 
II*, furexiimpli% in tho prtxretsBes carri**d nnt in thr rin uiua! hibom- 
triry or niaimfuctory. 

iitrfnicti/ nnd Pftf/niifi/ Cftangt-Jt. — Many well-marked, nr ttjffU'fif^ 
CH^M^ of chfuiioal change arc eoi^ily recognized a« nnek. Some- 
timf**, however, it Lh dittiridt, and neeasionally it [^ luA jmivHiWe, 
tfi rtH'ogniice whether a partienhir 4 hange really is a rheniica! 
change, or whether it belongj^ tii the ela.^ fif plieiicnnena eidletl 
phy^tieiil ehangt*?*. The exinteiue f*f any uneertainty ari?«e*< froja 
the dirtienlty in jiroving ernuhMivelv whether a new .snbstaiire has 
l»i'eu f»ro< hired or not, together witli the fart that it is not an alto- 
Ifetber vii^y matter to defnie strictly what eonrititntes tin- formation 
of « new njbstanee* Familiar examples of physiral ehanges are 
(lirniHhed by the trans forma ti on h of solids into the li<|uid xtate {as 
of ice into water) or of li<|nid!* into the stjite of vapor (as n[ water 
inUi wteiira) without any ebaiige in the eompopition of the -sub- 
sUneeB, In typlial easej^, the oecnrrenee of eliemieal <hangr nniy 
u^Uidly be rerognized by the aeeompiinying phenomena ebaraeter- 
jjitk" of Hueh eliange. Two of the ino**t ini[»ortant <*f these jdie- 
niituimii are: — 

L Thr *li*tsftptarmijcr uf (ht propertitJ^ qf tkr jfitb^taner or tfuit- 
tttutrfji trhi**h tnkr parf in thr rftitriffr^ an*l thr fftrmntifm of a ftftr 
nihHffinrr ur 0/ ttrtv wftfmtnm^ffi pmnejurhnj o/hrr proitrrfirjt, 

A miJ-fttrr of free oxygen and hydrogen is still a pas; water, a 
rhrmimt rompoumf of oxygen ami liydnigen, is a litjnid; here is 
(rrt^at alteration in [»ro[M.'rti<*s. IiHlinr is only slightly soluljle in 
WHtrr, ffirming a brown-eolored •u^lulion, anrj imn is inst*hible ; 
lait whi»ri iodine ami iron are ehrmicath/ eoaduned, the priKluet i* 
very wduble in water, fonuing a lig[if*grern wdntion which is 
utlrrly unlike iron or iodine in any one of itw properties, and in 
which tlie eye run lieti'et neither iodine nor iron. Tartarie aeid 
and »iidium earbonat<% mixed together in iiresenee of wator, givi* 
ri^ to other and wb«4ly «liirerent vhmtirat mmpmindu, the <»rigiiml 
«abiitjtljee<» havhig interacted and formed fresh eornbin; 

4 



mm 




50 GEyERAL PniNClPLES OF CHEMICAL PHfLOSUPUY. 

Siiud^ ^ugar, ntid buttur, nibbeti togetlji^r, Corm n mrrc mirturet 
iVom whieli water vvoiilxl t'Xlmct tbe !«ugar, ami etlii:*r disscjlve out 
the butter, Iwiviag tbe siiruL Tbese exjutipb'H illuHtriit4* bow 
chrmiml iictioii b fiintinguiHlied, juuiiely, by priMlucing an entire 
cliinge of j»n>iiertiev'^ in tbe re-oultin}^ substuneeH. 

2, The fjtvimj out, or the a/tJ-torjtftfm of hrnf, dttrfftfj tftr rhiut*p\ 

Wht!n eoal or a i.'uiidlu IjuriiH in tfie air, Lbe earhi>ri [*rerteiit in 
tbe eoinlmsiible material ujiik',s wifb the r»xy^en cil tbe atmos- 
fihere, witb tbe evulution or givin^^ out oi' heat. Sultsbur, pbo»- 
|ih«^rii.H, eert^iiji metiibs suib its nlaj^^le^^ium ami ziiie, m^ well a» 
many other ^ubstaneen, likewis<.^ burn in the air, witb tbe evolu* 
linn id' beat. Therto instanee.^ ol' e«inibuHti(in are all exami>le^ of 
ibeinieal aetion, and are reudily distinjiuisbable a?* ,^ui*b. 

Bej^ideslbe twn iinpfirtiint jdieiinineini n<>t4'<l nljnve a^ ebarueter- 
is^tic of ehemieal ebange.^, it is furth* r h\ be obn^-rved ibat clicju- 
inil eoiJibiuntinn tak*^ |dai*e between tln' hnbstanee.s wbieh enter 
inttj reaction (interaet) in eertain ^letitilt.^ |*rii|»urtions by weigbt 
only, and not Hinijdy in any proportlou.H in whirb Ibey may, by 
cbanee ut by ioti'Mtbm, be TinKe»l tiit^ether. Tbe rjuite general 
n-ii^ularitieH that have been ol^rrved in eonneetinn witb this matter 
are disM^'iiJ<Hed below under the Law?^ tif diesuieal < 'ojublnation. 

Eff'f7%t'nlH ftfui (hmpoufiffy. — In nnnlein ebemi.Ktry tbe term rfo 
inrnt iH applied to any nubstanee wbirlj bits mvi been hloiwn lo be 
euaqiound — -that is^ to pci.-<seA^ a <•*» apiwh«i nature. The word ia 
sirietly res^Tved for those sub??taneeH wbieh tbe ebemist its neither 
able U» break uj> into two or more f^impler HulMan<-eH, nor to pn»- 
tluee by tbe union id^two r>r more sini[*lrT KubMtanees. The ele- 
ments are the .-^irnplei^t forms of matter known. The term mw*- 
/iof*rt</ is applied to all .Hub.-itaiices the eomjiot^ite nature of whieli 
can be [*roved* The proof may (NUiHiKt in breaking up the eom- 
pound int4i two or more niniider MulKstJineeH by >*ome methotl of 
df^nmptrntifm : *ir it niay eon^ist in l»uibliii>f up the e"im[>ound \'ttm\ 
two or more simpler Kubstanee«, by eaiL^ing thej^e t(i eonddne — thai 
if*, by afTeetin*; its Mt/nthrxi^,^ 

Up to the prei«.'nt, about 70 element** h»v«^ Intm djKt*overe<l, and 
more or b'ss minutely examined and def*<"ribed. Of IheM' cle* 
ment-^^ ab'Piit 40 are either of prartieal inqiortanep Ibemselvc^^ or 
they enter into the efunpo^^ition of eompoundi* which art^ of prae- 
tieal importuuee. All of the en(irmoU>* nundier of ehemical com- 
pounds that have been [*re[»Mred antl examined are c«»uil>iuation» 
«d"lwu or more of the known elements, 

Chemirni Afhttittj is tbe name ajiplied to thsU tendenev exhibited 
by certain elementary and eimitiound Mubstanei'H to enter into 
fresh euuibimilious witli tme another ^o tu* to form lu'W eonipounti**. 
The name i*^ Hf»metin»e!* applicHl abH<i to the ti^mleney of subr*ta net's 

* The wopl Kyuthrnif ia frtan if»r#<in*, mntheMUt a putliaK together: rtw«/- 
jynLi, n U^rm ufieii ijiji'd to de^^igimu^ thu r^rvertiK^ oiH*mlion uf def?omiHifii« 
tioii, h from ittA^fut, auatttd, 1 rvsolvi?. 



LAW OF CHEMICAL COMBINATION. 



51 



to remain foniUinitl atU-r iNimbimitiun, with the formati«Mi ul" new 
oomptmncb, has Uikeii [>lure. 

I^iWA of Vhemkal Combinafmn, — Gheniiral ctmihinatinrj inkva 
place Ut'tWivii di'tiniU/ qiiantitiefi tif .sul>Ktmiees, The more impor- 
tant fiuiintitutivc relatJt>ris are exprensetl hy the ftjllovving laws:^ — 

yytf Law of (hmtant rrupartitnix Miite?^ that the s^iitie eheiiiiral 
conjjMKirKl is always eiiaijjosed of the nuik* c leineiitj*^ aiiTrTfmT 
lhe>«niement^ are pres^etit in the comjuiuinj in the Kjiriie relative 
pnnMirtions hy weight. Thus any jmre sjuriaien i>f eonntifin Kilt 
b* found on almly^*is t<> eontiiiB the i^leaienls sodiimi ami rhiorine 
fjnly, and the=Hi are arwoeialed vvitk laeh otJier in jirnpurtionH of 
22.><H |iart*^ l>y weight of Hinliuni t<j iifKlH partn l>y weight id" 
chhiriiie, Kiniilarly any jiure Hpeeimen of ?*ulphurie aeid rontaiii-s 
hydrogen, wulidmr, and oxygen, a-Si<<x'iatod witli one another in the 
projHirtious of 2 parts liy weight of hydrogen to aLW'i of sulphur 
and na.52 of oxygen. To the general statement of the law of 
conMinnt projKjrtions, it may be added thid the mt\m of (or quan- 
tity of matter eontainetl in) any eofn[»ound nuhstance is equal to 
the »uni of the mjLSMes of its e<inr<tituent-^. 

The Imw uf M^iHlplt' iVopnrfiftufi. — The name eleaients are tiome- 
Ujne8 capable of uniting with eaeh other in niore than one |iropor- 
tinu by weight. The law of multiple proportions Muteii thut^ when 
thin is the ea**e, the severai qnaniitie^ of one of the eteineiits 
which combine U* fonn two or ntore toinponnds with any given 
quiintity of the other element, stanrl in siaq^le midtitude relalionw 
«tber io e»H'h other or to mme conuuon suhmultijde. Thus in 
the two oxidei* of carbtm there are contained ; 





Parti* by weiglit 
of Ciirbon. 


Purte by weight of 
Oxyg&H. 


Carbonic oxide . 
Carlpoidc iinhyiiride . 


12 
12 


m 

32 


and io the two oxidcn of pho«ph«ruH then? are contained : 


^ 


PhTtn by weight of Purta by weight of 


PhnHphomiJji anhydride . 
rii*.»^phoric' ardivdriile 


52 
62 


48 (-16k3) 
80 (-15y:>^ 



Thf Lntr ikj (ffinrrnvt \'o/umrfi ntJiteH ibsit when ga^ncs eorabiiie 
with one another, the volunicH which unite ntauil in a simple rela- 
tion to each other aotl aI»o to the volume of the product when 




62 GENhllAL PKIS^CIPLES OF CHEMICAL PHILOSOPHY. 

this JH ii gaseous^ siihstiiiK'e* Thr Hiiii|»ti' rt'latioQH <it" tbi- vr*Uiiiieft 
id' the corrilHnin^ ^^si^'t'S la eiirh ollu^r and in the volumt- •»!' the 
[mwlurt in n IV'VV cawea illustrative of tliii* law, art; oxbibiied in the 
following table: — 



Voluniea of CutabfnLng 



ITytlit»^i*n 1, (-lilorlnu 1 
Ilvflro^'eii 2, Oxygea I 
* arlHHiit ftxide 2, i Jxvgeri 1 
Carbciuic <»Kide 1, tliktrita* 1 



Volume of producL 



llvilrncbloric acid 2 
\\ Titer vapor 2 
( arlM)iui' sinJiydrido 2 
I'huf^guii 1 



A* B. — In each of tbu ff>re]j;<iin^ c^^'s it in net'esBitry to aHsume 
tbiit the voluriH'rs fif the coinbiniDg ga.*^e8 siad of ihi' product are 
NH'aMind untliT thv xunu- rniidiiinus of pressure and of teriipera- 
tari'. (Srr p, 4(1) 

The Affmiic Themij. — t'cituiii tbt'on^tical coiiroptions which 
have hinre developed iritt) what ii* now nil led the Atooiir Theory, 
were first eniployt'd in eheiiiistry liy John Daltnii. a Munchesnt^^r 
L'beiuist, in exphaintion at the regnhirity which Im?^ already been 
no.'ntioned its the Liiw of ^IuUi{>!e l^roportionw (j>. ♦'>!). ThemoHt 
ijiiportaiit asHiioijiyoiis of tlii.s the^iry ;ire wtided in ihe folbiwin^ 
panigraphH. 

Matter of all kinds is aswumed to be eompoKed of rxtreinely 
nunnte, indivii^ible partieles. These pfirtielen have lieea eulled 
(tftifti.t. Bin^le iitoiuH are bo .small as to be eiitint'ly beyond onr 
powers id' observation, even with the aitl «if tlte nirivst powerful 
ni»gnifyiii|j: Instruments. It is iL'^rtunied that eaeh element eon.sista 
of atontH of one kind only, tht^ kind, however, hvin^ diflen-nt for 
every element. Ever\^ eoui|H>nn<l, *ni the other band^ in anHunied 

eontain atoms of at least two diilerent kinds — that in, atoms of 
bt least two different elements — e<nni»ined lo|felber ebendcally. 

F>tiniiites have been made as to the pnd»able shape, si?-(% and 
njaxrt of attMHs. At liest, the^e juiist hi' regardnl as approxi- 
mations oidy. Experimental evidenee jioint.s to the atoms of 
diflerent elements poKsemng very ditferent vftijjhh. The al>sohite 
ma«s is not known in the ea»e of any atom, but the rath* to eaeh 
other of the wri^htn of the atonjs of ditferent element>» ean he 
ch'termined with tieeuraey. A H*»ries of jiumlM?rs whieh repri^'nt 
the rcfnfivr wrhfhtn af i/if (ftjfrrtnf kintU of afoinj* hjus aeeordingly 
been dniwn up. Tio'se nuniberf* are rdfatirr atomt'r treiijhh, and 
arc iu* a rule dimply ealleil oiomic trritfftfs. They willl»e diHeus<»ed 
fiirtbcr on. 

The ir^^re|nitc*9 <»f atom* which are pnKluced when two <»r inorv 
anlikt* atonm eombine ttigether to form the Bnialleat piirtickm of a 




A VOOADRO\S HYPorUESIS. 



53 



N 



ifi^^und sub«tanoe^ are ciilletl mitU'rrfJ*^. * The most nimjily 
duij^tituted molecule of a eoniiKnirnl stjl).><tiirire rfim'eiviil»le iiiuat 
iiece?*f>arHy eoiiMist of at leant tvvii unlike :ituuii4. The luoleeuleu 
of earlx*nie (txhle ure heileved to j>(>s,st\Hs ibis siiu|i)e coi^stitolion, 
and to e<*n»isl eit^-h r>f one atoiu ♦»(" ejirh<Mi und uiie atom ufoxygeu. 
The next simplest euueeivahh; et»u.stitutioii i'ur the moleeuU? of n 
eonijmuiid \^ that it sh*iul<l eousist of three atoms. In this cjihc . 
there are two jNissihilitii'^: — 

1, All three utnuiK may he dilfereut ; nr 

2. Two atom?^ may be of one kind aufi oue of iriiother 

The molecules* i*f hydmeyauic iieid are regarded iis i Must nil iug 
the fir?«t of the^e pos!*iliiHties, and as toiisintiug eaeli of one atom 
of hydnjgen, oue of uurhoa, and one of nitrogen. The moleeuU^i* 
of earbonie anhydride* are regarded as ilhistriitinii: the w^'oml, and 
im coniii.Htin^( e^ieb frf one atom of tarhon and two of uxygiiK 
The moletuler* of many suh^tauees* are stjpiKJHed tti pren^Jt nmeh 
great4.*r complexity tlian these. 

If w*:* iii>w eoinpjtre earl)ojHe oxide and earhonic anhydride in 
light of the jitoinii" the<>ry, we pereeive the eharaeter of the ex- 
[ihination aftonle"! ity the tln^iry for the oh^erveii fiirts ronivniing 
the quantitative ridutioas io eaeh other <d* tiie eleineat^ whieli form 
the two eoinpt»und.H (p, 51). t 'artmnic anhydriile eontains, for a 
given weight of carbon, exaetly twice as mm h oxygen as earbonie 
uxide dot^. Aeeordiijg to the atomir th<'ory, this is herause n 
moliM'ule of earhiinii^ iinliydride contains I'tir om* iitont of i-arhon, 
two atoiiiis of oxygen, while a inoleeide ol' earhojiic *>xide i unliiins 
for one sit4»m (»f carhon, only one atom of i^xygtMi. 

Amtftuliut^M flt/iififhntU.^-W hrii the facts which fiufl exjires^ion 
in the L:iw of tliiseous Voluines^rcterring, as tlu'V do, to the 
combination of gjines in nimple raliomil f»rof>ortions hy volnmr to 
form pnitluet-s whone volum /s are simply rehited U* those of the 
gHMM which combine (p. ol)^are considcrcil in connictioii vvith 
the idea of combinatioa in simple atmnic proportions according to 
r>alt4ai*» atomic theory* it heronjes evidi-nt that there must lie a 
Kimple rehititm l>etween the volumes whit h gases occupy jiml tlip 
numl>erT4 of molecules pres^'tit in thes*» volumes. Tlie uiiture (d" 
the relation in exjiressed hy the Jlypothe^iii of Avogadro, which is 
iiHually stated ils to Hows: — 

i'^fua/ voiumfJi of ttlt ifitnrn^ tutdrr (hr »amr conditlfmA of pretmurf 
ami uf temper ftturr rntffiihi thf Mnmr ttutnhrt of mttffrith'A. 

In order to bring ihiwvery sim|de hypothesis inl<> harmony with 
the oliHiTved lact^, in all easi-s of combination of gases wilh eaeh 
other, it i» nece^wirj^ to make the furtJor itssuinption that even in 
ilw clr-fnentAfy giiHes, hydrogen, oxygen, lutrogen, and ehloHne, 



'The word H^ulrenh Ih ulrm ftp]ilii*<l, an will apiwur lati^r. to j»^^;re)i»atc« 
€on«Ulhii; of two or mort* like iit^miH. A nutuberof oh'nHMitiiry g»iH« 
• And VApor ant >iiip|ios«^| to bo nuide up of imrtieli^a eausJfttiag af ^uch 
kgruupi of liki* iiUfiuii. 



f>4 aEyEIUL PRLWU'LiLS OFCUEMKAL PHILOSOPHr. 



tin- [liiriirk'S <ln iiol i imsij^t nf .iingle jiU^uih, but <«! juiirs of /ijfc^ 
iitoui^ iLssiX-'inied toja^ethL*r U) Ihnn mo/rcti/r^ In il lust nit inn «*f 
this tjutttrr, the cjlhi^ i»f tin* rnuiliitintiou uf hy(ln»fj:en with rhloriiie 
furniHh(!« a troiitl example. Otn' viiJtaiie «jf bydmc^eii i'i*inliines, 
as we have »eeii (|>. '>2), witli one vnliane of rhlorine tn t<»rui two 
voluHieii iif hydnit'lilnrie aeid g:isJ Tlie v(4unie of tlit' protiiK't 
in iiere tkaihk' tliat of either of the eujiHtituent ga^e?*, nml tkere- 
fore, aeeordiiij^' Ut Avogadro's Hyi>otlu^iH, it ctmtjiins Iwlee *^ 
mnny inolerules na either of tln>se vnlmiiej^. IJut every aioleeule 
of the resultinjr hydroehlorie sitiil gas contiiiiiH ftolli hydrngi'ii ami 
chlorine, ami, a^ there are twice as tjmny nioUxuU^ of it ^eaeh 
cuntidning hydrogen and ehloriiie) as there were of the original hy- 
drogen nr of the original ehlorine, eaeh nirdeeule of the two latter 
giiHet* nuLst have undergmie ciivii*ion into two [»art.s, sjiid miiiHt 
therefore have eonMisted i»riginHlly of not fewer than two atrnan. 
There in evidenee from anotlier Miuree thut the nitdeeideM of the 
elementary ga>w'?^ do not eoiisi.si of more than two atom.*^ (ji. 5S). 

MoWttlijr Wtiff/ih, — If, as Av<>gadrn\s Hyimthesis^ asHUna*?*, 
et|ual volumes of all gii«es contiiin, umler likeeomlitimiH, the name 
mimlfer u{' moleeiiles, then the ditfereneis in the weights of e(]Ual 
volumes of the variiais ga»it^^ (as ^^disi^rvinl in making dttermitnitionH 
cif their relative densiti(s) ean only l>e aeeounted for hy diflerenees 
in I he weights of the respective moleenh's of whirli the dlllerent 
giLses eonsist, Aeeordingly tlu* determination fif the weights of 
vi\un\ vohimet* of diH'erent gaises (under like eonditions) shonld 
ruriiish rnunlHrs whirh ntand lo eaeh other in the nitios of the 
weightrt of the moleeuh s of the r*'S|ieetive pis<\s, (iut this is tbt* 
determination whieh is aetually iiuitle in asi'ertaining the relative 
dcnsitii^ of pises {[k 4H) ; heiire tin* nundters reprt\sfiiting the 
relative densities of gases lead direetly fo the rehitive weights of 
the moleiiiU^s of the gases» 

As already stilted, hy(h'ogen i^ adopted as stnritlard, witli tlensity 
= 1, for the eomfuirisi^n of the relative densities of other gases 
{\K 48). For the einnparisoii of the rehitive nioleenlar weiglils 
of gases hydrogen is aim adopttHl jis standard, Imt with moleeiiiar 
weight = 2, Henc*e, sinee the rehitive mftfec uhir weight in in all 
gaws [>rofMirtional to the rt:»lative density, the relative mohn^uhir 
weight of any gjis is e\|>n'ssed by a nnmher whieh i» dmdiU^ that 
whieh expreit»e« ita relative (h^nsity. Thus we have; 



RvltttlTc Detiiltjr. 
1 



UcUtlvc Molc4^lllAr 



Hydrogen 

Oxygen . . . . If). 88 3L7fl 

Carbonic anhvdride . . 2h«85 48,i»7 

Water vapor' . . K.i>4 17.H8 

and soot). Tlie numliers desipnateil tvbtive moleeular weights 
ttlMive aR', aw tt rule, siiu]dy eiiUnl Mohrufar WrUjhh. 
* All measured under like coaditiuus ofpreaauroaudof tcJnpcmttirQb 



ATOMIC WEIGHTS. 



55 



I 



There Jirt* miiiiy suUKtarR-er* ^f vvlnrh tin* itHiliMuinr weights are 
unkiKtwt^ iMx-nutH' ihfv rauiiftt Im- nltt^niKnl in tbr ^lUHfous state, 
an<l iMTjiUHf i^iTtuiJi t'ther kiiovvu inilhods oi yicdeetihir wtjj/ht 
ili-U'miiniiti((ii canntit he a]»|iHed t<» them. 

iirtimmr Molrru/f,-^\utr ehrjiiintl jmrpowes it in often coinetiieiit 
U:» deal with ^U'tinite qiujiitltii's <>t Hut)stiiiJtes In [rriiiiiijiis (liul <it' 
Cfninie other detinite wt^ights wmld he eu»]»lnyi^«l), thest^ tjujintitieH 
being bju^ed u|Min the moleeuhir wei^htnot' thej^iibstames. When 
Uie number which ex [>res;*es the iiifdeeulur weiirhl of iuiy substunee 
i* cot j .Hide rt*(J i\s representing' tjiul wini*.* number ttt gnniiniefs, this 
quantity h e:iHed the '*nioleculiir weijt^ht in gniuinicrt" ot the 
ftubHtunee, ur, lUfjre s^hurtlvi the t/rammr tmff*Tuff. TliiH \t> iin 
ini[M»riiint quantity with respect to em^i Muhstanee. (('ompiire 
pp, 50 and ?j9.) The grainine nitileeuhj of hyrlr<»>ren weighs two 
grttJwmeB, 

Atomic Wri^jhta, — If, in ureonhiiue witli tlie iit*«niie throry, 
inohj^'UleH are aggregutt*^ nf aloinet, the weight of any given niole- 
euh' must he made up of the separate weight*ij fd' the atoni:^ whieh 
compose it, and nuist, therefore, be eijual iu the .^unj nf thene 
Kt'punite weight**, ilenee, if it is posHiblc to aM-ertain by any 
melius the Vxiwh of atonic, and tbe nundw^r of eaeh kind, whieh 
go Ui eonHtitute the nndeeuh^H of any eian[M»uiid it should like- 
iri^ be |:»#)S.sihk' to ii^ieerlauj the rehitive weights of the atouiH of 
each kiinl from tbi' relative mohrnlar vveitfhti* of the eiunp^iuink 
hit^i whtH*!' eonifiosilion tfiey tnttT, It ha>*, uk a matter <d' faet, 
lK?en found |Kis<Hihb' to obtain a ^f-reat deal of intormation with 
re«|K*et tu thewe ijiatt4'r>*, Tht- niesjUM liy whieh this intWruiation 
TH ol)iaim*il may he -stjitt-d a.H IoIIowh, 

K Uy joaking une id'tbe ordiiiiiry niethods of ehemical analynisi, 
the kiiiil^ of atouj!* present ia a eomj»>und ejin he determined ; 
that U, the |ire>*<*ni'f^ of the psirtiriilar elements of whieh it is eoni- 
|K#Hi'd «'an \h* ree<*grusa'c|, imtl the al>sene<* of others vww be (>roVfd, 
By uie}in8 fif methods id*i|uantitative analysis, the i|uantity of eaeh 
element pr<'?(ent in a given i oai|iound ean be determined. 

2. Whi*n tlie reHult,s rj'ipiantitiitive analysi-w are st» tabnisitt'd a.** 
Ui »h»tw the wri>r|it i»f eaeh elemmit whieh is prest^nt in thf)«e 
quant itii*!4 of compound snbstjinei's wbieli bave already been 
<iem-ritN«d an their gramme mnb^nles, it in found fhiit the 
grammt* niohnailes of ditler«^nt eoaipt)nn(is containing one eh^inent 
in fvmimon, r**inlain ♦juniitities of tlmt clement which are related 
Ui eacb other in a vcrv simple tujyuier. The nature »*f this Him|de 
ndalion is exhibited in the subjoined tables. In eat h of the>ie 
iuhirs tlie nundHi^ given in C'obiam Jh reiiresi-nts the weights in 
gmmtocf* of the Hiil>stanccs named in t'olnmti I., wijich fwetipy, in 
tbf gjif»eous state, and under tikr I'oudition.^ of prcs^sare and of 
t«*nipiTatun^, the Matui* volume us twogrammchuf bydnjgen, Tht* 
nund>er>^ given in Columns Ell. and I\^. sbow tire eou»[>o«ition, 
by wcijrhl, of the (pmniity ofeiicb mibstance which ii^ set down in 
Column II. 



56 GENERAL PRINCIPLES OF CHEMICAL PHILfJSOPin 




L HYflRLHiES, AND llYDROnEN CoM FOUNDS. 



Nftmcs of KUbritiiuri'» and we!^lit<4 
tliciii, in ifrtiniines. wlUuh, <x'ruij>\ in 
the t-jiiMLtuiH n.lnti' iiihI iiixJiT like niri- 
lUtlMllS ill"? i^UlOO VnluiUL* a» lwt> 

gruiiimiiA of hydruKcij. 



I'lihjmn J-. forUHin tlit-- uncleruoied 
weigliijii, in |,':rAiume!», of— 



Wi'ights 

Hydixn'lilntic acid . - . 3^.>.1H 

Jlvilrobroniie acid . SiK'M 

llVihoK^fi '2M) 

WWr I7,S8 

Hyilro^en KitlphifJe: . . 33.83 

Aniinuiiia , , . - . . 16.93 

Hvdro^en |»h(>4phide . * 33.77 

Maivli Kfus 15.91 

i >k'ftanl ipm 27.82 



111, 
Uy4n>i{i;ti. 

1 

I 



Kthvl nlt>«j|iol 



Ktht*r 



45. 7Q 
73.52 



10 



ULber Elementa. 

Brtunine . 

Oxygen . . 

SufpLur . . 

Nitrogen . 

In tij( »n . . 

('nrlMin . . 

( ruHkHi . . 

\ ( )xyg»^n . . 

( t iirhm . - 

InxygtMi . • 



11. Ox YUEN, AND OXYQEN COMPOUNDS. 



1. rr. 

Nauius. Wel^-htM. 

Wiiter , . 17.K8 

t'ttrbcinic oxide .... 27,79 

Oxy^L-n , 3L76 

OirHoiiif nrihydrick* - , 43.67 

Hul|>Iim*>ii!s nnhydnde (13.59 

Sul|tliurii' sndiyllrnle . 79.47 

NitricMicid 02.57- 



in. 

15.88 
15.88 
31.70 
31.70 
3L76 
47.64 

47,04 



IV. 
cnher Elements. 

Hydm^^n 
Cirlxni . . 

(\\ rhitn . , 

Siii|>linr 

Sididiur 

I Nilmpen 



2,<I0 
11.91 



IIL TaRBON i'oMI'c HINDS, 



I. 

NMineK. 

iiirlKinir nxide . 
.\Iur*ili i?:i.H , , 

Klhyl rik'ohol . . 
Prnpimc ... 
BuUintf . . , , 



H 

27.79 
15.91 
29.H2 
45.70 
43.73 
57.04 



in. 

t'nr1*on, 

n.9i 

11,91 
23.82 
23,82 

47.04 



15.88 
4JJ0 
0.00 

21.88 
8.00 

10.00 



IV. NlTROiiEN, AND NlTRO«EN OoMPOl7ND8* 



I. 



n. 

1*1.93 
2il.8l 
<i2/i7 
27.8r, 
43.74 
51.08 



Nflinf$i. 
Anitnmiiii 
Nitric rtxirle 
Njinc iiciil 
Njtroiffn . 
Nitmup* oxirh 

TIjt* »iiij|de r<*hitit)n tu wliidi reference lian Iti^en mnde, ii 



HI. 
Nitro^tMi. 

13.93 
13.93 
13,93 
27.8»j 
27 80 
27.86 



TV, 
onief i*'it»mcniji. 



3.<¥l 
15.88 
48.64 

15.88 
23.82 




ATOMIC WhlGllTS. 



57 



when the nu miners whitli tklt iiit^^ Coin run Hi. in ijuh 
tttl»li' tire viHimlvn^l, Thus I hi* qiumtity ufearlj j^ubstitiiir wliirh 
in tbt* ?*Uite iil'|i;i*a (»L'lU|>il^H ihe smnv Sitlunu^ iirnli^r Ihe .siiiie r<»ti- 
ditMitiM of [jpfj^urf jiikI i^i ttMii[>tTMtiire, us 2 •rniiiiim^s of hyiiro)^t'ii 
(0>lu!im n.J, cl(K*.s uoi in jiijy nusf i'oiitniii ii sinaMrr ((unutity of 
hydro^ft'ii than 1 ^^rmnnu^ ofoxygvii ihiui 15.K8 giaDaHU's, of nir- 
b(*ri ihuii 11.91 jrriiiiiini'^, or af nitrogen thun MiA^»i gmniinej?. 
Further, if thu i|HunUty of any L<iin|Miuini nott'il in Column 11. 
csoutiiiiiii more thun 1 gniuiint! nf hyilrugt-n, it dotn nut tMnttun 
It*:* thitu 2 gr*irnnie8; if more thim 'I ^tiiinniw, not h-ss than 3 
gmtiHueH, and H*^ on. S^iiiiilarly in the nLse of iixygrn eoaijioundH, 
if the ((uaiUity nuted ii* t'olniiin 11. eoiitaijiiH more than IT). 88 
gruiiimeis of oxygen, it dnei* not ecitJtain h^ss tban Z\.76 grajiiuici*; 
if more than Hl.ItJ grammerij then not k'm than 47. ♦»4 grammes^ 
and W3 on. Kegiilarity of" the nutue mn\>\v kjn<l is iiIhj ohinerved 
with re>i|ieet to the eiirhon and nitrogen eoin|)r*undM. The lij^tM tjf 
c?i>miM>yndH given here are intended to he illustrative (»nly, nnd 
tiot eJchauKtive ; si nee eaeh talde might hiive been greatly 
eiteiided, and atlditional tuhle.s might have Wen given, emhraeing 
cfjni|)onnds (»f many other elejnents, when the siiine kind of regti- 
larily would have i*j»jH'ared throughout. !n the ensi* uf eni b 
element, therefi^re, there upjajirr^ in (.\tliijnn 111. a nuniinum 
nurjilx'r, and all the numbers in tbis eohiain tiir t>ne and ihe s^ime 
element are eitber thin minimum niiniher or rnulti]>les id' it. It 
i* roneluiled fr*ini the unifitrmity ob,<iTved in this resjieet tbat the 
niininjuin numlier w> obtiiined for eaeh element rejireM^nli* (rehi- 
lively to hydrogen assnriied = 1} the sujallest projxirtion by 
weight in whieh that partieuhir element enters into eoTidaualion — 
that thi» minimum number is, in t^liort, the atomic weigbt id' the 
element, Tfw atomic fhrorr/ offrrn n Kuffiiienf rjpifiiuttmn of fhr 
i^hnrrt^rd /rtftM, In the oxygen e^inipoundt*. for exanijile, the 
nioloeular weights of tlu^e eomjumnds utv inadi* U|i of the weights 
of the Jitoms of the t*tber elena^nt.i prt^ent in the mttlerule besides 
nxyKt'Ot »"*! **f ^t 2, 8, ete. times the weight of one atom of 
oxygt'n. From this* we e(mehide that tbe various nn^eeules eon- 
tain 1, 2, 8, etc. utoms of oxygen. It is elear tbat if a nioleeide 
cuututnH any oxygen iit all, it must eontidn not ii*ss titan one atmii 
of this element ; if it eontains nvore than one atou^ it eannol <'on- 
tain fewer tfuin two ittoia,'^» and so nn. Exiietly similar ennsider- 
HtioiiB may be apptied to ibe eom|iounds of other elements. 

An examination of the lUets contained in the tabh^s, and of the 

ooneluMions drawn fnaa them, jut^tities the view that there are in 

ejifh moltH'ule — 

Ofwnlcr . 

" eArbonir oxide 

" nilnaiB . 

" iini mania 

^ nmi-Mh f^H , . 
i tio on. 



. I atom ofuxyfsen «nd 2 of hvdmgen 

1 *' " 1 ** nirlH>n 

. 1 " " 2 " nitrogi^n 

. 1 ** nilrt^gpn 3 '* hvdrog^^n 
. I " earlKtn 4 ** ' *' 



58 aK\ERAL PRfNCIPLES OF VUKMiVAL PHILOSOPHY, 









A loin If* Wei^lit 1 

Stwritjr Ileal 
( At'iiuic IkMitJ 


mip Weight 


H|K?< 


trie Ih'nt 








22.88 




M 


m 


55.ri 




.112 





*;4.y 




.09a 


e.0 


118J 




.054 


6.4 


19K.O 




.0:12 


6,4 



Jn ihv tiihlcf^ referring Ut the conj|H>un<l8 uf livilro«irij, (»xyj^i*n, 
ami iiitroj^'fu, ihe eltTmut^ tUeuiH'lvr> imvr ali«> Uveii uiLhuhMl, 
It win hv ntitlvvtl that tin* lij^airi'^ iVii- ilirui in t*t>liiiiHi IIL »**" ihr 
rfHficrtiVf iiibli'H itrv not tln" iiHiiitiitiiii nuinlM'r> wliirli luivr betni 
iirrivLnl at as tiiij'ir 11 torn ii: wrijirhts, luU an* doublr tlii'^' riHuiiH'rs. 
From tbiH it in ciUH'ludi'd ilmt thrir iii(»lrfnli^H ihilsI carli tonwist 
ot' two, ami ol' not aiorr tluHi two, atfuns. 

Imw of ihdimij (luti Prtif, — Tbi?* liivv statA^-* tluil the iirodutt of 
i\w at<*inJc wnigljt iiml tbr H[>ecitic heat ol" solid rlenjvnti* i« a ooii- 
Hlirnt 1111 III Imt. This einistant is ealh-tl the ufomic A«vi/, and benee 
tht' liiw may also br staletl thus : — 

Thti atoaiie heat6 of all huHiJ rlenients are equuh 

The law ilof!^ not hohl ijuitt- aeeiiraiely, the aloinie Inputs of 
wilid elements hein^ lountl to differ fmin onr jinolhiT to S4»me 
extent. They neiirly all a(>|*rnxijnate inoilerately tlosi^ly, how- 
ever, to the nunihiT tJ.4. A fivv i'xanj[>h?* are given below: — 

SMrmm ... 

Irnii 

Ziiie , . . . 

Tin 

Mi^vury , , . , 

Tbe cletennination of Ibe s[>«^eifje heat is wnnetiiiieH matk* in 
onler to (oiillrin the jituiiiie wi'i^dit of an eleiiu'iit, sinei* tlie con- 
stant (1,4 -^ sperilie heat f^houhi ^ive a *|Uoti(Mit iipjiroxinuiling to 
till* atoll) ie weight. 

fhrmirn/ yofatiof*, — A ttynteni of notation lias \hh'1\ adopti'd ft»r 
the (Hirpise of shortly and eoncisely expreswinir the rhief faets 
lonreriun^ fhi^nieal aetions. TiiiM sy*<teni i?^ l>uw*<l nijon the 
faets, jtnd the thmrk-s dcdneed from thest* faetw, wliieh have \h*vu 
outlineil ill the jin-eedin^ |M*res. The essential leuture.s of the 
system are ex|>hniie(l in the tViilowin^r |>ariii!ra|dis : 

I. A'f/mWj<.— For the [>ijqtos«^.s of the Hysteni^ inieh eUiitent hm 
had a HvinlHil assigned to it. This symbol is usually the first 
If tier, w#nve times the first iind a Mjeeet^din^ letter^ of the English 
or of the Latin luimv for the eleinmt. Thus, Jl is the s^ymfHil 
for bydroy'en, Fe (Ferrum) fhr syndiol for in*n, and so on. A 
lint of the niinjeH of ibf idtrnentM. willi their symlwib and their 
atomie weigh Im will he found at top of piige •'V9. 

For a ntffipfrfr ]\A of the element*, with their ftytnhols and 
at4)niir weight/*, ^rr the Appendix. 

The symbol for ea<'h I'lement 18 employed t<) n»pre«wnt : — 

«. The name of the eh-meiit. 

A, An nhim of the rienieiit. 

e, A definite weighty in priumne?s uf the element. This weight 
Ir the nutnlier repret^^uting the atomic weight of the 



CHEMICAL NOTATION. 



59 



The Chief Elements mentioiied in the United States Pharmacoprpia, 
with their Symbols and Atomic Weights. 



Element. 



Ahiniiniuin . . . . i 
Antimony (Stibium) 

Arsenic 

Barium 

Bismuth 

Boron 

Bromine 

C-alcium 

Carbon 

C'Crium 

Chlorine . . . ^ . 
Clin>mium .... 
Copner ( (^ipruni ) . 
Gola (Aunim) . . 
Hydrogen .... 

Iodine 

Iron (Femim) . . 



I Sym-' Atomic 
bol. I Weight. 



26.9 

119.3 

74.4 

136.4 

206.9 

10.9 

79.3 

39.8 

11.91 

139.2 

35.18 

51.7 

63.1 

195.7 

1.00 
125.90 
55.5 



Al 

Sb 

As 

Ba 

Bi 

B 

Br 

Ca 

C 

Ce ' 

CI I 

Cu I 
Au I 
H 
I 
Fe 



Element. 



Lead (Plumbum) . 

Lithium 

Magnesium. . . . 
Manganese .... 
Mercury ( Hydrargy- 
rum) 

Nitrogen 

Oxygen 

Phospliorus • • I 
Platinum . . . . f 
Potassium ( Kalium ) j 
Silver (Argentum) | 
Sodium (Natrium) i 
Sulphur .... 
Tin (Stannum) . 
2jinc 



Sym- 


Atomic 


bol. 


Weight. 


Pb 


205.35 


Li 


6.98 


Mg 


24.18 


Mn 


54.6 


Hg 


198.5 


N 


13.93 


() 


15.88 


P 


30.77 


Pt 


193.3 


K 


38.86 


Ag 


107.12 


Na 


22.88 


S 


31.83 


Sn 


118.1 


Zn 


64.9 



element, taken as grammes; thus the symbol for hydrogen 
represents 1 gramme of hydrogen, because the atomic 
weight of hydrogen is 1; the symbol for iron, 55.5 gram- 
mes of iron, because th.e atomic weight of \nm is 55.5 ; 
and so on. 

2. Fbrmulce. — Symbols are employed in writing formulce. A 
chemical fonnula usually con.si8t8 of two or more symbols written 
side by side, as CO, which represents carbonic oxide. 

When two or more atoms of the siime kind are to be represented 
in a fonnula, this is d<me by writing a small figure to the right 
of and on a somewhat lower level than, the symbol. The figure 
indicates the number of atoms to be represented. Thus, the 
formula CH. represents a compound containing one atom of carbon 
and four ol hydrogen. A small figure similarly placed after a 
portion of a formula which is enclosed within brackets, multiplies 
everything that is so encloscnl. Thus, Ba(N()3)j indicates a sub- 
stance in which an atom of barium is combined with twice the 
group NO J. 

A figure placed in front of a formula refers to the whole 
formula, and shows how many times the quantity represented by 
the formula is to be taken. Thus, '^CU^ stands for three times 
the <|uantity of marsh gas represented by (-H.. 

The fonnula for a substance reprt»scnts in all ciises: — 

rt. The kinds of atoms of whi<'h the substance consists. 

b. The ratio of the nunilKT of at«mis of each kind. 




CHEMICAL NOTATION, 

c. A definite weight, in grainnie?^, oi' tbf mibKtiujce. This 
wei|rlit i?^ the siiiu o( the iitimiie weights of the ult>ms rep- 
rt'sentiil by the (uriiiiilL*, tukeii as ^ruiiime?*. It is Ljilled 

the fonnuhi trt'if/hf^ 
In the ease of gUiH^s, and of mllA^ and li([uiilH whieli eun be 
converted into the gaseous state without decompoflition, the 
fornniia further represents! — 

d. The quantity of the subst^inee whieb has alreiidy been 

referred U* iiiy the gramme oiolecule (p. f}^r). 
€, A detinite i'Mumr of the subsUuu'e m the ^^usimiu.s sl^te. 
Tldf« vrthiine is, in the ease of eneh HubHtiuieej wlien under 
the Hjune eonflili<»iiH of jire>!sure and of teiiifHrattire. the 
same tw that iieenpiet] liy two jti^rajnme^^ (ttie grannne uwle- 
cule) of tiy<lrf»^eii. It is ealted the gmnimr tmtitTftk 
voffjmr. When iiunierieai expresHirtti is ^iven to it, the 
eonditionn must Ih^ ntided, sinee it vitriej* with variatifiiH 
of pressure and <d* t4'nj[>ernturi\ Under standard eojj- 
ditions of pressure and of temperature (i.f., 7(iO Mm. and 
()*' v., nrr {i, 47), it auvasuren 22.2 litn^. 
3. Drfimi'mn uf fhv Fontinin for ft ihmpamid from ih VumpO" 
ttitiofi petrenf. — The results of i|uantitarive ehemicjd analyse** of 
er*iii[Mmnils are usually expressi'd m jairts by weight pereent* of 
wieii eoiistitueiit, Froai tliese rr?iults an etttpirieit/ /ormuUt vim 
Iw^ fledueetf An empirieal forainla no-rely expresses the rati*M>f 
the fuunber of atoais of earb kind in thesnndlest whole nundH^rs. 
A mohTufar fnrmtiffi^ on the olher band, ex]»resses t!ie nnndH-r 
of atoms (d' eaeb kinfl wbieh a jnoh^eate is assunu'd to eontnin. 

Tlie rule for the deduetion of the simjib^Ht fornuila, is to divide 
the quantity pereent, id' eaeh eleiiH.^nt Ijy the atoniie weight of 
tbiit element. The quotients stiimJ t<i eju h other in the ratio of 
the niHubers of atoms pres4?iit in the eompound. Thus, the gaa 
ethylene has the following eomposition jiercent, :^ — 

C, ^^\V^)l; H, 14.88. 

Dividing by the respective iitonue weights, we get: — 

85.62 ^ ILIU = 7.10, and 14,38-!- 1 = HM. 

Hut 7.10 : 14. 3J^ r: 1:2: henci* the earbon and hydroj^ren atoms 
are prenent in the ratio of 1 : 2, and ihe entpirieal fonnulu is 

en. 

The uioieeubir weight of tthylene, however, ih hiiind by 
ex|M^riment tola' 27.S:2, while tlie fornndii OH, eorresjionds to 
the UKilecubtr weight l.'^.Ol; henru the moleeuhir tVinrudii must 
be (CH,),, that i«. C,H^. 

N,B, — /'V*>w* thfi rtimfmxifion pffvtnf. fihmf^ thf rmpiriru/ /tirmu/a 
eatt be dtdueed. The uto/rru/at* formula can only br Mnined ivkfn 
the moUeular weight yi aim knau^n. 




GENERAL PmNCIPLES OF CHEMICAL PHILOSOPHY, Gl 

4, Cahuiafion of the (hmpmit ion percent, qf a tSubjifniire frain Uj^ 
Formufa, — Pirst add u|« l\w fonjiula Wfi|;ht of {hv subHliiiicc. 
Ynnn thiw mid tlie Ki-jmrute weiglttn nf \\\t\ rtmsiitiu'iits llit.^ tMira- 
poziitidti (lertvut. is obtiiiiml by tfiiii[*le |jn»|M>rtif*n. Thus, U> find 
the cuaipO!*itJuti peiYvJil, uf t'tirhonic anhydride^ CO^: — 

Oj= 3l.7f> (15.88 X 2) 

43.67 = FormulH weight. 
I 48.67 parts by weight t'uiitain MAW of carbon. 
U.iM ' luo 

.\ 100 ccmtwiti - ,., ., =27.27, 
4oJj7 

[I, 43.tj7 purls by weight contain '^1.76 of oxygen. 

:^1.7i> X H>0 

.-. lOiKoiitain - -^ -^ ^72.73. 
4i1.*>7 

The compottititm percent. thereifjrCj iw ; — 
C= 27.27; O =72.73. 

5. Ef/uatiofis. — Fonuula? are eiiipkjyed in writing chemical 
etjUtitiouH, These cqwationK rejtrcMnt the ilmni^t\*s which occur 
during cheniiuiil itrtions^. F<^trniula' representing the qnanlity iif 
eiich ^-iubstjincc which enters inb* actinn are placed on lUie side, 
and formuhc repre?M.-ntin^r tbe^iiantily of each product are jdaeed 
on the other side of the siirn (*f e<jUjdity (— ). I?*^twerii the 
various fornuibe on each Hide, sigim fd' addition ( \ ) are idarrd. 
Thene signs itrc not usimI in the sjioie sens*^ as in a inatbeniatical 
e€]Untion; arrd a ehcmieal ct|Uation is really only an eijnation in 
w* far tliat all the ntaterials retJreH**nted on the one tiide must \w 
accotintt^d ffjr in some tbnii on tlie other ?<id€. 

The eheniiea! change whirk r*erurs when zinc is jdaeed in 
dilute sulphuric aeid is represented by Ihe ei|tnition: — 

Zn ^ n.lS(>^ = H. i ZnSOj 

Th inequation, besides showing the nature of the rcHrrangenienlof 
utf)m!^ which taken place, indicates the jiroj^irtions by weight in 
which the sulmtanccs interact and Ihe iirtiprjrtionsof the f^rodacts, 
iitice each symbol iind formula has it"^ own tp^iintitjitivi- t^igiiili- 
'^tCation. ft further incJicati^ the volume of hydrogen which can be 
obtained from the weights of nniterials rejiresf^nleil, Minee iheforni- 
tila ftif a gas re[>re**ents not only a delTnite weight, hutais<^*adelinil« 
volume (at a given pre^sun* and temiierature) (}f the gas. Thus, *>4, 
irrHrnme^ of zinc and Ii7.*i5 graaiines of sulphuric acid yield 2 
yrramme« *>( hydrogen ami ItJO. 25 grammes of zinc snl|ibjite. The 
2 gramuR* of hydrogen (K'cupy 22, 2 litres at CC* and "fJtl Mm. 
From sucli tMjuations, calcuhiti<»ns are readily made of the 
quuntities id' suhstitnces by weight or by volume obtainable from 
given quantities of matr' rials. 





62 GENERAL PRINCIPLES OE CHEMICAL PHILOSOPHY. 

TiuHtead f>r writiu*^ foriiml tHjiiations ti» ri'pn'SL'iil fbrJiiical 
actions, tlie stiKlnit will uftt^ii fiinl it lK'l|itiil jukI iiistrui'tive to 
draw tiiiigniiiis itf u kind whirh A\*m eiiiiully well tlii^ uripiiul 
form in whii li thf vamms I'K'iiieiitH urt' brou^^hl iiit*) reactirm, and 
the de^tiriiition of llie ditlerenl atoms. For exuia]df, in.'^k^ad of 
writin^r tlu* equation givi-Ji alxive, tbt' lil K-ration of liydro|::i'n by 
the iiitorai'tion of /Jnt; jirifi dilut-t^ .sulplmric arkl van hv Huttiiiently 
represenUMJ for moHt [>ijri>osi's by writing the formuhv for Kim' and 
snlphiirir ;icid either in the mww line or ont* alHivc the »pther, t<i 
fibow what Kntistaneo inkTatl, tmd then drawing a Ynw. to <'aebLs4' 
the 80^ of the Kulpburic arid formula along with the Zii, and 
leaving the H^ nf the Hulphurie acid formula uutsifk^, xhu&i — 






If tht? int^raftiotj u\ zinc with liydnK-hlorie acid is to be repre- 
isentt'd, the diitgraia can be eoiiMlrncted tbu.**: — 



h;oi n 

The construction of such diiigrams ij* particularly uneful in aiding 

the Htudciit to obtain an insi^dit into nuineroiiH rmn|>licatcd int«^r- 

at'tions. Other examples will be ijivrn further on. 

[ E*jttirtf/iNfM ( I Vf/r^rv).— Those rqu lint itit^ ofWUfftTctit elemcriU 

I b whii'h ar#' capnhle of jdayinj^ the 3^no part ifft-bprnieal eombina- 

LvV' i li<>H, are said to bo ffpilvafmt t<i each other. F^vr comparis<jn of 

I y / the equivalent weiifhtH. of fli tie rent eltMnrnts, it in ermveiiient to 

^* ' adopt a standard, and the standani chosen is { pari by weight of 

hydr*>geri. 'Iln* e<juivjd<'Hl wei;:btK^^ — or ?*bortly, the aptivafrnh — 

U of other rlt^menlH ure eajmlHe of tukiitg Ifie [daet> in romV>ination 

^ of I part by weight of bydrog^rn (.oid fn/quontly, moriHJver, of 

combining with the s:une weights of other tdeaient'* tfial I jmrt by 

weight of hydrogen eoml>ine-< with >. Thus, in ]Mitassiunj i bloride, 

\\V\, ;^S,Ki> part.s by w«iglil of [»ota**niuni lakr the place of the 1 

(lart by weight of liydrogen eontainetl in hy<lrocbb»rie acid, HCl, 

hence the equivalent of pot4U4«ium is ;?8.8*k In ealeitim sulphate*, 

Ca»StL, MIKM j»3ii1h hy weight of I'aleiuin takr the plaee of the 2 

parts ny weight of hydrogen eoutainod in iiulphuric acid, H„S(*^» 

hence the etjuivalcnt of caiciunj is =19.9. In ln«niuth 

riitrute, Bi(NOg),, 200. «♦ part^ by weight of bismuth take tlie 

place iii S partH by weight of hydrogen in thrtn* moU*eule*i of nilrie 

20(1.9 
arid, JiHKOj. hener the* ^Hpiivalent in „ = GM,*HJG, and si> on. 




EQUIVALENTS. 



63 



The number exprps^iiij^ tlie eijuivulciit weight i^ thus sr)mt?trriit'« 
the HfiniL' siH the iil*>iiiif weight, siimetiitie?* it is oiie-hulf the utamic 
weight, »t>juetiiiieH one-third, iind so on. In nlher words, an liUim 
of auiither element i\my be nqnihle of tsiking the pliiee of {or 
nfeoinbiniiig with): — {n)im^ atom of hy<irMgen (iin atfuii of |Mitiu^- 
feiuin, fc»r example); \b) two MloniH of hydrogen (jiii iiloni of caleintn, 
for exanij^h'); (r) three jitonit* of liycJrogeii (an atom of hisaiuth, for 
•exit»i{de); and sim»il The power posseKHed by the iitoiiii* uf other 
eleaients, of replaeing or of eomldnlng with diftereiit nnmher^ of 
hydrogen aUmiH, has hiH'U ealh'^l the ftfominh/^ or efutibrnhifj enjfitr- 
ittj or qunntivakttn\ or, perhajts more eommonly, the rahnnj of 
the clement**. 

The number reprewiiting tlie valeney of un tdement may be 
am.'ertained l>y observing thr number of Iwdrogeii atonuM whieh it 
\A ertpalde of refdaeing, or with vvhieh it \^ eapable of Cfimbining; 
aliifi, by observing, for examjde, the runaber of atonu* *pf ehl<»rine . 
with whieh it i?* ejquihle of eouddniiig — eaieli atom of ehJorine 
i being regarded aw r>f the name vuk'uey aw hydrogen, becaun* em-h 
atom of ehloriiie eombine?^ with one atom of hydrogen. 

For eXanijde, potaswiiim (K), ealeium (t'a), bitsaiuth (Bi), and 
airbon (C), aixj regarded as univufmi, himknt^ invaimf. and fptad* 
rirn/efif, re^pec-tively, beeaa.se tliey tlirm ehhirine eoni|»ouud*4 
re|>rewented by the t<»rmuhe KCl, CaCU BiClj,, CCI^. In tht^ 
cjii*e of earbon, i'H^ is al^i Icmiwn. 

With rej^peet to the termn fifuhmfcui and rtUenrtf^ it is hi be 
noteil that Ibey are applieable to rndieals^itM well as U\ ut^mis. 
Thuf«, in enlejum sulphate, f'aSO^, the rmiieal SO^ is t^piivalent 
t*» (N()j|)j in ealeiuiii nitrate, t'a(Nf),)3, or to V\^ in ndeiuin 
chloride, ("af'l,, t«inee it in eH[iable of ermjlnning with the same 
thing, i.r,, witii one atom of laleium. SO, is a bivalent radieal, 
while Wh NOj and (1 are univalent. 

It if* HimietinieH eonvenient to iiidieat^* the valeney of a metallic 
radieji! by plaeing after it an appropriate numlxT of dots, thus: 
Mg": and nimihirly the valeney of an arid radieal may be indi- 
culed by an appropriah' numln'r of dashes, ihus: Pi J/". 

BiurM^ Anih^ tiHtl S*tifK — In ♦irdrr to give the student mmxe 
familiarity with the**e ebisse*i of ehenjieal snl>stanee.s, and so to 
prepare him (be la'tter to understand the us<* of the words hnnr^ 
arid, •ali^ and the fre<|Uent refereriee» t<» these substanees in the 
imniedtalety sneeeeding portionn of this Manual, it is desirable, 
I>e|J*re eoneluding the diseussion of the general prineiplt*s of 
themiHtry, Xa make f*ome genera! i*tatement*i reganling these im- 
piiftaat gmupr^. 

BaseM. — ^There are twt> [irineipal ela.ss4>s of eomiMmnds whieh 

' rhe nauw mfli<ttt h very ofteii used in eheiiti.Htry t** dir^iguatt* a wroap 
rif iit4inix whk'li h f'omiiinn t«i a luniibi^r of couip-tiunds, and is tii|iithln of 
bring tmu*iforrviil fri>ui uae eoni^Hiuiid ta anuther wittiont itself hrcaking 



H4 GENERAL PRINCIPLES OF CHEMICAL PHILOSOPHY. 



belinvi' iLs Imwc'Hj and [»(>mjH'sh in a more ur less inarkrtl ilru^ree llie 
propertii's oi' these BiibHtaiieess, hh detst-TibeO furliier on. Tbes<? 
tw*> elii?*Hi-!^ euil>nn.'e : — 

I, Thu \nmv oxiilc-s itml byflroxidi-s o1' the luetals. Example.s— ^ 
(-'alriuni oxide {t|uieklime) Vtki); ealeiuni hyclruxide (slaked 
limt-) <ja((>H)j; aliimiQium hydroxide AI(UH)j; ferric 

oxide Fe^Oj, ete. - 

Annitoiiia, NIIj, nud thi^ Hiibstihiled animonia>! (such as 
lut'thybuainv, NU^iHj,; diioelhylainiiie, NH(CHjK, ; 
aiHliiif, NH./'^jHj^, t4c.);alfMi a large uiiihIht olallied huU- 
aUmrvT^, iiieludiiig the natural alkabiids (sueb a>* tnoqihine 
(\,Hj,Nn,, U.p; jslryebtiiue ^.H^N^O,, vie. 
There are groiiiiiis tor Kiipposing tbat all suhhtaneet* wbieh 
exbilnt the t liaraett-rs of ba^-H arc hydroxide'^, and that those 
r*»rinHiuiids belon^iii^ [n the abcne two elas^He?i which are not 
hydroxi<lf« t(» bt'giu with, must iuterart with water, *«» as to yield 
hydroxidt's 1h lon^ tlieir eajnu-ity to ladjave as ha^es iw tk'velopeil. 
Thus, il is probable that <juirklinie is not it.s<dt^ a base, but that 
the actual base l^ ?ilakcd Ijiue (ealeium hydroxide), which is 
Ibniied by the iuteraetioii of tjuieklime with water: — 

(^a() + H,0 = Ca(OH), ; 

ftnd that amiiioiiiji only attains ba>*ie pro[H*rties when it hiw inter- 
iieted with water to fonn ammoniaia hydroxide— 

NHj+ !f/>=NH/)H. 

Prop*rtirn of Bnxes, — Those }>a>*«*f< w hieb cUksoI ve eiwil y in water 
yield s*>hition« posseKsing an fslhnlhtt' rmetion^ thai is, their solu- 
tions exhibit the property possessed by solutions of the afkafim 
(pfitassiuni hyilroxide, KOH, and siMlium hydroxide, NaUJI, 
wlrifh an* th<'mselves basie hyilrf»xides, M't pages 72 and HfJ) of 
turning reii litnms pa(>er blue, of lirowning yellow turmeric 
pa[>er, eir. 8<diilions ut" soaie of the aaist easily soluble bases, 
such as potiissium and sodiuia hydroxiiJfs, i>osscss an unpleasiiiil 
tJiwte, reseadding tliat id' sci:i[»y water. (As a auitter of taet, the 
t«ste of i'oai>y water is chiefly due to the presence of rmc or other 
of these hydr<!xidcs in small <^uantity.) 

Bases intera4't with acids to form mffs. This statement is true 
gent-rallw but it rci|uires ijiisditicalion in scj far ihat therr are 
»ome baikt^s which (usually *m aeccmntol" their insohdde chHrueter) 
are in it {ictet! ujioi* by eertjiin acids, W^hen has** interact with 
ftci(is, the formation of salt^ is aceompame*i by the formation of 
water:— 

Ca{( »H), ] 2UCL = CaCl, + 2H,0 ; 
2AI(f)H), 4 m,m, ^ Al,(80,X f fiH,0 ; 
NH.UH f HCl = NlI.Cl + H,0; 



BASKS, ACIDS, SALTS. 



66 



5».— Three* im]M>rtant elxsso-s of iicidn may he di?«tinguishetl. 

These clsis.s«^s fii» not exhiint many iirrMiihifiit dilftTt nreM in t imr- 
acttT, Jilthuu^h ihiy differ Lousidi'rahly n\ tiunr gem-ml I'hfmitiil 
reliition.^. The three L'IaKse> are : — 

1. Acids* whit'h rimv In* reii^arded ii>* ik'riveil from uM oxides 
or Hcid aahydrities, hy the lutioij (»r uiiUt. Thus sijl- 
phyric tiJi|iAilritk' wbeti treaU-d witli wuk'ryiddii wulplmric 
acid : — 

8(), f 11,0 = ii^8(\ 

(The riuijority of the more im|Hirtant aeid iiiiliydnth*> art% 
ttfi the f^tudeixt will hnirn Inter, oxides uf riKn-metnllie 
elenieiiLs, ) All the aeids* iK-lorij^iiig t<j this cliiss contain 
oxy'^eiL 
Aeids whit'h ilo lud n>ntiiin any t^xy^en in their euinpo- 
KJtinii* The hest exampli'H are the hii1(»gen aeid^i — hydro- 
eblorir aei(i, H< "I : hydr**l>romie arid, 11 Br ; hydrkidic 
iiciil, Hr ; and hydroHuorie ai'id, II F* 
A lar^e numlHT <*f i*r^anie at ids, u\\ eojilaininj^ earhtiti, 
hydr<j<iren, and (►xy^en, eithiT alon^^ with, or withiuil cither 
elemeiiti** Exsim|des — Dxalie aeid, H.XV**I *>*'**tie aeid, 
HjOjO,: kfawJic acid, H^CyX; ehlorae.-tie aeid, H ,l\n.l1, 
ettv 

Pft/pf'rfii'jt uf A^'hh. — The niaj^irity ni aeids ilissf)lve readily in 
water. The mjuwjius solati<Mis ia most rsust^s possesn ttie fu-i*i 
ftnfiifiH^ that i.H, they ri'dilen Idiie litnnis jniper* They a!sf( 
|*«j«seM8 11 ehnrsieteristie Ruir tii^^te, jim in the laniiliar ea>«^*^ of 
tAftHrie iieid (the ueid of unripe gnipeH), Hcetie aeid (the aciti 
pr*\*M'nt in vinei^ar), et<'. 

All aeidn eontain hydnijron iiN an t*ssential ermstitnent This 
hydrogen is replaeiuible, in srnne eju-^es whidly, in some oidy 
[iHrti;illy, hy airUls, or hy ^rrnnps of jitoms (radieals) whieh play 
Uie part of Uietuls* The snbstanr<'s produeed hy surh replare- 
niriit are called milfR, They are tVirmed^ as has already Inrri 
utattMl. by llie interaction of hase.-s aad acids, with the t<iui»il- 
laueou!^ production *»f w^ater. 

Stilts, — Salts arc eomp^iuads which ai;iy all he re^^anlcil as 
niadi' tip of (Metal, or of a radical whiidi phiys the part of nntiil 
— i^mh metal or ni<Hcal fotniini^ the mrUtUlv at hiuir nuiietff — 
tinit4*fl to jm atoia, nr irrouf) of at^ans, which constitiitcM Che nrid 
r*H(u\d, Che ntet^dlie radical of the s^ilt takes the [dncc n{ the 
hydrogen of the aeid, or of a part of it ; the acid radical of the 
Halt i>4 etamnon ht»th lo the sjilt nnA to the aciil troni which it irt 
«ii?nvod. [n a M^nfte, the acids are themselves Halt,s. They 
elort«dy rc^nihle sidtj* hi several particulars, and they are frc- 
Huc*ntly called /iy<//w/r» mtftn, 

Halti^ are proiluci/d in VHrious other ways, as well as hy the 
itit4!raction of banei and acid^. A eoruuion instance of this is 




66 CfENERAL PRLWIPLES OF CHEMICAL PHILOSOPHY. 



Been in tlie fomiiilinii u{ sitlts hy the inleri»eti"in of [iit'tiil« and 
aeitlrt. Til us Uie bent way Ui prepare .silver nitrate m to tr«at 
silver with lutrie tie id. 

The tliUiivvin^ elassc^ of suits tire diiftingoiished : — 

Neutrni Stifh. — ^ These Kjdts when dis?<<>lved in wat^r yie!d 
solutions nhieh sln^w neither tin- aeitl nor the alkaline react km. 
ICxatnples fit i*eutral wilts — Sjditiin ehlnriile, NaCl; putaKsium 
milphate, K,^S()^; ete. 

Sonunl Ni//jf.^This name i» applied to naltw whieh are formed 
when the tfho/r of the refdacealHe hyclrojt^en <d' an M'id is replaced 
by a metal, Nornmt salts are frequently neutral als<», but they 
are not [u'ee*i»!irily so. Examples at' m^rniuJ milt<a — Poljissjum 
sulphate, KjSt)^ ; sodium larhoiiate, Na^CO,. 

Avid tSitih, — Suits whieh eontain s^ane of the rejilaeeahle hy- 
drogen of the original ueid iiiireplaeeti ljy iiictid, are eJilU<l ueid 
salts. They are iiitermediate in eomiiositi(jn hetweeii the :ieid 
aud the mirmal sjilt Thus pntusMitun hydroj^en sulphate, KllSt j^ 
(ati aeid sidt), is inlertnecUate hehveen sul]ihurie aeid, H^Stl^, 
ami normal potassium sulphatx', K.jS(j^. Arid s^dt.s iwuvHess the 
aciff rhtimt'trr^ in so far Ihal they >titl rtaitain hytlrogi^n of ihe 
ori^imii aeid, whieh is replaeealile hy aiet;d to ffirrn a norinid salt. 
They do not, however, neeet^sarily show the acid ri^aetion with littnu»» 

IltiMif Sfift^. — Salts whieh are interniediate iiU"oni|*ositiun between 
baaie oxide or hydroxide and normal «iTt, are ealhnl hasie sidt*. 
Thu« bismuth oxyehlorid*^, Hi* Hi (a basic salt), is intermediate 
hetwerii hasie bisnintb oxide, ni.,0^, and normal bismuth ehlonde, 
Ritlj. rksh' salts [Mwsess the l»asie eharaeter, in so far that 
they still eontain oxypren of the basie oxiile, or hyilroxyl (OH) of 
the hasie hydroxide, whieh is replaceable by an aeid radical to 
form a normal sidt, A large iiuiid»er of basie salts an* insoluble 
in water, a ad eanuf^t therefore show any reaction with litnuis. 

Htmrihf qf Anih^ ttnd Aridity of /^fi/f^^. — Acids are called 
n>«inolw»sic, dibasi**, triba^^ie, etc. ^ aeei>rding as they ecmtain in 
their nadeeules one, two, three, etc., hydrogen atoms displai^i^able 
by metals. Polybasic acids eontain several displaceable hydrogen 
atoms. Hji-Hes are called mono-aeiil, di-acid, tri-acid^ etc,^ aceortl- 
ing as tUe aeid radical from one, two, three, etc, mfdcculi^ af a 
monohasie aeid enters into the composition of the normal salts 
den veil fmuj tbi'ur. 



Equations illustrating l>a«idty of acids : — 

UNO, i KOH =KNO, f H,/) 
IIjSO^ f 2KtlH - K,HC)^ ^ iHgO 
H,PO, 4 aKOH = K JH), H- :m,0 

Equations illnstnttin^ aeiillty »d' bases : — 

KOH ^ nv\ = KOI ^ ir,o 

Oa(OHi, f 2m "I = CttCl, 4 2H,0 
Bi(OH)a + 8HC1 = BiCI, h •^H,0 



I 



ELECTROLYSIS. 



67 



Eiretroij/m. — When a current of electricity is |m8Kixl tbrou^h 
a <!ilute dilution of Hul|iliurii; aeid, by iritnMkuiri^ into Ihe 
solution eitrh^xirjt {whkh nwiy ionwiwi fonveiut'nlly of strijis of 
plutinuin foil) eoiini'rtei! with the wire?* leiuiing from a sutfteiciilly 
jHiwerful batU'r)\ hv^lm^en in guen otf at the eleelrocle coamTled 
with iUi* negative pole of the battery, an<l oxygen at that roii- 
nretisl with the positive fvtih'. These g{ii*t^ are j^ivea nW m the 
l»n)\H}ri\otm in whieh they ermibine tt» lorni water, and the exper- 
iment at first si^ht api>ear;^ Ua ]k\ and i^ waiietijiiei^ t*Jniply called, 
tho tUctrolyifin (that is*, the decoiuptjsiiion by a current of t4ec- 
tridty) of water. The sulphuric acid, however, altliongb ita 
quantity remains the Haaie at the end of the exjaTiinent an it was 
at the beg-inning, obviously phiyH an jniport4uit part in the[»roce«*, 
betaui»e in its alxj^eiice seareely any current ihikscs, :tnd ei>rr»/H* 
pondinj^ly little wat<'r i.s deeoinpowed. The nature of the eheai- 
icmJ change which tiikes jilare amy be re|>res<*nted as, in the first 
place, the h'beration, from the acid, of hydrogen at tlie one 
idectrode and of the acid radical —the group tSO^ — at the other. 
But the aeiil rjidicii! (SO^l in unknown as a separate substarn-e, 
and is probably incapable of exiHlence as nuch; hence, at the 
moment of it*, liberatirm, it intemcti^ with uakr of the sohition, 
taking it« hydr*»gen to form s^nlphtiric acid again, and liberating 
iU oxygen. These changt^a may be illustratc^l <ltagramnmtically 
a» folio w» :— 

(«) A« the fir»t result of electroljaiM, H^SO^ yields : — 
At the ii«g»UT« electrtxlc. At the positive electrofte. 

HH» [SO J 

(b) Further change : 
[SO|] and HjO- give H^SO^ iind 0» 

Accordingly, the final re*<nlt of the change is that water rnole- 
cule^ are, by thin indirect ineanH, decompo!*ed into hydrogen 
and oxygen^ while the Kul(4iuric acid remaiDS in undiminishM 
quantity at the end of the experiment. 

A cane nearly «nu logout with t!ie preceding one is that of the 
dcM'trolys«iift of a j^dntion of fcM>diuiii Kulphate. In this caKe alw», 
hydrogen and oxygen are given off in the |iroportic^ns in whieh 

* 8hi-' '.f hydrugf^ti and of oiygpu lilftratetl in tliis wsiy ut the 
fcgfjmi'{\ ^tes iiidto with caeli other in iMiin* t** fnriiii innlei-tjles 
<jf iniN ■ . .^ .- i;;e!i, lit, aud oxyKeu, ih 0»r ilit^ uxygeii atoais may to 
wmn** exl4>nt anite in grnuii» of three to tutm mul<M!ul«a 4>f o£Oii<s 0%\ 
[tf^ Index b 

* The group [POi] mHTiil84i t»c r^garrltd as int^'rartin^ with two w«ter 
atoli^uh'n 141 form HiSVi* tiii<1 two [Oil] >jroups» whieh latter nr© then 
nappoM^d to iiitenu't, with th«^ formiitinn f»f watrr ami oxygen: 



poj I 



linu 
won 



np^), I 



[;;!!]-•-' [oil] ^ "■" 



f 1) 



^ 



m atCXKHAL rniNCIPLFS OP^ CHEMICAL PHllJhsopHW 



tlvy sue i»ri't*i'iil in wjiUt. It iiuty lie rejirvHt^ntt'd thiit tXw. sudiuiii 
?'uljilijtU' \^ iinnt Ki'pnfMtrrl into 8<*dium aad the add radit'iil iil" the 
!<iiliihitlcs, Na^SO^ yiehlhig : 



Al the negative «let'trodt*. i 

Nil Nn I 

\\m{ ill this illliljlllCr tllf SmlilMM !U< \M' 

inlo 11 luw rosu'liuu witli wiit^^T ul tht* 
furth«/r rhiiHt;<"H iM't^ur : 



2Nji and '1\\J>) pve 
2Na()ll aiitl H,. 



[SOJ 

II a.s iht* tiuid radical enters* 
siilution jirid thu lollowin;r 

[St*, J and IM>give 
HySO, and O. 

Ill li^lit <if tho fViregaiii^^ mode ul" re|>rest*nting the electro lysis 
id' sodiuHi sTd|»hate, it would ui»iiear that s<»dinin hydroxide is 
|»roiiai'ed at thi^ ne|^ative ptde in addition to t\w hydrogen; and 
that sid|diurie aeid is produivd at tin* i>o.sitive |ade in udditioii to 
the oxy)^en* Thin in indeed tdnnd to he the ea-s<-^ and may easily 
lKMlrinoastr;it4Mj by tt^ti ng the lii|uid in the innnediate neighhor- 
h'MHl of thi* two eleelroden, by nie^uirt of lilnias jiupers, during 
the ii!issa/e of the eurrent. Whdst the widiuin sidjdnite ^olntion 
i.s itf*elf tiruft'fi/^ the H*|tiitl at the negtitive |ioIe is fiamd to Ik* 
aihtiffn\, and tlisit al the (>fHitive jnile Jh found to be aeid. It in 
to be ooUmI, moreover, that the fiuantity of .sodinni hydroxide 
Ibnned at the urgattve electrode i^ exaetly the quatitity re<juired tn 
internet with the wboh- ef the sid[»hurie aeid formed at the [johj- 
live elect rode ♦ to f<»rm jMidiuiii sulphate sigain (neutral solution) 
in iict;<jrdanee with the equation, 

2NaOH + H,80^ = Ni^SO, + 2H,0 

!io tliat when the wilutifm is thorou^ldy mixni tip jtndium sul* 
phate \A preisent in it in undiminished qniinlily. 

Other sdtx in aqueunH M<>luti«tn <or in the funetJ state if they 
stand fusion without inidergoirtg dei'om|H>sition) ean alH4> ik* ele<** 
tndyzed- The metal of the sjill, or that whirh pluyi* tlo' jairt of 
metal, im seiuirateil at the negative eleetn#<le, afid the aeid rarlieaJ 
at tlie poHitiveeliH'trode. StdManees whi<'b are capable id' deeom- 
pfwition by electrolysis are enHed eitctrnhjtrft. When the lirsl 
prtKliicts i}1i the elertrolysis art* eupable of cxiHtenee in the eon- 
ditioUH under which they are |)r*j<hieed, tlieu thei^io an- the 
products olnainc^h Secondary changes* are, however, of fnH|dent 
oeeurnijco, ns in the ibregoing ilbist rations* 

tn regard to their electroly*^is, the acids (hydrogen wilts) twhnve 
in a aianner exactly analogous with the beha\d«r of other siilts. 

The |M>sitive clectrfHU' is otl^^i called tlu» tuiode^ and the negji- 
tive electftde the mfhofir (am, ona, ujtward; hnru^ hUn^ down* 
ward; oA>m:, hi^lnx^ way), Metals iiiirl liy<lrogen are «et fnn* at the 
cathiMle, and acid rudicuU and f>xygen at the ancKle. 

It hn^ }teen found that tho quantity of an electrolyte which 




ELECTROLYSIS. G9 

lUjdef goes tlfi"0iinio8iti Mil by electrDlysm i» directly |)ni|H>rtioimI tu 
ilu* jiuiount of furr('rit pass.'^iHl thn>Ui,di il. FiirtluT, it lisi> bmi 
fimri<l thai tlie ijUHiititivH (»f liydntyifjj, iiinl ihe <|UiiJitiUrs <jf 
oxygt'ii lilii^nileil in ;i irivt^n time from dilute solutitHLs of sy||»lmrii' 
ttt'id, of ?Mklinni 8iil|ilintt% and oi' piitiUHsium sul[>liate, vvlifii the 
t'urrt'nt is pstsst'it .Hiniultum'nuNly tJirough nil thivr .s(*!uti<uis, are 
tlif satrie for eucli solution. SinnLirly tLt- ijuiintiti*?^ of roppiT 
^piiratt»d from two or mon^ ditli/renl cupric i^iilt?^ under like roii- 
ditiouK iitv identkal: uml the sunie kind of rejuriihirily holds* good 
lor other luetid** and aeid rjidieid^s. 

In reeeut yeai^ elertrolytie methods hiive been exti^nnively 
iritrodueed for the lerhifind produeiioii of ihemieal eoin|jounds, 
for the se[>aratioii of metals, etc. Referi'iui^'s to the pre|»anition 
of a nuiiiher of ^uitsLinee.s hy these methods, are auide in varioua 
|.da('4^ in this Manual. See, for examjile, under pohLnsinm ehlor- 
jitf% wcMlium l>y hydroxide, ioflutorm, aluniiyiuni, sodium, ete, 

Ojiygen jiiid liydro|ren, when liln-ratid from eomhinaliun iu 
iiiiiuediate coalfiet with suh?.tanees with whiih they are capable 
of iuteraetin^ U* yiehi pnKluet.^ of ojtfifttifiH and rtfiuvthm (redue- 
tron — d(HjJtidtttion or reujoval of oxygen), are fonnd to be mueh 
more active t<iw;irds iht*se s^iiihstanees than they are if prepared in 
fiepainite ves^^els and subse<]uently Lirouglit into eontaet with them. 
The mpecuil aetivity of ^iieh mutrfnf iit\, newly fonne<l) oxygen 
*iid hydrogen, ha.n l>£^en attributed to the aetion of ttUtmx of Ihone 
elements, which enter into olh*T reactions without eondiining in 
pair>t to form oxygen and hyrlmgen tmtftruit'H. Various elertro- 
lyiic and other oxidations, redut-tions, et*',, an* a)»parently <lue hi 
the action of luweent oxygen, nascent hydrogen, nnst-ent ehlorine^ 
etr. In a nundier of cases in hiter parts of th«' Manual, where 
CijUalions are given in which the aetion of njiseent hydrogen, ete», 
i* rrprei»ent4:^d, the aiomie symlKils^ H, t), et4'., are U:^tl instead of 
the molecuhtr formulip, H^^ 0„ et*% 

Thr iiuiind in rrrommntfirti fo rrttd the fort'*jointj pftrfifjrnph^ on 
ihr (irttrvfil pnnrijdt'M of ('hiiiirtti i*hihm^^thtj rnrt'Jufhf onrr or 
fiHrr^ Ihm io Ahiiit/ [cjprrintrftftti/tj^ if poHnihit) fhfjhf/tiiriuf/ fnajrA^ 
rfitiminfj tft and rvmlintj ot^r the fintfrftl f*i'htHplrjt /mm time to 
tiffie, Hntif they are (fmnmtjhhj Htmjttehrtidf.d, 



QUESTIOXS AND EXKUtI8>:S, 

WUiit dfi ymi uiHlcrstatift l)y ♦•lu-niiejit elaingeti?— Give f^xninph^^ of 
choniif^il Aiul plrvsionl fliini^t*fi» — Mi'iitjon ^mw of rho chief pin nom<"iiji 
whirh iiirompioty tyiarnl nisrs nf rlimorsil rJiuii^f, Wliat i> tlir (lif- 
fcr»'fw*^ hi'twiHMi nil eleini'iit aiul a lonijwjijmi ?— Wlmt do yon andrrstHnd 
by thr t€^Tm " ebemieal iiflinity'*? Nftnie tlii^ (.liief Iaw« ♦if ♦lit'niiuil 
ronttiiiiutifiri. — Sditr the laiw <tf roii^tsmt pnijxiTlhMis- Stale the law of 
oiultlptf' prujNirtioas. — Stute tbi' luw of ^a»«i>u»« vithimi'S,— fHve an ont- 
lin*^ fk the utoiiii^ theory. ex]»hiitiinir \\)uv\ \f< mnlei^tuiNl by the terms 



70 THE ELEMENTS AND THEIR COMPOUNDS. 

"atLHu" and " m o lee ukv."— What is AvogaUro's hy|iothesis? — Exiilaiii 
why hydriiKfii molticulfa jin? u^Humed to eimsist of twr* lliydroK**ii utt^uis 
cudj.--VVImt ri'liition exists IwlvvtiMi tlu' n?lulivv diHi.siliesaiul (lif luole- 
tiuhiT vvfJubtH of pisc'ii?— Whiit i,H thu "jframuie tiiolucylo " ?— Explsun 
iiciw Avojipwlr*"*!* hyiHitheds may In* jjippJiiHl iu thu lixiug uf atofuii' 
weiKl»lji.-^Start4ji tliL' hiw of Duluiig luul l\'tit» and explnni how it may bt» 
uf service in Hxiiilk iitomic WfigliLs. — J'lHiujt'i'utr the fuiietioimof ii cliem- 
if4il symbol iiiul of a chfiuiail fotmiilti, — Writi^ t'ljiiatiuiis it'jire»eiitiiig 
tile foniiatioij of liydrogen hy %lw iiikviwlioti of zinc with hyilrochloric 
uciil imd wilU HtilidiuriL' acid. — Muntinu the- rtiamctcrs of luiKeRaud u«idEk, 
&iid dej84Vnbi!< the geyerul ositiirt.' of the iiiteruetioii iif hasen iitid JKrida in 
fuiuiiug aaltii.— What are neotml salts, iiurtiml salts, acid iialts, tiaiije 
salts?— til ve t'xampleft. — Uefiue fleet ro lysis, electrolyte, eU'etrotle.— 
What do you uudrii^tand hy **niisi'ent ^' hydrogen? — Name iH*me inipor- 
tjint stjhstanee^ whieh arts now prepared on the tuaQufai'tiinnj^ B<.*ale by 
elt^c truly tie lueLbixU. 



THE ELEMENTS AND THEIR COMPOUNDS, 

Having thus tihtaim*^! a p^ncnil itlfji uf thf lutture of nunie of 
the iioti'nK4a]Mc i^h^ineiiti* whicli have sfunial inlert>l for th*^ uk"*!- 
iral itnd phariiiiH'fUlirnl stiidoiit, Jind of the fuiidnrnentiil p>rinci- 
jiteti fd' fheuiirttry, we may fui^^s an to t-i insider in detiiil the rtdji- 
iUmA of the ekMiteiitn, I with iiori-metallii' atid itietidlic, ti earb 
otlier. The eleruentw tlieniHelven, iti the free c<inditkm, an^ sfl- 
dum ttj*ed in inedirine, bein^ nearly ulwavi* in rouddiiatitm — 
hrmiifj to^retlier by the foree uf rbeinieal affinity; in thi?* eondnned 
e<»Tiditi<m, therefore, ibey must be (Studied, (norgiinie e(nnbitiuti*m8 
first, <*r*£aiiie aflenvjird?<. Mci*<t enin|j4>undH met within the niinerai 
kitiifdoni nniy be reg'artled nt^ eontaining two (lart-s «ir radicals' — 
the one usually juet^dlie; tbe other eomnn^nly a tioa-riielallic, 
aim) lie or eomjdex, iteid radical In tbe followiug paj^es tbe 
metallic radieals will Ik* eouHirlere^l tirst, the aeid radieuls ufter- 
wanL Eaeh radi<*iil will \h' .studied from two point** of view, 
the Hvutbetieal iiud the aniilytieal ; that i.s t^^naVp the pr^»|K\rtie8 of 
an element on whieb tbe prepu rations of hn eonijioundH dejienTi* 
will be illustratiil by diserijdioiiK id* aetual experinietit^, atid ihuii 
fi knowletltre <d' the [♦rineiples of eheniislry and of Ibeir nppUea- 
tions to medicine and pharnuiry he aef|uired; then t!ie reaetions 
by which the clemetit is det*^el<f«i, thou^li «'onddiiedl>y other sub- 
stnnees, will lie performed, nnd ^<» the student will In* instnJi'ted 
in ipuditative analysis, Syntlietieal and analytical reactions are, 
ill truth, fretjuently identical, tbe object with wivich they are per- 
forrntHl g^ivin^ them syntbeticid interest on the one haiid^, or 
analytical interest on the trther. 

A pood knowb^lire of chemistry may he ac4|uircd i^yivthetically 
by preparing considerahle ipjanlitie^ of the Halls of the different 
metals, or anulytii^ally by jroinjr through a course of pure quali- 
tative unulymH, But the former plan denuiurlii a larjrer exjH»ndr- 
tiLre of time thnii mont iflutleriLs have to spare, while under the 



/ 



POTASSrUM, 71 

UlU'r nyrttein pupils geiRTuUy lose e?ight nj' the .synthetical impor- 
tiiiice which atliieht's fu juiulytiml rem-rious. Heiii-t iho nmrv 
Unoful system, now t^tiereii^ of htmlying each iiifUil, etc*, from both 
j>c»itiU of view, time being eeoriotiii^sed by thf apenitor prepuring 
iioly sumll ftpecimeiij* of coinpouiit Is. 



jSV*'. — Aa ft geueml rule, throughout tbi« Miiuuul, pam^rupbs 
liesionbitig experijiieuts t^i be pc-rr^>njie<i are tlistiuguj^hLMJ fnmi 
paritgniphrt containing matter merely to be rwid, by Ix-ing [►riuteii 
iu i^nnewhat larger type. 



THE METALLIC RADICALS. 



POTASSIUM: K. Atomic weight, 38.86. 

^rtf^itt^r, etr, — Tlit' (^laicf Bourccf* ai tlie potasnium Hiilts are 
thi* rhlori*le fouml at Stan^ifurt., in Prussia, eoml>inr<l with matr- 
n<?^ium chloriile ill the mineriil CantniHtr, K* 1, Mg^-'l^jHIjO and 
with niagiie.iium r^ulphate in Ktiinitr^ KtJl,MgSo„ i^l^O; the 
nitriiU^ found in »<»il*4, I'apeeially in warm countries; and thr com- 
puun<h» of pntaRsium existing in plants. The iiutaKsiuni Halts 
pr^'^nt in |»lanU are converted chiefly into carbonate when the 
wotkI or <it!ier part.n are burnt to allies. If the ashes be bxivi- 
utefl with water, ami the Hobition evai>orated to dryne?4>^, the 
ffHifJuc when fu^^t^d constitutc-s erttdr poftf^h*>. Tlu^ ri>iidue cal* 
eificd on the hearth of a reverlieratory tiirmice till white, given 
tlie product terinrHl /jrrtrAwA, which if* impure pota^^iurn i-ar- 
boiiHte, Large (|uantjtie.s of iHitan^iuui carboiiute are tbui* j*ro- 
l^iieiHi tn North America and RiiKsia, ami, latterly, fnnn the 
«ugar btvt-n»ot marc^ in France. Nearly all other pitassium 
CHupouttd^ are made from the native rldoride, or from the t^ar- 
bonat4t which hm been purified by tn^ating peurlaHh with it,** own 
weight of <listilied water, filtering, and evaporating the wolution 
mi Ojrmed junt to drynen^ wbih* it is kef)t briskly agitiiteil. Ex- 
('4*p(ionf^ m;cur in fM^tj^sium nitrate, and in cTcani of lartar 
(Ptitiunii fiifttHntJt, V. S, 1\). which is the more oriels purified 
niiturnl potiiKsium t^nh of the grnpe vine. Pola.s,Miura, in the 
form of one or other of it^ compounds, }n a conKtiutent of over 
Ally chenjical or gali*nical pre]>aratir»ns nf tbe PbariuacopaMa, 

/V/iarrt/iwi,— Potaj<*^inm itsidf is iw dated by distilling n mixture 
of pot««*iuni carI)onate and charemil at a vrry high ti*mperaturt% 
or by (WtnerV meth<H] (^nrr SHlium). It rapidJy undergoes 
oxidation in the uir, hence ix usually kept below the Murfuce of 
minerul naphtha wliich protectn it from oxidation. It erystal- 
Uien in oetahedra. 



kui 



(T/^ 



.4 ir'.'.^A 



Ili 



THE METALLIC RADICALS. 



PotMH.siuiu cjirbimatt' {/*ot*i^j*fi ('(irbofHi^, U. S, I\), is ii white 
tTystallifir or giaiuihir puwdtr, insohibk^ in aln^liol l»ut very 
solubit* m \MitA'r yielding a H^lulimi whirb i» tilkuliiK; ami uau-slic 
t<i tlii^ tiuste. It rapidly ii(]uu(ie?« in ilu* air tbrnugb abMirptifiii of 
jiinkturf. 1 1 lorti'H all water ut a re<l boat. 



Potassium Hydroxide. Caustic Potash. 

Experimeat 1, — Boil lugetber fur a ivw nijnult'.s in a busiii, 
teo lo twenty grains nf jmtiii^siuni rariwinattf* K„(j( ^i ^tii*l ^ 
likt^ i|UiintJty of eukuujn bydrujcide fsbtke«l linii-), t'u((>H i,, 
uidi a !?iimll (juaiitity of waler. Set the niixtyre asi^le iu a 
dofiwl vei^i^el till all solid matter hiii? subsideiL 

Tbo elear Hiiuid is a sifluliuji nf jn»taj<siuni bydroxide tir caustic 
pntaLsh, Ki*IL Made <d' a ]ire»i-rilu'd rfnifentrutinn (about o per- 
ctiit.) it furnis Lit^tmr P^ifaMnii Ilf/tiroj'itii^ V. 8. P. 

The mixtnre is known t4> h^tve liren bi>ik'd lon^ enough vvbt'h 
a little of the clear litjuid, ptmred into a test-tube and wanneil, 
given no eflerveseeiiei' on tlie addition of n\i aeid (sul(»hiinc, 
bydnnblorie, or aeetie)— it te^t tbe nimle of action of wbieb will 
Ik* explained hereafter. 

Sft/iil Cfiuntie Pffffijth. — Sfilution of eaiiKtie |M^tiusb evaporated Ut 
drynesH in a silver or clean iron vcRsel, aiol the residue* fust^d and 
ftonred into iiiradd^, con^^tituti*?^ ijustic |ii>ta?^h {Pafamii I/tjtlnui- 
(fttm V. H. I*). It often contains chlorides, detected by means <if 
ftilver nitrate; and sul[dnites, deU-eted hy means c»f n bariutn 
lit ; as described suhsetjucntly in comieetifin with hydriM-blorie 
'"and suliduiric acifls. 

Rrprrnrttfhtff Chrmtrnf Chnufje^ b}f mnirtn of E*pi*iHfinn nnti Dm- 
fjnutiM. — It is desirable that tbe student sbould endeavour to 
n*| I resent each chejiiical ehange that conicR uncier his notice by 
means of an eqUiitiun or iliagritai. The mode of t*onstnietinjf 
Ricb iMjinitions stud dia^'^raais has been exjdaiued aln»iidy. and the 
wtud<*nt is HWJire that the cbicf dsita reijairt'd for their construction 
are tbe ffo'nnibe cd' the variouH f^ulistances which enter int<j and 
are pnalueerl by (be jnirtiiMilar ebangt^s under consideration. 
Thus, solution of potjissiurn carbonate and ealcTUrn hydroxide 
interact wlo-ii boili'd together to [iroduee etdciuni carbonat** and 
pobiH^ium hyilroxide. It is necessjiry t^j know the fornmbe for 
all these HubsiHUces before an e<jnation or diagram can be con- 
st met c^l to re]»resi-nt the inlcraction, Tbe re»|uired Ibnnuhi* are 
n/«j.ee!ively, K,C<>,, rajOH),, raCO,, and KOH. A few mo- 
menta' reliection shtadd enal>le the student to |MTceive that in 
order that CaCo, may Iw built up frouj ('ji(OH)j and K.CO,, tbe 
bitter of these two nuist give up K-^ while the fr>riner nuiM give 
lip (OH),; and, further, in onlcr thnt tb(* K, and tbe (UH), may 
be conceived m fortning a substance having the formula KOH, it 



I 




supposed tlint Ihej^ mak'riiilH iinHo to form twn KOH 
grtjupit. 

A rliiigrum rep resell ti II tr the chanj^e rsiii then be eoristnitted 
»ilv tbuf* : — 




Quatiriti written thits : — 

Ca(OH), ^ K,C<>a = CuCO, 4 2K()H 

The interaction repre»etited by the alnive Uingmin and equation 
m mi inKtanee of that kiu*l *jf ebi'iuiral eii3iii|L^e eoniiiionly tiilled 
di/uh/r iUcomfm/fifion, thi' twt) inftallir rudiialf* exebanging |»Iat'e;^. 
The liaine mditihrnij* {tuTii^ mrfu^ bfyorul, ait<l ikmr thenix^ a 
placing) is m>nietinie.H ^iven to interaetioiif* of this (lej^eription. 

At the name time that the Btiidont in eoDHtrnrtin^' tliesr <lia- 
jcniniH. and t'tjuiitionn I'ur hiniwlf, he will earefully In'jir in mind 
that ea<*li formulii stundf^ for a dftiiiite qmuitity of the s^ubstnnee 
which it repri*<inilK; and thiit, by adding up the cpiautilirs thus 
indicated by the rormuhe nmr^iitutinir au cquathin, hi* c:m readily 
aMHTUun the [(riijifirtinnH by wci^dit in wbieb the t^ul>wtance» 
mlomc't tttid rc?<ult Irom interaction. 

Sulphurated Potash « 
Bxperiment 2» — Inio u test-tube pnt a few pruini* of a 
mixture of i^/vt/omm/v ilr'ud jMitasj^iinn curiwunite and half its 
wei^'ht of .Hulpbur. [{eiit the mixture ^'^radimlly until it no 
lon^^er eHerve,sce?^. The resulting fused lunss iHujrcd on a 
slab and quickly iHHtleii is 8ulpbiinit«d fM>tii>ib. 

Pi»tJi>«lum 8iilrihur Potii8»1uni P<>tn*«!tim riirl><»iilo 

mrtwrnHn* thiiMuliihnt** tritiiil|>liide fiiiliyclriik' 

A»* Diet With in pharmjicy, thi^ Kubstanee in not a singlr <lcHnite 
chemical eoinp«iutid, but a aii3ctnre of several ; in nhrtrt, it^ 
rheniical character in well indicated by it^ vapje name. When 
fw^li, and if cHrelnlly prepareil *vitfi dry iti^'rcdient*^. it iw nf the 
i*ohir iif liver (whence the <dd name '*liver of sulplutr"), anil 
coni^iAtjtf a."* Hhown by .L Watt.s of the h\\U mentioned in the 
fofe>n»inir equation, ti*^*"lber with a little nndeeomp<>K*'d poian- 
iQuni carbonate, with pcrhap?* bi^dicr potassiuui .Hulphide> (K^S^ 
and KjH^)* Hy r3i]»tdly abHoibini^ oxygen tnao the air. it soon 
hei'imiew green aUfl yi'llow. potassium Hulpbite, K S(»^, and ■^ul|>hite 
i^W)^, \H*\n^ Hueces.'^ivcly rornied, and ultimately a UHelcM.^ riuL-^** of 
A dirty white color ri'^nltH^ eonsinting of potJiM^ium sulphate and 




74 



THE METALLIC RADICALS. 



ihior^ulphiite, with gencrnliy sumo cnrbonsik* smd freo i^ailpljur. 
Murwjvi r, if i>verlH'itk'<l in tiiiiHiufartLin', i\\v |»«rt:b^iuui t1iif>sulphate 
in flectJinpoHt'il ijito Kul|>luite and juMitiiHuljihiilf (4K^*^,,( >a = iiKjSO^ 
-\- K^j). About iirtv pt^rctut uf llic fi\',shly-iiiadL' prejmrHtiori 
should bt' scduble in iikuhol (IK) inrct-niL ). It is tx"t'jii*i<»nally 
empbiyed in the Ibrm id* nintinciit. 

Tbt' L'luijjilifiited naturt' i*( thr iiileriu'tioiis that take jdare iii 
this px|M'rinieHt will proliably cause lailtire in iiiiy iiUeinpt by the 
stuileut to rvjireseiit ttiest* by Mieiin,s <d' a diagram witlioui llif aid 
(»r the i>riiited e(|uation alreiuly given. He may therefore einileut 
liiniself, in tiii?* eftse, by ijitroduein^ into iiis note-book a diajrraitr 
founded directly on the i^juation, and on the munbera of inole- 
eide?* there stat*Hl. 

Ill pre[Kiririif( lar^e quantities of s^ulphumttHi potash, tlie 
te.^^t-tube is rephieed by an enrt hen ware rrudble (p«^88ibjy 
froni rrux^ a itoss, for ori^iually a cross uas inipresseil ujxsu 
the rtieltini,^-|Kit used by alchembts aud ^^obismith^ : otliera 
derivt^ the word from enir^ an iustruiiit5at of torture, the 
Si^ use he re I >e i ug sy m I jo I iea 1 ) . 




Uniting cnicibien. — Cmcible» of a few ounces capiidty may hQ 
heated in xui ordinnry fire* Larger ones rw|uirea ftimarc. Kven 
the HOiidler ttneH are more conveniently and quickly heated in u 
furnace. Half-onn^'e or one-tmnee experimental poreeltiin crucibles 
may be heated in ii spirit or ^ix-tlunie, the tliinie of the liunsen 
burner alre^idy ^ie.seri^>ed iK'injr ^eneridly the uirwt t*«itjibli\ 

Potassium Acetate, 

ExperimeEt 3. — Place twenty trrains or so of potassium car- 
bonate in a gniall porcelain di^b» and Maturate ()*ntur^ ftill) 
with acetic aeid ; that is, iidd ii<*etie arid an baig iis efferves- 
cence IS produced; the re^tiltlni: li<|uid is a slight acid solu* 
tifiu of |K»luKsiutu acetate. Boil aW inoHt <»f the water in an 
a|)en dish {See Figs. 17 and 1^^), stirring with a glaas 




Evftpomtioti fVoia umaU and lar^i* basins. 

vefi^el. the a<*C!tiLte m liahle to hecome slightly t'liarn^rl mul 
disculoreil ; this i?* prevented hv IninHferring the solid residue 
to a les*t-tul>e or thwk hefnre tiiiully fu^siii^'. Fotu^sSiim 
ac*f«rnte forms a white deli(|ijes<'eiit folimwms Hiitiiiy riiass, 
neutral to test*paj>er, aud wholly &<*lulde iu ahtdiol. 



PtiUdUiitim 
rArb«iiiale 



Acetic 






4- 



n,o f CO 

Water farbonfc 
Auhycjrlrle 



fCrjitantiHon of fnrmuhr, — Tin* (oruiala for aeetie acid (hyd- 
rtijucn *ieetatp) is IJi';^}!,*)., nud tiuit lor |i(>ta,Hsiura aeetatt% 
K<.?jH,i),. Tile uriivuli-nl ^mnyi or radieuK <',H.,n,j, is cuinmou 
tu all »iH*taU*}4. A iu<ire extended Jbriiialii lor p(>ta«*iuni lu etale, 
indieatia^ the |»4isHil>li" arraii^'aieiti of tiie at'oaiH in the aioleuule, 
to ClIjJ OOK, 

IHngram of the rrarfion. — The nature (if lh<' ah(>ve ofwration it* 
indimtei] l»y an rfptnfion ; it (tuid HUereeding reaetioaH) laay l^»e 
^%\)tv^*»*i\ in tho Ktudi nl*H a*jt4*-ho<>k iiAnfiitiffrajn^ and» if p<>f^«*il>le, 
witljrmt tlie aid of the above efjuation. 

Xofr, — The l<»rt'fffHni; reaetinn han a jifi-nend an wi'll as a 
f'tNiml luterei^t, 1 1 repres<*n!H tmv of the eiaiuaoneM aiethodH of 
fortjiin^ «*jdtH, naaiely, the rh'r<>rii|M>sititin of a mrboriat** hy inter- 
iirtion with an aeid. CarlKaiaU'H addi^l U> aet'lie arid yield 
at>*tttt4?s^ tn nitric aeid nitrates, U* i*ul|diurie acid wulphatea. 
MAiiy illii8tration« of thi?* ifeneral prin-ewH cK^cur in pharmacy. 

' Clliixs riKl y aHiiiilly pitrt^liswd iu 1cii|rihi$ t>f 5 or 6 ftn^t. Tht'st* may Ins 
rttt Intn wmvniifMit pif»f'(?*4cjf froiu li U* VI iucluii loiijj U« p, *2\), HUnrjt«»ndfi 
htittg ruundcd ulT hy h(»li1iiifc the i_'Xtn<iuitii's iu a Daiuc for a few iiiinyR-s. 



76 



THE METALLIC EADtCAI^. 



Enipoi'ntiott **I* wattT JVriiii u litiuid is Ix'^i rtindueted in wide 
shidlfjw ves-^i'lH nitlier tliJiQ in ii:irRiw devp hjjl.h, iw the siviuu tan 
thus (juit^kJy ilitl'jiKe into the air and niitidly W Cirnvt-ved away; 
hence a i^mall nmiiddMiltojned ha>in, hiated an shmvri in Fi^. 17, 
iH i'tif morv HuiUihk* than a t<\^l-TulH* tor sutdi operalicHiJs. On the 
uianuhu'iurinjj: seale, in^n, t)T inm Jineil with enameh or ^omi- 
porcelain^ lupja^r, tinjied cnpper, nr m>lid tin t>aiis are u.Hod. 1^(j 
to 12 or 18 inelies iliarneter, inirtrlain dij^lieH iiiay he emphiyed. 
Suiall dishi^-rt may he Kuppt^rted hy retort HtaJHln (Fij^, 17), lar^rer 
by ( yliiah'rs {Fig. 18)^ to whicli the dink in, if less in diameter 
than the ey Under, adapted by sueh flat ringij nr diaphragui.s at* /ire 
shown ifi the figure t>n jiage 75, 

Potassium Bicarbonate. Potassium Hydrogen Carbonate. 

Experiment 4. — Make a eoneeiJtratc*d *i<dution of j)ota88iuni 
carhonate hy heatin)! in n ic^Ht-tube a niixHjre of j*evtTal 
graiiiH of tht* salt with rather less tlian an equal weiirht of 
water, ThrauLrh the e^Mil dilution pa^y* earlM_aiie anbydride, 
slowly htjt eontinuouj^ly; after a time a white ery^talUiie pre- 
cipitate of j>otai=.^iuin hydfo^fen enrbianite, (*r [Kitassiuni bitur- 



I 



twaate, 
forme<J. 



KHCOg [rotamii BirnrbonaH, U. 8. l\), will be 



earboniite 



H,0 



CO, = 

CHTbontn 
iiohydrirtc 



2KHC0, 

f'otiywiuRi 
l>trarl«)n«to 



Generute the earlHinie anhydride by addiu<j: hydixtehhirie 
aeid, dihjted with twiee its lujik ot* water, to a few fragmenljt 
of marble or other earbonate euiilained in a te8t-tul>e or 
mnall riask» and eondiiet tlie ga,« into the s<d«litm of [xita^ 
siiim earlKmate through a jrla8,*i tube, bent to a eouvetiient 
sluipe and fitkHl to the teist-tube or Hask by tneani* of a ei>rk 
in the usual way if<ee Fig, HI, p. '>4), though no heat is ue<^es^ 
eary» The tube nuiy be rej>ienished with marhk' or aei«K 
or botli, when the evolution of gat* is bHoiuing i*luw. In 
working on any larger rpjantity than a few graitis of tl»e 
earbi>nat'\ a wale del ivery-lyl>e should be enijdoVHl ; or if a 
narrow one is employed, the einl of it nujst iMM^asionally la* 
cleared from any 1 dear Inmate thai may have l>eeu de|K»«<iltHl 
ill it, A more et^onomiHil arrnugemei*! of the apjmralus 
eai|doyed iii thin prtK-es^ will be <le.scTibed ainler the eorre- 
fipiraliug iiodiuiii ^ilt (p, HH). 

DrptMtitian of thr hintirbotutte r.r/?/a»«rr/, — |*otassiuaj bicarlionate 
b to ft certain extent Moluhle in water; but as it is It^fie m than 



I 
I 




POTASSIUM. 



Ti 



ihe fiKiUi^ium carhonnte^ and an a t^nturttied soltitiiin nf Uic hitter 
i?4 eni|jlc*ye<l, the lU'et^iiHtutidn of a (mrt of thr bi( nrlHiiiatt" iiii'vi- 
tJibly oc«'ur». hi iiIIkt w*»rtl^, tlif t|iii*titity of wsittT [>R>oat is 
tmlKcit'nt U.i ♦llHsolve t!u* larbrmalr, Imt iiisiHfirieiit h* n-taiii in 
m>h]tioii the whrilr of thi' b]L"irlMui;*tf» fornu'cl ♦lurin^r flir at tion. 

ProfK'rfirx^ — Pn^|Kiri't| on th*' larp: s(*a!i\ |iotas.Hiuai IVirarlMuiatc 
f»ccu!> in it»i(»rlesj4j non-dt'Htjnescint rhinnbu" jinsinis ; it has u 
^lin(% ft'i'hly alkaline, iion-rorroMive tiLstt\ Heatetl to ri'ilnen?*, 
it lo.'iea alKait 31 iM^n-ent. of its wt^iglit, and is t'<jn verted iiitu 
[Mjtufssium ciLrbf)nat<\ waUT, and curlionie sinhydrido» 

2KHCn, = K,(JO, H- 11,0 + OO, 



198.82 



137.27 



17.88 



41U>7 



The foregfiiiig eiiualion jind ai'roinjmnyia^ wi'i>rhts {Mrr pa^e GI) 
hIjow how |Hjtjt'4siuTu bu'iirhonatt' lows "^ J prnvnt. (17,>^8 | 48.t>7 
tn 198.82) whi'n ronqihttly drt'()ai|»oKed by heat. 

Xntrjt tm XofUfur/ttfttrr, — The prelix fti- 'u\ tlu' name '^potaKsiuni 
biearbonate/' .m*rvi*f* lo reeall the faet that for the snuw <iuantity 
of pitjisrfiuni thin yydt ri>ntainj^ ftrirt' a.s niueh earljonie nv'nl 
rudical as i« present in the earhonate. Thi' salt is really a 
**fjola,S!iauui ami hydrogen earbonaUs" KIH'O,, and iw inUa- 
mediftti? t>etwt'i n potassium riirbonaie, K/.^O^, iui<l hydrogen rar- 
bt>tUiU% or trut' earlionk- ^leid [Hj^Mlj], It i« ^'polasHiuin arid 
'48»rV>^)nate' * or "poiassjuni hydrogen carbonate/* and is an aeid 

ilt» inasmutdi as it o^ntaiiis hy*irogen vvhieh is dis|ilaeejihle 

by nu'tal U> form a noranil salt, altliongb it m not ueid Uj the 

t4WtC, 

Hnha whose speeifie nunies ead in the syllable *S7/r" (i'arf»onf/^r, 
%nlphafr^ etc".) are in general eonvc^itionally so t4Tnietl wbea they 
ciHit^iiii the radiea! (or eliaraeteristie group of elem*'nts) id' an 
acui wlioe*f name endn in *'!'*/" arid from wbieh aeids thi^y [nive 
tpceti or amy he formed. Thus the syllahb? 'v/<<'/' in the words 
i*ulphf*/r, n'livtfr, m-iUrff^ earlM*niffr, et*-., imlieates that the ri>- 
iip<H'tive sjilts eontuin the* nidieal of an ari(i whose annie ends in 
(ff, the pr<'vions Milables sulpb-, ai'et-, enrboa-, indicating what 
that aeid iH— Hul(4mrie, nitrie, aeetie, or earlnaiie. <)ee}i>i<mally 
A h'tter or syllable is dropjKMl frran or ad*led U* a wc*rd to render 
tho nann^ more enphouitais ; thus the t<nlphurie radieal formn 
Mufjthfiirjt^ not Kulpinirates, and the tarlarie ratlieal yiehlft tartnttrn 
not tarteirates. 

Potassium Citrate. 

Experiment 5. — Diaswdve a few jj^nuiiH or more tjf fx>taKsrura 
C0rlNinate in water, and add eitric* arid, H^CJI.O,, until it no 
lotigrr fiiuM!» eft'ervewmee. The restdtin^^ li<|uid i?^ a i*cdytion 
of pi^tjy^iutu citrate, Kj^CJIjO,. Evaporate to d^>^leKs, iu 



J 



liKlltyi^O, 4 K,(X^ - 


■- -J<.*'|lJ/*ii ^ ^*.*> 


Pr>tii^*iiini PiifiKsiuni 


ri4iis«(iiim 


Walor 


hjMlnici'Ti Hirtmto cnrltrmfito 


tJirtmU' 





I 



78 THE METALLIC RADICALS. 

an ojwii ilLsh, emit ii>u sly s<j hh to ixxmd eharriug; a pulverulent or 
granular residue ia olitsiiQed, wliirh is the ofticial fxjta^j^ium 
citrate {Potamii (Vfrcw U, S. P. ), a white < lei iqupscpnt powder. 

3K,C0. + iJH,(;,H,C), = 2K,C.H.O, V 3H.U ! .KO, 

Potiut«lum Citric iu;icl IViUuniium Wuk^r (ArlM^inc; 

carbntiAtG citnik- anhydriilc^ 

A gniiiuhiti^fl mixture prpfiarnl tVutn potiLs^iuin i'itrak% Modinni 
bitmrbunat4L% and tiirtjiric arjd fitrii' arid is otlkirtl (Fofajft^ii CifniA 

Vitnitf*, — The citric radit-al, C^HjO/'', which with Ihrvr 
aUiiiiB of hydrogen turinH citric acid, and with throe ciT poUu^imn 
f(»rni« pnttiist^iuin citrate, i« a trivalunt jy:roa[>. An cxteiidLHl i'orui- 
u la fo r c i t ri c ac id '\^ V < H ^ J 1 1 f , ( t H M ) H ) ^^ \ \ ,( j^ that fVj r pn taK^i a ai 
citrate Ixing (yf,.(>lIjC(l< *K),,H,i). The cheaiistr)^ or citric 
aci<i and either citratt^a will he def*cribtid «ul)sit|uently, 

Po/njiMtttm tiifniff, KNO^ (rofa^it Nifrux i;. S. 1',), iiad Pf>ta9' 
mum mi} thai r^ K^O^ {PotuAJtii Stt/fJuyt^ U* 8. 1\ ). The^e salts 
could sdso hi" iiuide by iieutriiliziiig nitric acifl, HNt>^, iuid sul- 
pltnrie acid, II./^0^, rertperlivcly, with polaRHium earlxmate. Or- 
dimirily they are not inaiie in thin way — tlie nitrate iireurring^ as 
already stated, in natnre, and i\w sidjihate hrin^ f»btuined as a 
by-|)roduct in mimy operatidUH. lU*i\i Haltw will be alluded to 
later in connection with a i trie acid. 

Fotassium Tartrate. 

Experiment 6. — I^laee a few grains of jwtaR^iiim carli<inaTp 
in a leHt-luhe with a little* water* beat to the boilinK-iioiiit, 
and tbeii add acid f>otassiuin tartrate, KII<'JI/V^» till there 
k no more efferve^eenee; a 8<dutioii td' normal jiotassiuiij 
tartrate, K..C\H/\, n^iults, Prismatie eryt*tal8 may lie 
nhlained mi eoneejd rating the solution liy eva|M>ration and ^ 
f*eltin^^ tbe hot liquid a**ide. larger quantities are niaele in H 
the wime way, 20 parti* of ]M>ta.«sium Imlmgen tartrate and 9 
i4* (KJtassium earlHitiate (whh 50 of water) beini: alwnil the 
proportiiuiH ntH*e't*wiry for ueutndity. 

r»rb*ttiU' 
jinhyitrldt' 

f*oias«iain Uirlrat** i?^ Hligluly deliquescent, and is s«»lnble in alnint 
four (mrL^ of bc*iling water. 

7*ir/rri//*^. — The hivalcnt nuiit^id ( \H,<\" is rhariiclrnjitie of all 
tartrj*t<^; lience the formula ol' liydnip'n tarlrat**, orlartari*' acid, 
is \\.i\Hp^: that of potiissimii' tartrate in (K/\H^n^)^,H,( ); f)f 
the intermediate ^jilt, acid p»)ta«t<inm tartrate (cream of tartiir), 
KHC|H^O^. If the acid tartrate of on^i alkali-metal and the eiiiv 



I 




POTASSIUM. 



7» 



Ixiniite (»f another interact, a neutnil tiirtmte ret^uUu'*^ which i nri* 
Inin?* kith ruetiils, as seen in Hufhelle siilt, KNiit\H4<),,4ll,n 
{Pi^tujseii d Stdd Tarlnu^ U. 8. l\) Mtire extended tbrmulfe uf 
IhcBL' naltei, inil i eii ting constitution » are: — 






[(CH(*H),(a>OK:)j,, 11,0 

Ptitiiiiiii u m tart raU' 



Avid StilU (e.g, KHt'Jl/)^j, that is, Hult.'i internieiliiite in eoiii- 
|N>Hitif)n between a nf»riiial wilt u.y. K/'jH^t\) ami an ai;id (r.c/. 
H/\H/)j), are frinjuently met with. All iidd rudiealji, cxrejit 
llnM*e which iire univalent, may be euueerned in the fonimtiuu uf 
f^uch acid fialt«. ^S^ p. 66. 

Potassium Iodide. 
Experiment 7. — Into w Hflutitm i>f' pitossiuni hytlroxide 
bfated id n test4ylK% tJa^k, cjr evnporatinjL'-i^n^in, a€r(*rdhitr to 
4uaiitity,»tir a little mWA iiMliuc. The deep culur of the todjue 
liimippe^ir** etitirely- This is due tt> the formfiti<jii of the v\ dorless 
aaU>i, |K>t!i^iuni iiHUde, KI, and [Ritas^siurn lodale, KfD^, which 
remain (ii8S<dved in the liquid. ( Vnitiuue theuclditiou of iodine 
po long as its color, after a few nuiiute?*' vvaruiiutr and stirring, 
flij?iip|)ear8. When the whole of the jK^lassiuin hydroxide m 
the !4tdution has been con vert tni juto the 8alt8 mentioned, the 
sli^'ht ex<x^5W of irwliue remaiuiiig iti the liquid will color it, 
sod thus 8how that this stage of the operation is completed. 

BKon 

Seftanilltm of the UMVide from tlw iodatr. — Evaporate the 
{"nilullon I0 ilrvnef»s. If iHitb .hilIIh were re<|uired, the re.^ull- 
in;5 mixture mi^'ht he <li^esteil in aleohid, which distsolves the 
iodidt* hut not the itwiate. But tbe iodide only in needech 
hilimately mix the residne, therefore ( ref»t*rviujL' a graiu (^r 
two for a 8ulwe<|uet»t experiment ), with exeeg» (about a third 
of its weij?bt) of eharcoah ancl gently heiit in a tet^t-tulie or 
erudble until ^Ji^^it detlagration ensues.' The crueilde may 

* If, in t\w ofM-nitimi uf hi'iilinu {Hjt»iHK)ym itwiiOi^ wirti «j'tiJirro;il, i'xci'Ks 
of Uur tattler Im/ «'rritilovi^, Hligtit inrjimliiM < lut* rntlnr than drflajunttiMii 
Oix^itrH ; if tht" < lmrc'H»l W iarifiily in excf^i*, thi' ri'diirtiori *if llu' jM»t;i*y<iiiiii 
iudjitc to itMluIr is jifTiH^i'tl ^'itltiiut vi^riilr ili'tlii^niti(»i) or «ncn imMiinh'^- 
rncc* fVifln^riHidii niojins vioti lit biiniiif);, fruiii fftitimtuM, Ininit i tt'i*iHK 1 
biirtiy, litul tU, 34 iin'Tix uii^ittrritiii^ tlic f^nitv i)f the wunl towhicit it niuy 
tn' dttikchf^l. t'lifM'r thrown ititit u tirf^ .dimply hiiniN. nitre i-auHeA ilrflii- 
lcr»tMin i»f thr furl. t>i'ton»1it»ii idf'tfma) i»aHiiuilHrly cuiiMrticte<1 wont, 
tni*iini)»g uxplcfsion with viulent Tiiasc. 



31, = 5KI f 


KIO. -f 


nij} 


Iiidlne Pnuywlum 


Potfl>«iani 


Wfttii- 


ifrfJidc 


iodale 







80 



THE METALLIC RADICALS. 




he supported in the Hanie of a spirit-lutiqj or Bunsen hiirner, 
or phireil lu a tiri' or funuu'e. The iotlide reiiijiin>i uiinUk'teil ; 
hilt tlie iotlute lot^^a all its oxygeu mul iA rt^ilueed lo the Mute 
of 'u)irHk\ 



KIO, 






= KI + 

iudJde 



3a> 

t'lirlitinic 



Treat the niaj*B with a little water, aikI filter lo 8e|mnite 
ex('e;^*« (irehsimml: u wilutioii of pure |M*las,siiiTn iiHlide resyll.s. 
Tliu hitter msiy be used tLS n reagent, or it may be eva^^ 
unite*! to a small liulk and set ui^ide to rrvi^lallize, 

/*ritpt'rftf'A. — iSit^irt^iuaj iodirte {Pofmitn httfititun^ U. 8, I\ ), 
tTyHtulliKes in Hiaall i tibii al crystals, very swduhk* iJi water, k-HK mi 
hi ah iiIjoI, KxjHjist'd to iiir and s^anli^hl, jOire potit'^^inia iodidu 
benijueK sli|::litly browa^ owin^:, pniVialily, to tlir n*aih]ai«l aition 
of the <ixygea, water vapM>r, and caHjonir anhydride i^fthe atmos- 
J > he re. 

The fvlflitifm of fharrrttjl in the alxive proees*^ in siai|«ly to 
facilitate the removal of the oxygen tKan tlie polim^iuai inflate, 
rola^siinii if»date, KIU,, is anahi;fous in roai|jof<itiuti lo puta^HHium 
chlorate, Ki'U),, wliirh hsH alrcjidy twH-ii staU^l to \n' more gener- 
ally usi'd ttian any other salt for tlie aetmil ]n'ej»aratioa of oxygen 
gas itflclfj and the rcmnval (jf its oxygen may la' ace<jni[dishod 
by heating the rL^sirhn* without eharcnaL la tliis^ caw the liber- 
atOfJ f»xygen L'an he ih-tcctid by inserting a glr>wing strip of wood 
into the anaith of the l(^t-tube in whieh the aiixtiire of icKlide 
and iodate ir« taking heated. The charcoah however, remove** the 
oxygen aiore qnifkly iin*l at a lower teniperature, and thus econ- 
omizes both time ami heat. 

jh'hrtion a/ itKhfft' tn iO(titfi\ — I^fitaHMiuin iodate remaining aa im 
imjiiirity in |>otaH.siiirn iodide, nniy be deteettnl hy adding to a 
fMdntioa of the hitler :^nlt s<iaie weak acid (say, turtarie), Klmking, 
and tln-fi ndding starrh mneiUigr; hhie '^iikImIc of stjireh" {i*re 
Hlareh) is f<irmeii if a Iraee nf iodjile 1k' |>ri"Kent, Init nt>l other- 
wisie. By the interaetion r^f the added aeid and tlie fMilawiuni 
iodate» iodie aeid, TITO.,, is [irmlneed; and hy interaction of the 
addinl aeid and ihi' |)r>tassinoi iiHlicbs hydrifidic acid, HI, is prt>- 
dui-pil; neither of these ahau- attack:^ standi, but hy their niutnat 
internet ion they yielcl tree iiHliiie, which then forms the blue cob»r 
hy it.s Hction on the sfjireh. Thii* exjieriment stiouhl U' tried on 
n grain or two of pnre iialide and on the impure iodide rej^erved 
from the jireviiais exjierirnent. 

Potji?isium ifwlide containing i«Hlnte woulcl obvitnisly yield free 
iodine, wliitli is cxecsHively c<*rro»ivc, on the aidt^* ci>ming into 
contact with the acid?* of the Htooiach. 



I 



4 






POTASSIUM, 



81 



NMf on Nnmeticlaiure, — Tlie iinul syllalile ule in the nanie 
potiisHiiim liKlhlf, ifuJicitlei!^ tbut tiie rlrmrnt kxline iri aniibint'd 
with |>otii!v>*iuiiL An iodrv/^v, as jilreiuly i*x(>laine<l, is a salt cf>ti- 
laiuiDg thi.^ t'hurncliTi^tit" radicHl o|' iiwl/r acid iim{ nf :dl utht^r 
i<Miate^. Inort^aiiicsalLs whosi* naiiu^setid in idf\ arc d<^riv*.Ml frojii 
jicidfi which do not coiibiin Dxyi^fii. Acids with coiiq^h'x nidi- 
«iU, the hdter itsiially cotitiiiriiu|j: •»xygcri, ^ivc ri.s** to salts with 
tuittic^ ending in ute {At* p. 77) nr itf. An inorganic Hidt whoise 
nmue i-nds in f/Zf * ujitnins the radicali* nl' an acitl who^t' name 
eniL* in if ; a salt whose niiuie cndw in (V*' cimtains the radical oC 
un jicjd wbo*»e name ends in om ;iin innriifanic salt wlnLSt; nitnie 
©nd« in ide eimtjuns im cleincnt h»r it.sacid radical, Thns, an inor- 
ganic «uli>h/<]fe^ tonsi^tHula nretalhc nnlieal cfnnhincd withsuljjhar 
only, while a sulpli^V/' and it snl|dif//c are eoni[»ouuils <if metallic 
rswiicals vsith the sulphnroz/.'^and tln>sul(diurfr acid railicals resjiec* 
tively, an<l so <ai with other inurganie '*ides/' '^itt^s," tir '*ates." 

l*fti*it(finm Hrtfmidt^ {Potiti^mi lirfimithtm^ U. H, R), — ^l^his Halt is 
anaJuii^oim in er>m[>ortition with pi^taxsinni iodide, and is made in 
the same way, hnnnijie Iwing Hultstitnted fV^r i<Mline. The iiir- 
innla of bniniie acid is WMri ),. It will he noticed that the follow- 
ing eijuutionH are similar in c ha meter lu those showing the prep- 
^a^utitm of potiu«ium iu<lide:^ 
Experiment 8.— -Place a Jrftgment of soliri |H>t«Rsiiirn hy- 
droxide, KOI I, with alKntt the sjinie cjnantity of |M>t{issiuni 
chlorate, K(l<\, and t>r black nmii^mnese oxide, MnO,, on 
n piece of phitinnni foil.' Hold the foil, Uy ineans of a 
j^maM pair of tonvps or tou^j*, in the thime of a hlovvpipe for 
a few minuter until the fused ttiixture biu* become dark 
green — apparently hlack. Tbis color is that of poinnsiiun 
manga tiaie^ K .^ ^ f n i)^, 

6K0H + KCIO, h UlhO^ - HK,MuO, H KCI + 311 O 

|V)tAfif(Jiiio iVtiaMtum R]«< k nirtrc IVftn-ssium rotn*M^lum Wait r 
[tf<JXide chlomtc' K<)iie^i' uxMe uiangiinate rlilorld^-'' 

! *Tli« foil may be 1 in. Knwid by 9 in. Uinn. No ordiniiry Hsime will 
lieli the platiiioni, fusi'd auistir iilkalicA only kIuwIv oirro^lr it, and 
wry irv! of licr rlif tiijriU Midgstiiiiirs atrert it at *a\\x hi'iim tin* wone piece 
m»y Iw used in rxiirnrncnlH ov« r and ovrrupiiih Mai^y mituls fumi a 
hiNihlc alloy with iilntiniini, iind phitsphoni^ and urs*'fion>4 (sulphide 
mpidljr JilUM'k it: lictn.-it ^iteh f^ubslAnccH, hh widl na mijcturt:^ likely ttj 
yield them, tihuuld \w heated in purt'tiltdu vrse»elii. 

6 



HKOH f aBr, 


= TiKBr + KBr03 + 


mp 


t^itfusiilitm firrnnjde 
hydroxide' 


Potiutsium PotAiuiiiiiu 
broniidu bromnto 


Water 


KHrO, f- 


\\V = KBr 1 3(0 




pMtJLVMiura 


hromide oxide 





A 



82 



THE METALLIC nADlCALS. 



Experiment 9. — Potasaiuin Penuaugftuate (Potami Per- 

vifutijttitnA f- S, P.), KMuO^. Boil the |>c*tai^ium manpa- 
iiatc" from ExperiiDeiit H m water t'urai^hort time. Potassium 
]>ermaiigauat© ia formed^ and yields a purple solutiou* 



I'liitiLsxJiiin 



Wrtter 






-f 4K()H [ MnO, 



On the large **aile, the jiotasyiuin hydroxide mi tree in the 
reuctioii is rieatralizt^d by t^ulphurie or, lietter, hy earlwinii" acid, 
iiini the sdhitiun is rvsipuntted t*i the i rystidlizin^ |«>ii»L Maiijra- 
aate auiy iilao he cksmj!;ed iutu j>ermjHii^jiijjiit> hy treiitment with 
t'hloriiie. 

2K,Ma()4 I CI, ^ 2Ki1 i l^KMnO^ 

8<iluti(»ns <if [HttHKsium nwuigannte (^reen) or peniumgaaute 
(par[)le) aud the unatr^^ouM Bodiani coanKiundw m\ readily yield 
their oxy^'ea Ut ♦>r;.'^arne aiutter that lliey are used un tile large 
8t*ale as disirifeetaati^. 

Ex]»eriaieats dialing with the reinainiuir oflii-ial poUi8**iinn 
ei»Mi[*f»unds iiiiuiiely, putassiuai hirhroaiate, arsoidte, etih>rale, 
eyaiiitle^ ferroeyainde and terriryanide>, are deterriHl at presinit. 

(VtfafftNizritioii. — This o|KTation will hav<^ het n pertonaefl s^-v- 
eral times in the eotirse id" the forefroin^ experiments. Odviously 
it offers a nmile of sc^paratin^ H>kihh^ erystidliscidde sahslaure^ 
frrMii nduhle amotphonj^ {*t, n, without; ;/r>/K*v. fftorjthi\ t<hupe)^ 
tiuhstaaeeH; jdso of st-[»aratinjr from eaeh othir, hy frnetitmaf 
cryMaUiTatiou^ substauces of varying degrees of sohdiility. 

Anabjtical Rmdiom qf l^fawium SaJU. 

Noif, — Each reaction should be expreswed in the form of an 
equation or dia^mm l)y the student in his nol^ hrwik. 

1. To a solution of any s^alt of i>otassium (ebloride,' for 
example) add a few flro[>s of hydnadilorie aiid and of a 
gwdution of platinie eldoride \u hydniehloric aeid (really 
ehlopjplatinic aeid, ILPtCI^)* and gfir the nnxture with a 
gla.«s rod; a yellow granular or slightly erystalline pr«eipi- 
talje'* alowly forms. This preeipitate eonsis*ti* of jx*tassium 

* A few frajnuents of iKjtasHiuiii fartHmatf, two or three dmtis of 
tiydroc'hloric-acid, and a miwiU tjuftutity of w-at*r, jifive a solntiun of 
p.»t«,s«iiiiij cblc.ride at oiitt% KrtYb - 2Hrl=*JK(*l 4 HtQ ^ CCh- 

' KTcf^eriment-* with ri^ag«*nts eoiitjiiiiinK piatinmn or other exjieDsive 
tTioUils arc eeoiiomically jHTformed iu \vat< ti-glas.se.% drops of the liquida 
livitii; iiperattnl nn. 

* l\y pi rt^ pi tat ion <from prweipftarr, U* throw down Baddetilyi w 
simply nit^nt ifin fnnnarioii of |Kirti<;irs of wjlid in u liquid, no mfttKtr 
whether the solid, the pn^aiiHttttf., ftuhnide or (lonti^, and nv ninttet 
whether the u])enitioii be iwrtiul or I'ompkte* 




POTASSIUM. 



m 



rhlijroj>|jitirmte, K,PtC1 ; it is very »]mnug[y soluble in water, 
ami pnictiailly iut?oUil>le in ak-uhol. 

^rmvrnndn. — When the prei'ii»iliit»? ihnm very tflovvly, it U 
actime** of Jin ontiige-yt^Hnw tint. If jxjtui^iuiu iiwUile bai»f»eti 
lu \h* X\w \H)ias»hnu HiiU under exaininuti^iii, fninptJumU f»r' ioiliiie 
mul platiiimn will Ue fnrnjed, giving h re<l c<»lur tu the Hilution, 
iiiit] u liirger (inantity ni' ihv prt-npUani (that k the prei'ipi biting 
agfiit) will U' n'cjuireiL 

J^^turnliowtl iVo^. — The thnu>rlitt\il Mtnlent will n(4 rtjiifus^o fhe 
Ifnt with the cArwiiVry of thr trj*L The te^nt it.Ht'ir ii[«|Mjil.>, to ilic 
in*nt^^ ; CI jin n lun 1 y U * tlie e> e , tv( j m et i n i es to 1 he n « «*e, oeeiuni on ai ly 
U> the ear. A persim iniiy be able to apply a tet*t, unU yet never 
koow anything of the diemifttry of the t<?»t. 

% Chrnor^ ted for poUt-mnnu—Wix inn^ <lr»p of a solu- 
tiofi of bismuth nitmte with ont^ dnip of n twiltitiun of Huiliuui 
thio«iil[>huie, ami inbJ to the mixture 10 v.v. ur s<j of iihmlute 
alcohol. To the reagent i*o |>rep{uv<l, iidd one ur tmo drujwi 
of a ml u tioti of a j>o tassi urn ml L A y el h i vv p ree i p 1 1 n te of 
fjotaaaium bismuth thiosulphule» K^Hi(S^O^)j, is produeetl 
either immediately or very nearly m (de}>emliug U|M»n the 
oonoeiiitmtion of the solution of th<^ |K)tits,Hium salt ud*led^. 
11* pr(Mlue>eil in lar^e ijuautity, the predptate ^^ettles down in 
a bulky rttxrtnilent fi*rm. Althouiirh iiLH«>luble in nearly 
abetdule aSe^diol, the pre<;ipitate iti readily wiluble in water 
ami in dilute aleohoU hem*e it 18 essential that no eruisider- 
ahle c|mintity of water j^houhi be pre*>enL Very ililute sulu- 
tiuui< of |^K)t4iA<iuni salts shouhl l>e coneentrated by evaporation 
l)efore employing them for thi.s reliction. 

PotUfliiim Bitartrate. PotassitiM Hydrogen Tartrate. Acid 
Potassluin Tartrate. 



IS. To a jMtliilion of aiiy salt of |w»t}iHHinm add excew^ of a 
Btiratetl solution of f«»diijin bitartnite (sodium hydro^'^en 
larlnUe ), NuIIt 'Jl,< >^, and shake or well stir the mixture; n 
whit« j^ranulnr pnM*ipitate of pota.sgium bitartrate fp*taKHitim 
hydroj^^en tartrnte). KlIC,!l/_\. will be formed. If the 
solution of (mln,*^iiim wilt employed i?* alkaline (solution of 
p)»tji^ium eJirl>omite» for example), care must be taken to 
ttdd the jMwlinm hydrojfen tartrate solution until the li<]uid» 
litter thoronjrh mixing, is aei<l to te8t jKi[)er, otherwise the 
pn«cipitate will not be forrmML (S<»lution of imxiium bydroo-n 
tartniu* |iiift«e89ett a Hlniugly aeid reaction. J Teart paf»T, .*'t 




THE METALLIC RADICALS. 



Not f. —By '*exiiem'^ of any test-liquid {mch m the "liolution 
of ?^c>fliuiH bitartnit^^- ' jiinl imiitiiHied) an i^xoi^sively lurge 
qitiiJitity irt nut to be uniierstood, bnt nierety niich a qimutity of 
tin* reagent av, in mnjv thnn snttieient (hiiwevLr little more) to 
eon vert the whole WL'i*j;ht of tbe roni(>oiiii<l jittaekeil into the 
eonqwiund to l»e proi lured. Thus, in i\w (►ref^eut ease, enough. 
H>diuui hydrotren tartrate niutit bt* addiil to t-oiivert the whole of 
tlie fiotii,H,^iiim Halt operated on iuhi aetd pottisMiuni tartrate. 
What the wui^dil of sail operated on was, must be roughly iMti- 
lujUed rnentidly by tlje oitenit<ir. It is not neet\s8iiry in anjilytiwU 
tijM'raUiuis to know the rxact wei^htn of salt.s eaijdoyed. The 
analy*«t nuint use his jndgnient, foundeil on his knmvletljri' i»f the 
re;ietion (tis , shown by an equation), and of the nioleenlar weights 
of lilt* siibstiuiee.s employed in the reaeLiun^ il^ well ati hy Mie 
rough t*i*timiite of the iunount of material on wliich he is experi* 
lueuting, 

LimiL^ ojfhr trjft. — Arid [Hita.H^iuui tartrate is wluhle in ^itH) 
parts of cold ami in 1<>.7 parts of boiling water. Henee, in 
api»lyinf^ the aeid j^oilium tartrate test for potiiKHinm, the S4>lu- 
tions mast not be ln>t. Evt-n if eold, no preeijutate will Ije 
obtained if the solutions are very tliliite. This te?*t, therefore, is 
id" far les,^ value than either of tiie two Hln?ady menti<jned. Aeid 
pota.ssium tiirtrate is le.sH sohihle in dilute al<'<>liol than in water, 
st> that the addition of alcoliol renders the reuetion souiewhsit 
more delieate. 

(Ycnm of Ttirfur, — The pret iidtjite is JhhtJtuii Ilitarfritjt, r'.S.l'., 
long known as Cream of Tartar (althiHigh the otheial jireparation 
is not formed in the above tnani«*r). 

Potassium and Sodium Tartrate. 

4* To surue hot eoneentrated solutitJU of *»o<liuni earboriatt* 
falMJut three (mrls ), in (i testdnlw or larger vesw 1, add jKitJiii- 
eiuni bitiirtnite (nlioutfour part^') till no more efferveseenee 
m*eurs: wla-n the stdufion em rold, ery^^tnls of )Mitn.'<i<uim und 
Hodinni tjirtnife, KNh(\H/\ 4H,f l.f /*oArW/ r7 S^ttNl Tfirfntn, 
I .S.P, ), If mi: known as Horhriie S'tft, will be dojKjgitetl, The 
eryi*taltf tire large rhominc! prisnisL 

2KNfirjip + H,0 + CO, 

l*MiM>«'ttnn roiiu«.sJum uiu! Kmlhim Wiitcr rnrtionk* 

hilartriile tiirtnite imhytlrldc 



Nn ( (> f 2KnrH.o. 



& The jliimt^tf*AL — Dip the lcM>[>e<i end of a platinum wire 
into a solution of a p>tnAsiuni salt, and intri»rhu^ the l(M»p 
into the lower part of the llnme of n s«|drit-binip or Bmim^n 
burner. A light violet or lavender tint will lie eomniuni- 
ealed to (he Hume* an etfeet higldy elmructerlstie of galt£ of 
potas&<iuriK 




POTASSIUM, 



85 



Potaasiyiii h3i!U are n^t rt^Uilily volatile. P'lare a fnig- 
nient uf **arl>ouiite, iiitnite, or other [lutjussiiim j*iill, on a pux-e 
of [^Jatiimni foil, unil heal the latter in tlii* flanie of a lanijj; 
tint salt may fuse to a tniii^jmrent iiquid atnl (low over the 
foil ; water al*io, if prest-nt, will e^'ape as steam, and hiark 
carlKHi l>e set free, if the wilt lia|ipeii to he a tartrate, citrate, 
eU\; hut the jKJtnsisiuni eornjM>und iti^elf will not he vaj>orizeil 
lo any aj)j>reeial*le extent uyle^NS exjaistd to an exc<?eilingly 
high teDijierature. This w a valyalile negative proj)^rty» as 
will ^»e evident when the ainilytiftjtl reaetions of ainnjoniutn 
oome under notiee. 

6. A solution of i^ifcliyni eohsdtie nitrite ' if< a very delicate 

for potaaniuraj in the fdjsenee of aminoiiinni, pnta^Kinnj 

iiltfi lorining with it a yellow ]>reeii>itate of [lotasHnni colmltie 
nitrite ( Fii*eher*« eiiiltj, Kjt'o(>i(>j )^, even in extremely dilute 
sulutiuiis. 



QUKSTinNS AST) EXERriSES. 

Kiirae tlip ,Hrlurl'<^ nf |M»i)i<v4iuu». — (\\\'\- list- s<iinrt', formula, and rhiiniLv 
tcr* of l*otai*Kiijm C "arlMififltt*.— Wlt:it is \]w RystoinMitii" niiint' nf Caustn' 
i\»tHHh. Si4iti? tin- vlantiiiil ruriinila **{' TuukHc rohifili-^C'iinstnii't an 
|iiHli«tn rt'pre^^utiinf thr nnrtloii tn'tvvrtii fM^ta^^ituai airljunuO* nml 
iked linn**.— Dflhiii' n htfitrn.iiffr. Whjur ijt'oiip MfHtnu^s isclinnuifriKlii' 
^ all i!»irlMmatt-H?— lli»w is " SulpJinnittil INiUinh " miKlts and of whjit 
fit 1 1« is it fi mixtiirr'?— \Vh»( is thr furnmlit fm- thr ih Id niclirtil i>f nil 
•cetntrt?— Dniw a disijfram Mliowiii^^ tljt' lV»iTii»tii>n of IN^tUH^iiiin Aii*Oin\ 
-^Oiv« » itmrf-*^^ fi»r tlu' trmvt'isi*jfi of larlrioiiatt'S mUt utln r sjik?-. — What 
In th** dittVrt'nin' iKtw^iii I'ntaisHiuiii ^^cirlHumte and and Hirrirhotniti"? 
How i« l\m lattiT |^rp|ian'(i 'f What is the rL^lalimn bt'twt-rii »tiHs 
trlt<iw> fSf»rs'iiir; rninic'^^OHd in \\w mIIiiM*' "ri/*-."itnd lU'ids f>ndiy^ in'* >>,'*? 
— lonstniH diapminft or 4<|(mti*inH i-eitrt'wntin^ tin' fonnalion of IV 
laiwititri Tttrtnito fmm Acut Tartnitr. and IVphij^sinin < iimti' Iihiji Tar- 
hrifmttv— Distinguish between a nornial and an arid t^jilt. IhfW is l*<ftas 
iinin I^xtide mad*?— IHuHtnit* the ^irore.KH eithri by ilia>.^rnn^ ur I'unn- 
li«ifip^— r^lculatt' how niach potHwinrTi iodidi' is iirodnriMc frttm UMM* 
gniififi of ifidini'. .t««„ l^fKn gniins,- niw a nutbt^d lor tlu' tictrriioa 
«f i(ii1iif4r> in [K»U»J*.ii«m i<>didr. Exniain llic rt'sniiiai, -Wlial is tlir sijiniti- 
csititm i»f thf tvrruiuutfoii '*»Vff*' ni ilitwiiud niamiu bitnrc? Stuir the 
!> ! ' ' rwecn snl|>bidi'**, KftlfdiiN^H, und sylphaO's- MetOitai llie 

eh aifiii f*f l*ijtHs.siiuii Unanidf to Pi^tassinuj Iodide. — heM'HlM? 

tie "J of I'fttax-viuni rennanpomte. i^iving tMnnUionH or iliuuramn, 

-*H<iw do tiinnpHnut^^H m»l |K?iJiuinK»fiat#»« »et as »iisinfiH*tanfH?— Eioj- 
ute tlic tc»^tj<; ftir fifitaJiAimn, explaining hy diagmmi^ or equuti(aii> the 
ion6 which oiH^ur. 



f SfMiiiirn Othjillic N'ttrit^ TvRt Solatiini, U. S. P., is mtulG by diMiiilviiiir 
4 fim. of rolmltonii nitmtci and 10 Hm. of ^cHlium nitrite in ^^i (\r. of 
wmter. »(ldltig ^ C.c, of urctie arid and diluting with water to IWt (\c. 



86 




THE METALLIC RADICALS. 



SODIUM: Na. \unnw wei^lit, 22.B8 



Oevurrenct^ etc. — Moiit of the sodium siilLs (iiet witli iii phar- 
niacy are obUiiiieil <lirivtly tram sodium tjirlitJiiate, whifli is now 
iijSLiiuihLtUFrd on an rnnrninus urtdv irum wKlium chloride (mm- 
mon s«k, M'ii-siiltf Imy-Hidt, or nHdc-siilt), tlie most abmniant of 
the jurthnm sidt^. When pure t'omnion siilt {MSotUt Cfttffriiium^ 
U, 8. P,), oetiirh iiw :i while ery^tjdline jniwder or tnnir<|iarent cubic 
ery^tJiLs, free from nit>i.sturc: the W't^l varietie.s c<jmnioi)ly contain 
a little magnesium chhiride^ ariil stinietimeH other imjmritieM. 
Besides the direct and intlireL-t hh** in niedieine of sodium curlion- 
ate, or '*earbon:ile of noda "' as it ih eomnioidy culled, thiK sub- 
stunce i.M Im rarely ustnt fur Inaiscbold ek-ansing jiurjio^rs, under the 
iianie of ^'wanhiniic wotla/' ami in the manufacture of soap. 
Sf)dium rntrate als^i occurs in nature, but is valuable an a nitrale 
rather than as a sodium wdt. Sodium in the form of one or iither 
of ib^ (^oniponnds, is a constituent of about torty chemical or 
galenical prcpsiratiims of the Piiarmticojm?ia. 

vSodium is prc|>arcd by a process HJnular b> that for [»otiLssium, 
but at a somewhat lower temf>eratun\ t -iLstner obUiined it e<*m- 
paratively chcjiply by distil bition from a mixture of Mc^itium 
iiydroxide^ carlKju ttij<l irtm, contaimd in steel vcsscdi*. The 
modern Castner jjnH'css fi)r preparing siMliuiii, by which lar^e 
ijuantitics are now oitttiincil, consists in eleetrolyxinjr iVtscd soditim 
liydroxide. The inctal ha.'* a bright metallic lustre when tW-sIdy 
cut, but is rajadly attacked by utmuspheric i»xygen, mcdhture and 
ejirbniic anhydride, and eventually VicconieH coatetl with *mlium 
earliomite. Thrown upon the surface ni' water, sodium d»splae<*i4 
hydro^^cn from tlie water, yicbling soIutioTi of siwlium hydroxide; 
but uidess the sodium is eonlinrd lo ojie spot, by ]dacin^ it on a 
small iloMtin^ piece 4>f fdtcr-f>aper, the action is not sulhcii'ntly 
inteiisi' ti» cause ignition of the escaping hydrogen. When the 
latter docH ignite, it hums with a yellow Hame, due U* the prc?*- 
ence of a «niall ir|u:uiiity ofs<Mlium vapor. 

2Na ^ 2H,0 = H, ^ 2NaOH 

HoiliuiQ Water Hyi1r<»>;en Sorliioit hydroxU!« 

Sodium similarly att^iekfi aletjlnd, yielding sodium etbybte {^e 
Index), Tt may l>e kept benc:ilh the surface of mineral naphtba^ 
or in scaled tins* out of contact with air. It crystallizcii in oeta- 
hcdra. 

Sodium Hydroxide. Caustic Soda. 

The formation of s<dution «>f wHlinm hydroxide, or C4iu»tic soda, 
NaCJH, is ertecl*^! by a prtK-ess restMidding that empbiyeti for 
making srdution of |:K>ta;4sium liydroxidc, already do^crilnil 

-f VuHyiW, = 2Na<)ir 4^ CaHO, _ 



ftarUiim 
cfirtKJiiiite 



(*utcium 
hydroxide 



Sodium 
hydnixiae 



eATbotukte 



SODIUM. 



87 



The remarks mado c nncfrnin*^ the ireiuTal properties of tMjhjtion 
of |Mtti4KKium liyi|r*>xicli' it|jply Ui this ^iMiutiuji jils(^ 

111 the Cai*tiier phmlsm, wlikli in \u npenititm nn the maniifac- 
tuniig: ^ale, js<Mlium hydroxick' {Stdii Ifi/dfojtdum^ U. S. P.), is 
obUiitUHJ ik» a (innlikt of tlji* dtctrulysis i»f a Hi^liititm nf '^oiiiuiri 
chlorkk. The i-hlo.riuo simultini<M>usly liljerak-d at iKf aiKHif n» 
aruithtT proiiuet uttliw eleLtrulywis*, is uised in the iitajiutlicture of 
blt'iiebitig puwder (^rf p. 1 1*J}. 

The inleriMlioii nf f<ulphur and tiiMliuni earhoiuite at n iiigh 
t»'in[H*ratUfi' ref^tidik's thiit of s^ulphur and [»(itas.siuiii rariumiite; 
but »i8 the produrt is nut tmcti in niedicine tht^ experiment omy he 
oiuittecL It ia rneiilinwMl here to dmw attenticm to the general 
Feeetiihlane^.^ of the i*otiLH.siuni salts to tlio^e olsiMjjmii. 



SodimQ Acetate. 

Experimeiit 1, — A fid hmIjuhv earlnjiiate (in pywder or, bet- 
ter, ill fnigtuent^) to inome Tiitj<lenitely eoneent rated aeetic aeid 
iu an evH(K)rat!Ug-ba:siii lis hai|j;: as eflerve>;<'eiiee tKN-iirs, and 
tbeo boil uiY mme of the water. When tlie fluid in e<dd. 
crystals of sodium aeetiite, NaCjII/)^, t3H.,0 {Stffiii Affta»*. 
V. K P.), will be de|Mj.sited- A teti j>erceut. .s^diition in 
distilled water Ibrma "Sodium Acetate Test J>t.>lution/* IJ. S. P. 

S'nilom A teti c Si id f urn Water rarbonit' 

cttrbcjuate, acid Neotntc': unhydride 

f^tdium aeetiite effloresces (jtrf p. 90) in dry air, antl lof*(*ft all 
it^ water of eryHtalliwition wht-ii irently heate<i It withnti^ndH a 
t«^tuperature id' 270*" to 280° V\ {nhmi |:i2<' to KJ8^ C.) without 
d«'roraj>oHitioii, hut abovt- M(MI° F. (alwtut 1411*^ C,) il rapidly 
eha rn, I U e x ten ded forni u 1 a , i J^ C H ^, ( '^ K ) N a, S H ,( > . 

Sodium Bicarbonate. Sodium 'Efdiogen Carbonate. 

The ac^tioij of earlMadc anhy*lride and water on jvalium cnr- 
iMniute, Na/X>j,, r<^*emble« tbnt oti jxttussiuin tMirlM>nate» btit 
in carnetl out in a different niiinnt^r. The re^iult i« w»dinni 
bictirb«)rmte^ NatirO, (iSfxiii Blmrhtnta^ U, 8, P. ), 

XaPO, 4 H/) 4 V(\ = 2NaHCO, 

MkrtMiimie iiti)^y(lride bicarboniilti 

Experiment 2. — If rut erystnl^std'jsodium carboimte, NaCO,, 
^0H,() ( wnshinn' smla), iu a i>oretdaiu erueible until no more 
\m eHea|»e**. Hub the procliu't, in a mortar, with two-thirds 
*it« weight of the same cry^lalli/ed wit whieh has Uiit been 
ilepriv€*d of its water, aitil plarv the powder in a te*»t'tul>e or 



88 



THE METALLIC RADICALS. 



lt>. 



Fri*panition of sodltim l< 



gmall Iwittle into wKirlr carlmnie anhy«tri<le may Im* ei>nveve<l 
by a iuUe pusaiiitr llucni^^li ji <Hirk innl t('iii^iiiutiii«: ut tlie 
buttcjiu of tl»e vessiel. To jrenenitt^ llrt- fiirlumir juihydrulp, till 
a It^-it-tulK* haviD^r Ji siiiiall liuk- iii iht; hot lam (i*r u [litne i^f 
wiilt^ irlu.«.s tulnll^^ the lower end of wbieli i» jilu^r^tHl by a 
gnjoved vurk ), with fnigjiieiit< tif mar hie, insert a eork and 
delivery-lubts and eoniiect the latter, l>y means of a piece of 

[ndia-riibber tiihtn^s witb the 
lube leadin^f into tbe ves,^! 
f^ontabiinir the Fodium ciirUm- 
ate. Now jdnn^'-e the tulie 
whieh eon tain** the marble 
into a tesst-glasH, ortptlier vesseb 
eonlainin^ a mixture of one 
\)nn of hydrorhlorie aeid an<l 
two partf! of water, and loosen 
the eurk of the Hidinm carbon- 
ate tube until earbonk* anhy- 
dride» Lrenerated from the mar- 
ble, may be coiisiclerrd to have displaced alt tbe air of this* 
tube: then replaec tbe cork tiji^btly and ^el the ajiparatUH a.side. 
As the *?n.« in ubHorhed by the Hnbum carlHMUite, hydrm'hhiric 
acid rmes into the tube <ont:iinin^' the marlde, and irenerates 
fre>ih jras, wfiicli, in \is turn, drives^ liaek the acid H<|yid, and 
thusi prevent.'^A the pnvcluetion of any more ^m until further 
absorption has t>ecurred. When the i^alt is wholly converted 
into biearliouate, NaHfO^, it will be ftnind to have iKHxune 
damp tlirouLrh the libemtion of some water from the oryrilal- 
lized carbonate, Na,('< \^ HUIJ ). { It would he inconveniently 
m«iist, even j«iemi-iiui<b if a [lart of tbe carlN»nate bad not pre- 
viously been renderetl anhydrous/) (hi the biree !S<*ale. the 
resnltin^i' iHcarbonatc nmy Iw* fried from any carbonate or 
traces of other sal(8, by uddirvir fudf il8 Imlk of cold distilled 
water, setting asifle for about half an hour* sbakinjr tjceasicm- 
ally, draining the undiK*«tdved (wirthm, ami drying it by ex- 
posure to the air on tt Iter- pa pen 

Thii* arrangt^ment of ujqmnitus for the preparation f>f s^Klium 
bicarlKonate may be adfipte«i for iKjtawRiinn hicarlMinatc, on<^ part 
of potasMiiini rjirh(aint4' disHolvtfl in two and a half parts of water 
being i*uhjccted to tlir jietion of tlie gfun, and not the stilid carbon- 
ate, as in the case ol'the wHliuiri salt* 

The wwlium cartMaiate may l»e placed not in u te^t-tnbc or 
brittle, but in a vertical tube, the btittom of which is hiosi*ly closa-d 



SODIUM, 



89 



by H ^movecJ cork. Any wjiler of rrystiillizjifiKU ilmt U '^^i I'ree 
thvti runs *ifl' ititu ji vi>wt'l tbnt in [ilsiteij iH^rirrith, and taki's with it 
TiiipuriOt^ (rliUjri<li*;4, sul|>tiitk's, i'U',), tkiil niiiy have been present 
ill the ongiuui rvuU. 

The Ammonia Ptoccm, 

BtKliiini l*imrbf>nat4? i** now preparefi on the manuftictiirin^ scale 
by treiitinjr ii eoiU'entriittMl sohiliiHi <>t' HxJiinn rhloride, xvhieli hiu* 
hci'U HjituniU'd wiih jinnnoniii, wilii riirlntnie anhydride under a 

{iivwure fwunewhiit |.'roaU'r thiui lluit nf the !itinos|ihen.\ Sodium 
Hcjirbonatt\ wln'rh is s|»aringly noluhle^ !.>i sh^wly preei|it(aled. 
Tbo am nil una and I be earbmiic aidiydriije may be t'i»iiriid*Ted 
U) beh:tve in the reaetieui a,H ammonium l>iearb(>natt\ 



NHjiro, 


1 Xat'l = 


=r NalltM), 


f NH.OI 


Amniotiliiiu 


Sfjdluni 


Socliuiii 


Ainimoiium 


til<TiirtHmiit« 


oblurlUe 


bieurtKiuutc 


ejjloridc 



Ainiuonia i'* recoveriHl Jr<iiii the ri^sultirrir ammonium ehloride 
atifi if> ii^ititi u.sed for !^itnn«tin^ sidutlon ot stMhuiu ebh^ride whieh 
U to be rm[»1oyed In fiiib^e^nrat o|»t'rat>ons for jire]Kirin|j^ tiirUier 
ciUHntitit^ofHodium hiearhonat*". Washing-soda, Xa.^rt K UiHj)^ 
i» tn^idi* by heating the Inearboaale thus i»f>tained. and rrystal- 
Uzing from a^uetms s<»lutiou, the larliuiiir anhydndi' liberaled 
(luriJi^ the heating proresn In irjjkf alsti iilili/i'i| in tlir prt*parati«iii 
of further ♦|inmtitit»-s of niilinm hicurhon:it4\ 

2NaHC<), = NaJMJ, -\- Up ^ TO, 

KiMHuin StMliiiiii Wnttr tiirlMulir 

birarUiiiatc i^ArbuiiHtc iiiihyilndc? 

Sciclium bifiirhotiate nmy be tJitsiidnaily adndiiiHtrriHl in the 
fonii of Io2cngo (Trochirtiit *Sbf/ii BietirhmitifiM^ IT. 8. 1\), 

Sodium Oarl}OEate. 

Hociiiim ojirlxnutte may i»r i*btaim"d by beatiiifr *he H>Kliiiin 
hiearbonate pHxiiieed by the anniionia prcK-eHM lU'mrihi'd above, 
the ri"*<ultin|^ salt iH-ing anlivilrons, 

SiMhum eiirlMiiiate is a!so |irepan^ on the hirg(* H^\e by the 
Lebhiue pr*MH*m SiHlium ehloridi* is fir^t ecnivert*.Mi into huI- 
phiite (ftiilt-niko) by beating' it with sulphurie aeid :— 

2Na('l 1 II^SO^ = Na,S<\ i- 2lfCI 

The sulphiit*' t^ theti rrmntetl with the lime**t/me and small eoal, 
^podium e«rbonat<? and cahnuiii snipbide bein^r (bnned: 

Tbr rc^ultiri^' imtm (hhirk-itsh) U lixiviated, {LiJ-ina, from /h^, 
lyr— wiiler iinpretrnut4»d with alkaline sjdts; bonee Ihivh/inn, the 
O|fenilion of waj^lung a mixture with a view to dtM4!*jIve out wduble 
eoiuititiionu. it relatively »nm\\ i|unntities* of nolvenlA Iw ei«- 



90 



tup: metallic ladwms. 



pli»y*Hl, ilit^ Htihitioii hy lixiviiiliim will In' iikhv iir le»i^ fnietiotttt/^ 
*iulMUiJicos of vuryinif suliiliility Ueiiiir thuft mure or lesti KepjinUt-d 
JToni i'iidi iitluT. ) Tlu- sodium airbnrifil*' (Ji?i.M)lves, the LJikiuiu 
Piil|iliide r(Mi\:iining insoltible. Tbi* .solutii^u is ev'u[H>nitvil to dry- 
neaa, and yit^lds iTiide HfKjiuru rarhoimtf. TIuh in roiLnU'd with a 
sniuU rjuiintily idnjiwdnst, to recrHivert into rurlw^tuite tiny t'liustic 
Bodii pnuhited by the iictioii »»f Hint* un i\w t^nUuni vnrlxmaie. 
Till' phMhu't i?^ mii*i-a/ih. lyis^Axvd in wnU't and vrysUiUhvd, it 
eojiKiitnU's urdiuary ** wsu^ldtiLi-s^Klit": rtxTvstjdlized (and whim- 
timt's gnmnd) it tnrrn.sjniritk'd smhuni riirboiisLtt% Nji^CO^, UMIji). 

In thi" Hiirgreaveii-Binl tleetnilytic iProiVE*H tor the nmnn- 
Ikrtnre ot' Ht^diuiii carl»f>nalL% tlio rt<Kiiuni hydroxidf; »ibUiiiiLMl by 
the eleetrolysi-H of a sulution of sodium ehloride is treated with a 
mixture of steam and furnace piS4%s (tlu- hiUiT furnishing; rarlmrue 
anliydride), whendiy a wdulion is oiilaim-tl whirh only r«'t|uirc*H 
eva|joration to a snnill extent itj ordtT to yield erystals id* Moriium 
CftrlKHiate on eiw^liiig. 

A en/xftii (»f deeahyilratnl HoOium carbonate i^ wMlinm earbonate 
plu^ *' water of t'ryHtaliiziit ion "; on heating it, ]»artor(al HM^'^C), 
the whole o( the vvat^vr isevtdved. The KiKliuin earlmnatr of the 
PhaniuR-ojio'ia is the inonoliydrat^^l fc«alt,, NayCO^, II^U {Stuiii 
(\tf'ijOii*M Mtmt*hijt(riitu*^ U. S. P.). The deeahydrateil sjilt h^si^s 
iiine-t4^*nthH tif it.s water at about I^'*^ t\, leaving the moioihydrated 
Bait. Tho ottiehd sjdt is the latter hi the fornj of a en'stalbne 
(j^rannlar jniwder, whieh in Heiinely atfeeted l>y ex|K»8ure to air 
undi*r ordinary eonditions. 

fiorrHnmrt'. Anhydridn^. — X jitnnber uf Halt>4» when erysUilllzing 
ffinii atiueous solution, lake up water to a frreater or les*^ t* xtt-nt 
from \\u' sohitiiOK S«»nietiim'S the same ^^dX is fiijiahlr of eom* 
hinini^ with wat^T in twfj or more dilliTrnL i»ri4nirtir>ns» Saltn 
whieh do not eombine with water in this way are rjfli*n c^llc*«l 
fttihydn/iijt [from a, o, witlioiit, and mp^i, liudf>i\ wnX^'t) a*< ili^- 
tin^ruii^htHt from those whieh do, and are, in ronseAjuem'e, ealJetl 
/tt/drouji salt^, Thf wattT s<i taken up hy eertiiin siilts in ery«t;il- 
lixinj; iH generally ealled wnfer of rrt/Mfn/fhitfinn, Many hyilrous 
m\t*, when Hinijily expos4'd to moileral-ely dr>' air at f»rdjnar>' tt^in- 
|M}rature8, lone water and eruriible to a fine jMnvder. This pro- 
et'HN is known n^ ejfort'jtfenrt' {e^artMrrtJt, hlosH4ii(iirijj forth, in al- 
lusion to the npjtearanei' rd' the priMluet). The watt*r of erystal- 
li/ation is usually (jdthon^di not in all eas4*s emtipletely) ex(»elled 
from a hy*lrous sub by heiitiiig it to a tern pe rat un* of \mi° to 
I5t)® {\ In thi* ehi^mieul Ibrniuhc of .salts with wat4*r of erystab 
lization« the synd>ids repnvs^'^titing water are usually si'parat4Ml 
by a eomuia, or, as In the U.S. P. ,hy the f si^jn, froni those 
reprew'utin^ Ihf m\U^> The erystjils of wwlitjin aeetale (Kxperi* 
tuent 1, p, 87 ( are represented by the fonnula NaO^H^O^, MH^O, 
and tlii**e of deeahydrat^^d 8u<liuin earlKjuaU^ by the Inrmuta 



soinrM. 



91 



Ni^CO^, lOH^O. It is pnsHiiilt'. liowrvtT, tluit thif* sm-i:i11<-i1 wijtvr 
t}( vryntii\\izAt\on '\h in :i iiii»ri' iJitiiiiiik' Hlato u1 eiiiiil»iimtjnjt ttmii is 
iiiflintU'fl liy Hiich rnnjiiihi' ius tlmsr jur^l ^ivi'ii. .t«A//Jr/Jrj* Inrui 
A liistirK't diisA nf fhi'iiiicjil ^ul>stjiin es (ltTivi*<l from <»r rolntt'd h> 
a<.'iUs ; in Hhort, tlit'.v muy Ite, rvyi^iknlvi] as arids iVuiu whirli the 
elemeDt*^of wuti r haw breii removed, th<' e^Heiitiiil rbi'tuical proper- 
tit's of the tmUln bcin^ tlitrfby gnnitly ult4*red. 

lhiiifHtMrrnrt\ — SiMliiitii I'aHioiiatr aBi! [MitiusHiuni ciirlM*iiate, 
ilu»init!nlly rloH4*ly jiHifHl, fliM'er pbyf^iially. I*<iti(K<ium carbuimte 
i|iiickly iibaorlirt mfjihture from tbe Jiir iintl bt'runH**^ tlamf*, wi't, 
aiiil tinally a fi«»luiifni — it in ^irfitpttxctttt {firliifHts^vfftn, molting 
awny). Di'Ciiljy<lrat<'<l >«><liiiiu carboiiutts on i\w otbor hand^ is 
eM*irfSceDt, sijul yitdds water uf rrystallizittion in tbr air, tlie 
cr^t^tab becoming wEite, opatiuo, and pulvernlent. 

Boditim HypocMorite. 

Hxperlmeiit 3. — Trirnrato in a rnotjir 2 fJirt^ nt' cbloriiiatcd 
lime vvitli ii f^ihitbni uf 1.^) piirtw of imjunliyd rated nidinm rur- 
lw>nate in 20 of water, ami filter. 

[Ch(CIO) -V CttCy -h 2Xa C0,= 2[NaaO 4 NaOI] 4 2C?aOO, 

Chlonnnic-d 8«Mlitim riilfirinjiled nilHum 

Kjuc citrhciiiate mnhk enrboriAte 

This wdutifjii is an old and very us<etiil disinfeetant, fc*rmerly 
known at* Jjibfirraqur- ^f Wqtwr atui JCau de Javefir. It eontaitw 
aVtoiit 2j jH»reent, of avaible idilorine. 

Tbo ollii'ial iAqnor SoiUr (■hhrimihf is prepared in a somewliat 
analo^UB manner, but witb eert^iiri ailditi<»nal detiiiU. It slionld 
i^imtain at bust 2.4 |M'rrvnL of jivaibibb- eblonne. 

Sodium Iodide and Bodium Bromide. 

The^ ^ilts Nal aJid Xalir {>»Klti Lhlitittm, IJ. S> P., nnd MSfniii 
lirutmdutH, I', 8. r,), art' analogous in eonipoKition witb potassintn 
kniidt* and brnnjtdi\ and ' iire prepared by a Hiruibir aulljod, 

linm bydroxide ]»enijf and iu pbue of jiotiixHinm bydroxide. 
[imu liromide, bowever, innwt be ervsbillize*] from warm wobi- 
ti*»rM, otherwiw*, rliombie pris^mH containing water, NaBr,2IIy(X 
will l>e depf»«itod. 



Other Sodium Compoimds* 

Expenment"* deabnjc wit!i Uh* rbruiistry of tbe remaining im- 
(Kirtant j^Mlinm rom)KajmU (njnm'ly, iiitr^itr, snlpfiate, lliioj^ul* 
pbitk% JMirate, arsenate, valerianate, and I'tbylati') are diferrt'd for 
the pref»ent. 

Sifditim Phfmphatf^ — Tbi' preparation and eoni position ui thi** 
m\t will be niOHt ii»efidly studied aftt-r bone-anb biu< been 




If2 



THE METALLIC RADICALS, 



tk*?*iTibr"l. Btiiit'-iish y iiupure talritmi [>hosjilmt^ nml is the 
Ktiirtin^'^ point for tbt- jirq>arutiiMi of ii^osl other phosphjiU'K ami 
for phij?^]<horus jlst*lf, 

iS!(tfiit PhiNtphnii Ej)\rvt'^ftiJ^^ U. 8. I\, iM iiinrit* l>v mixing the 
ttnhijdmug [^hort^^hute {S>*{ii Phmphnj^ ICrHirmfntt U. iS. P, ), with 
Hoilitirn liiciirhoimte Mini tartmic anil citric jicidH. 

SitfUftfii ptrfi,rith\ Nh„(>.^, it ninipound now ninuufiietureJ *m 
II lar«ri* s('ak% U ns4'd ji>4 a bleiifhiiig ago J it, ami in rheniinil 
aiiiilysi.s jtH an oxi'lizin^r a^ent. 

Aittihyitjf of ,S()f fi urn <i/nl PntaMtnm mtffn. — Otlier reai'tioim 
t^iniihtr to tho:*e jrivi'ii lunler ]nita,H.<imii nit|r]it ]ie meiititnu'*! 
heri%ari(| the |»rei>jrri*tif»n of ^Kiciinin cilrate, (-Vw/iV (^ifrm, V. S. P.), 
iodatej brouuite, rhlorate, {Sfnlii Viilmui^ W S. P.), nimi|?anate, 
[ternianniiniite, aiul many other H;ilt*< be UeserilHHL Ihit enoii^h 
lian hc-en stated tu jshnw how s«KUimi is elnL*niieally aiialo^oaw to 
pota^wiiiin. Sueh aunlojiritw will fre^nently |ireHent theinselve!*. 

Sufin'ififufioit i>f Pofrt^t/m fTHfl StifiitfM fttdh ffi.' rarft ofitrr, — - 
8»nliuni ^alt« Ix'ine eheaiier th;ui |Kitijs.Hinin salts, th<" former may 
!*oineti(new lie eeononiieally s!il>Htitiite(b That "^nie i^ eiii[»liryed 
rather than the other, is otteii merely a rennlt due to aeeident or 
fashion. Hut it nm^t iie Imrne in nniid tliat in simie easi'S a 
potasMUin salt eryHtallizes more readily than its sodinni nnalopir, 
or that a j^oiliniti sjilt is nro liatiifeil hy exposnre to the air when 
the eorre:^ponfliu^ pittassiuni salt lou* a t^Tnletiey to absorb moist- 
ure; or oae may be mine .Hohihh" than the other, or the iwo inay 
liave rhIltTent meiheiiial elfeets. For lhe.*<f or similar reasons, h 
[H»ta.H.sinm sjtlt has eouie U> he n?«'ti in tnerlirine or ti-ade instj(?a(l 
of the eorrt^fiomiini^ soilhiai siilt^ aiul r/^v /r/wl, WhriJ a -*^alt i« 
eniphpyetl as a snuree of a pnrtienlar aeid radieah the least exjK*n»ive 
tmli of that radical in nearlv alwavn seleeteil. 



I 



Arin/f/ficfiJ RftwiintiM of Stulhtm SalU, 

1. Thr rhief atiiifi^timl reai^f ton a f^yr siKliiirn is (heflame^e/^-. 
Wlieii brotiirht Into coiilacl with a BytiJ*en flame in the manner 
(Jesitanbed under jiotitse^inm (jia^e ^4 ), an inten,'i4dy yellow eolor 
is couiuuiiiieHltMl to the Ihune by any j^odinm 8Jth. This is 
Ki^hly charaeieri^tk*^ — indeed, almost too delieate a test; for if 
the end of the wire he tonebeil hy the linirerw, enr*u^di sodiun) 
m\l (whieh in naitnined iti the moisture oi*tbe liand ) adherei* 
to the wire to cianmniiieate ti very diHtiuct SfHlinm rea<^^tit»n to 
the Manu\ TlieH^' statements shoyhl be exjjenmentally vej'i- 
Htnl, jaodhim t^hloride, .•^tilpliale, or otlier mlt liein^ employed. 

2, SiHliiim snlli?, like thost^ of pila^isiunu are not voIaliU*. 
Prove this ihrt by tlie means des«eril>ed where the eft'ect of 
bent on potaasjum stilt i» reterr<?d to (p. 85 J. 




AMMONIUM, 



93 



QUESTIONS AND EXERCISES. 

Ejt|)laia the action of •vtjiliiiTii on waUrr. Wlmt ci^nrs do H4>diiim and 
iKita-'ijMini roKjHH'tivrly finiiiniifiirjit*' to Aunie ?— Hirtiiom atetate : give 
hirtuuhk uiul preiiAnttiiiii, with iqiiHtiuu.— <iivt' a diuKnini hliowiiiij thu 
rormttlian <dS<Klinui Bicurbonutc- Why if< u mixture at' dried and itn- 
driid schliinn i^arbinniU' tniphpyi'd in iliv [»rL-|ianirion uftlie hicKrWiuitti'/^ — 
Suiti^ the ditTiToni'i" iH'twutMi utthydrinif^ anil iTy?>tallized wKliuni nirbtiti- 
ali\ — Lhjtine tlir U'^rmtynuhf/ifntHn/h/firouM, utthpilritte. — Whut dnyuu under* 
KUnd by irairr o/ cntMUtiHzntion /— Wbiit is Uie systi-'TOiitit" naiuu of 
Urn lid le Salt, imd how is the «ilt pwjum :d ? — Whut in the leLition of 
Kmhi'lk'^ Sdit III crt^amaf tartur lind larl^arir acid? Uive the nn-Hleof 
pn'(MrAtf»n of ihe oflirial Holutiou of ('hh>rinnted Soda, rt|in'»«.'ntin« tho 
uroeesis by a diai^ruiiK — i}e^uv. ilrfitjiie^eftK't', rjEWwre/rcfwrr, itnd /i.cinHiiCtcfK. — 
Utiw are sodium salte distinguinhetl fmni Uumi of poUmaiuiu i 



AMMONIUM, 

Radical of the unmiuiiiiuii roinpmiitK NH^. 
The eleiiiftus nitn*^*:*^'!! ainl liy<h(*i::t'», in the |»ro)Mirtifm of 
oi»e atoiu of the fumier N> four of I he ltitter,(\NH^ ), itrt^ prt^fsent 
in all the tiniiiiiniitHii eoin|icnjiii]s iihoiit to l\e studieih phiyiii|i^ 
the part of niettillu* nulieal jtmt iij< |>otaRHiuiii ( K) ami «o(iiijtii 
(Na) do 111 the [xitasf^iuni ttiirl Hodiiiiii eoiii)x>mid8. The grou[> 
XH^ h univalent like jMitaHSHitii ami sodium, aud the arn* 
inoniuin coTii|M>niid!^ ("hisi^ly resetnble thos«e of |M)(n,Msiiini arid 
NxiiiitTL Amiiioniiini is naid to have Ijeen i>M>lated hy Weyh 
Asan iin.Htiilde dark-hlue liquid }>os8es8ln^ a metallic luntre. 

Source, — The i^oiiree of rieitrly all the aamionimn kjiIU met 
with in eoimnerce it* the atnnntnia iraA, NH,,, ]>nHltienl duritip 
the <li«tilhition id' all kiiulH <if i^nil in the inaimliirtiire of iinlinary 
itluniiniilin^ pin an*l iif viikt\ Thif^ aiMiii^iiiia is m» dnidd derived 
friirii thr nitro^ren of the [dsitits from whieh the eoiil has Imvh 
jtriKhieeil. It Im cddiiined je* it Ity-prorhn t in die distilhdinn uf 
s^hidr for the prmlurtioti nf imratfiti oil, ioid is iiIh^i reefiveml from 
thi' fiirniM'i* pu»«'H of in 111 -works. It is |H»ssihh% h*>wever, to |ii'o- 
duee aininoiiia tVfjtn its eh.'nii*nt.s. Thus wht-n electrir s[mrks are 
piii<s4Ml through Ji ndxtiire of nitrojxen aad hydrogen, or when a 
similar ndxturr im |i;«Hsrd over wpon^ry [datrnnin, :-«ime iiinnit»nij| in 
pnKhieed. Aerordin^ t^» Rieknurn tind Thont|«s4>n, eon!-<kiKt, air 
rttid v«|>or of water, all at a red heat, yield ammonia. Salt ad<led 
to thi' nnxtnri' jirevent^ tin- eondni.stion of aniuionia fornoil, luid 
aiiKtionitnn iddoride Hnhlinirn. 

Ammonium Vlifaritie, — The nnnurinia lilwrated from the **aiiiino' 
ni.'U'^d lk|ni»r" id' die ^as- works hy heat m\A hy the ronrnirrnt 
Hiiion (»f shik<'ij lirnr on tin' nnniioniniu liydroj^ttl)diid«\ earhf»ti- 
ate, and other salts |jrej$ent, when piuwtMl into hydroi^hltirie aeid, 




94 



THE METALLIC MADWALS, 



yieldn cmcle amfrnjuium c/iiori*!*' (salaninujiiiac), NHg + CHI 
= NHt<'l; and from this jsult, |mrifitHl, tln' cvtlii^rs us^ed in phiir- 
nmcy «ri' iliret'tiy or indirectly mink\ Anuuoniuiii Chhiride 
(Ammonil ('hhridnm^ U* y. P*), oi:furi* in folorless iuodiiroUK 
jiiinute rrystiilj^, or in transkir+^iit filin»iiH niiuwt'**, tt>ij|rh iiiid dilli- 
i'ult Ui piiwdtT, K«jluble hj watrr and in alfohol <!"> itertTUt. ). 

( V)iiiint ri'iiil Mnininjiiiiiii flilt>ridt' generally ecmUdns ?ili|rht Iraees 
ot' in in tixyehli*riile, tsirry nintter, and poKsildy compound aui- 
njoniirni t lilciriden (/i** ^'Arliticial Alkaloidj*'' in Index). 

Amimmhoti Stifphafr, (N II^)./^( >^, is formed wiien the amirinnirt 
of the annnuniaeal liqu<»r in nentraliztHl with sul|diuric aeid. It 
i« largely nwd sus a eonxtittient nf artitleial niiuiure; and when 
piiritied l>y rerryHtallization^ [^ em[*loyed in pharmaey for |«ro- 
diieing the double animonkuii and ferrie sulphate (ir(*n alun»), 

Vftfrnaif Amttmuiii,—A very pure (brni <*f ajnmonia is that met 
with in voleanic district!*, and obtained n» a by-product in the 
ntanufactnre of borax, Urude boric acid as imported eontainw r> 
to 10 |>erceiit. of anuuifuium salts, either sul[diati- or that salt 
united with inagnesiuin, sodiuiu, or mangamfse sulphates, f*»rnjing 
BO-callod dimbk mils [Howard). 

Ammonium Amalgam. 

Experimeat 1, — To forty or fitly ^niins of mercury in a 
drij teM-tiibe, mid one or two small jdeees of siHliiim (free<J 
troiuadbenui: im})hllm by gentle pressure with a \necv of tiller* 
pii|«'r ), uu4 gently svarm ibe IuIh?^ when the metals will unite 
with cvtdiitiou of heal to fornr Hnliam iiunttgJiiiL To tbis 
nmalganv, w ben cold, lubl some fragment;^ i>f amini»uitiru cldi> 
rirlc {Hill a eoiicenti*ute<l fwdutioii td' the siitne s^alt, Tbe 
s*jdiitm amulgmn rtipiiily swells tip iumI tnay even overflow 
the tiibe» The light spuigy mass pnidiieed is the so-enlled 
iinimodiuni amalgam, ami the ivrtciimi is usual ly adduced us 
evidence of tbe existenre of amniouiym* The siKlium of the 
amalgam unites with the chlorine of the tunmoniuui chloride, 
while tbt* aiutnoniuiii is" su|*|M»sc(l to tbrm tin amalgam with 
the mercury. At ordinary tei»j»enitures tbe amalgjim rapidly 
gives off hydrogen ami anuiiouia tpiik^s; (bis deconi|)osition is 
nenrly eomp!ete tifter some mitiutes, tunl fiiercury reniains, 
together with the scdurion of *«o<liuna chloride. 

Ammonia Water. Ammonium Hydroxide, 

Experiment 2. — Heat a few grains of amnionium ehloride 
with alK»ut au e<|ual weigbt of cjilciuni hydroxide ( slaked iiiiie) 
moistened with a little water in a test-tulie ; amraonia ggii is 



I 




AMMONIUM, 



95 



giver* nflf, and luay be recognized by its puogent odor. It is 
very s^olulile in vvatar. By rneaua of a c*t)rk tmd deli^^ery- 
tulx?, fittetl as descTil>ed for the pre pa ration of tjxygen and uf 
hy*lro^en» pii^e? s^nne of iiw amnionic into anotlier test-Uilw:' 
OL>nt;uniiig a little water. The end of the delivery-lube .nhouhl 
only juiist dip bt^uciith the .surtuee uf the water (or possihly, all 
the wuter mi|^hi ru.sh buck into the generating tube, on ae- 
eount of t lie water greedily absorbing the ammonia gas). A 
solutiou of ammonia will thus be formed* 

2NH,U1 f Cii(UlI), - CaCl, T aH,0 f 2NH3 
jlmiiioniiiin rulcluiii rnklum Water AiumoniA 

ch1<irule IiyilfuicEilu ehUiri<l« 

A oioleeule of ammonia m composed ofone atom of nitmgeii 
with three atr*in« of hyilrogen; its foniiiihi is NH^. Two volumes 
of tbc gas ofiiitain one vohiuie of oilrogrn cinuhineil with three 
voJumct* of hydrogen. ItiS i:oiiHtitueiitf^ hnvi-, therefore, in eijui- 
hining suffered eiin^leiii^ution t*i one-half of their ijrijriusil hulk. 

The *)lwtion obtainrd hy dissolving iunmoniii in water i?i lielieved 
to eontiiin iimiuoiiium liydroxide, NH/HI, the umilogue of poOis- 
ftium hydrtixirJe, KOH^ or sodium hydmxide, NaOlL Theehemieal 
grfjutidi* for this belief are the observed iinaloi^it*^ of the well-krumn 
ammonium f4iilt8 with those of pfitassjum and seHliuui, the similHrity 
of action of »»olutioaH of eaustie potii^ih, eau.stic ><od!i, and auimcuiiii 
on Hiilts of mi»rft metals, and the iLsserted existeuee cd* crystals of 
iin juialoKOUs !aul[diur sjtlt (N 1 I^SH). Tlie formati<m of amaionium 
hydroxide may he illustrated hy the following CMpiutiou: — 



•cale 



\H, 


f 


np 


^ 


NH,r>ii 


mmonla 




Wftt«*r 




Airmioiiluin 



im^i 



Sniution^ of Ammotnn^ prepared hy the alKiro pnx'efw on a large 
lie and in wuitjible aj>i»!imtU8 (bottles bein^ so «rrnn^erl in a series 
I to eoritlense all the ammonia evolved during the ojperatioa), are 
in pharma4\v — the ntie (s[i, gr. t^}<l>7)eonti»iniii^ 2S pereent*, 
the <>ther (sp. gr. 0.1)r>8) 10 pt*reent, by weitjht of ammonia^ ^'Wj 
\A*^*ia AmmimUr Fartinr and Aqnti Ammonitt\ V, *S, P. One part^ 
hy mrtimrr^ of the ffimier, ami two rvi water are mixed in order t»> 
obtain tb<^ latter), 

SpirUiu Ammonia\ U. 8. P,» in alcohol {f>2,3 percent,), contain* 
ing 10 |)ereerit, by weight of ammonia, XH,. 



Ammoniiiin Acetate. 

Expenment 3, —To fliluted aeetie neid in a test-tube add 
eormnereial arnmoninm earininate until efferve&eenee een*se*, 
Mid the lt<piid, after well stirring or shakitig* or ^lerhaps 



96 



THE METALLIC RADICALS. 



wiirmiri^, to get nd of earboiiie auhydride, i^ only faiutly ftcid 
to litmU'H (Kf'rt |i, ild). This solution^ wheti of jirestTilied 
stiviJtj^th, fornis the oHicirtl iSjlutiori of Ariuuonium Acetiily, 
N 1 1 ^( '^ H^(J.j ( Li y Hot' A m Hi fPt$ il Ai'thiti^, U . S, P. ) , On 
eviipomtiiig mid cuoIihij:* aniiinmiuiii jiivtate tuny be ohtiiiiiud 
ill <_'rv«tiils, hut scmii' oi'flu' suit will theti Imve uodtTpme dii- 
tx)iiijX)!s]ti(»n into aninionlEi inu] aivtii' acuL iu the raiv cnj<e 
of exmi ninjtnility lifitig re^iuirtMK to tbu liijuid vvhi<^h ha.s 
heeii made slightly alkaiiuu with vxvrm of uriiuioiiiiiio carhju- 
ate add aeetk^ a^id, tiually drop hy drop, utJtd a drop of the 
rn-^ulting jJ^ilutioD mt loiigcr trives a white [irec-ijatate with a 
drop of a clear solution of onHuary lead aeetate (ou a piece 
of ghi>s hacked by hhi*'k paper or lilark elolhj. 




N1I,HC( )„ Ml^N 1 \S:\\ i' 2H]C,f l,t *,- 

AiiiiiHiiiiiiiii) rtrid enrtn.iiiiitc At't'lit.' 



Aitimoiiiuiii Wiiter Cart>imlc 



8ulutii)U of amnictniaai loetjilv mo, of rnunHe, als<^ hi' nnuh' by 
the Intcntttioa of aet-tit' aeiii toul aiouioiiiu water; but the liquid, 
ciwiiig to the absence of dissolved carbouie avid, ia loo vapid for 
laedieiu^l uj*e, 

AmMOEium Carbonates. 

. (hmmermal ftmnmnium c^irhonair in maiie hy heating' a nijxture 
of ealriuni eurh<»nnte and anininrilnrn ehhiri^ie; eah iuin ehloriile, 
t'at'L rentaios, while water, 11,0, and some aaouonia, NH^, 
e.HeajM% an<j the anmieniaral earlM»nate ilii^tils or, rather suhlimeM ^ 
m eaki*s {Ammnnii Ctfrhonm^ W ^ W), The be.*«t frtrm of apjiaratiiH 
to einplo)' in a retort with a ^hort wide netk and a ecK)! reeeiver, 
t>n the large stale tlie retort \» usually iron, ami the reeeiver 
earthenware iirgliiHH: on the r^miill seale ghi^tH vessels are employed. 
The salt i?* [uintiett t^v resuhlimalioii at a h»w^ teuiperature — 
L'VO" F. (65.5^ V.) is Hiii.l to \w sufficient. 

The siUt, the ein|iirieal fonnuhi of which is N^H^,^,?^. is prob- 
ably a mixture r»f one moleiide (sometimes two) of aamioniuin 
hyiiropoi earbnuate (aiiimoninm bicarlMHmte), XH^HOO^, nmX 
ojie ni a siilt termed ammonium earbamate, NH^NH.OO.., The 
latter helt»n;r^ t<> an inqmrtaiit rlass ol" smIIs kunwii as r<rr^/«m/r^, 
but is the only one of flirt»rt Interest to the phiirnuo'ist. Cold 
water extraets it from eoinno^reial amimminm earlwuiate, leaving 
tlie greater part of the hiciirbonale undissolved if the amount of 

' SHblimntimt (fmiii ttnhlmh, hi^h) ia Ibe li»rni ii|»pHeil to the evnpnriwi- 
tioti of II t^Anl Hiilwrnntt; by lieut, jokI its i!iiitMei|tirjiit ctriiilctisjiriim on iin 
iip|kT unit foolrr |inrt of tho veaml *it apimnitijs iu whkli thf o]H*miitiii 
is fK'rfiintiiML Tlir priKltii't of isuldnniitioii t.-s niUi>f1 si MuMiMntr. Tiif- 
f»*r«nit Hiitjslimres Mit)|itiir iit ditfrr^'iit t^mpi-mtiire^, Uviuv n iiiixtnn' of 
volAtile soliiU iiuiy sometimes be s«qi4t ml ihI or fnictioniit^'tl by RUhluimliciD. 



I 
I 

I 

I 

4 




AMMONIUM, 



97 



water used be very emiLll. Ali*ohf»l tdm attracts the ciirbaoiate, 
leaving tbi* biesirlHtriate undLsiiiilvt'd In runtai t with writer the 
«-urbuiiii*le 8<M>ii iliiiii^rs hilo iHiriniil iimi»if>niiiin mrboimti*: — 
Nli^N IL^IJUj ' llyO = (Nil j^C*J^ ; **<> ihat iiri jHjutuus f^ubitinji 
of comnjLTt'uil juiiiiioiiium nirbfjuaU' iM^itaiiis butli bythogi'ii, uni- 
Tiioniuni rHrb(»nMU\iiiit! iiorniMl iiirimtiiiluti) airbuufite. it'tuKiR-b 
a sulutinii, titmiv ;iimii<niia \k' Jidik^d, a «<4iiliaii of nftrmaf nm- 
mmtium carbottntr it^ uhiiuuvd: this is the t'oiunuKi reagent fouuii 
on fhet*beiv<^ t>f tlie :iimlytioil laboratory. Thuw, ** Aiiiinuiiiiiiji 
Carbtjiiute Test Solution/" V. H. 1*,, m prcpareti hy tlixiiolvin^ the 
coimiiereiiil ^alt in wiit<-*r U.* which wolntion of amrncmia. hn.^ \n\-n 
aiUled. 

Nn.IICU,,Nn,NlI,CO, l yH^OH - 2(iNHj,C0, 

Normal aunnonium carlwinate h the iMilt formed on adding ron- 
ceiilralHl Holution of auininiiia to the eonimereijil eurboniile in 
|ire|»jirin<^ u punjj:eiit mixture f*>r toilet smelling-bottles; but it i>i 
uiistiible, and on eoji tinned exposure to air \» converted into a 
niUKs of iTy!-.tiilK I if biearbimate. 

If ainmoninjn eiirl>tmi»te eontain njore tbiin Iraeen of emjjyreu- 
ruatic ntatlerH {\hmi the ga^-bijnor), an jojUeoUK wjlntiuii nf it, 
with exeesH tif sulplitirie aeid added, will at yncc deeolorize a 
dilute .sfiUitioii of [MdHKHiuju perinaitgauate. 

Sal Vohifik {Spiriftttf Ammftrtltf Armnalintjt^ U. S, P,), 18 a sjiirit- 
uoim j^>lution of ab<»ut 1 pereent. of aininonin, NH3, nearly 4 [*er* 
eent, of nnrnial anini*»iiinin earbnnate* (NH^)^(;()j, with r»ilii fif 
nulmeg, leaion, and b^vender flowers, (/ojnniereial samplers eon- 
lain hjiILh rijuivab-nt t*p from 1 to nearly Ji (>ereent. of amnioida, 
the olfieiaj npirit yielding a total rd nearly 21 pereent. of the gas. 

AmmomiiirL Nitrate. 

Experiment 4, — To noine dihite nitric aeid acbl ''amniotiinni 
carlKHiate/' uiitil after well t*tirriii^% a slightly nnunoniaeal 
Oflor rcniaius. The solntiou contains anit«oniuni idtrate. 

N*H,Hro,,NII,XFLC(>3 f aiIXO,=:)NII,Nf»3-hH/) t 2C(), 

Amtiiontum h5'itmi£tn iRrUiante Nlirk Ammonium WaIct i'«rtmiiii* 
(itnl 4-Hrbionate achl iiltmlL' ftnhydrulc 

From a eoneentratai hot wdutirm of ammonium nitrate, ervK- 
UIh may l>e tibtained ecmbiitdng niueli water (XH^NO,,, 1211,0). 
On heating the-*' in a tlish to :»lion( .ll^ft"* F. (lf;n° C\) the water 
€«ea|»'j*. Tbi' fuH4*d anbydnms w^U n^uiaiiun^ (NH,Nf),j may l>e 
|i4»ured nut on an iron plate, i hi fiuiher heating thefur^rd nitrute, 
at Hhi^** Ui 4o(PF. (about 177' U* 2:i2^Cj, it ia re.sf»lved into 
idtiTiui oxJde or lnHijhuiff-tfni^twuX water, NFT^NO.j — N^<> -h 2Hjh 

Niirowi oxide b prepared in this wiiy for une i\^ m\ Hnje?athetie. 





THE METALLIC RADICALS. 



Whvn re<|Uireil for iiibiihiti<^Ht it is wajsbed from any trace of 
intrii* sii'iil r>r (litric nxhW hy Wm\i jju^st'*! llirou>rli »i»lutii)D of 
[)oias.'*iuui Irvtlroxide aii«i sotiiti<ui <il tenous siilphutr, the J'onnej 
ahsurtiiBig at ill VitjiDrs, th«' lattiT liitrir uxiiit\ It is ^ligllt]y sululik 
in wanti uati*r, iiinrt' wi in t'ukl. It t*u|iiKirtH i^imluisiion itlnint^t m 
well Its nxy^tii. By the applitatioii of" suftirient [>rt^Hnrt' it umy 
he retlut eil to II rolorle^H liquid, and by siniult;ineoijs einduig it 
cHii be sfdidiliixL InbabUinii of a mLvhin^ of nitrous oxide and 
air i-auscii laughter or other exei tome lit. 



AmmoMiiiii Citrate, Phosphate and Benzoate. 

Experiment 5. — To ii ^dtitioo of eitrie aciil, H^C^HjO,. add 
atnmoniii water until tlie welKstirred li^jiiid htuells faiully of 
animouiii. Amnioniuni |dii»s[djate, lNil^»,^lHH\ nod nm- 
moaiyio tic*iiit*uit*% NU,( *.Hj^i).. iAmntifttii Ue/tzoa^^ L. S. I\ k 
are also niiide by add in j: aiimioiiiu vviUer t<* jjlux^pliorir aeid,, 
lfjl*()^, aud betiitoic ueid. H(*jHj.O^, reH|>erlfnny, ev»|*onitiu^ 
( keepiuix the amniuuia \u slight extM3?w by adding tuoru of iu* 
solution ), and setting iiside to erystalliae. 



H.r'o. - 

Phosx»tii>ric iicid 



HN,H,0. 



AiiniinTiiiiin 
hyilruxUle 

2NH.OH 

Ammoiilym 
hydrtixMe 

NH/)H 

AniiutMihjtu 
hydroxide 



(NH.),«VIA + »H.O 

Aniiniiiiiioi]! citraio WAt«r 

A in iDo 111 urn ph<>9phttU} WiHer 



Amnioniina t>lio?i}diate octufh in tninsjiareiU «y»lorl«!»»8 prismis 
scdubb' in water, insi»hilde in ulrohol; ammonium ben//mte otvure 
in ery^t^dline jdntes, niduble in water and ia abohol. An ex- 
ten<led formula for ammonmm lM'a//mto is (.UL.UJONH^; for 
amiiMinium eitrate. t\H,.Oir.fCO(LMf j,. 

Amumtthtm Bromidr, NHJir, (Ammanii Bromidttm, U. 8. P.), 
will be notic^ni in conneetion with Ilydrobrraaic Acid and other 
lironudt^. Aoiiuoaium Imlide, NH^ in also ottieial (Ammottii 
lodidum, U. a P.J. 

Ammomum Oxalate* 

Experiment 6, — To a nearly iMJiling scdution of 1 jMirt of 
oxalie aoid in about -S of water add nrumoriium earbotmte 
otitil fho liquid is neutral lo teat-paptr (^r tollowiii;? jmm- 
graphn), fifter while hoC, and f^l iLnide to crvstallize. The 
pnHituI h Animonium Oxaliite, U.S. R, ( Nil j.C\i),,H/Xor 
fCOONH/ij, lljjO. A ardutiori of it h umi\ n^ a migt^tit in 





AMMONIUM. 



99 



analysis ; 1 part nf the pure a^ah in 2.5 of water forms 
Ammouium Oxalate Tc^s! Bolution, U. H. P. 

Ojtallc '*Arnnioiiiiini Ainnioiiium CHrlxjulc Uaivr 

Acid carboimte* oxalak^ aiihyUrlde 

Neutralization, — Thus far ihe meth^Mb l>y which the student hjisi 
avc»ideti excess of either iiriti miittt r on the cme liiiinl, *tr HikiiHiie 
on the other, have been the mugh iiid uf liLste, ee-sNitioij of eller' 
veswrenee, jirej^euee *ir abs+enee of twlor, ete* More delieute iiJd if* 
aftVtrded l>y ft^f-paptrit. 

Tfjtf'pajfei^M. — LitmUrf i?^ a bhie ve^etalde jfij^iiient, jirepured frniu 
VurioUH speeii^8 f»f Rnerr/h liihen, i'Xrmliiitj;lv .stMisitive to Ihe 
aetioii of aeidi*, which turn it red. Whro the reddened, tdkaliert 
(eau«tic [KtUi**h or wida, and aiiini<>nia)j and oilR^r ndutth^ hydn>x- 
ideM, also alkali-ujetiil earlnMiitten, etc., rradily turn it l^hie. The 
student fihuuld here t«\sl for hhiiHelf tlir di Ihaey of iliin action by 
experinientj^ with paper ncuikcd in ,S4>hition td' litmus :nid dipped 
into very dilute y^olution.s ipf aeids, aeid .salts (r.v., KIH^H^O^]^ 
iilk:die?<, and such nentral .silts us jMjt!isi*iuiu nitrate, sihUuiu sul- 
phate, or ninnnunuin ehh»ridc. 

IMmw T^Jif SfifitfioH {V. S. P.). — This is prepareiJ fruiii purifieri 
litaiUM. Geutly *Joil litnlUi^ with four times its Indk of alrolud 
fur an hour. Pour away the tiaid and repeat the operation twice. 
l%c?*t the re><idual litmus in cfild distilleil water and filter; then 
extniet the residue with five times its weight of Imi ling water, and, 
after thortm^hly cooling, filter. 

H/itr fifmu^'paptT (IKi^.V.), is made hy iiiipregnatint? nnglazed 
white paper with a solution of litnms. /{rd HfniKM-pnptr (T'.SJ\), 
h made by iniprt^gnatiiig ungla/rd white pajier with sulirtiim of 
HtinUM, reddened by the previous addition rd' a very miuule ♦juau- 
tily of hydrochloric aeid, 

Tftrtnrrir jmjtfr (U, 8, P.), aimihirly prepare<l from Tunneric 
Tincture (IT. S. P.), i^ occasionally uj^diil lis a test for alkalies, 
wfiich turn it8 yellow to bmwn; acids do not afieet it. Several 
other •'indicator>i" f)f alkalinity or acidity are used, su*'h as 
Methyl Orange, Phcnol-phthalein, and Coehiueal T*'st Holutions. 



Ammonitim Hydroaulpkide and Sulphide. 

Experiment 7, — Pass hydrogen snlphlde, H^K through a 
iruall (piantity of aiuTiionia water in n tej^t-tube, until n jMir- 
iion id' the !i(|niil no longer cuuses a while [jreetpitnte in mdn- 
tiori of nnignesinni Milpbate; the jiriHluctigastdutiou of anjUKv* 
liiiini hvdro^ulphidc, NII^SH. 

NH.OH M^S NII,SII t \li} 
**Afnmoniuru 8ul|diide Test 8<>hition/^ \J* H. P** w nmde by 




iiK) 



THE METALLIC RADICALS, 



sat uniting 3 parts by measure of ammonium water with washed 
liydnwti 8yl[ibide, mul tluTii adduig 2 [mrts Uy iiieaf<tiro of 
tinimonia wukT. Tlit^ siiluiiuu should be jirtaerved iu a well- 
t<to]>]KMl huttlt?. 

Jlijthoijen Sftlj>hltie or stfJphureitrd hijffrofjen i« » jM>isoDOUS 
^;l^ [MjKsej^siu*; an taipWsatU odor; henet^ tlie iiliovr o|nTtitiofj 
a ml mniiy others, dc^TibtMi (urlliir on, in wbicli tbis pis is 
ittdisjH'i*!yil>lc\ uiU8{ be |H:*rformiAl in the open uir, or in a 
j'uun*i'f(pfjnftni—n ebanilier i^i <'(intrived that noxious ^ni^vs 
and vajMjrs sball e>H'a|X' into n ^hinruey \n Cfirnnftittn vvilb ttic 
external air. Iu the alM>ve exjH rinieut, tlie j^niall quantity 
of pis reijuired eau lie uuide in n tesl-tulie. llaee some 
fra^rneut.s of ferrouw sulphide, FeH, iu a tet't-tube, adil water 
and then aulpluirie acid; the ^as m at oriee evolved, and uuiv 
be eond noted hy a tnt)e int*i the ammonia water. Ferrous 
8ul|diate remains in wdution iu the |,'eiu^ratiii^f tube: — 

FeS j H ,S0, ^ Hp + Fe80^ 

As \wM if* not ueeessary in th^ preparatiou of sulphuri^tled 
hydrogen, *'Hydro^eu Sulphiile,'* F. K P., the tei?t-tul»e of 
the foregxiiujr ofreratitai may be advantageously rephiced by a 
liottli\ espeeially when larger <juautit»e.s of the gas are re- 
quired. In analytical opera tii>ns» the gae ghoidd Ik* purified 
by jjnissiug it through water, contained iu a second bottle* 

Fi(j. 20. 




Hydrogi^a sulpbtdti u^jpaniliai, 

A convenient apparatus for ex |H-ri mental um in arnuige<l 
as folhws : — Two eonudon widi'-moulhcd liottlen are Hc»leeleil, 
the one having a eapa<*ity of uIkjuL half a pint, the other a 
(juarter j)int; the former may be eaUed the ffrtterttthnj'f>*4ffe^ 
llie latter the waxh-^biMk. Fit I>oth boltlea with good sound 



AMMONWM. 



101 



_oDrks, Through ea<^h rork lH>ri- two Imles of sueh a mx^ Uiiit 
riass tuhing of nlMiiit tlie (iiivmeter of ii (juill pen sljall fit 
liem ti^jjhtly. Tliruu^li oiii' of the holL'8 in the fork of the 
gen era tiug-1 Hilt le psu^.s ii fuimel-tiibe, so that its extremity may 
jieurly reaeli the Iwvttum of the Inittle. Tn tht* either hole 
ii<la|»t a piece of tnhiiiLS *^ Jiiehes l(Ui;jf, ami bent in the niiihlle 
lo a rijj^bt angle. A Hiniihir *'elhow-tnlH* " is Httcil to one of 
the holes io the eork iiX the wash-holtle, juol anotlier elhovv- 
tube, one ami of whieli is h>ng enough to reaeii near the 
iH^ttoni of the watth-lmttle, is fitted to (lie other lKjh\ Ke- 
nao%nng the eorks, two or three ounees of water are now 
IKiured into eaeh bottle, an ounce or two of ferrous sniphiile 
put into the generating-botth% and the eorks re|>laced. The 
eHw)w-tul>e of tlie geneni ting-hot tie is now atlaeiied by a short 
piece of India-rnl»!Ker tnliing to the long-artntHl ellwjw-tnhe of 
the washdiottle, so that gas coming from the genenitor may 
paiw through the water in the wush-bottle. The ilelivery-luhe 
u^ the wasb'tKitth^ is then h^nglhened hy attaching to it, by 
means of Imha-rnbher luhing, another piec'c of glass tubing 
.several inches iti length. The apparatus is now ready for use, 

-Ctaieent rated 5^ul[jhurie acid is [Kjured down the funnchtubc in 
[jail (juantitiea at a time, until l>risk erterve^scent^ is estalv 
lished, and more is added from time to time as the evolulion 
of gas l)ecomt*s slow. The gas passes through the tnlies into 
the wash-Wtle. where, as it biildib^s u|> thnnigb I lie water, 
any trace of Hnlphurie and, or other matter me^'hanirally 
carried over, is arrested, ami thenee the gas Hows ont at the 
del i very -tul)e into any ves.std or liipiid llmt may he placed 
there to receive it. The generator nvust he detached necsk- 
sionally, and the ferrons sulphate washed out of it. Should 
diffi«*ully Iw exjKTieiiced in obtaining snfficiently sound corks 
ti» make gas-tight fittings for the a|iparatus, double-bored 
rubt»er stoppers, obtainable from any apparatus detder, may 
Ih* rm|>loyefi. 

Hydrogen sulphide dissi>lve^ in water to a moderate extetit. 
yielding a Bolntion which smells strongly of the gas, and is 
Imjuently empioycil a.s a reageiit. Wfa-n the s*ilution is 
exjMi^*e<l to air the hydrogen sulphide rapully ujidergoea 
oxidation witli de[M>mtion rif white sulphur: — 



2H,8 4^0, 2JIp + 8, 



102 THE METALLIC RADICALS, 

Analijfical lieadions of Ainmafiiunr iSaltM, 

1. To a solution of an aiiimoijium salt f uiiimonium ehloriile, 
tor example), iu a test-tyUe, ailii solution tif i^tnliuni hyilmxide 
(or fXitassium liytlruxide, or slaked lime), anil wariii the 
mixture ; a charaeteristic odor faniniouia, ^iH^) results :— 
NH^rH NaOlI - Nil J H,0 r Natl. 

The re<*oguitiou of the odor of aiiiuionia m one of (he 
readiest Jueaiis of detwliug the prt^t'iuv of Ihis BylK*lanee; 
liut the following lej*ti< are oeeajsionjilly useful. Into fhe 
upfjer part of the teM-tuhe insert a gliLss mA nioii^tened willi 
eoneeiitrated hydnx-idoric add (that is, with the acpieons 
stdutiou of hyilroehloric add gas convent innally termeii 
hydroetilorie acid, the Acid am Htfdroehlonrum of I he 
P(nirniaeo|Keia); white fuiaes of aniinonium efdoride will 
he pnnlyeed i — NHj j HCl^NH^CL Hohl a piece of inoitit 
red litujnir^pa]>er in a tiilve from whieh nnnmmia is hdng 
evolved ; the eolor will lie chun«^ed to blue. 

Though ammonium iti^elf eaiinot hi' nhtrtined hi the free **tjite, 
it« eoiM|M>uud^ lire stable. Ah the fore^oiti^"' i^xpirriiiient nhows, 
ammonia h ea^^ily expelled from tin He eiim[M minis by the jnti«in 
of the »tnin^er alkalira^ eaui^lie polish, einistic wMhi, or shiloiMl 
lime. Ah a iis*'ful exereise, the student shoidd here eonstraet 
eqiiatiouH in whirh ammonium neetat*\ Xn,CJI.,Xj, sulfVhHte, 
(XH^y^O,^ aitrJite^ Nir^NO^, or any other ammonium salt, U 
mippojiic'd t(t lie under exuminatioii; also eqnalhias representing 
the UJ^e of the nrlaT hydn>xidi^, KOH or Ca(()H).. 

2. To a few drtvps of a solution of an ammonium salt, add 
a dr(»|i or two of ehloniplalinie aeid, H,PlCl^; a yellow eryu- 
talliiteprei'ipitateof anmioninin rhloroplatinate, { NH^)J*H 1^, 
will he produeeih similar in appeanineeto tlie eorre.H^K>ndiu|: 
jxjtasj^iuin hjiU, the remarks eoneernin^^ whieh {y<tT p. H2 ) are 
ecjually applieable to the preeijatate under notice, 

^. To a moderately eoneentratetl .Holulitjn ofamnajnium mU 
add a saturated solution of j*o<lium bitartmte, and shake well 
or stir the mixture; a white granular precipitate of ammoniinu 
bitartrate (aejd ammoninin tartrate) will be formed. 

For data from whieh to eonj^trnet an ecjuafcion representing this 
action, see the remarks and formuhe under the analogous poias* 
muin salt (p. 83), 

4* Evaporate a few drop of a sfdution of an ammonium 
sail to dryness, or plaee a fra<?^ment ofafwdid ammonium salt 




LITHIUM. 



103 



on a [iivLi^ of pint it) 11 in iWiU ami Iwni m a flatiie; I lie wilt is 
readily volatiiiztr!^ iLsiuiUy with <le{M^ni]M>*iiLioiL Ae already 
notice<l, the siiilts of |K>i!»!isiiirri and sodiuiii »re fixed ( /. r., non- 
volatile) under these eiieumstaiiee>H, a jxiint of ditferetiee of 
which advanta^'e is frequently takeji in analysis, A pireehiin 
erneihle may often be Hilv:tntuire»>Uf^ly t^ubslttiited ibrphuiiiuru 
foil in ex|)erirneiit^ on volutiHxiition. 

Salti^ ofannmniiuin with the more c<jm]»lex ai'id ntilii'iilj^ t^eldoiii 
volatilize unehimp-ed when heiitect. The oxtihiti', wlii^ii so tnvuted, 
loxe.H its water of frvHlalli/jitiun, tind at a higher temf>enitnre deeom- 
[Migi's, yieldinj^ cnrl)onic oxide, I'^irboaie anhydridi\ luiiinuniii ^iis, 
wattT, imd HL*ver.*il orgnnie suhstiineew. The [>hn»phiite ht^va watiT 
and ainuioiiiii, and yield?^ n renidiie of melJi|ilios|ihi>rie iteid. 

A ttnrf t rift ftff/r limy be umhI in t^upporting tTUcihles (Fig. 21), 
It is made by twisting together eiuh pair fit' ends of three (fi- or 6- 
inch) erosHed piee^^s of win- (Fijf, 22). A pieee of tol>acco-pipt* 
stem (about 2 inehej^) is Kouietimes pliieeil in the ujiddle of eaeh 
wire belbre twisting, the Irnnsferenee of any metal lie mutter to 
the aides of the crueihle l>eijjg thereby prevented (Fig. 23), 



Fia 2L 



Fio, 22. 



Flo. 23. 




TrimiiTultir supi^ortji for cnidblea. 



LITHIUM ; Li. Atomic wdgbl, 6 98. 

Lithiiim ii^ widely di»trihut<'d in nature, but i:^ usually iti 
miriute pro[iortifins ti>* roin|>arrd with other elenientK. A tmce ot 
if may he found in most *wmU Hud watt-r^, a rert^iin sprinjyr in 
C'Ornwall eontjiininp even rorisiflernhir rjuaiititiei* an idiloride. 

Lilhiuiu c'4irlHniati', Li.rtJi, {JJthii fMrbonas^ U. S. P.), i** a 

Ln'hite grariuhif powder ohttiim-rl fruiu the minerals whieh eontain 

■lilbium — namely, k^udolite {\T^nn Afrri*:, ff/tij<^ a Hri\h% ntu\ /i^e*^, 

liiftm, n «lonc» refi'rriug ti> it,-* s^'aly appearjuicr); triiilianc' (\nmi 

rpskf /r<fwf, three, and ^vinvj, phninn, I shim*) ar .**|»<M|iimene (rrom 

iddwi Mpoddo^ 1 reduce to tushes, in uHuNiMti to its i^xlobntitai in 



ln4 



THE METALLIC RADICALS, 



the bl(w-pi|n* lliiiu*); aiul petalite (from 7rfTfi7j^v, ^^tinimi, a leaf^ 
referring to itn lunnimlecl eiianiekT). Hiuh efuitiiins uluiiiiiiiuiii 
silieate, with j>t>hi>f.j*^iuttj hihI lilhiiim flii^iride in the euR' til Au^- 
Irian leiiitlolik" (wlik'b is the most abuiifliiiit si>Mree) iiiiil s<>diuiii 
aii4 lithiiini wilieaten in the utliers. To j*c"parate tlie litJiium, 
lepitlolite is deeomjuised hy i^iiliihunc aeid; aluniitm, eti'., preeip* 
itiitetl by aimiionia; the filtratvd evaji<irjite*l atiil the residue 
ignited. TJie resulting sulphate,saredisvSolv*'<l in water and litbium 
carbonate is prei-ipitated by adding a sidntiou id" a rarlMJiiate. 
The jireparaticui (^feomnnni alum in mnnctiineH made a part *>r the 
far til rv ]»roeesseH. Lit hi i ihrhuma^, U. S. P,, i^ *ifdidde in 7f« parts 
ot water at ll^i^. and in 140 at UK)" C. 

Lithinin eitrate {Lifhii (■ifrajf^ V. 8. P.), ia ns4"d in nieilieiiie. 
It iieenrs in white delii|ue8cent eryntals or powder, [irepared 
by sfduratinjLir eitrie :uid with lithium earbmate. The erystal?* 
havf the formula Li,tyi,0,, 4H,<); dried at 212^ F. tlUtl*' C), 
Li/^IIjt),, up (I'mneyi. 

3H,o -f nax 

Water ("jirlmtilc 



3Li,C0, + 
Littiiani 
eiirlHuiiiic 



2H,C.H O, =, 2Li,C H/>, + 

fitrie iicM tJUda ni 



t'i Irate 



Lithinni eitrate shrmld yieliJ by ineineration fi2.S percent, of 
while bthium earlKtnate. Lifhti Ciftftj^ Ej^erct^cetiit^ U, S. P,, in 
pre]mred hy mixing lithimn eitraU' with eitrie and tiirtarie aeids 
and sMidium biearhoniit<\ then hi-ating and stirring until the mixt- 
ure assujne?^ a p^ntnular character. 

Other nlfieial salLs of lithium are IJfhii Bemam^ U, K P., 
Lii\}Lt>.^; Liihii Hrmmtiam, \L H. P., LI Br; and Lithii Salkylm^ 
U. 8. P., LiCyijOa. 

Lifhhim tiniff'^ la more s<^dnhle than sodiuai ttrate; henee lithium 
J » reparations are administered to ^fouty jiatient?* in the hope 
(apfjarently *]nite nnintelligilde on any ehemieal jrnmuds} that 
widium urate, with whii h .^ueh systems an? icnided, may he eon* 
vertefl intfi lithium urate ami removed. 

In its analylieal Itehavior, lithium stands in s<inie rcspeelR 
between the alkali-meUds piUasnium and sodium, an<l the njetals 
of the barium group (barinnr, j^trontitun, and (aleium) its hydrox- 
ide, carbonate, and phosphate being only slightly ?^«duhle in water. 
Lithium ehloro|datinate, LiJ*t« 1^, is s<iluble in water and aleidiol. 
The Htmn of lithium is nnivalerit, Li. 



Anahffiral Heart hnts of Lithium Sfift^, 

1, To a Rilntitm of lithium ehlmride, IaV\ (ohfuiued by 
diasolving a tew gmins of lithium cariMUUite in ililute hydn*- 
chiorie acid), add n siilution of ordinary ^Hiitim phosjdiate, 
Na^HPO^, ami a little sodium by<lroxidt\ or ammonia water, 

^Unites will he frni^idrrLnl Huhseqaeatty in roiinc<!tiun with uric acid. 





LITHIUM, 



105 



N 



Qd lM>iK A white crystal line precipitate of lithium pho»- 
bttte ii? prod need : — 

riLiCl i Nu,lIPO, 4 NaOH = Li^PO, -f liNaC 1 + H/:) 

2. Mdiflteii the end of !i platinum wire with ii t^olutHiu of 
lithium S4ilt» aud iiitrodiiee it iiili* the thtiiie of u JSuil^u 

burner or spirit-lamp ; a magniliceut crimson tinge ia im- 

parleti to the Hame, 

The ligbt iIiub emitted hy ineaiiflet*ceut lithium vapiir in of a 
purer eririi>win than that given hy ,Htroutimn. When the ttiiuies 
are examined hv iiinuis of the HpeetrMS<'n|K' i\w retl rays an- jn the 
caR* f^f.stnmtiuni, tnijml to he iiHrtdfiatrd with l>lue and yellow, 
neither ot whieh is observed ia the lithiuin light. 

Qualitaiivt AmityitU. 

With repird lo those cd* the priM tnlin^ ex|N-riment« whieh lire 
Ui^'ful rather ii8 means «>f deteetiii^ the [>re>*enre <d jiot^^ssium, 
Bodinnu iiunnoniuiii, lOjd lithium (the !*(>-ealled **te,sts"), thsiii as 
illustrating the i^rrpsiriition ofsiilts, the studejit sliould [>nKei-d to 
a|»)dy them to certain nolutions of any ol" tlie Hiilts of these inetiillie 
ruiiicals with the view of aseertjiiniiig whieh radical is jirt'sint; 
ttutt is, proceed in pnirtivaf (ttitthjm^.^ A little thought will cnahle 
him to a]»ply the reactions in the most suitaldc order and h> the 
he»^t adviifitage tor the cioitemphiled purjiose; hut the fidlowiag 
amingemeuls are perhaps as gocwl as can Ikj devised :— 

DlRErTIONS FOR APPLYINM THE ANALYTICAL REACTIONS 
IiliHCRJB^D IN THE KORIvtSOI N(J I'ARAtJRAPIlS TO THE 
ANALYBiaOF AN AQtTI-XUTB i^>LlTTION A SALT OFiiNlC iiV 
THE METALLIC RAIHl'AIJ^, IHYrASMllTM, ftOIUlTM, AMMuNUrM, 
LlTinrM. 

To a s*nmll |>ortion of the solution to lie examined^ iti a 
le^t-ttihci add stidium hydroxich^ te,Ht solnli<m, and warm the 

' Siu'h MihilioiH Lin' pn-jiari'd in I'dtirutloaaf labonitrint^ hy ii In lor. 
They i^liouliL a«Kh*r utlicr rircioji3t;*acH'f*, h*- mixed t»y a frk>iMl. u:* it is 
tint rl<*<^iral>lH for tlir htiicloiit ic* kiiow pp<"Vioiihly wlmt is rojitaiiu'd in llie 
ffiibMfaiw'r hi' h :iHiiiit ImKinlvKc. 

Tbo AiiiiiyHtH of ^ihitioii^ ctiataining: m\\y one salt sr^rvrrt t^1 impr<'ss 
the niom*ir.v with the fhiimcteriHiit^ tcstH for tho viinnas nu<lii11ic tiial 
ollu't nidifrjils, Hiid lUniilirtrivse ihe rniiul with cbcmiciil prineipk'S. 3ff<'<!i- 
cjit Hti)rL>nt« M*1(h»m have tinuMo ;^() fiirth*"r tlmii tlit;*- Mtn-o rhHr«iii|!:li 
mi ' ■ u! ijcnrml rht-mlful kntmlt'diif^' Is only nnij,uipfil h> wtirkiunf 

oil im"« f»f Hiiilmtunn's as urc mot with ill iiutnul |»nulin\ hri^in- 

iiM^ .|i»ti<ins whiili nmy cotitain nny or all of the rni'mhciiH oT n 

irrtktip Hriu'i* ill this Manual two tntilrn nf filmrt analytiml liirertionsaiv 
k1%*i*ii uiiikr each gruu|v IMiuniiHci'iitit'ul stiidt'hts shuiild Ibllow tbi* Hi>cond. 





lOf) THE METALLIC RADICALS. 

mixture ; the iwltir of ammonia ^as reveals the presence of an 
aiunioiiiiim ?tnh. 

To a few dro[jsi uf tlit* stilmiou* aj>p!y tht? bismulh thio- 
sulphate test for (iotaasium {p, 83); a yellow precipitate 
indicates the prej^enre of ixitaivsium. Poijia^inni may also be 
ilete€te<l by means of tlw ehlurMplatiijie arid ie»U but only in 
the known ab^icHiee of aniiuoiiituu i^alLH, 

The f!inne-le«l l& ^u(iieieiit for I he reuoguitiou of sodium or 
of lithlunu 

DiRKlTIOXS FOR APPLYING THE ANAL\^TrAL REACTIONS 
DV^it'EIBED IN Till-: FOREGOING PAKAdKAI'HS TO THE 
ANALYSIS OF AN AlirEOUS HULUTlON OF 8ALTW OF ONE OR 
MORE OF THE ALK ALl-METAlA 

I. In fiif^s when it in not neL't^8j<nry to effect iietnal w.^jjaration 
of the iintidHr radicals pre^s^fnt, the exiuninnlioa r>f the Milutinn 
riuiy iie.st lie carried out by making »pecia! teat« for each oi them 
a^ hi'lf>w : — 

Tj II rtiijidl portion of the j^jliUion in a toHt-tnlw', iidd SMdinai 
liydn)xide and warm the mixture; the cnior «>t' aaianuiiii reveid-s 
the jireH-ence of an iiTinnoinaiii sjdt, 

A]ij4y the hismnth thinsulphatr test for jwitassinni t<* a ("ew 
drojm nf Ihe .H4>]ntion (p. H'i). The foraiation of a vellow pre- 
fipjtate indicates the preKt^iiee of a ikotassiuni i^iltJ 

Til another portion of the soluiion add siHlinni [Jir^phate and 
then annnonia wat4>r until the lii|uid, afUr shaking, wjuells of 
ammonia, and lM>iL The furniation af a white prccijntjite iadi- 
catrs the pre>?ence of a Hthiuiu wilt Test for litliium alw> by the 
fl;n 111 'lent. 

The thnne-teat is sufficient for the rei't»gintinn of sodium unleHsit is 
presrnt in y^nudl <|uantity along with niiich lithiu*iL In such a ea«? 
thf sisLctrosi'npe may he eaijdoyed. Tnuet* of fithmni may also l)e 
• k'tected in pres*ence of much H>iliuin hy means of the .HpeetrMj4co|ie. 

Xoff on fhr Jhxmt-tvift^ — Whiii the violet tint iaiparted to the 
Ihinie by potaT^Hium ^dt*^ is aiasktnl by the intent? yelh>w color 
due tosoflium, it amy still l>e rerogni/ed, in the abftenee of lithium 
^alt^ if the flame be tittsi'rved through a piece tif darkd*hn* ghiKH, 
a mediuai which abs<»rbf* the yellow raVK of liglit hut allow,s the 
violet rays to jia^M, It h not sjife to exaanne a *M^4ution for 
poUtssiuin by the flaino-test in the known presence cjf lithium salts. 

II. Slinuld it be ueci'ssar)' actually to N'panite the mi'tallic 
rar heals iroai one another, thf analysin may In- carried out ac* 
cording to the tVilIowIrig methtwi : 

^ If fiti iiniTiinriiaiD siilt hv pri"$i>ni. it la (kviiraiae ta^ctridof it lus 
iltseribyd undvr IL, before ii)»iilyiiiK thw U;&i for |K)lu»ikijm. 



LITHIUM. 



107 



( Vnjtiurnci* hy ti^tin^' a hiujiII }Mirti<*n #if the Hnlutiim for iin 
ammoMiufu anlt; it' it ht- prt'^^nt it imiHt he ^ut rid of |>ri<»r to 
ti^-^tiiig fur (iuitl if [>n->ieiitj reiiioviri^) potiL'^siuni sis rhU>rojiJii- 
titiutc. Evaponiti' Ihi* reinuiinlir itf ih*' urigiiml f^olutinti to ilry- 
ni*!« in a hiuiU buHiu, triuisfer the solid reHuliu-, hy iiistjihiieiits if 
necesJ«Hrj% to ;i jiurrcltiin (Tut'ihle, tu\A htuit the 1 utter U\ low red- 
nes* until vvhitt" fmin^s, due to the decMiiiixisitirni t»f iiiiiUMuiiuiu 
Rait*, no longrr esrapi' {xre V%^^ 15*). This optTutinii ^ihoold l>e 
c^tndut'ted inn fiiiiie-c"iJ|)l>o!ird, toaviiidcontfliiiinationof the idr of 
the luhfiratui-y, WIilii the <_rueihk* hiiH cooled, diw.*<(dve the twdid 
residue in a jiniall quantity of hot water, filter if ueeet^tirv^ sidd 
excejsa of ehh>ri»iihitiiiie arid (/. e,^ add j*uMieh iit of the reagent to 
convert the whole of the alkuli-metiils preH.'nt into ehloropla- 
tinates) tind evajiorate to drynesa on a water-hath, or iit any rate 
ftt a temperature not exeeeding li)0° V. Digest the rej?idue for 
snmc time? with aleohol, and iilter : — 



Bendne, — A 1 1 eu v y 
ellour |Miwder eon- 
fftiMlinp of pohiKsiurii 
ehloroplalinnte, 
K.Pttl,. WsHh with 
a 1 eoliol ; d ry ; 1 r- n in- 
fer lo a poreelnin 
^CfUi'ihks niui UvM 
adutiily uj» to ixsh 
' II ess. Trent the re:^i- 
<iiiL' with hoi WHter, 
und lilter; 



Ucjtufitt,— 
Con**i«t« 
of 
plAtinniu. 



FtttrrtU, — 
Con in inn 

pohtssiuia 
L'hloritle, 

I (A)iiilrrm 

pnUi*.hnn 
hy I he 

llklUL'-tCKt. 



FUtvatt: — May contain sixlinm iiml liihium 
ehloroplatmrnew, with »-^iei\ss <»(' rhlni<nihitii(ie 
;ieid. Evapomte ^^r dhu\ otlthe nieoltnl, ami 
heat tfii rnlne>M the hnnvii solid wtiieii iXiniains. 
Treat the residue wiih hot water, and hlter: 



CVtnKistn I if 
platinum. 



Fdtraie. — M ay eon ta in Natl 
and LiOl. Evupanite to dry* 
ne^a* Treat rLpeatwIly wiih 
iilcohoh tiltenni? eaeh instal- 
ment. 



RrMt'dtiT. — 
NaCl ; ecm- 

finn hy 
Ikme^tesi, 



eontnin IJCL 
Apply tlanie-test 



Note on Nomt'nrhilurf. — The ojierationa of evaparnt'mn and 
heating to redne?**, eoinnionly termed ujrnfkm, tire fre<|Uently 
neeensarj" in analysis, and are n^tinilly eondneted in the idiove 
niADner. ff vejyetahle or animal in:itt*'r he pre^^ent alni^ earlMin 
b set free, and ignition i» aeeompjinied hv atrhtntzitfinn: the 
mntfTial in i^iid t(* rhttr, VVhen all etirbonm'etnif* matter is burnt 
off I the eriieible being slightly irielined and itM eover removed to 
fjicilitatr conjhiistion), and ndneral matter, or fW», alone remaind, 
the operation of incineration has bet«n etfeeted* 



1U8 THE HfETALLW RADICALS, 

Nofr fin the ChMifimHon of fhr Ekment«, — I'Jie lompounrl^ of 
]M4assiuiii, sodSmn, amitHmimn, and lithitnn, havo iiKin y iiniiloi^ioj*. 
Tiu* tiirliojiiitt^s, [thtispliiik's^ siiKJ <»tIuT riiiiiiiioti wiills iirt' j^olulilo 
ill wiiter^ extvj»t litbiuin c^trlHumle luuj pliai<|iKntv, wliirh sin/ ruily 
spiiriJi^ly suluhk'. AluniH af \\w iiirtiillic nuJinds sirt' tmivaliiit 
— tliut Jrt, erirli di.H](bi<u*s or b dispiuied h\ out' jiloiii of hydro^vu. 
Im tiii't, thene nirlit'sils toriHtituie by thi"ir siniilanty in [vn>jH'rti*> a 
distiiii-t group MT liimily. All thc^ olemi'nts tlniH nsituratly lidl iiilo 
t'la-^sej^ — ji liirt that wliould ron.sLsmtly hv iKtrni' in niiiidj and 
fviik"nre of wbirli hliuuld always Iw wnu^dit. It vvrtiild bi* ini|ins- 
Bihb' fiir the niejiHiry lu nlain ibe deUdU of tJbrmistry with- 
out a Mysteni of elus^sitiialifni and leading [irinriplt'S. ChLssiti- 
tttti<in is id?*o iin important ffaturt' in tbf art as wt'll us in tbo 
sident'eof Cbernistry; for witbout it [jnirtical analysis couM not W 
iindtTtitken. The i bisHiiiration itdopttnl in tliis Viilmnc is foundrd 
on Ibe (juantiviilent'e of tht' elemenln (or radit-'nlii) iind on tbt'ir 
analytiad and gt-iieral rebitions. 



QrRSTIONS AND EXERCI8E8. 

Why are rtmmoiiiiiin sjibn rlsi^wiMl witli th(KS<* of putrtssinm \im\ s<»tliiim? 
Mention the »ijiirt'i's nf the uiinnoiiiiini salts.~nr*vt'ril»e^ th** tlrameters 
of Aiiimniiiiiiii t'kkmde.— tiivi* the furiufdM. *if AiLiiuoiikiia 8yl|>Uate. — 
Addufo L'vkieiu'e of the existeute r*f Auiniuuium. — Hnw is Ainnioiua 
wuter pre]tari'dv — How is the otIieLul Solution nf Auimnrdnm ArrtJite 
jire|tfin^l ?— Wbul js the einuiKisitien of eommenial Aiiiii»*iuiuin (Atrium- 
ate?— t*<'line «MA/iirt«/ion. — What amuiotiiuiu i^aU in rfiTrtaiiieiH in Sf/hittu 
Ammonia' A tiimnticiin, U.S. F, ?^-(Tive diaj;riiiiis or tM]iiali(i[)H illuHtmliiig 
the biriimtiitti nf ATtimoiiimn Cilmteifrom ljy<lr4Jxi4tMiiid frem rarliun- 
att^L Phosjdiat<s and f{4'iizoiitii. — Give the formula of AriiiuoiMMm Uxii- 
lat*'. — ITctvv is aitiiJiunitim hydroxide eon verted into suJjdncle? -I>eNTihe 
the jirt'iuinitinn of Hyrln>j;eu Sulphide. — Eitnmenite and (•x|iluia lln^ 
tesli* for animfiniiMTu — Hi»\v ik p«it!iH-inm di'tect*^il In a sidudrm iti whirli 
atnnuniiyni hj*s ht*eii found ?— fJive equation.^ ilbi.Htnitin); the artion of 
MKliiHii liydroxidt^ on ainnioniam aevt^ite; pnt^issinni hydroxide on 
annnonimri Md|dnite : inul r;deiiim hydroxide on ivmnioniuni nttrat^'. — 
Xanjc Ibe sonreeH .iml ottbinl ciitniiounds ufUthiiun.— Ex[datn the foniia' 
lion of lilldKim ritmfe.— On whsit elieniiral hypntlie*!^ sir** lithiinn 
compounds adinini'it*'n'd to tfiaity patients? — Wlifitare the ehief ti-slji fr»r 
lithium ?— fJiscrilvi' tlii' muilysi* of an a«piious li^pod eontaininji; salt^ of 
|M»<jisMinni. fWHiiuni. arumoninin iind lithiani, — Wlmt Tn«'anin(f> are eimi- 
fm»idy assigned to the lerins erapomthn, ujnilimi, cnrhnHimtiort^ and 
iurintntlitni ' -Write n lihort nrtiek- d* "Script ive of tht' aualo|£ie»v of )M>t».s. 
sium, sodium^ ammonium and litliium atirl their eompcatndei. 



BAEIUM, STRONTroM, CALCroM. MAONUSIUM. 

These four elpnients have many aimkigiett. Their atotii« are 
bivalent— Brt**, Sr*", Ca'S M^'*, 



BAniUM, 



WJ 



BARIUM : Ba. Atomic weight, 136.1 



It is Ihe iinitlytirul reiictiuiiH *if thii* metitl wlucli are f>f chief 
inleresl to th«.^ stiiflcdt of |>liMniiJicv. Biiriuni uitndt% liii(X<.)5)y, 

LT, 8, P., t'imtiiiiit< I in l<>of watrr)arr thr soluhlr Kilts in fouitnon 
III* in jiimlyj^in. llii't^* and titbiT ^aJts are niiuiv by dissolving ihv 
mitivo larlwiniit*', BaUDg (the ruirK-nil trithrritt) m acids, or by 
bt.'!iting: ibf other t'omnioii natural i'i>ni|M>unil of buriuiii, \\w sul- 
phate {hravf/ white or hntrtj /tptir, HaSt )^) with coai, wbirb yirlils 
bariyui sul|djidc, BaS (Bii.so^H 4t/ = 4t'i M BaS), and treating; this 
with apjtropriiitr nvlds. When tht; Jiitrate i^ istrongly beoted, it 
ik*com|»o,*«fHj yit^diug biiriiiia i>xid«' t^r iartjia^ ilaO, By inti-nHcly 
bmthi^ VL njixtnre of Ifariuju Huljdiatc and <jirfKin in tlie elcrtric 
furoiU't', barium oxide nnxed with a small jm^jiortion of riulphide 
b now jirrjnirrtl ww i* hn'^x* i*eale. Itar) tb:i, on being aiiastened, 
unitos with the efeaicnts ol water with the t-volntion of nunh 
beat, and yields bariuai bydrtj.xide, Lia((>H),. The latter is toler- 
ably H»lubk'* giving fatty fa n*tift; ^nid from this solution crystals 
of barium hydrf>xide, Ha(< »ll).,Sll ,0, are obtained on evapomtbn 
Barium hydroxide is largely ws<d in the rtdiaing of sugar. 

Barium i}io.ndt\ BaO... is forin*'d in | lasting air over barium 
oxide heattHi to about t^tKf (*. At a *ioniewhat higher tempera- 
ture, oxygen is evolved and bariuai oxide reiiniins. This is 
BouBBingault'tt old process ; but, after a tiaie, the bariam oxide 
IcNieft it« powf r tA' eond>iiiiiig with additional oxygen. Jf the air 
be friH'd from carbonic anliydride, and the dittxide la* not eX|Kjrted 
tu a umeh higher temperature tbiui ?<(N!°(\, the liariuin oxble ean 
be used over and over again. The air is [wi.'vsed over it under iii- 
cri'aM'ci pressan\ and gives ris** to the formation of the ilioxidc, 
Hie air is then turne<l otf, ami the additituad <txygen is given U[> 
again when the pres**ure is sufficiently reduced by nnans of air- 
pum])i8, 

Hiidrotjrn DioicUir. — By the action of a dilute acid, barium 
dioxide yiebl** n wohition of hijiffutfjtn *lhxi'i*it\ Hj*^, formerly 
caIIihI f^ijffenattd uuifrt'. An aipieous H>lutifin of hydrogen ilioxjck 
which yieUls (by the ileetan[><i^iti*H! of the dioxide) ten times its 
%*t*lume of oxygen, is theothcial A'/mt iftjdtofjntii PifuifH^ U, S, 1*. 
When thi** solution is mixeri with a siitlieiency of diluted snlfdiurie 
aeid^ iUid Molulion i>f jH^tassium [lerni-ingiiniile is added in excess^ 
the dinxidr i« completely decomposed, uitb evoluting oxygen : — 

5H,n, ^ 2KMnn, 4 riH/i<)^ ^ 50, f 8H,I) + K^(\ + 2MniS0, 

CNie-half of tl»e oxygen conn^ from the dioxide and one-half from 
tile penmitrganati'. The dioxiile readily yitdds oxygen to many 
inorganic and organic subtstaiice**. 



110 



THE METALLIC RADICALS. 



Anidifficni Beactiom of Barium Sal fit. 

L To the aciueoiiK wjlutiun of juiy «oluble barium salt (nitrate or 
rhlnride, fbr exfimple) mhi dilute rtulphiine ticiii ; a white [treinjii- 
tilt*" i,s iil*Uiin«Hl. Set the le^t-tube lu^ide lor twu <tr thni* inintiteH, 
imd wheti wjrne of the jirecijMtiite Iuls IVilk'ii to the hottoni, jiour 
mvay the sufHTiiiitHiit li*juid, wiish tlie |ireei|>it.'ite by uilditij^' water, 
Hhiikiii^, Hettiiif? iiside, and apiin deLaolin>r; aiai thru aild luodir- 
aUdy eniieeutrated nitric aeid, and boil; the jireeipilate U Insiil- 
uble. The iirceiid title is at onee priKluceJ by the iidditiou of il 
^dutinn of tnleiuai Kulphate or other soluble j*ulj»hitt<*. 

The pnKiuetictn of a white [>rei'i|dliite Ity suljdiarie acid *)r *rtber 
!4ul)dijite, iu*Mduble even in hot nitrie aeiti, it* highly ebaraeliTiHlic 
of ImriuuK The iiret-ipitate conrtiHts of l>annm «ul|diate, Hai^U,. 

2. To a solution of l>ariuiii ^i^ilt add HJjintirjn <d' jNdiiHHiniu ehit)- 
mate, KJ'r*.)^ ; a fJide-yellow priH-ipil^ite of bariurn Ldiroinate, 
BafrO^, w iunnediately fornnHl. A<ld aeetie iwUl lo a portion ; it 
is ins<dnlde. v\dil hydroidilorie or nitrie aeid tu another jKirtion ; 
it dissolves, 

IVtassiuni dielironiate or unhydnH hrfnnate, Kjt'rOi, CHJ.,, c>r 
K.t 'r./J-, must mA be used in tliin nnietion, otberwisi' Iht.? barinni 
will br only partially juwipitiited, an the dirhroniute gives vim,' to 
thi' fonnaticin of free aeid, in which barium chrfannle 18 to »ouie 
extent sithible: — 



K,(V>4,(M)3 i 2Ilan, I 11,0 = 2BatVt», f 2K(1 + 2HC1. 

Otlier Analyticial Reactions. — To a solution of a bnrium 
salt arbl n H<dution of a earbormte (aminouiiitu enrlannite, 
fKll^)^l'U^, will ^^enerully be ratber more nn+'ful than the 
others); a vvldte predjiitate of barium earluuiute, JiaCO^, is 
tVjrnn^d. To atiotlier |«>rtioii of the sohitimi a<id ao alkali- 
metal phosphate (sodium |diosphale, NaJIPO^, is ibe moflt 
I'oiimion of tbei»e ebcmieally aiinloLn>us sjiILh, Ivut animonUim 
]>fi<is]dnite f NH^)JII*()^j is ot^teu used in prefrrem^e); white 
Imriiiia byiln>^^eii |diuHjdxatt\ BalU'O^, ih prwijiilated, mm]- 
iiblf in pure water, Init sli^^btly s«duble in a<iu*^<*us stdulioup 
of ^>nie salts, and readily ?*<dulde even in aet»tic ami (Jther 
weak aeidi*. To anotlier jiortiori a^ld artHUoninin oxalate* 
(NHj )j(M_J^ ; white barium oxalale, Hiv('^t)^, i^ prt'ei|ritale<K 
miliilile in ililute mineral acids, and sjiarins^dy so in acelie 
aeid. liariuni wilts» moistened with bydrm Idorie a*'id, impart 
a greeninh n>h^r to a Buiisen fianie or ^ipirit-lanip flame. 

.\frtnnnin*fttm. — -(tood practice will 1m^ found tii wriling out 
ei]Uatiiais t^i reprej^.'iit eiteh of tlie forcp»inj! reaeliou**. 

Antidotrg, — hi cjumth ufiJoiHiiriing by t<ioluble hnriiiui snItA, iihvtoiin 




STRONTIUAf, 



111 



antidotes would be solution of alum or of siieh tftilphates as tho«e 
of magnesium (Ep^om ^ah) and sndiinn (Olauber^d salt)* 



QUESTIONS AND EXERCISES, 

What i» the valency cii* bsinum? — Write the ftirmulse of harioiii uxiile, 
hytUttKitUN I liloridtv iiitriil** and !5ul|>h;iLo ; atid .state huw tiio substuticis 
jure pr<-|»«n'd. — Di^riW thr |tre|iiamtiiiri of hydrnKrii iMTnxifk%— Whiili 
of llic wsU for kiriiim are utuat cbanitterirttic?— Uivti LH|uat)<>us fur lliu 
rriAttttdiiH.— 'Name t\m miluhjlii^ iu cases of piiisontug hy s^iLublt) bttriuiu 
fittlUaud cjxpjiiiu Its itctiuu. 



STEONTIUM: Sr Atomic weighi, 8694. 

fOreiirratrr^ — Stniritintn njinjioniid.s are not idxindant in nature; 
I the I'lirboniito, SrCi ).^» known jlh »frtffftinfiift\ und tlie j^uljvliHte, 
4rSC>j, knc»wn tis crlfj^tinr (frnin fvr/wm, tiie sky, in liHusiou t-o it« 
occ4i«ioiiHl IdiiiHli «'<»l<»r), are by no nii'uns rare iitint'talH, 

^SftJ/s of Sfroufittiit are iioca.H5*mally eniiil<>y*:'d in medicine, tlje 
folUtwing being official in tb<* Unikd Stati\s rbaniianpjMeia: — 
Sfrontii Bromitlnm, HrUr,,*ni,i ); Sfrwifii Mldttm, HrI^,ljllJ); 
Sirontii SallcytfH*^ i^T{V^\l^^l^) fill, yh Tlu' C(Map«anid,s of this 
metal are, bowi»ver, cbieHy untd l»y lirnw<»rk inanufartnri^i^ in 
pri'|Miririj5 **red fire." Strontium hydroxide, lik^ bitriuai liy* 
droxide, \f> rnntdi um'rJ in i^tifjar- re fining. Strontium naltH iinjiart 
a frimsan coU»r to tho Jla(nt\ Strontium nitrat*", Sr(N()^\. it* the 
tnoNt i^uitahle Htruntium nidt to uh^ in makinfj pyroteclinic iidxtnrt^, 
its oxyjren caut*(n|r vifrorons r<Jinbit,stion when the salt is mixed 
with rliiirt-oal, snliduir, et^:., and heated. Thiw sidt niity i>e 
obliiified by iii^^olvin^ the carbonate in nitrie aeid; a inethtid 
whirh is apfirnpriate fur the |>rej»ariVtion cff other strontium salts 
if the ecjrresjtondinjr aeids are eaifjloyed. Strontinni ^alts may 
aUf* he prepanMl from the eheaper stmnti uu> snlphate, SrSO^, by 
»tmnjrly heating this with earhon to eon vert it into snlphiiU*, SrH, 
ariil itien di^tfilvin^ the latter in the aiijtropriate aeids. Stn^ntinm 
nuljdiate is verj' itparinffly sohibh* in water 

Anulyiii'al Rvm'twn>^ of St mat him SuH^. 

1. To a ^dution of strontium nitnite or ebloride add 
amnioniuin earlxmate; a white iireeipiliite of strontinni ear- 
l>oi)iite, HKHl^, is [iroduetHl. 

2. To n jwdution of a jstnintiiini salt add bijjhly dilute snl- 
phurte aeid. or an e^|iinlly ililute .^dution of any sulphate 
(that ofi.*«Kd urn, for example ); a while preeipitate of i^trtnillnm 
Nillphatis Hr8<\, in pnxiueeiL The formal ion id' this preeipi^ 



112 



THE METALLIC EADICAL& 



tate is promoU^d by stirrin;^: ami Uy laettipg the Jirjui*! a^ulc 
for s4mK* time. { Biiriitni wilts^ ^ivr an innuctiiate precipitate 
iiijiler siiiiilar eireMiiii?t{ineej5i. i 

o. To a ililute M>hitiou ut" a i«tr<»iitiimi salt aild jn^tassitnii 
chnnuate ; no prtH*i|iitate is pnnjiured uiilef*&? the mixture is 
alio Weil to AiHul far some time, or is iK>ileiL 

n:iniim aiJiy Ik* ^separated t'roai the Htroatiuta hy menn** of 
[totassiuai ehniaLMte, tliii^ reu^rint at onee iireeijiitatia^ hariiuii 
IVina nr|auaaH or ai'*4ie mad HoliitaaiK The value of the reartion 
Ls raehaiieed iTaeetie arid la' amruoniaai ue*'tate In* pnsint, f<inai- 
tima < linaaate being Ikr aa^ru f^olable ia siicli Hiiids th:*.n in Wiitrr 
(Kimsum). it \ti al.Ho more »<duble in eold tlian ia b<4 snIytioa«. 

4. Mnisten the end t>f a platinum wire with i\ stdutimi <«f a 
strontium .silt tmd hold it hi the JimiKeu llariie; u eriiiiKiai 
eolnr is impurte*! to tlie Haiue. 

Other Analytical Reactions. — Alkali-mt4al jdioxjdiatt-s and 
oxalates j^jve white insohihle preei|alate?f witli ^^troutium sjilt^ 
iLH with barium (atid alscj with C4ik'iunij mil^. 



CALCIUM : Ca, Atomir weight, 39.8* 

Occurrence, etc, — Calcium eoaipoundfi form a large proportion 
of tlie eruBt of lair earth. Calcium earhoaate is aiet with ns chalk, 
marlili\ liiaej*t<aa% eale-npar, ete. ; the Md}>hate iisn jfy[>suia iirid 
idabiistiT; the nilieate in niaay aitJaTjds; calcium fiuoridc iv^ tlaor- 
i^piir. The jdUMphnte h also a riaaiami mineral. IMa.'^tt'r-of-Paris, 
{i'tifrii Sttfphft^ Kn^irf^tihijt^ U.S. P.), is gyjmum tVinri which the 
water of crystal liwttion ha** lH>cn driven siwii>' hy heating lo n 
teaiperatare of dull Rvlness. The element itself is only is«dutcd 
with great difR« ulty. It** melting point i;^ 7Ci<)^ C. ; it^ «p. gr 
LK5at 15,5'' V. \ 

Calcium Chloride. 

Experiment 1. Tom>me hy<ipHddi»rie aeid add ealcium ear- 
bomite (Chalk, or the purer form, while marble )» CaiT)^, 
until etfervt*i*eenee ceaise^ ; filter; s^dution of ealeiuni chluride, 
CttCl^, tt euinmoii soluble ealeiuni wait is formed. 



OaCo, 


4 21101 =- 


CaCl, ^ 


}Ln 


^ CO, 


('Allium 


HydTHjchloric 


rntcium 


WhIiT 


rnrlKinJe 


curl Mj III! te 


luid 


rhkifidc 




AiihyflHik' 



This s<dution may l»e olitjiiui^d ijnitj' neutral by well bmliiig 
beOtn' filtering off the exeess of marble, 

hndutiai of calcium eliUiride evap<»t^n»d t-n a svnipy i'taiMiKt^^nce 



iALnuM, n:\ 

yi^ldn m'sUls (G}iCI,,*jH./)). Thest? ftre i^xtri'itiely deliijiieii^eeut. 
Tilt' «<)lutiori, I'vaporateii U^ Aryuvni^j Jtmi tlu* white residue ln^iik^rl 
Ui i\\mnilM\T F. (20<PC. ), t^ive^ H)liti ri*k'iurii uhlrtride, CuCl^, 
211, <>j in 11 jMiriiUK fiirrn. Tliv n-r^iilting liini]»ii sire ii»eti fordryiuji; 
gM?it*s iiiitl for tVceing certain lit|uid>^ rn>iM wutiT. By fusi^jii at a, 
low red heat the anhydrous ehloride CaCl,, {^Oihii Chioridum^ 
U. H. I\), irt jirndiieud. Calcium ehhiriile Is Sidtihle in ale^du^L 

Marble often ccnitiiins ferruus e^irljouate, FeCOj^^ whieh in 
the sibove [jrocess heconies converted into ferrous chloride, 
reiMleriuj^ the ea lei urn unpure : — 

FeC(\ r 2HCI - Fetll, 4' H,0 4- CO, 
FcrpMis llydrcH'hlrtrk* Fcrnma WAter Carbrmic- 

CArbuiuiKi ucld chlr^rido auhy«lride 

If pure caldiim chloride he reqnireil, a few dro[ia of tlie 
j*<>lulion i»houltl be pjured into ix tesL-tulK* or beaker, dilnled 
witli water, and examiueii for iron (by aihbng aniinuninm 
bydrosnlphide, wliiith ^i%''e?< a bbiek preeipilate with iron 
t*nlL*^^ and if the lattt-r ii^« {jresent, eabinni hy[joehlorite (in 
the form of cldorinaled lime) innlshiked lime shotild be added 
to the rorniiinder of the li<jnid, iind llit^ whole boiled ibr a 
few minutes. The irim ia precipitated aa ferric hydroxide, 
and is filtered ofl': — 

4FeCl, ^ Cap*)), f 4Ca(OH\, f lUfi =4Fe(0H), f-r)CaCl, 
Ferrous Calrliim Ch lei ion Wiittr Frrri(^ rnHuni 

cbiurhl^ !*ypocbl(irit« hydroxide hydroxide i-ldMride 

The solutioti of calcium ehloride mt obtained may contain 
«inue calcium cblorate. On adding excei« of ammonium car- 
bonate anil heating ^entl}% then washing the precipitate 
thoroughly with hot water {t^ee p, 114) and redifti^olving it 
in hydnx'hloric acid, a pure solution of ealeium (diloride may 
be oil tallied, 

Tbii^ proeewa may lie imitate*! on the j^mall scale after 
addiu!^ a minute pie<*e of irmi to a fraunient of the nuirlde 
before di?«tdving in acid. 

Calcium l^roniide, i Cafrn Bromititau, V, S, W), is also 
uffieiaL 

Calcium Oxide. Quicklime. Caustic Lime. 

Experiment 2, — I'lare a small piece i»f chalk in a ^Irong 
lire or ruriiace, ami beat until a fnigmeut, chii>[)ed oft* and 
ciKjItil, does not ertervesco ou the addition of iicid ; Hme, CaO, 
( Calx, U, 8, r. ), remains. 



lU THE METALLIC RADICALS. 

CaCO, = Ca*) h CO, 
Ciileiuin Calcium CiirlKjnic 

carbuuate (ehitlk) uiclde i^liui«) niUiydriile 

Limc'liins. — (in a large R-alc the nhuve (JiH-mtion b furried 
oil ill wliiit lire t^ruied (ime-Jtilfis (kUn, iiaxon, ctjln^ Trum rtjtvnr^ 

Calcium Hydromde* Slaked Lime. 

Experiments.^ — When the (|ui(^kliuie prejmrpil \n the j>re- 
oeding experirutiiit us (;(>!< I, a<itl to it nlx>nt half its weiji^lil of 
water, and notice the cvolutitui vd* stuiuu and the other 
eyiflenc^ of eoergetic eheniiral lu'tion; tht^ product is fh^keil 
linK^t caluiuin hydroxide, <'a(On ), with whiUevtT sliLdit 
n a t u ral i ni pu r i t len the 1 1 in e may t ■< ► 1 1 ta in. T lie ^i 1 ii k i 1 1^^ of h an I 
ur "stony" lime 01 ay be act^leniied l»y using hoi wat^jr. 

CaO + H,t) = Ca{(H{), 
Lime Water Ciikiiim hydroxiilv 

Lime-Water^ riart* the rnlciu ill hyilroxidti ( wa>'h( d with 
a litth' wittrr lo rt'inuve trari's of ntdnlih:} Baits) in iihoul a 
hundred times itji vveijj^ht of water^ and shake frc<{uently; 
in a tshorl lime a ftiiturcHl solution* known a« lunv-tnttrrt 
(Liquor CalciA^ U. 8. P0> re«yk,^. It contains ahout 13 
grains of ealduni hyflroxide^ Ca(()H),, e<|yivalcnt to nliout 
in ^niim of linie. (('adj. In one jmint at 00^ h\ {l^J^b'^V,}, 
At hi|u'her temperatures less is dksolveil. 

Sdfrharnttif Stjittion of Limr. — SltikiMj lime is* am<:h nj<>re 
?wjlnhle in aqueous >iolutioii of HU^iir than in pare vviiten Synip 
iiflioie, (S)/ruptf« rb/r/jf, l\ »S. 1\), is MUch a stjlutiuii. It iH a 
more efllrjent preripitaat of hydrnxidoB, carbonates, and phos- 
pbatea than Hme-wuter* 

Sohitions of ealiiuin hydroxide ah^irh rjirliijaic aidiyilride i»a 
exposure to air, 11 tieiai-crvstalline precipitjitc of cah-iaiu earh"»n' 
jit«' Ik^in^ depoHitt^L When the hjo elitinitt d solutinn U bejitod, 
there in preeipitatefl a coni]M(und C(»nsistinjj uf three aiok'eidea of 
liaiiMvkh niie <d supir. \Vhe« it in freely exiKiwed to air, iixy- 
gea is abi^rbetl, and the }*i>lutiun heeouies colored. 

Calcium Carbonate. 

Experiment 4. — To a solution of ealeiuuj chloride a<Ul ©xeew 
of^oiiium ciirlKinate, or alMJut 1^^ partnofthe eiirbonale to 5 
of the aiibydroiiij <*hloride ; a vvlnte precipitate of cah*ium car- 
bouate, CaCO^ (Calcit Varhonu^ Pracipikdin*, {]. S. P.), is 



CALCIUM, 



115 



produced. If 1;he solution of the salts be heated before admix- 
ture, and the whole be set aside for a short time, the particles 
assume a finely granular or slightly crystalline character to 
a greater extent than when cold water is used. 

CaCl, -f NaCO, = CaCOj + 2NaCl 
Calcium Sodium Calcium Sodium 

chloride carbonate carbonate chloride 

Collect and purify this so-called Precipitated Calcium Car- 
bonate, by pouring the mixture into a filter-paper supported by 
a funnel, and when the liquid has passed through the filter, 
pour water over the precipitate three or four times, until the 
whole of the sodium chloride is washed away. This operation 
is termed vxishing a precipitate. When dried by aid of a 
wetter-bath (p. 118) or other means, the precipitiite is ready for 
4iae. It is not only somewhat purer than the average samples 
''"^^halk or "prejjared chalk" (see p. 117), but it is 
, ' . ""MH^jrate, and on account of its physical charac- 

' • . •^a constituent of dentifrices. 



' (from bibOy I drink), is simply 

the best white rags — white blot- 

' ly good quality. Students* or ana- 

ect precipitates, are circular pieces 

irom three to six inches in diameter, 

Fig. 24. 




Construction of paper filters. 



twice folded (6, c), and then opened out so as to form a hollow 
cone (d). The cone is supiwrted by a glass or earthenware i'un- 
nel. Square pieces of filter- paper should be rounded by scissors 
offer twice folding. If this is not done, angular portions of the 
paf>er project above the liquid in tlie filter, and if a spirituous or 
other volatile liquid is being passed througli such a jiapcr, much 
of the liquid will be wasted by evaporation from tlie unneccssjirily 
large Kurface exposed. 

Paper filters of large size are aj)t to break at tlie point of the 
cone. This may be prevented, and the rate of filtration much 
accelerated, by supporting tlie paper cone in a cone of muslin. 



H<] 



THE M ETA LUC nADICALS, 



Fte. 2&. 



Wftuh-hoiilr. — Preciiritiites are lj<?«t wa>4!iecl In^ means of a fine 
jot of water directctl <>i» to the di^lennit parts of the filter. A 
common tmrnm-neeke^J hf»ttle, of siliout hjilf-jtitit iiipiifity, is 
htt4."<J with a fork; tvvr^ hijIcK nrr htired thr<iiigh 
the v<»rk, the *»iie for a )i;1iIhs tii he which reaehe** 
to I he botU^jn of the hotth' mid is ht-iit exter- 
milly to j» wUglit liiuti? ati>rle, the other for a 
tube bent tit 11 .slightly 'jbtiiw* Miigle, the inner 
arm termirmtiiig jiLst iiiside the brittle. The 
outer ami?* may bealKHit three inehes in length. 
The extretnity of the outer arm i»f tlie louder 
tul>e j^hould Ik- (>rt'V loudly ♦kfivvii out t*i a fine 
cjipilliiry oi)enirigby holding the original tube 
(before bending) in a tiiinu% ami, when soft, 
slowly pnlling the two ends apart from each 
other until the j«jftem'<l jK*rtiim is reduced to 
the iliameter of a knitting-needle. The lube 
is now cut at the narrow jmrt by means of a file, and the i*harp 
edge rtiimde^l off l>y [daeiiig it in a flaine for a second or two. 
The oul<r extremity cjf the s^horter tube Khould alnri be rounded 
off ill the fiame. TheapparaKiM l>eingpnt together and the bottle 
nearly fille<l with water, air from the lung^, hliiwii through the 
nlmrt tube, forces water out in a fine stream at the capillary orifice. 
For a hot'iraftr umsk-botth- {V\^. 2o) the tubes and curk are fitted 
to A fl^L^k which may be heateil over a Dunst^a burner or im a 
wsilerdiath (p. 1 IH). Fine twine wontid closely ar«nHid the iieek of 
the fla.sk f«irm^ a i*uitable mm-comlueting protection for the hand 
of the operator 




Hol-vraCer wftfiU- 
bottlu. 



Fig. 26. 



Pio.27. 



Fm,28. 




DecAntatlon. 



T>criintaiion» 



Hl^ibon in Action. 



Demnfatlon, — rreei|ijtia*»« may also he wiwht*<l by allowing 
them topettle, pouring ofl'the supernatant ru|uid (Fig. 2ii\ agitating 
with water, again allowing to «eltle, and ik> on. This i« waobing 




CALLiUM. 



117 



by lUennffiHon Uh^ from; cant km j an edge). If the streani of 
(itjuid exhibib^ miy IlthUmk y to run down \lw tmier side of the 
Vi^Hel during di'iantiUinii^ it should he guidt'd hy a iz\mH rod 
placed agaitifit tlK- |M»iiit uiuri^ the xtiTam einerj^es (Fi^, 27). 

If thir ve!*sel Ih* too hirge lo haiulle with iMUivenieiiee, the ti^juid 
ojuy 1k" dfiiwn ofl'hy iiieaii^ of a j*iphon, ilh h1h>wii in Fig, 2H. 

Prt" pared chalk, {fhita iVfrjmrnfH, U. S. P.),, is merely washed 
chalk or trhifift^, hut in phaniiaey, fashion dfuiands that tlieihalk 
Im? in little fonkal [uui|>h, about the si/.e of thinihleH, instead uf 
in thff larger rt*lb ehiiraeleristk* ofwliitiag. Its pcmder b a»i<ir- 
phuiiH. 

If either the precipitAtetl caleiuin earbonate, or the preimred 
chalk, eonlainB aluniinii, magTiei*hitn «ults, irnn oxide, or phos- 
pbateA, itpt j4olution in aeifl, evaptiralrfl to drynes.^, and redi:<Hi>lvi'd 
in water, will yield a preiifatiite of hydroxides or pho^iJ^hat«^^^ on 
the addition of synip of lime. 



Oaldtmi Phospliate. 

Experiment 5. — ^Dlgest hone-ash (bcmej? hurnt in an (jpen 
cmeihltt with free aeeess of uir until all animal and earlM> 
liaf*e<iU8 matter has hei'u renio%'ed, and a re,shhie of ini[>ure 
c^ahnuiii pliosphale is left), with twiee iti^ wei^dit id' hydro- 
chloric acid (diluted with four linjes its voliinu' of wuter) iu 
a test-tul^e or lar^'er veaael ; the phosphate l& discjolved* 



Ca,(PO,), 


-H* 4HC1 = 


C;lHjH(),), 


-H 


2CaCl, 


rntoliuu 


Ilydrot hloric 


Add nilrium 




CatHtim 


pKoophiile 


rtCJ.l 


ptH>H|jhAte 




t'hluri<ie 



Dilute the solution with water, boil, filler, and when cold, 
add excess of anunonia s<dution ; the caleiuuj phosphate, now 
practically ptire, ( Calcii Phoi<phfiJ< Pra'cipitfiht.% V. 8. P.)* is 
re precipitated as a light white amorphous [xwder. After 
Well wn*shing, the precijiitate shtjuhl he dried over a water' 
bath (i*ee p, llK), or at a teinj>erature uot exceeding 212° F. 
(100*^ C0» to prevent undue aggregation i>f the partielej^. 

raHj(PO,)^ -I 2CaC1, -h 4NH, = Ca,(PiJ,). + 4NH.il 

Acid cnk'ium rAlcIum Ammonia Calcium Ammonium 

pti(«|thatiT cUloriilt? pboepbntc ehlurltje 

Bone^aith or Imne-mrfh contains small quantities of calcium car- 
bonate and Kulphide, These are deroTa]><i»iM in the above pHweas 
by the acid, eah-ium chloride being formed; on boiling the mix- 
turet carbonic anhydride and hydrogen sulfdiide are cvolvivL Any 
ciirbaiiaceoUH or silieeou^^ matter, etc., Ik removed hy filtration. 
In hf*ric*, the calcium phof*j)hftle in always acernnpauied hy a winall 
€|iiantity of an allied HubHtHniM% nrngnf^iuai phos[*hate, wbjrlj ia 



118 THE METALUa RADICALS. 

not n'lnove I hy the procoss fk»Hcnl»ed above, Ik>ne-aah alsn cott- 
Uiitiw fi Irsire *it (*jilriuin thumilc, VwF^, 

Culiiuth |ihftspliiitt" irf ^erirmUy jiri'imri'il hy the hiteractioii ot^ 
ealeiiuTi ehl^iritle, sodjuai i»h()sp|iiik% aud ajiiitmnia, the renulting 
[jft^^ijiitjiLe ht'iiig wa^lied with e<»hl water. 

I'aleiuHi Hy(jt)ph(»8phU<% {Valeii Hypophoi^phU^ U. S. P.), is 
oificial. ♦ 

A Wfifcr-iiitth for the fvaporati»»n *if liquids or lor dryinjr nioiat 
B<jlidsat a temjjerature helow 212^ F. (HHt^C), is an ik>n, tin, or 
earthenware pun, tlie mouth of whieh can he narrowed hy iron or 
tin diaphra^nis of various size.s »o ii^ to adapt it t^i the diameters 
ijIbuMinM or platens. (Sr^ Fig. 18, p. 7(i), In the British Fhanna- 
eopR'ia, "when a irntvr-ba/h ii* directed to he iiM*d, it is to be 
nnderst*K>d that thii^ term refern to aiiapparatiLnby mefmsofwhieli 
water or its vapor, at a temperature not eRceeding 21 2*^ F, 
(KK)'' 0,), is api*lied to the outer surface oi* a vessel containing 
the suhstaaee to l>e heated, whieh wubstanee may tlius be **ub- 
jeeted Uy a heat near to, bat neeessjirily tK?low, tliat of 212'' F, 
( 100** (A ), ^ ' Evaporation irt vacuo is performed by simply placing 
the vessel of liquid r^ver, or hy the side of, a small vessel contain- 
ing eoneentratcd sulphuric aei*l or other ah«orhent of moktiire^ on 
the jdate of an air-puiup, covering with a capacious glass hood or 
**reeeiver/' and exhausting. 

Saditim Phmphaie. — Ordinar}' eodium phosphate, Na,HPr\, 
1211^0, (Sod it Pfwf*j)haj<, V. S, P.), i» prepared from calcium 
phosphate as followB :— Mix in a mortar, 3 ounees of ground 
iMaie-eartb with 1 tluidiKmct; of .Hulpburic acid; iset aside for 
twenty-four hours to alhiw the interiiction to take [dace; add 
alxjut 3 ounces of water and put in a warm place for two 
davH^ a little waroi water li€*iug ad<led to make up for that 
Itist hy evaporation ; i?tir in anotber A ou rices of water, wami 
the whole tor a short time, filter, and wash the residual cal- 
cium rtulphale on the filter iti or*Ier to remove ad be ring acid 
calcium phoj^pbate; amceutrate the fiUratc (L e,, the liquid 
whicli hiij* pa8.«ed through the lilter), to aliout 3 ounet^s, and 
filter again if necessary. To the hot sfdution, which eon- 
tains acid calcium phosphate, add st>lution of RHlinni carUm- 
ate (preparated from about 4 J ounces of the cr}^stailized6aUj 
until a precipitate (eahnum hydrogen phoHphate^ CaHPO^) no 
longer forms, and tiie liquid is faintly alkaline; filter, evafio- 
rate, and net aside to crystiillize. The foJ lowing equations 8ht»w 
the two deiHmijko&itions which n<H*ur during the operations: — 

CX(PO.), f 21180, - CafI,(P<\), ^ 2CaSO, 

(T.Jil^'itnn dulpnuric Adi/'Alclum CjUctntn 

{khOMphiitv ftctil phfMpliAte tiilphate 




Aritl ciklcliiui i^tnliimi Sodium 

[»hos|ihat« carhouiite pIumplmtL' 



119 

f IT,0 + CO, I CaHPO, 
Water €Ar(wnjic Cftlrium 
aiihyrlrldo hy4roijt.'a 

Sfidium phf>sphate eryatalliKes in tmnsparcntcolorleais mondclinic 
prirtins, efflorefwx'nt^ having an alkaline reaction and a «Miline tiiate. 
One part in ten of water constitutes ''Sodium PhoHpbate Tt^t 
li»lution/' U. 8, P, The cryatala effloresce rapidly in the air 
ntil nearly half the water has escaped, and a salt ia obtained 
rhii'h hiLs a f>ennaTient composiitiim represented by the ftinnulaj 
"JtL^Ui'O^, 7H./h Anolhfir scKliuin phosphate {sodium dihydrcigen 
phosjihate), Naif J*Oj, H.^O, k obuiined by niixin|T aolutiona of 
pliortphoric aeid and t^iKliuni larbunate in the right proi^MirtiouB, 
evaporutiog the mixcMi solution and setting it aside to cryatalliswj. 

Oalcinm Hypochlorite. 

Experiment 6. — Pass chlorin<3, generated from black man- 
j^anese oxide and hyrlrocblorie acid» wi already de^ribed, 
liver damped slaked lime contained in a piece of wide tubing, 
outlet end of which is conuecled with a tube leadiog into a 
futne*cuplioard* The product C!hlonnated Lime, ( Culx 
Vhlorinala^ U, 8. P.), is ordinary hleachinff-powder^ a com- 
_Niund of calcium bypffcblorite an<! chloride, mixed with a 
rpiautity of unchanged calcium hydroxide. It is commonly, 
but impnjpcriy, r^allcd rhhride of lime, and is one of the 
ttost efficient of known dtHitifectaQts. 



MnO, -h 4HC1 = MnCl, 

lllack man- Hyrlruchlorln MungAnotiji 

ff«nc4e oxfde iw\d rhlarlde 

jjcxotr), + 2a, = 2H,o 

Oftldum Cbtortno Water 
tiydrosldo 



+ 



2H,0 

Water 



+ 01, 
Chlorine 



+ CaCl,0„ CaCl, 
raid urn Cftlf^tum 



Chlorinate*! lime exposid to air and moisture, as in di uninfecting 

Ui<* atmottphere of siek-roomt*, slowly yields hypo^.^hlorus ai-id, 

rHCU)^ calcium carlKinatc Inking formrtl at the wune time. Free 

^liyfWHTlilonia acid «oon breakK up into water, f^hloric acid, HC'lOj, 

ikn*\ fre*} chlorine. Chloric acid im als<> unstable, decomposing 

inU> oxygt^n, chlorine, water and perchloric acid, HCIO^. The 

dll quantity of hypochlonn^ acid difTiined thmugh an apartment 

"when bleaching- powder is expof^ed, thus yields fourteen -fifteenths 

of itji chlorine in the form of chh>rine gft». 

fhn*iiintion of b/t'tiehing-powdo'. — ^Treated with alcohol, blemh- 

|liig-pr»wd«^r dfH*s not yield it^ calcium chloridi? to the solvent ; 

rbrtjce the* powdfr ii^ not a mere mixture of calcium chJoridi* and 

hyfjMiclilorite : water, altvo does not diaiolve out first one salt and 





120 



THE METALLIC KADICALS, 



then the other, but together, in the nuiltHuIar proportions of the 
funnuk, p, 119. On tlie (ithtT hjiiid, when thtMwjuenUH snliition 
is conled, or evaiH*r«tr<l in ranm^ tTVHtaU ore tjbtaineit wlruji 
Kingzett has shuwn to hv nearly [mre calriuin hyjuK-hliiriU', the 
Bolutioii contitining caltium eliluricie. Whik' Iht* former fat-t 
indicuten that tlie powrler is a i caajxiunrj nm\ nai a mere mixture, 
the latter iudicatew lJi:it it is a feeble conipoumi — an adhesion of 
nioleeules of hypochlorite and ehloride, an shown in the equation, 
rather than any ehiHi*r or more intimate couibinati^m of ntonis. 
If it he regjirdeil as a single rath(T than a duuhle Kidt, then 
the following formidti (Odlin|^) luav be employed, CiiOClj, or 

*^^ ( (.10 

Bleaching-liquor, — Digest chlorinated lime* in water, in 
whieh the bleaching eonipjintd is st)lulde. Filter fnnn up- 
diRsolved lime, ete., and toM the bleadiing [Kiwen* of the elear 
liquid by adding a few dr«»]j(S to a doem^tiou of logwo^jd 
slightly acidulated. 

ErperimeBt 7. — Mix a little ixm-dered wo<kI eliar**oiil with 
three or four timers Ub weight of gypiuii, and heat to redness 
in a erurihie. Borne of the caleiuiu &«ulphate is red need to 
sulphide, CaS, with produetion of earbonie anhydride antl ear- 
honie oxide. If the prwiiict eon tains not less than Oil |>er- 
eeut. of eiikniim sulphide, it is the official Sulphurated Lime 
{Calx Sidphuntfa, II S. P.). 

Official ttist.-^lf 1 ffTn, In- mixed with a eold iwdution of 2.08 
Gm. of cupric Hul[dirtte in r»0 euhie centimetreas of wat-ur; and, 
after Ihe addition of a little hydrochlorie acid, the mixture he well 
stirred and heated on a waterd>uth until all action hiL^ eeaineil and 
then filtered, the filtrate should give no e<dor on addition id' ex- 
eL*w of anmionia water {presence of at Icaat 60 percent, of pure 
ealeium sidphide). 

The explanation ot" the mode of this tcwt is as follows : — CUiprie 
wulphateand calcium hulphide intenict in the presenceof the iwid, 
giving insoluble cupric sulphide aud calciuui sulpluite, thus : — 
CuSO, 4 (;:u^= CuS 4 ( *iu*^0,. 

On adding up the atomic weights or the constituent elements 
of erysta!lizeil cupric nulphatc, 247.^*5 will V»e found to \h* ihe 
fonnula weight ; while t 'aS w^ill similarly reprej^t^nt 71.53 partw. 
Ak 247*85 is to 71.()8, so (approximnlely) is 14 to 4, But *>niy 
half of the sulphurated lime is calcium sulphide ; tlierefon' 8 grains 
of wieh sulphurated lime will interact with 14 ai' rupric sulphate* 
If the 8 gniins are below the stated .strength, then they w ill not 
attack the whole of the 14 grains of eupric S4ilt, and, in that 
ammonia water (or pobLssium ferrocyanide) will reveal topper iii 
the filtered liquid. 



CALCIUM. 121 

Calcium Gummate. 

Cnlrium GummnJr is thr oirty Mflirial fiikiuin salt that ri_'UJiiiti?< 
tf> bt* iic*Uc<h1. Thirt €(Mii|niiirMl is, in KJiort, <trnbtit, tht- <»r(Uniiry 
CJum Acada or (lUin Arable {Acncmj V. K P.). A t^olution at' 
gutn ambic in water yields a wliitc^ i>ret'ipitatr of lalriutu <»xaliitt^ 
ou the additi^ni of solution! of ajiimoiiiuiii 4ixahit*v; <»r u p'lvve of 
guru iiu'inerat4Hi in a porcelain LTucihle yieltk ai L-aleariHuis reaidne* 
which, when tlissolved in a dilute add, ailVirds cbnraeteriHtic 
reaction« with ntiy of the iinnlytkal U'sh< for calcium HaU."*, de- 
scribed further on. In ^ome .speciiiM^nrfof gnm arahic a jj4>rtion of 
Ibe c^ilcium i» displaced by an equivalent quantity of pot^is>iiuui or 
niii^Ui>i4iun). The ^uniniic or arable radical nuiy be precipitated 
as opaijue gdatinou-i leud ^ainmiale by the addition of a 8obitioii of 
lead subacetatt* to an iw^ueoun solution of guuL These Btalenients 
Khoutd be verified by ex peri men t. Mitrifaf^o Acacia^ U. 8. P-.^ia 
a f*c»liition of acacia in water and lime water. 

Trngatanih [TragamHtho, U. 8. P.), i^ a nuxture of Koluble 
arabiuoid guju and a variety of caleinm gum, iuHoIuble in water, 
leruied haanttrin. With water and j^lyeerin a gelatinous mudlage 
i** farmed {Mucilago TrotjiWitnthu^ IT. S. P.). 

Calcium Carbide. 

Calcium carbide is of iutere^t chiefly on ac< ount of the eapy 
metbml of pre|>aring acetylene which it.s iuteractioTi wilb 
water affords. It tnay Ih^ obtained by subjeetlug au infuuate 
mixture of mleiuui oxide and cnrlioii to the exceedingly^ high 
Utnif»erature of tbe electric funiaee. The carbide has the 
c<>ni|^»oeitkm CaCy atid is usually met with as a fused homo- 
giHieiius black mass, althougli when tjuite pure it m colorless 
and traoBparent. Water rapidly denmij30se.s it, with the evo- 
lution of almost perfe*!tly pure aeetylene. Dilute acids behave 
in the mme way as water; (wuccutruted nitric and Butphuric 
acids attack it hut slightly. 

Analytical Reaviion of Calciam Salts, 

I. Add dilute supburic acid to a solutirm of a calcium salt 
ojuuitiei] in a test-tube or ><mnll teHt-ghus,s ; n precipitate of 
calcium sulphate, C'aBO;, i» formed if the s(dutiou is pot Uk) 
dilute. Tbe ailcium is tiot com|)lelely preei|iit4ited asynlpbalet 
be^^auM* this salt, uidike barium sulphate, i^ quite appreciably 
ipoluble in water. The addition of jwdution of calcium sulphate 
to a solution of an other calcium j^alt does not produce a precipi- 
tate even on standing for gome tinie or ou boiling. (Compare 
the Iwhavior of barium and of strontium salts). 



122 THE METAL! Jfl RADICALS. 

Soluiimi of (Mlcium Sulphate.— Th^* oHicml Caloiuiu HwlphaU^ 
Tt'^t Sulutiiijv, IJ, S. r,, j.s a saluraU'tJ wiliition iiinl t'lmlaiiiH one 
jirtrt ot'ailfiiini wulphaU" iu 378 jmrts of wiiter. 

2. Add fxjtjiasium ehroniate, K^(X>^» to i\ mlwXmw of a 
calcium salt slightly aciditied with aci^tic acid; tio [irefipiUite 
18 produced even on etaudiiig or ou boiling* (Coinjiare the 
hehavior of barium and atrtjotium salts.) 

Thf«€ hm reacfion^ are moBt valurtblo in aixa!ysis, i\» evt^ry prt*- 
*"j|>iliuit of calcium is also a prcci|jitiiiit <*f biu'iuin and of titroaliain; 
but in Uilutc .solntions, calchnn tiulphatc tiihI (in ftreHi-uci^ of acetic 
acid I, jJ0t4ii«inin chroniate are jirctijiiunLs of bariuui onlv. 

Other Analytical Reactions, — To rejwirate pordoiis of a 
solution of a calcium sjilt, add amnitmium cjirlnmate, f?odium 
phos[ibatc mid iinnniHMum oxiibitc. l*rt:cipitute.s are obtaiiie<l 
w b iv h vi >rr c?i ^a \ [id i n a | ) |>eji rai i cf t u t lmt*c [ i n h I u vei I in the ease 
of a solution of a barium salt; thf^ir <H>mjM»^ilion it* nlfM> 
analogous, hence their c*nTect forninl:D can ea.sily be deduced 
and e^juations written to reprei^ent the actions which take 
place. ( )f the precipitnuta jnsst mentioued, aiimiooinm oxalate 
is the one ujo^tt commordy used ns a reagent for cjileiuru ?allH 
iu the aln-^encc of Itarium. Calcmm oxalate is infioluble in 
aeetie, bnt S(»hn4e in hydrochloric or nitric aci<ls. C'nlciuui 
conn>ouuds impart a reddish <^3lor to the Bunseu tlaiue. 



QUESTIONS AND EXEECI8E8. 



Writ* • pftraprapli wx HirmWrnm. lis iiutTinil erinnjMHindm ehi'mieal re- 
lAtioiM, Icehnk-al iiiJ|)Ueatiori,s nnd tests.— En iitni^raU* »mnc nf the i^ntii- 
mon iiJitural fijmpouudj* of calcium.— li*»p resent hy ftn equaticm Ibts m-- 
t ill II ijf hydmchlnrk* arkl cm mfirblf.— Why is calHiitn chloridii used as » 
desii'catinir ngont for Kasos?— tliiw woiilfl yon purify Calciom Chloride 
whkli has been nmdr from ferniKinoiis niarhit??— <iiv<* diHgnims,— Write 
a few tinea oa chomwtry of the lime-kiln,— What occurs whi'ii liin*' is 
*'«liiked"?— To what extent is limt »ohib!c in water i Liquor OtWt, 
U. H. PJ: and in Synip iSyrupuM Cniriji, IT. S» P. )?— THiM^ribe the TirrpAratiofi 
of the oflicml ProcipiUte*! Oiletniu (^arlKmate iCalvii Cnrhoiutji /V«rri;*f- 
IntHti. U. JS. P.); luiwdc»-H it diflVr frrun Pn'parvd (^bnlk ((Yrta Prvparntn, 
U. 8. P.)? — How diK'S fi1tcr-ixi.|»er ditfiT from othi't kinds of jwpcrl*— Eic- 
pluin the construction of a ^^warfj-lmttle,"— Dfrtnc ihenntiUi0H,—HUitv the 
fllrti'rence tM*tw»M^n bone-ash and diJcii PhoffphaA PrtrcipUnint. — Ilnw is 
'* bone-earth " purified fur use in tiiedieine?— Hive equations showiiuj the 
conversion of Cnlrimn PhoHphfiti^ into >vidiimi Phosphate,— Write a ?hori 
nrtielu on the mutiutW ture coni|)(iHUiim« »iol u?*t,s of *'bl*^Hchi(ii;-powiler'' 
ifhfr ChiftriTiatn, U. S. P.I.— Tloff* may calcium be detected in f«um 
Arabic?- Slalr tt»e ehemi<*al nntiire of Trapiejuitb. — To what extrnt ie 
calcium «nlphrtte wluble in wat4»r?— BjiHunj \w\nfL abrii-tit^ wl»at reajn^nta 
fiiay Im* u»e<l for the deteciii»ti of cidcinm ?— WbJeh \s the ebief It^l? 



rflH 




Atnmic Wei*?ht, 24.18. 

OtTHrrewy*^ efe. — Magm^imu is jiUumbint in uiituro in \hr ftirm 
of miigm»Hian or iiinuntaiii liiiicstoiii', Icnmil ihlnmitt' (nftfr Dnlo- 
nnru, a ge«*lt»gi!'t), a double miiji^nrsiiun and calciiiin ciirbouiite, 
iti very common u.^i* its a buildin^-stoni% and mnifnm(ff\ a t^der- 
aldy pure nuignemmii carbonatt'. tlioiijrh Unt *'sk*uy*^ for direct 
ii!H' in medicini% eveo it" very finely [nrndered. Mugnesium t^hhi- 
ride and magni.^ium sulphate ^K[>s<jm salt) t>eeur in the water of 
many ?<prifigH, and magiiertinni sails also oecnr in st^a water and 
impart to it its liitter tiLste. A hydrous suljdnitt% MgS(*^,H^(), 
t4«rnied l*i€4teriU\ ih-cutk uear Btasslurt, in I*ru.H,^ia. Metallie uuig- 
ne:*inm may bi' obtiiiiie*! fntni the rhloride hy .strongly heating it 
with w^idium. Tht^ metiil burns rettdily in Ihi' air, I'lintting a daz- 
itling light due to the white heat to whieli the resulting (mrticlej* 
of niagnejiia^ ^Ig<>, are raised, Thi' ehlnride t<» l>e enijiloyed liB 
a Njuix-e of the metal h obtiuned by disr^ilving the earlxniati* in 
hydroehloricaeid, adding aninumiuni ehloridt', evaporating to dry- 
nci^, heating the re:iidne in a cfeej^ vessel (oa the small seale, a 
large t<\st-tiii>e or Hask), until the ammonium ehloride is all v<datil- 
ized, and the magnt*i>iuni chhiririe remains as a elear fused litjuitL 
The latter is ponre*! upon a eleai\ c-artheuware 8lab, The amm*** 
nium chloride is added in orders* preveiil the interaction of mag- 
ni***ium chhiride imd water which would otherwise take place in 
the last stagf*ft of the operati*>n, with formation of maguesiuiii 
oxide (or oxychloride) and hydroehlorie aeid. 

Magnesium Sulphate. 
Experiment 1. — To a few dro]>H of dilute sulphnrie neid in a 
ti*l-tul»e, add exee?^ of |M)wdered Dative magnesium car- 
bcmftt^, mnfjnrmte^ MgCO^, and boil until ef!erveseen**e cefts<« 
mid ihe carbonic nnhydride has been completely ex]M*lled. 
The filleretl lu|iii4 is a wdutiou of magntVnnn suipbsite, 
eryslali* of which, Epmm mlt MtrSO^, 7H/^ ( Maguemli 
Stifphfiii, U. S. P,), may be obtaint^d on boiling off* most of 
the water, and .lettiuL'^ the concent ruled .solution aiside to eooL 
This iJi an ordinary nra nn fact u ring" pr*K"esa, Instead of mag- 
ni'site, dolomite may be employ chI, any ii*<^iti being: removeci 
by evttjwiraling the solution lo «lrvnef*.s (afler filtering from 
the i-aleiuin Pul|diate pnxluced ), gently igniting to dee<nnpise 
ferrous sulphate, diaRolving in water, iiltering from ferric 
fiitide, and rryHtallizing. If neither minenil be at baiul, the 
student may use a little of the ortliuary magnesium carbonale 
iim*i\ iti pharniaey. 



MgC!(), + U^i\ = 


^rg80, 4- 


H,0 + CO, 


'MiMcnmltc** Sulphnnc 


Miiim«'<iiiiTi 


Water r«rlMirilr» 


acUl 


iiulphiUc 


«nhy "Iridic 




]'U 



THE METALLIC nADfCALS. 



Magnesium sulphate* (Tystallizes in largf coJorleAM, trjirirtjuirent, 
rlninibie jjrisinH; Iml, thnu vauvvnlniied siilutioiis, tlK' frysl^ils j*re 
d(*]Mi*?itt'd ill slu>rt, thin lu't'dles^ ti furtu iimro ei>ijvfnii'nt lor 
JiuiriifMihiUoii, wihitiiiii, ;iml ^I'lUTiil um* in rnrdiriue. The crystiil- 
Vi'/M HJilt IfwcH tJIlj) when hiakMJ to :jOO^ F, (aliiiut IfiO'^Cl.). 

IriJii uiity he tk^UH'tnl in nuigiii'^uini wul|ihu!i' by luhliri^ a hcjIu- 
tii*n of chlorine U'd Hint' or chlonniittnl stnUi to uJi smjiu'ous solution 
cjf'thtvtydt ; lirowii fiTric! hydroxide^ Fe(OH)3, is thru [»recipitiited. 
Aniniouiuni hydroriul|jhiiie will iil:^ give a Idai'k prtfinitiite if 
iron he prei^ent. 

ICffervesetnt Mfiffnmum Sutphaie {Mmfnem Sftfphan Effervt^rem, 
V, S. P.), ij^ niaj^nesintn wuliduite drml tvn a watrr-baH* uatil it 
mi lunger lo?*i's wti^ht, and tfii^n mixed with citric and tartttric 
iicid?^ and j^odinni bicarbonate, and irranuhUed, 



Magnesium Carbonates. 

Experiment 2. — To j4ijluiii>n of magnesiimi sulphate add 
solution of Hodiunj ciiri>oiuUe iumI boil; the res^ultinj^f predpi- 
tiit4^ is majjrit^ium airJ>onate { Miignrttn i^arhmta^, U* S. P* ). 
a white, partly amorphous, pi^rtly minutely cTystalliiie mag- 
oei^ium iiydroxyenrhonale, apjiroximntely 4Mg<'()j, Mg< <*H )^, 
6M„*). A denser, sli^^htly jLTramdnr preei|*itate of similar 
chemiral eoni|Kisition is tibtained by mixing eon<^enlnited 
M»Uition8 of tlie aboye salls^ evaporating' to dryness then 
removing; tlie sodium snlphate by dige,^ting the residue in hot 
wider* Hlteriiig, washing, and drying the precipitate. 

MiMrnet-tiim 8oflmm Wulor Otlk'lul ma^nit^i^iuiii Sortluin t'lirlnmir 

AUlphutc t'ttrt>on*ite ^iirlxmate sulphali anliydride 

The proportion?* for t!ie preparation of the carbonate are 10 
part.H of aiagnet^iuni sulphjite and *y\ of mr»noIiydriitcd Kxiiuni car- 
bonate, eaeh diviolved in Mf> of eojd vvater^ the s<*lutions mixed, 
boiled for lo minutes, the precipitate collected on a filler, well 
wju^hed, dniined, an<l dricil at a tcui|>erature not exceeding 2}2^F. 
(HH>°C.). The heavier carbonate is made with the Kiunc ]irojMir- 
lionftt<'i* of miih, ea<'h disseilved in 20 part^ instead of SO t»f water, 
the mixture evaporateti fjtiite to ilrynt-8s, mid the rc^sidue digesUHj 
in water and washed until mII s^odium j^ulpbate h removed I until 
a white pretipitate of hariuoj *«ul(>hate is no h«i^^er formed tm ihe 
addition of ^rdution of barium chloride (»r nitrate to a little of 
the filtrate). 

Amtthrr Promut { Pattimon' »), — Considerahle qmin titles of mag* 
neMium earh(>n?tte are j^n-pared by treating dotomite (p. 123) with 
earfHrnic un hydride nnder pressure. The niaj^^nesiunv curbormte 
diseMtlve^ before the calcium carlwmattN and is then pn^cipitatetl 



MAayESWAf. 125 

fr<nn tlie clear S4»lutl<in by treatment with steiim. (Compare next 
experiment, ) 

Experiment 3. — Pass I'ltrlxHiitT anliv<lridej geiieralerl as dea- 
criU'il fin p. 7fl, into a niixture of water unci niagnes^iuni wir- 
honate trontiiim-d in a test-tniie. After some time, sepjirate 
any uiiclissolvetl carhoiiate by tilteniti<ui; llui tiltrate contains 
magnesium carlM>tmie dissolvefl in carbmiic acid. A «*jlntion 
containing about 10 grainn of ojffidid carbonate iu one ounce, 
is knoWD as "Fluid Magnesia.'* 

The aolution h made from freshly prepared carbonate. The 
hittor \fi obtaineii by adriing^ a Lot Niliiliun of 2 tmnces of mtig- 
nesjum sul[ihatc in a half a i>int of water to one of IJ ouneen of 
mntiohydrated f*odium Larbouute ia anotht^r half pint of water, 
lK>jl!ng the mixture for a «lmrt time (to ctanplete di composition), 
ftlteriag, thoroughly wa.shing the jireeipitatc, placing the latter 
ill I |dnl of distilled water, anil IraUMmiUing citrhoaie anhydride 
through the liquid (ssay, at the rate of thnn? or bulible?* per seci^nd), 
for an hour t*T two, leaving the .solution in contact with the gas 
under pre.ssure of abimt three ataiosphert'M for Iwenty-ftmr hours, 
arnl, Hnally, decanting from undissolved carbonate; then, utter 
pa*<8ing in a little airire gun, ke^^piag ia a well-eloHed bottle, 
f^light preK'^nre in be-^t produced by |dacin^ the carbonate and 
water in a iKjttle fitted with a cork an<l tubi^ as for a wasti-boltle 
(|i. 1 l*i), conveying the ^^an by the tul»e which reache!> to the 
biittoai, and allowing ex<.'eKs of gaw to flow out by the njiper tube, 
the outlet end of which is cnntiniifcl tu the Iwitt^im of a huuxH 
bottle in which mert-ury, to the de|>th of about im iach, ha^i fjeen 
plaet'd. The Ivtttb^ should he b>osely phi^'^ed with cotton wool, 
id prevent h>ss of metJil by spurting during the piu^siige of the gas 
tlirtaigh it. (Each ini4i in depth of mercury tliron^di which the 
giu* eHcai>ei^ com^fwunls to ahrmt half a p<mnd pressure on ever)" 
fttjuare inch of surface within the niipuratus. ) 

He^t a portion nf the Kfdution: hydroUM magnesium carbonate, 
MgCOj, 3H,f), is prccipitatcii, A sjdt havinjr the same cr*mp*»si- 
tion is depOHjted in cryMtal?< hy tbe siMmtane^uiH evaporaliim »if the 
rtidutiun. Un exfjosiirc to cold, the snlutiou ,'vimetimeH alfonls 
larg"e thick crystals ( Mg< -t J^,r>M,jt>), which, in the air, lose water, 
lHV«>nie opa<pic, aivil ibi-n bavt* the compi>sition of th(J«e deposited 
by evaporation, (MgUU,, :ill^U). 

Magnednm Oxide. Magnesia. 

Hjcperiment 4, — Heat nuigtiesinm earlMumte in a jioreelain 
crucible ovi'r a lamp (or iu a larger earthen crucible in a fur- 
nace) till it cea^^eij to effervesce on adding a dilute acid to a 



Mi 



126 THE METALLIC RADICALS, 

small portion ; the residue is magnesia, MgO (^Magnesii Oxi- 
dum, U. S. P. ). The i^ame oi)eration ou the heavy carbonate 
yields heavy niagnesia, MgO {Magncsii Oxidum Ponderottum, 
U. 8. P.). Both are sometimes called calcined magnesia. A 
given weight of the official magnesia occupies three and one-half 
times the bulk of the same weight of heavy magnesia. 

4MgC03, Mg(OH),, 5H,0 = 5MgO + OH,0 -f 4C0, 
Olllcial mai^usium Magnesium Water Carbonic 

carbonate oxide anhydride 

Magnesium oxide becomes hydroxide in water, slowly at 
60° F., rapidly at 212° F*. A trace only of hydroxide is dis- 
solved. Moisten some magnesia with water, and place the 
paste on red litmus-pai)er; the wet spot, after a time, becomes 
blue, showing that the hydroxide is slightly soluble. The 
oxide is liable to Ixjcome hydroxy-carbonate on exposure to 
moist air. 

The official solution of Magnesium Citrate (Liquor Mafjncsii 
Citraiu) is made by dissolving magnesium carl>onatc in solution 
of citric acid, adding the filtered solution to syruj) of citric acid, 
contidned in an aerated water-bottle, diluting, adding poUissium 
bicarbonate, stoppering the bottle, and shaking cKTasionally until 
the potassium bicarbonate is dissolved. The formula magnesium 
citrate deposited from solution is Mg^fC^HjO,).^, 14HjO. 

Analytical Reactions of Magnesinin SalfJi. 

1. Add soluticm of ammonia or of ammonium carbonate to 
a solution of a magnesium salt (sulphate, for example), and 
warm the mixture in a test-tulw; the precipitation of j>art 
only of the magnesium (as hydroxide, MgfOH)^, or carbonate, 
MgCOj occurs. A<ld now to a small jwrtion of the mixture 
of precipitate and liquid a considenible excess of solution of 
ammonium chloride; the precipitate is dissolved. 

It is very necessary to note the solubility of inapiesium hydn)xide 
and carbonate in solution of ammonium chloride, as important 
analytical s<'parations of majrnesiuin from other metallic radicals 
defM'iid upon it. In analytical pnictice, the anniionium chloride 
should be added before the aininonia or tiu> a nnn on ium carbonate, 
as it is ot\«*n easier to [)revent j)recipitation than to redissolve a 
precipitate once formed. 

2. To some of the soluticm obtained in the prece<ling reac- 
tion, add solution of so<lium or ammonium phosphate; a white 
granular precipitate of ammonium magnesium phosphate, 
^'H^MgPO^, is produccnl. 



QUALITATIVE ANALYSIS, 



127 



3. To another portion of the same solution add ammonium 
arsenate; a white precipitate of ammonium magnesium arsen- 
ate, NH^MgAsO , is produced, which is similar in ap|)earance 
to the corresponding phosphate. 

Xote. — Barium, strontium and calcium are al»o precipitated 
by alkali-metal phosphates and arsenates. The other precipitants 
of magnesium are also prccipitants of barium, strontium and cal- 
cium. Hence the analyst always removes any barium, strontium, 
or calcium by an alkali-metal carbonate, as above indicated; 
sodium phosphate (or ammonium arsenate or phosphate) then 
becomes a very delicate test for the presence of magnesium. In 
speaking of magnesium tests, the absence of barium, strontium, 
and calcium salts is to be understood. 



DIRECTIONS FOE APPLYING THE FOEEGOING ANALYTICAL REAC- 
TIONS TO THE ANALYSIS OF AN AQUEOUS SOLUTION OF A 
SALT OF ONE OF THE METALS, BARIUM, STRONTIUM, CAL- 
CIUM, MAGNESIUM. 

To a portion of the solution add ammonium chloride, ammonia 
water (until the liquid, after shaking, smells of ammonia), and 
ammonium carbonate. 



A white precinitate \» produced. Acidulate an- 
other portion of tlie original solution with acetic acid, 
ami add |>ota.ssium chromate. ^ 

An immediate 
yellow precipi- 
tate indicates 



Ba 



No immediate precipitate is 
formed. To another portion of 
the original solution ada calcium 
sulphate. 



A white pre- 
cipitate,formed 
on standing for 
some time, or 
on hoiling, in- 
dicates 

Sr 



No precipitate 
even on stand- 
ing or on boil- 
ing, indicates 



Ca 



Confirm Ba, Sr, or C^a ^y flame-test. 



No precipitate 
is produced. To 
the same por- 
tion add ammo- 
nium phosphate. 
A white crystal- 
line precipitate 
produced either 
at once, or on 
standing for 
some time indi- 
cates 

Mg 



I Potaflsium bichromate must not be used in those operations, or 
a portion of the barium will remain in tho liquid and be precipitated 
along with, or in the place of, tho calcium carbonate, (sec p. 110). The 
potoAsi urn chromate used mast not contain carbonate, or calcium will 
be pre^ripitated along with, or in the place of, barium. (The absence 
of carbrmat« may be proved by the non-occurrence of effervescence on 
tbp addition of hydrochloric acid to a little of the solution of the chro- 
mate, previously made hot in a test-tube.) 



12fJ 77/;^ METALLIC ILlIflCALS, 

snjall portion j the resjilue is magnesia^ MgO ( Magnemi Oxi- 
ihim, U, S« P.). Thf «iime ujMrTatioD on the ht^iivy rarhonati" 
yields heavy iiuu^iie.HiH, M^K ) ( MtujntMl Oxlthnn Pottdero^um^ 
U. H. P.). Holh luv MUiietimt'i^ rullrd faldued rua^aiesia, A 
given weight oi' the uJ^hi-isil magucsia uccupies thrkic and oiie-hait" 
limes the hulk of the aamQ weight q1" heavy maguesiu. 

^MgtX),, Mg(OH)^ 6H,0 = 5M|!rO -f 6II,() -j- 4C0, 

Ofllcial timgneAium Mngnci^iiim Water Cnrbonic 

carboDiite oxide ttiitaydriiJc 

Magnesium oxide heoomes hydroxide \n water, (*lowly at 
60° F., rapitUy at 212^^ F. A trace only of hydroxide is di*- 
iinjlved. Moisten some nuii,'ne«ia with water, and phice the 
paste on red lilmus-|)a|>er; the wet &p>t. after a time, U*eome#i 
lilue^ showing that the hydroxide is slirj^htly 8olul)te. The 
oxide i« liable to become hydroxy-earboiiate on exposure to 
tiioi.st air. 

The official «olution of Magnesium Citrate (Ugtior Matjnmi 
(HfraftJ*) h made l»y dissolving magnrsinin liirbonsitt' in solution 
of citric acid, addia^ the tiltered s<>hition to syrap of citrie aehl, 
contiined in an aeritted wiiter-buttli% dihiting, adilin"' potit.ssium 
biearhonat^, t«to(>pering the bottle, iind shaking ^K'aisionjdly until 
the potiixssinm biearhonate is dissoh*'d, Tlie torniulii itiagnesium 
citrate deposited from 8*jlation is Mg^iO^II^t).),, 141Ip. 

Analytical Eeaetiom uf Magufmum Salts, 

1< Add s<dution of ammonia or of ammonium carbonate U* 
a 8*>Uitioii of a magnesium salt (sulphate, for example K and 
warm the mixture in a te*?t4uli<^; the |ireeipitntior» of [)urt 
only of the magnetsium i a^ hydroxide, Mg( t)H ) „ or earUmate, 
MgCO^) oecurt*. Add now to a small portion of the mixture 
of precipitate and lirjuid a considerable exetjss of solution of 
ammonium chloride; the precipitate is dissolved. 

It is verj' neeesaarj* t*^ note the noluhility of magnesium hydn>xicle 
and iiirhonate in soluti«m of ammonium chloride, a^ iuip«trtunt 
analyticjd !M'|»arHtioiis of niiifrnesiiini from either metalJic radicals 
deiteiid upon it. In amdyticjd pnwtice, the iimuionium chloride 
shonhl he added hiforc the iinHoonia or thtMmiriioniuni c«rl»omit*, 
m it is •►tten ca^iir to prevent precipitiitioa than to «' dissolve ii 
preeipitate tmee fonned. 

2. To some of the solution obtained in the preceding reac- 
tion, add 8<dutioii of smiium oranimontum [diogphate; a white 
granular precipitate of anunoniuni magnesium phospbate* 
NlI^MgPO^, is produced. 




q UALITA Tt Vh' A SA L 1 SlS, 



127 



3i To another portion <»i' tlie s^jiint' Hdlulion mid iiiiinnmiyii\ 
arseimte: h white jirt'ri|jitate of iiniTnuniiHii ninjLrrie.^niiii ursuii- 
jitc, NH^MgAsO, is pruduivth which b< simiJiir in iippearmice 
to the eurrtispomrmg phosphate, 

AV*-,— Biinurn, strontium mitl cah'iinii jire alsn precijtitatefl 
hy iilkttli-iiietal jihoHphatei* and arseniik^. Tlir oth< r preti]>itjinls 
of niii^ue?*iuni are also preciintants of hariuia, stnmtiunt :inil fal- 
Huiu. Hence thi.^ analyst always rt'irinvt?.-? any harinni, strontiuni, 
or t'idciitiH by an alkali-aK't^il curhonate, jls above iiiditated; 
0O(Huiii pliMSjdiiite (or iiminoniiim arsenate or phos<[diate) then 
liecoincs u very delicut-e test tor the preseiii'o of jHnjLrnesium. Jii 
spcsiking of niiignesiuru toi^ts, the ahsenee of barium, sLroutiuin, 
jtDd c;klcium ia^U \^ to l>t* unden^tood. 



PIKECTtOSS FOU APPLYING THE FOREGOlNrt ANALYTICAL K£AC- 
TIUXH TO THE ANALYSIS OF AN At^UEOUS ROLUTION OF A 
8A LT OF ONE OF THE METALS, BARLIJM, STRONTILTAI, CAL- 
CIDM, MAtiNE*^IU5L 

To a portitm urthe s«iliition add anniiraiiuni ddoridf% junmonia 
water ♦until the lic]uid, afttT sliaking, smt^Ils el' anunnnia), and 
oinni oni uiu ca rl m » na te. 



A while prtripilnte is proihieed, 
otbc^r nortion otuiv oripnal witulion 
Hrni add ]H(ta.^iu]ii ebronmte. ^ 



Ati tnimedijite 
yvUdw p rvcii pi- 
ta k* indicut«s 



No iuiaitHbale 
formttl. T<> am 
ide onprniul ^)liU 
8alplinte, 

A white prt^ | 
cipitiite^foriiiett 
on Ktaadrn^ for 
wmie tiaie, or 
iin JN_«ilin^, iu- 
diciUes 

8r 



Acidubite an- 
wilh acetic neid, 

precipitJUe is 
•tber pnrticinof 
ion (idd aik-iuiii 

Xo precipiiHte 
even t>n **t«tiid- 
in^ or iia Uiib 
injtr^ iadicati*» 

Co 



Ccntfimi Ik, Sr, or Clu By flame^aiL 



No pivi'ipiLnte 
w pnxliieeu. To 
the slune |x»r- 
tion nild jinmio 
tn am phfksphatt^. 
A whiti' en'Hial- 
liiitr iirei-ipUale 
pHMlucvd either 
:it im*M, or oil 
H I a n fl i n i; for 
scant* tniie kidi- 
eatt^ 



* PutaMttiiim liichrooirtti^ innst not \w nwd ia these tipimtmns, or 
ft jwiplion of thfj bsihaai will rt^main in the liquiil aarl 1h* i»ri'ripitiil*Hl 
Ml' Mf in rhi' phu'o of. the nikium curlmnate, m^i p. HO), Tlie 

!»' iirmiinir tiMtil iiitlMt not eoitinin euHKunite. or raleiuni will 

»■ i**^!)! ttloan with, or ifii the f*taro uf, ImHuar (The ab^MH'o 

II < may he provf'tl l»y the Tioti-fK'<'yrri"iic"t' tif i'irervcse«uf« ou 

IIm rt orhyiln»€hh»ne ai'iil lou littU* of iJu.' lialution of th« chro- 

tnAtc, prcvioudy mado liot in a Uu)t'tabi.\) 



r 




128 



THE METALLIC RADICALS, 



Precipitate, 
BftCO,, SrCX>,, Oia )j 
Dinotve oii the filter in dilute nitric 
flcicl; evaimnite I he dilution to dryne**; 
dieest the residue in a mixture of et[iml 
▼oliuues of alcohol and etEier ; filter. 



Filtmk, 

Add aninumiuiii pli(»«[diale, 
allow to ^tnud for Hja\c lime, 
and filter. 



Raifinr, 

Bft(XOj,and 81 XO^,- 
Wash milh nirKtiire of 
alcohol and ethvr, di«- 
«td%'e in water, add 
dilitle act'tJc acid, and 
then KjCH)^ ; filter. 



PtxcipiiaU, 

Ye How, 
formed 
immedi* 

ately 

indit-ates 

Ba 



FiUrait, 
Add 

(NH.UCO, 
tiUafknliiie. 

A white 
jiret'ipilale 
indicates 



Fdtratt^ 

Contains 

CaiNC»;»s 
, Exfiel the 

alcohol and 
^ ether hy 
I genttyhcat- 
' ing on a 

water-liath. 
; I>i»(otve the 

rtfsidue in 

water, and 

add 

A white 
|>recij>jtale 
indicate 



f onfimi Ba* J^r, or Ca bv cli»*oh*in^ 
thi' II;i( H V SH'Oj, or CaC^O^ in HCl. 
and applying the flanie-test. 



Precipiiate. 

While cn->5- 

tzilling 

indicates 
Mg 



Filttnte^ 

I ft ) Boil a iM»r- 
li(m. A white 
prei*ipitatc in- 
d i e ales Li. 
Contirm Li. 
bv iliinie-tef«t- 
<^) Test for K 
by the bi«t- 
ninth thio«ul- 
phate test (p. 
8JJ and fool- 
note p. jCH>». 
(c) Test for 
Na by ^luine^ 
lest. ' 

Test for NH^ 
in the urijfi- 
niil ^Intion 
by boiling 
with ^Klrnrn 
hy d ro xide. 
Smell of am- 
monia indl* 
cate# 



Note L — The analyst of Hcilutions containing the forefffiinff 
lUL^tiiU is ccnntiicnced l>y the aildition ofaninioniuiii chloride aiul 
ammonia, hi m ply ai* ?i precautionary inca^uro, the former coinptuind 
preventing partial precipitation of magrie,Hiun». the latter neutral- 
iJiiii^ acida. The ammonium cHrbmate is ihe bariuni group p re- 
el pi tan t 



TABLE or BUORT DIRBTTIONS FOR Al»PLYI>-0 THE FOBfiOOINO 
ANALYTICAL EEACTlOXeS TO THK AXALY&ilS OF AN AQUEOl'^ 
SOLUTION' OF fciALTii COXTAiyiNC* A>'Y PR ALL OF THK j 

MBTALLIC RA1>ICAL£ HITHERTO CONtiir>ER£D, 

To a {K>rtion of the solution add ammonium chloride, ammonin 
water (until the liquid, after ghakiug, icmelU of ammoniaj^ aud 
ammoniiun carbomite. Warm and filter. 




DISr/LLATWy. 



129 



I 



Note 2, — tn the preeeiiin^^, mid in fiulit*t'i]Ui;TiL Uibli's of analyli- 
ail pnx'eescs, the let*<lhig precipitiinla will \m fuuiid |4> Xw mu- 
uionrum ssaltii. Tbest% lieiiig volatile, can he gdt rid af ttivsanl 
tlie crui of tlie oixEvrntiouH^ and thus the detection of potassinm sind 
iM>dium ia in no way itreveiited — an advantage whkdi would be 
loj*t if such suite as jJoUiiiiiiiun eurbonute or sodium photiphate were 
the group prei^ipitauu em [Moved, 

Note on Ciassificaiion. — The eump<JUtidH or barium, Btroiitiuin, 
caleium and magtieiiiuiHj have many analogies*; their carbonates, 
phosphate and arneiiateH are insoluble in water, which siiffieienlly 
dii^tinguinbes them from the nieJiibert* of the ^roup of alkali-metalM. 
The w>hibility of their hydroxides in wati^T murks their eonneetinn 
with the alkali-metals; the t^lightne^is of that ndubility, diininirih- 
ing as we advance farther aad farther from the atkali-metjil!* 
(baryta being most and magne^sia Icii-st aokiblc in water) pr^inh* to 
their eunnection with the next cliLss of metals, the hydroxides of 
wbieb are insoluble in water. These considerationH must not, 
b o w e ve r, be < i ve r* val ii ed . Thon ^Ii the sf > 1 u hi 1 i ty o f th e i r h y d rf > x i d es 
lAacea barium nearest an«i magnesium fartheat frum the alkali- 
nietak, the wdubility of their sulphates gives them the opposit^? 
order, niagnefiium sulphate being most aoluble, ealeima sul|>liate 
next, filrontium sulphate third, while liariuai milphate is practi- 
cal! ly inHolubU* ia water. The elemeDtsare &<mie times described as 
the metaU qf the alkaline etiHh. 



QUEHTIONS AND EXERCISES, 

NJimfi the nutuml smjrecfi of the vnrious niiiRin'sium salts, — Oire n 
proe«^* for the prepanition of EfMsom salt,— Omw dia^jnims iiJustnitivtr 
of f h«» furniation of iiiagncHiimi fial[»hate from mnmrJilie riud from dokfuniff. 
— In mftffncsia milublr in water?— How is "Fliiiri Ma^MHsiji ' propariid? - 
Mention the elTectn of heat aiicl rold no 'Fluid Mnpnesiji". — Ant rrtuin 
hi»w mach mngne^ra ;MgO)e.Hn W obtained from im gi-jiiiis of Kpsom 
ftfttt—OilcalAtc the amount of ofTlcml Mfl^rifMium Carbonate which will 
r\eh\ 1(W> (rraiuH of luajtiiPMH — Can maprie.siion be drtt^et^d to pTrM«-nw 
uf liAriuf]], strantiani. or rjilcium? — I)e.*4<'ribo tbe uoalysiw of un Hi|ueotm 
liquid (*ot»tainio)£ «alt« of bariuiu, stnmtiuni, calcium aud uiatin'""*'*!"' — 
Ifow may uiagncaium be precipitated froaisolutiuuscoutaining auiUKoiiiiin 
nlt«? 



DtKTILLATIOX, 



The urat^r with which, in aimlysi^, flolution of a salt or dilution 

of a Htiuid i»* eifiH-ted should 1h* pure. Well- and river-waters are 

unfit f*>r the purpo}*<% biH^ause they contiiin disw>lve<l sidt^ u* the 

\ asUnil i»f Home 2i^ to i\{) grains or iitorv per gallon, derived fnMti the 



\ 



y-' 




130 



THE METALLIC RADICALS, 



mi] through which the water jierL-olfite^ ; arnl niin-wnter in not in- 
fre<]iiently contaiiiiiiuled with tli*^ (hint aiiil tUhti* vvhirh fiiJl ou iho 
r^Kifi* vvlu^iit'e it U usually c oIhcii(L Such vviittT if* jiurified by 
di«fi(ltilttm^ iiri o|«i'rtitioji in which the WMter is, by hoiliiijj;, rori* 
verted into steimi and thi* ^teaui condeniiuil aij^aiii t^o water in a 
Hcpanile vesnel, the tixe*! salts remamiri^ in the veM.sid in whieh 
the water is b«»iled. iJri tlie lar^re seale, the boiling' is earried r>ri 
in nietnl boihrs titted with a IhkkI or head in which there is a 
wide lateral ehuiniel tlinai^h wineh tlie steam l1as!H*^^; on the8ini»ll 
ttrule, either a eafinium ^his.s tla.sk is cirijtliiVLHi, iiitu the neek of 
whieh 11 ^diLHs mbe, bent to ini itente ang^le, is littetl by means of a 
cork; ur a rttort is ustd {^jt. Fig. 21*), a species of long-necked 



Fki. 2d. 




Pintill'itLon, on email scnkv 



ftimk, bent nejir the body, by the glsiJsH-worker^ to an apprtipriate 
angle (hence the name rrfort^ fmin rrtitrtjurH^ 1 Ijciid hack), dm- 
drnAfifion irt elfeeted Ivy hUrniUnding the outlet Uihe through whieh 
the stianj pa^^wes, with cf>ld water In large stills the steam-tuhe, 
or cmidrn^tntf^mt/nn^ 18 usaully a metal (I in) ]>ipe, eoiled into a 
B|dnil form for the sake of eojn|jat'tne7<s, ami so fixe<l in a tul>e 
that a few inches of <ine end of the [>jjie may ]»ass through and 
closely ht a hnle Ixired near the iKittinn of the tidi. Cold water 
is kept in cnnlati with the exterior td" the pipe, provision being 
mafic for a continuous ^np|dy tfi the bottom, while the lighter 
water, heated by the comleTising >team, niris off fmui the top of 
the tub. The condenser iitted to a ilask or retort may lie n simple 
gla8H tube i>f any size, pJaet^l within a nmch wider tube (a e«an- 
mon longj narrow lam p-p hiss may arrs^wer thr experiTueutid opera- 
alions), the inner tube bcin^ tUted to the wi<ler one hy nirans of 
lM>red et»rks ; a stream of water pas#<es in at one end tjf the enclosed 
space (the end farthest fr'Hti the retort), Ihrnn^'^h asinall glasH tiilte 
inst-rtt^l in the cork, and out at the other vm] throu^di a similar 

tube. The common (Liebig's) form of laboratory i denser \^ » 

glaa9 tube from one-half to three-fourths of an inch wide and a 



II 




I 



zjya 131 

yjiril k>n^ (A, Fij;. 2*>), r.(irriiunflL-«l hy xm imtcr tube {^'•, Fi^, 20) 
iioinewbat nhurttT urnj al»oiU two iru'lien in (tiaineter, hnviri^ at 
each exirojniiy a neck, thnmirh which I he inner ^ha^ tube [ntsse^. 
The junetifHis of tlie mit<T tube with the inner lulie are iimiJe hy 
iiie«ns of ghort, wicie IiKliU'ruhher tMt>e8 (f/ and t\ Fi^. 29 ), An 
inlc't (/, Fig, 29) near the* l«*wer jifirt uf ihe outer tube provider 
for th<» adiuisHion of a lurrent of eold water, eonveyed hy India- 
rubber tuhiiijr, while ^%v otitlet nejir the toji {tj^ Fi;^^ 20) alhnvwthe 
oscape of heated wat-er iiit<i the miik. The inner tnbe may tlm>4 
li€ kcpl eonst«nUy wurromuied hy eold water, and heated vnporH 
ptifiRing thrr>ugh it may lie jierfeetly cooled and eondeuHed, and 
eoJleeted iti a receiver (A, Fig. 29), 

In dintilling funeral gallons of water for analytiea! or medicinal 
ptirpnrtt-ps {Atpia DUtUhtln^ U. S, P,), the (\t^i two or three jdritH 
«lionld Ik? rejeet*»d, became*! they are likely to contain truceji of 
Ammonia and other volatile impurities. 

Pure water in not found in nature ; natural wat4?r always* con- 
tains Home solid niatt<*r in wdution, and also disi^olved giuset*. The 
junount and kind of matter held in ^^olution vary with the 84juree 
of the water, WaU^r ined for distillation should not contain any 
Lar)fe amount of impuritiea, but should be auch aa ia Ufiiia.lly sup- 
plied to large townx, 

RrttiJkai'ujH in the procesH of re<lij*tilUng a dintilled litjuid, 
Itfctified sjtirit is a spirit of wine which hm^ been thus treated. 

Prif or d€»triittivr diMilfafkm in distillation in which the ixtn- 
denned products are directly Conned hy thi? decoai pawing influence 
of the heat applieil to the dry or non- volatile ^4llh^tilnce^4 in the re- 
tort or fttill, as* in the distillation of ctial in the manufacture of 

cool gHfl. 

—Write freiui itu^uuir}' ii short ilt'f*i*ri[*iii»n Ki[ dUt'Ulatwn, 



At fhU utagf the stmlent U a*jti4n recommmtied fo rmd the pnrn' 
fjnfpfts on thr tjrntral pritwiplfM nf chrmienl philmffphtf ( ptiffrx ^9 fn 
69)^ find to return to than from time to ftnif, until thrtf art thoroughly 
rornprrhendrd. 

ZINC : Zn. Afomicj weight, 64,9. 

Orturrrtiet, Wc.-^Zinc is loUr.nhly ahumlant in nature as* suK 
phid(% ZiiK, hlrndt\ and (^arbonate, Za<*l\, mlnmiur (from rtilo- 
mH», II rt-ed, in alluMiioi t«» the appenmnee of the minend). The 
«in5w an? remitted lo exffcl ^uliduir, carbonic ardiydride, and worae 
impurities, and the riHidtint; uxide its heated with charcoal, when 
the mrtal %'apori/e8 antl cnndi-nwi'M on cooling. Zinc is a brittle 
tnet^U ^"^ at a t«^mfKTature j^taiiewhat below JJOU^^F. (148.^®CJ, 
It U riiJilleabk*, and may he ndled into thin sheols. Above 400^ 



JM 



A 



i:J2 




TUt: MKTAUJV HADICALS. 



(204.4*C\), »t IB ii^tun brittle, imd iiniv then he |iiilvi'Ti/.€ii. It 
(iielt>^ at 77"i''F. (41!.7''C,), ami it* vt^huiio at a hrijrht ml heat. 
Zinc in txci'iitiooally tint* powtler igiijtt*s s[MirjtiuuMiijsly, es|n.H"ially 
if dairipj or if" «t«rod in a warm plac«\ 

rWvf. — The iiJveH of zinc as a metal are iuipirtant; alloyed with 
copper and nirkel it yieltU < Tertiian silver; with twice itj* weight 
of cojijier it forniH hrjiMti^ and as a eoatiiig i>n in^Ji (tlie wi-calJed 
tjaivfiniztd iriHi) greatly retiir*is the fonnatina of rust. Mfwt of 
ttic milti* of 7Jnc are prepared, tiireetly or iiuiireetly, from nietailie 
zine (Zincktm, U. 8, P,). 

MuifeuitiT Formula, — 8<Jine remarks on this point will be nmde 
under 51ercury« 



Zinc Sulphate. 



Experiment 1. — He-at zinc (4 purls) with writer (20 parts) 
artil .sulphuric acicl {){ fluid parts) in a te«t4uh€ (Hr larger 
vessel) until no more hydrogen is evolved; solutiou of zinc 
i*ulphiite re.sult^. Filter (to *e|vanite the particles of leail, 
earlxm^ etc., present iti ordinary xinc), aod concentrate the 
solution m an evaporating-di:^h; on cooling, colorlei« prkmatic 
ciygtals of Ziue 8td[)bate, ZtiS0^,7H^0 (Zinci Sulpfta*t 
U. H. P/) arc deposited. 




Zn 
Zinc 



4- H^SO, 

Sulphuric iLCid 



= ZnS<>, 
Kincsulphiite 



+ 



Hyilrogi'n 



The sulphuric acid used in this experiment must be diluted 
with a considerable quantity of water, as ab<jvc. Culd con- 
centrated Bulpbtiric acid does uot attack zitic. 

Note. — Of several methods of prepariag hydrogen, the one jast 
dcHcribed is the rntitst convenient ; of the two or three means of 
preparing zinc sulphate, it is that mo**t oonmionly em|jloved; and 
of the many reactJoii» which may be utilijWMl for ohtuiniag a cur- 
rent of eleetricity, it is one of the most convenient. The apparatiLH 
in which the reaction is affected ditTers according to the require- 
ments of the operator: if the zinc Htdphate alone is wanti^nl, an 
4>IK*n di«h ia all that is neoey«ary, the action lieing accelerated If 
necessiiry by heat; if hydrogen is requireil, a cloee^l vcjwel and de- 
livery-tube may be used; if a current of electricity i» desired, th«* 
«inc and fiulphnric acid, along with <»thcr material^ are plnce<l in 
g]a«8 or earthenware ccUh, the whole being armriged wii ju* to fonn 
a hatti*r>-. 

Fttrijk'fititm. — Impure %n\c nulphate may l^ purified in the 
same manner aa iinpurt; cbloridt; («<r next vxperimont). 



ZINC. 133 

Zinc sulphate is isomorphous * with magncHium sulphate, and, 
like that salt, loses 6H,() when heaUHi t<) 30(rF. (about 150*'C.). 
An^old name for it is white vitruU. 

Zinc Chloride. 

Szpeiiment 2. — Digest zinc in hydrochloric acid mixed 
with half its bulk of water ; the resulting solution contains 
zinc chloride. Evaporate the liquid until no more steam 
escapes; Zinc Chloride, ZnCl,, in a state of fusion remains, 
and, on cooling, is obtained as an opaque white solid (Zinci 
Cliloridavij U. 8. P.). It is soluble in water and in alcohol. 

Zn -f 2HC1 = ZnCI, -f H, 

Zinc Hydrochloric acid Zinc chloride Hydrogen 

This reaction is analogous to that described in the preceding 
experiment Burnett's deodorizing or disinfecting liquid is a solu- 
tion of zinc chloride. 

Purification of Ttinc Chloride or Sulphate. — Zinc sometimes con- 
tains traces of iron or lead; and these, like zinc, are dissolved by 
most acids, with formation of soluble salts: they may be recognized 
in the solutions by applying the test described on p. 137. Should 
either be present, a little chlorine water is added to the solution 
till the odor of chlorine is permanent, and then the whole is well 
shaken with some zinc hydroxide or the official zinc carbonate. 
In this way the iron is precipitated as ferric hydroxide, and the 
lead as peroxide: — 

2Fea,» -f a = 2FeCl3« 
Ferrous chloride Chlorine Ferric chloride 

2Fi<:n, -f 3Zn(0H), = 2Fe(OH), + 3ZnCl, 

Ferric Zinc Ferric Zinc 

chloride hydroxide hydroxide chloride 

PbOl, -f- CI, -h 2Zn(0H), = PbO, -j 2ZnC], f 2H,0 
fond Chlorine Zinc I>ead Zinc Water 

chloride hydroxide peroxide chloride 

If zinc sulphate is being purified by the above method the 
action of chlorine on any ferrous sulphate present will result in 
the formation of ferric sulphate: — 

6FeS0, -f- 3C1, = 2Fe,(SO,), + 2FeCl3; 

' TnomorpktmM bodies (Ia<K, mo«, equal, and tiofuftt}. morph?. form) arc those 
which are similar in the shape of their crystals. This identity in crys- 
talline form is frequently met with anions substances of analogous 
composition, such as zinc sulphate, ZnSOiJUjO, and nmjrncsium sulphate, 
MKH04,7Ht<). 

' It will be noticed that the atom of iron is represented, in this equa- 
tion, as both bivalent and trivalent; this will be alluded to when iron 
c«»me8 under consideration. 



l:i4 



THE METALLIC RADWALS. 



zint' nxrlinrmU^ will tlicii j^ivt* ziiu- cliloridf tts \\v\\ ilh sulphate?, 
iiml tliii^ tilt' wliok' quiintity of zinc wulphiito will be slightly ron- 
UiininuttHl l»y rlilt,ride. ih% evapomtiii^f auil rryshilH/iii^, limv- 
I'ver, the /inr chloridi' will lie rt^tainid in the iiu>tlier-lii|U<ir» 
Thene i)^!!'*"?*^^ tU [mritiniti^m ii«hiiit uf giiRTiil iipi»lit'utinii. 

In thi^ rhiirmiir(>|Hii:it tlit- piKsHl>U' im^^'iice t»f iuqvuritii;* in the 
zinr is recof^niziil, and ihi- inn* es.^ nf iHirifii'ution just tk-seriiK'd 
i» jnt'orj><irat4^d with tin* i>rtjress iif pn'piniitiun ot Li*pior Zinci 
Chimirfl, U. !S. r., nitrie aeid being u»eil inKtesid tit" ehloriue 
walir to oonviTt rerif^ns wilt intu tt'rrie. 

^/«f Bf'omitU\ 7a\\\t,, find Z^/(f* Imitdr^ Znl.j, art- id^n ntheiuL 

Zinc Carbonate. 



Experiment 3. — To tbt^ stilntiuri of any ^dven f|uaiithy of 
zine ^iilphiite in twire \i» vvd^ht of \vatei% \\Ai\ nhunt no eqniil 
qtmntity i»f sndinni enrlmnnte, iilsi ditv^idved in twiee il^ 
weight <d' water, and boil ; the resnltin^L' white preeipitate la 
Hydrnteil Zinc ('arlninate {Zhiri Ctirhojtai* PruripiatttH^ 
V, 8. F. ). A:^ n bytlroxy-earhonate, it in ai[mlde of Wiw^ 
represented as made n[i of xinc earlmnate, 'AiiVi)^ ami zinc 
hydruxide, ZnfOH),., approximately iij ibe proiK>rtiim of or»e 
nioleoule of the ibrnier aod two of the hitter, tojL^ether with a 
fnolt?ciile of wat^r ( ZNl'O^, 2Zn(()H),,, II^O): thew jimpor- 
linn^, however, vary eonsidrrably. It may he wiL^hed, 
druine<i arnl dried in the tiHiial nntniier. It is ii«ed in the 
arti* uiider tlie name of zii(r-tvhtUj. 



3ZnBO, + 

Zhic sulptiiit« 









=Znn{),,2Zn(<)H),,H,0 
ZliK' liyclnkXycnrboiiAie 



2C0, 

C«rb«»iiW 



+ 






Otfatnitui Pnrp'irftfn in a Nainnth, pale, j(inkyHh-bn>\> n i>owder, 
(dituiued hy enleininff and powdering: native /,ine eiirhonate or rnt^ 
nminr, and freeing the j>rf)dnet from gritty purtiele^ by ehitnatina. 
I*rt*pnrfd nihimine iw cliiefly zine earlwiaate with wnne oxide of 
iron, etc. 

Ehttniithn (Lat. duiritiim, from rhifrh, I decant; rhm. I wnnh 
out). Thi« fraetional o[ieration eonsisti* of deeantin'j r»tl' water or 
other liquid rinitaining lighter and liner partieles in .^nspeasion, 
from heavier and eoarstT partiele?* w*hieh have beeome dep*iHiti:^L 
The dee-anted ilnid yields a >*rdiinent of the tine partielen on 
stancling. By nl lowing varying intiMvals of time U* elapse 
lM«twcH*n tlie slnikiag ami the deeuniaticm, and by asing tlnid.H nf 
diflerent spcciflc gnivities and different degrees of limpidity or 



7JNa 



Kio 



visHMdity, substances of (Sitrereiit spet'ific gnivitie?*, or parti cIch of 
ili Men-fit dt'jfrt'i/j^ (if tiiit^nesw uf any ojh' wubstnuir, amy be ^L^jia* 
ruk'd (r»»j»i each oIIilt. 

Zinc Acetate. 

Experiment 4.- — (\>llet't mi a filter the precipitate olilained 
in the Ijij^t experiment. wvvAx Hith tlistilleil water, ami (lis5«ulve 
II |H*rlion ill eoiK^entrateil iiretie arid; tlu* residtiiij^ Sfiliitioji 
contains zinr uretale, luiii, uu evn[Mjratiii^^ ariil f>i'ttiii^^ a^ide, 
yields Itiniellur i*earlv ervj^tals uf zinc acetate, Zy(Cjli„U^Jj, 
'2H,0 {'Aum AceH^^i:/^, P.). 



Zinc ljydrwxyc4irth>Lia.to Act'iieatid 



Zinc acvUile Water Ciirljirnin 
aiiiiydrtdL* 



Zinc Oxide. 

Experiment 5. — Dry mi a watordmtli tlit; remaiuder of the 
precipitated zinc carlxumte olitaiiicd in ex|>eriinent H, and then 
heat it in a small eracilde nntil a j^anifde taken out of llie 
enicihlediH^s not effervi^'e ontlie aihlitjiai of a dilute acid: the 
priKluct i^ Zinc Oxide (Ziitrl Oxithmu U. R P.)t miit^h n^^ed 
in the form of Ointment (Unffuentum. Zhiei (hndi, U, S. P.). 

^ 8H_0 -f- 



21 uc bydraxycftrboDfitu 21 nc oxide 



8H,0 
Wttlbr 



CO, 

rtiihyilrUie 

AVr. — Zitic oxide i>re|»ared as ahme is yellow while hot, aad 
of » very pule yellow or sli^'ht hutl' tint when cohl, not iictuidly 
white like the oxide prepiircd l»y the mailmsiion i»f zinc in air. 
The preparation of the latter viiriety, which iil«o occars in com- 

<L Fid. 90. 5w 




The l^lowtifpe. 

merce, run only be pructically accomplished oa the lar^e Rcale; 
but the eliief features of the ficiioii riuiy In' nhsierved l>y lieatinitr a 
|iif<co of ziac on chanywii in llie hlowi>ipe-tlame (a, Hg. !iO) till it 





130 



TUfC METALLIC RADICALS. 



biimH; flf^ckn etJcaiH?, flcMt about in the air, and slowly falL Tbc^jse 
were toniiorly onlled Fioreji Zmri^ Lmia Phihmfphicn^ or Kihitun 
Afltum. Zinc oxitk* sbmiy absorbis i-arbuiik- uiihy(lri<if and wiitt^i 
Ironi moiBl air, and lieromes wjfivt^rk'd hiUy hydruxyiarbonate, 

A eleur blow pi po- flame eonsiwts of two ra^ire or bKs tibarply 
drfinefl jK>rtion?i (Z>, Fig. 30), an inner cone, at tlie aj»ex of whirliJ 
there are h*jt hydrocarbon gases ready in combine wth oxygen, 
and an outer cnne, at the apex tif which there is excess of hot 
oxygen. At the latt4?r point oxidiz^hle meLaln, etc., are readily 
oxidized, as in the foregoing exjieriment, and that part of the 
flame is therefore tenacd fht ojxnUdng flmnr ; in the injier flame, 
oxides and other coinponnfls are reduced Ui the metiillie state, 
hence that part Is termed the rtdueinff Jinme (a ^rain of lead 
acetate may he enijdoyed for illnst ration). A blowpipe-flame is* 
much akcDxl in character by flight variatiouf^ in the position of 
the no/?ie of the blowpij>e, by tlie forai of the nozzle, by the 
force with whirh air is expelled fnnii the blow[*ipe, and by the 
chftracter of the jet of g»is. 

Zinc Valerandate* 

EII^e^iInellt 6. — Zinc Valeraudate, or rather, zinc ii?o-va1er' 
andate, Zn(C,II,/>/)^ 2\\Sy{Zim'l Valemmh^, IL 8. 1\ h i» 
preparetl by sjitiiratin^ iiso-valeraiidic acid with zinc carlmn- 
ate or by mixing^ eimeei it rated solutions of mu- sulphate and 
RHliutn ISO- va) era 11 date, cooling, &ej>araling the white pearly 
crystalline prt^ii|*itate, evajwrating the solution at 200*^ F. 
(93,3° C, ), to a mr\ ail v o 1 u nie, cool i n g^ agai n Be para ting the 
lamellar crytals, was»hiii^' the whole priKluet with a small 
cjuantity of ('fjld distilled water, <irainiiig, and drying by ex- 
posure Ui air at ordirmry tem]M'ralure.s, Zinc iso-valerundate 
is mduhle in ether, ak'olad, and but water. Str alsf» valer- 
nndic at^id. 

ZuSO^ + 2NaCyi^0, ^ Na,SO, 4- ZntC;H,0;), 

Zltie sulpho-te Sodium istvviileraaiiiitc Bo^liiiin aiilphatv ZJne lao-vale ran date 
Zivr Sulphide and Zutr JTttdrojritir are mentioned in sub- 
!f«e<|uent imragraphs. The formula of Zinc Sulphite m ZuSO , 

Zinc Phenolsul|>honate, 74n(t\U,0^8\,SU,0(Zinei Phenol- 

mlphonas), and /irie Sbearftte, (Zinei ^Stearas), are included 
in the PbnrmaoojRLda* 

Aunhjliral ReacHtrnfi of Zint SalU. 

L To a solution of a xine salt (sulphate, for example )» in 
a test-tube, add solution of amiiamium hydro^iulpbide^ 




ZiNC. 



i;i7 



NH^SH ; a white pred|>itale of ivm Hiil|ilii«lis ZnS, is pro- 
»Juoeii wbieli is iuHolylile in iie<^*licv Init h<j1uI)Iu iu diiulu 
hy^lroc'hioric or sulphunc ttriil. 

Xi^k\ — Thia 18 the* only wJiite sulphide thitt will bo met with. 
If the asint! salt cont'iins iron or lend jls impurities, tht^ [>reLipitjit>e 
will have a dark appeanince, due t^i rtdiiirxtnre with tlie wnljdHdes 
of the«e racta-l-H, which are black. Alnniiiiiuin hydnixide, which 
ii white and Jiiay also he [irccipi tilled on the atldition of amnirm- 
iuni hydrrjfitilphide, is the <»rdy suhHtance for which zinc 8uli>hide, 
if» likely to be mistiikeri, or which is likely to be mistakeo U\t 
zJDC sulpJiide. As will be tni-n im mediately, there are goiMJ 
of distLnguishiiig the*»e subatances from each other. 

2. Tt> a s<dution of a zinc hjiU add nnimmiia wat^r ; a 
white precl[utate of zinc hydroxide. Zii(OH)^, ie ftirnjed. 
A<ld exceas of the reageut; the precipitate is redii%Hfl>lved. 
This reaetion at oaee distinguishes a ?Jac siilt from an alumi- 
tiium salt, unless the .'Mdution of the hitter is very dilute, 
alurainium hydroxide being almost in».duble in dilute ara- 
tuonia. 

Other Analytical Eeictlons. — PiMa^ssium \yr w>ilinni hy- 
droxide affords a reaciioo similar to that just ujentioned, the 
xiac hydroxide redii*8i*hdog if the alkali d<K'„^ not aontaiu t<JO 
much carbonate. The solution contains pota^iaium or 8<Hjiym 



Zn(On), 


+ 


2K0H . 


= K^ZnO, 


+ 


2H,0 


Zinc 




CaiLstir 


roUaslum 




WiU.r 


hydroxide 




potash 


zfncate 







(Metallic zinc dinscdves m »jlution of ixitassium or sodium 
hydroxide giving hydrogen ami pjta^iuni or sodium zim-alt* : 
— Zti -h 2KOH — KjZnO, -f- H,. ) A minoniuni carbonato y ieldi^ 
lb whit€ precipitate of basi<^ zinc earbnnate, soluble in excess. 
Fota^ium and »cMliuni carbonaU^s gives a similar precipitate, 
which 18 tiot redissolved if the mixed twdution and precijiitatc 
be well boiled to expel carbonic atihydride. Pulassinni 
ft*rro<'yanide produces a white pre<*ipitate of zinc ferrocyanide* 
ZD,Ke(C'n),. 

^r- " -'nrn sulphate, which is itwimorphous with aad indis- 
ti' in appearance from zinc sulphate, does not yield 

■ fi late wlien either potasj^ium ferrocyanide or anHiioiiinnj 

h' irle ih lidded to jU atjueous solution, 

.,,f.,r,c„>.f.— There are no eflicieet chemical means of countvntct- 
lug the [ials(»nous etTei'tnof zinc. Large doses, fortunately, act as 



l;i8 THE METALLIC RADICALS, 

pijwerful e I net it's. If vorjiitiiig: Imn not niTurrcd, ur appiirently tu 
an iTisufficit'iit cxU^iit, s<*lulii*ii uf s<xtiuni carbcmnU' (c^oininnn 
wttsliing iwiila), immt'ciinU'ly follnvvrd l*y \vhitAM>f egg ami iWrnul- 
ceiitfi, amy i>e adiuiiiistered, nud the »ttmiaL'h tben be cleared. 



QUESTIONS AND EXERCISES. 

dive the source's and uses at metjillin zim',— (rive a ftuiKraini rcpru- 
aeutiiiK tliii action nf seine on dilutL+ solphnw liHci. — How nmj^ ^lutioiis 
of Zitie rhioridc or Sulpbatti Iju puriltiefl from iron suite V Givi;<%(uatiuiia 
for tbc? reactioua.— Ciiv*-* tlit^ fi>rinulat of tlio ufficial Zinc iitrboimU% and 
illuHtrHtii by a. diagram the reaction wbich lakeii ji]m;t! in its production. 
— Cfivti an tnination rupresouting thtj pro|Mimtion of Zinc Af-etat*?. — In 
wbHt n^spt'tt dwjj ZiuL' Qjtidc, rejsulting from tbf ignition at the wvrbon- 
at4.% difler from thjit prmlucrcvd diiriug iIhl* cumhui^t ion of the mi^tat ? — 
How is Zinc L'4o-vult>m.ndut« prt.*jiiirt'tl iind what jiro its propurties? — 
Name tbt^ more iiuiHirtJint t-est^ fur if.ine— Itow would you distlnKnisli, 
fbendeiilly, l»clwe4_^n solutiona of Zinc Sulphate and of Aiam?— Give 
reiurtions distiugnishiug Zinc 8ulphat« froiiii >t;t»^nciym Snlpbate. — 
Describe tbc tn^tmcut in casus of pobouing by xinc Haitd. 



MAKGANESE : Mn. Atomic weight, 54.6. 

fibttrrsf.— Manganese \» a constituent of many minerals, and w 
met with in almnfinnfo in the f*niith-west of England, in Al>er- 
det^nrthire, ami in mirst eonntries of Enrojie, as black oxide, MoO,, 
pt/ro/tiA}fc {hma my>, pur^ fir«?, ami ?imr, iusm^ a bxiwing or resolving, 
in allusion to the readine.'^ with whirh it is split up by heat into 
a lower oxide and oxygen). This niinend wears n» a steel-grey 
nia.'^.H of ]jr!t*nMitie erystalj^, ar in black amorphous lumps. 

f/sfj^^ — Metjdlic niangiuiese, wluch may be isolated, among 
other methods, by the action of Bodium on mangan^e fluoride, i« 
oaed in alliiy with imn in the manufacture of some varieties of 
BteeL The black oxide is an important agent in the pnxkution 
of ebloritie, ancl in the preparation of aiiinganateA aod pennangHn* 
ate^, purple ghuw, and bhick glaj^e for earthenware, Mannnni 
Diojidtim Pr^rrlpitafum^ Mnntfani Hiji>oplni}tphl» i\uA Afoni/ani 
SiUphm are include*! in the Pharmacopa*ia, 

EXPERIMENTH HAVING B(*TH SYNTHETICAL AND 

Analytical iNTEHtsT. 

Experiment 1. — Boil sivrae black nmngane^^e oxide wUr 
tHH) cent rut e^l hydrochloric acid in a IcBt-tube or flask, placoii 
til n fiinie-ruphtmrd, until chlorine ii* no Ioniser evolve^!; filter; 
theHltmte is a sidutioii of manga nouacdioridt?, Mni*lj.MnO,-f 
4HCi-Mna,+2H,0+CV 





MANOANESE. 



139 



Tbi8 18 the reaction comiittinly eiiiployed in llie jirepiiratitin nf 
chlorine. It us ailst* n rendy iiiftlinil (jf prejiarini:; ji iimji|jrsini»ut* ^iilt 
fi»r uniiiyticnl exjit^rinienU. C<in[»lrd wilh the ji|*plii'jitJtin of 
reaii^fnt^ tu the (lltrato, the rt'uelion n^ une nf Ihnw Iw whicli a 
black powder or mineral would be recognizeil an hlack niangane?^* 
oxidr. Black uiaiigancj^e oxitie al^o dissolves in tohl coai'eatrnteil 
hydrochhiric acid, foraiirig a dark-hrawn dilution which containn 
a chloride, MtiCl^, ndxeil, |»robably, with (jther uiaiigaiiese ehlo- 

Experimeat 2, — Heat a nuuiganei^e (nmipound with a grain 
or lwt» of potasgiuni h3*drf>xide or carhonatt^ anrl a frai;nieDt of 
jKitiiiiisiuii] nitrate or chh)rate on iilatitium foil in the blowpipc' 
Hame ; a green mass eontaiiiing pofatiMutm jitfutgmtaief K.^Md()^» 
U formed. Boil the foil and the fnged nias^ in water ; the 
inatigaiiate dissolves yic*Iding a greeu solution which *wM>n 
changes to purple owing to tbe ton nation of potapiH^imn ptr- 
jnttnganate^ KMnO^. Carefully j>eriorined, this is a delicate 
tost for manganese. 

Thi« reiiction in tlie one by which pota^^mm pernian^^anate 
{frUanmim rerwamjaua^^V. 8. P.), is i)reparcd. Iv| nations whovv- 
itig the action which occurs in imiking the s^idt have already been 
given in connecti«m with the coiiipfjunds of potassittni (t^et: p. HI), 

In?itead of converting the rnaiiganatc by ehwllition (as deseriltetl 
on p, HI), ajid neutralizing the free alkali by arid, whereby one- 
third of the aianganese is preripitated, chhjrine may be pfLSi^ed 
through the cold solution until the green color is entirely chatjged 
to purple. 2K.,MnO,-f Clj=2KMn(\-f 2KCL 

Sofutifms of poififmum nnd mdinm mnntjanaffn and pcrmnnganaieft 
ufie in CHimmon use as green and purple disinfecting fluids. They 
IfcCt by oxidixing organic anitter, the mnnganie or permanganic 
ntrlic:i1 being reduced and a dark -brown mamjnnitt' formed. For 
thin rea*«on asbe^^to** Hlif>uld h\* usid instead of |>ajier in filUrring 
the w>lutiorii*v 

The changes in color which the green tnanganate undergfK^H 
when clrfippt^l info wartn water ^ave ris*' to the old name minrnd 
ehnmrtrmi, by which the manganate it< still w>metimej« de«erihe<h 

Experiment 3. — Make a borax bead by heating a frngnietil 
of lK>rax on tbe end nf a [ibitiruini wire in tbe blowpipe- 
ftame untH a clear tratLsparent globule is ohtnint^l. Place a 
gnitiUte [>article of a rnaiignnese eonip^nnid, or n droj* of a 
ioliitiou of a manganei*e salt, upon the liead and heat it again 
10 the oxidizing tiame. A head of a pale violet or amethyst 
tint ii« pHMluced. (Tbia ia useful as an analytical reaction, 
and it ill u^r^t rates the use of black manganese oxide in pro- 



1 m 



THE MKTALIJC ILIIUCALS. 



tluring cornnvon |mrple4iiite«l glass). Ex|>os4^ the bead to 
the r*^iuejng part of the Ha me { |». K?H), tlu' color liitiupfieiirs. 
Tlie rhiinge is uwiug lo (he ri'iiuction of the nmii|;anic com- 
jMHiiid to a mangainHis eom|>L>uiid svhich is lu^urly txjlorlt-s:? 
t compare ftTroiis and ferric t'ompoiimK p. 151;, Thh action 
iilso illtistrutes i\w use of lilark inan^fmie.«e oxide io glaii»- 
tuarmfiirture. Glass, wlien first mn(li% is Ui^ually of a green 
tiiU^ owing to the pre^ioiice of sriiuiJ qimiititieH of ferrous ooin- 
poumls; the aiJditioii of tbe mangaiit^i^e oxide to the nmteriuls 
converts the ferrotw into ferrie cornponndH, whi<4i have rom- 
paralively little color, it itself h/nv^ lherel»y redneed to tnungan* 
oitH oxitle which also gives but little color. If excess of the 
manganese oxide ia addeil, u purple tint is pro<juced. 

3[uaganeHe borate ia an iirticle of commerce used for the pre- 
|Miration of drj'ing oil and oil vanushea. When mmst, it actsaA 
§Xk oxidizing agent with great facility, eHpeeially on wfirming. 

Experiment 4,— Through a sokitioii of ii mangauous salt, 
fti.*idulated with hydrochloric acid, pai<s hydrogen sulphide; 
no preci|>itate is proiluced. Add ammonia ; the aniiiu>niuni 
hytlrosuiphitle thus formed prmiuctiS a yello\vish*pink or tlesh- 
tint precipitate of mangatioas sulphide, MuS, 

This reaction is characteristic, nmnganese sulphide being the 
only fleah-C()l<>red nulphido known. The suit used may l»e tlie 
mangiiiioua chhiride prepared in ex^KTiment 1; but such crude 
BolutionB usually give a black precipitiite w ith ainaHinium hy(Jrr»- 
fttllpliide, owing to the jjreiicaee of iron. /Vrr manganoiiA chloride 
may he obtained by b'dling the impure solution with maagamnis 
carliKtnate; the latter decompoaes the ferric chloride, with tlie 
[iroduetion of ferric hydroxide and more manganous chloride^ and 
the evolution of carbonic anhydride. 

To the recently preeipitate<l njanganous sulphide a^id acetic 
iicid; it dissolves. This Rfduhility permits of the &eparation of 
manganese from nickel, colialt and zinc, the i^uVphide^j of which 
nrv in.Holuble in dilute acetic acid. To express* the fact in anuiher 
way, manganese is not precipitated by hydrogen sulphide from a 
solution conUiininif free acetic acid. 

Experiment 5. — To a solution of a manganoiis salt add 
auimonia water ; a white precijiitate of manganous hydroxide, 
MnfOH). is pHKiuced. Add excess of ammonia water ; sim\e 
of the precipitate is dis-solved, and nmy l^e lietef^teil in the 
quickly iiltert?*! stdution by the addition of ammoniuni hydro- 




COBALT, 



Ifl 



bulphide. But bulh precipitate and Bolutioti rapidly ali-t>rh 
oxygen, the luanganese |>aisaing iiita a mure highly oxhlized 

jiiditiuu, hi which it is insoluble iu aiiitiioniu, PotaHtsiyiii 

nd sodium hydn>xides j^ive a siniilar precipitate insolnbk m 
gsceaai The precipitate rapidly ahsorhf^ i^xygen, heconiiriir 
hrown^ and gradually piu^iug into a higher atate of ox i( hi I ion » 
Experiment 6, — To a solutiuu uf a niaugatioiiB ^dt add 
dilute uitric acid^ and eitlier red lead or lead j>eroxide, and then 
boil; a red tint Is ifiipartf<l to the iitpiid, due to the format ion 
of [lermaQgaDtc acid. H chh>ride,s are present, ihe niaugan- 
>fBe, etc., should be separateil by me-jins of sodium hyikoxi^le 
ODlution, the precipitate well washed, disn^lved iu nitric 
at»id, iuyd the oxidu then added. ((Vuni). Or tlie cldorideH 
may i>e got rid of by heating with sulphuric aciil until all 
hy<lnxihloric acid hajs Ik^cij cxjk:»IUh| fAlcock), and then ap- 
plying Crum*8 te«t. An improvement on ( Vunrs teat cjnijii^ts 
in w^arming the Bolntion to l)e te?^tcd, m hicb should be tree 
from chloride, with a small rpiantity of ammonium persub 
phate t*> which a drop of a dilute solution of stK'er nitrate 
has* l>eeu addecL ( H. Marshall ). The pur[de color of the 

jlut ion of permanganic acid in much more easily observed 

rheu this methiMl is employed. 



COBALT : Co. At<jmic Weight, 58.56. 

SftttrrrA, — CVibalt <►<•(• urn .*Nparirii?ly in man re as the arn^enidc, 
LiAny, fin- while cobalt ^ luvl cwraHiomilly as a double :irt*i'riifli' 
ml sulphide, CoA!<8, or cobalt- ijbinc*' (from tjlanz, brightness, in 
JuiHion to it* lui*tre). 
fV«.^It» chief use i» iu the manufacture of him- glann. A 
&hn)l compound ia also the coloring con.stitutcat of mufilt^ (from 
til, u corruption otmtit)^ a variety of blut' >rhis.s ri'ducrtl U\ a 
line powder amJ usccj a« pigmeut by jiapcr-staincrw and othern, 
fiil cuiphm-tj by laundreadea to conceal the yellow tint of iniper- 
rtly washed linen, 

f^f^nit itftlfjf^ which are mostly red^lii^h ami yield pink or red 
NilutifUiK, may he oViCaincHl from tlie oxiiJ**, (%j(); and the oxide 
fffim znffre, a mixture of Hand and roiint^^^d f>re which is chiefly 
rohnit arsenate, Metjdiic cohalt in obtained by reducing cobalt 
oxide (by heating in a current of bydrugen), or by heating cobalt 
oxjdaift in the absence of air 




THK M ETA LUC UADICALS. 

Analtftieal Reactions of Cobalt S(iH^. 

1. Pass hydrtjgen Rulpbide through au afidulat6<l siilution 
of a cikhfllt salt {cc^hnlt elduride, OoCl^^ or tiitrate^ C'o(MO/),,, 
for exaiji|>le); no iirecipitate is j^ro^iuced* Add luuiooniii 
water; thti ariiinoniuin hydrosiilphide tlius fonnetl cnufc^es pre- 
fi]»itatioii of bbu^k cobalt 8idphi<le, Co8* (The moist precipi- 
tate slowly aI>sorhs oxygea froiii the air, yielding some eobak 
&II I [diatc, (.■oS(_>^ ). 

2. Gradually add ammonia water to a solution of a colmlt 
salt; a Idue precipitate of baste salt is produced. Add excess 
of aoimouia; the precipitate \s dLsriidved, yielding a nearly 
(!olorle.ss solution, which is rapidly oxidized l>y the oxygen of 
the air and becomes brown thereby. Potassium and sotlinm 
liydroxitles also produce a precipitate of basic salt inmiuhie 
iu excertB. 

3. Make a Iwrax bead by heating a fragment of borax on 
the end nf a plalinum wire iu the blowpii»edlauie ytitilaelear 
transparent giobide is ubtaitied. Place a minute f article of 
any cobalt compound, or a drop of a Evolution of a cobalt salt, 
y|riu the bead and heat it again; a blue l*ead resultis iu both 
oxidiziog and reducing Haines. This is a delicate teat for 
cobalt 

4. To a solution of a li^dt of cobalt arid ftoluiion of potii^siuni 
cyanide until the precipitate which at first forms has entirely 
rt^iismilved, and further add coiiftiilerableexeej?sof the cyanide. 
Then add solution o{ potassium hydroxiile iu considerable 
quantity and an oxidizing agent &ueh as hrondne water, and 
warm. Potassium eobalticyanide, KjCoC^Kg, informed iu!^)lu- 
tion hut no prcc!|>itate in jjroduced. When a nickel sol nt ion 
is similarly treatc<b the nickel is completely preci[iitated ii8 
black nickel ic hydroxide ; beiu^e this* actiou atfords a means 
of 8ef>aratjng the.^ closely allied metals iiN>m each other. 

5. To a solution of a cobalt salt add excess of a freshly pre* 
jmred solution of pjtaasium nitrite in tlilute acetic acid. The 
cobalt is completely precipitated as yellmv |*otassium cohaltic 
nitrite (Fischer's SjiU), K^Co(NO^\. Nickel aalL«* do not 
give any eorresjxmding reaction. 

Invisible Ink. — Many col)alt comi>ounds cont-aining water 
of crystallization are light red, aufl in the anhydrous state 
are more or less blue. l*rovc tlds by writing some words on 
pn|>er with a solution of cobalt chloride suthcienfly ddnte for 
the charaeters to be invisible when drv : ho hi the sheet In^fore 



I 



I 





NICKEL. 



143 



a fire or m-^r a iiame ; the lettera at once hecome (listiortly 
visible, and of a hlue color. Breathe on the W4>rd8, or set 
ihe slii»et ai^ide for Sijmv time, the ehanieteni^ heeome once 
more iuvij^il>le^ owiojj: to Llic ub^urpliuu of moLsture. Hence 
soUitit»« of robalt diloride form:^ ope of the so-ealled njjmpa- 
the fir. inks. 



NICKEL : Ni. Atomic weight, 58,3. 

Snureei. — ^Theores of nickel and cobalt are commonly a»«ociated 
in nature* Indeed it m from uptUi*^ a nickel arsenio-sulfjiviilc ob- 
tained in the nianti failure of Hinalt, a pigment fjf cohiilt which 
has already been menliuneil, tliiit much of the nickel of efirn- 
tncrce him liilhcrto been olitained. Garnhrife, niagncHiuiu un<l 
nickel silicate, containing no cabalt, m also a valuable source of 
nickeL 

ijitm, — Nickel is ut»ed in the prepariilion of the white alloy 
known aa German or nickel nilver, and h extensively employed 
for plating iren. 

Nit*kd MtiiU^ which are j^nerally p^reen and yield a green «ohi- 
iion^, are chiefly made, directly or indirectly, frotii the metal ItM-lt 
The latter ia obtainefl by reduction of the oxide by Htrongly heating 
it with charcoal. 



Analytieal Rmditm of Nickel Salts, 

1. Paa8 hydrofj^on sulphide throupii an aeiilnhit«*d &<duti**n 
of a nickel salt (nickel chloride, NiCf^, nilrale, Is'iiNO^)^, or 
sulphate Ni80^): no prc<npitak^ is protluecrl Arid amnio- 
uia water; the ammonium hydro^ulpbide thus formed amnes 
precipitation of black nickel sulphide, NiS. 

JVblf. — ^When nickel sulphide is precipitated by the addition nf 
ordinury ammimium hydro«ulphide, which contains fn>e* sulphnr, 
dtlfic:ulty IS cxpc»rienced in ohtainirig a rJeiir liquid on filtt^ring 
the mixture, owing to the fact thtit nickel sulphidi' disf^olves to 
iome extent in excei<» of yellow ammonium bydrosulpbidt*, form- 
ing a dark-coll irrHl |iqni<l from which nickel .^nlphide Hcparates 
slowly on exposure to tilt* air. Frron this filtrate, tlie whole of 
the nickel can l>e separated in the form of sulphide hy adding 
exccM of acetic »cid (which decomposes the yellow ammonium 

drowulphide — the 8«olvi*nt of the nirkel sul(>hid(») and filtering 
_Bin. It cjm als(i he scparatetl by driving iiway the amuioriium 
hydniHulphide by evfqMirution, Jind n/fdtenng. In the tatter 
nit'thtHl, rwnneof the nickel sulphide usually undergoes oxidation 
into nickel ffulphat(\ NiHO^, which pas^:;; into s<^}Intion and must 




144 




THE METALIJC nADIVALS. 



he removed by repretn|iJt4itiuH ijw »uljilii(ie (Ity adtliiig a fow drops 
id' HoIutioiL 111* atiniiiPTiiiiiii liydniriulphide and thi^n aetdulatiiig 
witJi acetic arid), and rdtniticm. It is «xTasJMii;illy jinirtiialde 
t) nvitki the diHiuidty liy jiretipitiiting iUv idrkt'I swiphidt* from 
an animniiiai jil solution by int"iiNH of hydro^^i'ii tiuljdddi.% or by 
using iVesldy-auab' mnnioniiiai byilrosuIj>hidu in uliirli nicktd 
«ul|dddi' is inj^ohiblt'. 

2. Add ammonia water flmp by drop to a HohitbiiJ of a 
int'k*d mil ; a paUvirrtn^ri jirt'njiitato uf ha.sit* .silt is pnidiHxni, 
es|vec'ially on lioiliii^^ tlie mixture. Add excess! of nnnoonbi; 
ibf preripitate ibssolvct', yieldijiLT a blue nidutii^h. PotaKsium 
and fM>dium liydroxides produce a pale-grtn*n jtrecipiuitc of 
of nickel hydroxide, Ni(Ofl),^, injioitt Me in exeesF. 

♦3. ^'it'kel .sjilts eobjr a lM>rflx bead reddisb-yellow when 
beiite^i in the oxiiliziug tlame ; on beating in I he reducing 
flame, the lunid lieeoiiie?^ gray and tipa<pie, 

4. To a solution i>fa idekei 8aU add solution of jiotJiSHium 
cyanide; niekel ryanide, Ni(<'N )., is|ireei(>itated. Add excess 
of sidution «d' pitussiuni (yai^ide ; the preri|iiti\le is dissolved 
with iormalion of potasi^iinii niekoi cyunidc, K.NifCN )^. Then 
aibl isoliition of j>otii?wium hydroxide in rotisideralde i|tiantity 
and brnniine water* aod wurnu The nickel in eoiupleteJy pre- 
cipitated as Idaek nickelie liydroxide, NifdHj^. 



QUE8TI0N8 AND EXERCIHE8. 

Name the romrnonrst ort^ of mtinfTiineso ; und uive ai» efprntion des*'rip- 
liv«» of it» rmctifm with bydnndilciric nc-id.— Expluiii th*- formation of 
|H}t)kS!%iuu} jH rm Jill ^3* Jill tt\ sivinp t-ijiifttion?*,— Itnw do iM>iji,'«iinu nu»n- 
jpitiate ntn] perinun^ri;itx* jK.t iw disiuri't-taTiLs ?— WJint uro tin* cliier testa 
fi»r nmnRjOH'sc? — \Vh:it aro the rliicf iis*s c»f the romfxtuiidK of cwbnlt? — 
How in cijthalt analvtloiiny dintiriiJ^iiLHhod from nk-kel? — Mention Hppli- 
rjfctioDB of nickc^l in the art«.— Wliat is tho usual color of utckel silts? 



DIRECTIONS POtt APPLYING THE AKALVTICAL RKACTfONB Bfi- 

8CRIBED IXTirE rORi:noiN« J*AllAr.Il\|*H.STo THE ANALYSIS 
OP A N Ag IT KOIT8 Kl ILUTION O P «A l,T« t^ONTA i N I Xt J ONE OF THE 
METAIA S5INC, MA.VaAKEHK, COBALT, KICKJSL. 

First i»oU' the c<dor of the Koluliou :— 

Si»h}linim of /inc H.-dt-^ i«ff r'<i|urle86. 



SIVKKL. 



145 



8*»luti<ins of iimnj^iinuus ^iilus art* cnlorleHii ur very ^mk' piuk. 

S»UitioriH uft'tilmll >*iiltH are nir^e reil. 

Sdluliiifis* oriut'k(/l salii^ are grft^ii. 

Add iirDinnnium ihloride, ammonia wak^r until the Hqiiifl, after 
shaking, suielk uf tiik reagent, and then aiumouium hjdrosiil- 
piiide : — * 

A white precipitate iridieates zine. 

A butfprwijdtate indirati^s manganous salt. 

A bhiek preeipitate indieate?^ a eobalttms or a niekel wilt. To 
diatirigui.sh between rnlialt and niekel, add ammonia water 
gnidually to a portion of the original Kolntion, without previous^ly 
ariding ammonium ehloride, Ctibalt gives a blue preeipitnte^ 
wjliibje in excess jind yielding a brownish stdut ion wbieli gradually 
cbirkenH. Nickel gives a green precipiUito wbicL disBolves in 
cxeeiW yielding a blue nrdution. 

TABM*: OF SHOitT I>lKECTrONH FC1K APFLYINO THE ANALYTICAL 

nKArnoN.s dehc:!ribei» in thk forpxjoino FAiiAcniAPHs to 

THE AKALYSIS OF AN AQUEOUH SOLUTION OF SALTH t>F TW<'Qlt 
MORE OF THE METALH, ZINC, MANOANEBF^ ftJBALT, NICKEL. 



If the dilution is neutral^ acidulates it with acetir acid ; if it 
is iirid, fuld iinunoriia whaler until alkaline and then aeidulate 
with at etic aeid. Thrciugh the acetic acid *wdutioii pa^H hydrogen 
t^ulpbide until tlie liquid, after shaking, huicIIh of this gaa j 
6Uer. 



t 



Prw-ipifdUe, 
Zn, Co, Nl 



Hiiil with rif l and a little IINf3j,add KOH in ex- 
liker. 



Pren'piMr. 
Co, Ni, 

ni>w»|vf* in Iiri ; test for Xiih dcseril**! 
in ]{eiiriion I I p, 1 U), If Ni nliwenlj test 
mluii(»n fitr Co hy liurix l>»iid fp, 142> ; if 
Ni prei*ifiit« HltL^r olT nickclie liyilroxide, 
tnd icffl fiUmtct fi>r Vo hv UmiiE'lieaiL 



FikraU. 

Add 
wlnle ppL 



Mn. 

Add NIT/>H 

in excess. 
Buftppt 



1 A mm on i urn liydrtMiilphiile iirlib'd to aii iinitauaiiM^iit sultituHi vmt* 
lilfiltti; uttimoniam I'liloricks is the group rr'jiKt*iii fnr ziac, luanganonii, 
ot^tMiltouii, au<l ijjekel tmltM. 




146 



THE METALLIC UADWALS. 



ALUMINItJM: Al. Atomic wci^'ht, 26.9. 

Ornirremr.^^ Almmnium in almiKlant in iiiitiire, (iceurring 
rlik'fly lis silicate, in rlays^ Hljite, marl, bjisnlt, iimi many other 
tiiint'ral^. Mica or itimimtfeti taie euiiHist* t-'lii^eHy of aluiniiiiuni, 
in^Hj iiiajrjjemum, and |i(>tiiK^iuni silicaU***. iSfntielfe in mag* 
nisiiun aluniiMite, Vm^umiuin^ sapphire^ ntbi/, ami amdhji^t are 
almost jture aluminium oxide. Emery is an inipure aluminium 
oxide. RoHen Mtme i^ a iwift, friabli»ahimiiniim ssilii-ate containing 
a little organic matter. (^t^oHte w> a double aodium and alumi- 
nium fluoride. 

The metal aluminium i» obtained fmm the double aodium aod 
aluminium chloride by the action of metallie srHliurn (the soua-e 
of the ehloride l>eing tlie iniiieral 6(tujift\ a more or Icrh ferru- 
giiinuH aluminium hydroxide j; al** by the eleelroiy*^is of erjolite. 
It is readily atUickcd by various acidi*, but dilute sulphurie acid 
only art,s upon it slowly. 

Aluminium is a remarkably light metal, ami in ennaequence of 
thit* property and of the fact that it is [>ractically unchan^^ed by 
expomire to the air, it iw now largely employed for the mountings 
for ojiera glas.'^eH, etc., and in making cooking utenmln for the U(»e 
of travellers. It readily fi>rmH alloys^ (Mf p. 20it) with other mc- 
UkU. One part of ahimininm fnwd with nine of eoinier gi vesi alumi' 
til urn hnmzr, A/nmhiium dve/ is a hard and tenacious alloy of 
iron with n little aluminium- 
Alum {AhtMf'n, (7. iS, P.), aluminium and j>otat«wium sulphate, 
AIK(S(\),, 1211,0, may be obtained from alum whale, an alnmi- 
ti(iu?< ftehist (frrmi mutiT^i;, Hchistm^ divifh»(l) containing iron pyrites 
nod ftoim IvituminouH matter, by expo«iure to air; oxidation in 
presence of moisture gives rl-^e to the f(»rimition of aluminium sul- 
[duUe, ferroui^ sulphate, and nilica, frrun the nluuiininm silicate 
and iftjn bisulphide, FeS„ (iron pyrites) originally pre^^ent in the 
■ihale. The aluminium sulphate and ferrous sulphate are diemilve^l 
<mt of the ma-sfi by water, and potaseium sulphate or chloride is 
added; on concentrating the liquid, alum erysl3dli?>es out, while 
the more miluble ferrcju« sul[drate remains in the mrither-liquor. 
Alum is more trnjuently |>repared In' ili recti y flecomjxi^^ing the 
aluminium silicate in the calcined shale of the eoal measurw by 
mt^ans of hot sulphuric acid, potassium salts Iwdng ad«led front 
time U} time, until a solution is oblaineil which is sufl^iciently con- 
centrated to crystttllixe. The liquid, well agitated during cmiUng, 
depfwfita alum in minute crystals tenned tilum-fionr, which is after- 
ward recrystalliwHi. 

Alum*, — A series of double sulphat4^ analogoun in composition 
to the alum just mentioned, have been prepared in which sodium 
or ammrHiium nniy take tlie place of potjissium, and iron or 
chromium may take the place of aluminium. These salts are also 



ALUMISIVM. 



147 



I 
I 



I 



CJillefl Rjumj^; their genenil funuulu is jr'^>f'{SO^).^, 1211^0; jiiid 
thi-y ull cry still lize in octabi.Mlrii, The i^ludeut wlniiild mAe^ thiit 
in>n aium (beh>w) and I'ln'omt* alum (|i. 1*>8) do not contain 
jilnniiniuin. Fern tt Amimmii Sulphftn, U. 8. P., m iron alnm, 
FeNH,(HU.)„I2H,n, 

Ordinary alum coniumnly occurs in colorles^^ traniiparent, otta- 
liedr^l cr)Ht4dH, nitussed m \\i\i\\%^^ vvhii-h stre roughly broken tip 
for trade (*nr|KjiieH, but wliich Hlill exhibit the faces* of en tahrdni. 
The fomniert'ial article i>?onietinie.s euntninf* piita-^siuni suljduite 
(jHitaKh ahirn), wjnielijne« aiunioniuni sulphate (ainaiunia ahun), 

N(ifi\ — The aluminiiiiii idom is trivulent, antl the formula for 
aluuiinium chloride is AH'i.,. The erjmp<witii»n id' aluniininni 
sulj-diiite i^ never represented by means id" a forniuhi with a single 
atom of aluminium, since this would involve writing Al(St),)t^j. 
In urd^r U) avoid writing a fraction, the whole furrnula is doubled, 
when we get AljiHOJj. 

Ej-penment, — Prepare aluui by heating a ><mal] (juantity of 
jMjwdered pipeclay (fdunn'iiiuni silicate) witb alK»nt twice its weight 
of Kidphurie acid for mm\t tiaie, disstdvijig the resulting alumi- 
nium suljihate anrl excess i>t sulpburic arid in water, and add- 
ing |>otass?iinm carbonate to the clear filtered solution until, after 
well stirring, the exeess of acid is neutral i/cd. (It too much car* 
bonate be added, the fihtminiuin hydroxide whieli is firecipitatcd 
when the carbonate is first ]ioured in will not be redissulvcd even 
on thorough ndxintg. Perhaps the readiest indiration cd' neu- 
tnility in this and sinnlar can^ is tlo' prcscui-c (»f tt s^mts^f ffUffntidj 
of precipitate at't4*r stirring sind wanning the ndxlnre,) On 
evaporating the eh^ar solution, m'stiiis r»f alum are obtaineiL 

Afuminium Srtfphftff ut ^*Ainttt-rakf\'^ AU(Sr>j)t, l*>lI^O, pre- 
piired frnni natural silicutos in the jrmnner just dcHcribed, im a 
eon)inon article of triule, serving (oii^t of the unuuifuctnring jinr- 
|Mjw*« for which alum was f<>rmerlv emploved. (Ahtmhil tSufjthoH^ 
U.8.P.). 

Ihitfl Alum {AluTtten Ejr»iretttum^ U* S. P.), is potamnm alum 
fn*m which the water of cry stall i/jdion has been expelled by heat. 
Hy rnb'ulation from the formula, it will be found that alum eon* 
taiinn hi'tween 4o and 4tt [lercent. ^it water. I>ried alum ra]»idly 
n*ab(icirb& water fmm tbe air, and is 4owly but romjdetely soluble 
in wat**f. At temperatures above 400*' 1\(204.4'' i'.), ammonium 
alum if* deconi[M>?4fd, water, ammonia, and suljduiric anhvdrido 
esctitping, and pure aluminiuui oxide, A I/*.,, remaining. 

Rarhf ahtm, or AV^jt nhini (Fr, /vir/o% rock), is the mime (>( sin 
impun? native variety of alum eontaining iron. The article snld 
under thiH name is generally an artihcud mixture of conuuon aluni 
witli ferric oxide. 




148 



TUE METMJJV RADICALS. 



Anaf^timl Readimis of Aluminium Salta. 

1. TiJ a Btilution of an aluniiiiiuiii mh (aluov, for example, 
wliH*h coiitiiiiis alomitiiitm sulphate) ad<i ttmmonium hydro- 
siilpliide; n wliite gelalmi>ud prei'ipituteof alumimiim hydrox- 
ide is produced:— 

Alj(SO^), 4 GNH^SH -f 6H,0 - 2A1(0H), -r 3(NH^);S41^ r BII^ 

2. To a solution of alum udtl amniouia water ; aluminium 
hydroxide is precipitated: add excess of ammonia water* the 
]>redpitate is |>ractically iusoluhe, 

Principie of Ihjeinfj % hfjlp of MonianU. — ^Precipitate<l 
aluminiym hydroxide has i^reat athnity for vegetable eolor- 
iug-rnalters, and also for the fibre of cloth. Rejjeat exjieri- 
nient 2, but before addir»g the ammonia water, introduce into 
the test-lul>e i*ome deeoction of lotfwtxMJ, solution of ctx^hineal, 
or otiicr solution of an animal or vegetable coloring-niatter. 
Kow add the reagent and Bet the tube a^ide for the precipitate 
to settle; the hotter takeiJ do\en with it all the coloring-raatter. 
In dye worksj, the undyed fabrics are treated with solutions of 
altindnium acetate iu such a n^anner as to deposit aluminium 
bydroxide within their iihres, and are then pa}^*sed through 
the coloring S4)lntious, from which the hytlnixide almtra^tB 
coloring-njatter. 8ome othtT metallic hydroxidei?, notably 
those of tin an4l iron, rei«eml>le aluminiutn hydroxide in this 
res|)eet ; they are (ermefl wortlantii (ihnn mordeuti biting); 
tije substances they f4irm with coloring- in alters are called 
luken, 

3. To a solutiou of alum add solulhm of |M>ta^iym hydn>x- 
ide; aluminium hydroxide is prwipitated. Atld execHs of the 
reagent, and agitate; the precipitate diyscdves. 

Aluminium hydroxide may be jirecipitated from this sidu- 
tiou by neutral i zing the jiotas^^ium hydnixide with hydnn 
chloric acid, and adding amnHuiia water until, after shaking, 
the mixture smells of anunorda; or by adding a nufficieiit 
ifuantity of s<dution of amnionium chloride to the alkaline 
liquid, and lM>ilit»g until ammonia is no longer evolved, 

4. To a wdnlion of alum add s^dntion of pota^ium or 
8o<lium carbonate. A precipitate of aluminium hydrt>xide 
{Alumini Hydroridum^ L\ S» P,) is produced, and carl>onic^ 
anhydride eecajiea: — 



I 



AI,(80.),4 3K,CX\-f;SH,U -2AUOn),-f3K,8t). + 300, 




QUESTIONH AND EXERCISES. 

EriattK^r»t« tlip chief iiatimil ri*m|»tiinnl:i(M" ulimtiniiint?— WriUMiuwn a 
foniitibfc wbiiili win rrjtri'wnt eitlii-r of tliivalumH.— Wliiili alum is (jllicial, 
and « omrnonly t'»iJi>lKVi'iJ in the arts"/ — 8 late the sourci? jiiid i^x]ihtiti the 
rumiittion of aliiiu. — Wh»t is the crystal lint" funn *»fiilyiii ?—Caku lute 
how niueh dried alum is Lheort4i<''ttlly prtMlufihlin rrniii llK> poiiiitls of 
l>otii!a!iium alum. A »«,, 51 lb. 7 oz. — Shtiw that ordinary amnitmium ulura 
it! lapjihk* i>f yiddinjj ll/jHft jwreeiit. of aliiniiniuni oxidt.^— Why nre 
jiliimiiituui rom pounds list' <t in dyfiriK? — How are aluuiiniiitu siilLs aria- 
lytically dLitinguished from ziue salts? 



^^^^^^Qdwmil— 



IRON : Fe. Atomic weight, 55.5. 



I 



^JrmiiMHin*!!* «»f imn aro nbuniLuit in ruitun*. J/rrr^- 
rw/ir Iron 0/r, r»r LotutMonr { LoflrAftmt' fir I^<niiifom\ from the 
Saxoii ftrtlan^ to leiid^ in iillusi^m tn its, or mtliLT, to i\w us^i* of 
magnots in:uJe from it, in mivigatinn), Fi'^O^, is the chirf oro from 
whirh Swedish imn in nmdci. Much <»f iht' RnsHian iron h made 
from Spenuiar Iron (he (from ttptTttfum^ a mirror, in allusion in 
U> the lustroUM ruiture of the iTVstals of this mineral); thin ami 
Red /frmniUe (frtmi alfia, hahna^ blond, su named frnm tiie color 
of ite «treak), an ore raiH<>d in L!ineaf<Iiire, nrv eompo.'4t*d of ferric 
oxide, Fe,Oj. Brown Ifirmnfife, nn oxyhydroxidi% Fe^<.>{nll)^, 
b the wjurce of nuieh of the French iron. NerHle iron orr, or 
g^thifr, JH also an tixyliydn*xide, FH >(OH). Spfifhic Iron f)rr {from 
tpalfM, a niic<*, ttllnnion to the laiiiellar strniture of the ore) in 
ferroiisi e^irhonate, FeCU),. An impure ferrous earhonutci foniw 
the Chfj IrfiHittfmr^ whence most of the Kn^liHli iron iw derived. 
The chief 8ef>tch ore in idm) an iTiijiiire carlwjfiate, containinj:^ much 
hituriijnau$( raaltor: it u known a.s Hhrk Bnnd. Iron Pr/nhM 
(from rri'Pf pnr^ fire, in allusion to the jiniducticm of s]iarks when 
8har|>Iy struck, I FeSj, is a yellow, lustrous mineral, now la rarely 
Cfniploycfi &s a Mource of f*tilphur. Ah met with in coal, it m 
comtiionly t(»rmcNl coal bra»t*eA. Ferrous hicarlmnate, ehlorifle and 
sulphate^ aometiincs occur in sprint^s, the waters of whi<*li are 
hence U?nned chnltjbfafe {rhabjb^, steel). 

Manufneturr of Iron. — The manufacture of iron from its ores is 
carried on an a continuou*^ procenw hy nveani? of the bfrn^f-ffirnnrr^ a 
high utructu re built with fire-bricks, Most manufacturers employ 
a iniifturo of ores — the oxide ore« simply in the cfindition in 
which they are mined, and some other orej^ aft^^r the preliminary 
operation fif rt}f tJ*f in f/, or stronjjiy hejitin^ in air, to convert ihern 
into ojtidc. The mixed orc*s. along with coal and liniestone, are 
fed into the t<>p of the blast-furnace, ivhile a current of heated air, 
fbrr^ in at the bottom onder eonsiderahle i»rt^s«ure, caust^ the 
cmal to hum rapidly, and thiTeby nmintains a very hi^h temiKTU- 
tm« Inside the furnace. In the coiir»e of tlieir passa^ down from 




IfjO 



THK METALLIC RADiCALS. 



the top, the iron oxides give up their oxyf^en to fonn cnrbc*inc 
itnhytirifle, :»ii(l the redueiMl jnm liiekle?^ duwii iind ecdh-et^ at the 
bottom of the fiiriifii^\ On its vv:iy dimn, the iiitdted oirtid is 
prf>leited from the nxidizioj:' lution uf the h<"t-tdr hhist hy the 
sfuij^ u t'lisible irliissy suhjstiiuee whieh is produced liy the iiilerae- 
tioo of the liniestooe with the siiiid and elny i^re^'Jit ass iuij>uritit^ 
in tlio ore^. The fusLMl slag c^jlh^et^ in a l:iyer whirli lies oij the 
top of the luel ted iron und it* oeejt4oaally iliawu ofl'. The irtiii 
h tilno dniwn tiM' froai time to time, aJid ii^ allowt-d tii tSow into 
narrtnv l>raiahed ^ittersi moulded in siiud, where it eooln aod 
wolidifies, and m aiterward broken up into fraji:nients whieli eon- 
»i'\iuU* jth^-ii'oti — the form in whieli tyitif-hon is nu-t with iii eoru- 
aiertv. 

The (*iu4-iroii thus j»rodured may be t-on verted into wmwi/A/- 
iron hy buruinj^ otit tlir 4 or Ti jiureent, of earUm^ silicon* ami 
othtvr im(Hjntie?* jrreHeiit, l>y oxidation in n furnaee — an operati<»n 
ttTiiu'd pudtUhiif, Stiri y iron eoirtsdnin^ from 1 to 2 j>ereent. of 
carlton. It in now made by thi- Lk^ssH-uKT i>roL'es8, wliieh roiiHiHtB 
ill Imruin^ out from ejmt-iron the variable jiniount of earbon it 
eontidiiK, aJid then addinj; melted iron eonUtining a knowji pro* 
portion of earhon. The ofhrial iron {Ftrrum, U. S, P.), ia 
^'ao-tallie ir<>n, in the form of fim% bright and iK»n-ela.stie wire/* 
a fonn in whieh inm is eonveiiiently i*mph>yerj for eonven^ion into 
its eoni pounds. In the form of a line powder, metiillie iron is 
emtdoy<"d an u medicine (m^t p, HI 2). 

I^ftperfirM, — The npeeitie gravity at iri.5 C, of pure ir»>n i» 
7.H44 ; of the bent bar, or vvrou^dit iron 7.7. ItJ* color is bbiisli 
w^hite or gray. Bar iron retjuirefl the hi^^hest heat of a wind-fur- 
nace for fusiori, but below that tempeniturt' it aj^snmeH a pawty 
couHistenee, and in that «tHte two jiieeeis nuiy be joined or trrhini 
(flernu wf/frft, to join) by the |»reK*<nre of blows from a hammer. 
A little Kjind thr<rtwn up*»n the hot inrtal ^iu■ilitate^ thin operatkin 
by forndT)); with the .HU|>eriiciid coating of oxide of iron a fuj^ible 
f*hi^, whit'h is di;<pi'rwMl by the blows: the purely metallic wtirfaeea 
are tlius better enabled Ui come into thortui^b contact and enter 
into perlV-et union. Iron is iviifldy ductile, and of all ctmimon 
metals |»oHsi'Sfie.H the ^i^rratcHt anmunt r»f tenacity* At a hi^b tem- 
perature it bums in the air, forming black nnipnetie oxide. 
Onlinarj^ inm rujtf in eldefly brown terric hydrnxidi- or ox hydrox- 
ide, with II little fernms oxide and carbouute; it in prodncc^l by 
artion of the aniislure and carbonic jinbydride of the air and suh- 
stH|Ucnt oxidation. Steam ]taj*sed over iron heated to redneaa 
yields hydrogen and magnetic oxide of inm. 

Qtmntirnfrrtre of Intu, FiTtfiu^ and Frrrir Snff^. — In it*i union 
with other element*^ and with radiealu, to fiorm sidt,^ iron exhiintit 
the |>roperty of eondiining witli the«*> in two projiortiiiris w> tm to 
give rii!*e to two distinct srts of salts. In one of the>H* sc^ts^ iron 
nppcars an a liivalent metal, the fornuda of the cldr»rifle being 



I 

■ 
I 
I 

I 
I 



eing H 




FERROUS SALTS. 



151 



I 



Fcri,, Uint <^*f tlie f*ul]ihiik', I'VSi)^, itr. Ill thr *»tlHT wt, in»ii is 
trivalt*nl, the ruruiulie mI" thr c Irlnriik* and siilplmtc beiii^ I'VClj 
aiifJ Fe.^(80Jj re.M|MH'tivi'ly* Thiw tntj i^'la of ssilLs nrt re^nnlvd 
an ri'lah'd U* llu' lw<i liiisir (ixitlcs *»f iron, FiO aii<l FrJ^g (the 
phu'L* of the <ixy|:^fn i^l' tJu* Imsit* oxides l>drig tuken hy aiid 
rallied), JiJid tfiey are kn<»\vii sis frrronA siiid ferric salts tl^'^jilh!- 
tively. Tints tlie **liivvrr'^ chloride, FeCl^ (or rhlnride rontaiei- 
irjg the srnalhT jinipiirtioM of ehloriiie) im h.^rrou.'^ ehluride, whik' 
tht* " higher '^ ehloride, FeCl^ (i^rehhirhh* eontaiiiinj< the hir^er 
{iru|M)rli<»ii of clilttriiie), is ferrie ehh»ride. When the aJjidytieal 
feaetioiif* of iron t^ilts i-fuiie to be Hludied, it will 1h* found that 
thow* of tlie ferroUH and ferric wdtK are (jiiite ditlereiit frojii each 
other and enable the Ktudeiit to awertain in which of the two 
foniis rif londdriittton the iron ij! prest^ut. This fmiture of fortnlnj? 
two Hejwirate nets of mltrt iw not pecnliar to iron, hut is met with 
in the ciim?** of cojiper, mercnr>', and varii>ur< other metals. The 
t^ninnationj* orM and ir are eiii|doye<l in these eases in a eoiisintent 
nmnner, the f<frnier always denoting the eomjionnd contjiininif the 
siiiiitler, ajid tlie hitler that contidiiin^ the hir^er (iroportion of 
oxyiren (in the eant^ of the Imihic oxidt^) and of acid radical (in 
tilt* ea^ of the aalt^). 



FERROUS SALTS. 

Ferrous Sulphate. Iron Protosulphate. 

Experiment 1, — I'laee iron (sniidl tJicks) in dilute sulphuric 
acid, aceel era ting the action hy heat until etferveseenee ceases. 

Fe + H,80, -- Feb^O, + \\, 

Iron Snlphurk' ftcld Ferrous siilphulc HydrciKon 

The wlution Cfmtain» ferrous suljvhnte, anrl will yiehl m-8- 
tab of that Hyl*s*tnnce, FeSO,, 7H..O, ( Fen-i Sufjtli^jH, U, 8, P,)* 
on eiK>linj,^ or on further evajHiration : or if the hot tMii- 
c^-ntrateii wdiition W ]M)ured into aleidnd, the urixture Ihein^ 
well-*«tirr(Hl, the Hutjdiale it^ at once thrown down in minute 
er}\stab ( Frrr't SttiphtrM (fraftithttttK l\ S. P.)* At a tem- 
perature of 212"^ F. (KHrC. ), terrous siilfdiate lone^ six- 
acventha (jf Its water, and iK^comus Frri iSttipIniH ETsicvattin, 
V. K P. 

iOfhrr Sfjurrrn of f'Wtm^ Sulphite.— \n the lal>orlaor>^ ferrovij* 

llfiluitr ii« ciftt'n ohtaineil as a hy-|>rodurt in making hydro^'cri 

mtlphide (p, 100). In the niarmfactnre of ainnt it iH-cum ns a hy- 
pruduet in tho ileeoinpoKitioii of the alaniinoUB shale, as already 
ntitiit^l (p« ]4G)< 



152 



THE METALLIC RADICALS, 



A ten |»t^rcent. solution of ferrous sulphate iti iliKtillt*cl water 
wliitli h ts l>wTi prfviiHiisly htiilnl, L<*ristituti^ *^ Fern*tis Siilphute 
TcHt !S*iliiti(m/' U.S. V. *' Tills sohit inn shituM Ix- fre.^hly iire- 
jmreiJ imineiiiiitely before use, ' ■ UeciuiHe of iin linbility to ubsorb 
oxy^a^u with fimnatiou af ferrii- oxyKulphnte (»ee below)* 

^\o//-v«.— FrrrouH sulphate wuk fonrierly terimnl (frvf^rt rlfrlol. 
Vitriol (triHO vilnim, gbi>»M) wilh originally the uiiiiie <if iiny tnms- 
jiareut crystal line aubstiUice: it wtiM afterward rest rir ted to the 
i^ulji hates of ziat% iron and copfjer, which were, ami Btill are oeca- 
»ronalK% known itn white, green and blue vitriol re,sjM:'t'tjvely. 
Coppenm (prohahiy originiilly (hppfr-tKHt^ a l^-rni ii[Jttlii'd U» ver- 
dig:riH and other green intTUstulions of copper) in another jninie 
for this* iroji rtulpliate, sonietinie.s distingui^<hed as qnun coppnuu^ 
eopijcr Hulphate heing bhie copperaH. Kxsircated lerroUH sulpli.itc 
\s a eon?4tituent of Pi i a hi Afot-a d Ft'fri, V. >>. P. Ferrouj* ful- 
j»hjite forms n light green double nuilt with anunoniura suljdiate 
(iunnioniunj ferrous sulphate, (X1I^)3,S()^, FeSi*^, t>H/))» 

perrons sulphate, when exposed to the air, gradually beeonies 
hrowii through whsorptioti of oxygen, ferrie oxysnlplnite, 
FeJ>(8(_)Jj, tieing fonued. The httti/r is not C(»uiplettdy din- 
solved hut is deeoinposed by water, witii the forjnation ot n still 
lower insiduhle oxYsalt (FciO^SOJ, and s<iluble fi?rne sulphate: 
r»FeJ>(S();),- Fe/),S<>, 4 aFe,(SO,),. 

Iron heated with un<lHnted sulphuric acid yields sulfduiroua 
anhytlricie and ferrous sulphate: 

Fe f 2H,80, ^ FeSO^ + SO, + 211^ 

Petrous Carbonate. Iron Carbonate. 

Bxperiment 2. — To a hot solytion of ferrous sulphate, in a 
te^t-lui>t\ adil a s(»iutiou of .smJiuui bicarhumte, whidi has 
been prejwirni with water at a tera|}erature not exceeding: 
r>0**t^; a white |>reeipitate of ferrou.s earlionate, FeCOj,, is 
]>rfHlueed whieh ra[»idly beeoiuei* lip: ht -green, bluish green, ami 
im standing for s<Jn)e time, reddif^h-browu, owing to ak'^orptimi 
of oxygen; oarbonie anhydride is evolved, and ferric oxyhy- 
droxide i» formed. 

FtvSO, 4- 2N\HC0, = FeCO, 4 Na,S(), V H,0 + CO, 
Ftirroui Hrtdiuiu FerfiMis SfMfium WiiUsr C«ir1*on1p 

Ku1t>h«ie bIcarbQfi&ie curbonniG Hulphutc mu1iydrii1i> 

Saeeharaied Ferroun OirAorui/A — The above preiipitiite of fer- 
rous cjirbnnate, rapidly washed with iMiiling distilled wat^r, and 
then riitxed witli sU'/ar anil ijuiekly dried — all possible pret^uutioUA 
being taken toavfdtl prob»nged exposure to air — -fornis ^aecharatefl 
ferrous carbonate (Fern Vttrbonax Survhamtm, U, 8. P.), Thi« i« 
probably u mixture Kit ferrous ciirbanntc^ cte,^ with Bii^r; a 





FERROUS SALTS. 



im 



I 



/H)f/nf/ kiiovs'n jiH iron >tmf'ftft\ ripntuinJMjL'^ nlHtut 4^.5 jicm'Ht* uf 
ifiin, 18 iiUuiineil l»y inmring a s<>JulHiri nf rnne-siipir ami li^rric 
liiltinile int^i a .slight cxcvhs <if wkHuhi hydroxiiiL*; a n^iltlisii-bn»\vn 
crviiUiIUnr precipitate^ is pnnlufiMl. Irtm maUmate is an analogous 
uoin[>()niid, 

Sotrjt. —The red pt*W(i€*r tiirniL^rly termed (.'iirlifnuite ur ISiilK'ar- 
Ixmate of Inm {Ferri (**trhofifiJf or Pmi Sabrnri/atuiJi) "wha iV'rr*>ua 
i-arlxiuate wa-sbed and dried with rri'e expiwure to air, the pHwlnet 
Ibus, by the id>H[ir|ttiun ol' «>xy^^en Jiiid the eleiiieuiH of wsitir; and 
the climinalioii cit' eadxniie anhyriride, bredinirig ferric nxybydrox- 
i«b\ n o*»rnp<niiid wbieb will vtmie imder iiotire stilisetitientiy. 
Kt'trtius earboiiate is miid t*) be nture easily dissolverl in the 
fttoiimeh than any other iron prepamtioiu It no viinWy oxidi/ed, 
thai it i»Uf*t Ik* WH-slied with water free trom diKsolved air, and 
then mixed witb the Bugar (vvliieb prutt^i t8 it i*r<»rii oxidatinii) im 
quickly as jKMs^ible* In makiiij*: the otlieial ciMiipnund tiiixlure td' 
irciii {Afufiura Frrn iHmpoHifn^ U. 8. I\)^ **Gnt1itb'H jidxture/' 
the prepared ingredietitH, itjeludinir the potiKHium carbonate, 
ftlitnild be ]daeed in a 1 kittle of thr nnjinred j^i/e, space briir^ left 
for the ftolutioti of ferrram sulphate, whieb jiimubl be added hist, 
tUe buttle immediately lille^l up witli the nnne^water and rtt'curtdy 
eorked; tlie ininiinnm of oxidntion in thus ensuri'd. The propor- 
tioiii* ordered iu tb<' tdfM'ial mixture are ahnost three times the for- 
mula weight of potassinia enrbouate for onee timt of terrou!* sul- 
pbati'; benee, as the ftTfous carbonate *h"eoin[io.m's, the earbonic 
antiydride produced doe-s not ueee^anly e-seape, but eftaveji^ the 
jioUiM^inni carbonate int*i biearbonftte. Pituht Ferri ('ttrbtmttfiA^ 
XT H. I*.^ /row /Wor ** Jllaud'H lill/* in prepared with granulattnl 
fernnift sulphate and potassium earlKuiate, 



Ferrous Arsenate* 
?? under Arsenic (p. 174). 



iroii Arsenate 



Ferrous Phosphate. Iron Phosphate. 



Experiment 3. — To a hot flohitlon of ferrous sulphate in n 
\eB{'Ui]H* atbl a hot solution of BoJiuiu pbo8|diate aud a mnall 
quftntity of a f^ohition of mdiiHii bit'arlMJuate ; ferrous phos- 
phate IS prec'ipitated. 



Femmn «iil|v1ifitc 



m« »iil|ihjitc 




2Nn,HPO, 



-h 2NaHC0, = 

^to(!hirii III I'll rTntiiAtc 



4^ 3Na;^0 I 
8(xlhnn NulpWlc 



2ir.t) 

Wntif 



4^ 2CO, 

Carbon io iii(l)y<Iriilc 




154 



THE METALLIC RADICALS. 



Themlditiori <tf the soiliuni liii arlxMiaU' is tf» insure the ahs^eiu-e 
of free sulphiirii' acid fmiri the sohitinii. Siil|4nirii*aH<l dis.'itilvcs 
ferrous |ihtis[»hate, iind \i is iuiposHibk' Ut |»reveut the li)M'rutiiiij 
ijfhoiiu' suljihuric Mi'iil, ifijuly the lernius su!jihf*te ami Kiwlium 
phu,s|jhate he employed witliout the.^Mliuni Inrarhouijite. Ferrous 
phiispliiite is while liut hoou hei'tiuies oxidized autJ is then shite- 
bhie. It WI18 formerly iuekuled in the Ignited States rharmuco- 
pueidi, aud is 8titl ollieiuJ in the British Pharumeopu^m. 



Perrous Stilpbide. Iron SulpMie, 



BxperimeEt i.^Mix nulphur iti a teM-tul>e with alMnit twiee 
iti^ weight ui'iroii filiugs and Btrouj^'lv heat the Jidxture in the 
BmiHen tliiiiie (or heat in nn earthen crucible in a furnaeeK 
ferrous sulphide, FeS, is lonued. When the prmhiet is eohl^ 
add water to a snuill portioti of it. and then a few drojis of 
sulphuric achi ; hydrogen aulphide, H^S, reeognizahle by its 
odor, i« evolved. ' Fe8 -f- H,SO, -- FaSO, + H,B. 

Sticks of sulphur t*reKsed ajirainst a whitediot har of cast-iron 
give ii pure ruriu of ferrous sulphide ; or inelte<l suljdinr may be 
[»oured into a cTUcihIe of red-imt iron iiiiils, when a ijuanlity of 
fluid ferrnUi^ walphide is at uiice Ibruied aud may be poured imton 
a Blab. 

Hydrous Perroua CMoride, Iron Chloride. 

Ezperiment 5,— DitreHt \nni tacks or wire, in n ie^t-ttibe, in 
hydrtK'Idoric acid ; hyilro^^eii e«i*a])eH, ami the H<dutJon on eoob 
irtg, or on evu|M»niti<in ami cooling, dejioi^its ervHtalli/ed ferroua 
chlori.le, Fe<_n,, 4H,(K 

AiihtjdroiLi FerrotiH Chloride. — St'e \\ 156. 

Ferrous Iodide. Iron Iodide. 

Experiment 6,^Place a piece of i< Kline, al»oiu the mrje of a 
peji, in a t^^st-tuhe. with a small iptantity of water, and ad*! a 
few iron lilingfl, or **nuill nails, or Huiie iron wire. Hn gently 
wanuiujj, or merely shaking if hmger time l>e allowe^h I he 
iixline disap[>ears, and on tilteriug, a clear light-green golulion 
of fernjus ioilide, Fel^, is obtained. Ou evai^ration, the 
scdid iodide remains. 

Sidid ferrous ifidide contains about 18 percent, of water of crys- 
tjdlizjdion iiud a little iron oxid*;. It is delirineseeut sirnl Fiahle to 
ah!*orboxygrn fmrn the air wittr formati<in of insoluble ferric «iX)io- 
dide or hydrtixyiodide. Ferrun iodide thus uxidisted may be 



J 
I 



FERHIV SAM'S. 



155 



I 



[»tin!ie*l by re-Holiilion in wuter^ iitlditiiMi of n little imire itKline 
iiDil srfiiue in»ii, wjLrniin^^ tVltering^ imci evaponitiu^ ti*s betort*. 
J^yrup <»f ferrouM iodiilt* {Sffriipuj< Frt't-i Ifnii<H^ I '. K P.), Una al- 
reutly been nit^ntioned (HJ p. ?J7. vSyrwp <*r IVirotis iiKliik whitk 
\in& Ixrome brown muy usually be resti^red In' iumier^iiig tkc 
btjtttt* in a water-bath anil nlnwly wanning. 

In making Pihiltr Ferri hdhil, U. fc?. P., reduced iron (.see. p. 

Fcrrouff Bromidt^ FeBr,, oceasionally used in medicines nniy 
l>e ni»de in a minilar way. Its a<dutioii in water or syrup ik light 
ga*en. 

FERRIC SALTS. 

Anhydrous Ferric CMaride. (Iron Perchlarids),^ 

ExpermieEt 7*— Pttsg dil<>rine f j]:enerate(l frrmi black mvLTL- 
gane«e oxJ<le (intl byclrucblurie acid In a Hiit^k) through ccm- 
eentratetl »ul[)byric aeid etmtained in a t^mall wa&h-btittle (to 
dry the gas) and then, by ineans^ af a glass tulie^ to ibe bot- 

VuK :^1. 




Preparallon forauhydmuN {vtt'w ihlnriilo. 



torn of a te«l-tul>e eontaining twenty or thirty ^'inall iroiitackfl 
(*>r a tiui^k eontainiiif; two or tbnr^t? ounees id' tlieni — nee Fig. 
31 )» tbe latter l>eing kept ht)t hy a gjiB-Hanje ; ferrie rhioride, 
F«rCTl^ 18 formed and ei>rideu»e» hi tbe upj.>er part of tbe tulie 

* Tbi* fircft* pft (tiiid h^per) VL9**t\ hn^rv :nid Klsi>wlit«ri* is frtim vir<f», hyper, 
I over* «tr nb^jvts iifid in ihi?. «'iislv, iiidirntc-:^ tin.' higluT I'lilorirle (if Iron; 
tliAt ii, ir*»ii |M.'rr'h1oHile i» thu iruii rlduridti wUieli cuiitaitis tlio lai^er 





166 



THE METALLIC RADICAIJ5. 



or flask as a mass of smalL dark, irretlesceiit crystals* Wlieu a 
tt»lenil>ly thick mit*t <vf the salt is fbniie<it lirenk off tlif jkirt 
of llie glass containing it, boinir careful I bat the remaiiiiiijr et>r- 
nnlefl tacks are excluded, uimI place it in ten tt> twenty times 
its weight of water : tlie resulting sulution, ixjnretl otf from any 
pieces uf ghim, is a nearly neutral solntioii of ferric chloride, 
and may he eiuph>yed fi>r analytical reactiutis. 

Prt'CfiHtiim, — The alwive exiieriuient (nust he condticted in tli^ 
open iiir, or in a innie-cuplmsird. 

Atihtfdmm Mrrauji Chhirhtr.—lii breaking up the vessel, «caly 
crysttds* of this subHtHnce, FeClj, of a light and b« IF color, will be 
otiservett adhering U\ tbc aaiK 

iVrt/t',— .Solntbm ot' H'rric chbiride gives off s«>me by drcMhloric 
acid on boiling, while a darker*eolored *H>lutiou of ferric oxy* 
chloride reniaius. 



Solution of Feme Chloride. 

Experiment 8» Through a portion of the solution offerroiiT 
chloride, (irepare«i iu experiment 5, pass chlorine gas ; the 
ferrtni:? chloride \^ converted min (err le rhioride; The escefli 
of chlorine dissolved by the Hipiid in this cxixTiment may be 
removed by ehnllition; bnt the ferric chloride is liable to he 
slightly decomjwised. (See alnjve ), The fri^ chlorine is 
better carrie<l off by passing a current of air through the 
liqnid for sonic time. 

Experiment 9, Ti> a |Xjrtioii of the solution of ferrous 
chlornle, prepared in ex|>eriinent 5, add a little hydrix'hloric 
acid; heat the licpdd, and drop in nitric acid until the hlaek 
color at firs^t priwlnrctl* disuppears ; the resulting reildish- 
brown liquid ts a solution of ferric chloride. 

8FcCl, + HNOj + 3HCI = 3FeCl, + NO -h2H,0 
Perroua Nitric Hydrochloric Feirio Nltrtc Wiiter 

cliloride Held neM chloride oxide 

The black auhstance is a comjiouad praiacetl by the interac- 
tion of nitric oxide, NO, with soim- ferrous saltj itn compos<ition 
is 2Fe80^-^NO; it i» det^onjjjosed by heat 

Li*/nnr Ferri (Woridi^ TJ. 8. P. , \n a .dilution of ferric cbloride 
preparefl by jM>uring a dilution of ferrou?* ibloride into a aulRcient 
quantity of nitric acid contained in a capaeioim vps,se], evaporatinc 
until the liquid is free from nitric acid, and H<ljnMting the solution 
wi as to contain !•> jHTcent. of inin. I volunie with H of alcohcd, 
given Jinehtra Ferri Chlondi, V, 8. P. 

Note, — The alcohol in the hitter preparation does not act cither 
la a special *w*lvent or as a preservative^ — the oiIice« usually pcr^ 




I 



FERRIC SALTS. 



formed by nlcohc^l in V. S. P. jjrcpnnitioiw — uiitl, m a nmtter of 
fiU-'t, unless the liquid loiitiiiii excess *tf arid, it ^lee<>lllp^^se^^ the 
ferric ehloride arid cim!*eH the lomiatiim tifan iri?«>luUk' lemeoxy- 
cbluride. Even if thf tiiietua' be aeid, it hIuavIv 1<»w*\s color, 
ferrous chloride and ethereiil eniinnputidji e<nituiiiing ciilt>riiie btdti^ 
fornicd. Lu/twr Fvrn (ythndi in not liuble t^j such decompoBition 
and Huch variatitm in characters. 

Solution of Ferric Chloriile, when evjijxjrnU'd, yields a iiiiiss of 
yellow crystali* having tlie einnpoaition FeCl,, (ifl^O, or, nntJer 
other conditioijj^j red crv»t!il,s repre«ent*id hv the formula 2FeClj, 
5H,0. 

Ferric Sulpliate i formerly caEed Iron Parsulpliate). * 

Experiment 10.— Diswtdve ahoiit three-quarters of nn ounce 
of fernjua sulphate and iiliout a fiflij of this weiL^ht of syli)huric 
acid in an ounce and n lialf of water hi tin evu[H)ralintrHli,'^h^ 

Hhig the mixture and dropf>iu|f in uitric acid until the 
ck color at fir^t produced^ dieapjjears, Tlie re»vultin|^ 
liquid, when made of a certain (irescrihed strength, is stdnlion 
of ferric sulphate {Litjuar TrrstifphittU, U. S. P,)» a heavy, 
dark-red liquid- 

6FeK0,-h 3H,SO^ + 2HN0, 

Fi;rfim)i Solphiiric Nitric 

siit|)liHte ncid lie Id 



3Fej'80;), + 2N0 -f 4Hp 

l^^TTk' Nitric WHier 

BliljjLmtc oxido 

The black color, ils in experiineut 9, m due the formaticiii of a 
coDipound by the Loteraction of ferroui* »alt with nitric oxide. 

Ferric Hydroxide aed Ferric Oxyhydroxide, 

Bxperiment 11. — Pour a [lortton of the wjlntion of ferric 
sulphate into excels? of ammonia water; ferric hydroxide, 
Fe ( U H i ^, Fer ri Hijflroridu m, U , 8, P, , i s prec i p i t a t e d . Wn^h 
the precipitate Uj dee^nlation or on a filler, ami dry it on 
a water-bath; ferric oxy hydroxide, Fe()(OH ), remains, 

Fe(80.), + 6NH/)H 2Fc(0H ), H- :i(NH;),BO^ 

Fcrrk Amtnotkfa K<Trlr Atutiioniiim 

iful|»hiile wrttcr liy«lro%ido «y^|»1mtc 

Fe(OH), ^ FeO(OH) -{- Hfl 

Fcrrle ijyijruxldo Ferric (»xyliy*ln>3il<k- WiUer 

Either of the other alkalies (caustic pota^^h or mkIu) would pro- 
' a similar reiu'tion. 

_^ The amnr porstitplinte cannot now be applied eonsist«*ntly to this 
tnlMtiiticv. Th** pfrmifpkate form a di^fluH* »i»nes <if salts derived rn>m 
piif«utfihuric urid, IIjS-0«. F^rHr Hulphnte is s»iinply thp milphHU^ cor- 
rteipoiidiiifrto th<^ higher basie uxidt* nfinm— ferric oxide, Feifh, foniierly 
calkd ii««i[|uioitdcp iitid tjomciiiijcs pvruxidc, uf iron. 




158 



TUK METALLIC RADICALS. 



Ferrie hydroxide is ati iinHdote in aiRe« of arst^niuil p(iii?tming, 
if a*huiiiistt^rt'(l cJinTtly aftor the jioision hiin Iutu Uiken, It cou* 
vert!^ the Holnblu jirseuuiis* ai'iii, H^Astlj, into ins<jluble ferrwiiR 

4Fe(0II), + 2H,AMA - Fi^,(ABU,X Hr HH,0 -f Fi'(OH), 
Ferric hydroxide becomes converted into <>3cyhydroxi<le, when 
dried, and ha^ then Itrsn aetioii on the trriM?ni>ui4^ iieid. Even the 
raoist recently f>re[nired hyiln»xide lo^+'s nnirh of its aelion lis Hi*on 
lis it hti.H rhan^-ed into onv of the oxyhydmxidei^t, Fe/ ^^(OH )^, a 
djiMij,^e whirh will oeeur thtmgh the hydroxide l)e kept under 
water ( W, Prot-ter, jun.). Aeenrding Uv T. and H. 8mith, thia 
deiv.njpmition occurs jj^rathially, but in an increiu^ing ratio; so 
tlnit utter tour inontliH the power of the unnst mas* is reduet*d to 
one-half and afu-r liv*^ months t4» one-hmrth. 

A ferrie oxycarhohydroxide, Fe/XHgt*H)^, has hepu obtiiinccl 

Ferric Oxide. 

Ferrie oxyhydroxide, Fe4)(()H), deeonipis*^ when hcatefl 
to h>w reduess, ferric oxide» Fe^O^, remaining, 

2FeO{OH) = Fe,0, + H,0 

Eatperiment. 12. — Roajst w erystnl or two of fernjus j^nlphiite, 
inixcil witb ii Btiiull <|iiantity *d" sulphur to uid the re^luetion^ 
in a »nuill ernoible niitil fnines are no h>njt,'er evolved; the 
reJ^idue in a variety of ferric oxide, known in tm<l8 a** red 
oxide of ii'otu <^oh'ijth(ii\ crocus, mitifntf inafje^ Vcnefinn retL etc* 
Jt Ikis 8ometimeM been n^ed in plifinimey in mklnke for the 
oxyhydpixides, from which it differs not t»nly in iHMn|josition 
but in the iinjiurtant re^i^ect of being almost insulubie in 
acids. 



Ferric Acetate. Itoe Acetate* 

Experiment 13, — Digest recent ly-|>rej>ared, washerl, and 
drained ferrie hydroxide in glacial act^tic arid; ferric acetate, 
Fe((*Jij()j)y is produeed:^ — 



Fe(OH), + 
Ferric bydnnlile 



3HC,H,0, = 

AcctJic Meid 



Fc(C,H.O,), 

Ferric aretntu 



+ 






Tlie "Scale" Compounds of Iron. 

Experiment 14. — Repeat experiment 11, rntri>ducing some 
dolntion of eitrie or tartaric acid or of iHitaHsinm bitartrata 
into tlie ferric sulphate solution before adding it to the alkal 





I 



FERRIC SALTS, 



159 



ustic iMwla^ caustic potash, or aiMTnooia)* and notice that 
DOW no (irt»eipit4iti*Mi of ferric hydroxide occurs. The iion- 
j»roductioQ of precipitates is ilue to the toriiiatioii of duiilde 
coiii|X)Uiids, wbich remain in litdutiou along with alkali-metal 
sull)hate, 8urh ferric compounds, made hy mixing certain 
pre-^*rilic<l projjortioDS of recently prepared ferric hytlroxide 
(from which all soluhle sulphate lias heeu removed by wai?h- 
ing), with the respective acids r tartaric or citri<v) or acid salts 
( jjotaififiium hitartrate), etc,, evaporating the H>tutioris U\ a 
syrupy ennsistenct* and then spreading on sm<M»ih plates to 
dry, form scale pre(iaralion8 siuch as Fern ei Ammunli Citnis^ 
U. S. Po and Fttri et FutiUMt Tarira^'<, V. 8, P. A mixture 
of ferric citrate with ainmonium citrate and ijuiuine citrate 
yieldft, l>y similar treatment^ the welUkuown muluB ot* Feni ct 
Qulninm Citrus, V, 8, P. 

SiJt^^^'iajens of these suhstunees may be prejtared hy atteiidinjj to 
the tViltowing deUdh. Iti.*^ es.s4.iniui, (irst, that tlje tirric hydrox- 
ide be th*ir*)Ughly \va.shiMl, or «n iafW)Uil»le oxysulpliatt' will be 
finrnied; secondly, tluit the ferric hydroxitle l>e rnpidly w^ishrd, or 
mi iasolnble ferric tjxyhydroxide will be jmHiaced; thirdly, tlnit 
the whole operation he coaductcd rpiitkly «ir reduction to jrreea 
ferrcjus nitlt will *iccur; fourthly, thsit the solutioas of the Ksdis be 
not cvapc^rutcd at a high temperiitnre, iir tUM'oin|MKHit4>n will tiike 
place; and, hftldy, thM cxiesM of ferric livdroxidi' tie eaiployed. 

In nuiking ihe sciile eoaif^ounds^ the ferric hydroxide is in each 
caiM.* fn-i^hly made fnan solution of ferric sulphate by precipitation 
with ammonia water; — 

Fe,f*S(-),), -f 6NH, ^ 6H,0 = 2Fe(0HX -f 3(NH,), SO, 

Ferric Animofiia Ferric Animonmm 

BUl{iliiilii wattif hydroxide sulpbuHc 

the ftfihitiou of ferric sulphate beiaj? nnide i>f a definite concentra- 
tion froai a known weight of ferrous sidphate* The reason tVir 
mlopting this course is, thiit terric liydroxide cannot be dried with- 
out di>c** mi posing jmd lMx-omini_' insiduble an exjilained on p, lo8j 
and tben'lore caimol be wei^djetl. This dehnite sidutiou of ferric 
i^ulphiite (Liquor Fcrri Ta-rniphaiiA^ U. S. P.), is nmde an already 
di-s<'ril)c<i. 

Frrri ei Amrttittiti fHtrrts, U, S. P. — Ferric hydroxide is dis- 
till ved in st>lution of citric acid, ammonia water added, and the 
whole evaporated t** dryness. 

To prepare the ferric hydroxide, dilute U\ flaidounees of the 
above stdution of ferric suljihate with about aijuart of water; i»oar 
lhi» into 2 pint^ of water e<*hlainin>r excess of aiiiTnonia ivnter. 
(If the opposite c<mrse were adopted^the alkjdinc ijipjid f>oured 
into the ferric solution— the precipitate would contain ferric oxy- 




160 



TliK METALLIC RADICALS. 




«uI|»1]hU", c>r hyclroxvsuiphiite* whirh int4erfer(?:4 with the brill iancy 
of the 5M.'ak'.s. '^ Thi>r««Ujj:h!y stir ihi* mixturL^ (it will Kdiell stron|rly 
ofaniijuinia iJ'tnKmgli nl tho latter hius bwn u^i^d), ullnw thr pre- 
ciititiitf tt» sukHidt*, pour iiWrij the .superiKiUrjt Ittjuid, add more 
water, and repeat the washing until ii white precipituti* of btiriuin 
sulphate is no lonjjrer produced on the addition nf wdution of tm- 
riuni chloride or nitrate to a little of the washings. CoJk'et the 
ferric hydroxide on ii filter, drain, and add it, while still moist, 
Ui a scdution ul' 4 ounees of citric acid in 4 of Water, pliieed in an 
evaporating-basin on a Wiiier-hatli ; stir frwpiently, until nearly 
the whole of tht* hydroxide has dinsolved, or until the acid is 
fully saturated with the hydroxide and wjuie of the hitter remains 
undissolved. To the mixture, when coldi, add 5J tluidoiinees of 
amniunia water, tilter, evjiponite on a water-bath to the consist- 
ence of syrup, spreiwi thinly on sheets of glass, and dry (at u 
teaipt-rature not exceeding 100° F., :-{7*8°C.). The product acalcft 
off the glass in deep-red tran>^pa^ent laminie, 

NoU\' — The ehemical composition of ir<m and ammonium citrat4? 
is approximately FeO^NHJXVH/),. Compounds which exhibit 
an analog^' in enrnposilion are found in bismuth and ammonium 
citrate, Bi()(NII^)/.y f^O., and antimony and potassium tartrate, 
Bhi)KO,H,(),. 

ftrri ft Qmnlnff Cifras tSrdubilU^V, B, P, — Ferric hydroxide and 
pure ijuinine are dissolved in solution of citric acid, ammonia 
water :id led, and the wliote evaporated t<j tlryncss. The product 
contains ferric citrate, ipiihine citrate, and sunmonium citrate* 

The ferric hydroxide is obtained from \) riuidounces of the 
milntion of ferric 8uiphate, with all the precautiotm dciicribed 
under Ferri ft Ant won In Off nut. 

While the ferric hydro xltle is being wiished, prepare the qui- 
nine by disMrdving 2 laint^es of quinine liisul[»hate in 1<> ounce** of 
distilled water, and to the clear liquitl a(!d amin^aiia water, well 
mixing the jirodurt by stirririg, until the whole of the cjuitiine w 
precipitiited (this is the case when the mixture, al\er thoniugh 
agitation, smells of ammonia). Collect the precipitjite on a filter, 
let it drain, and wash away adhering fvdution of ammonium sui- 
phate by passing through it about three pint» of distilled water. 

The ferric hy<lroxide and quinine being now washetl and 
drained, disi*<dve the former, and af\erwarfl the latter^ in a solu* 
tion of G ounces and GO grains of citric acid in an e<pial weight of 
distilled water, the acid liquid being warmed on a w^aler-balh, and 
jMirtions of the preeipitate-s stirred in as fast aawdution is efTcM'ttfl. 
Let the dilution cool ; add, in small i|nantitie» at a time, 3 lluid- 
oiinecii of ammonia wat^-r, diluted with 4 fluidounce» of dis- 
tilled water ; stir l>riMkly, allowing the quinine Avhich Hcpanitea 
with each addition of ammonia t** dissolve befort^he next addition 
IB made ; BltiT the solution; evaporate it to the consistence of a 





FERRW SALTS. 



l(il 



I 

■ 

I 



iWxn j^yrup; riry the lalttr m thin layers on flat poR'elain or glass 
(ilnk« At a k^m]ti'nitnre *jf KKJ*' F. (H7,H'*(A); reniov^ the dry 
««('iUei^ of 8<>luljle Ivmi ami t^ninine Citratr. Ferri H Quiiiimi^ 
(%ira», U. S. P*, is a Himilar^ but a^nm-what le*8 readily aoluble 
preparsitiiin. 

Fcrri ff Pota^ii Tariras^ U. 8» P. — Ftsrric hydroxide is dii*- 
aolvetl in !K)lutioii of potafiaium bitiirtrale, and the wliule evapo- 
raU'd U} drjtn*88. 

The ferric hydmxide iibtaiuable from 10 fluidouncea of the official 
solution of ferric sulpliatit by the ai'tinn of ammonia, in the 
manner detailed nnder Ferri rt Amnumii Vifrnjif is niixt^d (in a 
jKircelain dish), while ^till moist Ijat well drained, with 3 ounce** 
and 14*1 jL^rains of potassiuai bitartrale. The whole is !*et iv^ide for 
about twenty-four honrM, and then heated on a water- bath to a 
temperfUure not exeeediiif^ l4iP F. (6(J'^ C); a pint and a half of 
diiatilb'd water is then atlded» and the mixtnre is kept warm until 
nothing more will dijisolve, filtered^ evapt)nited at a tt^niperature 
not exceeding 140° F. (<i(>° C.)^ (greatt^r heat canseHdeeompo«ition), 
and when the mixture hit^ the conHistence of syrup, spread mi 
fiheets of ghi.ss and aliowed to dry (in any warm and open place at 
a temperature not exceeding 10(>^ F., t^l.H"^ C). The dry jialt i;* 
ihua obtaine<l in stales. It yhould be kept in well-elowed bottlej^. 

In the United States Pharmacupceia /vrW T/Mm, Ferri ef Sfri/ch- 
nimr (.Vras^ and Fcrri et Afiimonii Tar/raji are included. Ferric 
citmte di«3olveH slowly in cold, b'lt readily in warm wat<*r. 
Ferrir plimphate^ FePCJ^, when freshly prccipiUited, is i^oluble in 
sr>luf iont) of eitrate>i f>f the alkali-rjietalH, and t Jxe solutions fin evapo- 
ration on glaMw plates yield neales. Ferri Pho^phas iSftlufiifiM, 
V, S, P,, is a prenaration ttf tlii>* kind : it may 1m> obtain«'d Ijy the 
int^mction of 8o<iiuni phosphate with a »<dulion of ferric citrate 
itnd eva|M)ratii>ii of the solution at a temperature which nhould 
not exceed HO** F. («>()'' C). Jt forma thin, bright gre<'n tnuis- 
parent «cjilea. Frrri Pf/rop)i^nph(i4 sS^tiuhiHn m also official. 

The foregoing are the olFicial »cale preparations of iron. Many 
nth(*r* of similar character miglit l)e torined. Few of them crys- 
talliKT or give other indicationi^ of definite chemical eomiM>*<itii>a, 
Their properties^ arc only constant m bmg as they are made wilh 
unvar\'ing proportions of the constitiienti*. A crystalline, /rrroujf 
tarfrnU, FeC^ll^O^, and an aeUijWrum ctfrafr^ FeIi(_\H/_>,, H J), 
Imve been obtained l>y the interaction i^f irt>n and the resfK'c* 
tivc acidjn iti hot water. They oetiir as while gritty musses of 
micro*»cojiie crystals, A $o(Uti-fermu^ nfrnte, tVNat'^Hj^t)^, and 

trtiTyritrnte^ FeC)HNa,0(jH^n^, may l»e obtained in sealr^. 
HV'rt*' o/ im«, or "Steel" wiijc {Vinnm Ferrt^ V. vS. P.), is a 

ItiLion of Ifcin and A mmoninm Citrate in white wine, with Tiiic- 
iuw of Bweot Orange Peel and Syrnp added. Bitter Wine of iron 
i ilttum Frrri Amaru ui^ IT. S. P,), ia a similar solution of »<ohd}le 
iron and Quinine Citrate. 




162 



THE METALLIC RADICALS. 



Ferric Nitrate. 

Experiment 15,^ — Place a few iron tiicku irulilute nitric acid 
aad eei midn] s*>lutiou of ferric nitrate, FetNOj)^, is formed. 



Fe 

Iran 



+ 



41IN() = Fe(NO,)5 
Kitric Held Ferfiu nitmlti 



4 



1^11,0 -^ NO 
W liter Nitric oxide 



FiTrif iiitriik' and frrne uiTtute unite If* Jonn various iicrlo- 
nitntti's, suiNOi^ whicli i^ onu hitviii^j^ tlic formula FeXC\WsOJ, 
NOgOH, 4H,U, aud crystallidug in hard, t^kiiiinj^ browniiili-red 
prisim^, 

, Beduced Iron. 

Experiment 18. — Pass purehydnigen (which has been»1ried 
by |Mii*?<iiig it over [licci^s cd' erdciuni riilt»riile roiitaint^d iu a 
tuhe or through ^aljdiiiric acid in n wii«hd>oltle) over a muall 
t|uantity of ftirric oxide, Fe^O^^ or ferric oxyhydroxide, 

Fia,32. 



Pn^paFftUon of reduced iron, 

Fef OH ), couiniued in a tube place^l horizimtaMy, the powii 
UiHUi: kept h(»t l>y a ^ai**fl>ime ; oxy;.n'ri i?* n nioved by the 
hydrogen, j^tcam eRajn^'Hat llicojM^n end of the rul»e» and after a 
t^liort time, when moisture ceaf^es t<» In'ovolvf^d, metallic iron, 
in a state of fine division, remains. (Sre F]g. 32.) 

311, = 2Fe H 4H,0 
n>'dr*»jion Iron ^^al('^ 

Whik' M\][ hot, thnvw the iron out into the air; it takes fire 
aud falla to the ground m magnetic oxide, Fe^O^. 

If ferric oxide 18 reduced in a «troiiply-heated iron tulw iii n 
fumtice, tbe particles of iron aggregate Ut mme extent, and. 



2PVO(OH) 
Ferric oxybydruxldc 







RED WED IRON. 



\m 



m eu](l, itro only slowly oxiciizt'd in tlry iiir. This hiller form 
of redufeil iron iis Fet' rhluit, or f/iitvennt''» /ron^ the Fertipttivij'f 
or /IvTwrn Roittrfum^ U. H. K — *'ii vury tint: ^:myis?h-hl;uk lustre- 
lea* |»owder, withnut oflor tit liusttv.'* It is oft^'ti admiriiiSltTrd 
in ibf iVirin of ii lozen^'^c, gum an*l ftiigar |»n*tceting tin.' iron from 
ojtiilaiion ii» Wi'll its rorniiiig a vi-hiili^ for itn sntininiBtnition. 

Notr, 1 — Tbi* ,spt>tJtimeous igiiitiun of tlie iron in tlii^ iiUove 
exjierimc'iit is uii illustration of tht- lutlnLnRv of ininiilrdivisiuiitai 
tliL' occurrence of chemii'al change. The action is the fc^anie as 
that which occurs when iron wire Uurns (an it do^s with great 
brilliancy J in oxygen. The surface exp^ed to tlic action of tiie 
oxygen of the air is, in thf ease of thirf variety of rednced iron, sfj 
eijomiousi coniyiared with the weight of the iron, that the heat is 
not coniluct4.^d away ^^ufhcicntly fast to prevent elevation of tem- 
|x?niturc t*! a point at which the whole liceoiiies incaTalej<eent. 
The ndxturc of lead and earhoii (h»ad pyroj>hf>rus} resulting when 
lead tartrate is carefully I tea ted in a test- tube nnli! fumcM cease to 
be evolved, spintancously ignites when thrown into tlie air, and 
fur the same reason* Many milistanees, solid and li<juid, if liable 
to oxidation^ and nutJiciently finely divided, and especially if ex- 
[K»m.Hl in a warm phu-e, becoinc htA anti cveti occasim^ially burst 
into name spontimeoiisly. Oil on cotton waste, powdered ehar- 
ciml, coal (cHpccially if jiyritie, porous, or powtleredi, robins iu 
powder, and even tlour ami hay, are fannliar illustratirais of 
tnateriah liable to "heat/' or char, or even burn spontaneoasly. 
Nf}tr 2.— The student who hat* time and o[*portunity t^i do s<j, 
in advlHifl to carry out experiment 16, a>* a roughly quantitative 
one, by way of realizing what ha^ already been stated (sec Lairn 
of Cheinivnl O/mhhutfitm, pp, fil, r)2), with rei?jiect to chemk'al 
jicti(»nB, that they tiike place between delinitc weights only cd" 
itiatU^r Three tubes, simihir to the oxitle tuhe shown in Fig. '^2 
(or three U tube^), should be preparer!, the second being con- 
neet<»d to the first, and the thinl ia the .sect»ml, in the UHunl man- 
ner by means of Inilia-ruidiiT tubing. The first tube should eon- 
litin pieees <d' esdeiuni ehli*ride in absorb any traces of moisture 
not retained by the siiljiluinc aeid. The .M*eond tuijc (the ends 
of thesmati tube being temporarily eh»s<.'d by snudt corks) should 

I Ik* weig^bcil in a balance whieti will turn uitlj a cjnarter of or lialf 
fi trnnn, and, the weight havinji: Ih^cu iioted, ir>** j^rains of dry 
firric 4ixide should be neatly phiccMi in the middle id" the Iu1k*» 
(The oxide, bef(»re Wing weighi'd must he heated in a snndl 
enieible over a Bunsen llame to convert amy ferric ox v hydroxide 

'. into ferric oxide, and to remove all traecs of moisture). I'he third 
tnlic should eontjun piece>4 of caleium chloride tr> al>t^orh the water 
f i^ hI u ce« 1 i n t h e reae tio n , ami -should he \% e i g he d j u st 1 >e f< jr< ^ 1 k- i j »g 

► connected. The operation is now carried chjI, At its cl(»se, and 
whrn tlie niiddJe tube ii* cold, the latter and the third tulie arc 
agam weighed. The oxide lul>e should weigh nearly 48 (47, G4) 




H>l 




THE METALLH: ILIDICALS, 



grains le^H liian iK'fore, and the cjileium chbiride tube nearly M 
(53.64) grftin^ more than befure. 

FeA 

(111-1-47,64) + 

The oj>eratii>n h eninpleted more «juiekly if nae-hiilf or one-lourth 
of the weight III* the ttx'uh^ hein^ tjiken; in that ea^si' one-half or 
< irii> fourth of the weijrhti^ of irtiii and of water will he iihtaintHj, 
Itiilw^d any weijudit of tjxide may he employee^ the amount of ir<jn 
nm\ water resulting will he nlwa*j» ^vaHly proportiount^ to the 
vvei^HilM jiiMt mentioned, provided the whole of the ferric oxides 
is reduced U) iron. 

Analyiieal Rt-acthna of Iron Salts. 
Reaetiom of Frmms Sfdfs, 

L PitSi* hydrogen au1|>hiiU% H^S, through a solution of a 
ferrous Fait U\fj., ferrou:^ sulphate) slightly acidulatt^d with 
hydrm^hlone neid ; im [ireripitate is* prtMiuced. This is ti 
vuliiahle negalive faet, iiswill l>e t^videut ]>rei5^iitly* 

2. Add aniuioniuin hydrfisulphide, NH^Sll, to solution of 
a ferrous salt; a black |>r©ei[Htiit*; of ferrous sul[ihide, FeS» 
h prodaeed. 

FeSO, -f 2NH,8H = Ft^ + (NH.VSO, + H^S 

3. Add soliiiioii of [lotasaiuni ferrocyanlde (yenow prus- 
siatr of j«itash )» K^FeC'^N^, to a iiolutiou of a ferrous salt ; a 
pale blue prwipitiile is prorluoed, whieh rapidly l>cyx>iuca 
darker blue owing to tibsorption of oxygen and amversion 
into Prussiau blue, {S<:e ]k 105.) 

4. To a solution of a ferrouB «t!t add fMjtaasium ferricyan- 
icle (red jirussiate fif pitaHb ) K^FeC^N^: a dark blue preci[ji- 
iaie ispn»ilueeilof Ttirtd)uirs blue, resejtihliug Prus,siau hlueJ 

Other Analytical Eeactions. — The ]n'eci|iitates prcnluced 
from ferrous solutiotis on the additifjn of alkali-metal earlnm- 
ale-s jihosphales, aii<l arsenates as already descril>ed in the 
ex [^erhneuti^ dealing with the prejMi rat ii»u of the corresponding 
ferrous salte^ are fharacteristic, and lienee have a certain 
amount of analytiail iut^rest, hut are inferior in this re8|iect 
to the four reaetioiis above nientione<l 

»rv»iit»|i«'ii f<'N'. <»rrv'), ferr^iryAiJiiKcn f Fi'( "4^11"'', i^r Fe(*y«"*') »"d 
femcynnotfrii rPVC«N«'''.or FcCVft'") arc nubnils whicli pky the purt of 
tion-nu'tunit" elomi.'titxJfiHt jtsHiinuntiiioii in il»rliciiiiad relations 
blf<Htlie luuUlUcelL'tnerits. Thtry will be reforrtHl tuagniiK 






FEItnoUS SALl'S. 



liio 



Note, — Solution of jiriuiiiiiii^t, ami sulutiniis nJ' L"uu>?ti€ iKihi&h 
ftiid jwhJh ill presence of iiiiimniiium siilts, are jjuompU'k* jinripi- 
tauU of t'orrtm.H khUs. To a solution of a Ti rrous salt ad<l aiiiioa- 
nia; on filt^^^rint^ oil" the whitish l^rmus hydn^xiilu, ami test in;; the 
filtrak^ with aiiiLai>nitiio hy<lri»sul]iliide, iron will Htil! be foiind 
in dilution. To jmotlier portion ot* the t'LTnais nulntion a<]tl a few 
(Iropirt of nitri*.' arid, or exeejM of chlnrine water, and hoil; this 
i'ojivertH the fernuis into terrie rtalt, jiiuJ alkaUi.s, iiirludiiij^ ammo- 
nia, will now preci[Htate the iron t'oiaplettly irs terrie hydroxidi^ 

In aetnal armlyHis, the sfparation of iron a8 ferrie hydmxide in 
an oj>eration of frequent ( ►erfo rmaneej*. Thin is always accomp- 
lished by the addition of alkali after (if the inm oeeurn jw a fer- 
ri>u>< sidt) previous ebullition with a little nitrie aeid. Potiusi^ium 
ferroeyanicle anci ferrieyauide are the rcji^euta most commonly used 
in disiinguishiag ferroius from ferric salla. 



I 



Eeacthns of Ferric Salts, 

1. Through a iiolutkni of a ferric salt (e.g„ ferric ehloriile) 
|Wi8s hydrogen sulphide; a white pre<!ipitiite of sulphur [from 
th* hydrof^eu Kidphide), i^ prudueed. The ferric salt iw 
simulUineotisly eonverted into a ferrous salt, tlie latter remain- 
ing in 6i)lutioii. Thia reaction is of fre<]uent occurrence in 
analysis :— 2FeC:i, -f H.^S :^ 2FeCI., + 2IIC1 + 8. 

2. Add jiHinionium hydrosol|ihide to a fsolution of a ferric 
flak ; the latter h re<liieed to the ferrou.H state, and a black 
ftul)stiinee (ferrous sulphide, Fe8) is [ire^ ij*itated as in the 
8ei*4ind analytical reaction of ferrous «a Its, sulphur being set free, 

3. To ft solution of a ferric sjilt add jK^iassium fernwyauide, 
K^Fel/^N^; a precipitate of Prussian blue (the welbknown 
pigment), is prwJuced. 

■i. To a solotiun of a ferric ^It add pitiisi^ium fcrricyariide ; 
no pretnpitate is produced, but the litjuid assumes a dark 
brownish red color (or a greenish olive hue if the salts are 
not i:|uite pure). 

5. Add 8<^Mliuni hydroxide or ammonia water to a sol ul ion 
of a ferric salt; a reddish-hrown j)reci])itate of ferric hydntx* 
ide, Fe(OH),, is prtKbiced (com pa re experiment 11, p. 157). 

Other Anal3rtical Reactions, ^^:» me of these have i>ccasiotial 
interest. In rieutnil ferric soUitious the tannic a<id in aqueous 
infusion of galls f>ccfisions a Irluishddack itiky precipitate, 
thehasiaof mi>st black writing inks. — Potassiuui thi(>cyanate, 
KSCN, causes the rorniatiou of tVrric thiiMvauatc, whicii is 
of a deiep hhwMl n'd color. The color disapjK^urs cm the addi- 
tion of mercuric chloride. 





1(JG 



Thert* is no norm si 1 i^rrir cMrhormte; alkali-nietal (iirhou- 
txh's €!HiHe tfie |*rer'ij>itnlitin uf iLrrlr hydroxycarhoiiute while 



QUESTIONS AND EXERCISES, 

Njunc. the nhk-f ort's urinjiK— lli>w is Uit^ tintal ohtahKtl rroni the<ni»? 
— VVhtil in th<< ilif'tiiiiul ilifri'n^iire lietwoeu m.st-irun. wrotigtit-iroii, and 
Btrt'l ? Ivxplaiii tin' prtR'CH'* nf *'wt^l(]liii^/' — Wluil Isiha iiuttiro of chiily- 
lH?^*tc' wiitiTh? -liliij-lniti' l»y forimilK' thu flitlVrtMire bcstwceii ferrotis and 
fi-rrir ruILs. — Wrik^ a pMni^n aph mi tht* tumiL*iu'l:itiiri' of iron salts. — Gi v»? a 
diii^irwui of tin* pnwt'jis forllu' iirfpuratirJii of f^rrojm Mil];)luili^ — Jii what 
r«".H|H'cL>< do tilt' oHlcial Ferrous Sulphjitt- aiu! Exsit-csitetl Ferrous Sulphate 
difl'tr'^— Hinv is ft^rn»iis sulphatL- f}ht;iiried on tlielar^e scale? — Give the 
i'luMuinil iiiinu'S of wliite, green mid blue vitiiols.— Why does ferrous sn I - 
pliiite hteonie brown itn exposure t^tuir?— Hei»re?it*nt l»y Jiri equation the 
forrniitiiHj of I-Vrnms CHrboniile. — IK'Scrihe the uiiion of utniospherif: oxy- 
gen on ferroiiji earhouate ; vnn the ertVct he |»reVfnled ? — In whiit urder 
won III ymi mix the inffreilientr* tif Miittura Frni f 'oMi/^fj^i^i, iitid ^hy ? — 
Niime ftnirirwfi compounds whieh may he foroioil by the direct unkm of 
their ek"Ou»iiL=% — Givetheijflieisil method for the [irefiamlion of Sthjtion 
of hVrrie Chloride. — llowimiy Ferrous be converted into Ferrie Sulphate? 
— WImt IN the fonntdaof Fcrrie Aeetute, and hciw is it im-ptired V— Mow 
diws Ferrie IJydroxkh> aet jls an nntidi>te in arfHeiiieal ptiiujriinjf ?— What 
are the pro[vertieH of ferric oxide? — What are the penenil ehaniett-rs and 
Tingle t»f prtmluetion of the niedieiiml scale prepamlioin* of iron?— ^livo • 
diti^nim showing the formation of Ferrk Nitnite.— ('lileulate how much 
ferrie oxide will yield,, theoretieally, one hiiTMlredwei^fht of iron. Awt, 
IW lbs.. ap]iroximati'ly, — DeKcrilie the action of eueh of the followinjf re- 
a^tMits (»n 5Mihition>iof iron Wilt^, distinuuisliiii^j between fernrtisaud ferric 
re4icthm<, mid illoKtratiiig eiieh of the r<-aetioivs by an ef|Uation :— o. Atii* 
moniuiD liydrciHijlphiile. h. Potaesium ferpocyanide, e^ Potasshira ferri* 
eyaiiide. d. Caustic AlkalicH. f. Pota.^siuiii thiocyaniite. — Beiienhe Ihft 
artioTi of ammonia wiiter on sa1t« of iron, alymitiiiiin iiiid zinc resiH*c- 
livoly» 



CHROMIUM: Cr* Atomic weight, 51.7. 

0/r«rr<*ttr^,— The diit^f ore fjf t'hrritniiitn U ehnmio ironstone, 
FeO,CV;f>^, efiromiff^ ♦K'ciirriti^ chvt*fly in the United Statt*?* Jin<l 
in Sweden. The metn! may he isolated hy the ni'tirm nf tdunii- 
niiiiii on elirmnti* oxide, CY.O^, at a very hi>rh teni[ierHture. 

( 'hrotriinni fonriH H^tB of rttill^ eorre.s|n»n{hnj^ t+i ehmtnous imtl 
elir»Mnie oxrtles, i'rt) «nd CVJ >, R'j^jkh tively, hut the chnmjous 
ftiilU are exee<dirtp"ly readily ronvert<MJ \iy proeei^st-s of tixidiition 
into ehruniic widts, antl ejui only l>e prepiire^i itnd prewtTved with 
dillieulty* The ordinary' imlts in whirh rhrotniujn pliiy^ the pnrt 
tif the inetMlHe nidicah ^ire the ehr«»niie kuIu^ Mteh an chromic 
chloride, CrC'l, ; ehronitc sidphate, C'rj80J, ; ete. C'hroniitim 
nho forms an acid anhytlride, chromir aithi/tfrliir^ CK>^, ancl the 
bt*»t known ehromium comjicutitlH — the ehrutnuU^s {e,ff. , [xitfi^ium 




CHROMf ('}f. 



1G7 



t'lircimjiu% K^Crt)^), ami lUo tlielinniiuli w nr anhydroclirorimtes 

tht* chnnriiniii fonnH n part of tht- t'(»iii[*l*'x iu-jil ratlicjiln (.*rn^'' 
ii(i4 t>,0/' — Jilt' rellTriMl t^i the tirikuown rhroiiiir nvh\ [H./JrOJ 
nii*l aiiliyilnHljrtiiJiic iici^l [H;j('r_,0.], t*i>rrts|yoml!nj£ to lliis iiiiliy- 
dride. Must iif the coniitNiiiiT ibroti^iiiin cf^iiipnuiifiH are ohtiiintHl 
frcirij potsis.siii[ii dirliromnte. 

IWfHirafmfi of PuftiJ^Amm I>i*'hrounih\ — On njiLstin^ powdercii 
d»romr iron on* with poUissium tMrlMumto and nitrate, yillnw 
fHitjisaiuiii fhrfini!iti% K.,t*r(*^, i?i iihtuinrd; the inttKS, treated with 
lieid, yielcli^ red jwtas.siyin dichroniate, K./'rO^, IVllj, nr K/^r^O^ 
(fhitUMii iJirhromas, U, 8, P.) : — 

2K,CrO, f 2HCI = K/>,0, r 2Kr'l i Up 

From ihiH, other ehronlflt^^s are prepared, and, ^iy reduetiuti, as 
preHerUly exphiiiird, the elirouiie HJilts. 

Hefited strongly in a eriieihle, potuHHiiiin diehroniate s|ditfi up intii 
iMilaHsiitin chronnite, ghstening green ehrfaiiie *>xide, jin«i oxyp^n, 
4K,(*r,0. = 4K.Cr<>4 ^ 2Cr.j()j ^ '.iO^. Aiiunoniuia diehroniale, 
when heated yields si.*veral timers its v<jluine r>f lihiisli-jrroi'ii ehri*hne 
cixiiJe, water, and nitro<((^n. (XHOA'r/), = Cr/*, I ^li^tO r N.. 
The yellow and oraujie le:id rliromati.'«(lead ehrotnate PhCH >|, and 
hjwic h*nd elironiate, IMi^rK^rfJ^), are nse*l as pigments. 

ihUt^innm Chrfuntifr. — Theaoraial c>r yellow potaHsiuni ehroniate 
if* olitiiined on adding iiotussinni hiearlMmati% 200 grairii^, in Hniall 
(pianti{ie<^ at a tinje, to a hot nolutioa of the tlk hroniate, about 
295 grains, until eHerveMi*enee cea^ses, 

K,Cr,0, ^ 2KIIC0, =: 2K,CrO, + 2C0, + H,0 

For analytical purpfjws srilntimi of a nnrmaf vhromnff is ntill 
more n^adily prepared \w sini|»ly ad(ltn>r ainmoina ivater t4j a 
wjlution of potiLsHJum dii"hn>niate, until the liquid turiH yellow 
iindf after Atirring, Kuiells td' ammonia. 

K,Cr/J, -h 2NH/>H = K/;K), I (Nir,),CHl, f- H.p 

Coni^rsion of a ehnftnttit' (hi whirlt cfirnmittm fonn)§ fMtrt of 
an nvhl radiraf) tnlon rhroftitc ^tfjt { tn trhieh vhromutm ii fht^ 
mrtatlic radiraJ). — Tiirou;rh an aeidulated solution td'[H>lust<iiHn 
(liehrornatc pi** hytlrogen snlphitle: ?^ulphiir i^ depo^sited, and 
ft green ehrouiie mi!t renmins in stdnti^in — ehnmiic chloride, 
CVCl,, if hyilrtK'hlorio a<dd be tist^l, and sylplmte, Cr^fHO^)^, 
if jjulphiirio J>e the aeid etn|>loyed. Boil the li»pild to expel 
©xc^'JKof hydi'ogen sulphide, filter, and rwerve tlie H<ilution 
for j*uliw;'4|tient ex]>eninents. (Koran e<pinlion representing; 
thta rcfU!tion, *rf p. 1*»H). Alcohol, BUgar, and vaiiou^ t>thcr 





1G8 



tup: metallic radicals. 



eubstances whit'h are moderately eawily oxidixed iinsvver a^ 
well lis hyrlrtjgt^ii sidplddu. Fur ii tnt'tlmd uf currying (nit 
tiie rev<^J"se *JiH'niL!uu tu UiaL just dt^srHUed, r, c, Uie cou ver- 
sion of a c'lirciroR* 8iilt into tt t'hruiiuitLs see the dry-way 
reaction tor chruinlum cornjKiunda in general on p. 170. 

Chromh* mijthale^ ^'rj(Si> )j, likf idmiiiriimn fsu!phate, A 1^(80^),, 
unities with alkali-Mietiil suqphajk-ti to Jbnn doulile va\\\a winch lire 
L'lilliil tthim/t. Thftw-i id tuns rL'>M.'jnl>lL* cunimuTi iilum iti irvsudHne 
t'orni; but ibey d(i not eouiaiii aluminimn, llie jdaee of ihv latter 
being taken by ckrouiiuiri: tluy are of a purple color. 



Ghromic Anhydride. 

Ei:periiiient, — .Mix four vulnniei* <d'a eold saturat-ed aqeeous 
solutiiju itf (M)taif^iuin ilicbroinate witb five of sul])burir aeid ; 
on ft K) ling, i' h m u i it* aith tfd rifie of te 1 1 i*a lied c h ro n t if aci d^ t. t( ) j, 
{Chi'mnii Trinj-ifiiitn, LL H. 1\ ), separates in erinisou uee<lk\s. 
After wt'H driULuri*^, the crystals may lie freed from adhering 
«uijdinric ueid by wasldni,' onee or In ire with nitric acid: the 
bitter may lie removed by pas^sing dried and Blightly warmed 
air throu;4:b a tube eontaiiiing the crystals. Chrondc anhy- 
dride may aldo be freed from sulphuric acid by one or two 
^crystallizations* lu contact with moistyrcT chromic anhy- 
dride take}^ n[i water and ibrmis a solution of anhydnR*hromic 
arid [H,,( V^OJ, Cbmmic anhydride 'i& a jwjwerfully corrosive 
oxidizing agent; it melt,s l>etween ;^5(i° ami 374° R (180** to 
UM)^ C)* aiid at a higher teni prat u re dePom|H>jH'.s yieldinn^ 
chromic oxide and oxygen; it oxidizes organic matter with 
great violence^ sjjontaueous ignition sometimes resulting. 

la the systematic analytical examinatinn of solutions eontjiin- 
iag rhromates, the chrominm i.s prct'iintated iik green chroadc 
liydrf(xi<le aloaj; with ferric and alununiuai hydroxides the prior 
treatment with hydr^igen sulphide in presence <d' hydnx^hloric 
acid reducing the chromate to the condition of a chromic salt* 
thus; — 

2K,Cr,0, + una -\- 6H^ = 4CrCl| + 4KC1 f 14H,0 x ^^ 

Chromium having ln^en found in a siibitioa, \t» condition as chnv 
mate may be iiseertjiined by noting the yellow or orange etilor «»f 
the solution; by obst^rving the precipitation of sidphnr^ as alwve, 
with sinmltanenus change in color from (iriuigc to green when the 
aciduhite*! solution is treated with excess of hydrogen sniphide; 
and by applying to the solution, j«dtH cif barium, mercury, lejul, 
and silver. (See the various panigmphs relating U\ those metids)* 





VHliOMiUM. 



I 
I 



I 



!(;[) 



BftfNO,), givc^ velNiw IkCrO^ ^villi < bromates. 

"IgNO. „ ml H^^.rH), 

AgNO, ,, ml A^',rr(), 

A^'^NOj ^^ rt^l A-f/VJi. with tlirhrcMuates* 

n»(U,H,Oj), \, yellnw rbUrt), witb bi^th. 

nariiiin rntmte dm^H not foi»i>leU'ly pret-ipitiite (lit^hromatea, 
Imriuni dichrtinittte Ixriiig soluble in water; barium ehroinate is 
ttisolubte iu water and in acetic siL'iiJ^ but »<ibiblt' in bydnjehloric 
or nitric aeicK Meriun»us nitrate dnvw imt wbolly pri'ei|iitate 
iHelirumutei^ i menurif nitrat<^ or ehbiritle only partial ly imt ipi- 
Uitei? chruniateH, and *l(>es mit preeipitnte tlichroinates. ilereuroiis 
chnmiaU* l** ijisoluble, or neiirly sii, in ilihite nitrie acid. Siht-r 
ehromate and dirbroinate are .soluble in aeids and alkalies. Liad 
acetate preeipitiitfs lead rbromale from bnfb cbromati^ nnd di- 
cbnanatt^, aeetie acid bcin^r j*t^t frtn* in tbe latter eat^e (K,rr,(>, \- 

A cbdiciite reaction for dry ehromittes de]>euds nn the 
fonnatiuil of ehromijl ehhride or chiomchromic anhydrUle^ 
CrOjCL* A 8niall pKrtion of the rhroniate is placed in a tie«t- 
tul>e with a fnij^fnient of dry stjdium ebloriile and a drop or 
two of sulpliiirie aeid, jiinl tbe mixlnre i:^ bealed; red irrita- 
ting' fumes of eblnroidiroiijie aubydride are evi>lved» aiicl eoQ- 
deiute iu <iark red dropj^ on tlie ^\i\v oi' tlie tube. 

Larger rjuatititiejs are obtained }»y the smne rcaition, tJie fipera- 
tirm l»eing eonducted in a rehirt, witli ttifprouj^bly dry materials, 
aM the ('omfMjund it* decomposcnl by water, f 'blurocbrcjiiiic aidiy- 
dride may be repinled an ebromie anhydride in wbicb an atom of 
oryjren ih di^^jdaeeil by an etjuivali-nT tjuantity (two atom,H) of 
c'hlnritie. It in not nwed in ojedieine^ but Ls of interest U» tbe 
f¥tndi*iit ji*4 an example of u elans »>f com|»oundw known an »iW- 
thloritif'«. The reaction is also tieciisionally Hervicealde for tbe 
cletc^etion of chloridei*. 

Anahfiical Readions of Chroimc Salk, 

1. To a solntion of a ehnmtie sjdt (ddoride, sulphnte or 
chrome alum) add amnniiHuni hyclrtjsijjfjbide ; a Imlky ^^reen 
liref^ipitiite <»f efinnnie hydroxide, Cr{OHj^, is [jrotlueed. 

2. To a solution of a ehromie salt, add amnion in water; 
^reeu ehroinie hydroxide ih preeipitated, insolnldc in exeej^s, 

3. To a Holntion of a ehromie salt, add >«dulioo of yodinni 
or |¥ita«8iuni liyilroxide ijrop by drop; frret'ii ebrionii' hy- 
droxide U pn^tpihUeil. Add exeeB^* of the alkali; tlu- |>re- 





170 



711 E METALLIC n.iDlCALS. 



eipkat** is dissalvetl. Boil the st>luti<in tW t^oiiie time; chro- 
mic hydroxide m reprecipitalwh 

Vhromw Oifjhtjdrftxith'x, — liiteruiediiitt' in t'<iiii|>fisition between 
L'linimie liydrtixidt', Cr(()H)3, iind thnmric ijxi<k\ t'r/*^, tw*i oxy- 
hiidroxidis jin- kiinwn, nuiinly, Ci, i J(nH)^ iiitd TrOnH, 

Dry- way Reactioa for dirommm Compoimds in general. ^ — 
Mix w small <|iuiiitity of any chnmiiitin romjM>uiid withHwliuni 
r.irhonsitt* and n few »rrainsi of nitre on phuiiunn iioh and fuj*e 
the mixture in the blow piiM*-fJame; u yellow mass ( jHJtassium 
and f^riiluiiix ehromate^) is formeiL L>i!<'<olve the nuiis^ in 
wjiter, aiJd a<u4ic acid to decomjKj.'ie exce^^s of earboiiale, antl 
ap|>ly tho reaj^^ent.s fnr rliroinates. This is a delicate aud use- 
ful reai'tion if cart fully perfonneiL 

The proiluctlnn of the L"hn>mat4? from a ehrnrnie ^It in the 
alxive reaeticm amy be repre^nentt^l by the ecfuation : — 

2CrC;i, 4- r»Na^COa t 3() = 2\a,Cr<), + GNaCl j :*CH3^. 



i 



DIRRCTIONS FOR ArrLYIXO THK ANALYTTf'AL HEArTfONS fJK- 
StmillEIUN THE FiHtEUOlXiJ F^A KAliUAI-H^ TO TIIF. AXALYSI8 
OF AN Alil'EOrS SOLrritlX OF SALTS TONTAINlXfi 4»NE OF 
THE METAUS, AUMINIFM, IRON, CHROMIUM,' 

First note the color of tl>e .^dntJon : — 

Bfdutions of aliiniinium siidtn are colorless^ 

iSolntions of ferrous ?4alts are colorless or pale^reen. 

Rolntious of ferric i^alta are yellow or hrownisb, 

Solutions of chromic salti^^ are bluish-purple or green. 
Add ammonia water (the p:roup renireot ) ^^radually :■ — 

A white precipitate, insoluble or nearly ^> in excess, indi- 
cate:^ an alnminium salt. 

A dirty-green pn?cipitatc indicates iron in the state of a 
ferrous salt. 

A reddish-brown precipitate indicate* iron in the state of a 
ferric ssalt, 

* The AtiftlyticAl behavior of rhroinium in the cliromir aaltii is nlouc ir- 
fernd to hfre. In the i*yHt#Mrii*tk ux:iniinAtioii uf iii»1iitifiri!% for other 
im ttillit! mdirAls WMdcH tlins<* !iithr^rt4i couskh/nsi. any rliroinalf itr 
clit'liriniiAti? orlffi^ftlly pn*sc'iit is t^oiiverte^l iatr> t'hnmii*' siilt before tht» 
Htji^d b n-Hchifid mt whii^h iihtniUiiuut. iron, a^nd chrtimiiitii sin* tintit^d fur* 
(\rtt»\ h«w<?ver, thjit «*iliitioiis of chruuktU^s aud dichromntL'Ji liiv ydhiw 
ft ml onift^t) nsspm^tivoly. 




Q I' A L ITA T! VL' A XA L YSIS. 



171 



A liluisih-^^rey i>rtH'ipituli^ iiisoluhle (jr nciirly su in excess, 
iinltc'utca t\ chrornit" siilu 

Tlie^f resjuhs may \w eoiifiruiL'd hy I lie a|i]jli("ali«ni of h) rue 
of the otlii*r tests to frefth jKtrtioiis of the sohiuon. 



Table OF SHORT UrilEUTlUNS FUR AI'I'LYINO THE ANALYTU'AL 
RE.VCTIONH Dr>;CRIBKI* IX THK FOUF^iOING PARACiHAPHH TQ 
THE ANALYHIt^ OF AN A<irKc>i:8 HOU'TIOX OF HALT8OF0XE, 
TWO, OR ALL THREE OF THE METAI>»^ ALUMINIUM, IRON, 

thrum; I L 

B«>il alwut one-third nfa test-tuheful of the solution with a 
few <lr*i])4< of nilnc arnl. This ensures tho oi hi version of ft'iTous 
iDto finTie wilt, Rinl eoahk^s lluMiext reii^ent (atoniooia) (*om- 
pi^lclif to precipitate tlu* iron. A<M a ylijj:ht execss? i\i* amnio- 
Ilia water aiM I .'sliakc the ntixtnn* : filter. Wash tlie precipi- 
tate»<lryiti an<] fun/ it !*n ]>latinmn I'ml witli sodinin carhnnate 
and |x>ta»Hium oitnUe. lioil the i'um^d nmm in water, mul lillen 



F«.0, 
hrowTi 



Fiitratt-, 

If vcHow, Cr is |>ri'^t'iit and 1ms f<>rnu*ti cliroiiiLite 
duniig^lhe tuHiori* l)i%'ide into twt» parts. 



1 
Add XH/.1 and 
warm. Whilo ppL in- 
dicsite^ A I. 



Add acHic acid iiioxtTss 
und AgNt >j,. livii p[>t. in- 
dicates Cr, 



AW/* L^lf iron is pN*seat, jiortionj* of the <vri;rimiJ wdntion 
njUj*t Vh' te?*tt_nl with potits-siyia ferri< yanide for ferron!^, and willi 
fttjtaHffiuiti fernxyaiiide f<*r ferric siilLs; dark-blue precipitate:^ imli- 
cttte ferrous* and ferric sjilt.^ respivtively. 

AWr 2. — If ferron>4 Miilt is a*d presentT the prclianmiry ehul- 
lilinri with iiilrk' arid is unncncs^ary. It is ^wrhaps thrrcftjn^ 
advinahle alwav:* to tletrrniine thi>i point pnvhtiinhj Uy Icstiai; a 
little of the ori^onal sfdutioa with ikita>wiurn ferricyaaidc ; if no 
Iduf prtH'ipitate is prrKluced, the nitric aeid treataieiit may he 
omitt4*d. 

('ERIUW : Ce. At. wt, 1311,2. — This element occurs in the 
iiunenil wtxie (whtih einitainH iron» cakiion, and the raremeUdn, 
eeriiini, huithiinnm, joid dirlyinimn fthc latter really a mixture of 
neodyiriium smd praH<Hidymitini] as sil^4*3lt^^H|; nls<i fM'caHMinjdiy 
091 iiiipurt* Huorlde, eiirbomiti% and phosphate. Theoitahit4% (Mi 



172 



THE METALLIC RADICALS, 



(hftlm^ IJ. S. F*, n while gnuiulitr iK»\\'(ler, in the only otHcUl 
salt ; it may he (ibtjiined iVoiii eeritv hy iMiiliug the powileix?d 
iiiiiKr^il ill I (Hirentnitid liydnK'hlurk" neirl for ^evenil hcmrs^ eva|>- 
onitiiij}^^ ill lilt iii«f aiul lilteriii^ in se|>urale nilicji; addbi^^ annuo* 
iiin wsikT til preetfHtJite hydroxith^s of all the metJilH except eal- 
riiini; lilteriiig, wasliiii^^ redis.sulviii^ in hydrtH'hk>rie acid, aiid 
jiildinir oxiilk- aeid to prt'cipitiite ceriuni *»xakite. The prepiim- 
tion Mill eonliiiiif* hiiithunuin and ditiyniiuiii oxulHtetf ; it is there- 
fiire Htrongly eulrined, tlie rcsultiug Innthiinuin and didymlum 
oxidcH diHiiolvtHi out t<i Hiine extent hy h<jiliii|2: with J* cnnecntrHted 
H<diitTc*ii of HininoTHurii ehloride, the residual cerium tixide dis- 
solved in builitija!: hydroehl*tric acid, and a mTiiortium oxalate added 
to jireeipitute eeriuni oxalate, i'e,,{C/)^)^. HFC,0. AiH-'onJing t<i 
Hiirtley, tlie i<reeipitiited hydroxides should be treated with 
4-hlorim% by which eerie hy^dr«>xide it* left insolnhle and the other 
hydroxides eonvert<Ml into soluble hyiK>eblorites. 

The oxiilatc in insolnhlc in water. It in decompo*?e<J at a dull* 
red heat, 47 percent^ of a yelkiw or, generally^ sahnon-colored 
mixture (jf oxiik^ reumining. IThuully the didyiniuni present gives 
the ifj;ruted residue a reikli^h or reddish -brown color. Theoxidis 
are solulde in boiling hydroehlorie m-id (witbout ell*erve»eenec^ in- 
dicating, intlireetly, nl)^ienee of eiirthly and other earbonate» or 
oxidates); and the solution given^ with exees-s of a natn rated aolu- 
tkin of poUywium Kulphute, a ery^ntalline preeipitiite of double 
cerium and |>otaH8iuin Mnlt>hate. Almninta mixed with cerium 
oxalate may be detected by killing with srilution of potassium 
hydroxide, filtering, and adding cxcj-sm of jwdution of ammomuni 
chloride, when a white fliX'Ciilent prtripitate (ahiniinium hydrox- 
ide) will be obtained The oxalic radical is recogtiixcd by neutral- 
izing the potassium bydroxidt^ stdutkm with flretic acid, and add- 
ing ealcium chloride; a whit^i* precipitate (calcium oxalate) fall* : 
this precipitate, tbrnigh insididdc in acetic acitl, Hhould be wholly 
soluble in hydrfHbloric acid. Aeid or neutral cerium woIntionK 
give with j^fxliuni iu*etate and hydrogen peroxide a browniMh-«Hi 
color (Hartley). 

QUESTIONS AND EXERCISES. 

Stut*^ the method of prepanitkin of l)<ltll^vsium tHehromate, — Give the 
rormula* of potHmiimi diromate and clirlironirttt^— Hf»w iflpoliwsitiiiichro* 
rotitv olitttiiUMi ?— Dt'SH'rihe the Hcliou nf hy<lri»Ki'» siilphifk* oii ttcuinlxttid 
fiolittiniis of rhromutc^^. — What b the formula uf chrome alum? — Mcution 
the cliicf tc?*ta f«r uhrtmiatcj^uTicI for chromic salt^. — What aru tbu fanimln 
and fimperticK of cciium oxulutc? 




1 

I 
I 



ARSENIC and ANTIMONY. 

Tbej*c» elemcnt^H, especially antimoiiy, resemble meUds in ap* 
pcarnnce ami in the chara^'tcr of hi^ime tit their eout pounds; but 
they are s^tttl ni(»re ek^y allied to the non-met^ds pli(i6phoru!» 



ARSEMC AXO ASTIMOXY. 



173 



an^l nitrtigca, with which tl*ey form Ji natural gnmiu The hydro- 
gen o»nnj>f>und8 of ihe four members td" thingruup are rt?{irL\st'iJteil 
by the rormula? NH5, PH,, AsH,, t^^hll;,. A few [m^pamtirmH *jf 
arsenic and antiiiiony are used in medicine; hut all are more ur 
lesa powerful poisoiiH^ and hence have toxjeolagical iuterest. 

From ohf^^'rvations of the vajtnr deiiNity of anw.^iiic, it wuuhl 
appear that the molecule rd'arseuk- contiuii.H lour atome, and that 
its formuJu. is Aa^. At temperature?* iibove 1700° 0. the vapor 
density encre«pondH to the formula As^. 

Front obj*erved analog' between the two element*!^ the uioleeu- 
lar constitution of antimony is probably similar to that of arsenic. 
Vapor density detenu inatioiLs, ninre<*ver, lead to the foruiulue 
A»fl^ aud HbjOft for arwenotis and antinioiious oxidt« (the formula 
Ai^O, has been adopted in the U. S. P.), 



AEBENIO: As. Atomic weight, 74.1 

OfTurrewf^ *;/r.— Arseiiiral ore:^ are fn^qucntly met with in 
nature, the commonest being iron a rs4^no-sulphide, FeAK»S, This 
'•ml^spicker' i?i roasted in a current of air, the oxygen of whieh, 
condiining: with the arsenic, form^ common tehltv HrHeiUc{* 'B.n^nk'* ' } 
or ank^nic trioxide, sornetiuieii called unhfjdroHn arnrimtut aeld^ or 
better, ar^enoun iiHh*jdrid*\ As^< )^, [Afiieui Tnoxidum^ V. S» P.), 
which is condensed in chambers or lon^ flues. It commonly 
|i|OCUTB aa a heavy, white, opaque powder, or in maAse^ wliith 
^'roually present a stratified ap pea re nee caused by the presence, in 
separate layer?*, <*f the crysttdline and npaijne and of the amor- 
phous and vitreou.i allotropic modihejitiouH. The vitrei tus i»r amor- 
pbouH oxide is far more soluble thiiri the cr^^stalline variety, and 
ibe two kinds exhibit other difrereurcw in properties, Such dif- 
ferences between the crvHtJillijie and amf>rphous varieties of an 
clement or compound or between two crystalline vanetles are not 
infrequent. Rffihjar (red algar) jh native red ar*iemc nnlphide, 
A»,Sj, and orpiment (nunpiifrnt^tifum, the |;old<*ii pij^mcjit), is 
native yolbiw sulphide, As,S.,. Arsenous iodide, Asl^, (Arneni 
fodifiumy V. S. P.), may be uuide fnnn its elrmcnt.s or by di^solv- 
ing white anw?nic in aijueous hyclrifKlie aci<l and evaporating the 
ito|uttc>n. It occurs in small oraii<re- colored crystals, or crystal- 
line m«j»)08, eKduble with [lartial decoiii|H»sition in wnter aiid in 
alcnhob Its ajpieous siduticoi ntfords the reactions characteriHtic 
of arwenic and of iodides, and is neutral to litmus. Heated in a 
test-tul>e, it almost entirely volatilizes, vi<»let vajiors of iodine 
b'?iiij{ *ct fr«e. Ebulliti<m w^ith mucli vvati^r gives rise to the 
foriiiatioa of a liastc salt. A snlution of 1 part by wci^dit of 
ars«*nous io4Ude and I part by weight of mercuric iodi<le in 1«)0 
fluid (lartfi rif wHt4?r, forms Liquor Ariseni d Hydnirgtjri Imtidi^ 
0. S. I*. {I>omfian*M S&hitifm). 



174 




TllK MKTAIJJV RADICALS. 



AlkaLme Solution of Arsenic 



Bxperiment 1.— Boil a grain or twM of |>tiwclt*red white 
ar8<^iiic_s As^Qj^, in a solution of ]m)Uussiuiij bicurhooate and filter 
it' nwt'Kstiry. The Holutioii, rolciretl \\\i\\ c*»!iifR>un<l tiiK'ture 
of laveritk'r, tin<l (.■untaiiiing 1 jwirt hy vvt-ijirl»t uf A^fi/)^ hi 100 
tliiiiJ |>art*i, tonus Luptor Polamii Ar.^i'nUi,i U, fc?. P, { Fowic/s 
Solution), 

Ar&enoiiB Acid and otiier Arsenites. 

White iirj*enic, i*r orxnmm UHiajdrhir^ -^^i***i (f^»nnorly mlled 
tirHeiioUK iicitl), wlicn diMs<jlved in wuUt yitdds a f^ohUioii nliicli 
o<nituin?i winie iir?ieiiuuH mid, H^AsClj, hydrogi^ii nr?iC"iiite, and 
jHij^sfi****-!! a faintly arid reat'tioii. 

AHj(\ -f iMlp = 4H,A8<3 
Arseuous ttuhydrldc Water Ar><tn»ous acid 

Wlii^n arst'iK^iis aiiliyilridr is dissi^lvi^I in j«jkitiniM (»f jiciUussiimi 
or f^rHliuiii liydroxide, tlif aiiliydiide l»eia^ uhoiI hi fxee»s^ thi* si»- 
talled acid arsenitos^, KH(A«njj and NalJ(As<)^)j, aru l(»niied. 
Ittiik'd for miww tiaio witli i xi'csrf of tljf resinHrllve alkali-iniUil 
wifbonatt'.'i, tin w silts yield otlu-r arKniit^H (really ojetaresenitt'ji, 
a*< the aeid wiltn also art') the eum|JOsitiun of wbieh \i> represented 
l*y the fornjuhe KA-'^Oj aTtd XaAMJ^, 

ArK'miuj^ anhydride fun-ed with alkali-nietitl carbonates yields 
f\vroan*4-'natL^ iNa^At*/)^ or K^A»jO,, as the case may be) and 
metallic arMi*iiie» 

Aeid Solution of Arsenic. 

E^^periment 2. — B*iil arseiiouj* nn hydride witb dilute bydn>- 
cbloric acid; the anhydriik' tilowly clit*>iolve.s. Such a iwdnlion 
niadf with ]>re.^Tibed projiortionH of aeid and water, and eon- 
taitiin^ 1 part by weight of As/I^ in 100 tin id jwirK forms 
Liqmfr Acidl An<^itw U. S. P. (De Vaian^iins Sohithn con- 
tains a grain and a bo If per oimee, ) 

AW*'. — ^The student ftbould alw IkjII arMniouH mibydride in 
water only, and tlniH liave an aeid, an alkaline, Jind an aqueoua 
urscnous solution f(ir analytical eompari«<.»n. 



Arsenic. 

Experiment 3. — Place a ^Tuin or le^s of arsenons auby- 
clri<le at tbe l*oH<un of a narrow test-lube, cover it witb balf 
an inch or m of Hiimll frairnients of dry <di{»rcoal, hihJ buhl 
ibe tnl»e, nearly borixontally, in a Buimeri flarue, tbe mouth 




of lilt* tultt? iMJjRg loosely coviTed Ijy the thumb. At first let 
the )H)ttom uf the tube projwt i^bghtly lieyotnl the fiaiiie, so 
thiit the ehurcoal nmy iKn'ome nearly red-hot; tlieii heiit the 
Injllom of the lube. The oxide will volatilize, beeimie deoxi- 
clize<J by the hot chareoiil, earbonie titdiydndf l>ehi|i" formed^ 
iind the element ai%^t'nit' { formerly soiuelime^s termeii ai-.-irni' 
cum), will t>e de[Hji3iteil iu the cooler (lart of the tube a?^ a dark 
luirror-like meLallie eoating. During the o|»eration a elmrac- 
teristie iwlor, resembliug garlic, is emitted. 

AfcffjJ/ir (tr)ttuir may be libtiiined in larpM]nan ti ties liy the above 
proeesw if the oi*eration be eondueted in venstd:^ td' approj^riate 
fiize, Perlormed on the HTnall scale with ^n^at eare, in narmw 
tulx*!*,arjd Using not trhareojil alone, btit hlmkJhtA- (a mixture ofidiar- 
rozd and poluHsima earbmmte (dibiined by heating atid jn^tasssiuin 
tJirtrate in a tt^st'tyln.- or nther elimed vi*>f^^l till no more fuaiea 
^ are evolved), tht^ reartitm han considerable amdytieal interest, the 
garlic odor ami the fonaatimi of the tnirmrdikr rinjjj brin^ highly 
characteriiftie f»f arsenie. t'oaipound?* of niercury arid aatinnmy, 
however, give suhlrnmtcs which rei^emble airseuie in appearance 
and must not lie adstakcn for it. 

Arsemic Acid and other Arsenates. 



Experiment 4* — Boil n grain or two of arsenoua anhydride 
with a few drojw of idtrie aeitl until re<l fumes are no longer 
evolved; evapmite the solution Uy rlryne«8 in a sniail dish, 
to remove exwjs?* of nitrie arnd ; rlis^dve the residue in water: 
the produtl la Arstnie Aei*l, H^At**)^. 

Arnenic ttcid, when strongly healed, loses the i-lciaentHof waler^ 
and arsenic auhydridep As^()^, remains. At a still higher tt-nipera- 
lurc arnenic anhydride diinaij)t>He!«, yielding arwaons anhyd rifle 
and oxygen, 

Ar»*i*iiic anhydride readily absorbs water and becomes amenic 
tteid, If,AsO^. Arwnne acid is reduced to arst nous acid by the 
I actjnii i>f Hulphurou^ acid. -ir.AsO^ \ H,,S( ),=^ll3AsOj I 1I^S(V 

SoIIa derived frum arst^nic acid are termed (tnmfitrs. The 

tlJ-Aiiiimmium arsenate^ (NHj).JI AsOj^may be made by neutrali- 

I «ng arnenic acid with armaonia. lis wdutituj in water i« m'casion- 

ally uhchI at a reagent iii analysis. Arnenie acid ia used in* an 

I uxidtxing agent in the manufacture i»f the welbknnvvn dye, 

I maiden til, 

^M>liiuttl arw'jiite and arsenate are naed in the cleansing opera- 
itiotui of the calieo'priater. 




THK MKTAfJJC nADICALS. 



Sodium AxBeoate and Fyroarsen^te. 




Hi) 



Expeiimeiit 5.^ — Fuse 2 or 3 grains of arseoous auhydritle, 
ASjC\, with sodium nitrate, NaKO^, and dried imdkirii rarl>ou- 
ate, Na^COj, in a |K)rcelaiii cTucible, and dis^solve the rwsnlt^ 
ing ni!p^ of sfHliuni pyroarsenale in water; rtolutiun of sodium 
arst^^nate, NajHAsO^ rewtdli*, 

AB,0,+4NaNO, + 2Na,€0, ^ 2Na,AB,0,+2N,0,+2CO, 

Araenonn Sijullura Bodium 9<k1Juiii NHrotiA Qtrbinuc 

Anhydride nitmtii carlHmate pyroftrefiiAte miUydrlde ftiihydride 



Na,Ae.,0, + 

Sodium [(yniar»<?nute 



H,0 

Water 



= 2Na,MAsO, 



Ory»talli/e<l from tlie ^olntion and drii^d, a salt is ubtaine^J which is 
represented by the formula Na^HAHO^, 7H,0. (tSfMfli Ar^efuu!^ 

The iiJihydmua wilt, Na^HAsO^, oht^iined by exposing io a tem- 
perature of 'Wl'^ F. {150** C), erystallized sudinm arsenate, is 
oflh'ia! {Sfxlii Ari^f'nm KtMirrah/jt^ IT. S. l\), A 1 pereent* 
at|ne<»nf? solution forms Litpfftr Sftdii Arnemith^ U. 8. P. It ha« 
about half the arninieal strength i»f Luptor Ptitastdi Artanti*^ 
IJ, S. P. Tlie anhydrous wiU is used beeause the (TystalliwHl salt 
m of Bt>inewhut uncrrt^iin cum position. The fre.sh crystals are 
represented by the forniuhi Na^HAst^, 12HjO ( = 53.7 percent, 
of water); theck' s(m>ij efllrtre^soe and yield a f*table salt having the 
fimnula Najl AsO^, 7H/> (^ 40.4 penx-at. of water). To avoid 
the possible employment of a mixture of these salti^. the auhydrouB 
salt, of uniform coraposition, is alone ofheial. 

The Htiidout will find tincfnl pnu^fice in verify inp, by cj^lrulat inn. the 
above nuiiibera repro»imtiiig the <ieutt^iiiial jiroportiwn of water in tlM 
two Hodiuni urHt^nat^*^. 

The cr\^stiilline form of each varietv of s^wliniii arm.*iiatc 
(NaJMsr*^, 12H,(>, and N:i,HAsO„ 711,6) is identical with that 
ttf thi' eorrespondinp: sodium phosphate (Na^HPO^, r2H,0, and 
Na^HPO^, 7H,0), the pairs of analojrous eoiaposition ln'iniJr itio- 
morphcms. This ir only orm instanee of i\w stronjr anah>gy of 
arsenic and ita eomprnmds with |dM>sphon>us jiml it^ eorresp<md- 
ing compounds. The preparations and charueters of the next 
Hubstanee, ferrtms arsenate, will reiniml the student of ferrouii 
phosphate. 

Ferrous Arsenate. Iron Arsenate. 

Experiment 6. — To a hot solution of sodium arsenate add 
a litit solulion of ferrous sul|diale m\\\ a amall quantity of a 
s<dution of s<Hlium bicarbonate; a precipitate of ferrous »n««iU- 
at«» Fej(AsO/)j, is produced. On a larger scale, 26} parts 




ARSENIC. 



177 



I 



of drie<i sMxIiurn arsenate dissolved in 100 of hot water, and 
201 of ferrous in 120 i>f \mi water, with 44 «jf Bodiuiii bicar- 
iKJuiite, may l>e enij>loyecl. The preelpUate sln>ultl be cob 
leet<*d on a calico filter, wanbefl, t^ijueezfib am! drie^l on a 
waler-bath, at a low tenvperatiire ( lOU" V„ 37,H*' C. ) to avoid 
exc'csaive oxitktion. It Is ferron?* arsenate, Fe^( AsO^ ) j, <JHj,0, 
with ferric arsenate and some iron <ixide. 

2Na,HAijO^ + 2NaHCU3 + aFe80 - 

Sodium Araetintc SihJIuoi birurinjiittte Ferrous siil(»hHU.' 

Fe,(A80.), ^- HNa,8(). 4- 2H,0 -( 2(.'0, 

Ferrous arsetmte ScmUuiii ^ulplmte Wutcr tttrbLiiiic anliydrlde 

The u?ie of the sodinai bii'urbonate is to ennuro the iibsL*nce r»f 
free Hulpharic arid imm the i^cjlutitm. This iu id dixHolveH ferrous 
ar&i^niite, iintl it is iiii]K»s.sihb,^ to prevent it^^ libenition if mily the 
ferrous sulfibate aad sfrtbum arsenate l>e einpbiyed without the 
^rRjiuui bieartwjnate. 

At the instant of prefipitatuni ferniUK arsenate is white, but it 
rapidly beeouies of a irreeu or ^reenish-bbie eohjr owing toabsurp- 
tii^ti of oxygeu iind funuatiou uf a ferrosoferrie an*euate. When 
dry» it iH a tuHteless, liinorptiouH pnwdtr whieh is wjlulde in acids 
:incl haH undtrrgoue oxirhition to a eousiderable ext^^it. 

Arnrme Htfdnfir and Snfpfiidtit, ami (hpfter m\i\ Silcrr Arnenifrs 
and Artmafes are uientioued in the following analytical pMragrapba. 

• Analyiieal Reuetiotm of ArMnic ComjM^nndK 

1. Re^ieat experiment 3, o|)erfttinf< on not very much more 
enoiis anhydride than the size of a small pin*s head, and 
ing not charcoal nlouet but the /.►/ar/:yf« a- already mentioned, 
or a well-made and perfectly dry mixture of charcoal and 




potaflsium carbonate (the latter salt l>e{<( olitahied by heating 
|iotiifiiiun) birarlxjnate). The tube enipb\ved s^bould be a 
narrow t4'Mt-luI>e, or l>etter» a tnlie (eanly nmile from ^daKs- 
lubiug) having the fbrm ( Her?'xdiu,s*s) shcnvn in Fig. "?H. 

The oxide and bhiek Hnx are placed in ihe bulb of the 
tu^^e, wliich i8 then heated in n Huiisi'n llanie; the nn^enic 
i?ondense«* on the <xm8tnete<l pjrtion of tlu' tuln^ If now the 
bulb Ih> carefully removed by tVisiug an*! drawing out the 
gins*, tlie ftreeoic may Im elmeed up and down the narrower 





178 



THE METALLIC RADICALS. 



part i»r tin* til 111' yrttil the air m the tube has re-oxidized it to 
arstmi>ii.s w n h y < I ri<ie< 

If the o|H:^ratioii hat< heen pertbrriit*d in a Jess delicutu man- 
uer in an iirdinarv test-tnhe, eut or break off p»rtious of ihe 
tulx* eoutainint^ tlie i^uliliniale of ar^^cnic, put them into a tesl- 
tulw and lieat the boUum of the 1 fitter, liokliu^^ it neiirly hori- 
zontally, and partially el^jt^ioj^^ ihe mouth of the tut^e wilb the 
tijitrer or thundi; the arsenic eondiiiie?^ with oxygen from the 
air in the tube, uiid the resyltiutr arseiioiis anhydride ts 
de|KisiiA*<l on the nwil jKirt t4 tfie tid>e in brilliant* generally 
im|>eriect, octahedral erystals. 

Fir,. 34a, 



Fm.lW 



O*i»iln<lron. 




A «wlVlftiiiit(> of arsennm atihy- 



Microscopic Examination. — Prove that the eryhtals are 
itlentieal in form with th<we of aivenuys anhydride, by beating 
a frrain wv k^4*8 of the latter in anoiber le>t-tiibe and examin- 
ing tlie two sidilimates hy means of Ji ^morl U'ns or a eom|Knmd 
mier<)R*ojie. 

Tbe ajip/aranee (if a ,'^nbliinate of arR'Uoiis anbydrnle is 
|Hruliar and (juite eharaeteristie. The primary form f»f each 
erystal u an ix^tahtnlron ( 'j^t^j, okh^ ei^bl; /V^ httha, siile) 
(Fi^. 34a) ^ or, rarely, n tetrahedron, an<l in a sublimate a 
few j)eriect oetahedm are ^^enerally prei^etit. Unually, how- 
ever, the erystafs are mo<litieations of (M-tabedra sueb as are 
shown in Fi^. 34 — whieh is <lrawn from aetnal Hublimate^, 

2. Reinflcll'8 Test. — Plnee a ]>itre of eopjK^r foil, alwut I 
iueb wide and \ ineh lon^s in a H<ilulion eoiHtiinin^' arseino 
ami bydrfK*bloric aeid, and (kiiI (nilrie mid must not be 
presents or the pieee of metal will be dissolved); ars«€»uic is 
iie|x>sited on the eop|)er as a gray eoatin*;^ |>0K^^i«ing a ^nie- 
what metallic appearance, ( Meviorandnnu — An e^juivaleot 
pp)jKirtion of copjier jproe« into ftolutii»n. The experiment 
forms an illusitration of a kind of chendeal eban^^e ap[vropriately 





I 

I 



ARSEaVW, 



t*?rmed suhditutiou. ) Pour oHT the +5upernata!jt liquid fmni ibe 
copper, wash the latter with water, dry it hy rueuiis nf a (liece 
at' filter-|m|M^r, mui tiaally j>lare it at thf iMittuui ut' a cleun, 
dry, rjarr<FW te^t-tuln:', or n Bt'rzeliiKs tube, and sul>liriit^ as 
dt*i4tTil>e<J in reiit-titm 1, afjfaiii nut icing tlie tor in of tlie rt.^nlt- 
in^^ crystaLH, Tht^ tulit^ cHintuitiini^ tht* sublimate nuiy be 
rej^trved for ?^nbsei|ueiit iM>m])arisuii witb a similarly oluainfd 
jiubliamte of antimotuoua oxide. This test for an*euic vvjis 
introduced by Reiiia^rh, in 1843, 

Nofr. — Copper it^^elf frequently ermtrtinH urnenii^ n (hvI llitit 
miiy notj perhiips, eiiiit*e iiny trontile Ui the j*tudent, w ti*i i^ ptr- 
forming oxperinuiitH in pructiral tbi jni^itry with known sultsbiiii es, 
for eitumtiomd pnrpoHt^n; but whrn iht- analvHt proceeds to tbci 
eXAmiautiou of sut^stain-e^ of unknown eoinpoMition, lie muj^t 
Hf$Mure hirnMeif that neitht^r hi^ aiipunitut* nor nuUeritilM already 
ecmtiiiri the eleaient for whieh he is searcvhia,i|[. 

Tkr *leteftmn of Hrnetiir in mrftf/iic rttjtprr in iH^Mt aecoUiidit*h<?d 
by txahn^f in a rptort or di8tilling-t1ai*k, n uiixture of a few gmina 
of the siimple with tive or six tijues its weight of ferric hy^lroxide 
or ehloride (free from iirH*'aie) and exft'ss nf hydroelilnridc aeid. 
The jirHenic i» tliUH volatilixed )ti the f'nruj of idvloride, juhI msiy 
he eondensed in wuter and deteeleil by means of hydroffeu t^u!- 
phide (iff^r reaetirm (J, p. 1H3) iir by ReinKi"h'« test. Tlic ferric 
ehloride jwdution m, if neee,Maary, iVeed tVorn any trace of arsi.'aic 
by ev{i]iorating once or twice to dryness witb exee^ of hydro- 
chloric acid. 




The hydrog»?u teat <br Aiveaic. 

3, The Hydrogen Test or Marshes Test. — Generate hydro^reo 

in the iiauai way by the interaetion nf zinc and dihite siil- 

[ tihuric acid, a bottle of alxntt fc>ur of six onuses capacity 

I l>ein^ w^\, and a fuiuiel-tuhe atid short deb very -tube piiswiiig 

through the tN>rk as shown iu Fig. 35. Dry the ei*eapiog 





180 



THE METALLIC RADICALS. 



liydrogeLi (except iu rough expeririietils, when this is scarcely 
iHH'ej^sary ) \\y afla]itHi^ to the delivery-tube u short |>ieee of 
wider tubiu"; filled with fragments of dried caleiuni ehhiride 
(a). To the other end of the dryiiig-tiihe tit a j>ieee of 
narrow tiihiug ten or twelve inehe.s h»nj^, made of hard glasa» 
aitd having it.s outlet end re<liieed to a ^nvM Itore by ilrawiug 
it on! in the Harne of the blowpipe. Wben the hydrogeu \n\^ 
been es<'aj>ing for a f^nfHrient nnmiK^r of minutea^ and at siieh 
a rate ii« to warrant the student in coaeluding that all the axr 
oritjlnalltj pnm'iti In the bottle ha^ been expelkdr kindle the jet, 
nnd then jwur eight or ten drojM of the aqueous arsM^nical 
Bointion, or tiiree or four dro|»i of ihe aeid or alkaline solution 
[irevi<»u?*ly [ireparnl, into the funnel-tuhe, wasinog the liquid 
into the generatiiigd>ot(le by meanH of a little water. By the 
aetiou of tiie zine ami sulphuric aeiil, the arsenoy^ ct)m|M>und 
i:* reduced to the state of arsenie, and the latter combines with 
Hjme of the hydrogen to form an*eniuretted hydrogen, or 
hydrogen arsenide, AaHj* 



Ar»c-ntiaa 
anhydride 



+ 12H 
Hydrogen 
(nii»eeittj 



Ab, + 



6H,0 

Water 



As. 



Anenlo 



12H 

HydroKcn 
(iiiis<:eiit) 



4A8H, 

Hydmcn 

iuis<«mae 



Hohl a pie<*e of glazed earthenware or porcelain (the lid 
of a |x*reelain erudlde (A) if at hand) in the burning hydro* 
gen jet ; a brown spit of arsenic is dt^pcmjted on the eold sur- 
face. Collect aeveral of the.^^ de|KJsiti^, and retain them for 
future comparii*on with antimony dejuiHiti^ similarly obtained, 
. T«J ensure the aaivereion of the whole of the an^enic into 
hydrogen ar»i>nide, it m advisable, toward the end of the 
o|*eration, to add a few drf»j>fiof solution of i*tannoui^ chloride 
in bydrochlorie aeid to the genera ting-tl ask ; this eauife? the 
preeipitiition of the ai'seuie in a Btate of very fine division, in 
which it 15 readily at^ted upon by the naseent hydrogen. 

The He[iaration of arnenie in the flaaie i^ dae to the deco«ip<i«d» 
tinti of the hydr(»p:ea arsenide by the heat. The mol («jreelain nt 
itnec condenses the arnenie, and thn;* pn^ vents xta oxidntion to 
anM?nou!* ardiydride (which would otherwise tiike place at the 
outer edge of the Hame), 

Hold a ?mall beaker (r\ or wide te?!t4ube» over the flame 
fur a few minute-s ; a white film of arseuouw anhydride^ As fi^ 



i 



4 




ARSENIC, 



181 



I 
I 






wiJl be clepoeited slowly, ami nmj be further examined in 
coiitnyit with the gimibirly pnKluced film f>f iiiitimumms oxide. 

During these experimeiitrt tlie clJtjct produtLd by tht- Imming 
of till' hydnigeti jiriwaiifle on tlu' cnh>r of the hydrogen tlaine 
slitiuld \>e noted ; the llame iU'iiuire?» ti I'luiractenrttie dull, Hvi^l, 
bluish tint. 

Apply the flame of a ga^-lamp to the mid<ne of the hard 
glBBs tlelj very-tube (rif, Fi^r. 35 ); tlie hydrogen iiriieiiide k 
deoonvtx'seil a^ Ik fore, but the liU-rated arsenie couden^ieH in 
the co<j1 part of the tui»e, lieyond the flame, as 11 dark metallic 
mirror. The tube may be removed au<i kept tor comparison 
with antijiiotiy deposit. 

Note 1. — ^The zine and sulphuric acid used for Bliir^h's test 
liiu«t be free from arf*cnic. Zinc, like ctipper, frftjuently contains 
ar9C*nie a.-* impurity. When a Hptrimen, free from arsenic, m met 
with, it should he reserved foraiiulytical experimenti*. t^nlphuric 
acid, free frtim ar«t^nic, can usual ly he purehimed, but samples 
ma»t always be te**ted as to their purity. 

Xofe 2. — In delicate and iin|»*rtjmt applications of Mjirsh*8 
test, magnesium may !)e t^ubstituted im zinc with safety, arK^nic 
not l>eiag found in inagneHiuni. Mjigncsium in nnh inconvenient 
for this purpo**e. Both ma^Tiesium and zinc, if jicrfeetly |*ure, 
interjict with acids extremely shiwly; l)Ut the aililition of n very 
small ipiantity of chlorophitinic acid, nt (jucc [>rninotej* uu ahun- 
dmil evolution of hydrojren. Platinum, however, has a tendency 
lu hold back arsenic. Acrordifj^ t*^ Dyer, rod /.inc lian a Hiiiiilar 

idency, while g^ranuhited yAm- at once pves hydrogen arH4'»iitle. 

AWf 3.— 8ulp(mric arid, which is often used for drying piscs^ 
deeom|M^«e8 hydrogen arsenide. (Calcium chloride is the appro- 
pHate dciiiecatinj^ agent for this pis. 

Safe 4. — The 1 >rigi a al a p p a ratns j i roj 1 osed 1 >y M a r><h , in 1 H ?lf i, 

111 a IT-ahaped tul>e, one liinli of which was short, and chased by 
_ ftopcock, m that the whole of a small (piaiitity of hydrogen 
snenide eould be collected, and at^terward cxatnined at leisure. 

Xo(f 5;— On account of the exceedingly }iois4iuous character of 
hydrogen arweuide, the preeeiling test and the next one sliould he 
ccmdueted in a welb ventilated Fume-euphoard. 

4. Heitmann's Test, — fJe aerate hydrofreti by heatiiijLr a 
©oue*M»trated BoUition of «*c)ditun or |>otas,sium hydmxide and 

ne pteeenof zine in ate!*Mube, to near the I>oiling p>int(Zn + 
2KaOH^H, + Na,ZnO,, »we p. Ul), Add a drop of arsenical 
eoliiiiDii, Now spread over the mouth of the tube a cap of 
filter-paper moistened w»«h iuie drofjof j»<dutioji of silver nitrate. 




3 



182 



THE METALLIC RADICALS, 



Again Wat the tube, taking care that tlu- lii|iH(l itself fihall 
not rtpurt op on to tlic vn\\. A plug of fottou wool may 
even be phieed in rlie moiiUi of iW tt^j^t-tnlw! to iirre^t this 
spurting. Tlie an*enjcul niiiipnuid is rechu'cni to ar^nk', 
which unite?* with the hydm^en, a^ hi Marsh's test ; and the 
hydrogen arsenide pasciiug up tlirongh the eap interucts with 
the silver nitrate, producing a purplish-hlaek ^^A (of silver). 

AsH, + aH^O + 6AgN0, = H,AsO, + 6HN0, t^ 6Ag. 

Nofe L — Thi>* refiction is vftlaahh\ «inee it ennhlet* the aRalyst 
quiekly to dLstiiigiii.sh arsenic in the pre>*iniee of antimony. iJaring 
the reductiun of an antitti*>ny coriipounil by nascent hydrogen 
in an acitl solntimi, a portiioi <»f the antinitHjy \^ converted into 
hydrogen aininionide, ShH^^, which also iict*s upon silver nitrate; 
whereas if the rcdnetion is earned out hi an alkaline solntitm, 
hydnigen antiinonide in not toniied, ami htiue the etteet juiit 
dr?ri<' rihetl in nr»t |>ro<ineed» 

Nfiff 2. — Alamiiiium an*^Avers as^ well an zinc ft»r Fleitinanii'« 
test (ft alehouse), or magncsmni may he used; or hi stead of zinc 
ami iilkali, !*odinai amalgam conLaining unly a wmull iK>qK»rtion 
(>fsf)dium may he employcfl (Davy). 

Note *i. — If the trlter-paper ea[> is mrastened with Bfdutitm nf 
mereurie ehlunde and thfii t^xjiosiHi to tin* aetinii of hydrogen 
ar?«Mi!ile, a yelUnv ?^tiun, A^HIl|r,ri2, results; heromiag after a 
time lirown, AsHgjCl^, .nnd then hlaek, An^Hg^. 

The formation of a yidlow atain when hydro|rcn art<enidf\ in 
small tjuantily, interacts with mercuric ihlorid*- (si^* Note '-t, alMive) 
has been made the liani^ of a rn<Kli(ication, elaborutely deHt/ribed in 
the tJ. S. I\, of (tut/eil'f* test for arsenic. The student i** ad vi^i^d 
to consult the pharmaeopo*ia for minute detjiils of the precautions 
neees!*ar>^ in eni]dr*ying the test in the examination of ehemieuls, 
generally, for traces of arsenic. 

6. Bettendorff's Test.^ — To a t«olntion of .stannoys chloride 
in eon cent rated liydroehloric aeid adfl n very ^mall f^uantity 
of any arseoienl !<olution. Arsenic then separates, especially 
ou the application of beat, |>rodncing a yellowish And then 
brownish c<dor, a grayi^h-Iirown turbidity^ or even a sediment 
of grayd>rown fifMi-ks, ae^M^rding to the f]na!itity jtresent. Much 
water iirevent-^ the reaction, and it^ iireHeuce nuist therefore 
be avoided as far as jM^ible: indeeil a litiukl saturated with 
hydnnddoric acicl gan given the liest results. Tfie presence of 
ar?it^nic in sii![diuric or hydrochloric acjch or in tJirlar emetic, 
etc., may be detected by means of this le8t. Nitrates, i»uch 
as bismuth oxynitrate, must first lie heateil with snlphnric acid 



4 





ARSENia 



183 



to remove the nitric uM niJit'ul bejiire applpng this te«t for 
anienii'. The stnnnotis wilt is converted into stiinnic siilt 
iluring the remliim. 

The tbregoiQg are the ruost iuijmrlaiU reaction;* of ars^enie, 
whether existing in tlie arseuous or arsenic conilition; of the 
following reactioniJi K> tiiid 11 may be enijjloyed to dis^titiguish 
aim'uous and tirsenir e<>in]XHind:i from envh other. 

6. Through an aridtilated ar^cnons jioliition |*u.^s liydrogen 
*iulijhide; a yellow precipitate of arserious Hulphide^ As^S^, is 
at once product-d. A"hl an alkali-inelal hyilroxiile or hytlro- 
jiLilphide to a jKirtion of the |>recipitate; it rea«hlly di^t^jlves. 
The precipitate consequently wxiuld not be jiriMinecd on pass- 
ing hydrogen sulphide through an alkaline arsenons solution. 

When arsi'ji<»U8 sulpliidc is dijs»f*lveil in a Hulution nf a hydr<»- 
sulphide, a soluble meta-thijirHt-ait^' (Otior, tlmon^ s^nlphurj i?^ 
prcnlueed. Thus wbcii jumiionia hydrosulphide is usi tl the i^Aw- 
tion contains meta-thiarHt'oitc — 

As^Sj + 2NH,HS = 2NH^A«Si + H,S 

^VTien a hydroxide h nmnl, a mixture of aietareenite and nieta- 
thiarsenite Jj^ f»btaiiicd— 

2A8^, + 4NftOH = NaAsOi -h SNaA*^, + 2H,0 

Tm another portion of [W arw^nou^ 8nl])hide precipitate, 
well drained, add ctincentrated hydrochlorif^ acid ; it Ih int*ob 
uble — unlike antinionouH sul|dnde. (Neither 8ul|diide is 8*>l- 
nble in dilute bydrochloric acid ). 

Noit 1, — A yellow sulphide w als*o produced in an add sMdntion 
of a cadmiuai Kalt by the action of hydro^^ea sulphide, lint this 
Mil[diide irt iuMoluble in alkaline liquids, nnder certain circum- 
statH'cM tin^ toil, yields a yellow Mul[>liide, hut tin ih (itherwifle 
eJisiily di><tinguislied. 

Stttf 2. — A truce of arsi-ncHH snl[dii(le Is Homitiincts met with in 
tho jiulphur distilli^l frnm arsenical ]>yritcf4. It may he detected 
by ilige?<ting the?*ul]>hur in anunonia water^ HlteriaiTr andevajMir- 
ating to dr>'nes8; :i yellow resirlue of nr^eniHH snl[>hide in oblnitied 
if that fiuhstance be present. 

7. Through an acidulat**d solution of arsenie acid, or any 
other arsenate, pass ji rapid current of hydrogen anljdiide; a 
yellow pre<npitate of ar?ienic j^ul[)hide, Ae^Hy is prodnced, hut 
precipitation takes place very slowly in cold sidution^, lirauner 
and Tornicek !*tate that by a slow eurrent the ars<t*iuc acid is 
gradually reiln<*ed to an^'nons acid, ami a yellow [uecipitate 
IS form*Hl which eonsiHts of arHenouij sulphide mixed vsith sul- 




184 



THE METALLIC RADICALS. 



phiir. The reaction is mure rapid if the solution l>e warmed 
The precijiitiite is itoliihle in tilkiili-motiil hyilroxides and 
h}'dro?^ul|)liide.s. When it is diHj^tdvfMl in a liydrosulphide 
the solution cotitaiiis a thiiirsenivte, while a hydroxide pnMluees 
a niixturc i>f anieiiate and thiiin?enute. 

8. T(j an acjueous solution of arseuous anhydride add two 
or three dro|>a of *jlution «d' cupric f^ylphate, and theu 
cautitjij^ly a<hl dilute anuiiunia water, drop by droji, until 
a green precipitate is obtained. The jiroduetion of I hi* 
prei^ipitate \h eharaeteristie. To a jMirtion of tlie mixture add 
an acic]; the precipitate diiJ*s4>lve.s. To another i^irtion adil 
ati alkali; the pre<'i[)itate dissolves. The soluhility of the 
preeipitate in lioth add atui alkali showi* the advantage of 
letting a sn!^|»eeted ai*senieal solution by means of litinuti^ 
pafier before applyin|jf this reaction, and if found to lie aeid, 
cautiously adding alkali, or if alkaline, adding acid, till 
neutrality is obtained ; or a special reagent — eopjier ammouio- 
sulphate — may be uued. {See note to reaction 11.) 

The precipitate conBiHta of cupric arsenite, CiiHAjsO,, or 
Schedt*& Grten. In the jmre stitte, or aiixtnl with cupric iicetato 
or, occa^jionally, with i-uprir carlK^aiite, it is used as ji pigment 
under diflerent numes, suLdi us Brunswiik Green and Hehwein- 
furtli Green, hy painters and others. 

9. Apply the test just dc,s4Til>ed to a indution of arsenic 
acid or other an*enate ; a s<>niewhut similarly colored pret^ipi- 
tate of cupric arsenate is iditaineii 

111 Ret)eat reaction 8, substituting silver nitrate for cupric 
sulphate : in this case a yt/Aor preeipitate of silver arsenite, 
Ag^AsOj, is prodneed, hIimi soluble in acids and alkalies. 

11. Apply the silver nitrate tef^t of the preceding reaction 
to a 8(jlution of arsenic acid <>r other arsenate; a brown 
prtM*ipitate of silver arseniite» Agj^AsO^, is formed. 

(hji/MT find Sfirer Ermjrnh for Ar^t'itir. — The biJ^t tVjur reactions 
may be j^>erforrnecl with JncreaMnJ delieacy and (*crtidaty of result 
if the copper and silver reagents Im+ previfiusly jtrepannl in ttie 
foHowinpf manner: — T* cu|>ne snljihatc (te>*t-s(»laticjn) add nmnio 
niH water until the blue [precipitate at first fonued is nearly, 
but not tjuite, rediswolvcd ; (iltx^r a ad use the Ii<|aid n» an iirwnie 
reagent, lal>clin^ it Cujrrie Ammonium Hnljihate Test-Sfihjti*»ii 
(U. B, K). Trt^at solution «»r t^ilver nitrati^ (id>out 1 part in 20) 
in the same way, and hdicl it Hilver Ammonium Nitrate Test- 
Solution {V, S, IM. The composition of thei*e two sal ta will be 
referred to subsequently. 





ARSENIC, 

Arsenotis and Arsenic Compounds, — While many reagents 
may l>e m^d f(>r thu detection «>f ursenii\ unly the Iwhavior 
with gilver nitrate will iriHiiediiitely and ill^liiK'tly indiaUe in 
which state the arsenic exista ; for the twt> sidphi<iei< and tlie 
two f?op|)er precipitates, rhon^^h differing' in lurn position, re.«enj- 
ble each other in appearance, whereim the two silver precii*itates 
differ in color as well a» in eoni|>oBitiori, 

8t)Iuble arsenates give precipitiiten of insol n hie arisen a tes on 
the mldition oi* solutions of salts of barium, ealeium, zinc, 
and other metals. 

Arsenic, when it exists as arsetiic acid or other arsenate^ 
dt>e8 not rapidly re4*pond to the te^t with hydrogen snlphide 
or nti-scent hydrogen^ Hence, if it si [jrcseiiee, a.s art^enate, m 
.'«u.'<|K>cted, the liquid under examination siioul<l he warmed 
with a little .sulphurous arid — or trealed with hydrochloric 
acid until slightly acid and then with solution of sodium thio- 
*4ulphftte — liefore the addition of hydroi^en sulphide. 

Antidote in Cases of Arsenical PoiaoEing. — The most 
effective antidote in thei*e cujr^s is recently preeij>itatcd nuiii<t 
ferric hy*lroxide, administertHl as stjon as p(>s*iihle. It ia 
perhaps best a<lministertHl iu the form of the mixture iibtained 
by adding magnesia (A/(iy/o*^ It (^xidum, l'. S. P. }, previously 
rublied up t4i a smocjth, thin mixture with cold water, to a tlilule 
solution of ferric sulphate (one juirt of Liquor Fern Termd- 
phatUt U. B. P,* to about three of water)* This arsetdc 
tiutidote ( Ferri HijffroxHlam cttm Mmfnf^ii Oxhio) is offieiah 
Emetics should alscj be t^iven, and the stonuich-pum|>, or a 
Cfjuiumn India-niblK^r tube, used as a siphon, be applied a« 
ijuickly as pissible. 

The above statementi* regarding the antidote for ank^nical jM.Hcdi- 
ing may lie Verifietl by mixing the vjirioux sulwtanees together, 
filtf-ring, and proving the uhst-oce of arMi^nic io the fiUriite by 
applying some of the fon^going Uj^U. 

Mwif of Ariion of the A ottdofr. —The action i if the magnesia i« 
to precipitiite ferric hy<lroxide, I'V((>H),— nitignesium sulphate, 
Mgt^O^, heing formefi, which is ut leont hurmk^ws, if imt Wuefi* isil, 
umhr the circumstances. The intenii'titoi iM'twccn ferric hyilrox- 
ide and an^eiiou* acid resulu in the formutiou of insoluble ferroug 
nate. (iSfct al«> p. 158,) 



186 




THE METALLIC RADICALS, 



qvmruiss and kxeucises. 

What is the forujula of ii tiic^lccuki uf jn>i*iiir?— In what form doe» 
arsenic occur iu iiuturD? ^ l^csciibc thi; chunirRTs <if white arstiuic, 
Nuuu- the iitticial pn^panitioiiH yf ars4Miit".--B.v whal iiiethixl may white 
arm.'tiic h-e iniciin'e<l to iiiuUiliic ar»tijiic?^Givc tht?! foi-niula* of arst^noiis 
ttud arwcrik iitiils litul iuihytlri(h\s,— Exfjlaiti/by tHjuatiou^, t]w rt^actious 
which iHciir iu coiivcrtiug white arsenic into (yrHliiim aim^iiale. — Why ii 
aiibyilroiis iiiHtciid tif cryiitaillized scKliiim arscoaly employed otHciully ?^ — 
Defsmribu tlio Biiuiipuhitioim uccessary to obtain white arsenic iu its char- 
acteristic crysUilUne (mm, — How la Iveiiiw*h'& test Jor arsenic ajipHed, and 
under what ci re umiitsiiices may ils iudicjitioiis be fallacious ?—fiive the 
drtaiis of Marshes tc>ft for ari*enic. and the ]ire<';iuitioii!> to be ol^jicrved. 
Exphun the reactions hydia^Rmij*,— What ih^cij liar value liasFbitiimnu's 
tfist forar»enic?—De^^nbe the conditionau rider which hydrogen liulphidc 
iKTomt^ a trustworthy tt-st for arsenic. — How may a trace of arseuous 
Rulphide bo detected in suljihiir? — llciw are saltn of coj>|»cr and idtver 
applied as rcagento for the detection of aracnit'?— How are arscnitc* 
distinjETtiisbed firom arHcuales? — Mention the he^it antidote in cuhc^ of 
arsenical poisoning; describe the process by which it may liomoitit quickly 
prt'pjiretl, and explain ila action. 



ANTIMONY: Sb (Stibium). Atomic weiKla, 119.3. 

Occurrence^ dc. — Autinioiiy oceiire in tuilore chiefly as iiiiti- 
monious siilidjiik', Hli.,S^, )thtjiitff\ Th<? cTudi* or hfitrl autimtmif 
ut' (duinnm-y is this native sulphide tret^ri from inipimties by 
fusion: it lia.-* nstrintcd, t'rystallini\ lustrous fnicture; 8ub»€\jiieutly 
]iowikre<J iirid, it' it eontjjius niiy s^duble suit of nrH*uii'; \\w latl<*r 
removed by tligostkui iti uiiMnouia wat*^^ it rorrns the gmyt'«b- 
blnek cn'Htiilline /)wr//iVf/ A/rtr^' fj^i//mw«//. The uietJil is (*bt4iiued 
Ironi tbe sulpbide by nnistiiig, the re,«ultinj^ r>xicle IjeiH^ re<lui'ed 
witli eburt'oiil and s^Kiium <:arbouute. Tbe resnltinjjj i^'oria is 
known lis crm'H^ of aufhttfmij or fjffUfjt of ttn/imoH^, Antimony is 
als(^ tdftaiued from tbe native sulphide hy beating it wilb inm, 
ferr<iUi4 sulphide being lljrmcd at tbe same tiun\ I^fttiillic anti- 
mony is an impottjuit eonstituent of ftjpf-meinf^ Britnnnin mrtai, 
and the ht^t varieties of pnrter. The old pttmln emHien^ or ever- 
lasting emetic cup**, were made of jintimony; wine kept in them 
fur a day or two wjis siiid to have aecjuired an emetic quality. 

Antimony ban ver>' close cheiniail analogies with an^enic. Like 
arsenic, it unites with imiine to form a tri-iodide (t^hl,). A 
Immiide "' " 



I 
I 



AntimomouH and Antimomc Clilorides. 

Erperiment 1. — Boil ulHUjt Imlf an o^nec of nntiraonioiis 
solphide with tour or five, titnes its wei^ld of hydroidiloric 
f\i'\i\ iu a dish phiced iu a fiinie-i*njdnmrd or in the oi)en-air; 
hydrojreu ssulplnde Ih evolved and s^dution of antimotiioas 
chloride, SbCl^, is obtained. 




I 



-h 6H01 = 2SbCla 
UydiMtHiluric Amimoiiiiiiis 
jifld chlorldt-* 



Hydroj^eii 
snlphicle 



Thiw i»«)lulioii, ck-anHl by Kuli?^idence, ii* what is enmniouly 
known iw buffrr of nfiiirntwt/. If jmrt' wulpiiitje has bet'n iist^l in 
it8 jirfparatiou, the ]i(|ui<l is neiii'ly cr>k»rle.<,s; but much of Ihal- 
met with in vcteririiiry phartiiiicy if* simply ti by-[*nM.kirt in tlie 
g-enfratioii r^f hydrogen Kiilphulc iVum native ferraginons anti- 
fiioniou^ sulphifle mid hydrmhleirk; aeid, and is more t)r less 
brown frcmi the pR'senee uf ferne ehl(indc» It not infref|Lie!itly 
darkens iti t-tdor oti keejiirig; this h due to abwirjition of oxygen 
from tlie air, and omversion of liglit-eoiored terrraia into ilark- 
brown ferrie cliloride <»r oxyehloride. It in i\ powerful eiiUBtif, 

True butter of aHtimnntj^ Sb(1^, '\^ (thtjuned on eva|M>rating 
the alM>ve iSidutirm to a sjnal! vohnue, trnd distilling the rei^idue. 
The butk*r eonrleases ikA a white erys till line semi-transpnrent masa 
in the neck of the rc'tort ; \\i the tdo?*e of the operation it may be 
melted ami allowiHl to How into a bottle, which sh<iuld be well 
stoppered. It is iiighly C(*rr«isive, 

Anfhnofi*/ pt'fi/*tr/ihtnfft' or antimfmic chloride^ Bh<lM^» i» a fuming 
lic[ijid, obtained by pa^^sing chlorine over the trichloride. 

AEtimonious Oxy chloride. 

Ezperimant 2. — Boil the stdutiun of autinionious chloritle 
prrxluetHl iu exj)erimfiil 1, and jKnir il into several ounces 
of Hater; a white precipitate of antimontouH oxychloride, 
Sb^O^CIj, is produced, Home niitimonious chloride remaining 
ill the superoataot acid liijuiiL 

Tin;* precipitate jh the saliHtiinee fonnerly known as puhin 
Aitffirfitfti^ f/idn* angeilmi^^ or mcrmriint vittr\ It varies somewhat 
tn ei>rnpo»^ition, accorfhng in the mnonnt of wjiter with which the 
chloride may he mixed ; Init, on standing uncJer water, gradual ly 
btH»om**s crj-^stalline, and Iulh the eoni|>iwition given jilw>ve. 



48UL\ + 


mp = 


- Bb.OPs ^ l^>H('l 


Jkniinitinloun 


Wfttcr 


Aiitlmoiilnup Jtydnwbluric 


chloHdo 




i».ty4'ljl*irldij iicld 



Antimonious Oxide. 

Experiment 3. — Wa^^h the preci[ntnle obtained in exfieri- 
ment 2, thorou|^iily with unier. by deeant^ilion {"ee ]k IHi), 
anci aihl solution f>f sodium earbonatt*; the oxychloride is 
decomf»oi*e<l, ami antimonifHis oxide, Sb J J^, is proihieed. The 
latter wof a light btitfor grayish-white color» or tiuite white if 
absolutely free from iron, inaolubk* in water-soluble in hydro- 



188 




THE M ETA LUC RADICALS. 



clilone aeid, fusihle at n low red beat. The mi>ist iintinionums 
t>xi<le may be well washed aud em[iloyed l(jrejLjX!riTneut 4, iirit 
may be dried on u water-balh. At tenipenitar«'8 al>ove 212° F* 
(100° C )» it al>3*c^rbs oxygen and otlitr antimony oxides are 
formed. The pre^sence of the latter may lie deterted on l>oil- 
mg the powder in »okition of aeid potassium tartrate, lu wliich 
antimonious oxide^ SIj^O^, it* S4dnbk% Inii anfimonlr anhifdridty 
Hl>/>^iUHi antimony tetroxide, H\\0^ oriSlj/). (8m\, J^h/)^), 
are insoluble. 



S1.,0,C1, + 


Na_CO, 


= Sb.O, + 2NaCl 

Antimoinoua Hodiiini 


+ 00, 


Antimouiouis 


Cifcrbotitc 


oxychloritle 


i^rl»otiute 


oxidti I'hlcirldu 


auhydddo 



7%e higher nttthtumy ortde^ Sli,^ O^^ t tinned aHtimoni** oxid*' or 
nnfiijdndt\ t"orro,**|Mmdin^ to ann^aic tinhyflridt\ is obtained by 
ilei'oiii posing the pentaeliK^ride with Wiitor, or by boiting laetallic 
antimony with nitrie ncid. The variety *thtaine<l troia theehhjnde 
diiren* in s{ituratin*jf power from that obtained tVoin the nietjil, and 
IH termed metantimnuic Jioid, 

Tartar Emetic. 

Erperimeiit 4,^— Mix the nioisit antinionious oxide obtained 
in ex|H'rinient H, with alwut an e^iual ijnantity of |K)tiis8iura 
bitartrate ( ti partes of the latter to T) of the dry oxide) and snfti* 
(»ient water lo (orm a pa^^te ; set aside t'or a day to faeilitate txym- 
piete eoinbination; boil the produrtwith water, and iilter; the 
resulting liquid eoutainf« antinomy and pitui^iura tartrate, 
tartarated autimonv, or tartar emelie( emetic, from ifkiw^ etfied^ 
I vomit) K8bOC,H/V 



I 



4KHC.H.0, + Sb.O, 

Aoid potas«lu:m AiiUraotiioiis 
Urtrnte oxUh* 



4K8bOC',H/\ 4^ 2H,0 

Tartar tint-tk' Wiil«r 



On evaf>oratio!i, the salt is oljtained iu eolorle8s transparent 
crystals. The^se et)ntain water of ery^tallimtitm, and are 
reimwuterl by the formula [K(SI>())(:^11/)J^ H,0 AiUi- 
JHonit ei PoUimii Tartms, \J* 8. P, 

Tarttir emetie in vrry roimnfmly ropretieuteil (as abovt*) m 
potiissinm Jintimonyl tartrate (i^M y= antirnnnyl). It neemd almnst 
('t*rUujj, hctwmer, tlint. it \^ really thi^ |MrtHssium salt of tartraiiti- 
moniouM aeid» HSbt^H/),, in whirh antinymy is present im a 
part of the arid rariieal. A solution ufthisaeid (whieh i» vvry 
unstable), also the harinin ami si'veral utlh-r s-dt^. havi« liepii 
obtained. 




ANTIMONY, 



1«9 



Tartair emetic i» wjluble in water, an<! Rlightly t^'> in fir^ per- 
cent. ak'ohr>L A iM>!uti<m in alrohol mid wtiite wine forms the 
official Viiium AniimoHti^ U, S, 1\ 



I 
I 



Sulphurated Antimoiiy and other Antimoiiy 
OxysulpMdes- 

Experiment 5. — Boil a few grains of aDtimonioua sulphide 
and iif sulphur with ftodiam hydroxide solution in a teist-tube, 
auil Jiiter (fir on a larger ar^ile, 10 ounces of autinionious snl* 
phidf, 10 of sul[)bur, and 5 of sodium hydroxide for 2 houri^, 
frequently stirring* and ocwisioually rejilai'iug watt^r lost \\y 
evaporation;. Into the filtrate, while still hot, 8tir rlilnte sul- 
phuric acid until the liquid \^ j^lightly acid to t€^*«t-pa[)er; an 
urange-red pre*npitiUe i^. |*n>dureiL It is a mixture of auti- 
luony pentasulphide, SI\^S., with nome oxide (Sh^O^, or |*os- 
mbly ^hjjO^) and mmt free sulpliur. The oxide re.Hulti^ fr«jm 
the interaction of autimouious sulphide and audium hydroxide 
in the prescuce of air* 

Thit* is one of the imuiy varieties <pf mintraf Irrmes^ so-called 
irotii their siinilnrity in eolfir to the t/tffcrf Irrmri^. AVrmf^ is the 
name, now obsolete, of the (^ram Hici-ff, n »ort of eoehineid-irrt^eet, 
full of reddinh juice, and uncd mivv the earlicM times for dyeing. 
The term mineral kerm*'A was appiireatly ttj» plied iiripnally to the 
ainorphoti.«< or preeifiitate<l orjmpe iiritimonious snljdde, Sli.^S,. ft 
afterward ineladid any iinxtiire of thin with tLxysulphide and 
pen ta»ulp hide. A hrowniKli-rod variety may be prepared without 
the iicldition of iiny free p>ul|dHir; the en! or (*f the preripitnle la 
then aifeete*! by thi* temperature as wed a'* by the sttite of dilutitjn 
of the alkaline li(|uid when the mid in added. When this 
alkjiJiae liquid is hoiled in eonUirt with air, oxy>^en h lihsorhed 
»iid tiniten with »i:>me of the antimony, dis^plaeinj; sulphur whieh, 
in turn, converts t*«jme antimony trisulphide into pentaMulphide. 
KrrmfM may he formtnl by fusion uh well a« by boiliuji^ the eoni- 
ponentM in aqueous s^dution. 

ETplamttUm f{/*/>rorr^fli<vt.— The liutrmony sulphides »nd oxides, 
like tb<»*e of arsenie internet with tin- ^ulphitles and hydroxide?^ of 
certain metals t^i form salts which are moreorh^ss soluble in vvalen 
Thus when antimonious suhdnde is diasolved in hr»t sidutiou of 
BfKlJum hydroxide^ sodium metantimonite, NaSbOj, and ineta* 
thiantimonitt', XaSlhSj, are tbrnvcd: in the presciiee f)f sid[»hur, 
widium metuntiinouate, NaSht\, and siidium thiaatimoriate are 
[irmhieedt the former of whieh is Hjjarinply sohdde. 

Antlinfitilmitf 
iUlphUt« 



4NaOH - Nji^SbO, 

8tMllum i^Oflluni 

li]rdroxide metantimoiiltc 



f aNaSh.S.^ A- 2H,0 
SmUani W»t«r 

muUi -tti J an tttnu u tto 



190 




THE MET A LUC RADICALS. 



48b^3 + 88 -f- ISNitOH 

Anltnioiiioutt SuJjihur Sodium 
HulpLilcjJe hydroxule 



= 3Na8bU, + 5>XHb8, 4- 9H,0 
Sodfum «<Miium Water 

mouinUmonAte Ihiantlmoiiutc 



The siilts w* IWnneii in hnt HolutirmH am not iill stuldo in rokl s*>iu- 
lKHi«, imd luitiiiKmy tixiiie:^, ttr sulpbidi'Sj (ir LkjIIi, are depowit^d 
wlu'n llie Imt stdiitifuis Vim\. Thun 8<Miiuin niehi-tliiiintinjonite 
tletompOHeB yielding sodiiun orth<i-tbiiintini<mite, Nuj^bt?,, ujid a 
deposit of antimoniuM sulphide, Hbj8j: 

3Nii8USj = Nji^SlkS^ -[ Sb,^S, 

Iti the jiropamtion of ktTnn\^ therofort^, lht> iicid sb<inM 1h> ad<led 
tn llie solution ^ilttniiu'd un boiling up tbe nn-^jJiSfiry iii^rtMbrMiU, 
befoR^ tiny prucipitiLte biw hiopamted (tbat iw, before ibi* wdutioii 
ie €Oo!), if unifonuity uf pnMluet m desired. 



BcHliyiu luiHa- Siilidiunc 
thlautimonlte add 

4NaSb03 -f 2H.8(>, = 



N! 



, 4 Bb^, 4 H^ 
lliuoniou " * 

4 Bb.O. 



um AnUiuonioUi nydrofren 
^ ' " Bulplilrte 



melantimoiiitc 
tUiutitlmytitiCe 



iicirj 



Bodlnm Buljihiiric 

iiieUDtimonAto acid 



finlphAte 

2NaH(), 
Swlbim 

SiMfUum 
jiulplmtt! 

Na,!SO. + Sb,0, + 
BcHlbnn Antlmonic 

sulplmte ox\6e 



AntltnimioitA 
oxide 

-! .SUA 

Aiitlmimic 
^ulplitdc 



2H,0 
Water 

f mfi 

Hydrt»gi*n 
BUl^ilitde 

Water 



Tbc fjxides and «ulpbide^ iiulient^Ml iti tbes(* equation*, are all 
priTipitiited wlwn tbe wriil m iiddcil, and lonii the vanetica of 
KermeM. 

AfHti^tical EeadiotiJs of Anftmomoun SalU. 

L Tbnmgh an aciilified antimouioag sohition ymsa hydro 
gen 8nl[)bi(le; an orange predpitate i)f amorjdiouj* antiniouioud 
sulpbide, Sb.S^, is proihieed. It bus tlie siime <'onij>ositiini aj* 
the erystalline black *sulphitle into which, irnb^tl, when dried* 
il Is quickly converted by heat. Like ai^ejious sulphide, it 
if? soluble in solutions of alkuli-nietal bydro.snlpbides and 
bvdroxideH. t'olle*!fc a |>ortinn on a filter and, when well 
dniineiL add concentrated hy<lroc*hloric acid; it dissolve 
unlike arsenonia sulphide. 

Aulinnmic snlfihide, Sb,S^» ctjrrespondini? tu an^nie sul- 
phide, As.S,, is known. It is formed on passing hydnvgen 
sulphide throngb an acidubitetl sobition of antinioniccbloridet 
SIjCIj^, or* le8s pure, on lioiling black antinioniouB sulphide 
aud sulphur with a ciiiLstic alkali* and decomfMit^ing the rei*ult- 
in^ filtered lifjuid by means of an acid. 




I 



ANTIMONY, 

2, Dilute tmj or three drops of a solution of antiraooious 
chluritle with water; ii white precipitate ol" antimonious oxy- 
chhjriile i* produced {^re experinieut 2, p* LH?), The prf> 
dtiction of a precipitate in these circumstances, distinguishes 
autiniooy froui iirst*uic, hut tlie reactiou i** uot eapabieof being 
ajiplied as a delieate discriniiuating te«t in iinJilyt<iH. Achl a 
eufficieut f|uantity of hydrochloric acid to tli^ssolve the precipi- 
tate, and boil a piece of t\ipj>er it* the t!o!uth*n, as direx^ted in 
the corresponding te^^t for arsenic (reaction 2, p. 178); anti- 
mony is deposited on the eop|»er. Wajih, dry, and beat the 
e«>p[icT in a t<«t'-tul>e ai? there dc?^enl>ed ; the antimony, like 
the araetdc w volatilized otftho copper and oxidized, ami the 
white oxide conden,<-*es on the nde of the tube ; hut the ^ubU* 
mate, from h^ low decree of volatility, condenscM close to the 
copper; moreover, it in generally non-cryi*talliiie, rarely in 
acicular or octahedral eryitals. 

Shake out the copper and boil water in the tube for several 
minutes. Do the sanje with the arsenical aublimate similarly 
obtained. The bitter slowly dissolves, and may be reai^uized 
ID the solution by meana of silver animouiuni nitrate ; the 
autimonial aublimate is ius<jluble. 

3. Perform the operations described under Marsh's test for 
ursenic (reaction 3, ]\ 178), plac'm<; the apparatus in a well- 
ventilated fume-<ujpbrjarfl anti carefully tib^t^rving all the de- 
tail there mentioned, but using a few tlrojis of solution of anli- 
monious chloride or of tartar emetic instead of the arsenical 
iw>hition. Antimony hydride, anti ruon in retted hydrogen, or 
hydrogen antiinonide, SliH^, is formed and may lie dei^omjx>sed 
in the f»ame way a?^ arsenic hydride. 

To one of the arsenical sp>t*^ on the |Kircelain iid (p. IHl ) 
add a drop of a dilnte solution of bleaching'|K)wder ; it quickly 
diasolvee. l)o the same with an antimony »[mt ; it is nnaftected. 
Hi*at more cpiickly cau^ei* the volatilizatit»n of an arst^nic than 
pf an antimony spot; amnion ium hydrmnlphide more readily 
dlMRidves the antimony than the arsenic. 

Fioil the water for several minute.^ in the beaker or wide 
tej*t-lube containing the arsi^nical sublimate (p. 181 ) ; it 
slowly di^olves^ and may be re^-o^ni/xid in the ndutitm by the 
yellow precipitate jriven cm the addition of solution of silver 
nmmcminm nitrate. The antiiuonial sublimate, similarly 
^eateil, does not dissolve. 

Pass a slow current of hydrogen sulphide through the deli- 
Tery-tuhe removed from the hydrogen apfiaratus (p. 181 ), and 
wbeo the air has been expelled from the tube, gently heat 



102 



THE METALLIC RADICALS, 



that portion coutaioiog the de^joeit of arsenit!; the latk^r will he 
€011 verted into a ijrllow Hiihlininte of arseoou.s sulphide. Re- 
move the lyl>e from the hy<lroj;:eii-8ulphide apparatus, and 
repeat the ex|)eriirferil witli un iiiitiniony dejjosit ; H U ch>u- 
v*Tted into an nrnntje antitiicmious .sulphide, whirh, moreover, 
owiiijy: to iirferior voliitility, ttHideriaes nearer to the tlaine than 
the a n^ no us t^iilphide does. 

IVss dry hyd^x^ldo^ieueid gas thrtjui^'h the tvvodeli very-tul>es. 
Tlii.'^ is aceonijdiHhed hy adapting lirst one tiihe and then the 
other, hy means of a cork, to a test-tulie containing a few lunijis 
of eonnnon salt, ujM>n whieh it little snlphurie aeid is pnire*! 
prior to the insert ion of the tHjrk. The antiinonious sulphide diw- 
solve.s and <listi.|»f>ears ; the arsenous sulphide is unatfeeted* 

Antidote in cases of Antimoni^l FoiBoniiig^. — The intro<iuo 
tion of poisonous «h»ses of untinuinial eom]x>undi5 into ihe 
stomaeh is* fortniuitelyf|niekly followed hy vomiting. If vomit- 
ing has not occurred, or apparently to an insufficient extent, 
tanni<* acid in Kuy form nuiy he adraiui.Htere<l ( infusion of t^o, 
nut-galls, cinehi»na, oak hark, or other ai^tringent solutions or 
tinctures ), an ius«ihiide antimony t4uniate lieing formed, and 
aliw.^r[ttiou of the |K»ison hejng therehy soniewinit retanieti. 
The Btomacli-pnmp *ir stouiaeh'siphnn must be applied as 
quickly as ptjssihle* 

Recently fjreci|utat€Mi moist ferric hydnjxide is also, accord- 
ing to T. and IL Smith, a c^Limplete pre<ipitant of antimony 
from its s<3lutions, the eheniieni action }x*ing probably^ they 
say, sinular to that which tnkts place between ferric hydrox- 
ide and nrsenons anhydride. It nuiy be given in the form of 
a mixture of ferric chloride with either sodium carbonate or 
other siduble carbonate or bicarlKxnate, or witti magnesia. 

These stateaientfl may be verified by mixing togolhcr the vari- 
(jub pubstanccn*, (iltering and testing the filtrate forantioiony in the 
usual nmimer. 



QUESTIONS AND EXEECISES. 

What is tliB crimpot^iiimi wnd fM>iirc« yf **Blffrh Antinumy** f — In wHiU 
ii!luy?i is mtvtallj*: antimony a nhnracU'ristic ingreinrnt 7— Whut is ihe 
qimiitivateiKH> of atititiioiiy as far as indicuU<fl by thr f*irmiilti' of th«' nfll- 
rinl ppi^f«ini!ii»ti!!4?— Show by an <.'qtJatiuii how **Buiti'r of Autimoiiy'* is 
prifi^i red, — Writ** o»it MjuriHoii* ur iliuirram<* cxprt'^ivf of the renctiotw 
ivliitih cK'iMir in roTivrrtiiiK atitininnuiiiH chl<>ri<U^ ititonxiik''^ — What »» Uic 
fonmilft of Tnrtrtr Kinetic? — Flxpliiin hy aid of iH|iiHtiimA the prr|janitioo 
(tf Ki)lphiimt4'(1 nritimony.— (»ire acompnmtivp «it*it«'tJient of th<? t^sta for 
ar^t'iiir iiuil aiiiiriiony.— How is antimony detcM^tiHl in the preaenoe of 
nmctifc? 



^ 




I 

■ 
■ 



TIX 



TIN : Sn. Atomic weit'^n 118.1. 



183 



*^ — ^The i:hief ore 
fKTUrring in veins under tlu^ namt' 



if tin iH Htannic oxifie, 8nO^, 
}( fiiifitoftef nr inalluvml ck'j*<>s- 
it»M!< nfrmm-tin. The f^ldest niiiiCM are thnwe of Cornwall. Much 
tin is now iniporteii ironi Australiju Tht" laetai h tihUmwi] by 
reducing the rtmi*UMi nud watched ore by iui'au*< nl' i-harcoiil i»r 
anthraeiU' ' vmil at a lii>rli teniiKTatiirt*, and is juirifii'd liy nlowly 
beating, when the ]>ure tin, fusing first, is run tiW", asiim*'\viuil loss 
fujiibli* aliuy of tin, with small f|uii!itities of nrsejjie, rop[>erj inui, 
or k'lul remaining. The latter is known as h/ork fhi ; ihr iVtrrner 
hi'att^d until brittle amJ tliL-ii hannuered or let tidi from a heiglit 
splits int4> [>ri»niaHe fragments resign bliiig thtw^e uf stareb or of 
columnar 1ia.H]iIt, and is naujed flrtfpptif or ifrah fin. (jimkI tin on 
being liont eniitKa rraekling noine^ whieh is tt^rmed the '*cry^* of 
the tin, imd i^ caused by the friction of it« crystalline particies on 
each other. 

UMi^,^—T'm ij? an important constituent of such alloys a,s pewter, 
Britiinnja metal, wilder, sj>eenlum-nH'tal, l>ell-met?d, gnn-metal 
iuid bronze. It is very ductile, and may \w rolled into {>late«, or 
into leaveti known as tin-foil^ varj-ing tVoni ^j^;^^ to y^rtfT ^^^ ^"^^^ u\ii\\ 
m thieknc>*s*. Common tin foil, however, visually contains a large 
proportion of lead. The reflecting surface of hokimj-fjldaM'^^ vviw 
formerly always an amalgam <d' tin an<l mercury, jiroductHl hy 
carefully sliding a plate of ghins over a sheet of tin foil on which 
me^ri'ury had heon nihbed, and then excess of mercury hacJ been 
poured — hut pure silver, deiKJsited from a snlutinn, is now largely 
employed* /VVi* are made of bnu*s or inm wir»^ on which tin is 
dejKwsiited. Tiu-pfaif, of which common utensiln are made, ih iron 
alloyeti with tin hy dijiping acid-cleansed sheet-iron which ha*s 
W'vji immersed in melted tallow, iiiln vessels containing melted 
tin, and suhsequently heating it h\ a hath of melted tallow, which, 
by preventing oxidation, enabloj^ the tin more conijdetely to alloy 
with the ir<^m. Tut tnH^a are in reality tinned iron tucks. Tin 
may be granulattMl hy melting it and triturating it briskly in a hot 
morUir; or hy j^haking nn Itcil tin in a box, on the inner sides of 
which chalk has been rnhhed. It umy also he obtained in thin 
l>ell**<hHpe<ioreorrngated lVagmcntH(Tin. II, 8. P. ), by melting it in 
a larlle, and, as fioon as it is fluid, iionring it from the height of a 
few feet into wat«/r. Powdered tin has been uwd medicinally as 
a mechanical irritiint to promote expulsion of worms. 

Tin forms two set*i of efimpoundn which are called st;innon8 
and stannic, respectively, Thev correspond to the two oxides*^ 
8n() and 8nO,. 

Anihr^icile (from ir9(*ni, nuthrtfj, n iMiniiaju: <""tf^l K or vinne ami, difTers 

ihf* ordinary hitumitwu}i or tnkimf nutl in roiitaJniag Ii-sm volmtile 

ilt^r, and theirf<»re, in lairiOi»K without rtauie. It gives a liigher 

f^^mppnittirir, nnd from its tkoi mkinf^ prf*ni'rtieai.i», in famace opcrationn, 

t iniifijigeahtc than bitiiaiiaoUHcuab 





ISM 



THE METALLIC RADICALS, 



StaEQOUs Chloride 



Expenment 1, — Wurm si fragnieiit of tin witli hytlnx'liloric 
iK'id; Iryclrogeii ej^c*ii[it-8 and a jial^jtion i>i" fitiintious chloride, 
SnCij, U Ibnueil. It may lie retiiiiietl for future exptiriments. 

Till' solution obljiined by (lissolviniir tin in bnt mncentriik^J 
hydrot'liloric tit i«l (siuiu- u»irlis.H(i|vt'«l tin k'injr kept in the H*]uul) 
and iJissiilving the s^tuniKJUs t'hiorkle LTVHtalf* so obtiiininl in 10 
parts r>f watiT, conslituteH the ''Stunrions Chloride TeKt-Solut ion," 

Solid Statmotii^ i'hhMe, — By the evji}M>mtioii of the alKive 
Kf^lution, stanntjus rliloride is nhtarnable in en-stal^ 8nCl,, 211^0. 
It is a |ir>werJid reihieing agent, I'Vi n a dilute wtluti<tii iirfiiiiiU- 
ting pild, silver aial niermry frtan their sfdutiunH, innverting ferric 
and eujirie into ierrnus and ruproiiw siiks, iind piirlially de<»xidi- 
zing j»r.Hcnic, aian^anie, ami ihrfunie aeids. It absurbs oxygen 
from the air and i« dicfirnpoxiMl win n adiled to a large (|nantity gf 
water nnlens smnv acid \ui prescjit. It is used a.s a niordant in 
ilyeing luid eaUei>|irinting» 



Staniiic Chloride. 

Experiment 2. — Pil^ chlorine through a |K»rtion of the 
84^1 u htm of the slnnnoUi* chloride of the preceding experiment ; 
a sidution of slaimie rldnride, SuCl^, is fornn^l. Or m\*\ 
hydrochlorie acid to the .stnniRUhH solution, lioih und, in h 
fume-eupboard, ^^lowly drop m nitric aiid until no more fumes 
are evolved; attain stnnnic chloride results. Reserve the 
scdiitions for i<ybse*]uent experiments. 



Stannic Oxide, or Anhydride, and Stannates. 



Experiment 3. — Boil a frn^nuciit of tin with nitric a^ 
evti|H irate to dryness, mid stroui:ly ijjrdte the re>ijdue; liglil 
biitftHitcd stannic aidiydride, SnO^. is produce<i. Heal the 
stannic iirdiydride with excels of *itdi<l jHitn^sium or jtoiiiuni 
hydrf»xide ; staimatc of the alkali-nu^tal (K,.Sn0^or Nn^SnOj) 
resulb^. r>is?*olve the .staivmUe in wiitcr, ami add bydn:Mdi!orie 
acid; white irelatinoits dnnnh aeid^ Il.,*Sn(.)^, is precipitated. 

Htauuic acid is also obtained on ad<Hng a solution of a 
caustic alkali to solution of stannic chloride; it is soluble in 
excess of arid or tif <7iustie alkali. The pre<*ipit!ite in this 
ease apj>enrs to cmrre.^pond to the forniula Ji^SuO^ 
eauily lones water and becomes H^HuU,. 








SnCl, -h 4K0H :^ H^SdO^ + 4KC1 

The prrxJut't of the action of nitric avid on tin is also iin iwid, 
I but it iKdifitTent i'Tuni ordiiuiry t^tannii- iiv'ui \n:i^mmh m it th con* 
f-%'er1t*d by hyilnxhloric atiil iatt» im-tiLstjmnic i'hloride^ wliirh is 
in>*>lul»lc' in inodenitWy toiR't-ntniti'd hyll^l»Lhlc^^ie acid although 
^((luhle in water. It in ealk'fl mrtti.'^ttfHttU nridj ajid its niolecults 

I probably has the cinnj>oHiti<in iL^xj*rt\HtM^il liy tht* fcirimihi ll^'^Ugt*^. 
If dried over j*ulphnri€ acid, or at HHP V., it hicfMjio* n\^*^n^O,(^ 
(codium wdt, n^Na^n^O,,^)* This latter !suhstanfe is aisti |»ru- 
duoed l»y gently heating the acid res^ultiiig frtini the iuleraction 
of putu^Kiiiin hydroxide atid stiiiiuic chloride. 



5H.SnO, 



H,„Sn,0,,^r>H,0 



I 



IJ<ith iicid!« yield buf!-c(>lf*red siannit' oxide or anhydride, HnO,^, 
when Mtrongly heated. The latter i^ oiaploycvl m polisbing |date 
under the name of jtnltij ptftnirr, S^tdium gktn nair, Xa ^iSn* J^^ «^H^< ), 
i*s UMed an a aiordant hy dyer« and ealico- printers under the n:nive 
of (in jjrrjtftff'^fitjtitir, 

Ainriifjfiritl IirartiottJi of Tin Compounds 

Stannous or Stannic Salts. — Hejit any H>lid €omiM)iirid of 
tin with a ndxture id' ]H*ta8sinni «*yanide ami WHliiini carhonute 
on ebarcottl in ibc inner 1\nme of the hhmpipe. Hard ^Mol>- 
tllt^ of tin wparnte whieb^ wfien rut by n knife, exhibit a 
characterisUc bright white surface. 



Retittiotm of Siannons Sfilts, 

1. Throiipb a dilute sidntiim of a stannous salt r^taiinoiis 
chloride, for example ) pass hydro|ren sulphide; a brown pre- 
cipitate of stannous sulpfiide, SnS, results. Pour oH' the 
iUfiernatatit rupiitl. mid anmionia water to the moist preeipi* 
lite ( to neutrali/-e arid), and then aniiuoniuni hytlrosulphide 
lidutjou; tfie preeipilate is at least partially diswdved. The 
uddition of i^inie sul|)bur and ttie apjilieation of heat nniy be 
Beoewary to etfeet coui|dete s<dutiou. 

AquefiUK wdution of amraoniuai hydroHulphide becr»nie,s yellow 

rhrn ji day or twri old, ami then contains exrcK** of sulphur, some 

pf that element having liccdUfc ilinpluced by oxygen alisorhed from 

the iiir. Af* a Lons<'<|tH'nce of this (or hy the aid nf tlie added snl- 

'phur), the stannous sul]dHde, SnS, take*^ nji ?^ul|duir anrl dis*Mdves 

to fomi amiiKaildin t!iiow(;mate. From this stdution vellow stan- 





i 



THE METALLIC EADICALS. 

Ilk- wulphide (tiiiUHHy niixi'd with s^ulpliur) ih precipitated by the| 
uikJitiori iif €XtTHs of an aiiiL 

(NHJ^SnS, + 2HCI - 2NH,C1 + H^S 4 Sn8, 

2. To i\ soliitifHi of a stauQoii8 wilt ad*! ^vlutiou cjf pota^iiitn 
or&iMliiirn bydroxkle; a white pn*tipitate of staiintms hydrox- 
iile» Sn(OH)^, m produced. AdrJ exre^ss of the alkali; ihe 
|»reripitati^ dissolves. Boil the »(*lution ; s*jme of the lia iil 
rej)ivt'i[ntated as hhickish Htaiinoviif? oxide, SnO. Auiniooi&l 
vvaU'r gives a siinihir white predpitJite, ineohible in excels. f 
The alkali-metal carliouates do the tmme, t^arlwnic aohyclride 
escapiug. i 

Reactioju of Stannic Salts, ^K 

1. Through a solution of a Manuic salt (stannic chloride, 
for example) pass hydroj^^en sulphide; a jellow preejpitate of 
fitanriif i^ulphi(k% SdH^, results. Pour off the supernatant 
li«[uid. anrl to the juoist preeipitate add ammonia water (to J 
ueutralixe mid), and then anunonium hytlrosulphide ; the pre^l 
ci pi late dissolves. 

7Vb^\ — In thin reaetion the presence of much hydroehloric ncidi 
must he avoided, and the furmatinn of the preeipitale is farilitntedj 
if the sfdutifm W wanni'd. Htiioaie sulphuk\ like the arsenic and ' 
antimony snlphide>s, diKs*dve8 in jM^lutionsnf alkali-mctiil tsulphides 
or liydrnsulplddet*, with fonnntion of ck'tinite cry s tall izable ihto^j 
gfonmjft'jf (Mji^nSjj), 

AnhijdroHH xtaume m/phide, prepared by sublimation, ha« 
yellow or orange lastnais appeiiranee, and in know as momt gatd*] 
It was formerly used by dee<*rtitors as bmnziiig-powdcr^ but thaj 
latter umw Ui<uidly cfujsists of jjowdered bromt^'leaf, 

2. To a stdution of a stannic salt iidd |>otassium or sot^iuD 
hydroxide; a white prei*ipitiite of stauuie acid, HjSuO,, 
produced. Add excess of the alkali ; the precipitjiriou dis 
mdves. lioil the mixture; uo reprecipitatc otvunt — a reiio 
tiou by nie4in8 of which stannic may Iw? distinguisbe*^ fronil 
stanuoiis sidtit. 

Ammonia water pives a similar preeijjitate slowly soluble td 
excess. Potassiiun and s(»diuni earlHiiiates do the same, carbonic 
anhydride encaping; after a time the j^tannic siiH in again deprj««ited^l 
probably as jKjtassiuni or sodium j^tanmdj^, Ammonium carHonaU 
and all the bicarlionates give a precipitate of st^innic acid, in^sl* 
ublc in excess. 



t 

1 

1^ 



GOLD. 



197 



I 




Separation of Anlimontj and Tin, — 1\^ a piece of iron wire lie 
placed in the acid (Ht'l) N^luti^m nfthe twi> metjils, n bluck pre* 
cipitate nf antimony is tbrmed, utul the tin is rediicet] Ui the stun- 
noua eonditjun; tbe latter miiy be detecU-d by llie addition nf mer- 
curic i'hloride wihitiou, when a whito |irecipitatt? of inercuroua 
chloride in produced. 

2HgCl, 4- BnCl, = HiiOI, + 2Hgt1 

AHfidoteg. — In cases of poisoning by tin jwdt^ (f.*/., dyers* tin- 
li()Uor}f solution t)f ammonium t"aVb*jniite whimkl bi* given; and 
white of e^g m alno said to form an iiij4(iluhle precipitate. Vom- 
iting i^hould be indueeil, and the stomach-pump, or atomaeli- 
aiphon, applied. 

GOLD: An. Atounc weight, 195.7. 

Oeetirreneff ete, — Ciold oeiwrK in the tree «tate in nature^ oeiui- 
Jly in nodules or tkmjtjHit^ but in alluvial dt 'posits coin too nly 

H finer ntate of division termed gold dti.tt, VutUi is separated 
from aaudf cru.^hed tjiiartz, or other earthy matter with whieli it 
may be a^ii^K-iated, by agitiitioti with water, when the gold, frc>m 
its relatively greater specific gravity, falls to the bottom of the 
vcasel firet, the greater part of the ligtiter mineral matter being 
carried away by the water, Frrmi the ritdi sediiaent the gold ia 
dij«M»lved out by mercury; the aaialgani is liltereil and afterward 
difftilled, when the mercury vofatili/,t*s and g(^ld remains. The 
amalgamation may be facilitateii by tlie use of 8i>diiini, as 
dcHcribed under silver, Fnjm even the poorest ores gold may be 
ditirtidved bv sfdution of potiirwinm cvanide in presence of air. 
(See Faradav on gold leaf, 1857.) HKCn -h 4Au I 0,4 2H/_> = 
4KAii((:N) f 4K0H. 

Purr ffoffl 18 Uxi soft for use in the fr^rm of coins for general cir- 
culation, Gofd eaitt in usaally iin alloy of co{fper and gold» that 
of the rnit^ni {States. France, and (tcrmany contains al>out 10 per- 
cent. ofci>pper; the gold coinage of (rrciit liritain t-on tains 1 part 
i»f copper to n of gob 1. Austral inn gold coins contain silser in- 
#sl**ud of copj>er as alloy, ,AHv//rr^\r/r>^/ varies in (juality, every 
24 part« cont^iining IM, 15, 12, or t* parts of gold, these idloya 
being technically termed IH, 15, 12, or i> rttnrf Jifit\ the reckoning 
Wing in the old **pariH pier 24/* instead of the mon^ usual partH 

ticrcent. Articles made <d' the better tjualitii'S are usually Kt4Uo(HMl 
»y authority. Trinkets of interior intrinsic worth are often thinly 
caiite<t with pure gold by electro-depnsition or t>therwise. The so- 
myitterij (ftjd is an alloy of about 1 part of j>latinum und 2 
copper with a little silver. It resists the action of coiieen- 
t^Xsf^X nitric acid. The action of aqua regia and then ammonia 
reveaU the presence of copfM.^r in it, frfdd ftn/U nearly ]Oirc gold i 1 } 
to 4 percent, of silver or copper, according to the lighter or darker 




198 



THE METALLIC RADICALS, 



tint required) paasetl l>etwceii rolk^rs till it i^ ftbrmt ,^ of an inch 
iti UikknesH iinil then ImiiiUKTfd betwi^iMi shtvli* ofmiimal mem* 
l>nmc% termed gijlcj-bejilem* skin, arnj cnU-j^kin vellum till it is 
reduced t*» jraVirr* ^'t* aniAujo 'd^^" ^"^di in thieknetss. It lu^iy even 
Imniiuered till 280,000 leaves would be reijuired t<j form a pile nil 
irieh tbiek, 

EsperimeEt. — Pbee a irjigrneut i>f gold (>,<;, gold leiifi i» 
ten to twenty droj)*^ of aquii regia (ft mixture of three |)arti« 
of nitrie aod four or five of iiydriHidiluric aoi<J^)^ nnd set aiside 
in a wunn [daee (in a i'lune-euphoard j; ti solutioti of eldor- 
aiirie aeid^ HAuCl^, (fbrnierly regarded as a stdution of gold 
trieldoride or jiurie chloride, AuCl^h resiuhs. Eva|K>nite to 
dryuej^i*, fii^e, moij^ten with water, jwoir off the clejir lititiid, 
and i*etain it for ^ubHeijuent expe^inlent^. Bueh a ndutiou is 
official (Gohl tidoride Te>>t Solution, U, 8* P,j. Chlortturic 
aeid is very deli(jueseent. Sodium ehloraurate, NaAuC'l^itia 
readily eryritsilHzahle salt, A mixture id\^<jual ]iarts of anhy- 
drnUf*gold chloride ami anhydrous s^Hlium chhiride is official 
(^Anri ei Sod i i ( 7i fo nd a m ) . 

ThiH reaction is of analytical intere,«l; for in examining a sul»- 
stance sus^pected tr» he or to contain metallic gold» ^M>lutions wmild 
have to l>e etfected in the aho\e \\h\' befon?* reagents couhl he 
applieil, ai* gold is insohihle ia hydrochloric, nitric, or any other 
single aeid. 

Anahfficid BeadlonH of Gold, 

1, Through a few drops of .sdntion rif a ehloraurate or of 
an auric Halt ( theehloridc, AuCl.^, is the only eonveuieiit aurie 
salt) pitse hydrogen sul[jhide lu the cohl ; a Idaek prwipitate 
of aiirous-fturic snlpliide; Ati^S.,, in producHJ, This pre<:i|dtale 
<h\^dveH, with ilifiiculty, in yellow ammonium sulpidde. If 
the hydrogen J^ulphide Ive pasf^ed through a boiling goliition»a 
brown i>ri»<dpitate of metallic gold is produced, 

2. A stdntion of a ehloraurate or<d' a gold ««alt athi a ferrou.n 
salt, and i^et aside; metallic gold ispre<*ipilatcd in tfie form of 
a yellowish or reddish-brown lustrom* |)ovvder, a ferric salt 
renmitiing in solution. Oxalic acid, also, and nu>st free metals 
similarly precipitate gold, the 8U|>ernatant liquid ai^juiring a 
|nirplj8h hue. 

This is a convenient way of preparing pure gold, or fine ffold, lui 
it is termed, or of working up the gol(! residues from hd>oratorv 
openitiou'^. The precipitate, titter IwMliagwith hydnx^dorie acid, 
washing and drying, may be obtained as a button by mixing with I 



I 



PLATINUM. 



199 



an equal weijrht of borax *ir potiii^siuni liiMulplniie tmd fusing; in a 
crufibk* in a good furnufe. 

3. Add a few drops of fliliite ndiitiinis of staiHinus and 
sUiniii^ chloridi'.s lo a ronsideral)le qujuility ui'dislillfd water; 
pour the liquid, ii srniill cjuantitv at a time, into a %H^ry dilute 
S4>lutioii of iiurie eldoridr, and .^tir wt^ll ; llie mixture assumes 
a |»ur|de tint, and Hocks of a prtn-ipitate, known as llu^ Purple 
of OtHHitts (from the name of t lie iliH^MA'erer, M. Ca>ii*iiJis), are 
j>r<Mlut':ed. The presence of more than a trace of a free add 
iiiUii^t be avoide<L 

Purple of Ca*wtu,H is ill w> l<»rni<M| «ai imiaen^ing ii pifce af I'm 
foil in a *K>lution uf auric ihhirido; it is said to hv a mixtnre of 
auric, aurouHj stannic, and ^^lannous oxides ; but recent experi- 
aienls suir*reMt that it may he nurely ?^tannic acid, nieehaniciilly 
ndorefl with metallic gold. It is tLe coloring agenl in the liner 
varietie** of ruhy glai«. 



PLATDiUM : Ft* Atomic weight, 1933* 

Orrutrrtifr. — Vlnt'umm, like jtrold, <niurs in nature in the fn^^ 
state, the chief wajrecH of supply hcinif Mexico, Brazil and Silieria. 
AIh»yed with iridinui^ osnduai, and other rare metals, it is niet with 
ill tlie fona of ^^ray grains or jinwihT in alhnial dcpositt^, frequently 
■fWociattHl with grdd. It is st*pamt*'d from the soil hy washin^^ 

ffitfM, — Platinum in chictly employed in the forai of Jr»i], wire, 
erucihle?i, npatuhis^ I'apsalcs^ eviipuratin^-dishcs and stills^ for the 
purpoj^"}^ of the analyst and cheniicid aianuructnrer. It it* t*»ler- 
ably liard. lusiblc with vm' ^^rcat ditliculty, ami n<*t disnidvi-sl hy 
hydrochhirii-, nitrit', or Kul|dmric acid; I ait it is sonn^what readily 
attacked hy aikaHiie substances. Jt is dis^solved hy a<|Un rcjiia 
with pnwlyction »>! chh»n>jdatinic acid, IlJ'tCI^,. It forais fnsihh* 
ulloVM with Icial aufl other metals, and with jdio^phnrnUs ho c;isily 
fu>*c<l phosphide. None of tln'st* sii Instances, therefore, nor niJx- 
tures which amy yicM any of them, shonhl be heated in pbitinuin 
vesjHds. Hammered phitinum vessels are the mo**t durable. They 
are l^e^t cleaned by fusing a saiall <|iiantity of pota.ssium liisnljdiale 
in ihem^ and dissfdvin^ out the fys<'d salt by boiliuit; in water. 
They shotiM not he either heatc^tl itr erwded very wndderdy. They 
shcaild only l)e hcaterl in the «p|K'r portion of the HuiiHca t»r liiow- 
pipe-Hanie, as exfjosure to the lower jiarts of thcst* flaiaes, which 
rcmtfiiri ineomjdctely burnt pisi-s, ^ive rise to the tonnation td' a 
brittle eurbide. Hcd^hot platimna vessels shouhJ not be jHTuutted 
to eome into contact with ajiy nnlallie support^ unless one nonle 
of phitinnnu 

The speeifk' g:ravity of ]datinuia at 15.5^ C* is 21.5; and that of 
the alli^ metal , iridium, 22 A, 



200 




TEE METALLIC RADICALS, 



Expeiinienl — I'liice a fragment of platinum m a small 
f|iiantity i)^ 114 iin regifi, and j«ot the vet>Hel tu^ide 111 a warm 
pliice (in a funie-i:ypboard ), adding more acid from time to 
time if necessary; a ^iolution of clilorupiatioic acid, H^PtClg 
(formerly regarded as^ i^imply a solnlion of platinic chloride, 
PtCI ), re&ults, Evapt>rate the wjlution to reoiove the excess 
of acid, and complete the dc4<itTation over a waler-bath. Dis- 
solve the rciiidne in water, and retain tlie solution for m\y- 
gequeiit ex[>erimentH ami \\^ a reagent for the precipitation of 
pi>lai^iiiui and ammonium mlts. Platinum treated in this 
manner, and the re^sulting chloroplatinic acid dissolved in 
water, forms ** Platinic Chloride Test dilution/' U. 8, P. 

Analytiral RtxiviioitH of Pkttinum. 

1, Through a few dro})8 of a a<dution of a chloroplatinate, 
or of a platinic salt to which an equal quantity of a sohrtiun of 
Bodium chloride has been ad<led, ]n\^ hydrogen sulphide: a 
dark-brown pre<-»ipitate of platinic su I i>hide, PtS^, k produced. 
Filter, waah, and adil ammonuHn hydrosulphide ; the preci|ii* 
tate dissolves with some ditlicnlty. 

If sodium chh>ride be not present in the abfjve reaction, the 
precipitated snlpliide will cootiiin platinous chloride, and niay 
detonate if lieiittHi 

2. Add exccvsa of sodium carbonate and 8ome sugar to a 
solution of a chloroplatinate or of platinic chloride, and boil; 
a black precipitate of metallic is produced. 

Fiatinum black in tlie name i*f thiK yirei'ipitate. It possess*^ in 
SI high degree a q utility ((►mm on U\ many Mibstanrex, <»f which 
phitinnm is a nutiihlt* example — that, namely, nf alwtrhinjr or 
oechtduHj ga.ses> In it.s ordinarj^ stirte, after well washing and 
drying, it absorbs from the air, and retains, iiomy times it** own 
volume of oxygen. A droji of ether or alrnhol jilaced on it ii» 
rapidly oxidized, the platinum hecoitiing hot. This action may lie 
prettily shown by pouring a tew drojw of ether into a beaker, 
lm)Ht'ly I'overiiifF the latter with a card, thnnigh whieh there pasw^ 
a platimim wire, the lower end nf which tenninatcs in a short coil 
Mr helix n«>ar the Kurface of the ether : on now warming the helix 
in a flame and then rapidly iutrodueing it ititn the beaker, it will 
liecome red-hot and idntinue to glow. In thin experiment [lartiaJ 
combustion goes on lM?twoen the ether va]Kir and the concentrated 
oxygen of the air, the pro<lu(tK »>r I he oxidation revealing tliein- 
Belveti by the odor (chiefly that of formaldehyde). 



i 





PLATINUM. 



201 



I 
I 



3, To a solution of a chluroplaliimte or of platinic chloride 
mh\ soiotion of amnioiiiuiii chloriile ; a yellow crystaHiue 
precipitate of imimouium chloroplatinale, (NH^j^FtCl^i is 
prmluced. Wheo it ii* slowly forioed in dilute jsolutiotw, the 
precipitate is obtained in tninote orange prit^iniJ. Collect the 
predpilate, dry ii, and heat it in a ^ in all jwrcelain crucilde; it 
18 dee<ini|)0^d, and metallic platinum, in a liijely di%^ided 
gray Btate {Hpottfjy pladnum), remains. 

l*ota»*iu»u chloride, KCl, ^ivea a s^iiiiilar prtHiipitateof (lotassium 
chroroplatinate^ K^PtCI^, Heiit decomposes the p<ttiii*iiuin »ii!t 
iiit4> Pt-i- 2KC1 r^€l.j, the chL*ririe escaping and the pottm«iujii 
ebloride remiiininj^ with the phitiamiu 

The c«jrrei*p(>n<iinj^ »odium compouiidj Na^PtCl^, h soluhle in 
wntcr. 

In working up the pfftftnnm rfj^idues from labm'ai^rtj iip**r(ilmm^ 
the mixture should he dried, hurnt, iMiiledBUCccsf^ively with hydro- 
chloric acid, water, nitric atid, wjiter, then diy-nolved in atpia 
regia, excels of acid heing renjoved hy evaimration. Atnmoidum 
chloride b then adiied, the preei|dtate Wiiyhe*! with water, dried, 
ignited, and the r*.'sttltirig i^pmi^' platinum retained or ronvcrted 
inti* chlorophitinic aeid. It ia liy f^ut^h processes that the native 
phitinuni in treated to free it frmii the rare metals palladium, 
rhodiuut, os<minm, ruthenium and iridium. The spongy j>latinuui 
itt eonverted into the nnu<Hive c^indition hy hammering it when hi>t, 
or hy fu8mg it in the flame (jf the oxy hydrogen blowpipe. 

(k-chmon of (jtuen by upont/y p/a/httim. — Spongy platimnii has 
great power of oeelmtion. A small pieie held in a jet nf hydniireu 
which is^ escaping into the air, cau>**"i4co(nhi nation of the hyilrrpgen 
with the oxygen (of the lur) occluded by the jdatinum. Thf heat 
given out by thi** coinbination eventually rjiise^t the [>latinum t*i a 
reil heat and the ri*d-hot j>Iatimnn kindles the hyckogen jet. 
Pol n' re i tier* R #«eir-lighting lamp wan rauKtrneted to take advantage 
of thi^ [►r<iperty — the appanitas being essrntially a ve.sHtd in which 
hydriigen wilh generated hy the uilion of dihjte sidphurir aritl *ui 
sdni*, and ho arrangetl that on opening the Ht^>p<'m;k a jet *if 
hydrogen iuipingeti on aome spongy phitinum enatiiined in a small 
cage. 



QUESnONR AND EXERCrRES. 

I)ip|||ic iinntont^ *trmm*Hn, Mttrk^Hnf prmn-tin, tin pltite^—Whnt It the 
iliffiTrtire between «t«mii€ iiHcl and mctnstannir arid '/—Stnti' tho ufipMeji- 
tiuiiM iif tin bi tht» art>».— Mviiti'iii thf fhit'f teKU fur At40inr»iis amd HUmtiic 
«lt«<.— Nmm* tU** bi*«t aiititlolt- in cum^h nf f>r>is<uiiiiK l\v tin Hf»lulioiis.— 
How in ijold dUHt se|mr»tt'd from the earthy oiutttT with wliith it ir 
liAt u rally aMoriati-il?- Seal f the averajje thiekiu^tw of jrnld leaf.— Whsit 
eflW't itt prrMjured i»n j^old by hydrcM-hlnric, niln*" and iiitrohyflnM lilurh' 
acid)* n*m»ectivt!ly ? — Hy wliiit rrageats may itictiilbc- jfold lie jin^'iiiitat*^! 




a 



202 




THE METALLIC HADWALS, 



frtim 94ilutioii ¥— Hi«w in '' ^niriile of C&ssiiis*' propared? — Whence is 
platiiuiiii fiblmned ? "Why are platiiuini utensib jii^ciiJinrly mdiipted for 
use ill chi'iuiical ltth■{J^lt^^ri^^'^ 'f- lluw is cbhtrdplntinit- acid prepari'd? — 
Niiuji' the chief ic^ts fur platinunu — What b "platiniiJin bliM^k "Y^Whiit 
is meant by (jrduww *>f gofitt*'/ — IX-scribe \\\\ experiment illtiKtnitiiiif the 
jktwtT uf meUidiiiK K"-*'^'''^! p«jHSt'4vsed by melHllie phitiuimi. — U*iw is 
**sp«mKy philinurii" prmlut'ed?^ — By wlmt prtjcens nijiy phitinnm be 
reeoverL'd iVoni residui-s? 



Directions for applying the REA(7ri()NR described in 

THE FORmJOINt; PARAURAPH8 TO TIIK ANALYSIS OF 
AST AQUEOUS 04UATTION OF A (OMIXJUND OF ONE OF TIIK 
ELEMENTS ARSENltt AND ANTIMONY J Al^O OP TIN IN TILB 

FORM OF A BTANNMi! F«ALT.^ 

Aeklulate llie Fmuid with hy<lrt>chlorin aei*], ami |>ass 
hydrogen sylphiile through it:^ — 

An t/rantje [ireeipitiite iiidiriiteb^ atitiinoiiy. 

A tftMow prec"i[jitMle iinlifatfs ar^fcnic or a stxiuiiie salt. 
To distinguisfi hftweeii fit^eine mid Htaniuc Hiilt, te;*! the 
(*rigiiml Hihilioji with animoiiiii wattT tmd witli |Kttii>a*iuiii 
liyiiroxide. Ni> [ircripitiitcs: a i*senic indicated. For hehavior 
of jitiiiinic i^iih eonipiire p» 19*1 

The resulUi may be coiitirnied hy tlie ai^plieatioii of otfier 
testK 



BlRE^'riUNrt FOR APPLYTNf! THE REACTIOSS DEHfRIBED IX 
THE FtmECKKNCi PARAOKAPH.H TO THE ANALY81H OF AN 
AQUKCJl'H HflLUTION OF COMFOUNDH OF BOTH ARSENIC 
AND antimony; also P<jSSrBLY CONTAININO TIN IN THE 
FORM OF STANNIC SALT. 

Acidulate a small ixjrtion of the rupiid with hydrochloric 
acid^ and \u\^ hydrogeu i^id phidt? through it. 

Nofe 1. — If the hydrogen Hnl{>hkle prtHipitate i>* unruifttakuhly 
oningf% iintinioiiy may be put df>wn a* present, and arst'uic only 
furtlior sought hy the application of Fleitmann's t6«t tu the 

^ KtHiirik solution!* an' nirt'ly nu't witli, but thfj*i* ^oliitimifl aw? deiilt 
with hcr(\ And in th<* umilytirti! dinetifuiH imiiii*dii*tHy fidlowing, 
Iwcttns*" irt l\w oniituiry eiu»n*i* nf systeninrip anulysis. tin (whethi?f 
prt^scnt ctriirinaUy iw htnniHuisorasHtarmir salt) is cvt'iituully prtn-ipitutiHl 
as yellow «ittnnic Hulpliidr atimt! wilh ar><ciiir and autimcmy snlphtdvs, 
prior to iU ftepumtion from arMrnic nnd mitiinony. 




q UA LIT A TI VK A NA L YSIS. 



203 



original solution, or U> the nolution of the Hulphides in arjim regia * 
frvini t'Tifin Kulpliur liy hoilitijji;. 

Xott 2. — AntimoriioiLs sulpliide is tar lens reailily s^ilubU' tliuii 
iirsenous Kul|»liitle in dilution of iiniiiioniuni cjirijonute. But 
Ihis fart jHissk'SHes Hniitt'fl aualytiad vsi1ul% siurr, in the citne of 
mixtMj Huli*hides, niiuh siiitiuKtuioxiH ,sul[>hi(lt' nil! |*r(.'V*-ot u suiall 
<[ujuitity ijf :irsen<>u>i sulphide from Ixing dissolved by tlie auimo- 
iLiutii ciirlMmjito, while inueh iirj^^iinus isulphide will earn' a suiidi 
fiuantity of antiiaoiiious sulphide into the iW>lutirMK \Vheu the 
pniportions are, apparently, fruin the eohir of the preeipitjjte, k^s?* 
wide, scduti*m of ammoniuni I'tirhonate nuiy s^nnetiuiet* In.' tbuud 
UM^ul ill rou^iily st^paraling the one sulfthide fruni the other. 
On filtering and iieutrali/injj^ the alkahue s<dution by adding an 
aeid, the yellow arsenous suljdnde i^ repreeipitated. The orange 
aniiunnHou-* sulphide, and any stiiiniie sulphide present, will 
retnaiii mi the filter, 

Xotf^ ;}. — 8ohition of pota^Hsiuni liydrogen saljihit*^ is said by 
VV^Vihler to he a ^ood reagent for separating arscnous antl anli- 
monious suljihitles, the former iK'ing soluble, the latter instduble 
in the liquid. 

A^otr 4. — Another reiigent for R'parating arsen<M»s from aiiti- 
inonirHLH and stanifie sulphides is concrftfraird hytlroihlorie aeid. 
As little water a^* possible must he prest*nt. (hi iMaling, auti- 
monious and staiinie snlphides dissolve, whiki arsenous Huljdiidt* 
remains jnsithdde. The Hi|uid, ?4lightly diluted, h Ik' red, mixed 
with mf*re water, and aguin treated with hydrogen suljihi^le, givin* 
orange anti monious sulphide, mixed with staunie sultdiide when 
"in \n prenent. The f^resenee of arseuie may 1k^ eonfirmed hy the 
|»plicatiou of Fhdtuianii's tr^t to the original solution. 

The two |»roeesj^.^ now U) he deseribed for the deteetion of 
ttr?ienie amd antim^my are ratiier hmg, and require auudi eare in 
their perfurmanee; but rliey are *iMrtuf InH-ause a Hmall quantity 
of antimony in preMenre of mueh arsenie, (>r r/Vy irrM, may lie 
ilvt*i*'U*d by thtMr means. The nu'tlnnJ for detecting tin will be 
detH;rtlK*d litter (]»» "iOr^.) 

Detect wn of Ari*tuie apif Anfimomj. 

First process. — Generate by^lrogeu, ha for Marsb'^ test 
(\h 179 J and piis8 it through a snuill wush-hottlt* miitaioing 
l*ohiiioti of le^id aeetiite, to free ihmi any truce of hydrugen 
llphidti, and then ihnuigh a dilute iiolution of ?^ilver nitntle 
[>ntitiued iu a test-tybe. When the hydrogen nppuratus is 
in go<M| working order, p(jur into the generuting bottle a 

• Aqtui R^iiin ia a mixture nf hyiJr<MhU»ric imd nitric mid, Addnm 
Nltroh^ftrt^rhforicum, U* S. P, It wha hti-ralk-d (mm Hs property of liis- 
solfing Kultl, ili« "king** of mt^talti. 




204 



THE METALLIC RADICALS. 



quautity of the original Bolution to be examined, atldiug it 
gnulually to prevent violent actiou. Alter tlie ga^ has beeu 
pasi^ing tor five or ten iiiiDiite;*, exiiiniue the eouteuts uf the 
test-tube; iirseuie, if prest^nt, will be fuiiud m the solutiou lu 
the state of arseuous acid,— 

AgH, + 3H,0 + 6AgN0, = H.AsO, -f (5HN0, + 6Ag ; 

while antiiimny, if present, will be fouud iu the black pre- 
cipitate that has fallen, ac-eurdiog to the foUovviug e4uatioii: 

SbH, 4- aAgNO, = SbAg, + 3IIN0, 

The arsenonw radiail may be detected iu the clear, filtered, 
auperuatnTU lif|uid, which still eontaiua much sih^er nitrate, 
by *'autiously ueutraliziog witli very dilute amuiutiia water j 
or by adding a few dro|>s of solution of silver anirnoiiiyn 
nitrate, yellow silver arseuite being produced. The antimony 
may be detected by washing the black j)redpitate, b<uling it 
iu au open dish with s<dutioji of tartaric acid, adding hydro- 
chloric acid, filtering and |>a8i<ing hydrogen sylphide through 
the »idiitiou, orange antimonious sulphide bemg precipitatetl. 
( Hofmanu. ) 

Second process, — Obtain the metallic deposit in the middle 
of the delivery-tnbe as already de**<Tibed under Marah*** test. 
Act on the dejwisit with hydrogen sul|ihiile L'as, and then with 
hydrochloric* and ga«, as detiuled in reaction 3 of aniimooy 
( p. 191 ). I f botli arsenic and antimony are }>reseut^ t he defKisit, 
after the action of hydrogen sulphide, will lie found to Im* of 
two adors, the yellow art^enons snlphide Ix'ing usually farther 
removes! from the heattnl |K»rtion of the tube than the orange 
antinionious sulphide. Morciiver, 8nli:^t*fpient action of hydr«t- 
chlorie acid gas cau8e>s tiie ilisapfiearance of the antiinonious 
Hulphi(k\ which 18 converted into chloride and carrie«i off in 
the Klream of gas. 

The chief objection Ui this process h the liability of the operator 
miKtaking t*ulphur, deposlttHl from t!ie hydrog^en anl]ihide by the 
action of heat, for ar>«enonH sulphide, Hut the presence nr ab^'nce 
of ar»enic ii* easily continued by applying Fleitaninn*^ te^t to the 
original solution, while the pmcens is moHt uJH^tid for the deteetiuii 
of a «inall quantity of ajitiniony in the pres^»nce of much arocniiu 
On the whole, Hotinana'H jiiethod m to be preferred. 



COPPER, 



205 



Detection of Tiiu 

During the generatinn of hyfln:»g€n arsenide and antimonide in 
Man^h's apparatus, any stannic ihlciride [)rew*nt in the originfil 
»oluti*»n under fxiimiiiatioii in ^nidimlly reduced, vvitli deposition 
of iiH'Ljillic tin. After the ti>iting fi*r nrneiiii' and antimony m 
concliideci, pour out the eont^^ntn of the generating btittle into a 
diji^h; take out the fra^nieuLs r*f Kine^ tir^t detiiehing from them 
any hhuk jiowtU-ry or .spnngy deposit; &^ejmrate the liquid hy 
Ahrjition aiifl \va.sh the residue (whicli eontainn any reduced tin 
toj^ether with inii>uritie8 derived froai the zine). Boil the residne 
with a smali quitntity of dilute hydrochhirie acid; Hlter, if 
nece8»i4ry, and te>?t the ti Iterate fi»r stannous nalt by adding no-r- 
curie ehioride. A white preeipitate of niereurouH ehlnride indi* 
cates the presence of tin, (Compare p, 221,) 



The student may now proceed to the analys^is* of aqueous solti- 
tionH of sialtH of any of the metallic element* hitherto eonnidered. 
The method foUowc^fl may l»e that ff»r the separation of the pre- 
vious three groups^ hydrrigen wulpiiide being tirnt paKsed through 
» theH<dution to j^recipitate arM^nie and antimony (al^o tin, if nt^innic 
' mil be present). The liquid, after the removal hy tilt rat ion, of 
any hydrogen t^ulphide preeipitate and ehullition to expel 
hydrogen ^idphide, is examined by meann of the other group- 
kfeagent* for metals of the ir*)n, ^inc, barium, and inagjiesium 
'irroup^ and then for alkali aietaln. (('onijiare pp. lOii, 128, 145, 
170, 17L) Three or four j*<jlutiiin8 at learnt siliould be exaanned 
before prot.'eedin^' tn the next group <»f metalf* — cfqq>er, mercury, 



etc. 



» COPPER: Cu, Atomic weight, 63.1. 



ffr, — The connnonest ore id' thi?^ metal is mpp^ 
pyritr^^ a copper ami iroji sulphide, CuF^sS,^ occurring int'ornwall; 
AiiMralia and Kn^sia f^upply ma}fwhlft\ a hydroxyearbomite; nujeh 
ore is also importeil from Spain and from S»uth America. It 
i« wnelted in enttrnioufl qmiiititier* at Swansea, Siaith Walcj*^ n 
liK^ality pcHuliarly titl^Hl for the uj»eration on account of its |>rox- 
imity to the eoaldield, and \U jioHition lu^ a neaport. By Hollway'« 
IflH'onoanca) method of smelting copper pyrities and other sul- 
j>hidej*, arter the nulphide if< once nteltedj air m driven, ni»t over, 
ju* UHUal, but through the juass; the condnit^tion of the sulphur 
th«'n iM^comcj* s^clf-supporting, and is greatly aeeelerated. 

The alcheniii^tj* termed this nreta! Vfuntf, perhaps i»n aeeouiil of 
the beauty of it*» lustre, and gave it her symbol V, a compound 
hiemglyphic also indicating a nnxture of gold © » and a eertjiin 
hyp<»thetical snhsliiTjce ealleil acrimony ►}*, the corrosive nature 
of which wa.H syndK>liz(Hl hy the points of a AtjUtcse eros«. To 
tliia day the blue show-liottle in tke«hop* window of the pharmacist 



206 



THE METALLW RADICALS, 



iH fwca^rVjnally (irnaiiifntefl by Rich a »ymfcM>l, indicatin§^, paasibly, 
that thi' lihie Ikjuid in the vefi^sel in a preparation mI' <.'fipiitT. 

(Vip[K'r forms two sets ofsfill^, wbieh jut (listings ishetl i\^cupnc 
aiul cHprom Halts, jrnd may l>t* regarde<i m.h related U\ tlie oxide 
UuO and fu^Ut respectively. Cnpric oxide, or blaek v\y\\\}et 
oxide, TuO, may be prepared by be:itin»r t"ra|^ment?^ of copper Uy 
low redness fm it piece of earthenware in an <i[Kn\ tire. (.'npriUiH 
iodide, Cnl, will l>e «nbs<H|Ueiitly referred t^t as a convenient ff*rm 
in wbieh hv reniovc ii Kline from f^dution, while the formation of 
ciiprouH oxide, Cn/)^ nnder given circnm!?itjince>i, will come under 
notice an mi indicator of the presence of sa^ar in a liquid. 

vih'ml, biitt' »fffftf\ or t^uppa* ntuiphatr. is the only eo[i|>er eompouiid 
much used in jdmrnia«.'y. It i* a by-]inHluet in silvur-rehniJig 
(Ag.jH()j f Ou==rn*), I 2Ag). H^nne is formed in roasting cfipiKT 
pyriteH. In the latter eiLse, 8onie iron sulpbide and copjw^r sul- 
phide are i^xidtzefl to *^ul|dmk*i^; but the low red beat finally 
employed decon»[>oses the ferroiij^ sidpbate; while the eupric sul- 
phate is niiaficfted; the latter is |>u rifled by crystal liziition from a 
iiiit aijiifoas sohition. thoiigli fre<piently mm h ferrous sulphiite 
remains in the cry^'ttds. Cnprie sulphute is also preparetl hy 
disstdving in dilute stdiduirie acid tlie black oxide. Cut ), obtainw! 
in annealing copper plates (Uu0 4 H^1^0^=CuS(\-f H/>); it may 
also be olitaineil bv boiling copper with three times its weight of 
Hulphuric acid (2'H,S()^ f (M =^ CuSO^-i-8(\ + 2H,f)), diluting, 
tiltering, evaporating, iimJ cPkStjdlizing. In this process aome 
hbtck in p rials suliddde also is formed. 

Afih*jftn>u» (*Hprif Sitljihaff, ('iiSO^, is a yellowish-white powder 
prepared by depiiving the iirdinary blue crystals of eupric sul- 
phate tif their water of crystal tizat it in by exposing them to a tem- 
perature c*f about 400** F. (204*^ C.J. It is uscti in testing alcohol 
and simihir spirituous liijuids iut water, becoming blue if the 
latter be pre^sent. 

Experiment.— 'Cwprtc A^ifmte.— Digest c«jpper in dilute 

nitric acid. When action hiw ceased, evajMu-ate and crystal- 
liKP. If the crystals form at a tem(»envture of T^^ to H(_P F. 
< 22J to 2«i.H° C). they are iirismatic, TufNO,),, *iH^O; at 
lower temperatures, lahuhir, (\j( NOj)j,tiH,<>. 

:iC;ii + 8HN0^ ^ 3Cii(NO,), -f 2N0 + 4H,0 

tupjjiT Nitrlt! ucld tuprh.* lu^ltl Nitric oxide Water 

Verdigris (from vtrdi-ffriif, Hp., grt?€ti-gray) is iJopper Oxy- 
iicetate Cii.jO(( 'J l^t ),,)^, obtained l)y exjKisin^'' alternate layi^n* 
of eup[>er and fermenting refus*e grajie-biisks to the «elion of nin 

The mmiei* <d* forming Cnpric SnI/ihid, iiijdntjridf, 0,ride, 
Ferrorymtide, and Arnenitr, aw well ns Mvtaftic Cnpfier^ are 
incidentiiUy iiUuded to in the following atuilytictil |mragraph8. 



COPPER, 



207 



Analytical ReticfhuH of Cupric Suits, 

K Fiu^s by<iro;^eii ?^yl|»tviile through ati addulateil *5olutioi» 
of a t'uprie -*alt; ii lilark prrcipitate of cyjjrit^ i*iil|*hi«fe, CuS, 
ie prorliieeJ, wliicli is insolulik' iti dilute m'uh. 

2. To uti H*iiHous sulutiuii of a cu|>rir i^alt add amniooiinn 
hyfln*sulj>hi*le; Ivy tliis rt^Hgeut, al80> cupric suiphidL^ Ls pre- 
ei|jital^d, iiiisululde iu excesa*. 



AVc. 



>lude i 



I 
I 

I 
I 



: altogether iiis*duhle iu aiiimoiiiuni 
hydr<»?<u!idHde if fret* jtaiiiiniiia nr muih lujiinnnium ^ydt be present ; 
it b iuHLiIuble in potasftimii and Hodiuui hydrosulphides. 

3. Immei*f*e a piece of iron or steeli sueh a^ the jnviiit of a 
penknife or a pier'c of iron wire, in a few dni[)8 id' a Holmion 
of a euprit' wilt ; rofiper is dejMisiled on the iron, with Ua 
characteristic eolnr, an erjuivalent quantity of iron |ui*ssin«: iuto 
solution. If a snfticient tjuantity of iron is eniployed and the 
experiment h alloweif to continue long enough, the eopi>er is 
entirely preei pita ted ^ — 

CuSO, f Fe=r.FeS(:\ | Cn 

By this reaetiou €<>pj>er may he recovered ou the large scale 
from waj^te mdutions, old hmvp or other scrap iron l>eing thrown 
into the liqnorH, 

4, Add anjuHUiia water to a Holntion of cupric sulphate; 
cupric hydrcjxide, Cu(()H}^i of a ligld-blue color, i-s precipi- 
tated. Afld exce#« of amujoida ; the precijdtate is rediss(dved» 
forming a bine solution of cupric annnonium salt, so dee[r in 
nilor a.*« to render aruruonia an exeecdingly ^lelicate reagent 
for copiMfT From thij* am i u ft in a en 1 solution alcohol preeipi- 
late» a ilarkd>lueeryf*lnlliue mass fruSO^, 4NII,, II/J) which, 
on heating to Ifd)*^ C\, loses water and two mole^'ule^ of auuno 
nia, Iweoming <*nS(>^, 'iNIl,,, and at 200^ ('., it loi*ei* another 
moh^njje of ammonia, iMM'orning CnSO,, NH,. Other soluble 
cupric ^altfl yield .sindlar com [xm mis. 

A ruprie anmioninm suljihatc mny hv obtuiaed iu Ijirge crystals 
by lohling Htrmiger jiiaiuoiiin \vj*ter to jNiwdered ruprie suljdinte 
until the sjilt is dJHSfdved, pbu-ing the ii<|uid in n ti.^s^t-^lu^kH or 
cylinder, euntiously |M»iiriiig iu twice its vnluuie ofaeiirly nnhydrouM 
nicuhol or (iietliylaied s(>irit, taking rare that the liijuidn do not 
b«T<Mnr iidxrd, tying a piece of hljidrtrr over the iii*>uth »>t the 
vri^tol, and setting iislde tor souie weeks in n c<m)1 place. (Witt* 
ifteifi). 



208 




THE METALLIC RADICALS 



5. Add a solution of f>ota««iuiii or sodium hydroxide to a 

ruprir solution ; cupric Imtnrxide, Cu(<)H )., is prei*ipiUited, 
ius^oliible in exeens. Buil tlie luixlure in tho test-tube with 
excess «>f (w)tas.siuni ur ^ioditmi hydroxide ; the cupric hy«lrox- 
ide is decoTiijKjsed, lanitig th*3 Lderneiils uf water, and het-oinlng 
convt^rttnl into lihick utihydrous cuprii- oxide, CuO. 

\y. Add Milutioii of p»tassiiirii ft-rrocyiHiide, KJ^'etV^t toau 
ii(|iitHin!? cn]>ric Holutioii ; u rechllsb-l>r(JWo precipitate ofeupric 
fentK-yjinidt', Cu^FeC y^, U jjrodiiced. This is iiii extremely 
delicate test fur eop|rtT. 

7. Add solution (tf iKitiii5.siujn iudith^ t*> an ai|ueoU!s eujiric 
«<»liltion ; in ruodenitely eoTieeulnitefl solutions of a prtH-ipitJite 
of euprous iodide, Cul, is produeed» with sinmluincoiij? Iil>em- 
tiou of iodine which imparts a yellow or hrowu color to llie 
solution. 

2CuB0, + 4KI JK^O, 4 2CuI 4 I, 

Oil adding to the mixture aBcdution of sulphurous acid (or of 
ferrous suljihate), the ctdor due to the free iodine is removetl» 
iind the nearly white cuprous iodide cau be recojiruized. Even 
in very dilute cu[)ric H4>lutiuns a yellow eoloration is prothieed 
on the additiou of jmta^aiuui iodiile, which btn/omes violet ou 
the addition of ntarch pasite {iiee Iodides), This te*«t in even 
more delicate than theferroeyanide tet?t, hut eare must \w taken 
to a^'ertiiiu that the solution of |iotas8inm iodide employed 
doets not contain frc^ iodine, 

K To a cupric solution add stdution of nrseoous acid» 
and cfiulionsly neutrali/.e with alkali ; green eupric arseoite, 
i jjHAsOj, 1:!^ produced. 

Mo0t copper salt8 impart ii L'^reen eolortothe Bunseu flame. 
(•upric chloride imparti^ a bluish color. 

Antidotes, — In cjises^ of jKasouiug by eonj|x>uiKk of copper, 
inin filiup^ should )>e udmiiustered, the HCtlou of which is 
explained ir» reaction 3. Potassium ferrocynuide mnf alsi» be 
given ( ^'''* reaetion 6), Alhundn forms with citpp**r snib? a 
cx>ni|>ound ins<duhle in water, hence raw eggs may Ih^ admiuii- 
tere<t vomiting being induced or the stomach-pump, or 
stomach-siphou, applied as sjieedily as [xissible. 



4 



4 



MERCURV. 



209 



^ 



QUESTIONS AND EXERCISES. 

Nnmv the noutcea of copper.— Give eqiiatioiiR showing how Ciiprio Sul- 
phate is preimrf^d tm the sniiiU iitid lur^o B<!til<?,— Ciiiouliit« Iwn niiu'h 
(VysUllizcd Ciipric Sulphate may be olUained from 1(K> [tiirtn i>f nj|irit! 
^•ulplikki. Ahji. *2*I1.D5 |>iirts. — Hnw may t'liprit'; Ujiklc be prppiinHl ? — 
Wrilcdown Ihe formula of VortlifsTis. —What U the iitmlytir;il jHisitiou of 
copper? — Meutioji thi* chief tewtj* for copptir.— How may iop|n.*r Ix' »etja- 
raCed from arsenic ?— Why ia firudy divido^i iron an aiitidute iu iMiLHouiug 
by c«>pper? 




MEECUBY: Hg. Momk- w*^ight, 198.5. 



OrrurrenfT, — Mi^ctiry *K"t'urw in luitiire a^ .'*nljdiiih-\ HgS^ foriii- 
ing the om cinnnlMir (an hi<liati rmmt' rxjire?vsivu fdHoniettiiitg jvd), 
itnd is o!)tjiHiiMl from Spain, t ■.ilifornia, EjLHteru Himgar}', China, 
Japjiii, and Fi-riL 

iWparnthtu. — The metal U sieparatiMl by nmstitig olftlie Hul[diur 
and thi»a di»tiHin^ ; or Ijetter, liy distillin^r with linir, whiihcom- 
liiiu*j4 with and reUiiiiH the wiiljduir. 

Ff*tpf*ffit\^, — Mi^n-yiry (Htjfirnrtft/nim^ ll« S. P, ), is a y^ilver-white 
luMri»u«( luetalf li^juid lit iinliniiry tenija^ratareti. It biiih at 1>75*'F. 
(:?57* C), and at -811^ F. (-41*'^ C) solidifies to a aialleabk* nui>^ 
of cM^fahed ral erynta Is, Its ?>peeifie gra v\ ty in 1 ^i» r^if). When ^n ite 
fret? from other jnetidH, it doen not tarnish, and iU glohules roll 
fn^ly over a jtheet r)f white paper without kavin^ any streak. 

Ff*rmu/a, — The fonnula of the tnerrtiry inohM^uli' is il^ and not 
Hp,, lifi*auMc? (at all events at the hi^h temperature at wfiieh alone 
the weight of itM vapor can he deter*niia'd) the *|ii:intity of nierenry 
va|K>r which iwenpien the Ktine ^pnee as thtit oeeiiided by 2 ^ntnunei* 
of hydrrije:en under the same eonditionn is lllKJ^ grannnes, iind not 
twitv this iptaiitity {Jtre p. 5K). Anabi^f»ns laets bave been 
oliservwi with refereaee to the vajiorn of j^ine and cadiniaaL .Mer- 
ciirj% like iron, co[iper, ete,, forni.H two H<'ts of *^altH. Thes*:- are 
ealKn^l nierenrous and ineretirie salt*^, and eorreHpund to the oxide>», 
II|r.O ami 11^)^ renpeetively. 

AmaltjaitiM, — The mixture or eoniponnd fonned on fnsiu|^ metals 
tcigether is usually termed an ^?//m/ [ndwwA fitfo, I bind); if mercury 
ifl a ef)nHtituent, an attififtjam ifiiiAfi/fmy maffupnti, from ^mVfWffut, 
mnltiAm, I sotlen. the presenee of niereun* hiweria^ the meltinj^- 
IMtitit of sueb a mixture)* ^fost nieUi Is form amalgams. Eh^tn^^ 
nmaltjnm^ the exeiting material which is nibl>ed against the >rlas?4 
plate of an eleetrieal machine, eomnioiily consists of 1 partciieh of 
tin and 74 ne with H part-*^ of mercury. Sodium amaluauj hrw alreatly 
Uvii rnentionetl (page M4), 

Afrtiicinni (hmpttuntU, — The Cfimpnifiids of mereury Us<'d in 
filed ieiiie are all obttiiaed from the metal. The metal itself, rub- 
l»f<i with chalky or with e<tnfcclion t»f ro«e« and powdered liquorice- 

14 




210 



THE METALLIC RADICALS, 



rmitj or with hird ami suet, until globules are not %isil>le to the 
utiftifM ff/t't is ortvn ii,«cd in nuniirine. Tlie prepamtiuns are : — 
Htjdi'tirfjijrum cum iWM, V. S, J*., or Gray Powder; Mtima Hi/firar* 
fjtjn, n, S. P. ; Umjueiitum Nf/drarfftfri, U. S. P., Mert'urial ( iint- 
mrnt, and Unrjufntnm Htjdraripjri Diluium, U. H. V,, Blue Dint- 
mt^nt. There is nho nn otfirial MtTi-nrial PhLster {EmpkiMrum 
Jltfiimn/i^n). Their thi rajH'iitit: eiftLt.s are prtibahly due, u*rt ti> 
the lartre fjiiantity of niet^iilit: nit'R-ury in ihom, hut to Kinall cjujui- 
titie^ of lilack and n^l oxide which mt iir in tliem thmnpjh the 
aelioii <d the nxy^iren ol* the air on tlie Jinely divided metiiL The 
jjruportiofi of oxide or oxiile,^ varies aceording to the age of the 
s]ieeinien. All thes^* medieinal jn-eparations of iiietjillie mercurj' 
are indehnite mid unssitisfat-tory^ nnd that Ihmugh no fault of the 
idnirinfieiHt. They nineli JteeVl investigation hy pharmacistg and 
therapeutists. 

Mereuroiis and Mercuric Iodides. 

Experiment 1. — Riih to tjet her small fjuaTUitie« of mercury 
iintl iodine, eoiitndlini^ the rapidily of eomhiuidion Ijt addin|r, 
at the outHi4 and at intervals during thtiojundion, a few dmj^ 
of aleohol. whieh liy evaponititio al^^jrhg heat, and thus keejis 
down the teEnperature. The j>rodut*tis;eitherniercurjeiodide, 
niereuroiis iodide, or a mixture of the two, to^relher with mer- 
cury or iodiue, if excess of either has i>een employed. !£ the 
two elemeiiti* have been w*ngbed out in atonde |irojxirtioiis, 
198J^ of mercury to 125Jf of iotline fnl»ont H to 5), a green 
r gray ish -green po w< le r ren ii i tn in ) n 1 1 1 1 ei r u n i < in » w h i < di eon s ists 
chiefly t>f otercurous iodide. Pig I; if in tlu^ proportious of the 
atomic weight of mercury to twice that of iodine (UJ8,3to 
twice 125.9, or about 4 to o }, red mercuric iiHride, Hgl^, results 
— au iodide that is official^ hut marie in another way (^c<? p, 
2n ). Mercurous iodide should InMuntle and dried without 
heating, and with as little exposure to light as jKia^i^ible. Mer- 
eiirie iodide may be removed from it by well washing with 
alcohol, ^[ercunjus iodide l Ihjdrarcitjn Ind'ulum Flamtv^ 
V. 8. P.), can also be obtained as a bright ye) low precipitate 
by adding a solutiou of [wMassium iinlide to a s^dution of iner- 
curous nitrate, Cii re being taken that exce^is of the former is 
avoided. {See reaction 2, p. 220). 

MerrurouH i<MHde is deef>iii|Hised slowly by exposure to li^ht, 
and cjiiiekly l>y tlie aeTinn <»f heat, into mercurie iodide and mer- 
cnry* Mcreurie icKJide, oeeurring hk i\u injpurity in mereuroii« 
itHlide juay he detected hy digesting in ether (in whieh iiicretifoU!* 
iodide i« ins»fdnhle)» filtering, aad evaporating: to dryness; mer- 



4 




MERCURY, 

curie itxiide remains. Mercuric ificlide is PtAhle, find may he 
8iibliiiietl in ?*4'arlet cn's*ta!s without decompiwitiitri. {For the 
niet-liiuncHl lielaijH uf the rnetliud by which a npi't-JDien of the 
cmtals muy be ohtained, and the fjrecautions to be obsserved, see 
eorrminc itub/wuite^ p. 213). 

Rnf ttnd Yrfhw Vitrlt'fif'Jt of J//Tr//n> ImUde. — In rondeiining, 
inercuririfKhile is at firHtyenow, atU*nvardaL'<^uinng itw eharaeter- 
wtic scArh't c<d<»r. This rnay Ih^ sh<iwn by smearing or nihl^ing 
a sheet of white paper with the red iodifU^ and then hnhiing the 
*<beet before a Hrt^ or over a flame for a few seeondK. Art wxin a« 
the paper t)eeomes Mufliciently hfjt the red iodide cJiaiigeH to 
yeUow, ami the silt does not ^juickly regain its red er>|tir when 
cohl if the jmper is airefnlly handled. But if the sitlt lx*-[>ressed 
or nihhe*! in any way^ the portions t^ajehed imaie<Uat4dy return to 
the searlet condition. These eoh^r ehiinjpres are aei'<mipaiiied by 
changi^ in erystalline form. The red moditieatinu, stalde at 
ordinary temperatures, forms t4nragonal cryj<tals; the yellow nio^li- 
HeAtion^ rhombic crystals. 

Experiment 2* — PrejMiraliaii of Red or Mercuric Iodide by 
Pr^cipitatum^^To a itnv dro|>8 of a sol nt ion of a mereuric 8ii!t 
(corrosive sublimate, for exarnphv) adxl Bolution of pjtassium 
iodide, drop by drop ; a preeipitate of niereiirie iodide fornrs, 
and at tii'st redij<i<rdv(*H in the exees^H nf the niereurie salt, but 
\h iHTuiauent wlien BufHeient in^lido htui l)eeii added. C'ontiuue 
the addition of j»otH*ssiym iodide ; tlie preeipitate in redis^^dved, 
with formation of p>laHHiuni meretirie iodide, KHgl^^. 

HjjCn + 2KI ^ Hgl, + 2kXn 

Merrurlc chfortdc Potaitftium iodide McrcuH*^ iudide Foupsfu in chloride 



^^^Jljfcunc 



Ilcrpiirlc icHlfdt^ 



+ KI 



KHkF, 

t'otajijitum mert'arle Iodide 



— When first preeipibited, men iirie i<idide is yellowisli- 
re«l, but soon ehang**s to warh't. Itw sidubility eitlo^r in twiluti^ai 
of the mereuric salt or in sohitJon of potaf^ium iodide renders the 
detection of a small «piaiitity of a aiereurie salt by means of pot;!.-- 
mum i«xlide, or a saisill i|imntity of an iodide i>y means of a n)erearir 
sfihition, diffienit, and henee lessc^ns the value of the reaction as a 
tesit. But the reaction is ini[Kjrtiint iis the ofhcial niclhnd tor the 
{treparatioo of mereuric icalide {litjdrargtjri hdidum Rubntm, 
U. 8. P.). Men'iirir iodide made in this way has the sanu: com- 
IKMition aM that prepared by direc t eoiobination of its ch^menls. 
In making the prej»aratif»n, the two salts nmst lie U!*ed in the pro- 
|H>rtion of Hg<M^ (^f^H.HH) to 2Ki (= :^2H.f»2). The mercury in 
mercuric or mercurous iodide is st*t free, and sublimes in glohulei*, 
on bctttiDg either powder with dried Midium carbonate in a test- 





THE METALLIC RADICALS, 



tube; lljt' icnline niay W cli-teeted by digesting with sodium 
Iivdroxide ?^*jliititm, fiU^^riii^j luid to tin* s(iluti*>n fit'siKliiiin imlide 
tliii!< formed stddiii^ i*t4irrb-piistt\ iifidubitiiig with diiule hydn> 
ehlorie or Kilpburic ticidp and adding h solution of a nitritt", when 
bbu^ jstareb iodide remilts. Mercuric iodide is iiiBoluble in water, 
}<lightly scduble iu aleidiob tolerably soluble in ether, 

MercuroiiB and Mercuric Nitrates. 

i^periment 3. — Pbiee a t!;lobiile of uiemiry, about ha 
the size of a jieii^ in a te^t-tube ; udd Hveuty or thirty dro|js af 
nitrk' ami ; boil slowly until rrd i'lmies no bui^er form ; eet 
amde. On eofdinj:, if a globule of nienniry Ptill remains in 
tlie tubt% cryi*tals of tnerciiroirs uitrate s*-|inratp, Then*- may 
be dii*solved in water slightly acidulated with nitric add. 
Tlie solution may be retained firr stilijietinent analytical 
operations. 

3Hg 4 4HN(), - :iHgNO, + 2H,0 + NO 

Erperiment 4, — l^bice mercury iu eTcetiS of coueentrated 
nilrie aeid, and warm the mixture; niereuric uitrate is fornie*^ 
and will be deposited in erysLiil8 n^ tht* solution n:>o!s. Or, 
to crystals of mercurouH uitnite sMld nitric acid, antl Imii until 
red fume?^ are no buiger evolved, lletarn the product for a 
8U^)8efjuent ex|wriinent, 

3% -f «HNO ^ 3Hg(N0,), + 2N0 + 4H/> 

Mercury Nitric acid Mercuric nitrate Nitric oxJilc Wii"lcr 

When mercury anil nitric acid are boiled together, nienniroua 
nitrate is ff*rniiMl if the luercnry be in excess, while mercuric 
nitrate ii* (jroduretl if the acid be in exee.«<M. 

Mffcurie (P.rt/nitrntrjt, — From the normal mercuric aitmte 
i*everal iixynitratcs may l>e itbtiiined. Tbus^ on mendy evapora- 
tiaga -solution of mercuric nitrate, and eoiilinp, crystals having the 
foramhi H^H KS( );)^,2HJ> an* depcisiti*ii The* latter, by wa*h- 
iuff with cold water, yield a ffMnf pnlvernb^ut oxynitmto, 
Hg^jO^lNOjf^: uiixtHl with lard, tins has soaietinie** bivn Ui<**^ i\» 
an ointment. Ry |in»l»»nge<l trcntaicnt with water, the yelhm' 
oxynitnite eventaally yields aiercnric oxide. 

The official preT>arations of niercnrie nitrate are Litpior Ifydrwr' 
g^ Niimfiji and IhtftietUum Ntffimrrfyri yitraiU, 

Mercurous and Mercuric Sulphates, 

Experiment 5, — BoH two or three grains of mercury with n 
few drops of nmcenl rated sulphuric acid in a test-tulie or 
snuill <iish, lu a funie-eu platan I ; sulphur<:>us auhydride i* 




i 





213 



involved, and Diercyric iiiiljibiitts H^SO^, a white, iieavj, 
crvHtuiUne [Miwtler results. 



Sulphuric 
iicld 



Bul phfttc 



Sulpliurous 
niibyilridu 



2J\p 

Wiiter 



Between two and three ounces of merciirir Bulphate may 
W prepared from a thiid drarfiin of laercary ami a t\uul 
umiec of sulphuric add boiled together iu a snmU dmh. The 
operatiim w eimipU^ted auil any excess of acid removed by 
cautiously eva|Kiratin^ the mixture of nu'tal aud Ijijuid to 
tlryiiet^ m a fume-i*ujihuard (s^ulpliurii* arid va|K»rs Imn^ 
exeeswively irritating to the mut uouh membrane of tlie mitie 
and throat); dry crystalline mercuric Hulphate remains. If 
re4*idual particles of mercury are observed, the muss fnliouhl 
be inobteued with sulphuric acid and again efirefiilly heated. 

By-product*, — In chemical man u factories, i^ccondary products, 
«ueh lis the sulphanius anhydride of the above reliction, are 
termed by-produrh^ and, if of value, iirti utilixtnl, In the present 

€e the j^iw 1!^ of no imnicdiale nse, aad iji therefore allowed to 
ape. When very pure snl[>hiirous anhyrlriih* i.s rerjiiircd for 
exi>friments on the nmall nalc, thi« wntdd W the bei^t niotlnwl *(f 
making it, a rlelivery*tnbc bt'in^ adaptnl hy nu/ans of a cork to 
the inouth of a flask cuatainin^ the ncid and metal. 

Mercuric Ost/mfphfifr, — Water deeonipoHep« mercuric suljdiate 
into a siilulde acid salt and an inwjUdile yellow oxysttJjdiate, 
Kk^O^SO^. The latter i» called Ttftyefh mhitnif^ inmi its rescni- 
hhmee in t*idor Ut vr'f/rftrfilt' turptth^ tin* ptiwdiTfd r<»ot of /jtrmittrt. 
(firj/f'ffmm, an Inrtian wulistitutt" for jalap. 

Experiment 6. — Huh a j>ortion of the dry men/urac sidplmte 
of I he preeeiiin^' ex[)eriment with as nuich merctiry ns it 
already contains; the jtrf>dni t, wlicn the tuo have completely 
cHunbined, m mercurou;^ Htdpbatts Il^'.SO^: it may be retained 
for a subst^qnent ex|>erimciit. The exact pro|Ku*tii»n of 
mercury to niercurie rndphnte is merely a matter of calcula- 
tion barted U|)fai the eqniitiou re|)resentin;f the chemical ebunge 
which take» place. 



Mercurous and Merciuic Chloride 3« 

Experiment 7. — Mix ihorouj^rhly a ft-w ^^rains of dry mer- 
enrir sulphate with about four-tit\hs of iLs wcigld of .^odinm 
chloride, utid heat Ihr mixlurt*, hIow1v» in a test-tula* in u 





THE METALLIC MADICALS. 



Fig. 36. 



214 



funie^upboiirfl ; niereync chloride, Hg€*lj, or corrosive subli- 
iiiat<?T Inch I omit* or pt*rrhlori<Ie of nwrtniry { Hydrartfifri 
Chloridum ('nrnmvttm, {]. S, P. ), suhlime* and <:i>iiden8e4* in 
the upjjer [mrt of the tube in heavy coiorlet* ervfitab. 

Soniewhiit larger qiiarilitieg (in the projxjrtioii of 20 of 
luerrurio suljiliate to 15 of* mxliuni chhjride and, mde iitfra, 1 
of bhiek nnigne-He oxide) may be sublimed in t\ \m\T af two- 
oiinee or three-ouuee rouiid-lM>ttimied ^fillijHHs, the one 
iuverteil over the other* uxid the joint hjted l>y mean^ of 
fni»iwt hreebiy (the jMjwdered duy kneuded with water Uk tb«! 
winnijitenee of dough ), Tiie 1 u ti iig 
liaving i>een allowed to dry (some- 
wliat nlowly to avoid enieks ), the 
pob* are placed upright on a mud- 
bath, siiud pib'd round the lower 
and a jjortiou of tiie up]>er pot^ 
and the whole heated over the 
ttauie of a good Buiis^en burner for 
an hour or more in a fumtML'upboanl 
{M'e Fig* *M\ — in which the pwib* are 
re[ireseuted as raised iu order to 
show the joint ). Mer**uric iodide, 
and caloinel, may 1)e sublimed in 
the same way. The temtierature 
reijuired for the former is some- 




HgSO, 


+ 


2NaCl -- 


-• HkCI, 


Mt^rcurtc 




SiHliiim 


M<.'rLiirif 


nilpbaiu 




chkifidt' 


chloride 



SubUmalioa. 

what lower than that for corrmive mdilimate while that for 
the bitter m higher. 

BUlptllllC 

yaie, — ^If the mereuric sulphate cod tains any iiiercurou« sul- 
phate, MoHie calomel may he fornied. Thin rewult will he avoided 
if *2 or 3 jK^rcent, of black manganese oxide J>e previously mixed 
with the ingrerlientii. The at tion of this oxidt^ ii* to turn out from 
the excesw of s^iHliiim chlorirle used iu the procei*^ the chlorine 
nere«Kar\' to convert any Cidoinel into tMjrrf»?*ivc suhliniate, sofliuni 
manganate aufl a lower niaiiirnneHe oxide being ^iniuhauei>ib*ly 
pp^luced. 

Prreviitdou. — The operation mm«t l)t' conduetetl w*ith care in a 
fume*cuplK>ard, because the vapor of corronive (Hulilinuite, which 
might pi>!<8il)Iy e^tcape, is very acrid autl highly poisononi*» Mereuric 
chloride volatilizes, though extreauly sh>wly and slightly, at the 
ordinar)^ tempn^rature of wano weiither. 

Unless preserved in an amber-colored bottle, a yery dilute 




ft 



Hg,SO. 


-f 


2NaCl = 


= :^HgCl 


Mcrc'uroiii* 




Bodium 


Mt^reuroua 


luliihule 




utiloridc 


clilorhk- 



MERCUMY. 



uqutMjussultitifja of mercuric uhkiride, when long kept, is liabli' to 
tl.*compji^itiotij <:aloiuel innii^r prt'cipiUitLHl, water decomposed, 
hy*ln>rtiloric acid taruied^ aud oxygen evolved. 

Experiment S.^Mix a few grains of the mercurous sulphate 
fntm ex|>erinieut G wilh alioijt a third of iti* weight of sodium 
chloride, aod Mihlijne in a tei^t-tuhe ; eryi^talline mercurous 
chloride-, HgCI, or ealoniel iHyilranjijrl Cklorldnm Miie^ 
U* 8, P.i re8ult8. I^firger qyjintities niuy be prepared in the 
miiti ne r d i reeled ff ^r cor rosi v e ho hi i rn a te^ a so i ii e w h a t h i g he r 
temperature being employed: mmilar preeautioiitimustaliio be 
oli«erved. 

Calomel may als<» lie made by other methodss. The nunie cahrnt'l 
{)ka/Mi jta/oif, gocjd, smd /i//af^ itwhu^ black) wu.h |irobab1y indiia- 
tjve of the esteem in which bhiek mercuric isalphidc (the compound 
Ui which the name calomel Wivs first iijiidied) \vm liehl. 

TtJfi /or vorrmive mthUmate in eahmef,^li the mercurouK sill* 
phate employed in this experiment ciuitiiin merciine «ulf>hate, 
Horne mercuric chloride will a Inn l>e formed. Oi-»rniHive sublimate 
in MjJuble in watt^r, eidtjuiel insrduble ; the pret^ence of the forjaer 
may therefore be jmiveil by lM>iHiig a ft'w grains of the calomel la 
d inti] I ed wal < * r, fi I le r i n g and test i i ig by ri i tm ii a ( >f hy d roge 1 1 s u I j i h i d e 
or ammonium hytlrosulphide ns^ descrilwHl hrreaiV^r. Tk two or 
thn-c grains of the sur<|>ected ealoiiiL'l may be mixed with a dn»p 
of 10 percent, alcohidie Ht>ap solmion umJ a drop of freshly pre- 
paretl alcoholic wihition *jf guaiucuia rcsia, anil the mixture well 
stirred with 2 Oc, of ether. On evaporating the ethereal dilution, 
the presence of mercuric chloride is indicated hy an intent? green 
coloration. If corro^^ive !*uhhinate be prei^*al, the whole liulk uf 
vihe calomel muj^t Ix' wash t^l with ht^t di^tilletl water till the filtrate 
eesise» to give any indicatitm.s of the im|>nrity, Cornjsive j^uhli- 
mate U more soluble in alcohol, and still more in ether, than it i^ 
ill water, while calomel is insiduhle in all three. Ether in which 
ejih>mel huA been digested sliould therefore, after filtratiou, yield 
no rewidnc oti evaporati<m. CuIoiikM is converted by hydrocyunic 
acid iutci niereuric cyanide and a black powtlcr rejulily yielding 
roetiillic mercury, l*owell and Hayne have .shitvvn that a certsiin 
proportion id' hydrochloric acid arrest^s this acticoL 

AVr, — Carefully [»urilie<l cotton, bleached hy dilute hleaching- 
jtowder sidutitin and thumughly washed, bikes up mercury from 
liilule wilutinn^ of mertnric rhloride, leaving the solution rebi- 
tively richer in ehhirine; fiurt of the mercury so tjiken up exists aa 
aiiehang(?d merenric chloride, |»art ns mercnrous chloride, and 
irt iLH niert*urie oxide. Hence, s(*lutions of mercuric chloride 
liradil not be filtered through cott<ai wool 



216 



THE METALLIC RADICALS, 




Mercuric Oxide. 

Experiment 9, — ^Eva]K>nite lx» JryiH'ti.s in a stnall dbt iu a 
futiitM/ii|>hoar«l, the mercuriL' iiilnite i'nuu exjHsrimetit W timi 
l»eat tht^ residue till un inure uitruun fume;* are evolvetl ; re4 
rtierturiL' oxide, ligt), red precipitate { Hydrarfftfn Oxidum 
Uni/runif LL vS. F,J reiiiaiu;?. 

2Hg(NOJ^ = 2HgO -f 4N()^ ^ O. 

M L re LJ r k; ultra U) Mercuric oxide Nitroj^oii iM^nKXide Oxygi'U 

A much larger yield of njercuric oxidi* (t'ur the siiuie quiiulity 
of aitrie acid used to diswilve mercury ) aiay be (ibtidiied by heating 
uiereanais nitrate, or by thr>rougLly inixiu^ with the dry iriercaric 
nitrate fnau exiKrinient 4 (prior in heiiting it) asunioh niereury as 
it already eont:tins (aj*eerUined by lalenlatitin fnnn the atimiie 
weights and the weight of mercuric nitrate em[iJoycd, n»in makiug 
uiereuruus sulphate). In this ease the free mercury 'm ali-o eon- 
verted iuto uiereurie oxide. 






Miiri^ury 



= 2Hk<> I UNO. 
Mercuric oxiiie Nlln>gvn peniXld»1 



Mercuric oxide in tested for nitrate by heatinjf ii litlle of t!ic 
winiide ill a tcKt-tuhe, when orange aitrou* vaporn are prinluced 
and are viHihle in the upjjcr part of the tube, if aitnite be prejMut* 

Mf't'etitic o.ritif in jui orange- red or red ]Hwder, more «»^le<HcrVr*- 
talline necordinjf to the extent Ut which it may have been stirred 
iluriu^ preparation from the nitrate. fhtijitrufum flffdranjifri 
O.riffi Ruhi, is official. Jlercurie oxide, in <oritaet with oxiiliwdile 
orjfanic matter, is liable to rtnluctinn to bhick or mcrcur<ai> oxide. 

The earliest mode ofprcparinjir mcrenrie oxide e<insisted in iiiairi- 
tuiaiii^ mercury at a teinperatiire near its boilin^r- point for many 
ilays in vessids, nearly clostHl to the »ir, in which a Ijirge surfnee 
otthe aietal was expos<xl. A red powder, which w as called //rrt*i/'i - 
tatum /tt^r a*\ wa^* g^nidually formed. It was Troai inereurie oxide 
H<» [irp[»iired that Priestly first obtained oxyi^en. 

Expenment 10. — To solution of [Hjtassiym orRodiiim byiirox- 
ide, or to lime-water, iu a le^t-tuW or a larger veesel, add solu- 
tion of corroj^ive suldimate^ mere uric nitrate, or almost any 
other mereuric salt (but not nierriirie eyaDide); yellow mer- 
curic oxide, HgO [Hydrargijn fKridttm Flnvnm, U. 8. P.) 18 
precipitated. 

HgCl -h Ch(OH), = Hg{> + OaCI, 4 H,0 
Mercuric nnletuiii Mercuric rjUrlum Wnn^r 

chloride hydruxidc oilile chloride 

The precipitate only differs physical !y from red mercuric oxide ; 
tlie yellow oxide ia aiore minutely divided than re<l. Utt^enhim 

Jlifdrattjijti Oridi Fffivt, ih official. 




-«; -*l 



Cii(OH), 


= Hk^(> 


4- CaCl, 


e'iil*'iiim 


MeniirnUK 


r^at'ium 


liydroxldL' 


<i\ide 


chloridt? 



i 



211 



Experiineiit 11, — To eiiloniel add solution of |iotftssiwiii ur 
sixliuiii hyilroxirle* or linie-wiitiT ; Uliu-k tuerrymus Dxide,, 
llg^O, is [irmluced, and may be tiltertul off, wjkshed aud dried. 

no 

Wakr 

This reaction tuid l\w formatiun of n white ciiniy precipi- 
tate on the addition of i^olutiim ti!" f^iiver nilnite to ihe filtrate 
from lluf niereyrotis oxide, add i dated by nitric ucid, form 
surticietit evidence that a jiowder eonmsts of or contain.^ calo- 
mel. The enrdy |yredpitate m nilver chloride. 

Analytical ReuvtiouH of Men'tinj (MmponnflH. 

The Copper Test (far Mercurous or Mercuric Salts ).^ — Place 
a p^iniiH j)iece of a bri^^ht i'opj>er, ulHint half an inch lon^ and 
a *:juarter of an inch broad, in a solution i>f any salt of rncr- 
curjt mereuroiiH or tuercurie* and heat in a lc.'*t4nlR\ the eo|»- 
per l)eeorne.s coated with mercyry, in a tine state of division. 
(The alim*uC5t* of any notable r|naiitity of nitric acid, njnnt he 
ensured, or the wbole of the cop]>er will Ih? ilisjwih^ed. INnir 
away the >^U|>erinitant liquid fnmi the ci>p[»er, wash the latter 
in the tnlve once nr twice with water, remove the metal, dry it 
by gentle pri^ssure in a piece of tiiter-]>a|>er, [dace it in a ilry, 
narrtjw icst-tnlrt*, and heat it to redtiesus in a Bun.sen Ihnnc. the 
tul>e beinfjf ladd in an abnost liorizontjd [Mit^ition ; the mcnnry 
volatilises and condenses a.^* a wliitisli sublimate of minnte j^IoIj- 
ules on the tM Mil part of the tube. The ^dolndes a^^ji^rcpUe on 
beitif^ gently prensetl with a i^laas rod, an<l arc cs|>ecially visible 
where flattene<l between the nu] and the iside of the tesL-tu!>e, 

,\W<ji fm fhr (cAt. — This \» a valuble twt for seviTal reasons: — 
It y very delieate when |K'rroraied with care* It st^pc'*****'^ from 
the suhstaiieeuader exam i nation, mtrcary itself, an demt'iit which, 
frtim hn metallic lustre and tlnidtty, cannot he aiistakcii for any 
otbrr. it iM :ip[>lit'Hble to both mercurous and mercuric ^alta. 
It readers pfwwihje the detectioa t*i' mcreury ni the presence of mtxHt 
other »iil>stiince*<^ ori^anic iir iratriranie. 

In performing thet4>st, tla' prcs^enceof any coriinidcrahle (juantity 
of nitric acid amy he avoided I>y adding an alkali natil a sli^dit f>cr- 
Jtinnent pr«'ripitati' appears, and then very sligbtly rcaiidifyin^ 
with a drop or two of acetic acid ; or by concentrating in an 
eviipitratin^-diHh aflcr adding a little sulphuric acid and then 
reililuliug. 




M 




218 THE METALLIC RADICALS. 

Analytical RmciUms of Mercuric Salts, 

1. To a lew finals of a dilution of a njennirie salt (cornioive ^ 
siihliryiitcs for example j mid solution of ^H)Ul^silulu iodiik% drop ^H 
liy drop; a yellowisli-rt^d precipitate of niercunL' imJitle, llgl,, ^M 
foriiis, and at first redistill ves, but is pennanciu when i^iitii- 
dent |x»tjissiuru io(Jidii bus bef u a<i<le<b Cxjutiuur the addition 
of jKitii5!*iijni iodide; the precipitate is redissolved. (See 
notes on p. 211. J 

Ammoniated Mercury. 

2. Add a solution of a niereurie m\t to ammonia wat^fT 
taking eiire that the mixtnns after well stirring, still Miiells 
of ammonia ; a white precipitate i.s produced. 

iVrformed in a tesit-tube, tJils reaetioa U a very delicate test for 
the presence ot' a mercuric saltj performed in larger vejssels, tlie 
mercuric syilt being cnrrot*ive snljliniatej it is the process for the 
pri*j>!i ration of white prt'npiinft\ formerly called lutiaifiniochoride 
nf mercury^ now knuwn iis Ammoniateti MerLurj* {Hijdraryyrum 
Ammoniatura^ U, S. P.). 

HgCl^ + 2XH3 = NH.Hga 4- NIT^n 

Mertync Amiuouiii White Aiiunuijiniu 

chloriik^ prccipiUtc ebloridu 

This precipitate \» eonsidereJ to be mereuri-ammonium chloride, 
NR^HgCl, — that i^, amnifunuin chlf»ride, NH/1, in which two 
atoms of hy<ln>gea arc ref>Iaccd by one atoiii of mi^rcury. When 
warmed with potawsinm hyiirnxide it eviilvcs :unmouia, 

Vnrietirni of Ammotiidft'd Memtrfi, — If Ibc onb-r of mixing the 
solutions in reaetmn 2 he rever^^ed, and ammoniji 1h' added to ^jIu* 
tioa of mercuric chloride, a ibiublc mtTiitri-ainmornniii and mer- 
curic chloride, NlTJlgCi. IlgCl,, is pro^hioiHl: it eontahis 7<>.57 
jHTcetit. of aiiTrnry. V diadde uiereuri-amnioiiium and ainnio- 
iiium rbloridc, NH^HgCl^NIIpI, conttiininir 65.57 |K*rcent. of 
mercury made by additig caustic potiinh or caustic >*oda to » t«*lu- 
tion of equal parta of corrosive sublimate and sal-ammoniac, is 
known as *[fimb/€ white precipitate," IxH^anse at a temperature 
somewhat below redness it fuses aad then volatilizes. The ofl^eial 
white preeipitate c<»atains thenretirally, 7fK 52 percent. <»f mereur}*. 
An ointment prepare<l with this iMjmf>ound is ritficijil ( Unfjumtum 
Hydranfi/ri Ammoninfi, l^ S. P.). Prob*jii;rd washing with water 
converts whik^ prt'cipitate iatn a yelbiwjsh eonj|)ound (NH^Hgl'l, 
HgO); hence thi/ otficial prff»aratioa is not thoroughly fret^J fmm 
Ibe aniaioriinm chbiride which is formed during' iti^ n*ajui facta n*, 
hut which, if present in hirger pn»portioii iban 7 m H jn^reent., 
gives to it the character of partial or complete fiLsibility, The 



MERCURY. 



219 



olfii!ially reoognued aumioniatod jiitTcurj should volatilize' at ;i 
teuipfniture btilow rt'diK'ss without i'uwiug, and ?^liould yield 7S to 
79 perceut. of iiietiiHic mtrcurv. With imjitir, cliloririe, or 
bromine, whitt? j>rt'ciiiitiite iiiuy yiflJ the dtuigenntHly exidtwive 
iiitrogeu i(j<iide, tdih>ridi% or bromidt'. 

DimLTturi-amiiiojiium itjdidf, NUg^I, ih formed in testing for 
immonia by meun« of Neiwk'r'ii re^igrnt (vvliieh noe). 

3. Paffl hydrogen sulphidt? through u oiurcurit; solutiuu 
unul I be liiiuid »nidl8 strtiiigly *d' the gjus; a black preiripi- 
|te ul* mercuric sulphide, HgS, is produced. 



HgCl, 


r H,H 


= 2UCI 4 


HrS 


Mv'fcuric 


Hvdrogt^O 


Hydnrchloric 


Mt^R'uric 


vhlarlde 


fiulphide 


iH4d 


Bulpiadi? 



I 



Mercuric sulphiiie does not dis.s:dve iu dilute aeitlrs or in 
ammonium hydr^ksulplude^ In the case of mt^curic chloride 
(or of othern)c*rcuric ^k to which hydrochl<nic acitl hits beeo 
ttil*k'd previonsly K hydrogeti tJulphidt, when tidded in i^nmll 
quantity^ produces a white i>recipilute. On the uddition of 
oiore of the reagent, the color of the j)re<'i|jitate changes 
tlirough various shades of yellow, orange, and brown, to Idack. 
The Slime whit*^ md)?tnnce may als^* be obtained Ijy beating a 
imall quantity of black njercuric snl[dnde with sdutiim of 
ttiercuric chloride. Its com|M>sition h rejircM^nted by the 
formubu HgCl,, 2HgS, The yellow^ orange* and l>rowi) sul>- 
»Lttucet* are interineiiiate in composition between thb tntd njer- 
curic aulphid**, 

Sote, — Mydroj^en sulphide nlno yields a black }*re(ipit;itc with 
M^lutions of incrcuroUi* siiltj** Tn the cane of the>*c salts, ihr pn^- 
ripiijite coriHi.^t'K i»f ji mixture of nierturic sid|»hidi' iomI iiienury 
(titit of aiiTcartiiis xulphiile); hence this rctigent dot-i^ not distiii- 
gilit^b bt'twei-n nicrrurouH and inerrnric salt^*. Rut in the course 
cif ny^tenuitic analysirt, laeri'iinc yaltw are |>recipitalcd fruai their 

jltitloiif*, a« Bidpbide, iiftcr inenurftUH .sdtH hiivc hn-n n innvid 

I cUlrmde, 

ftffl Mei*rurir Stj/phitir. — Prolnaged tontiut with hydrngi'ij stil- 
jibide or a hyilnjsuljdiide, esjKvially il warm, couvertH the blark 
into 21 r»*d Hulpbide. Vrrmilion is inereurie sulphide prepared hy 
fiublimatioiL 

Ethiop'* Mhitrnl^ foiriuTly kruiwii an Ht/fh'(ir<ii/i Stt/phtirefunt 
ntm $Sutphurf^ is a mix In re of mercnrie sulphid*' and sulphur, 
obtained by fritnnttiujf tlic clcmcntj^ m n mortar till ^hihulesnf 
mercury are rir» hmger viHible. lia name it^ probably ii« allusicm 
to itA oulor. 




220 



Atml^ical Reai'Ui 




1, To a solution of a mercurous salt (the niercurous uitrate 
nhtaiiu'il in t'X|)tTiiiient % fur exiimple ) shM liy*irc>chlorir ucul 
or other s^iluble i hloritle ; a white |>redpilntc of menninjiis 
chloride, tuilooiel, Hj^Cl, is jmnlyced* 

2. To II solution of a oierourous will achl a tew dro|)8 of a 
very dilute sohitioo of juitassiiuu iodide; a yellow precipitjcite 
of itiereurouH iodidei Hgl, i^ produced. 



Hj<i\0, 


+ KI 


K^O, 


+ Hgl 


Mrn^uri.JUB 


Potjifi?i j mil 


Potassium 


M*Teiifi>u» 


uUmtu 


itHUiic 


njtmte 


kidide 



Uoh^.^ very dilute fttiiutiiui of jKitat^siuui iodide k employed, it 
(lifiirtdt t*i uhtiiiTi ii pure yeihuv [ireei|)itHte, a jyrreeninh mixture \ 
uiercuroUH iodide and aiereury Iwiug geueruHy foniiHl, owing to 
the ilec<Mopot*itiiiu i»r Hiiiiie yl' the foniu;r hy exeeas of pc>ta.s8tum 
iiKliiir ; a fiiUMiderahle exeesH couij>letely decouijMise^ the mer- 
eurouB iiKlidi% forming potit^Hium iiitTeiirie iodide ami mereury. 



2HgI 



KI 



Kllgl^ 4 Hg 



The potas.'*iuin uitTeurie imlide in wohdde ia water, and fonn? a 
nearly rolorless sohition, while the metallie ujcreury remains m a 
hhiek iM'n'i|>italf, 

H, To a niereurous salt, dissolved or unili*^*Kjve<l {e. g., 
caloiuel), add arnmouia water ; a hlaek mereuroiJ-aiumonium 
salt (r. J/., ehltiride, NII.jH;:/ 1), ik fonued. It t^eeuis prohalde 
that tlie HM'ullfd iia-rruroF-aniu ionium ^vlia^ are really mix- 
ture?* of the inereuri-auimoiiium eompjuinU (Htc p, 218) with 
metal lie mercury. 

Other Tf»h for Mercnrif CfmipmintU, 

Tlie eliminatirai i>f men;ury u\ the artual MtUe of niettil !iy 
the copper tent, coupled with the prmluel ioiMU" uon-proiluetinu of 
a white precijiitate on the addition of hydrochh»nc ueiil tu the 
ori^nntil 8olytion, itt u.sually i<iifKcieut evideuee 4»f the prt^iseiice 
of mercury and of its existeuee iis a mereurons or a mercuric 
sidt. But other tests may sHunetimes be a]ii>lie<l with advaii- 
ta^^e. Thus metallic men^ury is dejjosited on plaeing a drop 
of the sicdutiou tm a gidd coin aud touehiug the drop and 
the edge of thi* eoin j*in>uUaueously with a key : an electric 
current parities, under the?4e eireumstancei*, from the gtdd to 
the key« ami theace through ihe liijuid to the gohl^ de^xim- 
|xj6iug the salt, the mercury of which funus a white uietalHc 



MERCUR \\ 



221 



t^pot ou ihe gold. Thi*< is eiilled the (jaltaiiic(ed, ami is useful 
ffir c!inic4tl purposes,— Solution of i^taunous clilori*le, HiilM^, 
froru ihe reatluiessf w itli which it forms stauiik chloride,SiiC1^, 
gWe^t with nierfurit; soliiti^ins ii while prei'i pittite of uiereuroua 
chlorkJe, aud rapidly reiluees this riifreuroys chloride still 
further to a grayi^ih aiass of fiuely divided iiieri'iiry; thiB is 
the maffpie lent^ ]>rolmbly no-ealled tVorn the white luul ^niy 
appearatie^? of the [ireeipitate. The reaetiuu niny aUo lie 
obtaine*! fVoui even sueh instil iilde uiercury eonijKiuuds as 
white precipitate. — A coiitinnatory test for uiercuric aud 
mereurous gaits will he found iu the action of sHiliitiou of 
potassium, s< id iujii, or calcium hydroxide, {Set' pp. 21(3, 217.) 
— PotiUisium chrornate, K..('rO^, pves with mereiirous m\t», 
a rt'd |M_'reipitate of rnercurous ehromate, IIjj^AtO^. ^Mer- 
cury aiifl all its eonjpouud^ arc more or less cotuiilclely vola- 
tilised when heated in a dry tube, many of the latter heiug 
cleeoin|K)sseti an<i yie!diug trlobulen of iiietallie niereury, — 
All dry eompiuiidti of mt^rcury are decomp^stMl when heated 
ia a dry test-tube with dried sodium carbonate, niereury sub- 
liming and eoiidenj^iug iu vLsible frh>hules, or as a whitish 
dejHisit which yields globules when rubl>ed with a glas-^ rod. 

Auiidoit\ — Albumin give>i a white prenpitsite with .*jo1u- 
tions of inercurjc salts ; hence the im|x^^tauce uf administering 
white of egg, while waiting for a stonmeh-pump or wtouiach- 
siphon, in ease of poisoning by corrosive guldiuiate. 



QtrESTIONS AND EXERtLSES. 

Nanit? th© cliief ore of men-ury, and dcHorilw a j>n>a*fls fur tht* extmc- 
il<^n of till? metal.— GJVH tb*" |iri>p<'rties. of mercury- — In wtiat stsiU' d<ipa 

eruury exLst in " Umy E'rtwdrr ?— VVIiat nt\n*T i>r»'p!imH<ins itf mi nillu! 
awrc-tiry itself are emi>loyL'd \n njetliciiu' ?— St^ik* f.!m n-ltititsn uf the 
lll«iri'un>u« U» this niLTCurii' oiruprMnidH. -DiHtiii^fui**!! Iietwetii iin athty 
»n<} !tti fTw»oA;rioi.— 8tat<' tlir foriuiHii" uf tht- twn mrrcMiry i<Mliili'S,- tiidt-r 
w^i -tHt»re*i hii«k nn'iriirie i(Mlidt' ditlVrt'Tit i<d<'rft ?— Illu-^tnite the 

t!J> uf Miiltiplt' t^rij'ii'oriiniijt si,^ expluhied hv iho nli»iiiir th^'mry, 

eiui ^.-^ i r tiiat piir|H»*t' ttie afat<'d tnmiwp^itiim uC {\\v two uitn-ury 
toduli*«. — WriUi ditwii tli*^ fitnnuhf tif Miniir^MiH urid Mirruric Nitmt*« 
«tiid 8iilphatt?s»— Mow is Mt-rturic Siil|»h:ilL' iirLtmrt d ?— What \h \\i^ 
frirmiilii of ** Turpi' til Miut^n*l " V- IiN\srril»t' tbt* pnKjtNsseH neot^^'fiHry for 
tlir ooii version tif m**rf'iiry into ruloin<l and ("orrttsjvf Siiblniiiiti\ iming 
©qiiiitionv — Why is hbuk jiijiKHnoMe mxid** Hiimpntfif** ruixtHl %vith the 
olhrr iij);>'« dictitH in tin' pn'fuinitioii nf oorn^sivt' t^iihliimitt? — Uivp the 
rlinniriil utid phyMi^il pi»iiit,H iif dilfiTi-tict' l»ftwt'<3ii raloiiitd and rornxsive 
«iiblimAH% — How msiy culomid in corrosivi* .siibliniati^ ln' dt^tcefwl ? — 
Cklrtilnlt* hrtw iioMdi MiTcnrv will W rctiiiirfrl in tht«: miinnrarhtrn of on^ 
l«in c»f Oilomel. -In*, IT owt. HfjiHy,— Mi^itiuii th*^ r»lflici»4l |irr|winiliims 
of Ihm M<!rrury Chloride, — (live tht? foniitiht? and mode r>f iVinuiirioti 



J 



222 




THE METALLIC RADICALS, 



of tliL' Ked, Ydlnw, and Black Mercury Oxides, employing diai^r&ms. — 
Kxpluiii tilt? aetin>]i i>f the elilcf f^ctienil test ftKr MtTeury. — How are 
■niepfiirtiu.s and inert; uric sjiUiii Aiitilylit'ally dUtiogiijisliotl? — Ciive a proba- 
hle vit*w tif the cunstitiitimi of IlifdrfU'ffifmm AMm&uiatum, V. S. P., aud 
ail iH|uutiori showing h«vv it is m^idw. — StAte the licst temporury anttdoltt 
to puiMJuiug by mercury* 



LEAD: Pb, \umuc wei«:Jii, 205.35. 

Orrurrrm'f. — Tht' on^>^ of lead jiro imineruiis ; iuit the one from 
wbitdi the iiiftiil is rliiiHy tiblidiifd i« lead Hul[diidi% 1*KS» y<ilrtiti 
(Iruui )rt/j'/i7/, ijnlhu'^ triiinjiiility, (*t?rliiij tit from \i& HUpjNJt^ effect 
in alhiyini^ ptiin.) 

VrqHintthii. — The am is iimt maHU'il in ii curreiil of uir; much 
8ull>hLir 18 thus liurnt ott' jih sulfdiurrjiLs anbydritic', while ^mw of 
the met*il in ^diverted into oxide; a jiortinii of thi' Huljihirle \a at 
theHjime time tjxidi/^il to sulphate. Oxidation is then jitoppcHj aiid 
the t4'niperature raised, whereupon the oxidi* mid sulphate, inter- 
acting with undeeompostd sulphide, vitdd the metal and sulphur* 
oils anhydride: — 2PbOH-Pb8=3Pb4 SO,; and PUS0^4-PIj8^ 
2Pb-h:iyOs. 

t'xrjf. — The usen of lead for making pipen and lead i«bi»eting 
are well known. Alloyed with nonte ijir>«:'nieT it ii* u>*ed in niakitig 
fjrdiiiary j*/if'/; with tin it fonns Holder: with iinliiiiony and tin, 
tt/pf'fuetai: and in smaller qiiautilies it entei's inlti tiie eouipotsition 
of Briffiitniii tHrta/^ jitirfer, and other alloys. Lt*ad h >*** Bli^htlv 
altaeked hy many tlilute iieitU that ehemiejil vcaai*!!* and iuKtru- 
ment-< are sometimes made of it. Hot hydrfK'hlonc acid slowly 
converts it into lead chloride with evolution of liydrt»gen. Cold 
Hul|djurie aeiti in {>resenee of air only very sli|rhtly attacks it with 
fiirnintion rd" lead sulphate and water; hot eoiieentrated Hulphuric 
iicid attacks it nipidly with formation of leacl sulpluite «nd evolu- 
tion rtf stilphiirfiU!^ anhydride. Hot nitric aeirj converts it into 
h'ad nitrnle with evolution i>f nitric oxide. 

J'/tf hfid nalff used in jiharmacy and all other lead preparations 
are obtained, directly or indirectly, from the metal lUcdf. Heated 
to a hi>rh tfMtii»erature in a enrrent of air, ie«d combiner witb 
oxygen and form.H lead oxide, Ph< ), a yellow powder (/mwfifv>/), or» 
if fiiMe<l and MilidiHed, a britrliter, reddish-yellow, lieavy nunfw of 
li right sc*ale.s {P!umbi Oxifhtm, Vl S. P,), tenned lifhnrrff (fmm 
>ff^N7, Hthf^*^ a stone, and «j/*;'7***rf fit^fffiton^ ^lilver). It is from thii 
oxide that the chicl lead compounds are ohtained. hend uxide, 
by further healing in a current of air, at a temperature con s<iderjibly 
lie low that at whii'h it was prin bleed, yields rrd hnd or miniam^ 
Ph.jO^. The* latter oxicle is intermediate in rootposition betwi*en 
lend oxide, PbO, and lead (Peroxide, PbO,,; and, although it i» 
usually rep rewntiMl by the formula l*b^n^, it it* subjwl to wnne 
varintion in eonipotiition. Both litharge und red lead Are inudi 



i 



LEAD. 



223 



used by jraintf^n^, paper-stiiiners awl ^liiR-^-nmnufacturerB, While 
ittui iii; lead liydroxyearlinjuik', 2PblV^, Phji)H)jj it is made by 
exposing; lead, eaj<t in wpiraln ^ir litllt^ ^mtiiiffs. tf> tlie avtkm rd'air, 
acetic arid fiiraeft, and carbciiiir anhydride, the latter g^nierakd 
from decay iotj: veget^ible luatUr, nueh a.s f^pent t:Jii: lead nxyaeetato 
i»|f»\\ly liut continuously fiinii.'*, anrl is jii* eontiuuoUHly deeinn- 
|K*t*ed by the enrbonie anliydride, witb jircHluctioii of bydmxy- 
carbonatc, or dry white had. Lead hydro xvi-arhnn^te ij^ alwi 
hIjhi made by briupng earbonie an by d rifle and litharge together 
in a >»ohition of li*iid aeetate. Ground up with about 7 pereent. 
of lin«eedH>il, it forui!* the trhite hftfl uj^-d by {^inters and 
plamlienf. 

Letjd romjwumU ttre piiiMmum, jirodueini*: sjiturnine erilie, and 
even paralyi^i^. These effeets are t<Tmed ^intttrnine horn iin obi 
mime of lead, Sfifnm. The ahhenjists ealled leari Sjiturn, first, 
lieeausw* they lh^tu«£iit it the rdder^t of the seven then known nielith, 
aufl it iniirht therefore be ecmqtartHl to Saturn, who wau* rejj^arded 
»» the father rtf the gods; and, Heermdly, Ineause its power of 
dlMtiolvinf^ tether nu^taln recalled a peenliarity of Saturn, who wiis 
said to be in the habit of devouring his own ehildren. 

Lead Acetate* 

Bxpeiiment 1. — Place a few grain ^^ of kad oxide in a test- 
tulie, add almut au equal weight of water and two and a half 
tiinc*e its weight of aeetie acid, and boil ; the oxide diswdv€%s 
and forms a soUition of lend acetate, liiCCjHjO^).,. When 
cold» or on eva|Xjrulion if much water haw l»een used (the 
solution being kept faintly a<Md ), crystals of lead acetate 
(Ptumhl Aceitu, U.S. P* )/Pl»( < ;ii,0,),, 3H,(). are deposited 
l^arger cjuantitiee are obtaitied by the same method. 



PbO + 2HCHn^ 

htud <>xi«ic A cell c Ai i<i 



I'bf(;H/),), + H,o 

Ix'Pid arrtiitB Wivtcr 



The sail is termed Siujar of Lead, firom its sweet taste. 

Lead Subacetate or Ozyacetate. 

Expenment 2. — Boil lead aeetate with four tinier iti* weig!it 
of water and rather U'^^s than two-tbinb* of its weight of lead 
oxide; the filtereil lii|Uor i^ 8«dution of lead snbacetale. 
Liquor FlumU Sttbacttu(i», IL S. P., Goulard*s Extract. It 
j*boulil 4xintaiii 25 |)ereent. of leml Hulmcetate I*h^()((',H/>j),. 

A similar >«>idntion wa,«< uh*iI liy M- Ooulardt wdio drew attention 
to it bi 177<> and ealle<l it Ertmrfum Snitttni, A more dilute 
»olutir>n, 1 f»f Liqnnr \n *li nf dji^tilled watt^r, is also olHcial under 



d 



THE METALLIC RADICALS. 




224 



the Tisiiii*^ fit' IJifuot' i*himhi SfibtwdatU fHlufnv. The latt«;r is 
comnNHily known as (imthtrd irnter, (h-afum l^umhi iStibne^tatiMj 
a iiuidilicaliou of the original (tfrn/anr^ Ctralt-j is oHkial. 

Lead Nitrate* 

Experiment 3. — Dige^^t a few graina of i eil lead in dilute 
nitrite acid ; lend iiitrtite, P!i(N()/),, ij* ionned, and reinaiujj in 
fiolution, while lead [lenjxide, I*l*<\, remain^ litdiiinl us a 
dark browiiish-[jurjile (H>\vder, Lcati Nitraie may be made 
more clirertly liy dis8irlvii)g Jillmrge, PhO, iu nitric acid» 

Lend ni hate or iieebiteis ii^^^d in iirejjariii}< lend imiide. Fur 
this pur[H*>ie the mImivl* ndxture iiuiy be tiUend, ihe lead penixide 
wa.'sliLHl with hot water, the tillrutt^and wuishin^'s evaporuled todrj'- 
m S.S in remove exeesn iif nitric aeic!, the residual lead iiitratt^ redi»- 
y^ilved hy Iwrilin^^ with a saiall «|uantity of hi^t svater, iiiid thesolu- 
lioii net aside to erystalliKe; ctr a p<irti<Hi may at tiiu'e Ih^ ui*ed for 
th<* nextex|H'rirnent. Lead nitrate, Pfumhi Xifnu, U. S. P., fnrnis 
white eryst^ds derived fnnn ort-jdiedrji. 

Le4id pemxide, Pb< >^, when he^ittnl with enneentraleil hydro- 
eldorie aeid yieldn lead ehloride, l^hCl^, eldonne^ and water. 

PbO, I- ma = Phci, 4 CI, 4- 211 ^x 

Lead Iodide. 

Experiment 4. — To a nmUral sohitioti of lead nitrate add 
solution of jwUafwinni i*Kiide; a preripitate of lead ic.vdidt', Pbij 
{ Pfamhi ludiffam, V. S. P.), is |vnMluced. Ecjual weijfhb of 
the 8a I is may be iis<<l in making hirgt* quantities. 



4 






2KI = 



Phi t- 2KN0, 

lA^nd lumiiti PutiUiiiinm nitrate 



Meat the len^l it»dide with the Mip-rnatiint iMjiiid, and filter if 
ueee.^arv ; the will diw^dv*^, and neparaten ag^ain to golden 
erystalliae ??<uiles aw the solution emds. 

Ivead iodide is !*^dll^de in f^ohuiou of anmiooium chloride. 



Lead Oleate. 

Bxpenment 5. — Boil toj^ether in a eniall fKiretdain dUh a 
tew gniiiLs of a very finely [Kjwdered lead (jxide, with twice 
itH weight of oiive-<>il, and ali^fj two or three time** it? weight 
of water, well Jiitirnn^ the mixture, and from time Ut tina* 
replaeing water thai ha.s eva|^Kirated; the protluet is a w hite mass 
of lea^l nieate, Pli(r,JI„0,),, glycerin remaining in sidiuion. 




2CH,(C n„0), 

lil oieute (olive-oil or oleinc) 



I 



Glycciil 

+ 2aH (OH), 

Glycenl hydroxide (glycerin) 

ThiH action iK^twwti the lead oxide and olive-oil is slow, requiring 

!jt»Vi'riil h*mr>i f<ir its complrtiim. 

Lt'iul Pkfil€T (Emphiffrum Phimbt, IT. S. P.) L^utiHistr* uf iiracti- 
Jly (Hire lead oleiiU^ jirepared by the ijitenirtjoji of lead jiretiite 
\\ ^AuXauu of si mi ji (mjirli- fniiii cilive-oil). 
Modes (if fonuatidii id ililorhlr^ iSttfphidr^ Chromate^ Sulphatej 

}l*/firoAvtf\ and other lead compounds are ineidentally described in 

the lolhnviiig analydeal jmnigra|di-'*. 

Anahjticnl Reuciians of Lend SatU, 

1* To a iwdidiun «d' a lead salt (acetate, for example ) add 
hydnM'h!ori€ add; a white ]*re<'i|»it}ite of lead chloride^ PhCl^, 
i«ohtuined. Boil the fjreeipitate with :i rwidenite quantity of 
water ; it di.sH4dve5, liut is redefKi^ited in &«nuill aeieular crystals 
when the solution wiols. Filter the cold s?<dution, and pass 
hydrogen sulphide through it; the formation of a black pre- 
npitale of lead sulphide^ PbS, shows that the leatl chloride is 
ndulde to a flight extent in cold water. 

Notf, — The formation of a white preei pittite (soluble in hot 
wnter Jind blackened l»y hydmgi^n sulphide) on the addition of 
hydrochloric acid^ suflieiently diHtinffuishes lead »alta fr^mi tlifist? 
of other metjd»; but the rion-j^rodiiction of «uch a precipitate dcie« 
not pnivo tlie ahsi'iiee of a small quantity of lead since chloride is 
nlij^htly R)kihle in vvat«*r. 

2. ThrotjjErh a dilute solntion of n leail salt, acidulatefi with 
hy<!rochh»rie acid, jmss hydro;i:en sulphide; a black precipitate 
of leiid sulphide^ PUS, is produced. 

f.,enti in Water, — The foregoing is a very delicate te«t, Hhould 
k tmce of lead lie pre^'Ul m vvatiT ust^tl ft at drinking puriHiscs, it 
Bay be detected by means of hydrogen sulphide. On jiassing the 
ga» through a pint t if such (acidulated) water, a hreiwaish edlor is 
jinwluced. If the tint is srarrely percefitiblu, s*^t the lirjuid iiside 
for a day; the hydrogen sulphide will nndtvrgo oxidation and a 
thin layer of Mul(diur will be found ni the hott<aa of thi- ves^^el^ 
white if no lead sulphate be present in it^ hut more or les** brown 
if it contain lead sulphide. Hygienists regard one-tvvenlicih of a 
grain of le4id |»er gallon ,*« ihingcr<ins, while :* smaller quHntity may 
dtt hjirnu Water commonly used for drinking jmrposes should 
not contain a trace. 
15 



2-26 




THE METALLIC RADICALS. 



^. To a solution of a lend siik ndd ummoDiuin hydroi^ul- 
phule ; a bhick ]>rpii]»itate of lea*l sulphide, insoluble in 
excej^ ; ir^ produced. 

4. Ttj a jsudutitui of lead mk iidd solution of |Kitas*iuni 
chrorante, K^C'rO^, ; u yellow precii>itute of lead chromate, 
P1>C>(\ is iorme(U insoluble iu ililuie iieids and iiisolutiou of 
tiinmonium chloride. 

Chmfitfn, — Thi^ reaetion hii^s leehuii-id us well «« analj'tical 
interest. The preetpit^tle is the t ojimnm piinHeiit termed chrome 
ijeiioiv^ or lent on rkrume^ Roiled with sliiked liDie and water^ M 
p»rtii»ii nf tbf ehnnnium is reuicnecl, together with oxygen, anti 
iiiniiH ealeiuin ehrouuite, white lend ox ye h mm site, of a t»rifrbt 
orange-n'd rob ir [/'/iriimr f^iw/o/f) it*i alw> pnubieed. 2Pl>< 'li ^^ - 
Ca(0H)3 = (;aCrU, ] rhpuA}, i Up. 

5, To a solution of a lead salt add dilute sulpburie aeid, or 
a Htdution (d'a sulphide; a white preeipitate of ii lead sulj>bate, 
PbSO^, is prcKluecnb 

Lrmt mifjfhif*' is slitrbtly solut)le in eoneentrated aeidsj and in 
«*itutioas (»f sione potassium and j*o<bum salt.^; it is iusobible in 
aeetie Held. It is readily dis^Holved by s<ibjlion of aaiaioninai aee- 
tate, the reinulling lit|uid yielding tlie ordinary reaetiont* with 
f*r}|uble eliroiiiate*5 nnd ioilide?;. It also dissolves readily in s<jhition 
of annnoiiiuai tartrsite in i>rejj*'m'e of aaiinimia. 

In dilute h<nlntiiins the above reaetion xvith sulphuric acid ar a 
soluble sulphiite dr>e.s not take plaee innnediately; the preeipitate, 
however, in [inHluecd after a time; itn formal ioa may be basteueti 
by evaporating tlie mixture nearly to dryness and then diluting, nr 
by adding iu the mixture its lova volume nt aleobol. 

The white preeiidtate often uotieeil in the ves.s«'lsin whieb dilute 
eomiuereial sulfthnrie aeid is kept, is leail sulphate deriviKl from 
the leaden i baaiberM in whieh the aeid Ls made. Its M>lnldlity in 
eom t'utrateil and its iiiHobd>ility in dilute sulpharie aeid explains 
itHprtx'ipitation. 

Antidote*, — Froai the iosfilubility of lead sulphate in water, the 
best tifttiftotr, in a easi' of jvoisoning by the aeeliite or other solulile 
lead salt, is a soluble sulphate, sueh as Epsom salt, sc»djum 8ul- 
pbttte, or alum, vomiting also lieing induetNl, or ihe t^>niacb- 
pump, or Htiiuiaeb-Hipbon, a}>p>lied as quiekly iia jK»»«ible. 

Other LentH for fead will be fuund in the reaetiiinH \vith/)ofnji- 
mum iodide i jtee [h 22-i ); with tiikftll-metal ntrfmnat^H, widch 
produtN^ white hydroxyearlRHuite* 2Pli('<)^, Pb( OHj^Jtmduble 
in excess ; with tilkalirn, which yiebl n white (jreeipitate of leail 
hydroxide. Pb(OH)„K niore or less soluble iu ex^-et^, and 
with alkaii-mtial phonphatr^, arsenates, ferrncifaHid^^s, and 



4 
4 



I 
4 





BISMUTH. 

etjanidm, which form com|>rHni<ls !it<>Htly iriwvliihle, but of uo 
8|»edal tttuilytical uiU-redt. JiihoIuIiI** sjiIih of leml miiy he 
dij^i*olvetl hy solution of pota^^-sium hydroxide or sodium liy<Jrox- 
ide, NaOH. 

■ The melnl is (jreripitnted in a hciiutifully i'ryf<tiillitie state 
by introduriu^ iiK'talHc ziijc (and sortie other metub) into a 
^dution of a lead Miilt ; the ieoff -tree is thu» Ibnneii. — Solid 
lead iM>rTi|>ouiids are reduce*! when heat*^d by the ldo\vpi|ie- 
tiatue in a small rtivity in a pie<"e of ehareoal, a .sot\, nialleahle 
head of metal heiug prod need, imd a yellowish ring of lead 



QUESTIONS AND EXERCISES. 



Write down equations rpprtAiontiug tlio ^oiclting of ^Ifina, ^Mention 
mnue of the allo.VM i*f lead. — Haw in* lithargt? priHlufW 'f — (}ive the foriu- 
itlte of whit© lend and rt?fl ieiMl. — TK SiTihe tlw luuioiturturt' nf white hmd. 
— DmwHdia^miii KhfwhiR thi^ fonnatioii (if IaiuI AlcIjiUi. -l>ei*t'ribe the 
prvpAiiktJoii and cotiijHKsitioii ui' IJqimr Ptumbi Snhacfifith, C. S. P. — What 
is the Action r»f nitric arid nu nd kiwi litharge? and lend ? — Montifiii the 
rhief tf«t« for lead.— How \v<iuhl you sw^-^nh for Hol^lblt^ tomiKjiinda of 
Ifftt! ill a domi^tic wat*ir supjily ?— Wliat is the fompwisitiim of ehrtduo 
yelhiwiitid of chrome omiige? -Name the he**lautidotr in casi'S of poison- 
lUfC hy Ici^ salta, and cxplaiu ita mode of actinu. 



BISMUTH : Bi. Atomic weight, 206.9. 

Ooeurrrtu'r. ^^Wimnuih oreurs iji the nieUtlie s^tate in aalare. 

It is froe<l frroii adherent qtuirt/,, ete,, hy winiply hc*nting, when the 

met4i1 mclt^, run.^ off, juid i^ n>lleetei! in appnipriiite v**s.m'1!h. ft 

\n hU) met with in eombiniitnm with other elementn; jnos^t coni- 

rnonly, iw c>xide, Hi^^O^, in binmtith whrr : sometiniert, hj* f<ul|iliide^ 

jH,, in htjttnuffi ffittHi'*\ Itisnnith is iimyinh wliite in eolor. In 

j itf* geneml ehemiral n?lation.»^hi|is it \^ alhed to tht" elements of the 

Liintimoriy and ar>*enie |fr*iii[\ idthou^di in its aitalytieal behavior 

[it if« more closely rehit-ed to lead and copjier* 

Purifit*ft/hn. — Arsenic may l>e removed frtun melted UisnitUh 
[l>y f^tirring it with an iron rod, iron arsenide rising to the surfaee 
Luf tbr muHs: antimony by .stirrinj? in some bismuth oxi<lt", when 
I untimony oxide separates. Otber metals present in biHmulh, 
[eH|»eeially i-opjjer, are eonverted into ^ulJ^hidt^H, while hisiriuth is 
liiol affected, by fusinir the tTii<li* niHal with about five pereeat. of 
J l^iol^iKji u m oy»nid<\ and two pcrrr-nt. of .'^uljdnir, tlie whole bein^ 
Lwell stirred for u <|narter of loi Imnr with a rlay rod (stem of a 
[tf>hiccvi'|>i|>e). (hi pmiring off the luelal fnnn the iUix^ and 




228 



THE METALLIC RADICALS, 



meltiug and Mirring it with inve }»erceiit. of a njixture of potassium 
ami sfxlitmi ntrbonaUs, sulphyr tuid trai-cs of other impuritiei* are 
rt'nioved, and tju' met4il i» ribtaineil pure. — Tnmm. 

rVirt. — Beyf^iid the eiiiployiiK^ut of n<nnv of its cojnjiDunrlM in 
medi*'ine, hismuth is l>uL little used. Melted hisoiuth expimds 
ci>a.sidentbly on solidifying, and henre is valuable in taking *!iinq» 
iui|»rt'ssion.s of dien. It ii* a constituent of some kinds of ty|M*- 
metal ajid of |iewter-ao!der 



Bismiitli Nitrate. 



Ezpemueiit 1, — To a few dropa oi' nitrie aeid and ao et\ 
quiuility of svat^tT, in a test-tube, add a small ipiantity (ii^ 
pt^wdered bitfunith, heating the ridxlyre if neeeasary; uitric 
uxifie, NO, eiseu|>e4i, and Hoiution of hisuiuth nitrate, Bi(NOjg^ 
results. 



Bi } 



4HN0 

Kit He acid 



= Bi(N(J), 4 NO 4- 
Bismiitb iiiCraUi Nllric oxide 



2H,0 

Water 



4 

I 



The solution, on evaporation, gives cryatals, Bi(NOA, 5H^0» 
any arsenic which the bismuth may have contained remaining m 
the niotluT-liqiion 

To make bismuth nitrate, nxvTiitrate, oxyellrho^at^? (or other 
salts) on a larger scale, 2 oui)ec*» of the nietjil, in small fragmenU, 
are gradually added to a mixture of 4 fluid ounce** of nitric acid 
and *A of water, and, when idfer^' essence (due to eseiipe of nitric 
oxide) has ce4i.HtHl, the mixture is heated for ten minutt^, ponred 
oft' from any insoluble matter, evajmrated to 2 llnid ounces to 
remove excess of acid, and then either net a^ide for crystal!* of 
liitmte to form, or poured into half a gallon of water to obtain 
bismuth oxynitrate, or into a solution of 6 iiui»ce*( (»f ammonium 
carbonate in a (|uart of wati^r to form oxyc arbonat<^, a.s dcs^'rilxHl 
in the followinir exptTiments, 

The iirt'eif>i!atcs should be wiished with cold water and dried 
at a teaiperature not exceeding ir*0^ F. {(^bJ)^ C). Exposed in 
the aioist ^tate tii 212° F, (100*= C) for any considerable time, 
they nndergfj ?^li|j;ht decomposition* 

Bismuth SiihmtTa.te or Oxynitrate. 

Experiment 2. — Pour son^e id' the above solution of higmuth 
nitnite into a cf>nsiderttble quantity of water; deoorn|Ki@ition 
oeeurst and a jireeipitate ( of mnnewhat varying chemical c^im- 
piHition f conBistinir of bismuth oxvnitrnle and hydroxynitrnlf 
is* (vfodueed ( lilivmtfthi Stthnifraj*, V, S, I'.). The formation 
of hiHuuith oxyuitrate is repreo^ented by the following 
ecjuatiou : — 



I 




BISMUTH, 



22y 



+ 



Bistuulh iiUmte 



H,0 

Wttt«?r 






2HK0 

Nllrtc acid 



I 



Filter, and te»t the filtrate for bismuth hy udding excess of 
sodium carbonate; the formiitiori of a prefipitati* «hows that wnuc 
bUmuth still retuain^ in solution. 

JJeeom posit ion of hisujuth nitrate hy water is the ordinary pro- 
cess for the preparation of hinmuth oxyiiitraLe for uav in medicine. 
For this purpose the original metal must eontain no artienie. In 
miumfactxinijg the eojnponnd, therefore, iMfore jMvuring the solu- 
tion of aitrate into water, the liquid shouki Lh^ tn^ted fur arsenic 
by one * if the hydrogen tests; if that ehaieal be i* resent, the eola- 
tion niUHt be evaporated^ and only the dejiosited eryntids lie u.sed 
iu the preparation of the oxynitrate. This must be done hee;iUf*t^ 
on pouriiig an arsenical solution of bisiimth nitrate into water, the 
ajsMfuie is not wholly reaioved iu the superaatiint liquid unless the 
oiynitrate he redissolved anil re precipitated several tiuieSi aecord- 
iftg to the aujimnt of afp^enie jiresent, 

BUmulh $tthnifrtitt' is gradually dec<jniposed by solutions of 
aJkali-meta) earl><inittL*8 (also hy the hicarhouate.% with produLtiou 
of cjirboiiic anhydride), bismuth oxyearbonate and the alkali* 
metal nitrate being foran^d. 

Btjrrnufh Oxijmlh, — On ficmring a solution of bismuth chhirhlej 
BiClj^ into water, hisauith oxyehloride, BiOOl, is ivroduced {a 
white jKiwderusiMl as a nwuietic, *' pearbwhit*.* " [Binnc dr Pnk), 
ulsf) in enauiels and in scane varieties* of sealing-wax). Hismulii 
bromide, HiBr^, and loditie, Hil,, siimilarly treated, yield oxy- 
brouiide, HiOBr, and oxyiodide, Bit >I. The suhuitrat** is, there- 
fore, pn>l)ably an analogous e4un|ioiind, an oxynitrate, BinNO^. 
Bismuth i^ulphate, Bi^(SO^),, is also deeoiuposetl vvlieii |iliiee<l in 
water, giving bismuth oxysulphate, Bj,<)„S()^. 

It iifi diffieult to prf.>ve whether or not the wat^^r in hydrfrtis IrJM- 
mnth oxynitrate, BiONt),,II./>, is an integral purt *d tlie sidt. If 
il ia, the compound is probablv hisuinlh hydroxynitrate^ 



Biflmiith Oxide, 

Experiment 3. — Boil hiamutb subnitrate with Rdution of 

mdiuni hydroxide for a few minutes ; it in converted into 
yellowish bismutb oxide, Bi^^O,. 

2BiONO, + 2NaOH = Bip, + 2NaK0, + Up 

llliniuth i^odtum Bismuth 8iKllurii VVjiter 

oXfUllrAte hydmi^tde oxide nitrate 




.230 



THE METALLIC RADICALS, 



Bismnth Subcarbonate or Oxycarbonate. 

Experiment 4. — T<> ti Hululiuri i4" iMsmuth nit rate add scilu- 
tior* nf iiimutniiiiin nirlKnuite ; si vvhitt^ pret^ipitate of hydrous 
1)13*11111 th oxycarhomiter {BL^mHUtl iSt(l}(*(irbomt^t V, S. 1\ ), is 
j^rtniuffd, of Htunewbiit VMryiiiju'; t'oiiijxjsitiutj, but ttpproxi mating 
to the foiinulu, 



2Bi.o,c:o,, H.O. 



liJt^gniith 
nitnite 



*' AjULUMlliuiti 



AniTDijiilmn Bismuth Cnrbimir 
uitnite l>x3'(^a^tHJnlltu anliyilridc 



This ronipound nuiy be ro^iink'd tui simihir in cun?«titutioii tu 
tlu* oxvsiiltrt Ju,Ht dr^iiTibi'd whirb are coitinionly liKiktHl upfiri as 
sialtH(ji'a hyptJtbetical radical hiymufhiff (BiO). 

Biamuth Citrate. 

Experiment 5, — H*?at 4 parts of Bismuth Bulmitmte and 3 
parts of dtrir acid with lii parts t*f water nn a waterdmth, 
with frequent >4lJ^^iui,^ until a drop of the mixture yitdds a 
clear j«o!utiou with annnonia water* Then add 20t> jiaiii* of 
water. The prer-ipitate, atler thomutjih washing, an<l drywg 
at a gentle heat, is* Ifemuth Citrate, Bi<*^.H^<_L { Bmnuthi 
(*iha.^, r. S. P.). 

Experiment 6.— To bismuth eitrate, rubl>ei} lulo a sriiocjth 
pju^te with water, atid heated rm a waterdiatfi, add ammonia 
water yulil the Halt m djt«s<.»lved and llie licjuid i^ neutral or 
only faiiJlly, alkaline, and (ilter The H«ilntion, evjiiM^raled 
to a Hyrupy ron^sii^tanee and spread oxi |j^h*»s platei* yieldi* when 
dry, Bi.smuth and Annnonium Citrate, ( Blmiutki el Amnwmi 
V'iinis^ ir* 8. P. ) in t^ealeH, 



Bismuth Subsalicylate. 



Experiment 1, — To 

solution r)f sodium Hal 

m hm\ iey late, i\l\ ^, O H . C^OO, BiO 

U. H P.), b produeet]. 



a i4<dution of lui^mutb nitrate add a 
evlate ; a white precipitate of bi&mutb 



( Bit*m nthi Sii bmilif^iai. 



Bismutli BubgaHate. 

Experiment 8*— To a solution of H parts of crystallized his^ 

nmth nitrate in 20 ]iitrtfi of dilute ai-etie aeid ( 1 |mrt of 
glacial acetic acid to 2|- ptirt.«i greater ) add a solution of 1 
part of gallic acid iu 45 parti* of water; a hright yellow |>re- 




BISMUTH. 



231 



I 



cipiUite of bismuth suli^allate { Bmiudln SidHjallas, U. 8. P.)* 
is i*l>taiue*i, whirh b of sM>me\vhat variable chemical eomjiOiii- 
tioiK 

Atmlytmd ReadUius of Bisjnuth Sitltj*. 

1, Through a sdlutiim uf a hismiith salt (a sli^^htly adtl 
8<»Iutioii of iiitmte, Ibr example) pas.*? hy<lro^eii J4iilphi<le ; i\ 
black jireeipitute of bii^iimth .siilphiile, Bi.S^, is |>ni«hice<L 
Ailtl anuiiuriiji water (to iieiitnilize the aehl ) ami then aitmio- 
uium hjilrcKsulphicle; the jjrecipitate, imlike As.Sj, iim\ Sb^H^^, 
m insoluble. 

2, ( ^jnceiitrate almost miy acid solution of a bismuth salt 
aot] |Mjiir iritu uuieh water eootainjng some sodium or amme- 
aium chloride; a white |irm'ipitnte of [lismuth oxychloride 
retiult8. 

Thii* reaction is t'haraett*ristic of bi.Hamth Halts, Bbmuth oxy- 
<'hlr»rjde i« ei4[»eetally ioft<iIuble in water, aial Ls iiistiuji;uii<bed fnun 
siiitiaioriioUi* oxyrhluride !iy beiri^ insoluble in solution of tartarie 
•dd. 

3, To a sfdutioii of a bismuth salt add eaustie alkali ; a 
white preeiprtate of bismuth hydroxide, Bi(()H J^, is produced, 
inwjluble in exee^s antt becmniji;; yellowish oo inuliujf^. 

4, First prepare a re^igent as follows: — J dissolve I ^^rain of 
lend acetate in H ounces of hot water and add ottdrnpsof aeetii- 
acid; diHSfdve (iti ^^riiins of potassium iodide in I^ uimees (d' 
water: luix the solution ; on eoolin^^ lead iodide is deposited 
ill the eharaeteristie yellow crystalline plates or scale*?. Next, 
pliwe some of the reageut (4*ry?*tal8 include*!) in a test-tulie 
and heat gradually till solution takes place. Any !ii|uiilcon- 
tainiriff, or 8U[>posed to riiiitain. Iiismuth is then added* and 
the vshole alh»weil to cool. The Heparated scales will show a 
dislinet change iu color fnaa the original yellow to dark orange 
or crimson, jo'i-ordlng to the (pnuitity of bismuth (U'esent, 

Test for calcium phospliate in bismuth salts. — I>is<4idve ilje 
jKJwder in oitric acid add alumt twice itn weight of citric acid 
ami suftirienl unmiouia to give ilerided alkalinity ; then boil, 
keeping the mixture taint ly alkidine with ammoniii ; bismuth 
remains in sidution. and eidcium pliof-|»!nite is preeipitateib 

Tests for other impmties in bismuth or its salts, — Diss*dve 
in nitric aeiil ; conf"**nlrate «nd set usidr tor crystals of Idsmuth 
uitrate to sefMirali* ; [M>ur ort'lhe mot herd i(|Uor, winch will eoii- 
tmiti iioy impurities in a concentrated form. If thi^ mother- 



232 THE METALLIC RADICALS, 

li(|ticjr be evajxtrated with hydr(H*hlork* acid until all the 
nitric ami is diasi^uted, a little of the priMliK't nbimld yield iiu 
cvifleiH'e of ai^eiiii" •ill heiri^ tixaniiiied by Marfib*8 test ; n<J 
blue eoloratifni on adding water and exee^s of ammouia (eop 
l*er), and na [ireeij/itate oli filtering and gaturatiiig tbejunnio 
tiiac^l tiltrate with nitric aeid (>ilver); no white preeipitate 
vvitb dilute ^ul|>hiirie aeid (leiid); no red or black preeipitate 
svith sodium .sulphide (telluriuni or selenium); and do blue 
precipitate with pcjtasaium ferroeyanide (iron). 



CADMIUM : Cd. Atomic- Weight, 111,6. 



J 



In nn>Ht of itB choinieal rebitioiiH tiidnijuin rej^einblef* zinc. !a 
nature it oeeni-H chiefly an an occasional constituent ot the ore ot 
that nittal. Jo distilling zinc coalaining cadmium, the hitter, 
being tlu^ UK*re volaliJe, jjfLssesk over first. Iiiaiialytical oj^'rations 
cadmium, unlike zu\k\ comet* down among the nietab precipitated 
Uy hydrogen saljihide ; that \»^ its wulj chicle ia ins(^luhle in highly 
ditiite hydrorhlorie acid, while zinc sulphide it* soluble. It is a 
white malleable inetid which lM»ils at 11\^ C. Sp. gr. 8.6 at 

Beyoml tlie oeeaMioiial employment of Ibettulphide a^a pigment 
(Jfttffti- briflifint), ami <if i\w iti<liile anil bromide in photography, 
cadmium and itt* .sjdts arc but little used. 

Cadmitun Iodide. 

Erperiment.— Digejit togetbcr, in w fhit^k. metallie cadmium, 
warm water, and iudine, until the color of the iodine dii«np- 
peiirs ; H»lution of eiitlmium i<wrnb% (MI..* remains. (iliMteuilig 
^vlnte crystalline *tcales may be cd>taiiied on eva|Kjrating the 
NdutitJTL 

ThiM .«alt ifl employed witli other iinlides in io<1i2iog collo- 
dion for idiolographic use. It readily melts ; and it ie soluble 
iu water i>r alcubob the 4H>lutiou reddening litmus, 

Anulxjiical Reactions of Cadmium Salts, 

L Through a solution of a cadmium salt (CM I, or CdCI,) 
pass hydrogen sulphide; a yellow precipitate of eadndum i?uJ- 
pbiile, (V18, h produced, rej«eniltlinL' in a]>pearauee arBemms, 
arsenic, and stannic sultdiides. Add ammonium bydmeul- 
pbide ; the preci]alate. unlike the sul]ibide.« jnst mentionedt 
dot-st iu>t dis*k>lve. It ilissolves easily in hot dilute hydro<.*hloric 
or .Hulphurie acid. 





CsifliniuTii ami cuprit^ sulphides may he septirateJ by means uf 
Hiltitioti of jjotjis^siiiui cvuiiitlt^, in which cuprii; sulphide is soluble 
litui futiiuiuni i^ulpbidtf irLstibiblt*. 

2. To a sohition of n cadniiuiii stilt Uiid sulution of |MJt:i9- 
siura hydroxide ; a wbittt pri?d]>ittiLe of* radriiiiHu hydroxide, 
M C<l(OH)j, is produccMl, iustdublt^ in exi^ess of thtj preeipitiiot 

■ Zinc hydroxide, Zii(Oir).^, precipiUtod tinrlcr sijnibir drriim- 
sUmees, is f*i>lublt* in wjjutmti rtl"poUi8.simii hydnixidi^ the filtrate 
i'rtnn the caciiiiiuiii hytlroxide Fiiay therefore be tested for any zinL-, 
presientiwan irnj*urity, by itddiii^ liydrogf-ri ^ul^diide or ainaioniuiti 

IhydrixHulphide. Zine and eadiiiinni liydroxiden are soluble in 
excess of anMiioniii water. 
B^/otf fhe bhw-pipt Jfnm^^ on ihareoal, eadniium salts give a 
brown de(>oHit of cftdmiiim oxide, CdO. 

H How doe«bi«inuth ociitr in nsiture?— Wbiit U the quantivaleiii'c of Ijis- 
H iiiutb'f — Write i*(|Ufttion:i <lc?s«!rijjtive of i lie actum of nitric acid on biw- 
H iniitb, and WAt^r on biHinii tli ii i trate. — Ibi w loiiy urHetiic bt? escludi^d from 
" bismuth salts?— (tivt^ ati equatbij illuiitratiiiK the protruss fwr thf prcprtm- 
tioii of bismuth carbonate. — MtMit ion the tt'*ts furbisirmth, — !u what con- 
dition does nidmiuiu ot'ciur in imturi^ ;* — By vs'hnt process may mdniiiini 
i«xlide l>e prepared?— Men lion tbw rhiL-f tiki for ciidminnK— Distiok'ni^h 
i!admium sulpbide fri>m sulphides of simikr t'lilor. — How \h cadmium 
separftU'd from zinc ? , 



QUESTIONS AND KXEKCISES. 




SILVIIE : Ag. Atomic weight, 107.12. 

Oeet4rrence, — This element oeeurs in tnitnre in tbe metal Ik" state; 
lUid H\m eombined with siilpbnr ns ><ilver sulphide, A^^, aaao- 
ciated with nitiLdi lead s^ulpbidf, fi>rining artjenfifenmi* f^tfettn. 

Prrparftfion. ^Tbe b:"ad t>btained rroin ari^entiferoiiH galena ia 

melted nnd nbnvly eooled; eryBtals of nearly pure lead si*[>arate 

lin^t and are raked out frtmi the still fluid nukss, wbicb thus eon- 

i*i«U* of an aUoy richer in silver. The operation is repeated several 

[ timen until «n alloy very rich in silver is J!na!ly obtained; this is 

in II current «d' air, whereby tbe lead is oxidi/ed and 

aved MS 1 i t h a rg:i% w b i I e p u re si 1 ver ren i j li nn. t ) t be r » • res u nd e rg o 

f various preprtnitory trentinents Mccordin^ to tbeir nature, and are 

I then fthiiken with uierenry, whirb anisilpunates with and clissolves 

[the particleti of nietallic silver, the mercury being jsub»e<|uentljr 




THE METALLIC RADfCAlJL 



riMiHivcil from the amatgam by distillatifin. Si>il and uiineTalH con- 
ttiiiniig nii'Uillir silver are iilsi> treat^nl in tlilHway, An important 
iiiiproveiiient in tlit^ aiiialpiiiiatit^u [tnn m^xs, hy wliieh the juerrury 
more reiulily unitt^ with tlie silver, consists in the ad"iiti*m uf a 
,smiiil jirnportion of WMliiiiii to the mereury. ,l<ilver chloritle raay 
Ih" dissolved fnmi ore?^ by T*t>lution of soiiiiitii lhiii?;iil[>hale. 

Silver is not readily a ff in- ted liy the weak aeid r»r other fluids of 
fonil, though it is rapidly tarnishetl by 8ul[>hur tuid many Hulf>hur 
ftmii>ouiids. It dtH's not perceptibly attack hydroclilorie arid; it 
rtnlueeH stiiuevvhat dibjtcd idtric acitl to uitrie oxide, Xt J, silver 
nitrate A^NO,, bein^ formed; it also reduci>* hot sulphuric acid 
to HulphiinKis anhydride, H( >,^, silver sulphate, A|^.,S(>^, Indug 
forrued. This* latter salt in crystalline, and slightly m^luble in 
water. 



I 

4 



Impure Silver Nitrate. 

BxperimaEt 1. — Dissolve a silver com in nitric acid; uit 
oxiiie, X(l, irt evolved, and a sfdiUion of silver and eupric 
nitrates is ohtaiued- 

Si/rer (hinmjf. — Pure «ilver i.M too soft for use v^ i-^iin; it i» 
therefore hanlencd by alloying with copper. The ><ilver coinage 
of the Uniteil Stjitcs contains lU [lenent. nf cojiper. British sil- 
ver nniney contains 1J\, (ternuin 25, ami French It^ and 1 *>.**! per- 
cent. ofcopjMT — for the fincnesH of the Krcneh stantlarci silver i» 
n.*»OfHn the five- fninc piece, while an inferior alhty of (LK,H5 is 
used Ibr the coins of lower deiiominiitions. The one-franc piece, 
coTnjHised of the hitter alloy, is still nnide to wci^dit five ^rammcsi^ 
tlie vveijrht originally chosen li>r the franc as I lie unit of the mone- 
tary ^ah- when the fineness df the coin was yjKML It lijtM now 
Wcome a token, of which the nominal value exct^nJi* the intrinsic 
value. 

Silver OMoride. 

Experiment 2. — To the product obtained in the prt>cedin^ 
ex|HtrinH>nt, mid tlilule hydroch!4>ric aeid t)r a g<dution of a 
chloride; a white precipitate of silver (ddoride, A^Cl, ia pro- 
<lueed, cojijier still remain iutr in i^dution. (\dlect the precipi- 
tate on a filter and waslv it with water ; it is pure silver 
chlori<le. 



NotfH, — TliP eopper may idi^i be wpHratod by evaporating the 
mlution of the metals in nitric acid to dryness and jjently beating 
the residue^ when the eupric nitrate is dea*mpomHl, but tbe silver 



SILVER. 



235 



nitniU' it* iinartt*rtt"<l. Tlie hitter may l>t' dis.solved out fmiii tlu' 
n'*sitlual ciipr'u" <»xi(li* by means of Wiiti r. 

SilvLT fhloride iiiiiy ln^ <4>t;iiiit^d in iryjitiils by rvH|i(iratinii of 
iti* H>lutif>n ill aniiiiortia vvatt^r. 

Tilt* ii^etubit'!ss<if baluju^t'H stihs nf fsilvi'r in [ibtttu^raphy tk'fHiuls 
U[Hiit the fjiet tiiat thcsi* i'^imijmiujkIs uinb^rgo a darkeriiiiji an 
exjwMure lo light. AcLunlin^f to Btiker, this in due bi tbe ibruia- 
tion of uji oxy-eoin pound— ill tbf case of the chloride, A^^Cbi, 

Pure SDver. 

Experiment 3, — Place the silver chloride obtained in experi- 
ment 2 in a dish, wet it with dihite sulphuric acid, and lay 
n piei-e uf t^heet zhie on the mixture; njftnlHc i^ilver m 
precipitated and, aftt-r abtmt one <lay, wholly reriioved from 
eonibination. ( Vdleet the [iret'i|ntate on ii filter and wash with 
water; it in pure inetiillie mlver, an<l is retnlilv fumble luto a 
wn^^le buttoUp esjieeially if mixed with a little borax and 
nitre. 

Note. — Any fonniibrable f|uaiitJty of silver chloride may be 
retlueed to a lumpof t!u* metal by fusifin in a erueilde, with almut 
half it«; weight of S4)dimn ciirbniiate. Theehloride Is nUo reduced 
by boiling it witli nmstie alkali antl ^rn[tk' sugar until a trial 

mple is entirely fii«solv(Hl by nitric acid. 



Pure Silver Nitrate. 

ExperimeEt 4. — Dinsijlve the pure silver from experiment 
l^ in nitric acid ( -^ part>i by wei^jrht (d* nlver require alunit 2 
or 2i id' c«mcentnited acid diluted with Tj of water k aud 
rfinove t^xcess* of iicid by eva]><^ratiii;/ the stdution to dryness 
and *4li^ditly heatinjc the residue ; ihc product \^ pure silver 
nitrate. Diasdve it hy heating with a small quautily of 
water; the iwdutiou on cotding, or on evaiKinition, dep^sitB 
eolorle*4s tabular crystals of silver nitrate. 

HAg ^ 4fINO, = NO + HA^W), ? 2H,0 
eilyer NUricai'M NHHc oxide PJlver oitriite Water 

Not^,'^\her Nitrate {Argenti Nlfran, IT. pi. P.), treated with 
4 part?* of hvilrochhtrie Hci<l to rvcry KM), melted nt nn bvw a 
U^m|>eratare ha p<»ssjblc, and poured iut<> propter moulds, yields 
the white rylindrii al stieks i»r rods rouiaiorily termed rnuHth \\mx%\ 
*iii<^, kftio, I bum), iun4tr rmtufh^ or mtuilded silver uitrate 
{Artjmti NUras /Wi^^ U. 8* P.). The alchemiata calle*! silver 



236 




THE METALLIC RADICALS, 



Diana or Ltitui^ fmni itn su|>[M»«e<1 mystentjiisi connectioii with 
the mtK^n. MitiifiiWri Silver Nitriite, Anjrnii Nitftut ^ftii^f{ltuM^ 
U. 8. P., iri n fti»t*d niixturr <A' iiue jmrt of silver nitmte with 
two parU ipf iMjliLssiiini iiitriite. 

The w[ii*L'im(/Ti of silver nitrate r»hLamcMi in the foregt/uig ex peri* 
rneiit, dissoheil in wati^r, will he found u^^t■^lIl iis an amilyticjil 
retLgenL Silver nitmte dissolves in 1M> pereent. uleohol ; but 
titToni|J05*ition oeeurs ufter a time. 

Silver siilt.s lire deeomjiosed when in eontact with orgimk' matter, 
espeeially on expo.snre to light, or on heatin^j the meUil it'*i'lf 
l>eing liberiited, or a hljiek insoluble eoiiipouiid IbrnuMi Hence 
llie value of" silver nitrate in the nianut'aeture of intlelible ink for 
nuirking linen ; henee, too, the reiison oi' the praetiee of rendering 
Hilver s<tlati<niH eb ar by suhsidence and denmtjiliim, rtither than 
by liltration throut^ii jcijier; aial hejiee the eau^w.' of thotie caaea 
of aetUid onnbustitaj wbieh have been known to occur in jireparing 
pillrt containing nilver nxide und essential oil t»r other organic 
matter. Linen aujrked with silver nuirking-ink should not Iw? 
cleansed l>y aid of bicarb ing li«|uor^ as the marked parts are then 
apt to Ive ra[ddly oxidized and ''tendered/' h<des resnlting, 
I'aul wtys the reaction i?* iu* follows: — Ag^O + CaCljf), = 
2AgCn + CuO f O,. 



Silver Oxide. 

Experiment 5, — To a solution of eiK^er nitrate add solution 
of putiLssium or wiHjium hydroxide, or lime-water; an olive- 
lirown [)reci]jitate of silver oxide, Aj^J), i>* produced. The 
wai^bed ainJ dried oxide* Artjridl fkrifhim. U, S. P., i.s dee«iin- 
posed by the action of beat, with production of inetaK It ii' 
aUo redocwl by contiict with orgauie matter. (See preceding 
parugrapb.) 

In preparing it calcium hydroxide is the precipitimt usinilly 
eni[d«iyed, pot^iKsiuni or srKliuin byilroxide not In'ing «<i readily 
removed by wiLsbing. Three and a half pints of gCM>d lime-wati*r 
will decomfHise half an ounce of 4*ilver nitrate. 



JAgNO, 

silver 


f ca(t->jr), = 


- Ag.O 


f- 


(*a(NO,), 


4^ H,0 


Culclam 


aaver 




t'aicium 


Wilier 


nlinitv 


bydroKide 


oxtde 




littmt« 





Bilver oxide is also preeipitated on adding ammonia water to a 
a^dution of silver nitrate, but it is rapidly taken np by thf 
ammnrnani nitrate fonneil at the s;mie tia!«\ argent-naimonium 
nitrate, Ntl^AgN*),. probably being formed. The direct sohition 
of silver oxide in ammonia n»ay give the highly explotiive aub- 





Hlauce known us BerthoUet's Eliminating silver (? NH,Ag). 
OnVimiry fubninatiftfj »ihrr^ C^jN^O^Ag^, resultn from the inU'rHcti(*n 
of Hilvi^r iiitrate, uilric ucitl, and iikohol. The rnra'S|)on*liiJg 
mercury compound, J'uhmtujlhifj ftifrntinj, L\^^)Mg, is uh*'*1 iti 
percuiwion eapj*. Silver Ammonium Nitrate le.st-tSt»lutiun is 
olfieiaL 

Methods of forming several other salts of silver are incidentally 
mentioned in the following analytical paragraphs. 



I 



I 



AttahjUcal Reficiiofis of Stiver S(i(i^, 

To a solution of ii silver salt athl hy<lroehloric aeiii or 
other soluble chloriile ; a white curdy preeipitate of .sih*er 
chh>ri<le. AgCM, is jirodneed. Adtl nitric aci^l, and hoil ; the 
prtM-ipitatc tli>eH not disst»U'e. I'our oH' the acid m\d add 
amoiouia water; the precipitate diiiSfdve}*. Neutrali;cc the 
ainimmiacal s^dutum by mean^ of an acid ; the white curdy 
precipitate is reprodticed, 

Thi« is the most characteristic test for silver. The precipitated 
chloride is also B*)luhle in wolntiotirs of smlinm tliiosalphatf* or 
potafteium cyanide — facte of considurahk* importiince In photi>- 
graphic operations. 

Other atialtfiicai reafjenff^ he8ides the alcove are oerajaioiially 
ui^^fuL — Hyd roi^en sulphide, or animoniuin hydro^ulphide^ 
gives a hhick pre^'ipitate td" silver 8uli»bide, Al^.S, innidulile 
in alkalies^, — Rohrtion <d' jmlas^inin or .«^>diuni hydroxide ^ives 
a brown precipitate of silver t>xide, AgjO.— ^Sodium plio:i«phjite 
gives a yellow preiipilate of silver plnmphate, A^JT)^» w>lnble 
itl nitric add and in ntiinionia water. — ^Ariinifiiiinnr ait^enate 
give^ a brown preeij>itate of silver arsenate, A^'^AsO^, alreitrly 
noticed in connection with ar^nic acid. — Potassium broniide 
givee a yellowif»h-white preeipilate <d' nilver bromide, Ajf Br, 
insoluble in dilute acids, soluble with sHmw dittieulty in 
ammonia, ^ — ^Potasi^inm iodide |>roduc-eH n pale-yeilow prw'ipi- 
tate of silver ioibde, Agl, insrduble in dilute acids. It is 
ohangeil by ammonia int<> a yellowish ini*olnble compmnd. — 
Potiu^ium cyanide triven a white precif/itate of silver cyanide, 
A gC^N ( A rgeni i Cijn u id urn, V, S. P. ) , sc d t d >l e i n e x ceHS, 
mmiewhat soluble in amnjouiJi, iu^oluble in dilute uitrie acid, 
sohilde in iMnling eoucentraleii nitric acid.^ — I'otnssiuin t^hro- 
tniitev K^CK3,, gives a red pre^eipitate of silver chromate. 




238 



THE METALLIC RADICALS. 



Ag,j('rO^, — Potii^sium dk-hrojimie g-ivea a red precipitate of 
silver jxiiliydrnrhroviiate, Ag,^Cr.,( 1^. — ^Mmiy nrpuiic ar'uh ^ive 
rise to insoluhlt' iiilver salts. — Several metali^ cli^place mlver 
i'runi Bolutioii, mercury foriuiiig iu iliis way ii cryi4iaUiue 
preeipitate known tL^ the ^filver tree, or Arbor Dimta'. — ^ Heated 
ou ehure*>al witli fUMliuni earlKjnate in the hlowpijie-tlanje, 
silver salts yiihi hrijujht gltihules of silver, not aeeo[n]»anie«l 
Uy ail iiirriistatioii as in the ('orres|HHi<liiiir reaeti<*n with h-atl 
•salts; the experiment may he jM^rtbrnad with the nitrate, 
whieh tirst melt-s ami then, lilie all nitrates, ileilagrate^ yield- 
ing a white metallic coating of i?ilver which i^louly aggregates 
to a button, 

AnlidotfJ!. — Solution nt riMtirnon s^ilt, sjil'jiniiimaiai% or any other 
iaert fhlnride slmiihl fibvioaHly hi' sHlniini.steivd uiiert* hirge do^es 
of silver iiitnite have \wvn wwalluwed. A r|aaiitity itf sea-water or 
brine WfUild eoiiverl the >*ilver iato ioiWihihle ehloride, and at the 
naiiie time jUi-Kiuee vomiting. 



QUESTIONS AND EXERCISES. 



By what prciceBS is 
of U, S. 



stiver obtaiiK'd frt>m arfC<^ntifer()UB lead?— What 
weight of U, S. silver coitj will y'wUl am- imunt\ of pure silver nitrate?— 
How nuiy the Hictal W rcLUViTtHl frutii iiii|iure silvtr Halts?— (iivp a 
ftiiiicmai showing the fimmitkm of f^ilvor iiilrate. — DesiTibo the reaction 
of lime-watiir with nilvi-^r uitmte. — Mcaiion th<* ehitf te?^t fur fiilver, and 
state how Mlvcr salts mny Im? ili**tinKuisht'cl from tlioee of lejid and mer- 
cury. — Name the antidtit*^ for Hilvrr, 



Q na Htat i vt A n « lyah. 

^fethods for the t^aalitative arialvKis (dMilationw rontaininp any 
or all tif the metals, eoi^HT, mereury (lilhiT us nierraroie* or m 
nierenrie salt), tin (as stinniuus siUt), lejid, bi-^ninth. eadmium, and 
Mlver have now to be eonKidered. Before introdaiia^ thetttudent 
to the systematic exaaiination of solntinas eontainin^ any or all 
of the no"tals*if ^rnerul interej^t, treated of in this Mamml, it will 
be eonvenient to indicate how th<- partien!ar metals just aientiouH 
above, are dealt with in that systematie examimition, in mi far m 
divitlinir them iato imalyiind groups is (•roirerned. 

The tirst juaut to U' aotod is that silvrr and aiereurotii* chloridw 
are inwdnlde, aatl that lead i-bloride is only sparingly sidnhle, in 
eold waitivr. Aflditioa of exee^n r>f bydnH-hlorir aeid, or other 
soluble ehloride, to the solution, cjiuses the complete precipitHtton 




QVALITATIVE ANALYSIS. 



239 



N 



^ 

I 



of silver jin<i luertuirousi-hlorideff (or, if iiu pn^'i pita t^^ forms, show's 
the ab^'nce of tbone nieUillif radit'als), iirul it intiy cau^te the pre- 
dpitati»»n of some lead LliloriUe als**. After reihoviiig any jtre- 
dpitatd by bltnitioii, (jart or tbe wbole of the Ic^id (if any wsis 
|*resi'nt ^ingjiially)^ and the wh<de td'ariy of the utlier oietalt^ men- 
tioned ali*ive, vvbieh nmy liave In^en j>ri>ent, ]«jirtH into the tiltrale. 
from whieb they eaii Iw i(reei|)itatetj l*y meajin nf hydrogen sid- 
pbiile. 

Tiie fact that this inetb(nl mI' dividing thi's^e metals into two 
gnnipH fur aniilytieal pur|MHe.% is pnietieally nniversiilly empbiyed, 
ftirnii^hej*? the exphuiation fur tbe *?e|iarate treatment of the metal- 
lic radieals eoiiMitnting tlae two grou[*«, in the tvv*» pairn of pre- 
liminary analytifHl sibeme.s wbieh follow (jip. 2H9, 242) The 
first i»air of Hi/bemeji deal with silver, niertumuK, and lead saits; 
whih"^ the ^iectind pair deal with rn[>rie, mereurie, lend, bisiimth, 
and eafhnium sjilts, nnd (Kirtially with stannous sidts. 

The jjr^sjtion of tin in tfiis aindytiial iirrangeineut is Mjmewhat 
unomaluUK, sinee, in tbe runrsM? of tbe syst4?m«tie w>i>aration <»rthe 
tuetitls, this element Iklls into the aiialytieal grout* alung with 
iin«etiic and iintiintiny, Tbe eoiinertion of this hiti:er grouj) (the 
arsenic gruup) with the grou|) enibraeiii^ etjpper, bi.Hmutli, etc. 
(the copper group), will be evident later, when the scheme for 
the »y»tematie separation of the whole of the metalH of general 
interest comai to be diwcuftscd (p. 244). 



^1 DIBECTfONK FOR APPLYlNii HOME OK TttK RKACTIONS Dl-lS- 

^H CRIBED rX THE FORECJOINO PARAGRAPHS TO TilE 

^H AXALYSIH OF AN AQlTEOUg SOLITJON OF A ,HALT OF ONK 

^H OF THE METAL^S i^lLVKR» MERCURY (AS MERCUROITH 

^H eALT)» IJ An. 

P ' 

w> nin 



Add hydrixddorie acid : — 

Silver ij* imlieuted by n white curdy precipitate, insoluble 

ill exce>*>i, eiu^ily tHduIde in n(nim*min water, 
IMercunnLS .sjilts \a indicated by a white precipitate which 

\t^ til rued black by ammonia water. 
1/^fld 19 indicated by a white precipitate, inwdyble in 
anmioiiiii water. Coufirni by boilitig a ^^mall }>ortion 
of the hydrociiloric-acul pretipitute in water ; it dis- 
*olve#». 
If lmlnK*h!onc acid give^ no jjrecipitale, nilver aud tner- 
cnrouM laalt.-^ are absent, and lead can only he present in very 
itmiill (juantity^ The |irescnce of lead in snuill tpiantity m 
beet detet^ed hy apply io^ the sulphuric acid test to a fresh 





240 




THE METALLIC RADICALS. 



portion of the origiDal Bolution, the tul>e being set aside for a 
time if the precipitate does not appc'ar at oiu'e. ' 

TABLE OF HHOHT D1RKCTIOX8 Ff>R APrLYINC; SOME OF THE 
REACTIONS IJEH( RIBEDINTHE F(JRE(10IN(1 rARAORAPIffl 
TO THF ANALYSIS OF AN AQUEOUg SOLUTION OF ANY OR 
ALL n I " T M E M ET A L8 S I L V E B, M ERUU R Y (AS ME Rt U ROUS 
BALT), J,EAD. 

Add hydnx'hloride a^rid m excess, filter, aod wash the pre- 
cipitate with a iiiiall f|uaiitity of cold water. 



PrcH'i Imitate 

, PhH^fMllH} 

fc Wash on tbe Hlter with h 


A^ 

lilmg water. 


FiltntLe 
Pb 

Add 

wbite ppt' 




Beftidue 
Hg (oils) Ag 




F^tnte 
Pb 


1 


Add NA.on. 




Add 
wbitc ppL* 




Residue 
(mercuroii«), 


black 


Filtrate 
Ag 

Add UNOj while ppL 


1 



DIBECTIONS FOR APPLYING SOME OF THE REAlTIONS DE- 
SCRIBED IN THE FOREOOINO FAKAORAFHS TO THE 
ANALYfiLS OF AN AQUEOUB eOLUTION OF A SALT OF ONE 
OF THE MI-rrALa COPPER, MERCURY ( A8 MERCURIU8ALT), 
TIN (A8 STANNOUS SALT), LEAD, BI8MUTIL TADMIUM. 

Note that wlutions of cupric salts have tf blue color. 
Acidulate the liquid with hydrochloric acid and paai 

' Liipihl?^ contninin^ only » HmiUI t|ii»iititv <^f f^iid du not readily 
yitdd loud •«til|ih.it<* on the rkf]<1jti<>n of siitphtitir Arid, notiin' tcadcHn lie 
KHid to ht\ nhf^tiU fhprofon?, ihc Iii|uicl should br* ^vn|>onitcd to drypcis 
with otw flroji of itulphriric ncid, and tlie regidiit^ dt)?e«ted in water; any 
lead «ilphat<^ flitsn remains as a heavy, wbitet insoluble powder. 





QUALITATIVE ANALYSIS, 



241 



hydrogen sulpbide through it tintil the mixture, afW shaking, 
snielhs of the gas: — 

Cadmium m\ts give a yellow precipitate, iuBoluhle in 
ammuiiia water eafiily swluble in hot ililute hydm- 
ehh>ric acid. 

Cypric, mercuric, stannous, lead» ami bismuth salts give 
dark-ljrown or black precipitates. In the case nf a 
mercuric j^alt, tlie [jrecijiitate may be white *ir jKile-ye!* 
low at lii'st. imt it rapitlly In^comes orange, brown, and, 
finally, Ijluck. In tlic ciiHt^ <»t" si lefid 8alf, the [n*eci|>i- 
taCe \a sonielimt-s rrddish-brown it nmcli liydrocliU>ric 
acid is pre^sent, bnt it liefoiiies? blnck on dilution of the 
s*»lution anfl additimi of t^mmgh hydrogen 8nl[Jiide. 

To (listinguii^h cuprie» mercuric, stjinnons, lead, and bis^ 
muth iMklU fnmi one another, iidd jxitaKHium iodide to another 
portion of the original yo!ntion* — 

A pale-hrciwoish mixture (which really consists of a 
nearly colorlcfis [U'cd pitate of cujirouft iodide in a 
yellow or brown Bolution of iodine) indicates a cu])rie 
salt. The brown ttolor disappears and the preei[ntate 
la »een to l>e nearly colorless, when s<dntion oi' snl- 
phurousi acid is added {Van|iare reaction 7| p* ^^^^- 

A ye!lowi!*h-red preci[)itate. rapidly becoming bright-red, 
soluble in excess of potassium iodi<le, indicates a mer- 
ruric sail. 

The [jrodnetion of a pale-yellow precipitate, or, in dilute 
solutions, of ntnic at all, indicates a stantnnis sail. 

A yellow preci|ntate, insolulde in excess of |Kjtassinni 
iodide, stdnbk^ in Iwiiliiig water, iiidicalt-s ii lead i«ialt. 

A bright-yellow solution, or a browu precipitate which 
dissulves in excess of |xjtassium iodiileto torrn a bright- 
yelhnv solution, indicxites a bismuth salt. 



TABLE OF SHORT PIRECTIOKS FOR APPLY1^'« SOMR OF THE 
BEAC'TIONS DESCarBEO IN THE FOREOOINO PARAU&APHS TO 
THK ANALYSIS OF AN A<^lTEOlTH sOLtrflON OF SALTS OF TWO 
OR MORE OF THE METAI^S, COrPEK, MERCURY (A8 MERCtTRIC 
HALT), LEA I»p BlSMin'H, rADMlUM, 



Aeululftfe the liquid with bydroehhjric acid «nd pasn bydni- 
gen sulphide tlirmi^^'h it until the mixture, atler si la king 
stneila ai the gas ; HIter. 
16 



242 



THE METALLIC RADICALS. 



Wmh wkb walerj hoil with IlNOai diluti? with 
water iimJ iilter. 



Resuliit* 

Bbi-k 
t'oiitinn hy 

Vai teiit 
in iirif^iiiiil 

iiOllltloTI 



Filtmte 
Add NH^Oll in exces^ tiken 



Preci|>itfite 

n* ni 

WuhIi^ disecvlvf OH 

tiller in ti fi'W drops 

of dihit*i HN<J, 

dilute, filter. 



Filimte 
« 'ti Vd 
(BiuuifCu piTttent). 
' .\dd Kt'N in 

I t^XCk'^W, anil [UHrtii 



white 



Filtrate 


^^ 


Add 


yi-dlaw 1 


H^), 




mi mvdfi ; 


:{ 


whiie ppt 





Filtrate 

Cn 

Aeiilify 

with' 

tutHieaeid 

brawn 



Filtrate 

Dibite with 

H38 solution 

84), ns to 

ensure 

o>nvplete 

prtfi|)ilnti*»ii 

Fb, lii, Cd, 

(he 

mi hi hides i>r 

which nre to 

snjnt* extent 

HH.duble in 

told dilitle 

Hi! 

If any 

further pre- 

eipitate is 

produce^l, 

rt imiv be 

added lo 

the original 

pre<*ipitate, 

ur exumineil 

sseparalely. 



The Anultfticiil Cltisdfimtlon of Meiah, 
Systemaiie Analtfsis* 

The following Tiiblt^, pving directirms for the analytical 
exiimitiatittn of the scdutimin for the presence of iiractieally any of 
the metallic radicHls hitherto eonnidere*!, indude and, to a certain 
extent, efntomize the Tables previriusly given under the different 
groups. The order of addition tif the ^r<iuj*-rea|jents i« arranged 
according t4> a carefully clevi«ecl plan which is set forth in the 
fidlowing outline of the annexed analytical Table* : — 



^The possible pregene« of tin, whether as stHtiuouB or stannic 8alt« ifi 
not considered in the separation described here, since, in the srst^Mnatic 
examination of a Rolntion which might contain tin, along with copper, 
mercary, etc., auy stAnnoiis or stannic sulphide is removed from thecaj>- 
rie, mercuric, etc.. sulphides before the examinatloa of the latter sulphides 
i f 1 1 roceeded with. \ Srr p. *JI4 4 ) . 



QUALITATIVE ANALYSIS. 



24.3 



OUTLINE OP THK 


ANNEXED 


ANALYTICAL TABLES. 




HCl 


H,S 


NHJIS 


(NH,),CO, 


HAsU, 




Ilg 


Cd ' 




Zn 


« 


Bs 


Mg 


K 


<CB meftjti- 








9 








n>«i« salt) 


Cn 


S 


Mn* 


IS 












dD 




•ll 


Sr 1 




Na 


Pb 1 


"^ 


a 1 

Si 


(^0 


Ki^ 








mBTtiMnj) 




1 

^ 


Ni J 




Ca 




NH, 


Ag 


Ph 


s 

1 














a 


Al 1 


. 










Bi 






1^3 










As 
(tts *r«etiaitB 




F« 






Li 






or aneulo 






S 










»U) 














Sb 


t 


Cr 


« 










Sn 














(u sum- 


fl 












not] or 














salt) 

Au 
Pt 


2 

3 
1 











Note-,—Th& student should |jmctice th<»t^iaini nation of $iq neons solution » 
of salts of tht^ above metaK i»y iiid of tlie Tablt*8, until Uc is tibl«j to iijHpr- 
tAtn with fai'ility and accurii<y whith nirhilit- radiciilji nrts |irLs«ul, In 
tlii»way he will beat pcn-'eivo thi* pt'eiiliuriliuH of e^ifli cleniont, iiiic! the 
tfi^nctnl reUtions of the elements to each other. 

The foreji^iiig: outline imlieut<»3^ that hYdrm-hbrnr ii(*id, which is 
the fir*tt gitmp-rrajrt'rit adiled, jUNHipits^te!^ silver uml, miniinius 
chlorirleii and pnrtinlly prcfipitiiteH !ea<l cblorithHiijiUNSM tbi* lead 
Mention ia verj' tSikik^). The ttltriite nlitained an reniaving the 
hydrtxrhlDric acid preeipit^itt* in next treiil<v] with hydrogen sul- 
phide, whieb j)rei'i|)itiUe^ the nietals of the rcipper ami arsenic 
j^foupM t'»gether nn siilphide?i. Th*» su1idiidef« of tbe^^e twi* grrnijm 
Iwhttve ditferently when digested v%ith i/^ihw jimimminin Iiycjm- 
Milphide {liv^ what eoine,-^ Ut tbe ^iitie thing^, ammnninni hydro.«nl- 
' .Sf<' Kx peri me lit 5, p. 141. 




344 




THE METALLIC RADICALS, 



phide and a pinch of sulphur), tbose af the arsenic group dis- 
solving in this reiigeut, while thoR! i>ri he c<ipper group remain 
ur»dL'4H<jlveiL {Str note uii p. 242). HrJiL-e^ when the ^^ulphides 
of the Iwo groups have been preeipiLiiLeJ together iind filtered off, 
the mixed precipitate i» Ireiited with yellow umrjioiiiuni iiydro- 
»ulphide so an to eti'eet the sepjiratinn <d' arseuie gr«mp MilpthidoA 
from the copper group sulphides, while the liltrate still coutainjs 
the metJils of the iron, 'imi\ jHid hjiriiim grouije along with niag- 
uesiuu) uoil the alkiUi metuls. 

A very tf^Jinmin mode <»rdejditig with the iiltnite (iind the one 
adnjited in tbe iiniiexed Tab!eH) it* t<i ;idd exeens <if aniuionia and 
then itiJiiiioiiiuu^ liydmsulphide t*i it. The ammonia first neutnil- 
hxs the hydroehlorie aeid prt*>^"nt in the fdtnite, (ijnning with it 
anHimiiium ehle>ride : — JH'l r NH^OH = NH^tJl f ITjO ; and a* 
WHJii ail this ;ieti<in has been eompleted^ it li>nri.s sooie aiinnonium 
bydrosulphide with tlie excess of hydrogen ?^ulf*hide jirescnt. Thiii, 
together with mf>re amnion inm hytln>f*ulphide which m added, 
precipitates, a» sulphide?^ or hydroxiden, nil the mcUik of the 
iron and zinc gn>u[)s. The ammonium chloride, fnrnied by the 
firnt intenictiim of the ammonia with the hydrochloric acid, pre- 
ventii the [*rccipitjiti*(n of iniigiicsiuni at Ihif^ stage. The metals 
of the barium group^ along with miignesjuju and the alkali nietalu, 
pa^j* into the filtrate. The lii^riiim group mctjds are suhyeipiently 
precipitated as earbmates liy the ad<lition of ammonium carbon- 
ate ; and magnesinm and, ti» s<ane extent, litliiuiti as phonphatea 
liy uicnns of amminiium phosphates, as alreudy dc^HTihed on p. 
12K, where the mode of dejiling with the other alkali -metals is 
also diseus}*efj. 

Mfthe accompanying Tables, the first inehiden directions for the 
analysis of an aqiieoui'^ or only slightly acid solution con tiiining one 
mhf of any of the metids hitherto ifUisidercd. Here the color of 
the i»recipitate or preeipitjitc.^ atlorrled by a metal given under 
circumsL*inee-s must hirgely he relied on in attempting the detection 
of the various elements. 

The fobled Table is intended aj< a scheme for the analvflift of 1 
sfilution?* eontaining salts of more than one metal It is a compil- 
ation trom the foregoing rcattionK and may often be alti*red or 
varitnl in arrangement to suit ttie requirement's id' the aimlyst* 

The analysis of w^hitions rojitiiining only one metal will Bcn'C to 
impress itie memory with the ehitnicti'rislic te«ts for the vari<aji» 
metals and other radicals, and familiarize the mind with chemical 
princiides. More thoruugh analytical and genenil chemica) 
knowledge h only uc<|iiired on working on *<uch ndxturesof boditti 
as are ntet with in actual praetice, lieginning with solutionH whicb 
may crintain any or all otthe members of a group {jtee previoU» 
paget^), then examining sohitions eontaining more tlum one gn»«p, 
and finally analysing liijuids in whieh are iJiasolved «e%*enil salts 
of any of the common or rarer metalti. 



I 



[7b face page 245. 
AN AQUEOUS OR ONLY SLIGHTLY ACID SOLUTION OF ORDINARY 
INTEREST. 



c) Cr Ba Ca Sr Mg LI K Na NH* 



Filtrato 
Co Ni Al Fe Cr 11a Ca Sr Mg LI K Na NH. 
Id NII«C1, NH4OH, NH4SH, warm gently aud filter. 



il Fe Cr 

■h a few drops of HNO3, 

riir, filter. 



Filtrate 
Zn Mn Co Ni 
/ with HCjII^jOo, pass lUS, 
filter.' 



Precipitate 

Zn Co Ni 

Roil with HCl and a little 

HNO3; add KOH, filter. 



Filtrate 

Ba Ca Sr Mg LI K Na NH4 

Add (NH4),C0„ warm, filter. 



l»reclpitate Filtrate 

Ha Sr (a Mg Li K Na NH. 

Collect, wash, disMolve in Add (NH«)-HAsU4,8tir, filter. 

HC^HjO,. add excess of ' 
K5.Cr<)4, filter. , 



Ppt. 

Ka 

Yellow. 



Filt. 
Zn 
Add 
Nlf^^SH 
While 
ppt. 



Precipitate 

Co Ni 

Dissolve in HCl, 

and pritcetHl as 

directc<l on page 

145. 



Filtrate Ppt 

Sr Ca Mg 

Add dilute HjfSOj White 
let stand, filter. 



Ppt. Filt. 

Sr Ca 

White Add 

NII«0Hanil 
|(MiJ,C,04 
White ppt. 



See aNo p 2.'>(», and the. 
more delicate si>paration 
given on p. I'iS. 



Filtrate 

U K Na NH« 

Evaporate to small 

bulk. AddNll«OU. 



Ppt I Filtrate 
Li K Na NH« 
8ee Evaporate, 
p. Z.'VO. ignite, dissolve.! 
I KbyPt(U, I 
Na by flame. ' 
INII^ in original 
' solution. 



QUALITATIVE ANALYSIS. 



245 






Zi^B 







»} 

t 









St:? 



9^ 



O I? 



4=1 









? = 2.2. 









s 

m 
•b 

til 



^ & 




246 



THE METALLIC EADWALS, 



The author I'uti not t<io stron^iy rwoD intend styflents thoroughly 
to niiLHtiT thi^ jirt (if analyHi.s^ not only on account of jtw direi't 
value, hut bw"iiu?«e \U jiractice euahles tlu'ui rapidly and Miundly 
to iicqnire a iijood knowledge (d' ('heinihtry, and groatly iinpnive 
their general men till fmenltieM. 

General ani> iS fecial Memoranj>a helatino to the 
pRi:rEi»iNG Analytical Taiileh, 

General Mnnoranda. 

Thene Tables are eonstrueted for the tinalyf*i» of njilti* more or 
le».H fiotnhk' in water.— The f^tmleut has Hiill to Jean* how suIh 
atanees jnrt*tluhle in wattT are to he br<m^ht into a state of sr^Iu- 
tion; but onee disswdved, their analysis is eHetted hy the s^inie 
Bcheiue as that just given. The Tahle.s, especially the longer 
folded ont\ may therefore be regarded as fairly representing the 
method by which inetallir constituents ofeheiiiicii! »ub»tancos are 
i<eparat4'd iVfun each other and reeognized, 

77**^ (jrftup'rcmjftiin adopted in the Taiiles are hiplroehhrir arht, 
hydrofjrti Huiphide^ fimmonhtm /ii/drmffiphidr, nmmoftitim carlMmfiff 
and ummattittm j^fioifphtttr. Jf a group-reagent produces no ]>recipi* 
tate, it is evident that there can be no mcndicr of the group 
present. At Ikst, therefnre, a<ld only a small (jnantity of a group- 
n'iigenl, and if it proilttccs no effect aild no more; for it is not 
advisalde to overload a solution with usidesi^ reagents ; suljstanees 
cx|K'cied to come down ils j>re<'i|»itates are not infri^juenlly held 
in !*olntion in the liijnid by exeesf^ of arid, alkali, or eoneentrated 
atjuetfus solution of sojm^ groiii>-reagent, thoughth^iwly addeil. 
Indeed, c.\|terienced manipulatfir^ make jpreliminary trials with 
group- reagents on a few drot"s only of the liipiid tinder exaini- 
nation ; if a precijdtate is produced, it is added to the bulk of the 
onginsil liquid^ and the addition of the group-reagent is continued; 
if a preeipitate is not produt'efl, the few drops arc ihnnvn away; 
aikd theiinnece.ssary addition of a gron[*-reagenl thus avoitled alto- 
g:eth(*r, an advantage fully niakiiig ui» for the extra trouble of 
making a prelindnary trial. — While shunning exeet*s, Jiowever, 
eare must be taken to avoid deficiein;y; ji snbstajiee only partially 
removed from solution thniugh the addition of aik iii.'^utlieieiit 
am<»unt of a reagent will appear w here not expected, l>e eoiii^tantly 
mistaken for something else, luid cause nmeh trouble, Iti» « g<M»d 
plitn^ when a group-reagent ha,H prtnluced a preeipitate and the 
latter has l>een filtered off, to add a little more of the reagent to 
the elear filtrate; if more precipitate is produced, an insutlieienl 
amount of the group-reageot wa^* intro^luced in the first instance ; 
but the error is corrected by dimply refiltering ; if nt» precipitate 
CK!eur», the mind is aaliatied and the way cleared for further oj aera- 
tions. 



QUALITATIVE ANALYiilS. 247 

Gnrnfy-precipiifiie^^ or any pn?cj|)itat*^s still retiuiriiig examin- 
ation, should, as a rule, be well wik-ilied before turther testing; 
thiH ifi to reniov e tlie aqueous E^ilutioii of othfrsubstanee^ iKlUeriiig 
to tbe prei'lpitate, iwi thiit Kiihsequmt r*'artioris uiay titkc place 
between tlie reajj^ent^ used jinil tbe precipitate only, — A j>recipi* 
tate is sometimeM in bo line a stiite of divifiiini w^ to retanl Elt ration 
by clogging the iK>re5 t)f tbe pajier, or even iu pass tb rough tbe 
ftiter ill together ; in tbej*e easi^ tbe mixture may be warmed or 
b<»iled (or a fresh (|uantity of tbe original solution may be warm e<l 
hfifore the grouji-reagetit is* aclried), which usually eauses aggrega- 
tion of the partieles of a precipitiite, and benee f:ieilitale.s the pai*- 
siige of litjuids. 

lHnMiimttfitorl\ — ft in immaterial whether a Holntion he lirst 
divided into grrjup-preeipitate^ or eaeb pricipititte be examined 
as ftfion as produced; if tbe forruer metbofl be adopu*d, confusion 
will l»e avoided by labelling or marking the funnels or papers 
hobJing the preripitab^ **the HCl itpL/' "the Up l>t>t.," and so 
on. 

Thr cfjlom and fj^fteml appenrniwe of the vari<nis sulphides and 
hydmxidea preciidtat'ed shonbt he borne in mind, an the aljsenee 
of other substances, as well as the presence of those [>reeipitaied, 
i« uflen at onee thus indieated, 

Aftplir^itittn of ratijirmttfnnj h^jifn itiust be frequent, 

HrjftfiU of (innlifKfH wlioiibl be recorded neatly in a nienioranduni 
book; a, for et>rreetiou and embirHiMuent by tbe teacher; b^ for 
future reference by tbe student or by those wh(* nniy need eviclenee 
renpeetiiig his lal>ors; and, /\ to promote mental orderliness. 

7^ mirioii* rrartifiHH whieb occurs in an analysis have aln-ariy 
come before the reader in going through the testn for the individ- 
ual met;d» or in other analytical operations; it is unnecessary, 
tberefor(% again U\ eonstruri etjuations or diagrams. Bui the 
reactions should be thought over, and if not pertectly clear to tbe 
mind, l>e written out again and jigain, till thoroughly understood. 



Specia I Mem o ntn da, 

7%f Hydrochhrk*tmd preeipiiaie nmy at first include some anti- 
luony and bismuth as oxychJorides, readily dissolved, however, 
by exceMS of acid. — If either of these elements Ik* p resign t, tbe 
washings of the preeijtitalc will prohnldy lie milky: in that ctu^ 
add u few *lrops id' bydnndilorie arid, which will dear the li»]uid 
and make way for tbe npplicatifni of tbe te^t for leatl— The 
Hilver chloride and mercurtms chloride preci]>itate j^hould not he 
long in e/>nt4ict with tlo' amuKMiia, or silver will he refirecipitated 
thus: — 

2AgCl 4- 2HgCl + 4NHj = NHg,l1, NH.Cl f 2NH,C1 + 2Ag 




248 



THE METALLIC RADICALS. 



The hydf'ogrfi xuiphkir prfeipitaie xjiay he whitij^h, in which caKe 
it is nuthiijg but. suljvhur; Tor, ils iiliviidy irnlicatecl, ferni! saltsi 
are roducn] by hydrogen sulj>hidt' In frrrtms, ami €hn>mate.s U\ 
chromic salt^t, tiiiely divided whitish ftul|*hur being deixisited: — 

4reCI, + 2H^ ^ 4FeCl, -{- 4HCI -\- 8^ j 



Bui the preeiintiiie miiy also be very shghtly yellow, or even 
white when only ji niercuric siilt m pres^etit, ihronjrh an insutti- 
eiency of liydrngen i4ulphidc having prodneed a fldoraHnl|diide. 
The g;a^ ishoubJ be piisived through the liquid until, even jifter well 
shaking, the latter smells strongly td' bydpi^eii s^dphide, 

Thi' pitrtioH of iht hydrof/m nulfJtitlr pirvipitnte diji^olvfd bt/ 
itmmfittmm kijdi'fiHidpkide niiiy include a trace of copper, cupric 
t+ulphide being not altogether insrjluble in ammonium hydrosul- 
phide. — On iidding hydrtichlorie acid to tbe junnionium bvdro- 
Kal[>hide nidutit)!^, whitish ut yellowish sulphur only uiay be prt^ 
eipitated, yellow amniDuittm hydrosnlphide always eimtaimng free 
sulphur. — f 'oneentrated hydroehlnric fteid doe*i not readily dis- 
s<ilve j<njall (juanlities of autimonious suljdiide out of much 
arsenrms suljihide ; and, on the tither hand, the concentrated 
hyiiroeh!oric aciil t4ikeM into twilution a t^niall quantity (>f an^cniuw 
snlpliiile if ivuieb antinioiiiuiis sulphide he present. The precipi* 
tates or the orginal f;<»lutions ,sh(Uild therefore he exjimiiietl by tbe 
other (hydrogen) tests for tbe>*e elements if doubt exixt« concern* 
ing the prest^nee or absence of either* Tin remains in the hydro- 
gen-hut tie in the metallic Rtate, dcpositeil as a hlack powder on 
tbe /ine used in the experiment, Tbe <"onteiit^ of the bottle are 
tiirneil ont into a dinh, i-hnllitinn continued until evolntion of 
bydrojff'ii «easi*h!^ and tbe /ini* is taken up by the cxc^'sm nf Hul- 
pburie aeifl enj}>loye«l ; any tin is tbcn lilt<*red c»u(. w;i>*!»e4l, dis- 
H<»Ked in a few drops of hydrocblonc acid, and the lirpud tested 
fm tin hy the nstial reagents. — Tin may l»e del4*rte<i m ihc 
mixed tin, ar^eiuc, and antimony sulphides hy tlie blowpipe 
reaction (p. U»r)). 

V*e portion of the ht/drogtn mi-ipkidt preetpitaie fw(. dij^afvrd hy 
(immonium hijdroftn/phid^ may leave a yellow scmt-ftiSLHl globuk* 
of suljdiur on Vniiling with nitric acid. This globnb' may 1m? black. 
not inily fn>m presence of mercuric sulphide, but alr*o fraui 
enclosed particles of other sulphitle^ protected by th<' sulphur from 
tbe action of the acbl. It uiay ii\m c<mt«in lead sulphate, pro- 
duced by the action of nitric aeitj on lead sulphide. In ciisca of 
doubt ibema&s mui^t b<» removed from the liquitl, hi>iled with nitric 
aeid till dissolved, the Huhititui evHporated to nnnove excess of 
acid, and the residue examined ; Imt usually it may Ik* disn*- 
garded. — IJcfore tcstitig for bismuth, any c<m»idcrahle excww of 



qUALlTATIVE ANALYSIS. 249 

acid should Ik* removed by evaporation, and the residual Uquid 
shotild \w freely diluted. If iiu jirefi|dlate (iiisiuuth oxvuitralf j 
ap|K*ar, amtnouium ehtririii*' wdiition may be added, bimuuth »»xy- 
chloride mori* readily formhiji tbiiu even oxyjutraW. Or, any 
nitric acid or i^uljdmric arid liuviii|f iM-eu neutralised by adding 
anuuouia, hydroeblorie jieid \a addtnl and then potu^^sium indide ; 
a rich unuipe eolor renultM if bismuth be [irej^euL — liismutb may 
alrto bt* detected in thi' mixed jinripitatid bismuth and lead bydrox- 
ides, obtaint'<l in tbc ordiruiry eourse nt analysis, by dissolving a 
portion of the preeipitHte in aeetie aeid, adding tbe liquid to the 
hot H^dutiou uf leiid iodide jnentimieil m the reartir>n8 b»r bisiiiuth 
(p. 2i?l).^In tcNtiti^ for lead by inenuH of t^ul|diurie aeid, the 
liquid nhr^uld Ih' diluted aud M-t a>iide for some time. 

J/rrri/ry may alsf* he if^olaUnl hy dii^^ewting the hydrogen huI- 
phide preeijiitate m sodium bydn»sulpbide, in?<lead of ammonium 
hydroMulpbide. The arsenic, antiiimny, tin, and mereury sul- 
phides are tints diswilved out. The mixture is then fdtered, exeens 
of hydroehloric aciil added to the Idtrate, and the preeipilatid 
8id|>hidej4 eolleet*^! on a filter, washed, antl digested in anumuiium 
hydrosulphide ; merenry sulphide remains insoluble, while the 
«irrt4:nie, antimony, and tin sulphides are di^w*>ived- liy tins 
iriethfxi copper also ai)j>ears in its rijfht phiee only, enprie sul- 
phide I'K^ing ini4«duble in .Midinm hyil r(*Kulphide. The other metaU 
are then i^eparated in the usual way, 

Thr mumohinrn hijdroaufphiiie prrripifaU' mti\\ if the original 
Ndutiou was acid, contain barium-gnaip and magnesinm ](ho.s- 
phat<*s, oxalates, Hilieates, i\w] borates. Thest* will snb«4'<juently 
eiHiic out with the iron, and, Im ing white, give the iroj» preeipi- 
tate a ligbt-eobtred appearance ; their examination nuist la- vuti* 
dueti'd stq>arateiy, by a met hud ilescril»ed snbseipiently in (onnee* 
lion with the trt»atinent itf sni"stan<-es inw>hdjle in water. — The 
priM'ipiljite containing aluminium, iron, and chrominai hydroxides 
fiftini contains wane inHnganesi\ Tliis manganese m;iy l>e deteeled 
by washing the hydroxides to remove all trace iif cbloritles, Iwiil- 
itig with nilrie aeiil, adding either lead peroxide or red leaii, ami 
setting the ves8cd aside; if numgiinese he present, a red (*r pnr|tle 
liquid is pnwiuced. — Nickel sulphide is not easily removed by 
RltrHtion (*rcc p. ]4'A) until most of the excess of ammonium hydro- 
sulphide han been dis8i|>at*'d by pridimged ebullition. 

The ftmmorttitm carimmifr precipitatr nuiy not contain the whole 
of the barium, strontium and ealeiuni in the mixture, unless free 
ammonia l>e present ; tt>r the earborniteH of tliese metals are solu- 
ble in water ehargecJ with earlxmic aeid. It", therefore, the liquid 
is not distinctly amnion iaeal, ammonia water shouhi be adrjed. 
— Neither aninioniuni carbonate nor aiinnonia wholly precipitates 
nuignesium salts ; and as partial [» reel intuition is undesirable, 
luiimontum chloride, if not already present in the liquid, should 
be added. — In the Table opposite p, 245, it is directed that stron- 



250 



THE METALLIC RADICALS, 



tium be »eiMi rated Innii eiilriuni by adding dilute wuiphunc ml id 
to tb<?i acetic aci*! wihitiim. This rengeiit, uiiK'sj^ extrt'iiifly diluU', 
may precipitate calriuiii* Any nacb loss nf ral< iiim b in itself i»f 
UttU^ ct)nset]iunce, bocjiu^e ciniuji^li rjilcituii snijduito reJiiahiH in 
\\w tilt rate t<» att^^>rd a calcium reaction wlieu anun(»uia water 
aniliiuinioniuui oxalate are !*ubseiiuently add«*«L But llic eak'iuin 
»uljdiale precit^itated l>y tlie sul(»buric acid may be wrongly f*et 
dnwn jLH Htrontiuui sulpliEite. Tberetore ttvt a little n^ tbe acetic 
at'id sulutiun for stnmtiuin by addin^i; an af^uctais H<j|iitiun <d' cal* 
ciuni jiulpbatt', wben, if no prtx'ijutiUe fali?^ iiller stating aside for 
!-<nTral minute?*, strontium may be regarded t^ al>sent. If a pre- 
cipitate occurs*, rttnnitiiiin is pretw^iit i the reM of tbe aeetie acid 
solution is tbcji teste*! for calcium a^* directed in ibe Tiible, the 
tinal testin|j[ by meiins fdrmimonium oxalate l>eing, of course, pre- 
ceded by the addition of aimnonia water. liiirii^m may be over- 
looked if oxidation bappens to bave converted any sulphur into 
sulpburic acid. 

Lithium. — Should a f>recipitate, siipp^ised to be due to lithium, 
be obtniiicd, it must be tt^nted in the BuJisen rtauie. If tl»e 
characteristic criinsi^n tlann' coloration in not obstTValjle, tUe pre- 
ci[>itate is jirobably due to a stiiall cjuantity of mapiie^iuni, which 
not iufrctjueiilly shows itnelf under tlie conditioiLS recpiisite for 
the precipitation ni lithium. II' present only in minute propor- 
tions, the lithium may also remain with the (ilkiili-met^ils; it can 
then be detected by means irf tbe sjrt'ctroscope. 8ucb a meth(*<l 
of examinatioti is called wpeitrnm analysis, a subjdHt of much 
ititcrcKt and of no^rcat ditficulty ; it will be destrilK^I briefly in 
connectiim with tbe metbodH of analyzing ft«did substances. 



" ^eterib 



QUESTIONS AND KXKRCISES. 



ribe a ireneral aiethotl tif analysis by whicli the metnl of % sitijrle 
aalt in a sohitinn eould be t|ijirkly detoLtexl. — ibve ilhistnitioiis of black, 
whitti. buff, yelluw iiiid orange sulphides. — Miatina tfu' Kroap-r<?*^'at* 
usually eiiipktyed iu aimlysLi,—Undor what circa riistaneos may a hydro- 
chloric acid precipit4it« cf)ntair aiitiininiy ur bismuth ?— If a hydriwcvii 
sulphide prccliiilate b white, what substanco.H are indicwted ?— tiiire 
pnice««ea for the «7ualitiitive analysts of liqynls containing tbe following 
substances :~a. Arsenic and ("adniinm. h, Bisamtli and Antinomy, 
c, Antimony and ^[crciiroijj* sal tv d. Silverntid Mer<MiPC»UHsalts. t. Fer- 
rous and Ferric sjilt. /. Aluminium, Irrm, and rhroniiuni. i|, Arwnic, 
Anthiiony, and Tin. h. LammI nnd St matin ui. i Lead and Mcnnric salt. 
/, Copptr and Arsenic, k. Ahiniitiinui and Zinc. I Inm und roj»j>er, 
m. Iron. SfMliuni, iind Arsenic, n. M*rcury^ Man^'AueM', and Magiie«^ium 
0, Zitic^ Mtttigttuc«e, Xkkfl, and Colialt. p. Barium, Stroiitiuui, )iud 
(klciiim. 9. Zinc, Mai^ncsium. and Amuioniuni. r. Alnmintum nnd 
Mii«n)<^inin. «. Iron, Banum, and Potaxslnm. f. Maj;n*'Hium. t!!idci(tm, 
Asd Potassium* it. Silver, Antimony, Zinc, Barium, and .\mmouiui». 



THE ACID RADIVAl^. 



251 



THE ACID RADICALS. 



With the exce[»tion nf amnioniuin, NHj, the lwinity-i*even radi- 
cal)* which hiive up to this |n>irit mainly fK'riqMtHJ sitteritioiij nrt* 
mctiil-i. They h:ive iMicii stiiihL«l tor the iiiost jmrt, not in the 
free or irneoiiitMneti state, hut in the enJiditioii in whieii they exii*t 
in iwilLs, I. e., *u* tlie metallic ra<:li<"iils u( saJL-^. As alremly men- 
tioned ('ftr p. 05), *ialts rnjiy be repinled ils enmptisSiHl of a metal lie 
radical united with an iitid railieitl. Kvery aeid, t/>o, may bi? 
rcgiirded as eoiinistiji^r u\ hyilru^n^n, which jdays the jiart of a 
uietidlie mdieal, iiuilcui with at) acid mdieal; ami henee the acids 
are .sometimes eiilled hydro^^en nalts. When the place of thin 
hydrogen in an aeid is taken hy a metal, the product is simply 
C2il1e<i a Hiilt. In this section of the Manual, we ir^hall tjike up the 
study of a numlxT of inipurtnnt salts from the point of view of 
the aeid nidieals which they cnntairj and, iiieidentally, we shall 
al»i» study the steidH, in which these radicals occur in eomhiuittion 
with bydrojiren* 

Juat iLs thca^ are iiuivaleut, bivalent, etc., mctidlic radicals, m 
there are univalent, hivjilcnt, etc*, tieid nidicals. The acids cur- 
re5pondin^ to the^e radirals eontafn one, two, etc., atouiB of 
disftlaee;ihle hydroj^en, ami on this account are c-alled nirmobiLsie, 
dilnitfie, etc, aeiil>< : thus, hydrorhlorir arid, \iV\, is uinuobasie ; 
sulphurie aeid, H.,S(>^, is dihasit ; orthtiphn.sjdiorie aeid, H^PO^, 
\i^ trihsiMc. Acids of hip:her basicity i^re alj*o known. 

The student shmiM note carehdly the signification of the wonif4 
nirontj and n'lak la^ sipjdiiil to acids, and jnust not eonfuse the 
ide;irt implied by ihi'^e lerm>^ with those eonvived respectively by 
the ileseriptiou of acids \\a vutttfui nttful and dlhitf (not necessarily 
*Nlihite<l/' i. r., prejiared by diUttion). A strong arid is une 
which exhibits the charartersof an iieid in a w'ell-inarked manner, 
while a weak acid only poss^exaes these characters to ji limited 
ext4*nt. ( Vmsideri'd in this respeet, stilphuric aeid is a strori*; 
acid, while «eetie aeid is a weak one. The »ta(f of runrmh-ation 
of an acid U *»i1:eu described iis \U *' strength,'' but this uMij^e is 
not to l>econinien«h/d, the.'^in^de wonl "concentration " beinj* the 
tenn whieh is now usually em]doyed in cheat istry to desipiate 
this degree f)f eonrcnt ration or '* state of concentration." Snl- 
phuric acid, evm when dilute, is still a str(jn^'^ aeid, while acetic 
acid, even when bi^rhly crmeentrated, is t^till a comparatively 
weak &L'h\, With re)fard to two sjunples (»f dilute acid, the one 
of which contains, say, fifteen, and the <jther twenty percent, of 
mtlphurjc acid, it would lie correct to sjiy that the ro/iernti'ation of 
the latter i« greater than that of llie former; i, «\, thai in any 




252 



THE AVID RADICALS, 



given v^iluuie of t!ie latter 5«*lutJi>ri there ia more suljilmrie acid 
thtiti in the same vulunie «»f the Ibnner *i»luti<iiL 



HYDEOOHLOEIO ACID, HCl, AND OTHER CHLOEIDES. 

The aeid radical of hyiJrtRhlorie aeid itnd of other chlorides is 
L* h 1 1 * ri n e, t_* I , C h h » ri lie oieii rn. in 1 1 u t u re v h ii^ tl y tti^ w mJ i w u i ch 1 o ri de, 
NarL Stnliiiui eiihtride i» a very abundant ^idManee, iKTUrring: 
eitht'r sulid as roi^l'Milf^ deiioesits of which exist in t'heshire, at 
8las8furt, and elsewhere, or in solution in the water of all i^eskB. 
t^'oinnioii tahle-hidt is more or U^^ pure sodium chloride in minute 
cry stain. Chlorine, in hydrcKdiloric acid and the chlorides, m 
univaicnl (tV) ; its atomic wuijrlit is iir^lK, The niolecular 
formuhi tor chlorine is CL. Hvdrochlnric acid is a monobasic acid* 



HYDROCHLOEIC ACID. 

lixperiment 1. To a few frugments of s^mIuhu chloride in 
a lest-tulie or ^luall tlusk, jidii abnit an n|iml weight of t^u]- 
phuric acid ; colorle&i hydr(M*hloric acid gas b evolves I, and 

Fju. 37. 




Prt^paratton of hydrocbloHo Bcld- 



eodium hydrogen sidfdiate reniains. Adapt lo the mouth oi 
the vessel, by' means of a [w^rforated cork, a piew of glutt 
tubing bent to a right anglt^; heat the mixture (Fig. 10. p. 34, 
or Fig* 37p aUn-e) nnd convey the gas inl^ a little water j 
solution of hydrochloric acid results. 

+ H;^0. ^ HCl 



Naa + H^O, -^ nKi ^ 

Sodium J^ulfthniic Hydrf»ch!orlc 

i^liloHile neid acid 



HiMlliiiii hydmitii 



CHLORIDES, 253 

The product of this opemliou is tlie nearly colorless and very 
nour liquid t'oninionlytenjiwi hydnx-hloric sicid. When of cfrtjijri 
**coDceiJtratiijris '' (det<?rmiiu'd liy vulunietric analysii*), it forms 
Aeiiitim Hijdrochtorirum^ U* t?. P., Acidum Hydrochhncum 
DUufttm^ U. S. W Tht* former ha^ ii spedlie gnivity of 1.158, 
and contidtiH 3L9 jifreent, f»f real lU'id ; the latter^ specific 
gravity 1.041), with 10 i>ert'ent, of real acid, is made hy diluting 
lOQ parU by weight of the more con cent rated acid with 21!* part** 
of wtit4?r. The jihove proce** is that of the uianufaeturer— larj^er 
ve«K*l» Ix^iJg etiiployetl, and the gan hein^^ freed from any trace 
of sulphuric acid hy washing, tuber chlorides yield hydro- 
chloric acid when heated with si|lphuric acid; but H>^lium chloride 
ifi utwayH u^ktd Ix'cause it is plentiful iind there lb re cheap, 

fhmmercial hf/ttrochhrk' avid is ii hy-]jrcKhtct in the manufacture 
*if Nidi urn eiirhonate frmn conunon sidt (hy the process in which 
Bodium chloride is first converted into sulphate, hydrmldorie acid 
being liberated ami diss«^!ved in Wiiter), The imjmre acid has n. 
yeUow color and it* habh^ to contain iron, arsenic, alkali-metal 
saltan, .Hulphuric acid and nitrous* compounds ; siHuetimc?^, also, 
sulphurous acid or chlorine. 

invimbk fjaxeous htjdmchionr aeid forms visible gmyish-white 
fiimea on eomiug into contaet with air. This is due to itn ahstrnet- 
iog moisture fmni the air jind dissolving in it, the funjes eouHisting 
of nunute partich:^ of solution of hydrochloric acid. The great 
readiur^ with which hy«lroehloric acid gas dis.solve,«i in wflter in 
i^trikiugly demonstrated on opening a test-tube full of the gai^ 
under water; the latter rushes into and instantly fills the ttd»e. 
If the water is tinged with blue litnuin, tlu- acid character of the 
gjw ii* prtltily shown at the siiuie time. The test-tube, which 
nhould be perfectly <lry, may be filled from the <leHver>-tube 
diaH't; for the gas is s^jniewhat heavier than air aud therefiire 
readily displaces it. At low tempt^ratures hydrochloric acid and 
water form a crystalline compound, 11**1. 2H,0, 

Noir. — The [»roce*w, as de*<cribed (p. tU'Z), includes the its<^ of 
as much snl|)huric acid as is necessary for the production of Ihe 
acid Hodium sulphate, NaIIS<>, which renuiinw in the generating 
vessel. A hot solution of this residue, neutralized by siKliuiu 
itarlxmate, filtereti and set jii^ide, yields nornuil sodium sulphate 
{Sfjdii SuiphftM^ U. 8. P.), ftlaiiheVs Halt, Na^St\JtjHI/), in the 
form of traiisf»anNit, ohlitjue, cffloreseeut priMaiB. 

2NaHSO, + Na-CO, = 2Xa,H(), + H,0 + CO, 

Sodlttoi hyilmgeii SiK^Ihini SftiUutii %V«ti?r tVirtionir 

ralpllAte cartmnak* sutphnlc nhliyilrldo 



fn the commercial i»reparation of si»dium suljihate for the 
manufneture of ttcKlium carhouatt^ hy the Leblane proress, the 



J 



254 



THE ACID RADICALS. 



prf>purlioiit4 m whit h tlie hikHuhi diloridf and the sulphuric acid 
art' eni|ilc)yL"<i lire those rec[uired Uj iorm ntinual s<Mlmni sulphate 
ami nut iuid HiKliuiii >iulphiitt5. Tot'Mrr^^out this reuciion h higher 
lempeniture im uccessiiry* 2NaCl-f Hj30^= 2HC1 -j- Na,S(>^. 



OHLOEIKE. 

Experiment 2. — Ti» soiui^ drojis of hydrochloric acid rthat 
h, the fcmiTiion afj^wius scdiitiou of thi^ j^nis) n<hi ii few grains 
of hhick miiDjj;Hne?*e oxide, luid wanii the luixture; chhiridt* is 
evolvf'ft, ami may he rei-ogtiiiU'rl by it.< peeylinr wlar ami by 
\i» highly irrilJitiiif^ etlect on the uost* ami air- passages, 

4HC1 + MnO.^ ^ CI, -f 2H,0 + Uni\ 



Chhritte wittrt\ — Liq^u^r CUorl fhmpfmtvjt, the chh^rine water 
of the U, H. P. is prepared by di^^tdviagin water the gas prodm-ed 
by titling on potiiSMiiini tddnrate with hydroehlorie neul dihiteil 
with it^ own widght of wiik^r. Il e^iaLains wane oxid**;* of chlorine 
and potassium chloride. At firdimin- ternperature.s, if fre>h aad 
th*iroughly natnruted, chlorine water coatuins ahiait 0,4 percent, 
ofchlnriae. When ehloriiu^ water m exposed t<» dayhght, the 
chlorine slowly dce*aiip<ist\H water with prctduition of hydrochloric 
Hciil and oxygen; hence the noliition shonhl he frcKhly prepared; 
it is la'st preserved in a green glass well-stopjjcred bottle in a cool 
ftnd dark place. Chlorine i)as8ed into erdd water yields crystals 
of clilorine hydrate, C]j8H2(>, ^^^^^ these, when heated in a scaled 
tulw* under pre>»sure^ give an upjuT layer fd'chh^rine water and a 
h»wer lay IT of lUptUl rhfonm', 

Nofr, — T*j obtain the chlorine from other chloridesi, such as 
sodiuai chloride, sutphuric acid, ax well as hhiek maagancMMixidc, 
nnist he added. It may be assmaed that liydroLldi^rie acid i» first 
funned by the actum of sulphuric arid on the S4)diuai chloride, 
nnd that this then intenicts with black aumganest^ oxide and 
aiore swlidiuric acid to forni chlorine, mangauous (<i}t[»hate, and 
water. The Iblhi^ing eiiuations may repres4'nl these alejis^ in the 
priM-'ess : — 

2NaCl -h H,80^ = Na^SO, f 2HC1, 

MnO, t 2Hri I H,H(), = CI, f MnS(\ 4- 2H,0 j 

or the whole may hv ineludfd in nai" e<|UHtiou : 

2Na(1 i Mrit), d- 2H^SO, ^ Na^t^ H MiiH«>, ! 2H,n + d, 




CHLORIDES. 



255 



This reaction may ^K-cii^tirmally have antilytical interest, a very 
mtiall quiiiitily ol vhloriilc boirig recogiiiiyible by its means. But 
the iVilJuwiitir reai tii*n is nearly always apiilicaible lor the ilete<'- 
lionorthiselenienl, and lea vea little Ui be dusired in point of deli- 
cHcy : — 

Anahftieul Reaciiotis of Chlorides. 

To a dr<:ip of hydriKlilorif uoid, or Ut a dilnt<' H>lutit»n of any 
other ehloriili', udd si»hiti<in fd' Hilver nitrate ; a white en rdy prtn-ip- 
itiite of jiilver ehhiride, Agil, ij^pnidiHed. FVmr uway the sujier- 
natHJit bV|uid, itdd nitne atiil, and hoi I ■ thv (*rer4»ilate dorn lutl 
diKsfdve. F<inr fiway thr arid, and add fUlute iniurH»nin water j 
Ihf f>re*-ipitat<^ <[uiekly diss<ilve?i. Nentrjilize the solution by 
jutiiiii}^ an aeiil ; the rurdy |0"eeiintat4* a^'-ain ajijiear**. 

The formation <irthi^ while |>ri:eif«itate, its apuearaiieep ins<du- 
hility in boiling iiitrie jM-id, «i>iubility in ammoniit water and rt^pre- 
eipitation by rijiaeid, tV»rm, in the known al)seuceof bn)niide, abun- 
diint evkleme id' the f^resein-i* <d' eblnride. 

If free hydroehlorie jieid W pre!^t*nt in a quantity in a solution, 
it HJH, in additiioi Uv the reaetion with silvir nitrate, ^ive rise to 
Rtrfin^ effenc^eenee on the addition nf a earhonat*', a ehl«»ride 
beinj^ formed. The elilorine in iiif^oluble rhh»rides, i^ntdi its eiilo- 
niel, white prceipitiite, ete., nriiy lie detvetefl hy brjilin|r with rans- 
tie alkali, liltering, a^ddnlatiiig the tiltrate hy means ot'nitrie arid, 
and then adding the silver nitrate, 

. I ntidotf*. -— [ n ea,sei» o f po i ho mii^ 1 iy !iy drochl o ric aei d , »o I n ti on 
of sodium ejtrbonate (eomnion wsisbing-twjda) or it mixture of 
magnesia and water may be jid ministered. 



QUESTIONS A.VD EXERnSES. 

Why does hydrothloric ami jjas pivi* vbible fimi*^^ on connnjrioto roti- 

I fcict with air?— Howmueh Mrxlium nhloridi^ will Tk> n-qomt! to famish 

LWK* I»«>'oid *jfi'hh>rine Y— 4 Jivi> the iinalytinil rracttoa« (>f thlorides, -What 

mtitiilriti':^ may be tMlmiuigtcrei] in vmi^k of jioi zoning by hytlrochlork acid ? 



HTDROBROMIC ACIBp HBr, AND OTHEE BROMIDES. 

Hromif*^ :Sftnrrt\ /Wpftrafimt ttad /Voy<fr/'/rvr.— Theai*i*l rudieal 
uf hydrobromic aeid and «(ther f>n>inideH is broniiiie, Wrilltovutm^ 
U, H. P*V nrninine ^K'l'urM iti nntnre in the form of bromides in 
t!eii*watt»r and eertain siilint* r^f^rin^s, and is pn^piired from the /o7- 
trrn, or re^^idiial lii^uoiv of jydt wf»rks. It may be liberated from 



256 



THE ACID RADICALS. 



hnmndQ» by a process similar t*i ihut ^ in ployed fur liberating 
ihlorinf from rhlurides — that iw, by bcatiri/u' vvitli biiiik UiauganetJe 
uxide uiul stil[>hiiric JU-id {w*r nuti- on |i. 2'v4) ; but is uow largely 
ubhutied by lilK'rutiiiiJ^ it from broinidcH by lb*' iirtion of chbiriDe. 
(('iinifjiire Fi^actioii, \k 2r>7)- It is durk-red vnktile licjuid of 
Mpecitie ^mvity, 2.*JV» to t^J} at 15^U, and |His.Ht\'<,sing an odor nioro 
irritiilin^, if]»ossibk% tban tbat of rbiorine.— Its boilin^^ point b 
l^H^'C. (\4i'\A° I"\). Bniniin*" in bydrobroinic :icid and thebroni- 
i*b'i<, is univalrnt (IJr''). Uh ut^imic widghl i.s 7*JJM, and ilsmole- 
fular fonnnbi is Br^, 

Hijtlrnhiomie tuid^ — Hydrogen bn^mide, or bydrobrotnic acid, 
may be aiade by deeom|io,Hing jdiosplitirons tri-bronude or penta- 
bnmdde l»v mean5 id' water; J'llr, | 3n,0-=aMlirf lI.FOj, or 
PBrj+4H3b = 5HBr4-H3PU,. A i*njall quantity is prepared by 

placing seven ctr «*iglit dropH 
Fio. 38. of l>rniniiiL' at tbe hott*jm of 

a k'.st-tulH', putting in fnig- 
nienti* of ^bu<a to tbe height 
of about an ineli or two, tlieii 
leu or eleven grains of red 
pbosjdiorus, then another 
ineb of gla^ss, and finally a 
coujde of inches of glasa 
fragmmtH iiligbtly wet with 
water, a <leUvery-tulM* bidng 
titt«'d by means of a eork. 
Tbe phosphorus eombinas 
readily, almost vujlently, 
with tbe brouiine as ioontwthe viiporof the bitter, aided by gentle 
hratin^% conies into eontart wiUi tbe phtjsphorus. The phos- 
phorus tri-bronude thus formed then sufTers V»y (ien imposition by 
the water of tbt' nioij^t ^^lass, bydrol>romic ami phosphorous aeida 
bring pPKhieeii. The hydndiromie a«"id gas psisses r)ver (further 
heat beinj; ap|died in tbr lakT stage?* (*f fhe operation) and may 
W led int<» watrr i^r aniaionia waiter, Tbe latter srdution on eva{»o- 
ratiou yields ammonium brornitie. 

Solution of bydrobrotnie arid njay also be prepared by passing 
hydr^jgen sulphide through bromine i-overed with water, nntil all 
eolor has disappeared, and tln.'U <listilliiig the mixlyre, lOBr^-f 
4H,S^ 8H,/J = 2<)IiBr+l'H/^044 8 . A faetter method i« that of 
Sef>tt, who prepares [>ure s<dution of hydrol>n>mie arid by pacing 
purified sulphurous anhydride into water lyinp over a layer of 
bromine, until u homogeneous liquid, still nlightly yefltiw from thr 
pnxnce of free bromine, is obtained ; and then distil linij tbift 
liquid several litiieR, so as to remi^ve imeombiuHl bromine tmd 
traee* of sulphurie neid. Br, FS(>,4 ^H^O^^IlBr-^ H,S(V ^^'f 
rapidly obtaining a sidution of hydrobromie aeid on a sfttimll ^teale, 
H* Marshall recommends the aildition of Hutphuric aead to a 




Prepumili^n of hydrobromie acfil. 




BROMIDES, 257 

sulurated solution of biiriniii bro?iiiili', lu a qniintity Dearly but Jioi 
ijuile .suttideiit to prt^t'ipitate the whnh^ of tin* barium iia wulpbate, 
lulliiwi'd by filtralitiu of tbi^ i»«iiuiiiiii^ ami *lii*tilljUioii. 

ilytlrobnimif arid, like tiyclrockbirif acui, is numuhaHic 

Acittttm Hydrohrommtm /fiiutym, U. S, P., is |irepare«l by liie 
distillation of jiotai*siuui bnuiiiilv witlj eoneentrati'd plioinphuric 
jiciU. Its sjH^citic jj^mviiy is 1J>7(j, and it cmitiuiiw 10 jjercent. by 
weight of bydrogen bromi<le, Hlir. 

I^jOv^num BrotfwJe, KBr, in very largely tnnj>loyed in pbamiacy, 
aiid may be nsed in studying the rejietions of bromides. The 
metlifHl of 111 {I king tbe wait luus been alludetl to under the piitiis- 
sium siilt» (\K SI). 

iSodium Bi'omkie crystal I i /en in anhydrous euben, NaBr (nmi 
*H>luiion.H at llfl'' to '\*2{}'' F. (4'18^-4K.H^ C. ), and in hydrous 
i»mnL% NiiBr, 2H^* >, at ordinary t^^mpcrature^. 

Amtminii/m Bntmut*\ NHJir (Aititnofiii Bromkhtm^ U, 8. P») 
may be made h\ nentndi/jnt^ bvdrobromie jteid with aaimonia : 
HBr-^NMjOn^ MI,Br F Wp' It forms rolorlessery stain which 
may bi'eunK* slightly yellow m% rxp<jsure to air. It iw readily 
soluble in water, le«s !*o in aleobol, jind sublimes win ii heated. 

Of her bmmid^jt arc seldom iiHCfl j they nniy \h' prepared Iti the 
way a>* the eorresponding chlorides or iodides, which they ekw^Iy 
n^-'udde. 

Bromine Te^t Solufhm, U. S. P., (Bromine Water) I part in 100, 
14* an af]ueoui» !<olution, Itroaiiae l>eing slightly soluble in wat4*r, 

I/*jpo&romife^ and Brnmafe*^ analogous to hypochlorite's and 
chlorates, c^n easily be prepared. 

Bronjate*, i>ecurring its impurity in bronjides, are detected by 
dropping dilute nulpburie aeid upon tbe salt; a yelbiw color, 
due to free bromine, is j>n Minted immediatrit/ if bromates ar© 
pmtent : — 

KBr 4- H.,S<\ = HBr + KHSO^ 
KBrt), -\ H^'^O, - IIBrt), -f KUSO^ 
5IIBr -{- IIBrO, ^ liBr, | liUp 



Anahjiie^il Rractloit-* of Bromides. 

!♦ To a frw drojw of a s^iliitioii of n lironiide (KBr or 
NjHjBr) add Holylioii of silver nitnile ; a yellowieh-wbite pre- 
rifatdte of ??ilver bromide, A^iBr, m^ pro<lueed. Treat the precij)i* 
inti* mtx^^mively with id trie aetd and dilute niivmoniii water, 
aa dejHTilKH! under silver ebb>ride; it is di^'Holve<l by the 
nnimonia s<dution, but somewhat less readily than the silver 
rhloriile, 

2. To a solution of a Itroiuide add a few drc»[wi of ehlorine 
water, or pass in some i>ubble8 of chlortDe ga:& ; then add a 
17 



258 



THE AVID RADICALS. 



few dro|>,^ ot'cliloroform, or ether, ur riirhoii di?ulphid<:*, shake 
the inixturt% ami set tht^ test-tuhe aside; the ihloritie displaces 
the Irmniine, >vhich is dift.st>lYed by Uie chlomlbrm, ether, ur 
(■urlM>u tlisijl[ihide (tlie solution Ikllitig to the liottorn of the 
tube in tfio rnse of tht^ lieavy chloroform or ctirboQ sulphide, 
or risiii;^ to the top iu the cjit?e of the light elher). The st>lu- 
tioii of i>nMnini* bus ii distiiitl yellow, or rethliisb-yelhiw, orre<i 
roliH% jiieording \o the imioutit of lu-oiuiue pre^^nt iu it, 
2KBr-fCl,-^2K01 + Br^ 

AW^ — ThiH reaction server for the isolation of bromine when 
mixrfl with many other !<abHt!Ui(:i*s. Exee?^'* oj' riilorine niu^^t Ik* 
a voided, jl^ eolorle^ss bromine rblorine in then forinetl. Imlides 
^ivc a somewhat siniilar iippearaiicc; the abstmee of iiwline must 
therefore be ensured by a jinueHs ^iven in the next weetioa. The 
above sohUion in ehlorotbrni or ether may be removefl from the 
tulie hy drawing it np ijit«» n /n'ptiff (small [dpe — a narrow gljusa- 
tnbt\ usuidly havini^ a bulb f>r ex[Hmded porliori in the ndtidlc); 
the bromine whieb it lontains may be converted into relatively 
non-volatiIesidL»i hy theadililifin r»f a drop of solution tjf potJissium 
or sodium hydntxide : the rhlorfd'ortn or ether may then be removed 
by evapomtion, and the residue tested ha ili^-ribe^i in the next 
paragraph. 

3. Liberate bromine from a bronibk by the eautious a<ldi* 
tion of ehbirine or i-blorine water, I hen add a few drops of 
cold mneihige of nlareb ; a yellow combinntiou of bromine anil 
sturch, termed **8tar€b l>ronii<le/* is formed 

Bromine may al»o be liberated fn*m hromideK by addinfr concen- 
trated «ul[>huric acid ami wmeblacic niangjinene oxide, and gently 
heating. Even .'^ulphnrie aeirl alone, if concentrated, lilieratej* 
bromine from a bromide, tlie hydrogen of the hyrlro!)rouHC acid 
rfindiining to some ext*'nt with the oxygen of the Md[>huric acid, 
and the latter being reduced tf» »tdph«rmm anhydride : — 

2KBr f 2H,K0, = K,SO, -h Br, + BO^ + 2H,0 



HYBRIODIC ACIB, HI, AKD OTHER IODIDES, 

Iodine i-Sourfe, — The acid radicals of bydrio<lic acid and other 
iodide«isi<Mline, I. Iodine oerurM in nature in the form of i(Kiide«» 
in se;i'Vvat<T. 8ea- weeds, sponger, and other marine organisms* 
which derive much ortlndr ii<mrit*hment from sea-water» stxire up 
iodides in their tissues ; and it is from the ashes of the?*e that sup- 
plier of imline {fodum, U. S. P/|, arc obtained. Iodine also 
oeciars in the form of iodates iu crude sodium nitrate. 




IODIDES. 



Preparation. — The sea-weed ii^h, ur kdp, is trejiled with water, 
insoluhle matter thnivvn uwiiy, juui thedeeanled Utjuid evujMinittJ 
iLncI Hct itsidL' to allow of the iie[H»sitioii of iinu^t nf the Hotliuiji uiui 
jM»tJ*5?<ium aulphiitt's, farbonati's, aiul rhioriik'j*. Thy tr^idual 
iiqiiur is treut€*il with t'Xcrss iif siilphurii' mu\y whiih riiuw/s tnnlu- 
titm uf e^rbtmif anhydride mni id'sLil[djunnis aiihydridtMir liydro- 
gen suljdudi% dt'imsition i>f sulphur and more sfidium sulphate, and 
h>riiiutii>u tif hydriddicurid. To the deuuileti li*]uid black uyan- 
giinese oxide is added, and the mixture ir* then sluwly distilled; 
the iodine suldiMH'w and ia allerwards puritied by re^ublimalioii. 

I*ropfrfit\H, — ^Icidine i8 a eryj^talline purplish-blark nolid ; it.s 
VHpor, readily t^^en on heutiiig u fni^nienl in a lej^t-tube, is dark 
violet. The vapur is irnt:itin|^ to the lungs ; hut a Iraee may he 
inhaled with K:ifety. Iodine iindUs at iLtil^T F. (IH^ C), boils at 
alxmt3I*2°F, (2M0'*C.), the lirst portioUK eraUaining any cyanogen 
icMlide that may be [)re.senL The latter suhntanee, whiidi is rarely 
present in iodine, form » slender, colorless prifiins, wMch emit a pun- 
gent THlor. 

tSftiution o/ Iofiint\ — Fudine is slightly wibihle in water (i*idijie- 
WHter), and readily Holuhle in an atjueouH soluthin of potassium 
icxlide.* Five parts (»f iodine and ten of jioUiAsium iodide, dis- 
wjlved in suffieient distilled water tn make 100 parts, form Litptor 
loHi f'ompimifttjt^ IT, S. P, T^Hffttrtt lmh\ \L H, 1\ in an uh'ohf>!ic 
preparatifm of diftereni strength, 4 parts of iodine and 4 ofpolas- 
wuiii iodide, mlibed with 12 of glycerin, and 80 of benxoinated 
!anl, form Unguenlum lodi, U. S. P. 

Iodine ortnihines with sulphnr, forming an unstable prayinb- 
blaek, wdid iodide, SJ,„ having a radiated crystalline structure 
(Suf/ihttns Ififfithtw, V. S, P.). 

ItMline in hydriodic aeid and the iodides, is univalent (l'\. The 
ntonii<" weipht of iiidine is 12'iJ* ; itm moieeular formula is I^. 

Iftjfhifidir An ft — Hydro pen iodide, or hydrioclic aeid, is a heavy 
eolorlow* giu*. A scdution of it in water may be made by passing 
hydrr^pen sulphide into wal^r in whieh i<Khne is suBpended, the 
rhief reaetion heinp :—H^ -f I, = 8 + 2HI. Sfr the analopoun 
restrtion for HBt, \k 2tM. 

Hydri^Mlie aeid may also be prejjftred by plaeinp twenty part« 
of iodine and two of watiT in a retort, the neek of whieh points 
upwanl and the eu<l id' the neek of whieh is eonne<'ted hy a plai*a 
tiilw^ with a bottle or other veKsid eonlaininp a little water. Into 
the tu but tire of the retort there is passed (at first a drop at a time) 

* tcNline forms diiTorently eolorrd nolutjons wUli cJi fie rent solvealM: i*jy. 
the ««jlutio« iu vvjitrr, Mif'ftliril, I'ther, nr Aqueous solution uf pxiUisfiiuiu 
iodldf In hrnwn, while the sohitioii io chlfiroform, iK'tisene, or carbon 
dinulpliidt*, \n vimI**! 






260 



THE ACID RADICALS, 



a mixture of one part of reii |)bwiilniniH with two of water. 
Abuiidiitiee of hydrioclk- acid is evolved nii the gentle appl legion 
of* heat^ and dljtsiilvei* in the water in Xhv reeeiver. Phoaphoric 
aeid remains,— 1\ t- 101, -i- HUljO = 20H1 ^ ^^^I'O^- Stt 
analc*gous reaction ioT HBr, }k 25<>, 

The offiL'ial aeid (Aeuium Ilydnodlcum IHinfum) is prepiire*! by 
the action of tiirtitrie acid^ in dilute ale<7hoiic Hokition, on ftoUift- 
siuin iodide in pres<uiee of a mniiU quinility of [»r»tit*'*iuni hyjxj- 
ph(»f*|>hite, the aleoiiol Mng 8ubHM>jpieiitly removed. The fnnetion 
of the hyiKJphoHphite is to prevent the Uberation of iodine throtigh 
oxidation id" part of the hydriodic iieid, 

S;/nipm Ariili Hydriodwi, U. 8. P., contains abtmt 1 percent. 
of hydrogen iodide. 

Potmmifii Imiiik^ Kl, is largely uwed in medicine, and is a con* 
venicnt salt on which to experiment in studying the reactions of 
iodides. 

Nitrofien Iodide h formed when excess of aqueous ammonia is 
added to a solution of iodine in potassium iodide. 



4 



Analyticui Reactions of Iodides, 

L To a few drope of an aquet>us solutiou of an iodide (e.^, 
KI) add i^olutioti of silver nitrate ; a pale yellow precipitate 
of silver iodide, Agl, is protlueed. Pour awiiy the suj^eroatant 
liquid, and treat the preci]dtate with nitric ari<J; it is not dis^' 
gr>lved. Pour away the acid, and then add ammonia water; 
the prcHMpitate is almost unchanged. 

2. Lihenite iodine from an iodide by the cautious addition 
of chlorine water, then a^ld j^tareh mucilage; a deejvblue com* 
hinntion ofiodine and starch, termed *S*tan'h iixlide/' is formed. 

This reaction is very delicate and eharaeteristie. Heat dei^ora- 
poses the blue compound, Exce* of chlorine must be avoided, or a 
solution of iodic acid will be prtKineed, which isccdorleas. Nitrotis 
aeid, or a nitrite aciduhited with sulphuric acid, may be used instead 
of chhirine. I Vm cent rated snlphuric acid also I i Iterates iodine 
from iodides, the hydrogen of the hydriodic acid first pnHiured 
uniting with the oxygen of the sutjthuric a<'id whereby the bitter 
is re<iueed to sulphurous anhydride, or even to hydrogen aiil* 
phide. 

In te,«ting bromini' for the presence of iodine, the brfiniine muBt 
^^e nearly all cnn verted into hydrobromic acid by means of dilute 
Bohition of sulphun»us acid (turr p. 258, Scott* ^ pro<*t*8s) or be nearly 
removed hy addition of »«Klium hydroxide^ before the siaivh of 
mucilage is added, 

OzofifiO^y — Papers soaked in starch mucilafre r(»ntiiining potas- 
sium iodide form a tcnjt for free chlorine and nitrous acid, and are 



I 





I 



IODIDES. 



261 



also employed by mcteorcilo|ristrt to detect an allotnijjic atnl very 
active fomi *if oxygen, tt^Jiied liy Sc;h«'ujlHiu ozone {iTum hCu, o2i\ 
I smell), whieh also liberates iodine tVorii jK>ta*Hsiurii iodide vvitb 
fornmlion of stareb iiKlide. t_)zone is fTiijij)u,sed to m:vnr uornmlly 
in tbe atmosphere, the stdubrily or iiisiilubrity of which in auhl to 
be dependent to sume extt*iit on it.s pre,s<:-]n.'e or al^sence. The 
pojit*ible iweurrence in the jiir of nitrons (*r other oxidizing gawes* 
(tts well im ozone) renders tbe nUireb iesi untrnstvvoriby. Jlon/eau 
proposed to test for o/nne by <-xposing Ulinn.H-papcr of a nentral 
lint i^xtked in u dihile ^dntion of |ic»t4issinai iodide : the alkali .^-t 
Tree by the aelion of tbe o/jnie tnrns the pa]>er blue. The siiine 
paper without iodide would indieate the extent towbieb tbe elfeet 
might be due to ammonia. Ozone, or rather, oztaiized air, i.H jjro- 
dueed artifieially in large quantities by parking air thruugli a box 
^lieane'ii Oxtine geuerator) in wbirh it is exposrd to the i^ilent 
eleelrieal disebiirge. In tbe latter operati(»n condensation of tbe 
volume of air, or rattier, uf the oxygen in the air, occurs, Ozmie 
is also prtxlueed in Mnjall quantity whrn jibospbi»rTis undergoes 
slow oxidation in moi>^t air. Home hydrogen peroxitle and itmnio- 
niura nitrate being formed at tbe same time* Ozime is a powerful 
bleaching, dir^infeeting ajid oxidizing agent ; it is very spiiringly 
Muluble in water, but s<iluble in oils id'turpentine and cinnamon, 
and in wime other liquids. Ha odor ia ebarcteri«tic. Frojn cx|»eri- 
ment»t that have been made by 8oret on tbe spccilie gravity of 
ojfione, its molecular formula seems to be O^, that of ordinary oxy* 
gen being O,. 

3, To a nentral ai|oei>UH solutiou of an iodide add as<du- 
tiou Cain tain tug one part of eupric sulpbate ami two an<l a Imlf 
|mrt8 of ferrous sulphate, ami well shake ; a dirty-white pre- 
cipitate of cuprous iotlide, Cul, is iiroihree^l. 

2KI + 2Cu80^ + 2Fe80, ^ 2CuI + K.^S<\ + Fe/80J, 

Or lo the liqtiid containing an iiniide add i^dution of cupric 
!»ulphat« and some solution of sulpburoya acid, and warm the 
mixture ; cuprous iodide is again produced. 

2KI + 2CuSO,+ H,80,-( Hp — 2CuI + 2KHS()^+ H^SO, 

Sppnration of CHioriiie^, Brotaidrji^ and hdhkn. — Thloridt^w and 
ides are ikK pret-ipitateil by curf^rir suli>hate ; the al>ove 
iion in ufleful, thiTefore, hi removing irKline frotn a H<4ntion 
in which chlorides and liromidej^ may alj«o he present. The totid 
removal of icwline liy the formtT «tf the two modificatitins of tbe 
[in-K^fM h ensured by following up the addition of tbe curprir athl 
fi*rrouii wilphatc« by adding a few drops of solution of poUL^siiim 
w Modium hydroxide, any acid wbieh might retain cuprous iotlide 





3 




262 



THE ACTD RADICALS. 



in solution being thereby neutralixetl ; ferric ur ferrous hydroxidep 
preti pi tilted at the ftnine time, mA jitJectiug the reuetJou. tk'ca- 
eionally, too, it may be neeesi^ary to repeat the prmTMj* with the 
filtrate beibre tiie bu^t traocn of iinliue are removed, Tbe MH'ond 
nuKbtication ot tbe proeess i«, on the wliule, to lie i>referrtHJ. 

IftrtsTefd. — (If nitrate!?, elibiralcs bnimiites, or iodater^iire prt*s- 
eut, it ia nece^ssiiry to fnsi> the sul>stauee with ii little t4<Klim!i car- 
bonate and cbareoal to reduce tbem. If the chlorine, brcjuiine, iiud 
iodine, are united with isil ver, it in best to fuse with n^Mlium ejirlw>uale 
and extract with water, aitboiigb with iodine and brtxiniiie tbi» i» not 
ab>«:*lntely nece!*8;iry.) The ^iibstain^e is pbiced In tbe rtask Khown 
in tbe fi^nire given in tbe fioction on the (juiintitiitive analysis of 
manganese oxide {nee Index), with wmie water and a few drops of 
Bcdutifjn uf lerric sulphate. Into tin* bulf>» a few drops of dilute 
starch niueihi^e are poured. Tbe bulbs are kept cold l*y immer- 
t*injj in water in a beaker. The contents of the Ha^k are then 
baled, and if iodine in j)n*i*ont the HUircb is colored blue. This 
test m extreaiely delicate. If iodine is iVuind, tbe eork and the 
bulb tube jtre removed^ and the s<»lulion boib^d until, on testing 
Again in tbe v^mxe way, no more icMline k tVaiml. If much iodine 
la [»re?ient, it lt>. necessary to add nmre ferric >«ulphate solution. 
The bulb tube is now cleaned, cbargnl with a few drops* of water 
and a droji or two of clilorof«»rui, and a verv" small cr\"stai of 
potiusHinui pernian^aiuite is added tu the sniution in the tiask. 
The contents of the Himk are bulled aj^ain, and if bromine ia 
prestMit the chloroform becomes rnl. The tul>e is nuw re mo vet! , 
and ninre pt>tas.sianj pcrmani^a utile and ferric sulphate addeil little 
by littk\ the mixture beiuij lx»iled between ea<di additirai until 
the bmmine has all been driven olf. A few dnips of alc«djol are 
iiddtil to tbe contents of the fltLNh to decoh^ri'/e any excesii of per- 
niangauate^ aral, alter filtratton, chlorine is* t4?»ted for in the lilt nite 
by means of silver nitrate. 

DHi'Hum of f* It /or id t' hi prrfu^.nrf^ of Bromiiff or fndule or 
Mh, — To a nnml! tjuaiitity of the mixed sol ul ion add e-xeesa 
«)f silver nitrate in j^resenoe of nitric acid, aufi wash the pre- 
cipitate once or twic"*? with wafer hy decjintution. Then jxnir 
ui>on the precipitate 1 Cc. of a very dilute solution of jK»tn*- 
sinm iodide (1 part in 1000 of water), add a \*i:^\v dro|w« of 
dilute nitric aeid, albiw to stutul in the ctdd for an hour with 
oeca,sional jsbakiuij, and filter. Divide tbe >tf!trate into two 
|)art8t aufl add silver nitrate to one |)art and a drop of dihited 
cldorine water to the other. If tbe silver nitrate produee** a 
u'/ii/j? precipitiUe ^ and the chlorine does not liberate eithex 

* Silver iijtmti^ produtM^ a precipitate in miy i^u^o, which may con- 
ftlst of jiitvi^r eUlorule, broniido, tir ioclido and may, ttioreforc, be jnm 
white, .vcllowish, or vellow. 




IODIDES. 



263 



bromine or iodine, then the original precipitate coutaiut^cl biI- 
ver cb!ori*le. 

The action of the pola&iium imlide on the silver ehloride is repre- 
aetited by the etiiiution :^AgCl 4- KI — Agl + KUl. IX there is 
en*»u>rh wilver I'libmde present in Llit; ongiiuil pivi-ipitate, all ihe 
ttdiiect potiL.<-^iuni iodide ^ eonvt-rted ijiiu jMitiLstiinm ehloride and 
it is thi* latter which gives the while [irecipitjite nil tlje addition 
of silver nitrate. 11 the ebh^rine wiiLtr liherates hminiiie or iodine, 
thiH nhows (when nijt Tiuirf the 1 i\\ of the ) in lOUO potjissinjii 
iodide hits lK*en used I that diHtineliy b'ss thriii 1 inilligrsnnine i»f 
nil VtT ehloride, wtfl pfobnUy tinnrat *tif^ wws present. 

Chloride^s nu'iy aUo be deteeted in prenenee ttf bronndes and 
iodide-^ by titkiiig advantage rd (be b»rnialioa of ililoroebnuijie 
anhydride (p. l^Jlt) and tke inm-oeeurrenee of eurrespmnding eoni- 
pounds of bromine or iodine, as folbdvs: — 

To a mihition of a mixture of iin iiMiide with a bromide uikI 
a chloride add a concentrnted solution of 8odi inn .^nlpibite, then 
a reagent pre|>ared by nnxing equal vohiniei*of sniphuric acid 
and saturated stdntion of eupric !?yljjhnte, until no further [>re- 
eipitation of cuprous?! iodide mvurs. Next add solution ssotlium 
bytlrt>xide to remove the excensof eo|i|M'r, hlter^ and eviqjoi*ate 
to dryueis^* Transfer the dried re^idne, together with an equal 
hulkof |X)taSijiiim duhromate, to a dry test-tube titttHl with a 
delivery-tube, or to a snntll returt, uudeover the mixture with 
Bulpliuric acid. Dintil into water. (Iiromic anhydrith^ and 
hydrochloric anti bydrcd^romic acid.* are liberated by the sul- 
phuric acid, and intenieting with one another, form chlorf> 
chromic anhydride^ together with free bromine and chlorine, 

(VC\ -f 211(1 (><\Cl, -h Up 
2(:rO,-f BHBr4 3H,S()^ . Cr,(SO,\ | ;Uir, + 6H/3 
2CrO, + 6HC 1 + 3H,SO^ ^ CV,{80,), + ZV\\ ^ tiM^O 

The rhlonwdiroTnie anhydride is deeornponed by the exeess of 
water into whieb it di.stils, giving rise to anhydroebroniie aeiil, 
which impart!? it^ orange color ti> the liquid, and hvdrm-hlorie 
«eid, tfuH: :fOr(>,CL f 'iH,0 = H/XO, « 4HC1. fhedilorine 
whieh IK pnxJneetl in the rcaelion e!^'ap*^s, and the hr<»nune \^ dis- 
«cilvtHl t>y water The eoloreii liquid is then shaken witls ehloro- 
form, whieh remove** the bniminv, indicating bromifleH in the 
ori^rinal «ubHt;ince ; a yelbjw or orange eolor remaining im due to 
nnhydnK'hromk' aeid, indicatitig chlorides in theorgina! subst^ince. 
Or arnmonia may he adder! to tlic diritdlate ; the eolor due to 
liromim* \^ tliprehy entirely reuu>ve4J, while the yelhiw eo!or of 
ammonium ehroanite reniainn. 



J 



264 



THE AC! I) RADICALS, 



IiiHt<?ad (»f el im in 11 ting thu iotiiiie as cuprous iodide, it may 
expelled in viijxir (oln iiuiji en<>ugli l\v il^ eidor and fMlur) liy tuning 
the dry mixture id' the silts with exeens of [>o\vderetl potasH^iuiii 
tJit*hrorniite. The residue, hroken into j^nudl fra^^njents, miiy tlien 
he dirttille^l with sulphuric aeid tbr the deteetiun of the hr<mdne 
und ehlorine. 

5K,Cr,f), + OKI :^ 8K,CrO, -f- Cr,0, ^ 31, 

4. loci ides have been sln>wn to I>e useful in teMin^ for mer- 
curic Halts (j<^ff the Mercury reactions, p. 21H ); fi niereurii* salt 
(corrosive sublimate, for example ) may therefore^ be uaeil in 
testing for i slides, a scarlet precipitate of mercuric iodide, 
Hgl., iieing producecL 

ThiH reaction nmy Ik? employed where coaiparatively large 
f]muititiL*?^ of an iodide are present ; but \U UM^fubiess in aaalysis 
irt limited by the faet that the prfcipitjite is jwduhkMii excea* of 
the diM>M')lved tndide, or in excess td* the mt-rearic t^olutiou. The 
color of the precipitate and it-s in»»lnl>i[ity in water distinguish it 
from mercuric chloride, bromide, and cyajiide, which are white 
^Juble salt«. 

5. Iodides have ali^o been nbowa to be useful in testing for 
lead salts (seethe Lead reiietioti.^ p. 224); similarly a* lead 
salt (acetate, for example) may be iim^<\ in te^stiug^ for iodides 
iu »olytion« which are either neutral or faintly acid with acetic 
acid, a yellow precipitate <d" lead iodide, Pbl^, mlulde in hot 
w^ater atid crystallizing in yellow Bcales on cooling, being 
produced. 

X^ead chloride, brondde, and cyanide are white; hence the above 
reaetioa may (Kx^aMionally be useful in distinguishing iodidrs 
from chlorides, hr^iniidc'S or cyanides*. Hut h-ml iodide ih f^lightly 
*M>luhle in eold wati^r; hi' nee small (piantitio^ id* indidcM cannot lie 
dt'tetted by mean,** ofthi?* reaetion. (For bNlatis, Mrr \i, 2H0), 

AnnifMfu'Jt htfivefn i%ktnnt^ Bromine, Iodine and their (hm' 
pound*. — These elements form a natural group or family, the 
meiaher^ of which are ehwely relati d and exhihit a diHlinet gra- 
dation in phj'^ical properties. Thus rhlurine is a tras and iodine 
a fwOid, while brranim' t>ceupie.*< thi^ intermediate litpiitl eonditicm. 
The atfjmie weight of hrfHiMne is inarly midway ht^lwem those of 
ehlorine and itKline. The K|>»H'itie gravity of litpiid chhirine ii» 
L38, of iodine 4.9-'», while that of bnnnine is nearly 3, Liquid 
ehlorine is transparent, it>dine opa<|Ue, broaiine intermediate. 
The crystalline forms of tlie chlori<le. t »rfi in ide and iodide of the 
mime metid arc eonimonly identical. One v(»lume of either element 
in the gaHe*ms state combines with an e<pial V(»lume of hydrogen 




CYANIDES, 265 

(at the same temperature and pressure) to i"i>rai two volumes of a 
gasL'MUSiifiil, very stilubk^ ia water (hydrochlnric add, liydridjriHiiic 
iii!id^ liydri<jdie tuid)* By ibHr ujjion with metjils, chlorine, 
bniiuiae, and iiMliue loriii Halt'* id' which Hodium chloriUi^ broaiide 
aijil hnlide may betaken as types. On this nccoiint they have been 
called I he hatiMjenn (/.<-., Halt {^rodiieers), and the i^i\i^ are called 
haloid »alU (from ai^, Uulut iiea-tialt, and eiAni, rdim, likeness). 



QUESTIONS AND EXEHCTSES. 

Bt&te tijc method by whic?h broaiiae is obtaiaed from ha niituml f om- 
poandd. — Mijntton tli« |iro|HTti£"a of brtmiiui?. — How uiay pota-s^ium and 
auimoniam brum ides bi; iiiud*^V — By wliat rt^agt'ivU may F>rumi4ofi be <Hh- 
Unguished fnim chluritles? — Wbeiice is mkII uci obtained ?—Ily what pra- 
Cf!» i« iodine ifKiIated'f— State Ibi^ proiRTtii'sof iiidbiu. — What iatbe nataro 
of iwlplnir ioflidey— (»iv« the aiialytif-al Tt^uftions of iodides.— Wlmt three 
fiabstaiiCLJi may, iudirt'etly, be dtteetitl by a mixtiirf: of potas-siam itnlide 
ami starch aiacibigi^ ? — Def^Tibe two uiethridB by whiidi iodides may be 
removed from a floiution contaiamg eblorides and bramidea. 



HYDROCYANIC ACID, HCN, AHD OTHER CYA30DES. 

The acid radienl of hydrocyanie aeid and olher cyaiiidL*** is a 
campound |i^r*mp, the cyanogen radical, CN, {or Hlmrtly, t\)» Jt 
i» Ko named iVom umiiK:, kmuton^ blui^, and niinuty ijtnHno, I gener- 
ate, in alluition to itM prominent chemical character Uit forming, 
with certain iron eunjpftunds, the ditTerent varieticji of I'ruKsiaii 
blue. It was from PrUKsian bhie that Hcheelc, in 1782^ first 
obtained what we nuw, from our knowledge of \i^ ennipo»ition^ 
call hydriH'yanic acid, HUN or HCy, also called pni>«ic acid* 
Cyanogen, OjN,, wa« i8cdated by Oay-Lusnac in 1814, and wa;* the 
first compound radical distinctly prove<l to exist. 

.S*rt/tvyjr, etr. — Certain com|Mmmlj+ containing the cyanogen radi- 
cal orr*ur in nature, and others can easily be |ireipared» Ainniii- 
nitim cyanide in found in snudl «juiintities among the gasi's^ <d' iron 
fiirnacc*!H, and is produrtnl to a nlight extent in distilling coal for 
gas. In th«^ prefKinition of jKitasshini ferr^jcyanide the cyanogen 
nidical is forme*! abundantly by heating animal refuse conljiining 
nitrogen, such ant be scrapings of horns, hoofs, ami hideM(r» jiartH)^ 
with crude potasj<iiirii carlHinnte |:i parts) and waste iron (tilings, 
eU\) in a eovered iron jiot, Tlie resifluitl mii«*, wliich con taint* 
potitssium cyanide, hut nri f<'rrocyanide, is hoile<l witb water, the 
mixtim* tilttTcd. and the filtnttc evaporated and si^t a.si<le for cry»- 
taiU of terr(»cyanide to !V*rm. The cyanogen, produ^-eil from the 
carl>on and nitrogen of the aninad matter, unites with tl*e p^da8- 



260 



THE ACID RADICALS. 



fiiuiii t4) torm jn>Ui.ssiuiji tyiinide iiiul tbis afterwaril, on boiling 
with wtttirr, inltrMtts with iron sul|ibMl*^ (|»nMhiL*tMi by the iiiter- 
aftion of the iron with snljthur occurrijig in the iiitrogeiioua 
r>r^inic ijuittt'i>, and its t^ulphiite in the crmii' |[M)tii^iuin v^r- 
bonati') to (urm what i.s utU-u termed yellow ])ru**»iate uf j»ot- 
ll»h, Potiijwiuiii Ferroeyunidt', PottjAii I''i'nuetffutidum^ U. 8- J\, 
K,Fer^,Ng3H,0, H cmnjMjund ocrurrijig in lour-^ided tidiuhir yel* 
km* ervHtula, Tliin N*h mntiiins the elements of eviinogi/n ; yet \s nut 
a eviinide, but ii ierroLyjtnide. It is not |»ois<»nouf^, fiml in other- 
wise dilierent from eyiiiiides ; it will be furtber noticed suiiKtiuently. 
Frt)m this^ siilt all eyunides are dircnlly or indireelly prepared. 

fhffijiftitfm tytittifir^ KCN or K(\\ tlie eonimonest eyanide, may 
he obtained by heatini^ p(*tas&*iuni ferrwyanide Ui redness until 
gits (tbieily nitroj^en) Ih no longer evolved iind iron earbide i^^ttle^ 
to the l»ottom of the molten iiiiisw ot almost joire eyanide. The 
produet, carefully [j<aired ot!' and eoobti, h >m opat|ue rr>'i*talline 
mjL'*.^ /V#/riW/ (Sjcmiiium^ U. H» I*., rtmtaining alamt 9r> pereent, 
of jiotiiiwium eyiinide. It may alsfi lie pnKlnri'd by lusinif ei)Ldjl 
partf* (d* potassium ferrouyanide with three* of jxitasc^ium carbonate 
iit a crncihle; earbrmic anhydride iw evolved, ir«in in 8et fret% and 
liota***<ium eyanate, KCNO, is lornied^ a*» well i\& p6tas?«inm 
cyanide:— 

*^»^*'*V^6 + K/X),^ 5KCN 4 KUNO f Fe f CO, 
Mt'tnirie etjnti'hfi^ is produced in erystidw by distil ving 1 port of 
potaf^inni ferroeyanide in l'> parts* of Im filing water, adding 2 partft 
rd' mercuric sul]diate, ki^^ping the whr»le hot lor leu l4> tit1l<M*ii 
minuter, and then tillerinir and »ettin|f awidc to emil. Besides 
mercuric cyanide, Hx(('X),, ferric sulphate and |*otaji>tviunj *u)pU- 
ate art^ formed^ and niereury is* set free. Any excess of fernR'yim- 
ide jrivej^ Prussian blue by interaction with the ferric sulphate. 

Mercuric cyanide is exceptional in j^ome (d \\» analytical reac- 
tions, both art a mercuric Malt and m a cyanide. Thu» it.s solution 
diH^K not jrive any pre<'ipitate with potiLssium iodide, {^rr reaction 
1 of Mercuric ^altH, p. 21 H) unless? a drop (ifliydrcjcblriricaeitnuw 
previously h«*eu added ; neither does it yield tlie usual yellow and 
white jirecipitiitC!^ with pf»ta.s*4ium hydroxide and with uuunonia 
water R'flpectively. Similarly it doe^ not give the silver nilrnle 
reaction for cyanides {*et reaction 1, p. 228), 

fSjfimffftt, C^N,, may be is^olated by heatinp mercuric cyanide, 
Hjarl ('>'),♦ or mlver cyanide^ A|K^N. A small flame of cyanogen 
may he obtained by heating a few erystida of mercuric cyanide in 
a short jdece of frhirts tubinjf cIo^hI al one end, and applyinij a 
lijpht to the other end as nimju aw evolution of gnu ciiinnienei*s* ; 
hr»)wn fHinwffiutmp'n (< *N)„» and mereurj- are aho produced, hi 
the cane of silver eynnicle inetiillic silver remjiiiLs, (*yan<»p'en i» 
A ecdorless pw which burns with a iK^nutiful jieach-bliwM^jm colored 
(iarne. 



CYANIDES. 



267 



Diluted Hydrocyanic Acid* 

Experiment.— DisHtilve 2 or 3 i^rain:^ of jmtiiSi^mm ferro- 
cyauiile io 5 ur limes its weiji^lit uf wnU^r in u te?^t4iihe» mid 
a few flropes of i>iil|4Mirir acid nmi hoil the mixture, cuaveyiiig 
the evolvetl giu^ ihrough a Item gliLss tulie (uilapteil u* the te«t- 
tulje by tueim.H of a c<jrk) into atiutlier terst-tuhe etiulaiuiiijjj a 
little water; the priMiuet m a dilute solution of tiydrocyanic 
acid. Theollieial s^olutiou, Acidnm Ilt/dntcijanieuin JyUtdti/nt 
is prepjired by iiiteractiou of silver eyaiude and dilute liydro- 
clilorir ai'id. It is a colorleH« liquid with a eharaeleristic 
odor and is excecHiin^yly jxnsououy. It coutaius 2 p^rreiit, by 
W€4;j:bl of hydrogen cyanide, IICN, 

2K,FeC,N, t Bfi.BO, = FeK,FeC,N, + 6KHSO, + OHCK 

To prepjire ft larger quantity ()rfM'e«»d an follows, carry iag out 
the operatioa ia a w«'Il ventiltitcd fmuc-njphoiinl : — Dissolve 2\ 
ouui'cs* of putiL^siuin lerrocyaaifli* in Hi (juir'ch at' water, aiUl one 
tlui<l ounce of .sulphuric acid [ireviiKmly diint<'d with 4 ounct\s fif 
water und crxdinl. Put the ^wihitioti intij a Hask i^r <>lliL*r suitable 
appwrntui* of glussor i*arthenwiirc| to which ijre attachc^l a conden- 
!«er and a receiver arntagcd for di^^tillutioa (nee p, l'M\) ; and 
havinir |ait 8 oanct^H <if rtiHtilliMl wiittr iatu thf receiver, atnl pro- 
vided eftitirat lacan^ f'nr keeping thr» eondenst'r and receiver cold, 
apply heat to the fla.'^k, antil by slow diHtillatiua the liipiid in the 
receiver ii* increaned to 17 Huid DuncesJ Ailrl to this ,S (Uiaec,** ol' 
dietiUed water, or a^ unu-h a?< may be Mulhcient to brin^' the acid 
to the requirc^i coneentratioa. The end of the coaileuisi'r, or an 
attjiched tabe, nhould pusA tpiite iato the riMciver. 

ThL' rt'sidue from this rcartiun U iicicl pi^laxsinni sulphate, 
KHSO^» which reaniins in solutioa, nnd p<ita>Jrtinm iVrrous iVrio- 
eyanide, FeKjFd'^N' an inHoliihlc (towiler somelijmw tirinrd 
EveriU^a i*aU, from tht- aanu^ *if tht' ehendst wlio fir!*t made nut 
the nature of the inlcractina. Tla- lnlt»T toaipouml Imhihucs hhii-^h 
green during the oiH-nition, owintr to ahsorption of oxyjren. 

Purf aHhijdtmiM hijfirnfyrinii* an'ti U a «'olorlej*.^, hi|rh|y voUilile, 
intt^UEtety poiKonouK liquid, solidifyinjr when conled to a low tf^ni- 
peniture. It may he imade by j)ii.'wiag hyr|ro«ren sulfdiidi- over 
jwrcuric eyanide. The otTieiaJ solution of'the acifl in niodenitely 

ible, but IM ftjiid to Ih> rendt^red more swi by the jiresence of a 
tninute trace of sulphurir or hydrochloric aci«L A more concen* 

^ TbtR oiiemtioii i^ pc< nliiirly lliihle to thtm^ STidd^u and tanndttioug 
evoliktion.^ (if vii|>f>r, or *1>nmpnijf/' whkh oftrii lottTfen- witli wu rcsMttil 
dbtillHtian. Such bumptnj; may ii^imlly be (jrovr-Mtcd and (jni<'t<*lnillit joa 
miAUrerl by pl»riti»t in thr liquifl. btforo beKiioiiuti to lifat \U a few small 
ingmenU of uiiKlaxed (jartheuwarc, such xs tobiM*4:0'r>i|ie stem. 




268 



THE ACW MADICALS, 



trilled mid m liable t<i take up tlie eleineiitii of water and yield 
iiiiirnuniuni trininite, NHjJlHt^. Siiuti<_»ns of bydroeyuiiic iicid 
iiCtcii lu'cimie bniwii by ftiriualioti uJ wbiil Ls, uj>|mreiilly, parncif- 
attmjen, (CN)^. Afeordiiig t/i Williams, aqut^vu^ kyUrotyaiiic 
aoid cotiLaiiiing 20 |torceDt. ui' glyferiii ciiii be kf|it Jor an abmmt 
indi'tiiiit*.^ lerigtb of lime. The oUieial Ufid sbould bf preserved 
ill weU-?itiijipt*rfd iKfttbs tied over witb im[M:Tvi«jiLs tis,HiK« and 
kept inverteti, wbeu not in «se, in a eool durk plaee. riiU'?vs,siH-h 
jtreeaii linns are adi»|>ted, the snlnlion rapidly t>ecc«nejj less eonceu- 
traled by estjipe uf ga.^nms bydrocyanie aeid. 

Hydn^eyanie aeid iUjmj oceurn in cberr^-laurel water and bitter- 
almond wat<'r. ^ 

The nK'tbod.H of detennining tbe eoiieentralion of hydrocyanic 
aei<l HolutionK will be given in tbe elnipter on volumetrie and 
graviuietrie f|uantiL[ilive mialyj^H^ The vtilnmetrie rnetbcMJ in 
based rm tbe formation of silver cyanide and its wduhility in 
solution <d' alkali-metal cyanides, ilh described in reaction I, below, 
Tbe hydnx'yanicaeid nsi d in phaniiacy is extremely lialde tiJ varia- 
tion in strength, [t Kbould freciuentty be tested voluuietricjilly. 



Anahjiieal Reuctlons of Cyanide, 

1. To a few dro|i« of tlve hyt]ro<-yanic acid wdution pro- 
duceil ill tlie tbrei^oitig ex)>erinient» or to a e<jlutiou of any 
eyfiuide (except merciirie cyanide), add excess uf Rdutiou of 
mlver uitnittj; a white precipitate of i^ilver cyanide^ Ag<l'N, 
( Afffeidi Ciffitiidum, I . K F, ), m prcMlnced. When the preci[)i- 
tiite buif snl»eided, ponr away tbt^ wii|i€nmlaiit licjuid and place 
luilf of the residue iu another tejst-tuh**: to one pniion told 
uitrie acid, aud iM>hce t!ait the |>recipitate doe?^ not dissolve ; 
to the otiier add amruonia water, and observe tluit tbe pre*_*i[>i- 
tate, tbioig^h Rdtihle. disi*i>lve.s i4<»rncwbat slowly. (Hilver 
ebloride^ whinh is al^i while, ik rearlily R>luKle in ammonia,) 
iSilver cyanide ili^ssidves in Solutions of cyanides of^ alkali- 
mctalfe, scduble doublecyaiades being ftirmedf p.^;., KCN, Ag< *N, 
or K Ag(CN )^). Silver cyanides alm> tlitwolves in hot concen- 
trated nitric acid. 

SoliibifUij of preeipiitttfft in ronrenfroMi itohfiowt of mlt». — Silver 
cynnide and many other j precipitates* insoluble in acids (or in 
alkalies) are often wduble in the Kaline litpiids formed by the ad- 
dition of acids and alkalies to each other. Hence the prccantion of 
adding the latter reagents \x\ separate portions of a prfK'ipiiate 

* Tmees nrv forme<l when an pUtiHc current TiMsea between earboa 
prili's ill fili^litly tiioht air (Dewur); alHti dnnaj; the action of ultn« or 
nitrous ftcifl on Rii^r. camniet or fia«^ly divided pharcouL 



CYAA'WIS. 



269 



^ 
^ 



KC"N + 


H,0 


FeC,N, + 


KJSO. 


K.FeC.N, 




12KCI -h 


Fe.(FeC.N.). 



when exajiiining its solubility, or of uot adding the one until the 
other hiy* been |K>urt-il away. 

llydrocyaniu acid ami other cyanidps may 1m? detcrtf d in the prt^s- 
enc<' of j»otiis.siiini ftrrouyiinide by disiiljinir with ii large excess of 
miclium bituirlKinate ami te.sting the distillate tor liydrncyauic aeid. 
Ill the case of mercuric cyanide it is nect?i<.Mry to add a little 
hydrogen sulphide. 

2. To a dilute solution of hydrocyanic aeirl, or of a soluble 
cyanide (excBi^it mercuric cyanide ), a<ld a few ilrops eaeh of 
solutions of a ferrous and of a ferric mlt (ferrous sul[)hale 
and ferric chloride); to the mixture add [>otai*i<ium or Kodiuin 
hydn>xide, magne,«ia, or s*i<Iiuin carlmnale, and tlieii exc(\«8 
of hydroi'hloric acid ; a precipitate of Prujisiaa blue reuuiins. 
The decom|>o8itions may be traced in the followin^'^ equations : — 

HON + KOH - 
2KCN + FeSO = 
4KCN + FeC.N, = 
3K^FeC;N,+ 4FeCn, = 

The test depcadsi on the converHion of the cyanogen radical of 
the cyanide into ferrricyanogen by aid of the iron of a ferrouHfc«aU, 
and the conibinalion of the ferroeyiiUfigeii, si> prrHlurtHl, with the 
iron of a ferric nail. 

3. To a solution of hydrocyanic acid add ammonia water 
and yellow ammonium hydro^ulpbidct and evaporate the 
liquid nearly or quite to drjmeas in a small dii*h, occasiounlly 
aihlinj^' ammonia till the excens of amnion iuiii hydro^^ulphide is 
deeonipoped; add water and a<idiilate the lif[uitl wilb hydro 
chloric acid, and then add a drop of solntit)n of a ferric salt; 
a idoo«l-re<l R^lution of ferric thiocyanate will he formed. 

Tills h A very delicate reaction. Some free f^ol[>iiar in the 
J^llow ammonium hYdrosul[dii<le unites with the alkali-metal 
ejanide and form^ ihtoJyanate (NII,C*N I S = NH,S( :*N). If the 
liquid )uiM not been evajjoraled far encmgh, aimnonium hydro- 
e^ulphide may still be prest-ut, and j^ave bliR-k ferrous sulphide on 
the addition of the ferric salt^ hence the aeididation prior t<-i the 
addition of the ferric wilt. 

I[ijdrt*r*jiutir ri/»iV/ in the Mmd. — According U* Buchner^ the 
hl(M>d of aniinalft poisr»ned by hydrocyanic acid, in>*te4id of coagti- 
luting as usual, remaios lirpiid and id" a t lear cherry-rc<l color for 
several dayn. In mie cjl^^ he obtained the reactions of the acid *m 
diluting and iJistilling the bbxid tiftwii days aflber death, and 
applying the u^ual reagents to the distillate. Aiijueous w<dnti*m 
of hydro^n |K?njxide changes fucIi blood to a deep-brown color. 




270 



THE ACW EADICAIJS, 



tS(MtibeifiH ii'd lV>r hy<ir<H viinic iM id is said tf> he extremely 
dilicato. Fik<»r-pa(ier is i!«»:iked in a solution of '^ jmrt8 of 
^immrLiiii reHJii in IIKI of alcohoL A !<trip of tbiHtmper is dijipcnl 
in :i solution <»f 1 jinrt of rujirir Hiiljihiite in ntl of wat^'r; a little 
of tke suspeLtt^d scdntioij is plartHl tin tliin jmper and expiised 
to the air; tbi' pa[»t'r iiinnediiitfly turns liUu' if liydnK-yjinie arid 
Ih* ]»ri'.*4itMit. Or tho papier may l>i> plaivd over llie nioulii of hii 
ojicn bottle of medicine sup[»ys*'d to i-ontnin liydniiyanit' aeid, or 
imiv be otherwirte ex|M*.si'd Ut the vapor of ii suspertt'd liijuirL 

Aiititloh\ — A mixture <d* ferrous sulphatt% soluti<ni i>f ferrit; 
I bloride, and either ma^m^ia or so«tium earhonate is the recc»g- 
ni?A*d (iiituhie in eiwes of poisojiing hy liydroeyanie acid i>r potais- 
Kiu.n eyanide. In >(neh an alkabne mixture the jHiiwmous ryanide, 
by interaetion with lernms liydroxiite, is at onee eoiivertt^J into 
innoenous potassium or other ferroeyanidf: should the mixUire 
bet-onie aeiil, tlie ferrie s;ilt prt^sent intt^raeUs with th<L^ twihihie 
ferro^ymudi" f<>rnaH«,^ inf^tluhle l^russian l>lue which is alj*> inert. 
From the rapidity of the aetion of these poi«onHj however^ thei\' is 
seldom time to prejiare an antidote. Emetics, the stonmeh-pun»p, 
or st<*maeh-si(>hnm thr app]ie:itifm rd' a stream of eold water to 
the spine, aiid tbe aLhove antidote, form the utjuul tre^itmenL 



QUt-STlONS AND EXERCISES. 

Writ<? a pnmffraph on thf* discovery of liydrm'yanic acid anrl of cyano- 
grni.— Mt^iitiou the smipew of the fvanogua of «^yauid*-vs.— How is |toU^s- 
itim fvrrfucyaoiilt* prefMirtHl? What is tho foniiiila of fiotUA'^iniu ferro* 
I'-yaoifJe? — Is potiLssiuui furroryanidc |ioisf>injii3 ? — Write an equatian 
expressivi^ of thi.^ rtwtioii winch eusiiei* when i^ru^ssimn ferrofyanide and 
CArlHuuite sire lininght loKethor at a high t*^mpi*ratwre, — Whnt ar«i the 
prf^iierties of pyanogon ?— How may it bo obtained in a pure condition? 
^tltjw i-* mercurjc (■yaniclt? i»cr|Mirt+4 ? — What other wubstanccf* and second- 
ary prixlticts are furmiHl at tho sjiun' time?— How niiu-h hydnH-yanic 
!*eid Ih ("onttiined in the otficial Acuinm H^drneiftimcnnv IHlntum ,'^Give 
details of the preparation of hydrocyaine aeid, and an equation represent- 
tuii tho n-action.— Stiiti3 the proportion of water that miisthe addtMl to an 
uijitcotiH solution containing ]^ percent, of hydrocyanic ftcid to reduce 
I be ^tren^^th to 2 prrfent, Ann.^ *j'i to 1. — Wbat are the charaet4?TTs of pure 
nudilijted hydrocyanic af'id?— How may it beubtaiiied?— Emimerate the 
U'st for cyanides, pirini^ equations, — Explain thfi action of the bc^it anti- 
doU.* ill cases of poiiM>u]n^ by hydrcM ysmic mid or fHvtasi^iiini cyanide. 
Show how It acts in alkaline and acid anlutions respectively. 



NITRIC AOIB, HNO,, AND OTHER NITRATES. 

Sfntrrt.t. — Nitrogen pen«xide, N^O,, is formed U* Mune extent in 
the atinos|ih»'re by the eond/mation of nitrojjen and oxygen under 
tho iiiflueneeof lln^ jKiwerful eleelrienl di><ehnr^eM during thunder- 
stortTiK. This oxide undergoes further oxidation in prent^nee of 




NITRATES. 



271 



waU^f; and with amnioiiia, wlii*'l3 iw always n coiistiuient cif the 
atnioMphere, itl'nriiHaiiiiuoniuui iiitmU'. Tlu' nitrates tniiini in niin 
no lUiuljt originate fmrtiy or wholly hi thi» ni:innt'i\ Tlie fixidati<in 
i»f ammnnhi ami u( the iiitrogeiiouti r<)nstitiK'iit.s<>r iiniitiul and vege- 
tiible mailers in the ?wiilj tkvfired hy darkness )»y the presenre of c«l- 
ciutn earliunjiU'. and eis|>feially by the i>re>y.nH'e uf the nitrifying 
lirganiHins, rt'^ulta in the j)n>duelinii (if nitnik'?*. Henee nitrates 
are eoninjoiily met with in natural water>, and in snili* nnd the 
juiees u! phmts* In the coneentrated jdant jiiiees, trniied medi- 
einttl *'Kxtnieti*," t*mall prismatic erystaln t>f pMUuHsiuni nitrate 
in«y fHTiiAioually be iil)j*erv»Hl. (The eiildeal eryMals i4\v\\ niL-t 
with in extraetH are puta^isiuni thh^ride.) Nitric at'i<l and other 
nitmte» are prepan'd from potiissiuiii and midinni nitrate^^, whitii, 
in turn are ohtuinid from the Hurfaee hivi-rti of the wiil of tnipical 
euunlrie«i. i*oifi^iitm niirate (nr pfUninfic ntirr^ fnun the fiirm of 
it* rry»tiils)» iit prtxiueed in and alnait the vilhi^e^ iif Indiii. Tlie 
native^ s^imply *^cra|>e the ^urfaee of Wiii*t<» grounds, mud- heaps, 
biinki«f and otlier f<p<^Ls where a nliglit imTu«t4ition indicates the 
presence uf tt[»preeiabh^ ijuantities of nitre, mix the scrapitigs with 
wiK>d-af«bes, eontaiiiing potas^siuni enrbonat*' (t(^ deeoaipose the 
CJileium nitrate alwayss pn\sent), tbgrst the niixturit iii water^ and 
evaporate the Hrjui»r. The innnediate proihiet is purified by care- 
ful n-ervKtallizalions, ami is s<^nt into commerce in the forai of 
while cr\'»talline niaKsc's or fragments of striated six-sided prisms 
(/>»Amxo Xifraj^ IT. 8. P.). Ik^ides its use in ifiedicine, it is 
emph>yed in ver>^ hir^eipiantities in the iiiannfacture of gunpowder. 
Pot^iMMiUfu nitnite is alHo hirgely prepareiJ by the intenirtioH of 
potaHsium chloride and sodium nitrate, iSfHh'um A7Mi/r' occurs in 
depoKitM from *A incljcs to ^ yards in thickness on and nej«r the sur- 
face, and at any depth dowTi to jibfait '^0 feet, in many parts *>f 
Pern, Hfdivia, and Chili ^ but m<*re espceiidly in the district of 
Ataeaina. The iniuend is tcmied rfffUhf, and comnirmly rontaius 
50 prreent. of sf>dium nitrate. The bitter is dii*tinguii^hcil as fliUi 
imiifirtrf or Chili nitrr'^ i>r (from the form i>f its cr^'stals — obtuse 
HK»niJ»fdii'dni, not cubes) euhif ftifrr^ and is chietly used a^ a frrti- 
lizicr and as a source of nitric acid, its tendency to absorb nioisture 
iin^ttin}£ it fr»r use in guiqHivvder, In s<iTne parts of Fairoje 
tMitiiH^iuni nitrate is nia<le artificially hy ex[>osing heajisof animal 
manure, refns<^, /i^h<T^, and >*fjil to the aetifm of the air and the 
heat rtf the sun; in the cours<"of h year or two the nitrogen <H' the 
animrtl nmtler l>econicf< f)Xtc!ixcd to iii traits; the latter are rejuiived 
hy wa>*hing, According to Warington, the nitrifying fcnnent 
appears capable of existing hi t)irce londitions: (I) The nitric I'er* 
mcnt r»f sin), which convert both aminMnium stdts and nitrites 
intfi nitrates; (2) the altered fennont, which converts lynmoniuni 
wiltn int^i nitrites, but fails to change nitrites int^i nitrates ; ural 
(3) the nurfiu'e organism (a lMicteriiiin)» which changes nitrites into 
nitmteH. Bimilar nitrification goes on in well and river waters 



272 THE ACID RADICALS. 

containing nitrogenous organic con tarn i nations such ajs »ewage, 
whitli therein' teiul hv In iriniH* leK** noxious. 

Xfth', — The wtird liitrir is IVotn nitrr^ llie English equivalent nf 
the (ireek vt7f>oi' {uih-tm), juiaiiie ajiplieil t<i eertjiin Uiiturnl tlejM>{<it8 
III" natrtm (sodium enrl><inati*} tor which potassimu nitrnto *«*enjs wt 
tirst Ir* liiiVL* Iveen rniytaken. iSnlipdrc is sini()ly it<il pdrft% milt of 
llic rock, hi allusion t^i the natural origin of pota-saium nitrate. 
*Siti jiruntHa (from *<//, a salt, and pruna^ a live coal) is [loUnMinin 
nitrate Jiiclted over a fire and csist into cakes or bullets. 

The nitric radical iH univalcni {NOj'). 

Nitric Acid. 

Experiment — To a fragment of potassium or sodium nitrate 
iu a tej>tt-tube add a drop or two of Hnl|*liurir arid, and warm; 
vapor ijf nitric add, HNO^^, in evolved. The fiiuies may he 
condensed by pns8iti^^ them through a bent deiiverydube into 
a seeond test-tube which is kept cold. The delivery-tube 
iihould not be fitted to the Jir^*t tt^t-tnbe by roenm* of a cork as 
in the preparation i>f hy<lroi:hh>rie acid — he4'ayse the nitric 
acid va|i€rsi would strougly act on it^ — but by means of plngter- 
of*l*aris, a pai*te of which sets hard tm lieing ptit aside for a 
short time, am! is unaflK^led by the add. 

On a Runcwhat lar^i^er s<*ale, nitric acid may be prejiared 
by beatintr, in a stopptTcd n^lort, a mixture of erjua! weights 
of potassium idtrale and sulphuric acid; nitric acid distils over, 
and acid pota.ssium sul[diate remains: — 

KNO, + H,BO ^ HNO, 4 KHSC\ 

rotAs&ium Sulpharle Nitric Adil paU«alum 

nitrate acid acid sulphate 

The acid pota-s^iutn t«ulphate is reaihly Cfiti verted into nentnU 
sulphate (Putas^i Stf/pknn^ V, S, l\) by dissolving in water, adding 
potawsium carbonate until efferveseBoe cea^u^s, filtering, and i»etting 
aKide to cr\'i*talliite. 

Sodium nitrate, on account of it>' cheap nes-s, is the nitrate from 
which manufacturers no^v usually prepare nitric acid. 

Pure nitric acid, HN* K„ is colorless lifjnid of specific gravity L »^2, 
The riiOHt concentrated acid met with in commerce has a specific 
gravity of 1.5 and contains {Ki percent, of rea! nitric acid ; it fiimcs 
disagreeably, is unhtable, and, except as an estdnir*jtic, is seldom 
UHcci. The V. S, Fharrnjicftpo'ia coutidns three nitric acids : — 
Fuming nitric acid, s(iet*ific gnivity 1.4.37 ; Aritlum Sitrirum^ 
preparetl as above, of secific gnivity 1.403 and cimtaining G8 per* 
cent, tdrcal acid; ami Ari'fufn Xifrimm l>iltifnm, sjvecific gmvity 
1.054, containing nearly Hi pen-en t. Either of the more coo- 



NITMA TES. 





273 



cenirat4?d acids, althoiifjrh ediiUiiuiiijy: water, is usually teritit?d 
'^nitrif acid/* Tht* ^itficiiil mine nrul, *>(' i^pwitif gravity 1,40H, 
IS not a definite hydnms acid iilthyiigii it8 umiiNimtioii iipproxi- 
maU'^ to the fomiuk 2HN(>^, HlL^i) ; itili>^tiUat 248.1)° F. (120..^'' 
C), without chijnj^'t.^ If a less cinitvritrataJ acid be heated, it 
^o»e^^ water ; if a mi>re eoneeutrated iieid he heated, it loses nitrie 
aeidj until the detiMity c»l L4(K5 in rear he J. Aqtmfortiit is* an old 
name tor nitric acid {Atfuu jortij* ifhttpifj', ApeeiHe gravity L22; 
A qua forth dap lex^ 1 . M k T li e * *e< > 1 1 i;e n t ra t i un " o f a »\ )ee i in e ii < >f 
nitric iicid is determined hy volaaietrie analysis. Nitric anhydnik^ 
N,0- (sijiiietimeri, but erroneously, called anhj/drom nitric aciil) is 
a «>ild er>'sta!line hu balance formed on passiing dry chlorine over 
dry nilver nitnite, 

Metidw reduce nitric acid io the vari^ius oxides of nitrogen or 
even to nitrogen itself, according to the euncentnitiun of acid, the 

lijM^rature, and the amount of nitrate present. With certain 
fitelalti, such us mic and iron, and moderately dilute nitric acid, 
itmmoniiim nitrate i^i formed. Thus, with zinc,=- 

10HNO,+ 4Zn = 4Zn(N0j), | NH.NO.H- 3H,0 

Affua RttjiQ,-~X mixture of 18 parlB of nitric acid (TT. S. P.)^ 
and 82 of hydrocliloric aeid (U. H. 1\), forma the Afvdum Altrtt- 
htjdruchhrwum fif the Phamiacopa'ia. The mixture ^lioiild be set 
a»ido for a week in stj miner or a fortnight in wint^T, to insure com* 
plete interaction and fUH development of the chief active product, 
chlorine. 

Aridum Nitrohifdrorhlorir^uiii Ditutum^ V . 8, P., which i» nitro- 
hjrdroehloric acid diluted with water, nniy attack organic matter 
with evtdution of nitnnw ga»e», hetice it should not he dispensed 
with tincturea, ett\, without fnrther dilution. 

A mixture of coucentrated nitric and hydrochloric acids^ is 
known as mjua retpa from it#< property of dissolving g<dd, the king 
of metala, the action i>eing effected by the chlorine which is liber- 
ated. 

HNO, ^' 3HC1 = NOCI 4^ 2H,0 -h CI, 
Kttrleacld Hydrochloric Kitro«yl Witer Chlurlne 



ucld 



chloride 



Nitriwyl chloride t?»an example of the class of compounds known 
AA acid chlorides, or aeichloridi><, formed hy the suhstilution of 
chlorine (Ul) for hydruxyl (Oil) in aji aeid ; thus nitrosy I chloride 
may he fumjed from nitrous acid Nd.OH. The sul>stitution of 
CI for OH is often useful in deciding how the oxygen and hydro- 
^n in a substance are combined, f<»r it is prolmlde that a univalent 
at<im like CI can only l>e substituted for another univalent atom nr 
ratUcal, and therefore if it replaces O and H they miust bepreacut 
aii hydrijxyl (-<)-H). 





THE AVID RADICALS, 

Analyiicid Reactions of Kiirateji^ 

1. To a Rilution of any Ditrate {e,g, KNO^ ) a*ld sulpliuric 
acifl and then copper turiiings, and warm ; colorless nitric 
oxide, N0» 18 evolve^l, which at onre unites with the oxjgen 
ID the tube, giving rfd/nm^a of nitrogen peroxide, NO,. 

2KN0, + 5H,S0, + 3Cu = 2N0 + 3CuSO, + 4H,0 + 
2KHS0, ; then 2N0 + O, = 2N0, 

PcrfonntHi on a larger ^^ale, ia a vessel to which a deliver}' -tube 
is attached^ the interaction of nitric iieid and evrpjier la the proves 
generally adopted iVir the preiuinilioti <if nitric <hxide. 

Small fjuantities of idlratrs inay he (Overlooked when thin test ih 
enijdoycd, the color of the nd fuuies nnt being very intense^ 

Uadilnted nitric arid jHiurHd ii[>ijn eopju r tnniing^-^ gives rise to 
the fomuitinii of dense red vupors wbicli contain nitrogen perox* 
ide, NO., nitnins anbydrirle, ^J\ nitric oxiih% NU, and even 
nitrogen^ N,, tlu' nnution Viirying somewhat according to the tem- 
perature iM' the niixttire ami (Ackwortb) tli*^ quantity of eijpric 
nitnite in solution. With ordimirv copper, dilute nitric acicl gives 
nitric oxide, 3C'u -}- 81INt\ = 3c5u(N<)J, 4- 4Hp -|- 2N0, 

r*i*re nitric oxide may be obtained by treating mercury with a 
mixture of sulpburic and nitric acids ; or by treating a mixture of 
poUissium nitrate 1 part, and ferrous sulphate 4 partes, with t^ul- 
phuric arid and a small quantity of water. 

2, To a cold solution of a nitrate, even tf very dilute, add 
three or four crystals of ferrous sulphate, simke gently for a 
minute in order that some of the sulphate may liecouie dis- 
solved, and then pt>ur some concentrated sulphuric acid dow*ii 
tlie >u\e of the test-tuhe, so that it may form a layer at the l>ol- 
tom : a dark-brown or black coloration will apjiear l>etweea 
the acid and the su|KTnatant liquid, 

Tbi!* is a very delicate test for nitrates. Nitrites give the w^ae- 
tion without the addition of sulphuric arid. The dark color [a due 
to the formation of a compound by the interactiou of nitric oxide 
with a portion of the ferrous salt. The nitric oxide in liberated 
frorjj the nitrate by the reflucing action of the hydrogen of tlie sul- 
phuric aeid^ the Bulphurie ra<lical of whi<'h in absorbed by aiioiher 
portion of the ferrr»ya sulphate^ the latter thereby becoming con- 
verted into ferric sulphate. 

2HNO, 4- 3njSO, -^ fiFtsSO^ ^ 411,0 4^ 8Fe,(80J, 4- 2K0 

The proram of ojridalmn ii* one frequently emjdoyed in experi- 
mental chemistry; and nitrate*^ from their ricbnesa in oxygen, iiad 




NITRATES. 



I 



the readiness with which they part with some of it, are the oxi- 
dising ageut» oJlen selected ibr the purjM>«e. In the openitioii they 
may fto decomj)Ot*e a^ to yield a tnelullie <i,vidi , Jiitrie nxide, and 
oxygen. Ilydro^fen nitrate (nitric acid) coiiununly yields water, 
and the other ^mbj^hinees inentinned, us shown hv the llilhiwing 
equation i^ — IH^M)^ ^ 2H,() + 4N(> -f- 30^. 

When nitrates, oilier than nitric aeid, jire used for the {nirpoHe 
of oxidation, a strong acid, geiierally wuiphiirie, if^ UMially added 
in order that nitrie aeid may he forine<l, the hitter splitting up 

»more readily tlian most other nitriites. 
The Jive ojkfrM qf tiifrOf/tH have tunv lieen mentioned, namely: — 



Nitrous oxide (langbing-gaa) 
Nitric oxide 
Nitrous anhydride 
Nitrogen peroxide* 
Nitric anhydride 



N,0 
NO 

NA 

NO, or NA 

N,0. 



I 



Nitrous oxide h a eo]orlen8 gas, not altered on exptjeure to air. 
Nitric oxide 'n^ also eolorlesn, hut gives red fumes in tht^ air, owing 
to conjbinjitit>n witli oxygen, 'Si\ being formed. Nitrous anhy- 
dride fiirins a red va|tor eontlensiljle to a hluelitpiid, recent experi- 
ments proving that the red vapor is merely ji mixture of nitric 
oxide, NO, and nitrogen peroxide, N( *,j ; it i*« only in the lii^nid 
stjite (at or t>elow* -21*' ('.) that thecAnipouncl, N^O., exists. Nitro- 
gen peroxide ia a red vapor condenMihleto mitir^inge liquid. Nitric 
nnhydride is a colorless cryHtjiUine 8«jlid. The two jinliyclrideH, hy 
intemction with water, yiehl re^^jtectively nitrons acid, HNO,, 
(stable at low teniiwraturcH but deeoiiiposed on heating), and nitric 
aeidj HNO^. Nitrous r»xide Is uhit i>robahly an anhydride, cor- 
rt*H J II m ding to h ypon i t ro u s a ci d , H , N ^t ), , T h e si I ver n n d s* i* 1 i u m 
units of the latter have the formuhe AgyNjO^ and Na^N^O 

The compound?* of nitrfigen and oxygen, fonntdated above, 
furnish a good illustratiiui of the law of multiple proportions, 

H. Direct the blow-|>ijX:^ flame against a piece of charcoal 
until a sjxit is rtHJ-hot ; mm place on the s{>ot a fragment of a 
oitnitt* ; deflagratiou eD^ues. 

Tlds reaction dfies not disiingui,sh nitrat*:^ fmm chlorates, but 
indicates the presence of these or other highly oxidi^^^d salt^^, even 
whon the quantitie* are small antl other substances are mixed 
with thoni. 

fiunpmvd^r is an intimate inerluinirid mixture of 75 parts of 
nitre, 15 to 12J parts of charcoal, and Id to 12j parts of su!]ihnr. 

* At low tempf'nitorrft nifroirf'ri |M^roxJde is ri'yirt-wnU^d Uv tlic fomvuhi 
Ni(>«. The molfc«U-J4 of NaO* d*M*ompo«o, howovrr, on gently warming 
va form 2N0v. 




\ 




276 THE ACID RADICALS. 

In order to a void explo^^iiin^ the iiigretiientH uiust be aeparately 
grouml, then mnij*t<MJtHl with water aiiil mixed to a pjLste, which 
is iirterwanl -i^raniilateii und careful ty drietL When iired it may 
Iw mid to yieid potassium sulphide, K^S (tbe wliite Rmokf), nitr<»* 
gen, N,, earlMJiiie oxide, CO, and carbonic anhydride, C< >^, tiirmgh 
the <ieeonxpr>Bititjn i?* seldoui ei>mplete. The i^uddcn jiriKJuctioii of 
li hirge quantity oi' highly heated gas from li »mall quautity of a 
cold solid is sufiicient to account for the effects produced by gun- 
pi iwder wbcii tirixl. 

4. Ti) nitrio add or any other nitrate add a solution of aul- 
] jhindigutjc acid ( imli^o stil phate >; the blue wlor is discharged. 
Fre^ cFilorine also dei^troys the color of thia reagent. 

indigo Test Sohition, U. 8. P. — This is the sodium or potaaei urn 
aah of indigotinHlisulidionic acid, C^^H^ (HSO,)^,Oj, dissolved in 
vvHter, 1 part in 150. 

Anttdofe,— In ca^eHofpois^juingby nitric aci<l, wdution of wxiium 
carbonate (common washing suda) or magneaia and water may be 
administered im antidote. 



QUESTIONS AXD EXERCISES. 



Timco the orij^in of nitrat<?8. — In what dm^ i-iibic nitre differ from pris- 
matic TO t re ? — Describe a prix't'^ by wliich potessiiim uitratc may bo 
obtained artificiifclly.— 8tttl4?! the ditft?nMie« botwetiii ordinary nitrwaiidsal 
jiruuella.— What iij!. thu aeid radk-al of the id t rules V — JIuw ii* the ofliciM.1 
iiitrk add pn-part-d ?— <rivt? the prui^nity* of nitric acid.— What ri^&t'tictnfl 
«jccurwbeti *xjii€t^ntnite<l oi trie and hydros hltiric adds are mixwl?— How 
\& nitric oxide prei«ire<r/— Enumerate and <^xpluin the testa for nitratea. 
— What rtclufti«u ppwlnct-? nmy be obtaiiiL't! from nitric acid when it la 
emph>yod as an oxiiliziu« aj^eat ?— How is nitrous oxiile prepared T— 
Enuniumtt' the live oij<k'>Hof uitro^reo. — What m the nature of iran powder? 
— What quaatity of Ltibic nitre will be required to produce ten carboys 
of official aitricacid, each containing 114 lbs.? 



HYPOCHLOEOUS ACID. HCIO» ANB OTHEB HYP0- 
GHLOEITIBS. 

Experiment^ — Place a few grains of red mereuric oxide i'or 
better* a small i^jiiaiUity of moist fresh ly-preeipitated yellow 
mercuric oxide) in a tes«t-tylM:% half fill the tube with chlorine 
water, well *<biike the mixture, and filter ; the resultinj: liquid 
is a holutioti of hy|)ochlorous acid,, mereurie oxychh»ride 
remainititr undis8oIve<l : — 

2HgO -H 2CI, ^ H,0 = 2HC10 ^ Hg^OCl, 



HYPOCHLORITES. 



277 



By the IntcnictiflTi of hyot'hlorourt acid firul oxid*?i» or LyiiroxideH, 
ttthi^r purt* hv[>«*i'bl<>ritt'?i ure foniieti: — IIC'IO p NaOH = NaClO 
t H,0. 

The M'tioD of ch!r>nue (ju metdillic hydroxides gives i\m to 
"Meachiiig sjilt.s/' whirl i are I'ltber mixtures! of hypix'hlorite vmd 
rhlonde, or eompcmiids ijiterutt'diate between hyt>ochJorite and 
chloride {i^ee p. 119^ Chijr Ohfartuata^ V. 8, V,, alno p. Itl, Li<faar 
SfMiV ChhrinaftF, U. »S. P.). 

CI, + 2NaOH = (NaClO^NaCl) -f H/> j 
2Cl, 4- 2C«(< >H), - (C'aCl.O,, CaCI,) -f 2H,0. 

The action of strong acids on '^bleaching aalU*' results ifi the 
evolution of cldorine ; hence the gre^t value of chlorinated liuit? 
in hi caching operations: — 

(CaCip,, CaCl,) + 2H^S0^ = 2C1, + 2Ca80, -h 2Hfi 

Oil expomire to oir solutions of hypochlorites are slowly decotn- 
|K>w*d with libcratifjn of hypoehlorourt acid, recognisable by its 
j>e« uljar odor:^ — 

2Na010 + CO, + H,0 = 2HC10 + N%CO, 

Tlje {peculiar odor of this acid, the lilx^rtition of chlorine on the 
Addition of a strong acid, and their bleaching powers, are the 
ehiLnicter8 on which to rely in searching for hypotrhloritcs^ 

CHLOEIO ACID, HCIO,, AND OTHEE CHLOBATES. 

chlorides are fomicd hy boinnf]^ aqueous HoIytinrit< of the bleach- 
ing Kfdtrt (chlorinated lime, chlorinuti/d .s^ida, chlorinaUHl poUish). 
Heat thUB convcrtj^ — 



3(XaClO» KaC!) 



3(KClO, KCl) I 
rhloriMbed 

pousb 1 

S[Ca(C10>„ CaClJ 1 

Chlorinated '. 

lime i 



into 



into 



into 



NaCiO, 
BodJum 

chlorate 

I KC1(\ 
• l'i)CA.*4ahim 
i chlonitL' 

I chlonite 



I 



and 



and 



and 



riXiiOl 

HjhIEuiu 
{'hUii-lde 

Mm toss t inn 
I'hlftrldo 

r>CttCi, 

COlodUti 



Potassitmi CMorate* 

PotawHiurn Clilorat<? {Pofaml Chktrm^ V, S. V.\ is comnierci- 
iilly made by maturating with chh»rine gai« a moistene^^ nii?ctnr«^ of 
8|)artiiof potaanium chloride and 10 of calcium hydmxidc* and 




^K£ 



278 



THE ACID RADICALS, 



well boiling the prcMluet. Ch!orinai4t?d liine i.>* tirst formed; this, 
on iMmtitiucd boiling with waiter, w'jlit^ up into (.-uleiiiui cblori^ic 
and ialuinm i^hloratf ; ;ind the htlU^r iulemrting with tlie |>otj4(*- 
hirnu L'hloritlf yieldw t;alciuin clilnriik' anti |K»ta.ssimii i-hlorute, 

6Ca(OH), + 6C1, = 3[CaCl,, Ca(aO)J + 6II,0; 

UalClO,), + 2KC1 = CaCl, 4- 2KC10, 

The oj K-ration inity he conducted on a small M^ale by rahljing the 
ingrL^di tilts ln^rtht^r in a niortar in tiie foregoinjy^ jjn>jnjrtion.H, add* 
ing i'liiHigh wnti'f lo make the whtile aissume the chtiracter oldjuni) 
lunipti, plju:ijig the ponms niass in a funnel (loosely [>lug|tred with 
fnigiiieuts of glasw) iind jJUSHinjj^ ehlorine up liirough tlie muss by 
altiiching to the neck of the funnel the tul>e delhering the gsi*. 
When the whole innate hi\s become of a flight ]>ink tint (due t<j a 
traee of perumngiuialr fnim nrang3ine^«e preK^nt tin inijiurity in the 
ealeiunj hydrf^KidL*) it .should he Inrned int<i a di«h, irtft boiled 
with water, filtered, the fiHrak' evaporated if neeetwwiry, iind net 
aside; the potaK^injo ehh>nite weparale.s in tabnhir momH'linie 
erysstali*, ealeiuni ehloride renuuuing in the niotherdiquor In 
ihi.s prr»ce*« pf*tas«4*iuni earbouate niay be used in the jdweeof j*oUi*i- 
sium chloride. 



f .hlunno PotiiaBlum carbotmtc 

2KC10, + CaCO^ -f 
FotajtuCam Caloluto 

cblurftiu carlxjiuHo 



6Ca(0H), 
Calelum hydroxide 



5Cttei, H- 

Caleluti* 

chloride 



WakT 



FotiLssium eblonite is now prepartnl on the commercial K^ale by 
I lie eleetrolysiis «d' a solution iff |iutaHsium ehloride. 

Fota«!^iunj ehlorate iw soluble Is water to the extent of tl r»r 7 
part.H in ion at ordiniiry temperatures. It m usually athidnihtere^l 
II led i t i nal 1 y in a q u et i n h po 1 u t ion , mm e t i ni es a 1 st > in 1 oia' n ^t> ( Tto- 
rhiitri ihitng^li Chlorafu^, U. 8. V. K Potai*t<iuni eblorate nniMt on 
no jieeount be rubln^d with t^ulpliur or fc<ylphidc% in a mortar or 
otherwist*, friction of auch mixtures often given rise to violent 
explosions, 

Potai<i*iam chlorate when heate<i to a temperature not greatly 
beyond its ftising poJnt^ yiekk polaj*siuni chloride and oxygen » 
and ii4 the salt eoramonly employed in the preparation of this ga/* 
for experimental pur(iOf*et*, If the action be carried i>n at a* low 
a temperature a.*^ possible, and lie arre^ttnl when one bundre<i part« 
of the chlorate have yielcietl 7.84 parts of oxygen, the resfidne will 
be found to contain onlv jxitiiKMium pcrchlorate, KC10.» and chlo- 
ride; lOKClOj = ♦iKClb, - 4KCI -I m^ (Tead). A higher leni- 
perature causes the deeomp<i!?ition of the perchlomte; KCIO^ = 



CHLORATES. 



279 



KCl -f 20,. When iht^ dilnratf is heak^d with raanganc?«e per- 
oxidc% no porchlunitt' is tbriued. 

ASmiittm ('h/ontft itStttlii. ChfttrttA^ L\S.P.), NaClOjj, is }>reparetl in 
the sanie way aB |M>iit.'vsiani thlurate. 

Chloric iwld^ HClt)^, iimy 1)l' isulated by deeomposing barium 
chlordU* with dilul^i 8u![»huric acid^ hut 18 uiisfahle, tjuickly det-om- 
[Mjshig into chlurine, oxygen, and |»frcbloric ae-id. 

Analytical Heaction^t of Chlorates* 

1. To a solution of a chlorate add sijlutioii of silver nitmte; 
no precipitate is jirodured, showiog that silver chlorate isBolu- 
ble in water. Evajx^rate another portion of Lhe solution to 
dryness, and place the residne in a small dry tet^t-tube (or 
fimply <lrop a fragment of a chlorate into a test-lobe) and 
heal strongly ; oxygen is evolved, and may be re<*ognized by 
its power of rekindling an incandeiseent nnitch inserted in the 
tiil>e. Boil the residue with water, and again add solution of 
silver nitrate ; a white precipitate it^ pro<lueed whirh jxiisaesses 
all the characters of silver chloride, as described under hydro- 
chloric acid. 

2, To a *inmll fragment of a chlorate add two or three dro|>« 
of concentrated sulphnric acid ; an explosive gas, chlorine 
peroxide, CIO,, is evolved, which somewhat resembles chlorine 
in odor, but possesses a dce[)er color. 

3KC10, + 2H,80. ^ 2C10, + KaO, + 2KH80, | H J). 

Warm the upper part of the test-tube to 150° or 20tP F. 
(65,5*^ to 93 Jl'^ C ), or int rot luce a hot wire : a sluir|) explosion 
ensues* due to deci>njjHisition of the ebloriue jjeripxlile into 
chlorine and oxygen. 

3. Heat a aiuall fragment of a chlorate with hydnR*bloric 
acid; a yellowish green gaseous mixture calked ettrhf^Hin' is 
evolved. Its coKjr is dee[H^r than that of chlorine, hence the 
name (from to, c«, well, and x/.vifn>^, rhfnroi^^ green |, It is 
really a mixttire of that element with rhh^rint* [)t^roxide, 

4, Direct tlie 1>low]*ipe-tlanie against a piece of charcoal 
until a spot is re^bhot, and then phice on the fi]m{ a fragment 
of a chlorate : deHagratiou ensues, as in the case of nitnitee. 

Brrchlorit* and, HriO^. — Cmdo potassium perch I orate olita in ed 
I id ready d esc ri bed, is boibnl fiii a fanif-cupboHrd) with hvilro- 
iiloric acid to deeoaipose any chlorate that may l^e prcX'Utj imd 
then (»e|>arate4i from chlonde by watching and crystalllzatifjn, chio- 



280 




THE ACID UADICALS, 



HJe lieing far more sc^luble iir waler tliaii iierchlorate. Perchloric 
add h then obtaint^d l>y distilling the potaHHiutn jjerchlurate with 
»ulpliiiric at id; it is stable^ and in fHjcasioimJly administered in 
medicine. 



Table of the Chlorine Aeith. 

HydnR'bloric atid . . . HCl 

HvjKichlorous add . . » HUlO 

eijloric acid HCKJ, 

iVTcblorie acid .... IICK >^ 

Tbi* acid radiimlt* of the above chlorine acids are univalent, 
indiuated in tbe viirions ffirmuke. 

BromateB. 



^H 



Broniate^ are salts eloHcly resemblinjr chlorates and lodiites. The 
rommla of bromic liciil is HBrUj. The prcs^ntT of hnumites^ as 
impurity, in bromides is sbmvii by the production of a yellow ct>lor, 
due to the liberation of bromine, on the addition of dilute aulpliuric 
acid. 

oKBr + KBrOj, i tJKH,SO, = tiKH80, + 3H»0 -j- 8Br, 

lodates. 

lodie Acid^ HIOj.^ — Iodine i» wanned in a fl»u«k with five times 

i Ik weight of fViming nitric acid (sp. gr. 1>437), in a funie-cypbourd, 
until wW nctiojj eeaw^ii. {)n cnoling, irnbc acid st^paratci* in Hinall 
pyramidal crystals*. These are separated, the reJ^i<hial liquid eva- 
porated to dryness to remove cxce^ of nitric acid, the residue and 
the first cTop of crvi^UiIs di-^solved in a .•*niall quaiUity of boiling 
water, and the solution s^^t aside t^M-rysUdlize, ^^^utralized with 
(^iirbouaten <ir hyiln»xidej!*^ it yield*! iofhitr^. 

i\*t;isi*iiim imlate and *^ulpburou>^ acid mutually interact with 
cliniinatiioi of imliiie {and formation ofn blue <^ilor, if starch he 
present). Snlphnrtms acicl occurring a.** an iropnnty in acetic and 
cottier acids may thus be detected, 

J^rrtc iwlatey or nither Ox^io*iate^ FejO(IO,)^, 8H,0, is predpi- 
tate<l on adding a solution of ferric chloride to s4*liition of pota^ium 
iodate. When heated with Kulptinric acid and potast*ium Idchro- 
mate, most iodides? are decomposed, yitdding iodine ant! u Mulphato 
of the metal ; silver iodide, ht>wever, iw an excc|»tion, as, though it 
gradually diswdvt**^, no io<hne is separated, and on diluting the 
solution and allowing it to cofd, a yellow precipitati^con^itttingof 
impure silver iodate is depopitetK 





QUESTIONS AND EXERCISES. 

How may hypoclilorftus iM.^id be foruied? — By wJjat reaction m cblorioe 
eliminated from hypocbloritea?— State ih« Keiienil rcactmn by whit:li 
(!hlorat€^i!s Jir*' fiiirnifd. — iiivt* df«tails of xhv prt^jmrutioij ot {MitiiBgiuin thior- 
ate. — Mt'iition the prii|)erties uf ]MitU5iHiuni cbbjrate. — What decomjKtsitioijs 
occur when potafisiuni chlorate is heati'd'/— Find the fonnula wd^ht of 
potiifi»it]in chlorate.— What weight c»f oxygen b ijnKluutsl when 1 ox. of 
puta.«Kium ch1oTBt«' is com plf^ telly dt'conifjosed, and how mm'h potjissium 
('hloride remains'^ — *>ne hnndred eiihic ioeli<^ of oxyjuferi. at (JO'^ F> atid 
barometer at «^l incheti, weighhij^ 34.013 KtiiLiif^, and one gallon contiiiuitig 
2771 cubic inches, what weight of jKitasHiuni ihiorati* will be rt^qiiirtMl to 
yield 10 gallons of the ga«?—.lM*. 54 oz. — ralciilate th€* weight of potas- 
mmi chloride obtainablo from IDOpartnof jiotaHsium chlorute.— How may 
the prcj^ence of chlorides In chloratt^s be demonstnited?— Mention the 
t««t0 for chlorate-s.— Give the formula of chlorine peroxide. — What ia 
«tiehloTiue? — How ia pt>rehloric acid preiiared? — Euuiuerate the ehlonue 
adds. — How may iodic acid be made t 



I 



AOETIO ACID, HC^O^, AHD OTHEE ACETATES. 

Source. — Acetic afid is^ Maid to oecur naturally in ^^iHall ijHiintity 
in t'l^rtiiiii jdant-juices and animal tluiil^i, Imt i^UHUally an artitirial 
prtnluct. Much acetic acid is prodvire^l during the destructive di^*- 
tilhitifiii of wood. When first dis^ nvered in tliiB operation the 
add wa,s rega rde<l m a new otie, and w;i8 naineil pyroHtjmaiinttrhi^ 
A hyhnd word from TfY», pm\ fire, jind fifjitutn^ wood, a term ntill 
Maineii for the crude acid. The latter, neutraliw_*<l by ralrium 
ciirl>onat<*^ tbej^olution eviipf»rated to dryness, and the ri^i due gently 
heatf'd to drive off vohitiie tiirry mattcrH, yield** ealeiuni acetate. 
Acetate* acid is obtained in a Ktate fif iiurity (mixed with water *m\y) 
by starting from thii* crude ealciiiin acebite, converting it itito 
Aodium acetate, recrystHlli^tinii^ the latt4.'r liiid dif^tilling it with 
dihite Hiilidmric aeid. Diluted acetate acid m HcmietinieK sold ns 
irA ift Hrtegar^ one o f t he m a n y v a r it i i^ of rhi *tjtt r, 1 1 h as I u 'c n k no w n 
AM wmd vinegar for the past Hixty or «€vent>' yean*, it m^ jccnerally 
colored brown with caramel to meet the Uuste of the public. In 
Grnnany and France lar^e qiianliti£»» of acetic acid are made by 
the oxidation of the alcohol in inferior wineti, in the pre^i^'nce id' a 
bacterium called Myeofterma sirefi |the linrtfrium Mymikrmi id' 
Cohn) ; hence the uhifr-winf m\i\ red-ipiuf vinegar* {vim'yar, from 
the French mi, wine, and aign% ^our). Thii* hacterinm may In* 
cultivated, and the manufacture of vinegar from alcohol and water 
i« carrietJ out by it-s aid tm the large BCJile, In Enj^land alwo the 
domestic form nf acetic acid (hniwn vinegar) commoidy has an aleo- 
"iolie orinrin : infuMtnn of malt and imnmlted jrrain, or sonvetime» 
Ijitter iilonc after treatment with >^uli»huric acid, in fcmientcd ; 
the remilting alteration of its ^uit^ar, inntead of being arrested 
when the prcwluel w un alcoholic lit|uid, a »ort of beer, U allowed 




282 




THE ACID RADIVAUS, 



l*> go on to the next ntnge, arelie urid ; it usimlly t<Hititiu-s from li 
to (} jjercent, of jictnal uietit: aiid or bydnij^i'n iicitale, }ir,H i\^. 
DitFerfnt slR^nglh?* of vinegar nri.' soM uimIit tlie iiumbei^ liJ, 18, 
20, 22, 24, correnpontJin^^ U^ ihe nuiuher nf gmins of anhydrrnis 
«odiiiJii earbmiale neutriilizfd by nne iinperiiil fluid ounce of the 
Wnegiir, or, broadly^ to 4, 44, 5, h\ and 5 percent, of a^etk ueid 
retipectively. AH oftbe.se *'brewe<J vineg^iirw' ' are further colored 
witli cjiraniel, to j^uit the popular IwsXq, Vhtegar u a generie term 
applieable to any one or idl varietiea. It8 essential component is 
aeetie aeid. 

Vinegar <d* S(piill {Acdttm ^SdHfCj U* S. P.)^ and Vinegar of 
t)pium (Aretnm Opfi^ U. S. P.), Qf *' black drop/* eouttiin dilute 
acetic acid, tlnit i.s, ivrjod vitirfpir. 

The acetic radical, t/jH^O',, la univalent. 

Acetic acid in regarded a.s euritiiining tlie radical rt^fff/f (C^H^O) 
united with hjdros^jl (OW), and the acctale« hk containing meUil in 
place of the hydrogen id'thebydroxyl grou|i. By iuteraetirjii with 
pho8{>horu?^ trichloride, acetic acid yicldH acetyl ehlfkride, rjljOCl. 
Acetyl chloride and sodium acetate ijitcract to give c^otlium ehluride 
aod acetic anhydride. 



C,H,0 \ d I 



C,H,00 JNa| 



\ ^ (C,H,0),0 + NflCl 



Bv Interaction with water, aeetie anhydride yields acetic acid : 
(C,H/)),0 I I1,<J = 2C.,ir,0,. 

N*^e on j7J%(/riV/<f.«<. — Up to this point an :mhydride lia^ Ihhmi 
regarde*! m a snbi^tance derived from an acid by reraovul of the 
whfih bydn>gen of the acid, together with as iriiicb of its oxygen 
m with the hydrogen forms water. This dtn^s not a[iply to acetic 
anhydride, and must therefore lie somewhat *|uaiihed. An anhtj- 
dridr is deriveil tVoui an acid, the acid having lo>t the whole of iU 
repiai't'dbk hyJrogcu, and m much oxygen a» is neceeeary to form 
water with tliat hydrogen. 

The rdatitin of jicetic acid to alcoli(»l will 1m? evident from the 
following equation representing the fornmtion t>f the acid : — 



CHO 

Alcohol 



o. = 



C,H,0 + 

Aretk; ftcnd 



H,0 



Arefatfjt in aqneouB solution or*' liable to decompoftititin* In f*ohi* 
tion of morphine acetate a fungoid growth oceasionally forinF, ace- 
tie acid disappears, aivd morphine is depo«it*Ml, Solution of ammo- 
nium acetate Ih liable lo a similar change, gradually becoming alka- 
line. 



ACETATES. 



283 



Ezpeiiinent.^ — ^To a few graitis uf i^otljum ueetnte iu a tesit- 
tube, nild dilutti sulplmrk acid, tiud iieat ; acelk* add h evolved, 
and may t»e coy doused by pa^siug it tb rough a bent tdbe 
adajjte^i to the test-tube by nieaus of a eork iti the usual way. 



ik>dium 
ftcelate 



ijulphiiric 
acid 



Atetlc acid 



Ac'ifl s<idium 



I 



The ubuve i** the jirocei^ii by which acetic acid h ol)taiiicd from 
KKliuiLi ur calciiria acetiite on the lar|re ticak'. An in the ca-se^ of 
uitric Hiid hydr<«*hlurie acid?^, the term ''acetic acid'* is UKUully 
applied in the lujucoua tiolutiou of the at* id. Avidum Acdit'timj 
V, fc?. i**, cootaiof* not lesH thioi M perccut. of liydrogeu acetate, 
UC^HiU;,. Avhiatii Aftiicum Dihdutti^ IJ. S. P., coiitaiu^ uot lerfc* 
than i\ percent. Glacial auLtic acid, HC^H^Oj, eoatahii* n^j water. 
It Holidifiei* to a cryt<talHrie rnuK'^ at teiopcratures helow (]*i° F. (t7, 2® 
C), hence the apjK*Hati(Oi ijlariai (frfjio ijhtch^^ ice). Go(id com- 
mercial glaciid aceUite acid {Aridum Aceficum Oiticiaie^ U. 8. P.), 
dttes nut contain more than 1 percent, of water ; it solidifie?* when 
cooled, and again litjuetics at ahout 51lF F, (lo^C); it,s specific 
gravity m 1.049. Although water h »pecihcally lighter than this 
iicetJc acid, yet the addition of water at first raises t lie sji. gr. of 
the acid ; evidently, therefore, coo traction takes place oii mixing 
the liquidtt : after 10 percent. liaN been added, theadditiorntf aiore 
wat^r produces tbe usual effect of dilution tjf a liquid with oue 
B|^KHrifically lighter — nameiyj lowering of tbe Hpecitic gravity. 
Glacial acetic acid iuixe» readily with moisit uila. 



Anaii/tieai Rectction^ of Acetatei, 

1* To an acetate add .sulphuric acid, and heat the mixture ; 
the characteristic odor of acetic acid is evolved. 

JW<. ^Iodine, rndphurrms anhydride, and other subHtaricefl 
which piwst^srt a powerful odor, may mask that of acetic acid. 

2. Repeat the above reaction, a few druf« of alcohol lieing 
^m added to the acetate ; acetic etlier (ethyl acetate, 
C,n/'.H^Oj), poeseesiug a characteriMic pleamnt o<h)r, is 
evolved* 

3. Heat a fragment of a dry acetate (|)otas8ium, fiodium, 
i^lciiim or barium acetate, for example) in a test-tube, ttud 
Qotiee the mlor of Mte gaRe<m«« prtxlucts of tbe de!corn]>oiiiti<iJi : 
among them is nretonr, C*,H^O, the odor of whieh is cfnir* 
acteristic. Blackeniag takes place in most caseH, A cariMin- 
ate remaitis in the test-tube. (iScc tests for carbonates) 




284 



THE ACID RADICALS, 



4, To a Sfilulioi] of an aretate,, nm<le neiitriil by the addition 
of aciil or alkali, an Hie citsi^ may lK^ arid a few droj-w* of uey- 
Iral siohiliiHi i»f ferric rhltkride ; a *leep-red liquitl resiiUs, owing 
to iht^ fonaalioii of ferrie acetate, I*«^(t-'jri^Oj)j,, Boil ; a red 
lireei[iitate of lerric oxyacetiite is torme^J, leaving the liquid 
H>lorle;s». 

A milif Heal Nofr.— The student 8h<mld observe that all normal 
atM44tt€H are soluble in water. iSilver act-'tate, Atrt^ifH^O^, and mer- 
turfkus iieelate, HgC^H^O.„ urtM»aly sjmringly MiluUle in cold water, 
lull the fiu't eiiu sekluin 1>l* uLiJized in anulyf^i'*. Henee, f»redpi' 
lathin n^il being iivailable, peeiili unties of color and cRlor, the next 
Iw'.st eliaracten^ ou which to rely^ lire a-Hiially adopterl h^ meam* by 
whieh aeetiites may be deteeted. Most aeetate*<, like many other 
urguuie comjMJUud.s, eiiar wiien healed to a high temperature. 



QUESTIONS AND EXEHCISES, 

Wliat is the formula of aeetic acid ?— State the relation of acetic aeid t<» 
other aoetates. — What i^ the fnolecahir weifjht of ivcetie acid ? — Name th«* 
source^of aeetic arid, — Whnt i« pyrtjl igneous acid ? — Fniiii what I'ouijxujtid 
is the aeeticacid of mi>st varieties of ^iDegar derived t — What is the ualurc 
of the '* Vinegars " of Pharmacj^ ? — How luuy acetic acid Ih' obUiined froui 
sodium acetate V— How much hyilrc»geii acetate iscontaljied in each of llie 
oJlicial acetic acids?— Enumerate the teats for aeetJit<^. 



HYDEOSULPHUMC ACIB, H,S, AND OTHEB 
gOTJ>HIBES. 

Oemrrencr ami ratiefk^ of Suijjhtn\—Th€^ acid radical of hydro^' 
gen mtphidr^ hyfirrmtfphuriv w-id, su/phydric ntid, or i»tfphnrftted 
hydrofjnt and f*'thc-r jiiilphide**, is sulphur, 8. 8uliditir mrur^ free 
in nature, and al.s<j in coinhiaatiou with metaln, as aln^ady ^tatetl 
in ilefUTihing llie oren of «oine of the uietals. It aim iM-enp? in 
coal, chiefly iv** iron jiy rites, and nnlphur eoiujiound.s are obtainwl, 
iu« waste-t*rfKluetM, in the nianufaeture of eoal-gsiH. Altwt of the 
sulphur used in medicine is iniiwirted from Sieily» where it occurs 
ehiefly as»ociate<l with blue clay. It i^ luiritied by fusion, liubli- 
mation, or distillation. Melted and |M»nred into niouldw, it fonnu 
roll mlphur. It is* ^li^rbtly volatile, c%en on a water-bnlh. If dis- 
tilled, and the vajxir carrier] iut<> lar^e chainherw, sf» that it may 
Iw* condenHed rapid ly, it form;* er\^»talH wd^ieh are wi minute aa to 
give thcHulphur a i>ulvenilent chanicter; this is MubHmrd nnlphur 
iSulphttr Sfildimahtm, W 8. P.), or Jlowrrs of mlphur. Sulphur, 
wai*hiHi with ililule ammonia to remove traces of sulphuric acid 
(odea 0.1 percent, resulting from very slow oxidation of f^ulpbur 





SVLPHrOKS. 



285 



I 



in iirdmary maist air), or, posj^ilily^ arsenous sulphide, cript«titiite8 
wtt*hrd mtfphnr [Suifihur Lohtm^ I*. 8, P.). The thinJ common 
f(>rni» prccipifaff:d ttu/phnr {Sitij/hur Prfiripfffifnm, U.S. P.), will 
bf notii*ed siib.stMjueutly. Hulphnr also ore urn in iiiiture in eoiu- 
bimitifm as a ormslitnent t*r aiiiniiil and vegetahle tis^sues, as jiul- 
phurouf^ atihydrirle, ^^*)^^ in vidranic vapors, and a^ hydrogen miI- 
[thidv in wine minimi wakTs. Sulphur exists in several allo- 
Iropic l:orni-% of whit-h the tVfJlowing lour may he noticed :— 1. 
Octahedral sulphur— the native and miM. stidjle forni. 2. Pris- 
matic sulphur, ohtained by meltiujr the octohedral variety, :ind 
cfjoling until a vnif^i formw. 3. Pltustie Huljdiur, *jhlained liy 
heating melted sulphur to ii tempeniture of (441 *"* V.) HM^ F., and 
pouring into cold water. 4. Amorphous sulphur, olitained iu the 
proportion of 5-6 percent, when the octahedral variety issuhlimect 

AUofropif. -^Thv. existence of inore than oue variety of the siiiuie 
elementary suh^itanee (as inHtance<l in the varieties of sulphur 
enumerated above) illu*<trates what is ktio^va ia chemistry as alio- 
tropy (d>;iof, fi/iftSf anfjther; rfdn-m-, fmpm, c<mdition). Other 
inat&neesare met with in the ditTereiit fonns of carhoji, phosphorus, 
etc. 

Bkwk mtlpkur or Sufphttr rit^um nigrum is the misleading name 
of a grayish mixture of sulphur with a ^tent variety of imi»urilic8j 
generally including ar»eDic, The article should not be lased for 
any medjcinal purpose. 

QiiatU hale/ter. — 8u 1 ph u r beha vea n» a fte x i vu I e n t eleji i e n t in sub 
phuric anhydride, SO^, a substant^e which will be noticed uinicr 
sulphuric acid, and as tjuadrivab*nt in sulphurous anhydride, 80,, 
while it is frequently bivalent, as in hydrogen sulfihide, H^. 

Motfenlnr Formula, — At teaipemtiires between the boiling point 
of tulphuT (448,4*' C.) mu\ about \m\f (1, the vajior tlennity of 
inlphur gradtially diminishes ;is the temperature raisea. AlMwe 
ICM>0° C., or acj, it i« constant and then corre>^pfUids to the mole- 
cuhir formula 8,. 



Precipitated Sulphur. 

Experiment 1. — Prepare Prtrijntatrd Stdphur ( Sulphur Prrie- 
mpiffttmn IJ. S. P, ), or Milk ofStiiphur, liy Iwuling a few grains 
of Hq were of sulphur ( 2 parts ) with ealeium hydroxide ( 1 p»rt ) 
and water in the te^t-tube (larger <jiiautities in an eva|Mjniting- 
basin), filtering, and (rej^erviiig a siuall portion of the filtrate) 
adding dilute hydrtx'hlorie acid until the well-stirred milky 
liquid still has a faintly alkaline reaetion to tc^t-paper; sul- 
phur ij* pre<*ipilale<l, and may i>e eolleeted on a filter; w^uibed, 
and dried (at alHnit 130° F.,' 54.4'' (V). Excels of atid must 
be avoided in order to prevent contamitiatiou of the precipi- 





286 THE ACID RADICALS, 

ttite with tracer of areenous sulphide ffram the decompositioD 
f>f any tliian«eiiite, produced from arst'iwus sulphide present as 
impurity in the s^ylphur cmphjyed). 

Thii* IS the inethixl of the Pharniaropceia, — Calcium poly- 
suljdiidt' aud thianulphate are first forme<ii — 

WnUm), + 68, ^ 2(ji8, + C^a8,0, 4- 3H,0 

On adding the add, hnth ^ih» are de('onip<is<^d mid (partly in 
conaequenc* of an iutenneiliale reaetion) !<nlphur t^fparate**: — 

2CaS5 + CaS O, + 6HC1 ^ 3CaCI, + 3H,0 + 68, 

Calcium Cjikfiim HydnM^hlorlc rHicium Wiiler S«]jih«r 

I»f)Iyiiulf>hidt' thioKuIiihiiU* iieid ehlorkle 

The ealriuni [>oly-'<ulphide yields hydrngen t*nlphide and milk- 
white i^ulpluir ♦»n thr iiddition ot' tlie iiiid. Tlie talrium thirwul- 
phfite then yields f'nlphurous aidiydrifle as well iis yellowish 4*ul- 
phur. The pise.'^ internet Jind (?ive ,«ulpliur and water, very little 
hydmi^en f^ulphide ejif aping : this ih the internteiliate reaetion just 
allitfied to. A little pentath ionic mid (p. 2(>ii) is also said to be 
formed. 

4H^ H- 280, = as, + 4H,0 

Experiment 2,^Calrareonii PredpiMed Sufphnr. The otd 
*^Milk of Sulphur/*- — To a sulphur saolutiou prepared as before 
(or to the ret^rved pirtiou ) add a little dilute suljdiurie acid ; 
the precipitate Is in thii* case largely mixed with c^ileium sul- 
phate: — 

2Ca8^ -h CaS O, -h ^U^O + 3H,0 = 3<<:'hSO,/2H,0) + m 
('Alclutn rnlrium PulnluiTtc Water CAlcUim »alpbiite Sulphur 
pt.ilyiiuliphUl*" tlii'>Ku1plmltf aeid 

Place a little of each of these fif>ecimen.« of **prenpitated sul- 
phur/' with a i!rop of the HU|>err»rtant liquid, on a strip of 
plasH, place a eover-jylaas uixm each, and examine the precipi- 
tate** under a mieroscof)e ; the pure s<ulphur w^ill be found to 
consist of minute grains or globules, the (.mlearei>us pre<'ipitate 
to contain comparatively large crystals (hydrons calcium sul- 
phate). 

iVo/**, — Htimc of the precipitated sulphur met with in trade in 
England, i* 8tiM thus mixed with calcium sulphate, noM of guch 
sp(^'imens c^miaining two-thirds of their weight of the latter sub* 
stiinre. Formerly, purcha.'^ers were so accustomed to the siitiny 
ap|)earance of the mixe<l article a*» to regard real snlphiir with su»* 
picion, sometimej^ refusing to purchase it. The mixed article \% 
certainly, stomewhat more ewly mlBcible with aqueouB liquids^ 






SULPHIDES. 



287 



I 



The caU'areous prpcipitfited .sulphur yirlds n white ash (anhy- 
rlroihs calcium sulphate) when a little is hurnt olf on the end of a 
table-knife nr i^patula nr in ii porci luiu eruiihle. To aneerUin, 
exactly, the afutiuiit ol' the *iulphatc\ plaee « weighed quantity in a 
tarred }x»rcelaiiieruril>le, suid lieat until in unoie vapors an^ evolved. 
The weight of the residual anhydnnih ealeiiuii sulphate ((\%'^() =^ 
135J5), multiplied hy 1.204, is the aanaint of hydruuw calcium 
j^ulphate (t'aSO^, 2U^O ^ 170.1*) prewnt in llie original quantity 
nf calcareous stUplmr, 

Ift/tirfitjf'n Stf fph ifh\ Hydmmip h uric A Hd, ar Su fp h u reth- d Ihjdro- 
(fcn, — The preparation of hydrogen sulphide wa.H descrihed on p. 

\m, 

Ifydromitphidef, — Besides aaimoniuni hydrfisulphide, wliich has 
already been referred to on p. ItH), solutions of Nulphides and of 
other hydrosufpliide.H may l>e obtained by the interaction of hydro- 
gen sufphide with wdutions of hydroxides. 8odium sind pota'^siuui 
sulphiilep and hydrosidphide!*, Naj8 and K^, and NabH and KSsH, 
are the most iuiportant of these i^ubstaiices : 

2K0H -^ H,8 = K^ + 2H,0 
KaOII 4 IT,S =- NaSH + H,0. 

Like ammonium hydrosulidiide, they act as solvents for the areenic, 
antimony, and ntannic sulphides, rorniiiiir with them thio-i^1t». 
Tliey all di».««»lve Kulphur, prodiicing yellow Molntioos. 



Anaiyllcal Reaciiom of Sulphidei* mid Htfdromlphide*, 

To a gulphide or hydrosiilphide add n few dro|>e of hytlro- 
ehlorie acid ; hydrotren j^idphido will |irolmldy he evrjlved, 
ren>j[Tniz4ible by its odor. It" the Ril|diide is not acted iifKUi 
by the acid, or if free ?iulphur be under examination, mix a 
minute |M>rtion with a fragment of iHdi<i Bmiium hydroxide, 
Jiiid fuse in n silver <*apule (or old s;jioon). When cold, 
tila(^« u drop of dihile bydroelilorie acid on the fuj^ed nuias ; 
hvdrofren sulphiile is evolved^ and a black stain due to .silver 
sulphide, Agfi, m left on the silver. 

The moRt convenient reagent for detecting sulphide ia ammonia 
water in eu|»ric ainmimium snlphate, winch pives a black precipi- 
tate of cupric j*ulphide if a sulphide be present. 

Sulphur Itididt', S J„ (Nw//i/iwn> ladkhtm^ U, S, P.), has already 
b«'rn mentioned under loiline. A chhride, »^;C1,, and bromidf^ 
BjBr,, may also be foontHl from the elements. A mixture of sul- 
phur and 8ulp!iur chloride is ^imetimea met with under the name 
Itulphur hffpochloride:. 




288 THE AVIB MADICALS, 

QUESTIONS AND EXEEC18E8. 

lu wlmt forms does dulphur occur in nature V— State tht^ modes of 
l^rffninitioii uf tlic Ihnre chuvf commercial varieties of sulpbtir. — lo whut 
rt'^iH^ct dues thu atom of sulphtir vary iu qimutivatleiiee?— BtMrribp the 
|»rt'p!irutioii *jf hydrogeu >5tili>bidL\— Wlmt aru llie tlmract«rs c»f pure 
predpltatiHl fiiil]diur ?— (ii ve iiciuatioiis liXpUiiiatory i*f the i\'actirtns whicli 
<K*iur in prciKiriiig precipitated sulphur? — De^crilie the iiiicroiscopic K^t 
fur ealicareous prt^cipitatcd Hulphur.— 'Mention a methtnl of detcetitig cal- 
eium milidmte in preei|Utrtt4'd .sulphur.— Meuti<ni tlie lebta fur sulphides, 
and th« charui't*'r hy which hydroju'eu Kiilpbide is distinguished from 
other aulptiidas.— Huw are sylphidt'S insoluble iit tuids U^^tod for sulphur? 
—How would yuu detect a trace «f sulphide iu tmitDoiiia &oluliou8? 



SULPHimOtJS ACID [H BO ], AND OTHEE SULPHITES. 

Wberi siiljdiur in burnt in tbe air, it c<itiilnnes with oxygen u in J 
forms ftulpbunnis anliytlrKle, *SC\, uccasitmully, but erroneoUK!y» 
willed sulpIiunniH iwid. It m it ]mrigetit, cnlorlew gas, readily 
liiiyelicd on l>ein^ puKHiul tbrou^jjb a ttilie c<«dt'd by ^/reezinff-mh- 
Ittrr coiapost'^1 of two pnrtM *A' w*"n-}K)wder*'d ire (or of snow) with 
t)no piirt of t.'ointnoii Kult. If sulphurotis liiiliydride ia passed irit4> 
water, heat h evolved and scuiie «ulphitrt>UH at-id [H^SOj], 18 
uppiirentiy formed in solution. 

Hydrous stil|>buroUHaciiI ruiiy be iddaiued in crystals by freez- 
ing a conet^ntnited ufiuootii* stjlutiiJii, but it in xory unsUible. 

Quant ivafetwf^^-Thv acid rsidical of thi> f*u1|ihite,'< ia bivalent 
(^* VO- Arid i<ulpliide.% such ils atid |>otiiHsitiui nulpbite, KH?^,, 
and nornijil *^iilphites, stich its solium sulphite, Na^SO,, are known. 

^Vo/<*.^The !4itlp!iite'4 are so niiined m aer«»rdanee with the usual 
rule that Hiilts correspond iui? with aidds whose ntimes end io owt 
hiivi* a name eu<lin^^ in Ife. 

Experiment, ^To ?i few droj^"* of sulphuric acdd in a test- 
tube athi u piece of ehnrcoal und apply hetit; Pulphui'on.H nuhy- 
dride (mixed with curhoutr anhydride^ h evolved^ nnd may 
be eonveyetl throujili a bent tube into a small quantity ofndd 
water in another test-tube. Larger (juantitiefl of the gas? may 
be made in a tlask. The pHHluet is A^idnm SufpfniroitHvi^ 
IL S. P, ). It contains not le»s than 6 pereenl. of sulphun>U8 
anliydricie. 



2H,80, 


^ c = 


00, + 


2H/) 


+ 2SO, 


Sulphuric 


Carbon 


Cufbonic 


Wntcr 


9n)phiiroii« 
anhydride 


ACUl 




anhydride 





J^nlphurons anhydride nniy also be made by heatinir e<>p|H*r. 
mereur)% or iron with concent ntted sulphuric ncid, a metaHic miI- 
phute being formed* A]m> by beetling sulphur with dulphuric 
aeid* 





SULPHITES. 



289 



8alphidc8 are generally oiade by pa^iwhig sulphurous anhydride 
into fMilutious of liydroxidea or earbomiti^s, or iuto witter e<mtaiuiji^ 
»iK'h Buljstsmces in suspeiiKiori. Iji the eiise of earbinattw^ carbonic 
luihydride esi-apcs. The fonuubi of Hodiurn Hulphite {Sodii Suf* 
phis^t U, 8. P.), is NajSOj,, 7Hj() ; it oct-un* in eolorlesM eftiore«- 
cent prisms, soluble in water or alcohol. A» *'(uttwhhr'* it waii 
formerly UK^d for reuuning lract*8 of chlorine frotn paper pulp 
(»i>dium thioHuIpliate i.s now eaiployod). The formula of Sodium 
Bisulphite {»Sudii Bi^uiphk^ U. S, P.), in NaHSOg. Tluf t^j-ealled 
Bisulphite of Lime^ used by brewers for retardiiii; c*r arretiting 
fermentntioa and oxidation, and empluycd for varioui* antiji^eptic 
pur|K»rt<>4^ is made by passing sulpkurouH !in hydride, iSO-j, intotliin 
milk of lime. lU 8j>ecilic gravity varies from LO;'iL> to 1.(170, and 
it corresjxjnda to from 4 to 6 percent, of sidphuroiis anhydride, 
TbtJ so-called mf'/<j-i»wf//>/i/f/<^!f of ptilassium aiid tMHiium, used in 
photography^ are really anhydrof^ulplut<^H, K^S^O^ and NaySjO^, 
They may he obtaimHl by paA-ning sulphurou.'* anhydride into hot 
isaturated solutions *if pi>tassium and w>dium earbouat4."is, respec- 
tively, BulphiirouH anhydride is very soluble in alcohol. 



Analyticai Reactions of Sulphites, 

1, To a sulpbite (.Hodium sulphite^ for instance, — made by 
pii.s.Htng sulphonms anhydride intu {solution of scxlium carbon- 
ate) add a drop or two of dilute hydrotdiloric acid ; a pecu- 
liarly pungent odor is produced (sulphtirous acid). 

This CKlor w the mme as that evolved on burning Bulphur. It is 
due, prolMibly not to »ulphurouH anhydride, 80,, but to sulphur- 
OUM acid, IIj^O^, formed by the uni<>n of the !<ulphurt»u» anhydride 
with either the moisture of (he air or that on the surface of the 
mtieoufl membnmc of the nose. The gaa is highly suffocating. 

2, To a sulphite add a little water, a fragment or two of 
Kine» and then hydn>chloric acid ; hydrogen sulphide is evolved, 
rtt!o^-nizable by its odor and by its action on a piece of pa|M*r 
plact^fl like a aifj on the mouth of the tefit-tul^e and moistetied 
with a <lrop of solution of lead aceUite fa black stniu of lend 
leiutphide being formed). The presence of sulphurous acid in 
acetic acid or in hvdrochloric acid may l>e detected by means 
of this tent :- H^Si), -f 6H = H,S + mfi. 



Other Reavtions. 

To wparate jjortiona of a solution of a normal sulphite add 
barium nitrate or ctdoride, calcium chloride, and silver nitrate ; 
10 



d 



2ilO 




THE ACID RADICALS. 



in each case a white precipitiite uf a metallic sulphite results. 
The hiiriimi sulphite is t^uluhle iii diluh; hytlrixhlone acid ; 
byt if a drop oir two of chhjrinc watt;r i:^ iiri^t nddcil. ban urn 
sulphate is formed, which is iiisoiubie. The other jirecipitat^ 
are also soluble in dilute acids. Silver sulphite is derooiposed 
ou boiliug, Hulphurie acid being fornit'd, f^id met id lie .silver 
set free, the {ircei[jitate chirkeuiiig m color. 

Til reco^niz^' the tliree riidicids in nti sit|ue<HtK .Holutioii of syl- 
pliidcs, iiuli^iitcs, and .sulptiatfH, add l*iiritnii rhloride, titter, wad 
Wii^^h the precipitiite. Jii tli<^ fillrnti-, sutjdjidt's are detect*^! tiy 
the evolutit)ii *ti' hydrogen t^itlphidc uii the addition of aa udd. 
In thi* precipitate^ sulphites are de tee ted by ob.servin^ tiie tidor 
ors*ulphurous acid produced nn inldia^ hy<li'<Hddoric acid, and «ul- 
phatcsi arc detected by the iasoluhility of hanuai nulpliak' ro the 
acid. 



QUESTIONS AND EXEBCISES. 

Wlutt are th© diffbiren^ea tietweiMi fiU lplmn>usaeid nud siilpliurDua anil 
dride, sul|:>liit<'a and acid .snl|i!iiO';i'f — State tlii^ I'liHrnclers nf Aii1|rhiirolUI 
anhydride.— Htiw is the uffiritil siilpburutis ncid prepiired ?— H>' wliat tesli 
ni**y solphurous acid he. Tei'nj*n\/A'(\ in neotk afid ?^Giv6 a methtid by 
whieb sntphiies m&y be detected in pri^isoatx' of BUtphidcMS s&d sulpbitos* 



SULPHTJEIC ACm, H^SO^. AND OTHER SULPHATES, 

Many ffulphatee occur in nature. The mo«t important of these 
are hrmy i*pfit% barium ?iiilphate, Bwf^O ; gijpmm, mlcium *iulptoite, 
(?aS<)^^2HjO; jiad Efn<*tm »tiif, an^^rrn-Muni sul|doUe, .M^^SO^, 711 O. 

jWparfifion of Sn/j/huric Arid. — Sidjdiiir itt^idf, or irmre tiHiuilly 
tbc sulphur in iron jiyritirs, la UrA converted into *<ii]phuroU!* 
aidiydride by burning in iut, iind thix^n^i, by oxidatirtii in pn^Ht-at'© 
of nioiHtnre, is then converted into sul|duiric acid: St)^ * H^O I O 
= H-S( >^. The oxygen nct^essary to oxitUze the snlphurouii 
II n by o ride may he oV^tiuned directly from the atniuK|*bere, hut tlic 
proecss is a very slow one. The transference of oxygen U> the 
snlphurons unhydride, in preaence of moisture, to tlie form sul* 
phuric acid, is greatly husteneti in praetiee by the use of nitric 
oxide. This gaw, when mixt^d witti air, takes up oxygen to fnrai 
nitrogen f>eroxide^ NO, which, in turn, is eaj<ily r«?^hiccd iigain to 
nitric oxide by |>:irting with half it< oxygen to the moi^t ifulphur* 
ous anhydride. The nitric oxidi* so liberated reunites with oxy- 
gen, again forming nitrogen peroxide which again umiergoea 
similar reduction to nitric oxide, m that the j»rocet* l*etn>mc« 





SULPHATES. 



virtually a continuous one, a Binull proportion of nitric oxide 
j^urticing to convert relativt-ly largf (]imntitie.s of Fulpliurous anhy- 
dride, iixygen, and water iutrj j^ulf^hurie atid. 

The nitrie oxide i?< in the tirHt instiiiice ohtiiined from nitric 
acid, and this from j^>diuai nitrate by the aition of a s*inall quan- 
tity of ftulphurit' aeid* 

The foUowing e*|iiati<>nh reprewt^nt the ehief steps: — 

NftNO, f UPO, = NaH8(\ + HNO,, 

2fl,0 + 3S0, 4^ 2HN0, = 3H^^0, + 2NO, 

2NO + O, = 2NO„ 

UO ^P so. 4- NO. = H.BO. H- NO 




f SO, -f NO, = H,BO, H- 

^SSF*/tm/mr'/-.— The i4ulj)hurie radieal is bivalent (80/'), and 
acid aft well mk nurtnal sulphaten are known. Aeid potaH-^ium 
i»u!phate KH80^, in an illustration of the former, i^^^Mlium sul- 
phate, Na^O^, of the latter. 



Man iiffict lire of Sulphuric Aei<L 

Chamber Prorrm. — On the larjje 8cale, f^ulphurous anhydride 
together with nitrie arid vajNjr h carried hy uicans of flueH into 
large leaden ehanihent, where jeln of steam wupidy the necetv^ary 
nKji»tiiri% * and into which air is also jiassed. The resulting di kite 
sulphuric acid, w!iich collects on the fli>or of the chaaiU:rs, is 
drawi) off, and i^ eoncentrated Ivy eva[>oration in leaden, and 
finally in plasM or platinum, vcs.HetH. 

(hniaci FrffctM. — 8ul[diunc acid ik now made in s<une |dacpfl 
iin the manufaeturing ncale by aid of the r^iently perfeeted "eon- 
tact** process. In tjiis jtroeess sulphurous anhydride, SO,, lom- 
bine« directly with oxy^^en to ft>nn Kulphuric anhydride, S0,» 
when mixed witli oxygen ami pasjied thnmi^h tubes in wldeh the 
mixture \n expof^-d to a large surface of finely divided metallic 
platinum in the form of jdantiniwd a.^bet^tow. The snlf>hurous 
anhydride in obtained by roasting iron pyritiesand must be puri- 
fi«J in a uicwt thorough nianner from the hiwt traces af volatile 
ar»cnie c^m pounds and from isi>me other volatile coinpoundi^ present 
an iuipuritieti derived from the pyrite»: but it remains mixed with 



« tti ilie iibAence of • nuffleient supply of water vapor, a whit** ery«tiilUn<? 
■utittiinco. niiftj-aulphmik aHd, B<\ JJJ]^, may Ixj prfMiiK-ed (iKimctimri* cnUrit 
"ebnnilMf rryntjiU"t Tht" mHiiufiicturtr of ^nlphiirlr acJd laken plcp« in 
MiMtin; thu prcM'ticf or so mut-h water v^pur thnt tlicHc t'lyfttals arc* never 
ft>rme<I, Tlic foUowiti«r iH|uattoti* ropreser.i tbc rommUon of nttru-ftulphontc 
tct«t and lU iJf<roitirMi«^tloii liy water:— 

1»0| i 8NOj + UiO - 2HO, - 5|qj \- NO 




THE ACin RADICALS. 



cousidenible quuntitias of oxygeti and nitrogeii from the air drawn 
into the funiare?^ in vvbiib Uie [pyrites «re rousted. The ctHjled 
mixturt* t>l guscn h then bnm^lit ii^ thoroughly as possiblt^ into 
contact with j»hitiiii/.ed ashseto.s plitccd in I rays m njirighl iron 
pipe!?. To lic^iti with, thest* j>ijH':^ are beatai in order to Miart the 
coiiibinatioii; hut they are silterward exposed to the cooling 
influence of the extenial uir, the heat given out by the occurrence 
of the reaction being aiore llian Mufficient to maintain tlie tempera- 
ture at the poijit lit which the miixinimn yield ol Hidpliuric anhy- 
dride m olitained. 

The «ul[)huric anhydride produced by the reaction h pat^jfed 
into previonsly prepared 1*8 j>ercent- i^ulphuric acid in whieii it is 
rajiidly Jilysurlxd with formation of pyrosulphnric acid, H^S^O^; 
and the bitter is then mixed with tlie (juantity of water necessary 
to reduce it again to the conditon of ^»8 percent, sulphuric acid or 
to sulphuric acid of any required concentration: — 

Ferric oxide may be used as the contact substance instead of 
pi a t i n i xed asbestos. 

Othrr proc€S4ejt,—i^u\phiiTic acid may be obtained by other pro- 
C€»ASi^, an by distilling the ferrons sulphate remilting from the 
natunU oxidittion of iron pyritew by air; but it i^ not so made at 
the prcHfut day, FerroUM Hul[*hate wa.'* fomierly called ^rfen 
ritriol^ and the distilled pn>duet w;is called oil of viiriol in allusion 
to ita consistence and tirigin. 

PurificatiotK — I'onimercial suljihurie acid, prepared by the 
chamber process, nniy contain arsenic comptmnds, nitnms com- 
ponnds, and shUh (lead sulphate, etc.). Ar^^nic may be detei:te<l 
by the hydrogen test (p. 179), or the stannous ehloridt^ lest (p. 182), 
nitnais cionpounds by means of powderwi ferrous sulphate (which 
ittxptirew a violet tint if they are [»resent), and aalta by ohserving 
the re>idue left cm boiling st^nje of the acid to dryneevt in a cnici- 
Ide in a fume-cupl>oard> If only nitrous comjxiunds are present, 
the acid may be purified by beating with idiout one-half per* 
cent, of ammonium sulphate— water and nitrogen being pro- 
duced (Pelouze). If arsenic compounds l>e present, heat with a 
small (|uantit>' of nitric acid (or sodium nitrate), which converts 
arsenoiis anhydride, As^O^, into arsenic anhydridcj As,0^, then 
add anunoniuni sulphate, and distil, on a sand bath, in a retort 
containing a few small pieces of quarts, or of platinum wire or 
foil (to prevent ^'bumping" — nee p. 2*57). The ar^nic anhydride 
remains in the retort (arsenous anhydride would be carried over 
with the sulphuric acid vapors). Tlie distillation frees the acid 
from other i^alts (such as NaH8f)j and Fb8<)J which are not 
volatile* Lead may be det«fcted by adding to the concentiBted 




I 






SULPHATES, 



acid a few dropa of hyflrochloric acid, i>r a crystal of sodium 
chloride; the lejid chloridt? prt'i.'ipltiitod give^ a peculiar pearly 
opdeaeence to Ihe llquiiL 

Pure jfuijthurk aeid, Hj*SO^, Ua^* sp, gr, L833. The best **oj1 
of vitrior' of eoniDierce, a CQl<jrlefeS liquid of oiJy cnijt^istence, has 
gr. L82t!;i, and contains ahout 92.5 perceut of liydrogen »ul- 
kt€, The latt^ff h Acidurn Sulphnritytim^ U. S. P., Aeidum Sui- 
phuricum /Hfufam^B. P. (^p. gr, l.OtjT) toiitaitis about 10 percent, 
of hvdrogeuttijlphate, A^ldum tSuijthnrirmn Aromatintm^ U, 8. P. 
jp acid diluttil with alcohol and iiiixc<l with tincture t>f finger 
ind oil of cinnamon, alrt^j contain:^ about iiO percent, fif hydrogen 
sulphate. Ar<miatic sulphuric ficid may contain snlpliovinic acid in 
Tarj^ng quantity, dependent U|>on the internal and external 
teni|H?rature during and subsequent to preparation, the age of the 
Hjtniple, etc. Tliere are ty>n!e dchnite conipoundK of sulphuric acid 
witli water; one of thest^ (H^SO^, H^O) may be obtained in crys- 
talH. 

tSa/phuric nnhtfdrifie^ SO^, occurHiii white cr^'stab which interact 
with water with great violence, and prothice wulphuric acid. Aa 
well as by the dirwt union <if suli>hiirouH anhydride and oxygen^ 
it may be made by dij*tilling sul[>huric acid with phoaphorie anhy- 
dride: l\p(\ -t iV^^ 2HP(), + JSi\. It uniti^ with sulphuric 
acid to form ''fuming i*ulpharic acid" or pyrmuljihirk ueid^ \\^^i\^ 
formerly made at Nordhnusen. in Saxony, by distilling partially 
dried and oxidized fcrroas sulphate. 

Noi€. — Sulphuric acid is a most vidnalile compound t-o all 
cbenii^ta and manufacturer» of chendcal HubHtancet*. By ita 
agency, direct or indin*ct, a very lar^e number of chemical tran»- 
lormatioDS arc effected. 



^ 



Anaitftkat li faction of Sulphates, 

1, To a solution of a sulphate add solution of a barium 
salt; a white precipitate of barium mi!|duite, BaSC\, is pro 
duce^L Add nitric neul and laiil ; the precipitate doe& not 
dissolve^ 

Thia reaction 19 as highly characteristic of Hulphatea as it hast 
lieen stated to be of barium s*altH (iter p. 110). The only error 
likely to lie made in iU application in tliat of overbooking the fact 
that barium nitnite and ehbiride are le-*«M Holuble in concentrated 
nitric (or hydrochloric) acid than in water. On adding the barium 
salt to an acid liquid, therefore, a white precipitJite niay be 
obtained^ which if* Himply barium nitrate (or chlorideK The 
appearance of mich a precipitate diflern considerably from that of 
the barium f^ulphate, but ^^hould any doubt exi^t, water may be 
added* which will dinsiilve the nitrate or chloride, but will not 
the Bulpbate. 




294 



THE ACID RADICALS. 



% Mix a fragment of i\\.\ insolulile i^ulphate {tJi. BaSO^) 
with fMitassiuiii i>r sodium corbomitej or, l>ettt^r, with a mix- 
ture of both cur bona tes, ami fysf in ii snialJ crudble. Digeut 
the resii*liiei when cijld^ in water, ami filter; I he tilt rate may 
be tested iur the suliihurie nidiaiL 

Thirt JB a I'onvenit^iit iiiethml of qualilalively analyzing ins4>lu- 
ble MulphateiH, such iis tho^e iif biiriuiu ami lead. 

3. Mix a fragment of ao in>«olub]e eulphate with sotiiunj 
carlxjuate on a piet^e of charcoal, takin^i: care that some of the 
charcoal dust b included in the mixture. Heat the mixture 
in the blow-pipe fiame until it i'u&c% and, when cold, add a 
drop of aeid; hydrogea nulphide is evolved, recognizable by 
itii o<h>r. 



TliLs is another process far the rcH^ojjjiiition of in?«(>lnhle Mtilphale?*, 
Dtlier prepanitions of sulphur, and nulphur itself, give a siuiilar 
rt.-^nlt. It is tluTetlire rather a te»t for sulphur and its compounds 
thiin tor sulphate>4 naly. 

Atitidoft's. — In cases of prnmniing: by f*u!phuric acid, si*hilit>nof 
Hcidium carbonate (comnmn wai^hing mdn), magnesia and water, 
etc,, may be adminiHtered ils antidott*s. 

Thiosulphuric Acid, H^S^O^, and other Thiosulpbat^s. 

The only thio^ulphate of much intere^tt in pharmacy is iiodtum 
thiosulphate, Na,S/>,, olI/> {Si*dH Thifmiiphm, V. S, P.). It 
waj< formerly known as indium btjpo»niphiir^ and ia nned in photo- 
graphy under the name uf **hypo," (True hyjioj^ulphites are now 
known, e.y. Na^S,<>j.) 

Thit)«ulphates irjay be regarded a>4 jf^ulphnt^^*!^ in which one-fourth 
of tlie oxygen has been rephiced by sulphur. Thiomiljdmric acid 
has not been i.sotattHi. 

IWpartiiion nf mdlum thmtntipha/e. — Heat together gently, or net 
aside in a warm place, a mixture of wlntion »jf siwlium nulphite 
(Ntiy^Oj) and a Httk^ j-mwdered sulphur ; combinati<m slowly takes 
place, and sfuiinin thiosulphatje i» fonii(»d. The solution, filt4?re<i 
from excesis of sulphur, readily yields erystals. (The sotution of 
sodium sulphite may l>e made by saturating soiutitm of sodium 
hydroxide with sulphurous anhydride.) SfHlium thiosulphate i» 
obtained on the manufacturing scale by the interaction of Aodiuni 
pulpbate with the cahium thiosulphale formed by the action of 
atintwphcric oxygen and carlM)tnc anhydride on the want* cal- 
cium sulf>hide from the Lebhinc sodn pnM^esa, 

p0rA of nodium thiotfulphjtt ht tpuiidihiHtr iinol^m*, — In the 
Pbarmacopieia, sodium thiosulphate is given as a reagent for the 




PEHSVWHATES. 



295 



^ 



qiiantitJilive (ietemuiiulion nf trie iodine In volumetric iiriiily«J.H. 
To H tl vv (lr<»]>H ut iodine dilution mid enid nUrcli nmeilage ; a deep- 
Line tolor (stareh ioilide), is jinwliieed. To the prndnet add sidu- 
lion ot' !si>dinnj thit^sulpJiitle until ihe blue eok»r just iJiNi[*pears. 
Thi.s reacliuu is j^ndieienily de Unite and delieiite to a<imii of tjppli- 
cation for «|Uiintit4itive i»ur[>o»ct^. It depends on tlie CDinbination 
of inline witli IjuJf of the sudiiini of the ihiuHuljihale Ui form sodium 
iodide, whiJe widmru tt'trathionate, Nii^S/\ (Ironi rirpa. Mm, four, 
lUid Orioi, thcionj hulphur), hi furmed at the iwiaie time. 

2Na/^,U, + I, = 2NaI + Na^S^O, 

Use of *'Hyj}0*' in Photography, — SotlUim thiosulphate ia 
largely Ui^ed in photoj^^rapliy t*i dbmdve silvt^r rhloride, bro- 
mide, or ioilide off' phiteswliieh huve heeuexpn.Hed in tlie eanitfra 
auil devvloiM'd- I'repare a little of silver chloriilr l»y uddhtg 
a chloride (^otliyni ehloricle) to n few drop ot^nolutioii of sil- 
ver nitrate* Ck^llect the j)re<'ipitat**d (*hlori(ie on a filtt^r, 
wn^h, and udd a few dro]>H of solution ofsodiuin thiasulphate : 
the silver mlt dit<'*{>lves, .^olntkm of j^udiyrn silver thios^^nlpbate 
l^ehi^ formed. The .dilution of this thiosulpliate has a re- 
markably sweet taste, sweeter than synip il' the solntion is eon* 
eeui rated, i^oilium gold thiiisnlphate haH l>t*eii employed for 
giving a plea^iiut tint to photognij^lde printj*. 

Te^f, — Tos(dution of a thiiw4nlphn(eaild a few <lrop?4of ililute 
gulphuric or other arid and smell the mixture ; thiosnlpfiurie 
and IB «et free, but at ojiee Iiegitis to deeom^Kjee into 8ul]duir- 
ouH anhydride, refx>gnizahle by its odor, free sulphnr, and 
water ( H^O, r SO, + 8 + nph Another test ti>r a 
tlnosuijdjifle in solution is its jMjwer of dit?9ohnng silver cliloride 
with productiou of a more or less sweet liquid. 



PERsiiLPnimic Acid, H,??,0(,, and othkr PERflULPiiArm 

rcrsnlphurie anhydride, 8,0,, was obtained by Berthelot in 1887. 
It yiehlM a solntion in water whieh proba!»ly eontaiiis M>me persul- 
phurir acid but ^»m deenmpof*es giving oxvjxen and sniidniric acid. 

Hf*lt« of persnlphurie ueid was first ]»re(>itred by JT Mnrshul! in 
18fU, potassium persulphate. K.,S/>^, and ammontnm persulphate, 
(NH^L^O^, being obtained liy" t!n? elertrolysis of saturated soln- 
lionnof poUasiuinsiilphatennil of;immoninin nidphate, respeetively, 
in dilut*? sujphurie a<id. Hnrium pen^nlphnte ran be jirrpared by 
the interiictinn of barium hydroxirle with n sjitunited sfdutiuu of 
ammonium persiiljihate aad evaporation of the j^ohiliou in ranto. 

The pf rsuljdiiit*^ are of ftimie indnstrial importunee as blriiehing 
and general oxidi/iing a}<ent,s and in tiie latter capacity they serve 




^^ TBE ACID RADICALS. 

^\^^^ '^'z*^<*^ :i Jsjenii-a; inalysisw Their solationfl dis- 

-yTi -iT-jjUi* jicCxjs. sutii Je^ ii2c. ouhnie^am. xlaminiam, copper, 

V^-^^£^^«^" ^^ -'"■liii'.a I'C ART OS. soIphAtts being fonned: 

;7^_ ^^: . = ^^a5*>'^ — *^-V Pocawum penmlphate was 

2*iz 1.7. a utr 2L^-xr: s ise naicjy... an.ier the name uf-'aDihion," 

*^ * -^. 7' --i^^i-2ii5 c li :ii..&.«ttiij. A purp*j«e fV.r which it i», 

i« '»•: :;-. :iiijc ijiac-U-Tw. Ii s ^-iifin^Iy 3»..iable in water. Ammo- 

a-ui .^:><i^ai4::c i^i^ A:a4. r^Gaiiuatrru-kj.pUoalion in photography 

la' A Tvii- ■-. 5t>^. ,:^ i^rscIioAre is obciined by the action of 

^J^ |-^ "^-"Lr" f^'T"" "^ "^^^"^'f^r^ p^r^Lphate. or by the electroly- 

^> . . A SI r^ricc-i 5*. LiZ' c . z 3fc::-i ii^iiiyi: sulphate : under the name 

;:«:•>*. •!_::«: az j*::ie.cs *.I*s.« ...t :he salt has been introduced 

Ai'dtr-t-u S.-'f-^ifut ir r^rrtH^LXiiTf*, — In presence of moisture 
7«;rsa. rOiiis rr:i':v:;i_y i'-o<i:rr«5e wrth r'-nnation of Ailphate and 
r ■ trr. c c :i-r:^ ^.-.'^ ~ ^*^ = 4KH:?t\ — 0,; con- 
^•■-■- -■- •' ::^" sc <•!:;:;• Trf, :i=Je# freshly prepeired horn pure per- 
> ■ :.t:: ^ r 1 vi Tc r:^i.':r:ii».a (he additiiio of barium nitrate; 
■-"; > '-~ ■"> xvt X :rfv:r::a:c ot sulphate slowly, on boih'ng. 
- :•- :- • : r: i,:i ;> .:-:\-. r:p«.t<ei*l..wly in the o»ij but rapidly 
; 7^^* V" ^ :ji :v _:-: c -r* cal.ri'ne. K>,U, - 2HCI = 
:\:'.>\ '/.. — ? iji^^-uz; :-«i:'i-r is s:miidr!y deconij)ose<l, 

^ * ■'•-'■•■ :" ■ ii-r-.. — ^vi': h'jHc a*:id. on wanning, causes 

* "•> • " '* v.\r:r. ini '.ii r.e. — Ferp>us sulphate is con- 
• ■: : ■ - ; > : ■ >j:^. rh-e **Ii2Ci"n bev^.^ming dark reddish 

■ ' -■ -^v. -. K;^\ - iFtv^\ = Kj5M.\ . Fe.(S^).)3.- 

■ . ^ :- -s -^ ■ \ ji-\ :•• : :■ v iv.:-.!. silver nitrate pnxlui*es a ni<»re 
- v< • -i..' :"/.."< y:^v::'::a:c .^f the silver salt (AgH?^)^) of 

* • -^ "v.-.^ : ».'i.-">ji^- i. ni'-aopeRiuIphuricacid.Hji^OJ. 

V '. -.. v. •*..•><«* :r. -rLur-tiry if sulphuric acid libera tiii 

■ • \: ^ — •': • •^■- -.r-ii'iririhy meansof|K>tassiumhydn)xide. 
S ■ • -V;.: :" r.:.u!.* »•:* the oxyaciils of sulphur 

» '" -■ s T^ - :^ ' * •.: < .s •.:^r^l .ss The ^.nes i>i ii>mj»*»unds o\' nit- 
■>:. • * • : •\\j;-- .;a>::^:::u- l\ilvu*s law of multiple proj>or- 



V, 



, • . . H>V Piihionic Acid . 


. HAO. 


. . H,>*.\ Trithionio Acid . 


. H^O. 


V ■: . H.>.v\ TetrathioiiicAcid . . 


■ H/?.0 


V. : . H;>.V\ Fviitathionic Acid . 


. H^^.O, 


r -::'::;:;-. A.:d. H>j\ 




^•v- ;v:n:::: h:iric Acid; H^V 





^^ ■ \\c A ^hori article o» 



CARBOyATES, 



297 



salpharic add. giring eqoatiotti.— D<nr m^y nitnyus eovpomidft be dcU^ 
UhI in, and eUmioaUMl from, ftilpliaiie madf—BlmUf tkm mt^hodm for 
dtt(M!tltig mjabSkic in satphurk wad^ mad vxplalii Hire piwju ii bj wtikli it 
may be removed.— Define solphatei, acid nlpbateii, aad double mly jiatea. 
^What perD&iitag« of hjrdrQC[ea iMilpfaaie ia ooolajAed ia oil <(f ▼ttfiotf — 
By whal prtioeH is tnlphunc anhjdcide obtatodd fkoai ^trdmmrf Mlpbiuie 
acid f^Exrdain the r«aciiuiiA which occur in lesUiig Ibr Mlpbatea, — Ckktt- 
Lite ihe vreighl of salpburic acid, oiMSJb percent^ tuseamry tor the pvn- 
d uctioD of one ion of dry ammoQiam solphaU. Am. 171d Iba,— Xaioe the 
antidotcn In cwat of poiaoning br mlidiarie acid.— Iliiurtia&e bj an e^ua- 
tioD the pnfiaialieaof widiiun ihioaaiphate,— Mention the chntncSenfCac 
reactions of ■odium thioaolphat«:.— Give tlie namca and fanmtUm of ten 
add^ each t^frf|»i"^c hydrogen, «tUphur, and o^^en. 



CARBONIC ACm [H^COJ, AND OTHEE CARBOHATM. 

Ot^urrefkm ^tmd wtttieties o/Chrbom^ — Carbon in u ri<ii-iJtu« iii of 
all living ofipuuma, and the blacfceniiig wkicb La obt^rvt-^i %U*tn 
p[HJkt or animil tJMmia awl tine n^ontj of the nuuix ]ir«j<iart^ 
obUiined from audi tMiBi amsfidcntlj strongly heated, i« du^' 
to the j^paratioQ ai mthtm m a OMfv or lev pure fofm* <>>k'\ 
chiircoal^ iioot, laap-Uack, idkt,, eoMit of anifthofoiia cartr^rj 
mixed with var7il^^l|lUHMilMM#«iMBl w other impanticnderiT«4 
from the mateiiala hvm «hidh Iftne iirtirtMMo hmhccn AirmecL 
WUen coal or worjd b Ml|pselei to 4fj JMIkittw ^ |^« 1^1) hi 
irfiri retorts; for the prp parafSo a ^ oH^Bi% ^B^ cf 
water and other V' ' iWEU 0m^§Jmit mmaA \ 

anhydride, and ciiri ' ^% M^lli «MS oiMda oHmhV am 

given otf in eonsiderahl^ ^|ia»litjr '■Idk 4ie mu^m MMortkis nf 
the nirlxm of the coal or wood mMiap Ib dbi i 




id the re^i*Uie olitained on Muhjecting ilried hotiee ti» • f^ b^' 
without acc'ess of air. It is a mixture «jf about 9 patf* of 
minerul with 1 i>f ourbonueeouR malter. The opefmlimi lanr 
Ih^ rarried out t)n a Hiiiall scale hy heatin^^ a few fn«rm<n<ii/ 
iHMie in a covereil preehim crneible in a funie-eupbowdttftljl 
smoke and vajKir are no lonjrer evolved. Themincil] 
may l>e removed and puritied animal char^MNil (Qmt^ A 
malU Penfirnfuj^, IJ, H, P.), obtained a» IblWt 
l>ow«lered animal charcoal with a mixture <if 
t^i' bydr<H'lrh>ric acid and four timc^ iu 
iiM Vmilin^j^i^nd filter j again boil ck 







298 




THE ACID RADICALS, 



flhoulil not yieli] more tbiiu lU p^rceut. of inoMiirtMvhfcu dried 
at a higJi tempemlure, nor more ihuu 4 jjkerceoL of ^\ when 
tlioroyghly iudiienittML Tbirty gniins well shakeQ witli 15 
ouuces of tlistilletl water cootaiuing U.0l>5 pereeuL of urdiuary 
commercial carnmel {tice Indexji should remove at least four- 
fitths of the color from the li(|uid. (Hutlgkiu, j 

Wimd Charcaaf {(Jarbo LUjni^ U. S, P.), i** a wood isimilarly 
iguiled without iicct\i« of air» On incmeration it ahouid yield not 
aiort* tiiaji Tj jH^rcent. of ash. 

Ilfvolorhitiii jtowff of Anifiial C/itircoai. — AuLmal charcoal, in 
fcigiaeiJte i« cuipluyed ia dec^lcjriziiig solutiuiis? of eomoion brown 
sugar, for the produetiou nf white su^ar* Its power, in id the nearly 
equal iniwerofaa e<|uivalent cjuantity (j^gth) of the purified variety, 
may be demons^traied on tt<.>lutioJi of litjnus or logwootl m well a^^ 
on t^ohition fit caruineb 

Ik'^idet* tlie.Hi- smiejrphtnis Yarietiea of carbon there are two erva- 
tidline varit'ties ; moiiely pivmbuffo or bhrk'ttiad, the materiiil 
employed in making the eoRS of the so-ealh^d 'iead" peneilj*, 
which cry^tidiizes in hexagonal plates, and fimtfumd wliieh cryj*- 
Udliz-eM hi I'orms beloagiag i*^ the cubic fivsteni. Diiiinond ia the 
hardest Hiibstance known. When any form id' carbon h burned 
in oxyjren, carbimic aidjydride, (*n„, rt^ult:^. 

(Jarixmiites are very common in nature, calcium carlK^nat^, 
CaC*0^, being widely distributed i\s cloilk, liiiie*^nm% and marble. 
Hydrogen cariionate (tnie carlH*nie aeid) is nr*t known a» a j*epa- 
rate snhfttnnce, bnt a sc^lution of ciirbrinic anhydride in w*ater 
appears to contain wime of this acid. Such u wdnfion (nfe below) 
einmjjres the eidor of blue litniUH-paper, luit tlu' ehanjze is *inly 
teinpfirarv', a*< the Ci*rl><inic acid decomj>oses into water and ear- 
lionie anhydride when the paper if exposed to the air for a short 
time. 

fhrhotii'e anhifdrif^e, (*(),, is a product of the conibnHtion of all 
carlxmaeenns matters, and tifthe respiratir>n of aninvaband idanb*. 
It is a constant constituent of the atmosphere, in which it is 
pr(?sent to the extent of about 3 parts in 10,OflO. and throughout 
whieh it IS very equal ly distributed by diffuHwn ()*rr p. fJO). The 
pr*K."ess of carbon assimilation in the ve^et4^ble kingdom is de|>end- 
ent upon the prejience in the air of this smal! piropf»rti*»n of 
rarhfinie anhydride, ami it takes place by the aid fif chlorophyll, 
the jifreen eolorinpr matter of phmts, under fhe intlui'uee of direct 
sunlight. The aeeumtilation of carbon ie anhydride in confined 
air, so jw to greatly excee<l the proporti^ai jnst mentioned, gives 
to such Mir iin crowded r«>oms, for example) deyirCK^inpr effect; 4 
or 5 percent, rendering the atmnsphere pxdwamus when taken into 
the blood from the Inngs. Carbonic anhydride (or carbonic acid, 
which 18 prwient to some extent at least in nil aqueous nidutious 




CARBON ATE&. 299 

of carbonic anhydriclf) may, however, bt> Uikeii iriUi the fttuiuach 
with beuelicijil seiiaLive vH'ei'ts ; lienci*, (irohsibly, much of the 
value i>r such etlervescing lk|tji(LH us acnitctl v.iitrr {^il'ten wroTi(j;ly 
e;ilie«i i*«jda- watery, leuiLUjade, s^tlutuins i.if the vnriou?* ^rajuiUited 
prcjmmtionfi und eflferva^'ing powdcrn, juid t vcii iiotush- water aud 
soda-water pmperly fto-ealled. Tbi' gan Htpiefie.s on the uppUea* 
tioij of KUtheieiit pressure at tcaij>i*ratur<."s below ^l** C. , and the 
li(|Utd !ic:>lidifieM when still fnrllier eoolwl tu — ris° (_\ The relaitive 
ut'ight^ of equal vfduoH'H of tarlionic anhydride, air, and hydro- 
gen, ttre nt*|iL'ctfully 21.89, 14,44, and 1. At ^>rdinary teuipi-ra- 
ture8, water diiViolveH about ite< own volume tif larbnnu" tiuhydride^ 
and the weight of thi,^ ga» dis^Holveti under inert aned i»rc*«Hun? is 
pn>pcirtional to the pre:^.Hure. An averajLT*' bottle of ai" rated water' 
contaiui^ alxnit tive tinier the *juantity of earhonie anhydride whieh 
the water could dif^dve without artificial j pressure, and when the 
cork or stopper h renuivcd, alMUjt four-fdlhs of this ipiiuitity 
i^^rapen, while the balance (aliiait etjual in volnnie to the volume 
of the water) remains disHoIved, 

The carbonic anhydride used in the manufacture ot' stHlium 
carbonate (the curbouate mo»t frei|Ueiitly used in medicine i*nd in 
the htU generally) is obUdned by the decompf*sition of calcinm 
carbonate (^«r p, S7). 

(hrbonif Oxiih, CO. — Heat in a tei*t-tube two or three frag- 
mentu of jMit^s«iuiu ferrocyanide with eight or ten timi-w their 
weight of Hulphiiric a*'id, and as ^hux as the ga^ k-giris to Ir* 
evolvefl^ remove the test-tube from tli<* tlanie, as the ai^tion, when 
once Hi«t np^ proieetls sonuwkat tumuttmaisly. Ignite- the ear- 
Umie i^xide at the ue»utli of the tube ; it burns witb n pjdedilue 
flame, the prothut of combustion laing carbonic anhydride, t'O,. 
C'nrlKmie oxide may also bt> ohtiiined fnmi oxalic acid {net p. 
804). 

CWbcmic oxhle is a direct i>oiH<in. It is generated whenever 
eoke, charcoal, or coal burns with an insutticietit supply of air. 
Hence the danger of burning charecml in braziers (Htberwise than 
under chiuineyK) in the more or lesa closed apartments of ordinary 
dwellings, 

Phiatfrn.—e.tiThin\\ii oxide unites with ehloriiie in sujdight to 
form phmgen {<?*.>, ph*'**, light, and -m liM, (ffhnn/*, I iiroduce), 
CiHX, a efdorbrs*^ liijiii,! which interacts readily with water, 
rorming hydnwhloric aci^l and earlKiuie anhydride^ CO f Cl,= 
COCl, i C(X1, 4 H^O = 2HCI 4^ CO,. 



^Hiitth'd H«"mtM watf^niyi^ld farhonic anhyclH<l*'» ttnimlhioasly wIjpu 
new, and soJiTi htM^^uie "flttt," hut yii»l*J it Una niiiliily *iu<] more contimi- 
«aiHly wlii'fi olihir, hihI then retjtia rmlHt*'mlmr|iio'SK longer, Pto^nity 
thJi* iii diie to ft fttilntitjii nf trae rjirhnnic a/^itl lH*<'Oi] hei«K b*-* uustiiblc 
tlittn a mew Nolativn **f tli*' its^**, ff^, 



3(X) THE AVID RADICALS, 

Anahjilciil RcaetioitH of Carbonates. 

L To a frat^niient of iiiiirble in a teaUube ftdd dilute 
hyilrochloriu aciii ; curlxniic anhydridt^, ('O.^. in evolved, and 
may be convey aJ into water or tjoltitiouB ot'sidts by the usutil 
delivery-tube. 

Thin ii* the proct-iw usually iidopttHl in preparing cjirbunic aiiUy* 
dride for e.xjierimeiitiil purpii^cH. On tlie large seiile, the giL** is 
prepared frrnii chalk <»r marble and sulphuric acid, frequent stir- 
riug priiiiKitiug iU liberjitiou. 

2, Pass tbe gas into lime-water; a white precipitate of 
calcium carlioiiate^ CaCO^, is producetl Solution of lead 
subaceLate may be used instead of lime- water, and is fierhapa 
even a more delicate reagent* 

The ei^olution of an tKlorlesa gim on the addition of an acid to a 
Hjdt^ heat bein^ applied to the iidxtnre if neeessury, and the form- 
atUin of a white prwipitiite wlu^ti the giis is passed into linio-water, 
atford sutlieient evidence of the presence of a curhtmate. The 
preneiu'e of carbonates in sr4ution8 of alkali-nictid hydroxides 
may be detet^ted by the addition of liine-water. CarboiiiUei* in 
preaenee of nulphitei* or thiosulphatCH may 1h> detectetl !iy adiling 
ttcid potaii^siuin tartmtt^, which dec(>nip*i*<t*H carlKjniit4^ with erter- 
vciR'euce, but does not attack sulphites or thio»iul|>hjiteH ; or the 
»ub«tanee iin<liT exaniinati*»n iiiiiy first he nnxnl with execjw of 
potassium dichromate, aud dilute sulphuric or hydrochlorit" acitl 
be then aihh^d* The evolution of sulphurous anhydride, from the 
decompoiaition of any **ulphite or thiosulphnte, i^ entirely pre- 
vented by the pre-^ence of the dichromate (which wradd immedi- 
ately oxidize it tn s^idphuric acid) while the evolution of cartionic 
anhydride is not interfered with. 

3, Blow air from the lunir*^ through a plass tube into lime- 
water : the ])re-sence of carbonic anhydride if^ at once indiciited 
Ivy the liquid l»ecomiug turbid By parsing a considerable 
rjuanlity of ordinary air thnni^rh lime-water, a similar effect \s 
prtMluced. A iKittle containing linie-water :44M>n beromei* inter- 
nally c^mtecl with eah'ium carbonate owing to ni»8or][)tioii of 
ntmospheric carl>onic anhydride. 

4, Fill u dry teat-tube with ciirbonie anhydride, pas^in^ thi^ 
gag, by meaiis of a delivery-tube, to the lM>ttom of the tert- 
ttiln^ Beiug rather more than one and a hal( times a.** bejivy 
aa air (sp, gr 1.529 >, it dis*plaeeji the latter Prove the 
presence of the giis m the test-tube by pouring it slowly, aa if 



CARBONATES, 



301 



a visible liquid, into aoother te^-tulie containing lime-water ; 
the cburaeteristic turbidity is oijtaioed on shiikiug up the 
lime-wuler wiili the air of the tube, lu testing for eurbonates 
by briuging the evoJvtnl gas into coutact with lime-water, the 
|)reparatiou aud adaptation of a delivery-tube may otteu he 
avoitletl by pcjuritig the gas from the geuenitiug-tul>e luto that 
coQtaiuiug the limi-svjiter, in the maimer just indicated, 

5. Pa.s8 earbouie auhydride through lime-water until the 
precipitate at tij-st formed is dLisoiveiU The rej^ultiug liquid 
18 a eolutioti of ealeiuui carbonate iu carbonic acid water, or 
probably calcium bicarbonate, CaHj(CO^)^> Boil the boIu- 
tiou ; earlwnk anhydride escapes, and the carbonate is again 
precipitated* 

This experinjent serves to »how how calcium carbonate h kejit 
■ill 8<jlutiQn in ordinary well-waters, imparting to them the prop- 
ty of "hardness/* and how the/wr or stone-like dejwsit m tea- 
^kettle«i and boilers is formed. It should here be stated that 
calcium sulphate also produces hard«esH, and that odcium 
carbonate and s^alphate with small quantities of magnesium car- 
bonate and sulphatt^, cnnstitute the hardening ct^nstituentw of 
well-waters, a card (mleium or nuignesium oleate) lieing formed 
whenever soap is used with such waters. As the formatirm of 
this curd indicates the tbrniation from the soap of ins^iluhie 8ub- 
titances which are devoid of detergent properties, it is obviously 
inj[x>rtant, in order to avoid waste of fwjap, that water as free «« 
jMi«sihle from thest? ha rdeninp; constituents sh^mld he employee! for 
washing purposes. The hardness |>nxlueed hy the ealeiuni aud 
In^^rnesillm carlM)natc>i is ternicil *'ti"mponir}^ hardness/* because 
removable Vrv ehullilina ; that prfxlueed hy the snlphates "perma- 
nent hardness," becrtus«> nnaffrctcd hy ehullilion. The addition 
of lime- water, or a mixture ^if lime and water, removes tempor- 
ary hardness, Calt^(('(>,!^ -f f'ufOH).^ = 2CnCi\ -f 2H,0, and 
sodium carbimate, "washinjf-soda.'* removes both temporary and 
jiermanent hardness, in the latter caw^ sodiuni sulphate reraaiiiing 
in ^)Iutton, Barium earhoiiate (p«m'dered witherite) also deronj- 
poses calcium ttud raapnesium suljdiates, hurium sidphate tiein^ 
pre<'ipitfited and calciuni and mageesium carbonates formed; the 
latter and the carbonates originally presc^nt in the water may then 
l>e precipitated hy ebidlition or by the action of lime-water. But 
the pfiisrmous chanicter of barium salts prevents th<^ use of barium 
carbonate to purify water for drinking purposes, as by uccident 
Of an unforest*en reaction a portion rnigld become dissolveil. 

6. Add a solution of potaeeium or sodium carbonate to a 
tnagnesitiiD salt ; a white precipitate of a basic magDesium 



THE ACID RADICALS. 

earbonate m produced, hut the precipitatiou 10 not complete. 
Uu Iwiling the sylKStiuiL*e formerly known as matjne$ia aiba 
ia precipitated («t'c p. 124). 

Thhrarfxttuitrjf ur S*tlphnenrbountrn roi^t^mble carbr mates in com- 
poHitiruj, but foutsiiri Htilphur Id plure <jf «ixyjri'n. 

rarhn§4 dhttfphitk ot ifi'^uijt/tiffr (ffirfMnri /Hj^uipfitdttm, U. 8. P,), 
is It Ijighly volatile and iuflaumiabk* lif|iiid, en^Hy iiimie fniin il-n 
elemeiiti^, »Sp. gr. K25<» to L257; lMjilijj|r-point, 4(i° t<i 47** C. 
Whvn jmre it h alinoRt mlorleK^, but a roiuuKTcial Hpefiinen, or 
thi^ [iurc licpiid whii li iuts Ixvu ex|>o*4id to light for t^onn^ firae, 
|HK*JH;*KHes a diwi|^reenble mlor due U> impurity, [oqiure njH^MUii^ns 
may be rt'ddert^d ahuost (wbirb'^ts liy diiit^tiou witb iiaie and then 
with i'opper tnniinpi, or by digesting and diMtillin^ with nu^rt'uric 
diloride. It ottrn loutains di^.sohed >^ulphur. It it*Hliglitly aqIu- 
ble in w«tor Taliont 1 in 4<UI) forming a useful antiseptic fluid, 
Carbijn nHmoHtdphide, analoprms to ejirboo monoxide (carbonic 
oxide), if! 8;tid to have tieeii obtaioed. 



QUESTIONS AND EXERCISES. 

E:yplain tlie action uf hydrocUli>ric acid on liaiumi cliarcoal in the pro- 
cc«a of purilit^ition of the ktttT. — Kaait* the chief imtarul eurho«at<»,— 
What are the funiiula; of carlMtnic acidand carhMai can hyil ridel*— Adduce 
^ividcnic of the exigence of true carlMjaic ii rid— Car l>ouic anhydride is 
constantly exhaled froai the laugs of animals ; why dwii it not ar<;umu- 
1a te ia the atmosphere?— State thei speeifle gnivrty of earhnaic anhydride. 
—By what prmcHs* may carbonic anhydride be ohtaitu-d for experi- 
mental aud aiaiiufactiirin^ puriKiwi^s?— l><'*icrilie the action of carbonic 
anhyclride on iKitajv-siam i.r stiKliun^ carlwinutv — How tnay carbonic anhy* 
dridV h*^* detected in expired air?— To what extent is capboiiic anhydride 
heavier than air?— t^lctilate what «njaatity of t halk m> percent pure) 
will he r«*f|iiin*d to fiirainh the carbonic anhydride nen^ssiarj to convert 
(♦tie f cm nf potassium rarii on ate (containing 83 percent* of K^t'Cji into 
bicarbonate. ^appoHto^nfigjis t*i be waatecL An*., JfiOIJ Uis— Define **hard* 
iie«" in water— flow may the prcaonoe of carlioiiates be detnonatnitedT 



OXALIC ACID» H,C,0,,2H,0. AKB OTHER OXALATES. 

t^nirrea, — Oxalatew oivur in nature in the juice» of ftoriie plants, 
im wood-fl^irrel, rhubarb, the euinmun ibu'k, and certairs lirhens; 
but hydropen t»xalale and other oxalate?* are all made artiticially. 
The ciirbon nt many orpinit- ><ubstiinfes yieldH oxalir arid when 
thoae 8nlwtaTuv« nn* boiled with nitric aei/b nnd alkali-metjd oxa- 
lates when they are rofiatt*d with a uujcture of potiu^iiim and 
Mxbum hvdroxidee. 




OXALATES. 



Masperimcntal proc^u, — On the amtill scale, a mixture of nitric 
acitl 10 part*?, Iniir-siJ^ur 2 iiarts, aod water 3 \mTi»^ quickly yields 
oxiilie tieid. Refl luijirs sire at tirst evoivt^d idmiidHiitly, JindcryB- 
t4ils are deposited on eodling, A more tlilute uitrie aeid, kept 
wana, aetn mure *il<iwly, hut yields uiore oxalic acid. The follow- 
ing proeej^s \^ luore eeoiKiniical, 

Manufaetnnn*j jm/teji^t, — On thtj large scale, sawduf^t \» roai^ted 
with caustic soda, the resulting notliutu oxalate deeonrfM»sed by 
iiu'aii:^ *if »^lake<i lime, with re^eueralinn of eau^slic soda luul forma- 
tion f*f ctdeJum oxalute. The lattt^r is* digested with *(ulphuric 
add, and the liberated oxalic acid i« jmrihed by recrysUdliKiitioii, 

Purifitd ojalic tiehf, — Tlie ae id m nd e t r* an nugn r , rcc rynta 1 1 i xed 
two or three times, is «piite jaire, Ctauuiereial oxalic aeid sluaild 
Im- uiixed with iuHUtheierit water tor coiaplete wihitiou, and the 
mixturt^CKTa^iuually shaken; most td' the iaipuritiea, reaiaia uiidis- 
jw>lved, and the saturated aqueous st>lution on evaporatiuu yield}* 
er^'.HtalH which are nearly pure. AqutniuH Kotutions of oxatie acid 
dlowly decoinpcwe under t!ie inHuenee of light aud oxygen. 

Qti4intim/rnri%^'Viw acid radical of the oxalates is bivalent 
( C.O^^'). The fnnau hi of oxal tc acid m fre(|Uently written (COOH)^, 
2H.U* Both normal oxalates (R'^CjOJ and acid fixalate« 
(R'HCyjJ are known. 

Sttlt o/mrrrf is a crystalline suit intermediate in composition 
between oxalic acid and acid [Mitit^sium oxalate, the crystals con- 
laining two luolecnleaof water of crystallization (KHgCOj, H,CjOj, 
2H,0); 



Anafyiieal ReaefhtiM of Oxnhtes, 

1. To wdutiou ui' nn oxalate iy.g., ummoniuni oxahite) add 
goluHtm of ctilciutii chloride; a white precipitate of «!uleiun» 
oialate, CkC,(\, is* ]>rialu<M;*d. Adtl to the preinpitate exee^ 
of acetic ludd ; it is inwduble. Add hydrochloric acid ; the 
I*ni^cipitat« digmilvesj, 

Thf formation of a white precipitjtte on adding a calcium or 
barium Halt, in.s«duble in acetic but twluble in hydrochloric or 
111 trie acid, is usual ty sufficient pnjof of the presence of an oxa- 
'wU\ It should be noU'd, h<*vv*'vcr. that in the pn^sence of aul- 
hntCM, calctiiin chloride may produre a [precipitate r»f calcium 
'pbate whi(»h is only slightly si»luble in iW'clic, hut is readily 
!*'duble in hydr(M*hlorie, aciiL In the known [iresence of Hulphat€«, 
oi;al;vte may be tested for by the addition uf calcium sul[drate to a 
M>lutjrm acidulated with a«;etic acid ordy. 

2. Heat a fragment of an alkali-metal oxalate (jiotassium 
oxalate^ for example j in a tc^t-tutie ; decointiohitiou occurs 





(accompanied by only a slight tlLirkeuing)* earlwnic oxide, 
CO, y lihenUed, and L'iirl>oiiate of the nietal reiimin:^. Add 
dilute hydrochloric acid to tht;rtaiidLie ; eHlTvcscence occurs. 

Thin h u rciidy k^nt for iiiont ordiniiry oxaljiten, soluble or in«<»lu' 
bU\ and in trii^t worthy if, <m heating the substance^ no charring 
rKTurs, or not dm ire than ^ives ii ^ray c(jlur ti> the residue. Organic 
niftalliL' Wilts ileconi|>(iHi< when heatt'd, tind k'ave a residue of car* 
boujiti% but, exrept in tlie itn^ of uxahitrs, the residue is nearly 
ahvayn accoiapanied by uiuili rarUinK lusoluhle oxiduton aud 
urgauic aalti* uf stich ruetab as lead au<l iiilver are, fd*t'ciur*<e, liable 
to bo reduced tf» oxiilr nr evi'n Ut uietal by the artiua ofheaU 
Such oxaktes tuiiy bedemiupo^t'd hy boiling with sscdtiti on <d' sodium 
earlx»nate, tind the tiilered lirjuiil may be tet*led for i»xahite by 
the eak'ium chloride te^it (or by lueaui* of calcium sulphate, in 
ficetic acid solution). 

Other Anahjiical Rea/'iioru* — Silver nitrate gives, with iixa- 
lates, a white [jrc^'ipitiite of silver oxalate, Ajr^C^O^. — Dry 
oxalatci^ are dei*ouij>ofled when heated with cjonivnt rated 8ul* 
phuric acid, carbonic oxi<le and earlMjuic anhydride e^^aping. 
If euuugh oxalate be eniploye<b the ga.s nuiy be wa?^hed with 
a ciiiisftic alkali, which removes the carlKiuic anhydride, and 
the carbonic oxide tuay tlieu Iw ignited j it will he found to 
burn with a characteri:*tic bluish flaTue. — OxalateK, when 
mixed with water, black man^ane^c oxide (free from carbou- 
atcii), and sulphuric acidi yit^ld carbonic aidiydnde which may 
t»e indeutihed by nu*ans ni' lime-water in the usual nainuer, 
— N«)t only sneh iu»«duble tixalatea m thoKC of lead and 
silver alxive referred to^ but any ordiuary insi^duble uxalalc, 
snrh nH that of culciurn or uiapiei^iyiii, nuiy be defX)ni|wJ3e<l by 
proluug€»d ebullitiou with solution of sodium carbouate ; after 
tih ration the oxalic acid radical will l)e found in the filtrate 
as wluble scjdiuni oxalate. 

Aniiflo/f'.^la cases of poisoning by oxalie acid or salt of surrel, 
chalk and water may be administ+*reil jis antidote (with the view 
of |>roducing insoluble c^kiuai oxalate), emetics and the atomach- 
puuip, or stomach'Siphon, being used as soon as pofldble. 



QUESTIONS AND EXERCISES. 

How iir« oialrtt**s ohtaiued ?— What ia the quatitivalent* of the oxAlk 
nidicjinf— Clivo Uie ri»rmulaof **saU ofsorrtd/'— Menliou thecMef l«»lfor 
omlif acid and otht'f soluble oxalates. — By what ri'iictiuns are Inaoluhk 
oxaiutcii rocogujacd?— Name the antidoto for oxalic acid, and doicribo lu 
action » 




TARTRATES. 



305 



» 



I 



TAETAEIC ACm, H,C,H,0,, AND OTHI^ TARTBATES. 

Sfxinrft. — TiirtrH.U'.s exist in the juicc?^ of triiuiy i'ruhs ; Iml it i« 
I'nnn that of the gnipe that our HUjipIios Jire u?sijally ohtsiiiied. 
Gmp-juice contoinn iiiutb mM iMita-siimi tartrate, KHt'JI^O^, 
wbicli is gradually tleimsit*-!! when the jinee in h nneiited, as in 
making wine; iVtr whilf aeid ii<*ta»siyiii tiirtrato i-s imt \ery ^lia- 
ble in watiT, it is.Htill less so in ?*}iiritu*»ns iiijuid-^, and heneo it crys- 
Uilliz«>i I ait m the sugar id" the grajie-jniee is i^radiially eon verted 
iiiU) alcolifjl. It is found, raixrd vv ith eukiuni tartrate, Hiiiiig the 
ve*e*elH in whieh wine is kept; am! it is from thi.s eruiie substance, 
termed arrjal or nrf/o/, alsi> fnan the iilbnniimdij yeasty matter ur 
*Mee?*" ^ie|J^^^ited at the wmie time, iia wel! as fniui any tartrate 
that may remain in the marc leflaller thejuire has la^en jire>tae<l 
frmn thi^ grHi>es, tliat, by rough recrvHtallizJitinn, *' tartar/' s^till 
eofitiiining 6 or 7 percent, or more of anhydroits euk^ium tartrate, 
CaC^H^O^p ia obtained. From the tartar, turtarie neid and other 
tiirtratea are pre|rared. In obi dried grapes (raisini^) erystalline 
masses of tartar and of grape-sugar are frtHjuently met with. 

Vcrjutcfj that is, rerf/ juieeor green juiee, is an old name for ibe 
very »our juiec of unripe green grapevsami of end) af^des. It eon- 
taioH tartaric, nieemie, and aialic aeids. 

iS'eum of tartar^ jiuritied by crystal listation (Poffimil liifnrtrnA, 
n. 8. P. ), oeenri*asagntty wliite powder, or j^ligbtiy opat^ue rbom- 
bie er>'»tals ; of a pleasant aeid taj't»-% soluble in 200 parts of cold 
and Iti»7 of boiling water, insoluble in aleobid/ 

Quaiifiraiemr, — Tbe arid mdieal of tlie tartrates is bivalent 
(Cyi/Y^, and iHJth normal tart rates (R%(yi^ry ami aeid tar- 
imWn ilVUVJl^i\) are kiimvn. I'ot^issium tartrate (K,CJIj(\)j, 
H/), and Roi^belleiyilt, [Potassium ami sodium tartrate, the otlebil 
PotfiMn rt Siidll Tnrtniit, are illnstrations of nornnil tartrate.w, while 
cream of tartar, KlI(\Ht<\, is an exaoipb* of an aeid tartrate. 
CoDJitilutional formula of tartaric acid: (J!,Ha{t-)H)^(CUUli);,. 



Tartaric Acid. 

Tartaric Afnd (Aridum Tartar ieum^ U. 8, P. ), in obtained by 
[^oiling cream of tartiir with water, adding chalk till etfcrvesence 
oeaueSy and then calcium chloride s4^j long a^^ a precipitate U pro- 

' A bf»ilinj? Bobitionof tartaryieUlsia fit wtini?*" rust of laitiate crystals on 
coalings — jti«<t aM milk yielils a flouting hive r of ereaui ; lieiiec the terra 
e^rtam of tartor ** It iaciiU^d inrUu\*' siys TanuvlhUM, '* Wnnise it produt^-w* 
oiJ. w'tUcr. tiiuturo, nnii sjilt, wliirh burn tliepnlieo* jik hir(j*rii« dms/* 
TartuTtLftA^ \jii{\u (Tn^T4(MK. 'fjirtants, CJrt-eki U*v hriL Tlu' pnidurlH of it<i 
dcfftruettvc diAtillatiuii am ei:rtiiiiiiy BcHiirwlmt irriidtiiifj in Uhi*> witd 
Ntticll ; tittd tbv " ^It " (p4ita8Kiiini i :irtK)uiit«) thmt in bft ia diuretic and ia 
l&rger qumitilifia iHiwerfuIly corrosive. 

20 






306 THE Arm radicals. 

cjueetl ; tbe two jKjrtions f*f i'alciniii turtrnU^ thus ctiii wis.' u lively 
fiiniieil are thoroughly waslied^ treiited with dihitr sulphurir ticid, 
thr uiixtun* boik'tj for a .short tiiue, thi rrsultiug talciufu ?*ul|»hato 
umstly tH'parated liy filtration, the tiltrat*- rout't^ut rated f>y eviipor- 
Htioii, auy further nilfhuti suijdiate that nmy have de [waited 
renioved uh Ixdore, and eviiporaticuj eoutinutsl iiutii the «<dution 
iH^uHieiently runeentrated to erystiillize on eoolin^. The ea hi ma 
tartrate ohtjiined froui nine oiinres ot ereani of tartar rr^iuire^ fivi; 
tjUHft*}^ (by wdglit) of f^wlphiirie aeiti for foniijlete decon (position. 

2KHO,HO, + CaC(), = CaO,H,0,f K.C.H*?)^ i H,tM O), 

Aciil T>f»taiwiaiii Unhilum CaJciiim PntHesium Wnter (Usrbouic 

tnrtrtite ciirlxmntv tiirtrttlc Uirtratu aaliyftrlfle 

K,C\lI,t\ 4^ CaCl, = CaC,H/»„ -^ 2KC1 
FotJLHstum t'ttkiiim tV*h'ium rotiiii«ium 

tttrlrtttb I'lityrifle tartrate cKloride 



CaC\H,0, 

fulc-ium 

lartrale 



f 



Sulphuric 
Held 



= Ca80, 
sulpbiite 



Hc.ir.o. 

TiifOirle 



Tartaric acidoccurn in eoianierce in colorless cryntji!?* or in finely 
crystalline powder. It is readily s*>iu1de in water and in ale* dud. 
One gramme diMsol veil in li Ce. of water forais Tartarie Aeid Tes«t 
Sohition. IL S. F. AtjneouK solntion <d' tartaric aeid iw not «tahJe, 

PareelH! of tartaric acid ol^en contain cryntals of n piiymcally 
ist)nierie modilication Uee JjM^nierisni ). It i» termed pnrfifurhmc 
acid (jTfr^c^ partly beside) or raermh ficid {raretntis^ a hunch of 
^ra[a^), ami is acond)imition uf ordinary tartaric aeid, who*o fvilu- 
tion rotate,H a ray of polarized li^ht in the rijrht (dcxtn»tartaric or 
ri^ht-rotiitin^ tartiirie acid), with Itevotartarie or hd\-rotatinir tar* 
taric aeiil, whose soluticm rotate?*a pidarized ray tr» tlo- IrflJ Kace- 
mil' acid i« inactive in this respect {optical ly inactive), t lie opposite 
properties of its cou.itituenLs nentraliKiiig each other, Kaeemic 
add in \em Boluble in alcohol than tartaric acid. 



Potassium Tartrate. (See p. 78). 



Potassiuin and Sodium Tartrate. 
(Ste p. Ul). 



Koohelle Salt. 



Tartar Emetic, {See p. 188). 

npound Efftnmcing Powder, {Puhis EfftrvrBeem (hmpo&i^^ 
tr* S. P,), i^T SthUih Powdrr, consiMtn of Rochelle salt (120 grains) 
with 40 g:raina of mxliura bicarhonate (the mixture usually wrapped 

* AccordiuK tci Vuu *t lloflufid Lp Ik'll, nil iM>mpouiKl^ that cauie such 
rotation coutikin at Itrast ono ntom of riirbon with which fonr difftrtmi 
alottiB or radieala aro united. Such car bun atoms are lenned tLMSfmmrtnc. 




tartrates: 



in blue paper) ami 34.7 grjiina of tarturic afid (wrapped in white 
pnper). When administered, one jitiwiler in dis,HHtl ved in u tionbler 
nit her more than hall' Jiill of water, the other added, and the mix- 
ture drunk during etrervescent'^. 



Analytical Reactions of Tartrates, 

L To u solution of any neutral hirlnite, or of tartaric acid 
made iicutml I>y ati<iition of sodium hydroxide solution, add 
Bolntion of raid u in ehluride ; a white preeiiiitnte of calcium 
tartrate* Cai'^H^O^, is produce*!. Collect tlie precipitate on a 
filter, ViVLnh, phiccasnuill quantity in a tefit-tube, and add hoJu* 
iiuu of iKjtasaium hydroxide : oil stirrin«r the mixture the pre- 
cipitate rlissolves. Heal the solution : ihe calcium tiirtmte is 
ri*precipitated. 

fn thitt reaction a moderate quantity of the caleiani chloride sidn- 
tion should be added at once, and the test should be performed 
with*tut delay, otherwin** the calcium tartrate will aKsunie a crystal- 
line character and lie with difficulty di8tHdved by the caustic pot- 
ash. The latter should tn* quite free frmn carbonate* 

The wduhility of calcium Uirtrate in cold caustic potiish aolution 
enuldew the analyst to di?ftingiiiHh l)ctween Uirtnttt^ and citrates, 
otherwise a difficult noitter. Calcium citrate is not ^soluble, or (irdy 
to a slight extent, in the alkali. The absence of much aaimuninm 
(»alt must l>e ennurLHl, calcium citrate, a« well an tartrate, being 
isolublc in solutions of ammom'um siilLM, 

2. Acidulate a solution of a tartrate with acetic acid» add 
potus^ium acetate, and well stir the mixture ; a crystalline 
precipitate of potassium bitartrate slowly se^mrates. 

This reaction is not applicable in teKtinji? fnr verj' small quantitiea 
of tartrates, the acid jKJUissinm t^iilrate l>ein^ not altogether insolu- 
ble. Tlje precipitate being^ insoluble in idcfjlud, liowcver, the 
addition of the latter renders the te.Ht much more delicate. 

3. To a neutral solution of a tartrate add solution of silver 
nitrate; a white precipitate of silver tartrate, A^%CJI/\p h 
finxlucexl. Boil the mixture; the |>recipitate blackena owinj^ 
to the reduction of the silver tartrate to metallic silver. Or, 
tiefore boiling, add a drop, or leas*, of ammonia water; a mirror 
will form on the tube— adhennt^ well to the glass if the tulte 
was tboroujjfhly cleansed. When even an insoluble tartrate 
h placed in a dry tube with a few fragments of silver nitrate, 
and a drcip, or les^ of ammonia water is added, a mirror-like 



308 



THE ACID RADICALS. 



character ib imparted to each fragment of silver salt wheD the 
tulte h ^en\\y rotateil sonit^ iiirlu's ul>i*V£* a Biinsen flame. 

(Hhf r iieadums, — Tartnite^ heated with eon eeot rated *^ul- 
Iihuneaciil tluir iiimieiliately, or at lea.sl very raj»idly. — Tar- 
tarie nvvi ami the Hiluhle larlrati'^ ]>reveiu the preeipitation 
of ferric unci uther !iydroxi<lc8 nji theaddilifui of alkalies* solu- 
tinrLH iif douhlc tartrates ht-iu^ tormevl ( which on cva|Hjratinii 
yiehl li(|indsthat tlooot cryi*talliw.% hyt^ when sprctid ooshecU*^ 
of glaiss, dry up to thin tmiwjiarciit jilatCB or Ruile^). Iron 
and Amnioniiinr Tartrate ( F*rn tt Amnwnu Tart inn, l\ B, P.j 
ami Iron and PotaKsiom Tiidrate { Ferri et Potami Tarlm*, 
U. K P.) ^^^' preparatiotiK of thia kind. — Metallic tartrates 
decorn]>ose when heated, earJton JK-in^r ,«iet free and metallic 
carhonale (or metal in the case of ea.'^iiy rcducihlc metals J 
formed, while tlie gaseons* prodncts |K)St!e88 a |M:'cnliar, more or 
hi-s eharacteriatic smell, resemhling that of hiinit sugar. 



QUESTIONS AND EXERCISES. 

Stalf tln5 (irigin of tarfArif acid and other tartrutps, and explain 
deprjrsitiou i>f argol, crude nvM potasalum tarlrnk*, diiring the ttmnufflc- 
turc of wine.— Gi VI* the cliciniail fonimltt.nini t be cba meters lif "jmrtfltMi 
cn^iim of tatrtar/' — Mention the fornitjla andtiiiantivalenceoftlieUArtaHc 
nidical.— Writt^ the formiilji^ of u number of tartrate*. — Give eqUAtion^ 
il1nHtratiiii|( tht- jirodnction of larUirie a* id from, ptirilied cream of tartar. 

— Hy wlnit geuerMl |>r*jccss may iiornnil or donble tartrates W ohtaintM 
frtmi acid potassium tartrate '/ — f rive iMjiiation-* represtutingthe reactions. 

— Enumenite) the teste for tartrates, and describe the ei!ect« of heat on 
aActallic tiirtrates* 



CITRIC ACID. H^C^H^O,, H^O, AND OTHER CITEATES, 

SofitTf'i*, — Citric acid (Aridum (Htricum^ U, H, P.) exisLn in the 
juice of the g(K>ft<*berryt currant, cherry, Ktruwberry, rai^pherry, arul 
oiiiny other fruits, as well a.H in other part* of plants. The pulp of 
the frijit of Tnmnnndujt {tuiini {Ihrnarinffuft, IL B. P.) contains 
from 1 t<( 12 percent, (in iidilition to l.o of tartaric acid, 0.5 of 
malic acid, ami .'I jKrcciiL of acid [oiUusniuai tartnitc). But it i» 
fr<»m thelcuion or linir that the citric aeid of comnierce jj* uj^ually 
ohtained. For this (mrpo!*e c<oiceutratcil lefnoti-jnrce i« exported 
from J^ieily, coiucutrated herpmitii-juiec from the t *alahri»n coftUt 
o f Sou t h I tjd y , H a < I co rice a t ra t e<l H ni t^ -j n iec f ro ai t li e W est I n 1 1 iee. 

Citric ncid may he jircpari-d fnan IcTiion -juice hy the following 
pnx*e»*: — The hot juice should be mutraliztHl hy the addition of 
powdenwi clialk, the resulting calcium citrate collected on a filter^ 




CITRATES. 



30t) 



washed with hot water till the liquor passes from it colorless (by 
which not only the colf^ring-nuittor but the niucihige, su^iir and 
other c-ons^ti tut' nlj^ of the juice itngdt rid i»t ), then niixod witbeuld 
water, deciiiu|)osod by nieiLjm ol' Bulphurii- arid, the mixture hoik»d 
for half an hour, tllU'red, the Kohitiuu evaporated to a deiijiity of 
1,21, set a^ide for 24 hours, then jMtureii nff (nnix any deinwit id' 
crystalline calcium fciul|>hat4% furtht*r eMiueot rated and net aside to 
ervHtallize. It' the quantity *d eideiuin citrate deeoniposeil va 
unknown, the sulphuric ucid Oiay be added until a little ot' the 
HUj>erniitant Huid givc.s, idler a nutiiitc or two, a preeijiiiate with 
rtohitiuii of ealeium ehloride. Tlie coueentratrd snJution of citric 
tteid genendly crystallizes very slowly. fShaken viohritly, however, 
in a bottle with a granule or two of wdid acid from a previiaijicrjii* 
lidti/^ition, it quickly yields its citric acid in a pulverulent form, 
and this drained and rediK>M>lved in a very fiundJ (quantity of hot 
water yields cryatalt moderately quickly (Warington}. 

2H,C,H O, + 3CaC(>, = Ca3(C,H O,), -f 3H,0 + SCO, 
Citric AC fd Calcium Calcium citrate Wtttcr Cnrboulc 

carbonntcs nuhjdride 



^ 



C«,(C,HO,), 
OUcian ennktv 



+ 3HS0, 
Sulphuric acid 



2H,C.}I,0, 
Citric acid 



Calcium t^utp^^ale 



^ 



Citric acid is now manufacturcil by the citric fennciitation <»f 
irlu<itse, which take^ place in prt^sence of the fungi Vifromtjreg 
fyrffrriftnfi^ and (\ (jlahfr. 

Jltr arfifidftf production of citrie neid has t>een accomplishtnl by 
Griniaux and Atiani, wlio, Htartinp with glycerin, produce certJiin 
chloni- and eyano-derivativcA! luid ultimately ciirie acid iti*idf ; it 
ha?* aJj^ been built up by starting witli acetone. 

*Mric arid it^lf Lh tlu' only citric componnd of much direct 
imporUmce to the [diarmarist. It usually oreur>^in colorli><M crys- 
tals siduble in .4 of their vvei|rht of boiling atid in .M of their wf^i-^dit 
of cold waU-r, lej« soluble in alcohol and insolulde in ether. ^ A 
•olutifjn ui 30 to 40 grains in 1 uiince of water forms a wibstitut« 
for lemon-j uice. Sifrupu* A ndi OVrici" is . iffieial Citrates heated 
with concentrated sulj.hurie acid to nbc^ut *215« F. (H)IJJ^ i\) 
evolve carlKmic oxidt?^ and at hight^r tempemtures acetone and car- 
bonic anhydride. 

Aciion of hmt m citric aetd. — Citric acid when rIowIv heate^d 
Krsrt loee*i it« wat4^'r of crystalliziition ; afterward (347** F./l 75*^0.) 
the elements of anrttber molecule fd wat^r are evolved and a rcsi* 
dacnht4dni*d from wliich either extracts acfonh acid, H^VJJp^^ 
identical with the acfinitic acid (and the acid first tennwl e</mjfftic) 
Ul variuUH Kpeci«*i* of Amnium and Etptinettim, 

Qitftnfivrdrnrr , — The neid ra<Hcal of the citrjite** is trivaleni 
(CJIjt»,'^0* Three chwHi^ of citrates are known, in which one, 
iwo^ or all three at^miH rcH|>ectively of thi} replaceable hyilrogens 




310 




THE ACID RADICALS. 



atoma of tht* iititl^ H/^^H^t >,, are n-jilaced by equivalent propor- 
tiimw of metallic nidiadft. CouBtitutkiiud formula of tit ric acid, 
C,H,(OHj(CUi)H),. 

The official Lenum-juict- (Lhnonij* Swcu^^ IT. S. F.)i.st<ilH^ freshly 
expressed from the ripe fruit, to have a j^peeilie gravity of iJltiOto 
iJHi}, and to euiitain frotu 7 to ^l ptreent. td'titrir lit id. t Il/.'^H^O^, 
HjO). The aeidity rnay l>e !i.Mcertaiiie<l hy addirif; potjissimii hrdrnx- 
nh% V. a, till rfd litiBii>v-]mper in liiriied dwtiiietly hlue. Before 
jijiplying thi>* test t«j eooiiiiereial speeimerif^ of leiiion-juiee, the 
absenee of tiotjible tjuuritities of sul[>hurie, hydnjehloriCj aeetic, 
tiirtaric, or other acid mitst lie i nsure<l by apidieation of approi^ri- 
atc reagenti*. (*Vtr also *VLeiiion-jiiiee '* in Index). 

Lime-juice eontaina an average of 7.84 pereent. of citric aeid^ 
rarely rising to 10 percent, luul very Si'Moni falling to 7 |iercenL 
Containing but little Kugar ajid rnncilage, it rcijnires no addition 
«if alcohol to pref*i'r^'e it* Lertton-Jfjire requires about 40 [lerceut, 
of proof spirit to prevent fennentution (Conroy), 

Anahffical ReaetiouH of CHmtes, 

1. To a dilute if^olntion of any neutral dtmtei, or of citric 
arid catrpfully neutralized by midition of |wtassium bydroxide, 
add Molntioii of calcinrn ebluride utid boil j a white precipitate 
of eaidufu citrate, Ca^(CJI^i),)j, is priwlueed. Trt»at the 
[jrecipitate na destiribed in the eiise of ctdcium tartrate (|>. 1^07 > ; 
it is not |ierceptibly dissolved in the eatistic pitas h. 

An approximate separation of citrate and tartrate can l>e ef?ected 
hy a leans of this reaction. Ruth radiials nn} ])rcci pita ted f^ cal- 
ciinn t<nlts, and the rajiidly washed jirecipitate in mixed with i>otai»- 
sinm liydro.xide solution, diluteil, and filtered ; the filtrate eontain« 
the tartrate, which ik shown to lie prcKcnt by the re[)recipitation 
oil boiling. The [>rmpitate 8till on the tiltcr in washed, di8s*olved 
in >M»lution of ammonium chloride, and tlie ii<dution Imiled; the 
caleiuni citrate in reprtn-ipitated. The prt^senee of much sugar 
interferes with this reaction. A dilute wdntion of a citrate ia not 
precipitated hy eidL'iuni chloride until the liquid is heated: precip- 
itation from a eoncentrated M)lntioii, also, \n not complete with- 
out ebidlitifm of the mixture. Thii^ reaction in not thoroughly 
ftatiisfaetorVj calcinm citrate being dightly soluble in alkalies, in 
the solutions of ^Ita pr(Mhi€0<l in the reaction, and, to a very 
slight extent, even in cold water. It in readily soluble in acetic 
acid. 

2. To a neutral goltition of a citrate add sohition of fiilvcr 
nitrate; a white (ireeipitates of silver citrate, Kgf'JlAX, is 
prfxluced. Bfiil the mixture; the pre<'ipitjite does not blncketi 
rapidly aa stiver tartrate flw&, but only after long boiling. 






CITRATES, 



311 



^ 



Other Analiflleal lieax^tions. — Citric acid forms no precipi- 
tate eorres|>ouditig to p^tai^sium bitartratc. — liriie-w liter, in 
excese, gives no j)rei*ipit:ite with a dilute flolutiuri of ntric acid 
or of tt citrutc unless the Boludon is boiled, calcium citrate 
l>eiug slightly s<»luhle in cohl hut uot in hot water; liiiie-water 
Uf^ually givca* precijiitutcs with tartrates in the cold. — C'itratci? 
ilo n4»l char imniediutcly when heated with cooccutnited .sul- 
phuric aeid. — ^('iiriL' livid and eitrate*^ firevent the precipitation 
f»f iron by alkalici^, s^uliible doidde <"om|Kmnd.s l)eing formed. 
The officifd Iron and Annni>nium Citrate (Fern d Ammoiui 
Ciiras, U. H. P/J is a prepanition of thi^ kind, — Metallic 
Citrates decompose when heated, earl>onates4 lieing iormed and 
carbon set fre€; the oih>r of the gaseous proiliicis is not eo 
characteristic as in the case of tartrates. — According to Cail* 
letet a cold satunitcd ,«4>hition of p>tassiu!ii dichromate turoa 
a solution of tartaric add dark-brown, carbonic anhydride 
being evoh'ed, while a solution of citric acid only slowly 
becHjmes light-brown, 

Pn^ch'j*feMf]t/f>r fhe ditectioft of tartaric arid in nfrit' aeifi depends 
on the well-known ditlerenee in the action of sulphuric arid on 
tartaric acid juhI on citric sicid. It consintH in arldiag lo 1 
gramrae of powdered vHriv aeid in ii drj' test-tuhr 10 gramuicH of 
pure eouct^ntratt'd (culorleMH) Kalphiirie acid, and keeping the part 
of the tube eontainiag the aiixture itmnerwed in iKiiling watiT tor 
an hour. The citric acit! dist^oht'?* with evohithin of gas and 
frothing to ffjrm a lemon-colonel lirjuid^ nnd ii'thcsjimple be pure 
tliia color undergoes no chiinge withia haif an hour ; but if an 
much as one- half percent. *>f tartaric acid Ik* present, the h'nion 
color becomefl bniw^nish within tliat tiujc, and in an hnur the 
ndxture h red*browa. 

The f)re*«enee of tartaric acid may alsf* be detected by the 
folkiwing methrid:— Add 1 gramme of citric acid to 1 t'c. cif a 10 
jwrcent, solution ofiuniinmium molyhdate, and then a few <iropi* 
«if a very dilute solution of hydrogen peroxide ; if tartaric acid i» 
preaent, a fine blue color apfjears: in ita absence the color is 
jrdluw. (Crisuier, ) 




QUESTIONS AND EXERCISES. 

What is the noam* of citric acid ?— Des^'ribn the ijrcpnration of citrie 

»cl«l, {rivfiift •Mumrioiis, — It1iiitti-at4; by fumiutee the various flnaws of 

tAf Crutch ami ritmtw*. — State the avenige jiFoportion of citric acid io 

Igtimti j i I i I'i? . — W h i\i nny tlie Uwtft for citmteaY — How are tartriittja liepiir 

] tt0m cttmteN ? 



312 TJIK ACID HADWALS. 

FHOSPHOEIC ACm, H^PO,» AND OTHEB PHOSPHATES. 

iSbi/rrr. ~ Tlie suurcc «>r the ordimiry plu^sjjlijites ami <if jdios- 
phoTtiA }ii^}U{Pho^tphr)ntJi V. 8. P.) is tlie iioniisil cjilrium jihrm- 
phiite, C'a^iPtJ^),. Tliiii is the Lhief Loiislitueiit of the hones imd 
tet*th of Jiiiimals," heing ilerivetl from the filauts tm whieh they 
feed, |>huiLs jigjiin oblaiiiini^ it from the smiiI. Oiiiipouiids of 
phosphoriLs tire als<* n*tt with in tbehrain, iierveH, imji*tdes, blcwid, 
saliva, and, acrortlin^ tti Kirkes, ewn in tissues ho siaiple that 
one muBt n.ssume that the coaipoujids sire ntTe;<:^*ry c<.iiii<tituents 
of the suhi^tante of the prinian- eelL Phosphates are eliminated 
from the system both in the urine and in the fieeeM. 

Ph<i^**I>horns in idiUtined from hones l^v the tiilkiwing proeeR^es : 
— The hones are ealcined to renn>ve nil traees of animal matter* 
The recalling hone-earth Ls treated witli hot and uioclerately con- 
centrated Kiilphurie aeid, wherehy phosphoric aeid and calcium 
aulpliate are produced :— 

Ci4(P0,), -f SIIjSO, ^ 2H,P(), + 3CaB(>, 

The acid fluid strained from the ealciuni sulphate and concen- 
trated, is mixeil with ehareoitl, eiike, or sawdust and ilried in an 
iron pot. At this stage wat4?r eH<'ai»eft, and metapliosphorie aeid 
remains: — H3pO^ = HlM)^ f Hj<K The mixture it!) then tnin>i- 
ferred Uy a fireclay retort and strongly hetded ; phosphorus vapnr 
is evolved and ia condensed under water wliile hydrogen and 
carbonic oxide escape, 

4HP0. 4- 12C ^ P^ -f 2H, + 12C0 

Tlie phosphorus is purified by melting under water containing 
sulphuric aeid and potassium clirhromate, and is tiltered through 
canva» and cast int^> w ticks. 

Praperiieji. — PbosplioruH is a translucent, wax-like 8oUd (in 
sticks or cakes), which emits white fumes, which are luminous in 
the dark, when exjKised to the air* Sp. gr. 1.K2. It is nift and 
flexible at common lem[>eratures, melts at \ 1 1.2° F. (44** C) ignites 
in the air at a tem|»erature a little alwne its melling-jMiint, bums 
with a luminous flaaie and ]>roduees dense white ftimes* It is 
insoluble in water, but fudiilde in ether, in Iwdling oil of turpen- 
tine, in carbon bisulphide, alisohite alenliMl, and chloroform. U 
is soluble in oil whirb has been previously heated for a short 
time to about 30*r F. (148.8^ C), to expel moiaturc. Pills eon* 
taining it are oflieiah (Pihihr FhmphM-i^ V. 8, P.) 

GramilfUed or pulverulent fdK»sphorus is ohtainet! by placing a 
quantity of pho«|>horus under equal parts of alcohol and water in 
a bottle, standing the Ix^ttle in warm water until the phosphorus 
melt», then injserting the j«to[)per (glass, not cork), ajid shaking 
the whole till eohl. 



PHOSPHATES. 



313 



Red or *^ Amorphous'* Phosphor ui^, — Orclinary phoKphonis wlii-u 
kept at a teiupt^rature of abnul 4*10'* F. (2li2.2" i.\) iii an atmas- 
phere from which air is exdu<k'<l, beconie.s ri'ilj upaqm^ and in- 
soltilile in li<(i»i<lH in which tinlinarv pliusjibonis is «o|yl>U\ The 
rt^d iiioditifation \\\ jihii-sphorus obtiunect in Ihi.i way undergoes 
oxidatiim extrenit-ly slowly, and oidy i^niten when hi'ated to nt-ar 
500° F, {2^i^° C\ Thouijh long ro«j;ardtMl ms ann»rphouH and 
still IcHuwii im Hifiitrphous* phoi>^phoniJi^ its stnicturc is really crys- 
talline. It is nsed in the nianufactiire af several varieties r>f 
niatrhi'H, and it Uiis the advantiige of not emitting the poisonous 
fnrues given olfhy ordinary jdioj^plioruH,. 

Quanfivfil€nct\ — l^ho^phorns is a i|nin(|iii\"alent element, wa seen 
in the pen tJiehlo ride, IH'I, and oxyehloride^ iMK'l^ ; but it often 
exhibits trivalent aetivitv, as seen in the triehloride, PCI,, and 
trihydri.le, PH,. 

Mokctda /or/?*F/A/.— The vapur density of pha«phnms eorre- 
spmils t(j tiie in*dei'ular fornnjla, 1^ Phosphoras in the state of 
vapor thus ditibrs from nxy^ren, hydrogen, ehhirine, etc., by 
having four atoms in its molecule, whilst tht?se elements have 
oidy two, 

Fhospboric Add. 

The ehief use of phom[d]orus in pluirmafy is for the pivv 
iluctiori of Diluted Phtmphoric Add. rhtjsphoru^ is boiled 
with nitric aeid and water until it ilisiip|H^ars. The ^tdutioii, 
evajMjrated lo a small volume to renwve nitrous e4nn|wuind8 
and until the product has a sp. g^n fd' 1.7U7, eiuitiiins 85 |>tT* 
cent* of plios[dajric acid, H^PO^, and is the Amdum Phos- 
phoric urn l\ S. P, The latter, diluted so tis lo eiuituin it) 
jMTeeut. of phosjihorie ueid const ilutcs the Aeififtm Phtuphm- 
fum LHlufunh U. iS. P,» a eolorles** sour liquid of sp, gr. 1*057, 
If the ueeei*^ry appliances are at hanti, spei^imens way he 
prepflreil by boiling together KK) grains rd' jihosphorus, IJ 
fluidouiK'eti of the otfidal nitric nchl and 2 <iunce.s of water 
in a rtask attached lo n vertieal naidenser (or f^iune such 
arrangement wherehy the txmdensed proiiuctvS are returiieti to 
the rtaskj until ihe phospliorus lias disappeared. 



3P, + 20HNO, + HH^O 

Pticwfilionii Nfirlc acta Wol«r 



-. 12H,P0. + 20NO 

Fhi»»phbric &cld Nitric oxide 



The liquid reumining in the flask is then transferred to a 
*Ush ('preferably fif platinum ), t^voponited down to ulMiut half 
ounce, and then diluted w^ith the uecessary quantity of 
stilled water. 



314 THE ACID RADICALS. 

The use of the water in the i-ariier part of the proceas ia to 
modemt*? the reactitm. Hot coiiceiitnittnl nitric ni'id oxidizes 
|>hcw|jhi>ru,'! with aluuLst expiosive rapidity, heiiee the acid must be 
diluted in the lir^t instaiire, mid the diliitioii iiiUKt be maintaiDed 
to prevent the at id from Ijeeooung Urn eraireiitrated by lot^s of 
watfr» Time is naved by usiii^ courentrntiMJ aeici, t»ut in that 
ca.^' eoiiHtanl suprrviyion is ne<;e&owiry in order that water may be 
added, or the teujperature otherwise redured, should ihe action 
beenaie tiKJ violent. DeJicientjy of idtrie aeid must alwo be 
avoided, or some phoj^phorous aeid, Hyru^j, will be loraied. 

Markoe^ also to eeoaoaiize time, aiodiiied the j^roeesia by addl- 
ing (m every ounce of [>hoHphorus 4 or Tj i^rains of iodine and, 
drop by droji, 25 or i?0 drop** of broauiie. The iodine and 
bromine unite with the phi Jsp boras rt-adily, or even with violence 
that would be exjdosive if not eontroHed by the presi^m-e ol the 
ccdd fluids (further eooled, if necesaaryj by immer.'sing the ves5*el 
in cold water). In the courne of the reaetion it may be assumed 
that phosphorua iodicle and brtmiide are first foraiiHl. These in 
the prei^enee of water immediately yield hydriodie and hydro- 
bromic aeidi* (HI, II Br) and phosphoric acid. The aitrie aeid 
attacks the hydriodie and hydrrdiromie acids, j'i elding the lower 
oxides of nitrogfii (which esi'ape as gan), water, and free iodine 
aud bromine. The latter unite with more phos|>horus, and the 
reactions are n-peateib This earryin|j: power of a 8nmH ipiantity 
fd' iodine or bromine or both would perhapH be indefimtely pro- 
longe<l if no vapor «d' the^se ehMiieat.^ or of hydriodie and hjilro- 
bromic acids es+'apeti with the ^ases. The phosph<^*rns having 
dbiapf>eared, exec-ss of nitric acid is mostly got ri^l of by dropping 
in clean raj^ or paper (nitric oxide, rarl ionic an hydride, and 
water iRdng forme<i) and, the last portions, by adding oxalic acid 
(which eveji more readily yields similar products). Evajjoration 
to a syriq^y consistence finally removes all traces of iodine^ bro- 
mine, oxalic aeid, and moistuie. The product in then diluted to 
any required extent. 

Krprri mental proce^tsi. — A flask, into the neck of which a funnel 
18 inserted^ while a tn^eond fiinnel is inverted so that it* mouth 
reatii within the mouth of the first, is an efficient and convenient 
arrangement of heating and etmdensing ajjpamtus for thig pro- 
cess, specially if the operation l>e comiucted slowly. {See Fig. 39.) 

Solution of phosphoric acid evaporated to a sp. gr., at 25,5** C, 
of 1.850 yield.^ a mass of iirisuiatic crysUils, li^PO^, especiidly if 
a crygtal or two of the acid from a previous prepii ration be dropped 
into the fluid (Cooper), Further evaporated, it leaves a residue 
which melts at a low red heiil, ykMm^ pijrtt/fho»jfhonr aciii, H^P,0,, 
and fmallv, inetaphonphoric (wuf, 11 Pr*^ (iilficiai Pfimpfwrie Acidj, 
(Compare p. 833.) 

A commercial variety of jdiosplHirit* jicJd, c<tntiiiDiDg Do larjre 



PHOSPHATES, 



315 



Fuh 39. 



amount of inipurity, is prepared by ihniiijfhly tJigesting amixttire 
of bone-unh, }*iilphunc add, tmd waU'r; tiitering, coufeiitmtiiig, 
preeipitating citlriuni by ineuiis of i-oiiL-eiitntW*! sulphuric arid; 
and hwiting until sulphuric acid vajRirs nn 
longer e.Ht*ape. It is alscj prepan^d by burn- 
ing pho«pboru:< SI* HH to olilain plm^plioric 
anhydride, diH^idriiig the latter in wat<*r^ 
and boiling with a little nitric iit id to ox- 
idize any lower acidw of phtj^fplioruH and to 
caui*e any lueta- or pyro-j^boriphoriL' arid to 
take up the element^ of water suid form 
ordinary ororthophoaphoric acid. 

Prejiared from bones, phoj^phoric aeid is 
apt Ut develop fungoid de|H>sitJ3 ( JenHi'u). 
Prepare*! from phospboruM, it occaNJ.mally 
containit arsenic in the fonn of arHeiiicacid. 
The latter is detected and removed, tn* 
gether with any tracer of plaliruini or lead, 
by paaaing hydrugen sulphide fur ^ime 
time through the warmed acid. 

Quanthaftnce. — The acid radical of the ordinary phosphates, or 
orthophoMph*des, is trivalent (PO/^''). By the replacement of all 
or of a part of the replaceabie hytlrogeii of ortho|diOHf^hc>ric acid, 
HjPO^, triroetallic phonphatei* (M'^Pt)^), diraetallie aciil phos- 
phates (WjHVO^), or monometallic acid phosphates (M'M, PC J, 
can be obtained. The phospbiitcH met with in nature or used in 
phannaoy are all orth«>[»hf>sphat#'s. 

Crude dry calcium phosphate ground with sulphuric acid yielda 
the very largeiy uncd artificial nnoiure termed "stiperphwfihate." 
It ciintains acid calcium phostphate, CaHj(PO^),, 2H,/>, and eal- 
c on n su I phat^, CjlSO^ , 2 H ^t K 

The rsirer pyr<i|ib<is[ibfctes and nietajdiosphates, as well as the 
phosphites and hypophosiddtes, will he mentioned subsequently. 




Analytical Readions of Orthophonphates, 

1. To an arjueoua Bulution of a pbospbatie (>.f;., Nn.,HPO^) 
add 8<jlutioQ of magnesinni sulphate or chloride with which 
ammonium chloride and ammonia ha%"e been mixed (**mag- 
nesia mixture"); a whit*^ crystalline precipitate of ammonium 
magnesium phosphate, NH^iMgPO^, m pnulmeil 



Ammonium chloride is added to prt»vent the precipitation of 

magnesium hydroxide, Arsmat^?^, wliicli have close analogy with 

phoHphatea, give, with magnesia mixture, a precipitate of ana- 
logotia com])oeiition. 



316 THE AVin RADICALS. 

2, To an at[ueous solution of ii jihogpliute add solution of 
silver uitnite ; light yellow silver phtmpliftte, Ag^PO^» ifn pre- 
cipitated^ — iMini])letel}% if the niixriire he neither iieid ooralkii- 
line. To a portion of tlie jirmpiliile mid ammouia water; it 
diesolves. To uriother jM>rtiou add nitrie acid ; it diiv*;olves. 
By the first part ^d" i\m reiKtiuu [ih(A'ij>hate^ niay be dis- 
tin^^uiiiihed from their elose allies, the ariienales, silver arsen- 
ate l>eijig browo. 

3* To a ^olytiou(iii a few drops of acidj of a phosphate 
insoluble in water (ejj., Vw^iVi)^)^) add an alkali-metal 
acetate (easily made by addiug excess 4if acetic add to sodiutn 
hydroxide or to ammonia water iu a test-tube K and then a 
drop or two of sijliuion of ferric chloride; a yellowish white 
precipitate of ferric jdjosphate, FelK)^, is produced, insoluble 
in acetic aeid. Too much terric chloride miit^t ti<it be added, 
or ferric acetate will be [>roduced, in which the ferric phos- 
phate is to Bomc extent stduhle. 

To remove the ivhole of the phosphoric radical from the solu- 
tion add ferric chloride so long as a j»reci(*itate is prtKluced, 
and Imil ; ferric phosphate and oxy acetate are precipitated. 

To obtain conjtrmatonj evidence of the prcsen*>c of piiusphate 
in this precipitate (and to separate the ]>hosphoric radical as 
a phosphate of more characteri.'itic ap|>earance )» collect the 
jirccipiiate on a flitter, wa.^h, dnip Bome ammonia water on it, 
then ammuiiinm bydrosul|drule, and filially wash with water; 
black ferrous sulphide remains on the filter, while ammonium 
phnsphate is present in the filtrate. T(» the filtrate add mag- 
nesia mixture and stir well ; a granular precipitate of ammo- 
nitira magnesium phosphate ap|iears. 

4. Dissolve a little calcium phosphate f or any other pho?*- 
phate } in dilute nitric acid, add dilution uf anmionium molyl>- 
date, * and heat gently; yellow precipitate is prtMluced, This 
precipitate contains what is somewhat indefinitely termed phos- 
pho-molybdic acid — a compcmnd of molyhdic acid and phois- 
phorie acid ( atiout 4 percent, of H^PO^) with ammonia (nearly 
7 percent). 

* Mulybdenum tna« h respmbles lead, hence the name of the metal, from 
M<)Av0Jo«, molubilot, lend* Aiimioniura rjiolyy«liit*\ fNIlibMoth, i^ohtnined 
by ruttfitiiifT the native iiiolyJWl**niiiii sulphide, MovSj, so as to ronvert it 
into molytWlic oxiiltt or Anhydrjdi% MaCJj, mixing tlie latter with wjit«»r» 
ttddinj; Ammonia, evaporating nnd (irystalliziriiL:. Molv^'t ' Mie 

formolie MjMoO* : MRMnni; MITMt>Oi, TfiM^.cniM- rn 

tifjiny metal) have l>een otauiued, Commennal iimm< , ite 

i& commonly the mtermcdiiit« mU. 




^ 



According ti> von Juptm r tiirtarie jicid, even in large excess, 
does not prevent tht? coni|)lete preeipittLtiMf* of phoHphorje acid by 
molybdiite iwjlution, Tht; addition f*f tartarif jii id to the molyb- 
date sMjluticoi or in the pbo-^pbate i^ therefore t<j be reeuuimende<i, 
to prev*»nt tlie eontaaiiiiation of tlu^ yel!ovv preeipitate with ferric 
conipjundn. 

Nfffe.- — The forego int^ two rear t ions? are useful in the suialy^i!^ *»f 
iMine-earth, of other earthy ph us ph litest, iron f>hos[diate, and all 
pbijxphjttes iii>M>lublu iti water. Only arwenate,s give similar appear* 
anee?^ ; but the aeid Kulutinn of ilieni' inay he deeoaipuHHl Ity iigitn- 
tion with sulphurous aciil, ehumtioii, and »ubse(juenl treitUnent 
with hydrogen sulphide — yellow ar^enoun sulphide, As^S^, being 
then preeipitak^d* 

Other Anaitfticai EfaeiiojiM of Phoaphafes.^^luthn^ of 
bnriuni aud calciuin paltM give, witb acjiieous solution? of phos- 
j)hatei?, white precipitates of the re^|)t!i live pbosphatej*, BallPO^, 
or JK(Pt>/)^, aud C'aHFO;, <"- <^X(l'Oj,, all of which are 
eoluble in acetic aud the stronger acids. 



QUESTIONS AND EXERCISES. 

Stftte the direct and indirect sourous of phospliortia.— Give equAtions 
erplaniiiory of the isolatiim *if phospbonis frirm itsciimjioutHK — Eoumer- 
atc the profiif rtieniif phtispliorus, — Mtiitjoii s/>mi? solvents of pho.Hpboru8, 
— How are the twi* chief varit'tiL>i f^F ]tli«>*iphnric iieUl nuide? Lkscribo 
the precaiilioiis to he i>b.st'rvi'd hi making Ihis aeid.— What Jirt* the 
iitreD^'ths ftf the offici.l1 acids?— \Vril« fonaa las illust rati ve of all iliiHsi'Si 
of orthophosphaU'Ji.— What ih thu roaipitfiition t>f farfia^rs' ''suporphoH- 
pbale/^ and liovv is it preparid '/—Mention the rhJcf Wi^i for sohiblc aud 
iTiA<oIuhI« phoHphtiteH. — By wbut rc^icttoiijiuiay )ihoi^pliatct§ be ditstitigiiiHbed 
from erseutttea? 



Vanai>ium V, 50. 8> is a very rare olenient, and i* here men- 
limierl only be<*an)*e of its exeeodincjly interesting^ rehiti<m- 
**fiip k) nitrogen, pho!«phonis, nrs*enie, and nntiniony; ulon^ 
witb which it f«>rnis a jiene,H of five elosely alliecl elenienti*, 
Di^overed, but not im>latcd» by J^efMrutn, and it^^ eompniuds 
ilive«ti^nted by lierzeliu?^, it \va.s ubtaiiied in the free 8latt' and 
fully «tudie<l Ivy Ilof*rHH'. 

The gnhjoined fMrtntibe ilhii^fralo I he re.*endilanee in rmn- 
|Hif«ition Ivetween i*«one of tlie eornpouutid of vanadiym and 
thoflt* af nitnigen and phosphorus :— 




[ 




318 THE ACID RADICALS. 

iN.cv Np,. :n,l\ no, N,0. V/V V,0,, \\i\ VO, V,0. 

Orthopbiiriphates . R'^PO^ Urthovamidates . H',VO^ 

Pyrt>pli<>sj>fiiiU-s .. K'J\0^ Pymvaiiiidiite.s . R'^V O^ 

>ietaphu^pliatea . R'FO^ MetavaDadates . R'V^O, 

homorphoits Minerah. 

Apatite , . • , 3C\{P0;),, CaF^ 

Pvni!iii)rphite . . , 3Ph/PO,),. PbCl, 

Mimetej>«itt^ . . . 3Phj^( AsO, ),. PbCl, 

Vauadmite . - . 3Pb,(V0,},, PbCl, 



BORIC ACID, H,BO^, AITO OTHER BORATES, 

The rkmeui fMtoti^ like cnrhon, iHTUrs tii tlie iiDuirphoiiH, gmphi- 
tt)id;d, and cmtidliiie condition}*. It la a trivftltml element yield- 
ing lialtjgen tMini[M>tind^, suib jih the cbJoride, BCI^^ and ttuoride, 
HFj|. Ita atmnic weight it* 10.11. 

Tbe composition of crv^tiilliz*^d bfiric acid (also aiUeti boracic 
acid)^ is expreHseil by tbe forninbi H^HO, ; but iit a teiiipeniturc 
of 212** F. (UK)*^ C) tbis eoniponiKl l<ise.s tbe elementi* of water and 
yields metabonc aeid» lllin^, wbirli^ by furtber loi** <>f water at 
higher te mpe ra t a res, beer jj iie^ 1 >f j r t e a ii h y d rii le , B j(>^. M etab< >ri c 
acid existe in the jets i>f steaai (jHtiutroifj^ or »n(fi/mil that issue iVom 
the earth in t*i^me dis^tricls of Ti*s*;iuiy, ami it e<illei't« in tbe wtiter of 
tb e iittjo n I ( 1 1^4 Kai M o r I i tt I e la k es ) fo r ri i ed a 1 1 be o ri fi ee« o f Lb e stt^im 
ehannelrt. This arid ru|in<i evji[Mjrated by the aid of the wai*te 
natural steam ^ mid mutruliMMl hy iidditioii of widiiiai eartmaate, 
yields borax. This salt i^^ usually regartltHJ as sodium tetralMifate 
pyndjomt^, NiijH/),, lf»Hj), {i'itdu Borm, IT. S. P.), atiab^gous 
in a stmse to potsix^ium diehroaiate, K^Or^U,. Native borax or /m- 
rvi/, and other lM>nit4\'*, jirc al?H» found in Thibet, Nevaibi, Ptru^ 
(Thili, andt abundantly, in (Vilifornia in the tN>h>rttdo dii*triel. 
Californiiin ln>rax in represented h» forming' large |M^rtion« of the 
ery^talline lied of a driecj-np lake* Btjrax is also made on a tar)^ 
scale by t»oiUfig native calcium borate with sodium carlwjnate. It 
is ftouietiuiea terTne<l sr>dium t»ilKjrate. It (K'ciir» in transparent 
colorleAS erjstals, ^jmetimef* slightly efflore,seed, or a white «j<lor- 
\tm f>owder, with a weak alkaline reaction ; instdulde in alcohol 
(90 jiereent), scduble in 25 times its weight (*f eoM^ and in half 
itiB wei^'ht r»f lM>iling wntcn 

Fused borax readily <iissinvt^ nictidlic oxides, m will have beon 
noticed already in testing for eolmlt and mungunt^se (conijmre 
experiment 3, p. 140, and experiment I^, p. 142). Hence, lies^ides 
Ud UMe ia medieine^ borax is employed as a du% in refining &ud 




^^Wl 



»- 



BORATES. 



319 



other m c till 111 rjric, and in I'lraniii^ njieratioiis ; it is also an ingre- 
dient itl tftiiri'h glazes. iiftjnritum Boro(f/t/rrrini^ U, S, P,, is 
obttuned by adding boric imd to glyt:erin beati-d t^» ^ temperature 
not exceeding ITiO*' V. Ihtmx boney biruied of 2 parb^ cif Ixirax 
t<i lil «i' honey, i.s a very old imtiseptie for the nioutb^ id' infuutii 
Iruubled l>y tbe gnnvlb eidlcd *'tbru.sb/' 

(^uantivnkiicf'. — Tbe aeid raclit-al oj" the borate^ri Ls trivalent 
(B<»,"') ; that i>f the meUibiirateii univalent (\M)/). 

Experiment 1, — Tu a hot cou€entrated solution of liorsix 
aild n few dri>(if* of sulphiirie acifl and set a*side ; on cooling, 
erystalliue scales of borie fieid» IIjBOj {Acid ant liorknm, 
V. 8, p.), are obtained, Tbeiieid imiy bepnrified by <'ulleet- 
ing on a filter, j^ligblly wa^^hing* ilrying, digesting in bot aleo- 
hol, filtering, hikI setting aside ; pure boric aeid is dejxisited. 
Tbe acid may also lie cryt»talli;ied i'rom water. 

Borid^ add occurs in colorless, pearly, lamellar cry«tal» or irregu- 
lar raasses of erysUda ; nnctuoiiH to tbe trmeb ; tjiste fidntly bitter, 
leaving a Bweeti^h aOer-rtiivtir in the niontb. S^ihdde in 18 juirtH 
of water, in 4. 6 ofglyeerinp ii» 15,3 of tikobol at 2r»^C., and in 3 
of iH^iiing wattT. It changes tbe mhtr of litmus to wine-red in tbe 
eolii, a bot i^atiirated polutitm giving a bright nnJ e(^lor ; tunneric 
pajM/r, moistened with aJi ai^jneonn jwdution, i ven when nligbtly 
aeidululed with bydrochlorie aeid, beion*en brcmnisb-rrd on gently 
drjing, and tbi;* color cbanjjes to a green is>hd)la<k il" wdntion of 
pota!*«*iuin bydr<ixide be added. The solntion in aleobo] hnrai* 
with a fljime tinge<l with green, eKj>f*cially when the srdntion h 
aeidubited with f^nlpburir aeid. Borie neid Ikpiefies when warmed, 
and on careful beiiting lost's 4'?.n [K*rc<^nl. ol" its weight, the pro- 
duct jMdidifying on cooling, to a brittle glaAs-like nnii*H. 

Boric aeid is a very weak at-iil and only sbrwly ilerompost^s* ear- 
bipnatcs : a wilution of bortix poi^st^s^et* a stnjn)_dy alkaline reaction. 

Fkirie acid h extonaively used ii» an aiitisciitic in the preserva- 
tion of f<KMlji, especially in the production of **mild-cured*' bacon 
and ham, etc. 

Experiment 2* — Mix togctlier 1 fwirt of lM>ric acid, 4 parts 
of acid |K)tai«ium tartrate, ami 10 to 20 of water ; evajKinite 
to a syrupy eonsiHtenet^ r^pread on plate*! and s^t aside for dry 
»eale« to form. The resulting Hubstance h lar more readily 
iolttble in water than either of it.*« constituents, and h known 
§§ p&taHAinm itoriy-tttrtralr, or m(Me eream n{ tartar. Tbe 
Pruiwiati InrtnntH fMfnixaftin differ?* from the foregoing Preiicb 
variety in containing 1 |>ttrt of tM/mx to 3 of acid ix»la^.s nm 
tartrate. 





ii20 THE ACID EADIVALS, 

Aualytlvtil I^eactions of Borates, 

L Dip a piece of turmeric pafjer (paper soaked in tincture 
of turmerie tuhersi {imi dried ) into a solution of boric acid ; it 
18 colored lirowu-red, ii^ by alkalies. 

The usual mode of iip^jlyiuii: thiii testis as follows: — Add to a 
w)IutJoii of any Iniriile a few dropw of hydRK.4drjrie arid^ immerse 
Uiilf of II aiip of turmeric piipir in lliu li<iuid, then dry \he |mjHT 
over a Hiaisi'ii Ibmc to dcvcldp the brnwii color, (('nun iitrat^^d 
hydriK-hlurir aciil ur ferric Lhlonde would |in»duce a sfmiewhat 
jii Ml i la r c lian ge < i f c« i\ o r. ) ] ^ la i; e a dn yp i i f i^od i u m hy < i ro x hie i^ d u - 
tion *iu till' browned turmerit.' paper : a dark }i:n\'n erdur i8 jiru- 
duecd. 

2. To a fragment of a liorate, pyroiMirate, or metalKirtite 
(borax may he used) iu a sumll dish fu' watch-g'bi^:^^ tidd a 
dro]i of ctjuceutratcd s^ulphurie aeid and tbeu a little alcohol ; 
warm the mixture aud set Hre to I lie alcohol ; the rej?ulting 
dame is tinged green at itii edges by the volatilized metalxiric 
aeid. 

The liquid should be well stirred while burning. Salts of cop- 
I (fraud some metallic chlorides [in>duce at+oiticwhat Bimihxr color. 
The tlame-teHt uiiiy alr^o hr applied to a siiudl quantity of a mix- 
ture of tht" borate with hulphurit' aeid on a jdatimim wire. ttl}*- 
eeriu may he u?*ed instead of s^ulphune aeid (Ileis)^ the reJietion 
with borax being, aeeordiuK to Duiistaiu, the tiirmatitdi of jejlyceryl 
borate, rjT.liO.^, waiter, and wudiuia metuborate ; ttie glyceryl l»or* 
ate and water interacting: ini mediately tu form boric acid and gly* 
cerin. If tlic bonix and the jfrlyeeriii are buth aiihydrou** nolx)ric 
arid iri formed i^ the water resulting from the dccomiiositioii is 
immeilialely voliitilizcd by the heat. 

Otht'r Annhjiiml RencfionH. — In a moderately eon eeu I rated 
solution of borax* a barium mlt product*s a white precij>itate 
of barium metaborate, Ba(BOj)^, stduble in acids* ami certain 
salts. Silver oifrate also alford^s n white precipitate of mlver 
metaborate, AjjBCX, soluble in nitric aeid and in anmionia. 
Calcium chloride, if the solution h not too dilute, gives a 
while precipitate of calcium wetaborate, Ca(BUj),. 



QrE-^^TIOXS ANI> EXEllCISES. 

IlliiHtnUe tlir r^lritinns of vatitKlinni to tiitrojri'Ti and Oi phHsphonis by 
foriTiiilii* **( eutii^MUJiids of viuh tAvinvu\. — ]k'>rr\hr the nrrp:initiim of 
tiomv. — ii'wc the tVirmula- of tM>ne acid metabctrir turul, nwd iKimx*^ — Men* 
tion the tesU fur homtcsA or mctabomtes. 




BENZOATES, 

The foregoiiifj umh and nalts comprise those which are 
commonly employed in ordinanj rfiedical or phai^nacentJcai 
operathnji. llwre are, hftwever^ jntmij others u^hich are aveaHion' 
ally metl. The chief of these will mm he a ho tily noticed ] they 
are arranged in alphaheti&al order Ui facilitate reference. 



SALTS OF EAREE ACID RADICALS. 

Benzoic Acid, IIC\Hj^(\, and *)thi:h Benzoates.— 

Slowly heat a fru^nneot «»f liejiwtiii ((luin BtMijaniiu) {Benzo- 
tnntit, l\ S. V,y ill a Ii'sL-ImIh*: Iku/.o'ki iicid {At^fdum Brnzit- 
ienm, U. S, P.) rist',s in vii[w)r \u\\\ fnutlmHe.s in smiill, while* 
ii'Htliery i>lute^ ami iietMllt^a uii the ^mjI mlk^ of the tube. If 
the iK^nmiii is first iiiixefl with twice it* weight of aautl or 
rt)tighly |>owdereJ piiiJii<*e-8toiie, ami the heat very ejiUtiouKly 
ap|>lie<l the prod net will he less likely to he liuriit, ami a larger 
quantity will be yielded. Uj repMited suhlimatioii 10 to 15 
|»ereeut. may he ^ditaineil. 

A more eeotiomieal proee.sa ih to hoil the benzA>in with ooe- 
fotirth its? weight of ea lei urn hydroxide, fdter, ct:iaeeiitrate ; 
<leeom|»08e the dis.si>lved calcium benxoate by adding liydro- 
chhiric acid ; colleet the prccipitattKl beuw)jc ackl, press 
l>etween filter-pa|ier» dry, ami sublime in a tube or other 
vessel. 



2HCm,0, 

(Impure) 



+ 



C:«(C,H.O,), 

nuctiim 
benjoiit« 



Ca(OH), = 

CiLlctum 
hydmxido 

+ 2HC1 = 

HydrofhloHc 
acid 



Ca(CHA). + 2H,0 

Oalciiim Water 



CaCI, 

Cklcium 



+ 



2HCH,0, 

BeniftJc Held 



There is alw^avR aKHOcfrited with the product a minute f|yaiitity 
of a mixture of volatile oils of agreeable odor, sufj^estiiig that of 
hay* aad yielding, aeeonliiig to Jaeolwea, methyl In^nzoate, 
guaiacol (inethnxycateehol), eateehol,, aeetylguaiacol^ henstyl ben- 
swmte, l>enzophenone, and benzfiylguaiaenh 

Bcnsuiie aeid is a!;**! prepared oo a hirge seale artitirially frnai 
na|>hthalene, one of the eryMUdline hy-prcHlucts ia the distillation 
of eoal r<»r gas, The aaphthaleue is oxidized by nitric tieid to 
naphtha lie t»r j^bthalie aeid : — 



C H + 80 = 

N'AphUiiucne Oxyf^i-n 



HC.H.O. 



HC,0. 

Oxaifr luid 



^^umatrnhcufjiiSfi (cxcUtditig wrxMl) is mluble ia ether, and the dili- 
Mitfeil »*iib«tJMicc yield* 0.0! percent, of anh. 

21 



:}22 THE ACID RADICALS. 

The fththalic acid is neutralized by adding lime, and tbc 
calcium phtbalatu in boated with faleiuui hydroxide far several 
bourn in a cove red vet«el at a k'mperaturt" fit about 640° F, 
(3S7,8** C). Ualciuui Ixuatjute and earbonate are formed, and 
benzoic acid in set iree by tbe action ol" bydrockloric acid on the 
mixture. 

2CaC,H,0, h Ca(OH), - CaCC^H.O,), ^ 2CaCO, 
Calcium rulcium Calcium Calcium 

phthalale hydroxide bvuxoato carbonate 

Tbe cryatallint? dep«»sit fonnrd when nil of bitter almonds 
(benzoic aldehyde or benzaldcliyde) is exposed tn tbe air ia beD- 
zoic at id. 

2C^H^G0H + O, = 2C,H,C0()H or 2H(\H,(>, 

Bcnmldehydt^ iixygvu lleiizoic add 

Pure i^ublimeiJ benatjic acid is alsii ubtaiiifil fntin bippuric acid 

Jacobseii hm prejmred teizoic acid Iroui briizotrichloride 
ftrieblorouK'tbylbenjCfue, {\ Hj,CCl^, one of tbe tricblorotoluenes*) 
by beating wilb jflaeial acetic acid and tauv ebloridr. Thiii aeidt 
if not very highly purified, omy give a ^recu c<ilnr to tbe Haute 
when heated on platinum wire with a little copper oxide. In 
artificial benzoic acid tbe fragrant volatile oil characteristic of the 
acid from benzA^in is alisent. 

Propertiea. — Benzoic add is slightly .^>luble iti cold water, 
more «<:> in hot, and readilv s?tjlulde in nb'ubol (ftO |jereeiiL). 
It melts at 25(K5^ R (121.4^ C. ) and boils at 462*^ R 
(238.H^ C. ), volatilizing witbouly ii «ligbt rea^idue. Heated 
with lime it yields benzene. It dissolvi^ in cold sulphuric 
acid without floconiixMitiou, and is de[H»sited again on dilu- 
tion ; the traces of odoriferous and other sub.Htanecf* jiresent in 
tbe acid obtained fnmi benzoin only slightly etdor the Huid, 
even on warming gently. 

Official benzoates. — To n little benzoic acid add a few 
dmpp of ammonia water orof Bodium carbonate solution ; Ihe 
iu."id readily dissolve-% forming tbe corresponding l>enio«te 
(Ammonii betizotii^, U. 8. R, NHjC,H/^,, or Sodit BensooM, 
U. 8. P., NaC,H^Oj). With ammonia water the reaction 
is: — 

HC\H,0, + NH," = NH(\H,0, 

Bcniolcacid Ammonia AiRmomion l*t*n«oat« 

On evaporating the swdution, which is kept slightly alkaline 
tbronghout the eva|>oratioii by the addition of ammonia. 



J 



CACODYLATES, ETC. 323 

crystals of am m on i urn benzoate are deposked. Beii:&oic acid 
aim interacts with other ulkuliiie Htjuids, ibrmiiig l>eiizoate8. 
IJthiuiii Benzrmte { Lit hit HenzmtH) is offieial. 

Test for bemzoates. — ^To n solution of a l>enstoute add a 
dn^ip or two of i^ylphurie or hydr<x*hloric add ; a white crys- 
tal line |>reci|>itate of henzoir fieid s*^|>arates^ To anotlier 
|>ortioii of the solutiou, carefully made ueutral if ntH*esflary, 
iidd a drop or two of neutral »i>lutioii of ferric chloride ; a 
rcddiifih pre^^iijitate of ferric benzoate results. 

Cacoovlic An I) (t'H j.ArttXOH.—This in a (TVwtftlHne acid 
whirh 18 formed on exprisure to air of ciu-odyl oxide, (CH3)^Ak/J 
(Cudet'H fuming liquid), tui ext^'eedingly pnisunous and evil-smt4I- 
ing liquid [innkuTd liy hetitiiig ii mixture of :irs«^nons anhydride 
and jMitassiurii iR'Otate. Sodium ctieodyhite, (('HjiyAnO^Na, -iH^f*, 
ferrif' c>m*<wlyhtt<% [(( 'll3)jAj*Oj]jFt% and »tiu*t' other stilts Jtre now 
ane^l in medieine. 

A »idt HoiiiLwhut analogotifl to Bodium cacodylate, corre«poadJng 
to tbe acid CtIjjAwO(()H)^ (mcthyl-anienie acid), nnd n^prefleatcd 
by the fommla ClI,,A8<){(>Na)j, r>H;0, has? heen intrc>durt*d into 
medicine under tin- ntiuic firrlmtftL T\m wll hi*>i been ealleil 
}**xliam methy ars*nate, a name which in quite iiiufjprr^priate a.^ 
the salt i« not au arsenate. 

('ARMtNtr Acio, <_*,JIj/) — This is the eohirinf^ prineiph* 
(about li) jTR^reent.) of the dried female eoehineiil insert, (hems 
fhrfi\ (ihct'ttjt, U, H. P, ). The mrmhir of trade, when uaadul- 
tt» rated {we P. ./., 18o*»-(j(), p. Mi\\ is earmiaie aeid ai^oeiate<l 
with 2 or 3 percent, of uluminaand lime, or, oecnsionitlly^ of tin 
oxide or albumen. It should W-. wholly s^iluble in ammomia 
water, giving a eletir, rieh purple lit^uid. Carmine with French 
chsdk, or dtarch, eonstitutcs face rouge or anium/ roNffe, 

Merrick testw t!ie relative value of §everal winiple^ of coebineal 
or earmine by oli**i*rving how mneh solution of potassium perman- 
ganate ift required to eliarige the color of a dt-i'oetion to a faint 
pink, The silvery eoiitin^ of cochineal is a wax, eftereriiK 

t'lcriiAKJC Acio, H,C,„H,^(>,,, i.s ihe hitler prineiple of Iceland 
UK>Mrt. Jn the lichen it i.'* asaoi'iated with much fltarch. A fatty 
aeid, lieheiistearic acid, i» also present. 

i'lNNAMIc Acio, r^Il^n(H>H.— IViizoic acid is distin^nnHhcd 
frotti an allied acid, cinnamic acid (f>ceurring in Bal^iams of !^Tn 
and Tolu, in Storax, and s<»me times in BcTiKoin), by not yielding 
ben/jddehyde, C^H/'OH (oil of hitter ahnontjs), when distilled 
with n mixture of potai^iuni dichromate and sulphuric acid, or 
when triturated with half itn weight of potaj^sinm pennanganatc. 
Old hard balsam of t/>ln yields eiunamic »cid (m iMtiling with lime 
and water imd preei pi tilling by the addition of hydrochloric acid, 
Jaoobfien mak^ cinnaaiic acid artidcially by the prolonged inter- 



324 THE ACID BADICALS. 

action of glacial acetic acid and bemsodicliloride in ihe presence 
of zinc chloride* 

Cyanic Acid, HCNO, and other CYANATiis. — ^Thc reflucing: 
ac t i f m * > f I ji I liii^m m cy n 1 1 i i k\ K C N (o r tc rrm y lui i d c , K ^ F c< '^X^) on 
many nietjilJir oxide**, it« due lo the rcadint^s^s wkli which it Uikes 
yj» oxygen and forms cyanate, KCNO, 

Experiment. — Fum a few grains of jiota.ssiym cTanide in a 
*in\all jMireelniii criicibU* aorl add powdered lead oxide ; a 
glotnde of metallic lead h at oni*e formed, ext'^HH of the oxitle 
converling the whole of the jxitiuriiiium cyamde ioto ix>lasi?iiira 
cyanale :— KCN + PbO — KCNO + TK 

I'lihiH^iitiui cyuJiale, K('N( J, at li^tter, lead cyaiiate. Pb(CN<>)j, 
trwtt*Hl with junmonium Mulpliiit**, yields annnonium cyiinak*. 
Nli^CNd; and f^ohitifui i>f aanutuiium cyaruite, when eviiiioratcd 
to dryness, leaves a residue of «r*vr, CON^Ii^, the uiont iinpiirtant 
ciJiistituent of urine, iHid the chief form in which tlie wa*ste 
nitrngpn is eliniinated from the animtd systcuL The process will 
Iw more fully des4Tihed subsequently in cnnneetion with urea, 

EsiBKLic Acid, IIC,Hp(J., aj4>ears to Iw the active principle 
of the venuifuge fruit ot EmheHa Hibes and Embelia Eohusta — 
Warden. 

Formic Acid, HOHO,. The red ant (Formim ru/a) and 
several other insects, when irritated^ ejei't a fttron^^ly acid, acrid 
li<|tiid, which contjiirm formic acid ; the acid is aim contained in 
the leaves of the stinging-nettle, 

Freparatioii. — F'orniic acid may be preimred artificially by 
heatinsi; eijiial weJLdih? of oxalic acid and glvcerin to a teni* 
]>t^rntnre of from 212° to 220° F. (100^ to 104,4^ C.) for 
Hlleeu hours, atnl then di8tillin«: ihe niixtiire with a consider* 
able volume of water. The formic iicid, mixe<l with water, 
slowly [wiRseH over, glycerin being re^'enoruted. The dilute 
acid may l>e obtained in a concentrated form by neutralizing 
with lend carbonate, filterinjii:, evaporaling to a small volume, 
collecting the iiepjaited cryatalliue lead t^^rmate, drying, 
decomposing in a current of dry hydrogen sulphide, at 212° R 
f ItiO*^ (A ), and reetifving the ri*siiltiug syrupy acid from dry 
lead formate. It {should \w fluid at 48° F. (8,9° CI) and boil 
at 212'' F, (100°U). The following are the chief reactions:— 

C,H,(OH), ; HnO ^ C,HpHC,0. + 2H,0 

Olycerln Oifilie ftcld 0\yi^t}ry\ h>dro3tyoi«J«tc Water 

("Jf/>Ht;,0, + 2H*() ^ C,H,(OIi), + HCHO,+ CO, 

rilyreryl VViiler Ulycerln K«»rmic Cu-tiotiic 

hjrdroxyouiliiio acid anhydride 



m 




I 

I 



I 
I 



FOUMATES, Era 



Fomiic At'iil may he iiiHtructively tknQgh not eoonrimiciiUy jire- 
puroil by the iixidatiiin i>f melhyl uJc-ohol (wood-spirit), jtisl na 
acetic add ami valeriaiiic acid are obtaiiicnl frum ethyl ah-tihol 
and amy I alcoliol restpectively — 

CH.OH + 20 ^ Ht'OOH ^ Jlp 
Methyl uleohul Oxygen Furmie olv'hI \ViiU?r 

Te»t*. — Ffimiic aeiU dties nut idiar whiii hi^aied alone or with 
sulphuric acid. Iiut s[diU up into carbtniic oxide and water. It 
ia recognised hy iliis property and by its reducing lu-tion on wait*! 
of gold, platiuum, luerenn^, aud Hilver. It is t^idid below 'd2° F. 
OP C). 

Gallic Acid. — S^e Tannic Acid. 

Hemidksmu" A<mi», — The sujiptised active principle af heiiii- 
desniiia root, 

llrt'Piiitic Acii>, llCgH^NOj, h a coiiHliluent of hutiuiu urine 
(much iiicrcused on takinjj; benzoic ftcid)^ but is prepared from 
the urine of the borne (heiiee the uame, fr<ini irrrrw, hippm^ a 
horscf, or iK-iter, from that of the cow. To wueh urine a(Jd ii little 
milkofliine, boil for a tew miuutejs, remove precii*itatcd |dios|>hates 
by filtrati<ui, drop in hydriR-hloric aeid until tbe liquid, aftrr well 
Ktirring, isexnetlyncutrid to tcst-paj^er, coneeutrate to aljout niie- 
eightb the original volume, and adil exeef^ of eonccutnttcd hydro- 
chbjric acid; ini]mre hi[>purie acid is <j( posited. Fnirjj a hoIu- 
tioii of tlie impure aciil in hot water chlorine rein«ivcs tlic cohir, 
and lite lit|uid depjwit"* crystiils of pure hip[n»ric acid on cooling. 

Tf*tA. — Tfi a jMdution of a Ijijspurate add neutral Holnti«»n of 
ferric chloride; a brown precifntate of ferric hippnratc resnlts. 
JSoluble Bilver antl mercuronn saltn give wdiile j*reci|dtiite,s. liciit 
hippuricacid in a tet^t-tiibe; it cbars, Iwiixoie acid sublimes, iind 
vapors of charaeteristic odor nre evolved; they ennlain, among 
other priKlnets, liydrocyanie held jtml a substance smelling H<nne- 
wliat like Tonka bean* Tbe crystalline form of bij^fHiric acid is 
cbaracteriMie; it will be dewribed in connection with the subjtn^t 
of urine. 



QUESTIOJfS AND EXEBC18ES. 

GIre the prepanitioQ, comptjeition, properties, and testa of bi^niujie acid, 
employing pquatioiis,— What is the nature of camiiue?— Name tlit* hitter 
prinriplcof Iceland "mcMw." - How is potiiaHiuui cyaniiuj ppciian-d, how 
converted iul«i an Animonimii salt, nnd whut arpi th** Tcluiions uf Ibc 
Iftttrr to urfcft.— Give th« furmalif of cyanic arid, aTamoniiim cytinato 
und uiT*i-— What i,H the form u hi (if formic acid?— IVhcHIm^ the artiHcbil 
pnMluctioii of fortiiic acid.— What is the relation of formic acid to wo*)d- 
spirity — State the sources, characters, and tc8t« of hi|i|iuric acid. 



RrnHOFEBRocYAKlc Acip, H^FeC,N-> or H^Fe(CN)„, akd 
OTHER Fkhrocyanides, — The ferrt>cyiinide of most interest is 



326 THE ACID RADICALS. 

Pc^taaMiuii] FernieyimiiU\ Ptifn^mm Ferrorijattidrtm^ U. B. P., 
'yellow firtJSHiatr iif [hjUihIi,'* K^F^iCN)^, Hli^O, tbt* formiitiuii 
of whk'h wii^ allutleil ttt in rniiiiL't'ti^Mi mih hydnM-Vitiiif acid 
(*ftf |K ^ till J. It cjtiiinit be n-^nU'ii aw sun|*ly H fjtiuble i»alt of 
potafewium eyjinide with fernjus cviuiidt! (4KUN, F*_'(ON)j), itj^ 
diemit'iil |)ni]K'rties living I'litiridy difil^niit fnnii ilmse of either 
of tht^e subj^tjiiiceH ; monHivt-r yiilike |M*tus.siu(ii tysinide, it is not 
poiminoufi. Mc»st of the retiiitir>iiH jwiint to tht:- eom-hisioii that in 
it iron atid eyamrgen are iiitiaiiitely united to ffinn the quticlriva- 
(ent rmlieal ttjipropriutely teriued /rrroeijanmfm (Fei*^Nj'"^ A 
solution i>f 10 graujnieH of [jotiUM^ium ferro^-yaiiide in »ulfidt'nt 
water to measure 100 Ce. in the official rotasHiuni FerriK^ynnide 
Te«t 8olution. 

Tests. — Many of the ferrcM?yanideH are ins<duhle, and are 
therefore preeipitated when sulntion of |H*ta.««inni ferrm-yaiiidti 
in added to the milis of ihe varioua metnlf*. The precipitates 
protluoed in solutioiifl of iron and of enpric sjilts, heitjg of 
ciiaracteristic color, are adopted as tests for the presenee of 
theee metals or of ferrtK^vanogen, na the case may be. To a 
sohitioii of p*tji*4iurn ferroc}aniile add a lerricgaH; a dark 
blue |>n/c*ipitate of ferric ferrtM^yainde, Fe/" (FeC^Nj)/'", 
Prufit^ian Idue, is pnMJueed^ To another |Knlion add ^Intion 
of a cnjirie salt ; a redilish-brown prei*i]>itale of eupric terro- 
cyanide, CUjF'6(CN)j results. 

Note, — ^The ferroeyan^jgrea in jMjtassiuni ferroeyaaide ix broken 
ap when the bjiU is* heateil with sidphnrie aritl, riithonie ojidr 
being evolvixl if the aeid is eooeentrated (tlmt m, ordinary oil of 
vitrird — H.^O^ with 2 or 3 percent, of water), and htjdroryanie 
iirfV/ if dilute: — 

K.FeC^N^ 3H,C ) + 8H,n + 8TT/i(). = 4KH80, 4 FeSO^ 

SK^FeCjN^ -i- mj^O, = FeK,FeC,N, + CKHSO, 
+ 6HCN 

HYDROFERRiCYANic AoiD»H,,FeC^N^» or H,Fe(CN),» ant* 
OTHER Ferrk'YAN1I>i«. — Pas8 chlorine slowly throntrh as^du- 
tion of potassium ferroeyanide until I he litiuid. nfter frequent 
ahakingi ceases to pve a blue precipitate when a minute j»or* 
titai is takeQ out on the eml of a irhiss nxl and bn>iiK'ht into 
contact with a drojj of dilute j^lnllon of a ferric salt : it now 
ocmtains Potaasiuni Ferricyauide K^FeiC'N)^ *'red prussiate 
*»f |xitash," as it is called from the color of its crystals, Excties 



L 



FLUOR! DE& 327 

of fhloriiie must Ue eareFiiUy avui^leci, as cyHnogen chloride 
ami other coiri[>iJUtHlH are theij formeiL Such a rt*^ult does 
not ensue if hroiiiine he used iiLstead of chloriue, hut this pro- 
cess is less ecouoiuiuah 

2K,Fe(CN), + CI, -. 2KC1 + 2K,Fe(CN ), 

NoU. — The reiiiovid of om*-!uiirth of the puUi8i*iuiii from the 
fernjcyiiiiide is here uiTiniipanietJ t>y the lotL version of thi^ quafi- 
rivaleiit radiea! ferrot!yaii(»>reri (Fe( J^N^)^'", into the riuJieaiyVrn- 
(riftiumjcH ( FeC^N^)^'', whieli i^ trivalerit. I5<'sidei* by tlje aelion 
of chjf^riue, tJie i onversifjii fif pol^iK'simii ierr(»cyaiiide into fern- 
cyanide eaii he etftH'tt'tl hy the art inn of one ur other i>f a vjiriety 
of oxidizing: agents. 

Tests. — ^To a .dilution of f>otiiStsiiini ferrieyanide ndd i^An- 
tiun of ferrous sulphate ; a diirk-ldne preei[)itale i.s produee<l. 
This precijiitiite w ferrous ferricyauide (Turuhull'« blue), 
Fe,-tFeC.N,);". 

2IC^,Fe(CX)^ 4- 8FeSO, ^ 3K,S(>^ 4 Fe,(FeC,N,), 
Potftfliiiiiin Ft»iTfius rotii^iiium TurabuU's blue 

ferrfcyitiiide sulphate sulphate 

A solution of 1 part of potassiiini ferricyauide in alK>ut 10 of 
water foruL^ the (jtfiriai Fotjist^iuni Ferricyanide Test Solulion. 

HYDROKLirORJC Af II), HF» and OTUEK FLtTORllitX — 

Hydrottuoric aeid is t-hiefly uj*ed for etebinjur ^\iVi^s. The 
openitiou, [lerforujed an the nnuill scale, alnti ei>Ui4titute,s the 
hest test for Huoritie, the ncid radieal of the tlu*irides. 

Experiment and Test, ( '^mt the *'onvex >iide nf a wnteh jt^lasH 
(preferably one made of hard glass) with u layer of lieeswax, 
hy first heating the i^dtiKs and then rtihhiijg the wax over it. 
When the wax is cold, write throij«,'h il with the point of a 
jun (or other iastruinent which l^ not hard euough b» scratch 
thegla^) m uh to lay hare wiioe portiiain of trlatts. I'lare a 
few grains of powdered fluur-spar (ealriuin Huoride, C'aF^, the 
commonest u at u nil tluoride) in a suuiU lead hni^irv (orplalinuni 
erudhle), add a few dro[i6 of sulphuric acid, cover the biLsiu 
with the prepare*! j^laas waxed **ide downward, and very 
gently warm the bott4>in of the basin in a fume-cu|>hoard in 
Bueh a way as not to melt the wax. After a few minutes 
remove the ^hiM, wa^^h the waxed side by [louring water over 
it, S(;rape off most of the wax, then \^arm the j^da-ss and wipe 
off the remainder ; the ^las^s will he found to 1k» etched at the 
phioee that wore laid hare hy the removal of the wax. The 
hydrotluoric acid liberated by the action of sulphuric m^id oq 



32« THE ACID RADICALS. 

the tiiior-spar haft vtiten hiUj or etchrd (from llit^ < tt^rimiu 
aUen^ to cornwle) the glass. 

Tht* falcium rtimrkle aiHl Kul|ihurif at id yield liydroflimric mid, 
tbuii :— CuFj -f H,8U^ = CilSO^ -j- 21iF. The hydr^dluririf i4c*d 
g£ts and the .silim of the glu^ then yield silicic and flurot^ilicic acids 
iiiid wiiti^r, thu» : — 

12FIF -\- 38iOj = H.Si<\ + 2H,BiF 4^ 2H,0 
Hydrofluorie 8llkui SilkHc Fluuf.llkTe Water 

ticid acid ackl 

The HiHca being removed from the glass, leaves furnivvt* *»r elchod 
liortimis. 

The a(|up<ms ty>lutitin of hydrotliinric acid, u»e<l by ett;herH» nnd 
ctmimoiily t*Tmed »imij|y hydrotlufirrL acid, *ir '*rtuuric'' acid, is* 
()ri*part'd in leiwlen ^tilln and rrreivers, jiiid kvpi inleiideii orgnttu- 
perclm ijollk*^s. Hydniflutirie uuid rajiidly atUuks iiny Kuhjitance 
of whifh lHittl€H an<i baHins are Uduully made exeept lend and 
gwttit-|>ercha. It is also without action on platiiinui and Hnor- 
HpikT, It quii-kly crauterizeft the skin, pmdueing a pain fid, i*lovv- 
healing 8<ire. A mixture of hydroHuoriu aeid ajal aiJiin<*Miuiu 
rtunride, known as "white acid," in al>o used for eteliing pjlass. 

Ex[M'ri mentis by Mei«hin» show that anhydrous hydrogen fluor- 
ide has no action mi absolute ale<drol kdow 21 !<'♦** F, (Ki^K^C), 
Above that teuiiicrature intenietion takes (date ; uad at 410** U> 
428** F. (210° to 22IP V. ) about :^n jiereent. of the ^iu^ in eHterified 
in three hours, and gmsetins ethyl lluoriile ujay liv colleeted. 

Quanthnirtifr, — Fluorine, like ehlorine, bromine, and iodine, 
iH univalent (F'). 

I'Jfwnne l\ikn Imh^u isolated hy elect n»lyzintc hydrnrtnoric aeid. It 
irf a p'reenish-yellow pm with an irritatin)^ od<>r» It com1iira>s 
with ^reat readiness with all eleiiientH exee|d ox>'p^en. By emding 
and efaiipre*vHing the ga;?*, Moissjm imij Dewar have obtaiutHi IIuik 
rine as a pale^^yellowiflh liqnid. 

Hypophosphokoijh Ann, H,PO^ or HPTT/\ and other 
HYi'tn'Ho?*piiiTl'>i. — lioil totretherin a fiinnM'U|dioard, two (»r 
tliree gniingi of phc>spboruy, three or four grains rdN*alHuni 
hyrlroxidt% and about a quarter of an ounce of wat<?r, nntil 
hydrogen phosphides are no longer evolved. The volatile 
produetJ? of the interaction are trihydrojc'en phosphide (or 
pbosplmretted hydroireu ), PM,. and a small quantity of the 
vfl^jor ofa liquid phosphide, F^H^, The vapir of the latti^r 
ipfniles spontaneously in contact with air, and iiujwirts t>o the 
gaseous mixture the prnjierty of spmtaneous inflaramability. 
The calcium hydroxide tnti^t not be in great excess, or tlie 
hypophosphite produced by the interaction will be converted 




I 
I 

I 
I 

I 



II YPO PHOSPHITES. 

into phosphate ns< fast iis fornieil Tlie iiiixture, litu^rod, x\\\A 
exc^eea of lime remcived l»y rneaustof carlMHiie uiihytlriJe* yielib 
a solyticjii of cakiiini liyi»<>l*hosphite, Ca{ l*!!./)^ )j { Ctihil 
Hypuph*mphii*t U. 8. Pj. Tlie salt luiiy be ol)taiiie<l iu crys- 
tals by eva|)oration ami slow coaling. 

2P, f iillfi + m a(OH ), ^ 3€fl(PHA), + 2PH, 

almve rr:utifjii is the oiie hy which phiiH[>!iiirtHlr<l hy*lrr>^t'ii in 
usuhIIv pr*'j«irecL JT the gun is t«i Ur c<»IUh UhI, Uh- ]ilK»spliuriis 
iinti wutrr may iirrit Ik- ImmIi*! iti a flask milil ajet nrsiMnitiinrr^uj^ly 
ifiriaiiiniiihk' ph(>H|ihnnis vapnr l'sruIK^'^ with steam, inmi the c^^uJ 
of" the atlaclied iJebvery-tuhe. Ht>t e^iiiei'iitraU'"! s<»luti^»Ji of pi^tiit*- 
t*iuui hydtxixitle ur ^ddiiim hvilnLvid*/ m next very j^ra^luully jwairetl 
into the tlask ihnaigh a fiintiel-tnhe previou.nly ii(li:ii iiitu the eork, 
the liquid Iveiiig ki'pt iHiilinjyr. Putaj^sium or^nlittm hy[Hipliosphile 
informed in #ilutioa,^ wliile pimspliurettetl hydrogen is evolved, and 
if the delivery-tube di[^ under water may beeollerted. or allowed to 
Hlowly [*ass up through the water, bubble hy bubble, ho an to lmr>it 
into flatue s|mjitaneon>ly and turin vortex rings of wbite .sm<ike 
whieb arifte one after the other into the iiir and tire t liaraeteriKlic 
of the exjierimeut. A solid hydrogtm phosphide, P,H^, isknnwii^ 

iSfntiuui HtJiHtphoi*phifi\ NaPH.^t)^, H,^(> (*Sijtlii Jft/pit/i/itf.Hpfiljt^ 
W H. I\) is made by the interaction r4' siilutions f>f ealeinai hyjut- 
phospldte and scKjium earbonate, lilterin^ atid evafiorating tti dry- 
ness, tji(PH,() >, H NitJ*(>, -- 2NaPri,(l^ 4 < 'aro^, it is* a 
white, gmnuhir, dt lii|iieseent substatiee. Wlien heatt^l, the water 
IH tirst evolved^ tben liy^lrogen aa<l hydrogen |djos]ddde, and a 
niixture of ^>ditno pvropbMSpliati' aad metapho^jdiate naiairis, 
r>Xaril,(\= NaJVL-i NaPO, f 2I'H, } 2H^. (Kaaimelslw rg. ) 

HlflH^phiiMphoroun Arifi^ hy*lroi:en hy[Hqdj<»s|ddte (Arhhtut //i//w- 
phftMphttrfmiot, V, S, 1\), may bi^ pivpared by deeonij^tisinj:: llie 
rak'iiim i^hII by means of oxalie aeid, or Ipetter, the barinm sidt 
by moans of siilidiune aeid. 

Anfhim IftjiMtphoftphoroHHin I/lfufum is idsu otlkiaL 

f'Wri iftjiHiphftfiphin^ Fe(PU,/).Jj, Mttftt/nui IfypophmphU, 
Mii (Pn.;(Jj),, aiid PotaMn Hij}mphmphiM^ KPHjO^, are ineluded 
in tiie Pliartiiaetipo'ia, 

(/ufninf hfjpftphoifpkiif^ i« prepared by dis-^fdving qiuniiie in 
hypophospborouH aeid, nr by deeoinpo?4ing quiniiie sulphate by 
mcjtii^i of barium liyjMiphos|ddte. The latter is nbtarned <»n boil- 
ing exeens of pure bitrium hydrnxide with ammonium hypopho**- 
phite until all the aTiiiiiouia has been ev<dvt»d. The mnmoninm 
Halt is fftrtned on bringing ealeium hypopbospbite and amnioniun* 
oxalate tijgetlier in i>resejjee of a little ammonia. 

The hypopho«]diites are often Used in medicine in the form of 
syrups {S^tpuit Hypnpkonphitttm, U. 8. P, ; Si/rupus Hypfiphm- 




830 TUE ACID BADICALS. 

phihitti (hmpoftiiu^j U.S. 1\). The Utiii hy|>oj»lj<»sjjhito b u.%xi in 
comieLttiou witli Uii^so HiiltniiQ account of thrir rorilainiug Jisniiitler 
|irt>pt>rtioei {vTro^ hu/jo, ujitler) of <ixygeii tlmn ihv iihfibpliitt-w (a 
cliwin of salts which, in turn, wmiuin lens oxytreii than tht* phii^- 
jihate**). The prefix hi/^m has simihir eignitiraiR-e in sueh worda 
ita liyptwiilpbite and hypochJtirite, 

TestB. — To a solution of calcium or jitxlium hyjHjphosphite 
a*!*! solution of bnriunt I'hloriile, eiilfiuiii chhiriile, or lead 
acetate ; in neither en.**c i.^ a precipitate obtained, i»vhert*a8 
soluble phi>t*pbateH and phu^^[)iHte.s yield white preci|»itate8 
(of barium, caldnm, or lend phosphate or pliosphite). To 
other iKirtions of a hyi*opln»rtphite solution add sHdntions of 
silver nitrate and mercnrie chloride; precipitate^^ of metallic 
silver in the oiie vn^e and of mercurous chluriile and theo 
of metallic mereiiry in the other are produced* (Similar 
reactions^ are produfed by phoj*}>hite^. ) To another smidl 
pf>rtion adtl zinc and dilute sulphuric acid ; liydrogeu and 
hydrogen pbrwphide are evolved (us from phosj)bite«^ To a 
»olution <jf calcium hyfwpho^phite add i^uiiicienl oxalic acid ta 
remove the calcium ■ filter; to the J^olution of hy|xipbof4phorou« 
acid so cjbtnintHl add solution of eupric 8ul|>hate and slowly 
warm the nnxture ; a bnvwn pre<Mpitate of cuprou.^ by<lride^ 
<UiJi^, is priniuced : heat to the hoilinif-|Hiint ; hytlro^en i* 
evolved and metallic! copjwr h set free. Add a nilution of a 
hy[ji>phoHphite to u njixlure of ai|Ueous i(?olution of aiiimoirmm 
laolybdiite with ^^jbition t»f 8id|ihurouH ncid ; a blue iiret'i|H* 
tate results, or in tlilutc s<ilutions, a blue color which <lce[>en« 
on slanditj^j". Heat a small ipiiuitity i»f a s<»lid hvjxjpbo'ij^bitt? 
on tlie end td'a s[mtyla in a (huue, ami m>te the mlor of pht»»- 
phuretted byiln*i(cn and the cimihyHtion of this gnK The salt 
breaks up into j>yrophi*s[daae, wmie au'ta|>hosph3ite, hydr<»trt*n, 
Irydrogrti phosplddr, and wiUer, the offiria I calcium hy[»ophois>- 
phite yieldiiig ab<mt MO jjcrcetit. of residue. 

7Ctt(PH,0,), =3CJa,P,0, +Ca(PO,), + 6Pn, -fH.O + 4H, 

Five grain? of ealeinm hy]>opb(»»[diite, if of |y<K»d quality, 
will alnmd deccdorize a solution of not less than tw^elve grains 
of ptJta'^ium permanganate, on boiling the mixture for about 
ten minutes. Five grains of so*lium hypophosphile should 
almo$t dewlorize not le,s^ than eleven and a half grains* of 
pernmngauate under Bimilar conditiooa. 



LACTATES. 



331 



PiihiKj^iym pernmn^Himte, in acid s^jlutiou, is n\m reiiyced 
hy tlvB wiltititm td' ii plj()s|ili!te Imt uot by ihot of an arthi>-, 
luetii-, or |iyrt>pbi>^|jlinte* 



QUESTIONS AND EXERCISES. 



Oivfl the formula €»f i>i>tas8inuj ferrocyauiile.— Kr»uiin>mte the U*fiU for 
ferrfn'jjitiogtni.— What uns the respective ruactujiii* <if |Kjtaftsiiim t'i'rr<»- 
cyanidc with chir'ci it ruled mid dilute sulphuric lu- id ?— Write eqmtti<»us 
U'liistrativt^ uf the changes L'lftHtt'id in |MjtjisHiiim tVrriK'yiiijidt'^ duriiiif it* 
f4 111 version iiit^rfL^rrieyanidi'* — lly what reuftiniis umy the prt^^i'iirti uf n 
fi*rrit'yaiiide in u «4iliititni be lietinjuiHtrnteil V — State tht-idiJUeivut'ti bvtweiii 
Prushiiin blue find TunibijU'sbhjt:. — IktK rilHs thesoiirct% uiiidtMjfprt^jMini- 
tiou, thief um* of, uiid tust for hydrofluoric acid. — Wbat rouipouiid:!* ana 
proclucfd by hoiliujjc phrmphorua in solution of filkalies? — Givo equations. 
— How istdliydrogen pluisipbide pn part^J? 



Lactic Arm, HCj,n/\, and urnER Lactates, -^Lactic 

tid txrurs iti willow hark (Dutt)- Wbt^ii mitk turns simr, 
^ •dine of its sugar Iras bee* ime t*onverk'(l ]*y tlie lm(^litt^ (widt 
lactici^ i\%\ by the nilro^renons matter, into hrlic iwu] ii(n\ 
liwfm). Other s^acrhiirint^ und HmylH<>ef»ii« HnbRtance-n i\\m 
yield lm*tic aeirl by fernientutiott. Neither hydro^ren lucUte 
(lacrfie aeid j n*»r other hulates are liutrh uned in (treat Britain, 
Preparatioii. — (jileinni lactate and Jaetie aeid may lie 
prepirt^cl vni HiIIowm;^ — Mix to^^etber ei[:ht partj* id' Hijgar* one 
ofehei'Se, thn*t^ of ehalk, and tifty of water, anil set asiile in 
a warm place ( alH>nt Htl^ F, ) f«>r two or three weekw ; a inass* 
uf hitmll crystals id' cateiuai btclate re^^ub^J. Keraove these, 
re€fy>1a!lize fro a* fiot water, tleiM>ni[ioHe \vy niHiai^of Hnlfihnric 
Uf*id (avindin^ exee«s\ ili^^esl itialeoboK tilter off* the caleinnj 
fltil|ihHte^ eva|>onite Hie clear Hiilution to a syrtip; this rej?idue 
m ordinary laeiie acid { Arhfum iMiileum, ILK P/], t^i*. gr. 
L20*j. 



A «yTtip of calciuni laetophosphiit*" is offiriiil (Si/ntpjn* Culcii 

Tr«t, — No Hia^le reaetrcja tjf lactic iieid if* sufReleatly diHti active 
to be repiinled jls a tcM. The erj^talline fnrai orcah'iiiDi taetjite, 
an m.*ea inwlrr the niJcn>Mt*op**, is rharacterii^tir. The pr^Mhictton 
of thin wdt, ami the is<ilution of" tlip syrupy acid it<<df, are lhe<nily 
mc^nH of ideattficution, j*hort of ijuajjtitative analysin, oa whirh 
vslisnct cah Ij« plaeeii. Lactic aeid ia ftoluble in water, aleohot^ 




332 THE ACID RADICALS. 

yjid c'lbtT, but ahnost inrt«>luhl(* hi t'lilurolVirm. It boDly tiligbtly 
c<iliirt*d by eold !^ul[>buric ju'ni Wjirimni with poUi^iiiriipenuim- 
ganaU', it t^'ives i\\v \\i\i>r (it iibb'liyde* 

^-i varhiif of Ittrfie avid Iiilh been ftbliiim^il frtiiii the jiiif e ^jf flesh ; 
it irt k^niii^d narcolnvUv acid (trotii jjupjf, capsoCf earj^ m^rcoM^ flt^h). 
Unlike lactic acid, it yield* a precipitate with wjlutiou of ciipric 
suljdiat^'. 

MAf.ur Arii», C^Hg(.\ and othek Mai.ATK.^ (Irnm malum, an 
a[>pk\i.— Thejiiit'eH of unripe np|iliK, giniseberrifw, rurnint;*, ^ttraw* 
Iwrrit's, grn,|K.'s, and of rbubarli'Mtiilk?*^ eti".^ nmUiiu mnViv acid 
and potitHHiuni auilatc. Whtri iwduted^ malic acid lorms del i«juc»- 
cent pri*^uiatic iTyst;il«, 

TfjifK — I'alciuaiiualatc, i'jit\ll^f)j,, iHr^diibbMu vvaler. bciicethe 
a(jueoiiH solutiuu of malic aciil c»r otlR-r luahilc i*! not |>rfri[dtated 
by liiu«-water or citlciuru cldoridc ; but, on adding idcobtd, a whitv 
precijdtak' in pn>dueetlj uwing lo tbc insolubility of ealriniit nml- 
ate in that liquid. Malati's are prceipitated by load salts ; on 
Wiiraiing tlic precipvtiite of lead nialate wilb acetie aeid it cH8s<jlve«, 
separating out in acicular iT>>tiils iin c<nding. If the niixlun* In* 
heat^ed in absence of tlic acid, the precipitate ngikdutinatc^* and fuw^s. 
Hot ctinceiitnited :^ul[diuric acid i liarH audic aci<l far le«8 rca^iily 
ilnm it doe?^ nearly ull other orjjanie acids* 

Jx^j(/ni</m (CJlgN./),, n^O). — Thi,« [troxiniato prinriple of plan tM 
oceui-s in many vejjjetalde juices, and doubtlej*s [days a veryiin(M»r- 
tiint part in their nutntion. It w deposited in crystaln when the 
fresh juices of aspjirapi.'*, niarsh-niidiow, etc.» are rapiiMy evjijMir- 
ated* Jt in notieed liere because ajalic acid is readily obliiiue*] 
from it by oxidalion, nitrogen beirifr eliniinaled. When itn wdu- 
lion h h»n^ hoiked it is cfinvertiHl into jirnntonium as[iHrtnte, 
Nl 1^* \U^,Nt )^. I>ecompotied by aid of ferments, iiiip:ira|::in, uhsi^rh- 
ing hydrogen, yields iunmoniuin suecinsitc, (NH j/'^H^t)^. 

Me* 'ONir At irn Il^t 'J I J\, ♦>1I,( X — Opium couliiiasmeconie 
add { t rum firjxtoy^ wf'A*o//, a |w*ppy ) pjirtiaUy cofid)itie«l with 
mori^hine. To concentnited infusion of ojiium, neiirly neutral- 
ized with ammooiti, add solufiiin of r^ih^ium chloride; crude 
CJilcium mecx>nate is precipitnte<l. Wash the])recipitate, place 
it iu a 8niaU r|iiantily of hot water ; add a little hydri»tdilanc 
acid ; the clear liquid (filtered, if iiece«38ary) dej>08its »(.*ale» of 
impure meconic acid oi» coolin*^. 

Tests. — To a solution of niecouic acid or other hum rmiite (or 
to infumoQ of opium) add a n^^utral solution of ferric chloride ; 
a red solution of ferric meconate is produced. To a |X)rtinn 
of the mixture add soliiti<uj of corrosive ^uldimate; the red 
coh)r is not destroyed : to another |)ortion add hydnx*hloric 
acid J the color is discharged. (These reageutij atit ou ferric 



METAPHOSFHA TE& 



333 



thioryaimte, which is of siniikr tint, with exactly the opix>site 
re^ulW ) To another portiuu add a drop of a dilute anil, atid 
ImmI ; the cuiliir in not di^^lnirged. (A j^oliitiot* oi' ferric me- 
tato» whii'h is ofj^iniihir color, m de€oiiiix>^doD IwiUog, giving 
a cuiorlesa fluid und a rtwl precipitate — ferric oxyacetate.) 

Tlie normal puliisstjuni, sodium, and jnnnioniuni iMLe<niiitea are 
»olublo in wati:T, tlif iifid nietoniik\'4 very wUghtly S4:»lijhle ; the bar- 
ium, caleiutn, lejul, tvipper^ and silver mcconaU'M iire iiiH<jlubi(* in 
wati-^r, but 6«>Inble in Jicetic arid. 

^It:TAPii(>HPiiOR[r Acid, HPO^ and other Metapiios- 
I'HATiis. — rre[nire phoi*phoric anhydride, P,0,. by bnrning a 
snnill piece ot phosphorus in u ptircelaiii tTiieiide j>hii'ed on a 
phite and covered hy an iiivertefl te-st-glaHH, large heaker, or 
some Huidi ve^^td. AfttT waiting a few ininutes for the phoa- 
phorie anhydride to fall, pour a littJe water on the ptale and 
filter the liquid; tlie prodnet is a *?<4ytion of met a phosphoric 
acid:P,0, + H,0 -2HPO,. 

Tests. — To a solution of nietafdiosphorie acid add silver 
araraonio-iiitrate^ or to a neutral inctaphosphiite achi i*olution 
of silver nitrate ; a white precipitate of silver nietaphosi>hate, 
AgPO^, m ohtiiued. This reaction sythcieutly distingui>*heis 
luetaplui^j* hates from the ordinary phi>s|ihatc.s or orthoiihiw- 
phate.H ( frmn *lp0os\oHhoff, Btraight ), tm the common pliosphates 
may, for dis^tiuetion, be termed (wbieh give, it will he reiiieni- 
bered, a yellow preeij>itaU' with silver lutnite ). Another mi 
»jf saltB shortly to he considered, tlie pyrophfmphat€>s iilm give 
n white precijntate witli silver iiitnite. To the 3<dutioii of 
metaphosphoric aeid obtained as above or by the aetimi of 
acetic acid on a metaplnjsphale, add an nq neons ^^olntion of 
white of egg; coagulation of the nllmmen enHues. Neither 
orthopho8phoric nor pyrophosptidric aeid ermguhiteff jdbumen. 
Itoil the arjye<3iii* solution of metaphoKphurie nei*l tbr wane 
time; cm te,Hting (he solntion, t!ie arid will be found to have 
iKien eonverted into orlliophofiphoric aeid :~ 

If PO, + H,0 r^ H,PO, (orthophtmphoric aeid). 

The ordinary n*edieiual phimphorie mid h mtide frmn phoH- 
phorUH and iiitrir arid, the licjnid iM'ing evaporated to n ^^yrapy 
coahiHteneo (or treated a« deseribed on [i, IMh) lo remove I he last 
traei** of nitric aeitl. It imiy eonlain jiyropliMspborie and mrl^i* 
pbfM^phorie iicidK if the temperatare employed be high tfuough to 
remove the element"* of water : — 



334 THE ACID RADICALS, 

2HJ*0^- }!,(") = II^PjO^ (j>yropho8phoric acid). 
HjPOj-HjO = HPO3 (metapho^phoric acid). 
On redilutioii the metaphofjplioriL* acid «iiily nliiwly rcAbsorb« 
wwU^r. If, there fort% ojj telling the diluted »«*i!ution iiii'tiiphiw- 
phorie acid he found to Iw }iri^ent, the stihUiou should be boiled 
until eoti version iuto cirthophos(thurie iieid is coiupli'te. 

NjTuors Acid, UNO.^. ammjtjier NrruiTt:,*<.^ — Strongly 
bent a fru^meut of potitssiuni or HtNliuni iiitnite on a |iie<,"i* of 
phitiiiuni foil; oxygen i» evolved, aod impure [>otas»iuni or 
sodium nitrate remains 

Tests, — Dissolve the n'sidue in wiiXer, add u few droj>«s of 
dilute suSphuric acid, tben some dilute 8*diition of j)otas«iura 
iodide^ luul, hist ly,t«imi6 8tii re h ruucibige ; died eei>bhie "stareh 
iodide'* is prmlumb 2III -f 2HN(>, -- 2H.^O -\- 21s^0 4- I^. 
liepeat this experiment, n^iiig |M>tjiHsinm nitnite instead of 
nitrite ; no hkie color is protlueed. To w solution (jf a nitrite 
add iioltjtiou of ferrous fiulphnte ; a l»rowo eohKratiou iB pro- 
duced. Dissolve a amall f]uantily <>f a nitrite in enncentniled 
eiulphuric aci<l, and add a lew particles of euproua oxide ; an 
intense violet purple cj^lor is produced. 

TrMfjtfur A^lfritfji in IV^iien — The libersition of iodine from potas- 
sium imlide in iieid 8<ilntion by nitrites and not by nitrates h a 
reHition of eonHiderahle value in wMrehinsj: for nitriten in ordinary 
drinkinjyr waters, the otrurrenee ofsurh Halts, except in very deep- 
seated t^jjringH Ixing held to inilieate the j»reseuce of nitrogenous 
organic matter in a state of oxidation or deaiy. Tbc sniphwric 
ac*id u»«ed in the operation mut^t be pure, and the jiotasHium iodide 
free from iodate, Jf much organic matter is present, however, 
the nitric acid liherated hy tbe Bulpburic add nmy be reduced 
to nitrous acid. Jt is perhaps lx*st, therefore, to add acetic acid, 
and di;^til over 10 or 20 percent, of the water, ami apply the te*t 
t<* thif* distillate ( Frei^enius). Yi'ty dilute sfdutionrt of njtrtms acid 
may thus be distilled wi!h<nit the j^light^est decomposition, 

Sodh/m Mfnfe, NaND^ (Si,<Jii NitrtM, V. 8, P, ). This salt 
yields ruddy nitrous fumes on the additif»n of Hulphurie arid. 
When diaMolved in water and tested in a nitrometer, with pot^ia- 
»ium iodide and dilute sul|duinc aeid, it should lilw^rate a <]uan- 
tity of nitric oxide, eorresp«mding to not lei« than 1+0 j>er<*ent, i»f 
Iridium nitrite, 

Ofhrr mtrntcM used in medicine are nitrites of organic rsdicala. 
Ethyl nitrite, CJIj^NOj, or nitrons ether, is the most iin|>f»rtant 
constiltient af Sftiriftm .f^hrrin Xifroin, V, 8, P» Attiyl nitrite, 
Cj H,^N(),„ is al^o official iAm*jfi^ Mtri^, V. 8, P.). 

Ammonium nilrite, on being heated, yieldn^ pure nitrpg^ii : — 



PHOSPHOROUS ACID, 335 

Jhifrminaiion *>/ nitrous acid in commermal mlphuric acid 
(Luiigt^ iiticl Swoft^'s tnetlmdi. I Cc, of GriiWa reagent is put 
into each <»f a p:ur of Nti^^leriKing tubers luid mixed with 40 Cc. 
(if water anil 5 grammes of sudium acetate* Ta the cotitentM of 
the firMt tube 1 I'c, f>f the wu^peeted acid in licided, and to the 
other, without dela)% 1 Cc. of a staiidard nitrite solution prepared 
by diswiihing l>J>4i^3 g^ramme of pure widiuni nitrite in 100 (V. of 
water and diluting 10 Ce. of thiw to 100 Ce. with pure sui^ihuric 
aeid. The reddij^h colors uiay be c*>mpured after any convenient 
time, but it in best to wait five minuter. trricKs' t^ reagent may be 
prei>ared tin follows: — 0.1 g^ramme cd' white n-ioytbtliylaadne i»* 
bjiled for fifteen mill ute» with 100 Ce. of water and mixed with 
5 Ce. of gltt*'iai acetic acid. The f^ilution in then mixed with I 
gramme of Hulphaidlic acid di!*Kidvt^ in 100 Ce. of water, and the 
mixture preiHTved in a w*dl-corked bottle. If it should become 
t<H> red, it may be decf>loriztH| by whakiug it with zinc du.Ht, 

Xofe,^ii'Naphfh(jhufiiiit\ C.^,lI,NHj, is obtjiinetl when fi-naph- 
thol IB heated for &c»mc time eUhcr with saturated af]actiu:< amaio- 
nirt, or with ammonium chloride and eauKtie alkali under pretssure, 
<»r by the reduction of nitro-naphtluilene. Sf/fphfjnifie *i(id^ 
C^H.^ SOjH.NIIj, is prepared by heating a mixture of aniline aud 
gulpliuric aeid containing Home pyrosulphuric acid to a tempera- 
ture of 180° C, f(*r several hourss, and pouring into water, when 
the aeid is precipitated in a erytitsillinc form. 

OpjiELtc Acid, Cj^Hj,/),^,,— This iis one of the priueiple^to 
which the herb Sivertta ehira^Hn, or (liiretla ( (Itirata^ 
U, K» P.), owes it-8 bitterness. It ia an aniorpbouK yelhnv 
Hul^sftiUK^. Another 18 Chtratht^ C'^H^^O^^, deeouiposable l»y 
hydrf>ehh)rie acid into Chiratogeninf C,j,H^^O^, atid ophelic 
arid (Hohn). 

P H t ►R j» f 1 1 1 R< ) r H At I T>j H , POj, or H J P 11 O^ . — A .*a«l u ti on eon- 
iaining this acid in small quflntity eoubl be obtained by 
|>erniittiiig t lie heavy white fumes whkd] fall from a .stic*k of 
nioint phosphoriiHi oti ex|>i>sure to the air to dis^solvo in some 
water |>laced at the bottom of a wide-nwuthed bottle. Or 
phosphorous oxide, P^O^, may first he obtained by gently 
heating phtMphoruj* in a tube, through wldeh a slow current 
of nir is* drawn, eondeusing the fuuieg in a U4ube surrounded 
bv a freezing ndxture, and then deeonipJ8ing the oxide by 
the action of water :—P/\ -| GH^ 4HJH\ Or chlor- 
ine is paired through phosphorus melted under water : — 
PCI, 4- 'WO :=. Hj"'< ), f :UI( 1. Having culle^^ted some 
phonphorfHis aei<K a|i|dy the various tests already alluded to 
under HtjjHtphot^phnronfi Arid, first carefully neutralizing the 
phoHphorouA acid with ti aiustic alkali. 



J 



336 THE ACW RADICALS. 

The stiluhle phosphites are prcptired hy iieutraiizing phos- 
phorous acid with the appropriate alkalies, and the insolyhle 
phosphites by diHihle cleeoni|n)sitioii- 

Awsiicjated with phoj^phnroiis acid prepared as ahove Btiitcd 
there is 8iiid tu he nn aeid uf the formula H^PO^ termed hypopkm- 
phoric ncifi. 

Pvroi;alli(^ a* id. — See Tannic Acid* 

PYiioi»nt»spriORir Arii», H^1\,0,. and otrer PYRornoft- 
ruATRs. — Heat onhnary RKlitjm phiK'^phiile^ Ka^HPO^. 
12I1,(), ill II erueihle; water i>f*erystalli>'^itiini is first t*volved» 
and aiihydrcuis jdmt^pfiate, NaJilH)^, remains. Further heat 
to reiliieiSH ; water is a^ain t'vnl%^ed nml a new salt !» obtained: 
— 2NaJIPO; - HJ) t- Na^Pp,. The latter is termed 
Hodiurn pyrophosphate, in allusion lo it« origiti (jtu^^ pur, 
fire). From itM sohition in water it !ia*y lie td)taitieil m 
prismatic crystals, NaJ*.jO^, lOH/J. PhtxHphorie acid itiJclf 
is similarly affected hy heut, yielding pyroplumphoric add : — 
^H^PO^ - H^O i H^PjO^, though laetaphoHphorie acid is 
also fonned. Other pyrophosphates are produced f^imilarly* 
or by double decompt>sitiou and precipitation, or by ueutralix- 
ing pyrojdiosphonc acid with an oxide, hydro ?cide, or enrbon- 
ate. Fern Ptfrophosiph(U Stjhibi/is, nnd Sodii Pi^ropho^phaJi^ 
Na,P,0,, lOil^O, are official. 

Tests. — To a stjlution of a pyro[diosphate add solution of 
silver nitrate ; a dense white precipitate of jailver (»yrophoft- 
l>hate» AgJM),, i.s prtKhiced, differing much in ap|)earanee 
imni the white gelatinous silver meta|)hosphaie or tlie yellow 
orthophoH[jluite, To pyrophosphorie acid, or to a pyro|>ht*s- 
phate mixed with acetic acid, add an arpieous solution of 
alhumen (white of egg) ; no preei|>itAte is formed. MeUipbos- 
phoric acid, it W'ill be remembered, gives a white preeipitute 
with alhumcu. Both pyro- and meta- phosphoric aeulB give 
precipitates on adding Tincture uf Ferric Chloride, 

kvnm OF riioBi'HORLTa 

The following acids of pho*iphoru8 have now been 
destTilHMl : — 

()rtbophi*s|jhoric acid, H,PO, 
Pyro]>ht»»|>boric acid, H^P,0^ 
Metaphosphorie acid. HP(>, 
Phi»sphorous acid,^ H^PO 
Hy^Kj phosphorous acid, H^PO, 



SILICATES. 337 

Tbe throe pbosphoric acids (ortbu-, pyro-, and mt^ta-) eorre- 
Bpomi in the higher nxiile at phmphmns^ ^V *5i while jihofiphor- 
oiis licM eorre<sjK)ndH to the lowor oxitU*, F/^^* Pyropho^^phoric 
nml im*tjiph()yph(irii" acids may he Dbtmiicd from thv *«rdirniry or 
orthi»[>bof<phori*' acid by the removal of vvntfn liypr»[*hort[ihor(ms 
aeid t^)rre.Hpt)nd.s to a Btill lower (hypotbetiad) oxide of phos- 
phoru^^ than V^^\* Although three hydr4>gen titt>nis art^ repre- 
i*i'nti'd in the formtdit^ <>f both iibossphorouH and liypo(>ho,spliorou>4 
acid^, tbe aeidi* behave m dibasic and oa monobasie respectively. 



QUESTIONS AND EXERCISES, 
Wliafc aTC the sources of lailie aeid '.'— liuw ih lactic acid nsuaJly pre- 
pared ?^Njiiioe stmie of the plaiit-^ in vshieli nrnlie acid is found, — Wheoee 
is mreotiic acid derived V—lly what i^roccss may mecnoie iicid b** isolated? 
— VVIiieh is the Ixist tent fnr the njeei>ni<' radin\l ?— Plow may meetmatea 
be dj^tingiii^hi'd frooi ihiiwyauateii!?— By what ready method may uietii- 

f>boHphoric aeid be obtaioed for ex peri mental puq>os.es? — Name the tests 
or ruetaphospbates- — How may oiela- at py^oph^^^ipbo^c a^iit hii ccm- 
vertod into orth*jpho8phoric aeid ?— Dem'ribe the prc|»aratiou of phosphor- 
oi]K aeid.— How are the pyrtfiphfwplialcfi prepared?— tiive furmulee 
ilhistratjve of me tap ho«p bates, pyn:>pbospbat*'s, orthoplnwiphates, phna- 
phites, and bj'iwphosphite:^. — Meution the tests liy wbieb nieta-, pyro-,, 
and orthoph(*sphftt*a are analytically diatiuguished.— How axtj hypo- 
phiiaphatea and phogpbltea detected 7 



BiLicir Acii>, H^SiO^. AND OTHER BiLiCATES, — Bilicates of 

varioUM kindK are among the eommoiKHt of minends. The 
variourt r/rti/j* are more or lesn impure aluminium ailieates ; the 
volcanic siiKntanee termed pumh^t-i^foa^ js a poroui* aluminium, 
AlkuU^metal, and alkaline-eartb-uielal »ilieate ; the varieties of 
fehpar a-* a nde eoutaiit aluminium and alkali-metal silicates or 
aluminium nnd alkaline-*'i)rth-metal ^^iIieateH ; memfrhaum m an 
JU'id magnesium Hilieat4> ; the ordinary ^anthttitifn are ehiedy silica ; 
tftnd.Jfinf, ^/nnrh, aifalt\ ehnietdtHtff, and f*[mf lire Bilieie anhydride 
Of jfi/im, SiO,. Tripoli pi nt'ffrr, a polisiiing [jovvder now found ii» 
many other eouiitrie» than TrijMdi, ami ronsij^ting of infumirial 
Hkoletons^ in nearly f*ure Hiliea, Btifh hrirt in i\ Kilieo-erdrsm'onH 
de|>oHit found in the eMuary at Bridgwater, England, and olher 
place**. 7\mntmHttfn^ plat^ji^ of vvlneb, lUt parallel to the axis of 
II eryiftid, are UMe<l an polari/em oranalyssers in mien^wojiy, are all 
aluminium Hilieafjes with varying proporticrtiM of iron, copper, 
tUiingaoeHe, i»r other »ilicat(*H. Af^bfi^fm ur nminnfh is a fd)rous 
laik'imn and magnesium Kilieate, the length of the libres varying 
fn>m le?4« than one irnh to live feet. A single t<ilk-like fdire ean 
f*Hi«ily be fitsecl, but even in very small rna«M<^'«, aHl>estoH m infusible 
in the Ilunst^n llame, and is incombustible. It is also a lia<l con- 
ductor of heat. It ia largely used in packing piston roth and 



J 



[ 




338 THE ACID RADICALS, 

joints, and for steam apparatus generally j as a covering for boilers 
in prevent loss of beitt by radiation \ and for so lining ceilings, 
fl*x)rs, and other partitions a^ to rencier roonii*, etc., fireprooC 
Artificial acid insoluble siliciitesare fiiiuiliar in the fonn of (7^*/4t» 
and tarthemrarr. C'cimmon window-glaKS (crown glaBs) in usually 
CJilcium, atrtlium, and aluniiniuui silicate ; FVt^nch glw^^ calcium 
and iwHliuni silicate ; HohcuHiUi ghi-s^i, chiefly potassium and 
calcium silicate ; Hint or cry.stal-gla**.s for onmiiuntal, table, and 
optical purposes, is* mainly jMittiiisium and lend silicate. Earthen* 
ware is uiotitly aluminium silicate Iclay), wiih more or Ic^ss of the 
ea^iily fiiMjble silicates, namely^ those of calcium, wdium, and 
potassium, and in the comnioDer forms, iron mlicjite. The 
various kinds of porcfhiu (China, Bevren, Meissen, Berlin, 
English), Wedf/wood-wnre, and ^kmf^ytrt are varieties of earthen- 
ware, Kaotiu, or China rhtf^ which is disintegrated /<^/j7i«r, is 
the clay which yields the finest transhjccut porcelain. When 
pfiwdered and freed from gritty particle* by elutriation, it is 
oflicial (Kaolmum^ V. S, P.). Vmeibks^ brhlx, luid tUes are 
made from dilfennt varieties of clay. Fireclay contains excess of 
ttiliea and very nmall proportioris of the fusible silicate^*, hence itfi 
refractory character. Minhtr, if old, contains a little calcium 
silicate, hut it^ binding action is ihw to the mil slaked lime 
penetratitig the minute cavities on the surfaces of adjacent bricks 
and stones, and then becoming converted iutr> an interlacing or 
*' keying*' mass of hard particles of calcium carl>onate. The 
admixed siind which mortar contains, rendens the mass porous and 
so far promotes ab^forption of carbonic anhydride from the atmos- 
phere, but itrt proportion should not much exceed two meiiisures 
to one measure of Hme, or, by weight, three of wind to one of 
good lime. Port/ami, Bfmmtt^ an<i other **hydraulic** c<^«.mf« are 
calcium silicates with more or less aluminium silicate. FttUti/^B 
earth {/tfl/onei^^ cleansers of cloth) is chiefly silica, but contains 
combined calcium, magnesium, aluminium, and ir*jn, with a 
small quantity of jiotassium. Like the AralVs f/of^ another earth 
contidning gelatinoua silica, Fuller's earth is a {mwerful absorlxnit 
of oils and fata. 

Experiment* — Mix a few grains of powdere*! flhit or saml 
witb about five or six time.* its wei;trbt of &<Kliiim carbonate 
and an ecjual quantity of potassium earboimte, and fuse a 
little of the mixture on plarinum foil in the bUm-pi|>e flame; 
the product ia a *4oluble alkali-metal j*ilieate, a Aafahlr gins^or 
xmter glam. Boil the foil iii water, for a few nuoutes* ; filter ; 
to a portion of the filtrate add excess of bvilnichloric acitl, 
evaporate the sfsolution to dryness, an«l again boii the residue 
in dilute acid ; silicon oxitle, silicic anhydride, or 4n7ica, SiO^ 
remains t^ a light, flaky, insoluble fiowder. 



SILICA TES, 339 

The loregoing operation €<^>nstituterf Ibe tent for silieatea. By 
fuiion with alkali the silitate is flectinqMi&tnj^ .iiid a i^iluble alkali- 
metiil silicate ibrnied. On addition of aci<J, .silicic acid, H^SiO^, 
ii* ftet fret% but remains dissolved it' thi/ solution is ii*it Um eonet-n- 
trated* The liwit sulistHjiiently applied eliminate** wtiler jind con- 
vorti* the nilieir ai*id into Kilica, ^iO,, which is im«>luble in water 
or hydrooliluric atiiL 

The nolublf f/[ivtti^ wntrr ijlnnn^ or *jtam ih/uor of tratle may he 
prepareil by Inston, ju* aliovt: ; or by iMiiling n[* infnsunal earth 
with nohttion <»f Hodiuin hydroxirle in rloned veaweLs nnder a pres- 
aure of 7 or 8 atniosphi^re^ (tiie proportions of a<idium hydroxide, 
ailicu, and water in the latter cHse tieing about 1, 2^ «nd 5 re8i>eet^ 
ively). 

By the addition of hydroehlorie aeid to Afdulde ghi^w, and the 
removal of the ri*sultinij iilktili-njetal ehloride and excess of hydro- 
clihirie acid by dialysin (a priMH*M.s in be subiHMpiently dcseribiKl), a 
pure ar[aeoui4 sohition of aiJieic acid may he obtaim/d ; it n'mlily 
chiing<.^s int«> a gelatinona niasM of silicic acid. Po^wibly tiorne of 
the natural crj'stiillized varieties of nilicA may have \\evu obtaincHl 
from the silicic Jicid contained in such an Jiqueoiit* solution, nearly 
aU natimil waters yielding a s^mall (juimtity of ailica when evapo- 
rated to dryneHH with hyilroehloric acid. 

A varitiij of xiUfir nrut^ Hj8i<).i, sinnetime** termed dihfwic to 
distinguii*h it from the ffimbimc acid^ fl^SiO^ result** when the 
i)queoU8 solution of the latter i» eva[M>rated in tmc^w. Various 
lintural silicates corresj>ond to this ucid. 

^licotk hydtidi\ or xtfiriurrffrtUii/tft'Of^rfi^ t^iH^^ i« a spontaneously 
inflammable ga^ fornn^l on treatijig nutgnesium silicide with hydro- 
chloric acid. It in the anulogue of marsh gius or methtine^ Clf ,. 
A liquid silicon chlc^ride, HiCI , analogous to carbon letrachhiride, 
OCl^, and a gaHc^ms fltioride, 4S1F4 are alw* known. The latter is 
formeH when suli>huric acid act** on a mixture of a Huoride with 
«ilica or a siliciite, U int(?racLs with water with the (>rodnction of 
idlieic and lltiosilicic aeidfl (wf p. 32^). A carlinm silicide, C8i, 
known !is Cfirhfirtitiflttni^ In formed when carbon and aiJicon are 
heated together in an electrir furnace. 

Many other analogicrt arc traceable between the element* silicnn 
and carlicm, (.specially among their <jrgHnic compounds, 

8iT(*riNic Acid, HXYH (l^. — Amber OSwremMwi) isa reain usually 
CKTUrring in a^isixriation with coal and lignite. Frr>m the tVict that 
fragments of coniferous fruit are frequently found in amber, and 
Imprejwions of Iwirk on it>H surface, it is cons ide red to have been 
an exudation from a spetdeaof Pintt^ now probably extinct. Heated 
in a retort^ amber vieldB, first, a t^au aqueous liquid containing 
iu*etie acid and mtt^finir nM : si'condly, a volatile liquid known hj* 
oil of umbfT, reHcmbliiig the oil yielde<l by nM»st resinous snbstam'es 
under ftitnUar circumstanceH ; and» thirdly, a pitchy residue .nllied 
to aiiphalt. The i^uccinic acid ia a normal ctmstttuent of the am bcr, 



r 




340 THE ACID EADICAL& 

the acetic acM is pmduced during diatillation. Succinic acid has 
also been Ibiiiid in woniiwood, in st^vera! ]>ine-re8ins» and in ccrUiin 
animal fluids, such i** ilut^^ of iiyilatid cysU and hydrocele. It is 
a product nr the vital activity of variimB uucTO-organisms^, and c^in 
be formed by these froai carbohydrates, from siubhtaJices allied to 
earb*»hydraleH, aad from albumin. U may be (ditained arLihciftlly 
frujn bulyne or stearic acid by oxidation ; aiid from tartaric and 
malic aciils by reduetion. 

B<jtb u<>rmal mid acid succinates, R'^tC^H.O^ and R'HC^H^O,^ are 
kuiiwn. A potiiiwium hydrogen succinate, KHC^Ii^O^, H^t^H^O^, 
l\./^f anidogitUi* k> salt of Horrel, almi cxisbs. Soluble vSiiceinateJi 
give a bulky brown preeijiitate with neutnil ferric chlorine (s^ome- 
wbat le.sH vohnninou,s than feiiie iH-nxoate) ; a white* precipitiite 
witlj lead acetate, soluble in excess of either reagent ; with silver 
nitrate a white precipititk^ aller a tiuie ; willi barium chloride no 
J > reei pi t ate a t ti rst , h u t a w li i te p ree i p i tale o f ha r i n m «uc ci n ate on 
the addition of auinionia and alcohol. t<ueeinatei* are di^in^uiahed 
fmui benzoateti by the las^i named reaction, and not by yielding a 
precipitate on tlic addition of acid.n t/er p, 828). 

TA.VNIC Acrt), Gallotanmc A<:jd, or Tannin. DignUie 
ueld^ *-'iiJ^io*V -^'^2*'' — Th'u in a very couiniciU astringent constit- 
uent of idantH, but iiicoiitaine<l in larf^est ijUiuitity in galls (excn^- 
cenees on the oak, formed l»y thepniieUireand dept>i!iitedova of an 
itii^'ct)* English gallw contain frfim 14 lo 2H percent, and Aleppo 
galls {Galla, V. S. P.) 25 to (35 percent, of tiinnic acid {Acidum 
Trntfunim, U. S. P.). 

Mtjrobafmt^, the dried inimatUR> friuts of Temiinalia Cfidmta^ 
the *'diebulic mymbalaiiH" of cornmeree, miiy l>e u»e<1 in India 
and the Eantern Colonic?* iiiBt^'ad of galls. The beat contain abtiut 
80 percent, of tannin. 

Gallotannic acid. ..C,H,(OH),C0.0.aH,(0H),C00H 

Gallic acid (p. 348).„C.H,(OH),COOH 

Preparation. — Exjx>se powdered ^alla (alxmt an ounce m 
BUfticieot for the experiment') to a damp ahuos^phere for two 
or thrw ihtys and atVrward add j^uflieieut ether lo tbnn a 
&if\ paste. T>et this *:ta«d in a well-elo8e<l vessel for twenty- 
f^utr honr!^» then Imving tjuiekly en%^elo]>ed it in a linen cloth, 
fiu limit it to !!*trotig prt^sstire, so a>* to iie|wi rate the liquid [Kjrtion 
wliicb contiiin^ the Imlk of the tannic acid in i^idntion. Re<hiee 
the pre**sK*d cake to [>owder, mix it with surtieient ether (to 
which one-^ixteeuth of it.*^ bulk of water has been added) to 
form again a wdt paste, aiul prei« this as liefore. Mix the 
expreesexl liquid^^ and exiMJsse the mixture first to spontaneous 
eva|K)rati(ai and next to ;^entle beat uutil it has a«xiuirc»<l the 
conslstjent^e of a soft extract ; then place it on earthen plates or 



liii^Mi 



TANNATES. 341 

dishes, ami dry it in a lioUair eliamber at a tenipemtiire not 
exeeetiiug 212" F. (100"* (\\ 

The resulting tiuiiiie acid is a light hrowriish [Kuvdcr t'cju- 
Slitting of thin gli^teiiiiig st'alei*, with a (.■haraderii^lir mlor, a 
strongly iii^tringent taste, and an acid reaction; readily Milulile 
in water, and alcohol (90 [jt^rcentj, very sparingly sulidile in 
pnre ether though sHduble in the ethereal tluid titled in the 
foregoing prwesrt (a mixture of ether, water, and aleohol — 
the latter contained m impurity in the ether. ) 

The official preparations of taniiieacid are (rliffjf'rifitm Acidl 
Tanniri, Vfitjumittm Aeidi Ttiiiniei^ mtd Trttrhi^ri Aridi 
Tanniei, Tainiic Aeid Te^t Solution e(»niain>* 1 [mrt of Tan- 
nic acifi ill 1 part of alcohol and fciufiicieiit water to measure 
10 pirts. 

Reaetions of Tannic Acid, 

L To an aqueous solution of tannic aeid add aqueous solu- 
tion of gelatin ; a yellowiKli- white flocculeut coin|>ound of the 
two Hulititutices* is precijjitated. 

The aliove rejwrtion alHo werven lo explain thccheaiical principle 
involved in tannimj — the ctptTatifUi ol" i (inverting skin into leather. 
In t!»i« prfM'e!<?4 the skin is snaked in inriiHiuii uf oiik-imrk, the Isiii- 
iiic ackl (jf whirli, nnitiji^^ with tin- gi biliiions lissat^ of the skin, 
yieldn a eojjiixmml vt'rv well ri'prest*nteil hy the above [>re('i]iitate* 
The nnter hnrk of the oak ci^iitains little or no tannie ncul^ aral is 
«<>fionnaly shuvi'il otf from the piece** of dark which are large 
enongh t4» hamlle ; nsele><s coloring nnitter iss. thus also rejeeted. 
nther infusintm ami extracts iM-nidcs that ol' oak-hark (chicHy rale- 
4I111, i*umach, and vtdonia) are largely usi'd hy laancrs ; if used 
a|ora«, thene act t<»o quickly, iind give a luirsh, har*J, lesM dnrahle 
letitiier The tiinnic acid of thej^e jm^parations is slightly ditlerent 
from that of oak -bark. 

2, To an aqueous solution of tannic acid adil a neutral ind 11- 
tion of a ferric wdt ; ihirk IduiMh-hlack ferric tatnniteij? slowly 
precipitates] . Thi^ is an excellent te*4t f<ir the [irei^nce of 
taunic acid in vegetable infusions. The prei*ipitate is the 
hiiais of nearly all hlaek ipritintj-ink. Ferrous m\t» give at 
firsrt only a slight reaction with Umnic acid ; hut the liquid 
gradually darkens : chiinicterH written with a liquid of this 
kind, of |)roj>er strength, la'comc i|niie black in a few hours, 
and are very permanent. 



[ 




342 THE ACID RADICALS. 

3. To au a<|yeous solutiiMi of tannic ucid add gtjlution of 
tartar*ejnetie ; antimouy tauoate Is precipitated. This reiictioD 
iukI that with gelatin are useful m tlie quantitative deternuDa- 
tiu[i of taiuiic acid in various 8U l)stan<^e^, the separation of the 
gelatin taniiate being much promoted hy previously adding 
some Ut^4ivy neutral |Ki\vtler, t*ueli aa hanyin sulphate, and 
well stirrltig while adding the gelatim 

Tiie vtirit'ly of tminic jitiil whit-li occurs in oak-btirk i>< sjiid to 
hv a glue*)>*ide; that ii*, like nutny (itht r f^ulij«tiince?i, it yielUw glu- 
coHv f grit [le-t^ii gar) when boiled with dilute s^iilithurie or hydro- 
chlorie acu'd, the other pHnluet W^mg galhc aeicL 

Gambir U. H. P,, mi extract of ouroujHtrui Oambir ; as well as 
the Inie (i\t lilaek ) Catrrhft^ fhitf^h, or Trrra Japouicn, an extrjiet 
from Acfwki Ciiftrhti anii A. Stinmh; the oriiriaal Afriean (triind>i»n) 
Riuo, teniied hy the Man dingo nativert A>//io, fr«iiji ItrmearpUM 
er'mactm, hut not now in Limnaeive; Eiut htdinn Kino {Kimt^ 
U. 8. P.), frnni the PterorarpuA mari^fiithtm ; alsii Bemjai or Hatea 
Kino, from the Paian or iJhtfi' tree, Buiea fromkt«iA,' Botany Bay 
or Aui^tralinn Kinon iroai viirlous Hpeeiej* of Eumljfptu^ or Blue 
Gum trecH and mnw other vegetable j>roduetj4 — contain a variety 
(if tannic aeid {mhtuiiantiie dehi), wliieh ^Iven ji |;reeai»h precipi- 
tate with nentral wdatioHH of ferric KalU*. Aeeording to Paul and 
KingKett tliiw aeid yields, when de<M>iiipose<l, unfenaent;d>!e irtigar, 
and an aeid ditferent frfjni ordinary gallic acid, C'ateebu ami 
(ianjbier aKH<i eontahi rntfrhuir arid or m/rehiit, ^\,H^O^, a eiini- 
pound wcurring iu ininnte eolnrlcj^ aciculnr cryKtjih^ and, like 
niimf»tiimnc acid, atl'ordiiig a grc*en precijdtate with ferric sal li*. 

The rind nf Ihe fniit fjf the jmmnffaimtr {Ptinif^t iframttttm) 
(Grtmafu/n^ U. S. P.) cont'iinr* tannic acid. The a>»tringency <fif 
Pomegrauiite-rfiol Bark ih due to a iannie acid (it"* nnthelminlie 
f>ropertie*^ pnilwddy to a re?«iiMiid matter, or |>o«>«rhly In what 
Tanret HUit**?* t<i be a liquid alkaloid). A tannic* acid Jil*> ^jfoIk 
abiy given ihe astringency to logwood {H*tmaffutjfan U, S. P.). 
Rh*jUfini/-rtmi Bark {Krnmeria^ U. 8. P.) t r>ntainf* nbnni 20 perivnt 
ii\ tannie aeid, its itctive ajatringent principJe; rhubarh-rool about 
\) l^icrceot. Brarhcrnj leave?* \lhir Ur^t^ IT, 8, 1\) owe n»o»^t of 
their therafx^utie power to about 85 percent, of tannic acid. (The 
cauHe of their inttuencjc^ on the kidneys in not yet tnieed,) They 
al-so contain iirbnfin^ a crystalline glucoMde. Lfireh BitrJt, tho 
inner bark of Pinwi Larix or Lnrix Europrrn, cf^ntainK, uccording 
to StenhouMe, a considerable amount of n tannic inid giving olivt»- 
green precipitates with ferric nalt^, and hrixin and larixinir #wu/, 
Cj^Hj^O^, a scunewhttt hitter *JubHtiinee. Areea nuh or Bfiff nui*^ 
from the Ariv^i Palm U-lcrfvi Oi//W*t/), iR'Kjdi'i^ the alkaloid artkane 
(Bomhelon), contain a very active alkahiid, artro/inf, C^H, NO, 
(Jabns), Hind to be the vermifugal principle; artcaine^ an inert 



TANNA TES. 343 

alkaloid (Jahti^)^ iiiitl at'cording U\ Fliickiger tual lluulmry. alwjut 
l*i [K'trcMt. itf *'l!iiJiiic iiiatur." //r/<7 iKulsn tht- iiiiiiR' given U) 
the Itiivt's t^f /*/)>^T ftdit\ It oontairin vulsilile uIIh (Ktuipj, tme 
tHtiirtlitUfiit iif whii'li, tkaiHcol (Eykuiaii), ii[>tM.^urH io be duirarter- 
ii^tif, A mixture t(i the ntiU* arid Inives with a little lime, knowu- 
sliMTtly, iw **Betel/' in univer.Hjilly u^ed iisa .stiniiiljitingiuul exhihi- 
rutingnuiMtit'iitiiry hy the natives iii the Eaht^ irieetiug, upj»!ireiitly, 
s^ciiiir widespread phyHi<>lo^ieiil demand. The leave.^ of i'au (11 iiid.) 
are al^sci used io vnrinus other wayw ils a t^Hiimuii housidiold drug. 
The extract ot' the Iruit of Uab (jr Dimpyrm nftiin/opfrn'jt is a power- 
ful ai*tritigent Lfaitiiiriiu^ tiundc acid. The rhi/.ome ni' (in-amum 
ttifU'u/filtit/t^ tSpoftf'd Cninf^itii/t nr Alum-rfmf, utid the lejive*s iitid 
.Ht4dkH <it" Summ\ SnMnefi or tShumaciRhntt, variouw !^[>ecie<s) ooHtiiin 
liuth tannic anrl ^'allie acids. The fruit of HUinach {Rhtt^ glabra^ 
IJ, 8. P.) eoutaiiiji tannic and malic acids, Pmmn Jtu/ or Po'mm 
Ofik contains poisMnnujs toxicodeiidne acid es^pecially in siiriiig* 
Tlic prineiiial conntituent of the rni it-bar k nf hhjh blmkht^rrij 
{RiilntA^ U.S. P.) is tannie acicL A^^oHfr (hriejj Acacia liark or 
jBabool, resembles oak-bark in ermlaining tannic acid. 

Gallic Acid, C,H/) 11,0 (p. 340) (Acidum Gamnivi, 
U. B. P-), cM?cur8 iiii^rnall (jimiitity iu oak-tjraJLs and <vther vege- 
table substances, but is alwuvn |»re[iured from tiinnic acid* 
ijullic neid forms slender acicular, fawii-eolored crystal**, solu- 
ble in 100 partB of cold or 3 of boiling water, freely soluble 
in ah'ifboL sparingly in ether, 

Ii(»il one part of cfiarsely [>owdt*reil gall^ with four fluid pnrts 
of dilute >5nl]diurieacifi for half an hour; strain through calico 
while hill; eojlect the erystaln that are de|Kisited on rixFllug, 
and purify these by treatment with aidmal t^hareoal and by 
re I »eii t e< I e ry sla 1 1 i zji t i o ik 

Tests. To iin a^jueous wdutinn of galiie arid add a neutral 
sidulioji tif a ferric jsalt ; a bluish-black [ircripitate of ferrie 
gallate is prodiieeil, similar in app^ararjce t4i ferric tannate, 
FermuB salts arc* ali*o blackened by gallic acid. To more of 
ihefNdntion add an afjueouf j^dution of gelatin; no preci|d* 
tote in formed. By the latter test gallic acid is distinguisjhed 
from tannic acid, 

Pijrmjnllic and or pftroffaiUd V. 8, P., C\H,(f>H),.— This wb* 
Htance iiublime** in light feathery crvHtals when gallic aeid is healed. 
Or it may Iw ibrmed by heating gallic acid with !i rir 4 times its 
weight of glycerin to a trifij)eralure of HNP or 2(Kr C; for a short 
limo^ until carbonic aidiyflride is u'l longer evolved. T^nper hent- 
jiig at a lower temperature is not eciually effective, and below 
100* V, probably no pyrogallol h produced (Thorpe), To an 



344 THE AVID ILiDWALS. 

atjueous dilution add a neutral solution af n ferric Haiti a red color 
m produced. To another portion add a ferrouti salt ; a deep-blue 
color rct«ult8. 

TeMiJoT the three acids^ fnnmt% gaiiict and pifrogallie^^Tn 
three separate small <|uautitit^ of milk of liuit^ iti tt^st^tube^ 
add, resj>ectivel}\ tiiunk% gallic, and pyrogallie aciils; the firnt 
slowly turns lirowu, the second uiore rapidly, while the pyro- 
gallic mixture at ouct; uj^umes a In^auhful pur]>Ut^ii-red c<>Ior 
eliaugiug to browu. Tht«e reactiuiia are characteristic ; they 
are aceompauied hy al)sorptiou of oxygeu frofu the air. 

Z!V of I^FiMjalkdhi Gnf(*atia/yifi^. — A mixture of pyro^allol aad 
Holat)oaofpota.sKiimi hydroxide abaorl>M oxygen with such rapidity 
and csottipletene^ that coaccntraled wilutiuns of each, pat*^ up 
sacsceseively by nieautt of a pipett^.^ into a graduated tube con- 
taiuing air or other gH,H, #iver iaercur\% forra an excellent means 
of determining free oxygen. The value of this method may he 
proved rontfhiy hy pouring a ?<mall quantity of each ,M>Iiilion into 
a b(»ttk% inmicdiately and finnly ch>Hin|5 its mouth with a cork, 
thornttghly whakin^^ the Iwittle, and then reinovin|jr the cork under 
wjiter: the wjiter rnshcH in and iK^uiVii^ sdiout one- fifth of the 
previous volume of air, indicating that the atmosphere con tains 
*ine-iifth of its hulk t>f oxygen. The small (]nuiitity of carlHinie 
anhydride prfm'nt in the air 18 also ahsDrbnl by the alkaline 
lifjuid; in delicate eX[(eriaKnt-s ilii?* should first he renmved by 
aieana of the caustic alkali and the pyrogallo! then be adde«l 

TlTTiM'YANTC AdD, HSC'N, AND OTIJKR ThJOCYANATE^. 

Boil (o^ether sulphur and wdiition of ]x»ta*<8iuni cyanide; i«du- 
tiori of iKita.^>(uni thimTanatc, lvSC'N» in formed. Warm the 
liquid, add hydrochloric acid until it faintly re<hleus litinuss- 
paiKT, and filter; any jwitaH'^iuiii sulphide it* thus dewmi|_»o^4Nl, 
and the solution may tlien be used for t lie following remliond. 
The salt readily crystallizes. 

Tests. — To a Rniall i>ortion of the solution add ferric chlo- 
ride ; a dt^p bhwd-red gohition cotitaining i^rrir thiiK-yanate is 
formed. (Solutions of pure ferrous salt? are nc»t eoloreil by 
thiocyanate^) To a jKirtioii of the red liquid add a little 
hytlriRddoric acid; the color is not dii*charfzed (ferric ineam* 
ate» asidt of ?4imilar tint, is deeo!orized by hydrochloric acid). 
In the acid liLpntl place a fntL'nient or two of zinc; hydrogen 
sulphide is evoh-ed, and the red color di»ap|iear»» 

To anotiier portion of the ferric thitKyanate add solution 
of mercuric chloride ; the colcir is at once diBcharged* (Ferric 



THIOCYANATES. 345 

luecouate is unaffei*t€Hl l>y inereiirio cliloride.) The resictiou 
witli tVrrit^ suits is tlie l>t!i*t te.sl for the pressure of a thio- 
tyanato; atid indirectly is iil.so i\ good test tbr the presence of 
hylnjcyauie acid or other cyanide {j^ee |>. 2(i9j. Ked ferric 
acetate solution Is tlecoinpo^cd by el m Hit ion » Keither the 
ferrie acetate nor the i»eeonule yiehls its eohir to ether ; but, 
on vshakitig ferrie tbioeyanate s<diition with ether, the latter 
tnices up the thifMTUuate and lieeonien of a |iurple color. 

To a Boiution of a thioeyanate add atdyiioii of merenric 
nitrate; mercuric thioeyanate is precipitated as a while 
powder. 

Pharanh'^n SerptnU. — ^Mercuric thiocyanftte, thoroughly washed 
anil made up into little cone**, forma the toy termed Phanudi*8 
^rpent. It readily hunin when iij^nitt'd, the ehief |»nKlui'l being 
a light solid matter (melna^ C^H^N^, and jiiehim, f '^H„N,|), whieji 
ixHUet* from the cone in a simke-like coil of extraurdiaiiry length. 
The t>ther produetn are mercarie *<ulphi<le (uf which purt remains 
in the rciiidue and part in vr^latili/AHl), nitrogen, Kulidmnms anhy- 
dride^ eiirbonie anhydride, itnd viipor uf iiietidlie iiiiTenry. 

The thioeyanic radieal (SON) is terined thinivanfigen. The 
thioeyanatcs were formerly culleil milphm^yiUiidr*, Halivm LnnttunH 
ihiocyamiteii, 

Deic Acun, C^HjNPg, ami otiii^k Ubatks. — Acidnhite 
a Few ounces of iHiman urine with hydrrM'blorie acid and set 
asi^k* for twenty dour hours ; a W-vi iidiiute erysla !s of urie acid 
will l>e fotniil adhering to the siiles ami bottom of the vessel 
and rtoating oii tlie surface <d" the li*[ui«L 

BCicroscopical Test, — Pluei! mmv of the floating particles on 
a .^lip of glass, and extinune thein under a [Kiwerful k'us or a 
niicroseojje ; the chief ]Kirtion will be lound in the form of 
more or less square, yellowishp Ht^mi-transparenL crystals, two 
of the sides of which are even, ami two very jagged ; but iilher 
forms are common. 

Chemical Teat, — Collect more of the depfwit, place in i\ 
wateli-glass or small white eva|K>rafing-dish, remove adherent 
moisture by nieans of iilter-pa|K-r, in Id a drop or two of con- 
ceiitrateii tiitric acid, and eva|sirate to dryness % the residtie 
will 1)6 re<L When the disli is ndd, n<hl a drop of ammonia 
wnter : a purplish<'rimsou ctdor results. The color is deejii'ued 
ou the addition of a drop cif 8<dutiotiof potassium hydroxide. 

Notn, — Uric acid (or litlnc aciil) and sfMliuai, potaiwinni, cal- 
cium, and aniaiijaium urates (f»r lithali's) arerommon lonstituerits 



346 



TUE AVID UADWALS. 



of animal excretions. Hmnaii urine ftinUiinft iibiuit oni* part nf 
urate (usually HOtliiini urati) in lUOU, When uiore tbau this 
i» present, tiie urate is utk-u de|«MsilrJiiiia w^iiuient in tbeexLTeteU 
urine, citlier ftt onee, 4ir afU'r sUintJiiig a short time. Uric acid 
or other uratti it* ali^tj oceasidnally depv^sited lielore leJiving Iht? 
bladder, and^ nlowiy aeeuinuhiting ttuTe, loruiw a cfHnnnin variety 
of urinary eakulus.— Some yrate,s are imt definitely crysstalline ; 
butj when treated witli dihite nitrie aeid or a dni|i uf mlutiun rjf 
poti^LHwiuia liydruxide anil then a dropdr two of acetic aeid, mierti- 
8i-oi*ic cryKlals of uric iicid are usually formed. — All urates yield 
the rriinwin enlrpr wlit'ii treated ai* ahove de.M-rilwd. Thii* etdor is* 
due to a deiinite Huhstance, ftttiirjuj^ ^^^f^^^V (^^''f*^" murer, a 
fiheU-fish of «iaiihir tint, troni which the iUHtent and highly valued 
purjde dye seeniH t<» have been prepared }, and the test it* icnown 
as the murfxid te^t. Tlie iorniation of murt'xid m due t^i the 
aetion ot' amnmniii an nilojuh, tJ^UjXj )^y 4H/J, and other white 
crystalline produet.s of the oxidation of uric acid by nitric acid. 
Murexid \n a gmxl dye ; it touy be prepiircd froui (/"'iw-iCtheexcn'- 
ment of fea-fowl), which contains a large (Quantity of aiiunonium 
urate. — ^The excrement of the serpent is aluiO(St pure ammonium 
urate. 

Uric acid and the urates will again lie alhicied to in contiectioo 
with the wubjt^ct uf luorlod urine, 

(hnsiiffdioft t// rne JrrV/.— The jdiy^iological and patboli>gieaI 
imijortanee of uric aciVl has obtiiined for it gretil attention from 
ehemiMla, Var aeecaints of wJuit hi»H been df>ne iji reet^nt years 
t4:»war*l elucidating itn conHtitution, *?tudent,s of organic ehcniis^tiy 
Duiy cf*nHUlt the J*ftfirmmru/ir*ti Jtmnntl^ -ird Series, yoh XIV. > 
p. 771 * vol, XV., pp. Hi* mid 411 ; and vol, xviii., p. fi9. 

VALERir A( ii» or VALERiANir Ant), IICH^O,, and 

OTHKU Valkhati;^. — In a tH=t-tyl»epbieea tew drops of amy 1 
aJfN>liol tfut*td-ojl, whieli \^ impure aniyl ah*ohol, may be iineil) 
with a little dilnle sulphuric ncid and a grain or twoof jMitti^ 
sitnn fltehroniate, tnark the tulM', K-t awide fi»r a few h4nirH, and 
then lieut tlie mixture; valeric acid of oharacteriHlic valerian- 
like oiior, i« evolve<l. 

Valerie aeid occurs in valerian-root in a»ftociation with the c<?sien- 
tinl oil from which it ih ajjparently derived (f^re p. 471), hut is 
usually pre]nired artilkially, by the foregoing process, from amyl 
ateohol, tr» which it lK.'ars the same relation that acetic add doe» 
to common alcohol : — 

C,H,OH + 20 = HC,H,0, ^ H,0 
C^H^'oH + 20 = HCH/), f Up 

Sodium Vafrrate, NaC^H^O,, is prepiireti from the val«*ne acid 
and nmyl valerate obtainedon diittilHngamtxtiuroof amyl nlcohol^ 



VALERATES, 347 

iulpburic at'iil, [>ola8sium difhromate, and water. Tho mixture 
«hoidd stand (or Hevt-nil huurs before he^ii \n uppHed. 

Amy I akr»hol Oxygen Vttlerie acils Walvr 



Amyrvaiemtc 



Amylalcuhol Oxygeo Amyfvafemtc \VAt*r 

The distillate is saturated with «»dium liydr<ixid*% wliicli nul 
oiily yields nmliuiii viilemtt; with tbo hvv vak-rir at^^id, hut als«» 
difoinpcKSi^s the ajuyl valerate produced at the Siinie time, uir»re 
Nidiuni vidrnitr heirig formed and Home aniyl alcohol net free, 
aeeunliiig ttj the fuUowing LHjuatious : — 

HC.H,0 + NaOH = NaC.H O, -h H,0 
VAleric iicld BOdlum hydroxide Sodium vtitemte Water 

C<^Ijj^^6^^0» 4- NaOH = NaC,H,(\ + C,H,OH 
Ainyi vak-mtti sodium IiydroxUle Sodium vulerate Amyt iilcutiol 

From the swdutioti of iMidiuui valerate (whieh should be umde neu- 
tral t4t test-paper by earelu! addition of »LKlium hydroxide solution) 
tlie Sfdid white Hiilt in olitaiined hy eva|M»ralion to dryneiw and cau- 
tions fuiiion «jf the residue. The uia.^ obtained on ecH^Iiri|!: should 
be broken iij> and kejit in a well-closeil bottle. It HbouUI Ik* e iitircdy 
f«>iubhi in alcohol. 

0/htT Vfi/rrafrjt^ ah zinc valerate, 7jn{i.\lljii.)^ (Zmci Valtrm^ 
V. H. r,)» an*l ferrie valerate, Fe(iyiy<>j)j^» nuiy be auole by the 
interaetiim of nodiuni or either valenite mm tiie sulphate or titlier 
HJilt of the nii'tal the valenite ofwliich is de:^lre<l, the new valerate 
cither prceipitatin^ or cry?^tallizin]tr out. A Imt twrhitiou of yjm" 
><ulphate (r>ij part.H) anfl siMJium valerate (*y parts) iti water (40 piirt«) 
^'^ivi«< a croji of er^stalt* of zinc \tdcriite on etM»lijig. AmmmtH 
Vitfrra*^ U. *S. P., in white himellar crystid«, re8ult« wh(*n dry 
ammonia ga.n is [«tK,setl into valeric acid. 

Tests. — Heated with ililiite sulphuric neid valemten of the 
metals give a highly characteristic aiuell (vnlerie acid), 

Kf)fr. — Of Ihc four |poKHible varietien of valerates, the foregoing 
are the ordinary or im-t'fi/rrftffA, the cunstitutional fonnula tor the 
aeid being fC'H ,), ^ CIl — (Jl, — Cimil. Sff the Aeetie H^nts 
of Aeid?* in the Sect inn on Organir nicnii?*try. 

The aniyt alcohol (t'.H,,<)iIi from which valerates* are prepared 
n»ay contain the n<'xt btwer luemher of the homologous iH'rii*H of 
aleoboln, ftuhj/ a/nthof, {\U.U\\. This /dcohoi, during the oxi- 
daticin. will In* converteil into ftfitf/Hr to iff, IK'Jl^O,, the next 
lower boujologue of valeric aeid, [Uyll^,0,, and hence the variouH 
valerak*8 may !»e con tarn inat*d l>y sonic httft/mfrji. Thew are 
det4H*led hy distiliution with dilute nulphurie aeid and addition of 



348 THE ACID MADICALS, 

HoUition of cujiric urt4:il(^ to the diKtilUitf, wliifh Vki once becomes 
turbid if butyric licid be iirescid. Iti tliis reacri^ju vjtltric ticid Miid 
iind butyric acid arc [ir<»ducc<l by interaction of tbe xidcratc and 
butyrate and the sulphuric ucid, and they dis^till over on ibc appli- 
eatjiui of heat. On the jiddilitju of cu[>ric acetiite, ^'u(l'JIj,Uj),, 
cupric l>ntyratc, ru(C|H,i J^i^^ is* foriueti, antl,, being ajuniat 
inrtolubie in water, is at once precipitated, or remain.^ HUsfietided, 
giving a bluii^h white opidcHeent Ikjuid. Cuprie valerate, 
( ■H(t -^11^05)^, [h alrto lunned after 8taite time, but in fur luiirc Huluble 
than the butyruie^ and only .slowly collect** in the form of greenish 
nily dnjps, which gradually \n\i^ into greeiiiah-blue hydrous cry»- 
tiilline cuprie videraie (Larocque and Hundt), 



QUESTIONS AND EXEKCISES, 

Mention a test for uitritea in potiibl« wiit^rs,— Which nitmtea are 
oificiftl? — Give the uamcs of soidd uatviml and HrtiGcial siliriitea. — **Whiit 
isBolable glaes"? — Distinguish i>ctweon silica and siliric acid.— How »re 
silicates detected ? — What is the <[annti vale ace of silitoii ?— Mt'ntioo the 
sources, formidtts and aaiilytical reaRaious of succinates.- State the modo 
of manafacture of and leBt.«» for thittcyaDatee. — Wliat proi>urtioii of Ijiniiic 
add is contained in galls?— Dt\s<'ribt' the procees for I he pri'jmnition of 
tantiie acid. — Explaiit thii chemistry i>f "tauning/' — Eiiiiiuersite the WMa 
fur tannic sicid. — What is tht? foraxnla for tannic acid V— Mention ofUcial 
siihstance» other than gidls wht^i jwstringfney in due to tannic acid.— 
How is ffalhcacid pruiiared? — By what reMction isKullieaeid distin^tii-'^hiNl 
from tan nil' arid ?— Mention the elmnn leristie iirojM-rti<"4 of |.yropdlt< 
acid— Explain the mnrexid tent f'lr uric acid. — Dtstriln^ the ar(il3< liI 
l>reiiarati<»n of valeric ackl and other vsilerat*^, ^ivia;; eiiniilioiKi. — ^VN Imt 
is the formula of valeric acid ?— How are butymtea detceted in pr«aeue>« 
of vakratejj? 



DETECTION OF THE ACID RADICALS OF 
SALTS HO LUliLE IN WATER. 

In exandiiing a sidt wdiihle in water» and concerning which no 
general informiition ih obtJiinaldc, se^irch tnu«t first he nuide fur 
the raetalltc ra4ical by the appropriiite inethcMl*^ (>^f pp. 3li8, S42, 
etc,). The metal having been detected, conMden\tion of the 
character nf ita suits will indicAte which acid radicnU rnny l>e, and 
wltich cjumot be, present. Tbuj*, fiir instance, if the >*ubHtjm«^ 
tinder examination is freely si^liible in water and Jcnd in found, 
only the nitric and acetic radicals nee<l be*<:)Ugbt, none other of 
the lead ^lt#i than nitrate or aeotat^* l>eing freely aolubh^ in wat^T. 
Moreover the salt is more likely to be lead acetate than nitmte, 
for two reaMaiw: the former is more soluble than tlie fatter, and 
ife»by fur theconiniotiersatt of the two. Medical and ph»inna<Tnti* 
cal students have probably, m di»penMing^ alrejidy lea rut much 



^^ 



ANALYTICAL DETECTION OF ACID RADICALS. 349 

ccmceniiiig the soluliility (if salts, niul wliothor a salt as rarely 
employed or ii^ in inmmon use* Anci although hut little deptnici* 
enceeau be jilaced ou the iluiiKea nl a salt behij^ ji resent or absent 
accorciiiig t<» its rarity, still the point nuiy have its iirtifter weight 
If, iu a mixture of salts, auiiutmiitnij potiuwimu, uiid rnagnemuni 
have Iweii fouud as^uriateii with the suljdiiirie, nitric, ami hydn>- 
chiorie rsidieals, and we are ask ml how wc siij^jiuse these t>udie8 may 
have existed in the uiixliire, we art- inn eh inure likt'ly to he eurrect 
if we suggest that sid-a(uuiouii*»% nitre, and Eiisniu widt were 
originally udxed together, than il we saii|>os<^ any other [lasj^ihle 
euuibinatiou. Sueh aj»jn%il?i to ex[x ritnee regarding the solubility 
or riirity of sidt*? cannot be rnadi' by any une uuaefiuiunted, or 
iD!*uthciently aequaintedj witb the ehuraeters of Miilti*; in sueh 
cusei* the ri*hitioii of a salt to water and aeiiLs ean be jisecrtsdiied 
by referring to the following Table Qj. 351) of the s^dubility or 
in»f^lnbility of ubout livr hundred of the eoinnion and rarer salts 
met with in ehemieal o|>erations. 

The alternative eonrse to the alwive ( namely » to ascertain whieh 
aeid radicals are prc^i^ent in a niixturr, and then in appe^il to 
experienee to tell whieh jnetallie radicals may lie and which can* 
iiot be present) in iuipractieablc; for acid radicals cannot be »i*pa- 
rated out, one after the other, from oneanti ibe siinie quantity of 
Btibntajice by a similarly simjde treatment to that already given for 
metallic rati] cals. In* leed sneb a sej>aration of acid radicals could 
ucarcely be accomplished iit all, or only by a vast lununnt of labor. 
The metallic radii-als must tberefore be detected first. 

Even wdien the metiillic radicals have lK*cn flamd, the acid radi- 
cals which may be prt%sent JnuHt be wmght for singly, the chief 
additional aid whieh can be brnught in being the action of s?ul- 
phuric acid» a barium salt, a calcium salt, silver nitrate; and ferric 
chloride on fn-jtanafr small [wrtioiis of the «olulion under examina- 
tion, RH dotitiled ill the second of the following Tables. 

Qua Htafive A jialysis. 

Before comniencinj^ the analysis of nn Jiqueoufl «olution of a 

Bait or salts, the metallic rarlical? in which are kmnvn, asi'er- 
tniii which acid radi<*als may be, or, what comes U> the mime 
tblog, whieb cannot \m prest^nt To this end, consult the 
following Table (p. 351) of the solybility of Balt^i in water. 
Ijijok for the name of the n\etnl of the salt in the vertical 
ftdiimn ; the letters 8 and I in<licale which salts are s<dnlde 
and which insoluble in water, an asterisk uttaelied to the 8 
meaning that the salt is sb'gbtly s^dnble. 

8ome of the sjdti^ marked as iuNihdde in water are wlable in 
aqueotiB Bolution* of ftoluble salte, a few Ibraiing soluble double 



360 THE ACID RADICALS, 

BaJts, To characterise salts a« soluble, slightly Holuble, or iusolu- 
bk% rmly roughly indiejites their rehitiim to wnter : nu the one 
haiid^ very fewnalU jireabj^ohtUdy iii^jlulilein wat*^r; on the other, 
there h a limit to the Holuhility of every salt. 

If onltf otu\ two, or perhdjkH three (firen arid radicafM ran be 
pr€>!e)it ift the Hoiitthn^ teat dlrvcfhj for it ttr them according to 
the reaciions (jive n in the prerioitn jxtgej*. If fiereral may he 
present, jxmr xmaU p&rtion^n of the sointion^ renilcred neutral 
if neeettmnf Ai/ addition of ainmonia, into five teat-fyht'f*^ and 
add reHpeetirefij inttpiiuric ociiL fHiriam nitrate or rhfonde, 
enieiom eJiJoridf\ Mirer nitrate, and feirrie chiorhie ; then eon- 
suit the Tahli' on p. Sft2, in order to interpret c&rrectly the 
effects these reaf^entn may have produced. 

Remarks on thh Table, p. 352. 

The first point of value to be noticed in confjeetion with this 
Table, in one of a negative charat'ter; namely , if either of the 
reagenti* given no reaction, it is swdf-uviikiit lliat the »,ilLs whieh it 
cleeompoBe8 with proOnetioji of a }>reeipitat4' Uiust be tihsent. Then, 
iijjiun, if the action of one ol the rejigent** ijiflifatt^ the alvsence of 
ccrt4iiri aeid raiycid?^, thone raditidn cannot be anion^ diot*e precipi* 
tilted by the other reagent; thn-^, if the action of ssnlphnric add 
points to the absence of sulphides Mulphitei*, earbunatet*, cyanides, 
and acetates, these salts may be struck imt of the other listf*, and 
the ©xamination of Hubserjuent precif>itates is »o far simjdified. 
Or, if the biirium i>reeipitate is soluble in hydrochloric acid and 
the ealcinni precijdtate in acetic acid, neither sulffhates nr>r oxa- 
lates CH Ti bt* presc^n t. ()l»ser> ing t hcsc and i >ther p« a n ts id di dercnce, 
which will be HcH»ti on careful and tlKUXfrhtfnl rellection, and 
r*'mcmt>i^ring the facts sujjgested by a knowledge of what metaHic 
radicles are jiresent, one acid radicid after another may Ik* struck 
otf as absent or p resent ^ leaving only one or two as the objects 
of special exiieriment. Amonp the chief difficulties to be encoun- 
tered will be the separation from each other of chlorides, l}ronnde:^, 
iodiili^, and cyanides, or of tartrates from citrates, and confirmatory 
tests of the presenceof certain com prjun<K These may al! l»e sur* 
numnted on referring back to the reactions of the various radi- 
cally JLS dcHcribed under their hydrogen salts, the acids. 

In rendering a s^duti^m neutral, for tlie application of the various 
g:roup-test^-*, the necessary en)f>b^yiiientof any large amount of acid 
or of alkali must W noted, the i>r^Hc*nce of alkaline hydnjxides or 
of free acids, respectively, being there! ly indicated. The j)resenee 
of free acid is usually indicated by the ahundant eli!erv«»seenec 
which result* on the addition of a carbonat^\ 

8ulphnrie acid, the first group- reagent, may itiielf yield by 
reduction, especially when heated with certain solid iubetancefi, 



QUALITATIVE ANALYSIS. 



361 







le 



BB 



11 



^^ F— u ^ p a U' 

■ g ^ s 3 3 s s 



DDaDCi>QQQOQDOQ*«CD 



QDQQ*«CDQOQDODQDV>« 



QoaQGCQoaoccasaQQoaQ^QQ 



Aeet»t«. 



o^M An«iitt«> 



rftrbontte. 



moiW^ai^m^fiZDi^m^namm^Cfuyim^mm^timmuim chloHile. 



QI^^^QQi^{j)««Q3Hi^^a3«-«aDQDQD0QaDQQ^QCI»*40QQD CltrmtO. 



QQ •i^ IH t-l QD M GO -^ l-H M OS QO 00 M •« •« QO 09 ^ IM OS •« M ^ 1-4 09 HI 



.•5 



ClironiBt«, 



CY»n*de. 



.Dg. 



Hydroxide. 



QD6DQB(X>aQiHQr3®a9MiMW0li(&iHi0DOQi-4QQOQQSO9*-4CDMOQ>« Iodide. 



QDQQQDQI!}(|3(l)ODlX}a3O3O9O9QDaD<«QDO0Q0QDO3Q!)O&ODa0*^Q0Q& Nttratft. 



MiMfHiQD<3P»-iOek-«i-ii-4iH^Mii-^i-i>«qQOQ»-4MCIQ^i-»i-^i-tC^QDi-» QxAlftte. 



QD«g. 



I Oxide. 



^^ PhoiphMA, 



a}ii-^O9O009QBO9Q0QQC3DO9O9a0M<^Q0O9QQOa<QD<XO&Q0H^lMQQ^l^ 



9 QB 09 QO QQ Q£ 



Sit]pluit«. 



Solptilda. 



flDM#>t«*QDMQDCIQQCH0-«QBO9»H>^^'<i^-iQgQD^CC^M^XlM 



f)ulpl}ite.« 



Utt{B-«CD^4QQ-^QPi^i^(BOSM'^QD09agO90&C£COi^^«-^Q90D Tftltnita. 



*4 
> 

ES 
S 

r 



Q 

QO 

r* 
H 






352 



THE ACTD RADICAIS. 




k 



QUALITATIVE ANALYSIS. 363 

snl|>imn>u?i ai id iirhyiln»p:pn niilphide (^fv- pji. 2i^H and 29())" hent« 
tht* [>rf>ducti(>ri t^f theM' In mi a dUukd wtkiti^m sliotild alnj*c be 
rc^:ard(*d liJ^ evidenre of the prest^rire nf a yulpliide i»r huI plate. 

Cakiuni chinrirle duvH not |»rtripititt<? citn*tes^ readily or cum- 
|rk'tely in the eolil: therefore the mixture shtaihi he fiUered and 
the filtrate boikd; ealeiuni citrate then separates. Caleiuai tar- 
trate is soluble in w.*liitiun oi' auninuiiuni ehhiriile when *]ujte 
freshly precipitiited, hut not after it has beeonie ery^talline. 
From their si»hititms in arnnioiiium ehloride^ ea lei urn tartrate is 
mostly preeipitated hy aainuMiiaj and ealeium ritrate mi boiling. 

The rarer aeid radieals will be very i^'ldoin met with. The 
presenee iif A€ii^'>ff/r,?, kijipHnite^ {^k\\iv\\ ^\\e beii/.oie aeid), hfj^m- 
c/iffprifrA^ th'twuifthnfrii^ tiitritr^^ and rakruffK will be indieated 
durinj; the treatment with ?*ulphiirie aeid. FtTrocf/futtdin, Jtrn- 
Cf/unf(irj<^ rnrntmtff'M, itttrru^afrM^ /hifH'^/nntjffjij fannnfeifj aud ffttfffifru 
are among the i^alt?* whone prem'me in indicated by terrie ehluridei 
format eA^ hypoph^^fphitt*^ makdcJi^ and n therms are indi edited hy silver 
uitrute, f^'mfcM ehiir when heated, giving an odor resembling 
that of burnt Jkithers. 

In aetual praetiee the analyst nearly alway-H has f^ouie eltte to 
the nature of rarer substanees plaeeii in his hand«. 

If ehromium and arnenie have been deU^eted amoni^^ the niefealliu 
nidieali^^ these eletnentj* uuiy be jirewent in the fornj of chromah's 
antf'fifi/t'jf, and arseniten^ yielding with liarium chloride yellow 
barinm ehromateand white barium arnenate and ar^enite, and with 
silver nitrate red»iIverehromate, brown silver araenate, and yellow 
silver arbcnite. 



QUESTIONS AND EXERCISES. 
In aualyzlng an a<juec»iw solatiou of Bultn, for wlijcli nuiicalH woatd yon 
first ^^a re h, tb<i mt'talJic or th<^ acid, and why?— In »ii a(|inHnm Holutinu 
Uivrt? liJkvr been fntii*d iijiMfiieHiuni (M^) aiirl |Mita}«Hiuiii iRl, with lb« 
sulfihurie riulital iSt),>,unil iiM!iiie{I>; nXwiv^ whit'li nalt^ were [iriilmbly 
di«8olvt'd origiiiully in th*' water, utid oieiitioii tli« coiit^idoriitioiis wlurii 
ifiiitlw you tu the eoiit laaiuua.— (five a Kkntt:ti of the mt Ihods by whieh 
you woutft examine a ncutrnl or only fuiutly atid aiiueoiia ht|uid for the 
lU'ltl radtcak which lui^ht liC' present. lu whiit utagesof theexartiUiation 
wuiild Ihe following aalt-fi be detcctc^d? ii. Carbocatefl and Sul|di.ttu!i, 
h. Oxalates, c. Turtrat^is and Nitrate.'*. *l Acetates and 8aJpbiti'«. 
«, Bromides and Ciy»nidofi. /, Borntos. tj. Iodide« aud Fbo<i|)lifttea. 
4, Chlorates, OxAlAtes, Hud AcetAt<vH. i. ( blurideH and lodidi'fi, }, Sul- 
phites, it. Sulphides, Carl^onates, and Nitrates, /. fitnitcs iind 8ul- 
phAtM. — Silver nitratfl If i yes uo precipitate in a ^iv*'ii iiqueiHii Rohition ; 
wbAt»cid r^ic^U mny be i»rc^«.«'iit?— Bariuui chloride givca no |jri^^ipi« 
tatis in a jjriveti nctJtnil Holutiou, but silver uitriito givos a white prt'cipb 
ti^te: what acid nulicala are iudicat«Ml ?— Ftrrif rfiloridu pnidutTs a 
deep-rrd color in u solution, calcium chloride yieldinji! no precipitate; 
what «Alt«i may Ih* presctittand how may they he diittiugoished fruui each 
other? — Ferric cldorido give* a black precipitate in a ^ijlutiou in which 
KUlphitrie acid dvvelopti no odor ; to wliat in the rffbct du« If 

23 



J 




354 



QUALITATIVE ANALYSIS, 



ANALYSIS OF SALTS. 

SINGLE OE MIXED, SOLUBLE OR INSOLUBLE. 

Thus far, Tiio*^t of the substiLiices whit'h huve Ihhti considered, 
e.speciidly thuse of f»hannnteutinil intL-rt'wl, huve In^pn regarde<l us 
dvfiniU' ctuopoujjds, and ii^^ baying certain well-drJined radicab 
tenuc'd ruetallie and acid reHjKVtively: niorLM>viT attenli*(ii biiM been 
designedly restrieted to Uk(s<? definite Ciimpuunds wiucb are 
soluble in water* But tbere still are mrnieronH ijubstunefs bavjug 
»o definite or kn<isvn e<»ai[wit«itiunj and of those* having definite 
eoni|MKsition there are many having no detinjtidy ascertained 
radicals. Again, of those baviug definite eoinjiOf<itifin, and whose 
cont^titution Il'ls been in part or entirely elueidateti, tbere are 
many inwiluble in water* 

Cheaitcal .sulistanci^ of whose fompbmtion or eoiwtitutron little 
or nothing iw at present known^ areebietly of animal and vegetidde 
origin ; tbcy are not of immediate importance, and may be omitted 
from consideration here. 

Of i^ubstances which are definite in com position, but whose 
parti« or radicals are unknown or impcrfVetly known, there are 
only a few (such a^ the alkaloids, amylareons and siieeharine 
matters, the glneosides, and the albuminoid, re?*inoid, aiid animal 
and vegetable coloring matter^*) which have any considerable 
amount of metlind or phiirmaceutical interest ; thef*<^ will be 
noticed i*ubseH|ncntly. 

Definite compounds most frequently [present tbemf^elves ; and 
of these* by Ihr the l^irger propt>rtioji (namely, the sjilt,s soluble in 
water) have already been studied. Tbere remain, however, man}- 
Halts which art' in>«dublc in wjiUt, but which must U^ brought 
into a state of solution Ik' fore they can hv effectively examint»d. 
The next sul>ject of lalioratory work iw, therefore, the analysis of 
snb-stanccH which may or may not be soluble in water. Thin will 
involve no other analytical schemes than thowt^ which have l>een 
given, and will in only one or two cjise-M increase the ififhrulty of 
the analysis of a precipitate produced by a gnrnp-reagcnl ; but it 
will give roundncHs, completeness, and a practical bearing to the 
student'!^ analytical knowledge. Such hilHiratory work will at the 
mnie time bring into notice the mctbodH by which substanewi 
insolulde in water are manipulated for pharmaceutical puri>oae«, 
or are made available for use as f(x>d lor pi ante, or as food or 
medicine for man and animals general ly» 

Preiimmary Exammaiion of Soiid (ekkfly mineral) Saiiji. 

Before attempting to di«»rdve a salt for analysis, its appej&nuiec 
anil other physical j^rojH^rtiea should lie note*!, and the influence 
of heat an<l concentrated sulphuric acid should be a»c«Ttained. 
Unless the oj^erator knows how to interpret what i» tliuf* observed, 



QUALITATIVE ANALYSIS, 355 

and Uy what extt-iit he can place confidence in his observatioii», 
he f^hfiuld omit the preliminary examination alt>ogeiherj except 
when he is ahle to fothiw it fiut iintler the {fuiihince of a judicious 
teacher; for it h iniprai ticahle here to do more tlian hint at the 
re^tuJta which may be obtaimnl hy such an examination, or hi> to 
adui>t description?* a*» to prevent a s^ludent alUjwing unnecessary 
werprht to attach to preconeeive<l ideits. 

Whatever lie the coiir^ purwued, tshort menioniiida dejscribing 
re-sulti* should mvoriabJy he; entered in the note-book. 

1, Examine the pbysical characters of the salt in viirioys 
wayts liut only rarely and aiutiou^ly^ by the jmlale, on 
account of the danger of so doing. 

If the salt is, to the eye, whit4-% little more than tracer of 
distinctly colored su!w*taaceM can he prewmt; if colored, the tint 
may indicate the natiiire of the HuliHtaace or of one of its contitit- 
in^utH, supporting that the student its already acquainted with the 
colorrt characteristic of eertiun salts, Cloi^er observation, aided 
|w^rhap8 by a lens, may reveal the presence, in a pulverulent 
mixture, of small cryntalf^ or pieces of a single substance* these 
shoidd he picked out by mean** of a needle or forcejts and examined 
separately. In a powder or roug:hly pulverizcil mixture of Kuh- 
iftanccH, the process of si/fintf (through t*ucii sieves as munlin of 
different degfiM^s of tincm^ss) often mechanically separate.^ suh- 
iftances, and thiLs greatly facilitates analysis. The suitstances 
niay present an undoubted metallic apjwan*nce, in which eaw; 
only the metals existing trnder ordinary atmof*pheric conditions 
need, as a rule, be Kotighl for. Feculiarily in smell reveals Ihe 
presence of ammonia, hydrrK'yanic acid, hydrogen sulphide, etc. 
Bi>tween the fingers a .substance if*, perhaji^, hard, wd't, or gritty, 
and from such a character useful inferences may be drawn. t>r 
the substance may be heavy, like the wilts of barium or lead, or 
light, like the magnesium carbonates and oxiiles ; or it may be 
one *)f the phanuaceutically well-known class of '*8<'ale" pre- 
fmnitions. 

% Place a grain or two of the salt in a dry test-tyl>e or in 
a piece of glasH tubing cli>8ed at one end, and heat it, at first 
gently, then more Btrongly, and finally, if necesftaiTi i» the 
blowpij>e-fianie* 

Oaiies or vapora of characteristic appearance or odor may be 
evolved, such as iodine, nitrous fumes, sulphurous anhy<lride, 
hydrocyanic acid, or ammonia* Much steam given offliyadry 
iHjlHtatice indicates either liydroxides or salts containing water of 
crj'stjilli/^ition. (A smflll *iuantity of interstitial moisture often 
caii»e0 heated crystalline substances to decrepUate—trom tiecrepOt 




366 




QUALITATIVE ANALYSIS. 



I fra4:klt — th;it ib^ hretik up witJi Hligbt explosive violence, owing 
Uj the t^xpiniHive fcirce of the stfani siiddunly goneriiU^d.) A 
Hubliniate umy reniilt, due Ut ^ilLs of iimijioininn, mercury, or 
arKiiic, to oxjilit' or Ik'uxoic acid, or to sulphur frue or as a sul- 
pliJde — a Nilt whfilly volatik cuntjiiiniig j^urh Kul>8tanc^a only. 
The tonipounU may bliu-ken, pointinjjc to the ]>re8eufe of iirganic 
matter— whirh^ in nnlinury wilu, will (vrohfibly be in the form of 
iirrtateH, tiirtnit4*H, tind litraten, <ir a.^ common Malts of the iilkaloids 
nior[>bine^ quinine, «tryi'bnine, or w< j^tiirch, wugar^ Kiiicin ; «jr it 
may be in cjther detiiritij or indefinite fonnw coiiimtm in |diarmiicy, 
iUid for winch tests will be given in subseijuent pa^^es. If no 
cbarrinjuf iKXurn, the inqiortJint fact in e^labliwheiJ that organic 
nnitter i« not likely to be present — except j>crhaprf cyanides, 
forjnates, or oxidates, which do imt char. The residue may 
change color from the presence or deveb^pnu^nt of zinc oxi<le, imn 
oxide, etc., or melt iVoni the presence id^a fusible suit and aknence 
of any large proiwirtion of infusible wilt, or be nnaltered, iihowing 
the jibsenee of any large amount of such «uljstanceii. 

8. Place a grain or two of the salt in a test- tube, add a 
drop or two of eoiiceidrated sulphuric ueid^ r*iutioiufhj smell- 
ing any gas that may bem'(dve<l; afterward slowly heat the 
mixture, noticing the effect, and stopping I be exj)eriment 
when any sulphuric fumm begin to e«*eape. 

Iodine, bromine, and nitroun or cbloriaedike fumes will reveal 
themwelveH by their color, indicating the presence nf iodide^^ 
iodatcB, bromides, liroujateH, nitrate,^, and eblorate«. The evolu- 
tion of n colorless gii^, fuming on coming int*i contact with air 
jind having tm irritjUing <»dor, points t*i ehlorides, flnoridcH, or 
niiraten. Gji>H'out* prf)diicis luiving a greenish color and odor of 
chbrrine indicate cldonit^*?!. bypochlorilci*, ivr chlorides mixed with 
other substiinees. Slight ^^harp explosionn betoken chloratea. 
Evolution of colorlejia p\s inny proteed frotn cyanide**, acetates, 
solpbitlei*, sulj>hite8, earbotiate:H, or oxalates. Charring will l»c 
tbie to citrates*, tartrates, (jr fither organic matter. If none of 
tb esc effects is produced, most nf the above- nann^l sulistance^si are 
alwent or only present in niimite pro(*ortion. The suht^lant^eH 
apparently unafTeekHl by the treatment are metallic oxide**, 
borates, nulphates, and phosphates. 

4. Expose some of the sijhManee to the blow-pipe flame on 
platinum wire, with or without a head of l>orax or of micro- 
cosmic tmlt^ (stKlium, amnion iiim, hydrogen phosphale, 
NaNH^HPO^, 411,0) ; on platinum foil, or in a porcelain 
crucible, or on a crucible lid, with or without sodium curbon- 

' So imiletl hecaiiM formerly obtained fmm the urine of maa, who wai 
mllm! the ?B«rroro*ni/*« nr UtUe irfirtd. 




I 

b 



SOLID SUBSTANCES. 

ate ; or on chnrcoal, alone or in conjimction with s<idiiim car- 
lxuiate» j>otasj*iiim fyaiiirU\ or cobalt nit rjitt^ Tliis ex [>eri intent 
will sonietimea yieM iTn]w>rlnnt infornuition, e4<jK'<*juny to one 
who hii^ clfvoted much uttention to reactions [inMliicilile liy the 
hh>w-pip6 flame, Thr niedical or |>liarniaceutieal Mticleiit, 
bowever» will stelilotu have time to work oyt this subject to an 
extent sufficient to make it a trustworthy guide in analysis. 

Methwh of Dismlviug and Afiniijzhnj Suifjleor Mixed 
Soiid 8n bski n ee^. 

Having aahmiiied the substance to preliminarff exuminathn, 
proceed to dii<mhe and analyze h\j ihejvllommj methofU. These 
operatwns cmiftid in freaditfj the weil-jtowderffil Attlmttince eon- 
secutirehj with cold or hot wafer ^ hifflroehhrii' acid, nitric acid^ 
nilro- hydrochloric acid^ or JitMtntj alkftll-metnl carhonateH ond 
dismhin^ the product in water and acid* The reHulliug liiptidii 
ore aniilyzed in the manner already dettcrihed, or by sUghtiy 
\'jfodi.fied processes m detailed in the following parayraphs. 

Solution in Water*~Boil about a grain of the salt preaentecl 
for analysis in al>out a third of a tej*t-tul)oful of water. If it 
dissolves, prepare a !a<>Jntioii of about 20 or ^?0 graiii!^ in 
half an ounce or more of water, and prtjcryd with the analy- 
sis in the nana I way, testing iirai for the metallic radical 
or radicals by the j)ro[M*r grtmjj-reagenls i 11(1, IL^S, NH^SH, 
(NH,),CO^UNH/|JIP0J), 1*. 242, and then for the arid 
ntdical or radical*^ di recti v or by the aid of the preiierihed 
reagents ( H^SO,, Ba(1^, iM']^, AgNO,, FeClj, p. ^2. 

If the salt is not wholfy dis^fwdved by the water, ascei'tajn 
whether or not any has entered into dilution, by filtering, if 
neeessary^ and rautifnisly evapirating a drr^p or two of (he 
elear liquid to drynesti on phitinnin f<iil ; the presence or 
al>senee of a residue gives the information sought ton If any- 
thing is dissolved, prepare a j^nffieient ipnnitity of solution lor 
analysis ami priK^eefl as usual, res^Tving the i(is<»Iuh!e portion 
of the mixture, after thoroughly exhausting with water, for 
8ulj*iei|yent treatment with aci<ls. 

Solution in HydrocMoric Acid — If the sah is Insoluble in 
water, digest about a grain of it (or of the insoluble |}<jHion 
of a tn i X eft sa 1 1 ) in a fe w d rc» jjs of h y d rm' h 1 o ri c a c i d , adding 
water and bfnliug if necessary, If the salt wholly dissfilve:^, 
prepare a suffieieut ipnintity of the litpntl, m>ticit»g win t her 
or not any effervescein^e (due to the presence of snlt»hale8, 
sulphites, carbonates, or cyanides) occurs, and procee<l with 





358 



QUALITATIVE AlfALYSIS. 



the analygifl as before, except that the first step, the addition 
of hydrochlorir juid, nmy be oiiiittefK 

The itniilysiB of this solutkm will hi mo»l re?*pei'tj* be simpler 
than that of an aijiieiiu<j ?M>]utiuii iiiji><iiiui'h as tht* niujority of nails 
(all tbf«**^ «<>kib!e in whU.t) will Ih* abstut* This acid dilution 
will, in wh c> rt , only eon tiii ti : — f h 1 u ri t iv» j i roti u eed i ly I he ac ti t m 1 1 f 
tlie hydrochloric aciil on sulphides, sulphites, rarl>onaU':^, cyanides*, 
fixides, and hydroxiiles ; and certain IwiraleH, oxalal4:*i4, phn.Hphatert, 
Miljihatew, tiirtratcH, and citrntc-^ (poswibly silicuteK and fluorides), 
whit h are insiolublo in water, hut soluble in acids* without 
apparent deetjuipoftition. Sul[)liid(^, nulphitej^, carlMjuales, luid 
cyanidt^i will Imivc rcveiiled theniselvc>« by the oeeurrcfR'e of effer- 
ve«<ceuee during >*olution; anil the presence of oxides and hydnixitlea 
nmy (|>. 361) Ih' inferred l>y the alii^cnee of e^mipiitible acid mdieHlg, 
The Iwiratc's, oxiilateH^ phosfdmtes, tiirtrale.^^ and eitrates^ alluded of 
will he reprecijdtated In the HVKteniatic analysis ai^sooii a** the aeid to 
the Holution is neutralized ; that is, will eonie <lown a« nueh when 
aninnynirt and aninioninm hydroHulphide are added in the usual 
cours^e. Of the«i preci imitates, only the ealeiuni oxalate and the cal- 
cium and uiagnedum ]di(*s)diatt^need oeeupy attention now, for ba- 
rium Dxalrtte and phosphates i^eldoni or never occur, and the b+jratea, 
tartrates, and eitratt^ met with in in edieine or general anHlvais, an? 
uU soluble in water. Thesi« phosfthateH and, oxalates, then, will be 
precipiUited in the course of anHlysisaloni? with iron, their presence 
not int**rferrin|;: with the detection ot any other metal. If, frfim the 
unusually light t^olor of tlie ferric precipitate, phtj«pbat€«and oxal- 
ataiaresuspecU.'d, it is treated according to the following Table: — 

PREt IPITATE OF Fnf>SPHATES, OXALATES, FeRRIC 

Hydroxide:; etc 

Di.Hs^dve in Ht'h add citric acid, theo J^U^OH, aud filter; 
then follow the Table Ijelow. 



Filtrate 

Fe 

Add HCl ami 

K,Fe(CK), 

Blue ppL 



Preeiintate 
Boil in ocetic acid, and filter. 



Insobible 

White 
(OiiF.iikiy 
oociirhere) 



Filtmte 
Oi,(POJ„Mr,IFO,) 
Add (NHJ,tV>i, stir, filler. 



Precipitate 

white 
hidieatini^ 



Filtrate 

add Nn.OFL 

White put 

MgX" -^" 



lo ppt 



* Most oxalatea, after ignition, elT^rv(siM« nn the iidditiun nfftcid ; jftior- 
idea may be detected by the '* etcbing *' teat. 



kai 



SOLID ,SVB.STANCES, 



35^ 



In aDiilyKJn^ phosphates and oxakkw, ndvantjige ia also 
frotjtieiitly tak«."ii of tlie IUlIh that the phowpJiorii' radiLJil Ls wholly 
n^iuf»vefi \mu\ solution nl [ihospliatei* in acid by tht^ addition of 
:ii^ alkiili-ineUl aeeUite and trrrit' chloride, and wuhKi'r|Ut iit ebul- 
lition, aa dt»jK.'ribLHi under '^Phoj^phuric Acid"' (|j. 31 li), and ihat 
dry oxalate!* areconvrrttMl intocarbfjiiate^by ignjthai aa mentioned 
uridt^r **Oxalic Ai^id" (p. 'MH). 

Ortiiin ar^natt's* and ttrt^jnites, iufloiubh^ in water but *«<jluUle 
in hydpjchloric acid, may aceonipany the alnne phoHjihatt-s and 
oxalates if tmm any aixi^it hydrogen !*uli>hide Iul< not previously 
btHin paKHed throu^'h tlie tiulution, or hit> only been parsed lor an 
ittwuliieieut leaj^th oftiuie. 

If the suhfttiiDce insoluble in water doi^ ui>t whtdhj disjmlve 
in hydroebhjrie arid, a-st'ertain it' any haa euti^reil irUtJ scdution, 
by tilttirint,% if neeensary, and evajxiratin^' a drop of the clear 
liquid lo dryneiis on [)latiuuni foil; the [irc^enee or absence of a 
residue give.s the iutVirniatioii Rm^ht fon If anything is dis- 
!3*dvcd» prepare a sufficient quantity of sointloii fur analysis^ 
autl priKieed a^ usual, reserving tlie insoluble ]rt>rtu>n of the 
mixture, afler thoroughly exhuusting with hydnx hloiic acid 
and well wiLshiii^^ with water, for the lid lowing treatrueiit by 
nitric acid. 

Solution in Nitric Acid, — If the salt la iniwdnhle in water 
and hyilrochloric acid, boil it, (or that |>art of it which is 
inscduhle in these menstrua) in a few drofjH of nitric acid. If 
it wholly dijisolve^t, remove ex^'esi^^ of aciil by evaj^oratioti, 
dilute with water, and pnx-ecd with the analysis. 

This nitrie arid solution eaii contain only a few Huhxtjinces; for 
ncAfly all sidts soluble in nitric aeid are idwi soluble in hydroehhirie 
acid and, therefore will have laen removerl previnu>«Iy. Some of 
the nietalH, however f Ag, Cu, lig, Pb, Bi), as well as amalgams 
and alloys, unaffected or searcely atfceted iiv hydrochhinc acid, 
are readily attacked and ilisHolved by nitric aciil. Many of the 
Hulphides, alw\ in>w>liihle in livdrorhlorie neid, are dissolved by 
nitric acid, usually with **ejiaratinn of suljdiur. Calomel is eon- 
verted, by long boiling with nitric acid, int4> mercuric chloride 
and nitrate. The nitrates liere jiroiluced are s<»inble in water. 

The nitrie iieid eolation, as well as the hydroehloric acid and 
mpjcous tifjtutions, should he examined separately. A[*pareaUy, 
time would he siive*l by mixing the three solations together and 
making one analysis. But the objeet *>f the analyst is i<» s<'parate 
every radical from every other ; and when this has been parti idly 
at^coui [dished by solvents, it would be unwi«e to again mix and 
separate a se<*ond time. Moreover, stdvents often do what the 
chemical reagentH cannot do — namely, separate miU from ench 




r 



aKSSQ 




360 QUALITATIVE ANALYSIS, 

other Tliirt is inipnrtiuit, huLHimn'ii ha the end hi t>e attjiined as far 
as piiHwible in uiiidysis is not finly an eiiunR'nitiim of the nulieidH 
presi-Mit^ hut a knowh'dge <*f the actual iMtJidilinn in whieh they 
are present; the analyst iiiiiHt tslate^ when thiw is poswibh', of what 
8iilt**a given mixture wa.s urigiiudly formed — how thiMnetallic and 
aeid ratiieals wem origiinilly distributed. In aHeniptiiig this 
inui'h niu.wt he h^ft to theoretical t'oiiHideratioiiM, iind k is often 
injfHiivsitile t<i arrive at eertaiiily iieeurate coiielusionii ; hut a pro- 
cesii l>y which the saltn llieai!<*dvi_'« are separated iw of praetie^il 
a.s8istitnee, hi-nee the ihief advmita^^a* of analyzing separately the 
»tf)lutioiLH rofiuhing froai the aetiuu of water and aeids on a solid 
suti^tance. 

Solution in Nitro-hydrocMoric Acid, — If ihe salt i»r any 
part of a mixture of salts jh insolnhle in water, bydrtu-hhirin 
acid, and nitric arid, diget*t it in intru-hydrochlork- aeid^ 
warming, or even boiling gently, if necessary ; evajxjnite to 
remove excesa of acid, dilute, and proi.'eed as before. 

Mercuric Bulphide an^l Huhslaiiee5 f>nly slowly attacked ]iy 
hydnjeldoric or nitric acid, an, for ejtanjple, calomel jmd ignited 
ferric oxide, are sufficiently altered by the fi-ee chlorine of aqua 
regia to becoaie jwjluhle. 

Analyma of Insohible Snbdanee^, 

If the 9Hb^(fince is inmfub/e in water and aeith^ it is one 
or more of the following su I istance^ : — Sai^l tunl certain sili- 
cates, such as |>ijM?clay and other clays; fluor*spar ; cryoliie, 
NajAlF,; harium, strontium, and possibly calcium solphati:^; 
tinstone; autimonic oxide; glass; felspar (aluminiym and 
nlkaH-iiietitl silicates); silver chloride, bromide, or iodide; 
lead suli>hate. It may also l>e or contain carlkm or carlnm- 
aoeous matter, in which case it is black and condnistible, 
burning entirely or partially away when heali/il in the air — 
or it may be or contaiu sulphur, in which ciu^ sulphunius 
anhyilride is evolved, detected by its *Hlor» wlien the substance 
is heatcil in air. A drop of solution of ammoniuui hydroeul- 
phide added to a little of the |>*iw<ler will at once indicate the 
presence or absence of salts of such metals as lead and silver. 
For the other 8ul>stances, j>roceed according to the following 
( Bloxam*s) method : — 

Four or five grains of the dry substance are intimately 
mixe^l with twice the quantity <>f dried sodium cu rlx)nate, and 
this inixture is well rid)l>ed in a mortar with live times ita 
weight of defiagrating finx (1 of finely powdered charcoal to 



L 



INSOLUBLE SUBSTANCES, 361 

6 of nitre). The result! »j,' puwiler is [jlticed in ft thin porce- 
lain dish, or erueible, or dmu 'mm imy, ami ii lighted niuteh 
applit*ii to the centre of tlie Iiea|j, I >etlag ration ensue.s and 
dtM.^oinjMiiiitioti of the various *4uhstHn<'ei* ottinrii, the add 
nulicals going to the iilkali-metjils to ttirni kiiUh Hiduhle iu 
water, the metallic radical** being i>inuiitaiit'onj^ly converted 
into carhonatrs or oxides. The uuuss ig boiled in water tor a 
few Diinntes tht^ mixture iilteretl, and tin? residue well wanhed. 
The filtrat*^ may then be examined for acid ratiicali^ and 
alnminium, tin, et(\, ueoI the rei^idue l>e di^Sfdved iu dilute 
hy<ln«?hloric acid aiirl analyzed by the ordinary method. 

The only BulMauce which resit^ts thia treatment is chrome 
iron -ore. 

To detect alkali in felspar, ghusw, or cryrdite, Bloxaai reeom* 
niendu deflagratiou of the powderi'd mineral with one part ofjtiil- 
phur and six uf Imrluiir nitrate. The loiih^iH boiled in water, the 
taixtnre (i!tered, atimoiaium hydroxide and carb<nmte added to 
reuiove bariuio, the mixture again fdtered, and the filtrate 
evaporated and examined for alkali-njettil.'? hy the usual process, 

Hydroxiden and Oxides, 

If no acid radical can be delectc^d in a t^ubstance, or if the 
quiititity found is ohvifHifily inwutlk-ieiit to saturate the (juaiitity 
of tactalHc railical preset! t* the oeearreaeeof cixidcw or hydroxide^ 
or hotii, may be su^]leeted. Confirmation of their presence will 
be found in the general rather than iu any wiiecial behavior of the 
subHtances*. S*Hoe hyilroxidcH yiidd water when heated— iii a dry 
te»*t-tul>e lield nearly horiziintally in the flame, t*o that moisture 
may condense on the cool (lart of the tube. J^omc oxidcn yii'ld 
oxygen — tlelectixl by heating in a test-tuhe, and inst-rting the 
incandesi-eiit cinl <»f a strip iji woorl, 8<duhle hydroxidiw *'iuu**c 
abundant evolution of aumionia when !u*ate<l with soluticui of 
arainoidum chloriile,' Soluble hydroxides alsii give eharacteriatic 
precipitates with the various metal iic Holutiuns. Hydroxide** and 
oxidci* insoluble in water, not only neutralize anich nitric aeid^ or 
acetic aciil, hat are thereby convertiM into sfdt.s siduhle in water. 
Most oxides and hydroxides have a elmracteristic appearance. In 
nhort, wmie one or more properties of an oxide or a hydroxide 
will gcMierally betrsiv it^ presence to the student who not ofdy has 
knowledge respecting' ebeaueal suhstiuiees, but has cultivate*! the 
faculticH of (d>st*rvalion and perreption. 

*Red 1itmuii(>fiapcr placed over the nioiilh of a t«jst-tul>e ru which ammcv 
nfiiiii chlitritJo HobUioti silmie i^ fx^inj; hfiilefi tarnu blue^ hut pliutiol* 
plhMlctii |itt|M*r ifl nut uUffNil. 



J 



362 QUALITATIVE ANALYSIS, 

Fractiomil Opemiimu. 

Not only in the common iircKieiit* of sifiing (p, 365) through 
sieves of varymg degrees <>r fineness ii us*eful fnittioiial operation 
or separatory adjunct in analytical u* in other Wf>rk, but also 
fractional dufriatmn (p. I'M)^ Iractiorial aohdion oj' a mixed mwm 
hy Hxhnaiion (p. 89) of the snb»tiuice with f*ucces8ive sm^ll quan- 
t!tie?i of solvents, and iVac'tioiiiil />rtTipiAi6V//* with Iiltriition after 
each addition of snect^^sive somil tpmiitilie^ of u precipitiint ure 
niten valusdde aiilw. Fmctional dUfi/htfimi {ai'n p. 420) is ofti'ii 
very unefnl, fraitional miblimatlon (ji. 96) and fractional crysktUi- 
lation (p. 82) occasionally^ fractional /usU/n leaa oilen. 



QUESTIONS AND EXEHC1SE9. 

Deeeribe th© ppclimiimry treat ni«nt to vfhkh n «iU may li« subjected 
prior tri systematic auiiLysis. — Mention siibatiiiires which tiiigliL be rvcug- 
niz&tl by smt^U.— MuDtioo twimesalU which ar« heAvy* and mmw which aro 
light.— Name aom^ substances rtiCOKiuzablt^ by their cobir,— What in !*er- 
ciic© may be druwu from the apfH^araiic^ i^f Hlcaui when dry suhHtaiic** 
ar« heated?— Why do certain crystalsdccrepit^iU*?— if a pywdi^r Huhlimcs 
on being heated, to what ila&iefi of coinptiuinlH may it belung?— When 
heat cansciH charring, what cunclusioti ia drawn ?^No change f>ecurriiig 
by heat, what suh-staucea cannot 1h3 present V—Uivo exunipU^H of salts 
which are ideutiln-d by ttieir behavinr with concentrated Mjiphuric acid, 
and by their comportment in the bl(jw-]H|)e fbiine, with or without borax 
or micr(K!*Minie salt. — What are the mil vents nsmiily empluyed in l•Qdl^av• 
orliitf to obtain a auljstanct^ in a stjitc of solution, and what i^fi the order 
of their application?— Vani« a few satt^ which niny b*^ prr.sont in an 
iwjueous sohition, — Mt'Utinn soniecfimmiMi compnundL*^ insohibb* in water, 
bntsolubl*? in hydnM'hloric acid. Wlnit Htibstauces are only at tack e*l by 
nitric acid or nitro-hydrocbhjric acid?— At what sta^se r^f unaly!»if« do 
ar^eniteitand arseiiatef^rthow theniaelvt'^?— Ski^teh a methinl for the com- 
plete analysis of a liquid susp«M:ted to be an afj ii eons Mihit ion af ncntml 
salts. — How L^au alkaliue-earth^mctiil phonphates aud tjxabitcjiHnd ferric 
hydroxides be !k?iianitt'(l fr»jm each other /—How would yon prtK:ei>d to 
miuilyae an alloy J— By what process may substances insoluble in water or 
loidfl be aualyKcd f — How would you qualitativ4ily auaiyzu glass? 



RKCAPITULATORY AND OTHEE NOTES ON SALTS. 

The molecules of a salt contain radicnU which may he either 
elementary or compound (pp* 52, 04), 

Each nidicHl ha« a definite excbangCHblo value, but this value 
may ditfer in the ca^ of different radicals (p, ♦)2). 

The relation to each other of the nidicids in onjanic fmlninncce 
or Halts, 13 apparently much more comjdcx than the rf'latioii to 
each other of the mdiealH in inorganic or mineral buIIh. 

BrrthofiefR Lawn. — " Wben we cause two m[i» to react hy 
means of a solvent, if, in the coiirw of double deconipoaitioti, a 



THEORY OF SOLUTION, 363 

new salt cnn be (irrwltJi'ed leHs .soluble than those wliich we have 
niixiHl, til it* unit will he pnidiucd." "^ Wlieii we apply dry hrat 
to twfi mk», \i\ by dtjuble dt'i;omiJi>sjtii>n, a new !«ill t^an he pro- 
duced more volatiJe thau the Halts previously mixedj this anh wiJl 
be prudueed." 



THEORY OF SOLUTIOTT. 

The phenomena of eleetml yniw have given rise to a new theory 
of solution, Fonneriy a sail was guppoaed to cimfii^t of a basic 
oxide eomhimd with an arid oxide ; thna **suiphHte of soda ** (as 
the Halt u«iw known lus H<Mliuru syl[>lijile was eallt'd) was regarded 
ai» Na,*>,JSi»5j. When a Si^utiim ol Hodiurii Huljdiate in elei trolyzed 
{see p. 67), fitjdiuni bydroxidt^ i?* funned id the negative, and s\iU 
pburie acid at tlie positive eleetrode ; theT^t* suhBtanees were huj>- 
j>«>!*lhI In Ije priKJueed hy the uninn of the ,'^(>iliu(n uxide with water 
at the negative eleetrode atid<jf thesiul[dmrie anhydride with water 
at the positive eleetrode. To atxi^unt tor »neh jiheroiineaa a new 
theory has, htjwtner, hefii brought forwaixl^ aeetirding ttj whiehp 
a saltr — e, f/., wxHuni sulphate — when diH,s^)lved in water splits up 
int4> an ehx'trn-iHLHitive and iin eleetr<^>ne^ative part, but these 
are nmv hnpfMiHt*d to be, not tlu' ba^^ic oxiile and the aeid oxide, 
but the metnllic *tT basic radieal and the aeid ladieaL Sodium 
aUjms or iV>/m eunstittite the positive j»arl, iHul|djate radieal^ or 
Milpbatlon^ (*^**i) ill** nef^ative part ; when an eh^etrieal enrrent ja 
paiised through the Kohitioii the former lose their ehar^'es <»f posi- 
tive eleetrieity at the nepitive eleetrode and then art on the wat^^r, 
fonning Hodinm hydroxide and liberiitin^' hydrogen; the xuljdia- 
tiom wmihirly lo***' their ehargt?H of negative eleelrieity arul then 
decompose the water at tlie positive eleetnHh% forming sulphuric 
Held and liberating oxygen. When Arrhenius hnnight f«>rward this 
view, a new thei>ry of H*>lution wsu< murh rieiMied^ fur it had Inen 
found by careful meaftureinenls that the thermal change involveil 
in the aet of solution could nut be entirely aeeiuinted Ibr hy the 
physical change of state. Arrhenius asnumed that a salt on jniss- 
Ing into sfdution undergoes more or U^» complete sc[>a ration into 
its ion« (ionimtion), and that itnionj* net independently of each 
other, not only in elect roty tic, but alno in ehemieal proeeH»ej*. In 
gtnierah we find ehemieal activity, in the sense of nmdineM to 
undergo doubh' rleeomposition, to go hiind in hand with eleetrieal 
eomlnetivity, ami his explanation is thait the real carriers of the 
eieetrtcity are the free ions, which, hy virtue r»f their freedom, are 
chemically active*, since they have not to he se[iarated from each 
other before they int<*ract 

This bypotheHis of the existence of free ions in solution liAS 
thrown much light on the general iM-havior of salt solutions, and 
hm rendered possible an explanation of many hithertu inexplic* 
Me phenomena. 




364 THE PERIODIC LA W, 

THE PERIODIC LAW. 

When the t^leiiients are arniTigid in thv ordt-r oi' llieir atomic 
weights, h m ibnriU that, starling with lithium, the eheuiival proper- 
ties of eiieh 6^ucee,sMive elejuent tlilJlr in nnuiy vuaeH only to a rehi* 
tiveiy small degree trom those of the element iunnediiitely preced- 
ing. This holds lor a * 'period'' oJ' (at firi*tj seven ideuients, and 
then the eighth element showh a eharp ehiiuge rd' propertie** from 
lho!*e of the seventh and a striking regetnblaiice to tJiose of tlie 
tirnt ; the iimth re^-mbhs the second, the tenth res^embies the third, 
aud m on. The first two piriods toiiFist (d\si ven ehnientw each ; 
the suhstMjuent tint^, which itreuiore or kss coniiilvte, of fieventeen 
each. In the following Table the periods are arrange<i in perpen- 
dieular columns, whereby kindred element^ are to a large extent 
brought side by side in the same liorizoiital linei* : — 

Tubh ofthf Efements, nrrangt^ to iUuHratv the Periodic Law. 



t«< 




... 


K 38.86 Eb 84.8 


Dj 13L9 


*ti 


• ^. 


• ** 






Ctt 39.8 


sr mm 


fia 


i;m.4 


««. 


... 


•(• 






Sc 43.8 


Yt 88.3 


Ln 137.9 yti 17L7 


It* 


»>• 




<♦. 


Ti 47,7 


Zt 89.9 


O 139.2 


... TIj 230.8 


■ *■ 




... 


V 50.S 


t'b 03,9 




<«■ 


Ta IBI.6 




•" 




- 


Cr 51-7 
Mu 54.6 


Mo 95.3 




- 


W 182,6 U 


236.7 


«4< 




**. 


Fe r>ri..^. 


Kij 100.9 




... 


r»fi isQ.a 




■ •■ 




».. 


Ni r>H.3 


Kb H>>2 




... 


Ir 1*»L5 








... 


€k> 58,5<J 


Pd 100.7 




... 


Vi 193.3 




Li 6.'98 


Na 22.88 


Cii 63.1 


Ar 107.12 






Au 195.7 




Gl a03 


Mk 


24.18 


Zii 04.9 


Cd 1118 






llg 19B.5 




B 10. d 


Al 


2b'.y 


i.hi 6!».5 


In 113.1 






Tl 2irZS 




C 11.91 Bl 


28.2 


tin 71. f> 


Sii llR.l 






Vh m^Mo 




N 13.93 


P 


30.80 Afl 74.4 


Sli 119.3 






Bl 20(1-9 




1G.88 


S 


31.82 


Se 78.6 


I 125.9 






4.. 




F IB. 9 


Gl 


3&.19 


Br 79.36 Te 136.6 




,,. 


... 





It mU lie notieed that there are papn in the Table sug^sting 
elements yet U) be diw.'r»vered, nr indicntiajL^ uncertainty as to the 
correct prnition of a nnni!>er of known t h mentw ; als<* that there 
are irregrularitiea fqi^'^e*<tin^' the desirability of reconKiderinif ^ome 
of the prej^ent atomic weights*. Dther ditfirultie?* uIho oeeur, but 
Btill the regidariticj^ are so hlrikinfr as to show clearly that the 
properties of the elements are in tsotue way dependent on their 
atonae weights. 

The nature of flome of the progrcfwive relations to each other of 
the inember^^ of the tir»t two perifKln art* iHiistnitt^l by the fonnuli^ 
ofcertnin of their coni]MnnidH when placed side by f«tclc. Where 
blanks m'cwr, t-ilher lio coinpouiitl at all, ur no illuHtmtive com- 
|Kmnil, h known. 



L 



THE PERIODIC LAW, 365 

Compounils with oxygen : — 

Ufi Uld 1^,(), CO, N,(\ — — 
N%t> n^} Al,M, 8iO, \\i\ H\ — 

CoraiMmud» witli liyilrngeii : — 

_ „ __ CH, NH, on, ill 

=_ _ _ SiH^ ni^ SIl, t'lH 

ComjHjumiii with L'liluriiie : — 

LiCI (*KL mi, CO\, NO!, (X^l, — 
NiiCl My!^i\ AR'i, 8iCI, PCI, 801, — 

The coinjiouncls (V>riF»i(hit*^d aJ^tivi' nn^ not the wholi^ of (he*>xy- 
jren^ hytlr*igv'(i, ami riih»riru^ c^uiipoiiiuls of the vurinu.s ek^iiu'Ufi*, 
but are chifBfii io ilhislnite rfguluritii^ um fur as posHihh". ThiTe 
are, however, a nuFjiher ^if irrej^iibrities iu thtm- jieriodii, and iu 
iho jtutwetjuent periods irregnhiritii^H beeoiiie more nuineroui*. 

Since the jM»«itif>ii of \\x\ element in the tiUiVf Tidde iw Hxed by 
its atomic weip^ht, tim! sinee it hux been tbmid that the pnipcrtieA 
of a0 element und thf! rhiiniLler id' its eom pounds emi lie foreseen 
to a ccrtjiin *'Xtent from thuw of itw nei^hborH in the Table, above 
and beh>w, right and k ft, the grneral Htiitement haj^ been enunci* 
uteJ, bti»e<l upon ibis periodic lirrangement and .supiwirted by a 
great deaJ of eviiltaice, that thf prfrprffitu of an rinnrni and the 
ncfure of iU compoftnfh nrt funHwn\ nf ih nfmmr: irritfhL 

An iniipectjcm of the foregoing Table shows how allied elements* 
ah* brought t/>get!ier in gnni[>H. Thun the haiogenH (with the 
exeeptkjn of iodine ') all tall int<^> one line, and the i^nme in tmeof 
the groupM of kindred elements, ealeinm, >^trontinm and barium ; 
nitrogen, phtis[de>ru.s urw^nie, andanrirnony i etc. Further, eaeh 
of Ihe firwt tivr period,H is heattx! I»y an alkali-metid. Thi* ?iyuil)olft 
printed in black tyjM' are those for tb«' small gn»np of elciiirntM 
usually elaiwt'd m non-metals^ and indkate the remarkidde riiilnre 
of the jM)«itiun of Uu^- elements in the j>en<Hlk! j*ystem of cla.s*<ifi- 
caiiou. 

* It memn as if the true p<wTtion of Jortmu in the [MTiiMlic »yatt?ii] jihoiikl 
ho iiftfT jnM^'jwl (if tx^fort^ kdlfiHam. Tlii^ respective itlaL^en »A.sijriic<i to 
kMliiit.i juici U'lhiHiim il^iH'ticl, liow^iver, iiptm tlie di*Uinuiiiatk>UH mF Hie 
Atomic wuighUt of thcjkj vlcmohte! whk*U are cuiisklured to bo tbii iiiijal 



366 ADVICE TO STUDENTS, 



L 



ADVICE TO STUDENTS EESPECTmO THE 

METHOD OF STTJDTDfa THE FOLLOWINa 

PAGES ON ORGANIC CHEMISTRY. 

Ik>th mpflicai imd phaniiiueutit'iil stitdentH of organic chemiHtry 
may be divided iritvi twr* clasneH, iininely \ junior »twient«^ i>r thwm 
vvhn, in the first instance at all events*, desire to obtniii only a 
general awiuaintance with tbe subject ^ and itenwr iitudentu^ or Ukjbc 
who, bavinj^ B<mie gcnerjil inforrimtion, desire further knowledge 
ol" this bnineh of the seieiiee. To the members of eaeh of the^e 
chiswM who usi_» this M^Hial, some advice eoiieeniiiig tliekindimd 
extent of work they may hojie ti> aeeoniplitib in tkis department 
oftiic seienee will perhaps be iieeej»tal)U\ 

Jimittr Sfuffml^. — The whole of the following section on organic 
clieniiHtry should Ikc read through carefully once or twnee, with 
the object, not s*) much of remeaibering all that is^ i^ta ted, aa of 
aequiring (a) a genend view of the six»pe of the subject, (if)acleiir 
notiim of the modcH of classifying organic substanceM, and (c) an 
intelligent percepticju of their liroad relationship t<* one another. 
S|»ecial attention shrmld be gi\x-ri to the methods of preparing 
and testing the particular subHtiinceH ollicially recognized in the 
Pharmacofio^ia, the student of practical chemistry y>re|mnngaetual 
Kpeciuiens of most of thesf? mib.stunces, as well m studying their 
analytical reactions and testing for impuntien in them, lie shonld 
prepjire small cpiaiititics of cblor^iform, iodoform, Fpirit r>f nitnuis 
ether, acetic ether, and a vobilile oil ; sliould extmct gum from a 
gum-resin» purify Pome benzene, test aloin, und examine methy- 
laled spirit of methyl alcohol ; prepare some aleohol by fermenta- 
tion, c(»ncenirating the product until it will burn ; make etlier ; 
cf invert amyl alcobol into valeric acid ; test carbtdic acid and gly- 
cerin ; manufacture a Mpeeimen of sciap ; extract mannite from 
manna ; examine the analytical reactions of cane and grape sugars; 
obtjiin starch from \vheat-tloiir» maize-flonr, and a potato), and 
examine each product with the microscojie ; make dextrin, pmxy- 
lin, find collodion ; prepare and test aldehyde, and try the action 
of lime on chloral hydrate ; prepare and test acetic, oxalic, and 
citric acids ; emulsify s^weet and bitter abniindjij r jirepare elaterin» 
and tent jalap-resiji and wliein ; extract niorjiliine or «juinine, r»r 
both, and perform the t<^ts for the chief n!kiilcH<ls of opinm, cin- 
chona, and nux vomica; test iilbnmiu and pepsin. Having gone 
tlirougb the^^e operations, he nhoubl read again through the whole 
Mcction, 



ADVICE TO STUDENTS, 367 

Senior Sfudenis, having done all that juninr Btudenta are, in the 
previous punxgniph, iidvLsetl to do, jrihinild thoughtfully study evtr)^ 
page, rending what one (»ther author^ at least, has to say on each sub- 
ject. J[!ire espfeially they should actually jirepare, or test, ur other- 
wise experimrnt with, one 4jr laore tyjdeal nienilwrti of moMt of the 
Beries*, or sub-seriet<, of organic snbstiuR'ei*. F*ir example, they 
«hcjuld prepare the fajthmarbmi methane (from sr>diwm acetjite), con* 
%*ert it into a Moid drnrdtire (by om* of the pi^iveii inetbod^^), tnniK* 
form this int*» the afcohol {\>y the ageney of s*ilver oxide and water), 
and this u^ain into the ttat) (by oxidation). The pre[*a ration of ace- 
tyh'ne, and ethylene, anrl some of their deriviitives, Khnald be tried; 
Ibe ditlerences between turpentine and petroleum spirit sbould be 
experimentally {*roveil ; nitrobenzene sbuuld bu made, this be eon- 
verted into aniline, and thi« again into ** mauve"; aloinsHonlrl be 
preparer! ; methyl aletdjol t»e extracted from crude wood j^p in t, and 
abKolate alcohol l>e obtiiined from *Valeoh(*l {^^2.'4 percent,)'*; 
jile<diol ani] acetic acid should be rej^^enerated from the acetic ether 
previously prepMrerl (by elmtliti*»n with m concentrated aipieouB 
wjlution of potiLssiuni hydroxide); ethyl iodide or brouiide and per- 
haps zinc-ethyl be niarle ; glyeol lie prepared and then ^ixidi/etl ; 
glycerin la? examined ; starch be e<jnverted into dextrin nnd into 
sugar; malt extract be examined for diastiiHc ; trinitrocellulin be 
made ; acetaldehvile l>e fully examined and aldebyde-animonia 
prepared ; lactic acid he mafle ; bt^nzoic and salicylic aci<ls and 
aldehydes be obtaine<l ; natural urea Ix^ extnicted and an artificial 
urea made ; the ghieosides be examined ; and one or twn artihcia! 
alkah»ids be prepared ; eic. Mel ting- points jiud boiling-pointwof 
pure Mubstaners sbr>uld lie taken ; and fraeti*>nal diHti!lali<in should 
be applie*] either to acetic acid with a view to s^-jnirateglatMd acid 
i>n the one hand froni water or weiik aqueous acid on tlu* «itber. to 
Tuixed alcohol and water with the object of attt'Oij^ting their 
re-Heparatic»n an far as jiossible, or to s<tme Hueh mixture. Espeei* 
ally must the opcrationn uf quijntitative analynis of organic ccan- 
jMiunds, in due time, he fully and tborraigbly performed, 

O/Zif'r *SyHr/i'^j/^,^^^tudents who have no orra,sion to apportifin 
their perirats «d' study in the manner conteaiplated in Ibe previoUR 
|»anigrat»hs are recommended to go through the suceeedinK sections 
un they huve gone through the foregoing, namely, page by page. 



r 




ORGANIC CHEMISTRY-^ 

iNTROIiUCriON. 

With the exception of al<n>iicjl, .some nmh nnd their saltj^, 
1111(1 11 few other suhHtnuees, the large iiiimher uf eonvixHiiitls 
wliirh have hithert^j eiigiitred the f^tudetit's iioliee in this 
MMnniil have het;ti of mineral origin. Bnt the tsvo either 
khigiloni^ of Natart\ tfie animal and vegetalilr, furnisli still 
larger nnmlM-ra uf dehiiite ronqwiirnds. We shall now pn»- 
eeeil to the considi^ration of the^e, the latter I'hieHy. 

In its original .si^nitieatioti what was termrtl Orgaoio 
Chemistry (J'^pyavny.onjnnon^ an organ J emhraeedtheehemistry 
of those siiUstance.^ whieh were known only as i>ro<liietfl of the 
vital procei^es which take plaee within the tissue of plautd 
and of animals; and, further, the chemistry of the various 
products derived fnmi these i*ubstant't*&, or from the tii^ues 
themselve.ST by snhi^quent treatment in the lahonitory. The 
sepiirate el as?' ifi eat ion and C4>nriiderati<»n of these sul>stiinc*e9 
formerly seeineil ex|M-<lient in view of the fact tlmt none of 
them eould theti l>e uhtaitied hy t!iH ordinary operations of 
theehemica! laboratory, starting from non-«>rganized niateriali^ 
The term ** organic ** as originally applied to any mibstanee 
WMS thii8 intinmtelj associated with the view that orgaoized 
matter — living matter, or mattor which had at one time 
("urmed jwirt of a living plant or animal— was nwessary for 
it>i pnKlnctioo, ^Methods arf m»w known, hi>vvi*ver, whereby 
a considerable number of .subj<taneeii wlneh are identieal in 
every respect with known produi*ti* of ania»al or plant life 
(or with derivatives from these) can he prcpartnl in the lalio- 
mtory *' artificially/' as it ia otleu terme<i, from purely inor- 
ganic materials. 

1 Students will find tlmt in t^kin^ op the subject of orgaDic chem- 
ifitry they lire not dt'i-iiirthig fruoi the method of study liitherto pursued. 
Hitherto thpy havf t'oriccnlrated attention mi thi'i^hiff elemeota, oneiit 
n trtno ; they urc now atioiit to inve«<tigittf tin* i-oiripi^und.'^ of unoof thot^ 
elenii>nt«i which fM»ssi*aees » iifreHt'er mn^e of couihiuiuK powers than any 
other tlis4t has lieeu cxiimincd. Organic chemifitry is the chemi»try of tho 
element <vii6oh. 



hH 



INTROB UCTION, 369 

Organic cliemistry luis been di-titietl in more recent times 
as the i'heiuif^try of the cc)!ii[x>uu(ls f>r earhon. There does 
nut, liowt^ver, now weem to l)e any good reason lor eliL<^siiig aa 
orgaiiie, the oxy^^en mrnptyiiiuls and Rmie otlier relatively 
eiiii[»le I'orMiKiiinds of earlvon, inelndinii^ many of the naturally 
Ot'iuirriug minenil carlmuales ; more |wirticnlurly i\b the^se 
must, for the sake of eoiupleteuesH* lie dealt with under the 
htniding f)f inorganie ehemifitry. It m tliiir^ im|Mi«sihh^ to fix 
the houndH of iuorganie and of orgjinie chemij^try res|>eftively, 
unle^g i\u arbitrary line h tlrawu, \vhh*h sludl nuirk a <li8dnc- 
tiou that is wholly artiiieisil, anil is n(»t founded ujion unyi*etil 
dilferenee in the general nature of tlje faet*s and principles 
lnmte<l t>f under the two headings. There Is in short, hut 
one s(;ienc'e of ehemii^try, and tlie s<-parate eon^ideration of 
the ehemistry of the majurity of the eijm|>oundii of carlion is, 
to a large extent, a matter <jf eonveinence caily. The very 
great nund>er of the eom|)ounds of ciirhon and the eomplexity 
of many of them, together with the general n ad ine*w which 
they Uijually exhiint to enter into new^ condiinution^, may be 
mentioncfl aa among the reasons for their separate study^ 
The *me fnndamental fact eoneennng every so-ealltMl organic 
comjjound if*, that it contains carbon as one of its constituent^, 
Otmdnncd with one or more other elements; but, as we have 
alre^i<ly seen, every comptjund of carbon is not anorganiecom- 
ptHind tn any sense which it in convenient strictly to define. 
Of course, so old and historically interesting a term as fmjanic 
chaiihfry will continue to be used ; and tluTe is no obje^-t km 
to such use, |>rovided students remember that when the term is 
Qaed^ it isonlyeonventionally and not etymologically accurate* 

It w^ill be nunei*esBary to discuss again in w hat tbllows the 
chemistry of those com pounds of earbf>n which have already 
been treated of in earliiT jMirts of the ^fanual. 

As inj^tunces of the formatii»n, from purely inorganic 
materials (or from |»rodncts obtainalde fmin inorganic 
itiaterials), of coniptmnds which are generally classed aa 
organic^ the following may he mentioned : — 

fl) The formation of acetylene, C^H.^, by pashing electric 
sparks fnwn carbon terminals in an almospljerc i>f hydrogen; 
and by the iiction of water on caleium earliide. 

(2; The turmution of jKitjissium cyanide, Kt'N, by pustng 
nilrogeu <iver a nirongly-heateil mixture of pvtassiiim and 
carlion, or ot* |x>tai<«ium carbonate ami earlxju heated to the 
tem[)crature at which |x»tassium is liberated (p. 72)* 

24 



370 ORGANIC CIIKMISTRW 

f*^) The format Sou of murah ^riia, CH^, hy passing a mixture 
of hydrogen sulfiliicle uiid va|>or or cjirboii bisulphide over 
red-hot cuinyer. 

(4) The Ibrmatiou of urea^ ('( )| Is^ll,,)^ Uy the nrtioji of 
ammouia ou i-urbouyl chhjrick ( phusgeu ) ; jiud by eva|KinUing 
tn dryness a si^lutiou of tim morn urn cyiumte. 

(5) The tbruiiilion of potiKSHiuiii forniute, KIICO,, by the 
action of earbunie oxide on [KJtas.^iuiu hydruxide, 

Elemenh which enter Info the compotitioH of organic Suhtianc€$t — 
The elenieuta which, beside I'lirhon, iire of tht* gri'uk'f^t iuipor- 
taiR'e froin their *"nli:riiig riirint fn'tjui oily intf> Uk' riinij'*i?*itifio nf 
orgioiif suliKtJou t'H nre liydrogt n^ «>xygen, ;iiol nitmiroih AH the 
naturally otrurriiig urganit^ t^ubstaueos (.unitjiiii rartmii uml hydro- 
gen, jiKHfiriati.'d almost always with oxyi^in, and oftni willi nitro 
gen; Home of tlunn also eontuin suljihur or plKisphorus (>r both, 
in i^nnill quantity » Among atrtifirhilly prejiiired c^rganie suh- 
Kt4itK'i%s, eiiuipountls bave beeu tjtilainetl t-oiitaining ahiinst any of 
the other known ilemenU. 

Ihftction uj the iuinon» i/cmeHfji preiffnt in Orffmiic iSlih»tant€i.'~^ 
It i}*nf>t intemteil here to give any detiiiled aeefamt of the analysis 
of organie i^ubstiuiiTs, Imt the general jirinei|»let* and a few im- 
portiiiit iiH thods limy jidvantt*geou>ly be outlined. 

In order tc> denmiistrate the ]iret*enee of eomhined carbon «nd 
hydrogen in imy substant'e, it is usual Ui burn a sTmill quantity 
of the suli.stunr*' in n enrrent of jnire dry air or oxygen in a hard- 
g\as& tube chisely paeked lor a part of its length with eiipric 
oxide whieh in kept red-hot tbronghont tSie o[>e ration. The cur* 
rent of air or oxygen enters at one end of the tube and the 
gaseous products of eondaistioii pans uut at tbe other. During 
the i>rocess the carbon and hydrogen of the substance are com- 
pletely oxidiztMl — the foraier into carbonic anhydride and the 
latter into water— and the pn\H nee of the two elements is indi- 
cated by ibefornnUion of these respective jrroducts. This proeeits 
can he made rt nu^hml of quantitnthe analysis, since, by collecting 
and determining tlie weighls ot the two produeti* ubtainnlile from 
a known weight of the organic sul>stanee, dala are ohtaiued from 
wViicb the proportions by weight in which the two elements are 
prcvsent in the substance can be calculated. 

The pre&euee of nilr<jgen in uu organic sub»tanee is detected by 
strongly heating a few f^ruins of the substance in a tesi-tulie with 
a small piece of metjdlicsiKHum, grinding up lire tn^ed nniKs with 
wat4^r, filtering, and examining the ndutiou tor the |»resence of a 
dissfdved cyanide. In the pn>eess the nitrogen of the substance, 
along with some of the carlMiu, i-ombiues with the scNlium U* form 
sodium cyauide, Xai'N; and the iibRTvation thai a cyanide has 
U'eu formetl is a pnnif of the presence o! idtrogen in the *<ul>- 



INTROD UCTION, 37 1 

stance. Part or the whole r^f the nitni^en of H^ime (hut rint of all) 
f»qifjmie stib,^UirK'es4 is evulvecj a.s miinioiiiii vvben the riiil>?itaiiee is 
uimlfTHk-ly hrateii in a teHt-tuhc with rtfnlu-liijR^. ' Thv ♦jusintita- 
tivi' (k4eniniiiLti<m ot iiitrogrii in i-lh ctiMl by variour iiirthods, hut 
the only one whiih neeci l)e iiR-iitioiu^d here is iiii!ilti|^cmK to that 
employed ihr the dett"rmiii3ili<Mi of cnrlMJii ami nf liy\ln>geri. A 
wei|(hed quantity c>f tlie sul>st:ineo J.s heatt'd in a. slow eiirrtMit of 
carbonie anhydride in a glaf^s-tiilxu'outuining fujiric oxidt' whirh 
i« beuted red-bot. The nitrogen is liljenited either an .^ueh, nr m 
the i\>r\n of giiHeouH oxide of nitri^en. Before emerging froai the 
tube the mixture of gaM'rt piissi's f>ver a *|uautity uf red-hot eoiipcr 
wire-gauze, tightly jiackech The Imtt^^r reti«iiiH any free oxygen 
by i'timhining with it to form euprie oxidej and als<j diTonifmHes 
the oxide.H of nitrogen, f<ijuibirly retaining tliu oxygt^n of these 
while the iiberiited uitrogeu [)as.s<^ ou. The earbouie an by d ride, 
wakT vafMir, imd nitn^gen whieh eiuerge are paiised int^i a gradu- 
ated tuhi* eontaiuing a eoneentratt d solution of jiotasiiium hydrox- 
ide. Therarbonie ardiydride is here alisi»rbe«l fonning potassium 
airhonat*% the watur vapor eontleJi'^es to form liquid wiiLer, and 
the pure nitrogen is colleete-d ami its volume is meitsuj-ed. From 
tbe oljserved vidume, under the comlitions of temperature and of 
prt'Sfture which ha.s also been noted, the weight of the evolved nitro- 
gen can lie calculated. 

The pre?4enee of oxygen in n noU'Vohitile orgjHiic substance can 
usually be tletected liy simply heating the dry substante in an 
atmosphere fri»e from oxygen, and observing the formation of 
water, Tbe oxygen neeesHary for tbe prod urt ion of water, in 
such a ease^ must havt^ In^en present in tlie siihstanet* unck^r ex- 
amination. The direct qnantitalive detfrndnjition of oxygen 
preHt'Ut.s comHiderabh' experimentiil diflirulties, and no satisfactory 
method for making thi* determination haw eomc into general u»e. 
It is UMual iu actual practice to determine thequantitii'w of all the 
othtr cleaientH prest^nt in a given weight of tbe substance and 
then to ri^gard tbt* remainiler as the qnantity of oxygen* 

In order to detect sulplmr or phosphorus in an organic i<ub- 
stanee, the latter is*, in most niscj^, first oxidized by somu suitable 
[mM'fAH, and the oxidation pniduidf* are then cxiiniini-d for the 
pre?*enc'e of ^ulphtjric or phos|diorie aeid. Tire quantitative di^ter- 
mi nation of thes*^ rlcmenis also usually re<iuircs oxidation »i» a 
preliminary* 

Tbe detection and quantitative determination in tergal ric sub- 
stances of other elements, sueh as chlorine, bromiiitr, iodine^ 
nii'tids, etc, require in general tbe oxidation of the substance or 
the tiecompi»*iti**n of it by some other prricess, and the subsequent 
exantinntiori of the products of MUeh operations hy the niethodw 

*Tlio priMlui^t i*btaia«d by slacking quicklime witb a Bolutiou of sudium 
hydrosiae. 



^ 



372 ORGANIC CHEMISTRY, 

of qualiliitive and quantitative analysis applicable to inorganic 

(rrntntl effects of Ilea/ upon Orf/nnic Suhstancrji.— -The *tffbct« 
prtKlucetl by heating various organic snlKstani-es vary greatly in 
till;* <'{LHc^-^ r>f different eompfnindii. We shall briefly connitier 
I lie general i^lleeti* (I) when ijrganic Biibs^tances are lieate<l by 
UiemHelveH, that i», out of contact with any tiling niort^ than atnall 
quantities of air; and (2) when they are heated with free accisas 
of air. 

(1) 8olid organic substances when healed may t^iinply become 
liquid, and the liquid «o produced may, on being further suffi- 
ciently heated, huil and he completely volatilize<l withtjut under- 
going any decoaiposition. Glacial acetic aeid and aci4ainide are 
t'xauiplcM of such guhstancci^. (_)ther solid Kuh.stances mtiy simil- 
arly beeoiuc liquid, hut the liquid <*u further heating may dteom- 
pci.se heforc the tfuipi'rature of volatilization haw been reiiched. 
This in llie ease with cane sugar and with urea. IJther scdid »ub- 
sliiiiees again, such a^ sta^rch and felliilo.st% cannot be liqut'tie<l by 
heatiug them heeansi* the leniperature at which deeoaipiisition 
taket} place'lies below the lemjjeraturuof liquefaction. *Suhstjinee» 
beloDging to these last two chLssci) very commonly yield on 
decomposition by heat a quantity of volatile pniducts (some of 
which are gaf^m»aud «*thers Ut|uid at ordinar}' temperatures) and 
leave behind in the vessel in which the decomf>osition has taken 
place, a highly carbonaccoun, non-vtdatile black re><idue or clmr- 
coaL Charcoal siiit^ihle for s]jerial purposes is often |ireparedby 
thus healing sbirch, "Ugar, cellulose, etc. When non-vohitile 
organic sulistancei* are subjected to this treatment the proce*« 19 
calUnl dry or drsfructivf dintUtatmn. Such pr*ic<^sHCs are carried 
nut on a very large scale with wood, with c<»al, and with different 
kinds of shale, and form a part of several important manufactur- 
ing indust rit^. 

()f organic substances which are liquid at or<l*nMry tempera* 
tures, a very large number, such n^ ronimon alcoh**! and ether, 
are capable of volatilization without decomposition, white otheni, 
surh as glycerin, dK'ompost^ at tempeniture?! helow their boiting; 
point"*. Substances wliich belong to this latliT clH?<*i cannot 
then 'fore Ik" distilled without decomp<wition, at least under onJi- 
ni«r>' pressures. In some instJinres it is found poe<sible, by 
diunnishing the prcivHure inside the distilling apiniratus, to lower 
the boiring [ioint of the liquid to a temperature l>elow that At 
which decomposition takes place and so to ensure its diHtilliog 
undccompt>sed. 

Organic stdwtancc whit h iire gases at ordinary lempenitur«v 
and the vaj>ors of organic mibstjinc^'i^ which fire solids or liquidfl 
under these eireunistancoi but whieh volatili/x- undecomposHMj, 
maybe exposed to the actiiMi of high temperatures by slowly 



rtii 



INTRODUCTfOK 



373 



pftislng them through heiiteil tubes. Undor this treatuieul Mime 
decoaijiose readily^ whiU" tithtrn do do! untltT^n itny, or at leiLHt 
any eonsidembie, vhaage. A iiu-thod frLM|U<ntly rimtie U8*' of for 
very rapitliy heating a va|jor, Im tliat t-inphjyed in tbe iiiiinufiuture 
of ** oil gaw'- fn>itj parallrnoil. The lit|ui(J oil is ml lowed tfidrop 
on a red-hot aietal or hrirk siirt'iiee^ when the vapor whirh is at 
first produeetl heeoiiieM very wtrotigly heated l)erore it has time to 
difiu.se away froai the hot surfat-e. In this Wiiy the panittin nil i» 
dec*miiJOi<edp yielding st^tiiw coke and e<mibu«tible giwes which do 
not become lit|uid agiiiri nt ordinary ternperatureH. Tlit« t»pertition 
is technieally called ** cracking '* the hydrocarbons of vviiicli the 
paralfiu oil iu eomponed. 

(2) When organic feubf*tancet^ are strongly lieatc*! in suitable 
forms of apparatus with free acce^H of air, tliey Uhiually undergo 
complete oxidation^ so far, at lea«it, sis their earhon and h}'drogen 
are eoncemed. Thene elements become converted into carbonic 
anhydride and water resjteetively. When a huH of any of tho.se 
organic acida which contain carbon, hydrogen, and oxygen only» 
Li ftubjeettHl to this treatment, the carbon nniy either be com- 
pletely ilriven off' ax carbonic anhydride, or a jiart may remain 
combined in the form tA' a ciirlHiniite. The metal of the siilt may 
reuuun behind either m metal (Hilver, pbitinnni, etc.) or m oxide 
(Iciid oxide, zinc oxide, ferric oxide^ etc,) or a^ carbonat^^ (potas* 
Slum cjirbtnate, harinai carbonate, etc.). 

Dhfiikttion, — The pnrilkiilion of organic mibstance^ in often 
effected by distillation, iis, rorcxamjde, when a vtjlatile Kiiljistanc© 
is impure from the prest^nee of liiiy non-v«»latile admixture. The 
separation of alcohol by dintillaliiMi from the non-vidatilc eonstrl- 
ueut8 prei*ent in the iirpiitl of the fermenting tun is an instance of 
thi« kind (p. 420). 

A mixture of two or mf>re liquids (all of them volatile, but tjf 
different boiling points when pure and unmixed ) nniy be njore or 
less completely separated by '^frnrtinniti dUftfiatiim *' — that is, by 
Bt^parately collecting the portions of tbe (iistillate ( **fr:ietion« " as 
they are calb d) which distil at different temperatures, ur nither» 
within certain intervals of tern j k' rat u re, Hnch fnictinns do not^ 
as ft rule, conHist entirely fd' one single liijiVid, l)Ut generally con- 
tain some of the other volatile substances present in tbe original 
mfxtnre. By snlijecting each original fraction t*) a sc^ctnjd iVac- 
tionnl diatilhition, ami systematically carrying out the same proc€M 
on Buccee<iing frnctions for several times, fractions of almost con- 
0tant boiling point, and couiposed idmost entirely of one liijuid 
can in many instances he obtained ; t>nt in wane cases notfiing 
more than a very partial si'|»rt ration can be etfected. Thus frfmi 
a mixture of alcoliol and water it is not p<i«*ible by distillation 
ftlonc, to obtain alcohol containing less than about 5 percjent 
of water. 



374 ORGANIC CHEMISTRY, 

Clamt^of Organic (hmitfmniU, — The majority of orgjinic emii- 
jMiundH are coiiveiiiently *rnuijjed intolvvo main cljLSKt^, whiuh are 
known as the Fatty {<>r Alijdiatir), ami tiie Ammatic i'.liLi!i>es 
reapeetively. Wht'ii tlie>ie names were iin^i emiiloyed, ouJy a 
fomparadvely limited nuuiljer ut orpujii! i"onii>ound.s wereknovvi). 
The natural (abi gave riwt^ to ti nntuher nf reprt^-Hcnlative.^ uf the 
first-idflsi*, whiih may all be regarded an denvativt-H of methane, 
CH. ; a confide raldt' numlKT ui* rejiri^entjitives fd' the second 
claiw, which may l>e regarded aw derivatives of l>ea/X'ru% C^Hg, are 
more or \em aronnitie substant^es, sneh as Kome of the eHi*eivtiai 
01 It*, etc. The words tatty and aroauitie are of hif^toricid interej^t, 
hut although in er>aimon use, they cannot now Iw) looked upon us 
very apitropriate. In dealing' with tbe fulty or alipbatie mid the 
Ix^iizene or aromatic compounds, the,^* two chiHwi-js will only be 
conKidered wiiarately in so far m a moderately wyatematic treiit- 
ment irniy seem to re*piire. 

Oms^tiftttmn or Sirnrhire of fhifitnie Compoun*ij*\—Thi' problem 
of the relatiyn!4 to one another of the Yjiriiai^ atomK which com- 
pose a molecule, is one which early altrnctcd the interi'^t and 
attention i^f chemists ; and it is one Ibr the sidntion of which 
mattTials have ta'en aeeuauihited slowly and laboriously fnaii the 
nynthetical ami analytical ia vest ij^at ion hr>it t>f the simpler and 
afterward of the more eomjdex chemical (*oi»i[Mmnds, inorvjanic 
and organic. How to recogniKe the presence r>f certain groups of 
atoms, or radicals, in the nodcculcs of chemical Hubstiinces, and 
how Ui timl out the position of thest^ groups in the mfdciules is 
often a most dirtii ult and yet a moi^t h^»H'inating tJisk for the 
enthusiast and Bkillcil ex])erimentjilist in chendstr)' ; juid how l^i 
ao marshal tbes<.* grraips (drawn jierbaps frrtm .Kcveral different 
jM^jurces, iind obtaiuidde only in a slate c»f coaibination) that he 
shall protJnce by art the compound r^riginally only fyrnishe<l by 
nature, i« »till more difficult, but also more fascimitlng. 
More fascinating firstly, iK^cauw it will furninb proof that 
his synthetical work was Mound; secondly, iieeause by artificially 
mid perhaps cheaply prtduciiig a rare color, a nire perfnme, a rare 
flavor^ or a previonsly costly medic im-, he may become a Vieiie- 
factor to his fellow-man; and thirdly, iKM-anse he may gain tlie 
honor of unveiling for all time one more of the truths of nature. 

In practically attjieking the problem of the conslituti«iri i»f a 
compound, the chemist ]irocee<lK to note whether t!ie snbstanee is 
acid, alkaline, or neutral ; to act on it with a haw of known eon- 
stitution if it \» nn acid, or xvitli an acid of known eonslitution if 
it h a htis^, ,qnd to analyy^? the produced salts ; to oxid(7>e it ; to 
deoxidize it : to beat it; to electrolyy^e it; to eldoriiiate it ; to 
remove or add hydroxy! (OH), carbonyl (CO), etc, ; to snhstitnt<» 
hydrogen by a compound rjidical, and cjW fvr^S ; and, generally, 
to perform many such operationfl, in the hope that the lines of 
chemical cleavage in the molecule will he detected, the eas»ential 



INTRODUCTION, 375 

grouf*iJigs of atoniH in tlic molwMilo \w iliscnvLretl, luid even the 
p<»riiti<»ji8 nf jitoiMH iir grouf)(.H <»f mIoium in rrlutitin !<» rach nther l>e 
R'UH^mjibly iriftTn^d. iSriL-riy, sijuilarily in pntjuMlien iiu|>lie!4 
!*nnilanty m I'liui^tiUdion or strucliirL*. /V mtttrti^ siinihtrity in 
Htriit'turi' iM^iuik' reMj+niuibly inijilivii, rctVrence to |»r(i[tt'rlii's sbiiwa 
wlR'ther nr nni tlie reaf+tni \s \n\ the ri«j:ht tniik towurd trutli in 
the mutter of rari^litutiun or :^trnetiire, the inJvjmee touanl error 
iMMrijki: i»revenl<Hl and toward truth being niuiiitttined whatever he 
the result of the ndereJiee, new truths not inCrequently being 
unveiled. Thus, hy the way, in ekeniiMtry, do fact and theory 
ever di^^eliarj^e their obi ij^ittittn?^ to eaeh uther. 
. Soiaiion of Organic Compotinrh, — In order tliat we iiuiy eonvey 
Ut one another our eonelusii*ni* resjiecting the eon.stitntion of 
orgjuiie eoHi|)onnds, notation ba^ to be eiirried ,son»e\vhat fsirther 
in orgjinie than is ns a rule neeensjiry in inorgjuiie ehetni!*iry. The 
rebitive jm^iiions of litouis and gnaips of atoinH in a niob^eule may 
be iudieated by ]dja in<:: the Hvnilxdie letters above or 1m neath i>ne 
antitber as well uh on one line, and the i^uantivaltMiee of al<ims, as 
well «« the ways in whieb we eonebide they are Linked in the 
moleeide, may be hifheated by lines ( — = )(>rdots(, ; l) 
either eom|detely or only partially eni|doyed throufrhout the for- 
mula ; eaeh dot or line or '*lhik:/' or **bond," representing the 
»uj»pnsed cnnditifai of union between two oeijurbljorint? atoniK or 
nitlieal^. Formnbe whieh, by the aid ofsuth dots <ir lines, jmr* 
port to repre-ient tlie relative positi<ms of the atoms and ^•'n>U|>s of 
Htoin«i in rnoIeeulcH fi'. **., to re [> resent the constitution »m" strneture 
of (he mrdeeuh*H) sire eallnl i^fmnfttftfnfunj or nfritrfurtif fotmnitr. 
Many exanifiles of nueh forimibe will be met with in tbesueeeed- 
iii|r padres of this Manual When struetural fonnulie are written 
in the most extended form, m^ n« to repres^^nt by the aid of lini»« 
the way in whieb every atom in a moleeuh^ is united to it** adja- 
cent alomn, the resulting: fornmhf* are often ealhi! i/ntphic formula;. 



QUESTIONS AND EXERr^ES, 

What d*^ yon nnderstand br orjrnfjir rbt^iidstry ?— f?ive niethiwU of 
asrertrtJainK til*- pro^-w^nee ofrarbitii, hyilmiriMi, and nitniKca in orffiiiiic 
eompoands— Oive an nuilinc of the Bi*?th<Hl« by whieh the ipiaatities c»f 
earhoa. hydrogen, oxygen^ jiiirl uiinrnen ure de terrain tn] in orjinaie enm* 
IMiuncl^i— What wmf^mtby TnirntHnil" distillation?— Name two nf the 
ehl*'f I'lassf's info whleh orpinir r<tnipoaail«iare clivirUMl. — Ilftw ts Iht^ nm- 
(ititatior* of an orir*inireonijMniii<i n-wrrtained ?— What do yon wmUrHland 
by eonstitutional or Htrtirhinit fi>riiialje?— What are graphic formula*? 



HYDROCARBONS. 

(lonipuinds known as hydrocarbon h eontnin the elements 
hydrogen aiirl carhon only, and are exceedingly numertius. A 



376 ORG A NFC CHEMISTRY. 

very larg^e number of tbt' kiir^wii iiydrocarlxms iMiUmg to the fatty 
class, three of the chief grtiujifl being the ramJfin, the define, ajid 
the A eety 1 e ne neri es. 

THIS PABAFPIH SEEIBS OF HYBBOCABBONS. 

Of all the known hydrocarbons, the aimpleat in compostitiou k 
niellmiio nr miirwh ^il^, whicli is the firHt meinber of tbe series 
called Paruifins. In this .ntrics uf byiiruiiirlxjiis (niid in it ah»ne) 
the total combining caintcity of each carbon lUoin i« j^atisht^l in 
HUcb Ji nianiier (citWr by linkagf with hyilrogen atonm, or with 
other carbon atoms, or, ii« Is abiiost ahvjiy&t tlie cast% by linkage^ 
partly with liydrogen atoms juid partly with other carbon atoms) 
tbat the nieudjffs of the series are not capable of entering into 
direct nnion with chlorine or bromine, sc^ as to form additional 
com ( >oun ds* 1 1 c nee t b e series of p ara tti n s i s o t tt^ n ca 1 1 ed t b e se ri es 
of safurnftd }iydrf>carboni^. Methane is the otdy bydrwarbon 
which has the total combining capacity of its carlH>n «itii*Ik'd l>y 
linkage with hydrogen atoms. Iti compoMtion i& represented by 
the formula CH^ 
H 

I 
or H— C— H. 

I 
H 

Tf we fsnppoHe one hydrogen ntom of methane to he renio%*ed and 

m place to be taken by tbe groni> — (il, ^vvbieb is called nicthyl), 

we get the comprwition of the next s^implc^*! pjiratlin, ethane, 

C,Hj. There is no rea»*on to Knppo«e that any one of the four 

hy<lrr»gen atomf* of mctltane difFerw in the lejLst IVoio any of the 

(dhers in the wjiy in whieb it in rt lated ti> tbe carbon nUmi and Uy 

the other three hydrogen atoms. Thui* <»n eonHidering iu the 

n 

graphic formula II— C — H, the relatjona of any jiarticular 

II 

hydrogen atom, we Ree that it is linked to a carlwm atom which in 
turn if* linke<i to three other hydrogen atom:*. Acc(trdingly it is 
immaterial which of the fonr hydrogen at^)m!» we 8upp«)se tt» he 
replftce^l by the methyl group, iH-cause, if the relations of all four 
are similar, there would in any ca^ result the suhatanee ethane, 
H H 

H — C — C— H. Ethane is also a pandBn (the second of the 



PA HA F FINS. 



377 



iienes) and containn twti carlMjii at^nns, eurb of whit-h Lm linkt^l 
onr-fuurth to cartxin nm] tlJ^ei"-f<^urlh^^ lo liydniiLjt^ii. 

Jliit jiiHt JUS ill iiietbaiie jiiiy orn* <if tiie fbur Imlriij^mi atcmis k 
n*lnttMi to the sin^Jt^ fiirhnji iil<>jii in the nauK* way a^* any ♦»(lier, 
so ill eilijiiie, any one of the six iiyiiroj^en atoms is relateiJ U> one 
of the carhmi atoms in Ihf saiiie way a-s any other is. 

ThuH rm t'onHidering, iti the graph ie fonnuhi for elhaiie jnst 
giwn, the rehitintiH of any one of the .six hydrogen at^Hiis, we m!« 
tlisit it U linked tf» a earbon atom whieh is in turn linked to two 
other hyilnigeii atoms and to the gronp— CH,. The rehitum of 
eaeh hydrogen atom to wliat is called the ^*earWii nueh/us/* in this 
ease (J — C\ is the Siiine. llenee if we si»|t|>ose one hydrogen atom 
of ethane U^ 1m? removed and its jtlaee tn he tiiken by the grouj» — 
CHj, it is immaterial in this ease also which of the hydrogen atoms 
we HijpfMtse to be thns repliieed. The resulting eomfxmnd is pro- 
pane, <U1.| the third hydrocarbon of the paratHn Ht^ries. I'onsid- 

II H H 

eratioo of the graphie form nla of thi« ?4iibstanee, H — t ' - 

III 
U II 11 
reveille the iW't, hfiwever, that all of the hydrogen atoniH are no 
longer similarly relateil to the earUin iiueh^iis, (J — C — C. Eaeli 
liydrngen atom is linke<l to a earlion atom a.s before, but whih:^ six 
of the hydrogen atoms are linked to the two end earbon atonm, 
wliieb besides are vme-fourth linked to earhon, tlo.» two remaining 
hydrogen at^mis are linked l<i the eentral < arbon atom wbii'h in 
one-luilf linked to rarboiK The eight hydrogen atomn in jiropinie 
are thus divisible into two groujm, consisting of six ami of two 
n>j<peetively, aeeordtng to tlie [xwition in the earlMni nuelens of the 
eiirUm atonii* to whieh they ji re linked. If then, we nnppose one 
hydrogen atom of propane tfj Ije removed, and its plaee to l»e t^iken 
by the gronji — ^^\l^ it mat/ not any longer l>e immaterial whieh 
atom we sup|K>Hi* to be thus replaced. The resnltiniL' compound 
will in any Ciw<» have the composition^ C^llj,^, but it is evident that 
two cliJIerent arnmgemeutH of the«0 atoms arc pownible as indicated 
by the fortmihe : — 



i^H. 



(1) 



H II II II 

I I I I 



H H ir 

I I I 

and (2) 11— f^^CWt;— H. The for- 

H fl H H H ( H, H 

mula (J) would repres<^nt the arrangement in the case of the 
replacement of an end hydn»gen iitoni of propane by-^' 11^ ; the 
formtihi (2) that in the <*jiiie of the similar replaeement i>f a central 
iiydrogen atom. Ax a matter of fact, two (and only two) paraflinn 
are kntfwn, Iwitb willi molecuhir weight eories(Kinding to the 
fommlUf CJI,o, but iliffering from e»ch other in properties, Tho 



378 OEGANia CUhMlSTRV. 

foriimlu (1) i.s assuiued t<* repris^^ht ime uf ilirsi* lvv«> coin|Hmruli* 
wbirli is nil led imriiMil buliiiR-,, ami tbe romnila (2) ti> ivj>rest'iit 
till* iiihvr which i.s calliHl iwjbutjine. 

Altboujjrk it is lieyoiirl tmr present inteiilioii to follow oiiieh 
furtlier the j>n>j*4ible varieties in tlie eoiii*titutioij of the eimipoumls 
wliii'li we miiy reganl ils derived iVom ** lower" iiaralliiiH (i. t.^ 
piiriiffinseoiiUiiiing in their luoU'Cuk's n Hiriiillcr lunidjt'r ofearlxiri 
atoiuH) by the reiibtceiiierit in tln^e <if iliJleretit liydrogeti atoms by 
the methyl group ; it may he well tjo [inu'eed here i>ije ^^tep further 
iji iluA direftiori in the la-ses of noraia! butane iiihI isoluitiuie, both 
ofwhieh we may regard stn derivi'd, by this kind of rej>laeemeut^ 
fn*in pro|iane. 

Thus on C4jnsidering the hydrogen atiims of tionnjil butane (for- 
mula (1) n\xiyv} it is seen that bix of theai (the two eticl *iet.H of 
three each) are linked U* two rarlwrn jttoms whirh in turn are one- 
fifUrlh linked to earbon mid jire botli related in the ;<ame way to 
the earhon iiueleus, while the reiiojinin^ lour (the two eentral iU'i» 
of two eaeh) are linked to earhon atoms wliieh in turn are one- 
half linketl to earht»n and are both relat<'d in the same way to the 
earbini nueleiis, hut that any one of the j<ix has gi^t the sano* kind 
of relations to the reuiaitiiiig atoms h\ the moh^ule as any other 
<tf the six hai^, imd that any ^me of the f<mr has likewise ^ot the 
sjiuit- kind of relatione to the rrmaining atoms in llie molecule as 
any other of the four luis. P>om n<»nnal bntune ihen, if we sup* 
pos4» one hydrogen atoai tn he re|iho*ed by the nulhyl group, it is 
eimeeivablethat two diflerent substanees nnght hi* diriveib one of 
wbieb would be representeil by the tbrrnuhi — 

n II H H H 

Mill 

H— f— C^C— (^— ('— H, and the other by the forinuk 

I I I I I 
H H H H H 

H l\ H H H IT H IT 

H— (L-C-43— C^H or I{.-C'— C-4!— r— H. 

HCH.H H H llrn, H 

But on consider! nir the hydrogen atoms of iso butane (formula 
(2) above) it is st^en that Jtine of then i (three sets id* three eaeh) 
are linked to three earbon abims vvhieh in turn are one-fourth 
linked to enriMm and are all related in the same way ti» ihe 
carbon nueb'Us, while the remaining »me is linked to a ejiHxin 
atiom wdiieh in turn is tliree- fourths linke<l to earb<*n and differH 
from sill the others in its relation Ui the carbon nueleus. Tho 
rehitions to tlie remiiitiing atonw in the moleeule, of any one of 
the series of nine hydrogen atoms are of exactly the Mime kind m 




PABAFFIKS. :W9 

lh<if*e irfnuy other iittlu^m, nw] tht^ rt'liitioiw of eatli of tlunii are 
t!il!'tTent from lliose uf the f^iiigle liyilrogi'ii atotti. Hvt^ ai;ain 
theii^ if we.su|*[msi.* iHie hyilrugeri iiumi of h^ohiitiine to be replaced 
by the methyl group, it is eoneeivahle thnt two (iiflerent sub* 
stiiiiees* ioighl be <Wri\\Hl, of whirh i>iie wouhl he rej^reistmU^l by 
the funnuki — 

H H H 

I 1 1 
ii-V—V—C—H ; 




and the other by the formula H^C— C— C— IL 

H I H 
H 

But c"omparison of the forrmihi given for tho neeond of the coa- 
eeivjiViIe derivaiivert frnju oornial Ijiitiuie with thsit given f^ir the 
rirst of the eoneeivable <h'riv!itives from isobulaiie niiows tluit thew 
two are i lien lieu I, am! that t lie re fore there are tliei^retieally ouly 
three paralFiiirt of tile f^irjoiilat '^11^5 deri\iihh' fnao tlie two liutiines 
by the replacenient r»f one hydrogen atoai by the grou|> — *'H-. 
As a mutler of taet three ]»andliiii* (ami only three) jire known all 
with moleeiilar weight corni^ponding ttj thin fonaahu They are 
ealled [a^iitjines anfi Ihey ditlor very eonaiileriibly from one another 
ill their pn^jHTtiei^. 

Immrriffm, PniffMrri^it^ Mckimrrmii. — -The oci'iirrenec* ol' two 
Of more HubKtanee?* pot<?^*}S(<iiig the same eeiitewinial eomptisition hut 
difFering in pn>iH*rtie^ at* exenr|»lified in the eawH of a nundvr of 
the pMralTins mentioned in the foregoing jairagrajthH, %» very fire- 
cpiently met with, ewpet ially in t^rganie eheinistry, lSubst«nL'<?8 
whieh HtancI in this relationwhip to eaeh either are termed immt*ric 
(fnmj t(T*trt m'm, e*jual, and r//>K^, mtrtm^ part) ; ami their e(»nd)tion 
i««pnken of asotie of Uomt-rmfi, There in Konu'tinien good reason 
for doubling or otherwine innltipiying the formula of one of two 
mjmer*^ homerith:K^ or iwimerie Hiihstaneen. Thus a niohi'nle of 
ethylene (oleliant ga**), one of the chief illnniinuling ei>nstituent« 
nfeoal gas*, in re(jre?*eut4'd by the formuhi t'^M^, while a nirdeeule 
of hutyiem\ a hydrocarbtai Iiijving the »«une jHTriiitage eouiponi- 
tion as olefiatrt giLi, is re|)reKentefl by the f^jrnndu <\H^, bwaUNe 
buiylenc in the atate of giun U specifically twic<; jw heavy wa «thy- 



J 



380 ORGANIC CHEMISTRY. 

lene, aiui nmst contain, therefore, in em h nioleeulo; twiw as 
lujiny atoms, ,siiiee (AviiiijiKlro) e(nui\ volunu^H of the HtjliHtjiiicets in 
ihe gtuseous slatt; ami uoiKt ihe siinie con<|ition.s contiiin e<|ual 
imiiiberi of OM^leeules ; ita foritmla i.s, tuustHiiientl>% tixH in con- 
formity with tbese facta. Thin variety of i^ouieriam 13 termed 
polfjmensm ifr'^in jto/ic, polm^ many or nnnlj, and tdpin;, jiart). 
Formaldehyde, CH/), ai'etie acid, CgH^G,^, ami lactic licid, Cjfl^Oj, 
furnish another groujt illustrative of pulynierissuu Meiasl&nnic 
acid {ftttf j>. 195) ift a poly aierie variety {fKihjmt:r wt pohjmrridt) of 
stannic iicJd. An example of umither variety of isomerisin ijf seen 
in the case of ammoniiim evMJiate and urea, f<ubstimces already 
alhided to in connection with cyanic acitL The«e and Bevenil 
other pairs of chemical sutnUuiees have dis.simil:ir properties, yet 
are similar in the cent-e^mml proportion of their eleuient«, and we 
cannot avuid the conclusion Ihal each molecide j»o«isestH's the same 
nttmber of atom«. But the reactions of these substiinces indicate 
their probable ctmHlitutitm ; and thld is repres^ented in their tbr- 
iiiulie by the disposition of the symlx>ls. Thus arnmoniuiu cyanate 
18 repre^nled by the formula Nli^CNt), urea hy < '^(NlIJj. Such 
Huh?!tjince« are ternted mnhtmn-ie {from fura, ituia, a pTO.]Hmltl*in 
flenoting change, and ^*/jf>c), and their condition spoken of as one 
ot mftaf/ierimn. Ethyl acetate (p. 40'f) in metani eric with butyric 
acid (jx 453) ; they have the same j^ercenUige comp(*!*ition and the 
iiame vapor density and each might be represented hy the fomiula 
CJI/).ji ; but their properties wjirrant uh in aasuming that their 
ati>nis oeeiipy different po.sitiiuis in the two nKilecules — ^^jiLstify us 
iu writing ('H,.CtM)t^H^i4s the lormula for a molecule of ethyl ace- 
tate, anfl CjH^.COOH as the formula for a moleruh' of hytvric 
acid. Methyl acetate, CII,,C0OCIIj, projdonic acid, r,n,.C'< >6h, 
and ethyl formate, H.COOCJI., arc isomers of the metameric 
variety, or mefnmer^ or mati'tiwridrA ; also ipiinine and qulnidine, 
cinrhcinine and cinchonidine, many of the volatile oils, etc. 

Fhnwloiiom Serir^. — In the eonsideration, m far, of the series of 
paratlins, we have seen that, i^tarti ng from the first memlnT, 
methane^ each sueeeeding mendM-r of the series diHer^ from the 
one which immediately precedes it hy containing the group— C'H^ 
in the place of an atom of hydrogen ; or, in other words, by the 
common difference of one atom of carl>on and two atoms of hydro- 
gen (Ciy. ^I any other scries of sulwtanceft liesidcs the panifllnH 
are knciwn in which the successive members differ from one another 
by €^H,, or a nnilti]de of CH^. Such seriej^ are ealhd hnnohffmut 
(from ti^6r, homm^ the same, auil /<i>oci %/»«, projMirtion). The 
*' higher" members of the pamfUn series (1. «?., thost* containing 
in their molecules more than one atom of caibon) aw? calle<1 hrnm-^ 
hifurit of methane. 

Gehtral /nrmuhr for homoiogoti^ serien, — It is often convenient 
(and it iR always possible) to represent the general compoHition of 
the members of any homologouB ^ne» of compouDds hy meiinii of 



A 



PARAFFINS. 381 

a fr>rnmla. In the ca,se of the p;ir.iltins the general forunihi is 
u?^ii.tlly writtefi rjT^„'^,, where n ri"i*rei*enlj* the mmiber of carhon 
Htutii8 in a iiKilei tih' iif the L'<nni«ound. This fnrnujht Bh«»w» thiit 
whatever nuiul:>er oft-arhoii jittmis a. iiioleenle of tlie paralKii eon* 
tjiiiiH, it CMiritjuiis tsviee tliat nuitilier *if hydrcj^en atmns and two 
hydn>|reii atoms hisideH. The general foruinlje tor sojiie other 
homologous i^erie.4 will l>e given later in tlit'ir ris|>eetive plaees. 

Normnf f't(ntj^lfijt. — ^The terni tiormai ih applied to tlioHf nurallins 
in which the carbon nueleu,'^ in eapahle ot'hiin^ re |> resented as 
consiiitin^ of carbon atoms w I hnkod t^jrether as to fy rin a nngle 
"rlniin" without any *' Hifh^hrancheH*' (or ** sid»'*ehainH^*) ; for 
example, C — ('as inetliane, C — C — C i\s>, in prupanr^r^— C- — V — O 
iw in iiortrial butane, C — V — V — (' — (' an m uormal pentane. It 
will be observed that in tliest> **ch;dnH*' the earlxm atoms aro 
repreHL'uted as either oiie-fourth oroiie-hiiif liuked to otlier carbon 
atouiH, l>ut never more than this. (_'ontra>it thenc straight * * chaiuB ■ * 
with C.^ — C— C^ the earbfin nucleus of iwhutaiie, and with 
C 

and C — C — C, those of isopentane and of tetra- 

A h 

methyl inetham> respectively, in tbe firnt two of which one earlMiii 
atom of each ij^ represented as three- fourths^ while in the lasl^ one 
car) ion atom in represented as wholly linked to other carbon atoms. 
Carbon ahriuH which may thus he di.stiiignished in the carbon 
nueleuH by the different pro|Kjrtion of tlieir combining cat)acity 
which m satisfied by linkage with other carbon atonis^ are 
deKignod ji.H {jrimarVj ykH^-ondarx', tertiar)% or quat'eriiar)', acconi- 
ing a^ one-fourth^ one- half, three-fourths, or the whole of that 
combining cajiaeity \» &fi switistied. 

In conneeti<Hi with tliesi* rli>Hignation.H of carbon atoms it la not 
unimjKirtant to note that tliecarbon alt*ni in methane is notlinkefl 
tf» other e:irlM>n at<>m» at all but to hydn»geii atJuriH exchisively; 
luid that, with resi[>ect U* thia peculiarity of itn carbon atom, 
methane in quite exceptional and differs from all other hydro- 
cariwrjH. 

Occarrr/i/'f of Pnrttjffiftx in Xntnre, — ^[ethane or inarch gius 
CKX'nre VLA a product of the wlow decay of xegetable matter in 
pre!M*»ice «d' much water, a><, for example, in «tiignant jHwdrt^ 
niarnhy }daccs, etc., and alw a.s the ** ti re-dam [> *' cd' eoal tnine?*. 
Further^ methane and sevend of its h*imologne?*are f>re»ent in t!io 
ganei* which iHMUe Irorn the earth in the potroh'UUi region of Penn- 
«yivaniu and iu otlier parh* of the world; while the crude petro- 
kMint it^HcIf wbieh tlows, or is pum[>ed» from ihe earllj in the«e 
p!iicei4, alrto connists of or containj^ higher memberw of the Herie»» 
Formntlon of PnrnjffiriH in thf tirtf diMlafUm of ewtf, wnttii, 
shale^ Hr,^The volatik* proihicta obtaineil l>y the dry distillation 



382 ORGANIC CHEMISTRY. 

of these snIisLmres alwaya contain conaiderahle quantities of par- 
affins. TliUH iiiethjine if* a emistf*ut t'onsiitUfnl, in large jirtjpor- 
tion of am] gas* mui of vtoixl gas. Further in tht* dry distillation 
td' shale in ihe 8t'oUisli " paruffiii uil " industry, iM^sidi:** the 
paradins whit h are contiiined in the gaj^eons prmlueU^ the liqui<l 
distillate i'<in?<ist» largely of Uquiil itaraffiiis in whieli solid einii- 
pfiunds, i^l^^J behmgiiig ti) the paraffin SL'rits are helti in wihition. 

Mdhfttk /or ihf prtjifiratum qf /*arff0tii<.— \i uiiiy iKiw cnnven- 
ieutly lie shown that the jiriH'esH diseussed fin pp. 3HtVM87 of 
hiiiltling up, rmni mie memljer *d' the paratlin juries, the next 
hi<i;her niendier, by the re[>laeenient nf a liydrngen atom hy the 
methyl grtiujt, is in eertsdn instanees eapahle nf lutual exjjeri- 
niental realiziition. Tl)is syntHesi.n cuu he efleeted by ^ieveral dif- 
ferertt inetluMlM, an^l one or two uf these niethmls (nay he deserihed 
here witli .sniue detaih 

L < Jne hydrogen atom of methane ean, willniut liithrulty^ 1>e 
replaeed hy tldtirine, methyl ehloride, t'H^n, being jirodueed 
(p. 'ilMJ}. PVoia uietliyl ehloride the eorrejijionding iodine eoui- 
jHiurul (methyl iodide, <.'IIjI) enuld be obt^iined One way to do 
this wtinid be to convert Ibe inytliyl ehloride into methyl aleohol, 
CH.,<)H (p. 418)j ami from this to jirejiare methyl irnhde. It is 
indeed usual to pre[mre na^thyl iodide from methyl alcohol 
(p. 398), hut methyl aleoliol ih pre|»ared on the large t«:4ilo by 
other iiiethodH (p, 418) very miieh more ejisily and eheM[dy than 
would he pos^sibie if it had to be obtained from nu tinuie hy way 
of methyl ehloride. Thin method is stated here, ht^wever, in 
ordrr to »liow I bat the end in view, viz., the pro|*orlion of 
methyl ioditle Ktarting from marsh gaa, itt eiipahie of attain- 
ment. 

If methyl iodide, however prep.ire<l, is dis«rdved in n suitehle 
*iolvent, sueh as ether, and tho H»liiti*in is treated with metallic 
widium, a reaetion takei* place whieh may be diagiumniatically 
reprc<ieuted thus :— 

H H 

I : I 1 

H— C— I 2N» l;-^C— H 

II ■ J i 

H Tl 

The productij are, Bodium iodide (2KaI) aud ethane, 

H IT 

H-}:—0—H. 

I I 
11 H 

and the m«Kk^ of its formation here fhrni«hi?s strong evidence 
coneeraing the ronstitntion of ethane^ 

By carr)dng out n series of operations analogouji to those de- 




PARAFFINS, 

scrihed iii tJie case of rnt timne, uiily **t4irting from ethane instead, 
it is* |K>?v*«ibk' tu [ireimvi' u deriviitivt^ iroiii I his latter hyiirot'ftrlKm 
al«c), iM which ikv [*lm:v uf one Jitimi of hydrngen l» t^ikeii l»y 
iodine m lus to ihrm ettiyl iodide, UJIJ. On tlie jjirge wcrtle ethyl 
iodiile iw, however, fdwiiys prep h red iVoni ethyl ak'<»hol, t*jH,^<llI 
(p. 39H) in the same way that methyl it»djile is pret>iired from 
methyl alcohol. If ethyl iodide is <liH.5o!ved in |iure ether uml the 
fcHihition iM treated with ineUllie ^i<idiiini,a rewetion take^ jilnee which 
i» exactly aiialogoun to that reprent^iited above methyl itxlide : — 
methyl ii»dide ; — 



CH,CH,;I 2Na I;CH,CH,, 



whereby tionnal btitane is prodiired ; while if the <iper:iti*>n is 
.•similarly carried *mt, bnt with the cmjdnynient id' a mixture of 
methyl and rlhyl itidiciivH instead <d' ethyl iodide jilone, besides 
uthane jmd inirnnd buLine (whic:h may Imth be nup posed to l*e 
ftirntcil ueeordin^ Ui the aetiims already represented alKive), a 
(juantity af n third imniHin, jiropane, C^H^,, is alwayH iiruduced. 
The formation of thb paniffln may be represented thuu:^ 

CH^jI 2Na IiCH,CH,. 

Be^ide^ by the method already described for rditiiining normal 
butane froni ethyl indide by the »etlon nf Hudimn, thin paralhn 
can also be [tn pared (mixed, h*>wover, with ethane and normal 
hexime, i\ 11, J. by a method Htrietly aualo^<ms to that just 
Ifiven abfive for the (ire[mration i>f projiane, only cmi>li>yin3< a 
ndxlnre of methyl iodide and normal propyl iodide, C^HIj,* 
itiMtead of the mixture of methyl and ethyl iodidcj^. 

Thu8 by two variations of the same methoil, t.r., by acting with 
Medium (ff) '^*"*^ ^'^^**hm of a Ninjile iodide, and (/>) upon mixed 
Sijlutions of two ditlerent iodides, normal paratlins lari hv obtaini^l 
**itber with even nundn^rs of carbon atoms in their midecules, i»r 
\\\[h odd nunda rs (ti;reatcr than on^-)- ft mut^t Ik? noted, however, 
\\\i\i when iidxcd iodides are eiii[Vbiyed. a mixtureof three diltereut 
paraJhns is always ♦ibtained, as illustrated above, and even the 
approximate sej)aration of these from one another may nc*t ite 
practicable. A reaction of this kind eannol, therefore, be enipli»yed 
8>s a umde for jtri'iniritig a single jmrHflin in a rftnte of tmrity* 

•The iodi<l»*«i are kuowii/botli with molecular weipht eorrt.'^imiidiogto 
the formula I'^HtI. They are called normal and LH>i)ropvl iucILdetii 

H H "11 

H^C^r— 0— I and 

I I I 

UJ H H H 

~6-H roBpectively, 

A 1 L 



And nmv t»c n*|i reseated hv tho formul«i& 
H 11 H 



384 



ORGANIC CHEMISTRY, 



'1. Pamfiiiis are obtained (along with other |>roduct«) by the 
electnilysis of solutions of pcitas^ium «alb* of the homologous senen 
of adds to which acetic acid belongs. These acids are all regiirded 
aa containing a group of atoms which is called the carho£^l group 
and is 8ttpi>o©ed to consist of a carbon atom with its combining 
capacity three- ffnirthi* sjitij^fied by linkage with two oxygen atoms 
(f.*., one-lmlf by litikiige with one oxygen atom which in thereby 
fully s;U!sfied, tiud one-tijurth by linkage with a eectmd oxygen 
atom which^ in turn, h further linked to a hydrogen atom). The 
constitutiou of this group may be represented graphically thus: 

O 

(I 
— € — O — H. To save spaeef however, itia oClen printed— COOH. 

In the acids uf the atvtic seriea (and in carboxyl acid» genemlly) 
the carbon atom of this carboxyl gn.>up is supjM»*e<l to be further 
one-fourth linked to another carbun atom in the mo