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Full text of "Elements of Chemistry: In the Order of the Lectures Given in Yale College"

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I 



THIS BOOK 
FORMS PART OF THE 
ORIGINAL LIBRARY 

OF THE 

UNIVERSITY OF MICHIGAN 

BOUGHT IN EUROPE 

1838 TO 1839 

BY 
ASA CRAY 




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ELEMENTS ' 



CHEMISTRY, 



ORDER OF THE LECTURES GIVEN 



TALE COLLEGE. 



BT BENJAMIir StLLIHAI, 

rKOFZaiOK or CSXKHTKT, rHAKKACT, hii>ek^i.oot akd gkoloot. 



IN TWO VOLUMES. 



HEW HAVEN: 
FRINTED AND PUBLISHED BT BEZBKUH HOWZ. 



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DISTRICT OP COJVJVECTICITT, >*. 

j,,,,,,!^ Bi IT KuiKMaNtsD, That on fl>e eiglitecnifa diy at Fcbruarf In 
I. B, t thefiftf (Mnhyeirof the iDdependence of the Unitad Sutei of Amei^ 
J I iex, HtHJA.Miif aii.hiMA.it, of the nld DiMricI, bttb depodtod In thii 

* —" ■ " office the title of ■ Book, the light whereof he claloii u Author In the 
wordi lbUoirii>|, to wit: 

" Elementi of Chemlitry, in the order of thelectam given in Ytle Colleee. By 
Beiyamln Sillimmn, Prolgaar of Chemiitry, Phumftcy, Wlneralogy end Ueologj. 
In two tdIudim." 

In conlbrmlty to the Act of Congrefi of the United Stitei, entitled, "An Ad lor 
the encoungemcDl aTIeiralQ);, by serurinit the copieeof Mepi, Chirti, end Book*, 
to the euthon utd pniprietara of lucb copies, duriiif; tho timei iberein mGaUoaed." 
And eleo lo the Act, entitled, "An Act EupplementiTy to ui Act, entitled, 'AnAd 
for the eDCDUragement of leaming, by eecuring the ci^le* of Mip>, Charta, and 
Books, to the Authors and Proprietors of nich copiei during the Uniei tberein meo- 
tioned,' and eilending the beoe&lii thereof to the arta of designing, engTaving, and 
Btchluc historical and other prlnta." 

CHARLEB A. INGESSOLL, 

CUrk qflht JMttriet tf Conatctitul. 
A (rue cepT ef Haeoid, examiaed and aeded by me, 

CHARLES A. INOEHSOLL, 

Cttrk iiftht DiMtriet tf O 



OMzcdoyGoOgle 



Tax object of this wrak is to present the science of Chemisliy ia 
the most intelligible form, to those who are leamiog its elements , 
and for the convenience of the classes in Yale College, the topics 
are arranged in the order in which they are now discussed, in the 
lectures given in that Institution. As the Medical Class constitutes a 
part of the audience, the moat important pharmaceutical prepara- 
tions, and leading uses of such substances as belong both to the Ma- 
teria Medica, and to Chemistry, are briefly mentioned ; and in gen- 
eral, throughout the work, practical facts are interwoven with scien- 
tific principles. The attempt has been made, to unite copiousness 
with condensation ; perspicuity with brevity ; and a lucid order, and 
due connexion of subordinate parts, with a general unity of design. 

By numerals* and letters, the topics have been digested under 
appropriate beads ; and by the use of large and small capitals, and 
italics, the writer's impression, as to the relative unportance of the 
leading facts and proportions, has been indicated. 

It is supposed that these mechanical helps, not Dovel Indeed, but 
in this work, more, extensively employed than usual, may facilitate 
the progress of the smdent, by enabling him to take, at pleasure, a 
more general, a more particular, or a detailed review } and the same 
&cill^ is, of course, presented to the instructor. 

Exact accounts of processes and manipulations have been given ^ 
and Dr. Hare, having kbdly permitted the introduction of the cuts,f 
from his Compendium, his own language, sometimes abridged, has 
been general^ emplt^ed in the descriptions of his figures. The val- 
uable illustrations, thus derived from his liberality, render it unne- 
cessary to apoloffxe for the frequent use of his name. 



■ Adopted, to nms siteni, by Dr. p. Bache, in bi« SjKbm of ^nniitry for H«d. 
^ ieal Studcots, kod nan fullf by Dr. HMirj. 

t The more complei figure* have bMn omitted. 



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PREFACE. 



The materials of this work have heen gradually accumulating since 
1803. They have heen drawD from ScieDtiGc Joumab, From the 
Transactions ofLeamed Societies, and from the principal writers who 
Itave flourished since the middle of the last century — the Avguttan 
age of Chemutry. From works of an earlier date, light has been oc- 
canonally derived, as well as from notes and recollections of the in- 
structions of the distmguished teachers, to whom the author was 
formerly so happy as to listen. In this view, he takes particular 
satisfaction in naming the late Dr. Murray, of Edinburgh, and Prof. 
Thomas C. Hope, still a distinguished oroament of the University in 
the same city. 

Various notices, derived from the author's own experience, and 
from his personal communicationa with others, are introduced, with 
occasional figures, for allustrauon ; and in the notes, many miscella- 
neous facts are preserved. 

In the immediate preparation of this work for the press, the oi7gi- 
□al memoirs of authors and discoverers have been often consulted, 
and the abstract has been frequeatly drawn from them, rather than from 
the elementary books ; but ihe analyses contBined in the latter have 
not tinlrequently been adopted ; sometimes even after a careful ex- 
amination of the original, and for this reason, among oihers, that the 
statements contained in them could he often, witliout injury, still 
farther abridged. In such casee, several eminent elementary writers 
have been diligently compared, on the same subject ; and thus 
omis^ons have been supplied, and obscurity has been removed, either 
by the comparison, or by resorting to the first record. 

References to the original memoirs have always been preserved, 
where such memou^ were attainable ; and when the books contain* 
ing them were not at hand, the citations have been copied from the 
latest systematical writers. Credit has also, in most instances, been 
given to elementary writers, for materials drawn from their pages ; 
but for brevity, and especially where the facts are the common 
Stock of the science, the references have been sometimes 'omitted, 
IX an inidal letter only retained. There are, however, some works 
to which a more particular acknowledgment is due. Those of 
Bergman and Scheele ; the Lectures of Dr. Black, by Robison ; 
die System of Dr. Thomson, in all its editions, and also his more 
recent work on the First Principles of Chemtslry j the Dictionaries 

I 



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of Nicbobon, Aikins, and Ure, the Compendiutn of Dr. Hare, ihe 
Dispensatory of Dr. Coxe, the Technology of Dr. Bigelow, the 
Operative Chemist of &ay, and the Chemica) Manipulation of Mr. 
Faraday ; the System of the late Dr. Murray, and his ElemeDts, ably 
edited fay his son ; as also the writings of Mr. Dalton ; the works of 
Lavoisier, Cbaplal, BertboUet, and Fourcroy, the System of Tbenard, 
in its most recent edition, sod his miscellaneous writings, especially 
in connexion with Gay-Lussac ; and those of Dr. Priestley, Ksbop 
Watson, Mr. Parkes, Prof. BerzeUus, and Sir H. Davy, including 
>lso his Elements-~(hese are among the leading authorities, aldiough 
it would be easy to increase the catalogue.* 

A recent work by Dr. Turner, of the Loudon University, his 
been of great utility. It is highly scientific and very exact, particu- 
larly on the facts and doctrines of definite and multiple proptxlions, 
and combining equivalents ; and many of its details have been adopted. 

But the work to which, more than to any other, the author of thig 
is indebted, is the Elements of Dr. Henry. All its numerous edi- 
tions have been attentively studied, and among the facts that bars 
been cited from it, the statements of the proportions of bodies, and 
especially of the salts, are the most prominent. In numerous critical 
comparisons, made between it and the original memoirs, abundant 
evidence has been obtiuned of the great exactness of the respectable 
author, whose abstract always reflects an image of the original, 
dimtuished indeed, but perfect in every feature. No writer on 
chemistry, in the English language, surpasses Dr. Henry in fidelity, 
perspicuity and good judgment. For twenty years, his work was the 
text book of the classes in this Institution, and it ceased to be used 
here only when, on account of its increased size and cost, it ceased 
to be reprinted. Three editionsf of it with notes, were published ex- 
pressly for the students of Yale College ; there bye been three 
English editions since the latest American,^ and the author's eleventh, 
with his last revision, has, through his kindness, been just received. 



* Many French a>well u English JanraalaorSciencc have been >tn> eiamiaeil. 

t Be^es two aubsequenlly, by Proreasora Coie nod Hire, of Ibe Univ. of Penn. 

h Since il haa become difficult b> obtain Ihii nork, the valuable Haunal of Dr. 
Webster, on (he buls of Bnnde, bat baen recommended to Ibe clMses. For 
woriis on Chemistry contain m> much imtwrlant ioformfttioii. 



OMzcdoyGoOgle 



To the foUowiDg gentleineD, the author of this work tenders hii 
acknowledgments; to Prof. Edw&rd Hitchcock and Prof. J. W. 
Webster, who were consulted in the rensal of the earUer proofs ; 
but to Professors Griscom, Torrey and Ohnsted, and to Mr. C. U. 
Shepard, assistant in the chemical department of Yale College, s 
more particular expression of thanks is due, for the trouble which 
they, by request, hare taken, in reading nearly all the proofs. Tbeir 
individual suggestions are occasionally designated ; and while the 
work has been much benefitted by their judicious criticisms, they are 
fuUy exonerated from any respou^biLty either for its eirors, or its 
deficieuces. The errors that have been delected, and which were 
(^ such a character as to afiect the sense, hare been registered, as 
usual, in a table of errata, although the corrections for most of 
them are generally obrious from the context. As other errors will 
doubtless be obserred, the author requests, as a particular favor, 
that they may be promptly communicated to him. 

If it does not excuse, it may account for, some inadveTtencies, 
when it is known, that an arduous and responsible work was written 
and printed, under the unremittmg pressure of absorbing and often 
conflicting duties. Life is 6ying fast away, while, in the hope of 
discharging more perfectly our obligations to our fellow men, we 
wait in vain, for conduued seasons of leisure and repose, in which 
we may refresh and brighten our faculties, and perfect our know- 
ledge. After we are once engaged in the full career of duty, such 
seasons never come ; our powers and our dme are placed in inces- 
sant requisidon ; there is no dischai^e iu our warfare ; and we must 
fight our batdes, not in the circumstances and position which we 
would have chosen, but in those that are forced upon us, by impe- 



T»l« College, ]|30. 



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CX)NTENTS OF VOLUME 1 



Plan of thb wore, - .... | 

Imtrosuction, - . . f 

PART I. — ^Impondkrablb Aoxntb. 

Sec I. — LioHT, '----- 35 

ItB materiality — velocity, - - - - 26 

Its refraction, - - ... 26 

Solar phoaphori, - . - . - 29 

Its chemical agency, - < - - 31 

" action on animalB and vegetableii, - - - 32 

" " " mineral bodies, - - - 33 
" connection with magnetism — sourcea of light — 

Leslie's Photometer, - - - - 34 

Sec. n. — Heat or Caloric, - • - . 35 

General nature, - - - . . " 

Conclneiona, - - - • - ^ 

Effects, - . . . . .44 

1. Expansion, ..... » 

Thermometers, - • - . •54 

SL Distribution of Temperature, • - - 63 

Conduction — Radiation, - - . - 05 

3. Congelation and Liquefaction, - - - 82 

4. Vaporization and Gasification, - . - M 
Steam Engines, - - - • 92 

6. Spontaneons evaporatioD, .... 104 

Eflects— cold, &,c. - - - - 106 

Wollaston's cryophorus, ... HQ 

6. IgnitioD or Incandescence, ... 117 

r. Capacity for Heat— Specific Heat, - - lift 

8. Combustion, ..... \2S 

Sec in. — Affendix to Caloric — Sources of Hbat and 

Cold, ..... 137 

Blowpipe, 128 

Table of freezing miztures, - - • 136 

Sec. IV. — Attraction, ..... 137 

Graritatiott, . - . . . 11 

Magneligm — Galvanism, - • • - 138 

Cohesion and Aggregation. - - 139 

Crystallization, ..... |4] 

Chemical Attraction or Affinity, - 151 

Definite proportions, .... igo 



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Chemical eqiuvalenta. 

Appendix to Attraction, 

Rules of PTiilosspirizing, - 

Apparatus and Operations, 

Specific gravity, method of aBcertuning, 

Pneumatic Cislems, 

Gazometers, 



PART 11. — Ponderable Bodieh. 

Sec. I. — OiTOEN, 

Action on Combustibles, ' 
Relation to animal life. 

Sec II. — NlTROQEN OR AZOTG, 

Atmosphere, - 

Sec III. HVDROOEN, 

Properties, &c. 
IVater — synthesis, - 

" analysis, 

" its properties, 
Deutoxide of Hydrogen, 
Eudiometryby Hydrogen, 

" " spongy Platinum, 

Hare's Oiy-Hydrogen Blowpipe, 



172 
173 
174 
177 
181 
183 



SOS 
907 

ao0 



Preliminary Remarka and Statement, 
Sec I. — Ammonia, . - - - 

Composition, - 
Sec II. — PoTABSA, . - - - 

Properties, 

Uses, dtc. - - - - 

Potassium, 

Decomposition of Potassa aad Soda, 

ProperUes of Potassium, 
Sec III.— Soda, , - - - 

Sodium, . . - 

Sec IV. — LiTHiA, - - - - 

Earths. — ^Introductory Remarka, 



230 
233 
238 
340 



I. — Lime, 
Calcium, 
II. — Baryta, 
Barium, 
III. — Stroktia, 
Strontium. 



.yGcxigle 



CONTKWT*. »« 

IV.— Maonkbia, «« 

HaKDesitim, . . - - - 374 

v.— SiLioA, - ... - - - 274 

Silicon, . . - - - arr 

Glass, *» 

VI. — ^Alumina, . . . - . S88 

Porcelain and Pottery, . . - - 886 

Aliuninium. - - - - - 893 

Vn.— ZiRcoNiA, - . - - • - S86 

Zirconium, ... - - 897 

VIU.— GmciNA, 286 

Glucinium, ----- 3B9 
IX. — Ytteia, .-----" 

Yttrium, 301 

X, — ^Thorina — Thorium, . . - - " 

aiMPLE INFLAMMABLX AND AC1DIFIABLS BOPIKS, (nOt metAlUc,] AMD 
! WITH THE PRXOEDIKO BOSIEi. 



Sec. I. — Hydroorn, {aee p. 301,) - - - 308 

Sec. 11. — Sulphur, , - - . . « 

Acids. — Preliminary Rem&rkB, - - - 306 

General Properties — their nomenclature, • 307 

Sulphuric Acid, .----" 

Sulphurous » 313 

Salts. — Introductory Remark?, - - - 318 

Nomenclature, - - - - 319 

Sulphates of Alkalies &nd Earths, - - 321 

Sulphate of Potassa, - - - - " 

Bi-Bulphate of do. - - - - - 323 

Sulphate of Soda, - - - - 324 

" Ammonia, ... - 335 

" Lime, . . - - 3^8 

Baryta. - - - 328 

Stronlia, . - . - 330 

" Magnesia, . - - - 331 

" Alumina and Alum. - - 334 

Sulphites of Alkalies tind Earths, • - 337 

Sulphite of Lime — of Baryta, . - - » 

" Strontia, Magnesia, Alumina, Potassa, 

Soda, and Ammonia, - - 338 

Hypo-8ulphm«ns Acid, - - • 339 

Hypo-Sulphites, - - ■ . « 

Hypo-Sulphuric Acid and Hypo-Sulphates, - 310 

Sulphuretted Hydrogen, - - - - 341 

Bi-Sulphuretted Do. - - - ■ 344 

Vol. n. 2 



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Hydro-Sulphureis, . . - - 

" ofPoUasB, 

" of Soda, Ammonift, Lime, BkrytiL, 

" of Strontia, Maniesia, 

Sulpbtiretled Hydro-Sulphureta — General ChmBCters, 
ofPetagsa, . . - - - 

of Soda, Amtnonia, Lime, 
of Baryta, Strontia, 
ofMagnenia, 
Sulphoreu of AlkaUea asd AlkaUne EvIIm, 
9m; IIL— Carbon, .... 

Charcoal, - . - - 

UrlCB, . - - - - 

Sulphuret of Carbon, 

C&rbanic Acid, - • " 

Carbonates, 

" ofPotaasa, 

Bi-Carborate of Do. 
Carbonate of Soda, (soda-water) 
Bi-Carbonate of Do. 
Carbonates of Ammonia,' 

■" Baryta, 

" ^TMiti*, 

" Magnesia, 

Carbonic Oxide, - - " 

Carburetted Hydrogen Oases — Olefinnt Goset, 
Naphthaline, . - - - 

Coal and Oil Gaa, - 
Davy's Safety Lamp, 
Cyanogen, . - - 

Pmssic ot Hydr»-Cyanic Acid, 
gu. IV.— Phosprorbs, 

History — preparatio n — prope rtiea, 
Atmoapheric Eudiometer by Phosphonis, 
Phosphoric Acid, - 
Phosphorous Acids, 
Hypo-Phosphoroua Acid, - 
Phosphates, . - - - 

Phosphate and Bi-Pboaphate •( Potassa, 
Mw^hate of Soda, 

" and BL-Pboaphate of Ammonia, 

" of Soda and Anmoni^— of Lime, 

" ofBaiyla, 

■' «f Strontia— of M*g»e8ia, 

" of Ammoraa and Magnena, 



360 
361 



399 
407 

408 



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COMTXHTE. 



Binary Compounds of Phosphorus with yarioua 

Phoaphuretted Hydrogen and varieties, 
Phosphuret of Sulphur, .... 
" Lime, .... 

Sec. V. — NiTROoBN — its Comblnalions with preceding simple 
bodies, ..... 

Nitric Acid, ..... 
Deutoxide of NItrogeir or Klron Gas, 
Nitrous Acids — general explanation, 
Hypo-Nitrous Acid, .... 

Nitrous Acid, . . . • . 

Appenax To Wstoty of (be Nltrow Atild^ 
Nitratca (^Alkaliea, . . - . 

■> PotosM, .... 

" Swto, .... 

** Ammonift, - • - - 

Nitrous Oxids or ProtAxide- i>t ^ittog^a^ 
Nitnte* of tke Ewrtfts, .... 

Baryta, - - - 

•■ Strontia, .... 

" Linic, - • ■ : 

" Hagsena, . - . , 

" Ma^esfs ami AmdoBitt— -of Ahimittft^ 

Nitrites, ..... 

Recapitulation vfCompouDda of Oxygen aaj ^itro- 



463 

460 
467 
469 
461 

4ai 

479 

4eri 



Boracic Acid, 

Bwoo* .... 

Borate of Pctaam— Bi-Boraee of ffoda w ] 

** AMmontft* " Pg f ytt " miNTflttft^ 

" Lime — Magnesia — Almnioa, 

Sec.VH.-FLtioRic Acid, 

Fluo-^Uicic Add Gas, 
Fluo-Boric Acid Gas, - 
Fluoric Principles, 
Fluates — General Characters, - 
Fluate and Bi-Fluate of Potasw, 
" of Soda — of Ammonia, - 
" Baryta — Strontia — ^Lime, 

" Magnesis — Alumina, 

Silica, - - - 

»ec. VIH—Selenivn, .... 
Oxide of Selenium, 
Selenious Acid, 
Selenic Acid, 




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EBRATA — VOL. 1. 



Pus 49,1. Sfr. top, •tier wi(h, del« (hw^Ti ■i>d>Reranolhar,iiMertq^tteMMi«. 
— p. S8, 1. T fr. bot dete ar nMUin^ mois. — p. 118, 1. 15 fr. bot for Uluttrating, read 
Vtuhvted. — p. 139, (g.) tfter Maine, reid and iromint.^p. 148, ]. 19 Tr. top, after 
•cAuA, mid/iaM. — p. lU, L 4&. lop, dele cccfipC llufirtt. — p. 161, 1. S and 4 fr. tra, 
far 40, read T8 ; BDd for 18. retd 40.— p, 162, 1. 7 fr. top, for 1, read 2— p. 168, 1. 10 fr. 
top, after -t- 0.0604 1 8 =, add 1.1S04.— p. 169, 1. 27 fr. lop, before aeid, read oxygen 
^aie.—o. 190, ]. 6 fr. top, for x 18, read +18.— p. 186, 4(t.) before /or, read era.— 

S. aoi, I(a.) after rnuriatu, read onij.— p. 202, 4(c.) for 0.694, reid .0694 ; ai>d p. 
10, 1. 11 fr. bot., ST8, 1. 6 and 6 fr. bot, 403, (£.), 4(«. I. 9 fr. bot Ibe dee. polDt 
ii either ml^Iiced or omitted. — p. 282, (t.) for vitighi 16.17 era., read maght 
ef 100 cut. in. it, 18.17 xra.-^. 241, 1. IB fr. lop, after i)f the. read aihtM t^ 
tAe.— p. 248, 1. 18 fr. top, before patath, read mttatt o/.—p. 262, 1. 17 fr. top, 
•tier 82° for . A read , a. — p. 288, 1. 10 from bot before eotatid, read and. — p. 299, 
(e.) ^n a ftwcoplea,) fornreonia, read nreoniuni. — p. StS, (He.) for -81, read +91. 
— p. 826, 1. 2 ft. lop, iDtercliann 1 and 2. — p. BS2, (i.) dele carbonate ij/I — p. S37, 
1.1 fr. bot for 40, read S2.— p. Sss, I. 11 and 12 from boL for 9 = 108 = 172, reads 
= 72 = 186.— p. 899,1. 16 and 17 fr. top. for 82, read 16 and for 40, read 24.— p. 340, 
I. 4 fr. bot lor 1, read 2; 1. 2A fr. top, for mu, read ie, and vice Term, p. 436, 1. 
le.— p. 866, 2 (a.) 1. 18 fr. top, for it, read ^utrcooL—^. 857, 1. 20 fr. top. for ozide 36, 
raadocidBB. — p. 861,(U.)1.16 fr. top, fori^iriin,read q/'Itme.— p. 371,1. 21 fr. top, 
(n.) for Jtuid, read \ee and omit the paragraph (ij.) — p. 888, bot. 1. after ontt, read in. 
-p. 892,1. 16 fr. top, ioterchange 70 and 80, — p. 899, 1. 17fr. top, after — ■— — - - 

bot dele ni 

489, 1. 10 b. lop, InterdunUB 20 ai 

(T»oI.-p.617, 1. 2irr. t '- ' 



OMzcdoyGoOgle 



PI>AN OF THE WORK. 



1. Iktbodoctort Rxkaaks, on the genera] nature and objects of 
the phyidcal sinences, especially of cbemistiy, and on its connexion 
with the other departments of natural knowledge. 

n. The lHroin>EiuBLE Agents. 

An outUnc of the great powers which produce, influence and mod- 
ify chemical phenomena, exhibiting their nature as far as it is under- 
stood, and their edects as far aa they are ascertained. 
They are treated of in the following cffder— ' 
1. Light, 
3. Heat or caloric, 

3. Galvanism, 

4. Attraction. 

Gahraniam, includbg electrici^ uid magnetism, as far as they are 
-chemical agents, is only sketched in a very general way, in the early 
|>art of the work : the fuller development is reserved lor the conclu- 
aoD, after all the facts of ^ science have been explained, and when, 
Hs the iUustratioDs are drawn &(»n every pan of chemistry, they will 
of course be best understood. 

m. The Ponderable Bobies. 

I. Inoi^arac bodies, including all that do n»t belong to the animal 
and vegetwle kingdoms. 

1 . Oxygen ; one of the bodies that exist m greatest abundance, and 
irtiose AmctioDS and relations are the most important, b first describ- 
ed ; and its properties are ccmiinualfy illustrated in the progress of 
the work. 

I hove not diought it best to describe the simple substances in un- 
interrupted succes^cm. Such a method does not appear to me to 
present advantages, sufficient to compensate for the inccHivenience 
of plung^g, at once, into the most complex parts of the science, 
which must be done, if we would draw the elementary bodies from 
their combinatioas, and present thnn, in the beginning, in a connect- 
ed view. 

For this reason, chlorine with aH its complex relations, and difficult 
theoretical points, in reserved until the student has become familiar 



OMzcdoyCoOgle 



4 PLAN OF THE WORK. 

with numerous import&iit chemical facts, and until those substan- 
ces by whose aid it must be obtained, have been exhibited. It ia 
then easy to revert both to the simple and cwnpound bodies that have 
preceded, and to explain the relations of chlorine to them ; and the 
^milarity between chlorine and oxygen, as supporters of combusticm, 
can then be made even more inteihgible, than in the outset. 

It is obvious, that wherever chlorine may be placed, iodine must 
follow, because of the great similarity in the properties of the two bo- 
dies, and because, alone, iodine would be less mtelligible than chlo- 
rine. Upon this plan also, the origin of iodine from the marine 
plants and other natural sources, admits of more intelligible explaoa- 
tion. The new body bromine, from its 'character and aifinities, nat* 
urally comes in immediately alter chlorine and iodine. It has been 
the practice, of late years, to rank oxygen, chlorine, and iodine to> 
gether, because they have similar electrical and chemical relations : 
and fluorine, a principle which is, as yet, known only in name, has 
been added to the list. .As our evidence of the simplicity of any 
body is merely negative, it is possible that all the bodies now re- 
ceived as simple, may be hereafter decomposed, and every table of 
simple bodies must be regarded as an assumption, founded on the 
negative fact, that those bodies have not yet been decomposed. 

The natural process of acquiring knowledge is the analytical, or 
the progress from the complex to the simple, from the whole to its 
parts ; Uie shortest is the synthetic, that is, from the simple to the 
complex ; from the pans to the whole ; and this is the course now 
more generally pursued in chemistry. If our knowledge were per- 
fect, this would be not only the most obvious, but the best process ; 
and perhaps that mode will be found to combine most advantages 
which unites them both. Widi this view, I have, therefore some- 
times adopted the one and sometimes the other, aiming to present the 
most important elements and combinations as early as pos^le. 

The atmosphere and water are concerned in nearly all chemical 
phenomena. 

2. I have therefore introduced, after oxygen, an account of nitro- 
gen, and tlien, at the next step, the composition and leading mechan- 
ical properties of the atmosphere. 

3. Then follows hydrogen, with the compo^tion and properdes of 
water ; and as a natiu^ appendage, the compound or oxy-nydrc^en 
btowpipe. We are thus early put in possession of this useful and 
splendid instrument.* 

4. Tkt. alkaliet and adds are among the most important of the 
chemical agents, and it is necessary that then- properties should be 



OMzcdoyGoOgle 



PLAN OF THE WOHK. 3 

understood as early as possible. It is perhaps DOt quite obvious 
which siKJuld be first presented to the student. Here, however, as 
well as in every other uraDgenient, it is as desirable, as it is difficult, 
to avoid anticipation : begin where we may, somethiDg must be 
brought into new that has not been explained ; the only proper 
course is, to anticipate as little as possible, and when it is unavoida- 
ble, to ^ve, at the moment, the explanation necessary to render the 
step intelligible ; or to refer to the proper source whence it may be 
obtained. In teaching, I have, with respect to the priority of acids 
and alkalies, tried both methods, and hare concluded, that the alka- 
lies are presented first, with most advantage. The earths, of course, 
follow in the train of the alkalies. 

I have not tliought it advantageous to break up the natural classes 
of alkalies and earths, and place them among the metallic oxides.* 
Strict l(^c would justify, perhaps require such a method ; but the 
convenience of teaching and learning, is in my view, decidedly 
against it ; and there is in fact, no roor^ dif&cuhy in learning the pro- 
perties of potassium and sodium under potassa and soda, than of the 
latter under the former. Still, when the list of the metals is given, 
these two metals and others of a similar character can be included, 
and a proper reference can be made to the places where the de- 
scnpti<Hi of them will be found.f 

In teaching, the great object should be, to Jind our way into the 
mind of the pvpU, and to fir there, the knoi^edge that we present 
to him. He is, ordinarily, no judge of our theoretical views with re- 
gard to classification and arrangement ; he will, in most cases, even fail 
to understand us, when we discuss them ; and he will be best sat- 
isfied, with that course which, in the most interesting and intelligible 
manner, presents to him the greatest amount of usenil knowledge. — 
Both in my public coivses of lectures, and in the present work, I have 
therefore, considered this object as paramount in importance to ev- 
ery other. , 

5. The tisii^le, nottrm^aBw eombiatible bodies are next intro- 
duced, both b^use their history is remarkably interesting and in- 
structive, and because they are the bases of the most important acids, 
whose history is easily and naturally developed, in connexion with 
that of these combustibles. Hydrogen, ^eady described along 
with water, comes again into view as the basis of muriatic acid. 
rTitrogen,! although, in a popular sense, strictly a non-combusdble ; 

* Since Iha metilUc ozidei Incluile bodies of meh widely dlfiarent propertiei, I 
c«i Me OD Inpnpriety Id diftrilnitiiif Ibem Into cluws. I im. nipporied in thii ar- 
ranpMneDlby the l»l«»dldMiof Hamy. 

I The sew Mnfoile alkallcM prindpfea are m pecuIiRr in moat of their propertio, 
ibW there would be no idvantage in clManf; Ihcm nllh the alkallei commoiily w 

t A1«D I>«lbre described in connexion wIOi the history of the itmoiiphere. 



D,q,fzodbyGo(lg[e 



4 I^AN or THE WOSE. 

Still, because it possesses affinities, and [Hoduces in combiiutkn, ■»• 
suits entirely dmilar to those of the combustibles, is thrown into the 
same class, for the purpose of bringing forward the important acids 
and oxides of which it is the basis. 

Two of the least important of the simple combuBOUes, boron and 
selenium, ore reserved until this period : their history bears no very 
important relaticMi to that of most of the other bodies, but, as ibe^ loo 
form acids, they are disposed of in the tram of the other combustibles, 
and of the great agents that sustain combustion. 

Fluoric acid, which although undecomposed, has without doubt, a 
combustible base, is naturally assigned to the same place, in the class- 
ification, and from its combining, m an interesting manner, with boron, 
it comes immediately after that body, and before selenium, whose 
character is rather anomalous, but more allied perhaps to the combus- 
tibles than to the metals, where many have placed it. 

6. CfUorine and Iodine and Bromine are introduced after the ele- 
mentary non-metallic combustibles have been described, and at a pe- 
riod when, as already inumated, their history becomes intelligible. 

The history of bodies, thus far described, embraces a great part 
of the philosophy of chemistry, and no small part of the most im- 
portant (acts of the science. If we were to name any portion of 
chemistry, that is more splendid in its experiments, and more afflu- 
ent in important results, than another, it would be that which is in- 
cluded in the history of the elementary combustible bodies, especial- 
ly when we add their relation to chlorine and iodine, which foUcmr im- 
mediately after the simple inflammables. 

7. The metals come next, and their history includes aO the re- 
maining elementary bodies. There is a general agreement among 
authOTS, as (o the place which most of the metals are to occupy in a 
systematic arrangement, and no one at present thinks of presenting 
ihem, aa some formeriy did, m the beginning, along widi other ele- 
mentary bodies. It^s true that some of them are used in the de- 
monstrations tliat precede, but as most of the facts are familiar, and 
the phenomena intelligible, this creates no difficulty ; every one cao 
understand, for instance, how iron decomposes water, and he will 
comprehend how sulphuric acid aids in that process, just as well be- 
fore as after he has studied the properties of iron and of the other 
metals. 

11. Oboanic Bodies. 

They owe their particular niodes of existence, to the jomt actioiL 
of the laws of life and of mauer. 

There is, of course, nothing elementary in this part of the subject. 
Botli animals and plants must derive their elements from the unor- 



OMzcdoyGoOgle 



PLAN OF THE WOBK. A 

gamzed kingdom ; and, in reladon to them, our most intareating 
task is, to trace the various proximate {xinciples, in which the ele- 
mentB aie combined. This part of chemistry is lem splendid than 
the |H«ceding ; but it is thih^l in important infoimatitKi, and much 
of it is applicable to common mmu and occurrences. 

1. Vegttahle Bodiu. 

We bav« here «iily oxygen, carbc», and bvdrogen, as essential to 
the contotmion of most plants ; nitrogen ii found in some, and the 
number containing it is greater than was fwmerly sippoaed ; but 
the proximate principles are numerous and important, and ibe sbident 
is astonished to find, that such diversified results are obtained fmm the 
union, in difierent modes and prop(nlionB, of three or lour elements. 

' 2. Animal Bodies. ' 

The few remarks, just made, are applicable here with some quali- 
fications. 

The same elements are found as in vegetables ; and nitroeen, 
instead of being an occadonal, is nearly a constant principle. Tlie 
number of proximate prindples is however more limited tban in the 
vegetable kingdom, but their history is instructiTe and important. 

All are agreed in giving a late |>lace to the cbemistiy of organ- 
ized bodies ; for it is obvious, that it would not be intemgible at an 
earher period. 



It has been already stated, that this power, although mentioned 
and described, generally, among the imponderable agents, is better 
understood, after the student has been made acquainted with all the 
other facts in chemistry. 

As a general power, its most important fiinction is, in the decom- 
position of bodies, ending m the transfer of their elements and prin- 
ciples, to its respective jpoles. This bemg, m the begining, ex- 
plained, and experimentally proved, in connexion with the history of 
the other imponderable agents, there is no difficulty in markii:^ and 
understandii^ tbe polariQ' of each body as we proceed, and when 
we come to present Galvamsm, in form and m ftdness, aX the end 
of the course, thislgeneral arrangement of both elements and prox- 
imate principles can be recapitulated, and experimenlally illustrated 
in detail, with great advantage. 



DMz.d.,Goog[e 



8 INTRODUCTION. 

and angular measuremeDts of per^iective, and of navigatkni, surrey* 
ing and astranomy, are among its most familiar and obvious ap- 
plicadoos. 

To return to Natural Philosophvt the student in this science learns, 
widi pleasure and surprise, that the same power which retains Jupi- 
ter m his orbit, precipitates a falling drop ; that a feather, a balloon 
and a ship of the line are floated by statical pressure ; that the same 
power causes a narrow column of water, sustained in a tube, to raise 
a weight, many thousand times greater than its own ; thai by its 
means a cascade falls through die atmosphere, which in its tuni, 
raises a column of water in a pump ; and that gravity exerts an 
uninterrupted dominion over atoms, planets and systems. It is seen 
also by the learner, that the mechamcal powers, so indispensable to 
our existence and efficiency, and that the motions of animals are de- 
pendent upon similar principles, and gravity is not unfrequendy tlie 
munediate aguit. 

The phenomena of uqbt are among the most beaudful and in- 
structive of those belonging to Natural Philosc^hy. The rEunbow 
is a splendid example of the decomposition of the solar beam, ef- 
fected by the refractive power of the drops of water ; stJU, magnifi- 
cent and beautiful as it is, it excites perhaps less astonishment in 
the beholder, than the colors exhibited by the common prism in a 
darkened room, where the iris, although very small, compared with 
the bow, is more intense, and is brought within our more immediate 
view. The astonishing results produced by the solar focus, in which 
the concentrated beams melt and dissipate metals and stones ; the 
surprising and beautiful effects of the common, the lucemal, and 
the solar microscope, in whose fields of viaon motes become beams, 
and animalculffi rival the gigantic animals ; the wonderful illustratioiis 
of the eye, on whose retina, either uncovered by dissection, or imi- 
Uted by art, are seen painted distinctly, in all their varieties of color 
and of form, the fields, the groves, the sky, tlie faces of men, and aU 
the objects that surround us ; the power of the telescope, by whiclj 
we penetrate into the awful darkness of space, and look through the 
-veil that covers the heavenly bodies ; these are a few of the won- 
ders which natural jihilosophy teaches respecting light, that incom- 
prehensible emanauon, without which the creation would become 
cheerless and desolate, and animated beings would dwindle and die. 

The atmosphere, in tranquillity, is hole regarded except as af- 
fording the means of comfortable respiratitn to the whole animal 
world ; but, disturbed in Ms statical pressure, by the influence of 
heat. It generates not only land and sea breezes, monsoons, and trade 
winds, but the hurricane and the tornado. Navies are overwfaehned 
in the waves ; the oak and the cedar are prostrated ; and man and 
his works, his towers of strength, and his pimiBcles of pride areJevel- 



OMzcdoyGoOgle 



INTBODUCTIOrr. ,ft 

M with the dust The seme atmosphere, alihou^i invariably the 
readence of the electric fluid, exhibita, only occesionaUy, decisive 
proof of an energy, which pervades the material world. Excited 
by causes, which, except in their prosimate operation, are unknown 
to us, the electric fluid fills the atmosphere with thunder and light- 
ning. It was reserved for Dr. Franklin to prove, that lightning is 
identical mth the sparks which are obtained by friction from glass 
or resin, or from dry fur, from our apparel of silk or woollen, and 
from many other sources. In short, we now know that all things are 
tull of the electrical influence ; that we can bring it down &om the 
clouds by kites, metallic rods and wires ; that we can evolve it by our 
machines of glass and metals, and that by the power called Galvan- 
ism, using certain arrangements of metals, acids, and other substances, 
we can produce it at pleasure, connected more or less mth the other 
imponderable fluids, m entire independence of tlie weather, and of 
the state of the atmosphere ; and at the same time we can render 
sensible the attraction and repulsion, which are inseparable from its 
excitement. 

Although the experiments, exhibiting these facts, are sufficiendy 
curious, the importance of the su^ect has, only within a few years, 
been perceived in its full extern ; for it b now believed, that the par- 
ticles of maoer are constantly under the influence of these attractions 
and repulsions, and that they are producing, without cessation, de- 
compositions and new arrangements. 

Associated, every where, with electricity, heat both modifies its 
effects, and produces peculiar phenomena. The mild radiations of 
the sun, and the genue fluctuatnns of temperature are su^ects of 
commtHi ^ipenence, and excite no particular surprise. But the 
ama^ng energy of volcanic action, far surpasses every other ex- 
ample of natural heat. Sci^ce is now in a condition to reason, with 
coosiderabie wob^iEty, as to the causes of volcanic boat, and stitl 
more, regardmg those of the accompanying phenomena of earth- 
quakes : out leaving these for the present out of view, our attention 
is arrested by the grandeur of the events, associated widi volcanic 
agency. 

The convulson of the ground, not only in the immediate vicini^, 
but often in distant countries j the subterranean noises, like internal 
thunder, and the grating sound produced by the rendbg of the solid 
strata ; the violent emission nf gases, steam, ashes, sand, ignited 
stones and rocks, and eventually of the current of lava, which flows 
in a stream of fire down the mountain, and over the nether country; 
the overthrow of the structures of man, or dieir inhumanon beneath 
the lava and ashes ; the lightning and thunder, in and above the cra- 
ter ; the violent flux and reflux of the tides and the strong agita- 
lion of the Fiea, akemately inundating and draining the adjacent 



OMzcdoyGoOglC 



10 INTRODUCTION. 

shores ; the deluging torrents of i^n and mud, and the delusive pe- 
nods of repose, between the eruptions, sometimes extending U> years, 
and centuries, are among the principal circumstances which charac- 
terise volcanos. 

Attraction and kcpulsion, although less obvious than some of 
those phenomena that have been mentioned, are undoubtedly, tnore 
important in relation to the system of things, than any or all other 
natural causes and events. 

Gravitation is the bmitl which connects, equally, the greatest and 
the minutest parts of our system. Every particle of matter gravi- 
tates towards every other ; every mass, however large, is attracted 
by every particle j every member of our ^stem, and every sys- 
tem, in the great system of systems is a£fected, reciprocally, by 
every other ; projectile power, or immense distance and counter- 
balancing attractions keep them from rushing together in ruinous col- 
li»on ; and the whole creation of matter is afloat in space, suspend- 
ed and sustained by the energy of almighty power. 

It would be foreign to our present puipose, to designate the de- 
taHs of the various kinds of atuaction— the gravitating, the electri- 
cal, the cohesive, the chemical, and the magnetic. 

The magnetic is universally known, and ^ its aid we traverse ths 
ocean and pathless deserts. It presents the most striking and famil- 
iar example of repulsion, a power, which, springing from various 
causes, aiid operating under various forms, is, although unseen, every 
where active around us. We do not certainly know, that magne- 
tism can be permanently attached to any other substances than iroo 
and nickel,* although we can no longer entertain a doubt, that it 
holds a permanent connexion with heat, light and electricity. 

Attraction is only a name for an unknown cause, of which we have 
no other knowledge than that it depends on the will of God. Mys- 
terious indeed it is, but it is not more so than the coimexion of our 
intelligent miuds with our Uving bodies. The Creator can endue mat- 
ter with any properties, and diere are, undoubtedly, many pos^le 
quaUties, which he has not bestowed, and many actual tmes, which 
we have not discovered. 

Astronokt examines the heavenly bodies, and the construction and 
relations of the celestial systems. It has Uught us that the diffiise light 
of the Galaxy is composed of the mingled eSiilgence of innumerable 
stars, each of which is, probably, the centre of a system, and the coq- 
tinually mcreasing power of ptnetrating into tpace, acquired by the 
modem improvements of the telescope, evinces, diat we have only 
begun to number the stars, and that we shall never bd able to ctti) 



* Some (dd c^ilL 



OMzcdoyGoOglC 



INTRODUCTION. jj 

them all by their names. But we have measured the distances and 
the dimensicHis of the planets and the periods and the rapidiiy of 
their revolutiOas ; and we have ascertained their absolute ana relative 
weight. We know not where discovery will stop ; the nobie science 
of astnxKtmy is now cultivated with an ardor not surpassed even by 
that of the age of Newton, and with means far superior. Innumera- 
ble discoveries of new stars have been made ; and it is ascertained, 
that a part of the fixed stars have a revolution indicating the move- 
ments of the members of particular systems. This is true, especial- 
ly of what are called the double stars, and the sublime conception 
is entertained, that the whole steUary ^stem, with its myriads of 
planetary worlds, revolves in the course of ages around a common 
centre. 

Astronomy is, not without reason, regarded, by mankind, as the 
sublimest of the natural sciences. Its objects, so frequently viable, 
and therefore famihar, being always remote and inaccesfflble, do not 
lose their dimity. 

Although Newton, a century ago, unfolded the structure of the 
universe ; Herschel, La Place, La Lande, and other distmguished 
astronomers have condnued to enlarge our knowledge of the heavens* 
and the Astronomical Society of London dthgently collects and com- 
pares all discoveries, while some of its members are ardently engaged 
in makuig new observations. 

The practical applications of astronomy, in determining the latitude 
and longitude especially at sea, are highly important ; the exact cal- 
culation and prediction of some of its more striking phenomena have 
removed the superstitious dread of eclipses, and substituted a rational 
comprehension of their cause ; while the transits of the planets and 
the measurement of arcs of great circles of the heavens in difierent 
latitudes, have been thought sufficiently important to justify voyages 
and journeys to the most distant and inhospitable regions. It may be 
mentioned also, without impropnety, that the observatioa of theheaven- 
lybodies is a rational source of amusement. In a fine night, the teles- 
cope, although not like that of Herschel, of immoderate aze and ex- 
pense, is an interesting companion, and we conteniplate with delight the 
mild histre of the evenuig star, the fien' hce of Mars, the alver orb of 
Jupiter, his behs and his satellites, and the incomprehensible i^gs of 
Satum.-)- 



1 Id thli conneXHHi wa ought aot to tai^t Dollood, LercttoBra, Fraunhoror mi 
othar diitlDgaUMd tntati wlUioal whow ild the Kwnca of utrackaiiiy miul hivp 
becit vrMted U ita coaTM. 



OMzcdoyGoOgle 



12 INTHODOCTION. 

3. Natural histori describes the external appearance or at 
least the distinctive characters of all natural bodies. Its nunwrouS 
sub-divisions, are all included under Zoology, ftHneralogy and Botany. 

Zooi.oor, which includes the whole animal world, comprehends 
also a great number of subdivisions, e. g. omitholt^, ichthyology, 
herpetokgy, entomology, concltologj', &c. As it is conversant about 
animated beings, it inquires also into their habits, their food, their re- 
production, their decay and their death. Strictly, man is at the head 
of this department of Natural History. Zoology bepns with maa 
and ends with the snail and ilie oyster ; and in its course it embraces 
the elephant and the mouse, the lion and the mole, the whale and 
the minim, the eagle and ilic gnat. 

Ai^on^ gigantic animals, the whale, the larger seals, the rlitnoce- 
ro9, the hippopotamus, the wild buffalo, the giraHe, the camel and 
the elephant, are signal examples, and among the reptilia, the boa 
constrictor and the anaconda are sometimes of enormous size. In 
zoology, living animals are of course more interesting and more in- 
structive subjects of study dian dead ones, however well preserved. 

A menagerie, is one of the most gratifying kinds of museums, and 
these exhibitJons, as regards especially die larger and more perfect 
wild animals, affiird very fine opportunities for the study of zoology. 
The panthers and the elks of America, the rein deer of Lapland, 
the lions, the camelopards and the zebras of Africa, and the royal 
t^rs, the hyenas and the elephants of Asia, torn from their native 
fwests and dens, are impriscned not only in the apartments of Exe- 
ter 'Change, of the Tower of London, and of the Garden of Plants 
of Paris, out in the cages of the travelling caravans which have now 
become common in this country. 

But, where all opportunities from museums, whether of dead or 
living animals, are wanting, zoology may still be studied, with good 
advantage, by the aid of the numerous works on this science, illus- 
trated 05 most of them are by accurate engravings. 

MiireRAU)aT and geolooy comprise all that relates to the mineral 
constitution of our planet, including its atmosphere and various gases, 
as well as its waters, its metals, its salts, its combusbbles, and its earthy 
combinations. The study embraces not only mountains and conti- 
nents, but the pebbles under our feet, the sand on the shores and 
the dust ^at is borne on the vrinds. It attempts to account for die 
origin and causes of the present slate of things, and it contemplates 
the impending changes, decay and dissolution of the firm substratum 
of our globe. Minerals, although to some extent constandy before 
lis, are, for the greater part, far more inaccessible than vegetables 
and animals. Many of them are drawn from the recesses of the 
earth, from the caverns and mines remote from the lieht of day.— 
In this department then, although sqmpthinj^ may bp none with the 



DK;,lz=..,C00g[e 



INTRODUCTION. 13 

Hid of such things as we can every where obaia, still, a cabinet or 
museum is pecuuarly necessary, and as this study is aclmowledged 
to be both important and interesting, collections io mineralogy are 
found in colleges and universties more generally than any other sub- 
jects of natural history. They have the very important advantage 
of bemg, with few esceptiona, not liable to destruction, nor lo any 
spontaneous changes. They need no preparation, but when detach- 
ed from their native situatknis, and reduced to a proper size, are 
ready Ua the museum. This department of nature affiirds much of 
the wealth of natjcms, many of the comforts of civilized and poUshed 
society, nearly all the instruments of physical and philosophical re- 
search, and most of those of the ornamental and useful arts. Civili- 
zation, social refinement and science cannot exist where the mine- 
ral kingdom is not explored and understood, and especially where 
iitHi and some of the other metals are not known and used. 

Although no aliment for living beings is obtained from tlus king- 
dom, very important remedies are derived from it, especially from 
several of the earths and metals. Plants and animals are probably 
more attractive to the eyes of most persons than the greater part 
of minerak ; still, among crystals are found objects of extreme 
beauty, whose polish and whose fram rival the finest wwks of art, 
and some of the gems have ev^r been selected to adorn diadems 
and crowns. 

Gboloqy, which reveals to us the actual structure of the globe, 
and the natural portion, relation and associatirms of its productions, 
afibrds important light in the research for useliil minerals ; and it ex- 
hibits, in the arrangement and c<Mitrivance of the mineral strata, de- 
cisive proofs of the power, wisdom and deagn of its author. 

Botany is the namral history of plants. It is a beaudfiil and em- 
inently usefid branch of knowledge. It is constantly extending its re- 
searches and adding new species to the great number,* whidi have 
been already discovered. 

The loftiest forest tree and the humblest shrub are equally within 
its domam, and every climate, and every contment and island, are 
visited for the discovery of new species. The plants that grow in 
mountains indicate, with great accuracy, the climates that bekmg to 
the diflerent elevations ; die plants and fruits of tropical repons may 
grow at the foot, and the stunted evergreens of the polar circle may 
crown the summit. 

In this elegant department of knowledge, a sufficient number of its 
subjects is scattered every where around us, to afibrd the means of 
comprehending the outlines of the science and of prosecuting it with 



* Tifty-rix tbMiMod, or more. 



D„tiidD,Googlc 



14 INTRODUCTION. 

considerable advuiuge. Its dried specimens are preserved with in- 
comparably more ease than those of animals, and ii is thought to be an 
object worthy even of princely muhiticence to found collectioni of 
Uving plants, and to preserve them in the BotanicaJ Gardens, as is 
seen in the Royal establishment of Kew in England, and of the Gar- 
den of Plants in Paris. Even public spirited individuals* have, either 
by their own effiirts, or by the assistance of private citizens, Uke them- 
selves, fonned botanical gardens, of ^gnal beau^ and utility ; pre- 
senting in one grand perspective, the vegetable glories of the world. 
The study of the science is thus facilitated, b a surprising degree, 
and the botanical student finds, within the bounds of at most a few 
acres, die plants, to have seen which, in their native smls, would have 
demanded a life of adventure. The vegetable kingdom affi)rds most 
of the food of men and animals, many medicines, and many materials 
for the arts. 

3. Chehistbt. — The remaining branch of science relating to nat- 
ural bodies, begins where Natural Philosophy and Namral History 
stop. As the gleanings of its early history may be found in the pre- 
faces of the larger elementary works on chemistry, we shall here omit 
the vague annds of its intancy, and the delusions of its middle age. 

It would exceed our limits to trace the progress of chemistry 
from age to age ; to unfold the delusions of alchemy, whose ob- 
ject was to discover the philosopher's stone, an imaginary substance, 
iritich, it was supposed, would convert the baser metals into gold 
and «lver ; or, to speak of the equally delusive pursuit, alter the 
ORAND CATHOLicoN, or universal remedy, which was to remove eve- 
ry disease ; lo avert death, and confer terrestrial immortality upon 
man ; or to mention the imaginary alcahest, or universal solvent, 
whose power it was supposed nothing could resist. The alchem- 
ist indeed imagined, that these miraculous virtues resided in one 
and the some substance, and during the dark ages, most of the cul- 
dvators of what was then called chemistry, sminen with the deli- 
rium of alchemy, pursued their occuh processes, in cells and caverns, 
remote from the light of heaven, and wasted their daj^i fuid nights, 
their talents and meir fortunes, in a vain pursuit. The alchemist 
however accumulated many valuable facts, which have been em- 
ployed, with good advantage, in laying the foundations of modem 
cberojcal science. 

Some knowledge of chemical arts is coeval with the earliest stages 
of human society, and it has happened with this, as with other branch- 
es of natural knowledge, that many facts were discovered, and accu- 



OMzcdoyGoOgle 



INTRODUCTION. 



Id 



mulated, in the practice of the arts, and in domestic economy, ItMig 
before aoy general truths were established, by a course of iaatictiTO 
reasoning, upon the phenomena. 

The arts are all either mechanical or chemical, and not uofrequent- 
ly both are involved in the same processes. The practices a the 
arts may be reearded as experiments in imtur^ philosophy and chem- 
isby. The object of the anist is usually gain ; but he, or any other 
person, who views the facts correctly, may reason upon them advan- 
tageously, and thus obtain important instruction. 

Glass b a chemical compound, usually of nliceous earth and fixed 
alkali, or in a more extended view, of dkaline, saline, metallic and 
earthy materials. These, after being duly proportioned, are com- 
bined by the eSect of fire, and various adventitious matters are added, 
to impart color or to discharge it, to increase the density, or to dimin' 
isb the hardness, or for various other purposes. 

The producti(Mi of the materials of the glass depends therefore 
upon chemical principles, and is thus far, a chemical an. But, the 
fabrication of the vessels depends upon mechanical causes, principtJly 
the breath of the anist, injected tltfougb an iron tube, to which the 
melted glass is made to adnere. The subsequent cutdng, grinding, 
and poh^iing of the glass are also mechanical, and thus glass is a 
production both of chemistry and mechanism. 

Soap, (except the mere act of mingling the oil and the alkali,} is a 
production of chemistry alone ; a watch is a resuk of mechanism, but 
the metals of which it is made are prepared bv chemistry and me- 
chanism united ; wool is carded, spun, woven, iuUed and beared by 
mechanical means, but it is scoured and dyed by chemical processes, 
and thus through a multitude of instances, the purposes of socie^ are 
accomplished, by the amplication of the principles of one or of the 
other, or of both of these sciences. 

The idence of chemistry considered as a collection of elementary 
truths derived from the study of facts, can scarcely be referred to a pe> 
riod much beyond the commencement of the last century, and its prin- 
cipal triumphs have been achieved, smce the middle of that period. 
It would be premature, to detail, on the present occasion, the partic- 
ular discoveries, which, like stars, rising successively, above the h<»- 
izon, have broken forth in rapid succession. Iliose discoveries, their 
periods and authors will be mentioned, m giving the history of each 
particular substance. At present, it would not be proper to attempt 
any thing more than to convey to those to whom the subject mc^ be 
new, a general conception of the nature, extent and objects of the 
s<»ence of chemistry, reserving the details for the time when tfaey 
nil] be both the most intelligible and the most interesdng. 



OMzcdoyGoOgle 



16 INTBODUOTION. 

DkTINITION.* — CBKHI8TBT 18 THAT SCIENCE WHICH IWFKBTl- 
OATKS THE COMPOSITION OF AU. BODIES, AND THE lAWS BT WHICH 
IT IS aOTXBMED. 

Remark.— TkU, of covne, indvda every jpomWe etmiination 
and decompotition. 

ChemisOy, taking into view the properties discovered by NaturM 
Philosophjr, be^ns its appropriate worit where the aster sdence nops. 

The distiDCtioD between chemistry and natural phiknopby is illus-^ 
(rated by the familiar examples of 

1. Water, 

3. Theatmotphere, 

3. OvnpmDMT. 

Thus, water is composed of the bases of two gases ; the air of al 
least two, and gunpowder of combustible and metallic matter and the 
ponderable ^rt of gases. 

JVatural J&tory, JViUural PhiJoiophy and Chmutry are all ne- 
cessary to complete the scientific lustory of any thing. 

JVoftwaZ Kwtory explains the external qipearance of bodies ; 

J^aiwal Pkiiotopky the mechanical properties ; 

Chemittry the constitution. 

This general position is easily illustrated l^y reference to anAer, 
tool, cak-spar,fo>iS laU, and other familiar bodies. 

Chemistry is distingui^ied as an art or a collectitw of arts, &om 
ehenattry as a science: the former is empirical, the latter is guided 
by established principles, and they are now, in numerous instances, 
happily united, m the hands of both pracdcal and scientific men. 

Chemical arts are numerous ; guut and loap-maki^, hare been 
already meodooed, and pottery, metailui^, and dyeing, may be ad- 
ded ; the latter depends on the affinity of coloring matter for fibre, 
or for the mordant, or for both. 

The vinous fermentation produces cider, wine, perry, bear, me- 
theglin, &ic. Carbonic acid gas is evolved, while alcohol is formed, 
and the rapidly of the process depends on the temperature. 

Leather, is formed fi^im skins and tannin contained in the astrin- 
" gent vegetables') the tannin of the latter uniting with the gelatine of 
the skin. 

Bread, is produced by a peculiar fermentation : its sourness, ow- 
ing to excessive fermentation, is corrected by an alkali and the carbon- 
ic acid which is evolved, renders it h^ter than before. 



Fearcroy, Henrj, Murray, L> Grange, 1 



OMzcdoyGoOgle 



INTHODUCTION. 17 

Mc; the theoiy of its fonnation is, that the astringent piiociple 
unites with the oxide of iron, and gum Arabic or sugar suspends the 
precipitate. 

The bunting of lime consists in the expulsion of the carbonic acid, 
bj heat ; the acid gas forms nearly one half of the weight of the 
liinestiHie, marble, and chalk. 

Art and laence mutually aid each other, because art furnishes 
Jiands and science eyes ; science without art is inefficient ; art with- 
out science is blind. 

The philosophica] chemist must understand the pnndpU* of the 
Ghsmical arts, and the more of the practice he knows the better. 

Chsmical artists ^ould understand the science, at least of their own 
ana, and practical knowledge is of course indispensable. 

Not satisfied with the knowledge of the external properties and the 
mechanical relatkms, which are unfolded by Natural History and by 
I^ysics, but taking them into view, and retaining and using their 
principal discoreries, chemistry proceeds to investigate the hidden 
constitiiliati of every species of material existence, in earth, sea and 
air. 

Earth, air, fire and water, were the four elements of the ancient 
school. They have however, yielded to analysis, and water, Uand 
and simple as it seems, contains two bodies, whose properties, are en- 
tirely di&rent from its own and from those of each other ; burning, 
Vhen mingled and ignited in large quantities, with violent explo- 
^on ; and in a small ^eam, with a heat, which melts and dissipates 
the firmest substances. We should never have conjectured that 
water, whose great pren^tive it is, to extinguisli fire, c(»itains 
both a combustible and a supp<Hler of combustion. 

The mr, the pabulum of life to the whole animal and vegetable 
creatioB, mild and negative like water, is not limple but contains inci- 
dentally many bodies, — essentially however only two ; one of which 
and that, constituting four fifths of the whole, is, and was intended to 
be, in a high degree noxious and even deadly to animal life and fatal 
to c(»nbustion. The air does not destroy life instead of invigorating 
our frames, and extinguish instead of inflaming combustion, because 
the prevalent noxious principle of the air (nilrcwen) is balanced by a 
life and fire-sustaining principle (oxygen) too vigorous to be tni^ed 
alone, and dierefore, diluted exacdy to the proper degree, by the op- 
podte [Hinciple, both being, by another extraordinary provision, sus- 
tained, in constant proportion, and thus producing a sbIuIhious and 
unchan^g atmosphere. 

7%e earth, under our feet, the soil, the sand, the gravel, the firm 
substance of the rocks, is not dmple. b this ancient but assumed 
element, we have a double complexness. Hie one imagined, simple 



OMzcdoyGoOgle 



19 INTRODUCTION. 

efirth contains at least nine, and each of these is again complex, con- 
taining for one piinciple, oxygen, tbe same that exists both in wa- 
ter and in the atmosphere, united to nine or ten varieties of raet- 
ak or combustibles none of which are known in common life. 

He who is acquabted with the wonderfiil effects of chemical com- 
Innation, will not think it strange that half the weight of marUe is 
carbonic acid, and that metals, when combined with oxygen, resemUe, 
very exactly, the earthy substances. 

Ltg-Af 05 ukU at heat, is contained in common fire, and therefore 
it is not simple, unless fire and heat are vaiieties of one and the same 
thing. 

Modem research has proved that, besides light, which in its 
seven prismadc cokirs, is contained in the solar beam, there is also, 
in this emanation, an opake, radiant principle, which accompanying 
light and heat, neither warms nor illuminates, but acts to decompose 
certain chemical compounds; that there are opake rays which wann 
but do not illuminate, and illuminating rays which are cold to the 
sense of living animals, but impart to the universe its splendid drape* 
TV of colors; and that, associated with one or more of these emana- 
tions, there is a surprising power, which imparEs magneusm to a needle, 
and gives it the properdes of the loadstone. But we have used the 
word element without de&uog it. 

^n elsTnent u an andecompomble body — it is therefore simple, or 
in other w(»ds not reducible to any other form of existence. We 
must however, carefully distinguish, between real elements, and those 
which are such, only in reladon to the present state of our knowledge. 
When modem science speaks of a body as elementary, it intends 
nothing more, tlian that it has not been decomposed. It is therefore 
^mple as far as we know, but it is possible that, by fiiture efTorts, it 
may he decomposed. Ahhough wc have no reason to doubt, that 
there are re(d elements, we cannot say, that we are certainly in pos- 
sesion t^ any one element. It is, however, perfecdy safe to 
reason upon bodies as elementary, until they arc proved to be 
compound. Iron is, as far as we know, a simple body ; we cannot 
Bs yet, exhibit it in any simpler form ; all we can do, is to aher 
its figure' and azc, wiUiout at all changing its nature. But iron 
rust, or the scales which fly <^ irfien red hot iron is hammered, are 
not simple ; they consist of iron, combined with oxygon, one of the 
principles of the atmosphere ; ive can cxliibit these Nubstances in a 
simpler form ; tlie iron, which they contain can be separated from 
the aerial principle, and both can be exhibited apart, and thus the 
proof will be complete ; red lead and red precipitate are still better 
exampleE, because the former can be psruaJly, and the latter whtdly. 
brought back to the condition of metals, by simply heating them. 



OMzcdoyGoOgle 



IWTBObUCTlON. 19 

The four ancient elements, earth, air, fire and water, were assum- 
ed at hazard, because they are so conspicuous and important ; the 
ccHiception was grand but it was wholly erroneous. 

Instead of four elements, we have at the present time not less 
than fifty, nearly four fifths of which are metals ; the remainder 
are chiefly combustibleE, and bodies, which, combining with com- 
bustibles and metals with pecuUar energy, are generally called support- 
ers of combustion.* 

Our simple bodies then are 

1. Metals, about ... 404- 

2. Combustibles not metallic, - - Tj 

3. Prmciples or supporters of ctHsbustioo, - 3 or 3 

4. One b<>dy,orpossiblytwo|of an undetertmned char- 
acter ; in all - - - - - 50 or 51 

5. Imponderable bodies, light, heat and electricity ; besides the 
power called magnetism and. the other variecea of attraction. 

The principal object of chemistry is to display first, the great 
powers upon which its phenomena depend ; and secondly, the proper- 
ties of the elements, the mode and energy of their action, the combi- 
nations which they are capable of forming, the properties of the result- 
ing compounds, and the laws by winch they are governed. This 
Statement, obviously, includes all bodies natural and artificial. There 
are many chemical compounds made by art, which, as far as we are. 
informed, do not exist in nature, and there are many natural bodies 
which art has not yet been able to imitate. 

The philosophical chemist sudies both the properties of the ele- 
ments, and the constitution of the intermediate or proximate com- 
pounds of the whole material world, as far as it is tangible by man. 
Of the chemical constitution of the planetary and stellaiy bodies, we 
have no knowledge, except from the hints that are afforded by the 
occasional projecuon to our earth, of stony masses, severed by ex- 
plosion from luminous meteors or fire balls, which occasionally pass, 
with great velodty, through our atmosphere. 

It will be ea^y understood, that the philosophical chemist under- 
takes an arduous and responsible duty, mvolving much manual skill 
and labor and mental effert, but the reward is rich and gratifying. 



* Some objecl to this phrue, preferring to consider coiobastioD wbeitiftoDly in ex- 
■mpleof iDtenaeobeiuiealactloni Ibiivtew ispbila-iopliical ; butcombuNlion Usofre- 
queol sn occurrence aiid invalvon to many impomat rhenilcal evanta, that i[ la con- 
veoien), io accordance with the gcneol praclice of iDiDkUid, to designate it and 
(he bodies cancerned in it, by ■ pecullRr phraKotogy, 

. I It iiperhapi doubtful whore some of Ihu-ic bodiadoutchtlo be ciaased — nhelher 
among luotals, or combuitibles. 

t Perhap* sUlcMi and bromine ; we have however ciaucd Ihem where Ibey ap- 
pear to belonic. 



OMzcdoyGoOglc 



30 INTRODUCTION. 

The veil is withdrawn from the face of natore, and a constitutioti 
of things, not at all suspected bv those ignorant of chenuBtry, is un- 
folded. 

The pupil in this science discovers that he has, all hia life, walked 
uncongciously amidst powerful, although uoseen eneipes ; that like a 
child scattering sparks among gun-powder, he has often been nxut- 
ing with dangerous elements, and that, with all hia curiooK ana in- 
telligence, he has known only the surface of diings. He finds, eve- 
ry where, innumerable applications of his knowledge to purposes of 
praciicai utility, to those of domestic life, to the arts which enricli 
and adorn society, and to the illustratioQ of the wisdom, power and 
goodness of that great being, whose pleasure called the physcal utu- 
verse into existence and constantly sustains it in order and beau^. 

To exhibit the proof of these statements, even in outline, wouM 
require a distinct recital, and might well occupy a treatise ; — but op- 
portunities will occur in the progress of this work, when these trulhs 
may be, to a certain degree, illustrated. 

It would be premature, to attempt, at this time, lo exhibit the na- 
ture of the evidence upon which caemical deductions are founded, 
and tlie mode in which the study and exbilntion of the science are 
prosecuied. 

It is sufficient to say, that like the other physcal sciences, chemis- 
try derives its evidence, from experiment, and the observation of facts ; 
but, as u great proportion of the facts are such as do not occur in 
common hie, and still, as they all have their foundatitHi in the consti- 
tution of tlunga, it becomes necessary for the philosophical chemist 
to perform a great number of experiments ; in c^er words to exhibit 
numerous facts ; for, an experiment is nothing but the exhibition of a 
fact, happening according to natural taws, which it is not in our power 
either to create, to cancel or to modify. Hence, the necessity of be- 
coming well acquainted with those laws. Whenever all of them 
shall be fully understood, then chemislry will have reached its perfec- 
tion, and in relation to the science, the greatest service which we can 
perform, is to extend and perfect its general laws. At some future 
<]ay, it will not be necessary to study facts so much in detail as now ; 
selections will be made to illustrate general principles, and thus chem- 
istry will be assimilated to natural philosophy. 

Chemistry may be regarded in three views, all of wliich are inter- 
esting and important. 

1 . As a branch of general philosophy. 

2. As a school for the chemical arts and for many of those of do- 
meslic economy. 

3. As an important auxiliary to the profession of medicine and to 
pharmacy. 



OMzcdoyGoOgle 



rNTBODUCTION. 21 

la accordance wiib aU these views, it is now ardentlj and perse- 
vemigly cuhivated, id every- enlightened country. In every university 
and medical school ; in every college ; in many academies ; in volunta- 
fV associations, in larger and smaller towns, supportine Lyceums* and 
AthenKums ;* in pwular courses of lectures, sustabed by private indi- 
viduals; and even m manufacturing e-stablishments, fostered by the 
zeal of the operative artisans ; chemistry, with the »ster sciences, 
natural philosophy and natural history, is assiduously and advantage- 
ously ciUtivated. It would in this age, be as disreputable for any per* 
S(m, claiming to have received a libend education, or to possess liberal 
knowledge, to be ipwrant of the great principles and the leading 
facts of chemical as of mechanical philosophy. Many iuteUigent 
artizans now resort to philosophical lecture rooms, to learn more per- 
fecdy the piinciples ol their respective arts ; and the great familiarity 
with the practical facts of their callings which they, of course pos- 
sess, and ordinarily in a degree superior to that attained by teachers 
of science, enables them to apply with great advantage the general 
principles which they acquire. 

Domestic economy is gready benefitted by a correct knowledge 
of the principles of natural science and especial^ of chemistry. 
Besides the mstances that have been ah^ady named — the combus- 
tion of fuel ; the equal and economical aistributi<Hi of heat and 
light; the preservadon of delicate fruits and of their extracts or 
jeUies ; the preparation of Ibod by steaming, bcnling and roasting ; 
the extraction of animal gelatine ; the manufacture of starch ; the 
separadon of butter and cheese &om the milk ; the bleaching and 
d^ebg of stu% and many more domeMic arts depend upon theprta- 
eiples of science, and chiefly upon those of chemistry. It is true 
that these things are accomplished, with more or less skill, by pet- 
sons unacquainted with science, but they would be better and more 
efiectually done, were the ardsts enlightened more generaUy in its 
|vuiciples. To insist on no other instance, there is no doubt that 
m the common modes of using fuel, a large part is wasted, ^nd that 
pan skilfully applied would be more effectual than the whole, as it is 
m most cases acmally used. 

There is now, generally, but one opinion as to the importance of 
chemical science to the professiw of medicme. This opimon is 
siifficiendy evinced by the fact, that there is no medical school in 
which chemistry is not taught, not any medical examinatiiMi in which 
this topic is omitted. It b tnie that medicme may be practised, em- 
pirically, by those who understand neither the structure of the human 
frame, nor the nature and properties of the substances, which they 



DK;,lz=..,C00g[e 



22 INTBODUCTION. 

adminiMer. But who would choose to trust such men ; ot those 
who, equally uninformed, as to the nature of thingg, mix, compound 
and rend, by precept and example alone f Both may indeed do it, 
to a certain extent, successfuUy, but it is travelling bluidfold, and, at 
the same time, leading others. Medicine and pharmacy both need 
the aid of scientific chemistry ; th«i they can proceed with intelli- 
gence and confidence — they con shun and rectify errors, discard 
abuses, and add new resources to the healing art. They will avcAi 
mixing incannstent and mutually subversive ingredients ;— they will 
reject the spmious uid inert— scrutinize, with ^lill and knowledge, 
the genuineness of medicines, and avrnd painful— eometimei fatal 
mistakes. 

The principles of natural and experimental philosophy as well 
as of chnnistry, should enter into the education of a medical man ; 
and if he has not been already initiated into these elements, he 
should neglect no favorable opportunity of acquiring them. Tfaey 
are constantly brought into view, along with the [uinciple of life, in 
reasoning upon the phenomena of the human frame ; and in surgery, 
a correct knowledge of mechanical principles is of the utmost import- 
ance. A knoMedge of natural philosophy should every where b&— 
and in some seminaries it is — an indispensable qualificaticHi for medt- 
ealprivileges and honors. 

The enlightened medical man will regard his profession in a high- 
er view, than as bebg merely a business, by ntich be may live. 
Tbe true physician is a man of extensive scientific acquirements- 
No other profession demands so much scientific knowledge ; and 
when this is possessed, by a man of powerful and ardent mind, and 
united to habits of persevering and industrious exertiou, the medical 
man may become entitled to a distinguished rank among philoso- 
phers. Probably, science is more indebted to medical men than to 
those of any other profession. Every young man, who, with com- 
petent talents, enters upon the study of this profession, should aim at 
acquiring enlarged views of general as weU as of medical science, 
and ^lould endeavor to add something to the commtm stock of know 

The physician, who possesses the true spirit of his profession, will 
aim at a still higher excellence, that of b^ng a good man. Familiar 
in the confidence of families, having access to cdl, in the hour of sor- 
row, and of tenderness, and weakness, be is, if virtuous and amiable, 
regarded as the common fiiend of mankind. It is however in his 
power, to sow moral coitagion, or to difiiise the happiest infiiieace. 

In concluding, we may observe for the sake of the general stu- 
dent, that, 

LiTEBATCRB ftdoms and illustrates science, adding much to its 
attracticms, and to the method, perspicuity, and efiect of its ccHomuni- 



OMzcdoyGoOgle 



INTSODUcnON. 33 

cations. It canoot be entirel]' neglected, b^ any one who would 
claim an elevated rank in physical science. The accounts of tho 
most valuable researches and discoveries are, to a degree disgraced^ 
hy being ciothed in a coarse and slovenly style, and communicated 
without good arrangement, and without lineal clearnesi and pre- 
ci^oo. It sometimes happens, that able philosophers and mathe- 
tnaticiens are accomplished scholars, and then toe utmost finish ia 
given to the solid stnicturei of physical science. 

No one who has had opportunity to appreciate their attractions, 
and their utility, can be insensible to the advantages and pleasures of 
polite literature, and of miscellaneous knowledge presenting as they 
do, a rich field for investigation, and a^rding to the student, ample 



But — ars longa, vita brevu, meets us at every turn ; and, although 
the general student, in the regular prt^ress of a univer^^ education 
is of course, made acquainted with the outlines of the principal 
branches of human knowledge ; b after life, we are obliged to say, 
non omnes omnia potnimtu, while reluctantly giving up the rest, we 
select and pursue some one art, science, or practical profession. 

But our previous efforts are not lost ; the camnuaie vinculum 
irtiich connects all the departments of human knowledge, still re- 
mains unbroken j the intellect which tias been eiuiched by the ele- 
ments of science and literature, continues to shed a portion of their 
lustre over its own particular pursuit, and occasionaUy to aid, by use- 
ful suggestions and partial efibrts, those who are travelling upon some 
Other route. 

Knowledge is said to be power ; it is indeed, power of the most 
coinprehensive and efficient kind. 

l&owledge is nothing but the just and fiill compreheniaon of the 
real nature of things, physical, intellectual, and mmral; it is co-ex- 
tensive with the universe of being ; reaching back to the dawn of 
time, and forward to its consummation. 

It is inseparable from the incomprehensible existence of the creator, 
who alone intuitively sees the whole. Human life is sufficient for the 
acquisition of only a very small part of universal knowledge, and the 
greatest and the most enlightened mind, measuring its acqiurements 
by this standard, will find no cause for pride. 

It is useful when we are about entering on the study of a 
particular science, and especially of one of so great extent and 
interest as chemistry, to remember that there are many other inter- 
esting and useful branches of knowledge, and that we always assume 
too much, if we claim all importance and every attraction, for a par- 
ticular pursuit. This is necessarily the feeling of every one who 
insulates himself within bis own peculiar dominion ; but he who takes 
a comprehensive survey of human knowledge, wiD learn to appre- 



D,„iz=. ./Google 



24 INTKODUCTION. 

date justly his own acquisitkxis, and to concede lo otkers the favor 
which he would claim for himself. 

* * » * « * » 

Probably the greatest step that has been made in chemical science 
»nce the discovery of oxygen and chlorine, is in the establishment 
of the doctrine of definite proportioDS, depending oa the combina- 
tioD of the elements and ot the proximate principles in certain fixed 
ratios, — thus unexpectedly, giving to cheniistry a mathematical basb. 



OMzcdoyGoOgle 



Part I. IMPONDERABLE AGENl'S. 



Sec. I. LiQHT. 

" Light is the agent of vision." 

The hUtory ofiii mechanical affections bdongt to Optict, but some 
general facts may be advant^eously stated here. 

1. Its Matehialitt. — By some !t is supposed to result from 
the vibration oi »i^tyle elaitic media; but every thing goes to counte- 
nance the idea of its maleriali^, and this was admitted by Newton.* 

It catmot be tixighed, because our balances and organs of sense 
are not sufficiently delicate. 

2. Its Velocitt u two hundred thousand-^ miles in a second ; it 
is seven or eight minutes in coming from the sun, and were its weight 
the million-miliionth, or billiofith part of a grain, it would, by its 
impetus, destroy the firmest bodies. Nine millions ofnarticles of that 
^ze would not affect our most delicate balances.^ — Thorn. 

Momentum, being made up of velocity and quantity of matter, it 
results, that any degree of momentum may be produced by increas- 
ing either the quanb^ of matter, or the velocity ; it therefore follows 
that the particles of light must be inconceivably small. 

3. Its velocity is progreanve, and has been measured, by ob- 
serving the eclipses of Jupiter's satellites, when the primary is nearest 

* Dr. UrehMBiven a diftereat view o( litis nahjeet—Dicl. 8d Ed. p. 568. 

t One huudrea and ninety-five thouiand. — L, U. K. 

X " The mateililit; af Light it luffidentlj proved. lie motioii, Chough ioconccir- 
ablji TUiid, u progrotsive, and miy be meuaured ; ll may be alopped in its progress, 
or it! direction may be chanced \ i( may bo tondeoaed into a amaller, or dlspened 
over a larger space ; it is InlMcted when pasning near to any body, which proves it 
to l>e subject to gnvitatlou ; it produces chemical changes in many Ijodies, exists in 
them in a state at combipatioo, and is disengaged by the exertion of new affinities, 
when it appears in Its original Tgrm." 

" There is no physical point (sa^ Melville,) io the visible horixon, which 
does not send rays to every other ptnol ; no star in (he heavens which does not 
send light to every other star. The whole horizon is lilted nith rays from every 
point in it, and the whole visible universe wilh a sphere or rays from every star. In 
short, lor any thing we know, there are rtys of light Jnning every two physical 
points in the universe, ami that in contrary directions, except where onake bodies 
intervene." A ray of lighl, coming froin any of the Gied stars to the human eye, 
" his to pass, in every part of the intermediate fipace between the paint from which 
it baa been projected, and our solar system, Ihrougb rays of light flowing in all 
direclioDB, from every fixed star in the universe ; and hi reaching this earth, it lias 

. ..1 -B the whole ocean of the solar light, and I bat light which is cmilted from 

¥ct in this course its pn^ess has not been in- 



D„tiidD,Googlc 



36 LIGHT. 

to and farthest from tlie earth. Seven nunutes are now allowed br 
calculation, for the passage of lieht from the sun to the earth, and 
one twenty fourth of a second for its passage, from pote to pole, of our 
earth. — l. u. x. 

A body cannot be seen through a bent tube, except by reflection, and 
the shadows of bodies are exact copies of the form of the original. 

4. It move* in right lines ; never in curves ; if turned, it is always 
ai an angle. 

5. Iti rayt art mviually repellent, as they always diverge,* if mov- 
ing uncontrolled ; as observed when they are let into a darkened 
room, through a bole in the shuttei^— espemlly when the dust is 
raised in the room, so as to render the pn^ress of tlte rays viable. 

6. It obcis tbe laws or attraction. 

/( it r^Toeled in pasting from one tratupartnt medium into atir- 
other ; going obliquely from a denser into a rarer medium — the re- 
fraction is always from the perpendicular, and vice versa ; there is a 
constant ratio between the sine of the angle of incidence, and that of 
refraction. 

A piece of money being placed in a bowl, and tbe eye so situated 
as just to lose sight of it, is rendered viable by pourkig in water. 

A stick, standing out of transparent water, spears bent at tlie 
surface. 

A river, pr other transparent water, is deeper than it appears to 
be, because the image of the bottran appears too high. 

7. The amouTU of refraction it proportioned directly to the dentiti/ 
of the body. 

Infiammable bodies refivct in a higher ratio, and of course, inflam- 
mable gases refract more than those that are not. At 32" Fahr. and 
pressure 30, the refractive power of the follQwing gases is as foUows ; 
Atmospheric air, _ . . . 1.00000 

Carbffliic Acid, 1.00476 

Azotic Gas, 1 .03408 

RfciriadcGas, 1.19625 

Oxygen Gas, 1.86161 

Sub-carburetted hydrogen gas, - - 2.09270 

Ammonia, . _ _ . . 2.16851 

Hydrogen Gas, 6.61436+ 

In general, the refractive power increases with tlie density of tlio 
body ; but inflammable bodies, hydrogen, phosphorus, sulphur, dia- 
mond, bees-wax, amber, spirit of turpentine, linseed dl, ohve oil, 
camphor, &c. have a refracUve power, from two to seven times 
greater, in respect to dieir density, than mgst oilier substances. 



* Rsyi from the >un aod Tixed ular!, iiUhou);h JiTFr^rnt, a 

t>er>u*e the immcniie dislonco rcn>!ct» llie aiigtc of divcr^i 
1 Heory, Biot, Arago. 



ilciy E 



doy Google 



UGHT. 37 

1^ Isaac NewbKi observed this fact w!th respect (o tbe diaiiKxid, 
which he thought was probably "an unctuous substance coagulated," 
thus anticlpadng the discovery of its inflammability.* — ^l. u. k. 

8. Light luffert r^lalion. 

The angles of mcidence aod reflectioo are ahrays equal, as is 
observed in a common plane mirror ; when two persons oa oppomte 
sides, standing each at the same angle, see each others images. 

9. AU oigeeti teen by reaction or reflection appear in the direc- 
tion of the riveted or reflected rat/, 

Tiia is oonflrmed by constant expeiience. 

10. Lig/ii undcrgoe* polarization.\ 

" lliis name has been given to a proper^ of light, which causes 
it often to be divided into two portions, one of which is transmitted, 
the other reflected by the same pane of glass : or one portion sus- 
tains refraction in an ordinary degree, the other in an extraordinary 
<tegree. Again, all these properties are found to be commutable ; 
so that the portion of the rays which is reflected in one case, may- 
be tnosmitied in another ; or thai which in one case sustams the or- 
diaary refraction, in anodier, may undergo the extraordinary refrac- 
tion, and vice versa. 

These phenomena are ascribed to the different positions assumed 
by di^rent sets of rays ; certain poles, which they are supposed 
to possess, being variously directed at difierent times, so as to de- 
termine their reflection, or transmission, or (he degree of their refrac- 
tion. "| This topic belongs to optics.^ 

11. lAght prodvcet Uttle or no heat. 

The Lmar focus has always been said to exhibit no heat that can 
be indicated by the most deUcate tfaenD(»neter ; and that whether 
tbe rays were c(^cted by a lens co- mirror. No heat was feh in the 
pupil of Sir Joseph BarJcs' eye, from the lunar rays collected by 
Pancer's great burning lens. 

But Dr. Howard, of Baltimcve, by using his very delicate difier- 
ential thermometer, filled with etherial vapor, || apparently found a 
litde heat in the moon's rays. 

The lunar light is composed of aH the seven colors, as is evident 
in the lunu bow, and in tne lunar eircles.1F 



«ub«tBncei in dbq^nivc 



1 accouDl of thia eurloui property ofliEhl, tbe resileris referreil to Henry's 
', 10th Edit. Vol. I. p. 164.— AUo Edin. Enc. Articlo Opdci.~Nich. Jour 
It, p. 3B4, awl 94Ili Vol. of the Ann&les da Chlmie.Ure'a Did. 8d Edit 
568, tuA CBmbridgfl CourM of Mathemalies. ) Hare'i Comp. 

\ All tranaptrenl cryiitala polarize light, except (hoM whoae pritnxry Ibnn Is tbe 

cube or regulu- OGtohedron. Iceland cryitil (tfiamboidil c>lc-«par) ii by far lh« 

mo«t eoerEetlc. 

n Am. Jour. Vol. I] 



U Am. Jonr. Vol. XIV, p. S97. 



DK;,lz=..,C00g[e 



13. Light u not tintpU.-~-lt is composed of seven colors, a^ 
. separated by the triangular glaas prism, Id the ftJlowii^ otdei. 
30Q 

Red, Orafige, Tetlow, Green, Bhe, indigo, VioUt.* 
45 27 48 60 40 80 

beginning with the least, and ending with the most reGranglble. 

" Dr. Wollaston found tliat when a beam of light only one twen- 
tieth of an inch broad is received by the eye, at the distance of ten feet, 
through a clear prism of flint gla^, only four colors are seen, viz : 
red, yellowish green, blue, and violet. The diferent rays being aCatn 
collected by a lens into a focus, produced uncolored light." — a. 

13. Light is covtained ik ali. bodies. 

It appears to be both inherent in them, and to enter them from 
without, 

(a.) It patiet through gome imthout any tentible obttrvciion-~ 
they are therefore transparent, as glass, air, rock crystal, 8ic. 

Other bodies partially arrest the light, and others still allow a Uttle 
to pass, while some stop it entirely ; this gives origin to the terms, 
transparent, semi-transparent, translucent, and opake. 

Strictly, no visible body is transparent, and therefore aerial bodies 
are really the only ones that are perfectly transparent,')' and even they, 
become in a degree visible, in consequence of the disturbed refraction 
of light. 

(6.) Diversity of color ii produced by the abiorptum of some 
rays and the reflection of others. 

White bodies re6ect all, and black absorb all, or nearly all, with- 
out decomposition; when a body appears red, green, yellow, blue, 
Sic- alt other rays are absorbed and these are reflected. All per- 
sons do not perceive colors — we may very possibly find one such 
person, or more, in every considerable assembly, and many such in- 
stances might be collected. Harris, a shoemaker at Allonby in Eng- 
land, could distinguish only black and white ; when a child, he could 
not distinguish die cherries on a tree from the leaves, except by iheir 
form and size. Mr. Scott could not distinguish green. Pink and 
pale blue appeared alike, and so did red and full green — which he 
thought a good match ; several of the relations had similar defects.| 
A tailor rep^red a black silk and a blue coat with crimson. | 



* Quoted (rota Henry, lOlh EdiL Vol. I. p. 166.— Blue !■ not mentioned in u- 
ugning (he relalive spDcea, althougb it is mentioned <n the list of colont ; olher au. 
Ihors Bdsign GO la blue, diviiling (he whqle spectrum into 860. 

i Except chlorjae, and one or two othen. 

t Ph. Tr. IT7T, and 78, and SO. — l. u. i. A scDlleman of my icquaintant^ 
bought and wore a scarlet dresa mpposing it to be drab ; bUII he was a good judge 
ot pictures. I liavo knovrn Mveral such example*. 



DK;,lz=..,C00g[e 



14. Light ia emitted as well (u absorbed by bodies.' — Bodies that 
emit light are calied phosphorescent ; heat does not accompany this 
luminous emis^n. ' 

(a.) Solar p/uMphori are those which after exposure to the tun, for 
some time, emtt liglU in the dark. — Du Fay having exposed a diamtrnd 
10 the sun and immediately covered it with black wax, it shone in the 
dark at the end of several months, when the wax was removed. 

" In 1663, Mr. Boyle observed that the diamond when sU^tly 
heated, rubbed, or compressed, emitted a light almost equal to that 
of the glow worm." — Ore. 

Snow has been supposed to be a natural solar phosphorus, but this 
appears to be incorrect; for it does not shine in a perfectly dark 
place ; it seems to operate merely by reflecting the ught which is 
abroad even in the night, except when the clouds are very heavy, in 
the absence of the moon. 

(6.) There are artificial solar phosphori. 

Canton's preparation. — Sulphurei of time, made by stratifying 
burnt oyster Jielfs and flowers of^ sulphur, and beating them m a phial, 
or in a crucible in a furnace. 

Bolognian pko^k&rvs, viz, sulphate of barytes partially decom- 
posed into a sulphuret by igniticHi, with flour, sugar, gum arable, 
starch, &u;. 

Baldwin's phosphorus is fused muriate of lime. Hombetg's de- 
pends 00 combustion. (See alum.) 

Herring, macbarel, (or other marine fish,) being put into a phial 
with water and about one eighth of its w^ht of common, Epsom, or 
Glauber's salt, and conveyed into a dark place ; a luminous ring is seen 
after three days, and the whole fluid appears lummous when agitated.* 

The phosphorescence of fish when hung up in a chimney comer, 
and of rotten wood, tie. is probably owing to decomposition prece- 
ding putrefaction. Peat eanh is phosphorescent. 

Canton's preparation and Other solar phosphori, on being exposed 
to the light, shine in the dark, so that we may tell the hour by a 
watch, and when th&y cease to shbe, they again acqiure the power 
by a new exposure. 

(c.) Some bodies become phosphorescent hy heat, — Fluor spar, 
phosphate of Ume, many varieties of feldspar, and many lime stones 
ore of this class. It is usual to pulverize diem coarsely, and to throw 
(hem upon a red hot shovel in a dark place. The fluor spar from 
Monroe, seventeen miles west from New Haven, is a most remarkable 



' If (ha aBliDe Nlutiotu are le „ ..__^ , ..^... 

tppcRrt on dilation with water. Ebullition destrovs, but congelatioD only HUpcad* 
IhQ property, which appears sgala on Ibawing.— &r«. 



OMzcdoyGoOgle 



example.* It gives a vivid emendd green light nbich ooodnues Ibr 
B kntg time. 

Some varieties of marble, heated to a degree that would only 
make other bodies red, emit an intraisely briUisnt white U^it. — Tttr. 

The dried volk of an egg becomes lumioous if heated, and so 
does taDow, when thrown on a hot shovd or bimiing coals ; both shov- 
el and coab ^uM be rather below redness. Some bodies ceaang 
to «Tiit light by heat, become ^ain luminous by increase of heat. 

(d.) Some emit Ivii by pervuttion, friction or pratwe. — The 
Dolomite of Litchfield county in Connecdcut faintly flashesg when 
pounded in a moRar ; light is seen when lumps of sugar, or of 
qimrttjf w borax, or bonnet cane, are srauily rubbed or struck to- 
gedwr, in the dftik,— -certain varieties of tremtwte and erf' blende gire 
Sgfat when the point of a knife is drawn across tbem.^ 

(e.) Phorphoracence is leen in tome animaU. 

Theglow worm, and several species of fire fly are examples. -The 
luminousiess of the waves of the sea in a storm, or under a vessel's 
bow, or of WMor taken from the sea and agitateid, is very remarka- 
ble ; this phosplnrescence is owing t& animal matter dissolved in the 
sea watw, or to fiving animab, as the medusa, cancer fulgens,^ be. 

When tbe sea water is filtered so as to tcmore the anunals, it is 
said to lose its phosphorescent power. 

Lt. H. Ingalls, of (he U. S. Army, is of opinion that the phospho- 
rescence of the ocean is owing to the ovula of fishes. He stnick 
his arm, while bathing, agunst a soft mass, which emiued flashes two 
i>r three indies kmg, and he even ctmvinced himself that there was 
a miM degree of heat, gnit€^lto Ins (ouch. The jelly like masses, 
seen upon a beach after the retiring of the tide, he conceives to be 
&e bodies in question ; that these masses are phosphOTCscent, was 
proved by their emitting bright light, when irritated by the point of 
a pencil, especially in a particular opake point, appearing to be tbc 
punctum sabens of a living animal ^lich the sun hatches, by de- 
grees, from the jelly like mass, and the tide eventnaHy shakes out. 
^%ere is therefore the fullest reason to believe that die luminousness 
of the ocean is owing to animal matter. || 

Fresh water is not phosphorescent ; the waves of the great North 
American lakes, ^though violently agitated by tempests, exhibit no 
tuminous appearance. Air or its absence has no eSbct on phospho- 



(/".) PAotphomemee it produced by cftaiuad scrion. 

^ Am. JouT. 11,142, 

t Quartz pbapIwreiCM cveo UDder wttet. — Ure. 

t Dr. Bremter'i EdiiL PbU. Jovr. Vol. I. Nicbolwa'i Jour. Std. Vols. XV, XVI 
■Dd XIX. 
§ TUtoch'i PUI. Hig. V. 87. and 88. \\ Tnuu. oT Albuy Inatitute. 



OMzcdoyGoOt^IC 



IMSa. 31 

Condniation is a famttu aad very genenJ example. Pbfo- 
pborescence, without combustiMi, is seen in the case of WjAuric acid 
md calcined inagaesia ; when the magneaa has been recendy and 
thonx^hly calcined aad tbe ulphurie acid is stnmg, there is ahaoet 
always (es^iedally if a few ounces of the raateriab be used) s flash 
in tbe dan, and sometimes it is visible ia the day light. 

Lime slaking in Ae darii, sometimea shows lumiaous points.—- 
JJf^ ie eimtted during the conduBatton of sh^ut and meuUk: 
Smgs, as copper and ivo]»->-ofpotassiuan and s«tpbar,iodiDe and phos- 
phonis, &c. ; that from iodine and phosphorus is very vivid. Itis ne- 
cessary only to dirow a Utde iodine upon a small piece of ^tospborus 
in a dry wine glass; the action is speedy or even instantaneous; a mild 
heat may being it on when it is tardy, Ua we shouU be tM our guard 
against explosion. The same remarks wiH spfiy to iodbie and po- 
tassium, only the action ia mote violent, and the burning potaoium is 
often thrown about tbe room. 

16. LlOHT IS A. CBEHICAI. IGXNT. 

(a.) It (kU mt vegetaMe: — EtidatioD or UeacUng of ve^tahles 
by ^ing them up, takes effect in consequence of the exclaaion of 
l^tt. Ce2«ry is white, mUd, and BgreeaUe wlwn gnwing beneath 
the eaitb, but acrid, uid as is said, even poisoDoua it grovmg in Ae 
light ; the poitOve root is ^ected in a similar maimer by ligkc 
Shoot* of polatoei, tvnipf, aAbage, panmp, earrtt, ^. are mild 
and white when sprouting in a motst, dark cellar, but if a beam of 
light crosses them, as fiom a crack, or a bole in a vriadnw, they be- 
c<»ne col»ed and pungeat, and inchne towards the l^iU. The m- 
side tt»va of headt of cabbage or Uttwx are white and tender ; ao 
are the inner coats of Miions, the bottom pans of blades of grass, 
e^eially when shooting from beneath a flat stone, and mnei when 
growing in the same manner. 

The bark of trees is generally more cokired than the wood — but 
woodt are ocauumaUy deep colored, as the dye woods and roots, 
logwood, fusiic, brazil-WDod, lignum viUe, madder, turmeric, quercit- 
ron, alkanet, &c. and the heart of wood is somMknes nore deeply 
colored than the superior layers, as in the red walnut. 

Many causes opmte besides li^K, e. g. heat, air, cheoueal cms- 
podtion, be. But even colored woods generally grow deeper colcw- 
ed by exposure to light, e. g. mahogany, cherry, black walnut, ma- 
ple, &£. as seen in common furniture. Red roses made to grow in 
tbe dark bectnne white, or rather the trees that produce red roses in 
tbe light, produce white ones in the dark.* — Davy. 
■ (&.) Mthovgh the color of vegeUjtUa m not pradwed exduiiveltf 
6y Jigktj it u owing prindpaUii to that caute. 



OMzcdoyGoOgle 



■33 LlOHT. 

(c.) Their pungency and aromatic propertiet d^nd very mucA 
*pon the Ught. 

Plants growing in the dark "contain an excess of saccbKrine and 
aqueous particles ;" they are destitute of color, odor, and pungency, 
but acquire ihese properties if transferred to the light.* 

[d.^ Light it most abundant in the torrid zone, and there the ver- 
dure IS the most intense ; there also we find the richest gums and 
lesins and the most odorant aromatics, and the foliage is there most 
abundant; but other causes beddes light coniribute to these effects, a» 
beat and moisture. 

(e.) lAght extricata oxygen gat from fresh green vegetahles, 
which may be collected in an inverted bell glass, lull of water, and 
containing the plant also. Carbonic acid gas is evolved in the night. 

{/■) lAght u a sttmulttt to vegetahles. — Their leaves incline to- 
wards ibe light : plants growing m windows do this ; some flowers 
open their petals to the light and shut them at night. 

Camphor kept in glass botdes exposed to light, crystallizes in the 
moat beavnifid symmetrical manner, and more particularly on the side 
next to the light. 

{g.) Jjight sometimes weakeju or discharges co/or.— Yellow wax 
in thin layers becomes white ; stamped goods, as curtains, and those 
stuSs that are colored b the thread, as carpets, have their colora 
faded by light : these colors are usually of vegetable origin, modified 
more or less by mineral mordants. 

16. Light acts o» aniiiai,s. 

(a.) lAght exalts the color of animals . — Worms, grvhs, and larger 
anvnals that live in the ground, are generally possessed of dull colors, 
without beau^ or vivacity. 

Birds and insects of night are generally of duU ft««.— Owls, 
night-hawks, whip-poor-wills, certain varieties of snipes or wood- 
cocks, 8tc. and the insects of summer evenings, have generally no 
beauty of cobr. 

(i.) The <^osite is true of a great proportion of the various 
cUmes of animals ^at are much abroad in the day li^ht. 

Generally the vivacity of color is greatest in the animals, birds afid 
insects of the tropical regions, and the opposite is true of the polar: 
the temperate, as we might suppose, occupy a middle rank in Ihese 
respects. 

* Dr. RobinxHi, " Id the drain of a coal work under gitnind, Bccideotiilly lud hh 
hind upon a very luxurtant plant, with larfte indcuted foliage and perfectly while. 
lie had not leCD any thing like it, Qor could aoy one Infarm him what il was. — , 
He had the plant with a Bod, brought into the c^eii air in the light. In K little 
lime the leaves withered aDd soon after new leavee began ta apHng up of a green 
color and of a ditTerent shape from that of Iho old ones. On rubbing one of the 
leave! between his fingers, he found that it bad the imell of common luuy, and 
ultimately proved to be that plant, wbich hid been to ch*nged by growing in tho 
dark." — Rees" t^clopedia. 



OMzcdoyGoOgle 



These can be regarded as only generaJ truths subject of course to 
many ezcepdons and qualifications. 

In inrdi, the parts exposed to the light, as the bacli and bressi, are 
always colored, but the feathers beneath the wings and under the 
belly are usually white. — So the back and fins of iishcs are colored, 
irtiile the belly is white. Snakes and other reptiles, and the am- 
phibious animals arc distinguished in the same manner. 

(c.) JTte color of the human species it generally graduated tn toU 
eraUe accordance with the quantity of light ; black people are not found 
perhaps any where except within the tropics, and white ones no where 
but in the northern temperate zone ; but tlie state of society, food, 
habitations, employments, and many other causes, modify these results, 
and it is to be observed, that the colored people of [xilar climates, are 
bU barbuians, living in »noke, filth, exposure and wretchedness.* 

(rf.) The color of persona, of the varimis classes and conditions 
tf society, accords toUh this new. — Students and artisans, working 
widiin doors, and women, whose employments are, in this coun- 
try, generally in the house, are of lighter complexions ; while far- 
mers, sailors, soldiers, &c. are more deeply colored. Many other 
causes, especially those afiecting the state of heahh, do however mod- 
ify these results. 

(e.) taght ii necessary to health and theetfvlnesi. — Animals and 
men, confined in darkness, become gloomy, and their healtli and their 
faculties are gradually impaired. 

In the human subject, when long deprived of light, dropsy is said 
often to terminate life. 

Other physical causes also operate, as want of exercise and bad 
air, and moral causes must also powerfully affect the human mind. 

Even animEds are affected, in a way somewhat anak^ous. 

18. LlOHT ACTS ON HINIBAL BODIES. 

JVitrtc axxd is decomposed into nitrous acid and oxygen gas. 

Aqneoas solution of chlorine gives out oxygen and muriatic acid, 
and most rapidly in the most refrangible rays. 

Metallic oxides are, in some instances, decomposed ; the oxides of 
mercury sometimes give running mercuiy. 

fFhte mariate of silver becomes dark, and even black, muriatic 
a<nd gas being formed. 

Chlorine and hydrogen gases, in equal volumes, explode by iJie 
Stroke of the solar ray and very quickly m the violet ray. 

Phosphorvs which is white, when first distilled in hydrogen gas, 
becomes colored, yellow and brown, by the action of light. 

Substances wet with nitrate of silver, become dark, and even black, 
by exposure to the sun. 



OMzcdoyGoOgle 



34 LIGHT. 

19. LlOHT PSODDCXS HAOHBTISM. 

This was first observed more than twenty years since by Morrichini, 
u Rome, and has been recently confirmed by Mrs. Sotnerville. (Ph. 
TV.) A sewing needle, an inch long, being half covered with paper, 
had the other half exposed, during two hours, to the violet rays, which 
imparted north polari^; the indigo rays produced nearty tbe same 
e^ct, and the blue and green in a still smaller degree. The yellow, 
orange, red, and invisible rays were inert, having produced no efl«ct 
in three days. Similar efiects were produced when tbe needles 
were enclosed in green or blue glass, or ribands of tbe stme color; 
one half being always covered with paper. The calorific rays pro* 
duced no e&ct. In these experiments it was ixH necessary lo dark- 
en the room. 

Iron* ore i>ot magnetic, becomes so by exposure ta light.f ■ 

HEHABK. 

When we have considered radiant heat, certain ditcriminaiiont 
may be made betvxen it and light, properly to ceUJed. 

Some of the effects, above described, probably belong to one sort of 
solar rays, and some to another, but the facts are stated whh refer- 
ence to the undecomposed rays, as they come to us from the 8im. 

20. Sources of Light, most of wKich are also tov.ree$ of heat. 

1. The Sun and fxed start, 

2. Combustion. 

3. Heat without comhustion, as iii an ignited stone. 

4. Percussion and friction. 

6. Chemical action unlhout combustion. 

6. Electric and Voltaic action. 

7. Animal power, as in phosphorescent living animals. 

"Organization, sensation, spontaneous motion end all die opera- 
tions of life, exist only at the surface of the earth, and in places ex- 
posed (othe influence of light. Without it nature would be lifeless 
and inanimate. By means of light, the benevolence of the Deity 
bath filled the surface of the earth with iHganization, sensati<Mi and 
intelligence." — Lavoisier. 

PHOTOMETBK. 

Mr. Leslie, by ha^g one baU of his difierential thermometerl 
made of black glass, adapts it, as he conceives, to the measurement 
of light ; but it seems difficult to distingui^ in this case, between the 
e^cls of heat and of light, unless we adt^t the opinion of the in- 
genious inventor, that light, when ^)Borbed, is converted into heat. 



OMzcdoyGoOgle 



HEAT OB CALORIC. 35 

SEC. n. HEAT cm CALORIC. 

OENKHJU. NATtmX OF TBI9 PD1TEB. 

1. Tkt ujuatio* prodvced in lu, bjf c hot body, we ailribute to a 
ftnetr vAick toe call neat — neitimig that which is the cause of tbe 

<Anaatirai_ 



3. 7%u MWfe w vnimo w t i' b«t» as that which excites in us tbe 
Reasation of heat, produces ai the same time, eXpanaon ia all tbe 
bodies, with which it communicates, both cSecta are attributed to 
one C8I1K. 

3. The tttui&of heat and of exparawn art ther^ore astumed to be 
one and t/u tame, and this uaknown cause is called, in modern chemi- 
cal langtnge, Caloric; (Calor, Lat. Calorique, Fr.)* but to avoid 
pedantry and repetition, the t^me. Heat and Caloric, are both 
occBscnftliy usea to denote the cause in question. 

4. Our letuationt of heat and cold are dependent, principally, on 
tlte motion of Ctdoric. 

(a.) When it is entering our bodies, we feel warm or hot; when 
it is ieavii^ us, we feel cool or c<dd, as the process is in either case 
more or less rapid. 

(b.) More accurately speaking— «e feel hot, or cold, according 
a$ the qMOttity of heat, that enters or leava «s, is greater or leas than 
the neeri^e tpmntity to which we are accuatomed — for heat is always 
flowing from us during life, and generally more rapidly than it is re- 
ceived, from without, as our natural temperature is higher than the aver- 
se temperanire of the air. If therefore, we lose mme heat than we 
are, on ibe whole accustomed to lose, we feel cold, and the reverse. 

(c.) Cold ii merely a n^ation of heat. 

The same perscHi may feel beat and cold in different parts of his 
frame at the same time ; for instance, by dipping at the same mo> 
nent, ooe hand in cold, the other in hot water ; or, by laying, simul- 

* The new nomenclature of Cbemlilr; bad ita anpa in France. 

Th< Dtcesfity of th<i reform arow from tbe prOf;ren ofdiicoTery. Th« IiDguage 
of Chemwiry bad become both erroneoui and iniperfact. Soma newly dlicoveicd 
twdies had no nauiei ; man; old namea were false, and olhcni hirbaraua or ridicu- 
lous. The period WM about 1786, at whicli timo the new nomenclature was per- 
fected. The principal agODU in Ihia reform were LaioiBier, Fourcro]', Horveau, 
nd BertholleL Morveau proponed the measure in 1782. The nomenclature will 
be eipliined in dcliil, as the lermi occur, — See Jour, de Phy. Tome lO.p, 370, 

My macb respected teacher, Pm^easor Hope, of (he University ef Bdinbu»h, 
it fire) colleague, umI afterwards aueeesmr to Dr. Black, was perfectly famlHar 
with the llluetrioua Latoisieb, In the later periods of his life, andwis fiilly ac- 
■UBinted with his discoveries and researches. Dr. Hope returned from Paria to 
Scolland, strongly imbued widi the new views, aod was the firat public teacher in 
Brllain wbo made them known, and who adopted the new nomenclature in his lec- 
tures, I had this from him when I was his pupil, 

Tbe late Dr. PeamOD, of London, was alto one of the first who promul^led tha 
Dodero Domencltture and dlicoveriei la Great Brllaio. 



D„tiidD,Googlc 



36 HEAT OR CALOBIC. 

taneously, coe band oa ice, and the other on a living wami blooded 
animal. 

Three persons, in the same atmosphere, may find it ccAd, hot or 
temperate, according to their previous exposure — their state of 
health, or dieir clotfaing. To bring this to a trial, let (me pers(»i 
come suddenly out of a bath of dS° or 100° ; let another come from 
an ice house, and another from the temperature of 55°, into a room 
of the same degree of heat. The first will feel cold— the second 
warm, and the third will experience no change. 

(d.) fVitkout moHon there it no tentatum. 

The motion of light . - - produces visioQ, 

That of air, - - - - . « heariDg, 

That of odorant matter - - - - " smell, 

*That of sapid substances, - - - " taste, 

*And that of all bodies in contact with us, " feeliac. 

Lavoiner. 

(e.) But mere tentation toovid not decide that there are not two 
causa, one of cold, and one of heat ; or that cold is not the positive 
principle, and beat the negation. 

Only reverse the reasoning — if we would contend that cold is the 
sole principle ; or reason in both modes, if we would admit that boUi 
causes operate. For instance — Caloric enters us, or cold leaves us, 
and we feel warm ; or cold enters us, or heat leaves us, and we feel 
cold.f But, to assign two or more causes, when one b sufficient is 
contrary to sound philosophy. 

(/.) Thesuniaajfermatientiourceofkeat. 

There is no permanent source of cold, and no fact can he stated 
on that subject which is not explained upon the supposition of the 
privation of heat. J 

5. The common opinion, that lome bodies are pontivdy and in- 
herently hot, and some cold, ia erroneous. 

(a.) We could have no certain information on this subject, except 
from the changes in volume, or in tbeir qualities, which various 
bodies undergo, when those that are supposed to contain more or 
less of heat are applied to them. 

For instance, the thermometer is our criterion, and its fluid either 
shrinks or swells, according as the body in contact with, or near it, 
is colder or hotter than it. 

Fluids become sohd, and again fluid, or, in other words, freeze 
and melt, according to the variadons in the quantity of heat 



■ In (lie two latter ceses, coQtact [iraduces the i<«iiiB(iDn, but trithout motion It If 
HWD dimlDished, d.iuI Iq (he lail Inalance. snan ceucs. 

t We must in this cona, ■ubadluto and for er, if we Would luppoK lioth rauMB 
operating at the >ame time. 

t The apparent Tidiation of cold nUI be ment[oned bereafler. 



J, Google 



HEAT Oa CALORIC. 37 

(6.) Than u heat in every thiiig, even io icft itself ; and there is 
no reason to believe that we have ever attained the maximuni of 
c<dd. 

6. Theri; ase rats of heat, distinct rsoH light. 

(a.) Tliey obviously pau from idl hot or wanii bodies, wheibeTlu- 
minmis or not. 

(&.) They flow from nearly all Itaninout bodies. 

(c.) From living animah. 

(d.) From hot water, and other hot Jluidt, excluding those that 
require ^ition to sustain their fluidi^. 

(e.) From a hot baH of iron vAvch it notluminou*; boax a hot 
stone, a liot brick, or other heated incombustible body.* 

(/.) From a dote ilove — supposing no chinks for the light to 
pass, and, 

(g.) Probably from all bodies whatever, sud at all temperatures, 
there is a certalD amount of radiation of heat, although me colder 
the body is, the less the radiation will be. 

7. Rats or Caloric ake emitted from the sun, and they 
are capable of being separated irom those of light. 

(a.) Dr. Herschel, u^g the telescope to kxdi at the sud, em- 
ployed colored glasses to diminish the hght; — when their cc^r was 
deep enough to screen the eyes, the glasses became hot and crack- 
ed ; in some cases there was very little light, while the heat was painful 
to the eye, and some glasses transmitted much light but very little heat. 
He therefore examined the heating power of the different rays, sep- 
arating them fay a prism, and permitting the difierent colored rays m 
the well known order of red, orange, yellow, green, blue, indigo, 
violet, to fall on a delicate thermometer — two other thermometers 
being placed near, as standards ; the thermometer which indicated 
die heat, lay upon an inclined table. 

((.) The heat wot greatest in the red, or least refrangible rays ; 
and tt was least tn the violet, or matt r^rangible. If when in the 
violet it was as 16 — in the green, it was as 33.4, and in the red, S6. 

(c.) The greatest Ulununating power wot in the middle of the 
spectrum, and it diminished either way. 

[d) . When the thermometer was carried beyond the red ray, and in 
the same line, the fluid still contintied to rise ; the maximum effect was 
half an inch beyond the red, Sfc. ; one mch beyond, the same as in 
the middle of the red ray; the heating power was sensible at one 
and a half inch beyond the red ray. 

(e.) The focus of heat is probably not less than one fourth of an 
ioch farther from the lens than the focus of Ught.f 

■ They tra tupnoHd to b« hot, in order that the radiatioD may be aTldent : Um 
ndiitioo muM etin, although in a leaf degree, if the bodlea were eold. 
I Phil. TrBM. ISOO, pp. 2S8— 9. 



OMzcdoyGoOgle 



3g HEAT OR CALORIC. 

The following figures represent the prism and prismatic ^cirum. 
;g; Should a ra^ faQ upon 

a prism, as represented 
in the figure, in the di- 
rection of the line, AB ; 
it will, on account of the 
obliquity of its approach, 
be refracted towards C, 
and emerging thence, 
I obliquely to another sur- 
face of the prism, H C K, 
~ — it will again be most at- 

tracted by thai portion of the surface towards which it inclines. 
Consequently, it will be refracted so as to proceed in the direction 
of CD. 

Thus it must be evident, that two surfaces of the prism have a 
concurrent influence, in bending the rays from their previous course, 
while in the pane, the influence of one surface is neutralized by that 
of the other. 

The lines, L F, and E F, being perpendiculars to the surfaces 
of the prism, A B L, is the angle of incidence, and, G B C, the 
angle of re&action, to the surface at which the rays enter the prism. 
F C B, is the angle of incidence, and E C D, the angle of refrac- 
tion to the surface, from which the rays emerge. — Dr. Hare. 



This figure represents a triangu- 
g lor glass prism, mounted upon a 
universal joint, supported by s 
brass stand, so as to be well qualifi- 
ed for the dispersion of light. 

A, The glass prism, supported 
at each end by a pi vol. 

B B, Handles by means of 
which the pivots are turned, so as 
to make the prism revolve. 

C C, Ball and socket, forming 
a joint, upon which the plate D D, 
may be moved, so as to assume 
any serviceable po^on. — Dr. Hare. 

Let A B, represent a part of a mndow shutter of a room, into 
which light enters only through the hole C. If the light thus enter- 
ing be recced on a screen, a circular spot on it will be made lumi- 




OMzcdoyGoOgle 



HEAT OR CALOBIC. 39 

nous. But if a glass prisin, D O E, be placed before the hole so 
that the light may fall upon the prism, perpendicularly to its axis, 
the rays which had before produced the luminous circle will be re- 
fracted aad dispersed, so as lo form the spectnim, r g v, consisdng 
of the foUonring colors airaoged ia the following order — red, orange, 
yellow green, blue, iod^, y'v^. 



H.^^; 



Theae experimtntt havt hten fiMy confirmed by those ef Sir 
. Englefield.~~Mur. In his experiineats there could be no 
e of deception, because eftdi Icind of rays, Grst separated bf 
the pHsn, was made to pass successively throiigh a four inch lens 
covered by pasteboard, except at one place, whoK ivas a slit ia the 
paper — the focus was thus formed in the air and the thermometers 
were there applied. 

In Dr. Herscfael's experiment, as the rays were thrown on a table, 
some fallacy might, possibly, have been suspected, from the reflectioii 
of the rays. In Englefield's experiment, the thermometer gave the 
tb&owing results. 
Ray- '"■»«- 



Blue in 




3' torn 65» 66» 


1. 


Green 




3 " 54 S8 


4. 


YeDoo 




3 " 56 62 


6. 


Fun red 




H •■ 56 n 


7.2 


Confines of red „ 




2J " 58 73i 


6.6 


InUdiHi, but near 


tberedu 


a^ " 6i 79 


21.6 



The difierence in die heating power of tbe gpeanan is so great, aa 
to be perceptible to the naked hand. 

(g!) Berard confirmed HerieheTi and EngUfiMt experimentt 
siAttanHaUy.* 



OMzcdoyGoOgle 



40 HEAT OR CALOHIC. 

Willi him the heating power increased from the violet (0 the red 
ray. The greatest heating power was in the red extreiiun of the 
spectrum and not beyond it. His maximum of heat was where the 
thermometer was still covered by the rod ray. The fluid in the ther- 
mometer sunk as it receded from the red ray, and entirely out of the 
red ray, where Herschel fixed the maximum, its elevation above the 



air around, was only (hic fifth of what it had been in the red ray- 

(A.) Red rayi are considered as cheerful, because warratli 

therefore comfort, is found to be associated with tliem ; such rays a 



emitted by burning charcoal and coke, and by a common wood fire ; 
those iitmi burning alcohol, especially if mixed with salt, are pale, 
and have very little heat in them, and are therefore regarded as 
gloomy. 

Mr. Seebeck has proved that the place of the greatest heat de- 
pends veiy much upon the nature of the prism : thus, when it is of 
crown or plate glass, the maximum effect is in the middle of the red 
— if of flmt, it is beyond the red ; if a hollow glass prism be filled 
with water, the greatest effect is in the yellow ; and if with sulphuric 
acid, it is in the orange ; so that different substances appear to difller 
in their power of refracting caloric* Still the important fact is con- 
firined, that there are rays of caloric, that they are diflerently refran- 
gible from rays of light, and that they possess unequal refractive 
power. 

8. Rats op calobic alona with bats or liobt are emitted 

TROM ALL BURNINO BODIES, AS WELL AS TROlf TBE SUN. 

{a.\ A plate of glass, presented to a common fire, intercepts the 
heat, out permits most of the light to pass, while it becomes itself hot. 

(b.) A bright metallic plate reflects both die light and the heu, and 
does not become hot. 

(c.) The same plate, if blackened with smoke, uik or paint, be- 
comes hot, and then ceases to reflect either light or heat. 

(d.) A glass mirror reflects only the light of a common fire, for 
it absorbs the heat and becomes sensibly hot; the focus is therefore 
luminous but not hot. 

In the sun's rays it forms both a luminous and a hot focus, and 
therefore reflects both the heat and light. 

(e.) A metallic mirror acts in the same manner, and also with a 
common fire, it reflect^hoth the light and the heat ; if blackened, it 
reflects neither, but becomes itself hot. 

(/.) A lens, before an artificial tire, becomes hot, and forms aaly a 
luminous image ; presented lo the sun, it concentrates both the light 
and heat, and produces both a bright and a hot focus, vdiile it scarcely 
becomes heated at all. 



' Edia. Jour, of Science, No. I, pa. SI 



OMzcdoyGoOgle 



HEAT OB CALORIC. 4| 

(g.) The panes of a commcHi wiodow do not become heated by 
the passage of the sun's rays through them ; or at most, the eHect is 
Kaicely perceptible. 

(A.) I^^ of caloric pass through glass with difficuUy, if the tem- 
perature be below that of boiling water, but they traverse it with a 
faciii^ always increasing with the temperature of the body emitting 
the heat, as it approaches the point where bodies became luminous. — 
Hen. 

(t.) Calorific rays that have already passed through a glass screen 
pass through another with much greater facility. Rays emitted by a 
not body di^r in their power of passng through glass. 

" A thick glass, though as permeable to light as a thin glass of a 
worse quality, or even more so, allows a much less quantity of radiant 
heat to pass ; but the difierence is so much the less as die tempera- 
ture of the radiating source is more elevated."* 

9. Rais of caloric, emitted vroh hot but not luminods 
bodies, can be reflected bt uirbor3, and brodght to a 

rOCDS. 

Hot water, hot mercury, and hot, but not luminous solid bod- 
ies are good examples ; e. g. a cannon ball, a stone, kx. 

(a.) In makiEig these experiments, either one mirror or two may 
be employed. The mimu's should be of copper, plated with silver; 
or, brass or tin will answer very weU, if highly polished. 

(&.) If one mirror be employed, the hotbody should be placed in 
the axis of the mirror and the thermometer ui the focus ; if two mir- 
rors are employed, the thermometer should occupy one focus and 
the hot body the other. 

10. Rats are emitted bt the scn which do not produce 

EITHER heat OR VISION, BUT EFFECT CERTAIN CHEMICAL DECOH- 
POaiTIONS OB COMBINATIONS. 

(a.) Muriate of tUver w tamitAed or blackmed by the naiU rayt — 
but in the piismatic spectrum, this eSect is least in the red ray, and 
increases constantly towards the violet ; the ratio of the bhie and 
red rays b inversely, as 16 to 30 — that is, to produce a given efiect 
in fifteen minutes by the blue, requires twenty m the red. 

(6.) Beyond the violet ray, the same efiect is still produced in the 
dark. 

(c.) Berard,f by a lens, ccmcentrated that part of the spectrum, 
fiom the green to the videt, and by another the portion from the 
green to die red. The focus of the last was a white point, scarcely 
tolerable to the eye, but it did not alter the muriate of silver in two 
hours : the other locus was much less bright and less bot, but 
blackened ihe rouiiate in less than so. minutes. 

■ De 1> Roche, Amidi of Phil. II, 100. t Add. cf MiU, II, 106. 



OMzcdoyGoOgle 



43 HEAT OR CALORIC. 

(d.) Guiacum passed from yellow to green during the exposure at 
the videt and, and returned to yellow at the red end : this is supposed 
to be an anomaly, as Dr. Wollaston ascertabed that the change to 
green is connected with the absorption of oxygen, and this principle is 
usually separated at the violet end. 

(e.) It is said that phosphorus, which kindles easily at the red ex- 
tremity of the spectrum, is exunguished at the violet end. 

(/.) The combination of chlorine and hydrogen is effected rapidly 
by the red rays, but without esploaon ; but the aqueous solutioa of 
chlorine becomes muriatic acid most rapidly in the violet rays ; " the 
violet rays produce upon moistened red oxide of mercury the same 
eflects as hydrogen gas." — Davy. 

(g.) Persons who had persisted in a long course of pills, formed 
by niuate of silver (lunar caustic) and bread, acquired a blue tinge 
in the skin, and in one case this was deepened by exposure to light.* 

CONCLDSIONS. 

11. The SUNBEAMS contain three different kinds of 

RADIANT MATTER. 

(a.) ,di leatt it u convemtnt, provitumaBj/ to to regard iium, as 
the effects are thus best understood. 

(£.) It u potsible, however, that they may all be varieiiet of one 
thing, and the apparent difference may he owing to unknown causes. 

(c.) The rays of the sun then appear to contain 

A. Rayt that illumitiate, but do not caiue warmth or shannon; 
they may be called colorific rayi. 

B. Itay» that caiue warmth and expansion, but do not iUvMinate ; 
they are opake, and may be called calorific rayt. 

C. Rays that produce neither color, nor heat, nor cxpaiuion, htU 
that caiue certain chemical effects; they also are opake and may be 
called chemical rays : bysome they have been called de-oxidixtng or 
hydrogenating rays. The first term is preferable, on account of 
its brevity. 

12. These three kinds of rays all come from the tun in company; 
hence the triple effect of llie sotar beam, in warming and causing 
expansion, in illuminating or imparling color, and in producing cer- 
tain chemical effects. 

13. In the moonU rays, there it chiefly lightvrUh little or no heat. 
Mr. Brande has ascertained, tliat the lunar rays do not blacken 

muriate of silver. f 

Popular opinion ascribes to them llie power of stimulating vegeta- 
tion, and of causing putrefaction in 6sh and other animal bodies, upon 
which they may chance to fall. 

14. Culinary fire, as all know, emiisboth the luminous and theheat- 

•Cooper'sThomion.nole.ediLlSlS, Vol.I.p.81. * t're's Diet. p. 66T. 



OMzcdoyGoOgle 



HEAT OR CALORIC. 43 

iag rayi ; — but it has not been ascertuned that the de-oxidizing chem- 
ical rays are present.* 

15. T^myncal lawt of all the three vafietiet of raya are nearly 
the tame, d^ering a little in ike amount of the effect. 

(a.) They are refrat^ihle ; this is proved by Aeir passing through 
the prisni, and being all made to deviate from their course. 

(n) They art r^angQ>le in different degrees ; and this is true, 
whether we eompare one sort of rays with another, or the rays of 
one kind individually among themselves. 

(c.^ Some rays of each kind are equally refrang^k, and are there- 
fore iound in company through the whole specorum. 

(rf.) Some ray* of caloric are less refrangible than any of the 
other rays of either kind; therefore they are found outside of the 
red rays in the dark. 

(e.) Some of the chemical rays are more refrangihle than any 
other, of either kind; hence they are found outside of the violet ray, 
and in the dark. 

(_/! ) The spectrum, then, is composed of the three sorts of rays, but 
it is terminated by calorific rays on one side, and by chemical rays 
on the other; on both wings it has opake rays, but ol different kinds. 

{g.) All the kinds of rays are refiexHAe. — This is evident from the 
effect of nurrors ; and Scheele long ago, ascertained the equality of 
the angles of incidence and reflection. 

{h.) At a given distance from the radiant point, the intensity of 
botn heat and Ughtf is inversely as the square of the distance, e. g. 
At the distances 2, 3, 4, it is as 4, 9, and 16 inversely. 

16. It iiprob(Ale that all the three kinds of rays are emitted from 
the sun, and other sources with equal velocity. 

We are not informed as to what is the cause of the differences be- 
tween solar and culinary heat. 

17. It is evident, that the particles of all the three varieties of raya 
are minute, to a degree beyond our powers of conception ; probably 
they are equally minute, but of this we are not certain. 

18. It is evident, therefore that toe cannot expect to ascertain the 
vieight of either of these kinds of rays; as already remarked, our 
organs, and our instruments are too coarse for such delicate trials. 

19. I^ere is a great analogy between light and heat — they agree 
in nearly all their physical properties; but^ght produces vision and 
colors— caloric, expansion and heat. 

(a.) Laght cannot be, at all, imprisoned. — When the source from 
which it flows is intercepted, except in the ease of the solar phos- 

* Neither moriale of diver, nor a miitnre of chlorine and hydiogcD gBwi, wm 
aflbcled by the concentrated light from the burning carburetted h^roceo guei: 
but the light Trom electrized charcoal nieedily blaclcened the muriate, and exploded 
the chlorine and hydrogen, or earned them to combine quietly. — SramU. 

I The cbcmlcal eOecl probably fbllotvs the ^ame Ian i pombiy also the magnetic. 

Di^itzcdoyGoOgle 



44 HEAT OR CALOBIC. 

j^iori, it vanishes inttantly, and laaves do trace behind — all is 
darkness. 

(&.} Light can be entirely £xc/u<ied'.— Although it seema to peoe- 
tnite and enter all bodleS) it shines through none but those thai are 
called transparent or translucent. 

(e,) Heat can be partiaUj/ impriioned. — Wlien the aources from 
which it fiows are interce[»ed, ils efiects do not instantly vanish^ but 
decline nadually. 

{d.) Ekat cannot be entirely excl«ded,-~~lt makes its way, moie ot 
less rapidly, through all kinds of matter. 

EITECTS OF HEAT, OR CAI.OBIC, AND PHIKCIPAI. DIVISIONS Of 
THE SUBJECT. 

Certain effects od the form, and other properties and powers of bod- 
ies, are observed to arise from the addition and abstraction of heat. 
They may be embraced under 
I. Expaiuion, 

II. Distribution of temperature, 
ni. CoTtgelation and Itquefaction, 
IV. Vaporization and gazification, 
V. Aoturo/ evaporation, 
VI. Iffnitioa, 

Vn. Capacity for heat— Speeific Ikat, 
Vm. Cpmiwrwn. 

APPENDIX. 

The sources of heat and cold. 

I. Expansion. 

1. By expantion, u intended an iacreate of the three corporeal 
dintmnont, length, breadth and thickneat. — Contraction is of course 
the opposite of this. 

(a.) The entrance of heat into a body produces the same result, 
m r^rd to its dimensions, as tf more matter were added to it. 

(i.) The abstraction of heat gives, in this respect, the same re- 
sult, as if matter were taken from the body all aromid. 

Swelling and shrinking, then, are produced by heating and cooling. 

^c.) Tie absolute weight of a body u not altered, if the weight be 
estimated in vacuo ; but if it be weighed in any surrxiunding medi- 
um, n4>ose dena^ does not vary during the experiment, the specific 
gravity of the body will be found to change with the temperature. 

(d.) The experimeiUs are supposed to be conducted at such a 
temperature as not to produce decomposition. 

3. Bodiet in all the three states, solid, fluid and aerybrm, are 
tviiect to the lav of expansion. 

(a.) As an instance of the expanMon of solids, an iron cylinder 
neatly turned, and fitted to a gauge by which its dimension4 are meas- 
ured, answers very toeU, — Its length is EOceived betwasn two pro- 



OMzcdoyGoOgle 



HEAT OR CALORIC. 



46 



jeciions, aod ils diameter in a bole. If it fit these dimenanns tt the 
commoo temperature — it wiU be too large if made red iiot, and too 
small if cooled by ice. 

CfUndeT. Length. DUaeUr. 

«—. , , Q 



An Iron ball just fitting an iron ring so as to pass through it when 
cold, will not pass when red hot, but when cold will pass as beloce. 
— L. n. E. 

(i.) A pear shaped glass, thin at bottom, with a perforated coi^, 
contaming a kuig narrow tube, inserted into the neck — the glass be- 
ing filled with a colored fluid, exhibits strikingly the expansion and 
contraction of fluids; it is necessary only to heat and cool the ball. 

Alcohol is more expansible than water, but on account of its com- 
bustibiiity, care should be taken that ncaie of it is spilled into the 
fire ; a scale may be attached to the tube, and then die expansions 
and contractions will be very viable. The thermometer demon- 
strates the same facts. 

EXPANSION or LIQUIDS. — Dt, Horc. 

Limadt arc expanded wA«n thtir tmperaturt it raited; and tome 
Uquida are more expantible than otkert. 



OMzcdoyGoOgle 



46 HEAT OR CALORIC. 

Let two gk^ular glass vessels, whh long narmw necks, as neulr 
u possible of the same sze and shape, be supplied severally, mat 
water and alcohol, excepting the necks fromNNtoOO. Vndat 
each vessel, place equal quantities of charcoal, burning with a amilar 
degree of intensitv- The liquids in both vessels will be expanded, 
so as to rise into the necks; but the alcohol will rise higher than the 
water. — Hare. 

(c.) A retort of glass inverted with its mouth in a colored fluid 

^^\ pves out air, if the ball be heated ; and if the heat be 

^^^ withdrawn, the column of fluid ascends and occupies the 

^^\ place of the air that was expelled. A heated laidle an- 

I swers well to hold over the bulb of the retort. 

I The experiment will be more striking if the retort has 

I a very long and narrow neck, or if a tube be inserted in 

^ 13 the mouth to elongate the neck. 

■Mf A moist flaccid bladder with the neck tied, b swollen by 

■H the application of heat, and bursts if the heat be great ; 

^^h it is of course c(»)tracted when the heat b withdrawn. 

In thb experiment, hot water is a good medium for the expao^oo, 

and cold water for the contraction. 

(d.) The pynxneters described in the books of natural philosophy 
demonstrate the expansion of solids with great delicacy.* 

An excellent pyrometer has been executed by Mr. Terry, of Salem, 
Connecticut. A small iron cylinder is heated by a long thin wick 
fed by alcohol, contained in a horizontal slJtted tube, and by means of 
levers and multiplying wheels, the motion b so increased, that an in- 
dex moves rwidly over a graduated circle, and the opposite motion 
takes place mien the cylinder is cooled. Any other metal may be 
substituted. One of these instruments is m the laboratory of Yale 
College. We subjcnn a figure of a dmilar pyrometer used by Dr. 
Hare. - 

*8m WctMtar'a Humil.p. 2>; Ann. de Chim. etdePbys. T. 312, Brizuet; 
uid Jounul of BctosM, XI. S09, Oinlal, ud cspccldly ths Library of UMful 
Esowledga, Art FynmetaT. 



D,q,fzodbyGo(lg[e 



ttEAT OR CALOBIC 47 

InfltKiKt of temperature on the 
length ya metallic wire acting 
on an index throvgk intervening 
levers. 

WW represents a wire, beneath 
which is a spirit lamp, consistiDg of 
a long, narrow, hollow triangular 
vessel of sheet copper, open aJoog 
the upper angle, so as to receive 
and support a strip of thick cotUHi 
cloth, or a successioD of wicks. 
By the action of the screw at S, 
the wire is tightened ; and by its 
influence on the levers, the index 
I is raised. The spirit lamp is 
then lighted, and the wire is en- 
veloped with flame. It is of course 
heated and expanded ; and, allow- 
ing more liberty to the levers, the 
index, upheld by them, falls. 

By the action of the screw the 
wire may be again tightened, and 
the apphcation of the lamp being 
continued, will again, by a further 
expansion, cause the depression of 
the index ; so that the esperinient 
may be repeated several times in 



Since this figure was drawn, I 
have substituted for the alcohol 
lamp, the more manageable flame 
of hydrogen gas, emitted from a 
row of apertures in a pipe supplied 
by a self-regulating reservoir of 
hydrogen gas, of which an engra- 
vmg and description will be given 
in due time. 

If while the index is depressed, 
by the expansion, ice or cold 
water be appUed to the wire, a 
coniraction unmediately follows, 
so as to raise the index lo its on- 
gmal position. — Dr. Hare. 



OMzcdoyGoOgle 



48 HEAT OB CALORIC. 

3. In gmeral, different $olid or fiuid bodia expand varioiuljf, by 
the tame amount of heat, artd no aatiifactory theorem hat been dis- 
covered on thii tuigect : the facts are ascertained by experiment. 
The following metals are arranged in the order of their expansibility, 
the mott expatuible being placed first ; zinc, lead, tin, copper, bis- 
mulb, iron, steel, antimony, palladium, platinum. — Henry. 

It is said by Dr. Ure, that equal increments of heat produce equal 
degrees of expansion in metallic bodies :* and that the reverse is 
true for the decrements. 

Ttdile of expansion, by EUtcott.^ 

Gold. SHtbt. Brass. Copper. Iron. Steel. Laid. 

73" 103» 95" 89" 60" 56» 147'* 

Bv a table of Smeaton, (Mur.) zinc appears to exceed lead in ex- 
pansibility. There appears to be no relation between the density and 
expanubility of solid bodies, gold being less expansifale than brass or 
lead : but diere is a tolerably regular relation between the expansi- 
bili^ and the fusibili^; e.g. antimony, bismuth, tin, lead and zinc 
being most expannble and most fusible ; in Smeaton's table, anti- 
mony is stated as expanding less than iron, and bismuth than copper, 
but these deviations may arise from errors in the experiments.} 

4. Chuet are the tnoit expanded, and with them all airiform bod- 
itMi fiuid* are much lett expanded than gatet, and tolidt vattly leu 
tkanflaidi. 

Beneath is Mr. Dalton's table of some common liquids : the volume 
at 32' is denoted by 1 ; the expansion is for 180°, frmnSS'to 212". 
Mercury, . . . _ . .0200=y, 

Water, . . . . ^ . .0446=,'y5 

saturated with salt, - - - .0500=^ 

Sulphuric acid, - ... - .0600^7^ 
Muriatic acid, - - . - - .0600=tV 
CKl of turpentine, - - . . - .0700=tV 

Ether, .0700 = tV 

Fixed oils, .0800=f',.5 

Alcohol, .0110=j 

Niuic acid, .0110=1 

Generally the expansion of fiuids increases as we ascend the scsle. 
Mr. Dalton,^ thinks that the expansion of fluids is as the square of 
die temperature from the point of congelation or of greatest denuty. 
This is not sufSciently confirmed by experiment. || 

5. Caloric introdiued among thepartidet of bodiei it a power of 
repultion tending to produce expaiuion. 



• PUl. Tnna. 1818. I Pbil. Truis. sIviL 4SS. 

X Unrrmy, Vol. I. p. t<S, U «dili(H]. $ New lyitam of Cbcmicd niktophj. 

II Hurny, I. ITS, U edition. 



OMzcdoyGoOglc 



HEAT OB CALORIC. 49 

fa.^ Tbe antagonist power b cohe^on. 

{b.} Therefore, as regards all the three forms of matter, solid, 
fluid, and gaseous, the espanskm varies with the ratio of these two 
Iprces ; only one of which exi^ in the gases. 

6. Gases and all aerifobh bodies expand alike.* 

(a.) One body, of this doss, corresponds with one of another doss; 
«. g. carbonic acid eas with hydrogen, steam with vapw of alcohol, be. 

[b.) The same body corresponds toith itself, equal variatic»i3 of 
teiweraUire producing equal variations of volume, m difierent parts 
<^ tiie scale. 

(c.) TTk reason of this excgolton is obvious, at in aerifomt bodies 
there is no cohesion to otiercome; the power of the heat is, therefore, 
the same upon them all. 

7. Fluids e<cpand very vnequaUy. 

(a.) In general, the lower the boiling pcunt of a fluid is, the more 
it is expanded by heat, and vice versa, as is seen in ether, alcobo], 
water, and mercury. 

^6.) In general, also, the expanubilitles of liquids ar« inversely as 
their boiHi^ temperatures. — Thomson. 

{e.) In any given liquid, the expanability increases with the rise 
of temperature, and those are the most equal, whose boiling point is 
the hi^est. 

{iI.)'Tbeexpan»biiity of fluids does not follow the ratio' of the 
den^^. 

(b.) It increases very rapidly as we approach tbe baling point. 



* Mr. DallsD af Ifanchsster, (Eni;.} and Gay Limae of Pari*, aacortalud, bj 
nunicroui eipsriments, (hat (he eipanfion of til bodies, io (he (ana of air, la the 
stlD«, lor equal addidom of hea( ; and inorcorer, that (he ttfuatoaatutj one aeri- 
form body is nstrly, although not perfecdy, equable for equal addiOons of heat, in 
dlAmit parti of the ec^e. 

It waa fbnnerlj believed, that every dlflereut gu wis aOected difl^reutly by heat, 
■Dd tiblesof expanaion of the dIArent gaM* wore ei>!u(rueted, but thii varlaUm 
waa owing to the preMsee of water in Itll eiparimeiito before (luee of Dal(oD and 
Gal' Liuaac, ai toe vapor miiing with (he gas under cxaminadon, muM nece*- 

a air, Id p«<dog Iroro 21V to lOSS" become 2W. cub. in. 
luw no. utnnmuo air, " " W " 212' " IST.5 " 

100 do. water, " " do. " do. " 104.6 '* 

100 do. iron, " '■ do. " do. " 100.1 " 

The expanuoD of air ia then eight times greater (ban that of water, and that of 
water In^ five timea greater than that of in«i. The eipanaion of any one gas ap. 
parentlj mDiintihei a little as the temperature increases; it is however probable 
diM this dLSgrence. ai it is so very small, is only apparent 

Dalton informs us that the eipaneioa of 100 cubic inches^r air, from 56° to ISSJ", 
or far Om firal TTi°, was Iffl; and from 138^° to 212°, or tbe seoiiul 7Tj°. it wis 
only 1S8 : but if ^is dmrence beimputsd (o inaccuracy, we may conclude thai the 
BXpanrion is equable. Aeriform Indies expand one four hundred am! eighty third 
partirftbair volunM for eve [y degree of Fall renheit between freezing and boiling. — 
V>deHaitches.Memoira,V.MB; Th. I.8S8; andABD.deCbim. xliil. IST.and v.43. 



doy Google 



so HEAT OR CALORIC. 

8. Solidt expand very unegutdly, and at far at has ieen dUcover- 
^* /o/fow no general taw. 

9. Thert are partial exceptumt to the taw of expantion in certain 
part* of the scaie of heat, but none on the whole, for through a wide 
range of tempenture, aW bodies expand by heat and contract by 
cokl. 

(a.) SoUd iroa, bitmuth, and antmonj/, float on the surface of 
their respective fluids, formed by melting. 

Such metals and their compounds are peculiarly fitted for taking 
impressions from moulds, as by their expansion in cooling, they fiO 
every part, and copy the most delicate ramificati<His. 

(b.) The expannon in freexing it generally attributed to a kind 
of cryttallixatwn—bm mercury, and nitric and sulphuric acids coo- 
tract, although they suiter a parbal ciystalUzatioD. 

(c.) Salts generally expand in crystaUiung, and frequendy break 
the botdes cwitaining them. 

(d.) Water it the most remartuAh exertion, but It exists only 
within a limited number of degrees. 

In CDoUng, it attains its maximum of density at 40°, when it be 
gins to expand, and continues to do so as it cools below 40° ; its ex- 

Knsion is the same for any equal number of degrees above and 
Urn 40= ; e. g. at 32° and 48*. 

If water be cooled below 32° without freezing, it goes on expand- 
ing, and the same relations of density are maintained. 

Pure ice floats on water, about one eighth or one ninth of its 
volume being out, as is seen to a certain degree, in the icebergs. -j- 

(e.) The fact respecting water's being an exception from the 
law of expansion, is weD exhibited, by taking two thermometer balls 
with tubes attached, and filling one baB widi water and the other with 
alcohol ; both may be immersed in melting snow, or in freezing 
water, and the difierence will be very manifest, if the experiment be 
commenced above 40°. The alcohol will sink regularly, but the 
water at 40° will begin to rise in the tube, and will continue to rise 
till it freezes. 

(/-) fVater, in the act of feezing, expand* more than it does 
when heated from the freezing to the boiling potnt.X 



* It hn however been ucertaiDcd by Petit and DDlooRthal at high temperature*, 
■iIkIb dUttt* Id aa iocrea^ng ratio — Man. dt Ch. and P\g. Vol. T, aitd T^tmer'a 
Chan. p. 20. For a tabic of the expanaioD of Tarioui aubabncea, ace the liuer 
author lame page. 

t Ancbor-ice. la il rorm«d on Ihe bottotn Of ranning itreama, on account of lh« 



lucliUE power of itonea i 

Thia u beautifully iUuatrated, by immeTiiDg in a freezing mixture, a bail filled 

1 vraler, and bavinK a tube attached to it ; ai (ho fluid approaches freezing, and 



c.,i,=ji,G(10glc 



HEAT OR CALORIC. ^| 

The sp. ^> of water at 60° bmng assumed at 1, that of ice at 33", 
boiily.»2> 

^g.) Were it Dot for the exception above described, water would 
begin to freeze at ibe bottom of rivers and lakes. 

10. Cmat of tht expaniion of water in jretxitig, and for eight 
degrea above.f 

(a.) There can be little doubt that it is owing to crystallizatiaD, de- 
pending on corpuscular attractioD, which begins to operate even before 
COTigelation. Water in freezing, assumes a linear arrangement : lines 
of ice intersect each other at 60° and 130°; this is seen disunctly in a 
shallow freezing pond, or in a basin of water : also in snow flalces, whicli 
are usually stars of six rays, or confused bundles of prismatic crys- 
tals ; distinct crystals, prisms of sx sides, are often seen on a ceUar 
wall in winter, or in a moist bank, and boar frost is a collection of 
cjrystals of ice. 

(&.) The pardcles of water are supposed 'to be endowed wift a 
kind of polanty, which causes the volume to expand, in consequence 
of the attraction of certain points, edges or angles. 

(c.) An illustration is derived from magnetic needles thrust 
dirough corks, and thrown upc»i water ; they would arrange them- 
selves as the aqueous particles are supposed to do in crystallizing. — 
Dr. Black. 



pec 
froi 



When the freezing of water is examined by the microscope, this 
iculiarity of arrangement can be observed, the lines sbootmg out 
>m each other at an angle either of 60" or of 120°. "| 
11. Effect* of waeqtuu ejpamion of u>ater, and of iu erpamion 

infreeziw. 

(a.) Tne bursting of domestic vessels in which water freezes ; the 

flaking of the glazing from earthen vessels. 
(&.) The bursting of water pipes, of wood or metal, when not 

adequately protected. 



le giMi aicMdblg that of the wiler, i 
' lite water, in the nedfied degreea b 
nui queetian wu noweTcr fully sel 



denied by Hr. Dduo, who >ttrtbut«d it to 
md vice T< 
betneeD sy> tnd 40°. ' 



b* Dr. HoM, tnd Hr. Humy, tod tliii 
led. See the ccatrarenT kbiy italed In 
rt«, Vol. I. p. IM, tc. 

tr Chule* Bugden ucertalned that when wtter Ii prevented from freedne tt 
3>°, bybdi^keptperfactiy 11111, Ibe iraler tdll contlnuei to axpud, even lor ten 
ormoredwraeibaWltieordlnwy freezing point, and thiilneren k greater n&i; 
and if Vbt atvdai point be reduced, by mixiiig mit irith Itia water, the contracUon 
begini at about the nme distance frmn the jwfnt at whldi the putieular eolution 
iloM freeze. 

■ Hr. Dalton luceeeded (Hanchelter Memoin, v. 8T4,) In coaUng wMer down s> 
Ux without freeing, that from eipaneloa. It bad ilHn aa high ai the point to 
which it would have been railed hid It been heated to TB°. " Ita real temperature 
mnat then have been W. On Ireeilng, it darted suddenly up to 128°." 
X Murray, 2d Ed. Vol. I. p. ISS. 



DK;,lz=..,C00g[e 



§3 HEAT OR CALOBIC. 

(c) The raisiDg of pavements, and of the surface of the ground, 
like a honey comb, thus breaking and preparing it, so that the veget- 
able fibres can penetrate it. 

id.) The throwbg down, or distortion of stone wails, in moi« land. 
«.) The cracking of limber, and even of rocks, somelhnes with 
explosion, in very cold countries. 

(/) The bursting of cbsed cannon and bomb shells, when water 
is coi^ealed in them. 

Huygena burst an old cannon, and Major Williams burst bomb* 
diella at Quebec. In ose of his experiments, " an iran [Jug, 3 f 
sounds weight, was projected fiT>m a bomb-shell, to the distance of 
four hundred and seventy five feet, with a velocity of more than 
twenty feet in a sccfflid." 

(g.) Water, being confined by means of a moveable plug or stop* 
per, in a strong brass tube, three inches in diameter, raised seventy- 
four pounds, when it froze. — Soyh. 

(A.) The Fkjreniine academicians burst a hollow brass ball, one 
inch m diameter, by freesing the water with which it was filled. 
MuschenbKBck, calcutedng ir<Mn the tenacity of brass, and the thick- 
ness of the ball, inferred, diat the expansive force was equal to twen- 
ty seven thousand seven hundred and twmty pounds. 

12. But for the inequaliiy of water in contracting, jutt ftefiwe tV* 
tonedeiian, the globe would not he long kabitahie. 

ut.) There are both ascending and descending currents in water, 
while coolii^ or heating. 

(6.) In the case c^coolmg water, these currents, ^rfiile unobstruct- 
ed, tend to cool it equally. 

(c.) In consequence of die exception that has been stated, diey 
are arrested at 40°, and then die surface water does not descend any 
more. 

(d.) It remains, is cooled, and freezes, and the ice, being a bad 
conductor of heat, gready retards the freezing of the water below. 

(e.^ Thus only a few inches, or at most feet of ice are formed, 
taa tne next summer is sufficient to thaw it. 

{/■) W^ere it not for this peculiarity, Uie deep rivers and lakes in 
cold latitudes would freeze to the bottom, and therefore would never 
thaw again, as the summer would not be long enough for that pur- 
pose. 

(g.) The process would, every winter, advance farther and farther 
towards the equator, and ultimately the ocean would freeze as solid 
as stone. 

(h.) Thus, animal and vegetable l^e would be finally eTtingnithed. 

(i.) All this mischief is prevented by diis, apparently, trifling and 
really solitary exception, evidendy Instituted on purpose by the Cre- 
ator, one of whose characteristics it b, to efiect the greatest resnhs 
by the smallest means. 



OMzcdoyGoOgle 



HE&T OR CALORIC. £3 

{],) " Tbe sheet of ice which often conn the smaU seu, u well 
as the riven lud lekea, aot only preseiren a vast body of heat in the 
subjacent water, but when it Ihkws, tbe fiah are not destroyed by tbe 
cold ; for not a particle of the cold sur&ce water can descend until 
a change in the atmosphere has taken place, so as to raise the tem- 
perature of the wltole of the wUer, at least ten degi«es.* 

13. Popuiar iua of expantion and contrattion. 

(a.) Inm hovpt and tms are haUed red hot, and suddenly cooled 
to bino tbe ports of carriage wheels, of burr millsttMies, &o. 

(b.) Ciocks and watcha gam m told ieeather, owing to the con- 
ttacbon o[ the metal, and vice versa. 

A pendidwn vibrating seconds, by a change of temperature of 30" 
will alter its length about ,,V,i'part, which will change its rate of 
going eight seconds a day. (> if the ball of a penduluni vibrating 
seconds be lowered ^tk of an inch, tbe clock will loose ten secontb 
in twenty four hours. — Hen. 

(c.) The Competuation pendulum is easily explained, by a model 
or diagram ; one kind, called the gridiron peDduium, consists of bars 
of diilerent expanubilhy, and having di^rent points of support, the 
opposite expansions balancing each other. Harrison emf^yed 
three bars of steel, and two of a compound of zinc and silver, and 
they were so arranged that the expansion of tbe steel counteracted that 
of uie other metals, so that the pendulum did not aher io length. 
Graham substituted for the bob of the pendulum, a glass cyhnder 
about six inches deep, and holdbg ten or twelve pounds t^ mercury, 
the expansion of which upward, compensated for that of the steel 
paidufum rod downward. — l. u. e. 

(d.) The cracking of thick ghat, by sudden heating «r cooling, 
u omng to unequal expoTuion ; thin glass does not crack, because the 
heat makes its way through the glass so rapidly, that the internal and 
external expansion are nearly alike ; otherwise there would be a 
strain, and glass always cracks on the colder surface, whether hot 
glass is suddenlj' exposed to cold, or the reverse. 

(e.) Hxpanston and contraction, by temperature, it capahle of over- 
coming great force. 

The two side walls of a gallery at tbe Conaenaimre dea Art* et 
JtUtiera, being pressed outward by the incumbent weight, M. Molard 
perfra^ted the walls on opposite sides, and mtroduced stnmg iron 
bars, whose ends were lelt to project beyond the walls, and were 
iiimished with strong circular iron plates, fitted on so as to screw. 

The bars, being then heated, increased in length, and the plates 
now separated fiwn the wall, were screwed up so as to touch it. 
The bars, on cooling, contracted, and drew tbe waUs closer together. 

'' Parkes' Cbemieal Enays, Vol. I. p. 81. 



OMzcdoyGoOgle 



64 HEAT OR CALOBIC. 

The process being repeated, the walls were brought intn the perpen- 
dicular position, and if necessary, could hare been curved inward. 

— L. V. K. 

THERHOHETERS, COSSTIIIICTION, USE, 6lC, 

I . The coTnmon thermometer, and m<ut pyrometert, operate upon 
theprinaple of expatmon. 

(a.) The thermometer wa» probably indented bt/ Sanctorio, an 
Italian physician of the seventeenth century. His thernicxneter was 
merely a ball blown on the end of a glass tube, and inverted in a 
fluid ; it was consequently subject to the pressure of the atmosphere, 
a change in which might cause a movement of the fluid, almough 
the temperature should be stationary. This thermometer is entirely 
unfit for being used in fluids — still it is very useful, as en air ther- 
mometer, for measuring minute vaiiatiocs of temperature. 
Air TTtermometer of Sanctorio, on a large scale. 

The bulb of a mattrass is sun- 
ported, by a ruig and an uprignt 
wire, with its neck downwards, 
so as to have its orifice beneath 
the surface of the water in a smaU 
glass jar. A heated iron being 
held over the mattrass, the con- 
tained air is 30 much increased in 
bulk, that the vessel being inade- 
quate to bold it, a partid escape 
from the orifice dirough the water 
ensues. On the removal of (he 
hot iron, as the re^dual air regains 
its previous temperature, the por- 
tion expelled by the expandon is 
replaced by the water. 

If in this case the quantity of 
^r expelled be so regulated, that 
when the remaining portion re- 
turns to its previous temperature, 
the liquid rises about half way up 
the stem, or neck, the apparatus 
will consdmte an air-thermometer. For whenever the temperature 
of the external air changes, the air in the bulb of the mattrass must, 
by acquiring the same temperamre, sustain a corresponding increase 
or diminution of bulk, and consequently, in a proportionable degree, 
influence the height of the liquid in the neck. Ilits thermometer is 
very sensible and would be very accurate, but that it is influenced 



OMzcdoyGoOgle 



HEAT OR CALOmc. 



55 



liy the TsriatioDs of atmospheric pressure as well as by thennomet- 
rical changes. — Dr. Hare. 

(6.) Lalie'tdiffitentitdtkermometer. — For the ccmstrucdoD of this 
instniment, a ball b blown at each end of a glass tube bent twice at 
right angles. 

"nie tube ctMitains usually sulphuric acid colored by carmine — the 
baUs c<xitain air, which, as well as the contained fluid baa no com- 
munication with the atmosphere. 

(e.) It indUaiea only the diffmTux of tea^erature between tie tvu 
baUt. — It is very useful in delicate experiments on heat, where the 
variati<»is of temperature are minute. 

g'.) Howardt improvement of Letlie't thermotit^er. 
t. Howard of Baltimore,* has substimted ether for the sulphuric 
acid— 4he ether is boiling ^en the instrument Is sealed, and therefore 
there is a vacuum over Uie fluid, except that the space is filled with 
the vapor of ether ; this instrument is vastly more sensible than Les- 
lie's original one, and with it the heat was believed to be discovered in 
the moon's rays by Dr. Howard.f 

DIPrEKENTUI. THEBHOnCTEB. 

^^~^ This instrument wmaists of a ^ass ftibat 
tj nearly m the form of the letter U, with a bulb 
> K at each termination. In the bore of the 
' 1 tube there is some colored liquid, as for in- 
stance, sulphuric acid, alcohol, or ether. — 
Whra such an instrument is exposed to any 
■ ; general alteration of temperature in the sur- 
rounding medium, as in me case of a change 
of weather, both bulbs being equally afiected, 
there is no movement produced in die fluid ; 
but the opposite is true, when the sliditest 
ima^able calorific bfluence exclusiively af- 
fects one of the bulbs. Any small bodies, 
situated at different places in the same apart- 
ment warmed by a fire, will show a divers!^ 
of temperature, when severally applied to the 
dififerent bulbs. — Dr. Hare. 

3. CoNSTRDCTIOtl Or THE COMMON THEBHOMETEB. 

(a.) Take agloM tvbe, of unt^brm htyte, lealedatthe^ast-houte. 
— Its uniformly is aacertained by mtroducing a little mercury, and 




•Lpnd. Qmt. Bd. Jour. Vol. 8, pi. S19. 



t Am. Joar. Vol. II, («, S! 



■DMz.dDyG00g[e 



and an 



£0 HUT OB CALOBIC. 

lettiiis it pass almg the tube, frwn end to end, roeasuriog it, at short 
inteiyals, with a scale or dividers.* 

(A. j ^Itkough tie tvbe thtnUd not be quitt untform, it nay bt OiU 
tued.\ 

c.) To blow the baU, the tjutrumentt watUed are the blow pipe, 

a an eUutic gvm bottle which is useful, perhspB necvsatry, where 
the thennomster must be exact — tbat is free from air and moisture. 
We need also pliers and some bladed instrument. The f^ass ia 
melted, dnwn in two, and thus bermetrically sealed at ope end, 
while it is opened at the other by cracking it, after merkii% it with a 
file ; the end on which the ball b to be, is then rounded, by ahw- 
nately holding it in the fiame and pressing the hot glau agaust the 
Made, to accumulate as much as is needed. The bulb is next 
blown by the mouth or the elastic bottle, and this pan of (be (dera- 
tion requires a Idsd of skill which can be acquired by practtca aWe. 

U.) Tojm the baU mih mermry. 

First heal die mercury in a ladle, to drive off moisture and air ; 
filter it by making it pass through pin holes in a p^er depressed into 
a wine glass, in the form of a funnel ; next bold the ball over a spirit 
or an Argand's lamp, the open end of the tube being immersed in the 
toercuiy, turning the ball to prevent fusion or collapse, and holding it 
in the heat as long as the air continues to issue freely ; then withdraw 
it And the atQiQn>here will raise a column of mercury that will fiD 
the ball, one third or one half. Now bring the ball &^aui over the 
lamp, with the mercury exposed to the heat until it bods, when the 
metallic vapor will expel roost of the remaining air ; on withdrawing 
it from the heat, the mercurial vapor will be condensed, and the tube 
'having its open end still immersed in the mercury, the latter will rush 
in, and nearly or quits fill the ball. 

(e.) To boil the mercury, for the purpose ij/" expeUing the remain- 
d&- of the air. 

Tie a small paper frinnel to the open end of the glass tube, hav- 
iiu jiuned its edges by paste or sealing wax — throw in a small gkibule 
of^mercury to act as a valve— then boil the mercuiy, holdmg the 
tube vertically over the flame of the spirit lamp, and surroundmg the 
tube with thick folds of paper, protecung the nngers still farther by a 
glove. 

(/.) When the mercuryboils quietly, and theballi»TtadilyjUled on 
btmg vnihdravm from tMketUfVie praume thattheairit aUexpelled. 



If th« bora bevtij m 

i Ita Gnmor tbipe, when • fortSaa <^ mercury will riie 



Itottie, by tyinc it fut- 



into the tube. 



D„tiidD,GoOglc 



HEAT OR CALORIC. 57 

After die bill hu been cooling for b few minutes, the excess of 
mercury is poured out, and the column allowed to subside. 

(g-.) To try vAtther the range of the merairy wiU be comet. 

Imnierse the baU in melting ice or snow — ihe mercury should not 
sink within the ba]) — ^mm^se it in boiling water, or, which is better, 
in Seam. In this case, the mercury should not ris^ so high as the 
top of the tube and these two points, the freezing and the bdling 
should foil higher or lower according 10 the use tliat is to be made of 
the therm<Hoeter, for measuring h^h or low degrees — that is, ex- 
tremes of heat or of cold ; if intended for both, there should be 
sufficirat itNHn both abore and below these two points. 

(A.) If there be not mercury enough, warn the ball in a candle, 
and let the column, as it reaches the summit, be united to more ijuick- 
silver in a wine glass, quickly reverang and plunging the tube for that 
puniose. 

(t.) ^ there be too much nurcury, kt a little of it be erpeUed, by 
warming the ball, and then in either case, the mercury must be ad- 
justed as regards the fireezing and boiling points, by a new immer- 
^on in melting snow or ice and in steam. 

(J.) To dose the tube to eaxlade the atmotphere. 

Draw the end of the tube in two by the blow pipe, and it wilt be of 
course hermetically sealed ; then break the 6ne point so diat it may be 
merely open ; next warm the ball, so that the mercury will rise and fill 
the entire tube, and just as it is about to issue from the orifice, things 
bemg previously adjusted for that purpose, direct the blowpipe flame 
upon the pobt, and seal it; if correcdy dcNoe, the mercury will tlien roll, 
backward and forward, without breaking the column and without im- 
pediment. 

{k.) Final a^iaH»ent o^ the fixed pointM offreeziitg and boiling. 

A new exposure to the mening ice and to the steam of boiling 
water, will now give us, by inspection of the top of the mercurial 
column, the important points of freezing and boiling water, which 
must be marked on the glass by a diamond or a file. 

il.) Graduation of the Hufrtitnent.— The space, between freezing 
boiling water, is now to be divided into one hundred and eight}' 
equal parts ; freezing water wili be 32° and boihng water 212°. 

This division is arbitrary. It was adopted by Fahrenheit of Am- 
sterdam, after whom the themximeter, thus graduated, was cidled. Tlie 
of this scale indicated the greatest cold observed in Iceland, and it 
was supposed to be as great as would probably ever occur in philo- 
sophical experiments. The scale is extended above boihng water to 
any desired degree, and below 0, by numbers reck<»ied the opposite 
way, which are considered as minus degrees and marked witli the 
correspondent aritlimetical sign, while the degrees above are written 
without any sign. 



OMzcdoyGoOgle 



58 HEAT OB CALORIC. 

(m.) Other pointt utwiUi/ marked on Me teak. — Blood heat is 
■narked 98° for the human subject ; fever beat 1 12° ; the mean sum- 
mer beat of the day li^t in temperate climates,* 76°; eUier boils at 
98°; alcobol 176°; mercury 666°.f 

(».) OMer tatles uted in different amntrist. 

As the division of a ihermometrical scale is entirely aibitrary, it 
varies in di^rent countries. Id the thermometer of R6aumur freez- 
ing water is and boiling water 80°. 

In Spain and Italy, this thermcHneter is still used ; but in France, 
since the revolution, Reaumur's has been discarded, and that of Cel- 
sius adopted, under the name of thermomitre centigrade, in which 
freezing water is 0, and boiling water 100°. To reduce the degrees 
of Fahrenheit to those of the centigrade, subsUw:t 32, then multiply 
by 6 and divide the product by 9, because each degree of Cel^us 
= Sof rofFahr. 

In converting the centigrade degrees into those of Falirenheit, 
double the centigrade number, subtract j\, then add the constant 
number32. Thus, 10= cent, x2=20- ^=20-2=18 + 32 = 50°. 

To convert the degree of Fahrenheit into those of Reaumur, sub- 
tract 32°, multiply the remainder by 4 and divide the product by 9 : 
or, the reverse, that is, multiply the Reaumur degree by 9, divide by 
4 and add 33.]: 

Mr. Murray proposed another dirision of the tbermometrical scale ; 
namely, into one thousand degrees, counting from — 39°, the freezing 
point of mercury, to 672°, its supposed boiling point. The advantages 
proposed, are a more minute division, the avoiding of negative 
degreesand fractional parts, fiicf 

Therm ometrical scales are often compared, by drawing a diagram 
to exhibit them side by side, when any line drawn at right angles to 
the scale will cut the correspcmdent degrees, which may thus be read 
by inspection. 

In Russia, De Lisle'i thermfxneter has been adopted ; in tliat, 
freezing water is 150°, and boiling water or meltiog mow is ; a very 
awkward division. 

(o.) Principle of the graduation. 

This is founded upon the fact that the temperature of freezing 
water and of melting snow or ice is the same, all the world over j 
and that pure water (die pressure of the atmosphere being the some) 
boib every where at the same temperature. 

• Probabljr loo hlrfi. t Murray*. El. 6 ed. Vol, I. p. 108. 

t Becsuu thezeroorF(breDheifaO]«niiQineterliS2° lower than (hit of tbe cen- 
tigrade or Reaumur. Btlore reduction, we mu^t therefore aubtraot 33° from the 
Fahrenheit decree, or add It to th«l of Reaumur, or the cenlignde. 

^ See Murray, 2 ed. Vol. J. p. 139. 612° wia then admitted as the hoilinj; pomt 
of mercury. For oOier modes of srad nation, Me Ferg. Lect. Vol. I, p. 131, and, 
Cavallo'. Phllo*. Vol. Ill, pp. l», 20. 



OMzcdoyGoOglc 



HEAT OR CALORIC. 59 

Tbe ihenaonieter ought therefore to be graduated, when the ba- 
rometer is at the medium pressure, or a proper allowauce should be 
made for the variation,* 

[p.) Corretpotulence of thermometers. 

AU thermometers, accurately made upon these principles, will cor- 
respond, however different in size or form.f 

[a.) Choice of fittida. 

Mercury from its mobility, cleanness, beau^, nearly equable es- 
pansioD by heat, great sensibility to that agent, and the wide difier- 
ence between its boiling point, + 656°| and — 39° its freezing point, 
is generally used ^ oil is viscid and water very limited in its range, be- 
sides its unequal contraction between 40° and 32°. 

Alcohol tinged with cannine, is used for intense cold, but cannot 
be used for heats above 176°, || nor quite so high, on account of its 
unequal expansion near the bcnling point ; while in seiuibilily it is 
mucb inferior to mercury. 

(r.) ImpetfecHoru of the thermometer. 

It does not give the result instantly ; there is some kos of tempera- 
ture before the effect can be observed ; it gives no information as to 
the absolute heat, reckoning from the real zero ; it indicates only rel- 
ative heat, or heat compared with some known degree, just as marks 
may be placed on the Unks of a chain, whose terminations are con- 
cetded. We know not the be^oning or the end of heat ; but this is 
not the fault of die thermometer : the range of the thermometer is 
necessarily limited between the freezing and the boiling points of 
the fluid with which it is filled. 
(»,) Vse» of the thermometer. 

No accurate knowledge of the laws df heat could have been ob- 
labed without it ; hence the t^servations of the ancients on beat are 
of little value. 

For philosophical pmposes, it is indispensable. It is of use to a 
physician, in observing the phenomena of disease, as of fever and 
inflammation and in experiments on animal life, Su;. 

■SeePhU.TnD*. 1777, fin- the minor the Royil Scwiety; aln Phil. Tnat. abr. 
IT. 1. Ibr Newtoa'a rulea. See alto Mardne, on heat and thennometera, amd Enr- 
lUh Joor. SdeDce, Vol. VII. p. IBS, Chettlier Landriaoi. ^ 

t For varioiu ctuaei of dlaagreement, tee Cordier'* Eaaay on T«np. of the Earth 
p. 14S. 



Thij pcfait la atated bv Irvine to be 673*' of Fahr. (Murrav, 1. IBS.) ; 883° Petit 

DuIodk; efts" Crightoii, G' '"- ■'--■ " -- - 

Vol. I. p. m. 



and DuIodk; SM" Crlgtibiii, Glaagow; neaji of the three, M3j°.— ifm. 9f& td 
Vol. I. f. 101. 
\ Itihoilingpoliitia higher thut that of anv pennaoeDt fluid, and ita freediur 

" ■ * " ' " '■ " ' hoi aiid ether. Betwaea Sa* and 212^ 

imperatures Its 
Imila, tba aam* 



nno, and therafcre tiiere ia no practical error. — Z\ir(Mr, p. S8. 
fl This li Itt boHIng point when ita apedfie gnvity U 820, nater being II 



OMzcdoyGoOgle 



60 H£AT OR CALORIC. 

For medical and chemical punxMes, the bulb ibould be na&ed, 
with a part of the tube projecting below the scale. 

It has important uses to a gardener, as in observing the temperature 
in hot houses, and the heat adapted to sowing and plantiog. 

It is useful at sea, as in the gulf stream where the water is warmer 
than the mean ; also in approaching land, and in coming on soundings 
or shoals, and near icebergs, where the temperature alwayi changes 
and grows colder.* 

It is important to travellers in observmg cUraales ; lo man]r artists 
in regulating their processes, and to all persons in observing the weath- 
er, and in regulating the heat in their apartments, m baths, 8ic. 

{t.) yanetiea qf thermometert. — The principal are — the aelf-re- 
nstering, of which Six's is the most remarkable ; the air, the ofint, 
uie water, and the mercurial thermometer. WoUaston's for measur- 
ing heights, b a very delicate instrument, vhkh will be mentioned 
agaui. 

Thermometers are made of various form and graduatioD, somedmes 
with xiass scales for immersion in acids, with naked balls, &c. 'niey 
are otten in pendent boxes, or in cases which shut for travelling. 
L(Aoratorif thermometer. 



" The thermometers used in laboratories, are 
usually constructed so as to have a portion of the 
wood, or metal, which defends them finm inju- 
ry, and receives the graduation, to move upon a 
hinge, as in the accompanying figure. 

" This enables the operator to plunge the bulb 
into fluids, witliout introducing the wood or met- 
al, which would often be detrimental either to 
the process or to the mstniment, if not to both. 

" The scale is kept straight, by a little bolt on 
the back of it, when the thermometer is not in 
use." — Dr. Hare. 



■ The lhermaineb<r ia regularly uied oa board oT ships of wtr, and id Indicidon* 
we recorded once or twice » d»y. Not only doea the water always grow colder on 
comii^ upon Knindtngs, t>ut gener^ly the air grows colder as we approach 1mi<I. 
(See Dr. John Davy's atiBerv*liof» !■> tbe lotimals.) 



OMzcdoyGoOgle 



HBAT OK CAUnUC. 61 

Difference between an air tkermometer and a d^peretUial iherwta- 
mefer, Ulvttrated upon a large teak. 

" The adjfWimg 6gure represents an in- 
strument, which acts tis an air thermonie- 
ter, when the stopple S is remored from 
the tubulure kt the conical recipient R ; 
because in that case, whenerer tne densi- 
ty <^ the atmosphere raries either from 
changes in temperature, or barornetric 
pressure, the extent of the akersa<»i 
wiU be indicated bjr an increase or di- 
minution of the space occupied I7 die 
ur in the bulb B, and of course by & 
corresponding movement of the liquid 
in the stem T. But when the stopple 
is in. its place, the air cannot, within 
either cavity of the instrument, be af- 
fected by changes in atmospheric pres- 
sure : nor can changes of temperature, 
which operate equably on both cavities, 
produce any movement in the liquid which 
separates them. Hence, under these dr- 
istances, the instrument is competent 
to act only as a difilerential thermometer." 
Dr. Hare. 
St^-regiitering thermometer. 

" This figure represents a self-registering 
thermometer." 

** It comprises necessarily a mercurial and a 
spirit thermometer, which differ from those or- 
dinarily used, in having their stems horizontal, 
and their bores round, also large enough to ad- 
mit a cylinder of enamel, in the bore of the 
spirit Aermometer, and a cylinder of steel, in 
the bore of the mercurial diermometer. Both 
the cylinder of enamel and that of steel, must 
be as nearly of the same diameters with the 
perforations, in which they are respectively sit- 
uated, as is consistent with their moving freely, 
in obedience to gravity, or any gentle impulse." 
" In order to prepare the instrument for use, ii 
must be held in suchia situation, as that the ens- 
met may subside as near to the end of the al- 
coholic column as posEdble, yet still r 
within this Uquid." 





DMz.dDyG00t^[c 



62 HEAT OB CALORIC. 

" Hie steel must be in craitact with the tnerciny, but not u kU m^^ 
ged in it." 

" Under theae circumstances, if, in cmsequence of its expansion, 
by beat, the mercury advance into die tube, the steel mores before 
it ; but should the mercury redre, during the absence of the observer, 
the steel does not retire with it. Hence, the maximum of tempera- 
ture, in the interim, is discovered by noting the graduation opposite 
the end of the cylinder nearest the mercury. The minimum of tem- 
perature is registered by the enamel, which retreats with the alcobd 
when h contracts ; but, when it expands, does not advance with it 
The enamel must retire with the dcohd, since it lies at its margin, 
and cannot remain unmoved in the absence of any force competent 
to extricate it &om a liquid, towards which it exercises some attrac- 
tion. But, when an oppodte movement takes place, which does not 
render its extricatitMi mmi the liquid necessary, to its being staticmBiy, 
the enamel does not accompany the alc^iol. Hence the minimum 
of temperature, which may have intervened during the absence of 
the observer, is discovered, by ascenaining die degree oppoaite the 
end of the enamel nearest to the end of the oJumn of tucobcd." — 
Dr. Bare. 

3. WEDdWOOn's PTROMETEa. 

(a.) 7^ iiufrumetU it canttmcted on a different priricipU from 
that of other pyromelert and thermometers ; still it affords no ex- 
ception or contradiction to the law of expansion ; it depends on a 
permanent contraction of certain cylinders of clay in consequence 
of the application of heat, which operates by expellii^ water and 
eventually by cau^g a chemical union of the alumina and silex of 
the clay piecesi and an approximation to the condition of porcelain. 

(b.) 2»e cylindricai pteces of day,* are modelled and thrust 
through a moud, a little flattened on one side — baked gently to ex- 
pel sir and moisture, made to fit at between two conreigmg rules 
of brass, twenty four inches long, distant at the wider end .5 of an 
inch, and .3 at the other, and screwed to a brass plate, divided into 
two hundred and forty equal parts or degrees, each of which is there* 
fore one tenth of an inch. 

(c.) Zero of the icale it 1077 J of Fahrenheit, and indicates a full 
red heat, visible in the day light. 

(d.) Each Wedgwood degree correspondi to 130° Fahr. 

(e.) To convert Wedgwood direct into Fahrenheit degrees; 

Muldply the Fahrenheit degree by 130 and add 1077.5 ; thus the 
two may be compared. 



OMzcdoyGoOgle 



HEAT OR CALORIC. 63 

[f.) Wedgwood origwd pieces are not now attainahle, — at least 
not the same that Mr. Wedgwood used, the bed of clay being ex- 
hausted. 

Mr. Wedgwood connected his pyrometer with the common ther- 
mometer, by the expan^on of cylindricBl pieces of diver measured 
in a groove of eartbern ware similar to his scale. 

Hem^ states that the greatest degree of heat observed was 1 B5° 
W. =25127 Faia.— Appendix. 

(g.) Wedgwood'i pyrometer it the only one for meaturing highjvr- 
naceheat. 

(A.) The highest degree of Wedgwood corresponds to 32.277 
Fahr. 

(t.) The greatest range of observatitxis made by Fahrenheit's ther- 
mometer does not exceed the ,'j part of that Bscertained by Wedg- 
wood. 

There is no measure for the highest heat ; Dr. Hare's compound 
blow pipe readily melts all porcelains and other earthy composidoos, 
more re&actoiy than Wedgwood's clay pieces. 

(j.) ^tifiaal day piece* may be made, but little dependence it 
nmophiced vpon tkete earthy compontiont for pyrometertf for, Sir J. 
Hall has ascertained, thu a raitd beat long continued, has a dmilar 
effect in causing them to contract, with a sudden and violent one. 
Mr. Faraday* con^ders Daniell's pyrometer as the best.f 

II. DlSTKIBDTION or TkmPEBATUBB AND CoiUCUIIlCATION OF 

Heat. 

1. CaLOBIC constantly tends to an E^UILIBUUlt. 

Tbis tendency is never efiectual on a great scale, because of the 
operation of numerous disturbing causes; the equilibrium is, to a 
good degree, attainable in a limited and ccn&ied space, as in a close 
room ;{ in such a situation, a thousand bodies of different temperaturo 
will ultimately assume nearly or quite the same temperature, and the 
thermometer, when applied to them severally, ascertains the fact. 

(a.) Radiation and actual contact both contribute to the t^ct, — 
At nigh temperatures, radiation is the most effectual, but actual contact 
is most efficient at low degrees of heat. 

(&.) Caloric radtatet throvgh a vacuum. 

'Therefore a medium is not necessary to its transmisaon, a body in 
avBCuum cools about half as fast as in the air. 

2. The atmosphere is vest vme(),oau.t heated. 



• Chsm. Muii*. PR. 146. 

f See Qnuterfj Jour, of 8d. XI. SOS. 

; Etui id inch drcunutaDcm Ihera li «nerallf ■ HDrible difference betneeti 
Uie lemperatnra ot (he floor ud sf the gbUue of tbe room. See Ur. Hu-eui Bull's 
Acconnt of M> eipecimMli OQ the bMt (fit&d t>y dlfleraDl kinds oT fual. 



OMzcdoyGoOgle 



fH HEAT OB CAU>BIC. 

It is moBt heated at die eulh's surface, and in a rapidly decreuing 
series, (perhaps eveo a geometrical one,) as we ascend. 

(a.) lAne of perpetual congelation. 

At a certain elevation in the aunosphera, it freeEes in some part of 
ereiy day in the year ; and at a height not less thu) threa nules, it 
would freeze water, at all limes, in every climate, thftt lurrounds our 
earth. 

(b.) Heigkl of the line of perpetual congelation. 

At the equator il is 1 6577 (eet, as ascertained by Mr. Bauguer by 
actual observation on Pinchinca, one of the peaks of the Andes ; in 
lu. 45° it is 9016 feet; in )at. 70° it is 1557 feet; in lat. 80° it is 
120 feet ; and at the pole, it is nearly coincident with the earth's sur- 
face. Most of these numbers were obtained by calculatitHi, upon a 
prindple explained hy Mr. Kirwan.* 

(c.) CauiM of the increase of cold in the higher regimu of (heat' 
motphere. — The sun's rays do not heat the air miije passing through it; 
they beat the earth first, and this heats the air by actual c(»itacL 
As we ascend, the capacity of the air iac heat increases in an arith- 
metical, while its density dinuDiahes in a geometrical ratio ; hmce, il 
requires more heat to {Htxluce a given temperaun^. Among the 
minor causes, may be mentioned the absence, in a great degree at high 
elevations, of animal and vegetable life, of fermentation, of combus- 
tion, respiration and putrefaction, all of which generate beat. 

(d.) anoxD is in every climate, perpetual on high momttaivs. — 
Because their tops pierce the regions of perpetual cold, and snow 
once remaining me year round, will continue ; the sun cannot, in e 
second summer, melt what it has failed to melt in a first. 

Any commencement of warming there, by the sun's rays, belbre the 
first snow fell, would bare been very iransieDt, because ventilatirai 
would soon begin, as the lateral columns of air, not over the moun- 
tain ridges or top, would not be heated at that eleratiu), aod b^ng 
heavier would rush in upon them on all sides, and therefore the sur- 
fece there would never become warm. 

(e.) Effect of the winds on the term of perpetual cold. 
They raise it by mingling warm air with the cold ; if there were 
no winds, perpetual cold would no where, be over a mile above the 
earth's surface. — Dr. Black's Lectures. 

' The mean temperatura St the equator md in say pwillal or latitude, belDguccr- 
lllned by observation, we lake liiedilfereQce belweeneactiorthaae iwonumtwr* tad 
the freezing pdnt; (be lieSgbl of the term of perpetual eonnUtion at the eijualiir 
is aisD uccrt^aed by atttervation ; Uie numt>er to be foDnd, I* the balghl of the 
game term in any parallel of latitude; the proportion will be, u BV &t° mean 
temp. — S2° ='SZ) (he numlferBt tbe equator, il toIS.STT (he height of Ue term of 
perpBtual congelatioii thsre, to ia 40°. S the number at 3H° of iat (TS°.S oiwu temp. 
—^a" = M°.8 = thit^ term,) to 13.073 the heitcht ot die term of CMi|platioii there, 
and w) fiir any other lalitude. Due allonaoco murt of coune be nude, for the el- 
evation of the country above the ava, for i(a mountalnoaa or level lurftce and for jt- 
riaua other cauMi, which would inSuenee it* climate. 



.yGcxiglc 



HEAT OS CALORIC. 65 

It results therefore, from all our knowledge, that our atmosphere 
K, throughout its whole extent, in every climate, and io every season, 
B re^on of unmitigated cold, exceptiug the small spheroidal ponioa 
wUch ia nearest to the earth— distant from it less than three miles in 
the torrid climates ; rapidly approaching the earth in the other climates, 
and almost touching it at the poles. Therefore, between the planets 
and in space generally,* it is probable, that the temperature is very low. 

3. CoMXUKIC&TION OF HEAl^-ComiDCTION, RlDIATIOH. 

A. The name of Conduction is given to the slow passage of 
Caloric through the substance of bodies and to its cause ; that of 
Radiation, to the instantaneous passage, from surfaces, and through 
a transparent medium, and also to the cause of it. 

(bA The conducting powert of bodiet are widely different- — If a 
cyhnder of metal and one of glass, of tlie same dze, be held by the fin- 
gers in the fire, the metal will feel hot, and perhaps become intolera- 
Ue to the touch, while the glass will communicate Uttle or no heat. 

Those bodies which in their ordinary state feel coldest to the touch, 
are the best conductors, and nee versa ; hence, some bodies are sup- 
posed to be naturally cold, as for instance, marble; others naturaUy 
warm, aa woollen ; but this is an error. They may have the same tem- 
perature by the thermometer, and still impart very difierent sensations, 
as will be perceived by laying one hand on fire brick and the other 
on trapf rock ; or more strikingly, one hand on woollen, and the other 
on metal, both being of the same temperature by the thermometer. 

When we apply flie hand to various (Ejects in our apartment — " the 
carpel will feel nearly as warm as cur body ; our book will feel 
cold, the table cold, the marble chimney piece colder, and the can- 
dlestick colder still, yet, a thermometer applied to them will stand m 
all at nearly the same elevation. They are all colder than the hand ; 
but diose that carry away caloric most rapidly, excite the strmgest 
somtHMis of cold. I 

(c.) Bodiet, taken m daatet, conduct better, the more dente they 
are, and vice verta. 

Metals conduct better than any other bodies, but thne is a difier- 
encfl among them, for mstance, copper and tin conduct belter than 
lead and platina. 

The following metals conduct heat, neariy in the order in which 
ther are named. 

silver, Gold, Copper, lln,— nearly equal. 

Phnina, froa, Steel, Lead, — much inferior to the others. 

(d.) Bodiet conduct heat tnorte, the more tpongy and divided their 
parts are. 

' Except peit^MDeir Uielannmenible luns- 

t Or any ^one ; — tnp ii her« meDtioned, beciute it la > ven good coodaclor of 
llicliM. ( Tumer't Chemialrjp, pt. II, firMEdiUon. 

9 



OMzcdoyGoOgle 



66 HEAT OR CALOBIC. 

Iran filings are worse conductors than an iron bar of tbe saiM 
weight ; saw dust is worse than the solid wood. — Rmt^ord. The 
cause [vobably is the interventioD of air between then- parts ; air bung 
a very bad conductor. 

(e.) Stona are nevt to metala. 

Ciystalline stones conduct better than mechanical aggregates, e. g. 
trap better than sandstone ; the difference is evident to the touch, 
and it appears also, from their widely di^rent power of ctmdensing 
the atmospherical vapor ; a trap rock will be wet Irom this cause, 
while one of sandstone will be dry. 

Earth said sand conduct worse than stones. At the siege of Gib- 
raltar, in the American war, red hot balls were carried bma the fur- 
naces to tiie bastions, in wooden wheelbarrows, by merely placmg 
a layer of sand beneath them. 

(f.) Bricks an worse eonductort than itottet. 

Because they are full of pores containing air ; they are used to im- 
pede the escape of heat, as in the Ibing of chemical furnaces of iron,* 
wliich, while they are melting brass or cast irm within, can be safely 
touched by the hand without. 

A hot bricit or plank, wrapped in flannel, retains its heat a long time ; 
it is used for wanning the feet, in winter travelling, and in sickness. 

(f .) Glau u a very bad conductor. 

When thick, it cracks &om sudden heating or cooling, but, if ihin, 
it bears sudden changes of temperature veiy well. The reason is, 
that being a bad conductor, when one side is hot, it swells, and the 
colder sine b strained, and often gives way. 

(h.) Dry wood it a bad conductor. 

Hence, it is used for handles of metaUic instruments, as of ladles, 
soldering irons, tea and cofiee pots, gridirons,f &c. It is also a bad 
conductor of electricity. " Common bone, whale bone, ivory and 
porcelain," are very imperfect conductors, especially when compar- 
ed with metals. 

(i.) Charcoalit a very bad conductor. — Ii may be held by Uie fin- 
gers, within an mch or less, of the part which is red hot ; it is used 
in wine coolers, with double sides, to prevent the entrance of heat, 
and it is mixed with clay and other materials for bricks and crucibles. 

(y.) Feathen, tilk, wool, hair, and down, are itiU worse con- 
ductors. — Hence they are so efiectual in preser^g animal beat, both 
in the animals naturally invested with them, and in the human race 
who wear them for clothes. They are not naturally warm, but pre- 



* And ia tho iron funucM now u*ed [n lbi> country, for hurning inlhracile coal. 

1 WorMeJ, being m very bad conductor, woikinen who have ocosian tc handie 
toba'aiKe* which are piiber hotter or colder than ia agreeable, frequently wear 
glove* made of tbia sobatance. — l. v, e. 

At Walliogford, Con. pewter tea pola are now made, with hollow metallie bandlea, 
and they do not often become ineonrenienily hot, because they contain impriaoDcd dr. 



OMzcdoyGoOgle 



HEAT OS CALORIC. 07 

serve our animal beat from esca^nng. Loose garments are wanner 
than those that are tight, because they imprison the air, and tbe same 
weight of clothing, in two or more thicknesses, is warmer than in one ; 
hence the advantage of lining and quilting, as in comfortables,* dowa 
coverlets, Szc. 

The finer the fibres, the more efiectual they are ; therefore an- 
imals are provided with fiir which is finest in the coldest countries, 
■nd in winter it is finer than in summer ; in aquatic birds and am- 
plubia, die fijr and feathers are finer than in die terrestrial races. 
Fiae wooled sheep would, in torrid climates, become coarse wooled. 
Some covering of this nature is necessary even in hot climates, to 
protect animus from the copious dews aad nuns, and other atmos- 
pherical changes. 

{k.) Ice it a bad condvetor tnd tTWvt itill teorte. — Hence ice 
retards the congelation of die water bebw; snow protects the 
grass and grain from destruction by severe cold ; it diHers from ice 
because it imprisons air in its caviues. When the air in Siberia was 
— 70°, the earth under the snow was only 32°. Snow huts or holes 
so often used by travellers in cold countries, as in the north western 
repota of America,-|- are very warm. 

(L.) FluIDs| ABE WORSE CONOTTCTOBS THAN AMY SOLIDS. 

The common impres^ns on llus subject are entneous ; fluids 
are usually heated at oottom, and the change of specific gravity throws 
them into currents ; warm currents Bow upward and cold down- 
ward, and thus the heat is soon diSused. " If a thermometer be 
placed at the bottom and another at the top of a tall jar, the h^at be- 
ing applied below, the upper one will begm to rise almost as soon as 
the lower." — Tamer. 

Heat, applied at the surface, travels downward very slowly. Mr. 
Murra;^ provided a cylindrical vessel of ice ;% be froze a thermometer 
in at ri^t angles to the side, and near the top, filled the vessel with 
oil and applied heat on the surface ; there was no conducting pow- 
er in the sidea,|| but the thermometer proved that the heat did travel 
down, although with extreme tardiness : therefore fluids are not non 
conductors, but only very bad conductws. 

In solids, the particles are staoonary or only recede from each 
other, and the heat travels ; in fluids, their own particles travel and 
transport the heat. 

(M.) Gases, air, tapoks, and au. aeriform fluids, are the 

WORST conductors KNOWN. 

* A ouaegiTeD in tbU country, to ■ bed caveriDgDuds io tba mannerdaKribedin 
(be test. tCspUln Parry, and Am. Jour. Vol. Xill, p. 381, 

} Except mercury and meheil melals generally. 

% NicboUoD'a Journal, Svo. Series, Vol. I, p. 241. 

q Ice iiaconductor, aldioagbabadoae, mall temperature! belon 82^; Mitm«l(t 
•t that degree, it IbltoiTB that 10 tblg experloieut, any heal derived Irolll the hot fluU, 
would fpi oDty to melt the \cr, but wmild not trarel doivn lu lidea. 



OMzcdoyGoOgle 



68 nfiAT OR CALORIC. 

Here again the common impressioiiB are emaeoua. Air is com' 
monly used to cool bodies, but it is air b motion, not air at rest. Air 
in motion cools hot bodies rapidly, because new particles come every 
moment into conUct with the heated body. Air confined, impedes 
the progress of heat more than any other body, because it is. among 
the very worst of conductors. 

Double windows, double walls, iitrred* walls, sfl contribule very 
much to keep houses warm in winter and cool in summer, because 
ihe parallel surfaces imprison the air between them. 

(n. ) Change of temperature initantly duturb* the ttaiiad preaiure 
of the air andproducet cvrrentt. — A commcn fire, a lamp, a candle^ 
and all furnaces, are examples. 

Wlien the fire is active, diere are opposite currents in a warm room, 
of cold air along the floor, and of warm air along the ceiling. The 
currents divide at an open door ; hot air passes out above, and ct^ 
air blows in below, as may be seen by placing the flame of a candle in 
the door ; above, it will point outward ; below, inward, and at an in- 
termediate p(Hnt, it will be perpendtcidar ; or, three candles may b» 
used at the same time, and the efilects will be as stated abore : the 
hotter the room and Ihe colder the external air, the more striking wiO 
be the eflect. 

(o.) The bett air for rupiration tt luwdty along the floor. — Peo- 
ple falling from audbcation, in had air, often recover on reachii^ the 
noor-; a principal, although not perhapstlie sole reason, is, because the 
deadly gases and vapors, if not rpec^uaUtf lighter than air, are usually 
temporarily so from their rarefaction, as they are commonly produced 
eillier by respirationf or combustion. A life preserver used in fires, 
is worn on the head, and a projecting flexible tube descends like an el- 
ephant's proboscis, so that the orifice or Hiout touches the floor, and 
dius the wearer breathes, it may be, tolerable air, while that which 
surrounds iiis head, would, if inspired, be noxious or perhaps fatal. 

(p.) The current of a (Jiimney and of common wind*, atvett at 
monsoons, trade, \oindi, and even hurricanet and tomadoi, dependi on 
the ascent of air rare/Ud by heat. — Warm air, that is to say, l^btei 
air is forced upward by colder, or in other words, by heavier air. 

The monsoons of India are produced by the heating of the earth, 
and consequently of the air, by the sun, during his visit to the northern 
tropic : Ihe colder air, from the ocean consequently rushes in to restore 



* Furred, » lertn applied by llie builders Id an interior «al] in a nooe or brick 
houK, lud not Upon I'lenolid matciial.bul iipoD latli, which are nailed la perpendieU' 
tar (tript a( boirdi or plank, *nd lliese B^in ID billets of wood laid in the mHOnry ; 
there is then a (pace filled wilh impriuned air, 

I In bed rooma, cnpecially iii cold tveather, carbonic acid gn, flowiD|; rarefied 
from a hal aoutce, may aflarw ard> becocne to cliilled, u to (all and prevail mOHt near 
Ibe floor ; a pin of coaii or erei) a lamp or a raodie may In thii manner, e^cially 
In k tnall room, without an Dpeo chimney, produce BDoiioaiatntoiplMT*. 



D„tiidD,Googlc 



HEAT OR CALORIC. (9 

tbe equiUbrium : during his passage to the southeni tropic, die process is 
reversed, and the wind blows, lor six months, the other way. 

Sea breezes by day, and by night, io hot climates, and in hot 
weather in temperate climates, depend uptxi the same principle. 
The trade winds are caused by the tendency of the cold currents ID 
restore the pressure, occasioned by the rarefactitm of the air, within 
the tropics, from the perpetual presence of tbe sun in that regiMi. 
Hence, the currents wnicn the atmosphere pushes in, from the nonb 
east and the south east, are, at the equator, blended into one, which 
Ibllowa the apparent course of the «in. The heated air which rises, 
is in the mean time difiijsed over the upper regions of the atmosphere, 
flows north and south, is chilled ,and ccmdensed, and faUs in the tem- 
perate and polar regions, to zo through the same round again.* 

fa.) Currenti upward ana doionward, both in gros* and omol 
JUitat, prodvee a vatt and lalutary ^ect on the comort of the globe. 

The warm ocean imparts its beat to the chilled land, of tbe polar 
regions, and tbe hot land of the tropical countries gives its heat to the 
water of the cool ocean ; the monsoons and trade winds and commoa 
winds produce a ^milar efiect in the atmosphere, f 

WiUHHit currents, tbe atmosphere would bectHse fatally hot, in tor- 
rid, and fatally cold in frigid climates; and similar inequalities in tbe 
ocean and other great waters would be deadly to the aquatic animals. 

(R.) Radiation of hkat is its {apparently) iNSXAHTANXona 

PASSAGE THBOCSH TRANS PARENT MEDIA. 

We can perceive no progress, and therefore regard the passage as- 
instantaneous : there can be ao reasonable doubt that it passes as ra- 
pidly as light 

(».) Calorie or heat radiatta Jrom the mm, Jrom fret, and volca~ 
not, and probably from all bodiet.—Al\ our experience confirms this 
statement, and particular experiments to prove it will be menticaied 
hereafter. 

((.) Solar heat radiates more or leu, through all trannarmt 
meoui, wh^her tolid, fluid or aerial, and gener^y without heating 
them materially. I 

(it.) Culinary, or artificial heat radiatei otUy through air, and 
other aerial jlutdi, and not through tramniarent toUdt, or trantpa- 
renl groat ftuida, at toater, alcohol, fyc. — ^Tbe cause of this difference 
is not known. 

(tr.) T%e Irantparent bodies throi^h which artificial heat doet not 

* S«a Dt^ Hire'i ctMV on the nles of the AtlulUc Btatei of N. Am.Am. Joar. 
Vd. V, p. «6a. 

I Murray, 8d Edit Tol. I, p. 276. 

t The lower reglow of ihe ilr woatd tw quite u cold u the upper, did they not 
receive beat Irom tiw enrth. 

\ Tliere is > dtflenuce in (hia rsipect, uncnig iMdli ; wtter ureal* ibout half tlie 
rays, tod ilMibol msro than half, end of count tieil to icqalred by the** flnldi, 



DK;,iz=..,'CoOt^[c 



70 HEAT OR CALORIC. 

radiate art heated by UyhMtbey deme^alaheM bom the sola njSf 
which peimeate them euaiy. 

For the most important facts respecting the radiation of beat, see 
the section on the nature of heat and light. 

A few facts may be added here. 

(u.) Poluked iwfaeu, of all hodiet that are not trafuparent, rt- 
jtect radiant tolar heat, and do not transmit it.* 

{x.\ Calorie not only radiatet Jreely in a vacuum, f bvt it ia not 
inpeaed by current! or mitaiion <y the oir.— Winds do am disturb 
s^isbine, and the solar focus is equally distinct and powerful, in a 
inndy as in a stiU day. Bellows blowing across a current of radiant 
culinary heat, do not divert the rays. 

(T.) Sttifaee hai a great effect on the rotation and reception of 
heat independently of the nainre of the material. 

Black| and rou^ surfaces, radiate and receive heat the best y 
bright and poUahed surfaces, the worst. Glass, however, although 
naturally polished, radiates and receives beat veir well, and so do 
paper, akm, and animal membrane ; the taner radiates and receives 
twenty- five times as powerfully as polished metal. 

(z.J The radiating and a&$orhvi>g poaert are alike a/nd equal; 
but the radiatif^ and refleeting powers are directly opposed, and 
are invertely at eatA other. — In a cubical vessel of tin, one of whose 
■ides was bkckened, another papered, and another gkuied, the radi- 
ation was in the following proportion-— 

imm the black side, ... 100° 

" " papered, . - - . 98° 
« " glazed, - - - - 90O 

" " oright metallic, ... IS" Ledie. 

{aa.) TAe thermometer indicate* more or let of heat, aeeording at 
tit turfaee it blackened, covered with tinfoil or other good reflector, 
or itinitt nalvrcd »tate.-~FoT a comparative result, it should be at 
the same temperature, in the beghuiing of difierent experiments. 

[bb.) AU mirrort Uae their poteer of reflecting heat ifbladcened — 

1 become heated. ^-G\asa mirrors, not reflectmg cuUnary heat, do 
reflect it, if covered with tin foil. 

'IiiDrdirlhitttiliihaulilbe ttrietlylrue, Ae nlidi muit be nippoted lobe ccr- 
/MtIy«no(rth,of whlcfa we have perhap* no eiBinples. Scralched meUlUe nir&cas 
ncelvG and emit more heat, if tne scrolehes cnn> one uutlier, than if they are 
parallel ; the diBerence U atlKbuled to the fonuatian of pojoto, by Ihs iotenectiaa, 
through which poiDti, the beat more readily panes. 

t A> aMerlaloed by Pictet aitd Runifbrd. In the experimenli of the latterit per- 
Taded the TorricelliaTi vacauD]. BIr Humphrey Davy found that a Ihermometer 
wia heated by radiattoD, from charcoal, ignited by gafraDkin la a vacuum, three 
tiiUM w much aa it wookt have beeo in £e air ; tbere being no cooiiDg efftct ftnm, 

X Dr. Turner douliti whether colar baa any effect on the abeorptlon of heat nnlen 
the lalter b accompanied by l^t, in which case he ralla ft lomliMM calorie ; but 
then he Bllnw« that the effiirtit great. 



{bb 
and b 



OMzcdoyGoOgle 



HKAT OB CALOSIC. 



Tl 



PRACTICAL ^DESTIOKS. 

{ee.\ Why are black* dothet hotter in the summer and in the tun, 
than i» the mnter and in the shade ? — In order to settle this ques- 
tion, it is necessary to ask another, that is, in what circumstances will 
the absorption exceed the radiation of heat ? This will plainly be in 
the summer, and the reverse wiU be true in the winter. 

(dd.) Why do black people endure heat belter, and cold icorte, than 
u^tie peopU 7 — ^Tbe answer depends on the same cause, takii^ into 
view tne average animal temperature. 

(ee.) Why ihmdd steam, which we vrith not to condeme, he con- 
veyed in bright tnies, and vice versa ? — Because such surfaces radi- 
ate heat badly. 

(ff.) Why does a common roUed iron stove pipe diffuse heat bet- 
ter than a bright tinned one ? — Because its surface is rough, and 
therefore radiates heat powerfully. f 

(gg-) Why does water keep hot longer in a bright polished vessel 
than in a dark and rough one ?J — The answer is the same as in ee. 

(hh.) Why does water become heated rapidly in a rough iron 
kettU, and slowly or not at (Ul in one of hnght copper 7 — The 
imswer is the same as in^ reception being substituted tor radiation. 

(ti.) Why would an earthem ware tube, when gilded, preserve 
steam longer uncondcTued, than the same tube vrtth Us natural sur- 
face, or than bright tinned iron? — Because the substance is a bad 
conductOT, and the surface a bad radiator. 

{j}-) Why does snow melt rapttUy where the dirt is throvm upon 
or mixed with it, at tn the travelled path, and dovHy, or not at all, 

* QuerB, (commiuiieited — )" Are black clothe*, when worn la the ahade during 
summer, warmer or cooler than white clothee In the sime drcumiUnceii I" The 
■Ditrer will depend on the radiating and rnceiTlag power of the lur&cet, wtd on the 
temperature of the air, compared with thai of Ibe body. 
i Id neither of these csieB, i« the final cauae imlgDBd ; It a unknown. 

t Experiment in Yale Cotlece Laboratory, Nov. lOth. 1838 A blackeasd and a 

__ii_L.j — i^.- of plated tin otthe same fonn and size, being filled with water at 
I of cooling were u ii^lows. 

Accnmulatlnf 



Blackened Canirter coded 




Polished Can! 


in the lit] 2 uiD 


utee. 


ID" 


In the 1st 12 


•■ •' 2d 12 






" " 2d la 


" '■ >d 12 






■■ " Sd 12 


" ■• 4th 13 






" " 4th 12 


" •* Slhia 






" •• Sthl2 


" " «thl2 






" « 6tbl2 


" ■' 7th 12 






■< " 7ihl2 


" " 8tlil2 






" '■ BthlS 



M mln. 61° M mlo. 

In one luttir and thirty six mutulea, thebtaeteitedcanultr ccoled 61°, during wbleU 
Unw the peUshed ant cooled hut 85°. (At two hours from the eompletion of the 
above •iperiments, tIc. three bouiaand tbirt; six minutei fima the eommencemeot, 
the water in the polUbcd canister was itlll 20° warmer than in Oie blackened one.) 



OMzcdoyGoOgle 



72 HEAT OB CAUHUC, 

wAere it it clean, aiuj e^edallv if glased, bt/jrozen raiai — Because 
snow is B good reflector, and (fin, iroiii its rough dark surface, absorbs 
heat rapidly • 

{kic.) Why on copper platet painted hladt, white, gray, Sfc. does 
wax vMt loonut on the black and other dark cohrt, andtcarcely at 
all on the white,* when they are exposed to the tun ? — The answer 
is founded od the general enect of colors on the absorption and radi- 
ation of heat. 

(U.) Why do piecet of doth of different colon, black, tcAite, and 
intermediate thadet, vd^ laid on mow in the nmtktne, liak into the 
tnow very differently, the black deepest, and the white not at alii — 
The answer is the s.aine as under A*. 

(mm.) Why in ntmmer, it the temperature of the earth several de- 
grees lower than thai of the air, especially in a clettr night ? — It is 
owing chie^ to radiation, as beautifully illustrated by Dr. Welb. 

(nn.) Why, in hot weather, is a house cooler iflupt dark, than t/" 
light and air are freely ad7nitted9 — Because the radiant heat, flow- 
ing, not from the sun only, but from alt external objects, some of 
which are often much heated, is also excluded. 

{oo.) Why is white a good color for the roof of an ice house, and 
hltuk a bad color for any roof? — Because the former reflects, and 
Ihe latter absorbs the heat rapidly. 

EXPEKIIfENTAL ILLCBTKATIONS. 

1. Inequality of conducting power. —Dr. Hareyfrom Ito 11, ex- 
cept 3, 4,and&. 



" Let there be four rods, severally of metal, 
wood, glass, whale bone, each cemented at one 
end tma ball of sealing wax. Let each rod, at 
the end which is not cemented to the wax, be 
succesavely exposed to the flame excited by a 
blow pipe. It will be found, that the metal be- 
comes quickly heated throughout, so as to fall 
off from the wax — but, that the wood, or whale- 
bone, may be destroyed, and the glass bent, by 
the ignition, veiy near to the wax, without melt- 
ing it, so as to lUwrate them." 



* TIm cglwed turbcM racaiTlng tba rtTi, wd (be waxed ride bdng downwird*.. 




■OMzcdoyGoOgle 



I 



BEAT OR CALORIC. 



3. Qbm to IteaUd iy tke Jrietion o^ a tord, at to leparate into 
ftM partt, on belmg ttibjecUd to cold voter. 



" ScHne years ago* Mr. Lukens showed me, that a smaO phial, or 
tube, mi^ be separated into two puis, if subjected to cold water, 
after being beaten by the firiction of a cord made to circulate about 
it by two persons akemately pulling in opposite directioos. I was 
subsaqueDtly enabled to employ this process, in dividing lai^ vks- 
sels, of lour or five inches in diameter, and likewise to render it, in 
every case more easy, and cntain, by means of a piece of' plank 
forked like a boot jack— as represented in the preceding figure^ 
and also having a kerf^ or slit, cut by a saw, parallel to, and nearly 
equi-disnnt bom, the principal auiucea of die plank, and at right 
SDgles to the other iuciaions," 

" By means of the fork, the glass is easilv held steady by the band 
of oos operator. By means of the kerf, the string, while circulatmg 
about the glass, is confined to the part, where the separation is de- 
sited. As soon as the cord smokes, the glass is plunged into water, 
or if too la^e to be easily immersed, the water must be thrown up<Hi 
it- This method is always preferable when the glass vessel is so open, 
that on baing immeraed, the water can reach the inner surface. As 
plun^Dg is ma moat efi^tual method of employing the water, in the 
case of a tube, I usually close the end which is to be sunk in the wa- 
ter, so as to restrict the cooling to the. outside." 
10 



OMzcdoyGoOgle 





74 BEAT OR CALORIC. 

3. Metals, he. — Provide as macy equal 
ylinders of meuls as may be desired ; fix 
vertically in a perforated copper w 
plate, their lower ends resting on a 
similar and parallel plate connected with the 
upper one at a small distance by metallic posts. 
Place upon each metallic cylinder a diin 
slice of phosphorus, and set the apparatus 
upon hot sand ccKitained in an irCHi pan ; the 
pieces of phosphorus will succesnrely take 
fire, in the order ^cteteris paribus) correspoit- 
ding with the conaucting power of the metals. 
*;?p^,!rd^'iStl','" If there be a gl.„ cylinder .monj the olher, 
the phosphorus upon that will not take fire.* 
4. Metals and Wood. — A soUd piece of metal one and a half 
inches in diameter, and eight inches long, closely wrapped in clean writ- 
ing paper, will bear to be immersed in the flame of a spirit lamp, for 
a considerable time, without scorching the paper; but if the paper 
be applied to a piece of wood, and heated m a similar mamier, the 
paper will immeoiately bum. — l. c. k. 

5. Liquidt almott datitute of conducting 

power. 
That liquids are almost devoid of power to 
conduct heat it proved by the it^mmaiioK 
of Ether, over the bulo of an air ther- 
mometer, protected oiUy by a thimlratum 
of water. 

"The inflammauon of ether, upon the 
surface of water, as represented in this fig- 
ure, does not cause any movement in the li- 
quid included in the bore of the thermom- 
eter at L, although the bulb is within a quar- 
ter of an inch of the flame. Yet the ther- 
mometer may be so sensitive, that touching 
the bulb, while under water, with the fin- 
gers, may cause a very perceptible indica- 
tion of increased temperature." 

" By placing the shding index I, directly 
opposite the end of the liquid column in 
the stem of the thermometer, before the 
ether is inflamed, it may be accurately dis- 
covered whether the heat of the flame cau- 
ses any movement in the liquid." 

* Soiii«tiine9 th« pbosphorus will m«U in Uie air, without taking fire, but on 
jkTrii^ the apMraluB, it will blaze ; a diio film of mcMliad pboaphonis appareittlr 
protects the phofpboruB b«low from combuaUoD. 



[-,1,00 1, Google 



HKAT OR CALORIC. 



75 



CIBCUI^TIOI) Un»ISPUISABL.B, TO AN CmCTUU. COMMUNICATION 
or HEAT IN U41UID3. 

6. Different efftcU o/" heat on the vpper or lower itraia of a liquid. 
"- "A glass jar, atiout 30 inches in 

height, is supplied with as much 
water as will rise in it within a few , 
inches of the brim. By means of 
a tube* descending to the bottom, 
a small quantity of blue coloring 
matter is mtroduced below the col- 
orless water, so as to fonn a stratum 
as represented at A, in tlie engrav- 
ing. A stratum, differently colored, 
is formed m the upper part of the 
vessel, as represented at B. A tin 
cap, suppwting a hollow tin cylin- 
der, closed at bottom, and about an 
inch less in diameter than the jar, 
is next placed as it is seen in the 
drawing, so that the cylinder may 
be concentric with the jar, and de- 
scend about 3 or 4 inches into the 
water." 

" The apparatus being thus pre- 
pared, if an iron heater, H, while 
red hoi, be placed witliin the tin 
cylinder, the colored water, about 
it, soon btnls ; but the heat pene- 
trates only a very small distance be- 

. low the tm cylinder, so that the col- 

orless water, and the colored stra- 

* turn, at the bottom of the vessel, 

remain undisturbed, and do not 

mingle. But if the ring, R, be placed, while red hot, upon the iron 



stand which surrounds the jar at S S, the portion of the liquid, color- 
ed blue, b^g opposite to the ring, will rise until it encounters the 
warmer, and of course lighter particles, which have been in contact 
whh the tin cylinder. Here its progress upwards is arrested ; and in 



t. %. A dropi^iig tube. 



DMz™.,'Coog[e 



76 HEAT OS CALOBIC. 

litwisequence of the dirersity of the colorG, a well defined Ime of 
separation is soon visible.*" 

" The phenomeoB of this mterestiiig experiment may be thus ex- 
plained." 

" If the upper portion of a vessel, containine a fluid, be heated ex- 
clusively, the nei^boring particles of the fluid, being rendered light- 
er, by expansion, are more indisposed, than before, to descend from 
their position. But, if the panicles, forming the inferitn- strata of the 
fluid in the same vessel, be rendered warmer thUn those above them, 
their consequent expansion and diminution of specific gravity, causes 
them to give place to panicleB above them, which, not being as 
warm, are heavier. Hence, heat must be applied principally to the 
lower part of a vessel, in order to occasion a uniform rise of tempe- 
rature in a contained fluid." 

" This sutement is equaUy true, whether the fluid he aeriform, or a 
liquid, excepting that in the case of ai'riform fluids^ the influence of 
pressure on their elasticity, may someumes co-operate with, and at 
others oppose, the influence of temperature." 

7. Proceai by which caloric u dittribtUed in a liquid before ii boUt, 

"On the first application of 
heat to the bottom of a vessel con- 
taining cold water, the particles 
in contact with the bottom are 
heated and expanded, and con- 
sequently become lighter in pro- 
portion to their bulk, than those 
above them. They rise therefore, 
giving an oppc»tunIty to other 
particles to be heated, and to rise 
in their turn. The particles 
which were first heated, are soon, 
comparatively, colder than those 
by which they were displaced, 
and, descending to their. primi- 
tive situation, are again made to 
rise, by additional heat, and en- 
largement of their bulk. Thus 
tlie temperatures reversing the 
situations, and the situations the 

* " I u«ed to perlbrm Uiia cxpeiiinent wllh ui Inclined tube, as niggMted Id 
Henry's Chemistry. Th« modilicalioD iiofe given, i> so far a contHvince a( my 
own, M relato to the Uae of the heater, tin cup, and inin ring ; and the employment 
of (wo colon irutead □[ one. On accounl a| iha Jjability of the glua to crack, I 
found the old method very prectrious, nbeaa tutte vras used large enough to 'how 
Ihe phenomenii advinlagaouely." 



D„tiidD,Googlc 



HEAT OR CALOUa 77 

temperatures, aa inoessam ciroulatioii !• Suppoittdt so iOag as mj 
<»« portion of tbe liquid is cooler tbao another ; or in other words, 
tOl the water boils ; previously to which, every panicle must have 
C(»nbined with as much caloric, as it can receive, without being con- 
verted into BtMUtt.** 

"Tbe maoDBrin which caloric is distributed throughout liquids by 
circuktioD, as above described, is illustrated advantageously by an ex- 
periment CKHittived by Ruiuford, who first gave to the process, the at- 
tMnion which it deserves." 

" Into a glass nearly full of water, as represented by the fcMvgcnng 
figure, some small pieces of amber are introduced, which are in spe- 
cific granty so nearly equal to water, as to be Kttle influenced by grav- 
itation." 

" The lowermost part of the vessel bong subjected to heat, while 
thus prepared, tbe pieces of amber are seen rising veilically in its 
axis, and after they reach the surface of the liquid, moving toward* 
the sides, where the vessel is colder frtHii the influence of the exter- 
nal air. Havhig reached the sides of tbe vessel, they ank to the 
botbini, whence they are anm made to rise as before. While one 
set of tbe fragments of amber, is at the bottom of the liquid, some 
are at the top, and others at intermediate ntuations ; thus demotutra- 
ting tbe movements, by which an equalisatiim of temperature is ac- 
complished in liquids." 

"When the boiling point is almost attamed, the particles being 
nearly of one temperature, tbe circulation is retarded. Under these 
circumstances, the portioas of tbe liquid which are in ctMitact with 
the heated surfoce of die boiler, are caoyvned into steam, before 
they can be succeeded by others ) but the steam thus produced, can- 
not rise far befixe it is condensed. Hence tbe vibration and smging, 
which is at this time observed," 

8. Provide a glass mbe twelve or fifteen inches long and from 
two to two and a half wide, closed at one end, and that end thin, so 
as to bear beat ; nearly fill the tube with alcohol, and then witb a 
dropping tube, convey to die bottom some alcohol, colored by turmeric 
or coctunea] and rendered a litde heavier by water ; if dexterously 
done, there mil be a weD defined line of separation ; then apply heat 
at the bottom, and the color will be rapidly dif{iised. 

Now repeat the experiment, onh' place the colored alcohol* on the 
surface ; tne coIot on tbe top wIH be scarcely disturbed till the fluid 
be^B to boil. 

* It b hardly neceiMUT to ray. (hat no wiler ihould be added to IL 



DK;,lz=..,C00g[e 




^= 



'g HEAT OR CALORIC. 

9. Moddfor muttrating the cperation of cmeaee mirron. 

"The object of 
the model rejwe- 
Aseoted by ibia dia- 
gram, is to explain 
ihe mode in which 
two iDirrotB opet- 
ate, in collecting 
the rays of nuliut 
beat etoitted froiD 
I one focus, and in 
concentrating them in another." 

" The caloric emitted by a heated body in the focus of (he minw 
A, would pass off in radii or rays lessening liieir intensi^, as the 
space into which they pass enlai^es ; or, in other words, as the 
squares of the distances. But those rays which are arrested by the 
muTor, are reflected from it in directions parallel to its axis.* Be- 
ing thus corrected, of their divergency, they may be received, wilb- 
out any other loss, than such as arises from mecluinical imperfections, 
by the other mirror ; which should be so placed, that the axes of the 
two mirrors may be coincident ; or, in other words, so that a line 
drawn Uirough their centres, bom A to B, may at the same time pass 
through their foci, represented by the little balls supported by the 
wires, WW." 

" The second mirror, B, reflects to its focus, the rays which reach 
it from the first ; for it is the proper^ of a mirror, duly concave, to 
render parallel the divereent rap received from its focus, — and to 
cause the parallel rays which it mtercepts, to become convergent, so 
as to meet in its focus." 

" The strings, in the model, are intended to represent the paths, 
in which the rays move, whether divergent, parallel, or convergent." 

10. Phosphonttj kindled at the dutance of fuKnfy, or even at six- 
ty feet, by an incandeMcent iron ball. — Dr. Hare. 

" The annexed figure represents the mirrors, which I employ in 
the ignitioQ of phosphorus, and lighting a candle, by an incandescent 
iron ball at the distance of about twenty feet." 

" I have produced this result at sixty feet, and it mkbt be always 
efiected at uiat distance, were it not for the difficulty of adjusting the 
foci with sufficient accuracy and expedidon. I once ascertained 
that a mercurial thermometer, when at the distance last mentioned, 
was raised to 110 degrees of Fahrenheit." 



DMz.dDyG00g[c 



HEAT OR CALORIC. 



OMzcdoyGoOgle 



80 



HEAT OR CALOUC. 



" Some coQOD, imbued previously with phosf^iorus, is suiqxvted 
by a wire over a candle wick, [riaced as nearly as possible, in the 
focus of <Hie of the mirrors. A Ismp being similarly situated with 
respect to the other mirrw ; by receiving the focal image of tbe 
flame on any small screen, it wiU be seen in what way the arrange- 
ment must be altered to cause this image to fall upon tbe phos- 
phorus." 

" The screen S, placed between the mirrors, is tfaea lowered so 
as to intercept tbe rays. The uxin ball being rendered white hot, is 
DOW substituted for the lamp, and tbe screen being lifted, ibe phos- 
phorus takes fire, and the candle is lighted." 

" Detcription and amttrvaion of the mitrort. — ^The mirrors rep- 
resented bv the figure, are axteen inches in diameter, and were 
turned in tiie lathe, the cuttbg tool being attached to one end of an inn 
bar two feet long, which at uie other end turned upon a fixed pivoL" 

" Of course the focal distance, being one half tne radius en «»- 
cavity, is one foot." 

" I desi^ied these mirrors, and proposed to have them made out 
of castings ; but pursuant to the adnce of Dr. Thomas P. J<Hies, i 
resorted to sheet brass, which was rendered the more competent by 
strengthening tbe rims with rings of cast brass, about three fourths (d 
an mch thick each way. For me idea of these rings, and the execu- 
ticm ofthe mirrors, I am indebted to Mr. Jacob Perkins." 

'* I believe there are noae superior, as the face is reflected by them 
much magnified, but without the slightest distortion." 

" For the ratkaiale of the operation of the mirrors, I refer to the 
preceding article." 

11. tkveriity t^radiatit^fouiermmetaU,v>ood,chareoal,gIau, 
pottery, tfc. 




OMzcdoyGoOgle 



HEAT OR CALORIC. 81 

" At M, in the preceding figure, a puabolic mirror is represented. 
At B, a square glass bottle, one side of which is covered with unfoi), 
and another so smoked by means of a tamp, as to be covered with 
carbon. Between the botde and mirror, and in the focus of the lat- 
ter, thwe is a bulb of a differential thermometer, protected from re- 
ceiving any rays directly from the bottle, by & small roetallic disk. 
The bottle being filled with boiling water, it will be found that the 
temperature io me focus, as indicated by the theriDometer, is greatest 
when the blackened surface is oppoute to the mirror ; and least, when 
the tinfoil is so utuated ; the ei^t of the naked glass bebg greater 
than the one, and less than the other." 

" When a polished brass andiron is exposed Irom moming till night 
to a tire, so near as that the hand, placed on it, is scorched intolera- 
bly in a few seconds, it does not grow hot."* 

" Fire places should be constructed of a form and materials to fa- 
vor radiation : flues, of materials to favor the conducting process." — 

12. A cork thrust into a candlesdck ; some black wool pushed by 
a knife into a slit in the cork ; some thin slices of phosphorus or sul- 
phuret of phosphorus, laid upon the wool or wrapped b it, the focus 
being previously ascertained by the bght of a candle, will hardly ever 
foil of success, f.an ignited iron ball or a few live coals being placed 
in the other focus. A screen of glass or metal may be held between 
the mirrors dll we are ready for the result. 

13. Fulminating mercury, or silver, or gunpowder, may be sprink- 
led on die wool or on charcoal, but they will by their expk)aon ^ 
the mirror : the effect is otherwise agreeable. 

14. Boiling water being in one focus and a delicate air, or difieren- 
tial thermometer in the odier, there is an evident movement of the fluid, 
imd the glass screen being interposed, arrests and soon reverses the 
effect. 

15. A bright metallic mirror, held before a common fire, remains 
cold, but, if blackened by candle smoke or India ink, it becomes hot. 

16. Provide two bright tin flasks or polished metallic tea pots ; black- 
en one with candle or lamp smoke, then pour boiling hot water from a 
tea kettle into both ; examine the temperature, at intervals of five 
minutes, and it will be found that for more than an hour, the bright 
vessel will remain decidedly the hottest, and sensibly so for several 
hours. J 

17. Fill them with cold water and place them before a bright fire ; 
the blackened vessel will become hot, and the other will remain cold. 



* Except (htt k Utile beat p«Me« hf iloir eommunlcatian iloiiK Ihe irao bir. 

i Amoiue trap wilbout the bottom, nipported by the rlDKoTKTalorlitRDd.iiiiIiu ■ 
nodGre gnta, ind ■ (heet of copper, ziiic, or iron, will proMct the table Troni the 
falling anil. t See the italeinentof sxperiinenU,p^ Tl. 



OMzcdoyGoOglc 



82 HEAT OB CAWRIC. 

With a mask coated with tin fdl, our faces may safely encounter the 
blaze of a glass house furnace. — Ure'» Die. 277. 

18. Hot water coob faster in a glass, than in a pobshed metalbc 
vessel. 

19. *' Radiation of cold. — A. thermometer, placed in the focus of 
a mirror, indicates a decline of temperature, in consequence of a mass 
of ice or snow being placed before it, in the situation occupied by the 
bottle, in tlie preceding figure. This change of temperature has 
been ascribed to the radiation of cold, and has been considered as 
demonstrating the materiaUty of that principle. For, since the trans- 
fer of heat, by radiation, has been adduced as a proof of the exis- 
tence of a material cause of heat ; it is alleged that the transmis^on 
of cold, by the same process, ou^t to be adnutted in endence, of a 
material cause of cold."* 

But, it is necessary to suppose only tliat the heat flows from the 
diermometer, which is relatively the hotter body, to the ice, which b 
constantly absorbing the radiant heat of the room and that of the 
diermometer more than of any other body, because the heat is there 
concentrated by the mirrors, and thence flows in greater quantities 
than is true of any other place.f 

111. CoNfiEl.ATlON AND LIQUEFACTION. 

(a.\ Dr. Black jint proved that fiuidity depend* on a peculiar com' 
binatton or operation of heat or caioric. 

(b.) The sensible heat of both melting ice and freezing water is 
at all times and places 32° of FaAr.J— h. 

The water, when first formed by melting, is at 32°, and the heat 
absorbed during liquefaction has merely melted the ice, and has not 
raised its temperature. If ice is colder than 32", it cannot melt till 
it attains iliat temperature, and the sensible heat will neither rise nor 
fall during the process of melting. 

(c.) The quantity aisorbed is 140° — A pound of snow at 32° and 
a pound of water at £72", if quickly mingled, will give the tempera- 
ture of 32", therefore 140° have been absorbed to melt the ice, and 
are not discoverable by the senses or by the thermometer.^ 



• Dr. Hare. 

1 1ce Bt sa", 

ture. e. g. sail nnd saow producing > rold of 0, woutil be, reiilively, a warm miDt Id 
a mcctminor40°bc1o»U. 

) Th« freezJD;; and melting p<dn(« of all bodies are the ume Sot sach particular 
body, bnl no iwo coincultr, unlew by chance ; c. ^. solid mercury metis at — 3S 
aolid water or ice at-(-82°. Moat bodies, ai the melaia, melt without becoming pre- 
Tiously soft, but otbcra which arc bad contluctors, Iwcome loft lirst, aa butter u>d 

§ Several other experiments of Dr. Black, go to prove the game mult, namely 
that while ice is melting, a quantity of bent entera into ft, wilbout raliiDglta tBi*p»- 
rature, nhich would laUe [bat ofwiler 140". 



OMzcdoyGoOgle 



HEAT OR CALORIC. 

(d.) Fre«:atig water gives otti 140° of heal. — This warms llto in- 
cumbent air, which rises and affects a delicate UiennomcLer, suspend- 
ed above the freezing fluid. FreeziDg is therefore a warcuing process, 
and sensibly miiigaies the severity of wbiter ; the 140" being near- 
ly the whole difference between tlie extreme climates of the globe, 
and being given out from the extensive surface of the freezing waters 
and plants, which are imbued wlih moisture, it greatly mitigHlcs the 
atmospheric cold. 

(e.) Mehing tee, specially if suspended, u attended by a desceiid- 
ing current of cold atr, which is perceptible even to the hand, and 
stDj more, by racaos of a delicate thermometer. Liquefaction i^ 
therefore a cooling process, as is perceived also from die chilly air 
produced by melting anow in a bright day. 

(/.) fVater cooled below 32°, if agitated, congeals into a spongi/ 
mass of ice; the evolved latent heat raises the temperature to 32^, and 
a part of the ice slowly melts again. — Water may be cooled 20" or 
more below the freezing point, or 32° of Fahr. Tliis is best done in 
a tall vessel, with a narrow mouth, and with a film of oil over the 
surface of the water ; it happens often accidentally in domestic ves- 
sels, in cold weather. Water tlius cooled, immediately commences 
freezing, if a particle of ice or even a crystal that is floating in the air, 
happens to enter the fluid. 

(g.) All tolids absorb heat when becoming fiuid and retain itwhUc 
in that state. — The quantity of heat is different in different cases, 
and is to be learned only by experiment. 

Sulphur absorbs 143". 68 of Fahr. spermaceti 145°, lead 162°, 
beeswax 175°, zinc 493°, tin SCO", bismuth 050°. — Black, Henry. 

f A.) The particular quantity of heat which renders a substance 
Jtutd, iscalled its latent heat, or caloric of fuidity. — The word latent 
was used by Dr. Black, merely to denote the condition in which the 
heat exists ; laief, it lies concealed. 

It is not a different kind of power, but merely heat in an insensible 
condition and manifesting its character by a peculiar effect, that of 
producing fluidity. 

(»'.) Freezing mixtures, depend upon these principles. — One ingre- 
dient in them, is always a solid, and in producing the effect of gene- 
rating cold, this solid always melts or liquefies, and thus absorbs heat. 
When both substances are sohd, as snow and muriate of lime, or 
snow and caustic potash, or snow and common salt, the effect is of 
course greater. 

(j.J Heat is evolved during the conoertion of fluids into solids. — 
This IS well illustrated by die slacking of lime and tlie mixing of wa- 
ter with bumed plaister of Paris, in both of which cases, the water 
becomes solid and heat is evolved. 



OMzcdoyGoOgle 



84 HEAT OR CALORIC. 

A saturated sohitioD of sulphate of potash precipitated by alcohol 
evolres considerable heat, when the salt congeals.— Henry. 

Jk.) Were there no abiorptvm of heat to become latent during the 
'ing of ice, eountriet covered mth mote might be imtantaneovsly 
devoMtated. — The toirents are even now, very destructive ; then, tfaej 
would he ruinous. Snow and ice would inttmttly melt, as soon as 
the temperature rose above 32°, but as the absorption of 140° of 
heat is indispensable, the process b necessarily a slow me. 

((.) The heat abiorbea in liquifaction, is given out again »t 
Jreeztng. — Thus one cause tends jo correct the effect of the other, 
and both causes conspire to regulate the temperature ; for thamng is 
a cooling, and freezing is a warming process. 

IV. Vaporization and Gasificatioh or the formation of 

AERIFORM BODIES. 

Introductory Remat^. 

Weight andpretture of the almotphere. — ^This subject belongs to 
mechanical philosophy,* hut it is unpossible to make any progress in 
investigaung the nature of aerial agents, without taking into view the 
pressure of the atmosphere. Its existence is fully demonstrated, by 
the rise of water in a pump, and by the stationary condidon of the 
colunm of mercury in a barometer tube, as well as by many com- 
mon occurrences.f The pressure, in any given place, varies at dif- 
ferent times, but the medium is about fifteen pounds on the square 
inch, corresponding to a column of thir^ inches in tlie barometer ; to 
about thirty three feet of water, and to columns of other fluids varying 
in height according to their specific gravity. 

Taking the doctrine of atmospheric pressure for granted, we pro- 
ceed to aeriform bodies. 

(a) An axriform bodyitone having the mechanical properties of air ;^ 
a vapor it a traniient aertform body, condennble by cold, orpresmre, or 
both united ; a gat it mppoted to be permanently aeriform under eve- 
ry degree ofpretture and cold. — Some latitude is allowed in the use 
of these terms, and a few bodies continue to be called gases, which 
have been condensed ; e. g, ammonia, euchlorine, sulphurous acid, 



n Nalural Phllowphy.— 
. I >bly iliuatrated l>y Dr. Hire, 
In his Compendium, p. SB. 

t II i> now nnul that fliei and olher insccli walk on the celling of a room wllh 
their litclis downiTard«, In consequence of thp peculiar irelibed structure of Uicir 
Teet, which euBblen Ijieni to pre« the wall M ctoiely, thkt lilCle or no air Inlerrcoe*, 
and thus the prcuure of ihe atmosphere lieppi them in their placet. — i.. u. i. 

i Atmospheric alrhu, by presaure, been reduced (o j^^ pari oTita Toluoie, w(tll> 
out loilug i(a elaBlic form. 



a D, Google 



HEAT OK CAlfiKlC. 85 

sulphuretted hydn^en, carbonic acid, nitrous oxide, cyaoogen, muii- 
atjc acid, End chlorine.* 

Strictly, the distincticui between vapors and gases, although conven- 
ient in description, is unimportant. A vapor is derived from a body 
whose vaponfic point is within our reach ; but that of a true gas, is 
lower than our means will enable us to go. 

Jb.) Caloric convert* bothf tolidt andjbtuli tntogiaet, and vapon. 
'amphor, benzoic acid, and carbonate of ammonia, are easily 
converted into vapor, by being thrown upon a warm iron ; a bell 
glass may be placed over them to catch the vapor. Some solids are 
volatilized wiuiout previous fusion — sal ammoniac and arsenic are of 
this number. 

(C.) With Eq,UAL pressube hvd pumtt, evebt LiQ,oin has a 
TIXED BOILING OB viFORiTic POINT ; e. g. Water, die barometer be- 
ii^ at 30 inch, boils at 213° ; ether, at 96° or 98° ;| alcohol, 173° 
to 176°.^ 

Water in a glass vessel boils at 214° or 216° — m a metallic ves- 
sel, at 213°. The boiling point in most liquids, is lowered several 
degrees by putting in chips lof wood, coils of wire, metallic filings, 
pounded glass, &c. — The bubbles of steam are thus broken, and the 
beat escapes more rapidly. Dr. Bostock thus reduced the boiling 
point of ^er, 50°, and that of alcohol, 30°. || 

{d.) The ttuan or vapor, it of the tame temperature vnth ike boil- 
ing Itquid. 

(E.) Phenomena of ebuixition— explained by the instance of 
water. As the water is warming from the conunon temperature, it 
is first thrown into currents by the change of specific gravi^, and 
when it arrives at 212°, IT elastic vapor then forms at the bottom of the 
fluid, and from its levin ascends, is condensed and disappears ; it is 
followed by other bubbles, and when the water is thus all heated to die 
boiling point, the vapor passes Ltirough uncondensed, and is dissipated 
U the top. The water remains at 212° till the last drop is exhaled. 

The old theories of palpable fire, or matter of caloric, of air bub- 
bles passing through the water, and thus causmg its ablation, 8£c. 
are untenable, and unworthy of discus»on. Water, in the aeriform 

' See Ur. Fanda; '■ «ip«rim«nti ia Fhiloi. TmiMu:. part U. Ibr 1S22, and Am. 
Jour. Vol. 7 pa- 352. 

t Dr. Black laiil the handttion of Ifae philoMpIiy of vapor* and gaata, or {□ other 
word*, of aCrifbrm bodies, by hli discorerlea reapecling; lateot heat, and by provlp^ 
the dlMlDct eiiatence of an aflrtfona body, diflfarent froia common air, naiualy,eartio- 
nic acid ng, called by h\m,fixed air. Tbe period oC this dljcorery waa ITST. 

1 I>r. Ura sayt 100°. 

§ Fw eiceptloDii, See Heury, IO)h Land. Ed. Vol. I, pa. 114 ; Ann. Philoi. nen 
seHea, IX. 29B. Ann. de Chira. at de Phyn. torn, Vtl. pa. SOT ; and Jour. Science, 
Vol V. pa. 861. II Ann Phil. N. 8. Vo). IX. 

V And alM, when (he vapor baa acquired elajttic power lafficient to Uft both the 
fltrao«pheTe and the aupcrincumbcDl Huid. 



OMzcdoyGoOgle 



be boiled ii 



M HEAT OS CALOKIC. 

state, or steuo, is tbe true cause of the mechmical aiovements in the 
boiliog fluid, and tbe cloud which we see in tbe air near the surface 
is the vapor condensed into minute dropa resembling a fog or mist. 
The singing arises irom the escape of innumerable air bubbles, and 
the cra<£ting noise, that precedes biHliog, and ceases whai it iM^ns, 
is owing to &e formation of elastic rapor, and its immediate conden- 
a by the colder fluid above. 

") Perfectly formed vapor it invitible. — If water or other fluid 
led m a glass flask, the space above the water, appears as if 
tbe vessel were empty, and the cloud at the mouth consisting of coo- 
densed steam, in the form of mist, would ' not be seen, if the air 
were of the temperature, 212°. 

Ether, in thin glass vessels, is easily vapoiixed by applying boifing 
water, and condensed again by cold water. 

(G.) The latenf heat of tteam u about 950° or from thai to 1000°. 
—Dr. Ure adonts the latter number, which is probably correct 
This is proved, by distilling one gallon of water, and condensuig tbe 
' wpot in a worm immersed in ten callous of the same fluid, each of 
which will receive nearly 100^ of heat, and this multipUed by 10, 
pves the above result very nearly.* (h- one gallon of water in steam, 
will heat six gallons from SO" to 212°; 212 — 50x6=972= latent 
heat of steam very nearly. 

Hence, steam is an excell«it vehicle of heat, and is very useful in 
coc^ery, in beaUng manufactories, drying gunpowder, and chemical 
precipitates, in heating baths, dye vats, and apartments for invalids ; 
u making [^armaceutical extracts, and in many other cases. Lai^ 
vessels of wood are employed with great economy because they can 
be heated by steam. 

(H.) Principle of Distillation. 

Calorie, eombinmg mih Ike more volatile pari of a fluid, raise$ it 
in vapor; it is again condensed by the cold water of the refrigeratory, 
which thus becomes rapidly hot, and must be often changed ; this is 
usually dcme by a stream of cold water conveyed into the condenser ; 
on one side, hot water runs out, and on another, cold water runs in.f 

A retort and receiver is the simplest distilling apparatus ; the fluid 
in the retort is made to boil, and the vapor is condensed In the re- 
ceiver, which is kept cold for that purpose. SvhUmaiion is the lame 
thing in principle, at diatUlation, but the vapor is condensed in the 
soUaform; this is seen, in the case of camphor, sulphur, benzoic 
acid, corrosive sublimate, calomel, arsenic, &£c. 

* Due illowiuiee being made for the UDiibU heU, ukd for wutc. Henry, lOlh 
I.oiid. Ed. y<A- I. p. 127. 

t Col. Wen. MoMley of New H&vea, ingenlouil; Bvuli himaelfof the cold water 
at the bottom u)d oT tne hot water at the top of tbe condeiuing tub, lo supply bath* 
coflvenleotly utd ecrawnictlly. 



OMzcdoyGoOgle 



HEAT OR CALOMO. g7 

IKsimadon in <racuo, although it is attended by do eeononff of 
heat, is a good mode of conducting the process, where the prothwt 
would be injured by a high temperature. 

Vinegar as commonly distilled, has often an empyreumadc lastOr 
but if distilled in vacuo, it requires only 130° of heat, and the pro- 
duct is pellucid uid fine. — l. v. k. 

In these cases, the vacuum is obtained either by driving out the' 
air by tlie vapor, and then closii^ the aperture of ths receivmg ves- 
sel, or, by applying a syringe or air piunp to the receiver, cold being 
also of course in all cases applied to the receiver.* 

(t.) The specific keaX of the vapors of different fiuidt it di^reai, 
and can be ascertained by experimi;nt only. 

Table of latent heal of vaport.^ 



Urs'a Die. 17. Cblm. &c. ziiv. Mih 
VaporofWater, atSlZ" 1000. 955.8 

Alcohol, sp. gr. 0.825, 457. (jp. gr. .793,) 373,86 

Sul. ether, boiling point 104', 312.9(" « .715,)163.44 
Spt. turpentine, " aboul3IO», 183.8(" " .872,) 138.24 
Petroleum, 183.8 

Nitricacid, (sp.gr. 1.494— boiled atl66=,) 650. 

Liquid anunonia, (sp. gr. 0.978,) 865.09 

Vinegar, (sp. gr. 1.007,) 905. 

The force of vapor at the b<Nling point is the same in all fluids ; 
it is equal to 30 inches of mercury, and in all fiuids, is the same for 



' In coDseqDence of a l>i laid b^ the Eoglliii pirliiDiPnl on the Scolch ((illi. by 
which Ihey were lo pay thirty shilling a year OD every gilloo of the capacinr of 
(heir stills. It became Ibeir Inteniiil to make them work m fant as posBLble, and they 
made such ioiprovemenls io the conalructiiHi of theii stllis, that, although the (ai 
was augmented by degrees fiom thirty shillings a jev on a galloD, to filty lour 
pounds, they slil! conliaued (o carry on the buBlnen with «dvant^e. The imprOTe- 
ments consisted chieSy in making the nil I very broadandvery flat, sotliataoly aMnail 
depth of wash could be in it at once, leaving a Tcry large orifice £>r the eaaqn of tfae- 
TBpor, having an interQal nwving apparatus for agilatiDi the wath, to preveat ill 
buniing, and soother in the upper part of the ilill lo break the frothy eflfervescencfl, 
when it would be In danger of boiling over. T)m fire was applied to ■ Tory larn 
surface \ the ebullition was very rapid and general ; no premure was oppoaeil to the 
escape of (lie vapor, and (hui they arrived at such •elonlshlng rapidity in the distilla- 
tion, as to run oir their stiUa of forty or finy gallooa opacity, three times in an boufr 
or seventy two limes In twenty four hour*, (see report on the Scotch Distillery, Phil. 
Mag. Vol. VI. pa. 76,) and by inipn)ven)e]il.t still subsequent, they brought the pro- 
cess to fuchperreetion, Ihal a still of the capacity of forty gallonn in the body, and 
three in the head, charged with siiteen gallon; of wash, coiild be worked Gmr hun- 
dred and eighty limes in twenty four hours, viz. seven thousand ali hundred and 
eighty gallons of wash could he distilled, and a^ the wash would afiord eighteen per 
cent of spirit, it follows, that one thousand, three hundred and eighty two gallons 
could be distilled from a sill) of this capacity in twenty (bur hours, the still could be 
worked olT therefore, twenty times in an hour, or onco in three minutes, and gave 
■houl litiy eight gallons an hour, or near a gallon in a minute. 

< Quoted from Henry, 10th London edit. Vol. I. p. 1!G. 



J cy Google 



68 HEAT OB CALOBIC. 

an equal Dumber of degrees dtove and below ebullitHmt but fixed 
<nl3, sulphuric acid and mercury, aSbrd no readily appredable vafot 
under the boiling point. 

(J.) Sif being converted into iteam, a cubic inch* of water he- 
comet nearly a cubic foot or 1738 cubic inches. Dr. Black and Mr. 
Watt estimated the enlargement at nearly 1800 times. According to 
Gay Lussac it is 1698 times. Alcohol, in rapor, under the comimon 
pressure, occupies 669 times the volume that it did when liquid, and 
edier 443 limes. The specific gravity of steam is 623, ak being 
1000, but the vapor of alcohol is half as heavy again as air, and that 
of ether more than twice and a half as heair, and generally widi a 
few ezceptioDS, the lower the boiling point of a fluid, the ro(H« dense 
is the ^fVoi formed from it. 

(K.) The fhessube or the athospbebe, and pbessiibi: in 

OBNCRjU., exerts an IMPOKTANT INFLUENCE ON TAPOBIZATION. 

As already observed, no correct conclusions respecting aeriform 
bodies can be formed, without taking this subject into view. 

(t.) Theprettwe of the atmotphere it maaured by the column of 
mercury which it it capable of tuttaining. — A glass tube not less than 
32 inches long nor over half an inch in diameter, closed at one end, 
being filled with mercury, and having its mouth first closed by the 
finger, and then mverted and opened under the surface of mercury, 
exhibits the amount of atmospheric pressure, vibradng on both 
sides of 29 or 30 inches, which is about the medium of difierent cli- 
mates, seasons and countries.f 

(m.) At the medium pretmre, pure water hoih at 212° ; if the 
pretmre be diminiihed, water and all fluids boil at a lower tempera- 
ture. — ^This is shewn by the air pump, and by the Torricellian 
vacuum.! Natural variations of atmospheric pressure vary tbe bcnl- 
ing point about 6°. 

(n.) According to Dr. Black, fluids boii in vacuo taitk 124° leu 
of heat than under tkepraiure of the atmotphere; others say with 
145° less, if estimated m the Torricellian vacuum.^ 

As we ascend, it requires less heat to make water boil ; on the 
top of Mount Blanc, it boils at IS?",]! and on the range of Pasco, 
Peru, at 180° .IT In the Rev. Mr. Wollaston's dierraometer, each 



r. Han's eiperimeDts, In hii CampeDdium. 

t For a ubla, ses Henry, Vol. I, p. 116, Loo. Ed. 10. 

$ The ipice above the mercary b a barameter lube : it waa called after Id diacor- 
erer ETaogelisu Torrieelli. 

II The monka at one of the highest Diooaateiiea on Ihe Alps, complala that they 
caonol make good ^MiiUie, (milk porridge,) becauae the water belli aaaomi -.-PaH** 
Pharmaeolegia. A digeater nould remove tbe difficult;. 

T Am. Jonr. Tol. Xtll. p. M. 



OMzcdoyGoOgle 



MEAT OR CALORIC. 89 

dep«e neai the boiling point is divided into 1000 parts. Each de- 
gree of Fahr. is equivalent to 0.689 of an inch of the barometer, in- 
dicating an elevatioD of 530 feet. The 1000th part of a degree in 
WoUaston's thermometer is therefore equivalent to about six inches, 
and the height of a common table produces a manifest difference 
in the boiling point of water.* 

This delicate instrument therefore answers the purpose of a bar- 
ometer, it being necessary only to make water boit in order to deter- 
mhie the elevation of the place. 

The boiling point of water is raised by having salt dissolved in it, 
and the steam has the temperature of the boiling fluid, and so in olhei' 
cases. f 

(o.) Slight variations ofpramre may be exhihited in glass vessels, 
— BotI water in a flask until the air is all expelled by the steam ; 
cork it while boiling ; if tight, it will continue to boil, and the more 
rapidly, if it be cooled, as by touching it with or immersing it in cold 
water, and the boiling will be repressed or stopped hy hot water. 

In a retort corked in the same manner, the same phenomena are 
still more strikingly exhibited ; the water, if shaken after all is cold, 
falls Uke lead, thus illustrating the principle of the water hammer.^ 

Water, boiled in a flask, furnished with a stop cock, has its ebulli- 
tion repressed by closing the key for a very short time; on opening 
it, it boils violently again, and so vice versa. This must be done 
with caution, the operator avoiding exposure both to tlie mouth and 
bottom of the vessel. All these efFecis depend on variations of pressure. 

(P.) Great variations of pressure are safelt exhibited 

IN STRONO METALLIC VESSELS. 

In Papin's digester, or any strong boiler, fitted with a cover, stop- 
cocks and valve, the vapor of boiling water or other fluids may 
be conGned ; Uien the temperature of the fluid will rise as the pres- 
sure increases, and the ebullition will be repressed or stopped. iVa- 
ler may be heated in this manner to 400' of Fahr. or more ; the 
danger of explosion is of course greater in proportion to the heat ;& 
the machine behig suddenly opened, a jet of steam rushes out with 
great violence, and the temperature of the water falls. 

Mr. Southern's table of pressure and temperature is copied from 
Henry. II 

'HcDry.aiul Phil. Trans. * Eoj;. Quar. Jour. Vol. XVIII. 

t Thiali awing lo th« want of ktmoaphcric resbUoce, and shews that rain would 

talMikeihot ifitwere Dot refilled by the air. 

I Aafonnorty bellared, allhouzh now controverted by Mr. Perkine; see Jonas' 
Journal, and American Jour. Vol. XIII, p. ^2. Mr. Perkins Ihlnkii that the pros. 



D„tiidD,Googlc 



90 HEAT OR CALORIC. 

PrcHure In laches TcmperatnK. 

AtmiMpUcrcH. oT mercury. Fihr. 

1 - - - 29.8 . - . - 212.0 

2 - - - - 59.6 - - - - 250.3 
4 - - - 179.2 ... - 293.4 
8 - - - 238.4 - - - - 343.6 

(q.) The latent heat ofiteam may be ihevm bg the digeiter. — Five 
gallons of water are heated to 400" ; the oriGce being opened, one 
gallon flies away in the form of steam ; the resulting tempersture b 
212'; therefore one gallon m steam has carried away heat repre- 
sented by 5 X 188=940= nearly tbe latent heat of steam; for 400° 
— 212-^ 188,and there were five gallons of water. 

(r.) The latent heat ofcoiidemed steam, if suffered to patt ttilo 
cold water, makes it boil quickly, and it toon melts iee. — Great noise 
is produced hy steam striking cold water ; this is owing to its sud- 
den condensation, and the noise grows less as the water becomes 
hotter, till finally tlie steam passes almost silently tlirough water, at or 
near 212", like a gas, and is not condensed.* 

The better way to heat water, is to surround by steam, the vessel 
containing tlie water to be heated. Mr. Parkes heated twenty gal- 
lons in this manner, in six minutes, from 52° to 190°, in eight minutes 
to 200°, in ten minutes to 208", and in eleven to 212°. — l. u. K.f 

Higli steam does not scald, because it is cooled by its sudden ex- 

Eiansion, and it blows along with it a mass of cold air ; indeed it is no 
onger high steam, but common steam partly condensed. It also blows 
a burning brand powerfully, but if held too near, It extinguishes the 
lire in consequence of the condensation of the steam ; it does not 
scald the hand, at a few inches from tlie orifice. The agent in the 
combustion is not so much the steam as die air which it blows along ; 
still, at a verj' high temperature, the steam may be, and probably is 
decomposed, giving oxygen to the carbon, and hydrogen to the flame. 
There is a popular impression that a boiling tea kettle docs not 
bum the hand, but diat, if it ceases boihng, it will produce that efiect ; 
perhaps tliere is a mistake in tlie fact ; and this is llie more proba- 
ble, as tlie trial is of course made in a hurried and imperfect manner. 
(s.J The density of steam confined over water, is directly as its 
elastxaty; that is, the higher the temperature and the greater the 
elasticity, the greater is die quantity of water contained in steam of 
the same volumc.J 



' II ii !<aid hawever that wOer heated Id this nay is stiU two oi 
short of the bolline i>oJnt — l. u. k, 
I Quoline Psrke-t^ Chem. Eway>. 
; Henr}-, Vol. I, p. 122, Lood. iA. 10. 



OMzcdoyGoOgle 



HEAT OB CALORIC. 91 

(T.) " The tame veight of tieam amtaiiu, vihattwr tiuty be its 
tlennty, the tame guantily of caloric; iti latent heat being iTtcreoKd, 
in proportion tu itt sensible heat m diminiihed; and the reverse."*— 
Henry. — ^Water distilled in vacuo at 70°, gave a vapor which, when 
condensed, indicated latent beat amountiag to 1200° or 1300". 
Hence there is no economy of heat in distilling in vacuo, for, as the 
sensible heat is diminished, the latent beat is increased. 

(U.^ But tteam formed at temperaturet above 212°, fuffert a rft- 
minvtton t^ latent heat by the increase of its seTiaible Aeaf.l-— Hence 
there is no economy of fuel in the use of high steam, for more heat 
passes offhy the chimney than where low steam is generated. There 
may be convenience and economy of room and money, in the ar- 
rangements of the machinery, and obviously tlie higher the temper- 
ature at which the steam is formed, the more of it there is m a given 
space, or the more water in the state of steam, and consequently iho 
greater b the moving power. 

(V.) Fluids under vast pressure, may be converted into vapor tnih 
only a small augmentation of volume. — This was done by M. de la 
Tour, J in glass tubes ; alcohol of the sp. gr. .837, and occupying about 
I of the capacity of the tube, became transparent vapor oy expand- 
ing to a little over three times its first volume, and with a pressure of 
119 atmospheres, or 785 lbs. on the square inch; the temperature 
was 404.6° Fahr. 

Ether at 369' of Fahr. became vapor, under 38 or 39 atmos- 
pheres = 576 lbs. to the square inch, and the vapor occupied less room 
than that of alcohol or naptha. 

Water, with a trace of carbonate soda, required a little over four 
volumes to become vapor. In these experiments, the presence or 
absence of atmospheric air made no difference, and on cooling the 
tubes, the fluids reappeared, the vapor being condensed. 

At these high temperatures, water can decompose glass, by sepa- 
rating its alkali, and thus causing the glass to become cloudy. 



* That ia, e conTorso, u the seiuillh heat locretwa, the latent heat diminirhcK, eo 
Ihatequal weights ofitelmtnfuininiroiwrwafn'.UnhBlever temperature, rontam 
the aame qaaotity of he*t; or the total beat of tteam is a constinl quantity. A giv- 
en quantity of vapor of the mme ntwlanre, whatever may t>e Its temperature, aod 
ellMidly imperii toreld water the nme quinlily of beat 

t Manchester Memoirs, Vol. II, new series. Breniter'a Edit, of Prof. Robinson's 

i Annales de Chimie and de Physique. XXf. IZT— ITS. XXII. 400. Annals ol 
PWtoi. V. 290. 



OMzcdoyGoOgle 



HEAT on CALORIC. 



(W.) Of the steam engine. — Dr. Hare. 

TTie principle of Savory's Steam Engine iUutlrated. 



" A matrass, siiuaied aa in ihe above figure, and containing a small 
quantity of water, being subjected to the flame of a lamp, the water 
will soon, by boiling, fill the matrass with steam. When this is ac- 
complished, hubbies of air will cease to escape from the neck of the 
matrass, through the water in the vase." 

"The apparatus being thus prepared, on removing the lamp, the 
water of the vase will quickly rush into the vacuity, in the matrass, 
arising from the condensation of the steam." 
Cff Savory's Engine.* 

"The celebrated engine of Savary, which led to the invention of 
tliat of Ncwcomen, and finally to the almost perfect machine of Bol- 
ton and Wati, consisted essentially of a chamber in whicli steam, 
after being introduced from a boiler, was condensed by a jet of cold 
water, as in the experiment above described." 

"Just before the condensation of the steam, the communication 
with the boiler was cut oS*, and a cock or valve, was opened in a pipe 
descending into a reservoir of cold wat^r. The chamber was con- 
sequently filled with water, which was expelled through an aperture 
opened for the purpose, by allowing the steam to enter again above 
the water. The aperture through which the water escaped, and 
diat through which the steam entered, being closed simultaneously, 
die operation of ccmdensing the steam and filling the chamber with 



OMzcdoyGoOgle 



BEAT OR CALOBIC. 9» 

water was reiterated, as likewise in due auecessioa the otber steps of 
the process, as above stated." 

Cff JVewcOTwn'* Engine. 

" Tlie great objection to Savary's engine, was the waste of steam 
arising from its entrance, over the water, into a cold moist chamber.- 
So great is the power of cold water in condensing steam, that had' 
the steam been introduced, below the water, it could not have been 
expelled until ebullition should have been excited ; but heat, being 
propagated downwards b liquids with extreme difficuttf, the steam 
entering from above was not condensed so rapidly as to paralyze the 
engine. 

" To diminish the very great loss sustained in the en^e of Sa- 
vory, Newcomen, instead of causing the vacuum produced by the 
condensation to act directly upon water, contrived tbat it should act 
upon a piston, moving, air tight, in a lai^ cylinder, like a pump 
chamber. TTie piston was attached to a large lever, to the end of 
which, on the other side of the fulcrum, a pump rod and a weitht 
were fastened. By the vacuum arising from the condensation, ttie 
piston, being exposed to the unbalanced pressure of the atmosphere, 
was forced down to the bottom of the cylinder, drawing up, of coune, 
the rod and weight at the other end of the lever." 

"The cylinder being replenished with steam, the weight on the 
beam drew up the piston in the cylinder, and pushed down the purcp 
rod, and thus by the alternate admission and condensation of stean,. 
the piston and pump rod were made to undergo an alternate motioii, 
by wMch the pump, actuated by the rod, was .kept in operation.-- 
Although less caloric was wasted by Newcomen s engine than br 
Savary's, there was still great waste, as the cylinder was to be heatej 
up to the boiling pomt each tiiiie that steam was admitted, and to 
be cooled much below that point as often as ccudensatitm was e!- 
fected." 

In Watt and Bolton'* Engine,* steam from the boiler lifts the pis- 
ton, and steam let in above, depresses it ; condensation of the steanr 
taking place at the same time, by communicadon with a cold vacuum,, 
connected with an air pump j thus the stroke and condensation are 
alternate, the cylinder is kept constantly hot, and the condenser cold^ 
by water pumped in by the working machinery, from below ; the 
hot water, formed from the condensed steam, is returned totheboiler, 

* This endoe, Ibe mori splendid preBsnC ever ntds by Ecieoce totha arti, la, In 
cominoD wim olher ateini enginoB, far from uiiog the nbote power tbat is nners- 
tod ; for Clement and Deaormea conclude, from their oWD experiments that th« 
beat Btcam engiaea have brought to tiear not more than one twelfth part oC the- 

power of steam, as calculated by (heory.—Tftm, 1. 85, Hh EdiU 



OMzcdoyGoOgle 



94 HEAT OR CALORIC. 

by the operation of the mschineiy ; the atmosphere does cot ope- 
nte, except od the horiz<»ital section of the rod of the piston. In 
this machine, the sLeani is constantly working, nhile in Newcomen's 
it was inert half the time, and not only was the cylinder below the 
piston, chilled at every stroke, by the cold water, but above the pis- 
ton, by the cold air. Mr. Watt's great Improvement con^sted in shut- 
ting out the atmosphere entirely, and in causing the condensation of 
the steam, at a distance from the cylinder, which is in that way maio- 
Ifflned at the boiling point. Thus both the upward and downward 
movement of the piston, is caused by the elasac efibrt of the steam. 

Wolft, Evatu'a or the high Pretsure Engine. — ^There b no con- 
densation of the steam, which is driven out alternately, above and be- 
low the piston, against the atmosphere. As these engines work ^ply 
by dead lift of expansive steam, great strength is necessary in the 
machinery. The principal advantage is in ecMomy of machinery, 
and room ; not of fuel. On account of the strength and smaller size 
of the boilers, explosions are less frequent, than in the low press- 
ure engines, but they are more destructive. Dr. Hare remarks, 
that " the engmes in our steam boats, generally combine the two prin- 
ciples — using steam that will support a weight, of from seven to fif- 
teen pounds, per square inch, and that a true Bohon and Watt steam 
oi£ine, having an ample supply of water, cannot expk>de while the 
safety valve is of a proper size, and not improperly loaded."* 

Perkin't Gencrator.f— The pressure is far beyond any thing here- 
Icfore used j eight hundred pounds, and even one thousand pounds, 
oQ the square inch, is not an uncommon pressure and fifteen hun- 
ted has been frequently used. The generator is very small ; it is 
heated in a furnace ; there is no boiler, but water is injected by the 
machinery, as it is wanted, about one gallon at a time. At Woolwich 
•f late,t the steam was so heated, as to set fire to wood, tow, 8tc. 
ind to ignite the iron generator, at the orifice made for the emission 
af the steam. Wt. Perkins says, that 4000 atmospheres = 65,000 
lbs. on the sijuare inch, is the maximum pressure of steam.^ 

(x.) Mr. Perkins statet that hit high tteam will not iiniejrom an 
orijice, in Am generator, one fourth of an inch in diameter, the pressure 



* irihsM coD^tioiu were olwerved, all Bteun engines would be much safer than 
(bey alt ; but in the high pressure ennnes, the metal is necesurilr exposed botb 
10 the ffeahening eSect of heat, and to the mechanieal strain arising from Tail pro- 
rare ; while in the low pressure engines, these causes are comparatively feeme id 
their operation. The rule for loading the Talve in Hr. Wilt's origiDSl enginci, 
was two and a half pounds for each iquaro inch. 

t See Am. Jour, espeelally Vol. XIII. 

I Jones' Journal, Nov. I62T. 

^ The elastic eneri;y of common steam. Is derived from Ihe latent beat X sp. gr. -f- 
(hr (Birpcralurc or thcmnomctrie tension. — Ure. 



D„tiidD,Googlc 



HEAT OR CALORIC. 95 

being SOOlbs. 00 the square inch, but when cooled down to tie com- 
mon working temperature, it issues with a loartng noise, so as to be 
heard half a mile, and powerfully blows a burning brand which it 
would not do before.* 

(y.) Caiae of the explosion of steam boSert. — According to Mr. 
Perkins and Mr. Hazard, of Philadelphia, it is caused mamly by the 
fact that the boiler, by want of water, becomes heated unduly, and 
heats the steam exces^vely ; the water then dashing up in jets, caus- 
ed by the ebullition, or even by the spontaneous or incendonal lifting 
of the valve, is converted into steam, in such great quantities, that it 
cannot be retained, and therefore bursts the boiler. A boiler full of 
steam, without access to water, it is said, may be heated even to red- 
ness, without explosion, steam being do more expansible than an 
equal volume of air, but if there be water present to form more 
steam, then the pressure becomes uncontrolahle. Red hot iron boil- 
ers, by dec<»nposmg water, doubdess generate hydrogen gas, when 
die water is suddenly let in, and this, being incapable of condensa- 
uon, of course, gready increases the tendency to explosion, which 
the boiler, thus rapidly oxidized, is uu^le to resist. 

STEAK ARTILLERY. 

Mr. Perkins, by applying steam to the propulsion of cannon baBs, 
is able to throw sixty, four-pound balls, in a minute, " with the cor- 
rectness of a rifled musket, and to a proportionate distance." 

A musket may be made to throw, by means of steam, Irom one 
hundred to one thousand balls in a minute, and it is not doubted that 
a constant stream of balls may be discharged during a whole day, 
if required. From five hundred to one thousand btdlets have actu- 
ally been thrown per minute, the steam, all the while blowing off at 
the escape valve. f It is said, however, that the range of shot, pro- 
pelled by steam, is much more limited than if fired in the usual way. 
Prindpie of Cupping. 

A cup partially exliausted of air, by burning paper in it, J and sud- 
denly appUed to the soft parts of the body, allows the flesh to be forced 
into it, by atmospheric pressure, and after scarification, the renewal 
of the process, causes the blood to ooze out. The emission of blood, 
at great heights, as experienced by Humboldt and his companions 
on the Andes, was probably owit^ to the prevailing force of vas- 
cular acdoQ, under a gready diminished pressure, on the surface of 
the body. 



* Mr. Perkins BuppoKs th&theic ii mitt«r aad (hat its accu 
ficQ impriwna (he ateun. 

4 Am. Joar. VoL XIII. pp. 44, 46. 

* Exhaiutiiig ajringo tn> Mid to bt dow iKCMloiially used. 



D„tiidD,Googlc 



HEAT OR CALORIC. 



o )■ Jler^orm bodia can dit^lace grimHiadt orpre- 

/'^\ cot' t't^r entrance into cavUia tmich they occupy. — 

The figure represents a. cylindiicai glass containuig a 

colored fluid, upwi which is a taper floatbg upon a 

vide, flat and thin cork ; a narrow and tall bell glass 

is placed careRiUy over ^ light, and depressed 88 far 

~ ' as it can be, without making the fluid overflow ; the 

light is then seen at & & which is the surface of the 

fluid, within the jar, while a a, shows its position on the 

outside. It is hardly necessary to oieiUion that this is 

( the principle of the diviag bell. 

3. The candle bomb is a spherule of glass cootain- 
ing a little akdiol, ether or water ; it hafi a stem, which 
is stuck into a candle, so that the ball shall be in, or 
just above the wick, which is touched with oil of tur- 
pentine, that it may be lighted promptly ; ^en this is done, the fluid 
is vaporized, and die glass soon explodes ; it should be placed behind 
a screen. 

3. jlglaitjiaak containing water over an Argand or tpirit Itmp, 
or over a few bumbg coals, shews the phenomena of boiling. 

4. Tfte EolipUe. — A copper ball with a recurved tube, shews the 
force of steam, issuing from a capillary orifice ; it will vigorously 
blow a burning brand, or the entire fire, if placed on the hearth. If 
ether, or alcohol, or oil of turpendne be substituted for the water, the 
jet of vapor is then inflammable. The fluid is introduced as it is 
iota the thermometer ball. 

5. Ether it eatily vaporized. 

(a.) In a flaccid bladder, furnished with a stop cock and tube, let 
a litUe ether be heated by contact with hot water ; it will soon in- 
flate the bladder, which being coni[H«ssed, will give a jet of mflam- 
mable vapor ; or cold water applied to the bladder will condense it. 

(&.) A tall thin glass jar, filled with water, and standing in the pneu- 
matic cistern, has a httle ether introduced, by turning up beneath it, a 
vial filled with that fluid : the jar should be ~ 

(secured by recurved tongs, of this form, 
or by a ring on a stand : boiling hot water, 
from a tea ketde, being poured on the lop 

of the jar, the edier boils, and drives the water out ; if the jar be 
quickly lifted out of the water, the etherial vapor may be inflamed 
by a candle, or if allowed to stand, the water will condense the vapor 
and will again fill the jar, except a small space occupied by extract- 
ed air. 



OMzcdoyGoOgle 



HEAT OR CALORIC. 9T 

fc.) Such a flask, as tliat represented at No. 1 1, p. 100, is filled 
Willi water, except an inch or two of the neck, which is occupied by 
odier ; its mouth being covered by tlie thumb, it is inverted and se- 
cured in the pneumatic cistern, and treated as In (b.) and with the 
same result, only the return of the water especially if the neck of 
the flask is plunged deep, so that the water which comes in is very 
cold, may be sudden ; it produces a violent whirl of the injected 
water, which, if it does not break the flask, makes a very pleasing 
experiment ; if, when the etherial vapor Alls the vessel, the thumb 
be used as a stopper, the ball of the flask may then be cooled, and 
the water let in gradually, witliout endangering the vessel, but the 
eflect is much less striking. 

[d.) Ether boiU instantiy at the common temperature, in the Tor' 
rfceZ/tan vacuum. — Form mis vacuum by using a strong tube, thir^- 
three or thirty-four inches long, and a half or tiiree quarters of an inch 
in the bore, and then introduce a litde ether through the mercury, in 
which the tube stands, by depressing a small essence vial full 
of that fluid, beneath the mouth of the mbe, and turning it up ; as 
soon as the ether arrives near the top of the tube, it flashes into 
vapof, with violent ebullition and drives the mercury half or two 
thirds down the tube ; if the tube be then inclined in a position as 
nearly horizontal as possible, without removing its mouth from the 
mercury, a great part of the ether will be recondensed, and tlie va- 
por will be formed anew on raising the tube. 

The above experiment is very strikingly exhibited by filling tlie tube 
with mercury, except an inch at the top, which is filled witli ether, 
and then the orifice being closed with the thumb or the hand, it is 
introduced, in an inverted position, into the mercurial cistern, when 
as soon as the hand is withdrawn, the tube, at that moment occupied 
by the mercury and ether, becomes instantly, in a great measure 
filled with etherial vapor, which, as before, drives the mercury down. 

6. A glass tube, six or eight feet long, and one inch wide, closed at 
one end, and the other fitted with a stop-cock, being screwed to the 
plate of the air pump, may be exhausted to the greatest degree that 
the pump is capable of; if the pump is a good one, the aunosphere, 
when the tube is unscrewed and opened beneadi water, will force 
it up in a jet and nearly fill it : a colored fluid gives the most beauti- 
ful experunent. 

7. If the exhausted tube be opened under mercury, a jet of tliat 
fluid will be thrown in, and the column that is formed may be thirty 
inches lugli. On lifting the tube out of the mercurial cistern, the 
atmosphere will enter, and, because there is still a good vacuum 
above the mercury, the latter fluid will be pushed up nearly or quite, 
to the top of the mbe, and will then fall, and the same effect will 

13 



OMzcdoyGoOgle 



98 IJEAl' OK CALORIC. 

be exhibited seveial limes, but eacli lime in a Uimiiiishing degree, 
uQtil it ceases. 

8. CliLINABV PARADOX. 

EbuUiiion by Cold.*— Dr. Hart, 8 to 14. 

" A matrass, lialf full of water, being 
heated until all tlie contained air is ex- 
pelled by steam ; tlie orifice is closed 
so as to be perfecUy air tight. The 
matrass is then supported upon its neck, 
in an inverted position, by means of a 
circular block of wood. A partial con- 
densation of the steam soon follows, 
from the refrigeration of that portion 
of the glass which is not in contact 
with the water. The pressure of the 
steam upon the liquid of course be- 
comes less, and its boiling point is ne- 
cessarily lowered. Hence it be^na 
again to present all the phenomena of 
ebullition ; and wiU continue boiling, 
sometimes for nearly an hour." 

" By the application of ice, or of a 
sponge soaked in cold water, the ebullition is accelerated ; because 
tlie i^queoiis vapor, which opposes it, is in that case more rapidlj 
condensed : but as the caloric is at tlie same time more rapidly ab- 
stracted from the water, by the increased evolution of vapor, to re- 
place that which is condensed, the boiling will cease the sooner." 



' This Tacl i^ pleasingly ei^hlbited, by providing Iwo cylindrical glau TesBels, of 
tine qunrt nr tno in capieity, (the quart or three-pint tamblen, loM Id tbe ibop*, 
uifwer very well) ; Into oca of Uiem pour cold, and Inio the other hot water ; Hiea 
iinmerac allerDatclyin each, a flaik which contain! water that ww, ju*t before, 
white balling, cut olT, by a good cork, from the atmoaphere ; in the cold water il 
will boil vehemently, and in the hot it will cease boiliDK- 

A retoit if treated in a almilar manner, la a itill better instrument, becauie it pre- 
aenlt in the ball, a large surface for warming or cooling ; and a little cold or hat 
ivalcr poured on cautiously, while the retort u haofclng In a ring, produces a very 
■(rihin^ cflect. If the retort be very thin, and especially if large, ihere Is danger of 
its being crushed by the pressure of the atroospbere. I have repeatedly met Kith 
this Hccidenl, with both retorts and Hasks ; but It is not dangerous, as the fragmenl* 
do not lly aboiil. 



D„tiidD,Googlc 



HEAT OR CALORIC. 



9. ACRIFORM STATE DEPENDENT ON PRESSLltE. 



Proof that some Liquids would alwai/s be aeri- 
form, were it not for tke Pressure of the 
Atmosphere. 

"A glass flask, fig. I, being nearly filled 
with water, and having ihe remaining space 
occupied by sulphuric ether, h inverted in a 
glass jar, covered at bottom by a small quan- 
tity of water, to prevent tlie air from entering 
the neck of ihe flask. The whole being placed 
upon the air pump plate, under a receiver, 
and the sir exhausted, the ether assumes the 
aeriform state, and displaces the water from 
the fiask. Allowing the atmospheric ^r to re- 
enter the receiver, the etliereal vapor is con- 
densed into its previous form, and tlie water 
reoccupies its previous situation in the flask." 




CI 

/^ ^-f^ \ " The return of the ether, to the fluid state, 
/ ^p9^ \ >s more striking, when mercury is employed, as 
IjltL^B '" ^E- ^ > though, in that case, on account of 
the great weight of this metallic liquid, the 
phenomenon cannot be exhibited on so large a 
scale, without endangering the vessels, and 
risking the loss of the mercury."* 



* It )s plewdng lo see to daiue a fluid aa mercury, eBpecially as it U alw brlllianl 
aiidop*lce> becomiim ■ truly traiisparent, invisibte, anJ elastic vapor, nnd then liy n 
slight depresrioD of temperature, returniog again to the fluid state. The bolltei; or 
(he mercury in the thermometer ball sod tube, duiing the coostruction of thst In- 
DtnuneDt, exhibits this fad la perfection. 



D„tiidD,GoogIc 



100 HEAT OR CALORIC. 

10. Atmotpheric wumre opposes and limiit ckeKtcal action, where 
dasttc Jluidt are to be generated or evolved. 

" Water would boil at a lower temperature than 312°, if the at- 
mospheric pressure were lessened ; for when it has ceased to boil in 
|]ie open air, it will begin to boil again in an exhausted receiver ; 
and tliosc who ascend mountains find, that for every five hundred 
and ihiny Teet of elevation, ilie boiling point is lowered one degree 
of Falirenheit's tliermometer." 



The boiling point is lowered by a diminuiioa 
of atmospheric pressure. 

" Water licatcii lo ebuiliti<Hi in a glass ves- 
sel, having ceased to boil in consequence of its 
removal from the (ire, will boH again under a 
receiver, as soon as the air is withdrawn." 



1 1 , Soiling point raised by pressure. 

As the Boiling Point is lowered by diminution of Pressure, so it iV 
raised if the Pressure be increased. 

" Into a small glass matrass, witli a bulb, 
of about an inch and a half in diameter, 
and a neck of about a quarter of an inch 
in bore, introduce nearly half as much 
ether as would fill it. Cfosing the orifice 
with the ihiunb, hold the bulb over the 
flame of a spirit lamp, until tlie effort of 
the generated vapor to escape, becomes 
difBcult to lesist. Removing tlie matrass, 
to a distance from ttie lamp, lift the tJmrnb 
from the orifice : the c[her, previously qui- 
escent, will rise up into a foam, produced 
by tlie rapid extrication of its vapor." 

" Tliis experiment may be performed 
inorfi securely, by employing a vessel of 
hot water, instead of a flame, to warm the matra^^," 



OMzcdoyGoOgle 



HEAT OR CALORIC. 101 

12. Column of Mercury raited by vaporized Ether. 

Jin increase of Pressure results from constraiited 
Ebullition. 
" Having supplied a small flash with a little 
mercury, and a minute portion of sulphuric 
ether : through the neck, let there be a glass 
tube, so introduced, and firmly luted, as that it 
may be concentric with the vertical axis of the 
vessel, and extend downwards until nearly in 
contact with the bottom. If the flask thus pre- 
pared, be held cautiously over a spirit lamp, the 
ether will be more or less converted mto vapor. 
The vapor being unable to escape, will soon 
cause the mercury to rise to the top of the tube. 
On the removal of the lamp, the mercury gradui 
ally falls to its previous »tuation.'' 

It is better, as Dr. Hare has before recom- 
mended, to plunge the flask cautiously into hot 
water (of about 150', or 180°,) as the pressure 
sometimes blows out the bottom of the flask, 
• when, if over fire, a dangerous combustion would 

13. HlCH PRESSURE BOILER. 

That the temperature of Steam m directly as -the pressure, may be 
demonstrated by a small Boiler, suck as m repreaetUed in the fol- 
lowing cut. 

" The glass tube in the axis, passes below the water ui the boiler, 
and enters a small quantity of mercury at the bottom. The junc- 
ture of the tube, where it enters the boiler, is made perfecdy tight. 
On the oppo»te side of the boiler, a tube, not visible in the draw- 
ing, descends into it. This tube coiKists of about two inches of a 
musket barrel, and is closed at bottom. The object of it is (o 
contain some mercury, into which the bulb of a thennometer may be 
inserted, for ascertaining the temperature." . 

" When the fire has been applied during a sufficient time, the 
mercury ^vill rise in the glass tube, so as to be visible, above the 
boder ; and continuing to rise, during the application of the fire, it 
will be found that with every sensible increment in its height, there 
will be a corresponding rise of the mercury b the thermometer. 
In front of the tube, as represented In the figure, there may be ob- 
served a safety valve, with a lever and weight, for regulating the 
pressure." 



OMzcdoyGoOgle 



lOd HEAT OR CALORIC. 

" h has been I'ouDd, that wben the efibrt made by the steatn to 
escape, in opposition to the valve thus loaded, is equal to about fif- 
teen pounds ior ever^ square inch, in the area of the aperture, the 
height of the column of mer- 
cury, C, C, raised by the same 
pressure, is about equal to that 
of the column of this metal, 
usually supported by atmos- 
pheric pressure, in the tube 
of a barometer." 

" Hence the boiler, in this 
predicament, b conceived to 
sustain an unbalanced press- 
ure equivalent to one atmos- 
phere, and for every additioiial 
fifteen pounds per square inch, 
required upon the safety valve 
to restrain the steam, the 
pressure of an atmosphere is 
alleged to be added. wTo give 
to steam at 313°, or the bcH- 
ing point, such an augmenta- 
tion of power, a rise of 38' 
is sufficient, making the tem- 
perature equal to 250°. To 
produce a pressure of four at- 
mospheres, about 293° would 
be necessary. Eight atmos- 
pheres would require nearly 
343"." 

" When, by means of the 
cock, an escape of steam is 
allowed, a corresponding dc- 
clmc of the temperature and 
pressure ensues. 

" If the steam, as it issues 

from the pipe, be received un- 

• der a portion of water of known 

temperature and weight, the 

consequent accession of heat 

will appear surprizingly great, 

. when contrasted with the ac- 

' cession of weight, derived from 

the same source. — It has lu 

fact been ascertained, that ono 



OMzcdoyGoOgle 




HEAT OR CALOBIC. H,y 

measure of water converted into aqueous va^, will, b^ its conden- 
satjon, raise about nine measures of water in the liquid form, one 
hundred degrees," 

Explosive power of steam. 

" If a small glass bulb, hennetically sealed, 
while containing a small quantity of water, be 
suspended by a wire over a lamp flame, an 
explosion soon foUows, with a violence and 
noise which is surprising, when contrasted 
with the quanti^ of water, by which it is oc- 
casioned. 

" In order to understand this, suf^sose that 
the bulb were, in the first instance, merely fill- 
ed with steam, without any water in ibe 
liquid form. In that case the eSbn of the ' 
steam to enlarge itself, would be nearly in di- 
rect arithmetical proportion to the temnfini- 
^ ture ; but when water b present in the H^uiA 
form, while the expansive power of the siewn, - 
previously in existence, is dius increasea, more steam is generated, 
mth a like increased power of expansion. It follows, thai the in- 
crements of beat being in arithmetical proportion, the explosive power 
of the confined vapor will increase geometrically, being actually 
doubled, as often as the temperature is augmented, somewhat less 
than (any degrees of Fahr." 

Mucellaneous utea ofiteam.* 

1. For tBarmng apartments, especially large manufactories. — 
There is no danger from fire ; the boiler may be even in another 
room, and as the steam is u-ansmitted in tubes, it is thus condensed 
and gives out its heat. 

" Every cubic foot in the boiler is equal to heating two thousand 
feet of space to an averse temperature of 70° or 80°," and each 
square foot of surface of steam pipe will warm two hundred cubic 
feet of space. 

2. for drying mtuUn* and calicoet and other good$. — Either the 
stuffs are hung up in rooms and dried by steam pipes giving a beat of, 
100° or 130°, or they are made to pass around cyUnders filled with 
steam. Delicate colors, such as scarlet and crimson, formerly faded 
by stove diyii^, are thus preserved &om injury, although heated te 
165", and die people are healthy, which was said not to have been 
the fact fl^en the rooms were wanned by stoves. 



* Concitely nienllancdbcron:. 



OMzcdoyGoOgle 



104 HEAT OB CALORIC 

3. 6vnp(ni>der u tafely dried, in 8 umilar manner. 

4. Bv lurrounding the veutU with steam, pharmaceutieal txtreuis 
are made, without injury to delicate principles. Chemical precip- 
itates are sometimes dried in the same mode. 

5. Steam ia employed in bleaching. — Instead of boiling the stufls 
with solution of potash, they are steeped in that alkali, and then hung 
up while wet, in a chamber which is afterwards filled with steam, 
which enables the alkali to dissolve and remove the coloring matter 
more effectually and more rapidly than in the old way.* 

6. It it applied to cookery. — It is neat and egectual, and the same 
water may in fact be used twice ; once in the boiler as water, and 
once, as steam, in another vessel, which may be made of tinned iron, 
and placed in any convenient ^tuation, with which a communication 
tihould be established by a bright tin tube ; the boiler must be fur- 
nished with a lid and a safety valve. 

7. /( it utedfor heatttig bath* and dye tati. — The steam may be 
made to pass either through tubes, immersed in the water, or, it may 

; thrown direcdy into the water, which it will heat very rapidly. 



There should be a valve in the tube of communication to pravent the 
reflux of the water into the boiler. * 

Very large quantities of water may be thus heated in vessels of 
wood, and in one third part of the usual time. 

8. For creating a vacuum. — This is perhaps more ea^y Aone 
by the action of steam than in any other way. The first efi^ct 
when the steam engine is put into operation, is to expel the air, and 
lai^e vessels may, in this maimer, be ahnost instantly filled with 
steam, which, being quickly condensed, leaves a pretty good vacuum, 
containing little else than a feeble vapor of water. 

An ingenious still has been constructed by Mr. Barry, for making 
vegetable extracts in vacuo ; both still and receiver are freed from 
air, and as water will then boil at a temperature below 100°, the veg- 
etable extracts are obtained strcmger and without empyreuma cr de- 
eompo»tion.-|- 

fV.) Natural oa spontaneous evaporation, 

(a.) 7^M u the gradual touting of fluids and of some solids at 
aimotpherie temperaturet. — It takes place at the surface, and there- 
fore is not attended with ebullition ; it differs not at all in principle 
• from vaporization ; it is only more gentle and never produces any 
agitation. 

Jh.) JVot only all wateri, but all animatt and vegetahlet and men, 
the entire tuiface of the earth give out moisture by evaporation.—' 
Place ahnost any thmg, even ice itself, under an inverted glass which 



' Murray's Element^ 6lh Edit Vol. r, p. 237. * lUid.p. 143. 



OMzcdoyGoOgle 



HEAT OR CALORIC. lOj 

ia kept coM, and vapor will be condensed in dew or (nm if the cold 
be considerable. Camphor, carbooate of oraraoDia, and other rt^- 
tile solids dve off vapor so rapidly, that when placed in equilibrio in 
balances, Uiey are soc»i found to lose weight. 

(C) The cauM of noluro/ evaporation u caloric. It produces 
Jrom tpoter, at every temperature, an elaitic inviiible vapor, whose 
datticity inertaies toith the ten^erature, and which nutaint a corru- 
ponding co/umn of tnaxury,—t)wivoo and Gay Lussac have fully eg- 
tablisbad this poaitioa. lliie tfaeoir, formerly so prevalent, that evap- 
oratim depends oa the solutioo of wuer in air, is no longer tenable 
u the sole and sufficient cause, but it is still veiv possible,* that va- 
pot may be dissolved in air. The lower tbe boiling point of a fluid, 
the more readily it evaporates. 

(d.) It hai already been stated, (p. 87 ,J that the force of vapor in 
the tame at the boUitig point for every fttid ; — it eqwda thirty inchet 
a/' atercmy, and w the tame, in aUceuet, for an equal number cf 
Street above and below ebuUition.f — This is a cunous fact ; per- 
h^s it would have hardly appeared probable, for instance, that the 
vapor of ether at its UMling point, 98°, of water at 213°, and of 
mercury itself at 656°, should each exert a power capable of sus- 
taining in B tube, a column of that metal thirgr inches in altitude. 

EFFECTS or NITU&U. ETAPOR&TION. 

(e.) Evaporation prodwxt cold became heat mast be absorbed to 
form vapor. — The evaporation of ether under the receiver of the air 
pump freezes water in contact with it, or having only a thm vessel 
between ; so a stream of ether faUiog upon a thin glass tube, fi*eezes 
water contained in it. 

The sensation of cold in coming out of a bath, especially if warm, 
is' owing to tbe absorption of heat to form v^ior. The formadon of 
vapor is a cooling process ; it goes on extensively, and thus regulates 
natural temperature. In the hottest climates, evaporation from ex- 
tensive surfaces of water, mitigates the heat, but where there is little or 
no water, as in the great African desert, the heat becomes intolerable. 

Excessive degrees of heat have been occasionally endured by hu- 
man beings in consequence of evaporation from their own surfaces. 

" Sir Joseph Banks and Sir Charles Blagden, breathed for seme 
time an atmosphere in a. room prepared by Dr. Fordyce, which . 



* NoTisltimpoariblecirevanhighlytnprobable.thatwtlerniy be, to a csrUlD ex- 
tent Mlnble In iIt, u there is obviouily ui affinity between the atma^herlc ciaea 
and water ; but tbe &ct, If admitted, will not account br all the phcDomeu, wlttwu t 
admilting tbeEmnatioDofvipor at lU temperaturea. It in even nU that r>(A)r 
brmed u atnosplierlo tempenturee, haa the nme amount of heat u that fiirmed at 
tfa« boiliOK pclnt ; the latsnt heat Increadng as tbe »eii«iUB beat li diinlniibed. 

f Sec iMlton'a labl«<. 

14 



doy Google 



106 HEAT OR CALORIC. 

was 50° lii^er than diat of boiling water," viz. at 262" Fahr. " The 
temperature of their bodies was not at all raised, though their watch 
chains snd every thing else metallic about their persons were so heat- 
ed, that they could not bear to touch them.* The thermometers 
which huDg in the rooms always sunk several degrees when either of 
the experimentalists touched them, or breathed upon them. Some 
eggs and a beefsteak were placed on a tin frame ; the eggs were 
roasted hard in twenty minutes, and the beefsteak was overdone in 
tfiirty three minutes. Water placed in the same room did not how- 
ever acquire a boiling heat until a small quantity of oil was dropped 
on it, when it soon began to boil briskly. The evaporation from the 
siuface of the water had prevented it from acquiring the heat of 212° ; 
but when that surface became covered with a film of oil, the.evapora- 
could not go on, and ebullition commenced. "f 

" The oven girls in Germany often sustain a heat of from 250 to 
380°, and one of these girls once breathed for five imiiutes, in air 
heated to 325° of Fahr. When the air of such rooms is damp, or the 
skin is rubbed over with varnish, the heat cannot be borne an instant." J 

In the case of Sir Joseph Banks and Sir Charles Blagden, it is 
stated tliat there was no remarkable evaporation from the skin ; the 
insensible perspiration was doubtless greatly increased, and in such 
cases an immense perspiration usually happens, and it is this chiefly 
which either in a sensible or insensible form, renders such trials safe. 
A well varnished man would probably soon die in such circumsttn- 
ces, and probably could not live long at the common temperature.^ 

The cooling of liquors in hot countries, is efiected by evaporation 
from skins containing water, from porous jars, tie. 

Mr. Leslie, witli the aid of sulphuric acid to absorb the vapor, froze 
water by its own evaporation under the exhausted receiver ; some- 
times he employed merely porous solids, as clay, or parched oat meal 
or flour, porous and burnt whin s(ofte,\\ and porous, and ignited pieces 
of muriate of lime. IT 

If the water has been previously boiled, the ice formed is firmer, 
althougli the process is slower. An earthen ware vessel is pre- 



* " The heal of m«l>l« at 120°, is scarcely BupporUble ; water scaidi at 100°, bal 
air may be healed to 240°, without being painruj lo ouroTgaoaof censatioD." — Cimf. 

t Phil. Trans. Vol. LXXVI, p. 271, Ann. 1776.— Quoted by Mr, Parliea.— & 
M;a,2d Lond. Edit Vol. I, p. 70. t Parkcs, quoliaf; Hist. Acad. Sdences, 1T64. 

§ CommiiDicated. — Since reading; " Wclli on Dew," I tiave doubled whether tbe 
powar of tbe animal isretem to endure such a hl|h temperature were owing entiiclr 
to Ibe coollog cKcta of evaporation. PhyBtolofriata maintain Ihat this power of the 
animal matem to endure a hi^ heat, ia connected withtho viial principle. — V. Mr 
ffverardHome, in Phil Tran. 

tThe ScMcb ailloqala] name for {rre«nitone and other trap roclia. 
The Pachaof E^pt prcfcured a fine ^r pump ibr the manulacture of ico byMc. 
L«alie'9 proccn, 



OMzcdoyGoOgle 



HEAT OR CALORIC. 107 

ferred for holding the water. A hemispherical earthea vessel, con- 
taining three pints of water, was placed by Mr. Leslie over a body of 
parched oat meal, <xie foot in diameter, and one inch deep, and tho 
whole of the water was frozen by working the pump. 

By the skiliid management of evaporation and radiation, ice is 
obtained at Benares, in. a climate where, in the summer, the ther- 
mometer is never under 100'", and Is often 110°. 
-. Shallow pits or beds are made four or five feet wide, and about 
four inches deep, separated from one another by narrow borders, and 
so numerous as to cover an extent of about four acres. These pits 
are filled witli dry straw in the middle of their winter, when the ther- 
mometer is about 40° of Fahr. On the straw are placed rows of 
shallow earthea pans containing a few inches of water introduced at 
evening. ■ In the morning they find a little ice, which at sun rise is 
wrapped in flannel and carried to the ice house. Near Calcutta, a 
nmilar process is adopted. In the plains, excavadona are made 
about tturly feet square and two feet deep, and covered about a loot 
deep with dried stalks of Indian com or sugar cane. Unglazed 
earUiem pans about 1} inch deep, are filled with soft water which 
has been boiled, and in the three winter months, some of it is frozen, 
every night, when the weather is clear. At sun rising it is carried, 
wrapped in flannel, to the ice house, which is a deep pit, lined with 
straw and coarse blankets, and covered by a thatched roof — the 
mouth is closed with straw. — L. c. k. 

^yidaUver may he frozen In/ the united inflrtence of evaporation, 
rar^aiAvm and absorption. — If a pear shaped mass of ice contaming 
the metal, be suspended over a large surface of sulphuric acid, and 
a good exhaustion obtabed, it will fireeze the quicksilver, which may 
be kept sohd for several hours. — l. u. s. 

The fi^ezing of wet clothes exposed to the air when the thermom- 
eter is not so low as 32°, is occasioned by evaporuion. 

Phmts are often injiired by the frost when the thermometer is above 
freezing; this is the joint e;^t of evaporation and radiation. 

Wine coolers are usually made of porous earthem jars unglazed ; 
they cool the wine by evaporation from the surface ; several of them 
on a table have an efiect on the air around, which is perceptible to 
the guests. Rooms are cooled hy sprinkling water around them, in 
hot weather. 

Id India, dr^ry is suspended arouad their dining halls, which are 
roofed, but open at the sides, and water being dashed on the cur- 
tains, the evaporation generates cold. 

(f.) Evimoratum contributa to health, by imparting moisture to 
the (Umo^miere.— The driest air contains moisture, which is often 
cfKideiued upon cold objects, especially if they are c;ood conductors. 



DniitzcdoyGoOgte 



lOS HEAT OR CALORIC. 

During hot weather, cold water, io almost uiy vessel, but gdcmest 
in a metallic (we, produces drops of condensed vapor upon the out- 
side and a freezing mixture will generate boar frost from the driest air. 

If the air were deprived entirely of moisture, it would, during res- 
piratioa, parch the membranous lining of the passages, and thus 
produce great inconvenience, and eventually serious nuachief, in 
breathing. 

(g.) Mvaperation tT^uret ketdtk by rainng into the air miiumata, 
produced by animal awi vegetable putrefactton.—Tiua is too evident 
to need illustration ; the eSect is dependent on a certain degree of 
heat, aided W moisture, as is seen in the rice swamps of our south- 
ern stales. Fever and ague* probably arise chiefly from this cause. 
In cold countries extensive swamps do Uttle (» no mischief, and even 
in those that are temperate, they are comparativelv harmleis. Hm 
region about the river Sorel, in Lower, and the Welluid Canal, ig 
Upper Canada, are examples. In particular seasoos, however, soch 
countries become sickly. 

(h.) Evaporation tuppli*$ the moittare neeettary to form rain, 
mow, haU, hoar froit, dew, fog$, mist, fyc. — ^This precipitation take* 
place according to ^e state of the atmosphere ; it is much influenc- 
ed by the mingling of currents of air, differing in temperature,- aod 
in the quantity of vapor they craiuun. 

Precipitation of dew, hoar frost, &c. is much afiected by radiation, 
from the surface of the earth, and this depends greatly on the pre- 
valence or absence of clouds. 

Radiation is most abundant in a clear night, when the temperature 
of the ground is often several degrees lower than that of the air. 
The frost is often caused, principaQy, by radiation from the grotmd ; 
hence, it frequently freezes on the ground when the air is not as low 
as 32°. This subject has been fiiUy illustrated by Dr. Wells, and be 
has explained, why condensadon of atmospherical vapor takes pkce 
when there is not cold enough in the air to produce it ; it is because 
Ae surfaces on which the vapor is precipitated, are cold^ than the 
air ; those surfaces that radiate the best, will therefore be dte oddest ; 
iience, glass will be colder than metals. 

This radiation from the earth's sur&ce is of the utmost importance 
to vegetation, especially in hot cGmates ; plants radiate heat very 
powerfully, and hence, they are often covered with dew, ^rfien the 
naked ground is scarcely moist. This effect is much favored by 
the clear, cloudless skies, of hot cUmates, while in colder regions, 
there is more cloudy weather. The earth is there cold and damp and 



n appUed to atl ni«h e(fect(, ind to tbetr ca 



OMzcdoyGoOgle 



HEA.T OB CALOHIC. |09 

needs much less moisture— ^Dd there rsdistkn is much ]ess ener> 
getic.* 

It has been already mentioiied that a principal cause <^ tbe pei^ 
nun«ncy of snow on high mountains, is the diminubon of capaci^ 
for heat in the air, in consequence of its rarefaction ; it rises oftra, 
highly charged with aqueous vapor, which the cold precipitates 
abundant^. 

U.) CircutMtmuxt ahiekinjiuetux evaporation. 

Siufgce. — Aa natural evaporation proceeds fnm the surface ooJy, 
the more extenave die sDrface, other tilings being equal, ^ more 
rapid is the evapontkn. 

Water in a botde, widi a narrow open mouth, will wasta away very 
donrly, but die same quantity of water, in a wide and flialknr basin, 
wili evaporate much more rapidly. In a narrow-moutbed vessd, tiao 
the pressure of the Tt^Mr which is formed, will react to retard the enp- 
oration. Agitation jmaaoies evaporatioti by enlarging the sur&ce, 
and by exposing warmer parodes succeaaivety. 

Ttmperature.'-^'nie effect of increased tempemture on evapora- 
tkm, is vety familiar ; hot Quids evaporate mam rapidly than odd 
ones, in proponioii as their temperature is higher. 

Vaoor in the air. — ^As a pvea te m perature can raise cmly a given 
quantity of vapor into the air, it follows that evaporation will be more 
or less rapid, according as the quastfty of vapor already m the air, 
is more or less coosiderable. hi a very diy air, die evaporation is 
atways more rapid than in a moist air, and when the vaptv already 
in the aonosjdiere, ia die maximum, that the given temperature can 
sustain, tbeie will be no evapotatiao. 

/Venim.— Ilie principles that hare been established under the 
head of vapor, are applicable here. Evaporation is m(»« or len. 
rapid, as the pressure is greater or less. AtmosiAeric pressure re- 
tards evaporation ; hence, h is remarkablr accelerated in tfae vacii' 
nm o£ Ibe air pump ; but the same quanti^ of vapor is raised in tbft • 
end, whetber die atmosphere be present or not ; the only difierence 
is in the rapidity of the process. " Mr. Dahon fcond that tfae teDoaa 
or elasticity of vapor, ii always the same, however mudi the press- 
ure may vary, m knig as die teu^terature remains constant, and liquid 
enough is fwesent for preservii^ the state of sattvation, pnmer to the 
temperature. If, for example, in a vessel contsiniitg a Uquid, tbo 
■pace ocouued W its Tapor, should suddenly dilate, the vapcr it con- 
tams will duate abo, ana consequendy suffer a diminution of elastie 
force ; but its tension will be quickly restored, because the hquid 
yields an additional quantity of vapcM', proportional to the increase 
of space. Again, if the space be dimimJied, the temperature re- 



OMzcdoyGoOgle 



1 10 HEAT OR CALORIC. 

maining constant, the tension of the c(»ifined vapor, will still continu« 
unchanged ; because a quaatity of it will be condensed, proponkmaj 
to the dtminudon of space, so that in fact, the remaining space ctxi- 
tains the very same quantity of vapor as it did onginalbr. The same 
law holds good, whether the vapor is pure or mixed with any other 
gas."* 

(j.) Mode of atifaaling the force of vapor. — This has been al- 
ready explained under the head of vaporizatioD. Water is introdu- 
ced into the Torricellian vacuum, and the depression of the mercury 
measures the force of the vapor. Vapor beii^ produced at every 
temperature, even bebw freezing, a table was cwistructed by Mr. 
Dahon to express the force through a wide range of temperature. — 
This table, and the results ance obtained by Dr. Ure,f may be in- 
serted at the end of the volume. At the same distance from the 
boiling point, the force of vapor is the same in all fluids. 

(i.J Effect of vapor upon gate*. — It enlarges their volume, and 
that direcUy, b proportion to the temperature.| 

Gases are freed from their hygrometric moisture either by intense 
cold, or what is more usual, by exposmg them to substances, which 
powerfully attract moisture ; muriate of lime, which has been ignit- 
ed, b the substance which is almost always used, and it is very ef- 
fectual. 

{I.) Hygrometert.— These depend, generally, upon a change of 
dimensions, in consequence of absorbing or giving out moisture. — 
A human hair becomes elongated by imbibing moisture, and returns 
to its former dimennons, wbea the moisture is withdrawn ; this change 
is measured by an instrument, usually furnished with an index, and 
a graduated arc. Wood, cord, membrane, whalebone, Stc. are simi- 
larly afiected. 

Cords are shortened in wet weather ; this appears to be owing to 
the enlai^ement of their diameter, at the expense of their length. 
It is often observed in a common clothes line ; most remarkably 
at sea, in die great tensioo of a ^p's rigging during a rain storm, 
and in the relaxation when dry weather returns. 

The amount of vapor in the air, is estimated with CMisiderable accu- 
racy by covering the bulb of a thermometer with a piece of Imen 
or silk, and expo^g it to the air, when the rapidity and extent of 
the fall of the mercury will indicate the amount of vapor. 

Upon this principle, is constructed a liole instrument,^ called the 
Rosometer. It is a ihermometer,jj with a baU of black glass, the up- 

■ Turner's Chem. p. 66. t PhU. Treni. 1818. 

1 For Mr. Dilton'i tbriuult to corrttct tbli remit. See Tamer*! ChemMrr, find 
Eqe. Ed.pt. 68. 
i Inveated bj Mr. Jones of London, and Ur. C«UstreMO, at L^fli. 
H FUM eillMT with mercury or aleobol. 



PMz.dDyGoog[e 



BEAT OS CALORIC. 1 1 

per part of vhich, is covered ^th muslin ; a litde ether being drop- 
ped upon this part of the bail, dew soon begins to be deposited on 
the other, and the temperature at which this happens, is called the 
dew point.* Mr. Pollock of Boston constructs this mstriunenl with 
two halls, one immediately below the other ; the upper one is cov- 
ered with muslin, and moistened whh ether and the dew is depoated 
on the lower ball. 

BXFEBIKENTAI. ILLITSTBATIONS OF TBE UWS OF EVAPOKATION. 

1. Loss of weighi. Water balaitced in teales, hia a pereejitibU 
weight in a tkort time ; — with alcohol and ether the effect ia stiU 
more remarkable. 

2. Heat applied to the fluid gives a much quicker result. 

3. Camphor, carbonate of ammonia, and other very volatile solids, 
in the same circumstances, lose weight, although more tardily. 

4. Dip a finger successively into water, alcohol, and edier, and 
observe that the sensation of cold, u stronger and quicker, the more 
evaporable the fluid. 

5. Production of cold. When the atmoiphere u apparently still, 
we discover which way the vrind it, Ity wetting the finger in the mouth 
and holding it up to the air,— it wiU feel coldest on the windward 
side, the evaporation being there the most rapid, and consequently, 
heat being there most absorbed, from the finger, to form the vapor. 

6. Wateritfrozenbyiheevt^oraiionofether,fintheair; Uiisis 
conveniently done, by placing the water in a glass tube, sealed at one 
end } it may be one third or one half of an inch in diameter, and the 
water may occupy two or three inches in depth ; a coiled wire may 
be pushed into the tube to lift the ice out, (and perbaps to aid by its 
conducting power, in the extricarion of the latent heat ;) if the water 
be colored, the effect will be the more pleasing ; now let a capillar}- 
stream of ether, from a dropping tube or otherwise fall .upon the tube 
containing the water, which may he either naked or may have a little 
gauze wrapped around it ; in a few minutes the water will be frozen 
solid, and a momentary pressure of the tube in the hand will thaw 
the outside of the ice, so that it may be withdran-n by the wire. 

Cold produced by the Palm Glats. — Dr. Hare, from 7 to 13. 
"Two bulbs are formed, at 
each end of a tube, one having 
a perforated projecting beak. — ■ 
By warming Uie bulbs, and 
plunging the orifice of the beak 



Jr 



D„tiidD,Googlc 



\ 12 HEAT OB CALOUC. 

into ilcohol, a portion of thia fluid enters, as the air ffilhin cootncts 
by reUiming to its previoua temperature. Tbe liquid, thus introdu- 
ced, is to be boiled in the bulb wfaich has no beak, until tbe whole cav- 
ity of the tube, and of both bulbs not occupied by liquid alcohol is 
fiUed with its vapw." 

"While in this ^tuaiion, the e^d of the beak is to be sealed, by 
fusing it in a flame excited by a blow pipe." 

"As soon as the instniment becomes cold, the vapor which had 
filled the space within it, vacant of alcohol to the liquid fonn, is coa- 
densed, and a vacuum is produced ; excepttng a ihght portion of va- 
pof, which is always emitted by liquids when relieved from atmos- 
pheric pressure." 

" The instrument, thus formed, has been called a palm ^lass ; be- 
cause the phenomena, which it displays, are seen by holding one of 
the bulbs, m the palm of one of the hands." 

"When thus situated, the bulb in the hand beug ktwermost, an 
appearance of ebuUiticHi always ensues in the bulb, exposed to 
view, m consequence of the liquid, or alcoholic vhpat, beong pro- 
pelled into it froin tbe other bulb subjected to the warmth of the hand." 

" This phenomenon is analogous to the case of ebuUitioii in vacuo, 
(V tbe culmary paradox ; but the motive for referring to the experi> 
meot here, is to state, (hat as soon as the last of the Uquid is forced 
from the buU), in the hand^ a very striking sensatioa of cold, is expe- 
rienced by the operator." 

"This cold is produced by the increased c^aci^ of the residual 
vapor Sot cabrtc, in consequence of its attenuation." 
Remark. 

A little ether dropped on eidier of die balls, immediatelv produces 
a rush of the fluid into that ball, and the other belt beuig then treated 
in a similar manner, the fluid as rapidly returns. Ilie appearance of 
ebullition in the palm or pulse glass is evidently much increased by 
the fact that the thin 61m of fluid, lining the upper part of the ball, to 
which the hand is applied, is rapidly converted into vapor, drives the 
fluid before it, and then rushes through it ; that there is no ebullition 
of the mass of the fluid, is proved by the fact, that if we reverse the 
position of the ball, [facing it uppermost, and allow the fluid to rest 
in tbe ralm of the hand it remains entirelv quiet. 

8. Cold contequent to a relaxation of pretmre. 

"It is immalenal whether a diminution of den^^, arise from re- 
lieving condensed aJr &om compresfdon, or from subjecting air of the 
ordinuy density to rarefaciic»i. A cloud Nmilar to that which has 
been described as arising in a receiver partially exliausted, may usu- 
ally be observed to the neck of a bottle recently uncorked, in which 
a quantity of gas has been evolved in a state of condensation by a 
fermenting liquor." 



OMzcdoyGoOgle 



HEAT OR CALORIC. 113 

ApparatxufoT showing the influ- 
ence of Relaxed Pruaure, on 
the capaaty of Air for Heat, 
or Jaoigture. 

"A glass vessel with a tubulure 
and a neck, has an air thennom- 
eter, fastened air tight, by means 
of a cork into the former, while 
a gum elastic bag is tied upon the 
latter, as represented in this fig- 
ure. Before closing the bulb, 
tbe inside should be moistened. 
Under these circumstances, if 
the bae, after due compression 
by the hand, be suddenly releas- 
ed, a cloud will appear within 
the bulb, adequate in the solar 
rays, to produce prismatic colors. 
I At the same time the thermome- 
l ter will show that ihe compres- 
I sion is productive of warmth — 
the relaxation of cold." 
" The tendency in the atmosphere to cloudbess, at certwn el- 
evations, may be ascribed to the rarefactioo which air inevitably un- 
dergoes, in circulaung firom the earth's surface to such heights."* 



* In cooDexlon with thia effect on (be truupareacy of (be atmospbere, it mty b« 
IntercsllDE to recoUePt, the important InllueDce of barometric^] preuurn on our 
health UM comfort. If we were lo rerard (t sappnsltion which is not exactly true, 
but which may be made lor the sake of illualntioD,) the muscular power of ;he heart 
and artertei ai a eoDstinl force, propelling tbe blood refrularly la the cireuUllon; 
dien it ii obvious, that the VRryiug preaaure of [be itmaspliere must necessariiy af- 
fect both our feelingB and our safrty. With a diminished preasure, there must be a 
more rapid and hurried circulatioD, and with it ne might eipecl fainlnew and Op- 
preaalon as la eiperienced on high mouutBiDS, The oppreanOD and lanilude expe- 
rieuced in what is called a heavy air, (whicb is really a lighter air, our feeliDga alone 
being heavy,) is prfdiably ovilnz, In part, lo this cause. AI moderate elevaliaas, we 
do not experience oppreasiOD, for there la generally a clearer and a coaler atmoa- 

Ebere, and our moral euewy ia invigorated by tbe scenery, and our physical torca 
J the exercise. Thesulijecl IsperbBps worthy of some attention io selecling aitua- 
tiODs for invalids, but many other causes muat be taken into Tleir, such aa the exba- 
lationa, &e temperature, be. 

15 



OMzcdoyGoOgle 



114 UEAT OR CALORIC. 

9. Influence of pretmre on the escape of gateous ttibstdncet from 
com&ination. 
" When one ^the ingredients of a Solid, or Liquid, u prone to 
tusvvK the aer^vrm state, its extrKolion uiiU be more or less easUy 
effected, in proportion, as the Pressure of the Atmosphere is increas- 
ed, or diminished." 

" If a tall cylindrical jar, containing a car- 
bonate undergoing ihe action of an acid, be 
placed under a receiver, and the air with- 
drawn by an air pump, the effervescence will 
be augmented. But if, on the other hand, 
the same mixture be placed in a receiver, in 
which tlie pressure is increased, by condensa- 
tion, the effervescence will be diminished. In 
the one case, the efibrt of the carbonic acid to 
assume the caseous stale, is repressed ; in the 
other, it is lacilitaied. Hence the necessity 
of condensation, in the process for manufac- 
turing mineral water. Beyond an absorpti(»i 
of its own bulk of the gas, the affinity of the 
water is inadequate to subdiie the tendency of 
the acid to the aetiform state ; but when, by 
exterior mechanical pressure, a great number 
of volumes of the gas are condensed into the space ordinarily occu- 
pied by one, the water combines with as large a volume of the con- 
densed gas, as if there had been no condensation." 

If a gas, under the ordinary pressure of the atmosphere, will com- 
bbe with water in the proportion of equal volumes, llie pressure be- 
ing doubled, the water will combine with two volumes of the gas, and 
if this last pressure be doubled, the volume of gas combined will be 
again doubled ; that is, it will be quadrupled, compared with the 
first quantity combined under the ordinary atmospheric pressure, and 
so on. When thus charged, if suddenly relieved from all the extra 
pressure, bj^ simply opening the vessel, as in drawing sodn water, 
the fluid is violently agitated, because the gas ihat was forcibly com- 
bined, then resumes its elastic form. 



OMzcdoyGoOgle 



HEAT OB CALORIC. 



10. Cold produced by vaporization in vaato.* 
V ether. 




lis 

Water frozen 



" Let a ponion of water, just adequate to 
cover the bottom, be introduced into the ves- 
sel, represented in the subjoined drawing, as 
suspended within a receiver. Over the wa- 
ter, let a stratum of ether be ix>ured, from an 
dgbth, to a quarter of an inch in depth. If, 
under these circumstances, the receiver be 
placed on the air pump plate, and sufficiently 
exhausted, the ether boils and the water 
freeies." 



II. Congelation of water in an exhavtted receiver, by the aid of 
tulphuric add. 

" In the preceding experiment, water is frozen by the rapid ab- 
straction of caloric, consequent to the copious vaporization of ether, 
when unrestrained by atmospheric pressure. In vacuo, water un- 
dergoes a vaporization analogous to that of the ether in the preced- 
ing experiment; but the aqueous vapor evolved in this case, is so 
rare, that it cannot act against valves with sufficient force, to allow of 
its being pumped out of a receiver with the rapidity requisite to pro- 
duce congelation. However, by the process which I am about to 
describe, water may be frozen by its own vaporization." 



* TbiB eiperiment ts neallf performed by placing wtlcr in a witch g\»m upon ■ 
«twid, and covering il wllh a thin metallic cup Into which (hn ether i« poured : oB 
working (he pump, the ether will b(dl> and the water will freeze ; Ihni Ireedng and 
trailing are coincident, and Ihe boiling is the caate of the freezing, and yet Ibe txiil- 
inijliiid is u cold u that witich !■ freeiing. 

Theae eKperimenta are more apt to auccaed promptly if the ether be good ; tt 
il well to wa>h it tivo or tliree times with water in a battle, in a mode to be da- 
acribed hereafter, and if the water which Is aaed for freezini, haa been just formed 
from melted lee or maw. It fraezM «o much the quicker ai [t haa len sensible heat. 



OMzcdoyGoOgle 



HEAT OR CALORIC. 

" A thin dish, or pane of 
glass, corered by a small 
quanti^ of water, and situ- 
ated over some concentra- 
ted sulphuric acid, in a 
broad vessel, is placed on 
the air pump plate within a 
receiver, as represented in 
this engraving. Under these 
circumstances, the exhaus- 
tion of the receiver causes 
the congelation of the wa- 
ter." 

12. WoUattonU Cryophortt$. 
" The adjoining figure represents the Cryophorus, or 
frost bearer ; an instrument, invented by the celebrated 
WoUaston, in which congelation is produced in one cav- 
ity, by the rapid condensation of vapor in another." 

" Li form, this instrument obviously diifers but little 
from the palm glass, already described (4€.) It is sup- 
plied by tne same process, with a small portion of water, 
uistead of alcohol ; so that there is nothing included in it, 
unless water, either liquid, or in vapor." 

" The Cryophorus being thus made, if all the water be 
) allowed to run mto the bulb near the bent part of die tube, 
and the other bulb be immersed in a freezing mixture, 
the water will freeze in a few minutes." 

" So long as no condensation is effected, of die thin aqueous vapor, 
which occupies the cavity of the instrument, that vapor prevents, by 
its repulsion, the production of more vapor : but when, by means of 
cold, the vapor is condensed in one bulb, its evolution in the other, 
containing the water, being unimpeded, proceeds rapidly. Mean- 
while the water becomes colder, and finally freezes, from lodng the 



€\ 



O 



caloric which the vaporization requires. 

" According to Wollaston, one grain of water, converted into va- 
por, holds as much caloric as would, by its abstraction, reduce thirty 
one grains from 60° Fahr. to the freezing point ; and the caloric re- 
quisite to vaporize four grains more, if abstracted fi^m the re^dual 
twenty seven grains, would convert them into ice. 



OMzcdoyGoOgle 



HEAT OB CALORIC. 117 

13. Large Ciyophorut. 

C O 

" This figure represents a very large Cryophorus, the blowing of 
which I superintended ; and by means of which I have successftlly 
repeated Wollaston's experiment." 

" This mstninient is about four feet long ; and its bulbs are about 
fire inches in diameter." 

VI. Ignition ok Incandescence. 

fe.) Bodiet become luminoiu in conteguence of the acaimulation 
at in than.* — In common language, this is expressed by saying 
tfiat bodies become red hot, as a bar of iron does among burning 
coats. 

Some bodies melt during their ignition ; this is the fact with stones 
and most metals, and the melted stone or metal is as truly red hot as 
the bar of ignited iron. Some bodies evaporate during ignition ; 
such are antimony, bismuth, lead and tin ; some evaporate before ig- 
nitioD, as water and most fluids, not excepting the most fixed fluids, 
as quicksilver, and sulphuric acid, and dense oils ; the latter are de- 
composed before ignition. 

Gaiet do not become lumtnotu at any temperature, although they 
may cause solid bodies, as gold, &tc. immersed in them, to become 
luminous, the reason appears to be, that there is not matter enough 
in any one point to project the light to the eye, although Irom their 
communicating igniUcxi to solid bodies, it is certain that they have 
the requisite heat. 

Mr. Perkins' high steam, it would appear, is capable of igniting 
other bodies, (as aheady stated under steam and vapor ;) it kindled 
tow and ropes, and it even ignited the bored orifice in the generator 
from which it was issuing ; still it does not appear certain that it was 
itself luminous, nor is it certain thut it was not, because we cannot 
inspect the steam formed in opake vessels, like tliose of metal, and 
when the steam issues into the air, it is no longer high steam ; just 
at the orifice of emission, it is clastic and bvisible, nut a litde way 
Ixom it, it forms a cloud of mist. 

(i.) Bodiet become luminous by friction. — Glass, or agate, or 
quartz, held against a revolving gritstone or grindstone, become hot 
and luminous. Metals are affected in the same manner. The parts 
of gun locks and other pieces of steel emit sparks when held firmly 
against grindstones or revolving wheels, covered with emery powder 



* Thejr tit not tappoied lo undergo decompositisD duilog tbelr Ignition. 



OMzcdoyGoOgle 



118 HEAT OB CAUUUC. 

Spread upon oiled leather straps, which serve as bands to the 
wheels.* 

(c) All bodia begin to ihine by heal at the tame temperature. — 
This fact was first discovered by Sir Isaac Newton, and has been 
ccHifirmed by others. 

In general, redness, that is the emission of red rays, comraences at 
about 800° of Fahr. and is fully established in broad day light at 
1000° in the direct sun's light, peiliaps about 1100°, or possibly 
1200°, The appearance is of course much influenced by tlie quan- 
tity of the surrounding light. A body might be luminous in the dark, 
that would not be at all so in the light. 

There are many cases of phosphorescence or emisuon of light 
which are not attended by any considerable increase of heat; these 
have been already mentioned under the head of light. 

{*/.) A white heat is only a greater degree of ignition. — ^Vhite 
light, that is, light containing a due proportion of all the colored rays, 
is emitted when the accumulation of heat is the greatest ; a welding 
heat of iron is a white heal. The artisis have many terms to de- 
note the various degrees of heat connected with ^cir processes ; 
thus, they speak of a cherry red, a worm red, kc, and of a white 
heat, a blue white, a red white, he, and there are many degrees of 
heat between, commencing with the feeblest redness visible only in 
the dark, and ending with a full white liglit, distinctiy visible even in 
the blaze of the meridian sun.f 

(e.) Ignition affords one oftlte strongai argnmeatt for the iden- 
tUy of light and heat. — If they are different substances or powers, 
then die neat when accumulated to a certain oegree, espels the light, 
previously lodged in the body ; or, it may be said, that as most cases 
of ignition are produced by burning bodies, the Ught from the fire 
enters the body along with the heat, and thus obtains a transit ; or, if 
heat and light are merely modifications of each other, then it may 
be supposed that at a certain tompcrature heat becomes light, or pos- 
^bly a certain accumulation or intensity of radiant heat affects the 
optic nerves so as to produce tiie sensation of vision. J 

■ This U beautifully loen at the gun manufactory, at Whitneyrille, oeti New 
Haven; Ibe spartis fly off in ianumerHble Ungenlg, and the hand, unless brauglit 
very Dear, may be held in the (tery stream nilhout inemvenienca ; Uila Is douMlea 
ontufc to the strong current of air nhich the revolution of the wheeli produce. It 
ts cunouB tliat while eoane rmenr it used, i^un^owder is inflained by the sparks at 
any distance to which Ihey extend ; but, when very line emery Is used, coarse gun- 
powder is not Idndled, but If liDely pulverized, it then flashes with the nbuleN 
■parks (Communicated by Mr. Eli Blake of Whitneyville.) 

f Although it is called a white hrat, there arc more red rays than are coDlained 

tThe very mild heat which causen the emission of light from some bodies, e. g, 
flilor spar, countenances the opioion that light is loilged Id (hem ; and light may In> 
imparted to sonie bodies to such a degree, that Ihey become partially trmfparent 
without producing, upon the]n,lhe eflecta of ig^itioD ; thus, eggs, the human fingers, 
and other bodies are illumiaated, ttirough aoil through, by an electrical dlachargc. 



c.,i,=ji,G(10glc 



HEAT OR CALOSIC. Ijg 

If we suppose that the entrance of heat continues to expel light 
from a body for an indefinite time, this difficulty is perhaps removed 
by adverting to the fact, already suggested, that at the Kmperature 
of ienitioti, the light enters the body atong with the heat, and dial both 
bodies thus find a transit through it. This however does not ac- 
count for tlie mdefinite ignition [Hoduced by friction ; even allowing 
that it is indefinite, which has not yet be«j proved, th«e is no great- 
er difficulty than attends the indefinite emisstiHi of heat und^ the 
same circumstances. 

Perhaps it would not be usefiil, in a concise text book, to inUo- 
duce the speculations of the learned and able {rfiiloaophers who would 
make heat, uid perhaps light, to depend upon the internal moUons 
of the particles of bodies ; one kind of effect depending itpcm sup- 
posed vibratory, or expansive, or retrocessive, and another upon gy- 
ratory motions of uncognizaUe particleB.* We might quote the 
great names of Newton, Boyle, Hooke, Rumford, I>a»y, Leslie, 
and others. Tlie queaticm can perhaps never be decided ; but in di»- 
cus»ng the nature of light and heat, the statements of facts and the 
reasonings can be exhibited most ctwveniently upmi the supposition 
(hat ^ese agents are material, and diat they are different mim each 
other. This course may therefOTe be pursued provisionally, until 
other views shall be conclusively estabUshed.-f- 

VII. CapacityJ fob hkat, *kd specific beat. 

(fl.) TAe capacity of a body for htat, it itt power ofctmtaimiig a 
given quantity of heat at a given ten^erature.^ — The comparative 
estimate between difieient bodies is usually made, by takkig them 
in equal weights ; but it may be made also upon bodies in equal 
volumes; the numerical results will of course be difiereni, but are 
capable of being intelligibly compared. 

(6.) The ijieeifie heat of a body, is the partintlar quantity of that 
power which tt contains tU a gicen temperature. 



t See Dr. Hare's paper on di« nutertalily of heit, Atn. Jour. Tol. IT. p. 142^ 
md tbe LDarniousduGusaioDB between him and PniieMat(Hmit«d,tD IhcBitne Jour' 
nal, Vols. XI, XII, XIII. Dr. Hare hug ghenn that the fdienomena of heal irs 
bCDnHlBtenl wl<h (be oplaion that they depend upon corpuaeular motioD. Tbere 
KBHis Ilicn lu lie Tio other allernaltre than that there niu!tt be a maleiia] eau»e of 
heal, altha)if(h that Mute ia too Hibtle to he reeognlied by □■ in any other my Ifaui 
by its eflecta. 

i The tBTDi i< BTidently figuratire, and alludea to the capacity of a containing 
venel. The On of the word, tn relatloa to heat, impllei merely a power, without 
deciding od the mode. 

^ For a deacrlplion of that elegant inlrumeat, the Calorimeter of Lavoirier, aee 
bia eleiaeatt, and most of the larger chemical woriu. The quantity of water ob- 
tiiiMd by the fuvtoi of ice, diitiag cerllin Ganges la liodiei lurrouDded by that 
substance, was made the criterion of the quantity of heat ; but there were same, 
perhapt inhereol, sources of error, and the ioitninieiit la now very little, if at all 



DK;,lz=..,C00g[e 



liO HEAT OR CALORIC. 

llie experiments are commonly made by comparing fluids* or com- 
minuted solids, after they have been mingled at difierent tempera- 
tures. That body which, in a given sboH time, has lost the greatest 
number of degrees, has the smallest capacity, and the smallest ^le- 
cific heat, and vice versa. 

The resulting temperature b always nearest to that body, whoK 
capacity or speiufic heat is the greatest, and therefore the greater the 
capaci^ the less the changes of temperature. Boerhaave first dis- 
covered this remarkable fact, with respect to quicbnlver, and water, 
but Dr. Black first established the law ; many other able men bav« 
investigated it, among whom are Wilcke, Irvine, Crawford, Lavoisier, 
Berard, and Delaioche, Petit, and Duking, Clement and Des- 
onnes, kc. 

{c.) Different bodiet, wkethir taken %n eqwd weigku, or columet, 
contain d^rtnt qtmntitiet ofkeat or caloric. 

This coidd never have been known by reasfxiing a priori; the 
conclusions are founded entirely upon experiment. 

{d.) Di^erent bodiet expoied to the tame heating or tooling catue, 
undergo d^erent changes of temperature, m equal ihort tmei, and 
the capaeiitet are inversely om the change of temperaiure. Thus fifty 
spheres, or cubes, equal either m weight or diameter, of as many dif- 
ferent kinds of matter, if plunged into boiling water, and examined after 
an interval of five minutes, would he found very differently heated ; or, 
if already arrived at the temperature of 212°, if they were exposed 
to a freezbg air, and examined as above, they would be found very 
unequally cooled, although in the end, they would in both cases ac- 
quire a common temperature. 

(e.) In homogeneouM bodiea, minghd at different temperatures, the 
remlting temperature u alioayi the arithmetical mean. — A pint of 
water at 100°, and a pint at 200°, would oa being mingled, give 
150° as the resulting temperature, and the same would be true of 
any other fluids, or minutely divided soUds. 

(/.) In heterogenous bodies, the resulting temperaiure is never the 
mean. — The capacity of water is 23 that of mercury 1, for the 
changes which they undergo, when mingled at diferent temperatures, 
and in equal weights or volumes, are mversely as the changes thej 
sufier. 

One pint of mercury at 100° Fahr. +one pint of water at 40°,= 
not 70°, the arithmetical mean, but only 60° ; the metal tosea 40°, 
which raises the water only 20° ; hence, in equal volumes, water has 
the greater capacity. If the pint of water be 100°, and die mercury 
at 40°, the temperature will be about 80°, because the water cm- 
tains more heat than is necessary to raise the mercury to die mean. 

■ Alwajr* taUof H lor pmt«d Ihtt they do not act chnnlcaUr on Mch odier. 



OMzcdoyGoOgle 



HEAT OS CALORIC. 131 

Water linvolume, and mercury 3,=always the aritbmetical mean; 
ft. g. 70^, if the extremes be 100° and 40° ; hence, in equal vcd- 
uroes, water has twice the capacity of quicksilver. 

In equal weights, one pound of water at 100°,-t-oDe pound of mer- 
airy Bt40°=97i; therefore the 2i lost by the water have raised 
the mercury 57}, which is in the proportion of 1 : 33, viz, water haa 
twenty three times the specific beat that is contained in an equal 
weight of mercury, and its capacity is in the same proportiMi,* 

(g-.) Fotvada. — l.Bytneight. — If the weight be raulliplied into the 
change of temperature, the capaci^ will he inversely as tlie change, 
diat is, the greater the change, the less the capacity, and vice versa. 
2. By volwM } the capacity found as above, x into the sp. gr. = the 
capaci^ by volume. f 

(A.) Comparing aatteM <^ bodies, ike capadtia for hxai art, in 

feneral, inverieltf at (heir dennty. — Solids have less capacity than 
uids — fluids less than gases, and vice versa. 

When the capacity is enlarged, heat is absorbed, and when dimin- 
ished, it is given out. 

(t.) The sudden expantion of air alwaw produces cold. — "This 
striVbg occurrence takes place on a vast scale at the fountain of Hiero; 
at the mines of Chemnitz, m Hungary. A part of the machinery for 
working these mines, is a perpendicular column of water, two hun- 
dred and sixty feet high* which presses on a quantity of air enclosed 
m a tight reservoir. The air is consequently condensed to on enor- 
mous degree by this height of water, which is equal to eight or nine 
atmospheres, and when a pipe, communicating with this reservoir of 
condensed air, is suddenly opened, it rushes out with extreme ve- 
locity, instantly expands, and m so doing absorbs so much calcuic, as 
to precipitate the moisture it contains in a shower of very ivhite com- 
pact snow, or rather hail, which may be readily gathered on a hat, 
held in the blast The force of this is so great, that the workman 
who holds the hat is obliged to lean his back against the wall to re- 
tain it in its portion. If tbe cock of the pipe is only panly opened, 
the snow is sull more compact."^ 

B^ condensing aeriform bodies into a small space, cooling them 
by freezing mixtures, and liberating them suddenly, great cold is 
produced by the rarefaction. 

We have found occasion more than once to remark that »milar 
e^cts probably happen in the high«' regims of the atmosphere, from 
the sudden liberation of the ascending currents of rarefied air from 
pressure, and from their mixture with colder currents. 

(j.) Cheat and sudden istcreaieofpressurevponconmion air f evolves 
30 much heat as to ignite very conmuiible bodies. -^-This was exhibit- 



OMzcdoyGoOgle 



123 HEAT OB CALOKIC. 

ed by a brass syringe, furnished at one end nitfa a little chamber^ 
c<Hitainiiig tmder, agaric, or other combusbble, which is heated b^- 
the compression produced by the quick strcAe of the piston, so thai 
the combustible, on being suddenly brought to the air, by the turn- 
ing of a key, took fire. More recently, the combustible is contained 
in the piston itself, which, aAer the stroke, is quickly withdrawn from 
the tube. The instrument is now made of glass, which enables ooe 
to sec the flash. 

(h.) Changet of capacity far caloric have an intimate connexion 
with the regulation of natural and artifidal temperature. — The me- 
dium heat* of the globe is usually placed at about 50° of Fahr. and 
is found, as has been heretofore beheved, at about 1000 feet below the 
surface of the ground. 

Medium beat of the atmosphere at New Haven, about 50°.f 
" " die Torrid zone, 70° to 80°. 
" " " moderate climates, 50° to 62°. 

" " " near the polar regions, about 36°. 

The extremes of the globe are from about— 50° somelimes— 70® 
to 100°, 105°, 110° ; and even 120°, or perhaps in some situa- 
tions, still more. 

The extremes of artificial temperature are much greater, from 
— 91°, to 35137°, {Henry.y which is the highest esumated heat, but 
we know that it is not the highest heat that has actuaUy been produc- 
ed. We have do measure ior it, and probably can nerer have any 
other than the efiects which such heats produce in fusion, be. Hie 
real zero has never been discovered. | 

( I.) Freezing mixtures ad by enUagejoent of capacity. — A sohd, 
as already observed, is always one ingredient in these composidons ; 
it becomes fluid by uniting, chemically, with some other agent, and 
thus absorbs beat and produces cold. Salts and acids, as Glauber's, 
eight oiuices, and muriatic acid, five ounces, are most commonly em- 
ployed, and ^k the thermometer from 50° to 0. -When berth in- 
gredients are solid, the mixture is still more powerful, as in the case 
of muriate of lime and snow ; and of muriate of soda and snow ; by 
^e fonner, mercury is frozen. Snow, or pounded ice, two parts, and 
common salt, one part, depress the thermometer from 50° to — 5°.§ 

The mere solution of n salt in water produces cold. Nitre, in 
lai^e quantities, added to water, sinks the thermometer 17° ; ni- 

* Should the views of Prof. Conliur. u to lh« iDCreuing heat of die loterioT of 
the euih, bo eiUbllahed, the result alatud in tho text cinitot be eorrecl ; but it will 
ivqulre numerau* uid often rcpra(£d alnervitloas, exlendiop; to many countries, 
uid through mtiij yesra, to Mtabtish a coocluiion m> extraordiDary — Bee Am. Jour. 
Vol. 16. p. 109. 

t Prei. Day, in Trims, of Conn. Acjd. 

1 We ihiulf it useless to reltsratc the fruilten diKUMioDs on this subject ; Ibey 
may be IbuDd iu all the larger chemical works. It b evident th«l no reHtitce can 
be placed upon (he nnilts, widely discordant u (hey are. 

J For a mof« copioui tal>le of bt«iinf miiturei, see p. IM. 



OMzcdoyGoOgle 



HEAT OR CALOBIC. 

le parts, a 

37° ; muriate of ammonia, and nitre in powder, wiili from 6ve to 
-eight parts of water, from 50° to — 1 1 ° ; and the salts, recovered b) 
evaponition, answer as well ta before. 

Diluted acids with salts, are more powerful than water only. Sul- 
phate of soda, witli sulphuric acid, diluted wiUi as much water, re- 
duces the temperature from 50° to 5°, and with diluted nitric acid, 
from 61° to 1°. With mixed salts the cold is still greater. Phos- 
phate of soda, a}trate of ammonia, and diluted nitric acid, reduce the 
thermometer from 60° to— 21°, and mercury has been frozen by a 
mixture of nitrous acid, sulphate of soda, and nitrate of ammonia.* 
By these, or umilar means, all fluids have been frozen, except al- 
cohol, and several of the gases have, by the aid of strong pressure, 
been condensed mto fluids. 

The salts should be previoudy well ciystoUized, and should retain 
their frill jiroportion of water ; uiey should he well pulverized ; they 
should be mixed in vessels which are bad conductors of beat ; 
the access of the external air should, as much as possible be cut off, 
and the materials may be previously cooled by being placed sepa- 
rately m other freezing mixtures, taking care that they be not cooled 
below diat d^ree at wnich the materials act on each other.')' 

(m.) Many keat-prodtKiitg, or calorific mwrfwrM, act by diminu- 
titm if a^poGt^;— Sulphuric acid and water combine with increase 
of specific gravi^, and ditninutioa of specific heat, and therefore 
with increase of sensible beat. 

Many other acids, e. g. the nitric, muriatic, fluoric, be. act in th^ 
same way ; even alct^l and water, in considerable quantities, grow 
sensibly warm by being mixed. The heat evolved m tliosc cases 
in which the products of the chemical action are chiefly gaseous, does 
[>ot appear to be well accounted for in diis way. P^tric acid and oils, 
gunpowder and fulminating compositions generally, and mistures of 
Uie chlorates with the combustibles, result in the conversion, more or 
less, of solids into aerial matter, and cold should therefore be genera- 
ted, instead of heat, which is always evolved in great quantities. 

Dr. Turner sums up our knowledge of specific heat under the fol- 
lowing beads. 

I. " Every substance has a specific caloric pecutiBr to itself, 
whence it follows that a change of composition will be attended by a 
change of capad^ for caloric." 

3. *' A change of form, the composition remaining the same, is 
likewise attended with a change of capacity. It is increased when a 
solid liquifies, and diminished when a fluid passes into a solid." 

3. " It is certam that the specific caloric of ail gases increases as 
their density diminishes, and vvx terta, 

' GrahuD. t Murraf. 



, OMzcdoyGoOglc 



HEAT OR CAIX>BIC. 



Mr. DaltOD contends that this law prevails also in sc^ds and fluids,* 
and Petit and Dulong have proved it with respect to several solid^ 
The specific heat of Iron was found (o be 



From 


to 100° 


SpMlfiehemt 
0.1098 





« 200O - 


- 0.1160 





" 300° 


0.1218 





« 350° - 


- 0.1266 


od so of other bodies. 




Mercury, 


Spec. hctU, from 
to 100 woe. 
0.0330 


Sine, hett treo 

Oto800°ce>t 

0.0350 


ZiDC, - 


- 0.0927 - 


- 0.1015 


Antimoiij, 


0.0507 


0.0649 


Silver, - 


- 0.0557 - 


- 0.0611 


Copper, 
PlBtinum, - 


0.0049 


0.1013 


- 0.0355 - 


- 0.0356 


Gl», - 


0.1770 


0.1900 



4. " Petit and Duloog have rendered it probable that the atoms of 
all umple substances have the same specific cak)ric."f 

This is illustrated by a pret^ copious table, for which see tbe 
Ann. de Chimie et de Physique, Vol. 10. 

5. " A change of capacity for Caloric always occa^ms ft change 
of temperature. An increase of the former is attended by a diminu- 
tion of the latter ; and a decrease of the former is attended by an ip- 
crease of the latter." 

Tke tpenfic heat of the gases is an interesting problem. Ac- 
cording to Dela Roche and Berard, several of them stand related as 
follows. 





Under equti 


Under eqail 


Spwlfic 




yolumei. 


w^ightt 


gnvllia. 




1.0000 - 


- 1.0000 - 


- 1.0000 


Hydrogen Gas, 


0.&033 


1.2340 


0.0732 


Oxygen Gas, 


0.9765 - 


- 0.8848 - 


- 1.1036 


Nitrogen Gas, 


1.0000 


1.0318 


0.9691 


Nitrous Oxide, 


3.3503 - 


- 0.8878 - 


- 1.5209 


defiant Gas, 


1.5630 


1.6763 


0.9885 


Carbonic Oxide, 


1.0340 - 


- 1.0805 - 


- 0.9569 


Carbonic Acid, 


1.25S3 


0.8280 


1.5196 



Ch«iD. Phil, ptrt 1. p. to. 

By comparing the equivalenta of twelte principal metala, and of aulphur, u 
n bj Petit and DuIodk. and by Dr. Turner, in hb Clicaiiitry, it hai been found 
. _ the product nriaing frotn the mulltpllcation of thaw equivalents Into the ape- 
dScheatof ihe.bodiea, givea remits ao widely diAerlng fram unUbrmlty, «a ■■ would 
wem to take all plauiibillty from tho hypothesj* that the alonu ofjlmplo bodie* hara 
the same specISc heat."— SoeAc, in Jour. Jtad. JVat. Sei. Fhil. Jan. 1829, 



DMz.djyG00gIC 



HUT OE CALORIC. 



atet bemg umty, the 


specific 


Specific heat of metals, accord- 


heats of ue gases are as fol- 


ing to Petit and Dulong. 


lows. 




Bismuth, - - - 0.0288 


Water, 


1.0000 


Lead, - - - 0.0298 


Almospberic Air, 


0.2669 


Gold, - - - 0.0298 


Hydrogen Gas, - 


3.2936 


Platinum, - - 0.0314 


Carbonic Acid, 


0.3210 


Tm, - - - - 0.0514 


Oxygen Gas, - - 


0.2361 


Silver, - - - 0.0557 


Azote, - - - - 


0.2754 


Zmc, - - - 0.0927 


Protoxide of Azote, 


0.2369 


Telhirium, - - 0.0912 


Olefiant Gas, - - 


0.4207 


Copper, - - - 0.0949 


Oxide of Carlxm, 


0.2884 


Nickel, - - - 0.1035 


Steam, - - - - 


0.8470 


Iron, - - - - O.IIOO 
Cobalt, - - - 0.1498 
Sulphur, - - - 0.1880 



It is worthy of obserration that all the gases, excepting hydrogen, 
have, according to Petit and Dulong, less specific heat than water ; 
this is the fact even with Steam. It would seem that they bad some 
doubts as to the correctness of this result. 

A^araiui for iUuttrating captidties far Heat.— Dr. Hare. 

" Let the vessels 
A,B,andC,besup- 

5 lied with water 
irough the tube T, 
which commmuni- 
cates with each of 
them, by a hori- 
. zontal channel in 
the wooden block. 
The water will rise 
to the same level in all. Of course the resistance made by the wa- 
ter, in each vessel, to the entrance of more of this liquid will be the 
same, and will he measured by the height of the column of water in 
die tube T. Hence if the he^ht of tUs column were made the in- 
dex of the quantity received by each vessel, it would lead to the im- 
pression that they had all received the same quanti^. But it must 
be obvious, that the quantities severally received, wiU be as difirent 
as are their horizcsital areas. Of course we must not assume the 
resistance exerted by the water withm the vessels against a further 
accession of water from the tube, as any evidence of an equali^ in die 
portiona previously received by them." 




OMzcdoyGoOgle 



135 HKAT oa CALOBIC 

VI it. Combustion. 

(a.) In common Umguageit meant the tame aainamatg; titatu, 
in mott catet, the apparent eonmmption* of a body, and an entire 
chaise in itt properties, vrith the enittimt of heat antt lighi. 

(b.) In what teat called the nett or French theory, comtnution mit 
synonmous with a combination <f oxygen with a eomlnutii^ body, 
attended by augmeTitation of itt weight, and change of itt noAire, heat 
and light being at the same time emitted. — Now, Chlorine is added as 
another a^ent possessed of similar powers witli oxygen ; ftlso, by 
some, Iodine ; and many even regard every cage of intense chemical 
action, with the emission of heat and light, as combustion. 

" Whenever the chemical forces that determine either cwnbina- 
tion or decomposition, are energetically exercised, the phenomena of 
combustion, or mcandesceoce, with a change of properties, are dis- 
played."f 

In general we shall use the word combustion in its common and 
more restncted sense, taking due notice, however, of the other cases 
as we come to them. 

(c.) It would be prematilre to contider combustion fully at pre- 
sent ; for its theory and phenomena are best developed progressively 
as we proceed. 

We mention combustion in this place merely to complete our list 
of the effects of heat ; for, as commonly seen, it sustains a very close 
connexion mth heat, since an exalted temperature is usually neces- 
saiT to its existence. Heat is, however, often the consequence, as 
■well as the cause of combustion. 

{d.) Phlogiston is a name formerly given to a prinaple cf com- 
hustion, supposed to reside in all injlammable bodies ; dissipated, as 
was imagined, in the form of heat and light, during combustion ; the 
body being tliereby rendered uninflammable, and its inflamraability 
being again restored by recombiniiig with plilogiston, as when red 
lead is heated with charcoal which causes the incombustible meialUc 
oxide to become again combustible in the form of metallic lead. 

This theoryf is now obselete, but in its time, it rendered impOTtaot 
service to ilie science of Chemistrj', and was in vogue for a century- 
Phlogiston comes very near to the modem idea of combined and free 
caloric. If we substitute a combmaiion of oxygen for the extrication 
of plilogiston, and the extrication of oxygen for the combination of 
phlojgiston, we translate, very nearly, all the common cases (rf" com- 
bustion, from one theory into the other. 



OMzcdoyGoOgle 



SOURCES or HEAT AND COLD. 127 

' ATFENDIX TO CALOUC. 
SEC. at. SOVBCES OF HEAT AND COIJ>. 

L SouBOBs or BEAT ; mo*t ofwhitJi are <d*o toureet of light. 

(a.) The suit. 

h.j CotiJutttioH. 

ic.) Chemical action without combtution. 

id.) Electricity and Galvamm. 

fe.j Condeiuation of Mriform bodiet by pretsure. 

(/.) Condetuation of lolids, by mecKanical action, ind-ading 
friction and perciunon. 

(g.) yU<u action. 

(a.) 7%e lolar rayt. — The intensity of the solar heat being in pro- 
portion to the rajs that can be coUected upcm s given spot, there ap- 
pears to be no other limit (o our power of generating heat in this 
muwer, than what is found in the size of our instnuneitts, and the 
difficulty of using them, for it has been long known, that the efieot is 
much increased by lenses and mirrors.* 

This is especiaUy true if the focus he received on a black and 
rough surface, e. g. on charred cork lining a box, and covered by 
glass ; dius a heat of 231°, vras produced while the air was only 75°. 
■— Sauwure. — ^In another case, the heat generated by similu meani^ 
was from 230° to 337°, while a bright firo gave, at the same time, 
213°.— B/aot, Kofwon. 

Dr. Hare remarks, that previously to the discovery of the heat ex- 
cited by oxygen, by the compound blowpipe, or by the Voltaic series, 
there was do known mode of rivalling the heat produced \^ \n%e 
buniii^ glasses and mirrors. These have been already mentioned, 
perhaps sufficiently, in the account oS heat and light. 

It is not b our power to say what is the nature of the sun, and for 
aught we know, the popular opinion that his body is a glpbe of ignited 
matter, may he correct, f 

{b.) Combtution.— Mtei the solar influence, this is the most im- 
portant source of heat ; it is very completely under our command ; 
It can be applied when and where we please, and varies from ex- 



* Dr. Hire. 

t Dr. Herachel'* idea* of the nature oTthefDD, were peculiar. He supposed Sit 
nm'i twdr to Im ofwke ; that U* ttmcMpheN tiaa two *tnCm of cloud* ; (he one ap*ke 
and tbe other pluMpboreiccDt ; tlie Utter he luppooet to be Iha faighesi, and thatthey 
emit Ihe llghl ; that when (he cloudi ore broken and rajcgcil, tbe sun's opake liodjr 
]a aeen thranch the clouds. The fruttAilnsM of different Beasonn he supiioHd to be 
coBnertad wiih flu quantily of liglit enilltal from the luniinoiu cleada of the aUD. — 
Phil. ZVofU. 1801. 



OMzcdoyGoOgle 



1S8 SOURCES OF BEAT AND COLD. 

trenie mildness to extreme inienaQ'. Common fires, in fire places 
and stoves ; Argand's lamp ; oil lamps ; spirit lamps ; gas lignts ; a 
smith's forge ; the furnaces of the arts and of the laboratory ; can- 
dles ; the mouth blovpipe, and ttiat fed hj oxygen and hydrogen 
gases, are all familiar instances, in which combustion is seen. 

Combustion is mentioned with propriety, both as a source and as 
an effect of heat ; for generally, it does not ccunmence and proceed 
without an augmented temperature, and it raises the temperWure b 
turn. 

I shall omit the description of comman furnaces, and subjoin that 
of the followtng instrumraits. 

1. 7%e Month Blowpipe.— Dr. Hare, 1 to 7. 



" As fii« is quickened, by a blast from a bellows, so a flame may 
be escited by a stream of ak propelled through it from the blow- 
pipe." 

" The mslnmient, known by the abovementioned ^pellatian, is 
bere represraited id one of its beat forms. It is susceptible of rari- 
ous other constructions ; all that is essential being a pipe of a size at 
one end suitable to be received into the mouth, and towards the 
other end, having a bend, nearly rectangular, beyond which the bore 
converges to a perforation, radier too small for the admis^on of a 
common pin. There is usually, however, an enlargement, to catch 
the condensed moisture of the breath, aa in this figure." 

BerzeHus has in an octavo vidume, illustrating the extreme utili^ of 
the mouth blowpipe, with which Gahn discovered tin in a mineral 
ccHUaining only one per cent., which had escaped detectiw by an- 
alysis ; and he extracted also copper from the ashes of a quarter of 
a sheet of paper. 

3. Lamp mthout a fiame* 
" About the nick of a spirit lamp, a fine wire of 
platina is coiled, so as to leave a spiral interstice be- 
tween the parts of the spiral formed by the wire ; a 
few turns of which should rise above the wick." 

" If the lamp be lighted ; on blowing out the flame, 
the wire will be found to remain red hot, as it re- 
tains sufficient heat to support the cunbusti(»i of the 
alcoholic vapor, although the temperature be inade- 
^quate to constitute, or produce bfiammation." 

' S«e Am. Jour. Vd. IV. p. S2S. 




OMzcdoyGoOgle 



SOURCES OF HEAT AND COLD. 129 

" Instead of blowing out the flame, it is better to put an extin- 
guiaher over it, fcv as short a time as will cause the flame to disap- 
pear. For this purpose, 8 small phial^ or test tube, is preferable to 
the metallic cap usually employed." 

" The metallic coil appears to serve as a reservoir for the caloric, 
and gives to the combustion a stabili^, in which it would otherwise 
be deficient." 

" There is some analogy between the operation of the wire, in act- 
ing as a reservdr of beat in this chemical process, and that of a % 
wheel, as a reservtMr of momentum, in equalizing the motion of ma- 
chinery." 

Dr. Hat« introduced a Mowpipe, in wlijch the air was propelled 
by hydrostatic pressure ; and in this manner he used also the oxygen 
afid hydrogen gases.* I have faattd such a blowpipe very useful, 
And it win be mentioned again in this work. 

'Fiue blowpipe of the enameler and of the thermometer maker, is 
fed by a dotri>le bellows, worked by the foot, and terminates in a 
pointenl tube, which rises above a table, and thus supplies a lamp. 
3. Alcohol Btourpipe. 
8 "A flame resembling that 

of the enameler's lamp, may 
be produced by a small boiler, 
A, containing alcobol, in which 
alcoholic vapor is generated, 
as steam is, by the boiler of a 
steam engine." 

" The vapor thus generated 
is substituted for air in the blast 
of the bbwpipe, being directed 
upon the name of a lamp in 
the same way, by means of a 
pipe proceedbg from the boil- 
er, and terminating in a beak, 
with a capillary oHfice, B. 
ihe boiler is furnished with a 
safety valve, V." 
"It may be objected to flame thus excited, that as the oxygen is 
lot so copiously supplied, as when a stream of air is used, the oxide 
of lead in flint glass tubes is reduced by it, and the glass consequently 
blackened." 

" The apparatus here represented, is furnished with an adjusdng 
screw, S, by which the height of the boiler is regulated ; while die 

See his CorDpeDdliioi, p. 73. 



D„tiidD,Googlc 



130 SOURCES OF HEAT AND COLD. 

communicBtion is preserved between it and die beak, by means of a 
tube sliding through a stuffing box, C, which surmounis a larger tube 
to which the beak b soldered."* 

4. ^ new modification of the Blowpipe by Alcohol. 

" This figure represents an improv- 
ed blowpipe, by alcohol. In the ordi- 
nary construction of that instnimeiU, 
the inflammatkin is kept up, by pass- 
ing a jet of alcohohc v^x>r Uiraugh 
the flame of a lamp, supported, as is 
usual by a wick. The inflaimnatioD 
of the let cannot be sustained with- 
out the heat of the lamp flanie ; since 
the combusticHi does not proceed with 
sufficient rapidity to prevent the m- 
flamed portion from being carried too 
far from the orifice of the pipe ; and 
being so much cooled by an admix- 
ture of air, as to be extinguished. 
By using two jets of vapor in opposi- 
tion to each other, I find the inflam- 
mauon may be sustained without a 
lamp. If one part of oil of turpen- 
tine, with seven of alcohol be used, the 
flame becomes as luminous as a gait 

light." 

" In order to equalize and regulate 
the efflux, I have contrived a boiler like a gasometer. It consists of 
In'o concentric cylinders, open at top, leaving an interstice of about 
one quarter of an inch between them ; and a third cylinder, open ai 
bottom, which slides up and down in the interstice. Tlie interstice 
being filled with boiling water, and alcohol introduced mto the inner- 
most cylinder, it soon boils and escapes by tlie pipes. These pasf> 
through stuffing boxes in tlie bottom of the cylinder. Hence their 
orifices, and of course tltc flame, may be made to approach to or re- 
cede from die boiler. It must be obvious tbat ttie introduction of die 
alcohol requires the temporary removal of tlie intermediate cylinder." 



" stuffing box i9 Ihe technical name jiivcn by mccbanicg la > small hollow me- 
r. cylittdc, ill niiidi, by mi-ans of nnuther rylindcr acted upon by screiCK. wnc 
in, tow, leather, or oilier clastic ■uli-lance, is packed about a rod, m> u 10 alloH 
move to and fro nithoul periniltin^ any fluid li> escape from the vc9m1 into which 



D„tiidD,Googlc 



SOURCES OF HEAT AND COLD. J31 

(c.) Chemical action without comluslion; that is to say, without 
combustion to begin with ; combustion is Dot used as a means of rais- 
ing the heat, altliough this mode of evolving heat may end in com- 
bustion, provided any ingredient iti the mixture is combustible ; e. g. 
as in the case of nitric acid acting on alcohol or oils, dense or vola- 
tile. Fermentation of hay may produce combusUon. 

Spontaneous combustions proceed in many instances, from chem- 
ical acdon, as in cases where oils, tallow, paints, and similar sub- 
stances, are in contact with flax, cotton or hemp. Tanner's bark 
and horse manure, by fermentauon, produce heat for tlie green 
house, and for some processes in the arts. 

Most of the cases under this head belong to capacity and specific 
heat, and the doctrine has been partly anticipated. Many more in- 
stances will follow. At present I add only the following from Dr. 
Hare. 

5. Soiling heat produced, by tlie mixture of sulpkurtc add with 



" Into the inner tube, represented in tlic 
adjoining figure, introduce about as much 
alcohol, colored, to render it more discern- 
ible, as will occuf^ it la the height uf three 
or four inches. Next pour water into tlic 
outer tube, tiU it reaches about one third as 
high as the Uquid within ; and afterwards 
add to the water, about three times its 
bulk of concentrated sulphuric acid. The 
liquid in the inner tube will soon boil vio- 
lently, so as to rise in a foam." 



6. Chemical combination, attended by dtcomposiiton, as the Tiieans 
ttf evolving caloric. 

" Instances of that species of corpuscular reaction, which comes un- 
der this head, will be bereafier mentioned in their proper places. The 
oxnication of caloric, which b usually more or less a consequence of 




OMzcdoyGoOgle 



133 SOURCES OF HEAT AND COLD. 

intense chemical reactkiD, is a collateral, rather than a neceisary con- 
sequence of it. 

" As an example in which caloric is rendered senile, by the 
method in question, the inflammation of turpentbe by a mixture of 
nitric acid, with sukihuric acid, may be adduced.*' 

" The inflammation of alcohol, or oil of turpentJoe, by means of 
a chlorate and sulphuric acid, as represented by this figure, affivds 
another exemplification perfectly in point." 




" About as much chlorate of potash as may be piled upon a half 
cent, being deposited in a heap, in the inflammable liquid, and con- 
centrated sulphuric acid being poured upcu the heap, die liquid is in- 
flamed." 

" As portions of the liquid are sometimes projected into the air, in 
a state of inflammation, it is expedient, for the security of the open- 
tor, to have the glass, used to conrey the acid, fastened to the end of 
a rod." 

{d.> EUctricity and OaJtanwm.— The modes of excitement are 
pecubar ; generally they are well known, but they belong either to a 
difierent science, or to a different part of this science. 

The applications of the heat evolved in this way, are extremely 
useful to the chemist ; the power is conveyed, conveniently, into and 
dirough the interior of vessels, and thus gives us a furnace heat with- 
out its inconveniences. The heat is mild or miense at pleasure ; no 
heat, probably not even that of lightning, exceeds that produced by 
electrical and galvanic arrangements. The decomposing powers ctm- 
oected willi common and galvanic electricity, produce the most curi- 
ous and important results, dividing the matenal world betiveen the 
opposite poles, but this part of the subject is not appropriate to the 
present topic. The facts and the iosnruments rehuuig to Galtanism 
are reserved for another place, except that I shall introduce her^ 
Jroni Dr. Hare, an instrument equally simple and usdnil, 



OMzcdoyGoOgle 



SOUBCXS or HEAT AND COLD. ]33 

7. Thegalt»n»f^vnu,org<dmniei>iiitiiuiefi>r thtebe&cfiurm. 



« The preceding figure represents an instrument for ifnitiBg a 
lamp, by means ofa galvamc discbarge, from a calorimoioc." 

" The ^unger, P, being depressed, by means of the handle at- 
tached to It, some acid, contained in the box, B, is displaced, so w 
to rise among the galvanic plates. By the consequem evolutioD of 
the galvanic fluid, a platina wire (fastened between the braas rods 
forming the poles of the calorimolor, and projecting over the limp as 
seen at R,) is rendered white hot, and a filament of the wick pre- 
vious^ I«a upon it, is inflamed." 

" "rtie weight, W, acts as a counterpoise to the phinger, and keeps 
it out of the acid, when it is not depressed by the tumd." 

{e.) Cmdauation of wir^orm bodies 6y preuwt and cold. 

This tofic is already anticipated under specific heat and vapors^ 
Vapors and gas mechanically condensed, as by the syringe and piston^ 
pve out heat; vapors impan heat to colder bodies, as ui the distilk 
ing ai^aratus with its ooodenser, aheadv mentioned. ConMMwsed 
oxygen and chlorine give out light, and these gases are s«d to be 
the only simple ones that become luminous by pressure, 

(/.) Ctmiauaiion ofiolida by mechunical action ituhtding Jrie~ 
Hon and parcnstion. — ^The flint and steel m collision, or two quarta 
stones struck forcibly tt^etber) any hard stone firmly held upon a 
revolving grit stone ; the vigorous rubbing together of two slicks ; the 
friction ofbranchcs of trees in stormy weather ; of axles in carts and 
wagons and of various parts of powerful machinery ; of the axles in 



D,q,fzodbyGo(lg[e 



134 SOURCES OF HEAT AND COLD. 

sheaves or blocks of runniDg tackle* on board of ships ; of ropes, pass- 
ing rapidly over a gunwale, as when a whale is harpooned ; friction in 
the boring of cannon and muskets ; of a rope running rapidly through 
the hand ; of the hand rubbed on a stair rail, or on one's woolen coat 
sleeve ; at) these and many others are instances of heat evolved on 
this principle. 

llie rotary match box gives sparks by the collision of o rapidly revol- 
ving steel with Sint, and a similar instrument called the steel mill, was 
used to give light in coal mines before the invention of the safeQi lamp. 

An iron bar grows hot enough, by vigorous hammering, to kindle 
shavings, and lead will by the same treatment kindle phosphorus. 

Wood, in rapid revolution, " may be carbonized throughout the 
circle of contact, by holding against it another piece properly sharp- 
ened, and one cork rubbed against another will become hot enough lo 
kindle phosphorus."f A disk of soft iron rapidly revolving by ma- 
chinery, will easily cut in two| tlie hardest steel saw plate, or the 
best file. 

{g.) Vitai aclioH. — ^This is evidently a source of heat, although 
in a way not perhaps fully understood. There can be no doubt that 
oxygen, acting in respiration, is an important agent in producing and 
sustaining it ; it appears probable also that secretion, connected with 
the influence of the nerves, is concerned, and some iacts countenance 
Ae opinion that galvanic agencies are not dormant. 

Whatever may be usefully said on the latter subject, belongs to a 
more advanced stage of this work. 

n. The souacES of cold. 
1. Evaporation, 
3. Rarefaction, 
3. Chemical action. 

1. Evaporation. — The general facts on this subject have been al- 
ready stated. Whenever a body passes to the aeriform state, it ab- 
sorbs heal to turn it into vapor, and thus cools the contiguous bodies. 
Sensible cold is produced by the evaporation of water, more by that 
of alcohol, and most of all by that of ether or carburet of sulphur, 
or liquid sulphurous acid, whether measured by our organs or by the 
thermometer. We have already seen that water is frozen by the 
evaporation of ether, both in the exhausted receiver of the air pump, 
and in a tube in the atmosphere. The mercury in a thermometer 
ball, wet with water and having a current of air blowing mxm it, 
will fall 6° J if with alcohol, 12°, wid if with ether, 3f3P. -Murray. 

' See Lt Glynn la Am. Jour. Vol. XIV, p. 196, and Capt. Parrj's2d yoytgt, Jiev 
York Ed. p. 212. " The nelzht ot (he ice every msmeDt iDcretilDg, oblind nt 
to veer on the bawaen, whose IHcdon wu aogreitM nciriy lo cul (hroagb the Irfl 
Imdo, and itttirQately set them on fira, aa that It became requlilCe for people to *!■ 
tend with bQcketa of water." — Parry. 

* Dr. Hare. I See Am. Jour. Vol. VI, p, 836. 



OMzcdoyGoOgle 



SOURCES OF HEAT AND COLD. 135 

With a rapid exhaustion by the air pump, mercury in a thermome- 
ter ball, if the ball be wrapped in flanuel or fleecy hosiery and dipped 
n ether br sulphuret of carbcm, will be frozen in two or ihree minutes. 

Evaporation b very extensive in its natural operation, and its uni- 
versal prevalence is one of the great causes which prevents the accu- 
mulation of heat on our globe, and which therefore tends very much 
to preserve the equilibrium of its temperature. It is also occa^on- 
ally of use in the operations of art, and is sometimes employed as we 
have already seen, to depress the temperature of paniculBr bodies. 

2. Rarefaaion. — This is intimately connected with evaporation, 
and depends upon the same principle. As condensation produces 
heat, so rarefaction generates cold. It is seen chiefly in the aeriform 
fluids. The remarkable example at the fouDtain of Hiero, has been 
already mentioned. In air pump experiments, the thermometer falls 
several degrees, and Dr. Darwm observed, "that if, in the stream 
of air issuing from the receiver of an air gun, in which it had been 
compressed, a thermometer were placed, it sunk from 5° to 7'^." 

In the fit^i instance, it produces heat by its condensation, and in- 
stantly after, cold by its rarefaction. 

Air, condensed into a reservoir and suddenly liberated from an or- 
ifice, produces a considerable degree of cold : Gay Lussac found it 
equal to 5(P of Fahr.* 

If heat must be absorbed in evaporation or gazification, in order to 
produce an aeriform body, more heat is required to enlarge its btdk 
after it is produced, and, as its particles are repulsive, when the pres- 
sure which retains them within a certain distance is diminished, the 
particles recede and caloric is absorbed, for, otherwise their repellent 
power could not be m^tained at increasing distances, and they would 
again approach ; when they are forcibly brought together anew by 
compression, the heat is again given out. 

3. Chemical action. — Cold is produced during the chemical ac- 
tion of those .substances whose capacity is by the union enlarged, 
and which therefore absorb caloric. The immediate eflect of chem- 
ical union is a mutual penetration of particles, and therefore an in- 
crease of specific gravity, and of course an emergence of heat ; but 
it often happens also that there is an enlargement of capacity and the 
absorption of heat which follows from this cause, is frequendy suffi- 
cient to generate a considerable degree of cold. Sulphuric acid and 
snow afford us an illustration of both these remarks; when first min~ 
gled they produce heat for an instant, owmg to the energy of their 
combination, but immediately after, cold is produced because water 
is of the capacity of ten for caloric, while ice is only nine. 



OMzcdoyGoOgle 



iOURCES OF H&AT AND COLD. 



I 

h 



h 



1^ 

s 

Si * 

1 + 
ill 



"IT 



Hi 



•11 : 

SI 



":fl 



S1^ 

m 

111. 









la 



nSj 



"TIT 



Sill 
I I 

sis 
+ + 



Hi 



■sa" 



III .11 
|lif|| 

I; ^1 

k if 



3i.= 3 



Sill 



Ul. 



Ill 



i\ 11 
li ^"^ 



D„tiidD,Googlc 



ATTRACTION. 



BEC. IV. ATTRACTION.' 



By attraction, vk mean the tendency ofhodiet to approximate, and 
ubo the unknoion muse of that tendency. — In its most general sense, 
it extends to atoms and mnsses reciprocally, and to every distance. 

It is the bond of the universe ; it appears to depend in general on no 
proximate cause, bot to emanate at once from the will of the Deity- 

Coimieracted and modified by the powers of repukion and pro- 
jection, it keeps every thing in harmonious equilibrium. 

It is unknown wbedier it arises, in all its varieties, from the modifi- 
cations of one cause, or whether tliere are several, giving origin to the 
different kinds of attraction. 

However this may be, it is most convenient to consider the sub- 
ject under diSferent heads. 

1. Gravitation. 

3. Maonetism. 

3. Galvanic electricitt. 

4. Cohesion and aggregation. 

5. CbEXICAL attraction oh AFFiNITT. 

1. Gravitation. 

(a.) It extends to every tlang, to all quantities of matter, and to 
aU distances. 

(h.) Its force is directly as the quantity of matter, and inversely oi 
the square of the distance. — ^The quantity of matter, in different 
cases, being as 1. 2. 3. 4, the attracting force at a given distance, mil 
be as those numbers directly ; but the same body being placed suc- 
cessively at the distances 1. 2. 3.4, the attracting force will be ex- 
pressed inversely, by 1. 4. 9. 16, that b, at the distance 2 it will be 
4, at 3, i, and at 4, y'^, as great as it was at the distance 1. 

We are familiar with the effects of gravitation, and therefore re- 
gard them as natural ; they are so to our habits, but only in obedi- 
ence to an established law ; if the law had been diSerent, our habits 
would have been accommodated to it. 

Were there no attraction towards the earth, a stone thrown into the 
lur would not return, and would stop only from the resistance of some 
medium, or o( some other body which it might encounter. 

(c.J TVie prtgectHe power modifies the graviiating force, so that 
the planets move in elliptical orbits, and neither faU to the centre of 
motioD, nor move off in tangents to the curve of the orbit. 



le ntno conne in ihb worli. 



D„tiidD,Googlc 



138 attraction. 

2. Marnetish. 

(a.) TkU M a power usually manifested in iron orsteel, after hav- 
ing received particular treatment, or after having been for some time in 
a particular position. 

{b.) It belongs also to nickel, and to cobalt, which like nicke), 
is found to be the more magnetic, tlie purer it is made. 

(c.) Magnetism resides also in the earth. — The magnetic poles are 
not coincident with the poles of revolution. In the Arctic region, 
the magnetic pole is* in 69^ IG' of N. lal. and 98° 8' W. lon.f 

(d.) Repulsion as well as attraction is predicable of magnetism, 

(e.) Similar magnetic poles repel, and oppoiite poles attract. 

(f.) Magnetism is connected, tn some mysterious manner, untk the 
other imponderable pouxrs, light, heat, and ehctrictly. 

(g.) The solar rays, especmlly the violet, magnetize a Tieedle.^ 

(A.) The calorimotor evohesheat with great energy, but its elec- 
tricity is of a very low intensity ; still, it magnetizes needles power- 
fully, when there is no light perceptible. 

(t.) Similar effects, in a greater or less degree, are produced by 
all the varieties of galvanic apparatus ; all the known imponderable 
fluids being occasionally present together. 

(J.) We cannot say, therefore, whether magnetism u a distinct 
power, or a property or oppeTtdage of one or more, or of all the other 
imponderable powers, — The magnetic power, both in its attractions 
and repulsions, is pleasingly exhibited by magnetic needles, fish, boats, 
and balls, by the horse shoe magnet, bar magnet, inc. Many articles 
of iron and steel become magnets spontaneously, especially such as 
have stood long vertically or nearly so, and more especially, if in the 
magnetic meridian. Magnetism is excited also by rapid rotary mo- 
tion. 

3. Galvanisu 

1. Requires, and will receive a distinct statement near the end 
of this work, but as this remarkable power actually arranges in a 
natural method, all the elements and compound principles of matter, 
it is mentioned iierc among tiie general powers. 

{a.) Mode of cTcitement. — Nearly as various as matter, almost all 
substances of different natures, or sometimes the same substance in 
different conditions, arranged in a particular connexion, will serve to 



* Or was at Ibe lime of Captain Parry's lale voyagei ; 1 know Dol irhelher any 
nbservBlinriB have since been made, (o atceruin its conslaocy in latitude ; Ibe Turia- 
lioni of Iho needle E. and W., seem Id prove that Ibe magnetic pole varies in longi- 
tude. i Am. Jour. Vol. XVi.p. 1J9. 

J MorrichiQl's and ^[^s. Somerville'i experimcnta on magnetliting needles, are 
Raid to have failed in ihilliil bauds ; it is suc^irted that the needles might have baen 
magnoUzcd liefore. Tbe editor of lite Pltitos. Mogaune, neiT series, Vi^. IV, p. 
221, thiuks that, at least, the magnetism nas iacreas^. 



OMzcdoyGoOglc 



render this power perceptible. Common electricity is also exciied 
in many ways, but most usually by die friction of glass or re^n. 

(A.) Mode of exciting the Voltaic power.— -Cenain combina- 
tioDs of metals, usually zmc and copper, witli fluids, especially saline 
and acid fluids, producing opposite polarity at the two extremes 
of the series. 

(c.) Mode of receiving aud trantmilling the poioer. — By conduc- 
tors, uniting tbe poles ; tbey are commonly wires, and are often 
pointed mtb well prepared charcoal. 

(d.) JVature of the power. — It has been commonly ree;arded as 
the same witii electricity ; like that it is attended by light, heat, and 
magnetism, variously modified and combined in different propordons, 
in different kinds of apparatus ; so ihat one predominates in one kind 
and another in another. It Is clear Uiat it is not electricity merely. 

(e.) Sensible and demonstrable effects, — Attractions nnd repul- 
sions, as in common electricity ; similar poles repelling and opposite 
attracting. All elements and all compound principles, when placed 
in the electro-galvanic circuit, being for the time endued with polari- 
ty, chemical decompositions are thus produced. Alusciilar sliocks 
are also among the effects produced by tliis power, as well as light, 
heat, and magnetism, which have been already mentioned. 

(/.) Mode of effecting the decompimtioiia, by bringing the con- 
necUng points into contact with tlio pardcular substance. 

{g.) Clauification of the elementary bodies. — Oxygen, iodine, nnd 
chlorine, are anracted to the positive pole, and are therefore said to 
be electro-negauvc. 

The combustibles and metals are attracted to the negative pole, 
and are therefore said to be electro-positive. 

C(A.) Clanification of the principal proximate prindplei in the com- 
ad bodia, — The acids go to the posiuve pole ; the earths, alka- 
and oxides of meials, to the negative. 

(».) Galvanic electricity is a pmeerfid agent in decomposition ; it 
is more energetic, and it is also more manageable than cemmon elec- 
tricity. 

(y.^ The arrangement of the prindplea of bodies under this pow- 
er, will be mentioned as we come to them mdividually. 

[k.) The other effects are not material in our present state of ad- 
vancement ; thw-^pll be mentioned in their proper place. 

It is supposed, tnat'the electrical and magnetic attractions are gov- 
erned by the same general law with grantatJon. 

4. Cohesion — adhesion — agghegatidk. 

(n.) Cohesion is a union of parts, imtbout change of properties. 
—The particles of a bar of iron cohere ; this force gives die iron 
its strengtli ; those of water cohere but Ibebly ; hence it has no 
strength ; those of racist dou^h cohere more than water, 6ic. These 



OMzcdoyGoOgle 



140 ATTEACTION. 

are ezampks of union where the minutest parts are of imperceptible 
magnitude . 

Adhetion* — Two plates of glass or two of metal, or wie of glass 
and one of metul, when moistened or oiled, adhere, with considerable 
force ; with still more force, two leaden hnni^eres made by split- 
ting a bullet, and pressing the surfaces together with a wringing ex 
twisting motion. If furnished with hooks, the parts of the bullet may 
be suspended, and will support a considerable weight that may be 
gradually increased for some time, before the hemispheres will part.f 

(6.) Tht cokeaion of homogeaeou»X partides w oflen termed aggre- 
gation, and masses made up in that manner are said to be aggregates. 

(c.) The word adhesion may be tued to denote the union between 
lurfacet of perceptible magnitude, tehether imHar or dissimilar m 
their nature, 

(d.) Cohesion produeei augmxntatvm of volume, and frequent- 
ly a change in form, but no change in properties. — ^The dust of mar- 
ble is tlie same substance with the stratum or mountain of marble 
which afibrded it ; it contains the same elements, and in the same 
proportions. The elements arc united by affinity or chemical attrac- 
tion ; the compound particles produced by the union of the elements, 
are united by c^esion. 

(e.) Adhenon ofstafaees ofperc^tibte extent produces no change 
la properties. — Generally the union of such surfaces is feeble. That 
particular mode of corpuscular union which is called cohesion, is the 
source of the difierent strengtii of materials, as of lead, iron, wood, fee, 

(/.) The attraction Khich produces the union of particles is often 
called corpuscular attraction. — It is quite immaterial whether the par- 
ticles be simple, as tiiose of single metals, or compound as those of 
metallic alloys or wood ; in either case, the state of the body results 
from the union of minute particles, which are for this purpose regard- 
ed as mechanically simple, whether chemically so, or not 

The union of dissimilar particles, as will be hereafter seen, is re- 
ferred to cliemicai action. Chemical union may first connect dis- 
similar particles, as tmc and copper ; and the compound, which is in 
that case called brass, is composed of particles, tliat are regarded as 
mechanically simple, and are called btegrant particles ; while the 
others are called constituent particles. 



t Thii oHect evidenlly depend), in part, upon Ibe furrows on the aurhce of (he lead 
which are brou^hl lutu cIimc contact by Ihe twiM thet is given in prening Ihem to- 
gMher, wilh b screwinfc motioD ; when poli'-hed, il is dlHicuU )a roake them adhere. 

t HelerDgeoeDUi particles will ilso uui'i;, hut O.k r^'iult i<, not la segregate ; it is 
■ new bedy, nlioie particles are connected not by mechunical, but by diemical at- 



OMzcdoyGoOgle 



ATTBACTION. 141 

(G.) CkTSTLLLIKATION is the aEBOLT OT TSe ATTRACTION OF 
AOGaEGATlOH. 

(A.) Aerytlaliaa symmetrical ifiid, produced by the union of in- 
tegrant partielet* 

(t.) S'atural cryttaU art nitmerou*, and art produces manymore; 
every good mineral cabinet exhibits great numbers of the former, and 
every good chemica] collection of the latter. 

(_;.) Datruction or great diminution of (A« power <f cohesion 
it an inditpenmble prelimi)iary.— This is cycled either by so> 
liition in a fluid, or by the »id of heat producing fluidity or the state 
of vapor. In the former case, it is necessary to drive off part of the 
solvent by heat ; in the latter, merely to allow the fluid to cool, or the 
vapor to be condensed, in order that crystals may be formed. Cer- 
tain circumstances are, however, necessary to be attended to in order 
to success. If tlie solvent be very rapidly expelled by the aid of a 
high temperature, or, if the fused body be suddenly exposed to an in- 
tense cold, eitlier a shapeless mass will be formed, or only confused 
and irregular crystals. In general, fine crystals are obtained only W 
oldw evaporation and by slow cooling. Water and most of the metab 
are examples of bodies that crystallize by a mere reduction of tem- 
perature. A saturated solution of sulphate of soda, boiled and cork- 
ed in diat state, does not become solid on cooling, but on letting in 
Uie air ; agitating it by a jerk or jar, or dropping in a crystal, it con- 
geals and heat is evolved, sufficient to melt it again. If a string or 
mark be placed on the oeck of the vessel, it will be seen that the mass 
has been expanded by the crystallization. It does not appear that it 
is the mere pressure of the air, as ivas foi-merly supposed, that pro- 
duces the crystaUizBtion ; tlie air seems to act as a disturbing force, 
or perhaps by the introduction mtli it, of some foreign body, which 
may serve as a nucleus. f A gentle waving motion does not cause it 
to congeal. The salts are crystallized generally by diminishing iJiC' 
qtianti^ of the solvent, that is, by evaporation, or by conjoining both, 
diminishing the solvent by evaporation and reducing the tem- 
perature ; or, when a particular portion of a salt has been sus- 
p^ided by the aid of an elevated temperature, a simple reduction 
of temperature is sufficient, without evaporation. For, an elevated 
temperature increases the power of most solvents. Common salt, 
however, being dissolved in nearly equal quantities by cold as by hot 

* That a of p>rticl«« of the Baine kinil, but these particles may be chemle&lly,. 
either slniple or compound. 

I A paint or almoal uiy solid frequently determino* Incipient cry alii lizalion ; 
■0 It jar or sudden vibratory motion brliigs (he parliclei into such a poaition, tbtt 
their polar Bttractloni become effectual, and the nci^tive pole of the EalFanlc seriei 
produces cryvtallizalion. while the positive pole couofcracla It. Ught also cauMs- 
catopbor to cryalallize from iti alcoholic saluliou, and It ii rcdinolved in a dark day. 
—Dr. Urc- 



OMzcdoyGoOgle 



14S ATTRACTION. 

water, no advantage is gained by the aid of beat, except in speed, nor 
does a reduction of temperature cause it to crystalbze. ^e only 
metbod in whicb this can be effected, is by diminishing the solvent by 
evaporation. It is found that crystallization is much facilitated by 
supplying a nucleus ; and Le Blanc, a Parisian apothecary, has even 
founded upon it a method of obtiuning large and beautiful crystals, by 
selecting the best, replacing them in the soluuon, and turning tliem 
daily, as the lower side does not increase. 

(k.) An incrtaae ofbvlk u comaumly an effect of ciystaUization, 
hitt lontetimes the hulk U diminuhed, as in the case of mercury. 
Substances which have been deposited from an aqueous soluti<ni, 
generally retain, intimately combined, a portion of water, whicfa is 
called their water of crystallization. The efficacy of freezing mix- 
tures is owing, in a considerable degree, to this water of crysuilisa- 
tion, which, by becoming fluid, absorbs caloric ; when, with the aid 
of heat, it causes the salt to become fluid, the salt is said to suder the 
aqaeons fusion. When it escapes spontaneously, into tlie atmosphere, 
the salt is said to effloresce, for the crystalline form is destroyed, and 
it falls into powder. When the salt attracts water from the air, and 
becomes more or less fluid, it is said to deliquesce.* When it splits 
and crackles by heat, it is said to decrepitate, 

(I.) All bodies, in crystallizing, assume a determinate form. Thus 
the crystal of alum is an octahedron ; thai of common salt a cube ; 
of the beryl, a hexahedral prism, &c. It must not be understood, 
however, that these forms are mvaiiable. The same substance will 
sometimes assume one form, sometimes another, according to cir- 
cumstances. But, to this apparent caprice there is a limit, for a 
given substance will always crystaUize in one of a given number of 
forms, which are appropriate to it. 

PriiJiu and pyramids are anumg the most comTTum forms of crys- 
tals, bui they admit of great diversity. 

(m.) All tlte forms of crystals are rediidble cither by dissection or 
by c(Uciilation, to sic primitive forms, namely, the hexahedron, includ- 
ing the cube, parallelopipedon and rhomboid ; the regular octabedrcm ; 
the prism of six sides ; the regular tetrahedron ; the dodecahedron 
with rbomboidal faces, and the dodecahedron with isosceles triangu- 
lar faces. This very cuiious subject has been developed by the suc- 
cessive labors of Rom£ de L'Ide, Gahn, Bergman, Boumon, and 
Hauy. Haiiy completed what Bergman had begun, by extracting 
the primitive form of calcareous spar in tiie following manner. 



Sometimea portioDa of (be fluid bom which cryital* liave been precipluiedt are 

— ' mechanically belnecn )ho pUtes, vid It may be even a portian of a fluid con- 

dJIIercDt subiUncc, If other salt.i or conipoundg were prc»«ntin the mtullon. 



lodeed m 

laWnsai 



OMzcdoyGoOgle 



Dr. Hare, Fig. 1 to 14. 

' rC^r^ ■ ;., ■' "P — ' "As each of the adea of 

^ ' an hexagonal prism of calca- 
reous spar, IS bounded by 
two edges, one at each end of 
the prism; there are ax edges 
at each end, and in all, twelve 
edges. If to every one of 
the twelve edges a knife be 
forcibly applied, in the direc- 
tion indicated in 6gure 1, one 
of the edges, a b c, a b c, 
bounding each side, mil yield 
90 as to expose a smooth nat- 
ural facet, making an angle of 
45° with the adjoining side. The alternate edges will not split off 
so as to present surfaces corresponding either in smoothness, or obli- 
quity, with those above described, so that the six facets will be equal- 
ly divided between the two ends of the prism, each having three facets 
alternating witli three remaining edges." 

" If the dissecbon be continued, by applying die knife in directbna 
parallel to the facets, finally a rhomboid R wiS be developed, which 
exists not only in the hexagonal prism, but in many other crystalline 
forms of calcareous spar.", 

" All these other forms are called secondary. The rhomboid, 
which is their common nucleus, or primitive form, is beaudfully ex- 
emplified in tlie Iceland spar." 
Fic. 2. 



h" The same autlior teaches us that a cu- 
bic crystal of fluor spar, can be split only 
in directions parallel to the faces of an oc- 
---- , ; -, tohedral nucleus, whose situation, relatively 

. V-T/'' ' *^ ^'"^ contain mg cube, is represented by 
■, ■■' -'1 j figure 2." 

\ .,!l'1— 1 "By various dissections, analogous to 

"■;■■' ■■•,_ those which have been adduced, it is ren- 

— ■ • •• ' "• dered highly probable that every cn-stalli- 

zable substance has an appropriate form, which it assumes ui the first 
instance, and which is the basis of all its other forms." 

" The nuclei may sometimes be obtained by percussion, sometimes 
by heat ; in other cases by heal followed by refrigeration." 

" Although a nucleus cannot be extracted in every instance from 
crystals, the existence in them of primitive forms, is usually inferred 



OMzcdoyGoOgle 



by onalc^. Tlie angles which the sides make with each other, are 
always the same in a nucleus, however obtained ; and such crystals 
are always divisible in directions parallel to all their surfaces, where- 
as there are some surfaces of secondary forms, paraUel to which, by 
cleavage, new facets cannot be obtained." 

" Haiiy enumerates six primitive crystalline forms, the parallelo- 
piped, (including tlie cube, rhomboid, and four sided prism,) the reg- 
ular tetrahedron, regular octohedron, hexahedral prism, rhombic 
dodecahedron, and dodecahedron widi uiangular faces." 

Fig. 3. — Quadran- Fia. 4. — Cube. Fig. 5. — RJiomboid. 

gular or jovr- 
tided prism. 



Fig. 6. — Tetrahedron. Fig. 7. — Octohedron 




Fig. 8. — Hexangular or Fio. 9. — Bhowhic dode- 

aix sided prim. cahedron. 



DK;,lz=..,C00g[e 



ATTRACTION- 



Fio. 10. — Dodeeahedrim Fic. U. — TrinngiUar or 

mth triangitiar faces. three tided prism. 



" The primitive forma, by a further dissection of the octohedror, 
hexangular prism, and dodecahedra, in directions, not parallel to tlie 
sides, may be reduced into three forms : the tetrahedron, or simplest 
solid, the triangular prism, or the most simple prism ; and the paral- 
lelopiped, including the cube, rhomboid, and four sided prism. As 
it is in size only, that integrant atoms can be altered by cleavage ; it 
it is inferred that If the dissections were continued until the smallest 
integrant atom should be developed, its form would be the same as that 
ofthe parent mass. Henccalso the inference has arisen, that the only 
forms, which belong to integrant atoms, are those above mentioned. 

It is remarkable that {the sphere and spheroids only being except- 
ed,) these three forms are the simplest of solids. As three lines 
are the smallest number that can include a superficies, so four planes 
are the smallest number that can include a solid ; the integraot 
molecules above named have successively, four, five, and six faces. 

(n.) The actual or tecondary forms are buUt up, by the vnion of 
integrant particles, to produce the primitive form, and then by the 
addition of other partiaes, tingle or tn groups, upon the faces of the 
primiiiveform. 

(o.) The developement of these processes, corutittUes the theory of 
crystallization, proceeding according to the laws of decrement. 

1. Parallel to the edges — 2. Parallel to the diagonal-— 3. Par- 
allel to a line intennediate between the side and the diagonal ; or, 
parallel to either of the above, but proceeding by three in breadth, 
and two in height, or the reverse, or by such a ratio that the relation 
of height and breadth, in the ranges of particles, shall be expressed 
by a proper vulgar fi'action; this supposed arrangement of integrant 
particles is called — 4. Mixed decrement. 

{p.) A minute consideration of this subject, belongs to mineralogy 
but the following illustrations will render the descriptions of incre- 
ment and decrement inteUigible. 

Conversion of a cube into a dodecahedron. 

" If a cube be increased by layers of particles, applied to all its 

ades, the edges ofthe layers being parallel to those ofthe cube, and 

19 



DK;,lz=..,C00g[e 



each layer being made less than that immediately precediog it, by 
one row of particlea on each of its edges, a dodecahedron, at twelve 
sided solid, with rhombic faces, will be produced." 



"If, instead of diminishing every layer one row, on every edge, tliey 
be made less, at each addition, by two rows on two pajallel edges, 
while, upon the other two edges, each layer is made alternately the same 
as the preceding, alternately less by one row, a dodecahedron, ot 
twelve sided sohd, with pentagonal or five sided faces, will be pro- 
duced." 

Fig. 13. 



OMzcdoyGoOglC 



ATTRACTION. 



I4T 



"One surface (C) of the cube, in each figure, is represented as if 
no addition were made to it, in order that the situalioD of the nucleus, 
relatively to the pyramids raised upon it, may be understood. It 
must be evident that each rhombus, R R R R, in fig. 13, and penta- 
goD, PPPPP, in6g. 13, is made upof die surfaces of twoadjcMn^ 
ing pyramids, built upou a cubic nucleus." 

" The decrements may proceed only on two sides, or a diminution 
o( two, three, or more rows may take place on all the sides ; yet in 
either case, secondary crystallme forms may be buik upon the c(»n- 
roon nucleus, or primitive form." 

Fio. 14.— Of the Goniometer, or inttrvment for meatttring the ati- 
ght of crystalt. 




"The goniometer is founded upon the 15th propoaition of £uc]id, 
trfaicb demonstrates that the opposte angles, made by any two lines 
in crossing each other, are equal. Hence it follows that the angles 
made by the legs BB, BCB, of this instrument, fig. 14, above and 
below Die pivot an which they revolve, are equal to each other.—* 
Consequently, if they be made to close upon any solid crystalline 
tmgle, presented to them at C, they will comprise a, similar an^e on 
ibia other side of the centre about which they turn. This angle is 
evidendy equivalent to that of the crystal, and is ascertained l^ in- 
specting the semicircle A, graduated into 180 degrees precisely in the 
same manner as a protractor." 

"TTie construction of goniometers is usually such aa to allow the 
legs to be detached from the arch, in order to facilitate their ajnili- 
catioa to crystalline angles ; and yet, so that they may be reapplied 
to the semicircle, without deranging them from uw angle to which 
they may have been adjusted." 



DMz.d.,Goog[e 



"The piece of farass, in which the pivot is fastened, slides in s sGt 
in each leg, so as to permit tbem to be made of the moat suitable 
lengtfi, on the wde on which the costal is applied." 

jV reflective Goniometer of Dr. Wollasion, depends upon the 
reflection of the rays of light from the brilliant surfaces of coniigu* 
ous crystalline plates, uncovered by cleavage, or of naturvl surfaces. 
The pieces or crystals to be examined are fixed upon an axis whose 
revrJution carries around a graduated wheel, which measures the an- 
gle contained between two ccHitiguous surfaces, when they have ar- 
rived successively in the position to reflect an image of the bar of a 
window or of some other definite line.* This instrument is much 
more accurate than that of Carangeau, used by Haiiy, (See the fig- 
ure above,) and has corrected a number of errors, some of which 
were important. 

Mr. Daniell has contrived a method of discovering the structure of 
crystals by solution. In a mass of alum lying in water, there will be 
discovered, after some time, upon its lower part in high relief, both 
octahedral forms and sections of octahedra. — Borax gives umilar 
results. Even shapeless metals, which a peculiar tendency to crys- 
tallization, will reveal tlieir crystalline forms by the action of acid sol- 
vents; bismuth exhibiting with dilute nitric acid, cubes, antinKHiy, 
rhomboidal plates, and nickel, regular letrabcdra.f 

Very different views of crystnJUzatian are taken by mwe recent 
authors, among whom Mr. BrookeJ and Professor Mohs^ are the 
most disunguished. Crystalline forms that have an intimate connex- 
ion with each otlier, are considered as forming certain natural groups 
or systems of crjstallization. Tliey are called, the tessular system 
which comprehends the cube, the tetrahedron, the regular octahe- 
dron, die rhombic dodecahcdi'on, &c. ; tlie pyramidical system, cott- 
taining the octalicdron with a square base and the right square prism ; 
tlie prismatic system including the rectangular and rhombic octahe- 
dron, and the tight rectangular and right rhombic prisms ; the hemi- 
prismatic system, embracing the right rhomboidal and the obUque 
rhombic prisms ; the tetarto-prismatic qfstem contaming the oblique 
rhomboidal prism, and the rhombohedral system cmnprehending the 
rbombohedron and the regular hexagonal [»ism.{| 

This complex system seems to present do advantage to compen- 
sate for the absence of the sinqilicity and perspicuity wluch charac- 
terizes the system of Haiiy. 



* Ainoro pirlicular ducriplitm with a plats mtj be IbnDd in Phillipa' MliMrtlogy. 

I EngliHl, Jour. Sd. Vol. I. p. 24. 

{ Familiar Inli«duelIon to CiTst«ilo|t™phy. 

STreatlw no Mineralogy, translated by Mr. IlnidinEer. 
TurDer,id£d. p.5»». 



OMzcdoyGoOgle 



It is worthy of observation, that Professor Milscherhch of Berlio, 
■n 1819,* discovered " that certain substances are capable of being 
substituted for each other in combination, without influencing the 
form of the c<Hnpound. The neutral phosphate and biphosphate of 
soda, have exactly the same form as the arseniate and binarseniate of 
soda ; the phosphate and biphosphate of amuKuiia with the arseniate 
and binarseniate of ammonia, the biphosphate and bbarseniate of 
potash ; each arseniate has a corresponding phosphate, possessed of 
the same Ibrm and containing the same number of equivalents of 
acid, alkali and water, and didering in nothing but in one a containing 
arsenic, and the other phosphoric acid." 

It appears then that certain substances, when combined in the same 
manner with the same body, are disposed to assume the same crys- 
talline form, and this discovery has given origin to the phrase 
isomorfriwus crystals. The arseniates are isomorpbous wiUi the 
phosphates; the oxide of lead and baryta and strontia form iso- 
morpbous Kills with the same acid. The isomorpbous crystals ap- 
pear to ctwtain the same quantity of waterf of crystallization, and 
there are many other very curious circumstances in the consdtutitHi 
of these bodies, which are too minute to be introduced into this work, 
but which are thousht to give great support to the atomic theory to 
be mentioned bereaJier. 



r DR. WOIiLAGTON. 



It bas been already remarked, that among soUds bounded by plane 
faces, the tetrahedron, the triangular prism, and the cube, are the 
nmj^test ; these are the three mtegrant molecules of Haijy, and it 
would seem that th^ amplicity and their capability of being so ar- 
ranged as to produce, perhaps, all other soUds, affiiraed a strong pre- 
sumptioo in favor of their bebg the real integrant particles of booies. 
But a diffirent view bas been uken of this subject by Dr. WoUaston ; 
for this reason among others, that in " crystallograpy we meet with 
appearances which Haiiy's theory but imperfectly expkhis. A slice 
of fluor spar, for mslance, obtained by making two successive and 
parallel sections, may be divided into acute rhomboids ; but these 
are not the primitive forms of (he spar, because by the removal of a 
tetrahedron from each extremity of the rhomboid, an octohedron is 
obtamed. Thus, as the whole mass of fluor may be dinded mto te- 
trahedra and octobedia, it becomes a questicm which of these forms 



• Add. de Cbimia and de Pbyitqne, Vol. XIT, p. 172, XIX, p. 850, ■»! XXIV, 
pp. 364 andsra, Tarner. 

t And when ths quiDtlty of water li dUIereat, the ciyHalt asmme a difibrenl 
Ana.— ZWiMr. 



OMzcdoyGoOglc 



is to be called priniitive, especially as neitfaer of 
tbem can fill space without leavmg vacuities, 
nor can they produce any ammzeraeat suffi- 
ciently stable to fonn the basis of a permanent 
crystal." 

" To obviate this incongnii^, Dr. WollasUm 
(Phil. Traiu. 1813,) hag very ingeniously pro- 
posed to consider die prinutive particles as 
spheres, which, by mutual attractioD, have as- 
sumed that arrangement which brings them as 
near as possible to each other. When a num- 
ber of similar balls are pressed together, in the same plain, they form 
equilateral triangles, with each other ; and 
if balls so placed were cemented togetfaw, 
. and afterwards broken asunder, the straight 
^ lines in which they would be disposed to 
separate, would form angles of 60° with 
each other. A single ball placed any where on this stratum, would 
touch three of the lower balls, and the planes touching their surfaces 
would then include a regular tetrahedron. A sqaare of 
four balls, with a single ball resting upon the centre of 
i each surface, would form an octohedron ; and upon ap- 
plying two other balls at opposite sides of this octi^e- 
dron, the group will represent the acute rhomboid. 
Thus the difficulty of the primitive form of fiuor, above alluded to, is 
done away, by assuming a sphere as the ultimate molecula. By ob- 
late and oblong spheroids, otner forms may be obtained."* 



♦ 




Dr. Wollaston has demoosuated, geometrically, that by assortiag 
spheres and spheroids in particular groups and modes, all the soUds 
of crystals may bo constructed. The cannon balls in an arsenal, are 
often arranged in such a manner as to illustrate this subject. Chie 
group forms a square and another a triangle, and by piling them 



' Bnnile, quoted by Hare 



OMzcdoyGoOgle 



ATTRACTION. 161 

they becom« pynmids, shewing half a tetrahedron, half an octohe- 
dnm, &c. which would be completed, hy continuing the group down>- 
ward, m the same form. The marbles used for play, 1^ children, 
may be made use of for Hmilar illustratioas. But it is (Xivious ihai 
the truth of this view, beautiful and probable as it is, cannot be de- 
monstrated, DOT ia it perhaps inconsistent with that of Haijy ; for if 
the ultimate integrant particles of bodies are spheres or spheroids ; as 
they may, by the supposition, be grouped so as to produce Haiiy's in- 
tegrant molecules, and these may be the last term of mechanical 
analysis, although the ultimate particles of which they are composed, 
may be spheres ; and when they are inconceivably small, there will 
be no appreciable difference between the plane and curved faces. 
Indeed, in Haijy's theory, the passage by increment and decrement, 
is supposed to be by panicles so minute, tliat the steps cannot be ot- 
dinaiify perceived, although the imperfection of the process some- 
times renders them more or less obvious.* 

5. Chemicu. attkaction or affimtt. 

(a.) It ii exdutivdv, a corptucuiar power. 

(b.) lu three prittapid charaeterulia, are : it is exerted at insen- 
^le distances ; between particles (Hily ; and those particles are al- 
ways heterogeneous. 

(e.) lU t^wU are, a change of propertiet more or leu complete : 
it is unlike cohesiiHi, which mduces no change of properties, but 
merely of bulk or form. 

{d.} The change of propertiet, in the caiei vihere weak affinities 
are erertetf, it often ili^ ; giviw in wumy instances oniy the mod- 
ified propertiet of the parent tvMancet ; as examples, we can men- 
tion watery soIuikmis generally, as of salts, gum and sugar, and often 
alcohoUc solutitHis, as of resins ; and among fluids, alcohol and water, 
and water and acids ; the union in such cases, is quiet, and attend- 
ed with IK) remarkable appearances. 

Je.) But the union is permanent and eatmot he dtttroyedhy meehan- 
meani. Solutions of salts, sugar, gum, and alcbbol, in water, are 
instances to point ; they are not decomposed by repose, by agitation 
or by filtration, thus proving that the union is not merely mechanical. 

{J.) This dots of compounds should he eontidered as midway be- 
tween mere aggregation and energetic chemical combination ; — The 
union is chemical, inasmuch as it is not subverted by mechanical 
means ; but these ccmipounds partake of the nature of aggregates, in- 
asmuch as they present (he mitigated prc^rties of the parent sub- 
stance and no new properties. 



a nibjecl which is par~ 



oMzcdoy Google 



152 ATTHACTiON. 

(g.) Jilere mechaftKol mixtures are s^araied by meehtmicalmeaiuf 
muady water becomes clear by filtraticxi and by repose, which have 
no eSect upon salt water. 

(h.) Energetic chemitxd action prodttcet an entire change of prop- 
erttes. Oxygen and hydrogen have no resemblance to water or to 
each other ; nitric acid and potassa none to salt petre ; muriatic acid 
and soda none to common salt ; potasuum and oxygen none to po- 
tassa and so on, in a thousand cases more. Inert substances pro- 
duce active compounds, as in sulphuric acid; active principles inert 
compounds as in sulphate of potasss ; compounds containing an en- 
ei^eiic principle or principles, retain a degree of activi^, sometimes 
great, as nitrate of nlver and many other metallic salts, and arseniate 
of potassa ; inert principles produce inert compounds, as in borate of 
. magnesia, and in a word, there is great variety in the results, so that 
they cannot be predicted, and can be learned from experiment only. 

(t.) Colors are produced, and diSerent colors by dinerent propor- 
tions of the same materials. The metallic oxides and salts, red lead, 
oxide of mercury, the cbromates of lead, natural and artificial, and 
the two Eulphurets of mercury and of arsenic, are examples. 

J J.) Colart are destroyed. — Chlorine destroys nearly all colors, 
the sulphurous acid many. 

(ft.) The tpecific gravity is changed, and generaUy increased. — 
Compounds of ammonia and the acid gases are precipitated in the 
form of soUd salts ; but some of the metallic alloys are lighter than 
the mean specific gravity of the metals combined ;* and some gaseous 
combinations form other gaseous compounds that are lighter, but in 
general aeriform bodies by combining, undergo condensation. f 

(I.) Temperature, or senses heat, is changed. — It is increased, as 
when alcohol and water, sulphuric acid and water, oxygen and com-, 
bustibles, sulphur and metals, iodme and phosphorus, are imited. 

It is diminished, as by solution and by all freezing mixtures. 

(bi.) The form of bodies is changed. 

Solids become' fluid, as in the freezbg mixtures ; also Glauber's 
salts and nitrate of ammonia rubbed together. — Webster. 

Fluids become solid, as water in slaked lime, and in nearly all 
crystals. 

Solution of strong muriate of lime, decomposed by strong sulphu- 
ric acid is precipitated solid ; most acids by combining with difierent 
bases produce solids, provided water is removed by evaporation. 

Gases become lupad. — Oxygen and hydrogen form water. 



* The cotulitueat particlss miyhave ipDroiinitted tad (ho iolegraot puticles 
receded, m> that the net Involfes no impoisiMlitjr. 

( Id atefiant ^a, the elements In ■ itale of freedom wooM occupy bur volumek 
imtetd of one. 



OMzcdoyGoOgle 



ATTE&CnON. 153 

Gtutt bteone foJwI. — ^Acid gases and ammooia precipiute aolid 
salts, (vide k.) 

Sol\da beame ^a«.— Serera) anunoniacal salts, properly decom- 
posed, are converted iato aeriibnn bodies ; this is true, particularly of 
the nitrate and muriate of aniniQnia. 

Fluidt become j-tu.-— Water decomposed by galvanism with gold 
or platina wires tiffi>rds oxvgen and hydrogen gases in mixture.* 

(n.) ^ eery minute divuton of moMer u efictid by dtoMcal union. 
It is much more minute than any mechanical means can produce ; ni- 
trate of silver discovers the sUghtest trace of muriatic acid : so am- 
OMoia detects any salt of copper ; bydriodic acid platinum j recent 
muriate of tin and green sulphate of iron discover gold. 

(o.) Cohetion retitU cAemtcoJ action. — ^Tberefore as a prelim- 
inary it is diminished, by the mechanical operations of pounding, 
rasfHog, grinding, &ic. and by prenous chemical operations, as when 
caustic potash is fused with refi-acUMy gem« and stones, to prepare 
^em for solution in acids. Marble in lumps, dissolves slowly in acids, 
but in powder rapidly, — so of salt, sugar, &c. 

(p.) AJinityu not univenai. — ^Water does not dissolve siliceous 
mid, nor resins, nor oil, nor clay ; these bodies may he mixed with 
water by mechanical agitaticsi, but they will separate again by repose, 
or by filtration or other mechanical means. 

(q.) Ab body, eletaeatary or compound, it tnthout affinitia. — Sili- 
ceous sand unaffected by water, is dissolved by caustic potash; resin 
by alcohol, oil by alkali, conmion clay, in part, pure argil entirely, by 
sulphuric acid. 

(r.) Solulion it only a parliciUar eaie or mode of chemical action 
and tmum. — It takes place geoerally, between solids and fluids ; but 
is also predicable of the other forms of matter ; gases dissolve soUds 
and fluids, and these in turn absorb gases. 

(f.) Solution it generally promoted by heal. — ^In the cold, 4oz. 
of water do not dissolve 3oz. of sulphate of soda, but heat enables 
the whole to be readily dissolved. — Henry. 

(t.) The solvbiUty of diMrent tubttancet, in the tame fiiUd, it very 
d^ermt^—iot. sulphate (rf ammonia, ^z. sulphate of soda, t'jdz. 
ofsulphate of potash, and jj, of sulphate of lime, are dissolved in 
loB. distilled water. — Id. 

iu.) Heat generally proutotetehemiad action; as is comm(»i}y said, 
in most cases truly, by diminishing the power of cohesion, as is 
seen in the solutions of solids; butthisexplanation would hardly apply 
to the explodon of gunpowder, and of fulminating powders. Some- 
times cold brings on chemical action ; sea water, containing muriate 

* Many irtipDrtaiit chemical events depend on conclensitjan or evolutioD oTguei; 
•spliMNBS are often produced by the latter. 



DK;,lz=..,C00g[e 



154 ATTUACTION. 

of Boda, and sulphate of magne^ is said to unde^ double decom- 
positkm, at the freezing temperature, jvoducing sulphate of soda, and 
muriate of magnesia.* It cannot be doubted, that electric and gal- 
vanic agencies are frequendj developed by heat, and that thus chem- 
ical action is often induced. 

(ff.) A modified degree of heat it necettary. — Red precipitate is 
formed at or near the boiling heat of mercury, but it is decomposed by 
ignition, and both its oxygen and metal are recovered. 

(ur.) Ckemiajl action u ofien brought on by mechanical mamt. — 
Several of the fubninating powders, and the mixtures of the chlo- 
nte of potash and combustibles, explode by a blow, by friction, and 
pressure ; which favor, at once, the approximation of the particles 
within the sphere of attraction, and the developement of heat which 
favors the chemical action. 

(x.) Ab approximation, short of imperceptible ditimue, viiU bring 
«n ehemieal action, — ^The negative is established by the approxima- 
doa of any kmd of matter towards any other for which it has an 
affini^ ; as for instance, a drop of oilric acid on a glass plate, wiH be 
indifierent to silver or copper filings pushed near to it, but the action 
commences when apparent contact is established. When sulphur 
and mercury are in apparent contact, there is no action, but it is 
brought on W rubbing them tt^ether. Sulphuric acid will run to 
the bottom ol*^ alcohol, and produce action only at the touching sur- 
faces, but it is quickly brought on, in the entire mass, by agitatioo. 
Agitatitm of fluids and solids, to make them mingle quicldy, pro- 
motes their action, as in the case of common salt and water. 

(y.) Even apparent amtaet u ofien injii^etent, and tolution be- 
eomet necMiory. Hence, the old maxim, " corpora non agunt nisi 
aint soluta." Tartaric acid and carbonate of soda, dry quickUme and 
dry muriate of ammonia, dry nitrate of copper, wrapped in tinfoil — 
ip each of these cases there is no action till moisture is supplied, 
when it comes on vigorously. 

(2.) Bo£eihavingnoqffmityare»ometime*brotighttounitebyaih«-d 
body. — Oil and water, by the intermedium of caustic alkali, form soap. 

(AA.) The force or aftinitt is diffbbxkt between dif- 
ferent BODIES. 

Were it otherwise, there would be no decompositions, except by 
the eSect of the imponderable agents. 

(BB.) Elective affinitt is the FiamuTrvE exfresbion of 

THE PREFERENCE WHICH ONE BODY 13 SUPPOSED TO IUNIFE8T 
FOB ANOTHER, TO THE EXCLUSION OF A THIRD. 

The alcoholic solution of camphor is precipitated by water, which 
miites with the alcohol, and the camphor may be redissolved by the 
addition of more alcohol. 

• AiUn'* DicL VoL II. pp. 389, ud 179. 



OMzcdoyGoOgle 



The acetate of lead is decomposed by sulphuric acid ; the nitrate 
of dver, by copper ; nitrate of copper, oy iron ; nitrate of mercury, 
by copper ; munate of soda, by sulphuric acid ; and so in instances 
innumerable. In all these cases, except the first, there is a new 
salt fiHTned by the addition of the decomposing body, the add or 
base of the preceding salt being liberated. 

(CC.) In rack etuet, Iker^ore, a compovnd of two prinapla is de- 
coapoiea by a third, which vnitu with one, and exavdea tie other, 
which may be thus illustrated; A+B=C. D unites with A, and 
forms the compound A+D, or with B, and forms the compound 
D4:B, B in the first case, and A in the second, being excluded. 
If any solid appears, it is called the precipitate, and the decomposmg 
body, the precipitant ; the fluid is called the solution. 

{dd.) In tome catet, a weaker affinity u compemaied by an itl- 
craaed quantity of the feebler ingredtent. — Muriate of soda 2, 
oxide oflead 1, there b no effect in twenty four hours ; but with 
muriate of soda 1, and oxide of lead 3 or 4, decompositiw follows in 
twenty foux hours, and muriate of lead is formed, and soda, or its sub- 
cartmate, evolved ; this fact Is the foundatiDD of the manufacture of 
soda from common salu The solution of sulphate of coj^ier b blue, 
but if the muriatic acid b added largely, the color changes to green, 
indicating a decomposition, and the production of a muriate of cop- 
per. 

(EE.) DOITBLE XLECTirE AFrDTITT, IS WHEBE TWO C0VP0UHO8, 
EACH CONSISTIKO OT TWO INOBBDIEHTS, ASX DECOMPOSED, rOBM- 

mo TWO REw COMPOUNDS. — ^A, composed of B+C, b mixed with 
t>, composed of E+F; the result may be, B+E, or B+F, or 
C-|-£, or C+F. Important decompositions, otherwise unattaina- 
ble, are often effected in this manner. 

(FT.) Decomtositions stiix mohe complex, intoltino the 

ACTION OP BETEKAI. AOEKTS, EACH CONSITlNa OV TWO OB MOBS 
PRINCIPLZB, MAT PRODDCB SCTBBAL DECOMPOSITIONS, AND SETE- 

BAL NEW COMPOUND s.^Many of the processes in the animal and 
r^etable economy, are of tfab description, and some among minerals. 
(GG.) Extraneout draanttaneet andforcet influenee chemaU ax^ 
<um^ among which the cluef are fpuxKtky, eahaion, imoivbiiity, gnm- 
iUf, dattietty, tffioreMceitce, temperature, mechanical prature, and 

1. Quantity of matter exerts an important mfluraice on ciiemical 
decomposioons. Thb is a well known practical fact. In dissolv- 
ing a salt in water, the first portions added, are more readihr dissolv- 
ed than subsequent ones, and the energy of attraction* dimmishes as 
we approach the point of saturaticH). 

• Or b it nwekmtcai ofrtlruettMt that reUrdi Iho solution ; the lUgrtt of affinltr 
mnainiiiK the wme l—lCvmmtmitmttil.) 



OMzcdoyGoOgle 



156 ATTRACTION. 

So, in decomposiDg ccHnpound bodies, either by affini^, or heat, 
the laat portions are someUraes separated with much greater diOi- 
euhy than the first ; thus the black oxide of manganese easily ^rec 
up one proportion of oxygen by a red heat, but no de^ee of lieat 
can expel the whole. In the same manner, the laat portions of car- 
bonic acid are expelled from carbonate of lime, with great difficulty 
—the first with ease. 

To efiect complete decompositions, also, it is sometimes necessa- 
ry to employ large quantities of the decomposing substances, aa in 
ptecipitaUng a metalhc oxide from its union with an acid, and in de- 
Gomponng various salts by acids, as the nitrate of potash by snlphi^ 
ric acid. 

Partial decompositions are produced also by tbe exertion of a 
weaker aflhuty, if it is aided by a la»er quantin of matter, as in the 
case of muriate of soda and oxide oi lead. From these, and other 
nmiler facts, the distinguished chemist Berthollet drew the conckn 
■ioD " that affinity is modified by quanti^ of matter, or that the 
ebenucal ac6on of a body is exerted in the ratio of its affinity and 
quantity of matter, and he endeavored to estabfisfa it as a Law, apply- 
ing to all cases of chemical combination." — (Murray.) He sup- 
p<»ed also that " when two substances are in competition to com- 
Dine with a third, each of them obtains a degree of saturation pco- 
portionate to its affini^ multiplied hy its quantity ; a product which 
he denominateB mau.— (I7re.) 

Berthollet supposed that the tables of affini^ expressed mere^ 
the actual order of decomposifion, as influenced, not only by affinity, 
but t^ quantity of matter, and many other circumstances, and that 
there was do such thing as a settled force of affintQ', between difer- 
ent substances. Berthollet contended also, that in propcwtioa as it 
tequires more of a particular base to saturate a given add, tbe less 
is the affinity between that acid and the base. 

But we will not occupy time with views, which howevec insenioas 
and abfy supported, appear not to be universally tenable. Uany of 
the facts adduced in support of than, can be explained in omer 
ways, uid the well establiE^d doctrine of de&nite proportions could 
not be true, were there so exact force of affint^, udepeodeitt o£ 
tfuantity of matter. Still, (juantity of matter does undoubtedly ope- 
rate in many cases, to a certain extent, and " although incompetent 
lo co^mteract direct and strong affinities, or to afiect ^ combmatitMi 
of bodies which are disposed to unite in definite proportions, its in* 
Alienee may be cleady traced in a number of instances, wher* k 
modifies weaker attractions, and perhaps decides the resuh, whea 
<^posite affinities ate nearly balanced."* — {Murrai/.) 



OMzcdoyGoOgle 



ATTRACTIpN. ]5f 

3. Coketum. — It has been already stated that this power is tbe im- 
mediate antagonist of chemical action, which rarely taKesplace till ills 
overcome. Hence the great advantage of solution and tusion, which 
are the most common means of inducing chemical action. In a few 
cases, the energy of attraction is so great as to overcome the cohe- 
sion of two solids, and cause them to unite, and to become fluid io 
the act of combiniog. Muriate of lime and snow, and caustic fixed 
alkalies and snow are examples. Even fluids may have their ener* 
gy exalted by increased temperature, as is the case with nitric acid and 
alcohol or o^s, and with sulphuric add and water :* if these fluids are 
hot it is scarcely safe to mingle them in any con^derable quantity. 
Heat always promotes chemical combination, when cobenon is an 
obstacle, and often, it is sufficient that one of the substances shcHild 
be fluid. Mechanical division favors chemical action, principally by 
increasing the surface. Cohesion resulting from chemical action 
often modifies the results of experiments. A mixture of sulphurio 
and muriatic acids, with a solution of baryta, will resuh in the forra- 
atioD of sulphate of barytes ; in part, no aoubt, on account of its in- 
scJubility, but the efiect must depend also upon a superior affinity. 

3. ImolvbHity, — ^This depends upon cohesion, and has reference 
to the solvent power of the hquid in which the c<die^e power is ex- 
erted. It removes the body, newly formed from the sphere of actioDt 
and thus leaves the remaining principles free to act upon each other. 

4. Qravity. — So far as there is a great diSerence in tbe graialy 
of bodies that are mixed, it goes to retard chemical action. Thus, 
sah at the bottom of water dissolves much more slowly and unequal- 
ly than if it is a^tated ; and if allowed to remain quiet, die soIutiCHi 
will be most dense at bottom, and the least so at top. If metals of 
widely different specific gravity are melted together to form an alloy, 
a largCT proportioD of the heaviest metal will be found at the bottom, 
and agitation is necessary, in order to bring the particles into prox- 
imi^, so that the union may be eflected. 

5. Elasticity. — ^This power, mder diferent cireumBtances, both op- 
poses and favors chemical action. In general, gases are not [wone to 
combine, because thrir ponderable particles are too far reinoived Sum 
each other by the caloric, with which they are urated. Thus oxygen 
and hydrogen gases may be retained in mixture, vritbout combininr ; 
611 flame causes them to unite explosively. Ammonia and the acid 
gases unite readily, and even {H«cipitate solid matter, and one gu 

* Dr. Turner reinarki, (Chem. 2d Ed. p. 1ST,) that " fluids commonl; act upon 
each other as energetlcatly at low temperature*, or at a tcmperatare Juit urOleMiit 
to caofe perfect liquefactloa, aa when thdr cohesive power i> still fulher dlmlnMieJ 
b]r caloric." The bmiliar iutancea meutknied In the text ^low Aat tbli remaA 



OMzcdoyGoOgle 



in the nascent state, will iintte with another already in the elastic 
form ; thus hydrogen unites with nitrogen, to form ammonia, and 
both these gases, evolved from pulrefacticm, combine in their nascent 
state, and form die same body. 

Mechanical force favors the combination of gases with each other, 
and with fluids ; oxygen and hydrogen can be made to combine by sud- 
den and violent pressure ;* and pressure, cold and agitation are the usual 
means of impregnating fluids with gases, as in the case of soda water. 

Elasticity favors decomposition. When one constituent of .a body 
b pToae to assume the terial state, in general that body is more easily 
decomposed, both by heat and by affini^, than if both ingredients were 
fixed. This is the case with the carbonates, and with water contain- 
ed in crystals, and other combinatioDs ; and even potassium is driven oflf 
by its superior voladhty, at an intense heat, when the alkali contain- 
ing it is brought into contact with highly ignited iron. Many instan- 
ces in illustration of these views will occur as we proceed. 

6. Effioretcence. — ^This is a circumstance of no great importance, 
but it sometimes favors chemical action, by withdrawing a salt that has 
been formed, fit>m the field of acdon, and in this manner leaving the 
lemaining ingredients free to act again. Thus in the countiT around 
the natron lakes m Egypt, muriate of soda and carbonate of Ume mu- 
tually decompose e&cD other, and the carbonate of soda crawls up in 
crystals upon the grass and other bodies accidentally present. A 
similar e^ct I have often observed upon common plaster, made 
with sea sand containbg muriate of soda, which undergoes decompo- 
sition, with the carbonate of lime, and forms by efflorescence a plu- 
rerulent carbonate of soda appearing like a fine snow upon the walls. 

7. Temperature. — The rektion of bodies to heat is of the utmost 
importance with respect to chemical acdon ; but the principal facts 
have been aheady adverted to, under other heads, and will be con- 
stantly illustrated m our whole progress through the science of chem- 
istry. In genera], however, it may be said that there are few chemi- 
cal events which are not either brought on by change of tempera- 
ture, or which do not induce a change in that pardcular. 

8. Preutire, is an important auxiliary to chemical acdon. It often 
determines its ccmimencement, as in the fulminating powders, and the 
mixtures of the chlorate of potassa with combustibles. It appears to 
operate both by caudng approximation of pardcles, and by inducing 
augmentation of temperature. Its agency on elasdc fluids in relation 
to each other, and in relation to them and gross fluids, and even to 
solids, is not less important. But most of the leading facts have 
been mentitxied already, or will be mentioned hereafter. 



of the beat evolved. 



OMzcdoyGoOgle 



ATTRACTION. |{9 

9. Qaieanv; EUetrieiiy, is one of the most important of these 
causes. Its general powers have been already sketched, and it will 
be more fully developed in the sequel. 

(HH.) LimTATioNs or combination. 

1. Unlimited o7t both tidea. — ^Water and alcohol, and water and 
the strong acids are examples ; the smallest quantity of the one may 
be combined with the largest of the other, and the reverse ; a drop 
of water with an ocean of alcohol ; a drop of alcohol with an ocean 
of water. 

3. iMiited on one tide. — ^tn the case of water and saline sub- 
stances, the smallest portion of salt may combine with the largest 
quantity of water, but if we continue to add the salt, the water be- 
times saturated, and any additional quanti^ will remain on the bot- 
tom undissolved. Alcohol with camphor and resins, is governed by 
a smilar law. 

3. tamiied on both tidei to <»6 proportion. Hydrogen gas 3 vol- 
umes, and nitrogen gas 1, unite to form ammonia, CUorine gas and 
hydrogen gas, in equal volumes, form muriatic acid. 

4. lAmiied to one of Mevertd proportiom. — ^Nitrogen and oxygen 
unite in the several proportions to form nitrous oxide, nitric oxide, 
and the nitrous and nitric acids. 

Hydrogen 2 volumes -|- oxygen I, fcaro water. 

Hydrogen 2 " " 2, form deutoxide of t^drc^en. 

(I I.) The pkopohtions in which bodies cohbine are aov- 

EBKED 8T FIXED LAWS. 

Before proceeding to illustrate this proposition, we must observe, 
that there is a vast variety in difierent cases, id the force of chemical 
attraction. Sulphate of barytes is hardly decomposed by any single 
agent, and other bodies of whose compound character we cannot 
doub^ as £uoric acid, have not been decomposed at aB ; because 
the force of affinity is so strong between their principles, that nothing 
has been able hitherto to overcome it, But in other cases, the affin- 
ity is so slight that it is subverted by small variations of temperature, 
or by very feeble attractions ; as when alcohol is separated from wa- 
ter by distillation, or salts ciystallized by the simple cooling of their 
saturated solutions ; so, alcohol holdmg camphor m solution, raves it 
up readily when water is introduced, which attracts the alcohtu. 

{kk.) Properiiet of timple tolutiom, and of other feebU combtna- 
timu. — The properties are, not at all, or but little changed, and often 
ID DO Other way, than to produce modified qualities, depending on 
those of the parent substances, and on their proportions. Solutions of 
gum, sugar, salts, and acids in water ; and of resins, essentia] oils and 
camphor in alcohol are familiar examples. Such cases resemble 
mixtures, in as much as there is iitde or no change in the properties 
of the principles ; and we readily perceive, either by out senses or by 



OMzcdoyGoOgle 



IfiO ATTRACTION. 

the ^ifri&catkm of etsy tests, the predonunance of the one or of tbe 
other, or their equally. Od the wter band, they resemble chemical 
combinations, because the principles cannot be separated by naj me- 
chanical means ; neither repose, agitation or filtration, has any eSect; 
and decompositiw, when one ingredient is sensibly more volatile than 
die other, is efllected by evaporation or distillauoQ, or in other cases, 
by the interveotioo of an a&iity ; or by cold. 

(U.) TKu clou of compounds appean to be intermediate beheem a 
medanical and cAemieal condition. — We seem to need a divisioa of 
this kmd ; it would free us from embarrassment, with respect to tbe 
universality of definite proportions, and it is more reaaonable to admit 
such a divinon than to suppose the existence of innumerable mix- 
tures of di&rent combinations, in definite jvoportions, of such tlungs 
as sugar and water, alcohol end water, tuc. 

As no single word expresses their peculiarities, and for want of s 
better designation, they may be callea chemico-mechanical, or me- 
chanico-chemical compounds. 

There is greet variety among chemical compounds, in the degree 
in wbich their properties are changed and new properties produced. 
Thus, it is observed, that although there is m general no resemblance 
between water and its constituent principles, oxygen and hydrogen, it 
retains the high refractive power which u characteristic of hydrogen ; 
and again the ammooiacal salts formed between ammonia and the 
acid gases, retab a great volatility, although in other respects widely 
different from their principles ; the muriate and the carbonate of am- 
monia are striking examples. There is however no difficulty in as- 
signing such compounds to the class that is strictly chemical, and 
ihe^ would certainly not belong to that which is chemlco-mechanicaL 
This last dividon is very distinctly separated from mere mechanical 
mixtures; siUcious sand and lead shot, marble powder and powder 
of clay, among solids } and oil and water, and water and mercury, 
among fluids, would never be confounded with the class of chemi- 
co-mecbanical compounds, which we would separate from those that 
are truly chemical. Nor is there any difficult with respect to cases 
of mere superficial adhe^on, as between tallow and iron filings, at- 
mospheric dust and oils, pollen and varnishes and paints, he. The 
imlon is mechanical, and is to be referred clearly to cohesion or ag- 
gregation. 

Admittbg the distinction that has now been attempted to be estab- 
lished, there can be no he^tation in adopting the doctrine of 

DEFIKITE PBOFOBTIONS. 

(MM.) In all energstic coiibii«ations, the fropobtions or 

THE CONSTITUENT FBINCIPLES, WHBTHER THET ABE SIHFLE OB 
COMPOUND, ARE DEFINITE. 



OMzcdoyGoOgle 



. (m.) IniUaitet of definite eoapovnSa an tiBMHwraM!.-— Thiu, 
su]]Aate of baryta, whether farmed by art, at ezisdi^ ka ages, as a 
nanind producnoo, is composad of buyta 40 parts, and su^ilumc acid 
78 ; and tbey cannot be made to combme in any other proportion ; 
if the acid and a sohitiivt of the earth are mingled in any diffirent 
proportioDs, the ingredient that b in excess vill be left untooched. 

Baryta itself is composed of the metal barium 70, and cnygsn 6a) 
78, and suhbiinc acid of sulpbir 16, and oxygen 24si40. I'Ktrate 
of potassa (saltpetre) b composed of nitric acid 54, and potaasa 48n 
lOS, and nitric acid is composed of nitrogen 14, and az]^a40>xM, 
and potassa of potasnum 40, and o^^eo 8se48. 

(oo.) The iMtiimM^ power of tMbodiacaabe exprtiMdhvviia^- 
ften.*— This remarkable fact can be rendwed intelligihiB by die fbl- 
loaring instance. Li the composition of water, (he oxygen ahn^ 
sustains to the faydrc^en the proportion of 8, by weight, tM hydrogm 
being 1, and when they are in the gaseous state, tbose propoitioDs 
wiUbe found to corre^ndtoS volumes ofhydr^en aua I of oxy- 
gen; their specific gravities being in the proportioD of 1 hydrogen to 
16 oxygen, it of course requires a double vohuna of hydrogen to sos- 
tain the propmion by wei^t of 1 to 8. 

(jpp-) hi order that nmtbert may expren correctly tie eonAming 
power ofhoHtM, they tiuut refer to a common unit.— Oxygen and hyw 
drogea are the bodies which have bees selected for this purpose : di^ 
ferent philosophers have adopted, some the one and some the odier; 
but there is in my view a decided advantage in adopting hydrt^en, 
and in expressmg its lowest combining proportion hy 1 . We this 
avoid fractional expressions, for it would appear from the researches 
of Prout and others, that the cujmbining powers of all bodies mar be 
expressed by numbers which are multiples or reduplications of that 
which expresses the combining power of l^drogen. We go up<m 
die supposidoQ (bat hydrogen eo^s into combination with oxygen to 
form water, in a smaller proportion than it enters into the consdtulion 
of any other body ; and also that there is no body whatever that en- 
ters isto combinatioD in so small a proportion as hydrogen. We 
have, it is true, only negative evidence in support of either of these 
propooitions, altbou^ the presumptios that diey are true aaiouDts al- 
most to certainty. But should it be hereafter discovered that hydro- 
gen enters into some combination in a less proportion than it exists in 
water ; or that some other element enters into combination in a pro- 
portion sdD smaller than any known proportion of hydrogen ; even 



* TtUi moM remarktble (act evidcDtlr depeod* upon IbB oclgfad e 
iMngi; uid li u truly H Iiw of the phyiieal uoiverae, uthatiUmvitittoniadlreet- 
ljr h the <|atiitltj at mMtT, and inveneljr w ttie •qnan iCUm oamca. 



OMzcdoyGoOgle 



then the mimariCB) rdations would not be in the-least disturbed, ariy 
the ntunbers expressiDg them would be doubled, tripled or quadru- 
pled, &c. according as the unit was placed lower in the scale. For 
instance, should we find a compound in which hydrogen exists in half 
the weight that it does in water ; then the composition of water, (the 
lowest known proportion of hydn^en being still unity,) would be ex- 
pressed by lot hydrogen and 16 of oxygen, and in the same manner 
nil other numbers expressing combining ratios would be doubled. 

(qq.) ITie foundation of the doctrine of definite pre^ortiom i 
jkerJbre laid in the comtittition of tMngt, and the fads dacovered by 
anaiytit, have been confirmed by calculation. — ^If discovery had pro- 
-ceeded no farther, the knowledge obtained would have been botli 
-highly valuable and inter'esdng, but it was reserved for Mr. Dalton,* 
to discover the next law wbidi, although built upon that which has 
been afa«ady announced, is perhaps still more extraordinary. 

(RR.) If two substances unite, in hkvkbal DirrKBEHT pbo- 

-rOKTIONS, THI lowest COHPOUm) WILL COHTAIN ONE, OB BOTB 
nUNClPLKSIN TBEIB BHALLEST COHBINIHO PBOPOKTIOS J AND IH 
THE BIGHEB, THE PBOPORTIONB WILL BE SUCH AS AB£ FBODCCES 
BT ICULTIPLTINCI THE LOWEST BT SOKE WHOLE NUMBEB. 

- Id « word, the higher proportions are multiples of the lowest, by 
^i whole number, or, (he diSerence will be expressed by a wbue 
-Dumber, and the bwest is general^ a divisor of the higher without 
-a remainder. 

In compounds of A-|-B, suppo^g the first compound to be of the 
smallest propcHiions of each, and that A remains constant, then the 
«ther compounds will be A-f-2B, ot -|-3B, or -|-4B. 

" The foIk>wing tablef will illustrate the subject 

Water b composed d hydrogen 1. oxygen S 

Deutoxide of hydrogen do. 

Carbonic oxide, 

Carbcmic acid, 

Nitrous oxide, 

PHtric oxide, 

Hjrponitrous acid. 

Nitrous acid, 

Nitric acid. 

In the two first lines, the pr(^x»li(Xi of hydrc^en is the same, while 
in the second that of the oxygen is doubled ; in the third and fourth 
Snes, fflmilar relations exist between carbon and oxygen, and in the 



" Of Hindiarier, EugUmd, who Ii itill living. t Turner, 2>) ed. p. lU. 



carbon 


6, 


do 


do. 


6, 


do. 


nitrogen 


14, 


do 


do. 


14, 




do. 


14, 


do 


do. 


14, 


do 


do. 


14, 


do 



D„tiidD,Googlc 



ATTRACTION, 163 

fear last, iflule the proportitm of niirogeD is comtant, that of the 
oxyma is double, tri^, quadruple, and quintupte. 

Tliis is the kw that has usually been called the law of multiples, 
or of multiple proportioDs, and diere can be do doubt that it is Hue 
to a very great extent, although, at present, we are prevented, by a 
very few apparent exceptioos, from regarding it as quite uoiTersal. 

Thus, hyOfogen being 1, lead is lepreseuted by the number 104, 
and mai^;ukese by 28, and each of these metals has three oxides, 
which are found to contain respectively, 8, 13, and 16 of oxyven, 
which is in the proportion of 1 1.5 and 3 ; so iron, whose equivawnt 
is 38 has, in its two oxides, 8 and 12 of oxygen, which also are in the 
proportion of 1, and 1.5. This does not correspond with the doc- 
trine of multiple proportiiMis ; the difficulty would, however, be re- 
moved, sbo«dd an oxide of each of these metals be discovered, with 
4 of oxygen, instead of 8 ; or possibly there may have been a roix- 
ti^ of oxides, as of the protoxide and peroxide of lead, thus eivmg 
origin to an apparent deutoude, which may not really exist." Sbould 
tbeM cases, however, prove hi the end to be excepdcais, they will 
not invalidate the truth of the general doctrine. 

(n.) The number repretenittig any totnpovnd iody it comptued rf_ 
lA« ttm of the numbert representing ttt parti. — Thus in sulphate 
of pota^, whose equivalent is 8B, sulphur 16, +3 proportkMis of 
o^gen 24^40, and potassa is composed of potassium 40, and 1 pro- 
portion of oxygen, 8=48, which -t-40=88; this will bold true of 
the most com^cated as well as of the most »mple compounds. 

This truth is well illustrated by all the salts. 

(tt.) " JTk retpective quantiiiet of any number of aOcaUne, earthy^ 
ana metallic bates required to saturate a given quantity of any acid, 
ore always in the same ratio to each other, to what acid soever they 
may be apjdied"f—Sod& 2 parts, and potassa three parts respective- 
ly, these numbers always bearing the same relation to eatJi other, 
and to some unit, saturate every acid ; soda is represented by 32, 
and potassa by 48, hydrogen being one, and 32 : 46 : : 2 : 3, as above, 
and these numbers therefore constantly represent the combining 
power of these two alkalies ; but the proportions of the different aciiu 
which will combine with these, and with other bases, will of course 
vaiy. 

(titt.) " The re^ective quantities of any number of adds requir- 
ed to saturate a given quantity of any base, are always in the 
tame ratio to each other, to what bate soever they may be t^lied"f 
^Tbis is only the converse of the other proposition, me relative pro- 
portioiis of any two acids that saturate a given base, will saturate any 



t Prat; OkMted, in Am. Jour. Vol. Xll, p. 1. 



OMzcdoyGoOgle 



164 ATTRACnON. 

otber base, BDd an diArefore called dtetnioal equhraleats, and ifae 
same b true of the bases, in relatioa U) the Kcida. 

Wensel, a German chemiai, proved, in a work pHbUabtd in 1777, 
Am two neutral salts that decompose each other, still preserve tfaeir 
neutrality ; neither acid nor b&se being in excess,* and RichteTt of 
Berlin, ilhiatrated this truth more fully in 1793. TUt could not 
kave been true, had not the relations of acids and bases been con- 
stant, as stated in the two last propositions. Thua, in su^>hite of 
BOtassa, the acid is in the jHrcmorDcm 40, and the alkali 48=88, and 
m nitrate of baiyta the acid is 54, and the eanh 78=133. Now 
irfien these salts are, by double decompositioB, convened into sul- 
phate of bar3rta, and nitrate of potassa, ue 64 parts of akric acid in 
ttte nitrate of baryta wiU saturate and be saturated by the 48 parti ot 
potassa in the sulphate of potassa, m^ing 1(3 (^ the new aak, ^ 
nitrate of potassa, and the 40 of su]{diunc acid in the tu^ihate of 
potassa, wul stiurate and bo saturated by the 78 tilt baryta, in die 
^trate of baryta, making 118 of the sulphue of baiyta. The ftets 
may be concisely expressed thus. 

Bifore detompatitioti. 

Sulphuric acid 40+ potassa 48=- 88 sulphate of potaasL 
^Titricacid 64+ baryu 78=133 nitrate of baryta. 
"^ 
After decompotiiion. 
Sulphuric acid 40+ baryta 78=118 sulphate of baryta. 
Nilricacid 64+ po&issa48a=103 nitrate of potassa. 

320" 
Tbe sum of the constituents being the same after decomposition 
as before, it is obvious there can be no excess of either. 

Thus then, hydrogen being unity, we are to infer diat 40, oc a 
miduple of it by a whole number, wUl always express the combiniog 
power of sulphuric acid, and so of other prmciples. 

(W.) CUEHICAL E^tTIVALEMTS AKE THOSK DCFIKITB ^UAKTI- 
TIES OP PABTICULAIt SUBSTANCES THAT SATUBATE DEFINITE QUAN- 
TITIES OF OTHEB SUBSTANCES. 

This is only expressu^ in the form of a proportion, what has been 
already stated ; namely, that a unit being cnosen, it becomes posable 
to express the combining power of all bodies, both simple and oom- 
pound, by numbers. Tqus, if Uie combining power of hydrogen be 



OMzcdoyGoOgle 



ATTRACTION. ]^ 

lOEproaed ly 1, dm of oxygen wiU be 8, &at of caiimn 6, dist of 
sulphur 16. If hydrogen aDtToxygen unite b one proportion of ea<^ 
lite compound inll be expressed by 9, — this is the number repre- 
senting vater, md every combination of water will be expressed by 
0, «■ 18, or 37, or 36, and so on, even to ten proportions, vrhidi 
would be ^nessed by dO. 

(w».) Jw eonAmii>g toei^ or powor of ahodp being onoe ttteer^ 
tamedf it tntt i^wa^ remain theigme; or it vnU atutmm the xme ra- 
tio m wertf Gom&taotMn.— 4f &e cotnbiDatkm takes j^ce in diffident 
pn^nions with a ^ven body, ^k number espressbg the loweajnv 
portiMi wiU be coBstimt, and the higher proportions will be multiples 
of it, by a whole nnraber. Thus, hydrogen being unity, oxygen will 
always enter into combination in the proporbcxi 8, 16, 24, 3S, ix, ; 
cut)on in die proportions 6, 12, IB, 34, 6bc. 'Hie oombming weights 
or powers of bodies, both simt^e and CMQpound, may therefore be pw- 
manently registered in a table of diemioal equivalests. Su(^ a ta- 
ble is now attached to eyery trense on chemistry, and is constantly 
referred to in practical operations, both of science and tit. It is an 
importimt auniiary, for we discora- by insiectitm n4iat quuitities 
of particular bodies saturste, or are equivalem ta each other. In 
the present wm^ the ohoaical equivalents, as for as they am asomv 
tuoed, win be found connected vrith each body, in its prc^ter plaoe, 
aoi dieywill be collected in a table at the end.* 

Dr. WMutOB't Scale cfcktmical e^ivaienU.f — ^This isa taUe rtf 
OOmbiDing or pr(q>onional wdghts, embracing those bo(fies ^at ara 
aaoBt IrequentW used in practical chemis&y. It diSers from other 
tables (Hily in um, that while the names of the eubstmices are station- 
ary, those of the numbo? are placed cm a sliding rule, divided logo- 
metrically, accordii^ to the principle of that of Gimter. The advan- 
tage of tiie instrument is, men, that it not only presents a table of 
chemical equivalents, but by moving the sliding ride iu a proper mait- 
ner, many proportions can be mechanically worked, widiout the 
trouble of calculation. Thus, it has been already stated, that sul- 
phate (rf* potassa is composed of acid 40+ potassa 48, and therefore 
88 is ^e number expressing die composition of the ssh ; hydrogeo 
being the unit, eB this win be seen, by placing the scale in such a pen 
ation that 8 is oppodte to oxygen ; but if we wi^ to know what 
would be the proportion of the acid and alkali, in 100 parts of sul- 
phate of potassa, we have -only to bring the scale into such a posi- 
tion, that 100 will be opposite to sulphate of potassa, when we shall 



* A van valuable Cable ii 
istrv, tjad Mr. Brande has p 
aa ftr M (liey are known. 

t For « deacriptlon oftUa bcautUiil huU oneM, tea the Plul. Tr. for 1814. 



OMzcdoyGoOglc 



read opposite to potassa M.6, and lo si^ihiiric acid 46.5, which is 
the composititHi in 100 parts. 

Dr. Wollaslon called oxygen 10. When this number was oppo- 
site to ozyeen, the other niunbers, therefore, estimated by that scale, 
representea " the combbbg wei^ts of the bodies opposite to which 
they may be found." " By mere inspection of this scale, we dis- 
cover the quanti^ of one body which enters into combination with 
another, the proponioas of the elements of cnnpounda, and (he 
quantities of these which enter into the compositioa of any partici>- 
ur weight of a compound ; the quantity of any substance required 
to decompose a compound, by conbimng with either of its ingredi- 
ents, and the quantity of the products diat will be formed." The 
progress of analysis has shewn that the numbers attached to Dr. Wol- 
laston's scale are, in many instances, incx>rrect, bm these errors have 
been rectified in more recent editions of the scale,* in which, also, 
the more convenient unit of hydrogen has been adopted. 

It is now ascertained that the ibundaiions of chemical combinadtn 
are laid in mathematical relations, and the proportions of bodies have 
therefore become subjects of mathematical calculadon, as well as of 
analydcal expenmeni. The mathematical relations are proved by 
analysis, to be true, and analysis is, in its turn, guided ana corrected 
by calculation. We may be assured that an analysis ia wrong if it 
does not correspond with numeiical ratios, and we may predict that 
the result wiU be expressed by one of a certain set of numbers, rela^ 
ted to each other by the same ratio, provided we are correctly ac- 
quainted with any one combinadon of the same principlea ; the new 
compound of these principles will bear a relation to them which may 
be ei^essed by whole numbers, although we cannot be certain 
whether it will be double, triple, quadruple ; or a half, or a third, 
or a fourth, Sec. of the one known ; it will be certain, or in the 
highest degree probable, that it will not be expressed by any inter- 
mediate number. 

This beautiful discovery, as its foundatioos are laid in the exact 
relations of quandty, places chemistry upon a mathematical basis. 

Mr. Higgms gave the first hint of ihis subject m 1788, in his view 
of the phlogbtic and and-phlogistic theory, but Mr. DahiHi first clear- 
ly explabed the doctrine. 

COMBINATION BI TOLUBfES. 

(XX.) Gaseous bodies unite bt volume, in the simple 
KATio or 1 TO 1, 1 TO 2, 1 TO 3, 1 TO 4, &c. — ^This law wag es- 



OMzcdoyGoOgle 



ATTaACTION. 187 

tabliahed by Gay I^ssac, and Humboldt,* and the first fact of the 
kind observed, was in the case of the elements of water, two vkA- 
umes of hydrogen combining with one vdume of ox^eo. 

The foUowing tablesf exhibit a number of facts of this class. 
Tolamei. Volainn. 

100 muriatic acid gas combine with 100 amratMiiacal gas. 

100 carbonic acid gas, " " 100 do. do. 

100 do. do. " *' 200 do. do. 

too nitrogen gas, " "50 oxygen gas. 

100 do. " " 100 do. 

100 do. « " 150 do. 

100 do. " " 200 do. 

100 do. " " 250 do. 

100 Chlorine gas, " " 100 hydrogen gas. 

100 nitrogen gas, " " 300 do. 

100 oxygen gas, " " 200 do. 

This table needs no comment ; supposing it to be accurate, of 
iriiich there can be no reasonable doubt, it fully supports the propo- 
rtion stated above. 

(jry.) Bodiet in the itate of vapor obey the $ame law. 
" 1 00 vols, hydrogen + 1 00 vols, vapor of sulphur = aulpfa'd hydrogeiu 
100 " oxygen +100 " " = sulphurous acid. 

100 " " +100 " iodme = bydriodic acid.*^ 

This view b carried so far as even to embrace solids, which, per- 
haps, have never been in the aeriform ccxidition, except in a state of 
combinaiion ; it is supposed that in that state, they wot^d obey the same 
rule. In the compound gases just mentioned, it is obnous that the 
specific gravity and proportion of the oxygen in sulphurous acid, and 
of the hydrogen in sulphuretted hydrogen bemg known, the balance 
of the weight of the gas under a given volume, must represent the 
sulphur in the state of vapor ; and the same remark will apply to the 
hydriodic acid ; we may include the carburetted hydrogen gases in 
the same view, for the specific gravity of the hydn^en which they 
ctHitain, and its proportion being known, it is obvious mat the remain- 
der of the wei^t m a ^ven volume must be carbon in a state of 
vapor. 

(zz.) When gases suffer condensation, in consequence of com- 
biaing, U ii alvmyt in a simple ratio to the tolmne of one of them.— ~ 
Ammonia is composed of 3 vols, of hydrogen + 1 vol. of^ nitrogen^ 
contracted into 2 vols, and in the formation of mtrous oxide gas there 



■ llMDdrai d'Arenefl. t Unmy, 6(1i Ed. Tol. l, p. ST. 



OMzcdoyGoOgle 



is a extraction to two thinls. In the fbrmstioiL of sulphurfltted h^- 
dn^en, and sulphurous acid, there is also a coatracdon to ooe half; 
and the same feet is seen in manr other cases. 

(aaa.) By knoteing tke speciftc gravity of the gtuet amporing a 
compound gas, mid the degree of condensation toKieA they undervo, 
tke specific gravity of the compound gat may he calculated. — Dr. 
Turner has given the following instances among o^rs. Ammonia, as 
just observed, contains 3 vols, hydrogen, and 1 of nitrogen, condensed 
into 3 vols. The sp. gr. of hydrogen is 0.0694, air being 1 , and that 
of nitrogen is 0.9732— therefore Uie latter number +0.0694 >: 3= 

— =0.3951, the sp. gr. which ammoniacal gas would bare, 

were there no contraction of the gases; but as they contract one half, 
the.sp. gr. will be double of that, or 0.5902, which is its weight, as 
ascertained br experiment by Sir H. Davy. Nitric oxide gas, be- 
ing composed of 100 vols, of oxygen, and 100 of nitrogen, united 
without contracdon, must form 200 volumes of the compound, 
and of course the sp. gr. must be the mean of its compon^USt or 
l.Ull+0.9722^^Q^^g^ ^jjj^ ^p^j^j^ ^^ ^^ average resalu 

of the best experiments. 

(666.) 7^ cofn6tn<i^ni 6y volume cimcide accurately vfiih the 
law ofnadiiple proportions, fir it is obvious thai double, triple, ^c. 
of the volume of a gas must also be double, triple, ^c. of the weight. 
—There is also an additional coincidence, that is not possessed by 
the compounds that are not aeriform. Although m them there is an 
arithmencal relation between the weights of the di^ent proportions of 
Hie some principle, there is no such correspondence between the dif- 
ferent principles of the same compound. Thus, between the 14 parts 
by weight, of nitrogen, and the 8 of oxygen, contained in nitrous 
oxide ; and the 14 and 16 parts of the same principles, in nitric ox- 
ide; and the 6 of carbon, and 8 of oxygen, in carbonic oxide ; and 
the 6 and 16 of die same principles in carix>nic acid, there is no mul- 
tiple reladon. 

(ccc.) In eom/nTiations of aJsriform bodies, there is a multiple re- 
lation, not only between the different proportions of the sameprijici- 
ple, bit ofthe different principles, that are united m the same com- 
pound. — -The table on page 167 proves this propoaUon to be true. 

(ddd.) In general, a volume of a gas represents a comJnning pro- 
portion. — Oxygen is the only exception ; m that gas, half a volume 
represents a combining proportion. This arises from the fact that in 
the lowest combination of oxygen known, it unites with two volumes 
of hydrogen, which are supposed to contain only one combining prOi- 
portion, and therefore the combining proportion of oxygen is conud- 
ered as contained in half a volume of that gas. 



OMzcdoyGoOgle 



ATTRACTION. ]69 

(«e.) Mthovgh, in general, there is no aritkvietical ratio betteeen 
the eombining proportions of different bodies, imdrogen forvu an ex- 
ertion. — ^According to Dr. Prout,* and Dr. Inomson,! " in every 
one of the compouDds of hydrogen, the proportion of the body united 
with it, is an exact multiple, by a whole number, of its own weight."J 
Thus, in water, (protoxide of hydrogen,) the oxygen is just 8 times 
theweighiofthehydrogen, whilein thedeutoside, itis 16 times; and 
in sulphuretted hydrogen, the sulphur is just IC times the weiglu 
of the hydrogen. 

ifff-) Berzeliut^ hat discovered that oxygen contained in different 
proximate principles of the same compound, eccists in a multiple ratio, 
or in equality, — ^Thus, hydrate of potassa is composed of potaasa 48, 
and of water Q, and there is 8 of oxygen in each of them. This law 
holds in earthy minerals, contauiing several oxides, and in the salts. 

Carbonate of potassa consists of carbonic acid 22, ctmiaining oxy- 
gen 16, and of [Wtassa 48, containing oxygen 8. 

Where water of crystallization m present, there is a simUar rela- 
tion. — Crystallized sulphate of soda contains sulphuric acid 40, ui 
which the oxygen is 34 ; soda 32, with oxygen 8, and water 90, 
with oxygen 80 ; and these numbers, 8, 34, and 80, consist of one, 
three, and ten proportions of oxygen. 

Compound salts obey the same law. — In tartrate of potassa and 
soda, the oxygen in the acid, and in the two alkalies is the same. 

(ggg-) " In each series of salts the same relation always exists 
between the oxygen of the acid and of the base." In the neutral sul- 
phates, the ratio is as 1 to 3— one in the alkali, and three in the acid. 
In the carbonates the acid is double, and in the bi-carbcHiates, quad- 
ruple the oxygen of the base. 

The illustrious discoverer of these ^ost remarkable laws, says that 
in the course of several years that have passed since he first (^serv- 
ed them, he has not detected any exception, and he therefore relies 
upon them implicitly, and is in the habit of calculating the compo- 
9tion of bodies upon this principle. |[ 

• Aniult of PhikMophy, Old Seriei, Vol. VI, p. S21. 

I Firat Prmdplei. 

t Tbii ii denied by Bcrteliui, who a«serti that il !■ IncatMUteDt with the rastUto of 
hU (Ditlyab. 
. \ This account of ths dlicoveries ^ Berzelliu. is ibridged from Dr. Tamer'* 
Cbemktry, 2d Ed. 

{{ For an able Tiew of (his aubject, see Hr. Turaer'a Chemistry, 3d Ed. p. 177.— 
He givgi the fotlowioi; geoeraliztition. Meet of the neutral Bulpbshn, all the alki- 
Une and euthy, and MTeral metallic sulpha(ei> of common motals, as iron, liac, and 
lead, cooaist of 1 proportiwt of acid, and I of baao ; (he acid eonlaiiu 1 proportion of 
■nlphur, 16, and 3 nf oiygen, 24, and every protoxide coniiats of malal 1 propor- 
thm, and oiygen 1^^. It will be seen by comparing Ihe numbera that 

1. "The oxygen of the acid is ■ multiple of that ol^he base." 

2. " The acid contiina Ihren times as much oxygen as the base." 

22 



OMzcdoyGoOgle 



THEOBT OF ATOMS- 

For a complete view of tlus cunoua and iatacstiiig specidatkm, re- 
couree must be had to the writings of Higgins, Dalton, Berzelius, 
Hiomson and others.* 

In the sketch that has been given of definite prc^rtions, I have in- 
teatioDa% avoided the use of the word atom, because it may be mi^ 
understood, and may lead beg^ers to confound facts with bjpothe- 
as. The doctrine of definite and multiple proportioiis is established 
oa the basis of experiment, and is fully confirmed both by analyas 
and calculation. 

The expresdons, combining weight, combining quantity, or cofnit*- 
•ngproptfritim, and cAemica/eainiiaZen^, all mean the same thing; and 
it may be added, that atota, and atomic eon^itiOion and atomic vxight, 
are used by most writers b (he same sense. The atomic hypodiesis, 
first suggested by Mr, Higguis, (1789,) was so fully detailed and ilhia- 
trated by Mr. Dalton, in his Chemical Philbsophy, that the theory is 
usually considered as his. It is ingenious and beatitiful, and there 
can be no reasfxtable doubt that matter has an atomic comtituticw ; 
but, that it is such as the atomic theory now in discussion supposes, 
although highly probable, cannot be demonstrated ; and it is there- 
toie important for the student to be able to distinguish it, or any odier 
atomic theory that may be proposed, from the luminous and oemc»- 
Atrated verity of definite and multiple proporDons. 

(AAA.) If we assume that bodies, in the comfainati<Hi in which they 
exist in the smallest proportions, unite atom end atom, then their re- 
lative weights in those cases, will represent those of tb^ arama. 
This assumption is the foundation of the atomic theory. 

(m.) There being no combination in which hydrogen is known to 
exist in smaller proportion than in water, and the specific gravity of 
hydrogen to o^gen being as 1:16, if these elements unite atom to 
Mom, and a volume of each represents an atom, then the relative 



8. "ThemlpburoTUie »cld i* just double the oxygen of the bue." 

4. The add ItrciriBjUBt five Ume* u much u thsoiygen of the bue. 

Metallic nlphurets often contain one prapoHion of each element, and when eon- 
Tertodlntoksalt, ^e lutnhuric acid and the protoxlda will bo eiaetly In thapropor- 
tton fi>r fennlng a matral mlpliftte of a protonide. 

InflMcaAontMiflieoxygenDfthe acid ia generally doable (hatof the base, and 
• rimUaruodeof reaaoniog Is applicable to the Tarlous genata of salts; bat nac<m- 
stiDt ratio eziMB between the quantity of oiide and that of the add, or of the oxygen 
la die acid, because the combmins weights of the tnetala Ihenuelvea are diflerent. 
All these fiicta are arranged naturally under Mr. Dalton's principle of multiple pro- * 
portions. 

An attempt has been made to extend the same views to the conitltulion of mbier- 
als.— See Ann. oTPhilosofihy.N. 8. Vol. IX, Mr. Children. 

■ See Hrary, lOth Locidon Ed. Vol. I, p. 42. Tfaonnon's First PrtncipleB of 
CliuniitTy, and Tamer and Hurray, 



OMzcdoyGoOgle 



ATTHACTION. 171 

weights of the atoms will be as those numbers ; but as h requires two 
voliunes of hydrogen gas to saturate <Mie volume of oxygeo gas, it 
follows that if the two volumes of hydn^ea be expressed by 1, viz. 
be regarded as one atom, half a volume of oxygen must be the 
equivalent of the hydrogen, and will be expressed by 8.* 

f^jif-) Either of these elementsf being taken as unity, ^en Uie 
weights of the atoms of other bodies may also be expressed by 
numbers, having an arithmetical relauon to those attached to these 
two elements, and thus we may construct a table of atomic weighs. 

(kkk.) If we could be certain that we actually know the kiwest pro- 
poitioDS in which bodies combine, and that in them the constituents 
are umted atom and atom, then ^eir definite proportions and their 
atomic wdghts would correspond ; oi at least they would be multiples 
and divisors, generally, of each other, and always by whole numbers. 

{lU.) But we can never be certain, that we either know the small- 
est combining quantities of bodies, (x that those quantlues, if known, 
are relatively in the proportion of atom and atom, or of one atom of 
one and of two of another, or vice versa, or of scftne other pro- 
portioD ; we cannot therefore be certain that our atomic hypothesis is 
true. 

(fflmm.) This however does not aSect the truth of the theory of 
multiple proportions ; that great discovery is independent of bypothe- 
as, because the exactness and ariihmeucal relation of the proportions 
is a matter of fact, and will still be true, whether ^e lowest combin- 
ation is formed by atom and atom of difierent bodies, or by tme atom 
of one and two of another, or the reverse ; or by any other assort- 
ment that may be imagined. 

(nnn.) The atomic theory is an elegant hypothesis, framed to ac- 
count for definite and multiple proportions, and may be either true 
or false without afiecdng ihat sublime truth, which deserves to be in- 
sciibed (Ml the same tablet with the laws of gravitation and projection. 

[ooo.) Still the hypothesis is highly probable, and the probabifin 
of its truth is much increased by its surprising coincidence with 
&cts. 

{ppp-) No student in chemistry, should however, imagine that the 
doctrme of definite and multiple proportions must stand or fall with 
the atomic theory. The latter may be discarded, without in the least 
a^cting the former; but the truth of the former is indispensable to 
the existence of the latter. 

I shall, as much as possible, avoid the use of the word atom, snce we 
have oO positive knowledge of the nature, fonns, number and weight 
of the atoms of any thmg ; as the word is short, it may however 

* See Ht. FlDch'i paper od the ttomie Iheory, Am. Jour. Vol. XIV, p. M- 
I Odur olemeiito mlgbt bave been uied ftir thii purpose ; but none ire equally 
conreideBt vlth oiygea and bydrogen. 



OMzcdoyGoOgle 



172 ATTRACTION, 

be convenieni to use it occasionally, but it vvilJ be understood by the 
reader, that nolliing more is intended by it than combining weight, 
combining proportion, or chemical equivalent.* 

It mil doubtless be thought by some, that the atomic theory should 
be presented more In detail. There can be no objection to its be- 
ing studied fully by those who are well versed in chemistry, but the 
learners of elements, for whom chiefly this work is intended, will, if 
they have mastered ihe doctrine of definite and multiple proportions, 
be able to go forward in tlieir studies without the atomic theory, and 
to understand that theory the better, the farther tliey proceed in the 
science. We do not, however, hold it in small consideration, and a 
sufficient number of opportunities of illustrating its nature, will pre- 
sent themselves in the study of the particular bodies.f 

APPENDIX TO ATTRACTION. 

Terratrial and artificial magitstiim, has an evident effect on chem- 
ical action. — Before leaving the subject of atu^ction, it ought to be 
remembered, that magnetism appears to be connected with it. Tinc- 
ture of purple cabbage placed m a syphon tube, is changed in fifteen 
minutes to green, by being connected by an iron wire, with the two 
poles of a magnet, and when the liquor was in two connected tubes, 
the same tiling happened, but it required two days to efiect the 
change, if 

A syphon tube, half an inch wide, and four and five bches long, 
having mercuty poured into the bend, but not sufficient to cut off the 
communication between the two branches ; the tube is then nearly 
filled with an acid solution of nitrate of silver. The tube being placed 
in the plane of the magnetic meridian, the precipitation of the arbor 
dians^ is much more rapid than when it is at right angles with it ; and it 
is much more abundant at the north than at the south end, and the 
crystals are more brilliant and longer, and more perfect. 

A bent tube placed across the magnetic meridian, and in which 
the crystallization has made little progress, exhibits it in increased 
acuvity, when two artificial magnets are approached, the north pole 



EH), Id a paper od the finite eiteot of lbs atmoipbere, published Id 
the Phil. Tramacllona far 1S22, hit reodcreil I[ probable that there are Btmupherl- 
cal iiomB incapable of fartlicr dirigfon. The qucatlon ti to the indivisibility of 
atoms, Is »phyairal topic, entirely independent of the malheroatical ppeculatlon as to 
the infinite dEviiibilily of matter j a Kpcculilion which aoemi however to have little 
ulilitT, and mmc would say, meaning, except with reference to physical elemenls. 

t Thenard liai fojloned this courac, Vol. I, Chem. p. 24, Ed. 6. I heard Mr. 
Dalton eiplain his own theory In his lecture rootn at Mancheater, and while I 
was enlerlained with the arranRemcntof his atouuc ayinbola, 1 was forcibly gtrueli 
with tho still grcaVer value of bis discovery of mulliplo proportions. 

t The sponlaccous chntigu i^ to red and no( to green. 

§ A laaciful Oania given tn this peculiar crybtallizatioti of silvery llio dispcaiUiHi 
of the rryslatB bciu;: in tirriniiic. and silver <f/»f formerly called Luna or Diina. 



OMzcdoyGoOgle 



ATTRACTION. 173 

of one to one leg, and the south pole of tlie otJier to ilie otlier leg of 
the syphon tube. Chcles of tallow being formed on glass plates, so- 
lution of nitrate of silver was placed within, and a circular piece of 
zioc in the centre ; the precipitation of silver was much more active 
towards the north, and the oxide of zinc inclined to the south ; a 
strong magnet being brought within two inches of a plate prepared, as 
before, the precipitation took place m one fourth of the tune, that it 
did on the plates that were beyond its mfluence.* 

****** 

We have now taken a preliminary view, perhaps sufficiendy ex- 
tensive and detailed, of the general doctrines of chemistry. This was 
indispensable, to enable us to understand the history of particular bo- 
dies, which is to follow ; and in giving it, I have endeavored, as far 
as practicable, to avoid anticipation; suU it is possible that some pas- 
sages may be unintelligible to a beginner ; as they are, however, not 
numerous, they may be omitted in the first reading, and being mark- 
ed in the margin by a pencil, they can be examined again at a more 
advanced stage of the subject, when the pupil has become more 
^miliar with chemical facts and reasoning. 

The preceding account of the general doctrines, although proba- 
bly sufficient for an introduction, is far from being complete, and ad- 
ditional illustrations will be given, when the proper facts come in 
out way. 

Belore proceeding to the history of particular bodies, it will be 
useful to gay something of the rules of philosophising, and of the ap- 
paratus and operations. 

I, Rules of Fhilosofhisino. — Limits of Human' Reason. 
1. God is the fibet cause of evert thino. 
(a.) All our observations f expertmenls and reasonings, make va 
acquainted only with second causes, 

{b.) The proximate came of an effect, is the one immediaiely an- 
tecedent to the event, or which is principally operative in produc- 
ifig it. 

(c.) To every proximate cause, there may be another proximate 
cause, and to that cause another; but the series wiU end at last in 
the power of the Creator, in immediate agency ; and this will stiU 
be the fact if we discover ever so many proximate cavsea, cojutitu- 
iittg a series or chain apparently endless. 

(d.) When lee have classified similar phenomena, and have dis- 
covered their modus operandi ; we say that we have found out the 
law that governs ikem; but still this harmony of facts and operauons, 
we must trace to the same source. 



■ Am. Jour. Vol. XVI, p. 262, and Ado. dc Chim. et de Phyiiqus. 



OMzcdoyGoOgle 



(e.) JViUiirai tdence it to be studied bj/ cbtervingfaeU, &» 
tt^enmentt, and then drawing ooncInMOfu j diis is the inductive or 
Baconian method of reastming, and is ibe foundation of legitimate 
tbeonr. Ad experiment is nothing but the exhibition of a fact. 

(y.) HypotMiet VMy be intro^iced in the lAtence cf trae theory 
ftmndid on indut^ion ; but fbey can be admitted ooly {ffovisionallj, 
until somethmg belter can be done.* 

(g.) We will add frran Sir Isaac Newton, that, " ne are to admt 
tto more catuea (^natural thit^s, than tach a* are both true and n^ir 
Gtenf to ex^ainlheir appearanca." 

( A.) " Thar^ore, to the tame tMtvral ^ects we mt«/, at far a* 
posiAle, att^H the tame causea."^ 

(t.) 7%e rang-e of human reaton is the whok extent of second 
eoHses. 

(j.) T%e final reason of a particular law it sometimet discovered 
by ui, and always magnifies the author. The unvarying proportion 
of oxygen gas in the atmosphere ; and the means by which it is pro- 
babfy sustmed ; the exception in the expansion of water between 32*^ 
and 40°; the phosphorescence of marine animals and of fiah gener- 
ally m the ocean, and the circulation of fluids and of aeriform bodies 
in currents to equalize temperature, are striking instances among mtd- 
titudes that might be adduced.^ 

(k.) 3^ moral effect of physical liudy upon every mind which hat 
been correctly disciplined, is lUtogether happy, and augments the vigor 
tf every proper fediitg. — It is not, however, to be dented, that an op- 
poate efibct is sometmies produced upon certain minds ; but this is 
the fault of the individual and not of the study. Kven moral study 
sometimes produces the same effect. 

{I.) Th^ greatest mental power and the longest life, joined with 
the greatest industry, can eruible man to compass only a imaU part of 
universal knowledge. — Of this, the wisest and the greatest men are 
the most sensible. Newton was not more distinguished for his vast 
powers and acquirements, than for his singular modesty. The im- 
portant suggestions at the end of his optics are in the form of queries, 
fnie whole amount of the knowledge of such a man, compared with 
all that a savage knows, is mdeed great ; but, compared with univer- 
sal knowledge, it is an evanescent point. 

n. Apparatus and oferatioits. 

Under the fiead of apparatus, we include aU the instruments and 
tdensHs employed in atemical experiments. — ^An experiment being, 
(as already observed,) only the exhibition of a fact, we want such 



OMzcdoyGoOgle 



ATTRACTION. 176 

instnuneats as vill oiable as to show fects ; ibey are for utility, and 
not for mere puade, but in a public establishment, el^ance maj 
be m a good degree, combined with utiKty. 

An apparatus is best exjdamcd, when it is used ; but a few fiicts 
may be stated advantageously in this stage of our progress, and tbe 
names of some leading instruments and operations may be given. 

A considerable number of instruments has ab«ady been mention- 
ed, but they have been chiefly those iriiicfa iUustrate general princi- 
fies, and the greater part have Deeii ven intelligible. For private re- 
search, and for the instruction of <»ly a tew p^w>ns at once, a oxnpt 
Gated and expeunve apparatus is not necessary. Much may be done 
by cheap and simple means.* StiU, it is an error to mippose that ro- 
fated analyms and difficult researches that demand great precisicm, 
can be accomj^shed without proper instruments, and various and 
sometimes expensive reagents ; nor can ftill effect be given befwe a 
large audience, to the fine experiments with which chemistry 
abounds, widiout an apparatus, and matniaJs corveaponding in some 
measure, to tbe ^loidpr and dignity <^ the subject. 

For a fill! account of chemical ^paratua and operations, die stu- 
dent is referred to Mr. Faraday's exceOent work on chemical mmi- 
pulations, where all the information that can be desired ia given. 

Apparaiut—vwimet of thinet — headi and hmtt. — ^Instruments of 
chemistry, to be perfect, should be, 

(a.) Transparent. 

(b.S Incapablb of corrosion. 

(c. J Incapable of fracture by heat and o(Ad. 

fd.) Strong to cmifine elastic vapors. 

(e.) Not liable to be melted or otherwise injured by beat. 

Glass, meta), and eardieu ware, collective^ possess oiese properties. 

Glan has the two first characters, in a sufficient degree, but not the 
rest; 

Metal, has sufitciently tbe third and fourth, and 

Porcelam or earthen ware, tbe fifUi, provided the beat is careful- 
ly managed. 

I. Jaiana ofprodudng heat. 

(a.) Fttel, if€. — Charcoal, coak, anthrafite and other coals ; wood, 
(h1, alcohol, eih^g hydrogen gas ; this gas and oxygen ; friction, per- 
cussion, fermentation, diemioal mixtures. ' 

3. /n/fnunend tn which, and metma by wAtcA the appKeation m to 
iemade. 



* I beatd Dr. Priedy tay, that his principal ioatruBienta were guQ b*mli> g)** 
tobei, flMki, Thli ud corlu, tnd It h well Imcnra that Tew rnanbBve rnKdomore 
diTCOveriei. StUI he wm ft plonoer ; he wu »lw»y»<m tmoit of dlawrary, M hta 
cnendooi were not in gtnenl •<> remariikble for nfiuncnt, m ftr «*«>»? "" 
enect. 



J cy Google 



176 ATTRACTION. 

(a.) Furmuxs, Black's, cnicible furnace, table furnaces, Lewis*, 
Eur furnaces, forge furaace. The genera] principles of all furnaces 
are the same. The principal parts are an ash pit and register, a 
grate, a body, a top, and a chimney. Argand's lamp, spirit lamp, 
mouth blowpipe, table blowpipe or Artists', Dr. Hare's, compound 
and hydrostatic, electric and galvanic apparatus, and burning lenses, 
and mirrors are useful means of producing heat. 

3. VttttU to be vaed wtlA heat. 

(a.) Forjiinon. — Crucibles, Hessian, Wedgewood, Au^an or 
black lead, charcoal, platinum, gold, silver. 

(6.) Fvr mixture. — All vessels may be employed fw these pur- 
poses, provided the agents do not act on them. For the solution 
of salts in the cold, most vessels will answer ; wiih heat, they 
must hear expansion and contraction. For metallic solutions, they 
must generally be of glass or earthen ; a platinum crucible may 
however be employed for many metallic solutions. 

(c.) For evaporationa, dietUlatioru, niblimations, — For evapora- 
tion. — Earthen pans, glass dishes, watch glasses, saucers, plates, and 
porcelam, and metal capsules ; those of platinum are very valuable ; 
bottoms of retorts and mattrasses are useful. Almost all vessels an- 
swer for crystallizations. 

For disttltationt. — Common still, with its worm and refrigeratory, 
mattrasses, oil flasks, tubulated and plain retorts and receivers of glass, 
iron, earthen ware, lead, silver, and gold or platinum ; bent glass tubes, 
closed at one end. 

For concentration, decoction, dtgettion, — Papin's digester, or other 
strong boiler with tubes and stop cocks ; occasionally, almost all ves- 
sels are used for boiling. 

(d.) For atihlimation. — Most of the vessels last named. Baths of 
water, sand, ashes, steam, oil, mercury, hot air, alcohol, brine, &c. 
Alembics of glass, metal, &c. 

'. Pneumatic appakatus and miscellaneous articles. 



(a.) Hydro^neumatic ctttem and air jars. 

(b.) ^krcunal trough, usually of stone, furnished with tubes of 
glass. 

(c.) An- pump and its appendages. Condensuig syringes. 

(d.) Gaxometert of different ^zes for different purposes. Ekidi- 
ometers and graduatetl glass jars, graduated tubes, detonating tubes, 
Woulfe's apparatus, and Dr. Hare's improvements ; do. for impreg- 
nating with carbonic acid gas. Stands, supports, &c. of iron and 
brass ; barometer and thermometer ; instruments for specific gravity. 

5. Mechanical operations PREPAKAToav. 

(a.) Trituration. — Mortars of marble, iron, steel, glass, porcelain, 
jasper, porphyry, agate, wood, granite. 

fA.) Lmigation. — The rubbing stone and muUer. 

(c.) Pulverization. — Ra^, files, graters, hammers, anvil. 



OMzcdoyGoOgle 



(d.\ Weighing. — Scales, coarse and fine, very seonble balances. 
1 S^ing. — Seires, of various fineness, with and without covers. 
) Xtecantation. — Syphons, coffee pots, &£c. 
^ ) Filtration, — ^Unsized paper of various quality, pounded glass, 
fiannel, Sltenng stones, sand, &c. Filtering funnels and stands. 

6. iiUTtS. 

FkniT and water, lye paste ; sand, flour and clay ; fat lute, com- 
posed of clsy and oil, lime and white of an egg. 

7. Vessels for EEcriNo pkoducts. 

Ground glass slopped bottles for deliquescent salts ; wide mouth- 
ed bottles ; ctxnmon vessels of any description. T^n cases for phos- 
phorus bottles. 

Drawers, mmeralc^ical cabinet, bladders and silk bags, for the pur- 
pose of administeiing gases. 

8. Labokatort — generalidea of one. — Any convenient, light, dry, 
and well ventilated place for the performance of experiments. Neat- 

I, order, and care of one's person and clothes and premises are in- 



Necesdnr of caution and presence of mind. Unreasonable fears 
of chemical experiments. Frequent ventilation of a laboratory ne- 
cessary. 

Speeijic gravity. 

The specific gravity of a body is its weight under a ^vea vohune. 
It is often necessary in chemical experiments, to tftke the specific 
gravity of bodies. Am^e instructions are given on this subject, in 
every book of Natural Philosophy, and for the present, mention will 
be made only of its application to gaseous bodies. 

It may however he stated, for the sake of those who have not 
more delicate apparatus, that common money scales are sufficiently 
exact for most purposes. A fi^gment of the substance to be weigh- 
ed, raav be suspended by a fine thread or piece of sewing silk, fi^n 
die pomt of bearing of one arm of the balance, the thread bdng 
long Plough to allow the fragment to swing below the scale so as to 
admit of immersion in pure water ; we then proceed as is usual in 
aroilar cases. Dr. Hare has several iugenious contrivances and in- 
ventbns for taking specific gravities, which may be seen in his con^ 
pendium, and in the American Journal of Science, aud if there ia 
room, they may be given in an appendix to this work. 

The specific gravity of fluids is easily taken by weighing tbem in 
a thm vial with a narrou^neck, having a mark upon it so that the same 
volume may he eaaly taken ; it is most convenient that the vial ^xxild 
hdd 1000 grains of distilled water. 
23 



OMzcdoyGoOgle 



178 ATTRACTION. 

Method of otcertotnin^ (Ae ^eajie gravitiet of the gates. — Dr. 



" Suppose the globe, A, 
to be removed from the 
receiver, R, and exhausted 
during a temponuy at- 
lacbment to an ur pwap^ 
by means of a screw with 
which the globe is Jiir- 
nished, and wluch serves 
also to fasten it to the re- 
ceiver, as represented in 
the figure. Being [re- 
served m this state of ex- 
haustion, hj cloEdng the 
cock, let it be suspended 
from a scale beam, and 
accurate^ countenmised ; 
air being then aooaitted, 
mil cause it to preponde- 
rate decidedly. If Id lieu 
of admittiDg air, the globe 
be restcared to the situatitm 
in which it spears in this 
figure, so as to be filled 
with hydnwen from the 
receiver, R, and aftee- 
wards once more sus- 
pended irom the beam, in- 
stead of prep(»ideratingd^ 
cidedly, as when air was 
allowed to enter; tmless 
the balance be veir deli- 
cate, (he additional weight, arising from the admission of the hydro- 
gen, will scarcely be perceptible. Supposing, however, that the- ad- 
ditional weight thus acquired, were detected ; and also the weight 
gained by the admission of exactly the same bulk of atmospbttic air, 
after a similar exhaustion of the globe, the weights of equ^ volumes 
of hydrogen and air, would be represented by me weights thus ascer- 
tained. The specific gravity of atmospheric air is the unit, in mul- 
tiples, or fractions of which, the specific gravities of the gases are ex- 
pressed. Hence the weight of any given bulk of hydrogen, divided 
by the weight of an equal bulk of air, gives the specific gravity of 



OMzcdoyGoOglc 



ATnUCTlON. 179 

bfdtogai. By a anular process, the specific graviqr of any otbw 
gas may be discovered-*' 

" The apparatus fbr ascertaiimig specific gravities, ahove reweseat- 
ed, is that which is rectMnmended by Henry. The gas may be more 
accurate^ measured, by usiog one of the volometera."* 

" The wei^t of any given number of cubic inches of ur or gaS| 
as (Hte hundred, for insunce, may be knovm by introducing a certain 
quantvnr into the globe, as above described, and noticing ttie acce^ 
sion of weight : then, as the number of cubic inches introduced, is to 
the weight gained by its introduction, so is one hundred to the weight 
of one hunted cubic inches of th^ fluid." 

" The number of cubic inches introduced, may be known by means 
of the graduation on the receiver, R." 

If there be a column of water or mercury standing in the jar, die 
^s will be less compressed than If there were no such column. 
Therefore, the density will be invernltf — the volume directlif as 
the height of this column. Hence, to ascertain the volume, say 
H : H—h::v : x. Here, H is the height of the barometer, A the 
height of the column,-|- v the observed volume, and x the volume re- 
quired. 

In weiehing the gases in order that the result may be correct, the 
gas should be pure ; it should be dry, or due allowance should be 
made for watery vapor, and if the expenment is not made when the 
barometer is at 30 indies, and the thermometer at 60°, the observ- 
ed volume should be reduced by calculation, to what it would be, at 
the medium temperaturej and pressure. 

The puri^ must be secured and ascertained by the modes appro- 
priate to eadi particular gas. 

Moisture must be removed, as far as possible, by exposure to dry- 
muriate of lime, quick lime recendy ignited, or fiised potash ; or other 
substances that powerfully attract water -^ 

For temperature ; the volume of a gas is as the temperature direct- 
ly, and as operatioiu on gases are almost always carried (hi above 32'', 
we first ascertain the volume that the gas would occupy at that ten^ 
perature, which is done by multiplying the total volume byj| 480* 
and (fividing the product by|| 480, -f- the number of degrees that the 



■ CMtof 

i GJorea ahoDld^ be worn while handling the Teasel*, or they ahonld be lillad bj 
die keya of the stop cocks, thai the warmth of the hands may not caute aTpwukia tn 

$ ForageiMnllbniiDli, weHBary.SlhEd. Vol. I, p. 2S, »iidTanwr,2dEd. Td. 
I. p. 71. 
H Beetiuie > gw eiptndi i|( {nrl oritt valume b; every decree of beat. 



OMzcdoyGoOgle 



190 ATTRACTION. 

temperature is above 32° Fahr. Then to determine its ndume at 
toy other temperature," add jj, of the volume at 33°, for each de- 
gree that the temperature required, exceeds 32=^ Fahr. Thus, to 
find what space 100 cubic indies of gas at 50° would occupy, if 

raised to 60° ^°^^'*^o =96.4, the volume at 33% and 96.4+ 
4o0 X 18 

^•'^^^=102, the volume at 60°"*— iTmru. 
480 * 

For praiure ; the volume of a gas « invertely as the preaure. — 
To reduce the volume to what it would be at 30 inches, the mean 
pressure, " as the mean height is to the observed height, so is the 
observed volume to the volume required. Suppose the barometer to 
stand at 29 inches, and that we wish to ascertain what volume 100 
cubicinchesofgas would occupy at 30 inches, 30 ; 29: ; 100 : 96.66, 
which last number is the answer required. 

For both presttire and temperature. — Suppose the question is, what 
volume would 100 cubic inches of gas, estimated at 50° of Fahr. 
and 39 inches of the barometer occup]' at 60° and 30 inches. By 
first correcting the temperature, we find that the 100 cubic inches, 
would be 102, and then, 30 ; 39 : : 102 : 98.6. 

7^ wetghi of a given volume of gas beiw known at any temper- 
ature, to learn what would be the vxigfit of an equal volume at the 
mean temperature. — The volume being given, the weight will be di- 
rectly as the pressure. Correct the bulk to the mean temperature ; 
*' then say, as the corrected bulk is to the actual weight, so is ihe ob- 
served bulk to the number required." 100 cub. in. of gas weighing 
50 grains at 50° Fahr. would ai 60° occupy 102 cub. in. and 
102 : 60: : 100 : 49.02, which would be the weight of 100 cub. in. 
at 60°. 

From the weight ofa^ven volume ofga$ ai an observed pressure, 
to ateertain WMt would be iis weight um2er the meanpressure ; say, 
" as the observed pressure is to the mean pressure, so is the observed 
weight to the corrected weight." 100 cub. in. of gas at 29 of the 
barometer, weight 50, what would it weigh at 30 inches pressure. 
29 : 30: :50 : 51.72, the fourth term being the answer. 

To combine both the last calndations. — 100 cub. in. of gas, at 50° 
Fahr. and 29 in. pressure, weight 50 grains, what would it weigh at 
60° Fahr. and 30 inches pressure ; first make the correction for 
temperature, vHncU gives for the weight under a given volume, 49.02, 
then, 29 : 30: :49.02 : 50.71, which is the answer tequired.f 



OMzcdoyGoOgle 



ATTRACTION. 181 

Pwmna^ Cittemi. 
Dr. Hales, more than a century ago, employed an apparatus upon 
the principle of the modem pneumatic cistern, wiiich was introduced 
by Dr. Priestley. This instniinent is httle else than a vessel suffi- 
ciently capacious, filled with water or quicksilver, and funiished with 
fixed shelves and a sliding shelf. The apparatus for mercury is usu- 
ally small, on account of the weight and expense of the metal, and 
ounce measures are used where, in the other apparatus, we employ 

3 uarts or gallons of water. In bo^, for the purpose of expelling the air, 
le vessels are filled with the fluid, and then, they being inverted with 
their mouths under it, the gas is introduced fi'om below. The an- 
nexed cut represents the mercurial cistern used by Dr. Hare ; it is, 
however, five or six times larger than those generally employed. 
This kind of cistern is rarely used, except when the gases are rapid- 
ly absorbable by water. That in the laboratory of Yale College, is 
of marble,* and of a similar construction, but holds not over two hun- 
dred pounds of mercury, and usually from one hundred and fifty to 
one hundred and sixty pounds. 

Mercurial Cutem for gaset. 



" B B, is a wooden box, which encloses the reservoir so es to 
catch any of the metal which may be spilled over the mar^n of tlie 
cistern. This box is bottomed upon stout pieces of scantling, tenant- 
ed together and grooved so as to conduct the mercury towards one 
comer, where there is a spout to allow it to escape into a vessel, mIu- 
atcd so as to receive it. The cistern itself, is made out of a solid 
block of white marble. It is twenty seven inches long, twenty four 
inches wide, and ten inches deep." 

" The ledges, S S, answer for the same purposes as the shelves in 
the common pneumatic cistern. The excavation, to, is the well in 
which vessels are filled witli mercu^, in order to be inverted and 
placed, while full, on the ledges. There arc some round htJca in 

■ Prof. HitcUcocli, ot Amherst ColleRe. )>w one of mp Mod*. 



d.^Goot^Ic 



193 ATTRACTION. 

tbe marble for introducing upr^t wires to hold tubes, or Eudiome- 
ters ; also some oblong mortices, for allowiog the ends of tubes, duly 
recnrved, to enter under tbe edges of vessels to be filled with gas ; — 
and in cases of rapid absorption, to aSbrd a passage for tbe mercury, 
into vesseb, from which it might othemise be excluded, in conse- 
quence of dieir close contact, with tbe marble of the reservoir." 

" This reservoir requires nearly six hundred pounds of mercury 
to fill it completely." 

Water eiitem for gata. 

Any vessel containing water in sufficient depth to admit of filling 
the air glasses, will answer in some good degree. There is in the 
laboratory of Yale College, a pneumatic cistern constructed in 1803, , 
of which an engraving was given in the editions of Henry's Chemis- 
try published by me, and which has been foimd very convenient. It 
is furnished with air cells, which may be understood by an inspec- 
lion of Dr. Hare's figure below. In mine, there were only the up- 
per cells here represented under A A, but dinded each into two 
compartments, and nearly bene^ them and under water,- were hy- 
drostatic bellows, for throwing in air and gas. From the cells, also, 
proceeded tubes for tbe compound blowpipe, but the apparatus in 
front, representing the arched tubes and die inverted kettle and iu 
ueadle, and also the other lower cells under C C, were not in mine. 
Sj/dro-fTieumatic Cirtem o/* Dr. Hart. 



*' The figure, here given, is such as would be presented to the eye, 
were the front of the cistern removed." 

"A A, are two shelves formed by two bverted chests, which are 
used as cells to contain gas : B is a sUding shelf, over a deep place 
between the shelves, A A, which is called the well of the cistern." 



OMzcdoyGoOgle 



ATTRACTION. 183 

Fig. 2. 

" Fig. 2 afibrds a view of the lower sde 
of the ^diDg shelf, in the wood of which 
[ it will be seen that there are two excava- 
f tioDS, coDverglng into two holes, one of 
which is seen at A, fig. 1. — This shelf is 
loaded with an ingot of lead at h, to prevent it from floating in the 
water of the cistern." 

" Besides the chests abovementioned, there are two others, C C, 
near the'bottom of the cistern, but not so close as to prevent the wa- 
ter from passing freely into and out of them." 

Referring to Dr. Hare's Compendium for the reminder of the 
description, I wfll add only, that the inverted kettle by a treadle be- 
low, and by the aid of a pecvdiar internal constnictioD, is made to 
throw m air ibrough the kmer arched tubes, into the cells under 
C C, which are mtMided for r^ulating the height of the water ; while 
it is allowed to esc^e through tbe upper arched tubes at their eont- 
nuHi cnfice at/. The cells under A A, are for reo^ving any gas 
not absorbable by water, and it is easily drawn off at ihe coeksatee, 
into vessels standing m the shelves A A. 

The student will not suppose that, atricdy, any thin^ moto is ne- 
cessary for a pneumatic cistern, than a water vessel with a fixed dwlf 
or Aelves as at A A, and a sliding ^elf as at B, and even the laa«- 
may be dimwnsed with by making boles through one of tbe fixed 
shelves, and intioducmg an inverted funneL 

eikZOMETSBS. 

Gaxometfirs are important in many chemical experiments. la 
ccHitriving the pneumatic cistern mentioned above, if was one object 
to furnish gaEometers in the cistern itself, where most of tbe gases 
are prepared ; and there was, for many purposes, great utility in (he 
contrivance ; but the gases being always under pressure, vrere of 
course liable to escape at any leak. 

There is so much convenience, however, in occupying with ur 
cells, this otherwise useless space, that I should still recommend this 
mode of construction, of the pneumatic cistern, so far as the cells are 
concerned ; without attempting any thing farther, except the neces- 
sary appendages to draw off the gases. 

On the whole, I have found the most useful species of gazometer 
to be the following, which, it will be perceived, is only a modifica- 
tion of the form generally used, 

]. The containing air vessel Is made of tinned iron, or the thin- 
nest sheet copper, painted and varnished : the form is cylindrical, as at 



OMzcdoyGoOgle 



5' 8J- 



A, and there 13 a smaller cylinder, a,* ri^g in the centre to receive 
an mterior gas pipe ; the rings are to receive the cords that are to 
suspend the cylinder by passing over pully wheeb at cc, 6g. 2. 

3. D is a slightly conical cask, to be filled with water in p^ch A 
Is suspended by the cords already mentioned, and which are weight- 
ed at if (2, so as to keep the air vessel in equilibrio. 

3. Fig. 3 represents a tube of copper or lead, which is fastened 
widiin the cask D, 50 that the Umb/ rises in the center and passes up 
into a, fig. 1, when the air vessel is down, and the stop cock m is 
open, for the escape of the conamon air. The other limb e is fas- 
tened firmly to the cask at the side. 

4. Fig. 4 represents the mouths of two of the interior tubes widi 
addirional tubes fitted air ught, with corks through the trumpet shap- 
ed orifices, i %, and terminating, after curvature, in a fhistrum of pla- 
tinum aty. This apparatus of tubes is used for the compound or 
oxy-hydrogen blowpipe of Dr. Hare, and can be taken off by double 
jointed screws at 0, and also at t i, and any other apparatus can be 
attached. At bb, is a. thin slip of wood, acdng both as a guide and 
a scale to the air vessel. 

It is obvious that if there are two casks and two au- vessels, they 
will form convenient reservoirs for oxygen and hydrogen. Mine 
contain together fifty gallons, and by means of weights laid on the air 
vessels, the gases are made to issue at j, witli all necessary force. 
Nothing can be more convenient for the compound blowpipe ; for the 
ozygeo or the hydrogen blon'pipe alone ; for the common air blowpipe ; 
for gas lights; for musical tones with hydrogen; for communicating 
oxygen and hydrogen through a tube to the pneumadc cistern, and 
for many other purposes, sufficienUy obvious to a practical chemist. 
Smaller instruments upon this principle, are convement for the respi- 
ration of gases, a proper mouth piece being fitted toeg,&g. 3. 

' WUdi may be fiuulibed with a »mali stop cock, t 



OMzcdoyGoOgle 



Part II.— PONDERABLE BODIES. 

htroduetory Remark. 

I stULL here repeat what was stated in the IntroductioDf p. IS, 
diat a real element it an undecon^otable body ; that, in relatwn to 
our knov^dge, an etaneni it merely an undecompoted body. 

Our evidence on this subject being only negative, it f<wow3 that 
any body and all bodies, now admitted as elementary, may hereftfter 
be decomposed. 

Should we, for argument's sake, admit the improbable result, that 
■U compound bodies may be hereafter reduced to two, the smallest 
nvmber of pnociples with wlucb it is possible to form a third body, 
we should even then not be certain, that these two were real ele- 
ments ; for they might be decomposed into two, three, or four others, 
and they again into fire, six, seven, or eight others, and so on ; pro- 
ceeding from the greatest apparent simplicity, to ihe greatest com- 
plezness. 

It is proper to recal to the recollection of tbe student, that the ati- 
cient hypothetical elements, earth, air, fire and water, have all been 
proved to be compound, and Uiat there are dow more than fifty* un- 
decomposed bodies, among which are three supporters of combustion, 
oxygen, chlorine and iodine ; about forty metus, and seven combusti- 
bles, that are not metallic, namely, phosphorus, carbon, hydrogen, sul- 
phur, nitrogen, boron and selenium. Nitrogen, as already observed, 
IS thrown into this class, as resembling them very much in its relations 
and character, although it is not in the popular sense a combustible. 

INOBOANIC BODICS. 

SmPLB SOPPOATEBS OF COKBDSTION. 

SEC. I. OXTGEM. 

1. Name, Oxygen,f derived from ifye and ytiwiuu or ymSLu, signi- 
^ii^, dierefore, Uie gen^alor of acids ; a name imposed by the 
Iramers of the new nomeDclature ; the former names were, depblo- 

* Dr. ToriMr'i Id edUoD, ^rea Gflr two, including bromine ud wleoium. 

t Several autbon, (u Thenard, BIh Ed. Vol. I, p. 186,) condder die nana axfgaa 
at impniper, bbcauie 11 la not the loU acidifier ; but K ii Ihe great ruling acldlfieri It 
being the Mie agent In aJmori all caul, and therebre Ihe name ia proper. W« 
might ei well reject the name chlorine, becauee il it not the only grauiub yaDoir 

''' 24 



OMzcdoyGoOt^IC 



ISe OXYGEN 

gisticated air, vital air, empyreal or (ire aii, and pure air, which hare 
all yielded to (he name oxygen. 

2. Processes. 

(o.) There are several ; the most useful is by igniting the purest* 
black oxide of manganese in an iron bottlef or earthen retort ; one 
ounce of the oxide anbrds about one hundred and twenty eight cubic 
uichee of gas. 

(i.) Si^phuric acid 1 part, mixed with the same mineral 3 parts, 
to the consistence of a paste, and heated moderately) affi»ds tlus 
gas ; the theory of these experiments will be given faereaiter. 

(c.) Other modes will be mentioned farther on, su<di aa that of 
heatiog the chlorate or nitrate of potash,! °' ^ roixtine of red lead 
and sulphuric acid j and that from green leaves placed in water ta 
the sun's light, inc. The gas b received in inverted glasses full of 
water. 

3. Discovert — 

(o.) By Dr. Priestley,^ in England, August, 1774, by heutng 
red oxide of mercury, in a bell glass by the solar fixsus. 

(6.) By Scheele, in Sweden, the year after, and without a knowl- 
edge of Dr. Priestley's discovery ; and also by Lavoi^er, at Paria, hi 
the same yea;. 

4. FbTSICAI. PBOPKBTIHS. 

(a.) Trantparent, colorieu, tattdeaa, inodorwu, not eondeniAlo 
hy preMiun md coldy a non-eondvcior of electricity. 

0>-) Sp. gt. 1.1111, au- bemg 1. — Tkomion. 

(c.) Wei^t 33.6888 for 100 cub. in. at the medium temperature 
ana pressure. — Id. 

ia.) Refracts light less powerfully than any other gas. 
eS Becomes luminousfl as well aa hot, by sudden coodeosetion. 
f.) It is a non-conductor of electricity. 
6. Chekicai. properties. 

(a.) Itpouaiet more extetuive power* of combijuOion than other 
tuhstance. 



* It 1j sometlinei previously waalied with h weak mineral add, to dBcompose cn- 
boiuite ofUinejlfiay iBpreseoL 

t A wrought iron bottle, with a wide tube aboal two feel loDg welded to ft, !■ 
mvch Uie beit liMtrament; itibmld be coated, every Umeit la uied, witb ■. lute of 
clay, aand, and floor, applied with the hftod and dried before uifsg. A gun barrel 
aniwera for a amall experimcuL 

% Dr. TbomaoD eaya (hat the first 6th of the gas from nitre is quite pure, and I^. 
Hare confirms the alatement, that tbe iint portions are quite purs. 

J I See Prleatley's account In his work on air. 
I All (he gaeea become hot by suilJcn preasure, bu( chlorioe and oxyzen are (he 
J almple fpaea that become luminous in this manner ; common air tiecomea 
ItimiDoui by the same treatment, but In a less degree than oxygen, to which gas, 
this property in air ia owinfr. 



J cy Google 



OXYGEN 187 

(B.) It acts on combustible bodies with intense enerot, 
and this is one of its gretu characteristic, but not altogetlier peculiar 
properties. 

(c.) Generally the temperatwe mitst be raited, in order io bring 
OH the action. 

(d.)* A lighted candle bums brilliantly in oxygen gas- If extin- 
guished, (fire remaining on the wick,) it is instantly rebghted with a 
slight report, and that many times in succession.f 

Candle in air, in vacuo, and in oxygen gas. — Dr. Hare. 



" Lei there be two bell glasses, A and B, communicatiag with 
each other by a flexible leaden pipe, a cock intervening at C— Sup- 
pose A, to be placed over a Lghted candle aa the plate D, which 
communicates with an air pump plate as represented at E. — It will 
be found that the candle mil gradually bum more dimly, and will at 
last go out, if no supply of fresh air be allowed to enter the contain- 
ing beU } if on repeatmg the experiment, the air be withdrawn by 
means of the pump, the candle is rapidly extinguished. It is thus 
demonstrated, that a candle will not bum in vacuo, and that it can 
burn only for a limited time, in a limited portion of atmospheric air." 

" Let the experiment be repeated with the following change. Let 
the air be exhausted from both vessels, the cock, C, remaining open, 



If incluied each timo tbe candle nick is presented (o it ; aa the oi;gea u 
coDiumod or expetlci], (he boule must be (uraed down mora and marG. A 
candle in a socket, 6\ci to a uiri;, ii easily let dotva Into a jar of gas, as rep- 
resented in tlie cut. 



OMzcdoyGoOt^IC 



uDtil the bell, B, is 611e<i with water from tlie shelf of the pneumaiic 
cisterD, on which, for this experiment, it must be placed. The 
cock being closed, fill the bell, kst mentioned, with oxygen gas, bom 
the cell of the cisteni. Now lift the bell A, which may be eanly 
done, the pipe having a due flexibihty, and mtroducing a candle, set 
the bell again on the plate. Next exhaust the air until the candle 
is nearly extinguished, and then open the cock, so as to allow the 
oxygen to enter. — The candle will now bum brilliantly for a much 
longer time, than it had done, when the bell contained atmospheric 
air." 

(e.) Ignited charcoal bums intensely in this gas, and the bark with 
nvid scmtillatJons. 

(/■) Iron wire or a watch ^ring, with a lighted sulphur matdi oa 
Ibe end, bums with bright ignition and sparks, but without flame. 

Combuition of iron toire in oxygen gat, — Id. 

" Place over the cock of 
one of the cells of the pneu- 
matic cistern, sufficiently 
supplied with oxygen gss, a 
glass vessel, such as b usu- 
ally employed to shelter can- 
dles frcwn currents of air. 
Let the upper opening of 
the vessel be closed, by a 
lid with a central circular 
aperture, as here represent- 
ed. Leaving this aperture 
open, by tummg the key 
oi the cock, allow the gas 
to rise into the vessel from 
ihe cell. Next apply a ta- 
per to the aperture, and as 
soon as it indicates by an in- 
creased brilliancy of com- 
bustion, that oxygen has 
taken place of the air pre- 
viously in the vessel, cover 
the aperture.* Wmd a fine 
wire round any hard cyHn- 



veying the orifice ofi curved tube to die baltDm of the veisel, the other end of Ihe 
lube belog connected nilh a gazometer or olhci' reservoir, from which the giu it 
•llowed to flow i the aliDO£(>bere ii thus ItJied out and the oxygen takes tli {iImc. 



D,q,fzodbyGo(lg[e 



OXTOEN. 189 

dHcal body of about an inch in diameter.* Bytfaese means, the wire 
is easily^ made to assume the form of a spiral. Near the end of the 
spiral, wind it about a piece of spunk about as large as a pin. Hav- 
ing lighted ihe spunk, remove the cover from the aperture in the lid 
ofthe vessel, and lower the end of the wire to which the spunk may 
be attached, into the oxygen gas. The access of the oxygen causes 
the apunk to be ignited so vividly, that the wire takes fire and hums 
frith great ^lendor, forming a brilliant liquid globule, which scintil- 
lates beauliiiilly. This gbbule is so intensely hot, that sometimes on 
falling, it cannot immediately sink into the water ; but leaps about ou 
die surface, in consequence of the steam which it causes the vratei 
to emit, is it be thrown against the glass of the contaming vessel, 
H usually fuses it without causng a fracture, and has been known to 
pass through the glass, producing a perforation without any other 
-injury." 

V (g.) A ttrean^ of oofgen gat from a gaxomettr and hlotapipe, di- 
rected upon burning caarcoS, meltt and burnt many bodies, at iron, 
copper and tin, with brilliant appearances, and the evohition of much 
beat. 

fH.) EvrecT or the cohbostion. 

2^e oxygen gat is daninitked ; its ponderahle part eombinet teith 
the comiutttile oody, and both ehanget itt properttet and increatet iti 
ioeight ; one grain being gained m weight for eveir three cubic 
inches of gas absorbed. Combustibles, which like oil, candles, and 
charcoal, disappear while burning, are not destroyed ; tbej' have only 
passed off in gas, and other difiiised forms ; with proper care, ul 
the products can be collected again ; we can neither create nor an- 
nihilate an atom. 

(t.) Productt (^the combination. — They are either acids, alkahes, 
oxides or earths ; the three last may strictly be included under one 
head, but it is convenient to divide them. The process of combin- 
ing with oxygen, is called oxidation or oxidizenient, and the corres- 
ponding verb is oxidate or oxidixe.\ The oxides are sometimes dia- 
dnguislied by terms derived from dieir colors, but Dr. Thomson has 
introduced a nomenclature founded on the Greek numerals, as pro- 
toxide, deutoxide, tritoxide, viz. first, second, and third oxide, be. 
and tperoxide, for the oxide with the most oxygen. 

(y.) Water, at the pressure of 30 inches, and temperature 60°, if 
freed from air by bolhng, absorbs 3.5 cubic inches of oxygen gas, 
kx every 100 cubic inches of water; by pressure, the quantity is m- 



' I UM ■ ram rod ai 



OMzcdoyGoOgle 



creased, snd by gr^at presmire, water wiii absorb half its bulk, faiit 
without any change of pTCH)erties. 

6. Reiaiion to animal l^e. 

(a.) Oxygen e^)porta life eminently in retpiration, and 13 the only 
agent lliat ia adapted to this purpose ; but it is necessary ^t its 
great ener^ should be mitigated by dilution, as will be meiiABbBd 
again farther on. 

{b.) A bird will live fire or six times as long in a confined portion 
of oxygen gas, aa in the same volume of common air ; and several 
birds will lire a short time in oxygen gasi in which oibers have died ; 
each succesave one will, however, in genera], Uve a shorter time 
than its predecessor. 

" Count Morozzo placed a number of sparrotra, tne after another, 
HI a glass belt fiUed with common air, and inverted over water : — 

The first sparrow lived - - - - • 3h.0m. ^ 

The2d " " 3 * 

The 3d " « ... - - 1 

" The water rose in the vessel, eight Unes during the Bfe of the 
Gist ; four durii^ that of the seccMid, and the third produced no lib- 
sorption. He filled the same glass with oxygen gas, and repeated 
die experiment. 

The first qnirow lived 

The 3d « 

The 3d " 

The4lh " 

The 5th " 

The 6th " 

The 7th " 

The Bth " 

TheStfi " 

The iOth « 

He then put id two together, the one died in twenty minutes, but 
the other lived an hour longer." — Chaptal and Thomson. 

7. Rdaiion to diseate. — Oxygen gas is eminently salutary in some 
cases, especially in diseases of the thorax, in paralysis, general de- 
bility, &c.* 

* OzygeD gu, when respired in the human lungs, generally prodnc«* • Ma- 
nUoD of agreeable nnrmth about the reeioD of the chest, and Bomosiy thatftgy ez- 
perience a comfortable sensatioa OirDugh Ibe whole body. Chaptal relates lb« fid- 
lowing Inatance of its eSecta on a man in coiwumptioa. " Mr. De B." nys this 
writer, " was In the last stage of a conErioed pthiais. Eitremo weaknen, profuie 
sweats, and io short, every Bymptom annouacoil tlic approach of death. One 

of my friends, Mr. Dc P , put him ou a ronrse of Wtil air. The patient respir- 

•d it with delight, and asked for it with all (lie eagerness of an in&at at the breast 
Duriog tbo time Uiat he respireil it, he felt a comfortable heat which distributed It- 
self through all hisliiuba, HLi strength increased witli the greatest rapidity; and 



6«.33i». 


2 


10 


1 


so 


I 


10 





30 


n 


47 





27 



OXTGEN. ig] 

. 8. Efftct tm the color of the hlood.—M blood be suspended is 
oxygen gas or a^tated v\\h it, or even with conunoo air ia a ^va 
lube, it turns it of a bnlliiuit vcnnilion color; the nature of the 
change is to be mentioned hereafter more particularly ; we may how- 
ever remark at present, tba it acta on tho blood principally, by im- 



parting oxygen and detacliiii^ carbon. 
9, It iajom 



ijoujtd in more cominaliotu and in greater quantities than 
any element.* — It is found in tm atiOosphcrc, m all waters and walery 
flmds, and in all natural fluids,cxcept perhaps naptha and mercuiy. 
It exists in anunals and plajitsj'n stones, rocks, and metallic oxides, 
and in acids, salts, eanns, and <lkalic3 ; it possesses therefore the 
highest importance, and mthoul lowing this agent, we could under- 
stand littlo of the real consdtuuim if things. 

What has been called The mOcrn theory of chemistry, was 
occupied piincipally in unfolding tb agencies of oxygen, and diia 
« exposition still constitutes the most iinortant part of the science. 

10. Polarity. — It goes to the posite pole in the electro-galvanic 
circuit, and is merefore considered as Tectro-negative.f 

11. Itt combining weight. — Hydrogn being unity,! oxygen is 
represented by 8, because these are the-)ropoitions in which these 
elements exist in water. 

As its combining weight is " smaller th& that of most bodies, it b 
inferred that it approaches nearer than 4ey to the elementary <a 



In ail weeks, he vi 

■KtnAs; bnt tfier 1 , . ^„ 

cauna to the um of vital air, because Mr. Ds P» — ^ departed lor Pat^ b« 

died. 1 am ver; far, adds Mr. Chaptal, from belieTing tl^ the reapiration of vital 
air oaght to be conddercd as a specific, in casea of this DstVe. I ameveD Id doutit 
whether Ihli poweiiiil air ii perfectly adapted to nich iJ^inttutaDcaa ; but It iu- 
Bpires chaerfuJneM, renden the patieot haroy, and In deqiel(e case*, It k ceMainlj 
a meet precious remedy, which can epread flowers on (be btH^rs of the tomb, tai 
prepare us in the gentfeat manner for the last dreadful eflbrt ofjature." 

Tbenud relalea that of ttree men who bad been anSicateilty sulpboretted hy- 
drofen sas. In cleaning a privy, tno died almost im mediately, md the third baing 
almost dead, was made to respire oxygen gns from a bladder, anult rallied his pow- 
ers BO that he sat tip for a monieot, but«oon fell t>ack and died. \ a case related In 
be Am. Jour. Vol. XVI, p. 260, by Dr. Huse. of Cambridge, Mayland, there wm 
the moat complete success, a lavorlto bound that had been tW- se^ral hiwn com- 
pletaly drowned, havinr been perfectly restored (o life, and ETr^uaJlj to all his ^nc- 
''— -' '^■^e injection of ox --■--I'-i -.- - . .- 



liODa m coosequence oflhe injection of oxyeen gas into hie luogi ; t)^ very first tn- 

a-u i-.t- 1 oduced m shrill yelp from the animal. F« othir remarkaUe 

ur. Vol. 1, p. BS, and Dr. Thornton's Tartou* Raports in Til- 



loch's Philoe. Mag. 

* Umlting our estimate, of conne, to the bodies with which wo are acquainted. 

I Several respectable modem authors make thialact the fbundatknofanamnge- 
meat of chemical bodies. 



D„tiidD,Googlc 



siniple state ;"* thia might have been said with still greater truth, of 
carbon and bydrog^i. 

Renarki. 

Oxygen unites with every fdmple body but it has neither acid nor 
alkaliDe properties. It is tne agent in 9 conunoa cases of conibu»- 
tion, which in roost instances, is nothm/niore than rapid oxidation, 
with the emisdon of heat and tight ; 'nd a slow combination of ox- 
ygen often goes on without either j ommon iron rust is produced in 
that manner. 

Combustion and respiration hav the same efiect in vitiating the 
air ; the ail in which an animal hs died, will not support combus- 
tkm, and the air in which a comestible will not bum, will not sup- 
port animal life. 

Oxygen is involved in thechemical study of all bodies, ^ple 
and compound. The term oygen means strictly the ponderable 
part of oxygen gas ; the maf^al part is known only m combination ; 
It has never yet been isol^d so as to exhibit it separately ; in its 
gaseous form, it b combind with caloiic and light, and probably 
with eleclrici^. 

It appears to exist no 'here in nature, in a pure and disengaged 
state, and we always obl'u it for use by evolving it from one of its 
combinations. Healilij waves of vegetables, acted upon by the di- 
rect sun beams, throf it off incessandy into the atmosphere, and it 
is supposed to be a ptiicipal means of recruiting the waste of oxygen 
which arises from coiousUon, respiration, and ouer natural processes. 
In the dark, a difie^nt gas, the carbonic acid is said to be disengag- 
ed ; the subject wiJ be resumed in giving tlie history of that gas. 

It is fortunate tbt oxygen gas can be easily and abundantly ob- 
tained frum the ntive oxide of manganese, as there is scarcely any- 
other from whicl it could be obtained at all, and no other which 
could supply thr demands of chemistry and the arts. 

Nitre IS perbps the easiest resource for afibrding oxygen gas, but 
only tbe earlyportions are pure ; a little may be heated to low red- 
ness in a gunbarrel, but we should avoid the mouth, as tbe melted 
nitre is apt u boil up, congeal above the ignited portion of tbe tube, 
and thus aclng Ske a wad, by and by, after a cessadon, the gas causes 
an explosion, by which the hot nitre is driven about. Every thing 
connected witli the history of oxygen, is elegant, beaudful, and in- 
stmctivey without it there would be no beginning of animal life, nor 
any adequate means of producing and regulaling heat. 



•■Murr»y, Vd.I, p.40T. 



OMzcdoyGoOgle 



BEC. II. MITKOGEN OR AZOTE. — THE ATHOSFUERE. 

HITROOBN. 

1. Aome. — As it is ihe basis of nilric acid, it is now called nitro- 
nn ; its former oame was from n, a Greek privatire, and ^uii, 
Gfe, signifyiDK that which destroys life ; but the name is not distinc- 
tife, many oUier gases being azotic. 

2. Diaeovery — ^by Dr. Rutherford, at Edinburgh, 1772 ; Lavoi- 
aer first separated it from the atmosphere, in 1775, and Scheele, 
about the same time. 

3. J^ode of obtaining. 

(a.) Bum phosphorus in a floatiilg saucer or other earthen dish 
imaer a bell glass over water; the acid fumes are absorbed in half 
an hour by the water, and sooner, if agitated with it ; and nitrogen 
gas slightly phosphorized, remains. 

Solution of caustic potash, agitated with the gas in a bottle, quickly 
separates both the phosphoric acid, and a little carbonic acid viuai 
is sometimes mingled wiUi it. 

(&.) With a gentle heat, dilute nitric acid, sp. gr. 1.20, acting on 
lean muscle in a glass retort, evolves nitrogen. 

(c.) Iron filings and sulphur bemg mixed and moistened, and placed 
in a saucer under a beU glass ; the oxygen is absorbed b three or 
four days, and nitrogen remains. Other methods will he mentitMied 
farther on. 

4. Phtsicil and chehicai. pboperties, 

(a.) Traruparent, colot^esi, inodorotu, tasteUii, not temibly ab- 
lOrbed by water, 

(J.) Sp. gr. .9722, air being 1. — {Thornton.) 100 cub. in. weigh 
89,652 CTains. 

(c.) Its refractive power is very feeble. 

(d.) Comhinet with oxygen,' and forms several very important 
compounds — ^nitric acid, tbe nitrous acids, nitric oxide gas, and ni- 
trous oxide gas. 

Je.) JVo combination retuUi from a mere mixture of the oxygen 
nitrogen ; owing to the repelling power of caloric, they would 
probably remain forever in mixture, without change ; but they will 
tmite, it in the nascent state, or, if one of them is in that condition. 

d loith oxygen 6y eUctrtdty, nitrogen forms niuic acid. 
combvitwle in the common teme of thai word; 
y the approach of a candle to the mouth of a vessel 
contuning it, nor if previously mixed with oxygen gas. 

(A.) It u fatal to eot/^nution. — ^A burning match, candle, phos- 
phorus, or any bummg body is extinguished by immersion in this 
2S 



D,q,fzodbyGo(lg[e 



194 NITBOOEN. 

g&s ; even potassium, ahbough inteDsely heated by galvanism in nitro- 
gen, produces no change ; it is therefore not a supporter of combus- 
tion. 

(t.) Water deprived of its air hj boiling, absorbs about one and a 
half per cent, of this gas ; or, according to Dr. Ure, 100 volumes of 
water absorb about one of this gas ; Mr. Dalton states it at 3.5. 

6. Effects om animal life. 

(a.) Fatal, if breathed pure ; an animal immersed in it, immedi- 
ately dies. 

(o.) KHh by ruffocatian merely ; it is not directly noxious, and ex- 
erts no positively injurious influence on the lungs; an animal is drown- 
ed in it as it would be in water. 

6. COHFOSITION. 

fa.) Unknovm; but it is suspected to be compound ; Berzelius 
believes li to be an oside of an unknown base.* 

(J.) Contained in animal matter, and is equally abundant in her- 
bivorous and grammivorous, as in carnivorous animals. 

(c.) Plants do not generally contain it. 

(d.) Uia an element, according to the present state of our knowl- 
edge.f 

7. Importance and diffusion. 

(a.) It forms the basis of animal substances; of them it is the char- 
acteristic element, and it gives origin to the ammonia and the prus- 
sic acid, which are generated during their decomposition. 

(6.) /( « found in the cruciferou* planU, cabbage, mustard, Bic. ; 
in the fungous tribe, mushrooms, &C. and in all plants that putrefy 
with an animal odor. 

(c.) lit properties are interesting principally in combination; es- 
pecially in animal matter ; in the nitric compounds ; in amm(»iia, 
and with chlorine and iodine ; for an account of which, see the sections 
containing those subjects. 

8. Polarity. — /( resorts to the negative pok tn the eUctro-gal- 
vamc circuit, and is therefore considered as electro-poative. 

9. Its combining weight is 14, hydrogen being 1. 

Nitrogen is possessed rather of negative than of positive proper- 
ties, but in combination, it produces bodies of a highly active and in- 



■ ThomKm'a Aonals, II, 384. 

t When BDunonii, an tikoll nhicb contaim nilrogeD, (or eitber of ttsialti,) la gal- 
vanlied wl(b mercury, it cooverCi that melal loto an amalgam, nbidi cceatea a sus- 
picion Ibat its base ii metallic ; but Gay Luasac and Thenard say, (hat thU amalgam 
It immediately resolved into mercury, ammonJe, ard hydrogen, eTen when inter 
It aot pmsoDt. and Ihat, Uierefore, it ia composed of Ibose three subttancM ditectty 
united ; bnl, there may be metallic matter in bolb ammonia and hydrof;en, or in hj- 
drogen alone, beCKuse it U contained in ammonia, and it It pottible Ibal even nl- 
trogMi n*y be an oxide of hydrogen. 



OMzcdoyGoOgle 



teresting chtiracter ; some of the most powerful fiilniiDatiDg com- 
pounds contain it.* 

THE ATHOSPHEBE. 
PHT91CAL PBOPeRTlES. 

(a.) Trantparent, colorless, inodorous, only ilighily ahaorbed by 
water; & bad conductor of heal and of electricity ; the latter when ac- 
cumulated, passes throu|h the air in a spark, hut is difiused through 
a vacuum in the form of a luminous cloud. 

(b.) The azure color arid other hues in the atmosphere, are pro~ 
dvceaby reflected tight, 

(c.) As toe ascend, the iky grotes darker, and at a great height, 
the stars with the lustre of silver, are contrasted with a basis of black. 

(d.) Specific weight, 1. ; it is unity for all other aeriform fluids ; 
100 cubic inches, at the medium temperature and pressure, wei^ 
30.50 grains.f Compared with water, it is ^\^ oi the weight of 
that fluid. Gallileo ascertamed in 1640, that it has weight, and Tor- 
ric«Ui introduced the barometer tube in 1643. 

(e.) Absolute weight; at the ocean level, about fifteen pounds <Hi 
the square inch, equal to thirty four feet of water, and thirty inches of 
mercury. — Henry. 

(/.) As ve ascend, the heights bein^ in an aritimetieal ratio, the 
vm^U deereaaes in a geometrical raiw ; at three miles elevation, it 
sustains 15 inches of mercury; at six miles, 7.5 inches; atnine 
miles, 3i inches ; at fifteen miles, about 1 inch. — Id. 

Air is compressed in direct proportion to the force applied. Dou- 
ble the force will reduce it to half the volume ; double the force 
again, and its volume will be again reduced one half, that is, to one 
quartCT of its first volume, and so on. A force has beeti applied to 
it, equal to 110 atmospheres, and the law stated above, was found 
still to hold good.| 



* In the Eof. Jour. oT Sciance. Vol. XIX. IT, Hr. Fwidny bM given u ac- 
count of in logenioiu method ofdetecUng minute porlion) oT nltrogea, by the tat' 
matioD of ammonia. D ii a glara tube, four or five inches lon^, and one 
fourth of an inch in the bore. At a, there is Mune ilno toil j at fr, u 
[dace ofpotuh; ate, a piec« of turmeric paper molitened with pure wa- 
_X ter, at the loirer end, whicli ii two inches above the potash ; heat tha 
I lower«ndof the tabe only in the spirit lunp so as to melt the poUab, tent 
i almiMt inatintly, the moiitened paper will be iwddeaad, imUeatlns an al- 
kali, and it Is evident that II is'amnMola, becaose the cidar la dlacna^ad 
when flte paper la withdrairn, and the coloied pari laid oo the warm tube. 
Sea aaiid handled after l|;altian, yieldt anunema, wbMi i* dfcovered by Ibia IraM- 



OMzcdoyGoOglc 



Mr. Parkins states, that he has applied to it a pressure of $000" 
atmospheres, and he supposed that he had thus compressed it into a 
liquid, but as this liquid was permanent under the common pressure, 
it is probable it was water only.' As we descend below the surface of 
the earth, the density and pressure of the air continue to increase 
in the same ratio. " In very deep mines, water will not boil till heat- 
ed 3 or 4 degrees above 212°*. — Murray. 

ig.) The greater part of the atmosphere is withm three or four 
miles of the earth's surface. 

1A.) The phenomena of refraction indicate that the atmosphere is 
east forty or forty five mites high, 

[%.\ Dr. WoUaaton thinkt that the atmosphere hat limitt fixed by 
gramty, counteracdng the elasticity imparted by caloric, (Phil. Trans. 
1822,-p) and on account of the absence of refraction, (the heavenly 
bodies not being disturbed in their apparent position,) it is asserted 
that neither the sun nor Jupiter has any atmosphere ; hence the 
earth's atmosphere is not inaefiuitely divisible, and does not extend 
to those bodies, and therefore it is thought that its ultimate atoms 
must be indivi»ble, and this is regarded as a direct proof of the muh 
of the atomic theory, or, in other words, of the existence of indivisi- 
ble atoms or particles. 

{j.) Winds are produced by the ascent of rarefied air arising irosa 
the pressure of colder and heavier air towards the heated place. 
Thus, as ^ready stated, page 68, are produced tlie trade winds, 
monsoons, and land and sea breezes, and the irregular winds. 

{k.) The draught of a chimney is owing to atmospheric pressure; 
the column of air in the chimney rareGed by heat, is lighter than the 
adjacent c^umn of colder lur, and therefore ascends mm the pre- 
ponderance of the latter. 

(/.^ The refractive povier of the air it observed in the eleratioD 
of ships and other dejects near the horizon, and in the efiect aa the 
heavoily bodies in the same situatian, causing them to eme^e soonw 
when rising, and to linger later when setting. 

(fn.) It has been already stated that the higher regions of the at- 
mosphere are cold ; the lemperature in the lower regions, dimin- 
ishes at the rate of one degree for every three hundred feet. 

2. Cheiucai. properties. 

fa.J Air swpporti combustion, as every one knows. 

I J.) It generates atidity in vinous fluids. 

(c.) It oxidizes some of the tn^ais, at the comnMK) temperature, 
and moat of them at ignioon. 

■ It fi ct1ciilal«d, thkt al 4S bUm be)«w tba inriBca, tit would hkve tbe deiuHj 

t Far u «iMll«ot inalyiii of thla etuioui p*p«Ti tM Humy, Sth Edt. Ti^. I, 
p. tit. 



OMzcdoyGoOgle 



NITROaEN. 197 

(d.) Very great rarefaction dinimtshes, and even destroys iu pow- 
er of su^nrtiug combustioa. 

(e.) Great condensation does not increase the intensity of the com- 
bustion, although it is sustained for a longer time. 

(f.) Mixture with various gases diminishes it.* 

3. COKFOSITION, IN VOLUME, 80 KITROOEN, 30 OXYGEN »T 

WEIGHT, oxygen - - - 22.22 

nitrogen - - - 77.77 

100.00 very nearly .f 
This proportion of oxygen is undoubtedly that which is best adapt- 
ed to the support and comfort of human liie, and to the convenience 
of all the animal creation. Experiments have proved that Emimats 
compelled to breathe oxygen gas alone, soon become feverish Irom 
excess of stimulus, and hfe is eventually destroyed by the intense- 
ness of its own fiinctions ; just " as a candle bums brighter in oxygea 
gas, and is more quickly consumed, so in this gas, the ikme of life 
would be more vivid, but sooner burnt out." 

Most chemists have stated the composition of air at 21 percent, of 
oxygen. Dr. Henry states that he could never sausfy hunself wheth- 
er it was 20 or 21 ; Dr. Hare obtained very constantly 30.66, but 
20 corresponds with the theory of volumes, viz. 1 to 4, and also of 
definite proportions by weight, that is, 1 proportion of oxygen 8, to 
S of nitrogen 38. Still the greater number of chemists do not adm^ 
that the atmosphere is a chemical compound. 

4. Means of analysis. 

TTta/ are ntanerout ; every rubttance whick abstraeti oxygen tnth~ 
out reluming any thing, may be employed for thit purpoae. 

(a.) Phof^borus is eSectual, either by slow or rapid combustioii ; 
the latter is the most convenient process, and if we subtract ^^ °^ 
the volume on account of the vapor of phosphcwns dissolved, in the 
nitn^en, the result will be accurate. 

{b.) Iron filings and sulphur moistened, and standing in contact 
wiui a confined portion of air remove the oxygen.'^ 

(c.) Quicksilver heated in the confined air of a retort, fiuins 
oxide of mercury. 

{d.) Many otner thmgs to be mentioned in their place, produce ft 
similar effect ; see hydrogen, nitric oxide gas, hydro-sulphurets, fiic. 

In all these cases, oxygen is abs&acted and niirogeD gas is left, aad 
we know of nothing which will remove the latter gas, and leave the 



* Sae Henry, IDtbLon. Ed. Vol. I, p. S90. 

t TbmuoD'iPriDdplnorChemlMiy, Vol. I, p.lOO. t Tantsr. 

\ If tbey itiiid loo loDg, bfdro^ea miy be erolved btm lbs decMBpodlioa oT 



OMzcdoyGoOgle 



oxygen. The process of analysis of the air b called eudiometiy, 
the instrument, an eudiometer. 

ft. Condition or the elements of the athospbebe. 

(a.) It has been already ttaied, that mott chemistt mppoie. the at- 
motpnere to be a mixture of the tioo gate*. — In favor of this view, it 
may be said that there is not, as in most cases of chemical combi- 
DBtion, any change in volume ; 4 volumes of nitrogen and 1 of oxy- 
gen, formmg precisely 5 volumes of the mixture ; the refractive pow- 
er and tbe agency in combustion and respiration, is just what would 
arise from the operation of the mixed gases, and even water, in a de- 
gree, separates them, because ebullition expels from rain water moro 
man 28 per cent, of oxygen ;f the extended surface of the drops of 
rain being peculiarly favorable to the efficiency of a weak affinity ; 
also, a small quantity of air agitated widi a large quantigr of water, 
has all its oxygen absorbed, and but litde of its nitrogen. On the 
other hand, as tbe proportions, both by volume and weight, corres- 
pond with the theory of definite proportions ; as there is no inequah^ 
m the mixture arising from the diSerence in specific gravity, the at- 
mosphere being every where tlie same ;J even ifthe gases are not com- 
bined, the winds would tend gready to preserve, in equable mixture, 
aeriform fluids whose gravi^ is so nearly equal. 

(A,) Perhapt it it, rather, a feeble combinalion. — Analogous lo the 
many which exist between palpable substances where the properties 
are not altered. (Seep. 159.) There is no improbability that gases 
may be imited by a very feeble affinity, and a strong one would, in 
this case, be incompatible with the exigencies of animal and vegeta- 
ble life, and widi the demands of combustion. It is mdispensable 
that the atmosphere yield up its elements readily. 

6. Constancy of the proportions. 

(a.) 7^ never vary, except from the operation of limited load 
causes, such as combustion and respiration. The air which Gay 
Lussac brought down from 31.735 feet above tlie earth,^ contained 

* The teim dludei to [he health of (be itmoiphere, u it was nipposed lo be af- 
fected hjthe pniportitni of oxygen; the Greek panicle m, dgaifying well, and &<iif, 
be atmosphere, derived from Japlter, which in Greek ia Zivi, Oen. Aiit, lued br 
tba mtmonhBra. t Edio. Jour. No. 8, p. 211, quoted bf Dr. Turner. 

t Mr. DalMD'BTiewaofthe couBtltulion of the atmosphere and of nixed gaaea, ara 
oppOKd to this opinion. See Henry, Vol. I, p. 299, 10th Lou. Ed. In a vertical 
tube,orlDlwoviali tbu* conDectedby a tube, fiydK^eneai will In afew hoDnde- 
1 ._j — i.-i -i __j iscend, lo as lo mil with each other contrary to 



UTiy. n „ , ^ . 

B M eadly produced In them by eren alight vaiiationi of temperature. 
Bight be expected Wbror their mixture In the couraeof time. 

t At (bat beig^ an exbtnMed battle waa opened, filled with air, and then cloMd ; 
after bii deacent. It waa opened under water, which ruahed in and filled halfef it, 
Ihui prortngthB great rari^ of the air. 



D„tiidD,Googlc 



NITROGEN. 19g 

the regular propomon of osygen ; 90 does that obtained in the deepest 
miees ; that transported from Egypt and the African sands, uid uom 
Mont Blanc and CbiniboraKo, bad the same constitution. ** 

(&.) This contiancy, as hat been generally luppoted, is maintained 
by the agency of the vegetable king£>m. — See carbonic acid and veg- 
etables. Living vegetables in the sun's light, give out oxygen gas 
and decompose carbonic acid for Ibod ; in the night, they absorb 
oxygen and give out carbonic acid, but Priestley and Davy say, 
that they give out more oxygen than they consume, and therefore 
they purify the air. 

(c.) According to Prevost, 100 years would consume only fiVi'^ 
part of the weight of the oxygen in the atmosphere, making due allow- 
ance for all the consuming processes that are going on, and therefore 
if they had gone on even at the same rate from the creation of maUt 
the consumption would have been but the |-|y part, and doubtless it 
has not been half of that, that is, ji,. Some have supposed, that 
volcanic fires expel oxygen from various mineral bodies ; some, that 
nitrogen is absorbed into the bodies of animals, and o^ers, that by-* 
driven is obtained by plants from the decomposition of water ; all of 
which processes would either throw oxygen into the air, or tend to give 
it a preponderance, but none of these suggestions are proved to be true. 

7. AOENCT IN KESPIRATION. 

(a.) Animal life universally, in aU its form*, is siufained by the 
oxys-en of the air. 

(p.) The nitrogen appears to be merely a diluent,^ and [K>t to act 
except under certain peculiar circumstances, but it is not improbable 
that It answers some positive purpose in the animal economy, whose 
nature is not yet understood. 

(c.) The principal effect in respiration, appears to be the abstrac- 
tion of carbon from the blood. — See carbonic acid and respiration. 

7. There abe other bodibs in tbe atmosphere. 

(a.) Perhaps the only ones that are constant, are carbcHiic acid, 
about Tj'ji '31' siVi) ^^^ it never exceeds yj^ and aqueous vwor; 
riit ^y weight. Sauasure found carbonic acid at the lop of Mont 
Blanc, and it exists at every height hitherto attained, but the aque- 
ous vapor varies with the temperature ; air at 60° may contain 10 
grains of water to a cubic foot, and 4.5 at 43°, acid the quantity in- 
creases in a high ratio as the temperature is raised. On high mountains, 

' Mr. Faraday's analysis or air from the Arclic regfons, abows a decided and coo- 
itanl diflercLce belweeo it and Ihe aii of Landon, of at least 1.374 per cent. See 
A[^w«diK to Parry's 3d voyaKB. LiHid. Ed. p. 240. Ifo ciplaDatlon la gtren lo ac- 
count for Ihe cauie of thla diflerencc. but 1 bara lilUe doubt Ibat it Ii owins bi the 
n latitudes.— (CommunieatMf. J 
; it is certainly powible that it Bi 

re than thij in tbe air nhieb an aitembly of two 
hundred people had brealbed for more than two bonr*. 



D„tiidD,Googlc 



200 NITROOBV. 

it is veiy small ; caustic potash remained diy oo the peak of Ten- 
eriffe, at 12,176 feet above the sea. 

(b,\ Thete advenlitioiu thingt probably vary in their proportion. 

(c.) Baidea these, there are other bodiei. 

Kariout infiammabU gates, from marshes and stagnant waters, 
from putrefaction, kc. 

Anmonia, from the latter cause, and from some plants. 

Vaport and effiuma, from every volatile thing, from fluids, flowers, 
SiG^roducing odors and aroma. 

The matter of contagion. — ^It is toosubdleas yet for our processes, 
doubtless it is something aerial, more subtile than any gas yet known. 
It is combated successfully by chlorine, and to a degree, by acid gases. 

" Seguin examined the infectious air of a hospital, the odor of 
which was almost intolerable, and could discover no appreciable de- 
ficiency of oxygen, or other peculiarity of compowUon." — jfVrBer. 

Upon the usual estimation of 21 per cent, of oxygen in the air, its 
contents will he, including only those bodies whose existence has 
been proved to be constant. 

Mtrogen gas, 77.5 by measure, 75. 5& by wdght 

Oxygen gas, 21. " 23.32 " 

Aqueous vapor, 1.42 " 1.03 " 

Carbonic acid gas, ,08 " .10* " 

Dr. Prout discovered that the speci6c gravi^ of any gas is ob- 
tained by multiplying its combining weight by .555, which is half the 
sp. gr. of oxygen gas, air being 1. or 10. ; half the sp. gr. of oxygen 
is taken because half a volume of oxygen represents its combining 
power. The above rule applies to gases whose equivalents are es- 
timated with reference to oxygen as unity ; if hydrogen be unity, 
then multiply the equivalent by that scale, by .555 as before, and di- 
vide the product by 8, which is the combining weight of oxygen upon 
that scale. Or the same result will be obtained by multiplying the 
equivalent upon the hydrogen scale, by the number expressing the 
sp. gr. of hydrogen, namely, 0.0694. — Id. 
Remarks , 

If we could suppose our atmosphere to be removed, (the laws of 
heat and of pressure remaining as they now are,} another atmosphere 
would be immediately formed, consisting of aqueous vapor, and of 
every thing else that could, at the given temperature, assume the ae- 
riform condition ; this process would go on until the pressure react- 
ed with sufficient power to become mechanically a substitute for the 
present atmosphere. With similar physical laws, we cannot there- 
fore understand, how any of the heavenly bodies can be without at- 
mospheres, of some kind or other. 

* Murray, 1, 4S3. 



OMzcdoyGoOgle 



SEC. 111. — HYDROGEN — ^WATEB — UARE's BLOWPIPE. 



The name u derived Jrom ixSup and ymau, or /sivofMu, tign^j/ing 
the gmeratoT of xoaitr ; the popular name is inflainniBble air ; the 
miners call it wild fire. 

1. DiECOVEBI. 

It toMfirobabty knoum to the totdentt, but Mr. Caveodisb, A. D. 
1766, first proved it to be a distinct gas,* as Dr. Black had d<»ie 
nine years earlier with respect to carbonic acid gas, which was the . 
&st aeriform body, other than common air, whose existence was 
est^lished, and hydrogen was tbe second. f 

2. Pbocxss. 

It is always obtained, directly or indirectly, from tbe decompoa- 
tion of water. 

(a.) Fragments of zinc, or iron filings, or turnings, I part, sid- 
phuric acid 3 parts, water 5 or 6 pans ; add the water to the metiU ; 
uen the acid by separate portioDS, with intermediate agitation, the - 
vessel being held under a chimney, till the efiervescence comes (hi, 
when tbe gas must be received over water, in mverted vessels filled 
with that fluid. A glass retort, or a glass flask, furnished with a bem 
tube is all the apparatus that we need. A vessel of lead, or even of 
plate tin, will answer very well, but its opacity is an inconvenience. 
Muiiatic answers nearly as well as sulpburic in obtaining this gas, but 
the latter is much cheaper. 

(b.) It is obtiuned still purer, by the decomposition of water, by 
iron; see water. 

(c.) A purer gat. — Hydrogen gas as obtained by the above pro- 
cesses, is not quite pure ; if washed with a little lime water, or caustic 
potash, it is deprived of carbonic acid, and of sulphuretted hydrogen* 
which sometimes arises from sulphur in the zinc, and by being 
passed through alcohol, it loses its odor, which is probably owing to 
a volatile oiI,| supposed m be generated between the carbon in the 
metal and tbe hydrogen. A liule carburetted hydrogen is very apt 
to remab ; and to hare tbe gas absolutely pure, the zinc must be pre- 



* Phil. Tram. *. <», p. 144. 

t Carboalc idd ru wu diMOTered Id ITM or 1; hydragcD in ITM; nitrogea 
in im ; oiy^n and chlorine in 1TT4. Then Inportaat diacorariM laid tha found- 
■Ifon of Oie pneunudc ehdulMiy. 

% Which, on diluling (he ticohoi, mike* it* ippeirance, ailer i faw dmiri , upon 
dte lurfue of the wiler. Other auUiora auggesl thai anenicil particles derived 
Irmn tbe zinc, cauw the ■mcll, 

26 



DK;,lz=..,C00t^[c 



S03 HYDROGEN. 

nously distilled. It sometiineB has a little zmc or iron suspended 
or disBolved id it. 

3. Theobs op the pboczss. 

The acid is not altered, but the water is decomposed ; its oxygen 
passmg to the iron, converts it into an oxide, and its hydrogen is 
arolred ; the acid unites with the oxide of mm, and forms sulphate 
of iroQ, which appears in green crystals, as soon as the mixture is 
cold. How the add operates to favor the decompo9iti(»i is not a)- 
togedier clear.* 

4. Phtsical properties. 

(a.) It is colorless and transparent. As ciHnmonly obtained, it 
has a smell slightly fetid. If obtained over mercury, the odor is 
much diminished. It is scarcely absorbed by water, unless it has 
been treed from common sir, when 100 cubic inches of that fluid 
tike up 1^ inches of the gas ; with strong preesure the water absorbs 
one thu-d of its volume. 

(6.) /( refracts ligla more jaotoerfvJly than any gtu, agreeably to 
die general taw wiu respect to inflammable bodies; ratio 6.6 — air 
being l.-f 

(c.) Specific gravity 0.694, air being 1, just 16 times lighter than 
oxygen ; weight 3.1 16 grs. fiH- 100 cub. in. at the medium tempera- 
ture and pressure.! ^°^ cubic mch weighs but litde more than ^V 
of a grain, and fifty cubic inches but little more than (Hie grain ; 
it is the hghtest form of matter hitherto obtained. " It is about 
300,000 times lighter than m«cury, and 300,000 times li^iter thwi 
platma." — Hare. 



* Tht« UKd b> be cslled ■ cem of dlapoalue affiaity ; the &dd being diipoud to 
unite with (hsotfde odroa about to bt formed, by Ihe truurerof dieozygeaorthe 
wiUt to the Iron ; thi* eipluuthm ippeen lo be no more thin ««rtal, u the oxid* 
of irvn cunot eieil an aUrulifai before it it in eiietence ; but if, as suggeeted by 
Humy, the acid be Bupposad (o elert, Bimultaoeously, an attraction, both for tbe 
oxygsD of the water, and fnr Ihe Iron, it may thus aid the combination of the farmer 
with Ihe litter, end then tlie acid will cembina with the oiide of Itdd. Bnl tbera 
it DO evidence, eicepi that which ia aSbrded by ttia fact ia queation, that euch tn 
ftttracUon eiisti between the acid and the oiygea, aad the acid and the iroo. It ap- 
pear! to me bettAr to ray that we do not nndeistand it, and Id wait till we do, he- 
fan we attempt la eipfiin Ihe bet. The heal genenlwi by the action of Ihe add 
and water, wUf not explain the de compos tion, for tbe eold diluted acid will npldly 
•reive bydn^D gaa from icoa ; il siawa hot. it ia true, duriDR Ihe action, but the 
beat it not the cauM,lt is the effecl a? the action. There is another Iheoredcal diffi- 
culty in Ihla experiment. The rapid evolution of gtt, and eapecially of one whose 
eapaclly for heat exceeds that of all known bodiea, ought not, upon the received 
theory of heat, lo evolve that power; the mixture ought to grow cold. Again, tha 
etyitalllzatlon of the sulphate of iron ii rapid, and berini even beibre the mixtare 
la cold, md procaeda the more rapidly Ibo colder (he liquor growa ; but the evolu- 
tion of a *o)id frooi fluids ought to produce heat. 

I Henry, tdI. 1. p. 154. t Thoroaon. 



OMzcdoyGoOgle 



HYDBOGEH. 309 

(d. ) Balloons* are filled with it. The pnnciple of bdloons is reiy 
well exhibited by filling soap bubbles with hydrogen gas, or, better s^ll, 
with the explosive mixture of oxygeo and nydrc^en ; they will rise ia 
the atmosphere ; the former rapidly, the latter mwe quietly, and the 
flame of a candle will fire tbem as they pass ; in the latter caae there ia 
a con^derable explosion. The solution of soap should be strong, and 
used cold, and a metallic pipe will allow the bubbles to be more easily 
disengaged than one of clay. If a dish of strong soap water be blowii 
up full of bubbles of the mixed gases, it detonates powerfully, when fir- 
ed by throwing a burning match into it. A bladder, filled m the same 
manner, may be fired by piercing it with a sharp wire, fixed to a pole, 
and having, appended to die wire, a bunuog rag moistened with spirit 
of tuipeDtme. 

(e.) Mu»eal tonesf are produced when a small jet of this gas is 
burned in a glass or other tube. They are produced also by car- 
bonic oxide, coal gas, olefiant gas, and vapor of ether, burning in a 
jet ; the sounds are produced in bottles, flasks, and vials; and globes, 
from seven to two inches in diameter, give very low tones. The re- 

rt is considered by Mr. Faraday, agreeably to the views of Sir 
Davy, as only a continued explosion.^ 
5. Chemical Fropebties. 
{a.^ Hydrogen potsestes extetuivepowen of com- 
binatioH, as will be seen in the history of other bo* 
dies, especially of chlorine, iodine, sulphur, carbon, 
&c., and of animal and vegetable substances. 

(i.) Its INnAMHABILITT IS ITS HOST IMPOBT- 
ANT PmOPXHTT. 

(c.) A candle kindles a jar of it, but is itself ex>- 
tingmshed by immersion in the gas, and is relisted 
if the wick again touch the flame ; see the an- 
nexed figure of Dr. Hare, which needs no explans- 



'ForioiBe euriom tnd unurinit RMcaltHoiM reipectiD|; ttis pouiilt umi tihtJ- 
loont,Metlis Am. JoiK. Vd. XI,XlIaadXlIL Gay Lnanc, who uesnded till tka 
mercury Id the baromelen stood at II hiches, ascertained, that m>g;neUam and alec- 
trtcitj existed at that beigtit, in undlminwhed eDerzy. atid that the prapordan of 
oxygen and nltro^n. Has (he uune ■■ ■! the eurface oT the earth. 

I A jet of (tame from one of the ^zometen, p. IS4, ia adirdrably adiptod to insare 
the nicceH of this pleariog experiment By turaing the key, the jet In accurately 
regulated, and a great variety of tonea, from the most acute to the moat grare, u 
easllr produced by unng tubei of different materials, diBmetan, ItagOi and ihiek- 
DMa; hardly any lube comei ami>!>, and the same tube will give a variety of tonee. 
If moved up and down, while the flame is in tt, 

t Eng. Jour, of Science, No, 10. 



OMzcdoyGoOgle 



204 HYDROOEN. 

It is plab from this experiment, that 
hydrogen gas is a combustible, but not a 
supporter of combustion ; it bums where 
it is in contact with the air, but will not 
permit a candle to bum in it ; on the 
ctjntraiy, oxygen gas causes the candle 
to bum more rapidly, but, when it is 
withdrawn, the gas does not itself , bum. 

(d.) Hydrogen gas bums m jets and 
in many pleasing fornis, as is illustra- 
ted by the following 6gure. 

The bottle contains the materials to 
aSbrd the gas, which is kindled at the 
orifice of the tube, (the common air 
having been allowed previously to es- 
cape,) and the jet ia called the philo- 
sophic candle. The flame is very pale, 
but Dr. Hare, whose cut is annexed, 
ascertained, that the addition of one 
seventh of spirit of turpentine to the 
materials, would " obviate this defect." 

(e.) K mingled with common air, 5 or 6 volumes, and hydrogen 
gas 2, it explodes on contact with the flame of a candle. 

(/.) More violently vrith oxygen gaa 1 part, and hydrogen 2, by 
volume. This mixture should not be exploded in glass vessels, un- 
less in small quantities, and unless the glass is strong, and well an- 
nealed. It is better to use tubes of tin plate, or sheet copper ; a 
cylinder of the latter, closed at one end ;* or two cones joined at the 
base, and furnished with a mouth that can be, corked firmly, and with 
a touch hole, make a good discharging pistoh It is first filled widi 
water ; then with the mixed gases, and then kindled by a burning 
candle, or sulphur match, applied at the touch hote.f Hydrogen gas 
bums in volume with a yellowish flame, sometimes with points and 
sparks of red. 

(g.) Hydrogen gas, from its levity, escapes rapidly from vessels 
held with their mouths upward ; hut it remains a good while in con- 
tact with the air, without_escaping, if their mouths are in the reverse 



'Ifthli mixture be illowed lo egcape froni benealh wilur. the bubbles explode 
vialentlj' on louching a flama at the Burracc ; a gla.is veaaci should never be uied in 
thia experiment. 

< If the double CODS be filled nitb hydrogen and held with the mouth downward, 
lesTlng (he (ouch hole at the (op open, the gaa tvilt slowlji earap 



D„tiidD,Googlc 



HTDROOEN. S05 

postion. It may be turned upward into a vessel full of air, and wiU 
expel it, and uke its place. 

(A.) Suspend, out of the water of the pneumatic cistern, a tall nar- 
row jar, full of the gas, keeping a glass plate over its mouth, until it 
b fixed in its place : then withdraw the plate without agitation ; on 
putting a burning candle to the mouth,- a quarter of an bout after, 
the gas will take fire with the usual slight explosion, and will then 
continue to bum quietly away, thus proving that owing to its levity, 
the pressure of the atmosphere had kept it in its place. 

(t.) Reverse the experiment, by filling the same jar again with 
the same gas ; cover its mouth with the glass plate, and turn it up ; 
let an assistant hold a candle a foot above, and when the plate is 
withdrawn, the gas, now rapidly rising, will take fire as it is passing 
upward, and will exhibit a volume of flame in the air : the same 
pressure which in the former experiment kept it in its place now 
forces it to rise. 

6. Eftectb on animal life. 

It is hoiiUe to life, but not instantly fatal. 

(a.) The lungs may be Inflated with it a few times in succession, 
and it may be blown out without injury.* It produced in Mr. Mau- 
noir and Mr. Paul, at Geneva, a soft, shrill, and squeaking voice, 
when they attempted to speak, after breathing it. 

{b.) Frogs placed in hydrogen gas will suspend theu- respiration ; 
th^ have been known to do it for 3^ hours at a time. 

(c.) In mixture with oxygen, it may be substituted for the nitro- 
gen, and a respirable atmosphere might thus have been made ; but, 
the mixture would have been explosive, and the hydrogen would 
probably have separated from the oxygen m consequence of its levity. 

(d.) It kills by suffocation, merely or principally, as water does. 

(e.) It is not noxious to plants, and some, it is said, even absorb it. 

7. Nature o¥ btdrooen. 

It is an element in relation to our knowledge, and probably it is a 
real element. It is a simple combusdble. 

8. Its iuportance and diffusion. 

(a.) It is probably, next to oxygen, the most Important element ; 
it is exceedingly abundant, and its compounds meet us almost eveiy 
where. 

(6.) It exists in water, aitd aU fluids used by men and animals ^t 
drink or diluents. 



• Pililre de Rouer waa sccuslomed, not only to fill bis Innga with hydrogen gu, 
but tOMt fire to it as it issued from his mouth, where il formed a very curious jet 
of fiuDS. He also mixed pure hydnven saa irilh one ninth of common air, aod re- 
hired (he mixture aa uiuat ; " but i^en he attempted to set it oo fire, the cmise- 
qtience waa an eiplorioo so dreadful, that he imagined hia teeth mre all hlowa 



OMzcdoyGoOgle 



(c.) It it a amiHtveitt of all animai and vegetable bodiet, and is 
found in almost every part of them. 

(d.) It exists in mineral coal of every vaiiety, and most abundant- 
ly in die bituminous coal. 

9. Its combinmg weight, when it is made unity for other bodies, 
is of course expressed by 1 ; if oxygen be unity, ^en hydrogen will 
be .IS6. These are Dr. Thomson's numbers, but I have already 
stated the reasons why I prefer making hydrc^en anhy, as most wri- 
ters DOW do. 

10. PoLiaiTT. 

Hydrogen, in the galvanic circuit, resorts to ibe native pole, and 
is therefore con^dered as electro-positive. 

iSeff" rseulati^ reaervoiri, for hydrogen ond other gatet, are 
occasional^ conyenient ; the following are from Dr. Hare, beii^ im- 
proved upon the originiQ contrivance of Gay Lu^ac* 

" Suppose the glass jar 
without, to contain dihited 
sulphuric acid ; the invert- 
ed bell, within the jar, to 
contain some zinc, support- 
ed on a tray of copper, sus- 
pended by wires, of the 
same met^, from die neck 
of the beH. The cock be- 
ing open, when the bell is 
lowered into the position in 
which it is represented, the 
atmospheric air will escape 
and the acid, entering the 
cavity of the bell, will, by 
aid of the zinc, cause hy- 
drc^en gas to be copiously 
evolved. As soon as the 
cock is closed, the hydro- 
een expek the acid from the cavity of the bell j and consequendy, 
Its contact with the zinc is prevented, until another pordon of the 
gas b withdrawn. As soon as this is done, the acid re-enters the 
cavity of the bell, and the evolution of hydrogen b renewed, and 
continued, until again arrested, as in the firat bstance, by preventing 
the escape of the gas, and consequendy causing it to d^place the 
acid &om the interior of the beU, within which the zinc b suspended." 



* Dr. HaM italu thtt he uted id apporatua of thii kind, at WDUunibui^, Vi. 
li«fer*b*)Mdheardarth« of G>y Liuiae. It nill be scan &rther on, that meb t 
cmlrivince ii admirably adapted for obtaining light, iaBtantaneouBly, by tllowing 
the jet <rf dune to flow upon spongy piatinum. 



D„tiidD,Googlc 



WATER. 
Large leff-'regtUatwg re»iTVOvr,for Hydn^en. 



" This figure represents a self- 
regulating reservoir, for hydrogen 
gas ; it is constructed like mat 
described in the preceding arti- 
cle, excepting that it is about 50 
liines larger, and is made of lead 
instead of glass." 

" This reservoir is attached to 
the compound blowpipe, in or- 
der to fumbh hydrogen ; and 
may, of course, be used m all 
experiments, requiring a copious 
supply of that gas." 

On account of the extensive 
uses of oxygen and hydrogen 
gases, b a philosophical labora- 
tory, it is highly convenient, to 
have them ^ways on band, in 
large quantities ; and, of course, 
m sejwrate reservoirs, between 
which there is no posabiUty of 
communication. 



W ATEB, — STNTHE SIS. 

11. The combustion of htdrogen produces water, and pro- 
vided the gases be pure,* it produces nothing else. 

(a.) Bum a jet of hydrogen gas in a tall glass tube, and water, in 
viable drops, will soon line the tube. 

(&.) The same may be done in a bottle, 611ed either witli common 
air, or with oxygen gas. 

(c.) Or bum a double stream of the two gases, coming from 
distinct reservoirs, and mingling at the moment of exit. 

In these cases the receiver should be kept cold. 

(d.) If a bladder, iiimished with a stop cock, and a bent tube, be 
filled with hyHn^en gas, and the gas, kindled in a jet, be allowed 



* Sometiiiiei > liule nitric acid or nltrk oxUt, ia formed at the eipense of the nU 
troceo; or cvbonic icid, rrom carbu retted hjdrogeo, IbsM bciag accideiilal Im- 
puntlnia the gues. 



OMzcdoyGoOgle 



to burn uoder a jar of commoD air, or bener of oxygen gas, 
standing over mercury, there will be a rapid rise of the metal, and 
water will appear, first in vapor, and then in minute drops, lioing the 
interior of ihe jar. 

(e.) I find it perfecdyeasy to fill a large glass globe with oxygen 
gas, by allowing it to flow from a reservoir through a tube descend- 
mg to the bottom of the globe, and it is known when the latter is fuU 
by applying a taper, blown out, and having a litde fire on the wick, 
which is then rekindled at the mouth of the globe. This arrangement 
saves air-pump exhausUon. The hydrogen gas is then lighted in a 
jet, and allowed to flow from a gasometer as long as it is needed. 
Aa I employ the compound blow-pjpe in this experiment, it is easy 
(o let in either oxygen or hydrogen as it is needed, and thus the com- 
bustion is continued ai pleasure. The production of water in this 
mode is immediate and palpable. I subjom a figure of a beauutid but 
more complicated apparatus. 

Lavoitier't apparatus for the recomposition of water. 

" This apparatus con- 
sists of a glass globe, 
with a neck cemented 
into a brass cap, from 
which three tubes pro- 
ceed, severally com- 
municating widi an air 
pump, and n^th reser- 
voirs of oxygen and hy- 
drogen. It has also an 
isulated wire, for pro- 
ducing the inflamma- 
Uon oi a jet of hydrogen, 
by means of an elecuic 
spark. In order to put 
the apparatus into op- 
eration, die globe must 
be exhausted of air, and 
then supplied with oxy- 
gen to a cenain extent. 
In the next place, hy- 
drogen is to be aUowed 
to enter it in a jet, which 
is to be inflamed by an 
electric spark. As the 
oxygen is consumed, 
~ more is to he admitted." 



D,q,fzodbvGo(ig[e 



" I have emidoyed « wire ignited by ^alnniam, to indame the h^- 
diogea in this apparatus, and conceive it to be a much less precari- 
ous method than that of empbyiDg an electric machine, or electro- 
phorus."— flare. 

{/•) Oxygen and hfdrogm may be combined by explotum. — ^Thia 
happens of course, in all cases wnere they are ued together ; the 
product is lost, if the explosion finds vent into die opea air, but if 
confined to an eudiometer tube, over mercury, a Ihtle water wiD be 
obtained ; this ia never done except for the purposes of eudiometry, 
which will be mentioned agun. 

.te') Oxygen and hydrogen combine bypretture. — The two gases, 
wilTremain forever in mere mixture, at the common temperature 
and pressure, without combining ; but by sudden and violent com- 
pression in a syringe, they will explode, probably on account of the 
heat which is thus evolved, for " an equal degree of ccmdenaalionr 
slowly produced, has not the same effect." 

These gases combine slowly above the temperature of boiling mer- 
cuiT, and below that of glass when ignited, so as to be just visible 
in uie.dark. 

12. PboPOBTION of the EtMENTS. 

(a.) By volume, 2 hydrogen, and 1 oxygen, 

ITie combining weight, if there be one proporlioD of each, 
will be, oxygen, 8 > ■ . - , ■ ( 10.00 
« " hyLg;n^S°^""^^"°°'"^-{ 1.25 
Combumig weight of water, 9* or II. 2& 

(i.) Tm proportions of the elements m water, have been settfed 
after the most rigorous and often repeated analysis. The atomic hy- 
prthesis, and the theory of definite and muhiple proportions, sre bmlt 
upon the result of this analysis. All chemists take eidier oxygen or 
hydrogen for unity, and of late the weight of opinion and authority is 
erideotly in favor of hydrogen. 

WATEE AN1I.TSI8. 

1 . If water, m the state of steam, be passed over clean ignited iroo, 
in an iron, or in a luted glass or earthen tube, the mm absorbs the ox- 
reen, and hydrogen gas is obtained ; the weight of the hydrogen 
added to the increased weight of the iron equals that of the water de- 
composed. 2nc, antimony, and several other mewls will answer the 
same purpose more or less perfecdy. 

The couunoa wrangement for decompoang water is rejN^seiiled 
by the following figure from Dr. Hare. 

■ B i> tbe number Doir gsoanlly idopted. 



OMzcdoyGoOgle 



WATER. 
Steam deetmpoitd Ay ignittd iron. 



" Hainng iDm)cluced some turnings of iran or refuse card leetb, 
into a clean musket-barrel ; lute into one end of the barrel, the beak 
of a half pint glass retort, about half full of water. To the other 
end of the barrel, lute a flexible leaden tube. Uft the cover off the 
furnace, and place the barrel across ii, so that the part containing 
the iron turnbgs, may be exposed to the greatest heat. Throw into 
ihe furnace, a mixture of charcoal, and live coals ; the barrel will 
soon become white hot. In the interim, by means of a cbaufier of 
coals, the water being heated to ebullition, the steam is made to pass 
through the barrel in contact with the heated iron turnings." 

" Under these circumstances, the oxygen of the water unites with 
the iron, and the hydrogen escapes in die gaseous state through the 
flexible tube." For 1 grain of hydrogen evolved, the iron gains 8 grs. 

2. Galvanitm teitk gold or ptaiina vnret, gives an elegant remit; 
Ifae two gsses, in exact proportion, being obtained in mixture, if the 
two. wires are in the same tube ; if in different tubes communicating 
by a fluid or a wet fibrous solid, then the oxygen will be in one tube 
and the hydrogen in the other. If the wire is oxidable, hydrogen gas 
alone is obtained whUe the wire is in the meantime oxidized. 

3. Water is readily decomposed by ignited carbon, but the results 
are more complicated ; carbonic acid gas, carbonic oxide, and carbu- 
retted hydrogen gases being obtained. 



OMzcdoyGoOgle 



In this account of the composition of water, as a matter of conven- 
ience, the synthesis has been given before the analysis, while the ro- 
verse order would have seemed more natural. The synthesis was, 
however, first discovered, although in every instance of obtaining hy- 
drogen for the experiment, it must have been preceded by an actual, 
although unknown analysis of water. 

In 1776, Macquer and De la Fond, at Paris, burned « jet of hy- 
drogen, and observed that drops of water were condensed from it on 
a white China saucer, which was not soiled, and in the following 
year, a amilar experiment was made by Bucquet and Lavoisier, who 
could not sadsfy themselves as to what was produced, but ascertained 
that it was not carbonic acid. 

In the spring of 1781, Mr. Warldre and Dr. Priestley fired the' 
mixed gases, but the water produced was supposed to be accidental, 
or to have been merely deported from a state of suspension. 

In the summer of the same year, and afterwards, more particular- 
ly m 1783, Mr. Cavendish burned hydrogen on a large scale, and 
Siroved that the product was water ; an opinion which had been be- 
ore entertained by Mr. Watt, and communicated to Dr. Priestley 
and to De Luc. Mr. Cavendish, without any knowledge of Mr. 
Watt's opinion, had drawn the same conclusion, and is therefore the 
discoverer of the composition of water. Among the innumerable ex- 
periments which have confirmed this result, that made by Fourcroy 
and his companions, is worthy of particular commemoration ; the 
gases were kept burning more dian a week, 37500 cubic inches were 
consumed, and fifteen ounces of pure water were obtained precisely 
equal in weight to that of the gases employed. 

The decomposition of water was first efiected, understandingly, by 
Lavobier, in 17B3, by passing the steam of water over ignited mm ; 
the increase of weight in which, added to the weight of the hydrogen 
|;as obtained, precisely equalled that of the water decomposed. iW 
iron is found to be in the same condition as if it had been burned id 
oxygen gas or common air, it being a protoxide. 



WATER.— ITS PROPEaTlES. 



1 . Il ahtorhs spontaneously, a small qvantity of air, which escapes 
by the action of the air pump, or by boiling, and in the Torricellian 
vacuum. Water absorbs oxygen, rather than nitrogen from the air ; 
water thai has been exposed to the air, contains over 31 per cent, of 
oxygen ; this fits water to support the life of fishes, and gives it pun- 
gency and vivacity to the taste. The air obtained by ebullition from 
rain water, contains 32 per cent, of oxygen ; that from snow water 
34. S, but if the atmosphere be excluded during its melting, it is neat- 
ly free from air ; this is not contradictory, for during the free:ung of 
water, the air is expelled, and is agaih absorbed when itmelts. When 



OMzcdoyGoOgle 



water absorbs any other gas, the air which it contains is more or less ex- 
pelled ; hence, gases confined over water, are soon cootaminated in 
this manner, u bcHling water, the first pcHtions expelled contain die 
most oxygen ; the nitrogen comes idotg tardily, and, if after boilii^ 
and air pump exhaustioo have ceased to evolve eny more gas, electri- 
cal discnai^es be passed dirough water, more nitn^en will be evolved 
aloi^ with oxygen and hydn^n, proceeding &om the decoo^xwtioa 
of the water. 

3. BoStd water, dbwrbt a portion of txtry gat.* — ^The quanti^ 
abs(»bed is increased by pressure and by cold, and the facts will be 
more pardcularly stated in giving the history of each particular gas. 

3. Water tUways exittt in the atmotphere, in the dnett vxather. 
(a.) Deliquescent substances attract it, as potash, sulphuric acid, 

ana muriate of lime. 

(b.) Cold bodies omdense it, in dew or boar finsl. 

(c.) Poroui bodies absorb water from the air. — Diy earth, dry oat 
meal, and dry metallic Blings, afford examples. 

4. Water, bff combination becomes ii>Ita.— This is seen in the hy- 
drated ailcahes, potash and soda, in the hydrated oxides, and in many 
crystals, especially artificial ones ; when crystals contain water, it is 
always in definite quantity. 

5. Water, ditiolves a great vanetj/ of bodies, more, pTobahly, than 
any other fluid — acids, aStalies, salts, gum, sugar, alcohol, 6ic. 

It is the most general solvent to bnng sub^ances together, under 
such (urcumstaoces as to promote the various chemical processes of 
nature, and as it alters tbeu' properties very Utile, it is favorable to 
chemical acdon by bringine; many solids into a state of fiuidity. But 
in some cases, its cheniicaf action is highly important. 

€. 'T%e sotvtion of a solid in toater generally produces cM.'— 
Bi-carb(Hiate of potash and caustic potash crystaUized, produce cold ; 
but caustic potash that has been recendy ignited, or which after thu 
operation has not again absorbed water, dissolves with a rise ol tem- 
perature. 

7. ^ir is disengaged during the sohttion of bodies in water. — ^It is 
panly contained in the crevices of the bodies, and partly dissolved in 
the water. 

8. Water, when pure, is perfecdy transparent, tasteless, colorless, 
and inodorous. According to Professor Robinson, a cubic foot of 
vrater at the temperature of 65°, weighs 99S.74f oz. Avoirdupois, or 
63.42 lbs. A cubic inch at 60°, and at 30 inches pressure, weighs 
253.525 grains. Pure Or distilled water, at the temperature of 60°, 
is always taken as the unit, when we speak of the specific gravity of 
other bodies. 



* See a libki Henry, Vol. I, p. 229. I In rauad numben 1000. ' 



OMzcdoyGoOgle 



WATEi;, 313 

The refractive power of water is very high, owing, as is supposed, 
to the hydrogen which it contains. By a vigorous stroke b a sjiioge, 
water emits a QaA of light. — Thenara, 

Water has generally been regarded as incompressible, but Mr. Per- 
kins applied to it a force of 3000 atmospheres, and stated the com- 
I^ession at -^j, but Prof. Oersted* justty coo^ders this estimate as far 
too great. It would appear from a note by the late Prof. Fisher,f 
of Yale College, that the subject is not quite new, and Mr. Canton, 
so tar bach as 1764, ascertained that water expands ti^t V^^t ^ 
the removal of the pressure of the atmosphere, and that an addiDwial 
atmosphere reduces its volume in an equal degree. No natural water 
b quite pure ; it always holds saline and earthy matters dissolved bl- 
ades gases ; rain or snow water obtained away from population, as on 
a mountain, is the purest. It is obtained pure by distilhttiiNi, espe- 
cially in vessels of gold, silver, m platinum. INstdled water is indis- 
pensable in aU accurate chemical operations. 

8. Utility of water. — It is far more abundant than all other fiuids ; 
it is iodispensaole to animal and vegetable life, and no other fluid 
would answer the same purposes. 

Water enters into the composition of all the sdids and fluids which 
we consume for food and diink ; it imparts that humidity to the afr 
which in breathing moderates animal heat ; it afibrds by its pressure 
and motion, the means of great mechanical operations, and it facilitates 
commerce and friendlr communication between nations. It is ne- 
cessary that its properties'i^uld be negadve, or it would be injurious. 
Oaxometerfor oxygen or any gat not abtorbed by water. — Dr. Rire. 

"The engraving on p. 314, represents a section of the gazometer 
for oxygen, which is capable of holding between five and six cubic 
feet of gas. It is placed in the cellar beneath the lecture room. The 
wooden tub, V, is necessarily kept nearly full of water. The cylin- 
drical vessel, T, of tinned iron, is inverted in the tub, and suspended 
and counterp(Hsed, by the rope and weight, in such manner, as to re- 
ceive amr gas which may proceed from the orifice of the pipe, in its 
axis. ^is pipe passing, by means of a water-QEht juncture, through 
the bottom of die tub, rises through the floor, 17 >3 furnished with a 
cock at C, and terminates in a gallows screw. This is fixed in a 
cavity made in the plank forming the table of the lecture room, in the 
vicim^ of the pneumatic cistern. Hence by means of it, and a lead- 
en pipe soldered to a brass knob, properly perforated, a communica- 
tioD may be established between the cavity of the gazometer, and any 
odier vessel, for the purpose either of introducing or withdrawing the 
gas. The counter-weight being made heavier than the vessel, by 
appending additional weight to the ring, K, the gas may be sucked 

* Ellin. Jour. No. 12, p. 301, t Am. Joar. ToL 111, p. UT. 



OMzcdoyGoOt^IC 



214 WATER. 

in from a bell glass, (^tualed over the pneumatic cistern,) as fast 
as it eDters the bell, from the generating apparatus." 

" Gazometers which contain 40 or 50,000 cubic feet, have been 
constructed upon this principle, for holding the gas from oil or coal." 



.yGcxigle 



Deutoxide ofHydrogin. 

1. HisTOKT. — Until 1816, water wasbelieved to be the only com- 
pound of hydrt^n and oxygen ; but in that year, Thenard published 
m the Transactions of the Academy of Sciences of Paris," an ac- 
count of this singular substance, and hitherto little has been added 
to the facts stated m the original memoirs by this celebrated chemist. 

2. PBEPABATiON.f — From the peroxide of barium, by the actiui 
of diluted muriatic acid, aid then of sulphuric acid, both, a number 
of times repeated ; followed by that of »ilphate of ^rer, and then by 



• TbcMrd'i Chem, 4th Ed. Vol, V, p. 41. 

t The pHncipil Sieftot thi9 complicnted procen, which the itudeot will not b« ex- 
pected fully to undenland uulil farther adrsnced, are lu followi : — 

1. Frcpire nitr>ta of baryta; Ihl* may be done by decompoilng the iiilphUa c^ 
barytae hy ignillDa It with charcoal, by which It ii turned Into a Bulphnret; (hi* b 
decompoied evcD in in Iron vemel by nitric acid, and any iron that is taken UD Is 
predpllaled by baryta, and the Ditrate of baryta ia then crystallized. 

2. Tbfl nitrate li decompoaed by IgnitioD in a pore'' * "' 

trateba withdrawn from the fire In proper time, it w 
deutozlde, but*) it U commonly oxygenized hy pa»ing the dry pure oiysen ni over 
the Igniled baryta coniiiinei^ in a luted i;1bm tube ; the oxygen la rapidly abnrbetf, 
and we obtain ue dtntoilda or peroxide of barium ; It I* tbia very paitlon ofDiyKQ 
thui abearbed, wfaieh ii to be tranalerred to water or ralber to it> hydrogen, and ft U 
doDB In the following manner. 

It, Take water, >ix or seven ounces, and strong muriatie acid luffieient to dianire 
SW graina of bliyt*, and add 18S graini of powdered peroxide of barium ; the ab- 
lution ii wilhont efler*eacence, hecauae, although the itcid cambinei only nilh the 
Erotoiide, the excess of oxygen is not disengaged, but unilei to the water or to the 
ydrogcD «f the water ; the water tbusbccomesoxygenlzed, but InlooimaU a pro- 
portion to be obwrv«d. 

4. Sulphuric add bDOWtMlded,justeQough to precipitate Ihebar7les,and Ihemari' 
■tIcaeldtathusUberated, and is again ready loactapDnmoreoftbeperoilde, whlehi 
•s befi>re. Is now added In the proportion of 136 grains; this la diaaolved; the excest 
of oxygen li added to the water; tbe barytoaia again precipitated byiulphuric adi^ 
and the iosolnble sulphate !■ leparated by the filter; thus tbe proceaa ii repeateda 
stiffldent number of times, until about three oances of the peroxide hiTe been en- 
ployed, when the liquid will contain fitnn twenty fire to thirty times Its Tolumeof 
oxygen gas. 

B. The sohitlon is DOW a mixture of muriate of baryta wllb oxygenized water, nd 
to remove the salt, its acid is fint aeparated by eulphate ofallTer, which (brms nu- 
riale ofrilrer, and liberates the sulphuric acid, which, in iti turn, Is removed bya>- 
lid baryta in powder and by filtration. 

6. Tbe aDlutian ia now the oxygenized water, or. ai it is more properly ealled.the 
peroxide of hydn^n, but still containlDg more water than Is necessary for its nitf 
tloD ; thia isrsmoved by the air pump; the ve!«el containing the peroxide of hydro- 

En ig placed la snolher about two tfalrda full of sulphuric acid, and the vacuiiniB 
ned over it, which occa^na the evaporation of the water, and leaves eventiHlly 
nothing but the peroxide, which, if continued in the vacuum, is finally, but verji 
■lowly TolatHlzed unchanged. Theoard nys, " an boatde deux Joura la liqueur 
contlendra pent-Mre deux cent clnquante fbia soa volume d'oxygene." Tbe per- 
oxide, as thus obtained, has the apeciGc gravity of 1.4fiS, and It did not grow any 
denser \>y continued exposure to the vacuum, although It diminished eouldaablj 
In quantity. 

MhiDle u (hli abridged statement may appear. Chore are many details neoMary 
to success, for which Tcawise most he had to Thenard'* own aceaoDt in his Cben^ 
btry, or In the Ann. da Chin, el de Phys. Vob. Till, IX and X ; or Ann. if Phik. 
Vob. XIII and XIV. 

■ The clause in parautbeais eomoiitaiealed hy Dr. J. Torrey. 



, DMz.dDyG00t^[c 



baryta, and finallv by coocentraticn br air pump exhaustkiD, uded 
by the affinity of the vapor of water for snlpbiiric acid. 

3. Profxxties. 

(a.) Theu are remarJuAly different fron thote of water. — ^Tha 
fluid is colorless and inodorous ; aestroys gradually the color of litmus 
and turmeric paper ;* is somewhat corroaive to the skjo, bleaches it, 
and if abundandy ap[^ed, destroys it. It bleaches the ttx^e, 
makes it tingle, and gives a peculiar taste resembling that of metallic 
solutions. 

(&.) Although wmch more fixed than water, it may be entirely evap- 
orated in a vaemtm, vdtbout decomposition. At 59° Fahr. it is da- 
composed into water and oxygen gas. It can therefore be scarcely 
preserved except surrounded by ice ; but it remained fliud at every 
degree of cold applied to it. 

(e.) At 212°, tt it decoa^oied ecmlonvelif, oxygen gas being lib- 
erated, and therefore if we would deccMnpose it by heat, it must be 
fweviously diluted. Difiiise day light has no e^ct upon it, and di- 
rect solar light very Utde. 

(d.) It it decompoted by nearh/ aU the metdt, and by molt of their 
tmoet, these subs^ces being in a state of minute division. 

(e.) Hiote that pouetfidly attraa ox^ea combine mth a portion 
i^Uf such are potasmum, sodium, arsenic, mnc, he. and in uiis way 
several metallic protoxides become peroxides, and on the same prin- 
ciple bydriodic acid, sulphurous add and sulphuretted hydrogen, at- 
tract oxygen from this miid and bring it to the condition of water. 

{f.) Oxide of tilverf decompotet the oxygemzed xeater with ex- 
plotion. — This happens if the fluid falls on the folver, drop by drop, 
uid if the place be dark, light is seen. 

Jr.) Several other peraxidet decompoie thit oxygenized con^toand. 
ucb are those of manganese, cobalt, lead, platinum, gold, iridium, 
rhodium, and palladium ; the oxygen of the water is always disen- 
gaged, and sometimes tiiat of the oxide. The decompomtion is 
complete and instantaneous, and sometimes ignition is produced in 
the glass tube containing the materials. 



mixture wlthit,ofinaiiUqDuitltyof ozrKeiuuil water. 

t Id tha Am. Jour. Vol. XVII, p. 84, Dr. Ed. W. F»ut bu niggeited, Ihtt thl« 
«ariMu phenomaDDn of the dMompotitkHi of oxyKeniied water by oxide of iUveri 



duMl. Tbehjrdn^oD bnW lem imnitjp for the exeeu of oxy^eo, Hun (he metal 
tut, Ae Hqnid beeraieg iie|;>flve, thuj icUdk the pmrt of the (x^iper plate of a bat- 
tery, white the metal becomes posftiTe, mppijiog the place of the zinc plate. The 
Uqaidlf thus reaolved Into water and oiygeo. If the metal be very oxjrdable. It* 
retain* die oxygen, which ii evolved If gold, platlaa, fcc be tued. We need acarce- 
ly relra to die wirea of a battery, for a parallel caie. 

*'WheD the penizide of hydn^eo come* in Mntad with the oiide id' iil*er, the 
ongeo eacapea from both, and the latter i* reduced to ttie metallic atate." For a 
(iifler ac«ount, aee Qie paper of Dr. Fuul. 



OMzcdoyGoOgle 



WiTCti. Hi 

tomipiumd wtmrt pamaneKti if the bqud hu beeun m sSwpmu b^ 
beat, a drop of the MroDger acids, and even of toe principal renta- 
ble acida, will came it to ceaae, and the addiMii of an alkali wUl 
cause (be tdeci to be renewed^ 

(i.) Peroxide of hydrogen it dacM^ottd ly heating air^vihf lib 
diluted solution: tta compofiitioo as ascenainfld by it» diacDverer, 
Tbenard, is hydrogen 1 proportion and oxygen 2=16, end 1 7 is thwa- 
fore its represaitBtve number. From ha great specific ^rity, it 
sinks in common water as sulphuric acid does, although it Inia s groat 
affinity for that fluid. 

Thenard suggested an apjdicatioa of it do remove dark mota from 
pictures, in which wlute lead paint had become tarnished by sulphured 
ted hydrogen : this it effected instantly by the agency tii the Wtygen of 
the oxygenized water, which converted ibe sulphmet into & suti^iMe.' 

Many other particulars might be added respecting (bia curious eoio- 
pound, but ihey would be iaconsisteot with the extent of this work. 
There does not a|^ear any postive pnx^tbat die combioetiffii of the 
oxygen is with the bydrogen directlyi rather than with tbe entire watctr^ 
but Qie fact that the oxygen bears a multiple relatiwi to that cmiaitied 
in water, afiRirds a strong presumptive proc^; perhaps a salia&Btory 
one, in support c^ die former view. 

EUDIOHHTar BT MTintOOEN. 

Eudionietry has been already mentioned in giving the history of 
the atmosphere, and it remains to describe, as fast as we come to 
them, the action of the various substances that (^rate to remove 
oxygen from the air, or from any mixture of gjases. Hydrogen i«- 
(Mie of the most efiectual. 

1. Modet of i^tplication. 

(a.) In a conmon eudiometer («4e-— This land of tube is ^-i 
made very stout, as m the annexed figure : the glass is well t^Vfi 
annealed, its mouth is usually trumpet shaped, it is graduated ll 11 
and furnished, towards the top, with two wh-es, cemented mto II It 
the glass, and approaching, but not touching each other. In || {| 
this manner, an electric spark is easily ntade to pass through II It 
the mixed oxygen and hydrogen gases, and an explosion and J| IL 
diminution of vokime foUow. 

(6.) Dr. XJr^s ettdiometer, of which a figure is 
annexed, is very simple. It is a syphon tube, clos-/ 
ed at one end, and with pktlinura wires bermeticalhr 
inserted : it is of course graduated i its legs are boUi* 
from six to rone inches long, and the interior diame-^ 
ter is from two to fiwr tenths c^ an inch i it wdl receive 
■afely one fourth of an inch of the mixed oxygen 
and bydrogen gases, and nearly an equal volume of 
defiant gas mixture : the water or mercury in the _ 



OMzcdoyGoOgle 



S18 



WATEB. 



' bend a brou^t lo the same level, and two inches or more of air is 
left in the leg, which is held in the hand. The thumb is pressed 
firmly upon the orifice, and the spark taken eidier through the hand 
as a part of the conducting substance, or by a wire : the elastic spring 
of the confined air prevents all danger of explosion, (»dy a very slight 
pressure being felt at the moment. 

(c.) VoUa't eudiometer, — ^I give, from 
Dr. Hare, a figure of this elegant, but 
expensive, and rather complicated in- 
strument, which is now little used, and I 
therefore omit the detailed description, 
which may be found in Dr. Hare's Com- 
pendium. 

A and G are graduated glass tubes: 
each division of Lbe 200 parts of A cor- 
responding to 10 of G, which holds 10 
measures of A. C is a funnel-shaped 
foot, with a stop cock and cap for intro- 
ducing gas from the measure, k, which 
is furnished with a slide so as to give al- 
ways the same measure. I is an insu- 
lated electrical conductor. F, a basin 
shaped cap for pouring in water, and to 
admit of introducing G, air tight, with a 
finger on the orifice, so that (F being 
filled with water,) it may be screwed to 
its place, or removed fi'ora it without loss 
of Its contents. There is of course a 
communication through B and E, and 
the whole apparatus having been first 
filled with water, the mixed ^ases are 
introduced ; the spark taken ; B opened 
under water to ascertain the diminuUon, 
and the residual gas bemg let up into G 
is there accurately measured. 

{d.) Dr. Hare't eudiometer.~— To 
produce the explosion of the gases, this 
gentleman has availed himself of the ig- 
nition produced by a small calorimotor, 
in a slender platinum wire, forming a part of the connexion in the 
interior of the eudiometer tubes: he measures the gas conveniently 
and accurately, by a graduated rod, sliding air tight ui the instrumem. 




OMzcdoyGoOgle 



and also by some separate instruments called volumeters, and sliding 
rod gas measures. To one of his eudiometers a barometer gage is 
attached, by which the amount of absorption is accurately ascertain- 
ed. The ignitioD of the platinum by the calorimotor, for the purpose 
of inflaming the gases, is an elegant and novel method of operating ; 
the various modes of measm^g the gases are ingenious and accur- 
ate, and the detailed description of all the instrumenls and operations 
may be found in Dr. Hare's Compenditun, and in the Am. Journal. 
We subjoin the figure, and an abridged descriptiDn of the simpler 
of these eudiometers. 



Hydro-Oxygen Eudiometer of Dr. Hare. 




ff w 

W W Two brass wires passing through the socket S, and appear-, 
ing within the glass detonating lube G, where they are connected at 
the top by a soldered arc of platina wire, visible in the drawing. 
One of the brass wires is soldered to the socket. The other is fast- 
ened by means of a collar of leathers, packed by a screw, so that it 
has no metallic communication with the other wire, unless through 
the filament of platinum, which is called the igniting wire. 

At A is a capillary orifice in the glass tube, which is opened and 
closed by the lever and spring, seen in the drawing, and it may be 
guarded by a gallows screw, in the iron staple A A, which may be ap- 
pended to the instrument by pivots at S, and the opposite point, and 
may be dropped out of the way when the eudiometer is to be charged. 

R The sliding rod, is acurately graduated to about 160°, and to 
diminish the chance of leakage, a stop cock may be interposed be- 
tween the sUding rod and the detonating tube. 

B represents a detonating tube, to be discharged by an electric 
spark ; it may be screwed into the socket S, instead of the tube G, 



DK;,lz=..,C00t^[c 



"nie iliiHnr rod eodiooMter bdn^ sseenunsd to bs dgbt, ia filM 
with wster, free from air btifabtea, ihe rod being iotrodueed to ttt 
bik, aod tbe raive at A beng open, the rod ii drawn out aod ifaa 
kutnnneDt being in the Mmosphere, common air of course ejH 
ters, or the eudiometer is placed under a bell glass, and tfae ffSr 
fs, either MiccesKvelf^i or previoudy mixed in the proper proper' 
tionf, are then introduced by sucbon of the graduated rod A, aod 
the wire* W W being applied to the two ptxes of a calorifnoter, 
u the moment in action, the exploflion takes j^ee. The valve be- 
ing opened under water, this fluid enters to supply the [dace of the 
gases consumed, and any residuary air being excluded by the shdieg 
rod, the portion of the latter remaining without, will, by the gradua- 
tion, indicate the deficit, which is to be apportioned by me rules given 
below } that is, § of the dimicudon is hydrogen, and i is oxygen.* 

For the purpose of the general student, any mode in which the 
ntiiced gases can be exploded cc»iveniently and the diminution easily 
Mcertained, will answer every valuable purpose, 

USE OF THE HTDRO-OXTGEN ECDIOKETER. 

if we mix accurately 3 volumea of hydrogen vnth 1 of oxygm, 
tad inflame then) in any of the above named euditxneters, provided 
(he gases are pure, there will be a total condensation, 

A^ it is however rare that the gases are quite pure, it is often best 
to emplfM' an excess of that gas which is used to detect the other. 
In examming oxygen gas, if we t^ke three volumes of hydrogen, 
one third of the diminution being oxygen, it will not injure the result} 
V diere should be a residuum. If 100 measures of oxygen gas are 
fired with 300 hydrogen, and there is a residuum of 130, it follows 
ibat 370 have disappeared, and 90 is one third of this, and of course 
it appears that there is 10 per cent, of foreign gas, it may be nitrogen, 
or carbonic acid ; for there is an excess of 100 of hydrogen. 

Suppose, on the other hand, that we fire equal measures of oxy- 
sen and hydrogen, say 100 of each) if the 200 are reduced to 80, 
the dirabution will have been 120, and two thirds of this, that is 80, 
is owing to hydrogen ; it follows of course, that there b m the hy- 
drogen 20 per cent of foreign gas most probably nitrogen. — &Kry, 

If 100 measures of common air are mingled with 50 of hydrogen, 
and exfdoded, the 60 volumes will generaUy be reduced to 87, giv- 
ing a diminution of 63 measures, one third of which, 31, is the pro- 
portion of oxygen usually assigned ta the atmosphere, 

* Tha ftcQlw of Ill« CBloriiDDloi used id then viperimonta will b« giveo under 
tbe y^aA of GatriDiiiii. For * ntra ^Milad Mcaunt, ind vulaiM pu<icuhn to fs- 
MN tmeun/tf, »m Dr. Hwa'i Cowfendiuv. 

NoIMbk In iVMeMloii af ibo irood cuu«fth« luniin^teT gtge ludipEpet^r, vnd 
pf Hm ilidliu rod lu mruun, I have been obliged to obiU an account of llMie In- 
(tnunapts wUeh I bad prtparsd. 



DK;,lz=..,C00g[e 



Dr. Tbomon (flnt Prbciplea,) smployed 43 vdiunes of by- 
&mf,ea ta 100 of tir, and alway^a obudned a. reductm of 60, one 
limd of wUch, 30, cotreapondi with the theory of volumes, and alto 
of multiple proportions by weight, and granting that atmospherical 
air b « feeUe compound, this would appear to be, hi ail fnvibsbili^, 
the mie propoitioD ; and if ibis is the true proportion, ibis fact in lit 
turn itreoglheos very much the opinion that in the atmosphere, the 
dmnentt are not mertdy mixed, but slightly combined. 

The electric sperk will no long^ cause explosion in the mixture 
of 2 ToluODes of common air, and X of hydrogen gas, when there are 
13 parts of commoa air, or 9 of hydrogen added to the mixture, or 
wboi it is rarefied 16 times by dinunudon of pressure, or 6 tunes by 
heat. Oxygen and hydrogen gases in the proportion to form water, 
if rarefied mechanic^ 18 times, will not explode by electricity ; 
according m Sir H. Davy, rarefactioo by heat causes the mixed 
gases to explode more readUy by the temperauire of ignition. 

In the analysis of atmospheric air by hydrogen gas, 5 volumes 
of air should be sufficient for 3 of hydrogen ; but it is better t» 
employ a small excess ; here, as before, one third of tbe dimi- 
nution will be owing b) oxygen. Dr. Hare says, that in a great 
number of experiments, performed by means of his instruments, be 
obtamed rery constantly 20.66 as the quandty of oxygen m 100 
parts of tbe air, and that in twenty experiments, the greatest discwd- 
ancedid not amount to yjVj >° ^^ measures of air. — Comp, 

ACTION OF FLATtimif. 

(a.) A very effectual eudiometer was unexpectedly [vesenied u> 
us by a discoTcry of Dobereiner, of Jena. The muriate of platinum 
uid ammonia, when igaited, leaves the metal in the state ol spon^ 
platinum,* upon which, if a stream of hydrogen be directed, the raetu, 
if air has access, becomes ignited, and the gas soon takes fire. 

(&.) It is necessary that die oxygen gas of the air be let in at th» 
same time, and water is tbe result, as if the gases had been kindled 
in any other way. 

(c.) If spongy platinum be introduced into a mixture of oxygen, or 
common air, with hydrogen gas, in explosive proportions, they de- 
tonate ; in other proportions they slowly combbe and form water. 

{d.) The spongy platinum being formed into a paste, with about an 
equal we^ht of dumine, or china clay, and water, with the addlticra 
of some muriate of ammonia, to preserve the porosity, and made into 

' Or the nib-oiide of plitiaum, prepared by Mr. £. Davy's procen, tins«-en, per. 
hMM equally well. 

I Sm UMry, Vol. I. p. 3B8, and Ann. de Chin^ at da Pfajr^ IS, and 24. 



d.^Goot^Ic 



balls of the size of peas, and dried, at first slowly, and afterward! 
more rapidly, the balls will act in the sapie manner as the sponge, 
and their power is renewed by heating them in the blowpipe flame ; 
being thus treated, they wiU, if preserved Ctoia dust, answer a 
thousand times, and more ; their size need not be over 3, 4, or 6 
grains. If one of the balls, fastened ibr convenience, to a piece of 
platinum wire, be introduced into a mixture of air 100, and hydro- 
gen gas 50 measures, it will in a few mbutes be reduced to 87 ; the 
diminubon, 63, divided by 3=31, the proportion of oxygen. 

(/.) In general, the platinum at common temperatures does not 
act upon the gases that are found mixed with hydrogen ; but if the 
ball is hot, it sometimes acts upon the residuary nitrogen to form 
ammtmia, and produces a diminution greater than 63. 

{g.) Moist platinum sponge has the same power as dry, only it re- 
quires a longer time. If some of the ammonio-muriate of plati- 
num be ignited m the sealed end of a glass tube, or if its solutifxi be 
decomposed there, by a rod of zinc, a thin film of the metal will ad- 
here firmly to the interior of the tube. In such a tube, a mixture of 
oxygen and hydrogen, or of the latter and common air, will be de- 
composed in a few hours : and if the hydrogen prevail, all the oxy- 
gen will disappear -, in this manner hydrogen can be perfectly puri- 
fied from oxygen ; even one part in 100 will be abstrected, which much 
exceeds the power of hydrogen alone, aided by the electric spark. 

(A.) Dobereiner supposed this to be a peculiar galvanic arrange- 
ment, in which the hydrogen represents the zinc, and the platinum 
the copper ; but it appears that no heat is produced, unless oxygen 
or atmospheric air is present ; so that the office of the metal appears 
to be to produce a combustion of the hydrogen. 

(t.) Platinum, in fine powder, produces no acdon, not even a slow 
one ; the laminated metal and its wire are equally inert, but thicker 
leaves and wire acted, although sk>wly, when heated to between 
200° and 300°, Centigrade. A very thin film of platinum, rolled 
round a glass tube, or suspended freely in a detonating mixture, pro- 
duced no eSect in several days ; but when crumpled like the wad- 
ding of a gun, it produced instant detonadon. 

(j.) Pladnum sponge stron^y ignited, loses the properq^ of becom- 
ing incandescent ; but produces slowly, and almost imperceptibly, the 
combination of the two gases. 

^kA This phenomenon appears still more remarkable, when it is 
considered that it happens between the lightest and the heaviest body 
known. 

, (l.) If, upon a mixture of spongy platinum, and nitrate of platinum, 
and ammonia, a jet of hydrogen be directed, the mixture reddens, 
crackles, and emits inflamed sparks. 



OMzcdoyGoOgle 



(m.) Altxjiol is turned into acetic acid and water, by the action of 
the sulphuretted oxide of platbum ;* the same effect is produced by 
the black powder which unc precipitates from the platinum solution. 

(n.) Several metals act in a sirQilar manner upon mixtures of oxy- 
gen and hydrogen ; among them, palladium is the most e&ctual ; 
this metal, and iridium inflamed the mixed gases at common tempe- 
ratures, and gold and silver acted efficiently at a heat below 213°. 

Modet of preparitig Platinum tponge. 

(a.) According to my own experience, when common crude grain 
platinum is dissolved in nitro-muriatic acid, and precipitated by muriate 
of ammonia; this orange precipitate being collected by subsidence, may 
be partially dried in a Wedgwood's or other dish, and then transfer- 
red into a plaunum crucible, which may be gradually heated in a 
little earthen fiimace, nil the fumes of muriate of ammonia cease 
to appear. The cover of the crucible may now be put on, and the 
whole buried in burning coats, which may be blown by hand bellows, 
both above and below, until it is fully ignited ; it need remain in this 
state not more than two or three minutes, when it may be withdrawn 
and cooled. 

(6.) The orange precipitate may be thrown upon a filter, the filter 
dried, and introduced directly into the crucible. A greater diviaon 
of the platinum takes place in consequence of the mixture with the 
carbon of the burnt paper, and causes the platinum to -ignite more 
readily in a jet of hydrogen ; neither is there any waste of the pre- 
cipitate.f 

(c.) If a stream of hydrogen from the compound blowpipe, or 
other jet, fall upon the sponge, it will be ignited, and the hythogen 
will take fire.]; 

{d.) If the oxygen be let in at the same time, or immediately af- 
ter, the mixed gases are instandy lighted with a slight explo^n. 



' Procured by precipltsliog Iho muriats of plutioum by BulphureltBil hydrogen, 

t The ufaare clreumatance was abserved in the laboratory of Vale College, by Mr. 

C. U. Shepard, and noted Feb. IT, I8ST. Id Ihe Journal of tbe Royal iDidlatioB, 



be three dmes imtneraed la the lolutioD of 
laavea the plitliium ia the beat state for producing i^lllon. The Editors of the Jour- 
nal ny, that a little of tbe aniiDODia.muriBte of platinum being heated upon platinum 
foil. In a spirit lamp, nlth the mlldeat heat tbat will dleiipale every tbing volatile, 
tbe platinum will be left in a fit state to inflame a mixture of oxyfcen and hydrogen, 
at the lowest poaaible temperature. 

Dr. Webster recommends dipping a cotton cloth in the solutiini of Ihe muriala ti 
platinum, and then burning it to tinder, which, if kept dry, will ignite *■ readiiy m 
the sponge. 

t This cantrivanee is so good a substitute Ibr the complicated, although elegant In- 
strument ofVolta, la whlchajetofhydi«geQia fired byaipark from an eleetropbo- 
Tui, that I have not thought it best to give a drawing and descriptloD of this inMra- 
ment, both of which miiy be seen in Dr. Hare's Compendium, p. 85. 



J cy Google 



334 COUPOUND blowpipe. 

(«.) Then facu ue best eztubtted in pubGc, by pkemi^ iba pla- 
tinum ID a wine glass, but aa it is liable to break from £e sadden 
beat, it is well to place a dish beneath. 

(/.) After precimtation of the orange precaptne, the yellow su- 
pernatant 6uid still coutains platinum, as is incbcated by muriate of 
tin aed hydriodic acid — on evaptvaiion, a scdid is obtained, counstHig 
principally of the muriate of ammcnia, and probably ibe foreign met- 
als ; lor on heating this residuum in a platmum crucible, &s in die case 
of the sponge, a little metallic mstter is obtained, which, however, 
does not ignite the hydrogen. 

HUIe's COHPODND or 0XI-Hn>BO«eN BLOWFITE. 

1. Dr. Robert Habe, of Philadelphia, invented Ibis instramflnt 
in 1801 ; and in December of that year, the discovery wag com- 
municated to the chemical society of that city; in 1803, an account 
of it was published in a pamphlet.* It was used by Dr. Hare and 
the author of this work, in 1802' — 3, and full accounts of their experi- 
ments were pubhsfaed in the Phil. Trans, of Philadelfjiia, Vol. VI. 
Id Dec. 1811, an extensive series of experiments was performed by 
the author, and published in 1812, in Dr. Bruce's Journal, several 
years before Dr. Clarke's experiments were performed. f 

3. Dr. Hare is enUtled exclusively to the merit of the discovery. 
The contrivance of mixing the gases before band in expknive pro- 
portifuis, is all that has been added, and this is not an improvement; 
h introduces a serious danger where there was n(Hie before, and aa 
regards the heat produced, is attended mth no important advantage. 

3. The prbciple of Dr. Hare's instrumeot is, that the oxygen and 
hydrogen gases coming from distinct reservoirs, mingle at the nu^ 
ment of their exit from a capillary ori6ce, and are there ^rnted with 
perfect safew- 

4. Dr. Hare first ascertained, that oxygen and hydrogen gases 
can be made to bum together in this manner; that the heat thus 
evolved, surpasses that produced by any other mode of combus- 
tion, and that it is scarcely exceeded even by that produced by Vol- 
taic electrici^; this might perhaps have been anticipated fixnn the 
great capacity of the gases, especially of hydrogen for beai.| 

■ Which utM rapubllshed in Td. XIT, of Tilloch') Phil. Hag. Lood. utd to ViA. 
XLT, of the Ann. de Cbim. FarU. 

I See Aid. Jour. Vol. I, p. 98, ind Tol. II, p. 181. 

t Being >a lodependenC odginal wlCneai lo die eirly tue, (In 1802.) of Ihit fine fn- 
ittiioient by iCi inventor ; and btTlnf; been in (he habit of using It frequently, for 
Mveral years before Dr. Clarke's eiperimeDti were publiihed, as well u ever snce; 



D„tiidD,Googlc 



COMPOUND BLOWPIPE. 225 

6. The apparatus which I employ, is 
that represBDted in the anoesed figure, 
the parts of which are described at page 
184 ; it is convenient and efib;tual, and 
has, tot many years, enabled me to per- 
form all these interesting experiments 
with great faciUty, and on a lat^e scale. 
By adverting to the strictures of Dr. 
Hare,* and to the statement of the edi- 
tors of the Annsles da Chiraie et de 
Physique,f it will be apparent, that in 
point of efiect, no advantage is gained 
by mingling the gases, previously to 
flieir combustion,J and a serious danger 

is necessarily encountered, notwithstanding the wire gauze, and cH, 
and mercury valves that have been interposed -in die apparatus of 
Newman or Brooke, whose figure is annexed.^ 




It is a small copper box, '(here represented on the left of the page,) 

■ Am. Jour. Td. II, p. 281. t IbM, Vol. Ill, p. 8T. 

t In the appuMUB which I cmplov, ftout tubea of cut illTar are icrewed Into » 
pteCB of plMinuiD, ahaped like the loner fruitrum of a pyruuid, and thU If the 
part or the inatrameDt where the gasea lasue; butcommOD brasa tubes bard aolderrd 
and icrewed Into a silver trustnim, will answer ; care must however be used, that 
the ailver la not melted, which It certainly wilt be, If allowed to liak into the hole 
bamed Into a charcoal support, on which sny thln^ Is melling or bumiac. 

j PrafesKtr Oriscwin was so good U to bring this instrument to Yale CoTlen, some 
yttaw^nce, and we made a aeries of experiments with it, but with do reaulti dlOer- 
ent friNB thaw produced b; Dr. Hare's blowfdpe. Id polat of prcamre, we carried 
It M fir that the copper parallelepiped, was swallen till Its sides were coovez, but no 
lAvntue anwared U be gained by Ercst pressure. 
29 



OMzcdoyGoOgle 



326 COMPOUND BLOWPIPE. 

fiiniislied with an injectmg syringe, for the introduction of the gases, 
previously mingled in the proportions to form water ; it is furnished^ 
also with an Internal valrular apparatus of wire gauze, to guard against 
explosions,* and with a tube of^efflux mounted with a stop cock and a 
platinum orifice. Great pressure may be a convenient means of brine- 
mg more of the gases into the reservoir, but it Is of no avail as regard 
the heat, for not being at their efflux, adequately resisted by the air, it 
amounts to nothing mere than supplybg the gases in sufficient quan- 
tity. The previous accurate adjustment of the proportitKis, may at 
first view seem to be a point of importance, but after a litde experi- 
ence, there is no practical difficulty in hitting this proportion, when 
the gases come from difierent reservoirs ; the eye will easily perceive, 
by the color and size of the flame, and the appearance of the focal 
point, when the proper proportion is attained ; and the effects have 
proved that there is no important difference in the power of the in- 
struments. Mr. Brooke's blowpipe has the advantage in neatness and 
coDvenience of size, but its contents being soon exhausted must be 
frequently renewed. It is obvious that the security of Dr. Hare's 
contrivance may be easily connected with that of Mr. Brooke, by 
simply providbg two condensing boxes of proper size, one for hy- 
drogen and the other for oxygen, and connecting them in the manner 
represented in the' cut on page 225. On account, both of strength 
and capacity, two globes of metal would be most convenient ; and 
an instrument, like tliat in the figure above referred to, would untie 
all the most important advantages of the different varieties of appara- 
tus, hitherto constructed for this purpose, and be at the same time, 
free from their inconvenieaces, and from the danger attending Mr. 
Brooke's. 

6. The figure in the note below represents the form of the instru- 
ment, at present, used by Dr. Hare. It is less simple than those that 
have been described, but the inventor says, that he has found it 
equally convenient in use, as the most ^mple form, " while its parts 
are peculiarly susceptible of advantageous adjustment, "f 



* On n priociple whirh will be illustrKt^d under the Mitoiyof tbe tatetj lamp, In 
the wiion on Ihe cerbu retted hydrogen gases. 

t "l)<i ibnia! bait, with r vcrtknl peruraliDn, terniinaHiiK in n male acrew above, 
md in a female sercvr balDW. Atiotber perforation, at riRnt anfflea lo thla, cauaM 
■ communiealfOD with the tube, t, nliicb enters the ball at rlglit anglea, A ajmi- 
lar, but smaller bmu'ball, may be observed above, wilh perforalioos aimilar to tboaa 
in the larger ball, and a tube, iti like manner, cntciin); it laterally. This ball tar> 
mlDatcs In a male screw below, as well as above. Tha (bread of the lower acrew i« 
curved Id the len, while that of the screw of the larger ball, which enters the same 
nut, n, is curved to the right. Hence the lame motion causes lb e mate screws to ap- 
proach, or recede from each otlicr, and thus dclermines the degree of compreirion 
given to ncerkwhich Is plued between them, in the nut. At S, above the ball, a 
■mall acrew may be obaerved, with a milled head. This ii connected with a Imlll 
tube which passe* through the eortr In the nut, and reaches Dearly to the external 
orifice, 0, from which the flame ia represented as proceedtn|[. This tube is for tha 



D„tiidD,Googlc 



COMPOUND BLOWPIPE. 337 

EffecU of tke compound bloupipe. 

1. Every variety of mineral matter has been melted by it, except 
the diamood; it is evident tliat this substance and charcoal are ei- 
ceptiona, merely on account of their combustibility. 

2. All combustible bodies burn in the focus, not excepting any of 
the metals : the latter exhibit beautiful phenomena, depending on the 
color of their oxides and of the flame : platinum, because it is too fixed 
a substance to form vapor, bums, not with flame but with scintillatioD. 

3. Peculiar facilities are afforded by having two separate reser- 
voirs for the gases. 

(a.) )Ve use the hydrogen flame alone if we wish a lower degree 
of neat. 



moatpulorbniu, bulBlits lower end tanniTiaUfiiiHtuIiciif pUdoi. It oimnrani- 
catM bj lateral aperture* with the CBtity of the upper ball, but in prevented by lh« 
cark, from conimualrBiing with the cavity in (he other ball. Hence jt receive* aay 
na which may lis delivered iolo the upper ball froni the literal pipe which euten 
that ball, but receives Done of the gn which may enter the lower ball, B." 

" Into the female screw o{ the Utter, a pertoraied cylinder of brui, c, with a eor- 
re>p«Dding male Ecrcw, Is Gtlcd. The pertorallon in this cylinder, farmi a coDtiau- 
■tioQ of that Id the ball, but narrmrs below, and enda in a amall hollow cylinder of 
plalina, which fartnathe external ori Gee of the blowpipe, 0." 

" The acrews, t a t a, are to keep, in the axis of the brger bkll, the tube which 
puaea through it, from the cavity nf the smaller bail. The Intermediate nut, br 
compresslQg, about the tube, the cork which surrounds it, prevents any eommnnf- 
calion between the cavities in lbs two balls. By the screw, t, in the vertex, the 
orlGca of the central tube may be adjusted to 1 proper distance from the external 
OTiGce. — Three different cytinders, and as inanY central tubes, with plallraorlfieai 
of dIKrent calibres, were provided, ao that the name might be varied in die, auMt' 
•My to the object In view." 



OMzcdoyGoOgle 



(i.) We let in a portion of oxygen, auae or less, as we wish llie 
iieat to be increased to any degree, till we reach the maxiinum. 

(c.) We ignite charcoal by the compound dame, and then shut 
off the hydrogen, if we wish to have the effects of oxygen gas alone. 

[d.) This is beautifully seen in burning the metals ; we first raise 
the heat by the compound flame, and when the globule of metal is 
heated very intensely, we cut off the hydrogen and permit the oxy- 
gen alone to flow, which at that high temperature sustains, and even 
increases the combustion of tlie metals, not excepting cobalt, nickel, 
silver and gold. 

4. Most intense light is exhibited, by bringing incombustible bodies, 
such as the earths, and particularly lime and argU, in the tarm of ft 
pipe's stem, or of porcelain, into the focus : the naked eye cannot 
endure the light : and in this focus the most refractory substances, 
the rocks, the pure earths and the gems, are melted ; the diamond 
alone excepted, which bums with great intenuly, and is soon exhaled 
in the form of carbonic acid gas.* 

THE AI-KALIES. 

Preliminary Jtemarki. 

Several eimnent writers at the present time, have broken up the 
long established class of alkalies, and distributed them according to 
relations derived from their composition : ammonia b described in 
connexion with hydrogen and nitrogen, and potassa, soda and lithia, 
undw the metals. Similar remarks are applicable also to the earths. 
This course is logical, but it is highly inconvenient; for it is scarcely 
possible to take more than a few steps In the chemistry of particular 
bodies, without calling m the aid of the alkalies, in our experiments 



■For the dcluili ofthew aud of numeroji olberexperimeali, hb Dr. Hire'aoii- 

Sinal pamphlet, ond hi] and my own variout memoirs Id (be Phil. Tram, of Phila* 
Blphla; In Tilloch'i Pbll. Mag. ; In ibc Aonalcs dc Chhoie ot de Phyaique ; In Dr. 

Brnce'a Journal, and in the Amr-" — ' ' 

Dr. Hare remariia, (Couip. p. 

In Tilloeh'a Phil. Mag. and in ill . , 

reaulti In Uurray 'h Sy>tem of Chemlstrj, Ihey bad been generaliy neglected, 
"Hence, (adds Dr. Hare,) a modificalion oT tho hvdro-oxycen blowpipe wai coD- 
trired bf Mr. Brooke. Dr. Clarke, by toeani of tfaia modificitian, repeiited my ez- 
pertmenla and thoia of Prof. Siliimaa, without any other notice of our preteasiaui 
than auch ai waa calculated to convey erroneous imprcKions." 

I regret to Bay that IbiiomiHion, aitbtfueh made known, was never corrected, ind 
that the eKperimcnts of Dr. ClarkQ, most □? which had beeu, yeara before, performed 
and accounts of them pubU<hed by Dr. Hare or myself, were ealjtled (o no credit 
for originality ; while tno almost identity (In many caaes) of the language In which 
they were described, with that used by us so long belbre, proves that the result* 
with the two iDStruments were the same. 

it is not pleasant to transgress the kind maiim, ail de martitit nisi boruim; bnt 
truth obligei mc in this instance to do i I. 

The claims of Dr. Clarke respecting the compoand blowpipe were entinly un- 
founded. 



D,q,fzodbyGo(lg[e 



ALKALIES. ^9 

and reisontng : this remark is perhaps equally true of the principal 
Bcida, end both these importaot claaseE of bodies should be placed a$ 
early aa possible in the hands of the student. It has been already 
Mated, in the plan of the work, that in teaching, I have found the 
moit CMtpeaience in introducing the alkalies before the acids ; al- 
though my preference is not so decided that I should have any seri- 
ous objection to the opposite course. But, I am not willing to post- 
pone ue history of the alkalies and earths until we come to that of 
the metals, and to treat of them merely as appendages of those bodies ; 
and I should be still more reluctant, for the sake of avoiding this diffi- 
culty, to bring in the metals first, or in connexion with the simple 
combustibles, as some authors have done ; nor is it a sufficient reason, 
that the alkalies* and earths then fall in naturally as metallic oxides. 
It is true that modem discovery has increased the diffipul^ of ^ving 
a stricdy loffc&l definition of an alkali ; but the bodies that have usu- 
ally been called by this name are, in some of their forms, familiarly 
known ; they have also a sufficient number of properties in common, 
to distinguish them from other classes of bodies, f and this is the most 
important point to be attained in our arrangements. It is true alao 
that their properties graduate into those of some of the earths; but 
it is sufficient to designate the latter as alkaline earths, and to leave 
the remainder of them to be called earths proper. 

Explanatory Statement, 

The alkalies, when they are to be prepared pure tot chemical pur- 
poses, are generally extracted from their saline combinations, and it 
IS therefore necessary to premise, that a salt is composed of an acid 
and a base: the alkaline salts have, of course,' an alkaline base, and 
the object of our processes is to separate the acid, and leave the base 
isolated, and free also from accidental bodies, ctnimionly called im- 
purities. 

In giving the history of potassa, soda and ammonia, only tt^o acids 
need be mentioned : potassa and soda, as they occur in commerce, 
are usually found combined with the carbonic acid ; and ammcMiia 
both with that and with the muriatic acid. The carbonic acid, com- 
posed of carbon and oxygen, is a gaseous body, which when com- 
bined with the alkalies, blunts their properties, but it is easily remov- 
ed from these combinations, partially by heat and completely by the 
supenOT affini^ of lime. It is also entirely expelled by stronger 
acids, but a new salt is, in that case, formed ; and in general the form- 
ing of such a compound, would rather retard than advance our pn^ 



* AtnoHMkii Bicepled, which bo one trrangea under the melili. 
t It it KiTcely DocCMtry to add, (faU 1 do not Include the new ilktUne vegetable 
preiiroUe priDdplea, mor^ila, delphi*, quiuii, itryehnii, ke. 



OMzcdoyGoOgle 



gress towards obtaining the pure alkali. The muriatic acid is also a 
gaseous body : it cannot be expelled from the alkalies by heat : it can 
be displaced by the sulphuric acid, but that will only engage the alkdi 
in a new combination : to remoire it entirely, we employ lime m thia 
case also, which will attract it away and leave the alkali free and pure.* 

AnnOITIA — POTAS5A — SODA — LITHIA. 

OENER&L CHAIUCTEB OF ALKALIES. 

!a.'\ Caustic to the animal oi^ans. 
6.) Volatilizable by heat, but, except ammonia, not decomposable 
by heat akme. 

(e.) Combine with acids and form salts jf acids and alkalies are 
antasooists. 

(J.) Very soluble in water, even in the state of carbonate ; solu- 
ble also in alcohol. 

(e.) Tum| most blue, purple, and other dark vegetable coters, to 
green ; as tincture or infusioti of violets, and of purple cabbage. 

(f.) Turn most yellow vegetable colors to brown ; as turmeric and 
rhubarb ; and red to purple, as tmcture of brazil wood.^ 

{g.) The colors altered by an alkali, are generally restored by a 
due proportion of an acid. 

(h.) Unite with oils and form soaps ; corrode woollen cloth ; and 
are generally powerful solvents of animal matter. 

(i.) Taste, acrid and peculiar ; particularly difierent from that pro- 
duced by acids ; it is called the alkaline taste, and in a milder hna, 
is observed in pearl ashes and soda. 

Sec. I. — Ammonia.II 
it«nkirA:.-^-This alkali is placed first because of its relation to ni- 
tn^en, and hydrc^en, which have been described. 

■ Hid we benin with adds, an explanilory itateoient would hsva been necevary 

rMpectiog illiuieB md »lts, u two of the moit Important of tbs tieiili, the nitric ind 

muriaHc, are eilnicled from saline combinationi. 
t The definidoD of ilkall propoKd by Dr. Ure, founded on the paw; r of " com- 

l>lldDK with acids, n u to neutralize or impair their activity," would confound tbem 

wMi me Mrtlu and metallic oiide*. 

t Tlie power to afleet vegetable colon, continuea eveD after eombinatiaa with 
mrbonlc add, which diitin^iaheB the allcaline from the earthy carbonaiei. Ammo- 

nlk being a volatile alkali, aotnetimea escapea by evaporation, and the ori^al color 

it thai rmtored. 

J Bibuloua paper, wet with theae colorrd aolutloni, forma teat papen, by which 

Qie ipplicalion of colors Is eaally made. Litmus Ii not changed by alkalies, but If 

previoualy reddened. It is tuned back by ao alkali to it* oiiginsl color, and Ihoa be- 
ll Called tlta the voliflle alkali. Popular n 

dently distilled from the horns of (he hart or 

■^mal matter cotitaln ill elements. 



OMzcdoyGoOgle 



ALKALIES. 331 

1. The n&he is derived from that of sal amraooiac, or tbe mu- 
riate of anunonia, and this from the sandy country of Lybia,* (oiAfwir,) 
where tbe salt was first procured. 

2. DiscoTESi. — ^The gas was discovered by Dr. Priestley, by 
heating the aqueous solution of tbe shops ; he coUecied the gas io 
viab filled with mercury, which was expelled by the gas. 

Procestfor obtaining gateous Ammonia. 

3. Prepaeation. 

(a.) Fromequalparti 
of powdered muriate 
of ammonia, and dry- 
itacked^ quick lime,ia- 
timately mingled, and 
heated rooderaiely in 
a glass retort j| we 
receive the gas over 
mercury, as in the an- 
nexed cut of Dr. Hare. 

It is very convenient 
to displace the com- - 

mon air, by conveying 
tbe gas, by a glass tube 

into an inverted glass ■ ■ . 

vessel ; as in the annexed figure, where a is the flask containing the 
materials; 6 a spirit lamp, for heat; c the recipient, , 
and d the connecting tube. It is obvious that this pro- \ 
cess is founded on the levity of the gas, which displaces 
the air of the vessel. 

(6.) Heat the aqueous solution of ammonia to expel 
the gas ; but this is not an eligible mode, as the water dis- 
tils over, is condensed above the mercury, and reab- 
sorbs the gas. In the process 3, (6.) we know when 
the recipient is full, both by the fsungent smell, and by ^^ 
bringing a feather dipped in muriatic acid near the mouth v. 
of the vessel, when, if the gas is overflowing, there will ''fe^ . _ 
be a white cloud of regenerated muriate of ammonia. When it is 
important to have the gas very dry, unslacked lime should be used ; 
but it is apt to adhere to the glass and break it. 
4. Phtsicai, properties. 

* Cnlleii Ammonia. Some say in alluaion to the Band ; oLhora Io the Icmple of 
Jupiter Am mon. 

( That is, Blacked with iuch a portion of wMer, ai to remaio dry. 

J In all eperatioiu for collectiDi; pases over mercury, ground, tubulated glnt re- 
torts are better Ihan llitaks, as. liom the pre«sure, the latter are apt lole^ at (he cork. 



-I 



D„tiidD,Googlc 



(a.) TttoupareiU and caiorleu; tmdl, highbf odorant and jwn- 

n. — Agreeable, if largely diluted vrith air ; it causes a sharp prick- 
nsation in the hands, and if the skin is moist, it is absorhed, and 
is almost corro^ve ; combining with the moisture on the eye-balls, it 
causes a sensation of intolerable pain. It is therefore decidedlj cau> 
tic, and could it be made solid without combination, it would doubtless 
act on animal matter with as much energy as the fixed alkalies do> 

(6.) Specific Gravity 0.6957, air being 1.— Weight, 18.17, at 
the medium temperature and pressure. 

(c.) Hostile to animal /i/e. — An animal immersed in it instantly 
dies. It kills by suffocation and excoriation ; admitted into the fauces 
H is intensely painful ; it causes a violent spasm as soon as it reaches 
the glottis, and produces the most distressing coughing, and & lasting 
irritation. 

5. Cbekicil propebties. 

(a.) Inttanily absorbed by water, a drop of which being admitted 
and agitated witD the gas, the mouth of the vessel being closed by the 
finger, and then opened under the fluid, it rushes in as it would into a 
vacuum. Ice melts in the gas more rapidly than it would in the fire ; if 
passed up into a jar of gas standing over mercury, the metal rises rap- 
idly as the ice melta, and the gas is absorbed to form liquid ammonia. 

76. J Ice-cold water abiorht 780 timet iti tolvme of thia gat.— 
(Twwwon.) Sir H. Davy has stated its absorbability at 475 ; water 
eaaly absorbs this quantity, and then holds about one third of its 
weight of the gas. Sir H. Davy's more recent statement was, thai 
€70 dmes its volume of this gas, was condensed into one of water. 

(c.) Aqua Ammonia is 
prepared in pharmacy and in 
chemistry, oj passing am- 
moniacal gas, from equal 
parts of slacked lime, and 
muriate of ammonia, heated 
in an iron bottle, through ice 
ccJd water, contained in 
Woulfe's bottles, the contents 
of the first beii^ rejected as 
impure. For a figure of 
Woulfe's apparatus, see mu- 
riatic acid. I annex a cut 
from Dr. Hare, of an appa- 
ratus which will answer for 
a common experiment. It 
needs no explanation. 

{d.) The aqtia ammonia 
tmeUi like the gat ; it is a u 
very useful reagent, and an . 
efficacious medicine. 




OMzcdoyGoOgle 



The more highly water is impregaatecl mtit anunonia, the lighter 
it is,* as appears from the foUowing table of Sir H. Davy, in which 
^e proportions are by weight. 



Sp. gr. 


Ammoula. 


Wtter. 


0.8750 


32.50 


67.50 


0.8875 - 


- 29.25 - 


- 70.75 


0.9000 


26.00' 


74.00 


0.9054 - 


- 25.37 - 


- 74.63 


0.9166 


22.67 


77.93 


0.9255 - 


- 19.54 - 


- 80.46 


0.9326 


17.52 


82.48 


0.9386 - 


- 15.88 - 


- 84.12 


0.9435 


14.53 


86.47 


0.9476 - 


- 13.46 - 


- 86.54 


9.9513 


12.40 


87.60 


0.9545 - 


- 11.66 


- 88.44 


0.9573 


10.82 


89.18 


0.9597 - 


- 10.17 - 


- 89.83 


0.9619 


9.60 


90.40 


0.9692 - 


- 9.50 - 


- 90.50 



Dr. Uref has given another table ; he thinks the numbers in Sir H. 
Davy's too high by about 1 per cent. A vial containing 324 grains 
of distilled water, wiH contain only 316 grains of 8tr<nig aqua am- 
monite. 

(e.) Alcohol cart be impregnated in th& same manner, and it may 
be done at the same time, in a separate bottle of the apparatus. 

(^f.)Ammoniacalgas extinguishes fiame, but bums Htghtly ; very 
evidently, if taken In quantities not less than a pint, and having at 
the same time access to the air, when it bums as it rises, with a 
a voluminous yellow 9ame.| If it were collected in large jars, in 
the manner already described, 3. (a.), it would doubtless bum with 
a flame still more conspicuous. 

(g.) If introduced into oxygen gat, in the form of a jet, it 
burnt, and the products are water and nitrogen gas ; the bydrc^en 
uniting with the oxygen, and leaving the nitrogen behind. 

6. Analysis, composition, and pbopohtion or elements. 

(a.) By the electric ipark, passed through the gas, standing in a 
detonating tube, over mercury. It requires two or three hundred 
discharges to eg^ct the decomposiuon. 



t Diet 2d Ed. p. iti. 



OMzcdoyGoOgle 



!£34 ALSALlEi. 

(4.) Byjvmaee heat, the gas being driven through a poKtelam tube ; 
but the decoinpositioD, is in this way very tardy, and requires an in- 
tense heat to produce a few bubbles of gas.* It is much belter done 
in an iron tube, filled with coils of iron wire, or copper, silver, gold, 
or platinum ; their relative energy corresponds with the order In 
which they are named above, but iron is by far the most power- 
ful. Tiie explanation of this decomposition, appears, at first, not 
very easy ; since the metals do not combine wiili either of the con- 
stituents of anunonia, and are not altered. Probably they act hy 
transmitting heat ; the metals neither gain nor lose in weight, and 
appear to act as conductors only. The resuh of the experiment 
gives 3 volumes of hydrogen and 1 of nitrogen gas, in mixture ; 
electrization gives the sajne result ; hy weight, 17.64 hydrogen, 
82.35 nitrogen ; as the gases are condensed bto halftheir volume, the 
specific gravity of ammonia is not that of nitrogen, .9782+3 hydro- 
gen .2083=1.1865, but half of this =.593.+ 

A soft, pasty, semi ctystallized mass is obtained, when a globule 
of mercury is galvanized, or a piece of potassium laid, in a cavity, 
in a solid ammoniacal salt, particularly in muriate of ammonia; 
it resembles an amalgam, and hence it has been supposed that either 
faydrt^en or nitrogen, or both, has a metallic base ; but the sub- 
slanee has never been obtuned isolated, and no satisfactory conolu- 
siui can be built upon it. 

(c.) By oxygen. — 100 measures of ammonia +50 of oxygen* 
being detonated over mercury in a tube, the oxygen disappears ; 
then add 30 or 35 measures more of oxygen ; detonate again ; one 
diird of the entire diminution is oxygen, and double this is the hydro- 
een ; the nitrogen remains, deducting any that may have been mtro- 
auced with the oxygen gas; this result corresponds wiih that under 
Q>J) giving 3 volumes of hydrogen, and 1 of nitrogen, which, as thejy 
exist in a state of combination in ammonia, are condensed into 2 vol- 
umes ; the decomposidon of amgionia, therefore, doubles its volume ; 
it is, however, no longer ammonia, but a mixture of its constituent 
gases, hydrogen and nitrogen. 

(d.) The mixed hydrogen and nitrogen gases, obtained by igne- 
ous or electrical decomposition, may be analyzed in the same man- 
oer, by detonatioo with oxygen, and will give the same result.]! 



* Aa tlie UDmoniK is tDitintly ibrntbed hy wster, none oTil will pui tttroafrli Ibat 
fluM.Knd the DiixBdgasci obtained, are of coarMhWrog«niodnIliwEii. I have i«- 
peatedly carried this experiment, by (he aid of bcllowi, almost to tSe fiislon of th« 
poccetam tube, without obtainio^ a cubic inch of gas; while If there be iroo in Um 
lube, the gaiai conie over, ahundnnlly. 

t ^^ it the number nliieh we have quoted, p. 232-, Dr. Tbonuon atalei it at .BM. 

t Tite analyils by chlorine is very elegant and eaay. S«e that topic. The ehto- 
rine rcnorei the hydrogen, and leave* the nitn^en. 



D„tiidD,Googlc 



ALKALIES. 33$ 

T. Stktheui. 

(a.) Hydrogen gal and nitrogen goM, mingled tn the proper pro- 
portiont, do not form ammonia, nor woxdd thof ever do it — their spe- 
cific caloric opposes the union ; they would remain always a mers 
mixture. 

(b.) Hydrogen tn its natcent tlate, meeting with nitrogen, form* 
ammonia ; this happens when hydrogen is disengaged (looi moistened 
iron filings, inoluded in a jar of nitrogen. 

(c.) JVitric acid, acting on tin or on photphor\u,fonni ammonia} 
water fumiEhiog the hydrogen and the acid the nitrogen ; it is then 
disengaged by a little lime which arrests the acid, and the ammonia 
ia perceived by its odor, and by a white fume with muriatic acid.* 

{d.) Ammonia u formed during animal decomposition ; both its 
elements being erolred froni the animal matter, and uniting at the 
instant ; this is the origin of ammonia in ^bles, privies, and other 
similar places. 

8. Action on coLOBS.f 

(a.) Red tincture of atkanet beccHses blue ;t blue iniiisi<m of cab- 
bage, green ; diluted yellow lincture of rhubarb or turmeric, brown, 



■ Ann. de Chin, et de Pby^ne, XXIV. 299. 

t I «n Dot mare tbil iny reuon bu been luggeitid for thsw chui^s of eokir ; 
eertalDlf dom hi« occurred lo me thitii oadnfictory. Aia general fact, permaocDt 
chtoges of eotar depend aa ehaores of compoellion, ai b erlneed In liinanMniU« 
cmm; for Iqetaoce, red lead mSrei precipitate contain oxyEeD, ■ c«lorleai ^fr 
and meiali, one or which is while and the other gny; Ind^jo la Inteiwely blue, 
but twcomea green by loiln^ oxygen. In the caie oT tbe teat colon, the color b 
peimaBcnt, aa long ai iha coloring matter i> not decompoMd, trbieh bappraa ovenl- 
nilly, and pertupa we nay say that a oeculiar combinailon takea place oetween tba 
colodDf matter and the acldoralliati, allhougb wecanciveno teuon, any moretbau 
In other cases, why theae particular calora duiuld roauft, or why there atuxild be any 
change of color. 

The autuDiDal hues o£ the leiveaof troeiprahably deDendonaimilar causaa; thi^ 
b to my, on the fuller developc ment of acid or alkali, by the variations of temperature ; 
(br these agentaatwayi exiat abundantly in vegetable tradies, and parllcnlarly In Ibelr 
fluldf. Ills not ImpoHlble that galraiic principles, may aid in producing and nail- 
ifying the effects. 

If any person would examine the leaves of (heninr maple, ibr inattnce, jnH be- 
fore the first autumnal rroets, and while they are still green, ha could earily dedds 
whether add or ilkBli were predominaat, or whether either was to be fcund in a 
ftale of freedom ; (hen let him exaiulne the leaves alter they have turned red, a color 
which we should of course attribute to the developement of acid. A aimilar ^i- 
nlnatlon dwuld be made of the chemical condition ol le»es exhihilliig other col- 
on produced by decay, as Ihe yellow of the hickory, the brawn ot several qiedes of 
oak, be. and so of the diSercot colors observed In reaves of the same treea in the va- 
rious stages of decomposition. 

In the American Journal, Vol. xvi, p. 21fi, there u a reference to an essay on this 
snt^oct. Id the Ann. de Chim. et de Pbys. Aoul, 1S28, In whkh it is sUted, that (be 



OMzcdoyGoOgle 



S36 ALKALIES. 

ius. ; acids bring the colors back, as has been stated in giving the 
general characters. . 

(6.) In applying these colors, we may fill a small tube stopped at 
dne end, or an essence vial, witli ihe colored fluid, and with a finger 
on the mouth, turn it upward into a jar of the gas standing over mer- 
cury ; instantly the color will change, and the gas be absorbed. 

9. COHDENSATION OF THE GAS, BT COLD *ND PRESBDRE. 

This was accomplished by Mr. Faraday,* by disengaging it in 
sealed syphon tubes, from chloridef of silver which absorbs it in 
lai^e quantitieB, 100 grains absorbing 130 cubic inches of the 
gas. The leg of tlie syphon containing the chloride, vras heated to 
100° Fahr. and the other leg kept cold by ice. Ammoniacal gas waa 
evolved, and part of it was by the pressure of the rest, reduced to the 
liquid state. It was a colorless fluid ; its refractive power was great- 
er than tliat of water, and at 50°, its pressure equalled 6.5 atmos- 
pheres ; its specific gravity was 0.76, water being 1 . 

10. Process in the arts. 

By the distillation of bones, and other firm parts of animal sub- 
Btances, ammonia is generated, hy the reaction of its elements, but 
it is more or less combined with carbonic acid. Amoi^ the ele- 
ments of animal matter, we always find hydrogen and nitrogen. The 
ammonia obtained is impure, mixed with animal oil, be. and is pu- 
rified by combinmg it with the muriadc or sulphuric acid, and then 
decomposing this ammoniacal salt by quick lime, in the manner alrea- 
dy described. In the manufactories, Irones and horns are common^ 
employed, and sometimes the refuse of the slaughter houses. Aa 
iron retort or still is generally Aised ; the bones are introduced rough- 
ly broken, and a strong heat applied. A tar like substance, oil, and 
very fetid gases, are evolved, which should always be burned as 
they are both noxious and disgusting. Valves are sometimes fixed 
in uie apparatus to prevent the return of common air ; this would of 
course happen when the apparatus grows cold, and the air hy ming- 
ling with the inflammable gases, might occasion an explosion, when 
the fire is lighted again. Animal chai-coal, mixed with phosphate of 
lime, remains in the iron veesel. J 

11. PhARHACEUTICAL PROCESS. 

To procure aqua ammonite, we may employ either a stilly or 
Woulfe s botdes ; the latter are always used in phdosophical laborato- 
ries ; the proportions of the materials are 1 to 3 parts of slacked fime, 
and ] of pulverized sal ammoniac, and the gas is received in water. 



• PhM. TrjQs. 18M, p. 196. I Marble. 

4 In the large way, on« of iron i« u«c4 nilli i (I 
Dm ttiay be uwd foi the condeDialiiin. 



DK;,lz=..,C00g[e 



ALKALIES. 3S7 

equal in weight to the salt employed ; it is kept cold by ice or snow, 
or at least by cold water often renewed. When the gas ceases, the 
addition of a little wat^r to the materials in the retort, will renew the 
fiow of gas, and produce complete decomposition ; ten pounds of sal 
ammoniac should produce tmny pounds of aqua ammonice, sp. gr. 
.950, and containing about 13 per cent, of ammonia.* The Edin- 
burgh college prepare it of the strength, .989 j that of London, .960. 

12. NATtmAL SOURCES. 

From the decomposition of animal substances, as in privies and 
stab]es,-|- iix. ; it is probable that ammonia is produced geuerally 
during the spontaneous decomposidon of animal bodies ; a pungentr 
revivbg, and andsepdc gas thus springs up, from the very bosom of 
putrefacdon. 

The Chenopodium vulvaria emits this gas in the act of vegetation^ 
and many flowers, even those with an agreeable odor| do the same. 

13. General inference. 

In destructive distilladon, and in spontaneous decomposidon, the 
appearauce of ammonia indicates nitrogen, and of course hydrogen. 

This remark will apply not only to animal substances, but to plants, 
when they afibrd ammcHiia, as a]l those do which putrefy with an an- 
imal odor. 

14. Polarity. 

Ammcmia is attracted to the negative pole in the galvanic circuit, 
and is therefore electro-positive. 

15. CoKBiNiNO WEIGHT 17 — made up of 1 proportion of nitro- 
gen 14, and 3 of hydrogen =17. 

16. Medical and other uses. — These are important ; taken in- 
ternally, in the proportion of 8 or 10 drops to a wine glass full of wa- 
ter, ammonia is a powerful and valuable sumulant, producing the most 
useful effect of alcohol, but without its mischiefs. It is also an ant- 
acid. 

Externally, it is a rubefacient, but it is generally used in the form 
of Toladle liniment, made by egitating aqua ammonisE in a vial with 
olive oil. Ammonia is a very valuable antidote to poison. Either 
the aqua ammoniEe, the carbonate, or the volatile liniment may be 
used externally, and the two former internally.^ 

* Tbe Iran boulci io which quicbiUver U broUKbt, iniwer very well Ibr the d«- 
compoaUioD of Ml unnKuiiac, god Ihe niuritte oTlime is csslly eitracled froo) them 
by bot water. 

t Inlben plices, Ihe ammonit ii mtied with fetid gtm; the pungencv belongs 
to the former, end tbe dlaagree able odor to Ihe Utter. The smiDonM Is ofiea n 
■bunduituto produce a while r load, when, In theie places, the itopperig nithdrawn 
fron « vial of muriatic ecld. In Europe, ancient boteli are ■ometimei filled with 

). 190. 



OMzcdoyGoOgle 



It is given to aninials, to relieve the ioAafion oocarioned by eatiDg 
exoesBively of green gnu, clover, lucerne, £{c. It b of the most ira- 
portant and extensive use in practical chemistry. 
Remarks. 

Aaainonia is ons of those gases which destroy animal life, when 
it is mingled, in only a small proportion, with the air that is.respired. 

It was found by Chevallier in iron rust, in situations exposed to 
animal effluvia ; it was formed when clean inm that had been ignited 
was boiled in pure water, and it appeals to be always formed when 
iron decomposes water in contact with sir ; the water affording the 
hydrogen, and the ur the luirogen. 

It appears also to exist in natural iron orea, such as the red beiqa- 
dte of Spain, the micaceous ore, and the Jenite of Elba.* 

It has already been mentioned that ammonia is formed when mcns- 
tened iron filings are placed in nitrogen over mercury, as ascertained 
by Dr. Ausdn, in 178B. 

Sec. n. — PoTAssA. 

1. Nahb. 

From the potashes of oomtnerce ; and their name is obviouily 
derived from ashes, and the pots (called potash kettles,) in which thq 
lixivium is boiled down. Some of the old names were, vegetable 
Blkali-^«alt of tartar — salt of wormwood, and alkali of nitre, in allu- 
sion to the principal sources from which the alkali is obtained. 

a. PboCEBS or TBE ARTS.f 

The watery hxiviumj of the ashes^ mixed with quick lime, being 
boiled dowi; in the iroa pots or kettles, the residuum is ignited, and 
then constitutes ihe potashes of commerce. Placed in a reverbera- 
tory furnace, and stirred while the flame plays upon it, it beoomeq 
white, and is then the pearlasbes of commerce ; it is thus purified by 
fire only, by the destrucdon of extractive and other combustible mat- 
ter, and the dissipation of volatile principles, gases, &c. ; it loses gen- 
erally about 10 or 15 per cent, of its weight. || 

liie purest alkah is obtained from the mutual action, in a red hot 
iron pot, of nitre 1, and tartar 2; the basis of both salts being potash, 

• Am. Jour. Vol. XIII, p. IBl. 

t To render this proceaa iatelligible, iiaUiiBginorc oeedba prcmiMd Ibm Aal be* 
Met impurities, the potash nf commerce i* fbatid cMnbllied wllh cariwolc acU, 
which the lime delachei hj ibi guperior affinity, aod thos liberate! the allrall. 

t Tbie word is used to denote > lye made wltb adiea, and is derived ttvm tb« 
Lada word lis, denoting thi« preparation, and JUxa is a worker in thit branch of Iha 
Arts.— />arA:ei. 

( When wood !■ burned, the idici ctmitflute ab<nit 1.200tb part of ib welrtl. — 

H See Dr. Roger's account in Am. Jour. Vol. VIII, p. 804. 



OMzcdoyGoOgle 



ALKALIBa. S3A 

hnd tha acids bebg destroj-ed by tbeir action oa each othtr ; also by 
l^idng nitre in a crucible of gold. 

3. Preparation or fotabea, oh pork potash. 

Take 1 pan potashes, or pearl asbes, and good quick lime fi, mth 
abuDdanoe-of water ; boil for an hour, in an iron or copper kettle, oil 
the fluid jjeilher eSerresces with acids, nor precipitates lime water.* 
Strain il though a coarse brown towel, stretched on a frame with tea* 
ter hooks, and hot water should be repeatedly passed through, until we 
have used ten times as much as die weight of the carbonate of pot- 
ash embkiyed. The caustic fluid may be put up in black bot- 
des, and allowed to settle over oight ; the next morning it may be 
drawn ofl* by a g)ass eypbon. To aToid burning the mouth, the sy- 
phon tube may be filled with water, and the Qnger being pressed up- 
on the mouth of the longer leg, the shorter may be dexterously turn- 
ed into the bottle's mouth, without breaking the cdunm m ths sy- 
pboD, the water in which may be allowed to run 
and the fluid is then saved for evaporation. 

In general, filienng succeeds badly with cai 
dkabCB, unless very week, as tiiey are apt to con 
the filters, and .paper can scarcely be used, ui 
for small assays. If the filtering is slow, the 
bonio acid of the air is apt to combine with the al 
and to prevent this, Mr. Donovan conlrived the 
■nezed apparatus, ia which A is the tillering fur 
vrttoee mouth is obstructed by folds of linen i^ '. 
the receiving vessel, and c is a connecting tubi 
prevent, at once, any communication with the ei 
nal air, and any accumulation of pressure in 
lower vessel.} 

(b.) Boil the sohition^ down to dryness m a clean ifon kenle ; &ae 
the mass in a ulver crucible ; pour it out on a marble slab ; break it up, 
without delay, and cork it tiaht from the air in a glass bottle. Cream 
of tartar, ignited in a cnit^le, disserved in water, filtered, boiled 
with sufficient lime, obtained clear by sub^dence and decantation, 
•ad solid by evaporation in a silver vessel, to the conastence of cul* 
pna a cake of the pure hydnte of potassa, without the u«uble of 
iiung alcohd. It mast be put up immediately, in close bottles.— I7re. 



I Belter b; fragments of glan, coarser belotr and finer uid finer above ; water b 
ptued through, both before and afler ui experinMnl, to reotove impUiiUaa, Mtd thua 
a permaneDt filter it obtained for acids and other comwive Suidi. D. O, 

1 AnD.Pbil.26. lis, and Turner, 2d Ed. p. lOS. 

K For a table shewlag the real quinlllle* of alkali Id aqneog* •olutiDBa.aM Il«Brr, 
Vol. I, p. 928, lOlh London Ed. 



OMzcdoyGoOgle 



340 ALKALIES. 

This substance, mixed with lime, and fused and cast in cylindrical 
moulds, forms the caustic called lapit it^emalu, or lapis causdcus 
of the shops. It is said that oxygen gas is disengaged, during its so- 
luuOD b water, and that it varies apparentiy with the impurity of the 
specimen. 

(c.) It it note cmittic, but contains aU the tolvhlt impurities, chief- 
ly salts, carbonate, muriate, and sulphate of potassa, sUex, and oxide 
of iron and manganese, kc. ; to purify it, dissolve it in good alcohol ; 
the solution will be wine red ; the watery solution of the salts be- 
low is immiscible with die alcoholic solution of the alkali, and the solid 
impurities are at the bottom. Evaporate the alcohol,*^ and finish the 
process in a silver ba^ or crucible, with moderate ignition ; then 
break up the mass, and secure it from the air. 

It still contains a Utde carbonic acid, ariamg from the reaction of 
the alkali on the alcohol, or absorbed from the air. The addition of 
barylic water, previous to the last evaporation, will entirely remove 
the carbonic acid. 

(d.) Hydrate ofFotaua. — ^This is the substance above described. 

If the whole of the alcohol be not expelled, the alkali will, on cool- 
ing, crystallize in single or double plates, needles, or tetrahedral py- 
ramids. This hydrate contains one proportion of water, 9, and one 
of polassa, which, as we shall see under potassium, is represented by 
48, and its equivalent is therefore 57. Heat alone will not separate 
the water from it ; if it is urged, the alkali will rise along with the 
water, which can be separated only when it enters into new combma- 
tions. 

4. Properties, 

(a.) Solid at common temperatures; melts at 300°, and is vola- 
talized at low ignition, with a visible cloud of caustic fumes, highty 
acrid ; color, white or gray ; taste, when strong, burning and in- 
tolerable ; corrodes and destroys animal and vegetable substances, 
subverting completely the organic texture, and in a word, it posses- 
ses, in perfectioD, and in full energy, all the characters of alkalies, 
mentioned in the introduction to their properties. 

(&.) It affects vegetable colors as ammonia does ; in addititm to 
the colors enumerated under ammonia, it may be mentioned that a 
strong infusion of the dried flowers of the red rose, answers very 
well. — Parket. 

(c.) Deliquetcet rapidly in the air, and by absorbing carbonic 
acid, becomes partially mild again. It acquires moisture so rajudly, 



■ OrdlMil oir iDd UTS the firct hair of It, in > rscejver, u It trill be ijeohal of a 
fMd quality ; tba remainder will ccntila more water, ind ii icarcelj woMll «•- 
viDg ; than U danger, beiidea. If we evaporate too low in t glan venel, that It will 
lie attacked bj the tllnH. 



OMzcdoyGoOglc 



AIAALIIS. S41 

from the air, as speedily to ctiange the color of any of the alkaline 
test pajpers upon which it is laid. Tunneric psper ahews it wdl. 
CrynaOized hydrate of potassa, produces cold during its solution in 
water, while the solid alkaU evolves heat. 

5. CoHPosiTioN. — See potasgum. 

6. FoLABiTT. — Electro poiitive ; it is attracted to the negative 
pole in the galvanic circuit. 

7. Obigin. 

From vegetables that hare no connexion with salt water. Plants 
yield more than trees ; the hranches more than the trunk ; the small 
branches more than the large, and the leaves most of all. Her- 
baceous plants yield more ashes and more alkali than wood. Fumi' 
tory* is said to yield more salt than any other plant, and wwmwood 
more alkali than any other vegetable. 

One thousand pounds of the following vegetables yidded aaline 
matter in the following proportions. 

Wormwood, - - 748 Fumitory, - • 360 

Stalks of sunflower, 349 Beech, ... 3i9 

Stalks of Turkey Wheat, or Elm, ... 166 

111 

- 119 

61 
JBnwm. 

Fern leaves are used m Yorkshire, in England, in cleaning ckMh 
for lulling, and appear to afibrd alkali already developed. 

In the Highlanos of Scodand, soap is made from the alkali (Ay- 
tuned from the ashes of peat. 

The resinous and odorous woods afiiK'd little alkali ; hence die 
adies of pine wood are regarded in fomilles, as worthless f(» soap- 
making. 

Potatoe tops yield a great deal of alkali. 

The alkali of^a^es arises principally frmn salts existing in the veg- 
etable Juices, and modified by the fire.f 

8. History. 

In an impure state, it was known to the ancients ; Pliny stttes that 
the Gauls and Germans formed soap of ashes and talloW ; and Dr. 
Thomson diioks that their a^es were the same with oar polasfa. 

■ la Hr. Klrwu'a Ubla, quoted 1& the teit, Funritar; Is lUled bi jleld bat tboat 
half u roucb raline matter u worm woad. 

t A« Ibe alkali of veraUblei b oM *a eoealial coudtuont, and is dertred from the 
foil, the quantiljr wh^h any plant will aS>rd, will depend ot> the qualtUM of the 
earth, in which It a railed. Hence we ran account for the diaerepandei of dtfiereot 
eiMThsctilen reipecting the relative quantltle* of alkali aRbrdcd by dUierent phMt. 

31 



Maize, 


- 198 Fir, ■ 


Vine branches, - 


162 6 Oak, 


Fern, cut in Aug. - 


' 116 Heath, 


SaUow, - - 


. 102 Aspen, 


Box, - - - 


78 



D„tiidD,Googlc 



243 ALKALIES. 

Indeed it was not known in purity until 1786, when Benbollet g«ve 
ibe process by alcohol. 

In the ruios of Pompeii, which was overwhelmed by an erupticHi 
of Vesuvius, A. D. 79, " a complete soap boiler's shop was discov- 
ered, with soap in it, which had evidently been made by the combi- 
nation of oil and alkali," and it was perfect, although it had been 
made more than seventeen centuries.* 

9. Tests foh potash, f 

1. With an excess of tartaric acid, it forms a precipitate, which, 
when stirred with a glass rod, forms peculiar white streaks. 

2. Muriate of platinum gives a yellow precipitate, a triple salt of 
platinum and potash, forming, by gentle evaporaUon to dryness, and 
tJie addition of cold water, " small shining crystals." 

3. Potasli is precipitated by nothing. — Turner. 

10. Pharmaceutical pbeparatidn and medical csb. 

The pharmaceutical preparation does not differ materially from that 
which has been already described for the puriGcation of tbe alkali. 

The principal use of caustic potash is as an escharotic ; the cylin- 
drical masses found in the shops, are often impure, and partially car- 
bonated and deliquesced, and will sometimes disappoint the practi- 
doner. That which is carefully prepared by the process 3. (a.) and 
(A.) is much more [mwerful. Potash is mixed with lime to render it 
milder, and less deliquescent ; this is the kali cauaticum mm calce, of 
the [riiarmacopeias. The pure alcoholic potassa, prepared by the pro- 
cess 3. (c.) is a very certain caustic, and if fused at ignition, in the 
Gonclusion of the process, broken up immediately, and put up in close 
viiJs, it discovers, even in several years, no disposition to deliques- 
cence, and preserves its crystalline structure. t 

Caustic alkali has been used as a lithontriptic. When the concre- 
tions consist of uric acid, or urate of ammonia, there is often a favor- 
able effect produced, but it is difficult to persist long in the use of 
auch a remedy, either by the mouth or by injection into the bladder. 

When there is to be a long perseverance in the use of alkaline 
remedies, they must be taken in a milder form, as will be menti<Mi- 
ed under their carbonates. 



* Farirm' Ctiem. Enaya. 

1 The nitraU, oxalate, or oiide of nickel, fuse<l with borax, will give t blue color 
with nitre, feldapar, or any aubstance containliig polaah, and the presence of loda 
doea Dot prevent (he appearance of the color; if nickel contains cobalt, the glaai 
wUl have a brown color.— Jm. Jmimal, Vol. XVI.p. 387. 

t The Ute celebrated Tit. Nathan Smith used to obtain this alkali fiDm the lab- 
oratory, la all cases nhen he wSihedan energetic and certain eflect, and it never dia- 
appinnted him. I have many times eanc throufrh the whole labor of preparing it 
anil although the processes Hre troiiblFKomp. the result is very vB)ual>lB, both lo 
ehemlstry and' medtrine. 



D„tiidD,Googlc 



Remarks. — Common ashes effervesce powerfully with adds, and 
they easily give a solulJon with hot water, which affects the taste with 
the perception of aUcalinity, and the test colors with tiieir appropriate 
changes. 

The most familiar use of a lye in families, is in soap making, and s 
principal cause of failure is, that the alkali is not rendered cnustic by 
the application of a sufficient quantity of good quick lime. The den- 
sity of the solution is ascertained hy the family hydrometer, an egg, 
which floats when the solution is sufficiently dense ; but it raay be 
dense without being causdc, and if it is not caustic, it will act but 
partially in forming soap. It should not efTervesce with acids ; if h 
does, It is proof that Uie carbonic acid has not been all withdrawn, 
and it may be necessary to pass It through more lime. If it is too 
weak from having too much water in it, this is easily removed by 
boiling it down. The subject of saponification will be mentioned 
again under oils, vegetable and animal. Lye has a valuable antisep- 
tic edect, and is often used in families, as a part of poulbces, and 
also to counteract the tendency <^ wounds towards tetanus. 

This alkali, as it separates almost every base from acids, and as it 
acts with great ener^ upon many substances, is of great utility in 
chenustry. It is an immediate antagonist of acids, and fotms salts 
with them. 

JUkfdimeter. 

Iliis umple instrument is founded upon the fact that 100 grains 
of pure subcarbtmate of potash, are saturated by 70 of strong sul- 
phuric acid. The acid is placed in a glass tube graduated into 10& 
equal parts, and the tube to the extent of the graduations, is then 
filled with water. The purity of the alkali to be tried, will be as- 
certained by the proportion of this diluted acid which it requires for 
perfect saturation ; if there be 60 per cent, then 100 grs. wiU require 
€0 divisions, and so in proportion ; if pure, it will require it all. 

If we would ascertain the proportion of pure potassa in the salt, 
then we must employ 102 grains of the acid, and dilute it with the 
same quantity of water, requisite to fill the tube. — Ure. 

This alkali is of vast importance ui glass making, soap making, in 
medicine, in domestic economy, and in various arts, and it constitutes 
an important article of commerce, especially from the United States 
to Europe. 

POTASSIUM. 

1. Discovery — by SirH. Davy, in October, 1807.* 

* See the Bakeriaa Icctura for that year, in the Pliilof. Train. Although aods' 
hw not been, an yet. deecrll^ed in Ihia work, I wi)1 give the account of the dncovery 
of It* decompoeition io connexion with that of pnlassa. as the factn in Ihe two cues 
are very iiimilar. and are io both perfectly inteiligible. A more pBrticul*r alale- 
ment of Ihe properties of sodium will be aflGnrarda i^veu. 



D„tiidD,Googlc 



DEC01IP091T10N OF POTASH AND SODA. 

1. By galvaniim. — ^The first attempts of Sir H. Davy were made 
upon aqueous solutions of potash and soda, but the water alone was 
decomposed. He then kept the potash in perfect fusion by an in- 
genious cixitrivance ; it was contained in a spoon of platinum, which 
was, in the first instance, connected with the positive »de of a battery 
of one hundred pairs of six inches, highly charged, and the connexion 
from the negative side was made by means of a wire of platinum. 
A most intense light was exhibited, at the negative wire, and a 
column of flame arose from the pobt of contact. When the spoon 
was made negative, and the wire positive, a vivid and constant light 
appeared at its point, and aeriform globules which inflajned in the at- 
moephere rose through the potash. 

A smaU piece of pure potash, slightly moistened by the air, so as 
to give it conducung power, was placed on an insulated disc of pla- 
tinum, connected with the negative side of the battery of the power 
of 250 pairs of 6 and 4 inches, in a state of intense activity and a 
platinum wire, communicating with the positive ^de, was brought in 
(Xmtact with the upper surface of the alkali. The whole apparatus 
was in the open atmosphere. 

There was a fusion of the potash at both surfaces — a violent ef- 
fervescence at the upper, and at the lower, ' small globules, having a 
high metallic lustre, and being precisely similar, in visible characters, 
to Quick^lver, appeared, some of which burnt with explosion and 
bright flame, as soon as they were formed, and others remained and 
were merely tarnished and finally covered by a white film which 
fbrmed on their surfaces. 

These globules were the basis of tlie potash ; they did not pro- 
ceed from the platinum, for they appeared equally, whether copper, 
atver, gold, plumbago, or even charcoal, whs employed for com- 
pleting the circuit. The air had no agency in producing the glo- 
bules, for, they were evolved when the alkali was placed in a 
vacuum,* 

The substance was likewise produced from potash, fused by 
means of a lamp, in glass tubes, confined over mercury, aud furnish- 
ed with hermeucally inserted platinum .wires, by which the electrical 
action was Uansmiued. But the glass was go rapidly decomposed 
by the substance that the operation could not be carried far. 

The substance produced from potash remained fluid at the tem- 
perature of the atmosphere, at the time of its production. 

* I repait«d Umm experimenli in 1810, sni] then ablalasd the metalMdi ; fee 
BrOM'i Jounul. Dr. (now Pros.) Cooper first decgmpoaed potuli in thia country 
by ibe gun t»rrel uul funitco. 



OMzcdoyGoOglc 



THKOftT OF THE FHENOMXNA. 

These decompoatioiu agree perfectly with those which have been 
bef(H« described ; oxygen is evolved at the positive wire, and the 
combustible with which it was united at the negative. When the 
solid potash or soda was decomposed in glass tubes, the new sub- 
stances were always evolved at the negative wire, and the most deK- 
CBte examination proved that the gas liberated at the posiuve wire 
was pure oxygen, and, unless more water was present dian was ne- 
cessary to give conducting power to the alkali, no' gas whatever was 
raven out at the negative wire.* The aynthedcal proofs were equals 
^ satisfactory. 

The bases of both alkalies, when exposed to the atmosphere, be- 
came tarnished and covered with a wlute crust, which immediatelv 
deliquesced ; water was decomposed, a farther oxidizement took 
place, more white matter was formed, and the whole became a sat- 
urated solution of fixed alkali. When the metallic globules were 
confined over mercury in oxygen gas or common air, an absorption 
took place, a crust of alkali instantly formed, and, for want of mois- 
ture uie process stopped, the interior being defended from the actim 
of the gas. " When the substances were strongly heated, confined 
in given portioos of oxygen, a rapid combustion with a brilliant white 
flame was produced ; and the metallic globules were found convert- 
ed into a white and solid mass, which, in the case of the substance 
from potash was found to be potash, and in that from soda, soda." 

2. Br THE FUBHACE. 

(a.) The next spring, 1808, potash was decomposed in a gun 
barrel, in Paris, by Gay Lussac and Thenard. 

{b.^ Very many precavtioiu are necenary to secure ruccets.-f 
(c.) Principal particulars. — Provide a clean sound gun barrel 
bent, so that the middle shall be curved a little downward, while the 
end in which the potash is to be placed, shall incline gently upward, 
and the other end downward ; it must be protected by a very refrac- 
tory lute, made of coarse fuliceous sand and potter's clay, with as much 
sand as can possibly be worked in, and dried with extreme slowness; 
place the tube across a furnace ; potash in fragments is put into the 
elevated end out of the furnace ; this is the breech of the gun barrel, 
and the breech pin is now put in with a lute ; clean iron tumii^s are 
introduced into the beUy of the tube in the part which lies in the fur- 

■ Some have nippoied thai the hydrogen combine* nith the pure alkali ro 
fbrm the meUl!. 



t Sea Recherchcj Physico-Chlnilqtief; aim, mv tnnalalian ot the Memoir of Gay 
LuHae and Thenard, in the Boelon Edition of Henry'a Chemirtry, 1614 ; alao An* 
Dale* de Chimie, LXV, 329 ; Memoirof d' Arcueil, H, iSO. 



OMzcdoyGoOgle 



S4€ ALKAUK8. 

nace j a stop cock and tube of glass bent downward at right angles, 
are fixed at the other end ; the glass tube dipping into oil ; both ends 
are kept cold by water or ice, till a great heat is raised by a powerful 
bellows blowing with a large orifice, so as to introduce abundance of 
air ; the potash which should have been previously ignited, before 
its introduction into the tube, is then slowly melted by a portable 
furnace, and running down upon the ignited iron, is decomposed ; 
its oxygen is fixed in the iron, and hydrogen gas being abundantly 
disengaged from the tube, holding potassium io solution, and being 
spontaneously inlknimabte, it flashes frequently and with intense 
brightness ; the potassium rises in vapor and congeals in the cold 
end of the tube ; it is then cut out by a knife dipped in naptha and 
is preserved under that substance. It may he melted heneaih it, 
and is readily moulded by the fingers smeared with naptha, into any 
form and into pieces of convenient size. 

The great difSculty is in preservuig the gun barrel from oxidaticm 
and fusion.* 

Curaudau of Geneva, ia the same year, shewed that potash might 
be decomposed by charcoal alone, by mixing it in powder with twice 
its weight of dry carbonate of potash, and heating die mixture strong- 
ly in an iron tube or spheroidal iron bottle. Prof. Brunner has im- 
proved this process. His apparatus is a spheroidal wrought iron 
bottle, of one pint in capacity, and half an inch tliick ; a bent gun 
barrel, ten or twelve inches long, screws into the moutli of tlie bottle ; 
the apparatus is well luted, and the gun barrel protected by iron wire 
wound around it, dips into a vessel of naptha, kept cold by ice. In 
one experiment, 6 oz. of iron fihngs, 3 of charcoal, and 8 of fused 
carbonate of potash, were inumaiely niingled and heated in a fiimace, 

.when 140 grains of potassium were obtained. It appears, accord- 
ing to the original observation of Sir H. Davy, tiiat " potash or pearl- 

. ash is easily decomposed by the combined attractions of charcoal and 
iron ; but, it is not decomposable by charcoal, or, when perfectly dry, 
by ir<^ alone. Two combustible bodies seem to be required by their 

■For Imprared processel, ice Ann. of Phil. New SencB, VI, 283 ; Quarterly 
Joum*! of London, XV, 879; and Annates de tliiin. XXVlt,S40; sl«). Am. Jour. 
Vol. VIII, p. 3T2. It nould be diffirull, williaut an amount of dcUi) wlik-li is in. 

^ eonii'leiil with the limltii of (his work, to clsle all tlie circumstance? Ihnt influence 
tbe succea of (Iiis dilficuli process. Soon after tlie discovery of tbis method of ob- 
talniag potaHium, and for xaveral years .iftcr, I labored much in this field, having 
gone inany times, through every part of the operation, from the preparation of the 
caustic alkali to its decompiMiliDn, and the evolution of its metal; 1 was a coadju- 
tor at diflerent periods, m these eiperimciilii, with Dr. Hnrc, Prof. Dewey, and 
Prof. Olmiled. The sUtemenU of Gay Liusac and Thenard, are extremely pre- 

. else and very full ; perhaps I might have added aotne thin^ from my own e.xpe- 
Hence, but it is rendered unnecessary by the fact, thai easier means have been 
discovered, and potassium, from being one of the dearest ofajl substance*, is now 
within the reach of every one, ' 



OMzcdoyGoOgle 



ALKALIES. 247 

combined aflinilies for ihe effect j thus, in the experiment with the 
gun barrel, iron and hydrogen are concerned." 

It would seem, however, that charcoal atone has succeeded in the 
hands of Wohler, who employed the cream of tartar, after bebg 
heated to redness in a covered crucible. The tartar may be calcined 
in the same iron bottle in which it is to be decomposed, and it is ad- 
vantageous to mix a little charcoal with the tartar jwevious to calcin- 
ation ; 300 grains have been obtained from 34 o2. of crude tartar. 
Prof. Berzelius is said to have oht^ed half a pound at one opera- 
tion.* 

4. Properties. 

(o.) At 60° or 70° Fahr. it is imperfectly fluid j perfectly so at 
100^, and of course at a higher temperature ; when mehed under 
nap^a, it cannot be distinguished from mercuir ; at 150^, two glo- 
bules will run into one ; at 50°, it is a soft solid, plastic m the band ; 
at 32° or lower, it b brittle ; breaks with brilliant lustre ; and when 
broken, exhibits through a microscope, a crystallization in facets vctj 
white and splendid ; at about the heat of ignition, it is volatile, rises 
in vapor and if air and moisture are excluded, condenses unaltered. 

Sb.^ It is a perfect conductor of heat and electricity. 
c.) Sp. gi. about 0.865, (G. L. and Th.) 0.876, Bucholz or from 
.8 to ,9, water being I . Davy. That obtained by chemical means, is 
a litde heavier, owing to carbon or iron combined with it, but it is stff- 
ficiendy pure for experiments. 

{d.) In the air or by moisture, it is oxidized and becomes again 
caustic potash; it cannot be preserved except under naptha; if that 
fluid has been recently distilled, and the vial is full of the fluid, the 
potassium may be kept under it for years, only it will collect a film 
of soap around it ; the metal may be examined in the fur, if covers 
ed with a film of naptha. 

5. Oxides. 

(a.) I^ protoxide is formed by the action of water, the air being 
excluded ; in that case, there is great efiervescetice, but no flame ; 
40 grains of potassium decompose 9 grs. of water and evolve 1 gr. of 
hydn^en gas, while the other 8 grs. combine with the metal ; thence 
the quantity of oxygen is inferred ; also, from the oxygen absorbed 
by potassium when it is exposed to dry air ;t if it is in thin slices, 
the protoxide is formed in this manner also. 

Proportions, potassium, 83.34, oxygen, 16.66=100.00. 

Iliis being nearly in (he proportion of 1 00 potasdum to 30 oxygen, 
it follows, that 20 ; 100: :8 ; 40 ; 8 being the representative nuin- 



•Grahim.«nd Kb. Univ. XXII. 36. 

t Accorddig to Tlienant, it i» the only melal IhM li *rleit upon by perrertly dry 
onyiteQ ga*. 



DMz.dDyG00g[e 



ber of oxygen, 40 becomes that of potassium, and therefore the num- 
ber for ^otoxide of potassium is 46. 

(6.) FroperHeiof the protoxide, bee from water; (his is its ctm- 
ditioD when it is formed m diy sir or in dij oxygen gas. It is white, 
very caustic, and fudble a bltle above a red heat, but it requires a 
rery high heat to volatilize it. 

Dissolved in water and obtained again, it becames even after igni- 
tion, a hydrate, containing protoxide of potassium, 84, water, 16=100. 

Potassium being represented bv 40, oxygen by 8, and water hy 
d, it follows that the equivalent of hydrate of potassa is 57. This 13 
the substance described under potassa. We know not whether the 
solid anhydrous poloxide is caustic or not, because its properties 
cannot be exammed in this particular, without admitting water to it, 
when it becomes a hydrate. It has already been observed, that the 
hydrate melts at a low heat, (360°,) and is easily volatilized. The 
prt^xide is formed also by acting oo potassium with a small quantity 
of water, or by heating potasuum with common caustic potassa, and 
by igniting potash in a crucible of gold. 

(a.J 'Die whitt dry protoxide heated ia oxygen gat, abtorbi txBO 
additwnal proportioni, and becomet of an orange color. — It may be 
formed also by he^g and bumii^ potas»um in oxygen gas, or in 
common air. 

(b.) h* proptrtiet. — Color yellow j fusible with less heat than hy- 
drate of potassa, and crystaUizes m laminie by cooling. When plunged 
into water, the two additional proportions of oxygen are evolved, and 
it becomes hydrate of potassa. Heat greater than that at which it 
was formed, expeb the excess of oxygen, and brings it to the state of 
protoxide or true anhydrous potash.* The heaong must be per- 
formed in a pladnum tray, and the oxide covered with muriate of pot- 
ash. When mixed with combustible bodies, and heated, it acts vig- 
orously upon them in consequence of the two additional proportions 
of oxygen which it contains, and it thus becomes potassa. The com- 
position of the peroxide is potassium, one proportion 40, and oxygen 
3=24, and its equivalent number is 64. 

Nitn^en and potas^um have no action upon each uher, but if 
potassium be heated in ammoniacal gas, a fuable olive colored com- 
pound is formed, which consists of nim^rai and potassium, and of 
this compound and ammonia, and at the same time, hydrt^en gas is 
liberated. As it appears not to be particularly important, we refer 



*Thl«i«Mid tobeaofized u to niitaln the heat of a wind fnnuce witboal bclns 
Tol*tl1tz»d ; It ■ttracb water very powerfully, ind nDoratn iDt«iiM tkCU during It* 
Mlntiaa. The hydrate of (he protoxide it ewlly volaliiiied by heaL 



OMzcdoyGoOgle 



AMCAL1E6. 249 

ibr a more full account of its properties to Thenard, Vol. II, p. 413, 
4th Ed. 

6. MlSCeLLAITEOUS PHENOMENA. 

(a.) fVhen thrown upon water, potasnum floats, melta, becomes a 
poiithed sphere, runs briskly about, takes fires, and emits brUlimtt 
white red, and violet light, wiih fumes of caustic potash ; sometimes 
rings of white smoke, from the combustioD of potassuretted hydro- 
gen are formed in the air, and the regenerated alkali, by becoming 
red hot, often produces a slight explosion ; if the piece is as large as a 
pea, the explosion is sometimes violent, and jets of the burning metal 
are thronn about the room, followed by white streaks of caustic potash. 

The moving power that impels the floating metal, is potassuretted 
hydrogen gas, aided by steam, both being generated beneath the 
globule ; the explosion is caused by tlie ignited caustic potash, com- 
bining with the water. 

[b.) On ice, potassium ads in a similar manner ; it bums and melts 
a hole, in which, the existence of a solution of caustic potash is ea^- 
]y ascertained by turmeric paper ; it sometimes explodes on tee. 

(c.) Placed on ignited iron, it bums in common air, and brilliantly 
in oxygen gas, producing abundant white alkaline fumes, which are . 
soon condensed on the interior of the glass vessel. 

Jd.) Cht all the test fluids — c^Abage, turmeric, alka7iet,fyc.iibvrm 
produces the effect of an alkali, and that altbougli they may have 
been Srst changed red by an acid: the experiment is strikingly exhib- 
ited in a small glass flask, containing the watery solution of these colors. 

(e.) /( flames on the three strong minerals acids, producing with 
them salts of the respective acids: the sulphate of potash, on ac- 
count of its insolubility, sinks through tlie fluid in white streaks. 

(/.) It dances about on alcohol and ether, gradually wasting away, 
but generally without flaming, and ihe globule looks like polished silver : 
in the very best ether it sinks, and when it rises it does not of course 
prove that it is lighter than the ether, as it is often made buoyant by 
the hydrogen generated beneath it. . It discovers and decomposes 
even the small quantities of water contabed in ulcohol and ether, and 
being insoluble m the latter, it forms in it, a turbid cloud of potash, 
while hydrogen is disengaged. 

(g.) With oils it slowly forms soap, and when kept even under 
naptha, in vials carelessly closed, it, in the course of some time, be- 
comes entirely saponified ; absorbing oxygen first to form alkali, and 
this uniting with the naptha to form soap. Potassium, when heated 
in the concrete oils, (tallow, spermaceti, wax, fSic.) acquires oxygen 
even from them, gas rises, the base is slowly converted into potash, 
and a soap is formed. 

(A.) On test papers, if moist, it nms about, changes ihe color, and 
fires if there be moislure enough. We shmild never loiichitwiih 



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250 ALKALIES. 

moist hands, as it immediately blazes, and we have in that case, borfi 
the actual and potennal cautery ■ 

(i.) Hydrogen gas, heated m contact witk potasnum, diaaohet it, 
4na becomes spontaneously inflammable, but loses this property by 
standing, and deposits potassium again, A solid compound of potoa- 
sium and hydrogen, is formed by heating the gas and metal together, 
irith a spirit lamp. It is gray, dull, infusible, and not inflammable, 
except at a high heal, when it bums vividly. 

7. Powers of combinatiok. 

They are almost univertal, at wUl amiear farther on ; it unites with 
iodine, chlorine, the metals and most of the combustibles, he. and it 
decomposes the acids, most of the oxides and salts, and animal and 
t^etable bodies, and few substances, simple or compound, are im- 
Hfiected by it. Its greatest prerogadve however is to attract oxygen, 
which it takes from every tning, even from glass and stones, and 
from the firmest compounds, both natural and artificial. 

8. In relation to the state of our knowledge, it it an element. — The 
most singular circumstance in tbe character of potassium is its levity : 
it resembles the metals very much in tiie greater number of its prop- 
^es, but differs from them remarkably in specific gravity, wlule m 
its extreme inflammability it ts assimilated to the most combustible 
bodies.* 

9. PoI-AItlTV Aim COMBINING PROPORTION. 

Like other inflammable and metallic bodies, it resorts to the nega- 
tive pole in the galvanic circuit, and is tlierefore electro-positive. Its 
combining number or chemical equivalent has already been stated to 
be 40, hydrogen being I.-|- 

10. Uses, — As yet tliey are exclusively philosophical. In the 
hands of the chemist, it is a fine instrument oi analysis, especially in 
the agencies which it exerts upon oxygen. It is a splendid substance 
for experiment, admitting of many beautiful and instructive modes of 
exhibition. From tlie improved modes of obtaining it which have 
been discovered, there seems little reason to doubt that it may be 
manufactured to any extent that may he required, and its introduction 
as a new means of annoyance and destruction, would perhaps not be 
improbable, were it not that it might prove nearly equally dangerous 
to friend and foe. 



* Th«M propertiBS, wilh the remirkkble fact, that duriagthe nlviolc 

lion of Ihe alkali, allhough oxygen ia evolved at tbe positive pole (here iBDohydronn 
l^iveD off at the Dcgiitive, led (o the presuinplion that polagaa 1) not n compouDd of 
oxygen and potassium, but or potash nnd hydiogen ; the oxygen arising fnnn Iho 
decompotilion of water, and the hydrogen of that fluid ^ine; iota union nilb the 
alkali to produce paliuaium. For in InEenious diacuaalon of Iheae and aome other 
aimflar viewn. see Murniy, 6th ed. Vol. Tl, p. 2T. 

t Mr. Mjiray hts stated some reason* why It may ralher be supposed to be 41, 



OMzcdoyGoOgle 



Sec. III.— Soda. 

1. Names.— The caustic soda was always, and is still unknown 
to commerce ; Bociently, the carbonate was called natron, Datrum 
and nitrum, whence the nitre of the Scriptures. It is mentioned in 
the Bible, as a detergent, and as disagreeing (efiervescing r') with vin- 
egar ; both of which qualities belong to the carbonate of soda, but 
neither of them to nitre. In Africa, they call it trtxia ; on the shores 
of the Mediterranean, soda and barilla. It has been called tnaiine 
and mineral alkalj. The tenn soda is now universally used. 

2. HisTORT. — Indicated by Geber, an Arabian chemist, in the 
ninth century, but confounded with potash till after tlie middle of the 
last century ; and unknown in its pure slate until the discovery of the 
carbonic acid. Effervescence with acids was formerly considered 
as characteristic of soda as well as of the other alkalies, but it be- 
IcHigs to them in the state of carbonate only, and not in the pure state. 

3. Points or sihilabiti between it and potasba. 

(a.) Their history is so nearly the same, that it is necessary only 
K) mdlcate the difference. 

^b.) All that respects the preparation is identical, and their prop- 
erties are very similar. 

4. Soda obioinates from *HARATi>n; and marine pionts, the 
algs fiici, salsola soda, ix. : the plants are dried, burned and lixivi- 
aKd, and the lixivium evaporated to dryness. The crude soda of 
commerce, called barilla, is the incinerated salsola soda: kelp, a 
coarser variety, is the incinerated sea weed, and often contains only 
from 2 to 5 per cent of alkali ; white good barilla contains 30 per 
cent- The crystallized carbonate of soda of commerce is obtained 
either from the calcinalton of the sulphate with charcoal and chalk in 
a reverberatory furnace, or by decomposing the muriate of soda by 
carbonate of potash. — Vre. 

5. Properties. 

(a.) Caustic toda it at firtt deliqaeMeent in the air, lilce poiatta, 
but unlike that alkali it never runs into the consistency of an oOy fluid ; 
for it soon becomes efflorescent, from combinadon with the carbonic 
acid contained in the atmosphere: a change which potash never un- 
dereoes. 

(S.) Caustic soda is in the form of gray sub-crystalline masses, 
which can scarcely be distinguished from potassa, by the eye or by 
any sensible properties. 

6. 1^ force of attraction in soda for the acids, is inferior to thai 
^^ potassa: the soda salts are decomposed by potassa. 

' Salaola ii t maratlme plinl, (i. e. it grows on the >ea shore,) b 



D„tiidD,Googlc 



252 ALKALIES. 

7. Soda with oil forma hard soap — polath toft; and soda is p^v 
haps a little less caustic than potassa. 

8. Distirtctice characters. 

(a.) It rorms different combinations with acids ; for insiance, the 
sulphate of soda is very soluble in water ; that of pMash the oppoute. 

(6.) Its salts, suspended upon platinum wire, imparl a rich yellow 
color to the blowpipe flame. — 7\imer. 

(c.) Muriate of platinum and tartaric acid give no predpitates with 
salts of soda: the opposite is true of potssh. 

9. Uses and importanck. — Soda is scarcely inferior in this re- 
spect to potassa : in soap and glass making it is largely used, and It is 
preferred for the finest articles. In the form of carbonate it is much 
used in medicine as an antacid: in medicine the caustic soda, is not 
used, having no advantage over potash. 

10. The dittintium of vegetabh and mineral* aUcaUum^ounded; 
for both are found in plants, and botli also in stones and various min- 
erals. Still it is true that potash is found in most plants, and soda in 
those only whicli are connected ivith saline sources ; on the other 
hand, solid mineral salt, the ocean and other saline waters, and the 
soda lakes and incrustations, present great quantities of that alkali in 
the mineral kingdom.f 

11. Polarity.— Li the galvanic circuit, soda goes to the negative 
pole, and is therefore electro-positive. Its combining weight is 33. 

Remarks. — In commerce, we never see caustic soda ; in its pur- 
est form, in the shops, it is always in scnii-crystflUinc masses of car- 
bonate, called sal soda. 

The purest fossil alkali, obtained from the efflorvescence on plaster 
walls, contains about GOj of its wcif^lit of alkali in crystals. 

Alkali manufactured at Liverpool, - - - 49 

Fossil alkali from India, - - - - 28 

Best Alicaut Barilla, - - - - 26i 

Sicilian Barilla, ----- 23 

The richest Kelp, made in Noruay, the Orkney Islands, 

and Skye, - . . . - 6i^ 

The general produce of Scottish Kelp, - - 2iJ 

There arc associated with the soda in sea-weed, muriate and sul- 
phate of soda, hydriodate of potash, or soda, and portiwis of lime, 
magnesia, silica, and alumina. There is also more or less of suU 



* Fotnih wai formerly cMei the vcgclalilc olknU, xnd win Ibc minGral. 
t Ai felipar, which ronMlluloa ro large n propDrtlon of granite, whose detritu 
mu » considemblc part of onriwrtls, rr>n1ain«. on sti averaae, al leant 10 percent, o 
turn, lliis alkali may anvr all lu iiioie aliuii'tjiit than aoJa.— J. T. ud C. U. S. 
t Blacfs Lcel. 



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ALKAUE9. S53 

phur, which is oflen to a degree separated by ihe efflorescence of 
the soda,* in the form of carbonate. 

When soda plants are made to vegetate away from saline sources, 
the quantity of soda constantly diminishes, and eventually they affi>rd 
only potash. — Murray. Although soda is separated from ils com- 
binations with acids by potash, it exceeds that alkali in its power of 
neutralizing acids, in the proportion of 4 to 6, or 2 to 3, its equiva- 
lent being 32, and that of potash 4S. 

Mode of aicertaining toe proportion of real alkaii in the loda 
of Commerce. 

Take sulphuric acid of the specific gravi^ of 1.10, which is gene- 
rally prepared by mtxbg one pan, by weight, of the best acid of the 
shops, with six of water. 

Pulverize finely, an average sample; take, say 100 grains, and 
add to it 2 oz. measures of pure water, agitating it occa»onally, for 
a few hours; after subsidence, decant, add more water, and again 
allow tbe solid matter to subside ; decant again, and filter the fluids, 
and lastly, wash the solid residuum on a filter, until the water drt^s 
tasteless, and no longer afiects the test colors. Mix the different 
fluids, and concentrate them, by boiling, to the volume of 2 or 3 oz. 
measures. In a vial of known weight, place 2 oz. of the acid, sp. 
gr. 1.10, and then add it cautiously to the alkali, till efiervescence 
ceases, and the test papers are no longer altered. Sulphur will be 
precipitated. Now see how much acid remains. It having been 
ascertained by previous trials, that 100 grains of dry alcoholic potas- 
sa, require 520 grains of the acid, of the sp. gr. 1.10, for saturation, 
and that 1 00 grains of alcoholic soda require B12 grains of the same 
acid, it is easily calculated how much real alkali there was in the por- 
tion subjected to examination. Trial is made also, for potash, and 
the test used is muriate of platinum ; tliere will be a yellow precipitate 
if potash is present; otherwise none. If muriate of potash should 
be suspected, since the muriate of platinum detects aU the salts of 
potash, it may be knovrn by adding a little sulphuric acid to the alka- 
line lixivium, when tlierc will be fumes of muriatic acid gas, if the 
muriate of potash i5present.f 



1. Discovert. — By Sir H. Davy, at the same time with potas- 
sium, October, 1807. 



* Mr. Parkes. in hisessavfi, nieolinns llial some iletlen refiinelo buy the dSoreH' 
ced cirbonsle of soda. Ihlnking il lo he >pailc<l, ivliereasit is really in a good degrci 
puritied. 

t Parkes' Chcm. Esaays, Vol. II. 



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3. Modes of obtainiko.— The same as tbose described for po- 
tassium ; only the decomposition of eoda is more difficult, requir- 
iog a higher voltaic power, and in the process by the furnace, a 
greater degree of heat ; a mixture of potash and soda is more easily 
decomposed, and affords an alloy of the two metals. 

Dry muriate of soda or chloride of sodium ia decomposed by po- 
tassium, with the aid of heat, and sodium is evolved ; it is done in an 
iron tube. 

3. Pbofertieb. 

J a.) Exiremdy timdar to ihoie of potfunum. 
h,) Rather more tolid at the common temperature — under napilia, 
liant Uke »tver, and quite as white. 

(c.) ^ery malleahte ; by pressiu-e of a plabna blade, a globule j\ 
or TT °^ ^n ^^^ '"^ diameter, is made to cover | of a square inch, and 
this property does not diminish even when it is cooled down to 32°. 

{d.\ Several globi^ea, by strong prejtvre, unite into one, and it is 
iherelore capable of being welded at the common temperature, while 
iron and platinum require full ignition. 

(e.) /( merely floats on water; the sp. gr. at 59° Fahr. is sup- 
posed to be 0.972, water being 1. 

(/.) Lest fusible than potasiium ; softens at 120'^, is perfectly 
flui^ at 180° or 200°, and readily melts under naptha. 

{g.) Vttporixabh, but at what exact temperature is unknown, for 
it does not rise in vapor at the fusing point of plate glass, but is dis- 
tilled at an intense heat. 

(A.) Tarnished by common air, but not by air arti6cialty dried, un- 
less heated in it. 

(\.) Heated to fusion, it burnt with tdntiUations and white flame. 

(J.) On water, it melts, appears like a globule of floating silver, 
ana wastes rapidly away, but without emitting light, unless the water 
be hot, when it scintillates and flames ; there is no combination of the 
sodium with the hydrogen evolved by the decomposition of the wa- 
ter, on the surface of which it has a rapid motion, owing to the causes 
mentioned under potassium. It burns in chlorine gas with bright red 
scintiltations, and muriate of soda is the result. When plunged be- 
neath it, it decomposes water with violent effervescence, and a loud 
hissing noise ; soda is formed, and hydrogen evolved, but there is no 
luminous appearance. On moistened paper, or in contact with a 
smalt globule of water, as there is nothing to carry off the heat, the 
sodium usually inflames. The action on alcohol and eiher, is the 
same as that of potassium. In the action of sodium on the oils, 
and on naptha, on sulphur, and phosphorus, on mercury and sev- 
eral other metals, there is almost a perfect similarity with the ac- 
tion of potassium. The soaps are of a darker color, and less solu- 
ble ; the combination with sulphur, (effected as in the case of potas- 
sium in cbse vesseb filled with the vapor of naptha,) is auended with 



DK;,lz=..,C00g[e 



ALKALIES. 3S5 

very vivid light, and much heat, and often explosion. The amalgam 
of mercury and sodium seems to form triple compounds with other 
metab; Sir H, Davy thought that the mercury remained in combina- 
tion with iron and platinum, after the sodium was alkalized, and sep- 
- arated by deliquescence. The amalgam forms a triple compound 
of a darlc gray color with sulphur. 

Oe.) Ii^ma on the itroi^ adds, forming salts with soda for a 
basis; the nitric acid, as usual, acts with the most energy. 

4. Oxides. 

(«.) Protoxide. — Sodium combines spontaneously mth oxygen re- 
producing soda,* but its attracdon for oxygen appears to be less en- 
ergetic than that of potassium ; the process is slower, and the deli- 
quescence of the alkali produced is not so rapid. The combination 
is accelerated by heal, but combustion in oxygen gas does not take 
place till near ignition ; it then hums beautifblly with a white flame 
and bright sparks, and, in common air, the flame is similar to that 
from burning charcoal, but much brighier. Sodium heated with so- 
da, is said to divide the oxygen between them, producing a deep 
brown fluid, which, on cooling, becomes a dark gray solid, and at- 
tracts oxygen, again from air and water. f 

The protoxide is produced also by burning sodium in dry common 
air, ihe sodium being in excess, or by the action of water. This 
protoxide is caustic soda; its color is gray, fracture vitreous, does 
not conduct electricity, fusible at a red heat, combines with water, 
with great heat, and produces hydrate of soda, which is white, crys- 
talline and more fusible and volatile than before. Its constitutioQ is* 
1 proportion of sodium, ... - 34 

1 " oxygen, - - - - g 

And the equivalent of anhydrous soda is 3S 

It combines with water, as already remarked, with great energy, be- 
coming a hydrate, and the water cannot be expelled by ignidon. 
The constitution of the hydrate, 

I proportion of protoxide, 32 per cent. 22 j water. J 

1 " water, 9 

41 

(A.) Deultmde of sodium. — Bum sodiinn in an excess of oxygen 
gas, or heat the protoxide in that gas j the protoxide is always fbrmed 



"Thifliippeiiii, or course. It it ii not c*r«AiIly kept; I IitTeloit manetoTKidlam 
io thii mtuner; the mclil turni ioto white ctuatle M>di. and cTeutually efflarMcep 
In the fonn of eirbonile, »t the nme lime enltrginf ll> volume vary much. 



OMzcdoyGoOgle 



Srst, and then more oxygen is absorbed, and the peroxide is generated . 
The color of thia oxide is yellowish green or orange; it is fusible j 
ft non-conductor of electrici^, and when thrown into water, it gives 
out its excess of oxygen. 

Its composition according to Davy, is sodium, - 75 

oxygen, - 26 

100 
Its constitution is stated to be 1 proportion of sodium 34, and 1} 
of oxygen =13=36, but as this introduces a fracdon, it is probable 
that our knowledge is not precise. 

The peroxide acts upon most combustible bodies with defiagration. 

According to some, die peroxide is composed of two proporti(His, of 

Sodium, ------ 48 

Oxygen 3, =24 

72 would 
then be its equivalent or representative number ; of the truth of this 
view, there seems to be no direct proof. 

5. Powers of combination. 

They are very extensive, like those of poUssium ; to which how- 
ever it yields an energy of affinity, as is evident in the case of the 
decomposition of common salt by potassium. 

6. PoLAHITT. 

Like potassium, it is attracted to the negative pole in the galvanic 
series, and in this way it was first discovered. 

7. Dirrusioir. 

Sodium exists very extenavely in the carbonate, sulphate, muriate 
and other forms of soda salts ; it is found in some plants, especially 
marine ones, and in many stones and rocks. 

Remarks. — The great prerogative of sodium is to attract oxygen, 
in which function, it is inferior only to potassium. Both these re- 
markable bodies are endued with such a degree of activity, and their 
chemical relations, are so numerous, as almost to realize the brilliant 
suggestion of their illustrious discover,* that they approach to the char- 
acter of the imaginary alkahest of the ancient alchemists. Their dis- 
coveiT has placed in our hands new means of iovestigation, and of 
beautiful and splendid experimeut. Nothing could be more unex- 
pected, than that common salt and sea weed should contain a metal, 
or wood ashes another. In the present slate of our knowledge, we 
must regard potassium and sodium as elements. As they exist 
abundandy in minerals, we can understand how, in the processes of 



OMzcdoyGoOgle 



vegetable life, they should bec(»ne coDsthuent parts ot [Jants. It has 
been akeady stated, that hydrogen hits heen supposed by some, to 
be one of their constituent principles ; a suggestion which is coun^ 
tenanced by their levi^, and by the fact, so contrary to what is found 
to be true m most other cases, that their oxides are heavier than the 
metals vbicb they contain.* 

Sec. IV. — LtTHiA. 

1. Name. — From T^of, a stone, or XtJiioc, stony. 

2. DlBCOVEHY. 

Detected m the year 1 8 1 8, by Mr. Arfwedson, in the petalite, which 
contains from 3 to 8 per cent. ; in the triphane or spodumene,f there 
is 8 per cent, and in crystallized lepedohte, 4 per cent. ; it has been 
fotmd also in the green and red tourmaline, and in several varieties 
of mica. 

3. Process. 

(a.) Fuse the powdered petalite, 1 part, with carbonate of pot- 
ash 3 parts, dissolve in muriatic acid — evaporate to dryness — digest 
in alcohol, which takes up the muriate of lithia and Utile else ; this so- 
lubon is evaporated to dryness, and the residuum again dissolved in 
alcohol, which gives the muriate pure ; it is then digested with car- 
bonate of silver, to form carbonate of lithia ; this being decomposed 
by lime or barytes, gives pure hthla, which must be evaporated to 
dryness, away from the air.l 

(6.) Another process by Berzelius, is as follows : — Mix 2 parts of 
fluor spar, and 3 or 4 of sulphuric acid, with 1 of powdered petalite 
or spooumene, and apply heat till the acid vapors, consisting princi- 
pally of silicated fiuonc acid, have ceased ; thus the siLca is remov- 
ed, and the alumina and lithia unite with the sulphuric acid, in the 
form of sulphate ; that of alumina is decomposed, and the euth pre- 
cipitated by boiling with pure ammonia. Ignition expels the sul- 
phate of ammonia, and the pure sulphate of Itthia remains, which is 
easily converted into the carbonate, and the carbonic acid being ex- 
pelled from this, we obtain the pure hthia. 



1, lod Nxla of mtgne- 
na mud nUtogea. 

t Id the jpodumsiui mil petalite, the lithU U cambimd with silica and alumlnt ; 
but in the lepldolite and In the lithioa mica, it E* ettmbioed alw with potataa, tad to 
ktM coottniiDition with thla alkali, (ha lithia ahould he prepared Inun the (podn- 

t For ot 



J cy Google 



tm ALKAUE9. 

4. PROPBBTICS. 

(«.) Color wbite ; not detiquetoeiit, but sbsorbs carbonic acid bf 
raposure to tbe air, and beooioee a cariwnete- 

(i.) Very soluble in water, but less eo tbao poUsn Bnl soda, aad 
MW^ety soluble at sU io alcohol ; acrid, caustic, acts oa etion n 
the other alkalies do. * 

(c.) Heated with platinum, it acts on the metal ; place on platinum 
ftul, with a small excess of soda, a piece of a lithia mineral as large 
as a pin's head, and heat it with the blowpipe for two minutes ; a dark 
color or dull yellow trace appears near the fused alkali, and tbt met- 
al is oxidized by aid of the lithia and the air, while It is not affected 
under tbe soda. The soda, by combining with tbe other princijdes 
of tbe stone, liberates the lithia. 

{d.) Lithia has a higher neutralizing power than potassa and soda, 
w even than magnesia ; its phosphate and carbonate are sparingly 
Boluble, its chloride is deliquescent and soluble in alcohol, and &is 
solution bmns with a red flame ; all tbe salts of lithia pve a red 
oobr when heated on a platinum wire before the blowpipe. '* Ulhia 
if AstinpiiBhed from the alkaline earths by forming solunle salts widt 
sul{Aunc and oxalic acids," and the carbonate,* although drfficultlr 
soluble in water, stains tunneric paper brown. rDie muriate and ni- 
trate are deliquescent; the concentrated lithia salts mixed with a 
strong sohitioH of carbonate of soda, deposh carbonate of Ktbia.— 

Some of these properties have been mentioned in anticipation, and 
Mhers are omitted or reserved for their more appropriate place. 

6. Decohposii'ioh. 

The metallic base was evolved by Sir H. Davy, by galvanism, but 
h was KX) rapidly oxidized to be collected ; and the metal was, bow- 
ever seen to be white like sodium, and burned with bright scimiHa- 
tioBa- Composition supposed to be — Hthium, 56.50, oxygen, 43.50 
= 100.00, or by Dr. Tbomson^ lithium 10, which he supposes to 
be ke equivalent number, sad oxygen 1 proportion 8=18, for the 
equivalent of the alkaH. 



OMzcdoyGoOgle 



itMl 



UXX BAXTTA BTBOinriJL HAONCSU 8II.I0A ALOWIHA 8I1O- 



Ijitrodvclory Remarks. 

Id die plan of this wcvk, and in connexion with the alltalies, some 
objections have been stated to the prevailing mode of arranging most 
of diem, and all the eardis, under the metals. A^th respect to tbe 
eardis, this course, though highljr inconvenient, would perhaps be 
somewhat less So than in relation to the alkalies ; but I decidedl;^ pre- 
fer to preserve the old division of earths, notwithstanding the mter- 
esdng discovery that most, if not all,* of them are raetaUJc oxides. 
Here, as in the case of the fixed alkalies, there can be no diScul^ ia 
pursuing the analytical course, by proceedmg from the compound to 
US principles, — first describing the earth, and then iu compoflitkm ; 
ana reverting again to the metallic bases of the earthy when wa 
come to die metals. The great advantage pressed in pursuing this 
course isi that we are, as early as possibte, put in posseenoo of li 
knowledge of the properties of these important bodies, aod that dw 
natural order of earths wiH remain unbroken ; for, as Dr. Ure (Ditrt.) 
very justly remarks, " whatever may be the revotuOona of obemical 
nomenclature, mankind will never cease to consider as earths, thoso 
sohd bodies composing the mineral strata, which are incombustible, 
colorless, not convertible into metals by all the ordinary methods of 
reduction, or when reduced by scientitic refinements, possessing but 
an evanescent metallic existence, and which either a]one,-or at least 
when combined with carbonic acid, are insipid, and insoluble in 
water." 

Nearly the whele crust of our planet is cornposed of these bAdies ; 
for, the combustibles, and alkalies, and the metals, jntiperiy so caH^if^ 
form butaverv smidl proportion of the whole. Nine bodies hare been 
diatH^ishsd by chemists, to which the name earth has be«n ^veo ; 
they are, as enuraerated at tbe head of this divisioD, I^me, Baryta, 
&KHitiB, Magnesia, Silica, Alumina, Gludsa, ^Srconia, sa4 Yvsm. 

The three latter are of little consequence, euher in a eci^itific or 
practical view, and seem chief^ important in determinmg the god- 
stitution of some few gems, and of a few other minerals, most of 
them rare. Of tbe remauung »x, the most abundant is silica ; linae^ 
is in this re^wct, the next ; then follows alumina, and dien m^neais f 



OMzcdoyGoOgle 



these four esrths coastitute the great mass of our mountains, rocks, 
stones, gravel, and sml, and were the five others annihilated, it would 
not sensibly diminish the volume of the crust of the globe. Bar3rta 
and strontia exist, however, b some quanti^, and barj^, especially 
combined widi sulphuric acid, is of frequent occurrence, although it 
is generally confined to veins in the rocks. 

As chemical reagents, lime and baryta are of signal utility ; stron- 
tia possesses similar properties, but has, in comparison with those 
earths, httle that b pecuUar, or that gives it a ground of preference. 
Silica, alumina, and magnesia are of limited use in scientific chem- 
istry, but they are of vast importance b the arts, and along \nth 
lime, are the foundation of the vegetable kingdom, and of agricul- 
ture ; as our best soils consist of di^rent proportions of these earths ; 
and the varying qualities of soils, although modified in an important 
degree by moisture and by animal and vegetable matter, ana other 
causes, are characterized chiefly by the predominant earths. 

The preceding sketch has been presented, that the student miebt 
not fail to obtain a just idea of the important natural order of earths, 
which it is difficult to define by unexceptionable chemica] characters ; 
but there is no difficulty in giving clear discriminations, provided we 
divide the earths into groups.* 

The divbkms under which the earths will be described, are — 

1. Alkaline earths. 

3. One earth of a sub-alkaline character. 

3. Earths proper. 

AX.KALI»E EARTHS. 

LIMG ^BABITES STBONTIA. THEIR GENERAL CHARACTERS. 



ia.) Soluble in water, but much less so than the alkahes. 
b.) Acrid and caustic; in light powder, irritate the nostrils, and 
produce sneezing. 

(c.) Test colors afiected by them, as by the alkalies. 
[d.^ Differ &ora the alkalies in their very difficult fusibili^, butfii- 
sble Dy the compound bk>wpipe, and by galvanism. 

* Perh^M the only chinclen thit will strictly ^pl; to them ill, uv Ihon— 
I. Tbey ire, when prepared pure by irt, nfalte poixlen.— S. They ire not volilUe 
bj heat, uid are remarkably diSicult lo melt, and are, both when pure, and whea in 
codibtoattoa with each other. In the ilanei >nd rocks, the most luHjuble and unalter- 
■U* bodiea that are f^nerally knowo to maoklnd, — 3, Thty have oxygen ibr a com- 
n<n prlodplt, united, in each earth, to a peculiar metallic or combuUlble baae. It 
b tru* (w iunested by l Mead,) that some or the proper metallic oiidea, would be 
covered by Iheae «hir*ctart, e. g. the oiidei at eohiinbium, lltanltiin and ceriun; 
liut Btlll, Bcetof ourardficlat divMrau, bil of rigoitMia evactnen; r 

MHea gnduata Into the adds, but iw one for that re ••-<-<- -' 

Here can be no good otgeellan to dividing the ni 
vaniant orien, which are alio in a great m 



OMzcdoyGoOgle 



g: 



EARTHS. 361 

I Not volatile by any heat hitherto applied. 
) Form soaps with oils. 
„ ) Id common mih the other earths, combine with adds aod 
form sails.* 

EARTH OF A HIXED CRARAGTER. NAllXLT, UAONtStA. 

(a.\ Not acrid or caustic. 

(b.\ Applied in substance, affects the vegetable colors. 

ic.) Nearly insoluble in water, but absorbs it. 

(</.) Equally difGcuIt to fuse as lime, not volatile. 

(e.) Combines readily wiih acids to form salts. 

If.) Combmes indirectly with oils to form soap. 

KARTHS PROPER. aiLIC A ALUMI N A— GLD C I N A—ZIRCONl A 

TTTRIA.-f- 

Destitute of alkaline properties, except that 
(a.) They unite with acids, and form salts; silica combines per- 
manently with only one acid ; i. e. the fluoric. 

2(b.) Insoluble in water ; but most of them absorb it. 
) Tasteless, innoxious, inodorous, 
(d.) No effect on test colors. 
V»y difficult to melt, but less so than the alkaline earths ; 
e alkalbe earths are powerful fluxes of the earths proper, and 
of common metallic oxides. 
(f.) Not volatile by heat. 
i^,) In their pure state, do not combine with oils to form soap. 

Sec I. — Lime. 

1. Discovert. — Familiarly known from the remotest ages. 

2. Preparation. 

(a.) By thoroughly igniting, in a good furnace, m a covered cm- ' 
cibie, small fragments of marble, chalk,^ or shells, or other pure cal- 
careous carbonate of lime, (Carrara and Parian marble are prefer- 
red,) these substances lose half their weight or more in the form 
of gas and water, and if fiilly calcined, they will not effervesce whb 
acids. 

(6.) As the natural carbonates of lime are not always pure, we 
may dissolve them in dilute muriatic acid ; then add ammonia, which 



' EvBDalllcaciHiibliief pennuiently with floorle add, lad trauiently ind riigfatlj 
with loine other leldi ; thii nrth diflcn in MTor^ ropects Ihiiii the rett, and mue 
h>vB even ragirded II u in icld. 

I It if Ktirrsly neoMtrj to rerouk (h»t Thorina, which wu tnnrianll; admll- 
ted unonE the eerlhi, hu been bgnd la be i mb-pIxiiFhate of Vttria. 

t CbalE ii tba itxt pun of the three. 



OMzcdoyGoOglc 



will precipitate the mtgneiia and aluiaiiM, and not the lime ; we tfcen 
decompose the filtered solution by carbwaie of potaeh, and the pre- 
cipitated carbonate of lime, after being washed and dried, is decom- 

esed by a strong heat. Common good quick time, that has not 
eo air slacked, answers every purpose for demonstrating the ptty- 
perties of lime. 

3. Properties. 

(a.) Color, white, and the masses recendjr from the furnace are 
rather hard, but brittle. When diy, not active on the animal organs, 
but if moistened, lime acts as a caustic ; taste astringent and alkarme. 

(b.\ Specific gravity 2.3. 

(c.) Soluble in water: writers vary in stating the proportion, be- 
tween 450 and 778 parts of water for the solution of 1 part of lime, 
or 55S for the hydrate : 500 is the number heretofore adopted ; pro- 
bably 700 may be near the truth ; but it appears that only a weak 
lime water is obtained by using water at 31^, which dissolves tynly 
ttVi of th* fitn^i *!<' bIt of the hydrate, while at 320. Accor- 
ding lo Mr. Dalton* and Mr. R. Phillips, it takes np ^ }j, or nearly 
double, and when the sdtitton is heated, It becomes troubled, and 
lime is deposited. These facts are not in accordance with the gen- 
era] laws of solution when it is aided by heat. 

(d.) Lime teater: its taste is acrid and disagreea!^, and it {ffodu- 
ees uMB (est colors the e^cts of alkalies ; it is not however caustic, 
and there is so litde of it contained in the water that it may be swal- 
lowed with safety, and often with advantage. It is a valuable reagent 
and medicine ; it is prepared by simple solution of lime, in water ; it 
must be preserved in close bottles from the atmosphere,f otherwise 
it precipitates as a carbonate. 

{e.) Lime waterX m made to t^ord eryriei$, if placed in a vacu- 
um, under the receiver of an lur pump, the evaponiion being aided 
- by sulphuric acid, ccratained in another vessel^ the uocess is gradual, 
and depends on the same principle as the coogelalioQ of water 1^ 
the same laeans^ (see page 116.) The crystals are traasparent 
hcxahei^, and we true hydrates, containing lime, 76.36, water, 
33.74=100.00.1 Lame wat^ imsn an imperfect soap with oiL 



* Add. Phil. N. S. I. 107. 

t Place in ■ clean carbojr, a qaaDltty of good hjidrata of lime ; lill the veaeel with 
rain water; a^tale it, viA aliow the lime loaubiide Dreroighl; It ivlli lie dlaaolTed 
■■ out (Mrdk at in hetir, lod in lbs momfaig i( may Im inmtt off cleaj by a Kjfiitm, 
or filtered Ikrougb paper if It ia (Taaltd immediately ; If tke cock ba good, and the 
water la Dot allowed to freeze, the nme arreDgomeot, iddlDg water tntm ttoM W 
lima, will atwwer far year*. 

t Add. de Chlni. et da Phya. L SSS. 



OMzcdoyGoOgle 



(/.) Sl4iddag 0/ ttne.— In thie fiunffiar proceK, ifae etrtfa com- 
bines mth about one third of its we^ht of water, fcaming a. true b7- 
dnte; and id this condhioD, iiioe kept secluded ftom the air, is in the 
roost useful state for the laboratory. The wbKt may be again expel- 
ted by a red heat, cmtrajy to the fact in the case of the hydrates of 
polassa and soda, and of baryta and strontia. The heat, (about SOO**, 
Dalton,) arises irom the solid iiication of the water, and is much more 
than ihe latent heat of the water, because ice or snow and lime slack, 
mth energy, and give out a heat of 212". Light sometimes appears, 
when the slacking is performed in a dark place ; I have seen it from 
the Carrara marble.* If fragij^eDts of good lime be placed in a quart 
tumbler, filling not more than one third of it, the tumbler resting in 
8 dish, the proper quantity of water being sprinkled over it, and a tall 
beB glass covering the whole, Ihe vapor will rise in a dense cloud ; 
it win soon produce currents like rain, down Ihe sides of the bell, which 
will become clear, as soon as it attains the boiling heat, and the steam 
will then blow out powerfully under its sides: when the bell is Ufied 
out of the dish, the cold air will again produce a thick cloud. 

(g.) MilA or cream of Ime,, is the hydrate brought to the oonsiit- 
race of paste with water, and thus mechanically suspended : it is 
very useful in purifying gases from carbonic acid ; they are, for this 
purpose, made to pass through the milk of lime, tba large quantity 
of the earth being much more etlectusl than time water, which is how- 
ever, ve^ convenient in small experiments. 

(A.) lAiM M mechanically raued in ilaeking, as is perceived by 
the odor, and by the efiect on test paper, placed in the steam that ri- 
ses from iL 

(i.) Ume abiorhi moitture from the air, falls to powder, and he- 
comes a true hydrate. f 

(J.) 1^ mere wata-'tlacking of lime doe* Ttal dcMtrotf iii acliviijf f 
its peculiar powers are blunted or suspended by air^lackbg, the cauae 
of which will be explained under the histmy of the carboDate. 

4. FiJsiBiLiTT. — Extremely infvt^le; first partially mailed by 
Dr. Hare's compound blowpipe, in Philadelphia, and in 1812 more 
perfecdy, in the laboratory of Yale College.]: The lime must be 
shaped into the form of an acute cone, not over the ^ze of a large 
pin, and the focus of heat must be directed upon the apex ; when it 
softens, subsides, and is soon covered with a vitreous ^aze. Fumble 
also in the galvanic current. The light emitted by lime, in the focus 
of heat, is most intense ; it has been used with a stream of oxygen gas, 



* In a cliirk cellar. In Mr. Accuin'!! house, in London, some lima of CariiT* mar- 
U«, during its ataekinc, aluwed laiiilooua (HKala oT inilil while Ughl. 
\ II iln abaorba carlnnic acid, and lone* iU cauatldly. 
! .^fterwarfiby SirH. Bary, \iy Gatvaulam. 



OMzcdoyGoOgle 



S64 EUtTHS. 

directed through the flame of ao alcdiol lamp, for the purpose of 
producing a signal light, which can be seen at a great distaoce. 

5. PoLARiTT. — ^It is attracted to the negative pole in the galvanic 
circuit, and 19 therefore electro-positive. 

6. Combining weight, 28, as will be seen more parliculaily under 
calcium, the basis of Ume. 

7. Pbabkacedtical pkepaoation. — ^Tbis Is the same that has 
been already described in giving the process for quick lime. 

cIlciun. 

1. Discovert. — In 1808, in Sweden, by Prof. Berzelius and 
Dr. Pontin ; afterwards obtained by Sir H. Davy in England. Th6- 
nard attributes the first observation to Dr. Seebeck. 

2. Process. 

(a.) A cup or capsule, made of moistened lime, or sulphate of 
lime, containing a globule of mercury, is placed on a metaUic dish ; 
the negative wire of the galvanic battery of 100 pairs, in good action, 
is made to touch the mercury, and the positive wire is brought in 
contact with the under side of the metallic support. An amalgam of 
mercury and calcium is formed, but the process must be continued 
a good while in order to obtain any manageable quantity ; in a small 
(green*) glass retort, or tube closed at one end, this amalgam is dis- 
dlled, with naptha, which rises first, then the mercury, and the cal- 
cium remains in an atmosphere of vapor of naptha, for which nitro- 
gen may be substituted. 

(6.) When potassium, in vapor, was passed through quick lime 
heated to whiteness, the potassium acquired oxygen, and became 
potash, and a dark gray substance, with metallic lustre, was found 
imbedded in the potash, and it was evidently calcium, more or less 
perfectly reduced, because it effervesced violently in water, and 
formed a solution of lime. 

3. Peroxide. — ^This is formed when oxygen gas is passed over 
lime ignited in a tube ; the exact proportions are not known, but it is 
supposed to contain twice as much oxygen as the protoxide. 

In the moist way, the oxygenized water of Thenard forms tlie same 
peroxide. 

4. Properties. — tAttle inovm. 

(a.J Color, white, hke that of silver, and with the same lustre ; 
^ks m water. 

(6.) Ignited in a tube in which the distiUation of the amalgam was 
going on, it took fire when the lube broke, and burnt with an intense 



J cy Google 



EARTHS. S6ft 

whhe Hgfit, into quick lime. When the unalgBin of calcium was 
thrown mio water, hydrogen gas was erolved, and lime water re- 
mained. 

(c) Lime is the protoxide of calcitun. Its oomposition is cstima- 
Md by Beraelius at calcium, 71.73, oxygen, 28.27=100.00. 
Tbenard says, ihat it ought to coniaio hy calculetioD, 39 of oxygen> 
&. Its BttDivALXNT wKioHT IS Stated at 20, and therefore, 
oxygen being 8*, lime, or the protoxide is represented by 3S. 

6. Poi.AUTr. — Electro poatiTe ; it goes to the negative pcAe in 
the galvanic series. 

7. Uses or Lixx. — They are numerous and Important. Id med- 
Ktoe, the caustic earth is not used, except to prepare lime water ; 
in the solid form, tiie purs earth is too acrid for intemal use ; it 
was formerly used as an escharotic, and ita caustic properties are still 
employed in removing the hair from skins, preparalo^ to tanning- 
It IS almost constantly used in the laboratwy ; in the form of lime 
water, it is an important reagent, and we have seen that it is emi^oy- 
•d to disengage the alkahes in a caustic state ; it is largely used for 
the same purpose in soap making. In a word, it is of great value in 
medicine, in architecture, in agriculture, and in many arts. 

Mnrtar is a mixture of sand, or gravel, or both and lime ; in the 
proponkms of fine sand 3 parts, coarse sand 4, quick lime 1, recent* 
ly slacked with as litde water as possible. 

It is well to add some pulverized Hme, that has not been slacked ; 
it absorbs water, and solidifies the other bgiedients. Roman mar- 
tar was made of the same materials as the modem, but of the best 
quality, and accurately proportioned ; time has done much to give it 
hardness. According to Pliny, tlie Romans made dieir best cement a 
year before it was used, so that it was partly combined with carlxMUc 
acid before it was laidJn the work. In oM Roman stwie buildings, 
the stone will often break as 80c»i as the mortar. 

Another recipe for mortar. — Fine sand, 3, brick powder, 3, (well 
baked,^ slacked lune, 3, unsladked lime 2. If very litde water be 
used, toe mortar sets the sooner. Burnt bones, not exceeding <»ie 
fourth part, improve the tenacity of mortar. 

Manganese and puzzolana cause morlar to harden beneath the 
water. Puzzolana is decomposed lava, and ctHisista of silica, alu- 
mina, and oxide of inm. The mortar for the Eddystone light-house 
on the S. W. coast of Cornwall, (Eng.) was composed of equal parts 
of slacked hme and puzzdana. 



■ For TI.7S : 28.IT ; : 100 : S9.4 ind 39.4 



OMzcdoyGoOgle 



366 EARTHS. 

Manganesian and ferruginous limesiones are valuable in thia respect, 
and a portion of silica and alumine in the composition of the Unoe- 
stone improves it for these purposes.* 

Recipe for uiater mortar.f — Blue clay, 4 parts, manganese, 6, 
limestone 90, and all in powder ; calcine, mix with sand 60 parts, and 
form it into a mortar, trith water. The tarras,^ used for the con- 
struction of dyi^es in Holland, is merely an ancient decomposed lava 
from the cKtinct volcanos on the Rhiiie ; some call it a decomposed 
basalt, and it is certain that the rocks of this family, are efiectual in 
this way, if previously decomposed, or calcined, so that they can be 
broken down and intimately mixed with the lime4 Parker's ce- 
ment is composed of silica, 22, alumine, 9, oxide of iron and manga- 
nese, 13, carbonate of lime, 55 = 99, and there was in the analysis a 
loss of 3.25. The white cement used in New Haven to cover stone 
houses, is composed of the best slacked lime, 1 part, by measure, 
and from 3 to 5 measures of coarse siliceous sand and some hair, 
well beaten together, and laid on with a trowel ; the workmen pre- 
tend to add sugar, and various salts, pariicularly the sulphate of pot- 
ash ; but having tried the mortar, both with and without tliese addi- 
tiogs, I am persuaded that they are of no importance, and that tbe 
cement of coarse sand, hair and Ume, alone, will stand any length of 
time, provided water does not get beneath ; if it does, the first freez- 
ing will crack the mortar, and throw it off. 

lAme it of great use tn Agriculture, — In the form of carbonate of 
Ume, it is often mixed with soils, and will be mentioned again. In 
the statO' of quick lime it is largely used in England, where it is com- 
mon to see extensive tracts covered with heaps of it. || It appears 
to be a part of the food of plants, as it is found in the ashes of most of 
them, and it may be also a stimulus to vegetable life. Its immedi- 
ate action, when caustic, is to destroy vegetable organization, and it 
appears to act as'a manure, principally by decomposing hard dry 

• Hydraulic Mae of the lUic of New York, conWln* according to Dr. Hadley'i 
enelvHs.certwnic ecid SS.OG, time aS, ailex IS.DS, ulutnjae 16.0B, nUtr 5.03, oxide 
of iron 2.02.— Jm. /mo-. Vol. IIl.p. 2ttl. 

t Hydraulic lime la found al Soulhington, Conncr.licut, near the caiml, and io 
many places OD the Erie Canal.— See Am. Jour. Vol XIII, p. 38Z. 

t The proportioDS laid (o be used !□ Holland, are tarns I part, uid aliclced lime t 

§ I aan thern preparing the trap rocka In thli manner, at Greenock, where (1B06,) 
they wer« making hydraulic morUr for a dock. The poroun and veaicular trap 
which Ihcy uied wa» from the neighboring isle of Arran. That in Eaat Haven, 
which I] crumbly, lod u*ed for mending the ronds, and the vesicular trap near 
Hartford, (aee Am. Jour. Vol 'XVII, No. 1,) would in all probability aniwer the 
nme puipora, and It may be found of the aame character In many other places In 
our trap reglooa. Tha more veaieular, and the more decomposed It ia, Uie better, 
becRiiM it u the more eaiily pulverized by calcination and grinding. 

II Extensively und in Pennaylvulia, and highly valued. — J, G. Not much ui«d 
la New England. 



£AItTHS. 207 

v^et^le fibres, and thus rendering them soluble ; even tanner's bark 
is decomposed itj lime, and rendered useful bs a manure ; it is thought 
to be iDJurious with animal manures, unless they are too rich, and 
need to be in part decomposed.* 

Sec. n. Bartta. 

Name from the Greek jSapufi, heavy. f 

1. Discovery.— By Scheele, in Sweden, in 1774; formerly 
confounded with lime. 

3. Process. ' 

(a.) Native, or artificial carbonate, m powder, mixed with lamp- 
black and oil, in a hall, is strongly calcined in a crucible, for one 
hour, by the heat of a forge or vrind furnace, and the carbonic acid 
is thus decomposed, or expelled. Boiling water dissolves out the 
caustic earth. The theory of die process will be rendered more in- 
telligible hereafter. 

(6.) By calcination of the nitrate of Barytes j see that salt. 

3. Phoperties. 

(a.) Color, gray before slacking; consistency, porous ; after slack- 
ing, a white powder ; sp. gr. 4. 

(b.) Taste acrid and caustic ; poisonous. 

(c.) Affecu the test colors, as Ume and the alkalies do. 

{d.) Tfte hydrate itfitsible in its own water, of which it contains 
about 9 or 10 per cent. 

(e.) Baryta, even when obtained from the nitrate, is fVinble by the 
compound blowpipe .| 

(/.) Water catitet it to tlack with much greater energy than 
lime ; the phenomena and theory are the same, but much mora strik- 
ing, and light is said to be sometimes emitted.'^ The water slacked 
baryU, is a true hydrate, and as the earth is represented by 78, and 
there is one proportion of water in the hydrate, the equivalent num- 
ber is of course 87. 

Cg.) It slach in the air, as lime does, and for the same reason. 

(a.) It diiiohej readily in 20parU of water at 60°, and if boil- 
ing, in 3 parts. 

(t.) On cooling, it forma regrdar crystaU — flattened hexagonal 
prisms. 



t TIm natural sulphate ii knowD to the miDCra, by the Dtma of fauTv tptr. 

t RiupeclBble authora ttate that barvta thiu prtpartd u ir^vtibit, I ' 

had probably not tried the compound bluw-pipe. 



I The obwriation U atuibuted to Dobereiuer, and it nill not appear ttry exlraor- 
dliury, Nuce lime (oroeilmes eihlbitc light while aUcking, tltbrnigli the tD»i%y of 
Hm aetlOD i> much leu remarkabJe. 



DK;,lz=..,C00g[e 



(j.) They contain, according to Dahon, TO per cetU. of taaUr, 
and lose 50 by ignition ; their constitution is, according to due aaMoe 
author, baryta 1 proportion 78, and water SO proporooosor ISO, and 
thor equivalent number is 258 ; they mehin their own water, or sufiw 
the aqueous fusion ; after ignition, the dry powder which remains, 
slacks BgEUD with great energy. 

!k.) Crystals soluble in I7i times their weight of water. 
/.) Burning alcohol, although it does not dissolve this earth, re- 
cdvet from the cn/itaU a yelloto tinge, but this is better exhibited in 
the flame of the compound blowpipe, in the focus of which, every 
form of baryta, not excepting the sulphate, exhibits this characteristic 
color in the most striking manner. 

(m.) Barytic water is a very tuefvl reagent; it should be kept 
slopped from the air, otherwise it is precipitated in the form of an tn- 
Boluble carbonate. It produces all the effects of the alkalies upon the 
test colors. 

(n.) Sotuiion of baryta forms a soap vsith oils; its salts also form 
soaps if mingled with aqueous solutions of alkaline soaps. 

(o.) Dust of the earth irritates the nostrils as it rises. 

4. PoLARiTi — electro-positive, it resorts to the negative pole of 
the galvanic battery. 

fi. CoNBtNiNQ Weiout, 78, the elements of which may be seen 
under barium. 



1 . Obtained in the same manner as caiman, uang Dative carbonate 
of baryta or the pure earth,* made into a paste with water, a globule 
of mercury being placed in a litde hollow made in its surface; the 
paste was laid upon a platinum trey in connexion with tlie positive 
wire of a galvaiuc battery, while the negative wire touched the mer- 
eury. The mercury is distilled off in the same manner, but it is very 
difficult to obtain the metal. f 

3. Pbofestikb. 

(a.) J^etal of a dta^ grey coior,X with less lustre than cast iron. 

lb.) Solid at the ordinary temperature, but becomes fluid below 
%onion. 

(c.) J^ear redness, rises in vapor, and acts violently on the glass. 



* Oiid« oT mercury may be iined in oblnitiini^ Uie mclili of the carlhi ; one third 
partU mixed wlA two thirds oT the earth, and galvuiized, whaa an aj ' 
Jbrmed with the metallic bau. 

t Dr. Clarke itatea thai he obtained ths metal from the nitrate, by the c< 
Mowpipe- 1 menlloned in the memoir publiihed In Bruce'a Jountal, ia IS13, that 
Ae meNIIie basse oTbolh baryta and ■irontl*, qipeired to me to be evrived, and to 
dart oat In bright adntillatioiu, nlien the earthi were Id the bene of (be biatroiBflali 
bat a* diey always burned away, I wa» not abia to collect tlie metala. 

t " WUte color, with mBtalllc luiire, having a renmbtance to Bilrer." — JUurrag. 



D„tiidD,GoogIc 



(d.) him; btemnet eovend with afibn<^iatyta,aniia'wmeT un- 
dergoes the Bame change ; efiervesces violently and evolves hydro- 
gen. If gently heated in air, it bums with a deep red light and be- 
ootDesbuyta. 

(e.) SmJa in water, and am tn nilpktine acid, although surround- 
ed by gas; hence its sp. gr. cannot be less than 2, probably over 3. 

{j.\ Flattened with difficulty by pressure. 

{£.) Cemtiiulion of the protonde, about 89.76, metal, 10.25 
oxygena= 100.00. Barium, 1 proportion, 70, oxygen, 1 proportion, 
8=78. 

(A.) Peroxide ok dectoxide. — Baryta, prepared by ignition of 
the nitrate, is placed in fragments as large as a hazel nut, in a coated 
glass tube, aiia heated to low redness, when it rapidly absorbs dry 
oxygen gas as it is passed over it and becomes peroude with ptolK 
ably two proportions of oxygen ; it is formed also by heUing ba- 
ryta in contact with oxygen or common air resting upon it, but in the 
latter case stxne carbonate is also formed. Concentrated baryiic 
water becomes filled with pearly plates of the deuloxide of barium, 
when oxygenized water, containing ten or twelve times its volume of 
oxygen is poured into it. — JTiejuud, 

Con^ontion of the peroxide. — Barium, 70, oxygen, 3 proportions, 
16=86 ; the peroxide contains twice as much oxygen as the pro- 
toxide. 

It has been found that the nitrate of baivta may be decomposed 
by heat with such care, that the deutoxide is left; it is done in a lu- 
ted pOTCelain retort, connected by a Welter's safety tube with an in~ 
v^ted jar of water. The heat is gradually raised to redness, as knig 
as nitric oxide or nitrogen gas is disengaged, and when tbey cease 
and pure oxygen comes, it is a proof that all the nitrate is decompos- 
ed, imd then the deutoxide will remain in the retort. — Turner. 

((.) The deuloxide of barium is scarcely sapid, it is grayish white, 
loses its excess of oxygen by an intense heat, and acts 71th the aid 
of the same agent upon various combustible bodies, and thus becomes 
a protoxide. In contact with hydrogen near a red heat, there are 
luminous iets from the surface of the deutoxide, but the water that 
is formed is all retained in the state of hydrate, and the baryta thus 
becomes very fusible. Boiling water causes the excess of oxygen 
to escape in the form of gas. 

{j.) This substance was employed, (July, 1818,) by Th^nard, for 
the oxygenation of water.* 

Baryta is poiionoiu ; its natural carbonate is employed in Lan< 
cashire, (Eng.) as a ratsbane. 



9, VI. 1», 879, VUI. 114, IM. 



OMzcdoyGoOgle 



370 EABTHB. 

Pure baryta is useful to the cbemist as a test, puticularljr fw the 
discovery of carbonic acid, either free or combmed. Its muriate is 
used by physicians in scrofula, Sic. The sulphate is the most abund- 
ant form, and it is convertible into every other, by certain processes 
which will be mentioned in their proper place. 

3, PoLARiTi — EUetro-potitive ; it resorts to the negative pole in 
the galvanic circuit. 

4. CouBiNiNG wEioHT, 70. — ^This is the number of Dr. Thom- 
son. Berzelius states it at 50.66, but the former number is gene- 
rally adopted. 

Sec. in. — Strontia. 

1. Nahe. — From the lead mine of Strontian, in Argyleshire in 
Scotland, whence the minerals containing it were first brought 

2. DiscoTERT. — By Dr. Thomas Hope,* then and still, professor 
of chemistry in the Univ. Edin. Anno. 1791. 

3. PaEPARATioH. — The same as that of baryta.f 

4. Pbofebties. 

(a.) The result of the igneous decomposition of the nitrate is a 
gravidi porous substance ; sp. gr. approaching that of baryta. 

\b.) With leater, slaaki violently, like baryta and lime, and the 
theoi^ Is the same ; the powder of the dry substance irritates the 
nostrils and lungs. 

(c.) ^er tlacking, no more water being used than is necessary, 
the earth remaint in the form of white ptnoder ; it is then a hydrate 
C«m«3ting of strontia, one proportion, 53, and one of water 9=61. 
TTie hydrate fuses readily at ignition, but is not decomposed by the 
strcoigest heat of a wind furnace. 

{d?) More water being added, ii distohet in about 40 parts ; if 
die water be boiling hot, it dissolves in 30 parts of that fluid, and crys- 
tals are formed on cooling, having the form of thin quadrangular 
plates, sometimes square, oftener parallelograms, not over i of an 
inch in diameter.^ 

(e.) After being heated, the dry earth remaining, is about 32 per 
cent. ; the crystals contain 1 proportion of earth, 52, and 12 of wa- 
ter, 108=160. 

(/.) At 60°,soluble in 51i parts of water; boiling water ukea up 
halt its weight. 



* Dr. Cmwfbrd observod i difference belween Ihe murUtle of ritootU uid thtt ot 
buTli.inl790. Klapiothconfirmed the viewsorDr. Ho|ie. 

i Vide EdlD. Tna». IV, 44. 

t Id txMh cues, Ihe decDnpoaition of the (ulphala ii the cbeipeit pracoa ; ue the 
•rtielei lulphtle of birjta tod lulphale of itrande. The Gui>oiitt« ii muiaged 
with the rrealeit cue. 



OMzcdoyGoOgle 



EARTHS. 271 

The composidoD of the hydrate of strootia according to Dalton, is 
1 proponioa of earth and 12 of water. 

(g-.) Slrantia imparts to thefiame ofhoHing tdcohol, a Uood red 
color; its effects on [he test colors are the same as those of baiyta. 
lime, Su:. 

(h,) No union with 6xed alkalies or baryta. 

(i.) Heat readily separates the waier from the hydrate, and from 
the crystals. 

(/.) Tke compound blovipipe melts the earth itself,* with the char- 
acteristic red flame. , 

(k.) This blotepipe produces a similar Jlame from every conAiaatWR 
qfstr&ntia, even from the native minerals. 

(L.) DisTiNCTiTB CBARACTERs— cannot be confounded wiih any 
thing except barj'ta, but it is lighter than that earth, less caustic, and 
attracts acids less powerfully ; the strontitic salts being decomposed 
by baryta, produce difierent combinations wiih acids, are less poison- 
ous, and give a difieruit colored flame. 

5. Pd-ARiTy. — Like that of baryta, electro-positive, and of course 
it is attracted to the negative pole in the galvanic series. 

6. Combining weight, 53 — composed of strontium one propor- 
ti(H),44, and oxygen one, 8=53. 

STRONTIUlf. 

1. Obtained from native carbonate of strontta, by the same pro- 
cesses as those vihich afford barium; discovered by Sir H, Davy, in 
1806. 

3. Properties. 

(a.) Similar to those of barium ; has less lustre ; difficult to 
fuse } not volatile. 

(i.) Action of air and of water, converts it into strontia ; in wa- 
ter, it produces hydrogen gas. 

(c.) Proportions of the constituents of the protoxide. 

StronUum, - 84.54, or 1 equivalent, 44 

Oxygen, - - 15.46, or 1 " - 8 

100.00 52 

3. Thi dectoxide or peroxide of strontium is obtained in pre- 
cisely the same manner as that of barium. According to Th^nard, 
(II, 314,) it is best obtained by the action of the oxygenized water, 
or deutoxide of hydrogen upon strontia ^ater; the peroxide of 
strontium precipitates in brilliant pearly crystals. This oxide, by 



■DMz.d5yG00g[e 



heat, even th«t of a lamp, gires up its excess of oxygen, Hod becomes 
protoxide. It acts like the nitrates upon biiniinK coals, causing in- 
creaaed combustion. When it is moist, it gradually loses the oxygen, 
and rapidly in hot water. It appears to contain just twice as mucb 
oxygen as the protoxide or stronda. 

4. CoMBiNiNO WEIGHT. — This IS estimated at 44. 

fi. Po[.4BiTT. — EUctro-poiitive ; resorts to the negative pde of 
ihe galvanic battery. 

6. Uses, &c.-— Strontta has the same uses in chemisuy asbaiyti. 
It b a test for carbonic and sulphuric acids ; as a natural production, 
it b more rare, especially its carbcmate ; its sulphate is found abund- 
andy in Put-in-Bay, Lake Erie ; at Detroit, Macidnaw, Lockport, &c. 

The salts oi strontia are not p<nsanous ; the pure earth is acrimoni- 
ous UlcB the other alkahue bodies. 

The natural and artificial ccunponnds of baryta, are hearier tban 
those of stronda, and there are various points of diffiirence found in 
their combinations. The nitrau of strontia is used to ^re a bkxid 
red color to artificial fire works.* 

Sec. IV.— M aonbsu. 

1 . DiscoTEKT. — In the beeinnbig of the eighteenth century, ex- 
posed for sale as a panacea at Rome, by a canon, who called it pow- 
der of Couot Palroa ; but Dr. Black, m 1755, was the first person 
who distinguished it clearly jrom other substances. 

5. Prefahation. 

(o.) In the arts. — From the muriate and sulphate of magnena, 
found in sea and saline water ; they are decomposed by alkaues, or 
usually by their carbonates ; magnesia may be extracted by acids from 
magnesian stones, and the salts thus obtamed can be decomposed as 
above. 

(&.) la Chtmittry. — Ignite the common carbonate of the shops, 
or dissolve the sulphate and decompose it by any alkali or alkalme 
carbonate, wash thoroughly, and ignite the precipitate. 

3. PnOPXKTIES. 

fa.) In light spongy masses, or in a friable powder, which ftMins 
wiui water a paste destitute of cohesion; the carbonate is commcMily 
seen in cubical cakes. 

(A.) Sp. gr. 2.3; ttiB the caka Jloat awhile on vxUer, till they 
are filled by absorptioo. 

(c.) Tatte intipid, or slightly earthy ; lime mixed with it some* 
times communicates to it a slight degree of acrimcxiy. 

{4.) Mild, harmless, and without corroeive action on the living or 
dead animal organs. 



J cy Google 



EARTHS. 273 

(«.) Ag%tU the noet ddicate tett fiaifiai tfmaxd mtk Me» <A 
tuittoMce* e. g. cabbage infusion, violet tincturG, and ibat of tur- 
meric ; but it is not sufficiently soluble in water, to impart the same 
power to that fluid. 

' ") Does not dock mth uater, 

I Nearly insoluble in diat fiuid, vfiicEi takes up about -j-^j ii 

^andat313°5TtT»-t 

(k.) Ahtorht water, ao that 100 beoomea, in weight, 1 18 ( heat 
4rive8 tba water off, and the ma^esU contracta inin. It bnm a 
hydrate with water, but tt unites with this fluid wilhoat tity eenJ:^ 
1)0(11, and it is easily driven off at ^nibaa. 

(t.) Precipitated from acids in the state of faydiate oonliiimn^ 
^robabW ooe third water. 

(j.) This hydrate, dried by a very gentle beat, is tranqMmt: it if 
supposed to contain 1 equivalent of magnesia 20, and 1 of water, disSS. 

(it.) Native hydrate, of Hobdceo, New Jersey, contauu about 30 
per cent, of water. 

(l.^ Alkalies do not combine with magnesia; alkaline earths unilo 
wim It by heat. 

(m.) Of vert/ digieuU fiuion; first melted by Dr. Hare's blow- 
pipe, m the laboratory of Yale CoUege.J 

(fl.) Those minerals m which it is a large ingredient, are verj 
infusible ; hence soapstone is used in furnaces. 

(o.) With lime, in excess, it melts in liimaces } for the line, al- 
though itself infusible, acts as a flux. 

4. PoLARiTT. — A^tgneaa goes to the negative pole, and is there- 
fore electro-positive. 

5. CoMBiNiNQ WEIGHT. — Theory estimates it at 20; of which 12 ii 
assigned to magnesium and S to oxygen, being 1 proportion of each. 

6. CuA&ACTEHiSTics. — Its sulphate is veiy soluble, while ibf»Q 
of lime, baryta and strontia, are very insoluble : its nitrate and mu- 
riate are very deUquescent,^ and soluble in alcohol : the bi-carbonates 
of potassa and soda do not precipitate it, on account of the carbonic 
aCid.JI Oxalate of ammonia, which readily precipitates Hme, does not 
precipitate magnesia, if the solution is moderately diluted.— Turner. 

7. Uses, — Afagneaia is a very useful article of the materia medica; 
it is used as an antacid and cathartic. It seems however to be near^ 
iDOperauve, unless there is acid in the stomach, « unless acid is 
taken after it: all the salts of magnesia are bitter end cathartic. 

* Probably Uiii oBeet i«, ia some cases, owing to the lact, thit (h« alkali uwd In 

icoiDpooing (he macQeuan sail liai not hean p "'" ■' ' ' ""'"" 

I Fyla. quoted by Hcury. 

t Con. Acad. Tram. Am. Jour. Vol. II, p, 290, 

i Tbe nltratu of lime ia deliqucaccnt. 

J The Bune Is true, in a good decree, oT time. 



OMzcdoyGoOgle 



The carbonate is most coiDnioDlf used, but the pure eanh, sold un- 
der the name of calcined msgneda, is aoroetiffles preferred, because 
BO gas b extricated from it in the stomach. Magnesia sometimes 
forms large and dangerous accumulations in the bowels, of several 
pounds weigbt, pajticularly when its use has been kmg perserered 
m, and the earth has not been duljr evacuated, by acids, forming 
with it saline combinattona. It sometimes enters into the days, and 
otber materials which go to form porcelain, in the fabrication of 
which, on account of its inftisihility, it serves a valuable purpose. It 
is one of die fbur earths which form a lai^e pan of the crust of this 
planet. Soapstone owes its peculiar properties to magnesia, particu- 
nriy its infosibility : magneaan stones, such as soapstooe and tak, 
are much employed, not only to rmsi fire, but because they are so 
eaaly wrought by tools into any desred fbrm.* They are used m 



eaauy wra 
biiildiDS> 



MAOmSIUH. 



I. O&^oined in the none way at the other metah of the eSihi. 
3. A white and brilliant soLd ; (a little mercury still remglning io 
combination with it.) 

3. Sinki rapidly in waier, although surrounded hy bubbles of gas. 

4. Both m air and voter reproduce* fftaffoetxa; in air gains 
weight, as the balance proves, bodi with respect to this and other 
earths. 

5. PoLABirr.— Magnesium goes to the negaave pole, and is there- 
fore electro-positive. 

6. The comluning weight is estimated by Dr. Thomson at 13, and 
this, with 1 proportion of oxygen, forms magDesia^ which is the only 
fcnoWta oxide of magnesium, whose equivalent is of cuirse, 30. 
There can be no doubt that raagneaa is a metallic oxide. Hithraio 
chemists have been unable to make it absorb more oxygen. 

Sec. V.-^SiLicA. 

I. Njjek. — SSex w ihe Latin for jkat, wb'ch is composed of Ati 
euih, nearljr pure ; lim{Md rock crystal is almost pure sihca, and sev- 
eral otber siliceous minefal^ as chalcedony, camelian^ opal, ^ate, 
&c. consist prmcipally c^ this earth. The purest white sand contains 
fittle else: in the form of quartz it ccHistilutes moontais inaase^ Rod 
in that of sndstoue vast strata. 

* ftonfs ■■ttoni ire aequtfaitad wllh Ibew uwi : mwy ot their coottilDlDK vw- 
ttk, cwdiUr Tonto br cookery, >ra nude of Ohm mioeraii. After the kborf- 
fhwa of lUs tovatrj became acqutinted with the Europemu, Ibej nude bullet 
Moaldiif loeMfaiM 1 tbsy were IngeDiuiulj' arrwi^ f d hdvu, witb a rcfular mouth, 
•ml were ilM together bjrurltbes; I have mieh a ipBdiseD. Soap itoiM li kbo UMd 
MdiBiiiUiMetiaaiiim>ehkMry.-^jM. Jmr. VoL XIV, i^ S7&, 



OMzcdoyGoOgle 



EARTHS. 37S 

3. PKEPABATIOtr. 

{a.)Flint or rock cryital, ignited, thrown into water, andptUvcr- 
tzea, tiffbrdt tiUca mffidaitly pvrejbr every common purpott. 

(6.) But the more correct process is, to mix thaepowdert with 3 
or 4 partt of carbonate of potiuh or toda,* and to mdt the mixture 
in a crvable, gmog a higher heat, for half an hour or an bour, to- 
wards the last, and stirring it to prevent overflowing.f 

{c.) Caiutic potath or loda tt, ofcowie, more energetic in ito oc- 
^n, but is more expensive ; there is however bd advaDtage b u»ng 
caustic alkali, as it does not intumesce ; if a idlver crucible is used, 
it should be thick, that there may be the less danger of tneltiog it. 

id.) Dissolve the melted alkalino-siliceous mass in water, filter, 
add d3uted muriatic or Eulphuric acid as k»ig as precipiiaticRi 
continues ; the acid must be added in excess.^ 

(e.) 7^ tolution was formerly caJUd liqnor MUieum, liquor of 
flinti; the vitreous mass from which it is obtained is deliquescent, 
and ii^ the solution formed from it is dilute, and the add is added 
fgf^Aa^y, the alkali may be saturated without precipitatiDg any of the 
silica, I)ut by evaporation to dryness the silica is rendered insoluble ; 
the sah formed by the alkali may be dissolved out, and the eardi thus 
obtain^ pure aft» ignition. 

{f.) If the pra^i;tiotis of alkali and earth are reversed, then the 
compound produced is glass ; of which mention will be made again. 

3. Pbopebtiks. 

fa.J WhUc,in»i^kanh. 

((.) JN% t^ect on tat colors, no causticin', w any alkaline proper- 
ty, except its imion with a ansle acid, the fluoric. 

(c.) Water does not directly dissolve sUica, nor is it absorbed by 
that earth, but when jX' is newly precipitated, it retains 26 per cent. 
of water, at lOf^ Faht. 

((f.) When dry it is insoluble in water, but when just preci|»ta- 
led, it is dissolved by that fluid, in the pn^xnlion of about tv'tv>^''''<1 
and if taken in its nascent state,|| it is even largely dissohred, and a 

■ Diy petritrftu will do. 

t It H racoauMDdad to dknlve tba ■Ikali Gnl, in h llltle water aa mav be, to mli 
R with lb« •Ulcii, avaponCe to drjmen, and then Tum It, which may be done In • 
^Iref crv^bla. From my own experience, I ahould however recominend caulioo 
Id dw uae of dlTW vmwIb, aa they melt at about the decree of heat which produ- 
c«B Ibe oombfnatkin between the afllca and the fixed ilkdl. 

t Dr. Hear; remaib, " the alkalioe liquor miut be added lo Ihe acid, and not the 
MTotM ; lor. Id the latter caie, the preclj^wte wtll be glua and not alUca."— Val. 1. 
p. Ml, lOfh td. 

§ Found Datorally dinolved, a* in the Geyaera in Iceland, In which the folution 
la aided by loda, contained In the water : In the ilmllar hot bmitalui of the Aiorei, 
ilUca if imind In Bolutlon, he. there are natural hydraten, and the Inmenae nuh- 
berof ayalalB of qoarti, evince that Mlex has been in aolulioo on a great scale. 

D ParticuJariy when the mlphuret of liliciuin a dinolved in water, uid the dHca 
i* regenaratcil by the oxygen of that Uuld, while iti hydrogen ia •« olved, conbined 
widi aulpbur. 



OMzcdoyGoOgle 



bulky gelatinous hydrate is obtained, by a gentle evaporation : it is 
decomposed at a common temperature, but entirely at ignition. I>r. 
Thomson,* has shown that there are several hydrates (rf silica. 

(e.) Iiuolubie in acids, except the jftwrin, which attacks it Wilh 
great energy. 

(/-) Wfutn rteioly precipitated, tfdvhle to tome extent, in severed 
acxdi, and readily forms triple sahs. Dr. Marcet recommends to 
precipitate it with muriate of ammonia. 

(«■.) Specific gravity 2.66. 

(X.) Injiuible w any furnace, but readily mehed by the compound 
blowpipe ; this was done originally by Lavoisier, with ojrygen gas 
directed upon burning charcoal ; afterwards, and often, by Dr. Hare, 
and in U)e laboratory of Yale College :f it forms a perfect glass. 

(A.) SUica, minutely divided, u dissolved at a boiI%ng heat, by cava- 
tic fixed alkali ; the alkali should be twice the weight of the silica j 
after evaporation, the white puffy mass forms a dear solution with 
warn) water, as already mentioned under (e.) 

(t.) SUiea it hard, and when rubbed between two plates of glass 
wear? them so as to spoil their polish. 

4. PoLABiTT. — I believe it is not distinctly determined. Several 
chemists of eminence regard silica as being an acid rather thnn 
an earth. This opinion is founded upon the fact that it satu- 
rates die fixed alkalies, and that in its natural combinations, it sat- 
urates the other earths. It has therefore been called tiie silicic 
acid, and its compounds, siUcates. This however, appears to be 
» forced arrangement. In every other particular, silica is qiiite 
foreign from the nauire of acids, and as regards its combinations with 
earthy and alkabne bases, it is not uncommon for one oxide to unite 
with another ; the alkalies dissolve many metallic oxides, and potassa 
and soda readily dissolve alumina, and should therefore, upon this prin- 
ciple be called acids. The student will, however, do well to remem- 
ber that the silicates mentioned in modem hooks, and frequently in 
the analyses of minerals, are compounds ofsilica with bases. Wheth- 
er we regard silica as an earth or an acid, there appears no reason 
why these combinations should not take place in definite proportions, 
such as are actually found to exist. 

6. CoMBimNo wsiGBT. — According to Dr. Thomson, it is 16, 
of which one proportion is osygen, 8, and one alicium, 8. Accord- 
ing to Berzelius, it is I proportion of silicium, and 3 of oxygen. 



D,q,fzodbyGo(lg[e 



stLicimr, on silicon.* 

Remarks— Tix student may omit this head unlil lie lias sUidied 
tbe fluoric acid, and its compounds. 

]. PSOCEEE. 

(a.) Ifoq seven parts, silica five, and from } to J of soot, fused in 
s blast furnace, gave an Hioj of silicium and iron. 

(&.} Puri^ed potassium, when heated in silicated fluoric acid gas, 
buniB, condenses the gas, and gives a brown sujistance. 

(c.) This boiled in water, and dried, burns In oxygen ga£,.aud 
produces only ^icated fluoric acid, and silica. 

(d.) " The residue, treated witli fluoric acid, gave silicated fluoric 
acid, and its color was rendered much darker." 

(e.) " Thrown on a Alter, washed and dried, it was pure silicium, 
which may be obiained also by beating potassium in a glass Uibe,, 
wth dry silicated fluate of potash." 

(/.) " The product by being well washed with water, yields a 
compound of silicium and hydrogen, from wliich the latter may be 
detached by heating in a crucible.''f 

2. Properties. 

(a.) Color, deep nut brown, without lustre, and acquires no bril- 
liancy from a burnisher j no resemblance to a metal ; resists tHction 
like en earthy substance. 

Incombustible, in common air, or even in oxygen gfts.^ 



• Sir H. Davy, (as ttlrettdymentionert with reopect to lime,) by drivEnglhe poUsti- 
um tbrOQgh the entths heated iateDwIy, succeeded so Tar Id decompoaing aevcrnl of 
them, that the mass exhibited nelallic point*, ami the patunum became potuh. 
No coDsiderable niBues or metals were obtBined in this nay, but in general there 
wag tuffidenl evidence that they were decampoacd, and in this niaaner he was tho 
lint to aacertain thai allien ia a compound of oxy^n and a base. 

1 Atin. de Ch. et de Pbya. Vol. XXVII, 887— Am. Jour. Vol. IX,p. BT7.— Hon- ' 
ry, Vol. I, p. Wl, 10th Ed. 

The beat method of decompaalng allica, Is by taking it in the lorio or double flualc 
of iltica and potash or soda; the latter la preferred, beciuae it eoMalna the greatest 
quantity of silica. To prepare it, the, aqueous solution of eUlcal«d fltiorie acid b 
iDiied with the carbonate of soda, when the double salt, which is nearly insoluble, 
precipitates, and is washed aod dried at a beat above 313°. Tliis U slratiiied with 
thin slices of potassium, in a frloss tube, hermcdeally sealed at one end, and the 
mass must be uoUormly healed, and atonco, by a spirit lamp. E«eD bcGire isnitlon 
the silica ia reduced with a hissing noise, and some appeanuce of heal, but if tho 
matter Is dry no heat ia eyotred. 

Tho resulting brown mosa, after being thomugfaly freed frwa acid aad saline mat- 
ter, by water repeatedly applied, at first cold, and In abundance, aiHt at last boiline 
hot, is then Ignited, to cipcl hydrc^ea. It is tlicu washed in diluted hydio-lluoric 
acid, to remove any ailiceoua particle*, and is again washed and dried. For the de- 
t^ neo Ure'a Diet 2d Ed. p. 718, and Ann. of Phil, Vol. XXVI, p. UB. 

t When first obtained, and bolbre il is freed from liydrt^cn, it Inimn when licatcd, 
even in the open air, but if caiefully ijiuited firet, in scclusiuu from the air, to exiH'i 
the hydrogen, it becomes uiiinllainmatile. 



Dj.=.^Ct)bg[c 



S78 EARTHS. 

(&.) A«f aUadcedhy wafer, or Mtdpkuric, mtnc, or n 
acut. Ii^vnUe, and wudterobh by the biowp^ and apparently 
one of tbe most infusible of bodies. 

ic.) Fluoric add, with a little nitric, attacks it vigoroutly. 
d.) After iniidon, .chlorate of potash does not afiect it at any 
temperature. Nitre acts upon it violently at a white heat. If a frag- 
ment of carbonate of soda be introduced into the mixture, it detonates. 

(e.) Vapor of sulphur unites nilh the ignited silicium, and becomes 
incandescent. 

(/.) The resulting ^phuret decomposes water rapidly, and evolves 
sulphuretted hydrogen ; silica is generated, and the water dissolves 
it, and becomes gelatinous, but after it is diy, it remains a cracked 
mass, and is entirely insoluble in acids. It is observed that this solu- 
bili^ of silica just formed, may explain the existence of siliceous 
crynals in closed cavities, which could never have contained water 
enough for die solution of the materials, unless they were origmally 
in a much more soluble state. 

(g.) Smdiun burnt in chlorine at a red heat, and forms a yel- 
low volatile liquid, smelling like cyanogen, and depo»tmg silica on 
the addition of water. 

(A.) Detonates iMen heated viiih earbonaie of potash, and with 
the h^rates of fixed aUadtet, and o/*&aryta, producing at a tempe- 
rature below redness, vivid incandescence ; it acts upon the alkali 
of nitre, after the acid is destroyed by heat. 

ft.) A non~conduetor of eUetridty, 

(j-) Alloys of siHcium are obtained by heating silica along with 
other metats, but silicium once extricated from oxygen, does not form 
alloys. 

(k.) It stains, aJid sticks strongly, even when dry, to the glass 
vessels in which it is kept. 

(Z.) ^'Aen silicium is heated in vapor of potassium it takes fire, 
producing a compound of silicium and potasaum. 

Remarks. — ^It b not easy to class ^cium. It can scarcely be 
called a metal, as it is infusible, is a non-conductor of electnciiy, 
and has none of the physical properties of a metal. It may be re- 
garded as a combustible, since it burns in chlorine, and those who 
^oose to consider its combination with sulphur and potassium, with 
amission of heat and light, as a combustion, will of course add those 
balances as proofs of its combustibility. On the whole, it is perhaps 
nore allied to boron and carbon, then to the metals ; but carbon has 
."WO metallic properties ; it is a conductor of electricity, and in the 
!cHm of plumb^, and of fused charcoal, it has the metallic lustre. 
Some of the metals, as uranium, titanium, and columbium, are rather 



- See Ann. do Chem. ot de Pby>. Vol. XXVII, p. 3ST. and Ur«'i Diet p. 7W. 



OMzcdoyGoOglc 



EARTHS. 279 

remote in their propemes from those usually assigned to metab. — 
Berzdaii, 



1. HisTORT. — Known to the andentt. — Glass beads were fowul 
among the omamentB of mummies in the catacombs, near Memphiff, 
supposed to ba 1600 jrearB older than the Cbristian era ; glass was 
known to the Romans, and glass vessels were discovered in the bous- 
es of Herculaneum, and a coarse glass in the windows of the houses 
in Pompeii, which were destroyed by an eruption of Vesuvius, A. D. 
79 ; glass lachrymatoriea are found in the tombs of the ancient 
Greeks-f Glass was however, with the ancients, merely an article 
of hixmy and curiosity, and it is only in modem times that it has 
come into general use. 

In Europe, it was first made at Venice, and its use, In windows 
of private bouses, was introduced into England in the tenth century, 
nor was it commoD unci the 13m or 14th centuiy. 

2. CoHPosiTiOM. — EitentiaBy a eonmowtd if nitea, aad jixtd 
aUcaU, with however, various adventitious ingredients; sometimes 
glass is made of lime, or of the coarsest refuse ashes, and sand. 

3. Princmat kindt. — Flint glass ; crown, or window glass ; broad, 
or coarse wmdow glass ; plate glass ; green bottle glass. 

(fl.) Jf%U Glatt.^ — 120 parts clean, white sand, 40 piuified peari 
ashes, 35 litharge, or minium, 13 nitre, and a little oxide of manga- 
nese ; or 100 white sand, 80 to 85 red oxide of lead, 35 to 40 of peat) 
ashes, S or 3 of nitre ; or, (in England,) purified Lynn sand 100 parts, 
litharge, or red lead, 60, purified pearl ashes 30. To remove the 
color, derived from cmnhustible matter, or oxide of iron, a little nitre, 
or black oxide of manganese, or arsenic is added ; the oxigen c<hi- 
tained in these eubstances, either bums the combustible matter, or 
brings the metallic oxides that may be present, to such a state Uiat 
diey do not color the glass. The fuaon takes about thirty hours. 
He lead gives to this species of glass greater toughness and stress, 
so Ibti it can be cut, ground, and highly polished, and greater densi- 



■ul»luicM,ukdmatamcazIdM,BlIli«r(kDe,«r _, , ..,_. 

briltl*, dilningbodiei,a«iitll)rbi«akliigwl(b acMtchold*! Avetare, wnd having mora 
or leMoftmuparency. The riif uidaeortaoffaniaMitKimperlectvltrlfioitSnii. 

1 a — ■ Veaght out by Mr. Joom, lulbor of *• Niral Skatehea," lod 

tt ofVile Colleff ■■ •■ ■ 

■btde (rfcotor. 

t Callad fltnt gha, beeiiiM it wu fimnerlj nude rram fliad ; *t>d H hu been 
nllad ciT«t>l gl*M, being «>metimei mede [rom rock eryftali ; both wr« %afted end 
thrown iato irUer to cndc Ihcm, iiid tliej are then pulTorlzed. 



OMzcdoyGoOgle ' 



280 EARTH*. 

ty, and higbcr refraMive power. It is the glass of our tabled, of i^ 
tical instruments, and lustres. 

(6.) Crown Glass. — ^200 parts of good soda, (or pearl ashes,) 
300 pure sand, 33 lime, 250 to 300 ground fragments of glass ; this 
last addition is not essential ; or, by measure, 6ne sand purified 5, 
best kdp, ground, 1 1 ; by weight, sand 200, kelp 330. Professor 
Sweigger discovered that sulphate of soda m^t be used in the man^ 
nfacture of glass, and lus pfoponioos are, sand 100, dry lul^xie erf" 
soda 50, dty quick Ihna, in powder, 17 to 30, cbarcoil 4. The re- 
sult is a good glass ; the sulphate of soda, aided espetu^ b^ tlw 
c^TCoa}, is decomposed, and its soda combines with the ^lies and 
the fonc aids in producing the vitriGcatioR. fhn materials of glass 
are combined, in part, t^ a prelimisary operation, caBed Jritting-, 
performed in a Itimace, by whidi sulphur and oier volatile mat- 
ters are expelled, previous to the full iusion, and die aUta£ is brougfal 
mto combination with the silica, so that it is not vdattiiaed by a 
Uglier heat. 

(c.) Broad glast. — Soap maker's waste 2,* sand 1, k^ 1, mix- 
ed, dried and mttad ; or, soap boiler's waste, € buabels, 3 of kelp, 
and 4 of sattd ; these form a pretty good broad glass. Tbe materi- 
als are calcined for 20 or 30 hours before fonon, and then it requires 
JS or 1 5 botirs to raeh them into perfect glass. 

(d.) Plate glass — 300 lbs. sand, 300 soda, 30 lime, 33 ok. man- 
ganese, 3 oE. aeure, and 300 lbs. fragments of glass ; or pure sand 
43, diy soda 36.6, pure quick lime 4, nitre l.S, broken plate glaas 
35=100, from whicn 90 parts of good plate glass may be obtained. 

(e.) Bottle glatt, — Cotnmon sand,f 100 parts, 30 of varec a* 
coarse kelp, IGO leached ashes, 30 pure ashes, 80 of brick clay, 
tfbout 100 broken glass ; or, soap mtdcer's waste and river sand, in 
proportions determined bj practice. Common sand and lime, with 
some commou clay, end sea salt, form a good mixture for bottle glass. 

3. Ptistes are art^aal iimtationi of the genu. — They are very 
fine glass, rendered tusible by borax and other fluxes, and stained by 
oxides of metals. Rock crystal, or other very pure siliceous mat- 
ter, is sheeted, pulverized very 6ne, and mixed with the other sub- 
stances ; the following examples will shew the compoiQtion. 

Pulverized rock crystal, or flint, 8 oz. purified pearl a^es, 34 oz. 
these are fritted together, and then mixed widi 12 oz. of v^tetead, 



I In Enclaad, tbe gnveruniei: 
Ihu iiiauu^cluio, lent iJiu cuiuiqcid Huh b^iouIiI be it> good Ihtt the sale of Ihe fliaf 
utdotliereuperiar kiDiboTgltM, which pay a higher duly, iboukl be diminuhed. — 



DK;,lz=..,C00g[e 



s 



and 1 ot. of boru — after fusioo, 6 dracbnu of nhie are added ; or^ 
rock crystal pulverized, 3 oz., white lead, 8 oz., and borax, 3 oz.i 
aod half a grain of maDganese. This is a paste in which the lead 
and borax answer the pw^ose of a flux. 

Some principal colors are nren by the following oxides of metals^ 
Antimony gives yellow, and the same is produced by muriate of ^ 
ver, and ^ oxide of zinc, white clay, and yellow oxide of iron j 
manganese produces violet ; gdd, many ^ades of violet, red and 
pnrple ; cobalt, blue ; chrome, green, or red ; iroof redf and a greai 
many other cokirs and sliades ; and many varieties are imparted by 
mixtures of difierent oxidesi Fluxes far the colors are made of 
boraxf pearl ashes, lead, be. These imiutions of the gems, except 
in lustre, are often equal in beauty to the originals, but diey are 9on^ 
and easily defacedi 

{g.) Stained glau.--^Tiie art of staining glass was introduced into 
En^and, in the 13th century, in the reign of king John. Man^ of' 
the ancient Gothic churches in Europe, are om&mented by stamed 
lass, the panes of the windows having pictures painted tipon them< 
"le glass used for this purpose, is made without oxide of lead, be- 
cause that addiuon would make it loo funble, so that k wAuM lose 
its shape during ^e second heatings The colors, groimd in watery 
are laid on the glass, which is heated under a mnfflef imtil the caian 
are melted, Bnd united to the glass ; and the pieces, to prevent thw 
bending, are supported npcm the bisctiit of unglazed porcelam, or 
some other suitable substance.* 

(A.) Medt^wna eneattd tn ^lon.— They appear to be something} 
like the biscuit of porcelain introduced into the glass, while in fusion ^ 
tliey are called crystdllo ceramie, and are very beautifu]<f 

(i.) ETKmeh are glaues, mote of Itu (make, stained with various 
colors ) one of the most common is stained by oxide of tb or oxide9 
of tin, arsenic and lead more or less mixed, as in watch faces. 

Dr. Bigelow mforms us,} that the beautiful imiiation of porcelainy 
made in Boston, and now seen in the shops, is dint glass, containing 
a portion of white arsenic, upon which its opacity depends. 

Remarkt. — Oireen glass is much harder and less nisibte than white 
ffint, and as it c<»itatns no lead, it is also much 6tter to contain cot' 
rosive cbemica] agents. Glass is very ductile, as is proved by its 
being ^>un into the most delicate threads ; it is highly elastic, form- 
ing me finest toned bells and musical instruments ; it expands and 
contracts less than any other substance by variation of ten^rature^ 



boweTer, than the indent. 

t HoBib of Washington, FrnnkJin, Nipolenn, aoil olher disUngniihed peraona^ 
tevAbeenexccutedinihu way. t Technology! iW. 



OMzcdoyGoOgle 



3g3 EARTHS. 

and might thererore be used for clock pendulums ; it is a bad con- 
ductor of heat, and a large mass of it poured in fusion into tvater, will 
remain red hot in the inside, for several hours after the outside is solid. 

3. Mechanical opEBATioNa. — It would exceed the tiaiits of a 
work like this, to describe even the outlines, of the ingenious opera- 
dons hy which glass is fabricated into the various forms in which we 
see it. In general, it is blown by the breath of the artist, injected 
through an iron tube, to which the melted glass is made to adhere, 
by dipping and rolling one of its ends, repeatedly in the crucible ; 
and in the early part of the operation, while it is inflated, it is rolled 
on a smooth iron plate. I wiU briefly describe a few cases, most o( 
which I have seen, and they will serve as examples for the rest. A 
porter bottle is partly bk>wn, and then allowed to drop into a mould 
of copper, brass, or iron, in which, by a vigorous inflation, it receives 
its form ; the bottom is indented to make it stand ; the mould omss 
with a hinge, and another workman attaches a rod, having a liule 
melted glass upon it to the bottom of the botde ; die neck is cracked 
oirby touching it with an instrument wet with cold water, and the 
broken mouth, being again heated, is shaped by inuoducing a revtAv- 
ing iron into it, and a coil of melted glass is wound around to give 
it Btrengh ; it is then carried away to the annealing lumace, to be 
gradually cooled. Glasses consisting of several pans, are blown sep- 
arately, opened, moulded, shaped and stuck together while hot ; the 
foot of Q wine glass is blown, as well as the conical part. 

A glass tube is drawn, by blowing a little into a mass of melted 
glass on the end of the iron tube, and then an assistant pulb the mass 
with irAn pincers, and moves off rapidly or slowly, as the tube is to 
be coarser or finer. 

Plate glass is cast on an iron table ;* an iron cylinder of five 
hundred pounds weight or more, is passed over it to spread it 
smoothly, and it is finished by being ground and polished. Plates 
have been made of twelve feet by six. . The smaUer glass plates are 
blown, opened by a chisel and mallet, and cut, while hot, by shears, 
spread open upon a table, and afterwards annealed and cut by the 
diamond. . Pktes can be made in this way, of four or five feet, by 
two or three. Window glass is blown, and either cut open and 
spread ; or in the best kinds, after being blown into a huge globe, 
thb is l^xed at the bottom, to another iron tube, or rather -an iron 
rod ; the neck is cracked off, and the mouth is heated at a flaming 
furnace, while the bottle is made to revolve rapidly, and by tbe cei>- 
trifugal force, the moutli opens and widens, and the globe suddenly 
expands into a wheel, forty eight or fifty inches in diameter, called 
by die workmen, a table ; this operation is called jlaaking, and is 

* Copper UUIes awl rollerB were Ibrtticrly cinployci], but t)i« copper \$ apt ta 



OMzcdoyGoOglc 



very beautiful. The glass, after being annealed, is cut up into squares ' 
by a diamond ; llie centre piece by wliich the wheel was supported, 
is called the bull's eye, and is often seen in entry windows. Broad 
glass is blown into a conical form ; cracked longitudinally while liot, 
by touching it wilh a cold wet Iron, and it is then spread out on a ta- 
ble, whence its name ; it is afterwards annealed and cut. 

TVie anneaUjig of glass, which means ike cooling of it, very slow- 
ly, in a peculiar kind of furnace, it important to prevent its crack- 
ing by sliglit movements, or jars, or variations of temperature. 

Prince Ruperft drops are made by pouring melted green glass 
into water, when tl)e portions assume a tadpole shape ; ihey will bear 
the moderate blow of a hammer, if lying on a smootli tabic, but if 
the point ia broken off, they explode into a tliousand pieces. That 
this peculiarity depends on an unequal contraction produced by sud- 
den cooling, is evident, because if the drops are gradually heated red 
hot, and gradually cooled, they will no longer fly on liaving llio 
point broken. 

The Bologna vial is blown with a thick bottom, but is cooled in 
the air, without beii^ annealed ; it will bear to be struck upon a table 
with some force, but if a fragment of glass or sand be dropped into it, 
it flies to pieces, and frequently it does so by slight changes of tem- 
perature ; even, as I have observed, by Ihe warmth of tlie hands. 
Cups of green glass, unaiinealed, have been made three inches thick 
at bottom, which were not broken by a musket ball falling from a 
considerable height, but were shivered, by a piece of flint of two 
grains weight falling into them. 

Sec. VI,— Alumina. 

1. Nahe. — From alumen, the latm of alum, which has tliis earth 
for its basis ; called also the argillaceous earth. Indicated by Geof- 
frey, in 1727, established by Margraff, of Berlin, 175C. Formerly 
called argil, because it was the basis of clays. 

2. PKEPAKATION. 

(a.) To asoludoDofalura,* in 20 parts of water, add liquid ammo- 
nia till precipitation ceases : or, precipitate by bicarbonate of potash ; 
as a litde sulphuric acid is ant to adhere, it may be re-dissolved in 
nitric acid, and the solution tried for sulphuric acid, by nitrate of ba- 
rytes ; when there is no fartlier milkincss, it may again be precipi- 
tated by the above reagents, or die nitrate may be decomposed by 
beat.+ 

(6.) Or, alum purified from iron, by repealed crystallizations, is 
dissolved in 4 or 5 parts of water, at 212° j add carbonate of potash 

* Alum is apt lo Fonlnln iron, which 
the earth disMHved by potasBa ; or, if d 
ill brown flock*. 

< Ann. Ju Ciiim. XXXII, f. G4. 



OMzcdoyGoOgle 



Alumina enters more or less into die composition of most soils, 
and it generally forms strata in valleys and law grounds and plains, 
where it arrests the water which has filtered down from the hills, and 
causes it to issue from die ground, in springs and rivulets. On ac- 
coimt of Its impermeability to water, clay is employed in (he con- 
struction of Unner's vats, of artificial mill p<Hids,&u:. where jt is wish- 
ed to retain the water. 

In soils, this earth is of the first importance ; perhaps it is not too 
much to say, that there cannot be a good soil without it. Its pe- 
culiar office appears to be, to retain moisture, and to prevent the 
waste of die soluble parts of animal and vegetable manures, which 
so rapidly filter through siliceous sand and gravel. Still, a soil may 
contam too much alumina ; it will tlien be stiff, cold, and difficuldy 
penetrated by the roots of plants ; but if it is mixed with a good pro- 
portion of sihceous sand and gravel, it will be warm, still retentive of 
m(M3ture, and sufficiendy mellow. 

Lime is an excellent ingredient in soils, as will be mentioned more 
particularly under the carbonate of that earth. 

Alumina exists abundantly in rocks, especially in felspar, which is 
a constituent of granite and gneiss ; in clayslate, steatite, asbestus, 
and serpentines, and in a great varie^ of minerals. It is nearly pure 
in the sapphire, and all the most precious orienul gems ; it forms 
nearly the whole of corundum : it exists in b vast proportion of min- 
erals, and forms a laj^e part of die crust of the globe. 



PORCELAIN AND fOTTEBT. 



In all the manufactures which go under die general name of pot- 
tery, from the coarsest tile or water pot, to tlie most beautiful porce- 
lain — in chemical lutes, in fuller's earth, and bricks, silica and alu- 
mina, in certain proportions, are the essential ingredients. 

JRitory. — Known fi^im die remotest antiquity ; die most barbarous 
nations fabricate rude vessels of baked eardi, as well as by hollowing 
out soft stones ; bricks were employed in the tower of Babel,* two 
tliQusand years before tlie Christian era, and they arc found in the an- 
cient Roman structures in Britainf and elsewhere. Earthen lach- 
rymatories are discovered in the toinbs of the ancient Greeks and 



■ la Yale College, ire MDie Hahylaniah brick* broiif;ht out by ihe late Mr. E. 
Lowls, of N. Haven ; Ihcy were never bikcil ; they mntain ttraw anil hilumcn, nnil 
BOOM oflhcDi bavB " inscriptions in the arrow bcailoii chatarlet ;" llic dimeuMODS 
of the larf^at are In'olve andlhi'aa fnurthe inclics Hjuare by [Lrooand u liutf thick. 

I In Ihe Itoiiiiii wM al Vorlt, the hrirkH ure Arvriilrcn Inches long, cltivcii broiid, 
and two and a hair thick ; and Ihorc is in Yale VjtUesie, a piece of brick atid mortar, 
from Rouian balhi at Pui*, preiuiiled Liy Mr. Joel Uoot, who oblaioed it from the 



D„tiidD,Googlc 



EARTHS. 28? 

Romans ;* the celebrated Etruscan vases were found in the bNnbs 
of lower Italy, f 

Water pipes were made by die ancients. I have one from Smyr- 
na, sent out by the American mis^onarics, which indicates its anti- 
quity by numerous layers of carbonate of lime, accumulated in the 
tube to the tbicknesa of three or four inches, and evidently deported 
from the water which ran through it. 

The Egyptians ornamented the mummies in their catacombs, not 
only with glass, hot with earthen figures, some of which were co*er- 
ed with a blue glazing made by the oxide of cobalt, the same mate- 
rial that is now used for this purpose. Porcelain was made by the 
per^an, and other eastern nations, before the Christian era, and the 
art b of high antiquity in China and Japan. It was introduced into 
Europe, early in the late century, and fabricated first in Saxony and 
France ; it was established in England, about the middle of the 
late century, and the manufacture was brought to great perfecti<Hi, 
by the late Mr. Wedgwood.J The manufacture of porcelain has 
been within a few years, begun in the United States,^ and beautiful 
porcelain is now made at Philadelphia, by Hulme and Tucker. 

Materiah of poreelatn. — ^The Romi^ missionary, father D'En- 
trecolies, early m the 18th century, sent home some of the materials 
used by the Chinese, and called by them petuntze and kaolin, the 
former being undecomposed febpar, and of course fusible ; the lat- 
ter decomposed and infusible, in consequence of the loss of the al~ 
kali, which is one of its constituent principles. 

The felspar is composed of silica about 60 or 70, alununa from 
15 to 25, and from 10 to 12 per cent, of potash or soda. 

Porcelain differs from stone ware in having a vitreous fracture and 
delicate translucence, which arises from its being composed of one 
fusible ingredient, while the infusible one preserves the vessels from 
losing their form in the Sre. 

Porcelain clays abound in this country, and the materials from 
■Chester County, near Philadelphia, now used there, are of the first 
order in point of excellence. Such clays should be free irom iron, 
or the ware will be colored. 

Maierials of pottery. — ^Tbere is no diderence in principle between 
the materials of pottery and those of porcelain, except that the latter 

' Specimens uro in Yale CoUefcc. brouglit out by Dr. Howe ind Mr. Jone*. 
Some of Lbein iie Buppoaeil to be of (he age of Periclei, particularly those Trom Iha 
toisbf near Atheni. Dr. Howe Inrormod me that he wai preaenc when tbey were 
laken from Ihe lomhB. 

t 1 aaw a cDllectkm of these in the Briliiili miueum, scut out from Italy by the 
late Sir \Vm. Hamilton. 

( Tiie common pottery had lieen inaDuractur«d in En|;lanil, lime nut of mind. 

^ I beliuve tliat Dr. Meaile, of New York, wa» the fiist pefMD who nicc«edei)' In 
tbi* country in making true porcelain. 



D,„iz=. ./Google 



388 EARTtiS. 

contain one fiiuble iDgredient, and are purer. The pottery b^ng 
opake, needs not the felspar, and it has a dull earthy fracture instead 
<M a vitreous one. 

The most common earthen ware is made of pipe cisy, often con- 
taining iron, which of course colors the ware when it is burned. A 
clay, much used in this country, is obtained from Amboy, N. Jersey, 
and is gray, both before and after it is burned. 

The plastic property possessed by moist clay, and hy means of 
which it is moulded, depends on the alumina ; but the pieces would 
crack and be destroyed by ^rinkage, were not the alumina correct' 
ed by the silica, which is not prone to shrink in the fire. If natural 
clays then have the requisite proportions of the two earths, and are 
free from inm, they have all Uie propenies that are essential ; and if 
a color is j»'oduced by burning, it does not prevent the cl^ from 
forming a useful ware, eltbou^ it may not be beautiful. Magnesia 
frequendy enters into the composidisn of clays, and is a valuable in- 
gredient, as it is a very infusible earth, and contracts but little in the 
fire; but if there is much lime, it will act as a Hux, and produce a dis- 
torted ware. 

As the natural clays do not always contain a sufficient portion of 
siliceous earth, it is usual, in such cases, to mix with them siliceous 
sand or ground flints, the clay being first blended with water into a 
paste, and it is then uniformly mixed with the siliceous ingredienL* 

Fabrication of porcelain and pottery. — ^Thers are important dif- 
ferences between die two, and there are many varieties ot operauons 
relating to both, but a few general facts may be stated. There is no 
analogy between tbese processes and those by which glass is made ; 
tbey are in fact directly opposite ; glass is " softened by beat, aod 
wrought at a high temperature, whereas the clay is wrought whiJe 
cold, and afterwards hardened by heat." — 'Bigeloto. 

Tbere is much labor in preparmgthe materials, the detail of which 
would be foreign from the object of this work, in wluch only a few 
of the most important operations can be mentioned. 

Circular conical vessels are moulded upon the potter's wheel, a 
veiy ancient instnioient, mentioned by the earliest writers, sacred 
aod profane. A mass of the prepared clay is placed in the centre, 
and It revolves by a movement given by the foot, or by some other 
power ; the potter, bis hands being moistened, to prevent adhesion, 
one hand being on the outside, and the other within, gives it a clrcu' 
tar form, and he employs sometimes a rude instrument, like a knife, 
lo aid in finishing the piece. Many ardcles, modeled in this way, 
being too thick, are afterwards turned tn the lathe, to make them 
thinner. 

* Pottery cmUin lilin, Ino thirdi, ■lumiDk, frem one fitlh (o ono third, ini 
(ometlmea oao five huDdredtfa or one (wo thouauidtb of linH, Md Iron from (he 
■Dullest portton to Kor 20 per cent — Vauqudin, giuttd by Patku. 



DniitzcdoyGoOt^lc 



J, 



Handles, spouts, and other appeadagee are made separately, and 
are stuck on afterwards, with a thin paste of die clay, called aim. 

Vessels that are to have a peculiar form, oval, scalloped, nuted, 
be. are made in moulds, usually of calcined plaster of Paris, 
which, by its absorbing power, aids in drying the articles, and the 
moisture is expeUed from the moulds by heat, so that they are sooq 
rendered serviceable again. 

Btiming or Baking. — The vessels, after they are dried, either 
ID the air, or in stove rooms, are placed in earthen cases, called seg- 
gars, and these are so arranged that one covers another, in the oven 
or furnace, where thev are gradually heated for about 12 hours, by 
flues, communicating irom without, and the full heat is maintained 
bom 34 to 48 hours ; more or less, according to the size of Uie es- 
tablishment, and the nature of the ware.* T^e furnace being grad- 
ually cooled, the pieces are withdrawn, and are then in the stale 
otvucuit, as it is called : it will be a perfect pottery, only it is ab- 
siubent of fluids, and therefore cannot be used, except for pnnnoting 
evaporaticxi, when it is desired that the fluid should pass tluougb the 
pores and be exhaled from the outside. It adheres to the Umgue, 
because it absorbs its nxHsture. 

Porcelain contracts 50 much in baking, that some tablets which I 
have irom the Rc^al Manufactory at Sevre3,f in France, which were 
marited off into ten equal parts, are shrunk one division, comparing 
them with those that have not been baked. 

Magnesia very much diminishes the shrinkage of the porcelain, and, 
in the form of steatite, is now employed by theclnglish manufacturers. 
Great quantities of bones are consumed in the English potteries; 
it is done for economy, for the quality of the ware is injured, as to 
s and weight, although it is while and translucent. 



OmamentiTig. — ^Iq the state of biscuit, the figures are usuaUy put 
on ; in the finer kinds, by the pencil, and b the most beautiful por- 
celain, by the best artists, with exquisite taste and skill ; and oH^ a 
separate figure or scene is painted upon every piece of an extensive 
set : the colors are metallic oxides. The eround oxide, in fine pow- 
der, is intimately mixed with giun water, acid of tar, od of turpentine, 
or some other essential oil, and after the cobr is laid on, the fluid is 
entirely evaporated. The cokirs employed are the same as those 
mentioned under glass. 

* Trial pleeu tre withdrawn, from time to ttioe, to enable lbs minulaeturer to 
judge of tie itaie of the wore. 

t Tbb tia part of a very Uutnictlve colleellon, eontdi^i; t comptete mite of a]I 
the materialt med in the manufacture of French porcelain, and In all their itafM of 
uMpwalianaiid ftbrteition, from tlie decomposed grvolte, op to the perfect veMTi em- 
DracinK also a seriei of colon, applied upoD the porcelain, and acromnanled by ox. 

Cilory and deicrlptive eatalocuea. It iraa preacnlad to me by Mr. Alexander 
smart, the wipeiinlendant of the manufaetiHy, a j^antleman irell known tiir Us 
valuable reaearchea, and excellent irorks in mineralogy and geology. 
37 



D„tiidD,Googlc 



Very beautiful deaigDS are now fixed upon the commcHi ware by 
aJd of the c<^^>erplate printing press. The design, first punted, and 
iben et^aveil upon copper, is printed with a metallic cc^r, mix- 
ed with prepared linseed oil, upon tUver paper, which, with the figure 
upon it, IS immodiaieljr ap[^ed to die bi»:uit, and then tubbed mtfa 
a hard roll of fiaonel, to make it adhere, and after about an hour, the 
article is immersed in water, which softens the paper, so that it is easily 
removed, and leaves the colored figure ; the piece is next healed 
tnoderatelf in an oven, to dissipate the oS, and is thm prepared to 
receive the glaze. 

The porcelain is not always painted in the biscuit; sometiines it is 
painted on the glazing, and I believe this is generally done, on the 
most foeaatirul porcelajn ; it is dten necessary to heat the vitssels again, 
ia the enmi^r's oven, that the coloring matter may be melted, aod 
faicomrtrted with the glazing. 

€fuaitig.— To prevent the absorption of Quids, and to make the ves- 
sels more cleanly, they are covered with a vitreous coat, a thb glassy 
film, which, as long as it lasts, protects the ware below. In th« case 
of tbe common stone wore, it is produced by throwing into the hot 
furnace, common salt, which is raised in vapor, by the heat, when tbe 
soda vitrifies tbe outnde and forms a perfect covering, ^iach is also 
safe and cheap. 

1^ glazing, used on the common yellow ware, is composed of 40 
pounds of ground flints, and 100 of htharge,* or of 100 of lithu^e, 
and 80 of Cornish granite. 

For porcelain and the finer kinds of earthen ware, it is c<Hnposed of 
white lead, ground flint glass, ground silex, and common salt. 

The materials of the glaze are reduced to an impalpable powder, 
and suspended by ag^tion in watCT ; the vessels are dipped m tbem^ 
and d)ey retain enough to form a perfect covering when they are 
again exposed to ihe heat trf the furnace. This glazmg is dangerous ; 
on account of the poisonous nature of lead ; lava and pumice stone, 
have been substituted in France with good success ; and even 
ground flint glass, mixed with clay and water, has been found to an- 
swer ; indeed, no protection would be better than the common mate- 
rials of glass, was not die rado of its contraction and expandon ly 
heat, difierent from that of pouery, wWch would cause it to break. 
Metals and their oxides are sometimes mingled with the materials of 
dm glaze, to give it cc^or, in certain parts, as on the edges of 
plates, copper being used for green, and manganese for black. 

Porcelain is occasionally covered with gold or platinum in sub- 
stance. The gold is dissolved in nitro-muriabc acid, which is evap- 
orated, leaving the metal in a state of minute division ; it is next mix- 

' Tha French use galeu, Ihe native mlphuret of load, ttionce called potter'* 



D„tiidD,Googlc 



EABTHa. to I 

ed with honx, and gum niter, ttnd by means of a vt^iite ful, aj^ed 
to the article ; it is then baked, end afterwatds bumishetl. The 
lusUe ware is made hf apj^ying an oxide of gold,* with a volatite 
cmI, which is lai4 a^oa the vessels, colored by umber or red clay ; 
this appears through the gold, and ^vea the copper tiot. Ine 
steel colored ware is covered mth the precipitate by milriaU of 
uontonia, from the muriate of platinum, whicb is applied in a Buuilw 
way, but upcui a cream colored baaJa ; and in both cases, it '» 
introduced mto the enameller's oveo, where the beat dissipatei the 
volatUe priociples, and the metals being left in their dull state, are 
afterwaraa bunusbed. 

The ware is glazed before the gold imd platinum are applied. 
When prints are made to adhere to the oiscuit, in the maooer al- 
ready deacribed, as tbe glaze is applied afterwards, it is koporlaiit that 
it should be traasparent, that the colors may be seen tittough it. 

It should be mentioned that tbe gUsiiiE on the best porcelain, paN 
ticuhrly that of China, is composed eodrdfy of feld^Mr, finely pulver- 
ixed, aad suspended in an aqueous fluid, which is said to be in Cbioa, 
ft lye of 1^ aahes ; no lead, ot other metalHo matter, enters into its 
composition, and it requires a roty great heal to produce its fusion ; 
it is much turder than the glaza on most European porcelain. 

The Chinese ware ia made so firm that it is mera^ dried hekn 
dippmg it inU the glaze, and does not reqoire a previous beiung to 
lamg it to the state of bbcuit. 

In gmeral, the European porcelain, although superior to tbe OA- 
ental m wbitoieaa and beauty, and in its excRiiaite ornaments, is io- 
ferior in hardness, infiisibihty, wdght, capability of enduring sudden 
changes of temperature, and io the permanency of its glazing. Some 
of tbe Saxon porcelain is said to be equal to the Chinese. 

CrwibU* are made of the most infiuible cl^, and pipes and tiles 
are manufactured upon similar princijries with those that have bMo 
explained. -|- 
Sridu, of every varie^, are merely nide pott^. 
Fire Brickt ere made of vety refractory elay, csJled fire day, and 
are both more infusible and worse coDdoctors of heat than common 
bricks^ They are sometimes prepared so es to be soft, or capable 
ot being cut, m order that they may be adapted to difibrent purposes, 
and the fire, as th^ are used, hardens them efterwerds ; at odier 
times they are burned bard at first. Those manufactured at New 



• April 
ig gold 1 



M letter to the author rrom Mr. Actum, Id 1B09, menliDned, that fidniCM- 
u applied Id flib way ; if so, doubtlen Its < ~ ' ~ 
■tn^ed bj tba eomtautible mattor d the oil of iplka, w 

f 5m Parkea' Rsuya, Vol. II i riny't t^erative CbemlH, and BIg«l«fc'i Tecb- 
nology. 



OMzcdoyGoOgle 



293 Earths, 

Haren are made by asii^ a fire clay, brooght from Ambc^, and 
found near the pipe clay ; an equal measure of ralhcr coarse silice- 
ous sand is added, and tbey are baked in a potter's oven, widi 
less heat than b employed for stone ware. Such bricks ^dure tbe 
intense beat raised in tbe cylindrical fumaee stoves, in which tbe 
anthracite, and particularly the Lehigh coal 19 burned. On the side 
exposed (o the fire, they become ritrified, and the impurities of tbe 
coal, conasting of eartlu^ and oxide at iron, attach themselves to the 
bricks, in the form of a slag, and if the accumulated matter is not 
trecuiently detached, it eventually chokes the furnace. 

The eomtaon bricks are burned in hugej)iles, called, in tbis coun- 
try, '£*/n«, in England, CUmpa. They are constructed of the 
moulded and stm-dried bricks, laid up with interstices, for the flame 
and hot au-, and there are cavitiea left at tbe bott(»n, crossing tbe 
structure, in an arched form ; in these the dried wood is laid, and 
the fire being kmdled, is gradually increased, for the first tvrebe 
hours, after which it is kept at a uniform height for several days sod 
mghts, uqtil tbe brick* are sufficiently hardened. Some are exter- 
nally vitrified, or covered with a glaze, which b nothing but die 
meued materials of the bricks, and is not de^rable, as good bricks 
can be made without vitrificaticm. Some bricks are sM, and ab- 
sorbml of water, and will split with the frost : others are Grm, and 
Kill endure a great length of time. There is a great divernty in the 
clays of difierent places, as regards tbe goodness of the bricks made 
ironi tbem. Bricks, after being parnallv dried in the sun, are some- 
times pressed in iron machine^ which iorces out water and air, and 
makes them more firm and bandsome. 

Terra attta, at Ttm caitt, (burnt earth,) is used by tbe modern!^ 
as it was by the ancients, in making ornamental designs, " vase^ 
inuutiMiB, and architectural decorations." Tbe finer kinds of clay 
are employed, and they are wiUi great fccility moulded into any de- 
sired form. 

Reamur't Pofcelaia. — ■ITiia cnrioas production might have been 
mentioned under glass, of which it is only an alteration, efieeted by 
die action of ctwtinued heat to the point of softening, and foRbwed 
by slow cooling, when the glass knses its transparency, and under- 
goes a kind of crystallization. The change is most easily e^cted 
upon green bottle ^ass ; it is found to be owing to the k>ss of the 
alkali by the heat, and that tbe glass, thus changed will endure sud- 
den changes of temperature, as well as the best porcelain. It is 
usually prepared by filling a common green glass botde with while 
sand and gypsum ; it is buried and pressed down in this mixture, is 
a covered and luted crucible, and baked in a potter's kiln, during 
the usual dme of firing the ware, at the end of which period, it w31 
be found changed into a kind of porcelain. — Bigehw't Teei^ 



ALnainnm.* 



1. HlSTOKT. 

(a.) Oitcovered by Sir H. Davy, wbo obtained, by galraiuc pow 
er, a compound of iron and this metallic base, wiacb efiervesced in 
water, and produced alumina, and oxide of iron ; also, by passing 
potassium, in vaporf through alumina heated to whiteness, the potaas' 
um was coQTerted into potash, and metallic particles were c^tainadf 
which became white m the air, and efiervesced in water ; when the 
lempccnture was oo\y at a red beat, an alloy of the two metals ap- 
peared to be obtained, which eServesced violoitly in water, and tow 
fire spoDtaneously ir the air. . 

S. Nxw Process. 

{a.) Of late, Dr. ffohler hat obtained aUadtmm pere. f—j^lla 
student may unit this process until he has studied chhxioe.) Cbk>* 
ride of aluminium is fonned br passmg dry chlorine gas ttvough an 
ignited porcelain mbe, ecHitatning very dry ahanma, intiinMely Mend- 
ed widi charcoal, in ctmaequence of its having bMn mixed in tbt 
Stan of hydrate, oaA thm ignited in a covered crucible,' with char> 
coal, sugar, and ml ; the hydrate is made by addii^ an excess of 
carbonate of pota^ to a hot solution orf* alum. 

ab.) Carbonic oxide gas toat evolved, and after die «:Uorine gas 
passed for an hour and a half, the snUimed chloride of ahuntni- 
um sad collected in such quantity as to cbcdce the tiAe. 

(e.) TAe ddoride mu tn greeniMh yeBow tranilveeat teaUt,- reMm* 
bling tale, deliquescing into a clear Uipiid, and combining with water, 
with beat, and eren ebullition, if the quantity of water was anall^ 
and muriate of alumina was fonned. 

{d.) Potatsium decompoiei the ddoride (^ alamitUma, and etclwi- 
ihe vtetai. — The action is too violent for piss, which is destroyed 
by the heat disengaged. It succeeds in a platinum cniciUe, the 
cover being secured by wire, and the heat of a qxrit hunp applied } 
but the crucible becomes red faiit.:^ 

(e.) Jlte potimiam ihoidi be Jree from carbon, and the quanti^ 
not over the size of ten peas, and so fvoportioned, that iK»ie of the 
chloride may sublime, during the decompodtion, nor the resulting 
mass be alkaline. 



* AlBiniiium wimU imib ptefenbla, iHit I kdopt the ot1)M^r*phy tinaSf Intro. 

I Thefint hint wu gtven by Prof. Osnted, incoDMqiience of his hk*iiigobtttiiv 
•d what be believEd la ba almntnliim, by ■ctlng apoo chloride of iluniiu, by aa 
unaljgam of poUiduir 

h complete nieces*. 



D„tiidD,Googlc 



3$4 EAKTHS. 

(/.) The mass in the crucible is found to be mehed, and of a dark 
gny color, and when put into water after it is cold, the saline matter 
is dissolved, an ofiennve hydit^en gas is evolved, and metallic scales 
remain, which after being thoroughly washed in cold water, ''^ are pure 



3. pBOrXBTUS. 

fa.) A gray powder very ntniiar to that efplatmrnt^, in onaM me- 
tallic scales or spangleB, or ta sUghdy coherent spongr masses, bM¥- 
iog ui some places stm whits hetre, rendered more dtstiDct by jwv 
■ure on steed, or in an agate nuutar. 

(&.) itfine powder, a non-eondtuior of tiectrieHy, but becomes « 
ccndoctor after fitncMi.-t' 

ic.) FutUde at a higher heat than that w&iel meltt eatt iron. 
d.) J^ited in the air, it bwtu vividly, and (he product is alu- 
imnous eartfa, idiite and ccMuidentbly hard ; sprinkled in powder, in 
the flame of a candle, it givea bright acuuillatians, like iron in or^en 
gas. 

(eA ignited m mire ox^m gat, it burnt vitk great Aoot latd Iwft't 
•Qd ine resulting uuminais partially vitrified, y^tmiab, and hara u 
coniodom ; it even cots glass, mien bunnng in glass, it S{^>eared 
to reduce die ailicium, produdi^ a ssni-^iised brown spot. 

(/.) JVeor ^ition, it burnt tn aUarine gat, and chloride of ahi* 
nunnnn is formed. 

- ig.) JVot owidized nor tantiihed by oold voter } near viniSaaa, 
hydrogen gaa is feeUy erdved, and scarcely any oxidisemeot is (^ 
0«rved. 

(A.) Ab action mth itrong tviphuric or nitric add in the cold, 
but with heat, the former is decomposed, and sulphurous acid gas 
evolved ; it is dissolved in dilute muriatic and siuphmic acid, and 
faydrogHi gas extricated. 

Jt.) Dittoloed readily and entirely in dOute lahition <f ptOa^ 
wen tn ammonia, hydrogen gas being evolved, and much alu* 
mina held in solittiQii. j 

4. CoMBiNiNo WEIGHT. — Not sccuiately ascertained ; it has been 
already stated, that the number 10 has been adopted, and thai it 
corobinea with one proportiott of oxygon, 8, to form alumina, wbo» 
eijuinlent is of coune, 18. 



* The mIdUod ii Qsutral, uid contalni (ome alamiiii, Ibmud, u It i« Mid, in coor 
■equeBM att oombinttloo be(w«en chloride ofpoturinni, ud dilarida of ilumiuiam. 

f It !• Temarkable, u Dr. Wohler obwrred, that metallic Iron, in fine poioder, li 
a Don-eoftductor of electricity, as that Hth property of net)^ aeema to depeod m 
(heir fbnk, or, possibly, on utervenlng air. Perhapa if dttdnn were nailed, K 
might becoiae a conductor, aod thus be aarimilated to the metak. 

(Dr. Bramter'a JootimI. No. IT, p. IT& 



■d./Goot^lc 



5. PoLAmiTt. — EUetro-poiitiM, as appears from the orig^l ex- 
periiseat of Sir H. Davy, in whidi it waa attracted to an irtm wiro 
connected with the negUive pole of the galvanic Mries. 

R emar k , — ^Tbu ahimiDa so eztennvely difilised and so lanuliariy 
laxKvn, ahould contain a metal, distinct and remarkable in its pto- 
perties, and with the aid of potassium, so easily obtabed, b a very 
BUeTesling coofinnaikn of tbe views of die Uluuriom Davy,* and must 
give eelebi% to that of Dr. WoUer. 

SbouM the basis of the most important of the earths, namely, d- 
ticiiim, which Prof. Bentelius has, by the aid of the same agent, 
potasBhun, now placed fully witbio our reach, eventually prove, after 
nison, to be tnify metaffic, it would be an in t ere stii ^ ulditian to tbe 
series ; but in any event, the great fact that the earths are aU oxides, 
is snffiuently established. 

Sec. Vn. — ZiBCONjA. 

I. NaTHKAL HISTOBT AHD DISCOVERT. 

Never found pure m nature ; discovered first in 1769, by Klap- 
roth, in the jargon or zircon, a precious stone from Ceylon, in which 
be found 37.5 silica, .5 nickel and iron, and 68. of the new earth, 
which from its parent mineral, he called zirconia. In 1795, found 
by him in ^ hvadntht of Ceylon, and in 179€, discovered by Mor- 
veau, in those from the brook of ExpaiUy, in France ; Vauquelia 
confirmed tbe discovery by farther experiments-f 

3. Process. 

(a.) To the pulverized zircon, add three or four times its weight,]; 
of caustic potasii, and fuse it in a ^Iver crucible, throwiog in the mix- 
ture, spoonful by spoonful, and waiting for the fusion of each portion 
before another is added, and after all are fused, increase the heat and 
maintain it for an hour and a half. Wash the contenta of the cru- 
cible abundandy in boiling hot water, to remove the alkali. Now 
add muriatic acid to dissdve the zirconia, some silica is taken up by 
the acid, which is precipitated by heating the fluid, and removed by 
GltratioD. Lastly, add potassa ; the zirconia precipitates ; or it may 
be dirown down by carbonate of soda, and must then be washed 
sufficiendy with pure water. 



* WboM prmurtara death, the fHAoda or KteiKB and mtnUnd will lone dwloi*. 

I Dr. Tbommn, of Qlaigow, baa ill9c«v«red IS per ceoL orsirconit, in tha fUllJ- 
ntnite, ■ naw prlmnaUe mtaenl (peeiet found >t ChaHar, in 8>ybroali, Coos, uxl 
firal analyzad, named, and dMcribed by (ba late Prof. Bowcn, who found it la consial 
of alumina, 64.11, rilka, 42.66, iron, I.M, and urater .51. Dr. Tlionuon found a «im- 
itartXHUtitatlon.ezcapt that he dlscaTerod the zirconia aa above sCatad. — Jim. Jtur. 
VoLVIII, 196. 211; ret. XII, IS», and Pol. XVI, Wl. 

t Five or ax tlmu, Four. 11, 2la— nine Umei, Ura'a Dkt. SIS. 



OMzcdoyGoOgle 



390 EARTHS. 

(6.) Or, to 1 part powdered zircooia, add 3 of potassa, and heat it for 
one hour b a silver crucible ; add disoUed water, filter and wash well 
the insoluble part, which will be a compound of zirconia, silica, potash 
and oxide of iron. Dissolve in muriadc acid, and evaporate to dij- 
ness, to separate the silica. Redissolve the muriates of zirctMiia and 
iroB in water, and having washed the remaining silica mth w^eak mu- 
riatic add, to remove any adhering zirconia, ai£l it to the fluid. Fil- 
ter and precipitate the urconia and iroa by pure ammonia ; waab 
the precipitates well, and then btnl them m oxalic acid ; this dis- 
solves the iron and leaves the zirconia an insoluble oxalate, which is 
to be washed until no more iron can be detected in the washings. 

The oxalate of the earth, which, when dry, is of an opaline color,* 
is then to be decomposed h^ heat in a plaUnum crumble. -f- 

3. Pbofebtixs. 

(a.) A fine white powder, tasteless and inodorous, resembles aJu- 
mina, but somewhat harsh to the touch ; sp. gr. after being heated vi- 
<dendr on charcoal, 4.3. 

(6.) Infusible before the common blowpipe, but heated in a char- 
cou crucible protected by an earthen one, in a good forge 6re, for 
some hours, becoming a substance like porcelain, insoluble in acids, 
sufiering a partial fu»on, and acquiring a gray color. In this state, 
it win scratch glass — gives fire wiui steel, and has the specific gravi^ 
of 4.3. 

(c.) Perfectly fusible before the compound blowpipe of Dr. Hare, ' 
producing a white enamel. !{ 

(d.) Imoluhle in water, but u ahtorbetit of it, and when dried 
slowly after being precipitated form a solution, it has a yellow color ; 
retains about one third of its weight of water ; has a small degree of 
transparency, and resembles gum arabic. When beated red in a cru- 
mble of diver, it loses .37 of its weight. 

(e.) No action on combustibles, or oxygen, or nitrogen. 

if.) Insoluble in alkalies, but ditiolved tn alkalme carbonata. 

(g-.J Ifuolv&le in add^, until it fwa been acted upon again hy 
cauttic potash, and washed till the alkali is removed ; it is next dis- 
solved m muriatic acid, precipitated by ammonia and the washed hy- 
drate,^ ia then easily soluble in acids, forming salts, and tliose with 
the sulphuric, carbonic, and phosphoric acids, are insoluble in water- 
In general, the salts of zirconia are insoluble, and those that are solu- 
ble, have a sweetish astringent taste. 



* For B third procen. Me Tb6iu>rd, Vol. II, p. 296, tod Ann. de Chlm. at it PlV- 
T. XlII, P.24S. 

t Ann. de Chim. ct de Pb^B. T. XIV, p. 110. 

1 Am. Jour. Vol. 11, p. 292. 

j The liydrBte licalcd by a spirit lamp in i g[iut capsule, becouM ;«d bol. •■ 
if it wen <m fin- — Z^^nord. 



OMzcdoyGoOglc 



(A.) Zirconia differs from silka, in bebg much more soluble in 
adds, and Id beine insoluble in alkalies, but it is soluble in alkaUne 
carbonates ; in this last property it diSers from alumina and glucina. 

(t.) There it a great resemblance betvxen oxide of titanium and 
zirconia, in most of their properties ; hut tincture of galls precipi- 
tates oxide of ttanium reddish brown — zirconia in yellow flocks,* 

4. PoLABiiT.— From analogy, supposed w be eUctro-pontiw ; 
and to be attracted to the negative pole of the galvanic series. 

5. CoHBiKiNo wEtoHT, 48, conasting of zirconium, I proportion, 
40, and oxygen, 1 proportion, 8. — Thornton. It has been supposed 
from some experimeots of Berzelius, that it is 30 or 33. 

ZIBCONIUK. 
I. HlSTORT AND PROCESS. 

Sir H. Davy discovered, that wActi zirconia u igmled wUh po- 
tattiian, the latter is oxidized, and dark metallic particles are diffused 
dirougb the alkali. 

Berzeliiu has more recently procured thit bate, as he did sili- 
dum ; that is, by heating with a spirit lamp, in a tube of glass or iron, 
a mixture of poUissium and hydro-fluate of zirconia and potassa, care- 
fully dried ; at a temperature below ignition, the earth is reduced to 
the metaUic slate, and without any luminous appearance ; the mass is 
next washed with boiling water, and then digested for some tune in 
pure muriatic acid ; the residue is pure zirconium. f 

3. Properties. 

!a.^ Black at charcoal; it is a powder. 
b.S JVof oxidixed by boiling uxtter, or sulphuric or muriaUc acid, 
but dissolved by aqua regis, and hydro-fluoric acid, the latter evdv- 
ing hvdrogen. 

(c.) Zirconium burnt intentely m the open air, with a slight in- 
crease of heat, but far below lummousness, and produces zirconia. 

[d.) It combines with sulphur, forming a chesnut brown sulphuret, 
insoluble in muriatic acid, and alkalies ; but which burns briUiandy, 
regenerating the earth, and evolving sulphurous acid.t 

(e.) Doet not conduct electricity; it is capable of being pressed 
out into scales of a dark gray color, having somewhat of the metal- 
lic appearance, but it is not perfectly settled whether it ought to be 
called a metaL 

3. CoKRiHiNo WEIGHT — uot BCCurBtely determined. See urco- 
nia, 5. 



OMzcdoyGoOgle 



398 EABTtlfl. 

Sec. Vm.— Glucina. 

1. Name — ^Natural Histobt — Discotebt. 

From Y>Mus, sweet, because its salts have tliat taste. Ducovend 
in the beryl and emerald, in 1798, by Vauquelin, who at tbe requetf 
oi Hauy, analyzed the beryl to discover whether its chauiicai ia- 
gredieats were the same with those of the emerald, as irom pbyaical 
coD^ derations, he had coiuectured that they were. Xbe aiu/ysu 
proved the suspicions of Haiiy to be well founded. 

3. PaocESS. — (Th. I, 530.} Fuse pulverized emerald or her^t 
1 part, vrith potassa 3 parts ; dilute the maas with water, dissolve m 
muriatic acid, and evaporate to dryness, stirring the matter towards 
the end. Mix it with much water, and filter to separate tbe siUca, 
which is more than half. The muriates of glucina and alumina are 
in solution ; precipitate them by carbonate of pota^,* wash the pn- 
cipitate, and dissolve it in sulphuric acid. Add to tbe solutioB aul- 
phate oT potash ; evaporate and obtain crystals of alum. Wbeo oo 
more are formed by adding sulphate of potash, add cailiontfie of 
ammonia in excess, shake the mixture, and let it stand till tbe gluci- 
oa is dissolved by ^e carlxmate of animonia, and nothing but alunnaa 
is left, iben filter, and evaporate to dryness, wboi a white powder is 
obtained, which, after slight ignition in a crucible, is glucina, in dw 
jsoDOTtion of 16 per cent, of the stone. Euclase also contains 31.7S 
of tliia earth ; and by Mr. Soyben's analysis, the chrysoberyl of b<^ 
Hsddam and Bnnl, has as much as tbe emeraldif that is 15.90 
glucina for tbe chrysoberyl of Haddam, and 16, for that of BrasI; 
the other constituents were lor the latter, alununa 68.66, silica 5.99, 
(aide of titanium 3.66, oxide of iron 4.73, and water ; tar that of 
Haddam, 73.66 alumina, 4 siUca, 1 oxide of Itanium, 3.38 oxide of 
iron, and a little moisture. The existence of glucina in cbrysobeiyl 
bad been overlooked by the first analysts, until it was discovered by 
Mr. Seybert. 

S. PaOPCBTlEB. 

(a.) Inodorota, tatteleu, and intoltiile in water; but forms with 
it a paste of some teaaci^. Ii is a fine white powder, resembling 
ahimina, and like that adheres to the tongue. 

(b.) Do€a not contract in thejwe, nor afiect tbe test cxAota. 

(c.) &ecific ^vi^ 3. 

\d.) S^jmbleby the common hhw pipe, but perfectly fusible by 
tbuitfDr. Hare. 



. . „ „ LdlssalTe 

■cMnUted by nuHttic icid, tai prcdpiMie acEua by pure immonia ; then diMtIn 
dill io clxtookteofkinliiollia, and proceed lo iKe epd aa already directod. Ot.^*>^' 
Ini troai thetame poiat: add lo the precipitated earths pure potam, which frill dn- 
iaTTe Iha alumlaa, and a portioa of Ihe Klodna, but that which remains, ia Ihia eartb 



.yGcxigle 



101 prec 

Hi 



(e.) Combina mih poiatta and toda, hvi not with ammottia, al- 
though it is sohible in the carbonate of that, and of other alkalies, and 
ifl the mustic fixed alkalies. 

(/.) With all the acidtfonoM Malts, with a sweetish astringent taste ; 
they are decomposed by ihe alkalies, even by ammonia, which does 
t precipitate alumina, which glucina considerably resembles. 
) Resembles alumina m attractiDg coloring matter. 
) It is not precipitated by pnissiate of pota^. 
I B abtorii eamonic aetd, at the orMmary temperetmre tf (Ae 

4. CoMBmiFs wsiaBT.-— Slated by Dr. rntomson, and by Bet- 
zefius as 36. 

ft. PoiiUin. — From anak^ supposed to be electro pontive. 
GLCcniniif. 

1. Ttus base has not been distiQCtly obtuned, but the anaWy 
which would lead us to admit its existence, is strongly supported py 
the following fact 

3. Sb H. Davy ascertamed that by ignJtbg potassium with glu- 
cma, the metal b converted into potassa, thus proving the existence 
of oxygen in the earth ; dark colored pardcles, with a metallic aspect 
also appeared in the mass, and regained die earthy character by be- 
mg heated in the air, and by the action of water, bydn^eu gas bemg, 
in the tatter case, evolved. 

3. CoxBiNiNG WEIGHT. — Dr. Thomsou concludes diat the Dum- 
ber for the earth must be S6, and if it ccMiasts of 1 proportion of me- 
tallic base, and I of oxygen, the latter being 8, ue f<Hiner mil of 
course be 18.* 

4* PoLAHiTr. — Supposed from analc^ to be electro pontive. 
Skc. Dt. — Yttbia. 

I. Nahx — ^Kat. Histobt— -Discovzbt. 

Name, from Yttetby, a quarry in Sweden, where die minervl wag 
found, from which Yttria was first extracted. 

Discovered by Prof. Gsdolin, in 1794, during his analysis of diis 
mmeral, called after him, the Gadolinite, and confirmed by several 
emment chemists since. 

Yttria has been found, not only in the mineral mentioned abore,^ 
which yielded it m the proportion of 35 to 45 per cent., but also in 
another nuneral, ctmsisting of the metal tantalum, and yttria, cafled' 
yttrotantalite, containing about 30 per cent., and m die yttrocerite, 
which has about 6 or 9 per cent. I^ese minerals, as well as Ga- 
definite are found only in the quarry of Ytteriiy. 

3. Fbooebs. 



OMzcdoyGoOgle 



ia.) *Let the Gadolinite be repeetedly digested in muriatic acid, 
sdica remains. To the fluid, add liquid ammonia, boil the pre- 
cipitate in solutitm of potash, and filter. Dissolve the insoluble resi- 
due of the lest process in diluted sulphunc add, evaporate to dry- 
ness, ^ite, and redissolve it in vnOBi ; a precipitate falls down, which 
must be separated by the fiher. 

The filtered solution, when mingled with liquid amtncHiia, yields a 
precipitate which is Yttria.f 

(fr.) Fuse the Gadolinhe 1 part, witfi caustic potash 2, wash the 
mass with boiling water, and filter the liquor, which will be of a Gne 
green ; evaporate till the oxide of manganese, in the form of a black 
powder, ceases to fall ; then saturate the liquid with nitric acid. 
Digest the midissolved sediment in dilute nitric acid, which will dis- 
solve the earth with much heat, leaving the silica undissolved, and 
the iron highly oxidized. Mix the two liquors, evaporate to dryness 
and redissolve and filter, which will separate any silica or oxide of iroo 
that may have been lefl. A litde carbonate of potash will separate 
any lime, and hydro-sulphuret of potash will precipitate any mangan- 
ese ; but if too much be added, it will throw down the yttria too. 
Lasdy, ammonia wiU precipitate the yttria, which must be well wash- 
ed and dried. ^ 

3. PfiOPEaTIES. 

(a.) A Jine whiie powder, ii^uvhle altme, but with borax mehs 
into a glass. 

ib.\ Tatielea, tTOooth, and inodonu — no effect oa vegetable cok»s. 
c.) Sp. gr. 4.843, greater than thai of any earth, 
d.) Insoluble in water, but absorbs it, and k^es .31 of its waght 
when heated to redness. 

(e.) Soluble in alkaline carbonaitM, but not in pure alkalies, Hke 
alumina and gludna ; requires to dissolve it 5 or 6 times as much 
carbonate of ammonia as gliicina does. 

{/.) With acids forms sweet tasted salts, with some degree of 
austerity, and several of them are said to be colored, a fact not ob- 
served in any other metallic salts, but there can be Utile doubt that 
the color is owing to the adhering iron and manganese. 

(g.) Soludon of Yttria in muriatic acid, evolves chltHine after be- 
ii^ long heated. 

(A.) Oxalic acid, and oxalate of ammonia, precipitate yttria like 
muriate of alver. 

4. Poulbitt. — Supposed from analogy to be electro positive. 

5. Combining weight, 42. 



* Accnn. Mliwral, 

I ForUicproceHof 

lOdi Ed. Vol. I, p. 62B. 



For the proceH ol'VtuquellD, Me Ann. dg Cbia. p. 150, XXXVI, and Hewy. 



DK;,lz=..,C00g[e 



EARTHS. 301 

TTTRIUK. 

1. Not yet obtained isolated. 

3. Yttria converts potassiuiii into potassa, when aided by heat, thua 
proving the ensteiice of oxygen in tbe earth, which also exhibits ap- 
pearances of metallization, so that there can scarcely be a doubt that 
this earth consists of oxygen and tnfiamniable or metallic matter. 

3. CoHBiNiNO wziGHT. — Dt. Thomson assigns 42 as the repre- 
sentative number of yttria, and suppo^g that the earth is composed 
of 1 proportioD of oxygen, and 1 of metal, he states the latter at 
34, for 34 +8 ==42. 

• •*«««*, 

Since the account of the earths was m type,* Prof. Griscom has 
been so kind as to forward to me the foUowmg notice of a new earth, 
which, as it is so named by its discoverer, I insert here rather than 
under the metals. The learner will observe that it is a difierent 
thing from the substance formerly called Thorina. — Seenote,p.ilQl. 

ijucovery of a new earth, named TJionna, and itt metallic bate, 
named TJioriwn. — M. Dulong communicated to the Acadenw of 
Sciences at Paris, on the 26th of July last, in a letter from M. Ber- 
zelius, the discovery o( a new earth. " I have just discovered," 
says the Swedish Savant, " a new earth, which possesses almost all 
the properties of that which bore the name of Thorina, and which 
has been ascertained to be only a phosphate of Yttria. It is in con- 
sequence of this striking analogy, that I have retained the name of 
Tlrarina, for this new substance. This earth is white, and irreduo- 
ble by charcoal and potassium. After being strongly calcmed, it is 
attacked by none of the adds, except concentrated sulphuric, even 
after being treated with caustic alkalies. The sulphate of Thorina 
is very sduble in cold water, and almost insoluble in boiling water, 
30 that it may be freed fr^im many other salts, by washing the mix- 
ture with boiUng water. Thorina dissolves eaaly in carbonate of 
anuDODia. An devadon of temperature occasions a precifMtation of 
a part of the earth ; but on cooUng, the precipitate disappears. All 
tbe salts of Thorina have a very pure astringent taste, very similar 
to that of tannin. The chloride of Thorium, treated wHh potassium, 
is decomposed with a triple deflagration. There results a gray 
metallic powder, which does not decompose water, but which, raised 
above a red heat, bums with a splendor almost equal to that of phos- 
phorus in oxygen gas. NeverUieless, Thorium is feebly attacked 
by nitric and sulphuric acids. The hydrochlorio, on the contraty, 
dissolves it with a brisk efiervescence. Thorina, or die oxide of 
Thorium, contains 11.8 oxygen. Its specific gravity is 9.4. Tho- 
rina exists in a new mineral which has been found in very small 
quantities at Brevig, in Norway. — BtA. Univ. JuiUet, 1829. 



OMzcdoyGoOgle 



INFUHMANJS. 



•nnx iim.uauBLB and acdhtuble mdibs, (on« i 

TflEia COMBUtATumt WITH THE rBECKDIMa 1 



&c. L — Htdboou. 

(a.) This mfltminaUe bod^ has been already described mder 
the bead of vnaer, and b here menooned again cxdy for tbe sake of 

(6^ WiA oKjceo, it larms no acid, bm it fwnis one k 
aa wis be rimrn m iu fbtee. 

Sec. !!.< — StTLPBCft. 

!• H laTOKTi— — Klxnn dkmd the remoteat airtiqtn^. 

fl. SotTBGEB. 

(a.) FoIcnaM, ortaw, dormant ar ea^inet ; subEmed bv d>e S(^ 
t ax r awMD beat, ooUecto in cratert and acd&tmaa, as neu- Naples, in 
Oaudaloape, lie. 

(i.) (Ambiiud with aicMb, fbrtning omnenus species of oatira 
ittlpfaurets, as of inn, txfppee, lead, silver, &c. sufaiimed from them 
bf atttfidal beat, bm is Dot in tlus maimer obtamed pure ; it is coo' 
laminated widi tbe metals, widi wbich it was combined. 

(cj in SN^pAureoat mimend (Mtfer*~anpaniiig a diigustiog odor, 
and toe propertr of blackening white metab and tbdr sohtioiis; be- 
b^ mmended tnr hjdrogen, it is depomed as tbat gas is exhaled, 
ai^ ia mmd in me channds, tfaiougb wfaicb ^ waten pass.* 

(d.) in MMMiti and plmttt^oaad more or less in all ammal bo- 
dies, as is proved bjr the production of snhrfiuretted faydrogm, dar- 
ing their decompoaibon. Among plants, m the mmices c»- docks, 
in tbe cruciform plants, as scurry grass and cresses. 

Sulptmr WHS sublimed by Deyeux, bom roots of horw radi^ and 
ofdocVt 

(e.) £t roeki and Homm, along with gypsum and sulphate of stron- 
tifl, and even with the primitive rocks in veins, and scnnetimes in in* 
dunied mart and compact limeabme ; arising peibaps from the de- 
compositini of sulphurats. 

*AtNl*K*r>, hoazaifnimaMbtdneM'AeDorft tUs ot Ota peat Battt SbM 
m.~Oimet*tnatioii», Oct. I8ZT. 
t Exiali la efg*, ia privlei, ia pita ia wUch flu hw been iteeped, he. 



OMzcdoyGoOgle 



INFLAMMABIJM. 303 

(/.) Lt stdphaie add, forming a cooMituent of the natural sul- 
phates of lime, baryta, strontia, soda, Sec. and in the free sulphuric 
•nd sulphurous acidi. 

3. Propebties. 

fa.) SjD.^. 1.99. 

(6.) liUctric by friction ; color lemoo yellow, but precipiuted sul* 
phur a at first white, and it becomes white if water be dropped on it 
while in fuaon, and also if sublimed with watery vapor ; the whiteness 
it supposed to be owing to a combinatioD with water ;* electrici^, 
negative or reaiuous ; a non-conductor of heat. Hence, a roU of it, 
grasped in the hand, crackles in consequence of its brittleneas, and 
of its unequal expan^on by beat. 

(c.) Emits a peculiar odor uiA«n nMtd or Iteattd. — ^Brittle and 
fracture brilliant ; it has a connderable refractiTe power. 

(d.) Evaporaiet at 170°, with a disagreeable smell ; fuses at ISV 
or 190° ; fluid at 330°, most perfectly fluid between t30P qnd a60<>, 
when it is of an amber color. 

(e.) It be^ns to thicken at 330° ; at 350°, stifiens and acquires 
a de^r color ;'|' is very tenacious between 438° and 482°, hut 
frtxn that to its boiling point, it grows fluid again, and on cocriin^, also, 
it recovers its fluidity ; diis may be r^ieated by sudden transitions of 
temperature in close glass vessels ; otherwise the sulphur i* voJati- 
lized.l 

Evaporatei at 390° ; it can be distilled from a ^aas retut into a i»i 
eeiver. 

(/.) SubUmei at 600°. — ^Tbe sulphur being thrown on an ipiiied 
iron, and covered suddenly with a beU glass, the latter is inBtaody lined 
with die sublimate called flowers of sulphur ; melted, skimmed, de- 
canted, and cast m moulds, this forms the best roll sulphur.^ 

* It ii Bald alio to icqulrB * pilar color from adultentlin) wltb rorin, flour, lt«. 
t Id thli (tato, or when bwOed to 4il8«, It ii poured into hot water, and is tued lo 

Tr medala, they being Imprwaed upon it nhllc it i* warm. 
TUnird, 1, 107, quoted bv HeniV, Voi. I, p. 860. 

S Roagb mlphur l« purified by meltliig It in cut iron bodies or retorti, covand 
«rla mtUmd wve beadi; about all cwt at oac«, and th« diitllled mlplur ta 
dnwnofl' iBIo water, at the lower of three bolei in the rtceiver; «ne I»eiu br 
die admiatan of the retort, and one far theeMape of the vapon; the refined •alphur 
ii eait In monida made of beech wood. In aubliming sulphur, the furBace ii below, 
and Iba auiphnr, melled in iiVD ptm, riiM into • room placed afane, wtwrp h ii CMt- 
deneed lo flowen or aubHniale. 

Itbniblimed alio from tliick inn piiti,afllie capacity of 10 or IScwL by a lateral 
coDiDUDiMlSoo bwn lb dome into a ehimlier, which, ir Intended for roll luiphur, may 
b« not more Ihio one fifth the rize that would be requlilte, if flowen of nilphnr were 
(o be made. — Oray't Op. CTlcm. 

If the distillation Is rapid u>d Ineeenant, it will condense in the liquid lotia, and 
will be made into roll sulphur ; If alon uul with suspension it night. It will be In IIib 
iorm of flowers. Formerly, crude sulphur wis merely melted, and when the impurl- 
tiei had lubaided. It wis ladlid out and east in moulds; the sulphur tlius obtained 
was impure, and much was loat in the sediment; the best roll sulphur, as well as 
flowei?, has been distilled or sublimed. 



OMzcdoyGoOglc 



304 INFLUIHABLES. 

(g.) I» the mit, to form the fiowert, it it niiimed in room* Utud 

im^ ikeetUad. 

(A.) Extttmned by the teti fiaidt, to tuceriain whether it is add; 
a^tate it with ialWon of cabbage or Utmus. 

ft.) Cryttallization — natural b volcanos— often beautUiil modi- 
fiea octabedra ; by art — sulphur melted in a broad deep vessel, sev^ 
erel pounds at once, (a crucible or earthen pot will answ^er,) when 
its surface corneals, break it and pour out the liquid interior. 

(/'.) Tlu camty willhe found lined loithpriimatic or needle form 
eryitaU, of which the basis is an oblique rhombic prism. 

(A.) f¥ith ttmler — no action ; if the sulphur be pure, it comes off 
tasteless ; but precipitaied sulphur is abydrale, and is white ; it was 
formerly called lac ttdphurii. 

(l.) ffith liquid alcohol'— no action ; in Taper tbey unite, a vial 
o( alcohol being suspended in an alembic b which sulpfaur is sublim- 
ed, the spirit rises too, and a union results , water precipitates the 
sulphur. 

(m.) BcMting essenbal oil of turpentine dissolves sulphair eotireiyi 
but not the usual impurities ; hence, used to detect its adulteraticMis ; 
when properly purified, it has a fine sparkling tnilliant yellow colW'* 

4. An element in relation to our knowledge, 

(a. ) Sir H. Davy evolved nUpkuretted hydrogen from it, by gal' 
mmiem—hut is not certain that the gas did not c<Hne froin decom- 
posed water, bdged in the interstices.-j- 

(b.) Potanittn ew^vee nlpharttted hydrogen, with intense beat 
and hght. 

7. Uses. 

{a.\ An important artide in the materia medtca, both intemaUy, 
as a laxative, and externally, as a remedy against cutaneous di»- 
eases. 

(b.\ Tbe basis of the manufacture of sulphuric acid. 

(C.J Used widi iron filings as a cement, and for matches. 

id.) In its viscid form for copying medals, &c. 

[e.j The chief use is in the fabrication of gunpowder, of which it 
usually forms 15 per cent. For these and other purposes it is large- 
ly imported into this country from Italy, whose vtJcanic regions 
idwund with sulphur, particularly in the Solfateira near Naples, and 
it comes, in perhaps larger quantities, from Sicily than from Naples. 



•Alkio'tDlct.Vol.II,p.36S. 

t Berzelius found that when metalicoiilbiiw wiflin)lphur,udry as poailble, liUl« 
or no sulphuretted hydrogen ii exhaled. 



OMzcdoyGoOgle 



INFLAMMABLES. 306 

(A.J To divide a bar of iron j when at ignitloo, or better at a white 
heat, if rubbed with a roll of sulphur, the iron melts and falls in drops 
of liquid sulphuret. 

" If a gun barrel be heated red hot at the hut-end, and a piece of 
sulphur be thrown into it, on closing the muzzle with a cork, or blow- 
ing into it, a jet of ignited sulphurous vapor will proceed from the 
touch hole. Exposed to this, a hunch of iron wire will bum as if 
ignited in oxygen gas, and will fall down in the form of fused gbb- 
mes, in the state of proto-snlphuret. Hydrate of potash, exposed to 
the jet, fuses into a sulphuret of a fine red color." — Dr. Hare, 




5. PoiJUUTT — Eledro positive ; it goes to the negative pole in 
the galvanic circuit. 

6. CoMBiNino WEIGHT, 16, hydrogen being 1. 

8. Phaskacy. — No peculiar preparation is necessary to tit the 
best roll and flowers of sulphur for medical use. Whether it is acid 
may he learned from its taste, and from its efibcts on the test colors j 
if it turns the blue vegetable color red, it must he washed ahund- 
antly with hot water, and the addition of a little alkali will aid in re- 
moving the acid. 

ACIDS. 

Preliminary Remarks. 

One of these bodies, nnegar, seems to have been always known to 
mankind. In the progress of time ; accident, art and science have 
either developed or formed many more. There can be no doubt, 
that the at^ds are all compound bodies, and that the only one which 
remains undecomposed, the fluoric, has an inflammable base, like the 
rest ; for, with this exception, all of the himdred or more that are 



.yGcxiglc 



306 INFLAMMABLES. 

known to chemistry, have inflammable or metallic matter, as their 
bads, and with only a few exceptions, it has been proved to be com- 
bbed with oxygen, whlcb, instead of being regarded as the exclusive 
acidifying pnnciple, may siill be viewed as sustuning tliis agency is 
nearly aU cases. 

Tbir^ years ago, there were three acids whose composition was 
unknown, namely, the muriatic, the boracic, and the fluoric. Although 
the latter is still un decomposed, the boracic acid has followed the 
general analog, having yielded a new combusuble body, boron, united 
tt) oxj^en. The munatic acid is now believed to be composed of hy- 
drogen and chlorine. Sulphuretted hydrogen has most ol the proper- 
tes of an acid, hut contains only sulphur and hydrogen ; the hydriodic 
acidconsistsofiodineandhydrogen, and tlieprussic acid of carbon and 
nitrogen, united to form a compound base, which is however not acid, 
until it unites with hydrogen. Thus, there are four* acids in which 
hydrogen appears to be essential to the acidity, and oxygen b not 
present ; whde the bases of three of these acids, namely, sulphur, io- 
dine, and chlorine, form other acids, by uniting with oxygen ; and even 
the compound basis of the pnissic acid, con»st3 of elements which, 
individually, form acids with oxygen. 

Some chemists are now inclinmg to the opinion, that no one princi- 
ple can be regarded as being endowed with die peculiar preiiB^Qve of 
oeii^ an acidifier, hut that acidi^ may, and often does ardsenran a 
balanced or conjoined efiect of several principles, f Oxygen exists, 
as we have seen, in all the alkalies, except ammonia, and in all the 
earths and metallic oxides, so that we cannot attribute to it the ex- 
clusive property of producing either acidity or alkalinity, although it 
is in most instances concerned in both ; still, that body without which 
another would not be add, must be considered as its acidifier. 

Most of the acids that have been discovered, are of very little im> 
portance ; but several of the principal acids are eminently valuable, 
and their history, being equ^y instructive and interesting, will be 
developed with sufficient detail, in connexion with that of the in- 
flammable bodies that form their bases. In giving tlie history of the 
Erincipal acids, I shall therefore pursue the synthetical course, as 
ebg the most convenient and inteUigible, although the analytical was, 
for the same reasons, adopted in the account of the alkalies and 
earths; or, in other words, the bases of the most important acids will 
be presented first, whereas those of the fixed alkalies and eartlis 
were presented last. 

* BeddM olhers of a moat doubtrul chiracler, u thai compoged ot hydrogen 'od 
tellurium. 

I For *D Ingcnioua diicuaaion of Ms view, see Muimy'ei Eleiuenl!, 6th Ed. Vol. 
11, Art. Acidt Mr. Murray is Inclined to Ihink ihnl even the water, uaualty re- 
garded ai combined with acids and ■Ikilie". aria r.(llier by iln elements, than In the 
cbaraeter of water,! fact ivhlcb it may be iliflicull eilber topiDveor dbprove. 



OMzcdoyGoOglc 



INFLAMMABLES. 307 

GENERAL PBOPERTISS OP ACIDS. — THEIR NOMeHCLATITItZ. 

1. Most of ihem sour. 

2. Soluble in water ; most of them largely — some very sparingly. 

3. Redden most of the vegetable blues — restore the colors that 
have been changed by alkalies or alkaline earths. 

4. Combine with dkalies, earths, and other metallic oxides, and 
form salts. 

5. The stronger acids corro^ve. 

6. They consist generally, of an inflammable base, combined with 
oxygen ; in a few cases hydrogen takes its place.* 

7. . Exist solid, fluid and gaseous, in dififerent cases. 

NOHENCLATURS OF THS ACIDS. 

[a.) In the new or French nomenclature, acids are named from 
the inflammable bases. 

(b.) The termmation ic denotes the lugher combmatioD with oxy- 
gen ; otts, a lower, and the proportions in both are definite. 

(c.) Where there is only (Hie proportion of oxygen ^e terminati<»i 
is in ic. 

(d.) Where the base is complex, as in the animal and veget^le 
acids, the termination tc means nothing, and the acid is usually 
named'from the substance which aSbrds it ; as tartaiic acid, from 
tartar, Sic. 

(e.) The names of the hydracids, as they are called, terminale in 
tc, as hydrochloric, hydriodic. Sec. 

SULPHtTRIC ACID. 

1. Nake. — Derived from «u2pAur, the inflammable, base, which 
affi>rds also other acids. Oil of Vitriol is the name of die shops. f 

2. HisTORT. — Discovered by Basil Val^atiDe, at the dote of the 
ISth century. 

3. Early Process. — By dittiUine lulphateX of iron, (copperas,) 
whose water of crystallization, amounung to about one hall its weight, 
bad been previously dissipated by a moderate heat. This process 
is still followed in Saxony ; 600 lbs. of copperas gave Bernhardt 
but 64 of the acid, and when no water was put into the receiver, &2 
pounds of a dry concrete acid were obtained, formerly called glacial 
oil of vitriol. Glauber says that sulphate of zinc afibrds a purer and 
better acid, and with less heat.^ 



lilt wboll; of comlmMlbla clamanti. 
imbuitioD ind aoiDQ would rcfar tba 
osiodic and the chlariodle addj to ue Utter cIbu. 

t Beeaura it wu di*dUed from green vitriol, md ha* an oily coniEateDm ; II wu 
called spirit of vitriol, when It wai len concentrated. 
t Illstbe sulphate of the protoilde, whlch.punes tolhecondlllonof peraxUe. 
\ Pirkoi' EBH)r«, Vol. I. p. 46S. 



OMzcdoyGoOgle 



SOB IMn.4MMABI.E9. 

4. Mwrew pBoccat.* 

(«.) Carried am iMdtam6en,Iiaed lJimigkaKX,witJk sJkeet Umi; 
iHual size, 20 feet long, and 12 wide— or 4C lo 60 by 16 or 18; 
in ooe case, in Eo^and, 120 b; 40, and 30 Ya^^—coaxem* 960O0 
cubic feet. 

{b.) SvljAur, 7, 8 or 9 parU, coarwda trwed, amd 1 p^t af 
tommo» nitre, are mxed. — One poond of toe mixture Sar every 300 
cubic feet of air, it pbced m sefiente portions upon irtxi or JeadeD 
plates, supnoned by suuds oS lead. T^ suli^iiir is lifted by ■ brt 
iron and the door closed.')' The eombustiaa coutiDues 30 or 40 
miouies, and io three hours the acid gas is absorbed hj tbe water on 
the floor of the room, idncb is usually about six incbes de^ ; or 
sometime* the acid nt»rs are carried by thecurreUof air tfaainp- 
pOfts the cooibuitioa, nao anoiber leaden room, where they aie am- 
densed bv waler.t 

{e.) The room it the* ventitated, and tbe [Xoceas repealed etaj 
(our hours, day and night, until the water at the bottom is anffirifrt^ 
■dd. 

idA Then it u dram off by a tytAon, into a leaden reservoir. 

{e.j It w pumped JrOM t/uM into leadtn bmUn, and there coaoea- 
traieajl by Iwat, until it is of the sp. gr. 1.350 to 1.450, or 1.560. 

(/.) u it jmithed in glait retortt, daced in sand baths, and the 
retorts are now generally furnished wkn platinum wire to {vevent tbe 
concussion in boiling ; water, and nitrous and sul{rfnirous leid gas be- 
ing expelled, it Uien has the speci6c gravity 1.850, or, as Dr. Ure 
says, 1.842, if pure. For ecooomy, the CMkcentraiion of sulplKinc 
acid is now ofien performed in platmum IxnlerB, jdaced whbm iron 
mes of the same size and form. 

The converuon of sulphur into an acid,^ is easily proved by bunung 
it in a pendent metal spocm, introducea into a bottle of oxygen or 
common air, on tbe bottom of which is some littous iofuskn.^ 

5. PftOFCnTIES. 

(a.) Thick, mly looJdag fiuid ; pours slowly from vessel to ves- 
sel; corroave, and, with or without heat, destroys all animal and 
v^etable bodies ; tbe first sensation when it is Tm>bed on tbe sldni 
la (hot of lubrici^, hut immediately after, there is extreme burning- 

* Bafun b; Dr. Ward, Id Eaglaiul, before 1746, by caoibmrtlao la g\tm belk v 

C'lu; Id 1746 Dr. Boebuck Introduced the U*dBn chimbere it BirminfEfaun. — 
ke«' EMty; Vol. I, p. 476. 
t A red hot einooo ball is •ometimea rolled in throagfa a tntugli lined with inn. 
t The (heorj of this procria caoDOt be full; elucidated untli we have become *c- 
qualated with tbe nitric compouDdi, when It will be reaumed. It may be Mated, 
nowerer, that fuiphuroui add ii tbrmed rrom tbe lulphur, and nitric oijde gai from 
the nitre ; thle obulni oxyceit from the air, become* Dttroas acid vapor, then oij- 
Kenisae the •ulpburoof eeld, tod tuma it Into aulpharic acid. 

!The aulpburoui. 
CoooentratlDD ii when a volatile logiwdlent ii driven off, and a nore fixed one ia 
•vred, — DUtlllation when the volatile bgredicnt li laved. 



J cy Google 



INFLAHHABLES. 309 

(b.) When pure ; eolortett, limpid, inodorous ; intensely mnu', eren 
wben lareely diluted with water. 

(c.) ^. gr. u already stated, 1.850,—or (Ure,) 1.84S ; ae- 
cordiDg m Dr. Thomson, 1.847 ; if heavier, it may contain sulphate 
of lead, or sulphate of potash, or both ; %ijpet cent, of sulphate of 
pota^ gives it the sp. gr. of 1 .860, and Dr. Ure sutes* that the best 
acid of cfHiimerce comaina fi-om ^ to | of 1 part in lOO, of for^gfl 
matter, which is sulphate of lead, m the propcffdon 4, to sulphate of 
potash l.f 

(d.) lU parity it decided by taiurating it by an aikali. — ^Div car- 
bonate of soda, 100 grains, neutralizes 92 grains of pure liquid aot- 
phuric acid, and 100 of the acid require 108, or 108. ( of the Car- 
bonate . t— Henry . 

(c.) Produceiheatiiehenimnghd with water ia every proportion f 
4 acid +3 water=300° Fahr. ; or better, S§ acid to 1 wator, ct 
by measure, 1§, or 1^ acid to 1 water .^ 

Place a thin glass tumbler in a dish— ^xiur in the watei^-provide 
a thin glass tube, 8 or 10 inches long, and £11 it two thirds with 
colored water, add the acid in a slow stream, stirring with the glass 
tube, and soon after, the water in the tube will bml, and another 
tube, filled with alcohol, will also be made to boil. 

lixplanaiion. — ^Increase of speciSo gravi^, and dinunutimi of c»- 
pacity for heat. 

Two by measure, of acid +1 of water, starting from 60°«300°, 
and the concentration ^^'j. 

(/.) m** ice— Ice 1+ acid 4=312°. 

ice 4-4' acid 1 produce intense cold. 

In both instances, the adSni^ of the acid for the water producer 
fusion, as the two cannot unite while the water is solid. The ezceo 
of acid then goes, in the first case, to produce heat with the water form- 
ed ; in the second case, there being no more acid than is wanted fcs- 
the fusion, cold is produced, upon the general principle that fluidity 
requires heat, and that the absorption of heat produces cold. 

\g.) Ahiorptitm of water from the air. — Rapid, especially if bx- 
posed with a large sur&ce ; in one day 3 parts became 4, and 1 ox. 
m twelve, months gained 6^ ; a drachm gained in five successive days, 
68, 58, 39, 23, and 18 grains, and in five days more only, S, 4, 3^ 4 ; 
in one case, in fifty sis days a drachm became 6^ drachms. 

• Diet. 2d Ed. p. 81. 

t The tcid or commerce olten contalm 8 or 4 per cent, of nlt«, ud aouetlnle* 
more irlltng ftom (be uae ol nitre, lo remove the broim coEor ; ev^mralloD In t, plm< 
tiaum dlahgtreia prompt result, and if there are more than t> graint Id SM, th« acM 



ttrboaatc oT aoda, al the j stud In our modarD worki. 1 W acid ahould DBUtralJH 

nearly llO of earbonati "" "" ' 

C. 8.) — CommwUaied. 



nearly llO of urbonate soda. (49 Ilq. aut. acid:S4 earb. aadaV:100S. A.: llOJl 
", 8.) — CommwUaied. 
i Be?eaty thrM >dd to twenty iCTen water, or vary nearly > acid to 1 wtler.— ITrw. 



OMzcdoyGoOgle 



310 INFLAMHABLIS. 

(A.) Duadoration from the air, fye. — All common combustibles, 
even the floating duat in a room, will discolor this acid ; a drop of 
oil of turpeatine does it instantly ; it is decomposed by the acid, and 
carbon developed. 

(i.) The pure add it not rendered turbid by dUution utith water. — ' 
The impurities are chiefly sulphate of potash, and sulphate of lead; 
the latter being very insoluble, is precipitated, renders the acid millgr, 
and in time subsides ; hence dilution is a means, to a certain extent, 
of purifying the acid.* 

(j.) The add it purified by dittiUation. — Dr. Ure's method is 
good, and avoids the danger which was encountered in the old way. 

Arrangement. — ^A retort of from 2 to 4 quarts capacity ; acid 1 
pint, adopter 3 or 4 feet long, terminating in a lai^e receiver ; ap^Ij 
a charcoal fire to the naked retort, wluch should contain along wiui 
the acid, a few pieces of broken glass, or some platinum wire,f or 
platinum foil, which will prevent the heavy recoil upoo the glass, 
produced by the sudden condensation of vapor, and- by the giest 
weight of the fluid. 

(«.) BoUing point. — Acid of sp. gr. 1.850 contuning 81 percent, 
real acid, boils at 620°, and at a lower temperature, in proporticxi as 
it is mingled with more water; that of sp. gr. 1.849, boils at 605°, 
and contains 80 per cent real acid ; thu of sp. gr. 1.836 coataining 
real acid 75 per cent, boils at 530°, &u:. It is rendered stronger 
by heating, until the acid Itself rises in vapor, and if mingled inth 
combustible matter, this is burned off by healing it. 

(/.) The freezing point. — ^This depends on the diludon of the 
acid. If of sp. gr. 1780,t it congeals at 45° ; viz. with 13 degrees 
less than causes water to freeze ; it freezes at 32°, if any where be- 
tween 1.786, and 1.775; if 1.843, or like that of conunerce, it 
freezes at— 15° ; and if half water, at— 36°. 

When once frozen, it does not easily melt j it sometimes forma 
regular mismatic ciystals.^ 

(m.) Effectt cm the tettfluidt,lhe same that were mentioned under 
the general properties of acids ; infiision of litmus is very s^isible, 
and that of purple cabbage sufficiently so ; alkanet tincture, previ- 
jwsly blued by a little ammonia, is instandy turned red again by a 
drop of the diluted acid. 

* Dr. Ure, by BTaporaling 100 parttDTaulphuric kcU, In ■ platinum dith, obUiOMl 
three quirton of ■ part of aoM matter, of which 2 (4 ! p. 309, e.) WM (ulphtte ^ 
potash, and I sulphate of lead. — Jour. Science, Vol. IV, p. IIS. 

Far ■ table of the boiling point of Kcid of dlOerent deiuillet, see Henry, Tol. I, 
p. S86, and Eug. Jour. Science, Vol. IV, p. 137. 

t I have found It to succeed well without Ihii preciutlon, which, howeraTgl' 
udght be advlsablB to take. 

f Eanly brouEht to this specific gmvily by mlnEline 6 1-8 parts of the letd of 
commerce wllh I 1-8 of water. — Thomson's First ntnclplefl. Vol. I, p. 214. 

I See Am. Jour. Vol. Vt, p. 186. 



Dk;,Iz=. ./Google 



inflammables. 31 1 

6. Decomposition. 

(a.) Driven in vapor through a red 'hot platinum lube, or a small 
tube of glass or porceltun, this acid is decomposed, and afibrda sul- 
phurous acid gas, two volumes, and oxygen gas one volume. 

(h.) Its decomposidon is best effected upon one of its salts, as will 
be mentiooed under sulphate of baryta, from which we can obtain the 
sulphur. 

(c.) Healed with charcoal powder, it is decomposed, and various 
gases are evolved, as will be mentioned farther on. 

(d.) When it chars any animal or vegetable substance, it sufiers 
decomposition. 

(e.) Decomposed by galvamsm — sulphur appears at the negative, 
ana oxygen at the positive pole, platinum wires being used. 

(/) ^y heiug passed through an ignited porcelain tube along with 
hydrogen, which unites with its oxygen and precipitates the sulphur, 
aind perhaps evolves sulphurous acid gas. 

7. Pbopoktion of its constituents and combining weight. 
(a.) CerUe*imal ratio. — ^Writersvary between 43.28 sulphur, and 

56.72 oxygen, and 40 sulphur and 60 oxygen. Dr. WoUaston ad- 
mits the latter numbers, and Berzelius those that approximate (o 
them ; 40 and 60 are probably correct. — Murray. 

(&.) Equivaieat ntun£erf . — The proportions of 40 and 60, corres- 
pond with 16 of sulphur, 1 propordon, and 24 of oxygen, 3 propor- 
tions, making 40 for the representative number of the dry acid, and 
liquid sulphuric acid = 1 real acid, 40, and 1 of water 9=49. 

It b supposed that by volume, the sulphur would be represented 
by 100, and the oxygen gas by 150, for oxygen gas is considered as 
combining in the proportion of half a volume which would be 50, if 
the 1 proportioD of sulphur is called 100, and there are 3 of oxygen, 
which would of course be 150. 

8. Anhtdbods acid. 

(a.) The dark fiuning acid, already mentioned as being obtained 
by distilling green vitriol, has a sp. gr. of 1.896 or 1.90, and boils 
from 102° to 122° Fahr. 

(i.) Heated in a glass retort to which a receiver is attached, sur- 
rounded by snow and salt, half of the acid passes over in a sute re^ 
Bembling asbestos, and is regarded as sulphuric acid without water, 
or the anhydrous acid, and the acid remaining in the retort is like 
the common oil of ^triol, composed of acid one proportion, and water 
one. 

(c.) It is the pure acid without water. 

\d,) It smokes violently when exposed to the air, and is dissipated 
too speedily to admit of being weighed. Tt is less corrosive thui 
cotnmon sulphuric acid. It crystallizes in tough silky filaments like 



OMzcdoyGoOglc 



31S INFLAMUABLES. 

aabestOB, or tn flat transparent rhomboids, of which tbs large ui^es 

are but little above 90°. 

Thrown into water, it acts like red hot iron. 

It liquifies at 66°, is mora fluid than the common acid^ and bas ■ 
specific gravity of 1.97. 

9. Importance and uses of st^LPHuaic. acid. 

(a.) Lai^ely used in chemistry, beiag the most common agent 'a 
decompositions, where other acids are to he separated from their com- 
iHDatioas. 

(6.) For generating hydrogeo, with the aid of zinc or iron, and 
water, for filling balloons. 

{cA For the manufacture of soda water, to evolve the gas from 
marble powder. 

(d.) Tor manufacturing mtnc, muriatic, citric and tartaric acid^. 

(e.) In dyeing, bleaching, cleaning metals from oxide, and in pre- 
panng chlorine for disinfection. 

(yt) Li forming metallic sulphates, as those of copper, zinc, and 
{ran ; in malting calomel, and corrosive suhlimate, and suphuric ether ; 
in disstJving mdigo, extractiog pbospbonis, 6ic. 

(g.) In medicine, largely cUlute(f~50 or 60 parts of water to 1 of 
afud.** Used as an antifebrile drink, and as a tonic and stimulant. It U 
also used externally as a caustic, and in the composition of elixir vi- 
iriol, be. Externally, as a gar^e in putrid sore throats, and aptbout 
ntouths, and as a wash in cutaneous diseases. In its conceotrated 
state, it is a violent poison, and the person who swallows much of il, 
dies in agtmy ; chalk and carbonate of magnesia, are the best rem- 
edies. 

10. DirrusiON in naturx. 

Largely in combination, as in the earthy and metallic sulphates, but 
not much known in a free slate ; occurs in that condition m the crt' 
tor of a volcano at Mount Idienne, b Java, &c. ; also, observed by 
JBaron Humboldt, in the river Vinagre, in the Andes of Popayan.f 

Found in the cavities of a small volcanic hill, called ZoccoHno, nee 
Sienna ; also, in the state of New York.J 

11. Test. — Mvriate cf barytet ; it acts by ^vii^ its earth to 
ibis acid, and by thus takmc it from every combination, it afibrds us 
an infaUible test lor the sulphuric acid ; the precipitate b a heavy 
nliite powder. 

12. PoLAHiTT. — Electro-negative; it is attracted to the pootiva 
pole in the galvanic series. 



* Or, M much M will mike it agreeable, and It nay be qualified with aagu- To 
pr«TeDtltaliijuriDg Ihe teeth, it a usual to auck it through a quill, but a glaM fiibe 
woaldtM belter. 

t Bodon Jour. Vol. 11, p. MO. i By Prof. Eaton— Am. Joor. Vol. XV, p. !>' 



DK;,lz=..,C00g[e 



INFLAMMABLES. 



Banark, — AccordiDg lo Berzelius, a minute ({uantity of tttatuum 
exists in the English acid, and of tellurium in that of Sweden. 



1. HiSTOHV. 

This gas being produced whenever sulphur li burned, it has proba- 
bly always been known, although it was not* recognized as a distinct 
chemical agent, until noticed by Stahl ; but it was first obtained pure 
by Dr. Priestley.* 

2. Prepahation. 

(a.) /n a glass globe or bottle, bum sulphur in common air, either 
in a pendent spoon,f or by means of a sulphur match ; sulphurous 
acid gas will be formed, and if there be litmus or cabbage infusion 
in the bottle, it will be reddened, and eventually the color will be des- 
troyed. 

(b.) The tame result is obtained with oxygen gas ; the combus- 
tion is brilliant, with a blue and white light, and the product is entire- 
ly sulphurous acid. There is no change in the volume of oxygen 
gas, but the weight is doubled. 

One volume of sulphur vapor unites witli one volume of oxygen. 

(c.) Red oxide of mercury and svlphur, equal parts, or sulphur 
13, and peroxide of manganese, 100 parts, mingled in powder 
and heated, produce sulphurous acid gas ; in the former case, one 
cubic inch is obtained for every 5 grains of the oxide ; the latter pro- 
cess b recommended as being a very good one. 

(d.) The best process is, by mercury 1 part, witk 6 or 7'\. of aul- 
phvric acid, in a. small glass retort; apply the heat of a lamp or of a 
Tew coals, and obtain tlie gas over mercury, or by a recurved tube 
passing to the bottom of a jar or bottle, and displacing the common 
air, as exhibited in tlie figure on p. 232, only substitudng an empty 
bottle for the bottle of water — theory, the mercury detaches 1 pro- 
portion of oxygen, and leaves the whole of the sulphur combined with 
the remaining two proportions of oxygen, and thus evolves the sul^^u- 
rous acid gas ; the sulphate of mercury which is formed, may be sav- 
ed for future use. 

(«.) Sulphuric acid is decomposed by foany other things; it may 
be boiled on charcoal, wood, straw, cork or almost any vegetable 



■OnAir, Vol. II,p. i. 

t FdDdont spoons arc easily mgule by cuKing ■ *lip oT iheet copper, lata Om form 
of > very icute isosceles triaof^ie, (be ihirp eod may be thniit Ibniagh ■ cock, lAd 
tbs other be himmeted iaio a ipoon aod turned il right miif let. 

F Metal 2. acid 8. (Turner,) with m> nnall a proportion of actd, than mltht b« 
danger oT breaklni; Ihe retort; It i« better louse an exceai of uld nMch e«B be (f-, 
lerwardi poured oif. Th^nard directs 6 or T of acid to I of mercwy. 

40 



D,„iz=. ./Google 



314 INFLAMMABLES. 

sabitance, and Eulf^urous acid gu will be obtained ; but there are 
other gases produced, and the process is much less neat than when 
merouiy or copper is employed ; Un answers equally vreU. 

3. CoMPOaiTIOM AKD PBOPXRTIES. 

(o.) Sulphurous acid gas is composed of 1 volume of sulphur in 
vapor, and 1 volume of oxygen condensed into one volume, f or we 
may say that the volume of the osygen gas is not changed, but an 
equal weight of sulphur is added to it. 

Itt ip. gr. being 2.22,* and that of oxygen gas 1.11, therefore 
the weight of the gas is divided equally between the oxygen, and the 
sulphur. 

[b.) 100 etihic inches weigh nearly 66grain»; accurately, itdiould 
be 67.776 grains, containing 33.888 of sulphur, that is, just half.t 

(c.) It it fatal to life, prwlucing spasms of 6ie glottis, and kilhng 
beta by suffocation and excoriation ; used to destroy bees.^ Intol- 
erably sufibcaung, disgusting, and distressing, even when breathed m 
moderate quantity, and mixed with much atr ; it creates a cougi 
and a stricture of the breast. 

(d.) Extiiiguitket eonUnution ; best shewn by a pendent candle 
let down into a jar of the gas, as exhibited in a note to p. 187 ; it 
may be extinguished many times, and then the gas may be poured 
upoa other candles, and will run down like water and extinguisli 
them. 

(e.) FvgadouMly reddena, atid looa hleachca the dark vegetable eol- 
vn. — A red rose becomes white in it, as may be beautiftilly shown 
by holding a red rose over a burning sulphur match, when it will be- 
come first variegated cuid then wliite, and immersion in water re- 
stores the color ; Utmus paper is first reddened and then becomes 
white. The color is not decomposed, for it can be restored by a 
stronger acid or by an alkali. — Turner. 

' {/) The aqtietmt toluiion u prepared by pasting the gat, With a 
recurved tube, tkrovek water, which, when kept cold by snow, ab- 
sorbs 33 times its volume ;|| or 100 grains absorb 8.3 oi the gas. 

(c".) The gat it tpontaneously disengaged into the air ; rapidly by 
sulpnunc acid. 

(A.) StUphuric add, saturated toith the ndpfmraus, crystallizet 
wiui a moderate reducti<Hi of heat ; when distilled, it crystallizes 
and becomes solid. 

(i.) JVot deeon^osed by heat. 



■ 3.04, Tbcnard— 2.2S, Tb. aud R.-Ltis. I Thomwin'a First PHn. I. 216. 

t Anii.da Cbim. cl de Phy>. Vol. V. 

J A gntuiloui cruelly, at Ihey can bo tiiii^fcrr^d to 'nolticr hive, and Uiu«> ^ 
tb« bceiuid tb* booeyeao t»e 7sved. || At 61°.~C7i. 



DMzidoyGoOglC 



INFLAMMABLES. 8|g 

(j.) If two measures of sulphurous acid gas and one of oxygen be 
mingled in ajar, standing over mercury, and a litde water be wlded, 
sulphuric acid will be formed ; the same result is obtained by paarii^ 
the mixed gases through a red hot tube, or causing the electric spark 
to pass through them. 

(*■) Becoma liquid by great cold ; or by moderate cold, — 31°, 
if sided by pressure. 

(I.) Decomposed when passed over ignited charcoal, or whb hy^ 
drogen, through a red hot tube ; water and sulphur are the products 

in.) Liquid sulphurous acid does not give up its gas by freezing, 
becomes so heavy as to sink m water. 

(n.) Bdling expels the gas, although the water remains acid, from 
the formation of sulphuric acid. 

(o.) Exposed to the air, the liquid acid becomes slowly sulphuric 
acid, absorbing oxygen gas from the air ; its smell is like that of the gas. 

(p.) Decompoted, by potauiwn* heated in it ; products, probab^ 
potassa and su^huret of potassium ; also, at ignition, by hydrogen, 
forming water and leaving sulphur ; and by carbon, producing cuw^ 
nic acid and carbonic oxide, and liberating sulphur. 

(j.J Sidpkarmu acid attract* oxygen powerfiiUy; it converts ^ 
peroxide into the protoxide of iron ; the same with maneaaese, and it 
precijHtates gold, platinum, and mercury in the metaUic state, be- 
cause their affinity for oxygen is feeble ; it becomes itself, in the 
mean time, sulphuric acid, by acquiring one proportion of oxygen. 

(r.) CondemaOon of tvipfutroiu Mid gat. — ^Mr. Fanday,f by 
confining, in a bent glass tube, both sulphuric acid and mercury, and 
applying heat, caused the sulphurous acid gas iriiich they produced 
by their reaction, to pass into the other end of the tube, cooled by a 
freemng mixture, and thus obtained the sulphurous acid in a Uquid 
state.' 1%e pressure was about two atmospheres. 

(>.) Mr. BuMtyX alto obtained the liquid anhydrout add, from 
the above named materials, by passing tlie dried gas into a vessel 
cooled by ice or snow, then through a tube cmtaimng melted muri- 
ate of lime, and finally into a matrass surrounded by a mixture of 
ice 3 parts and common salt 1 ; in this, the gas is condensed into a 
liquid, at the common atmospheric pressure.^ 

' It la decompoMd In ths Mme muin*r by ndinm. 

1 PhU. Tr»M. 1B2S, p. 190. 

t Aon. PhU. Vol. Vlil, p. 807. N. S. 

i H. A. de !■ RJve (Bib. Univ. Hin, I8S0, mi Am. Jmt. TdI. XTil, p. IM.) 
direct!, thit ■ •ecODd tube, filled wllfa muriate oT lime, ahould ]mm fram Oie aacMtd 
toilhirdTeHd cooled Ilka the Mbcn, and (rom thit • tube nay prncced to the B*r> 
curia] dstcrn. The juncturea moat be luted tifht. Tba gae haTioy been dlaaon- 

Sid during S or 10 houn, wblts cryat»b, (hjpdralei) mre firnnd in tha TMad No. 1 ; 
ay rcMmble the hydrate of chlorine i they ara nid U nmtiit aoUd ■! I^er B* (ee)«(k 
gnid« ;) ud In No*. 2 and S, li (he Hqtiid nilphurou* add, which nuft be immedlatalr 



OMzcdoyGoOgle 



316 1NF[.AMMABIJ:S. 

((.) Sir H. Davy, substitutkig the pressure of the vapor ofeibCT for 
thu of the gu itself, and causing the former, tlirough the medium of 
tnercury id the bend of the tube, to press upon the latier in the other 
ler, while cold was applied, succeeded in ctwdensing (he sulphurous 
acid into a fluid.* 

4. pROPKRTIEfl OF THE LIQ171F1ED CAS. 

(a.) lAmmd, tolorless, refractive power similar to that of water ; 
when the tube was opened it evaporated rafndly, but widiout explo- 
sion. 

(6.) Sp. er. 1 .45 — hoil$ at 14° FoAr. and evaporates rapidly, but 
without expliDsion, cooling the residuary fluid to 0, so that it re- 
mains some time liquid under the pressure of the atmosphere. 

(c.) Ao viaAh fumet, but a strong mutt of tuiplmroiu acid, 
eventually leaving the tube dry. 

(d.) Ice dropped into the fluid, proved so much warmer, that the 
ice made the fiuid boil. 

(e.) Mercury it frozen by the cold produced by the evaporation 
ofndphwrotu add / for this purpose the ball of a thermoineter tube 
is surrounded with cotton, and kept wet with the liquid. 

(/.) By its aid, and that of a moderate pressure, several additirai- 
al gases have been liquified.')- The cold was canied to —60°, but 
absolute alcohol and ether did not freeze. One part of the acid 
in a watch glass, freezes, by tiie spontaneous evaporation of the 
other. 

5. Combining weight. 

Sidphurous acid consists of 1 proportion of sulphur 16,+^ of oxy- 
gen 16^33, which is therefore its equivalent number. 

6. PoLABiTT. — Like other acids, it it electro negatiee, as it is 
attracted to the positive pole in the galvanic arrangement. 

7. Sulphurous acid in volcanos and sol-faterras. — It is 
constantly emitted wherever volcanic fires are active. This arises 
from the combustion of sulphur, raised by the subterranean heat, 
and burned by the air in its passat^e. Those who visit volcanic cra- 
ters and solfaterras are constaiidy incommoded by this gas, and often 
find it necessary to mount some elevation in order to escape from 
suffi>cation. 



CQrb«d Ught, and the vaMel muat be coiuilant]; a 
elw the K** will Hcape, or the veuel explode. 
nnii KMlhrown upon water, produces s cruat oflcc. 

If Bercary, of the volume ofmhazleDul,!* moiMenod by k few drops of the acid, 
md tho Ipptratua plued under an esbaunled receiver, the metal icill freeze wild, 
Md ■ connderable mnaa may bo Ihua frozen and preten'eri for a feir inlnutea. Il U 
found Aat tolld nereury !■ a much better cooductor of eiectriciiy ihui the Quid 
natal. Ib it* pare liquid Mate, It was not decomponed by electricity, but If a Utile 
water WM added, lalphDretted hydrogen appeared at one pole, and oiygeo at the 
otktr. 

* See Faraday"* Cheixical Hulp. p. SOS. t Ann. Riil. N. S.' Vol. VIII, p. 307. 



OMzcdoyGoOt^IC 



INFLAMHABLLS. 317 

8. Uses, IN BLEACHING, and for Other pUTfotss.* 
(a.) /( bleaches straw, tmtolen and silk, and gives tHk lustre. 
— Sulphur is burned in a barrel, in family operations ; the articles 
to be bleached are hung up in the barrel, and moistened with water or 
solution of pearlashes.f It also discharges iron moulds and vegeta- 
ble stains from linen. For this purpose, the places must be made 
thoroughly damp, and then two or three sulphur matches must be 
burned close to them; liquid sulphurous acid will thus be forroedj 
and the spots will soon disappear. 

(A.) A similar process is practised on a lai^e scale in the arts ; 
the sulphur is burned in chambers lined with sheet lead, and the 
moistened articles are hung upon frames. J 

(c.) Prepared of a proper strength for liquid bleaching, by dis- 
tilling in a glass retort 1 lb. of wood shavings, with the same weight 
of sulphuric acid, and placing two gallons of water in the receiver ; 
if to be usej) to stop the fermentation of wine, only two quarts of 
water are placed in the receiver. 

(d.) A rag, imbued with sulphur, is s<»netimes burned in cnler 
castes topreserve the cider from too rapid fermentation. 

(e.) The fumes of burning sulphur, (or in other words, sulphurous 
acid gas,) were employed 1600 years ago in bleaching wool ; but 
the gas whitens only the surface, and therefore the liquid a<ud is pre- 
ferred. 

(/) Th^nard says§ that the sulphurous acid is beginmng to be 
used to cure diseases of the skin — that there are in various hospit- 
als in Paris, badis of this kind — that a few applications suffice to 
remove psora, and that the tetters yield to the continued use of 
this remedy. It is said that Dr. Gides, of Paris appliesj| the vapor 
of burning sulphur mixed with air, to the surface of the body, as an 
air bath, with much advantage in many chronic diseases of the joints, 
the glands, and the lymphatics. — Ure. 

• •***#• 

Dr. Torrey informs me tliat he has made the liquid sulphurous 
acid before his class, and that tubes of it may be sealed by the blow- 
pipe, while immersed, (except the capillary extremity,) in a freezing 



The hypo- or sub-sulphurous, and the hypo- or sub-su)phni 
win be mentioned alter the sulphates and sulphites. 



* See ParkEB on Bleaching. Exiays, Vol. H, p. 337. 

I Water woulil probably tie bettor, *i (h« alhati woiihl neulralixe a purl of the 
■dd JM, tod withdraw it from actioD. 
t VeTbal communicitlDn to the author while in E^BEUad, Trom ■ manufiiolurei. 
§ FiAbEd. Vn,p. 165. 
j[ In in appantua called Boite rumigatoire. 



c.,i,=ji,G(10glc 



tniroducfory Rtauirlu. 

That the student may not be fatigued by a too frequent reiteraiion 
of similar properties, the history of saline bodies will be giren, m (fi- 
vimons, under that of the acids, which they respectively- contaia, ia ibe 
same manner as that of the prmcipal acids is given, under combustibles. 

We shall thus dispose of the salts in convenient groups, and the 
most important will be brought into view, as early as possible. 

As many of the salts are unimportant, the histoiy of some of (baa 
will be abridged, and that of others omitted, or mcluded in a general 
statement of the properties of the genus to which diey belong. Some 
of the salts are, however, eminently important and interestii^ bimI 
therefore the history of such salts will be developed, with all £e ne- 
cessary details. Under the head of attraction and ciystallizaiioii, 
many things have been stated respecting sahoe bodies, which need 
not be repeated here, and various generalizad<His will be prefixed b> 
the first genus. It remains, to mBKe a few other observadons, by 
way of mtroductim to the history of saline bodies eeaerally. 

As salts consist of acids and salifiable bases ; aualies, earths, and 
metallic oxides, we observe that the powers of saturation difier very 
widely among these agents j it takes much more of some bases to satur^ 
ate a given acid than of others, and vice versa, of difierent acids to 
saturate a given base. This evidently depends upon the number ex- 
pressing the combiniDg powers of those difiereot bodies ; or rather 
the formation of salts is only a mode of ascertaining and expressing 
this very fact, in relatioD to acids and bases. For instance, tne com- 
binine power of nitric acid is expressed by 54, that of luiie by 28, 
and that of baryta by 78 ; to form then ^ihydrous nitrate of lime, 
54 parts of nitric acid wUl unite with 28 of lime, and the chemical 
equivalent of nitrate of lime will be 54-|- 28=82; but to saturate 54 
of nitric acid, requires 78 of baryta, and therefore the chemical 
equivalent of nitrate of baryta will be 54+78=133. 

Now, suppose lime ana baryta to he combined, each widi two 
acids ; say the nitric and the sulphuric ; the numbers expressing the 
combining powers of these earths being as above stated, and that of 
sulphuric acid being 40, the sulphate of baryta will be expressed by 
404-78=118, and that of the sulphate of lime by 40+28=66, tbe 
salts bemg supposed anhydrous. It was suggested by Berthollel, and 
the idea was adopted, m(»re or less, by many chemists, that die 
strength of affini^ is inversely as the saturating power ; but this idea 
is inconsisient with facts ; e. g. 40 parts of sulphuric acid require 38 
of Ume and 78 of baryta for saturation, and therefore baiyta should 
attract sulphuric acid less powerfully than lime, which is not true. 



OMzcdoyGoOglC 



TWpIe Saiti are those which have two bases united to one acid, 
as the pho^hate of soda aod ammonis ; this may be regarded as two 
phosphates combined, or as a' phosphate of two bases; some prefer 
to c^ such combinations double salts. 

JVeutral Salts were formerly regarded as those in which the pro- 
perties of the acid and base are both entirely lost, as ia sulphate of 
potassa ; but sometimes there are pecuUar characters imparted by 
the acid or base, more commonly by the latter ; e. g. the sahs of am- ' 
monia are volatile ; of magnesia bitter ; of alumina s^tic ; and of 
glucina sweet, llie nio^tes are cooUng, and they deflagrate with red 
hot charcoal. In general, a salt is said to be insoluble, if it requires 
1000 parts of water for its solution. 

Salts are not only compound bodies, but the acids and bases of 
which they consist, are also compound. Thus, in sulphate of soda, 
the acid is composed of oxygen and sulphur, and the base of oxygen 
and sodium. It has been imagined by stune, that in salts, (he ele- 
ments, losmg the form of acids and bases, are directly united to 
each other, so as to produce lemary or auatemary compoimds. 
Thus, in sulphate of soda, the oxygen, which exists in the add, ia 
the base, and b the water of ciystaUization ; the sulphur of the acid ; 
the sodium of the base, and the hydrogen of the water, are regarded 
as bemg in immediate union, to form a quaternary compound ; 
but of ihe truth of this speculation there is no direct proof; and 
it is estreroely improbable that it is true, because the acid, the base 
and the water can be combined synthetically, to form the sah ; 
the water can be expelled by heat and recovered, and the galvanic 
power will separate the acid and alkaU unaltered, in full proportitHi, 
and we know not of any affinity which should unite these bodies in 
a quaternary combination, and then resolve them again into binary 
compounds. 

NOHENCLATUKE AND CHARACTER OT SALTS. 

1. At ahnott every acid unite* leitk nearly every bate, and some- 
times in more than one proportion, it follows that the salts are very 



2. They are raid to ejxeed 2000, although not more than thir^ 
were known fifty years ago. 

3. The old namei toere lomeiimes batiarous, abturd, or falte, un- 
piying incorrect ideas. 

4. The nomenclature of the French chemists," is emineudy use- 
fid in the study of the salts. 

5. Every lalt caiuiatt ofaa acid and a saiifiahle bate, and the 
bases, except ammonia, are all oxides of metals or of inflammable 
bodies. 

* Sec page BS. 



OMzcdoyGoOgle 



6. 7^ genera are derived from the add* ; the spede* Jrom tie 
bates, thus all that cootain sulphuric acid are sulphates ; all that coo- 
tain nitric acid are nitrates, tic. 

7. The bates are the oxides* of which there are three divisioiia j the 
alkalies, the earths, and the other metallic oxides. 

8. Every base that conUnnes with adds, fumithet a species ; thus 
sulphuric acid with potassa, soda, and ammonia fonus a sulphate <rf 
each of those bases. 

9. The lermiaation ate, corresponds widi the acid, n-bose tennina- 
tkui is in tc, and the termination ite, with the acid whose ternunatioDisiD 
otM ; thus, sulphuric acid gives sulphates ; sulphurous acid suljdutes. 

10. There are some acids containing leas oxygen than those thai 
terminate iu oUs ; in sltch case, the word hypo is prefixed ; thus we 
have hypo-sulphurous acid, hypo-nitrous acid, giving also salts that 
are called hypo-sulphites, and hypo-nitrites. 

1 1. It was formerly supposed, that tliere is sometimes an excess of 
acid in a salt, in which case, the preposition super or hyper was prfr 
fixed ; and on the other hand, that there is, in particular cases, a de- 
ficiency of acid or an excess of base, and then the preposilJoo Mi 
was prefixed ; thus, there was a super-sulphate of potassa, and a suh- 
carbonate of potassa. 

Now, salts widi excess of acid are distinguished by the prefix, 
bi$ or bi; thus we iiave 6i-sulphate and M-carbonate of potas- 
sa} because in these salts, there is just twice ss much acid as in 
the carbonates of the same base. In some salts, the double propor- 
tion is again doubled, and then the word qtiadro is prefiixed ; .(^ 
there is oxalate, 6tn-oxalale and qtutdr-oxdaxe of potash, imply^ 
one, two, and four equicalents of the acid to one of the base. ^Cbe 
word su^ is now banished from the nomeoclature of salts ;t but 
atih Is sull retained by some, where there are two or more pri^ior- 
bons of the base. But, Dr. Thomson]! has proposed to use the 
Greek numeral words, dis, iris, tetrakis, to denote the proportions of 
base in a sub-salt ; thus, r/i-sulpliale of alumina contains one propor- 
tion of acid and two of the earth, but this nomenclature has not yel 
obtained general currency. 

12. Salts are generally, hut not aheays sapid. — The first idea was 
derived from common salt ; but many earthy salts are insipid, e. g- 
sulphate of lime, carbonate of lime, fac. and such salts are generally 
insoluble. 

13. Salts are generally, bat not vnivenally soluble in leater; the 
alkaline salts are all soluble, but earthy and metallic salts have swne- 
umes one character and sometimes the otlier. A salt is said to be 

* Ammonii excepted. 

t It may be, and oDon u nlill uacd in n vague and popular sentc. 
t Dr. Tliomson ha:^ blroduei^d (he woril stiqui, where there la supposed la be i 
half of an oquivaleut. 



D„tiidD,GoOglc 



SALTS-SULPHATES. 331 

insoluble, if it requires more iban 1000 parts of water for its boIu- 
doD. 

14. Jncom&tufti/e, with a few exceptions. 

15. CryitaUizabU, either by natural or arti&cial processes. 

16. Saturaiion between acid and base is determined — 

(a.) By th€ taite, which, when there is one equivalent of each, 
betiomes saline, or at least, ceases to be acid or alkalme. 

U>.\ By the absence of any effect on test colon, 

ic.) In the case of a carbonate ; by the cettation o/* effervetcetux. 

(d.) A scale or table of chemicd equivalents, uiniishes at once 
the information deured, as to the quanti^ of the one agent necessary 
to saturate the other. 

17. Saltt precipitate, ^ they areiniolithh tn VMier,* or much less 
soluble than their constituent principles — 

SaA In powder, as sulphate of baryta. 
b.) In cryttaU, as sulphate of potassa, if formed from concentra- 
ted acid and alkali. 

18. i)''n>/ui^, <A^ remain tn Wu(M»i, as most alkaUne, and many 
earthy and metallic salts do. 

19. The name of a salt expresses its compoution, and the knowl- 
edge of the composition recals the name. 

30. The nomenclature is therefore founded upon the most correct 
logical principles. 

31. The tfdts are, on the whole, very important, to arts, science, 
and domestic economy. Some of them exist in vast abundance. 

SULPHATES OF AI.KALIES AND EABTHB. — General Choroctert, 
1. Formed by sulphuric acid and a base. 
3. Generally crystalfizable. 

3. Not decomposable by heat, or only partially so, (except the sul* 
[^ate of ammonia.) 

4. Decomposable, (with the same exception,) by ignition with 
charcoal, being converted into sulphurets. 

5. Have generally a bitter taste, if any. 

6. Decomposed by all the barytic salts, except su^hate of baryta ; 
the precipitate is insoluble in acetic acid. 

7. Precipitated from their aqueous solutions, by alcohol, and in 
genera], crystallized. 

SULPHATE or POTASSA. 

1. Phxparation. 

(a.) By sulphuric acid and dilute solution of potassa, or of carbo- 
nate of potassa, mingled till test paper is no hnger afifected, or efier- 
vescence ceases. 

* SuppofiuE the buw, or perhtpi both iddi and btaei. to htve been prarSmiljr 
in iqncons HHiitloD, 



D„tiidD,Googlc 



333 SALTS— SULPHATES. 

(b.) Evaporation ^ves regular crysuls, whose form is that of six 
Bided prisms, sometimes crowned by six »ded pyramids. 

3. HiSTOBT. — Long known, and had formerly a roultitude of 
names,* which were banished when it received its present denomink- 
tion. 

3. Properties. 

(a.) Taste, acrid and bitter— sp. gr. 2.29, or 2.40, eaidly polve- 
rized. 

^4.) Al 212", requires five times, and at 60°, sdxteen dmes its 
weight of water for solution. 

(e.) Not affected by the air. On burning coals, or red hot inxi, it 
decrepitates. 

(<I.) Contains no water of crystallization. 

4. CoMFOsiTioK. — Acid, 45.4&; polassa, 54.66, or acid, 1 propor- 
tiOD,40; potassa, 1 proportion, 48=88, which bits equivalent numoer. 

5. De COMPOS ITIOPT. 

(a.) By Mtda, — Although the sulphuric acid has a stronger aSpity 
for potassa, than any other acid has, still the nitric and muriatic acids, 
in large quantities, decompose it in part ; the products are much bi- 
sulphate of potassa, and some nitrate and muriate of potassa. 

Not owing to the capriciousness of chemical attraction, but accord- 
ing to Bertbollet, to the influence of quanti^, compmsatiiig for inte- 
rior force of attraction. 

fb.) By barytic and strontitic water, ottractiog the sulphuric acid, 
c.) Also, by nitrate and muriate of lime, by double elective at- 
tractioii. 

{d.) By heating it with charcoal powder, when it becomes a sul- 
phuret, and can be decomposed in Uie palm of the hand, by vinegar 
or other weak acid, thus uilfilling Stalil's boast, but not as it was in- 
tended by him, that odiers should understand it. 

(e.) Other processa. — Saw dust substituted for charcoal, and py- 
roligneous acid for the vinegar, and the acid is afterwards decom- 
posed by heat. — DundonaJd. 

Sulphate of potassa, 100 parts, chalk 100, charcoal 50, heat 
them — sulphuret of lime is formed, and tiie alkali being liberated, 
may be obtained by lixiviation.f 

6. Uses, &c. — JCalled in die shops, vitriolated tartar, and used 
as a purgative or alterative — dose, half an oz. or less ; the effect less 
transient than that of sulphate of soda. The sal polycrest of the old 
physicians was made by deflagrating nitre and sulphur, and was b 



* TltrioUied md vltriolatcd t&rUr, s>1 do diiobu!i, armnmn ilaplicntum, sal H- 
yarect, nit of Gluer, vitriol of poluh, vitrialated rcfielablc alkali. &c. but vtlrl- 
sUted tartar wt« the nuMt general name. Iloncc, mil t'roin rimilar cases, the na- 
costly of the new nomendalurc ofllm ^alla. 

t-Ann-iJeCliiui. Vol. XIX. 



OMzcdoyGoOt^IC 



SALTS-8ULPHAT£a. 333 

compound of sulcAste and sulphite of poUssa. The finest neutral 
crystals of this salt are obtained when acid predominates in the mix- 
ture. 

Not found among mineral bodies, but exists in some animal fluids, 
and in the ashes and juices of some vegetables, as tobacco.* 

BI-SULPHATE OF POTAE3A. 

I . Preparation. — By heating together three parts of nilf^te of 
potassa, and one of sulphuric acid ; discovered by Rouelle sentCN- ; 
may be obtained m needle formed crystals, and even in six nded 
prisms. 

3. PROPEKTIBS. 

(aA Soluble in 2 parts of water, at 60°, and in less at 212°. 

(b.) Melts readiW, with the appearance of oil, but becomes of an 
opake white on coojng ; heated for a kmg time, its superfluous add 
is dissipated, and it becomes sulphate of potassa, 

(«.) Taste acrid ; reddens the blue test colors. 

{d.) The bi-sulphate is usually obtained in the process for nitric 
acid. 

(e.) With ice, it generates cold. f Of little use, except to form the 
sulphate, winch is done by neutralizing the excess of acid by chalk ; 
it may be used in crystalhzing alum, and is sometimes employed as 
a flux. 

After the process for nitric acid, if the sah, while still fluid, is pour- 
ed into a pan, it effloresces most beautifully in the course of a few 
months, presenting a delicate downy coating of crystalline filaments, 
which make their way over and down the sides of the vessel ; if it 
is glazed, the glazing will peal off and leave the naked biscuit. 

It contains two proportions of sulphuric acid, and one of potassa, 
40x2=60 acid, -j- 48 potassa = 128 for its equivalent. 

SITLPHATE or SODA. 

1. Names. — Named Glauber's salt, after a German chemist, who 
discovered it in the residuum of the process for muriatic add. 

3. Natural bistort. 

(a.) Found in sea water, and in the ashes of marine vegetables, 
ana in kelp. 

(b.) In the earth, near Astrachak.}; 

(c.) In salt and mineral springs. 

[d.) Often effloresces at the surbce of the ground, upon the walb 
of subterraneous edifices and other builduigs. 



OMzcdoyGoOglc 



334 iALTS-SULPHATES. 

(e.) Pound in the ashes of old wood, and in some plants, pflrticu> 
lam tamarisk.* 

(f.)la large proportion in die Glauberite of Spain. 

3. Pbeparation. — By^ saturating a solution of soda or its carbo- 
nate with sulphuric acid, but the quantity produced in the manulao 
ture of muriatic acid, and chlorine, and that can be made from sea 
water, is much greater than can be consumed. 

4. Pbofibtibb. 

(a.) Crystallizes in transparent six sided [vigms, with dihedral 
•ujuaiits, utuallv striated at tne edges, and often very irregular. 

(&.) Taste bitter, and dissolves easily in the niouth ; auSen readilj* 
the wat^T fusion ; then dries and melts, with the true igneous fuskm. 

(c.) E^Cffesces in the air — loses half its weight, and thus becomes, 
u a medicine, twice as strong ; by a high heat, a part of the acid is 
driven o£ 

(d.) Soluble in 3.67 of water at 60°, and in .8, at 212 ;t in this 
respect, strongly contrasted with sulphate of potassa. The hot solu- 
tioD of Bolphate of soda, crystallizes by cooling, | and vrhea the quan- 
tity is great, the crystals are very large, scxnetimes half a yard in 
length, and several inches in diameter.^ 

5. Composition. — ^When anhydrous. 

Acid, 55.55 or 1 proportioii 40 
Soda, 44.45 or 1 " 32 

100. 72 its representative number. 

• Tftr. Ill, 42. 

t lqjudgti^irfthaM]lDbintjofanlt.wa niuit irat put Ibe nh Into wtlar, lod 
•xpoM Ibat wkler dlrecUjr to hear, but immarfe the veiw] coDt^ning the ull En a 
water batb. In which Ihp EhermaDietar li plieod. 

t At 70°, water dlHolvei nearly half lU weight, twice its weight at 88°, aDil >J af 
ita wdfht at ID*°, at any higher degree, >ome ufihe aalt ti deposited in op^ mhj- 
droaic?*Blali,ao that It erowt leMioluhle with otorebeBt. — Turner. 

) Hum aatunted boiling aolution of thia salt be made with ci 



8a*, ai 



a malruior 



a tgitatkia, it may be reduced to the taniperilure of the air with- 
CloM the veaael by a slop cock at Ihe top, or ■ i 



out cr7*talliiing. CioM the veiwl by a slop cock at Ihe top, or ■ good cork, the la- 
Hani twfbre it ll witbdraWD from the fire, and while still boiling. SamelirneeoD Dpeil' 
luoroQ agitating the aolution, and always on ttironingla a crystal , (any crrital or 
Mi wUI do, but betlerone of the aame aalt,) nearly the whole fluid will rapidly erya- 
blha, and tfaa lemperature will rlae considerably. The balance of lorcea becwMU 
l *»*a ud repuWon li disturbed by agitation, or by a cryalal atfiirding a nueleiH. 
TTwjBtas w ire otthe atmosphereaclioaly aaadiaturbingfbrcfl, aodanyMherdiiturb- 



idnlatinint aulphale of eoda, placed orer mercury, pre*looily heated 

to 110" «r ISO", will cool without cryitalliziog, bat thai if a bubble of air, m 
if any gaa, especially of thoee thai are solublo To water, or a portion of any fluid 
Aat attracts water, as alcohol, be thrown up into Ihe eolutlon, it will immediately 
crystallize. Hence it la eimeluded that (he influence of air In caiuing the ctjs^- 
lization in Ihli well known expeilment, ia awing to the solutioo of a portlwi of It, 
wMeh thm deprirea the aalt oi a part of It* water, and caaaes tbc cryalaUitatiiu la 



OMzcdoyGoOt^IC 



SALTS-SULPHATES. 335 

The crystals, 

A^d, 24.70 or 1 proportion =3>40 
Soda, 19.75 1 « =^ 

Water, 66.55 10 " =90 

100. 162 its eqaivaleat number. 

fi. DeooHPOeiTioK. 

(a.) By combustibles, egpectallj charcoal ; the same as that of sul- 
phate of potassa. Immecse quantities are produced io makiDg muri- 
atic acid, aod in other manufactures ; therefora its cheap and eSfactual 
decomposition is an object of vast impcHtance for the sate c^ the soda. 

J&.) Potassa will do it, but die price of labor forbids, although 
a IS dearer than potn^. 

(e.) Decomposed (via humida,) by no acid, hut it dissolves readily 
in the nitric, muriatic and sulphuric acids, producmp cold. 4 parts 
sulphuric acid with 5 of this salt produce 47° of txAa; 2 parts nitric 
acid with 2 water and 3 of this, jKoduce more oold than the last mix- 
ture } 5 muriatic, and 8 of this salt, krm a considerably powerfnt 
mixture. 

(d.) Surytz and strtHHiB decompose it, taking its acid. 

UsBs.— It is the most common domestic cathanio,and is called jo^; 
doseloz.perh&psmoretoften l^o2. Used^lsoinsmaUdihiteddoses, 
as a diuretic and aperient'. The effloresced salts must be given in half 
4ie quantity. It ts now used in the manufacture of glass, p. 280 (6.) 



: OF SODA. 

Formed by sddmg sulphuric acid to a hot soluticHi of sulphate of soda; 
product, large rhon^dal crystals ; efflorescent, soluble in twice their 
wet^ of wat« at 60° ; lose their excess of acid by heat.— -fiewy< 

StJLPHATX OF AJUOMIA. 

1. HisTOBT, Name, &c. — Discovered by Glauber, who caDed 
it ncrei tal ammtmiae ; other names — ntriotated ammoniac, viiriol- 
ated volatile alkali, &c. Found in the vicinity of volcanos, and in 
the waters of the Tuscan lakes ; also in the ashes and soot of pit 
coal.* 

2. PftCFARATioN.— By mingling sulphuric acid 88 puts, and 
eonmact carbontue of ammonia 100 parts, to mutual saturation, or 
by decomposing muriate of ammonia, by sulphuric acid. 

3. Profertiss. 

' (a.) The crystals are long six mded prisms, crowned with tax 
sided pyramids; sometimes in plates, alky fibres^ or chigters of 
needles, f 

'lib not probiblo thtt the ammaoU eiisti in the coal, but the oitro^a of the 
■Ir and (he hydrogen of the coal form the immonla ; the oxygen of the air, with the 
•nlpbnr of the coal, toata (he iDlphuric add, aDd Am Is doubtleM the origin of the 
■niphate of amiramiB in the aiiat and ashea, t Four. Vol. Ill, p. S9, 



D„tiidD,Googlc 



32d SALT»-SnLPHATE8. 

(b.) Taste sharp and biuer. 

U.) Solubility at 60° ; water 1, salt 2 ; at 212°, equal parta. 
id.) During its solinioa it produces cold, 
h.) Little affected by the air, or slightly efflorescent. 
(/.) Heated, sufiers watery fusion, sublimes in part, and is then 
sour, and reddens vegetable blues. By a sull higher heat, com- 
pletely decomposed, and resolved into nitrogen, water, and sulpfau- 
tons acid. 

6. Composition. 

Add, 63.1 or 1 profKir. =40 
Ammoaia, 22.6 1 " =17 

Water, 24.3 2 " =1B 

100.0 75 its equivalent number. 

If water be subtracted, it leaves 57 for anhydrous sulphate, which 
is known only in theory. Dr. Thomson admits but (me proportion 
of water, in Uie crystaUized salt, which would reduce its equivalent 
to 66. 

6. Decomposition. 

(a.\ The nitric and the muriatic adds decompose about i of the sik. 

(b.) Potassa and soda, baryta, strontia and lime, tiberUe the gas 
ammonia, forming a sulphate of the base. Su^ate of soda, and 
sulphate of ammonia, when mingled, form a triple ciystallizable salt.* 

(c.) Deflagrates with melted nitre, being resolved into watec and 
nitrogen. 

SULPHATE or LIME. 

1. PnsPABATioN, Natubai. Hibtobt, Uc. — Formed by the mu- 
tual action of diluted sulphuric acid and marble, or chalk, or by ^ 
same acid and any soluble calcareous salt, or Hme water; the sul- 
f^ate precipitates. 

2. Fbofekties. 

iaA Melts before the blowpipe, and in furnace heats. 
b.) Solubili^ in cold water, 500 parts to 1, in 450 at 313°, and 
crystallizes on cooling. Soluble entirely in dilute nitric acid. 

(c.) Causes waters to be hard, — decomposing the soap that is 
mingled with them ; the add unites with the alkali, and the dl with 
the earth, to form an earthy soap ; by adding solution oiaoap to so- 
lution of sulphate of lime, this efiectia manifested. 

(d.) Thrown down by alcohol from its aqueous solution. 

(e.) Decomposed by boiling with baryta, strontia, potassa and soda, 
and by their carbonates, or at least by those of the fixed alkalies ; . 
see those articles. 



d.^Goot^Ie 



SALTS-BULPHATES. SS-J 

{/•) Insipid and bannless ; sp. gr. of the native salt about 3.26 to 
3.31. 

3. Composition. — According to Dalton, 58.60 acid, 41.40 base. 
Berzelius and Thomson 5B. and 42. Dr. Henry thinks its true con- 
stitution is, Acid, 58.42, or 1 proportion, - - = 40 

Lime, 41.68, or 1 " ... -28 

100.00 68 

Crystallized sulphate of lime is composed of, 
Sulphate of lime, 70.07, or 1 proportion, (anhydrous,) 68 
Water, - 20.93, or 2 " - 18 

100.00 86 

4. Uses and miscellanboos reuarks. 

(d.) The native salt is abundant, in the form of alabaster, gypsum, 
or plaster stone, selenite crystals. Sic. Found in the ashes of vege- 
tables, in the sea, and in many natural waters ; producing incrusta- 
tions upon the pans of the salt boilers.* 

There is a native variety without water, called the anhydrite, but 
It* is rare, and its properties are different from those of the coimnoD 
kind.-l- 

(b.) Heated, it loses weight .32, and if in a retort, water may be 
collected. 

(c.) Exhibits a false appearance of boiling, in consequence of the 
escape of the water ; this is best shewn in a glass retort, with the Ia> 
meUated variety ; it may be seen in a crucible with a forge heat. 

[d.) Thus prepared tor statuary and stucco work. Heat the plas- 
ter thoroughly, pulverize it fine, mix with a little good quick lime in 
fine powder, and form into a paste with water. 

(e.) To copy a medal or coin, pour the paste into a box, oil the 
suriace of the medal to prevent adhesion, and brush it over with the 
cream of the plaster to prevent air holes ; then impress it upon the 
paste and let it harden. 

(/.) To copy a face, living or dead, or a statue ; the process is 
the same, only laying the 6gure on a table, oiling the surface, and if a 
living person, putting paper tubes in the nostrils, tying the hair back, 
and pouring on the plaster of the consistence of a thick cream. The 
muscles are kept composed, and in about 20 minutes, the cast will 
grow firm, when it is removed. After formmg the concave copy, the 
convex is cast in it, and any mistakes are corrected or additions made ; 
then a new concave is made upon this and serves as a permanent 
mould ; statues are cast in parts and then Joined. For stucco work. 



' And in the boilen of the alBaui btnts, thai use lall wUar. 

I II is (bund lo be inucb more commou tlian was lorDiuly Hi|ipo(ied. 



OMzcdoyGoOgle 



83B SALTS-SULPHATES. 

the plister is cast in moulds, or figured on the spot to irtnch it is ap- 
plied. 

fr.) Sometinies used to adojterate flour. 

(a.) Discovered by weighing a given measure, by grittioess be- 
tween the teeth, by alcohol throwing it down Irom water that has been 
boiled on the flour, by the testa for lime and sulphuric acid, by burn- 
ing the flour in the open air, and examining the residuum and by 
forming heavy bread. 

Besides the uses of this salt for statues, Uc. it is emplojped in cer- 
tain proportions with common lime plaster, to give it firmness and 
beauty, and such walls will bear washing and cleaning ^th so^- h 
is lai^ely and most advantageously employed in agriculture as ■ 
manure, on sandy soils and grass lands.* It is extensively used in 
Switzerland, but very little, a at all, in Great Britain. It need not 
be burned, but merely pulverized. At Paris, and b MiatxrcB, H n 
employed in building houses. Abundant io Nova Scotia, and in many 
of the Western American States ; a very beautifid transparent va- 
riety is found at Lockport, and the compact variety exists extensire- 
ly in other places in the state of New York. 

BVLTBAn or BUtTTA. 

1. Naub, 8tc. 

(a.) The native mineral formerly called ponderoui tpar ; its sp. 
gr. being from 4.3 to 4.7. 

(i.) Its compo»tion first ascertained by Gban. 

2. NaTURAI. HtSTORV. 

(a.) Found native, in almost every country, particularly in metal- 
lic veins, of which it often forms the gangue ; it is frequently amorphous, 
compact or granular, and of a pure white, or red, brown, yellow, &c. 

(&.) Often crystallized, ,or fibrous, translucent, transparent nr 
opake.f 

3. PaxrARATiON. — By mingling harytic water or any solvile talt 
cf baryta, with tulphuric add or any tolubU tail eontatntng it ; there 
is an immediate dense precipitate. 

4. Pbofebtiks. 

(a.) By heat, the foliated naturtU nUphaie deertpitata, and mehs 
under the blowpipe, at about 35*^, Wedg. 

(b.) Tasteless and inodorous, insoluble io water ; or requires ac- 
cording to Kirwan, 43,000 parts of water. 

* Hie popalar opiDtoD that ft nlll not ■nnrei'Detr Hw scr, ippearv to be tmotixUi 
M wu proTod by Ihs lile Hr. M. Rogcn, at bU place, near Stamlbrd, CMk 
where, at 1 beard hiio ray. It produced tbe most atrfkiag e^li on land waibed vj 
tbe aalt water. Dr. Blacknyi Ita e fleets lut two yean, and be WHrti, coomry «> 
oar Imprairioiu in Ibii 'country, (bat ll ia (dckI efflcaehnu on atraog and ricb laad*- 

I Pinmd tomelimet in $iaid»lone, io ieotland ; rarely, In the aame countrTi <^ 
Ipranile, in the place of ihe fetuar ; a«MMooilly In the Interior of Scotdi tplei, »» 
in the ludui helmootli, irf England. 



OMzcdoyGoOgle 



SALTS— SULPHATES. 329 

(e.) Sotuhle tn conceMraied ndphuric acid, especially if boiling, 
but again precipitated by water.* 

(di) Decomptued by ignition with charcoal ; its oxygen is separated 
in the form of carboDic acid, and sulphuret of barium is left. 

(e.) Pulveri^d, kneaded up witkjUmr and toater, formed into a 
thin cake and exposed to ignition, it becomes photphoresctnt in the 
dark.-|- 

6. Composition. — Dr. Henry, after citing several analyses, pwi- 
cludea that [he true compoution is, 

Acid, 33.90, 1 proportion, . . 40 
Earth, 66.10, " - - - 78 

100.00 1 18, its equivalent. 

As baryta is used to separate sulphuric acid from all its combina- 
tions, thu talt it very important in analyttM. The quantity is deter- 
mined by weighing the precipitate, previously washed and dtied, and 
alloning 33.9 per cent, of its wei^t, " for real sulphuric acid," thus 
shewing the quantity in any sulphate. | Sulphuric acid or any solu- 
ble sulphate occasions a sensible precipitate in a solution containing 
ttVt °^ baryra, or of any of its soluble salts.^ 

6. Decomposition. — The mode by charcoal has been already 
mentioned. 

fa.) JVot decon^oted by any acid or alkali.\] 
b.) Readily by double elective attraction, with carbonate of po- 
tassa, or of soda, or ammonia, IT after long continued boiling. 

(c.) BtU much mors readily, by ignition with the carbonate of an 
oZfeiit.— Mix pure, decrepitated and pulverized sulphate of baryta, 
with twice its we^t of dry, pure carbonate of fixed alkali, and ex- 
pose them m a crucible to a violent heat. A double decompositioD 



* Euily iboim by adding sulphuric acid to (olutlan of baryta, or any of i[« Mdubls 
mIU; the precipitate will be rcijlsaolved by more ■ulphuric add, and then dirown 
down fay water, and thuR It may be allemalely ndinolved and precipitated by acid 

4 Fint obserTed, la the variety called Bologna slone, by an Ilaliaa sboemaker,' 
named Vincenzo CBaciaroIo. This dibd Ibuod a Bologna atona at the foot or mount 
Patemo, and its farlghtoen and eravl^ made him suspect that It contained sUvcr. 
Having heated It to extract the uTver, he oboervad that it was aflerwardi tumiooua 
in the dark, and on repeating the experiment, it constantly aucceeiled. It is evident 
that by the calcination, it must be coavertnl, at leut in pari, into sulphuret. Prof. 
Olmsted inlbrnia me, (hat a granular aulphate of baryta fiom North Carolina, (Crow 
dei^a mountain,) when heated, phosphoreaces with a clear white tight 

t Henry, 10th Ed. Vol. I, p. 904. J Thfcnard, III. 171. 

11 Fourcroy asscrti, (III, 32,) that the phoapboric and boraclc acids, decompose it 
by ignition. 

n After btutjng tor twohonre, about one fourth of it will be found to be decompmed, 
and the result will be carbonate of baryta, sulphate ef the alkali, and undecompoied 
nilphate of baiyU. 

42 



OMzcdoyGoOgle 



330 SALTS-SULPBATtS. 

nsuhs, and carbonate of baryta and sulphate of alkali remaJD mixed 
in the crucible ; wash out the soluble sulphate with water, dissolve 
the carbcwate of baryta in muriMic acid ; decompose it by the car- 
bonate of an alkali, and thus, after strong ignition, especially in con- 
tact with charcoal powder, the pure earth will be obtained. 

(d.) J^atim canonatK of baryta distolvet in nUphuric acid, uiti 
a terytlow and scarcely perceptible efferteicemx. 

7. Uses. 

{a.) To afford baryta by its decomposition, and for the prepara- 
tiw of a phoqifaorescent substance. 

(i.) It has been used in the munu/octure ofporcelainj particulaTly 
by the late Mr. Wedgwood.* 

(c.) The utificial sulphate, under the name of permanent white, it 
applied m painting in water colors, and is the most delicate and per- 
manent white known.f The carbonate is employed for the same 
purpose. Either of them may be used with advanUge in labelling 
boldes in a laboratory, where acid vapors are so apt to destroy 
cammon writing ink.| 

^d.) The iiUphate of baryta u the only talt of thi$ earth that it not 
pouonout. — If the carbonate, which is a virulent pason, baa been 
swallowed, diluted sulphuric acid would therefore be an antidote; 
and if any scduble salt of baryta has been taken, a solution of sulphate 
of soda or other alkaline or eiuiby sulphate would be the best remedy.^ 

SUI.FBATE or STBOfrrii, 

1 . DiscoTBRT.— £y Dr. Hope and Mr. Klaproth, about the year 
1793. 

3. Natural History. 

(a.) Exitti natwaliy in considerable abundance ; usually called ce- 
jestme, from a delicate tinge of sky blue, which it frequently has; 
first observed at Strontian, in Scotland ; found at Brislol, England ; 
at Bouvron, France, and at Montmartre, near Paris ; in splendid 
crystals in Sicily; also very beautiful atPut-in-B^, Mackinaw, acid 
Detroit, on the Great Lakes, and at Lockport, N^ Y. 

(i.) Found crystallized, massive, or in veins, "composed of nee- 
dles, or very fine rfaomboidal prisms ;" sometimes foliated, fibrous, or 
granular ; occasionally in sulphur beds. 

* He ennloyed It in whtt wai called the Jasper ware, which, for a long lime, irai 
nada tiy Mr. WedEwooil ■lonn; but the secret having; beeo discovered and wld by 
aUthlen wrvtnt, botli the price and beauly ol Uie vessels were soon much re- 
duced by inrerior artists. — Parka' Ettaj/t, Vol. I,p. SIT. t Parkes. 

t Artifictal lulphate mingled ni[h lampblack, painter's chI and npirila of turpentinf . 
Ibr llsht Cleared bottles, drawers, Ccc. without Ihe lainphtack, for black bodies, tt-c— 

cirs. 

§ Th^nard. Vol, III. 172, nys, " I.e sulfate de baryle 
eomme iiMirt-aux-rala," Thii appears to be a luialake; 
■Uncc actually used for Ihis purpose. 



D„tiidD,GoOglc 



SALI-a-SLPHATES. 331 

(c.) Frequently coDfounded witb sulphate of baiyta, but eaa^ 
distioguished from it, by its sp. gr. which is 3.86 ; it is always betow 
4. and sulphate of baryta always above 4.25 

3, Pkepabatiom. 

(a.) By mitieling ^phitrie add and ttrontiaa teater, when it is 
precipitated in uie iorni of a white and tasteless powder. 

{b.) Or by vaxing arty lolubk form of itrontia, loith any sobAU 
ndphate. 

4. Pbofebtie9. 

(a.) Tastelas and inodoroui ; nearly imaluhle; requiring 3000 
or 4000 parts of cold, or 3840 of boiling water. 

(&.) Dissolved b boiling sulphuric acid, and thrown down agun 
by water ; or in the additional mode named under sulphate of bama, 
4. (<■)«.». 

d. Composition. 

Acid, 42+ earth 58=100.— Wolkuton. 
" 46+ " 54:=100.—Vauqwilin. 
" 43+ " 57=100. — Stromeyer. 

According to Dr. Thomson, it is composed of I {HVportion of 
BtTontia 52, and one of acid 40=92 for its eqinvalent, and this would 
require this salt to conust of 43.47 acid, and 56.53 base. 

6, Decomposition. 

(a.) JVo add deeomposa it,* nor does air afiect iL At a high 
temperature it melts. 

(i.) JVo bate except baryta am leparate its add ; but carbonates of 
the fixed alkalies decompose it whh the aid of heat. 

(c.) Decompoted by ignition toith charcoal, in the same manner 
as sulphate of oaryta is. It has not been applied to any use.-|- 
sulfhate of magnesia. 

1. Name and Preparation. 

(a.) That of the shops, called Epsom Salti, from a mineral 
sprmg at Epsom, in Surrey, (Eng.) where, mixed with some sulphato 
of soda, it was first obtained by Dr. Grew, A. D. 1675. But Dr. 
Black first distinguished it from Glauber's salt, with wluch it had, till 
bis time, been confounded. 

[b) Formed, by ditiolving the carbonate of magnetia, or calcined 
m^neuB, in ivipfmric add, somewhat diluted ; it is then evaporated 
and crystellized. 

(c.) Strong sulphuric add and caldned magnena, produce great 
heat, and sometimes light ; but this acid evo&es no heat with the 
carbonate, because the gas carries it away. 



Foqrcroy, Vol. Ill, p. 48. 

t Except Id pyroUchny, for preparing ibe nitrate of itrontia mi Inp^ienl at rti 
firt.~J. T, 



DK;,lz=..,C00g[e 



33a SALTS-SULPHATES. 

3. Pboputtkb. 

(a.) CryiiaU four tided prinu, with quadrangular pyramid^ 
having dihedral summits.* 

The prismatic form, according to Mr. Brooke, is a right rbom- 
boidal prism, of 90° 30, and 89° 30. 

(b.) The Epsom salt of the shops is in the fonn of confused needle 
like ciystals. 

(c.) When pare, unchanged in the air; but sometimes deliquea* 
cent, from mixture with the munate. 

{d.) Svffert a^wtnu funon at low ndnat ; and loses about half 
its weight, but is not voUtilized, except a little of the acid. 

(e.) SoltdiUat 60°, in \ •part of viater, in J of its weight at 312°, 
|he water is expanded \. 

(f.) Solution precipitated by earbonate* ofpotaata and toda, (see 
those articles.) Equal weights of the salts, in equal weights of boil- 
ing hot water ; or, crystallized sulphate 4 parts, carbonate of potassa 
3 parts, in solution ; 100 grains dry sulphate give about 71 carbonate 
of raagne^a, or 33. pure earth. 

{g.) The carbonate is, in this case, preferable to the bi-orbooate 
of an alkali, because abundance of carlxHuc acid suspends the mag- 
nesia ; heat would however, eventually throw down a preci[utate. 

(A.) Carbonate of ammonia does not precipitate the eanb, unless 
heat ia applied. 

ft.) Barytic, Hroniitic, and litne water throie dmen a mixed pre- 
dpttate of carbccate of magnesia and a sulphate of the other earth. 

Q'.) Deeompoted by charcoal at ignition; producing a sulphuret, 
which is, however, feeble in its propertieB. 

!k.) At a high heat completely fusible, but without dectMnpoaition. 
I.) Taste bitter, but less disgusting than diat of sulphate of soda. 
m.) An excellent cathartic; dose, 6 or 8 drachms, dissolved in 
water; and, by many, preferred to Glauber's salts. 

3. Composition. — I proportion of magnesia 20 33.04 

1 " sulphuric acid, 40 66.96 

its equivalent number, 60 100.00 

The cn-stals contun, 

Magnesia, 16. or 1 propor. 20 
Acid, 32.57 or 1 " 40 

Water, 61.43 or 7 " 63 

100.00 123 the equivalent for the 

crystals. 

* For some varie(Jeiorth« cryBliil>,we Henry, Val. I, p. 621. 



J cy Google 



BALTS— SULPHATES. S33 

(a.) Withpan omBUinia, a part of the earth is pnc^itated ; by 
eraporatiaa a triple salt, called the umnmiaco-iDagDesiaii sulphate, 
is c^tained, COTisisting of 

Sulphate of magne^a, 1 proportion 60 

Sulphate of ammonia, 1 " 57 

Water, 7 " 63 

180 its equTsIent number. 

(o.) A compoWTuJ ndphate of magnena and low is obtained, by 
evaporating the bittern of sea water ; it cryEtallizes in transparent 
rhombs, and CMisists, according to Dr. Murray's analysis, of sut 
phate of magnesia 32, sulphate of soda 39, asd water 29 ; and its 
proportions are very nearly those of 1 equivalent of sulphate of mag- 
nesia 60, 1 of sulphate of soda 72, and 6 of water, 54=186 for ita 
equivalent number. It is a cathartic, jiot disagreeable to the taste, 
and is sold at Lymington, England.* 

(c.) A sulphate of potassa and magnesiaf is obtained, when 1 
equivalent of sulphate of magnesia and 1 of sulphate of potaasa aro 
mixed ; they crystaUize with 6 of water, and there is a double sah 
of 1 equivalent of sulphate of magnesia, and 1 of sulphate of ammo- 
nia, wiUi 8 of water, which is obtained by spt^taoeous evaporation 
(^ the mixed solutions. 

4. OntQiN OF Sulphate or Maonksia. 

(a.) Found almndantly m sea water, and obtained from the bit- 
tern, after the evaporation for crystallizing common salt ; it is boiled 
down, imlil, on cooling, in clear and cold weather, it afibrda the sul- 
phate of magnesia, in acicular crystals, in the proportion of i or 6 
parts to 100 of common salt, obtamed from the same water ; or sul- 
phate of iron is added, to decompose the muriate of magnesia, and 
thus increase the quantity of sulpbate.| 

(b.) Maniifactitred from magneaian minerals, especially the mag- 
nesite ; 1.500,000 lbs. are made annually in BaldmOTe, from a mag- 
neaite found near Chester, Penn.& 

(c.) Found native and crytiailized, in remarkable quantity, in a 
great cave, at Corydon, Indiana ; also in many other limestone cav- 
erns, in Kentucky, Virginia, and Tennessee, &c. 

(d.) Effloresces occasionally on brick walls. 

(e.) Formed by the decomposition of rocks, which contain mag- 
nesia, and sutphuret of iron ; the latter a^rds the sulphuric add, 
which combines with the magnesia, and effloresces, and is extracted 
by a process, for which see Thenard, 5th Ed. Vol. Ill, p. 169. 

■ Mnmiy, Slh Ed. Vol. IT, p. 94, lod Edinbargb Truu. 

t SeePhil. Tru».182a, p.455,slM)Henrr, lOthEd. Vol.I. p. 636. 

t See muriate or iiiaB:neM&. 

i Am. Jour. Vol XIV, p. 10. See alio Vol. IT, p. 22. 



OMzcdoyGoOglc 



334 SALTS-SULPHATES. 

(/.) ^Ito by caldnijig the masnesian limestones; treatmg them 
with muriatic acid to disaolre the lime, and then with sulphuric acid, 
or sulphate of iron, to form the sulphate of magne^a.* 

SULPHATE OF ALCBflMA, AND ALUM. 

Common alum. 

1. Preparation. — Alieayt prepared in the large %oay; rartiy 
by the chemist, unless in anoZyni. 

2. Properties. 

(a.) Its properties are always shown by the alum of commerce, 
which is a triple salt, and not mere sulphate of alumina, which has 
characters entirety difierent. 

(i.) Crystals formed from a hat concentrated solution, JUiered ; 
a frame of sticks or some hairs or strings or wires are often suspended 
in it, for the crystals to adhere to ; ihey form a beautiful group, and 
are handsomely exhibited in a bottle. 

(c. ) Aqueous Jitsion and subsequent desiccation by heat, on an igm'ted 
iron ; the product WHS formerly called o/umen utfum ; there is a par- 
tial expulsion of the acid — so that the solution of the desi ccated ahim 
does not easily redden blue vegetable colors.f By a very violent 
heat, most of the acid is expelled. The solution of the crystals red- 
dens litmus liquor decidedly, cabbage liquor slightly, " but blue tinc- 
tures, from the petals of plants, are generally turned Inr it green. "{ 

[d.) Air has generally no action — sometimes produces a slight 
efflorescence. 

(e.) Taste, sweetish, add, and astringent; rather ag-reea6le to 
most persons. — Speci6c gravity 1.71. 

{f) fValer 6 parts at 6(P dissolves I oi ihe sail; at SIS'^* 1 part 
of water dissolves three fourths of its weight. 

(g-.) Pyrophorus. — Take 3 parts of alum and 1 of flour or brown 
«]gar, heat the mixture, and stir it constantly, in an iron pot or ladle, 
till it has ceased to swell, and has become dry ; powder the mixture 
finely, and introduce it into a vial coated with clay ; set this in a 
sand heat, and continue the heat till gas ceases to be inflamed, by 
bring^g a lighted paper to the mouth ; we are usually directed to in- 
troduce a small tube, through a perforated cork, into the vial's mouth ; 
when the operauon is over this may be removed and a cork substibited. 

(A.) This pyrophorvs fires in the air; more vividly, in ajar of 
oxygen gas ; it fires also in chlorine and nitric oxide gas. 



■ id. and Ann. de Cbim. el de Phyi. T. VI, p. 86, tuA Gray'* Op. Chem. 

t It i« facetted llut (ha effect of alum on blue cclnri, may be oninc id i feeble 
affiidty between die add and Ihe earth. Mid of coatae la an attnetiMi between tfae 
acid and the eok>rinK matter, rather than to an excen of uid. 

t Quarterly Jour. XVIII, S98. 



OMzcdoyGoOglc 



SALTS-SULPHATES. S3g 

The foregoing proceu for pyrophorus, which is the utual one, is of 
rather uncertain swxas, and the theoretical reasoning formerly given 
respecting it being imperfect, I do not repeat it herej but proceed lo 
State a better process, furnished me by Dr. Hare, and one which 
rarely fails to succeed. 

Take lampblack 3 parts, calcined alum 4, pearl ashes 8, mix them 
Aorovghly, and heat them for one hour, in a coated iron tube, to a 
bright cheny red, or full red, but not to a white heat. Black's fur- 
nace, filled with charcoal thoroughly ignited, the fiues being then 
shut, and when the fuel is half burnt down, again filled, and allow- 
ed to bum quietly out, with the flues still cloesd, or nearly so, will 
^ve a good pyrophorus. The tube must not be opened until it is 
cold, and then very cautiously. The pyrophorus may be jarred otit, 
by inclbing the tube, and gently striking it with a hammer. If good, 
it fires on falling out, especially if the air is damp, or if breathed upon ; 
caution should be observed lest the little esplosions injure the eyes. 
If a ramrod be introduced to detach the pyrophorus, the operator 
should be on his guard, as a violent explosion sometimes happens, 
discharpng the whole contents at once, with a loud report.* This 
pyrophorus fires brilliantly, if a large stream of oxygen gas be direct- 
ed upon it from a gazometer, or if it be poured into oxygen, or 
chlorine or nitric oxide gas. It fires also, if thrown upon water or 
filming nitrous acid. There can he litde doubt that sulphuret of po- 
tassiujn must be fcnmed in this process, and that to potassium, ta 
some state or other, the principal phenomena must be attributed. 

it.) ^U the alkalies and soluble alkaline earths decompose this salt, 
if ammonia enter into its constitution, it is perceived by the odor, 
when either of the other alkaline bodies is added and heat applied, 
and by the cloud formed with the fuming acids. 

(i.) All the ai&alies throw down the alumina; potassa and soda 
redissolve it, if added in excess, and yield it up again if detached by 
an acid. 

(A.) Ammonia prec^ates the earth mihout redissolving it, or 
oolv very slightly, and heat would throw down even this little. 

(l.) The soMle alkaline earths throw down a mixed precipitate, 
of alumina and the eartbs, combined with the sulphuric acid. 

(m.) Baryta and strontia, are proper for the discovery of potassa; 
if present, it would remain in soluUon, and could be detected by 
muriate of platinum. 

(n.) The carbonates of alkalies decompose this salt, with a slight 
efiervescence at first, and throw down a carbonated earth. 

(o.) Crystals of alum are usually octahedral; 

* See Am. Jour, of Science, Vol. X, p. 866, and tfae Nine thing bu oflen occur- 



OMzcdoyGoOgle 



336 SALTS— SULPHATES. 

(p.) But they baxme ctibical, hy letling a solutkn of <MMXunoii ahim 
etsnd for some dnie upon either ammina or potassa; still, mth a great 
excess of potassa, alum does not ciystallize. 

(9.) Satwate alum, with alumina, by boiling a solution of conunoa 
alum upon it ; U becomet a taatelat insolvhle powder. 

(r.) Digeit luUwai dayi tn nUphuric acid; they dissolve miiy 
partially, and scarcely saturate the acid ; dissolve newlj pr^Mred 
alumina (added in excess) in sulphuric acid, and a neutral sa^Aiate 
is formed, which crystallizes in thin flakes, and becomes slum by 
addidg potassa or its sul|^ate. 

3. CoXFOaiTlON AND TAKIETIE9. 

(a.) The most common variety of alum is that which contains po- 
tusa, but there has been considerable divernty in the stalamenls 
made of its constitution : the following is the average of six analyses.* 
Sulphuric acid, 33.22 ; aluminous earth, 11.07; potassa, 9.88; water, 
46.92=100. 

(&.) Accordbg to Mr. R. Phillips, alum consists of 1 proportioii of 
bi-sulpbate of potassa, 128; 2of sulphate of alumina, (67 x 2) =134j 
36 of water, (9 x 26) =*225=487,+ its equivalent number. 

Dr. Thomson supposes alum to be composed of 1 proportion of 
sulphate of potassa, 88; 3 of sulphate of alumina,! (68X3) 174; 
36 of water, 226=487. 

Tbe difference between these two views is, that in the former the 

auivalent of alumina is taken at 27, and in the latter at 18; and 
ding 40 in each case for the sulphuric acid, we have 67 and 6S 
lor the equivalent of sulphate of alumina, of which 2 proporDous tre 
taken in Mr. Phillips' statement, and 2 in that of Dr. Thomson. 

(c.) Alum wiih iaiit of ammonia,^ consists of 1 proportioa of sul- 
phate of ammonia, 67 ; 3 of sulphate of alumina, 68 X 3 => 1 74 ; 24 of 
vater, 9X24=216; and of the acid, 26.979 are united to 11.906 of 
the earth, and 9.063 are united to 3.896 of ammonia. 

(d.) Alum with bam of toda.\\ — Its composition is stated asbrii^ 
water, 61.31; acid, 32.14; earth, 10.; soda, 6.32: or, 2propor- 
(ions of sulphate of alumma, 1 of bi-sulphate of soda, 28 of water. 
A nadve soda alum is found in tbe isle of Milo, Greece, and ia 
South America. IT 



dtte (hem to definite proportlans, and (he equivalent of aluioina is taken at 2T, 

t Tbe equivalent or alumina beiDg takeD at 18. The diemical equivalent of al"' 
mina is do( yet aacertained with certainty, but Mr. Murray remarks, (IT. 183,) that 
fiom the unalyaia of aalts and miaerals containiDg alumlos, il U more probable tb^ 
18 ij the true number. 

i According to Rifl^ult, Ann. de Chim. et do Fhya. IX, 106. 
Quarterly Jour. Vill. 386, and XIII. 216. I "have prepared a llthia alum, in 
la^e quantities, from the Slerllni; apodumene, in fblloning Berzelius' proeau ^ 
extracting lilhla. It is deliquescent, hut in other rcniecbi retemblea tbe potiv* 
alum.-^. T. ^1 Am. Jour. Vol. XVI. p. 203. 



OMzcdoyGoOgle 



SALTS— SULPHITES. 337 

(£■) Magnesia also appears to form a variety of alum, but it has 
not been applied to use. 

{f.) For a Dotice of o neutral tvlphate of alumina, and for one of a 
sub-sulphate of alumina and potassa, &«:. see Henry, Vol. I, p. 634, 
lOth ed.— Add. de Chim. et de Phys. VI, 201 and XVI, 355, 
and Dr. Thomaon's First Principles, I, 313. 

SULPHITES OF ALKALIES AND EARTHS. 

General characters. 

1 . Taste and smell like that of burning sulphur. 

2. Heat expels sulphurous acid and water, and fuially sulphur, 
which, when inflamed, n urns violently, and a sulphate remains.* 

3. Solution sbwiy absorbs oxygen from the air and becomes sul- 
phate. 

4. Chlorine and nitric acids convert the sulphites into sulphates ; 
and nitric acid gives out red fumes. Sulphunc and muriatic acids 
expel the sulphurous acid with efiervescence. 

5. The sulphites are not precipitated by solution of baryta ot 
strontia, or by any of their salts. 

6. They are formed by passing a stream of sulphurous acid gas 
throu^ the base, dissolved or suspended in water. 

7. The alkaline sulphites are most soluble and crystallizahle. 

8. A neutral sulphite, when its acid is oxygenized, always fonns a. 
neutral sulphate. 

SULPHITE OF LIME. 

1. Besides the general method, already mendoned, this salt may 
be formed from the carbonate. 

2. Insoluble at first, but is dissolved by continuing to pass sulphur- 
ous acid through it. 

3. CrystaUizes in six sided prisms, acuminated by six planes. 

4. Requires 800 parts of water for solution, unless there be an 
excess of acid. 

5. Proportions, lime 28, sulphurous acid 32, by theory.— Brajufe. 

StTLFHITE or BABVTA. 

1. It may be formed by passing sulphim>us acid over carbonate of 
baryta. 

2. A white powder, little soluble, becomes more so by passing 
sulphurous acid gas in excess through the powder. 

3. Compoiition, — Baryta 76, acid 40; by theory, one proportion 
of each. 



>, wbacb ii entiralj exluUed. 



DK;,lz=..,C00g[e 



SALTS— SULPHITES. 



aOLPHITC or STHOHTll. 



This salt is most eaaly formed, bv mingling an alkoliiie eulpliite 
with a solution of the earth in an acid, when there wilt be a preclpil- 
ate of the sulphite of strontia, which is insoluble. 

SULPHITE OF MAONESIA. 

1. Formed also by diffiMUig the carbonate in water, and pas^g 
sulphurous acid gas through it. 

3. Insoluble tul there is an excess of the acid ; ^ves crystals which 
ue flattened tetrahsdra. 

3. Requires 30 parts of cold water for solution. 

4. Taste sweetish and earthy. 

StlLVHITB OF ALUMINA. 

' 1. A white soft insoluble jpowder. 
3. Sohibla >□ an excess of acid. 

SITLPHITE OF POTASS A. 

1. Formed with ease, from a saturated solutimi of the cartMUiate. 
3. CiTStals, long rhomboidal plates or divergent needles. 

3. Soluble in water, 1 pan at 60°, in less at 313°. 

4. Compositioo, 43.5 acid, 54.5 potassa, 3 water; (Thonuit) by 
theory, 1 potassa, 48; 1 acid, 33=80, its ei^uivalent. 

(. Slightly effloresces in air, and becomes sulphate; decrepitatss. 
6. Decomposed by baryta and Ume. 

SULPHITE OF SODA. 

I. Ciystals, tetrahedral prisms, with dihedral summits. 

3. Dissolves m 4 parts of cold water, in less than 1 at 312°. 

3. Effloresces ; sufiers aqueous fusion, and is decomposed at last 
by heat. 

4. Compositioo, soda 1 proportion 32, acid 33, water 9=103; 
=173 for the equivalent. 

5. Potash decomposes it, attracting its base. 

so LP HITS OF AMHOMA. 

1. Crystals, six sided prisms, terminated by pyramids with the 
same number of sides, or rhomboidal prisms with trihedral summiis. 

2. Soluble in 1 part of cold water, and in less at 213°. 

3. Deliquesces, and becomes converted into a dry sulphate. 

4. Fused and volatilised by heat. 

5. Composition, 17 ammonia, 33 acid, for tlie anhydrous salt, 
giving 49 for its equivalent ; and when cryslalUzed, 2 equivalents 
of the salt,=98+l of water, 0=107 by theory .^Brnnrfe. 



OMzcdoyGoOgle 



HVro-SULPHtJKOUS ACID. 939 

HYPO-SULPHVUC ACID. 
UT¥(VBI7LPil ATGB . 

Remarks, — ^In the present advanced state of chemistiy, the most 
serious inconvenience encountered by the student) is found in the great 
extent and vatie^ of deuils. In a concise elementary work, it is im- 
pos^ble to present them all, and there seems to be no better course 
wan to omit, or to notice slightly the leKst important, and to enlarge 
iipoD those of the opposite character, giving at the same time, sufficient 
references to original sources of informad<Hi. 

Were it not that it is desirable to preserve the chemical history of 
bocUes unbroken, and particularly to display the extent and preciaion 
of definite And multiple proportions, I should hatdly have lliought it 
beat to say any thbg of the preceding sulphites or of the acids and 
their compounds which stand at the bead of these remarks. 

BTPO-BUI.PHURODS ACID. 

1, Compoiition. — 1 proportion of oxygen, 8, and 1 of sulphur, ^ 
^40, for Its eqiiivaleDt. 

3. Preparation. — IMfficult to obtain and preserve in an isolated 
state. It is done, 

(a.) By decomposing the dihite solution of hypo-sulphite of stron- 
tia, by dUute sulphuric acid ; the earth is precipitated and the acid 
Iterated. 

(i.) By digesting sulphur in a solution of any sulphite, when an ad- 
didonal proportion of sulphur is dissolved, and hypo-sulphurous add 
formed ; or by decomposing hydro-sulphuret of lime* or stronda, by a 
stream of sulphurous acid gas, when there is an exchange of one pn^ 
portion of the oxygen of the sulphurous acid for one proportiiMi of 
the sulphur of the hydro-sulphuret, water being formed, and thus two 
proportioDS of sulphur remain in union with one of oxygen. 

3. Properlies. — A transparent, colorless, inodorous aad ; decom- 
posed spontaneously, sulphur precipitated, and sulphurous acid re- 
mains. 

BTPO-SDLPHITBS, OR SIILPHinueTTED SULPBITBB. 

1. Preparation. 

(a.) I^e Iqrpo-sulphites of the alkalies and alkaHne earths are best 
obtained by pasung a stream of sulphurous acid gas through a lixi- 
vium ofltuMeoodies that has been boiled with sulphur; thesmphurous 
acid is converted into bypo-sulpburous, and the excess of sulpnur pre- 
cipitated. 

ffr.) By boiting a sulphite with sulphur. 
c.) By double decomposition ; an alkaline hypt^sulpbite being 
nuxed with an acid solution of some other base. 

* 8m p. S47. 



DK;,lz=..,C00g[e 



340 HYPO-SttLPHUItlC ACID. 

2. Propertia. 

(a.) Generally soluble in water, and have a biiter taste ; preciiH- 
tate nitrate of silver and mercury black, in the fonn of sulphurels of 
those metala ; salts of lead and baryU are thrown down as white in- 
soluble hypo-sulphites of those bases. 

(6.) Muriate of silver, recently precipitated, is dissolved by the 
hypo-sulphites, and especially by that of soda, and a fluid is formed 
sweeter than honey, and entirely void of metallic taste. The hypo- 
sulphite of ammonia forms with muriate of silver, a white salt of which 
1 grain imparts a perceptible sweetness to 32,000 grains of water. * 

HtPO-aULPHCRIC ACID. 

I. Ducovay. — In 1819, by Welter and Gay-Lussac.f 

3. Preparation. — Black oxide of manganese in line powder, is 
suspended in water, and a stream of sulphurous acid gas passed 
through ; two acids are formed by the oxygen of the manganese ; 
the sulphuric and hypo-sulphuric, and both unite with the base, fomi- 
ing sulphate and hypo-sulphate of manganese ; both are decomposed 
by adding solution of baryta slightly in excess, which precipitates 
manganese and sulphate of baryta, and leaves hypo-sulphate of baryta 
in solution. Carbonic acid gas is then passed through, to remove 
any excess of baryta ; the solution is boiled to expel the caibooK 
acid, and by evaporation, hypo-sulpbate of baryta is obtained in crys- 
lals. To a soluQon of these crystals, sufficient sulphuric acid is caa- 
tiously added to saturate the baryta, which is precipitated da the fbnn 
of sulphate, and the hypo-sulphurous acid remains in solution. 

3. Prf^ertiet. 

(a.) A colorless, inodorous acid, changes the test fluids ; concen- 
trated by heat, or under the receiver of the air pump, its sp. gr. is 
1.347, but if attempted to be carried farther, especially by heat, it is 
decomposed and converted into sulphurous and sulphuric acids. 

(6.) Suffers no change from the air or from nitric acid ; it dis- 
solves zinc like the stronger acids, and forms hypo-sulphate of ^oc, 
while hydrogen gas is evolved. 

(c.) It forms soluble salts with baryta, strontia, lime, lead, and 
silver, which completely distinguishes it from sulphuric acid. 

4. Composition. — Ascertained by decomposing the hypo-sulphate 
of baryta by heat, and the proportion of sulphur appears to be 1=32, 
and of oxygen, 5=40=72, for its equivalent. 

HYPO-SULP HATES. 

1. proration. — Formed by direct combination with bases. 

' For mumerou* >ddiliaaal particularx, see Ann. de Chim. Vol. LXXXV ; Edb. 
Phllos. Jour. Jm. lBi9, Vol. 1. 8, aad S9«, and Ure'a Diet. 2d Ed. p VI. 
t Ann. de Chim. ei de Phya. Vol. X. 



OMzcdoyGoOgle 



SULPHURETTED HYDROGEN. 341 

2. Propertiet. 

(a.) All soluble ; dectxnposed by a moderate heat, sulpbimxu 
acid gas being exhaled and sulphates remaining. 

(6.) StroDg sulphuric acid decomposes the acid of the hypo-sul- 
phates, at the instant when it is decomposieg the saJts which contfUD 
it ; a weak acid, applied cold, separates the hypo-sulphuric acid with^ 
out decomposition. 

(c.) Not changed by the air, or only slightly absorb oxygen. 
The hypo-sulphate of baryta crystallizes in square prisms of pecul- 
iar brilliancy ; that of potassa in a cylindroida] form ; that of lime in 
hexagonal, and that of strontia in very small hexahedral lamine. 
Compontion of the acids ofmlphur. 
Sulphur. Oxygen. 
Hypo-sulphurous acid, - - 16 -H 8 1 and 1 propor. 
Sulphurous acid, - - - 16 + 16 1 and 2 " 

Sulphuric acid, - - - 16 + 24 I and 3 " 

Hypo-sulphuric acid, - - 32 -f- 40 2 and 5 " 

Thus these compounds beaudfuUy illustrate the laws of definite 
and multiple proporuons. 

COMPOUNDS rORMED BETWEEN SDLFHTTB, HTDBOGEN, AND THE AL- 
KALIES AND EARTHS. 
SULFBU BETTED HIDBOQEN. 

1. NoH£NCLATtTRC. — The termination tiret is appropriated to 
combinatitms of simple combustible, non-metallic* bodies, with each 
Other and with the metals, alkalies, and earths. Thus, in the ease 
of sulphur and phosphorus, we have sulphuret of phosphorus, or 
phosphuret of sulphur, sulphuret or phosphuret of lime, and of calci- 
um, of potassa, and of potassium, of iron, &£. To denote diflerent 
proportions of the principles, terms are derived either from some 
sensible property, usually the color ; e. g. we have a black and red 
sulphuret of mercury, yellow and red sulphuret of arsenic, &c. ; or 
it is npw more usual to prefix the same terms that are applied to the 
oxides, as proto-sulphuret, deuto- sulphuret, &c. implying one or two 
proportions of sulphur, &tc. 

Where the compound is gaseous, it is usual to add ted to the ter- 
mination wet ; as sulphuretted hydrogen and phosphuretted hydro- ' 
gen, instead of sulphuret and phosphuret of hydrogen. 

2. HisTOBX. — Known to Rouelle, but first investigated by Scheele, 
A. D. 1777 ; afterwards by many distinguished chemists. 

3. Pbocesses. 

(a.) Sy heating mlphur in hydrogen gat, by the solar rays J or 
by subliming sulphur, repeatedly, in nydrogen gas ; or, by passing 
this gas over sulphur heated in a porcelain or coated glass tube. 

* The campound* of mctaltic bodlei with eachitther ire c*tletl alloys. 



D„tiidD,Googlc 



343 flCLPHURBTTED HYDROGEN. 

(6.) Better by the aid ofndphwet of iron, to prepare wbich, min- 
gle floWbn of sulphur and iron filings, equal parts ;* heat them in an 
iroQ pot or skillet, under a chimney, not merely till tha sulphur 
lAelu, which happens almost immediltely, but until an iotimate 
ebemioa] union is indicated, hy incandescence perradiog the entire 
loasa ; it b^ins with a little luminous spot or spots, and gradually ex- 
tends through the whole, while the vessel containing the matenals » 
perhaps not even red ; at this moment, the boilmg and combustion of 
sulphur cease, for it b now detained by its affinity for the iron. 
The sulphuret being pulverized, is fit for use, and will not disappoJat 
the experimenter, f 

(c.) To one part of the sulphuret of iron thus made, add 3 of mu- 
natic acid, with 4 of warm water, and when the gas begins to come 
languidly, a little heat may be applied. 

(d.) Powdered sulphuret of antunony, with 5 or 6 times itfl Weight 
ofrauriatio acid, (sp. gr. about 1.160,) apply the htat of *1unp; 
this process, although strongly recommended, has not suoceeded well 
witti me. 

(e.) Add diluted sulphuric or muriatic acid to almaat an^ alksJiM 
sulphuret, preferably of potassa, but the gas comes too rapidly (o be 
easly managed ; process (c.) 13 the best. 

4. Pbopgrties. 

(a.) Sp. gr. 1.18, air bemg 1 } 100 cub. inch, weigh nearly 36 
gtaiM.J 

(&.) Smdl very offentive, like that of rottet) eggs, or of sulphureous 
mineral waters. 

^e.) When kindled in contact vith air, U bums ^ietltf, wid) s 
*-*-— h white flame, and deposits sulphur on the glass vessel. 
) Mixed with ammon air, it outtu more rapidly. 
I With oxygm, three measures to two of this gas, it deUmaiei, 
producing water and sulphurous acid. 

(f,) Water abiorbi its own volume or, if the gas be pure, even wo 
or mree times its Volume, and then resembles exactly, the native 
■ulphiireous waters. 



* Or nilphar 1 part, inm a. 

t The mere meldog of Iroo Glinn ud sulphur, tnd Btlll more the mem miDKli^E 
of lh<m will not inswer ; fbr, when the add U added, Ihe gu produced will IM 
merely ■ mfxtura of inlphuretted hydrogen, and coDunoo bydrogea gu. The po- 
eembf rubbing roll sulpnur upon a bar of iron heated to wluteaeH, dll liquid <ln9> 
All, glTei alio a true sulphuret which will iflbrd the gas. but the iiuu)ipuli(l» U 
mors troubleiocne, and the product ofiulphuret of Iron laimatl. 

The fblk>wiilg proeanwaiMHnmuulcaled. — Heating the natire yellow pyriui.iii 
a close crucible, tUt 1 pnq;K>rtion of nilphur la expell^ i and a fins proto-iuIphuraE 
Will be left. J. T. 

t KM, KCordiDg to Dr. Thonwn. Dlllerent authors have rtaled its tp. p- i"- 






ci.Kj J, Google 



SDLPHURBTTED HYDROGEN. 343 

(g.) Tkufiuid tamiMha metaUie tolvtioru, aod bright metals; e. g. 
silver, mercury ; also, wbite paint, acetate of lead, muriate of bismuth, 
uitFatQ of silver, he, 

(A.) Write mtk a lolution ^tUver or lead on cards, and expose 
^tn to diis gas; Dr. Henry found that ,%ifj part of this gas, mix- 
ed with common air, or hydrogeo, or carburetted hvdrogen, pro- 
duced a sensible discoloration of white lead, or of oxide ofbiEonuth, 
mixed with water and spread upon a card. 

(t.) Moittm the entire smface ofeardt mth the lolviion, and ex- 
pose them as above, when they will be entirely tamisbed. 

{}.) Aqueout tolution reddetu infusion of moleti or liinau Uquor 
or paper, and in this respect resembles the acids. 

(A.) SiUpkuretted kydrogen beivg mixed with tulphvrout aeid, 
either liquid or gaseous, au^hur is deponted by mutual decomposi- 
tion } if 3 volumes of sulphuretted hydn^en be mixed with 2 of sul- 
phurous acid gas, both being dry, they are endrely condensed into 
sn orange yellow substance, having acid properdes, and conqistiBg, 
according to Dr. Thomson, of 5 [voportirais of aulphur, 4 of oxygen, 
and 3 ofbydrogen.* 

(I.) lAquid tulphureUed hvdrogen dtpontt tulphw, by exposure 
to au-, or even in a bottle, and in uie channels where the ntlf^ureouB 
mineral waters run. Fuming nitrous acid precipitates the sulphur, 
but the colorless acid does not. 

(m.) Faming nitrous add, being poured into a wide mouthed re- 
ceiver, filled with sulphuretted hydrogen, decompotition hament, ipd 
a beautiful Hame ^reads through the interior of the vessel.f 
(n.) Chiorine aeeompoiu thit gas and precipitates the sulphur. 
(«.) f^ertf hostile to life ; if pure, kills almost instandy ) or 
even if mingled with a large proportion of air, it is very noxious. 
Air containing only y,',; killed a bird, ,|, a dog, and yj, a bone.t 
A young rabbit, whose head was in the pure air, and its body ett- 
clcued in a bladder filled with sulphuretted hydrogen, died in 16 or 
30 minutes ; old rabbits hved longer. It is fa^, therefore, when ap- 
plied to the surface of the body. 

(p.) Sulphuretted hydrogen precipitates all the metals, except 
iron, nickel, cobalt, manganese, titanium, and molybdena. 

{q.) Electricity and galvanism ihrour down sulphur, and an equal 
volume of hydrogen gas remains ; sulphuretted hydrogen is partially 



" Ann. PhD. Vol. XII, p. 441. 

A riratlir deeompotUlon !■ supposed by Prof. Dkuben; t» b« the pTfaidpal •eurcc 
of Tokuilc gulphur. See bii lectures on Volcinoi. Am. Jour. Vol. XIII, No. 2. 
f Ann. ofPhll. Vol. VIIJ, p, 228, and Henrr, Vol. I, p. 44», 10th Ed. 
t Thteird, Vol. 1, 7». 



DK;,lz=..,C00g[e 



344 Bl-SULPHURETTED HYDROUEN. 

decoraposed, by being passed through an ignited porcelain tube, or 
over igoited charcoal. — Theaard. 

(r.) Alkalies absorb it readily, and thus it is easily separated from 
common hydrogen. 

(>.) Polatiium amd sodium, heated in thta gas bum briiliatidy ; 
i. e. much heat and light are evolved, and a sulphuret of the metal 
is formed, while as much hydrogen gas is produced as the metal 
would have hberated from water. ' Diluted muriatic acid produces 
from the sulphuret the original quantiy of sulphuretted hydrogen gas. 

5. Composition.— According to Dr. Thomson, it is composed of 
1 volume of the vapor of sulphur = 1 propcntion 1.111, -f- 1 vol. of 
hydn^en gas, 0.069 ; these numbers being almost exactly in the 
ratio of 1 : 16, give the equivalent weight of sulphur very nearly 
the same as that deduced from the composition of sulphuric acid.* 

6. Liquefaction of sulphuretted hydrogen. 

(a.\ Mr. Faraday, by disengaging this gas in a recurved tube, 
seaJea, before tlie materials were brought into contact, the end oppo- 
ute to that in which they were contained being kept cold by a freez- 
ing mixture, succeeded in condensing it into a liquid. 

(&.) It was limpid, colorless, and more fluid than ether ; equally 
fluid at as at 45° Fahr. and its refractive power greater than that 
of water. 

(e.) The tube bebg opened under water, the fluid rushed instant- 
ly into gas, which was sulphuretted hydrogen. The pressure of its 
npor, at 50° of Fahr.f was equal to seventeen atnKK^heres, or 255 
lb. to the square inch. 

Remarks. — Sulphuretted hydrogen gas exists abundantly in the 
sewers and privies of great cities. I have observed, in London, that 
a sudden and heavy rain would force it out in great quantities, taint- 
ing the atmosphere, and tarnished white lead paint. In great cities, 
especially in Paris, it is often fatal to those who clear away the Sllh 
ofihe sewers: the best antidote and remedy is chlorme, especially 
in the fbnn of chloride of hme. 

BI-SULPHIJRETTED HTOSOGEN. 

1. Discovery. — By Scheele originally, and afterwards examined 
by Berlhollet. J 

2. Preparation. — Boil flowers of sulphur with liquid poiassa ; 
pour this reddish brown solution, by litde and Utde, into muriauc acid ; 
veiT little sulphureued hydrogen escapes, and a part of it combines 
wilib more sulphur, and precipitates, of an oily appearance ; or, fill 
one third of a vial with muriatic acid, of the sp. gr. 1.07, and pour 

I PhU. Tram. 1828, p. 192. 



OMzcdoyGoOgle 



HYDRO-SULPHURETS, 345 

in an equal bulk of the above named compound of sulphur and al- 
kali ; the vial being corked and shaken, the peculiar fluid gradually 
sub^des to the bottom, in the form of "a brown, viscid, semi-fluid 
mass." — Hmry. The hydrogenized sulpburet of lime h also used, 
in the same manner, for obtaining this compound. 

3. PmOFERTIEa. 

(a.) Odor like that of putrid egga ; heavier than water ; burns 
with the smell of sulphurous acid. 

(6.) A gentle heat causes sulphuretted hydrogen to exhale, aod 
sulphur only is lefL 

(c.J It unites with alkalies and earths, and jvoduces the sidphu- 
rettea hydro-sulphureta, or by drogu retted sulphurets. 

{d.) If kept in a vial, floaung on water, it exhales sulphuretted by- 
drogeo, whenever the stopper is withdrawn. 

(e.) If placed on the tongue, it gives a pungent bitter taste, exhales 
sulphuretted hydrogen, and leaves sulphur in the mouth. 

4. Composition. — According to Mr. Dalton, 2 proportions of sul- 
phur =32+1 of hydrogen =33. In centesimal proportions,* it con- 
sists of sulphur 96.75, hydrogen 3.35=100. Its combinatioDS with 
alkahes ma presently be considered. 

HTDRO-SULPHURETS.-f- 
COHPOUMDS or SULPHURETTED HTDROGEN AND BASES. 

JtUroductojy Remarki. 

It has been already observed, that sulphuretted hydrogen performs 
the fiuicdons of an acid. It is not sour to the taste, but it reddens 
the infiision of vegetable blue colors, or at least that of litmus or 
radishes ; its most important character, as an acid, is, that it com- 
bines with the alkalies and alkaline earths, neutralizing their alkaline 
properties, and forming crystaltizable compounds, analogous to the 
salts. Some have therefore enrolled sulphuretted hydrogen among 
the acids, but, in a free state, except a feeble efiect upon some of the 
blue test cokirs, its properties are so different irom those of acids, 
that 1 prefer to consider it as merely a compound combustible gas, 
adding a nodce of those properties that assimilate it to acids.| 

1. Preparation of hydro rulphurets, — Formed, by ptunng $ul- 
phuretttd hydrogen gas through the bate, suspended or dissolved in 
water, in Woulle's or other convenient apparatus. 

■ Henry, VtA. I, p. 4JT. 

I Called ,by aoma lulhora hydro-iulpbitci, fau) it would aeem, unhippilj; u ihe 
leinier it In dinger of confbundiPK them nIA the sulphatni : (he old nune ippem 
to be uneiceptioiuble. See Dr. Turner's Chemistry, 2d ed. p. (!0B. 

t It has been called the hydro- tbiomc, and the hydro-iulphurlc uld ; neither 
name hu obtiined much curienry, and the latter coaJbundj thli body nlth liie coin> 
mon lulphuric acid. 

44 



OMzcdoyGoOgle 



346 HYDRO-SULPHDRGTS. 

2. General ntoPERTiss. 

(a.) Solvble in wrier, recrat solution ct^less, by exposure to ibe 
ur become greenish or yellowidi, and depoat sulphur oo ibe stJa 
of the vessel. 

(b.) If the bottle in which they are kept contains lead, it is redu- 
cea, and coats the interior with a metallic lining, probably a sulphuret. 

(c.) By long exposure to the air, and even by long keeping, tliey 
pass to the state of sulphites, and ultimately to that of uitpfaates, whicli 
are sometimes precipitated, and someumes r«nain, in part or in whole, 
in solution. 

(d.) Addi libtt-tUe ivlphuretted hydrogen, but dtt not precipitate 
sulphur ; 

fe.) Except* the nitric acid, which combines with the hydrogen 
to lorm water, and thus liberate sulphur ; 

(/.) Except also when the hydro-sulphurets have been partially 
decomposed by careless keeMng, when uiey throw down sulphur. 

(^.) Precipitate all metallic soluiioju, and also ^umina and idr- 
coma, but no other earths. 

(h.) Generally crystalliiable. 

(t.) Take up an additional dose of sulphur, by digestion, upon it, 
but do not su^r it to be agam precipitated by a stream of sulphuret- 
ted hydn^en. 

(j.) Alter exposure, for some dme, to the air, exhale sulphurous 
acid gas along with sulphuretted Wdn^en, and precipitate sulphur. 

iki) Absorb oxygen, and therelore used in eudiometiy. 
/.) If there is no more sulphuretted hydrogen than is necessary to 
saturate the base, they are inodorous ; but they usually have the odw 
of sulphuretted hydrogen, because it not only saturates the base, but 
combmes with the water of the solution, which after the supei^uout 
gas is expelled, by heat, will no longer have any odor. 

(ffl.) The hydro-sulphurets are decomposed by heat, and the bue 
remains ; aounonia excepted, which is euialed. 

(».) It is said that suibhuretted hydrogen combines with alkalies, 
in a double propordon, forming bi-bydro-sulphurets. 

HYBBO-BDLPHnRET OF POTASSA. 

1. Crystallizes in large transparent crystals, similar to diose of sul- 
phate of soda ; four maed prisms acuminated by four planes, or six 
sided prisms with six planes, at the ends. 

2. Taste alkaline and bitter, inodorous when dry, hut becomes 
odorant by moisture; is deliquescent. 

3. Fwms a syrupy liquor, which imparts a green color to bodies 
in contact with it. 

4. Dissdves, not only in water b<it in alcohol, producing cold. 

' Cblarine produce! the lame effect by wiiiug Ihe bjrdrogen. 



OMzcdoyGoOglc 



HVDRO-SITLPHURETS. 347 

HTDRO-SDLPBURET or SODA. 

Ciyatals formed wilh more difficulty than the preceding ; trans- 
parent, quadrilateral prisms, acumbated by four planes, bearing a 
close resemblance to the hydro-sulphuret of potassa.* 

HTDEO-SCLPHUHET OF AMMONIA. 

1 - The two gases mixed over mercury, or in a bottle, or other- 
wise, combine ; in equal volumes, they are almost completely con- 
densed into an odorous cloud, which forms a soft white crystalline 
deposit on the inade of the vessel, and if it is kept cold by ice, acic- 
ular crystals will be formed. 

2. The liquid solution is eadly formed, but does not crystallize. 

3. It is an excellent test, in examining metalUc solutions. 

4. Admitted into the Pharmacopeia, as a depressing and nausea- 
ting remedy, in cases of too great action— introduced by Dr. Rolb, 
and lued chiefly b diabetes ;^ dose, 6 or six drops, three or four 
times a day, graduaUy increased, and mitigated, when nausea and 
^ddbess supervene. 

HTDRO-SULPHUBET OF LIME. 

1. Formed, by passbg the gas, either through lime water, or milk 
of lime. 

2. It is formed when sulphur is boiled with lime and water ; but 
there is also another product soon to be described. 

3. I have often seen distinct prisms formed m the solution made 
by boiling lime and sulphur to saturation in water ; I am not aware 
that they have been examined ; if not hydro-sulphuret, may they not 
be hypo-sulpbite of Kme .' 

HTDBO-EULr BURET OE BAATTA. 

1 . Formed, as mentioned in the general characters ; but 1^ far Uie 
best method is to obtam it from the decomposed sulphate, by char- 
coat, as described under sulphate of baryta, and soon to be mention- 
ed again, with particular reference to this subject. 

2. It crystaliiEes, confusedly, b brilliant plates, which must be ' 
dried between fcdds of blottbg paper, and if immediately disserved 
m distiSed water, diey form a cobrless solution. 



mlphita of ilumiu, which (he o(h«r olt woold do, but thb dbtlDcUoa k 
tad, protwblj, before it waj ksowa that there i* ■ triple tod* klxm. 

1 llie phyridu eiD prepare tttli remedy by eibieittng the ^ta, under a cUm- 
Mjr, to the tnalUMT already deacribed under aiilphuretted hydrogea, and )MMiM it 
Eram an oil flaik, or bottle, thronrii the aqna animaniB of the ^bnf, cootateedm ■ 
vlat immenad in edd walm, or Miter, aarrounded by Ice. TUt ramedv Ita* «dU 
cmaidetable repntatloD, and coi^olDed wiOi a diet of animal mnade, la dion|^ to 
have pradneed Ibe tnoat aahilary rewlta. I hare reptatedly pr^MMd it far |Ay- 
ddaoa, and bare alway* beard a bronble leport of Iti tfectt, ^ tmjmiud tniA « 
figorotu ditt. 



D„tiidD,Googlc 



348 SULPHURETTED HYDH0-8ULPHURETS. 

UTDRO-STTLPBUHET OF STRONTIA. 

In every respect as the last, only the dec(Hnpo«lion of the sul- 
phate is not so striking. 

HtDBO-SDLPHDRET OF kUGNESlA. 

1 . Formed by passing the gas through the magnesia suspended io 
water. 

3. It is a feeble and imperfecdy cbaracteiized compound. 



1 HTDRO-8DLPHURETS." 

General Characten. 
1. Formed, by boiling flowers of sulphur with the base, dissolved 
or suspended in water. 

1. Causuc heavy fluids, of a greenish yellow, or brownish color. 

2. Stain the cuticle black, have an acrid taste, and an oflfensire 
smell. 

3. Depotil mhihw when k^t in dote vettelt, and become tacav 
Uansparent, and lighter colorea. 

4. Abiorh oxygen gat, and therefore used in eudiometry. 

5. Sulphuric and muriatic addi throw down lulphur, and etolve 
lulphuretted hydrogen. 

6. Exposed to the air they are slowly changed Into sulphates. 

7. Have a soapy feel, 

8. -Sulphuretted hydrogen, passed through them, precipitates the 
excess of sulphur, and converts them into hydro-sulphurets. 

9. Sulphuretted hydro-sulphurets, are formed also, by digesting 
a hydro-sulphuret upon sulphur, but they do not throw down sulphur 
when sulphuretted hydrogen is passed through them.'l' 

SULPHUaETTED HIDRO-SULPHDRET OF FOTASSA. 

1, Boil sulphur, 1 part, with 3 of the solution of caustic potash, 
of the common strengd.| 

3. Or, decompose the sulphate of potassa, by heating it red hot 
along wiUi i of charcoal, in a crucible : dissolve every ^iog soluble 
in hot water, and filter ; the theory of these facts will be g^ven farther 



* Cftlled alao hydrogeDized, hjdroguretled, lod hydroECDited snlphureli, but tbe 
ntme Id llie text u pieferred, becaUK it expreMes correcuy Iha compoillloa of tt"** 
bodlei. 

t AlkiD, Vol. 3. p. 864. 

t Pearl ube>, water, ud (ulpbur bcriled together, produce hydrogeniied nilpbU' 
retof potaaw of a very vood quality, w that it ii notDeceNary to lue caiutic potubi 
praUbV *•) •o<l* "OUM alio aniwer initaad of caiutlc aodtu 



OMzcdoyGoOglc 



SULPHURETTED HYDRO-SULPHUBETS. 349 

3. The color varies in iDtensity accordmg to the degree of con- 
centratioQ. 

4. The principal use made of this preparation is in eudiometiy ; 
but the compound with lime is moet used, which see. 

SULPHURETTED HTDRO-SU LP BURET OF SODA. 

1. It is almost perfectly identical with the last. 

2. The sulphate may be decomposed by charcoal in the same 
maimer, but the appearances are less striking. 

SULPHURETTED HTDBO-SULP BURET Or AMHONU. 

1 . If liquid ammonia be digested upon sulphur, the action is fee- 
ble and not much sulphur is dissolved. 

3. But ammonia in its nascent state, dissolves sulphur readily. 

3. A preparation of this kind was formerly called Boyle'» Jvnung 
liqtior ; 3* parts slacked lime, 1 muriate of ammonia, 1 flowers of 
sulphur, and half a part of water, are mingled and a e^ntle heat ap- 
plied ; the first drops are watery, and as they become deeper colored, 
the heat is raised till the bottom of the retort becomes shghtly red. 

4. White fumes are abundantly extricated in the more early stages 
of the operation, and must have vent from the receiver. 

5. The 'fumes may be all coUected in a Woulfe's apparatus ; they 
are more abundant and incoercible in proportion as less water la 
added. 

6. The liquor fumes, as soon as the stopper is withdrawn from Uie 
bottle in which it is kept. 

7. The fuming is owing to the ammonia in excess, meeting with 
sulphuretted hydrogen, -{- for when the fuming liquor is digested on sul- 
phur, the ammonia becomes saturated and the fuming ceases. 

SULPHURETTED HTBSO-3ULPHURET OF LIKE. 

1. Boil slacked lime with i| sulphur and 10 parts of water, for 
half an hour or an hour, and shake frequendy during the boiling. 

2. The fluid is of a fine orange yellow, and deposits crystals on 
cooling. 

3. Decomposition of the sulphate by charcoal and heat, succeeds 
but imperfectly. 

4. For the rest, see general properties. 

5. This preparation and the parallel one of potassa are much used 
in eudiometry, and this is rather preferred, because it affi>rds the 
most concentrated solution. 



DK;,lz=..,C00g[c 



360 SULPHUHOTTED HTDHO AND LIQUID SITLPHURETS. 

BUDIOmTCR or DB. HOPE. 

" Thia eudioraeter consists of a graduated glass 
tube, sealed at one end, and at the other fitted, 
faj grinding, into the mouth of a tubulated glass 
botue, so as to be air tight. MaaipuUtion, with 
this instrument, is very simple. The tube b 
filled with gas, the bottle with the liquid which 
is to act upon the gas. The tube being, under 
these circumstances, inserted into the mouth of 
the bottle, by inverting both, the cwitained gas 
is made to paw into the bottle. Agiution is 
next to be resorted to, and time allowed lev 
the absorptioD to be completed. Id the interini, 
the ndiulure is to be oooaaonally opened under 
water, by remoringii ground stopide with which 
it is liitnisbed. The gas abswbed, it conse- 
quently replaced by water. 

" Finally, the stopple must be removed, the 
tube being previously depressed into water, till 
this Uquid IS as higo oo the outside as within. 
The graduation being at the same Ume inspected, 
the deficit produced by the absorptioa of oxygen, is th*w ascertain- 
ed."— i>r. Hare. 

SULPHunETTED HTDBO-SULFHUBET Or BABTTA. 

1. Thi8CompoundisforiDedeitberbyb(Mlingpurebar}na(4 parts-) 
in powder, or m crystals, with water upon sulphur, 1 part, or by de- 
compoaog the subhate of baryu by ignidng it aI<Hig with one sixth 
charcoal powder for half an hour ; then dissolving it in hot water and 
filtering. 

2. This a mixture of sulf^uretted hydro-sulphuret and of hydro- 
sulpburet, which last will crystallize on cooling. 

3. See general characters for the rest. This compound is very 
useful in preparii^ the salts of baryta ; see the muriate and carbo' 
mte. 

Sin.PBUBETTXD BYDBO-SULPH0KET Or STROKTIA. 

The same in every respect as the last, only the decompoailioD of 
the sulphate by charcoal is less striking. 

LIllinD Sin.PBint£TS. 

1 . This name is often given to the hydrogenated sulphurets. 

2. Indeed they seem to consist generaJJr of a solution of sulphur 
m an alkali, combined with more or less of sulphuretted or of bi-sul- 
I^niretted hydrogen. 



OMzcdoyGoOglc 



SULPHURETTED HYDRO^ULPUURFTS. 35f 

3. Accotding lo Proust, a pure liquid sulphuret, without sul^uret- 
ted tnrdrogen, may be formed, by withdrawiog the latter by rod ox- 
ide of iDetcury.* 

BD LP Hints TTJCD BTDSO-SULPTnTBET OT HAOBTESIA. 

By processes similir to those pointed out above, mapiesia pres 
but feeble indicatioiis of combining with sulphur, tac., and is the last 
of the earths that gives any. 

Hemarh. — The elaborate refearcbes of BenhoUet, (I798J for- 
luerly led us to suppose, that when a base is boiled with sufficient 
sulphur, a fluid sulphuret was produced, which decomposed water, 
ana generated sulphuretted hydrt^en, part of which was exhded, 
thus producing the peculiar odor w these preparatioos, and that die 
remunder of this gas combined with the sulphuret, and fwmed what 
was called hydcogenized sulphuret ; and it w«a bought to be a suf- 
ficient proof of the truth of this opinitn, that an acid decomposed the 
preparation, evolving sulphuretted hydrogen and precifatating sulphur 
abundantly, both of whidi facts were supposed to arise from the acid 
seizing the base lo form a salt. 

More recently, we are taught, that bi-salpburetted^hydrogen is geo- 
eraied in these cases, and that (fae excess of sulphur is contained ht 
that mode of combination. But I diink ifais cannot be all tfaat Imp' 
pens i tot tfwre is great varie^ in the quaoti^ of sul}diuretted hydro- 
gen, which acids evolve, and of sulphur which ib^ precipitue btm 
uirae preparations. Sometimes, although Eulphur is abundantly prs- 
dfatated, very little gas makes its escape, and at other times it is 
very abuodant. I am persuaded thai there is f^ten mncb sulphur k 
Bolution, which is simply dissolved by the entire compound, and is 
not mereW combined with the hydrogen in the form of sulphuretted 
or bi-sul{miretlied hydrogen. My experience would lead me to ac- 
cord with tlie ffdlowing opinion of Dr. Ure.-f- 

1. Sulphuretted hydrogen, sulphur and the alkalies have the pro- 
perty of forming very vanable triple combinations. 

2. All these combinaiious contain less sulphuretted hydrc^en than 
the bydro-^ulphurets ; and 

3. The quanti^ of sulphuretted hydrogen is mversely as the std- 
phur they contain, and reciprocally, 

SULPHDRETS. 

I. Sidphttrett of cdktdia and alkaline earths. 

Retaarks. — Until within a few years, it was supposed that the fu- 
sion of dry sulj^ur with tbe fixed alkalies and alkaline earths, piothi- 
ced a true sulphuret of the alkahne body, and it is still by no means 
certain that, uoder particular circumstances, this is not the fact. It is' 
the ojunioQ of Gay Lussac, that a true sulphuret of an oxide is form- 
ed, provided the temperature is kept below igaiti<»i. "A une tem- 

• Aikio'i Diet. Vol. II, p. 863. t Did. Zd Ed. p. T6«. 



OMzcdoyGoOglc 



363 SULPHURETB. 

peratun peu tietiee, qtU n'atleigne janutit la dudeur rouge, ce cotps 
se combine avec les alcalis sans les decomposer, et forme dea sul- 
fures d' oxide." This appears to me so probable, that I sball here 
preserve a iiMice of what were, heretofore, regarded as alkKfioe 
sulphurets. 

1. Farmed hy fiuion of nUphur mthtliebaie, or decomposifioii 
of a sulphate by ignition witH charcoal powder.* 

2. Of a liverf color, if formed with caustic alkalies, or greeniA 
j/eUotc, if with their carbonates. 

3. InodortntM, while dry. 

4. Decomposed by a higher degree of heat thao that by whicii 
they were formed, sulphur being sublimed, and the base left in the 
bonom of the vessel. 

Gbemisti and physicians|; were KCcustomed to use these prepara- 
tions in solution, out they then ceased to be true sulphurets ; for sul- 
phuretted hydn^en was generated, and they passed to a new condi- 
tion ; that of the sulphuretted hydro-sulphurets. In making the 
preparations, it is of litde importance whether we boil the base wtA 
sulphur together, or melt them together, and then dissolve them; or 
whether we dissolve, in hot water, the residuum from the decomposi- 
tion of the sulphates, by ignition with charcoal ; for, in either case, 
by the decomposition of water, we obtain a compound conuiumg 
sulphuretted or bi-sulphuretted hydrogen ; it is fetid, and acrid, and 
liberates by the action of acids, precipitated sulphur and sulphuret- 
ted hydrogen gas. In all these cases also there is a generation, 
probably from the oxygen^ of the water, of some of the acids of sui- 

Ehur, and by spontaneous decomposition, especially if the solution is 
ept in loosely stopped vessels, the substances pass to the condition 
of sulphite or sulphate, j| and thus lose their peculiar properties. 

n. SulpkureU of the metallic baaet ^ the fixed tdkcUtet andalia- 
Uae earth*. 



* In the litter c«se they n 
Ijr b« eihiblted pure ; 1( dot 

t Theralbre culled. In the old Iioguege of chemutry, hepar lulphuria or liver of 
■alphur. 

t Phyrieluii prepdre the lulpburet «t potMb by iBking; Bonen at lulphor and 
poteih or petrl uhes, equil qaaolitiea; the j are nielled in * covered crodble or 
■ktllet, end then kept ia a cloie vcskI, but are dusolved for uw, in (he proiiortiMi 
of two dnmi in ■ pi^at of rain water, tad thU Is uwd an an exlemat wash. A (able 
■poonfullatakenforidom.lwleein a day; uied forBttrletr of eruptkui>,M»Idlm<l, 
paara, &c. In pulmonary eoDsuinpllon it miy be glFen, in ttie above manper or in 
,Kmi of pllli, from two to See grains for a dote, repeated two or three tjmea in i dif • 
ItnimoveaordiiDtalshes the hectic fever: it has been uwtd iotemally u inulHloM 
against nbclaliic poisons aad to check excessive salivaliooi [ma mercury. — Oan'i- 

t Vauquelin supposed from the oiy^n of the alkali. 

II The preparation from the decomposed sulphtte of baryta, la particularly re- 
narkabte for paaaiog back to the condilioi] of nilphate, and it often preaaata dMinct 
ic crytala. 



OMzcdoyGoOglc 



suLPHUBtrra. 3fiS 

It cannot be doubted, that many of the tximpouuds wluch were 
fiwmerly regarded as sulphurets of the oxides of metaUic baaee, were 
realfy sulphurets of the metalg tfaeinselves, and it is now clearly as- 
certained that they are fumed in the following modes and circum- 
stances. 

1. Byfiuion of the foetallie bate with stilpfair, or by patting iu 
nmor over the metal, igrtited in a porcelain tube; the union often 
takes place wiUi the diflengagement of much heat and light, resem- 
bling a combustion, and by many it is regarded as sucb. Potasaum 
and sodium are the only alkaline bases which we are able to try in 
diis way ;* the same thing happens with silicium. 

3. By heating the metdlie batet in mlphvreited hydrogen gat, 
when the sulphur combines with the metal, often with appearance of 
combustion, and the hydrogen gas is liberated ; potassium and sodi- 
um exhibit this phenomenon remarkably. 

S. By pasting the tame gas, or its totution in water, into the metal- 
ic tolvtion, when sulpburets are precipitated ; those metals that are 
not afiected by sulphuretted hydrogen, namely, iron, manganese, 
nickel, cobah and uranium, are, like all the other metallic solu- 
tions, precimtated as sulphurets, by the hydro-su ^burets of potassa 
and ammonia. 

4. By heating tvlphur to ignition wiith the oxide of the metal; the 
oxygen escapes m sulphurous acid, and the remainder of the sulphur 
combines with the metal. 

5. By ignitittg the tvlphate of an alkaline oxide with dtareoai 
powder,f or by patting ine hydrogen gas over the ignited sulphate ; 
all the sulphates of these bodies are thus reduced at a white heat and 
if fusible, very quickly. Perhaps the true Umit between the aul- 

E burets of the fixed alkalies and alkaline earths, and of their metallic 
Bses, will be found below a red heat for the former, and at or above 
it ibr the latter. There cannot be any doubt that true metalhc sul- 
pburets are formed, when the alkalies and alkaline earths are igni- 
ted with sulphur, or when a sulphate is decomposed, at a similar 
temperature, by charcoal or hydrogen.i^ 

It is remarkable that during the dectnnposition of the sulphates by 
charcoal, the gases disengaged are found to contain the whole of the 



M irm, (Sppar, leiid and Mnnuth, exhibU tUi 
phCDomciioD in > MriUDg mioner ; tbe two fcrmer ibaw It In ■ gltM tmmI. 

( Mr. Bai-flUar eDclned (he lult^ale In * Mvared crueiUe Uiwd wilb a mJxtnTs of 
day and charcoal powder. 

t Tba Bmitaof tldi work do Dot allow me to cite more Id detaU, the labon of Tau- 
qnelio. Ana. do Chim. et do Phyi. Vol. TI, IBIT.or (faoK of Gar-Liurac, Id. or 
of Borthler, Id. Tol. XXII.orof BeneUiu, Vol. XX. A peraHcinnu itatemcnt 
drawn from theio anthorltle*, maj be found In Dr. Tnnsr'i ChemMrj, 3d Ed. 
p. SaB; I find that It cootalni every thing of Importance inlheoriglDat ineoMin. 
45 



OMzcdoyGoOglc 



S64 suLPmnsim. 

cnrgeii that existed, both in the oxidised base and in tbe aaljriwric 
KCkd ; and wbai hydrogen is empkmd, the mtet {woduced* aCoamKi 
ID the same manner, fiirthflwhols of the oxjgeo, and tfaareisia oUwf 
caw, no loss of sulphur, as it bB remains comUned with die metalbe 
base forming a true metallic sulphuret. 

When the Bul|Aiirets of the metallic bases of U)e alkaline sub- 
tlanoea are dissolved in waier, they pass at ooce, to die coadkion of 
hjdro-sulphureta and sulpburetted hydro-sul^nirets. The deoo«D- 
postion of the water af^Mara to be the aaeans of efiecdog these 
changes; its oxygen causes the metal to pass to the state of oxido, and 
its bydn^en with a part of tiie 9u^>bur forma sulphuretted or bi-wl- 
phuretted hydrogen ; some of the acids of sulphur are slso lonaed. 
When a sulphuret is obtained by the decompoeitioti of wlpbate of 
baryta by charcoal and beat, and subsequent addition of bouiiig wa- 
ter, there is produced, from a strong sohiuoii, a very copaous and 
Hidden depoaitioa of white crystalline plates of hydro-sulpburet of 
baryta, while a part of the fluid appears to remun in the condilk» of 
sulphuretted hydro-tulphuret or bi-bydn>«ulphuret of baryta. Sul- 
phurous acid or bypo-eulphurous acid is also [Hwluced, &nd corabD- 
ing with a portion of the oxidized base contributes to expel niore sul- 
phuretted hydn^en. 

In cracludiDg this rather complicated stili^t, it may be well to 
call to the recoSection of the learner, that the following are its great 
divisiona. 

1. SuJpharetted tmd bi-^tdphuretttd ki/drogen, coDtainiDg sulfdair 
dissolved m hydrogen ; one proportion in the former, and two ia the 
latt^-. 

2. Hyiro-^ulphurttt, connsting of sulphuretted hydrogen, and an 
oxidized metallic base* of an airline substance ; in otlwr words, of 
aa alkali or an earth. f 

3. SidjAia-etted /u/driMiiiphweU, consisting of bi-sulpburetted hy- 
drogen, and oxidized metallic bases, viz. alkalies and earths ; ]^ro- 
b^^ containing also variable proportions of sulphur dissolved, beades 
l^at is united to the hydrogen. 

4. SvlphureU of the alkaliet and earths, formed below ignition. 

5. Sulphvrett ofmeiaUic bates, formed above i^tion and con- 
taining no sulphuretted hydrogen, nor &try uacombined sulphur. 



* Ammonlt baing dwayi excepted u lUTiog i diffignnt coruIltntioD, but ilillt It 
lomi k Inie hydro-iul^ure^ ind one of tbc moit aseful. 
t The cvmBioa meteli are not here brought (dIo view. 



D„tiidD,Googlc 



CARBON. 3(6 

Sec. II. — Carbon— carbo — Latin. 

1. Iti impo'rtance ahd wide oirruBKM. 

(a.) ^ eleaieni of gnat xnterat, diffiised tbtowh ths aaioUl and 
vegetable kiDEdom&, and largety b the mineral, either in the form of 
carbon or carbonic acid, Iree or combined. 

(&.) Known to t/iA atidetUi. — Theophrastus Eresius, pupil and suc- 
cessor of Aristotle, mentions charcoal 300 hundred years bafbra 
Cbiist, and Pliny describes the process of burning it.* 

2. PaiMCIPAL NATDIUI. rOSMS AND VABIETIES. 

(a.) Diamond. — It differs from chsrcoal, in being » Doa-conduo* 
lor of electricity, and in nearly all its physical properties ; ti3l it 
it pure cr^aUiixd earion. 

The proof reati on the fact, that it it entirely combuttibie i that it 
it converted into carbonic add gat, viibaut any other product ; and 
that it forms steel by cementation with soft iron.f Toe condiustion 
is efiected without difficulty, in pure oxygen gas ; under the compound 
blowpipe, and in meiled nitre. It differs from charcoal mme in 
its state of aggregation,^ than in its chemical relatifms. Still it i> 
muoh harder than we imagine ; a mass of vegeuble charcoal is Hght, 
beoause a great quanti^ of matter hae been expelled in the aeri- 
Ibfm state, and thus the substance is made to appear both soA and 
Kght ; but its integrant parUcles^ are hard, as will be peeeived by 
^icdii^; them between plates of window glass i^ich they will 
scratch, and it is stated on the authority of Prof. Leslie, thai 
the sp. gr. of charcoal is really greater than that of the diamond. 
Cufaon exists in a transparent state, in the oUa and in alcobol, and m 
crystals of white sugar, from all of which it is easily develofwd, by 
bmt, adds, and other aceots ; it is found also in several gases. 

Jb.) Pldhbaoo, or black lead. — The proof that tfdi it nearly pvre 
Wfi, is the same ; it produces carbomc acid by eombustioD, and 
there is only a small residuum of iron and earthy inqiurtties.[| 

(e.) Amthbacite. — ^The same remark may be made of this ; it 
it nearly pwe carbon. 

There seems no reason to doubt that the ^obulet which I obtained 
in 1^3, from the plumb^o and anthracite, by the dedagrator, arose 
m part, from the earths present in these mmerals ; but witb charcoal, 
I wactive it to have been otherwise, (see note, p. 358,) and the 



■ Firkei* Emrji, Vol. 1, 896. } PliQ. Tnn*. tSlS, p. >7I. 

t CtnrcMl li dM more dlfloratit tram dhmoud, thaa clay or pure pulTereleal *Iu> 
mliim 1« from Ibe tipphlre ) or cbilk fratn Jceland cryitil ; or pulvemlent mtgnai^i 
ftom the mne in the boradle ; or than quarti oecliqaB, (nrlmmlnj; £faitj from rack 

J So, the iDlemnt particle* of punice ttoae tad tripolt ve bard, altbogsb tb« 
ntm it nft, and VM of the fanner ia veir Uglit. 
I For Its MMlpta, Me Am. Joor. Vol. X,p. lOS. 



OMzcdoyGoOglc 



3S6 CABBON. 

compound btowpipe, eridently eSbcted the fusion of ibe entire pluiD- 
baco, includbg the carbon, the earths snd Itod.* 

{d.) BiTcwifouB coix. — T7u haiit ofthii m carixm, which, ui>' 
der the name of coak, b obtained, after the bitumen, the inSamniable 
gas, and other volatile ingredients have beeti expelled by heat. It 
contains some earthy and metallic impurities, but bums away almoot 
Mitirely in oxygen gas, producing carbonic acid. 

3. Abtificiuj chakcoal. 

(a.) Chahooaij u,i^ierth£ diamond, thepttrettftyrm of earioH i it 
M pr^ared ui the large way, by a motherM coainatuM ef bUl^t <^ 
wood, properly arranged, so as to admit a very partial sujnJy of air, 
through holes at the bottom j the pile is covered with tun, eartfa or 
day, except a few spiracles, or one hole at the top ; and dbese are 
stepped, when the dark smoke is replaced by clear whitish clouds. 
Tne emisuon of volatile matter, consisting of inflammable gases, va- 
por of oils, and water, and pyroligneous acid, and other things, chem- 
ically or mechanically raised, finally ceases ; and the heap is sufiered 
gradually to cool, which takes several days or weeks, according to its 
size. 

The principle of the process is, that the combustion of a p(H> 
tion of the wood produces strong ignition in the remainder, and thus 
expels everr thiug volatile. 

(6.) Its formation may be shewn, by plunging nudlpieat <^waod 
heaeath mdted lead or (in,f or beaeuh sand heated to rednets in a 
crucible, in a furnace ;{ when cold, it should be immediately removed, 
and corked up for use. 

(c.) Pr^ared'alto in cast iron cylinderi, for the manufacture of 
gun powder,^ and the charcoal is the same from whatever wood pre- 
pared, althourii alder, dog-wood, and willow have been herettu(x« 
preferred. The cylinders are placed across a fiirnace, and there is 
vent only for the aerial matter, conasting of inflammable gas, pyro- 
ligneous aeid|| and lar, all of which are usefiil products. 

4. Pbopibtixs. 

(a.) Black, brittle, Mhining, inodorous, and eanly pulverized ; it 
is «o porous that it is easy to blow through it. 



* Sea Am. JiHir. Vol. TI, p. tSS. 

f Arrangement /or riou exhUnli»n.—A small asrtheo firnice, filled wllb bom- 
ing divcoa), kneported by brickaori ■lone upon ■ table, udupoo Ihlireatia Itm 
lule Dearly fall oi melted lead, which ahtnild be nearly red hot, and the wood hdd 
byimall tonga li phinced beneatli It; the fluid metal will boil vahementlv, and lb* 
hulammiblv gii, may be fired as It riaei ; Hhen all is quiet, the charcoal !a dST*!- 
0|>ad, and may becooledbenatth mercury. ) Ailiia, Tel. II, 286. 

\ Or itlll more Deatly, by wraj^ing a piece of wood in pUtiu* (Ul, and holding la 
ths Same DfaleehoUc lamp. The Hberatad gaaei take fire and burn brilliantly, lud 
wfi]} fanned charcoal temaiiu withbi.— J. G. 

'H The rbarcoal made in Oiis manner, li kepi from the air whenit lalo be UMdIbr 
the manuftrtur* of sod powder ; U hai not more than half (he ipsrific gnrHy of 



OMzcdoyGoOglc 



CAMWN. 3S7 

(i.) Undumgtd by Aeof, in closed vessels, except that it grows 
firmer, and haraer, and blacker, and shrinks ; it will then very de- 
cidedly acntcb glass, wd wear a file.* With the best pieces, one 
can write his name on window glass. 

(c.) Unaltered by mr and water, and exempt from decar. 

\d. If well prepared, it conducti eUetridty, but is a bad conduc- 
tor of beat.f 

(e.) When ooce thoroughly made, it retains for a kng time, 
its power of cmductmg electricity. Skated without contact of air, 
it emitM itvSavimable gaiu andniiroeen.X 

(/.) ^er being ignited, it abiorvigatet withovt aiteration ^ this 
is shewn by placing oa the quicksilver bath, a piece recendy extia- 
gaidted, and covered by a jar. This power is much diminished by 
polreiiziDg die charcoal. "iHie following are the results of Satis- 
siaie, with box wood charcoal, the most powerfiil spedeg ; the time 
was from 24 to 36 hours ; the charcoal was first ignited, cooled in 
mercury, and then placed in the gas. 

Gaseous ammonia 90 times the vdume irf' the charcoal ; do. mti- 
riatic acid 85 ; suljidiurous acid 66 ; sul^uretted hydrogen, &6 ; 
nitrous oxide, 40 ; carbonic oxide, 35 ; olefiant gas, 35 ; carbcHiic 
oxide, 9.43 ; oxygen, 9.35 ; azote, 7.6 ; light gas from moist charcoal 
5. ; hydrogen, 1.75 ; very light charcoal scarcdy absoihs at all. 

The power of absorption in charcoal bears no relation to iu chemi- 
cal attraction for the gas or vapor, which, by heating the charcoal, is 
in geoeral recovered unaltered. 

Those gases that cannot be ctHideosed into the liquid state, are 
ibt least aDsot4>ed by charcoal, and die reverse is true, very nearly 
in proportion to the ease widi which they are condensed. Vapors 



uied in EngliDd. Abunduiceofanibituicellketu'iipradiiced, which Mr. Puku 
Nfi li an Moallent ptoMrraliTe of wood, igiliat dsaj uhI inaeeti. — EtMyt, Vol. 
I.p. >M. 

Th« praporlloD of chu-coil obUliMd from dUferont woodi Tmiiaa frem IS to M par 
Mul; uwiTengsof at triili gar« netrly 20 per Mnt — Parked EauirTol. I, 
p. 406. 

Fir gave 18.17, Ukdoid vitti 17.ae, box Z0.2S, Ueeh 15, oik 17.40, iMbonnv- 
16.TS.— Alkn ukd P^r«. For ■ fuller lablc, boo p. >6S. 

Wood, boroed In tba open Ur le»«i oal* about l-200th, or l-lSOtb of Ow mwd, 
bat the chtreotl la laid to contain l-SOth of ita we^bt afalkallno and ewrthj w^tia,— 

* Even in Ita commoQ rtate, good chaTeoal wili wear window glaaa. 

t I,ampbl«ck ia preparad from the combiution of oUi and nMna. Wa Bttf ool- 
hel II bjr raMtvinf Hie HDoka of a lamp upon a nuoar, or b; bomlnc a pi«e« of 
p^kDoter T«alii,midaranqMi>dedaBcldns. Inlba art*, the refu«e nma and^tck 
are burned in ■ menliar fiiriMKB, lurnlahM with kng fluea, terminating la a doae 



OMzcdoyGoOglc 



368 CARBON. 

are more ea»i\y absorbed than gases, and liquids niore eujly stiO. It 
evidentlj- depends upon the porous fbnn of the charcoal, and plum- 
bago does not possess it at all. The power seeme to be analagous 
to that of capillary attraction in other st^ds. When oxygen n ab- 
sorbed, carbcmic acid is formed at the end of seTeral intHiths ; if char- 
coal is impregnated with sulphuretted hydrogen, and exposed to tbe air 
or 10 oxygen gas, sulphur is evolved, and water formed, the gas 
being destroyed, and conaderable heat produced, so as, in some 
cases, to produce in a few minutes, detonation with oxygen gts, and 
more or less heat is always evolved vriien gases are absarbed hy ckust- 
coal.* In general after 24 hours, ^e absoiption is not increased, ex- 
cept in the case of oxygen gas, which goes on absorbing for years, 
ht consequence oflhe formation of carbiMiic acid. Tbe gas is easly 
exinctea l»- tbe air pump, and during its extrication, cold is pn>- 
doeed. Charcoal which has absorbed a gas will gtre k out eo- 
iBely by being heated again, and very striiungly wim abuMition, by 
plunging it into boiling hot water. The diarc^ can he as e^ct- 
ually prepared for absorbing gases by the air pump as by ignkicn.f 
TbiB property is common more or less to all porous bodies ; asbes- 
tos, silk) meerschaum, adheuve slate, agaric mineral, wool, linen 
thread, plaster of Paris sobdifled by water, fiic. have been made sub- 
jects of similar experimmits.l 

(g.) By expotnre to the air, cHareooi increa$t$ in vti^, by ab- 
sorption of water, air, S^., J of which is water.^ By a weeV^s ex- 
posure, lignum vitse gained 9.6 per cent., fir 12.0, box 14.0, beech 
16.3, oak 16.5, mahogany IB-O.^-jlUen and Pepyi. 

(A.) InfiuihU by any heat which we cad apply, except that tf gal- 

(t.) Imoltthle in water, although at a red heat, it decomposes that 
fiuid, (vide carburetted hydrogen.) 



it dT ilMMptioa; 26° Id As c 



t Ciwrv— Whether kIn Ibr condnetiDg eiItmUici, i 
} Turner, Sd Ed. p. SSI, lod TMel.in SWdrger'i J 

JChirccal abaorlw from sir more oiv|^d Ibui nit 
confined in elr, ovtr mercury, It left only 8 pei 



—Vhether kIn Ibr condnetiDg eiItmUici, lod for aotlnplie (geacj? 

. _ a nltrof^n; whaa reeeoUy ignited 

rcury, It left only 8 per cent. ; and if from k itala of 
liili ignltioD, it be plunged Into wtlnr, tud then eooSned hi elr over menrnj, ttte 
onfen ii nekriy or quite til abiorbad, leB?))ig, w !■ raid, pure nitmgeD. We en not 
innnmed whetlwr the pure oxygen nn Im recovered by beatiiiKllM chtrcoal. 

H Fiitita^Aareoalbjikt u«aof Dr. H*re'i DefltgrMor. The polei being t«r- 
mmUed by well prepared ebwcoal, tknobef fiMed nutter appetiw on the copper or 
nentfre pole, HinMlloMa half an Inch bi Unglli, white « OTity, eorrMpeodlng In 
powtten. appeara ob the mtaic or porfdra pole, and If the pieces are latde to efatngs 
plMM, the kMb and cavlqr are truuferrml froea aide to aide. The knob a^eva 
to eome from die oppoette pole, •«! la evideotly derived ftom the chaicoal. It I* 
very diffieoK to Iwrn, bat If bmUd elflier In oTfgm gai by the aun'a raye, ot 
In ewnmon air, or tntxed with nitrate or chlorate of potaA, h predncw eutenic 
■cid. On an Ignited inm In the air, it wiatea alowly away. It i* OMoaa and jflf 
teiJiif. with MOii-BietilUc hueai tie color gray, or almoft Uaek; not fibrou* or 



doyGoot^Ic 



(j.) Pirated into mflrciuy, or merely restbig on it, il absorbs 
much of that metal into its pores. 

(k.) Heated » ccmtact with cwwdihi air, it burnt aaaif taUirtty ; 
vtrg rapidly, tod wholh-, if immersed tit oxygen gat in suffident 
(Quantity. A piece of charred baric burns best, and with lively acin- 
tilladons. 

(/.) Sulphuric acid boiled on charcoal powder is decompwed, and 
sulphurous acid gas is liberated. 

(ffl.) The decomposition of the sulphates by charcoal, is a striking 
ioslBDce of ^ actiim on sulphuric acid. 

(n.) 7\> prepare charcoal for clar^eation ; take that which is weQ 
homed, pulverize and sift it ; heat it strongly away ftwn the ah-, as 
in a crudble with a small hole in the cover, or covered with sand ; 
it must then be boUled tight, till it is wanted. 

(o.) Tindi^e ofalkojiet, diluted with water, mixed with well pre- 
pared charcoal, and simmered over the fire, and then thrown upcm a fit- 
ter, comes through perfectly limpid. Mixed with common vinegar or 
wine, a thick froth rises, and the Kquora are clear alter fikradon. It 
is sometimes necessary to boil the vinegar upon the charcoal. 

(p.) Ditch, sink, or puddle watenr, or even that of a sui^eon'a tub 
b thus rendered limpid, inodorous, and insipid ; and rancid oils are 
restored by repeated filtration through charcoal. 

{q.) Theprgiared charcoal it an exeeUetU dent^rice f that from 
the shell of the cocoa nut is preferred ; the charcoal of the kernels 
of nut fruit is very delicate, and thai of carbonized wheat bread is 
veiy good.* 

(r.) Solutions of impure acid of tartar, crude tartar, crude nitre, 
and other salts are rendered cokirlesB by being boiled with charcoal 
powder, and are thus made to crystallize in scow white purity. 

(t.) Impure carbcmate of ammonia, subfimed from an equal weight 
of charcoal powder, is repdered white and deprived of its foetid 
smell. Charcoal also destroys the heavy sickening odcff arisine from 
oiled and gummed silks, euch as those of which hat cases ana um- 
breUa coverings are made,- and it speedily removes any unpleasant 



portnu ', It hu no rewmblHica to Ghvcoal ; (tolu u raa^ilf in ttronj; Bulphorio 
add, u it bebre floated on water nllh its Toluroe hair nut ; lit gnvily Wu there- 
lore JDcreued four tiniei, pampered nitb Ihe ch>T«iMl in laaM. 

This obiervBtlon tru IJiBt made by mjself in March 1823, nd bM bMH KpMl- 
td many timsi «□<:« ; with a powarful def1igrator,lt comtantly occun. The raty. 
stance reienibles greatly, the reEiduum found in the Iron gai bottlea, and there 
MMD* M reaaiMi ID doobt that It proceeds from the volatltizalloa and fudon of Iha 
ebircMl tioug will) wbalevM iareisn nbaUDCe* it may omitain. Tbeobjactiooi. 
ofFraC Vunisem aeeta to have ranted to a difiereni nibstnice. — Am. Jour. Vol. 



"'ii 



e of Ihe very beM denllfricef ; for, besidei the carbon, there ai 
delargenl iiDDiiniucal silta, and a bitter princi|ile, and other active tgenU. 



D„tiidD,Googlc 



dBuvium from clothes, be. by being wrapped in tbem. " It abo 
sweetena bilge water." 

(f.) Malt spirits, disliiled from charcoal are deprived ofllieir disa- 
greeable flavor ; if too much charcoal is used, the split is docom- 
posed, aa is vinegar also. Charcoal, fw this purpose, is prepared 
by heating it red hot in a furnace ; it is then ground in a mill and 
ImrreQed or put to immediate use by having the spirit placed over iL 

(u.) Eight or ten pomids of the spirit macerated lor eight as (en 
daf s on two ounces m charcoal, is improved in flavor. 

(o.) ^ater become putrid in cadts, is restored bnr fihradon 
through charcoal, especially if a few drops of sulphuric acid be added. 

(aJ) The odor of alcoholic solutions of resins and balaams is not 
destroyed by charcoal, although their color is ; essential oils do not 
lose their smeD. 

(x.) Distilled waters and many vegetable tinctures, and litraus, 
and indigD, and other lakes and pigments, become cotorlesa when 
their aqueous solutiona are filtered through charcoal. 

(y.) Gum-resins, aa opium, assafcetida, be. suspended in waio', 
lose their odors. 

(z.) Tainted meat is restored by rubbing or boiling it with charcoal 
powder ; and if daily renewed, it preserves meat from pHtrefaction. 

(aa.) The inside of water casks is charred to preserve the water 
from putridity in long voyages, and the ends of posts to keep them 
fitm rotting. 

(bb.) The facts under (f.) and (u.) are true of rum and other 
vanedes of ardent spirit. 

(ec.) Proper proportion is essential to success in diese experiments. 

(dd.) lie none portion of dmrcoal, if re-ignittd, may be vted 
rvptatedhf. 

(ee.) Amaud duireoal ii a more powetfvJ oiUuepfu: than v^a- 
bie; it is (Atained by caJcining bones in close vessels.* 

(ff.) Charcoal, if undisturbed when in the act of being fbnned, 
pretervei the organixatum of the tvbttaaee from which it it derived; 
" die wire marks of paper and the thread of linen, are sdll seen wiA 
distinctness," after being carefully bumed. 

Grains of wheat and rye charred in Herculaneum, by the volcanic 
eruption, A. D. 79, were easily distinguished from each other, and 
an arrow head has been charred so as to pr^erve the form of tbe 
feather.— Porite*. 

{gg.) Tfte charcoal of the heatnett wood reqtaret moet air, and 
give* the most heat, and b best fitted for the reduction of metallic 
oxides ; " while filter wood preserves a glowing beat with a less 
draught of air." If wood he stripped of its baik before it ia carixm- 



■Am.deChim.n, 80; Jour-ofScfeoce, IV, 867. 



OMzcdoyGoOglC 



CARBON. 361 

iaed, it does not crackle and fly- For black crayons, willow affi»ds 
the best charcoal, it being imiiormly soft. Ivory black is the coal of 
ignited ivory prepared in close vesseb ; the commtKi ivory black is 
often made from bones. 

(AA.) The durability of charcoal is seen in the figures on the dial 
plates of steeples, which often stand out in bold relief, while the rest of 
the -wood, painted white, is worn away. 

(n.) Ijampblaekf igniied in a crucible, and coded before it is un- 
covered, and the diarcoal which is procured by pauiag the oapor q^ 
oilt or of alcohol through ignited tvbet, it tM purat carhoa that 
art am prepare. It is an impalpable black powder, and man than 
twice as neavy as water.* 

{jj-) Biitre, a beautiful brown jugment, u prepared jrom on 
aqueous itdution of wood toot. 

{kk.) Animal chareoal it more dente and leu comlnaiible than ve- 
getable, and contains phosphate of iron ; it is distinguished from ve- 
getable, as the latter bums on an igniied iron into white ashes, form- 
n^ a Iwtterish liquor widi sulphuric acid, but the residuum of animal 
matter is much less soluble, and forms a compoimd having a very di^ 
ferent taste, f 

(U.) Chareoai ii very effectwd in depriving treacle or moUutet of 
itapeetdiar taste; twenty four pounds, diluted with an equal weight 
of water, and boiled for half an hour with ux pounds of pulverized 
charcoal, were entirely deprived of the empyreumatic taste and smell, 
and bemg strained and evapwated lo a proper consistence, had the 
flavor of good sugar J Honey may be treated in the same manner, 
and with die same efiect.^ 

(nun.) The dve pr^araiion of charcoal ii of the lait consequence 
to swxess in these operations. — Common charcoal is almost inert } it 
is indispensable that it be freah made ; or re-ignited, and that it be 
secluded &om the air till it is used. 

(nn.) Chareoal is used in polishing brass and copperplates and 
lanthom leaves ; in tracing the outlioes of drawings, and in giving 
stxne peculiar tints to glasses colored in imitationof thegeiDs.|| 

(oo.) 3%£ andents Xneio that duxreoal vriU not (jecojf.-— The piles 
driven, more than than two thousand years ago, in founding the tem- 
ple of Epfaesus, were charred, and those that support the houws 



t PvkN- Emya, Yd. I, o. 414. 

' ' hu bMQ ipplled to ths rafining of aigv, ind ■ pilsnt wm MkMi oat 

. _ tn m Id London. Hr. Pvkcs tjm, that ,finer MavM of mgia thtn 

muiQbclured it in j olher uubtlihineiit In London^ were *i he MppoMi, pro- 



OMzcdoyGoOglc 



in Venice had undCTgoae tbe Mine process. Dr. Robinson, in his in- 
tnxluction to Dr. Black's lectures, says, "About forty years ago, t 
number of pointed stakes were discovered in the bed of ibe Tbaines, 
in tbe very spot where Tacitus says that tbe Brit(»is fixed a vast 
number of such stakes, to prevent Julius Cmsax from passing his 
army over by that ford. They were all charred to a considerable 
depth, and retained their form compl^ely ; and were so firm at tbe 
heart, that a vast number of knife handles were manufactured from 
them, and told at antiquet, at a high price."* 

5. PoLiRiTT. — Electro-posiuve ; ii is attracted to the negative poie. 

6. Combining weight 6, hydrogen being 1. 

7. Medical and other uses. — A preference is entertaiaed by 
some for charcoal made from particular substances, as Erom cedar or 
cork ; it should be newly prepared or recendy heated.f It is tbougfat 
to correct a vitiated state of the stomach and bowels, and has beat 
celebrated in some stages of dyspepsia, and in dysentery and other 
diseases of the alimentary canal. The dose cannot be critical ; from 
10 grains (o a table spoonful may be given, two or three times a day.{ 
It b applied with much advantage to foul ukers, whose fetor h cor- 
rects, and in die form of poultice to sores that are tending to gan- 
grwie. 

8. Miscellaneous. 

fa.) Charcoal is said to be better if tbe bark is left on tbe wood, 
^riuch should not be split ; pieces of six or seven inches in (hameter 
are ea»ly charred.^ Coak is the carbon of mineral coal ; it is pre- 
pared by a process resembling in principle that for charcoal ; it pro- 
duces an mtense fire, and is much used in England in tbe manuftc- 
tures, e^iecially of iron.[| A charcoal is also extracted fi-om peat. 
The following table shows die proponkm of volatile matter, charcoal 
and ashes, in 100 parts of di^rent woods. — Urt. 



* I saw one of (heae alakei in the Britlah Museum ; Iha churrtnl oa tht Mtad* 
and the wood williLn, were apparently as perfect at the day it was driven. 

t If it l« 10 be applied on a foul ulcer or toie. It nhouid be taken red hot rram the 
fire, pulverized immedilleiv In a metallic mortar, and used as soon a> cold, and any 
thit romaina ahould be bottled, tight from the air. t Coxe. 

\ it is conjectured (hit in the charrln;; of wood, porllani of It are aoiaetlipeg cos- 
Terted inln p^ rophonu, and that eiploalau in powder mills may occaalanilly be 
owing (0 this rauie, 

June ton of Mluminona coal yietda from TOOlo 1 100 tba. of coalc. Much bitumen 
other volatile products are loat In Ibe usual way of charring, but Lord Dando- 
nsld, bv heating the coal In a noge of elehleen or twenty sdnes, with ss little le- 
COS of air as posaibie, and conducting the smoke tbrouKh hartioQtal tunneb, ud 
finally into a bHck tunnel 100 yarda long, and covered at lop by water, succeeded 
In obtsJulng nearly 8 per cent, of bitumeo in the form of tar ; 39 barrels of It yielded 
U of tar, and the volatile ]Hrta gave materiais for varaiib, besides ammonit.—tn'e. 



SULPHUBBT OF CARBON. 





Malter. 


Cbwco.: 


I.AshM. 


Charcoal by 
ProuM. Rumfbrd. 


O^. 


Tn.B96 


22.083 


0.428 


30. 


48.00 


Aab, 


S1.2Se 


17.972 


0.768 


17. 




Mrcb. 


60.717 


17.491 


I.7W 






Norway PlM, 


80.441 


1S.204 


0.85S 


20. 
Bluk Aih. 


44.18 


MkboEur, 


78.6W 


25.4W 


0.9S0 


26. 




SycMaore, 


79.20 


».7a4 


1.066 


Willow. 




Holly. 


78.01 


19.918 


1.169 


17. 

Hc^oTOtk. 




Scotch Pine, 


68.090 


IS.4M 


0.449 


19. 




Beech, 


79.104 


16.941 


0.9W 






Elm. 


79.8BB 


19.674 


D.761 




43.27 


WalDiit, 


78.631 


30.668 


0.816 








7B.381 


19.901 


0.768 


Gii»i»cum. 


42.a> 


Do. Blick Beeeh, 


, 77.SI3 


31.446 


1.083 


24. 




LAbumum, 


74.2U 


34.S86 


1.180 




W," 


ix;?"-- 


72.013 


2e.8£7 


0.600 




80.371 


18.497 


1.182 
















Line, 


Cheoial, 


76.304 


23.280 


0.410 




43.69 



(i.) Charcoal, tn theform oflampbltuk and plumbago, it among the 
mott enduritw ofpaintt, andfotvu a firm body with oU. Plumbago is 
used for lubncating machioeiY, for making crucibles, for protecting 
iron from rust, and to give it lustre. Charcoal wiih oil fonos print' 
er'a ink ; with sulphur and nitre, gunpowder ; wiUi iron, by cetnenU- 
tion, steel ; it is used to exclude or to confine heat ; it is a veiy ex- 
cellent fucj, and it b employed widi advantage, after being ihorou^- 
\y ignited, to surround that part of lightning rods which enters the 
grou ad . — ThinaTd. 

(c.) Charcoal is of gnat utQity in reducing the metah,hoih in raising 
the necessary heat and in detaching oxygen from the oxides. Carbon, 
in the form of diamond is the most beautiful of ornamciiis, and the 
best substance to cut glass, and to afford a cutting powilt:]- tn polish the 
hardest bodies, diamond itself not excepted. The water of ilie Seine, 
rendered turbid by mud in the winter, js purified and made potable, by 
passing through charcoal, placed between two layers oi sand, and 
these between two others of gravel and pebbles. — Id. 

(if.) It u exceedingly abundant tn nature ; it exists in all animaT and 
vegetable Iwdies ; iu all the varieties of natural coal, and bitumens, 
and petroleum and naptha ; in the carbonates of lime, and other min- 
eral carbonates ; in carbonic acid, both free in the air, and dissolved 
in water; and in the carburetted hydrogen gases and carbonic oxide; 
and its chemical and natural history involves a vast number of inter- 
esting and important facts. 

sulphubet of cakbon. 

1. Pbepajution. 

(a.) A porcelain tube, one inch and a half m diameter, coated with 
fire lute, and partly filled with fragments of recently ignited charcoal, 



OMzcdoyGoOglc 



3C4 SULPHURET OF CARBON. 

is placed a iitUe inclined across a furnace ; al one end a recurred 
class tube dips into water, aud the other end is open. The furnact 
being in action, a fragment of sulphur is pushed al<Hig by a wire 
dll it b near the charcoal, taking care to exclude the air as much u 
possible ; the open end of the tube is tben stopped, gas passes in 
abundance, and a liquid collects beneath the water ; more bits of 
sulphur may be intrcduced, till enough of the liquid is obtained, and 
it is said that half a pint may be procured in a day. 

(6.) The following process I find to be a good one. A tube of iroa 
is placed across Blsck^s furnace, as a protection to a tube of jporcehin 
which is passed through it. A glass flask contuning flowers of sulphur, 
coated with lute of sand, clay and rye flour, is connected with one end 
of the iron tube, and at the other is » glass tube passing into water, 
comained in a vessel surrounded by ice. Pieces of charcoal, recent- 
ly ignited, are placed in the porcelain tube, and heat is applied bj 
a chafing dish under the flask ; the sulphur is slowly volaiiliwd 
through the charcoal j the two combine, and the desired yelJow liquid 
drops from the mouth of the tube. The piincipal point is to bring 
(he sulphur into conUct with the charcoal when it is very hot and 
has ceased to emit gases. 

(c.) Another process, stated also to be a good one, is to distiJ M- 
tive iron pyrites, (bi-sulphuret of iron,) with one fifth of its weight of 
charcoal powder. 

3. Pboperties. 

(a.) After being re-distilled'atalieat not exceeding lOC^orUO" 
Faiff., from some dry muriate of lime placed in a retort, it is wfor- 
fc«, transparent and lin^id;* its refractive power very hiefa. 

(&.) Tattt acrid, pungent, and somewhat aromatic; ttneU nauteoui 
and fetid, but unlike that of sulphuretted hydrogen. InjkmaiMe, 
and its combustion produces sulphurous and carbonic acid gases. 
Iiuolvile in water. 

(c.) Sp. gr. 1.27; boils at 106'^ or 110°, does not fi^eze at 60°; 
very voldile, at 63.5 Fahr. its vapor sustains a column of mercuiy 
7.36 inch high, and during its evaporation prodiuxt to much cold at 
to freeze mercury. The tnermometer ball is covered with fine Jint, 
moistened with the liquid, and placed under the receiver of an air 
pump. A spirit thermometer at the same time Indicated —80. 

(a.) Not decomposed, by heat alone, at any temperature; hulitis 
decomposed by being transmitted over ignited iron or copper lurn- 
ines ; also far peroxide of iron ; or by heating potassium in its vap^""! 
when there is a brilliant ignition ; the sulphur always combines with 
the metal and liberates the carbon. 

(e.) It is very combustible, and produces sulphurous and carbonic 
acid ; a little sulphur remains unbumt. Placed in oxygen gas or 

' StHnetlinei ■ fiule mllliy nnd ojisfgiia ■( firsi, but becomes limpid the not i'T- 



OMzcdoyGoOglc 



CARBONIC ACID. 36$ 

^utoxide of nitrogen, it renders it exptoaive. Soluble in volatile 
oilsj in ether and in alcohol, and predpitable by water. 
(yi) Evaporation from water causes it to congeal. 
- 3. CoypOBiTioir. — 85 sulphur to 15 carbon, and it is siq>posed to 
ccMatam 3 proportions of sulphur 16 X2=32 and 1 carbon 6=38 fix its 
chemical equivnlem. This c<MnpouDd was called alcohol of sulphur 
by Lampadius, its discoverer.* 

Hyvbo-xanthic acid. — (&n*f, yellow.) 

The aulphuret of carbon is generally unafibcted by adds, tnit the 
tutro-muriatic acid produces tiom it a yellow acid, whose nature is 
not yet exactly ascertained.f Its discoverer, M. Zeise, (Copenha- 
gen,) regards it as a compound of sulphur and carbon fw a base, 
vriih hyorogen ibr sji acidifier. It c<»nbiDes with alkalies, nentra>- 
izing them, and forming peculiar crystalUzable salts. The subject 
seems to need farther examinatioD.| 

Remark. — It was amHHinced last year, in Paris, that phosi^iorusT 
remiuning six or eight months in bi-sulphuret of carbon, attracted 
away the sulphur, and left the carbon to crystallize into true dia- 
incMid ; it was said that the Parisian jewellers pronounced it to be 
genuine, but the latest accounts state that the smaU crystals obtained 
appear to be ^ceous. 

CABBONIC ACID. 

1. CoxBnsTioN or cabboit in tabioits tobms. 

(a.) It has been already mentioned, that Sir Isaac NewtOD sup- 
posed the diamond to be a coagulated combustible, because it re- 
fracted light so power&Uy. This Baga<»ous conjecture has been con- 
firmed by the actual combustion of the diamond, and the products 
having been ccdlected are found to be carbonic acid.^ 



• CreU'i Annib, ITOS, II.— Cited by TniiMir. 

t Beneliiu mppoui It to ba ■ compound of murittic, carbonic and nilphoroua. 

•dd gtaet. 

t Ann. d« Chlm. et de Pbyt. Vol. XXI, iDd Ann. Phil. N. 8. Vol. IV. Thft- 
nard, Sth ed. Vol. I, p. 440. 

f The Emperor Frmcls I, exposed i quantity of dUnjooda and rubies to anintenAe 
hut, the rubies remained unaltered, but the diamonilg dinppoared. The Florendna 
academicians, by means of Ihe large burning glass o! Tschithaucen, la the prea- 
ence of Cosmo 111, Duhe of Tuicany, du«ipat«l several diamonds in the year 1GB4. 
TbeM experiments were repeated with equal succeu by l>Brcet, Bouelle, Macqucr, 
and other French chemists, who aseertalDed that the diunond was not merely dis- 
■ipalcd, but that it actually burnt with a vbtbla flame. Count do SterDb»rg, a 
Bohemian j^ntlemaa, fastened e diamond to red hot Iron, and plunged It into nygen 
gas, when Ihe combustion of Ihe iron set fire to the diamond, which burnt with a 
very brllllBDt flame. Lavoisier and Cadet proved Ihit Ihe diamond does not burn 
after the oxygen gaa la eihauited. But these experiments (rent only to prove that 
the diamond Is cambuatible. No attention hid been paid to the products of the 
csmbUBtion, until Lavoieier, tn 1777, undertook a aeries of experiments on a itirgo 
scale, to a«cert>lii tbli ptAnt. The result was tbund to be, that the dlaqioad whan 
burnt In oxjfen gas. Is converted wholly into carbonic acid gas, The conclusion 



D„tiidD,Googlc 



aM CARBONIC ACID. 

{b.\ A couid glass or porcehua tube filled with charcoal thu Iw 
been oeated till it has cetwd to yield soy gas, is placed across a &r- 
nace and ^ited ; one end being connected witb a gaaometer to lA 
lord oxygen gas or cominoo «r ; the other with a. pnaunat^ b[^- 
■tus to recaire the gas ; by adding Bnother gaiooaeter, the gas nuj 
be made to pass repeatedly back and forward. 

(c.) Diamond, charcoal, plumbago and anthracite, or any varietief 
of carbon may be treated in the same manner, as was dme by Messn. 
Atten aitd Pepys, in tbeir celebrated e^>enmeot9 ; they- used a jdi- 
tJDum tube to contain the diamond and other forma of caiboOt and 
their Eaxometera were placed ora mercuiy. 

Jii) Burn charcoal in a bottle or jar afott/gengoM ^ if a jMece(i 
I charred baric be used, tbe combustion is attended with brilliad 
aMitiHatiooa ; otherwise with only a bright ^w. 

(e.) .Bum any kind of wood, or a tmter, in a botU* ef eommn 
atTt or if oxygen gai, tmd earbonic acta will be formed, as may be 
evinced by the test of lime wat«', which producea a nnlky- precipe 
late. 

' {f.\ DioMond u ttttily made to bum tmdtr the cffmpovnd 6i«»- 
pipe, and wastes entirely away. If the combustioQ be 5to}^>ed in 
its progress, the sur&ce of the diam<Hid will be found, not caAoated, 
but indented and dull, as if it had been corroded and then washed. 
In my experiments it had tbe appearance of superficial fusitxi- 

(r.) An elegant apparatus fw the cconbustion of diamond, is fig' 
ured by Mr. Brande, in bis elements, and copied by Dr. Henry,t by 
which the diamcmd may be burned, and the products c<^ected. By 
combustion, it is rapidly diminished, and carixxuc acid is abundantly 
precipitated by admioing lime water. 

(A.) According to the experiments of different eminent cheni- 
istSiJ 28 or 29 grains of any pure carbon, require 71 or 72 ofoxy- 
gen and give 100 carbonic acid; 201 cubic inches of oxygen by 
buBc, rec|ture 28 or 29 grains of charcoal. Mr. Dalton assumes tbe 
compoiitvM tf carbonic add to be,^ in round numbers, 28 carbon to 

&t.t iliamoiid ti carboD, wa unavoidable. In IT35, GuytoQ Moireau, hoo^ ''"* 
the dUmond, when dropped into melted nitre, burns without any realiiuum, mil '"J 
muuier ■nKloeoiu to charcoiJ. Dr. TcDQant k1m> burnt tbe dUmonri in nltrBi •"'' 
found that urboDlc acid fis wu the onty pniducl.— (Phil. Tnna. 1797.) GujlW 
Morveau observed, that tha dfamond bums at three diSerent tempenluref , aM *!' 
tbough aoms of hi* concluilaiu were erroDeoun, for iuitanee, that the diaaiMxl ^ 
be converted into « gubalBDce reaemblln^ charcoal, and that charcoal it an oiide^ 
carbOQ, Btill he fully eitablished the &ct that diamoad Is by combuslioo, confcrlM 
into carbonic acid. 

> See Am. Jour. Vol. VI, p. S49. t Vol. I, p. B42, 10th Ed. 

t Carbon, 28.60; oxygen, Tl.«^=l DO. Carbon, 2T.ST6; o^fgen, 72.624=lM. 
Alien and Pepyi, Clement and DesarmeB, WollaMon, Gay-Ltuoac, and BeTU:^"'- 
See Henry, 10th Ed. Vol. I, p. 344. 

i He precUe propariiona appear to bo 71.12 of oxygen, and 27.37 of caitM- 
which correaponds with 3 praportlona oroxjgea and oT 1 carbon.— .WiUToy. 



DK;,lz=..,C00g[c 



CABBONIC ACm. 367 

"72 tuofgea, and all the resuhe oonifl ao near to thia, that we may 
venture to neglect the fraclioos. The compositioa of carbonic add 
is a problem of great Imporlance, for whenever it is produced, we 
infer the presence of carbon m the propoitioD now stated. 

(t.) Oxifgen f Of, fry uniting with charcoal, rufferi neither eontrao- 
tion nor expatuum, but increases in specific gravity, so that 100 
cubic inches weigh, at the medium temperature and pressure, 46.59 
grains, or about one and a half the weight of common air.* 

These methods of obtaining carbonic acid gas, are put in practic6 
only to demonstrate its composition ; they are never resorted to when 
the object is to oblab the gas in lai^e quantities ; then it is always 
extracted from some of its natural combioations. 

3. Other modes of obtainino cabbonic acid qas. 
(a.) Proaired from marbk pmoder, or chalk with dHute lulpkurie 
or muriatic add.f The proportioiis with sulphuric acid, may be 
about 6 parts by weight, of water, to 1 acid, and 1 ^ marble powder ; 
apfuratuE — 4 retort, ilssk, or battle, with a glass tube, bent twice at 
right angles, and turned up at the end of delivery ; it may be thrust 
dirough a cork bcved by a tapering hot iron ; the residuum will be 
sulphate of lime. 

(b,) Heat marble powder or ehaUc, red hot, m on iron bottle; a 
quart a^rds a barrel of gas, and the residuum is brought almost to 
the condition of quick lime. 
3. Decomposition. 

(a.) Decomposed by repeated electrical diacharget, over mercuty; 
becomes carbonous oxide, | and oxygen gas. 

The undeooraposed carbonic acid, being washed out by lime wa- 
ter, or potassa, and an electric dischai^e passed through the remain- 
der, it exj^des and becomes again carbonic acid. 

(6.) A mixture of hydrogen and carbonic acid, being heated in 
the same manner, water and oxide of carbon ere obtained. 

(c.) Carbonic acid, as it exists in the carbonate of lime, and of 
baiyta, and probably sirontia, is easily decomposed by ignidng die 
pulverized carbonate with iron filings, when oxide of carbon is pro- 
duced, as will be shewn in ctHmexion with that substance. 

(d.) Potassium heated in carbonic add gas, in the preportim of 
5 grains to 3 cubic inches, inflames, and charcoal is precipitated. || 



(■of diSerent wKtera, see Henry. 

t Huriitic acid, mtxed wllh 3 or 8 pirH of Rkler, ia perfaiM praferaU*, be- 
nnM Iha mlphatic add fertu tn inialuble eompouml witA tho Dma, ud clsgi tbe 
efterreBcence. 

t Whose propertea will be aoon eiplaitied. 

I I un iccuMomed M ezhlbii thia beiulUui expsrioieat by tlia fbllowiiig vruifa. . 
meat — A Uaik.witli dilute aulphuricRciil and mu-ble powder, bfitladiridi Kcarkeod 
tnbebeat twice at right uule*, through irhlch cartMBle acid guflomUthebottanof 
Mother fluh, and eipela Ihe air, or the fu may be introdDced to a rimllar mtoiiM' 



DK;,lz=..,C00g[c 



348 CARBONIC ACID. 

(e.) Carhonic acid, coDUiced in carlxHiBtfl of lime, or of soda, v 
deeampoted by pfuttphorut, and the carbon appears in the Sona tf' 
charcoal. 

(f.) It is done by taking a glass tube ^ of an incb wide, and SO 
incoes long ; it is sealed at one end, and coated ivith sand and claT, 
(o within an inch of the end ; phospbonis is placed there, and tm- 
ble powder, or better, carbonate of soda, dried in a sufficient beat; 
the part containing the carbonate is heated red hot, and then ite 
pbo^ihonis is sublimed through it, and the heat continued for some 
minutfls ; charcoal is found mixed with a phosphate.* 

(g.) In Dr. Pearson's experiment, 200 grains of phosphorus, and 
800 carbonate of soda, gave 40 grains charcoal. f 

(h.) If phosphorus be boiled in a solution of carbonate of soda, a 
becomes black in consequence of the developement of charcoal ; " 
is done in a small flask, and the process occupies an hour. 

4. PaopEBTiKa. 

(o.) Carbonic acid gat it fatal to animal Ufc ; if we confine a 
mouse or other small ammal in this gas, it will speedily die. But- 
terflies and other insects may be kHled in ifais manner, or by heU 
alone, without injuring their beau^. This gas kills both by suflbca- 
tion and by a'deadly influence of its own. 

ib.) It extinguvihea conAtution; lower a pendent candle mto it, 
withdrawing it immediately, drop it into oxygen gas ; it is nx' 
tinguisbed and relighted alternately. Gun powder bums in this gaS't 



trwa a imill gaxmoater. A tnt; of pUtlnam, with > lamp of pottmm-am, 1> '"ff*^ 

koto the fluk, takiDK cue U the nme tlma, not to let Id the tir or apUl the ew™- 

Ic uld ; k lube, twice beat *t right tuglet, li then idapled, uid dips Into * gw* 

eontiiDlDg mercuiy; lire cotila are ipplled beDBslh the tray of potwaium. mm 

jnat at the pojot of the fuiioD of plate glaia, the potaniuia ff% 

Inflimea with bright light, regenerated potasu GUi the 

Auk with white fumei, aiid charcoal prec[pit«te>, mil- t 

•d with the pDtinium. A green flaak would probably be ^p 

belter, aa eqdurlDB; mot« beat; ■omBtimei the experi- 

■MDt aurceedi with difficult]', and the bottom of the flaak 

k indented. N. B. The second tube and the mercury 

may be dlipenied with, provided we cork the flask ratn- ^ 

tr MMdj/, ao as to allow the gas te escape a little by ar 

■ Phii. Trani. I79I, p. 188. . , 

. t Phil. Trans. 1792, p. 288. ( . f 

t A, Large glaa* globe with a wide neck filled with J L 

carbonic add gas. -r-^"^ ~^ 

b. Iron er copper spoon with gnn powder in it. /^ \ 

C, An iraa rod heated red hot at the lower end to In- / ] 

Sum a ftw gnlas of gnnpowder. 

d. Orifice stopped with a cork, which being widi- i 
drawn, the gas runs In a vidble cnrrent and fluctustes. r, 

A csndle cannot bum in atmospheilca] air, coDti^nfnf 
Mie flMrdi part, by neanire, of carbonic acU. 



iKkJ 



CARBONIC ACID. S69. 

(c.) Mix smoke vtUh Uut gat, by exunguishing in il a burning chip 
or paper, or by burning a cork with a red hot iron borer, at the ve^ 
sel s mouth, or better by explodbg gun powder in a pendent spoon, 
in ajar, or globe fiUed with carbonic acia; seethe figure on p. 368. 
(a.) Tke gas it tkui rendered vitUile, and exhibits distinct fluc- 
tuations and currents. 

(e.) Butterflies and other insects of delicate cobrs are killed in tliis 
gas, and better than by sulphurous acid gas.* 

{^.) By a cylindrical jar, containing carbonic acid gas and a Utile 
water, with the aid of a pendent candle, we may show the phenome- 
na of the damp in wells and caverns. In the annexed apparatus, two 
ounces of the carbonate of am- 
monia, and half as much deep 
orange colored nitrous acid, being 
placed in the three necked bottle, 
will evolve carbonic acid gas, 
which will thus be rendered visi- 
ble in its ascent, and in its over- 
flow beneath the cover of the up- 
per vessel. This bemg removed 
and a candle introduced, it will 
be extinguished. The gas can 
be drawn off at A ; its current 
win be visible, and it will extin- 
guish a buniing taper held in its 
course ; or it can be drawn like 
a liquid into any other vessel con- 
tainmg a Ughted candle which it 
will thus put out. If either ori- 
fice of the botde be opened, all 
the gas in the upper vessel will 
flow out — Dr. Hare. A lone 
necked fiinnel may be substituted 
for the upper vessel. I 

(g.) Sp.gr. 1.527; lOOcub.ii „ i. 

Bar. 46.59, whereas air weighs 30.50.f 

(A.) We may pow tke eoatents ofonejar into another, and exa- 
mine by a pendent candle how h^h the gases rise. 

(i.) We may collect it by a bent tvhe passbg into a bottle filled 
only vritb coimnon air, which it will expel. 

* EntomologlMt m&r to kill them simply by meuii of heit, immeriin^ ihem in 
boUlug wftter, in ckiM tssssIi. 

t It U uld thit Dr. Praut hu recently ucertaiiied Hut il ii u high at IcMt u SI 
ni. Addenda In Turner, 3d edition. 

47 



OMzcdoyGoOglc 



370 CARBONIC ACID. 

(_;.) The absorption of this gat by ioater, is tlote if merely sund- 
ing over it, but rapid, if agitated witti the water in a bottle. 

(k.) JVooth't apparatus is an elegant one for impregnating waio 
wiui tnis gas ; it combines agitation and moderate pressure. 

A, The pedestal aod containing vessel for the 
marble powder and acid ; a, an orifice for pouring 
in the diluted acid which should be mixed previ- 
ou^ with water and allowed to cool, 

B, The neck of the vessel to contain the water 
which is to be impregnated ; this neck contains a 
Klass cylinder pierced longitudinally with capillary 
ducts, and also n plano-convex lens, which oper- 
ates as a valve. 

D, Tlie containing vessel furnished with a stop 
cock at C. 

E, A vessel of retreat for the water. As the 
gas rises into the middle vessel, it causes the 6u!d, 
by means of the bent tube e, to mount into £, thus 
producing hydrostatic pressure, and favoring the - 
combination of the water with the gas. ** 

Much more powerful instruments are known i 
the arts.* The foUowing is from Dr. Hare. 

IHPREGNATION OF WATER WITH 




" A condenser. A, is fastened at bottom, into a block of brass, 
i^ch is furnished ivith a conical brass screw, by means of whicii, n 

•PMLTraos. 1S03; Dr. Ncniy's Ap|iara(u». 



CAEBONIC ACID. 371 

is easily attached firmjy to the floor. In this brass block are canties 
for the two valves, one opening inwards from the pipe, B, the other 
outwards, towards the pipe, C. The pipe, B, conuDunicates with a 
reservoir of gas which the condenser draws in, and forces through 
the other pipe into a strong copper vessel containing the water. The 
front part is represented as removed in order to expose the inside to 
inspection." 

" If due care be taken to expel all the air in the vessel before the 
impregnation is commenced, the water will take up as many tiroes its 
bulk <» gas, ss the pressure employed exceeds that of the atmo^here." 
" When duly saturated, the water may be withdrawn at pleasure, 
by means of the syphon, D, of which one leg descends from the 
vertex of the vessel, to the bottom, while the other is convenienlly 
situated for 611ing a goblet." 

(l.) The gas washed to free it from any sulphuric scid, and passed 
up bto litmus infusion, reddens it fugaciously. 

(m.) lAqaid* carbonic add gitu up itt gat &y boUmg, and by 
beii^ placed under the exhausted receiver. 

(n.) Liimui water, reddened by this acid, it reitored hy air pump 
exhauttion, or by botUng.-f This gas is liberated from water by 
freemg, which gives the fluid a spongy appearance. 

(o.) Lame water it a tett of carbonic acid; it is applied by pour- 
ing the Uqutd acid into it — by sufiering the gas to pass into a tall in- 
verted tube closed at ihe top and filled with lime water, or by ta' 
ceiving the gas in a bottle and washing it with lime water. 

(pj) An exceti of carbonic acid redittolvet the prec^niate, and 
then more time water precipitates it again, and so on without limit* 
(9.) Burn a candle, a stick, 01 any common combustible, in a bot- 
tle of air or oxygen gas, and examine by lime water for carixxuc 
acid ; if present there will be a milky precipitate. 

(r.) Carbon it a principle of ikote tvbttancet which, by bvmiHg, 
gwe a gat not rapicUy abtorbed by water, and which predpitaia lime 
water; the precipitate beiiig lolvhle in muriatic add, with effervetcenee. 
(*.) TTiu gat it an antiteptic, and therefore useful in putrid dis- 
eases, and externally in ulcers. Cataplasms are made with yeaat 
and other fermenting materials. 

{t.) Meat suspended in carbonic acid, especially if the gaa be 
frequently renewed, keeps much longer than in common air. 

(u.) Carbonic add promottt vegttation, especially when in the 
liquid form and applied to the roots ; also, as an atmosphere, [«o- 

* At > commoQ lempenture utd prenurc, water ibsorb* lu oitd volume of gu ; 
IwicB iU volurae under a double pressure, nnd M on in ths same ratio. 

1 Tincture of aUcaoct diluted md ili^htly blued b; immoDla, is decidedly redden. 
edwhcDagiteled inavral witli carbomc acid giu. 

WheD Ibe above tolutioQ \s boiled so ai lo expel the Mrbonie acid, it rwunei ft* 
ari|;iDa] blue color. 



OMzcdoyGoOglc 



$79 CASBONIC ACID. 

vided it does not exceed one etghdi of the vbole ; beyond that il e 
injurious. 

(v.) 7^ gtu exitU infermenitd liqmdi ; we may collect it from 
aay fermeDtbg mixture, or irom bottled cider, beer, porter, &c. aod 
it nrill prove to be carbonic acid. 

(w.) Thit OMjy be ihaim by drawitig the cork under tooAsr — ibe 
mouth of the botde being immersed, me gas, at least what is spoo- 
taoeously disengaged, wiU collect at top, and die rest miy be obtain- 
ed by boiling the fluid in a proper gas apparatus. 

6. MlSCBLLANEODS. 

(a.) Cariouic acid gat, on account of its gravi^, if o/ten Jomid 
ul the bottom of (m/Z* and tmtmu, as in the grotto Del Cani, near 
Nicies, and thus often destroys those vfoa incautiously descend into 
ibein ; by letting down a candle, it may always be determined 
whether the place is safe. 

(i.) A» the combutlion of charcoal, and other carbonaceous sub- 
stances, elioayi generatet carbonic acid, it it untile ever to renoM 
in a confined situation, in luch an atmoiphere ; in both these modes 
many lives are destroyed. When i[ is pure. It produces a spasm of 
the glottis, and sufibcation ensues ; if so much diluted as to pass in- 
to the lu£g9i it operates as a narcotic poison.* 

(c.) 7%ere are mam/ other gatet evolved in combvttion, and oil 
of them are deadly ; nitrogen is always present in such cases, and 
frequently carburetted hydn^en, gaseous oxide of cartxxi, anunoma, 
and various -npon, as-otpyroligneous actd, be. 

[d.) Fire thould, thergore, oluxiy* he made wader a good dratmig 
vent. 

(e.) Carionic add it eminently laitUary in the ttomach, although 
fatal in the lungt ; witness the native and artificial acidulous waters ; 
its action in tbe primie vin is that of a mild stimulant. Widi com- 
tnon air, it exists, dissolved, in all natural waters, and imparts to 
them pungency ; hence the flatness of boiled water, or of that tiUeb 
bas been exposed to air pump exhaustion. 

(/.) Carbonic add gat it tht prindptd agent in raitittg bread f 
it b generated in tbe fermenting mixtures, as yeast, the sedimeDl of 
beer,t kc., and the native or artlfida] acidulous waters wiH inflate 
dough and make it li^t. 

Q.) Carbomc acid exittt every latere in the atmuphere ,- it wu 
found on the top of Mount Blanc, by Saus8ure,| and aeronauts 
have brought it down lr(Mn tbe greatest heights to which man his a>- 

* It ti tuppOMd bv many, that clureo*], wAfn homing withMil mote, i> hirni- 
let*, uid Om file tnthrtdbi coat doai not praduce ■ noiloni gu ; belli theM >rg rery 
duiKsroin popular error* ; U)« deadly carbonic acid gu li rapidly iorawd btm UA, 
Airmg tJttnAole timt that they are bxaniiig. 

t Called In thl« coantry emplyir^. t four, de Phyi. XTII, p. DR. 



OMzcdoyGoOglc 



CARBONIC ACID. 373 

cended ; in general, the |>roportion is very uniform. A pellicle is 
Ibrmed on lime water, by exposure to the air ; it contains jij carbo- 
nic acid, as fimnerly suted ; according to Dalton, ttwi or even less. 
(A.) Although produced in eDormous quandties by respiration, 
coinbusdon,'and oUier processes, it is scarcely found lo exist m great- 
er propordon in large towns than in the country ; doubtless the winds 
Erevent its accumulation. At sea, however, only two leagues from 
Meppe, there was so htde that it scarcely ai^ted barytic water.* 
(«.) Caustic alkalies absorb carbonic add gaa entirely, and tfatm 
separate it from other gases. 

(j.) Vegetation appeart to be the grand meant of pmerving the 
^rUy of the atmotphere ; it decomposes the cartxHiic acid, absorbs 
Its carbffli for food, and lets loose its oxygen. 

It is true that vegetables emit carbonic acid in the niglu, but in 
smaller quantity than that which they decompose in the day.f 

{k.) Carbonic add u vinbk in the tunthtne, as it descends into 8 
vessel of common air, because, on account of its great weight, it produ- 
ces onequal refraction in the light, and thus creates a disturbed image. 
6. Rbbpikation. 

(a.) About 8 or 8)- per cent, of carbonic acid is dirown from the 
human lungs in respiration, at every expiration, and cHily 10 per 
cent, when the contact is rendered almost as frequendy as possible ; 
a arailar result happens with the whole animal creadon. 

(b.) About 11 oz. Troy, of carbon, are thus daily detached frran 
the blood, and of course more than twice the we^t of a tiving man 
in a year. 

(e.\ Thus one great office of respiradon is, the decarbonizatioa of 
Ibe blood. 

(d.) The production of animal heat it tdto intimatdy etmneeted 
with ttut proceu ; venous blood becomes arterial in the lungs, and 
there acquires its florid color, and emits its excess of carbon, and its 
capacity for heat, according to the experiments of Dr. Crawford,| is 
enlarged from .892, which expresses the capacity of venous blood, 
to .1030; thus the heat that would be evolved from the union of the 
GfiiboD with the oxygen, is absorbed, and sgun given out when the 
arterial blood becomes venous, that is, all over the body.[| 

(e.) There can be no doubt that animal heat is connected also with 
the nervous power, with se(»«ti(Hi,and perhapswith other vital t^encies. 

■ Ann. Phil. N. S. TI, p. TB. t Sea Thomwa's Chemlitry. 

X Ttie experimenU of Dr. J. DiTy, do M( •pp«*r ta hire let aide Ibosa of t>r. 
Cnwford. 

Q In * Dota im reif irtUoa, in Puku' Oiem. Clwt the Cdloiriiig ticti >rs ititad. 
Tba hacDUi heart pvtn 100,000 itnAaa to 24 honrt, 4000 MrDkei in \a hour, uid 
W or 8T la ■ minute, ind SM pooada of hlood pui tbrougfa It in dnt time \ H 
^ndiiilbewholeunanat la thebodyof a comioaa ^zcd sua ; thii piMni thnnufa 
the hurt 14 tloief ia aa hour. The aorta of a whale ie one loot in diameter, uidlO 
or IS galloat of blood (half a barrel,) «re leotout at every atroke with raK force. 



OMzcdoyGoOglc 



374 CABBONIC ACID. 

f /.) Lime or barytic water is precipitated by blowing througbi 
wita s tube ; or by agitation in air which has been breathed. 

7. Combining weight. — The weight of carbon is 6, and carbonic 
add being a compound of 3 proportions of oxygen, and I of carbon, 
its equivalent wiU be 16-|-6=32. 

In volumes, Gay-Lussac estimates it constitution to be 1 gaseous 
carbc»i, and 1 oxygen, condensed into 1 volume. As oxygen u^de^ 
goes no change of volume, by combining with carbon, and as 100 cu- 
bic inches of carbonic acid weigh 46.597 grains, it follows that (be 
amount of carbon in vapor will be 46.597 — 33.888, the weight of 
100 cubic inches of oxygen, =12.709 grs. of carbon ; and as 12. 709 
: 33.886 : : 6 to 16, and 6 bemg the combming proportion of cir- 
bon, it follows that carbonic acid is composed as above. * 

8. PoLAEiTY. — Like other acids, it is evolved at the positive pol^ 
and is therefore eUctro negative. 

9. LiQUErACTioir or cabbonic acid. 

Ji^. Faraday\ effected tkU by cold and prettvre. He contrived 
to extricate the carbonic acid gas from sulphuric acid and carixnale 
of ammonia, brought together at the moment, and after the bent glass 
tube in which they were contained was sealed, the other end of the 
tube was kept cold by a freezing mixture, and the gas, suWected to 
its own enormous pressure, aided by cold, became fluid. Iliese ex- 
periments are very hazardous, as it is a more difficult gas to con- 
dense than any with which Mr. Faraday succeeded ; very strong 
tubes were required and yet they often exploded. 

10. Pboferties. 

(a.) Limpid, cohrUn, very fluid ; floating on the other fluids io 
the tube ; distils readily and rapidly between and 32° ; re&aC''* 
power lass than that of water, not altered by increase of cold. 

When it was attempted to open the tubes, they always burst wil>> 
powerful exploMons ; at 32° the pressure was equal to 36 atmos- 
pheres. 

Sir H. Davy, m a comraunication to the Royal Society, su^ested 
tlie applicaQon of condensed gases as a movmg force, capable of be- 
ing increased or diminished by slight variations of temperature, u 
would be necessary only to let loose a little of the condensed carbonic 
acid, to produce a powerful movement ; condensed nitn^n wouW 
be still more powerful, and hydrogen would exert a tremendous force. 
No furnaces would be necessary, but mere variadons between sun- 
shine and shade might perhaps be sufficient to vary the energy of oK 
power. It is obvious, however, that the danger of expk>si<»i would 
be great. 

11. Discovert. — ^Dr. Black discovered carbonic acid in 1766,(W 
6, and thus laid the foundations of the pneumatic chemistry; heoaUw 

* Turner. 1 Phil. Truu. 1SI8, p. 19S. 



OMzcdoyGoOglc 



CARBONATES. 375 

ityixeiair.* Its composition was first demonstrated in 1773, by 
iJELvoisier, who, as already stated, proved that the diamond, by being 
burned, becomes carbonic acid gag. 

13. NaTDBAL ORICIN. 

Carbonic acid gas is formed abundantly by the re^taliOD of ani- 
inals; from our candles and tumps, and from our fire-places, and 
from furnaces, from fermentation and putrefaction it is peqjeiually 
rising into the ur. It forma nearly half, yVin "f the beds and moun- 
tains of marble and limestone, and exists in various other natural car- 
bonates, and abundantly in shells. Its fatal prevalence appears to be 
prevented by the fact that vegetables during their growth decompose 
this gas, absorbing its carbon for food, and liberating the oxygen to 
recruit the waste of the atmosphere. 

The late Dr. Woodhouse, proved by many experiments, that when- 
ever vegetables emit oxygen gas, it is from the decomposition of car- 
bonic acid present in the air, and dissolved in the waters which they 
imbibe. He justly rejected the idea that they give out oxygen gas 
of themselves, or from the decomposition of water.f 
13. Meoical akd economical uses. 

It is highly salutary in the brisk and acidulous natural mineral wa- 
ters, such as those of Saratoga and Ballston, and in imitadons of them 
by art, either with or without saline substances ; in fermented li- 
quors, to which this agent imparts life and pungency, and in a de- 
gree to all natural waters. It operates as a tonic, diuretic' and an- 
tiseptic remedy. It is said to be very useful in the hemorrhoids or 
piles ; it is a reagent in tlie laboratory. 

CARBOITATES. 

Beneral facts and charaetert. 

Some of them have been long known, and were used before the 
discovery of the power of carbonic acid to neutralize the alkalies. 

(a.) The carbonates efiervesce with acids, and emit cariionic acid. 

(&.) Tfaev are decomposed by heat, more or less violent ; the gas 
being expelled, and the base remains.^ Potassa, soda and lithia, 
are excepdons. 

(c.) Aikaline carbonates turn the vegetable blues green, and have 
an alkaline taste. 

(d.) They are soluble in water, and the carbonates of the alkaline 
eaitlis become so by an excess of carbonic acid. 

* The miDGn, illucliag to its elTecl on regpiriLion, c>11 it choke damp, 

I See 2il votumcof Nicholson 'i Journal, Svo. and ao atulracl in Meaw'i Domeidc 

t Charcoal ii addid lo some of the carbonalei before ienilion, uiil alda in produ- 
cing the effect; nmeiiiDas by decompmiDg the carbonic ickt ittelf. Baryta md 
fdontia are uiuilly managed in this manner. 



OMzcdoyGoOglc 



37G '^ CABBONATES. 

(e.) They umuin olber one equivalent of acid to one of b»x, 
and are then called carbamates ; or two of acid to one c^ baae, aol 
are (hen called bi-carbonates. 

(/I) Host of the carbonates exist native, and all may be (anoti 
by pasdi^ carbonic acid gas through the \ase, suspended or dissdv- 
ed in water. 

CA&BOMATE AND BI-CABSONA.TK OF POTiSSA.* CABBOITATE. 

1. Name Aim Histobt. 

(a.) laibe shops ciiiei lalt of tartar, lalt (^ wormwood and peaii- 

(6.^ TTte carboitaie of potatta vxu alwajf$ contidered at the put 
imdU, till Dr. Black discovered the error.f 

(c.) Tht alkalKi at found in the tkopt, under the namet ofpeaii- 
amUf ud toda and vouttUe alkali, have been called sub-cariwoaie^ 
and when saturated with carbtMiic acid they were called carbonates 
As it b ascertained that in the former state they connst of one equir- 
alent of alkali and one of base, and in the latter of two equivaJentE 
of acid and one of base, the last is now called bi-carbooate and the 
Gm simply carbonate. 

3. Phepakation. — For commoD purposes there is no occasion to 
prepare this sah artificially, but for instructioQ or to attain greater 
pun^, it mav be dme, 

(a.) Btf a^fiagrating tartar with one eighth of pare niire. 

(J.) Tartar may be calcined in a cracUHe, which destroys the tar- 
taric acid ; lixiviatiffli and evapwation g^ve about one tturd part of 
dry carbonate. 

(c.) JVt(re being mixed tnth one fourth of dry potvdered diartooi, 
ana thrown into a red hot cnicSde, both acids are destroy-ed, end tbe 
alkali obtained amounts to rather less than one half of the nitre em- 
ployed.! The alkali obtained from tartar may be made to crysoi- 
lize, and the crystals contain carbonic acid 32, 1 proportion ; potassa 
46, 1 pr«X)ction; water 18, 2 proportions, =88, the equivalent. 

(d.) Cauttie potath abtorbt carbonic add gat with avidity, and 
when saturated, and evaporated to dryness, it tornis the carlmais w 
potash, containing, accmding to an average of three analyses, car- 

* For the Dttural hiitory of the orbooate, mo potun. la vegetibleii It 1> P*^ 
■Uy eoiDbiiiBd, for the pvater part, with idoa, which bcliig destroyed bj w 
fire, MTbonic acid u thus bnoed and uoltai to the alkali. 

t It hai been alreiidy aeolloned that the old chemical booki deecrlbe eOern*- 
c«i>ce widi adds, a« a teit of alkiUee; whereat tbii property belonn to (bur 
Dr. Black fint proved that Ibli i> Ibeh- eonuMn itite, that the c"^^ 



acid eeuHj allay* dMir aciiitiaoy, utd that they are cMtitlc only wfaeo deprived of |t- 

t A liltlatalplMla and muriate of potana, and a Uttle lUici, r " 

tbe alkali thai prepared, and H it dlSicuh to remore tbem. 



DK;,lz=..,C00g[c 



CAROBNATES. 



377 



bonic acid 3t.50, alkali 68.63. The ignited carbonate contains no 
water, but there is ic commoD salt of tartar from twelve to sixteen per 
cent. 

3. Prop K AT IKS. 

(a.) As it occurs in the shops, it is never cfystallized ; the pearl- 
ashes are always a white porous mass ; the potashes are firm, and of 
a grey, reddish, or dark color, and both are impure, being mixed, 
usually with silica and difierent salts, as the muriate and sulphate of 
potassa. 

(6.) Very ddiqueacent, and in the air, becomes in a few hours, 
serai-fluid. 

(c.) Givei carbonic acid gas by other acids and hy heat; alka- 
line to the taste, turns blue vegetables green, and is even somewhat 
acrimonious, but does not destroy ike texture of woolen doth. 

{d.) Does not absorb carbonic ^cid from the air, nor yield any- 
thing to alcohol. 

(e.) Soluble in le^ than 1 part of cold icater, and cannot be freed 
from It without considerable heat. 

(f.) Taste much milder than that of the caustic aUudtet. 
4. Metbods of determining the quantity of seal alkali.' 
(o.) Potassa preapitates alumina Jrom alum, which its impurities 
will not do ; hence, the quantity of earth thus precipitated, indicate;^ 
the proportion of alkali. 

(p.) By nitric add, which does not dissolve the hnpurities of the 
salt.* 

(c.J The proportion of carbonic acid indicate* the proportion of 
aUadt. — In a balance, place in one scale the alkali and diluted sul- 
phuric acid, in different vessels ; counterpoise them ; then add the 
acid to the alkali ; the loss of weight is carlxHiic acid, and impties 
about twice as much alkali. 

(d.) The solubility in water is a tolcrahle criterion. — Most of the 
impurities, especially sulphate of potassa and silica, being insoluble. 





1 


ii 


II 


il 




^ 


Pb(«hofftii«ia, .... 

Americui Peorlub, . . - - 
Potash Of Trevas. 

Dantdc, .... 
.. Vo^Ke., - - - 


772 
«67 
7M 
T20 
608 
444 


80 
165 
152 
148 


4^ 
14 

51U 


2 
6 
24 

79 
21 


808 
199 

804 
304 


1162 
1152 
1152 
1IS2 
1«0 


luoted front Ann. de Chim. XI, 2»S. 


^Qt. or pure alkali.— IhoiuoDl 



D„tiid-j,Googlc 



378 CARBONATES. 

or difficultly soluble, the proportion of re»duum, tlierefore, indicaies 
the amount of impurities. If the impurities are soluble, as muriBte 
of soda, then the sulphuric acid becomes a test ; 355 graina of tkit 
acid of the sp, gr. 1.141, (which is the best for this purpose,) tatn- 
rate 100 graiiu of carboruUe ofpotassa. Dissolve this in water, add 
the diluted acid by degrees, till the alkali is Deutralized^ and wei^ 
the remaining acid ; then as 355 : 100 : : the acid expended lo the 
proportion of alkali.* 

bi-cailbonate of potassa. 

1. Preparation. 

(a.) In JfoolKt, or a timilar mocAtne, pa»t carbonic acid gia, 
to saturation, throt^h a tolution ofpotasaa, or of the carbonate in 5 

Starts of water. The bi-carbonate crystaUizes as the process goes 
brward, or afterwards by gende evaporation. 

(b.) Or, we may take 1-f- part of carbonate of ammonia, andi 
af the carbonate oj potaua, and dissolve in 4 of water ; distil with a 
gentle heat in a retort ; ammonia is found in the water of the re- 
ceiver, and bi-carbonate of potassa in the retort, without any loss of 
materuls.| 

(c.) By exponme potaua, or itt carbonate, in the vait of the brev- 
er, or of the dittiueT, we can obtain thecrystalUzed bi-carbonate. 

3. Properties. 

(a.) CryttaUixes in tablet, or quadriiateral priamt, and is termi- 
nated bypyramids. 

(&.) Tiute, slightly alkaline, but not catutic ; mild in the ttonach, 
not deliquescent. 

(c.) Sometmea effiorescent.^ — Sp. gr. 3.012. 

(d.) Soluble at G(P, in about 4 parta of cold uiater, and in about 
5 at 212°. The strongest permanent solution at common tempe- 
rature, has the sp. gr. 1.54, and contains 48.81, of carbonate. 

(e.) BoUifig hot water expelt bi^bla of gas, amounting to f', of 
its weight. A boiling heat u therefore nffictent partly to decorate 
the lalt. 

) Deerepitaiet and melts wkh a gentle heat, loses its water, 
B red heat expels just half its carbonic acid, leaving it a pure 
carbonate. 

3. Proportion of principles. — ^It contains twice as much car- 
bonic acid as the carbonate ; proved by the quandty of gas given 
out from each by the action of acids. 

• Henry, lOtii Ed. Vol. 1, p. B44. 

t To 1 lb. ofiub-carboDateorpoluh.ln Kitut]oD,add2or8cn.Drcarbonalanfim- 
liionn. uid dutil.— J?r. Hirpe. 

! During the uturatioa of ciuuinan pot or pearluh, with carbonic acid, nliei ii 
ttways deposited. 

i Four. Vol. IV, p. 41. 



ind are 



OMzcdoyGoOglc 



CARBONATES. 379 

Acid, 43.9,+ base, 47.1,+ water, 9.0=100. — 2 prop, carbonic 
acid, 44+ 1 potassa, 48,+ 1 water, 9=101 for its equivalent. 

4. Action of preceding bodies. 

^a.) The action of sulphur and of the acids, has been already ex- 
plained. 

(i.) Decomposed by baryta, ttrentia, and lime, and an earthy car- 
bonate is precipitated. 

fc.) Suiea and abimina, by ignition, expel the acid, and unite 
^th the alkali, as before stated under the manufacture of glass. 

(d.) In the humid way, decomposes the nitrate and muriate of 
baryta, and in the dry way, the sulphate. (See that salt-) 

5. Uses or the cabbonates of potassa. 
Numerous in the arts. — See potassa. 

In medicine, emfhyed as an antacid and lithontriptic, of unAoahted 
efficacy ; the bi-carbonate in good crystals should be preferred ; it 
is flissolved in water, or in any mild fluid. When the solution is 
swallowed, the gas is often disengaged by acid in the stomach, or by 
some mild vemable acid, taken for the purpose. 

The crystfus are often taken, a tea-spoonful at once, or in doses 
of 1 5 to 20 grains, and they operate actively as a diuretic, especially 
if the soluuon is considerably diluted. The term super-car Donate, 
formerly applied to this salt, is incorrect. Dr. Coxe justly remarks, 
that there can be no super-carbonate, except when the solution is 
lu^ly charged with carbonic acid gas, by pressure and cold. 

The bi-carbonate is one of the most elegant of the antacid reme- 
dies ; it should be in every family, being perfectly safe and useful 
in cases of disordered digestion. With the vegetable acids, especial- 
ly the tartaric, or citric, it forms a fine effervescing mixture. 
cabbonate amd bl-cakbonate of soda, 
carbonate. 
1. Nat(jbal History and Okioin. 
(a.\ Obtained by incineration of marine plants, &c.* 
{b.) In commerce, the impure soda, or carbonate of soda, is call- 
ed barilla, or kelp; it contama, besides this salt, sulphate, muriate, 
and sulpburet of soda, sulphuret of lime, usually hydriodate of pot- 
assa, and much earthy and carbonaceous matter. 



tr Tripoli, and from Ihe decompcwidaD 

dimp mllf, generaliy on Euch u cooiist in pari tyf 

HnM and lea nnd, the cirboiiate of lime uid the murJite of lods mutually decom- 
poahicaach other. 



OMzcdoyGoOglc 



380 CARBONATES. 

3. Names. — TTie jntre of the ler^turei is the carbonate of 9oda.* 
Anciently nttnim or natron, and at Trip(^, called TVona. 

3. Preparation. 

(a.) Carbonate of soda of the shops, may be pvrijiedby disMoJrijig 
•t m ^ or i of its weight of water.-f 

(b.) Effloresced carbonate of soda is the pnrett, as it thus sepa- 
rates from other salts. 

(e.) The soluUoR is to be evaporated at a Urn heat, and the crys- 
taU m muriate of soda skimmed off, till they cease to be produced, 
and then the solution may be su&red to crystallize by cooliiig.]; 

4. Properties. 

(a.; The crystals are decahedra, ccnnposed of two quadrilateral 
pyramids, united at the bases, and truncated at their apices ; the pii- 
maiy is an oblique rhombic prism. 

(6.) Taste is aVcaiine but not caustic; turns blue v^etable colors 
green. 

(c) Specific gravity 1.3591. 

[d.) Soluble tn 2 parts of water at 6(P, and in stHoenhat less than 
1 part at 313°. A^ the solution cools it deposits crystals. The 
strongest permaneot solution, at comnMa temperature, h^ the specific 
gravih^ t.26. 

(e.) The bi-carbonate ofpotassa is scarcely altered by the air; tie 
eanonate deliquesces, but the carbonate of soda, on account of its 
large quantlrvof water of crystallizauon, (62.69 per cent.) effloresces 
rapidly and falls into powder. 

(f.) By being again dissolved in water, it crystallizes anew. 

(^.] Readily suffers the aqueous, and by ignition, the real igneous 
fusion. 

(h.) By a very violent heat most of its carbonic aixd is exp^ed, 
but not the whole. 

5. Proportion or its prikcipi.es. 

(a.) By the action of a known and a sufficient weight of sulphuric 
acid, the quantity of carbonic acid is determined, and this acUon join- 
ed with the e&cis of heat, has given the following for its composi- 
tion. Acid 13.98, bBse33.33,water63.6d=I00.00, and omitdog 
the water, 

Acid, - - 41 .33 or 1 proportion =22 

Soda, - - - 58.77 or 1 " =32 

100.00 M and the ciystala of 



• Se« p. 251, {Sodfc) I Four. Vtd. IV, p. 01. 

t The cilcined acetate, diuolved ami filtered, and the bi-carbonale healed io Ibt 

me manner, allbrd a pure cirbonlle. 



D„tiidD,Googlc 



CARBONATES. 38| 

Carbonate of soda, 37.5or 1 proportion <=:54 
Water, - - 62.6 or 10 « =90 

100. 144 

(&.) lOO grains anhydrous carbonate neutralize 460 of sulpfaurie 
acid, denaty 1.141 ; dierefore supponng no oilier alkali present, as 
460 to the acid required to saturate 100 grains of any sample of car- 
bonate of Boda, : : 100 to the quantity of anhydrous carbonate.* 
6. Action on preceding bodics. 

(a.) All that vas said under the preceding article is tme of this, 
and need not be repeated. 

(6.) PotoMia dee&mpoaea tktt talt and renders th£ »oda eotuftc, just 
as the alkaline earths act upon the carbonate of potaAga. 

(c.) Carbonate of soda, like carbonate of potasss, by douUe elec- 
tive attraction, decomposes many salts, even sulphate of baryta, by 
ignidon. 
7. Uses. 

(a.) Very valuable in the aria; in the manufaeture of glass, es- 
pecially of the finer kinds, which it renders more fusible ; of hard 
aoap ; in dying ; and as a detergent in washing and in bleaching ; but 
for the two latter uses it must be rendered causae. 

(6.) In soda water it is now extentiveJ^ Vited as an antadd and 
UthontripHc, fyc, aod as an agreeable beverage. The watery solu- 
tion of the salt is supersaturated with corbonic acid. It is prepared 
in an iron bound barret or a strong copper vessel lined with tin, hir- 
nished with means of internal agitaUon ; the gas is injected by means 
of a forcing pump ; four or five volumes of the gas are thUs condensed 
into one of water. Proportion of alkali, two ounces to ten pounds of 
water, or from two and a half to three pounds, for a barrel. 

SEHARKS ON SODA WATBB. 

Having been concerned in the introducticm of soda water, into this 
country,f and hftving been much conversant with its manufacture 
and use, I may be permitted to observ©— 

(a.) That if properly prepared, soda water it a very vdlltMble 
thing. — ^To this end, the full proportion of soda should be dissolved 
in the water, and widi the aid of cold, agitation and pressure, it 
idtould be made to absorb carbonic acid as much as possible. This 
will depend upon the strength of the machinery, and upon the well 
known law, that if, as is the case with the carbonic acid gss, water, 
at the common atmospheric pressure, absorbs an equal volume ; with 
a double pressure it will absorb two volumes, with a pressure acain 
doubted, the absorption will again be doubled, diat is, it will be four 
times the first, and so on. 

■ Heory, Vol. I, p. G65. 10th ed. I March, 180T. 



OMzcdoyGoOglc 



383 CARBONATES, 

Jb.) Wttitr mpreenated tmtA aabonic acid merely, is erroneoti^ 
td toda water; it 19 a pleasant brisk acidulous 4nak, and to a de- 
gree useful, but it will not remove acidin; it will act feebly in cor- 
rectiiig the alimeatuy ciinal, and it will nave only partial activity is 
a diuretic and lithontriptic. 

Jc.) If the water containt onlj/ a ItttU carbonate of eoda, it mil 
fall far short of the qualities of genuine soda water. 

(d.) It it not tufficient to add the tolvfion of the talt at the time, 
and to draw the water impregnated with carbonic acid upon it ; this 
will indeed be more useful than the water named at (&) &u:. but i 
will be, comparativelv vapid, because the alkali attrac^ avray the 
free carbonic acid, winch gives briskness to the water, and the saiur- 
uion which ought to have been fuUy made in the machine, is v^ 
imperfectly made in the drinking glass. 

\e.) The genuine toda water, with the fvU charge of alkali and 
gat, u an excellent antaeid, diuretic, lithontriptic and anti-dyrp^tie 
remedy ; but much that it called toda waier, pottettet thete pr^fer- 
tiet only in a very aaaU degree. 

(/.) Soda loater may Be uted too freely. — Lai^ quasuties of 
water may weaken the digestion, and produce injury also by the cold ; 
and where the diuretic efiect b needed, it is better to repeat the 
drinking at convenient intervals. 

(g.) Cordials and tyrups mixed with the toda water, greatly im- 
pair or destroy its salutary effects, and may lead to other bad results. 

BI-CASBONATE OF SODA. 
1. PREPARATIOH. 

(a.) The tatnrated tolution just described, or a sinailar sotuticHi 
impregnated to saturation in any other way, will, when gently evapo- 
rated without heat, afford confuted crystals of bi-carbonate. 

ib.) Or 100 parts of the soluliDn of common carbonate, mised 
1 14 of carbonate of ammonia, distilled, evaporated and cryscalliz* 
ed, as in the case of carbonate of potassa, will produce the salt. 

(c.) Expotta-e of the carbonate, m a brewer't or dittUler's vat, to 
the action of carbonic acid gas, wiS ^ontaneouily effect (he eom- 
binaUon. 

3. Pbopebtizs. 

(a.) Tattenuld; at 60° soluble in 9 or 10 parts of water. 

(b.\ Gentle heat expeb part of the gas and it escapes in a vacuum. 

(c.\ Affeett the test colors, as the sub-carbonate. 

(d.) 100 grains, at low ignition, lose 37.4, and 62.6 remiin of 
diy anhydrous carbonate. 

(e.) ConstitutioD — carb. acid, 67.9 or 3 pro. 44 
soda, 42.1 or 1 " ^ 

100. 76 its equivalent. 



OMzcdoyGoOglc 



CARBONATES. 383 

If crystallized, 2 proportions of water, 18, will make the equivalent, 
94. 

The trona of Africa is said to be a sesqui-carbonate,* that is, in- 
termediate between the carbonate and bi-carbonate, coosisting of 
Carbonic acid, 39.76 or 3 proportions =66 
Soda, - - 38.55 or 2 " 64 

Water, - - 21.69 or 4 " 36 

100. 166 its equivalent. 

3. Uses. — An elegant antadd; it is now prepared in the large 
way, and is perhaps preferable, on some accounts, to the bi-carbcxi- 
ate of potassa. It is taken freely ; the dose mentioned in the phar- 
Kiacopceias is two scruples a day, using the effloresced ciystals, which 
will contain about twice as much alkali as the crystals. It may be 
taken in powder or in pills. It should be kept in families. 

The efiervescing draughts which are made with what are called 
soda powders are not soda water j the powders are put up in papers ; 
the blue paper contains half a drachm of carbonate of soda, and tbe 
white twen^ five grains of tartaric acid, which require half a [»Dt of 
water ; the efiervescing drink is a mixture of tartrate of soda and cat^ 
bonic acid, with perhaps some free alkali. The Seidlitz powders 
have two drachms of tanarized soda and two scruples of carbooale 
of soda in tbe white paper, and thirty five grains of tartaric acid in 
the blue ; to a solution of the former in half a pint of water the latter is 
added. These preparations are however both useful and agreeable.f 

CABBONATES OE AMMOHIA. 

1. Names, Six.— -In the shops, tolatile tidu or concrete^ volatile 
aOttdi, tal comu cervt, or salt of hartshorn ; volatile talts, is the name 
most familiar to the apothecary, (it is now called in chemistry, sesqui- 
carbonate.) 

3. Prepaaation, of the lalt of the thops. 

(a.) Obtained in the manufactoriei, by distilling, in earthen or iron 
retorts— ion£(, hoTiu, or other ,^nn aninud subttances.'l 

(b.) In pharmacy, &y heating dry chalk, 1 part, and dry muriate 
of ammonia, 2 parti, in an earthen retort, or one of coated glass; 
die sublimed salt is condensed in a cold receiver.^ 

ie.) Proceia of the apothecaria. — Muriate of amm(Hiia, 1 part, 
carboDale of lime, 1^, are mingled, 100 cwt. or more at once; 



■ Sm Quart Jour. Vll. 298, u>d Ucory, Vol. I, p. S88, 10th «d. 

I Coxc. t See Aminoiiia, p. 296.— 10. 

\ It will be Men, firther on, that the salt rarmed in IhU mumer hu diflereol pre- 
portloiu from Siat which is prepared by aluglmg the gases Id equal volamea ; the 
litter b atiictly the carbonate. 



D,q,fzodbyGo(lg[c 



304 CARBONATES. 

an iron pot with an earthen head, commtmtcfttiag with a cold 
receiver, usually a jug or bottle ; (the olive oil bottles, after beiu 
deeiued, are ct>min<»ily preferred ;} the carbcHiate of antinoaia, pro- 
duced from repeated charges of the materials, accumulates by de- 
crees to a thick crust, aad the botdes are then broken to extract H- 
Sometimes lead receivera are employed, and then the crust is detach- 
ed by repeated blows of a wooden hammer, applied to the outside.* 

3. Properties, of the iall of the thop». 

■ ' (a.) 7^ ery$talt art to minute at to beindittinct; they are said 
to be octahedra with truncated apices. 

{b.) yoldtiU and odwoiu ; smell and taste are like those of pure 
MniDonia, but weaker. The hartshorn smelling bottles, are Uued with 
this sdt, whose od(»: is reviving, stimulating, and refreshing. 

(e.) Hat the utwU alkaline action ttpon the fett colort. 

((j.) Soluble at 60°, in less than 3 parts of cold water ; and ia one 
of not water. 

In boiling water volatilized, and also perhaps, decomposed, and 
exhaled in gas and vapor, with brisk ebullilioD and a strong ammo' 
macal odor. 

(«.) The hot solution by rapid cooling, crystallizes.f 

( M Aof altered hy the air, bvi matta rapidly auiay. 

(f.) Evaporatet on a hoi iron, without melting, being more vapor- 
isable than fuable. Smelling botdes are eadly made by heatiii^ 
a porti(Hi of this salt in a flask, whose neck is prolonged by a tube, 
covered by an inverted empty vial, in which the sublimed salt will 
be condensed and form a crust or lining. 

4. Action or the preceding bodies. 

(fl.) J^earty the tame thai hat heen stated with retpect to the prectd- 
ing alkaliet ; they and tlio alkaline earths attract its acid and liberate 
the ammonia, while the acids attract the ammonia and liberate the 
acid gas with effervescence ; if the acid is a fuming one, there is a 
white cloud. 

(6.) No action on siUca, alumina, or zirconia; but dissolves gluci- 
na readily. I 

(c.) Jfy double affinily, decomposes variout tails whicJt ammonia 
vlone unlinot affect ; particularly the baryiic, sirontitic, and calcare- 
ous, but the carbonic acid often holds suspended the earthy carbo- 
nate, so that it does not precipitate till heat is applied, sometimes 
erea to ebullition. 



* Dt Murray'* L«ctiire on Materia Medica, March 26, ISM. 
I Bergman. Four. IV. 74. 

t It leparatei i^luciaa trom Iha other earths contained in the beryl and emerald ; 
and by «?apor«ttOD, ildepoaiU the glucioa. Four. IV.7B, and this work, p. 196. 



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CARBONATES. 381 

SE9«UI*-CABB0MATE. 

Thu name, as alreadjr implied, has been ^ven to the salt just de- 
scribed, and which is obtained by aubliminz 1 part of mm-iate of am- 
monia, and li of dry carbonate of lime ; if no loss were sustained, k 
riiould contam equal quantities ofcarbonic acid, ammooia, and water; 
but both ammonia and water are wasted by the he&t, and it in fact 
coosists of about 65 acid, 30 base, and 15 water, corre^KXiding very 
nearly with the constitudoo, of acid, 3 prt^rtkms, =66, base, % 
=s34, water,S=18.=116, for its equiv^ent. This is Dr. Hen^s 
view, and if correct, there seems to be no occasion, in this case, Ua 
a name implying half a proportion ; for 66 is obrioualy a multiple of 
22, as 34 is of 17.-|- 

CARBONATE OF AMHONIA. 

1. Pbefaration.— There is but one mode of forming the carbo- 
nate containing one equivalent of each of the principles, and that is by 
mingling carbonic acid gat 1 Wwne, and ammonia 3, over mercury ; 
(H- in a dry bottle, the gases combg from difierent vessels ; the scud 
carbonate is precipitated, and crystallizes in plumose rays od the 
interior of the vessels. 

Either of die arrangements represented by the annexed figures 
will answer very well lor this experiment ; muriate of ammonia and 
lime being in one of the retorts or flasks, and marble powder and 
diluted sulphuric acid in the other. A mild heat is applied to the 
vessel containing the materials for afibrding ammonia, and the mid- 
dle vessel receives the condensed gases. 




3. Composition. — ^Acid, 56.20, 1 {tfojiortioD, 22 
Alkali, 43.80, 1 " 17 

100.00 39, its e(|utvalenL 

This sah is unknown in the shops. 

* Ss«aw— Litla, one ukd i hilf. 

t Dr. Thommi, who introduced Qie tarm Mtqni, to protida tot cum, whara there 
«ppain tobe half inequlTtlenl, adnilli frtelloiii ofatomiu (.praTWowi tnod* of 
aipreadtti, alllMugb, u he dlMlncUy eiplalna, fiom be Terr oalnre of atDmi. thev 



D„tiidD,Googlc 



380 CARBONATES- 

BI-CARBOSATS. 

1. Prbparation, be. 

(a.) Throi^h a aolution of the carbonate, in Noolh's or otbet 
convenieDt machine, pau a itream ofearbonic acid gaa to saUiratkin. 

(i.) Gentle eraporadoa gives small six »ded prisms, inodorous and 
nearly tasteless- 

f c.) A salt extremelysimilar, appears to be formed, when coiamoo 
canmnate of ammonls of the ^ps, is simply exposed in powder, to 
the air; it loses sometimes nearly half its weight, in a smgle nighi; 
(be ammonia and perhaps the water, are more wasted than the car- 
bonic acid, and tbe proporticm of the latter is doubled. We may 
often obserre that the voladle salts of the ^ops, when exposed to 
the air, become nearly ioodorous and their taste less active. 

Tbe composititHi, excludve of water, is, 

Carb. acid, 71.81, 2 propOTtions, - - - 44 
Ammonia, 28.19, 1 " - - - 17 

100.00 Its equivalent 61 

" By varying the prraortions of the ingredients and the regulation 
of tbe heat, it is posable to obtain a hi-carbonate at once, by subti- 
mati<w.* 

Rebukes. — ^The carbonate of ammonia commonly used b medi- 
cine and chemistry, is that of tbe shops. In medicine, it is a valua- 
ble remedy ; stimulating, diuretic, antacid, and-poisonous, 8ic. Tbe 
smelling bottles diat have not been exposed much to the air, exhale an 
odor that is highly stimulaiing ; but by careless keeping or frequ«it 
opemng, they often lose their activity. As a reagent, Uie carixmaie 
of ammonia is very valuable in chemistry ; it is the most convenient 
application, for the removal of acid stains from dark clothes. It 
should be used m solution. 

This is an elegant salt, composed entirely of condensed gases; its 
elements are, for the acid, carbon and oxygen ; for the ammcHiia, 
hydrogen and nitrogen. f It is a striking example of tbe produc- 
tion of new properties by chemical combination. 

EARTHY CARBONATES CAItBONATE OF LIMB. 

I. Names. — Chalk, limettane, vutrble, calcaTeoits tpar, ttaiactUe^ 
tfc. — ^The natural carbonate of lime, is in these and other forms, most 
extensively difiiised, and contributes to many purposes of omanient 
and utility. 



opropor. orcarb. tcid, 44+Iaruii 



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CARBONATES. 387 

S. General characters or the carbonates of lihe. 

ia.) Do not scintillate, if pure. 
b.) Insoluble in pure water, 
c.) Efiervesce with acids generally, but unequally.* 
d.) Become quick lime by a strong heat. 
e.) Sp. gr. under 3., generally not orer 3.7. 
y.) Every variety of aggregalioD, from compact, and even earthy, 
to perfect crystals, which are much diversified in form. 

{e.) The crystals of all pure calcareous carbonates, between 600 
and 700 in number, have a rhomboidal nucleus, whose faces are 
incUned at angles of 75° 55' aod 105° 5'. 
3. Chemicai. properties. 

(a.) Cal0ru:i~~JYative cryttaiUzed carbonate deer^Uatu with 
heat, ^nition t^araies the caiionic acid giu,\ and the watery 
vapor, and caustic lime remains. By strong ignition, it loses .44 or 
.45 in weight, about .44 of which is acid. 

(b.) That the caiulic^ of lime it owing to the lott ofearhonie 
aad, was discovered by Dr. Black in 1756. 

ie.) This gas in contact with caustic lime, renders it ^ain mild 
effervescent,! ^■'^^ restores the weight lost by the iiimace. 
id.) Not aSected by air nor water, 
e.) Soluble in liquid carbonic add. — If saturated with the acid, 
water dissolves ttVt °^ carbonate of lime. Ume water is a most 
sensible test of carbonic acid, producing a milky appearance, and 
carbonate of Ume precipitates; but if more carbonated water be ad- 
ded, the precipitate is redissolved, and the fluid becomes again trans- 
parent. 

(/.) If the excess of carbonic acid be saturated by more lime 
water, or by ammonia, the carlxHiate of lime is again precipitated. 
It is pre^itated also by boiling, and by air pump exhausoon. 

{g.) liie formation of stalactites, and staJagmites, and calcareous 
incrustations of various forms, in caverns and veins, and of calcare- 
ous petrifactions, and the precipitation of the carbonate in a crys- 
talline or sub-crystalline form, as the water and gas evaporate, de- 
pend upon the solution of limestone, by liquid carbonic acid. In 
limestone cotmtries, carbonate of lime is dissolved in the waters, itsu- 

' Some carboiulci. eap«ritl\y of eirtba, require to bo fiaalf pulveilied. 

I Sir Jtmei Hall, by some very Ingenhm* eipariineali, od cirbonila oTliiiM, u 
(• lfa« «SmU of pressure in counlerRcttnr thoM of beet, (uECeeded in melting diit 
■ubtteDce, end causinir il to cryalilUte bcUd, without lo^UK id carbonic uld. SJHa, 
Trtni. Vol. VI, pertL Nlchol»oo'i Joor. Vol. XIII, XIV. 

Hr. Baeholz ilea melted the cerboiute of lime byllw sudden ■ppUcatkn of m vio- 
ket heil, without eampreaslm. — Nlchalmi'l Jour. ^SiVlI, aad Uenry, VoL I, p. 
»8, lOdi Ed. 

t Tbe lima ihould be moiit, or In the rtite of eraun of Unw, or leut of (tie hj- 
dcUe, u the (U li not mdllyifcaorbed by the dry eirth. 



OMzcdoyGoOglc 



188 CARBONATES. 

alljr 'by the agem^ c^ carbonic scid, uid appears in the duneaac 
utensils ; it is depomted by boilbg, die gas being thus expelled.* 

4. Action or pbxcedino bodies. 

la.\ Oeampoted by aadi, with effervacence.\ 

(b.) JVo heat is evolved by aadi acting on a calcaremu carhonale, 
while with quick lime, there is great beat, especiaUjr with sulphuric 
^d. The same is true of poussa, soda, and ma|Dena, when cata- 
pared with their carbonates. In the cases in which gas is e¥olved, 
die beat is absorbed to form it, and thus becomes latent, and iosensi- 
Ue ; Uie opposite will iherefOTe be true of the caustic substabces. 

5. Estimation or fboportions. 

(a.) This subject has occupied the attention of many distinguidwd 
chemists. The analyses of Dr. Wdlsston, Prof. Berzelius, and Dr. 
Vn coincide so nearly in the proportions of 44 add and 56 lime, 
that these numbers hare been adopted by Dr. Henir, and they o«^ 
respond with one proportion of acid, 23, and 1 of hme, 283=50 for 
the eqinvaleni. 

(A.) To auxrtain the proportion tf caritmate of liaie in any »arl 
or Mietfone.|— Eflervescence with acids is generally r^arded as a 
proof of the presence of a carbonate of Ume. There are, however, 
carbonates of other substances, and there are other combined gases, 
bendes carbonic acid, that may be disengaged with efiervescence, 
by acids; but these cases are so tare, and the other so conunoo, 
that there is little danger of mistake, especially when the pecuhar 
characters of the oUier carbonates are taken into view. 

(c.) We muit not be deceived by the comnon air lodged m fie 
pore* of dry earthy bodiet; when the acid is added, this air a ex- 
pelled by hydrostatic pressure, and exhibits a false efiervescence. 
The matter should be first immersed in water, and the air thus ex- 
pelled, and then the acid may be added. 

{d.) For an acatrate retvU, place in one scale, in a flask 100 grs. 
of the substance, and in a separate vessel, 100 of muiiatic acid, mix- 
ed with 300 of water, and put a counterpoise to the whole in the fsppo- 
site scale. Add the diluted acid, by degrees, till efiervescence luu 
ceased, and then weigh the residuum accurately. The loss of weight 
it the carbonic acid; therelbre, 44 : 100 : : the weight loct to the {vo- 
portion of carbonate of lime,^ granting that there is no other catboo- 



■ Ths Mmpomllr injurknu eHecU oT ■ach waten upon the haallh of mtgin 
m wall knowD. 

I Even Tloegar will, in ■ derret, produca fliat afibcL 

t See Ure'a IMct. M Ed. p. &T. 

I Carboaate of onnMid* nay be pre«aiit 

FrenilOOenbuofcariMnaleoriiino.SOorHcuUelDcheaofgMaiaaUalMd. Il 
U a rich uarl, that hM 1-4 of Ita weight cf carba&ata of llMM, and aomettaMi Miti lb 
Mt cealein mora than l-Wa. In intinf marit, yen n^ redHo 3 1-S gniv of 



OMzcdoyGoOglc 



ate present ; a cfxnidete sohitioD indicaMs a pure carlXKiaU, proba- 
bly of lime, « oT lime and magnesia.* 

(e.) Eaipel the giu by a red heat, and compare the wei^ lost in 
tins trial and in the other experiment ; the loss may be a little etm^ 
er on account of water. We must aln tir the residuum with an 
acid to see whether it efiervesces, and nfaedier it coutakis mag- 

XJai9j~^Ax an antacid ; in chdlk, as a crayon ; in marble and othnl-. 
9obd forms, as a building stcne, valuable bodi for firmness and bek»< 
1y ; to afibrd Inse bybtiraiag, and caibotiic aoid for die chemists and 
manufacturers ; as a manure, both in tbe fomi of lime and of cbi> 
bonatiB of Kme—the burning appears to be (tf no use, except to di- 
nunish we^K and cohesion, lo that it may be scattered in powder 
on the land, where, if it be quick Hme, it reabsorbs csibtmic acid and 
water, and becomes again carbonate of Hme. 

CABBONATE Or BARYTA. 

1. DiSCOVSBT. 

(a.) By ScHEELE and Bebohad, but Dr. Witbebiitq,} first 
found the native mineral in 1783. 

2. Pkepabatioit. — For demonstraticHis, the native earbonale iff 
baryta may be uied, but for instruction, a number of processes may 
be mentioned. 

(a.) By pasting a current of earlanie add gas throvgk a soluuon 
, of pure baryta, 

(6.) By expoting the latter to the air, when a pellicle of carbonate 
of baryta forms on the surface, and being removed, another suc- 
ceeds, and 50 OQ, till the baryta is all precipilated. 

(c.) By mixing vmtery lolviiont o/carionic add and baryta, 

(d.) By decompotitig, by fire, the niiphate of baryta, 1 part; fiy 
the carbonate of a fixed aUcali, 3 or 3 parts. 

(e.) By any aMaiine carbonate, added to the nitrate or mwiate of 
baryta. 

(f.) By blowing air from the lungs through barytic water. 

UmeitoiM, orl 1-2 ijalni of lime for every grilatbe mar) Icxei by the experiment 
of expelliDf the i!r. Tinefcir li not lumciently itronK, and It rrothi ind became* 
clunniy, iihI remilnB (or Mveral ivia wilbout permltlintt all die eib to escipe. — 
BladetLtcl. Vol. 11, p. 120. 

* The rciiduum, if any, ibauld be drlsd, and neighed, and this may (wrect flte 
Ibriker eoncluiion. 

t If niagneaia be preaent, it will be detected by sulpburic add, which will fbriD 
a bitter Nliible and cryitallizable lulphate of maf^eaia, orEpaomult. Sucba marl or 
limeitoae would be Injunoiu, if applied in agriculture. In quantiUea aa lirfe M 

when a pure calc&reoui earth ia employed ; much lees of it aniwera the purpoae 

Nlcbolaon'a Jour. Ito. Tol. Ill, p. 440, Riil. Trana. 1T99, part II, p. SOS, aod Bake- 



OMzcdoyGoOglc 



390 CARBONATES. 

{g.) By adding earbomUe of soda to the h^roguretted ndpkant 
of baryta, formed by decoraposing the native* sulphuret, by igniuoo 
with cDarcoai, as already described. 

3. Propcsties. 

{a.) llie artificial cBrbonate is a white powder whose specific 
grarihr is 3.763 ; th&t of the native, 4.3 or 4.4. 

(&.) Caloric. — Dr. Hope often expelled the carbonic acid fay 
the well managed heal of a smhh's forge,-)- and obtained the caustic 
earth. 

(c.) Fusible on charcoal, loang at the same time, seme of the cw 
booic acid. 

(d.) Hix| 6ne powder, of atber artifit^ or native carbonate of 
ba^la, with about its vohime of lampblack, and add lamp oil, until 
the mass can be rolled into a ball ; place it in a black lead crucibie, 
surrounding it with lam[^lack or charcoal powder, and lute on a 
cover ; heat the whole in a mod forge or wind furnace for an hour. 
The ball still retaining its form, may now be taken out, and btnliDg 
hot water added ; it will slack powerfully, and when cold, will shoM 
into beaudful crystals. 

(e.) Soluble m 4300 parU of water at &Q°, in 2300 at 212<> ; tra- 
ter impregnated with carbonic acid, dissolves with some faciUty that 
which has been recenthr precipitated, and takes up ^\f ; it is 
precipitated and redissolveo exacdy in the same modes tbat were 
mentioned under carbonate of lime. 



(f.\ Tattele*i — no effect on tett co/or<. 



Ig.) A vioUrit poiton, not known in common life, except in those 
places where it is found native. 

(A.) Oecompoted by moit of the aeidt with effervetcence, produc- 
ii^ suts i there are some peculiar circumstances which will be men- 
tioned under the other barj;iic combinations. 



■ The DidTe urbonita li ioiiiid In Cumbertmd, (Engluwl,) at AbtOQ Hoar; fa 
I.uicuhlre,>t AnElezirk, DMrChorley, ind in other puti of ElDgUDd ; luSaAlaai, 
■Dd In Sweden. It wu aniKiunced, (Am. Jour. Vol. II,) u exiitine near LtKiofUa, 
Kentucky, but thfahu not been coD£nDeil. Iti« commoaly bund Id mstillic Tdu 
■long witiinilpbite oTbaryta, and tbHoui melalUe BUbelucei. Itatg.rr.ltiJttt 
4A, wti«nce It appears that ll U much heavier thin the aitificUl ; it 1* a litUa fawder 
Ami carbonate oflim a, butionar than the fluate. 

t Dr. Prleatley, by iteiin, ptMed over die Ignited artificial carbonate, reduced H 
to tha ilate of baryta ; In tbi* eaae, the attraction of the water for the hue, lidi tii> 
decampoaitloa. 

t In thi* proeeM, Die ewbonie add ia not only expelled, bnt in part deeon^uaed 



by the carbon, which, with one proportioD of (be olynn, producei carbonle oilde. 
Tlie pioceia 1 find to be conitanlly niccevful, and It u ven eligible wtien ire irUi 
to obtalo either a toluUon or cryitali of baryta. We may begtn wttll tlie ntlphate, 



OMzcdoyGoOglC 



CASB0NATE9. 391 

4. Composition.— CarbcMiic acid, 32, bwyta, 78=100, its equiv- 
alent. 

&. MiscELUNxovs. — Used for a long time in Lancaahire, to kill 
Tats. With 40 grg. Mr. Wall killed a small do^; even 16 grains 
mU produce that efibct. It appears that domestc fowls are some- 
times killed by swallowing fragments of the native spar, and that 
even cows, by licking it, sufier uie same fate.* 

Accordmg to Dr. Hope, there is very little or no difference be- 
tw een lime and baryta in their attraction for carbonic acid ; lime wa- 
ter does not decompose carbonate of baryta, nor the contrary, and 
when carbonic and is added to a mixture of lime water and barytic 
water, carbonates of both those substances are predfutated. 

6. Uses. — Mr. Parkesf states, that great qaantities of the carbo- 
nats of baryta were formerly exported clandestinely from England to 
Germany, where it is supposed it was used in the manufacture of 
porcelain ; it was sold for five dollars a t(». 

Carbonate of baryta is a rather rare production in nature. If it 
were more common, it might be employed with much advantage in 
some of the arts — as, to afford baryta, which, in building, would f{»Tn 
a stronger cement than lime, and to decompose some of the com-- 
pound salts. Pure baryta in solution, will separate the carbonic acid 
entirely Imn a solutioo of carbcHiate of poussa or soda, and leave 
the a]kali caustic. 

CARBONATE OF BTBONTIA. 

1. DiscoTEKT. — ,3t Jirtt confounded with the preceding ; the dif- 
ference suspected by Dr. Crawford, was proved by Dr. Hope.| 

3. Prep ABAT ION. 

(a.) By adding liquid carbonic add to a soliUioa ofttfontia, the 
precipitate, is again soluble in an excess of carbonic acid, and b 
thrown down by more of the earth, and so on in the same way as that 
mentioned under the carbonates of lime and of baryU. 

(fc.) By the rartout methods <dready indicated, for the formation 
of a carbonate of baryta, strontia bemg of course substituted. 

The native carbonate, although a very rare production, is com- 
iiKHily used in laboratories ; it is found at Stronban, in Ai^leshire, 
and at Lead Hills, in Scodand, inc. 

3. Properties. 

(a.) The native carbonate hai afibroiu and columnar texture, and 
the cavities are usually Uoed with crystals, which are generally trans- 
lucent; the color is green or greenish; sp. gr. 3.55 or 3.66; does 
not fire with steel ; it is softer than the nuate, although harder dian 



I £*«y<. Vol. 1, p. 32T. I Vide Kdiu. Traiu. ITttS. 



OMzcdoyGoOglc 



993 OAUMniATK& 

thAcatboaUaofKine; wliihle in 1536 parts c^botfing ivster. kg 

iDnpid. 

(o.) F\inble at 336°, W. into a ghui; lostog 6 or 6 per ceo-d 
hs carbonic acid ; in a black lead cnictUe, aad especially if mix<^ 
with charcoal and oil, the carbonic acid is wbaUy expelled, and tb 
caustic earth rernaiDs; this ma^ be done in a smitb's iorge; m< 
itrongfire, it fluxes a Heitian cntdblt and produce* a glau ruoA- 
Mng dttytaUte. 

Ye.) ^ir dou not tiffexA it. 

(d.) Decompottd by the add*, with efie^eacence. 

4. CoMPoatTioir.'^According to the aoalysis of StToaneyer,* dx 
artificial carbonate cwitahis no water, and lu« very nearly .30 or- 
bonic acid, and .70 strontia. 

The equivalent of stroada, is fiS, that of carhonio acid, 33, and a 
32 : 53 : : 70 ! 30, very nearly ; so that the theoretical ooBstitaOCB 
agrees almost with the results of analysifl. 

ft. MisczLi^raouB. 

{a.) Strontia taket the a^imic acid from ail the aHaUiea ; ita cu- 
boiiate, with the aid of beat, is decomposed by baryta only if ^* 
is uncertain which of the alkaline eanbs has the stroDger atiracsop 
for carbonic add.| Distinguished from caHranate of baryta, bytf 
nfiriar xp. gr.hy^iaa fact that tto taUi yield their addM to iwyta, 
and that if u not poitonout ; animals may take it with impum^ i *^ 
nitrate tmgu the flame of a candle red ; that of baryta tin^ « J^ 
low; under the compound blowpipe, all itg vtmeiues gwe a f™ 
flame, and all tboae of baryta a yellow one. It has never Deeo '"""^ 
duced into medicine, and is of no use except to chemists. 

CAKBONATS OF HAONEEIA. 

1. HiSTORT. — Long known, but not well understood till i«- 
Black gave its true theory, as well as that of Hme and the alkalies-^ 

2. Prepajlation. 

(a.) By tloiply ditiolving pure magnesia in liquid carbonic aad.} 



* Ado. d«Cbiai.atd«Phyi. Ill, aw. 

t Tour. IV, M. 1 0r. Hope. 

$ Every ftudeiit (bould read Dr. Black'i own iccoimt of Uie gndutl dev«lapo*>'|^ 
of lbi( curloui iDd iDitnicdve subject — Dimeljr, (he reUtioii of eirbonlc acid to |B( 
aikallna ■ubauneei ; it la a fina ssuDple of iodiictiTe reaKming, and hat eoaOiMtif 
BKHw than any o(b«r thing lo thepragnmof pnsnmatic chemiitry. Sea Bct'aV 
Black'i Lectures. , 

H A aatire carbonate or magneiiahu been (bund In ttieEut Indies, and uilT^ 

a Dr. Hmry, Ann. of Phlloa. N. S. 1, 8B2. Nattve carboostei hare bceo bom t 
Eiboben, near New York, Am. Jour. Vol. 1. Cairined or pure roagneda, miBU 
Ibe alkalies sad the other alkaliOB earths, does not abaorb much carbonic add bil*' 



J^^ 



CARBONATES. 993 

t/ deeompofing the ndphate of magnesia, by the carbonate of 
— Tfae sulphate, 1 part, dissolved in 2 parts of pure wuer ; 
and 1 part of pearl ashes, di^lved in 4 or 6 parts of water,* 

Dr. Black's process. — Mix the two solutions by violent agiiatioD, 
and let the mixture merely boil; add four parts of water, at 212°, 
and again agitate briskly. After repose, the magnewa subsides very 
slowly, in the form of an impalpable powder ; next decant, and to 
remove the sulphate of potassa, edulcorate ten or twelve times with 
abundance of cold water. f 

Lastly, the magnesia must be gently pressed on a clean \iaea 
cloth, for the filtering papers will not do, on account of the jelly- 
like consistency, which magnesia, when wet, assumes. It is divided 
into cubical pieces, by cutting it before it is quite dry, with a square 
frame ; but when dried, it becomes an exceedingly light and spon- 
gy powder, and this extreme lightness is one of the best marks of its 
goodness.^ 

In decomposing the sulphate of magneda with tlie carbonate of 
potassa,^ or other alkaline carbonates ; the precipitate does not eJ- 
■wzjs immediately appear, because the carbonate of magnesia is held 
Mt solution by the carbonic acid, and is precipitated as fast as this b 
evaporated, spontaneously or by heat, or by the air pump. 

3. Properties, 

(a,) .tf miid, white, friable, spongy lubitance, very light, but usu- 
ally feebly cohering in a sort of cake, generally so light on account 
of its ■poTO&n, as to float on water ; but it eventually absorbs ao 
much as to snik. 

(b.) Solubility in water; 1 part of carbonate ofmagneda, in34d3 
parts of cold, and 9000 of hot water, presenting a singular anomaly, 
which is doubdess owing to the additional elasticity given to the car- 
bonic acid by the beat, and the hotter the water is, the more carbonic 
acid is expelled, and the more insoluble the carbonate becomes. 

(c.) This solution changes the color of purple cabbage or mallows, 
to green. 

\d.) Suffers no change from the air. 



ting Id it the white of an egg, when (he aolulion It joit winn enoagfa to piu 
cotguletiaD. 

i Hot water occasiom », miieh longer laqteiisJOD of the munsda. 

i The theory which Dr. Dlai^ wai esUbliahing cwicenung the combined ititB 
of carbonic acid, made him pecutlirlj Dice In ibe preparaUon of magnet Dlark, 
II, ST, aod Dr. Murray'* prirate iMtmctlaDi. 

^ Aatbe common pearl ashee ofiea cootains riliea, the magDcdamay ba examhwd 
by sulphuric Kctd, id which. If pure. It is entirely aoluble, while tlu itUcm wEU be 
left betlDJ. Iftbe cu-boaate ofamDumkaor of nda, ware employed, diere would 
be no danger of the preaenceofsillcajaiMl the bi-carbontieorpotaMwoub) not coo- 
lain It. 

50 



OMzcdoyGoOglc 



(e.) Deeompoied by aU ike adds, wUti efiervescence. 

(/.) Ji*o by all the alkaline baia, forming carbonates ; and in 
turn aecompoiet their lalu, by double attncQCHi. 
, (g*.)' Lime water and carbonate of magnesia produce a mixed pre- 
cipitaKof the two carbooates. 

4. Composition. — According to Bucholz, if precipitated wiii 
heat, it contains magnesia 43, carbcmic acid 35, water 33; if widi- 
out, magnesia 33, carbonic acid 32, water 35. Mr. DaJlon states k 
at magnesia 43, carbonic acid 40, water 17, Berzelius thinks tJut ii 
is a compound of carbonate of magnesia, 3 proportions, with one of 
what is called quadro-hydrate of the same earth. Dr. Henry in- 
cUnes lo the same opinion, and states the composition thus; 
3 equivalents of carbooate, 42x3=126 69.2 

1 do. quadro-hydrate, 20+36= &6 30.8 

Its equivalent, 182 100.0 
Or of magnena in the carbonate, - - 32.93 > .^ g^ 

Do. in the hydrate, - - - II -OO J 
Carbonic acid, . - - - . - 36.^ 
Water, - 19.75 

100.00 
Berzelius found the tiommon magnesia of the shops, after being Aor- 
ougbly washed in boiling hot water, to be composed of m^esia 
44.S8, carbonic acid 35.70, water 19.72 = 100.00. 

CRYSTALLIZED CARBONATE Ot KAGNEBIA. 

1. Process. — By diffiising magnesia in water, and paamg'car' 
rent of carbonic acid gas through it to saturation. 

3. pROrERTIES. 

(a.) Much more tolable than the carbonate, requiring on^ ^ 
parts of c(dd water, and water impregnated with carbonic acid okea 
up 13 grains to the ounce. 

(b.) When the tolutton it heated, although transparent before, tt 
&«o>nejtur&t(f, and again resumes its transparency on becoming co/d.f 

(c.) It cryilcdlixes,intran»parent hexagonal pritnUjlermatxeAoy 
■a hexagonal plane ; partly in groups and partly solitary ; length about 
6 lines, and breadUi 2. 

(d.) Effioretcei in the air, and decrepitatee in the fire; it loses 
about .75 of its weight, while the conunon carbonate loses only ■^' 

■"nionMOD'BllntFriDclplei, Vol. II, p.SOS, andHeary, IDthed. Vol. 1, p.6IT- 

t The hut muBt b« diacontlaued juit It Ihe point whare the nluiion beeomHtiu- 

bid, or Iho cirbonlc edd will be driven otT. The reuon oT thli tarbidoaM b v^ 

Mjed 10 be die elutldly of the gu, ttnding la eicKpe, ind thereby itgiaai»i^ 

Six go ita liold on the nufneila. — Dr. Hope, JVate Book. 



...Cod'^lc 



CARBONIC OXIDE. 39$ 

(e.) During the diseDgagemeot of the gas, the powder seems as if 
boiliog, and is said to emit, towarda the end, abluish phospbortc tight.* 

Itemark. — The ahore described salt has been regarded as a bi- 
oaxbonate, but Dr. Henry is of opinion, irom Ms own analysis and 
&om that of Berzelius, that it is a hydrated carbonate and that its 
compoaitioa is 

1 equivalent of magnesia, - - 20 28.60 

1 do. carbonic acid, - - 23 32. 

3 do. water, - - - 27 39.40 

Its equivalent 69 100.00 
It appears that, although the anhydrous carbonBtc* has been found 
natire, (see note p. 393,^ it has not yet been formed by art. 

Berzelius has ibnnecl a carbonate of magnesia and potassa, by 
mingling bi-caifaonate of potassa and muriate of magnesia. It seems, 
to be of litde importance, f 

3. MiscELLANZors.— Jn the arts, the carbonate of magnesia is pre- 
pared from the bittern of the tait pant, remaining from the crystidli- 
zaticMi of common salt, which contains much muriate and sulphate of 
magnesia. Carbonate of either of the altcalies, by double exchange, ' 
afibrds carbonate of magneaa, whose precipitation is hastened by 
boiling. 

4. Uses. — Ai an antadd and eathariie. (See m^inena, p. 373.) 
On account of the flatulency sometimes produced by the carbonate 
of magnesia, calcined magnesia is used. Dr. Black says that it 
is liable to contain a portion of quick lime, derived from the sul- 
phate of lime of the bittern. No other earth has cathartic powers ; 
most of the rest ate austere and astringent, parUcularly lime. 

CARBOiriC OR CARBONOCS OXIDE. 

1. History. — Ditcovered by Dr. Priestley f who obtained it 
from dry metallic oxides with dry charcoal, and thought it was, at 
least in part, hydrogen, or that hydrogen entered into its composi- 
tion ; it therefore revived, for a season, the once favorite notion of a 
pbk^stic| principle in the metals, charcoal, &c. and an animated con- 

• roar. IV. 67. t Edin, Phil. Jour. II. «T, «nd Henry, I. 619. 

1 1 Inppened to be io Philvlclphia, u a pupil of Dr. Woodbouse, In the winler ai 
lSOS-8, vrhsD Dr. PrietUey, nho, ■■ ii well kDown, pined the latter jtus athU Kfe 
Id Penneylrttlla, Mma in person, to the iKboretory of Dr. Woodhoiue, who wu 
UntKliadltelpIeof LavoUier, and who performed virioui experimenta on thia topic, 
at Ihu lime keeoly controverted. It wu &» lait effort to auatslQ the doctrine of 
^logWoD, and to produce frooi metala and Inflammablei a real nibatance, to which 
' ft was aupposed that the name of pblo^ilon could be applied. Hydrocen bad been 
befcre called phlot^ston, but IE was Impoialble to prore Its eiiatence In airiDSamiiiible 



befcre called pblo|^rton, but IE was Impoialble to prore Iti 

boiflea and metala, (unlcaa the diacovcry of Ihu sag ahouia Esuuuan il,j huu » wu 
dMinetly proved that it forma water by its combustion. Indeed Dr. Priestley wa* 
onet^the first to perfbrn that interesting experiment, but be did not eTcatually ad- 
nil Ihe conclusion. 



:.,C(Xlt^[c 



396 CARBONIC OXIDE. 

Vnyenj respeciiog it was for aome time mainlaiDed, but its true na- 
turo WH9 sooD pointed out, hj the late Mr. Cniicksbaoks, of Wool- 
wich, England ;* Clement and DesonDesf completed the demoo- 
stratiwi, and the refutation of the' ideas of the associated Dutch 
chemists and others, who took it for a rarie^ of carburetted hydro- 
gen gas-t 

3. Prepakation. — All the processes mentioned bcdow, are in- 
structive. The; all shew, (that under {g) excepted,} the formalioD of 
an oxide of carboa, either by the combmatioD of 1 equivaleDt of oxy- 
gen with 1 of carbon, or by the removal of 1 equivalent of oxygen 
tram carlxHiic acid, leaving 1 of carbon and 1 of oxygen in combina- 
tioD. To the fonner belong the processes (a) (ej, and (/.} to the 
latter (b\,{c), and {d} ; {g) is peculiar. 

(a.) Heat tekite oxide ofxinc with i of ckarcwU povder or iron 

(o.) Or iron filings with an eq^al weight of chalk, [H'eTiousIy heat- 
ed moderately red. 

(c.) Or dry carbonate of lime or of baryt<^ with j charcoal pow- 
der, premontly ignited; or heat the lame carbonatea with i or i of 

J 'ttngf* or metaHic zinc. 

passing carbonic acid over charcoal or iron filings, ignited 



dry tronfiiingi or metailic zinc. 

(d.) By passing carbonic acid < 
Id an earthen or perhaps iron nibe-lj 



(e.) Heat equal parts of the scales of iron with dried charcoal 
powder. 

{f.) Manganese, after ceasing to give oxygen by beat aknie, mix- 
ed with an equal weight of charcoal, previously ^i;nited.^ 

(g.) Still another process has been introduced, by ntixing taU of 
torrd 1 jwirt (bin-oxalate of potath) with b or 6 of nUphuric add, 
and heating the mixture to ebullition in a retort ; decomposition of 
the oxalic acid ensues, and carbonic acid nnd carbonic oxide are 
evolved in equal measures ; the former is easily absorbed by a caustic 
alkali or by ume water, and leaves the latter pure. Tlie sulphiuic 
acid is not decomposed ; it remains limpid, and operates by uniting 

' Nich. Jour. 4to, Vol. V. I Ann. de Chim. Vol. XXXIX. 

t AnikdoChlm. XXXIX.U, andXLI[l. 

I The dry urbonMo of birjti and dry tron dliagn ffvt Ibe purest gn, ind Dearly 
tne from carbooic acid. The pracen wiili oxide or zinc and Eran Glinn, i.i ons of 
(ha belt, and aObrdi abuudance ot cm which li easily purilicd by wnshinF It with 
caurtic alkali or lime walcr. 

tSee NIch. Jour. Vol, II, p. 116, Tor Rnruel's apparatus. 
Any carbonate, lliat will suotain Igniiion, nithout ilccoiuposilion, wilt avo nr- 
bonlc oxide, if heated with half ila H-ei;;ht of iron Gllngi or charcoal ; iron \t of 
couiM, oikUzed by the oxygen wUhdnwD from Uio carbonic acid which undergoes 
(tecompoiltian, giving up jud half ita o\ygen; aod charcoal Is turned into carbooLC 
Oildo by (ha aams process. The rarbouulci of ati'onlla, wida, potassa and lilhii, 
may be employed in addition (a (lioje thai have been nuniod, and the oxido of lex) 
■Dd capper may be used ivilh cbaicoa!, as ncU a llie oiide of ziuc or iron. 



s CABBONIC OXIDE. 397 

with the alkali of tha salt aod with the water of the oxaHc acid, 
which being thus left at liberty, is decomposed as above.* 
3. PaoFEsmfl. 

(a.) Smell offauiw; edorUit; sp. g?'. 973, common air being 
lOOO. 100 cubic inches weigh 39.65 graios, at medium tempera- 
tuxe and pressure ; having the aame weight as nitrogen. 

(6.) iJoet not svpport tombtutioni a candle mil not burn in it. 
Infiammtdtle, bnr