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r 600009244P 






KiQiut Tuomfoi or chihistit la tbi dbitiuitt or OLtioow, r.R.a. lovdok 


MAtaBAi. HistOBT Mcinr or hobtuui, wrc. btc. 








Ednrd Khun, Hnter, Oit^aw. 



Pabt II. Of Pbimahy Compounds 


Ch^. 1. Of Acids . . . . , . 


Class I. Oxygen acids 


Division I. Acidt with a simple base . 


Sect. 1. Of the aads of cblorioe . . . 


2. Of the adds of bromine aad iodine 


3. Of the acids of azote 


1. Nitric acid . . . . . 


S. Hypoaitrona acid . . . . 


3. Nitrons acid . . . . . 


4. Of the acids of carbon 


1. Carbonic acid . . . . . 


S. Oxalic acid .... 


5. Acids of Boron and Silicon 


1. Boracic acid .... 


2. Silicic acid .... 


6. Of acids of phoephtMtu 


1. Phosphoric acid 


2. PyrophoBphoric acid . 


9. Phosphorous acid 


4. Hypophosphorous actd 


7. Acids of solphnr .... 


1. Sulphoric acid .... 


2. Snlphurons acid .... 


3. Snbsnlphurons acid 


4. Hyposnlphnrons acid . . 


5. Hypoeul|^uric actd 


6. Acids of seleninm and tellurium 


1. Selenio acid .... 


3. Selenious atnd .... 


3. Telluric acid .... 


9. Remuning simple oxygen acids 




Division II. Acids with & compomid base ... 45 

Sect 1. Of Acetic add . 


1. Lactic acid . 


2. Camic acid . 


3. Fibricacid . 


S. Of Fonnic acid 


3. OfMellidcacid 


4. Of Tartaric acid 


5. Of ^Tuucuid . 


7. Of Citric add . 


8. Of Pyrocitric add 


, 9. OfHaUcadd . 


1. Fnngic add 


2. Igasaric add 


S. Lacdo add . 


4. Sulnaic acid 


10. Of Pyromalic add 


11. Of Mndc acid . 


IS. Of Pyromndc add 


13. Of Snodnic add 


14. Of Benioic add 


IS. Of Croconic acid 


16. OfGaUicBcid . 


EUagic add 


17. Of Ulmic add . 


18. Of Cnmeric add 


19. Of Kinic add 


20. Of PyrolrhiiG add 


21. Of Meconic add 


' 22. Of Boletic odd 


23. Of Camphoric add 


24. Of Suberic add 


- 25. OfPectioadd 


26. Of Stearic add 


27. OfHargaricadd 


28. Of Oleic add . 


29. Of Phocenic add 


30. Of Bntyric add 


31. Of Caproic add 


32. Of Capric add 


33. OfHircicacid 


34. Of Ricinic acid 


35. Of Filaiodic add 




^^ ^^^H 

B Sect.a6. Of OvndiA (Kid 199 ^^| 

^L 37. or CrotABtc add 

140 ^H 

^L aa OrAmbnieacfal 

141 ^H 

^^1 80. Of ChalwtMio acU . 


^^H 40. Of Pfaic acid 

145 ^^M 

^^^B Colopbooic aoLd 


^^B 41. Of SUvIc Mid 

149 ^^1 

^^H 42. Of Cu-Wotii! acid . 


^^H 43. Of IndiKDtic acid 


^^H 44. or Uric aci<l 

lAG ^^M 

^^^H 4A. Of Pyru-uric arid 


^^^H 46. Of Anionic ncid 

160 ^H 

^^^^B 47. Of Nitro-sardiaric acid 

163 ^H 

^^H 4it. Of Nilro-leiKic add . 

164 ^^m 

^^^^^^^.49. Of PurparM: add 


^^^^^^K. Er^-thric (Kid 

167 ^^1 

^^^^^^ 50. Of AllAiiloic acid 

167 ^« 

^^^H &l. Of liydnxaiW-mlphuric 

Kid . 

169 ■ 

^^^H fiS. Of «iilj>lui-vinie add . 


^^H 63. Of Xaailiic add 


^^^^B 64. Of Sulpbo-naj^ilhalic acid 


^^^H 55. Of Ve^Ui-Hiilpliurif! ai-id 


^^^ 5*. t)f SUuptc acid 


^■CLAda 11. CliluriiK' Arid* 


^H Srct. 1. Of Hydmcliloric or muriat 

« aci< 


^H 2. Of iiiliiVT Cliloriu« acida 


^BCuuui III. BromtDU Acid> 

H Srct. 1. Of HydrotmBiic acM 


^ Cljiiw IV. lodiiM AcMb 


Clam \'. Fliunhie adda . 


H Sect. 1. Of llydmfliinrie add 


^^^^ S. Vf Fluo-boric acid 

^^^^1 3. Of Fldu-iiilido acid . 

^^^^H 4. Of Plno-molytidii^ acid 
^^^^^ 5. Of FhuKtnngiitio acid 


^^^B 6. Of Flno-chromic acid 


^^^^p 7. Of KTtio.«oltunbic acid 


^^V 0- <^>f Flw^tilanlc acid . 
^FClam VI. CjraaDfeq acida . 



^1 8acL 1. Of CranoKeii 


^^^^ 4. Of llydrovjraiiicadd 


^^^^h 3. Of CyaauUK add 


^^^^P 4. Of Cyanic acid 





Sect, 5. Of Fnlminic acid . . . ... S29 

6. Of Chloro-cyanic scid 


7. Of Perchloride of cyano^n 


8. Of Bromide of cysnogmi . 


9. Of Iodide of cyBoogen , 


10. Of Hydrosolpho-cyanic kdd 


11. Of Hf drosolphnretted hydnmilpho-cy 

anic 1 

idd 245 

12. Of Hydrobisulpho-cyaaiu acid . 


13. Of DiBoIphuret of cyanoj^ . 


14. Of Selenio-cyanogen 


15. Of Hydroferro-cyanic acid 


16. Of Aiulmic acid . , 


Class VII. Snlpbor Acids . 


Chap. II. Of Alkalies 


Ch^. III. Of Neutral Compounds 


SecL 1. Of Water 


2. Of Ardent SpiriU . 


1. Alcohol 


S. Pyro-acetic spirit 


S. Pyroxylic spirit . 


Sect 3. Of Sidphuric eUier . 

. 295 

4. Of Add etfaen 


1. Mnriattc ether . 


, 2. Chloric ether. 


3. Hydrobromic etlier 


4. Hydriodic other . 


5. Solpho-cyanic ether 


6. Nitric ether 


7. Oxalic ether 


8. Acetic ether 


9. Benioic ether 


10. Formic ether 


11. Tartaric ether 


12. Citric ether 


13. Malic ether 


Sect. 5. Of Ethsl 


6. Of VolatUe oUs 


7. Of Fixed oils . 


'-. 1. Stearine 


2. Elaine 


3. Cetine 


4. Phocenine 


5. Bntyrine . 


^^^^K^^Bt^f ^^^1 

^H piui ^H 

H Smx. 7. & HMiui 860 H 

^1 7. ClMleoieriiui 

360 B 

H Sect. 8. or Biuimca* . 


^^^^_ 1. BiliBniiiotiB oits . 


^^^H S. Propt-r tittumena 


^^^^■■P* Of Skcoxdahv CoMrniTKoa 

377 ^H 

^^^HJWI. Oxygen scmI Mill* 

^^^H Seol. 1. 6>lta of aRununia 

379 ^^M 

^^H S. SiJta of PMHh 

401 ^^M 
4-12 ^^M 

^^^B 3, 8>lu of ioda 

^^H 4. SnllB of litltw . 

470 ^H 

474 ^m 

^^^1 S. Sdlbt of buytn 

^^^B 6. Salts of rtrontian 

495 ^^1 

^^^B 7. Salta of lime 

^^^H 8. SalU of tnn|{iiMb 


^^^H 9. Sail* of alumiiiA 

639 1 

^^^H 10. Satu of glucina 


^^^K 11. SalUofylim . 


^^^H IS. 8*lu ofpnMDxiilL- of ocrinBt 


^^^B 13. Salts of peroxide of iwriuin 


^^^H 14. Salta of tircjoain 


^^^1 15. Salts of Ihorina 




^^^1 16. 6a{ta of prot4yxi<ti- of iron . 

^^^H 17. Saha of peroxulo of iraa 


^^^H 16, Salts of protoxide of mangiuuwe 


^^^B 19. Salta of aeaqui-osidv of inanguiAM 


^^^H SO, 6>lia of protoxiilu i>f mcke 




^^^H m. Salts of protoxido of coImI 

^^^^P 23. Salts of oxide of xinc 


^^^B 23. Salts of oxide of (sdniiun 

^^^H 24. Salln of protoxide of l«»d 


^^^B 25. Soils of protoxide of tin 


^^^H S6. Salts of peroxide of tin 


^^^H S7. Salts of bUvk oxiit<^ of 4MppiiT 


^^^B 56. Salts of suboxide of copper 


^^H S9. Salts of oxide of bisTOuth 


^^^^k 30. Sails of tuboxide of mercury 


^^^H SI. Salta of oxide of mercwy 


^^^B Si. Salt* of oxide of Kilver 


^^^B 33. Salts of peroxide of gold . 


^^^B 34. Sidu of peroxide of pJatiniuu 


^^^B 35. Sails of protoxide of pJatintun 


^^^B 36. Salts of oxide of jialladitun 




Sect. 37. Salts of peroxide of rhodittm . . . 720 

36. Salts of protoxide of iridhim 


39. Salt! of oxides of oanuam . 


40, Salts of oxide of telloriiun 


44. Salt! of white oxide of anenic 


42. Salts of protoxide of antimony 


43. Salts of protoxide of chromium 


44. Salts of protoxide of nnniom 


45. Salts of peroxide of mwiium 


46. Salts of protoxide of molybdennm 


47. Salts of deutoxide of molybdeniuu 


.48. Salts of iiiiilybdii: acid 


49. Salts of toDgstic add 


50. Salts of columbic acid 


.51. Salts of titanic stud 


52. Compound oxygeu add salts 


Class II. Chlorine add salts 


SecL 1. Of muriates and chlorides 


2. Of chtorO'Stannntes . 


- 3. Of rhloro-hydrai^rates 


■ 4. Of thloro-aurnlPB 


. 5. Of (Jiloro-plntinates . 


• . 6. Of chtoro-palladiates 


. 7. Of chloro-rhodinteg . 


8. Of ^liloro-iridiates 


9. Of chloro-Dsmintes . . 


Class III. Bromine acid salts 


SecL I. Of brumides or hydro- bromat«8 


2. Of Iwtimo-hydrai^tyratefi . 


Class IV. Iodine add sslta . 


SecL I. Of hydriodatee and iodides 


. 2. Of ioiiij-^tiiiiiiiitcs 


. 3. Of iodo-pluinbat«s . 


Class V. Flnorbe acid salts 


Sect I. Of fluorides or floates 


. 2. Of flno-bonttea . 


3. Of fluo-hilicute« 


4. Of Auo-inolybdates . 


5. Of fluo-tungstatea . 


6. Of fluo-chromatcH 


7. Of fl no-col iimba tea 


8. Of fluo-tiCaiiiat«s 


Class VI. Cyant^rco >*=i*l aalts 




Sect. I. Of cyanodides and hydro-cyuutea . 867 

S. Ofcyanatei 872 

a. Ofcymnurates 875 

4. OfftOnuiutes 876 

5. Of mlpho-oyanodidea and hydrocolpho-cyanatea 886 

6. OfbuDlpho-ejaaodidM .... 890 

7. Of praniatm or forro-cyanodides 890 
CI.ASS VII. Sulphur add ralta 900 

Sect 1. Of nilpbo-hydnUM 901 

2. Of bunlpho-carbonates .... 905 

3. Of mlplio-uuiiiateB 910 

4. Of nilpho-Bneiiitea 9S0 

5. Of faypoealpbo-aTBenites .... 927 

6. Of nilpho-molybdatea .... 928 

7. Of hypennlpho-inolybdates ... 934 

8. Of mJpho-tiuigstateB .... 996 

9. Of Hulpho-teUtmtei 941 

10. Of suIpho-Butimoniates .... 943 



■t the term primary compound^ u meant a combination of two 
more aitnple bodies with each ot]ier. 'I'lni.t [lotath is a 
primuy compoiind, l>elng corap<)«c<I of pottunwn und oxygen 
■nled toother. Cytmogm u another of these compounds, 
beinp oonpoMd of earhon nnil azvte united in definite propor- 
doM; aa is also arsenic nriil, which is u definite compound of 
«r«nic and o^ym. Atmuet cverj- one of these primary com< 
pounds have been notieed at least tu the first part of tliit work, 
b which almost all the known direct combinations of tlie simple 
boi&a with each other have been noticed. Bnt it will be 
nN]UMicc in this second part to treat of the mo«t important of 
Ihem in gmter detail tluui could be done with propriety white 
Wllim of the simple bodies. Now nil the primary compounds 
Hbnallf divide themselves into three classes, luunely, acidt, 
nUaHo OT basea^ and neatrtds. These tliree classes will be 
detcribed ill succession in the three following chapters. 




Br odd at present is nndenit«o<l a substance, which has the rMtmitoB tt 
property of oomhiiiinK with and neutralizing alkalies or bases. 
Formeriy It was considered as requtHile tliat bodies, in order to 
hf Umg to ilie dttsi of aeidit, should have a sour taste, »hotdd be 
itlilblr in water, and Atliould liiive tlie property of reddening 
n||;etable blue colours — anil these pr«(>crtic« do indeed belong 
to •ante of the moat common and powetfUl acids ; but iJiere are 
nilova acids wliich li^ive ni> Uste, and which are not sensibly 
whible in wster, nnd ttume which are incapable of altering the 
ocilaur of the most delicuto vegetable blues. All Uie aci<l9 
vith which we toe at present acquainted are compounds. 

II. u 


Chip. I. 

Lavoisier endeavoured to prove that oxygen constitutes an 
psttcntiul conslitiicnt in tlioin all. And tlii* opinion holds pood 
iinth till* jfrcater nmnbiT of acidn wliicli eliemiats were acquaint- 
ed with ill hln time, though not wit)i tlie whole of them. 

It is now known that not merely oxygen, but all the other 
simple gupporfers, namely, chlorine, bromine, iodine, and fluo- 
rine, are capable of forming aeids, by uniting with sevcntl of 
the iicidifiable bases, and indeed also when they unite with 
Hercnd of the alkaliflable ba-tes; especially thosie IH-Ion^in^ to 
the last family, and deAcribe<l imder tlie nunic of noble mttais. 
In fact the giciiter number of tlic incUds belonging to thb 
ftratly, are scarcely entitled to the niiine oi iilkulijialile bases; 
though they hardly pu«i4e!W sufficiently energetic elmractera to 
cntiUe (heir compounds, if wc except their chlorides, to he 
considered as acids. 

BesidcK ttie live !>upporter!4, cj'anogen, sulphur, «eK-Tiiuni, 
and tellurium, have uUo the property of forming ucids when 
tliey unite with tlie acidifiabic bases. Indeed it is not impro- 
biible tliat this property may belong to most if not to the whole 
of the acidifiahle bjL'.es, though at present it lias only been 
ascertained to hold with respect to those which have been just 
named. Thus it appears that the acids at present known may 
be divided into 9 classes, namely, 

1. Oxygen acids, 6. Cyanogen acids, 

2. Chlorine acids, 7. Sulphur acicU, 

3. Bromine ncidx, & S<'Icnium iidfU, 

4. Iodine acids, 9. Tellurium iicidtt. 

5. Fluorine acids. 

These 9 classes of acids will be described in succession, so 
far as the present imperfect atale of llie science will enable us 
to go. 



Tlie acids which contain oxygen as an essential constituent, 
have been longer known and more carefully examined by 
chemists than those which constilute the other eight classes. 
This is probably ihe reason why they are at present so much 
moro numrroiij^ than all the oilier aeidit put togctlier. There 
ran be no doubt tliat tlie chlorine iiei«l«i an*! tliosc belonging 


to «cl» of th* Other cUwses, will increase rery much in number 
u th« Mience extends. 

Tlie oxy^n wiAa are of two kituii. Some contist of oxyg:en 
unitrd to a singltf oHitifiiililr I»im- ur a single Hupporler. Thus 
mjphurie uoA fe a oitmpoiind <if mtp/tur and oxj'gen ; rarAontc 
aad of carAom and oxygt-ii j »nd bromic acid of hrmniw and 
oxj^n. But thpre ar* a considerable number of oxypeii ncida 
b wliicb the on-gen is united at once with two niid tomctimos 
with UiriH- buftCA. Thus aefiic acid h a conipouiul of oxygen, 
evboui and hydrogen ; while uric ucid is ■ compound of oxy- 
gen, carbon, hydrogen, nnd iixotc. This second set of acidii is 
rery numerous. They either exist rt<»dy formed in the vegeta* 
bl« and animal kingdoms, or they are formed from vegetable 
aad animal bodies by certain chemical processeti. We must, 
i^enSom, HulHlivide die oxygen acids into 

I. Addn with a single baw. 

8, Acids with a cam[)oun<l Iasc. 

The fml of these divisions iiiclndes the most important of 
tlMwe acids that are employed as instrument* of chemical 
binwiigadon. But there arc also licTcral of the acids unih 
compound bases that are nearly indispensable in a chemical 
bbomtorjr* for itome of the most fretjucnt and useful processes 
which the pnictical clif miiil hit<t occanion to perform. These 
rfmona make it tndispctiMble for ns to take a view of these 
acidi Id this pan of the work. 



The oxygen acids witli n 

simple base, so far as we are at t.i.i.o(.u«. 

pTCMDt aMpiainied with tliem, amount to about 36. Their Jhu"**" 

■HUS arc as follows: 

1. Perchloric, 

13. Hhosphoric, 

a. Chloric, 

14. I'yropliiwphoric, 

3. ChloroiiK, 

15. Phospliutuus, 

4. Bromic, 

10. Hypuphosphorous, 

5. Iodic, 

17. Sulphuric, 

6. Nitric, 

16. Sulphurous, 

K 7. Nitn>iis, 

19. HyituHulphurou.t, 

^ 8. Ilyponitrous, 

20. Subt«ul|iiiuroius 

9. Carimnic, 

21, Hyposulphuric, 

10. Oxalic 

2*2. Sclcnic, 

11. Boracic^ 

33. Selcnious, 

12. ^de. 

24. Telluric 



2fi. AiMntc^ 

26. Arsenioiis 

27. .Anlinioiiic, 
2& Aiitimuiiious, 

29. Chromic, 

30. Umnic, 

31. Molybdic, 

QQ, Tungfitk, 

33. Columbic 

34. Titaiiic, 

35. MtingAnesioiis, 
06. Mnntfiinefuc 

I shall take a inew of each of these ncida in Kuccesaton. 


Chlorine atid oxygen unite iu thnrc different proportions so 
as to form adds. These are 

Chlonan. Oxjtio. 

1. ChloroiiM ;icid 1 atom + 3 atoms 

2. Chloric odd 1 +5 

3. Percl Joric acid 1 +7 

Thcw throe acids have been described in ^'ol. I. p. 66 ; the 
first under the name oi quadroxidr. a/ chhirine. It has been 
generally considered as an oxide, bccuii^c when we attempt to 
unite it with a base, it undergoes deoompMiiion, However, 
if it be placed in contact with an alkaline bwu- in its nascent 
Htate, 8 comliiiuition l4il(cs pluce, and a dihritf is formed ha\-ing 
a peculiar and acrid taste similar to that of the ac!<L These 
salUt luive the property of destroying vegetable coloure. 'Iliere 
can be little doubt that Von Stadion's analysis is accurate, so 
that it is a compound of 

1 atom chlorine 
3 atoms oxygen 




and ilA atomic weight is 7-S. 

The &cts respecting chloric and perchloric acids Mated En 
the first volume of this work, constitute every thing hitherto 
ascertained respecting them. 

The drcumslance of two substances, both of which are so 
strongly negative, ta oxygen and chlorine, uniting together^ 
seems at first aighi rather incompatible with the electric theory 
of chemical affinity. I have endeavoured to obviate this diffi- 
culty in tlic Introduction to tl»is work (Vol. I. p. 39). The 
affinity between the oxygen and chlorine ia obviously weak. 
Hence heat which seems to increase the intonKily of the nega- 
tive electricity of chloriue, easily occasions a di.-oomposition of 
these acids. 



TUr oxygen ackix of hmmine an<l itxline liitherto oWrved 

I are only I ncid for racit of tkc-ix; liodieH, coiolitutiiig hTvitir und 

I loirfH- arirl, miMlogoiw iw tbcir naiDf 8 imply Co chloricaeid. Their 

prapertieft bar* been alreai^y described in p. 74 and p. 8i! of 

\b« ftnt vuluiae of tliis worii. I do not notiee liere llie iodou3 

ftrid of Sementini, nor tlie bypiodoiiH scid of >liichef licli, because 

I I buve already state*) all the (aeU rei^>ceting these suppoaed 

acids with wliicb I am ocquainU-d. Bromic acid is a com- 

i pound of 


^^ 1 atom bromine 

^^^^^^^ 5 atoms oxy^u 

^^ -aad iodic 




■wd iodic add of 

1 atom totline 
fi Mouu oxygen 




^ lodoi» acid (If it exiM) ought, from analogy, to be a com- 
pound of 
^K I atom Iodine 15-75 

^^^^^_^ 8 atOBW ox)'geu 3 

H Asotc 

^P thrva ad 
r nitrouM a 


escnoK III.— OF thk acids of azote. 
Asotc and oxyeren oombino in tliree propo^tionf^ forming the 
thr*a acidn whidi Imrc been culled nitric, nitrous, and Aj!po- 
mitreiu adds." 

* VbcB the IVeacb chcmiati contrtred thoir new chemical nomenclniurc 
■ 1797, a bue wm Mippoicd f o be nkpablv or tinUing onl^ with two iloscit 
<f OSjrfM, tni of fonntng two Mtiik. Tliey dittinguithcil llic«c ncida by 
naddng dw aHil conuialef; mo«t oaygcn terminnlc in u-.and tlio one con- 
iaUi| Immc la oat. Tim* mtric acid oonisina moat oiygcn, and nitiwt 
mU itmL h WW afterwtxiU diacoveiwl tliat in tome ciuca wid* exist cun- 
tiUi^ le» oxygaD than tboie b out. Thnc arc dittinguished by preTiilag 
I the aylUila Ajgun, u ^jipimil m u. The mode U still impcrlect. for mnue 

baie* unUe wtlfa fimr or even five doae* of oxygen, and (oim (out or even 


g Ct>ti..L 


1. Nitric Afid. 

Thi;! acid, which is one of tlie most important instriinipntR of 
invcsligBtion of wliich (he chemiitt U possessed, wan certainly 
known to Geber, an Anibian ciivmist of tlio Ttli century, and 
the autlior of the first puri-ly chpmiad work with which we 
are ac<|u.iiiit(-d. It is always procured from salljiftrr. or nifre, 
at salt wliich forma spontaneously on the surface of the enrUi 
in most parts of tlie worhl. 'I'lic saltpetre, made ubc of in 
this country, is imported from India, where it is collected in 
great (jiiaiitities from the aoil. It is nf^erwards refined in Great 
Britftin, and nuule fit for the manufiicture of ^npowder, in 
wliich hy far the gn-utest jjurt of the Niltpotrc imported is 
expended. Saltpetre is a compound of nitric acid and potasiu 
If sulphuric acid be mixed with it, the nitric acid is discngag^cd, 
and may be distilled over from a glass retort into a receiver. 
Nitric acid cannot bo ohtnined free from wat«r, but tlie sulphuric 
acid of eommerce nlwny* contains a sufficient (junntity of water 
to Kupply the nitric acid with tliat csMcntiul element. 

To prepare nitric acid, the best way is to put 1275 parts of 
saltpetre info a retort, and to pour over them 12'25 parts of the 
sulphuric acid of commerce (of tlie specilic gravity 1-A47). 
Lute an adopter to the beak of the retort, and fit ilie extremity 
of tlie adopter into the mouth of a gloss receirer amply large 
cnoufrli to liuld all the nitric acid which «-ill como over. The 
retort being placed in a sand bath and a lire kindled below it, 
the mLxture of nitric and sulphuric acid speedily becomes li<juid, 
and the whole nitric acid may be dUtiUed over at a moderate 
tempemlure, an<l witliout any \a»». The unhydrouH nitric add 
contained in 12-75 parts of nitre is 6-75, and tin* water con- 
tained in l*2-25 of snlphnric achl is 2-25. But if the heat applied 
be nut too great, one-lialf of this water remains in the retort 
united to the suit of potash formed by the sulphuric acid, so tliat 
the (juantity of nitric acid obtained should weigh 7'U75 parts, 
and its specific gravity should be 1-55, But in general a little 
more tlinn one-half of the water comes over, 6o that the specific 
gravity of the nitric ucitl olititined k rarely so high as 1 -h. If 
the heat applied be u little too high, all the water in the sulphu- 
ric acid comes over witli tlie nitric acid. The (|iiantity of nitric 
acid obtained in tliat case is 9 parts, and its specific grainty is 
l'485r). 'ItiiH ii* by far the movt common strength of nitric 
ncid obtuinet) by thiM process. 

If instead of 12-25 of sidphuric ncid we mix only 6-i25 porta 


Willi 12*75 of nitre, only two-tbirds of tlie nitre m tlooomposH 
and citmoH aver iiilu the receiver, comt)iited u-ilii nil the n'atcr 
in tliv siilptiunv »cicl. \\')ii-i) tliis [HrrtioD bos passed over, tlic 
miiar mutter in tliv riMort Iwcomra tKilid. If wo increase the 
beat BO as to liquefy this wdt, it swells up in consequence of the 
deeoai[Knitiai) of the remaining portion of nitrie add, which 
cannot be tUstilled over, because there 'm no more water with 
which it (niti combini;. It ih tit^oIvinI intodvuloxidc of Euote iind 
oxygen link's. The dviitoxidc of axote is ulMorbcd by the nitric 
acid ulreuily di^iUe^ over, to which it commutiicatcs a red 
colour, and the property of fuming Htrongly when exposed to 
the air. In this stale it is distinguished by the name of /'uming 
nitric aritL The oxygen gas makes its escape, of it may be 
collected in a convenient pneumatic apparatus. 

The iicid obtained by thk« proce-ts Iuls a yellow colour; but 
it may bi- tx-mk-rrd c«ilourlvss by simply raitiug it to tlu- boil- 
ing Imipcntlurc in u retort, taking rare to remove tlie receiver 
while the add is boiling hot, to prevent the dcutoxidv of uzotc 
tbtia driven ofT, from being again absorbed as the acid cooU. 
If conunoo nitre tia-n lH>en employed, the nitric aciil obtained w 
alwnjn mixe<) with some muriatic. Nor can nitre be quite 
freed ftom all traces of common salt, tliotigh re])eattsUy cryx- 
taili/ei). Hut if we put tlio impure nitric add into a retort, luid 
diirttl off ulwut one-tliird of it by rather a slow fire, the rcnuiin- 
ing two-thirds in the retort will be quite pure, all tlic muriatic 
add liaving passed along with the acid distilled over. This 
metiiod, fintt pro|V(JM-<l by Latssone and Coniette,* I have been 
in the bubit of foUoHnng, and easily ubtjun by means of it pure 
nitric add; wliile the portion distilled over answers all tlic 
BUtaeroiM purposes to which a mixture of nitric and muriatic 
aads is tuually applietl. 

Nitric add thus prepared b a liqaid colouriess as water ; but Pn^Mic^ 
If we expoAe it to tl>e direct rays of the son, or even to tlie 
l^^t of day, it girr^ out oxygen gas, and soon .li^umett a yellow 
colour. It alworbs deutoxidc ofazoto with avidity, and becomes 
first yellow, then red, and at lu«t brown, and so volatile tliat a 
very moderate heat converts it wholly into vtipour. 

It ha.*! a peculiar smell, and gives out u while smoke when 
expOM'd to the air. lis taste is intensely sour, it reddens vege- 
table blues, an<l corrotU>» aiul destroys animal and vegetable 
mbetances with great energy. Hence it u often applied by 

.• Mem. Pw. ITfll.ihei^ 


°'*r- !■ siugeonB to flt conditioned ulcers as a cansdc, and wben so 
^plieditanswen better, and gives less painwhen strong than 
vhen diluted with water. 
krbKIi- It liBB a strong affinity for water, and cannot be obtained tree 

&om that liquid. When the concentrated add is exposed to 
the air, it absorbs moisture from the atmosphere. The follow- 
ing table shows the specific gravity of various atomic combine 
tions of this acid with water.* 


AtCtM ct 
















































1-2 173 




pi*^ The boiling temperature of this acid varies with its strength. 
The following table drawn up by Mr. Dalton, from his own 
experiments, shows the temperature at which acid of different 
densities begins to boiLf 

ap. gniltjgf udd. 

1-54 ... 175 



















• Hret Principles, i. 1 14. 

f New System of Cbenuol PhUoBo|A;, ii. 356. 









r p »« from this tslilo tliat the iKiiling p<niit of acid of the 
specific gravity l'42,oraci4icom))OHe<l(if 1 atomuciH + 4 atoms 
water ia a maxiinuin or '24ti^. 'llii'^ l>oiliiig point of uc'ici eittter 
stronger or weaker tiiiui tlii* U lower. 

The acid wbivli ucciin in commcrM undvr tlic name of atjua- 
fortu or single nitric acid, is obtaitiMi by distilling a mixttirv of 
l^tre ml itiilpluitc of iron in cast-iron retorts luti-iitoUrgo green 
ghw reocivBis. Ii is colourless, or has only a very Hgbt tUwAn of 
. jreilow. The specific gravity of what is usoally made in this 
country is about 1*22, and it contains about GI per cent, of real 
acid. It rarely or never i-ontuin* any ir«Mi ; but i^ never free 
from mnriallc acid. 

Mo«t combuvtitilc subetances decompose tlib acid ; but it does ^^,;^^ 
not act upon ciuLrcoul ujid sulphur unless llie tempenitiirc be 
elevated. If a piece of charcoal be ignited and thrown into 
oHioeotnUed iiitric acid it ooiitiiiuea to burn with great violence, 
giving out red vnpoun. \V1icn boiled upon sulphur it gradu- 
ally converts it into stilphnrtc iicid. Phiwpliorus wlien tlirowa 
into ootuentrated uitrtc acid catches fire aiul bums witJi much 
aplendour. On iron concentrated nitric ucid does not act 
instantly, hut if we derate the temperature the action begins 
suddenly ai>d becomes extremely violent ; mucli heat being 
evolved, aiHl e\-en light it is said; though this has never hap- 
pmed in my trial*. It ikIk ul-io with great violence on zino, 
tin, eopper, and matiguncTW. Mercury, silver, cadmium, bis- 
muth, lead, cobalt, and nickel, are dissolved by it rapidly, uud 
with cffervesoenoc. Vpoi] gold, platinum, palladium, rhodium, 
indium, and osmium, it either does not act at all or only very 
feebly. Concentrati'HJ nitric add sets fire to varioti-t volatile 
mIs. Ilie combustion of oils by this acid wa.« fintt t-Ucen notice 
of by Borricltius and Slurc ;" but it is proituble that Hoinberg 
communicated it to Slare. In order to set fire to the fixed oUa* 
it must be mixed with some sulphuric acid ; die reason of whidi 
Mens 10 be, that these oils contain water, wliich must be previ- 

• l>hU. TrsM. Abr. ii 6A3, and liL 603. 



oiinly rcmovt'd. The sulphuric add comhiiion with t)iii* water, 
aiid iillows the nitric acid, or rather the oil and nitric acid 
lci|ri-t]ier, to act. The diying oils do not rc<jnire any sulphuric 
acid : they have been boiled, and consequently deprived of all 

Dilute nitric acid ha.<< tlie property of giving a yellow colour 
to vegetable ami aiiiinul Nuhstnnces. lu this way it dyes the 
cuticle, and the yellow colour liwoinea orange when waslied 
with soap, and remains indcliliK- till the stained portion of the 
cutick' lie removed. It \» cmploywl to give a yellow border to 
tliebhieor green woollen cloth used in this country for covering 
lables. Many vegetable uad animal subi^hniceH when digested 
in it urv convcrleil into oxalic acid, malic lu-id, uirboiiie acid, 
suberic acid, wax, or fatty matter UJ(c tallow, and Hometimes 
nUo into hydrocyanic add. 

It has iheproperty of neutralixijtgbases, andforminji^achiu 
of wdts called nitraten. 
oinrniiiim. The first step to tlie knowledge of the constituents of this 
add was made by Lavoisiur, who proved by dtreet t>xperimvnt, 
that it might be resolved into deutoxide uf axot« and oxygen 
gas ; and thut these two ga«rM when plneed in contJict, imme- 
diately reunited and formed nitric add. He conduded in cod- 
sequence that nitric add is a compound of dcutoxidc of azote 
and oxygen ; and he even tried to delermine the proportion of 
the two constituents, but the result obtained does not constitute 
a very near approximation to the trntli.* Mr. Cavendioli 
showed tlmt when azotic and oxygen gases are mixed, and elec- 
tric ftparlcK jiiLHsed through the mixture in a glft.''s tube staiuling 
ov«r potash ley, the two g:i»e» iniite togetlier and form nitric 
add, which grudunlly satnntle« the pottudi, and converts It into 
nitre. Hence it followed that the true constituents of this acid 
are azote and oxygen. From tJie proportions of tlie two gases 
wliieh disajipeared in this experiment, it appeared that nitric 
acid was a compound of 

1 volume azotic gn.s, 

2 volume* oxygen gas. 

and with this the analytical experiments of Bertliotlel agrced.f 
But it hiLt been fully established by numerous experimentn, 
among otbent by several of my owii^j: tliat the true con^titHcnts 
of this acid arc 

•Bton. Par. 1776, p.673. t Mcro.D'Arcuril.iii. 

t Pint Priii«plci,t. loa 



1 volume azotic p;^ 
2j volumes oxygvn gas. 


1 aiom azote 
b atoms oxygon 

Bd that its atomic weight is 6-75. 



a. Ht/ponitrovM Acid. 
In dw short account of liypnailrous aei<I wbich I luiv«> ^ ' 
ghren in the first volume of ttiU work (p. 127), I tiave Htatccl 
llwt it docs Dot seem citpiible of exi.-<ii>ig ext-opt in combiiiatiuii 
wilb a base. How«v«>r, M. Dulong has sliown iliat this opinion 
M not well foundnl. Ho misi-cl lofrotlicr 4 volumes of dent- 
oxi(U> of iuat<', mill 1 volume vf oxyt>;<'n ^%, unA oxposcil tlic 
nUture to tJic cold produc^^d by a frcoKing mixture, it coti- 
dtnscd into ndeopg^on liquid, exceedingly volatile, and losing 
tlw liquid stale wlieu the cold was withdrawti. Now as dout- 
oxide of azote is a compound of equal volumes of axote and 
oxyf^n without any coiMlonnation whatever, it u evideul that 
this grevn liquid wiu a compound of 

^K S volumoH nzotic git«, 

^H 3 volumes oxygen gn«, 

^H or (wbidl ia die Rainc tiling) of 1 volume utotic un<l I \ volume 

^B oacygtti giu. Thi« is equivalent to 

^H 1 atom azote 1*73 

' w(ii< 


wbich is (lie eompn«itioiiof hyponitrousacid. Thus it (ippcars 
from Duliing'n experiment, ttiat liyponitrous acid is capable of 
existing uncombined nnth a base. 

Tliis acid when in contact with air mixes with it and becomes 
a r««I vaponr, which is not again condcnviblo witiiout t}ie appli- 
nvtion »f an intense coh). When this acid is mixed witli water 
it undergoes n pjirlial decomposition. Dc«toxid« of azote is 
given out with a ntnsng effervescence, and there remains a solu- 
tion of nitric and hyponitrous acid in the (rater. The same 
decomposition takw place when we attempt to combine tliia 
acid witli a bi»e- But it is easy to obtain hyponitrites by 
cii>uble dccompoaition. The manner of procee<iing h, to boil a 
mixture of nitrate of lead and metallic lead in water ; ii dihy- 
poiiilritc of lend b formed. If this hyponitrite be mixed with 



Cnnilil or 


Lavoisier ciidravour^d to prove tliat oxygen oonstitiitos an 
(■Hsential comtitucnt in them uU. And tliis opinion holds g'ood 
witi) the greater numWr of ucidswiiicli chemists were acquaint- 
ed with ill liiH time, though not with the whole of thcin. 

It is now kiiouii tliat not merely oxyj^en, but nil tht^ other 
simpk- mi'iiorterii, namely, chlorine, hromine, iodine, and flu*>- 
rinc, arc cap»ble of forming aciils, I>y unitiiij^ with several of 
the ncidifialilc Uises, and indeed alno whiin they unite with 
aeveral of the nlluililiablo \iivws ; expccially those belonging to 
the last family, and described under the name of luAle metaU. 
In fact tlie greater number of die ineUils belonging to this 
fomily, are scarcely entitled to ihc name of alkali fiaUt bases ; 
though t}iey hardly possess sufBciently energetic diaraclers to 
entitle their compounds, if we except their chlorides, to bn 
considered as w:\A». 

Besides the five siipjiortcrs, cyiinogcn, sulphur, selenium, 
■uid tellurium, have also the property of forming acids when 
they unite with tlie acidifialile bases. Indeed it is not impru- 
bnble that ibis property may belong to most if not to the H-hole 
of the acitlifiiible biVfn, though at prewnt it ban only been 
aftcertiiined to hold witJi respect to tliose which have been jimt 
n»ine(L Tbits it appears that the acidtt at present known may 
bv dividetl into 9 classes, namely, 

1. Oxygen acidii^ 6. Cyanogen acids, 

&. Chlorine acids, 7. Sulphur ucids, 

3. Dromine acids, 8. Selenium iicids, 

4. Iodine acids, 0. Telturium acids. 

5. l-'luorine acids. 

These 9 clause* of acid« will be described in vuccesNion, ko 
far as the presont imperfect state of the sdence will enable us 




Tlie acids which contain oxygen as an ejoential constituent, 
have been longer known and more rarefully examine*! by 
chemists than those which constitute the other eight classes. 
I'his is probably the reason why they are nt present so mncli 
more numeroii.t tlian all the otJier adds ]>iit together. Tliero 
eaji be no doubt that the chlorine acids, and Uiose belonging 



rto «acli of the other classes, will increase very nach in number 
w the science extends. 

The oxygen acids are of two kinds. Some consist of oxygen 

Baited to a tungle aciilifialjle base or a Miigic supporter. Thus 

tulfAuric nind h a oumpoimil of sulphur nnd ox)'gi>n ; carbonic 

acid of carbon nnd oxyp^-n ; :uui bromic neid of bromine and 

mjgvru But there are u considcrahlc number of oxygen acids 

ill vKicb the oxj-gen is united at once n-ith two and Mimoiinies 

with three bases. Thus actJic acid in a compound of oxygen, 

cuboOt utd hjrdrogeo ; while uric acid \» a compound of oxy- 

, gen, cnrhon, hydrogen, and azote. This M-cond set of acids is 

[Tery niuncrotu. They either exint ready formed in the vcgeta- 

[hle and animal kingdoms, or they are formed from vegetable 

imai animal bodies by certain clicmica! processes. We must, 

[ tli«rvfurc, suljdittde tlio oxygen acids into 

1. Acid* with a single base. 

S. Ac](b vith a compound Ixise. 

The first of tliew diviHionx includes the most important of 

IthoM acids that are employed a» iiii^itniments of elu-mical 

[ InreM^fatton. But tiicre are abto scvcml of the itci<ls with 

I BonpoQiMi bases that are nearly indispeuKable in u clicmicul 

laboaMory, for some of the most frequent and iiM-fnl processes 

wUdt the prActical chemist has occasion to perform. These 

reasons make it indi)<p«iiKal>le for us to take a view of these 

•cids in this part of the work. 




The oxygen acids with a simple base, «o far as wc are at nprienfiim. 

present acqttointed witli them, amount to about 36. Their ilc'i,^*'^ 

mnes are as follows : 

1. I*erclih>ric, 

13. I^osphori^ 

2. Chloric, 

14. Pyrophosphoric, 

3. Chlorous, 

15. Phosiihorwus, 

^m 4. Dromic, 

16. Hypo])ho«phorous, 

^ 6. Iodic, 

17, Sulphuric, 

6. Nitric, 

18. Sulphurous, 

7. Nitrons, 

19, IIvposulphiiToiis, 

8. Hyponilrotw, 

20. Subsiilphuroux, 

9. Curhonic, 

21, Hy|>o«ulphuric 

10. Oxalic 

22. Selenie, 

1 1. Boracic, 

23. Solenioiis, 

IS. Silkic, 

24. Telluric, 


"^i 25. Arsenic, 

26. Areoiiious 

27. .Antimoiiict 
128. Antimonioiu, 

29. Chromic, 

30. Uranic, 

SI. MotylKlic, 
32. Ton^tie, 
83. Columbic, 
34. 'niaiiie, 
85. MungoneHioiw, 
36. MBnganvftic 

I shall tako a view of eacli of tlie«c iicids iu succcttsion. 




Chlorine and oxygen unite in Uiree different proportions so 
as to form adds. Tliese are 

CtOorUit- Oxippa. 

1. Chlorous ncid I atom + 3 atoms 

2. Chloric add 1 +6 
9. Perchloric aoid 1 +7 

These three odds have been described in Vol. I. p. 66 ; t1)0 
first under the name o( quadnxidt qf cJtltirine. It lias been 
generally considered as an oxide, because when we attempt to 
unite it with a base, it undergoes decomposition. However, 
if it be placed in contact with an alkaline base in it>i iiAAcent 
state, a combination tiikes place, and a chhriU is formed hitving 
A peculiar and acrid taste similar to tluit of the acid. TheJie 
talts have tlie property of destroying vegetable colours. There 
can be little doubt that Von Studion's analysis is accurate, so 
that it is a compound of 

1 atom chlorine 
3 atoms oxygen 



An<l !t8 atomic weight is 7-5. 

'Hie lacts respecting chloric and perchloric acids stilted in 
the first volume of this work, cousdtule every thing hitherto 
ascertained retipectiiig them. 

The circumMmice of two substances, both of which are so 
strongly negative, as oxygen and chlorine, uniting together, 
scens at first sight mthor incompatible witli the electric theory 
of chemical ik£Snity. I have endeavoured to obviate this diffi- 
culty in the Introduction to this work (Vol. I. p. 38). The 
affinit}' between the oxygen and chlorine is obviously weak. 
Hence heat which seems to increiwe the inten»ily of the negn- 
live electricity of chlorine, eusily occasions a decumposilion of 
these acids. 



Tht^ Axygeii actdfl of bramine and iodine liit}i«rto otwerved 
■K only I iirid furi'itcliof tlw«eliodi«t«, coiiKtitulin^frrioniKBnd 
MNArBcid, nnalt^iMitxttifiriuunps imply to chloricactd. Their 
properties linve been already dracribed iii p. 74 and p. 82 of 
the tint volume of this vfoiit. I do not notice here the iodous 
oriidor Semeotini, nor the hypiodoiu acid of Mi tcberlich, hecwne 
I hum already stated all the facU respecting (lic«4' HiippoMCl 
•cJds with which 1 am acquainted. Bromtc arid is a cotn- 

poUIMl of 

1 atom bromine 


^^ 5 atoms oxygen 




iodic acid of 

1 atom iodine 


5 atgnu oxygen 



Ifldous acid (if it exist) ought, (irom analogy, to be a com- 

I atom iodine . . 15*75 

3 attnna oxj-gen . . 3 

Dt*. 1. 



Axote and oxyt^n combine in three propOTllunj«, forming ih.9 
thrf* acid!) whidi luivc tx-vn citk-d nitric, nitroua, and hgpo- 
mtnma acid*.* 

• Wbcn ifae n«ich cfaeiauta oontrivad their new chanicnl nommclaiun; 
b 1T9T, B baw wm tappoicd lo be rapalilc of unking on\y with two J»fleii 
dl oaygca, Uti oi rormbig two adds. TIi<7 Jiatinguifthcd thcic acid* by 
(Mktng Uic »dil coataining moM oxygen temtinale in tr.and the one cor- 
taialaf lca*t in on. Thai Mrie acid ooiilainx most oxy^n, and nitrovt 
•eid IcMtf. It WW iftorwarda diftoovcrod tlml in iiomc cnsra acidi exist con- 
laiiMCf 1g«* OXjgcB than thote ia oii$. ThcJW uc dUtinfiuishcd by (vcllxing 
the (jIUiIm Ikgpo, m hj/p^nilrotu. The mode U itill impctr«ct. For some 
hwrn unit* with four or <rven five doaoi otoxj^n, nnd form four or even 


<*«»»■ I. Nitric Acid. 

tiMgrr. Thia leW, «-1iicIi is one of the most important instnunenta of 

inveaiig&tioii of wliich ibc chemiBt U possessed, wnt certainly 
known to Geber, an Arabian diemiHt of tlie 7th century, and 
tlic autlior of die first [iiirt-ly I'lii'mifia! work with which wc 
iiri- iKquainled. It in nluiiyM procured from saltpetre or nitrt, 
a Halt which forms spontaneously on tlic surface of the earth 
in most pnrts of the world, llie saltpetre, made »i*C of in 
diL* country, w imported from Itidiii, wlicre it is coiU-cled in 
^eut quuntiti(^« from the sail. It is aftenvard^ refined in Circat 
Britain, and made fit for the manufacture of ^npowder, in 
which by far tlie greatest part of die saltpetre imported is 
ex])en<led. ^alt])etri> m u compound of nitric acid and potash. 
If Rulphuric acid he mixed witli it, tlic nitric acid is disengaged, 
and may bo distilled over from a glass retort into u receiver. 
Nitricacidamnotbe obtained free from water, but (he sulphuric 
acid of commerce always contaiat a sufficient quantity of water 
to supply the nitric acid with that et^ential element. 

To prepare nitric acid, the best way is to put I2'73 parts of 
«alt])Ctre into a retort, and to ))our over them \'2-'25 ])art« of die 
sulphuric acid of commerce (of the specific gravity l'847). 
Lute an adopter to die beak of the retort, and fit the extremity 
of the a<lopter into the mouth of a glaw receiver amply large 
enough to hold all the nitric acid which will i-oine over. The 
retort being placed in a siiiid bitth iitid u firo kindled bolovr it, 
tlie mixture of nitric and xuljihiiric acid speedily becomes liquid, 
and die whiih- nitric acid may be distilled over at a moderate 
temperature, and ivithont any loss. The anhydrous nitric acid 
contmned in !ii*7i parts of nitre is 6'7ii, and the water con- 
t^iedin 12"2ft of sulphuric acid is 2-*25. But if the heat applied 
be not too great, one-hall of this water remains in the retort 
united to tlie salt of potadi formH by Uie sulphuric acid, so that 
tlie quantity of nitric acid obtjuncil Hboiild weigh 7'87.'> parts, 
bikI its Npecific gravity should be 1 '55, I}tit in gcncnil a little 
I inorc than one-half of the water comes over, so that the specific 
gravity of the nitric acid obtained is rarely bo high as l*5. If 
tliv heat applied be a little loo high, all the water in the sulphu- 
ric acid comes civer with tlic nitric arid. The qtiantity of nitric 
add obtained in that rase is 9 ]>ar(s, imd m specific gravity 1$ 
1-4M5. This is by far the most common strength of nitric 
acid obtained by dib* processi. 

If instvuil of l'2"25 of sulphuric acid we mix only 6*125 parts 



with 12-75 of uitre, ooly two-UimU of tlie nitre i» (k*comj>OMd 
ind cdmciii over tiita (lie receiver, coml)iiie<) wiiii nil tliv uiitcr 
in tilt; sulphuric iiriil. M'IkUii this portion luut p»)>sv<] ort^r, tlie 
wUne matter in tlic rrtort becomps solid. If wv iucreuM the 
luAt M ati to liquefy ihLs salt> it su'clU up iit coiiiiequentc of die 
deeoQiposition uf liie reDiaiiiing portiuti of nilric aciil, whicli 
aunot be digtilled over, beoiuM: tlierv in no more vraler with 
whi«li it can combine. It i'^n^'Molved iiito<iciitaxi<leof uxuteund 
oxyg«n ^;as. The deutoxitle of azote is Bb«orbe<l by tlie iiitrie 
■ckI already distilled over, to which it conununirates a red 
colour, aiid the property of fuming strongly when exposed to 
tlie air. In (bis stale it is distiiigtiiiihcd by tlie name of fuming 
nitric acid. The oxygen gas makes its escape, or it may be 
caUwte<i in a convenient pneumatic apparatus. 

The acid olitaiiied by tbiii iiroceiu has a yellow colour; bat 
it may be rendered colourlexs by K!m]>ly nLi;<ing it lo the boil- 
ing temperature in a retort, taking care to rttmovc the n-eeiver 
white tlte acid id boiling hot, to prevent tlic dcutoxide of azote 
tbOB driven oif, from being again absorbed as the acid cools. 
If coounoti nitn' luLt been employed, the nitrie acid obtained a 
alwayit mixed with somr muriatic Nor can nitre be quit« 
freed from all traces of common sidt, thougb ropCiiledly crys- 
tallijceii. Dut if we put the impure nttric and Into n retort, and 
dbtil off about one-third of it by rather a slow Are, the remain- 
ing two-tbirdft in the retort will be quite pure, all tlie muriatic 
Kul having {nMeil along with the acid distilled over. This 
nwtliod, finrt propo«e<l by Lattsone and Cornette,* I hiive be«n 
In the lud>it of following, and easily obtain by meiui.i uf it purv 
nitric acid; while tlie portion distilled over nnnwerv all the 
numeroiu purposes ^to which a mixture of nitric and muriiittc 
acids U usually a]>plied. 

Nitric acid thus prepared is a liquid colourless as water ; but r»i«iicfc 
if vre ex|MMe it to tlie ilirect rays of the sun, or even to the 
light of day, it givexout oxygen gas, and soon assume:* a yellow 
colour. It absorbt deutoxide of o/ote with avidity, and becomeit 
6rst yellow, then red, and at last brown, and »o volatile that a 
ttry moderate heat converts it wholly into ^'apour. 

It lias a peculiar smell, and gives out a white smoke when 
expoMid to the air. Its taste is intensely sour, it reddens vege- 
table bluea, and oorrtKlen and destroys animal and vegetable 
tulnt an ew witli great energy. Hence it b often applied by 

.* Mem. Par. lTSt,p. U6. 





Burgeons to Ql conditioned ulcers as a caustic, and when bo 
Implied it answers better, and gives less pain w hen strong than 
when diluted with water. 

It has a strong affinity for water, and cannot be obtained free 
from that liquid. MHien the concentrated acid is exposed to 
the air, it absorbs moisture irom the atmosphere. The follow- 
ing table shows the specific gravity of various atomic combina- 
tions of this add with water.* 


AtoH at 




















































v*A The boiling temperatare of this add varies with its strength. 
The following table drawn up by Mr. Dalton, from his own 
experiments, shows the temperature at which add of different 
dendties begins to boiLf 

Sp; garttjottU. 


1-54 ... 175 



















• Pint Priaciplei, i. 114, 

t New System of Chemical Pliiloaophy, u. 355. 














We a«i- from UtU Uil>[c tb&t tbc Iwiliiif; point of ucid of tbc 
■pocifip ferity 1 -42, or acid composed <>f I Uom aci<I 4- 4 aloniii 
watu a maximum or 246^. The boiling point of nctd richer 
ttxvaget or weiikvr thiui Ha* in lower. 

Tbe Bcid which occurs in commerce under the aamc of ai/ua- 
JitrtiM or tin^ nitric acul, is obtained by distilling a mixture of 
niCKaadBulplk-iteofiTonincast-irouietortB lut^ tolnrgo^i'trn 
H^Hi rsceirsrs. It is colourleiui, or has only a very light ihudc of 
yeiiow. The specific gravity of what is usually made in this 
country is about 1-22, and it vontaiiw aliout 31 per cent, of real 
acul It rarely ur never contains any iron ; but a tutver free 
from muriatic add. 

Most cooibuBtible subeiancM decoinpQ«c thb acid ; but It doM 
net act Vpoa dmcoal and sulphur unless the tem{>erBture be 
eJevatiML If a piece of charcoal be ignited and thrown into 
cMcentimt*^ nitric acid It ocmbnucs to hurii u-itli great violence, 
giving out red vapotin. \Viii.'i) boiled upon sulphur it gradu- 
ally coorerts it into sulphuric acid. Phosphorits when throHm 
into concentrated nitric acid catches fire and bums with much 
•plendour. On iron concentrated nitric acid does not act 
nMaatly, but if we elevate die temperature tbe action be^iiut 
waMmiy an*! ixicoraes extrcraely violent ; much heat iH-ing 
erotvMl, and even light it \» wild ; though this has nev«r hap- 
pened in my triaU. It lu-tn nlw witli great violence on xinc, 
tin, copper, and manganese. Mercury, silver, caduiium, tiis- 
mutb, leail, cobalt, and nidcel, are di.«solved by it rapidly, and 
with effervesoenoe. Upon goUt, platinum, paUadium, rhwlium, 
iridium, and oemium, it eitlier doi^H not act at all or only vf-ry 
hebly. CoDcrntrated nitric acid setx firv to various volatile 
oik. Tbe combustion of oilft by this add unis first taken notice 
of by Borricfaius and Slare ;* but it is probable tliat Hombei^ 
coairauDicaie<l it to Sbre. In order to set fire to tl»^ fixe<l oil*, 
it miuH be mixed with some nulphuric adfl ; the risuuu of which 
•cvnM to be, llint tiiese oib contain watfr, which must be previ- 

• PUL Ttmw. Abr. ik 663, sod Ui. 663. 



ClMlk I. 


oust)' removed. Tlie milpliiinc acid cnmbines «-itli this water, 
am) allows tlK* iiiinc uciil, or nitln'r the oil aiid nitric avid 
together, to act. The drying oil* do not reqtiire any stil^dniric 
acid ; tliey have bocii boiled, aiid consequently dejirived of uU 

DihiCe nitric acid has the property of giving a yellow colour 
to vegetable hikI siiimal substnnces. In this veny it dyes the 
cuticle, iUid the yellow colour becomes orange when washed 
witli soap, and remains indelible till the stained portion of the 
cuticlo be removed. It in employed tu give a yellow border to 
the blue or green woollen cloth used in this country for covering 
tables. Many vegetable and animal substances when digested 
ii) it are converted into oxidic acid, malic acid, carbonic aei<l, 
Euberic aciil, wax, or fatty matter like tidlow, and nomeltmes 
also into liydrocyunic acid. 

It luLt llie property of neutralizing base*, and forming a daM 
of salts cjiiU'tl nitrates. 

The tint step to the knowledge of the constituents of this 
acid was made by Lavoisier, who proved by direct experiment, 
tlrnt it might be resolved into deutoslde of azote and oxygen 
goa ; and that these two gases when placed in contact, imme- 
diately reunited and fonned nitric acid. He concluded in con- 
8e(|ueiice that nitric aciil U a compound of deutoxide of azote 
ttlld oxygen ; mid he even tried to determine the proportion of 
tJie two constituents, but the result obtained does not constitute 
a very near approximation to the truth.* Mr. Cuvenilisli 
sliowed that when axotio and oxygen gases arc mixed, and elec- 
tric sparks parsed through tlic mixture in a glass tube standing 
over potasli ley, the two gases unite together and form nitric 
ad<l, which gradually saturates the potasli, and converts it into 
nitre. Hence it followed tliat the true confttituentsof thb<iu:td 
are azote and oxygen. From tlie proportions of the two gases 
which disappeared in this experiment, it ap|)eared tliut nitric 
acid was a compound of 

1 volume azotic gas, 

2 volimieji oxygen gas. 

and with this the analytical experimeiitit of Berlhollet agreed.f 
Hut it has been fully e»^ud>i»bed by numerous experiments, 
anHing othen by several of my owi],t ^^^ ^^ Ot>^ cuiiKtituenta 
of tluH acid are 


• Mdii. I'w. 1776, p. e73. 
t Fint FriiiciplcB, i. 100. 

I Mem. D'Arcueil, m. 



1 volume azotic gsa, 
S) volumefl oxygen gas. 

1 atom luote 

b atomfl oxygen . . 

' that its atomic wci|clit is (i-75. 





2. Htfpo»itrtms Acid. 

In tbe short account of hypomtroai acid which 1 liavc 
gircn tu the first volume of thU work (p. 127), I liave stated 
that it d(H« not Hcem capable of exi-itiug e'xcc))t in combination 
with 8 lnM>. However, M. Dulnug has shown tiiat llita opinion 
is not well founded. He mixed toj^lher 4 volumes of dent- 
oxide of azote, aitd 1 volume of oxygen jpw, and tJic 
mixture to iJie cold produced by a frecxing mixture, it con- 
den>ed into a deep j^reeii liquid, exceedingly \-olatile, and losing 
the liquid state when the cold was withdrawn. Now as deut- 
oxiile of azote is a compound of equal volumes of azote and 
uxygeu n'iihout any conilensatioii whatever, it i» evident that 
thin green liquid was a compound of 

2 valami>!t azotic gax, 

3 volumes oxygen gati, 

or {which is the same thing) of 1 volume azotic aiid 1 j volnme 
ozygeo gaa. This is equivalent to 

1 atom azote . . 1*75 

3 atoms oxygen . > 3 



which U ilie composition of h^'ponitrous acid. Thus it appears 
from Duluiig's experiment, tluil hyponitrous acid is cspahlf of 
ntistiBg uneomhined with a base. 

Tills acid when in contact with air mi xch with it and becomes 
a red vapour, which Ls not again cotiden»iblc without tin- appli- 
eatioD of an intense coUl. \Vhen thb arid w mixed with water 
it unilergoeH a partial decom position. Deutoxide of BXotc is 
given out with a strong cflertescence, and there remains a solu- 
tion of nitric aiul liy^ionitrous acid in the water. The same 
drcompUMlion taki>» place when we attempt to combine tlii^ 
Mtd with a base. But it is easy to obtain hyponitrites by 
double decomposition. Tlie manner of ])roiX'<:ding in to boil a 
mixlnre of nitrate of lead and mctnllic Irail in water ; a ilihy- 
(wnilritc of lead is formed. If this liyponitrile be mixed with 


the requisite proportion of bisuIpluitOf the oxide of Iviul and tlic 
!iu]phuric acid ^rill unite and form an insoluble powder, while 
the hypunitrnuB acid will unite witli the base to which the buI- 
phuiic acid was united, and form a hj'ponitrite which will dis- 
solve iu the water. We may also convert nitre into a hy])o- 
nitrite by raising it to an iucipiciil n^d heat, and keeping it for 
some time in tbiit stnic!. And M'va-ial other nitrates may be 
converted into hypo nit rites by » similitr process. 

This acid hu» the curious property of oombiniu); with several 
other acids, especially with sulphuric acid. If we pass a mix- 
ture of four volumes deutoxide of luotvuid I volume of oxygen 
gas tJirougU concentrated :«iilphuric acid, we obUiin a crystalliuti 
niiuw compuNi-d of sulphuric add, hyponilroux acid, and wutcr. 
When gently lieuted il melts, but becomcsu^in solid on cool- 
ing. Its specific gravity is 1 -831. When heated a little higher 
tlutn 270<^ it undergoes decompoitition, deutoxi<le of azote U dis- 
cu^^ed, leaving u mixture of sulphiirie and nitric acids. Tbc 
nitric ucid cannot bo expelled by distillation, prolmbly firom 
want of water, without which that acid cannot exist in a sepa- 
rate state. When tlic crystalline mass is thrown into water 
deutoxide of azote is disengaged. When sulphurous acid, deut- 
oxide of azote, oud oxygen gas are mixed, the crystals do not 
appear unless water be at tlic same time pT&<(eut. 

According to tb« analysis of Henry,* this crystalline nuisa is 
composed of 

4 atoms sulphuric acid . > 

4 atoms water 

1 atom hyponitrous acid . . 4*75 





If we suppose the hyponitrous acid to unite with luilf of the 
■ulpluiric acid, tlie remainder will consist of 1 atom sulphuric 
ucid united to two atoms waU>r, which is tlie cumbinulioti uf 
tlwt acid aiul water of mott eaity congelation. Is it to this that 
we are to ascribe the state of crystallization which the double 
acid assumes ? 

3. A7frOM Jcid. 

In the first volume of this work (p. 128), I have given an 

account of the method of procuring nitrous acid from nitrate of 

IciiA, an<l likewW its propertied) iiiifl composition as detcnniiied 

by Duloog. Wiiut is culU-rl fuming nitric acid, contains a oon- 

* Antuds of Pltilo*0|>h]' (Sd aerim), xi- SOS- 


■ulvrobti* quantity of nttrouti acid. If vtc AMi miclt aii acid 
[by the he«il uf Ui« uiit«r-b»tli into nrpcrircr, kept cool by being 
I HDroiindcd vritli a mixture of •inow and salt, and taking van: to 
I ftop the distillation before lie acid in tlie retort becomes colour- 
lesB, wliat passes over is iulrott<t acid of n dc«[>-rod colour, iktid 
t^ air til tbe reoeirer is mixctl witli mA a qiumtity of detwe 
red fumes that it appeora r|iiitv ojKujitr. Nitric nvti! diwolrra 
it in considi'n»I)le (jiiniility, but only in fixi-d pro|>ortiim?i. If 
more than the rt^juisilc profwrtion be added, Mitcbcrltch has 
olMerved, that it sepamlM Irom tbo actd, and mt-ims on the siir- 
ttof as oil doos on wat^r. ^Mien this acid is mixed vilh water, 
deotoxide of azote ts gii'en out and nitiic acid formed in it, and 
titil got» on attgrnetiting till at last it becwnes altogether a 
tombbuUlon of nitiic acid and water. At least it becomes 
imlwiiltiW by absorbittg moixturo from tbe atmosphere. Tbii* 
evolution of deitloxide of axote ia accompanied by n change of 
mhfiir in the li(|ui<l. It passes from red to yellow, then to 

I gmn, then to bine, and at last it becomes colourless. 

^B I'vo tiifferent opinions Itavi' lieen advanced respecting the 

^H nttttre of nitrwu add. Tbe greater iiuml>er of chemUts con- 

^Bridtr It a* a peculiar add, composod of 

^^^^L ati>m azote 

^^^^1 4 atonDt oxygen 

^^^ 5-75 

Bat it ta destitute of the property of combining with bases ; no 
■och claaa of nits as nitritea existing. On this account Berae- 
lina cofisideTs it as a compound of 

»1 atom nitric acid . . S-75 

I atom hyponitrous acid . . 4-75 




.nd ban given it tin? niune of aciiium nilrotonitrKum. It la 
obriotM that tbia view of its composition ivill come to the nne 
thing, as for as the ultimate elements are concerned. For 
nitric acid l»eing a compound of I atom azote and 5 atoma 
oxygen, and hypotiilrous acid of 1 atom azote aiid 8 atoms 
oxyg«Bf it is clear that if we combine them togetlier we have 
a ootnpotuid containiiig 

2 atoms azat« . . 3-5 

6 alorM oxygen . . 8 






Now this is just die same a» 
1 ntom uzutc 
4 Dtvinit oxygen 




wtiicli is die composition deduced from the analysis of Duloiig. 
As nitrous acid dors not combine with liases, it is a matter of 
indifftTcnec which of diesc views we adopt. 


Tiicre are two acids at present known, composed of carbon 
aiid oxygen, namely, carbimic acid and oxatic acid, 

1. Carhonic Acid. 

Cnrbonic acid exists ready formed in prodif^ious quantity 
in the mineral kingdom, cciii>ti(uling an «8seniial constituent of 
Ciirbiiimte of lime, which, under the nanea of niurl)h>, limestone, 
and chalk, occurs so abtin<Iantly in almost c%-ery part of the 
earth. It exists also in frri-iit ahundiinee in rHrbonate of iron ; 
white carbonate of baryli-s, stroiitiikn, miigiie!«iA, lead, -copper, 
bismiilli, and zinc, oectir also in grcfiter or smaller qiunitity in 
the mineral kingdom. Jt is given out also in great abundimce 
by active volcanoes, and many spruigs iji different parts of the 
earth are impre^iated with it. It is formed also abundantly 
by the burning of wood and pit coal, and by the breathing of 

The exixtenco of tliis nulwtance as an essential contttiluent 
of liint'stone, was first denionstnLtcd by Dr. Ulaek, who gave K* 
cnrbonic acid the name of fixed air, because it exists in a fixed 
state in these mineral bodies. Its properties were first inves- 
tigate<l by Mr. Cavendisli. Mr. Keir, from u knowledge of 
Uiege, first concluded tliat it was au acid, and gave it the name 
of mlcfirrmu arid. Bergman adopted the same opinion in 
1774, and gave it the name of atrial acid.*-. Mr. Bewdly 
called it mtpAitic acid, because it cannot be respired without 
occasioning death. Finally, Lavoisier, after proving it to bo a 
compound of carbon and oxygen, gave it the name of carbonie 
add, which has been long in universal use. 

I have already given an account of the properties of this 
acid in the first volume of this work (p. 161). I1ie salts 
which it forms wilh bases have received tlie name of carbonates. 
It is by no means a powerful acid, being expelled by the greater 

* Opute. i 1, 


namber of the oxygen aclia. As is tbe case with weak ucids ^S 

it bn the pro[Mr1y of uniting tfilli th« different bases !□ two, 

and fr«^uently in tlinn^ i>r(>portioti». 

This acid hns bt-rn shown to b« a compound of 

1 atom carbon , . 0*75 

2 atoms ox}-gcn . . 2-00 

and its atomic weight t» 2-75. 

2. Oxalic Acid. 

A« the earliest and U'»t account of tlic oxalic acid ww pub- oiiemwr. 
Ualied by Bcrfrman, he was for a long tjmr: reckoned tlie dis- 
coverer of it; but Mr. Ehrhart, one of .Sclit't'lc's intimate 
Mrn<Is, tnfonns us. (hat tlie world is iiulebtt-d for its knowl<>dge 
of this acid to tliat illustrious chemist,* and IIcrmbsUwH and 
Westmmb assign the di««orcry to tbe same autbor.f Tbe 
aasertions of these gentlemen, who had tlie best opportunity of 
oblatnitig accurate infnrmiitioii, mv certainly siitlieiciit to estaU- 
Urii the fiiCt, that Schccle was tlie rrid ditteovi-ntrr of oxalic aci<l. 

This add vxitits, ready fonned, iti tliv rcgetablc kingdom, 
sonictinirM in the state of bino.talatc of potash, as in otm/m 
acttoaeiia and common sorrel ; and sometimes in the slate of 
oxabte of lime, as in the root of rhubarb and of many other 
|ilanta. I have given a short account in the first volume of tbl<) 
work (p. 172). of the metiiod^t of prepiiriii^ tills add. It may 
be procured altui from tlie hinoxalale of |)ut:t.'>li, by diiwolring 
tbe salt in bot water, and adding cuiboiuitc of potash lu long its 
anjr effervescence takes place. Then add a solution of acetate 
of lead, as long as a white precipitate continues to fall. Col- 
lect the precipitate, wash it and drj' iu For every 18) parts 
of this powder add 6-125 parts of strong sulphuric add. pre- . 
vioualy diluted with ten timw ib< weiglil of water, and digest 
the mixture for some lime. The itulphuric acid will unite witii 
the oxide of lead and form an iiiMrluble powder, while tlie 
oxalie acid being disengaged will remain in solution. Separate 
the salphule of lead, and concentrate the solution till the oxaltc 
acid crystallizes. 

Oxalic add thus obtained is in transparent or translucent i>nv(RM. 
crystals, which hare usually the form of flat tables, consisting 
in reality of six-sided uregular pri«m«. Mr. Brooke has shown 

• EUcft'o Mi^uiae for Apothecaries, ITfU, port L p.54u 
f K«ir'« DicliMMTf . 




that tht: primary form is aii oblique four-«t(l«cl prism. The figure 
in the margin repr<'setit« the most common figure of tlie crystals, 
ill M-hicli P, M, M' represent the primary liiwft. The foUowinp 
are the measurements of the angJw made by Mr. Bro<Ac.' 

I' on M or M' . 

980 30 

M on M' 

63 5 

P on a. 

. 129 20 

V on c 

. 103 13 

The taste of (Jieite crystals ts intensely sour, and when tnkcn 
internally, even tn very Hmall qiuinlity, they act m it poison. 
VVTicn takrn totheumount of about half an ounce thi-y actK-itb 
great rapidity, and dt-slroy life in a very short time : when giveu 
to the amount of half a drachm, they prove equally fatal; but not 
till after an interval of some diiys, lu haft '■eeusliewn by the expe- 
riments of Dr. ChriHtisoQ of Edinburgh. These crystals arc solu- 
ble in about their ou-n weight of boiling water : water at the 
temperature of flri'?" dissolves half its weight of them. The 
specific gravity of lho»olution is l*0593.t One hundred parLHof 
boiling alcohol dissolve 56 parts of these crystals ; hut at a mean 
temperature only 40 purts4 Liquid oxalic add has a very 
acrid taste when it is concentrated, but a very agreeable acid 
taste when sufficiently diluted witli water, j 

These cr^'staht are composed of real oxalic acid and water. 
When heat is a]tplied a portion of the arid is driven off, but 
not the whole. In several crystals of oxalic acid wliich I 
examine<l, exactly luilf the weight was water. Now a« the 
atomic weight of tliis odd is 4-5, it is obvious that tliesc crystals 
were composed of 

1 atom add . . 4-5 

4 atoms water . . 4-5 


But from tlic experimeiils of Bentelitts, Dr. Proat, aixl several 
other persons who have turned tlieir attention to the subject, 
it would appear that in gencrul they arc composeil of 
I atom acid . . 4*5 

9 atoms water . . 3-d76 

* Annnli of PhUoMphjr (id Mricft), n. 1 1 0. 

t ibia. 



or ihmt they cuDtain one alom less \i-ater llwui the rrjstala wliicli "»" '. 
I exam'iiiett. When we Iieat these crj'stals we can drive off ' 
two atoiDR itf tlie water. Hul ibe tliinlatom reraainit, aixl isin- 
nat be got rid of tmlenit we combine (lie a«id to a. base. F.vvii 
wlien we iinile it lo liute, the oxalate of lime fonaed &tUl retains 
the atom uf wuler. 

Oxalic acid i* n miick morfr powerful add lUun carbunic ; jet 
it Im a ten'lency like it to combine n-itb bttiips in two or three 
propartioiiB. Tbc «sUs which it forms arc chilled ora/atet. 
TLoagh tl u composed, like euHionic ucid, of carbon and oxygen, couuniuai, 
yirt the state of the constituents In it must be dilTeient from tlieir 
Mate in curl>nnic acid. When a carbonate is heated, ibo civ- 
booic arid eiilier remains lixed to the base, or it is driven off 
unUtMvd. Hut when an oxalate i:* healed, the acid nndergoe* 
dccoin{MJHiiH>n. CVirb<itnc acid and carltonic oxide are usually 
driven iiff. und fri.ijHenily aquiuitity of ctiiircoal tMcvolvctl, No 
oil Lt vvvT given out, as linppciw wlifu itci<U with ii compound 
la»e are lUstilled. In short, oxalic ucid hears u strikin]^ aiiahigy 
io nridi wilh u compound base, tliough it contains only carbon 
and iixyg;en. Dulunj; has ondciivoure<l to account for tlii^ 
anoamly by coiuitlcrinj; the abnu of water that cannot be driven 
off by heat, as an euenliiil eonvtilucnt of tlie acid. According 
to ihii view of its con«tiiu(ion it woukl b<- a coni))ound of 

4 atoms oxygen . . 4 

3 atoms carbon . . 1*5 

I utom hydrogen . . 0-125 


Bui die objection to tliia view of tlie acid in, tlial it may be 
uiitd'i! to M)me liiiAi>:s ox oxide of lead and oxide of Kiiic, with* 
out the atom uf water, which »eem« ctisential to its existence in 
■o isolated state. Then its atomic weight is 4-5, and it con- 
■ina of 

3 atoou oxygen . . 3 

& atoms cwboti . . 1-5 


The &ct that it is a more powerful acid tlian carhnnic, lliough 
it contjuns les« oxygen, in inexplicjible, unless we view it a.^ an 
acid wilh a ci>nipound ba-<e. For in them the strength of the 
acid is umloubtedly dependant upon something else tlinn the 
prepondemncy of tlie electro- negative constituent, which un- 
<loubiedIy produces the effect in acids with a simple base. 
II. c 



siHri.e DxyaEN acids. 

<AiIk L 




Tic acids fcmned by the combitiation of tliosi* two bases witli 
oxygon, are two in number. I'lioy nrc botli feeble iicitU, aiid 
capiible of combining u-illi bases in vnriou!) proportions. 

1. lioracit Aciii, 

Tbifl acid united to tttAsi (K-ciir^ in China and Thibet. It 
OM'un in a free nliile, and Kocinin^ly in great abundance in 
itereral lakes in Tuscany, Great quantities of thin native acid 
have for some time been imported into this eoMiitryi where it 
is com-erted into borax for tlic use of the potters, who liave 
been long in the hnhit of using it as a glaze for the finer Itinds 
of »noni'-wan'. The most (•onsider.ible of the Tuscan lakes 
which yield this iicid is the Cerehiiiju, on the Monte rolondo, 
ThoHjih it is only about (fO feet long and 42 ft-et bntnd, the mil 
in the neigliboiirhood becomes covered with an fffloreseeiice 
consisting chiefly of bonicic add, but mixed with sal ammoniac, 
and some other saline matters. 

Itnmi-tc acid is usi»Ily prv|mred from homx. l-'ouT parta of 
this salt are diiuolred in boiling water, and one part of concen- 
trated Milplmric acid is added lo ihe scdtiltun. The horuclc 
acid is deptiMted in crystalline ScnU-s iw the litpiid cools. These 
scaler arc to be collected, dried, and then expooed to a red heat 
ill a platinum criicihle to drive olT a portion of siil|>huric acid, 
wliicli ciinnol be separated by washing. It may Uivn be dis- 
solved in boiling water and crystallized anew. 

Boracic acid, thus procured, is in the form of thin hexagonal 
scales, of a silver)' whiteness, hu^Hng some reeemblanee to spcr^ 
maectl, and the some kind of greasy feel. It fats a bittcrislt 
cooling taste, and nt last leaves an agreeable sweetness. It 
has no smelli but when sulphuric acid is poured on it, a tran- 
sient odour of nniKk is prixlucviL* 

It reildt-ns vegclid>li> blues feebly. And Mr. Faraday Ihm 
likewise renuu-kwi that it n-ddcns tunneric paper. Its t^edHc 
gnivity, wtiile in scales, is l-4^}!),t but after ignition it becomes 
as high as 1-830. J 

It is not altered hy ligliL It is fixed in the fire. At a red 
heat it raelta, and is converted into a hard transparent glasa; 
whicli K-vomcs Mnnewhat Of>uque wh<tii cxjKMted to the air, but 
does not attract moisture. 

* Bcuai^ de Sale Seilul. 1 11%. f Kinrwi'ir MinenJogy, ii. 4. 

} R^ct and Dumas AtinuU uf PlttlMOfihy (jti Mrirt), tii. '.sys. 


I have alrewly i>tato<l tKut Uie atomic ve^bt of bomt-ic acid "■■ >- 
ii 3, aiid lliat U is a compound of "'"^ 

1 aloiD borou . , I 

2 moms oxygen , . 2 

TTm' sorW obtame<l coiutittite a hydratcd arid composm) of 

1 main wid . , 3 

2 U0IB8 water . . 2-*23 


It is rerji'fiparinjfly soluble in u-ati'r. Hoitiitfrn-aKir scarcely 
d J Mt ih'ca 0-0*2 of boracic acid, and cold u-»t^*r » mill Miiutllcr 
(ptuitity. M'litu tltit »(iliitiun is diHtilli-d in cIum- vcsmcU, [lart 
of Um acid evnj)ofalt!S aJonf( nitb llie water. and crj'slallizcs in 
tbt r\'Ci-iver. Water, tliir<*fore, rvmlcrs it in some measure 
nbtilo, tlioujfb it IK pcrft-ctly Bxi-d ulicii in a §tate of dryness. 

It U soluble in iilcoliol ; and aJcubol contauiing it burns witli 
a gTven flaini\ Pagwr dipped itito a solution of boracic acid 
burn* witJi a green fiame. 

Willi tlio aasistaace of a distilling lieat, it di-isolvea in oiLt, 
specially in mineral oiU; itnd nitli i)ii'm> it yields Ruid und 
solid prutluetK, wliicli ^vo » gp^cn colour to s]>irit of wine. 

Doncic acid is an exceedingly fc1^lll<r ucid ; i-o mucli no that 
k fa eapiible of acting on very few of tlie metals, IndcM^d if 
we rxci'pt iron and zinc, there are none of tbese bodies wliicli 
it u cnpiiblc of <liasolving. It combini'^ witli Iwistrs in a great 
Turiifty of proportions ; but no ((uanlity nf il whatever in capa- 
ble of dt>pnt-ijig|>otasli or soda of ibc pr«|>erly of giving II grei'n 
oolour to regetabli! blue;*. 

Tba albt wkieb it forms have n'reivitl tbv name of bwaten. 
Tbttir proiwrtiM Lave not been mudi invc^tigiited. 

2. Siikic Acid. 

Siliea^ or siiitic atid, as it sliould be called, cxi»t« in greater 
abunduuce tlian any otber, asit entersosacon.'slttuonlintunnitit 
ui Uie rucks and stony bo<lies of which the earth is conipotied. 
Tlurrv are no fever than 167 species of mineraU that contain 
rilicB M one of llieir esseDlial con»lituenli>. Kock crystal, quartz, 
dialoctliMiy, uiid Hint it>mi>i of silica very nearly, hut not quite 
in a Ntatv of purity. But from them- budicx it i» (-i»y to obtain 
It quite pure by die following jirocess : Put into a plulinum rnr*'*"">- 
crodhle eiptal weights of aitbydrons carbonates of jiotash and 


t1»p. I. 


soda wliicli «iiter into rii>i»it ut ft comparatively low temper 
tun-, luid to tlie liijuul inmvf tM n (]uiinlity of (lint or qitartx, 
previou§ly reduwd to n fine powder. Oirhoiiio acid fpw will 
be given out, and tlie powder will dissolve in the alkaline li()ui<i. 
Continue (o add tlie powder a-t lon^ as ilie effervescence a>n- 
tiiiue*. TTien allow tlic wliole to cool, and dissolve it in dilute 
muriiitic acid, wliicli will dixKolvc* liotli the alkali and tlie i^ilica. 
Filter the HoUilion and con«;<:-iilnit'' it liy <'v;i|i<initii)n. It will 
assume the form of a tliick tran^jpan-nt jelly. Ctinliniii- thti 
bent till tlic jelly becomes a dry powder, and digest tliiif pow- 
der for a couple of hours in concentrated muriatic cicid. Tlieii 
add a sufficient quantity of liotu'ater, and throw the whole iijwn 
a filter. M'asb die silica perfectly, and tlien allow it to dry. 
Finnlly expose it to » red heat to ex[iel all the water wlitcb it 
may rctuin. 

Pi«i»>nM Silica, thus obtained, is a line white powder, without cither 

taste or smell. Its particles have a harsh feel, as if they con- 
dsied of very minute grains of sand. Its specific gravity is '2'tiQ.* 

It may be snhjected to a very violent heat Mithout undergoing 
Miy cliiiDge. Lavoisier and Morveau i>xposed it to the iiction 
of u fire inH intuit led by oxygen ga» without any nItrratioii.f 
Sauiwiire succeeded in fu^in^, by nicoiw of the Mo«'-pi])o, a 
portion of it 6o extremely minute as srarcoly 1o be perceptible 
witliout a ghiss. There is do difficulty in fusing it by means 
of the os)'Ken and hydrogen plow-pipe. 

M'hen silica is preci|>itated from fluowlicie aeiil gas by n'ater, 
it dissolves very readily, and in eonsi<]eral>li' quantity, in that 
liquitL Hut after igniiioii it lose4 iusoliibtiity cnrirely. When 
boiled in a solution of carhunate of potaHli, or rarbonate of wkUi, 
it dLiftoIvet in considenible qutintily, and ihc Kolntion, if con- 
centrated, platinizes on couliiig. But if we dilute it witli boil- 
ing water, the silica remains in solution afWr tlie liquid has 
become cohl. Yet no carbonic acid Is given off in lhi» caxe. 
'I'hU method of disMdviii); silica ui .on alkaline carboiiut4> was 
first otMcrved by VkiS. It i» in ibi.i w.iy that it is held in solu- 
tion by th« Geyser Kprinj^s in Icoland. 

^loet Bjirings of water contain a Nmall qiiniitily of hilica in 
solution. Tlie only acid which dissolves it uf^er ignition is the 
fluoric. Tltts property enables »s to apply fluuf spar with great 
advantage to the analysts of minerals. If we mix a mineral to 
be analyzed (previously reduced to due powder) with fliior n|mu- 
and sulphuric avid, and heat tltc mixture, tlie whole xilica will 

• KWiu'i Man. i. ID. f Jm», dg I'Erolc PolylMh. t. iii. 999. 


ocBpe in combinatina with tiie fluoric add; and the alkali, if n**L 

toy he pre»eai. may be obtained in tJie state of sulphate by ■ 

£^esiing tbf residua) matter iritb water. 

£SUea baft ibe property of rumbiiiiDj; in definite proporliADii )ir<ic*«. 
with water. Hut the compound ix luit very intimate. Vet 
that an affinity exists between silica uiiit water in obvious from 
the gelatiuous state whiclt it nMumes. Ge.hitiuous silica allowod 
to dry in the o|>cn air till it ccasra to wet pa\KT, tJiough still 
rvtluning ita sl:iU-, u a compound of 

I atom MiUcB . '2 

13 fttums water . U-62d 

When tlie jelly is allowed to dry in tlic opcti air it aASumea 
th« a|>}K-arance of gum anibic, or indeed of clialcvdony (oidy it 
wasta the hordueM of that miueral). lu that state it is a cotn- 
pomd of 

1 atom ftilica . , 2 

1 utuin water l-\'2o 


When silica i» fomfd with an alkaline carbonate, if we dLaiolvo 

the autu in a small (]uuutity of water, light white flocks of iulic« 

mnain. ^Vh<-n tlil-M.' flitck^ an- u-ailied and diii^d in a tempe- 

, Atw of about H5'°, they constitute a dihydmtc composed uf 

2 atoms nilica . . 4 

I atom water )-l2A 


51 25" 
Tbougli ulUca does not redden vegetable bhies, yet it enters 
into itofiiittv i.-tMuptmniU wiib thi- dilTorent liiL'^e*, and forms 
line coni|K>Hnds which arc distiii^ii«hed by the n<iinc of n'/i- 
'es. Like other weak acids ■' is ntpiible of ciitcHiig into a 
It rarii'ty of combinations with bases. The contpoiiuds 
it forms are fre<|nently so iiitiinnte, tliat no otlier acid is 
■pcble uf removing the base ami setting the Kilica at liberty. 
be ditrrmit kinds of gUtvt cou>i«t of two or more nilicatc* 
cllr)! tofretber. SillcatM of p»tiL<b and of Kod;i an- soluble In 
r, but W'lien u little of lUi cjirlby silicutc is added the glass 
become* insoluble. 

I hare kIiowu in Iho (int volinnv of tltU uork (p. 225), tlint 
liie atomic weight of «ibi,-a u 2, and that it is a compouml of 
• Rrei Principles >■ '("• 





1 atom silicon 
1 atom oxygen 


Phosphoms combines in various proportions with oxygen, 
and foirms at least four acids, of which I shall treat in the pre- 
sent section. 



1. Phosphoric Acid. 

This acid exists chiefly in the animal kingdom, where united 
to lime it constitutes about ^ths of the earth of bones. It occurs 
also in the mineral kingdom, constituting 13 mineral species in 
which this acid occurs united to different bases, as lime, mag- 
nesia, alumina, oxides of iron, copper, uranium, &c. 

It is usually procured from earth of bones, and I have given 
one of the easiest processes in the first volume of this work 
{p. 237). We may obtain the acid likewise by burning phos- 
phorus in a porcelain cup, and covering it with a glass jar capa- 
ble of holding about 300 cubic inches. . The phosphorus bums 
with splendour, and a white smoke rises which condenses upon 
the inside of the glass like flakes of snow. This combustion 
may be repeated { taking care to renew the air of the jar every 
time), till we obtain enough of phosphoric acid for the object 
in view. 

Another method (first put in practice by Lavoisier), is to dis- 
solve phosphorus by boiling it gently in a retort with twelve 
times its weight of strong nitric acid, previously diluted with 
twice its weight of water. The solution goes on with effer- 
vescence, deutoxide of azote being evolved. A receiver should 
be attached to the retort, and after the phosphorus is dissolved 
the nitric acid should be gently distilled off, till the and in the 
retort acquires the thickness of a syrup. It is now to be put into 
a platinum crucible and gradually raised to a red heat. It gives 
out water, and melts into an oily looking liquid, and by continu- 
ing the heat it becomes at last a transparent, colourless liquid like 
water, which, on cooling, assumes the appearance of perfectly 
limpid glass. In this state I found it a compound of 
I atom phosphoric acid . . 4-5 
I atom water . , . . 1*125 




Itraa llierefore a liyctrate uf phtMiplioric a^Jd. By (.■ontiniung 
iIm heat moiv of tlw wali'rmiiy 1k' driven off. Diiluiigobrnined 
it conpuNiNl uf ulino«t rxacdy one atom uf uctd und one alom of 
wUcr tut I did, but M. H. nose, by continuing the heat totiger, 
reduced tlie water so mucli, tUat wltat renmiited was a eon> 
pOBlld of 

Pliospkoric acdd . . 4-5 
Water . . . 0-469 

Now 0-469 uf water is not initeli more tliiui ^ of an atom. 
Rose, therefore, liad obtained uciirl)- a trialiydraie, or cs>in> 
pound of 

3 atonui aciil . . 18*6 

I atom water . . l-t'23 



Bat however long continued tlio heat may be, we ouinot drive 
off the whole of the wuter. 

Though ifae volatility of this acid be iticonsidemble, jet at a 
red heal it rices in a M'liitc emoke, and inij^bt probably be <li»- 
vpated, were the lical long enougli contiuuotL With the vapour 
of water it volatilizes very perceptibly. 

Tlte specific gravity of tliia add, in a state of dryness, is 
3-887;" in the state of gift*.-*, 2-e3l6;t in tlie itate of delique- 
scence, l-41".t 

'Ilii'i acid is very soluble in water. When in the state of 
white flakes, it diiwolvcs with a lil)»ing noi«e, eiinilar to that 
Bade by rcd-but inni pKingcl into v.-nler. When in the state 
of glUM it lJt^Nl>lvl•K iniicb more slowly. The beat evolved dur- 
iitg tlic combinution of this uctd und water is much inferior to 
that evolved when sulphuric add enters into a similar combi- 
nation. Phosphoric acid obtained by deliquescence, when mixed 
with an i-<{uii] (juantity of diiitilied water, aecjuired so little heat 
at to raice the Ihernicitneter only one degree, a» Mr. Koge 
ohMrred. M. [^voislvr ndsed the ilH'nnumeu^r from hd" to 
93° by mining phosphoric acid, l>oiled to the i-oiiisiKli-nce uf a 
ayrup, with an e<iiial quantity of water; and from 50* to 104° 
when the aci<t was as thick aa turpentine.} \\'hen the flocks 
of tbb add have Wen ignited, ttiey resist Holulion in water for 

fioasiderablo time-, and dual about in it not unlike docks of 

* Bm^iMt'a Soosmphia. p. SO. Eng. Trans. 
t numifiali. Ann. 4c Chim. xxtiii. 1 1. 

t Bbcjc. UetlMd. Cliiai. i. 821. 

S Keir'i KdionoT)'. 



co« !• silica. Yet they at last disappear, and constitute a limpid sola* 
~- tion, provided the phosphoric acid be quite disengaged from a 


Though this acid acts with but little energy upon animal and 
vegetable substances, it combines readily with bases, and forms 
a class of salts called phosphates. Its tendency to unite with 
these bases is very energetic, and when assisted by heat it is 
capable of driving off all acids which possess volatility, even 
sulphuric, nitric, and muriatic, which have a stronger affinity 
than it for bases by the moist way. It has the property oS 
uniting with most bases in a variety of proportions, and the 
alkaline phosphates crystallize most readily when they contain 
two atoms of acid united to one atom of base. 

When dropt into a solution of nitrate of silver, a yellow pre- 
cipitate talb, which is a subsalt This tendency which it has 
to form subsalts, makes it very difficult to analyze the phosphates 
by precipitation. We can dissolve iron and zinc in dilute phos- 
phoric acid, but scarcely any of the other metak. The phos- 
phates are best obtained by double decomposition. A great 
number of them are insoluble in water ; but they all dissolve in 
nitric and muriatic acids. 

I have shown in the first volume of this work (p. 238), that 
phosphoric acid is a compound of 

1 atom phosphorus . . 2 
2^ atoms oxygen . . 2'5 


2. Pyrophosphoric Acid. 
Otamrj. In the year 1827, Mr. Thomas Clark of Glasgow, observed, 
that when the common phosphate of soda of the shops was 
exposed to a red heat, its nature was altered. When the ignited 
salt was dissolved in water and crystallized, the shape of the 
crystals was quite different from that of common phosphate ; it 
contained only half as much water of crystallization, and it 
was not the least altered by exposure to the air, whereas com- 
mon phosphate of soda speedily effloresces. When a solution 
of this new salt was dropt into nitrate of silver, a white preci- 
pitate fell consisting of neutral phosphate of silver, whereas 
common phosphate of soda throws down a yellow-coloured sub- 
Bait. Mr. Clark gave to his new salt the name of pyrophos- 
phate of soda, and to the acid which it contabs, and which 

pYnorHOBrttORic acid. 


obrbtiuly possesses lUffereot properties from llioee of common 
pbokphftric 4eii), tlit* iiiirotf wX pi/rophotpAorie acid.' 

M. Stfomcyrr uf Ooitiiiiris) informs tis ili:it one of his pupib 
bad wme yMn ago nnulf u similar obNervation with Mr. CUui:. 
that iifniu^ plioepliate ufmKU prccijiiuiieil wlvi-r ulitte. And 
SUitmeyer himself luid usecrbtiued tititi plinoplioric iieid pre- 
pueiJ b\* means of nitric acj<l from ptKvspltartiit, nnpiirvd tlio 
•UBT pro)>erties by i£ni(ion, nnd tluil pliwpliorie nc-id jin-piintl 
by bumin|^ ptraspliorus possesses it also. Slromeyer resumed 
lin !nv(.>>i!^tion of the subject after the publication of Afr. 
Clarii'* paper, aiul aAcerLained iluii l)ie cliiiraeli-n anil 4-(in))>o6i- 
tioa of llir pha^>liBle and ])yn>phii>pli;i(e of silvrr !irr quite dif- 
fprenL lie found tbat wbrn pyrnpliosplmte of silver and pho<^ 
plale of soda arc boiled toi^tlier r double decompositiuti takes 
place, uiid there are formed phosphate of silver and pyroi>ho«- 
phalo of mkU. All the other pyrophosplmtes trie<l were etjually 
drcmnpoMH) by phosphate of soda. He found id.Mt that when 
nitruir of nilver was dropt into a mixture of phavphuf^ and 
pyrapbotqihalt- "f r>iida, phonphate of MJvei- pn-ripitates first and 
aft«rrwtud« pyro]i|ii»{>liate of silver. It is obvious from this 
that pyropbo»{)hoTic aci<l is a weaker acid tlinn plios|ihoric. 
The pyro]>hiNiphate)i uf lead, mpper, nickel, cobnit. uranium, 
bikinulh. innu^iiese, mercury, gluciiia, and ytlriji, are nr<li«- 
•olvnl with great fueility by an excess of pyr»phos|>hute of 
NHbi. White the precipitates produced by phosplute of soda 
are not retitwolve*! by an exe»s of (bat Halt, tJiis shows very 
clearly thnt the pyropliD«pluit«>H have a much greater leu<leiiey 
to form duubli' Mdln tlinii the phoii]>liat<^'s.f 

h a clejLT fnKU all this ihnt pyrophuephoric and ])hoKpboric 
acids poasess quite dislincl chiimcters. But Stromeyer hns 
»kmra tliat the proportion of tlte elements of bolli is exactly 
tlw mmtf each being a compounil of 

] atom phiri|)horuM ■ . Q 
2^ atoms uxygeu . . 2-5 


t WW UMiiiced at the request of Mr. Clark to examine the con- 
Mhmion of bis pyrophosplinrie acid ul t)ie time of Jm dis<.-ov«ry, 
and 1 wa« surprised to find ilutt its atomic weif^ ht vnt-t precisely 
dw mmt M that of cominon phosphoric HciA. To what then 
lo owribe Un^ difference between these In-o iicids ? The 

• BeewMo't Gdia.JenrHl.vit. i06. 
t AiHi.deCtuM.ctilePbys.sHiL3»4. 



c^>l^ I. atoms of wliJch lliey aro composed amount to 3J ; or if we 
think it necessary to get rid of tlie hulf tilom, by doiiblin|<^ the 
number of atoms then the atoms M-ill nmount to 7. of which 2 
are phosphorus and 5 oxygen. Now it is perfeetly coneeirahle 
that 7 atoms may arrange themselves two different ways, and 
Uiat when in one arrangement they may form phosphoric acid, 
and when in another pyrophosphoric acid. We shall find as 
we proceed thitt these two acids arc not the only ones whose 
atomic con.siitiition i.s the same. Tlu-rc arc »cvcnU olhem in 
exactly tlie same circumstances, and doubtless new ones will 
come under our review, as the science of chemistry continuca 
to advance. 

It is evident from tJie analj"ses of Stromcyer, that the pyro- 
phuMphute of silver is a compound of 

1 atom acid . . . 4*5 

I .itiim uxide of silver . . 14*75 

wliUc the yellow phosphate Is a compound of 

1 atom ueiil . . . 4'5 

I J atom oxide of silver . . 22' I S3 
AH thft salts of the pyrophosphoric acid seem to be neutmt, 
while many of tlie phusphnles liave an exccsa of base or of ncid. 

3. PhoaphoroH* Acid. 
The mode of forming th)» aeid i)y ntean«« of sesquichtoride of 
pliMphonis first employed hy Sir II. Davy, has been given in 
the first volume of this work (p. 23!)). It may bi^ obt(iine<l in 
all aiiliydrous slate, or nearly so by burning pho>t:]ihonft in a 
glass tube, drawn out at one extremity into a capillary orifice. 
The phosphorus when heali-d Kufliciently burns with a greenish 
flume, uiiil gives out Init little light, and thu phosphorous acid 
formed is condensed in the inside of the tube in tlie Kliite of a 
white powder. In this state i( is volatile, and may be drtven 
by the lieat of a lamp from one part of the tube to unotber. 
When brought into the open air it catches lire and btirii« witli 
spk'iuloiiT, being converted into phosphoric aci<i ; but if wc 
alkiw it to remiuii in the tube it gradually absorbs moisturCi 
Hiid is converted inti) a liipiid. 
ivtrujiisn. According to Drocjuet the easiest method of obtaining this 
arid is to put a qiuuitity of phosphorus into tlie boitom of a 
glass cylinder, with a narrow orifie* filled with hot water, and 
by means of a glass tube t4> mii^ u current of chlorine gas paM 
llirough the liquid phosphorus. It is uistuiilly abiturbed. The 
proeew is to be continued till tlie clilotine gtts begins (o disen- 




riiospuoHous Acin. 



gaffe itself frata 0>e plioephorus, when we must stop, otbera-isc 
|(lui»{)boric acid wuuld he form«l. Ses(|ui chloride of pltospliorus _ 
ift formed and decomposed by thi- watvr itiUi inurialic ucid and 
pb o ^»hocoi» aod. VVheti tlto whoiv has become cool tl>u liquid 
poitian b decunliil off, «iul die muriatic acid i§ scparattsi by 
distilling it in a retort till it becoroe» of a syrupy consistence. 
If we now put it under tlic exhausled receirer of an air-pump, 
togetber with pieoeo of Holiil poUuli to absorb tin- H':itor, and 
any nuriido uid thiil may Ik- evolved, the pbosplioroua acid 
gntdually shoots into tranflpmcnt pritimatio cr)-Ntal9. 

Davy aKeflaincd that tcu parts of il when heated in close c 
nm-b IvfV &■& parts of pbosphuric acid, und gave oiT 1'5 partu 
of sTAquihydrct of pIiiiApbaru.s.* Tkb would make the crj'stals 
to be composed of nearly 

■1 atoms phosphorous aci<I, 
1^ atom of water. 

But the experiment couhl not be correct, brcaa«e the phos- 
phorle acid would rciiiia u certain (jiunitity of wat«T. 

PhiMpliorous Rci4l luui an iivt^l tiKslc, und rcddci» vegetable 
blue*. It w obviontdy » verj' feeble acid. VHicn exposed to 
the air it absorbs oxygen, and is contorted into phoipboric 
add: but tlits change goes on very slowly if tlie ac!<l be con- 
epRtmted. It k much more rapiti when the acid v* <lilntcd with 
water. Wbi^n we mix it with oxidrM or sdtn that eiwily jwirt 
with oxygi-n, ii» for exiuii|>k> with oxide of mercnrj-, it is 
iostuitly conrerted into |)hasphoric acid, and the oxide is 
reduced to the metallic state. If we attempt to dlvwlve iron 
or zinc in ihift acid, sestjuiliydrcl of [tlioiiplioruN Is given out, 
and a plii)s|iluite of the iron or sine formctl. 

We Miigfit repr<>JH>nl phos^ihoraiu Hci<l as a compound of 

9 atoms pbo^horic acid, 

2 atoms phoLiiphonis. 

For 3 atoms p(>osj>horic add are composed of 

3 alomf phiHphoruR, 
7^ iKoins oxygfii. 

If to this we add 3 atoms of phosphorus, we liavc a oom- 
pouiul of 

5 atoms phosphorus, 

7j atoms oxygen. 
Now tUl 19 the same thing as 

• FluLTraii». ISICp.Mft 


IN*. L 


"■^ •• 1 atom phosphorus . . 2 

li atom oxygen . ■ I'S 

which has been shown (Vol I. p. 239) to be the constitution 
of this acid. When heat is applied the two additional atoms of 
phosphorus are separated, and coming in contact with the water 
chemically united to the acid they decompose it, and are con- 
verted into phosphuretted hydr<^eii and phosphoric acid. 

When phosphorus is allowed to undergo slow combustion by 
exposure to the atmosphere, it runs into a liquid having the 
smell of garlic, and an exceedingly sour taste. This liquid 
was considered by chemists as pure phosphorous acid, till 
Dulong and Thenard showed that during the process it was 
partly converted into phosphoric acid. According to the expe- 
riments of Dulong, this acid, to which he gave the name of 
phospfuUic add, is a compound of 

100 parts phosphorus, 
109 parts oxygen. 
This comes very nearly to 

2 atoms phtsphoric acid, 

1 atom pliosphorous acid. 
But there cannot be the least doubt that the proportions of 
these acids vary exceedingly according to tlie temperature and 
the state of the atmosphere when the acid is formed. It can- 
not, therefore, be considered as any thing else than a mixture 
of the two acids in various proportions according to circum- 
stances which cannot easily be appreciated. 

4. Hs/pophosphorovs Acid, 
I have given an account of the formation and constitution of 
this acid in the first volume of this work (p. 240). M. H. 
Rose has shown that it b a compound of 

2 atoms phosphorus . . 4 

1 atom oxygen . . 1 

It is therefore quite similar in its composition to the hyposul- 
phurous acid of Herschel. Its taste is sharp and very sour. It 
combines with the different bases, and forms salts to which the 
name of kypophoapkitea has been given. They are distin- 
guished by their great solubility in water. Not one having 



be«n yet examined whicli floe« not posses this propcrt)-, while 
many of tti4' pliospbatfa aiul phfl4i|ihit«« ntf. instihible. 

Sulptlur and oxypcn cutnbine in a great vuriviy of propor- 
lions, and furm no fewer tlian 5 acids, sume uf wliich are of 
great impurbiiicc l>oth to tlie eliemiitt and the manufacturer. 

1. Svtp/turit^ Arid. 

Thia ncitl, winch \% npon tlic whole the most essential of tlii; »B"^. 
wholo tribe, npjwiuK to have been known tn (ieber as early aa 
the 7th century. Fwr the first greiii imptnvenient in tlie 
isntliud of mannfartnrin^ it we are iitdebtwt \o I>r. Koebuck, 
wluMc establishment in Prestonpans in .Seotlcui'l w:w not broken 
up till about the year IftSfl. IVnligious improvements Iwivc 
been iDtrodticed into ibe niiflhml of making sulphuric nctd since 
tbe commL'tieenM^nt uf tiic present eenltiry, and the price bos 
been reduCT-d from ninepence |>er {Mutul lo less than three 
kalfpennr, whik- the qiuiltly huH been nilbcr inipruved. 

There arc two dilTercnt methods of making it in u»c aioor^ s«Jh««« 
nuuiufactiiren. Tlie first whieh is practiaed at Xordlutusen in 
Germany yields a dark -eitlou red fnming; acid, whieh is chiefly 
tued fur diMudvitig indij^ for the Saxun dye. In (Iit^ raanu- 
6wtary il Ik pre[KUMl from siilpliale of iron. It is beated in a 
tnlcjiiinfr fiirnan', which cxjk-Is most of the water <if i-r^xtalli* 
atjon, and at the same time peroxidiies the iron whieb it con- 
laina. It is then pnt into stoneware retorts, and exposed to a 
kont f^railiLally raised nearly to whitenci*^ 'I1ie aeid leaves 
llie oxide uf iruii and piUM-x into the receiver in com hi nation 
witli the small (|iuintity of n-uti-r which tlie calcined vitriol 
retained. Acid pr<-pcired in thn way is known by the name of 
/mKiug acid of Nordltaiisen. 

'I'be process followed in (ireat Drilain, and which ha« been """rtiwo. 
adojiied in most other countries, is much more economical ; but 
the acid which it furnishes contains a greater ([uantity of water. 
Large chainl>ere are erected liiu^! with sheet-lead, about 70 
feet long, 'iO witle, and as miic)i in height. At one enil of 
tbeM duunbers is a kind of benrth, tlic diiinney of which com- 
municaies witb the chnmber. On this henrtb tlie sulphur from 
which the Kulphuric acid h made i« put and kindled. By a 
very iugetiioiDt contrivance a strong draft of air is made to puss 
liver this lieartb into the duunbcr, no tliat the sulphur bums 
briskly, and is convened into sulphurous acid, which passes 




'*^'- into tlic Icmden diiimbcr. Upon tlitf burning oulplnir U pUced 
an iron biuiii, contuiriiiii; a qiiunlity of siltiietxe, mixed wiUi 
the requisite quantity of Ntilphtiric ucitl to jiroihtce coni)ilt:tu 
<Iecon)]>o8ition. The hent of the burning; t>ul|i)iur in MifHcient 
to heat this mixture siifEeiently high to drive ofT (he nitric iirid 
in >'n|)our, u-hicii passes into the leaden chamber mixed with 
the tuIpliurouH acid. Thv bottom of th» b-adeu chajnber i» 
covered with wiUiT to the dojith of about 4 inches. The con- 
sequence of this is timt the uir of the ehnmber iiUvuys Oi»it»ins 
» quantity of vapour of water. The nitric acid fumes speedily 
convert a portion of the sulphurous acid into sulphuric and, 
which falling by its weight into (he water, at the bottom deut- 
oxide of lutole in ilincn^ruireil in the |r:utc(>ii« fonn. It speedily 
unites to an atom of oxygen, and is i-unvurtcd into hy])0nitrouR 
acid. Now when hyponitroiis acid, sulphurous acid, and %'spuiir 
of water, meet together, they imite and form a crystalline body, 
having considerable re&einblancc to glauber salt in its appear- 
ance. This Eiatine matter is probably a c<iin])ound of 

1 atom ■uljiliiirinii* aciil, 

1 atom hyponitrouN acidi 

1 alum wutcr. 
When it comes in coiitjict willi water, the liypDnilrouH arid 
juirlx with un iitom of oxygen to llii- Milpiiurous acid, and con* 
vert.-< it into Kiilpliuriv acid, while tlie (leutnxide of n/oteitito 
which it is converted makes its eocape in the gt»eoui( »liile, and 
when it comes into the nttnosphere it in again converted into 
hypoiiilrous acid by cuniliiiiini;; with un atom of oxygen. It 
again unites with sulphurous acid and u'nter: and thus tlie 
proc<'iw goex on till the whole sulphurous acid is converlisl into 
sulphuric acid. 

This process continues til! the n-ater at the bottom of the 
leaden chamber haA become impregnated with as mueh sul- 
phuric acid ax it ciui take up. Iik specific gravity is now t*75. 
To concenlnite )t further it wi» the custom to put it into glaas 
retorts, which were exposed to a heat of above 600". 'Ilie 
water passed over along with a cunmiderable qiuuility of acid, 
and tliv sulphuric acid remaining in the retort, wsis us mucb 
concentrated as il couhl be by simple distillation. Itut of late 
years lai^ cylindrical stilN of |iludnum, furnishetl witli plati> 
niitn heads, have been introdneed, which is found (o aitwwer 
much belter; lii'e4in»c llie retorts, when exposed to so high a 
tein|ier«ture, were very apt to be broken, to the great injury 
of tlie manuliicturer. Formerly the acid was taken from the 


chambers IWoi^ it luul rcarlii.'d the spcellic gravity of 1*75, and ^t 

was conccnlnitwl in largv Icadoii boilers. Tliis occttiiooed the '. 

ipmcncs of a little sulphate of lead in tlio swid, wliicfa is now 
fwroided by tlie preiveni pr»cc>.< 

One of tlie targost nuuuirac't«ric« of sulphitrir iiciil in tliis 
Montr)- is tliRt of Charlrs Tonnant ami Co. ut St KolliH-k, 
near Gliu^ow, wborv iiboiil *;!(H),000 lb». of the acid arc mode 
wtekly. This prodi^ou<i qiiniitity of acid (and there are many 
Dlllcr Diuken) is all consumed by llie Meoclivn) and chemical 
nwnitfarturcra of Great Dritain. Wry little of the acid is 

The sulphur from uhicb thin acid is made is imported from 
.SjcUy, where it occun in immenHe quantity in a formation which 
Mvms to be newer tliaii the secondary rocks though there Li 
no evidence tliat it is rolcanic. Sicily fiirniHlifa sulphur of 
I Tuiaus degrees of purity ; and the sulphuric ud<l makers prefer 
the secoiul (jiudily (o the first, because it burns belter. 

When tlie fuming acid of Nordluniscn U put into a glass 

retort, and distilled by a modcriKe heat (tlie receiver being 

Burrouuded with ice), tlie fuming; portion comes over lintt, and 

Inay be obtained in a strparulc stale by slopping the distillation 

■in time. Thu« obtained, it constitutes milphuric acid in a fttatc 

lof absolute purity. 

Jn ikts slate it is solid, and appears as if it were composed m",'^!^"^'!;^ 

^ silky filaments. It b tough and difficuU t» cut, and bears 

■'MnaidenLble resemblance to the uiincrdl called asbestos. When 

expoAe<l to tlie air, it fuoiej> strongly, and graduidly flies otf in 

rafioor. It may be iiehi for some time between the fingers 

without any seusiblc action on the skin; but, urtcr a oerUiin 

^time, a scns;ition of puin is perceived in tlie interior of the 

Sngers. It reminns solid at a temperature at least as high iw 

but when the heat is increased, it acsumes the form of a 

Fwlonrless vapour, which beoonies white when il comes in ean- 

with moist air. I I«ive sometimes uhuiineil it in iranfipa- 

[rrni rhombic cr)'staLs ditTcring very little from a right angle. 

Id such case* il ha«l combined with a certain qutttitity of water : 

lit much \tm tbatl exists tn the fuming acid. 

The solid acid becomes liquid, aeconling to BuHsy, when i-i^nin. 
ted up to M% and at thn tcni])cniture of 68" its speciliegm- 
lifity is 1 -97. It is ratJier hazardous to liquefy thi* acid, because 
nnrnvertcd iittoagusata tcmpemturcnot mucJi higher than 
[Its point of liquefaction. The specilic gravity of this mjiour 
dotibtlem 3*7777, since it is a compound of 1 volume of 



°*'^'' sulphurous acid and half a Tolume of oxygen gas condensed into 
1 volume. 

When dropped into water, it combines with that liquid so 
violently as to make a noise similar to that made by a red-hot 
bar of iron when dipped into water. When the quantity of 
acid is considerable, a kind of explosion takes place, owing to 
the suddenness with which a great deal of lieat is evolved ; but 
nothing isextricated except water in the state of vapour. When 
united with about one-fifth part of its weight of water, it is con- 
verted into the common concentrated sulphuric acid of commerce, 
which is a hydrate of sulphuric acid. 

From the experiments of Vogel, it appears that absolute 
sulphuric acid is capable of dissolving sulphur, and of assuming 
a blue, green, or brown colour, according to the proportion of 
sulphur held in solution. Phosphorus decomposes it, and absorbs 
its oxygen with such impetuosity as to take fire.* 

The specific gravity of Nordhaiisen acid Is r896. When as 
strong as possible it is a compound of 

2 atoms sulphuric acid . . 10 
1 atom water . . . 1-125 

But it most generally contains more water than this. The 
weakest acid that I have had an opportunity of examining was 
a compound of 

4 atoms acid . . 20 

3 atoms water . . 3-375 

Such acid when heated gives out rather less than ^th of its 
weight of solid acid. The weaker the Nordhausen acid is, the 
higher is the temperature at which it freezes. I have had it 
capable of congealing at a heat of 42°. 
Hr<in»iMdd. The concentrated acid of this country b a transparent liquid, 
like water, and having somewhat of an oily consistency. Hence 
the old name of oil of vitriol, by which it was distinguished. 
Its taste is intensely acid. It reddens vegetable blues, and 
speedily chars those animal and vegetable substances to which 
it is applied, especially if its action be assisted by heat. Its 
specific gravity when in a state of purity, and as much con- 
centrated as possible, I find to be 1-64236. When it is higher 
than this it contains some foreign salt in solution. 

Its specific gravity, and its boiling point, vary according to 

* Vogel; Schweigger'a Journal, iv. 121. 

^^^P Htn.piiuiiic ^^H 

B tbe proportion of WAtet n-hicli il contains. Tho following rpry <>« L ■ 

flKUlB, czbiliits n latoifiicuny view of both of these rariatioit^.* ^| 



A(M r" HflL 






*<M W<W( 

b; 1>Tt«M 

br nwfcufi-- 




1 + 1 














































































1 + 2 



















































I + 3 











1 + 10 






1-30 + 



I + 17 






1 + »^ 10 





^M Pare acid of the -ippcific ^vity 

•842, is a compotmd 

.f ■ 

^B 1 xtatn acid S ^^H 


1 atom wal 





^P It >a )>ut mivly tliat it occurs in commerce to conciMttTntcd as 

1^ l]ifai ; ibnugh its specific fjTiivity i* oflon higher. I ■345 is n 

vprj- common s]>ceilic gravity of thi: arid of commerce, aiid it 

ta fi¥i]uently oa low na 1-837. 

^H • New RrOan of CliMni>»l Pliiioannhv. ii. lOk 




Ouv. ■■ Wlien aiiliydrouii Hu1]))iiiric ncid vniiour 'f* tnmie to ]>um 
through a red-bdt |iort'elaiii tu)><N it in (lri.-(in)])ciNi-(l into hiiI 
pLuroiL'^acitl and uxyjfcn giuio^ in die pro|>ortiou of two volumvi 
of tlie fonncr to oiii- of t!»> lattvr. 

^^'llOll cxpoKud to n siiffi<-icnt dcgwc of oold, it (Ty»tallix«8( 
or frevzcs; and aOcr ihio lius oiice t^kon place, it frc-vzi-s again 
by tlie application of a mucli inferior cold.' Morveau frosie it 
at — 4"; it a-wiiined the appearance of frozen snow. Afler 
the jirocess bc^in, it went on in a cold not nearly ho intense. 
Tlie scid mvlterl «lowly at 27-5° ; but it froze again at the same 
tf mporalure, and took five days to mi-U in tin* temperature of 
Vy.-f Cliaptal. wlio mnniifiietured this ari<l, once observed a 
large ghan vewiet full of it crystflllized at the temp<-ruttirc of 
46". ThoHc cry^tul.t were in groups, and con§iated of flat bexa- 
hedral prisms, terminated by a Kix-«ided pyramid. 'Iliey felt 
hotter than the surrounding bodies, and melted on being 
handlei].^ ('baptal lias observed, that sulphuric acid, in order 
to crystallize, muiit not be too concentrated. Tliis observatioii 
has tx-en extended a good deal tarther by Mr. Kier. He fotind 
tliat Ktilphurie aciil, of ihe specific gravity of 1-780, fr»>ze at 
45" ; but if it was eitlier much more or mucb lei« concentrated, 
it required a much greater cold for congelation, j Vhcn aa 
coiiceiitrated m* possible, I find tliat it mar he cooled down iu 
thennomvler tubes to (lie temperature of — SG" before it con- 

Sulphuric add luis a ver)* strong attraction for water. Ncu- 
inan found, tliat when exposed to the atmo«]>bere it attradnl 
6**i3 times it« own weight. Mr. Gould found, that I80giiuiw 
of acid, when exposed to tlieulmoNphere, attracU'dfiSgrainsof 
water the first day. 58 the second, 39 the tliird. H'd the fourtli, 
IB tlie fifth, and at last only 5. 4, ti. 4, :(, &c. The 2Slb day 
the augmentation was only half a grain.f The affinity, tlierc- 
foTCf between sulphuric acid and water, as U the ea-<e in general 
with other Mib»laiion(, became^ M'eaker the ne:irer it appruuchea 
to saturation. 

Concentrated snlphurie aeid hiu the property of dissolving 
seversil simple bodies without altering their nature. Vo^d 
sliowed that the fuming aci<l dissolves sulphur, Muller of Reich- 

■ The freeiing point wiu ntccriaiiicd b; the One d'Ajni in 1770. Sec 
'Uaoquer'a Diciiomry. 

t Enc) d. Mrthocf. riiini. i. 376. ( Jour, de Phyfc mxi. +73. 

{ Phil- Trann. Usvit. Pert. ii. 

I Sec t¥>l. i. ]h ao, fotfihe lew of itiCongeUtiuu. 

t Phil. Truu. lOM. 






IMr. I. 



Uial it illtaolvm telluriuRi. BittMy fuuml it to dissolve 
•wlui«>, and it i« ca{Mi1>^ iAm »f ilbmlving :^l<>iiiuin.* 

Many of tlir iiai[>ltt bodies Law tlic j)ro[KTty of di><.-om|)<i»- 
ic^ tbw acid, especially if asnated by lieut. M'hen tiie vapour 
cf anliyilrniiii i>ei<l and hydrogen gaa are |>a»ie4l ihroiigli a red- 
biX )>«rcvb>in tube, the acid uitderj^oes decompoditioci aiid water 
b fbfiDMt Wlicn the vapour of the acid i« piiswd through rw\- 
ko( chHrcoul, nsiiniU(rdv'cuiii;uwtliun lnki-<t |daoL-. Wheiiphos- 
pkoriM is pUceil in coiiUict with litifiydrous sulphuric ticii) it 
tnkea fire and burns at the expense of tlie ncid. Anhydroufi 
|ibo«[dHirii- add aiid Milphur are depusiteil on the inside of the 
tube iti which thv itiixmre was miule. 

When xine or iron is tlirown into sulphuric acid, a violent 
UCSou l&krs plnee, if the add bo diluted ; water in decomposed, 
its hydrogen flics off, and \t% oxygen combines with tiie metals. 
If tfa« acid be concentrated, the action i§ much less violent, or 
time is none, unles-s heat be applied, when sulphurous itcid 
exbak*. Upon tin and cop{)er the acid acti vt-ry ^slowly uiid 
liwblyt tmlcn itA action be as^Uli^d by beat, when it oxidi/cs 
and dmolvcA tlicm. On »ib'<>r, nivrciiry, antimony, biitinutli, 
■neiiic, and tellurium, it docs not act vxccpt at a pretty bigh 
fcmprmlure. These metali abstract part of its oxy^c". and 
eoarrrt «nr poTtion of it to sulphurous nciil, while anotlier por> 
tion comUnrA with the oxides iIium formed. When boiling hot 
it ondixea lead, and dixHnlvi-? coblll^ nickel, and molylidcnum : 
but it haa no perceptible action on gold nor platinum at any 
leiMperature to whkli it can be mised. 

When awiisted by heat it dissolvesand destroys almost all the 
nNnponnd oombuAlible bodies; tliough with mnnc it luui the 
pn>{Mrrty of uniting and forming new add»; which will be 
deKribtfil afteru'urdi when 1 cunie to give tui account of the 
oxyf^i adds with compound bases. 

It abvorba oletiaiit gas to the amount of two or three times 
ha vuluinc of it ; but whetJier the nature of t]ie gas is altered 
by tliis absorption, haH not been a'icertaine<L 

It tnts accidentally di«covcrcd by K iri-liIiofT, n Russian ohiv mmmiB 
nbt* thnl when slarcJi is boiled lor some timi- in dilute «nlphuric 
mU, it is converted into tniffar. Braconnot iiHcnvards found 
tkat WoihI, bark, i>traw, hemp, and many otiter boilies wlieii 
Inatrd in tlie ennic way, are alwo convi-rted into sugur. And 
hr hnabuwn more lately tliat whvn jtl/ff or ff/ue b dissolved in 

• Ann. de Cbiin, et ile Pliys xtitni. ISO. 

36 K]Mn.K OXTGEN Acins. 

ft Mn»i^ !inl]itiuric iicid, unil tlio solution boilrd otter aufEcleni 
diliilion wild water, it in converted into anotlipr spc«i*is of 
sii^ir, <)t«titi^iUlifi) by tlio gr^it readiiinta urilti wliicli it cr)'s- 

Many vcgctnblp §ut>stances i?onlatninK oluircoiJ a* » coiwti- 
tticiil, bUckeii sutpliuric acid. 'Hie reason seems to be, tiiat in 
consequence of the grent affinity of this arid for waU'r, (ho 
oxygen ami bydrojjt-ii of tbo body unite and fonn w^ter, and 
tlui>> (be cliarciial bi^'inj; di<ii-n^t);i-il bliirlcon.t tJie acid. If we 
dilute the iicid with wutor the churcoid 5ilU in the Atate of a 
black powder. If we boil the arid the churcoiil U acidified itt 
tlie e.tpeiLse of the aciil, which in consequence becomes again 
limpid and co)oiirles.s. 

I liave already »l)Owii (Vol. I. |i. 263), (hat Kulphuric acid B 
a compound of 

1 a(flm tiulphur . , 3 
3 atoms oxyj^n . . S 

BenteliuH assures us that anhydrouM Mtlphuric acid may be 
procnfi'd I'V the foUowinij jiroces* ; Mix (hrec partj* of.inby- 
druiis Knlpbiitc of m»\ix with (wo juirts of concentrated tiuljibnric 
acid of commen-e, and gradually heat the mUlure in a covered 
cnirible to incipient redness, (ill (he boiling occasioned by the 
escape of the water of the acid bun ceiMcd. \N'heii the nutas 
formetl Iui8 cooled, break it in |)iccc« nml put it into a poro'lain 
Tolorl, aitd distil at ii rod hcni. The acid which comes urcru 
to bo collected in a )rlius rverirer surrounded with ice. Hitt 
acid bccomcH solid in (lie receiver. It bas u^uallv a dark 
colour, antl is not absolutely free from water. Hence it forms 
cr)*Htals destitute of the tenacity, aiid quite dilfiTcnl in their 
appearance from perfrclly unliydron* arid. IJut if wo di^til it 
again at u low (empcruture, we will obtain |>crlWtly unhyilrous 

Douhllest tbe Besqnisutphate of soda, wlitch is anhydrous and 
MHily obiaiiied, might be employed witli udvuntafre for furnish- 
In^ anhydrous sidjdiuric add. 

There anr few aridw mure powerful than sulphuric urid. On 
this acoount, and also on uccotint of its cheapness, it is more 
employed in chemical processes than any other arid whatever. 


Ann. *k Cliim. et ile Vhyt. sin. I IS. f Bcntelius, ChiiiM, ii. S. 



2. Sttipkiirotu Acid. 

Solphonitu umI is utmally pr«par«d by hcadng a mixture of 
nlpburic acid and mcTctiiy in a small retorl. 'nit: gjw must 
be collrcted am mrreury. When our object U (u propitK it 
in larfTC quantity, as for th« foniution of milpliitps, u (food 
netliod ia to mix suljiliurii: avid wttli tbe sawings of wood, and 
apply beat to llie mixture in u retort. Bcrtliicr recammeud>i a 
mixture of four ftau of flowers of sulpbur, with five part« 
«f tcr<>xi<]c of nuin^new reduced to fin*- pou-dor. He Hays 
that half the sulphur is i-onvrrtnl into Hulphuroiis nvid, while 
tke otlier half uoiles witli lh<- proto^idr of mmifrHnesc. I tried 
thu procetM, but no sulphurous acid was extriailed by tlte heat 
of a <>{>ini lump. 

Suijtliuruns acid at the usual tem|>erature of the atmosphere 
is a gas. Uut Mr. FanuLiy iliscuverti) that l>y a prc^-ture of 
two iilmoHpheres tlus pk% mi^ht bo condensed into a liipiid at 
die temperature of 45". M, Du.'isy lutt wne* examined the 
liquefection of tbia gas, and shown tliiti it may be produced by 
means of a freezing mixture. He lirst pasted tbe gas tlirougb 
a ve.-Mel surruuiKled with ice, to condfiiTic the {greatest port of 
lii« aqueou* t-apoiu- which it contained, iiiid to dry it completely; 
il then pttwed through u luhe Ulled with fragment* of dry chlo- 
ride of calcium. It finally passetl into a small matrass, sur- 
rawMled hy a freezing mixture composed of two jiarts of snow 
or icfi and one pun of common will. In tliis liut vvs-iel die giut 
(ondenKS under llio mere pressure of tlic utmovphcre. 

Liquid !iHlphurouj) iici'l w a IriinviKircnt colour! cm liquiil, of 
the ^pecilic f;nivity I'45.' It Iwitsut the U-mprnituro of 14% 
bat produces so much cold by evaporating, that a portion of it 
continues for some time liquid even in the open air. If a little 
«f this liquid be drojit upon wati-r in a watch glass, the cold 
produced by ita evaporation speedily converts the water into 
ice. Even mercury may 1>e froxei) in tlie same way, by 
eornitig a globule of it with this liquid acid :uid pbciug it in 
tba vacuum of n reccivor.f By this procc«H M. Huwy tunk a 
thennofneter to — 66°. 

M. dc la Kivefound that liquidsulphurousacid isunon<on* 
ductur of aWclricity, but it \teoamet a conductor when u Uttb 
water is addml to iL Itm rcfmctiafr power, according to hii 




• Faradsy u$u* it u i-ii, wMrh tiidtn hut iktlc 
i Aao. d« Chin, cc ik Pbj*. xxn. (iO. 

nup. L 


experiments, diffvn very Utile from tliat of water, and is 
taialy not loss than the refracting power of tliiit ]i<tuid. M. de 
lit Rire Vitscovered tliat when lt(|uicl su)phuroii§ itcid in prepftrei) 
by Bu!«iy's method, white crystals are formed in ihe first tube 
surrounded hy ice. 'I'hese crysLils are white, have a wmr 
taste, uiid are in the f>tiiie of thin plates ^imtlar to the solid 
(lecihydrvtv of vlilonue. They renuiin solid at the lemperaturo 
of about AQ". Biit at tliut temperature they hegin to give out 
ga% and when the temperature is a little more elevate<l tliey 
are entirely resoked iuto sulphurous acid gns and water.* 
According to de la liive'.s experiments, these cr^'Htals are com- 

^ sulphurous acid, 
S water. 
This approachss nearly to 

1 atom sulphurous add , . 4 

14 atoms water .... 15-75 




But lie is of opinion tluit the quantity of aeid was greater 
than what he obtained, and is inclined to consider the crystals 
as composed of 

1 atom sulphurotts aeiil . • 4 

10 atoms water .... 11-25 

Atwiniootor Water, by my triaht, absorbs 33 times its volume of sulphur- 
ous acid gas. But Saussure obtained an absorption amounting 
to 43 J volumes, while alcohol absorbed II5J volumes, ITic 
speeific gravity of die saturated solution I found l'0510. The 
water saturated tn my trials was » compound ^if iibotit 09 atoms 
water and I atom acid. Sausiture (who pntliaMy made his 
experiments at a lower temperaturi; ih.-m [ did) obtained an 
acid rather stronger, but still very weak. 

This water may be frozen willioiit parting with any of the 
ncid gus. Mlieii H'ater, whieh has been saturated with this 
acid at the freezing temperature, is exposed to the heat of 
65*35*, it ia 611ed with a vaAt number of bubbles, which con- 
tiimally incren:4C and ri«e to the surface. These bubbles are a 
part of the acid separating from it It freezes u few degrees 
below SS'.t 

• Ann. At Chim. «t de Phys. xl. 401. 

f Fovrtny knd Vaii(|iidiii, NicholMii'a Jour. i. jl3. 





Oxygen gu uiil sulphurous acid givt do nut combine ut the 
eomniou lemperaturi' of the air if they arc kept dry. But if. 
oilier l>e present they gradually combine, and are converted 
into sulpEiuric iicid. When passed through a ml-hut tube, or 
when olirc-triviil itpwks ore paxsed through the mixturtt, tliey 
ooinbinc likewiM' nnd coiutitiitc sulphuric iicid. 

t^lpburouH avid is one of tlic wentwl of the adds, Tbe 
I -soltx wlitch it forms with bases bave received the mime of nid- 
phiU*. W'lien exposed to the air iu solution in wuler, they 
gradunlly nbrarb oxygen and itn- converted into sulj)hiite«. 

U m readily deeompowd by potiHsium and sodium. It 
dHolvm iron without the evolution of any gas, as vnts first 
ab«enrrd by Mr. Higgia<i.* When exposed to tlie action of 
peroxide of lead it is absorbed, as Berzelius first ascer|june<l, 
ami the peroxide «onverteil into ntnimon :<ulphiUe of Iciid.f 
feroxide of niangaiic«e produces a simttur change in tbis add. 
Tbe Adion of the remiuning tnetals and their oxides on this 
uU gaa U still imperfectly known. 

Thin »cid does not redden vegefciblo blues but destroys ihcra, 
proniled it be free from all admixture of mitpliuric ncid. If 
the petab of n red rose be put into sulphurous acid, they imme- 
diuri-ly become white, Init recover their n-*i colour nguin if 
jdunged into dilul«il sulphuric nctd. In eonscijueitce of this 
^mperty which it luis of destroying colours, tlte fumes of burn- 
htfi Milphur are cm]>loyed for blraching iliinm-l. 

Sulphuric acid absorbs tlw gas in considerable (juuntities. 
It is absorbed ubw by bomx, us via finit observed by Dr. 
Priestley, and may by iu means t>c separated from carbonic 
add when they liappen to be mixed together. Mr. Aecum 
says tluit it is decompo«e4l over mercury, and sulplnirdopositcil, 
if it be brought in cuntnct witli protochluridc of tin. 

I liave already shown (V'uL I, p, 26;)) that this acid is u 
compound of 

* I atom sulphur . 2 

3 atoms oxygen . . 3 


VfWUlili: toim 

■ that Ita atomic weight is 1. < 

3. SubtttlfAunma Acid. 
It vaa fimt olniTVod by Vau()ucltn that xinc dissolves in vntemmt' 
■ulphargua add wiiliuut the evolution of any gas, and that the 
* ll%sia>' Compvativc View, p. to, t rbil. Trunit. 1013, p. W9. 


oiwi- soIuduD vhen e\'aporale<l yietcUu ))i.-ciili«T Mill, which lie <)t»- 
dn^iUliod hy Uu- luuiw' of ^iilpluirvttfd oulplinU- uf zinc If 
tlie Molution be con<lucU-cl by a uniform luid Dot loo i.-opiouii 
istrcjun of gtilphuroiiH acid gas, there is no effervesoencc what- 
ever. But when the iiupply of aci<l is too great, th« liquid 
becomes Iiot, and an offer vesceiice (akiM pUive. WTien the 
Holutton tinn tuaile a ceruun progress it hoM al iintt u browni.sli 
yellow colour, hut tItU colour diiuippcars as the process i^oes oil. 
Wb«ti thift solution 'u evaporated it becomes a thick white 
magma, ui which crystals coi»Utiiig of four^Aided prisms muk« 
their appearance. The salt tlius obtained is in general a mix- 
ture of tuipltife and mibsuii>hUe of zinc^ but w« may separate 
them by means of alcohol, wliU-h touvcs the sulpldb^', but diH- 
eolvcs tlie sub§ulphite of zinc. This last salt dissolves both in 
water and alcohol. It lias a pungent and excessively disagree- 
able taste. If we drop an acid into its a((ui-<>a« nolution an 
effervescence Iake.«plaee,a]idubundanc«- of skilpliurprecipitaleii. 
1 comtidor thin Kidt as a ctompound of oxide of vine and a 
peculiar acid of sidphur, to which, for want oi a better uame, I 
have given the appcUation of gubautpkurom acid. 1 have made 
eome attempts to procure this acid in a separate stale, but lliey 
were unsucceittful. It iteemB to undergo decoinpoiiition the 
instant it is Hcpoiutcd from the oxide of nine There is no 
difficulty, however, in dctcnnining tlie proportion of its cou8t^ 
tucnls. Sulphurous acid is a compound of 
1 atom sulphur 
'2 atoms oxygen. 
M'hcn it is made to act upon zinc, it dii»olves the metal with- 
out effervescence. But the zinc is converted into an oxide iii 
the first |)laee, and for tliis change every atom of it requires to 
combine with an atom of oxygen. This oX)'gcu is supplied by 
the sulphurous acid. And as every atom of the add is capable 
of combining with an atom of oxide of zinc, it is clear that the 
add must part with half of itA oxygen to oxidiice tlte zinc. 
rMDiaiiion. Consequently tlie subi^ulpburous add which exists in the salt 
must be u compound of 

1 atom sulphur . . 3 
1 atom oxygen . . 1 


and its atomic Weight must be 9. 

^^'hen an acid separates tlii« add from the oxide of sine, it 
resolves itself into sulphurous ncid and sulphur. One half the 

f nlpliur pi 

iiirposuLriiuBous acid. 

mlpliur precipitates, und iictd tliiu altered in obviotuily reduced 
(■ lb* Mair uf common sulplmrous acid. 

WWn sulphurous acid is niade to nd upon iron, a aubsul- 
pkitr uf iron is formed quite similar to tliv huliNuIpliite of sine, 
km it is nut kiiowti wkcllieratiy of tUe otLcr mvtals urc capable 
of iudui*ing a similar cluutji^c. 

It is nifirnu-d, that tf sujpliile of ziiic bo hoUeA in a clow 
L-1 witli sulphur it i* converted iiilo neutral aubsulphite of 
I Imve not tried ilii« experiment, but if it he eurrect, it 
would indioite (hat MulMiilphurous add is ii compound of 


2 atoms sulpkur 

3 atotns oxygen 



umI lliat its atomic weight wa» 6. But this expliinution would 
mK acvurd witli iLi- known fact tliat zinc is oxidizi.'d by sul- 
plmroiw acid without etfervescciicv. Tlic tmit fonaed by boiling 
«B]phit4) of zinc nnd sulphur ought to be a bisuWulphite of zinc. 

4. Jlifpoaulphuroiu Acid. 
F«r otir knnwU-difO of the exittlrnce of tliLi acid we are 
tiubtl»«cl to Mr. IlcrsciicU. lie formed u numerous class of 
nils to whicJi lie gave the name of hyposulphites.* 

When sul|ihuTet of ojdoitiin iw dwsolved in water we obtain a 
greeni^ yellow eulountl noUilion having the smell of suipbu- 
tvUed hydrogen gas, and precipitating all the metala from their 
•olatioos. If this liquid be preserved for some lime, it gru- 
dually becomes colourlesH and loses its peculiar «inell. If it 
Im mm- i-vaporated it yields large cryiitals, most conimonly in 
tba aluu- of six-sided prisms, and having an exceedijigly bitter 
nwe. They ninsist of hyposulphurous acid luid lime united 
together in the following proportion, according to Mr. Uer- 
»c)irir« aualysia : 

Hypotulpliurous acid . . 36*84 

Lima 3214 

Wtkca 4I-22 

From thin salt, which b easily procured by passing n current 
of sulphurous acid gtu through hydroguretted sulpburet of lime, 

* Edinburgh Jour- i. 1^ 





f^^ ■• the otlicr )iyp03iilpl)it<>8 may be ron<lily oktaini^tL Tliesesalls 
are folotirlo«-t, ami, with lut exceiitimi or two, they aro soluble 
ill M-nler. Their l«»tv is mo«t cotninoiily biltvr; thunj^h wme 
of the niPtalluic hypmulpbile!) hare an intensely awcct taAte. 

I liave stated (Vol. I. p. 2B7) tliat an examination of a hydro- 
suljihuret of Noda whluh acciilcntiklly crysialli/i'd in Mr. Ten- 
nunt's «oda l«y« during tho wurni numnier of 16'2.i, and tlio fl 
conversion of it into hyposulphite ofttoda by me.iiH of Asulphu- 
rous acid, left no doubt tliat ibis acid is a cunipound of 

2 atoms sulphur 
I atom oxygeu 



and tliiit was confirmed by tJic direct analysis of mme of Mr. 
Herschell's hj'jtoBulpliites formed by the process which be fjiv^-i) 
ill his paper. Oay-Lussac is of opinion ibat hydrogen also 
elilT^ into the cnmpoMtion of t)m acid.* l)ut if this were so, 
It would be inipoNfiibW to account for the prociptlaiion of nuI- 
phur when unlpburoiis acid is mL\cd with a solution of bydro- 
sulphurct of soda. Out hyposulpburous acid diifers from tliv 
bi«ut|^urctted bydrogea of Hertiiollet merely by the substitu- 
tion of an atom of oxygen for tlio atom of hydrogen which the 
bUulphurelted hydrogen contains. 

HypoitnlphitrouHacid <nnnot exist in n sc;Kimt« state. When 
we attempt to decompose tlic hyposulphites, we always resolve 
their iic-td into sulphurous acid and sulphnr. 



5. Uyposulphuric Acid. 

I have already staK'd tlie bUtory of tlie diseoT-ery of 
acid, the method of obtinning il, and the properlies which it 
pi>K«eH«es in the first volume of this work (p. ^9). 

It dissolves line with the dUengagement of hydrogen gas. 
^\^len cold it is not altered by chlorine, concentrated nitric 
add, or red Hulpliate of manganese. It ftaturates the different 
bnses, and seems to form soluble salts with all of them. To 
these salts the name of byitosulphates hus been given, 

Gay-l.u5!<ac an<l Welter have idiown that this acid is a com- 
pound of 1 iniegnint particle of snlpburic acid and 1 integrant 
particle of sulphurous acid united togetlicr. Hence its con»ti- 
tuents must bo ~ 

• An*, dc Oiim. ct ilc Phj% xiv. 361. 



S atoms sulphur = 4 
5 atoms oxygL-n s 5 


umI the e<]uiralent nomlier for it must be 9.' 

The suits which ihli add fonns (and wliich are vpt)- rurtoas) 
ban.' boon cxumiiiwl in detail by Dr. Heereii of Hamburf^.f 
An ■oGouut or ihi-in u-iil be given in u subsequent part uf tli» 


Sflriiinm, »o fitr asweknowal pn-^cnt, furnis only two acidt 
vitk ox}-gen, analogous, w br as their compontion goett, to tlie 
colplitiroiu and sulpliuric iwids. 'Hicsc acids arc the atknioiu 
aad sdatie addtt. 

■ 1. StJaiic Acid. 

H I hare fpvcu the history, preparation, and propeitiee of this 

^^^1^ so &r as ibcy nrv kiiomi in the first roliune of this work 

^B^p^SM)}. It is 8 compound of 

^1 I atom seicDiuni 5 

H 3 iitonm oxygen 3 


^ Of <»iisec{uenceil is similar to sulphuric acid in its compontion. 

TIm salts of tills acid otlled ttltniateii, have hitherto bern very 
iiBporf(>ctly I'X^niiniN). 'lln-y ulinocit (.-xaclly rcsemhk- tlio cor- 
responding sulphates Itiit we may distiuguisli them by tlie 
property which tliey have of detonuling when heated to redness 
with eliareoal, and by disen|;pipiiif? clilorinc when boiled with 
nurialtc and. The acid is disonguged from \\» buses by sul- 
phuric acid. Seleiiic and sulphuric acid are isoinorphous bodies. 


2. Stlenioui AviiL 

'I'hui i« the acid to which Berzeliits in bis original paper on 
selenium giivo the name of w/mtc uri'i/. I Imvc d^^seribed the 
method of obtaining it and Mtmc of ito properties in the first 
volume of this work (p. 390),' 

\\'Iien the erptak of this acid are exposed to the air, they 
lone tbeir Instre and adhere to each other, doubtless by absurb- 
iay moisture from the atmosphere, but tliey do not deliquesce. 

■ 8m AniMb or PhiUi*oj)hy, xir. 'Sbt- 

f PogieiKlorrs AnnolcOi vii> 74 Uid 171. i 

Dl*. t 





**»*■ It* tafit« of the acid is §our and hoi, and its smell when i» die 
state of v»|>our U similar. It i* fxceM\n^ly soIuWp iii boiling 
wattr, iiiid vryMiillizvs 115 thy sntiinitcd suliilioii cools. It dis- 
)tolvt'« nUu abutidantl)' in alcohol, und when the solution U 
htntt-d it give<) out the smell of ether. But Bi.T70litis did liot 
succeed in obiaitiing any ether hy diiitillinj^ a solution uf iilvo- 
liol luituniteil witli tiiis ucid. A ]ilute of zinc or of iron put 
into 11 stilution of sc lemons add in w»ict, throws down selenium. 
And accorduiK to Fischer, selenium i» thrown from it by nil 
tlii^ metak which precipitate silver from it» solution in nilric 
acid. Dul selenium iw not preeipliuted by any of these metaU 
from seletiic ncid, shon'tiijj; that thin hut is more diHicult of 
decomjiositioii than the Bclenious acid. 

'i'hc selenium is eiutily precipitated from this aciil, aiid ohw 
from tlie stletiiie* {ns tlic sall.t which it forms are callwl), by add- 
ing on acid to tlit! ioliitii)ii, and then mixing it with vidphileof 
ammonia. The iselcnium pn-eipilates in about 12 hours hut 
not comph'tely unless we boil tlie liquid for wirae time, adding 
occasionally aulphiie of aniroonia. The constitueiiU of this 
Bcid are 

I atom 8«Iciiiura . ■ & 

1 atoms oxygen . . 8 

~ . I 

It is a pretty powerful acid, though lew so than solenlc add. ■ 

It decomposes nitrate of silver luid nitrate of lead. And when 

assisted by heat, it duwngage* both nitric and muriatic acid 

from fixed Itjaos. But as it is itself voialile, it is <lisplac«l iii 

its turn by sulpharic, phosphoric, arsenic, and boracic acids. 

3. Telluric Acid. 
The oxide of tellurium pojwesses botli the properties of an 
acid and a bate. I have ain-uity j^iven an account of its cha- 
raclcr*, so far aa they have been determined, in the first volume 
of this work. 


It ia uuuecessary to enter into any fiirther dclails rcsjiecling 
lite remaining 12 oxygt'n acids with simple buses, as idl (heir 
properties, so far us I am ac(|uainted with them, have been 
already given under the respective metals which conslitule their 
buses. 1 slwll merely stale their names to rccull them to lln: ^ 
reeolledion of tJic reader. 




I. Ar*«nic forms two aeub, the antmitwa and arsenic, the 
W of which MitcbeHidi ha* tilioMi) to bo iHomorjitiou^ witli 
liuf phodplioric acid. 
3. Antimony fornu two ncwU, tii« antimoniotu imd antimoi^ 
in their conitlitiilioii to the urscnimiK und iirsi-nic. Rose 
khrwn tluit itrsvnic siid antimony are iaoinoTphoiis budicsi. 
Tlie adds of the two mctaU being similarly conatitiitcd, ouj^ht 
tkn til be i4flmnr|i)iou!i hivlies. 

3. Chromium forms only anc acid Httnilar in itit constitution 
Id tbo phoiipboric, nnenic, juid antimoiiic. Whether it be 
bouB with them has not hitherto Im<^ii exumin«<I. 
TliP peroxide of uranium posseswg the double property 
of -combining with bases and \t-ilh acids. Hence it niiglit be 
cnllnl ttranie arid. 

5. 'Ute molylMlic,tungstic,eoliunbicand titimie acitU, require 
•0 ailditiotud rrmurkn to those made while tretttitig of Uti^m 
ively in the frst vulnme of this uork. 
6. The oxide which I described in the fir«t volume of ibia 
work {(1. rdfi), under the name nf fiin-oriile of mangawte, 
M«n<i. m I have mentioned before, to be oipnble of combining 
in defiuitc proportioitM witli bases. 'Hius the t^)ccie8 of nttin- 
gaame ore. to which Haidinger has given the iinme of l^iilome- 
(niite, ajipcer)! from ilie aiiidy:<i« of Dr. Turner to be u com- 
pound of 

3 aiomit subsesquihvdrate of binoxide, 
1 Atom qiUKlroniiuignuile of burytcs. 
By qunilromanganile of bar)te8, 1 mean a eumpound of 4 atoms 
hinoxide of manganese n-ilh one ntom of Irarytes. I liave also 
famed definite eompounda of tliis oxide and time. From this 
thcwi urcmi litiU? doubt tlmt it possesses acid prf^crtii^K. It 
'Vigbt therefore be ralle<l mmujanotnntciil. 

Mwtgauie ncid pomeK^es dccidud ncid c]iaractcrt. 
It is curious to see an alknltfiiible base like mati^^ancf^.' awum- 
ing acid properties, when it combines uilb m«re oxygen than 
txvOA in ibe alkidine compounds of the siune base and oxygen. 
'Via and g;old Aeem to possess simihir e I u) meters, and prttbiddy 
the reiiMirk mifcht be applied to tli<- jj^reater number of the 
lien wlucli bare been placed under the division of nMe 




"ITi* acids of oxygen, with a compound base, are very mime- 
froiw, and nre daily augmenting as cIiemiiitM ext^Mid tlteir 





regearclies into the anitnal aiid ve^table kingdomi* of nature. 
The double luise consists most cominunly vf carfmn iinit ^f/dro- 
gen ; floiueliines of carbon, hydrogen, uiid azote ; aad tlivro are 
a few of lliem into which mlphtir enters likewise as a oonsti- 
tuent. Doubtless ihc immber of eoiistttuents which enter into 
these eoinp»uii<l Ijii^i-s, M-ilt inCTWute very nnich hcteafter, when 
the nature uf these eompound acids has been more completely 

Maiiv "f ihese aei<l:t exiM rejidy formed in the vegelabk 
kingdom, luid r(-<jiiirc only (o be disengaged from (ho oilier 
vegetjible KulistaiieeH witli which they are mixed or combined 
in the part of the plant which contains them. Tliis is the case 
M-ith tartaric acid, which exists ready formed in grapes, with 
maiic nci<l wliich exist:) in appteM, and widi vitric acid which 
f^vea acidity to lemons and limes. Some are formed by a 
Kppcies of ferroentalion, to which certain regelabie sulislances 
are liable. Thus acetic acid is formed by the fermentation of 
varioHH speciea of •tiigar. I'here are others which are fi>rme4l 
during iIk- diHtillutton of c*'rt«in vegetable liodicM. 'Hius pjfro- 
tartaric acid in formed during the distillation of tartiiric acid, 
and pt/rocitric acid during tlie distillation of citric acid. Nitric 
adtl has the properly <»f converting rarious vegetable and 
even anintitl sub.'ttanee* into acids. In this way oniric acid, 
camphoric aei<l, xubcrir;, and v»rii>u» other aeiti*, arc fomed. 
And finally, thvrc are btlier aci<Is, formed by the combination of 
sulphuric acid with certain vegetable substances. 

Ilie following table contains the names of all the oxygen 
acids with compound bases that have been liitberto examiued- 
Our |)re«tfnt knowledge of their constitution is too limited to 
ennble u* to adopt n systemntio arntngi'ment. lint in the fol- 
lowing table they are divided into sets according eitlier to the 
number or nature of tlie compound bases which are combined 
with tlie oxygon, 

, A. Acidf romfiosrd ofOxjfgtn united to Cfirhon and Ht/drogev, 

1. Acetic, 

2. Formic, 

3. Mellitic? 

4. Tartaric, 
ri. Vinic, 

6. Pyrotarlaric, 

7. Citric, 

a. PyrocJtric, 
9. Malic, 

10. Pyromalie, 

11. Mucic, 

12. I'yromucic, 

13. Succinic, 

14. Denicoic, 

15. Ctoconic? 

16. Giillie, 

17. Ulmic, 
Id. Crameric) 

19. Kinic, 

20. I'yrokinie, 

21. Meconic^ 

22. Boletic 
33. Camphoric, 
24. Su!>erict 
2d. Pec-tic 




B. fhHy Acid* composed of the tame Ingrfdientti. 

I. Solid. a Butyric, 

I. St«ari(v 9. Caproic, r,. 

'i. Margaric, 10, Hircic, 

3. C«prir, 11. Elaiodic, <t 

I - 4.^ Rjciiiic, 12. Crotoiiic, -i 

5. Cevactic, III. Kot Soajii^altte. ,1 
II. Ijiqnid. \Q, Ambreic, 

6. Oln^ 14. Clioleiiteric. 

7. l^liocentc, 

C. Rtfinou* Acids cmipoted t^the mme ConstitwKtu. 

1. Ptnic, S. Coloplioiiic, S. Silric. 

D. Acid* compottd of Oxygen, Carhon, and Azote, 

I. CaHwtotJc, 2, ludigoric, 3. Uric. 

E. Acidt amtpoKd qfOxj/gcn, H^rogen, Carbon, and Azote. 

I. Aiipartic, 0. Nilrolcuric, 5. Purpuric, 

% Xicnxtavcharic, 4. Pyntrlc, 6. Alhiiituic. l 

K. Avid* compoffdofOxffffm, H^lrogfn, Carhon, and Sulphnr. 

I. Hydru-caHwsulpliuric, -t. Sulpkoiiaptiialic, 

S. .Sulpliiiviuiv, 5. VegcUiNtilpliuric. 

•"}. Xtuilllic, 

Q. Acid* composed of Oxy^n, Uffdroffen, Carbon, Azote, and 

^ 1. Sinapie. 

The peculiar naitin> of ihe whole of these aci<k hsa not yet 
itr*a made out in a sadiifai'tury maiutor. But it m proper to 
miicn tiieiD all in a work of tliis kin<l, in otxlvr to <lrHw to 
tbon the altnition of practical clicmbts, that all uncertainty 
m)M.'ctiiig ih«-in may W rcinovetl as s|)ee(Uly as poAsiblc. I 
it []p»cribr tlicu in tliv rullowing ni-cliiius^ 




I B)dd is employed in tliree difTercut slaleti, wliiclt have »>u>t 
Wen diotingimhed from each otlier by peculiar names. When 
H &nt prepared, it is c!dli*<l vineyar; whi'n purifictl by distillution, 
H H BBHUnes tJie uame of distilled vinegar, usually called acttous 




acid by clietnists; when coDc«ntratv(l a* much on possiblv l»y 
pecutmr process*'*, \l M called nuiiml rini-r/rir, aiitl liy ch^-mists 
atvlic arid. It will be requisite to describe each of theae states 

1. \'iiiegar van known many age<i before die diteomy of 
utiy otiier ndd, fJiose only excepted which exUt ready fonaed 
in vegetables, his mentioned by Monc«, luid indeed »e«insto 
liavc been ui common iiscKmongthc Isruclitcsnnd other custtm 
nations at n very early period. It is prepared from n-ine, from 
beer, nle, and other similar liquids. Tliese are apt, as every 
one knows, to turn sour, unless they be kept very well corked. 
Xow sour wine or beer is ])recise1y the Kaine with vinegar. 

Bocrhnnvc iloseribcs the foUiiwinff method ornKikiiif; vinegar, 
which is said to be still practised in <lifl'eieiit ptacc»: 

Take two large oaken vats or hogsheads, and in each of tlicsc 
place a wooden grate or liurdle at the <!isiance of a foot from 
the bottom. Set tlie vewcl upright, and on tlie grate place a 
modemtely close layer of ^een tvrig» of frcsli cuttings of the 
vine. Then fill up the vessel with the footstalks of (^ipes, 
commonly called the rape, to the top of the vessel, which must 
be left quite open. 

Having thus prepared the two vessels, ponr into them the 
wine to be converted into vinegar, so as to fill one of theni 
quilo up, and the other hut lialf full. Leave them tliiis for 
twenty-four hours, and then fill up the half-filled vessel with 
liquor from that which is quite full. Four-aiid -twenty Iiouis 
afterward* repeat tlie same operation ; and thus go on, keeping 
the vessels alternately full and lialf full during every twenty- 
four hours till the vinegar be mnde. On tlie second or third 
(lay there will ante, in the liulf-filled vessel, a fermentative 
motion, accompanied with a sensible heat, which will gntiliudly 
increase from day to day. On tlie contrarj-, tlic fermenting 
motion is almost imperceptible in the full vessel ; and as the 
two veH«eU are alternately full anil half full, the fermentation 
is Ity tliat means, in some measure, tnterrupte<l, an<l is only 
renewed i^very otiier day in each vessel. 

\\'hen tills motion uppi-un to have entirely ceased, even in 
tbehalf-filled vessel, itisasign that the fermentation is finished; 
and tlierefore the vinegar is tlien to be put into casks clom 
Mopjied, and kept in a cool place. The process in summer 
usnally last«i fifteen days ; in winter it lasts longer.* 

■ Anaccount of tlie tnodeDTRinkingrincfttirin France, AtmoM prttniSf 
the MRis with Ihnt given in the te:iit, wha puUii)i«d in the Philouiphictl 




Mnt-gmr in tliia country is usuaily made not from wine but 

tbc malt of barley. Tliis malt is ground nii<l ina.ibe<l with 

wa(«r. The fraeei sotutton, knovni by the natna o( yrottt 

KWB off ood fenQeiito<l in tlic usual w-uy. It U ibeii [nil 

Bto beirels, wtiicli are arr»ug«'<l In Mom witlt their bungs out, 

Find ke])t in a icinpf raturo of tibout 84°. Tliv liquid id gni- 

[dually t-itaii^ed into viiK-gor. 

(X late years a great deal of ^ioc^^ tt nuide in this country 
lUsUilaliun of woud (ehicfly tlic bnuiches of trees). The 
which cwmiM over i*oiuists uf n mixture uf pyroligiieoDi 
ill uclic iicid, cmpyreuniatic oil, &c. The litjuid products 
^UT separuied from tlie solid, and being ttaturated wilh lime the 
H-hoIe is subjected to dislillation. Tlic lirst jiroduct obtained 
'» tlw pjmliffneoui B|)irit. The pyrulignate or acetate of lime 
Imnetl b deootnpoeed by sulpliate of sudu by double ilecomptH 
itioOt ac«tau> of amIu and sulphate of lime being formed. The 
l]uid ruiifoining the acetate of soda is ei-nporulcd to drjneiss, 
the dry residue exposed to a heat of about 5^0", which 
the impurities mixed witli tlic ftnlt. It Is tlieii diawlred 
water, filtered, e%-a)H>mted to dr)-iiFC», and mixed with 
requisite quanliiy of Bul)iliuric acid to tuituratc the »oda. 
be mixture being Mibjectrd to distillation, the acetic acid 
les over pure, and its strengtli depends upon the quantity of 
tter which the salt containe«l when mixed with the sulphurie 
Vinegar ia a liqitMi of a rcd<li»li or yellowish colour, a pleasant 
•uur tanto, and an agrcouble odour. Its B])ecific gravity rurica 
fran 1'01:)5 to l-0'J51,and it differs also in its oilier properties 
ling to ihe liquid from which it liait been procured. It ia 
uibject to deo(Hnpo«itioii ; but Scheele dL*covcred, tliat if 
, be made to boil for a few ntoment«, it may be kept nftcr- 
fwardu for a long limc without alteration. Besides acetic acid 
and wal«r« viuc^ar contains sevend other ingreilients, such as 
■naoh^, a colouring matter, and often sbio two or more vege- 
I tobto acids. When distilled at a temperature not exceeding 
^^^Hif boiling water, tillal>nul two-thitiLsorfivc^xthiiat most, 
^^^Vhavr puAed over, nuwt of llicse impurities are left behind, 
^Bind ihe product is pure acid, diluted witli n'ater. The redduum 
~ k sliU an add liquid, and ol^en lets fall cry&tids of tartar. Ilut 

flMnwtioiHfar mo.rol.v.p. iOOt. The niethmla hi pmrnt prnrtitcil in 

Ee irc ikacribcd tn ibe Sd volume of the Elcitit^iiH de Ciiyiuic, |»il>- 
b; the O^n Acixlcnif . p. 6- Mmi; kIiU follow [lie proccM described 
Itxl 1 iMh«r* H dUkrtat one. 

a*. 11 










even when tliu.'< iliKtilk-il it is not quite pure. Mr. Chcncvix 
bas sliovt'ii thut it still contains a ppculiitr miicila^notia or 
extractive matter, aiid traces of a spirituons liquor. 

Mr. Pliil[i)M infoniLs n» that wlieii tlie best English malt 
nncfjur of thi- spt-ci fie gravity l-0*i04 is ilixtilleii, llie first eif^hlb 
i« of the specific gravity 0-997 12,* and a fluid ounce of it (.1-8047 
cubit; inches) (ILviotves from 4-.j to 5 grjiins of pred|>itiit<'<l oir- 
boiviite of lime. The next ».ix-eijfhths !mvo the specific tfravily 
1-00*23, and u fluid ounce d!»n(ilve» t^ 12 ((rains of precipitated 
csrbonate of lime. A fluid ounce of acid of the specific gia\ity 
1-007 dissolve; from 15 to 16 grains of precipitated carbonate 
of lime, or lil 8 grains of marhle.f 

2. The acid thus obtained is a liquid as transparent and 
OolourlcM iis u-ater, of a Mtroni^ iicid (iiKte »iid »ii agreeable 
odour, soincwbiii diflV-rent from that of vinefpir. In lliia state 
it is usiiRlIy cnlled acetous acid or distUitft vinegar. 

it may be preserved witliout alteration in close vessels. 

When exposed to a moderate heat, it evaporates completely* 
and without undergoing any change iik its properdes. When 
CX|Kiseil (o the action of cold part of it congeids. 'lite (nweii 
portion, which consists almost entirely of water, may be eauly 
eepEirntcil ; and by this method tlie acid may be obtained in a 
high degree of concentnition. The more concentrated tlie acid 
is, the greater is tlic cold necessary to produce congelation, 
Mr. Lowit/. liasitscertsincd that the acid itself how much soever 
it be concentrated, ery^tulli^es or congeals at the temperature 
of— 22'. 

0. Iladicat nint^r or aeetic acid, ai it li now called, wan 
originally obtained by distilling tY-nfii/ri* or atettUe ^f' copper 
in n retort, and then reclifying the liquid that comes over by a 
BCi-ond distillation. This process was known to the alchymivts; 
and the liquid obtained was distinguii^lied by the name of radi- 
cal vinegar. liertbollet, in 1766, endeavoured to idiou- that it 
differetl essentially from diitlilled vinegar or acrlrnis arid (as it 
was then called), «nH he wns of opinion tluit it contained a 
pri'ater quaniity of o.xygen. M. Adet in 17H7 publi«he<) a si't 
of ex{KTiment», from which he concluded that there n-us no 
otlier diflerence except concentration between acetousandatctw 
acid or radical vinegar.} 

•It muti have Kniininnl n portion of alcolial mixed with it, for tbc(p> 
gr. ot Hetic acid ia grmicr (hnn thni of nalvr, 
t Phillip* on [he I'hnrmnropwia Londincnsls, |>.T. 
X Ann. de Uiiin. xxitii. S'Ji). 



TU* oonclu^on wna coiisidcrad us hasty, as hf did not ntu-mpt 
lo nccount for the very striking lUfFerenoe in tlie taste and Htncll . 
of these acids xi lie hud neither repeated nor refilled the expe-. 
riments of ItertiioUet, on which the opinion of tlte difference 
betweeu tlienc tw<> acida was founded. 'Die conclusion of A<let 
•w o)i])osed, in 1798, !>)' Chuptal, who putilUhedaseicifex|ie> 
rimcHtM on ihc mmn nuhject." T!ii'« pliiloM»phcr cndwivwured 
to drinon«lntt<>, as IlcrllKilIrt iiitd iltme before hint, t]i»t acetic 
tnd acetous acids, even when of the siune Htrcii^th, possess dif- 
ferent properties, and have different efltact'* on otlier bodies. 
Vnaa tlu* etTeet of sulphuric add iiiioii i-ucli, and from the quuti- 
tily of charctKil which reuiaiiiH in the n-torl whi-n equal quua- 
lilii!» of each witiirated witli putnxh un^ (lislilUvl, he eoiiclitdcd 
tliat acetous ucid contiuDS a smuUcr proportion of carlmn than 
■eetic acid. And this he oonsklered as tlie cause of the difTcF- 
cacc in tlietr pro]>ertieg. 

In l**no, a new wt of experiment!* on the same subject was 
piihli»hcd by Mr. Dabit of Nantes.-f- This chemist endeavoured 
loprore thai acetic acid eonbuns a ^eater proportion of oxygen 
than iiretoa<4. When he dislilled a mixture of acetate of potash 
■ul)diuric aciti, the prixlncr wn.s aeelic aci<l : but when he 
tuied muriiiticacid fur Nulphiiric, be oliliiiiit-il acetous acid: 
liU wben to (his lii*x mixture u Utile black uxidc of nuuig^aneRe 
■ddt^l, I"' »MMni! us tluit be obt<-uned acetic ucid. And in 
oooe of the»c cases was there any carbonic acid emitted till ■ 
towutfa the end of the <listiIlalion. 

Tbo experiments of I>amic(| iit hL^t linnlly settled (bis dispute 
by deninnstratin^ that acetous and acetic acids differ merely in 
concentration. Tliis able chemist repealed the experiments of 
Adet, which he found perfectly accurate, and ]ierfurnii-d Si^veral 
new ones: all of which left no doubt tliat aeclons and acetic 
adda contain precisely the ssune pniporliiiu of o.\yf;en. He 
n«l tried the opinion of Cluiptiil rwjieciing the proportion of 
cuboii In each. \\'Iien equal qiiantiries of acetic and acetous 
■cUi are oomliini-il with potash or soda, the dry salts distillled 
leave tlie Ninie quantity of charcoal, anil yield the sanie qiuui- 
tity of otlier products. When reduced to the same specific 
grarii]-, the two acids form precisely the siime salts with all 
alkaliae and earthy buMi*^ Finally, ncetou^ acid ^ulually 
beoomes acetic acid when distilled repeatedly off dry muriiit£ 
of lime : and In lhi« casu no gaseous body whatever is evolved. 


• Ann. ik. Chin, xxvil I IS. 

-j- ll)icl. sxiviii. 60. 






From thrsr fflcbi, it is imptHsiblv to entertiui) a <loiil>t Oiat 
~ llic two Kubstanoea are rsaentially the ramr, iind tliat tlnit*- 
npparciiC differences are owin^ to (be great quantity of water 
wit)) wliieli ucHouit iicid ixdiliitecl, aixl the ntucila^iious matter 
wliic'Ii it Hiill rctitiii^* Tlie same rettiiltH were olilaioecl abo l>y 
l*roiwt, wlio bud drawn tlic same ooiicluoions before lie became 
Ac^iiaittU-d with Dumirq's poper.f In conwqucnce of tltese 
Utcbi, till* tenn acHuNg acid bua been laid u»ide, and the luune 
aeetie acid b now given by chemiitts to pure vinegar in all its 
states of concentration. 

Act-tic aeid in iii!i greaK'sl degrw "^ conceiilration may he 
oi>titint!d by mixing iiiihydrou^ acetate of lcad,«r ac<'Uitc of HOiia, 
with the quantity of concentrated sulphuric acid rcquisit« to 
*at»talc tlic brt-se* of thcMC wdtx, nnd diMtilliti)^ with a gentle 
heat The liquid thft^ comex over r* not quite free from sul- 
phurous acid. The mUlition of ii litlU? peroxide of lead tlirows 
down tlie Kul|>hurou# livid by instantly converting it Into sul- 
phuric acid. To be sure tluit it conlain<i no oxide of lead m 
solution, it n necessary to subject the acid to a new distillation. 
"' Acetic acid obtnincd by this proceiu is a compound of one 
atom of ncetic acid and one atom of water. It cryHtallizea at 
the temperutun* of 45" when we throw into it any particle of 
solid nuittcr (a crystal of itcvtic acid answers best), and the 
thermometer plunged into it riAcfl at the same time from 45° 
to 51*. These crystals are usually flat jihiies. and tliey have a 
jiearly lastre. The smell uf the aett) in tlin stale in m> Atrong 
as to bo painful to the olEnctory organs. Its taxtc is excessively 
AAur, and when ujtpliod to the skin it blisters the place aiiH pro- 
duces n sore. These cr)-stals melt into n liquid at a tempera- 
ture rather below 60°, though I hare not been able to deter- 
mine tlie exact point, Tbe specific gravity of the liquid crj'stals 
at 60', is )-0629fi. 'Hie following titble exhibits the specific 
gravity of these cry«tids in solution, and combined with various 
quantities of wut«r. 

1 atom . , I-0G296 

2 . . l-070(iO 

5 . . 1-070B4 
4 . . 1-07193 
fl . ' . 1-06820 

6 . . 106708 

I atom -f 






* Dsrrarq, Ana. dc CJiini. xti. S6i. f Jow. de. Phy«. hi >I0. 




I i\U>m + 7 atoms 


1+8 . . 1-03974 

1 -f. 9 . . I-05?04 

1 +10 10.J439 

tbu table it upt>ears that Uio ftj)edfii' gnnty i« a raui- 
■Diun, wlien llie liquid in a cumpoiiml of I uLum scid ami 4 utoms 
Wll4>r, or of 100 jMirts add and 7'2 jiarta water. \^'o sec also 
diat thr Bpccilic gravit}- of acid coataiiunf^ only- one atom water 
{« ntrwljr tKo same vitli tliat coiitaiuinf^ 7 atoms water.* It in 
irv!i)<:nt 5roin tbis that no iiiformatiun roHpcotiiiK die strengtli of 
tW ncid call be obuiiiieit from its s])ccific t^riivity. 

Acetic add {>o«»e««ea but little encr^ in cMnbiniii^ widi 
boses ; as incMl of tlw otiivr acid^ are capable of <li»j>t;H:in^ it. 
But it uciitr^liM-H mont buf»e« very well, and farmti witli them a 
cbiM of Mdiscolieil anfairs, scveiid of whicb are of considerable 
lin|)ortanei.-. They are all nntbout excei>iioH soluble in water, 
Tbv least soluble are the acetates of mercury anil itilver, but 
tbejr Me not sufficiently so to enable us to employ tb«-in as 
BMSits of detemuniiig the quantity of acetic acid in uiiy cum- 

Acetic acid retpiires a tlronj; red heat for its decom post lion. 
Mr. Chuni-vix iNimcd it five timo Miicetfyivt-ly lliri>u){ti a red 
bot porcelain tube without destroying it completely. But when 
tube b filled willi charcoal, the decom|>Dsition ia complete. 
'Tbe fin>l attempt to iiM^ertain the confttituentA of aceticacid cumpuiuaa. 
was made by Dr. Hi^iiit. He disttlled acetate of pota&li, and 
hj tiuU meu» decomiMMcd the acetic acid. The pro<liicts were 
eoDected und cxatniiie<i.f But at tbat time chcmi<itry was not 
fiu- enough adt-anccd to entitle ua to look for correct resulu from 
Micb an analysts. The subject was resumed, firi^t by Oay- 
Lomcaiid 'Ilienard, and afterwards by Kcrzeliui^. The former 

I burnt a mixture of acetate of liaryli-n mid cidontte of potiwh, 
'I'be acid was completely converleil into witter iinil (iirbonic 
ftcsd. Tlie KWH-oua prodiid8 bein|r examined, luul tlie quantity 
afieUie acid ducomiMwed known, tliey were enabled tocitlculale 
Itl 0anBtttuenta4 Beneliits' analysis was conducted according 
to tbc Mune tbeoretical principles. But ho was at more paing 
' Wflbtaiti tliv salt upon wbtdi he operated quite free from water.^ 




■ First Priadplci, £■ }3S, f Higgine on Accious Aci<l, p. 20. 

I 8« <h arc h cs Phjvoxbymtfiues. ii. 300. 

j Sm a afaiMe kcoiubi of lh« precautions whirli he tuok, nnd the inoJo 
wUth t« faUowsd, ia iJie Annals of PhiloM{>l>}, iv. 383. 


"'^'- The followiag table exhibits the composition of acetic add 
according to these chemists : 

HydngcD. Cuboi. Oijgen. 

Gay-Lussac . 5-629 + 50-224 + 44-147 =: 100 acid 
BerzeliuB . 6-35 + 46-83 + 46-82 =100 add 

But Berzelius has corrected these first results, and now con- 
siders the constituents of acetic acid to be 

Oxygen . . 46-642 

Carbon . . 47-536 

Hydrogen . . 5*823 

Now these numbers are meant to be the equivalents for 

3 atoms oxygen . . 3*0 

4 atoms carbon , . 3*0 

8 atoms hydrt^en . . 0*375 


i^ This would; make the atomic weight 6*876. I hare given 
an account elsewhere of a careful set of experiments which I 
made to determine the atomic weight of acetic add.* I 
obtfuned as the result 6*25. This diiFere from the analysis of 
Berzelius by an atom of hydrogen — a quantity so small that it 
is not easy to devise experiments of a nature capable of decid- 
ing the point with absolute certainty. But my experiments 
being simple and easy, I am induced to put some confidence in 
them. I therefore consider the constituents of this add to be 
8 atoms oxygen . . 3 

4 atoms carbon . . 3 

2 atoms hydrogen . . 0*25 


Several other determinations have been published ; but none of 
them seem to have been founded on direct experiment except 
those of Gay-Lussac, Berzelius, and my own. 

Acetic acid is formed in great abundance during the slow 
combustion of alcohol, ether, and volatile oils, by means of a 
coil of platinum wire, by the method discovered by Sir H. 
Davy. Mr. Daniel considered the acid formed by this process 
as peculiar, and he described it under the name of Itanpicaxid. 
I stated in the last edition of this work my opinion that it was 

• Anoals of Philoaophy (2d seriee), ii 142, and Firet PrmdplM, iL 1S7. 



merely ncciic acid, (liNf^uiiied by llie presence of some foreign 
nUtcr. A nd ibe accunuy of tliix ojtiiiioii uil^ kooii afteru'iinb 
(■IllklUhed l»y Mr. Duiiicl htmsclf. Tlicrc is u curious wt of 
rxprrimcnts by Mr. Miiler, showing thai a great vnricly of 
•ulKrniices afwr being h«ated, wlien bnmglit in contact witJi 
the rapour of ether, maintain a slow coiubuHtion, and give origin 
to the formation of a greal deal of acetic Hcid.* The flubject 
b highly worthy of a )>arttciilar invc^ivatioii. 

There ar* tl>ree acid* which hare hc*'ii dlstingui^hett by [locii- 
liar nome-i, but which seem to be notliiiig el^ thun uc-etic acid, 
a little diflpiiwd by the presence of foreign matter. It will 
be worth wliile to give a sliort account of these acida in this 


H 1. Lactic Acid. 

^L— Sjftpo milk is kept for some lime it turns eour ; Schcelc 
^HMBned the aci«t tliu» evolviil, ami gave it tliv name of iftciic 
«ad. He din'cia the foUovring method of procuring it : 

Evaporate- a qnantity of sour whey to an eighth part, ai]d ,^V*J*- 
Ithrn filler it: thit separates the cheesy parU SaturMt« the 
rCtpitd with lime-water, iuh) tlie phoHphate of lime precipitates. 
I Fitter again, and dilute tlie liquid with ihrts* times its own bulk 
' water ; then let fall into it oxalteacid, drop by drop, to pre- 
[ctpitatc the lime which it has dissolved tVom the lime-UTiter ; 
fthen add a vt-ry Mnalt (piaatity of lime-water, to see whether 
|loo much oxalic acid has Wen added. If iliere lias, oxalate of 
immediately preeijittntes. Kfiiporaie the KobiUon to tite 
rcotuuMencc of honey, pour in a sufficient quantity of uU'dlioI, 
and filter again ; the acid passes through dissolved in the alco- 
^^ hoi, I>Ht the sugar of milk and every other subslaiice remains 
^1 U'hiiid. Add to tlie scihitioii a xiiiall <juiiii(ity ut' water, and 
^■lUstil with a amall heat; tlie alcohol pa««cs over and lonvea 
^Uwhitul tite lactic add dissolved in water.f 
^P From tlie properties of the acid procured hy this process, 
Sehci-le coiiclu<lcd that it was very analogous to ihc acetic, but 
.that it wanted something to bring it to that slate. He even 
ittfd out a method of procuring vinegar from milk in con- 
jerablc qaantii)-, and ascertained that it always yielded a little 
eu di&tilled.t 
lo the year 1802, Koidllon Lagrange published a set of 

• Aao^ of PhilcMoptif (ed Mrim), ui. 1 7. 

t Scbtwle, KoDgL Vet. AtuiL Huidl. 17W, p. 1 16. | Schoole, IJ. M. 



aqpnQMntit on )nctic iu:\A, from which he drew im a conclusion 
tkat It Is nteroly acetic ncid contuniinatf d with some Kiliiir niiil 
nimal matter.* 'rhenanl drtw tlic wune ixi»Lliu>iun tram his 
experiments in liM((.f Both of these clu'mist* had obtained 
the ncid wliivh tliey examined by distillatioii. Hut Scheple 
had expressly stated, tliat lactic acid when distilled u-ai* txHi- 
verted into acetic add. TJie existence of lactic acid, there- 
fore, was by no means disproved liy their experimente. 1'lic 
mil^ect was taken wp by Frofewwr Ileneliiift, in 1B08, In the 
Moond volume of his .\nimal Chemi.*try, he examined llie pro- 
perUes of lactic ucid in dctidl, and endeavoured to cstublUh its 
peculiar nature.) He employed tlie following process for pro* 
curing pure lactic acid : 

i-jttmcl obtained by cvaponttiiig whey to drynesa, consista 
of hicdc acid, hictitle of pota»h, muriate of potash, phosphate of 
lime, HJul »H>nu' animal matter. It wiw dtswlvi-d in alcohol and 
' mixetl with alcohol, liuMing -'^th of its weight of coiicenlniied 
sulphurie actd till there was an excess of stdphuric acid in tliv 
aolution. Some sulpliate of potaab was precipitated. To i;ct 
rid of the other acids it wan dij^'.-ited over carbonate of lead, till 
the liqnid acquired u sweetish tiule. By this the itiilphuric acid, 
the phosphoric acid, and most of the muriatic acid, were separ- 
I ated ; but lactic add forming a soluble comiwiuid with lead 
' Vemained in sotutiun. A current of sulphuretted hydru^cn gas 
being passed through the liquid threw dow n the lead. The 
liquid was now digested over quicklime till all the animal matter | 
waa s«|iarated. It now contained only lactic acid, muriatic 
acid, and lime. A portion of it was taken and freed from ita 
lime by means of oxalic ucid. This portion was then sautrated 
iritb carbonate of silver. By moans of this solution the remain- 
der of the liquid was freed from muriatic acid. Finally, the 
lime was thrown don-n by means of oxalic acid, so that nothing 
remained but lactic acid dissolved in water. To get rid of a ■ 
•malt portion of oxalate of lime which it may hold in K>lution, f 
it w proper to evaporate it to dryness aixl rediwwlve it tn wutvr. 
W'heii uatDical, rioe, and several otlier vegetable bodies, arc 
mixed witli water, and left, to spontaoeous fermentation, they 
acquire an acid taste and smelL The acid thus formed was 
examined by Uracoimol, who con^idoreii it iw « new arid, and 


• Aan. da CMoi. L 88a f Ibid. lU. EM. 

t KraUnungar i lyjurkcnii^n, ii. 43IX A iraoilBtJon of hb aecouM of , 
lactic acid b pubUthod in ibc Phil. Mt^. xll H\. 



ipn It Uic niime of tuaceic add.* But Vogvl aftenranU 
■1m«'«1 it U> Ih? identical willi th« lactic acid of ^clioele.f 
Lactic acid vliea obtaliHil Ity Itracoiiiiot's procewt (which tiuncun. 
■Utn til Haturatin); t3ie arid villi oxi<lc <>f xinc, und purifyiiifr 
he mU tiy II doiihtc crj'stjilliziitiori. Tbt- silt is oovr dbsolvH 
I hot water, the oxide of zinc thrown donm by barytes water, 
1 the barytea by ttulphuric acid) is colourleHs. Dot when the 
of Scbeele or HcrzeliiL^ in adopted it )ia.t a lirownixh 
■Dow oolonr, and u sluirp sour taste, wliicti is miieli wi-itkeiiod 
[by diluting tlio arid witli water. M'liik' eold it luut no Hmcll, 
nut when lie-ati'd it acquires a sharp sour odour, not unlike that 
Tof nihlimed oxalic acid. It does nut er) stall i^ce, but wlii^n cva- 
[pontnl to dryucK^ form.i a smootli vartiiidi which gnidiudly 
IsttiBett BKi!i(ure from the air. It dlsiolvea readily in aleohoL 
tWlwo bofttfid it boils, emits a sour smell, and leavca a bulky 
not nsily liiunt. When tlistilled it gives out empy- 
itic oil. water, acetic aHd, carbonic acid, and inflammable 

All the niw which it form* with bibiM arc soluble in 

prater, and hardly any of them can be made to assume a cr)'s- 
^latUxcd fonn. 

Tlili acid obviously difTem from acetic actd in being Icsa 
roblile. But M'hellier thw ililTcreiice be not owing to some 
ifoniga HubKtiuin^ combinnl with acetic acid Ims not been dcCer- 
I vui<>d. 'Ilie lactates described by BerzeUus as exUiing in all 
fluids, have not boen suificicntly examtne<I to make thi'ir 


3. Catetc Acid, 

lliU la a name ^ven to a substance formed by Proust, by no* Miin. 

tubjpctlng tlti; rnrd of milk to tlie putrefactive fermentation, 

4111I wliicii lie considered as a peculiar acid. Curd was allowed 

putrefy under water at a temperutiire of abutil bO". In about 

lya' time tlic water will be fotnid to lioM in Hohition plitw- 

', acetate, and ca»c«ie of ammonia. The water is renewed 

'from time to time till the putrefying curd given out no more of 

time sulwtances, Tlie watery liipiids urc ev«pon>ti'd to the 

consiiitenec of a syrup, which is mixed with alcohol, and the 

mixture left for Mime time undisturbed, and the whole is tlien 

Ihruwn on iIk> Alter. A wliiu- i.ubstance remaias on tlie filter, 

to which Proust gave tlic name of ritMif aritfe. The alcoliottc 

liquid contains tlie caseate of ammonia. It is subjected toili»- 

Aan. da Olai. txuii. 86. 

t AaDBliofPhiloHithy.iui.SOl. 




tfUntton to get rk) of die alcohol. Tlie residue is boiled with 
witUT tind rarbonate of lead, which dit>eng;agt's ull itif ammonia. 
The lifjuid being nowfiltcn'd Ucxposed lotheaclioiiofacurrent 
of flulphiirvtUtl hydrogen gns to throw down tlie l«id. It is 
Oj^uin filtered and coiicciitratcd to drivt- otTttii^ acetic acid which 
it contains. 'Flie liquid thus treated cotwstw, acconlinfr to 
Proust, of a solution of cawic acid in water.* 

This aci<l w described at a light yellow syrup, which when 
heated, passes iuio a horny, tranaluceot, yellow matter, luiring 
a sour, hiller, and choesy taste, and easily soluble in water. 
According to Braconnot, who luw repeated the e.\perimentjs of 
Proust, tliis suttstanee owes its add properties to a quantily of 
aeetic acid which it eontains. IJul it cohmsIs chiefly of vniioua 
unimal muttetv. One of the most n^markable of which (the 
aueie axitk of Proust) he has called apotefitrlitK It U mixed 
with some resiit. some oil, and acetate of polasli, inurtate of 
potash, and acetate of ummonia.f 

It would appear from thiit that caseie acid ts not a peeultur 
acid, but merely the acetic disfruised by a quantity of foreign 
matter, which retards Its volatility. In this respect it resembles 
I kctic acid. 

ti. Fibric Acid, 

I give this provisional n.iine to an aeid substance obtained 
by M. Perelti by tlie following proccm : The muscular flesh 
of an animal w dig(^su-d in euld water, luid the water evaporated 
to the consistence of a synip. This matter is d^«st«d in strong 
alcohol, aiul the Miliition being set aside for some days in a close 
vessel, some small needle^iaped crp<taU make their ap[iea> 
ance. These needles red<lcn litniui) paper, and wlien heated 
give out oil luKlairbonuteofanimoni;!, with a Mnell of roast meat. 
They dissolve easily in trater and alcohol, and may be mi.\ed 
with sulphates and nitrates ivitliout undergoing decompoHitiou-t 

These fuctit are scarcely nuflieient to determine the real lutturc 
of these cry^titU. Tbey consist prolwbly of on alkaline super- 



tMncy. This acid is first mentioned in the Philosophical Tran-^actioiu 

for 1671, in u paper by Mr. Kjiy, giving an account of tli«! 

* Ann. de Chin, ct dc Phjt. x. ta. 
X Jour. lie Phum. xii. S7-k 

\ Ibid, xnvi 165. 


of Mr. tialse, ui<l llie experiments of Mr. FiiAer, 
the ari«) juice wliicli U «pontancot»ly given out by untt, unci 
bick Oiry yifU! when distilli-d.* Mr. Ftiher compares tli» 
wiih vinc^jr, but [wiiibf out some difiVTentes between 
Scarorly any uddidon was mude to tlivso facts till 
' ptibtishcd a disserlation on the subject lu tUo Herlin 
lemoirB for 1 749, in wfaicb lie describes tUo method of olilain- 
tlic formic acid from tbe Jitrmiia rufii, or red aut, aiid 
out iu* iiroi>ertifs witli his iiMial precision iuid raelbod-f 
new dtncrtHtioii uns published oil die nunc subject by 
tmn. Arvid«on nnd Ocbni in 17l^, in wliich the discoveries 
' lib^nff were conlimied, and many new porticolara added. 
Itimbirtadl's paper on the same subject appeared In CreH'e 
ntuU for 1784. lUs researches were directed chiefly to the 
«tion of (be formic acid. I le di^inoailratcd that the juice 
Tants coDlainctl cvvcial f»n-i^i l)oiiit--s and amotig otlien*, that 
tporttoii oi malic oaW might bede(eete<l in it. Kicbter pub- 
hcd experiment;) on fonnic acid about the year 1798, ]>oint- 
Difout a method of procuring it in o very concentrated statc.J 
(-}cux soon after examined It, and found it analogous to the 
Ftic tin^$ This opinion of the French chembt was con- 
firaed in 11^2, by Fourcroy and Vnnquetin. who published a 
diMprtatioii on ants, and concludiil from tlicir cxperimenK that 
formic acid is nothing else than a mi^rturt of the ucetic and 
ie aei«ls.n The o]iimon muinlnincd by these celebrated 
pbers induced Suersen to ctaniine tlie subject by expe- 
iL Tilts chemist, in an elaborate dissertition on fonnic 
published in 1805,^ shows that mast of llie facts pointed 
A by Fourcroy and \ auquelin luid Iwen alreu<ly usccrtjiined 
preceding chcmiAt*; tluit the experiments which tbey detiiil 
pre not sufficient to warnint their couclusions; that formic 
J, when properly prepared, contains no malic acid ; and tlmt 
. pooattses prtipertirs different from the acetic. Gehlen niis 
ioeed to resume the cxamiuation of tliis acid, by m>me obser- 
utloiis which I made upon it in a former edition of tliis work, 
publiidied an elalMintie dissertation on it in I SI '2, in which 
rlc compnrc* tlie pTO)K-riie« of fonnic acid with those of ucetic 
acid, and points out the peculiar characlers of formic acid with 

• PfaiL Trani. t. 9003. f HwgmS't Opuic. L SSI. f Gcbleo, iv. 7. 
{ FourfTojr, X. 49) | Eng. Tnuu. I have nol mco riUwr iJie dincrtation 
of KicKiv or Oarcnx. 
I FhU. lli«. IV. 1 16. 1 a«lil«n-» Jour. iv. I. . 




I Bmr •KUUl. 

great cleaBM'kiul precision.* Since tliat time it hus been 
annlyxv<I by Itcrzeliiis, and an artificial metJiod of preparing il 
has been discovered by Doljereiiier. 

Tlie simplest metliod of pnicuriiifr foniiic acid in a state of 
purity is tliat of Marifniff as corrcctcii by ItichtPr. Suencn 
accordingly liuil recourse to it. Tbis inetliotl in as follows : 
Infuse nny quantity of ants iii about thrice their wrt|;lit of wateTi 
put the mixture iuto a silver or tinned copper still, and draw off 
llie water by di-itiliatioti as long as it continues to come over 
without any burnt Mmell ; for tiu^ db.till:itiuii must be stop]>ed as 
»oon -M timt smell begin* to be pt-recived. Saturate the water 
in tlie receiver with carbonan- of pobudi, aiid evaporate to dry- 
aeu. Mix the white mass thus obliiincd witli iis much sulphuric 
acid, previ >iivlv ililuted with its weight of water, as is sufficient 
tosatunui il" [ it;i.'Ui. hitroduee the mixture into arelort, aixi 
diitil slowly to drynvsK. I'hc l!(pii<I which ciime« over into the 
receiver is to be iigatn rectified by n very moderate he^it, toget 
rid of uiiy portion of sulphuric acid tJiat may bo prescnL 

Gcblen, to be still more certain of tlie purity of his formic 
acid, »<ttturaled tlie acMi prepared by the above process with car- 
bonate of copper, and by tlic reijuisite evaporation, se)Minited 
the formate of copper in crystals. He mixeil in n retort 13 
ounces of these crystals with B ounces 010 grains of sulphuric 
add of the upecific gravity I-A64 and distilled. He obtained 
6 ounces 4 10 ^liiut of formic acid in a sLite of purity. 

Doberciner dUcovered tli;tt if we mix togetlier in a large 
retort one part of crystaU of Uirtjiric acid, 2} parts of deuu>xidc 
of mangniiesc, and 'JJ of sulphuric ueid of the specific gravity 
raS, previously diluted wiib tn-ice itx weight of «-ater, and 
apply beAt,muchcarl>outcacidg»<i»disei^aged, and tlie matter 
in tlic retort swells up and has a great tendency to niu over. 
After the disengagement of gas is at an ond, ifwe distil over the 
liquid wo obtain dilute formic acid, which may he concentraled 
by saturating it wilJi potash or so<la,and mixing tite formate with 
the requisite quantity of Rulpburic acid and dlttilling.f 

W'oliler liii« found that the proceio sticoeedM equally if we 
Bubstilutc starch for tartaric acid. And Lieheg even iiflinnB 
that many other organic bodies mjiy be substituted for tartaric 
acid without injuring the process. 

It lias a shaq) eour taste and cannot be crystallized, eren by 


' Scbwd^i's Journal, iv. I. f Uitbert'n AnnulcD, Uxi- 107, 

ronuic ACID. 

itioD of artifidul cold. Its «|>ccific gravitj- ut tb« "^t- 
iMDpcmturc of 6ft» is M 168,' while lliot of the most concen- °^ "' 
tnted acetic acitl doe; not exceed 1*08, and it contains 1£H66 
fnemu of water. When mixed with it^ nwn woiglit of piira 
er iu spreific gravity bcoooic« 1*06. And if wc- add twice 
mnel) wmur it becomes 1-0296. 

Dubrmner liu ascvrtmned that when mixed with nnhydroua 
pburic iiL'id it uiidcri^ocs dcconifweition, because it cannot 
ahnu witliout wnter or a base. It u converted into carbtniic <'«<ii<«iu«ti, , 
tide gas aiid water. From tlie proportion of airbonic oxide 
l{ai evolred, he conclude*] that it coiwists of 
3 atoms oxy^n . . H 
2 aXotm carbon . . 1-5 

1 uota hydrogen . . 0-125 

that it differs from oxalic acid ttimply by containing an atom 
bydrogen, white oxalic .icid contains only •') atoms of oxygvn 
biBM of carbon. 
lis eorrctfpondti very well witli the aimlysis of Bcrzeliu^t 
rho found its constituents 

Hydrogen . . 2-84 

Cubon . . . .12*40 
Oxygen . . . 64-76 


'or thin is equivalent to 

1-Od iitom hydrogen 
2-0OI atoms carbon 
3 atoms oxygen 
.1 ciunciding witli tlic thvoreticai num)>crs. The analysb 
Ool>el agr««« also with tliis ver)- ncurly.^: There can- 
tbe least donlit thon, thut tin* ntomii* i-onstitiition uf thift 
as has been btalt-d, and that its atomic uf'ight It 4-62ri. 
Formic add has a considerable resemblunoc lo acetic; hut 
y differ in some particularst particularly when combined with 
Very dilute fonuic add is :«iid to undergo spontaneous 
Idrcompodition tike vinegar. Tint 1 have preserved for several 
willMut any alteration, formic itcid prcfuired by Dobe- 
ner's proocM, and in a rather dilute slate, tliotigh much 
onger tlian %-inegar. 

' Stkvrdggar's Jour. Iv. 14. | Annsis of Phitosophjr, ix. lOT- 

nrhnt^ri'i Jafatfcticb, ii. 344. 






Tb^re U a mineral of a lioncy-yvllow colour which is foi 
in snull solitary CTyxtaN amon^ the layora of vrood-coal at 
Arten in Tliiirin^. At first sight it ba^ somo rcscnili lance to 
atnber; but Werner recognised it im a peculiar sub*t«iic4-iil>out 
the year 1 700, and gave it the iianic of Ititmif stein (hont-y-rildiii*)) ■ 
which foreign mine rat uirLttN converted into mdlUe, Tliis min- ^ 
era! w very rare. Hitherto indeed it luvi hc'«ii found only in 
'i'huriiijiia and in Switzerland.* 

Mcllitc lias usually a honey-yellow colour, but sometimes a 
Htraw yellow. It is alwa)'a crystaliiaed in octahcdruiiM, hut they 
are rarely entire : sometimes indeed almost the whole <>f one of 
the pyramids is wanting. Their surface is generally ^nutotli and 
brilliunt, and interiorly they hare a glassy lustre. Tliey arofl 
semi transparent, brittle, soft, and oswily reduced to powder, 
Wlicn ]iaui)ded, they ns«uinc a ycUowislt-^ray colour. Their 
specific gravity is about I'oSO.f ^^ 

Mineralogists soon discovered tliat mellite is partly eom- 
hustible; but tliev did not agree about its component parts, 
I>ain]iadiust and Ahich^ undertook its chemical anal)'«is aboutfl 
the ifflnie time. ™ 

But the rejiullit of llieir aiialy^eH dttfcrcd so much from each 
other, that little confiilciice coulil )h- phiceil in eitlier. Besiiles, 
it wax evident from the way in wliich their experiments were 
conducted, tlial tlie original component parts of mellit« luid liecii 
altered by fire. Klaproth analyzetl itin 179!), andiiKcertiitniNl 
it to he a compound of alumina and a peculiar acid, to wbicli he 
gave the name of mettitic.\\ And tliiH iinidjstH was soon after 
confirm<.sl by Mr. Vaut^uelin.^ In the year IWJiJ M. Wiihieu 
8ubj<^^-l<-<l tim acid to a new examination, and lias lulded scven^l 
interesting facts to those whidi had been previously deter- 
mined.' • 

Hitherto mellitie acid liufl been found only in tlie inellilc. It 
may be procured from that minend by the following procnis: 
reduce tJie im-llite to powder, and boil it in about 72 liiiHrii its 
weight of n*atcr. The acid camhines witli die water, and tins 
alumina separates in flakes. liy filtering the solution, and 
evaporating sutEcieutly, tlic mcilitic acid ia obtnined in the 

• Brocliani's Mincnila(!7, ''■ '5- 
) C-it\l'% Aniiali, i;<l7, ij. ID. 
I 114. 
** Poggcndorf's Annnlcn, lii. 395, 

i KUprolh's Bcitrage^ Si. 1 15. 

{ Ibid. p. 1& 

^ Aim. de Chini, nxfi. SOS. 




Slate of crystaU. Thu wta KUpralh':* proccsR. Hut Wiihlcr 
on rependng it found thiit tlic ini-llit!c acid wns not fni' from 
almmna. He emplMynl tb<- follon-iii|; process for procuring tltis 
■dill ill » Htiiic- o( purity : McIHle reduced to a Ane powder WM 
d^cMrd ill n tMliilinn «f rarboimip of an)lnanii^ anci die liquid, 
■Arr it Imd taken up uU tJie meiliiic aci<l, vms lKiili>d till uU the 
rxocM of unmonia was driven olT. It «-im then filters] and 
enf>onit<Ml til) ihf mclUte of ainmimia was obcuinitl in cryAtalA. 
TV pure crystal* were dLwolved in wuter and prccipituU'<l by 
SMtato of lead. Tlie precipitate being edulcomtcd was mixed 
with water, tlirou^b u-Jiicb a nirrcnt of sulpbu retted liydrogcn 
pa wan pmBtfil u* ilirow down ibe leaiL 'I'be niellitic aci<l dis- 
mlres in the wat<.'r, and is obtained in a state of purity by 61- 

The liquid obtained in tliLt way being conccnlrat(*d to tlie 
(Oadslanoc of n synip iliil not crystallize, but by continuing tbc 
wiperadini tlie acid remained beliiml in tlie state of a white 
powder. Being dissolved in alcoliol and left to apontaneoits 
m, the melJittc acid cr\'stallizcd in very line needles 
ID the form of stars. 

Meiliiic add has a rery sour taste, in not altero<l by exposure i-roprMM 
to the air, is very soluble in water and aU-nliol, and bears a 
fttUy li'i^h (eiii]>t-rut(irv bttfurp it i« cluirred. When Nublimcd 
io a gloM tube u crystnlliiie fusible matter h obtaiued, wliicli 
fameme» pectiliar properties, and lias obta!ne<l tlie name of 
fynmuBitic acid, Durinj^ this gublimatiou no kiiu-II of cmpy- 
reutnuiie oil u observeit, as usually liappeti.'t when orgaiiio 
bodieo are «x[ioMd to u temperature sufficiently high to produce 

Sulpbimc aci<t, though in a concentrated slnte, produces no 
Iklteratiou ou luellitic acid. It ilLsMilvcs the acid by a boiling 
heat, but DO alteration is produced in it» colour, and tlie sul- 
pkuric add may be distilled olt leaving the uiellitic acid iinal- 

Nitric acid, own when aKMt»leil by heal, neither dissolves nor 
alien mi'llilic acid. In tlits re»pL-ct il bcitrs a striking rvsem- 
Uuee to u.ialie add. 

When a soiutiun of incilitic add in absolute alcohol is 
litiiled for some time, it would Hp])ear from the obscn'ations 
of Wiihler that the nature of the add is ijuite altered. W' lieu 
«va]>onU(Hl to the consistence of a syrup it bcomne* dark brown, 
and a sour lasti'd mailer remains resembling rc«in, and like it 
iiHolubte ill water, tJiough it communicatee a sour taste to that 



ciwp-i- liquid. Wltcn water is left upon this matter for mmv time 
white taateleas suhsUmce remains wliicli burns citsil)' «-lih flitmo 
like redn, leaving cliarooali but yielding no Bublimate. It is 
scarcely iwliible in b»t wattir, but very reiuUly soluble in aloo- 
boL Thi< soliiticin rpddcnH litmus pnpor. It dix»olveii also 
very rcfulily in liquid ammonia. 

From tlie analysis of mcllate of alumiiia by Wiihler, ita con- 
Ktittivnt* Appear lo be 

Mcllitic acid . . 41*4 
Alumina . • 14-5 

Wiit«r . . 44) 


Now till-* ia f cjuivalent to 

Molliiic aciil . . 6-424 
Alumina , . . '2-23 
Water . . . 6-84'2 

2-25 i« tlic u^i^lit of an atom of alumina, 6-1^2 is very near 
6* 75, the wfiglit of 6 atoms of n-atrr, therefore 6'624 raunt bo 
very nejirly the weight of an atom of mellitic acid. M'c may 
tlierefore take G-H as aflbrdiiig a near approximation to the true 
Atomic weight of tlti« ftcid. 

From the great permAnrnce of tliis aciil, and its resemblance 
in many particulars to oxalic ucid, it w highly prolnible that like 
that ncid it eonUiiiis no hydrogen, btit is a compound of carbon 
and oxvgen. Oxalic acid Ua compound of '2 atoms carbon and 
3 alomA oxygen. Is it not probfibk- tliat mellitic acid in a com- 

pOUIKl of 

2 atoms carbon . . l.A 
d atoms oxygen , . 5 



This can only be determined by an analysis of mellitic acU. 
Should It turn out to be free froni hydrogen, it will require 
kereafter to be placed among the acids with a simple base, and 
next to oxalic acid, lo which it lias so striking an analogy. 

'I'Lc salts which this acid forms witli bases have received llw 
Dame of meUata. 


Tartar, or cream of tartar, as it is commonly called, when pure, 
h&s occupied the attention of chemintH for lieveial centuries. 
Duhamel and Orow»e, an4i after them Margraifatid Roiielle the 


provfd ihM it wwi composed of an uHH iinit4>d ta cimi. 
pMuli : but S(-ho«lc vm» tbe Grat who obtainot tJit* acid in a ' 
Mfxtrati? state. He communicated his iiroectw for obtaininff il 
u> Ki^uius, wlio publi»licd il lu the Slockhotm TranMicdonH for 
1730. It coOflistMl ill boiling taitar witli chalk,anil in dccomgiofr 
tag tii« tartrate of lime thua fuiined l>y means of sulphuric acid. 

llir proctf*! empluyrd nt prc^nt for olititintnK tartaric ncid, FnfwtUM 
vUiJi U tlic «aine «'tth tlutt of Schcele, w the fullowin^ : d)t»- 
nlre tartar in Irailiog watOT, Bad add to tbc solulioii potrd^red 
thalk till all cfforrBscenec ccaMS, and tlic li<|uid doos not red- 
in regetable blues. Let tlic litguid cool, and then \>nsR it 
Aiwig^ a filter. A (|uantity of tartnitc of lime (whtdi is 
■I Inaoluble white powder) retiiaitut upon tbe filter. Put this 
knnUe, prtiviously well waHh<rd, into u ^biw cucurbite, tuid 
ftat o)i it II (gtuuility of sulphuric iictd equal to tlie weight of 
Ae cfcaJfc employed, which must be diluted with water. Allow 
il to difCeat for 12 hours, slirriag it occasioned ly. 'I'he hu1> 
|buric fuiid didplaces ike tartaric; nulpliate of lime rcnutirui at 
the boUom, wbile the tartaric acid i-i dissolved in the litjuiil 
part. IX-eant off thitt List, and try whether it contidns any 
nlpburie acid. Thii ia doue by <h-opping in a little aicvlate of 
UtAi a precipitattf appean, which \s insoluble in acetic acid if 
•olpluiric acid be prevent, but itoluble if it 1>c abseut. If sul- 
pliiuic add b« present* th« liquid must be dig:ealed a^in on 
Mna more tartrate of lime; if not, it in to be Nlnwly orapor- 
■Ud, and about ODC-diird pitrt of tbe weif^ht of the tarUir em- 
ployed is obtniB«d of cryMdlixed tartaric acid. 

liaM may be substituted for cludk in this prDc<-»«. In titnt 
ctae tbe tleoompoiiition of the tartar is complete ; whernw l>y 
tfehvelv'H metiiotl, the exoes.i of acid only cocnbines with the 
Qkaik; but when lime is iue<l. the wh<^e tartrate of lime by no 
lacMH ■eparalL>«. A eonsidemhle portion U retained in solutiofi 
by the potash of the tartar now duengaged. If the liquid be 
tv^Miratrd, this portionappean under tlie farm of a transparent 
jelly. By expoaure to tbo air tlic potash attracts carbonic acid, 
which unites to tbe lime, while tltc t^irlaric acid coinbinea again 
witli llie potash. To obtain tltc puiasli in a 8tal« of tolerable 
purity, the bcKt metliod, aceordiiig to VauqueUn, to whofo we 
are indabtetl for these ob(u>r%'ations, is to evaporate to drjtiesi, 
and heat tlie renidue to rediii>9i9. Dy lixinating the ma<is, the 
potoali will be obtaitiml tn a state of considerable puiity.* 

ITtis crystals of this aci<l are usually »o irregular tlutt it is 
* Ann- de Chiin- xKii- H7. 
11. V 



ililEcuIt lo rcrer tliem to aiiy rrgfular figure. M. Peclet con- 
siders tliem (uf MX-«i(lo<l {>rtKin«, four of llie iwlid angles or cdg» 
of wliidi arc of I'iSt" aiitl tlu- oilier two of 102°.* Mr. BroiAf 
considcni tlif primary form as un oliliquv rliombic pristn. The 
cootiguouB tu'o f&cc» of the prism arv inclined to each otiier at 
angles of 88° 30', aiid the base of the prism makn with riUier 
of the lateral faces aii angle of HI' lO'.f No cleavage has 
been perceived indicating the direction of the primary laces, 
'"iwi"' Crystal liJied (arlariir itci<l is while, and very finn, anil i« (nit 
imperfectly truiisparctit. It may be exposed to the nir for any 
Ict^b of time without undergoing any change. Wbcii heated 
a few degrees above iVi" it melu and ri-mnins limpid and 
irattfiparent lilte water. At '2ZW* it boih without losii^ itN 
tnm^paroucy or becoming coloured. If the boiling be continued 
for n »>hort time only it doea not lose above 4 per eenu of its 
weight. Oil cooling it concrete* iigaiii into u hard «emitnuis- 
parcnt mass, ver)* much n.-Keml)ling a quantity of white sugar 
that has been melted at llie >ume temperature. By tills process ^ 
the nature of the acid is chwi^'d. It now deliquesces wht 
exposed to the air. 

Boiling Wiiter cli.<solve» twice its weight of ilii^ add. Il 
soluble sJso in ulcohoL A dilute aqueous solution gmdiuiltj 
tuKle^;oes spontaneous solution, being cnver<-d with a miicouff ' 
coal; but I liave kept a concentrated solution for years with* 
out any change. Nitric acid converts tliis acid into oxaliej^l 
while concentniU-d sulphuric iicid converts it into acetic acid. 
^CooiiiMiuan, The crystals contain water as a constituent, but no water can 
be driven off by heat. However, when the acid U combined 
witli a base, espcctidly with oxide of lend, and tlie salt is healed, 
tlie water is driven off, and nothing remams but the anhydroufl 
acid united to the oxide of lead. In this way Beraelius dete 
lutuctl the composition of the crystals to be 

Anliydrous acid . . 88*15 
Water . . . . 11-85 




■ Aim. du Chitn. ct cic PhjH. xxii. TS, f Ann.of Phil. (icl«crie»X »i- ! 
% [)u cxfieriinenut rmulli w«re 

AdJ . . f)»i 

Wilier U-& 


Th« numbera In Ui« lut v/av derived from theorviic cansiilentlona. See 
Ann. lie Chim. Ixsxi. iO^ 


Sow, if we consuler the water m equtvnloiit to one atom, wc 
•fatain for tlie atomic weight of tartaric aei(l8'36S. For Il-f45is 
tBe»13iHi MS5 to i^-QG*^ Now, the result of the analysU (if 
tUi add by Bcnceliiw u a» follows : 

Otfboii 36-8(>60 or 4-07 atoms eat^n 

Oxygen 60-1895 or 5 atoms oxygen 
Hydrogen 3-0045 or I'OOG atoms hydrogen 




TUl comM vt-rj' n<-ar 4 utoms carbon, 5 atom* oxygen, and 2 
tfMM hydrugcii, which is the constitution of this acid according 
t» ike uialysH of Prout. Hence its atomic we^ht is 8-25. 
I Iwre shown in my '> First Principles" (p. 1 1')), by a set of 
aperimeiits which I consider as decisive, that the true atomic 
■vighl of tartaric acid is 6*25, and lliat it is a oompoinid of 

4 ntoms carbon , , 3 

6 utoni« oxygen . 5 

3 Atoms hydrogen . . 0-S5 


The comhtnaltoiu) i>f ihtM aci<l with liases bai'e received tlic 
HMBc nf larinUt*. Kike oxalic acid it him a tendency to unite 
la many bftoett in luo pnijiorlions. Tartaric acid i^ nomvtimos 
iMcd in medicine chii-fly in the iftate of «altit. But it« great 
■H Is by the oil ieo-prin tent, who thicken il with gum or rousted 
Ittn^ and apply tt to those parts of a piece of calico previously 
dyed red or blue as are tobe n-niicred colourless by means of e/ito- 
ridf of lime, or bleaching powder. 'I"ho tartaric acid combining 
with the line aets the clilonne at liberty, which immediately 
devtreys the colour of the part of the cloth on which the thickened 
add kiM been fixed. For thiH purpose chiefly it '» miinnfactnred 
ia litis ooantr)' in greiit abundtirice, and xoM at a very low price. 

Tartaric acid has a grejit teiulency to combine at once with 
IVM bases nnd fonn double talbt. In conHOfgucnn; of tins pro- 
perty ir ]>revents antimony from being prtreipitnled as it usually 
• by water, and even hiiHlersulludinc bodies from precipitating 
Mhuion* of the metal in acdds u« they uitiially do. 

* llerMlIn* haa reccMly itdiniiicd ttiia atomk conntiiutiAa of the acid. 
lb bnacr mmbtn w«r« ♦ C + 4 O + «* H. He \m% ■.ho«ii ihni inr- 
mneof hMbaaMnpCtnulof eVTMl okuIc nf IcaJ, and '^~-iM'i tnriaric 
S«e Pbogmlorf 'a AimbIw, xis. 30U. 




Tlte Ubtory of tlie aciil (o wtiick I ^vc thi§ name is as foU 
lorn: A maker of tartaric add M 'I'bann, a siunll town in 
WMgOUt observed mouiv ycarKiign, ilintaloii^ witli llie common 
acfd he olitBiiu-d portiuns of unothi-r, whuli wm h-^ solubK- in 
water tban tartaric. He considered it us oxalic, and oodca- 
voured to introduce it into commerce luider that name. It was 
first sutyected to an examination by Dr. John, who Nhowed in 
1819 tlmt it is a pi'diliar iicid.* (iay-Lii^sac and \Valelin«r 
coufirmed tliese resultK in Iy2e.f M, Ke»Uier, a very ingv- 
niouH maiiu&cliircr of Hutphnric uid, in AWce, was kind 
pnou^li to prcet-nt mu with a specimen of tJiis aciil in lt^27i 
which cuubled me to verify tlie resultn of Ciay-Luiisae, and to 
determine the atomic weight of thk acitt, aitd a fe«' of the salt9 
which it fomu with bawtu Diirin^ (h^- C(iHr>« of tlie J^ummor 
of I imo, the naturir of thi» acid occupied tlic Htlcniiori of Ber- 
7.eliu», lu appears by a notice in Brewster's Jounial4 ■ 

Guy-I.ii^sac informs us, that during a journey through the 
department of the Voiges, in company ^t'ith Dareet, they >'i!iiie<l 
a manufactory in whicli tartaric acid wa^ made by decomjKiHin^ 
tartrate of lime by mciuiv of sidjjhuric acid) iin<l that the nuinu- 
fiu;turcr put into tiis hands a c|Uiuilily of aci*! crystal-* obtained 
<luriii|; hi:! processes, apparently ditferent froin the crysialtt of 
tartaric acid. 

The crystals of thiiin«w acid, aa 1 received them, were largo t 

Utit b;id bi-rn ho much injured by shaking in a phiali^B 
that it wa^ impowiblc to make out the tthape. Oa^H 
diseoking them in water, and cTjstallistiiig a second 
time. I obtained doubly ul>lique fuui^nidei! priMOh 
having one of the edges rcplacct) by ihi- narrow 
£tcc a. P was inclined upon M or M' at about 7&% 
and M wiw inclined to M' at about 69°, ateusurtd 
hy a common goniometer. 
Tltespficificgwu-iiyofthccrytttalMwas 1-600 at (>0°. It lias no 
Hmetl, diswlves reaiUly in water, law a very »our taste, and red- 
dens strongly vegetable blue colours. Al tb(^ common tempera- 
iBreof Ihcutimwpherc, the crystals of this acid re*juire 6-7 limes 
their weight of water to dissolve them ucconiing (o Walchner. 
When vinic add, saturated witli a base, is mixed with a solu- 

• Haixiwonctbai-li dcr Chemie, iv. liA. jfl 

t SLliBcigger's Juhdwch, x>iil. 3Ht, and xis. 238. rW 

I Btewter"* Jouraal (new series), m. aWj nbo in fofBCiidofTs Aoo- 
xiz. 319. 






^^^ COM 


Dl<. IL 


tjon of moriate oT lime, a while precipitate fulU, wliJch is not 
witli tartaric aciil. Hut lilte tartaric adil it forms a . 
eryitiiJUiiv previpitaK- wbcit <lropt iit excv^s into a solu- 
^tioB of potuh or ila rjirhonalc. 

^K ^\llrn kcatiMl with deutoxido of mangntifsc and sulphuric 
^HkU. it Kivvs out much carbouic acid ami Home acetic acid, hut 
^■M formic acid iieet».4 u> \>v formed. When healed tt bum.'*, 
^^^ tf (Ihtilleil it ^vi-4 out much acidulous water, iuu) leavra n 
Vight bulky coot. 

Gi^LAmw! atatmtlieiitoinic wfi^htof tlii^ add lobe almost c<miiniuaa 

A* mme ivs lliul of Lirturic acid. And Ik'ncliuv stMcn tliat it 

b fxactly die same. I aDalyr.ed the viiiat« of lime, wliicb is a 

wUtc taaoluMe powder, and fnund ita constituents 

1 atnu) viuic acid . 8rli 

I atom lime . . . 8*5 

9 alAmi water . . 3-35 



TU* mniU wm eomihoratiMl by un aiinly^is of vlnutv of Icod^ 
•Im a wltilr insoluble powder, whidi 1 fouitd composed of 
I utom vintc scid . , B-Q 

1 atom oxide of lead . . 14 
1 alOBi water I'lSd 


Jiiig to tlieM analysCN the atomic weig;lit of thii actd is 

'litis '» a little hifriicr than the atomic weight of lurtariA 

lit ON I did lurt make a rii^itl v«ra|mri!uiii bi-twit'ii tlie two 

I do not curisidnr my nnulyiws un Nulficicntly rifpd to settle 

ptmiL Bt-iui; Ifcnor^nt of tlie iiuml>i;r wJiidi Ik-rxelius has 

pt«-d fur tJie Momie weight of tarbtric neiil, I cjiiiiiot judge 

iMTJir my determiiuitton comes to that of Hvrzcllus, 

luutid the cryalala of viuic add cum[iosed of 

1 aturo acid . . t^o 

2 alum* watur . . S-35 


they differ in their coui portion from tlie cryatnlR of tar- 
Should the atomic weight of thl« ucid turn out the same as 
1 of tartaric aciiil, we will be obliged to conclude that the atoms 
rhicb botli are compoeicd are the same. Tht-y would then l>e 
ia tlw tame predicament as phosphoric and pyroplioephorlc ucid. 






Tli« salt called tartar svpumtei* from wine white in the cask, 
un<l is fifteru'ards puriiivd by solution in water juiil subKCquenl 
f%'aporali»ii. This salt occupied tlio attention of cbrinists very 
much from the time of pDnicclsuH. nlio first brought ii into 
vogue. It was considered m un acid sdt of n peculiar nature. 
Tlic potiLsli which coniilitutes its biisc wns easily discovered by 
Bubjectin^ tin- salt tii combustion. But the efforts of chemiBts 
to obtain the iicid which it manifestly contained were long 
iinsuccessfuL AVlieii tartnr was dUlilled in a retort, an acidu* 
lou» liiitiid yras obtained; but it wiu munifcMtly ditferent from 
tlic acid in tartar, as tartar was not formed when it wii» united 
to potash. At last in 1770, Sclteele discovered a procetui by-_ 
which pure tartaric acid could be obtained from tartar. '^^H 
propcrtiri* beini^ manifestly different from that of tlie acid 
obtained by distilling tartar, a» fur ns could be collected from 
the rude experiments of the Dijon Academicians,* the French 
chemlita when they contrived the new chemical nomenclatniV 
distinguished lliem by the iiamei^ oi tdrltmniji ami //yratarttrnMU 
acidu; which were aflerwards eluinged into thowe at tartaric 
and ]>!frt}fartarirac'iA)i.-\ In the year 1791* a set of ex)HTiiiienls 
was published by l-'onrcroy and Vauqueliii un pt/rwtiwout, 
pyrotartttroKf, pyrttti'jnou* acids, the object of which wu to 
prove, that tlio§e aeiih are merely the acetic disguised by some 
empyreumatic oil, with which it has combined.J This conclu- 
xioii appears to bavo been accpiiesced in by chemists without 
examiniition ; tliough the proofs a« far lu regards the pyrotar- 
laric acid are lar from sati^foctory; till Gehlen called it in 
cgucstion in iHOfi, alBmiing llial pyrotartaric acid diffeni esseii- 
lially from acctie> and otnliii)^ some chaiBcters by which they 
could be euidly distingtuslied.^ Tlils induced Fourcroy and 
Vauquelin to repeat tlieir experiments in 1B07.|| The result 
was a full coiilirmatiun of the opinion of Gehlen. 

Pyrotartaric acid may lie obtained by tite following process: 
Distil a quantity of tartar in a retort, Saturate tlie acid liquid 

* Elcmcnifl dv Chjtnie ile I'ArRileinie de Dijon, iii. AA. 

t It HOB Morvouu, io ilio ftr»t vohimc or tbc cheiuicol port of the Ency> 
clopardio Mclhodiijiic, pulilUhcd in l~b(>, that Tint drew the nllcnlfun ul' 
chemlsu lo pynitorlaric acid, nnd endeavoured to climactcriic it na n |ici,'iiliur 
add. His charoctcf* were inoccLirsic, becauM hehutneicrohioincdit in n 
■(Bte of purity. 

I Ann. dc Chini. xxxt. 101. $ Ibid. Ix. 19. ) IbiJ. Ixiv. 4 

Uv.lL . 

tlie receiver with potasli, 8e))aratc the gall liv cry«l»lli£nLion, 

Mai purify it by repeated solutions an<l cryKtiiUi»itiati». Mix 

tkia nit M-itb diluted sulphuric acid, nnd distil in u retort. An 

idd liiiuid passes over, aiul towards the end of the proccM a 

rhitc sublimate risen and attavheit itself in soiles to the lo]i of 

Ite retorL Tlua sublimate n pjfrolarlanc add. When tlie 

liquor in the receiver is subjected to spontaneous evupo* 

it depflAilea cryitiilH of pyr<>bir|jiric acid. 

The taste of pyrolartaric acid it extremely acid. When '"n^nn*. 

it melts, and 8ublinii.ii in a white smoke, without leaving 

residue-. It diMolres readily in water, und crystallizes 

. wfarn «ubjectcd tu sponlaneotts evapornlioii. It do«-N not 

lipilnle acetate of lead nor nitrate of silver ; but it prccipi* 

nitnte of mercury. Some time after it l«w been mixed 

?tate of lead, ncedlefonn crystjds make their appi'arance. 

V^en combined in exceM witli |M>tjMli, no salt similar to 

w formed. In this state it instiuirly forms a [irecijutale 

dropped into acetate of lead. PjTolartratc of [wtnidi i>* 

dable in alcoliol. It doiM not precipitate tbe salts of barytc* 

I lime, a.s tartrate of potjuli doct.* 


Chemists have iilwayn cutnidered tlie juice of oran^s And "^''^• 
IroDona as an acid. This juicecontuinsaiiuantity of mucilage 
and water, which renders ihe iicid impure, and subject to spon- 
tMWomdeoompoNition. Mr. Gcurgi took the tullowiriir method 
to separate the miiciluj^ : lie filled a bottle entirely with 
leawih-juice, corked it, and placed it in a cclhir : in four years 
(ke Li(|uid wa* become as limpid as water, a quantity of muci- 
lag« kid bllcn to the bottom in ibe form of flakes and a thick 
cnut had formed under (he cork. He exposcil this acid to a 
ooU uf '23", which froze a great part of the water, and left 
brUnd a strong and prelly pure aci<l.f It wat Scheele, how- 
ever, that tirst pointed out a inethotl of obtaining lliiw acid 
perfedly pure, and who demoiutrated that it {mmmwcs peculiar 

His proccM, which is still followed, is this : Saturate lemon 
juice, while boiliny;, with powdered chalk. A white powder 
blhi to tlie iwtlom, which is lime combined wltli citric acid. 
S«pamt« lilts powder, and wasli il with wann water (ill tlie 


• Ami. tic Cbiot. Iiiv. tv. 

f Kon|^. Vaicinkafii AMdcaicna llandlint^ir Tor 177i, |x SU 





*^^i^ *■ Witter postefl off otiluurle^s. llii>n pour upon it «» much sid- 
phnrif at'iil Ua will Kuliinik- tin.' clialk ein|tloyc(t, burln^ pre*-i- 
ously diluted it vt-itli six titnc<> ils wi'iglit of vtaicr. Iloil Uie 
mixture for some ID iiiulea, au<l juass it tltrougli a filter to separaufl 
tlie Miiljiliate of lime, Tlie liijuid It tlieii to l>e ev.ijtuniteii to 
the consixtc-iico uf a »ynip, tuul m-l nsidv to cooL A oumb<.-r of 
crystals form in it : thctic nre citric atid* fl 

Mr. Sclieeic advimn tie use of an exoess of sulphuric acid" 
in order to ensure the separation of all Uie lime ; but according 
to Dice, tliiH excess U necessary fur aiiotlier purpose.f -^fl 
qiiniitily of mucilage, Iio tliinkit, trtili ndlu-res to the t-itric acid™ 
ill its coinI)i nation with lime, luid sulphuric ucid i^ ncc<>»utry to 
decompuM- this miicihifjpe. 

Frou^t, who published a memoir on the prc))amtion of citric 
acid in the Jouniul de Physique for I8QI4 '^as shown that when 
too much sulphuric acid is employed, it acta upon the citric acti), 
chura il, nn<l prevents it from crystal lixing. This error is 
remedied by ad<litig a little chalk, 'i'his clicmUt funnd, that 
funr partri of chidk require for saturation 94 purlM of lemon juice. 
The citrate of lime obtained amounted to 7^ parts. I'o decom- 
pose thL4,20 parU of sulphuric acid, of the speciiie gravity 1*1^ 
Vfetv iicccssiiry, 

TbccrystHlsof tliia acid are of a very irregular lijTure. They 
are prisms of 6, 8, or 10 jtidet*, termiiiutcd at eitlier cxtrcmily 
by an indefinite number of face«. Mr. Brooke hue eliuwii iJiat 
the primary form is a rtjfht rhombic prism, whose Jaces make 
mngles of 101" fltCj Tbcy are not altered by exposure to the 
■ir. 'i"heir specific gravity is 1-6 17. Their taste is exceed- 
ingly acid, and even excites pain ; but when the acid is pro- 
perly diluted with wat*'r, the acidity is plcuwinl, Tliese erys- 
luls contain combined water ; and, therefore, are in the slate of 
n hydrate. Accordiug to the aualysis of Ucrxclius, |j tlicy are 
cQinposed of 

Real acid 
I have sliown tliat they eomiat of 
1 atom acid 
3 atoms water 



• Schede, IL 903. 

X Jour, lie Ph>'s. lil. 36Q. 

U Ann. die Clilm. buxii. Itffl. 


f Nicholtion'* Journal, ii. 43. 

f Anub or Iliil. (?d acrica), vL 11 

t FinI frinciples, iL lljl. 

arjiic ACID. 

TU* vrnter eannol b« drivon oS by kcat. V' Iimi their lem- 
ptnuurc U raised they melt BTid (hen biNwrne yellow or browii, . 
nd form n tJiick syrup which ciiniurt f>e cr.-6talli]!e<t. 100 parts 
«f tfie arid, when kcpi nt Huch a tcmpeRitiirt^ tn to be rc<luc«l 
lo the stnt* of a whitir puw<lvr without utKlcr^)it|r <lccomp<MU- 
liaa, loM iihtNtt 7 per cent, at water. This ajvjjiruiches to the 
thtnt pan of the whole water contained in the ncitl. ln<lcc<l 1 
lure detf mtined by actiinl experiment, llint the loss of weig;ht 
i» jwst une-thini of the water.* 

Citric acid is exceedingly soluble in witter. According to 
Vuiqiielin, 100 part* of it rrqiiirc only 75 parts of water. 
Bailiufr u-Mter dLs»»Iircs tma' iu weight of it.f 'I'hiti Mtlutioii 
nty be kept n lon^ time in close vefneU ; howe\-er, it at last 
jNtrefies, and ts decom]>ased. 

Neither oxygen gas dot tlie sirople combustibles or inoom- 
boMUiln produce any effect upon it It is capable of oxtdiKing 
bin, dnc. tin. It docs not act upon gold, silver, plutiuuio, 
Btreory. bismuth. Dntimonvi artcnic 

It eontbinei* witli alkalies, eartlis, and metallic oxides, and 
(onut m\m known by tlie name of citratm. 
The action of none -of the acids on it Imx been examined, if 
except tliat uf the sulphuric and nitric. Sulphuric acid, 
•a eoncentnitod, converts it into neeticacid.^ Scheele said 
ilbat be couhl not convert it into oxalic acid by means of nitric 
■i he had doiie several other iwidsi bill Westruinbafflmw, 
tliio conversion ma)' be •.'tTvch^'d ; ai>d thinks tluil Scbeela 
had prubiihly failed from huving used too large a qoantity of 
ilrie acid, by which he h-id proceeded beyond tlie ronveraion 
oxalic and, and Wt cliiinged the ritric ai:id into vinegar; 
In support ul' hi< opinion, he quotes hi« own experiments; 
which it a|i|ioarc<l ibiit, by treating tiO grains of citric acid 
jih ditTerent quniititic« of nitric ncid, his products wen* very 
n-ni. 'Iliiu will) 200 grains of nitric aclt) he got :)0 grains 
of oxalic acid; will) 300 grains of nitric acid he obtained only 
15 gniint of the oxalic add ; and with (300 gmins of nitric acid 
BO VMtifrB appeared of the o-xalic acid. (>n distilling tJiepro- 
doeta of these experiments, v^peciaUy of the hwt, he obtained 
irfaiegar mixed with nitric acid. The experttneata of West- 
have been confirmed by Fourcroy and Vaiupiolin ; who, 
dtrio acid with a great quantity of nitric acid, oon- 

M*. IL 

+ Di«i. 

I Foaccroy, vii. 806. 


verleii it into oxalic nn<l ncotic aci(U. TLc proportion of i]ie 
lirtl viw iniiclt smaller than that uf tliv spcoi)d. 
CMDiiuKtu. According to tlic atinlysis of Ucntvliiis (corn.*«te<i a Utile l»jr 
tbcorctic views), citric aciti is comjioscd of 

Hydrogen . . . 3-42 

CarboD . . , 41-84 




is equivalent 
2 atom It 
4 iitoiDs 






4 atoms 




Now as tliesc atoms give u» liie true ntoinic weight of citric 
add, there cnn be no dotiht tliat Uie rcNiilt jtist given repre^nts 
the true atomic composition of tliis acid. My own analytical 
results, 80 iar as tlicy go, coincide witli thowc of UcReliiis.f 

UMoiy. This acid was (Uscovered by M. LasMiigne,! to whom we arc 

indehte<l fur all thi- facts ri'ii]>ei.-tiiig it hitliiTtci atcertaiiied. 

When citric acid is distilled in a glow retort it fuses, water 
passes over, it then becomes yollow, and tite colour deepens 
more and more, while n white vapour passes over and condenses 
in the receiver. The product of the distillation is a colourless 
litjitid swimming uppermost, and an amber-coloured oily liquid 
at the bottom of the receiver. The watery liquid lias an acid 
taste, and the amber liquid eonl.-tin.t a goo<l deal of acid which 
it gives out to water. To ohtain tlie acid contained in tlie 
liquid by saturating it with lime, imd cvaponiling the liquid, 
a .solid salt was ohtained, which divtolved in wiitcr, atxA gave 
no Hnicll of »i*ctic lu-td when rrenti-d with sulphuric acid. 

I'wo mvtiiuds of separating the pyrodtric acid from the lim« 
wore taken : I. I'he lime wan thrown down by oxalic scid ; 2. 
The pyrocitiate of lime was decomposed by acetate of lead. 
An insoluble precipitate of pyrocitrate of lead fell, which ivas 
washed and decomposed by sulphuretted hydrogen gas. 
rt^aUM. Pyrocitric add thus obtaineil h white, without smell, liavtng 

• Annuls of Pbilooophy, v. 03. 

t Ann. dc nitm. c( dc Phvi- axl. t()0. 

i Sk Firti rrinrii>lo*, u. I<3. 


an, it 

nacM niid sUgltUy bilteriab taste, and not eaoily reclucod to 
rrgular crystals, and nasaming usually the state ofa wliiir miisti, 
rampcMed of fine iiee<lleii interlaced Icf^tlier, 

W'lirti thrown upon » lioi boily it melti*, aitd is converted 
into white acrid rapoiir*, Icaring u tntcv of coal. Distilled in 
■ retort it gives off a yi-llow-ish suur-Uuted oil, and is partly 
■koompofied. It is rery nolithli- in idculiol ; and n'ater at tli«! 
kmp<-rature of iSO°, dissolm the third of its weight nf it. 

ItH iu|ueo(u solution reddens litmus paper. It ncitlier pre- 
cipitates limi>- water, nor harytea-water, nor any of th« metallic 
nlutions Irit^d, except aeetitle of lead and nitrate of nicreiiry. 
IrViih thf different bases it forms siilt^ which hav«- received 
the name o( pj/rocilralen. 

\ iMniimif amureN un tlwt it^i vtitnniiing power u prociKclv Ainaic 
that of citric aad. But from the diffi-reitt itnalysi'ft of the pyru- 
dttues which he bus ^veii, it is difficult to come to any coii- 
doiiotu The pyrocitnilc of horytcs he found coinpmed of 
Pyrociiric acid . 7-43 

Oarytes . . 9*& 

The pyroc-itnUe of lead of 

Pyrucitric acid . 7*01 

Oxide of lc«d . 14 

While tlte pyrocitrate of lime was composed of 
Pyrocitric acid . 6-8 

Lime . . .'J-S* 

These three salts give us 7-43, 7-01, 6-8, for tlie atomic we^e 
of tartaric acid ; the mean of which ut 7*08, which is below 
I tJie atonic weight of citric add. If we wen- to leave out llie 
jwialyus of pyrocitnite of lime as uncertain, the mean of the 
[other two would give u* 7-'2'i for the atomic weight of this acid, 
a mult very near tliat of citric uctd. lint Lussaigne analyzcil 
it liy heatiDg pyrodtnte of Icud witit bhick oxide of copper, 
\ and obtained for its couHtituenta, 

Hydrogen . . 9 

CatboD . 47-5 

Oxygen . . 43-S 


■ In liumgMs'* P^pc the Mtt is Mud to be composod of 
l^rrolartwic ncid . , 3i 
Llaia eo 

— too 

But I wppoM iIm nnnbcn to bsvc been iiivericJ hy the prinicr 




NvlMJlfe f KmlleAt nuinl)er of atoms which would corretpond 
wiUi the CviulitiieuM ui these proportions is, 

1 ttlout hy<lro^cii , , 0*195 

7p iitums ctirbua 
5 atoms ox^gco 



Tliw n'otilil mnkc tin* ntomic w-el^ht of iJie aci«l 10-75, a aata- 

Wr qvilr at variaiico witli thut resulting iVom Cie Mtalysis of the 

tpyiocitratea. It is obvious from this thut some of these rMiilts 

I JHwivurai*, ami that new roscarchcs are netrssary l>efore we 

jUMuiy acvtirntL' know-Uslf^i; vilh<.T of the atomic weight 

or atomic coMtitiiotitJi of thi» acid. 



'HiU aci<\, which wm diiwovcred by Schc«l« In 17S4, 
recQivcd tli« name of mnlic acid, becauso it may be obtaiucd in 
abundmici; from the jittrc of apples, in which it exists ready 
formed. Schi-cle hn» given us the following process fur oxtract- 
iiig it : Saturate the juici* of apples witli potash, aiid add to tlic 
solutiou acctaie of lead till no jnore precipiUttiou ensues. Wtuli 
the precipitate carefully with a HufRcient qtiaitttty of water ; 
l)iei) {H>ur upon it diluted sulphuric ucki till lite mixture hua a 
I perfectly acid taste, without any of lliat twecUieKt which is m 
I perceptible as long as aiiy k-ad remaiiiH dlsitolved in it ; then ■ 
tfepoiute the sulphate of lead, which luw precipitated, by filtr»* 
ti.00, and there reinaiiiK Whind malic acid.* 

M. !tracoiini>t lina idtuwu that when malic acid is obtained by 
; Ibis procesN of Schcele, it is contaniinatnl with a mucilaginous 
mPei'* iaiennedittte between sugar luid gum, which masics all 

^-^VauifUeliii oscertoiDed that it may bccxtrscted, witli greater 
kad^antage, from the juice of the aempe/vivvm twlomm, orcoro- 
rmoii house-leek, where it exists abundantly, oombiiiiil witli 
lime. The process which he fiiiin<I to answer best is the follow- 
ii^: To tlie juice of the hoii-se-leek add acetate of lead as long 
OS any pn-cipiiuie tuke>4 place. Vudi the )irecipitate, lutd 
d<:eompu«e ii by moaiM of dihtted sulphuric acid in the manner 
directixl by Schcelc.J 

Gay-Lussac lin» shown thut when malic acJd is obtained in 

• Svodwli Tram, mid Crc1l'» Aiiniiki l<ir 178^ 
t Ann. de (^im. ct de Plij-s. tUi. 149. 
«| llad.)ixxK. 187. 




Itis wny, it still rptaiiM » (|tiantity of timi-t from-whidi it may 
b* freed by e%-iiponitinp; it to the ocMiBtstence of a sSTup^'iiiKl 
mixing it uitli iilroJiul. Malate of lime Is precipiiuU-il, iiiiil lli« 
Bilic tund imuiitu liiiisoUed in the alcohol.* Uui du* aciil ovt-n 
vhcn ibiH ]>tiriA<-<i, rt'tnins the mucilagiitfluit matt«r with wbicb 
it u contaruiiiutccl when extracti^i fruoi llw jiiiou of appleit as 
Bncooiiut has shown. t 

In the year 1813, Mr. IXnmrjui iimtniincvcl the existence of i''"!"""' 
a new scid in tlic expiewcd jiiicv of the berries of tJie pjfrut 
WKvparia, to which \\e gave the natne of aorhic acid. Hit 
metbDcl of ])r(K-uring this acid was the followii)g : 

Tbo tH-rricH arc to be collected when fiiUy rijte. They an 
m br first bruised in a mortar, and tlien sttueexed in a linen Ita^'. 
They yield uearty h;4lf thdir wcii^ht of juice of llio i>]>cciil« 
gravity 1-077. 'I1tt« jiiicv is to be stniiiie^l <uh1 mixed with a 
fillrred mltitiwn of acetate of lead. Separate Uie precipitate on 
I ■ &har, and wash it with cold water. A targe qimntily of boil- 
'bg water ia then lo be poured upon liic HIter, luid uilowe<l to 
m tlirougli the precipitHtc into glawt jaoh Aflcnsnn^lJvtm 
thii iii|itid hecomcM op«K|uc, uud depositee cr)'HtHW^of fmU Itistro 
iiimI bcttuly. The nutter remaining on the filler luui now 
fWoMne liani and brittle. Hut it UKiy i)e made to furnish more 
'smtaht by the following tn-utinent : Doil it for liulf an IwuT 
I (rith miher more diluted sulphuric acid tlian i^ MilTicienl to 
'mXMMa the whole kad which it contaiiM. Filler the H^jiiid 
Hid trMt it agnin with acetate of lead. The edulcuruled pre- 
cipitate, when treated an before with boiling water, yielda aa 
•dditiOBa] crop of ery^tal^ Thi^ procei«i may he repented till 
■kDHt the whulu iK'iil has been obtaiix-d unitt-d to Ic-ad in a 
[ crystallbed stntr. .,,1,^,, 

CoUoct the cr)-stahi formed, and boi) litem for hidf an liffiv 

I with 2-U times their weight of sulphuric acid of the t(|K-(:itic 

gravity l*0!>0, supplying water as fast as it evajmniles and 

taking car* to keep the mixture con!<tantIy slirrvd with a ghtss 

I ml. The dear li<]tior i.s to be )M>ured off aiid put into a tall 

[l^liim jar uf funnll d>:un<-ier. Wliih^ still hot, a sueuin of sul> 

^nrettrd hydrogen ^iu k to be ]Nis.t<-d llirough it. Wheti ihu 

Ind '» all predpiiBted the fluid ts to be liltiTi>d aitd boiled iit 

Ian rtpi-n limin till tite sulphuretted hydrogen is dl'iengag^'d. 
1'he licpiid now coii&isI» uf water, holding s<tfMc acid iii 
■olution.t . , , 

• Aim. de (1iiui. el tie Ptijra. vl. 3S1. 

f Ibid- voL viii. p. 1 40- 


I Cup. r. 


M. Rraconnttt lias pivcn m tiu" following proco«8, for eit- 
tractiiig tlii.t acid from llic bcrncti of tlio pyrtis niictiptiriii, wliich 
lie recomtnoiick as easier tliun tin* process of Donovan : 

Thfl bcrrii'iS arc to be takt-n before they arc ripe, pounded 
in ii tniirbU' mortar, and the jutce squc«zcd out by a strong 
pri.<8Siirc. TIk- juice i§ lo be Lcaled in a capoiile, to the boiling; 
t4'mperaturc, and carbonate of lime is to be thrown in as lon^ 
M any effervescence coutiiiue§, Eraporate the liquid to the 
conflifltence of a xyrup, taking care to skiin ofT the scuia in pro- 
portion'M it cnllcctii^on tlic snrlace. A granular prccipitiite of 
sorbatc of lime lidlx, whicli adliorc^ strongly to tJic vessel, unleM 
cure be taken tu «tir the li<]iiid from time to time. After an 
interval of nome hours, decant off the syrupy liquid, and vranh 
tlie pri'ci|>ilat4! witli a little cold water, 'i'hen Ktjueexc it in » 
cloth and dry it. 'Hie colour of ihi* malt it fiiwn, indicating 
that it is not free from llit^ mloiiring matter of tite berries. 
Boil it for a quurter of an hour with a quantity of crystallixed 
carhonatc of soda equal to it in weight, and n sufBdent quan- 
tity of utiter. A doulile decomposition lakes place, nnd tlie 
liquid retains in solution norbute of soda, mixed with a quantity 
of colouring matter. Tliis colouring matter is removed by 
heating the liquid for some time nHth lime water, or milk of 
lime. The liquid when filtered becomes quite colourless;. A 
current of carbonic acid gas passed tlirough it precipitates the 
iime n-1aincd in solution. The liquid thus frcc<l fmm colour- 
ing matter is to be precipitated by Kulncelale of Inid, and the 
sorbate of lead may bo decomposed, and the actd obtained in 
•olutioii in water by digesting it with tlie requisite quantity of 
dilute sulphuric acid.* I have repeated this process of Bra- 
connot very exactly; but did not succeed in freeing the ncid 
from the colouring matter. The l>erries wlitcli 1 employed 
were fiilly ripe, while IJniconnot's probably were green. Fci^ 
hapB tliis may account for llie diffen'uce between out results. 

In the year 1818, Draconoot made u set of c:(pciimcnts on 
tnalic ncid ^m ttie juice of the apple, and from the loares of 
tlie Mfviprrriruin Irrli'nnn. or hottsr-fnJt, and demonstrated that 
when freed frtwn ihc. mueibgiuous matter, with which it is 
usually mixed and db^ised, it possesses exactly tbe prf^rdes 
of sorbie acid.f licnce it follows tliat sorbic acid is not a 
peculiar acid, as Donovan supposed ; but merely the malic acid 
of Sclieele, in a state of greater purity than that eliemist had 


• Asi). lie Chitn. cl de Phjs. vl. 841. 

t IVid. vol. viii. p. 149, 



|1»eea ait\e to oliiwii ii. Of course wc must (troji one or otlier ^^ 

Tlbeae two terms, aitit us Sclieele wns undoiibtcslly ike fimt 

BTcrcr of tilts Kcid, though he did not §ucc«cd in proairin^ 
I • ttttitd of purity, it se«ms tiut lair to retain the name malie 
wliich tliut iUustriauA chctnl'it orij^inally bestowed on If. 
Dnconnot oUtainod pure? miilic ucid from tlie juico of the 
-leekt in the following manner : The <'xpres!ied juice of 
plujil was fvaporali-d to the consistenM of a s.ynip, and 
i>l tuning gnidiially mL\ed with it, tlircw down the preci- 
' nsaany considered as maJate of lime. Thii* precipitate 
I p wa ed strongly in a doth to free it as completely as po«- 
of the nodiariiie mailer with wtiieli it was niixt-d It 
I tlieD dMolve^t in u'atcr, to wliich it communicated u t>rowti 
ionr. Sulphuric acid wm udded to Uie liquid in such quiiu- 
u only partially to di-cotnpo«M.' the taU, and the liquid mta 
ilterei} in order to separate the sul])hace of lime prfcijniated. 
[The Uqui<l, uhicfa luid now a decidedly sour ta»te, bfing set 
>!de for S4 hours, deposited a colourless sait, conr>istiug of 
ate of lime. This ult lieing ri'ilis»olved and er)ilalli»-d 
riy, formed six-^ide*! Aat priMiu, tenninated by bihedrid 
ititK, of the puroNt whiti; colour. These crj-stuls bein^ 
Iretl in waU>r were decomposed by sulphuric acid, and in 
In gv't rid of all the sulphuric acid, tlie filtered liquid was 
eA over oxide of lead* and the whole being filtered, a 
current of sulphuretted hydroj^en gas was passed tbruiigli it (o 
thrown donii tlie dissolved lead. It was now evapontti'tl to tlio 
Goniiteiice of a synip, and dianolved in alcohol to get n<l of 
tome lime and oxide of lead, not separated by the previous 
procntes. The alcoholic sohition bi-ing evaporated to tlie co»- 
Mtetwe of ftiyrup did nut cryHtuIli/e in 21 hours; but being' 
put into * alove it cry^bdlixed completely within the same 
uil«rrHl of time. Tlic cr>i)tab lirHt formed were gruupti of 
waali flattened globules of about a line in diant<-ter, and by 
degiew the whole c»ucTete<l into an opaque wlnte inasi* tuber- 
culated on the sur&cs. 

IblaJJcacid tliua obtuned is a white opaque siibfttaiice, having piu^iuih 
aa exceedingly sour ia»tc, but destitute of smell, and exceed- 
ingly soluble both in vau-t and alcohol. 

Wheu dropt into solutions of nitrut^.- of lead, nitiato of silver, 
or nitrate of mercury, it occasions no precipitate. In acetate 
of lend it throwft down a white precipitate soluble in acetic acid, 
and even in boiling water. When acetate of leu*! U drupl into 
thu acid, diluted with water, a copioiLs white precipitate &IK 



**'»"'■ vlueJt gradually rcdissolres in tli« liquid, and in ilcwly con- 
VMlrtl into very fine silky crystili, hnvin^a threat ileal of litotro. 
M'Ucii tiie^' <;r)'iilaL-( lire tKiile<l in water tliey partbiUy ditwlrc!, 
but thv gnralCi^t giiirt of them melt into a reAtnouH looking 
matter wbiclt may be dmwn out into the threuds, but vhicb 
becomes brittle as won as tiie tvinjieruturv oLnks. 

Neither Umc vratcr nor burytes wrater occasion any prectiN- 
tst« when (Iropt into tbia iietd. 

The molattmof ytoUuth luid 8<KUBrv incrystallizable, dcliquea- 
cent, niid insoluble in stroiifi^ akohol. But tlte bimalatea of 
|kota.*ih, noda, an<l ummoiiifl, crystallize. 

When saturated u-ith mngne-Hla, or with oxide of sine, h 
forms sdls, which crystallize witli the ffri-atest fiK-iUt)'. 

8cbccle considered the iiclil produced by treuting sugar Willi 
a quantity of fumuig nitric acid eqiuit to its own weight, and 
previously dihited witli it» oHii we^ht of urater, to bir dm/k- 
acid. But from tin- experiments of Vogcl, iherw is reunion to 
believe that it ooiuttitules a differeot and jteculiur acid, n-htcli 
requires further exuminatioii.* 

\'urioiLs niialyseA of maltc acid have Won made, bnt the 
reeitlt« diSer »o much from each other that wo c;in only recondlo 
them by supposing that two different acids have been hitherto 
iiiiuniti, confounded uudcr tliv name of malic aeid. And the properties 
of tills acid as they luive beeu hitherto slated, are so vagae, 
that this may very well have t>cen the ca«c. According to 
Fromnihcrz, malic acid itt cutngioiH.'d of 

Hydrogen . . 4-756 

Carbon . . 29-297 

Oxygen , . G3-947 

_ loo-otwt 

Tills is equivalent to 3-46 atomft hydrogen, 8-i)9 atoms cutmii, 
and 6 atoms oxygen. Frommbets, therefore, considers it » a 
owapi'und of 

Oi atom* hydrogen . . t)'4.*J75 

3J atoms carbon . , 2-6250 

9 atoms oxygen . . . 6-<KH)0 

Tti* would make the atomic weight of the acid 9-0635, 
aaolyzcd tlie iiialat« of lead, and found it com])0)u>d of 



. * JlUbert's Annakn, 1^. 833. 

i SdntdKpn'f Jafarianrli, STii I. 


Malic acid 
Oxide of lead 

09-2725 or 9-0&3 
GO-7273 or 14 

CM* I.' 
Dl«. II. 


According to ihu snalyHui, the atomic weight uf tlic ncid is 
Bi)a3; wliicli n^eN very iioaHy u'itli the nnalydcal result 
' abtainnl by dvcoin[>un(in^ nudic acid. 

Ih-. Prout ltk«vi»c stilijccled tlie malic acid from Ute berricji 
•r the mountain ash to an analyaU, and obtained 
Hydrogen . 6-08 

Ciirboii . . 40-68 

Oxy^u 54-24 


' Now tlic smallest ntunber of atoms that corrcsiwiid mth tlie«e 
proportions ifl 

1 atom bydrogen 0-125 

13 RbMns carbon . . 9-75 

13 alanu oxygon . 22H)0 


would msko the atomic weight 22-875, n number utterly 

' irreconcilable with that obtained by Frommhcrz, from i-xperi- 

mrnti wliicb appear to approach very near the truth. Dobe- 

Ktacr'ti analyMA of the same acids gives quite different resultn. 

>g to him it U eotn|>0AC4l uf 

1 atom hydn^n . . 0-125 

2 aUKDM carbon . . 1-5 

3 atoms oxygen , . S 


; U oltriouitly the constitution of fonotc acid, which Dobe- 
nuot hav<' Homehow nubsiituted for malic acid. The 
I of Bnicottnot, so far us tliey go, approach very nearly to 
llMMe of Frommhcrz. TIii'TC facta teem to Ivjul to the conclu- 
I doa tliat tvo different acids have hcen eonfoundcd to^'ther 
^^ imdn' Otir Mine name. That one of them Iiik been analyzed 
^■by Froinnihenc, awl tlie other by Prout. But this oliscure 
« Hultject can only be cleared up by future rosearolies. 
1^ Then* are four acida which have been distinguished by 
^■VfTuliar munn, but which posseiH properties so nearly rcsem- 
^^Ming tliOM of matic acid, tliat in all probability tliey are merely 
[ * SchtrciggeT's Jour. Mvi. 21i, 

H It. 


OufL I 

I lav nb- 


tlmt nciil, (li^iguitMNl by Uiv prO!i«iicv of scimc f<»reign mMter. 
nhall give a short uccoant of these ncids to this plnc«. 

1. Fimffic Acid. 
Tliia add vaa found by Bracoiiiict in the Peziza nigra, tlio 

Hydntm hjfhritlum and rejtandmn, the lioletiu jugUuidi* and 
paeudo-igniariuH, tlic P/ui/itu impudieus, mid lh« MeruUiu car- 
Ihanllm ;* and by Schradcr in the JMrtHa mitra. 

The method of ohtainin|^ it followed by Braconnet was this; 
The juice of the Bnletnit juijlastdin wiis obtained by preRSure, 
ami the dry ro»iduo was washed witJi water. The li<)iiiil tliiii 
obluined was boiled, and the albumen which had coagulated wii* 
separutcd by tlie filter. It waa then gently evaporated to dry- 
ness, and the dry residue v.Mi wfU waKhcd with alcohol. Tlio 
portion left liy tlie ulcuhol wa* dissolved in water. Acetate of 
lead being dro]>[ied into lite solution, bolclate of lead was tlirown 
donii in ubundaneu. This fungntc was colieeted and wa:«hed 
on tlie filter. This salt being digested with dilute sulphuric 
acid a brown liquid vi'as obtained containing fungic acid, phos- 
phoric acid, animal matter, &c. Being Kiturated witli ammo- 
nia and evaporated, crystals of fungate of ammonia were 
obtained, which, being redissolved and m'stulli/ed and subjected 
to pressure betwecu folds of blotting paper, were pretty white. 
These crystals were dissolved in water and the acid again thrown 
down by acetate of lead, and from tlie precipitate pure fiingio 
acid was separated by means of dilute «ulphtiric ukiA. 

The acid tlius obtained was colourless, would not crystallize, 
had a very sour taste, and when evaporated to dr^'netw absorbed 
moisture from tlie atinonpliere. It does not tltrow down Hme 
from a sobiUon of the muriate, not even when in the stale of 
fungnte of potash. Such are the characters of tliis add given 
by Braconnet, tt^ether witli a ver\- short account of Kume of iia 
salts. All these clianicters will apply to some of the acids that 
have been described by chemists uoder the name of malic add. 

2. Igasvrie Acid. 

This is tlio name by which I'eltetier aitd Cai-entou liave 
tliought proper to distinguish an acid, which exists In St. Igiia- 
tius's bwui, the fruit of the stry/tntKi iffualin, in which they first 
detected the new alkaline substance to which they gave tJte 
nune of ttri/cAnim. 


■ Ann. lie Cilia). Ukix. 203, and Uxxvii. StS. 

I UCCIC ACID. ^^^^^^ 83 

IgMurio acid was obtained in the fuUowiiig manner : Tlte ^^^ >■ B 

oiagneMn hy mmii« of whi«li the otryclinine bad been separated '.. 

fnm the infu«inn of St. lifimtiiw's bean, was washed in inild '"t^ooim, 
\ mter to <Ifj)rir*' it ns completely a* possibli- of tlic colouring 
I auitiT with wbidi it was mixed. It was then boiled in a great 

(juantity of distilled water to dissolve the igasurate of tnagne- 
I n The M>lutJon being concentrated by evaporation, was 

■HJted with acetate of lead. A <louble decomposition took 
[ pboe, and the ifpuurat^ of lead was precipitated in the state of 
iwi—alnblf (wwder. Tliis powdvrw&t mixed with wat«r, nnd 
[ ihr Irad vcparutrd from it by mean* of Kiilphitrettvd hydrogen 

giw. Tlie igasuric acid dissolves in tiic wuter, and may be oIk 

tain«d m a separate state by evaporating that liquid. 
[ The oaly diaraeter by whidi this acid is dlstinguisbed from 
I tke mnUe ii the property which it hai of precipitatinji^ copp«r 
I fat tke stMe of B grccniid) whiti^ ))on'<ler, and by ihc solubility 

«f itsnikaline salts in ulcohoL 

I 3. Laccic Acid. 

\ This scid was obtained by Dr. John from stkk tac* Hia 
I |WiiMw was the following : Slick lac was reduced to potvder, 
f and digested in water as long iu it cummnnicated any colour. 

The aqticotis solution wax e«-upomt<rd to tU-yness, an<l tbe roM- 
I due digested Id akohol. lliv ahwhoMc solution was likewise Piqwiuoa, 
I ««a)Mcated to drj'ness, and the dry rcHidtie digcKled in eilicr. 
I The eth«r solution being also erapofati-d left a »yrupy mass of 
la liglit yellow colour, which being again dissolved in alcohol, 
^oad the sattution oiLied with water, lets &dl a little resin. The 
' liquid niiw voniaiits tlie inccic acid, united n-ith a little potash 

and lime, from which it may be sejMirated by precipitating it 

with lead, and decomposing the lac-cnti- by means of a quantity 

of sulphuric acid, just sufGcienl to satunile the uxidc of lead. 
> Thua obtained, it possesses tbe following properties : 

It b capahle of orytlallixing. Its colour is wine yellow, Ita 

taste is acid. It k soluble in water, alcohol, and ether. 
It throws down lead and mercury from their solutions in 

adds white. But it does nut precipitate lime water, nor tlie 

nitntea of sUver and barytes. 

Whether pure, or combined with a base, it throws do^'n the 
[ «!■■ o£ iroa white. 


* lac If a tubataaoe fonneil by insect* in India. Scnling-wsx consitli 
, tUaltrofil. 


Ifi ot^miioiiiicU with lime, soda, and potaiili, urt- dcliqtiosc«tit 
and Hohiblt! in nlcolioL* 

Most of UifflO clinnicters would Apply equally well to mulic 

4. SoUmic Acid. 

This U an acid found by Peschier in tlie fruit of tl»c wltol« 
triho iif no/aiittjnn, (■■•jH'oiiilly tin- berries of tlie siiltmum niijrum. 

It cryHtallize^. It forms uith puUixh nnd ooda cry •■ tall ixabli- 
aalts. It Aon not pri'cipitatp ndts of buryteH, lime, magnpsia, 
ii\n«, iron, or copper, but it throws down sidts of lead, mercuryt 
and §ilvcr.t 

All ihcHe properties agreo willi malic acid, leaving littJe doubt 
about the nattirc of tlie acid, which cxisIh in the berries of the 

The meni*permk arid of HouUny lnw been ascertained to bo 
miilie .'ift<l. The wuno ri'mnrk applies to the acid detected by 
liracuiinot in the ])hytoloccu dccandra. 


itMoiT, Vaiiquelin first observed that when crystallized malic iicid i* 

healed, white aeedtes are rnhiiilixed at a certain lompcrature, 
constituting an acid of n peculiar nature. 'VUe same remark 
was made by Bracoiiiiot, who distinguiidied tlio new acid by the 
name oi ppro-malic. For the fullest account of its pn>pettie» 
we are indebted to M. La^sai^ie.^ 

He distilled 30 grammea of cryHiallized malic acid in u ghuw 
retort with a moderate heat. Wre water tint eume over, then 
the nci<l became coloured, and on au^eiitiii^ tin- livitt u colour- 
less liquid passed over, having' a sl^^htly bituminous odour, and 
an acidity so strong that it blistered tlie lips and the tongue. 
Towards the end of tlie proeeiw a few white needles sublimed. 
A very bulky t-harooal remained in the retort, 'Hie aci<l liquid 
being evaporated to one-half, yielded prismatic cryfttoht of pyro- 
malic acid. 

Thi<s aeid undergoes no alteration when exposed to the uir. 
It melts when heated to I17i^ When allowed to cool it con* 
cretea into a mass cr)-HtatliKcd in needles diverging from a 
centre and having a pearly Insire. When thrown upon burn- 
ing coaU a white acid nmoke iKcxhaled, irrilating tlie nostrils 
and exciting eougli, and nothing whau-ver remains. When it 

• SchwfiBKPr'i Joiirmtl, x». I l(X f J«U'- ^ Cliim. Medic, ill SS9. 
f Ann. tic < him. ec ile Phji- xi- 9% 


Mrcir ACii>. ft5 




tNilixtJNcd in clo«e vesscU the ^caUT part sublimes in long iimi 
ncrdlirs though n sruU portion undergoes (leL-oi)i])Qtitioti. 

Water of the temponilure 50* dissolves iiboiil (wif its wer'flit 
of thifl acid. It ia very soluble in ;tli-i>liul. 'I'lic aqiii-oiK sulu- 
Uan reddens vegetable biues, !kn<l prt'c-ijiihttov acotnlt- of Imd 
Mid »i(r»t4> of mercury wliitf, It docK not pri'dpilate lime 
water. When dropl into barytcs watvr u white powder &lls, 
rcdiMc^ved by tbe addition of a little uulcr, and after some time 
Ihlte rilvcr)' concretions appear on the sides of the vessel, con- 
■iting of pyromalate of barytes. This salt, according to Las- 
nigne, is composed of 

I'yiomalicacid . . 101) 
Bar>t«it . . 165- 1 -42 

If we consider thiH nit m neutral, these numbvre gire 5*191 
B» the atomic wei]|t^ht of pyromidic neid. 

All tliMe cbiravteni resemble so closely tliose of pifro-citrie 
■rid, tbait we can scarcely avoid eoni-hiding tliat the pyrocitric 
and pyrumalic comiilulc one and the aame acid. 

I-uwiigiU' examined the whit«' needier ^vhicli sidiUmod dur- 
ing llie disdilation of malic acid. He found tliv-ir propt-riies 
HoiU* tlifferout from tho»e of pyromalic. They appruueli very 
onr ln-n5n>ic aci<l, but differ in some few circum*tiiiifes. They 
an proludily rntiUed to l>e considered as a new acid.* lime 
ranclusioiis bave \twn CMifirmed by Rose.f 


Tlilt acid was discovered by Scheeic in 17tW. After having utiiMy. 
obtBtned oxalic acid from sii^r, he wished to ex»mini> wht.-tbvr 
the Mgar of milk would furnish tlie same product. Vynn four 
(lunceii of pure sugar of milk, finely powdered, he poitred 12 
•luucvtt of diluted nitric acid, and put tlie mixture in a large 
glow retort, which he placed in a sand-batb. A violent effer- 
veBCencc en«uin^, lie uiut obliged to remove tlie retort from tlic 
fKod-batb till the commotion ceased. He tlien continued the 
(BatiUation till the mixture became yellow. As no crystals 
appavod in the liquor reinnlning in the retort after standing 
two day*, he rcfK-nted the di'^tilliilion as before, with tlie addi- 
tinu of eight ounces of nitric ucid, and continued the operation 
till the yellow colour, which had di^ippoiired on the addition of 
the nitric acid, returned. The liquor in (he retort conlaiiii,-<i 
a wliitv powder, and tvhen cold was observed to be tiiick, 

■ Aan. 11>y*.n. 97. . -f- roggco(lorr« Annalcn, til 67, 



Ohp-l Eight ounces of «-Bt«r were added to dilute? this liquor, which 
was then filtraii-cl, l>y wliU-Ii tlio white powder was separated ; 
wliidi being fiiiilcoratt-d wild driw!, weighed 7i dr. The fil- 
trutcd Holution was evaporated to tlic conxiittcnec of a Kynip, 
and agnin subicctcd to diNtillution, witli four ounces of nitric 
acid as liefore ; after which, the U<)uor when cold wbs observed 
to contain many Rinall, oblong, sour crystals, together witli some 
while powder. Tlii* pow<lor being separated, the liquor was 
agiiiii distilled with more- nitric ncid as before, by which meiuis 
the liquor was rendered capable of yicldiug cr)'HtaU ngniii, and 
by one distillation more, with more nitric acid, the whole of the 
liquor was converted into crystals. These cryivtats added to- 
gether weighed five drachms, aiid were found upon trial to have 
Uic properties of tie oxalic acid. 

Mr. Sclieele next examined the properties of the white pow- 
der, and found it to be an acid of a peculiar nature, he there- 
fore called it llie acid fjf l/ir. mi/ar qf miik.* It htm afterward* 
called lae/acftc acid by tlie Fn^nch cJtemltts. J-'ourcroy changed 
tliat name into that of mucvus cKid-, because it is obtained by 
treating gum arabic and other mucilaginous niibstauces with 
nitric scid. And tliis name has been sintx altered to (hftt of 
inttcic add. 

Mucic acid may be obtained by tlie following process : Upon 
one part of gum and)ic, ur other similar gum, previously put 
into a retort, pour two parts of nitric add diluted with water. 
Apply a slight heat for a tihort time, till n little nitrous gas and 
carbonic acid gas comc« over, then allow the mixture to cool. 
A white powder gradually preci|)itateii, which may be easily 
Kparated by filtration. Tins powder is mucic acid.f It is not 
however pure, being mixed with a considerable porlion of 
oxalate of lime, and witli aliout (} per cunt, of a substance which 
is probably a compound of guin and lime. The oxalate of lime 
may be separated by (iigestii)|; the white powder repeatedly in 
diluted nitric acid. The gummate of lime U separated by dis- 
solving the residual saclactic acid in boiling waU-r, tlie gummate 
being insoluble in ibat liquid. The water on cooUug deposits 
McUcticacidin a slate of purity.} If sugar of milk be employed 
insti'^ad of giun, the saclactic add is obtained at ouce in a state 
of purity. 

Mucic acid thus obtained is under the form of a white ^itty 
powder, with a slightly acid taste. 


• Scheelc, ii. 69. 

t Lsugm; Ana. dc Chiin. Luui. 61. 

+ Fourcrojr, »u. IK. 



oil. II. 

Heat decon>[>(»C9 it Wlien dlitilled there comes over on 
arid liquor wUidt cry^italluofl in tii>nll(-« <>ti conlii)^, containing 
ppomudc acid, r rod coloured acrid oil, carbonic Bcitl ga.<i, aiid 
larlwrvtK'd hydrogrn gax. Thcrv rcmuins in the retort a large 
praportiau of charcoal. According to Trommsdorf, an add in 
ct^tals is also obtained, which possesses tlie pr4{Krt)cs of sue- 
dnic acid.* 

Mucic odd, according to Scheele, is soluble ttt 60 pArta of 
It) weight of boiling water, but Mi»«r8. Hermbittudtf and 
Morreaiit futuul that boiling water otdy dissolved g^tb part: 
it df'poAittil alM)ut {ih part on cooling in the form of crj'stals.^ 

Tbc solution lins an iwiid taate, and reddens the infusion of 
tuntsol. II Ita specific gravity, at the teniperatitr« of 53- 7°, iK 

The compoundn which It forms with earth.*, alkalies, and 
aetalHe oxides, are denoniinato<l muratts. These. Milt-s are but 
very imperfectly known, few chi'mitft having examined them 
except Schcelv. Tbc fiicts which he asc4.Tta)iied arc the foU 

With potash it forms n salt soluble in eight [)arts of boiling 
water, which ciystaliiitca on cooling. The mucato of soda 
aUo cryslallixe*, and is soluble in five parts of water. Mucato 
of ammonia lows its \wsv by » moderate heat, while tlie adil 
remaiiu behind. The compounds which it forms witli the 
«artlM are nearly insoluble in water. It scarcely acts upon any 
of tfae metftls, but it combines with their oxides ; it forms salts 
almost insoluble in water. When poured into the nitrates of 
silver, mcrcur)-, or Ica«l, it occasions a white precipitate. It 
|iroduees no change on tlie stdphatos of iron, copper, xiiic, man- 
ganese, nor on the muriates of tin and mercury.** 

Three very careful analyses of this acid have been made, the tompetiiwo. 
first by Oay-I.U8sacand 'nienard,f| the second by nerzeliun,}! 
and tfae third by Dr. IVnit. The following tidile exhlbitH tlic 
iMulta obtained by each of these divmit^u: 

Gay-Lussac 3-62 + 03-69 + 6'2-fl9 = 100 
Berzelius 4-72 + M-T2 + 60-50 = 100 
Prout 4-94 + 03-.13 + 61-73 = 100 

• Ana. do Cbiai. U«I. TO. f Phyi. Chm. t Bnojrc Method, i. «0O. 
i fjrtiwlr I Ifalii. 1 Mownu, ibid. 

■* SeliMhv ii. t^^. tt Kechercbe* PI>)-iicoM:biiBiqu«, ii. 808. 

It Aanali of niilawphy, v. I7ff. 



1 liave shown trom tlie analysis of mucate of Hoda, tliat I 
atomic weiglit of tliiit acid tit 13.* Comparing Uiis with tlie 
preceding analyscit, it U (>l>viou»ly a coinpomul of 


i atoms hy<Jro^fD 
6 atom!< c<irbon 
8 atoms oxygen 

These atomic proportions corrt-spond with 





„ BI»W>T. 


Number* not deviating much from the mean of the preceding 
analyses. Wort- wc to admit witli Kerzelius 5 atomit hydrogen, 
the atomic weight would be 18-126, and the quantity of hydro* 
gi'ii per cent, would be 4-78. This would suit the iinuly^OK of 
BrrxeliuH and Prout; hut would not agree with that of Gay- 
Lussac and Theiiard. I iim diiposed, therefore, to consider 13 
as the true atomic weight of this ucid. 


This acid was ohtaiued by M. Houton Labiilardiere, by die- 
tilling mucic acid in a retortj I'hc matter ivhich comes orer 
into the receiver in to lie mLtcd witli four timos iw weight of 
water, aiwl then evaporated to tlic requUile degree. 'Ilie pyro- 
mucie aci<l is deposited in crystals, and moic cry»taU are 
ohtatned when tlie mother liquor is concentrated still farther. 
Pyromucic acid tlius obtained melts at the temperature of 
^k- 36^°, and if tlie hciit be continued, Hubiimes in the form of 

^H yellow erystuls, which on being dissolved in water, and cfy»> 

^1 tallized, become perfectly while and pure. 

^B . . P)Tomucic at^id is white, iiuK an acid taste, and is destitute 

^^ of smell. It dues not deliquesce. It reddens vegetable blues, 

^H It \s mure soluble in hot tliun in cold water. Alcohol dissolves 

^H it more abundantly than water. Ma'^t of tlie salts which it 

^M forin« are soluble and crj-stallizuble. I'hey have received the 

^B name of pyromucates. 

^^^^L Most of tlie pyromucates are very soluble in water. The 

Fint rrinri|>1«i, H. lU. f Ann. de Chim. rl <k Vhyt. ix. 365. 



onlf metallic salta wluch it precipitates sre tlioM cwntaiinng <3>m l 
penxide of iron, protoxide of mcrviir)-, uitd peroxide of tio. _^''' "* 
Pyraraticate of ammoiiia might Ih' ttubHtituted lor bcnzoate or 
Hiiociiiat« of amiDonia for thrannng down peroxide of iron from 
ncDtisI Kolutions. 

Pyromucatc of burytcs, accurditig to tli« analysis of Houton Owiauua. ! 
LAbillartliere, is coinpoaed im follows : 

Acid . 57-7 or 12-96 

Buytes . . 42-2 or 9-5 


According to thu analvMS, tli« equivaleal number for thin iicid 
1% 12-98 or 13. 

When analyzed by means of peroxide of copper, its consti- 
laenta were found to l>c 

Urijon . . M-118 

Oxygen . . 4A-60G 

Hydrogen 2-111 


T1>e number of atoms coming nearest to tlicse proportions, 
ind to tlic equivittvnt iiumlter fur th« acid, m in<licated by llie 
ronpCMtton of pyroraucatv of barj-tcs, is as follou-s : 
^B 9 etoiDH carbon =6-75 . 51-92 

^H atoms oxvgen =6 . . 46-16 

L "-^"' ■ ■ '•* 

I prrqa 

13- lOO- 

tbeM number* coincide very n>-at1y witli tUmo derived 
'from the actual onalyMs. Tbti« the utomic weights of muciciiniL 
pyrooinric add arc tlie name, but their atomic constituents are 
[Vrry differeiiL l^e carbon has greatly increased, while the 
[oxygen aijil hydrc^ii lias considerubly dimini^ed. 


Amber ta a well-known brown, tninspiiroit, influminalde 

Jy, pretty hard, and siiaceptibie of polish, found at some 

in the earth, and on the scitcoantuf die IklticaiKl Eng- 

It was in high cstimntion among tlte ancicnl» lH>th u% 

lamaiDvni and u nu'xiteinu. Wh^-n ihi* ^iilwtance isdiKlillrd, 

I volatile suit ID obtained, which is mentioned by Agricola niuWr 

oame of taU nf amber ; but its nature was long unknown. 



Chip. L 



Boyle wns tbo Rrst wbo discovered that it wa.i an add.* From 
gucriniim, the l^tin name of ainl)er, tLis acid Iins received tlie 
Bj}pollacio» of KHCcittic acid. 

Mr. Pott Heems to liavo been tlio first chemist who made n 
set of experiint-nts to uscrrtuin its iiropcrlit-s, and wlio demon- 
atrated tliat it diiTers from every vtWr.f 

It a obtained by tlie following process : Fill a retort half- 
way with powdered amber, and cover llie powder witli a (puut- 
tity of dry sand; lute on a recci\'er, and distil in a sjiiid-U-iUi 
without employing too much heat. There pa»ies over fira an 
insipid phlegm ; then u weak acid, which, according to Schccic, 
is the Eicctic x\ then the succinic acid attaches itself to the neck 
of the retort : and if tlie distillation be continued, tlicrc comes 
over at last a tliiek brown oil, which has an acid taste. 

The succinic acid is nt first mixed wilh u qtumtity of oiL It 
may be made tolembly pure by dissolving it in hot water, and 
putting upon the filter a little cotton, prenously moi»ten«d 
with oil of amber: tills substance retains most of the oil, and 
allows the solution to pass clear. 'I'lie acid is ilicii to be 
crystallized by a gentle evajioralion ; and this process is to l>c 
repeated till the iici<l be stiJlicientJy pure. Cniylon Morveaa 
lias shown that it may be made quite pure by distilling off it a 
suGGdent quantity of nitric acid, taking care not to employ a 
lieat strong enough to sublime the sucdnic acid.f 

The crystals of succinic acid arc transparent, white, shining, 
and of a foliated, triangular, prismatic form : tliey liavean actd 
taste, but are not corrosive : they redden tincture of tunisol* 
but have little effect on that of violets. 

They sublime when exposed to a considerable heat, but not 
at the heat of a water-biilh. In a sand-bath they melt, and 
flten sublime and oonilense in the upper part of the vessel ; but 
tlie coal which remains shows tliat tliey are i)artly decomposed, n 

Oue part of this acid dissolves in 06 parts of water at the 
temperature of 50°, aceonling to Spielman;<II in 2-1 parts at 
the temperature of 5*2° ; and in two parts of water at the tem- 
perature of 218°, according to Stockar de Neuforn:'* but the 
greatest part crystallizes as the water cools. According to 
Roux, however, it still retains more of the acid tluui cold water 

• Boylr abridficd by Shaw, iti. 3iS9. 

t Mem. Ilcrlin. 1 7A% S« on nhnract of liii paper iD Ltswia** edilion of J 
Kciimnn's <:bcinistry, p. 2A1. 
} Bcrgniaa'i Nutes on Scliefltr. j Ann. lic Chiin. xxtx- lU. I Pott. i 
i Inst, Chem. 5 xii. ■* Dp ^iiccino. 



st'caxtc icio. 


IMt, U. 

b Mfnbt* of dlMolvin^." Two hundred and forty gmm of 
bulling alcohol dmolvv 177 of Uiu acid; but cryabih ngain 
iboot aa th« solution conL>(.t 

Solpburii; acid di<tsoIre!i it with iho iU8t«tnncc of linit; but 
4ofS not np[>riu- to dcc()in|t<i«o it. Tlic H»mprciiuirk !ip|>lio« to 
nhrie acid. Mtuiutic ucid bus but liltlo action on it while cold ; 
but vben bent is applied, tb« wbole coajpilates into tbe con- 
riMacc of njelly.t 

Tlw corapotinds wliich tbitt a«td fonns with alknlieiit, aridft, 
and mvtsllic oxi<l«A, have receirnj tli« mime of jnimnaftv. Tlio 
likiJiue siieviriiKoH nre Moliiblo in uiiter. This h the caseulso 
*ttb the earthy sitceiimte^ except sucetitate of biir)'tes. Hence 
baiyte* n the only eurth precipitated from n neutral solution 
by tueciiiate of aromoiiiti. This salt likcHnBc precipitates mer- 
aary aiui lead. Il throtrs down iron from all solutions provided 
Hic iron Iw in tliv Htate of peroxide, and tliere Iw no cxniw of 
and present. 

I have bhovrn lliat the atomic weight of nuccinie ndd b 6-'i5,§ c(imi«iiM>. 
iMI di » agr«e0 alniont cxiu-ily with a previutu experiment of i 

alias, who found Kuccioatc of lead u compound of 

Succinic acid 
Oxide of lead 



bUus subjected the ncid to an analyiufl, and found its coii- 



Oxygen . . 



H is equivalent to 

2 alotno bydtc^n 
4 nioiu carbon 

3 atoms oxygen 





fTbin it appear! tlwt both the atomic weight and the atomic ^,^^;^^ 
tilutiiiri of succinic acid i« precisely llie tunic us that uf 

• Uorteau, Encyc. Method. CIud). L72. 

t Waatd'B VnviodtKtiBft, [i, 305. t Pott. 

} Vim Pllac^itei, IL 1S7. I Aniuda of fbiluMph}', «. 09. 




acetic acid. Yet no two adds oui be tnoro diflcrcnt in their 
proportit'«. Il » obvious tliat the difference Iwtwocn tliem ran 
be cxpluijied only by a ilitTereiit arrangement in the atoms of 
each. If wc were to admit that alomH are capable of uniting 
only two and Iwo, forming primary compounds; tlial i-adi of 
tbe§e mny combine two and two, or onv primary with a niinpltt 
atom forming secondary compound!) ; and that each of tJie»e ■ 
aecoiidary compoundM may combine two and two, or one secon- ™ 
iary witli one ])rimary, or with one simple atom forming tertiary 

vomjioundit, &c., il would be easy to sec that compounds like 
§uccinic acid, which contain nine atoms, may liave these atoms 
arranged in a great variety of way<t, no that tlie primary and 
secondary compounds of wiiich such compounds consbt may 
I)C very different in the one body from what they are in the 
other. There is nothing, therefore, absurd or incongruoua in 
conceiving, tluit two compounds possessed of very <liffiTt'nt 
properties may liave tlie same atomic weights, and bo even 
composed of tlie very same atoms. Bcrzeliua views acetic 
neid ait conliiining one ;it»m of hydrogen more than succinic, 
and thinks this difference sufficient to explain the very dif- 
ferent properties of the two acids. But I consider my expe- 
rimentH on perfectly pure and crystallized acetic acid, aa proving 
decUively that its atomic weight is exactly 6*25. Norare (he 
cluimcters of acetic acid such us wouhl lead ua to believe that 
it contains more hydrogen than succinic uciil. It is as little 
liable to decampo«ition by heat, and yields less oil when dis- 
tilled in combination with a base, than succinic iicid. 

The moroxt/lic acid obtained by Klaproth, from a nalinO' 
exudation on tlie bark of the Morns alba," possesses ihc charac- 
ters of succinic acid so exiictly, that there seems no reason to 
hesitate about referring it tu that acid. From the experiments 
of M M. I^canu and Scrbut, it appears that suuiinic acid exbts 
■Iso in the turpentines that exude from iir-t 

Succinic acid being high priced is ofien adulterated, some- 
tiines with tartaric acid, sometimes with hisulpliate of |>otUKh, 
an<l sometimes witli uU ammoniac. If we hcAt a little of the 
pure acid in a platinum or silver spoon, it is vohitilixe<l witiiout 
residue ; if it contains tartaric acid a quantity of eharcuul will 
rem^n; if il contains Imulphate of potasli a salt will remain; 
and Sill ammoniac is detecleil by the ammoniucul smell emittcil 
when the t^iiccinic acid is mixed with lime. 



Nidiotsoii'i Jour, til- 189. t Ann. dc t'hiin. et ilc I'lij). x*k 3?S. 



SEcnoir xiT. — or benzoic acid. 


Benzoin, or Renjatniti, as it is Komptlmos called, is a kind ttMuy. 
Frr*)ii linm^lil from die Eawt Indit-s; obtaini'il, iici-onlin^ to 
[llr. Ilryninlcr, from ihc stynix bciiaoc, u tree whicli grim-sin 
iftJuiil of StiRuitrn. Tkis Hubstancc consisU piuily of n 
bch), dtfscribtH) as long a^o as 1608 by Blaise de 
enere, in liU Treatise on fire and salt, under tbc name of 
n t^bcnsoiHt because it was obtained by Hublimution ; but 
tunr denominated benzme acid. 
The usual method of obtaining this avid is to {itit a quan- Pnpuvon 
[tily of bensoiii, coiuiM-ly jMwdtrcd, into un earthen pot, to 
leorer the moutliof the pot witliaconeof thickpaperrand then 
I Id apply a very mtKierale wind IiimL llii- benzoic und in 
[inbUinttt, aiid iittadicf itnclf to th<; paper. This roetliod wiw 
Pledimu and difficult; it being hardly possible to prevent the 
from scorching the benzoin, and votatilizing Mtme empy- 
itic oil, which soils and injure;* tlie iicid sublimed. Neitman 
jioM'd moistening iho bunzoin with ulcoltol, and distilling It 
I a retort n-ith a low liKtt. The actd eomes over inimeiHutely 
' the iilcohul, [Kirtly in crystals and partly of tlie consistence 
rr.* (ieofTroy nscertained, in 1734, that this acid may 
'Wobtnim'd by digesting benzoin in hot water. A |>ortion ia 
taken up. which ia deposited in crystals as the water cools. 
Scheeie puldislied a diifefcnt mctliod in 1775; which being 
■■ler aiid more productive tltun any of tiio preceding, ia now 
prrftired. lliis proccM a as follows :f Upon four parts of 
■Balack«'<l lime pour twelve parts of nittcr, and after the cbuUi- 
doa is over add !)f{ parts more of water ; then put twelve ]uirt8 
of finidy [Miinded benxoin into a tinned pan ; pour upon it first 
^abeut six parts of the above milk of lime, mix them well together, 
thus flticce»ively add the rest of the mixture of lime and 
rr. If il he |>ouTed En all at once, the heincoin, instead of 
dng: witli it, u-ill coagulate;, and run togetlier into a mass. 
ab mixture ought to be boiled over a gentle fire for half lui 
r, witli constant .igitation; then take it from tlie fire, let it 
gd quiet for an hour, in order that it may settle ; pmir oif the 
iiatent limpid liquor into a ghuis vessel. Upon the remain- 
in the \mn jiour 06 parts of pure water ; boil them togetlier 
rhulf an hour, then take it from the fire, and let it settle ; luld 
Bupernatent li<itiur to die former ; pour upon the residuum 
mure nnitcr, boil it as aforesaid, and repeat the same 

• Keuman's Cbcinieiry. p. SM. f Schcele, i. Ili4. 




process oiioo tnorv. At last put itU the rcsiduunw upon ii filt«ri ' 
ftnd pour Lot water seveml times upon them. During this 
process, the calcareous earth combines willi the acid of henzoiiit 
and separates it from the resinous pnrticles of tJiis sulMtuiice. 
A small quantity of the renin is dissolved by the limc-w.iter, 
whence it acquires a yellow colour. All tliesc clear yellow 
leys and decoctions are to be mixed toj^etlier^ and boiled down 
to twenty-fnur piirtt, which ure tlu-n to he strained into aiiothef 
glass vessel. After they are ^own cold, niuriutic aciit is to be 
added, with eonslant stirring, till there be no farther prcopita- 
tion, or til! the mass taste a little sourish. The benaoic acid, 
which was before held in solution by the lime, precipitates in { 
tlie form of u fine powder. 

This process of Scheelo gives 1} of ben^toic acid from 10 
parts of bozoin, Tlie jirocess of Stohe is still more productive. 
By means of it we may obtain 1*8 of acid from 10 of bentoiu. 
But the expense of the process would in tliis country l>e too 
great It is as follows : Dissolve one port of beiiicoiu in threu 
parts of alcohol: put it into acnicible and neutralise it exactly 
uHihcarbonate of soda, dissolved in a mixture of eight parts water 
and three parts alcohol. Then add two parts more of water* 
and distil off the alcohol. Decant the aqueous liquiil reinitin- 
ing in tlte retort from ofT the reun which will have prcci|]ttated, 
and waslt this re^n with pure water. Decompose the benzoaia 
of mxta contained in this liquid by sulphuric acid.* 

Mr. Hatchetl has observed, that when benzoin is digested to 
sulphuric acid, a great quantity of heautifitlly crystallized hc»> 
zoic seid is sublimed. This process is liie simplest of all, and 
yields tlie acid in a state of puritj; ; it chums, therefore, the 
attention of manufactureni.f 

Itonxoic acid, thus obtained, is a fine light while elaatia 
body in fine needles, which is not brittle, but has rather a kind 
of ductilit}'. Its taste is ^wect, hot, and somewhat hitter. Its 
odour is slight, but peculiar an<l aromatic.^ It--* specific gravity ^ 
is D-6i>7.$ It hardly uflvct^ the infusion of violets, but it reddens ■ 
tliat of lumsol, cspeciulty when hoL|| < 

Heat vuliitilixcs tlits acid, and makes it give out a strong 

* Btrlinisrhcr Jaiirbiich dcr Pliurmacie, xxr. 1, 75> 

f IlaichttC'i Additional Experimeiita on Tannin. Phlt. Trsni. IMS. 

I Tiiia odour ii owing to a atnatl [iorlii>n of uomHtic oilahtcliadkercal 
the Hcid. It hna been obtained without any uncll by Oieae. See Rii 
Mag. xiv, 331. 

S IlHKnfnitx, Ann. <\e C3iim. xxviil. 11. 

g Morraau, Encyc MelliaiL Chiin. i. U. 


«iliiwr, whicli excitOB cougliing;. When exposed to ttie heat of 

. die blow-pipe in a silver tipoon, it meiw, b<-<^tnes as fluid m - 

I vaUT, and evaporalM without taking fire. It only burns when 

I hi (.-outact wtUi tlame, and lliun it leaves no re'siduum behind. 

Whwti tlirowii upon btiming conJs, it rises in a white smoke. 

Whru nllowrd to cool after being melted, it liardens, and a 

iTaiBati.'d crust forms on tit surfecc* When ilUtitled in cIo«c 

els, the greater part of it siiblimcH unaltfted, but some of 

b decomposed. This portion is converted almost entirely 

into oil and carburelted hydro^n gas. 

This acidic not altered by exi>o«ure to the air. Two hundred 
I pvtii of cold \t-ater dissolve I part of it ;■{- but 1 part of it dls- 
•olrn in 34^ parts of boiling water4 

II couhineB with Ikucs and fornix wits knnwii by the name 
^^iaaoaleJi. Tlic idkuline ben2oates are soluble in trater. So 
Eve the benxoatea of barytes, atrontiaii, and magnesia. ThoAe 
ralunina, yitria. and lime, are hut sparingly soluble. 1'hc only 
kuMnllic nUtA which fonn iruuiluble prei-ijii tales wlicn mixed 
jirith iMrnzoateof ammonia unithoso of iclhirium, mercury, and 
iofiron. Tellurium and mercury nre precipitated white; 
niBtige. BerzeliusJ has proposed benzoate of ammonia afl 
I r^tcellent agent for precipitating iron aiul separating it fram 
^Mhsr bodies with which it may be untied. From the experi- 
■ti of Hlsiiiger thA method uppeare to be a good one, pro- 
1 Uw iron be in the state of peroxide aJid the liquid contain 
lof acid. II 1 have been in the hahitof using it in iuialyse* 
aeretal years, and find it to answer the purpose perfectly. 
Concentrated sulphuric acid distolves hen^oie iicid without 
^bcM, or any other elmiige, except becoming somewhfkt brown : 
Iwbra watar is poured into tfa« aolution, the benzoic acid 
I ■epAniti-s, and coagulates on the surface without any alteration. f 
Nitric af id presents precLsely the wune phenomena, as docs ulso 
llbe mlphuTOua acid. Neitlier tlie muriatic, nor the phosphuriG 
LacUa, diwwlve it. Acetic acrid, wlwn hot, diwolves it prcciM'ly 
fa» water dom; but it erystaliixes agiun when the acid coub.** 
Alcohol dissolves it copiouidy, and lets it fall on the addition 
'«f wat«r.ft Boiling alcoliol lakes up its own weight-H One 


DiT. a 

* lichlcnaUnii. 

t Buchob, Ochlcn's Journal liir die Chemie, I'hysik anil Hineralogi^ 

I BacKolz, Sad. { A/hamllinsar.i. 171. || Ibid. lU. liS. 

1 UdmmiM B . ■■ n>id. tt Ibid. 

It WcoMl't Vcmndurtmn, p. 30S. 

Quit I. 


GCtw'IC Mill. 

iiuiulrwi part* of cuU) iibsoliitc alcohol iii*s«lve scarcely 56 paru 

of benzoic acid.* 

Tlib acid is sometiRie!) iiaed as a medicine, but much 1cm 

frecjueiilly than formerly. 

1 have shoHTi by exiH^rimeiiti, wltich I consider as decisive, 

tliiit tlie atomic weight of benzoic acid is la.^ Berzelius suk- 

jncted it to analyab, and obtained 

Hydrogen , . . 5"ltt 

Carbon . . . 74-41 

Oxygen . . 20-48 

100. t 

Tlieae proportions correspond witli 
atoms hydrogen 
15 atoms carbon 
a atoms oxygen 

Aim! m these atoms give the true atomic weight of tlie aeTif, 
there can be no doubt tliat tliey represent it'* constituents; 
though iti wlial way ihcsi- utomti arc amuiged wc have no 
accurate conception. 

Chemists had long suspected that an acid could be obtaincil 
from tallow, on account of the acrid nature of tlie fumes wliich 
it emits at a high temperature ; but it vun M. Orutzmacher 
who liriit treated of it particularly, in a dtss^'rUition /> Onsirnn 
Mftlulla, published in 1748.$ Mr. Rhadcs mentioned it in 
1 T&'i ; Si'giier published a dissertation on it in 1 754 ; and Crell 
examined its properties very fully in two dissertations publtskcd 
in the PhilosopbicAi TranKictions for I7A0 and 1762. It VILS 
called at first acid of fat, and afterwardii arbacic acid. 

Hut at the period when tlicse chemists made tlieir experi- 
ments, the characteristic properties of tlie different acids wer*? 
not sul&ciently known to enable tliem to di!>>tiiigimh acids from 
riieh otlicr witli precision. Thciiard exumintil the subject in 
1801, tried all the processes of Crell and Guyton Morvwm, and 
found tJinl the acids procured by lliem wen- either acetic or thi" 
acid employed in tlie process. I'henanl found, however, that 
a peculiar aciil was formed <luriiig the distillntion of tillow. To 
it lie consigned the uppelbtion of xcbeuiic and. The expertments 

• Buchob. Wrnxel'H VerwsiultschaCt, p. 308. 

t Pint Principlcf, U. 141. | AonaU of Philo«oph]r. t. lai. 



CROCOKIi: AOD, ■■■ 97 

of Aim ch«inut n-pre repeated in 1604 by Mr. ItiMP, who Otmt. 

•falninod >iimilnr n-siilu. and conlitmed all tlit? obflLTvatinn-t o{ ' 

ibeFrencU ()Uili>«plier.* Tlio sulijecl soon after was rct^unicd 
\>f Rerxelms, who in an eliiliurati! diwte rial ion, puMuIieil lit 
Id06, proved thai the si-huric acid of Thcniiixl is nothing else 
ikui benzoic acid contaminated with some unknown sub«iance 
iWrireH froRi the fat, which alten aome of ifa properties, but 
from which it nitty l>e fn-vd by propi'r priN:iitiliitnii.t Tlu'rv 
doM not tlivrffori' rxinl, a« far lu wv know al pnisunt, any ucid 
lu which tiio name of acbacic belongs. 


Thin acid was diwovcrcd by yt. Leopold Omolin while a^*t% 
pn!parin;r potaviutn hy Bninner't) proceas. of whidi an account 
hm liecn ^veo in the first vitbitac of thtH work (|i. •tOO). 

During tJie whoh^ pri>ci!«« of prt'purini; potaMHiuin, by cxpoKing 

cWrt-d crrnin of tartar to a strong heat in an iron holtlp, tlu-rp 

off a combustible gas, the nature of wliicb luis not been 

liiird. It K accompanied with a doiidy-loolcing body, 

whtefa ^rwlually Arnns a |rTny-coh>uTiil dcposite in the tube of 

appou^tiM. There is much of tlit« gray matter also in th« 

•abvtunw. which chokM up tlie iron tube of the appara- 

■nd abo in wlml unmvn over into the coppiT receiver, but 

i| with |»otBwiuni aiid duLrcnal. Thix gniy matter dlMotvfls 

great measure in tvalcr. and llie Aolution has a yellowish 

colour. If it be expiisi'd In Npontiineoii<i evapor.itton, 

diitinct kinili of crj'stiibi niakp their appeu ran et- in it. 'Iln* 

cotuist of loti}r nee<IU<« of an orange colour, ivhioii eun^iitt 

aocooic} acid united to potash ; the tiecond kind of t-ryvlids 

CMWbl <>r bicarl>oiiaIe of polaiOi, coloureil yellow probably by a 

itilp crooonic aciil. 

The neat wan wixmilwi from the croconnle of potiub by 

ting it (ri-»iu(V(l to a fine powdrr) for wmii- hoiir< tn 

litt« idciiliul, holding in soluiion a^ mncli ^•'Ulphurtc aciil nn 

ju>t suSicient to mlurate tlie potash containe<l in the salt, 

hulpliatcof poLiah remained umliasolved, while tliv croomic 

ill wa* taken up by the alcohol. 

TIiP light yvlluw aJeohnlic solution beiug evaporated on the ri»ivni.i. 

T bitlh, left the rroconic aciil in the Klut*' «f a tine lemon 

How o)>a(|ue crust, consisting of very fine irraimt. It diiMotves 

remlily in wnter ; the solution has a lemon yellow colour, and 

• OaU0n*f Jtmt. ia. 170. f AfhrnidUgar, L 170. 

It 8o CilM ou aCMunl of hs jellow colour rron »{«>»(, ervemt, nfffrM, 
It. H 


Chip. r. wlicn left to Kpontaitcous eraporarion, depo§!t«s small yellow- 
coloured gniiiis and needles, which undergo no altemtion when 
exposed to a heat of 212". Tliese cryxtal* have no Hmolt. 
They have a very acid and sharp Utstt! a» if tliey contained iron, 
snd they strongly redden Utmti^ paper. When licateil theyi 
leave a ehorconl which buriu away u-ithout leaving any reftidueJ 

Croconic acid when satnmti,H) with potasli xhodtm out into tbs I 
same needles of eroeouute of potash from whieli it was origi- < 
nolly procured. Crocoiuto of potash is precipitated light 
yellow by barytcs miter and muriate of Itarytex, and tlip preci- 
pitate dissolves readily in muriatic acid. When the solution 
is mixed with muriate of lime, and allowed to standi for 'i^fl 
honni, itmall li^lit yellow grains of croconate of lime are depo- 
sited which are soluble in n'atcr. 

Sulphate of mujpicsia, alum, bimuriate of titanium, muriate 
of chromium, muriate of uranium, muriate of manganese, 
muriate of cobalt, muriate of nickel, and oulpliate of xinc, when 
mixed with croconate of polasli occasion no precipitate. Itimu- 
riatc of antimony and binitmte of bismuth oeca<ion leinon 
yellow precipitates, redissolved by an addition of the ueid salts. 
Protomuriate of tin throws down an oranjje yellow precipitate 
from croconate of pota»ili. Acetate of lead throws down lemon 
yellow flocks again dissolved by the addition of nitric acid. The 
solution of culphate of iron is rendered Iirciwnii^h yellow when 
mixed with croconate of pota»h, and permnriiite of iron by the 
same mutturo becomes black or gntyish-red if in very minute 

Siilpliaie of copper forms with it a green solution, antl after 
some houra depoMtcs »im»ll orange er^vsiiils of croconate of 
copper. Nitrate of mercury behaves like acetate of lead, 
except tliat the precipitate is not so easily diviolved by nitric 
acid. With nitrate of silver croconate of potash forms an aurora 
red precipitate, which dissolves in nitric acid witli the evolution 
of a little gas, and the solution is eolourleiR«. 

Croconate of pntasih dissolve* in nitric acid with rffervescenc 
But the itcid is not destroyed, it is only idtered in its qualities; 
for on evaporation no saltpetre is obtained, but yellow crj'Btala, 
difTerinfr in some respects from croconate of potash. Clitorine 
seems to act in the same way a-t nitric acid. Hut ioilinc does 
not seem capable of nltering its properties. 

The croconate of potash was subjected towuUysts by GmeUn, 
iiud found a compound of 






1 atom croconic add 

1 atom potash 

2 Btanu water 






! Wbile his analyvui of Utc aviil by lieaUiiig it will) oxide of 
nipper gnvc 

Carbon . . . 2»>e0 

Oxygen . . . 25-64 

Hydrogen . . . 0'\& 

f Tills oorresponds nearly with 

I atoni hydrogen . . 0-125 

6 atonu cariMHi . . 3*75 

4 alopwi ox^'Ki'Ji . . 4 


ISo tW according to tliis analysis the atomic wei^^lit of croconio 
id u 7*873. I tliiiik it prvlxiMe from Gmolin's experiments, 
at crooonie add ooniaiiM no hydm)rcn, but is a compound of 
i otuuw carbon and 4 of oxygv'n, lutd that its atomic weight is 
^'75. I iUt«mpt«d to determine the atomic weig^hC of this and 
■" double dfcom position, But the experiment was upon too 
a scale to be decisive. So far as it went it was &vour- 
to the notion that the atomic weight is 7*75.* 

semoN XVI, ^ — 'OF oallic acid. 
There ia an vxcrracence, known by the name of nutgall-, hiu^t. 
rhich gmwH on M>ine species of aides. This substance eorilaiiis 
, [leeiili^U iin<l, called from that cdrcumstance ijallie acid : tlie 
pr<^eTties of which were firM examined with iittentiiai by die 
iLtMODeni of the Academy of Dijon, and tJie result of tlieir 
ricneuU was published bi 1777,iu the tliird volume of their 
pmi'Hls of t'licmistry.f In these experiment*, however, they 
Dpkiyed the infusion of galls, in which the ncid is combined 
ith tannin. It was rejiervod for f>cheele bo obtain it nearly in 
> ttate of purity. 
X. He observed In an infusion of gulla made with eold water 
Jimeiit, wlitdi proved on examination to have a crystalline 
anil an acid taste. Ity letting an infusion of gulls remaiu 
. long time exposed to tlie air, and removing now and then the 
nooldy skin which formed on itit surface, a large quantity of 

• 8m (hnrihi'i paper in Poggendorf*! Aiiiulen, \i. 31. 
t Vol. lii p. 44MI. 



**^'* this si'diment was ohtainfd ; which being rdiileorntcd with col 
water, rt'Hiwnlvod in hot waU-r, filtrated luiil ex-aporated rery 
slowly, yiflileil nti iu-id «iU in crystaU as fine as '»nd.* 

Dcyciix has proposed a inticli speedier method of ohtnining 
gullic jieid if but it docs not succeed without n f;ood <)eal of 
precaution. It cnnsista in fixposiii^ |)ounded nut^pills in a lar|re 
glass retort to a heat cautiously and slowly raised. A number 
of brilliiiiit white crystalline plates are sublimed, wliich possess 
all the pro]>(>rties of gallic acid, ('are rnu!>t he t-iken not to 
apply too ffrcat a heat, and to stop the proec** hefore any oil 
beijins to come over, othcrn'isc the crystids will be Tcdissolved, 
and the whole l.thoiir lost. 

M. Braconnol lias miifrived anotlier process, which ap])earA 
to l>e both more economical, and more elTectunI than either of 
the prcct'dinK ones. It is merely an improvement of the pro- 
cess of .Scheele, and is us follows : 

Two hundred and fifty grammes of nutpill» were infii*ed for 
four days in a littre of water (nearly half a pound avoirdupois 
of nut|^nlls in a wine quart of wafer), taking care to agitate the 
mlvture from time to time. The whole was then ."queezed 
Ihroiigli a cloth, and the liquid pasM'd through a filter. It WM 
then left in an opi-n gliwa deeauter from Jidy 'J'J t«t .*^pteml)cr 
SS, or two months. Its bulk had not sensibly diminished ; but 
it hud deposited a considerable quantity of crystals of gallic acid.' 
TliCse were separated by squeezing the liquid tiinmgbaclotli. 
The liquid, when evaporated to iJie coiiKisti-iicc of a synip, 
deposited an additional quantity of crystals which were separ- 
ated in the same manner. The residual matter of the nutgalls 
from which the infutiiun had been procured, when moHteneil 
with water and left to spontaneous fermentation, yieldeil an 
additional crop of crystals when treiitc<l with hot water. So 
tliat nutgalls when properly treated may be made lo yield the 
fifth part of iheir weight of gidlic add. 

IJy tlii'oe different processes M. Rraconnot obtained 62 
grummet) of gallic acid, still coloured and mixed witli nit iiiso-< 
lublc powder. It was boiled with I R cubic inches of water, 
■nd filtered while bailing hot. The liquid on cooling deposited 
40 grammes of crysiahi of gallic aci<! of a yellowisli-wliile colour.' 
The mother water was brown, and when properly evapomi^d 

• tJuckKuliii Tn>n». 176(1.— The crjxials olxsinei) by this method nlwajrt.'' 
coiWain'^ portion o( tannin, nnit ate ot > brow ii culuur. 

f UHBk-ltiod utta in liicc J»co*cr«J by iichecic ; but Dcji-ux reptatcal it, 
uiiiMfed out the proper (jTcraution*. KmOvII'* Annuls, i.^it. Eiig.TmiM. 





yieJilerf 10 giammw more of crystallized gallic arid, darker 
cokMUvd tluut the first cryslak. To free these cryHUlM entirely 
atourin^ ruulti^r, tLcy were mixed with oiuhi times their 
of wuttT, ant) about tlie fifth of their wi'ight of ivory- 
lUid the mixture was kept for »buul » quarter of an Iiour 
: the tmiljji); t«inperalure. It vma thon filti-re4l u'liite hot ; on 
jling it ivncr^'twl into a iniws of [K-rfetily white t-rystjilit of 
acid, which were M'|>»ralvd from the liquid by [>rMaiure 
I ft rlutb. ■ 

Osllic acid obtaiued by tlm la»t proceiM i« tivarly pure, and 
nuy Itc freed from tlic Umniu whicli still adheres (u it by 

When thus obtained it i» mow white, and is in unall eryittals 
' B foliated fraciun!. 'I'lu- i^luipc of the crynlals i<i iiHiiiilly 
rectangubir priiim, or a tlut rociiuigiiLir i>[iiU- like iiiicii. 
Brooke descril>cs i( as a doubly oblique prLsin.f Bui it iit 
rideut from bis own descriptions, ilmt liic Mn M, M' of his 
> art) inclined to each other at ligLt tingles, ho tliat the 
maat t>e rectangular and imt oblique. 
Tbe lastv of Hubliinctl gallic iiciil is bitter, and it leaves in 
moatli on imprunsioii of Hwectness. It does not rcddt-u 
?T stoned blue with litmus. The ucid obtuutcd by Bra- 
DBnot'a process has a tiour taste. 
It u aoluble in 1( porta of boiling water, and in 12 parte of 
ild water. When this noIuIiou Is heated, tlic arid uixlergaeH 
nrry Kpcedy dccompOHitiun. Alcohol diKioIves one-fuurtli 
weight of this arid at tb« temperature of tlie atmosphere, 
ben Ixiiling-hut, it dissolves a qiiantily i^qwil to it^ uuii 
jlit. It Unulublealsoiii ether. The solutiuusarecoluurk'M. 
Uallie add in crystals is nut altered by exposure to tlic air. 
Iter oiygeu gun, the simple oumbuti tildes, nor luoti.*, tieem 
re any particuhir action on iL When tJie solution of tliis 
iu water is ex{K)Ke<l to tlie air, it giadunlly acquiresa bronn 
and the acid Im deslioyed; tbe aurfuce of tlie liquid 
ecoDiing covered with moiitdinesi. 
It combines witlt alkaline bodies, separating the carbonic 
id if tlicy were in the; ntat*^ of tarlioiiatee. The compounds 
[formed have received the name of gallatea; but hitherto Itave 
tly beea examined. Indeed tliey may ho siid not to exist. 
For boMB, M has been shouii by Mr. .Sertiirner, have tliepro- 
Fperty of acting on gallic acid and speedily de composing it.( 

• Aaa, lie Cfaioi. ct Je i'hyi. ix. ltd. t Aanula uf I'liilooo^jb}, vl. I Itf. 
t 8d>— i agtt 'i JovrasI, iv. 410. 




«"»k <• Whcu nitric acid U poured on tliw acid, » brbJc efferrescence 
tiikus ptacv, heat is cvolvwl, mid llie ncid is duutilvi-d very nptdly. 
The §olution litis a red colour, and when conci'ntrutwl, cryxuia 
of oxalic acid arc deposited, aiid a wliitv inttolitblu muUer alto 
appears. ■ 

To a solution of 13' 19 gi^na of bicarbonate of potash (coa- V 
taiautg H |rraiii!i of potasli),! added H gnu us of crystallized and 
anliydruus gallic aciiL There was u strong efTervesccnce which 
ace»mpiuiicd tliu solution of the acid. But after tlic wliol« 
gii;i<l was dlsHolvcd the liquid still retained itn alkaline taste, and fl 
rendered cudbear paper violet as alkalies do. Even die addi- 
tion of S more graioH of the aci<l did not destroy the alkaline 
nature of the liquid. The solution wag at first colourlew; but 
after two da^'s it bccuine ^cen, and this colour ^niduuLly deop* 
ened an much, ibat the liquid became opaque and looked like 
ink. When evaporated to dryness it left n substance like pitch, 
which dissolved with effervescence in nitric acid, and the solu- 
tion was brown. It is obvimis from this that the acid was 
decomposed by tlie action of the potasli on it. Accordin^y 
till! solution of i^allate of pot;isli in water does not exhibit the 
cliatncteristic properties of gallic acid, when mixed witli a solu- 
tion of sulphate of iron. h 

The characteristic ])roperty of gallic acid is to strike a dcep^ 
blue witli the salts of iron, particularly tlic sulphate. The bamin, 
whiohiaanother constituent of nutgalls, possesses the rame prt^ 
perty ; but it has an exceedingly astringent ta»tK, atnl tlirows 
down a bulT coloured preeipilate when drupt into an utiueous 
solution of glue. Tannin it»elf «eenu( to poHscss acid qualities ; 
but as it has never been obtained exempt fix>m gallic acid, it is 
possible tliat it may owe tliese qualities to ibe presence of tbaCM 
substance. V 

tcompMiiun. Beraeliiis subjected the gallate of lea<l to analysis, and found 
Its consljtueuu tu be* 

Gallic ai-id . . d-047 

Oxido of lead . . 14 
TliM gives UH fi for its atomic wcighL The acJd itself, tub- 



jected to analysis, yielded 


* Aanol* ol VUUoMphy, v. 176. 



sjKinds with 
3 atooia hydrogen 
6 utotiM carbon 
3 uUHiu oxygen 





j4BM Bfeomic proportiotis give 7*873 fur tlie atomic wciglit of 
guSe acid. 'Ciiis U 0-1*2^, or uii atom of liyilrogoii le&H Umn 
vhat TOHilU from Uie unalyKii^ uf galliiU^ uf lead I iuii ilis{>os4Hl 
to prefer Uiui Uut luialysiit iw likely to bo monloorrvct; tocoii- 
nder the itom of gnllTc acid to wcigit 8, unJ ttn constituents 

4 atoms Iiydrogen . . O'd 
6 utouu carbon . 4*3 

3 utoms oxy^ttQ . . 3 


DoberetJier informs us, tliat whvn KW parts of gullic add 

i Xmalved in ammonia are left iu contact will) oxygen gas. they 

I abiiOTb 3t(-09 {larts of tbat gaa, and are converted into uimin, 

l(N) parts of gallic tkcid, uccorxling to tlic above etttimate, coa- 

tial of 

Hydrogen . . •<"->> 

Carbon . . 66-25 

Oxygen . . 37-6 


Now 38-09 of oxygen, jji order to form water, must combine 
witli -l'?!! of hydrogen. There will remtun 1-G9 of Lydrogcn. 
So tbut uluiin ought to be a compound of 

Hydrogen . . 1-49 

Ctabon . . 60'26 

Oxygen . . 37 "5 

ii very little more than iui atom of liydrogcti, to that 

ulxniii wuuhl appear from Doberoiner's observation to be a conv> 

pound of 

I atom hydrogen, 
6 atoin» carbon, 
3 utonu oxygen.* 

* Cilbert'e Aaiulcn, Ixxiv. (lOu 



FJldffic Acid. 

I( mity t>c |>roi>cr to rtutictr hnt » !>utHlaiice wbicU Rracon- 
not has cUiitinguislird by this vory alieurd iiumi* (the l-'reudi 
word ffalte iiiverlcd). It possesses imperfectly ncM propertint, 
uiiii was extraetod from niil^tls at the siime time with gailic 
Dcid. It woiih) Hppi-ar from u ii»tt- of Chevreul tliat it had been 
already detected by him, »nd scvcnd of il» projieriiea described 
til ihciiTticte tannin, puldished in the ehcmind purt of the Kiicy- 
dop^ie Mcthodiquc, iti 1815. liut he hadnot given itiinumrT 
aiid does not sevm to have been aware of its acid propertit-s.* 

F.llagic attd lints oblained by Bntcomiot by filtering the 
Holiilioii uf ^kUic uviil ob[iiiiit!(I fniiii tJie crystiilfi u'lucti luid 
fonned Kpi>ntiincoiisly in the infusion df nntgalbt. A powder 
rcinuitied upon the filter, wliich WiW elliigie arid mixed with a 
certain quantity of giillate of IJme. To free it from this salt 
it was Ireiilcd with a dilute solution of pot^tsh, which di^solvi-d 
the acid with the evolution of ii conitiderublc quantity of licaL 
1'lie solution had an intense yellow colour, uiid gnuiually let 
felt a pretty considerable quantity of pearl' ■coloured ])OH'der, 
whidi was separated by the filler and deeonipused by dilute 
muriittiv ad<l. 

The ellagic acid thus obtained itt a white powder with a slight 
oliadc of buff. It is tasteless, and is not sensibly soluble ereil 
in boiling water. It <loes nut decompose the alkaline carbonates 
even when aMixted by hi-at Hut it unitCK witli cauHtic mkIu 
and pota»h, and dejilroyi their alludine cliariieterN. These silts 
are insoluble in wuter. 13ut tliey become soluble if u little 
potash or soda be previously diNwIvcd in tlmt liquid. The 
solution lias a vet)- deep buff colour. The ellaji^te of lunmouia 
is likewise insoluble, and does not become soluble even when 
an fxcKTB* of ammonia is added. When this add is agitated in 
lime wuU-r it He^ninitcs the time from the liijuid. Nitric acid 
does not seem to net upon it at first, but if we eontirnie the 
digestion it gradually ussuines a blooil-reil colour. 

Ellagic acid does not combine with iodine. Wlien heated 
it does not melt, but bums away with a sort of sciulilkition, 
wiihuiil entiiiin{( llame. When distilled it leaves ehuriiial and 
prwiuccs u ycllnw vapour, whidi condenses int«» traiispareut 
crystals of a line greeui^h-yellow colour. This sublimate is 
tasteless and iuixduble in water, alcohol, and ether; bu(itdU> 
soli'es readily in A Rolulion of potasJi, and coramunicutes a 



* Aao. lie Cliiin. ct Je I'lijit. is. SW. 


jwhr colour. So tluit these crystals possess the same cltane- 
Uei OS tli<> ftcid imwdcr itaolf,* 


Dl*. IL 

Thi* vcj^'tablf sulMtance to wlticli I jjavo liio iiaine of u/mijt, aww)-- 
ms first tiulicc>(l by KlaprotU in 1604, who fuurul il inumuttrr 
vkich bad exuded from tlie i>ark of tbv r/m. It wii» notiMrd by 
BtndJiu ill 1610, in hU cx{)«^rim<-iil.s on tliv bitrk of ihc piiii;, 
•ndoa J«i«ti)t'H bark.t In tb<t bc^iiiiiiii<r of the year 1813 I 
inbUsbcd a set of rxperiinenta on tliis substance.^ About the 
■nkc time, a fimilnr set of experiments leading to itf arly tlu- stunt.- 
etaeluaioiis was maile by Mr. Sinitliaon.j In ll^DO, M. I'oly- 
im Boulluy pul>li.'ilieil a set of experimentK on it, in which he 
Auwed tlial it posMessed tJte pni|>rrtit!S of un ucid, und thore- 
fiira K*ve it tlu^ itiunt* of ulmic uritl.\\ 

L'lnic acid apfH'tuH to be a vegetable substance of very grent 
importance. It nut only cxbtft ready formed in bark, but it 
■dtM its appeamiiee in a great variety of vegetuble deoompa- 
litions. M- P. Ooullay Iiai found that wlien the ^agai of 
impeo, diftM>tved in water, in lieated with an alkaline ley, it ia 
mavertod into ulmic »ci<L It cotKtiliitc» thu essentia] ingre- 
iliciil of fieat and of umlier. It wouhl up])ear also to be an 
■dinimblc manurv, or rather to vunstitiite what is usually 
odled vrgrtabU manure, 
Ulmic acid when obtained from the exudation of the elm by rnipnUci. 
olviit^ the exudation in water, and precipilaiiiig the ulmic 
ad by an acid, which saturates ilie pouvth with whii-h it was 
rnin I li nation, consists uf dark hrowu Qocks almost de*titule 
uutc and Hinelb It diswiive« in small quantity in water and 
IfoboL The solutions have a brown colour, but no taste. 
U called musft-wuter is merely water in wliidi thix acid 
vived. M'ben heated, it smgIU and catches fire, hut does 
: melL 

It nimhinra witli the dilferent Iimscs which it neutralizes, and 
fonnit compounds aiialof^oiut to Halbt, luid whidi therefore may 
tw allied uiinata. Tlic iiolution of ulmnlr iifpn<iifh% in water 
^B a dark brown colour. Sulpliale of iron pteci{i)litte» it hrvwR 
' MNnetiines tjrrnt. All the acicLs throw doiin the ulmic acid 
mturaiiug tin- jioiash. Nitrate uf milver throwtt it <]own of 

• Aan. de t^him. «t Ae V^j*. ix. p. 187. 

) Aiuial* or rhilcaotihf, i its. 
i I Ann. (Ic Ctaia. m dc Phyn. xUii. VT3- 
; i TU> hIi eoiutiCDtci the usual cxuiluion from the ctoi. 

f AriunUlln^-Hr. iii. 347. 
$ PhiL TfRiM. ItfIS, p. M. 


a*K t a beautiful red. Nitrate of lead and sulphate of copper give 
precipitates approaching to black. 

M. P. Boulky analyzed some of the ulmates, and found their 
composition as follows : 

I. Ubnate of aUfoer. 
Ulmicacid , . . 36-87 
Oxide of silver . . 14-75 

2. Ulnmieofkad. 
Ubnic acid . . . SS-ia 
Oxide of lead ... 14 

3. Ubmate qf copper. 
Ulmic add . . . 42-61 
Oxide of copper . . 5 
These analyses give different numbers for the atomic weight cf 
ulmic at^d. Boullay considers the analysis of ulmate of cc^per 
as the most exact. According to it the atomic weight of ulmic 
acid is 42-61. 
c«ap«moa. He subjected ulmic acid itself to anal^is, by heating it witk 
oxide of c(q)per, and obtained for the constituents 
Hydrogen . , , 4-8 

Carbon .... 56-7 
Oxygen .... 38-5 

These numbers are very nearly in the ratios of 

1 atom hydrogen , . 0-125 

2 atoms carbon . . 1-5 
1 atom oxygen . . 1 


If we multiply these atoms by 16 we obtun 

16 atoms hydrt^en ... 2 
32 atoms carbon . . .24 

16 atoms oxygen . . .16 


This gives us 42 for the atomic weight of ulmic acid, a number 
which approaches sufficientiy near the number derived &om tiie 
analysis of ulmate of copper, to give some probability to its 
being not &r from the truth. 

The reader will observe tiiat the ratios between the atoms 
of carbon, hydrt^en, and oxygen, which constitute gallic acid, 
are the same as those of ulmic acid. They are both resolvable 


I atom of water and 2 atoms of carbon. But the atoms in 
nic acid ure tt4, wbiln tlioAe in ^lic add ore only 12. Hi^^ncv ' 
atomic wc^ht of ulmic acid in 5^ times greater tlian tliat 
: gallic acid. 

Dobcrcincr unnotuicvd that when gallate of ammonia is cx- 
poawt to the air it b converted into ulnuitc of anununia. But 
tkk ia not likely, the acid becomes dark coloun-d, but I lind 
the atomic we%ht h scarcely altered.* 



The Crameria triandra is a plant which ve^tates in Pern, nwoiT, 
Ac nK>t of which Ls rcuuirkiilile fur iu astringent properties, 
id ia Mid to be employed by the natit-es of the cuuntry where 
grows, M a m«linnr of ^eat eflioicy in ciiM'S of atonic bw- 
irrh^es. It is said to be brought to I>undoii tn great qiian- 
for the puq)ose of ^ving the requisite colour to artificial 
itatioiis of wine. Tbiit root attracted tlie attention of M. 
Vsdiicr, apotliectu-)' »t Genera, who detect^ in itn new acid, 
yiiich he baa distinguished by the name of crammc acid. 
He obtained this acid in the following manner: 

The root (particularly the hark) was boiled with waU>r,afld 
by this means a strong decoction waa obtained, whicli hud an 
astringent taate, anil iMruck n black with sulphate of iron. To 
free it from tlie tannin, which it was presumed to contain, the 
deooctitm from an oiuice of the root was mixed with a stoliitlon 
of 48 grains of gehitiue, which occasiotK-<l u reddiKh brown 
depoaite weighing 1'26 grains. To depriro tlic decoction of its 
ralouring matter and of iu gallic acid, which it still contained, 
200 grwns of Milphate of iron were added for every ounce of 
the root employed in niukiii}r tlie decoction, and tlie liquid U 
Ifaen diluted with 7 or 8 pounds at water, and filtered. By this 
IS it is rendered nearly colourless. It h then boiled nntb 
nlficient qu.'inlity of chalk tn decompose all the sulphate of 
which it litill relaitix, an<l to wturate the eroroeric acid 
nt in It. The wliole liquid is now |>a»sed through the 
iter and coneentrated to the requisite degree. The liiiio !-■< to 
thrown donii with carbonate of potash, and the cmiuerute of 
putaxh in precipitated by acetate of lead. The cnimcmte of 
lead being profH<rly wiuiih^'d, is ileronipu<<ed by a current of sul- 
pkaretted hydrogen gas. The liquid btring filtered and eva- 
porated to the requisite cousistcttcy, nothing remains but a 
lution of cnuncric acid in water. 

• See p. 103. 



Cramcncaoidtfausobtain^hasa&trongacid tastp, and leavct'^ 
upon tliL- itiiigii« n peculiar styptic sensadoi]. It cannot be 
nuulc to cry«t<i)lu«. It lnn no action upon tin: .talb of Ume aitd _ 
magncsiii, but it (l<-cumpoecs <tll tho stilit of liiiryti-n and strott-fl 
tifui, forminjE; tn-o salts n-itli rach, u Htipcr>aiU which i^ so!iiblo» 
and a subsatt wUicU is insoluble in water. Craineratc of barjlcs 
is not decompo§e<l nor altered by sulphuric add. So that cnknto-l 
ric aoid hitR a atruti|^r affinity for barylcs tlian sulphuric iidd4 
has. It liirovvn itnwu the salts of lead white. Cramcrulc ^iti 
potash, sod.-!, aiiimonia, lime, and bnryteH, throw down tliv sdta^ 
of iron yellow. It has no wuKible action oit tliv oilier mvtalUne j 

Ciamerate of potanh cryntallizcs in ox-sided prisms. 

Cramerale <>f hchU furinfl large crystals, luivuig tlic 
sliape, utiil elflore^citig wlicn oxpoHcd t4) the air. 

Cnuncnite uf uininoiiia yichl^ ft^athc^-«haped crystals. 

All iJiCM.- Htttl« urc- iiiaolublv in alcohol. 'I'bey have little^ 
iMte, and when tb-own iitto a «alt of buryle* tWy occasioD 

Such utv the properties of cntmcric acid, pointed out by M< j 
Peschier. They will require to be verified, and 1 suspect rcH^j 
tifictj ta st-verul points, before the peculiiu'ityof tliis acid be fiiUjr 
dcinonslrulcd, and ii« ciianicti^rs iiccunttcly ilcteiiniiied.' 




Mr. DcHchatnps, junior, an apotliecary in Lyons, publia 
a method of cxlracLnijf iVom yellow Peruvian bark a iieculiBT 
salt, to which the phjnicians of Lyons ascribed the febrifiigv 
properties of that bark. Mis process was very nimple ; tJie borit 
was maceratul in cold Witt4-r, and the infusion cuncenlniled by 
evaporation. U w<v llicn wl aside for sunit- time in an open 
vessel. 'I'he crystals of the salt gradually formed luid sejiaruttidtfl 
and tliey wen- purilied by repealed cr^T^tallixutions. From iOO 
piirt* of ibe bark about 7 pai Is of tlttse crystals were obtained.^ 

This salt was examinetl by M. \'auquvliii, who proved it to 
be rompoMcd of lime united to it peculiar acid, to whivh he gave 
the name hinict borrowed from the teim r/uin^wiAu, applied by 
the French writere to tliv baik from which the salt was »• 

Descluunps' salt then is kinatt oflimt, M. \'auquelin separ- 
ated the lifiic from the kinic acid by means of oxalic acid. 

Sec Jwur. ile I'hormatiH-, vl. 34. f Auu. de Clitui. xltriil. liM. 




Dl«. IL 

IfM. Pe1Ieti«r and Caventxm obtained it ftoin the alcoholic 
tBicturc of K<^y cindiAnn by *li«tillit^ off the alroh<t1 nftvr 
brinfT nililtnl a «ixtti [wirt of itt w4-i^tit h( water, 'llie liquid 
tenauniiitc in the rrtinl wiit frvvl from tbo fiiHy malliT and the 
kcmnt reflin which Imd sqiarnlod ditriii<; iho dtttiltiilinti, and 
■w boileil for some time with n ff^rvat exevst of magrii-niit nilil 
■Imo filti-rcd. BeiDg ernporated nearly to dryneM, it asNiimn) 
A» ■ppeunuKc of a mnfrimi, which h^iii)>; dtirosted in alooliol 
Itft S wbite salt consiitioje; of kuialc of itiat;ii<^siii. 1 1 wiu dc- 
(OBtpohed by lime, and liie kinate of lime in ibt turn dccompo>M»l 
Vj nMHU of oxalic acid, and the kiiiic acid was obtained in 
mmoU by the reqiiisiie concentration.* 

Kinic ncicl t)n» obt-)in<-d, when pure, luM a stmng acid taste iiipmieh 
vii)u>ni nny liiit«-nii-vt. 'iltc cry*Ud4 hfivf A gtm'l deal of 
n-ocmldaiK-i- to ilii»<' of tnrtnric acid. Thoy arc transiwircnt 
ni) caloiirl(t«i( wiil d<-ttitiit« of sumH. 'nteir spcciAe ^mvity 
a l-(W7. They are soluble in alcohol. At the temperature 
iif 4rt* they diwolre in 2 S limes their weight of water. When 
Imilivl with starch diiwolvwl in water, they cimvert it int4i su^jnr. 
DiiUtilcd with alcohol, they form an elhi^ similar U> th» Inr- 
tu^ rlber of Thenanl. Nitric acid eoiiTertit tlib> iicid to the 
oxalic. Sulphuric acid decotnpOMS it, luid give* it at first u 
^fine grepn colour.f 

^b It contbincM with ba»e«, and forms a genii<t of salts called 

^■AtMifrJ; All these salts iire v>luble in water. Hencv it liappi'ii** 

^nutt kinic acid 'n not capble of throwing down any of ihc biiiscif 

when dropped into sUine Holulioni*. In tliu respect it retwmbleH 

acrtir arid. 

Kiiiatcfi of lime, baryte*, and nipper, were analysed by MM. cioraniiaa. 
iiry and I'ltswn, who found tliem compo«ed tu follows: 

I, Kinale t^lime. 
Kioic acid . . SS-OGO 
Lime . . . 0-5 

2. Kinate ofbart/tft. 
Kiltie acid . . 'JS-Otfl 
Barytew . »-5 

3. Kinate of copper, 
KtHtcacid . 'J3'46 
Oxide of copper . 5 

numbers make it probnhU' lluit (he atomic weight of 

• Anil. Je CWtn, cl il« I'hju. it. 3(M. 

t llmrr «iul PliMon i Ann. ik Chin, el Uc Pb)-«. xli. 9ii6. 


c><*p. L ktnic add is about 23. The same chemists sabjected die add 
to au analysis, and found the constitoents to be 

Hydrogen . . . 5-560 

Carbon .... 34-115 
Oxygen .... 60-325 

Kow the smallest number of atoms that agrees with these pn^ 
portions and with the atomic weight derived from die analysit 
of the salts is, 

10 atoms hydrogen . . {"SS 

10 atoms carbon . . 7*50 

15 atoms oxygen . ' . 15 


But this gives the atomic weight too high. If we abstmet an 
atom of carbon, and consider the acid as composed of 

10 atoms hydrogen . . 1-25 

9 atoms carbon . . 6*75 

15 atoms oxygen . . 15 


we obtain 33 for the atomic weight. This, therefore, is die 
constitution of this acid that agre^ best with the analytical 
results of Henry and Plisson. 


mrtsrj. This acid was discovered by MM. Pelletier and Caventoa 

about the year 1820. It is obtained by distilling kinic add. 
When heat is applied to this acid in a retort it swells iqt, 
blackens, and gives out a white acrid smoke. There passes 
over into the receiver a brown, oily, and very add liquid, while 
some crystals make their appearance in the neck of the retorts 
These crystals were redissolved, and the liquor filtered through 
moistened cotton to retain the oil. This liquid being slowly 
evaporated, yielded crystals of pyrokinic acid. 

PnpoUo. Pyrokinic acid crystallizes in tufts composed of divei^ng 
needles. It u at first brown, but by repeated crystallizations be- 
comes colourless. Its taste isacid,Bnd it isdestituteofsmelL Itis 
very soluble both in water and alcohol. It forms soluble salts 
witii potash, soda, ammonia, barytes, and lime. It occauons a 

• Henry and Plisson ; Ann- de Chim. et de Phjs. xli. 387. 


Vtt^t pi«cipitat« in acetate of lesul uirf nitrate nf »i)v-«r. Its '^'^ *■ 

(jiafacteristic property is that it jirecipiuteii the p«ii!ul|)l)atc of 

nm of n iH'juitiful frroon colour. So drliaitP a tpst U it of iron, 
that it nntutneit « frrccn colour wlicn combined wiih lime or 
tanftcfi, contaiciipg traces of tliat metaL It is neither afTectecl ^| 
by aoluticHis of glue nor of tartar emetic* ^| 


^ft Tim acid ezbts in opium, prolwbly in combiitation witli ■■mm]'. 
^boq^ne. It wim dtscovcrcd by M. Sertiirnpr, and call«d by 
^ iimMrconic acid. (lom the Greek VQT<liir.>n^, (I p<ippif. Varion* 
■odpH of extracting tlii.i aciil from (lie ii)fii!>i(in of opium luivc 
bwn propmteil ; but none «f thvin kcciiw t« be very |;oo<l. Th« 
MlowioK proctrsa*, which was contrived by Robiquet, yields 
BMOBie acid, but we do not succeed by it in obtaining the 
vfaole of that acid wliicb exists in the liquid. H 

Bcril the infusion of opium with rather a greater quantity of ^M 
napieaia than ht >iufiicirnt to precipitate the whole of the inur- ^M 
pbinr. I)ige«t tlie precipitate in alcohol till tlie whole of tlic ^M 
■oqtluiM ia diMoketL There remains behind » quantity of ^^ 
■agneaia united viih meconic acid. Sulphuric acid dissolves 
ikM matter, and forms witli it a brown coloured iolution. 
Muriate of bar)-tes being drop! into the solution a precipitate 
&1U, comiiiliug of Kulpbute of b»r)'te«, aiHl mcconateuf burylcit 
^^riightty tin;;i-<l red. Weak sulphuric acid being long digested 
^■Vpoa this precipitate, decompoaes the mecoiiate ; the meconic 
aeidiliaaolresinihe water, while the Kulphnte of baryteM remains 
Th« water Wing (■vaiv)rnted, iiUow* the niei-onic jicid 
ilcpmftC in the form of brown crystatii. In lhi»i Hijite it is 
itominated with a colouring matter which renders it much 
•oliibla in water tlian when pure, an^l enuKOM llie mecnnato 
'aufftwaiaand of b«ryte« to prmpUaU-; for when tlicMemttit 
pare, they are soluble in water. Tlicse brown crj'stnls nn> 
be dried at a low temperature, and then to be exposed to a 
ber temperature, but one not tiufficiently bigfa to dceompoM 
colouring mutter. The mt'cnnic aci<l sublimes, and is depiv 
on tlie up]H-r part of the retort 
A still easier process for proenring this acid has been recoin- 
Kml4*d bv Dr. Mare, Drop acetate of lead into the aqtieons 
■fiiaion of opium; mccnnate of lead precipitates: wash this 
pradpitstc, mix it with water, lUtd pass a currentof sulphuretted 

• Aan. lie aiim. ct <!« Phja. xv. Ul. 



Chip. I. 


hydrogen through it The lead is separated, and the meconic 
acid dissolves in the water. Filter the solution, and evaporate 
till the meconic acid falls in crystals. 

Meconic acid thus obtained is white, and is usually crystal- 
lized in long needles, or square plates, though sometimes it 
aSecta other forms. It melts when heated to the temperature 
of about 250°, and as soon as melted, it begins to sublime with- 
out any decomposition. 

It is exceedingly soluble, both in water and alcohol, ItB 
taste is acid, and it reddens vegetable blues. It combtncB with 
the different bases, and forms salts, distinguished by the name 
of ttuconates. The meconates of potash, soda, and ammoniat 
are soluble in water. This is the case also with the meconatea 
of barytes, lime, and magnesia. 

When meconic acid is dropt into solutions of the peroxide 
of iron, it strikes a strong red colour, similar to the change pro- 
duced upon the same saline solutions by the sulpho-cyanic 
acid. But it does not occasion any precipitation in these liquids. 
When dropt into a solution of sulphate of copper, the colour 
of the liquid changes to a tine emerald green. No precipitate 
fells at first ; but a pale yellow powder is at last deposited. 
This acid likewise produces slowly a precipitate in the solution 
of corrosive sublimate.* 


H»totj. T\as acid was discovered in 181 1, by M. H. Braconnot, while 

examinbig the expressed juice of the boiehts pseudo'igniantts.f 
He obtained it by tlie following process : The juice of the 
boletus was evaporated to a thick syrup by a very low heaL 
The residual matter was digested in alcohol. The portion left 
undissolved by the alcohol was dissolved in water, and nitrate 
of lead dropped into the solution. A white precipitate fell, 
which being edulcorated was mixed with water, and decomposed 
by a current of sulphuretted hydrogen gas. The liquid being 
filtered and evaporated exhibited two distinct acids. The one, 
which existed only in small quantity, was phosphoric acid, and 
deliquesced when exposed to the air. The other constituted 
permanent crystals. It was boietic acid. I'o obtiun it in a 
state of purity it was dissolved in alcohol, and crystallized by 
evaporating the solution. In this state it possesses the follow- 
ing properties : 

• Robiquet, Ann. de Chim. et de Thys. v. 8B2. 
t Arm. de Chim. Ixxx. 878, 


IiN colour is wliiu>, it is not altered by exposure to the air, ^^'^ '■ 

ml coiiid«W of imfirtilur four-ddMl prisms. Its tnste is similar " 
S that of tartar. It rrquiroit I^ times its wciglit of vmtpr to rcdisUA 
Inoirp il at thr tomp«rature of 68". It is soluble in 45 liiiiw 
h vetglit of Alcohol. 

Hio nqueoiis solution r^dcien.i ve^tablc bines. Kilrat« of h 

Eiul uccaAitkns » [)riH-i|>itaU> lit it which in redis^oKTil l>y ajptii- ^M 

Ion. It pre<:i[))(a(i>H the ri^l oxiil<> of intn fmm its sioliitioiit* ^M 

■mpletoly in tk« form of riutt-coloiircd fluclt<i; l)ut irdot-ttnot ^M 

brow down tliv black oxidi-of thix mctni. It preHjiiiat^^s nitrate ^M 

f nlver in thf itUiw of a wliiti> puwdor wliich i^ soliililo in nitrio ^M 

iM, Nilratv of mercury U prccipibitiMl in ilif Mim<> ntiiti-; H 

m thr prccipilntc (IIk<^\'cb with difficulty in nitric Rcid. ^M 

Ji-ither lime wstcr nor haryteswdter produces any effect upon ^M 

ie aqueous solution of this acid. WLon healed it riM-s in ^M 

ritite \-»[>oun, whicli irritate tlie throat, and condense on kui^ ^M 

hmlinfr ImwUcii in tlic form of n farinaceous pon'dcr. Wlicn ^M 

PBk<l tlie ||i;rciilt-«t port sublimes unaltered, excepting that it ^M 

Ikervrartb crystallizes more regularly. At tlie same timv a little ^M 

|l|nid apfiears bavins; a strong; smell of acetic adiL ^^ 
■ Boletatv of ammoiiia It a sidl wliicli cr\'stul1iEes in flat four- miu. 

|d«l prisDui, amt is Nolidde in 2(> limes it^ weight of n'ufer at ^1 

18*. Its taste in cooling, wiline, inid somcwliat sharp. When ^M 

keated it melts, swells, and sulilimc^. It prccipilalCM red oxide ^M 
' iron : but does not alter «ulpluitc« of Itme, alumiiiii, or mnn- 
It slowly preeipitiilcs nitrate of cupper in blue nilliy 

Bolelale of potash is very soluble in wiiler, and cryslallizes 

difficulty. Acids precipitali- thi- bolelic acid from it. 
When boletic acid is lieate^l witit curbniiate of Iinte it dfo- 
il with itffcrvwccnci'. The huletate of lime er^stallixes 
; four-kided jirinmi^ 'I'liis Mill bn» little taste, Hn<l rt-tjuires 
: least I lo times its weight of water at the temperature of 72^" 
< dissolve it. It is decomposed by oxalic and sulphuric acids. 
Buletate of hnrjtes is an acidulous salt in white plates little 
«oluld« in water or nitric acid. When thrown on a red-hot 
on it bnma rapidly with u nn) fliune and striking winlillaliuns, 
iring fur ri'Mi'tue rarlmnatc of hitryte^. 

When ibinneid ix Iicsititl with iron AlirigHandwnlcr, hydrogen 
lift fmilted.uiidu yellow li<iuor i.'obtwincd with an inky tu-stc. 
Sucli are lite pru{>erlics of boleltc acid tw Ihcy Imve been 
ertainetl by Bniconnot. HitJierto no o4her chemist has 

■ted bis experiments. 
II. 1 



Cumplior is a well-known white crystalline iubstanoe, of 
strong Bute ami siQell, obtained from a opeciea of laurel tn the 
Eait Indies. It u so voiatilo iliul >t '» nut readily melted in 
o]>cn vi>»si'Is, aix] so influmniuijlc tliut it bnnts even ou the sur- 
face of water. .fl 

When camphor is set on lire in contact witli oxygen guSi U 
burns with a very briliiant d:une ; niucli eitloric is dj»oiigt^:«d» 
water is formed, the inner itnrfaee of tlie vessel is covered witli 
n black matter, wluL-ti i^ nndoubtcdly cliarcoal, and a tjuantity 
of mrboiiie iicid pi* w uImo produw^fL" Hi*n<;e it follows, tlnil 
it in composed of hyilro^'n and carbon, at leoMt prints! pnlly. d 

Mr, Kosegarlen, by distilling nitric acid off camphor ci|;ht^ 
times successively, obtained an acid in crj'8tEUs,t to which th« 
name of t-awip/ioric acid has been giren. 

Hb expcrimcnta have been repeated by Mr. BouiUoa — 
Ijignatge. The process for obtaining camphoric avid, aifl 
describnl by this diemist, 'u us follows: Put into a n-tort I 
port of aunphor itnd 8 parts of nitric aci<l, of the specilic grur 
vity 1-03. Distil with a sand heat. A great deal of nitrous 
gas and carbonic add gas is emitted, itii<l a little camphor 
sublimes ThU process muit be repeated llirec times on the 
same camphor ; so tlinl '24 parts in all of nitric acid arc ncvu^ 
sary, .\ftrr tlic third di^itillation, when the r«>tort is alloweil ta 
cool, a number of crystals make their uppoarunce in it. These 
are camphoric acid. Iliey amount to somewhat less than the 
half of the camphor employed. _ 

The experiments of Kosegarten and Bouillon I-agnmgeB 
were confirmed in IRIO, by itucholz, who employed the fol- 
lowing prowess for converting camphor into cam]>horic acid. 
'IVo ounces of camplior are put into a retort with I^ lb. of 
nitric Rcid of tlie spceilic gnivity l''i.'il), and lialf a |)ouiid uf 
' jiiming nitric acid of the Kpvcilic gravity 1-550. A nioilcnite 
heat is applied, and about onc-hulf of tlie acid is distilli-d olT. 
Tltls process is repeated thn-c times, pouring iMick the acid 
which has distilled over each time. After the third distillation 
llie ramphoric acid it oliwr^cd swimming on the aci<l in tlie 
retort like a butyniceoiis tonsil aOer the whole has beconn' odd. 
It is scparuted from tlic nitric acid by ineaiM of a gliu" funnel. 
When washed and ilric^l it is camphoric actd in a statu of purity. 

* Bouillon Lu Grsn^-e, Ann. de Cliim. xtlii. 153. 
f Koi^irtcn, de Compliora, &c. IT»A. 






In the Tcv 1823 an trlaborutc set of expcrimenbi on cnnf 
plwrie acid and itanlUwaspubliiOiedbyDr. Uudt^lpli Hntndc^fi.* 
Hit (mtceaa for prvpariii^ it waa Uie siime ta tlat of Bucholz. 
U« gives us tbe weight of tiitrti' ndd n^ciuisitc to convvrt four 
muKv* of cnmphor into c»m|)lioric acid ; bnt m lio Itaa ni^lectod 
k give lU the specific (rravity of (ho acid employed, his aate- 
mrab eonvey little information to Ike practical chemiiit. 

Camphoric acid tliiis pr«pare<l i.t in featlier-abaped cryHtaln. i>*|«i;n 
It bia • white colour. Hi tame in xlif^htly add and liitteri.tli, 
taif Acoanling to Hnuides, convcyx an imprewuou of citmplior. 
At the common temperature of the air it lias scarci'ly any 
mM, but wkrn licutml to lOU* it |riTV4 out a perceptible odour 
rfmnpbor. At the temperature of 100" it bc^ns to^vcout 
a ihicW wliite i-apour, huviri<f an acid and Aitty smell ; nt 15&' 
it melu tuto a tmnspaireiit colourless li4piid. \A hen the tem- 
perature ia Htill farther raised, it catches lire and bnms vith a 
dear flame, leaving iwareely any residue. If it be put into a 
batMl porcekiin tube, aixl oxyj^en fran U' ]iiLvied tbrotijrh it, 
the acid doe* not undergo luiy change, hut t« iiubliine<l. By 
distil 111 I ion it flnt niolto, and then i^ublimeii umiltcrvd.| 

The foUun-tni; table mIiowii tlie solubility of this acid in water 

'difierent tempcraturm, na determined by Dr. Brandcs. 

t Mj^ Fahrenheit. 100 water diasolve M3 
77 . . lOO . . 1-457 

90-S . . 100 . . l-6<26 

12-2 . . 100 . . 2-450 

144-5 . . 100 . . 4-290 

180-5 . . 100 . . 6-29 

lOi . . 100 . . 10-13 

205 1 . 100 . . 1200 

The follou'iitg table, by tlie luime chemist, shows tlie solubi- 
of this add in akohol at differenl temperittnreg. Unfor^ 
rly he bas n^lected to itpvt-ify tlie »i>«cific gravity of the 
dI employed. 

Cuiphiiiii tii. 

At 47''-73 


alcohol dissolve 106 













• Sdrawn^* Julvbucli. v't&. SG9. 

t Bodiot^Otfalen'* Jour, fiir die Ctiemte, PhjMek, und H inenlogie, ii. 33% 


°^^ We see from this that alcohol at the temperatnre of abovt 100°, 

dissolves more of this acid than at higher or lower temperatuKS. 

Oil of turpentine dissolves camphoric acid by the asustanee 

of heat, and allows it to be depcwited in crystals when th« 

solution cools. 

To determine the atomic weight of camphoric add, Brandcs 
analyzed several camphorates. The following table ezhibila 
the results which he obtained. 

1. Camphorate of potash. 
Camphorig acid . . Jl'2*4S 
Potash ... 6 

2. Camphorate ofaotbi. 
Camphoric acid . . 12-6 
Soda ... 4 . 

3. Camphoraie ofHnte. 
Camphoric add . . 13-44 
Ijme . . . 3'& 

4. Camphorate ofbaryUa. 
Camphoric add . . 12-76 
Buytes ... 9-6 

5. CoMphorale <>flead. 
Camphoric acid . . 12-12 
Oxide of lead . . 14 

The numbers after camphoric add in this table indicate the 
atomic weight of the acid deduced from the respective analyses. 
They do not quite agree with each other. But if we leave out 
the camphorate of Ume, which deviates too &r, and take the 
mean of the four other analyses, we obtain very nearly 12-6 
for the atomic weight of this add. 
rmniiaiiim Braodes subjected the add itself to an analysis by means of 
oxide of copper, and obtained for the constituents, 
Hydn^en . . 5-618 

Carbon . . 61-341 

Oxygen . . 33-041 

These numbers would give us for the atomic constitution of the 

6 atoms hydrogen . . 0-75 

11 atoms carbon ■ . 8-25 

4^ atoms oxygen 4-d 


IP S(TBE1l)C ACID, ^^^^ ^^ 117 ■ 

TV ktiunic weight derivMl from these proportions is 13-5t «»-". I 

vliick eonnes very near the ntotnic weiglit of tlie acid deduced '*'''^ m 

ftntn llie nnalysLt of euinphornie of lime. M 

h w ubviouH tluit new experimeitU are still requisite before ^^B 

vp out consider the atomic weiglit or «t«niic coiistilution of ^^H 

ikift add w accurately deterininetC ^^H 


' Cork, a MulMtJince too wi-ll known to require any (le«cription, iiMarr. I 
b ihc iMirk of k tn-c wliieli beiirs the same name. By means m 

•f iiilrie iu'hI Dniifnalclli eunverte^) it into an iicid,* whidi liait ^^fl 

been calK-il Kulnrir acUly from subcrt ilie Latin tiaine of the ^^H 

cork tree. Several eliemit)t8 HfBrine<l tbat tliin acid was the ^^H 

onlict because it poietoHSt'ti jtevend prop^rlie^ in common wilh ^^H 

it. These assertimu induced Bwutllon I^iifrnui^- to iinih-rtiike ^^H 

a M>t of experiments ou Hubcric tici<l. Thcite experimental ^^H 

whicit have bei-n published in lbc2S!d volume of the Anit'ilrsde ^^H 

ChitHiv, eoupli-l<-iy c^itublish ihc peculiar niitnre of suberic ^^^| 

•cid, by «bowirif; iluit it ]>ossesses properties dilfrrt-iit from ^^^| 

those of any otlier aeid. Chevreul af^erwardit published a new ^^V 

act of experiment* on it, which both scne still further to esta- | 

blnb it* p<-ciiliar iiiiliire, and make us better- aci]uainted witli 


rbevreul obtained this acid by di^cstinfr 1 jiart of cork in 
I of acid. After the add had censed to aet, tbc whole wax 
led to the eoiisUtcnce of an extract, hot water was 
poured over it, and tbc mixture was digested fur some time in 
a «an<l lH>at, When iiet a.-<i4)o, a mutter like wax formed cm the 
nir&ee, and while ta«teleic« flock.'* preciptluti-d to llie bottom. 
These Bubstanc^'tt were wparated, and the liijuid eonceutrated 
by eraporution, Suberic acitt precipiljilcd in powder, and 
lovarda die end of the process cryfttiils of oxalic acid formed. 
I obserred tlte formation of oxalic acid many yeani aj^o, wliile 
treating cork with nitric ueid. Htil the mo^t clahomte mm of 
experimt-ntf on ibiN )u:i<) wa'« published by Dr. Rudolf Bmndvx 
(iuriDg the yrxn li**21 ami l6i"-'.( lie not oidy exninitu-d tlie 
profwrties of the acid in detuit, hut determined the composition 
ami profiertiea of the diiferent suberatra. 

Pure iiul>eric acid has a white colour, and is not altered by pMt*rt)». 
exposure to tlie air. Its taste is acid, hut not in the lea-tt bitter, 
unless when it b imjnire. It has no smell. When dried it 

• Ocll't AanOt, I7S7, i. IM. f NichoUon't Journal, ix'tii. 140. 

I Scfawe^Ecr'a Jabrbuch, ii. 3!K1, iii. m, and ti. £63. ^^^ 




lias no lustre. The cryslali of it are imperfect needles. When J 
lieuled it nx-ll* into u traiisparont liquid, which on cooling 
a^iiine^ a yellowish linjEc It melts at tlic temperature of I0(y, 
and remains liipiid till it be cooled down to l'J5*J when it 
■gain congreals. The solid matter is (il>roiis aiid olivioiwly 
rrystullized on Uie surface. It retiuireit a ji^at deal of cold 
water to dissolvv it, hut it is very soluble in hulling water. 
The following tahlc sliow^ the NuUihiltty at different tempera-, 
tores ai determuied hy Bruniles. 


At 4fi* Fahrenheit 1 part of acid dissolrcs mlOO-I 
Mi . . 1 . . . 9l*ttJl 

183 , . 1 . . . 5 

21*2 . . 1 . . . I'87 

The following tahle allows tlie solubility of theacdtliti absolutel 
iilcohol according to tlie determi nation of llie same experimenter.] 


At 50° . . 100 parln alcohol dissolve *21-0 
173 . . 100 . . . 114 

lOOpartS of boiluigsulpliuricctlicrdia)K)lvedl6-6partsof this acid. 

Butetlc b'M. 

At 68^ . . 100 ether dissolve . 12-9 

50 . .100 . . . 12-82 

.^9 . . 100 . . . 9-8 

It is soluble ahio in volatile oils, particularly in oil of turpcntiiM 

M'heii h(!»ted in a retort it U volutili/.ed, and condenses oal 
llie uppor piirl in long neeiUt-K. It doc« not precijnUte linu)^ 
baryti-s, or slroniitiii water, nor the sultd containing these ulka* 
line cartlis. The ulkiilies iliwolve it very well, and (brm witli 
it neutral suits. It precipitates uitratc of silver, muriate of tin, 
sulphate of iron, nitrate and acetate of lead, and nitrate of mer- 
cury, but it docs not precipitate sulphate of copper or sidplutttfl 
of sine. 

Nitric acid lias no action on it. It docs not alter tlie colour of 

sulphate of indigo, provided it is free from yellow bitter matter.* 

l)r. Urarides, in order to determine tlie atomic ueight of 

tliis acid, analyzed several of the ^liberates. The fullou-iii|{ 

table exhibits the results which he ohtiiiiie<L 

1. SkImtoU nfsoda. 

Suberic nvid . . 12-S5 

Soda ... 4 

* NichoLMHi'* Jour. siiiL I4D. 

•IfBBKIC AVID. ^^^^^^ lip 

S. Suberate t^Jime. owt. 

.S.ib«tc4«id . . 11-95 "*■"■ 

Umc . . . Q'S 

3. Suberate <(f fnirj/tea, 
Stilwrio add , . l2-7tl 
Boiylw ... 9-5 

4. SHberate (jf utrotitiaM. 
Suberic acid . . 12-.38 
Slronlian . . . 6-3 

a. Si^cratK ofmaffmMUt. 
Suberic aci<l . . 1I-7H 

Magnesia . . '2-5 

0. Suberate ofttUnrr, 
Suberic acid . . 12-20 

Oxtde of silver . . 14-75 

7. Subtffate iifco/jper. 
tsilieriv iK'id . . 11*93 

Oxide of copper . . 6 

B. Sttbrrate i^flttid. 
Suboric add . . 12-&6 

Oxide of load . . 14 

' DitiBben after Bub^Hc udd denote it» ntomtc wci^Iit acrord- 
tO VSeh atnlyrifl. Tbe MpcrimenU were iiuule on a very 
Kale, wbich nccounu in some measure for llie ti-»nt of 
aceainoitg tliein. TlieiDOKnof iltewliolc ei^hiaiiulyst-s 
ires us 12-15 for tlie aKniiiv wciglit of suberic add. And if 
We Imre out tbe ■ilbenite of magnesia, wliieh gives tiielowest 
nunbcr, and vrhidi is not ho emdly analysed ib the otherst we 
obtain for the atoinie weigbt of tblt acid r2*'JI. tio tltat tbe 
|irobabIe ounilier from ibe^ analyHct in 12-25. 

Dr. Branded llniily/.t^d 1-25 grain of Hubi-ric nvtij by meaiu cmiaHion. 
of osidc of copper, and obtained for the coitstiluciitti, 
Ilydrngen . . \b-9^Q 

Carbon . . 37-25a8 

Oxygeti . . 46-7ei»8 

The nuinl>er of aloma of each constituciil, which correspond 
bat with tJiew propoTtioiis, b as follows, 

16 Ktorat hydrngi-it . . 2 

6 alotn« carbuti . . 4-5 

6 atoiiH oxygen . 6 







This gives IS*.*) fur the atomic weight of BubcrJc acid, 
iienrly tlie niuiic tui lliut deduced from the anulysis of suhenita 
of soda, wliicli wns made upon tlit- (rn-atent scale, and suberate 
of lead wLii-h funiUhett tlic sidt of cavicvt iiimly>i.t. I iim dis- 
posed thi'n-forr to consider 12*5 as the true Rtotnic u'cif^ht of ^ 
thts aci<L Suberic acid iti remarkable for the great proportion of " 
hydrogen which it contjiiDS, it nii^ulur circiimstaiice if we ooa- 
Hider the great cjiuuitiiy of nitric ucid employed in its formation. 


It hfls been long known that the juice of currants, goosc- 
berriefl, cborrtcs, apples, and many other fruits, when lefi 
exposi'^t i<i the air, gradually axKumea the form of a jelly, i^me 
obeerviitiuns on thiK jelly hiul been made m<uiy years ago by 
Vuuquvlin ;• but it was M. [{ruconuot who first pointed out its 
Bcid nature, showed tlie method of procuring it pure, and 
dcseribc<l its character in deUiil.f Some [i<lditioiuil fact» 
were iifterwards brouglit to light by the experiment* of Vau- 
queUii.J Braeoniiot ji^uve it the name of peclic^ acid) from tli« 
great tendency which ir hoA to form a jelly witli water. 

It may b<- ubtiiincd from iJie roots of carrots, turnips, par«e- 
ni])*, &c, from the inner !)urk of most trees, from the greater 
MiimlHT of fruits, ao tlwii it appears to be very univemally 
Bwittered over the vi-geudile kingdom. One of the sulwtancei 
from which it is most easily procured is the ctunmon earroL 
I'hc method of proceeding in us follows : Ilaring well nikshed 
tlie carrots, reduce them to a pulp by means of a grater. 
Express the juice and wasli the dry residue with pure water, ' 
till it ceaM» when squeezed out of the pulp to be in tJie least 
coloured. Mix 50 parts of this u-ashed and expressed pulp 
with 300 parts of water and one part of caustic potash. Heat 
lliia mixture and boil it for a cjuarter of an hoiu-. Filter the 
liquid tiirough a cloth, luid wash the undimsolved portion with 
pure water. Mix all Ihc^e liquids togetlier, and add to tlicw 
white »lill hot a very dilute sulution of muriate of Ume. 'lli« 
pectatc of lime formed tnimeiliatt^ly gelatiui/es. It is collecU-d 
and well washed upon a cloth. 'I'lien boil it for some minutes 
witi) water addulaled with muriatic acid, which dissolves the 
lime and the starch sliould any be present. 'I'be whole Wing 
now lluown on a filter it is in the state of a jelly, which 
be waJied with fiicility. 

■ Aon. lit Chiui. v. 9i. vi. »7i, 

t Ann. do CHiin. et de Phf«. xxttli. 173. xxx> OS. % Ibid. slL 

§ Fhim BwAti oocmuluo). 



^P irEcrtc ActD. 121 

^'a^qllcIiD informs ua ilmt tlie jirocess is facilitated hy giiW o« r. J 
•liruting l>i«iTl>«>iiiit4> of potwh, ar cr)«tj«lli/<Mi carljoiialc of . "*" "" 
KMio, is the |irD[iuniDii of 5 parts for every UK) p«rr» of ihe 
[-.•xpnMod pulp. The rwl of Ui» prof(«s is tlie luimc as lliat of 
Bracnmiiil jiLst (lescriliMl, 

Tims obuiiiied )>evti<: iicid lias the form of a transparent and enpmia 
c«b>urleBH jelly, lu iiistc is perceptibly add, and it retUlenit 
pciiter Hlaimvl Mui- l>y lilmus. It is scarcely nolidilf in cold 
ntvT. IJoiliiig water dissolves it In itinalt fjiuiiitity. Tlio 
I filtrrv^ wolutioD is colourless, iinil do<>M not lot any sediment 
hA on cooling. aiHl M-arCely reddens lilmns paper. It is coagu* 
BMM inlo n jelly colourless like glas**, hy alcoliol and all 
jinrbillic solutions nitlioul exception; by litne and bttryt«s 
prater, hy acitk, by muriate and sulphate of sodii, nitrate of 
|)>ota»b, &c. Even su^r when addct) lo llie u'ater, causes the 
^ectic add tu iLViunie the form of a jelly. 
I \N'Uen dried upon n capsule it assumes die form of trans- 
mrent plutcw, which do not atlhere to the glass tesAcl. In 
Rlu8 "tnie it seiircely swells when put into cold waiter; hut it 
■■Molves u little iji hoiting water, and the solution nmi^nlatca 
py all the difTervnt rea^'iits m at first. When <lUtiIled in a 
|Kt0rt, il yields n good deal of cmpyreumatic oil; but no 
pmmonia nor murblic ncid, and Icuvrs behind it a bulky coal. 
nA^hrn mixetl «-i(h water it lins the projtcrty of <lijiengiiging 
iewbonic add from the alknline csrbonuti"^. 
I Wlicn mud wHth an excess of enustie potash in a |)]»tiiium 
kmcible, oimI gently healed, agitutiii^ the mixture uircfuUy, it 
noon melts and assumes a brown colour. If we e ni]>onite llic 
jlitpiiil without increasing the heat much, we will observe that 
hvlu^n the water !» driven off ri'miiins tu tlie crucible again 
wnniiii n a white colour, and if we exiimine it we shall tind it 
■o ecNubt of oxalate of potusli, Ily tliix process the pectic acid 
Bwa been converted into oxalte acid.* 

W'itli potasli, pectic acid forms ii salt which lias little tmtC) aub. 
tutd is very soluble in nater. Wcuk alcohol tlirows it down in 
the form of a jelly. When this jelly is dried it assumes a farm 
memhiing gum arable, and M?arccly adheres to tlie gUiAS in 
hich the evaporation wns carried on. When heated it swelhi, 
:td leave* a l>n>wn mniler, which is ulntinc united to potash. 
Pcctaic of potath, when in Kolution in water, is coaguLite<l by 
all the substances which produce tlie same effect on pectic aci<i. 

* Vauqudin ; Ann. de Chiiii. et ile llijv. xlL U> 





Tlie 4^a^tlly and invbillic salu dccoiniiose U by double nffiiiity. 
According to the analysis of Braconnot it u u compoiuid of 
Pecticacid . . S3-29 
Potasli ... 6 

Hoiicc it wouIJ ajipear timt its atomic wciglit is about JW. 

Most of ilie otiier ]>i>ctati.'« ar« insoluble, and may be obtained 
by double docompoKition. 

Cold ftiilpliuric uci<l Ium little action on it; wben heat is 
applied HiilplKiroiisiicid is jrivenolTurid ulmine fonned. Wben 
nitric acul u distilled off it, tbc reuduo funiinlivii oxalic acid. 

Bnicotiiiot, in conscqiieni« of ibe property which tliis acid 
lias of converting a vast quaiitity of water into a jelly, has pro- 
posed the intro<luctioti of it un<ler that form as a very palatable 
food. The Dictlim) of prep.iring tlie^e jellies is as follows: 
Boil « little poetic acid in the quantity of water which is to b« 
converted into a jelly, tlien dissolve iu the wuU^r a HufEcient 
quantity of su|^r previously seasoned by being rubbed over the 
Am of an orange, or by any other wialied for seasoning, or acid 
to the water a little alcohol previnii.^ly properly seasoned. Ill ^ 
«ither case the whole assumes the fiinii of a jelly, the flavour of w 
which will of course depend upon the nature of the seasoning 

These jellies liquefy with extreme facility when a tittle ain« 
monia is poured upon them. 

Broooniiot is of opinion that the soluble pectates constitute 
a complete antidote iiguinst all metallic poisons, such as tliose 
.of lead, copper, zinc, anliotony, and mercury. Ilis reason is, 
that the salts of all these metals are decomposed by pectate of 
potash, and tlie metalline pectate formed is <)iule insoluble, and 
not likely to prove injurious to tlie aiiiuiol economy, 
h lid's inference is not quite unobjectionable, yet the 
inaolubiltty of such jiectales would form a reason for adminis- 
tering pectate of potash in all cases when a poisonous metallic 
salt had been taken into the stomach. Braconnot excepts cor- 
roMVc sulilimatc, niltate of silver, and tartar emetic, because 
the insoluble pectates obtained from them are soluble in aa 
excess of pectate of pota^i. 

l.I|ion tlie whole, tlie properties of pecticacid arc iiitrre^ting, 
and its nature aiid properties deserve a much more comjilcto 
investigation than tliey have hitherto met with. 



Tlie examination of the constitution of «u)ijih wkm begun 



Cbrvreul iibout die year 161.3. He at tliat time gave to Ute 

[ laitUute mn account of ait aciil subMance wliivh eDtera into die . 

I mnposUton of soajus, and tu wltieli lie piro tlie uame of ima/-- 

\far^. Id 1616 be <IUliiigiiUlitMl it by lliv luimv of taarifaric 

teut. AUiut tlic Hune lime he found tliat nuirKuric lu-id vx- 

Incwil from dilTi-rritt bodies exi&ted ia iwodtfierent states, and 

M i1m ooc contained more oxygen tluui tke other, he distin- 

"ked iheni ni fintt by the oain« oftuar^raus »nd margarie 

Hut he tltoti^bt it aftervrards better to give to margar' 

: acid the iiamv of tlearic* aeid, and to retain the leru mar- 

• acid, which had been applied lo the otber at first. 

The method of )in>curiitg Htearic acid a as follows : Muke a 

by boiling mutton siict nud utustie {lotasli together, with 

LMiffident quantity of n-atcr, till thi- whole is converted into 

DiMwlve otic pitrt of this soap in (i piirtK of warui water, 

mix the solution with about 40 partd of cold wiiCcr, and 

kve it for some time in a tem{>emtiire about GO" or between 

aud 70", A sulnlniicc precipitates liaving a pearly lustra, 

rhich is a iiiixtiin.' iif /lisUnrntt- nf'j>iirn»/i and mnrtjiiriilf tifpot- 

Colle<-t this Biilistancc on tiie filU'r an<l wa-dt it. The 

E()ut() tliat has |>tu»cd throi^ tiie filter being mixed widi a 

Ettleaod tomtniatethepotiisji which itiiowvontuinsinexceK^ 

rill yi«U an additional quantity of (hl% twofold soupy siilu By 

diis procesa wveral times all the bistenrute of pota«h 

margamte of potash is obtained, an<l the water retains otdy 

the oleate of {wtiLth. Tliv bLtte;iritte and mat^arate of potash 

U lo lie drictl ant) diwolveil in about 'it) tiiiie« \Ut weight of hot 

alcoJiwl of 0-ttii. When the alcohol cools a cjuiuttity of histea- 

rale of potaali mixed with mai^arate of potash precipitates, and 

oleatc nf jMta&h and margurate of potasli remains in solution in 

die oteohoL 

Tbc |ireci)H(ated btstenrate of and margarate of pot- 
•■b is to be again dUsolved in boiling alcohol, which is to be 
act by to cool, 'i'he bi)>tearute wLich now piecipibitcrH is much 
freer from margarutc, a»d by repeating the wlutiuu in lyoiliitg 
alcohol two or three dmcs, it is at last got peTfectly pure. To 
(li-it-nnine whetlier die bistenraie is (jnile pure, take a UtUe of 
it and ilecompo»o it by muriatic acid. Put tlio acid which 
•epanlei (afterwashingit)in wat<T, die teinponilnre of which ia 
to be gradually raised. If the acid docs not melt till tlic tunt> 
panturc of the water rc»che« Ma' it is pure stearic acid. If 

Out 1. 

* Frooi '^M{. tallow. 


U melts at a lower temperalure it contains u mixture of mar- 
gsric ncid. The mcantle of potash being thus olriiuiieil in a 
state of purity, it is 4)ecuin]>o«Ml by tioiling it witJi nuiriiitie 
acid and wiitor. The stearic acid u to l)« separated when the 
mixtiirv gets cold, and it may tw freed fnim all admixture of 
muriatic acid by fusing it repeatedly in pure wutvr. 
pioi«us. Stearic acid has a fine white colour, and when llie fused acid 
is allowed to wiol below Ift8» it cryslallizM in fine brilluuiC 
n«edles. It in taAteless and deittiliite of &meU. It is inM)liil>lc 
in water, Whih^ Ittpitd it inny be tiiixed with hot alcoliol in 
all prAportioiu. If we heat I part of alcohol of the specific 
gnivily ((■794 with one piirt of •tcaric acid to the temperature of 
167", we obtain a solution which remains litjiiid till cooled to 
12*2°. It tlien crystallizes in brilliant sades, luid it become* 
(|uite solid at I lli". \\'hen stearic acid isheated with its own 
weifiht of clher of the specific gravity 0-7'27 in a tube shut by 
the tinger, a solution talci's place, which is limpid at ItiO", but 
' at 134° it becomes soli<l, and coiiKBtH of a congorie« of brilliant 

This acid combines witli concentrated sulphuric acid with- 
out undergoing decom]iasitioti. It bos the projierty of re^Iden* 
ing Tegelid)le lilues. It combines witli tli« bases and forma a 
class of ndtK ndlei) ttetiraif*. At the ti^'mpeniture of t^l'i^ it 
dJaengngcH carbonic ncid from the carbotuiles of potusl) oiid soda. 

When this acid is distilled it gives out a little carbonic acid 
and a little carbnrelted hydrogen, and an oily matter passes 
over which is siearit acid a little altered in iLs ]iro{>erties. 
When st<-aric acitl is Uenle<l sufficiently iti an open vessel it 
burns like vnx. When digested with nilricnctdit isconrcrted 
into an an<l which possesses peculiar properties, but which 
hitherto lias been very little examined.* 

From the aiudyses of different BjK'des of 8teRratc« by CIhjt- 
reul, it ajtpears iJint the atotnic weight is very nearly .^l-SS. 
'I'he Hcitl in its usual state is a hydrate, being composed of 
Stearic acid , , .30*B 
Water . . . 1-173 

It b obviously therefore a compound of 

I atom acid . . .'W-.'J.I 
1 atom water . , l-i'J5 

The small surplus of water is doubtless meclianically lodged 
between the pariiclee of tlic ncid. 

• ;«pe BrsMnnol ; Ann. tie Chuu. xaii. SWi and ChenviiJ tw faf tvrpt 
gnu, p. ia 



Ficid was itnftlyied br CWvtcuI I>v mcaiw of oxudo of cimi. 
PCopper, and he found the consticucats to bo 

Carbon . . 80-145 

Hydrogen . . 12-478 

IICow the number of atoms correspondini; to ihfuf wtriglits And 
> die atomic weiglil of tliv uvid i» the following : 
2 atoms uxyfiren . . 3 

36 atonu carbon . , 27 

34 atoms hydrogen . 4-25 

^l'h« anaJywt of Ch«x-r«ul gives 2^ aton)!i oxygen instead of 2 
itouM. But this wouUl inake tliv Hlomic weight too high. W« 
(bat vtcaric acid miwt bv of u very complicated nature 
since it contains no fewer than 72 atoms.* 


This add was one of tbo first which Chcvieul discovered, mmott. 
ut it was only by degrees tliut lie uiis able to <]!!<tjii^iis1i 
twcen stearic and margaric acid. Itmay be obtaiuetl by the 
Unwing process : 

.*Noap made of olive oit aiitl jiotash is to be maecrated for 24 
luurs in twice its weight of cold Eileohol. The oleate of pot- 
asli is cUsM>lved and the margaratc of potash remains undissolved. 
Jt inunt be well washed with cold alcohol and then dissolved in 
timvs It* w(;i|;ht of bulling alcohol. When tlie liquid cools 
lUB^unile of ))oLi!>b sliuotn into erystaU, but still contamin- 
ated with a little ok'iitv of giotasli. l)ii«olvv it uf^in in hot alco- 
hol an<l allow it to crystallize a wcond time. ']'■> Hce whetlier 
jt be now pure mnrgunitc of potash, decompose a portion of 
by iiieaiiB of muriiittc acid, and observe wh'-tht-r the aei<l 

lied fuses at 140°; if it does, it is pure marguric acid, but , 
it doe* not, it b contaminated witli oleic iicid, and the salt 
ntist tberofore be again dltyil ved in hot alcohol and erystnllized. 
e must proce<-<i in tliis way till we obtain pure margarate of 
This Kidt is to be decomposed by muriatic acid, and 
ii'd and purified precisely iti the way directed in tlie hut 
lon for purifyii^ stearic acid. 

* Cbevreul ntr b$ torpi gnrt, p. 81. 


'^^^ *• The properdea of mnrgaric acid are very similar to tliose of 
Pf^mtia. stearic acid. The only characteristic difference is that it melt« 
at 140°, while stearic acid does not melt till heated up to 158°. 
Mai^aric acid is exceedingly soluble in alcohol and ether, but 
like stearic acid it is ins(^ublG in water. It reddens litmus 
paper, decomposes the alkaline carbonates, and forms a genus 
of salts to which the name of mai^arates has been ^reo. 

Chevreul analyzed a number of margarates. Hie atomic 
weight of margaric acid as derived from these analyses differi 
somewhat, as may be seen by the following table. 

1. Margarate qfpotask. 

Margaric acid 




2. MargartUe of soda. 

Margaric acid 


Soda .... 


3. Margarate qfbarytea 

Margaric acid . , 




4. Margarate of lime. 

Margaric acid 


Lime .... 


5. Margarate of lead. 

Margaric acid 


Oxide of lead 


The mean of all these analyses gives us 32-996. We nuy 
therefore conclude it to be probable that the atomic weight of 
this acid is 33, which is a very little lighter than stearic acid. 
Margaric acid in its common state is a hydrate compound of 
Margaric acid . . 83 
Water . . . 1162 

It is obviously a compound of one atom acid and one etora 
conpadtion, CbevTeul analyzed margaric acid by means of oxide of ct^per 
and obtained for the constituents 

Oxygen . . 8-937 

Carbon . . 79-053 

Hydrogen . . 12-010 


The number of atoms which corresponds with these nomben, 
and suits the atomic weight of the acid, is the following: 


35 utomE aahon . . 26-25 ""•"■ 

•12 alonis by<lrof^«it . . 4 

E 33-25 

ic wei^lit of stonrlc and nini^;ark acids arc Ibo Hune. 
But nuirguric lund contnins one atom more of oxygen, one atom 
^^(W of caurboit, and tu-o atoms lem of livilroj^n. The number 
^Psf alons in ihia uvid amouniii lo 70, ii-)i:lv thu«e in Mi^rk- acid 
unount to 72. Tlius t]ie differences between Uieir eluinteteni, 
llioii^ not rery Btrilung, are accomgniniicd by a decided difTur- 
noe in oonpasitiou. 


e!d wM lintt described by Cbevrcul in 1813, under llic m-f^. 
of i/rniMe Jlitide. It nwy be obtained by the following 
Moke a wap by uniting liuoeed or lii^inp oi) unth 
potnb. lyigogt it ill cold .ilenhol free from water. The uleate 
sf poll^ will be diiuolvi'tl, iiml tin- mnr<riirutv of polnnli, wbicti 
ffidsti only in unall t^uiuitily, will rcnmtn tinacteil on. Ia*c 
tbe solution be eva|iornif(l, anil let Ihc rraitbie bo tresttcd n'itb 
lie smallfHt (juanlity of ab^ohite alcobvl cnpable of diHsulvirijf 
iL l<et it l>c M-|>iiruled from tlie iim:tll ciuaiility of ninrguntte 
«f potMb that remains undi§solved. Let tl then be mixed with 
water, and decomposed by boiling it witli muiiatic arid. 

Oleic acid tliuit obtained bas tbe appearance of a colourless ifw^'^ 
oiL At tlte temperature of 60' its Hpecific gravity ia 0*d&8> 
A ttw degrees below 32° it congcnU into u Mtlid man composed 
of needtea. It has a flight odour m>d taste of rancidity. It 
toay be volatilised in \-aciio without alteration. It is insoluble 
in Toter. Hut in alcohol of the specific giavity 0-822, it diti- 
wires in any profwrtioii wliatever. When «Titer is mixed witli 
tlie Bolution the aetd sepurales. It discomposes tlie alkaline 
cmrixmateA, strongly re^ldens litmus p!)|ier, and forms a class of 
MllKfOr ratlier MMtft», to whidi tbe name oiolealta has been given. 

Itoomhuint in all proptirtious with stearic and iiuiTgaric ac-i<Is. 
Mlirn such u conijNiunti i» tntutt-d witli cold alcohol, much of 
tlie oleic acid w dtmolved, togctlier wttli a little of the stearic 
or BHUgKric iicid. When we treat tbe same compound with 
•leohol heatml up to 140* tbewhole is dixKolred. Astlicsolu- 
tion cooU crystals of stearic acid or margnric iicid are depo^id-d, 
cmitoining u little oleic acid. At a low temperalua' oleic acid 
unium wlJji tulpliuric arid without decomposition. 





atomic wetglit of oleic new! \» only QS-'IS. For 3-95 : 100 : : 
1*125 : 28"48. But littU- rcluince caii be put in this cstimato, 
as doabtloss the acid containod hypromelrieai u'ater. 

Chevreul analysed the acid by means of oxide of copper, and 
found its coiifttituoiitit to be 

Oxygen . . 7-699 

Carbon . . 80-942 

Hydrogen . . 11-359 

Tlip number of atoms corresponding nntb thc«« wciglttt 
with tJie atomic wtiiftht of llic iicid, is us follows : 
2J utoms oxygra . . 2*5 

35 atoms ciirbon . . 26 

30 atoms hydrogen . . 3-75 

This would make tlic ntomic weight of oleic acid oidy 33^ 
which Ui very m-iirly the moun of (liat dodiiccd from tlie anal) 
of olealc of barytcs, and olcate of lead." 


This acid was discovered by Chevreul in 18l7,and described 
by him in 1818, mider tjie name of rM/ifiinic acid. He after- 
wards changed tlic iihihi; to ji^ocfnic to avoid iiinbif^iiily, as ibc 
term drtiihiHif hiid bt-oii already applied to a vegetjihU- princi- 
ple. This acid e\ii>ts in the oil of the porpoise (drlphintit 
fflohicrps). It exists also in small quantity in train oil, awl ii^ 
tlie berries of the viburmnn opuhis, ^ 

To prepitre it a sou]) must be mnde in (lie usual way of por- 
poise oil and putii»b. Tlii^soapistobc decomposed by tartaric 
acid, and the aqueous liquid freeil Jram the stearic, mArgoric, 
and oleic acids Is to he put into n ehii«e flank with more tartaric 
acid. By this momiH niwt of the potuth U precipilated in the 
state of i)itartratc. The li(|uid beJng distilled, phocenic acid 
comes over idong with the water. Siitumlelhetu-id thus obtained 
with barytes, and evaporate the solution in order to obtain ]>ho* 
ccnate of barytes in the state of crystals. Put 100 parts of 
phocenate of baryles into a narrow glass tube shut at one end. 
Tour upon tlntn -J05 jiarLs of aqueotix phosphoric acid of the 
speciBc gravity 1-12, «nd agilatv witli a ])1atinuRi wire. We 

* ChcTTCiil Mr let ctirptpiu, p. 75. 


obtab, I. Sululpho«pluilcori>uryto<(; '2. Anaqucousliqiiidsatu- <^)^{> 

lUed witliphocenica4:id; aii<I 3. Hydratcd plioccnicacictvluch _! 

•vitBS upon the aqueous liquid. Draw off tiieplioceiiic acid by 
Wfwnn uf n sucker ; and duitil it by a ^fntle sand heat The 
liquid it) tlie receiver consists of two different layeni. Tliat 
next tlif button U unall in quantity, and »ecia<« to I)l* u simple 
solution of phoix'nic iivid in water. The iippiT luycr is much 
awrv «bundaiit. It is ii )iydraI<Nl plioceiiic nciil of tlic spedfic 
rmvity 0.933. at tlic U-mpcrutun* of 8'J'. Tu obtain it quite 
pure, nruiMtate it in a small. retort over two or three tiineii ita 
wei^lil nf cliloride of calcium, during four dayii. Tlien diKlil 
0%-er a wiit«r batlt till nothing more couie over. ' 'Die acid thuti 
obtnined Uaa a ^j)ccilic jfRiTity of 0-93*2 at 68", and docs not 
precipitate nitrate of silver. 

I^occnie «ci<i thus prepared is a limpiil colourless liquid like IW"|"' 
a volatile oil. Ic does not congeal though coolcil ihiwii to 
16*. ItboiU wh«n heated a few dcgrxres higher than il'i". It 
Buy be distilled over witliout dvcompositiou. It Itas a strong 
atelt, quid* [leculiar ; but bearing some aiiali^y to that of acetic 
and of rancid butler. It slain.t paper like oil, and gives to 
IkkIic* a dimgreeabte. sniell like Uiat of randd truin oil. 

hm a sliarp acid taste, with an I'tlifriul iinprot<.>ii)n. 

At the tempi- nit u re of Hfi", 1(H) purU of w«tcr diswlve about 
p«ru of tliis add. Alcohol of the spcdfic gravity 0-794 
;vea any quantity of it wluitever. It diiisolves in sulphuric 
■lao in nitric acid without undergoing any alteration. It 
iHiniH like a volatile oil. It combinefi iiith tlie dillerent bases, 
■nil forms a genus of salts called plweennUs. Chevrciil niialyiced 
MV0bI of the&c »ults, aitd found tlu* composition as foUou-s: 

1. PhixoKiU i]f' barytts. 
I^ioceiiic ucid , . 11*47 
Burytes ... 9-3 

2. Ph<xenate of potash. 
I'hoconic acid ■ . ll-Si 
Potash ... 6 

3. Phoccntitc (fkati. 
Phoceaic acid . . 1 1-62 
Oxi<le of lead . . 14 
!»• iiumher* after phoceuic acid in eat-h analysis reprcsciit the 
oiniv weiyhl of tlie acid. The mean derived from (he three 
ecedin^ analyses is 1 1'44. The iitomic weight derived from 

I'liat* of iime is 10-79. 
^evreul suhjvctfd tJie add itself to analysis, by heating 


cba^ 1. pliocenate of lead with oxide of copper. He obtained fiw the 
ceovMiai. constituents of the acid, 

Oxygen . . . 26-75 

Carbon . . . 65-00 

Hydrogen . . . 8-25 


The nunber of atoms which correspond with these constitit- 
enla, and with the atomic weight of the acid, is as follows, 

3 atoms oxygen . . 3 

10 atoms carbon . . 7-5 

7^ atwna hydrogen . , 0'9376 

This number almost coincides with that deduced from the 
analyses of the phocenates. Perhaps we might, without ii^ - 
propriety, leave out the h^ atom of hydrogen, in which cMe 
the atomic weight would be reduced to 1 1-375. 

The hydrated phocenic acid, according to Chevrenl's inalyait 
is a compound of 

Phocenic acid . . ll'S 

Water . . . 1137 

We see irom this that it is a compound of 1 atom add and 1 
«tom water.* 


f»**<>^- The existence of this acid was announced by Chevreul in 

1814; but it was not till the year 1618 that he succeeded in 
obtaining it in a state of purity. It may be obtained by tlie 
following process : 

Butter b to be converted into a soap precisely in the way 
described when treating of stearic acid. The soap is to be 
decomposed, and distilled exactly as was described in the last 
section for procuring phocenic acid. The dbtilled liquid is to 
be saturated with barytes and evaporated. The matter obtained 
is a mixture of butyrate, caproate, and caprate ofbaryteB. It 
must be digested in 2*77 times its weight of cold water for 24 
hours. The undissolved portion is to be again digested 24 bourt 
in 2-77 times its weight of water, and this must be repeated till 
nothing remains undissolved but carbonate of barytes. As 
butyrate of barytes b soluble in 2'77 times its weight of cold 

* Cherrcul, ntr let carpt grai, p. 09, 



HBr« tlio whole of it in fuumi En tlip first Holution mixed with 
■ Irtdc of th« iwo oUier aaltn. Tlie iirxt solution consists _ 
chiefly of caprontp, and the last of cnpmte of liaryt*-s m the 
l(Mt iMluMe Kilt of (iie three, liy re[>eatt^l iTyKtulli/ntiun.t tlic 
hulynitc of b«rytet) is freed from tlie nilmixturc of tjie other ■ 
wlu, nnd ohUkined in a ^tat« of purity, 'i'liv biitymte of barj-tes I 
H dieco[n[>o<t(i) ill u t;Uisa lube by mcaiu of ptimphoric aa&, and H 
the b«tr}'tic acid obbiinod precisely tn the same way as the H 
phoceiiic acid iti obtained, and as the process waa described in H 
the hurt section.* fl 

Butyric acid thus prepared is a colouTle<i<i li(|U id, which does rntnitM 
Dot cou^il tiiough cooled dowu to 16'. It boiUwben healed 
m &w degrees hi|{her than 212°. At 54)" its speciSc gravity it 
'9675. ItM utlour is analogou<i to tliat nf acetic ueid and "M 
id butter cunjoinw!; sumeu'li:it .limil.-u- to thiit of p licet- iiic I 
acid, but not ho Htroiig. It Mains pitpcr like oil, but the stiiin I 

iiinppe«ni by tlie evaporation of the acid. It has a stranc^ acid m 
taalVi leaving an impression of sweetness. Like phoeenic acid H 

whitens the gwrl of the tongue to which it is applied. I 

\^'atcr dis«olvrs it iit all proportions. A golutiiin of two I 
[KirtHacid in one part of water has a i(pts:ii>c jrnivit}' of 1-00287. ^ 
Alcohol of the spci'ifie gravity ((■"i)4, diwtdves it in all propor- 
tions. The solution lias an etiieriu) odour of pippins (pommc 
de reinettv). Concentrated suphuric acid dissolves it at 60^ 
with the evolution of lieat. Cold nitric acid of thi- sjH'cific 
Hy I'JJli, dtiiAolvrti il also without any ulli-niiion. The 

lutiun lata an ethertul Hinell. When mixed with lioj^s-laTd, 
It (ipves it an exact rcsembUince to butter. But when exposed 
ttr tJie air (he aciil j^duiilly cscap4^'s, and the lard remains 
■uiaitered. Butyric add bums like the volatile oiU. 

It combines with ba»es and fonnx a geim» of salts called 
hulyratrM. The following tidile exhibits the constitution of 
df tliese aalta as luialyxc*! by Cbe\-TeuL 


1. tSutyrate ofbanjttt. 
DiityricacHl . . . 

2. Biitftrnif. i^/ime. 
Butyric add 
Lime . . . > 




■ Tbe roder will flfld a dctotlcH trtnlemeni of ibc- pro< 
r let rorjM grot, p. 8U. 

in Chetroul 


"^'- a BtdyraU ofpotath. 

Butyric acid . . 9*8 

Potash ... 6 

4. Butyrate of soda. 
Butyric acid . ■ 10 
Soda .... 4 

5. Btdyrate of lead. 
Butyric acid . . 9-14 
Oxide of lead . . 14 

The mean of these numbers gives 9*62 as the atomic weight 

of butyric acid. 

Chevreul analyzed butyric acid by heating butyrate of lea;d 

with a sufficient quantity of oxide of copper. He found it 
^^''Vi^'i^ reBolvable into the following constituents. 

Oxygen . . . 30-17 

Carbon . . . 62-511 

Hydrogen . . . 7*01 

The number of atoms best agreeing with this constitution, and 

with the atomic weight deduced from the analysis of the buCy- 

lates, is the following, 

3 atoms oxygen . . 3 
6 atoms carbon , . 6 

5 atoms hydrc^n . . 0*625 

Butyric acid in its ordinary state is composed, according to 
the analysis of Chevreul, of 

Butyric acid . . 9-625 

Water . . . 1116 

is obviously a compound of 1 atom acid and 1 atom water. 


UMrr. This acid was discovered by Chevreul in 1818. It wa> 

named from capra, a goat, because it exists in the butter of 
the cow and goat. 

Caproic acid is obtained in the state of caproate of barytes by 
the processes described in the last section. The 2d solution in 
the 2-77 of water consists chiefly of caproate of barytes, and it 
is to be freed from the small quantity of caprate of barytes 
which it contains by repeated crystallizations and solutions. 
One part of caproate of barytes is to be put into a glass tube 
with 0*2963 of sulphuric acid diluted with its own weight of 

* Cbevreul t» let corpt grot, p. 1 15. 



After 24 houn; lh« caproic acid vt-hich has sepunttod is 

to b* <lrawn off. It is lo be dijfcsted for 48 hoiin on its own 

vf iffhl of dtlorido of calcium and then distilled. 

Caproic acid is a colourless liqiiiii, reseinliling a volatile oil "opaii*. 
in sppt-amice. It does not congeal al 16", and it may be dis- 
dllvd over without decora position. At 79° itt sptrcific grarity 
m 0'9^. lu taatv h a sharp acid, leaving a sweeUiOi iinjirc^- 
■i«i on UiC paUilf. Its smell resembles tliat of weak accttc 
aad, or nillirr sweat. It whitens tliose parts of the tongue to 
vkich it IS applied. 

Al t]ie tetnperuturn of 45°, 100 parts of water dissolve 1*04 

of ct])ruic acid. Dut alcohol of tlie specitic gravity 0-794, dis- 

ilvp« It in all projiortioRs. It comhinctt wttliout decomposition 

ilh conc<*iitrate<t sulphuric acid, aiid with nitric iwid of th« 

; gnivity l*iH2. It burN.t with flame like tlie volatile oils. 

It oombiiim wttli l>aseit, and formx a ^onti« of salts called 

Chcrreul analyziHl several of these caproates, and 

btained the following rcsulu : 

1. CapTvate <jf bars/fcs. 


Caproic add 

13- 1 1 



2. CaptwUe of time. 

Caproic aviil 




3. Caprvate of potash. 

Caproic acid 




4. Caproate(ftoda. 

Caproic ucid 


Soda .... 


le ineao of tliesc analyses gives aa 13'75 for the atomic 

ight of aiproicacid. Itwasamilyzed by 

Chevreul by means 

' oxide of copper. He found tJic constituents to be 
Oxygen . . . 2267 

Carbon . . . 68-63 

Hydrogen . . 9-00 


The atoms coming noarcst lo tke«e numbers, and corresponding 

Klhe atomic weight deduced from tli« analynes of the 
he following : 



3 atooiB oxygen . , 8 

12 atoms carbon . . 9 
10 atoms hydrogen . . 1-26 

C^nroic acid, in its natnr&l st^e, is a hydrate composed of 
Caproicacid . . 13-25 

Water . . 1147 

It is obvioiuiy, therefore, a compound of 1 atom acid and 1 
atom water.* 


HMoTT. This acid was discovered by Chevreul in 1818, at the same 

time with the caproic : and the name was also derived from 
capra, because, like the two preceding acids, it exists in the 
butter of the cow and the goat. 

It exists in the aqueous solutions of butyrate of barytei, 
described in the two last sections, as dissolved in 2-77 water at 
different times. The greatest portion of the third solution 
consuls of caprate of barytes. It is purified by repeated crys- 
tallizatiouB and solutions. And tKe pure caprate of barytes 
may be either decomposed by means of phosphoric acid or 
sulphuric acid, in the way described in the two last sections. 

p«vMn. Capric acid is solid, and has the shape of colourless needles 
at the temperature of 62°. At 64° it melts into a transparent 
colourless liquid resembling a volatile oiL Its specific gravity 
at 64° is 0-9103. Its taste is acid and hot. It has the smell 
of caproic acid with a slight odour of the goat. It is very little 
soluble in water at the temperature of 68°, 1000 parts of water 
dissolving only one part of capric acid ; but alcohol dissolves it 
in all proportion^. 

It forms a genus of salts called capratea, two of which were 
analyzed by Chevreul with the following results : 

1. CaprtUe of barytes. 
Capric add . 16-83 

Barytes . 9-5 

2. Caprate qf sirotUian. 
Capric acid . 17*1 

Strontian . . 6-5 

The mean of these two analyses gives 16-96 for the atomic 

weight <^ capric acid. 

* Cheneul tur lei corpi grat, p. iSi. 



id l>eing analyzed bi llic usiud manner by Clievrcul, 
found coiiipoA«d of 

Uxygeu . 16^5 

Cuboa 74-00 

Hydrogea . . . ll-7;j 

01*. 0. 

atoms oomBpooding hfM H-ith ilu<s<- pn^rtions, and cm«i>>w«. 
the atomic weight deduced trom tlie saltt, are the 

f<iUowit>g : 

li Htoma oxygca 
18 atont carbon 
14 atonB liydrogttn 



iat if 19-25 I>c Uiv atomic wc-iglit of ibe add, CheiTeul'g 
Jyttes of die caprst« do not cotisutut^ rcry near upproxiiuu- 
tu the truth.* 

SECTION xxxin. — or iiincic acio. 
iii'4 Jicid was <!i5icovcrpd l>y Clievroul dnriiig his rewarchvs 
itty bodies. But its propertit-s have bci?ij very imperfectly 
obtain it soap made of mutton tallow is to be decomposed 
tartaric or phosphoric iici<i. 'Dio lujin'oii)) liquid Wing dU- 
illfd thi- liircic acid piisurs over with the wtit4-r, XuutndiKC 
1 with hydrate of barytes, evaporate to dryuess, and decompose 
the ki/vate of barytcs by sulphuric acid previously diluted 
wiih its own weight of wiitcr. 

It U n colotirletu liijuiil which docs not coIlg4^al at 32°. It rntmio, 
in lighter than niiter : has a smell analogous to lliat of acetic 
add. It is volatile, very liltle soluble in water, but very soluble 
ID alcohol. It rvddoiiN »tron;r|y Ulinus paper. 

Hircutc of |wtiub is a dcli(|uesn.'nt s;du Hircal« of barytet 
i> not rery soluble in water, and is compot^od of 
Ilircie acid . . 12-21 

Barytea . . . 9*5 

Acconllii^ lu tltis analyns the probable atomic weight of liirctc 
acidia 12 or V2-2h.f 

lliiii ocjd was dUcovcred iu 1827 by MM. Biissy aixl iii»->n. 
L«caiiu. The metliod of obtaining it is as follows : 

• CttSf Wi tW k* tvr/H grM,f. 143. ii Ibtd. p. lAI. 


ciup. I. Castor oil {oleum ricini) is distilled over in a retort, and the 
product of the distillation is boiled with water to free it from a 
portion of acetic acid, and to get rid of a volatile oil with whuJi 
it is mixed. The portion remaining is a mixture of rici'ntcand 
elaiodic acids. Of thb mixture one-third part is to be distilled 
over. This portion becomes solid at the temperature of 50", 
It is to be subjected to pressure between folds of bloating paper 
which will imbibe elaiodic acid, with which it is still contami- 
nated. It is now ricinic acid in a state of purity. 
PrapatiH. Ricinic acid thus prepared is a white solid having a pearlj 
lustre. At 72° it melts into a colourless oil which assumes a 
crystalline texture oncooling. It may he volatilized in a retort 
by a moderate beat without decomposition. It has a strong 
and sharp taste. It is insoluble in water, but soluble in alcohol 
and ether. These solutions redden litmus paper. Its constitu- 
ents when in crystals, as determined by the analyua of Busbj 
and Lecauu, are as follows : 

Oxygen . . 16-68 

Carbon . . 73-56 

Hydr<^en . . 9*86 

It would appear from the experiments of the same cbemistt^ 
that ridnate of magnesia is composed of 

Ricinic acid . . 25 
Magnesia . . 2*5 

This makes its atomic weight 25. The number of atoms cor- 
responding best with these two analyses is the following : 
*=•■»«*"«• 4 atoms oxygen . . 4 

24 atoms carbon . . 18 

24 atoms hydrogen . . 2:75 


But new researches are wanting to enable us to detennine how 
near these proportions approach to the true atomic weight (^ 
the anhydrous acid ; analogy leads to the conclusion that the 
crystallized ricinic acid contains an atom of water. 
^'*^ llicinic acid when assbted by heat decomposes the alkaline 

carbonates. Ricinate of potash resembles soap. It is soluble 
in water and alcohol. It is decomposed by calcareous salts 
and also by common salL The ricinate of soda resembles 
tliat of potash. Ricinate of lime is insoluble in water. Rid- 


Qiip of nM^HV ia insoluble in watpr; but very raIhMc in 
iil«>}iol. The same diameter uppUes to riciiinu> of load and w 
Kveral other ricinatvA.* 


Vn. II. 



This aoA was also discovered by MM. Bussy and I..M8nu 
daring their researches on easlor oil : but its properties have 
bees very superficially examined. It may be obtaine<i by the 
wing proceos : 
The eutor oil is to be distilled and treated va described in 
bst section, till a mixture of rieinic and eliiiudic acid is 
taiaed an there stated. 'Iliis mixture i» to be cooled to 32'', 
id then subjected to pressure between folds of bloating paper. 
rKdaic acid remains while tlti- elaiudic acid is imbibed by 
paper. It U iw Ih' ili«solved in alcohol, ami Jreed from tlie 
(mall quantity of ncinic acid which it contains, by repeated 
erapoTstiona and eryslalliications. 

tulaiodie acid is a yellow coloured oil, con^aling into a solid mpKitait. 
mtm when cooled down a few degrees below 82". It has a 
iharp ta:ite, and basasligtit empyreuinatic smell. It combines 
easily with buises. 'I1ic elaiotiiUr^ of pcitasli and mdn dissolve 
readily in u'uter and alcohol. IIiuni^ of tnagnosia an<) lead are 
ubie in water, but easily soluble tri alcoliol. 
This aci<l is insoluble in water ; but dissolves with fiicilily in 
'alcohol and eUier.f 

■ Tl 

ncnon xxsvt. — op cevadic acid. 

This acid was discovered in the seeds of the veratrtim saba- BWofji 
rfiffo, called ctvailUle by I'elietier and Caveiitoii durin|r ilioir 
examiriatlunof that vt-^tablc substance in the year Ilj2ti4 It 
wax obtained by tJicm in the following manner : 

llie seeds of tlicveralrum were macerated in ether, Uie action 
of which waa aanated hy beat, 'J'bc other when drawn off had 

Eiumed a yellow colour. Tliis liquid being distilled by tJic 
11 of B water bath, the water passed off colourless and left a 
How unciuDiis nuiiicr, insohible in water ami soluble in alco- 
I anil ether. It reddened vegetable bluets and lud a strong 
and peculiar odonr. To determine it* iialure it wa8 converted 
into a soap by Iwiling it with potasli ley. 'I'his soap M'as decoin- 
poaad hy adding to it an excess of tartaric acid, l-'locks of 
unctuous matter sepaniteil wJitdi were composed of oleic and 

* Jour, de FluniMcie, »ii. A8. 

t Ilnd. 70. 

t lUd. vi. 353. 




tartaric aci<ls. Tlio (iltorvd liquid )iad « yellow cnlutir, to^tbn- 
witU un acrid uiid add taste. When subjected Ui distillatioD 
tlicTC came over an aqueous liquid having an acid taste and a 
strong itmell, wliile creain uf tartar and various other vej^taltlc 
)iriiK'i]>U'it rcinniiicil in th(^ rct<>rl. Into tlio liquiil thuK nhtainod 
burytcs wntcr was poured, which destroyed thv acidity of thc^ 
liquid without entirely removing the Bmell. Being evapomtcJj 
to dryness a submance was obtained of a fine white colour, 
cotnjHiALil »r cevadic acid unitiii to ktry t(^s. A ttulfidcnt qaait- 
tity of pho«]ihoric add was added to vutunite the l)«r)-te«, and 
a gentle heat being applied, the cevadic add sublimed, and was 
thus obtained in a separate state. 

Ccvadic acid thus obtained, is a ooUd substance of a fine 
white colour, and crystallized in needleti. It melts when heated 
to the temperatitro of 68". Its smell baR « good deal of resent 
blance to that of butyric add : but is not quite the same. It 
sublimes at a moderate heat. It is soluble tn water, alcohol, 
and other. It combincN witli tlie different bases and forrns a 
geniiH of salt* cidlvd ceivn/atrs, which have been very imper^ 
fectly investigated. They retain a [MirUon of the peculiar vmeli 
which distinguiiOies tlie add. 

niis ani\ approndicf nearest to tlie butjTic and phiwenic;' 
but is suflic'irutly <iiKtiugut»lied by tlie concrete state iit wbidi 
it OJtiatfl at tcmpcralurci! below Gti". 



This acid was discovered by IVllcticr and Caveiitou almut 
the year I8I!>,* during their examination of what they con- 
sidered as the seeds of the latropba Curcas, but which wero 
«ft«nranU fotmd to be tlic fruit of the crnlan tiijlimn, n tre* 
which grows in the Moluccas, and which yields rroton oil, so 
much employed of late years in this country as a purgative. It 
i« a ver>- poisonous oil, whidi hnd been much employed by 
medical men during the 17 th century, but which bud gone out of 
use in consequence of the iinoertainty of its operation, and th« 
fatal efTeets which it produced when given in too large dcM.>ti. To 
ubUiin cmlonic acid, the cioton seeds are digested in ether or 
alcohol. TIiv infusion being distilled leaves a combinatinn of 
oil and crotonicacid. 'I'hi^ oily nuittcr being boiled M'ith wnler 
and magnesia to dryness and digested in elher. the oil iAremove<t, 
and tliere remains a combination of crotonic ad^l and inagnes 

* Jour, dc Pliannocic, n. S8II. 


Mr. II. 

whidi being mixed willi phosphoric acid, and (Uittillo<),CTOtonic 
■aici possM ovrr. 

Bat bjr thi» proce» very tiuk' crotonic acid in obbiined, 
bcanue no«t of it rcmuinii uniccd b> the oiL Tlie l>est way of 
pnorodiitg, tbereforc, u to convert the oil into a soap by Ixtil- 
io^ it with potiub ley> The soap in to be itfcoinposed by lar- 
loric scid, tiiu liquid l§ to be filtered and distilled in a we\l luted 
■p|NU*tiu(. Tlie liquid that pasnes ijver. ntid wlik'li cont»iii« 
Ike ootonic acid, is to be iii^utniliz^'d witli )itiryteii vnitrr, mid 
mfMrsIed to dryness, 'llic cmtoiiate of baTytea bein^ now 
■bed with liigldy con con (rated pbosphoric acid and distilled, 
ike crnioiiic acid in subliiucd. 
Crotoiiiv iicid thuit obtainnl con^ealti when cooled down to i^i>i<tii«. 
When heate<l a few de^ree^ above Hi" it stihliniet* in a 
r, bavirifT a stroii); smell, and acting pretty Htrnii^Iy on 
tMWtrilj* and eyes. It reddens litmus paper. The taste is 
and iu pf(iportie« ane very poisonous. It diwolves in 
watrr, idvobol, and etlicr. It is doubtless tliiei Nubatance wliich 
givvn to croton oil its cathartic and pnijioiimiH <|iuilhit^'i. 

CrotoHolt iifpotaaii crystallizes in rliomboidul prisms, which 

not altered by exposure to tiic lur. It dlMolvcK with rlitii* 

ty tni»lcoh«»iiil'tlioH|ienficgnivi(yO*85, Crotoiiateof barytea 

lublf in wHt<-r, and niu-ii tlie solution is ovaponitcd, oitlier 

pvnrly cryatold, or tails in the state of a while powder. 

.to of magnesia may be (ibiaiiied in sninll f^rains very 

uble in water. Crot4iiiat(' of aininoiiiii prrdpituU's iron 

the sulphate of an Isabella yellow colour. It precipitates 

iko «lta of lead, copper, and silver white. 




' Amberipis is a substance founil flniitiiig in the t>ea, xntrnt 
rntnimitily near (ke coasts of India, Africa, and Brazil, usually 
I anaaJI Jiieocis but M>m«limes in masses of 50 or 100 pounds 
rigbL It is i^nvmlly considered an a coticrt'tion fornietl in 
intestines of tlic phyneter ntiicrocepluiluii, or tipermaccti 
lie. It is a soft sub<^tHnoe, which swims in wntt-r, hiiviiw 
1 1^ f^T*7 colour with brownish yellow and white sIrculcM. It 
extuiiinctl in cnnsiderablc detail by Douillon La Gnutgc.* 
extmded from it, by means of alcohol, a white sultetJincc, 
which hf gave the nnino of oiUpocin, becaiu>e lie coii.tidered 
an the same with the subHtiiitec which makc« its appearance 


* Aait lie Ctiim. xliii. TS. 

tid I 




<**!• when de.-wi bodies in gicut numbers putrefy together, and 

wliieli the name mlipocire lind been given liy Ftiurcroy. But 
being exBtnitied in 1820 by IVlletierandQiveiitmi, th«y f«und 
reason to consider it as s peculiar substance, difftTcnt from every 
other. On iliat account Uioy diiiuiiguished it by the name 

Ambreine is ca»ly obtuinc<I by digesting ambergm in hot 
aMiul, of tlic specific gravity O'SiJ?, filti-riiig thi- liquid, and 
lejiving it to itself. The ambreine is lU-pnsiu-d in a kind of 
stulnctiticul state, retaining; a great deal of nicoliol, which may 
bo driven off by evaporation, when the bulk of tlio nmbreine U a 
very much diminished. It has a fine white colonr, is tust^-lcMf ^ 
and lias at first a sweet smell, wliich is dis«iputed by repeated 
cryMtjitlizatiuns. It is iimoluble in water, but dissolves readily 
in ether and alcohol of the temjicntture of 50*. It does not red- 
den litmus paper. It mellj^iit t*6'. When heated above 'il'J' 
it become-* brown, exhitU's u white Asmoke, luid tt partly decom-^ 
pose<l. Tho white nnoke contusts nf ambreine uiialteied. I^fl 
is inaipid>Ii: of forming soap with alkidien. 

Pelletier and Caventou found that when treated witli nitric 
acid and heat it dissolves and svells, while abundance of deuu 
oxide of azote is driven off. The ambreine becomes firtt grpon 
and llien vellow. It i» now c^iivcrti'd into a peculiar acid, to . 
which Pelletier and Caventou, the discovervr^ have given th«S 
name of ambreic acid. •^^^ 

To obtain this acid we have only to heat (unbreinc witli nitric 
acid till it ceases to undergo any liirther change. Then eva- 
puntte cantioiiHly to dryneM ; wash tlie dry ma.sit with culd water 
to remove an much of the acid an potwiblc, tlien l>oil it with u 
lilllc wirhoniite of leaH. If we now wash it with cold water till 
the solution ceases to retain any truces of lead, we are certain 
that the nitric acid has been completely removed. We have 
Mily now to digest the residue in alcohol and set the solution 
■tide ; the ambreic acid cr}-MtalLixe« in timall plates. 
PnpMiih Ambreic acid when in masses is yellow, when mucli divided 
it appears white. It has a peculiar smell, quite different from 
that of ambcrjiris. It reddens litmus paper. W'lien heatetl, it 
is decomposed without furnishing any iunmoni.'t. It remaius 
Holid when heated lo'2l'J°, while cholcstcric acidfoses ut 136% 
Thin constitutes a striking distinction between them. 
m. Ambreic acid is also much less soluble timn cholcsteric 

' Jour. (Ic Phnrmncic, ti> 40. 


and ^li«r. It is soluble only to a very small oxtrnt in 

■nUt, though ho* water cItSMtlvc:* mort- of it tliiin coW water. 

This acid omnljine^ witli liuKCr*, iind forms a gvims of salts called 

amtreatfJi. With potUAli itcomhincs in two j>ropnrtionH. Tiie 

binambreate is insoluble in water, but soluble in alcoliol. The 

DTutnil auibr^ute disMolvc-J< iti water. This xtlt tlirow^t down 

fellow pTPcipitutrs when droppwl iittu solulioni* nf cliluride of 

^Le«U.-ium. eliloride of i>iirium, 6iil|ilintc of copper, sulphate of iron, 

^■kitmte nf siUer, acetate of lead, cbloride of mercar)', of tin, and 


No altomptA }Mveb»on made Ui di'Ioriniue the atomic weijjht 
of thia acid, or to niialyite it. But it is obvious from tliv phe- 
nomena of tta decomposition that itji only constituents arc 
■asygen, carbon, and hydrogen. 



tllv. II. 






Poulli'tier do la Sidlv firtt examined one of the most common (niuimcrinB.' 
cpccirs of biliary ndtruli, lUid by nwaiu of alcohol c.vtructfd a 
Aubstailc«in plates, somewluit like jc/TrnNnrr/i. Fonrcroy 
eoiiiiidering it as aiudogous to the soapy matter 
iA from the dead bodies which had been left in great 
iBubcrs in pilM in the hnrtjd f^round of the Inuocent^ in Pari.'*, 
ua that acc-utnit calU-fi it aiH/iucire. Chevreal cxiunint-d 
1616, sliowcd tliut it pntH-wrs peculiar properties, and on 
MCOnnt gave if the name of clmlfstcrim;* 

coQtinu«s twltd till healed up to the t^roperature of 27R', rropcnkit 
n it ini'lU). Oil being allowed to eonl it crystallizes in 
late* nwiiuUni; from a c^-ntre. It in tasteless and deMitutv of 
*ll. It is iuNuhible in water, hut 100 parU of hciitin^ alco- 
of tJie BiK-citie ffrnvity 0-Sl 7 diwolvc 1 8 pjirt* of it, hut on 
liu)r, the griiile»t part of the choleatcrinc is deposited in 
brtlUant Males. It lias no acid properties, and is incapable of 
■inji converted inu> soap when boiled with the alkutit^''. It 
composed, acwiniing to the aiialyuls of Clicvrcul, of comjBrtUoo. 

Oxygen . . . 3-025 

Carfwii . . . P5-095 

Hydrogen . . . 11-880 


iow tlte smallest number of atoms tliat correspond with these 
irtiuiu a tlie following : 

■ Vnm ;^q il>'^)t onil ^'f"> (taSii). f Sur lot Corps gru, p. 1^ 



'^•9-i- 1 atom oxygen . . 1 

38 atomg carbon . . SB'S 

32 atoms hydrogen . 4 

So that the atomic weight of cholesterine cannot be less tbao 

Pelietier and Caventou ascertained in 1817 that when cho- 
lesterine is heated with its own wei^t of nitric acid till no man 
deutoxide of azote is disengaged, there separates a y^lov 
matter which possesses acid properties, and to which they gave 
the name of cholesteric acid. When the acid liquid is diluted 
with water, an additional quantity of cholesteric acid separates. 
By repeated washings in water (in which it is scarcely Mluble) 
it may be freed from nitric acid and rendered quite pure. 
^Sj"*** Cholesteric acid has an orange colour when in mass, but if 
we dissolve it in alcohol and allow it to crystallize, we obtain it 
under the form of white needles. Its smell is somewhat analo- 
gous to that of butter. Its taste is styptic, but exceedingly 
slight It is lighter than water, hut heavier than alcohol. It 
melts when heated to 136°. At a temperature somewhat higher 
than that of boiling water it undei^oes decomposition, being 
converted into an oil, water, carbonic acid, and carburetted 

It combines readily with the bases, and forms salts call«d 
cbolesterates. They have all more or less colour. Iliose of 
potash, soda, and ammonia, are very soluble in water and ileli- 
quescent. They do not crj'stallize, and are insoluble in ^oobel 
and ether. All the other cholesterates examined are very Ikde 
or not at all soluble. Cholesterate of barytes is red, and vaj 
little soluble. It is composed, according to Pelletter toA 
Caventou, of 
Atomie Cholesteric acid . . I6"S8 

Barytes ... 9'5 

Cholesterate of strontian is insoluble in water, and has an 
orange colour. According to tbe analysu of the same chemists, 
it is composed of 

Cholesteric acid . . 17-57 
Strontian ... 6*6 

The cholesteiate of lime is very little, and that of magnesia 
not at all soluble in water. The cholesterate of alumina has a 
fine red colour while moist, but when dry it becomes darker 
coloured, and has lo«t its beauty. 




CboleMcmte of lead ia brick rm), aiii) b compnsed, according 
to tite Biu]y«e« nf Pellctirr iind Cavcnuiii, of very nearly 
' ChoU-sti-ric acid . . 20 
Osidc of Irad . . 56 

Notr 56 represents four atoiDS of oxide of lead. Tito Hslt must 
therefore lie n tetraki-cliulpsterate of lead. 

The iitoinic wciglu of cLulcnt^ric acid, deduce<I from the 
dirve preceding analyses, ranes loo much Co admit of any very 
aocunite deductions. By cholesteratc of lead it is '20, while 
dmlniteiatc of barytcs makes it only lfi-88. The meati of the 
llitvo luuily'*)^ muke^ the atomic weight ld'15. Probably 
crrforc it is about 18, 

Whet! cbniesteratc of potash ia dropped into nitrate of mer- 
ry, a tilnck prcdpitutc fiillx, while with the pernitnite nf 
iMvury the prccipitnte is red. W'itli copper Hiltx au olive 
precipitate is obtained. The choleHtcratc of zinc has 
fine red colour, and is little soluble in water,* 


IXf. IL 


In the year 1626 M. Bimp inserted a notice in a periodical HUMrf. 

,t that he had dkcovered ptHic acid in the rwn\ culled 

I, crytUallized in trianguhir |>lati>s, soluble In 4 limes ltd 

t of alcohol, but insoluble in water, white tlie resin of the 

nun rtAt>« yielded anotlieracidcrystallized ins^tiareplates.and 

bic io 7J timcJi itn weight of alcohol, to which lie giive (he 

of atielic acid. He Htatcs iiotliing fnitlior reHpectitig 

ucmIh ill lii» xhort notice above referred to, oo tluit it is 

ipoMubIc to uy whether \i\n acids be tlie game aa those of 


Unverdorben bad been occupied with the examination of 
for several years. He bad sbowii, at least a» euily as 
the yew )825.t that colophon poemsses the cbaructcnt of lui 
unA. His account of pimc acid api>earcd in 1827.} He has 
■kowii tliat resins are tliviaible into two sets, namely, thoso 
which have acid properlicH, an<l tltose which are indilTeront. 
rcNiiis from the piur tribe lieloiil< to the firsi set, but. they 
■fere seldom pure, beiiifrgi-nenilly mixed wilh fort^igii bodies itml 
iritli resinous substances which are indilTeront, Piaic acid 
ly be procured from cofophoH or common white resin, and 
coaiBion and Ventiiaii turpentine. To obtain it pure, we 
y prorvett as follon'H : 

• Ann. <l« ll.i.1.. « dc rtiy*. vi. 401. f Ibi<l.ix»i. 109. 

t PoGKC^'ilorf'i Amialcn, ni. 311. anJ viii. 31^. +''7. i Ibid. iii. 47. 

II. L 

^■-fere I 


Distil Venetiiiit turpentine with wuter, frequently renewing 
' tliat liquid, till hotJi tlio more itnd less volatile oil of turpentine 
has piuuiecl over. Dissolve the residual resin in nicoliol, nti*! 
mix [lie li(]iii(l with a solutioj) of acelJite of copper in aleohol. 
Pinntc of copper precipitatcH, ^v-hicll must be collected on nfl 
filter and wathed with abKoltite alcohol. Then dtssolre it in 
aleohol eonlaininir muriatic acid, itnd mix the solution 
with its onii weight of v.'ster, Piiiic acid fidU down, hikI it 
to be freed from ulculiol by boiling it in u'aler. Pinic acid ^ 
thus obtained slitl contains mixed with it & &mall quantity of^| 
resin not soluble in alcohol, 
rnpviuth Piuic acid is hard and brittle, and becomes electric when 
niUied. When procured from turpentine it is transparent and 
coloiirlew^. It haK no »inell, but Ih di-'itingiiished by a bitterish 
taste. M'hen fused, it ast^umcs » brown colour in eonscquencc 
of the formation of cf^ophonir acid. By an iucreinse of tlie heatfl 
it flows thin, and when made to boil, at least one-fourlh of^* 
it is converted into colophonic acid. When distilled in it small 
glass retort it gives out a little carbonic oxide mixed with ear- 
bureltcd hydrt^en gitst, with a yellowish tar, owing to the 
mixture of resic acid and a little u'aler. Tbitt water contains 
acetic acid and a little resin, with vohililc oil and odorin. The 
tar contains acetic acid and some cohptionk acid, mixed with 
much pinie acid. When the distillation takes place in a large 
retort, almost all the pinic acid is decomposed. 

It is insiihible in water, but soluble in alixihol and ctlier. ItJ 
dissolves also in btsulphurct of carbon. It dissolves ahra io] 
concentrated sulphuric acid, and is ngain precipitated by water. 
It dl'-fiolvcs also in oil of turpentine. When fused with the 
alkaline carbonates, it drives otT the carbonic acid very rapidly. 

Pinic aciil acts pretty powerfully as an acid, but in order to 
judge of lb* activity it miiiit be di^olved in ether. If to an 

lerial solution of pinic acid we mid curbonalc of copper, tlie 
nic acid is grndiuiUy driven off with an eflervoscence, and 
oxide of copper dissolves in the solution. When acetate 
of eop]>er in tine powder is Rd<lt'd to such an etherial solution 
Rt the temperature of 60% the salt li graduidly decomposed, | 
ami the oxide of copper combining with the piuic add colours | 
the liquid ;jreen. Pinale of co|)per i* d(-oompo«ed by muriatic 
idd, '>ulj>huric aciil, nitric acid, ami ])hir^)buric acid. The 
carbonate, acetate, and most of the volatile vegetable add com- H 



pounds of oxide of copper, are decomposed by pinic acid ; but 
the sulphate, nitrate, and pbospfaote of copper, ore not altered 

iti:i(-(i ^1 



it It M earioiut that tite etherial solution of pinic ttcid does 
art ii|>oii black oxiile of cojtpcr ; at leaat it Hcarcely aci|itirm 
gre«u colour after some woeW <]ii;eslii>ii: iit^ttlii-r do^s it 
irapOHC or (liiwolvc nrlKiiuiU' uf timi;. But act'titc of lime 
mulily dccoa)(>oo<-<l by tite idcoholic eulutioii of pinic acid. 
Kriate of lime k imperfectly de«itnpa«od when fused with 
acid. Ari<l the wiine remark applieti to muriate of innp;- 
■Hik. Th« oorimnatcs of potash and soda arc very readily 
pMcd when boilfd in a solution of pinic acid in oil of 
I) tine. 
AtNMic acid partially dt-compoxoK piiiat<> of cop]>cr. There 
ieDoitia a mixture of pinic acid and pinatv of cupfwr. But on 
etbar band pinic acid, in the state of n fine powder, deoom- 
ttoetalc of copper : acetic acid is disengaged and pinat« 
copper formed. 

Pinic acid combines with the different ba^eti and destroj's 
alkaline qualities. T)ie pinaies formt-diu^ usually neutral, 
resemble reitin in their ii)i|iearatii-(-, and nunc of tlicm arc 
le of crj'stallixin^. They ore soluhle in alcohol and ether, 
the alkaline pinutes also in wutor. Tlic alkaline pinatca 
be formed by dif;e»tiitg the solution of pinic uctd in ether 
an alkaline carbonate. The earthy luid metalline pinates 
dcMibl* (lecoinpoMtion by uddiiig a solution of salt containing^ 
baM to a solution of pinabe of potash or soda. 
Unverdorben nuaijzed several of the piiiates in order to 
lermiuc tlie atomic weight of pinic acid. The results were na 

1. PmaU: of Limt. 
Piniencid . . 07-64 

Una . 9*5 

2. Pittale of Moffnrgia. 
I*inic add . . . 67-3 
Magne^a ... 2-5 

3. Pinate of barges, 
PEnicacid ... 78 
Borylet ... 9-5 

»!•. ir. 

A unit 

• naae analpa are dcrireJ from the Kiniviuents oT l.eopold Omdin in 
b Bandbucb der Th«an;tMi-l>«n Cljeinif, vul. ii. p, 5S3, tee. They tm 
I by UfiT<rdariica while giving ho iici-uunl oftht combiiiiiiion of colo- 
I «^tli iMWn, Po^ndorTii Annnlm, tii. 312. Onii-lin uyi that Uiiver- 
I hhnMirram the elomic weight of pinit acid at AO'S, but I ilo nM 
f fron what data he has drawn hit conduuoiw. 


4. Pinate t^soda. 

Piiiic acid . . . 


5. Pinate of potash. 

Pinlc acid . . . 65-7 

Potasli ... « 

The pinates of baryWs antl sorla deviate so fiir froin the ol 
that we caiinot include tiit'in. 'rh« inoiiii atomic w<>i^l)t of] 
pinic acid derived from tlie others \% 66-95. Wo may, tlicro- [ 
fore, jiitch iipoii 67, as not fur from the truth. 

OfCdopkonie Acid. 
■■M^h Colnphon xi the name ^iven on tlie continent to tlie brown, 

brittle, Komitninvpuront rettin, which remiiias when turpentine 
baa been subjected to distillation in order to obtain oil of tur- 
pentine. Unveniorbcu first showed tliot it wan eapable 
neutralizinfT alkidinp bodies, and tlierefnre po^aiesxed prnjx'rtii'* 
analogous to acids. Indeed as it has been lon^ employed in ihia 
country in the niaiuifiictory »f soiip, thi)« inference mijrht hav« 
keen very naturally drawn, tboufrh 1 am not auiirc that any 
chemist in this country actually drew it. From Uiiverdorben'* 
experiments it appears that pinic arid when stronglv heated 
l)eeom<-s brown, and is partially converted into colophonic acid. 
Coloplionic add seems, therefore, very closely connected vhh 
pinic acid ; and l^nverdorbon has nowhere pointed out in what 
the difVcrence between them consists. Accordiiifr to tJie analysis 
of Giiy-Liissac and Thenttrd, colophon is composed of 
Hydrogen . . 10-719 

Carbon . . . 76-944 

Ctygen . . . 13'337 


which I'nTenlorhen, from bin experiments on the atomic weight 
of colophonic ncid, has resolved into 

119 atoms hydrogen . . 14-673 
fiS atoms carbon . . 51*75 

9 Rtotns oxygen . . 9 



This would make its atomic weif^ht 75-025. Ilut the atomic 
weight derived fnim his analyseH of several colophcinatcs conctH 
nearly to the same number as that given in the last section for 
pinic icid. In fact the data from which that number was got. 




the nimlyKU of coiophoiuitos. Now iho number of 

eom-)>iKiriding wild the iitomic wvlf^ht of 67, utid wiUi 

I Ae wuilyBts of colophoa by Gay-LiUMc uiul Tlieiiunlf m« 
04 atoms liydrogcii . , 8 

67 atoins cariM>n . . 50*^5 

9 atomii oxygen . , 9 


This, tberefore, ouglit to repreiiPnt tlie ittomtc conaiituliou of 
eolapliuuic acUl, uccordin^ to tlio data furnUbed by Unver- 

M. l^ivenlorbcti states tbat colopboD ia not pure colojiboiiio 
arid, but tbat it is cootamiiiated by a inixlur« of an indiffcrvnt 
min. But he ha.4 uo wliere (riven a proccst by wbicb it nuiy 
be purified. 

W'beii ibmu'ti dou'n from an nlkitlino solution by means of 
add, it it) ill the state of n bydniti', composed of 100 colo- 
ao and 13-1 water. This ts very nearly 

t atom colophon , 67 

6 atoins wut^r . . 9 


sKcnoN xLi. — or silvjc acid, 
Tbiti aod forms one of the constituents gf the common lur- hw«a 
»tiiie which exudes from the pinut siktMrU. IIenc« the 
given it by ITnvprtlorben. He cotuidert it a» idenlicid 
rilb the crystalline HUJMtanee which Kii>«:« met with in white 

C'icb,* oiul iikcwlte with tlte alue lie- acid of B»up, mentioned 
the Um wctioii. It may be obtained pure by iJie followinfr 

Mix commou turpentine with water, and distil to get rid of 
the volatile oil. Difjvst tlie residual mutter in eold aleobol of 
the specific i^rarity 0'B83, wbk-h will leave undUsulved most 
•f the silvic ad<l, mixed with u small qu»ntity of pinie aeid. 
Then boil tliis undbwolved residue in twice its weight of iiU-ohol 
of the specific gravity 0*883. j\e the solution cools tlie silvic 
•till precipitates utill mixed with aliout four per cent, of piiiio 
■dd, but from thi.i it may be freed by repeated solutions in thi! 
beiBi^ hoi alcohol of 0-883. Or if the preci](iiate be digested 
lepenteiUy in cohl alcohol of the sjieeifir f^viiy 0-t^^ tliepiuic 
acid will be dissolved, ii'liile tlie greatest part of the «ilvie acid 
* J»lti1)UL-li <ics Pul^icclini«chcn Inttiliita ni Wicn, i. 4S6. 


caw I will rcmaiii unaltered. lint the ».'a»ic«twi»y of obtninin^ it pure 
is to tliwolvv the impure add iii twit-c its wi-ight of absolntc 
alcohol, containing j^th of its weight sulphuric acid. Wheo 
tlic solution cooU tlie silvic nvlil Khoota into large cry«tul8, free 
fniin )>inic and Kiilphunc ocid, provided lliey be wii»hc<i iu 
ulctihul «f iht; Kpccilic gnivity O'SBIJ. 
rnvtnks. Silvic acttl is trdnspurvnt otid ccilourle»&, and has tho form of 
low foiir-sido<l prisms, tcrminatc<l by a four-sided pynuni<l. 
When hontcd it mi'lls into u colourless mans, willionl any 
appouraiicA of crystallization .When scratched- with u hard 
liody it breaks H*itb a slight cnick, us happens nhto to piniu 
acid, tt is nearly as hard as colophon. When nibbed it 
becomes electric. When healed it become* soft and thro-iwly. 
It iases nt llie Icmperuture of about SIS*. 

It is insoluble la water, hut ilissolvcs in alcohol and «ther. 

M'heii heated to rWH" it gives out no water. When raised 
to a higher temperature than this in a retort, it become* lipil 
thick and tlien quite fluid, given out a little water and irmpy- 
retimatic oil ; it then boiU iinii gives out no more water, hut is 
converted into oil at firtit limpid but heeoming graduiilly thick, 
while at the same time a little gas b* disengaged. If the 
process be stopped when two-thirds of the matter has passed 
over the renidue i» light brown, and consists of a mixture of 
silvic acid, pinic ticid, a little resin simiW to pinic acid, ami a 
neutral resin soluble in absolute alcohol, from whieli it falb 
when left lo spontaneous crystallixallon in colourless crystalline 
Socks, M 

When silvic acid t« boile<l in nitric acid, tt slowly undergoes B 
decompaction, being changed into a yellow resin, which when 
diaiolved in alcohol stroi^ly reddenis litmu.t {naper. I'hift 
altered resin posseeses also tlie properties of an acith aitd com- 
bines with tlie diRerent bases. Silvic acid dissolves n^dily ia fl 
ftnl[^iuric acid. The solution U yellow brown, and wuter 
throws down from it a mixture of a little silvic acid with H 
great deal <^ pinic aci<I. 

Silvic acid may be obtainetl in the state of a hydrate by: 
tltrowing it down from iu mlution in potash by meaits of aj 
stronger acid. The water does not separate unless tho sUvto] 
acid be mixed with o.xitlv of lend. 

Unrerdorben, to whom u-e are indebted for all the Gncts] 
napecting this acid which have beet) stated, examined also a 
nmnher of the W/rWfjt, and determined llielr properties. Bui 
as lie made no attempt to aiudyite any of these nils, we arc 

c stJUfl 



i^onnt of the atomic weight of tliu avu). 

It m doubtless "™ '- 

It Win dtscovcrvtl by IlauMtnann in 1788, tJiat wh«i) tW/j^o "i»«t. 
k m-at**<l wiili nitric acid, ii i« conrerted into a jellow colwurcd 
ud IniUr tasteil aub«>Uui»>, wtiicb hiv l>eeii ever since known 
bjr tbe name of Oitter principle ^indiijo,^ It u'as afterwards 
nwniiied by Fourcroy and VaDqucltn-l And iit a Still lalter 
period by Ciievreiil.J wlio i?ndcavuurv4l to hIiuw dial it Mit-t a 
compound of nitric ncid witli s peculiar priiici|jle drrivifd from 
I buli)^ lu 1827 an elaborate set of cxficrimcnts was nuuli; on 
hk by M. Licbi);,! trbu demonstrated it to be a jicculiur acid 
[oompOMd of azote, airboii, and oxygen; but without any trace 
[of tiilric acid, and to which lie gave tbe name of atrbasotie 
\ocid.% Ilia mode of obtaining lbi« acid in a state of purity 
I was asi fullowit: 

llie bvKt iod^^ reduc4-d to a coarse powder h digested with 
I'R^I tit ten tiiiien its wi-ig)it of nitric ncid of mean otrength at 
rcry niudcrutt! tcm|M'Tittiire, It dissolves witli a copious 
^•mission of nitrous fitmi-^ while it froths up very considerably. 
j After the violent ebullition is over it is raised to the boiling 
I lempeiature. Then a little more coiicentmted nitric acid ts 
[luhled, and thw ii perwsied in as long a-* tliere is a diseii^nt^c- 
I mcnl uf red ftiin<.-s. When tlie lii(ni<l It-xt couU-it llu-re uill lie 
tllepuditcd a grt'al quantity of yellow-coloiired nemitninsparent 
[crvstals : and f>nppi>%ing ihe proci'wt properly conducted, neither 
[ri^iu nor nrlilteial t:uuiin ni.iltes itt iijipeiu'ancc. Wcish these 
[crystals in co]<I water, mhI dissolve them in boiling water, and 
' eryntalltze a second time. To obtain the corbazotic acid quite 
i iiurr dUiotve these crj'stals again in boiling water, and .taturate 
Itliom witli carbonate of poIafilL On cooling c:irba/.otatc of 
> potush crysLiIliseft. It \s best to dt««olve these crysstal.t again 
in watrr, aitd to cryHCalline tliem two or three limes succe«!uvely. 

I When thecarliaj((>l;ile of pntiish ts Buificiently pure, dissolve it 
in water atui decompose it by nitric, muriatic, or sulphuric acid. 
Wben the tolntion cools beautiful crystals of carbazoiic acid 
ore deposited in pliiti>!i. A good deal of the siune add may be 
obtainetl from tlie mother leys by a similiir process. I'ourjMirtS 
of Indigo yield about one part of carbozotic acid. 

• Unvcnlorticii. Foggeiidort"* Aunalcn, \i. 303. 

t Joor. d« Ptij*. Man. 1J8M. 
{ Ann. ik Chill). Kxii. 1 17. 
1 KMeutkhUifitttii*. 

t Phil. Map. jxli!. 950. 

II Aiui.ilcCliini,fld<;Phyi. xssv.llt- 




Carbazotic acid tliiu obtained h crystallizpd in fine (lUitm, 
liaviiig a silky lustre aiid a fine yellow colour. Il rvdJcnn 
vegi-Uilile blues, and lia» iin csct-cdingly hUter laste. \\'Iicn 
bi-iitt-d il melts, und k volutiiixod without decomposition. 
When suddenly liratcd it hikes fire nnd buruH wiili a yellow 
flame, lennng a residue of ciiarcoal. It is Httk- suliiblf in cold, 
but very soluble in hot water^ and the §olution hiw a deeper 
yellow colotu- than the solid acid itself. It is soluble also iti 
alcohol and etlien 

It is not acted on by chlorine or iodine. Sulphuric :icid liiM 
no action on it cold ; when hot it dissolves it ; l>ut k-t« it Tall 
utiultcrod m it cooIh. Itoilin^ muriatic acid has no action on 
it whatever, and nqua re^ia scitrcely alters it. These faet>) iiT^ 
Hiifficient to Ktiow tliut it conuiins no nitric acid, us Chcrreul 
supposed that it did. 

It iH nithcr a powerful add, uniting n-itb and neutralizit^ 
the different Iwises. The carbuxotules Imvn ihe curious pr»[K'rty 
of detonating when heated, as was long ago discovered by 
Fourcroy und Vniiquelin. 

I.ietiig examined a good many of the carbazo tales, and sub- 
jected earbazotate of potash and of barytes to analysis, 'llie 
following were the resuitii wbicb he obtained: 
1. Oirbazutatf. ofpotaitk. 
Cttrbuzotic acid . . 31-0I 
Potusli ... 6 

2. Carbazvtati; oflHiTyU*. 
Carbazotic acid . . 30*41 
Barytes ... 9*5 

The menu of these two analyses gives us ;I3(H7I for the atomic 
weight of this acid. It was analyzed by Licbig by means 
oxide of copper, and found composed of 

Carbon . . »2.1920 

Azote . . 1,5-2144 

Oxygen . . S-i-awW 



The Iiydro^n, supposing it to contain that principle, scarcely 
exceeded I per cent, of the weight of the acid. 

'Ilie number of atomti corresponding nith tliis analysis is 
10 atoms carbon . . 7'5 

2 atoms azote , . 3*5 

12 atuiitn oxygen . 13*0 



But this wobM make tiic atomic weight onlj* 23, which docs 
Dot a^ree with lliat deduced from the aiialyf^ii of tliv curbnzo- 

tTo tuake them agree wc niusl su[>]>iMC 
\'2i atutns carbou . , 9-375 

U« atoni.1 atote . . 4-375 

la atoms oxygen . . 16- 
figiproAcbea near»l to .10-41, the stumic weight deduced 
trviii tlie aiiidyxix of cnrlKunEiiti! of hiirytcs, 

Uut Ur. Buff, wlio hiv> |>uhli&Led i>cveral interesting papers 
DO iadigo, BtHures ui that Liebig a^erbtined tluil curlsuotic 
is n compound of 

16 atoms cuthoii . . 7-5 

4 atoms oxote . , 7*0 

10 atoniii oxygen . . lO-O 




.where tJib detenniiuilion appeared I do not know. Il is 
ly incuuiiiailrnt witlt Lii-bi^s unalj-sls of the isirbaxotatcs, 
of carliazotic ncid.f 

TTie existence of this acid »ils first jjointeilont by Chcvreiil iMan- 
m his paper on llie action of nitric acid on indigo ; but for the 
fint acooont of its nature and properties we are indebted to 
Dr. UuiT.J Fourcroy iii«i Vautjuelin )uid indccn) olwerved it, 
bat ihey nmtook it for fienzaic acid. TIk- rnrtliud of pn-piiriiig 
be ini/iffotic add is as follows : 
Very dilute nilricaddtsmiM-d to the boiling point, and indigoiit 
ne powder iutdi.*d by little and littlir. A con»idcrul(lc frotliiiig 
km pliice, the colour of the indigo U ininic<liiilcly di-stroycd. 
adi^o is to be itddcd us long on thi^ efi'ervi-scvnce coutiiiues, 
king core to prevent the concentration of the aciil, by uddiiig 
now and tht:n a little boiling u'aler. The giui ex-olvcd 
Mod of djiuil voluini-s of citrbonic acid niul deutuxide of 
The yellow coloured liquid thus obtitiiicil wn.'^ ^epurvted 
liot, from the resijious mutter which lutd been deposited. 

- Ill 
j^ t W, 


• Ann. de dunk et de Phyit xixix. iOG. 

t Wcltcr'aUltcrpiricidpIcoblaiiiciJ b; Jigntingiiilk in nitric adil, appear* 

MB Liebif'a cxpcrimcotii to be niao tarbniolicaM. Bu[ tilk yields a much 

■■Ucr (jnantily of ibis adil ihaii tndigo. 

I Ann. de Cbitn. ct dc I'hys. xuvii, tt>U ; u^in. SEN) i xU- 174. 


**^^ On cooling it let fiill indi^otic ncid in very ill formed crj'stjiU, 
The iniligntic iinil thus ubtaiiicd Win^ still impure ia (o be 
pr»'9»cit lictwfi'u l'otd§ of blotting piipcr, to free it fnim nitric 
add as completely aa powiible, and then dried on tlic w«tcr 
batJi. Hot water now ilLiMtlvoii indigotic acid, and leaves » 
quantity of insohiMo nuittcr Ix-liind. The ntjueous solution 
(which is very dilute) is to he mixed with recently precipitated 
Cfirboiuite of leiul i(ui4pendod in wnter, liikinjr euro to stop when 
the eifervejiconce (wt first strong) bi-jfin* In iliminish, and tha 
liquid cciisi's to be tnintipareiit. Unlciw this preciiutiou be 
attondv<l to, much of the acid prccipit»te» in the ^Uitu of diii- 
]ndigotut^-of lead. The liqiud is now loft till the impunlic* lidl 
to the botlom. The tmnsjiarent liquid being <lrawn off con- 
Biata of a solution of j)ure indi^otale of lead. Tlie Iciul being 
separated by sulphuric ncld, and the solution concentrated, 
yields crystals of pure indigotic acid, 
rnprnin. The crystids are »now white, very bulky while moist, but 

tliey diminish very muck in volume, and lose their crystalline 
appt-uraJice when dried. Tlie lustre is that of itilk, antl th« 
colour exceedingly uliile. The indigotic itciil has u wcukf 
acidulous, and bitter tUKte, It slightly reddens infusion of litmuii. 
10(10 purts of colli wurer dissolve only one part of tijis acid ; but 
boiling water dii^solves it in any proportion whatever. The 
solution h colourless. It is volatile. When heated inaglaas 
tube it melts and sublimes without decomposition, giving out ■ 
diarp acid smell. On cooling it crystallines in ^x-fiided prisma. 
When heated over an open flume it takes fire and bums with 
* strong flame and the evolution of much smoke. 

"When digested in concentrated nitric acid it is converted into 
Carba/otie acid. Dilute muriatic aiul sidphuric aviil* linve no 
action on it; but M-hen heated in coneentrated snlphurie acid a 
brown coloiured solution is obtained, from which water throwH 
down brown flocks. It is not decomposed by chlorine, imr 
altered. Nascent hydrogen is absorbed by it, and it !issunK« a 
copper-red colour, iind bluish-red Hocks are gradually thronnt 
down. Indigotic aeid gives u bloutl-red colour to the soluUon 
of peroxide of iron. 

In order to determine the atomic weight of this acid, M, 
Buff anulyxed five diiferent combinations of it with oxide of 
lead ; but the results varied so much that there could be no 
doubt tliat every one of the salts examined contuiin'd u mixture 
of some of tlie others. The two thui seemed to be the puruNl 
were obtained the first, by dissolving a tittlfi carbonate of lead 







Div. tL 


[io « groftt tleal of indii^tic aind, and setting the solution wide. 
|.&«BltnuiH|iaivtil yellow needles were dcpoMtcd, wliicli were 
rirvetl fram all adheriiif; indigMtic ackI, liy digesting Uiern iii 
vhol. 'Pbeee cryiitaJs are Kuluhle in w-jiter, Uut are lU'cum- 
at the nine cime. 1'bey iirv iuiby<lrouis and composed of 
Indigolic acid . . 2ti-71 
Oxide of lend . . 14 
Th<> tidier <ail( vnu obtained by pour!n<r a solutinn of nitmte 
^ricMd iiitittndtffotattiof poliisii, raLsivllualHiiling tein|iemttin'. 
Tb« liquid reinui»»d for gome time tntnftpareut, but fine deeji 
yellow ueedlw gradually felt, whicli were insoluble in water. 
ITiej" were composed of 

IndigoUc acid . . 27-Od 
Oxide of lend , . 26 
If we consider lliiii lant »att ns a bi-indt^>lale of leiul, and 
take the mean of tlie rvsult», u-ir obutin 'J6-tiB for tie atomic 
I veiglit of iiMligotic acJcL 

But the atLuiytitH of indigotate of potu»Ii, a salt in wliicli no 
I farvijrn buldtancc exeleil, )^ive for llie atomic weight of tliin 
tM-33. For it was compoMid of 

Iiwligotic add . . d5'2ii 
Pota&li ... 6 

I While tlic analysiit of intUgotate of mercury gave a5*5 for tlie 
lie weight of ikiit avid, 

I. UufT anaiyxed tite aciil by means of oxide of cogip^r, and c^nii^aM. 
aetl the following conktituent-i : 

Axotc . . 7*Ji5 

Girbon . . 4d-3l 

Oxygen . . 44-24 


' 'Ihe atomic pr(»)M>rtM>ns wliieli suit tltese nuiulwrs are the fol- 
I lowing: 

1^ utom axote . . 3-625 

22 atoms carbon , . 16-3 

15 atoms oxygen . • 15 


' llii* is IcM than the number derived from llie iu<l!gotate of 
[{Kriimh. If we were to admit tJie presence of 3 atoms of azote 
tin order t«( get rid of lln' tudf utoin. the nlomic weight would 
Inmie out iiof which 1 think Ukt^ly to be Uiu true number. 






Various attempts were miule !>}■ diemUts to ascertain tlie 
aaturc of the calculnux votioretioni* which occasionally fonn in 
tht kidneys and l>lii<iiJi'r, nnd ]irpiliice oiif of the most p«iiiiful 
diseases to wliicli we iirc Ualilc. Tlit-ac alU'injits were attended 
with very little Huccess, till Scliccic publislied a set of experi- 
ments on tlie subject in 1776. He cxumincd ^-vcral of these 
urinary calculi, Jiiid found them composed chieSyof a peculiar 
acid, the proiiertics of which he described. His results were 
80011 aflcr confirmed by Ber^nan, who had engaged tii usimilar 
Bet of c.ipcrimcuts about the some time.* To the acid llius 
discovered, Morveau gave at first the name of bezoanlic, whicli 
was aflern-ards changed into lithtc by the French chemists, when 
Ihey contrived the new chemical nomeiiclattire in 1767, This 
last term, in consequence chiefly of tlie observations and ohjec- 
tioiiB of Dr. Pearson, was nfterwunU laid aside, and the iionM; 
uric acid subatitulL-d in its place. 

Scheole ascertained that uric acid exists ulway« tn human 
urine. Experimental on die urmary cnlculi were j>ubliMbed by 
Mr. Higgins in 1789,t and by Dr. Austin in 1791 ; but little 
was added to our knowledge of uric acid till Dr. Wollaston 
published htH admimblc [luper on the culciilous concretions in 
1 797, Dr. Pearson published a copious set of experiments on 
Uie same subject in 1 798, in which he enumerates his trials on 
uric ucid, und endeavotirit to prove that it U not entitled to the 
same of acid, but ought tu be claimed among animal oxides. 
This drew the attention of Fourcroy und Vanijueliii to the 
subject : tlicy published an excellent treatise on urinary cal- 
culi, in which they demonstrate that it possesses the properties 
of an aci<l, and confirm the observations of Uerginiuiand Scheele. 
But for the most complete account of uric acid we are indebted 
to Dr. Henry, who made it the subject of his thesis published 
in lfl07, and afterwards inscrtt-d a [Ktper on it in tlie second 
volume of tlic new scries of Manchester Memoirs. 

To obtain pure uric acid, Dr. Henry dissolved pulverized 
cnlculi (previously known to be composed chiefly of tliat acid) 
in a ley of potash, and precipitated the uric acid by means of 
muriatic or acetic acitls. 'i'he powder tlitm obtained was 
first waslied witli a little ammonia, to remove any adhering 

• Schevle, i. 1911 and 210. French Thins. 

f ComiwrMivu view of the phlo^«tic and autiphlagUiic iheorica, p. V&. 

time Aao. 



Ibrrif^ neid, arul tl»cn nitUcorated with a suiEcicnt quantity of <^'*" ^ 
wnroD water. *' 

1 criitiuiicd it in coiiMidorable quantity from llio fkeecs of the 
boa cooHtrictor. lliis u^rpcnt voiib its cxcromcnts about once 
n month. Thvy an wliiic and tiolid, and have a certain resem- 
bbuce to the album ^sectiin v»i<)iil by tiog». It u'a» digested 
in caustic [K>ta»li by which abnoHt llie wbulc of it was <IU>i»lved. 
'Pic s^iluiion vas dntwi) ofTcluir from the undii!M(>lvc<l Nixiiineiit, 
and mixed with a MifEdont quuntily of iturt- acetic acid cu.satu- 
m» tJtr whole of the potwsh. A copious white prcci[)ituU> felt, 
whicli iH'ing thoroughly wii»hed with water, and dried in a 
geiitle Imtt, wan fnirc uric acid, 

it was sometimes in tlie state of a white impalpable powder, Fnnntii^ 
MMiiedmesinsnull four-sidod jirisnis, having considerable lustre. 
It u t;L.->te)ess, very white, very light, and insoluble botli iii 
water auil alcohol. In conventmtetl milphuriv acid it speedily 
es tJie form of a jelly, and npoii applying a gentle heat 
piric iKolulioii i* obtuinc<l, without ullcring tlie colour or 
lnu»|Mrcncy of the acid. In nitric acid, even tliough dilute, it 
dmolvci) with cffen-escence, and when the solution is evapor- 
ated to dryness, it assumesi a line ]iink colour, which become* 
mnch deeper when water is .-iddi-il, so as to have a near rexem- 
bboce to cannine. hi thi» «tjitc it stuinii woud, tliv Hkiii, &c. of 
a bcouitfut red colour. I'ho watery solution of this mutter 
loan its red colour in a few hours, and it cutmot afcerwartis he 
natorcd.* Wbcn the solution of uric acid in nitric acid is 
lioUed, n quantity of azotic gns, carbonic acid gas, and of prus- 
■ieBci<l. M di8en(fagcd.t Dr. Pearson, by repeated dt^l illation.'!, 
mnt'crted tite retiiclue into nitrate of ammonia. \V)a-ii chlorine 
gM i> nude to pass into water containing t)ii« acid suspended 
in it, the add w»uiaeA a gelatinous appearance, then dissolves ; 
au-bonie acid g:u w emittetl, nnil the M>lution yiehU by erupor- 
4Mion muriate of mnmonia, binoxulalo of ammonia, muriulic 
aeid, and malic iicid.^ 

It combines wJtli the dUTerent bases, and forms a gcnuH of 

I nils oiled urates, for the examination of which we are chiefly 
indebted to Dr. Henry. 
When digested with water holding carbonate of soda io solu- 
tion, it i;nulu»lty itixHolvcs, while the ciirbonic acid » disengaged. 
'I1ic Mihiiion, how much mcvcr of the acid L» added, stiU con- 

• Srtictlc. Dc/giuun, Ptsrann, nnd Ilenry. 
■f Foarcray; Ann, ilc Chim. wvli. 867. 
t Bn^nxdlit Aim. tie Cliiiu. Kxvii- 307, 

Fourcroy, x. iXi. 


Oup-L tinues to communicate 8 violet colour to cudbear paper. When 
the alkali is saturated, a considerable portion of the orate of 
soda (but not the whole) &11b down in the state of a white 
tasteless powder. 

The crystals of uric acid are composed of 

1 atom uric acid . ■ 9 

2 atoms water . . 2*25 


I found by combining this acid with soda, that its atomic weight 
13 9 : that of t)ie crystals is 1 1-25. Dr. Prout analyzed the 
crystals by means of oxide of copper, and obtiuned for the 
CompoiiUoii. Q atoms carbon . . 4'5 

2 atoms azote . . • 8'5 

3 atoms oxygen . . 3*0 
2 atoms hydrogen . . 0-25 


But we have seen that 2-25 of this weight may be driven off in 

the state of water, without altering the nature of the add. 

Hence the constituents of the anhydrous acid mutt be 

6 atoms carbon . . 4-5 

2 atoms azote . . 9'5 

1 atom oxygen . . 1 

Thus it would appear to cont^n no hydn^en, bat to conust of 
a compound of carbon, azote, and oxygen. The quantity of 
oxygen which it contains is small, compared with its atomic 
weight. It is obvious that when ammonia is formed by the 
action of nitric acid on uric acid, water must be decomposed as 
well as the acid. 


Hi^orj. Scheele obsen-ed that when uric acid is subjected to distilla- 

tion a yellowish white sublimate is obtained, which he considered 
as analogous to succinic acid. Dr. Pearson, who observed it 
afterwards, considered it as approaching more nearly to benzoic 
acid. Dr. Henry first examined it, and showed that it was a 
peculiar acid, united to ammonia. He determined several of 
the properties of this acid, but did not distinguish it by an 
appropriate name. In 1820 it was more particularly studied 

am L 



by MM. Clieralier «nd LaMoigiie, who gave it tbe name of 
pf/ro-mic acid, and who not only delrmiimtl !li diamctcn in 
detail, htit comhiniil it with husos, and asct-rtjunvd the nature 

of ilK Kilt In.* 

\\''kct) uric arid (or cidculi of uric acid> or urate of ammontu) 
k dbtiUod in n retort, hydroc)'anate of ammoniii is diiicii^;&g(?d 
in tht' fimt placr, tbtn a thick einjkyreunialic liquid p&sscs over, 
which ^p^^ily berome.« jtolid ; iifior thin ih« upper part of the 
retort l*M?onies studded witli hratittfiil and tirilliniit while phitos 
which preserve that oohmr if removi'd iinmi-iliiitcly, hut are 
HiUied and at last dU»«Ivcd if the ili«tiUuttuu lie eonlinned. 
Theke crystaU art ])yrurutc of ammonia. The liiiiiid and 
•olid matter in tbe receiver contains also a quantity of the aimc 
■It. Tbtt (udt being (Unsolved in water and mixed with a 
•olalionof diueelaleof h-ail, a white preeipitale fell, Thispre- 
dpitate wms waaJied witli boiling water, then mixed with vtater, 
md a current of sulphuretted hy(l^o^^n fp» passed tliroujrh the 
BUlnrc to prenpitute the lend. The liquid thus freed from 
lad being filterml and concentrated, pyro-uric arid separated in 

Pyr»-uric acid is white, and crystallized in small needles. It ■■nvsrttib 
feels HOinewhal gritty between the teeth. When passed tlirough 
B rv(l-hot glitisi lube, it is decofnpo§«<l into charcoal, oil, carbu- 
retted hydrogen, and curhonate of amnioniH. Cold water di»- 
aolves about tlie 40ih part of its woi;i;lit of tliit acid. The 
■oludon reddcnn litmus paper. Boiling alcohnl of the specific 
fl^vily 0-837 dissolrea it, but when tlie solntion cools the acM 
Uh down ill Htnall while grains. 

C<ineenlrat4-d nitric acid dituolves it, but by evaporation we 
otitain it again uiialtcre«l. It forms soluMc snlt^ willi mcwt of 
tbe bases. Solutions of peroxide of iron, oxide of cupper, 
oxicl* of silver and of mercury, and of dviectate of Irad, arc tiic 
oaly sul»tances whieh occasion precipilatett when dropped into 

B pyro-urate of potash. Tliepyro-urHteof[K'roxideof iron isbuff- 

^ coloured, tliat of copper bluish white. The other preripitates 
■re pt-rfeetly white. 

^ Cbevallii^ and Lasiaigne analyxed the dipyrurate of lead, 

B and feuiui it a compound of 

H I'yro-uric acid 11-16 

■ Oxide of lead Q8 

H Kow 28 n^prcsentA tlic weight of two atonw of oxide of lead. 


" Ann lie Clum. cl ilc I'hy*. xiii. i&O- 


Oup, I. 




and ll'idsliouldbe theatomic veiglitofpyro-uric&dd. They 
subjected the pyro-uric acid itself to an analysis by means of 
oxide of copper, and obtained tlie following for its constituents : 
Oxygen . . . 44-32 

Carbon . . . 28-29 

Azote .... 16-64 
Hydr<^en . . . 10-00 


As the results only are given, without any details, we have no 
means of forming an opinion of the accuracy of these analytical 
experiments. But the number of atoms of each constituent that 
agrees best with these results, and with the atomic weight of 
tlte acid, deduced from the analysis of the pyro-urate of lead, 
is the following : 

5 atoms of oxygen . . 5 
4 atoms of carbon . . 3 
1 atom azote . , 1-75 

9 atoms hydn^en . . 1-125 


The atomic weight thus deduced is 10-B75, while that firom the 
dipyro-urate of lead b 11-16; the difference is very little more 
than an atom of water, which might perhaps remain in the salt 
after it had been made as dry as possible by exposure to heat. 
Were we to admit 10 atoms of hydrogen instead of 9, the 
atomic weight of the acid would be exactly 11. 

The very great quantity of oxygen and hydrc^n contuned 
in this acid, compared wilJt uric acid, is astonishing, and ren- 
ders tt highly worth the attention of chemists to resume the 
analytical investigation of these two acids, in order, if pooBible^ 
to attain still greater accuracy in our results. 


This acid was discovered, and its properties investigated, by 
M. Plisson in 1829.* He obtained it by mixing acetate of 
lead with the juice of the shoots of asparagus ; a white insoluble 
salt fell, which being washed, mixed with water, and decom<- 
posed by a current of sulphuretted hydrogen gas, left aspartic 
acid in solution in tlie water. By evaporating this water the 
aspartic acid was obtained in a solid state. 

• Ann. Ue Chim. et de Phya. xl. 209. 



ntr. IL 

h is n brillioiil wliitv iwwrdiT, which, when vivwed Uiroiif^h 
knuToscope, ajipojire to consist of fuiir-«uln( prisms, U'rmiiuited 
by ililicHlml Hummits, quite transpnn'nt and colourless. It hst» P»r(nta. 
■u Mtiell, liul » slightly atkl la&le, wliich noon paseeH awuy-* 
kavinir tbr impreadoa oi Qsjturaffine. It rtf<{<1ens tlie inru-sion 
of liitnuH. lu specific gravity U I-M3. 

At liio temperature «f 47'i it iliwwlvw in 128 time« its 
woighlaf wstor. Hut it ix inucli mure soluble in Itot wiitir, mid 
weonliagly a hot solution crysliiUizps in co(>liii)>;. It is insu- 
hUe in alcobol of 40 IJeaunii (specific gravity 0-817), nl the 
ordiiinry temperature of tlte ittinotipliere. 

When heated with 1 2 limes its wei)2;lit of nitric acid it \* not 
dcMioyed, at teajti tlie |^>RtV8t |)eut of !t »ti)l remains unaltered. 

Aipartic iicJd when (li-vtolvod in wiiter docs not occasion a 
pecipitatc when dropped into soliitioiu of muriate of liarytes 
m of lime, or into Kulphate of magnesia, of manganese, of ime^ 
<r into Ifae aijts of iron, the aceL-ite of lead, the Aulpliali' of 
nfiper, corrosire 6ultliniut«, nitrate of i^ilvt^r, or into tiirtur 
rtuelic. Hut it deconiposeH tlio cart>onateH, 

i'rum tlie experiments of Plisson, it ai>pi-an to have the pro- 
perty of DonveTting ttnrch into sugar when l>utk<l for a long 
ttiBe with un aqueous solution of tliat principle. Other vege- 
biUe acidN appear to have the §ainc projierty. I)ut I tliiiik it 
ddabtful whether in these cases (he clmnge '» not independent 
of dM Booompanyii^ m-id. At least, I know tluil th<- hot infu- 
doa of barley gradually becomes sweet and suM-eptible of the 
niMMM fcrtnentation, witliont tlie jireaenoe of any acid what- 

All the lupartaleti are dccompoNcd hy heat. 'ITiojm* contain- 
ing; a minrral alkidi give out ammonia and hydrocyanic acidt 
vkil« • oyanotlith' is forni<*(l. 'I'he Boliible aspartates Imve a 
tmttMt of bffef-iea, which U charactemtic. It is obvious from 
ill iJii», tJiat aspartic acid, like the siimptc, contains azote as 
WW of itH coiistitiicnt8. No attempt lias been made to analyze 
Akaad, bat M. Plissun has made a set of e^iporimcnts to 
ieiwuiinc ihe comfioiiilion of «cvtTiil .-kipartateH nith a view of 
ditettBiiiuig ilie atomic weight of lhi« arid. It appears t» be 
iq»ble of uniting with Ihlmts in two proportioni<, forming nen- 
tnil Mpiurtatcs and diaspartatcs. 'i1ie following table exhibit! 
Ar iMolt of M. PUsaon's analyses. 

1. Aspartate tif HWtfneaia, 

tAnparlic acid . , 11 -Oft 

Magiienia . . *2-9 

■ I. M 




2. Diaeparlate of magnetia. 
Aspartic add 

3. Aspartate ofbarylts. 
Atparttc acid 

4. J)ia^>artale (^ lime, 
A«pardc acid 

The numbers after nspiutic acid in cacli of tliese salts, ou^ht 
to represent the atoinii- ^vt-ig'lit i>f tliat acid. But these num- 
bers deviate bin DiiKrIi fnnn fiicli otlirr to enable ua to dmw 
luiy »ati»faclnry conclusions. The analyitiit of wipartate of 
Diaf^iesia diflvre so much from the rest tlint we must reject it 
alloKelhor. Tin* mean of the other thrt-e givi-s u« 16-47. Wo 
may therefori> tuuiumt- l(t'5 as constituting on approximation 
the atomic weight of aspartic acid, though perhaps not a vc 
near on?. 


This acid was discorered in 1820 by M. BracoiinoL 
process which he followed in onlcr to obtiuii it is as follows: 

12 grammes ( I rij^ grains) of strong glue were mixed witJi 
twice their weight of strong sulphuric acid. No action took 
place ill '24 hoiir^. Si.i nibt<r inelieH of WNter were added, and 
the whole WiiN boiled for five hours tJiking uirc to luld water in 
propf>rtion as it evaporated. 'Hie add was now siturateil with 
dialk, and the whole thrown on the filter. The filtered liquid 
being concentrated furnished a syrup, which, left for about a 
month to spontaneous ei'aporalion, yielded granular crystals 
adhering strongly to the bottom of the vessttl. Thw* crytitak 
bad a decidedly sweet tnstc. Being washed witli weak alcohol, 
again dissolved in water and crj-stidlixed a second lUnc, they 
were tolerably pure, 
kptsriiuc. Stigarofffhe thus obtained crystallizes with great facility. 

When the hot solution of it in water ts eoneenlnitiil and I'ttM 
aside a crust forms on the surface, and when this is brokeoH 
another soon succeeds it. When left to spontaneous crystal- 
lization it forms hard erystalliue groins, feeling between tli« 
teetJi like sugar candy, and having the Hhap<' of flat prisms or 
tables. Its taste is as «iweet as tliat of sugar of grapes. It is 
about as soluble in u-ater as tiugar of milk. The solution, 
tliough mixed with yeast, docs not ferment. Alcohol does not 




n*. II, 

difwtiro it even when jimkIci) by heat, aiid tliougti it be woak- 
ciim) by the n<lditton of witer. It U not ito emily niiiltod nor 
•o rasily ili'com posed by htr:it as common Hugar, \\'^licn di*- 
tillfd it yields a white miblimute and an nintuoiiUcal liquid, 
i^Mnring that aiote exista in it aa a constituent. \S'hen lieated 
villi nitric avid it fonoA no raucic acid. Hut imutlier ueid ist 
tmacd to which It»ci>nnot hu given thv numc of nitro- 

When nitric acid ia poured upon sugar of glue no solution 
ake* phictf, but the sugitr bfcomoK pfrfcetly wliitc In conte- 
^aancc of the «diition or dccumpowition of Oxu colouriiif; mnitur. 
When the mixture U heated »obition takes [dncf, but thvrv i» 
no eServcMcnce take« phicc, nor any discngof^enicnt of red 
npour^. Tbe evapomlion being continued (taking cure not 
t« apply too fttrong heat) till the whole is sufficiently concon- 
tnted. it becomes M>lid on cooling, baring the apjiearsnce of a 
oyttalHiH! BUSS. Tlii8 miuM wm ciraiu-tl by prcMure between 
the fold* of blotting paper, mid cryilallixtM anew. In tliis 
flUe it constitutes ititrosacciuiric acid, tbe weight of which 
etCMids considerably the whole weight of tlie sugar of glue 
employ eu. 

It li very soluble in water, anil readily crystallizes in fine '"wpwUw. 
ni, Aal, Mrialeil prixni!), similar in appearance to the 
of ghuiber salt. Its taste Is iH-i<l und nlightly sweet, 
aimiUu' to that of tartaric acid. M'hcn liratcd it SM'clla 
ery much, melts and gives out an acid rupour. It producer 
ehsnge in metallic or earthy solutions. It combines in two 
niotii wiih )>i>i;isili, forming a neutral and a iinitro-sac- 
te, boib iif which crystallixe in line needles. lb utste ia 
itroiu widi an impre^wn of sweetness. When thrown upon 
wniag oottb it detonate^ like nitre. The nitrO'Saccbarate of 
BsiA crystallizes in beautiful needles. It is not delitjucsccnt und 
b Morcely soluble in alcohol. Thrown upon burning coals it 
Bwlla in its water of crystalliitalion, and then detonates like 
I idtrfc 

^K With oxide of copper this acid forms a crystal I izable salt not 
^Haltered by exjioBure to the air; with magnesia an uncryjitallir.* 
^Kalile deliquescent salt; with oxide of lead it fornts an uncrys- 
^VtalfitaUe Nult not altered by exposure, and resembling gum in 
^f appeajmneei. This sidt detonates feebly when heated. Nitro- 
necharic acid dissolves iron and xinc, wntli the disengagement 
o( hydrogen gaa, and forms with tliem salta which do not crys- 


Chaji I. 




Th«se facte (wliicli arc all that have hitluTto b«Cii dcUT- 
miiicd) leave no dotibt tliat niti'»-«accliiiric aci<l i» a combina- 
tion of nitric acid iind sugar of gluo. It is a remarkabla 
circumstance lliat tiaAcsi liavo no disjiuNilion to iteparnte tli« 
citric acid from tlie tiii^nr, hut that tlicy combine witli both atj 
onc-c. Tliix is a sufficient proof that the sugar of glue dues] 
not iitiitc witb nitric acid as a baae, but so as to form n ncwj 
compound acid. 

It would lia^-c been intpre«tlng to have known tbe Btomicl 
weight of this acid, and likewtxc the projiortion in which thai 
nitric acid and siipir of glue unite. But no attempts »eem to 
have been inailc by Braconnot todetetmine the compoeittc 
any of its luiltt).* 


This add, which ha» liitlicrto been but very imperfectly 
examined, waft dlwovered by Kraconnot about the Mune time 
with tlic nitro-xaccha fie acid. It was obuiiiied by tlit- followiiif; 
process : S 

A piece of Diu<>elc of beef as lean as poiwiblc, was weU' 
divided and steeped in water till every thing soluble in that 
liquid wat (ukeii up. It was then subjected to pretty strong 
pres.'siire in » linen elotli. :)0 gnunmea (4<i>t^ grains) of this 
fibrin being mixetl witli their own weight of coiicentrateil mil> 
phiirie acid, softened and dissolved witlinut the add becoming 
coloured or the disen{^){ement of any sulphurous acid. ItU'aa 
heated to render the solution more complete, and alloweil tofl 
coo) that a crust of tallow which had appeared might be scjia- 
iBted. The Holuiion wim then diluted with about »ix cubic 
inches of water, and boile<l for nine hours, renewing tlie water fl 
from time to time as It evaporated. The add was then satii- 
rated with chalk, and the liqin<l being separated by the filter 
and evaporated, yielded }in extract not in die least sweet, but 
having a very marked flavour of roasted meaL When ImiU-d 
repeatedly in alcohol of the specific gravity 0'fl47, tlie alcoholic 
litjiiiils on cooling deposited about 15 grains of a white matter* 
which Itracounot distinguUhe<l by the name oi leucine. 

Leucine when dried is u white powder — but it still retains a 
little animal matter separable by tannin. To free it from this 
matter tlie leucine was dissolved in u'ater, luid ii little tainiin 
cautiously added AfU'r »ome )iour» tlie liquid was filtered 

Ann. dc Chim. cl Jc Vhyt. xiii. II3L 



erapomUd till u [H-Iliclv fonnrd on ito surfiicc. Tliw 
pcliide bein^ rcmovt-d nflf r 24 hours, »iniil) whih- gniiiis wcro . 

ad at the bottom of the vpwiel. Thin was pun? Icucino, 
M'hen leucine dissolved in hot water is left for Bponlaiicou« 
erapontiun tlie leucine formit on tlie tiurlaee lunall round circles 
Hkr tiuttxiiiK, having ;t depri-^itiou in the centro. leucine lias 
■n a^reeabk- laiitc of ItoiU'd tneut or soup. It i» lig;liter than 
water. When hrated it inclt<t at u t«iiipenitur« much higher 
tlifea that of boiling n-ater, i-mittiiig the smfll uf roasted meat, 
and psftly subliining in smnll white upcKjuc cr^'stids. The 
EqitM witich comes over contalna empyTeumatic oil and nni- 

Lcuebin JinKolreA readily in nitric aeid. If we hcut tlic 
wvlutioti to drive off the i-.w-om of nitrit- nc'ul, we olserve Hcarcely 
ajiy cff<TVi-!»ce»i-e iunl no enii.vtion of red viij)Our. 'I'he residue 
«ira[iarated in tJie ttatid>l>alh in ii gentle heat asstinm tlie form 
a 9oli<t crvitULllinc miiwt, which being dried faotweeii fohli* of 
io); |)si|>i-r mid rcditsolvcd in waiter, crystallizes in fine 
direr^nt ncndlex. 'I'Iictm.' mmiles constitute nUrokucic nrid. 

TbU acid foriiM witli (he MtUliublc buses suits quite differ- >nua.i«iick 
nt from the nitro-sacctiaraics, NiQx>leucate of lime is » wilt 
tuil altered by exposure to the air, and which crystallizes iii 
Hiall groups. When Uirown on hiiniin^ coals it melts in its 
water of rrystallizutton, but not so readily us nitru-!incchamte 
lime. Nitroleucale of magnesia crystallizes mid U not 
tercd by ex|M>*iire to tlie air. The remaining properties of 
acid am Htill uiikiiowrt. It i> obviouiily a combination of 
adil with leucine, and tlierefore aiialogouA to nitro- 
ic acid in its nature.* 

! I 



This acid was discovered by Dr. Prout, in tbe yeor IBIS, wmarf. 
I'irlrile vngage<l in examining tlie pink-coloured substaiico 
rfontu^ by heating a solution of uric acid in nitric acid, Ilia 
Itaorf* of obtaining the acid wax at followat 

H« digoMed pure uric aeiil in dilute nitric acid. An effer- 
[tuwnoe look place, and the acid was dts^olvetl. The exceM 
I af nitric acid wiis neutralized by ammonia, anil tbe eva|>oraliftn 

■tiniivd. The cotuur of the liquid became gradually of a 
pur]tle and ilark red granular crysiaL- (Mmietimes of a 
[.ynwniiih Luc exicnudly), ftoon begun to separate in ubundnnre. 

• Ann. lie Chan, ct tie V^ys. \m- I la 




0)« I- These crystals were compoecN] of purpuric ad<l and umtnonia 
they were diaaolveil in a solution of cauMic potaiJit and lirat 
iippliod 1<> tilt- solution till tlii^ rod c-olour entirely disappeared. 
The ulluilitti' isuliition wits tlit-n ^iiduuUy droppf<l into dilute 
sulphuriir add, which uniting with the potash, left the udd 
principle in u state of purity." 

Purpuric acid thus obtained is a cream-coloured powdw, 
which, when examined with a nuignifier, especially tn water, 
appeam to po&ses§ a pearly lustre. It lia& no tunell nor taste. 
Ita spedfic gravity is considerably above that of water, iJiougb 
from il# Riiuuti* »itatt! of divittiou it usually take« a considerable 
timo to Militsidc in thiit fluid. 

It is wry little soluble in water; 10,000 partu of tlial liquid 
not being cupaltle of dissolving one part »f Uie Md«l. In alctJiol 
and (?ther it is quite insoluble. It diswlvi-* reiidily in tlu* c«n- 
centriitfd minentl acid'; and in the slkiitine itobitionit; but it is 
insoluble, or nearly §o, in dilute sulphunc, muriatic, and phos- 
phoric acidt), and ul§o in Holutionti of oxalic, tartaric, ami dtric 
adds. Concentrated nitric acid dl.isolves it readily with effer- 
i-e&cence, and pnrpunite of nminunia i!> obtained. (!hloriue 
likewise dix.solves it, and prodnccH a itimilar cliange on IL It 
dii«Koivc» idso whiMi iu«i.'(led by heal in conwntnitvd acetic «ckL 

It docs not sensibly alter the colour of litmus paper. Wlien 
exposed to the sir it does not <telii]»e«ce. But it beeoom 
gradually red, and some piirpurate of ammonia seem* to Iw 
formed ui it. 

When heated it neither melts nor sublimes, but acquires n 
purple hue from the formation of ammonia, and afterwards 
hurnKf^ntdimlly witlioiit yicldingany remarkable odour. When 
distilled it yields a good deal of carbonate of ammonia, some 
prus^ie ucid, and a little fluid having an oily appearance, while 
a pulvcndcnt charcoal remains. 

It combines with bases, and forms salts to which the name of 
piirptirates has been given. The greater number of these pur- 
puratea have a red colour, though some of them are green and 
Bomeofthem yellow. Purpuric add is capable of decompowiig 
the carbonates when assisted by heat, and it does not, us 6ir is 
known, combine with any other acid. 

Dr. Proiit made some trials to dctcnnine the composition of 
this add by heating it with peroxide of copper. The result of 
his experiments gave the constituents as follows: 


PhU. Trvi*. 1816, p. 4S0. 



3 ntoms hydrogen 

» " ■ 

= 0-25 

2 atoms carfmn 

« ■ 

= 1-50 

1 atom azote 

• • 

= 1-75 

2 atoms ox)'geQ 

• * 

= 2-00 


Dit. II. 

According to tliU analysts the equivalent nun)tM>r for purpuric 
Facid U A'5 or n multiple of it.* 

It may he n^ini^^itv to fttatv Ihut the attempts wliicli I made to 
pnctm this acid by tlio proovss of Dr. i'rottt did not Hucccfd, nor 
SA the phvnomena which I ol<s<-rv<-<I rxiu'tly a^ce with llioi^e 
Aaerilwd by Vauquelin, who cutisiilcrs tlK> colouring matter und 
tlwacidas two different substances. Lnwaiyne conceives lliat 
W has verifie*) thin opinion uf Vauquelin by decompatiing the pur- 
pimte of ammoiitii by moimM of tlic gidvanic lottery. He got a 
Mlonricn add cullcctM) roimd the poMtivc pule, while llio alka- 
Hm tubstmner round the negative pole was deeper coloured thun 
ertr.f 1 suspect that these discordancies are connected with 
(one diversity in tlie properties of the calculi from which tho 

Ie Acid was <^taiDed by the different experimenters. 
JEryrtWc Acid. 
TUs avid was formed by Unignnttflli. His method waa to 
solve uric acid in a slight excmt of nitric nd<l, to evaporate 
Ninrlyt and then put tlic solution by to crystallize in a cool 
pbce. These crj'stals became slowly purple when cJ[po«ed to 
the ur. The purple colour appears more rapidly If they be 
diMolved in water and a few drops of amroonia added. The 
mtnre of these cryMids ba» not yet been witiifaclurily exp)aine<L 
■k would Mem to Ix' ii nit, but wliat the coiintiluentx of thi:t 
^Htt are I do not know. 1 have never luul an i>|)portniiity of 
^■Mtiag Bmgnatclli's paper, which puts it out of my {>owvr to 
•Bttr into farther particulars respecting erylhriv acid. This 

fBM WM given from the Greek word ■fjt'f«i, red, in conse- 
eoM of lih« red colour which it lasumcs when exposed to 



This is the name which M. Lussaigne bus given to the acid tUMar- 
diaeorcntd by Vauquelin and Bunivu in the li<iuur ujiinii of tltc 

• FMwt, Plill. TnuM. 1(118. |>. 4M; 
t Ana. ik Chim. vl dc I'hyi. sxli. 334. 


cup' I- COW.* I^ssaigne examined the tiquor contained in the allan- 
tois, and likewise that contained in the amnios of the cow, three 
several times in succession, and always found the acid in ques- 
tion in the liquor contained in the alUntois, and never in the 
liquor amnli of the cow. He is of opinion that the liquid of the 
allantois had l>een given to Yauquelin and Buniva instead of 
the liquor of the amnios, and on t^at account changed the name 
from amniotic to aUanloic acid.f 
nnrav. Allantoic acid is obtained by evaporatiDg the liquid of the 
allantois. It crystallizes in square prisms, its colour is white, 
and its lustre pearly. It is insipid, and not altered by ezposoie 
to the air. When heated it does not melt but blackens, !• 
decomposed, and yields a great deal of carbonate of ammonia, 
some hydrocyanate of ammonia, and an oil, and it leaves a light 
charcoal, which burns away without leaving any residue. Water 
at the ordinary temperature of the atmosphere dissolves ^ ^gth 
part of its weight, and boiling water ^^th of its weight of this 
acid. The solution reddens litmus paper; on cooling almost all 
the allantoic acid precipitates in fine needles. 

It dissolves in boiling alcohol, but a portion crystallixea m 
the solution cools. The aqueous solution of this acid neither 
precipitates the solutions of lime, barytes, strontian, nor nitrate 
of silver, nitrate of mercury, acetate nor diacetate of lead. 
When treated with boiling nitric acid it is converted into m 
yellow gununy mass, which has an acid taste, but not the least 

All the allantates are soluble in water and crystallizable. 
Allantate of barytes crystallizes in white prisms. Its taste ia 
acid, and it is more soluble than aUentate of potash. Its oos- 
Btituents, as determined by the analysis of Lassaigne, are 
Allantoic acid . . 63-0 

Barytes ... 9-5 

This would make the atomic weight of this add 63. 
The allantate of lead was found composed of 

Allantoic acid . . 58-33 

Oxide of lead . . 14 

This would make the atomic weight of this acid 58'33. The 
mean of these two results gives 60'66 for the atomic weight of 
this acid. 

Lassiugne subjected allantoic acid to analysis by means vS 
oxide of copper, and obtained 

* Add. de Chini. uuciiL ST9. f Ann. de Cfaim. et de Phf a. xviL 295. 



CarixHi . 




Cltm I. 
DC It, 

Hie atomic numbrra agrroiug with this andyms, and approiivli- compwui-w , 

bg nv»ri:»t to tlic utoiiiic wci^^lit deduced from tbe ealta 

KrC4-d, an.* (hr tolluwhig : 
20 alums oxyj^D . . 20 
23 atoDU carbon . . 17-25 
atoms azote . . 15-7^ 
72 otuina tiytlnii^eD . . 9 



of oonsequence the most coinplcx acid which has 
^—.kubcTto bvcn subjected to Bualy^iN. 

^M ascnox li. — yt- iivDKo-vAiino-isiiLi-iittitic acid. 
^V Some alepa tow-urd§ iho fonnaUat] of this acid were made by bmhj. 
BvnxUas in hit \mper on bisulphuret of carbon, but it i« to M. 
Zeise tif Copcnhi^rvn that we are imlebivd for a full iiivestiga- 
^ IJOB of its nature." 

^H When an aqueoua MoiuUoi) of ummoiila an<l hHiilphiirvt of 
^Kari>aii nre left for a conHiderabli.- timi- in contact with f?ach 
^PMbar In a clone vessel, a dark brownish-reil liquid is formed, 
muuBtiii)^ of a ntijitiire of liyrlro-c:irbo<sii]|iliati- of iinnmnii:! iiiul 
nljiho-cyatiaie of amiDOitlii, but contiiiiiin^ no ciirbotiEitc of 
■mnonla. Bimtlplnirct of airboii diswlvm wry rciiilily iti an 
■hnrhotic solution of ammonia. The solution continues aika- 
iinv though a considerable excess of bisulphuret of carbon be 
•tUtd. It becomes itpcolily yellow, then brown, an<l NiniTlU of 
inlpbitrctted hydrogen. In about iialf an hour yellow featbcr- 
rinqied crystab of hydroMsarbo^ulphate of ammoiii:! are formed. 
Tb«e cryvtabiire to be separated and dried by premure between 
hUsof btnttin^ {mpt-r. Beinj; uow tlL<<iw>lved in water, and tlic 
Mlntioii mixed witli dilute muriatic acid, an oily liquid xcpar- 
aS«a, which is bydro-caTbo-Nulphuric acid. 'Hiivacid in separ- 
ated from the watery [mnion by means of a funnel. 

Hydn>-c;irbo-Hulpburic acid obtained by this process is aPrxwnich 
raddiak brown triin^pan^ut miy-looking liquid, heavier tliun 

* 8cliw<igger'a Jiihrbiicb, xi. VO, «id 110. 



t**^^ water, and having a peculiar smell mvtsd with that of nil[Aiur- 
etted hydrogen. M. Zeise is of opinion that this aad ia a 
compound of hydrogen with a combination of sulphur and car- 
bon in different proportions from what constitutes bisulphurrt 
of carbon. To tiiis compound he has given the name of xan- 
thine, and he considers it as a compound of 

3 atoms sulphur . . 6 

I atom carbon . . . 0*75 


Its atomic weight therefore is 6-75, and it is in reality a tei^ 
sulphate of carbon if Zeise's notion respecting its conatitutitMi 
be correct. This xanthine has the property of combining with 
the different bases in the same way as chlorine, bromine, iodine, 
and cyanogen, and to these compounds, several of whic^ have 
been described by Zeiae, he has given the name of xatOkidea, 
OoBimtKB. Hydn>-carbQ-«ulphuric acid, or kydro-xanthic acid, aa it il. 
also called, is a compound, according to Zeise, of 
1 atom xanthine . . . 6-75 

1 atom hydrogen . . . 0-1Q6 

Hence the reason of the name. Or we may consider it as i 
compound of 

I atom bisulphuret of carbon . 4-75 
1 atom sulphuretted hydrc^en . 3-135 

It is obvious that the atomic constitution of the acid, whichever 
view we take, will be the same. The first is conformable to the 
opinions formed by Zeise, but some of the changes which the 
acid undeigoes rather favour the second. Nor are we to con- 
sider the constituents of the acid as perfectly established. For 
Zeise rather drew his deductions from theoretical views tbaa 
from actual experiment The salts which this add forms, and 
several of which have been examined by Zeise, are called 
hydro-carbo-stdpkaiea, or hydro-^canthtUea. 


ukWT. I*- ^^^ been known for many years that when concentrated 

sulphuric and and alcohol are mixed together in a retort, the 
mixture is accompanied by the evolution of much heat, and 
that when it is distilled a very volatile and inflammable liquid 



ii ot>ta>iiRl, dlstinj^uklMMl by tlic name of »titpiiurie elher. 
Foorcroy aud Vuuciui'liii, in ii pA{>«roii viht-rificiitioii, jiublished 
in an cnr)y rulumv of llii' Auimlcs Av Chimu*, ciiilwivouned to 
prove Uuit tlic sulpliuric acid merely acU-d by iibKtntcUiif; a 
yottioti of Uic tiniu-r, uul (but i-tber ts iJcubul deprived of 
■ certuin projiortion of iu w»ler. Tbia opiuiori Wiis called 
b qnndan by M. I)^>il,* n-lio endeavoured to provo tbut 
during tbe pHxrcKM rbi- Htiliihiirieucid iiiukr^oesdecoinpositioii, 
that it yields n portion of ite oxyi;en to tlie uleubol, mid tlmt a 
Mw acid ta formed, intermediate bvtween Hiilphiirous luid sul- 
pkuiic aei<l. Foureroyand Vaiiqueliu objected to this opituon 
(f Dibit, tkat it was aliugelher unMipported by experiment, 
ukI could not tlierefore b« ad<^>t«d by chcnii!it&.i Two years 
■firr, D«bit piibliolicd a M-eond memoir on the formniion of 
M^r,! in ubtcli lie drmonstralcK by verj' decisive experiments 
tktt a acw acid i» formrd during tbe conversion of alcohol into 
(d>er, by th« action of sulphuric acid. It is difficult to explain 
vby no notice whatever was taken of tttU interesting paper of 
Miit, and why no penion thought it worth bin while to repeat 
\n experimenla. 'liie &ct is, tliat ever nince diemLstry existed 
m m •ci«nce, there has always been some individua], whose 
fpiaioiM for tbe ttine were adopted by the chemists on the con- 
doant without dUdiwion or heHitaiioii. FourcroyattJiat time 
njoyed that silnation in France, and the experiments of Dabtt 
vere npglect«-d and fur)|;otten, because they were incoiisitttent 
villi the opinions ot' that eloquent lecturer. Dubit pre[»aTed 
lerenl salti containing bis new add as a constituent, and 
ibmrcd by the roiMt dedsive experiroeiitji lliat ibis new acid was 
tinlber sulphuric nor )>ulphurou», tliough it contained sulphur 
M an emcotJal coiiKtiinent. 

lo ti>« year 1616 I>r. Serturner of Einbeck, published an 
tUwrate poper on the rombinatkm of acid* wHA batti and in 
iifimitt mMoNcrf.} In tliis pHper be ntlirnm ibat »iulphuric 
tad in acdi^ on alcoliol to form etiier, produce!^ no fewer than 
liire« acids, wbidi he dlttingutsbes by the names of acidum 
ffwtatwvtikiimu imi , acidum detOamotAiofiifitm, and aeidum trit- 
awifttkinmnnii 'Ilie firet of these acids is oliUiined, be suye, when 
equnl weights of very strong alcohol and Huljihuric acid are 
ndxed together, llib mixture is to be healed and then mixed 
yjUt a Miffident quaJilily of cludk to latunite ihc acid wLtch it 

Dbr. It 

• Ann. lie CUm. xxxiv. 26D. 
t tbid. xliii. 101. 

f IMiJ. p. 3ia 

i Uiibm't AnDnlen, Ix. 33. 


°^- *■ contains. The liquid being filtered and ev^MHUted yields pro- 
tcenothionate of lime, from which the acid may be obtained by 
means of sulpliuric acid. The second acid is obtained from die 
residue after the distillation of ether, by exactly a similar pro- 
cess ; and the third acid is formed when the second acid b 
exposed to the air. It absorbs oxygen, and is converted into 
tritcenothionic acid. 

Next year M. Vogel of Munich published a paper on tbe 
action of sulphuric add on alcohol, with a demonatration of tlie 
formation of a new acid, to which he gave the name of n^Jn>- 
vinie* This paper of Vogel was commented on at c«Hisidei» 
able length by Serturner, soon after its appearance.f Vogrf 
mixed blether equal parts of alcohol of the ^eci£c gmTtt)^ 
0-617 and concentrated Sulphuric acid, and preserved the mix- 
ture for eight days in a stoppered bottle. He then divided the 
liquid into two equal parts, one of which was saturated with 
carbonate of bary tes, and the other with carbonate of lead. The 
solutions being filtered and evaporated, yielded crystals of sol- 
pho-vinate of barytes and sutpho-vinate of lead. He separated 
the sulpho-vinic atnd frotn both of these salta, ascertunfid ita 
characters, and determined the nature and properties of the 
Siilpho-vinates. He pointed out the analogy between sulpho- 
vinic acid and hyposulphuric acid. But he did not subject aay 
of the sulpho'vi nates to an analysis. 

Soon after the appearance of Veil's paper, an interestiiig 
account of the discovery of sulpho-vinic acid was published by 
Gay-Lussac, accompanied by some experiments of bis own, 
irom which he drew as a conclusion, that sulpho-vinic acid is 
hyposulphuric acid united with a certain quantity of v^e- 
table matter.^ 

In the year 1826, a very interesting set of experiments by 
Mr. Hennell was published on the mutual action of sulphuric 
acid and alcohol, with observations on the composition asd 
properties of the resulting conipound.§ In this paper, Mr. 
Hennell shows the nature oi oil of wine, a liquid which is 
obtained in the process for making sulphuric ether. It it 
obtained by continuing the distillation after all ether ceases to 
come oiF. Mr. Hennell discovered that this oil of wine b a 
compound of 

• Gilbert's Annnlen, Ixiii. 81. f Ibid, Ixiv. 07. 

X Ann. lie Chim. ct de I*hya. xiii. 03. 
g Pbil. Trane. 1826, p. £40. 


2 atoms )iul|iliuftc avid 
4 atoms carbon 
4 atofna hydrogen 




01*. II 

Ral iiway» containing in solution lem or more uf a HuhstAnce 
ompoM^ of iN)ual atomic of c;irl>oii luid liydruf^-n, iiii<i wliivh 
>tfMfate«l sometinuM in cr)>i«ls imd KutiictinK-s in u liquid otiitv. 
Re fotitul farther that oil ut' wiiii- luis tlu- ])ropcrly of eoiiibtn- 
lag with huitK* iind forming neutial tuilttt wilb tlicin ; an<i tliese 
■Ju b4>in^ cxiiinincd weT« found to pouiess exactly th« cliar- 
tcter of Ihff Hulplio-vinaies as described by \'ogeI. Hf fiiuiid 
slan ihnt sulplturic ucid, widch in sumv of Mr. Fanidity's vxpe- 
tfanoiitft hftd absorbed iibout 8U limps its volume of ulofiunl gaa, 
lad by ibid process been partly converted into Hulpbo-vinic 
■BiL Mr, Heniicll hits published a subsequent paper on tim 
■elioo of fulpliuric acid on alcobol, but a* it rcliites niUier to 
ihe theory of etlierilication tlian to »iiIpho<vinic seid, the facta 
which it coNtJiin.t will comu under our review in a subsequent 
fut of this volume when treating of stdphuric ether, 

Salpho-vinic add may be obtuined from sulpho-vinate of 
lad or ralpho-vinate of biirytes. 'I'lie Hulpliu-viiiato of lead 
my be decomposed by a current of ^ulpllurelted hydrogen gas, 
■nd the oulpho-viiuite of barytcs by means of sulphuric acid. 

The BulplKt-vinie acid thus disengaged may be concentrated P»"t"»<i=. 
_hy placing it in an exliausled receiver over a basin containing 
ilphuric scm). By this ])roce!W it may be rendere*] nearly 88 
ly-looking as sulphuric arid, iui<l Jt^ specific gravity may bo 
IM hiph as l'31ft. If we attempt to carry the eonccn- 
fttion fiirtlier the acid uu<Ierg«es decorngMxtition, sulphurous 
id 19 diM>ngaged, and sulphuric acid remains mixed with a 
ttle etberial oiL It undergoes decomposition also if we ntha 
to tlie luiilint; lempeniture. When of the specifie gravity 
|'<tl9 it may ifc left in contact wilb cold nitric aeid wiibuut 
ring decomposed, but when heat JR a|>plied, deutoxide of azote 
. dtBengageil. atiil sulphuric uciil remains. The same altera- 
an i« product-d whvn tlie snlpb<^-Yilnll«H are treated with nitric 

This aeid cannot be- preserved fur any length nf time wlth- 
oat being altered. AAer a bhort time it oceaAions a precipitate 
In nlta of baryles, though at first no such precipitates appear. 
All the sulpbtH vitiates hitlierto oWrve^l are soluble iti water. 
M<»t of ibem crystalUxe and iiavc a sweeti»li tst*U; and their 


'^'^^ solutions are not precipitated by the ealts of harytes or of lead. 
They may be exposed for a long time to the air without uoder- 
going decomposition. But when heated they are destroyed, 
and converted either into sulphates or bbulphates, according to 
the nature of the salt and the quantity of heat applied. 

M. Gsy-Lussac showed that sulpho-vinic acid, when decom- 
posed by means of nitric acid, yields twice as much sulphniic 
add as remains when a sulpho>rinate is exposed to a red heat. 
Hence he concluded that the sulpho-vinic acid was the hyptH 
sulphuric mixed with some vegetable matter. But Mr. 
Hennell has shown by direct experiment that this and is a 
compound of 
compodtka. 2 atoms sulphuric acid . 10 

4 atoms carbon . . 3 

4 atoms hydrogen . . 0*5 


so that an atom of it weighs 13*5. It saturates just as mudi 
of the bases as half the sulphuric acid which it contains would 
do. On that account, Mr. Hennell conceives that one-half of 
the add in it is saturated with the csrbo-hydrc^n, and that 
only the other half is at liberty to combine with bases. Bat 
this view of the subject is scarcely compatible with the fiiet that 
sw>€et oil of wine'ia perfectly neutral, unless it be rendered so by 
the excess of carbo-hydr<^en which it contains. The carlx^ 
hydn^en contained in sulpho-vinic acid b a compound irf 4 
atoms carbon and 4 atoms hydrogen. It b therefore analt^ous 
to the tetarto-carbo-hydrogen described in the first volume of 
this work (p. 200), though, as it may be obtained even in a 
solid state, it is certainly not identical with iL It would appear 
from this, that carbon and hydrogen are not only capable of 
forming a variety of compounds by grouping tt^ther a greater 
or smaller number of particles of carbo^hydrogen, as has been 
explained in a former part of this work (Vol. I. p. 191), but 
even when the number of atoms is the same, the nature of 
the compound may be altered by a different mode of arranging 
the atoms. We may then consider sulpho-vinic add as a com- 
pound of 

3 atoms sulphuric add ... 10 
1 atom tetarto-carbo-hydrogen . . 3*6 


It is clear that both the atoms of sulphuric acid are in combina- 


ftiow with the atom of tcULTlo-<;ftrbo-byiirog;(^n, otlierwwe llie ?J" '• 

I WrytM Raits voiiUt un<toiil)tc<11j- net upon it oiid throw- down '. 

ikat portion wluvh is not in oombiiuition. 


This BciA WW also discovered by M. Zeise. His method ^-urr. 
s (bllows : To a sotulioo of pota&h in alcohol bisulphurct 
of carbon wu gradually addc-d till (he alkali was neiitraiized. 
By this |>To<»«i xanthiv acid wa.t fonncd, wliicli butii^ cocnbiiied 
with tlio aUuili constituted xaiUhate tifjtotaxh. 'Diis nudl cry»- 
yittM in nc«dlM ; it is colourle^ and posMased of coruidvnibic 
brSltMicy. \\'lien exposed to (he air it heconea slightly yellow. 
lu tute is cooling, sulphurcoiL-s and lOiaq). It is very soluble 
In water, and yet does not ab«oT)> moisture from (he atmospliere. 
Il ^Molves al<M) ill alcobof, luid iit very Mliglitly M>luMe in edicr. 

When mtiriutic icid or sulphuric acid, ill a concentrii ted state, 
Li poured u[Kin (his salt do efler\-esccnc« takes place, but if these 
arids be diluted with four or five liint-A tlit-ir weight of water, ii 
!i(|uid Kepara(e« heavier tlwm «iiter, and having lui exact resem- 
blu)c« to nn oil. This liquid is xatUhtc acid. 

This add is transparent and colourless. It is liquid at the i'">t>cii>i 
otdiaary temperature of the atmosphere, and even when tooled 
madt lower. Il b heavier (han water, and dues not unite with 
that liquid. When expUMtl to the sai it is soon covered with 
awbitoopnquecruAt. It undergoes spontaneous deeomposicion 
whni kept undiT water. Its smell is Hlri>ng and (leculiuf , bear- 
ing MHnc analogy to that of sulphurous acid. Its taitte \» acid ; 
k th«n gives an astringent and bitter impriMwion. It rechh-ns 
paper stained bine with litmus, and the reddened part soon 
bcc»mm yellowUli-wliite. 

Tilts acid diKHolves readily in an aqueous solution of potash, 
hurytcs, or imimuniii. It diNcngage^ carbonic acid from carbo- 
nate of puta.'^li, and forms xjmtluile <if pu(a&b. The other ulkuliiie 
xanthoUii may aUo bo made by <tige!iting it on the respective 

In tJ)e open air (his add catchi^tt fire from the Aame of a 
ctndle, and hums with a strong oilour of bulphurous acid. 
Wbeit heated in n retort it unde^oes decomposition at a t<.>m- 
penlure mueh lower ihau tliat of boiling Mater. Common 
bisulphuret of carbon ts formed and an inSammable gas evolved, 
which has neither llie xmell of onioiw nor of sulphnrmis ucid. 
It readily diMoIves iodine. The Hwlution is at first yellow and 
(hen becumn brown. But the colour won disap])can«, and in 




chm I. two or three minutes (provided too much iodine has not beeii- 
added) it assumes the form of an oily opaque liquid, having a 
light yellow colour. The aqueous liquid above thb oily matter 
coDtaius a solution of hydriodic acid.* 

Xanthic acid is characterized by precipitating the salts of 
copper yellow. 
comps^tiaD. According to Zeise this acid is a compound of 
4 atoms carbon , . 3 

4 atoms sulphur . - . 8 

3 atoms hydrc^en . . 0-375 

1 atom oxygen . . 1 


This would make the atomic weight 12*375. But this opinion 
is not founded upon any analysis of the xanthates, but upon the 
supposition that the acid is a compound of two atoms bisulphuret 
of carbon, and one atom of alcohol. For alcohol, as we shall find 
afterwards, is a compound of 1 atom oxygen, 2 atoms carbon,- 
and 3 atoms hydrogen, so that its atomic weight is 2*875 ; while 
that of bisulphuret of carbon is 4*75. Thus we have 
3 atoms bbulphuret of carbon . . 9*5 

1 atom alcohol 2-875 


Bat this opinion, not being supported by satisfactory analyses) 
cannot be viewe<l in any other light than an ingenious conjec- 
ture. At least in none of Zeise's papers on the subject, whidi 
I have had an opportunity of seeing, is the statement supported 
by experimental evidence.f 
xuthici^ During the distillation of xanthate of potash, a substaDoe 
comes over whidi Zeise has distinguished by the name of x(m- 
thic oil. It is limpid, has a yellow colour, and a very strong 
and peculiar smelj which adheres long to every substance impre§^ 
nated with it Its taste is sweet and sharp. Water dissolvee 

■ Zciee; Ann. de Chim. et de Phys. ■x\\. I60> 

t The reader will find the composition of this acid stated on Zdte'a an- 
thoritj in L. Gmelin's Handbuch dcr Theoretischen Chemie, i. 328 ; bat 
Dot aupported by experimental proor, as Omelin is always in the habit of 
giving when any exists. 1 am induced from this to suspect that the atue- 
ment is founded on experiment, though I know of none. As I have not 
had an opportunity of seeing all the periodical works on chemistry in Oer- 
many, some of Zeise's papers might have been overlooked by me. But tbii 
is not likely to be the case with a professor of chemistry in a German uoi- 




U in rery uiudl quAntity. But it in abutiditnlly dissolved in 
even very wrnk nlcolioL It bos no add qualities, does not 
inopitate metallicsolutions hums willt a blue fliune, aiiil tliu 
•volutioti tif much Hiil|itiiirutis acid mixitl wiili (.-urbuitic acid. 

\\*li«-u the xsnttiatt-fl arv distilled Ihcy ore dct^vuiposcd, Hid- 

jiliunrtU'd b>dru^'ii.carl>onicacid.nndxanlliicoi) lieing fortnvd, 

lad there ivinidns in the retort » ttul|tliiirel mixed with cluircaui, 

S'itrie itcid wtd clilurine <li'<;orn)>iM<^' iht-sc sall-i by destroying 

I lite lantiiic add; while diluted muriatic and sulphuric acid 

iinuaipo»e lb«in, fX|H'lling the isntbic add. The aikaUri« 

i iuUHiie»nre»rdubU- in water, and ilieygivc- wiihsaluof Ivadft 

I wUto, and witli salts of co|i|>er ;i ycUow, )ireci|iilati:. With sails 

' oTprutoxideof mercury and oxide of »ilrer tbeypvc brown and 

I blwk prcci]ii(ateS) or at Iruat tboy speedily iissume these c<olour9. 


^P* TUa acid wns discovered by Mr. Faraday in the year 182(i, iimw;. 
^ImI deM-riiied by him in a piip^T inserted in the Philoeophicul 
TiamtctiuQ* for tlutt y<>ar. When concentrated sulphuric acid 
it Ittft iu contact witli pure naphlhaline, a combination gradu- 
ally takes place, and if the proportion of uaphtlialiue employed 
^ bd DM loo great, a complete sobilioii is obtained when tbe liquid 
I bdihibKl with n'aler. WWii carbonate of haryles is digested 
with thi* liquid the uncombini-d sulphuric aci<l ih converted into 
(Ulpfaatif of barytce, while u ncutnd solution of sulpho-oaphtlta- 
bu> of barytes ia obtained. Ily 6ttcriug the liquid and evapo- 
tving. tbe sulpho-naphtlialate of barytes may be obt<tine<I iti 
inperfcet er)'«tii]!i. Ily <li«»(dviii^ (lat Kalt b wut«r, and exneliy 
■uniting tbe tttrj-ttw iu it wilb Milphuricacid,and tben filtering, 
th« »ul]>h(Hnnpbt)ialioadd is obtained pure in a stale of solution. 
TU» dquid strongly reddens lilmus [laper, and has a bitter pk(wiu 

acid tas(«. \\'hcn ntrongly concentrated by heat it asaumen 
brown colour, aud <ni cooling becomes thick and ultimately 
and i> very tUdiipiescent 'Ilio heat being renewal it 
miilted, be|j;a» to smoke and was charred, but did nut flame, 
lidy gave sulphuric and sulphurous acid vapoura, and 
Anotim portJoo of the uune aqueous soluliDn of sulpha- 
ialte acid wait pbici-<l over nulphiiric add in an exhausted 
In »on)c hours it liecnme by concentration a soft 
htte Milid, Bpjiarently dry, and after a longer period it was 
luud and britlte. In tliis state it was deliquescent in the air: 
but iu rloM- ri'Wek it inideroent no diailge in scvend inontlw. 

111. N 


'^^ ^ Its taste was bitter and acid, accompaDied by an imprendon of 
something metallic like that of salts of copper. When heated 
in a glass tube it melted before it was heated-to 212°, and fm 
cooling crystallized from central points ; but the whole nlti- 
mately became solid. When more highly heated water was 
first given off, and the acid assumed a slight red tint, but no 
sulphurous acid was yet driven off, or charring produced, and 
when tested by mmiate of barytes it gave but very slight trace* 
of sulphuric acid. In this state it seems to have been anhydroob 
A higher tempemture caused a little naphthaline to rise, the red 
liquid became deep brown, and then asudden action commenced 
at the bottom of the tube, which spread over the whole, and the 
acid became black and opaque. When the heat was continiied 
naphthaline, sulphurous acid, and charcoal, were evolred ; bvt 
a portion of sulpho-naphthalic acid remained nndecon^KMed 
miless the temperature was r^sed to redness. 

Sulpho-naphthalic acid combines with and neutralizes tlie dif- 
ferent bases, and all the salts of it hitherto formed are solnble 
in water. When strongly heated they bum with a dense vhite 
flame, leaving a sulphate or bisulphate according to the natane 
of the base. 
ctavaHioD. To determine the nature of this acid Mr. Faraday sabjected 
Bulpho-naphthalate of bary tes to analysis, and obtained from 100 
parts of the salt 

Barytes . . . 27*67 

Sulphuric acid ■ . . 30-17 

Carbon . . .' 41-90 

Hydrogen . . . 2-877 

So that there was an excess of 2*517 per cent The reeson 
was, that the analysis being made upon only a few giainB, aay 
error committed was multiplied many times when it was reduced 
to 100 grains. But if we consider the salt aa a compound of 
Barytes .... 27-57 or 9-6 

Sulpho-naphthalic acid . . 72-43 or 24-54 
it is obvious that the atomic weight of the acid must be 24*5. ' 
Mr. Faraday considers the constituents of the arid to be 
2 atoms sulphuric acid , . 10 
20 atoms carbon . . , 15 

8 atoms hydrf^n ... 1 


Bit & ii dear liuu 

8 alMitt Hnlphuric ndtl 
18 lUonn carlioti 
d fttons liydrngea 


an thf> projiortions which eorreapontl with the at»Riic wPtj^ht of 
t^ acid sn disluccd fram tlto ntulysu uf 8ulpli<>>tuip)ithalate of 
btiytea. The exact results of the siiAlysis are 
2-13 atoms sulphuric acid, 
19-75 Htiiirn^ mrlwii, 
t:^l<) atoms hy(lfx>gen. 
Wrrcwv to consider ftulplvo>naplitluilic acid asacompound o( 'i 
Monu •ulphiiric acid uiid 1 nUnn of naphthaline, and were we 
toadmit nwfihtliaUnc to he a compound of 

ISatooM cvboii . . 13'A 

atoms hydro^a . . 1*125 

aoeords with some of tiiv anulyscH of it tliut have been 
the atomic weight of siilpho-tuiplilhalic ac-id would he 
I am inclined to the opinion that tliis is its true con- 
iiition. Uri'M'iuhli.-^Hulpho-vinicatud iacontatDiuglwoutoins 
Hulphurlc acid, m Ihut tlie naiunitin); power of tlus acid is 
to one half when it cunib!nt---< with tuiphibiitine. A 
doUuhnl examination of tliisacid will pruhably throw new 
if^t u|K)n tlie eoustilutioii aud alomio weif^ht of naphthaline. 
On this account it Mceins entitled to more attention than luts 
been hitherto pniJ to it ; fur 1 inn nut aware tluil Mr. Fara- 
fay'a expenB>eDts have been repented. 1 iinleed prepared one 
IT two of the Giills which he described, merely to jiulge of their 
tpptrwance ; but did not subject ihem to any additional exum- 


^^^^■it acid, which is obviously itiiulo^^uH to iIk- two pivcedin^, iiiturr- 
^mOiioovered by Bracunnot in I61'J, during his research es on 
the aedoa of coiioeutrated sulphuric aci4l on v^;etat>lc sub- 

WlWD pieces of Itueii or hemp dutlt are left in contact willi 
Bmeaotnited Hulphuric acid tliey speedily loso their texture and 

■ Aan.ileChini.cltiePliyt.xit. 172, 


cfetp- 1- are converted into a pulp. When thb pulp is diluted with 
'~~~ water the greater portion of the linen disaolres, U^ther wiA 
the sulphuric actd, leaving a quantity of black matter which ia 
to be separated. The solution is now to be saturated with car- 
bonate of lead in order to get rid of the sulphuric acid ; and 
the sulphate of lead being separated a current of sulphuretted 
hydn^n gas is passed through the liquid to t3irow down the 
lead which was in solution. The liquid thus freed from lead 
being concentrated cauUously, leaves a transparent substmice 
resembling very closely gum arable in its properties. 

If this gum be mixed with very dilute sulphuric acid, and 
boiled for some time, it is converted into two very remarkable 
substances. By far the greatest part of it assumes the form of 
a crystal lizablc sugar ; but another portion in which the sul- 
phuric acid that constituted a portion of the gum is wholly 
concentrated, possesses the characters of an acid, and constitutes 
the substance to which Braeonnot lias given the name of vegebt- 
sulphuric. This acid may bo separated from the sugar by diges- 
tion in rectified spirits, which dissolve the acid t^^ther with 
a small portion of the sugar. Being evaporated to tiie connst- 
ence of a syrup, it was agitated in a close vessel with ether, 
which assumed a straw colour, and being evaporated left regeto- 
sulphuric acid in a state of purity. 
iTopntin. This acid is nearly colourless, its taste is very acid, almoM 
caustic, setting the teeth on edge, It is deliquescent and 
incapable of being crystallized. When exposed to a tempers 
ture a little elevated it gradually assumes a brown ctdonr. 
When exposed to the heat of a water-bath it is decomposed, 
and becomes black at a temperature rather lower than that of 
boiling water. When in that state, if we dilute it with wat«^ 
flocks of vegetable matter, partly charred, are deposited. And 
when muriate of barytes is dropt into Che liquid, a precipitate 
of sulphate of barytes &Ils. It is decomposed still more rapidy 
at a temperature above that of boiling water, and sufiboiting 
vapours of sulphurous acid are exhaled. 

This acid occasions no precipitate when dropt into metallic 
solutions ; it does not even throw down any thing when mixed 
with nitrate of barytes or diacetate of lead. It efitrveson 
strongly with the carbonates, and dissolves metallic oxides, 
forming salts which arc in crystal lizable, deliquescent, and inscH 
luble in rectified spirits. I'hcse vegeto-sulphates when heated 
are decomposed, sulphurous acid being evolved, and a sulphate 
mixed with charcoal remaining. It dissolves iron and zinc with 


I cvglutioii of by<lfo^ii ga*. 'ITie vegeto-siilpliaie* of 
rytcs aiid leatl are very m>Iu)»I« in wat«r, and have the appear- . 
lee of |i;uin. 
Nu oUempi Iiw bcren idimIc to iiiiulyxi' aiiy of Uie regeto- 
ImIok, or lo dvUrmiiiu tlic coiiitlitm'iifat of v«gcU>-«tilphuric 
'^■cicL It ubviouftjy co»tuin8>iulphuricaci<lusuc'(iiUiUtuciil, iuh] 
ib iituilutc)- with the two jirccediii); acids is so close- tluit llicrc 
MN be littlo doiibl of il» Ix^iujt a coin[rou»il of 2 atoms siilphu- 
ricactdaiid I iitomofMi^ar uf liitcn. Furlbor rcnearcbes oii it 
voubl bv iiitcruHttnv;. becuuM.- tbcy would be likely to tliruw 
ligbl oil tltL* utuitiiv WL-t^Iit of Itncii Hii^r; frum wliich notav 
MOcJusioits might be druwii rcHf>cctiug tbc Htomiv w«.'igbte of tliv 
ififlWcat species itf suj^, respecting wbtch we atpreuiu know 


Dlr. II. 


'I'his acid ww dlacorcred by MM. Henry, junior, und iiMmr. 

in the expressird oil of tlii^ timijiiit uU»i ; und iiH iboy 

lliut »ulpliur wns one of tltc conjttjtuents of it, they gnvo 

tho luune of fKule sulphotinapigue. It apprars to cxiKt in 

rioiM cniciform plantjt. 'Die iiii'lhoil of obtaining tliis acid 

follows : 

Digest die exprevmnl oil of sinapis allia for a couple of weekii 

fa) I i itA wi'Iglit of ulcolio) of tliv specific gnivity iit Ictut of 

O'^fi? (but the stronger tlie better), sbalting it fre4]»ently 

daring the digestion. 'l*hfn dmw off tlio alcohol, mix it with 

a Uttli* watvr, und ptiuing it into a retort dlMil olf the biilf of 

ihcaleohol. When the matter in the retort is .-illowcd to ciud 

a prveipilato of fntty matu-r lalls which bnd bei-n lield in solii- 

tioa by tlie ulcultol. Free llm liquid from lliis fatty matter, 

and leave it to oponianeouit evaporation. Ilm sinapic acid falls 

^^inpure in ibe form of a granubr leddiob mutu. It contiinn a 

^■EMy matter which is temored by mcnns of etlier, witli wbivb 

^HU>e impure acid iti re|ieatedly macerated in a close vessel. I'lic 

^Kfint (Mirlions of tlie etlier ucipiire a carmine red colour, from 

^Kbtty malti>r dtssoh-od. As toon m ether ccbscr to act u|>on 

^■ihe acid il ia di«wlved in n little water, ttie solution is Bllered 

and Ivtt to KpontniH'ous ovaponition, or it mny bo left in tlie 

lum of ilip uir-punip over sillphnrie acid. I1te itcid fJioota 

I KnwU, glitUtring, lialf Hp]ieri«nl groups of cryktub, or into 

Sina{<ic ucid tliuo obiuined lias a light yellowish colour. Itit mpniiM 
is billcr, sharp, luul sulphureous. Il does not n-ddcn 




cbtp. L litmua dncture, but blackens it like a solution of a hypo-sn^hate; 
" But it reddens the ttncture made from the petals d the malUnr. 

Whether these crystals conbun water has not been ascertaiiied. 
Tbey are soluble in water and alcohol, and sligbtly solnble in 
ether. The aqueous solution may be evaporated to drynea, 
and the acid exposed to a heat of 230° without decompositioa. 
When the dry acid is distilled in a retort it is decomposed A 
little of the acid indeed sublimes unaltered, but by fiir the 
greatest part is resolved into carbonic acid, so^huretted hydro- 
gen, and ammonia, and a coal which remains in tbe retort. 
Even when the aqueous solution is long boiled the acid is 
partly decomposed, and sulphuretted hydrogen exhaleflj whidi 
blackens paper dipped in acetate of lead. 

The composition of this acid is very remarkable, once it 
contains no fewer than 5 constituents, namely, oxygen, hydro- 
gen, carbon, azote, and sulphur. The proportions of these 
constituents as determined by Henry and Oarot are as follows : 
Oxygen . . . 11-91 




Carbon . 




Sulphur . 


None of the salts which this acid forms having been subjected 
to analysis, we do not know its atomic weight But the smallest 
number of atoms which correspond with the preceding analy- 
sis is 

1^ atom oxygen . , 1-5 

9 atoms hydn^^ . 1-125 

9 atoms carbon , . 6*75 

1 atom azote . . 1*75 

1 atom sulphur . . 2-00 

13-125 ■ 
Hence the atomic weight is either 13-125, or a multiple of 
that number. 

The alkaline and earthy sitiapatea have a bitt«r taste. Sina- 
pate of potash and of soda shoot out into small crystals about 
the size of a millet seed. Sinapate of ammonia forms small 
translucent crystals, which appear to be octahedrons. Sinapate 
of barytes forms small ueedies which effloresce in the air and 
are very soluble in water. Sinapate of strontian is umilar, but 



not ctysUUIze so readily. Siimputc of lime dtitsolves very 

mKlily, KJid wlwa ciniporatcd furnw mitmillary concrctioiu. 

Ktunpic ncid jirives a purple red colour to tlic saltit of the per- 

I oxide of iron, aiwl by this acUon a very minute quantity of iron 

^K^y be dvleet^^l. liy tlii.i roactioii Henry and Ciarot di»- 

^nDveml the preoence of lin^ipie acid in pepper cotnn and in tiie 

H|M(h of re<l caUMgc, lurnipt, iind radiitlies, an<t in water «!!»• 

tiUod bota pepper. But they found no traces of it in die leaves 

of erenea and cochlearia. 

This acid DOcaaioDS a precipitate in diacetate of lead, nitrate 
of raereury, and nitrate of silver ; the two latter in eurdy con- 
oetioiu, wliieli are separated by boiling, and become blaek. 
The sionpotc of silver iHunt soluble in mtricacid. Sinapicacid 
^ves a ^cen colour <o n solution of sulplinte of copper, and a 
I white precipitate gnuluully folU.* 

^r Sdcb are the properties of the eompound oxygen acKlti, so for 
H H tlio present state of our kitowtedge eniililrt um to go. It is 
not unlikely lliat BOme of them will hereafter require to liave 
hnr pOMtion altered. For it is more than prul»d>le tliat meU 
acid and croconic acid coutaintt notliing but oxygen and 
and tkat therefore tbey sliould be placed along widi 
onlic acid in the first division of thw class. The atomic com- 
I pCMt ion of these lliree acids is probably us follows : 

^^^^^k CutuD. Oir*n>. 

^^^H Oxalic 2 atoms + 3 atoms 

^^H MeUitic . fi . + 5 

^^^^ Croconic 5 . .^ 4 

^FBnt u tlie absence of liydrogen iit tlie two lust of these adit 
has Dot been demunntratcd by sufficiently accurate experiment^ 
I tliuik it belter for llio present to let them retain their place 

I imoaf^ the compoun<l oxygen acids. 

H If the analysis of hydro-eurbo-sulphuric acid be accurate, it 

^|eoittui» no oxygen. Zeise biet t-tuleavoured to show that 

^L^m «xkti ■ principle to which hS has given the luune of 
« g<* fiie, composed of 

a atoms sulphur . . 

I atom curbou . . 0*78 




* Not lianm Hemy anil Onrot'i paper ai haad, I Iihyc eitracteil thi* 
ni Jrom Berwliut' Uirbol i Keiiii<--n, 4 dcttn, p. 103, whirh h a pnfttj 
I ahrii^piieiit of the p3|>cF iu ijueatiou, to far lu my recoUoclioii gfKf. 



°<*p-^ vhich is capable like cyanc^n of comlnDiiig wiUi Uie different 
acidiiiable bases, and converting them into acids. Hydro-cai- 
bo-sulphuric acid he considers as a compound of 1 atom of xan- 
thine and 1 atom of hydri^n. Should tius <^inion be con> 
firmed by future experiment, we must add another class <if 
acids under the name of xanthine acids. But as Mr. Zeise's 
experiments are obviously insufficient to establish hia opinions 
upon a sufficiently firm base, I thought it better in the mean time 
to place this acid along with the oxygen acids with a compound 
base, to which it obviously bears a striking an^i^y. 

We have no idea at present in what way the numerons 
atoms composing these compound acids are arranged. Hence 
a knowledge of their mere atomic constituents is of little 
vnportance, excepting so fiir as it gives us the atomic weiglit 
of each acid, and enables us to form some judgment respeclii^ 
the comparative simpUcity or complex nature of each. The 
following table exhibits the constitution of the first subdivision 
of these acids so far as it has been determined : 
















Atoms of 










. 2 



. 4 

. 2 



. 6 


. 32 
. 15 

. 16 



2 . 
1? . 

. 11 

. 2 


0? . 

. 4 


. 4 


. 6 


. 6 


. 9 







We see from this table that the smallest number of atoms in 
any of these acids is in the ybrmic which contains only 6 atoms, 
while the most complex is the idmic, which contains no fewer 
than 64 atoms. In the gaiUc and ulmic acids the atoms of oxygen 
and hydrogen are just in the proportion to constitute water. 
In the formic, acetic, succinic, citric, croconic, mellitie, tartaric, 
vinic, and mucic, the hydrogen is in too small a ratio to satu- 
rate the oxygen. Formic acid might he resolved into an atom 
sf water and an atom of ulefiant gas, and citric into two attHOs 


of water aud two atoms of dtcurbonic oxide, In benzoic, cam- '^>*^ '■ ■ 
[tliflric, ftiihcric, und kiiiic, it b iii loo gn-ut u ]>roponio[i. °''' "* 

Tlx' fotlciwing table exbibits tbv constitution of Hudi of the 

rliitty wide as liaVe been aiiiil)']e(<d. 
^ 1. Soiid acids. 



















2. Liquid aeid», 

AMU (4 








hj ilwnt > 

















TIio striking difference between tliese n«ids and tlie Inat set 
consista in tlie (^rr^t number of iitoms of cArboti Hn<l bydrogeii, 
mnpwrcd to the snrnll number of atoms of oxygen. In ito oKt 
io vrp find th« number of atoms of carbon and iiytbvgrn equal. 
Bat in general the a))|irisK'h to eqimlily iit »o evident that I am 
dnpoccd to considiT these aeidH as compound.'* of oxygen with 
MKd or Kqittd multiples of earbo-hydrogen, conbiiiiing many 
more atoms of carbon and hydrogen than any yet met w!lh by 
eheiuLtiH. The iilomie weights of the soliil acids arc in gencnil 
kighcr than those of tlie liijiiid. Are we to infer from thi» 
ibMt the tendcney to solidity increnseii witli the number of 
Btoms of cnrl>o-bydrogeM that unite into one complex atom ? 
i Tlic follovring table exbibits the constitution of the ucids 
eonposcd of oxygen, carbon, and azote : 


Carbaootie . 16 

Indigodc . . 15 . 22 
Uric . . 1.6 

In these the atoms of azote are always few, scarcely exceed- 
ing S, whili^ tlitMe of oxygi'U itud carbon are anmerouN, with 
Uw exeeptiun of uric ari*!, which w inueli Hiiupler in its cooi- 
ition than the other two. 

Tbe fnllowiiig talde tliow* the constitutioii of thou acidfl 2™3ta!' 
are coinptHtcd of oxygen, curbon, hytlrogcn, and azote. 













^^P '■ Ataamt AUoioT Atooaof AtHBmal 

Purpuric . . 7 
Pyniric . . 5 . 4 . 9 . 1 . 19 
Allantoic . . 20 . 23 . 72 . 9 . 124 
The following table shows the atomic coustitulion of those 

acids that are composed of oxygen, carbon, hydn^n, and 

sulphur : 

Alaoaof AlaoMal Atoattf Atttmci —-. 
ranco. cubon. liTdn«n. Milphur. ""*■ 

Hydro-carbo-flulphuric ? 

. 1 

. 1 

. 3 

. 5? 

Xanthic . . 1 

. 4 , 

, 3 . 

. 4 

. 12 

Sulpho-vinic . 6 

. 4 , 

. 4 . 

. 2 

. 16 

Sulpho-naphthalic . 6 

. 18 . 

. 8 . 

. 2 

. 34 

The sulpho-vinic is a compound of two atoms sulphuric aod 
and two atoms olefiaut gas. It is cot unlikely that sulpho- 
naphthalic acid is a compound of two atoms stilphnric acid with 
one atom of naphthaline. The probability is that the consti- 
tution of the other two acids, included in this table, is not 
accurately made out. 

It is very doubtful whether these compounds owe their acid 
qualities to the oxygen which they contain. Certainly the 
degree of acidity is not proportional to the proportion of diii 
principle which they contain. There can be no doubt that 
each acid as a whole possesses electro-negative qualities; but 
these cannot be ascribed to the oxygen, which in the £atty adds 
must be completely overpowered by the great number of electro- 
positive atoms with which it is combined. 


I have no doubt that the acids formed by the combinatioiu 
of chlorine with the acidifiable bases are numerous, and they 
will probably one day rival the oxygen acids themselves. But 
they have scarcely yet attracted the attention of chemists. The 
consequence is, that the fects respecting these acids hitherto 
ascertained, if we except muriatic acid, which had been known 
and investigated loug before its constitution was suspected, are 
very few. I shall lay them before the readers of thb work ta 
the two following sections. 




sscnoK I. 





lliiTi* H li(tlc doubt tliat Uiis acid vnia known iii tlii' ^'vcnlli auutj. 
t«n(iiry, as il b <li*tjiiclly alluikil to in the writings of Gi-bcr. 
BdI Glauber seonu) u> luivc been tlic divmist wliu contrived tlie 
Ipretcnt mode of obtaininf^ it^ by distilling a mi^tnrf of »ul- 
linric acid oik) common mlt. ItwasdistttiguisbL-dby tbv iifimt's 
of ^irit qf »aU, marine acid, and muriatic* acid, doubtless 
brouisc It is obtained from comMon stdt. Mr. Csvendiiih first 
abtkined this add in tlie ^i-wotu stato, and mentioned tii« cir- 
tmNbUioe in hi« pprr on Factitious Airs, publislKsl in n7G;f 
hit be docs not svcm to have been awaro of the nature of t)ie 
tlostic flnid whicli lie obtained. The subject was ufterwurds 
taken up by Dr. Priestley, whoascerrfiiiied tbe nature ami pro- 
iea of muriatic acid gm, niid must tln^rcfore be conaitlcred 

tbe true discoverer of it^ In 1774 Scbvel« discovered 
irine gas, and staled tbo <:iim|K«»ition of muitatic acid to be 
itie uiiil4.-tl to pfdiM/itlvM, By jihlogUton he tueaiit hytlroiiVH, 
Therefore, acconllng to tlie opinion of Sclieele, muriatic avid in 
% oompound of chlorine and hydrogen. Tlib opinion was 
■ef^Ic^ed for many years; but uiw rrvix-ed a^uin in 1810 by 
lir H. Davy, in eonsequenoe chiefly of tlic experiments of 
«y-Luiwac and 'llienurd. The numerous cxpcrimeiit« of 

avy, assisted by the subsc^iueiit discovery of iodine, nnd its 
•trikiiig analogy to chloriru>,f;nidu;dly t-sUiblished the theory of 
Davy. I nm not wKunr of any ehcoust who ut present Bupjiurts 
the old hypothesis of IlertlioUet. 

Nothing is easier than to procure gnseous muriatic acid in 
■mall qiuinllties. We hnve only to put a Utile common Bult 
into the snmll tubulated 
retort A, capable of hold- 
ing three or four cubic 
Indtrtt and then to pour 

by the Inbular » quantity V ) "N^ ^ 

of oulphuric acid, while tltc 
bent extremity of the beak 
H plunged into a mercurial 

trough under the mouth ofn small ghws jnr standing inverteil 
ovpt it and filled with mercury, liiegas issues at first rapidly 
from the beidt b. A portion must be allowed to escape before 


* JUotM i> umJ by Cicero for brine of laU taUr. 

t PhU- Tthu. vol. In. |>. I>7. f Mati^ on AJr, U. 276. 


<^>»p- 1- we begin to collect the gas, that we may be sure that all the 
common air has been driven out of the retort AAer a short 
time the evolutioD of muriatic acid gas stops. We must then 
^ply the heat of a lamp to the belly of the retort, and the gas 
will be driven over with such rapidity, that we may in a few 
minutes fill five or six little jars with it, and thus collect a suffi- 
tnent quantity to examine its properties. 
Propcrtta. 1. It is invisible like common air, and capable like it of 
indefinite contraction and expansion. Its smell is peculiar, and 
when let into common ^r it becomes visible by forming a white 
smoke in consequence of the avidity with which it absorbs 
moisture. It reddens vegetable blues and has a very sour taste, 
and possesses powerful corrosive qualities. 

2. I found its specific gravity at the temperature of 60° and 
when the barometer stood at 30 inches 1*2643. The true spe- 
cific gravity has been shown by Gay-Lussac to be the mean of 
the specific gravity of hydrogen gas and chlorine gas, or 1-2847. 

3. Animals are incapable of breathing it; and when plunged 
into jars filled with it, they die instantaneously in convulsions. 
Neither will any combustible burn in it. It is remarkable, 
however, that it has a considerublc efiect upon the flame of 
combustible bodies ; for if a burning taper be plunged into il, 
the flame, just before it goes out, may be observed to assume a 
green colour, and the same tinge appears the next time the 
t^er is lighted.* 

4. Its refracting power, according to the experiments of 
Chevreul, is 1'527, that of air being unity.f 

5. Water absorbs this gas with prodigious rapidity. If we 
fill a phial with it, and take out the stopper while the mouth of 
the phial is under water, the liquid rushes in with fully as much 
violence as it would into a vacuum. At the temperature of 
69" one cubic inch of water is capable of absorbing 417-823 
cubic inches of muriatic acid gas. l"he temperature of the liquid 
increases considerably; and its volume at 69° is 1*3438 cubic 
inch. It is obvious from this that 100 grains of add of this 
strength contain 103 cubic inches of the acid gas; and a cubic 
inch of this acid contains 311-04146 cubic inches of the acid 
gae. Acid of this strength has a specific gravity of 1*1958) and 
contains 40*39 per cent, of real acid united with 59-6 1 of water. 
In winter liquid acid may be obtained having a specific gravity 
of 1-2 12, and probably by artificial cooling the saturation of the 

. * F^ieidey, ii. £93. -f Ana. de Chim. ct du Phyn. xxxi. I6& 


, M-nlor tntglit l>e carrii^l hIiII farther. Tlie follou-htir tublv witidi 
caiistriirlcd vritli consid^mble care, from udual experiment,* 
rxliiliitii the eomj>oaition of liquid muriado acid of viiriouB spe- 
[ rilii- ^ruvities. 








Ol IKflWL 










11 62 








































Ice also fltwK>rl(S llii« ffrn, am\ 'u iit the mmn time liqnelie«l. 

1^ qnaiiiity of this gas nlKsorlied by u'nler dimiiiifhc^ wt tW 

of ll»L- water mercaies, and at a Iwiliiig Iienl »-n{er will 

tmt ahaorb any of it. When water impregnated with it ts 

Iwstodi tire gas it) ^i^in c.T|)oUeil umilterml. Henee muriatic 

•eid gm mny Ik- pnieured hy heiitini; the common nuiriiilic acid 

nimmerce. It was by this procesa that Dr. l*ric-)itley first 

tniiKtl it. 

Liquid raiiriatii- add, an tlie solution of tlic gns in water it iTtf-iuioo. 

Iieitii^ more employed in Hiciiiie^d experiments tlian any 

r acid, requin-H tw be olituincd (jtiite free from all impurity; 

id an the muriatic acMl of commerce does not po^wM that 

lispeuKible n-qui'itc, it in ri-ipiUiie to prejiare it in the labora- 

ry. 'Die nppitnituti employed fur thJM purpose tn represented 

in life figure in next pii^'. A is a t»bidnte<l retort of Hucli a 

i/r that :i coupk- of pouiidit of common ttah may bo put iuto It 

rilliuut fillinj; it more ilian lialf full. The beak of this retort 

through n perforated cork into the opening of the side of 

Jut B. Tliia jar hm two mouths. Through one of them 

!|he tiilx' of safety a piif«es to the very bottom of tbejju-. It 

a First Praidpln, i. B7. 







passes through a perforated cork, so as to be air-dght in the 
mouth of the jar. About an inch of water is put into the jar 
B, into which the tube of safety a plunges. From the other 
mouth of the jar B issues the glass tube b, also fised tight in 
the jar by means of a perforated cork. This tube bending at 
right angles passes into one of the three mouths of the tall jar C 
filled about two-thirds with water. The jar C has three mouths. 
Into the first passes the glass tube b; into the second the tube 
of safety d ; and into the third tlie glass tube e. This tube 
passes to the bottom of another Woolfe's bottle O, which has 
also its tube of safety g, and the bent tube E, and which like 
tlie jar C is filled two-thirds with distilled water. All the mouths 
of the Woolfe's bottles must be carefully luted with &t late, 
and then a piece of cloth dipt into hot glue is to be laid over 
the joinings and firmly tied on with a string. This, together 
with the corks, enables the apparatus to withstand the requiute 
pressure without allowing the gas to escape. The bent tubes 
b and e would be very apt to break should the apparatus undergo 
any ablation. On this account tliere is a joint in each at m, 
made by having two tubes instead of one, the two extremittes 
of which are brought nearly in contact and tied together by 
means of a slip of caoutchouc. I take a ribbon of caoutchouc 
and dipping it into caoutchouc varnish, make the sides overii^ 
each other, and then tie it in that situation and allow it to dry. 
It will now form a caoutchouc tube through which the muriatic 
acid cannot penetrate." 

* TbcseCBOutchoucjointaare exceedingly convenient. The thinflataheeta 
of caoutchouc sold in London answer best. These joints do not answer ao 





AlWr tliu nppnmtus ia properly luted, 8til])huric ndd is to be 
pntirml by little at n time througli the (iibiiliir mouth into the 
R-tort A.* This iDiiy be either done by simply 
Inlciit^ out the »t«^]>er an<l replacinj^ it as 
quickly u poHKit)!*- after the acid has been 
poured in. Or wp may fix tlic bout fimncl 
A into tlic mouth of the retort, itinkin^ it air 
ti^lit by paviing it tlirough a perforated cork. 
AfU-r the aul|>hitric acid has pa-ised tlirough 
thi« fiiiiuel, a portion of It remains at the 
WiiiUiig m, wlildi effectually prevents (lie 
muriatic gsa from escaping that way. 'flic 
advantage of using sacb a bcnl funnel is, that 
we may add sulpburic acid as it h wanted, 
without (leraugitig lliu a^i>arstU9 or stopping 
the pToccm, 

The small quantity of wntcr at tlic bottom of jar B in first 

tDTBted with the gas ; tlteu it passes by tJic tube A into th« 

C and is absorbed by tlie water in tliat jar. A^ tlio tern- 

,ture of tlie water ii much nu-ieil by tliim absorptiun, tliore 

«n advantage in stirroinuUng the jar C witli cold water, or 
Dtill l>etter willi a mlvture of w^Bter and ice, when ice can be 
rorured. In prui>ortigu la tho trater uli^orW the g:u<, its bulk 
and by the dme tltat it b satunitcd wo sluill find tlio 
jar C nearly fille<l with li()uid muriatic acid. If wc coiuiituc 
the process after the water in C !■' Mitutated, the gfut will [liws 
0ver into D, and saturate the n-at^-r which it contains. In this 

y we may saturate the water in as many Woolfe'slwttles as 
tn> pleaxe, supposing them attached to each otiier in the way 
the D ia to C. 

When tliP water in C ts saturated witJi muriatic acid gnfl, 
ItH colour is always a light yellow. If we continue the current 
«f gas after the water is saturated, this yellow colour gradually 
diminrshes and at last disappears, or rather the colour ia con- 
veyed to the jar D, tlie water in whidi in its turn becomes 
lyellow. In this way wc may drive llie yellow colour from one 
jar U another as far as wo please. The coluuriiig mutter, 
wimtever it may be, is very minute in qunntit)'. If we add to 

.'Wiril when MiiHianiaal g» 'a passcJ ilirou^h than. Bwaute noulchciuc 
■ounania, and U renitcrod >*A\ by it, so thu it Mon give* wny, 
■ The best proporlionii wc 

7-S nit, 

9-2 gulfihuric ncid, 
1 Viatel. 




°^ •■ the coloured liquid B very minute particle of dn, it will be Sis- 
solved and the colour disappears. I suspect that the colonrit^ 
matter ia bromine ; but I have no other proof except the cer- 
tiunty tiiat bromine exists in miimte quantity in commou salt, 
and that a very small portion of bromine is capable of eommii^ 
nicating a simihir colour to colourless muriatic acid. 

Muriatic acid thus obtuned has a strong pungent amell 
simihir to the gas: it emits a white smoke when exposed to 
the air, which becomes much more con^icuous if a little 
ammonia be phiced in the neighbourhood of the add. 

The following table drawn up by Mr. Dalton gives us the 
boiling point of this acid at various densities. 

DtiUint rolnl. 

Sn gtMUj. 

BoUlnc polDt 

























Wc SCO from this table that the boiling point is a '"«'"""'■ 
when the liquid is a compound of 1 atom acid and 16 atoni 
water; or when the liquid contains about 20^ per cent, of BcMb 
The boiling point of acid of every other strength is lowen 
Acid containing about 30 per cent, of real acid boils at the same 
temperature as water. If the acid be stronger its boiling tem- 
perature is lower than that of water. The boiling point of sod 
of 1-203 is 107». 
rompHiuon. 6. It has been demonstrated that muriatic acid gas is a con^ 
pound of equal volumes of hydrogen and chlorine gases, united 
together without any alteration in bulk.* Hence its atomie 
weight is 4*625. 

7. Mr. Faraday ascertained that muriatic aci<l gas is condensed 
into a colourless liquid by a pressure of 40 atmospheres, at the 
temperature of 50''.f 

■ SecTol. i. p. inT- 

t riiil. Trana. ISM, p. S4*. 


JQy. iletiry aIiowihI iliat wlwn cluctric ftpartia tav ))a<»e<l 

imc lUrouf^li muriatic iici<t pa, it uitdurgoes ]>aniiil 

tioii; n portion of chlorine «ml liydrogt-n-pwottWinp 

eroIrnJ. * But tbifi (leconi)>(MitioD uiiinot bo carrici) fur, b<.T»use 

vbcft iiyixogea anil elilorine gases are accumulatvcl in nay 

^nandtj't tlie electric !(|itirk cauftea them to combine again. 

ft. When miimtic at-iii ga-* and oxj'gon giw «r« mixed ti^Uiw 
L3il iKUMvi tiiroii^h a rvd-liot pum-Iuin tubr, or when electrical 
iliiicliiirgvfl an) transmitted through such a mixture, water '» 
famed ud cbloriuc gas dWogaged. Dr. Henry found that tlic 
mat dccompodition was produced at the temperature of £50" 
■ vWe Bueb amixture waa in contact witJi a platinum clay hull.f 
H 10. MHien potassiom b heated in murinlic gas it libenitcs 
HMMbird of ibi volume of hydrogen. Davy found tlint whea 
^^Bb or tin i« ht-ated tu this gas tliey are converted into ehli>> 
riilrs, while a quantity of hydrogen gas is disengaged equal to 
I «M-liidf of the murbtic ncid gu.^ decomposed.:^ Clifircoitl even 
when igiiilH t« whiteness, prodnce§ no chan^ in this gaa if 
it be {terfectly dry. Nor is it prolxible tliat it u-ould be decom- 
|ioaed by uotc, pliotphoniii, sulphur, or oelenium, tliough I am 
aot awam lint the ex)»erimeut has been tried. It is decom- 
pMed by all the tnetaU which decompose water, namely, iron, 
itDC. dn, and antimony, Rn<l also by the metallic oxi<li;rK. In 
tbe last ease water i» formed and a metallic chloride. When 
ibeae oxtdet con«M of tliosv of the more powerful bases, tlie 
dfeomposition ia accompanied by the evolution of much heat. 
Thus if pure anhydrous barytes be put into tliis gas it becomei 
fiilwi'*'' of barium with the disengagemeni of light, while nuter 
ia eotideiucd on the inside of tlie jiir (^>ni<iiiuiig the gas. 
1 1. It is at present » nuhjeet of diH-iL««ion among cbemiatR 
bether niuriatte »ci<l Ih' cap«it>le of combining with bases, and 
rming mnriitU*, or whether at the instant of comtiiuiitioii a 
ubie dceom position doea not take place ; tlie hydrogi-n of the 
urintic acid uniting with tlie oxygen of the Ixixe and forming 
Icf, while the chhirine combining witti the otiier constituent 
the Ijhim! produces a cAAwn/r. In manvcuiM-sof combtiuilion 
le phenomena arc sudi lliat either explanation may be applied ; 
bile in olliera there can b« no hesitiition in adopting tlie hut 
xplnnatton n» the t/ue one. Thus if we di-MuIve 1.3-75 silver 
n nitric acid, and mix the tiencrul Mtlntion with 7-5 of common 
t, we obtain l8-'25 of n white mutter, which must be chloride 
of silver. Tor it conuiins 

CIM.I1. I 

rwf muriiln 


• niU. Tnii«.18l]{,p. 810. 

t Ibid. IM4. 

X VM. IfllO. 









In the same way wlien 13 load is (lii<!tolv<>(l in nitric ncid an«l 
ini.TiMl witli tlie rcquisittf quantity of common sill, we n)>t»ina 
wliih; nutttcr wcigliiiig vxactly 17*5, and therefore chk 

If we d»«olvc 4'25 zinc in muriatic add, snd cttipornt^ < 
tiouflly to dryness, we obtain a white matter weig;hiiig 9*875. 
If we heat this matter to incipient ignition in a glass tube it 
gives out l'125 «f water, and there rcimiim 8-75 of chloride of 
zinc. Wc may therefore consider the white compound cither 
as a compound of 

1 atom chloride of zinc . . 8*75 
1 atom water .... 1*125 

or lu a compound of 

] atom muriatic acid 
I atom oxide of zinc 




The atomic weights and the elements are the same wliichererl 
of the two ojiInioiH vt-e adopt. The only difference consists in 
the way in which tliese atom-tare combined. This subject will 
come under our review more ]iarricularly hereafter, when we 
give an acconnt of tlie dillereiit chhridea or muriate* whidi 
possess euUnc properties. , 


I bave no doubt that tlie number of chlorine acids will rery 
mudi incrl^a.''e it.* soun as chemists turn their attention to the 
subject Hut hitlnTtii very few nttempu have been made to 
determine whether those chlorides which contain acidifiable 
ba»eH be capable of combining with, and neutralizing tboM 
chlorides that contain alkalifiahk^ Iiumi's. , 

1. The chlorides of suljihur and phosphorus do not aecDl ' 
possessed of acid propertin. At least the attempts which I 
made to earn bine them directly with alkaline chlorides did not 
succeed. It is evident from many chemical phenomena that 
the chlorides of potassium and sodium are nlkuline hod)i-« cnpnble 
of combining with, and neutralising various vx'n\ clilorides, asj 


for fXAinpIv the MoriAea of golA and platinum. Hut the clilo- 
I'lde of sulphur is iii«apabi<! of <IUs«]vi»)r tiiette IkhH&s ovon wbvii 
■nsted by heat. Neither did tlu-y dissolve oik- or two mctjdlic 
dttorides which I rxpusnl to thpir iiclion. But no sulpliurvt 
<raa formed when the cidoride of sulphur was digested over 
MOW uetallic cliloride^, wliosc h««i.'« have a very strong; affinity 

3. Bonsdorf has shown that corrMirt Mufilimate* possesses 
lad properties, and Js capable of conibinin<^ and fanning snltft 
with a great variety of aUmline chlorides. Thb indee<l hiw 
hecn long known, thoitgli Ilonsdorf U the first who hai* explaincil 
the nalurn of these comliiiuitioiis in a salis&ctory niaTincr. I 
thall descri[»e the new ^18 which he formed in a suh^uent 
part of tJits wurti, when 1 comu to describe the chlorine acid 

^M 3. Tliere can be little doubt that the chlorides of gold, pta- 
^Homii pftlladiuui, rhodium, iridium, and osmium poMi-sM ncid 
Vpnpertim,f aiuliliiit tin- niIu whiih have W-vu di^itiugnishedby 
(lie Dwne of double dilorides of gold and sodium or potassium, 
«f platinum and sodium, or potassium and m\ ammoniac, &c. are 
in reality kUia form«?d by the union of a chlorine acid with a 
dilurinc base. Tliese salts, whieh amount to a consideTuble 
Binnber, will he deseriWd in a subsequent part of this work, 
Wtaog the clilurine arid Sidi«. 

4. I have not luid time to make any trials with the chlorides 
•f oneitie and anlimony; hut ishould not he Mir))rised to find 
then capnhle of combining and forming salts with the alkaline 
chlorides. The aubjeet at any rate requires to be investigated. 



^B RrQRiine has been known for so short a time, and is still so 
^■Caroe and so deaTi that we need not be surprised tlmt this class 
^bactda is still almost unknown. In fact there is only one acid 
^^pkin{(ing to tliiii class which lias been hitherto examined. It 
will constitutv the subject of the following Hvction. 

TUft acid was discovrretl by M. Balanl, and to him we are 
• Ana. ik CHiim. et ik Pbj-3. xuiv. 148; xliv. 1B9, S44^ . 
f See Benadof roferred lo abait. 


ii)d«l)t>Nl for fvpry tliinft rrspwtinp it ycl known. 1 have 
given a Rhort account of its properties in tlio Rzst roliime of 
thifl work (p. 109), and I lutve nothing fiirther to add to ttiat 

It h n compound of one volume of brotnine vnpotir, nn<l onff 
rolumo of hydni^n ffi» iinilMt ingfihcr without iiny altrniiioit 
in the bulk. IIviicc \bs ntoniic- wcij^ht U Iti'l'ia, and i' 
itpedlic gravity in the gaseous state miwt be 3'B123. 'Din, 
add comhiiH'-t M-ilh bnsps, and forms a genus of salts which 
havp been diNtiugutiihe<l by tJie name of /it/tlrohmmaUs. It has 
not been yet dctermitiett whether tlieiw italtn nrc really h}/dr^ 
hromaffK or only bromidrs, or compounds of bromine wilh the 
metallic liasrH of the alkalies. Tlie difhctilty is of tlio mine 
nature as occurs witli regard to the salts formed by means 
muriatic acid. 

CLA88 IV. 



The analogy betiveen oxygen, chlorine, bromine, and iodine^ 
is HO great that we can Kcareely hcsiutte to admit that iodinct 
like the other three Mupporteri', has tlic property of formiog 
acids when it combines with various of the aci<liliubk- Imiti 
But except hydriodic acid, the properties of which have beeB-i 
described in the first volume of tliis work (p. 1 10), hardly anf 
of tlie iodine acids have been bitlie.rlo inveiitigaled. M. Ilonft* 
dorf lias shown that die {lerioditlc of mereiiry poo^esav* the 
chanictcm of an acid, and is capable of combining with aiid _ 
Batumting several ofthoidkaline iodides, as iodide of potassiumifl 
of sodium, of /inc, of iron.* Similar combination<i Kive been 
made l>y M. BotiUay. There can be no doubt llial the num- 
ber fif iodine acids will increase rapidly, now tliat the attention 
of obcmiKts is turned to tin- Mubject. It is known olrewly that 
the iodide of arsenic possesses acid properties, and tliis will 
probably ho tlie case with the periodide of anttmony. W' 
would expect »l*o tlie iodides of the family of noble metals 
he acidtt, as this is the cjise with their chlorideti. It were to 
wished, therefore, tliat some chemist would set about the invr^ 
ligation of tlieir properttOB, and of the salts which they may 
capable of forming. 

* Ann. ie Cliiin. oi <l« Vhyt. xliv. d60i 




I bave given in die first volume of this work (yage 89), 
tkc reasons whidi huvr induced ehemists to believe tliiit_/?woric 
add u * cuinpuuiid of fitoyriw aiid hydroijm ; duU fluorine ia 
U eloctru-Dcgutivc ^ubsiance similar in iw propertiea to oxygen, 
cUoriiiL-, bromine, and iodiiid, uid vupabb? like thvra of coin- 
Uait^ with ttie rivioiw ai:i<liliublo hiUH.-ti, luid of convertiii); 
Iban into oaA*. As Jtitorine biu not yvt bii-ij ubtaiiteil in n 
I^NUate statu, tliis o)hiuod cannot be cotisldcrcd sat dcinoii- 
Mnied, yet tbe opinion is so plauNble and so strongly sup- 
porled by anaiogy thai it baa been very {generally adopted. 

We are at present ucquaino.'d witii eight ndcU, wbieli are 
cotuidered as combinutions of fluorine and an acidifiable basis. 
Ilicce ar^ 



1. Hydrofluoric acid, 

2. Fluoboric, 

3. Pluosilicic, 

4. Fluomolybdic^ 

5. Fluotungsdc add, 

6. Fluodiromic, 

7. Fluooolumbic, 

8. Fluotitanic 

I ennhinaUon of fluorine with tlie uine rvinuining acidiliable 
Ihw yet bc«n diswrered. 'I'iicM I'igbt acida will be 
ribcd in the following svctious. 


Tliiit 'is till- imd wliicii Iia« been <I(,^»).Tit>ed in Uie fir»t volume 
of tlii4 work (p. 67), under tlie name oiJtwrU acid. I bave 
■Ircody given an aocoont of tiie process by which it may be 
icured in a state of purity, and detailed \\a properties so iat 
ihoy have been detennined. Nothing farther reuiiiius but 
' give an account of tlie salL'« wliicli it torms, and wbich have 
I'vn cxjunined in detail by Gay-I-iw'w; aiul 'I'Lenanl, aiul by 
rncliui^ I'bey will occupy our ultciitiun in n aub»e<j,uent 
. of this volume. 


This dH<) was discovered in 1808 i>y Giiy-Lunae and Tlie- BMan. 
■ard.* Its properties and preparatiou hare been already givcu 
VuL I. p. 218, of this work. It has not yet been aiuilyzcd, 

* KocbeKha Ptajtico-cluouquOi il 3T- 


ClU|lL t 


but I AID (Ibtpmed, for the reasons asdgned (Vol. I. p. 3211), loJ 
coiiHitlcr It lut u cumpound of 

1 atom fiuorine . . 2-25 

2 atoms buron . . 2 

and to consider it« atomic woight m 4-25. 

Bcrzcliits says that wlioii fltiuborio urtd gas u absorbed by 
water, a considerable quantity of bonietc acid is deposited. If 
tlie liquid acid be cooled or very slowly evaporated, an additional 
quantity of horacic acid separates ; but if it bt- concciilnit4'<l M 
sn clcviited tempcmtiin*, it volutiiizcti witliout leaving any 
residue.* It would appear from ibis that tlic hydrofluoric acid 
formed at finit by the decomposition of wntoristigain destroyed, 
and the original fluoboric acid constituted anew by the aclioa 
of heat. If tliese decompoutions be accurately stated by Her- 
zelius, tliey seem to me to demonstrate lliat the composition of 
fluoboric acid can be notliing else than 

1 utom fluorine . . S'26 

1 atom boroD . . 1 

In order to reconcile this composition witli the atomic weight 

4-85, can we admit tlie presence of an atom of oxygen in 

fluoboric acid ? 

llic JiiKiboratcj which Iiave been examined by Bcrzclius, 

will be described in a siilwequent part of lliis volume. 


nMtn. Tilts acid wan first obtained in the gaseous state by Prto^tlcy, 

but it wiis not properly dinliiigulshed from hydrofluoric acid 
before the publication of the experiments of Gay-Lusoc and 
Thciiard. I have described tlic method of procuring it in the 
first volume of tliis work (page 229). 

tnftnim. It is a transparent colourless gas, havinga »mcll very similar 
to that of muriatic arid, and forming a white smoke when 
mixed with common air. It ii« not altered by exposure to a red 
hCBt. I found its specific gnivity 3-6. ^Vhen potassium i» 
beatei) in it combuHtion takes place, and a chocolate-coloured 
subsltutee is formed which difTers in its nature according to (he 
proportion of potassium employed. Fluoride of potassium is 

• Kong], Vcteas. Acad. Hsodl. I8S4, p. »». 

: fnmtAt and n <|UBntit)' of silicon discnga^d, which is cimv. 

commonly united to potassium. Fluo«ilicic add giu conibinn 
wilh twice its volume of ammoiiiacal gas, anti funmt n volatile' 
mIL i'lm salt is t^>viouslY composed of 

Fluosilieic acid . . 6*5 

Aumoaia . . . 3- 125 



If we consider it as iicutml (it is the only luUiitp compouiMl of 
ikU acid yet formed), it ia otivious that the atomic weight of 
SMulieie add U 6-6. 

Now if the rntiu of its coiistituenls be as I hare stiown (Vol. I. cii^««mM. 
p. 3*29), 1 atom fluorine and 1 atom silicon, it follows cither 
that this add is a con^und of 

3 atoms fluorine . , 4*5 

^B 2 atoms ulicoii . 2 

^H^ 6-5 

Vcrdtat the aromoniiieal tsdt w n bifluosilicate of ammonia. The 

' fint of the^e o])itiionH is by fur the most probable. 

When fluosilieic acid gaa comes in contact with water, it 
tkpOBites a quantity of silica in a gelatinous state, and by thut 
deposition a quantity of hydrofiiiuric ueid i» formed. The 
■tlicon decomposes water, and uniting witli its o:fygcn is co»- 
rerted iul«i Kilira, while the Ruoriue uniting to the liydrogon 
of the water become:! hydrofluoric acid. The liquid, supposing 
it freed from the depositMl siUca, Ls, acconling to the experi- 
ments of BcrYcliius a compound of 

1 atom liydrofluuric acid , . 2-375 

2 atoms fluuulicic acid . . 6*5 

H Uwl it constitutes a compoimd acid whose atomic weight is itr'i<«ii<u>- 
^8TA. 'lliia new acid may be distinguished by tlic name of 
klfdn^hosUieic acid. It combines willi the ditferent bases, and 
loniH a gvnuH of Milts wbicb miiy be denominated hydrofluo- 
aUicatf, and which have t>eeii examined by l)er/clius. They 
will come uiuler our rct-iow in a subsequcnl part of tlits volume. 
Tlie method of forming this compound acid in a liquid state 
is to causeacurrent of fluosilieic acid gas to pass tlirongh u bent 
ghaa tube, tho extremity of which comes very near, but does not 
actaally touch the Kurfiic^- of the wnter, to he iinpregiuktcil with 
the acid, taking care to aj^iUitc the water duruig the whole pro- 

300 riX'OHINP. AC1U8. 

f c^i^ >■ CC88, ih onlcr to break thti crust of silica n hidi sjieodily fonna 

"^ on its surface. Or wc may put about an inch of raercur)* into ■ 
the bottom of a glass jar, aiid after having; plunged the hoik of * 
the glass tube which conveys the gas under tl)c surface of tl)c 
mercury, we may pour over it tlie water to be impregnated. M 
Evcit ill tliU ctie the water mtiftt he occasionally 8tJrrv<l, otlier^ ' 
wise u tube of ftilica would bo formed, through which tlie gat 
would csciipo iinaltcn-d. Were we to pluiigc the emt of the 
tube in the water it woulil be spectlily choked up by the silica 
de|io!(ited in it, and tlic process would be stopped. When w« 
have sufficiently impregnated tlie water with the acid we mint 
tlirow the whole upon a clotli) and after the liquid has passed 
through wo may sqiievzc tlie gelntinom* silica tn remove a!* mueli 
of the liquid as possible, but we nui»t not wiuh it, because the 
silica in tliat state is sulublo in water. 

I'he liquid acid thus prepared has an acid taste. If wc drop 
into it any salt having potash, soda, or liifaia for aKise, agela- 
tinous precipitate falls, so transparent and colourle!i.4, as to be 
at first tnvUible. Salts witli base of biirytes, on the conlrar}', 
throw down a white and crystalline precipitate. If we add just 
the quantity of any base whicli Mittirateit the comjioiind add I 
(its atomic weight being H-875) wc form liydrolluosilicatm. 
liut if we hdd a greater qmuitity of base than is requisite fof 
this purpose, silica is thrown down, and a simple hydrulltiate 
formed. On this ucconnt Her/elius cmisider* tlie acid as a 
nmple mixture of hydrofluoric and fliio^kilieieacids. Hut I tliiak 
it moro natural to view it as iinalogoitrs to hydrosulpliuric add, ■ 
stilj>hovinic acid, and sulphonaphthalic acid, in which tJie 
atomic weights of the acids, in consequence of their slate of 
comhiniition, is reduced to one-half. I liave no doubt that tlie 
number of these coni[>ound acidi* will considerably increase 


autei,. Tbia acid was first exumine<l by lierseliiu.* It is obtained 

by dissolving molybdic acid in fluoric ucid. 'Hiis solution is 
miule with great taeility. It has an actd, metatlic, and disa- 
greeable tuste. When evaporated it dries into a yellow syTupy 
mass, which shows no tendency to crj-stallize. M'heii hcnt«'d, 
its colour becomes bluish. If we dry it wc can no longer di*- 
S4>lve it comjiletely in water. Vet it continues a compound of 
fluoric tuid molybdic acids. 

• Kont;. Vclent. AcmI. lUndL Itai^ p. UHb. 



Ik double odd eumltiiie« with tlic 1ai»0H, itiid forms nMt of Om v. 

^JuL-li amy be callod fluDmoIybdutcs, Only one of ihcse '_ 

^M been vxamiiio<I hy Ikrzpliiu), namely, the Suomolyb- 
n pttMtlk. To oltiaiD it we Iiave only to mix a nolutton (^vituiux.. 
klf bdatc of potuh with fluoric ackl, uid ev^>omte tti« 
Ire. Ciyalalii of fluunioIyfxUU' of potash fitll in »inall 
h The amlymg of ihu Nilt is alt>?nde<l with conwlerable 
llty. Ilenclitis bonvrcr subjecl^i it to aoalywH but his 
^tion of the method which he employed m not %'efy intel- 
t. He Bccms to lisivo di.tsnlvc^i rh<^ suit in water, nn<l to 
thrown down the fluoric luid mtilylMlic ncid>t by means of 
te of lead. Krom the re«idusl liquid tlic lend was thrown 
i by carbonate of ammonia, und muriiitie acid being added 
he whole evaporated to (iryncs§ ntid heated, the potnsh was 
InmI in the state of chloride of potassium. 'I'lie predpi- 
bonsiMing of molybdate and Huate of lead, was (Itfrcsted iti 
■ttlphnret of ammonia, by which tlie mulybdenum was 
red in the state of mlphuret. It was vva|>orated, and by 
Ifttioii eooverted into molybdic acid and weighed. Ilie 
^ was determined by hvating it alonj^ witli oxide of lead, 
boertaining tlie loss of weight. The fluoric aeid seems 
hr to have Iteen infernal from the weight wanting to make 
t eonstiluenta to the origiiuU weight of tJie salt subjected 
{klyafa. The following tabic exbibito the re«uU of the 
fin of the salt thus managed: 
^^ Potash 31-63 

^fe Molybdic acid . 45-^ 

^^ Fluoric acid i6'57 

Wattfr . . . 6-(M) 


the atomic wei|i;ht of potasli i« 6, of molybdic acid 9, 
f fluoric acid 2*375. Hence tli«sc numbers are propor- 

1-033 atom potash, 

I atom mnlyMic add, 

1-866 atom fluoric add, 

1*089 atom water. 
|it the fluoric acid, which amounts to 1^ atom, it is obn- 
ut each of the other constitueiiiii constitute only 1 atom. 
if we attend to tltc way in which the fluoric add \rm 
Med, wv mudt »ei- at once timt tliere U a certainty lliat it 
irtiUed. I'or all tke low which niuM tuid<Miljti-<Ily liavc 


Oi*t.t. \jeen susbtincd U coii^Idcrred as 6uoric acid, flad the losa 
iimouiitcd to 2 per oenU (which is not an excessive allowance) 
llie quantity of Suoric acid would be reduced to 1-19 atom, or 
less tliaii 1 } atom. 1 f to lliis wu lulil ih»t molylxlic uciil U-ing 
volatile, there niut » constdt-rublc diitnce of some of it being lost S 
diiriufr llic iiiiuly.siK, which would tiiTect the proportion of all the ™ 
other coii8titiiciiti>i, wc can scnrccly doubt that tlif true quantity 
of fluoric acid in the salt is 1 atom. 

There is reasou then to conclude that fluomolybdic add ts 
■ compound of 

1 atom fluoric acid . . S'376 

1 atom molybdic add . 9 


Its atoniK weig;htis 1 1-375. So that by tlie union of these 
acids their capacity of sat uration i»reduccd lo oite-half. It 
would appear from tliis, that fluoric acid resembles sulphuric 
udd in this curiouH property. Fluouioljbdale of potash is 
(ibviousty a coin]>ouii<l of 

1 atom fluomoiybdic acid 11-375 

1 atom potash . . 6 

1 atom water . . 1-1-25 



WaMij, Thin iicid was also firitl examined by Bcrceliui^* tt 

8cmbU's the Inst, but the coiiHtitucnts seem to be more feebly 
united. Hiere can be little doubt that it is a compound of I 
atom fluoric acid and 1 atom tungstic acid united together, lutd 
capable of saturating no more of a base llian either of the cuu- ^ 
Btituents would do if it were separate. (>r by their union tbe H 
capacity of sal uration of the two acidn is rc<luced to one-liaif of ~ 
what it was when thoy acted «cpuratcty. The atomic we^ht 
of the fluotuDgstie acid i» obtained by adding that of itii two 
constituentii together : 

1 atom tungslic acid . . 15-5 

1 atom fluoric acid , . 2-375 


It is therefore 17-675. 

• Koag. VcUos. Acad. ILuidl. 1824, p. 310. 


^%n»en fluoric acid is pourc4l upon tiingNtic acul we obtain a 
jtIJow milky liquid, which is eoliible in a ^re»t (|uaiitity uf 
wster. Calcinml lungntic ai-ld U vory little itoInliU^ in fltionc 
acid. If we cniporuu.- tlu* sutiiliou )iy ugerillo hi-atwe obtain 
a ycllotr syrnpy muss, whidi litully cracks, gives out fluoric 
wM, nnd assumes a ^ccnisli colour. If we pourwateroii tliis 
mtter we obtain a milky liquor, and we obtain an add Holntiou, 
Wt tii«> gmiteHt |mrt of tlie tuiigslic ad<l refuses to dissolve. 
Vet it rotuins fluoric add, wintU it does not give out uitleas it 
be strongly calcined in an atmosphere of unimouia. No lung- 
■tk acid escapes with the fluoric. 

'riiis eompouud acid combines witli differant bases, and forms 
Hits wliieli Uavel>een ailed ^uotunffstalfs, 'ITic only salts of 
lUs cbiM hitherto examined arc fluotungstutc of ammonia and 
flnotungsuitc of [>ota»li, both of which crystallize^ scales 
ttmilar in uppesnnce to boraeic acid. I-'luotirngstale of pot- 
■■k k csfily formed by dissolving tungstutc of potasi) in fluoric 
leid and cva|ioiaung ibe solution. It is very little soluble in 
cold wiitor. Boiling water dissolves it better, but on cooling 
it is mostly depoMtetl a^n in crystalline scales. Its taste is 
Iritter iuid slightly mel.-tllic. It is not altered by exposure to 
l&e air, nor by digesting it in water. According to the ana- 
lysis of Uerzelius, its constituents are 




Tungstic acid . 


I-luoric add . 


Water . 




I fliHtrie acid was estimated from the loss sustained duiing cmiiaiuan. 
la U l Jyab . 'Iliat loss was coiuidcred as fluoiic iitid. 'I'heM 
sbcrs arc cquinJeut to 

1*05 atom potasli, 
1 atom tungstic avid, 
0-87 atom flotnic add, 
1*09 atom n-ater. 

sible tlukt a little of tlie fluoric odd may have made its 
with the water, an<l it is not unlikely that tlie tungstic 
wM may have retained a little potnslt. This unalyius, however, 
leaives little doubt that the Hue constitution of the suit is 



"■^' I Hlom Hiiotiingstic ucid 17'a76 

I iitom |)obuih . . 6 

I uUim water . . I '125 

eo tliut tliis mlt rCBctnbles in its composition fliiomolybdate of 
potusli, and fluDtungntic add is exactly similar in its nature to 
fluomolylwUc acid. 


iitiiorr. TIlia compound was discuvcred by M. Unverdorben, and 

d«ficnbe<i hy iiim in lln* year 1826." 

W'tifii iM]uid weights of fluor spar mid cJiruniate of lead are 
tritnrfit(.'d together and put into a leaden retort with three time* 
their weight of smoking liulphuric acid,| and then gently 
heated, a ^m k gcner.itedi wliicli may he collected in a platt* 
num rwnel over mercury. This gtis k tnuivparent, and liM a 
light red colour. It caiiuol be collected in glasit vcjoeLt, becaPK 
it li iiiMlaiitly decomposed by the glass, lluu&ilicic acid bctn^ 
formed, and chromic acid deposited. When auunoniacal giu 
comeii in contact with it combtutiou enaue't, and the two gasea 
exphxlc when nuxed in any considerable (juimtity. It u very 
heavy, much more so than fluoisilicic gas, tliougli from its pecu- 
liar properties it has been hitherto impossible to determine ito 
specific gravity with accuracy. 

It ifi not condenneil into a liquid when exposed to the tem- 
perature of 32°. Water abftorbii it, and conTerta it into fluoric 
and cliromic acidx. Ilisby means of tliii< gas tliat pure cliromic 
Bcid is obtained : lite proce<u( has been de»cribe<l iji the firet 
volume of this work (ptigc 3;J5). 

Unverdorben analysed tins gas by dissolving it iu wstrr and 

getting rid of the fliioric ncid by the luUlitioii of silica. The 

chromic acid which remained he converted into protoxi<le uf 

coBiioMUgD. chromium. He lias only given us the result of iliU aiialyius, 

which, he suys, indicates the gas to be a compoiuid of 

Fluoric acid . . 38- 13 
Chromic add . • . 61-87 


• Poggcndorf'n Atinslpn. vii. 319. 

I Conuiioti concentrated sulphuric odd will aotwcr ibc purpoae. 







low the wcisfht of Uic gas anaXytod wm dctiMTOined dwfl not 
; pmbably by ihe increase of weiiflit in tliP wnhrr when it 
WHS improgiiat«d hy tlii* gn». TIk-m; titiinboK arc proportiotuil to 
1'18 atom fluoric acid, 
I atom cbroRiic uciil. 
bly, tlicrefore, it coDHtittM of rii ntom of cacli add iinitml 
thcr, or of an atom of fluorinr united to an atom of cbro- 
mhitn. Tbr vrcond of tl)«c suppoMtions from tbc constitution of 
cUoric acid U not «n probiable as tlie former. For unless we sup- 
ihe gas a compound of '2^ atoms fluorine and 1 atom 
ium, it v impo»Jbl« tiutt it could bo ooiiverti^d hy the 
ipoflidofl of water into clirumic acid and fluoric acid. Httt 
analysis <>fU'i^0'<'oi'l^^''i'*'iU not accord nHth hucIi a suppo- 
Tbe probability tlicn li lliat tlii* gas is a fluocbromic 
and a componnd of 

I atom fluoric acid , . S'STS 

I atom cliromicncid ■ ■ 4!'5 


fo Mtompt )iiL<« tx^on made to aMccrtain wbctber it be capable 
foonUning n-iili bas<^, luid if eo nrbut its atomic weight is. 


Tliift acid wa4 first formed and examin«d by I3«nM>liuH, during uuinr. 
rcM>arcbea on fluoric acid.* 

Wlifn fluoric acid Is poured upon columbic acid wbicii bad 
previously lii.-«tiN) to rednivut, tin* Cirliimbic acid falls to 
Jcr, but tlic fluoric acid dissolveit notliing. Yet tbc colum- 
acid baa combined witli a quantity of Suoric acid, wbicli 
be aftcTwanU driven off by calcination. Columbic acid 
by fusion witb bi8nl]>bMte of [iota»)i. and then dii^cst- 
tli« saline moss in water, illv^olvvit rcndily in fluoric add, 
. fbmw a limpid and colourless solution. VMicn tbis solu- 
tiwi ia left to spontaneoui e\'aponition it becomes concentrated 
to a certain point, at wliich it ^Io^ki. If it be now kept in a 
beat not exceeding 8C, it becomes sdlt more concentrated, 

I and de|H»ibcs cryslaLt. By continuing tbc evajwration tlie 
• Koi%l. Vmcdc. Acid. llHnill. ifH, p. t»i. 


ch«k t. wlioU is converted into a wliite cuamel-looking mass. Tli« 
crystaU are compleUtly soluble in wiiter. Wlii-ii cxijos^'il to * 
ilry utmoHplierv tlicy i-fflorcsce. This compoiiiKl uv'td combiiiei 
with bases, and forms a class of salw wliieli have been called 
JfuocolmnbatcHf several of whicli liave been ilescribed by Berxe- 
lius ; and one of wluch, the fluocolumbate of potasb, lie sub- 
jectetl to a careful anslysU. 

'I'bis salt w.'w furmed by saturatiiijj; ibc bot flnocoluinlnc acid 
with potush till a precipitate began to fall. On cooling, tiie 
salt was depouted in tteidvs, tmnH'what similar to boracic iKiil. 
'I'liese eryttaU dissolve completely in water, ttiougli witli some 
difficulty. The suit dissolves best in hot water, but boiling 
water dccomposea it. It may be obtained abo by mixing 
bifluate of potash witlt eolumbie acid and water, and beating 
the mucture. Berzelius is of opinion tliat there are two pro- 
portions in which tliis componnd acid combines with potash, 
but tlili conclusion dc])einU u])on ibcoretical ricw« that aro 
liatde, to say tlie leiwt of iheni, to great uncertainty. 

'I'he following (able exhibits the composition of this salt ai 
determined by three different analyses, the mean of wliicli is 

Potash . . . 23-Ji:ifi 

Colunibic acid . . 56-993 

Fluoric acid . , 1!>'470 



The fluoric acid m-iu not obtained, but determined by the loss 
in Uic ttnalyids. 
ccuapMitiM. This analysis docs not acconl with aiiy atomic proportioni 
whatever. It corresponds with 

1-63 atoms po1a.-sIi, 
1 atom eolumbie arid, 
■'}'4 atoms Snoric acid. 
The quantity of fiuoric acid is so ^tcat that it m impossible to 
believe tJiat all tlie loss siuttained was owing to it. Analogy 
wnidd load to the conclusion tbut fluocolunibic, like the three 
eceditig acids, is a compound of 

1 atom oolumbic acid . . 23-75 
1 atom fluoric add . . *2-'A7b 

and tliat iu atomic wt-igbt is 26-125. The salt from luialuf^ 
tiliuuld be composed of 



I atom fliiocolumbic acid . 26-I9S "--v. 

1.1 n B>^ VIII. 

I atom potasJi ... 6 

32- 125 

^uont cxpt'rimcnta must dctermioe how fer tliese analo- 
[ are borne out by facts. 


^^Qufl acid iiUo wu first examinvd by Benwliug during liis ininor, 

on fluoric acid.* 
AVItrn fluoric ticid is pourod upon titanic acid lieat is evolved, 
even though llic tilanic had been [ti^viouxly calctiied, and a 
complete solution is effected by the action of heat. AVh«n the 
solution u evaporated by a gentle hv»t to tlie consistence of a 
aynip it depo»il<.'s cryfltats. n^icli do not dissolve completely in 
vater, but are decomposed into two particuhir combinationti, 
BC of whirl) is acid and soluble, n'liile (he other h»s an excciA 
' bftsc and is insotuble. This la-4t combination i« deami poised 
with coasiderable iliRiculty by exposure to a re<l bent in un 
atmosphere of ammonia. Berxetiii; considers llm acid sohition 
as Biialogoiu to liquid hydrofluosilicic acid, that is a compound 
of hydrofluoric acid and fluodtanic add. This acid combines 
with the different bases, and forma a class of salts to which tlie 
Bune fjS JitiotitamaUs lua been given, and several of'wbicJi 
kave been examined by Beneliui. We has subjecti'tl the 
ioatitaniate of potastli to analysis, in order to enable us to form 
eotnct notions respecting the nature of the compound acid 
which it contains. 

This salt is obtained when the acid li(|uid is satiirateil witli 

poCasb till it begins to let fall n precipitate no longer rcdis- 

wtred by agitation. When the solution is concentrated it 

deposites the salt in brilliant scales like boracic acid. Tliese 

■lah dhnolve in water without decomposition. When 

tJiey give out a little water, which appears to have been 

'nwcliiiuiciillylodgnl. among tlie particles of tlie salt. When 

1 in a phitinum ap|Kimtuft, lliere conies over an acid liquid 

eonbiitM l)oiti fluoric ucid and tiunic acid. From the 

experiments of Berzelius it appears tbut titiinic acid and fluoric 

acid are not ca{vible of fonniiii; a gii'seons compound. Unver- 

A>ri>en found tJuit when a mlxiure of rutilr, fluor spar, ai]d sul- 

^khtiric acid, is heated in a glass retort, tlie gaa which comes 

Koa(^ Vctcns. Av«J. Hnndl. 1884, p. 87a 


omp. L over conbdns titanic acid. He coDsiden the gas thos obtained 
to be a combination of fluoride of silicon and fluoride of tita- 
ntnm. But be could obtain no gaseous fluoride of titanium 
wben the mixture was heated in a leaden apparatus.* 

Berzelins analyzed the fluotitaaiate of potash, and obtained 
Potash . . . 38-7 

Titanic acid . . . 35-0 
Fluoric acid . . . 26-3 


coBpniuon. ThesB numbcTs are proportional to 

1 atom potash, 
1-03 atom titanic atnd, 
1-7 atom fluoric acid. 
It would appear (if &i>y confidence can be put in this analyse) 
that the add consists of 

1 atom titanic add . . 5-^S 
1^ atom fluoric add . . 8-5625 

Perh^ the half atom may have been in the state of hydro- 
fluoric acid, simply combined with the fluotitanic add composed 
of one atom titanic acid and one atom fluoric acid. 

The greater number of the adds belonging to this class aie 
sdll very imperfectly known. Considerable obscurity stiD 
hangs over the combinations of fluoric add with other 8dd% 
which can only be cleared up by farther investigation. The 
subject is attended with peculiar difliculties, because all the 
experiments requu« to be made in platinum or leaden vessels* 
which prevents us from observing the phenomena so well m 
when vessels of glass can be employed. 



We are indebted to an accident for the original feet &«■ 

which the whole of thb important branch of chemistry derives 

its origin. 

HWorr. About the year 1710 Diesbach, a manufacturer of oolounin 

Berlin, wishing to prepare some lake by precipitating a decoo- 

■ Poggendorf *s Aanden, fii. 320. 



cf cochineal, alum, uh) green vitriol, vfitli [intash, Wrrowi-<I 
e aUcxli for timt purpme from DipiM-l. 'Ilits chemist wm 
le diawovcr^r wl n peculiar animal oil u'liicli i;oos by his name. 
e prepared it from Mihh\ ; mmI itic iilknii u-iih u-liicli he fur- 
nished Dieshacli had Imi-ii employed in the procexM. InKleiul 
of the red preeipilittc which he cxpcile*!. » hwiiitiftd hlue 
powder fell to llir botttim. On mentioning the circumsCmicit 
to DiiiiH'U that chombt ascrihed lh« formation of the powder 
to the aciiitn of his alkali on the alum and vitriol It is not 
unUJcely thai he had cnlcined the potash together with a portion 
of hlood. Ite tliat la it may, he succeeded in di*covcring a 
nethiMl of procuring the blue ]>owdcr at pleasure, nixl it Wiis 
announced as a pigment tn tfae Berlin Miscellanies fur 1710, 
1*hc [>receding history, however) wiw only oommnnicate<l to 
le public by Statd '20 yean nAvr.* 

Thi* fiowder wan called Prnmiian blue ; and the method of 
it remiiiiicfl coriccale*!, be*-aase it liad become u 
ve urticie of commerce, till Dr. Woodwnrd published a 
prucvM ID iJie PbiUMophical Tmnsactions for 1724, which ho 
^Kfad procured, as be informs U'l. from one of liis friends in Ger- 
^^nMniy. 'V\m mctliO<l VW iv follows : Detonate together four 
^■■MwoM of nim and as much lnrl«r, in order to procure an 
^'extMnpofwieonn alkali ; tlien mid four ounwi* of driwl bullock's 
bltNitl; mix tlie inj^redienta well together, imd put them into 
a erocihlc covered with a lid, in which there is a small hole; 
oJcine with a moderate lire till tlie blood cmitH no more smoke 
flaxne capable of hladcrni»f( any white Imly exposed to it ; 
the fire tnwnrd* llie end, »« tlial the wlioh^ nuilter con- 
In tiic crucible s\xa\\ be modertttcly lint sensibly red. In 
ctatc throw tl into four pounds of water, and boil it for 
an hour. Decant off this water, and continue to ]wur on 
Warv till it oome oiT imtipid. Add all ihesc Hijnids togetlicr, 
ami boil tJiem (h>wii to four pounds. Dt^Aolve an ounce of 
nlphale of iron in ImJf a pound of water, and eight ounces of 
■hun in four pounds of boiling water : mix all the three solu- 
taoim (ogetlier while boiling hoL An effervcKcence lakes place, 
nd a powder is precipitated of a green colour. Sejtarate tliis 
Mcipitatc by filtration, and pour muriatic aci<l upon it till it 
DMoom of « beautiful blue ; then vneAi it nntb water and 

• Stohr* EKporiaicnn, Obicrrat. AntnuuIvDrs. ccc niiOMro. Chim. et 
Phj*. p. VHl. 

t nu. fnuu. i»ii. la- 

II. p 




(^i> ■■ Difftfivnt rxpliiiuitioiii were ^ircii of die nature iif tlib 
preci|)itat4^ by (liifcrciit cWmuts. Mr. Brown immeriintely 
rcpvuUici tlie process of WuoHvrard, ascertained limt oU>er 
Hniiiml stthiitidices ■>» f"'Ji "*■>>' ''*' ^<il<''ti toted fur blood: tJuit 
tlie atunt is useful only to dilute tbc colour; »nd tbat tbe blue 
pigment i^ produced by tlie action of the alkidi (altered by 
blood) on tlie iron of tlie vitriol. He ascertained, toes tbat 
priis»iaii blue i-i inaoluhli! in muriatic itcid, and that lli<- ^ccii 
colour is owin^ to a mixture of prussinn blue and oxide of iron, 
and tliat tlie muriutie iicid dcvelopi's tlic blue colour by dissoir- ■ 
I'iiig tbe oxide of Iron.* 

Thenc feet* were of considerable importance ; but they threw 
no Hgbt upon tliv theory of tlie process. An exptiuintion of 
this was first ntu-mpted by Geoffn>y, who bad ascertained that 
any animal l>ody wliiitever might be dulistituted for blood. 
According to hiiOf the blood commuiiieoteH » portion of iiiRam- 
nable matter, or phlogiston, to the alkali, and thiM inHainmalde _ 
matter revives the iron of the ntrlol a»d hriii^ i( tu th< f 
metallic slate. A greater qiuuitity of blood* by increasing the ' 
infliuninablv mutter, Mill enaliic (lie alkali to revive still more 
of the iron, and tbiis toKtrikeablneat onee, intit«adof af^eit.| 
'I'liough this explanation was approved of at the time by the 
best ehemisia, it was Jar from saiisfaelory.} Mactgiier sooB 
after proceeded, by way of experiment, and added a new et«p j 
to tbe facts ascertained by Itrown. 

That celebrated chemist a.'ieertained the following fiiets:] 
I. When an alkali It ad<led to u Holution of iron in an acid, the 
iron '» usually pr«>ci pita ted of a yellow colour, and soluble in 
iicids ; hut if Iron be precipitated from an add by an alkali 
prepiirwi by calcination with blood (wliieh has been called a 
pruminn alkali), it is of a green colour. 2, Acdils (li<«M>lvt> only 
a part of this precipitate, anil leave lK-liin<l an in«oluhle powder 
which is of an intense blue enlour. The green prCHngiitiite 
therefore Is com])osi.Ml «f two <liircrent substaiiees, one of which 
is pniHian blue. JJ. The other is an oxide of iron ; and the 
green colour is owing to the mixture of the two substances. 
4. When heat is applied to tliis pransiaii blue, its blue colour 
is destroyed, an<l it become* exactly similar to common oxi<l« ■ 
of iron. It w cnrnpooed therefore of iron and some other sub- 
stance, which beat has the properly of driving off. 5, If it be 

• Phil. Tnm*. 1794, xixiii. 11. 
t LewU'i Nttiuuui't Chein. p. n. 

i Mem. Pv. ITCA. 



Dilod villi A pure alkiili. il lft«o« its l>l»c colour iJso, niid tit 
bv luutip lime tlit! olkuti ac4|tiin;s Uiv prwjirrty of precipitating 
lot <^iliiiir Hiiliiiioim of iron in aci<t«, or it has hvcome pre- 
thc xaac ii-iih the |inin.'<iaii iilkali. ti. ['ruHsiiiii liliio, 
pfure. is cooipa§ed of iron and something; which » purv 
'alkali call nepwate from ii, something which li»> a ^-iiicr iiffi- 
tuty for alkali than for iron. 7. I)y hoitiii}r u qimiitity of lUkali 
with pniMiun hliii.-, il inuy )>c compli-tciy A>Aliinil«<d wtlhthis 
•ooivUiinKi wlticli may Ik called cvtuitriHff miiltfr, aad ihi-ii po»- 
MMCB ilio propertiva of a nvutnil salt. 8. When iron diswlvcd 
in an acitl is mixi-d with an alkdi saturated with the colouring 
BAttert a double deco<Q)>oaitioti takes pUce: the acid unites 
with tl]4- iUkalt, and die colouring matter with tlic iron, and 
ttrwa pruasiiui bine. 9. The n-uson thui, in tlic voniniou 
aietltod of preparing pnw«ian blue, a quantity of oxidv is pre- 
cipitated, is, thai ihcro i« not n sufficient quantity of colouring 
natter (for the alkali is never saturated witli it) to saturate all 
lli« iron (Ufplac«d by the alkali ; a )>art of it llierefure li tnixi-d 
villi pnoMiaii blue. Muriatic acid di^Dlves thi^ oxi(U>, carries 
it off, and leaves tin' blur in a state of purity. — Such were the 
J emeltLsions which Macqucr drew from his (.'xpiTimont*. 
^k Tbc rinture of the colouring matter, however, wa« still un- 
^Htaova. M»0[uer itup|>iMed it to be plilogisloi]. Acconling 
^Bla bim, proMian blue is notliing eUe Uiaii iron supersaturated 
~ witli phlogiston. This nviTiloM protccU the iron frmn luridtt, 
^^iml prervnta the magnet from acting on it. Heat drives off 
^hlua doae, and leaves tlto prUKsiaii blue in the state of common 
^Klran.* Fran tliia tlieory, wliieti diifered but little from that of 
^VGeoffroy, the alkali saluraled with the colouring matter of 
pnaaiaii blue receiveit tlie name oi f^hx/'uticattd aikaii. Mac- 
qiior luiring obfterved iJiat il did not net on alkaline and earthy 
I M>luttun«, while it precipitated all the metidn, pmpositl it us an 
^ftticellent tf*t for delecting the pteHenee of thcHc laxt bodiiit. 
^B llie sulisequcut vjiperimenls of cheniiAtH threw an uir of 
^Htmpicioii on .Macquer's theory. Bsume ascertuined, that when 
^■pntwiaii blue In ilistllletl, il always yields a portion of animal 
^'Wlrf- a prwluct not very likv'ly to appear if the powder coii- 
tninnl nothing but phlogiston and iroiu Deyeux and i*ar- 
BlMlti»r, Kencuuin, Erxlfbeii, Delius, and Scopoli, submitted 
prHMUUi blue tudiHtiJkitiou, and obtained a i|uuiility of ainmonia. 
|FontAita aacertaiiied that prussian blue detonated witli nitre> 

• 8*0 Micijiwr'* Dictionwy, i. 177. f Bsume'i ChcmMtiy, " COI- 





^**^ '■ l^tulriiuti ubtiiined, by dintiUadon, a littlo acid Uquiil ajid oil. 
un«l a great quantity of azotic gan anA carburettcd hydrogea 
gas. 'I'liese IhcU were still iiiwre iiicoiif iHt«tit, if iiuwiihlt!, with 
Macquer'^ theory. Mon-ojiu advoiuTd :uioili(>r in 177*2; 
namely, thut tlic phlogialicatcd alkali, bi-sidt'S [ilil»;p»tun, con- 
tained a\so an acid wbicli acted the princiiml paxt i» tlie plie- 
nomciui produced.* Sago utSrincil tluit tlie colouring mnltcr 
in pldo<rt,>>tic-iit<.-d alluili u'us pliosplioric acid; but t bis opinion 
WiiA rt-fiitfil by I.avotsicr.f Bergman also announced bis sus- 
picions that it was an acid, hut an unknown one.^ 

Such Wiw the kmtwh^dgc of chemists resppctitig the ttature 
of this colouring inatti'r, when .Scheele all :it once rt-niovc<l the 
veil, and explitined it« propcrliw and coinpuMition, This he 
performed in two dissertations on pniwitHi blue, pnblishcd in 
the Stockholm Trjinsju-lions for I7i^'i and 178-'). J 

He observed that the pnisfian alkidi, after being exposed fur 
some time to the air, lost the property of forming priissian 
blue ; the colouring matter mu.<l then^fore have lel^ it. 

He put a small quantity of it into » large glasit globe, corked 
it up, and kept it some time; but no cluingc H-as prmluced 
either tn the air or the prussian alkali. Something must tlivre* 
fore di'«]>lace the colouring matter when the alkali is exposed 
to the open air, which I* not present in a glas* vessel. Was it 
carbonic acid gas? To ascertain this, lir put « quantity of 
prussiiut ulluJi into a glass globe Riled with that gas, lUid in 24 
hours the alkali was incapable of producing prus>:ian blue. It 
is therefore carbonic acid gas which displaces the colourinff 
matter. He repeate<i iliU experiment with this difference, lliat 
he hung in the globe a bit of [taper which had Ixcn preWously 
dipped into a solution of sulphate of iron, sind on which ho had 
let fidi two drops of an alkaline lixivium in order to precipitate 
the iroti. Tliis paper was taken out in two hours, and became 
covered with a fine blue on inkling a little mnriatie acid. Car- 
bonic acid, then, has the properly of Keparattng (he colouiitig 
matter from alkali witliout decomposing it. 

He found also that other aeiiN produce the s.-uiie effect. 
Hence he concliidetl that the colouring matter might be obtained 
in a separate stjitc. Aecortlingly h« made a great many attempt* 
to jirocure it in that state, and at last liit upon the following 
method : 



* IKgmnoni AcadomiquM, p. 84S, 
t NotM on Sdielbr, § ICS. 

ftlcai. Pw. 1 777, p. 77. 
i Schcclc, ii. 141. 


Mix togptber 10 parts of pntssian blue in pon'drr, 5 ptirte of 
' Uic red oxide of mercwry. and 30 parts of water, and boil the 
LBBXture for some minuEeii in a glass xessei. The blue colour 
f dia^^pcnn, aiMi thv niixiuri; becomes yellowiab green. Pour it 
■pon a filter; uikI uficr all tliv liquid [xirt lias piistted, pour 10 
pcrtH of hut n-ator ihrouj^h thv filter to M-tuh the resiiliiura com* 
pleU-iy. Thf oxidt- of mercury docompiwcs ])rii».siiui blue, 
aepanilem its colouring matter, and forma «'ith it a iwtlt soluble 
Ib vuter. 'Jlie li<(ui<l Uiereforc which has passed through tlie 
filter conLtiiiM tho colouriuf^ matter coinhini^l u'iili mercury, 
llie otbcr component [)srts of the prus^inii blue be iii}( insoluble, 
do not pam through the filter. I'uur this mercurial liqui<t upon 
a parts of clean iron filings quite free from rust. Add at Uie 
fume time ) part of eonconlrated sulphurie acid, and )«hiikc tlie 
mixture. The iron filings are dissolveii, ami the mercury foi^ 
mcrly held in iwbitiun hi predpitatrd in tlie metallic state. The 
caoM of thic sudden change in obvious ; The iron (Ifoxidi/t-H the 
Dwrcory, and ts at the same instant dissolved by tlie sulphuric 
Bcwt, which has a stronger affinity for it than the colouring 
BiBtt4rr hits. There reinaia't in soludou therefore oidy sulphate 
|flf iron and the coIotiriii|; mutter. 

Now (h« cohntriiij; matter being volatile, which tlie sulphate 
of iron is not, it was easy to obtain it apart by distillation. 
Accordingly he distilled tlie mixture in a gentle heot ; the 
colouring matter came over by tlie lime that one-fourth of the 
I liquor bad patsed into ttie receiver. It was mixed, however, 
ilh a Miiall quantity of Hulphuric acid ; from which he sepa- 
I rated it by diKlilliiii^ ii M-CDticI lime over aqu^itify of carbonate 
^ of lime. 'I'bc ■iilplnirtc acid i-ombiiies with the lime and remains 
behind, which the colouring matter cannot do, been use carbonic 
[add biH a Ktronger affinity fur linit? than it has. Thus he obtained 
colouring matter in a state of purity. 
It rcRUiiuetl now to dUcurcr its cnmjionent parts. He former! 
a very pure pruminii blue, which he iliNtilleii, and iiicreaMNl tlie 
fin> till the vessel became red. The smuU quantity of water 
^K which he had put uito the receiver coiitaiuecl n {mrlion of tlie 
^^ blue colouring matter and of ammonm ; and llie air of tlic 
receiver cuiuusted of azote, carbonic acid gas, titid the colouring 
maltcr. He cuncluded from this and other experinientK, that 
thr i-olouring mailer is a compound of lunmonia and oil. Hut 
when he Attcmptcil to verify tlits theory by combining together 

Kinia ami oil, he could not succeed in forming colouring 
r. This obliged him to change his opinion; and ul lu»t 



^"P *■ he concludpd that the colouring matter is u coinpoiiiid uf amm»- 
nk aiid charcoal. He mixed together eqtiai quuntitim of 

r pounded charcoal aud jiotaab, [)iit the tiii.xture into a crucible, 
and kept it n^d-Uot for « quarter of an hour ; he llien ftddeil a I 
Squantity of «ul nmmoiiiitc in small {jii.-ci»>i, wliicli be pUMheil to 
^le bottom of the melted mixture, kept it in the fire for two 
ninuteti til) it bad cea^ied to ^ve out \-spours of ammonia, and 
tiit'n thrt-w it into a quant iry of U'alt'r. 'llie holution po»esaed 
all (hi; |)r<>])(.-rtioM of tlii^ giru.-uiiU) »lk:di. TIhi-'* Mr. Scl 
succeeded in fonoing ibc colouring matter. 
This colouring; mutter was called /»r«Mtr Hcirf by Mo 
in the first volume of the chemical part of the EtKipiupcdit 
Methiflique ; tin nppellnciun wliieli Hoon beaunv gcnunl in 
Great Britain luid Fnincc. 
Of BnihaUtc Tliese esperimenu of Sehcclc were repeated and carried still 
&rther by Uertbollet in 1787 : who applied to the eiplaiialion 
of the composition of the colouring matter the tight which luui 
resulted from bu previous experiments on the component paila 
of ammonia. He ascertained, in the Arst place, tliat the phlo- 
g^isticated alkali is a eumpound nalt, coniaining prii-ii^c acid, the 
alkali, and oxide of iron ; tliat it may be ohtaincd in octah«<ltal 
orystaLf : and lliat when mixed with sulphuric acid, and exposed 
to the light, it I(-Ch ^iU a preeipiiate of prassian blue. His 
iioxt object wiw toatccHaiu the component jxirtK of prussic acid. 
When chh>rine i» poured into prii.wie acid, obtained by Scbeelc's 
prooosa, the lu'id becomes more odorous and more volatile, less 
capable of combining with alkalies, and precipitates urou from 
its solutions, not blue, but ffrtni. He conceived that in tU* 
case it had combined with oxygen, luiquired iiirw propcrtiei, 
and been converted into a new substance, which he called uzj/- 
ftnutic acid. 

From tlicsc experiments, and others similar to tliem, Ber- 
tliollet concluded, tliat prussic acid does not contain ammonia 
ready formed ; but tiiat it is a triple i^imponnd of cairbou, 
hydrogen, and axote, iti proportions wbicJi he wan nut ablv to 
ascerluin. This eoncliDsion wa» verified by Mr. Clouet, who 
found, tliat when ammoiiiacal gas is made to pass tlirotig^i a 
red-hot porcelain tube containing chareoal, a qtuuitity uf pnmie 
acid in fonned.* Tlilt experiment does not succeed unleaa a 
pretty strong heal be applied Ui the Hibe.f 

In tlie year 180(t, a most valuable juiper on pnuwc add and 

Ana. <lc Chim. sL 30. \ Jour, dc I'Etolc Polrtocba. L iii. 






lis conpouxtdM M-as (tithtishcd by M. IVousU* Thougli hv did 

oat •ucfci'd in procuriiij^ tht aeid in a separate statt.-, nor in 

■Krrtuiitiiig it« constituents with rigid accuracy ; lie pDinlnJ 
out a great number of new and im|)(irtant ffti;Ui wliicli were of 
much utility, nJid wbicb fiidlitiitcd ilic Miliartjiiciit invrsti^^ation 
of Gay-Lu«ac. To tbiM liui illuniriuu^ cJu'mUl wv are indebted o*». 
fur nil rai9y])roc«s>tforobuiuiii;;prus»icac!(liiiastat«of}>urity,f 
for an nceuKite dvNcri|iti<>ii of its i>rupertte8 when llius obtained, 
and for a r!iri(l<)<'icrniiiuition of it» composition and coiiHtiiutitin.| 
He »huwed tliat it wm a cumbiitation of hydrogen, with u com- 
pouQt) body, towbicbliegave llie mune of ci/anofft^. This body 
u unitiiigoua to the supporters, and c»|iidilu liko lliom of com- 
bining with difTi-rent Ii<lm>s and convertiug them into acid§. 

Mr. I'oTfetl luul jiroviouMly sliown^ that it wa« capable of •»« pi«»u. 
CDmhiniiifr witli Hulphur, and forming a new add, towbicb tbe 
■auK* of iiffdn>-»»l//Ji"Tifaurc acid has l>cen since given. And 
BrrtboUct had «hou-n tluit it U'lu aUo capable of uniting with 
eklorine, and foraiing an aoi<l which haa got the name of rAittrtt- 
qfotir acui : ihuut^h die real n.itun.^ of this acid was lint A»cer- 
bdt»«l by Ciay-Lu>viHc.l| iiiill vonsiiliTiible olMcurity hung 
about tlie Hall origiimlly formed by Mucqiier, and called by 
pUoffittirtttitt i>uta*h. It wiw iifterwnrds denominated 
ij^ pvtush, an<l ttfl nature and properties were succes> 
invratt);ated by different chemiMs. But the nature of 
the pn-cipilates whidi it forma with metallic sallA remained 
ttncjuunined till IleizeliuH puhlixhed a nvt of experiments on 
ike ubject in the year 1819,11 wluch Bellied several points 
vilL great accumcy ; tliouf^b there are still some others which 
acbnit at tnore llnin one explaiuitton. 

Sdidv aildilional fi>cli« liave been more lately added to thin 
btvmiting bmnch of ebeinicul wience by Wiibler, (iay-Lii>MtC, 
Lictrig, and Mr. Eilmund Djivy. I iiiiaU endeavour to lay iis 
daar a view as pouihlc of nl) the dilTerent brundica of tlib di& 
Aoolt hut interesting Hubjcct in the following Bcctiotuu 


I ltav« gireo an account of the method of preparing cyamnien, 
and denoribed tu propertie* in the fir»l volume of tliis work 

(p. 3og). 

• Am. de dihiv. Ix. I&S. t H'iJ' Ixxxiii. SIA. ( Ibid. scv. 130. 
{ PhB. Mar. skxvL 196. ~ y Ann. de Chim. xcr. 130. 
1 Ko«^ VMenii. Acad. Uauill. 1819, p. 24^; and Ano. dc Chim. ct du 
Pliy».«T. 1*4. 


"^'- It is a compouad of two volumes of carbon VEpoar and one 
volume of azotic gas united together, and condensed into one 
volume. Hence we obtaio its specific gravity, by adding 
together twice the specific gravity of carbon vapour, and the 
specific gravity of azotic gas. 
OMnpamco. Sp. gr. of carbon vapour s= 0-4166 X 2 = 0-8333 

Sp. gr. of azotic gas ... = 0-9722 

1-80&5 = 

specific gravity of cyanogen gas. Volumes of carbon and azotic 
gas bearing the same relation to each other that atoms do, it is 
obvious that cyanogen is a compound of 

2 atoms carbon . . = l-S 
I atom azote . . 1-75 

So that its atomic weight is 3-25. We may obtain the specific 
gravity of the gas, by multiplying its atomic weight by 0-6656. 
For 3-25 X 0-5555 =: 1-8055 the same as before. Now Gay- 
Lussac found by experiment 1-6064 which comes within len 
than s^ijth part of the theoretic number. The two, therefore, 
in this case may be considered as identical. 

Cyanogen has the property of combining with a great variety 
of bases, and of forming a set of saline compounds exceedingly 
analogous to the chlorides, and which have received the name 
of cyanodiiks. The greater number of these compounds pos- 
sessing the properties of salts, I shall reserve the desctiptioa 
of tbera till I come to the saltSy which will occupy our attendoa 
in a subsequent part of this volume. But there are one or two 
compounds of a more complicated nature, which may be noticed 
^^'S^' 1. When a current of cyanogen gas b passed through an 
aqueous solution of ammonia, no fewer than four different com- 
pounds are formed. 1. Prustiate oi Amiaom&, OT hydrocyanaU 
qfammcnia, as it is also called. 2. Tlie dark brown substance 
described in the first volume of thb work (p. 211), as precipi- 
tated when a solution of cyanogen in alcohol is set aade. 3. 
Oxalate of ammonia. 4. A peculiar crystallizable body, resem- 
bling cyanodide of ammonia, but certainlya different substance.* 
It is probable that the oxalic acid and hydrocyanic acid are pn^ 
duced by the mutual action of the water and cyanogen on each 

• WiJhIer, Kong. Velena. Acad. HanUI. 1824, p. 32a 



For four atonu of c-j-aiiofi^t'ii Hint tlirw utoms of walrr, Otm ri. 

Di^lit, by muluiilly dn'ompositig cocli otbt-r, produoe otic utom 

oxalic aeid «ud tlirtf atoais of hydrocyuoic acid. 

Oij. Hfd. AiDCc cub. 

8 irat«r contain 3 + 9 

4 eyuwgcii contain -f + "^ + 8 

3 + 3 + 4 + 8 

1 oxidic arid 3 + + + 2 

3 hydrocyuiiic acid + 3+3 + 6 

3 + 3 + 3 + 8 

Tbcre Is a aurplus of 1 atom of azote, wbtcli most either enter 
•i m ooutituviit into the dark browa matter or into llie ctysial- 
End Bubotancc. This cry^Iallized siilutance may he obtained 
pore by decomjMMing cjanodidc of lead by viiuHlic ammotiiui or 
cyanodide of sUver by sal aroinoniue. It liaa a white oolour, 
oyMallizefi in neetllen, niiil cIImoIvcs easily !n w»(er and in 
akf^L lu solution u neutral, imd it in not |>rvci|iittited by 
lead or kilver, or by any of the other tnelallic iult«. M'hea 
d^esled in cnustii- potash no ammonia bt given ouL It Neenw 
loconiain water of eryituIHiation. When heated to redncM 
villt [>otawJuinabundiuireofc)-anodidcor[>otn!wtiujnisobtaitie(L 

3. If itleohol bt- utunited uidi cyiinogcn ^;u», and then with ofi 
MlpburvUisl hydrojfcn gas, it atsumea a dark yellow colour, and 1^^''''°'" ' 
Mwn aftrr lunall red crystals are deposited. Tliey have a tine 
•cariet colour, oonsiderable lustre, and are opaque. 1'hey ure 
■carcely boluhle in cold water; but thvy di»olve in hot water, 
fntni which, howeier, tlicy nic ajraiii lUjio^'iti-il as the liquid couls. 
This sulwUuK'e U hut liltle «ulublc in ideuliol. When geiitly 
healed il partlyoublimesunaltcTed, but the greatest port becomes 
hlack, while much sulphuretted ammonia is disent^iit^d, imd a 
bhck coaly mutler remains. When passed through )ii)toxidt-of 
Ki)>p4-r a great deal of ammonia b disengaged, whidi (Im-k not 
render lime watermuddy, and Uiereforecon tains no curhoriicaciA 
Wiililer, to whaui we art- indrbcrd fur all thuHe facUi, useertjiined 
by digostiuK it in aqua rvgta tlutt it eunt»in<-<l i>3 per cent, of 
wilphur. I tliiiik it not improhabic tJuit th<-M' cryHtaht consist of 
bydrosulphocyiinic add. Thix aci<i contains &4"£i per cent, of 
lulphiir, which iippnKiche>i pretty near the estimate of Wiihler. 
Huwever, the action of It on the alkalies docs not coirespoud 
with thin notion of its nature. 



ttt^.L These red crystaU dissolve ui sulphuric acid, ^ivit 

liquid a yellow colour, and they are ai^ain pipcipilatod when the 
acid n diliiml nith wat^r. Tint alkaline t^urlioiiaCeit di»»oIve ^ 
them witti tlie itwi»UiiiL'u ofhvjitiniid the itolutioii Ua mixture of H 
sulphuretted pl>l:M^illm and isiiIjdiocyunixUde of potH'M'ium. 
They are very tioliiblv in caustic potasli. Thi^ sultitiun is yel- 
low. When the crystals are mixed with a solution of acetate of 
K-iul the acetic acid Is immeiliately disen^piged and a fine oraii^ 
pix-cipiUili- TaU-s xiniilitr in appc-annice to chroinale of loud. I'lio , 
colour rVRinins after the powdi-r U dried, provi^led only a wry ^m 
^iitlc hout b(! applied. But if it be be»ted, or even hoileil in ^ 
water, it is converted into nnlphuret of lav^d. If tliv orange 
precipilate be di|rrs(ed in caustic potJifh siiljihuret of lead separ- 
fitei*, and we obtain a solution of cyonodidc of potassium, and 
aulphocyanudide of potassium. By analyzing tlilH orange 
pouflcr it wit'* found to conlain in one experiment 64 and in 
aiiutlicr 64-5 percent, of lead. Now siilpliovyanodidc of Ivttd 
[ js a componiHl of 

SulpliocyuiK^sn . 7'95 or 35-81 

Lead . . . 16 . 64- ID 




This approaches so closely to Wiihler's analysis as to render it 
probable that the orange precipitate is merely a sulphnryan<»- 
dide of lead. However, tliis conclti-tion U opposed by the 
different etTeot which »ulphuc)'imate of poUt^h pnKluces upon 
till' NaltH of lead.* 

0. W hen a current of cyunogcn ^as is pusM-d thronj^li a sola- 1 
' don of perMulphiurct of potassium much sulphur is prccipibttcd, < 
and a (jiuintity of the brown charry matter aliso makes its 
a]>pcarance, and when the solution in concentrated crystals of ^ 
sulphooyanodide ofpotassituu are obtained. If this sulpluH^J 
cyaiiodide be heated In redness in an nininiphere of cyano^iMi ^^ 
giu, n ^kiid deal of sulphur ix driven off, luxl the latuvt bi'ciunof 
Bt first black from decomposed cyanogen. Itntthedsrknessof tlie 
colour Hpecdily iliminishen, and the substance becomes at Inst a 
coloiirlew fii«ed bmiy, which on cooling becomes a white nit, 
which proves on examination to he snlpliocyaiuKlide of potQ*- 

When a current of cyanogen gns ij* poxsed tliroiigli n solution 
of protosulphuret of poUtSstnm, no sulphiu- is precipitated, and 
we obtain a mixture of cyanodido of potassium and stilphocy- 
• Kong. Vctmu*. Acad. Uaiull. 11«+, |i, 3BB. f IWd. p. 331. 


if at potBmiitm. Tlic reason is obviously becaiiitc the 
■Ipbiir )in>!)ciit ifl only capable of converting oii(--hiilf uf the 
num into sulphocyaiKxIiilc. Wlicn cyiinogen gas is 
(t itirougli hy<)ro]>ui|tiiuTvt of potash iho above de«)cribeil 
(Tj-stalii are obLiiiicd, ii.'ii()crin^ it probable that hydrogen 
I ono of the consttluvntii of this ted matter.* 




Tbo first person wlio obtained tltUnci<l in »M-purate stale waa 
Scbeele. He obtained il by tlie pruci-tut described in page 213 
«f thia volume. Tlie foUiiKing is the process recommended by Jl^fuiJJi- 
Gay-l,U)u«c : Put into a smuU tubulated retort a mixture of 
pruNsiiiU' (rf raereur)'f and muriatic aoid. The quantity of add 
ftluHiliI \k less than would be re(|ii!sile to decompoRC tJie pTiL<»> 
■ttle of mercury completely. 'I'n tlie b^ak of the retort fit s 
flam tulie at>oul Q feet in Iwifrth luid ubout 7^, tits of un inch 
vide. Kill the fint third of thiH tube with fragments of maible 
in unler to rctnin any muriatic uetd tluit mi^ht nnnc over (but 
ani iJiMuld be taken to prevent ibtH lut much iw possible). The 
nn^tMler uf tho tube ts to be filled with chlori<le of cidcium to 
retaia the water. To the extremity of this tube adapt a unall 
noeiver and surrotmil it with ice, or still better, with a mixture 
tfmow and nhIi. Apply a modenttc beat to the retort. The 
hydrocyanic add poues over and condenses at first on die 
ilv. Kul it i« vwiy, by Rpplyin)>; a ^-ntle heat, to drive it 
the tube, und into the ruc«-ivvr.t 
Tlie process recommended by Gautier is however easier and <« omxio, 
lenper. It in ns follows : Fuse the yellow wilt well known 
the name ni fvmujiiuMS //riutitite o/fx/laxh, or frcqutailly 
called Himpty prv**iale of potatJi, in it vt-tiscl to which utuio- 
rira) air has not ucn'ss. This suit is eonsidvrcd at present 
double cyanodide of potiissiiun and iron. By this procext 
ide of iron is decomposed nnd an inflammable gaa 
over. The iron I« converted into a carburet, which may 
M'piimt4'<l by diswlvin^ tlie fused salt in water. If we evan 
the filtered •nlntion wo obinin a white salt, dieting uUhed 
the natne of cyanodide of putnssium. And thiit it reidly 

Kong. VetcM. Aciul. IIiukIL 1894, p. S3S. 

Tlnk mIi il obtaiiicil bj bu>Liii(; rcil oxide of mcrcur)- nnd pniMJan blua 
r. umI enfiontticc die Bulutiun formed till it cryttaltiic*. The cryw> 
eoiMlilMs prmimle ^ Rtrrvry, or i-jronodMlr «J' mtrtufy w it is now 

pa. de CUn. p. 144. 


or St. 



contains potaixiiim h obvious from thiM : If you put a plate 
c'ljpjKT into its ^olllti«n poUisHium is iinin«Iiiiti?ly precipitated; 
but ill (wiiscqueiice of tUe presence of water in tlie liquid U a 
speedily converted into potash with a very evident effrn-e»- 
oeooe. We see from lliis that copper is capable of ilirowing 
down potaaaitun from iti« combinalions.* Put the cyanodide uf 
poUui-sium tliUM obtained into « flask or retort ftliglitly moistened 
with water, and iidd t« it muHuticacidbyalittit; at a time. The 
bydrocyiniic add is disengaged hi a guM-ouH slate. Cuit«e it (a 
pass through a tube filled with fragments of dry chloride of 
calcium, and receive it into a small fiask kept as cool as po»- 
uble by being Korruiindeil by a mixture of enow slid salt. 
Hero the acid condenses -inlo a liquid. 

As hydroc)'aiiic aeid is very much employed in medicine, and 
as itt cHicac)' is very much cuniicctcd with its strengtl), it cnraet 
to be nn object of considemlile importance to be in puK«e«nan 
of a method by wliich it can be easily jtrepared by a common ^ 
apothecary in a state exactly tlie Rame in point of strength at ^| 
all times. The following process, tug^^ested by Mr. Clarke, 
apothecary to llie C>l.'ii<gow IiilinnATy, powesses tliis requisite, i 
lo 100 drachms of water dissolve S^dmchms of cyanocUde of poC-H 
Bssium,! and udd to the solution 1 8'] drachms of cryitlallixed mr- i 
taric acid ])reviously dissolved in 20 drachms ol U'atcr. A double 
decom))osition Likes place. Bitartrate of potash falls dotvn, and 
about 120 drachm.t uf uTiter will remain, holding in solution 0| 
drachms of hydrocyanic acid, or '2'Kt ])er cent, of the solution is 
hydrocyanic acid. Ofacic) of tliU strength 8 drops may be given i 
thrioi- a (hty in agla» of u-ater. The only impurity in iheucidj 
when thus prepared is a small quantity of cream of t<rr[ur, wlitchf | 
in a modiad point of view, is of no consequence whiUi'ver. 

Hydrocyanic acid thus prepared is a colourless liquid, haviii^fl 
s Htrong smell similar to that of peach blossoms. Its taste 
sharp, and at first appears cooling, but it soon excites a bum- ' 
ing sensation in tlie mouth, and it is very astlienie, and indeed 
a vindent poison. .\[ the temperatureof 44° j its specific gm- 
vily is y-7038, at the temperature of G4°^ 'n» sj>ecilic gravity 
is 0-6069. It boils ut tlie temperature of 79-7'', and coiigvak 
about the temperature of 5". The cold wliich it produces when 
allowed to evaporate in the open air, even at the temjicrntiire , 
of 68°, is sufficient to congeal it. Its a]>pearance when froxenl 

* Thi> (Uf;g«it« an 08*ier metliailur|iT[)curlng[K>tawuinihMibuhiiberto 
boea pnuriiM'il. 

t Tliu mlt is ciuily prciiureil by cbv jtrocws given in thii srctiw. 


[ tomowhat similnr to tluit of ciystallizod nitrat« «f nmmonia. 
Khva WatiNl to tho t4^in|>0Taturp of 80° itasstimi'K tlic^;uM>oua 
niKl tlw i>>[ivcilic' griirity of its vapouT, as dctormiiii-cl by 
Gsy-I.uiH«cuO'i>476. Bein^c a compound of I volume liydro- 
f(eu uid 1 volume cyanogen uiiile<i ti^elli<-r w'iliiout any altora- 
lim III volume, it is obi-ious tliat t)ie true specific gravity mtist 
be tbv laeun of tlial »f cyano^ii gas aiid byilrogon gas. 
Sp. gr. uf cywiogcu gM . . i-6f)55 

of hydrogea gas . . 0*0<>iJ-i 



1 1-8749 


Mean 0-9375 
Tltm givoft usi 0-9375 for tfa« specific gravity of tliu* giis. It ia 
Dtir of ihoHc gaai-» wliottc optrcilic gravity u Mbuiiiiecl by mul- 
tiplying its atomic wciffbt by li'2777. Xow we shall see 
imiDrdiately tliat its atomic weight is 3-375 and 3-375 X 0-2777 
= 0-B375, tbe same as before. This calculate<l !i[M-cilic gravity 
tmnrs within I pfr cent, of tlie expcrim<-ntal r«<tull. 

When ihv riipour of ibis acid ia mixed witb oxygen giut, and 
an electric cpork pniwrd tlirough it, a dvtonution tukvs place. 
~or complt^K* comhiiAlion, 1 vulumu of tliv vapour rctjuirfs 1-25 

oxygen- The produi-ts arc I curbontc acid mixed with 0-5 
■Me. 1 of the oxygen wont to tlic formutioD of carbonic ncid. 
The rfroaining 0-25 of oxygen must liave combined with hydro- 
gm, tuui th« quantity of hydrogen witli which tlicy combined 
nu*l luive bit'ii 0-5 Hence it follows lluit hydrocyanic acid oaimioJUiio. 
nutt consist in bulk of I v<»liime of carbon vapour, J volume of 
ltg|e« and ^ rolumc of hydrogen ; or, doubling the volumes, of 
Q volumes cnrboii vapour, 
1 volume azotic gan, 
1 Tolume hydrogen, 
eotuIeiKMtt into two voIutnv». Hut '2 rolumet! carbon vapour 
4- 1 vuluinc i»otic gas condensed into I volume, coiiMiituie 

aoof^. It is tlivrefoTC o(>vious that hydrocyanic acid is a 
naipound of 1 volume of cyanogen and I volume of hydrogen 
gMCS united together without any allerution of volume wbat> 


Aniiydrous hydrocyanic ncid tin<lergoes spontaneous decom- 
{MMtJoti even in ilry vessels, and though kept in a dark place, 
^imetimes it is decompiled in u few hours, while at oUier tiinm 
It may l>e kept for a couple of weeks witliout ulteration. The 
colour becomes first reddisli brown : this colour deepens, aitd a 




Arti"n o( 


-Of hat. 


quantity of lh« brown cbnrry mattor, already repeatedly alluded 
to, is tlrpowted, with a umi-ll of ummoniA. In short, die add 
i» ^milHally converted into cyniiodide of aminoiiia and the 
charry mutter.* This uvid when diluteil with water may be 
preserved any length of time provided it he kept from theiicti'Hi 
of the light. The hest u-ay U to put it. into a phial covercil on 
the oiibtidc with a ciuttiii^ of blade painL If wc expooe it taj 
the liffht, even in a eloso vesHel, it underf^cs coni])Ict« <ieo(Hn- 
posilion in a very short time. 

When sulphur is healed in hydrttc)-anic add giw, it nbsorb* 
the ffv<, and if we sritiiralc it with thin gas we obtain a yelloV 
coloured tolid body haviiif{ ii irystjilliiie texture, which disBolves 
ui water, does imt precipitate the salts of leiul, and fornix with 
the iKLses a peculiar genus of salts not hitherto invo^lipited. 
Pho*ph<iru« may he sublimed in hyilrocyauic acid gas witliouft 
uiiderfjoiiigaiiy nlteratiou. 

When thin acid giw i* p>ui)ted throiigli red-hot iron It und«w 
goes complete decompmition, charcoal beitifj deposited on the 
iron and a gas evolved, which is a mixture of equal volumes nl 
hydrogen and aiotic gas. When potawium is hootcil in tlii« 
gas it absorbs the cynnogen and leaves a quantity of bydrogen 
equal to half the volume of the byilrocyniitc acid employed. 
The cyanodide of potash dissolveM in water, and yiehU when 
evaporated a white salt ejcactly similar to that oblaine<l b; 
fusing t)ie common yellow prussliite of potash. 

'Hie alkalies when placed in contact with hydrocyanic del 
oemsifut a double decomposition. The hydrogen of (he ucid 
uniting witli the oxygen of the alknli conslituteN water, wbittf 
tile metidlic bases of the alkidi uniting to the e^'anogvn forma n 
cyanodide of potassium or sodium. When these cyanodidcs 
are exposed to tlie air {especially when in solution) tlic potas- 
«ium or sodium is speedily oxidii[e<l at tht> expense of the air, 
ind llie cyanodide is in consequence decomposed. The car- 
bUnic ncid of the atinos])her<- gritiliudly unites to the alkali tliU9 
formed, and the tij/tinicj/nHie acid or rffnttagm is disengaged. 
These cyanodides may be preserved much longer in a solid 
Btute. I have kept the cyanoitide nf potfis^itim fur a consider- 






' * It would appear ftwn the dbiwatioiu tX M. KuhlmnTi, tho* 
hj'drorjanlc ncid u mixnl with maiWic add ■bundancc of cryati* oC 
Binmonjnc arc nlmoit immodiatcl/ Ibnnnl. Ann. tic Cbim. ct dc I1i}i. xl> 
441. It is pouiblcthnt theipccd}' dccompoHlion of h)'<lracyniiic arid maj 
be pBTtly owing to the procnce of »omc niiirtaliv acid in it, when obtaineii 
lif Oiy-Liunc's pn>c»a. 





>lblv time iii a pbia) witliout any t«ti(Jency to decomjioiiilioii 
bring (K-rceivptL 
^H 'I^K (Icuto.xuii* «f tnnD^ifHC iib«orb4 completely tb« rn|iour 
^Hof liytJtiK-yiuiic itctd ui u ft-w Iiouth. Water M fonnvili t>iit 
^Bcyuiiogcn U not uvokcsl. 

^B U'licit nti uxide of mercury ia heated in liydracyaiiic acid 
npoor a riob^it iictiuii takeH [ilncc, and ho iducIi lieat is evolved 
■a to destroy lli*^ compotmd funnitd. When Uie ex|H>rim('iit is 
■wle wtibout tliv npjiltiiitioit of Lt-stt, tlic vapour it iitiM)rl>i-<l by 
I tba oxide. When the oxide thus sutomtett with vapour of 
hvdroevaittc tcitl i*i lieateit, water m di)>eiif;n)red, aiid there 
I renuuiis tlu- Muli«tani-c* fonnerlv known liy ihv H»RH^ of pritasi- 
i ate uf mercury. It is obvious from tliU that a double tteoom- 
podtinn take« phicc, water in formed and cyimmlide of mercuiy, 
Hydruvyiinic acid hi one of the most virulent poisons knon'n. 
Some yrius a^ru, r cbcmiitt, while engaged in preparing it, let A 
lew dro|t« &iU upon lus arm. It Rpecdily evaporated, yet the 
urarCuiiate roan fell a victim to tlie applicaticui in tin- coume of 
two iioiir«." When a single drop of it is nppliod to llie eye of 
a common sized dog or a cat vioU-nt convnlMons are produced, 
wldeh speedily terminate in deutli. It has beeit long kntfwn 
tku aminonia constitutes an antidote to tliis poison by euunt<T- 
■ctinf; itH effects. Dut from tlie cjiperimentit of M. 8iineon,f 
nnfinm*tl by those of MM. PersoK and NorraCt ita])pesrH that 
ilurtneconittiluteaamorecertainandcompleleaDtidote. Being 
into tlie throat of the poUoned animal it »|>ee(lily relieved 
symptoms, and tlie aniiiuil, after an interval of some hours, 
recovers iM health. Even in one ca«e where the poison 
been allowed to eicrt its action till the animal w»s at tlie 
atnt of dentil, the res|>iration havinir iHrcii stop[ie<l for '25 
(U, the applicalion of chlorine restored uniroutioti, and tlio 
.tounal recovered 

Ilydroeyuriic acid when miieb ilihited with water is nlso a 

poison when culm in isle red in suHieient quantity, ilut when 

iren In umall quantities it lias been found a raluable medicine 

varioas di*e>»e«, »n<l in none <Ioit« ilH adminutralion appear 

be more benvfiviid than in dyspetxua. 1 have found iliat 

water holding in solution one per cent, of this acid constitutes 

a Mffi<neiil strength. Of this, as much as a scruple or evcti 

balf u dntchm may be given twice a day. l)ut I have found 

that about 8 ttrops of it aditunistered iii a ghu>» of wuter const)' 

* BeneUiMi Tniti J« Cliiinie, ii. 91 1. 

t Ana. da Chiiu. ct dc Phja. xU 3M. ( llnd- xliii. 384. 

I VI. 


of nwrcttry. 

Itiilmn mM I 






"^t- tntet « suflident doM. When giv«n in Inigtr doMt it <\mi- 
niitheA the velocity of the pulse to a very rrmarkBblc di.'p^'*'. 
Oti one occssioii I reduced (lie puUc of an individunJ to '23 
bcati per minule. ITpoii u-itbdrawing the ni4-didiic tJic pulse 
gradiially rt-sumos il» niitiiral' velocity. If the use of the medi- 
cine i>i- jx'nistcil in after tlic piiW iiu-t been thus dimiiUAbed, 
tiw patient is thrown into a state of letluirfry' similar to that w 
well ilescriljed by Shakespeare in tlie tr.i)j<-*Iy «f Koro«0 mbA 
Juliet. A lethargy of thin kind, into which a liuiy wu tltrowa 
in Glasgow, continued almut HO hours, and she rcoovered Rg&iii 
without any luul con^equeiice.-i wLitever followiJig. 1 moiition 
these liiet^ to show with what caulioii «o powerful a medicine 
should Ik? prescribed. 

Lassaigiie lia.4 proposed the following method of detecting 
hydrocyanic acid after d(-ath in tlie stomachs of thoiie wbo Iut* 
been poisoned by that baneful drujj : Tlie stomach is to be cut 
in pieceH and mixed (togetlier witli its cnntt-nU) wiili a little 
water. I'his mixture '» to be distilled by a gentle beat till 
about one-oight)i part of the water has pa«*ed over into tlte 
receiver. To the dLiliiled liquid add a drop of i-uiolic ]>ula»h, 
and iinmediatfily after a very small quantity of the solution 
of liulpluitc of o>pp<<r. A Hnmll quantity of matter will be dit- 
enipiged by the action of tlio alkali on the copper solutioo. 
Then add one or two drops of muriatic add. If no hydrocy-fl 
anic acid be present the whole cupreous precipitate mil be di». ' 
solved, and the liquid becomi- tnniK|>arent. Hut if any bydro- 
cjranate of ci>|iper be present it will n-miiin undiKSolved Mid of J 
a whit« colour. By thiN method jQi^no''* P*>''^ "'^ ''"^ liquid of ^ 
hydrocyanic add may be detected. There is, however, a source 
of nmbi^fuity. The same white precipitate will remain if ibe 
liquid should contain hydriodic aci<]. Sulphate of iron when 
substituted for Bulpliate of copper will detect tbJoo*'' "^ 
the weight of (he liquid of hydrocyanic aciil, but it has the 
advantage of being chanictcrittic in consequeiici; of the forma- 
tion of pmiwian blue' If the qiuuitity of hydrocyanic aeiifl 
pre»cnt be very small tlie hydrocyanate of copper is ledissolvett 
in tlie course of a few hours. 

The same difficulty occurs in determining whether Iiydro- 
oyaiiie acid iinit4.>s with Ixise-t, as wa« mentioned before respect- 
ing muriatic acid. Yet I tliink that the phenomena leave 
little doubt that no such class of salts as hifdructfaHaUa exUt. 

* Am. de Cbim. ut dc I'hy*. sxviL SODi 


Sut tiiat whenever tltia acid cotnee in coiibtct witli nn oxide a 
snblr dreompoAition takM place, water hein^ formed while the 
rcn utid the metallic l)«xe uniting constitute a cyanodide. 



I bnro hren ituluced to give this name to the acid first dis- iniiorr- 
corered nnd dewribed by M. Wi>hlor, under the name of 
ryanic ncuL,* \x\ const-<juence uf ihi- Mibsequent discovery t)y 
SertilUs of uiiothiT C4>m[>i>uiid of cyaim^rcn ami oxygen, which 
ooatsins twice u niicli oxygfii m Wohlcr's ucid.f To lliis lost 
aeld we most, oeconliiig to the rules of nomenclature, apply 
^tfce Bune cyanic acid. 

The exbtence of cffomnu acid waa first suspected by Vau- 

[>Un. He observed that when water impregnated with cyim- 

fn waa not aside it underwent spontanoous de com portion, 

converteil into carbonic acid, Iiydroiyanic aiid, charry 

cr, lunmonia, and a particular acid which lie propoM'd to 

jntpii»h by the name of ci/anir aritt.l 

V'uhler found tliai wh4^n a current of eyanoKen pis was 

into burytcs water containing undissolved crystals of 

jrate of barytes, the liquid ntsumcd a brown colour, and 

J fiinrrj' uiatlcr was deposited while the bury to* diwolvtMl. After 

ithe proc<*'n was over, he pa>«ed a current of carbonic acid gas 

[ihroagb the liqiud to decompose any tiydrocj'anatc of barytes 

llkiit it might contain. It was then boiled to drive off tJie 

'Iiydrocyanic acid and concentrated after filtration. A while 

■ilt wai obtained in silky needles, which was cyanitt ofbanfltx.^ 

In bis pa]>er on this subject, he examined the projierties of this 

tyBoitc and of sevenil others which he obtained ; but be did 

apt tnOMCtl In procuring the ci/ttnoug arid or lu aiialyxiiig it 

But finding that water and his acid by mutual <leeomp(Kittion 

i were converted into carbonic acid and ammonia, he concluded 

that his acid was a compound of 

I atom cyanogen, 
1 atom orygeik 

t eynnouft acid contains 
waU'f contain* 

Ttrtid atoms 

Oil. Cmt. Amu. Ht&r. 

I + 2 + i 

3+0+0 + 3 

4+2+1 + 3 

1*« Aonnlcn. UkL Mk 
f XfM. dc Cbin. et de Vhyt. ixxvui. 379- 
f Oilbm's Anaklen, hii. »7. 

t Ituil.n.ll3ixxii.l32. 





2 carHonic acul oonlaiiu 
1 umntuiiiit coulains . 

Cay. CmH. 
+ + 

A«MK Hjil. 

I + 3 

4+2+1 + 3 

It is evidflnt from tliis that ono atom of cyanous acid and three 
uUimii of wutcr may be converted into an iuiegmnt paiticle of 
bicarbonate of ammonia. 

WiilUer found afterwards that the easiest method of pro* 
curing cyanite of potath was to reduce anhydrous ferroprussiatc 
of pota.vii to a fine pou-dcr, aud mix it intimately witlt atwut 
its own weight of blnclc oxide of iiiangaoese. 'I'liis mixture it 
to he heated in u Kii\'er micible to incipient ig;mtion.* The 
matter which has been tiius hcuted b* to he boiled in idcobol of 
the spcciGc ^vity 0*ti:)2. 'llic alcoholic Holulion us it cools 
depositfs cyaiiitv of put<wh iit smiiU sciUm, simiJar iit appear- 
ance to cliluriite of pota^li.f He now tuibjectrd tJie acid to 
analysts, und confirmed his former opinion of its constitution. 
"Wbhler's attempts to obtain tJiis acid in a separate state were 
unsuccessfiil ; but Liebig pointed out a process by which it 
might be procured nearly pure, and so that its characters could 
be recogiiisvd4 Hi.t unidyHt* at lirst ilitfered from that of 
M'iihler, but he aflorwurds siilisticd himself tlutl \V<ihler'« 
dcterminutiuii was correct. 

Cyanous acid may be ohtuined by the fallowing proceM : 
Mix together solutionsof cyanite of potash and nitrate of silver. 
Tlic cyanite of silver precipitates in the state of a white powder, 
whicli is nearly insoluble in water. Suspend tills cyanite in 
water, and pass through the liquid a current of sulphuretted 
hydrogen gas, taking care not to add enough to decompose thfl 
whole cyoDitc of silver employed. The silver b tlirovn down 
in the state of sulphuret, and the cyaiious acid dissolves iu the 
water. Let the sulphuret of tulvcr and uudecomposed cj'auita 
subside, and then decant off the clear liquid, which eomtitutes 
ail aqueoiiK solution of cyanous acid. ThU liquid lias a »our 
tuste, aiid reddens vegetable blues. It-* Kmell in coinjiared by 
Wiililer to that of aeelic acid. When left in contact with 
water it undergoes Mpont^tiieous decompnxition in a few hours, 
being converted into carbonate of animonia.§ It combines 

* Too grcsC a heat dcitroyt the acid. 

t Ann. dcChim.cCdcPhj'i.m-iL IM; and Gilbert'* Annalcn.lxxlB. 1&7. 

t AiMi- de. Chini. et dc Phyn. xxiiit- £07. 

^ Liebig, Ann. d« Chim. et dc PhyK. xxxUi. SOB. 



mth thu lUA'ffTcnt biueflt and neutralizes thetn, cQmtatauag owvl 

^fmaitUj MOW ot wbioh bare be«n exomiiiett, anil will In 1_ 

doHribed in a rabsequent part of this work. 

7u (Ivtermiac tli« atomic weiglir. uf tltt^ add, Wiildpr aiu^ 
lyud cjnuiite of jtotmh oihI cyanite of iiilr^r," He found tlietn 
conposcd M foUowB ; 

1. Cynnile *^i>i4ash. 
Cyaiioua ucii] . . . 4'353 

PotB»li .... 6 

CyanouH r)cUl . . . 4*348 

OJide of silver . . . 14'75 
Tke mean of the two onmbem attached to cyanoiu acid is 4-35, 
vlneb tlierefore is the atomic weif^ht of this acid as derived 
froD the experimentN of W'iililer. To dcterniiiie the ooiitpo- 
ridon of tiii« add he decomposed a gti-eii weight uf cyunit^i of 
dm- by means of nuriiUic acid, which convertn Ui« carbon in 
tbr acid into cnrbonic ucid gan. The volume of vurboiiic acid 
beiii^ meiwun-il ypivr Kim thp wpi^lit of carliooi whicl) the 
rid in the 8ult coiitiitnt-d. Cysuiof^-u Wing a coinpotiiul of 
1*5 by weight of carbon and 1-76 of asiote, it vna easy to infer 
weight of azote in the acid. AVIiut wan wanted to make 
I tbe whole weight of tlie add was considered ax oxygen. In 
. wmy he determined Uic constitucntii of cyanous add to be 




Aiote . 


Oxygen . . 



is obriously equivalent to 

^ atonu cariwn . 



1 atom oxygen 


tbat, aocording to thb aiuityKJ*, die true atomic weight of 
loui Rcid is 4*35, and it is a compound of 1 atom cyanogen 
tad 1 atom oxygen. 


^B Tlik acid w» discovered by Scntlliu in 1 829. He obtdned Ill*>«^ 
H|^v dissolving a substance, which lio called perelUonde qf 
^^^B * Ana. (to Chkn. tt ik Phf*. xxvii. 196. 





*^'"i' *- ^UNMCtpni, and wliich will be described in a subsequent section, 
in hot M-Bter, and boiling tlie solution for some time. By tits 
uctiou of the hot water llie iicrchloride is converttil into mtiriu- 
tic acid nnd cyanic lurid. By cvRporatin); llio liquid the 
murialiv iicid li driven off, and the cyanic acid is deposited in 
cry still)!.* 

PmpnttM, Cyanic iicid llius obtained is a white itolid which cryslalliies 
in brilliant tninnjuiriMit rhombs. When beuled it sublimes, 
and is then dt-positt-d in fine n<H'(llcs. It has but little taste, 
yet it reddens vegetable blue«. It is but little soluble in coldfl 
water; but hot water is a better solvent of it. lis spcolic 
g^vity is rather less than rS47. For it floats in concentrated 
ftiilphuric acid, but falls down when that ocid is slightly diluted 
with wiiter. It requires for volatilization a heat rutlier gr^-ater ^ 
than i» sufficient to boil mercury. When strongly heated afl 
portion of it is decomposed, ehnrcoal being left. If it contaiiifl 
nioiftturc carbonate of ammonia is evolved in proportion to tJie 
quantity of moisture present. 

Nitric acid has no action on it whatever, exccpti[i<; that it 
dissolves it when .-Lssisled by heat. It is equally solable in 
sulphuric acid, but without undergoing decomposition or al 
alion. When placed in contact with potiisnum combinatioi 
lakes place, cyanodldc of potassium and potash being formed. 

This acid combines with buses, and produces a genus of 
salts wluch have been distinguished by the name of eifanalt*. 
Jlul tlicite salts have not yet been subjected to cxamiiuiliun. 

From tlie trials of M. Kerullus, tliis acid seems to have no 
very i^triking or injurious effect on tlie animal economy. Two 
grains mixed witli water were introduced into the cesophagua 
of a rabbit, hut ocautioned no sensible inconvenience. 

M. Serullas analyzed this acid by heating it with oxide of 
copper. The gas extricated was a mLtture of two volumes 
cailionic acid and I volume of azote. The loss of weight wiuit- 
ing to make up the sum total of the acid was consitlered u 
oxygen. From this analysis the constituents wer^ dctluccd as 

e in 










38- U 

This is obviously equivalent to 

■ Aon. lie Chim. ei An I'hjv. ixxfiii. 3tij. 

It is therefore ■ compouiiii of an atom of c}'anog;en and 3 
xtonu of oxygon, and its utomic uci^Iit U 5*'25. It contains 
jiwt twice tlie quantity of oxygen that cyanous add does, and 
obriunsly a much tnore hitimate and penuaneiit cooipound. 


In the year 1600, Mr. Howard published in tlie PhilosophiciJ "w-r. 
Tranaactioiiit,* a prooesn for making folminating mcrcuryt 
together willi an account of aome of iJie most remarkable pro- 
pertiea of this subtttance. His process was as follows : In a 
mmuun-d ounce and a half of nitric acid of the specific gravity 
!•.% ditwolrc l>y means of heat 100 grains of mercury. Pour this 
aolution upon tn'o measured oimces of alcohol, an<l apply beat 
■ill the mixture beginw to elTcrrt-itce. 'I'lie licat H then to be 
witbdravrn. 'I'he action hecoines violent, loid continues for 
some time ; a dense white smoke issues from Uie vesitel, which 
i* heavier tlmn the ntmo>ipheric air, and uiiiy be ]>oiin'd into gloss- 
! jans where it continues for some time Uko fine u'lutc clouds^ 
Ateatiwhile a white pow<ler fallii to tlie bottom of the mucture. 
When tJie effervescence is <ncr, tliU white powder is to be separ- 
ate«) l>y filtration, wiuhi-al with pure water, and drieil in a heat 
not exceeding 2 12°. This white crysljdline [>i>wder c«>n«titiite« 
fulmioating inercury. This [luwder expWc« when heated to 
968'. It explode* also loudly when It is wrapt ap in paper 
ind atnick upon an anvil. 

Soon afWrwanU, Mr. Ilonrard, assisted by Mr. Cruiksltanks 
of Woolwich, formetl /aiiniiuititiff silver by a similar ]>ri)cetw. 
Tlic best metliixt of fonning thU formi<laMe compound is tlie 
fvllowiiifr: Diwiuhv n drachm of pure silver in an ounce and a 
lialf i»f nitric ncjd of tlic specific gravity 1*52 (or acid of only 
1-42 or I'-lii wilt do), to this Milution add two ounces of uli'oliol 
of the «|>e<-ifK' gravity 0'S5, and bring ihe mixture (pur into a 
flwJt) grndiuilly toa boiling heat. As soon as an elfervescenoe 
bflgins, white crystalline flocks make their appeiirancc. The 
TCMel must now bo put in a cool place and k-fl at rest, till the 
rffen.'CM.-ence, which continues for some time, ig at iui end. 

* Plul. Jma, IMO, p. 80k 


During tJiLs time the ({uanlity of precipitate greatly increases; 
aud if we wixh to have n^ ^i-at a quantity of fulminating silver 
as possible, we ought (o coo) it artificLolIy. Fulminating Kilrer 
thus prepared, is a much more forniidaltle isiilmt;ince thuii ful- 
minating mercury. It dissolves in Hd times its weight of hot 
water, and er^'stallincs on cooling. It lias a metallic taste, and 
bladcens the skin like other ^aalts of silvef. ^^1len cxfxi^ed to 
the light it becomes lirst reddish, and at hi£t nearly black. Tbia 
fbrmidable ctHnpound, as usually prepared, is in tbo state of • 
powdor. It (lebonat^s much more loudly tlian fulminatiiig 

'I'lioflv two fomtidftble suhNtAncci) had U^eti known tochemtstsi 
uidhad been repeatedly czltibitcd for RtoTPtbun'20 yean, witltout 
any attempt touscertain their nature. At length in the year 1838 
they attracteil the attention of M. Liebig. I le shoiwd tbat they 
consisted respectively of the oxide of mercory and of silver, 
united to a peculiar acid, which be showed to |><»»eiiB a strik- 
ing analogy with hydrocj-anie acid. To (his aci<l he gave the 
same offultnimc, and ho showed that it was capable of com- 
bining with the different bases, and of forming salts, which 
pnsse&s the remarkable property of fulminating. He even made 
a set of Mperbnenls to determine tlie oomjvonent parts of this 
arid ; but an he aftenrards discovered that these original ex])e- 
rimcnw were erroneous, it is ami eccHsary to sperify them here.f 

He repeated his esperimenta with more exactness in the 
laboratory of M. Gaullicr de Claubry, in Piiriti, and carrie<I his 
investigations a good deal tarther; but Htill witlioul reaching 
the requisite decree of aecurocy.t In the year 1824, a very 
elaborate and ingenioiut set of experimcntit, to detennine the 
conHtituenbf of fiilminic acid, was made by MM. (>ay-I.ustac 
and Liebig together.J The conclusion to which they came 
was, that tlic composition of fiilminic acid is identical with tlutt 
oi cytuious acid : namely: 

1 atom cyanogen , . 9^ 
I atom oxygen . . 1 


But to tlib conclusion it may be objected that the properties 
of fuLminic ucid and of cyanoui arid are quite different. All 
the compounds of the lirst acid and bases fulminate by heat or 

• Pliil. TVan*. IHCW, p. KM. t ORberili Anuolen, Ixxii. 391, 

X Aun. dc Cliiiii. ct de I'hy*. xxiv, S94. $ Ibid, ixr, 266. 






Jrictiori, wliile Utc coinpouiub of oyanooa a«td and base» linvt cumvi. I 

IK» fulmiiuitiiig properlics wbtttevpr. L. 

In tilt* yciir I8S(I<, ■ Dcw |mi)er on thu aubjoct wns piihliMticd 

by M. Licbig, in which lio endeavoured to expliitn wlittt. ndces 

I phoe wJicn a fulmiuat« is decooipos«d by Hulphurettcd bydro- 

It was about tliis dme that Uio attention of Mr. Eilmund 
I>iryvnv«dritwn lotlii-seciirioussalts, aiidns thc'DiiliHii Soi-iely, 
to whicli ko !■ profesHor uf chomistry, are not supplied with tliv 
«iHitiiiental journals, be prosecuted Iiis mrestigations for a con- 

' adenble time before he became aware of the proviouN invo&tt- 

gatiou of Oay-Lussac and Lii-bi^i;. Meaiiwlille lie discovered 

that fulminating mercury and Mlver contain a pectdiar acid, 

wkicb bo found tbe i&etliod of coinhintiig witli tlie different 

nea. lie examined tlic properties of tlieec dilTcrent leilte, luia- 

1 Ijrsed tlie fulnunatcs of fiilver and mercury, by which the atonic 
weight of the add wan determined, and after several unituccMih 
fill trials, at hut bit upon a meiliod of obtaining the fulminic 
acid free from a UiSf, and only di.fsolvcd in water. Fiimlly, 
lie analyxed I'uluiintc acid, and obtained results Bomcwhat dU^- 
fcrent hom t]io»c of Gay-Lumac and I.iubifr.f 

Sneh b tbe history of llie iiix'cHtif^tioit of thU very otirioua 

imbMancc. It u now time todescnbe die method of obtaining 
it, and tiu' properties by which it It cbaraiCterized. 

Fulminic acid was obtained in a separate state by Mr. Davy, PniwuiiM. 
by ilic following proceos: Put into n bottle with a frrouiid 
■toppvr, a quantity of fulminating nii^rcury, toi^-tbcr with about 
twicv ita weiyi'ht of clean zinc Hlingt), imd itboiii tlirii' quartern 
of a fluid ounce of water for every '20 frninit of fulmiiiatinfi; 
raercury employed. If tlie bottlu bv kept in a tcmpcnittirv of 
about BO", and occasionally iigilalcd, tlic fulminating mercury 
iiiauon decomposed, aiid a Dolulion offnlminatcofitincobtniiicd. 
Thi" f tquid U to be fillcTol into another bottle, luid nbout onc- 
tbird t>f its bulk of a Katumtetl aqiK-ou* eultttion of barytes 18 to 
be added. Whi^n the mixture is ngitatt'd, tlie oxido of xidc is 
precipitated, and a solution of fulminate of barytee formed.^ 
Tilter llie fulmiiuitc of barytee into another stoppered bottle, 
and add just the quantity of sulphuric acid (previously diluted 

I* Am. de Ctiim. ct dc Phju. xxv. S8j. 
t Mr. Uav/a faptr wa» printed in TmnMclion* of the RojbI Dublin 
Society for 1629. I da not know whether the Tolume Itc yet piililislml. 
But Mr. Dairy «aa to very obliging at la icnil mc a oopy of hin pnpur dur- 
ing the maana of 1830. 
t If loo mticli bwjtci be added the oxide of one b agun rcdiuolvcil. 





with wst«r) that is requisite to naturatc the harj'tcs. Shake 
the mixture, and tlicn filter to separale (lie sulpliatc of Iwr)-tc«, 
Biul l)M iIk- Holiitiun of fulmiiiic- ;tci<t lliux prucurvtl, be coUoctcd 
ijitv luiodicr bottle with » ground stopper. 

Fulinioic ai-!d tliuH obtulni-d is a culotirlvtw and transparent 
liquid. iLt Uwiv is at fir^t sweet, which is followed hy u par- 
ticular aitriiigeiicy, and it leaves an unpleasant imprefuiou on 
tile palate, and excites expectoration. Its Mnell in ptiii^rcnt 
and disagreeable, having some resemblance to tltat of cnnc<Mi- 
tratcd liydrocywiic Jieid. U redden.* vegetable blui.% and if 
a blue paper be suspended over tlie fluid in a bottlt-. It i^nidu- 
all)' acquires a deep red colour, and a sweiitish astringent taste. 
Mr. £. Davy (.-onsidera it an very poisonous; even exposure to 
tlio fumes of it excited lieadaclt. It is voUtile ; when expa«pd 
to the air it risos in vapour, emitting it'* peeuiiar undl, and if 
the vessel iu wliicli it is placed he covered witii a piece of 
glass, nioisteued with nitrate of silver, small ciystuls of fulmi- 
nate of silver soon make their appearance on it 

Folminic acid combine.i witb the dilferent baaes, and f(irm!<'a 
class of salts caiieA/u/iiiiMilrx. From tliese salts it is ex[K'Ued 
by sulphuric, nitric, phosphoric, oxalic acids, &c., miiriatio 
acid, even when dilute, decomposes it. It gives no precipitate 
when mixed witli solutions of burytes or the alkalies. Rut 
Ditnitea of silver and mercur)* form with it fulmiiuites of these 
baaes. Nitrate of silver is a very delicate test of it, forming a 
precipitate of fulminate of silver, even when tlie acid is present 
in only a minute quantity. 

When Iin4t]>re pared fuUniuicacid is colourless; hutitacquira 
a yellow colour in tlie course of a few hours. This cliang« take* 
place whether the acid be kept tn tlie dark or exjwwed to the 
light. But It appears most speedily wh«ti hent is tijiplied. 
.When it becomes yellow its sweet tast« (iinappvara, iuhI it 
becomes more astringent ; a very minute quantity of yellov 
powder fitlls, and then it loses its pungent odour. 

To determine the atomic weight of ibis acid, fulminating 
ulver was analyzed by Mr. E. Davy. He found it oompoMd of 

Fulminic add 
Oxido of silver 



According to this analysis the atomic weight is 5-25. 
tlic couHtituvnu of fubninate of mercury 

He found 


Fkifanbic add 
Oxide of mercory 

28-76 or 5-21 
71-24 or 13 

Tim nmuM mako the atomic weigbt 5-21, which is witbiii lem 
tluui uHv pi-r ci'iiL ol' die toriner tiutnlivr. 

But witL tliis d«termiuati»ii llic vxporimflnu of Gay-Lwwtc 
■m) I,it-1iig do not accord. 'I'licy find the ntomic weight 4-25, 
iasicud of 5-26. 'Hie cuiniKmiuoii uf the acid} as detenniiied 
by these two chemists, in n» foHows : 

1 aliun oyn)i()^n . 3-2A 

1 aUmi (isygcu . . I 


Mr. Davy, on tli« contrary, find* tlie composition a» follows : umiuNhia, 
S atoms cutIkiii . . 1-5 

l| atom uzut4> , . . 2'(123 
1 AloiD hydruj^n . . 0*123 
1 atom oxyg«o . . 1-000 


llliis uuly^ differs from tliat of Guy-LtUMC and Ltebig by 
I atom luote . , 0-873 

1 atom liydtx)gcn . . 0'i25 


The ex peri men (8 of Gay-LusHic an<I Liebig seem to be 
Bwvc rvHfxrctitiK tbc proportion betwcvn Uie volumes of azotic 
liUid carbonic »cmI gas, wliicb ore obtained wlien lliis acid 
decomposed by means of oxide of copper: provid«l their 
itus, which was ratlier cum plicated, did not niiilvad them, 
loverer, the want of tdiniLirity in tbe results which they 
btninvd, iiifretiier with (lie ci-rbiinty that fulniinic acid dilTent 
apletcly from the c)-uoous tioid i>( Wiibltrr (with which their 
Ijnai would render it identical), incline m« to prvfer tlio 
lytical results of Mr. Duvy, accordiiifr m wliicli the fulminie 
diiTeni IVom tlie cyanous, by containing ^ atutn of azote. 
[ atom of hydrogen n-liich Mr. Davy considers as luiother 
itoent t« not so well trKtabli.'ihed. Gay-LusAacand Uc-big 
been at gieut [luins to prove tlie ikbwncv uf hydrogen, and 
Jtiuk tbuir reasoning ut least very plausible. I more than 

■ Ann. (le (^im. ct ilc P\iy$, uv. i$^ 




CMpi t suspect that in Davy's cxpt-rinH-tiW a Ultle hyffromotricftl m<ii»- 
ttire may Iiave iDflinuateil itself JnU) tlic fulminate befow it was 
beated. I think Davy's processes were »iin])li>r, ajid iberefore 
more BUMeptibIc «f accuracy llian th«w of CJay-Liiwac iuhI 
Liebig. Hut tho wiuit of coincidence will render it very drsira- J 
bie tliat tlie iuiulysis of thi« formitiable acid slioiild be repeated " 
by Komt' oilier person, with a view of determining on wliicb 
side the truth lies. 



uaiatr- Tlic existence of this compound was first recognised by Ber- 

tliolk't, who gave it the iianie oi ikri/pntMic acid lU real nature 
WHS first jKccTtnined by, in the year 1815." H« 
giive it tile name of chlwvtytutic iiriil. 

He prepared this acid by pivt.'sing a current of chlorine gas 
tlirough a soluttoti of bydroeyanie acid in water till the liquid 
disculourt-d indigo dimidvcd in sulphuric acid. He tlien deprived 
it of the excess of chlorine which it contained, liy sigiiating it 
with mereurj'. To separate ehlorocyanic acid from xWn* Itquid, 
he took a glass cylinder, filled in two-thirds full of mercury j 
it was then fitted to the brim nntb the hydrocyanic iwid, 
saturated with clilorine, and inverted into a basin of mercury. 
This baain, witli tlie cylinder in it, was put under the rect'ivef j 
of an air<pum]], and the air of the receiver Axiwvn out till tlia 
whole of the merctiry, and even of tlic Utjuid, wiw dispUci.'tlf 
and the cylinder filli-il with ehlorocyanic acid in die »l«te of lui 
etutio vapour. On letting the air into the receiver, the vapotir 
wna condensed into a liquid, and the mercury again made its 
way into the cylinder, lly tliL-* process, tiowever, tlie com- 
pound was only obtained in a st-ite of impurity. Serullas fint ^ 
pointed out the metliod of olituining it ])ure, aii<t gave an »ccu-fl 
rate account oCiXn properties in the year lffiI7.-|- 

t^r<imiian. It may be prepared hy the following process : Fill a boUlt 
or flask, capable of holding about 60 cubic inches, with chio* 
rine gas, and tlien put into it from 77 to 90 grains of eyanodide 
of mercury. As much water is now to be introdnctil 'm will 
reduce tlie cyanoditlc to » magma ; but not dissolve it 'Jlie 
vemel must now be placed in the dark, tn about or 10 
hount a double decomposition will liave taken place ; the mer* 
cury will be converted into corrosive sublimate, and the cyan- 


• Ann. <l« Cliini. xev, 186. t Ann. do Chiin. et dc Phys. usv. 

ctn^nocvAKic acid. 


conthined witli chlonn« will fill lh« vc«svl in the ttate of 
fc If tlie fbitk be nuw stirrounded with ft ftveziog mixtnre, 
reoapuMd <(f 2 pitrU of niiow tind 1 giart of suit, tlic chloride 
C)'iiii<>^!» lA cuiiv«'Tt4.><l itiut solid crystals, which attach 
Fin»eh-c« to thr »i<li-« of tlie flusk. While the fla<ik i§ in 
freezing mixture, introduce into it a quaiidly of dry 
*ie of calcium to shaorb all the water, luid corkttig tlic 
I, leare it in thin state for two or three davH. Then Mir^ 
id it again witli a freezing mixture, and whi-n ihv chlondp 
i cry»tal)t/cd, withdniw the chlorkle of calcium, and fill tlie 
Suk with nicrciiry. previously cooled down to zcra Introdiloe 
a bent tube into the mouth of the dask; plunge tlie tube into 
a mercurial trough, uhI c»uti<Hwly healing the flank hy means 
ofa fiew pieces of burning churctKiI, jibced near it, the chloride 
^ flucs Uld eScrvcMM-^ luid imjwcs over rapidly into tlic mercurial 
DUgh, where it m to be rrcvivctl in jan prf viouiily filled with 
ry. and rpudy prepared for the purpoHe. 
Joride of cyanogen at zero is a tnuis|)arent solid, which 
llines in long traiKparent needles. U liquefies when heated 
to the temperature of about 15° or 16°. The gas liquefies 
tL'm|verature of 68* when exposeil to a pressure of four 
ilwrM. Al iJie ordinary temperature of tlie air it is 
No alu-inpLs tiiiv<- In-t-n niaile to determine its spe- 
gnirity in the ga«eou8 stute. Hut it '» obvious that it 
iWt Iw the mean of lh« ^edftc gnivity of cyain^'ti aud ehlo- 
ne gMses, or 12-1&27. Its smell is eXircmcly utlensire and 
At Die tcmperntitre of 68^ water absorbs 2& tiroes its volume 
ihiv gaii, sulphuric ether ubAorhs 50 times its volume, and 
i^hol 100 tunes its vuluroe. lliese solutionti may be pre- 
red any Iragtli of time without ailcTntion. When pure it 
not prccipitBtv nitrate of mercury, nor produce any allct- 
I (in vegetable blues. Nor docs it seem capable of com- 
■g with ba»es ; at least we liave no evidence thai it can be 
Willi tiiem. Potash when added to its aqueous solutioo 
ibi <leci>iiipo«iliuii, curfioiiic acid and nmraonia being 
We liurc iherefore no evidence that it ponesses acid 
Itertiea. On that account the term chloride of cyanogen is 

appropriate name for it than chlorocyanic acid. 
It ha« the property of tlirowing donii iron from itsmlution.s 
fa green colour. The method of proceeding is to pour chloro- 
irpiiic add into a solution of iron, to this mixture a little potash 
lii ulded, luid, finally, a Uttle acid, which produces the prccipi- 





cvanooek accds. 

chmp, 1. tution of tlie iron. This property wna rwognlticd t»y BcrUinllet) 
Kiid induced him to consi(t<.*r chloride of tyiuiogoD as a peculiar 

This substance is very caustic ; even when it comeA for an 
instant in contact with any part of the body deprivctl of the 
»kin, while in tlie state of ga*, a feeliitg of grent fam takes 
plaee. It i« «1ko exc(-c<lingly deltiterioiiii. About u ^in of 
itdiiMlvcd ill water bciiig introduced into llie tliroat of a nibbit, 
occasioned instant death. 
compoiuoD. It nffag analysed in a very ingenioiw manner by M. Gay- 
LussaCf who showed it to be a compound of 

1 voliune cyanogen gaa . . 3*25 
1 volume chlorine gait . . 4'5 



united together without any alteration of volume.* This 
analysis was repeated and confirmed by Serullas, who employed 
pure chloride of cj'HDogen. It is obvioust therefore, that Ita 
atomic weight is 7'7r», and ibat its specific gravity is tlie mean 
of tliiitof it9 two |r;i3eous coiiNtitueuti, or It IS the atomic Weight 
multiplied by 02777. Var 0-2777 X 7-75 = 2-152/, which 
is exactly the mean of that of the two con.«titui^nt8.t 


BiMn. This compound was also discovered by M. Serullas, by pro- 

secuting the experimentjt detailed in the hist section. It may 
be obtained by the following process : 

mvuium. . Fill a bottle capable of holding about 65 cubic inches with 
Ary clilorine gas, and after putting into it about 15 gnins of 
pure liquid hydrcnryanic iieid, shut up the moulli of the boUlfi 
with a ^ound utopper, expose it to tlic cliroct rays of tlie suit. 
-The colour of tlic chlorine gradoally dis<ippe:aTS, and n colour- 
less liquid like water begins to appear on ihe Kiiles of tlie 
bottle. Tin* liquid griidimlly thickens, and at last solidifies into 
a while matter interspersed with small brilliant crj'stals. The 
bottle must he allowed to remain three or four days before it 
be opened, in order to be «ure that the deeomjio«ition bus been 
carried far enough. Then tite buttle being opened, the nn- 
rintic acid gas is to be blown out by means of a pair of bellowa; 
Then introduce a little water and a good manv IragineiiU of 
glass, in order by agitation to detach the solid matter from the 

• Aon. de Chiio, scv. (Ott f Aon. Ju Chiiu.M de Pli)». iixv. 



iea of the reiBwl. AgiUitc well, then throw tlie wliole con- (^mvi. 
enw into a diitli ; pick out the pioww «f gUws, and bn'iik Hui 
rliitt* mattt'r u'itli a glasi rod to allow it to hv wtisliod. Wusli 
twit or tbn'f times with small cjuaiititit.'s of cold water. Press 
thr whit4- matter thus washed between folds of blotting; paper 
to make it as dry as pitKsihk-. Introduce it now into a small 
Klort, and heat it till it fusea. Then distil it over into the 
Kceiver. It puniifif oviT in tliv Ntatc of n trj|[ihpur<-iit oolonr- 
len liquid, which cry)^t»lliz«'8 in tlii; beuk of tht.- rt-Iort uiiil in 
th« nMsrivttT. To render it quite pitro it oiiglit to bv distillvd 
I second timv. 

Percbloride of cyanogoo thus obtained is a v«ry white sub- Prorwu* 
*tance, which crystaltties in needles. Its odour is strong and 
dingreeable, and excites tears, especially if the pi?rcLlonde be 
heatetl. Serullas com|KireK the «mell to that of viiee. Ifg taste 
«harp, but not .iirurig. Its specific gravity is about l'-1'20. 
tocltit when heated to 264°, and boils at the temperature 
■ 374". 

It is very little M)lublc in cold water. Hot water diwolvtss 
Ek much b4-tt4^'r, and the solution speedily umler^ocs dccompo- 
flition, being converted into muriate aiul cyanic add. Tlic 
I aune decomposition takes place slowly, if the perchlondc he 
'left iu contact witli culd water. Twoatoms of water luc decom- 
posed, the hy<lroK«n of which converLs tlie chlorine into mu- 
! acid, whil« the oxygen converts tlie cyanogen into cyanic 

Pcrchloride of cyanoffcn diwolvcs readily in alcohol and 

ther. It is u verj- virulent poiiwn — u grain of it dissolved in 

Jcohol being introduced into the o^iopbugus of a rabbit, cauHcd 

il death. ,\notbcr ^uin wiw put iiilo :J0 grammes of 

Br, which was filtered to scpiinite the uniliwsolvcd jiortion, 

then given to another tsbbit. The animal died in 2d 


M. Senilbw, in order to determine its composition, mixed a caaivmiuaa. 

tion of it with caustic potash, then heate<l it with an excess 

"nitric aciil, and threw down the chlorine by means of nitnitc 

I silver. I'i-'ia grains of it were found to yield nine griung 

r chlorine. To determine the other constituents it was heated 

Ivfth oxiHe of oopp«r> and the proportion of carbonic acid and 

I votic gases evolved me^ured. Though this Uist ptirt of the 

[analy»i'4 did not eome out correct, yet from tlie way in whicli 

ihia iH^rchlortde is decomposed when it is left in cuiitJict with 

water, and from the quantity of chlorine which it contains, there 

240 Ct'AKfH>F.K ACIDS. 

I <*T-'' of cyanogen. ToobUun it quite pureilisnecessirj- tosruWime 
them. 'HiU vm <tonc by ]iiittiii|r ihcm into tlic bottom of h 
long glass tubtr, shut at one end, winch vrsa plunged in boil- 
ing water, and kept in it, while the upper part of the tube was 
bent a Utilir. The iodide gnidiinlly sidilimed into tb<- upp^r 
part of tlitt tube, wliilc some iodide of mercury rvnuuned at tie ^ 
bottom. ^1 

TnfHiit^ Iodide of cyunogen thus obtAincd is wbilo, and w crytttnlli/oii 
in very slender but loiig needles. Its smt-ll is powt-rful, irri- 
tating the eyes and causing a flow of tears. Its taste is e.Yces- fl 
Hvely caustic. Its specific gravity is greater than thai of sul- 
phuric acid, tlirough which it falls rapidly. It it volatile, and 
may be oipnsi-d to a higher temperature tlian tliat of l>iHt- 
ing water untboul undergoing dccainjxwitiun. When tbrown 
on burning coaU violet vajioiirs arc ^ven out in itbutidance. 
It is soluble in water and in nlcoboL Tliesc solutions produce 
no alteration on vegobible bhies. When caustic potash ii 
added to the acjueous solution the iodide is immediately decom- 
posed, hydrioitiitc mid hydroeyanate of potash being formed. 

Nitric acid lias no action on it. Sulphuric acid is not imme- 
diately affected by it. But after a certain time it acquires a 
red colour, and iodine is predpltated. Muriatic acid decom- M 
poses it, i«<l!ne being precipitated, and hydrocyanic acid formc<L S 
SnlphuroiM ac!<l decomposes it immediately. Iodine It dlwn- 
gnged, and hydriodic acid, hydrucy-uiic add, andKulphuncacHl, 
are formed. It U obvious alwi from the phenomena dcscribedl 
hy Serulhis, that snnie sulistaiicc anutogous to chloride of ej'ail-] 
ogen is formed, as siilpliate of iron is precipitate green, after 
kll the sulphurous acid and hydrocyanic acid ha.s been driven 
off by heat. If sulphurous acid gas he quite dry it luis no action 
on this iodide ; the presence of moisture w ncccwaiy befoi« the 
action lakes place. Neitlier liati dry chlorine gna any action i 
it, ut least sit the ordiuary temperature of the atmosphere. 

SeruHiis maile a set of experiments to determine itK compo*! 
sition by ascertaining the quantity of iodine which it contaiiu^ ' 
He found that one part of the iodide coiilnin^ 0-8056 pari of' 
iodine. According to tliis result itn composition is 
Cyanogen . . . 3^5 
Iodine . . . 13*55 

Tbougli the quantity of iodine obtained ia ratlier le«s than i 
atom, yet considering the striking analogy wliich tim substance 
bears to the ch[uri<lt- of cyanogen, there can be no reasonable 
doubt that the true compttsition is 






1 atom cyanogen 
1 atom iodino 



aaA that ita atomic weigtit u \Q.* 
^^ TKU io(li(t« seems tnucli lewi Heteteriotis than either this 
^Bnnulr or cLliifiile of cyanogen. Serulla.'i taste*) it repealeclly> 
^Biil both be luiii !teveral oilier individuals were expoiied to tlie 
^HkBMB of it witlioul experieticing any other inconvenience l)ian 
^B prostration of Htn'iigtli, and tliv diauj^rceable irritutioii witli 
^■rliich h affected the eyoa. 


" This aeid was diBcovere<l by Mr. Porrett in 1808, and an hhic«t. 
■ccount of it publisJied by him soon after, under tlie name of 
fn ummt aad, beeauM he coDsidered it ai differing from eom- 
pnuric acid by containing leis oxygen.f Me afterwards 
ed tJtat it contained sulphur, ami jiublUhed a detailed 
t oril9 properties, in tlie year 1^14, under tlu: name of 
ckj/asic arid, considering it iW u compound of 
ante acid and siil]ihur4 
nt though it !■ to Mr, Piirr»'tt'« ing^eniouti e;tperimont* that 
Ae cltetniAbt of Great Dritiiin and France were indebted for' 
their first knowledge of this add, it appears from ii paper of 
Ber^elius^ that it was known long before in Germany, though 
hail (trauii but lilde of the attention of chemists. In a pnper 
iDblbhed by Wijiterl in 1790 on the mode of preparing />nf«- 
qf j/nttuh, he siffirmed that if tlie mixture of Mood and 
from which tliU prussiate is mudi- he chiirrcd without 
;irw to II red heat, a new compound is formed which may 
rxtnicted by itlcoliol. This, he xiiys, is a compound of 
and II n«'W lu-id which he callit arid of blood (btitt- 
•t), and ii'hicli he tudil mi^ht be thrown dotcn in the form 
of a white powder by means of muriatic acid. 

Bucholz found in 17!>9 that if pnt><«iate of potash be dis- 

tiUed witli sulphuric acid, we obtain tonitrds the end of the 

acid which has the smell of the hydrocyanic, but 




'Aon. lie CStim. e( de Pbjrf. xx%i\. IS4. 
f ISiUidMil in ih« miJi volunio of iho TVariMctioD* of the Society for 
llw Baea uf ag M Dwt of Atu, MsniilsciiirM, wid Comuierco. Prom which 

Ik b tofM into Ibc PUI. Mag. nxri. 194. 
iPULTrMi*. IdU.p. Ad7. 
i Kol«. VcUM. Acad. Hnndl. 1920, p. SS. 
II. B 



which colours fvmig;inoiis salta red unthouc occuMoniiig xny 
prccipitiile in them. He considered tliis new acid )u a ntodifi- 
cntioii of hydrocyanic add, and thoufj^lit tlmt It miglit he 
obtained by the action of alcohol on ordinary prns'^iiili^ of 

In 1804 Rink repeated the cxpcrimcnto of Wiitter). He 
found that be!>ide4 uoininon pntwiiate of potasli anotlier suit H 
obtained nolidile in nlcohol. Tlif projierlies of which be 
dcscrilw-i, nnd from bis dcHcription it is obvious lliat ilie acid <rf 
this ndt wtis precisely the some as tbc sulphocliyuzic avid «f 

Mr. Porrctt's process for obtaining this add vns very oom 
plicated and tedious, hut in 1817 GrottliuM proposed another 
which b much easier.l It consiitted in mixing ferropnigstnte 
of potash and suEphur, and fusing tlie mixture in aii open cru- 
dble ; an<l be recommendit expoung the mixture to a very hi^li 

Soon after \^ogel repeated the experiroenta ofGrotthitas, and 
found that his proceitft ituccvt-ded v<^ry well, but tliaC the mix- 
ture ought not to he exposed to so hi^li a u^mperature as Grot- 
tluiMS hud proposed. He rocommendrt to fuse tlie mixture of 
fciTopnissiBtc of potiudi and sulphur in a pUiaL, and to keep it. 
in fusion during half an hour.;!: 
i1 Berzelius made a set of experiments to determine the tcnft- 
pCTDturc necessary for causing a cumbituition to toko phce 
between tbc cyanogen and the sulphur. He found that it 
commenced us soon as the sulphur began to melt, luid that it was 
speedily completed. If the mass was kept in fusion tlmt por- 
tiou of the sulphocj'anogen, which was in combiimtion with ibe 
iron, underwent decomposition, and sulpliuret of iron was 

The process by wliidi this acid may be most conveniently 
made is the following: Mix togetlier intimately by trituration 
equal weights of flowers of sulphur and forrojirussiateofpotul^ 
previously deprived of itiii water and reduces) to a fine powder, 
«i)d fuse the mixture over a spiriulimip at a t(fm|>cratUTe 
appruachiriff to u red beat. Mlien the fused mats bus bei'otne 
cold dissolve it in water, and drop into tbc solution caustic 
pota.«li (ill tlie oxide of iron lias been all thrown down. It b 
tlien filieretl. F.vaporalc the colourless liquid thus obtained to 
dryness, and dimolve the dry residue in as little water as 


• Oehlen's Jour, H. Wft. t Scbwci(U!cr*« Jour. \x. Hi. { l*"'"!- »*"■■ ' 

itc»t portion of dti-i iiubsiaii«e predpilaki^miPiwiii'n 

I oooU. TW prt>Hen«.- of Miipliur in «nhiiion in it nuty lie 

I by ititiatc of silver, whicti tlii; acitl, wliilit ptiro, throws 

Ittbt I but the colour of the preciplUiU! in ilark when 

contains sulphur (liiuolvod in it. It eryaUUixe* when 

jdou-Q to lh« letnpcmtiire of 14°. It boila at the tem- 

p of 216^°, uod uttluit tompcruUire it tscoim>rtcd into 

bat uot iiito gM. When (he uciil i» tlironii iniou red 

ilium cnicihlCf Hulphur is (lis«rif^f;iti, and at last liiiriis 

bltte Itimc. M. \'o>r(>) passed the acid ttirouj|;h u n:A 

bituin tulas luitl obbiined nt the brthor end of it sulpliuri 

llphocyanic acid un(lt?«om{HMed, and hydrocyanic acid, 

ptu partly wttunitcd uith ammonia, ll' tlic tube be filled 

m turnings, Hulphuret of iron is formed, and hydrocyanic 

1 sulphuretted hydrogea disengaged. . 4>i 

bUos proposes tlie following us the eu«o«t method of 

1g Hoa acid diluted n-ith water : MLt tlie sulphocjanate 

Muni with nitrate of silver or nitrate of mercury. Wash 

dpituto and mix it while ><titl moist with water, through 

a current of Milphurcttcd hydrogen gas b to he passed. 

Iver or mercury is converted into Kulphuret, while th« 

tUpiiocyanic acid fttssolvea in water. We may get rid 

sulphuretted hydrogen remaiiiinji; in the li(|U>d eitlier 

entle e\'apuralion, or hy adding small quuntitiet of the 

J precipitate kept for the purpose till tlie hepatic AincU 

eon. Should this acid over be introduced into medicine, 
■t I., ■.■■■■■.ill...., .1. ^— :i.. 


Q***- that peroxide of iron is capable of detectang a very minate 
qnanUty of this add. 

Hydrosulphocyanic acid when left to itself ondergoeB gn- 
dual decoroposition ; a broTn liquid being formed, while a 
yellow matter precipitates. Chlorine decomposes it, producii^ 
the same yellow matter and hydrocyanic acid. When decom- 
posed by the galvanic battery, hydr<^eii is evolved at the 
negative pole, while cyanogen and the yellow matter appear at 
die posiUve pole. 

Tbia acid was decomposed in a very ingenious manner by 
Mr.Porrett,* and his experiments have been confirmed by those 
of Berzelius.f The constituents are 

1 atom hydrc^en . . O'lSS 

2 atoms sulphur , , 4*000 
I atom cyanogen . . S-250 


So that its atomic weight is 7-375. 

There can be no doubt that the compounds whi<^ it (a/mm 
with the bases are destitute of hydrogen, and that the bases are 
in the metallic state. These compounds, therefore, constitnte 
in &ct ndphocyanodides. Hence hydrosulphocyanic add must 
be a compound of 

1 atom sulphocyanogen . . 7*25 
1 atom hydrt^en , . . 0-125 

Sulphocyanogen then must be the radical of this add, and it is 
obvious that it must be a compound of 

2 atoms sulphur ... 4 

1 atom cyanogen . . , 3-25 

^g* From the experiments of Wiihler compared to those of Liebig,| 
there is reason to believe that the yellow matter whidt makes 
its appearance when the acid is decomposed by galvanism, con* 
stitutes this radicaL Liebig obtained it by mixing together 
one part of a concentrated solution of sulphocyanodide of potas- 
sium, 3 parts of water, and from 2 to 2^ parts of nitric acid of 
the speinfic gravity 1-42. This mixture soon deposites a good 

• Annala of Philoaophy, xiiL 105. 

t Kong. Vrtens. Acad. Hondl. I8B0, p. 89. 

t Ann. de Chim. et de Pbyi. sli. 190, 



nhmte of poMsli. If the liquid be decanted nflT liieae (><uvi, 
s, uid^ntly heated, it speedily effen-efloes with vbleiicc, . 
ide of Bzote, carbonic acid gas, cyanogen, .-uid liydro- 
acid arc exhaled, and the yellow matter is depositt-ii in 
A CHirent of chlorine passed through the hot solntioii 
ihocyaiiodide of potassium causes the precipitation of a 
leal of the yellow matter. 

I yellow matter when drii'd diiniiiuhcs very mnch in bulk. 
1 Roft, and colours the Hkinwitli grL>»t intensity. ItrvtAins 
with great olMUiniicy. Woblcr considers this yellow 

a« a hydrusuljihocyanogcn ; but 1 think that the exp«- 
8 of Liehig luive »hnini that it conttuns no hydrogen. 
the ■luilyHut of it by thin last chemist, I have no doubt 
U u compound of '2 atoms sulphur and I atom ej'anogeii. 
t tlirrcforo be the radical of hydrosidphocyanic acid. 
>hocyanogcn ts insoluble in water and alcohol. It may 
iluoed when anhydrous (at least the greatest part of it) 
it undergoing decomposition. Xitric acid decomposes it, 
ric acid, carbonic add, and ammonia, being )iroduL-(-«L 
irk add (ttMolvea it without alteration, and water again 
itntes it from the Mtiiition. A aolutiou of caustic potash 
OtduBolvp it, but it cliangrs itt colour to red, and If we 

off the alkaline solution, alcohol <lwMolvfs about oiie-liolf 

red matter. Vliat remains iindiKwIved lias a yellow 
, Liehi^ considers it as a sulphocyanagen containing a 
r quantity of sulphur. By Licbtg's analysis the compo- 
oS this yellow matter is 

tCyanogcu . . 3-25 
Sulphur 4* 111 

it excess of sulphur may, without scruple, be con- 
1 as owing to inaccuracies in the analysis. 



» double acid wa» discovered by M. Zeise, during his hmoit. 
ches on the alterations to which bicarburet of sulphur is 
led under peculiar drcunislanwii." He obtained it by 
Iknring pt-oceiw: 

imte absolute alcohol witli as much ammoniacal gas as it 
Morb at tlie tempetaturc of 50^. Mix it witli H-4 of its 
d volunc of alcohol, and with 0'I6 of tluit volume of 

• Atm. de Chioi. et ik Pby«. xavU Tf. 





bicurburel »f Hu!|iliur. llic mt^ctiirv shoiiUl be made in a phial, 
wliicb ought to be completely Rlk-d with it. Lrt lb« fibial be 
well stopjtcd and k«ptin thv tcmpcnttiirpof6Q°. Witliiuabont 
an hour and a half a salt fiiik in crystals. 11ii» sdt is a com- 
bination of siilpliuret of ammoDiiim with bicarbiiret of Milpliuf. 
i'ilt«r the li<]iiid as rapidly as possible tliroiigh a clutli into ^ 
another phial, which must be hormotically sealed, and after H 
faiiring been kept for six liours at the temperature of 60° is to 
be cooled down to 4(1°, iiikI then phuigi-d into a muttur* of 
snow and milt. By this treatment another salt is obtained, 
which is a combination of sulphuret of ammoiiiom with hydro- 
sulphocyanic acid. Separate this sail, wa&Ji it with » liltk-:dcoliol 
cooled do w» to 33, and tlien [irei«i it between the foldsof blotting 
pi^er. Dinwlve it in three lime!< if* weight of wnte r, and sdd 
to tbe solution muriatic acid orsulphuriciictd, diluted with twice 
Its weight of water. After the liquids have been well mixed, 
pour in at once a great iguanticy of water, an oily looking mat- 
ter ia collected at the bottom of the vessel, which is Ajfdrwtit- 
pAuretted hydrosnlphon/nnic arid. 

This double acid is colouHem; but n-ater decoinpo««8 it m 
rapidly tliut M. Zei»c could not examine its properties, %\'ben 
it is placed iii contact with a metallic oxide, the oxide is imme* 
diately reduced to a stdpburet which combines wiib the hydr»- 
Stilphocyanic aci<l. Thus it appears that hydrosulpbocyanic 
acid, lliough iiiciipahle of uniting with an oxidi/ed base, enters 
into combination witii u i^ulphurcttcd Ivue. If we heat the salt 
the hydrogen of the acid unites to the sidphur of Uic hose, and 
flics off in tlie ntate of cnilphuretted hydrogen gas, while a , 
metallic sulpliocyanodide remains. 
Tlii* double m-xA is a compound of 

I atom suljihuretled hydrogen . . 2-I2& 

1 atom hydroaulphocyanic acid . . 7-375 



i acids de- 

Its utomic weight is 9>5 ; and like various 

scribed in the class of oxygen acids, it only saturates as much 

ba«e as cither of its constituents would do if in a sejwrate state. 

secrioK XII. — or hydsobisulphocvakic acid. 1 

*l1iis compound add was discovered by M. Wiihier, aiKl 1 
notice it here though tbe investigation of it is still lery incom- 
pli-le, to mnko the reader aware of the numerous compunnds into 
which eyimogen and sulphur enter. 


^^Iieii Eulphaoyaiiotliile of inurcury ii gently heated in sul- 

^hnrctiiNl hvilrc^n gna, «r iii miiriativ act<l gas, it uiidergOM . 

Vt-uRijinsitiou. mtti »til|iiiuri>t or cbloriHit of mercury is formed, 

;eU)«r wiiLi a litguirl wliiuh is dcpoHitod iti tlic cuMt^t jmrt of 

vcwel ill (lro|M. 'Ilicy arc at firKt coloiirlvw ; but noon 

DO yellou', aiul furm Hinall tmiisparviit crystals f^upcd in 

ThvM crystals grudiia]ly undergo BpoiilaniM>us dccom- 

NMidou, liydrocyuiiic add being gWen out. and an orange yel- 

opeqnr, suWance reiDains, u-liicli i^ inuiluble in water. 

Viihlcr considers this matter m a compound of 

1 atom liydmfren . . 0*123 

4 atoms aulptiitr , . 8 

1 atom cyano^u , , 9^5 

ft. ma. 

' tlita opinion ba.1 noi yet been establiftbod by nnaljuti. It 
ocrtaJn ut IriL'^t tliut it contains liydrugvn, lunl murv siiljiliur 
I oaista in hydrosiil[>bocyaiiic actd. For wbt-ii Imitcd with 
rinn Acurabiniiiiun tuki-spluccwithtbe evolution of li^lit, 
gaa is givpu out, and the product is a mixture of huI- 
pltur and sulphocyunodide of potasnum. The radical of this 
^udd has not yet been obtained in a separate state ; but if 
^K^ohler's opinion be correct it is doubtless a compound of 
^^^^b 4 atoms sulphur 8 

p ,.„„ . . .„ 


P T! 

, its aUMnic weight is 1 1-25. 


TIlis is « compound discovered in 1838 by M. I.a>saigne, BMcvr. 
anil descrying to be described on account of it*, curious proper- 
tie*.* It was otitaiiieil liy tkc following proc«!is : 

Into a snuill globular glass vessel some cyanodide of mercury rnrumuon, 
wmt (Kit, nfier having been previ»u.sly reduced to it fine ])Dwder, 
and over it wii^ poured about half its weight of bichloride of 
sulphur. I1ie vcnscI w»s tlnni closed, and lelV for a fortnight 
cxpcwrd to tite nrlion of lii;lit. A number of Mnall crystals 
WCTV gradually deposited ou the upp«r [lart of the glnits. There 
Tviuained at the bottom of the gloss a considerable qitandty of 
• sublimate, mixed n-itli a yellow coloured matter. 'Ilie 

* Ann. Ac Chim. et <lc Phjv. xxxiv. 107. 



f^"^ L crystals were purified by mixing tliem with a quantity of cai^ 
bonate of lime, and then subliming them. When thus purified 
they possessed the following properties : 

fmaOm. The substance is transparent and colourless, and tbe crystals 
are rhomboid&I plates, similar to those of chlorate of potash. 
When a rery minute portion was applied to the tongue, it 
occasioned as much pain as if a sharp instrument had been thrust 
into the place. The part touched became red, and continued 
punful for some time. It has a strong sme11,-Bomewhat similar 
to that of chloride of cyanogen. It is so volatile that it sublimes 
of its own accord in close vcsseb, at the ordinary temperature 
of the atmosphere. When esposed to the light it becomes 
yellow in a few weeks, and finally orange, without losing its 
chemical properties. 

It dissolves readily in water, and is still more soluble in 
alcohol. The aqueous solution strongly reddens the tincture 
of litmus ; but the alcoholic solution produces no change on 
litmus paper, till it has been exposed for some time to the air, 
when it becomes red. It appears to have the property of com- 
bining with, and neutralizing the bases, and therefore is entitled 
to be considered as an acid. 

It is decomposed by galvanism, sulphur being depouted at 
the positive pole, and hydrocyanic acid at the negative pole. 
When potassium is placed in contact with it, a combination 
takes place with the evolution of heat and light, sulphuret and 
cyanodide of potassium being formed. 

Lassaigne determined the proportion of sulphur which it con- 
tained, by uniting it to potash, and calcining the salt with six 
times its weight of saltpetre, in a silver crucible. Hie mass 
was saturated with nitric acid, and precipitated by miutate ot 
barytes. He obtained as a result, 

ccHpmmca. Cyanogen . . . 76*8 

Sulphur . . . 24-2 

Now this approaches very nearly 

1 atom sulphur . . S 

2 atoms cyanogen . . 6-5 

It would appear ^m thb that it is a compound of 1 atom of 
sulphur and 2 atoms of cyanogen, and that its atomic weight 
is 8-5. 


TIiUcoin|)aiin«I was discovered !>)' Hen!elius.Bndina(lekiiown umb;. 
(o the chemicul world in liU [naper on bydrosulpliocyaiiU: uvid, 
fttready rererrod (o." The pniceas employed for foriojiig^ it wis 
the Mmc OS that wliicli Htiix-LH-^tK in forming liyclrosulphocyani« 
■cid, only sulwtiliitiiiji^ sflenium for Hulphur. When » mixture 
of selenium and anliy<lrKU« forropnissiaU' of potaKti i% lii<«tod, 
it fuses, iiud we obtain a substance soluble in water mid nlcohol. 
When we evnpumte tlie solution we obtiiin ery»tuls exactly 
iimiLir to tho«w of sulpliocyan«di<le of pota^um, of which they 
late exactly the (aste, but they an^ ratliermore soluble in water, 
md deliquewe more i^iieedily in a inoJHt atmosphere. This 
■Alt contains neilber water nor hydrogen. 

Bot though tlii-H wilt is permanent, and tliough, doubtless, 
odier aalU cimtaininfr seleniocyanofrvn may be formed by 
doable deootn}MRiiiiin, yet Ik-rjidiiu wa» unable to obtain tlie 
M-lrniocynnn^n in a wparate stale, and far less n hydnwele- 
DM>c)'»nie aeid. 'NVlien an acid ^\as added to llie »aliiie 
wlullon, tlie fteleniocyanogen always underwent deitimpntfilion, 
irleiiium Itf'utg prisripiUited, and when the mixture vniH di»lilled 
aa tkcid whatever rame over. At tlie commencement of tliu 
illation {when sulphuric aeid was mixed with the solution 
of tht salt) die liquid had a most powerful and exeessively d»- 
■^recable smell ; hut as it ])o!tsessed no aciil properties, hecon- 
ridera Uus sjnell as proceeding from a combiuation of selenium 
and sulphur, a compound not yet known. 



The MiJt formerly known by tlie names of pHloffUticaltd \vav*% 
fatikaiif pnugiate t/f ftola»Ji, &ad J'crropmsxiiUe qf^ potanJi, was 
ditcovered by Macqiier, luid was originally em[>loycd to detect 
the presence of inni in liquids. It was introduced into calico 
printing a good many years ago, in consequence of which il 
uoa bef^i to be pre|Hired in large quantities by tiie chemical 
BMMiufaciunTS in this country. Tlie tint man u factory of it vm 
flMnblislied at Cam]»ie near Glasgow, by Charles Mucintush, 
Cm|., where it is still prepared in large quantities and very 
pure. The process consists in burning the hoofs of cjiitle mixed 
wttli saltpetre in iron pot*, lixiviating what remains allerthUprcH 

Kiind ■«-iiing the liquid n»idr when sufltcienily eonccntruted. 
liluJerystalsof tlie fcrroprussiatcare formed in large group*. 
* Kongl, Vcteni. Acad. llontU. IfiSO, p. »7. 


""p-*- This salt has a fine yellow colour, is transp&Tent, and when 
p„„,i^^ held between the eye and the light it appears greeo. It is 
■""■^ crystallized in four-sided plates with bevelled edgea. If we 
suppose an octahedron composed of two four-sided pjrramida 
applied base to base, and the apex of each truncated very deep, 
we shall have a pretty accurate idea of the appearance of these 
crystals, which are usually two or three inches in cUameter, and 
about half an inch thick. The common base of the pyramids 
is a square, and the inclination of a face of one pyramid to the 
corresponding face of the other pyramid is about 135°. Hence 
the inclination at the apex of the pyramids is 45°. We see that 
this octahedron is much longer than the regular geometrical 
octahedron, the angle at the apex of which is 70° 31' 43*^. 
Tlie specific gravity of this salt is 1-833. Its taste is saline 
and cooling, and not disagreeable. Its structure is foUsted, 
and it may be split into thin plates parallel to the base of the 
pyramids, which are tough, and may be bent without breaking. 
I found the solubility of this aalt in water as follows : 
At 54°, 100 water dissolves 27-8 of the salt 
100 .. . 65-8 

150 .. . 87-6 

200 .. . 90-6 

The solubility does not much increase by any augmentation of 
temperature beyond 200°. It is insoluble in alcohoL 

When moderately heated it gives out water, and 16*625 
grains of the salt gives out 3-375 grains of water. By this 
process the salt is not altered. For it may be dissolved in 
water, and obtained agtun in crystals as at first. But if we 
expose it to a red heat the salt melts, becomes black, and 
acquires a strong alkaline taste. If we now dissolve it in water 
it leaves a quantity of ferruginous matter behind it, and wd 
obtain, by evaporating the water, a white salt which is a cjrano- 
dide of potassium. 
Mioompo)!. Berzelius" has shown by a set of accurate experiments ihaX 
the constituents of this salt are 

2 atoms potassium . , 10 

1 atom iron . . ■- 3-5 

3 atoms cyanogen . . 9-75 
3 atoms water . . . 3-375 

■ Kong. Vctens. Acad. Hand!. 1H19, p. £47. 


■The wnto 


The wntor contuins jiutl the quantity of hydrogen npc«smry to ^'i** vr. 
ooorert the cyanogen into hydroc)-anic acid, and llie quantity L. 

of oxygen requisite to convert the pAlatsiiin) into poliish ;ini) 
Ihe mm into protoxide. We might tJitTefore eitlior coiutider 
e salt as a conipoiuid of 

S ntoms hydrocj-anate of pola.<)li, 
I atom hydrocyanate of iron, 
3 atontti cjiiiiaiiidc of potnitsium, 
1 atom cynnoditle of iron, 
3 atonu water. 
lorfs there any ex|M-rimcntid mcaw of dedding which of tbcM 
TitWB b tltv true otie. After the wdt hM been deprived of Its 
mtrr by Ik'M, there can be no doubt tltat it comists of two 
UoiB* oyBDodide of potaMium and one atom cyanodide of iron ; 
and KB we can restore the wntor si^xin hy Nimple solution and 
cryKtoltimllon, it i* must natural to ronsider thi- ftait oven when 
oynttillizcd iM n double cyanodidc with wutcr of cr^'sUillizatioii. 

W'ben sulphuric acid Is poured upon the ferroprussiate of ^JJJ^ 

^^^Bfth in powder greni heat is evolved, tlie salt becomes white, 
^^HnHien hcAt » applte<t a gas is given out uhundimtly. Tliis 
gaa ftmelts strongly of sulphurous avid, showing timt tlie sul- 
phuric acid i* piirlly deeompoAed. There is ttUo former! a Hitle 
mmotua. The gas which cnmeil over w eombu<.tible and burns 
wttli a blue flame. I confidered it at first as a compowid of 
M>e rolume carbomc oxiile, and one volume hydrogen gas 
mluced into one volume; but a Mibsetpient and more (wreful 
esamtiiation of it satisfied mo that it was a mere mixture of 
ourbonie oitde and azotic gas. 1 found its specific grari^ 
(^9736, and when analysed it proved a mixture of about 
8 voluroen carbonic oxide, 
1 volume aiotic gas. 
I found tliat by means of sulpbnric acid, collecting tlie gaa 
evolvi*d, dett'rininin)r the quitnliiy nf iron separated, and the 
we^hl of sulpliate of potji^h fonnwl, ferrojiruiwiate of pota«b 
might be analysed with tolerable accuracy. For by tliis pro- 
ce* (nnd e>itimating the water driven off by heat), I obliunrd 
from 100 graiiw of the salt. 

Potash 43-18 = Potassium . . 36 

Iron . , . 13-0 1 
Cyunugen . . 37-49 
Wutcr . . la-OO 



t*^ L The true constituents are, 

.' Potassium . . . 37*658 

Iron . . . . 13-145 

Cyan<^n . . . 36-621 

Water .... 12-676 


I found reason to conclude that the decomposition conducted 
in this way took place as follows : Let us suppose 106*5 grains 
of ferroprussiate mixed with sulphuric acid and heated. Tlie 
constituents of the salt are the following : 

6 atoms potassium . . 40 

4 atoms iron ... 14 

12 atoms cyanogen . . 39 

12atomswater . . . 13*5 


160 grains of pure sulphuric acid, or 198 gr^s of the add of 
commerce, were required to produce complete decomposition. 
But I always employed about twice that quantity. 

One-fourth of the cyanogen passed over undecomposed along 
with the gases. The remaining cyanogen was composed of 
16 atoms carbon, 
8 atoms azote. 
2 atoms of azote went to the formation of ammonia, for the pn^ 
duction of which 6 atoms of water were doubtless decompooed. 
The 6 atoms of oxygen of this water, tt^ether with 10 atom 
of oxygen from sulphuric acid, converted the 16 atoms of car- 
bon into carbonic oxide, and the 6 atoiAs of azote renuuning 
passed over with the carbonic oxide, making a mixture of 
16 volumes carbonic oxide, 
6 volumes azotic gas. 
Twelve more atoms of the oxygen of the sulphuric add must 
have gone to oxidize the potassium and the iron. And 8 
atoms of sulphuric acid went to saturate the potash and 2 to 
saturate the ammonia. 

Berzelius has shown by analysis that the salt usually distin- 
guished by the name of ferroprussiate of barytes (which will 
be described in a subsequent part of this volume), is a com- 
pound of 

2 atoms cyanodide of barium, 
1 atom cyanodide of iron. 


I Mr. Porrett firnt p<»inU><l out a methorf of ohuiining a peculiar 
from this suit. His jtrocesM v»s iw foUou*)! : 
Dissolve the suit in colil water, aiid f»r ovi-ry ton gmins of 
it ndd 3'53 grains of real sulphuric aciti, agitate the mixture, 
ud set it aside fur some time. 'Die whole of the ))tiryles and 
■olpburic and precipitate in combination, and leave the acid 
diMolved in the water." ThJit avid pofisosaes the following 

It hw B pale lemon-yellow colour, and U destitute of smell. "'''I**^ 
It is decomposed by a gentle beat or liy oxpo»tire to a strong 
tigbu Hydrocyanic acid is tlicn formed, and white prussiate 
of iron, which by exposure to tJie air quickly becomes blue. 
When combined with the salifiable bates it forms the wdtn for- 
merly called triple prussiates. It displaces acetic acid from its 
flanbinalions wiiliout the asiustance of heat, and forms triple 
proMuiiM with the bines pre^■ioluly united to that acid. It 
•zpels all aci<U from soluble eombinutions when it is capable 
of formtt^ itnoluble salM with tlic bEues to which they were 

That tliiK IK a peculiar acid, is farther proved by what hap- 
pen* when a solution of triple prus«iiate of Mida i* exposed to 
llie action of the galvanic battery. Its acid (including tliviron) 
WH deposited at the positive pole, where, in consequence pro- 
bably of tbe dcpomposition of water, hydrocyanic acid was 
Tohtilucd, and blue prussiate of iron deposited. 

Mr. Porrett has pointed out an ingenious process for obtain- 
Hdng this add in the atate of crj-slals. It Ls as foltou-M : Dissolve 
^B8 gnuns of crystallized tartaric acid in aleuhol, and 50 gntins 
Hof (erropntMJate of potash in as little warm water m po«i^ibIc. 
^^Jix tile two liquiiU. Hitartrate of polii^h U precipitJited, and 
the new acid remains in solution. Hy iipontiuicuus crystallisa- 
tion it seimrates in small yellow coloured cubes. I liave repeated 
this cxpi'rimcnt with success. Ttie cryHtals of the acid arc 
•ooo destroyed when left expowil to the action of light. They 
become cueted with pnusinii blue and lose their regular sliape. 
llie Munc change look placid even when the acid was kejit in 
« pTvn excluded from the light by a wooden door, which, how- 
r»er, was very often opened. 

The analysis of this acid would be attended tvitli peculiar 
difficult)' on account of the ease with wbicb it undergoes decom- 
position. Dul there is iw dilficulty in dixlucing its constitution 

Pha. Tnns. 1814, p. MO. f Portett, Phn. Tntnt. ISU, p.630. 


ciup. 1. trom die plienomena of its formation. FeiroprussiRte o£ barium 
(abstracdng the water) is a compound of 

Q atoms cyanodide of barium, 
1 atom cyanodide of iron. 
When the barium is thrown down by sulphuric acid it is in the 
state of bai^tes. It must, therefore, have united to two atoms 
of oxygen obtained from the decomposidon of water, the two 
atoms of hydrogen of which must have combined to the other 
constituents of the salt. The new acid, therefore, must con- 
sist of 
casporiuoii. 2 atoms hydrogen . . . 0*25 

3 atoms cyanogen . . . 9*75 
1 atom iron . . . 3*5 


Gay-Lussac,* who first pointed out that view of its constitation, 
considers it as a compound of 2 atoms of hydrogen, with a 
radical, to which be has given the name of cytmofer, and which 
he considers as a compound of 

1 atom iron . . . 3*6 

3 atoms cyanogen . . . 9-75 


It might, if it could be obtained in a separate state, be called 
a tercyanodide of iron. 

Supposing the constitution of this add to be, as Gay-Lusaae 
conceives it, we may distinguish it by the name of hydrofiim^ 
cyanic acid. But I think it conceivable that it may be nothing 
else than a solution of 1 atom of cyanodide of iron in 2 atoms 
of hydrocyanic acid. 


hmott This is the name by which M . P. Boullay has distinguished 

the charry matter, formed by the spontaneous decomposition itf 

rrottnin. It b insoluble in water and alcohol, both cold and hot. It 
dissolves in concentrated nitric acid, to which it communicates 
an aurora red colour. The solution is rendered muddy by 

It dissolves with great facility in alkaline leys and in liquid 
ammonia. The solutions are similar to those of ulmate of 

• Ann, de Chim. et tie Phys, xxii, 380; xniv. 884, 




|Ki(a»)it but a gootl deal inur« red. Acids iiro«ii>itatc a very 
light l>rawMi»ii-r«<l |>owd«r, wliidi when dried has no brilliancy, 
and rrtwnililM lit colour vliiiui ink, Tlie metallic salts pnulucc 
brunti prrcipit«t<.% and L'nni pint vly deprive iLc liquid of eidoiir. 
A^Hico bt-jit ui iipplii-d Rzulroic acid is completely decomposed 
into hydrocyanale of ammonia wliidi !>tiblim<^H ; and wlien th« 
trmppralure is still &nber elevated a combuAtiblc gwt is obtain- 
ed, wbicb burnt) witli a blue colour, and wliicli luut tlie odour of 
cywnof^n. Wlml remains is diaroml. 

M. lloullay ha endeavoured to determine tlie compoiulion 
of this acid by aiuilyntti. He ilcvomposi^d it twice, ;iiid found 
the ratio of tlie volumes of axotic gas mid carbutiiv iieid gan 'i 
to 5. Hence be has concluded that it is a compound of 

R3 atoms axotc . . . 9-5 

5 atonu carbon . . . 3*75 
I atom hydro^n . . . 0-125 
would make its atomic weight 7-373. 
Boullay a^nures us iliat when piitash is digested with glue 
a<)(UUitityofa]cul[nicacidiafonnc<l, justasulmicacidis formed 
wl)i!!n Kugar of grapeti is dii^csted mth the same base. This 
WW the reanon why ho gave tike acid tJic name of fuutmie, 
otnuiiiig proltably ulmic acid containing azote.* 

I have Ih>vu tn<luce4l to notice tlie opiuioat of Roullay on 
this subject, though be has not 8uci»-eded in denionittrating 
them by satisfactory eiKperimcnUt, betuuHC I consider the sub- 
ject as well entitled to the attention of chemists. Doubtless 
tnany other combinations aud modificatiotts of cyanogt-n remain 
iitill unknown, and reatly to recompense tlie future labours of 
U)e iiiduvtrioua chemist. 

■ vn. 


CLASS vn. 


^^ Uie u 

^B The knowledge of tlie acid properties of the compounds, inMotr. 
vhieh sulphur fomut witli ibc ncidifiahle bases, Ls a recent 
•ojuiution to rhemistry, and for the fiunn at present known, 
w« nrr chiefly indebted to nn ela{>orale and excellent ]>a])er on 
Mulphur nalt*, by Herxelios, in the Memoirs of the Stockholm 

• Ann. Je Oiiai. et dc Phji. xliii. t»S- 

356 Sli'LPHUE AaDS. 

o-^*- Academy of Sdencea for 1625 (p. 282) and 1726 (p. 68). In 
that paper he has shown that most of the acidifiaUe bases hare 
the property of combining with sulphur and ooostitntin^ addM, 
while the alkalifiable bases when combined with aolphnr an 
conrerted into alkaline bodies. The sulphur alkalies have the 
property of unitiog with the sulphur acids and of forming aalla^ 
a great number of which hare been examined and described io 
the paper just referred to. In geoeral when a sulphur acid is 
placed in contact with an oxygen base, decomposition lakes 
place ; so that sulphur acids can combtoe only with sulphur 
bases. For example, wliat was formerly considered as hydro- 
sulphuret of pota;^, is not a compound of sulphuretted hydn^ 
gen with potash, but with mlphuret of poUigsiwn. The potas- 
sium exists in the solution, not in the state of an oxide> but ot 
a metal, and it is kept ia that state by being combined with 
sulphur. The salt, therefore, is a compound of 

1 atom sulphuretted hydrt^en . . S-125 
1 atom sulphuret of potassium . . 7 


BO that its atomic weight, abstracting the water of crystalliisp 
tion, is 9*23. 

I hare already, in the first volume of this work, given an 
account of all the known compounds of sulphur and the acidi- 
fiable and alkalifiable bases. Nothing, therefore, remains to be 
done except to give a list of tke xtilphur acids. 

In a note in page 313 of the first rolume of this vodc, I 
mentioned that I meant to call all the acid compounds of sut 
phur and a base by the name of sulphides, while to the alkaline 
compounds of sulphur and a base, the old name sulphureta irill 
be confined. It is convenient (indeed necessary) to hare a 
means of distinguishing the acid compounds of sulphur from 
the alkaline, and sulphide has been chosen as analogous to 
oxide, chloride, bromide, iodide. The following table exhibits 
a list of the sulphur acids with which we are at present 
acquainted, together with the old names by which they were 
formerly distinguished, and which indeed have been most cunt* 
monly applied to them in the first volume of this work. 

New Names. Old Names. 

i^'iSt 1- Sulphide of hydrogen, Sulphuretted hydrogen. 

2. Bisulphide of carbon, Bbulphuret of carbon. 

3. Sulphide of phosphorus, Sulphuret of phosphorus. 


I. Sulpbidc of anoni);, 
ScMjuisalpliuIe of ancDie, 
Persuli>liuie of amenic, 
Sul|i)(iiU' o( Mlurium, 
Se«)uuulpliM« of aiitj- 

is. BiMil|tlii(!c of antimony, 
D. Ppriul|jhi(l« of uniiinoiiy, 
1. Trrnuljihide of lun^lcn, 
B. Tcniulpliide of molybde- 

Qialeniilphid« of molyb- 
4. Stitpliidf of eiiromiiim ? 

15. Sulpliide of columbium, 

16, Ouulphide of tin, 
'. Probably the tiulpIiidM of tlie noble metals. 



Pentiil|))iiirot of am>nic. 
}>ulj>liiiri'i, (if (i-IIiiriiini, 
Sulphurct of uDticioDy. 

Bisulphuret of mitiinoiiy. 
Peruilphtiret of antimony, 
T«TSulpb»rvt of tungsten. 
T«i«ulphur«t of rootybdenom. 

Quat«rKilpliiu«t of ntolybd«- 

Sulpfauret of chromium. 
Sulpbarct of columbium. 
MoMiic ^Id. 


The talla into vhidi tbe»c diffcrenl sulphur adds enter wiU 
ipy oDt MtentioD in a Rubsequent part of this volume. 

^M Afl for tb« Bth and Otb d»«MM of acidH, the selenium adds 
^^■d ullurium afidfi. thr nnireity of selenium and tollurium K.1A 
^pbberto pti^cludt-ti tbe [XWAibility of investigating them. Each 
of tbese bodice nniira with hydrogen, and forms vith it a com- 
pound having arid properties, namely, telenktuA hydrogen, and 
I tdbtntUil hydrogen. But even the tuiltH which tlie«e two actdx 
bm liRve been bat iiiiper6cfailly examined. Hen, thi-n, In 
' the pnramtitBta of oar knowledge, muHt tenninal« our account 
uf the addfl. 

RllH*^" conmt of tho simptc bodice described in the third 
>r of tbe first vuliunc of this work, under the name of 
■iiyfr tUltal^tibU fxuet,* united citlier to oxygen, chlorine, 
btoodar, iwlini-, and fluorine, sulphur, selenium, &c. There 
tn, therefore, aa many claiaea of alkalies as there are of acids. 

' * SotcmI of die idififable hiut* have alto the profxvt; orfbiming nlknlica, 

•hai nalMd to ■ «imI1 qiuntiij of oxygen, and pcriufX also of ibc other 

CHAP. 11. 





Ctup II. 

gimple fxiffn, thon* in an nlkali compoa^ of two acidifiable base* 
joined tnjfctlicr, namely ammonia, which is K coiii|i<i»ti(I «f awHe 
and hjdrogen. These two lM(Ui'» are ttolii clfctm-iKi^iriro, «t i 
is the case witli the alkaline ba«i>8; wc need not then-fore l>tfl 
surprlsod uC tlicir constituting an allcati when comSineil. Yet 
■t present we arc not aeqiiainte<l with any two other ^leetrcH 
positive bodies which constitute an alkali. But there are aboirt 
SO oompoaud vegetahle bodiex which poasess alkaline proper- 
tiea, consisting prot>abIy of (.Nirhoii, hydrogen, nzole, and a little 
oxygen united togetlier, Thei^e may he called C(im|K>und or 
complex alkidiiic bodies, in cuntnuliAtinctiou to the iiIkaliM 
with simple bases. Though only 20 are knou'n at preseDt. tlMre 
cannot he a douht that as the knowledge of the vegetable kif»g- 
doin increases the number will greatly augment, and will pr<>- 
bably bear some ratio to the oxygen acids witli compound 
bases, which at present amount to 57. 

Having described the [iroperiieH of all the known alknlict 
with simple b&gn in the first \-o1»me of lliis work, I shall satisJy 
myself here with ^ving a table of tlie oxygen aikaiiea with a 
simple base. 


•"'■"»- 1. Potash, 

2. Sodm " 

3. Lithio, 

4. Buryti"*, 

5. Strontian, 

6. Lime, 

7. Magnesia, 
6. Alumina, 
9, Glucina, 

10. Ytlria, 

11. Protoxide of cerium, 

12. Peroxide of cerium, 

13. Zireonia, 

14. ThoHiia, 
1 6. Protoxide of iron, 

16. Peroxide of iron, 

17. Protoxide of mtuiganese^ 
16. Sosquoxide of manganese, 

19. Protoxide of nickel, 

20. Protoxide of cobalt, 

21. Oxide of zinc, 

22. Oxide of cadmium, 

23. Protoxide of lead, 

24. i'rotoxide of tin, 

25. Peroxide of tin, 

26. Oxide of I>i«mMtli, 

27. Suboxide of copper, 

28. Oxide of coppei^i 
29- Suboxide of mercury, 
30. Oxide of mercury, 
81. Oxido ofniren 

32. Oxide of arsenic? 

33. Protoxide of untimony, 

34. Oxide of tellurium, 
S.*!. Oxi<le of elirominm, 

36. Protoxi^le of uranium, 

37. Peroxide of nrnnium, 
3A l*rotoxideofmoIyb<Ienuti», 

39. Dentoxide of molybde- 


40. Protoxide of tungsten, 

41. Deutoxide of tuttg^lcti, 

42. Oxide of titanium, 

43. Oxide of columbium. 



U tB nmuwensry to giv« n (ablu of Ui« chlorine, bromine, ^^*f- "- 
Itc. aUodioft. whli m >Amp\* baw, t>tf<aiwir tin')- urc the xuine u 
tha. preoe^iiii;, MibntilulinK' tlie terms <.-Kli>ri(li>s, bromuk-s, 
ladidcflk iu]|iliuroln, Mrlciiicls, tnllurebi, riw|H?cuvcly, iiiHteiiii of 

< Ammuiiui limy perli^iM ;kJjv> lie c(inHi(l<^<-ii a» nii alkali u-itli 
k ainplc Imim.% U' we cunMiIrr nrw/c ax (liiil bitv;, wiil liyilruguii 
M 1^ elcctrvpoHtivf body with wbidi it ia in cumbiiifttiun. It 
tsigkt, irarUaiMiiaaMW|eiewanled)be<ienofDiiatedaterA^rari!e 
ijfucote, ■ '.I. It:, .1 .>.'.' ' , .1 

Tbr fuliowins; table (-xIiibitM tlio iiain«:< luid die compcHiUflii 
UiK 'JO cowjilex HlkiilJRv bodlvs, so fiir u& Uiey luurwbwea 



. .10 . 
. 40 . 

9 . 
4 . 




. 'ii, . 

2 . 



. 30 . 

3 . 



. 34 ,.. 
. 24 . 

1 . 




. 40 . 

2 .' 



. 10 . 

1 . 



. a . 

1 . 



Nil9*cte<l to uualyaik, 

ConjtHtnent^ in ahniM. 

!, 1. Quiniti 

2. Ciiicbiiiiin 

8. Briicia 
■L Strycliniii 

. &, Veratrin 

6. Emeiin 
,i7. IttiliaTiitk 

6. MtirpLiu 

9, N«rculin 

.JO. Cikfr<-iii 

■ 11. Di-igiliitiiii 

13. Picrotoxiu . jv 

14. D«|Jiiiiii 
1&, DifpisJtu 
16. BtilUdoDin 

,,17. Al/opjii 
. la. J«lappiii 
JO. Smilacia 
.30. Rlicin. 
At tuae of tliese compound ulkaliea has hilbcito b<.'(.>ii intro- 
into HimtiKlry «■ a reagent, I coaceirc tliat it will bo 
itWr )w>t l« ilfMiribc them here, but to delay tUe account of 
km till wv come to tri'^it of tlie vi'^vUible kin^lom. This 
II Jwvc more Hjiacv for on account of tliv salts — a clawi of 
nkUm which coiisdtute pcrliajis tin- moit iioporuuil department 
' elemejitary chemiitjy, 
Tbe alkuUes composed of the electro-positive bodies uniU'd 



NEUTKAL courousns. 

ch•^Ill. to chlorine, bromine, Eodioe, sulphur, Gelenium, &p,, h«Te 
already been described, so far aa they are known, in the fint 
volume of tlib> work — and tho talta which they form with their 
respective acidi will eome under our review hereafter. I nwy 
here close this cliapter tliat we miiy <iit«r upon an cxuniiatioa 
of the neutral compounds, which will occupy our nttcntion tn, 
the next ch^ter. 



I MIOBT in tbi§ chapter describe a oonHiderable proportion 
th« wgetahic and animal principloM ; for many of the 
iinportunt of tliese principles neitlicr poMtew the eharacten of 
acidv or alkalies, at leant so far as hitherto obsen'cd. But I 
shall confine myKolf in this place to those principles which are 
useful as chemical rea^ntfl, and which tlierefore it is of import* 
ance for the student to be floqiiniiitod witli before he tunut hia 
attention to vegetable or animal cliemi*try. These neiitnJ 
RuKstaoces tmtnmlly arrange tlicmselvitt muter w-ven different 
heads. I shull, therefore, divide thb cbaptcr into the scvea , 
following sections : 

1. Water, 5. Voktil« oils, 

'2. Spirits, 6. Fixed oUa, 

ti. Ether, 7. Bitumens. 



I have already, in the first volume of this work (p. 10.^ 
described the physical properties of water, imd pireu an accou 
of its composition. It remains only in this place to make a 
few observations upon it as a chemioU body. 

1. It has the property of dissolving and combining wilk 
almoKt all tlie adds, and with seieml of the aHcafioe bo(be« ; and 
tf it mIiows an equal (liKpONition to combhe with either, aat 
does not destroy nor conceal their acid and alkaline quidlttea^ 
it is obvious that it is a neutral body. It has the property nl«o 
of dissoMng a consiilerable number of the salto, whicli an 
compound of an acid and a base. The quantity of each irf 
these bodies which u'ater am dissolve has a limit, and it itt very 
various n-ith res]>ect to different salts. When lliv water has 




diMolred aa much i>f any suit as it can take upi wc say Iliat it < 
b satttnUed witli the aaiL It we add more of the Bolt after it ~~ 
b thtn MttirateH, it wilt remain at the botioin of tlie Hfjiiicl 
■wJJMolypd. Or if wc cauM' it tu ilitAulvi; by illvr(■IL^ill){ llio 
U-mfioraturo of lh« water, it is ajfuiii dupotiitecl in crystals when 
the li(|uid is allowed to cool. 

It IB ul>viou« that the power which thus limits tlie solvent 
prapw^ of water is the attraction which exists between the 
patthHM of the salt. When a salt is di»solred in water ita 
porticleB muftt he equally dtsfiersed tbrodgli every part of the 
Bqiud. They mast of course )><• iirrniiKcd in rogtiliir mnk and 
Shi, and the gfreatcr tlic quantity dissolved the snuillrr tntttt 
the dbtnnm bo b<>tweon every two particles of the salL It 
would Appear that the greater the number of particlcH of suit 
wkkb arc dissolved by the water, the smaller is the force hy 
irftkh Hub mil and water are united.* 

This may he understoo<l by considering tlic particle of tall *'""^,"' 

I to he surrounded hy iiccrbiin number of pcirticlos of wnlori each 
ft which is attraeteii tu it, and the aggregate attractions of wltich 
Irill rttprrsont the force, by meatia of wliich the particle of ludt 
b kept suajirniled in the liquid. Thiis at the temperature of 
BB**3A| 100 parts of water are capable of diwolvin^ 7-74part8 
if aoliydrons carbonate of aoda. The atomic weight of tinhy- 
droiu aubooate of soda bein^ 6-75, and that of water l*13i>. 
It is obvious that every intej^ant particle of the salt must ho 
ttaitad to about 6tt integrant iiarticle!* of water. We may con- 
•ider every particle of the salt as GurrotLnded by ti8 particle* of 
', each of which attracts it to itself by a certjiiii unknown 
; M tliat the whole liquid may be couiiiderc<l as compowd 
^ ■nail splieres, each of which has a particle of salt in the 
^^prntre, while tiie rest of the sphere is composed of 88 particles 
^pif wati^. Let us 8up{>0M.> now ihat by meaiui of heat we can 
raaiilr the lOlt [mrln of water to dbtHolve an aiMitional 7*74 
pafta of ludiydroiis salt. It is clear tliat the comi)ouud will now 
kimIsI of 1 atom salt united to only 44 atoms water ; the num- 
bw of alOBH of water united to the uUim of »alt will now be 
to one-half the former number. The spheres will 
anuller, and consequently the particles of salt nearer each 
than in tlie former ease. When tlie solution cools the 
lea of Rolt Mug combined with only half the atoms of 
T, and bi-inji; nearer each otlicr, a certain number of them 

KtT Ihi upfflnMiiM related with Mother ohjcct in view, in iny tresliw 


ciu»n>- iinit« nnd form crystals, vhich in consequence of tlicirwei^bt^ 
' arc G:Tii(tuiilty dqioflUed at Uie bottom of Oie liquUI. ' '■' 'Hmi 

What increases thn teitclDtiey to c-rytttxlliz*^ is 'ti"! ^Iw" 
forinKl vt not iiiihydroiiM, hnl n combination of I <it«im of salt 
And 10 iitom^ Mi)tcr. It would appear that the comb inatioo 
between these 10 atonni and tlie atom of nait is more hititnate 
than that which sabaista between the wit an«l tlie water in 
which it is difiHolved. For when it combines willi the sail 90 
as to con.ititute a crj-Ntnl, it fpves DUl the 144)'*of b<>Ht wkidi 
eonstitulc tlie lutcnt heat of wstcr. Suppose tlic solniiim thai it 
mndcbyhcat tobciinagB[rcg«tc of IO:(phoric1e8,con>(ii^tingMKli 
of I atom of uiihydrouH salt surrounded by 44 atoins of wsMT. 
When the solution cook, 9 sitamft of tlie salt uniting with 00 fl 
atoms of n'utcT trill cryAlidlive, iind tlierc will r^raain 7 atotu 
of Kult and 704 — 90 = 614 atom:* wntur, which will oouMti- 
tutc very nearly the »atumtcd solution, consisting of 1 iitomfl 
mU enclosed in S8 atoms water. But the reader will form « ~ 
better idea of what really takes place iti snch cases, if we refer 

[to a real experiment, I dktolred 4C0 ^r»in<< of anhydrous 
carbonate of ^odn in S025-() grains of hot wnter, aixl fiuiling 
the .solution Into n well stopped phiul, set it imde till it c<iol4<d. 

' 'TIk' solution remained quite liqnid at the lempenituri- of ftO* ; 
but upon dmwing tlie cork n quantity of cryMids fe)), and tint 
temperature rose to 64". The crystnls weired ()2&4 gmfaa, 

[ eqni\'alentto l*2;i-13gta>tis of anhydrous sail. Now the HlotHlc 
equivalents for these weiglits arc as follows. 'Hie hot solution 

|"wns a com])oiind of 71*!i atoms anhydrous salt, and IMO-5 

^Ktoms of water. The crj'stals depo<i)ted consisted of 1^34 
^Onis salt, in combination with 1 S'i'4 at(ni» WBter. ()f counte 
there rcnuiined in solution 52'87 atoms of tuihydruntt ^idt cotft- 
bincd n'itli IG18'1 atoms of ntitcr. 

The hot solution consisted of a congeries of sphericW 
fiisting each of an atom of anhydrous salt, surroimiled by i 
iltomn of Wi>l«T. About Jth of the anhyilroux sidl wiw dejiotkaj 
in crystftls when tlie cork wast drawn, envh uUim of which «r- 
ried along uith it HI atoms of water. So that there remained 
a solution consisting of spherielcs, in the centre of each of wbicli 
b an atom of salt surroiimled by 3U atoms of Kuler, wliidi; 
represents the solubility of the salt at 64^ 

Water not only tHtiKilrfs many suits and other liodi^ ; but 
it has tlie pnjperty of entering into oombinaUiin with n great 
many bodies in n solid state, constituting ctrnqmunds to 
which the name of AffttratfS was given by Proust; and ibis 

•n con-H 





Ft tJtoufi;k in Nome rvepecU exccp>ioiiabl«, bax boon univer- 
[tdly adopted by chemi&ts. I'hcre are few or none of the simple 
. wlikh are ca|>ublc of forming Iiydntes with water, Tlie 
;>|Mrl(!n of combustion are Mjlublc in it to a trifling extent ; 
ibu name iviuitrk ii|i|iti4^s to liyilro^t^ii aixi azale ; but none 
rtJteotiMTTiwM-iitU'liciburuciil or »lkuliue,iir« capable of uniting 
rith it, MoHt of tbe acicU iirv o<iptJ)li; of fonninj; hyilraU*, 
^asli bydrutcs lurc usually l-uUlsI cri/*faU <ff Ibc mid ; Moino 
they are in (lici<tut£of powtlont; or M>niL'limux tJit'y von- 
jeUies. Most of the alkaline bases in like manner 
t«caii«ucut« hydrateiii, iwnie of them in crystals; but a much 
, p«ater {irupoitjun lu iht: »tate of ilry pouxlers. I bavc ulreiuly 
the preccdii^ |t»rt of (hiA wo>k given an account of all of 
liihoK hytLmUM h)lb<>rto oxamiued. No fiuther observationg, 
afore) Hflm requieito here. 



The term anUtU spirit* in tJiia country^ is usually applied to 
pthe lic[ui<) obiiiined by iJi«tiUatioti from different fermented 
(Uquom ; all uf wbicb, us luw been long known, are nothing eW 
j,Uuui idcobul mure or Uiw diluU'd witli water, and flavoured by 
of »omo volutile oil or utln-r. But of latv yearn two dis- 
speciea of li<jnid have been <li»eov<-icd, biutring a much tftum. 
n rwemblanoe to alcobol than to any otlii-r body whatever, 
^jhouifh at the same time u> dilTerent, (hat they must be con- 
inwlerul opiirt. Tk^^e are fii/nMic.ttk and jjyrojyiic gpirits. I 
|«li«ll therefore ttuUliviilt! tliijt m-otioii into three ]>art»; in ihu 
a( wLidi I will f^ive lui lu-'omnt uf alenbol, in the M.>coiid of 
pyriMMKCic spirit, ainl in ihu tliird of pyroxyUc spirit 

I. AlmhoL 

I-'«nnented liquors arc of two kinds. They either conaiBtof"M«T> 

hahoexpretaedjuieesof voriouN kinds offruii, as grapes, currants, 

^applem &c< The»ie juices wben fermented, are known by the 

of tpuM. Or lltey eonitist of tbe hot iufa<«ion of various 

Ikiaib of corn, us barley, rye, rice, wheaU &e. Those Infusions, 

I vhvil f«rniente«l, are known by the name^ of btrr aiul ale. 

Both of these kUidfi of li<)uors were knoni) nt a rory early 

period. The .Vripturc informs tis that NoaJi planted a vinc- 

lijnuil aud dnmk winr : and the heathen writent ure uiumimous 

tn ascribing tJio invention of this liquor to their onrliost kings 

and herocH. Deer, too, seems to have been diseoven'tl at a 

Tery remote period. It n-as in common use in Eg)-pl duruig 




[OM^ia tlie diDo of Herodotu§.* TWttus infiinns ua that it was the 
drink uf Uie Gcmiai)8.f Whether thi>tit)dciitN bad any method 
of procuriag anl«<nt HpiriU Irom tbese w any other liquors does 
not apjiear. Tlie ( ireelw and Itomaiis seem to Iiiivc lnH-n tgiUH 
mtit uf ardent »]>iriu idtntrclhcr, at least we can discover no 
tJUVCH of any ttucli liquor in tlieir writinf(fi : but among the 
Dorthcra nntioiut uf Europe^ intoxicating liquora were In use 
from thr wirii<'st afres. Wlieibcr these liquors lesembled the 
beer of tlic Ciormaas we do not know. 

At what period these liquon were first sabjecAcd to distiUa- 
doo is unknown ; titougli it can scarcely have [>rcc«ded the 
time of the ali^hymku. 'I'bv proiMii* is simpleu Nothing more 
is absolutely necessary than to boil tliem in a still. The finil 
portion of wliat cocnea over is ardent tpirila. It is cettain. at 
least, tlial the melliud of procuring ardent spirit» by diMiUatioB 
was knotifn in the ilurk »g«s; and it is morv titan prolnable that 
it was practised in the north of Europe mudi earlier- 'I'bey ' 
ore meudooeil expressly by 1'haddssus, VUlanovanua, and H 
Lully-t ^ 

It is by tlie distillation of fermented liquora that ardent 
spirits are obtained ; and tliey r«ceire variints names aocordiag 
to the nature of tlie subi^tuncti eta{>loycd. Thus brandy is pro- 
cured from wine, rum from ilio fermented juiee of the Migar" 
ciiuv, whitky and gin from the fermented infuiuoii of malt or 
grain. Now ardent a])irits, whatever be their name, consist 
almost entirely of three ingredients : veimc\y; watery pure xpiril 
or alc-ohol, niid a little oil or retiHy to which they owe th«ir^M 
flavour and colour. ^^ 

BKUAaiieo. 1. When these spirituou« liquors ak rcdt»tilled, tite first 
portion that comes over is a line light tnul^«parl■^t liquid, known 
io c«mmereo hy the name of rttlijitil tpiritv, niul coniniooly 
•old under the denojniualion of ulcoliol or ^irit of wine. It 
HjIWt, however, as ftlrong as possible, still containing a con- 
riifexablv purtiun of u-utcr. 

The method usually practised to get rid of this water ia 
mix the spirita with a quantity of very dry and warm aaU 
tartar.^ This sttlt has a strong attraction for water, and the 
greatest part of it is insoluble in alcohol. It accordingly com- 
bines with the water of the spirit; and the solution thus formed 
nks to the bottom of tlie vessel, ami the alcohol, which is 
lighter, swims over it, and may easily he <locunti.-d otT; or, wliot 

• Lib. ii. [). 77. t I>e Morib. Oenn. ch. ssU. 

I Berginnn, ir. an. W. \. $ Impure (Stboaste of fietasfa. 




k {>rrhnp« better, the Bolution of pobwli may be A<niwn off from ^^ <■■ I 

■elow it b)' mf*m of a Mupcock placed at the battom of the ] 

■MteL* The aJcohol, thus obtained, vHen oinlainit a little potaah J 

bbnlvH, which may be sejiaraled br Hislilling il in a n-nter J 

■Bth. Tlip Rfitril pikMCH over, and leaves the potash behind. ^H 

■I is |itopcr not to dlHtit to dryiieM). This process is first m«n- ^^M 

EAmimI hj Lully. The Uqtiid procured by means of it has been ^^M 

Wtunlly dnting^uished by the name of utcoAoL ^^M 

I Alcohol is said to have been first accurately described by ^^ 

lAmold de Villa Novo, who was bom ahotit Ote end of the 1 

Miirteenib century. 'ITiis clieniivi, wlto W!w professor of medi- ^M 

Mine ut Montpeli«r, first formed tinctures, und iiitnxluced them ^H 

feto medidiie.t ' ^^M 

m llw ipccifie ^vtty offipirits, as highly rectified a-< poMlhIc ^^M 

py npeatnl dLililtalions, seein<i to lie about 0*8*20. at tlie tern- ^^M 

linmture of W ; but the alctJiol of cofomerce, which is nothing ^H 

Use titan redifiod ^piritti, '» HcMnm under '6t)7l. Ky means ^^M 

nf mlt of tartar Mu>ichenbrO€ck brought it as low a« -SI 5; hut, ^H 

pi ^eoenl, tlie alcohol concentrated by that procetK is not tmder ^^M 

■ML owing to the weaknesa of the spirits employed. Even at ^^M 

^^Ppccilic gravity -HllV tlie alcohol iit by do means pure, still ^^M 

Eontnining n consi<Ieral)le portion of water. Dr. Dlack, by ^^H 

Hi^MDlcd distillations off miu-iatc of lime, nbiained it as tow as ^^H 

MOOt bnt it was I.owitz of Petcrshnrgb who lint hit u[)on a . ^^M 

WfmOkvA ofobteining alcohol in a state of iibsoUile purity, or at ^^ 

BbbA wry nearly so. His process n-as published in I706;{ 1 
bnd tlte aame year Itichter made known another, by which the 
kme purifinition wan iicei>mpti«hi>t with ^till grciiter fitcllity.f 
^^The proeewof l.owiuisuK follows: Take a quantity of fixed iJSJ^',^^ 
^Hllo perfectly dry, ajw) Mill warm, and nearly till with it u "^ '""- 
HHk. I'pon this pour such a quantity of alcohol (previously 
larov^ht to -8*2 1 by means of Kilt of tartar) as can be absorbed 
by the alkali compleleiy, so that the whole shall have the appear- 
huDtt of II solid mass witliout any alcohol swimming above. In 
ifmcnl, the portion ought to be two parts alkali and one part 
Ulcobol. Allow iJiis mixture to remain for 24 hours, and then 

E^* Sea lUs pracvs* ikscribod by HoAloan an oew, in bi> Otucrtuioiic*. 

bk]r«..CMiii. 8«l«et. p. 30, puhlisli«cl In ITn. 

I t He I* said "Iso to have been ilw rimt wlio obtained the ml oT tarpcn- 

I liDa. Ho pracorad il hy dixtilUng turiieiitint!, and ctDplojDd It u ■ loltent 

I tf raihis. I bsTt not bfva able to find tuj tracni of those diacovtruM in 

I my of lh« mcU of Arnold ibat I faavo louhtJ iliruu^i. 

I t Creb** AiwdIs. I7M, i. 105. § Iliiii. il. SI 1. 

I It prannae b the Kate of carbonate. 


f*^ '"■ distil by ft lieot so modHrnte. tliAt about Iwo gf ooiidg i<lm^ 
between tl»e fitllin^ of the drops of alcohol from tlie beak of 
div receiver. W'lieii tliU inberval inore&sea, the receivei muat 
be diaiii^ ; for il i« a nijrn tttnt all ibe strong alcohol lta« come 
*nT. W'lifit comes over utxl is weaker. Uy iJii» jirucisM 
Lowitx (d>tain«d olcobol ^^ '''^ spccifie gravity 0-7dl at tUe 
tsmpunlure of 6dV<' ■■—i 

Winn Kicbtcr repeated the exporinieiit uf lA'vllXy lio n'dtKwd 

' '4lie' alcohol to the n|ifciiic gnivity 0-7 !>'i at ihe leiii[>eruture of 

68^, but (.-ohUI not briti); it any lower. He fouud, upon trial, 

'that the follDW-iiiif method, wlik-h ii> much more expeditJou.*, 

I ansuered equally well wiili tliuXut [.owiu: he ex(Hxied a (juaii- 
tity of tlie Hall called eldoride of caldum to a red hvat, reduced 
it to pou-der, and iiilroiiuix-d il vrbtle yet trurm into a rotort, 
and jioured o%-it it iit iitUTvaU u qiuuility of alcohol, of 0-&H, 
ticarly equal to it in w«-iglit. A vtolvut heat wa» produced. 
The retort wu put ujion a mid-hatli, a receiver adjusted* and 
■the IJquiil nadv to hoiL Thv liolt vnu diMwlved, and formed 

hwilh llio alcohol u thick solution. The portion ihat had piuwd 
lOvrr into tlie n^civer woa nuw poured back) find ibedislillatioii 

■was continued till un«-luilf of the alcohol ctunc over into the 
receiver. The receiver inuNt now be changed, iu>d the dJjttiJ- 
lalion contintieil; boouuse what vouKi* over next is weaker. 
'I'he fir»t portion of alcohol tliu« obtained vas of the specifier 
gravity 0-7^'2, at the temperature of Qt^, 

M. PujotdesCharmes has 8ug^et>ted another mode of rectify 
ing HpiritB, founded upon ijie property which delitjuv^ccnt iiall% 
aA chloride of calcium, cldoride uf ma)igane§>e, &c. have of 
ah«oriiiu^ thu vapour of water, without avtiug u|>ou the i-apour 
ofnlcohol. He puts in to a dat VMscl the spirits whii-hlif wishe* 
to rectify, Aitd in snuiher vessel stBtidiiig oti a tripoil over 
the Hpirits, he puts a <]ua]itity of dry chloride of calcium reduced 
to a coiuHO powder, luul covers tlie whole with a large ghus^ 
roc4<ivfr, placiil inverliNl over a flat dUh containing enough of'V 
mercury or melted tjdlow, to oxeludc elTcctually all communi- 
cation betneen tlie external air and the iimide of tlie rtt«civcir< h 
The ApirilA Iteiiig a comjiouiid of alcohol and n'iiler, both ol^ 
which li(|uidK evaporate at the common tempemturc of the 
atmosphere, tltc receiver in mkui filled with tlie vapours of 
eaeli. But the chloride of cnli-ium alMorbing the ra|Mkur of 
water as tint ivt it !>> formed, tbv H(]UPou«> portion of the liquid 
cunliuuMi to evaporate; while the alcohol vapours not bcio^ 
absorbed, continue to fll tlie receivvr, and by their elasticity I 


f>f»r«nt all fftrtlior oiit]>nration of dutt liquid. This pruoess "m-u 

['tk4ng^ commiml for wvera] Klayti, the spirits obrioiuly naat 

fiwcbnic »rr(mg*r. Wlien th<? tflilurWc of ntciuro hegiii* to 

ipp^ar moiM ou lh« MurfiuM', t)i<< proceM miot be Htt>|i(i«(l, 

[■Strppow t)ie sitedfif (fnivity of the 9piritx at first 0-920 by ibis 

tint pracuH, dt« «|H>cific gravity will prubably bo n-<)ucml as 

Imr am 0>80Q. Kcmore the first poTrioii of vhlorido of culciutn, 

'lind fprat the pru^HA with a fresli pottioii. By repeating the 

I 'procMs two or three titn«s t}i« Rpwilio gravity of tlte spirita 

nay beeaallj' reditoed to 0-8I7.* ' ' 

Mr. Ilinmiw <lTiih«fn i>f Olftsffnw hax CTin^Wrnihly inipnivwi 
thi» ]irocrs8, by suMilniing quicklime for dilorido of <-ul(-iumf 
iMd'ti)- 'pottJiig the fikohol mill Hmo uiider the exhaiuted 
KCNM\^r irf »ii nir-ptiinp. 'llii* incvnue* the lapidity of the 
|ir.>c«*««, iind pntiuiblyM-raHiAmagmtUrincMamiii th«Mri-ngtii 
I of Ap alrahol. IikIpM, tie was sbl<> in this wuy to produnt 
rthMlut<> klruhol. This mode of rtctifyiitg spirits ini|rht pro- 
Mr br employed it-ith ad^'atitagc- by the rectiAcr. Tbr lorn 
'of nlitihol wouM not he grcnt, and tlu> lime though slacked 
'irotitd itot he in the lKi-<t Injured in m properties; but might 
rbe applied itgain and n]Epiin to (li« »nme purpose, by simple 
Mpft«ii«* to a ml hral-t 
2. A k-ohol obtAined by these processos is u tnuiRparent liquor, rcvpmm. 
'colaurlpss ai n-ater, of a pleusiit Hmell, and a tinmg penetrat- 
ing agreeable taste. When <<w»lloived il producer iiitoximtiun. 
Its (trop^rties differ (M>meM'liala<'r«jrdiiig to itN !>trengtfa. When •"^■' 
1 ^irociircd by Ijou-itK*]* or Uiditer't> procetK, we maj' dutinguiiih 
■" It Sv ihi" natnc nf /mrr ntmhiJ, or tthmiliitf nhiihiii, iis no inflli<id 
known can di-pTivv it of iiny more water. Whi-n tliL' Kpt^cific 
'jfTtivIty it hlglirr, the iilc«>hol \% cmntumtiifitt'il «itlt water, ai»d 
tthi* propoTtitnt of ihut liquid prrwnt iiicr«wv« with tlies]iedfic 
'gravity, Chrmivtn, in general, huve einplnyt'd tlii* impure 
Jeohol, or ihiH mixture of uk-oliul and water, in their exf>eri- 
'tnenta : and a-t ihey liave too oftun ni'^leetn) to point out tJic 
•ptvjfic gravity of the npirit used, w» ore stiii in Home n»»i»urv 
Ignorant of tin' propertieit of tliis imporliuil liquid.^ 

• Ann. lie Chun, rt dc Pliy*. sxix. 3«S. 

: Edinlmt;:!) PhiL TVant, sL !?& Mr. tjfnhnm round that chloriile of 
(akiim maid nnl Iw immI mllioiit (oniadcialilc Iom of ihc alcohol, becauM 
il abaortM alcrahnUc fapour •* >tll ti* aquoous The loine remark appliec 
[n Hl|ihurk ockl, »hkb ihcrcfoTc wowld not answer for coucuntrating 

I Pahrtnhcll VM oMoflhrAntwhouccnninailMaitaf thercwuritable 
impatioi of aUobol whh cxaclneas. ICi okobol «aa of ibc speclEc gr^ 



Clap. III. 3. Akohol u perfectly limpid and reroarkably fluid, and il 
may be exposed to r lower t«iii)iprattir« iliaii any ulUrt knovm 
mbetaoce witlivut Umag itn fluidity. Mr. Wnlkcr of Oxford 
reduced an alcohol UtrrnioniKt^r to tiiv tvmpcruture of — 91" 
without jiroduciiig' any change in it. But Mr. Hutton of 
Edinburgh announced in 1813, that lie liad been able to frenc 
it by expofling it to a cold of ' — 1 10^. 'i'he alcohol employed 
by him was of llic specific gnivily 0'7flrt at the Irmpernttirc of 
60°. He suys tliiit tJiv alcoliwl divided into tbiec Luyers. The 
uppennoHt vna yellow, the undermost wiw alcohol. What the 
middle one wus he does not Hiiy.* But tti Mr. Hultoti has 
tliougbl proper to conceal the method which he employed, and as 
no one else has been able to produce so great a degree of cold* 
the IVeezing of alcohol mmt slilt he considered us doubtfuL 

It is a very volatile liquid. Fahrenheit found lluit alcohol 
of till- Kpeeific grarit)- of abont 'BiiO, nt tiie teinpentturi! of 00°, 
boiled when heiited to I7&>.f When of tlie i)j>eclfie gravity 
•eOO it boils nt 173"^. 

The following table exhibits tlie boiling point of alcohol of 
TBrious Btrengthi, as determined by tbe eipertments of Yelin.} 

' '<iiit> 



So (n»it) or 















I have inserted tlie«e results of Vetin (tliougti satisfied tliat 
he places the boiling point too low) to draw the attention of 
experimenters to the variations which he olwcrvcd in the bolUng 

»ily SSS ftt the teiiipenitun; of \». See Phil. Tmn*. ITS*, vol. nxifH. 
p. 114. Pourrro}' infarmn Ufltliutthctpecificgnrit^ofthcnioit hiiMync- 
tified »leoh(d in O'M03, oil bout ■pocifyi'i^ the Icmprrntiirc The cxirauity 
of Uauuiv'i hjiltuuiulur (or ii|iirit^ (iKCortlin^ to Nicholion'i tnbic, (Juorl* 
Jour. i. SD), AiiBwera to tlw ii|><:cific grsTtty •»\T, temp. ii'. Thii mar be 
coiuidciviJ II* l>(.70ntl the »lrunglh of the ulcohol uicd. In Oerniony.bcfera 
Lonili'i ctpcrimmu, the Mrongdit nlcohol Kumn seldom to hiive exeMdcd 
O^TS\ tal-ff; nnd iathn country it i«eonimonly i^onnilerubly weaker, TIm 
highot pmnt ot Clnrk') hy Jr«iDeIer cormpondii with iiUohul a( about '634 
U 30*. Dr. Lcwit «l«lci the purett ulcohol of ihc upocific gmfity (^AsOl— 
NcuDiaii'ty Chctn. 

• Annala of Philooophy, i. 881. f Phil. Tram. 1724, vol xxxiiLp. I. 

t Kaitm'i Arch. i. Ma 



at very tnmll dniif^o m the iitreiif|;iJi. Ho found Umt bm. il 
■tcobol of 0-800 luul Uifl lovMt boiliii); point, uul lluit alcohol 
of 0-791 requirml a higher lcro)M.TmlDr« to Iwi] tt. I nm p«r- 
tJOMletl thitt thcnc rr«uUa of Ycltn ore tnae<»tnite, autd that the 
followinf^ table, furnished hy Gruniii};, * comca nearer tlie truth, 
M 1«IM it agrees roucb better with my own tmla. 






























































Boilii^ conrertii alcohol into nn elastic fluid capahle of reaifit- 
ingthepf«asureof th«atniaRpli(yr<> wilnngi» th« heat continues, 
without undergoing any chungi-, hut Again condeniied into 
alooliol when liie lompemture ih n-ducod. Its spedfic gmvity, 
acconlliig to tliv cxperimeots of Gay-Lu^suct it l-6l33.f I I 

bcliorc the tntp qiedlic ^rravity to be 1*6<)00. 

4. Alcohol haa a otroug affinity fof wator, and is miscible Jj^'illn. 
with it in every pmportion. The specific gravity varies accord- 
iti^ to the proportion of the two liquiiii conihined ; bot, as Itap- 
peng ill almost all combinations, the hpccitiL- gravity in aluiiyH 
gnmUr than the mean of Ihv two Itquidx ; oonscquently there 
■ amutual |>cnctnition : and as this penetration or conden«ition 
varies ako with the proportions, tt in cvldt'nt tliat the specific 
grarit)- of dilTetent mixtures of alwhul and water con only be 
BNoertain«d by experimenU As the Hpiriuious Itquon of com- 
merce are merely misturea of alcohol and water in different 
proporUons, and as their xlrrtigth can only be appertained with 
precbion by means of their fl{H-eiAc griivit)', it becomes a |>oint 
of very gnat importance to determine »-itli prvcioEvn the pro- 
portion of alcohol contained in a spirit of a given spceific grarity : 
nod aa the specific gmvity varies with tlie temperature it ia 
necc w ary to make au allowance for tliat likcvue. 

• IlkiL Ana. SI3L 

t Ann. de Chtm. « Pliya. L £18- 



Oip, lit Xhe importance of knowing with precision th^ .pi(q>ortion of 
alcohol contained in spirits of every specific gravity, has indoced 
many different persons to make experimeotfi in order taiscertain 
this point with exactness; but as they set out from^ alcohol <^ 
very differtoit strengths, it h not easy to oompare thdr results 
with each other. We hav* seen that the pore aloohol, by 
Ixtwitz' process, is of the specific gravity -791 at the tempera- 
ture of 68°. That chemist mixed various pribJltortibUs of this 
alcohol with given weights of pure water, and after all<»wing the 
mixtures to remain for 24 hours, took the specific gravity of 
each at the temperature of 68°. The Ebllowiog table ezhibiti 
the result of these experiments. The first t^p columns con- 
tun the proportion of alcohol and water (in wei^} mixed 
together, and the third the specifio gravity (tf the mixture at 
68°. I have added a fourth oolimn], cootuning the 8pe<dfic 
gravity at 60°, the temperature commonly pnferred in thh 

nulurs of 

100 pub. 




AlnboL Wit- 















































































































































































* Crell'i Aniub, 1796, i. 303. 


1- It 

1 •„■!■: 



ICO Pun. 

9p Ornliri 



usr. 1 uaf. 



»1 w. 


1.. i..,|., 









- 1 ! ., - .1 




903 . 














m . 









„\i 111 





















































' '* iji' 























'(■■- ■■' 














































































































-'— ■ 








Mr. Tnlltoi of tlic Dcrlin Academy publigli«(l an elaborate 
•et of cxperimcntM upon lliis subject in th<! year Iftll.* Hie 
following tiiblc which esJiibits the irtiult »f his expcritnrtits, 
I coiMi<ltfr us d«Mn-iiig to br ^^norally known, tliough, as be 
Bted volumes inMoad of weights, lib cxperiiiieiin cannot be 
expected to possess tlie iiecurac)- of those of Mr. Oil])in, which 
I ihall give afWrwards. 

■ dilbcrt'* Anoalea, xuviii. S6A 























































































































































































































0-87 12 





















































UU mruurt* 

4(1 ei"'!! 
















































9nt. II. 

be linpurlance of tliiH olijecl, 1>i>Ui Tor tlie purponco of 
luu uihI ('(iiuaivrcc, li)(1<iim.-(1 tbc BrilUU C>avi>rnincnt to 
mploy Sir Cliwlus niuf^cii to iti^tittitv a wry tniiiuu- and 
an-umtc M-riv* of cxjK-rimenl^ An account of llic«c vnm pub- 
lishfd by Bla^deti in the Piiilosopliicnl Tnmsnctlons for 1790; 
ami a set of tables, cxkibitiiiG; tlic rosult of ihpin, was drawn tip 
by Mr. Gilpin, who had performed the expeTiment*, itnd pub- 
Ii))li«d them in tlie Fhilot«iphica] 'I'rnnsitctionH for 1794. Tlie 
folbw-ing fjiMe, cxtTHctt-d fn>m these, coittnliii tin- specific 
^rity of different mi.\ttn\-» i>f alcohol and water at every 6* 
of t«inpi'riiturc from 30* to 100°, Th<- alcohol employed as a 
ftudard n-u of the !>pccif)c fjnivity 0'H25 at the temperature 
rf6D': and was eomi>o^d, accunliii^ to the oxperimcnts of Mr> 
Gilpin, of lOOparta of alcohol of the specific ^ravit}- 0-814 and 
4*& nf vater. From the preceding table, w« Me tliat alcohol 
af'825 b eompoaed of 


89 pure aJcobol 
11 water 






inn — oito*«oi^ifflso-"QO(e'* 







— — — flowqit-in^o»-«enao<» 



oDinn — oDifjMaDi') — etn>-t^m 













■! - 

oit-inMOQDinn — xcovj-MAU 


BtjmrtW'NMoiws'j — — — --00 






— O«9*»-0!X ■-£;« — — 5S — eg 

m »- .fj « ~ a t- ..1 m — X 1- "-1 Cfl o 

Q101SK3:33iS'. SIS'. CVffiS39SA93 

— — — — Sit-5i«9i «J«'fl»Oi>n 

SM0!«5l9t9J2l9J — — — — — O 


■5» iNC't«W« — — — — cossoc. 
a^ S3 K Ci SI S: O) 3; 9-. 31 7. 01 7> 9: O 30 

mmoiMMw — — — — <_.»_. 

MM tr. 

" 9J o x o *i i* — a: 'o 

— e 31 X f -* 

^ Ss C^ SS O 33 

— . — — — soosoSmc-. ciS.» 



O CD "f^ M 

« go * 

i X 3; « 

8 — <eoe^t*'''*X'"'^««'^ 

OX>!S5i — 51t--TTtO(-'aM — 3) 




CMv. ML 



r 1,— ^*tf >tfB ^^ ■— -- 

> in tr CD Q O 

^ 9) GO m 

O) 0) Oi 03 O) Ok 9 w} 9 


«o lo eo — « I- " " 
>q tn uj m 9 « 
oa 09 o> o o A 

I 2 »? » i? 

^ 9) e OD (O -« 04 
•B « KS * ^ ^ J 

Oi Oi Oi Oi Oi Oi Qi ' 

' 00 «e 4 

I M M A 

' O) O) A 

COOO— " — -■« — — o 



^ ^ ^ a « so n m .. -. -, 


O) ^ 9 

>a -9- ». _ ^ — 

b* 00 9> 93 O) ^ 
CO 3 « 

-: «. 00 c* <e -T 
«o If 9< e ec s> 



SUJ t- -< 03- op « If 
E4 &) N -• 5 O 0> 

S* « Ol — — o 
_ * * <o « « — 



«■*•*« — 00 — ai in--^ oi 
««Mn!-3w« — — = * 

Qi Qi d ^d & C'j a Oi Qi Qi ip 

n ■* ^ -^ t) » -f 'f tr- 

— op)t--*o - - - 


_> 1-^ — ' ■— < 1,^ I..J ijj 

S30 OO X ^jC t- l7- 
A oi 0) 93 03 Q!} 

t- I- I- I- t- i~ I- I-- 

I <s M 

< -« -« •if ei (D oe 

I s -> S o> 

t- « 

— — 55 — cst-ONob^oi 

Oi Si 9-. 7i n 7. 7. Q O » 


BMS-f'N — OOOM ^?t — 
to W «> « "-T O O 115 o « 


I ifl e tn o in o . _ 
' * rt -fl ■* !* I- t- X 

IQ © 



L m, nature of aloaho), Stabl tliought that it was composed of n 
very light oU, unilod by meaits of an acid to n quantity of 
water. According to Junker, it wiuk conipoitcd of phloj^loiit 
combined witli water by means of an acid. Cartbeuiier, on the 
Other liaii<l| alBmiiNl tlmt it contained no acid, ami lliat it wvm 
nothing else tlian pure jihlogitttuii and water. But tliotc hypo- 
diesH were mere assertions supported l>y no proof wlmtcver. 
lAroiner wan llie limt who attempted to analyze it. He borut 
a quantity of alcohol of the Kpecilic jj^ravily O'a'iO.? in a glass 
jar, AlAiiding over mercury hikI filled witli oxygen gns, and lie 
cnlculiitcd (be constituents of t)ic alcohol from tlio quantity of 
oxygen gas cvntiumed, and the quantity of carbonic acid formed 
by ^e combustion of a given weight of idcobol.* But the 
rcsidts which he obtained by this process could not 1>c acctirate, 
because a quantity of the alcohol would evaporate without 
burning, and he had no means of determining the proportion 
which tliis quantity bore to the whole. In the year 1 807, Mr- 
Theodore de Waiiwuro resumed the investigation of the com- 
position of akuliol. lie tried the method of I^ivoUicr. H« 
likewise detonated a mixture of vapour of alcohol and oxygen 
gas by means of electricity. But the metliod upon which be 
put the greatest n-1iiiiice was to discompose alcohol by passing 
It through a reil hot por<.'clain tube and to analyze the corohu»- 
tiblo gas which wait produced.! I'"^ re«ultH which be obtained 
by these different processes differed considerably from cadi 
otlier. They were no doubt nearer the truth than thoM of 
Lavoitiivr; because conddciuhlfl progress huil been made in 
the lut of analysis since t}ie time of that philosopher. Bat 
they could he considered only as ajtproximations. M. De Sau)»- 
Burc turned hi.t attention to llih Hubject again in 1819, and 
published fi new aiuilysis of alcohol, which nuiy be considered 
as approaching us nearly to precision as llie present riatc of the 
science of chemistry will ndmiu He emplvycil for his analysis, 
alcohol of the spccilic gravity 0-830'J at the lempeT&lure of 
OS'S', obtained by reetifjing common spirits. This alcohol 
was a compound of 13-S water and fifi-2 of the absolute alcohol 
of Kicht«-r; ibu water being Mibtraeted from the producU 
obtained, the re«iduc gave tho comjMNulion of the uhsotute 
alcohol of Uichier. His method of analysii vna to pass tba , 
alcohol ihrdiigh a red-hut porcelain tube, and along a glass i 
near six feet in length Bun-uutKkfl with ice. All the product! i 

• Hera. Pw. 1781. t NicholMn'ti JouroaJ. xxt «5. 



mrrr enrvfuUy collcctol and wvi^liod. There wan a little c)iar» '•**• "■ 
rod deposited in (he porcelain tube atti) a rery little oil in tlio 
gkoi tube. The water condenHiNl ainnuntod to {{^ of the 
wvik alcobol employed, and it otntuinf-d j^^.yof il8 wnghtof 
alMolute alcohol. Hie comtittnititdu ^ik wvi^hv^l 912-3 gtaiiis, 
{llw weak alcohol employed wan l'J56-7 gr.) and there wss a 
lOK of 56-82 grtuiu. 'Die gas was burnt in a eudiometer with 
oxygen gaa. The products were carbonic acid and water. For 
«Terj- two volumes of carbonic acid produced, three volumes 
of oxy^n were consumed. Now thin ii the property of olefiant 
gu, Hrncc it followM, that the frat, it pn-c>«ely the same in 
it! compmition, as if it were a mixture of viiponr of water and 
ulefiant gas. The result of the analysts was, that tlie absolute 
■loobul of Ricfater is a compound of 




Or like compodtion may be tlnu otatcd, 
Olcfiuntgus . 





It woiiht apppear then that by vxposiiig the vapour of 
akobol to a firoog red beat, it is converted into olefiaut gaa 
mi vKpoiir of wntrr. If we suppose it a compound of oiia 
volntne of olefiant gwi luid one volume of vapour of water 
redneed into one volume, it« spvcLtic gravity in the state of 
npour would be l-atf72. For 

S|). gT. (tf olefiant gaa is . . 0'9722 
-■ vapour of water . . O-ii'iSO 

1-5972 s »i*. gr. of 
hoi vapour. Now llic ^ocific gravity, as detennined by 
•Loflsac, is 1-C|:J3, which ditfem from ibe Mpecilic gravity 
Jerivrd from that of olefiant gus and vapour of water added 
together by only one per cent. 

'Iliua alcohol (if we ctui confide in the analysis of Saussurc), 
a caiD|K»iod of c(|ual vuliiine*) of ole&uii gas and vapour of 
united together and couitenHcd into a litjuid. Oleliant 
ataiuM two atoms carbon uiul two atom* hydrogen, while 

reuthal compounds. 

Oiaik iir. crater is composed of one atom oxyg«n and one atom liydrog^en. 
Thus the atomic ooiiiititueiita of alcoliol are 

1 atom oxygen . . =1 

*2 »t»mii airboa . . si \'& 

3 ittoiD!) bydrogcn . . = 0-375 


and its atomic weijrht i«t 2*875. 

'Die analysis of S»it«Mur« luis been confirmetl by MM. 

Dumaii and ItouUuy, wbo found tlie con»tituejits of ubsulutc 

alcohol to be 

Carbon , . . . 52-37 

Hydrogen .... 13-31 
Oxygen .... 34-Gl 



ajDahal cm 

How tliis is equintleiit to 

2-017 atoms carbon, 

3-07 aitiias h)'drogen, 

1 atom oxygen 
conatitutiug very near approximations to the trulli. 

6. Ak-uliol mulily di«solv<-n bromine and iodine, and foms 
drep-colourvd solutions, ubioii art witli eonsidcrable energy 
when tukt-n into tbi- stoinacJi. C'blorine gua is absorbed by it 
in cunstdenible quantity, ibe alcobut uc-quiroK a greoninb colour 
and undiTgooii partial di?compo»itiun, Uie iiuturu of which Hi.:einM 
to vary u-itb the stren^jth of the iilcoliol. Tbis nt least is tite 
moi^t prolnililp rciison why the resiilbi of Scbecle, BerlJioltet, 
and 'rbenord, differ ho muck from each other. Schoele obtained 
muriatic ether, Bcrthnllel acetic acid and a sweet matter, while 
'I'lit-nard uhtiiintrd stomc uivbonic ««d, a eliarry nuittvr, &c 
Vqgcl assures us that if a current of chlorine gas be pa&&e<l 
tliruugh alcohol, exposed to the direct niyti of the siiu, combu»- 
tioii lalu-s pbicp. It is said by Berchi that if two [>arl» of 
chlorate of potash, 12 parts of alcohol, and one part af sulphtiiic 
acid be di&lilleil, acetic etiier pa.4ses over into tlie receiver. 

7. I no vulumeti of alcohol, at the tompcniture of 64°, alMorb, 
acconling to Saussure, 16 voluravs of oxygen gas. 

lUU volumes of alcohol at the t«mperalure of 64", acoord- 
ing to the some chemist, absorb live vulumiit of hydrogen gas, 
4-2 volumes of azotic gas, 153 volumrt of protoxide of iuu(«, 

• Ann, de Chim. et do Pity*. »K»ti »7. 




ALCOHOL. ^^^^^^* 283 

14'S rolumos of caibanic oxi<Ie gna, 186 volumes of carlwnic 
acid gas, aod 127 volutnejt of nlctiaiit go*. 

It diH>* tiot (tL«udvi' lioroi), but it dksolvi-? bomdc acid, and 
tlie Kolution bunu witli a griM?»-colourcd flunic, wliich is 
dtancterfatac of Uuit lu-td. 

One part of pboephorus diwiolves \n 320 cold and 240 hot 
alcohol of tlie specUio gravity 0-799. 'Dtv liist soltition Icta 
&1I R pordon of (be pIxFtptiontt wlivii it cools. If (lie alcohol 
duM aalurated witli jibuiipliuriu be Imilcd, the x'apour which 
ettapea k luminoiw in tlie cUrk. When ibe alcobol is dro])t 
into wntrr, n tnmbcnt flame plays an the surface of tjie lt<|ui<l. 

When Htdpbur and alcubol arc brought into contact in iJie 
ftstc of rapour, tliey combine and form a reddish coloured 
Uquid, which exltates ihi' odour uf »iulphurelti'<l hydrogen. ThL* 
eam)K>uiid was lirst fornx-d liy the Count <lt; Lauraguais, who 
employed the following pruccK^i: Some flowers of »ulphur 
were put into n large glast cucurbits, having a glii>B* vessel in 
Ettcentre, conliiining aU-uliol. A lieiul u'lis adjiuied, diecuciir- 
bit placed in a «aml-lKitb, tuid heat applied. Tbo sulphur wus 
ToUtUuwd. and the alcohol converted into vapour ut once. 
These meeting together in the head, imiicd and formed the 
red liquor wanted.* It was «n{>poticdbychenii>sl^ that oulphur 
cannot be dissolved in alcohol, except by a sttnilur proeeat^ 
but from tlie cxpcrimenu of Favre, this does not appear to be 
the ensr.]: He dige«ieil, during 12 hour*, one [lart of flowers 
of sulphur in eight [Nirts of alcohol, oftbe isjnt-itic gmviiy ll-i^)7, 
in a beat not sufficient to produce boiling, llie uU-ohul luwumcd 
B yellow colour, and acquired the smell an<l Ukste of nnlpliur- 
ett«?d hydri^n. AnolJier portion of the same alcohol was 
dige«te<) for a month, cohl, on itiilphur. The effect was the 
M1D«. On trying alcohol of various streiigtli from *817 to 
*d67. he found that the alcobol acted with more energy in pro- 
portion to iu strength. 

The sulphuretted alcohol prepared by I.auTnguaLH' metliod 
codOUM abotit g^lh of sulphur. The sulphur w jireeipitated 
by WBl«r. 

At tJie lempcnlure of 64*, according to Sau*sure, 100 
ralumcs of alcohol ab»orb 1 1 6 voluinen of »ulphun>u8 aci*! gas, 
and 600 volurocA of sulphuretted hy<lr(>gen gas. 

• Men. Par. l7M,p. ft 

t 8m the EtffMnCs de Chjrniie of the Dijon Acailemy, ui. 867. Four- 
avj't ConooiuancM CbjiDiqitci, viii. 
I Uchkn'* Jour. a. 34S. 



onfLtVL The solubility of selcniuia in alcohol in unknown; bat it 
readily <ll««olves selcmou§ acid. 

These arc tiie only simple sutMtnucca upon which alcohol 
lias any notable action. 

8. I shall give an account of the action of the oxj^n adds 
Willi a simple base upon alcohol in the iioxt action. 'ITie fol- 
lowiii|; table exhibits tlie solubility of such of the oxygen aci<li 
Willi compound bases in alcohol as have been dctennined.* 


lb parte oTjilcoboL 





Oxalic acid 





Vinic acid 




Gallic acid 



























In every 



Stearic < 






In every 




Oleic } 








0-792 ■■ 

Itiisaj-, Lccauu, 

























Biimy, LeaniL 


Mellitic acid dtstsolves readily in alcohol, and so docitric and 
tartaric acids, though tliese two are more soluble tn water 
Mucic acid, malic acid, anil Idiiic aeid, are iiiMilubli> in aloohol. 
Formic iieid, niid crystals of acetic aci)!, also readily dissolve. 
Mecoiiic, pyromalic, pyrokinici and pyroturturic are also soluble 
ill it, 

9, Alcohol diMolves pota-ib and soda in great quantity. The ! 
solution is at finttc«Ioitrle^; but it beeomro ^dtudly yellowish 

* Taken from L. OukIju'i HMidbuch da Thcorixlieii Chemie^ ii. 300- 


broim, owing to a jmrtial decomposition of tlie alonliol. l.ilbi« 
it ()iwu>lvcH] Ky it only in Kinall quantity, and prolmUly only 
vben thL> alcohol w woak. 

Alcohol diMolv«-8 very littlo bnrytrs, strontum, or limv, C8(>o 
rially or the ItMt. It dws not render TxirytfJt ornlrunttan wator 
muddy; hut it precipitatea die lime from lime iivater. Yet, 
according to Bonaster, wlicii alcohol ia hnilt-i] upon lim«, it 
lake* up I'uouf^ to reMtore the hluf colour to litmuti [Ki{H-r red- 
dened by rinrpir, anil to Ih' rendered muddy t>y oxalic acid. 
Ma^ncfna u Mill lorn mliiblv in it; yeti according to BonaBt«r, 
if VTL' lioil alcohol on magnesia, it acquires tlie property of 
restoring the blue colour of litmus paper reddened by vinegar. 

None of lite eartlu proper are ooluble in alcohol, nor any of 
the metallic osi<tea except tliooe wliicli have acid properties. 
Thus it <ti«M>lves chromic acid, and imili arwnioiis and arsenic 
tciAi, Many of the metallic chlorides and iodides are soluble 

A great niimb«r of the salts arc soluble in alcohol. Flut I 
■hall point out the nolubility while tre^ttinj; of each salt in a 
tuh«equent part of this volume. 1 shall, however, exhibit the 
tolubility of a few of these bodies in tlic following tnhlcN. 


I. Salutaneu diuolrtd in large quantitiea. 




Pem^hatc of iron 

Nitrate of cobultf 


240 parts 



. 240 



. 240 

_ lime] 

. 300 

H magnesiart- 


. 694 

lHuriate of zinef 


. 240 



, 240 



. 1313 

H iriMif 


. 240 

W coi)perf 


. 240 

Acetate of lend 


. 240 


Nitnt« of sine decomposed^ 

iron decomposedf 

^. bismuth decc 



• VrUherinit, PhU. Truu. txxii. 330. 




VUDOi of Ifae SubtUwH. 

ea in 



mt the boil Iw UBu>a>. 

tun (UiiiflTB~ 

Muriate of limef 

240 parts 

Nitrate of ammoniaf . 


Corrosive sublimate 


Succinic acidf 


Acetate of godaf 


Nitrate of silverf 


Refined sugar^ 


Boracic acidf 


Nitrate of sodaf 


Acetate of coppert 


Muriate of ammonia-f- ■ 


Arseniate of potashf 


Oxalate of potashf 


Nitrate of potashf 


Muriate of potasli+ 


Arseniate of sodaf 


Wliite oxide of arsenief 


Tartrate of potash-j- 


Nitrate of Iead§ 

Carbonate of ammonia j 

3. Substances im 

ioliible in alcoAol. 

Sugar of milk 

Sulpliate of potashf 

Borax ')■ 





Sulphite of Boda 

Sulphate of ammoniaf 

Tartrate of soda and potash 


Nitrate of mercuryf 


Muriate of leadf 




Common saltt 


Carbonate of potash 




Tliese experiments were mad 

c chiefly by Macquer and Wen- 

zel.' The alcohol employed 

by W 


sr was of the specific 

• Verwanducbait, p. 300. The solubility of all the salta marledf wn 
BBceitained by Wenzel ; tboie marked f. by Macquer ; aad those maiked ^, 
by Wtbeing. 


ly O'e40. M'«nxi'l Aavs not give tlie dennity of his alco- 

I; (ml iw liir conip!urǤ it with that of Macquer, we maynup- 

puM- it iK-nrly of the same streof^th. As ilie solubility of ^Is 

, depends upon the strength of tlie alcohol employed, the expc- 

of llie«e chemixts niunt be considered m defeetive, 

! they liavt' confined iheiUBclces to one partictilnr deiLslty. 

This defect is in |mrl supplied by the following very valuable 

tiblo of Mr. Kirwan's, eonstitieted frotn hi* own experiinenta.* 

Solubility ofSatu in 100 parts o/ AlcoM nf different 










Sulphate of goda 






Sulphate of magnesia 






Nitrate of potash 





HitTate of soda 





Muriate of potaah 





Muriate of soda 




Muriate of ammonia 



1 5 

MoriBle of magneda 
dried at XW 





Muriate of barytvs 
Ditto en-stallixed 






jBoetaie of lime 





>\^en alcohol oontaiuing certain saline bodies In solution ia 

on fire, its fbiine itt often tinged of different colours aecord- 

' to the l>ody. ThiL< nitrate of strontiiin and muriate of lime 

it n-d ; lM>nicic sci<l and eupreoun xtdis tinge it ^■en ; 

nmrlatc of baryte« girex it » yellow colour : nitre and corro- 

nw Hublimale a yellow colour. 

• On Mineral Wiitere, p. (7+. 



'^'"^ '"- Mr. Graham has shown that several salts when diMolred in 
alcohol are capable of crystallizing in that liquid, and die cry»- 
tab thus formed cont^n a quantity of alcohol essential to the 
crystalline form of the salt. Such salts he calls akotUea, to dis- 
tinguish them from hydrated salts, the name giren to those 
salts which contain water as essential to tlietr crystalline fimn. 
The alcoates formed by Mr. Graham were all soft ; and tlwugk 
most of them were crystallized, yet the shape of the cryfltals 
could not be made out. Mr. Graham prepared fire alcoates^ 
the composition of which was as follows : 

1. Alcoated chioride of calcium. 
1 atom chloride of calcium . 7 

3| atoms akohol . . . 10-0635 

2. Alcoated nitrate of magnesia, 
1 at«m nitrate of magnesia . . 9*25 

9 atoms alcohol .... 25*875 

36- 135 

3. Alcoated nitrate of lime. 

1 atom nitrate of lime 


2^ atoms alcohol 



4. Alcoated chloride of manganeae. 
1 atom chloride of manganese . 8 

3 atoms alcohol . . 6*625 


5. Alcoated chloride of zinc. 
2 atoms chloride of zinc . . 17*5 
1 atom alcohol .... 2-875 


When the crystalline shape of the alcoates comes to be more 
accurately studied than it has hitherto been, we may expect 
additional information respecting the part which water plays in 
saline combinations — a branch of chemistry hitherto very little 

• Edin. Pha. Timus. xi. 188. 

rvfioACETic spiniT. ^^^^^V 989 


IL Pffro-aatit: Spirit. 

Tftis ti()u]il U1U discovered in 1807 by MM. Der<Mn« hmmt. 
ig (ill.- ilutillation of Terdijpis, ami ilie inmt n-inarkabli- of 
prop«Tti€» dvtermineA* Proust, however, hiwl previyiisty 
lilted it l>y dbitilttrijr ncctatc of leiul nnil acotaU- of lime, and 
pointed oul some uf its ino«t ri-nuirk»ble ptoi>«;rlie».t Anil 
l>e showx tliiit it )iad been kliuun to Becclier, who coii9>i<l<.<red 
it M akvhul, and lliat nauini- and Bcrnanl Pluvinct \\aA not 
♦nlirely orerlooketl it. In 1809 it wna again examined by 
Clieae\'ix, wiio i)eteriniiH-rl the propiiTtion of it yielded by the 
Breui aeetutcw, auil iiii)ijis:tcd it to a more ilelailed examina- 
Dti tlion aity preceding chemist.^ In 18*2:} it wns ii^iiu ex- 
iin«'d liy yi Si. Macaire and Mareet, wlio not only coiittrmed 
Pike results obtained by preceding cxperimenta, but subjected it 
lo analysis and determined its conslitution.$ 

^\'hen tlic acetates are iliHtilled in a retort by means of a vntmv«i^ 
(Cnduate'l heat nlwiiyM kt-]>t as low as possible, there eomes over 
wetie add dilute*) with water, and pt/roacetic xfiiril. The 
■Mlllio huw, mixed uHch duircoiil, remains in tlie retort; and 
ibcK flim olT a mixture of carlMniie acid an<l heavy inflamniable 
gH. The metallic )>ase is u&ually reduced to the metallic sbite, 
tnil tlie more difficult tliis reduction is, the greater is the quan- 
diy of jiyruseelic spirit fonned. The following table exhibits 
ibe re^uIt of the di'^lilLntion of !ieven meCitUtnc ucvlales in a 
Hate of purity, aa obtained by Mr. Cbcnevix: 

* JUn. lit CMmta. 1x81. 9S7. 

t Ocbbn's Joui. IIL 37. Pruust'a pe[>vr ■»■*» publisheJ in llie Jour, de 
IV-hri too. 
I km. cU OAm. \x\x. i. 
t KUlMttequv Unlnratll*, Oct. IMS. AruMi* of Philosopby (<d Nrits), 




Chip. IIL 








Uquut pro- 





in rehwt. 


S tB 




The acetates of potash and of soda give a greater proportioii 
of pyroacetic spirit tian any of the metalline acetates. When 
acetate of hary tes ia distilled, the whole liquid product consigtB 
of this spirit without any mixture of add whatever. 

This pyroacetic spirit is quite the same in its properdea from 
whatever acetate it is procured. No other genus of salts tried, 
as the oxahites, tartrateB, dtrates, yield this spirit. Acetic acid 
ia not converted into it by heat. Mr. Chenevix distilled the 
same proportion of acetic acid five or six times through a red- 
hot porcehiin tube ; part of it was decomposed, the liquor became 


[ browD, and its specific gravity vrm Oiminuhttd, but u coiisider- 
bl« propord<Mi remained unaltered. But if cburcoal be put 
fiiUt the poTcekin tube, tlie ncici is destroyed by one diBtillation. 
notbinf^ obtiuiilid but water, carbonic acid, and Iieavy 
atnftbk air. 
PjrTflocvtic spirit Id a whtte and limpid liquid. [t8 ttetc is 
. ftnt acrid and liut, but it bt>oom«it couliug, and in some »ort 
inous. Its siDcIl a peculiar, lutd is compared by Mr. Che- 
'serix to that of a mixture of oil of peppermint and bitter 
tlmondc Its specific gravit)', when as pure nut possible, is 
07664. It bums M-itli a flame, wbiu- oxlfriorly, but of a fine 
Mm wttltin, and IvaVi'n iiu reiitduc. It boils at tlic temperature 
of 16&*. It mixes with u-atcr, alcohol, and volatile oiis, in any 
iroportioti. With hot olive oil it aUo mixes in any pro|)ortion; 
bat iritli that oil cold it mixes only iit cortain proportions. It 
ifitaulres a little sulphur and plio«]>honts au<( is ua exctllent 
MtrcDt of cnmpliof. Wbeii hot it dissolves wax and tallov. 
A portion of (Iiimc substances precipitates as the solution euolst 
Imt water still occasions a considerable precipitate in it It 
^aaolves potash, and becomes darker coloured ; but it may be 
oblaiii«d by distillation a^in unnllercd. When mLxed with 
ndpliiirlc aciil it blockciH and U decomposed, and much cliar- 
Mil ii fermed. When mixed uith nitric acid it becomes ycl- 
Wt aod its properties an altered. Some oxalio aciil is formed. 
Unsiatie add renders it brown. When rlistille<i with this acid 
I oambtnstion takes place, anil a suUunec U formed, pome8S> 
n^ very diAoretit properties from muriatic ether.* 

When a rurrcnl of chlorine i* ptwsed through tin* spirit a 
lU||litly yellowi"li colour is communicnlod- I'be resulting fluid 
im a iitroog smell, tt speedily «eparutrs into two ^rtinct 
iaUt ; the <me lldck, heavy, oily, and tmn.ii>]ucnt, the other 
l^gfctrr lUidnli^htlyopalescenL Thi!ilaf<ldiN>olves in water, and 
MmBiuiieat«« to it a itweel ta>>le. 

Pyroaeetic spirit being :<ijbjeet«d to analysis by Macaire and 
Ibraet, waa found composed of 

Carlwa . . . 55-3 
Oxygen . . . 86-3 
Hydroj^n . . 6-2 



■ Cttntnh ; Ann. de Chim. Isix. & 



"•^ '"■ These numbera are proportional to 

4 atoms carbon, 
2 atoms oxygen, 
3^ atoms hydri^n. 
Hence v-e may conclude that the conatituenta of pyroaeetic 
* add are 

2 atoms oxygen . . 2 
4 atoms carbon . . 3 

3 atoms hydri^en . 0-375 

or some multiple of these atomic ratios. The atomic weight is 
5-375 or some multiple of that number. Tlie difference 
between alcohol and pyroaeetic spirit, if confidence can be put 
in the above analysis, is that alcohol contains twice as mndt 
hydrogen as pyroaeetic spirit. This is rather an anomaly, 
considering that pyroaeetic spirit is both more volatile and 
lighter than alcohol. It would be desirable on that account to 
repeat the analysis again with every possible care, in order to 
verify the results of MM. Macaire and MarceL 

III. Pyroxylic Spirit 
iBMnr. - I do not know to whom we are indebted for tiie discovery of 
this liquid. In London and Glasgow it has been known for 
these 20 years, and I presume that it must have been disco- 
vered in Paris at least as early, as the manufeetory of wood 
vinegarin that capitalhas existed for more than 20 years. I have 
been in the habit of employing it in lamps instead of alndud 
~ for aboiit 12 years. The first notice of it (so far as I know) 
in print was by M. Colin in the year 1819.' He describM 
some of its most remarkable properties, and states his opinkm 
that it is merely pyroaeetic spirit containing an empyreumatic 
oil in solution. Dobereiner mentioned it in 1821, but mistook 
it for alcohol. MM. Macaire and Marcet made aset of expe- 
riments on it, and subjected it to analysis in I826.f Since 
thai time some of its properties have been investigated by M. 
L, Gmeliii4 

Wlten woo<l is dbtilled, the products are water, acetic acid, 

• Ann. de Chim. et de I'liya. lii. 206. 

t Bibliotheque Universale, xxiv. 126. Annals of riiilosophj'(8dKritt), 
viii. 69. 

{ Handbnch der Theoret. Chimie, ii. 3i-l. 

^B PVBOXVLIC 61'iniT, ^T^'V^P *• 

Vt>)'roxyIic «pirii, erapyifumiiliv oil, und a liluck inatlrr which "^^'i 
it ooDKulcTed us aimlo^us (o pilch ur rntber lar. Wh«n the 
waton- purlion, freed m well as potMiljIe inedianically IVom tlie 
lar, is distilled at a low heal, tliefirst porlioii that comes over 
b the pyroxylic spirit, wliicli may be froed from acotic add 1>y fl 
Igiuiian witli limv or nui^ic^ia, »nd tlu-ii distillfition at a low ■ 

Maiprraturc. But it is still cuntaminuted to a great degreti H 

with einpyreumalic oil, from wliieli it Las been lutherto iiupo$- H 

Hbl« to purify it. It may be freed from a cotislilerable portion H 

of this oil by diluting it with water, whicii «iui!;i-« the gn^ateHt I 
(■tt of tbe oil to si.'{>iir:itt', iti.4t^[i^:iiriiig rlic diliiled spirit by d«* I 

^ttnlaiion, UKinru-ruiiTdK rocliryin); il by tlii-Kiint- provei»e» as fl 
^ftinccvcd^ willi alcohol till it be agiun fm-d from the water ; but fl 
thin process is only partially «iicceHsfuI, a conaldenible portion I 

of uil still obciliiiately remaining. Gineliu say!> il ni:iy be nearly M 

kvtd fruui oil by mixing it willi it.4 own weight of sulphuric 

kHcid and cubjeetinf/ the mixture (<> distillation. 
I'yruxyl'^^* Kpiiii thu»pri-|i»ri-dis» tran»|mreutuii4l colourless piopru^ 
ticpud, having a strong pimgeiit uiid somewhat etiiereal smell, 
vbicli I^Licuire and Marcet compares lo that of ant«, and Gmcliii 
to that of acetic etlier; but the Hmell of the pyroxylic spirit 
muit in Cilivtgow (with which only I am acquainted) does not 
Meublw cith«T of thvHR, but im quite peculiar. It-i taste is 
Mnng, hut, puii)iri*nl, and very <liMigrcMit)li>, derivetl obviously 
in port from tlie empyreumalie utl wliteb it holds in suUition. 

lui ■.jK'cific gravity, in the most concentrated state in which 1 
nwihl procure it, wa» 0*8121. Macaire and Mun-et found it to 
Uiilai 150% iuid with this delenniiuiliun my experiments »};rt-e. 
Qaclin "UiU*t ilw IniiUng point to be 137% yet llie specific 
^vily of the spirit which he examined wjik only U-y3(), SVhcil 
RMupletely freed from acvlic acid it d<K-s not redden vegetable 

K It bums witli a very pale yellow flame inclining to blue, but 
^ the light is ciuisitierably greater tliaii that given out by alcu- 
luil. It burns all away without leaving any rt-Mdue, and the 
only ]iro<liicts arc rarbonic iu:id and water. 

It iliasolves in alcohol in any proportion. Witli water it 
Iwvotni^ opaque, otivtousty in consequence of the empyrcumntic 
oil which it contains. It di.violve« readily in oil of turpentine 
and ill liipiid poUsli, acqiiiriii|f at (lie same time a yellowish 
vtdour. Camphor dissolves lit it readily, but it dors not di.'«- 
•olve olive oil. With sulphuric ctlier !( unites likewise in all 
It diMolvesaliule sulphur and phosphorus, niid is 


rids [>r«*ite. 

H good solvent of common rosin and of iibfll lac. Iodine it 
dis8olred by it abundautly, and tbe solution ban tlie same darit 
kruirn colour as the solution of iodine in atcolioL 

Wlivii thu wlutioii of this itpiril in bydtaled potji»b is db* 
tilled iifutr lui iiitcrvnl of u fvw duys tho {>yrflxylio «pirit wLk-h 
(romK over is quite free from empyreumatic oiL Here then is 
a method by wbich chemiata may have it io their power Ut 
obtain tliia fp'mi in h state of purity. 

When mix«dwith nitric ucid and diMiiiod an olliereal liquid 
eMiie« over, wludi, however, is quite different from nttrie 

When ^ ounce mensure of tliia spirit h mixed with I ounce 
tnecuure of nitric adil aiui '2 ouncv invtuun>» of muriatic tidd io 
a flask, and u mwlcnttc lieiil applied, it soon bejEpns to etfrrvesoe, 
an<i a gas comcD over buviii); an exceedingly pungent smell, 
and acting strongly on the nose and eyes. This gas burns 
with a bluish white flame. Its specific gravity I foun<l 1-MA, 
Odd on analyzing it was a mixture of three gaseoiu bodies la 
the following proportions in volnm* : 

Dcuto.'cidc of azote . . 64-37 
Asotic gns . , 7'48 

A new gas . . . 27*95 

Water absorbs 5 limes its volume of Xitia gas, nnd oil of tur- 
pentine i)4 times its volume. 

The specific gravity of the new gas is 4-*236l. It requires 
1 ) dmea its volume of oxygen to bum it, and it forma its own 
volume of ciirbonic aci<l. \\'hon tha combustion » miule over 
mercury a quantity of eulomel is formed at the tsume timtw 
Hence it is u compound of 

1 volume carbon vapour, 
I volume hydrogen gas, 
1} volume chloriiu> gns, 
fMKuJcBMd into one volume. It is u oompoimd of 
1 atom carbon . . 0*75 
1 atom hydrogen , , U*l'i5 
1^ atom chlorine . . 6*76 

an<t its atomic weight is 7-626. To thin gus the niiiMn 
letquiclihriile qf carl>oJi^r»f/fM may be given. 

According to Macuirc uud Murcct, when pyroxylic Gpirlt ia . 


Uixml witli thrioe its weight of sulphuric acid and heated, a ^» *^ ■■'• 
1 fa obtained wbick hurus witli i> hluo ftiune. 

'fUa •pirit was Mibjectod to utialy»U liy Messrs. Macaire aiid 
'Mamt, by volatiluitig a fprcu wi'i^til of it Ilimiij^h red-lu>t 
I hkck oxido of copper. The constituetita deduced from thia 

B Malyau were, 

■ Cwhoa 


H Hy<lro^'n 


" Oxyi^eri 


Tba u equirul«ut to 

^L A atoms oxygen 


B S atonia nrbon 

a- 76 

H 6 atoou bydrogrn 




But no conclusion can be diswn from tliis aiialyiiis because tbe 
■pint wliicb they subjected to analyuit was obviously contami- 
nated with empyreumatic oil. I ani very much iucluied to sus- 
pect that it will Iw found to contain huih less caiboii ai>d 
hydrogen oomparod with the oxygen tluin alcohol does. 


The t«!nn ether is applied by British aiid I'rench writers niN»,»ii«. 
iiuUitcrimitiately to all tlie volatile liquids made by tjic action 
rf acida on alcohol. Hui these liquids are divisible into two 
Wit, txoccdiogly ditferent from each other in their chanictcrn. 
One Ml is quite free from any portion of llie acid employed in 
lis preparation, and coii»i»b( of Ihc very same constituents at 
exist in alcohol, tboti)r|i the proportions arc dilTcrenl ; the otitcr 
■et coniuftts of the acid employed in tlie formadon of tlie cther^ 
ialurat«d with a peculiar volatile and combustible subttuiice, 
which nppttars to be the same in all. Some of the latest dicmteal 
writen iu Gcimany have conliiicd the term el/ter to the fimt of 
th^r sets, and have dislJii^L^lu'sl tlie second set by the t«'rm 
napAthfi. We luivc It not in our power to follow ihis example, 
m till- word luiphth.-!, in tiic English Inngtlfg") luis been utrcutly 
approprint4il to ii very diAerciit !tubstanc«. I ahull sutivfy luy- 
•vLT, tltcrufore, with separating llie two kinds of ether from each 
otlier. I shall describe the fir>l kind in this section, under tbe 
nunc o( tut/ihurir tlher, \>y wliich, or »implyby llic term fllirr^ 
it u usually disUnguislied in this country ; while in ihc next 
•ectiun 1 shall treat of the second kind of etliers under the 
name uf acitt etAert, thuti^li I must acknowledge that the name 



cftip. III. 18 not ver)- appropriate. For these etbeni when first formed 
Iia(fc no acid qualities. Tbey contain an aci<! iiifleed, but il is 
saturated witli nnotLer »ulNtaiice wliidi quite conceals iik pn>- 
perticM. Hut when tlic>e etiiers ore ke|il lliey gradually acquire 
acid qualities, wlicreas Bulpliuric oilier may Ite kept K«r uiy 
leugtlj of time without uD<lergoiii(r uiucli alti^ration in its. 
HMHir. The method of making snlphiiric clhor \x deiicrihed iu Uhj 

dispetiHalory of Valerius Cordus, published ut Niirr-nibiTg ul>out 
the year 1340 : from which Coorad GesDcr traiisciitH-d it into 
bis Thfmvms JCuonj/mide Kttmediu Se^rHi*, published in 1552, 
where it is adled 0/fum I'Hrioli Mce,\ It apjiears to have 
been knowD, though not iii ii »Ui(c of purity, both to I)a:ul 
Vah-iitiiie and Paracelsus, Hut in the writing)) of ehemtsts 
published about the end of the 17th century, I buvc not bcvH 


' 'It^>pcani frum ilic obwrvntion* orPtiinch<;arii)<iDy<Lu«iic,thati 
when k^t for icvcml ycat* in a vcmcI nol quitu Tiill, and ol\cn f^pcned,' 
gWicnitG* ionic ncclic acid. See Ann. dc Chiin. cldc I'h;*. ii. UttanililS. 
M> Henry hu rendered it [imboblc ihnt tliit i* owing to a howII qiHalil]r of 
acetic clli«r whirh i* uRually mixed vriih siilphuriu ciher. Jour, de Ftiw^ 
mRcie. xiii. 1 1!). 

-j- V^'llo«vttr will cuhmiIct the fomiula pvvn lor prK|>anng ihi* OUnm Pi- 
Irivli ditlce hy Uesiier, will be MtisRad [hat it whs very <liffi!ren( (Von tlw 
itulctfytl acidt o( the iiiodiTii«, si'd that it iiiukt linve been ■ uiixlore of aim- 
Avl, fllirr, iinil iwfrl ail 'J' innr. Th« rolluwing h ilic pasiage of OeaKTi 
M qiiotud by lli>ffinnn, from whom lius bcc-'ii inkcn tbc hiitaricol &ct« 
reiqicciinif ilic knowlrdife of ether poiseuieiJ by the atchyniistic«l writera^— 
^ Itccipc villi ardcntia uccrrinii et Icr aubliiimti uucioi qutnque, olei ritrioli 
BU*tcti tniiliindcm, mince in venetinno vilro. et pone in cucurbitan) pnrmB 
nngiial» orilicio, cl Into ojititno urificium cluudc, dimittc itn |i«i' intqcnun 
mcnncni nnt dno*. Dcinitc cfliiodr in I'ucurbitnin, cui rit immedifttc Hnnciuin 
itlcniblonin, ciijuK li)j;iiruin «nbJK-icniU9, jiuiic di-inde in pamun fomnctmi, ac 
diiniiliniii ejim purluni cinoro obrue. poHle« npplicn rceipientcni cl Inio June- 
turuncluuiledili|;enliT,etcKtnilii;uii<insacx villi nrdciitis(|iiasiDlii<liiiti. Vt 
vcro liitiua hoc fiuC, puni- in bHliii'uiii Muriu; ; tic solum tinuin abwiue olco 
nicendc:. ('uin cxtnixtris uuleiii per l>ali;«uui inl'iisns nncios »cx vim uMi, 
pone id, (jiiod n-iiduuni nl. in ruriiuceni. u( urrmiiiicJiaincucurbiticparlaaj 
nttingat, nc novo ct mcuo rrcitii(.-nte uoque nun mo^no Bp[)licalo, lulo jud 
tunun dilifionlrr cinudc Acctnidi? ddndc inudcituin igiicm, rt scnnm cutnlit] 
omnem hnmidituirnt t\mr rclicin tut in cui-iirbiiii, dunce nihil humiili nnpliua '. 
in fiinilo nppnrcat: odbibiia Bi'iiiprr maxinm curu ct dilipentin, ut ipiem it* 
modcrcriii, nc cbiilliai uujuc lul alembici cunalcm. Nam «i bunc cbullitia^ 
Btti|[crit, tcilure non polo, nccjuc jirohilierr, qiiin in trccplRCulun) *glvdli^^| 
Inr, nc totain olenm perdal : lolct enim Tacilimc ebiillirc. 7\tm vldcbis diio^ 
I oiitineri in ii>, oquvum videlicet huinarcm oc |iin)ci>cm ; »ff;Tr|;abi8 rtra 
nnum Rb ultero sintim, im ui ntbil ni]u<uni in oloii roliiii|iialur, oam aqOR 
ilia okuni corrampit ; 6cgTrgaiiiiii ulcuiii mui rc^crva.'* 








able to find any trace* of it,* except in tJiose of Mr. Doyle. 
He was evidently acijuaiiited with it, an appears from different 
paan^s of his writii^p^t lliouj/h he no where describes it )Mir- 
ticuJarly. Hut it wu « p»p<T in lUv ['liil«H(if)hiciil Tnuuactiom 
for 1730, hy a Oenn<in who «dk-d bintM-lf Or. t-'robi-itiiLt, 
tlotcribing; several of its mosl siiigiilar properties, that firiit 
dnw the attention of vh«nii»t!t to tlii& curious li<)uor.} In thin 
pi|ter it Rrnt reet-ired tlie iiami- of ttAtr. 'Ilie (lennaii i-heniists 
loof; diMtiiigutxlicH) it hy the name of mifthiJui. 

1. Sul|)fauric rther in UHUully ])repared hy the fuUavin^ pro- rni«><ii«. 
km:} a mixture of e<)ual parts of alcohol and sulphuric acid 
ii put into the retort, to which a lai^e receiver b then hitvd. 
It M proper to surrouiid liiv receiver nith ice, or at least with 
nhl ttiiter. U«U U applied ; and iW *ixtn as the mtxtuni boils, 
ibe etiter comes ov«r and in condeniM-d, und runs in large strin 
itiwit the *ii<lcs of the receiver. As itoon as it amounts to one 
latf of the alcohol ein])lnyed, the process must he slopped. 
He ether, thus ohiaiiied, is not 4)uile ]uire. It ulwayn contain* 
■Imliul, and i» never fn-e from nii]phurou» acid. 

Iliu iH*|>amtioii of the Itipiid from tlie nulphurou^ and, with 
wllkfa it vt niix<'<l, U called tlic rtcti^mtion of the elhxr. lliv 
mal method, nnd 1 amy udd, the bi?st, is the following, first 
•njdoyed hy Mr. \\'ulfe : Kit! tlirce-fourths of a bottle with 
the Impure eiJier, add a little water luid a [wrtion of alacked 
JblM. A^pUite the buttle with violence, nnd keep it for «omc 
tine in water Ivefore taking out the cork. If the smell of the 
idd be not Tcinovcil, iuld a little more lime, aiut agitate a second 
time. Decunt olfthe eihcr into n retort, tnid distil it ovcr.jl 

The first portion of Hijiiid iluil eoines over daring the di»lil- 
btjoti U merely alcohol iupregimled with a little otjier. Com- 
iBKtn ether is in reality a mixture of ether and alcohol. The 
inetliod of separating tliis liquid is hy mixing the ether 
water, and then proceeding to distillation with a very 

Hi* Olfvm Vilriali JuUr of Lcmcrj-, for inttlancc, in Tcry tlifli:tcnt from 
doacriM bj GMncr. (Sec hi* Cours ilc thymic, |>. iO-i.) 
t Set Shaw*! Bojie, i. KKI ; and i. mO ; wlicrc the pn>c«H for making 
iHhff, and MMHi ofilt moRl rcinnrkiiblc |iri)pcrticiinirc dclailcil at length. 

t Ifd. Tnttt. nxvii. 1CH3. Thin |iHF>or i* Utile cUc thiia a rhnpodj iu 
riha •Ich^iutlkal itljrie' At lh« cn>l o( It there It A nWc b>- Mr. Oodrrvy, 
(lUnkwiii,) Mr. Dojle'i openitor, niciiliuiiing llie uijwiiiivota formerly 
aiaJa ujion It by Mr. Boyle miJ Sir linac Ncwiun. 

{ Frobcniua' procoM wm (irxl published iu ihu fliiluwplilcal Trwwoc- 
;<tfea«, vol, xh. 

B I'niuat, Aaii. de Cbiia. xliL 806. 



II- nuxleratc heat Rut Mr. I^wkz hax oliowii that ibU ni' 
dow not succ««d. The follt>wififr [>r«cwM yieWoH liini aii 
much purvr thun uny that hud Imh-d prrvitiasly ohtnuied : Into 
16 parts of ether, of the spenfic gfravity 0*775 in thv t«^nip<>Tft- 
tiir« of 60°, lie threw dry powdered luilt of tartar, till the last 
poTtiontt were no longer wetlcii hy ihc liquor. The mixture 
being allowed to digmt, the ether wiu tlicn dnvn off. Its 
q)tHHlic gravity wa* now only -746. By thi« means it WM 
deprived of tlit- wiitor which it containod. To romove the 
fdcohol, dry powdered chloride of calcium was thrown into the 
liqutd in the same manner, as long as il would dissolve. On 
Mnnding, the mixture M>pimite(l into two portions ; the alcohol 
hokUag tlie salt in the xolntion siink to the bottom ; the ether 
swam on tlie iturfuce. When Mcparntod fnnn tlie inferior liquor, 
it)i »j)mfic gravity wiM now only -fili'i in the temperature of 60», 
It wnK, thcrcforo much purer than uny former ether deHcribed 
by eheinistis since it never before had been procureil lighter 
than 0-7'25.* 'Ilie otlter tliiis prepared contuius a little of the 
Btlt, frum which it may be freed by distilluttoii. Hut in tliat 
case its spcciiic )^vity increases. Ilie reason seems to be, 
tluil the purest portion of iJie ether assumen U»e form of efautie 
fluid. M. Theodore de Saiissure piiriiied other by nearly the 
•ame process, exvepting that he distilled il off the muriute of 
lime. Ue obtained it of the specdfic i^vit}' 0-7155 at the 
temperature of «8't. By Uie wune process LowiU could not 
oblutn ether of a lower specific gravity than tc? 16. G«y- 
Liisotc removed the alcohol by agitatinj^ the ether with twice 
its weight of water, 'llie wajslied etlier was left in contact 
witi) quicklime for 12 d;iys and tln-n diiililled grudutiin. It« 
tipecific gravity was 0*7 1 ] 9, at the temperature of 77°. iUchter 
obtained it of a K])cei(ic gravity as low as U'706 at GO', I'he 
specific gravity of the purest ether, which Boulluy was able to 
make, was 0-090. 

Uoullay Itas itbawn that we may form this ether, though we 
substitute pho«phoric acid{ or ar«enicj acid for the sulphuric 
And Desfofses has found that tlie same procoM succ4^mls when 
we employ fluoboric acid.|J 
pt*iv<i". Ether, thus obtained, Ls a limpid and colourless liquor, of m 
very fragrant smell, and a hot puugent taste. 

It is so vubtile tliat it can scarcely be poured from one vetsel' 



• Loviit, Crell'n AnnnU, 1700, i. 4m 

I Ann- lie Ctiim. Ixu. 192. 

I Ann. (le Cliim- et ile Fliy*> xvL 79, 

t AnasU of Philoaqihj, iv. -! 
i lliUt. Iixviii. 8M, 


^^^F 8t>l.PRi;KIC ETHER. 

Wwdwr without looinf; a oonniilemble portion of it by evapo- 
ntton. When pourrd out In ihc open uir, it (1tjai[>p«an in an 
kMuit ; an<I, during; its evaporation, produops a very coiHidvr- 
WUt decree of cold. If a ^iaan vessel containing wat«.T, and 
•arroiuided with a cloth, b« dipped into etlier, two or three 
times, and the ether each time be allowed to evapomte from 
4edeAr tbewatvrin llit: |/Iumn fnHMcH, In the open air ether 
}niSla at 96°, and in a vacuum at — 2(^. Were it not, UKTcforf, 
fin- the pressure of the atmoephere, it would always exist In the 
gaseous state. But Dr. Bostock has noticed that it may be 
heated iu a clean ^laHs tube as high as 150° or even higher 
before it emits bubbles. If when It is at that temperatun^ w« 
throw into it any solid body, ns metal filinf^ or chips of wood, 
or IraginrntJt of f^lass, it immediately boils with great violunce, 
and the bubbles of vapour all issue Irom the surliice of the body 
introduced. I'hough tlie temperature of the ether was lowered 
dw boiling {Mill eoniinucd till tlu- hi-nt Mtnic to 102«, and m 
mt «WC to t)6°, whicli 14 the true boiling point of ether.* 

When exposed to the open air it speedily UMumes the 
gf oi» form, 'riiis Ii»p{ien.s, for instance, if a little of it be 
poBred into a glass phial. The vapour of ether (liftplaces a 
con^detvble portion of the aii of the phial, and is not soon 
tfwlpkted. Ingenhousz \vii> shown tliat the specific gravity of 
Ab va)H)ur is very vonsiderablc.t 

Mr. llidton found it 0-V23, the specific gravity of common 
■tr being I.} Gay-Lussac has determined tliv npecifie gravity 
rf thh vapour with much care, .\ccordiug to his ex|>eriinent9, 
it in '2-5MG0. that of air being I .§ The determination of Gay- 
Luwac luf* been confirmed by M. Despretz, «'lio found tbc 
$ftaAc gravity of ether vapour 3-$806.|| 

According to Foureroy and Vauqueliu, it freezes or cryfc- 
taUisea when coole^l Aown to ~- 46".^ But Tlienard assures 

*us tlmt it renuiins liquid ihougli exposed to a cold of — 58'. 
Ileuee the remarks of Foureroy and Vauqueliu can apply only 
I to the common etlier of tlie ahope. 

■ Aonab of FtiiloMfihy (i<i tenet), viii. 196. The tame phenomenon 
wpftan wken ■Icohol, or even wntcr, ia hwited in g1m« lubw, tm liw been 
elMOVcd by Dr. BoMock. Tlii« curioui lubjccl lian btxii inmligAcd bg 
IL flij Iiiinir i but ao MtitfiicCoiy npluacuin of it liu bnu liiiJieito given. 

f tiee bfa Rouvdia fixptrionecs, p. tMk 

I tbuAaut HeoiaJre. iii. 960. Second Seric*. 

Lf Ana. (fe Oihn. el Ph)'*. 1. 816. | Ana. dc Chim.ct<Ierh<r«.xi(i. 143. 
1 Ami. de Chiin. uix. Saih 






Neitlicr oxy)i;cti fpis norcoiniiuHi air produce auy effect upon 
etWr in inodontte tciupeniiureii ; biic in lilj^i li-m}M'ni(urvs tlic 
case U wry <lifrcrt;nt. Ktlicr is rxceoiliii^ly iiidaminatik-, Htid 
wUeu kiridlwt in tUo state of vapour burns with rapidity, with 
a 6iie white Aanif, and leaves behind it a trace of cluircua). 
I>uriiig it^ coinbu^tioii cttrbunic avid k gencnitv<l. How well 
soever it lias been recti fii-d, it alu'ays esliibitii traces of sulphtiric 

Wbcti ethor is admitted to any gaseous body standbg over 
mercury, it doubles the bulk of the gas, as Dr. i^riestley first 
observed. If oxygen gas, tlius expiuided by ether, tte pre- 
sented to M li^litcd cHiitlle, the ethor buni.« with great raptdily, 
but produces uo explosion. But if one part in bulk of lUs 
expanded oxygen be mixed willi three parts of pure oxygon 
gtw, iind kinillod, a very loud exj>lii>ion takes place : the pn>- 
ductif are water and 2, jiartA of carbonic acid.f Mr. Cniick* 
lihaidu, to whom we are indebted fur this inMructivc t^xperi- 
ment, found, that one part iif the rupoiir of etlier lukes 6'6 
purts o( «xy4;('n gu» to consume it rumplcudy ; iind ftuui 
tlie relative proportions of the two products, lie concluded tluit 
tlie carbon wbidi ether contains is to its hydrogen us five 
to one. 

Acconling to Didton, one volume of ether requires for its 
combustion nix voliimcM of oxygen ; tlie renidue consisU of four ' 
volumes of carbonic acid.J 

Now it is obvious that four volumes of tho oxygen gnsmust 

have gone to the formation of csrbonic ucid gas ; the remaining 

two volumes of oxygen mutit liave gone to the formation of 

water, and they must have united with a quantity of hydru^eiit 

wliidi, luul it been in the gaseous state^ would have junotinlc-d 

to 4 volumc». Carbonic acid gas contains it^ own volume of 

carbon ui the giu««ous state. It follows, therefore, from tlio 

preceding &cts that I volume of va|>our of ctlier contains 

4 volumes carbon, 7 i i ■ . . i 

, , , t t^onttensed into 1 volume. 

4 volume!* hjdrogen, j 

I have shown in a preceding partof this work, that a volume 
of carbon vapour and U volume of hydrogen gusarc prt^oitioual 
to an abun of each. Hcnee that ]>ortioii of ctiicr which is com- 
bustible, it a compound of 

4 atoms carbon, 

4 atoms hydrogen. 

* Scbeelei !■ 108. f Cniickthanks, Nii'liolaon't Journal, t. 

t MmifhwlM Mauoirs, iii. 179. Sccoud Scrica. 



SUtPUURIC ETHEn. ^^^^* 801 

The vnpoar in its gaseous state is tli«n a compound of 4 volumes ** ""• 
(or atoms) of carbon vnpmir, iinil 4 volumes (or atoms) of 
' lijrdro^n ga« coiKlviiM'rl into oik: volume. We obtain tlio 
•pfdfic f^vity, tlierororp, by adding togelber 4 tinu>8 the spe- 
cific ^invit)' of those two bodies. 

Carbon = 0-4 1 (!6 X 4 = 1 '66(>6 

Hydrogen = 0-0694 X 4 = 0-277^ 


Hot the spedtic grarit)- of «lh<^r rupour was found to be 2- 5806. 
If from lliiK wc Ktibtract 1-4444, there will be a remainder of 
D'*864, which comeH very neiir (1-B23, = spHcilic gravity of 
v^ur of water. It ts evident from t)ii.« tlint a volume of etlier 
T^Kiur, Itesifte the gwrou« compuuiKl of 4 vohiiiii'ii ciirbon 
nqmur, aiid 4 volumes hydrogen gas, contains also a volume of 
dir vapour of water. 

Tluiiigh tJie comhuMiblo portion of ether beunidoKouK in itsJiUS^T' 
Core)Kmliun to olt'ftiuit pH. iind ibou^h if two volumes of olcfiant n^Snvn' 
p» were ci>nilenMed into one, llioy would constitute a volume 
of the combuHtihle portion of ether, yet it is obvious that it 
eonclitute« a (jiitte different compound from olelinnt gus> and 
eoMtlutes one of the luimerouH tribe of subritanceii, composed 
of in equal number of iitom* of carbon and hydrogen, aiiddi^- 
liflgutithcd from each other by the number of ittoDt!> of isieh in 
an bu^mit imrtiele or volume of the rcHpcelive body. Four 
•f tline bodies luivo been already described iii this work, 

1. Carhtt-hydrogett, obtained when pyroxylic spirit i» treated 
with atjua regta. It U a giiK, a volume of which coritAiiin ) 
rojnmc (or atom) of cnrtxm vupour and I volame (or atom) of 
liydruf^en condensed into 1 volume, lleoce itn Epecilic gravity 
'fa0-48((i, and for eomjilete combustion it requires \^ times 
it* volume of oxygen gus and forms it« own volume of carbonic 
Bcid ^Wi. 

2. blefiant ga» obtained liy heating a mixture of four parts 
iWetght of sul|diuric aci<! witli I jHirl of alcohol. It consists 
S volumes (or aUims) of carbon vapour uud 2 volumes (or 

atoms) of liydrogen gn», united together and eondenned into * • 
one volume. Henee it» n[wcifiv utavity it 0'97'22. It requires 
thrice its volume of oxygen to burn it} and it leave* twice its 
Tolome of carbonic add behind. 

3. Tlie vapour of oil gas which may be called triff-carbo- 
hydrtM/fM, as it coiisinLt of three volumes (or atoms) of carbon 


■™- i ^ i M aad tkiee TBlrnnw (or atoms) of h y i lr ngMi gm MU 

to^e^er, and nmiliiiiiil into one Ti^nme. Heoee ila ife> 
gnvity » l-458c&. It requim 4-3 timea its Ttdnrae of flsy; 
gm to bvm it. aad it kares behind three times its volam 
caifmiic acid eas. 

4^ The combiistiUe pan of ether rapoor which may 
called Martb-caibo-hydro^n, as it is a eompoond of 4 volni 
(<walaii»)of carboQ Tapourandirolomes (oratoms) of hjn 
gea gas coodoHed into one rolume. Hence its tpea&e giw 
is 1*9444. Itrcqures6time*inTolnmeofox^aipBtoli 
h, aad it leaves behind it 4 times its Tolmne of c«rboaieadd| 
Theodore de Saasrare analned ether abo bj bammg it f 
mtlt e u gia. He detennined the qaanttty of ^oboiue i 
fbrmed, and of oxTf^eo gas eonsomed. This gare luB 
carboa aad hytbogen in the combostible portion of the y^ 
what was wanting to complete the wei^t q£ the nqrasr t 
fwaed be eoasidered as water. The eoostitacnti fband ia 
way wvra 

Hvdnigea . 14-40 

Carbon . . 67-96 

Oxygen . 17-63 

Now tbeoe nnmbeis ue nearly eqniraleDt to 
5 aunns hydrageo, 
3-93 atoms carbon, 
0-8 attHD oxTgen. 
This ooows as nearly as can be expected to 
5 atoms hydrogeoi 
4 atoms carbtm, 
1 atom oxygen, 
which are the atomic proportions resulting from Mr. Dalti 
analj'us. The experimeots of Sanssure, therefore, save ■ 
additi<Hial confirmation of the constitution of ether ai ab 
deduced. It is therefore a compound <tf 

1 Tolume tetarto-carbo-hydrogra 1-9444 

1 volume nfMHir of water 0-62fi0 

Benee die true specific gravity of ether vapour must be S*M 
md tt» atomic wei^t is evidently 4-62S. 

i., •ABMbofPUoMptij.iT. 4a 


HMtOiiyiu of DaJtuii and SaiiMure liavc bfii'ii confirmed bki.iil 
by Domu unci Iloiilliiy, who obtainisl 

Uirlwn . . . 66'05 
Hydrugtii . . 13-85 
Oxygen . . , -il-iM 


f^umdent to 

4-08 atoraH carbon, 
6'2 utonw hydrogen, 
1 atom oxy^n, 
tutm iip)>ro(u:liin|; theory still ncnrvr than Snumurc's. 

It rrwmblcit alcohol in betog a compouiul of 1 roluine of • 
tnbwtible caibo-hydrogen and I volume of vapour of water 
taoigated into 1 volume, llitt the cat[u>-\iydtt>gca U dilTieretit 
a null 1 in aln>hoi it » olr fiaiil ^as, in ctiii-rit isU>lATto-«iirbo- 
^JrOg H i. Hence tlic reason of llii- greater ^rdlic ^tvity of 
tAtr vaponr anil of its superior combustibility. Doubtlew it 
il Ike aqueous vapour in both that pr«v«nts the combustibility 
km being so great and llic light emitted ho KpIendentM whea 
oMant gM ibtelf It biimL 

Itignhousi WiM tho Srst who asc^Hained that tlie vapom of 
nW detonate* witli common air aiid oxygon gas. Ills account 
•f iW experiment vnu firet publisher] in a IcClor to Dr. l*ric«tley, 
10 one of the original roltunes of that phituMiphcr on utr, and 
Uktwiof in the G9tli volume of tlK> Philosophical TranKictioiHt. 
Kit inetboal wn» exceedingly Himp]«. A single drop of ctlicr 
liliiUI into a bottle holding about 10 cubic inches of air, gives 
k de property of dcttitialiiig. Too much etluT destroys the 
(Utaatioin. With oxygen gas the same method succevds.f 

When etlicr, in the state of vapour, b made to pass tliroogh 
trid-bot porM'Iuin tube, it in decomposed completely, and a 
gnu qoantily of carbutettod hydrogen gai in obtat»eil.| Unun' 
nn^ junior, repeated the experiment with precision. He pumed 
l>09 partH of the ether through a rvd-hot porcelain tube; tlie 
pndacts vere pa followa: fij jmrtA of churcoul in the iuIk', 3 
I of volstila oil crystolli/ed in thin scutes and smelling of 
I ; 43 parts of a volatile oil nearly black, partly fluid and 
■ the consistence of honey ; .1 jiiirlJt of water, uixl 948 
of heavy inflammable air. The loss, amounting to 

• Ann. dc dum. ct dc I'h;*. x»ri. 909. 
f S«e IncRnhoutl' Rx|trricD(Tii, p. 171. 
j Dutch ClKwiMa, Joor. <k Phji. sIt. IM. 



ciHi- III. 100-75 pam, «■** chiefly owing to iJie «8capeof oil in the 
of vapour." 

If we fill u bottip capable of holding ihrt'c or four Rngltsh 
piiib witli clilorinc gns, fonncd by tlic itc-tivti of mumtic acM) 
oil clilorulc of polasli, taking care to expel the watrr us com- 
plctoly iLs pixwible, iiiiti thon throw into it about a dnu:fam, oi 
half a drachm, of good I'thcr, covering ibs mouth immediatet] 
witli a piece of light wood or papiM-, iii a few »ccon<ls whit'- v; 
pour will he perceived moving circular iii the bottle; this will b< 
fioon followed by mi expWion accompanied with flame ; at tin 
same time a very cwnsidenible quanliiy of charcoal will l>e de. 
posited, and the bottle will hn found to contain carbonic avb 

T uluill now Htate tli« action of ether on tlie ])rincipal ehemicj 
Bobfelunccs with which it U likely to be brought in eontiict. 

If we mix together equal volumes of ether and water in 
stoppered phiul, imd uft4T ngitation set down the phial, tin 
li([u!d speedily separates into two layers, Tlie up]iennoAt 
the efher, not cjiiite free from water, iind tlie undermo*! tb 
water holding tn solution about -^lU of iu weight of ether, 
was first ascertained by Count Lauraguais.^ The specific gr« 
vity of the warer so impregnated is 0-90, and it begins to bo 
(ucconling to Ualton) at 203", dbengaging ut fir<t pure elh« 

Tn alcohol it <IiMi«olve« in all proporlionx. Common etlx 
always contains alcohol, fiy>m wlueh it h easily freed by i^u 
tion in water, as has been already ex]>luuied in a fi>rmer part i 
tluR fiectioD.$ The fbtlowuig table, drawn u]> by Mr. Daltoi 
shows the specific gravity of various mixlurt« of ether an 





* tt. 

ElhB. Alolwl. 


lOO + 


. 0-7*20 

40 -1- 60 . 

. 0-792 

90 + 

10 . 

. 0-732 

30 + 70 . 

. 0-804 

80 + 

20 . 

. 0-744 

20 + SO . 

. 0-816 

70 + 

30 . 

. 0-756 

10 + M . 

. 0-828 

60 + 

40 . 

. 0-768 

+ 100 . 

. 0-830 

50 + 

50 . 

. 0-780 

If we agitata' small pieces of phosphorxLs at tlie ttftnpcmtur 
of 60° in ctlier fr«e from alcohol, we obmin a tmnqiarcil 

i.* Nicholaon'a Journal, xxi 3(3. 

+ Cniickihonks, Nicholnoti'ii Jour. v. 805. | Mwn. Piiris, 1748, p. 

^ A lolulicm of 1 |inrt clher in S or 3 porta of alcutiol coimlitulei Hi 
innnn'i 'i^iior imodf/niii viinrrnJii, or Iloft'mnnn'* iMte ittopt, iO CDtimon 
uiiijiloTed in llsiiiiiQr in ncrvoiu allccliaiix. 


fbeloHrlan solution, containing nc'l* *'f ''^ weiglil of phnsphonis. "^^ '"■ 
But ctlicr, if it contain* alcohol, (ll<«ol?i?a only j^^th of itfl 
T«)glil of ptio«{>h»nts. I'lie M>liKioii siiiellA of pliwiphoms, and 
hiraft wlu-n droppvd into boilinf; wuUt. Wht-n inixMl tt-ith 
llooliol it tivoumra tailk)', owing to tbv prcdpilutJon of the 

KtliT wu» suppofipd incapable of acting on sulphur, except Uj^IuT 
i Vhen both vere in the state of >-apoiir, according to the expe- 
iBDents of Laui^^ais; but Vavts luu shown that a §olution 
may be obtmii«d by digcvting flotrera of sulphur in cold otlier, ^M 

ind that tlieKolvcnl power of the ether is promo t<'il by cxpoMire ^M 

Id the iigiit. By a month 'n digc^ilion he dissolved nearly one ^M 

pit of nilphur in I'i of sulphuric etlier; the solution uiw nearly ^M 

vAaulem, biU lud ihe taste and smell of sulphuretted hydrogi'n.f ^ 

Ether disMUes iodiue, luid the -solutiuii lias a brown colour, x-^i^ 
h ifinolTes also the ddoride^ of carbon. 

It abmrbR 2*17 times it« volume of cnrbonk acid gas, 5 times 
iu roluine of cyanogen gtM, 0-lS volume of azotic gn». Ammo- 
riial gM, and liydroeyunic acid vnpour, arc aUo ulMorbed by 
H b ooniklcrablc quantitj*. It absorbs muriatic acid gM, and 
JiHalms in liquid muriatic acid without the formation of muri- 
>ttr ether. Fluositicic acid ga.<t is absorbed by it abundantly. 

FUhcr dissolves abnut 4 per cent, nf its weight of hydrated iwuui, 
pobih. 'Jlie solution ts yellonnMh, and ratlier heavier tlian 

It dtmolvM M-ventl of the metallic sulphurete, chlorides, hro- 1!^^" 
aides, and iodides ; but always to a less extent than alcohol 
dort. In general these solutions undergo speedy decompos!- 
liaii, acids being genenit«<L 

II ia im exL-dlent solvent of chromic acid. 

It disMlves ^tb of its weight of nilraU' of unuiium : both the 
eUoridcH of iron are tidten up by it. 'Hie solution of the se»- 
ipiichloride is dark yellow and vcrj' acid. \\'ln-n wo agitate 
ether with an aqueous solution of those chlorides, and leave the 
li<iuid at resti the ether >>eparates and carrie« with it all the 
inn chlorides. It has l>cen long known that ether separates in 
the nunc way tlie cht<iri<le of gohl from tt-it mpieous solution. 
It dtHolres a lillh) uf tlie chloride of cobalt, and acquires a sky 
blue colour. Doth chlorides of copper are diasolre^d by it tii 
hiibU quantity. 

It diMolres from jtli to jtli of its weight of corrosive 

• Bragmtdli : Ami. de Chlm. xxiv. 73. 
t Oefalen's Jour. it. »7. t BouUaj. 

It. X 





c^ <■*■ Hiblimato, and when n^it»tvd witli iho aqueous ml uti on 

roMve <iul>timate it abstracts it from the water. Aecontin^ 
Vogfl, when this solution is exposed to iltc light it dcpositcfl 
calomel, but with 1>t, J. I)itvy thiit (le^MMition did not take 
place. He found tht specific tfravily of ether witiinitod with 
comwive •tiiblimutc to be 1*08. It is a good solvent of cliluridc 
of platinum. 

It dissolves Oxalic acid: in small quantity. 
Konnic acid. 

Acetic acid; se[>anit«d by water. 
Mecnnic acid. 
Gallic acid. 

nenzoicacid; j'jih of ita weight. 
Camphoric add; ^ at 47^ 
Suberic ncid; ^at39%^atS0*,^at95<'. Braiidc«.J 
Cholemerie add. 
Ambreic acid. 
Stearic; 0*1 '2 part. 

Oleic ; I part in S^ 1 of bailing etlirr. 
Hu lyric. 

Ricinic : in I ether at 64'. 
Tiie pyroncids. 
Finally, sulphuric ether combines readily witli all llie other 
ethers ; it dissolves also pyroacetic and pyroxylic spirits, vola- 
tile oils, fatd, many resins, and not a few both vegetable and 
Ulimal bodies which it would be needless to enumerate kerftj 
It dissolves also several fixed oils and several bitumens, V 

It will be proper now to make a few remarks respecting the 
tlieory of etlierifi cation, wiiich hiis engaged a good deal of the 
attention of cliemists. To uud.'r!»ian<l the suliject we must 
attend to what takes place when sulphuric acid iind alcohol i 
mixed, and the products successively evolved. Upon 
hruiicli of the subject much light has l>een thrown hy 
expcrimcnU of Mr. Hennell.* 

• PhtL IVaiu. IB28, p. 36S. 


8UIJ>llfHIC CTHKK. ^^^^^^1 307 

When equal wtfi^tibt of ulrohol anil sulphuric acid arc mixwi ^^'"- 
I together wiilrout tlie application of any heat, uboul one-half of 
tUii- wlphiiric actd is eonverltvl into Milphovinie, which (as has 
[btrn cx]ikujie<l in a prvcwliiii; part of tliit vuliiim.') '» a com- 
I pound of 

2 atuins Bulpburic acH, 
1 atom tetarlo-carbo-hydro^n. 
^ten thiit mixture 14 dutiJlcd ether in formed, and passe* orcr 
uiUi the reeeiver, while the sul|)hovinic acid disappears. It 
TDultl »p|>car from tJits that tiie etlier originates from ike tetarto~ 
wha^lfdro^eH in the Miilphovinic acid. Thb substance, in order 
tt be t-onvertcil into ether, rec)uirc8 only to quit tlto sulphuric 
wd uiil) which it n-a« previously combined, and tu unite with 
u atom of u-ntor in its stead. The action of heat seems to 
produce this effect in coiueciuence of llie great difference 
ntween thv volatility of sulphuric nckl and aqueous vapour. 
IV sulphuric acid tliuK set at liberty acts upon u new portion 
tfilie alcohol, douhllcMM converting it into sulphonnic aci<l« 
■Ueh the heat afterwanls dii-ompoHcs. Tluit this view of the 
■Igect is correct, seems prove<l by the direct csperiments of 
Mr. Ilennell, who mixed a portion of sulpboyinate of potash 
nth Uie quitntity of sulphuric acid requisite (o saturate the f>ut- 
■ih, sod distiUiug the mixture, a qiumcily of etiier n-as obtained. 
I In preparing ether tlie ebullition is contuiued tilt white 
Vfepours make ilieir appearance, an<I the lunell of sulphurous 
arid is perceive<l. 'Pie receiver miiTit (lien be elmiiKed, for no 
SMfC ellii-r will Ik- formed imless more alcohol be added to th« 
aeM mixture. If we still continue the heat after eluLngingthc 
r*eeiver, sulphurous acid b produced abundantly, and a yel- 
lowislt liquid comes over quite ditfereiit from etlier. Ifwemix 
il with a sufficient quantity of liquid potJL^h, to saturate the 
solphurouH acid which it contiiins, and tlieii a])ply heat enough 
to drive off tlie little ctJier which it mny contain, what hi called 
tbr mxet oUqfui/K will rcmuiii flouting on the surface of the 
watery liquid, Thia liquid may be obtiuncd In greater abun- 
dniiOe by distilling a mixture of equal volumes of alcohol and 
•ulpburic acid, and purifying the product by iigitating it with 
N weak solution of carbonate of potash. Thus obtjiiucil it has 
a yellow colour, a fragrant smell, a bittertsh and pungent taste, 
and a specific gravity of )-0C0. It does not mix with ether, 
but combines with alotrhol, and it |)roduces no cLinge on vege- 
table blues. Mr. Mennell has shnwn by sntis&ctory experi- 
racntA that oil of wine is n compound of 


.'W?' >irr&Ai comocxDS. 

V'ua X k- 'an. nu-rUfejf <c :iie wajto-cwbo-bydrogen eepar- 
ia» T-im z 31 1 5ry>Sh3nf mthl and the tnl of wine becomea 
sLiitiur-mi: tMsiL W; ^im ±nE likk bor different tetarto-catbo- 
I'lrivi^ >F frioi fuft&biucv: iW Atmer beio^ a 8(did and (be 

jf -w^ VEUH -iL. fc T=&e viii a soffident quantity of water, 
T ¥ .Mt««rM. aai mlcibi'rsae aa(L and tbe excen of tetaito- 
•KW-a.7>it*nc:Ri. if WTuneetf ia i^ ftem of a bright amber cot 
fluw 111. JC-SK .-im!a!CAacy«'<a»0raiL Its qiedfic giBvity ii 
f^h I~ > seuiujiu! ii VIM?. Tvry solable in etlier, and smne- 
■wrats vat <w :ii iu.-Jiiui. Ii ;«:*«< vrtb a brilliant flame, throw- 
31^ ^ mam ."viwiL. Wintx Molyied by red-hot oxide of 
j»ini«r. X fiv« t»n si^jr^r «^]al it>ii»t of carbon and hy d rogen. 

!rWe ^%.. iK -v^jcs. vt A?e dueflv indebted to Mr. Hien- 
Ktl, vtL itBtnat at » JccnKSKv tae aecnncr of the theory of 
tehrrdKaom- i»c ^cwksia: :-r Fooiaor and Vmuqnelina and 

n«^ oiJifBuraF «v» ^c cobiMi (hat tbe imly difference 
Jvnnnni iltxihji joii iOftc » tasix iW tbrmer contains twice aa 
soco. 'vaofT a» :itc asstc. Sf^phmic acid aria umply 1^ 
jA!C!k.-ca^ m^i-JiLi -•c z'lt water •» tbe alcohol ; the qiirit thiu 
iM«ali«!u£v« .'if ixi>i«f^:^« x-csofether. This tfaewy poMcia 
a^ sKfct^ ..>c iXTT^mfi ^ijzi^-xiij, and when it was advanced it 
jpc«fttKC •i.rt>;c^\:tit:ai^ji!. I: bas been lately supported byan 
edaSxw «■: I.-; ix-t^jnn^s by I>unK and BooUay.' But I 
•MOMLAfr i: !-.' Sf -^ixzifv^Ktary m eater iqxm any difwmwinn, 
Sn-www a«r rww.'CLZj: » anerly at variance with the whole 

I; » t.-vn:c:i'y tru^ zht: «:her contains only half the water 
thai e\csai^ ia A^.^'C\U : but it t$ no less so that the other oon- 
:«ti*ie«t k4' <^r W sv>t t^ suae with tbe cmnbustible oonati- 
tiMttt «4' amX'^*!. Ai<wh>L>i is a <«Bq>ouod <rf' 

1 aiMEt water. 

I aivoi iCe&ani cas. 

1 aMcB araner. 

1 alum letano-carbo-bydrogen. 
QMbM fW it an efaetic duid. tetarto-carbo-hydn^^ a liquid 
Wntti Mjr ; vMant ^ b a compound of 

« de Hits, xxxri CM. 



f Q aUims «irtM>ii, 

\ 2 auims liy(lr«>^ii. 
Wbile t«twto-ov1>o-liy(lrog«ti is a compount! of 

C 4 a(t>ni» cvboii, 

(^ 4 iitonM hydrogen. 
He eflipct produced by the sulphuric add on tho alcohol \s to 
Mparale the ole6anl gas from the water with ivltich k was 
Wfore in comhitialioii. And it is ant unlikely that the strong 
affinity of fiiilpliuric ncid for water may contrihute to this effect. 
On« portiiin iif llie tuilphuric acid inay combine with the olefiiint 
gn, wtd nnotht^r with tlio water. Itut the olefiitiil ffMs when 
&u* united to the acid undergoes a farther raodilication : two 
MOOM of it are combined togetJier to constitute one atom of 
IHirto-carbo- hydrogen. How tbtN new comhination takes place 
tunot at prcftcnt be ^■xpluiucd, a.i we luive no exact notions 
npitn wlwt the nuiny different mod tlicjit ions of carbo-hydrogcn 
■1 prownl known depend. But it uppean from the experi- 
■tnts of Mr. Ilennell that we can extract either ether oralco- 
M si pleasure from sulphovinic add. When dry Mtlpliovinatc 
tt putesli n-as mixed with ttie i|uautity of sul]>huric acid neces- 
•ry to Hntiirate the poIiMh, elht-r wiis <ditainfd ; but when the 
■It, prrvioudy dis^olvMl in wiitur, win inixeil with the Mime 
qnuitity of sulphuric acid, imd distilled, alcohol wus obbiined. 
In tlie former case the combiri:iti»n consisted of an atom of 
nier and an atom of tetarto-carbo-hydrogen, in the latter of an 
ittcn of water and an atom of oletiaitt gas. It apjioars from 
tUi that water and hent )>ave a tendency to convert t«larto- 
(UbcKbydrogen to ulefiant gits. 

We cannot easily explain the cause of the oil of wine being 
drmed when the alcohol is greatly diminished. The charry 
luuer formed s^^eros to act upon the sulphuric ari<l. It pro- 
UilyctintimixuipiantilyorteuirOKairbo-hy^lrogcu, which unites 
«ith llie Hilphovinic aci<l, an<l converts it into <h1 of wine. 

Strt IV. 


Tlie etliers, which I dUliiiguisb by tlie upjiclhition nriti, not 
^naiMc ibcy jiowew acid properties, but because they contain 
u acid lis one of their con»tituent«, are twelve in number, and 
Mamlly divide iheniselvcs into two seU', namely : tliotie tJiat 
MMain a hgdradii or ektirrine asa conslitiieiit, and those nhtch 
ttvtain an ox^ffea acid. The first set comprehends 4 etherx, 
■Mnely : muriatic ettier, eblnric ether, hytlrobromic ether, and 

^^hydiiudic ether. The wcoihI »et coibists of 6 ethers, namely : 


314 szrr&u. coapocsos. 

aitci: etaer. .i^ic niua. atrde mWt, bemok edier, fbnnic 
gaa. arao: eda. asxie MlwrT lad —Be edter. 

A3. aoK A&en ve Bade bv j^fflHng mixtur es of alcohol, 
ami isui Msi v^uei anen onb cack M > eoostitDeaL Some- 
aans IE if ^wi^oaaw a> nU a omm pOTtioo of sulphuric add to 
tW adbnsre. T\eyai«. eaehfOamMl by adding Ae term ether 
tv &« and isnpIuTOi ui in ^K^atioa, and vhidi ezistB initai 

1. Mm^EAtr. 

AArr t&e Aco^vrr af wlpkaric aad nitrie etltera Tirioni 
iOiBpQ vne nude b> oboia c Aer by the action of mnria& 
add <n alraW : bqi i^ acid in in asaal stale is too mod 
£Iii»ii vic& waSK w Kt vtA mock energy iq>on aloAid. It 
was Awncht necvasary. diienriare. in oider to procnie mnriatie 
ccker. to cmplay ch« aotl in a iiidH«l state. Tbe method of 
Bbwintng i&if Mher h as ^ows : 

I^IIe alcuhiol k suantnl viih muratic add gas m free friai 
water as possiUe. The toUowing is the fmmula recommended 
hr Mr. Buse. Ke«p a qondty of coounon salt for an hour 
in a sate o£ fuskm. in «der to defwire it of its water of ctya- 
mlloation. Pat ;3I) pans oi this »It into a tabulated retort, to 
the beak oi wkkk e fined a bent mbe, plunging into a WooUe's 
bottle, eooainin^ 10 parts of ^c<A<^ as stroi^ as po8Bibl& 

Introdotfe into the retort, in snail quantities at a time, 10 
parto of the mtKi cuucentrated sulphuric acid, allowing die 
nNDUMw vr to est.'ape from the bottle containing the akdiol ; 
then distil in a sand bath till the muriatic acid comes orer, 
keepii^ the alcohol botUe as cool as possible during the process. 
The akahol, thus saturaled with acid, is put into a retott, and 
ooe-half of it distilled over. Agitate this portion with an alka- 
line ley, and then decant off tbe ether whk^ swims <hi the ssr- 
fiKe : it usually amounts to 9| parts.* 

Very little was known of the properties of muriatic edier, 
till Gehlen publtsbed a dissertation on the subject in 1804kt 
He empfeyed two pnxresses : 1. the action of the fuming liquor 
of libarius on alcohol ; '2. the process of Basse detailed BboT& 
Both of dtem furnished ether, tbe peculiar properties of which 
W haa deMfibed witb accuracy. Thenard published three dia- 
oa it in I807,| pointed out the simplest process for 

• Joar. da Chn n. 86. f Oefalen'i Jour. iL B(Ml 

I Hmik d'Arow^ b llA, IM^ S37. 


Wf MURIATIC ETiien. 311 

I obtaining it,rxuDtini>dtIip effect of chlorides on iilcoliol,<leacribed ^a^n 
i tlw i>ro|>crtica of muriatic ether in detail, und made a Mt of 
[ K|>eriii]entM to ascertain its constituenu. To the disKertations 
of ihtfMf two chemist* we arc indebtvd ft>r all that we know of 
this very rcraorkablo substaiK-v. 

The prooem recommended by TTicnurd for procuring this fwbbi-mi 
ether ts the Ibliowing: Equal bulks of muriadc acid and alco- 
hol, both as strong as piMsihlc, are put into a retort, of viicli a 
siie n not rauth m<m- ikui to bold ilie mixttire. A fvw gruins 
of iand should be put into the rotort, to prevent the violent 
bailing which might olhcrwise take pitice. From the beak of 
tfce retort a tube passes into a glass jur, twice the size of the 
retort, aiid furnislied with three moutlis. Tliis jar should be 
half filled with water, of the temperature of about 70*. Into 
de Mooiul mouth a straight tube of safety is luted, au<I into the 
lUnl a (ul>e, wbtch passes into a water trough to reci-tvc the 
gat. Mlieii heat 't» ii]>plied, tlie mixture ttoon emits bubblea. 
There passes into the receiver alcohol with acid and water : but 
<kt whole of the ether makes ite escape in the state uf gwt, and 
MBt be received in proper vessels. From 500 grammes of 
Kid Bitd the same hulk of alcohol, between 20 and 90 litres of 
tlhereal gaw are obtainnL (>r, in round numbent, a mixture 
of acid and idcohol, weighini; al>i>ut 30 ounces Iroy, will yield 
between 12*20 and 1830 cubic inches of ethereal gas. 

ThiM gas is colourless, it has a strot^ etliercal smell, and u ("xt^i 
ivei-tisli tMste. It pnxluces no change on tlie infusion of llt- 
Btis, the synip of riiilew, or lime water. It* specific gravity 
Ii3'9l9, that of air being 1. At ibe temperature of tl4' water 
dJMolvea its own bulk of llii« gns. 

W^n exposed to a cold of 52°, it loses its aerial form and 
beeootea llqiiid ether. It may be procured almn<bntly in that 
Mate by padsjttg tt into a dr)' glass jar surrounded witli ice. 
Muriatic ether, in ilM liquid state, is colourlcso like water, very 
litpiiil, Eiiu no action on vi-gi-tal>le blues, and hax the wune Mnell 
and taste as in the gaseous ^tiite. At tlic tem^n-ruture of 41% 
Thrtinrd fiiuinl it of ihe specific gravity 0-874.» It is much 
norv volatile tlum uleuhol, or even sulphuric ether, assuming 
Ibo gMoous stute when not hotter than 64°. None of tJie usual 
%tvbt indicate the presence of any muriatic aei<t. It <loes not 
affect vegetable blues oor give out aeid when agitated with an 

* Bum Dbuincd it of die spftiRe gravity OHtO, and Oehlen of 0-8M. 
Here we nuK canaiiW wdgbt *a a mark of purity. Uence it Is obvioux ili»t 
! anriuie ctber of tlie OMnuu dwailiu VH lew puru thsn TlicDard'9. 


am at aikoliDc ley, or occasion an immpdiatp prvctpitate whrn mixnl 
with nitrate of «ilvrr. Butwlipn brought in contact with a com- 
hiutible it bums readily n-ith a ^7v«i) coloured flame, and a very 

tcoiuid«rabl(! parliofi of muriatic ami is immediatcty diiM'ngt^ed 
in tlir slaU' of rajiour. Thia &ct llifn no xini^tlar wnx fint 
obaerrrd by GcbU-ti: it ban b«;n ninub-ly cxitmint-d by TIkn 
nard. Wben allowed to rvmuii for » long lime in contact with 
an alkali, it do« f^m out a portion of muriatic acid, and it 
slowly produces a precipitate in nitrste of silver after tbe itifan- 
ral of several ilays. and the quantity of precipitate increaMt 
with the time. Hut in neither case is the ether dvcoinpoeed, 
or deprived of the property of giving out muriatic acid wben 

Thenard has endeavoured to ascertain the compoxition of 
muriittic ether. From the qnaiitity of muriatic acid wbieli di»- 
appcur? during its furmation, he lias calculatiil 1 00 ports of 
muriolic <'ther couiaiii -iB-t-l uf acid. Hy mixing determinate 
portions of muriatic ether gas with oxyg<>nga«, firingthe mixture, 
and asoerHuniiig the products, whii^ arc only carbonic arid ami' 
water, he endravourrd to ascertain the proportion of the other 
coiiMttuents. Tlic folloicing is the re«ult of lib exuminatioo : 
CMVMtuin. 29-44 muriatic arid 

a(>-6l carbon 
aS'-ii oxyp'n 
10-64 hydrop-n 


It is generally admitte^l tliat it is a compound of onv atom of 

teliirlo-carbo-hydrogcn and one atom of muriatic acid. Or in 

a slate of vapour il« coii>tituonl!t are 

2 volumes olefumi iriLs = 1-94-1-I4J , . ■ . 

, , . . "^ , rt ,.-^ f condensed into two 

I volume munatic gaa = l-*i847'2> 

volumes; whidi gives '2-I!>-1 for the specific gravity, and llib; 

number duM not difTor mucli from 2-'2 1 !> oliliiined by Tlienard. 

If we admit iti« composition to be so, its cunstitncnts n-ill be 
4 atoms hydrogen . . 0-5 or <!'I5 

4 atoms carbon . . S-0 36*92 

1 atom muriatic acid . . 4-62A 56-93 

8-195 99-99 
These nnmbers appear at first sight to denate enormously firom 
tliMe of Thenanl ; but the difference is only apparent. The 
■ Mem. d'Arcueil, i. Ml. 




CHLOmC ETHEn. 813 

qtuntity of carbon approscbes very nearly to that gireii by *«■ <v. 

Thenard. Wlien we correct tin'! hydrogen by applying the 

nore cmrerl (lata which wc at prcunnt [MMwesA, 'riieiinrd's num- 

ber W)U approach much nearer to 6* 1 H per coiit. titan it (loeN at 

|«eaent. To obtutn the tnic quantity of imirinlic iiciH, wc must 

■dd Uic qiuuility of oxygen and miiriiitic acid found by The- 

Mtd tof^ther, btrcauw the supposed oxygen was deduced from 

u erroneous eittinuitc of the atomic weight of muriatic acid. 

TUi wUI laW tlic amount of ucid to a'2-75 per cent, whicli du^^ 

nut difftT mnch more than 4 per cent, from the calculated 

mmbcr. Even lhi§ itilTcrencp would ditnirii^li, if we wer<- to 

■Ifly the exact data which we now pos«e<>§ to Thcnard's «xp«- 

dawBt. u\>'i ..■ - 

If the preceding estimate of t)M*compnedtion of muriatic ether 

incorrect, it contaiiiM no uiit<.T, and the r«>mhiL<lihle conntilucut 


gnt. For it is a combination of '2 vohimes of ololiant gas and 

I Tolmne of muriatic acid gas combined, and condensed into 2 

a. CMorie Et/ter. 

This compound was first noticed by S<rheel(** and West- lumrr- 
mnb. It lias been unce noticed by diiTcrenl cbciniMs. 
TnsnaiMJorf,! (iehlen,! 'Dicnard,} Berthollel, K Robiquctaiid 
tfllia.^aiid l)e«pretz,»»liave made experiments on itiusucces- 
■ioD, It» iiiiturc has not yet bvvu dctentiiued in a Kati^factory 
tamer; but 1 have noticed it here in order to draw to it the 
Wntion of experimental chemists, It has been frequently 
oAkI Aearg ttturiatic ether, from the sappo^ition tluit the cblo- 
n>e hat lic«» conrerled into nuirialic aci(L 

It was pn-]iarcd by passing ii current of chlorine gaa through F«nutk>a 
ticahol or sulphuric ctlier, till these liquids refiuetl t4),^l)M>rb 
wy more. The alcohol acquired a yellowi»b.igrceii colour, and 
tttniDg smel! of muriatic acid. During the process Home car- 
Iwic acid gRN W9M ev»lvv<l. \\'heD the process was terminated 
>D dy hwkini; fluid had precipitated to the bottom, and when 
^ liquid swimming over it was saturated with potash, an 
•Utioaa) portion of tJus oily malt«r made iiH appearance, 
^'hea ctber \% employed tlie oily matter makoH itM appojtraitce 
■Wn the saluruUtl liquid a mixed »'itb wulcr. It is to tfais 

* Opmcult, ii. 130. t Seberrr's Jour. tii. JTB- 

I OdiUn'* Jour, ii »7. $ >1e>i>. d'AroitfU, I- 147i ii. SA. 

I Ain.<UChiBi.ct(lePhy*.i.t8& 1 ibid \LtW. •* ItmL lu. 497. 


vctnrmAL cx>urovstm. 





oily looldni^ tiAttnet tku tlic name of tJtiorie or Aeairy mK 
a£K; tficrkai been giren. 

It ii a coloniicaB, tkia, oQy looking fluid, hat-iDg, nccordii 
Is Vogci, the specific gTavity of M34. Il is nwre rolatilc 
waicr; hm a mtell Motcwliac wuhr to dvat of nitric ctlirr, an 
■nnalic^ boc, and »oa>rwim biuer taalr. It dues not redden 
fitBDi paper. It is nrj little soluble in water. Voget added 
two drops of It to an ounce of water, and eercia] days etapsed 
brfure tliey disappeared. Ilut in aloobol and sulphuric clhct 
it diasolrea iu any proportion. Wben MBsted by beat it 
•oltrai a Little pbo^pbonis. 

It boms witL a grconisb-ycUow flame, evolving mtir 
■cid. Muriade Mid Ukrw-isc mak*^ its appvaninci' wben 
mbuance b pawfJ through a red-bot porcelain tuW. 

Nothing rery precise has been determined respecting tlie 
compoHition of tiiix etber. Dei^reu oomtders it as a com* 
|m>uik1 of 

I roltUDe chlorine, 
1 Tolune tet3rto-car1>o>hydr(^eD, or 
9 Tolnine)) of oleliant gas. 
But htf ha.t not established tbe truth of this (pinion by a 
sntisfikdory experiments. It is clear from the es|)eriinents 
Robiqurt and Colin, that its properties are essentiiilly diflfert 
front the compound of 1 volume of cbloriiie and I volume of 
(defiant gasi, irhicb I distingui'thed in the Last edition of tiiia 
woric (but improperly) by the name of chloric ether. 

a Hydrvhrvmic ElUar. 

«-as first formed in 16*27 by 

M. ScnilEaa, 
It was prepared by the 


I'his ether «-as nrst formed in 
luu Ikoh ver)' imperfectly examined, 
following process: 

Fortj' parts of aloobol of the specificgTavity 0-827 were put into 
a ■umalitiiiiiilAttNl retort, lolliisone jiiurt of pboi^ibortia wni*iJiiddedt 
and tiiutlly 7 or H piirts ni broiiiini' wen- poured in by little ai 
a time, Every lime that bromine c»me in eonlact with tbe 
phoeiphorus under the alcoliol, a rapid combination took place 
lutd beat u-as proiliicetL Hence hydnibromic acid luid pbos- 

[tliorous ncitl were fonned. The mixture was now distilled 
>y a gentle heal, what csme over being n-ceived in n globnlar 
glass vessel well cooled. This product being mixed witli wuteri 
the hydrubromic ether separated and sutik (<> tlie boltoio. 

Hydrobromic ether thus prepared is culourk-Sit and tnuiepi- 
rent, heavier than water, iiaM a strong ethcrial stnelt, a sharp 



tme, and is very volatile. It ut soluble in alcwhol, from which *»^ >"■ 
it » precipitated by wat«r. It iloe« not alter its colour by " ~ 



4. H^riodic EAer. 

This ether was discovered by M. Gay-Lussac. FIc formvd iiMa^ 
it by mixing together 2 volumcN of atxiolule alcoliol and 1 
Tolune of hydriodie aciil, of the specific gravity 1-7, and dU- 
tiUing in a waler>1«lb. He obtained nn alcoholic liquid per- 
freiiy neutral, colourles*, and limpid. When mixed with water, 
1 liquiii prreipitateil in snudl glol>ulcs, at fir«t milky, hut which 
grvlually became tiansitarent. I'his liquid was hydriodic elber. 
\i\ai remained in the retort was hydriodic acid, much coloured 
if Ml exoeM of iodine. 

SfruUa* formed it by tlieiuune procewa^ that which furnished 
i^robromtc ether; by adding iodide of phoKphorus to aleobol 
ia a bibokUcd retort, and distilling the mixture. The etlier 
!■ wpanted from tlie alcoholic liquid in the ron-ivcr by 


Hydriodic ether, after being well washed vrith water, is per- Prai*"!"* 
fcctly iicuiml. Iti ivloiir is strong, anil, though peculiar, it is 
Mdo^UB to that of oUier etlu^rs. In n few days it acquires a 
Itddiih colour, which does not increase in inte>i»ity. Mercury 
■dpotasli instantly destroy thiscolour by removing the iodine 
t» which it U owing. Its specific grarity, at T'J*. is 1'9'J06, 
It boils at the tempemture of 14tt°|. It iit not infUunmable, 
hM nerely given out pur|>le vapours wben put upon burning 
mU. Potassium may be kept in it witliout alteration. Potash 
1m Dot »\U!t it immediately, neither do nitric, and sulphurous 
mU|i or chlorine. Sulphuric acid renders it instantly brown. 
WImb pOMcd (lirough a reil-hol lube, it w decom{HiMed, an 
bhntnidllB cnrbiirelt<'<l gas io ohl^uiiod, hydriodic aei<l evolvetl, 
■od some charcoal deponited-t 

TUi etlter has not hc4>n annlyxed ; but analogy would Iciu) 
to the opinion tliat it is a compound of 
1 volume iodine vapour, 
1 1-oluroe tetarto-carbo-liydragea» or 
3 volume* of olefiant gas. 
supporitMui its atomic weight will be 19*S76. And tl 
a coraponnd of 10 atoms. 

* Aaa de CKtio. cl dc Phy*. suW. W- t IbU. si*. H^ 

\ Ann. lie Cbiai. sd. US. 

Muriatic, hydrohromic, and liydriodic vtben tire prubnttl 
analogous compounds, consisting of 4 alotnH caHiun and 4 Ktonu 
hydrogen (whether iii the slate of olcfiaiit gas or telarto-carbo- 
hydn^en ia doubtful), united respectively irilh an atom of 
muriatic acid, hydrohromH; acid, and hydriodic acid. They 
contain no tvater, and in UiLt important ctrciunstance differ frota 
llie eight foiluwing ittlieri*, which seem, likt^ sulphuric etJier, to 
ooiitaiii welter u» an ciwentiul constituent. 



5. StdpAocj/anic Etiter. 

Tlii.t elher was iliscovered by M. Uebig, and descrft 
him in a Mcmnir pultli-^hcd in 18'ifl.' It wa»obti»inc<l by di'»- 
tilliiig a mixture of 1 part of isulphocyunoclidc of potassium, S 
partK of sulpliuric acid, and three parts of ether of \he sfiecilK 
gravity 0-848. The product of the distillation being mixed 
with \vater, an oleaginous titjiiid separated, tlie weight of which 
was about ^tbs of that of tlie Kiilphoeyanodide employed. hX, 
first it sM'am on tlie surfoce, but the .-dcohol and sulphuric cthcj 
which it contiiini'd, being removed by n-pcated wiudiiiigs, it 
sunk to the bottom under the form of a colourless or sligbdv^ 
yellowish oil. 1 

It liaH a strong smell of assafcetida or cocblearia oAciiiaUs 
which ad)ien-H (strongly to I'vory titiiig which it touches. It a 
insoluble in water, but it commuiiicutrM Hx odour to tlutt liqiUa 
It has a swoctisli taste, and leaves an impn-ssion of peppermint 
in the mouth. It is very soluble in alcohol and sul|)huTie etlier. 
It burns readily, and gives out fumes of sulphurous aeid. It 
be^ns to boil at 151°, but the boiling point rises to XGX". \t» 
ulcnliolic solution does not pos.-(ess acid ])roperlie&. It i» uut 
d«(N>mpOSttd «itlier by puliMh or iinimonin. J 

Potassium placed in coutuct with it, after bi;ing rcctiRed frxMV 
dry chloride of calcium, preserves its lustre for some time ; but 
if heat be applied it beeomcs covered with n yellow crust eol 
bltf in water, and precipitating peroxide of iron red. Kenc 
the crust wait sulphocyanodide of potassium. 

Nitric acid act» upon it with great violence, producing even 
combiuition. Much deutoxide of luote i^ given out, aiwl tli« 
remaining lit{uid contains sulphuric acid, 'lliis ether ^isorU 
chlorine abundantly, sulphuretted hydn^en gas is given ouC 
and die smell of chloride of Mulpliur becomes sensible. If we 
add water, and continue to pass cldorine gns, more of it i 

' Ann. de Chim. ct dc Ph)^, xlL 20;;. 

diwbed, and tlie xraell of c)il<>ri<lo of cj-anogcn becomes per- 
etpdbte. The lii|iiid it now ncid, and precipitates bnrjtossalu. 

IlxKnc (Us^dIvcs ivndily in itiia elli^r. Sulpbur is aUo very 
ululilr bi it if we elevate tlie temfK-niture. 'I'tie iiatno renuiTfc 
iji|ili<s to pliosplioms. 

TWuj^h (lit'i ellier luw not b«(>n unalyit'd, yet it bi «vi<li>nt 
tUtilcnu tains sulphocyiuiagi'n, unci lliat it is ilratitutc of wnter, 
ind aunluf^ InuLt to the opinion that it is a compound of I 
Blfifnuit paniclr of sulphocyanogen, and 1 integrant particle 
of letarto-ou-bo-bydrogen united together. 

6. Nitric Ethtr, 

S'ltric cthrr ik fintt m<-ntioni.-ii in iin c|mtle vrniten by KunkrI iummt. 
loVoi(rlit, and pul)li»licd in Ift8l ;* itnt iiu altentiuti wuh piitd 
b it by sticcceitinj^ chemists till it wwt ditimvcred n m'coimI time 
I7 Nnvier in I74'^.f and a third lime by Setiuxtiani in I746.{ 

TW nicllio<i of pr<^|lu^illf; it, pro)>a«ed by Navier, wa^i tblt : 
Tnire parlD of aleobol are put into a strong bottle, which b 
b^ tumninded with water, or mthcr with ice; i-ighl paru of 
■ilrie acid ore poured in at intervuls tlie mixture b^ing agitated 
<Afr «vcry addition. The bottle is liicn well corked, and tltu 
CDfk secured by leather. Etber gmdwdly foniu ut tlie Nurfiicc 
rf tic liquid. After five or six days, when tl»c formation a 
Nppoaeil to be over, the cork is to be pierced with a itecdie, 
loijlow a quantity of nitrous (pis to CHcapc, wbicb would otlicr- 
*iw carry tlie ether along with it. The cork in then to be 
'nvn; tbe whole liquid is to be poured into u fiiiincl, and by 
>Nm of (he fingt-r the liquid below is allowed to run out while 
Aether i« relJiined. 

Tliit mcthot) in MKuewhat haxardous: for tlie quantity of 
■feoiis ga« ei'oK'e<l i" ko great as of^n to burnt the bottle. 
Dr. BlMk kubslitutcd in place of it a very ing4>nious procois. 
Bt put into a glM« phiid the pro)H'r quantity of nitric aci<l ; 
*W this was poured gently a xtratum of wntcr, and the alco- 
M was poured over all. Thus there were tlirec strau of 
Squid* in the veiwel : tlie acid lowermost, and tlic alcohol upper- 
Boit, separated ^in each other by the water. The acid and 
*k>tM)l gradually coinbint-d with tlie water, and coming into 

E acted on each other without violence ; and lltiu tbe 
IS farmed without rbk. 
e baa given another process for obtidning altric etber 

*-8|ibtolii MnUft 8|uriiuin Viiu una Acido. 

f Hon. Pit. 17^4. t !>>•«■ >le Niiro, ll-W. 



excei^lingly tedioiia, but not attcndcil wiUi any ritik. Tli«l 
alcohol is put into a tubulated retort, to which u lar^o r«C(>iv4>x 
I« luted ; ('gth part of nitric acid U to be added every four htture, 
drop by drop, till it umounts u» about lialf the weight of alco-. 
Lot i ilien the mixture becomes hot, iuid tlie ether pasnea over 
into tlii* receiver. After this a little mure nitric arid b to be 
lidded every morniiig and evening. Ether ffTiuIiislly (utmn oo 
ito tiur&ce. The aci<l is to be added till it hUs dowti tu 
bottom of tlic retort in the fonn of ^reen fi^lobules, indicad 
the j>errect Baturation of the acid with tiitroiia gas. This b a 
proof that no more ether will be formed 

Various other metbods of preparing nitrous ether have l»ccn 
proposed by chomists, «» the distillation of a mixture of sulphuric 
Acid, nitre, alcohol, &c. Hut the procetw preferred by arlasta 
is that of Chaptal as corrected by Proust. A large retort m 
luted to a glass globular vessel funttshed with a tube of safety* 
From this glol>c a lube passes to a seooiid, likewise furnished 
with a tube of safety ; and to this last vessel b connected lliree 
Woolfe's bottles in tlie usual way, which must be luilf full of 
alcohol. A mixture of 3'2 parts of alcohol and 24 of acid, of 
the specific gravity I '3, is put into the retort. n>e heat of a 
cbafiing di&h ia applied, and removed as soon a» tlie eflerre** 
oenoe begins. The greatest part of the ether b detained by 
lliealoDhol in the linit Woolfi^'s bottle. This mixture is to b« 
«ator«teiI willi an alkali, and the ether separated by distillation." 

These processes are all of thom so defective and complicated, 
tluil little precise knowledge was acquired of nilric ether, till 
'llienartl undertook an investigation of it in 1807. HedisiilU-d 
a mixture of alcohol and nitric aeid, and rarvfully collected aiid 
examined all the ])rudueti« both liquid and gaseous. A cod- 
aidemble part of the etJier formed he found made its en-ape in 
the gaseous form, while the litpiid in the receiver, hitlierto con- 
sidered nitric ether, was a mixture of alcolml, water, etWr, 
nitroux, and acetic acids. These results led him to tlie follow- 
ing method of procuring pure nitric ether: 



" Promt, Ann. Je Cliim. xlii. S(i2. — BruBimlelli has propoied the folli 
tnfi; nipihod : but I lliid that the proportion orclhcr obinincd by rl a nmi 
•miiUcr thnn the other procckir*, though BruKiintcUi nffinns the revsm 
Put ui ounrtofiuptr into n retort, nnd pour orer ittwoouocciofBlooboL 
I.iit« to it n Jargf rrceiver \kiih ulipa of paper, unJ then iidd (^eouncaoT 
nilric aclij. The uigur Is diatolTcd, the minture boils, and (he ether pxin 
ovwpure.eijuBl inwirighl to ihcnlcohnl. See Jotir.dr Clitm. iiies. Pw- 
hup* my want of complete (ucrcx* wu oning tu the uk of n *tn>nger tcid 
than that employed by Briignatelli. 

Equal woiglits of idcohot ami nitric aci<l, of the specific gravity »•"■ ^■ 
1 i?d3, were ]iut into a retorL To the beak of tb« retort was ,„nti«i«i" 
liK«d n glum tiilie, wliich wa« jilungetl co the bottom of a long 
nnrow gliiw J«r half filled willi a saturated solution of common 
ailt ill water. From the top of thi» jjir jmssinI anotlier tube, 
«kicli went to the bottom of another ttimilar jiir, likewise liulf 
filM with a solution of common suit. In this manner five 
nailiir jars were connected with each other, eaeli half filled with 
■ atUinited milntion of eominon mU. l-'roni tlie last a tube 
{Mwd to u WBter trougli to receive tlie gaiieotiA productii in 
paper Jnn. Ench of these five jars wus stirroiiiidiHl witit a 
aixture of snow and salt to keep it as cool t» poiwiifle. A 
BMienite beat beingapptied to the retort a violent effen'escence 
btgan. It was found tiece«<nry to withdraw the fire, and even 
to noisten the oiit«i<le of the rvtort wttJi water, in order to pte- 
nmt the vessels Grom bursting. The guseous matter evolved 
m thus forced to pass through the diiTcrent jars continuing ttie 
Mtnraon salt solution, and there it deposited the greatest port 
rf it« ether. The ether was found floating on tlie surface of 
tht Mlutions in each, but the greatest part of it in the first jar. 
It wu nepanted ; and to free it fr<nn the nitrous and acctie 
adds wit)) which it was o&nlanitnated, it was agitated in » close 
pbU with a sufficient quantity of chalk, till it ceased to pro- 
duce any eluuige on vegetable bluea. It was tlien decunted otT. 
Hk properties of this ether are iw follows : 

It haa a slightly yellow colour, and a very strong ethereal Pnvaia. 
i tdonr. Its taste is strong and quite peculiar. It is nitlier 

■vitr than alcohol, but much more volatile than sulphuric 
tllier> HciKt^ it only moiislens bodJCK for a moment, and pro- 
duees a ver)' considerable degree of cold by its evaporation. 
The beat of the liaiid is sufficient to set it a bailing. 

The Kpecific gravity of its vapour, as determined by Duman 
ud Boultay, is '2-(ti7. that of air being reckoned unity.* 

It is lighter than waier, ami requires 48 parts of th»t liquid 
to dJMolve it, and communicates to it an odour like tliat of 
Ipples. It dissolves in aluohul in every proportion. It burns 
tery brilliantly with a white tl;une like sulphuric ellier. When 
kept for some time, both nitrous and acetic ucids are formed in 
IL The same acids are evolved if tlie ether is hented, or if it 
he agitated witli water. When brought in contact with a little 
of these adds, it iikstantly absorbs them, and acquires the pro- 
perty of converting vegetable blues into red. 

■ Ann. dc Chicn. ot de Ph^s. uuvU. 31. 



;^chi^tiL When broiij^bt in contact with dculoxido of azote, 
otiier ga*, at tlic tompomture of 70°, it instaiKly qiiintu] 
bulk, being cnnverb-d into ra|>uur. At iluit leinjHTat 
vupoiir is capable of supportinfr u column of invrciiry 
incites high. At tlie tcmpcratHrc of 70% nnd when tlK 
meter Htantbt m QO inches, it is liquid : but if we increi 
;1ieat or diminixh the pressure, it asHumc^ the state of v 
It is much more 4'lai'tic i}iaii sulphuric eiber. At tin- tei 
hire of 70°, tlic vapour of sulphuric oiIht is t«[iiiiblc ( 
tnining a column of mcrniry only 16 inches bigb. 

It viw subjected to a careful anulysix by Tbenurd, by p 
it through a red-hot porcelain tube, nnd exiunining th 
BuhHtaiiceA evolved. They were water, carbonic ncid, du 
oil, hikI a considerable quantity of pis which contained 
and nitrous gtis, and a heavy inflammable air, which <leb 
with oxygen, and yielded curbaiiic acid and water. ^ 
ammonia appeared alj>o to li»vo been pnxlucni. By eatil 
4he weight of each of tlicMc eubstance» and tbeir consdl 
lienard concluded, that 100 ]>iirt» of nitric ether wai 
pomcd of 

48*53 oxygen 

28-43 carbon 

14-49 iiy.ote 
■1"^ fr54 hydrogen 


In 182B it was subjected to a new minlyMis by 

and Biiullny, by |m4^tig it through red-hot bhickoxidec 

per, am) collecting tlie azotic gas, carbonic acid gas, and 

ivvA, un<l estimating tin- oxygen hy subtracting the 

weight from abstraction of oxygen from tin; black oxid< 

the oxygen in the carbonic ucid and water formed. Tlic 

of four different un^lyMcs nuule in this w-ay witli great can 

the constituents of the ether as follows : .> 

Carbon . . 32-69 

Azote . . tS-00 

t Hydrogen . . 6-83 

Oxygen . . 41-46 

'Now these respective weights are proportional to 

• Mem. a'Artuail, 1. 380. f Ann. ilc Chim. oi dc Phju. sxxfjj 


4-02 nUHiM c»H>on, 
I atom luotv, 
5*06 atoms hydrogen, 
3*33 Atoms osyg;eii, 
ive no hesitation, diereforc, in convtkring the con* 

4 atoms cartmii, 
A atonic hydrogen, 
1 atom juu>t«, 
4 atoms oxy^n. 
Now these are equivalent to 


iitom u-tairto^rbo-bydropen S ] *""^' f '[*"' 

' " J 4 atoms hydrogen, 

Utomwat«r . . T 1 atom hydrogen, 

(_ 1 atom oxygen . 

I atom hyponitrous acid S \ »**^ '^'«' 

(_ y atoms oxygen. 

B«l lutpburic ether b a com|>oiuid of I atom tetarto-carbo- 

bfdragen ukI one atom of wiUer. We may, dierefore, oon- 

fUiT nilrk ether an a compound of 

I ulom sulphuric ether, 

1 atom bypoiiitrous add. 

I* atomic weight, tlierefore, must be 8-25. 

Let IB see how nearly tlie Rpecific grarity of the vapour of 

JtaBLSther tallys witli this view of m constitution. We 

'WINhi that this specific gravity was found to be 2-627. 4 

I roL sulphuric ether vapour . . 2*5694 

1 roL hyponitrous vapour . 2-6388* 


urn eon*ider it as a compound of 1 rolume'of sulphuric ether 
*>{*oar, attd I voliune of hyixtiiitrotui acid vapour combined 
^ptlier without any condensation of volume mhatevcr, tlic 
^tific gravity of it» vapour would be 2-60415, for that is the 
■<M tfetween the specific gravity of sulphuric ether vapour 
Withat of byponitrous acid i-apour. Kow 2*60415 differs from 
'^i the specific gravity as determined by Dumas and CouUay 
"T Ins than one per cent There seems, therefore, no reason 
^ i^Milate about the view of the conittitution of tliis ether first 

*Ot«ui»cd bj muliipljing 4*75 (ihcntomk wdgbt ofb]r|Mimin>iu acid 
ir. Y 



''''*^"'- siiggoHted by lUese chemists; namely, that it is u compound < 
sn atom of sulphuric vtlicr, with »n atom of hyponitrous aci<). 




7. Ostiiif EtMer. 

This etliM wjut first noticed hy Bcr^an,*aiid afHrwatdB l>y 
Thciiurdf anil Bauhof,]; More iaU^ly it luw been acciintlely 
pxamiiiod luid analysed by l)iimn.« tind Boiillny.§ 

The process of Dnmew iinil Honllay, by wliich they procured 
this ether readily mid in ubiindaiic«>, wait us follows : A mixture 
of 1 part alcohol, 1 part binoxidatc of potasb, and 2 parts of 
sulphuric acid, was distilled. There came over Rntt alcohol, 
then sulphimc ether, aiid at hsi aii uleaj^inous liquid, which 
collected at the bottom nf the receiver, Tlic distillation may 
be continued till nil the alcoliol ]i-m been driven out of tho 
retort. The last portioiw are ri(.•he^fl in oxalic ether. The 
oleaginou'f liquid i* the utie which contains lliat liquid. The 
alcohol floating on its Hurfuce was removed by deca»tation, and 
the oily liquid was poured intoa tall jarcoiinunliigwaler. At 
first the oily liquid floated on the surface, but in profwrlJoti as 
the sulphuric etiier whidi tt-as mixed with It oTiponited, it fell 
in lar^c drops to the bottom of th« vcnel. If wc pour the alco- 
holic liquid into the retort, i>r add a new dose of alcohol, more 
oxalic ether will come over. A third dose of alcohol will still 
yield it, but in lests quantity. 

T)ie oxalic ether tlius obtained was add, and it couLtlned 
water, alcohol, and sul|)huric ether. To purify it it wil^ boiled 
with powdered litliar^e, uiul the boiling wns continued till the 
boiling point, which wa» at first 1 94'. rose as high as ^ii". By 
continuing tliis heat the whole water, ateohol, and sulphurio 
etlier, evaporated, while the itncombined add united witli tlie 
litliarge and was removed. The oxalic ether wmt now poured 
Into a dry retort and distilled over. 

Its jiropertJes, when thus purified, arc as follows : It t« an 
oleaginou!) liquid having a i<rpedfic gravity of 1-0929 at the 
temperature of 45*'-5. It boils at 363°. Its smell is an>> 
natlc, but hus something analogous to that of girlie or nho** 

The specific gravity of the vapour of oxalic ether, as deter- 
mined by Dumas and Boulhiy, is 5'087, that of air bcliy 
reckoned unity. 

• Opuiculo, i. SM. + Mem. JArcu^, iL 1 1. 

I Srhwelgger'B Jour. xi\. 3(W. 

S Ann. dc Cbiin. ct dc !%)-«. xxxvU, SI. 



^^^H OXALIC etheh. 8n 

^rnnB analyze*) a gtfiAt ntimber of tiine« by DtimaS and ***■ >"■ 

Boullay, by tW wmo procen <u they followed in the Biialyiiia 
Bp( nitrotu other, Tlie results were its followB : 
■ Iton. 

I Carbon 4U-6 1 . . 48-D5 . . 49*28 cii<biwiii«i. 

Oxygen . . 49-77 . . .14-09 . . *J-93 

Hydrogen . 6-62 . . 6-96 . . 6-79 

■ lonoo 100-00 lOo-no fl 

K TVtse DUtnbeni ut proportionahte to ^M 

I 5*984 ntoms carbon, ^| 

^^^^^B 4 atoma oxygen, H 

H|P^P 4-d4 atoms hydrogen. H 

FnGobr^atu firom tliis tliat the true coniititucnt« must be H 

H 6 atom<< carbon, ^M 

I 4 atom.t oxygett, H 

I 5 &tom<< hydrogen. 

Domu and Boullay showed tliat oxalic acid exists as a conitti- 
lOMt of thifl ether by actiuJly separating it Now, an atom of 
*alic add is ooinposed of 
I S atonra carbon, 

■ 9 alomti oxygen. 

P If *e subtract these ntonu from the oonslituenta of oxolk etiier, 
Afre remain 

4 atoms carbon, 

5 atoms hydrogen, 
1 atom oxygen. 

Sur, these are the vtTy constituents of sulphuric ether, which, 
"■* have seen before, may be resolved into 

I atom water . . ? 1 »**» h^&^"> 

(_ I atom oxygen. 

I atom tetarto-caibo-Iivdroiren J ' ' , * ' 

■* J 4 atoms carbon. 

An it appears that an integrant particle of oxalic ether is a 

Mnpound of 1 atom of oxalic acid and one atom of sulphuric 

tW, so tliat its atomic weight i« 9-125, 

Let ufl see how this constitution ivill agree with the specific 

pwitjr of Uie vapour of oxaltc ctlicr as determined by Duma» 

"•iBoollay. Tlie rfadcrwill recollect tliat it is 5'0$7. Now, 

•^ ^tciHc gmvily of Nulphuric cllicr rapour i« 2-6694, and 

••t if oxalic acid vapour must be 2'5,* We have therefore 

* Ubtaiaed by mullijJying its sconiio wcaght by (H&&S- 



1 Toldme of sulphuric etber . 
I volume of oxalic acid vapour 


.'i'0fi!>4 agrees so nearly with n'087, the experimental result, 
that there scema no reuson to iloubt tiiut tlii.s ellier in die fttate | 
of vapour b a compound of I volume of sulphuric etfacr and I 
volume of oxalic acid vapour, condensed into I volume. 
Ansi/iii. Dunia.'i iind Itoullay analy/.cd this rthcr by mcuns of pota»li> 

7-348 parts of oxalic ether left for 24 hours m contact with a 
strong solution of cinistic pola^li were coinpleiety decomposed- 
It was now introduced into u retort contiiiniiij; dry CKbonateof 
potash, and diBtille<l 1 8'277 parts of a liquid were obtained of 
the specific gravity 0-970 at 50°. So that it containctl 0-'2b of 
ahsolute nlcohol. IIcucc 100 parts of oxalic ether yielded 
62-18 parts of absolute ukoliol. From the same qtuinlitj' ofj 
the ether 4898 parts of oxalic acid were obtained. Thus the I 
constituents from tliis mode of analysis were (supposing looj 
parts of oxalic ether) 

Oxniic acid . . 48-98 
Alcohol . . . 62-18 


It may at first sight seem enigmatJcd thai the weight of Ot« 
conslituentjt should exceed that of the ether by II - 1 (E per cenL 
llii- rciL'^on is, tliat the snlphuric ether in the oxalic ether 
became alcohol during tlie decomposition. The sulphuric etlier 
in 100 parts of oxalic ether was 51-02. Now 51-02 prw of 
Bidphuric ether if converted into alcohol would become alxnit 
60 part^ which come;^ very nearly to the quanlity of ulcoliol 
obtained in the experiment of Dumas and Boulluy above 

W'heii a current of smmoniacul gas was passed through 
I oxalic ether it underwent decomposition, but in a way very 
different from what was expected. One-half of tJie tetaurt<H 
car bo-hydrogen of the t«ulpliuric elfaer entered into combituUton 
willi the oxalic acid, and formed a new acid, similar in ite iiatore 
to tlie aulphovinic acid, and which tliercfore may b« called 
oxaiovinie ocirf. This new acid pOKsesscs a saturstiiig power 
only half a<< great ns (Iiat of oxalic aciiL It was saturated with 
amraonia. IIenc4> the oxalovinalc of anunoniu formed was a 
compound of 



Oxalo>-tnic acid . . 12-5 or two stoma, sm. tv. 

Amtnonia ■ . > 2*125 or oiic atom. 

yrht oth«r half of (he lecarto-cartio-tiydro^cii ri-cluccil to the 
TrUc ofolefiaiit gas imite<1 tn atk ati>m of mtiIit iind i-wii.tiitiit^Hl 
alcohol, wliidi vs» (.-uxily HO|iurnti'd by distil latioit, wid ito quan- 
tity drU'nninrd. 100 juarls of oxalic ether treated in this way 
f»« out ai'48 parts of aJcoliol, which U only the half of the 
^pulity furnished by it when it b decoinpDited by potash.' 

e. Jcetic EOuT. 
Hila ether w-a* diiwovercd by thtr Count de Lauraguniti in mtiry. 
l*59.f He (Stained it by distiting a mixture of acetic acid 
nd ilcobtd, with tJie tuune jirecautions as are employed in the 
^illiilion of )iul])hurtc ether. 

'ITie ])rDc««t, 118 i-orn-cted by Pellclier, is as follows : Mix rifxtika. 
to^Wr in a retort equal quantities of concentrated acetic add 
ind tlooliol, and distil over tlie alcoliol. Pour it back into 
^r retort, and diHlil n second time. What cumeK ovi-r luiut 
bt (mired back a second time, and subjected to a third ditttilhw 
Don. 'I'he product of this third di^tilhition is a. mixture of 
Wtie acid and etlier. Siiturate the acid with potjuli, and dis- 
til »ril]i a moderate heat. Aectie ether comes over purt'.J 
Surliolz has given aiioUier process, which is much morv ecoi/o- 
loicaL Put into a retort 16 parts of acetate of lead, G parts of 
Hrang sulphuric acid, and parTA of idcohol. Distil over 10 
pirtk A^tate tliU liquid tvilh a lliird of its bulk of liine-wutur, 
itui decant-off the ether, whidi will swiin on the Hurlocc. It 
DMtally umounlH to H pnrtt.^ 

Schct-le eould not succeed in obtaining ether by Lauraguaiii' 
procesfl ; most likely bmnusv he ueglected to return the dintilled 
Uqoiil a suHieient number of timcii into the retort, llut be 
neovereil another, by wliich it may be obtained without dilli- 
culty. Nothing more is necessary tlian to add a little isulpliuric 
acid to tJie mixture; or acetic ether may be ubutined by dis- 
■olving one [mrl of acetutti of putjLsli in three parts uleobol, 
adding more sulphuric ac-td tlian is sufficient to satumtc the 
■h, and then distilliiig.jl 
Sdmlx, an apotliecar}' at Kiel, repealed the experiments of 
liccltf, and fouiut die'm accurate. His «x|ieriiuviits wcrv 

Sm Ounias and ilouDajr] Anu. de Chini, et Je l'b}'>. sxx«iL Vlj 30, 

t Jour, dt- Aa.\. 17^0, p. 3S4. I Jour, ilc I'liyH. xxiiiL t41. 

} Jour, lie L'hJm. iit. ti*. | ikliMlc, ii. 1 17. 



ckH>ui. repcatcdbyCTvlilenatiilLivbtcnborgwitlitbcsaincrMulL Tliejr 
affirm that pure accdc acid does not fonn «ther witli utcohol, 
but that etbor is foriDed if there be present the iniaUcst quan- 
tity of aiiy other aciil.* 'i'he subject has been lately examuwd' 
by HcnryT und liy 'rhciiard,} both of whom hiivc «l>owu iu tlie 
most BUtiitfiictory muiincr that acetic ucid iuid ftlcohol yivkl ui 
ether by the procMui of Laurnguats aiid IVUtitier. 

Tlieiiard employed nearly equal weights of n very strong 
■cid and alcohol of the specUic gravitj' 0'8036, and repeated 
the distillation 12 times. No gas of any kind was crolrcd 
duriufr the proceiis. He ilicii mixed the whole together, and 
«ndc«vourc'd to nciitr;Lli/f the acetic aci<i by potaslt. The neu- 
trallization Muccocded but imperfectly ; ubundance of cryttala of 
acetate of potash precipitated. Ry a cautious cLiittilhitioD lli« 
acetic ether came over iu tlie first place, mid uftcnvunln u ]>or> 
tion of alcohol, holding a little ether and acetic acid in »olution.l 
By a subsequent distillation off acetate of potash, the acctie 
ether was obtained perfectly pure. During the formation of 
tliia etber, a quantity of acid as well aa of alcohol dUappear: 
both of course euter uito the compoettiou of die etber, or at 
least their caiutituonta cuter. 

Dumas and BouUay, who examined this ctlier in 1 
formed it by distilling lA times a mixture of equal weight* 
concentrated acetic acid and alcohol, pouting back the liquid 
into th(! retort after each diMtiUution. The ether thus obtained 
was mixed with alcoliol, from which tliey freed it liy w^iuig 
it with water. No fewer than 15 waBhiiigs were required. 
These »o reduced the quantity of the ether that enough was nol 
left to enable tliem to determine its specific giavitj'. 
rnvndn- Acedc ether is limpid and colourlvts : it bus an agreeoblfl 

odour of ether and acetic acid. It does not redden vegetable 
blues. It hajt a peculiar lu»te different from that of all other 
BubHturices, und bearing no resemblance to tbat of alcohol. I(a M 
specific gravity, at the tem]>eraturc of 44"!, is 0-666, as deter- ■ 
mined by Tlienard ; and 0-882, at llic temperature of 64", at 
dett-nnined by Oelilen. Nu doubt weight in the case of this 
ether vi a teiit of purity ; we may therefore consider Gehlcn'i 
estimate us iienrcM the truth. Its boiling point, as determined 
by Dumiis and Buulluy, is 165°. TIic specific gravity of it« 
v»]>iiur is ;J-067. It bums with a yellowish- white flame, and 
acetic acid is developed during it« combustiou. It does not 

• Ann. dc Chim. Mt. IH. f Uiid. Ivuj. IM. ) Mem. iTAraieil,). 



undergo nny duui^ by keeping. At the u-mpemture of 62° 

it requlrc-s Piar« Uiaji wwti tinted ite weight of water to di»* 

•olve iL 

Tltou^ allowed to retnuin in eontuct with water, or dUiolvcd 

in it, DO cJmnge tuknt plnco, but wlien left ia contact with 
taiutic potash, acetic urid in ^duall)- evolved, which tatunilos 
the aikiili. If it lie disiilted ia tliis state, ulcohol comes over 
Terytnudidiluletlwitb water. NogaseotLcnuittcrisdiseugaged. 
It WW niuily/cd by Duinaa aiid Iloulluy iti the same wayaa 
ritrons aod oxalic vthent. They obtained the following oon- 
ttitueuls: 1 

Oxyi^en . 








lOO-OOO 1 00-00 loo-oo* 

Tlofte weif^ts are equivalent to the following atomic coiisti- 

7-74 atoroi carbon, 

4 atoms oxygen* 

7'4'i atoms hy<lro^n, 
Thete oome mAcieotly near 

6 utoui« carbooi 
4 ntoms oxygen, 

7 atoms hydrogen, 

ta Imvc do doubt that those atomn represent the true constitu- 
lion of the ctlier. 
But I have isliown formerly that acetic acid in a compound of 

3 atoms hydrogen, 

4 Atomfl carbon, 

3 atoms oxygciu 
cl these atoms from tlic numbers in the preceding 

En-ill ri-iuain 

5 atoms hydrogcii, 

4 atoitM eurhon, 
I alum uxygi^n. 

' Now, it ha« been already thowti that tlie^c are tJie consUtueiits 
\ of sulphuric ether, llius it appears that acetic ether, like tbv 
I two preceding, is a compound of mi integrant particle of acetic 
I acid and an intt-graul jmrlicle of sulphuric ether, liit atomic 
weight, therefore,')* IO-i^75. 

* Ana. lie Cliiin. <4 da Phyi- xxxriL ST. 


328 mvrnAi. coNPOUMDS. 

V chtp-iiL Let us see how well the specific gravity of iu i-npour wi 
~ CfliTifsjiond with this coiiHtittition. 'lliis was dclcrmined by 

t Dumas and noullay to be 3-067. 

1 volume )>ul[>huric ether 
1 volume acetic acid vapour 






2 16-0416 


If we coniuder it as a compound of 1 voliunc of sulphuric ether 
Olid 1 volumcof iicctic aciiivnpour unitod togoihor without any 
diminution of volume, ihe specific gravity will he 3l)1i08. Thi< 
conies witliin one per cent, of the dvterminntioti of l>uniafi and 
BouUay, and may tlierefore be eonsidcretl w •i^eeing' wilh it. 
There seems therefore no reasonable doubt that llie constitution 
of tliiii ether agrees with tliat of tlie tn'o last, namely, that it it 
a cotnpOHnd of I atom acetic acid with 1 atom of Mulphuric ether. 


9. Benzoic ElAtr. 

This ether was discovered by Scheelc." It was afterwErds 
slightly examined by Thenard,-|- and more particularly by 
Dumas and It«u]]iiy4 

The process of Seheele, as modified by Thcnard, ts the one 
which K luuully followed. It contusta in distilling a mixture 
of 4 [Hirff of alcohol, 2 [Kirtn «f benzoic acid, and I part of 
miiriiitic acid, till hulf the liquid hiti<i piime<l over. It is then 
poured hack, and the process repeated, 'litis distillation >i 
renewed two or three times. 71ie grentest jKirt of the ether 
exists in the liquid remaining in the retort. It is separated 
by means of n'ater, and two or three M-asKings deprive it of the 
greatest part of its exci:c» of acid. If we boil it on powdered 
litharge till the boiling point become fixed, and till all the 
excess of acid which it contains is MUtiinited, and afterwords 
distil it over with caution, we obtain it in u slate of purity. 

Thus prepared, it is a colourless oily-looking fluid. It his 
a weak »mell, somewhat like that of benzoic acid. Its taste is 
pungent; its dpccific gravity at 51° is 1-0539, and its boiling 
point is 408^ as determined by Dumas and Boullay. The ■ 
specific gravity of its vapour, acc'ordiiig to tlie same chemists, 
is 5-40D. It was subjected to analysis by (hem in the same 

* Opiiirula, ii. 1 M. f Mein. (TArcudl, 3. 8. 

t Anil. Uc Chim. tl lie Vky*. kxxvIL W. 

BENZOIC ETHF-Et. ^^^^ 329 

way as the threo preceding clhore. They obtained the follow- *"'-"^- 
iiig as it* constituenti : b»— — . 

hCaibou . . 73-82 a«p-twi. 

Oxygen . . . 19-10 
Hydrogen . . 7-87 

T\vw these weights of these elements represent the followring 
ttrats of each : 

90*46 atoms carboD, 
4 atoms oxygeit) 
13-2 atoniH liytirngeu. 
Bui tf we were to consider benzoie ether as a compound of 
1 9 atoms earbon, 
i atoms oxyffcn, 
I) atoms'bydrogen, 
llini the wei^it of eacli of these constituents in 100 parts of 
tbc ether would be 

Carbon . . . 72-62 
Oxygen . . . 20*88 
Hydrogen . . 7-00 

^>m, the deviiition of thcst' numbers from tliose found by 
"prriment, is not greater itian fn-qucnily occurs in such ex- 
[oniDcnts. The anal<^ of the three preceding ethers gives 
niBuch prubabiliiy to these numbers, that DumiH and Bnullay 
hit ailopted iheni as more accurate than their own. Let ua 
ft vhat the confttilulion of benzoic ether will be, admitting its 
■><«ic oonstituetits to l>e ns above statecL It lias been sbuwn 
"> I preceding part of th'w volume tliat benzoic acid is a cum- 

6 atoms hydrogeit^ 
Id atoms carbon, 
3 auuns oxygen. 
If ire itibtnct these atoms from the preceding table, there will 

»4 atoms carbon, 
& atoms hydrogen, 
1 atom oxygen. 
Bit tbese ar« the comtituents of sulphuric ether. It follows, 
Ibereforo, that lieiutoic ether, like the three preceding, is a 
cviD|>ound nf I iiilegniiit particle of benxoic ac-id, and 1 iute^ 
rant particle of sulphuric ether. Its atomic weight then is 



o^'" - Lot US floc how the specific gravity of its vapour accords with 
this view of its composition. It was found to be 5'409. Now i 



I volume sulphuric ether 

1 volume bcnsioic acid vupour 


9 1 10iN)27 


If we consider it as a compound of I volume of sulphuric ether 
vapour, and 1 volume of benzoic acid vapour, ututcd togr tber 
without diminution of volume, tlic »peoilic gravity n-ill be 
5'45i3. Now this dovs not dilTt-r w tuuch a-t one per cent 
fjrom the experimental result of Diuiuis and Houllay. Tbit 
ooincideucv seems to leave no doubt that the constitution 
benzoic ethur is really as above determined. 


10. Formic EtAer. 

This etlier was first formed by Arvtdson iu I777i but only 
in an impun- Ktntc. Hueholx* examined it anew in 1782, and 
t;elilcn-|- prepared it in a state of greater purity, and determined 
its properties, in 1812. ^| 

It was obtained by Oelilen by the foUowing prooraa : Equal 
weights of absolute alcohol and roi ice n (rated I'oniiic uci<l went 
distilW in a retort to dryness. The product wms disUlU-d a 
sceond time ; and tlie liquid in the recvivvr being mixed with 
a weak solution of jiotash, tlie formic ether separated, amouul- 
ing to about fuur-fifths of the alecdiol employe<l. ^1 

This ether is u colourless liquid, which has a strung unell of^ 
peach hcrncis, yet Gelden and Hose could find no tnipc of 
hydrocyanic acid in it. Oehlen com]>iires the tasU- ul!*> to tluit 
of peach kernels. Its specific gravity, as iictcrinined by Oeh- 
len, is 0-0137. It boils when heated to 133°. At the tem- 
perature of 73° Uie elasticity of its \'Bi)our is capable of sup- 
porting a column of mercur)' 8-74 inches in height acconliiij^ 
to the determination of l>obereiner.t It bunw with a bluiaih 
fUmc iticlining to yellowisli white. At the temperature oC^ 
65' it requires !) times its weight of water to dissolve it, U| 
dissolves readily in alcohol, and is separated again by tlic addi- 
tion of wat«r. 

According to Doiiereiner, it contains 44-2 per cent, of fotw 
mic ellier. Thouf^h this etlicr lia» not yet been subjected ta 

• Crdl*! Ncucntc! Eniilcck, vi. ii. f Schwdgget^ Jour. hr. 1^ 

I Oilbcrt'i Annulcn, Uxiv. 41(1. 




aMlyila, Uiere oui be litUv doubt, rrom tlie aimlof^y of Uic four *^ *'^-4 
preceding clhvrit, ihnt it in a rompouiid of 1 tnten^it purticle 
of formiu acid, and 1 ititcgnuit jwrticlft of sulpliuiic ether. 

n. Tartaric Elher. 

This ether was first prepared by Solieele ;* it wiu examined uiriair, 
uLh) by 'llii-nard, but lie did uot HUvcee<l in procuring it in n 
«Ut4.' of purity, t 

It uiu prepared by dislilling a mixture of 6 partt of tartaric 
acid, and 7 parts of absolute alcohol, and S paite of sulphuric 
aoid, until ether began to be fornied. The process was tlien 
ttopped : on eouling it n&iunieit tlie appearance of a thick 
■ynip from whidt water didjiul nejuirate any ether. It was then 
mixed with potawb : much biUirtruli^ of )H>tiL'<li fell and wa* 
•epantvd. Th« acid uns tlicn exacll)' saturated with potash, 
and the mixture digested in cuIdalcohuL The alcoholic liquid 
being evapnrutL-d, a litjuid wa* obtained, which Thenard oonsi- 
deriNi lui tartaric etiier. 

It bat a brown colour and a synipy co»si»tence, is slightly rmpntuih 
bitter and disagreeable. It luu no Hmclt, and conluius no 
cxoeM of acid. It does not precipitate tlie sotution of chloridu 
of calcium, but it precipitates chloride of buriuui. It dissotvca 
MMiily both in water and alcohol. 

12. Citric Ether. 
ThU ether wai al»o firtt made by licheele,^ and since his 

tirati luw beeii examined by Thenard} aloue. 

It may be prepared hy a process simihir to that wliieli sue- 
[ cecda witli oxalic etlier. Its colour b yellowish ; it is rather 
heavier liuui water, not very volatile, destitute of smell, uitd but 
a bitter taste. It is but little soluble in water, but disM>lves 
Nadily in alcohol. When digested with potaalt, citric ucid ig 
•epanted from it 

13. Malic Ether. 

Thfa etlter, m far as 1 know, has been examined only by 
Theiuird.|j The procaas is tbc Mine ait fur oxalic ether. It 
ha* a yellow colour, is somewhat heavier tlian water, is not 
volatile, and is destitute of smell. It is but little soluble in 
water, but wry soluble in alcohol, from which it may be tepar- 

* OpUKuIa, ii. 14». 
I Opuaculi, ii> 142. 
I Had. 

t Mem. d'Amica, ii. 13. 
$ Mcni. il'ArcunI, u. IX. 




Cbip. Ill ated by the addidon of n-ater. When digested wiUi pobub 

"^^^~~ malate of potJiitU U formed. 

'I'lieHC liL'st ihntt! etlien, cliougb tliey have not yet i)««u ana- 
lyzed it»r olitiiiiioil in a Atate of {lurity, preHenl an iiiaiiy aiuit^^ 
g;ivs with till* pn-ciNliiig, that their ooii.iiituciuii i« pruluibly tlic 
saine, namely, a combinatiou of uii iiitvgrunt particle of sul- 
pburic ether M'ltb an lategrant particle of die acid from wliicb 
each derives its name. 








TliiK substanoc wiw first olitniiied and descri?>ed by Che' 
in 1818.* 1 am induced to place It here on ueeoimt of il» 
analogy to alcohol and sulphuric ether in its coinpooitioa. It 
was obtained by t'hevreul from spermactti. 

The K|iermiiL!t-ti u-ait in the tir^t pluee freed from a yellow 
oil which it eonliuuN, by repented digestion!* and Hohitionti in 
alcohol. 'l'\iv j)nrified spermaceti (whicli Chevreul distin- 
guishes by the name uf tttint) was saponified by mixing UW 
]uirt«( uf it with 1 00 parts of potash dissolved in 200 piirts of 
water, and keeping tlie mixture in a tempcmlun- varyiag 
between 1'2!2° iind 194", agiLtting it frequently. When tb 
•aponifieation is complete u-ater is addt^d, and an exeew of 
tartaric or phosphoric acid, luui sulfioient heat is apjdied u> dit> 
solve the soap, and kept up till the fiitty portion collects at tbc 
surface of the liquid. 

Tlie fetty matter thus collected weighs lOI-ti ports. Ithu 
a light yellow colour, and be^n.s to congeal at I IS", but is not 
quite »olid till it be cooled to 1 10% and it does not become 
quite hunt till it reaches the temperature of IO*J°. Thi» fatty 
matter is a mixture of ettiat and tnargarie and oleic acids. These 
acidswere separated by heating it witli biiryle« >rater, stirring 
it ctHitinnalty till the acids were saturated M-ith barytcs. I'he 
excess uf Uirytes wa« tlioti removed by boiling dintilled water. 
'ITie matter being now dried was digesle<l iu cold but very j 
strong alcohol. The etlial wds dissolved togetlier witli a little fl 
m.-ii^iniie and oleate uf barylm. The alcohol being distilled 
olf, and the residue treated with idjsolute alcohol or sulphuric 
etiicr, u solution of pure cOtai was obtained. Ity the applica- 
tton of heat the solvent liquid was driven off, and lite Mhoi 
rcnuiini'd in a state of jturity. 

Ethal thus obtained is a solid colourless hudy, having the ■ 

semitnuisparency uf wax. It melts at about US", bm when ■ 

* Itcclicrchcs Cliiiiiitjuta sur Icb coqis ^xue*. pj>. llil, 233, 





put into water it doM not fuse titi i( has rcacbed tlie temp«n- 
bire of 172", Wlien cooled slowly it cryKtallizeii in brilliant 
piste*, and itom«tiines radiated ne«dles may be ob!ierve<l on ivt 
pirftee. Il has no uniellt and Hrarn^ly any laslc*. It miiy be 
Tolatilizfd at n If m|>orature tijnal to tluil which in rftiuisiic to 
Tohtilizf thf 6iity tMMlim wliich lu-o dostilulu »rund!ly. 

Alcohol of the specific gravity 0*81'i <li.'«wlvcti it in any pro- 
portion at the temperature of \2i¥*. But it is deposited portly 
h cryktuU when (he oolution cools. ThiH solution lias no action 
m rr^tnhle cotoum. When ethal is heated witli protoxide of 
Ind no water i* djsenga^d. It is inwluble in water : it does 
mA combine u'itli putisb. nor furni soup if it be pure, but if it 
h» mixed mtb a Hiniill quantity of inargaric or oleicacid, unites 
Hi^ly enough witli potash, and is converted into a soap. 
Wtler deprives thi« map of a gresit portion of it« potash, and 
rfp«n of its margaric aiid oleic acidti, yot the n'niduul matter, 
llmi|{{i eoDsiattng chiefly of vtlml, format it munlu^v with water. 
A compound of 60 parts of raargnrie and oleic acicU which 
Kxlu at 113°, and 40 parts of ctlial, become liquid at 1 1 1°. 

When etbal 'm heated sufficiently in an open vcwii^l it bums 
like wwc. Sulphuric acid has little action ou it, unless it be 
i«iMe<l by heal. In tlmt case sulphurous acitl is formed, hut 
mm of the etiuil remniiut undiitsvlvcd. Nitric acid has little 
•dicn on it cold, but when bent U applii'tl much deutoxide of 
note is ipven out, uiid the etJuil is piirtly dissolved. The 
■AmoIvciI portion I>ciiig treated \(-ith water, and the aqueous 
Hiation cfHicentrated, acid crj'stals are obtained. Alcohol di»- 
MivM from the niodue an oily matter. 

t^ul was snbji'ct<'<l to analysis by Chcvreul, by means of 
bJKfc oxide of copper. He found the coatUtucnts by weight 

Oxygen , . 6-2888 ca»t«uiui. 

Carbon . . 79-7S60 

Uydrogon . . 13-B45S 

weighu arc equivalent to the following atomic pro- 

1 atom oxygen, 
8-98 atoms carbon, 
1 7*7 atoms hydrogen ; 
ftunbcn which npproucli very near 



1 atom oxygen, 

9 atomH carl ion, 
16 atoim Iiydrof^n. 
Tlic ntoms of hydrojTfn nrv twice iw numeroat as those of cnr- 
boD. If wr wcn> to admit one more atom of hydrogen tlian 
Chcvrvul found (and the quantity of hydrogen in iilway* mcuit 
liable to error in the dt^tehniiintlon), tlion ethal might be con- 
sidered BB a compound of 

1 atom water 

C \ oxyK^n* 


9 atoms onrburetted hydrogen ^ ,^ ^y^^^„, 

Chevreul is of opinion that (lie carbon and hydrogen bear 
the mme ratio to each other in this BiihtiUtncc a« in alcohol and 
ether. This vas the reason of the name tlhaJ which ho gave 
it, and which is formed by joining the first syllables of the 
words ether and alcohol together. Diit it is obtious tliat tlib 
sappmed ratio does not hold, the atoms of hydrogen being tvlca 
as numerous m those of o;irbon. 



Tlie term nit is applied to a number of imctunns liqi 
which, wlion dropped upon pajier, i^ink into it, and miUte It 
seem fiemitniiiHpurcnt, or giro it wluit i.^ callci) a graag stain, 
[oi^whtt These I>oflies art- very numcroiw, and have been in common 
use from time immemorial. Chemwts Iwive divided Uiem into 
two classes; namely, vofatile and jf.iyy/ oils. We sJwiU con- 
aider the propcrtii"!' of the first of these classes in (his sectiotk 
TheySjfrf oils will occupy our attention in the ne.Tt. A third 
clasH of oils might l>e added which possess intenneiliiLlo pro- 
perties between the fixed and the volatile. 

Volatile oils, called uliw rxxeM/io/ ot&, are distinguished 
by the folhiwing propertii-s : 

1. I.i(|uid; ofU'n nlmoBt OS liquid us water ; somctimefl viscid 
or solid. 

2. Very comhwilSle. 

% An acrid tast«> and a Ktrong fragrunt odour. 
4. Volatilized with wuter at a temperature not higher tllH 


a. Soluble in alcohol and etber, and slightly in water. 
6. Evaporate witliout leaving any stain on [wper. 
By tlijs last test it is easy to discorer whether they have 





ndulteminl witli Any of the fisnl oils. Let a drop of tbc rola* 
till' oil &II upon A slipet of writing piiper, and then npply a 
gt'ntif licat to it. If it «raporale« without leaving any stain 
upon tho pnpcr, the ott iit pure ; hut if it leaves a stnin. It has 
heen contaminated with «wno fixoH oil or otiier. 

Volatile uihi aro almost nil obtained from vegetables, md 
they exist in every |>art of plants ; the root, the bark, tlie wood, 
the leaves, the flower, mid even the fruit, tliough they are never 
fuunil in the substance of the corylodoiis ; whereas tlie fixed 
nils, on the contrary, an almottt always contnlncd in these 

\N'ben the volatile oils are contitincd in great abtindanee in 
plantii, they are sometimes obtained by Htmplc expresnon. 
TU« is the case u-ith the oil of oranges, of lemons, and of 
bergamotle ; but in general they can only be obtained by dl»- 
dlbuioa. The part of the plant containing the oil is put into 
a «till with a quantity of water, which is distilled off by the 
application of a uio<lenitc hoaL The oil comes over along 
(li the water, and swims upon its sur&ice in the receiver. 
>y this process arc obtained the oil of peppermint, thyme, 
vender, and a great many otliera, which arc prepared and 
ploye^l by the perfumer. OiKer* are procured by the din- 
tation of rcninoun bodies. Ttiii* is the case, in particular, 
ith oil of turpentine, which is obtained by distilling a kind 
resinoiis juice, callei) turpentmc, tliat exudes from various 
ies of pine. 
TohktUe oils are exceedingly numerous. They have been 
g known : but as their u»e in ehemiMtr)' U but limited, they 
not hitlierlo been §ubjet'ted to an accurate cliemical inves- 
on. M. 'Ilieodore de Saussure, howe\'er, has made nume- 
rous experiments to determine the composiiiun of several of 
the moAt interesting volatile oils, They differ very much Irom 
Mcfa other in their properties; but it would serve no good 
puipo«c to enter upon a minute detail of each particular oil. 
I uall therefore satisfy myself witli an account of their general 
properties, and then give an aecoiuit of tiie characters of oil of 
turpentine, as a specimen of these oils. 

I, Thegreater number of volatile oilsare h'^viW, many indeed c«»mbi» 
■re as limpid as water, and have notliing of tliut nppeiLrance 
which we uitually consider as oi/g. lliis is the i-ase with the 
following ; luutvely, oil of turpentine, oranges, lemons, berga- 

• Fourcroy, viL SHi. 


nei:tral compoukds. 





raottP, ro«<'8. Othen have the oily viscidity. It viirics ini 
them in nil 'Ic^rooM. Tlii« h the cuse with tho oiU of mace, 
cardamom, sassatras, cloves, cimiamoii. Others have tJie pro- 
perty of becoming solid. This is the case witli the oiU of 
pguvley, fennel, aniseed, iialm. Others cryslalli/e by ^low 
eraporation. This it) liic case with oil of lhym«, iH'pprnnint, 
marjomm. The oil of nutmegs luu luuully the coa^isteDce of 
butter.* This is the case also with the oil of hopa sod of 

2. The cotoor of the volatile oils is as vanous as their ot 
properties. A great number are limpid and colourlest, ae oilf I 
of tuq)entine, lavender, rosemary, savine, aniseed. Some arf I 
yellow, an spike, bergamotte. Some are l>rowti, as tbymCfl 
savory, wormwood. Otliem blue, a.* caniomilo, mothcrw-orf 
Olliers green, M milfoil, peppor, \w\vi, parsley, wonnwood|J 
cajeput, juniper, iuig<e, valerian. Others, tliough at first colon 
lesS) become yellow or bromi by age, us cloves, cinnamon,] 

.*). Their odours are so TOrious as todefy all de«<njition. It 
is sufficient to itay, that all the friigrance of the vegetable Idng- 
dom reudes in the volatile oils. Their taste is always acrid, 
hot, and exceedingly nnpleiwant. 

4. Their specific gravity varies very considembly, not only 
in different oil«, but even iit tho same oil ii] difTerent cirvnin- 
stances. The following are ilie specific gravities of several of 
tho volatile oils, as ascertained by Dr. Lewis :| 

Oil of Sasaafraa . . 


Oil of Tansy . . . 




C'arraway seeds 


Cloves . . 




Fennel . , 


Spike . . . 


Dill . . 


Rosemary . . 


Pennyroyal . 


Jumper berries 


Cummin . . 


Lavender . . 


Mint . . 


Oranges , . 


Nutmegs . . 




The following tjiMe exhibits the specific gravity of several 
volatile oils, as determine<l by M. Ac Saussurc :% 

• Foiaaoj, viL SOS. Bng. Tnat. -f Nenmaii't Oieixi. p. WJ. 

t 1W*I- J By my iteteniiiiiiuion. 

I Soroetiawa oil of tiirpcnttne in iw high m 0-8Q- 
1 Ami. do Chim. et de Phj-ii. xiii. VM. 


^F TOtATILE OILS. ^^^^^^T oBB| 

Coramtin oil ofntiiM " . . 0-9857 at 78» ^t-^ vt. 

< Solid oil of aiibc . . 0-9849 at 78 

f OJ! of kvi^iidcr , . 0-896 iit 68 

I Oil <.f rosoroary . . 0*8886 at 60 ^m 

k Oil of tuTpratine . 0*86 at 71'Jt ^| 

I Oil of lemons 0*647 at 71*5 ^M 

} (Klofrwos 0-Bd*i ut 60 ^M 

I Wtifti (III? volnlilc oiU are hciitcd in tlic open air, they eva- ^H 

poTBte rettdily, and without alteration, difTu-siiig tticir poi-uiiar ^H 

idoura all around; but therein a oon*td4'nil>ltr(Itfr«Tcncrbctwwii ^H 

Ap diSen>nt oilx in tliis reN{M>ct. Wlioii di.<li)li'd in close vo»- ^H 

•eb, they do aot so readily usMime the form of vapour. Ilrnce ^H 

thry low thpir odour, become darker in colour, and are partly ^H 

deconposed. Oils dn not seem verj* susceptible of assuming ^^t 

Out gateoni form, unless some otlier substance, as water, be ^^ 

THe following table exliibitfi the eliufticity of the vapour of ,'uJI!f','?lIlI, 
nriou mis, at llic temperature of 59°, a^ determined hy M. 
At Saiissure.* 'I'he ebiMidty is uinMured by the height of th« 

cohuBu of mercury whivh the vapour w cnpoblc of supporting. ^^ 

Vapour of u-nter 0-&07 iudies mercury ^| 

Oilof tuqK*ntine 0-354 ^| 

lemons 0-364 ^H 

roaenary 0*349 ^M 

lavender 0-310 V 

roM* . . . 0-0787 

uite, ootsmon . . 0-059 

aiuse, solid . . . 0-a-}94 
Oil of turpentine begins to boil in glass vessels at 314°. 
Ai tJie teiifuon of oil of lemons is the Mine as that of oil of 
tVprnline at 59°, tlie IxHlinpf point of both w proluibly the 
sue. I'he other oils probably will not boil till tliey are luiM'^d 
tsa conaiderubly higher tempcrutnrc. 

When exposed to the action of cold, they congeal like tlic^^'™'' 
filed oils ; but tlu> temperature necessary to produce tliis elTect 
Tuies according; to the oiL Some of them, us oil of anise and 
cf feoDcl, become oulid at the temperature of 50° : frozen oil 
<f bergamotte and of ctuiella b<-come liquid at 2!]° ; oil of tiir- 
peotine at I4°.t Mat^ucron exposed several volatile oils tu 
a coM of — 17°. They congealed or rather crystatlixed |>ar- 

* Aan. ds Cfaln. et Jc Pbys. xiii. 2A9. 
f Margueron, Jour. At I'li)-i. xlv. I^rt. 
II. z 




c>*P' '"■ liiilly, and nt lUo ttme time cmittotl nn cUstic fluid. These ' 
cryHtals coii!iist«d partly of the oils tlicmselvcs, jwirtly of ollwr 
8tili«tftpce.'«. Some of tiiein laui tlie properties of benzoic hci*!." 

5. VolHtile oils, wlieii iixpo^od to rlie action of light in elo»>e 
vcs«eli, and exdwled from eoinnion air, iindciyo very Riitf^kr 
cliitnfres. Their colour kccometi deeper, tJiey ac<)tiiro i ijTeat 
deal of consistency-, and their specific gravity Is considerably 
increased. The cause of tliese eluuiges is but impcrfecily 
known. Tingry, t<> whom wn »re indebted for thme tnterosl' _ 
ing rp»cnrc-hes, bus proved tliat light is n iieee«rary a^nt Ilv 
was supposed formerly tliat they were oecnsioned by the »l»orp- ' 
don of oxygen ; and when oxygen in predent, it has been nscrr- 
tiiined that it tti ahwirbed : but Tingry has proved that the 
tame clunges go on when oxygen is excluded. Thi* philiMn- 
pher aaeribes them to the fixation of light. If tliis be the real 
cniiw, the quantity of light fix(*d must be eiiAnnons ; for wi tbe 
Rppcilic gravity uf llie oils is increased eonsidemWy wliiti- the 
bulk contiiiuei* the »Mne, it is evident th&t the atwolute weight 
must he increased proportionably. One eireumstanee, hoWerpr, 
render* this eonelusion somewhat douhtfut, at least in ib full 
extent; and that is, that the (luaiiltCy of change was alu-aya 
proportional ut the (juAntity of the oil tind llie quantity of tit 
cout«inc<l In (he vc*sel.-t 

II. It is probable tlial tJie volatile oiU absorb and combine . 
with the fHfTerent sopportem of combuM.ion, ihongli no correetflj 
set of experiments has been hitherto mnde on the subject- ^ 

1. When volatile oik are exposed to the open air, they gra- 
dimlly become deeper coloured, and acquire mor^ and more 
viscidity, while at the same time their odour diminishes. Dr. 
Priestley first ascertained tlmt tlicy imMbe oxjf^n with rapHfity, 
and that tlie changes luv owing to their nWrjition of it He 
tried the experiment only with oil of turpentine, but he found i: 
that t)ie air above oib of mint and cinnamon, confined in phbbfl 
half full, was deprived of it* oxygen. | He ascertained Itkfr-" 
wise, that, independent of this disposition to nlmwrb oxygen, 
oil of turpentine has the property of imbibing u canxidenible 
quantity of air, which may be afterwards extricated by means 
of l)ie uir-])um]i.§ Acconling to I'oiircroy, thiti ahsnrptfon of 
oxygen is accompanied by the formation of water. His ert* 

• Margueroo, Jour. Je Plijni. xl*. 130. 

t Tingry, Jour, ^e l^bj*. xlvi. 1 6 1 and 2*6. 

^ Priewlejr on Air, a. i32. 





■M for (lib h, that drop* of n-ater, h« says, are often per- *«»-vl 1 
pCtUa at Um $UTfac^ of tho»c oils tlutt arc kept in vesselii not 
nperly cloaod.* By loDg etjMMuro ttic voliitilc oitii nMitmc 
B form of resiM. 

When die rolntilcoil«iirpli««tl«l8uffirk'iitly iii thcojwnair, 
vf take firo nnd tiiim wtlli n clear tn-ight Rame, emitting a 
rt qMDlity oi Bmoke, Tlie ]iro(iuclii nf tti^ conibusdon, 
iUM tlia wmtt ara wBter anil carlmnic »cm(. ■ 

ft. Oil of taqienttiie at k-ast iilKiortts ftn<l winltiiH-s wth chio* ofrf'i'uwr, ■ 
■e, anil tb« properties of Uia new compound ure very difler- 
t fnmi tliiMr uf oil of (iirpeiiliiie. Mr. Porrctl caused the 
puur vi 4jil uf turpentine and cbloriiie gas to poM togetlier 
n>U||(li n gbtM tuba int« a receiver. There was formed a very 
Hit heavy white oil, wUicli iwiik immedialely in water, and 
U^ HiDelt and la«t«d very mueh like nutmeg but coin- 
Bunirated ratLer a mon.* vauMtic sensnliOD to the totigue.f A 
coinpoiitiit M-«-in6 to liave been otit^ined l>y Dr. John 
Dcry by mixing; jHTcliIoriilo oi' tin willi oil of tnrpi^ntine.): 
S. Tbc action of iodine on volatile <nU Ium not b«eii tried. 
lU. Tbe action of the fdinplocoinbiislibles upon the volatile 
oik u not T«iiuikal)!e. 'I'lti y do not »bsoH> hydrogen w* far 
ai la known, neither arc titey altered by eharconl. Wht-n 
ilignted tipon snlptiur ut tlie temperature at which the Mulphiir <it<uii>'">r. 
MlMt tlicy dtnolve a portion of it, acquire a brown colour, 
vt)L a dka^reeable taste and sniclL I'liese preparations are 
oiled baUam* of Aulphnr. A portion of the siilplutr erystnl- 
liuvM thoy coot.} When tlie«e halsumsare heated strongly, 
■ nat quantity of giw, (probably sulphiiielled liydrot^i-n ) a 
nulved ao nipiilly as to occasion very violent explosions, unless 
lifupcr precautions be taken. n 

Tb« vobuile oiU dissolve Likcwis4^.t )>orlioii of phoa)>h<n-us in ^'""i'"- 
> dipeMitifr heat ; but hkmI of tlu-nt deptwite ilur whole of it 
>^aill as the lolution cools.. HotTmun pointed out a method of 
ttadcring tho solution permanent. It wa« lb« following : Tri- 
tutata togellier 10 parts of camphor and 1 of phoapliorus. Thui 
a imu e diaaolvesreadily in most volatile oils, OS in oil of cloves 
ui firms a solution which Itas the property of rendering every 

* Fourcitty, vii p. £01- En^ Trnna. 

t NidMboa** Jounwl, ixiiti. I(U. lUcL p. IT. 

$ 'ttf—"" Ae OijniW of Dijoii Acaileiiiy, in. 357. 

I lloflfaian relate* d reniarkable Ktciry o( tlie violent etktu oT luch on 
njilonon by way of tautlon to the clieiiiiKU or lii* tims. OlMtrvntionca 
lit)*- Cbm. p. 306. 

"t*"- _ 


o^'"- iLiiiK 

Aet\ni\ of 



liaouH which is rubbed witli it, luii) llii> witltout com 
bustion.* 'Dib wcins to h»ve beou Ui« solulion twinuch um>J 
by Boyli'i uiidcr the iiauie of liquid phonphi/rut. 

W. 'Hie alluJ!?§ and eorllts act buc feebly ujwii (be rotatite 
oils. The French chcmiif&i buvo {iraposed (o ffivt- tlie vwmbi- 
nations which these bodies form with the volatile oils iIm! ituRie 
of sat'OHHtef, wliicli Dr. Peorxon hits translated by the Xtna 
sap^iHuks; but tlicse ttenonuiiations have itvt been wlopted by 

. M'boerer conaidera the t«dK>ii» trituration of potash uud oil 
of turpentine Ioj^i'Uiit, by whidi the iiu'diciruil prcpckratioo 
ciiUod Sliirliry'* stia/i is prepured, and compitrcii it with tlfo SuA' 
lily witli whicli tliutiilludi<tiii9olr«0conimon turpentine, will hf 
indiiit'd to believe that the eombinaiioii laJu-» pUct* uDly in ^^o 
fur m the oil is converted into a reiiin : aiid that itis not (Ik* oil 
whicli luis the property of uiiitiug with potafth, but tfaa min 
formed by its ab§orbin^ oxygen from llio atTnosphcre. Inderd 
it is not iin|iriil>alik>, Uuit the volatile oils ulniorb and purt with 
oxyt^n, with tnueh greater facility thaii ha« been hitherto sup- 
posed ; and that during many of their RolutionB these changt* 
take place. Volatile oil.t neem to unite to alkalies and eartk 
only whoii uniliil to OXy|>;i'n mo IM to form ri'Miif ; while rewns 
on the otlicr bund, may probably owe their solubility in idco- 
hoi to their partin|{ witli oxygen, and assuminj^ tbe state at 
volatile oU§. Some experimcnLt uf Mr. Hatehett at Iea.<<t rea- 
der the last iiuppo§itioii not improbable. I s}iall nientiuu ooe: 
J-Ic took about half a pound of the cummoti yellow resin of the 
jihops, and having; diHHulved it in mther Ivm tbiui u (juart of 
alcohol, he poure<i thv clear sohitiuii from the dregn and impa- 
rities into a glass basin containing about two quarla of distilled 
water. He placed this baMii on a rand-bnih, and heated it 
moderately for about four boura. The principal part of the 
resin wais preeiiiitsited ilurJng tlii-* digi^^lion. Next itay the 
milky liquor was |H>UTed off the predpilHte, atid evaporated to 
dryness in an open veaeeL During the evaporation, brittle 
films of porft'ct lesin were formed suoceosiToly on the suiJace 
of tite liquor, end the dry residue, aAcr evaporation, u-as IJko* 
ivi«e complete rcHin ; but the portion which hiid prt'cipitated in 
the first Wsin, and which constituted the chief part of the oii- 
^ital. was not in the Mate of reNin, but of common turpentine, 

• Holfinan, Obwrv. l*hy». Chem. p, 307. 

+ The (erm lapmmlr doM not ngrce »tll willi the idiam of our Iimpngn 
The word tvbtoop, or soincitiiiig »iiiiilar, would have been better. 





mc phenomena Enilicate in a very unequivocal maoner, that **''■ 
yiOTi' liad been taken from the re«n during its solution in 
icohul. Hence ibe jiortiuri whicli |ir<>ditil»U*H immediately 
hva th» Halation u-im poiireii into Witter, n»t Win^ in contact 
ich the air, fell down in tfac state of turpentine ; while tlie por- 
D that continued in contact with air bcoune perfect rosin. 

V. AVhon nictated witli water, (be greater number of the 
hxUt oils render it milky, an<l coromuniottc to it their pecii- 

odour. Several of them when droppe<t upon stii^r, if ibc 

be afterwards dimiolved in n-alcr, farm n permanent ttulti- 

to which tile name of o/to-sncc/ianim has been given. 

neroii ha.% shown that lliiti property belongs only to the 

est and most limpid part of the uiEs. 

They are all Noluble in alcohol, ether, and fixed oils ; (hough 
Aejr VETj- considerably in the facility with which Uiey unite to 
alcoheL Oil of turpentine, Ibr instanceT 'i known to unite 
wly with that liquid. M'lien 1 part of that oil is dissolved 
7 parts of alcolwl, the oil M^pur.ittw by degrees, and wiikii to 
■ bottom,* 

VI, 'i'lif action of the acids upon the vt^dlo oils hat bucn 
imperfectly examined. 

Snlpliuric acid acta upon tliem with considerable energy : "."'i*""* 
fiaolviii<r them, converting them at fxmt to a substance of a 
.1* luiture, and ut hust reducing them to the itate of eliar- 
noJ. Flence we may procure the oil in very different st-ites, 
by M^mting it from the acid al the end of a lunger or tdiorter 
inl»TVJil by pouring the mixture into water. When a volatile 
nl ia dropped very slowly iim) four times its weight of siiljiburic 
tdA, triturating constantly after every addition, u solution is 
Innned ufii hron-ntsb colour. If tlits solution ia poured into 3 or 
4 jwrta of water, ami then genlly hejitwl, a brown mass sepa- 
lates, which wan formerly known by the name uf an acidsoap. 
Achant ia the only chemist who has examined tltese comhina- 
liOM with attention. His experimontx were made chiefly on 
til of tur^ientine. The mass which separates when thi« oil and 
Milpbnrie acid arc treateil a.i above described, is of the consist- 
uoa of Moft wax, Miliible in water and alcohol ; and n-hen 
d«campOMtd by an alkali, the oily matter which separaU's unites 
mtdiJy with nlkalie«.|- Hence it appears tliatithasapproachcd 
the >lata of a roiiu 



■ Nnistm't Chan. p. 88a 

f Jour, de Phfi. xn. 409. 


Aitiou to 


Mumtic acid has tnucb less action ou tliem ttian tl>c Kulptiuric. 
From AcUard's trials it dissolved -[jijUi of its weight of Uia oil 
of sassiLiras. The jwrtioii <lim(ilv<rd is [irubaUy altered.* W'it^ j 
mtiriutio iici<I oil of tur]>ciittiic combines luid fonnHUcompouid I 
Teiy similur in its u()prjiTance to camphor, 

'\\'heii niU'ic acid is tlirowu upon tliom Buddrnly, luid In 
coiicciitxated state, it act>> witli sudi energy as to »et tbem on I 
fire ; but whi-ti niijlicieiuly dihited witli water it diwMilven litem, I 
luid eotivcru iLcin into a j'cUow Hubstuiicv aimilar to rf.iuivJ 
Chtorioc acts iii the some way, though with lcs» energy. 

VII. The action of the volatile oils on metals has nut been 
examined with care, but it cannot be reinarkablc. Margucruft 
likH tried the efiect of some of tlie tnlu uf mercury upon wrcnd 
volatile oils. The followiiij; arv tliv fuct« nsoertaiiied bytkii 
dicmist : W'licn oil of rueemory is ke]>t over nitrate of inermry, 
tlic salt is );nidtially decomposed, and tlie oil acquires a <teep 
colour. Conxwivv ^ubliniale, in lilie mnnner, dcepentt 0*e 
i:olour and increases the con>iBtenee of viU of citron, chemi, 
hyssop, lavender, roseiniiry, and peppermint; while iti>>»tthc 
same time partly converted into c^onieh Neither the murulc 
of mercury, nor thesulphnretof tliat metal, produce any chaiiga 
in tlie oils of lavender and rosemary : but hy tliis last oil the 
red oxide of uieretiry ix converted into the blnek, though tiie 
oil does not cx[>criencc any sensible chaiigv. The dtloridc of 
antimony i« ItkcuUe decomposed by tlit oil of rosemary.-]- 

M. dc 8imssure attempted the analysis of several of the vola- 
tile oiL^ by burning them in oxyf^en gas, and ascertaining tlie 
quantity of oxygen consumed, and the volume of nHionic add 
fornied. 'I'here arc scverfll ciicumsianceB which make it diS- 
cuU to obtiiin very accurate results. The oils are so rolatile 
that a pordon b apt to escape combustion, and nuitgl« with 
the gasemLs product* under tlie form of vapour. But the gnu 
ubsUiek- to correct results, is tlie impo*nil)ility of freeing th 
oils from all foreign matter, and brijiging iliem into n 6lal« < 
piuity. Till some method of effecting this be devised^ tin 
mialysis of the volatile oils cannot lead to any liatii^raiTtory roii< 
elusions. The t'oUowiug tabic e.vhibitij the eoitjitiiuenlii < 
(lifli'rcut oils analyzed by ISaassure :{ 

* Elciiieni dc Cbymic of the Dijon Acadtntf, HL 361. 
"t Ann. dc Cliim. xlvit. BS. 
t Ibid. 





AIM*. TOUl, 

Oil of lenwns 



0-776 loo 




0-566 100 

' laveiuler 




o-m 100 





0-64 100 





0-S74 100 

antxe, couiuiun 





tlilhJi ^Ud 

"Ml t«3-;*lia, tt-54l 



IWac weljjIiU gtvo tu die fuUoH-iHg Atomic coiutitueiits of 



Oil of lemons 





UDiw, CO mm im 

ditto, solid 














lieu Atonic w^i^lita oiay be couvemsl iiilo volumes, uinpty 

mvidiii^ till,- utiMii.) uf uxy^cii l>y 2, uitd idlowiiif; ihv utiicnt 

'to rvinain unulu-red. If wo kiiew the vpccilk- ^mvity uf tlie 

mU ill a sLite oi' vapour, these vuluinet would «»al>le us to form 

mkhc idoa rf!t{>e<;ttug die c-oii.'^tiitiou uf tin.' iiiu-Kraiic )>iini(.'lu 

vf «wcl) uil ; but our ij^iiuiuiici- of tJiat uMeDtiul vk-me»t prc- 

.vvnt* lUiy utlier «Hiclu<.ion tluin wliat regards the ratio of the 

I aionw of tile hydrii^i-ii fnid carbon. 

In oiU of lemoDS, tgrpcntiue, taveiuler, and roses, ilie volumca 
i(tf hjfJrvgeiiiiad carbon approach eijuality. It UprolKdile fruin 
/this that in them tlie liydrogeii ajid carl>oti are coinbiiiecl so as 
te some modifiuilion uf «iibu!iyi)r<>f;(.'n; but Uaw inauy 
k of each go tu thv fornuilion of lui iiitugruHt jHu'liclc il U 
[ iin|HMbibla to auy, probably a niiicli greater nutobcr (liao any of 
I carbokydrogt;!! lutlii-rto ejciiniiiied. the highL-»t of whicb in liexa- 
) (nrbojtydrogeii, or u cunipDuiid of G atoms ctirbon aud G atutns 
hydrogen into one volume. 

Solid oil uf aniw! seems to consist ofa compound of 1 volume 
of hydrogen and 2 volumes carbon vapour, or some multiple of 
that. It ia therefore analogous to one of the oiU from oil gas 
which Witt subjected tu analysis by Mr. Furadiiy. 

Oil of rosemary and common antse appear to be a compound 



c**» UL of 1 volume h)'ilro|^cti and It volume carbon vapour, or sonii.- 
multiple u£ that. It U tli«r«t'ore luiiilotxitmi to naphtlialme. 

The ox^ygen enlera into Uicmi bodim in very «imill qiuindiy. In 
luvetulvr und roM oils it a probably united to carbon, but in oiU 
of rownuiry and Dontmon imiDe, and in solid aiitse oi), it §eein9 
to he uutli.-<l Ui hydrogen and lo oonsdlule wai«r. The preaenw 
of aato<e uin ioierred by filauMure £roin the a|>p«arancc of a little 
nmmouiit during \m aiwlyws of tliv dilfKrcnt ojlit. lu qtianllty 
iit Ml small, [lull if it i-ntf nt ii.s an utooiic coni[iound, die numbi-r 
of atoms of the otbvr cotntitu«nt« m»»l be prodi^iMw. Thu% 
if oil of lemoiM onntaia au atom of Kioto, it must be a oompound 
224 aloins hydnifreti, 
2fiii atoms utrbon, 
I iilom axot«. 
Of tlie nature of so vrry complex an iiitr^7«nt parliclfl m thia 
it i» dilficult to form any conception. 1 think it qutti* conceiv- 
able tlutt tiii^ ammonia may have originated from the presence 
of a little iu!oti« ga-1 in the oxyfrou )pM employed iii tlie com- 
bustiuii of lilt' dill. At any rule, il.f quantity m so Mnall, that 
ill the present »Uite of our kDowled|ro it may be ni-glrcttnl. 

Oil of lemons and oil of turpentine appear to cooluii no 
oxygen, but tliat principle enlera as a coiititiluent into all tfa« 
othvr voLitilo oihi subjected to aualy«ia. 

A'olatile oils ar« applied to n great numl>cr of ineti ; Somi- of 
them arc omployi-d in medicine: some of thom, at oil of tur- 
pontine, are much u§ed to disiwlve resins, which are nfterwnrdi 
employed as rarnisliefi. Not to mention their employmrat iiti 
painting and in perfumery, 

on (ftoTTw. Oil of turpentine, on whicli I tJall miike a few observationa, 
m» cuiulilnling one of the mi»t im[H;rliii>t of the volatile oils, is 
obtained by the di«tilhiliou of various kinds of turjwntitie. V^liaC 
remains after the distillation is common nm'tt, which h employed 
in considerable ((uaiitily iii the maiiufaclurc of yr/tow sttap. 

Oil of turpviitine hi IrujiKpureiit iinil niU>nrl<-'M> like water, i 
hit a strong and peculiuT smell awl n hot acrid la«u>. It begins tO\ 
boil usually ii)>ont OM'', but as tlie boiling goes on tlic boilia|f' 
point rise« ut least as high as SaO". It is obvious &om &k 
that common oil of turpentine coustiluteti a mixture of variou 
oilsf differing from each other in tlieir voUitility. When pasacd 
through a red-hot purceluin tube it ii decomposed, a great 
i)uantity of lamp black is deponited, and carburetted hydrogen 
gH», mixed with a little caibouic oxide, issues from the extremity 
of the tube. 






r AdoenUag to Sairasure, jt ahwrbs In 4 moiitli* 20 ttmc4 its f^y^ 

I roJiune of oxygen ga*, niid ii qiiai>(!ly of rarbonic acid gas 

I M|uai to 16 titaM iu volume may tben be driven out. By , 

lexfMMure tothc itir it becomes bron-n and tbick. It tben is J 

Ibund to contain a good deal of re&ui, wlnrb may bo tti'|t»nitcd ^H 

1^ diauUJiijf off tite oil. If wu bttal it witli peroxide of Icud, ^| 

f npours of water are exbadvd, tJic oil bcvomes brown and thick) ^H 

■■I^Bt Ui6l (Mii!ililuti=t mvrttly n compound of oxide of lead and ^H 

^^^o( a ^eyiiJi wbiu- colour. ^^ 

V Oil of iur|>e[ilLnu docs not dittitdve well in alcobol unleiui it ;*i^",'" 

^ b* froc irom water. 100 parts of alcohol of 0-H4 sip. ffravity, j 

diatolvc IJJJ parlfi of oil of turpentine at 62". If wc a^tate J 

impure oil of turpentine with ^th of iu wvififbt of alcohol of ^H 

fMSHtp, gr. the spirit diMolvcs the roMiiouK portion and may be ^H 

iftonranb separated. By repeating this process three times wo ^| 

dtfirire the oil of all ltd rc-^in^ but it retains a [tortlon of llie ^| 

llwhol, wbidi maj' be separated by tvater. By dissolving u ^^| 

Bale oil of turjMiDtiiitt in ulcohol we give the spirit the property ^H 

tf buminff with npk'ndoiir. ^H 

h xbtwrbs n great deal of muriatic acid gsa, and formH by -^^| 

teiahiutn^ witli it the arti/lciaJ camphor discovered by KIikL ^^| 

llJBMtod oil pretty strongly by sulphuric acid; and iii trie acidj ^H 

npecially, if it be mixed with a iguaiiuty of sulphuric act<l, scti ^H 

it m fire. It alu-ayit Tcddvnt litiniis paper, and tliercforv com« ^H 

vim a liltio add. Front tbv ubtMTVutionB of Lccoiiu and Ser- ^H 

ht thi» ncid appears to be the svccinic, ^ 

ll diioolres by digestion ubout liatf its weight of sulphur) uiiibut, 
fonniiiga red coluurvd)toluiiijii. It UagoodMlveittof iodine, 

■ml in cnpabW al»« of dissolvittg u little phosphorus. It is an J 

FXeellenC iwlvent of resins, and constitutes in consequence tho ^H 

DcdJnm by which various varniiJie» are ol>tained. ^H 
It nbtorlw 7J times tl» volume of wnmoniucul giLt, 5 time« uouxobai 

Its volume of cyanogen gus. Sulphiirous acid gn« and fluo^ilicic . 

Bcid gaa are ubo Bl>»ori>ed by it in coRsidornMe quantity. As ^j 

B ine«licine, oil of turjientine possewws considerable value. Its ^H 

action de{>en(U upon Uie done. When given in doses of 1 or ^H 

! dracbniH it neto on tlic urinary orgontt M> powerfully lu »omo- ^H 

tiBMs to oceobion bloody urine. When given inouncedoscalt ^H 

sttuiulates ilie Iwwcls, and scarcely produces any effect upon ^H 

the urinary secretions. Iu obstinate cases of costiveness it acts ^H 

with wore ccrtjtinly lliaii any other medicine. I-'ur the tenia ^| 

it is almost a spcrilie, rUscharging it in all cases dead. As an ^H 

cxtcriwl application in rheiimaUsm it i» a medicine not to be ^H 



ch^>N. (|<>s|)iM.-d. TIic 4juack iitMlicino caUrd eaaancd of mustard i 
rnvruly a soluLiori of camphor in oil of tuq>cntti)e. 

SfiCTIUN Vll.-T-Or FIXED 01I.S. 

Tlw fixetl oil-*, wLich iirc of suci cxlcusivo utiUty iftii 
arts, wcrv* kiiuwit itt n vi-ry ivmotc period. 'I'liev me moiitM 
iu <ieiH.-Hs uid duriug tbe tima of Abraliam were even naed 
ill liun|)6,* The olive wus xery early cultivated, and oil ex- 
tnii'tod from it, in £gy|it ('ecropw broujrlit it from ^-liis n 
town in Luu^r J'^ypt? where it Iiad bovii imltivutvd from time 
imm^mociid, und t»u|;i4t tlie Atlioiiiutn to uxtmct oil from JL 
lit tliis manner (lio use ol' oil bovaino known i» Curofw.f But 
the Greeks uecm to hare been ignonuit uf liio method of |>r»- 
'Ounu); I'^ht by dk><uu of lamps till uttvr tlic isivf^e of 'J'ruy ; at 
kttt Homer nwvr mentions them, and constantly describes his 
heroes us lighted by torches of wood. 

I'txun OILS iin: distiiigtiiahed by the following characters: 
I LXi<]uid, or easily bccocne ao wheji exposed to a gimlli; he«t< 

5. Au uiietuoiu foel. 

3. Very combiisttblv. 

4. A miM taste. 

6. Boiling point not uitder 600°. 

6. Insoltiblo in water and ni-urly im> iit alouhoL 

7. Leave a grea&y statn upon paper, .i i |i.. mi, 
These oils wbieb are alaocalled crpre*»etf<MiB, are luunoruut'l 

and are obuuiied parttj' from animals and (lartiy Irom vegetablesi | 
by simple expie»ioii. A» iiuuuicivi lutiybu mentioned whale 
oil or train oil, obtained from lite blubber of the whalv iuid fnm 
cod ; olive oil, obtained from the fruit of the olive ; Unseed oil 
uid almond oil, obtained from iinst^ed and aluiond kenielifc 
Fixed oil.^ amy also be exlnieted from poppy -!>eeda, lierap*KvilS| 
beech-mast, uad many other vc^ctublc »ub»taiioe». 

It deservct attention, tliat the only part of \-ege(able« in I 
whieh fixed oils arc futntd i» tliu siH'da of bicotyledonous plants.} i 
In animals they arc must usually deposited in tite liver, though , 
they are found also in the eg^ of fowhi. 

All tliesc oils differ from each tttlier in Mrverul [MU'ticuLirs 
but they also poasosa many partinilare in commou. 

1. Kixcd oil in uHually a Itqnicl with a oertain degree of vis- \ 
ffldity, adhering to the siiU-K of tltc k''^'^ vcmcIs in which it is 
otHitained, and forming slreuks. It is never perfectly transpa- 

*, IT. f Ui.TMlot.Ub. ii. M and 02. | Foutcro}-, vii. 310. 






tvtit, InvEiifr ttlwayn a crrmin do^rre^ of ouJour; most nsually 
[l i« ycUowiiU) or prreiiiitifa. Iti Uisto is street, or mmrly \aa- 
fii. Wlivn iivKh it liiH lilUc or no smell. 

TliiTe esisi hIho in thu voKchible kingdom a considerable 

bcr of boding wiiidi, u tlie ordinary leinperature of tlie 

'MaMwptH'ra nrc «ulid, and itxre hitlierio b^rn ooiutdered as 

Hxi^ <ril«. I'ltttn oil inny be nieiitiMKrd lU un example, wliicli 

IsB Imm-11 sobjctinl to n cliemical exnniinatioii I>y Dr. Bu«tock.* 

I'bo vorioiis flub«Unci-» itM-d lit India aad Africa m sulMtitutm 

for butter, and as uiig^ueiits, may likowiee be mentioned. Most 

flf them are obtauned from the &eeds of uvi's ; <liiri^r<.>nt species 

cf ibe bOMlia, as the but^aeea, haiftJUia, talifhlia, oAtMia/O, 

yield lilts butyraceona uatler. 'i'bey bavu ln'on <lo<!cribMl by 

Dr. Roxburgiut 'Hie tihv* or butter tn-e of Africa, described 

li; Park, seems also to bu a sptrcies of bassia. These huI>- 

ManecK, from tlie experiments of I>r. Butilock, a|ipc«ir to differ 

■ Ultte from tlio liquid ftxed oils in tlioir propertioi, and to ap- 

ptMch file iiuture of uiu. 'i'bus tliey ure seiisilily soluble in 

i^hol and ctber, aiid do not combine m> readily with alkalies 

Bt tlie fixed oiLi. 

'2. All ibe fixed oils liitlierto exnmiiiMl are li^btor than 
walur: but they dilTrt irreatly from «iio uiiotlier in spei-ific 
gisrity. Tbe sanie dilferfiice u oW-r\'able in ditVi'rent snuiples 
of tlie same «iL Tbe foUotriug (able contains tbe specific gra- 
vity of such oit« as have been examined : 


iIOe gl^ I 

OEI of i»lml 

Haxel-iiutaf . 



Almiitiils]. . 


Bci-clt-nutl . 

Hen I . 


Itape-seed|| . 


Neut'ii^oot oil' 
S. VixtA oil tluM not begiu to 
iLore tlie boiliu); jwiiit of water. As tlie lieat increases, a 
ptcUy copious vapour may be mccji rising from it ; but tlie oil 

* ykholwm'i JiMir. xn. 16 1. t Ibid. x!x. Vit. 

t Falironi, t'rvll's AomI*, 1797, Ji. 193. S Shaw's Hoyle. ii. U9. 

hmL 1 Briison. ** As j)teiiarcd ia Irdaiul Tor luavkiecr). 



0-92a to 0'»47 





' . 0-8196 

evaporate till it be beated Botiiat poinL 



docs not begin to boil lill it is lieat«<l nearly up to the temper- 

~ ature of eOO".* At that u-mperature it may be distilled over^ 

but it is uln-n)'9 Homowknt altf n>d by the pioo-SK. Some niilrr 

and acetic acid a^vm to foe formed, n little charcMil reUoiiiB in 

the retort, ami the oil obtained is lighter, more fluid, and has 

a stronger taste tlian before. Oil, thus distilled, \nts formerly 

disiitifpiUhed by the name of jAUotophieal oil. During th« 

distilliiiion R prcat qtiiuitity of heavy ititl^iininable air in obtained. 

Fixed oil wlicn in the stulo of ^-jiponr, tiikcs fire on the ajw 

Ifiroach of an ignited body, and hums with a yellowieli vhite 

Bfttme. It in upon thi^ principle t)ial candle? and Inmpe hum. 

r ^lie tnllow or oil in fint eonvi-rted into the state of vapour in 

the wiok ; it tbvii takes fire, bihI supplies a RufGcieot quantity 

of heat to convert more oil into \lipour; atul thi» process gocx 

on while any oil remains. The wick is ncccjisiiry to prcseiita 

BuHieiently small quantity of oil at once for the heat to act J 

upon. If the heal were suffitiviilly great to keep the whole ■ 

tn\ at ihe u-mpenUure of 600°, no wiok wonid be neeeMsiry, as 

is obvioiu from oil catebing tire KpoiitaiteouRly whitn it tins been 

raised to that tempentture. ^'hen oil is burnt in this manner, 

eitlier in the open air or in contact tritb oxygen gas, the only 

now prodiicM obtained are ittiier and ear/ionic acid. 

M'hen exposed to the Action of cuhl, lixeal oils lose tlieir 
fluidity, and are oonvertetl into ice, but the freezing jiotnt i-arics 
in dilTen'iit ail*. 

4. When fined oils are exposed to the open air, or to oxygen 
gaSj'tl'ey undergo different clianges according to the nature of 
the oil. All of them, us for as experiment has gon»", have the 
property of alworbtng oxygen, and by uniting witli it they be- 
come more and more viMriil, and terminate at hist in a solid 
state, being np|>arenily Kaluretetl with oxygen. Now there are 
some oiI« that retain their tramqiarency after they have bccooic 
solid ; while othent become opaque, and assume ilw appcanmcc 
of lalioH' or wax. I'bis eircMmslanoe ha» given occasion to the 
division of the fixeil oila into two cIiism>8: Those that remain 
tran>|iiin'nl are calU-d ilrtituff oilx, while those Uuit become 
opiMiup are called fnt oils. To these two we may uiUl a third 
chiss, namely, those that are pre«ente<l by nature in a solid 
stale, which we shall i-nllu>li<l oiht, Leius taheaviewoftliese 
three classes of fat oiU !n succession. 

• Linaeed oil, accofJIntc to Mvneau, boil* at iWC. Ann. de Chim. »c. 
let. Wlinle ml boit« nt C40*, viil may bv heated up lo SM*. AAcr being 
dUlillcd over ii bciljt M \\(f. 




, I. DfyiiOT OtU. 

be principal (lr3rinB^ oilt atv lh« ftillowuiK '■ 



). i,inH-«<l oil. from lite scvds of Uiiiim uNiutbeimum. 

"2. Walnut oil, from the seeds of jugbnt rc^ta. 

■Il H(^ni[t <a\, from tlxf seetU of omnabis esliviL 

4. I'ufipy oilt from tin: »epAn of |3Gipavcr somniffnim. 

6. Outor oil, from tliv s^nAt of rkiiiiiJ) i^inmuim. 

8. Croton oil, from dtc seeds of crutoti ti^liiun. 

7. GTB|>e-see«l oil. frata tlie seeds of vitis vinifiYii. 
El. Ntf{h»bnile niL from llie seeds of atrojw l>i?41adoniui. 

9. 'I'ohftcc-o oil, from the s«edfl of nicoliana tabocum. 
">|0. Hpnt)an««il, from tlie mwIs of liyowyamus nigrr. 

II. Sanfk>W«f oil, from the m.iiU- of lioliiuillnis annuus. 

I'i. CreSB oil. from the si-eth of li-pidium KtUvmn. 

UoubdcEs drying oils may be obifiineil likewtsv from various 
crtiiT plants. 

Tlwse Otis, ill Uieir niUiind stato, po«seM Uie property *f 2S^ 
ibytn^ iiiU but impvrfrctlv. To pn-jum- tlifm for the use of 
the paiouv iuid i-iiraish-maker Uiry are boik-d for »oflu> lime in 
a iron pot By this process tbey wm partly decompofle^t; 
lUtadance of watery' vapour and of carburctlnl liydn^itn gM 
il seponted from lliem. They become deeper colournl, iifi<i 
scqaint ffrrWer consistcnry. It iit common for some purpoe«A 
loset them on fire, to allow tbrin lo burn for some lime, to 
I'ltii^isli them by eoTcring up tlie vessel iti which tl>i-y are 
ewtained, and to eoutmue Uie bailing; till th«y acqiiin; tii* 
proper dq^rec of viscidity. By this ])coceM ihey lose ihcir 
aitctuouK quiilily in « |^-at tnriiMiro, m ns not lo leave a greasy 
Mud upon paper, and approach tho nature of rcsinN, with tliis 
dilierenee, thut tiicy do not become brittle, but retain a decree 
«f toughness and ductility nut unlike what in this country ia 
called iprmtgkl rosin, or rihoemakors' ra^in. It is common also 
in preparing the drying oils tu boil them with a little litharge. 
The chanfTi- which happens to the oila by ibis process has not 
been precdsely ascertained. Proliobly titey alMub oxygen from 
the air, and we know tliat they undergo a partitd dceompotltion. 
M'brii they burn for some time, their unctuooa quality n much 
morR completely destroyed tlian by any metliod wbieb hns yet 
been pmctiHtKl. Hence it is followed trequently in preparing 
the drying oiU for ramishcs, and always for printers' ink, which 
requires to be as free as pouible from all iinctuo^Ey. 

Kut oil has been found preferable to all other oils for priiXen' 



rrtatm' ink. 

itxuf. ttL iak ; tliougli the dark colour whidi it BC(|uircs during boiling 
renders it iiot so proper for red ink as for block. Linseed oil 
is coiisidi'ri'd at next aftt^r nut oil in ihw respecU Otlicr oils 
oiiniiot be employed, because tliey cannot be «itiffiriciiUy frewl 
from tbcir uiicliioNity. Ink mtulc witli tlHwn would be »pt to 
come off and ainvKr tliu puper while in tli« haiidii of tb« book- 
binder, or evtiii to spread beyond tlie murk of tlie Ij-pes, and 
stain the paper j'ellow. Tbe proce«a for ptaking printerii' ink 
18 a* folluvrii : 

Tbe oil w niiKlft lo boil in ui iron pot only luilf filled, s«t on 
tire, and allo^^'od to burn for half an hour or more, then boiled 
^iitly till it acquirer the proper coi»iMence. In tltiti state it 
xa cfllled tfav roT-KMA. Two kinds mv prepared, n thicker uul 
a tliiiinor. The thicker is of such ii connotence that it dmi's 
into threads when cold Uko weak glue. Tlii* vaniUh is iiAcr- 
wurd< ground with lamp-black in the proportion of two oiincctt 
and n half to wsteeu ounces of oil. When newly prppared oil 
is uM-d for making ink, it is said to be itecewiiry to add n little 
boiled oil of tnrpcn'iiu; and a Hi tic litharge; but this is said to 
have the effect of causing ibc ink to stick so firmly to tlie typv«, 
that it can wilh difficulty bo remored. Old oil doM nntr«qain 
tliis addition.* 

Oil prepared by the procem above doKrribed, ts »till insoluble 
in alcohol and water, but it unite« rmdily tomor« oil. Ittlrie* 
into a lough mass like turpentine, and afterwtutlK U vcarcelr 
»u«ccptilile of uniting with oil. Dr. Leww fotind that tinxrcd 
oil, when thus converted into a thiok vnnilMh, Imt jLih of its 
weight; when boiled till it boaune quit*- stiff when enld, It lost 
nearly one-half of its weight.f The property whicli printers^ 
ink has of adhering to moistened paper &bown (luit (he oilv 
nature of tlic b<Kly is greatly altered. In some rospecu it h» 
nppronclxxl llie imture of mudlagv, Uioiigh in others Uic <Uffer- 
enco is very great. 

II. Fat OiU. 
The princi(<«l f:it oilt are the following : 
I. Olive oil, from the fniit of the Olea Kuropo>a. 
Q. Almond oil from the amygdalus communt*. 
.1. Rape oil, from the brasHCft rnpa. 

4. MuMtnrd oil, from sinapis alba ;uid ni^m. 

5. I^umb oil, from prunuH domestita. 




Lewis, Phil. Com. p. 371. 

t IbiiL I*. ST2. 


6. Beech oil, from £n^* sylvitue». 

7. Hoxvl oil, from coryliu avcUana. 
Oil of ante. 

Oil of ?tnp>> 

10. Trans or wlmJe oil, 

11. S(>eniwtceu oiL 

Wliru oil IK [Mtuml upon water, so as to form a tkin layer 

CO ibsill&cr,wid ts in tlmt tnitiuiorexjxtsrd to tlic ntin««))1icr<', 

tKew changM arc prodiuW nnu-li woiicr. Ik-niu>llct, who tirst 

eiamined tii€«e phenomona with Btt«i)tiaii, ascril^ed tliem to the 

Mtitiii ol'li);lit; but Seniiebicr obser\'efl llmt n» nuch clian^e 

«M pr*>(luL-«(l on tlu! oil llioui^ii «\'er m> Ioiiq; exponcil tn tho 

lil^:, provitled atmectpberical air wn3 fScliKli'^i ; hiil that it Ivok 

^Boc III) ihc a<lntmion of «ayKf» ff"*, wliutiicr llic oil wui 

tx|^(MFil to tlic li|{hl or no4.* It onuiiut be doubted tlieiii that 

itb oirin^ to the action of oxyt^cn. ll in supposed at prcttent 

in be Uie coftseqiieace of tbo simple abaorptiuu «J' oxygen and 

in t«nUDati<Hi witb tbe fat nib. 

111. Solid Oili 

Th« principal solid oils arc tlie following : 
1. Cacao butteri from thciibromn cacao. 
JL Fain oil, from cocos bulyiacca. 

3. MiMMt lwl«un, from myristira officinalis. 

4. IjiutvI oil, from lauru» iiobilim 
£. Japan wax. 

6. Myrtle wax, from myricn cetifora. 

7. (tciea' wax. 

d. Ci>cu oil, from cocos nucifera. 
9. BuUur of fraliim. 

10. Hog'a lurtL 

IL ConuBon buttor. 

I9L TaUow. 

lliese fwlid bodies ditTor from each otlicr %'cry much in tlic 
Unperatitre at which tliey become liquid. Palm oil, which is 
used in tliiti country to give common sonp a yellow colour, 
nelta at 64^ ; jajMin nax melts at uWut 9^". 

We arc indebted to the invoitigatioiis of Cbcvrcul for a 
peat (lejil of important information reiipecting tbo fixed tMla, 
He awciTtaincd tbiil lliey are all compounds ooDStHting of two 
or three different Bubstuuco*, wliicli may be eepuniU'd by 

■ Ann. dc Chim. xi. 80. 




procMaes which he pointed iMit. These mibstances he has <lLt- 
tin^uiifliod l>y tlic names of utrarine, rlttint, cetitie, jffiocntinr, 
bnlyrine, hirdne, aiiil c/tattistirnnt: Kel iw t»kc » view of Uic^tc 
seven substaiioeo, whicli may bo consideroil as tlie 6nt prin- 
ciples or constiltieiitii of oily bodies in general. 



1. SteariiK. 

wmmj- Tilis Buh«tnnce wa« first (iewribed by Chevreul in 1814.* 

It Wikx pointod out likewise l>y Bnicotinut in 1U)5, who did 
not seem nnitrc of whut had been previously done by ChevreuL, 
or nl U-it»t took no notice of it.f m 

It appears from the experiments of ChetTeul that tallow and f 
animal fat of every kinil \% a mixture or combination of (wo 
duUiicl oily substaiiccH. 'Hie first of thefte, which i.i Hulid at 
Ih* tuuul toinperatiire of tlie air, h« has called tfairineil to the 
second, which i^Iiquidai the same temperature, he hus^ven the 
name of thiiK.^ From the experiments of Dracoonot it wouhl 
appear that the fixed oils of the vegetable kingdom have tbft 
same composition. 

rnsi-ioi^, Chi-vrcul obtained ttrartHt from hog's lard by tlic following 
process. The bird, purified as completely as possible from 
fore^i matter, was heated in boiling alcohoL When the alco- 
hol cooled it (Ic-poMiti'd white crystalline needles, which were 
Stearine. 'J'liis process was repeated till the whole of the lard 
was dissolved in the alcohol. || The strarinc thus obtained in 
crystals was dissolved a second time in alcohol, and allowed to 
separate in crystals. Hy this process the whole of the eluine H 
not sepurated from the stcartnc ; though probably tiie quantity 
which remains is not conttiderable. 

The method employi-d by Itraconnot was very wmple. and 
scorns to show tluit in fixed oily bodies the stearine and elaiiic 
are not in chemical combination; but merely mechani<»lly 
mixed witli each other. If the oil to be examined n-as Uquit^. 

* Ann. do Cliim. iciv. I if!). Sec nl-io Ann. de Cliun. xcir. 74, and 
ClievTful Hir In corpx jcnu, p. ITR 
\ Ann. ltd Chim. xciu. iHt. ) From ma>, tallow. $ Prixn 4X1W1, oil. 
I TI10 proccu i:i HTcntly laciliUled by uiing absolute ali-ohol. For the 
toliibility of xcnrinc, in nicolwl, diminwhca aX a much greater rale than the 
strcnph of Uiut liqnitl. Chcirciil found thut boiling bIcoIkiI of the tpu gt. 
0'7&06 dinolvcil more than itx vrci)(hl of tteurine. 

Alcohol of the ip. gr. 0-;92.& dtwolved >^)^< 
Alcohol of the op. ff. <f%Q& diiMlvcd f '^. 
Alrohol of the «p. p. 0*681 diawlrtd jgg. 

Ann. ds CUoL et Pbfs. il ; 



Jt to colA titi it MiigL'at(^. In thU congealed state 

subj<>rt«-(l lo ttron^ |>rc«iur« between folds of blotting 

r. Tlie plain* van imliilird by tlic paper, anil Uic su-arine 

iiied behind in n solid ntnio. If tbc oil to be e.xaniitied 

Itih already volid, it wn« not 'nNC!»ary to expose it to cold. It 

simpljr subjected to presstire betvt'een fold^t of blotting 

^■■tltirine obtained by ifipsp proc«s«i<« is wliito, brittle, and lias itomti*. 

HKHnriuit tbc apponnnicc of wax. It Itas little or no smell wlivu 

f pw*. It vi tastclr«, nnd prodnce^ no ebange on vogctubic 

bluCT. Stcurine from bog's lard becomes liijuid wlien beiUiHl to 

the tmnpeniture of 10!>*. But there is a eorHiilvrublc diScr- 

mte in the melting point of the stcarine from diiTc-rcnt bodies. 

IrW"! will appear by tlie following tabic." 
Sk-arine from human tallo^r fiiaes at . . 120° 
she«p 109 
K' oxen Ill 
P" I'Off 109 

duck 109 

It it folable in nleohol, but the stoarinc froTririiffereiit bodies 
nrin unnevhat in iu solubility. 'Diis mil appear by tbc foJ- 
loTiBg (able, f<ir tlio experiment contained in wliieb we are 
R«ii»e itid«bU'd to Chcvroul. 100 piirtt «f Imiling alcoliol 
trf tic specific gravity 0*7952, dissolve 

2l'50 of stearine from man, 
Hi-07 of Ntearinc from tlie sheep, 
IS-iS oFfttcarine from the ox, 
I8'25 of 8tvarinc from the now, 
9tt-00 of stearine from the duck. 
MTwn stearine is digested witli an alkaline siibslanct* die 
flMttvt ])art of it U converted into soup, only a small ]>ortion 
irfil becmnc8 the sweet ]>rineipU' of oiU, antl a slill smaller is 
Kttie Rcid. The foUoM-ing table, likewise drawn up by M. 
ClevTCul, gives the proj)ortion of stearine from different bodies 
lumcd into M>ap by the action of potash, and tbc proportion 
■tu continued soluble : 


- VII. 1 


e. ■ e ^ Portion saponified . 
St«anneofman . . ^ p^^^,, ,„ „hi, . . 

. 94-9 


■ Cbevreul t Ann. dc Cliim. cl Pliji. !i. 303. 

[|. '2 A 




Stearine of the sheep 

Stearine of the ox . 

Stearine of the hog 

Stearine of the duck 


1 Stearine usually crystallizes in small needles, and when a 
quantity of it. is melted and allowed to congca], the suiftee 
becomes very, uneven. 

Stearine &om man, when saponified, is converted into eua- 
garic add alone, while stearine from the sheep yields both mai> 
garic and stearic acids. 
caataMai. The Constituents of stearine iirom sheep, as determined by 
Chevreul, are 

r Saponified . 

;. Soluble . . 



' ' Saponified . 
i. Soluble . . 

. 95'1 


' ' Saponified . 
i. Soluble . . 



1 ' Saponified . 
;_ Soluble . . 







Tliis is equivalent to 

2 atoms oxygen, 

22-228 atoms carbon, 
19-92 atoms hydrogen. 
If we adopt 

I atom oxygen, 
li atoms carbon, 
10 atoms hydrc^n, 
it is evident that it might resolve itself into 
1 atom carbonic oxide, 

1 atom of a carbo-hydrogen, composed of 10 atoms carboB 
and 10 atoms hydrogen. 

EJaiiie may be obtained from ibe tallow of difTercnt animals rrrpmUdo. 
Clievreul'A pnx.'O^. He iliitHolve^ tbe tallow in alcubol, 
rUows die 8tearinc to cry»tAllizc, and ibeii distils olT tlie aJco- 

P^l from th« claijie. nmconnot's metbod nppcura of casivr 
execution, and will probably yioM claioe of greater purity, 
Ue procoreH his st«arine by sut>jectin|r (be tallow to preiisiire 
between folits of blotting paper. The pajM-r imbibes th« ciMne, 
To sepamie it bo Munkn tlic pajior iii u-utrr, luid subjects it to 
preSKure, tlw cbtiiie is forced out, and may easily be collected 
^and examined. 

^L It hu very much tJic appearance of a vegetable oil, an<l is r»i«iiiM. 
^^bfee liquid at the tt^Tiiperntureof 59", Sometimciit is colour- 
^^Sfeind doHtilutc of vmell ; but moKt comtiioiily it lias bolli, 
nrinf; to tltc presence of foreign bodies from wMcfa it is not 
pMsible to free it, Cherreul exa[Din«d particularly elaine from 
A< tallow of man, tlie xlieep, the ox, tlie hog, tbe jiifruar, and 
Tbe following are the pro))ertics of each : 
Ebime qfman — yellow, witliout smell, of tlic sp, gmTity 


S, Elaine of the aA«-/>— colourless, a slight smell of mutton, 
•!>. gravity 0-916. 

S. FJaiae of the o»-rcolourless, almost witliout emcU, sp. 
Stnity 0-913. 

4. Eiaine (^ the hog — oolourletf, almost without smell, sp. 
pinty 0-91 5. 

5. F./aine ofthfjayuar — lemon ycllotc, baring an odour, sp. 
pavity 0UI4. 

8, FJam. oftheffoott — olightly yellow, almost without smell, 
T- parity 0-920. 

Tbe solubility of these different varieties of elaine in alcohol 
rfllie 1^. gravit)' 0-7952 was as follows: 

1. IliaiHf of Mtut — 100 parts dissolved in 81-08 partu of 
bailing alcohol, ibc solution began to become opaque at 

2. Ehiinf of the. jiAr-T*— 100 paM» were dissolred by 81-17 of 
tkaliol at the tvm[K>rmlure of 167% the Liquid became muddy 

a. FJaine tf the ox— 100 parW were dissolved by 81 -03 of 
klodbol at the temperature of Il>7°, tb« liquid became muddy 
M 145". 

1 *'^"'iM at tt" Acff — 100 puTiB were dissolved by 81-08 of 



' CMpm. alcohol at the temperature of 167°, the liquid became mi 
at 143"|. 

5. Elaine ofthejagmr — 100 parts were dtssolred by 8 
of ^eohol at die temperature 167°, the liquid became mi 
at 140°. 

6. EkoM ofUt£ gooae — 100 parts were dinoKed hj Sii 
alcohol ctf the tempetature 167°, the liquid became mwUy i 
eooled dawn to ISi". 

When these different Tarietiea of elaine vere digested 
nifficient time with potash lye, by fai the greatest pari 
Mnrerted into soap. But the soluble portion, cdnn 
chiefiy of the sweet principle of oils, was rather greater 
the quantity formed when stearine was saponified in the : 
way. The following table exhibits the propcniionB of e 
saponified and converted into sweet principle, when the e 
riment wss made with the different rarieties abov« specifi 
1. Elaine from the sheep, hog, jaguar, and goose. 
S^onified . . . M 
Soluble . . . 11 

3. Elaine of the ox. 




To give the reader an idea of the proportion of stearbf 
ettioe in different varieties of fixed oil, animal and veg«t 
I shall insert the following table exhibiting the proportidt 

Beef marrow , 
Mutton marrow 
Goose &t . 

* Cberreul ; Ann. de Chim. et Phjn. n. 366. 
t Ann. de Chim. xeiiL SEA. 

nined by bis experiments : 

' i Elaine 

. 40 

. 60 

C Stearine 
* I Elaine 

. sd 

. 02 

C Stearine 
* I Elaine 

. 76 

. 94 

• i Elaine 

. as 

. 74 

* 2^ Elaine 

. 3S 

. 68 





Duck fill 

C Stcarliio 

. 38 . 
. 73 


Turicey fet 

' St4:imtie 
(. 1-liuirio 

. 26 

. 74 

Olive oil , 

C St^^arillc 
i_ Elfiiiic 

. 38 
. . 73 


Aimond <ril . 

C Stearinc 
/ bllaine 

. 84 

. 76 


Oil of cola . . S^.*^'"*' • • *^ 

^ Luune . 54 

llic eanstitueiitfl of elain*;, us dirterminnl by ChovKtil, are 


Wf Oxygen 
^H Carbon 



^K Hydrogau 




^^ lOO-Ot 
y<*c numbers are etjuivaleni to 

^^b 1 atom oxy^n, 
^^" 10-4^uUimH curbou, 

r 9-17 atams hydrogen. 

Pm we to adopt 

I atom oxygen, 
1 atomn cnrtMHi, 
9 atdinv Lydrogcii, 
Lbtlieirue cututttutjoii, then vu miglit comider it as a oom- 


I atom carbonic oxido, 

1 alum uf a aaho-iiyiirogen, composed of 9 atoms carbon 
and atoms IiydrogeA. 

I would reduce the difference between Btearioe and claiuc 
I one atom less carbon and byilrugen in the carbo-liydn>geii, 
' which the Uutcr is chiefly oomputtcil. 

a Cctinti. 

The Bpennaceli of commercr, rn>m whieh cetine wa* ex- 
baeted by Clievrcul, aluiiys conuiinis a yellow oil, frum which 
it wai) freed in the following manner : 

^ aOpartfl ofsperniacetifusiMe at 111" were triturated in 50 Pift^niion. 

^irta of cold iUcohol of the s(iecific gravity 0-gt6, and tlie 
mixture vra* left for '24 hours at a temperature of about (id" and 
ihen filtered. The undissolved Ti-jidiie was treated with 100 
parts of boiling alcohol in a flask, and tl>e whole allowed to 


cti4>.iiL cool. The crystals and the uDdissolved portion wen treated 
with successive portions of boiling alcohol till the alcohol when 
evaporated ceased to exhibit any traces of oil. The residual 
matter was considered as pure celine. It melted at the tempe- 
rature of 120°. 

mtaom. On cooling it crystallizes in white brilliant plates^ At the 
temperature of about 680" it may be volatilized without decom- 
position. It has a very slight smell, but is destitute of taste. 
It is insoluble in water. 100 parts of alcohol of the ^>edfic 
gravity 0*621 dissolve 2>6 parts of cetine, the greatest part of 
which is deposited as the solution cools in crystalline plates 
having a pearly lustre. Cetine produces no cbtmge on vegetfr^ 
ble blues . 

Potash converts it into ethal and margaric and oleic acids. 
When heated sufficiently in an <^n dish it takes fire and bunts 
like wax. Sulphuric acid gradually decomposes it when asasted 
by heat The action of nitric acid on it is simitar to theactitm 
of the same acid on stearic acid. The constituents of cetlncj 
as determined by Chevreul, are as follows : 

C"»F«*»~' Oxygen . . 5-478 

Carboo . . 61-660 

Hydr<^n . . 12-869 


These numbers give us the atomic comdtution of cetine as 

1* atom oxygen, 
19-8 atoms carbon, 
18-75 atoms hydrogen. 
Perhaps we may adopt Uie following atoms as cotnii^ suffi- 
cientiy near the result of the analysis, 
1 atom oxygen, 
20 atoms carbon, 
19 atoms hydn^n. 
This would make cetine a compound of 
1 atom carbonic oxide, 

1 atom carbo-hydrt^en, composed of 19 atoms carbon and 
19 atoms hydrogen. 
Or if we consider the carbo-hydrt^n as the same as ensts in 
elaine, then cetine contains only half the oxygen that exists in 

• Sur les corps gras, p- 170, 



4. PAocaiine. 

«M. Vll 


This otihsitancc was extracted by Chcvrcul from tin- oil »f 
tiiv ilfl]>liiiiu.i [iliocaona or oommoii ijorpoix, in tbe following 
maiiiU'r : 

1200 parts of pofpoiso oil wore mixcii w'lih 1 SO parts of atco- rnr^uion. 
boi of the spcciJic gravity 0-797 and Blij;;litly Iioatvil, ihe wliolv 
m dlMolrcd. AfUT 'J4 hours the alcohol wliich swiim on the 
•ur&ce of tlic oil was decanted oA'aiid diBtillcd. There remained 
u acid oil of tlic s])wific gravity 0*9'1l at tbe temperature of 
61". It was deprive«I of it« acid portion, and then treated with 
Viitk cold alcohol. liy tliiit invaiit pliocvnine was obtaine<l. 

It b n very iluid oil, baring a B])ociiic gravity of 0-954. lla mi-cRicx 
odour is ulight, but peculiar, and liavinjr »ame resemblance to 
llat of pboocitic add. It docs not act upon vifrcud)le colours. 
Alcobol dissolves ic in great al>undancc when ussistcd by heat. 
Wli«n a dilute alcoholic wlution is distilled, the phoccnine 
Tenaiiiliig has acid properties; hut the c|uanlity of iu;id fonncd 
ii very hduUI. When 100 parts of phoconine are treated with 
INAasb, tliey iire converted into 
l^ire ])lioceDic acid 

t Oleic acid, hydrous 
Olyocrine* , 

ct oi 




0. Butyrine. 
cvreul fouiul, on examining butter, thiit it contained two 
ivt oily bodies ; iK-sides a iwlid con.stitutin^ a variety of 
Utorine. One of these oils possessing peculiar properties, he 
gave it tbe name of butgriiK. lie obtained butyriuc by the 
following process : 

The butler was fijirt freed from all traces of biitlermilk. It i-wpuwii™. 
ms then cooled very slowly in a deep porcelain diMli, and ki'pt 
Jar some days at a temperature of OS", By degrees it jteparated 
bito a ^mauliir i>uIi!>tiinco, consisting of stearine, MtiU retaining 
a ocrUun imition of the two oils of butter, and u Uipiid I'On.KiNt- 
fnff of tlie two oils, still retain uig in solution aportion<»fstear]ne, 
"niis liquid [wrliun being filtered was found to possess the fol- 
lowing properties: Its colour was yellow, and its taste and 
•mell similar to that of butter. At 66^ its specific gravity was 

* By thn a mcnnt the .luwl |>nncii>le armla tliacovered by ScIicl-Ic. 
■f Cbcvrcul, Hir tu cotjik gnu, |>. ItW. 



|,.aw m. 0'922. It did not act upon blue vegetable colours, 100 parts 
' ~" of alcolioi ot" 0"821 dissolved 6 jwru of it whoii a^^istcd by a 
boiling beat. 

88 parts of this liquid oil were mixed in a flask witb 66 parts 
of ulcobol of tlic specific gravity 0'7ftO. ITic mixture «» 
a^tated and left to digest fur '24 buiin in tlie temperature of 
66*. The alcohol «-*» drawn off alter 24 houra, and replaced I 
by 176 parts of new alcohol, which was dtaun off in ifH luni 
uft«.T 21 liount, and 17(1 parte of new alcohol substituted. Thit 
last portion dissolved the whole, but when the alcohol was 
allowed to cool, a portion of oil precipitated. Tlie alcohol 
was separated from the solution by a cautious distillation, 'llie 
residual oil containeda little acid, which was ri'moved by dige»> 
tion with magnesia, mid then'w'iuhing witli water. I'hiui puri- ■ 
fied it was butyrine in a state of purity, f 

pispenin. Butyrine thus obtained is very fluid at 66°, and has a specific 
gravity of O'OOB. It is usually yellow, but this colour is not 
essential to it, an some butterH give a butyrine quite white. IC fl 
bat a »mcll similar to that of liuttcr. It does not ciinReal when 
cooled down to 32". Il has no action on vegetable colour*. 
It is insoluble in water, but alcohol of the specific gravity 0*632 ■ 
dissolves it in any proportion whatever, at a boiling tempera- 
ture. Asolulionuf 20 p.^rts of butyrine in 100 alcohol becomes 
Opaque on cooling; but 120 parts of butyrine in 100 of alcohol 
remains transparent. When tlie alcoholic solution is distilled 
the butyrine becomes acid, a small quantity of butyric acid 
being developed. It is rvadily saponified, cind by the process 
is converted into butyric acid, margaric acid, and oleic acid ; 
together with about 12'.'S per cenu of glycerine. 

6. Hirciite, 

Hircine is a liquid oil, which exists in the tallow of the deer 
mid the slieep. It is it which forms unlh elaine, the liquid 
portion of tallow. It is characterucetl by yieliUng hircic 
when saponifies!.* 



7. (.'Aolet^eriNe. 
This name hits been given by Chovreul to a &tty matter like 
spermaceti, which consdtuCes the principal constituent i,>f biliary 
ealculi, and which Fourrroy had diKtingut^hcd by tl>e luune of 
adipocire, Choleeterine tnny be obtjiined by washing 

Clicvmil, Kur ks corps grw, \>^ l»l, I9&. 

humiia 1 



y culctiti with water, and then dissolving them iii boiling *«* v"- 
kot olcoliol. As tb« solution vwiU tlie cholesterinc b deposited ' 

|{n crj'Htalline pktcg. When thtitv iire wasli««l in alcohol, tatd 
irird. iliry conMitute pure cholr«(orinv. 

It is aulid, white, aini possessed of coDfiidoroblc lustre. It 
nelta wlien heated to 278*. When allowed to cool slowly, 
Itrt t>ein|ii; hrought into a state of fusion, it crjstaUiiies in riuU- 
Ittiin^ plates. It has no ta>lc, nixi i.t nlinoMt destitute of siiii-U. 
|AtOtiO*'iliRnybevolatilizi-dwitliuut uiidi-rf^uingdc^cuuiposiuon. 
It in insoluble in water. 1 00 portx of boiling alcohol of the 
rific gravity 0-816. dissolve 18 jtnrtis of clwlestcrinc. But 
Ftt the s)>eciiic gravity- of the Hleohol bf 0'B4i>, it will dissolve 
only 11-24 of llits substance. l*he alcoholic solutions on cool- 
ing, depmtte nmsl of the choleslerbe in CT)-stals. It Ims no 
iielion on vegcliible blues. It give.i out no wiiter when hoali-d 
with protoxide of lea<l. It ciuinut be converted into a soap^ 
not doe* it undergo any alteration when digested nntb potash 
l»j'. When heated sulhciently in an open dinh it burns like 
nx. Sulphuric acid decomposes it when assisted by lieaL 
h '» also dccum)>o«ed by hot nitne iu:hi. It^ constituents, a» 
^ Jffc nnined by the niialysis of Chcvrcnl, are as followx : 
^^^ Oxygen a-02d 

^^H Carbon 85-095 

^^P Hydrogen 1 V&dO 

m 1 00-000' 

r ^pJB a equivalent to tlie following atomic quantities: 
f 1 atom oxygen, 

S5'8 atoms curbon, 
31-4 atoms hydrogen. 
If ire admit tlie atomic constitution to hu 
1 atom oxygen, 
80 atoms carbtni, 
31 atoms hydrogi-n. 
I obvious that it cannot, like the prec-eding bodies, be resolved 
mrlxMiic oxide aixl cart>o-hy«brogen. But it might be 
Ived into 
I atom carbonic oxid«, 
1 atom carbo-hydrogen, consisting of 27 atoms carbon and 

27 atoms hydrogen, 
I atom su)HT-c»rburcUe4Uliydrogen, consisting of 8 atoms 
carbon, and 4 atoms hydrogen. 

* Chcireul, tur 1«* coriw ff»a, p. 153. 



f Clu(i.I1L 


An clabomte set of cxporimonU lias been nuule by M. <1« 
f>tiiissiire, to detennine tho elementary conititiitioii of Hcvenl 
of the Ssed oiU; but no very important concluBions could ht 
drawn from such nnulyHea, uolewi the different substances, of 
which iilmoat all these botli«!» arc composed, tiad been previ- 
ously insulated, and analyzed separately. The following table 
exhibits the results of Saussiire's analyses. I liave introduced 
likewise a few other analyses of fixed oils made by other 

" " lolU. 







Linseed oil 






Nut oil 







Almond oil 







Castor oil 






Olive oil 


11 -5 4 5 



100 ' Ditto. 1 

I log's lard 
Train oil 


11 -632 










Spermaceti oil 






Oil of ants 

61 -.30 












Uet>8 wax 

























Ebiine of 7 
liogHlnnl 3 

Steariiie of ? 
olive oil 5 













When the fixed oils are saponified they are converted inlo 
tlie various fatty acids described in tlie first chapter of this 
volume, and into glycerine. Cbcvreul consider it as probable 
that they are compouncU of glycerine and lliesc iK-id bodies, _ 
haring in tliiti re^peet some rencmblcuiee to the add ctherx. fl 
Tlie alkalies, by eombiiiin|r with the acid, set tlie glycerine at 
liberty. It would not be easy t« verify this conjecture by ex|)e- 
rimcnt. Our mode of purifying the ditferent conslilueDtM ot 
tlic fixed oils, such as they have been described in this sc«tioiir 
and obtaining each in a separate state, is too imperfect to w 
nmt much confidence in the uccumcy of the analyses tliat have 
been miwie, or to enable us to deduce froin iheiu ouocluaions 
of much importance. 



The fi.Tc<i oils are all insoluble in vmter. Wlion t^tAlcd *«'■'"■ 

tb that liquid, tlic mtxttirc bcc-omi's inillcy, but the inly pur- [■nq.mi^ 

,eg tfriiiliuilly wjMuntc Mui Kwim upon the siirliicc. Tho 
ncL- of a mucila^nous substance, us gum arnbtc, prevents 
tl»c oil from wcpnratinff, imd occasiotis, of course, a permanent 
miikincm. * Such mixtures are called anuMoas. Tbey are 
often formed by tritumlinf;; oily tieedfi, a8 ubnondH, wilh u-ater; 
the two ingredicnu ncciGiwary to form an rniidiuoii, oil and 
nudlage, being prcwjii in llic Kcetl. 

Mott of tbe fixed oils are hut Kpurinf^ly soluble in Dlcohul. 
Mr. Brande fnuitd tluit very little olive or nlmond oil nits taken 
Up by alcohol of the specific gravit)' O-B-JO. Linseed oil is 
Hore soluble, and aloobol diwiolveH any quantity whatever of 
c&itor oil. On tlint account tlii.'S oil in soiuetime<i employed to 
adulterate volatile oils of high N-aliie, espeeiaily uil of clove*,* 

In general the fixed oils are somewhat more soluble in sul- 
phuric ether tlum in alcohol, Four measures of sulphuric ether 
of the specific gravity 0-7563 were found by Mr. Hrande to 
dJMolve 1^ measure of almond oil, IJ measure of olive oil, 2} 
measures oflinseed oil, and any qitaiitily whatever of ctuttoroiLf 

The fixed oiU unite readily wilh each otlier, witli vobitile 
oils iind Itkewitic with bittuiiinoux and rcsinou.s subsbuicn;. 

The alkalies unite readily with tlic fixed oils, and form tho 
important compounds called soaps. The fat oils enter into 
theae combination.'* inorir rca<lily tliaii the tlrylnif oiU. The 
earths likewUe combine wilh these oily bodicf, and fonn ii kind 
of Mop insoluble in water, and ore therefore not capable of 
bdnff ^plied to the same uses an common soap. 

The combustible acids, as far as is kuoivu at jiresent, do not 
anite wilh oib; ueitlier has tlie muriatic acid any remarkable 
effect, llioaphoric acid, when concentrated, deepens tJieir 
Colour, and gives tlicui a peculiar smell, especially if aw<i«ted 
by beat : a proof titut it act« upon ihem^ 'Vbe sulphuric acid 
acm witli much greater rner^. The oils become immediately 
hladc, and assume gradually the properties of bitumen in pro> 
portion to the continuance of the action. If the acid be allowed 
to remain Utug enough, they are completely dceompuw-d ; waU-r 
b fonned, charcoal precipitated, and an acid evolved.} Other 

* [liiLTnns. Iflll,p.8«4. 

t IbliL EqusI voliitiics of niilphiiric ether nnd outor oil united together 
hat beea foinil a useriil c:tlcnia1 ap|kliciition in rhcujnutiaiu. 
t VJpmciis Jc Oliimia i>f Lli« Dijon Aodcmj, iti. 142. 
( ^^nl^tf(lJ, vii. 330. 


' ***^ *"• products <loiil)lle»» also mukc tlit'Jr n)>p«ariijiec, tbough 

action of thisDcid on oikliusnot yGtbcrnextuniiicdwithflufficieiit 
care. Nitric acid acts witli still greater eiiei^'. W'beii ]iour«d 
auHdcnIy upon the ilryinjr oiU, it sew them od fire. 'Ilit- (uune 
effect is proihu^i-c! upon llu- Jiit oiIj*, pruviilit) the acid be mixeii 
preiioiiily with u porlioti of tlic sulphuric. When the uiuie 
KCid IS BuHicieutly diluted, it converts the drying oils into a 
yellow rcsinou§-like muss, ao4l the fat oiU to a subatanoc very 
like l:tH()w. Hut the iictioii of tlii« avid upon fixed oila baa not 
yet been miffieiently examinvd. 

Many iittoinpts have been made by chemists to form pcrnia- 
ni-ut ooinpounds of the concentrated ncids and oil-s under the 
name of acit/ soaps. The only acid whidi was found to aitswer 
wat the sulplmric Acliard published a number of experiments 
on t]iet4e compounds. They dtsiolve in wateri and latber like 
common HtKip; but an tliey are not in reatily permanent com- 
pounds, tJiey cannot be u»c<l with mueh prospect of a4lvanti^e, 
'Ilie fixed oils acts (though feebly) upon »«me of the metak 
when the atmospheric air is not excludetL Cojiper ht mkwi 
corroded by them, and a dark green solution obtained. The 
only otlier metal u])on which they are known to act in the same 
manner is mercury, ily tri[ur;iting mercury with fixed oils, it 
gradually disappears, and a bluish coloured unguent jm formed ; 
coiuti.tting, in part at least, uf the black oxide of that metal 
united to the oil. But lliis experiment scarcely succeeds, except 
with those oils which are in a state approaching to solidity. 

But upon the metallic oxiiles tlie tixed oibi act witli greater 
ener^. They disaolvi- tiio white oxide of arsenic with great 
fiR-ility, as was vhown long ago by Urundt. When Wiled vrilii 
tlie oxides of nicrcurj-, lend, or bismtith, they form very tough 
solid oompoimds, called plasters. 

Fixed oils are liable, by keeping, to undergo a change well 

known by tlie niuiie of ratifri'lilp. They become thick, av(|uire 

a brown colour, an acrid taste, and a diMi^reeuhle siiiell. The 

oil thus altered converts vegetid>le blues into red, and of course 

^ contains an aci<l. It is believed at present that tJiis eluingo b 

H owing to the alteration of the foreign substances present in oils, 

H or to tlie action of those foreign bodies upon tlie oily utatler 

H itself. ISevend of the fixed oils wiien neuly exlnietcd, let 

H 6dl on standing u qunniity of mucilaginotis matter ; and frem 

■ the ex]>erimeiitx of Seheele, it ajipears probuhle that they always 

H retain less or more of a similar principle. He l>uile<l together 

H one port of litiiarge, two parts of olive oil, nnd a little water. 




^luHi Ui« oil luul arqiiirc*) t)iu coiisistciicv of an ointnont, it BM.riii.| 

I wtu allov«il to cool, anil tti« iratpr decanted off. When this ~ 

WnliT IH <'\'n|MirTtt<.')l to llie ciiiukUtpiice of a Hjrup, it ltMt\'<!g a 

KulMtaticv wliiolt ScIk-i'Ic toniu-*! lUe siivet prindfje of oUs, It 

doM not irrjrstalltztf, is soluble in water and ulcoliol, and is con- 

terled into oxalic acid l>y the action of nitric acid. Wlicn 

bcntrd, it is [tartly decompcpwd tnin n brown oil, luid jMrll)- 

rolutilizcd iinalterML Tliii »uli8tuiict> lie obtained also from 

linseed and rape-wed oil, and from oil of almonds. Even the 

oil disengaged from soap yielded liim a little of it.' Similar 

B ImpuritieH were supposed to exi«t in all lixe<i oilx, and to occa- 

^■Im tJicir rancidity liy putrofaction. 'I1it» roiicidity is in some 

^^^■toe diminished by ii{^(Rtion with u-atvr, but not eompletely 

^RSttroyed. Mr. Dossie lias •ihown that af^ilatioii with the Hxed 

H tiudtiie soltitiuas and qiiiciclime aiiswcm the purpose sulfic-iently 

well in pnrifying oils for burning in laQi|M ; bnt tliat titoy huv« 

Om pm|»erty ofcrui^ilatiti^ a portion «f the oil. This however 

nty b« prcvftiUil by adiling n (|uaiitity of strong brine, which 

•ocasions the separation of the foreign bodies from the olt.t 

^^^H fiECriON VIII, ^K>lr HlTti'MENS. 

V Tb» term l/Umnm hni* often been applied by chemists to iill 
B tit inflammable siibiiuuceit tliat occur in the earth ; but this 
■ me of the word is dov so far limited, that guljihur and meUitc 
H are most commonly excluded. It would bo proper to exclude 
' ambrr lUcewisc, and lo apply the term tu thow fossil bodii-x 
only which have a eetlain rcM^nbhuice lo oily und rc^iiioita 
ntbMwioes. In tins restricted sense the word is used in tlie 

if rewnt tection. 
Bituminons snbstanc<>« may be Hubdividetl into two classes : 
■■Dely> hituitmiovi oiln an<I /litumftu:, properly so cnlle<l. The 
firai set [lowem ne<rly tiie properlii-:« of volatile oils, and ought 
Sn Urict propriety to be clas»e<I willi theHe bodies ; but as the 
rhemical properties of bitumens have not yet been investigated 
witli much precision, it was deemed rather premuliirc to Be|>a- 
rate them from each other. The second set possess proper- 
ties peculiar to thrmsclres. Let us endeavour In descrilw tlic 
Bub»taaces belonging to these two cloaact as fiij us pussible. 



1. BihrnttHOHs OiU. 

Only two tfp«cies of bituminous oils have been hitlierto exam- 
ined by chcmisbi. Otlion indeed luive bevn mentioned, but 
■ Schede's OpuK. ii ISO. f Nkholwn'i Joar. v. i>. 





"^'"- their existence lia» not l)ocn iufficiently aiillionlical«H. ThcMC 
two s(>cc-ii.-s HTi.' cckUcd petroteuni, and raoMa, or sea-icaT! the 
first is liquid, the Bocond solid. 

1. Petroleum w an oil of h brownish yellow colour. When 
pure, it t!) as fluid m w»tcr, and very volatile.* Its S)>ecific 
gmvity varies froui 0'730 to 0*678.-|- It lias a peculiar nndl. 
Whcu boated, it may be distilled over without alteration. 

IVtroIciini U fontid in the earth in rarious stales of purity ; 
Hometitnes without any mixture of foreign substances. In this 
State it is usually dUtinguUlied by the name of naf^ilha, aikI ic 
aaidtooccuriu^rcntabniidnnocon thoshori>Mofthc Cu^spiau and 
ill Persia. It occurs also in different parts of Europe, especially 
Italy aiid Gemmiiy. When less fluid and darker coloured, it 
is commonly called petroleum. It is supposed to owe this 
increft.«ed spisMitude and deepened colour to tlie action of the 
air. When distilled, it yields a fjiianlity of pure petroleum, 
while a portion of bitinneii of the cuiisistcnce of tar or pitch 
ronia'iiiM behind. When long exposed to the air, petroleum 
becomes blnek, and iicqiiircs the semifluidit)- of tar. In this 
Btate the greati^sl part of it is insoluble in alcohol ; so that it 
* has assumed tlie state of true bitumen. 

Petroleum is used in those countries, where it abound as 
en oil for lamps. It is employed also as a solvent of reainotu 
bodies, and of the proper bitumens, wluch it dtssolres with 
UtiMitK Wlien petroleum is distilled nt a low Iieat, the liquid which 

comes lirst over Is distinguished by tlie name of naphtha. It 
Is colourless, perfectly fluid; i» very volatile, and hiu n \wea- 
liar smell. Coal tar, or the oily matter which comes over when 
coal is distilled at a red heat, yields, when repeatedly rectified, 
the very same kind of liquid. Naphtha b observed also in dif- 
ferent places rising spontaneously from the earth nearly in a 
state of purity. As, for exnmpte, in different parts of Persia, 
at Amiano in Italy, and in many other place^i. This natural 
protbietion of naphtha is observed in many places where no coal 
has been ever discovered. Yet I think it not improbable, from 
the exact similarity between tlic properties of natural iiaphlha 
and coal naphtha, that tlu<y have in n.>ftlity the sami! origin. 

* The volatility seems to liave been over^stcil by older chcmiml writer*. 
On tnlxiiif; wvll rectifieil iietrolfum with wuter in a retort, I fuiintl th*t th« 
outer i.'otild bu Kn<\\\y diBtilled over in a moderate heat, wliile the «faole 
pi-troteiiRi remained behind. 

f See KirwMi'a Minenlogy, iL 42. 







0-81 ?• 



TTie specific gravity of naphtlm varies coimdombly, probn- 
hly according to iu stale of purity. Tlie follon-ing are tbo 
ipmfic gntvitie«i wlitch I luive iny»>elf a^tc^rtaiiipt). 

I, Poniui luiplilhn, not rrctiiicd . 

S. Coal iiaplitlui, perfectly colourless . • 

3. Coal naplitha, sliglitly yellow . . 

4. Natural iiaplillm of Amiano 

5. Ditbs thric« rectified 
Naplitlia is very volatile: a drop of it let R»ll on paper dift- 

^pean iii a few minutes. Yet ibt boiling point is rather higher 
lAm that of oil of tarpentine. I found that Persian naphthu 
htpm to boil in f^la-is at tJie temperature of iiitt". A.« tlie boil- 
uig conttnueii tlie temperature t'lue^, I mised the lompcrature 
of Pefsian luiphtba in a Nilrer ctip an High iif di>'2°. 

At tlic temperature of 7'2'5' the vupaur of naphtha is capa- 
ble of supporting a column of mercury 1-78 inch in Lelfrlit. 
M. T. dc Saussure determined its specific gravity by wcigliinjf 
k mixture of vapour of naphtha aod eomir un ulr. I le olitaliied 
flIflBS a<t the K|>ecific gravity. I trint the specific gravity of 
(be rapour of Peraiitn naphtha at tbc temperature of 53" by ilie 
Kime method, and found it '2-263. Siiussurc'a experiment Wiis 
■ude at the temperature of 72-y. Probably, therefore, the 
ipecific gravity of thi.* vapour increases at a great rate with tlic 
temperature. When the «ipour of naphtha is mixed with 
mnmon uir, it is not ea«ily removed iigiiin. It may be passed, 
wilhuul alteration, through water. Alcohol would no doubt 
•iMorb itf and a considerable proportion of it would be condensed 
by the freezing temperature. 

Naphtha burns with a strong yellow flamo, and a confflder- 
abln smoke. 

It is insoluble lu water ; though it commnnicates its peculiai' Prai<«iitt. 
tametl to tliat liquid. Alcohol dissolvea about j.tli of iu weight 
it Sulphuric etlier, petroleum, fat oil*, pitch, volatile oil* 
leMBbine with na|»htlia in every proportion. It diMolvcs wa^t 
' by the nmstnncc uf heat, and allows » portion of it to fall down 
•l^un iH it cools. Caoutehuue swells in naphtlia to more tluu) 
{ 30 times its bulk, and becomes gelatinous and transparent ; but 
[ tcarcely dissolves. However, by this means it is easy to loould 
itcbouc into tubes of considerable service to tlic chcmist.§ 

* It had been naaniiracturci] in Eijinlnirgh. 

t ll hail ticcn nmnurocturcil in Oltugow. 

t IVtcrmincd li; SaUMUrv, AnnnU of PlnloiO))h]r, x> 110. 

i Uf >lr, Kjriiic'o ps|i«r, Ainiala or PliiloM«|)h]r. vIIl 1 1V. 


c»w iH- Naphtha diseolvcs a Utile sulphur and phosphorus 

assisted by heat, and lets tliem fall agauu in tlie state of crystiil^' 
Neither lliv Hxud alkalifn nor tlut stroiifi; miiKrrid acidif Itavc any 
mariced action on naphtha. It is known that anhydrous pciiash 
combiites nitli it and forms a brown soap; but the hy<lrQtiN 
alkaJies <lo not uuice with iu It absorhs ubout S| times it& 
volume «f nmmoniueid ga^ I 

Wh<'ii nitphthii is [KKscd through a rcd-Iiot por«'Iniii luW, 
it ia converted into charcoal) a brown empyreuniatic oil) whichf 
when sublimed at tlie temperature of 95*, yield:) a portion (4 
colourless cryxtuU in rhomboidal plat^*!*, Iiaring a lu»lrc simikr 
to tliat orHpi-rmaceti.'uiul a (juaiitily of caTbur«lte<t bydrogea 
gas. Theodore de Suussuro attempted to aimlyzc ni^ihtha l> 
detonating a mixture of the vapour of naphtha and onygeti gal 
The result of hit c-xperimenta wan, tliat 1 rolunie of vn|M>tira 
nuphtlui requires for complete combustion 14 voIujucs of osyi 
gen gas, and that after the combustion tliere remain 8*'2 volumai 
of carbonic acid gas. Of consequence 5-8 volumes of the oxygd 
must have gone to the formation of Wiiter, m tliut the hydro 
gen in I volume of vapour of luiphtha, if in a separate Htaicj 
would amount to II '6 volumoB. This would make naphtha 
vapour a comjiound of 
ci«i|«iiiiiii, g volumes carbon vapour, 7 . j • < 

12 volume* hydrogen J •'""^^"'^'^ """ «"« ''°^'""< 

Hence its specific gravity xhouli) l>c 4'14>66, aiid its aloni 
weight 7-5. It ia a compound of I'J atoms hydrogen ottd 
atoms carbon. So that the atoms are in the proportion of 1 
atoms hydrogen to one atom carbon. Thiut naphtha diffei 
essentially i» its constitution both from alcohol, ctlicnt, and cttU 
I subjected nuphtlui from I'er«i;i to analysis by hcatiing it 
in a copper tube along with peroxide of copper. One grain of. 
naphtha by this treatment yielded 6-5 cubic uichcs of car' 
acid, and 1 -.^5 grain of water. Now the hydrogen iu \'!i3 p. 
of water is equivalent to 7 cubic inches, Hn<l the carbon in 6-f 
cubic inches of carbonic acid i» equivalent to 6-3 cubic inehM; 
Hence naphtlia is composed of 

6-5 volumes of carbon, or IU volumes, 

7 volumes of hydrogen, 14 volumes. 

Subtdtiiting atoms for volumes, we have naphtha composed of 

* Ilia I conudcr m the ume wriib the aubstance firal rwiionl by Mr. 
0>rdio(ABMba(Pliili»ophy, XT. 74). I hare sanlytied it, and ibuiulita ' 
eOMpCuad oTS atooM atboa + 1 aloai hydrogen. 


la atoms ctu-boii . . s; 9-75 smviii. 

1 4 atoms liydrajj^en . 








8} ciibtc inchn of curbon wcip^h 
7 cubic inches of hydrogeo woigt 

So ikst in tills analyuB there in a deficiency of tliree per c«nt- 
rliieh 1 am di!ipo<ip<l to ascribe to iLo preitencc of azote aa ■ 
(MMitueiit of naplitka in tliiit projtortion.' 

JL Sta-war, or mattka^ or mtHeral Ifillow, is a solid substance i>»-«i. 
tbuml on the Baiknl lukc in Sibcriit. It i<< white, melts when 
iNtUrd, uid on cooling assumes the consistence of white cerate. 
Il^notres readily in alcohol, and in other respects appean to 

CM the clkaincters of a solid volalili- oil. Itx properties, 
vcr, hare been but inipcTft-<-tly exiuninod. Klaproth found 
Att a naiilar tuibstunci! wiu obtiiinod by distilling a species 
ttnodeoal, colled ttirth coal by the Gcrmans.-j- 

Thr sabstanoc described by Kirwnii under the name of mine- J^"""' "^ 
nlUithir, and said to have been found on tlie coast of Finland, 
IbI^ Swedish lakes i>nd in a fountain near Strasburgh, seemH 
to ^proech vtry nearly to sen-wax. Its specific gravity ia 
^TO. It is white, brittle, st<iin>! paper like oil, melts when 
wltd, Mid burns with a bUie flame and mudi smoke ; dissolvM 
"^rfeetly in hot alcoh<d, but readily in olive oil4 Specimens 
<f Aiiaiibstaiice have been found in different parts of tlie High- 
■iodl of Scotland. lliere is a specimen in the Ilunterian 
UMemn, which was found near Inverary. I have another spe- 
ii««i from a moss in the neighbourhood of Oban. The hat- 
twttme of Conybearc, found in Wales, i» merely a variety of 
■oiflptal tallow. 

3. Proper Bitumens, 

Hie true bituminous substances may be distinguished by tlic chwHun. 
bUsviog properties : 

L They are either solid or of the consistence of tar. 

9L Their colour is usually brown or black. 

& They have a peculiar smell, or at least acquire it when 
'nbbed. 'HiissmelliNknownby thenameof theAi'/KMirNoiuodour. 


• AMub at PtiUiMopliy, xr. 307. f Bcitrage, UL Sii. 

t Kirwao't Mioenlogy, U. 47. 
U. 3 B 





4. They become oloctric by Action, Uiougb iiol insulate*!." 

5. "Hiey melt when heated, atid bum witli a strong Hiael!, 
a bright flatnc, and inueh ninok^. 

6. They are insuhiblctn water and alcohol, but dissolve raott 
vommonly in ether, and in the fbted and volatile oils. ■ 

7. They do not dissolve in alkaline leys, nor form wop. 

8. Acids have little action on them: the sulphuric scarcely 
any : the nitric, by long and rt-jx'iili-d diirt-Htion, dLssoIrea tbeni, 
and converts them into a yellow sutwtauce, soluble both in n-aler 
lind alcohol, and similar to the product formed by the action ef 
nitric acid on resin s-f 

The bitumens at ])rc8cut known may be n>duce(l to three; 
namely, aspbaltum, minemi itir, and mintral caoutcMmc, Bitu- 
men has been found also united to a re^inoiw compound, in a 
curious substance first accurately examined by Mr. Ilatckett, 
to which he lias given the name of rrtiftatphaltum. United la 
charcoal in various jiropoTtions, it constitutes die numcrovi 
%-aTietieH nf pit-rimJ, so much employed tn this country as fael 

1 . Asphaltutii. This sul»»tanee oc«ir« in gn^jit abundant 
in different countries, especially in the islun<l of Trinidad, oa 
the shores of the Dead Sea, and in Albania, where it is found in 
vast strata. It is supposed that it was first liquid, iind thit it 
acquired solidity by exposure to tlie air. 

Its colour is black, wieli a shade of brown, red, or gny. Id 
specific gravity varies. That of Albania, as ascertained bv 
Klaprotli, was 1-205 ;f but it wan somewhat contaminated u'lth 
earth. Kirwan, in purer specinunis, found the Specific giarity 
to vary from 1*07 to l't(id.§ Klnproth has published on 
analysis of the asplialtum of Albania. 

He found it insoluble both in acids and alkalies, as alsob 
Water and alcohol ; hut soluble in oils, petroleum, and sulphinic 
oilier. Five piirt-f of rectified petroleum dissolved 1 part of 
asplialtum, without tlie assistance of heat, and formed a bhdti^ 
brown solution, which by gentle evaporation left the asphaltuB 
in the state of a black-brown shining varnish. The solution b 
etlier wm of a pale brown red colour ; and wiien evaporattd, 
the aspholtinn remained in llie Htateof a semi-fluid stitwtuioe of 
a reddish colour, still inMhible in alcohol. 

A hundred grains of tilts asphaltum being di«ttlle<) in a retort. 
by a heat gradually tsiscd to redness, peldcd the foUovinf 
products : 

Bally. I lUlchm. | Beiunge, iii. 313, ^ Mineralogr, ii. W. 



36 cubic inches (German) of heavy inflammable air 16 
A light hrown fluid oil ... . 32 

V'xtcr Nli^htly tuijit«<l vriUi atamonia . . 6 

Clun-ual 30 

Ashes 16 


oAe^ constated cliieHy of ulica and alumina, witii aoma 
iroti, litn<', iinil iiuiii^ic«c.* 

The Mphuitiini f»iiii<I in Alhiiiiia h »tipjKncA to have con- 

ibtuU'd till' chivf in[rT«(licnt of the (mek _fire. Tliv E|^ptian8 

aid to have employed tliis bitumen in cmbulming. It wns 

'Cilletl mumia miaera/in.f The ancients inform us that it was 

Med imtcad of mortar in building the walLi of Babylon. 

2. Aaphaltum b seldom abflolutcly pure; for when alcohol 
ild%Mt«d on it,.tlie colour of tlie litjuid bct;onK"< yellow, and 
bj' gentle evaporatioti a |M>rtiou of |ietrolcum is Fieparuti-d.j; 
Slinerat far soems to be nothing else than asphallum contain- uinmita. 

»tiig a atill greater proportion of petroleum. When alcohol is 
Sweated on it« a considerable qiuintity of that oil is taken up ; 
but there remains a black fluid substance like melted pitch, not 
acted upon by alcohol, and wliich tliercfore ap])ear8 to possess 
the propcTticw of aaithaltum, with the exception of not being 
solid.! ^y cxpo«»rv to the iiir, it is said to assume gradually 
the state of asplialtum. 

9. Mineral caoutchouc is a singular substance, hitherto found Mmmi 
only in Derbyshire. It is soft and very cListic, not unlike 
emmoN aumtchotic, or Indian rtMer, and, like that substance, 
{t a»y be employed to eflace |)encii marks ftom paper ; but it 
khIs the paper a Ultlc. )ts colour is djirk brown, sometimes 
witli a sliade of green, at otluT times of red. The finil account 
of it wu published by Dr. Lister in tlic PhQosophical Transao- 
lioiu for 1679.11 It occurred in an old forsaken mine in Uer> 
hyshire. He catU it a Kubterraneoua fiiogus, and is uncertain 


■ KIapr>«h'i> Bcitragr, iii. 310. f Watioa'* Chom. Euayi, ill. 4. 

I Uatcbott'* OlHcnaiioni on the Chnngc of Rome of the PrindplM of 
Vigatatiln iaio lUmmcn. Phil. Tnuu. IbOI. 

I Omul II 1 1 anJ mincrnlc^tli hnvc uniidd mineral tiir lo |icIroleuD al B 
nrloty. If it be inic that pure petroleum U iniolulile in slcohol. that 
■mogcneol JK ri^-lit ) bul I minpccl n iiiitialic. I had no opporiunity of 
trjipg mpA rt i i J but ilie piuwi petroleum I Untt been flblo to procure rMdily 
field* to alcohol, udIcm it hoj been left ex(x»ctl to lh« air, 
I Vol. nii.p.et79; 

Wfl NKUTRAi. cojrrorsBs. 

«r InilT 

***■'"■ wliether it belongs to tli« vegetable or mineral kingHoms; Imt 
ratlier inclitiH to the former opinion, »ti<l liinbt tlint it may have 
growji out of llie oU bircli projis used in tlic mini", It was first 
un-uratcly described by Mr. Ilatclictt. Delamctkerie first 
exnmined its properties; ukI un analyftis of it lias been puU I 
lis^iieil by Mr. Klaprolli. 

Acconiing lo KUpr«tb, it rt-sists the action of nlmo«t allj 
<|uid meiistnui ; noilhcr iilvoliol, alkalies, nor nitric acid, afTrct- j 
Iiig it Even oils were not found by hira to dissolve it, thoii^ 
DelBmetkoric assures us that he obtai»e<l « suliitiou of it in 
olive oil.* Petroleum succeeded best witli Klaproth, assuming 
a bright yellow colour, while the caoutchouc wa» ronderwl 
tmnspaiont.f When heated it melts, takes fire, and bums 
wiih a bright flame »iid a bituminoiti smell. 'Hie melted mass 
still continues aithesive, and may be drawn out into thretds. _ 
It is now Bohible in oih.:^ I 

One huiiilrei) grains of this sulMtancc being diMilled In a 
retort gradually laised to a red heat, yielded tlie fulloM-iag 
products : 


38cubic Inches (German) of heavy inRammablo air J .j, _. 

4 inches (German) of carbonic acid gas 
A brown thin bituminous oil . 
Water »ligliUy acidulous .... 




The aslies consisted of lime and silica, with some iron, sul- 
phate of lime, and alumina.} 

Mr. Halehett suppones the ela.«l>riiy of tins substanoe to bt 
oning to a qunnlity of air confined between ite poreSL 
JUS^'''^" 4. The rttinasfAallum of Mr. Ilatdiett is a substance hither- 
to found only accompanWiig Itoity mat, in Devoni>liire.5 !■ 
was finst mentioned by I>r. Millei; but we are indebted to 
Mr. Hatchett for every thing knowii respecting its cl)emi<a' 

'I'his substance has a jiale brown ochre yellow colour. Il !> 
very brittle, and breaks with a vitreous fracture. Its specific 

• Joitf. de rhfi. xxxL 312. f iteitniKP, in. 100. 

) Klnproth, ihid. j Ibid. p. 110. 

^ Vaiaa the tobitlniice fiHinil iinr Hutti-, ui<l sDoIyRtl b}' Burlioli, t« 
umilar. Sc« itchweigger** Jouraal. i SW. 



|.gnvily is 1-135. When held in tlio liaiwl for some time, it —'*■ '""• 
^tnita a sli)^btly resttious smtW. ^^^lL>n liiittvil it inolu, smokes, 
burns with a bright fliiin<-, bikI emits a fntf^niMt (xlouTt at last 
tiiiiiu-tl willi .1 bitumiitous §ineil. Hie aii-lto<I nuuw, when cold, 
pfe UUu'k und tirittli', and lire.'dLt willi a glassy fradun-. 

M'litcr doc* not act u[wn it; bnt it is jMirtially dissolved by 
Filcofaol, potash, and nitric acid; (he dissolved jxHliuii baving 
, the properties of a rcain ; the undissolved of ssphaltum. Mr. 
' llalcliett analyzed it, and found it composed of * 

53 reain, 
41 asphaltum, 


&. Pit-co«], one of the tnost useful of all the mineral produo* nL«i. 
lius l>c«>n divided by mineialogists into various species, 
Wcordin^ (o its external appcaraiivc^ auA tlii> nature uf the 
itnia in which it is foiuid ; but in a chemical point of view, il8 
wwt imjwrtunt varieties may be distinguislied into two s«ts : 
I. Tho«c tliat still contaiu Heveral iVf/tttMn i»incifJt*, strictly 
Kt called, and thus give evident inarlu of ilivir ori^n. I'o this 
kead belong mmt of the riLtielics of coal amin^d by Werner, 
wader ibe head of Itrmtn coai. ^Ir. Ilatehctt has sbowii, tiuit 
in aome of the substances belonging to Ibb claaa there is to b« 
fMUd B poTtioQ of etgriablr. txtrtict; in otbor<t. a« in Dovey 
edtJ, a portiou of rttin; Ix-Midi-n tin; cbureoiil and bitumen, 
which eonstilute the greatest part of its con«ti(ucnta. From 
mother species of brown cuoil Khiproth obtained by mnuis of 
■loefaolf a brown red tincture, which left behind it on cvaponw 
liun, a reddi»li bitUT txiraci, partially soluble in water.f 3. 
Tlkonc kinds of coal (liat contain no traceit of uiuiltered tvgw- 
tMe pritiriptea, but are comjioiied of variouf pn>portt»ns of 
bitumen and cluircoal, contannnatetl like lliii former witti eartiiy 
nattt«-r. 'I'u this head belong (be viiric(ici« of coul arrung^.'d by 
Werner under tlie name of l/iark coal, which abound so miicli 
in nritain. 

Tbe different species of black coal which occur in Great ^uta. 
Bribiin and Ireland, so far a.4 I liave liad an opportunity of 
emtnining tliem, are five. Tbey have been distinguished by 
the followiii<r luimeft : 

■ llalchcti, on ih< riinngc of Mine of ibc Piinciplca of Vf^sUct to 
BittHdM. PhiL Tnns. IMH. J 






I. Kilkenny cool ~ 

3. Caking c«al, 
a. Splint coal, 

4. Cherry coal, 

5. Caiincl cum). 

1. Kilkenny coal, so called bcraiisc fuiuitl at Kilkenny in Irc- 
liind, belongs to tlte Glance eottl «f Werner. It has a seidi- 
metallic lustie; <Ioes not soil the fini;ers. It* tipecific gra^ty 
is l-4'')54. It cuDsttmes witliout flame, and, n-hen completely 
burnt, leaves 4 per cent, of light brown ashes, coniusting chiefly 
of Hiiicii and iron. 

2. Caking coal, is so called because when heated it fuses into 
a kind of bituminous matter, in ounse<|uence of whieh all the 
pieces of coal, however small, colicrc together into a cake. It 
occim abundantly in ihe iiei^]ibonrlii>u<l of Newcastle and 
Sunderland, in Fife, ut Baniiockbum, and in tlie Glasgow coal 

Its colour iit velvet blacJi. — Lustre shining, resinous. — Prin- 
cipal fracture straight slaty ; cross fracture partly small grained 
uneven, when the liiNtre in only glistening; partly small coii- 
cboidal when the lustre is shining. — Soft tuid rer)' easily fran- 
gible. ^Fragments ctihicnl — brittle — soik th^^ fingers. Specific 
gravity r'26». It catches fire very easily, and burns with a 
lively yellow flame ; but in canse(|uence of its caking jtroperiy, 
it must be frequently stirred to admit the acecM of air, other- 
wise it b extiugiiislied. 

3. Tlie splint coal occurs iibuiidantly in tlie neighbourhood 
of Glasgow, constituting the fifth of the six Glasgow beds. It 
is a well chamcleriscd species, and constitutes the most viduable 
of the Glasgow coals, selling at a higher price than any of tlic 
other )i])ecies. It is the only coal in llie neighbourhood of 
Glasgow used for the manuliu.'turc of coke. 

Colour bhick, with n shade of brown — lustre bctM-cen glim- 
mering and gUstening; resinous — principal fracture irapcrfcet 
curve slaty. Cross fracture line grained uneven and splintery 
— not harder than caking or cherry coal, but much more diffi- 
cultly fiimgiblc — fragments wedge shaped — specific gravity 
1-290. It requires a much higher temperature to kindle it than 
either caking or cherry coal. It burns wiili flame, and is much 
more <lurable than cherry coal. 

4. Cherry coal abounds in the neigh ho nrhood of Ghui^ow, 
and in Staffordshire near Hinninghnm. 

Colour velvet black, with a slight shade of grey ; lustre iii 




MorEK Din'MCNS. 


l-Wamo pl»cc« gplcndfint, iii others, shiDing. Hliere the Instrc 
■hmiti^, the coal has exaeliy tlic appearance of caking ooal; 
but it bt easily (liMtinfrimlirrf from that HpmoH Iiy not melting 
or soflenini; when hciitetl — kind of lustre n-sinoiL's. — -Principal 
fracture «tniiglit slaty : the different layers differ iji their lustre, 
•one i>eitig splendent, others shining. When the lustre i« 
q>lendcnt, tbc surface is specular; but when only shining, it 
it merely even — cross fracture flat concboidal, and spei-ular 
splendent — equally hard with caking coal, and very easily 
frangible — fnigmi'niH rectangular — very brittle — specific gru- 
vily 1 -265. \Vhen exp<'«cd ro heal, it readily catchex fire, and 
burns witli n clear yellow ibune, and giving out a great deal of 



5. Cannel coal in m called, bi-otuiw Ji burns like a candle cuuhi 
when lighted, aiul i» often employed us a sulwtitute for candles. 
It aitound* at Wigiui, is found near Coventry, in Aymhin-, and 
in Lanai-kshire. 

Colour dark grej-isli black; sometimes brownish black — 
Inttre glistening, resinous — admits of a good poiish, and is 
often cut into ornaments like jet. Fnu-turc l;irge iuid flat con- 
choiduL In the great it is frequently gtaty— frjigments »ome- 
limcs cubic, wmn'tinies wedge shiiped, sonK'tiinesiunorphuua. — 
About UM hard ns raking coal— brittle — (Iocs not Soil tlie fin- 
pT9 — much more difficultly frangible llian caking coal or clierry 
coal; but more easily titan >plint coal. — Specific gravity 1-272. 

'Hie following tiibli- exhihiis the quiuility of eartliy matter xitm. 
unully found in 100 parte of each of titcsc coals: 

I. Kilkenny coal . ■ 4 percent. 

3. Caking cod . . 1-5 
a. Splint coal . . 9-5 

4. Cherr)- coal . . 10 

5. Cannel coal . . 11 
le following table exhibits the qiinntity of coke whidi 1000 • 

parta of cacfa of these tpeeies of coal forms. 


VCrlmM or 






Wriihi pf 





Kilkenny coal 
C'ukiii); coal 
Splint coal 
Cherry a»al 
Caniiel coal 




647 3 








I determined tbe consdtaento of theae diffierent qwdes bj 
headng tfaem in contact with peroxide 4^ coffer. The fbllow- 
ing tables exhibit the result ol these ezperimentB.* 

1. QMatitttaita by weight. 







Kilkenny coal 






Caking coal 






&)lint coal 
Cherry coal 











Cannel rani 






S. CcmstituaiU in atom*. 






■ imtiirf 

Kilkenny coal 




Caking coal 






Splint coal 
Cnerry coal 











Cnnnel coal 





* Annati of PhiloBopb]', xiv. 61- 




PART in. 


secondary compounds, is meant tbe compounds formed iinnt. 

tkc union of the primary compounds willi each other. Now 

ihe nvutnti primary umipuiintU vntcr into but few com- 
UmtioDB, it in oliviitLiH tliat the secondary i'»m]ioun<la must 
teamt cliiefly of combinations of the acids witii tbo buseti. 
Sudi oompoundH arc called «;//». They constitutv u very 
nttaifn>n)> jukI important HCt uf bwiit-s, wLicb it b of great cun- 
■equence to undcretimd wcLL 

'I'lie word suit wan originally confined tu common aali : u^h. >hw. 
■ubstancc wLich lus been known aiid ii] common uite from the 
rFmot«-»t a^s. It wns afterwards generalized by cliemists, and 
cmpluyvd by tlieni In a very cxU-nNivt: luid not very definite 
wnse. Ever)- body which i» Mipid, «iMly melted, soluble in 
vntcr, atut not combimtililc, has been mlled a mlt. 

Salts were n>n<.idrrcd by ibc older cbemista as a class of 
bodies intermediate between earths and wiU-r. Many diajnitei 
atose about what bodies ought to be comprehended under this 
clan, and what ought to be excKuli^d from it. Acids and ulka- 
Um v«Tt allowed by all to be aults ; but tlie difficulty was to 
dclvrmine concerning ourtlut and metuU; for M'veral of tlie 
tATtbs pusM-H all tJio properties which have been Mcribed to 
salts, and the metals are capable of-enlering into combinations 
trhtch poasem saline properties. 

In proce«« of time, however, the term tail was restricted to 
throe duscM of bodies ; namely, adds, alkalien, oxtA tbe co>n~ 
fotrnds which aiiids form with iilkulieM, earths, m»1 mctidlic 
oxide*. Tbe first tn'o of these ctuMee were cidled timple naUn ; 
the salts belonging to the third clasa were culled com/iound or 
txutral. Tim laxt appellation originated from an opinion long 
cnt«Ttained by cbemistK, that acids and alkalies, of which they 
lire composed, were of a contnu^- nature, and tJiat they coiui- 
tentcted one another; so (hat the r^^ultiiig compouiiiU ptxt- 
•esscvl neither the properties of acids nor of alkidics, but pro- 
perties intermediate between llie two. 

C'hvmisb have lately rcslrictetl i\u.: lerai tall still more, by 
tacitly exoludiiig acids and alkalies from tlie class of sadts alto- 




*^"'- gether. At present, then, it denotes only the compounds 
formeil by the combiiialion of aci<U witli alkalies, cartliB, luiii 
metallic oxid«8.* 

At) litfTe tav niim cltusM of oxiAn, it ta obvious that there 
must he as many classes of tuilte. 1 sliaU ffve an accouot of 
these different classes in successioD. 


JJ^I™*'*' This class of salts has been lonj^st htiuwn and most com- 
pletely iiive-ttigali'il. Of course the salte belonging to it are by 
&r the most numerous. According to the notnenchiture intro- 
duced by Murvcau, which is still followed in chemistry, the 
genera of these salts are named from tlicir acid. Thus if thv 
seid be futphnric tlie salt U called a gulphate, if the acid be the 
nitric ilie salt is called a nitrtttt., and so on. The species are 
dixiiiifruiHlied from each other by adding tlie ruune of (he Imw. 
Thus sulphide of soda is a salt composed of sulphuric and aiu} 
toda; oxaialt of liiiM- U a sail composed of oro/i*? acid and //aw. 
"When the salt is a compound of one atom of aci<I with one 
atom of base, it is distinguished simply by the name. If the 
salt contains two alirmn of acid united to one atom of basr, the 
Latin numeral udverb &u> or hi is prefixed. Thus biavtphttit 
of potash U a mit composed of two atoniK sulphuric acid and one 
atom p»t;ish. Were there 3, 4, &e, atoms acid, tlie numeni 
adverlks ter, quater, &c. would be preiixed. Thus quau^roxalute 
of potash means a compound of 4 atoms oxalic acid and I atom 
potash. NMien there exists an atom and a half of acid united 
to one atom of base, the I.ntin term setgui (one and a half) U 
preRxeil. Thus sm^uicurlxmate of soda is a compound of 1| 
atom carbonic acid witJi 1 atom soda. 

When two atoms of Inisc are combined witli one atom of 
add this ts denoted (>y prefixing the Greek iiamend adverb dit. 
Thus diphosphate of potash means a compound of two aunH 
potash with om- atom phosphoric acid. Tlic prefixes tris 
tetnikis, &c. indicate tliree, four, &c. atoms of base with one 
atom of acid. 

After considering tlic subject wiili considerable attention, I 

* Thr trrmi tail and nfulr\it t'ltt nrc often conroundcd. In this worfc tl 
c|»UicC nni/ivl ii confined (O salts liaiinft no uc«*s of Kid or tiwe. 


link the moiJc of arranging tin? wilW according to the bases ta fl^f* 

tcvnded widi sucli ailrantngos us to iruliicc m« to ttAoyii it in tliis 

'Work. Weitliuuld t hi.- rcfore divide tlusclitits into 4'iMecltons, 
allowuig a HCcUoii for tbo nalot formed by tlic combinuliiin of 
mA ntifiable base with the diflVrejit acids. I)ut therv arc 

IMrmal of the acitl Wi^-x wliicti combine willi aei<U and fonn 
nits. 'lilts, tugerticr witb the double m\t», will oblige us to 
diride the c/a«s itiio no fewer than 52 scclioiis. 

I 1. n»e salts of ammonia, witJi a very few exceptions, ate all 

Mdabte in water. 
S. When potasb or quicklime is mixed with an tunmoiiiucul au™c«i», 
a Kmell of ammonia is emitted. 

If to an umnioiiiacal salt dissolved in wiiti^r a little ttult 
tinitatning magnesia be ailded, ajid afterwards wine p]ioMphat« 
nf todu dropped in, a eopiouw wbilt.' precipittitc falls. 

i. When au animoiiiaud mlU U vxpcised to heat it is oom- 
plrtely clin)]>ated iu rapoura; except when the acid hit^ a fixed 
artat, or phosphorus, or boron for its base, in which lust ca»e 
tliF acid ulune remains behind. 

5. 'Hie ommontiical salt-* are not prccipilaied by iiifuMon of 
iiut>galU or prussiatc of puUiAh, 

: When a tiolution of plutinum is dropped into a salt of 
min, a yellow coloured precipitate &Uit iu very Bmall 
This genus of salts has been very fully investigated. Th« 
lUowing are the dilTiTt'iit >pccieH : 

Sp. 1. Sulpltatr u/ arnmtrnia. 'Ilii* salt was discovered by f;;^'^^'' 

lauber, an<l called by him Hfcrrt ml ammoniac. It was also 

led vitriolated ammottiac. It may be prepared by satiinktilig 

lOnia with xulplmric acid, or by decomposing sal ammoniac 

iD«flU)S of sulphuric acid. It exists native, and U then dis- 

blicd by the name of MiKuraj/win. There are two sub- 

of this salt, differing from eiich other in tlie water of 


(I.) Pnto'ht/drated auip/iMe. I obtained it crystallized in 

[rtgiilur rcdanguhir plates, and conwder tlie form of the crystal 

\>f a four-«id«d prism witb square bases. It is transparent 

id colouriets. Its specific gravity is '2. Ithiis ai^lior]) bitter 

It is aoluhle in twice its own weight of waU>T at thv 

iperature of 60% and in iu own weight of boiling water. 

'atcr of lli« temperature of 144° disHolvM 0'76 of its weight 






of this «Ut.* WliiMi cxpmrd to the uir, it Hlawly atUieti 
moistun.'. Iixtoed from the experimenta of Hiitchott it is 
obvious that at a red heat tlie suit 1.1 eoinpletely decomposed. 
I found UkU variety composed of 

1 atom fltilphuric acid . . S 
1 atom iimmoiiia . . . 2-125 
I utoin u-utoi . . . l'l'25 

(3.) t)eutt*'ht/dra/fd stiiphate. From the aiialysvs of Kini'an 
aiid Itt-rzcUii.-' it a{<])c.-in that thiit variety is the modt comrooB 
State of tliR salt, in wliich it i^ obtaiued when dilute Bulphuric 
acid is satunitcd n-ilh carbonate of ammonia, aiul tlie lii|ui<l aftui 
being §ul}iciently concentrated is set aside to crystallize. 1'be 
crystals seem to have exactly the same shape as those of »ul< 
phate of potash. In oilier n-si>ectii, it* properties agree witU 
those of the preceding variety. I have never, however dctrr- 
uinecl its specific gravity. From the analysis of Berzetiua, iM 
oonstitueoti) arc 

1 atom sulphuric acid . . 6 

1 atom ammonia . . . 2-125 

2 atoms water . . . 3'26 


By drjing it on the sand bath it loses ono atom of water, a 
is converted into llie firitt variety. 

2. iimdphnlf- nf ammonia. Tliis salt is easily formed hy 
dissolving the preceding in water aci<lulateil with a quantity of 
Bolphuric acid equal to that which the salt cuutains, and thea 
eraporatiiig tlie solution to the proper con.sislency. Ilia 
bisulphate vrystalliies in thin rliumltoidul plates. It has anadiJ 
and bitter taste. W'licu exposed to the air it speedily attiacO 
moisture mid deliquesces. It is sohible in its own weight a/ 
cold water. It is a compound of two atoms sulphuric aeidand 
one atom ammonia, but I have not determined the water of 
crystallization wliicli it contjiinn. 

■i. Sui/t/iitc of ammonia. This salt b easily obtaiued bf 
passing a current of sulphuruits acid tlirough u solution of 
ammonia iii a Wootfe'a bottle. The silt may be obtained ery»- 

^ • WmuiJ, p. aoa. 


in 9ix-jtMl«d {triHRiN. If) Uukte in coolmfi;, sharp, »n<l 
['•uIpliiircKtw. When lmt«<l il d^cwiiiUites, nn<l bec«ine« white , 
witltodt mpUin|r, giviitjr out a liltiv ammoiim im<l Ix^hifr coii- 
TiTtfd into n t>t>tiil[Oiiu-. It (lii«^>lvi>s iii iU own woight of 
water. It hits not 1>ppn atialy7.e(l, hut U probably a ctHnpound of 
1 Atom «itlp)iurniiA avid . . 4 
1 atom ammonia . . . 2025 
J atom water . . . 0-5625 


my 1 

4. Uppnmtphiff n/amnwtiin. According to Mr. Heradiell, Jh^^ 
tliF only ponott who has Ititlicrtn I'xamined tliin sidt, it is 
tlv»ys a compound of 3 atoms arid witli 1 atom Im^c ; so tliut 
h la a bihvpnsutphile. It dnex not roudily cry»tiilli/«< ; hut 
vWn much (■iinccnlrnlcd, cooU iitlo a confused pappy mass of 
' mlnntc spicals. Its tostr U tntingly pungent, Hucceeded 
dts^ufiling bitterneM. Vhcn licatod, it bunts with a 
; flame, and evaporates entirely.* 
5. Hi/fitmulpkate of ammonia. 'Hiia suit was formed by M. ^>J*|^ 
H«e»ntff Hiuidnirgh, by docnmpiwing; hyposulpWe of luiryt«'s 
tiy Bwans of Kulpluitf of ammonia. It in ^u !«oliihlc in n-ater 
'^l br was unable to obtain it in rc^dHr crystnltt. By spon- 
litifoiw evaporation some needle-diapcd cryslids appeared. At 
4* u-mjMTatUM! of 60* it di«iolves in 0'7» of its weight of 
«tef. During ihe Mhilion the tcini>eraiure fiinkfi conHi^k'nibly. 
It i* insoluble in absolute alcohol. Tho toMe \^ cooling, and 
"WiiUr to that of Glauber salt. When heiited, il gives off 
•Uer withntir mcliing, ihen suIphuroHs acid is expelled, iind 
Wft'^idue (which now melts) is *ulplmti' of nmrnonla. Its 
Mitdtaents, as determitied by the analysis of KI. IIeer«n, are 
I atom acid ... 1} 

1 atom ammonia . . 2*125 

2 atonn water . . 2-25 


6. titrate nf mmutinia. Thi« salt has been long known : it Kmu. 
WW formerly distinguisJied by the names t>i tiitntm ttmirofatile 
nd nitrvm fiamman*. Ilerthollet examined it in tlie course of 
Ua eXi>erimciitM on the component parts of nitric ikcid: and 
8fr H. I>i\-y liat midcd i'oii*i<lerably to our knowledge of iu ' 
eompoeition and decomposilioii.f It may be prepared hy dis- 

■ Bdiabwgli l*lril Jour. i. 19- f ^tf* itcMArdic*, |>. 7 1 



^*""'- solving cnrboimtc «f nmmonia in diluUid nitxic acid, and cva- 
puniting the solution till die salt crystallisKs. 

The appearance of this salt varices very mucli, accoixling to 
the temperature at which it« Molution is cvitponUod. In a 
moderate heat, 70" or 100' for iti^Uince, and by slow cooltii^, 
it i.H obtained in six-sidi-d prisms, terminated by long six-&ided 
jiyrninidi!. When the solution ia evaporated at the tempera- 
ture of '^12*, the i:Ty§tals are cliaunelled and have a fibroai 
texture, or they are formed of loujf ^oft olii-itic threads. When 
dried in n Lcat of about 300°, it oasumeti the form of a white 
compact nia»s. These ditTerences arc owing to different pro- . 
portions of water of crystal 11 zation which the salt contains. ' 

Nitrate of ammonia has a very acrid, bitter, diaa^eesble 
taste. Its specific j^ravity is 1-6785.* At die temperature of 
60" this iialt Lt .'ioluble in two purtt of wnter : it dL-u>4>lv«-« in 
half iU weight of boiling water.f It mnsl be observed* how- 
ever, that its volubility varies nnth die proportion of water < 
crystal ligation which it contains. When exposed to the 
nitrate of ammonia soon attraeta mointure and deliquescetc 

Wh«>n lhi!4 Halt, in the sLite of fibroun or ])riMnatic cry»b 
is heated, it becomes fluid at a temperature behiw 300** ; b^' 
tween iiGO" and 400° it boils without decom[>osiiion ; bm whecm 
lieiLted to 4.'>0'', or somewhat higher, it i» gr.iiliuilly dtKoinpoMcl 
without losing iti! watvr of crystilliicatton. ComjMct nitrate^ 
on the other Land, uiidergue* little or no chaiigv till it it# 
exposed to a temperature higher thiui '260°. Between 376^ 
tiid 300° it sublimes slowly widiout decomposition, and with- 
out becoming fluid. .\t 320** it melts, and at the same tioac i^^ 
partly decomposed, pardy sublimed.^ 

When Uiis Milt is decoin]>oxed in a temperature not excewl— 
ing 500^, it is wholly convcrt4>tl into protoxide of axote am^^ 
water. From the experiment* of Davy, it appears that tbes^^ 
products are nearly in tlie proportion of four parts of gas tc=^ 
three parb* of water.§ It is easy to sec that (abstructiug the 
water of crystallization) it must be decomposed into 
WaUr . . . a'375 or SO 

Protoxide of luote . . Ii-5 44 

Hsv thia is nearly iii tho proportion of H parts of. wal«r to 4^ 
porta of protoxide of azote. M'lien it i-« exposed to a heaC 
above 600', this dalt explodes, and is totally decomposed, beit 

• HiuBenfrsti, Ann. de Chtm. xxvUi. IS. 
•f VooTctoy, iiL 19^, Bng. Trans. 
i IXiv}. |>. 8j. § Ibid- |i. ia». 

U- — — 




conr«rtcd into nitroua add, nilrouit pi8, wat«r, and azotic gii». ^V*]* 

This pbenoinenoii, oIisci-vkI long iifto, induced the older clic- . 

mists to give Uie will the numo of nttnim Jftimmmi*. The 
nature of thv decomposition was first a§cer tain cd by BerthoUet, 
uid more lately it ha^ lieeu examined by Davy, Iti eonstitu- 
rnts, as determined by Iterxeltus,* afiervrarda confirmeil byun 
■nljrBM of my own,t are at ToUows : 

1 atom nitric nci<l , . 6*75 

I atom iimmoniii . . 2-125 

I ntom wat«r . . . 1-1S6 

Sr H. Davy analyzed tlie salt in cryittalti, io a fibrous, and in 
■ pniinalio »tate; Um results were as follows: 

Jtc'ti. AiniiK»U. WoUr, 

Crysted . . 69-3 + 18-4 + 12-1 

Fibrous . . 72-5 + 19-3 + 8-2 
Compact . 74-5 + Ift-S + 6-7 

IW proportion of ammiintu w too small in all of these ana- 
IflK But if we make allowance for tJiis defect, the comptnitivn 
in uoDis will be nearly as follows : 

AoJ. Sue. Wittr. 

Crystals . . 1 atom + I atom + I atom 
Fibrous . . I -t- 1 + 0-67 or | 

Corapct . . 1 +1 + 0-45 or j 

7. Hypom'trUe iif ammonia. This salt is obtained when iinnniuiw. 
dBponitrite of lead and sulphate of ammonia are dissolved in 
'^ter and mixf^l in die atomic proportions. The solution 
H'ben eviiponited ^ivi>« an irregularly crystallized ma»», con- 
taining one atom of water. When heated to 122' it gives 
Out azotic gM (according to Beraetiui,),) and is converted into 
ditmlc of ammonia. 

8. Carbonate <^{aniittmia. TlnA mlt bait been long known, cubaiat*. 
It is ofien obtained by diMtillinji; animal )iul)stanceH : but fur 
dientical purposes it Si best to extract it from <tul ammoniac by 
tn«ans of elialk. Two parts of chalk and 1 part of sal ammoniac, 
botli as dry as poMibIc, are mixed together and put into on 
earthen retort. On the ap|>[ication of a sufficient beat, carbo* 
iiate of ammonia sublimes, and ik obtained in the sLite of a 
wliit« cryntiillixed insttA. 'I'he crystnls tire so Mnall and so iirc- 

* Ann. de Chiiti. Uh. ISS. 
i Oilwrt'a Aaittlen, si £00. 

f Firtt Principles, i. tW. 



oxvoetr ACID salts. 



gular, that it is difficult to anoertitin their form. According 
Bei^rmaii. tliey may I>e oUtniiied iiirlicmibicoctu)ie<]rDti!«,liaviii^, 
fiar ttii^ taiMt part, tbcir two opposite apexes truncatod.* Tto 
liist« ]ui<l stnell of UiU salt, though much weaker, are the Ranifl 
with those of pure ammotiia. Like nil the alkaline carbonatM, 
It converts vegetable blues to green, precUcly an pure a! 
do. lu Hpceific gtsvity is 0-!)66.f It is nolublc in rather 
than twice its weight of cold water. Hot water dissolves ill 
own weight of it. Boiling ivater cannot be employed, beniiM 
at tliat heat tlie carbonau- ix volatilized. A SAturated nqueoia 
solution boils at 179° or ldO°. Its constittionts, when in crj'B. 
I«l», are 

1 atom carbonic acid . . 2-73 
I atom ammonia . . , S-lSiS 
1 atomu-aier . . . M25 


0, SfaqtiicnrioiMtf. i^f ammonia. This is the name which 
on^t to he applio^t to the carbonate of ammonia of the sliops. 
It it in hiir<l whit«> cakes, about two inches tliick, oiid is evi- 
dently obtained by sublimation. At leart I have never meft 
with any of these caltes that did not contain an exci's? of car- 
bonic arid. !t3 constituents, from a careful analysis made in. 
my laboratory, were found to be 

l|«lomcK-id . . . 4-125 
1 atom ammonia . . 2*125 

1 atom water . . . 1*I2£ 

The carbonate may he formed by mixing 

1 volume carbonic acid g:is, 

2 volumes atnmonincat gas, 

1 volume vapour of water. 
The sesqidcarbonate by mixing 

1^ volume carbonic acid gag, 

2 vobtTntw nmmoniticul giL«, 
1 volume vajMnir of water, 

10. Bicarhonate of tmttiKmia. This salt may be obtained by 
exposing ihe common carbonate of ammonia in powiler to the 
air, or hy causing a current of carbonic iicid gas to yaxt tlirouf:^ 
a solution of it in water. It erystoUixcs in six-aded prisms, 

* Ber^M), i, SI. f BatMnfratt, Aan.dc Chkn. xx*iii. 



luuully small, Itts no smell, and tcsa taste tlian the carboiutto. 
ll distoKoa in 8 limes its weight of cold water. Hcrtliollet has 
shoirii thai when the sidiKiuii U t-lighily heated the «dl htsesa 
portion of its add. It wusaiudyz^^d hySchrader,' Borthollet,f 
bimI Pbiltiits} from tlic result of wtio!i« analyses U is obvious 
Its i-oiistltiicnts arc 

3 atotnti carbonic acid . . 5-6 
I atom ammonia . . . 2-135 
3 atoma water . . . 2-35 


U. Phonphate (^ ammonia. This salt exists in urine, a»d 
v«lH to have been fir^t accurately di^tittguiiihed by Koucllc. 
It vaa afterwardi examined by Lavoisier in 1774, and still 
more lately by Vauquelin,^ It is usually prepared by satu- 
JUiD^ with ftnirnoiiifi the »ii|K'q>boti[)hatc of lime ohmined from 
nm, and t-vitjiontting the solution to ^iich n con->istciicy, thiit 
wlicn allowed to cool the phosphate of aiumanLa is obtained in 
cryftils. For the most complete examination of phosphate of 
ORiiiKinia, we are indebted to Mili-herlicti-H 
I Ha crystals which form (if we leave the saturated solution 
to i^ntnncotu eva|»oration) are large aiid tmoHiMtrent. After 
tile crystals have been deposited the solution is tisually acid. 

The shape of the crystals is an <4>li<)uv rliombie priiun, in 

*bicli M on M' in an angle of g-t" ac, and P o» M 1 05" 23'. 

In the cry»tnU the niigte A, is often replaced by a face, making 

'mc Mmmit of tlte prism consist 

**f two feces like the roof of a 

«»ouje, Thb new lace makes with * 

^ m angle of 1 09* 44'. Some- 

*^Oi«i tlie uiiglew E, E', and O, 

*'*> also rcplured by small triaii- 

fe^tlsr feces. When these crys- 

**ll are exposed to the air, they N. 

^flfcfeace, and at the same time \ 

^^■e a portion of their ammonia, 

T*^ tliat they are at last converted into biphosphate of ammonia. 

^ ^ taato is saline and cooling, with an impreiwioii of bitterness. 

''^dasolves in four times its weight of cold water, bntisdoubt- 

* OeUoa's Jour. iL 56S. f OeMon's New Algcni. ^our. in. VA. 

I Ansals of PhtloM^j- {id nrio), i. 1 10. 

$ Jour, da TEoolc Polyiechniiiuc. 

I Ann. da Chiia. tn <le Vhj*. xix. 389. 

II. Sc 


"- less more soluble in hot \nttr. When heated it melta^ and 
g7»dually l(>)ie<) its ammonia and part of its wau-r, aiMl it conr 
Vrrt«<1 Into )iydrat4><l |iha)ipliorii^ acid. IlscoD<)tituoiits,asd«t«^ 
tained by Mit«h4Yl)«b, ere 

I "> 1 atom pho»pfaorio Acid . . 41*6 i 

"' 'I' f'l atom ammuRia . . . 2-125 

1^ atom water . . . 1*6875 



I ohtatnM S atoms of water; t>ut ait tlio axialyds wan made 
8im|>ly by precipitating tlio acid by motiiis «f uitratc uf lead, the 
KHidt is sontewliat uneertain.* On that aocou lit I r«ther pre- 
fer tlie experiment of Mitclierlicb. 

12. liiphanfihaU tif ammonia. This salt is easily obtniiicd 
by sdduig ])k(Nipkoric acid to a aoliitjou of phmpboM of aouo<^ 
niai till it Htrun|{ly roddi<u<( litmti!* pnpi^r, luid ciaisci to precipi- 
tate muriate of barytes. When the suIuhmi Is uuiiixrttratvd it 
crystallizes readily ia octahedrons With square baHes, haviof 
most commonly a four-sided right priHm interposed betwe«a 
the two pyramidH. lliia is the 8»It tlial Um hiH-ii IoiikoiU known. 
ati<l wliich ia tlf!tcri))i>d in older ehvinin-ul books uuder the nnat 
of phospliute of amtnoiiiit. 

Ita cT^-Htols are traii«parctil, and undergo no alteratien by 
eitposure to the uir. The ta.>te is acid, and cooling, and saliae. 
Wlii-n heated it toelts aiid stvflla up ideally from tin; oMivcr- 
«ioii of tlie water InUt valour, and the extriaUivn of tjw acDine- 
ni(u liy ei>ntiiiniiifr th<; hvM nothing romaina ut lau, bol 
hydrated plionphuric acid. 

I found tlutt 0-05 gniiu of this salt were deoompowd Itf 
41*5 grains of nitrate of lead. l-Vom thb I conclud«d.t))»t tk 
saltisanhydrou.'t.t liut thi«mudeofaiiiily»J8cttnii»tbedepen<M 
on. Tliere ia no doubt tliiit it contains water: becnuu] thw 
liquid ia disengaged when the salt is heated. MJtcherKcb') 
analysU, assisted by a little calculation, gives itn constitutiDn » 
follows : 

2 at<nnB pbosfdioric acid . . 9 

1 atom ammoDia . , , 2-1^ 

I ' > > • 3 atoms water . , . S*37S 

■ jj , , 

>i>ii' M<iiiiiniu> Aii ti^i' 14'5 

19. PAo^a {^aamtmia may bo obtained by ati 


Fir»i TMndples, n. SU. t Ibid. p. S46. 


sboroof ftoU) witir carhonute of ummonia. Wlioii ouiicen- ^^^ >■ 

itt^ii W thfl ocMisinU'iii'v uf n syrupi it ytvUls UigiT crystnls, 

[which ar« very Ju liquescent. When heated it gives out 

' ammonia, and t\w phosphorous acid aiid uraler remain ai if tliey 

had not bectt oomhiited with ammoniiu When die hisii 'a 

iocrettsed, tliia acid is decompont-d in tlie muni wny, and ot liHt 

I ft bydrated phfl«phoric acid remiu'nti.* It has not b«en analyzed, 

but from the phi'iiomcim of its dccompuution there can be little 

}t that it« constituents are 

I atom phosphoronfl acid . . 3-5 

1 atom ammonia . . . 2*ltU> 

2 atoms waU-r . . . 2^5 

'-"■■"'■' ■''■■• -'' ''- •■■■'" 7-875 

Th«r« It bI»o n hiphofpfiiie of etiNiwMiM, but it ban not heen 

partlcnlarly examined. 

U. HjffiopA/igpAite of amiHOnial' This salt Rns heen cxain- 
bed Only by Duloiig. It i^ v«>ry deliquescent, and dLwolvcs 
my midily in wator and al>M)hile idcobol. 

15. Arntninte. of amiiMnifi. Tliis aalt may bo pri-pnrt^l hy 
lUlnjif iimnMnift to n cmtceiitrated solution of arevntc acid till 
t precipilule Dppear. lliis precipitate is dissolved by beat, 
and the liquid being set aside, depositea large ctystali of arse- 
niate of ammonia. i'-< *•■' >'t 

Mitcherlieh lias ahown that the «alt rCWirtbIM pbosphute of 
nnnionia m> clo«ely, tluit we cannot distinguish tliem from each 
ether liy tlieir ^-xtcrnal chaniiteni. They have the same taste, 

I and the crystidllnv shtipe is tlie same, an oblique rhomboidal 
^TBim. Tlie angles dlffiT a very little from those of phosphate 
^eif ammnnia, hnt not so much tliat tliedilTereneo<»)t he detected 
'by thr eye. The mcusuremenU) of arscnuittf uf annuniia are 
IM followH ; 
> M mi M' fUt* 54', or l» 24' greater than in phmphate of 
P oti M 105° 46', or 23' greater than phosphate of ammonia. 
/ (the face on A) on P 109'> 6', or B& leia than in phosphate 
of amnumia. 

»W)ien faeateil, ammonia i» given out, then water, while at 
laiit arsenic sublimes, and azotic gus is oxtricuted. When 
this salt is exposed to the air it loses half its ammonia, and is 
converted into blnaneniate of ammonia. 

I According to tJu^ uiuiiyHU of Mitclierlich il« oonftituenia are _ 
■ n. Ro«e, PuycmdorTi Annalvn, ix. SK ^^fl 
i fl 


ci«" L 1 atom aisenic acid . . 7-S5 

■ 1 atom ammoiria . . <S*tS6 ■ 

1^ atom water . . I-687S : 


My analysis was not sufficient to determine the true consti- 
tution of this salt, as it was made simply by predpitation.-l- 

16. Binarseniaie qf ammonia. Tliis salt is easily formed bf 
adding to a solution of the preceding salt an additioiial dose at 
acid, and then crystallizing, or simply by expoung the preced- 
ing salt for some tiine to die open aii, and theA.disaolvingitin 
water and crystallizing, 

Mitcherlit^ has shown that it r^embles the biphosphate d 
ammonia perfectly in its properties. The descriptiw ofthvon^ 
tliereCoie, applies to the qther. The shape (^ the.j^:gey|tii|Ml 
the same. Its constituents, according to the ai)aly!4W,«f tht 
3ame chemist, are . ..<, i| 

2 atoms arsenic acid . ... H'5 ..,,, ■..,] 
I atom ammonia , . • . 3-135 .„■■; r 

3 atoms water , , . 3-375 , . 

aO'OOOt ,: 
17, Borate of ammonia. It appears from an analysis 1^ 
Berzelius,§ that this salt may be formed and obtained aitrjra- 
tals; but no description of it has been made. He foood the 
constituents as follows : 

Boracic acid . . 37-95 

Ammonia . . 30*32 

Water . . 31-78 , . , 

. He has since stated that thb analysis is not quite acc)uate.i 
comes nearest to 

1 atom boracic add . , 3 

1 atom flmmnnia . , 2-125 

3 atoms water . . 2-25 

7-375 . 

18. Sesgttiborate <if ammonia, ArfVedson formed this salt aw 

• Ann. de Cbim. et de Phja, six. 3S4k 

t Pint PrinriplcB, ii. 246. i Auv de Cbia, et de Pbys. xix. 878. 

^ AiuiBlsofPliilosopbfilii, S?..!: > j| FoggeodorfB AniMles, ii. i8& 

t*lDiuuiIy*!» ; but ho has not ^vvn any description 
_Hc found tho vcitis(itueat8 as follows: 

Bonicic acid . . 65-95 

SM. I. 


Ammonia . . 21-55 

Water . . . 22'50 


8 okvjoiuly tho same as 
1 1 atom boracic acW 
■^ 1 atom aiiuiioiitu 
|P9" fttomH water . . 

W' 8-875 

' TWkwnir nf ammonia. Till* «iU may be fwrmed by 
', boDiric arid to u irarm aqueous solution of ammonia iu 
ntnic proportion, and &vn allowing tlie solution to cool. 
ilaJUzes in octalietlrons M-itli rlioinblc luue<s )ik« mtlpliur, 
lorter, and tlic spiers arc usually truncated. In tliu air 
rnbtm, and gradually becomes scxborate by keini^ umtno- 
It diMoIvcs in ulwiit I'i limes its weight of colli walur. 
I llic solution is beatt^d, ammoniii i;s diaeiigaged. We 
he three following analyses of this suit: 

lOHia . . 13-5 . 12-88 . IQiiA 

di-actd . . 51-0 . 63-34 . 50-000 

cr . . 3fl-5 . 23-78 . 36-452 

100-Of 100-00} &9-990S 

agree best with 

S atAm.4 boracic add , . 8 

1 atom ammonia . . 2-125 

S ntonu water . . 5-625 

Seji/ortUt (j/" ammmia. This wilt may (w formed by 
ing warm liquid lunmonia with bomclv acid, and allow 
e solution to cool slowly. Tlic crystats are traiiMjKirent 
«gular ; but M-etn to be four and six-stdt.'d jirisms, usually 
aUtl by pjiamids. The taste is at fint very sliglit, but 

■ Pn)a:mdorrii Aannlen, ii. 130. 

t L. (tmdin, UiiniU>ui:h, i. iTiL 

t Arfredton, PoREcndorTii Add. it. 190. 

$ Soubciroo, Jour, dc I^honn. li. St. 



OXYOEM Aao ttklTB. 

a Utter imfwvmion U Irft In the mottth. IJke til the nita af 
boracic ncl<l it actSMtinalkalL Wcliari- tlirc* iitudj-AOsof tJm 
snlt, the results of vhicli arc as follows : 

Ammonitt . . 5-9 . 7-6 . 7-24 

Boracic acid . . eS** . 64-0 . 66'»0 

Water . . 30-7 . 28-1 . 38-96 

'•• ' lOChO* 

Tliese Hgree best with 

6 fttoin.t homcic an<i 
1 atom nmmuiiiu 
•t «ujhni;7«toiw water 

It is therefore a sexborate of ammonia. 

Qt. SMcate of ammonia. Wlien iiewly precipitat«i (Bmi 
b digented in an aqueous Hotutiun of caustic aminonia, a eafr 
tldemhte portion of it is disKolvpd. But <srboiiat<i of p""*"*^ _ 
diwolve* v«r)- little of it.} I 

22. Sf/eniate ^ammonia. Not y*t dottcribtd. 

23. Sftenite o/imtmma. Tliis »«l( is obtained by adding 
Belenious ncid to concontiated cuu8tJ« ammoitia till there be* 
small excess of acid. M'heii tbv aolutlon i« left in a cool placft 
the suit preci])itatea partly in fonr-ttded priemis And partly iu 
feather shaped crystab. They deliquesce whpn ejcpoei^l to the 

2-1. Jiistlenite <\f amtiwtiia is formed when the neutnil itcl&- 1 
nile is dissoh-vd in water, and the liquid is left to spontuncous I 
evaporation. A portion of (be ammonia Hen off, and the Ih*^ j 
lenite is deposited in acieular crystals, which undergo no 
change, though t-xpiised to tJii- air. 

25. (^HaUrsdc^iilv ofanimuttia is obtained either by heating 
a solution of bi&olenilc, or by adding selenic acid to the bis»- ■ 
lenite. It does not crj'slalliie, and when evaporated to dry- 
ness, spcwiily idMwrbs moiittun- from llie ntnuispln-re. |t 

30. Afitimimiale (^ammonia. ThU eombination has hitherto 
bten examined by UerK-Iius ontj-. It may be formod by 
'digeMiiig the hydrate of antimonie aci<l in wustlc MBgiO ldi« 


* L. timdio, Schweisgcr*!! Jour. xv. OM. 

t AtfredMO, Pvcgendotf li Ann. ii 13a 

f Soubainu^ Jour, de Pharm. %\. M. 

$ Kanlcn, t'oggcndofTii Annnlen, *i. S6T. 

I BcrwUiii, Ann. de (him. ct He Phfs. ix. £«)■ 

A arutnil solutioD fe ipwlimlty forcocdL If fve attempt to era- _ 
puiutw it III portiuu (if Uit! ummiiiiiu It •Unengaged and a white 
powiler foils wliicJi i^attiipcmiiuimHiiiiiv of oiomoiiia. It red- 
iepa vegetable bines, and when beated in a returt nmmoniu nnd 
vater arc driven off, and autimoiiicacid remains beLind. TlitH 
■ipgwh ia not d«coin|Ki»ed by exposure to ttie air for months, 
jren ut tlic tempvniUire uf l±f.' 

■ < 27. j^M/iiHonite <{/' (iimnMita. If tlic hnttmouioiM acid b« 
£tfcatcd ill caii.^licummofliaasoliition is obtHinvd. Wlunitliis 
■olution ia exposed to the air a vluie precipitutv lulls, wliitrli U 
a binaniimtndie of ammonia, i 

3& Tdiurntf. of taumtmia. When oxide of telluriuis it 
digested in csuutic ammuniii a soliitioii h obtained. An iLcid 
dropped into tUs Miltition pn-dpttatra a wliitc pon-der, wkicb 
ii a bitellurati' of animoDia.t 

38. Chromale of ammoaia, Tliiit salt may be formed by 
Mantiiifp «Jiron)ic acid witii aininoniu, and concentratijig tlir 
■lilim under lii« exluiiutvil rwceivvrufan (lir-putnp oversul- 
plnric acid. Tb« wdl It ^nidunlly depmit«d iu crystalUne 
mles. It hu a fine yellow colour, a l)ot and saline taste. It 
upon vegetable blues like an alkaU4 It iuvxceedinj^ly 
ioble in water, and tl»e solution cannot be conwntrated; by 
twitliont di^priviii^ the wdt of Italfof itaanunoiun.,. i foHIld 

Bf^rou*, and ciiiiipuHtid uf , ii. .i|i 

I ■•I.J atom dirumic teU 6'^ .,-it 

1 atom ammonia , . . 2'12d ^^ 

,.|i>. ,,i 6'6'i^ , .|n. 

BidtromaU t^ atmiumia b always obtained wheit we 
concentrate tho wlution of ilie prect^ling NtU on tlie sand batJi. 
The bieiirumate iii deposited iu lieaiilifiil crvetuUine plaCes, 
wltiL'li are uot altered by ex|>0(iur« to tlte uir. liliaaafino red 
culour. 'i'be laste i» bol, bitlor, and very di!ia){reeiible. . Jt 
reddeiUL ve^etublc bliifSk, and in very »«)ltible e- 

in fralt-r. 'Vhv- piiinitry fi^pire uf it« cTyaluln, 
•ecordiDi^to Mr. Urooke^^isanobltquertiom- 
lii*.- priMih iwviiiK itA edges repiuwd with faccn 
■» rvpreai-ntod in tlie taaigin. Tbe followinin; 
are tlie measurements of tW principal angles. 

t*Kkbolwo'tJounyl,xxxv.40. -tfioncdimi.NiclwlMB'tJoitf. ixivi. 131. 
I I hare however obtained it in a «ato inupablo nS giving o blue colour 
redilencd liUiu* poper. 
i AHoila oT rfailoMphr <8d MOmX «i 967. 


899 oxyoHir. acid uxts. 

cu-L PonMorM' 




M Mlg 


98" 8' 

isa" 81' 

139" 4' 
136* 47' 

When lieated, it melts, aad loses its water and aimaonBL;.^ 
dark green matter remains, which qieedUy beoomes solii^ 
exhibiting the rudiments of cryBtaliizalioa on the m&oe, lliii 
matter is brittle, has a cooling and sharp tast^ and partly dia- 
solres in water, forming a deep yellow solution, and partly 
remains in the state of a deep green insolubie matter. Tliii 
matter seems to be a chromate of chnmiiiuD. This nUt, hf 
my analysis, is a compoond of . • 

S atoms chromic acid , , 13 
1 atom ammonia . . . 2*126',.' 

a atoms water . . 3-25 t 


91. Moljfbdak of ammonia. This salt is formed vhsf 

Hiolybdio acid is digested in caustic ammonia to satturariaifc 

When the filtered solution is set asides crystals of molybdat^ 

of anunonia are gradually deposited. These crystals ate iner 

gular four-sided rectangular prisms. The taste of the aalt it 

bitterish, saUne, and metallic. When heated, it gives oat 

water, ammonia, and asote, and leaves a brown oxide or molyfr-. 

die acid, according to the degree of heat It disstdTes i> 

aboat twice its weight of water, and when the aqueous solut^ 

is ooncentrated it gives out ammonia. It has not been tifpt^ 

uialyzed, but from the experiments of Bcandes, there is leaffB 

to oonmder it as a compound of .,;.i 

1 atom molybdic add . , 9 

1 atom ammonia . . 2-125 

I atran water . . . 0-6635 

32. Bimolybdate of ammonia. When the solution of dw 
preceding salt is concentrated by heat, half the ammonia il 
driven oif, and when the concentrated solution is set aside, 
large crystals of bimolybdate of ammonia make their appeB^■ 
ance, the shape of which has been described by Uaidinger.* 
"When heated, they give out ammonia, water, and asQte, aad 

• Bdn. Jour, of Science i. 100. 

skjjra ov MiMotnAv 

aab grey substuncc, the nature of which has not be«n 

83. Bitimff«tar« »f ammonia. This salt may be formed by 
dissolving tiing^tic aci<l in caustic ammoiiiu. Wlii^n the coii- 
iviitniUMl solution is set aside, small ^vliite crystals are dejjo- 

ftitMl, oonilioMd of foar-f<iHed priitini;, iuid very little w>lub]4! in 
y/tOH. 'IthiMnsliiin), hiittT, metuUiciastc. ItsconstiluentsaM 
■"^ -" ' 2 Bloms tiing«t(c Held . . ii\ " i 

I nlom ammonia . . . 2*l'ii5 
'i atoms water . . . it^i 

Tliere is another tiingi^tate of ammonia, much more soluble in 
•liter, which is probably a neutniJ lungWitv, but it hus uo( yet 
Keen anatj'xed. 

34. 'J'itamaU of ammonia. When ammonia U poured into 
tb« milk conid^ng of hydrated titanic acid and water, flocks 
immedintely scpainte, which arc easily collected on tlie filt«r,* 
These flockfl probably constitute a titaniutc of ammonia. '' 

35. Cnhttntitite of ammonia. When the hydrate of coltimbie 
iHd i* tli^-sted in caiu«tie ammonia, a combination is formed, 
wMc^ rrinain^ M>lid and does not redden litmus paper. From 

I ihis com)wund the ammonia I« e«wly expelled by heat, or er^n 
ky simple cxpiwurf to Iho air. Hy means of this lutlt other 
1 eolumbailcfl may hp formed hy Hotible iiecomposid<>n.t Coitun- 
lilt- acid k very Utile iM)hit<lc in cnrhonate of iiminoniiu 
1 ■■ 36. Vrmriate t(f tirHinimia. When nili*t4'd pcro.xido of ura- 
JB) \n Aolution is decompoMcd b)- ammonia ii yollow powder 
[Ub, which Is a uraniate of ammonia. This salt may bo ex- 
'jMsed to a lii-at of '2\'l'' witlitiut alteration. When the heat 
spprouclies to redness it is decomponcd, ammonia and azotic 
frns being driven off and protoxide of nriiniiim remaining. It 
is slightly soluble in water, but not in licpiid ammonia. From 
By ttiala on it I consider it as a compound of 
, I atom peroxide of uranium 38 

1 atom Hinmonift . ,<•<(>> V' fi'lSS ' U ^ 
Ij atom wiiter . 1-6875 

CM. I. 

Oxalate ofarnmonia. This well-known and rcry useful 
tntlt is Dbtatn«cl by saturating a solution of oxalic acid with 

* H. note. -t Oahn, Benclhia, and %gcnr. 

W4 oxrosii ACID siLxa, 

a—t. oarbonate of BtDnw&iB, uid after ooncflntntii^ dte Uqiudflet- 
tiug^ it aside for cry§tallization. The crystals are usually needle 
ibnn. But they may be obtained in rigbt rhombic pnKn% tiu 
bees of which are iucUoed at ang^les of 104° 7'. The longt* 
tudinal edgea of the prism are often repUced by tangent piane% 
while the angles at the base are also often replaced by una m 
two small feces.* 

Tlie taste of this salt is bitter and nnplcaMat, somewhat like 
that of sal ammoniac. The spedfic gravity of the eryslakil 
1.682. At the temperature of 60° 100 ports of water diaei^ 
only 4>5 parts of t^ salt. The specific gravity of the aolntin 
is 1-0186. This salt is insoluble in alcohoL When dislilkil, 
catbonate of ammonia is disengaged, a little of the- anid N 
sublimed, and a residuum of chwcool remains behia^L Tltii 
salt is much used as a reactive to detect the i^euiifia^ 

When heated it gives off one atom water, and is coDvciied 
into a white opaque mass. By a higher teii)qi>etature it is oOBk- 
pletely decomposed. Its constituents are 

1 atom osalic acid , . 4-5 

1 atom ammonia . . 3'125 

2 atoms water . . S-25 

8& Biwaaiate (^ amrnumia. This salt may be fanned by 
adding oxalic, sulphuric, nitric, or muriatic acid to a fiobftin 
ofoxalabe ofammonia and setting the soludmi aside (Buffioie>4f 
fMHicentnited) for crystallisadoD. 

Hie crystals of this salt are sometimeB octahedroUi Jnt 
moat commonly rectangular flat four-uded prisms, having tv* 
opposite lateral edges replaced by tangent planes. The t«M 
of the salt is acid. It reddens vegetable blues, -and is sot 
altered by exposure to the air. I found the eoiutitu^tta;^ 

Q atoms oxalic add . . 9 
1 atom ammonia . . 2-125 
6 atoms water , . B 

30. Acetaie ^ammonia. This salt has been long employad 

* Mr. Brooke hns pren a descripdon of the cryitals in the AomIi ^ 
FtiloMphf (second aeries), yL 374 
t BergnuQ, L 861. 


BMllcine nnder tbo name of ^rituM mitHkrtri. It h easily ""•• *• 
|Kre«l by satunuiiig iKVlic acid uiih mrlwriHtv of amnio uia; 
w fnit tht ntuniC4>cl solution under the exliauued receiver 
B air-pump orrr sulphuric acid, the acetalt- cryMallizei in 
Bpan*nt obliqae rhootbaidal prwaiii, 'J'li(< &c«k art' striated, 
ithe Mlt ao deliquescent, tJtat th«y caiimtt )ir iBComunrd. It 
naaas tite lotif^ut.- iit fjnt with u svasc of coMnns, and then 
fWl M t , vrhitih is followed by a taste resembling; that of a 
liire of sugnr and nitre, in n'litcli tbo Aweet doi)* not pre- 
Itnate om d>e inau'kii}i la«ti> of ttie nitre.' It molts at 
P^'and tuMioies at about SdO'.f \Vh«n n watery dolutioo 
bto Mlt ui dUtilled, tlirro coaifs over firrt a quantity of anb- 
im, nrxt a quantity of ucotie atrid, and at huK of the salt 
If coDtJiininf; an exeeaa of acid. No auch dcooapo&ilion 
to place wh«n the crjatals are distilled by a moderate hmt.4 
lOrding to my trials, 4U gmim of tlie crj^tUils dissolved in 
»r and digeal^l over calcareous spar in powder, dissolve 
i graina of carbonaM «f UiBft l-'nHQ tliis it follonfi tliat the 
it coinpo»e<l of "■ tiuiii 

I atom ncrtic acid . . 6-'26 
atom Eunmonta ■ • '2'1'26 

7 atoms water . . 7-875 

I. BmacHaie ofammtmia. When the nqueoua solution of 
ediiii/ mU i» heated it giv^ out half of itH ammonia. 
e hcnt bo eontiiiued the binucetate Httblimes in needle- 
I cry<jliils. The same salt may be ohtiiined by heatin)^ a 
turv of amiale of potash or lime aiid ttal ammoniac This 
dcliquescwt when exposed to the ait. It8 taMc is »our> 

Ntidens ve^emble blues, 

; fimiate of' ammonia. This Mtit litM been but iin[K<r> 

examined. It cryUallixtfs in ri|;ht rvctungular prisma, 

y tenniiiiilird by foiir-i>i(ied pyramid)). It is readily 

in water, and may be sublimed withont decomposition. 

»rdiiis; to Dobereiaer, when strongly heated it is decom- 

tl into water and hydrocyanic uciil. 

iL MflUUe t^ ammonia. 'Wvi salt is formed when mellit« 
nled Id a noltition of carbonate of ammonia. 'Vive ooiiceii- 
kI solution readily yields erystab of mellaie of aDintonia. 
y are transparent and colourless, and the f>!ilt crystallizes in 
dilTerent forms, wluch hare been desciibed and figured by 
• UieBins on A<«lau* Add, p. IK. t Ibiil t ^^- 



o**!- O. Rom.* The fint is a rhomboidal pnsm, vboae Ikea ue 
inclined to each other at angles of 119i> 41', while in Ae«ltwr 
the incfinalion !b 114° W. The first terminates by afoor-ttded 
pyramid, whose &ces are set on the lateiai ftces of the -pnaOf 
and whose apices are truncated ; while the other teratimMf 
in two faces rising' from the angle of the prism Cerminatingthe 
obtuse inclination. The first kind of cryst^ remain aaatb^ 
time unaltered in the ur, and then becomes milk white tad 
opaqne without losing its shape. The second farm becoBSi 
opaque instantly when taken out of tbe solution, and erenwhUa 
still moist Wiihler, who observed these alterations, does not 
consider t}iem as owing to tlie eso^ of water, but to a «ew 
arrangement of tJie piuticles of the crysbtLf Indeed thk 
change in the appearance of the salt by exposure had bwB 
noticed by Klaproth.;]: 

43. Tartrate of ammonia. The crystals of this salt are 
polygonous prisms, not unlike lliose of tartrate of soda. It bai 
a bitter taste like that of nitre. It is very soluble in wilM. 
Heat decomposes it. Its constituents are 

1 atom tartaric acid . . 6-25 
I atom ammonia . . S-125 


44. Bitartrate of ammonia. This salt was first noticed bjf 
RetzTus. It is almost as insoluble in water as bitartnte tt 
potash. Hence, when to a concentrated ammoniocal MlirtioB 
an excess of tartaric acid is added, abnost the whole alUi 
becomes solid. 

45. Vinate of ammonia. This salt, according to iafc% 
crystallizes in needle-form crystals, conEOsting of rfanmbaiM 
prisms. They are transparent, but efSoresce when exposed 
to the air. 

46. Pyrotartrate of ammonia crystallizes, according to Rose, 
in plates. 

47. Citrate of ammonia. This salt, formed by dissolviif 
carbonate of ammonia in citric acid, does not crystallize tiUib 
solution be evaporated to the consistency of a thidt synip. lb 
crystals are elongated prisms. It is very soluble in wafer* 
Its taste is cooling and moderately saline.^ Ilie amramiBS 
separated by the application of lieatH 

• Poggendorfs Annalen, vii. 335. t WShler, ibid. 331. 

t Beitn«e, iii. 131. f DobMxi. | Schede. 



SALTS or AMMOKIA. ^^^^V 9S7 

48. Pyrocitraie ^amtrnmia. N«l exiunioed. »^*- " j 

■41k MaiaU ofammntia. Tbia mlt is vMy wlnbl© iiL.lfVMrt Z 

MJUtw not cryaullu*!. 

iO. BitHtUate t^atmmmia. It fonns crj'slals not itltcrcd by 
utpoeure \a tlte air, aiid insoluble iii aluobol, as is eV)il.OD(,^i>in 
ibe experimeuts uf Donwan, • 

h\. Funijalr of ammiMin. Tim sill proluiMy in tlie stutf of 
bi/uiiKnU', crystal li:tuii in ux-tidcd pri'ons, witli two of tlic 
•pfwsite facm much Jarget Uian the rest, and tcnniuatJng in 
tm iaveH ^t on ilie lar^e £ices of tlie prism, and by mpeting, 
KTBuitnliiit; lik« the roof of a bous«. It is soluble iii twice il« 
wmy^ia. of cold water.* 

m, Mncatt of ammrmia. Formed by digesting mucic acid 
id a volution of luaiuoiiia. When evaporated, a SiiUue cruftt 
mnaiaft, liaviog a ludl tiwttt. Wluin Wated, ammonia is fint 
given off. tbea the mucic acid itiidrrgorH <lecompo»ition.f 

M. J't/ramueafe t^f ammonia. When tJiciieuIial solution is 
Mooiitnitrd by t:va|H>Tation, it g;irea out lialf of its ammonia, 
tml ia conveitod ijil» bipfftomveaU (^fatnnumia, wbtcb crystal- 
iiws-t . ...,,-,,..■, , 

54. Suceittate tff ammonia, Tliia salt U easily formed by 
Wuniing ^uecink acid with carbonate of ammonia, and con- 
CFotimtini; (be filtered solution. The crystals are oblique rhom- 
Mc j.rism% the &c««of which are inclJiu-d at angles of 100" 15'. 
He iiiclinatiun of th« base of the priem, to onv of the contigu- 
«u Anea is 91° 53', to the other 93° tU'. The acute latvral 
K%M of the prism are often replaced hy lang<^nt plunes. So 
«■ the oltttnate (ermiiial e(lg;i.'>.S It Kub a sliHrp, hitter, and 
tooling taste ; wIk-u exposed to hnit, it sublimes without decom- 
poiidoii. It doli(pie«ccs wbrn exposed to theuir. Itacon- 
lliftwBti I CDUMdur us 

1 atom succinic acid . . 6-^ 

I atom ammonia . • • > 2-125 

SatomawalOTi,,,.,^,,-,,^,, . 2-25 



ii. BmzooU of ammtmia. Thl» anlt a eaidl); formed by 

H IBtuniting iKiixoic acid mixed n ilh water, with carbonate of 
I AOMnonia. When the solution is sulEciently conccatrated, (tak- 
ing «wra to add ammonia as it is discngiigcd,) it depoiutes ern- 

■ • BncoiMiM, Ami. dc t^hun, hm- SDS. 'ilii:iiUp(u -JtU vd lminiM» 

■ f SriiMJe ind Tromiidorf. 

H { LabtllBTdKTc. S Brookr, AunsUof riiilosofhj(2dMriM),ti.t8e. 




oxtobh acid salts. 

tuls in sqtiarc plates with livvclled ivlpfc*, ««inin|i[ly oetahetlrona, 

with tiK-ir iipiti-K (li;<r|ily truncated. Tlirsv cryataU iinri' a 

oodiiig; aad uriiious tast^i aiid leave an impTeMion in the mouth 

like that of benzoic acid. They undergo no change when 

txpOHiHt to tlienir. Their spccilic gnivlty is 1-414. OnefMrt 

diiwolTes vmuly in three purbt of Iwt-wilCT, b«it a i^<.Nit purtlml ' 

ii dflpositcd in cryHtul* aft the solution cools. Its eonstilueiiBi ars 

I atom bonioic acid . . 15 

1 atom ammonia . . 2-1S5 

1 atom wal«r . . 1-125 


56. mhm:'Kitc of mmwmi'i, \Vh*n the pi^crdinf; aalttt^ 
left exposed to the sir, it (gradually piirtn with half of its ammo* 
nia, and becomoii bibuitzoatc, which crystalUxm (n feaUier> 
shapvd crytitals, very littltt mluble in water, and still le« ta j 
nhiolute alcohol. 

67. (ia/ltiif if ammonia. Gallic acid WM di-tsoIvH in water, 
and the st^ution hein^ mined wiUi an oxcc«tg of mrboiMte nf 
ammonia, was pWvd over sulphuric acid in the vantum of an 
air-ptimp, to ^t rid of the excew of wat«r and ammotiiB. After 
tlie evaporation n yf^tlowiKlHgray salt remained, which betanit 
green or brown wlion expmod to the air.* 

i>8i, Mtrmate of ammonia. This naJt may In- obtained h^ 

mixinj; together two parta of «il ammoniac and thre(> |iart« of 

meeonate of barytnt, and opplyinfr heat The mcccutnte ef 

ammonia •iiiblim«>«. If, cryMidtize^, according to John, in fi)U^ 

siih'd pmrnn, which are transparent, mid not alter<>d by expotiuTC 

to tlic air. They dissolve In \\ times th«lr weight of wattr. 

Whwi the crj'HCals obtained from soltition in tvaler ar<> h«nt«d, 

they lose water, an<l then the salt sabliuie*. According 

Chouluiit this wilt K cumjMsed of 

<"<■..<' Meeonicacid . . 40 

Ammonia ... 42 

Water ... Id 

lOOf __ 

59. lioletale of ammonia. It crystallize)) in fi)iir-<ided prisiffl<< 
not altered by expOKuri' to the air. 'IVte inline, and sooe- 
what sour. When hvatcd it melts and may be iiubltm<>d.f ' 

CO. AViKite of ammonia. Wh«n the aatumtcd 8olut40in>f 

* Bendiu*. 
t DnconnoL, 

i Gilbert's Aiinnlcn, Ivi. 3W. 



Iiinic acid by ainnioiiiia in evaporateil, it loom half in ammonia, 
tn<l in that Rtate caanot be regularly orvAitiiiixi-il.' 

61. CamphortUt vf ammonia, I'liix salt crvBtaUiEes in fine 
Bccdle*, wliich bec(nn« moi»t by oxpaiurc tothcair. 11il> iaM9 
h sliHTp and saliiir. It it) iwlublc in tlirco times its w^i|;llt of 
biiiting wiitor; but l««s soluble in oatd water. It n Holubte 
HkewiM to abwlute aloobol. When healed itmolls, gives out 
uRmuiiLt, and in decom]>o<ted, leavinir a qnantity of charcoal. t 

Wtii-ii tli« snlutioii uf it ill wiiter is boiled, it ^vea out half 
la ammoniut an<l in converted into hicamphorate ofnmmimia. 

ttS. SiAeraie (>/' ammonia. lliLs salt may be formed by 
stunitin]^ nberio acid by carbonate of ammonia, and then 8ul>- 
jr(?tin(( Ute «olii(ii>u to «[K>ntsue(>iiH erapomtion. Bmndra, by 
this proer«i obbiined it cryHtalli/c^d in needier, and in silky, 
wiiit*, four-«idod priHini). It hiM a iiliarp saline taste, and la 
ftry soluble in water. When heated it melts, and ia afterwards 

ftiL SteanUe of ammonia. This salt may be formed lu the 
I'tng manner : Put into a iiarrou' and bent n^lass tubv four 
s orhydmteilsttiU-icacidandfiM- it. After it has become 
lotkl, till tlie lube with incr<:nr)',ai»d let op into it 1-6 cubic inches 
«f aiomvolaual gvf. Jleat the avid sufficiently to melt it, and 
then leave the whole lo the mutual reaction of the two consti- 
twnu. rite absorption is at first ranid, and it continues even 
lifter il)« mad ha* l>ei.'ome xoUd. When iJie alisorptJon is at 
tn and, the pnicen is liiiislted. The ubsorption continues for 
iboQta month, and the quantity of uinmoniu absorbed amounta 
lo I'liU cubic inches. The salt la obviomly coinp««c'd of an 
iftoOk o( eacli constituent. It ia white, and without lonell, but 
Ikm au alltalijie taste. It inu)' W suhiimeil in vacuo, ^\1u.•n 
listillitl in n retort, umiminiii iw <li>engaj|fed, U'ater appears, and 
[tbere tiiblimea a subAtcamte mixed with empyreumatic oil. ' It 
duaolvex in hot Wuler, at leant in ammouiacnl wau-r. On cool- 
btg B litKteitratf is ile{M)Mil*.-<l in brilliant scales.} 

64. Margaratft;f ammonia. Mai^arioacklacDtupunammt^ 
ntacul i^is preelM'iy as Bttittric acid, excepting that tlie absorption 
U somewliat slower. The quaotity uf ^pA absorbed is sensibly 
HBine as by stearic add. The salt may he formed ahm by 
IviuK the acid in litiuid ammonia. When heated in vacuo 
this Mil bebares like stcnrate of ammuniiL It dixcolvea in hot 

*■' •Hmry •«<! Ptiwoo. Ann. dc Chim. rl do Phys, xli. 3W. 
f BrandM, S(liwtigg«r'« J»ur. Dixriij. ml. | Ibid. »xni. 80. 
Cbcvretil, Mir k* corps gr**, p. 30. 




P^ L vater, at least if tltat UquM contain anunoniiL The toliili 

on cooling lets &1J liimArgamte of ammonia in pearly scales. 
When exposed to the air »t 50* it lets a portion of ita anunoiii 

65. 0/tfite fif ammonia. Wlien oleic aci«l is placed id 
tact with liquid ammoiiiuincoinUiiiittioii tuk«s place Immediatel 
A gclulitioiiH salt is formed, wliit-)i <li».iolves c»nipl(-t<-ly in 
BE the temperature of 60". M'licn boiled, ammooia is 
ga^d, and tlie liquid becomes muddy, 

4}6. P/tiiTt^M/itr: iif ammiiHia. When a glaM tube, filled 
pfaoccnic acid, is let up into ammoniacal gas, cryxuilit are 
dually fonned without tbir appearance of auy wbite 
The absorption f^ctes on slowly, and lJii« crj-atals dissolre into 
colourless luid transparent liijuid. U would appear from 
that there are two phoceiiittcs of ammonia, tbc one solid 
tlie other liquid. t 

67. Butj/rate of amiitoma. Hutyric acid acts upon ammont- 
acal gas jkrecisely as jihoconic acid does. Crystals arc formril 
at find, which ar(> finally dissolved into a liquid, which is tfaidc, 
but tnuvsparent and colourless.] 

68. Caproate of ammonia. Tlie action of caproic aidd oa 
ammoiiiftcal gas b precisely similar to that of butyric and pb^ 
eenic acid.$ 

69. ChiAtMeratfofannnoKiti, Browiii*li- yellow, deliquescing. 

70. Pinale. of ammonia. Pinioocid is easily dissolved by llw 
assistance of heat in cauMlic ammonia. When the solutioa ooob^ 
the piiiat^ of ammonia pn*C)piutles in a slimy, thick sMb 
When boiled a {lortion of the lunnionia L> di^ciigugcd, and by 
continuing tJie livat the whole alcohol is driven off, and thaB 
piiiic acid remains behind. || ^ 

71. Silvatc of ammonia. Tliis salt b formed when a solution 
of sal ammoniac is poured into liquid silvate of jioiaKh. Silralf 
of ammonia precipitates in the state of a white tarry-like faydntc. 
It dissolves iu 200 times its weight of cold water; but is rtrf 
soluble ill alcohol and ether. 'I'hi- alcoholic solution lose* hj 
boiling the greater part of its ammonia, and acquires the pro- 
perty of reddening litmus paper. The aqueous aolutioii <le«an- 
poMs the intrlfay mibt. 

73. Carbazolate <f ammonia. Thissnlt forms very long, flal> 
brilliant crystals, having a light yellow colour, luid very soluble 

■ Chcrrciil, lur lc« corp* gnis, p, 7ft -f Ibid. p. 1 14. 
):niid.p. I.'j3. $ Ibid. p. I W, 

g Unvcrctorbcn, PoggrniJorf** Aniudoo, si. 23], 


flit kt ■) tl> It ^*.M tU 


I ml ^ ■ 'I '- .fu* 

r. when litiaU-d iti u gUiw t«)l>o dvy melt, ud are sk^ n. 

|tolaUIUc<l ti-illiout ilecfimposidnn. When aiiddciil}- Iteated tliU 
jialt miclti'H Rre, diiiI ItiiriiH quietly, leaving n great r[ii3iility uf 
[duin.'v^) unconsumecL* 

73. Jitdiffotnie <if aauuonitu TIiia ult cr)'N(allu«s in very 
[Iptij^ six-sided ptUm*. irau^pareiH. and Iiavinjf die yellow colour 

U wine. It cnntaitis iii> wuier »)' (Tjiilalliiutloti, nud may l>e 

•uldimed without dccomjxMgiiuii.f 

I" 1 i" 'riilr fj/" timmtmia- Tb"'* w»ll caii only Ijc obttttiied in 
i< or H wliih> powder. It i'i pretry ttoiiihW in hot, but 

rtry spuriiigly soluble in void wiitvr. Dr. I'ruut ha^ rendered 
it probable tliiit it is in tlw otutv uf urato of ammonia, that uric 
^id exists in urine. It sumetimcs constitutes urinary oiluuli. 
They have much the appearance of clay, occur most cummouly 
U tbc bladders of Very young persons, and tltcir presence a 
iiulicaled by an uncommon degree of excitability in the patieBt> 
■» much «o that the l<-:m nllWo^lli^(u^bImcc tliron-slumintaa 
•tale npproucliiiig convuUton.s, I luive seen this speries of 
alcutus extracted from four or five diUdren not older ibaa four 

75. Sulfiloritiate (^f ttmrnoaia. Tliis »alt is very soluble iu 
Miter, iiti<l cryHtallizeK partly In cubes, partly in «ctahedrom.| 

76. Xani/uiie of ammoniu. This salt may l>« formed by 
limiting s.'intliic acid witli carbonate of ammonia. It may ha 

luhtimed without sllcrallon, and is ver)' soluble In n-ater.f 

77. SuljtfHM/rjjJuhtitate of ammonia. Sulpbonapbtbalic acid 
fiinns with ammonia, a sidt impcrfecliy crytttalliuis not delj- 
qoescent, hut drying when e.tpo^ed to the air. Taste sulinc 
;1Ui<l cooling. It (tis»ulves rcatlily in ivater and alcohol, ^^'hc^ 
Wu-d on platinum ftul it molts, becomes blacki burns mth 
Bamr, and leaves a carbonaceous acid sulphate of araiDOniai 
vhielil'y farther heat is entirely dissipated. \VheniU dilution ui 
evnpomted, it is converted into bitu/pJumap/i/AalaUohmmMiin. |1 

Ammonin enters into llie composition of many duuhli' walta. 
The most importjmt of ih<-s4' u-iU be given at the cud of tliit^ 
tion of tlie simple oxygon suits. .^^ 


t. Ill* «dts of potash, a very few excepted, are soluble in ""'^^*< 

• Ann. d« tliim. cC He I'hju. \x\v. SI. t QiU. sli. 179. 

t Vogel, Ann. de Chim. ct t\e P\>yt. xiu. 66. 
( Zewc, SchwHRGCr's Jotir. xli. ITS. 




water. But in general they are lesa noluble tlum those of 

'2. Maiiy of tlicm cnii bo obUincd in tlie state of crystalit 
but niiiny of tlitm likcwirtf refuse to trystaJlizc. Iii gencnl 
the salEs of potash liavc a Icbb tendency to fomi regular crystaU 
than the m\t» of soda. 

a. If tartiiric acid, dissolved in watrr, be dropfved into an 
iiqueous sohitioii of a salt of potash, the liquid speedily depoeitca 
a white gronuW Beditnent. This sedimeut has a sour ta»lc, 
and coiiNiftta of sroall cryilhb of eream of tartar. 

4. If a solution of siiljdmie of uliimin.i he dropped into a nil 
of potash, octahcdriil crystals of alum arc very noon depotnteJ. 

6. The .salts of potash may he exposed to a red heat u-ith- 
out heinE^ volatilized like the salts of ammonia. If the add 
con(imi(-d in (lie salt be combuHtible, it It deeompotie^t, and 
carbonate of pota&li^ mixed willi a litth* charc«wl, remin 
behind. If the acid is not combustible the tolt usiutlly ftUM 
and its nature Is not altered : though to this there are sotne 
exception.';. Thus the nitric acid is gradually decomposed al 
a red heat, sulphurous acid lets sulphur sublime, and ia con- 
verted into sulphuric acid, phosphorous acid allows phocpliu- 
retted hydrogen to escape, and U convertei) into phosphoric adii 

G. Th<: aalts of potash are not precipitated by itifudoR of. 
nutgnlls nor by pnissiate of potash. 4 

7. They arc not affected by sulphuretted hydrogen gas, w 
by the addition of a hydrosulphuret, except when (heir had h» 
B metal for its basis. In which' case the acid may be dMMn 
posed and precipitated, and tlic potii»li left behind. 

8. When a solution of phitiuum is dropped into b salt oC 
potaxh, »ii omiige-eolourcd precipitate apjtears. 

Sulphate of alumina and muriate of platinum are pTecJ]Htilei 
also by salts of ammonia. We must, therefore, in onler 
know whether a salt so precipitated, contains ammonb ot 
potash for its base, c.ic])0«c it to u red heaL If it be 
amnioniacal salt it will be dissipated or decomposed, leann^ 
the iiiiil. But a potash salt will either not be altered, (tf »■ 
will leave cu-lionate of potasli behind. 

A Hilt witli l»ise of potash may be distingulslied by the blutr" 
pipe in the followtug maimer: Fii«c before tlie bloW'p^ 
little bora.x, to which a small ]>ortion of oxide of nickel hnt bta 
added. A yellowish glass is oUbuiied, Fuse this bead willi > 
little of tlie salt under examination : if it contain potoak 1^ 
bead will assume a hiuitJi colour. 


Kp. 1. SntfiAn/f: of j>otarA, This salt was known at n very 
early period »f (lie liisiory of llie science, ftiid n urent variety 
of iuimo« »rp ^ncii tn it, iiCL-ortttrig to tlic miinner of forming 
% or the fiincy of tlie operator. Some of these iiantes were, 
tpee^fitwm purffatu, tiitrtim Jixum, arcantim dupliattmn, panacea 
iolmiiica, sai tie diMhuf, sat jiofifrhrrxt ff/aKrri, &c. ; but it vna 
Mmmniily Ictioivii by tlie nsimo nf ritriiJnffil trirfar, till the 
French eh«inistM vniied it «n/;rfw/cf//jo?nsA, when they formed 
tiicir new nomenolalurc In 17a7." 

Stilphiite of [lotiutli, or perhaps thfl bisulpliate, wasdlicovered 
bjr »xaminin^ what romaineil in the retort after the preparation 
if nitric aeid, by distilling a mixture of sulphuric ncid and 
nitre. It was the nit olittinod from tliis residuum tliat wan 
oUed jtatuuxn duiJicntn or ttrtaHum itujiliealum. 'V\u- Duke 
«riToUt«in, sometime before the year 1063, purchased the 
prtpatatton of tliin suit for 500 dollars as a remedy in fevers, 
Mne, and sciirv-j-.f 

Sul|>liiite uf potash ts easily procured by saturating the acid 
nit (which remains after the preparation of nitric acid) with 
pKvJi, and *ettiiig it aside to crystalliKe. The primary fonn cit>ui. 
fS^v crystal tK a right rhombic prism, tlte faces of which meet 
ilU|^M of I'JO* 6o'. Mont commonly two of the opposite 
iHtnl edges are replaced by tangent plaiicK, converting the 
oynab into a !«ix-si<ied prism. The edges of the base of the 
primi are also replaced by planes, which convert the end of the 
pnvn into a pyramid, either complete or wanting tlie apex- 
IV figure in tlie margin represents the mmt 
usual ahape. P. ^f and Kl' are the faci-s of the>i 
printry figure, A tlie face formed by replacingi 
°iic of the hitcml edges, and c, i?, ( the pyramidal 
'utsaade by replacing the tenninal oilgeft. The 
■Msniremciits of tliese tace^, made by Mr. W. 
I^ips, arc as follows. 

Mon M' 

120" 30' 

M ofl A 

120 45 

M one 

146 2*2 

A one 

146 10 

C <HI « 

la 12 

* Btrpnmd nllcd ii allutli vq;ctabili- viiriolnluui, oiul Morttnu vitriol of 
t »iaw's Boj^, i. M. 


Not uDcommonly diree of t]i« crj-stala an aggrtrgatpd toother 
»o as to coii§utute a injiole.* 

Sulphate of potash hoH a vrry riisagTeeablc bitter ia»tc. Its 
9])ecific gravity, uccoTdiiig to WnUcriust w 2-298 ; acconUitg 
to Hiu^oiifnitx, 2*407U ;| ncconliiig tti ^^'abM>t^ 2-63t>.} I 
foumi it 2-(J6. At the toin|>cratiiTC of 60° it di.-wolvtn in 16 
timcH its weight of water : in a boiling heat it is soluble in five 
times its wcight.|| When it is boiled in water, that liquid dis- 
solves 0*242 parts, or nearly Jth of its woighl of iH 

It 8ulTeT)) no uileration wlien exposed to ibe air. ^^'h«o 
pUcect upon burning coaU, it decrepitates, but suffent no other 
altontion. In u red heat it melts. It is Mometimeo himiiiuus 
in tlie dark, nx Mr. Giobert has observed.** It contuins do 
witter of cry»l»llizutioii, and is eomposed of 

1 atom Hulphurie acid . . 5 

1 atom potash ... 6 ' 


2, Sesquisulphale of poitm/i. Tliit »alt was obtained by Mr. 
Phillips while evaporating, ilic ri-»i<lual salt remaining after 
distilling a mixture of equal weights of nitre and Hulphtiric acid. 
It isn whit« salt which eryiitallizes in longKlctider needles like 
asbestus. Its taste is .sour ainl bitter, and its consdtui'obs 
according to tlte analysis of Mr. Piullips, are 

Sulphuric acid . . 52-43 

Poiash . . . 42-80 

Mater . . . 4-75 


Thi« i« obviously 

1^ atom sidphuric acid 


1 atom potash 


1 atom water 


9. liisulphate ofpolath. lliis salt is obtained when we mil 
sulphate of potash with lialf its weight of siilpliuric acid, ■>'"' 

• Sec an account of the crjdala of thii Mlt in Annate of PhilOMf^ 
(now serieii), h. 34a. 
■f Chciiiiiii/jr, p. ^&, t Ann. de Chiin. xxi'm. It 

f Chemical Ei>mi>b, v. 67. || Bcrsmtm, i. 133. 

\ Wennt's V«r«iuiiliichiift, p. 310. •• Ann. de Chim. x. Wk 
n Ptiil- Msg. (Sd vena), li !4B. 


expose iiiii mixture to incipient rcdaess in u plaUniim crucible 

till it ccwws to lose acid. When dbsolvcd in wuter, und set 

Slide it cjyMtalliz«8 in thin rIioniboi<Ul plates, tlic |tlanf anfjlos 

<rfU»e large hcea of wliich are 97" 20' and 82" 40', and tlic 

Eiccs of tlie pTum are tiicliniHl to eaeli oilier at angles of 107" 

15'. Its taste li very aicid and »liurp. It melci ea§ily when 

kttted, and flown like un oil. A very strong heal » necesfciry 

to drive off the CXwm of acid, unli-?» we neutrsilixc it liy iiirans 

tf ntiDaiita. It dissolves in about twice its weight of cold, mid 

ia bw tluin its weight of boiling water. Wlicn ulcohol is 

[MNlted into iIk* solution, xulpbate of pota&h precipitates. When 

•ilWttd to the air il effloresces ulightly. The compo^^ilion of 

llili silt was first accitratvly determined by Dr. Wollastoii.* 

li it a compound of 

2 atonu sulphuric add . . 10 

1 atom potash ... 6 

2 atoms water . . . 2*Sd 


4. SitlphiU iif potash. This salt may lio obtained by pa8»ng 

L ' ctLrreiil of sulphuroiu ucid gus through a solution of potaflti 

■ lill tile aliudi Ik- ssitiintted. \\» crystJiU are white an<l traiiH- 

' P«f»iit: tlteir figure that of rhomboidjdpbites. Its crystultixa- 

DbD often presents small needles diverging from a common 

I ffntre.j Its sp«ciJic gravity is l-686.§ Its taste is peuetrating 

•"id sulphureous. At the common temperature of the almos- 

foere it is soluble in 'na own weight of water, but much more 

tolubk in boiling water. When exposed to the air, it smrcely 

tihufos its appearanct', lo«es about 2 per cent, of its weight, 

tad iben is gradiuUly, but very slowly, eonvcrlt-d into sulpluito 

«r potiuh. When exposed to u sudden heat, it decrepitates, 

Lm» itn water, and a portion of itt acid ; then a quantity of 

sulphur is disengageil from tlae re uuuning acid, und tlie residuum 

Is sulphate of pota«b, with a slight excess of alkali. Nitric acid 

eoitverts it into sulpliate of potash by imparting oxygen. .So 

Bdoes dilorine, hut imperfectly, aa it drives off a portion of its 

mM unchanged. 

It ae«m» lu contain no water of crystalUzatiun, but to be a 
conpoond of 

• Phil. Tmn*. leOS, p. M. \ first Princlpln, il. 9M. 

t I'oinvro}' Mid VaiKiuelin, Nidiolion'i Jotiraal, i. 317, 
S llaMcnfraii, Ana< <le Cliiin. xiviii, 12. 


cuh I. 1 atoip sulphurous acid . . 4 

1 atom potash ... 6 


5. Bimlphite of potash. This salt is easily obtaiaed by 
adding an additional dose of sulphurous acid to the last alt 
It crystallizes more readily than sulphite, but has not bwfl 
particularly examined. 

6. HypostUphUe of potash. This salt is easily formed hf 
exposing hydroguretted sulphuret of potash to the atmoq>heM 
till it loses its yellow colour. The liquid is then a aolutin of 
hyposulphite of potash. When sufficiently concenlnted it 
crystallizes in a confused mass of spiculte. The cryitalR nt 
long lectangnlar four-sided prisniB with square basea. It|i4 
a penetrating taste like nitre, succeeded by a bitterness^ and ii 
very deliquescent The deliquiated salt crystallizes in fi» 
needles by a slight diminution of temperature. By (he action 
of a graduated heat it boils down to a dry white mass, then 
takes fire and burns much like a piece of tinder, butwiliii 
weak blue Same. It dissolves chloride of silver, even when 
very dilute, with great readiness.* 

When a saturated solution of sulphuret of potasnnm in ako- 
hot is set aside in an uncorked phml, beautiful crystals of tlui 
salt are gradually depoated.f 

7. HyposvlpfKiie of potash. This salt crystallizes in eyfis' 
droidal prisms, terminated by a plane perpendicular to tbar 
axis;l or in dodecahedrons composed of two six-sided pyn- 
mids, applied base to base. The figure of the crystal Is Twy 
minutely described by M. Heeren.^ It dissolves in LSSpnb 
of boiling and in 16*5 parts of cold water. Itcontains nomtff 
of crystallization ; but is composed of 

1 atom hyposulphuric acid . . 

1 atom potash .... 6 


nwoiT. 8- titrate qf potash. As this salt, known also by the nuse 

of saOpeIre, is produced naturally in considerable quantities 
particularly in Egypt, it b highly prot>ab)e that the ancieiiK 
were acquainted with it : but scarcely any thing certain o" 
be collected from their writings. If Pliny mentions it at A 

• Ilertchell ; Edin. Phil. Jour. i. 10. f Berzetiut. 

% Annals of Philosophy, xiv. 3U. S PoggendtHf s ADDBleii,Tii-^ 

I Uccren, Ibid. j). 16- 


e CDnfounds i( with carlionate of sotla, wliidi was kitown by 
he name of aitroK aiid NUrum. It in ccrtiun, iiowvvor, thut it 
M been known in titc Eiut from tiini^ imnivmoriiJ. Iloger 
kcoa mentions this salt in the imk century nndrr the name 
i mitre. Tbe word nitre {nitrum) wiis u[i|ilit-<t by tlicuncicnta 
• carbonate of soda. W'tien nilrate of |>olasli wastirst oiMerved 
t iwubftbly got tlie same name, from the supposition tliat U waa 
be suni^ kiiiil »f salt. After t)ie difTerencc became known tW 
ana niln vsm naturally apiilied, exdtuively to tliv ino«t 
npotttut of the two, wtiieli ifi unquestionably wtltpotrc. 

No phenomenon bua cxcitvd the attenlinn of chcnuod [>I>i- 
DSOplian moro tluui tJiv continual reproduction of nitre in 
artain pbiccs after it had been extracted fnini tliem. Prodi* 
jMUi quantities of Uiis sail are necessary for the purposes of 

t{ and ta tuiture has not laid up great magazines of it, as 
Ini of «onie otiier HdtiS tliiH niiiniiil rt^production is the only 
puree from whicb it eaii be procured. It iit't'ame, therefore, 
■ tbe utmost conscqncncv, if possible, to disoovcr the muuu 
Mkioh nature employed in forming it, in order to enable nn to 
pitate ber processes by art, or at least to accelerate and facili- 
tliem at pleasure. Numerous attempts accordiugly have 
to explain and to imitate these processes, 
setting out on the [irinciple that there is only one 
in luitnre, Bupposed that nilrio acid is merely sulphuric 
combined with phlogiston, and that this combination i» 
uced by putrefaction ; he affirmed, accordingly, tluit nitre 
by unituig togetlu-r potasli, sulphuric acH), and 
But this opinion, which was merely supported by 
far-fetched analogies, could not stand the le^t of a rigor- 
oxaini nation, 
turnery, the younger, accordingly advanced another, affir- 
aing, tliat all tlie nitre obtained cxi-ttt ])reviously in atiimals 
■hI vegetables, and tkit it is furnu'd in these substuiic^it by the 
ppceMes of vegetation ainl unimalizatiun. But it was soon 
fisoovcrvd that iiitro exists, and is actiudly fonnvd, iu numy 
>laeeK where no animal nor vcgetubie suixttanoti luut l>eeu 
lecomposed : nn<l conaequently titis tlivory was as untenable 

ttbe former. So liir indeed is it from W-ing true, tlmt nitre 
formed by tliese processes alone, that the quantity of nitre 
in plants liaa been found to depend entirely o» lite soil in which 
y grow." 

At last, by the numerous experiments of several I-'rciuili 
* Bouillon. 






cfc**- pluknophen, paiticnlarly by diose of Honvenel, h wu £s- 
covered that nothing else is necessary for the production of 
nitre but a basis of lime, beat, and an open, but not too free 
communication with dry atmospheric air. When these cii- 
cumslances cmnbine, the acid is first fonned, and afterward 
the alkali makes its appearance. How the air furnishes mafe- 
liais for this production is easily explained, now that the com- 
ponent parts of the nitric acid are known to be oxygen and 
note : but how lime contributes to their union it is not so easy 
to see. The appearance of the potash is equally extraordinary. 

Nitre is found abundantly on the suiface of the earth in 
In^a, South Africa, and even in some parts of Spain. In 
Germany and Fiance it is obtained by means of artifidal 
nitn beds. These consist of the refuse <^ animal and veget* 
able bodies undeigoing putre&ction, mixed with calcare- 
ous and other earths. It has been ascertained, that if oxygoi 
gas be presented to azote at the instant of its disengagement^ 
nitric acid is formed. This seems to explain the orig^ of the 
add in these beds. The azote disengaged from these putjefy- 
ing animal substances combines with the oxygen of the air> 
Tbe potash is probably furnished, partly, at least, by the Teg^ 
tables and the soiL 

The mtxe is extracted from these beds by lixiriatii^ the 
earthy matters with water. Thb water, when suffidently 
impregnated, is evaporated, and a brown-coloured salt obtained 
known by the name of cnide nitrt. It consists of nitre, Gom- 
noD salt, nitrate of lime, and various other salts. The ftneigo 
salts are either separated by repeated crystallizations, or by 
washing the salt repeatedly with small quantities of wata; ftr 
the foreign salts being more soluble are taken up first. 

Nitre, when slowly evaporated, is obtained in six-«ided 
prisms, terminated by six-sided pyramids; but for most pur- 
poses it is preferred in an irregular mass, because in that >tite - 
it contains less water. The primitive form of its crystdi^ 
according to Haiiy, is a rectangular octahedron, composed (^ 
two four-sided pyramids applied base to base ,* two of the sidf* 
are inclined to the other pyramid at the angle of 120 ; tk 
other two at an angle of 111°. The six-sided prism is tbe 
most common form which it assumes. Sometimes, insteoi (■ 
six-sided pyramids, these prisms are terminated by 18 fece^ 
tliKposcd ill three ranges of six, as if three truncated pytamii 
wore piled on each other ; sometimes it crystallizes in t^l»* 
• Traile de Mincralogie, ii. 346. 




Tbc spMJfic graviiy of nitre, as ascertained by Dr. Wat- 
ton, n l-93;l," Ita Ijwtc is sbarp, bitterisJi, and cooling. It is 
wry brittle. 
100 p»rt» of «iit*r at 32" dL-solve I3-32 of this wilt. 
At 4I''-0I8, 100 Wi»t«r diMolvo I6-7'2 parts 
53 2i!-23 

64 J 29-31 

7fi-0 38-40 

95| 5482 

1 13} ?4-«6 

130 J 97'05 

149-a I2,V42 

17fti Ifi»-27 

207-a 23S-45+ 

Alrohnl, of the specific pravity 'STS, dissolves -rijjtJi of its 
*n|;hi (if tlii.t Halt, liul HtTu:i|;cr alcohol takes np no ttenaible 
pwtion of it. I It w not altered by exposure to the air. 

When th<- Mlution of nitri; is exposed to a boiling heat, part 

df tli« salt m cvapornted along with the water, as Walleriits, 

Kinntn, and Lavoisier observed »ucces.sively. When exposi-d 

>■> a Ktrong heat it melts, and congenU by cooling into an opaque 

Dim, which lias been calleil minenti rryntuf. When lieatwl 

umity to OKliiess it begins to ili.sengago oxygen ; and by kee|j- 

tag it in a red heat, about the third of ita weight of that gas 

nay be obtained ; towards the end of tlie process azotic gas is 

gaged. If the heal be continued long enough, tlie salt is 

oipletely decomposed, and pure potash remains behind, 

iVheii ttimply brongiit into fusion, and then allowed to cool, it 

umc* a radiated texture. The hroiuler these radii are tlie 

urer is the salt. A mutture of about j'^th of common salt 

completely destroj-s tlic radiated appearance. 

It detonates mure violently with combustible bmlies than 
y of (he other nilnites. When mixed with one-third jiort of 
weight of charcoal, and thrown into a red-hot crucible, or 
when cbarcoul is ilirown into red-hot nitre, detonation takes 
place, and one of the mo«t bnlliaut combuntioiH tliat can b« 
exhibited. The residuum is carbonate of potusb. It wiw for- 
merly culled nilrtjitedbjf eharcval. The alehymisls performed 
Uila cxpcrtDirnt in a tubulated curtLva retort, to which an 

* IlMajw, T. «7, WsUeriu* nnket it )-!XH) (Chcmiilry, p. 260) ; Ita»ien< 
NU bund il I'MOD (Ann. du Ciiim. ixviii. IS.); I'uliruu licit bad sUicd it 
■ lniiK«gau l7!4atS'tA0(i>hil. Traiu. xxxTii. Ill)i Ifouodit^^ 

1 Oay-LutMc ; Aniiala of PhiloMjihjr, xv. 1 1- | Kkwuu. 



°— >- appantat of glass venek was luted. After every portian of 
nitre and darcoal whicb tliey threw in, they abut iq> the retocL 
The cariMHiic acid aod azotic gas which were disengaged often 
baist their apparatus. To the small qoaoti^ rf vater iriud 
they obtained in their veasels, they gave the name of efyatMt, 
and ascribed to it a great many virtues. A still otore TiolenI 
detonation is produced by using phospborns instead of charccaL 
When a mixture <^ nitre and phosphorus is struck smartly iridi 
a hot hammer, a very violent detonation is produced.* 
F^h jtint When three ports of nitre, two parts of dry potash, and one 
part of sulphur are triturated together in a mortar, a powder ii 
formed, whidi was known more than a century ago, and dis- 
tinguished by the name oi fulminating powder. When heated 
gradually till it enters into fusion, it takes fire suddenly and 
boms with a violent explouon. By the fusion sulphuret <A 
potassium is formed, which being intimately mixed with (he 
nitre, and the heat by, the fusion being rendered eqnabla 
throughout the mass, the whole bums at the same instant 
Hence the reason of the violence of the explouon- 

Nitre contains no water of crystallization, but there are often 
cavities in which that liquid is mechanically lodged. Suppoi- 
ing it pure its constituents are 

1 atom nitric acid , . 6'75 

1 atom potash ... 6 


Nitre furnishes all the nitric acid in all its states employed 
either by chemists or artists. When burnt with tartar it yields 
a pure carbonate of potash. In the assaying of nrions ores 
it ia indispensable, and is equally necessary in the analysisflf 
many vegetable and animal substances. But one of the BMlt 
ogninwdn. important compounds formed by means of nitre is gunptmief, 
which has completely changed the modem art of war. IV 
discoverer of this compound, and the person who fiist though 
of applying it to the purposes of war are unknown. It is en- 
lain, however, that it was used in the 14th century. I^on 
certain archives quoted by Wiegleb, it appears that caniwsn 
were employed in Germany before the year 1372. No tnccs 
of it can be found in any Kuropean author previous to the 18d> 
century ; but it seems to have been known to the Chinese 
long before that period. There is reason to beUeve that cw- 
nons were used in the battle of Cressy, which was fought in 
• fimgnatelli ; Add. de Chim. xsvU. 74. 


1346. Titey Mem even to liave been used tliree years (?arlier 
I tt (he sicgt- uf Algpsiras ; but before lliis time tliey roust have 
been kuowu ta Gennany, as tlivro is a piece of orditaiice al 
Ambcrg, on wliicb ia iuscribeii ihi- y«ir liHiS. RoRCr Bacon, 
who tlied in 1292, know tdc pro|HTlics of Kuiipowdcr; but it 
dott Dot follow tliat lie uiu «L-(|Uuinti'(l wiUi its applivutiou to 
fin^nuL' . . 

Gunpowdrr ix composed of nitre, sulpliur, ami cliarcoal, 
Rducetl to powder, and mised iiitiniateiy witli eacti uthk-r. 
Tie proportion of tbo tDgredtentl varies very considerably ; but 
gwdg^ipowder may be composed of tbc following proportions-f 
7(i parte niln; 
15 chaicoal 



Ane ingredientii are fir^t rtxluccd to a fine powder, ticpa- 
ntely, tbeii mixed intimately, und funned into a thick paste 
>^tb vmttT. Afd'r tliis has dried a little, it U placed (i])ou a 
■■■nil uf sieve full of Email holes, through which it is foreed. 
^y that proccas it is divided into ^ainit, the nhe of whicit 
^tpeiiiis opoii Uie size of the holes lhron|j;h which they have 
Iwii Bqucexed. Tlie powder, when <lry, is put into liiirrchi, 
wkicli are made to turn round on tlicir axes. By tliia moliwij 
w grains of gnnpowh'r rub agnin.4t each other, their a^eri- 
Ml ve worn olT, und their surfaces are made smootli. The 
pMrilirr ii tlieii Ku><f to he j^luzed. 

(iiiniiowdi'r, as is well knouii, explodes violently when a miamn. 

fed lieat is applied to it. Tliis oombuHtion takes place even 

In a vacuum; a vast quanlily of gas is emitted, the sndden 

inductioo of which is the cause of all the violent effects 

whith thia Bukilance produces. The combustion is evidently 

wing to ibc decompo&ilion of tlie nitre by tlic charcoal and 

•ul(»hur. 'J'he pnxluclA are carbonic acid gas, azotic gas, sul- 

pliurouH acid giu, and ])ruhiibly sulphuretted hydrogen. Mr, 

Cnitckabanlui luu aicerlaincd lliat no perceptible quantity of 

mtor is formeil. What remains after the combustion is potash 

■Mnblncd with a smidl portion of carbonic acid, sulpliate of 

B ■ Sec WsUod'a Oliemical Umyt, Vol. L 327. for b full dcinil of the fscLi 
^BnpMling llin ■nbjcci. Frocit Harbour's Lire of Robert Briicr, Jt apgiton 
^pkM guM vcrc uMxl by tlie En^litrti (or the first limo about ihe jcor 1380. 
B f For • ftill iktHtl of every tiling retpecdng th« pro|>ortloiis and numu- 
bctorc of gunpowder, the roidr-r jh rvfcrrvil to o wry intcrMting iliu>cn«tion 
by Dr. WiUon, Euajs, ti. t, aud Cu Uuuiuc'b Clicuii^ir), 1. 466. 


potasht n very tunall proportion of itulphuret of potnsuum. and 
micuiDiuiiicd L-liarcoiil." TliU mixturt^ kioou atlracte moisture, 
imd tlxc Hiilphurrt wliivk it contuins ciiuttlcH It to act strongly vo 
metallic bodies. 

A mUture of r<]iml parts of tartar and nitrtr, deflagrated in 
a crucible, U known by tlie name of wiite flux. It is merelj' 
a mixture of cnrboimte of potasb u-itb wme pure potaHli. Wfaea 
two parts of tartar aiid one of iiiir« are deflagrated in tlii* 
manner, tlie residtiura is called hhrk fttu: from itM colour. It 
Is mi^rely a mixture of cluircoal and carbonxtv of potusb. 

9. Hffponitritr o/ piitush. 'I'lii» salt may be obtained by 
decomposing liypoiiitritc of Icud by mrbonatc of potaah, or by 
keeping nitre in fusion till the disengagement of oxygen gM 
without any augmcntatioi] of temperature ceases. The sail i> 
then allowed to cool and diMolvedin w^ter. The first crystal* 
that are deposited are usually of nitrate of potasli ; tlicii the 
hyponi trite makes its appearance, 'iltissalt contains no w^al«~ 
of cryntallir^tJon, but h conipoM^d of 

1 atom hyptmitrous avid . 4-75 
1 atom potititli . . . d 

lO. Chlorate of potash. This salt was discovered by B«r- 
thi^et,f and liaa been very much investigated by cEicmUtx in 

It h prejiared by dissolving one part of cnrbonatc of potuli 
in six parLi of wau-r, putting the mixture into a Woolfe's bottle, 
and •atunittiig the potash u-ith chlorine ga;i4 When the 
Mtaiation 'n netirly completed, the eblorale fidU ilowii in cryii- 
tile. It may be purified by M)lution in boiling water. Asthe 
WKtcr cool**, the pure chlorate cry Ala) I i):e«. The crystals arc to 
be dried between folds of blotting paper. 

According to Ilaiiy, tlie primitive form of tlie crj-stak of 
chlorate of puiath i.i an obtuiti^ rhomboidal prism; but it it 
amdly ubljuned in small tliin pUtesof a silvery whiteness. It 
Is only by allowing on uiisaturated solution of it in boiling 

• Crvlckshanin, Nlcbobon'ti Journnl, iv. 2^8. 

t It wu. b bet, Sm di»cui-i'ri;d l>y Dr. Ui^ns, iriio nWMtiaiH it bl< 
ITSC; bill a[ij>c!ark to hart mutAhcn It br nitre. See Higgiai oo AoilMn 
AciJ.&c. p. IKO- 

t Tlic bottle conlniiiing the alkali niii^t be covered up fraut the llg|A>, 
otherwise no cr)-«tBU of clilorate can be oblaincd, w 1 have mora tb«a 
ODCe n|)«r!enccd. 

water to cool slowly, or by exposing n solution in cold water *«•■ 'i- 
to !^>ontani>«us evaporation, tliat it in obUiiuecl in large regular 
ihomboHluI crystal 

lift tksto is cooling, aii>tf re, and diMi^rovuhle, somrwhat ana- 
logoiM to that of nitre, It« sjn'i-ific gravity is l-»89.' Its 
wlulHlity ill wnt«r, iw tletenniiinl by Ouy-Lutwoc, isas f<^loW8 : 

.■J2», 100 water dissolvos O-O-l of tlie salt 
56 5-6 

59j 6-«3 

76 8-44 

95 12-05 

122( 18-96 

166-d i)5--10 

220-6 60-24t 

« il not sensibly altered by exposure to the air. If the heat 
Wniwd to redness, it rapidly gives out more than the tliiwl 
<* iu weight of oxygen gas. It is from this salt that oxygon 
(M caji I»e ohtiiined iii tlic stat« of the gtwitesl purity. After 
•i» eSnvMcence fa over, there remains common chloride of 

The most astonishing of its properties arc tliose which it 
'tMliits when mixed n-ith combustihles. All eointiuHtiblc sul>- 
'lances wltalever are capable of decomposing it, and in general 
lir decomposition is attended n-ith violent detonations. 

When three parts of this salt and one part of sulphur are n>rtiutAD 
njttimtfd in a mortar, the mixture detonates violently: the 
■ne elTcct is produced when the mixture is placed upon ait 
tnril and struck smartly witli a hammer. Nay, it even some- 
liii»es detonateo spontunooiuly without any perceptible friction, 
ud ouglit not ihcrcforc to be kept n^ady mixc<l. Cluircoal 
produce* tlic same effects, though not so violent. This pro- 
perly induced Bertbollet to propose it ns n substitute for nitre 
In the preparation of gunpowder. The attempt was made at 
Emme in 1786; but no sooner liad the workmen begun to 
triluret« tlie mixture of charcoal, sulphur, and chlorate, than it 
exploded with violence, and proved foral to Mr. Lelors and 
Mademoiselle Clierraud. Tlie force of this gunpowder when 
it ia prepared, is greater than tliat of the common sort of pow- 
der ; but the <langer of preparing it, and even of using it after 

* HMMofrau. Ann. cle Chmt. XKviii. It. 
f Aauls of Philou{ilijr, xv. 1 1. 



""'• it is prepared, is so g;i«at, diat it can hat^f ewr be Bnbstitntcd 

with adnmtage for common gunpowder. 

Pliosphonis also detonates with this salt either by tritaration 
or percuasion. The quantities ofeach used ought not to exceed 
half a grab, or at most a grain, otherwise the experiment maj 
be attended with some danger. It detonates also when treated 
in the same way with almost all the metals, and likewise wiUi 
cinnabar, pyrites, sugar, gums, oils, alcohol, &c. Wlien thrown 
upon platinum heated to whiteness, it does not detonate bnt 
sublimes. The sur&ce of the platinum, however, is oxidized; 
for acetic acid dissolves a part of it ; and when pnustate of lime 
is poured into the solution, the liquid becomes of a greenish 
white colour.* When thb salt is triturated in a mortar widi 
a little cotton cloth, small repeated explosions are heard, similar 
to the crack of a whip, and if the cotton be dry and warm it 
sometimes takes fire. It always does so when, after the trv 
turation has been continued for some time, Bulphuric acid is 
poured upon the cotton. When nitric acid is poured upon a 
mixture of chlorate of potash and phosphorus, fiakes of fire are 
emitted at intervals for a considerable time.f 

The theory of these explosions was first pointed out by 
BertfaoUet. The oxygen of the acid combines with the com- 
bustible, and at the same time lets go a quantity of caloric ; and. 
trituration or percussion acts merely by bringing the particles 
which combine within the sphere of each other's attraction. 

When this salt is heated to incipient ignition it gives out 
oxygen gas in abundance, and chloride of potassium remaiuL 
In this way it has been analyzed, and shown to be a con- 
pound of 

I atom chloric acid , , 9'5 
1 atom potash ... 6 


Advantage has been taken of the properties of this salt ta 
Hucbct. make matches, which take fire when dipped into sotphuria 
acid. Thirty parts of the salt in fine powder are intimatety 
mixed with ten parts of levigated sulphur, 8 parts of sugar, 6 
of gum arable, and a sufiicient quantity of cinnabar, to give the 
whole a red colour. The sugar, gum, and salt, are firatmized 
iutimateiy, then water enough is added to bring the whole to 
the consistence of thick cream. Lastly, the sulphur is added, 

* MorvcBu, Add. tie Chim. xxv. 18. f Collier, Mancheater Mem. v. sm 



ind tlie wliolc well kneailcfl together. Matebf 8 iilrpikly coated 8«*-i 
with flolphur arc dipped into this matter, and ihua coated over 
with a thill cnist of the mixture and allowed to dry. W'lifin 
Ane matebe« art' dippi-d into Kulphuric add I.liey kiiiilic imd 
M fire to lli« sulphur, and thus may be employed to light a 

What is called percussion powder, is merely a giuipowder 
In vhich chlorate ofpotadi la siilMlituted for nitre. A little of 
■■ ii put intA a thin copper thiinhle. When struck it eutchos 
Sreand explodes the powder in the piece. 

It. Brvmnle of potath. Thiu salt is obtained when bromine 
M dMwIvcd in caustic poliisli ley. It precipitates a* it forms 
in iLe state of a white powder. It is little soluble in cold 
*at«. hut much more noliiMe in boiling water, and as tlii» 
folutioii cools it is <b>positcd in needles or crystalline plates, 
^Ticii heated it behaves like chlorate of potash.* It has not 
■•^eti rijforously nnaiyzcd, but from the cxpcrimontt of Balard 
lut^-rc can be little doubt thnt it is a compound of 

I atom bromic acid . . 16 
1 atMD polasli ... A 


VZ, lodafc of potash. TTie ensient moiie of forminff this sail 

I IIId pasd a current of chlorine gas thnni);h iodine rill a com- 

WlatioD is formctl, M'liich is to be saturated n ith caustic pota>ih. 

lodate of pntaxh precipitates, while chloride of potassium 

MiHiin« in Mtlulion. The iml»le is to be dissolved in boitin^r 

liter and set aside to crystalline, Iw crystal!* are so wnall 

ttat tlieir fignre has not lutherto been aicertulncd. 'HiIs salt 

ii not altered by exposure to the air. One Ittnidred pFirts of 

1i-al«rat 57"^ dissolve 7*48 parts of this salt- Wlieu Lented 

bt mlness, oxy^n gas is dtsi-n^igi'd and iodide of potamum 

■ remains : on burning conis it fuses and dcfln^tes like iiltrcf 

f-l part of this salt at 57° ditaolves in 13-4.i j>art* of water. It 

is insoluble in alcohol. Sulphuric acid dissolves It when 

awtsted by heat, without decomposing it. 100 parts of tliis 

mlt when healed to redness give out about 23^ of oxygen gas. 

he constituents arc 

* Balnrtl, Ann. dc Chim. et de Phys. xxxii. 30d. 
f Gay'LiuiBc, Ann. He Chim. xci. 74. 


""'■ 1 atom iodic acid . . 20-76- 

1 atom potash . . 6 



There exists a disiodate of potash which cry Btallizes, but bv 
not been hitherto accurately examined. 

13. Carbonate of potaek. This salt has been long known to 
<^emist8 ; and before its composition was ascertcuned by Bladi' 
it was characterized by a great variety of names, according ts 
the manner of preparing it ; such as Jiaxd nitre, sait (^ tartar, 
vegetable <Ukali, &c. Its properties were first described with 
precision by Bei^an in i774.» 

The pearl ash of commerce is a carbonate, but very mncb 
mixed with foreign substances. It may be freed from the 
greater number of these foreign bodies by pouring on it ite ow^ 
weight of water and allowing the whole to remain for 24 hour* 
under occasional agitation. The water b then decanted of* 
and evaporated to dryness. Most of the foreign salts remal<* 
nndissolved. The salt thus purified is sold by apothecaries 
under the name of salt of tartar. It is still too imparl 
for chemical purposes. Pure carbonate of potash may b^^ 
obtuned by heating bicarbonate of potash, or by burning pur^ 
cream of tartar or a mixture of equal parts of cream of tarta^" 
and nitre, and dissolving the residue in water and evaporatiii^' 
the solution. When the solution is concentrated till its gpc 
cific gravity is 1'62, and then put into a tall cylindrical ^aatf 
vessel and left to cool slowly, it deposites crystals which hav^ 
the form of rhomboidal plates, and which speedily deliqoeace* 
when exposed to the air.f The primary form of the cry^ a* 
an octahedron with a rhombic base, the angles of tbe rhoab 
are laS" and 58°. 

Carbonate of potash, thus obtained, is a white salt haring » 
strong alkaline taste, but not caustic It changes vegetable 
blues to green, and deliquesces rapidly when exposed to ite 
air. It is insoluble in alcohol, but very soluble in wBier. It 
is composed of 

1 atom carbonic acid . . 2-76 

1 atom potash ... 6 

2 atoms water . . . 3*25 


• OpuM. i. 13. t Fabroni, Add. de Chim. et de Pbyt. utr. &■ 


sb of commerce is alu-aya in the stale of a carbonate; 
but il cotitsiru likvwute tieveral foreign Aubstaneeii whidi rt^iidcr 
tke proportion of ulkitli vuriaMo. Mr. Kinviiii luw puiiib-d 
Mt a very in|^cnioiii> nKitbotl of detecting itio quiintity of alkali 
in any specimen, by the pn^erty wliicli it luis of precipitating 
kluuiiui from alum ; and Vauquelin Iiaa published a Nlill simpler 
WHbod, iioini'ly, tlte quantity of nitrie acid of a given density 
ry to saturate u friven weight of the »Hilt. From his 
tnto, we learn that the following kinds of this saltluiowa 
in commerce contain the following ingredienta :* 

Potnsh of ItuH^ia 


American Pcarl-asti 

Potusk of Treres 
































im 1152 

004 1152 

»04 1440 

SUil simpler and more aeeurate methods of determining the 

V**rity of these bodies Lave been contrived by DeeroiziUe and 

*>vy-Lu9sae. But it seeniH scarcely necessary to point out 

■>e»e methods, a» tlie use of potash in tliis country is dimin- 

■Wng ver)' rajitdly, carbonate of soda being gradually taking 

1^ place. And tliis last alkali is prepared by our manufiictUTera 

l*> a Mate approaching so nearly to purity, that there is seldom 

Wdflioo for testing it. 

14. liiearbonule oj'jiofa*h. Tliis salt is formed by saturating 
pMaah with carbonic acid, which iK bent done by causing the 
pa to pan through a wlution of potash til) it refuses to absorb 

tany more. The potiwh of commerce is nii impure carbonate 
af potaab : by distilling it with solid carbonate of lunmonia, it 
may be converted into bicarbonate of ]>ota)di.t Whei] potash 

SRt. n. 

• Aon. de Chini. xL 2i& 



t BcnhollM. 



in titan sattirated witli caibaitic acid, it aln'a^'s Ipts fall & quundty 
of silicti. Mr. Pelletier lias prupoRcil tli» jtatumlioi) att Ui« lie&t 
mothud of purifyinfr ]i«bL>li fr»in tlio eanb. 

'i'lir primary form of tlie crystal i» » ri^t 
oblique prJifii), the faces of whicli mvtt at 
aagles of 100° 25'. The figurv in the miuf^n 
represents tlie most common secondary form 
(<-XLi-pl lliat tlie face T b usually n-sntin^), 
imd the foUowiit); ure the measure men tM of | 
angles by Mr. Brooke:* 
M on a plane parallel to/ . . 
M on f 



e on/ 
M on d' 
d- oil d' 















This salt baa un alkaline, but not a caustic tiiste, und still 
giveJB a yreen folour to vegetable blues. Its sjieeific grarity'' 
is S-OlQ.f It is soluble at the common temperature in iiboufc 
four times its weiglil of wat«r.:t Boiling water dissolres |tii# 
of its weiglit.} Alcohol, e.veu when hot, does not dtssolvf? 
above ■j-i'oo''' P'"'' °^ ''• l*vl''"tie'" hiw ob»i>rvi-d, tJmi when die^ 
crj'stallized salt is dissolved in boiling n'ater, bubblnt of car 
bonic acid gas are emitted. It is not altered by exposnre to 
the air. Heal deprives it of its water and part of its acid, buC 
does not decompose it eomjiletely. 

Ur. WoUaston first deuionittrated lliat this wit contains twice 
M muck carbonic acid as tlie preceding. The water which it 
cootaiiH amounts to very nearly I) utom; but most probably 
the czCMS above one atom is merely loilge<l between tlic pialeo 
of tlic crystals. We may therefore consider the salt as com- 
posed (d* 

2 atoms carbonic acid . . 5-5 

1 atom polo&li ... 6 

1 utom water . . . 1-H& 


15. Staquicarbcmaie t^f potash, I first gotaspeeimen of tUi 
salt from tlie late Dr. Nimmo of Glasgow, wfao had obtaiaal 

* Annalri of lliilotophy (3d >eries) vi. 48. 
-f IIutBcniralJt, Ana. dc Chitn. xxviii. It. 
X OvrffBaa, i. 13. ^ Pelletkr. 



il aociilentally trlUiout he'uig aware of its luttuTo. " Upon *«'■"■ 

Wulyzing U 1 aMwrtaiiic^ its nature. 1( is cuily obtained by 

^ioolving hicurliiiiuitv of potn^ii in water, and boiliiis: tticsolu- 

oon. One-fottrth of tlie carbonic acid is expelled, and, of 

taurec, a sesquicarbonale reroiiins. 'I'be only crystals of it that 

Ihavr obtainedare irregular six-sided plates. Tliey are traiis- 

Incent, and lave nearly tin; »umc ta«tc as the bicarboiiutc. 1 

found iliem compOMil of 

1^ atom carbonic acid . . 4*125 

1 atom potash ... 6 

6 atoms water . . . 6-76 

16. PhtMphate. of potash. This salt may be obbuaed by 
adding carbonate of pota«li to hot pho«plioricadd* tlU thcMti^ 
<i*a c«ise§ to produce any cifcct upon regetable blues. When 
ihiK solution iM nufficiently concentrated, and set aside in a dry 
(■W ii gniditally <lopoaile« phosphate of poUb^h iit Hfnall tran.'^ 
pwni cryHlali*. These crystals are four-sidvd prisms termi- 
"■•td by four-«ided pyruniiiis. 'ITte «iU* of the prism are all 
*S<Blt and its angles right angles. Homctiines the intervening 
prim w wanting so that the crystals have the form of small 
<MihedroKS. 'IliU »alt has a cooling and soinewbat urinous 
^Ne, but neither Mirang nor disagreeable. It is not altered 
6y etpmurc to tlic air. It is very nolublc in water, and melta 
i*t(i 4 U(|uid when exposed to a red heat While in a state of 
Mito its colour is yellow ; but it i^ain assumes its wliite colour 
<B GDolisg. I consider it as coropowd of 

1 atom phosphoric acid . 4-5 

I atom potash ... 6 

1 atom water . . . MS5 

1 1-625 
the atulysis would rc<inire repetition. The crystals of 
InJt ar<- so difficult to procure, that in most chemical liooks 
t il described as uncryKtal livable. 
17. liifAogpknte of potafA. This suit is easily obtained by 
adiling carbonate of potasli to phoephorte acid, till litmuM paper 
reAlrniNl hy it rOHumes iw blue colour when dried in the nir. 
The Kidt shoots into large crystuU when the liquid is con- 
c«ntrated to the requisite pcnnL 'Hie primary form of tlie 
cryalal is a right square pri*in. Two opposite face* oi tlie 
^nuiva are often much enLorged ut the expense of the two utherv. 


■ ■e pri^H H HBBijr ** ' ■>'"**" by & RMtr-ndcd pynmd wUdi 
t fi e q aendr truaated.' It has a vliiw and coolii^ tast^ 
leadDf in ««ter; bat is insolnUe in alcohd. Its 
as deteimined by tbe experiments of BCtdierHd 

3 atons pbosphoric acid 9 

1 aton potash ... 6 

Satomwater 2-25 

1& PJ/iotpkate efpola^ Tim salt may be obtnned by 
addii^ bydiate of potash to a solndon of the pho^hate, erap»^ 
latii^ to dryoesB, and removiiig the excess of potash by tie»-- 
hoL This saJt is tasteless and insoluble in cold water, bM.-| 
solnUle in hot vater ; aad it predpitates as tlie solution ooola 
in a gritty powder. It is extremely fiuible ; melting befiir« 
the blow-pipe into a tranq»rent bead, which becomes t^wqnc 
on cooling. It is soluble in nitric, muriatic, and phoephnr^ 
acids: tbe eolations are thick, gludnous, and adhenve. When 
snffidently dilnted, tbe alkalies occasion no predpitate in Iheae 
solndons; but when they aTeconcentiated,aprecipitatei^q>ean 
I contdder this as a compound of 

1 atom phosphoric acid . 4*5 

2 atoms potash ... 12 


A Bul^hosphate of potash, analyzed by Sanssnre, was foond t* 

be a compound of 

Phosphoric arid . , 8-5 

Potash ... 6'd 

This approaches 

1 atom phosphoric acid . . 4'fi 

1 ^ atom potash ... 9 


From this it is probable that there are two snI^)hoapbatet of 

19. PhoaphiU of potash. This salt is incrystaUisable, ddi- 
quescent^ and insoluble in alcohol.§ 

• See Mitcberllch, Ann. de Chim. et de I^ji. xiz. 37a f Bad.p.3ii 
\ Bur la T^etfttion, p. SSI. $ Ihikaf. 

^H^^^^^^™ HALTS or rOTARII, ^^^^^^^ 4S 

f 20. Hgpofthxiphile ({fjiottuA. lliis salt is obbtinrd by boil- »«*■ '"■ 
inj plMMpliorus h\ a potnali ley. It doci not crystallize, but "^^^^ 
bmu II naliiie maiis, soluble in alcohol, and deliqucnciti^ more 
npidly ibaii cbluticU- <>f cfilcitim. In coii^i*<]ui.'iicc of its solu- 
bility ill alcoliol, it is w»ily freed from phoNpliittes or pliosplutes, fl 
wben it Iiappens to contain tbcm.* H 
31. Aruniate of potash. This salt is obtained by neutral- ( 
ini^ anonic add with potash, and evaporating the solution. 

»We otAun an incrystatttxable uUt, which deli(iues<ces in tlie b 

ti^ nadeni Hvrup of violet-i green, but ilae» not alter tlie Jiifii- ^| 

*i<m of turnsole. When beated in a clay crucible, it \» partly ^| 

moverted into a white gluss, and ]iartly changed into urwniutc ^| 

of potiwli. W'lieu mixed witli one-eighth of il« weight of chitr- H 

ntl jKnrder, and iJistilled in a retort, it swells and bubbles up 
Holeotly, evidently in consequence of the disengagement of 
(Whonlc acid gas, an<l at tlie tuune time a (juantity of arsenic 
■ wblimed : the residtinm is merely carbonate of potash and 

ThtlsaltLsacompoiincl of 1 atom of anienic acid and I atom 
0( potBCh. The ]>roportion of water which it contains baa not 
baen dclennine<l. 

22. fii}tar»cmale (^'potash. This salt was first formed by Mac- 
fluer ; and for tliat reason was long distinguished by the name 
of arimticat Htufrei/ mil of Maequer. He obtaiiie«l it by dh^ 
*illbg in a retort a mixture, conttiHting of equal purbt of white 
oxide of anteniv and nitre. After the distillutiun, the white 
'■^le mass, which remained in the retort, was dissolved in hot 
*!U<T iin<l filtered. When properly evaporated, beautiful tran»- 
f^reiit crystals of binarseniate of potash arc obtained. |- 

tScheele first ascertained tlie composition of this salt, by dis- 
veriiig tliat it vrn.t obtjiined by .adding ancuic acid to tlie ar«e- 
ile of |>ota)kh till the soUiiton ci-flncH to alter tb<^ colour of 
^rup of violet!*. It then reildenn the infiution of tiinoiote, and 
. yields by e\-aponitJon fine crj'stals of Mocqiier's neutral salt, 
i Milcherlidi has shown tliat the cr}-stals of this salt have the 
■^une ahape as tltose of liiphu-iphate of potash.] a right square 
B|irigia, usually terminated by finir-Mi<le<) ]>yRunidH, tlie fac«s of 
tbieh are inclined on the corre^ondiag fjices of the prism at 
■i^M of 133° 12'.§ 
TltiB sadt has a saline and cooling taste, somewhat similar to 


> DutoaR. t Mem. IV. I7K. p. 2£3. 

I See also Mr. Brooke, Annali of PIiiUi*<iph7, v. 4S0. 
i Aon, de Cbiia. et <1« Ph)*s. xi>. 'S70. 




that of nitre. It in not altered by exposure to the air. Spe- 
cific ^mrity 2 638. It m»y Iw kt-pt in ft lii-iu. of 550* for a 
GonsidL-rablv tim« without melting or uiuliTgoing any sciKilile 
chsn^e. In a r«d liest it melts aod beooioes as liquid as water, 
'i'lie coDgenletl salt is opaque or outy translucent. Uy litis 
trr-ntinent it locex 7-5 [mt cent- »f itA weigliL 

It is initciluble in akohoL lOOpurt»ufw»ter at the temper- 
ature of 4'2' <li««olvo 19-047 ports of tbin ndt. The specific 
gravity of this solution (at 60°) is 1-1 134. It ix much more 
soluble in hot than in cold water, llenco a satumled solution 
in hot water crystallizett very readily on cooling. I found the 
constituents of this wilt 

Arsenic acid . . 6d'420 

I'otwh . . . •27-074 

Water . . 7-600 


This is Btmost exactly 

3 atoms arsenic acid 

1 atom i^odtsh 

1 j atom water . 



But Mitcherlich obtained nearly 10 per cent, of water of cry 
tallizaUou, which would elevate the water to t«'oatomB.f The 
salt which I analyzed had been in my possession for upwunlv 
of 20 yeara. \A'hGther tliis nti)>:bt not have diiuiiiithed the 
water of crystallization, I cannot wy. ^ 

23. Arttnite of-piAatk. When nrxcnions acid is diasolvec^K^ 
in carbonate of [xjtwh to aaturation, if wc e\-upuratc the solution : 
the acid tepaniCes in octahedral crystals. I'lib does not hi^' 
])en when caustic potash ts employed. Hut tlie solution cannot 
be crystallized. 

94. IWatt of potash. Tliis snit has been very little exam- 
ined. It may be prepared by calcining a mixture of boradc 
acid And nitre. The heat drives off the nitric add, and leaves 
a white saline mns», which, when dissolved in water, yields 
crystals of borate of putjish in rectangular four-sided [trisiM, 
terminated by dihedral summits. It is capable of eombiniflj; 
with an excess of base, and forming a <liboni(c of potash. 

25. SiticaU of itotanh. SlUeu an<l potusli certainly unite 
tof^-tber in various proportions. But these combinations bare 

* AniUkti of Philooitplif, xf . 6K. f Ann, de Chva. c< de Phj«. six. 306. 

not bc«a sufficiently studied to admit of iloscriptlun. Wliuii 
one part of sUica and four parts of hydmtc of potoali arc fused 
ttj^iher, and cooU'd very #lun'ly, pouring off a portion of liquid 
toatter, nftvr it lii» bifptn to solidify round tlie edgen we obtain 
niicate of putaxli in |>raTly crystaU, which ar« composed of 

1 iitoin vilica . , 3 

1 atoin potffili . , 6 

■ IL' 

Tliu silicate is soluble in water, and conAlitiites the liquor 
uArmn of tlie ancients. 

GliuM U uolhiufr eUe tliao a combination of silica with potaAli 

■ Or soda. When there is iiotliing present but silicate of polnsli 
P^ "f XNh the glass is soluble in water. The mixture of silii's