0. G. Williams on Organic Substances. 329 
The speaker then proceeded to enumerate some of the prin- 
cipal instances where substances originally derived from animals 
or vegetables had been formed synthetically. W06hler’s synthe- 
sis of urea was shown to be one of the earliest in point of date, 
and his method was described, and also Kolbe’s new process by 
the mere heating of ammonic carbonate to a point just below 
that at which urea is decomposed. 
One of the next most important steps in the history of 
synthesis was shown to be the conversion of carbonie disulphid 
into carbonic tetrachlorid or perchlorinated marsh gas. _Inas- 
much as carbonic disulphid is a purely inorganic body, it is evi- 
dent that any substance which can be formed from it is a case 
of true synthesis, i 
Ths following equations represent the — by which acetic 
acid may be produced from carbonic disulphid :—* 
CS, + 6Cl, = CCl, + 2(SCI,) 
kere ii iS 
disalphia tebrachtonla, tetrachlond 
2(CCl,) = O,Cl, + 2Cl, 
eS ee 
Carbonic Carbonic 
tetrachlorid. dichlorid. 
C,Cr, + Cl, = C,Cl, 
— 
Carbonic dichlorid. Carbonic trichlorid. 
C,Cl, + 2(H,0) = C,HCI1,0, + 3(HCl) 
ee 
Carbonic trichlorid. Trichloracetic acid. 
C,HCI,0, + 3H, = 0,H,0, + 3HCl 
ee“ —_ 
Trichloracetic acid. Acetic acid. 
a This important series of reactions, then, result in the pro- 
ction of acetic acid, one of the most marked of the so-called 
Mere distillation, yields formic acid, the synthesis of the first 
“T leads directly to a new synthesis of the second. sik oe 
’ he other modes of effecting the synthesis of formic acid 
| Ns then pointed out, viz :—Berthelot’s process, which consist 
: heating potassic hydrate in an atmosphere of carbonic oxyd; 
aa Kolbe and Schmidt’s methods, by exposing potassium to & 
— atmosphere of carbonic anhydrid 
si SAM GS Sele gi nie gt a eI el SD es aia... 
FUMES rite Gael > Mie ee 
RS et, a ao 
off Speaker, in the course of his remarks on the constitution 
neg acid, showed that the quantity of oxygen In It was So 
‘ge that it only required one atom more to convert it into 
“atbonic acid and water. Its easy oxydation was illustrated by 
[* C=12, O=16, S=32, ete] 
