SYNTHESIS OF ACETIC ACID. 59 



to doubt our capability of producing all organic principles what- 

 soever in a similar manner. Wohler's artificial production of 

 urea from cyanate of ammonia in 1828, and Pelouze's artificial 

 production of formic from hydrocyanic acid in 1831, were in 

 reality very important pioneering achievements, although cyano- 

 gen and its compounds were at that time known only as products 

 of the decomposition of organic bodies. But in 1845, Kolbe 

 produced acetic acid from carbon by a series of strictly inor- 

 ganic reactions, and thereby laid the foundation of modern syn- 

 thetic chemistry. The successive steps of his process are shown 

 in the following table : 



Acetic Acid Synthesis 

 C S, Carbon disulphide 



C C1 4 Carbon tetrachloride 



C a Cl 4 Tetrachlor-ethylene 



C Z HC1 3 Z Trichlor-acetic acid 



C a H 4 O a Acetic acid 



Disulphide of carbon CS 2 , was first obtained by the combustion 

 of charcoal in sulphur vapour. This compound was next acted 

 upon by chlorine at a high temperature, whereby it was converted 

 into chloride of sulphur and chloride of carbon CC1 4 . Then by 

 transmission through red-hot tubes, this last product was trans- 

 formed, with evolution of chlorine, into the so-called sesqui- 

 chloride of carbon, 2CC] 4 =C1 2 + C 2 C16, and eventually into the 

 so-called bichloride of carbon or tetrachlor-ethylene, C 2 Cl6= 

 C1 2 -f C 2 C1 4 . In the course of his examination of this tetrachlor- 

 ethylene, Kolbe observed that by exposure to chlorine in presence 

 of water, it was decomposed into a mixture of hydrochloric and 

 trichlor-acetie acids, thus : 



Chlor-ethylene Water Chlorine Chlorhydric Chlor-acetic 



C Z C1 4 + 2H,0 + Cl a = 3HC1 + C Z HC1 3 0, 



Then by subjecting this trichlor-acetie acid to the action of 

 nascent hydrogen, he successively converted it into dichlor-acetic 



