SYNTHESIS OF ALCOHOL. 89 



oil of vitriol, and upon distilling the diluted acid, is liberated 

 therefrom in the form of alcohol or spirit of wine, thus : 



Ethylene Water Alcohol 



C a H 4 + H,0 = C a H 6 



This production of alcohol from olefiant gas, or ethylene, an 

 important constituent of ordinary coal gas, is undoubtedly, in 

 many points of view, a result of very great interest, but as a 

 step in organic synthe'sis I think its importance has been some- 

 what over estimated alcohol and olefiant gas being closely allied 

 members of the same carbon group. However, Berthelot's dis- 

 covery of a process for obtaining alcohol by purely inorganic 

 means naturally achieved considerable notoriety, and gave a 

 great impetus to the general prosecution of synthetic methods. 



(93.) You observe that artificial alcohol is produced from 

 olefiant gas, which is itself produced from acetylene or klumene, 

 which is itself produced from monocarbon compounds of strictly 

 mineral origin. But a still more interesting way of obtaining 

 acetylene has also been rediscovered and established by Berthelot, 

 namely, the combustion, so to speak, of carbon in hydrogen gas. 

 When charcoal is burnt in oxygen, the heat evolved by the 

 initial combination is more than sufficient to maintain the com- 

 bustion, and accordingly the piece of charcoal when once ignited 

 continues to burn. But in the combustion of charcoal in 

 hydrogen, if it may so be called, the piece of charcoal has to be 

 maintained throughout in an intense state of ignition by means 

 of the electric arc. "When, for instance, the charcoal terminals 

 of a moderately powerful battery, enclosed in a globe through 

 which a current of dry hydrogen is passing, are approximated to 

 each other so as to become ignited, as in the ordinary electric 

 lamp, the hydrogen and ignited carbon combine with one another 

 to form hydride of carbon or acetylene, much in the same 

 way that oxygen and ignited carbon combine with one another 

 to form oxide of carbon or carb-anhydride. But oxidation tends 

 to the separation, hydrogenation to the conjunction of carbon 

 atoms ; and accordingly, while by the combustion of charcoal in 



