150 BIOGKAPHIES OF SCIENTIFIC MEN 



all ages that preceded it. And yet, applied science is 

 only in the first early dawn of its power. 



Berthelot was quite sure that physics and chemistry 

 would soon solve the problem of aerial navigation, and 

 he significantly remarked that when they do so " custom- 

 houses will fall of themselves." That would be some- 

 thing like a revolution in the world's institutions, but 

 it would be second to the discovery of artificial wheat 

 and meat. 



Although glycerine was discovered by Scheele in 1779, 

 and its formula established by Pelouze in 1836, it was 

 not until 1854 that its true composition was known. 

 This was due to Berthelot, who proved that it is an 

 alcoholic compound capable of interacting with three 

 molecules of such acids as acetic and palmitic. 



In 1860 Berthelot's book, Chimie Organique fondee 

 sur la Synthese, was published. It was the first of its 

 kind, being based entirely on synthesis. His methods 

 were simple and direct. By means of the electric spark, 

 carbon and hydrogen united to form acetylene ; or by 

 the action of electricity on a mixture of hydrogen and 

 carbon monoxide, the same gas is formed ; also by the 

 action of the spark on a mixture of hydrogen with carbon 

 disulphide vapour or cyanogen. The conversion of 

 acetylene into ethyl ene, and the synthesis of alcohol were 

 also important reactions. Acetylene polymerizes, under 

 the influence of the electric spark, into benzene, and 



