LECTURE VII.] HISTORY OF CHEMISTRY. 115 



accomplished operation, which, in so far as accuracy was con- 

 cerned, might be placed alongside of other analyses. A rapid 

 advancement of organic chemistry dates from this period. 

 Since a simple and sure means of determining the composition 

 of the substances was now available, investigations which 

 had not previously been attempted on account of the endless 

 difficulties associated with them, now became possible and 

 were actually carried out. 



No doubt many analyses had already been carried out by 

 the method of Berzelius, and the conviction became more and 

 more settled that the law of multiple proportions was applicable 

 to organic compounds also, and that formulae similar to those 

 assigned to mineral substances could be assigned to them. 

 But an important distinction was still drawn, in the third 

 decade of this century, between these two classes of substances. 

 It was supposed that the latter alone were producible artificially; 

 while the synthesis of the former was wholly beyond our power 

 and was reserved for the living organism, in which it was per- 

 formed under the influence of the Vital Force. From such 

 naturally occurring substances chemists had, it is true, learned 

 to prepare, by dry distillation, by treatment with nitric acid, 

 with alkalies, etc., other substances which were likewise classed 

 amongst organic compounds, but these were, for the most part, 

 simpler in composition, and the material existing in nature 

 always remained the starting point. In this connection, an 

 excellent investigation for that period, by Chevreul, deserves 

 to be mentioned, 15 in which the author showed that the fats 

 consist of an acid and of glycerine (a substance discovered by 

 Scheele), and that they should, accordingly, be placed in the 

 series of ethers, where all those substances were classed which 

 could be separated by means of alkalies into an acid and an 

 indifferent substance (an alcohol). 



This and similar investigations could not, however, shake 

 the belief in a vital force under whose influence all organic 

 compounds originated. As yet no one had succeeded in arti- 



15 Rech. Chim. 



