S88 CHEMICAL TRANSFORMATIONS. 



the elements of one complex compound, by which new com- 

 pounds are produced with or without the assistance of the ele- 

 ments of water. In the products newly formed in this manner, 

 either the same proportions of those component parts which 

 were contained in the matter before transformation are found, 

 or with them an excess, consisting of the constituents of water 

 which had assisted in promoting the disunion of the elements. 



The second kind of transformations consists of the transposi- 

 tions of the atoms of two or more complex compounds, by which 

 the elements of both arrange themselves mutually into new pro- 

 ducts, with or without the co-operation of the elements of water. 

 In this kind of transformations, the new products contain the sum 

 of the constituents of all the compounds which had taken a part 

 in the decomposition. 



The first kind of decomposition characterizes the proper fer- 

 mentation ; the other, that which is called putrefaction. We shall, 

 in the following pages, use these terms invariably for these two 

 kinds of metamorphosis, which are essentially different in their 

 results. 



