300 CHEMICAL TRANSFORMATIONS. 



CHAPTER III. 



FERMENTATION AND PUTREFACTION. 



Several bodies appear to enter spontaneously into 

 the states of fermentation and putrefaction, particu- 

 larly such as contain nitrogen or azotized substan- 

 ces. Now, it is very remarkable, that very small, 

 quantities of these substances, in a state of fermenta- 

 tion or putrefaction, possess the pov^^er of causing 

 unlimited quantities of similar matters to pass into 

 the same state. Thus, a small quantity of the juice 

 of grapes in the act of fermentation, added to a 

 large quantity of the same fluid, which does not fer- 

 ment, induces the state of fermentation in the whole 

 mass. So likewise the most minute portion of milk, 

 paste, juice of the beet-root, flesh, or blood, in the 

 state of putrefaction, causes fresh milk, paste, juice 

 of the beet-root, flesh, or blood, to pass into the 

 same condition when in contact with them. 



These changes evidently differ from the class of 

 common decompositions which are effected by chem- 

 ical afiinity ; they are chemical actions, conversions, 

 or decompositions, excited by contact with bodies 

 already in the same condition. In order to form a 

 clear idea of these processes, analogous and less 

 complicated phenomena must previously be studied. 



The compound nature of the molecules of an or- 

 ganic body, and the phenomena presented by them 

 when in relation with other matters, point out the 

 true cause of these transformations. Evidence is 

 afl'orded even by simple bodies, that in the formation 

 of combinations, the force with which the combining 

 elements adhere to one another is inversely propor- 

 tional to the number of simple atoms in the com- 

 pound molecule. Thus, protoxide of manganese by 

 absorption of oxygen is converted into the sesqui- 

 oxide, the peroxide, manganic, and hypermanganic 



