32 Manual of Veterinary Microbiology. 



carbo-hydrates, polyatomic alcohols, the lower fatty 

 acids, and albuminoids. According to the substance 

 predominating in their products, fermentations are de- 

 scribed as alcoholic, acetic, lactic, butyric, viscous, 

 ammoniacal, etc. 



Microbes capable of developing fermentations are 

 called zymogenic. 



Putrefaction. — By putrefaction is meant the decom- 

 position of the substance of organized beings through 

 the agency of microbes. This decomposition super- 

 venes shortly after death ; exceptionally it is observed 

 during life as we will see in the special part of this 

 work. The microbes which determine it are called 

 septogenic. It consists in a series of fermentations so 

 associated that the products of the one form the point 

 of departure for the following. These fermentations 

 occur simultaneously and take eifect upon the various 

 immediate principles of the organism : albuminoid 

 substances, hydrocarbonaceous bodies, etc. 



But the decomposition of these last named princi- 

 ples giving rise to fermentations simpler and better 

 known, and specially denominated as such, the term 

 putrefaction refers more particularly to the microbic 

 degradation of albuminoid molecules. 



Many microbic species are concerned in putrefac- 

 tion, these species varying according to the case ; there 

 are some which are quite frequently met with, such 

 as bacterium termo, bacillus subtilis (hay bacillus), and 

 bacillus septicus, micro-germs whose characteristics will 

 be indicated later, we always meet with an association 

 of aerobic and anaerobic organisms. 



The bodies which arise during putrefaction are nu- 

 merous : hydrogen, sulfuretted, carburetted and phos- 



