STUDIES OJJ FERMENTATION. 277 



Moreover, there will be as many distinct fermentations brought 

 about by one ferment as there are fermentable substances 

 capable of supplying the carbon element of the food of that 

 same ferment^ in the same way that the equation of the 

 nutrition of an animal will vary with the nature of the food 

 which it consumes. As regards fermentation producing alcohol, 

 which may be effected by several different ferments, there will 

 be, in the case of a given sugar, as many general equations 

 as there are ferments, whether they be ferment-cells, properly 

 so called, or cells of the organs of living beings functioning as 

 ferments. In the same way the equation of nutrition varies in 

 the case of different animals nourished on the same food. And 

 it is from the same reason that ordinary wort produces such a 

 variety of beers when treated with the numerous alcoholic 

 ferments which we have described. These remarks are appli- 

 cable to all ferments alike ; for instance, butyric ferment is 

 capable of producing a host of distinct fermentations, in conse- 

 quence of its ability to derive the carbonaceous part of its food 

 from very different substances, from sugar, or lactic acid, or 

 glycerine, or mannite, and many others. 



When we say that every fermentation has its own peculiar 

 ferment, it must be understood that we are speaking of the 

 fermentation considered as a whole, including all the accessory 

 products. We do not mean to imply that the ferment in 

 question is not capable of acting on some other fermentable 

 substance and giving rise to fermentation of a very different 

 kind. Moreover, it is quite erroneous to suppose that the pre- 

 sence of a single one of the products of a fermentation implies 

 the co-existence of a particular ferment. If, for example, we 

 find alcohol among the products of a fermentation, or even 

 alcohol and carbonic acid gas together, this does not prove that 

 the ferment must be an alcoholic ferment, belonging to alco- 

 holic fermentations, in the strict sense of the term. Nor, 

 again, does the mere presence of lactic acid necessarily imply 

 the presence of lactic ferment. As a matter of fact, different 

 fermentations may give rise to one or even several identical 



