BACTERIA AND FERMENTATION 113 



yeast cells and these bacteria, a second series with living 

 yeast cells only, a third series with bacteria only, and the 

 conclusions which Pasteur arrived at as the result of these 

 labours were as follows : 



" As for the interpretation of the group of new facts which 

 I have met with in the course of these researches, I am confident 

 that whoever shall judge them with impartiality will recognise 

 that the alcoholic fermentation is an act correlated to the life and 

 to the organisation of these corpuscles, and not to their death or 

 their putrefaction, any more than it will appear as a case of contact 

 action in which the transformation of the sugar is accomplished 

 in the presence of the ferment without the latter giving or taking 

 anything from it." 



Pasteur occupied six years (1857-1863) with further eluci- 

 dation of his wonderful discovery of the potency of these 

 hitherto unrecognised agents, and the establishment of the 

 fact that " organic liquids do not alter until a living germ 

 is introduced into them, and living germs exist every- 

 where." 



It must not be supposed that to Pasteur is due the whole 

 credit of the knowledge acquired respecting the cause of 

 fermentation. He did not first discover these living organ- 

 isms; he did not first study them and describe them; he 

 was not even the first to suggest that they were the cause 

 of the processes of fermentation or disease. But, neverthe- 

 less, it was Pasteur who " first placed the subject upon a 

 firm foundation by proving with rigid experiment some of 

 the suggestions made by others." Thus it has ever been 

 in the times of new learning and discovery: many contribu- 

 tors have added their quota to the mass of knowledge, even 

 though one man appearing at the right moment has drawn 

 the conclusions and proved the theory to be fact. 



In order that no confusion may arise in the mind of the 

 reader, we may here say that, although fermentation is 



