FERMENTATION 271 



to trace back the yeast employed by my friend Sir Fowell 

 Buxton to-day to that employed by some Egyptian brewer 

 two thousand years ago. But you may urge that there 

 must have been a time when the first yeast-cell was gen- 

 erated. Granted exactly as there was a time when the 

 first barley-corn was generated. Let not the delusion lay 

 hold of you that a living thing is easily, generated because 

 it is small. Both the yeast-plant and the barley-plant 

 lose themselves in the dim twilight of antiquity, and in 

 this our day there is no more proof of the spontaneous 

 generation of the one than there is of the spontaneous gen- 

 eration of the other. 



I stated a moment ago that the fermentation of grape- 

 juice was spontaneous; but I was careful to add, "in what 

 sense spontaneous will appear more clearly by and by." 

 Now this is the sense meant. The wine-maker does not, 

 like the brewer and distiller, deliberately introduce either 

 yeast, or any equivalent of yeast, into his vats; he does 

 not consciously sow in them any plant, or the germ of any 

 plant; indeed, he has been hitherto in ignorance whether 

 plants or germs of any kind have had anything to do with 

 his operations. Still, when the fermented grape-juice is 

 examined, the living Torula concerned in alcoholic fer- 

 mentation never fails to make its appearance. How is 

 this? If no living germ has been introduced into the 

 wine-vat, whence comes the life so invariably developed 

 there ? 



You may be disposed to reply, with Turpin and oth- 

 ers, that, in virtue of its own inherent powers, the grape- 

 juice, when brought into contact with the vivifying atmos- 

 pheric oxygen, runs spontaneously and of its own accord 

 into these low forms of life. I have not the slightest ob- 



