FERMENTATION. 255 



minded of that seed which fell into good ground, and 

 brought forth fruit, some thirty fold, some sixty fold, 

 some an hundrr 1 fold ? On examination, this notion of 

 organic growth turns out to be more than a mere surmise 

 In the year 1680, when the microscope was still in its 

 infancy, Leeuwenhoek turned the instrument upon this 

 substance, and found it composed of minute globules sus- 

 pended in a liquid. Thus knowledge rested until 1835, 

 when Cagniard de la Tour in France, and Schwann in 

 Germany, independently, but animated by a common 

 thought, turned microscopes of improved definition and 

 heightened powers upon yeast, and found it budding 

 and sprouting before their eyes. The augmentation of 

 the yeast alluded to above was thus proved to arise 

 from the growth of a minute plant now called Torula 

 (or Saccharomyces) Cerevisice. Spontaneous genera- 

 tion is therefore out of the question. The brewer 

 deliberately sows the yeast-plant, which grows and 

 multiplies in the wort as its proper soil. This dis- 

 covery marks an epoch in the history of fermentation. 



But where did the brewer find his yeast ? The reply 

 to this question is similar to that which must be given 

 if it were asked where the brewer found his barley. He 

 has received the seeds of both of them from preceding 

 generations. Could we connect without solution of con- 

 tinuity the present with the past, we should probably be 

 able to trace back the yeast employed by my friend Sir 

 Fowell Buxton to-day to that employed by some Egyp- 

 tian brewer two thousand years ago. But you may urge 

 that there must have been a time when the first yeast- 

 cell was generated. 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 



