FERMENTATION. 241 



minded of that seed which fell into good ground, and 

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

 some an hundred 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 instru- 

 ment upon yeast, and found it composed of minute 

 globules suspended in a liquid. Thus knowledge rested 

 until 1835, when Cagniard de la Tour in France, and 

 Schwann in Grermany, 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 ToTula (or Saccharomyces) Cerevisice. Sponta- 

 neous generation 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 

 Egyptian brewer two thousand years ago. But you may 

 urge that there must have been a time when the first 

 yeast-cell was generated. Grranted — 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 



B 



