162 STUDIES ON FERMENTATION'. 



In this series we determined the presence of the small 

 apiculated form of yeast (S. apicnlatus) in the tubes that fer- 

 mented, only once finding it associated with saccharomyces 

 pastorianus. 



We need hardly say that the grapes which we employed were 

 perfectly ripe, the vintage having already commenced in some 

 of the Jura cantons. 



This experiment shows that, even when the grapes are per- 

 fectly matured, it by no means follows that each individual 

 grape must carry germs of ferment, and that some grapes may 

 be crushed, in some instances several together may be crushed, 

 without being able to set up a fermentation. In the presence 

 of these novel facts, those who support the hypothesis of the trans- 

 formation of the albuminous matter contained in the juice of 

 grapes into yeast will no doubt admit the untenabiKty of their 

 opinions, since their hypothesis requires that every grape or 

 number of grapes, when crushed, should ferment, in contact 

 with air. 



On the same day we prepared another series of tubes, using 

 grapes of a variety called the trousseau. 



Nos. 1, 2, 3, and 4 tubes containing one whole grape. 



Nos. 5 and 6 tubes containing some of the wood of a branch. 



No. 7 tube containing some of the wood of a branch from 

 which the grapes had been detached. 



In the course of the following days fermentation took place 

 in 4, 5, and 7. 



In this case three out of four of the uncrushed grapes did not 

 cause the must in which they were placed to ferment ; whilst 

 the same must fermented in one of the two tubes containing 

 wood of the branch, and in the other remained unchanged ; and, 

 lastly, the tube containing the woody peduncles of the bunch 

 fermented. 



We have already remarked that it was more particularly the 

 wood of the bunch that was charged with germs of ferment. 

 The truth of this assertion was proved by the following series 

 of experiments. 



