340 VINOUS FERMENTATION. 



perfect certainty, that ferment is formed from gluten 

 at the same time that the transformation of the sugar 

 is effected ; for the wort contains the azotized mat- 

 ter of the corn, namely, gluten in the same condition 

 as it exists in the juice of grapes. The wort fer- 

 ments by the addition of yeast, but after its decom- 

 position is completed, the quantity of ferment or 

 yeast is found to be thirty times greater than it was 

 originally. 



Yeast from beer and that from wine, examined un- 

 der the microscope, present the same form and gen- 

 eral appearance. They are both acted on in the 

 same manner by alkalies and acids, and possess the 

 power of inducing fermentation anew in a solution 

 of sugar; in short, they must be considered as 

 identical. 



The fact that water is decomposed during the pu- 

 trefaction of gluten has been completely proved. The 

 tendency of the carbon of the gluten to appropriate 

 the oxygen of water must also always be in action, 

 whether the gluten is decomposed in a soluble or in- 

 soluble state. These considerations, therefore, as well 

 as the circumstance which all the experiments made 

 on this subject appear to point out, that the conver- 

 sion of gluten to the insoluble state is the result of 

 oxidation, lead us to conclude, that the oxygen con- 

 sumed in this process is derived from the elements 

 of water, or from the sugar which contains oxygen 

 and hydrogen in the same proportion- as water. At 

 all events, the oxygen thus consumed in the fermen- 

 tation of wine and beer is not taken from the at- 

 mosphere. 



The fermentation of pure sugar in contact with 

 yeast must evidently be a very different process from 

 the fermentation of wort or must* 



In the former case, the yeast disappears during 

 the decomposition of sugar; but in the latter, a 

 transformation of gluten is effected at the same time, 



"* The liquid expressed from grapes when fully ripe is called must. 



