REPRODUCTION OF YEAST. 283 



is liberated, a circumstance which happens only in 

 decompositions of the most energetic kind. Neither 

 ferment nor any substance similar to it is formed in 

 this case ; and we have seen that in the fermenta- 

 tion of saccharine vegetable juices, no escape of 

 hydrogen gas takes place. 



It is evident that the decomposition which gluten 

 suffers in an isolated state,, and that which it under- 

 goes when dissolved in a vegetable juice, belong to 

 two different kinds of transformations. There is 

 reason to believe that its change to the insoluble 

 state depends upon an absorption of oxygen, for its 

 separation in this state may be effected under cer- 

 tain conditions, by free exposure to the air, without 

 the presence of fermenting sugar. It is known also 

 that the juice of grapes, or vegetable juices in gene- 

 ral, become turbid when in contact with air, before 

 fermentation commences; and this turbidity is owing 

 to the formation of an insoluble precipitate of the 

 same nature as ferment. 



From the phenomena which have been observed 

 during the fermentation of wort *, it is known with 

 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 azotised 

 matter of the corn, namely, gluten in the same 

 condition as it exists in the juice of grapes. The 

 wort ferments by the addition of yeast, but after 



* Wort is an infusion of malt ; it consists of insoluble parts of this 

 substance dissolved in water. TRANS. 



