ORGANIC POISONS. 345 



as well as sugar, it is reproduced by the decompo- 

 sition of the former substance. 



The yeast with which these liquids are made 

 to ferment, has itself been originally produced from 

 gluten. 



The conversion of gluten into yeast in these 

 vegetable juices is dependent on the decomposition 

 (fermentation) of sugar ; for, when the sugar has 

 completely disappeared, any gluten which may still 

 remain in the liquid, does not suffer change from 

 contact with the newly-deposited yeast, but retains 

 all the characters of gluten. 



Yeast is a product of the decomposition of gluten ; 

 but it passes into a second stage of decomposition 

 when in contact with water. On account of its 

 being in this state of further change, yeast excites 

 fermentation in a fresh solution of sugar, and if this 

 second saccharine fluid should contain gluten, 

 (should it be wort, for example,) yeast is again 

 generated in consequence of the transposition of the 

 elements of the sugar exciting a similar change in 

 this gluten. 



After this explanation, the idea that yeast repro- 

 duces itself as seeds reproduce seeds, cannot for a 

 moment be entertained. 



From the foregoing facts it follows, that a body 

 in the act of decomposition (it may be named the 

 exciter), added to a mixed fluid in which its consti- 

 tuents are contained, can reproduce itself in that 

 fluid, exactly in the same manner as new yeast is 



