124 YEAST 



IV 



carbonic acid formed proceeds from the sugar. 

 How, in that case, could we conceive the action of 

 the ferment on it ? I think that the first por- 

 tions of the acid are due to a combination of the 

 carbon of the ferment with the oxygen of the 

 sugar, and that it is by carrying off a portion of 

 oxygen from the last that the ferment causes the 

 fermentation to commence the equilibrium be- 

 tween the principles of the sugar being disturbed, 

 they combine afresh to form carbonic acid and 

 alcohol." 



The three views here before us may be familiarly 

 exemplified by supposing the sugar to be a card- 

 house. According to Stahl, the ferment is some- 

 body who knocks the table, and shakes the card- 

 house down; according to Fabroni, the ferment 

 takes out some cards, but puts others in their 

 places ; according to Thenard, the ferment simply 

 takes a card out of the bottom story, the result 

 of which is that all the others fall. 



As chemistry advanced, facts came to light 

 which put a new face upon Stahl's hypothesis, and 

 gave it a safer foundation than it previously pos- 

 sessed. The general nature of these phenomena 

 may be thus stated : A body, A, without giving 

 to, or taking from, another body B, any material 

 particles, causes B to decompose into other sub- 

 stances, C, D, E, the sum of the weights of which 

 is equal to the weight of B, which decomposes. 



Thus, bitter almonds contain two substances, 



