248 FERMENTATION 



FERMENTATION OF SUGAK. 



The peculiar decomposition which sugar suffers 

 may be viewed as a type of all the transformations 

 designated fermentation. 



When yeast is made into a thin paste with water, 

 and 1 cubic centimeter of this mixture introduced 

 into a graduated glass receiver filled with mercury, 

 in which are already 10 grammes of a solution of 

 cane-sugar, containing 1 gramme of pure solid 

 sugar; it is found, after the mixture has been 

 exposed for 24 hours to a temperature of from 

 20 to 25 C. (6877 F.), that a volume of car- 

 bonic acid has been formed, which, at C. (32 F.) 

 and an atmospheric pressure indicated by 0*76 

 metre Bar. would be from 245 to 250 cubic centi- 

 meters. But to this quantity we must add 11 

 cubic centimeters of carbonic acid, with which 

 the 1 1 grammes of liquid would be saturated, 

 so that in all 255 259 cubic centimeters of 

 carbonic acid are obtained. This volume of car- 

 bonic acid corresponds to from 0*503 to 0'5127 

 grammes by weight. Now Thenard obtained from 

 100 grammes of cane-sugar 0*5262 of absolute al- 

 cohol. 100 parts of sugar from the cane yield, 

 therefore, 103*89 parts of carbonic acid and alco- 

 hol. The entire carbon in these products is equal 

 to 42 parts, which is exactly the quantity originally 

 contained in the sugar. 



The analysis of sugar from the cane, proves that 



