226 Germination and Fermentation of Grains, &c. 



ing 23 ounces, and 24 pounds of barley not germinated, 

 containing only five ounces of sugar, it follows, that four 

 times more alcohol was formed than there was sugar in this 

 farina. Lavoisier, however, asserts that 100 pounds of sugar 

 furnish only 58 pounds of alcohol. 



7th, Twenty-four pounds of germinated and ground barley, 

 made to ferment under the same circumstances as barley not 

 germinated, presented the same phenomena, and only varied 

 in their products. There were two litres 0'3 of alcohol at 

 40 degrees, which makes five pounds of alcohol for a quintal 

 of barley, or three times more alcohol than there was sugar; 

 and this answers to the produce of barley not germinated. 



It must be concluded from these results that it is some 

 other substance than sugar which is converted into alcohol, 

 although sugar is indispensable to its production and to the 

 establishment of fermentation. 



8th, Two pounds of farina of bolted wheat, mixed with 

 six pounds of water at 60° (140° F.) remained six hours with- 

 out motion. The next day, after having remarked the swell- 

 ing of the mass, we placed the matrass upon a sand-bath a 

 little heated, and added water to favour the disengagement 

 of the gas. We obtained hydrogen gas twice larger in vo- 

 lume than carbonic acid. The vessel, having been taken 

 off the sand-bath, the temperature having decreased to 14 P 

 (5/° F.) the fermentation all at once stopped, The liquid, 

 when submitted to distillation, did not yield alcohol, but an 

 acid liquor. 



The farina of wheat, therefore, does not form alcohol by 

 fermentation : yeast is indispensable for this fermentation, 

 although it does not enter into the composition of alcohol ; 

 by accelerating the alcoholic fermentation, it opposes the 

 formation of vinegar. When, on the contrary, the fer- 

 mentation is very slow, the alcohol becomes acetous in pro- 

 portion as it is formed ; perhaps even then sugar and the 

 other fermenting substances, pass into the acid stale without 

 alcoholizing. 



XXXV. Ob. 



