FERMENTATION. 135 



by the name of yeast. After a time these appear- 

 ances cease, the fermented liquor becomes clear 

 and transparent, and no more gas is discharged. 

 The liquor now has lost its sweetness and viscidity, 

 and has acquired the vinous taste and intoxicating 

 quality. Sugar appears to be essential to this pro- 

 cess ; and all mucilaginous substances containing 

 sugar are capable of this fermentation, which is 

 called the vinous. 



Wine is made in this manner from the juice of 

 the grape ; if the fermentation be checked when 

 at its height, by excluding the air, the wine begins 

 to ferment anew, and effervesces when again ex- 

 posed to the air. The sparkling wines, as Cham- 

 pagne, are prepared in this manner, and hence 

 should be considered as imperfect wines. 



To prepare vinous liquors from grain or corn, it 

 must first be converted into malt, by steeping it in 

 water, and then exposing it to the air, turning it 

 frequently over ; by this process, the gluten of 

 which the germ consists is separated, and 'the 

 fecula is converted into sugar by the germination 

 of the seed. 



Beer is made by boiling the malt in water, which 

 produces a sweet liquor called 'wort; this is con- 

 verted into beer by fermentation and the addition 

 of hops, which furnish a bitter substance. 



Wine, beer, and all fermented liquors, owe their 

 intoxicating qualities to a peculiar substance which 

 they contain, and which is the produce of fermen- 

 tation alone. This substance is a fluid called alko- 

 hol, or spirit of wine, and may be* separated in a 

 pure state by distillation. When first obtained it 

 is mixed with a quantity of water, but if it be re- 

 distilled, it is obtained very pure, and is then called 

 rectified alkohoL Alkohol is of a strong heating 



K 4 



