82 MICROBES, FERMENTS, AND MOULDS. 



it continues to act on the unmodified sugar. The 

 production of fresh yeast makes the liquor thick, and 

 the amount of alcohol and of carbonic acid increases 

 in accordance with the time for which it is kept, after 

 being bottled or put in closed casks. 



The manufacture of most fermented liquors 

 resembles that of wine or beer ; that of cider is very 

 simple, and consequently approximates to the manu- 

 facture of wine. The apples are cut and crushed, and 

 remain in the vats until fermentation is over; the 

 liquid is then separated from the solid residue, and 

 put into casks or bottles. 



V. CONCERNING SOME OTHER FERMENTED LIQUORS. 



There are many other fermented liquors made in 

 various countries with substances derived from the 

 animal or vegetable kingdom. 



In France, cider or perry is sometimes made from 

 pears or crab-apples. 



What the French call boissons are cheap fermented 

 liquors, prepared from dried raisins or aromatic sub- 

 stances, such as the dried fruit of the coriander, to 

 which water sweetened with treacle is added. Fer- 

 mentation is usually effected by germs borne by the 

 air, or by those introduced by the coriander and the 

 other ingredients of the liquor ; or it may be hastened, 

 as in Belgian beer, by the addition of beer-yeast or 

 baker's yeast. It is effected by the transformation of 



