FEBMENTATION. 89 



the cells are emptied, and sink as sediment to the bot- 

 tom, their albuminous contents undergo decomposi- 

 tion, and some of the constituents are retained in the 

 wine, in a soluble form. During fermentation the liquid 

 becomes turbid, and this result we ascribe to the for- 

 mation of ferment. But as soon as alcohol is produced 

 from the sugar contained in it, the power of the liquid 

 to hold different substances in solution undergoes 

 a great change. 



There is a diminution first in the mucilaginous and 

 saccharine contents of the juice, then those substances 

 decrease which are insoluble in common water, but 

 which can be held in suspension when in a fine state 

 of division ; for example, phosphate, sulphate, and 

 lactate of lime. If, therefore, the gum serves for the 

 formation of ferment, and the cellulose and sugar be 

 resolved into alcohol and carbonic acid, then the 

 liquid, which was rendered turbid at first by the 

 formation of ferment, will continue so during fer- 

 mentation, because the phosphate, sulphate, and 

 tartrate of lime are being continually precipitated. 

 The result of this process is an alcoholic instead of a 

 watery liquid. Cream of tartar is much less soluble 

 in weak spirit than in water, and this is a third 

 cause of the turbidity of the juice which is gradually 

 becoming resolved into wine. The continual increase 

 of the quantity of alcohol in the liquid causes the pre- 

 cipitation of sulphate of potash and tartrate of mag- 

 nesia, or tartrate of potash and magnesia. 



