CHAPTEE XXIII. 



INCOMBUSTIBLE CONSTITUENTS. 



ALTHOUGH during the transformation of grape-juice 

 into wine a large portion of the salts of organic as 

 well as inorganic acids contained in it are precipitated, 

 first with wine ferment, and afterwards with tartar, 

 vet something of each remains dissolved. The crusting 

 which occurs during winter is really separation of 

 cream of tartar, which w^hen once deposited in the 

 form of crystals cannot be again dissolved, or at least 

 but very imperfectly. Besides this, the presence 

 of salts in wine is indicated by manifold reactions, of 

 which we shall speak more particularly below. 



If wine be evaporated, and what remains over 

 burnt, a certain quantity of ash will be obtained ; 

 indeed this may be looked upon as one of the distinc- 

 tive marks of genuine wine, as the amount of ash 

 varies but little in wines of the same kind. I subjoin 

 a table of the quantity of ash in some few kinds of 

 wine, and remark at the same time that the difficulty 

 which occurs in burning the ashes white, seems to 

 indicate the presence of phosphoric acid in them. 





