344 ANALYSIS OF WINE. 



but neither sugar nor glucic acid. All acids, and 

 many other bodies were removed from it. 



Evaporation rendered the liquid dark brown, so that 

 some organic substance must be contained in it. It 

 was proved, however, to be neither sugar nor glucic 

 acid, since when warmed with potash it did not turn 

 brown. Lime water occasioned no precipitate ; sugar 

 of lead formed no precipitate in it, but basic acetate 

 of lead did. Nitrate of silver, when saturated to 

 excess with ammonia, gave a reduction of silver. But 

 this did not decompose the test solution of oxide of 

 copper and potass. 



It would be superfluous here to seek after the 

 doubtful substance which figures under the name of 

 extractive matter, and with which we are quite 

 unacquainted. Its amount is insignificant. 



If we now consider what we have found, setting 

 aside the inorganic substances and volatile bodies, we 

 have the following substances red colouring matter, 

 tannic acid, albumen, racemic, and tartaric, but no 

 citric acid, malic acid, gum, no pectin, uncrystallisable 

 sugar, a brown substance deducible in part from a small 

 amount of glucic acid existing in the wine, besides 

 extractive matter, which cannot at present be more 

 accurately described. This sketch must be rendered 

 complete by special examination of each of those sub- 

 stances, which may be separately obtained in the way 

 I have indicated. 



