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Researches on Wines and other Fermented Liquors. By Lewis 

 C. Beck, M. D., Professor of Chemistry and Botany in the 

 University of the City of New York, &c. &c. 



Having recently been engaged in a series of experiments to 

 determine the proportion of alcohol contained in several kinds 

 of wine, and other fermented liquors, I was induced to examine 

 some other points connected with their history ; and now pre- 

 sent for publication, in a condensed form, the results of ray in- 

 quiries. 



Composition of Wine— The composition of wine is very 

 variable. The substances found in it are water, alcohol, unde- 

 composed sugar, gum, extractive matter, vegetable albumen, 

 acetic acid, bitartrate of potassa, tartrate of lime, tartrate of 

 alumina and potassa, sulphate of potassa, chloride of sodium, 

 and, in the red wines, red colouring matter, and, in those of 

 champaigne, carbonic acid. 



Acetic and Carbonic Acids. —Acetic acid is often found in the 

 wines from northern countries, and in altered wines, it is formed 

 at the expense of the alcohol. Almost all wines, however, ex- 

 hibit the acid reaction. In champaigne, it is owing to free 

 carbonic acid, but in others it is due to the bitartrate of po- 

 tassa. The effervescence which is observed on adding carbon- 

 ate of potassa to wine, and the subsequent precipitation, are th^ 

 results of the action of this excess of tartaric acid, and the con- 

 sequent liberation of a portion of tartrate of lime, which this 

 salt most generally contains. 



Malic Acid.— It has been frequently stated, that wine con- 

 tains malic acid, and a malate of lime is said, by Chaptal, to be 

 formed by the addition of lime water to wine ;— an opinion 

 which seems also to be countenanced by IVIr Brande, But the 

 existence of this acid is rendered doubtful, if not disproved, by 

 the fact that an insoluble precipitate results, as well from the 

 addition of ammonia or potassa, as of lime. Now, the malates 

 of these alkalies are very soluble, and I)ence we may more 

 safely ascribe the precipitate thrown down in all tliese cases to 

 the saturation of the excess of tartaric acid contained in the 

 bitartrate of potassa, by which means the insoluble tartrate of 

 lime, which is usually combined with it, is liberated. 



VOL. XIX. VO. XXXVIt. JULY 1835, ,[ 



