354 
WHAT IS WINE? 
By august DUPEE, Ph.D. 
Lecturee on Chemtstet to Westminstee Hospital. 
W INE is the fermented juice of the grape, pure and simple ; 
and if anything else has been added to it, the resulting 
liquid is not, strictly speaking, wine. Such a definition would, 
however, necessarily exclude the greater number of beverages 
drunk in Great Britain under the name of wine ; but as this 
would be practically inconvenient, we may extend the above 
definition so as to include in it all fermented liquids, the basis 
of which is the juice of the grape, either pure or with such 
additions only as are believed to improve the durability of the 
wine. 
This limitation would divide wines into two classes — the first 
consisting of pure natural wines, the second of all fortified 
wines. It must, however, exclude entirely all compounds of 
Avhich grape juice forms but an unimportant ingredient, or that 
contain no grape juice at all; such as some of the vile 
decoctions manufactured at Hamburg, and imported to this 
country under the name of Elbe Sherry and Port ; and also the 
different beverages known as British wines. 
Grape juice consists essentially of an aqueous solution of 
grape sugar, fruit sugar, tartaric and malic acids, partly free, 
partly in combination with potash, vegetable albumen, and 
mucilage ; sometimes a small quantity of an essential oil (im- 
parting a peculiar flavour, as in the muscatel grape), together 
with a small amount of mineral substances, chiefly potassic 
chloride, and sulphate, and calcic phosphate. The skins and 
seeds of the grape contain albuminous substances, colouring 
matter, tannin, and a kind of fat ; substances which are, under 
certain conditions, dissolved during fermentation, and which in 
their turn produce certain notable effects upon the wine. 
For the purpose of wine making the grapes are first crushed, 
either by being passed between rollers or by being trodden by 
men. The pulpy mass thus produced is then placed in powerful 
presses, by means of which the juice is separated from the 
