This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
The U. S. Pharmacopoeia recognizes only two kinds of wine; 1. Sherry Wine, Vinum Xericum, U. S. (Vinum Album, U. S. 1850, White Wine); and 2. Port Wine, Vinum Portense, U. S. (Vinum Rubrum, U. S. 1850, Bed Wine).
The wines used in medicine are exclusively the fermented juice of the grape. The same name has been given to the fermented juice of various other fruits, as the currant, gooseberry, elderberry, etc.; but these are not admitted into the Materia Medica, and should never be employed medicinally in the place of genuine wine, when the latter can be obtained.
Wines have been differently classified, according to their qualities and origin. The most important distinction for the physician is into the light and the strong wines; the former including those which consist exclusively or nearly so of the fermented grape-juice; the latter, those to which brandy or other form of ardent spirit has been added, to increase their body, and enable them to keep better. Among the former are sauterne, claret, champagne, the Rhine and Moselle wines, and burgundy; among the latter, madeira, teneriffe, sherry, and port. It will be noticed that the distinction between the two kinds is not only the difference in the quantity of alcohol they contain, but also in the circumstance that, in the one, this ingredient is in the state in which it was produced by the act of fermentation, in the other, is partly superadded, after having undergone the process of distillation.
Another distinction is into the white and red wines, the former being prepared from colourless grapes, or the juice of the red, without the skins; the latter, from the red, with their skins remaining. The only important difference between them, medically considered, is that the red contain tannic acid, which gives them astringent properties, and the white little or none. Of the wines above mentioned, sauterne, champagne, the hock or Rhine wines, and the Moselle wines, of the lighter varieties, and madeira, teneriffe, and sherry, of the stronger, generally rank among the white; and claret and burgundy, of the light, and port, of the stronger, among the red.
Another distinction is into the still and sparkling, the latter being characterized by the property of effervescence, depending on the presence of carbonic acid. This excess is owing to the circumstance that they have been bottled before the entire completion of the fermentation, so that the carbonic acid subsequently generated is confined. Any wine may be made sparkling in this way; but, generally speaking, it is only the champagne and sparkling moselle that have this quality. An excellent sparkling wine is made at Cincinnati, Ohio, from the juice of the Catawba grape; and I have seen a fine variety, little inferior to French champagne, produced in a vineyard of California, two hundred miles south of St. Francisco.
Some wines are acidulous, others sweet, and others, again, have scarcely any perceptible sourness or sweetness to the taste, though almost all contain acid, and most of them more or less grape sugar. The light wines are generally the most acid.
Besides alcohol and water, wines in general contain small proportions of bitartrate of polassa, malic, tartaric, and carbonic acids, extractive, mucilaginous and colouring matters, oenanthic ether, and a volatile odorous principle; and many of them, grape sugar and tannic acid. The proportion of absolute alcohol contained in them varies, according to Christison, from 6 to 17 per cent. by weight. The table of Brande gives proportions varying from about 10 to 26 per cent.; but it is alcohol of the sp. gr. 0.825, containing a considerable proportion of water, that is here referred to, and the ratio is by measure instead of weight; so that his numbers are necessarily higher. It is probable that the former statement approaches the truth most nearly. It is a point worthy of special notice, that the wines above mentioned as belonging to the lighter class contain, on an average, about half as much alcohol as those belonging to the stronger; and this remark holds true of the several varieties of the two classes. This fact is important in regulating the dose of the wines.
Bitartrate of potassa is most abundant in new wines, and is gradually deposited as they become older. Of the free acids, the malic is said to be most common, the tartaric being generally combined. Carbonic acid is probably in some degree present in all; but is most abundant, of course, in the sparkling. Acetic acid is sometimes present, but always probably as a product of the acetous fermentation of the alcohol, and therefore to be regarded as an impurity.
The odorous matter upon which each wine depends for its characteristic aroma is probably a volatile oil peculiar to each; but it has not been separated. There is in most if not all wines a volatile oily matter, in extremely minute proportion, which serves to impart to wines, as a class, their peculiar flavour, and quite distinct from the characteristic aromatic principles of the several wines. This is the cenanthic ether, discovered by Liebig and Pelouze, and is said not to exceed one in forty thousand parts. It has been obtained separate, and has been found, in this state, to have a disagreeable, very strong, intoxicating odour, and an unpleasant taste. It has been supposed that it might contribute to the intoxicating effects of the wines; but the point has not been determined.
Sugar is not a desirable ingredient in medicinal wines, and the sweeter varieties are therefore little employed.
Tannic acid is present in the red wines, and tends to render them astringent; but its effect in this way is, in some of the lighter wines, more than counteracted by the bitartrate of potas3a, and other saline matter, and by the free acids they contain. Both this principle and the colouring matter is gradually deposited with time; and port wine, so strongly astringent when fresh, becomes after many years almost as colourless and free from astringency as madeira.
By long keeping, wine becomes softer to the taste, in consequence of the deposition of the bitartrate of potassa, to which they mainly owe their tartness, and of the tannic acid and colouring matter, when contained in them. When kept in casks, they gradually lose alcohol; but, according to a not uncommon opinion, their intoxicating property is rat her increased than diminished; a result which, if true, may possibly be ascribed to the production of oenanthic ether.