This section is from the "A Practical Treatise On Materia Medica And Therapeutics" book, by Roberts Bartholow. Also available from Amazon: A Practical Treatise On Materia Medica And Therapeutics
Alcohol. A liquid composed of 91 per cent by weight (94 per cent by volume) of ethyl alcohol, and 9 per cent by weight (6 per cent by volume) of water. Specific gravity, 0·820 at 60° Fahr. A transparent, colorless, mobile, and volatile liquid of a characteristic, pungent, and agreeable odor, and a burning taste.
Diluted alcohol. A liquid composed of 41 per cent by weight and 486 per cent by volume of absolute ethyl alcohol.
Absolute alcohol. Ethyl alcohol containing not more than 1 per cent by weight of water.
Deodorized alcohol. A liquid composed of about 92·5 per cent by weight, or 95·1 per cent by volume, of ethyl alcohol, and about 7·5 per cent by weight of water.
Amylic alcohol. Fusel-oil.
A peculiar alcohol, obtained from fermented grain or potatoes, by continuing the process of distillation after the ordinary spirit has ceased to come over. An oily, nearly colorless liquid, having a strong, offensive odor, and an acrid, burning taste.
Whisky. An alcoholic liquid, obtained by the distillation of fermented grain (usually corn, wheat, or rye), and at least two years old. Whisky has an amber color, a distinctive taste and odor, and a speciffc gravity not above 0·930 nor below 0·917, corresponding approximately with an alcoholic strength of 44 to 50 percent by weight, or 50 to 58 per cent by volume.
Brandy. An alcoholic liquid obtained by the distillation of fermented grapes, and at least four years old. Brandy has a pale, amber color, a distinctive taste and odor, and a specific gravity not above 0.941 nor below 0.925, corresponding approximately with an alcoholic strength of 39 to 47 per cent by weight, or 45 to 55 per cent by volume.
There is a close correspondence in the alcoholic strength of whisky and brandy, especially when they conform to the official standard. Brandy differs from whisky in that it contains oenanthic and other ethers peculiar to the grape.
A large number of bodies have been classed under the generic term of alcohols. A list of the most important of these is subjoined :
C2H6O or CH40 + (CH2). C3H8O or CH4O+2(CH2). C4H10O or CH40 + 3(CH2). C5H12O or CH40 + 4(CH2) C6H14Oor CH4O + 5(CH2).
These alcohols are called "homologous," because they are closely related to each other, and differ by the common multiple CH2. Ethylic is the common or ordinary alcohol, and amylic is an impurity existing in certain alcoholic beverages—for example, whisky, in which it occurs in consequence of the cupidity of distillers in carrying on the process after all the ethylic alcohol has distilled over. Absolute alcohol should be entirely free from any odor except its native ethereal odor, and no products but carbonic acid and water should result from its combustion.
Whisky is a solution of alcohol in water (48 to 56 per cent), but contains various odorous principles and ethers which impart to it its peculiar physical properties. The best specimens, doubtless, contain traces of fusel-oil, and acetic, butyric, and sometimes valerianic acids are present in it. The reactions of these acids with the alcohol result in the formation of various ethers, and hence old whisky is more fragrant, and therefore more highly prized, than the recent product of the still.
Brandy is also a solution of alcohol in water (48 to 56 per cent). It has a wine-like odor, and a hot, astringent taste. It contains a volatile oil, an ether peculiar to wines (aenanthic ether), coloring-matters, tannic acid, aldehyde, and acetic ether. The color is usually factitious: in pale brandy, the color is derived from the cask; in dark brandy, from caramel. Brandy is made artificially from high-wines by the addition of an ether (cognac, acetic or nitric), of coloring-matter (burnt sugar), and an astringent to give it the necessary roughness of taste (logwood, catechu, etc.).