Alcohol is a light, transparent, colorless, volatile, inflammable fluid; mixes in all proportions with water, with evolution of heat and condensation of the mixture, but some hours elapse before the union is complete. It dissolves resins, essential oils (see No. 940 (How to Prepare Essences and Perfumed Spirits)), camphor, bitumen, soaps, sugar, the alkaloids, wax, spermaceti, and various other substances. Boils at 172°, and in a vacuum at 56° Fahr.; curdles milk; coagulates albumen, and separates both starch and gum from their mucilages; uncongealable by cold; powerfully antiseptic to animal or vegetable substances immersed in it; with acids it forms ethers. Its evaporation, like that of ether, produces intense cold. By undergoing the acetic fermentation it is converted into vinegar. Dilute alcohol may be procured by the ordinary process of distillation, from all fermented liquors; when drawn from wine, as in France, it is called brandy; when from rice, as in the East Indies, it is called arrack or toddy; when from grain or malt, as in the United States or Great Britain, it is called whiskey, and when from molasses or the juice of the sugar-cane, as in the "West Indies, it is called rum.

Whiskey is the spirit from which alcohol is usually obtained in this country.

By distilling a hundred gallons of whiskey, between 50 and 60 gallons of alcohol are received in the condenser of a specific gravity of 0.835. By a second distillation, taking care to collect only the first portions, and cautiously managing the heat so as not to allow it to rise to the temperature of boiling water, alcohol may be obtained of a specific gravity of 0.825, which is the lightest spirit that can be received by ordinary distillation. At this stage it contains 11 per cent, of water and some small portions of fusel oil.

The best alcohol is that manufactured under Attwood's patent process, in which manganic acid is used to destroy the fusel oil and other foreign substances. This alcohol withstands the tests of nitrate of silver and sulphuric acid remarkably well. (See No. 1444 (To Test the Purity of Alcohol).)

The high wine, or rectified spirit, distilled and rectified in the United States, and often sold as French pure spirit, is free from all deleterious substances, and nearly scentless. Its strength is usually from 84 to 95 per cent. (See Nos. 53, etc..)

1436. Proof Spirit

1436. Proof Spirit contains 521/2 per cent, by volume of pure alcohol; has a specific gravity of .920 at 60° Fahr.; and is no more than a mixture of 49 parts by weight pure alcohol with 51 parts water. This is the strength of the proof spirit usually employed by perfumers, and for medicinal purposes; but by law (see No. 58 (Gendar's Hydrometer)), proof spirit is equal parts by volume of absolute alcohol and distilled water, having a specific gravity of .933.

1437. Dilute Alcohol

1437.    Dilute Alcohol. Alcohol dilutum ( U. S. Ph.) consists of equal measures of officinal alcohol and water; it contains 39 per cent, by weight, or 46.33 per cent, by volume, of pure or absolute alcohol, and has a specific gravity of .941, equal to 19° of Baum6's light hydrometer.