Prep. Alcohol is a product of the vinous fermentation of sugar, occurring in wine, malt liquors, etc.: these when distilled, afford spirits, such as brandy and rum; and re-distilled, give rectified spirit. It is usually procured from malt.

Prop. dt Comp. Rectified spirit is alcohol (C4 H5 O, HO) with 16 per cent. of water, and resembles alcohol in most of its properties; sp. gr. 0.838. It burns with a blue flame without smoke; odour and taste, alcoholic; it should not be made cloudy by the addition of water, not tinged red with sulphuric acid. It contains about 84 per cent. of absolute alcohol. Four fluid ounces, with 3 measures of the volumetric solution of nitrate of silver, exposed for 24 hours to a bright light, and then decanted from the black powder which has formed, undergo no further change when again exposed to light with more of the test; indicating the presence of but a small amount of matter capable of decomposing nitrate of silver. Alcohol when pure undergoes no change under the influence of this salt and a bright light. The three measures of the silver solution contain nearly half a grain of nitrate of silver.