A liquid composed of 91 per cent. by weight (94 per cent. by volume) of ethyl alcohol (C2H5HO; 46), and 9 per cent. by weight (6 per cent. by volume) of water.

Characters. - A transparent, colourless, mobile, and volatile liquid, of a characteristic, pungent and agreeable odour, and a burning taste. It boils at 78° C. (172°4 F.), and is readily inflammable, giving a blue flame without smoke. Specific gravity 0.820 at 15°.6 C. (60° F.), and 0.812 at 25° C. (77° F.). It should not change the colour of blue or red litmus-paper previously moistened with water.

Impurities. - Fusel oil, amyl alcohol, methyl alcohol, aldehyde, oak-tannin, foreign organic matters.

Tests. - If a portion of at least 50 cc. be evaporated to dryness in a glass vessel, no residue or colour should appear. If mixed with its own volume of water and one-fifth its volume of glycerin, a piece of blotting-paper on being made wet with the mixture, after the vapour of alcohol has wholly disappeared, should give no irritating or foreign odour (no fusel oil). And if a portion be evaporated to one-fifth its volume, the residue should not turn reddish upon the addition of an equal volume of sulphuric acid (no amyl alcohol). When treated in a test-tube with an equal volume of solution of potassa, there should not be an immediate darkening of the liquid (no methyl alcohol, aldehyde,, and oak-tannin). If a portion of about 150 cc. be digested for an hour with 20 grs. of carbonate of lead and filtered, the filtrate then distilled from a water-bath, and the first 20 cc. of the distillate treated with 1 cc. of test-solution of permanganate of potassium, the colour should not disappear within one or two minutes (absence of methyl alcohol). If 20 cc. are shaken in a glass-stoppered vial, previously well rinsed with the same alcohol, with 2 cc. of test-solution of nitrate of silver, the mixture should not be rendered more than faintly opalescent during one day's exposure to direct sunlight (absence of more than traces of foreign organic matters, fusel oil, &c).

B.P. Spiritus Rectificatus. Rectified Spirit. Alcohol, C2H6O, with 16 per cent. of water; obtained by the distillation of fermented saccharine fluids.

Characters. - Colourless, transparent, very mobile and inflammable, of a peculiar pleasant odour, and a strong spirituous burning taste. Burns with a blue flame without smoke. Specific gravity 0.838. Remains clear when diluted with distilled water. Odour and taste purely alcoholic.

Tests. - Four fluid ounces with thirty grain-measures of the volumetric solution of nitrate of silver exposed for twenty-four hours to bright light, and then decanted from the black powder which has formed, undergoes no further change when again exposed to light with more of the test solution (no fusel oil).

Impurities. - Water, fusel oil.

Spiritus Tenuior, B.P.; Alcohol Dilutum, U.S.P. Proof Spirit, B.P.; Diluted Alcohol, U.S.P.

Rectified spirit, 5 pints, mixed with distilled water, 3 pints; specific gravity 0.920, B.P. Alcohol, 45.5 per cent. by weight (53 per cent. by volume), and distilled water, 54.5 per cent. by weight (47 per cent. by volume); specific gravity 0.928 at 15.6° C. (60° F.), and 0.920 at 25° C. (77° P.), U.S.P.