This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
Use. - In preparing all the medicated wines in the U.S.P. U.S.P. Vinum Rubrum. Red Wine. A deep red alcoholic liquid, made by fermenting the juice of coloured grapes with their skins.
Characters. - Red wine should have a full, fruity, moderately astringent, pleasant taste without decided sweetness or excessive acidity. It should have a pleasant odour free from yeastiness. Its sp. gr. at 15°.6 C. (60° F.) should not be less than 0.989 nor more than 1.010. Tests. - If 10 cc. of red wine be diluted with an equal volume of distilled water, and treated with 5 drops of test-solution of ferric chloride, the liquid should acquire a brownish-green colour due to tannic acid. Upon evaporation and twelve hours drying on the water-bath, it should leave a residue of not less than 1.6 per cent. nor more than 3.5 per cent.
Using litmus-paper as an indicator, 250 cc. of red wine should require for complete neutralisation not less than 15 nor more than 26 cc. of the volumetric solution of soda. If 50 cc. of red wine be treated with a slight excess of water of ammonia, the liquid should acquire a green or brownish-green colour; if it be then well shaken with 25 cc. of ether, the greater portion of the ethereal layer removed, and evaporated in a porcelain capsule with excess of acetic acid and a few fibres of uncoloured silk, the latter should not acquire a crimson or violet colour (absence of anilin colours). With test-solution of acetate of lead, red wine should form a heavy precipitate, which may vary in colour from bluish-green to green.
B.P. Alcohol Amylicum. Amylic Alcohol. Synonym: Fousel Oil.
Amylic alcohol, C5H11HO, with a small proportion of other spirituous substances. An oily liquid, contained in the crude spirit produced by the fermentation of saccharine solutions with yeast, and separated in the rectification or distillation of such crude spirit.
Characters. - A colourless liquid with a penetrating and oppressive odour, and a burning taste. When pure its specific gravity is 0.818, and its boiling-point 270° F.
Solubility. - Sparingly soluble in water, but soluble in all proportions in alcohol, ether, and essential oils.
Uses. - It is oxidised into valerianic acid.