This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Pure anhydrous alcohol is a limpid, colorless liquid of a greater fluidity than water, does not congeal, but acquires an- oily consistence when cooled to 90° C. (130° F.). It has a penetrating but refreshing and agreeable odor and a hot, pungent taste, owing to its abstracting water from the tissue of the tongue. Its elementary composition is: carbon, 52.32; oxygen, 34.38; hydrogen, 13.30. The great affinity of alcohol for water is the cause of its poisonous action on the system, since it destroys the vital functions of the tissues by abstracting their constitutional moisture with avidity. These violent effects are not produced when alcohol, in a diluted state, is taken in small quantities; only a pleasant hilarity follows, though larger draughts are succeeded by stupor and intoxication. It is a powerful stimulant and antiseptic.
Absolute alcohol has a neutral reaction to test paper. It dissolves iodine, bromine, a little phosphorus and sulphur, the alkalies and alkaline earths, the chlorides, iodides, and nitrates of many metals, many organic acids, and nearly all alkaloids, resins, volatile oils, camphor and fixed oils. It precipitates from their solutions gum, starch, albumen, gelatine, and many other substances. On account of these properties alcohol is an invaluable agent in analysis and in the preparation of carbonated drinks. For commercial purposes, such as the bottling trade, absolute alcohol is not essential; it is required only in the arts and the chemist's laboratory.
To detect a minute quantity of water in absolute alcohol, Debrunner proposed crystallized permanganate of potassium, which he found to be totally insoluble in anhydrous alcohol, but to impart a red tinge to it in the presence of 0.5 per cent, of water. After Casoria it may be detected by adding a small piece of highly dried sulphate of copper, which becomes blue if water is present.
On an ordinary scale the purification of alcohol is effected by percolating it through recently burned and granulated charcoal, by which the fusel oil is retained; this process is most effectually accomplished if the alcohol has been previously diluted.
The commercial stronger alcohol of 93° to 95° is of a high grade of purity, colorless and odorless, and adapted for all the purposes required by the carbonator. If the alcohol should not bo quite odorless it might be deodorized.
By this is meant an alcohol which has been freed from all odor. Should the commercial alcohol of 95° be imparted with an odor offensive to the purpose it is destined for, it may be made odorless on a small scale by applying the following treatment: To deodorize alcohol mix one gallon of 95 per cent, alcohol with four drachms powdered unslaked lime and two drachms powdered alum, previously mixed together. Shake well and add one drachm spirit of nitrous ether; set aside for a week, and filter through animal charcoal and paper.