ALCOHOL. — Alcohol of the pharma copoeias is one of a series of hydrocarbon compounds, all of which have as their base a radicle called ethyl, whose chem ical composition is expressed by the formula CH. Chemically, alcohol is a hydrate of ethyl, or hydrated oxide of ethyl. To distinguish it from other members of the group, particularly fusel-oil (amyl-alcohol) and wood spirit (methyl-alcohol), the alcohol of medicine is called ethyl-alcohol. It is known in the British Pharmacopoeia as rectified spirit or rectified spirits of wine, from its being obtained by distillation and subse quent rectification, or purification, from a mash of potatoes or grain, or from wine. What is known as strong alcohol contains 91 per cent., by weight, of pure spirit (U. S. P.), and has a specific grav ity of 0.820. Dilute alcohol contains 45.5 per cent., by weight, of pure spirit (TT. S. P.), with a specific gravity of 0.928.
Alcohol is usually exhibited in medi cine in different diluted forms, known as beverages, which may be grouped ac cording to the percentage of alcohol present in them. The so-called spirits (whisky, brandy, rum, gin, arrack) con tain about 50 per cent. of alcohol. The heavy wines (port, sherry, Madeira, etc.) contain about 20 per cent., but are usually too sweet for the use of sick persons; when "dry" (free or nearly free from sugar), they are frequently useful to convalescents and to those who are debilitated. The light table-wines (claret, Burgundy, champagne, Tokay, Moselle, hock, and Rhine wines) contain from 5 to 10 per cent. of alcohol; many of the Rhine wines are, however, not suited to those having a tendency to the oxalic diathesis, on account of the oxalic acid which they contain. Malt liquors (ale, stout, beer) contain diastase, which aids the digestion of starchy foods and tends to produce obesity. They are especially tonic in their effects and contain from 3 to 15 per cent. of alcohol.
Pure alcohol is also used in combi nation with various tinctures and aro matics, to secure accuracy of dosage, to avoid the effects of the more irritating ingredients of poor or bogus liquors, and often in private practice to avoid colli sion with the prejudices of the, laity, or again when there is a tendency toward the abuse of alcoholic beverages.
Dose and Physiological hol, in prolonged contact with the skin, evaporation being prevented, penetrates the tissues beneath the cuticle, owing to its tolerably-high diffusive power, and excites a sense of heat and superficial inflammation. It may be thus employed as a counter-irritant. Owing to its vola tility, alcohol is sometimes used topically to cool the surface of the body. It co agulates albumin, and is sometimes used to cover sores or wounds with a thin, protective, air-excluding layer, which promotes healing.
Taken internally, the effects vary ac cording to the size of the dose taken. When a small dose is taken, it con stringes the mucous membrane of the mouth and throat (often used diluted as an astringent gargle in relaxed throat, scurvy, salivation, etc.), and, on reach ing the stomach, it produces a sense of warmth, which is quickly followed by a feeling of general well-being, com fort, and restfulness. The heart-beat is sometimes accelerated; the arteries are relaxed. The muscular fibres of the skin are relaxed, and the blood becomes more equally distributed over the different parts of the body; if the extremities are pale and cold, they may resume their natural color and temperature. The glands are stimulated generally; the perspiration is increased; the amount of urine is augmented, and the secretions of the mucous glands throughout the alimentary tract respond to the increased stimulus. The appetite, when poor, is improved, the special senses rendered more acute, and relaxation and meteor ism of the intestines are relieved.
In the stomach a double action is ob served on both the gastric juice and the secreting membranes. A small quantity of alcohol produces an insignificant ef fect on the pepsin of the gastric juice; a larger quantity, however, inhibits or destroys entirely its food-dissolving ac tion. In like manner, a small quantity of alcohol augments the secretion of the gastric juice; larger quantities cause inflammation of the mucous membrane, with increased secretion of a thick, te nacious mucus and a loss of secreting power. The appetite becomes impaired or lost and a feeling of nausea is induced.