ferent: gin, rum, and the strong liquors contain from 40 to 50 per cent, of alcohol; port contains from 15 to 25 per cent.; sherry or madeira, from 15 to 20 per cent.; champagne and burgundy, from 10 to 13 per cent.: hock, from 10 to 12 per cent.; claret, from 8 to 12 per cent.; cider and strong ale, 5 to 9 per cent.; beer or porter, from 2 to 5 per cent.; koumiss, from 1 to 3 per cent. The United States Pharmacopœia fixes the specific gravity of rectified spirit at 0.820, which corresponds to 91 per cent. of absolute al- cohol. The amount of alcohol in spirituous liq- uids is estimated by observing their specific gravity; but as they usually contain other sub- stances besides water, they must be distilled be- fore a determination can be made. Alcohol in its various forms, especially if taken habitually, is highly injurious to health. While it promotes very powerfully the secretion of the gastric juice, it sets up inflammation of the gastric walls and gradually produces chronic dyspepsia. (See Alcohol, Physiological and Poisonous Action of.) The effects of chronic alcohol poisoning are described in the article Alcoholism (q.v.).
Alcohol cannot be entirely freed from water by distillation. Anhydrous, or absolute alcohol, may be prepared by boiling strong commercial alcohol with unslaked lime until a small sample is turned yellow by barium oxide; to remove the last traces of water the alcohol thus obtained may be further treated with anhydrous copper sulphate and finally distilled over a small quan- tity of metallic sodium. The presence of traces of water may be readily detected by the use of dehydrated copper sulphate, which remains white only in perfectly anhydrous alcohol. Absolute alcohol acts as a deadly poison. It is a colorless liquid of specific gravity 0.8062 at 0°; it boils at 78° and solidifies at about 130° below zero C. It is extremely hygroscopic and mixes in all proportions with water, ether, chloro- form, carbon disulphide, and many other liquids. It is also an excellent solvent for many substances, such as fats, oils, gums, resins, and a number of inorganic compounds, and is thus largely employed in the preparation of tinctures, varnishes, dyes, perfumes, etc. The presence of alcohol in aqueous solutions is best detected by the so-called iodoform reaction: small quantities of iodine and of potash almost immediately produce in the presence of alcohol a precipitate of iodoform, which may be readily recognized by its odor. In this manner it has been demon- strated that minute quantities of alcohol are present in the soil, in water, and in the atmos- phere. Small quantities of alcohol have likewise been found in the urine in diabetes. When acted on by an excess of dry chlorine gas, alcohol is transformed into chloral, from which, by the ac- tion of alkali, very pure chloroform may be ob- tained; chloroform may also be prepared from al- cohol directly by the action of bleaching powder (chloride of lime). When warmed with concen- trated sulphuric acid, alcohol yields ordinary ether. Alcohol is thus extensively employed in the manufacture of chloral, chloroform, and ether.
Aqueous alcohol was separated bv distillation from the mixture obtained through fermentation in the Middle Ages. Lowitz was the first to prepare anhydrous alcohol in 1796. The composition of alcohol was first determined by Saussure in 1808.
Consult: Stevenson, A Treatise on Alcohol, with Tables of Specific Gravities (London, 1888); Maercker, Handbuch der Spiritusfabrikation (Berlin, 1889); French translation, two volumes, Lille, 1889); and Roux's series of seven books on the manufacture of alcoholic beverages, published under the general title La fabrication de l'alcool (Paris, 1885-92). See Acetylene.
ALCOHOL, Physiological and Poisonous Action of. Alcohol in a concentrated form exerts a local irritant action on the membranes and tissues of the animal body, mainly through its abstracting water from the tissues. According to its greater or less dilution, the quantity in which it is administered, the emptiness or fullness of the stomach, and the nature of the animal on which the experiment is made, alcohol may either act as a gentle stimulus, which assists the digestive process, or it may excite such a degree of irritation as may lead to the disorganization of the mucous membrane. It is well known that dilute alcohol in contact with animal matter, at a temperature of from 60° to 90°, undergoes acetic fermentation, and it was maintained by Leuret and Lassaigne that a similar change took place in the stomach. It appears, however, that only a small part of the alcohol undergoes this change; and it is the small part thus changed which produces, with other fermentations of the fats and proteids, the penetrating and disagreeable character of the eructations and vomited matters of drunkards. Alcohol is, however, for the most part, rapidly absorbed in an unchanged state either in the form of liquid or vapor, and this absorption may take place through the cellular (or connective) tissue, the serous cavities, the lungs, or the digestive canal. This is shown by the experiments of Orfila, who fatally intoxicated dogs by injecting alcohol into the subcutaneous cellular tissue, or by making them breathe an atmosphere charged with alcoholic vapor; and by Rayer, who injected about half an ounce of proof-spirit into the peritoneum of rabbits, which almost immediately became comatose and died in a few hours. It is, however, only with absorption from the intestinal canal that we have to deal in relation to man. Almost the whole of this absorption is effected in the stomach, and it is only when alcohol is taken in great excess, or is mixed with a good deal of sugar, that any absorption beyond the stomach occurs. The rapidity of the absorption varies according to circumstances. The absorption is most rapid when the stomach is empty and the drinker is fatigued, while the action is delayed by a full stomach, and especially by the presence of acids, tannin, or the mucilaginous and saccharine ingredients of many wines. The chief action of alcohol is that on the central nervous system; either, as some hold, stimulating the cells of the cerebrum to greater activity, or, as others claim, exerting a paralvzing action from the very start and reducing control or inhibition. The self-restraint that regulates thought and speech being removed, the person seems more brilliant and capable. Recent studies, however, show that under the influence of even small amounts of alcohol the capacity for work is less and its quality deteriorates. Kraepelin, in studying some of the simpler problems of addition, multiplication, spelling, and pronunciation, found that the acuteness of perception was diminished and the intellectual powers weakened. Purely muscular power was increased with small doses and
