This is chemically a toxin of the yeast plant, as the spirituous product of vinous fermentation (whereby are given intoxicating properties of varying relative strength to ardent spirits, wines, and malt liquors, the same product being powerfully stimulating, and remarkably antiseptic). There are different grades of alcohol, according to the source from which they are respectively derived; as "grain alcohol,"prepared from maize, or other grain; "root alcohol," from beets, and potatoes; and "moss alcohol," made in large quantities from reindeer moss, and Iceland moss, in Norway, Sweden, and Russia. Such spirits as whisky, gin, and brandy contain from 40 to 50 per cent of absolute alcohol most wines contain from 7 or 8 to 20 per cent; and malt liquors from 2 to 10 per cent. Each molecule of alcohol consists of two atoms of carbon, six of hydrogen, and one of oxygen; it contains no nitrogen. When taken into the body alcohol burns by the carbon being set free and then combining with the oxygen, precisely as when paraffin is burnt in a motor car, being a source of energy; alcohol can be made to burn thus within the human body to compensate for the wasteful expenditure of animal heat in fevers, when digestion is arrested, and fails to furnish caloric.

Nevertheless, during health only a limited quantity of alcohol can be burnt within the body each day, at the rate of not more than an ounce and a half of whisky, or brandy; this quantity being well diluted, and taken in doses of half an ounce, at intervals of at least four hours. Such a quantity is all that the average man of normal temperature can utilise; any excess beyond it will be harmful as a positive poison. Then again, alcohol is only a false stimulant, its action as such being in reality a protest of the heart's muscular walls against the noxious irritant; and such stimulation is invariably followed by a corresponding subsequent depression. As a drug, alcohol vexes the heart, which then sends blood with a rush to stagnate within the outermost blood-vessels in the skin, causing this briefly to feel warmer, though the internal body suffers a cold enfeeblement of the general circulation. Indeed, this loss of heat inside the system is so devitalizing that it often predisposes to pneumonia. Thus it comes about that the net result of taking alcohol, in whatever form, is to lower the inner temperature of the body.

It is true that by dilating the blood-vessels of the general skin-surface a deceptive sense of warmth is induced because of the increased heat given off, for a short time only, by radiation, though alcohol does not really keep out the cold, but suffers the heat of the body to sensibly escape through the skin. During fevers, therefore, alcohol often renders helpful service by unlocking the surface blood-vessels, and thus setting free the mischievous, superabundant heat. If a person has been already exposed to chilling cold, and the blood has been repelled into the internal organs so as to stagnate there, with threatened congestion, then the timely administration of alcohol in a hot drink may save the situation by restoring a proper distribution of blood throughout the whole body. So that by all means let alcohol be thus taken when the person comes indoors wet, and shivering; but it must be carefully avoided when proceeding out of doors to encounter frost, and rain, whilst the internal temperature would become lowered by any such a dram.

Alcohol has been proved to possess the power of producing antitoxic effects of an active sort against the tubercular disease of consumptive sufferers. If dock labourers who indulge freely in alcoholic drinks, become affected by pulmonary consumption, it is found that (in spite of their harmful alcoholic excess) the mortality from this disease is less among those who drink heavily than in the more moderate imbibers. The alcohol appears to effect under certain circumstances a neutralization of tuberculous poison in the system; it acts further by serving to block up the blood-vessels around the diseased parts of the lungs, thereby isolating these infective parts; so that (as certain modern physicians pronounce) in all probability a plentiful (but not immoderate) use of alcohol promises true benefit for cases of actual tubercular consumption.

We may conclude generally that alcohol is an unnecessary article of diet for persons in complete health (though a moderate use of natural, sound wine seems to augment the agreeables of life). As regards the form in which alcohol may be best used, malted liquor seems most suitable for youth, wine for middle life, and spirits to be reserved for the aged. It cannot be said that alcohol is favourable to the production of perfectly sound brain work. Out of 124 instances (leading men in literature, science, and art) who were consulted on this question, none ventured to seriously recommend alcohol as a useful aid to the performance of mental labour. It is rather under conditions just short of health - in overwork, fatigue, and feeble old age - that the beneficial effects of alcohol become most marked, and chiefly by aiding digestion; therefore it is most profitably taken with meals only, in such quantity, and of such sort, as are best borne by the individual patient. But for aged persons with whom, by reason of their arteries being stiff through senility, and their circulation otherwise impeded about the surface of the body, a laborious action of the heart occurs under alcohol, with a liability of its walls to become dilated, then this is certainly questionable, particularly in the shape of ardent spirit; possibly some generous, well-matured wine of subdued alcoholic strength may be more safely allowed.

With regard to the taking of alcohol with water at night as grog for inducing sleep, when this has become difficult, or disturbed, any such practice is ordinarily a mistake. For natural sleep the brain should be comparatively bloodless; but a spirituous beverage as a night-cap produces quite the opposite effect; if the grog is strong, a measure of narcotism, and stupor may simulate sleep, but the penalty will be exacted afterwards by reactionary depression. Only will a moderate allowance of alcohol at night be beneficial, when the general circulation is so weak, and inefficient at the end of the day, with depressed vitality, coldness, and feeble action of heart, that blood stagnates passively about the brain for lack of sufficient power to propel it onwards from the heart, and nervous centres. . Under such a condition of things, then alcohol may be judiciously given, and will promote better sleep on rational grounds.