Alcohol in prolonged contact with the skin, evaporation being prevented, excites a sense of heat and superficial inflammation. It coagulates albumen and hardens the animal textures. The epithelium of the mouth is corrugated by it—a result due to the abstraction of water and condensation of the albumen. In the stomach alcohol causes a sense of warmth, which diffuses over the abdomen, and is quickly followed by a general glow of the body. In moderate quantity it induces a superficial congestion of the mucous membrane—a dilatation of the arterioles—and this increased blood-supply enables the mucous follicles and the gastric glands to produce a more abundant secretion. The increased formation of the stomach-juices is doubtless somewhat determined by the stimulation of the mouths of the glands, in accordance with a well-known physiological law. The excitation of the gastric mucous membrane, when habitual, results in important changes; a gastric catarrh is established—for the mucous follicles, under the influence of repeated stimulation, pour forth a pathological secretion. The gastric glands at first simply produce an increased amount of gastric juice, but abnormal stimulation results in pathological changes in this secretion. The increased blood-supply to the mucous membrane sets up an irritation of the connective tissue, which undergoes hyperplasia; the proper secreting structure is encroached upon, and the glands suffer atrophic changes which result in still more important modifications of the gastric juice. Alcohol also affects directly the constitution of the gastric juice by precipitating the pepsin from its solution and by arresting the activity of this ferment.

In small doses, not too frequently repeated, alcohol increases the digestive power by stimulating the flow of blood and soliciting a greater supply of the stomach-juices. Large doses impair digestion directly by precipitating the pepsin, an albuminoid ferment. That a small quantity does not produce the same results in a comparative degree, is simply due to the fact that it is too far diluted, by the quantity of fluid present in the stomach, to act on the pepsin.

The structural alterations induced by the habitual use of alcohol, and the action of this agent on the pepsin, seriously impair the digestive power. Hence it is that those who are habitual consumers of alcoholic fluids suffer from disorders of digestion—gastric catarrh. The abnormal mucus which is elaborated in great quantity, acts the part of a ferment, and the starchy, saccharine, and fatty elements of the food undergo the acetic, lactic, and butyric fermentations. Acidity, heartburn, pyrosis, regurgitation of food, and a peculiar retching in the morning (morning vomiting of drunkards), are produced.

As alcohol is a very diffusible substance, it enters the blood with great facility, and probably almost all of that taken into the stomach passes into the blood from this organ, and does not reach the small intestine. The liver is consequently the first organ, after the stomach, to be influenced by the ingested alcohol. The blood of the portal vein, rendered more highly stimulating by the presence of alcohol, increases for the time being the functional activity of the liver-cells, and, as is the case with the stomach, a more abundant glandular secretion follows. Frequent stimulation and consequent over-action result in impairment or loss of the proper function of the part, as is the universal law. The hepatic cells, over-stimulated, produce an imperfect product; they are affected by fatty and atrophic changes, and shrink in size; and the connective tissue of the liver undergoes hyperplasia. The first result of the structural alterations is an increase in the size of the organ; but with the shrinking of the hepatic cells, and the contraction of the newly-formed connective tissue, the liver becomes smaller, nodulated, and hardened. To this change the term cirrhosis has been applied. It is essentially a slowly-developing and chronic malady, and long indulgence in alcoholic liquids is necessary to its production.

In small doses, alcohol increases the action of the heart and the cutaneous circulation; a slight general rise of temperature is observed; and all of the functions are, for the time being, more energetically performed. If a considerable dose be taken, the phenomena of exhilaration, of excitement, of slight intoxication ensue. A still larger quantity causes loss of muscular power, impaired co-ordination of voluntary movements, and rambling incoherence. When a toxic dose is taken, the stage of excitement is of short duration; profound insensibility, with stertorous breathing and complete muscular resolution, quickly follow.

As respects the action of alcohol on the nervous system, it is obvious that its first effect is to increase the functional activity of the brain ; the ideas flow more easily, the senses are more acute, the muscular movements are more active. These effects are coincident with the increased action of the heart, the slight rise of temperature, and the greater activity of the functions of the organism in general. With the increased action of the alcohol on the cerebrum the excitement becomes disorderly, the ideas incoherent and rambling, the muscular movements uncontrolled and incoordinate (over-stimulation of the cells of the gray matter). With an excessive quantity, the functions of the cerebrum are suspended, and complete unconsciousness ensues; the reflex movements cease; the functions of organic life are performed feebly; and, by an extension of the toxic influence to the centers presiding over these movements, respiration and circulation are finally arrested.

That these effects on the intra-cranial organs are due to the direct action of the alcohol has been shown. Alcohol has been discovered in the fluid contained in the ventricles, and has been distilled from the cerebral matter; and Hammond has demonstrated that it has a special affinity for nervous matter, being found in the cerebro-spinal axis and in the nerves, in greater quantity than in other tissues of the body. As a result of the direct contact, chiefly, but in part also from the variations in the intra-cranial blood-current, important structural alterations are gradually wrought in the cerebral matter. The cells of the gray matter become more or less fatty and shrunken, the neuroglia undergoes hyperplasia, shrinking and condensation of the whole cerebrum ensue (sclerosis), and the cerebro-spinal fluid relatively increases. The objective evidences of these pathological changes are seen in the impaired mental power, the muscular trembling, the shambling gait, of the drunkard.

In some subjects from sudden excess of a periodical kind, in others from a failure of the stomach to dispose, not only of aliment, but of the accustomed stimulus, a peculiar morbid state, known as delirium tremens, is produced. Peculiarity of the nervous system—idiosyncrasy—is an important factor in the causation of this condition, and probably also the use of alcoholic beverages rich in fusel-oil—for Richardson has shown, and the author has repeatedly confirmed the observation, that amylic alcohol causes tremors and muscular twitching "identical with the tremors observed in the human subject during the alcoholic disease known as delirium tremens."