Alcoholic beverages are generally classified as fermented or distilled. The former include wines and beers; the latter, spirits and liqueurs.

Spirits are made by fermenting various saccharine substances until as much alcohol as possible has been generated in them. From the mixture of sugar, ferments, water, and alcohol the latter is distilled. When separated in this way alcohol can be made of various grades of strength and purity. The saccharine matters that are subjected to fermentation are derived commonly from barley, corn, rice, potato, sugar, and molasses.

The odor and flavor of each kind of spirit depend upon its-source and upon different volatile ethers and by-products of fermentation that also pass through the still. Their medicinal action is that of alcohol.

Whisky is defined by the United States Pharmacopeia as "an alcoholic liquid obtained by the distillation of the mash of fermented grain (usually mixtures of corn, wheat, and rye) and at least four years old." It has an alcoholic strength of from 44 to 55 per cent, by volume. It should be free from disagreeable odors. Its specific gravity should be between 0.945 and 0.924. When spirits of any kind are kept, the volatile ethers and aldehydes that give flavor and character to them change and become more agreeable. For this reason distilled liquors are always ripened for a variable period of time.

Brandy of the standard of the United States Pharmacopeia is "obtained by distillation of the fermented, unmodified juice of fresh grapes, and should be at least four years old." Its specific gravity varies from 0.941 to 0.925. It contains from 46 to 55 per cent, by volume of alcohol. Brandy is kept for many years to ripen.

Rum is distilled from fermented molasses. It is often made by adding molasses caramel and various essences or flavorings to a solution of rectified spirit. It contains about the same percentage of alcohol that whisky and brandy do.

Gin is distilled from a rye mash. It is flavored by juniper berries, which are put in the mash during distillation. It contains from 15 to 20 per cent, of alcohol, but is often strengthened by the addition of proof spirit, so that it contains from 30 to 35 per cent. Gin undergoes a double distillation and contains, therefore, less solid matter than the other forms of spirit. No gin contains so much as 1 per cent. There is no sugar in it and little acid.

Liqueurs and bitters are made from pure alcohol and various spirits and wines by the addition of sugar, aromatic herbs, and essences. The following table, compiled by Hutchison, will afford some idea of the composition of a few of those most commonly used:

Beer or ale and stout or porter are made by fermenting malt and hops. Malt is made by germinating moistened barley at a uniformly moderate temperature. During germination the starch of the grain is converted into dextrin and sugar. Malt after it is dried and ground, is mixed with water to make a 'mash,' which in turn is heated to different degrees by different brewers. In this way the starch is more completely transformed into sugars and the latter are carried into solution. The action of the diastase of malt is arrested by boiling the wort, or filtrate, of the mash. Hops are boiled with it in order to extract some tannin, a bitter principle, and extractives. After the wort has been boiled it is rapidly cooled, and finally fermented by the addition of yeast. To obtain a uniform product great care is taken that only a pure culture of yeast is used, and accidental infection of wort by other ferments is guarded against. Most of the yeast gradually rises to the top and can be skimmed off; some settles to the bottom of the tank in which fermentation is carried on. The beer is drawn into casks, where fermentation to a limited extent continues. The yeast is finally completely precipitated, and the clear beer bottled. If it stands long in casks the slight fermentation that goes on gradually increases the percentage of alcohol in it, making a 'heavier' beer.

Beer and ales are described as 'mild' or 'bitter,' accordingly as they contain relatively much or little hops. The temperature at which malt is dried and mash is made also modifies the taste and character of the final product. Sugar and dextrins are important constituents of the fermented beverages.

Stout or porter is made as beer is, but the malt used in its brewing is first roasted, by which process some caramel is formed in it. This gives to the final product a dark color.

All these beverages contain from 3 to 8 per cent, of alcohol, from 1/2 of 1 to nearly 1 per cent, of sugar, from 2 to 5 per cent, of dextrins, and possess a demonstrable acidity.

The acidity of beer will check starch digestion in the stomach. Its bitterness, however, increases the flow of saliva and the secretion of gastric juice. Beer delays the chemical process of gastric digestion more than the small amount of alcohol in it will account for. It increases and often creates abnormal acidity of the stomach, and flatulence. Beer and stout are especially likely to produce obesity. Their use predisposes the drinker to gout and lithemic affections. They cannot be used by diabetics because of the carbohydrates which they contain. They also aggravate renal inflammations, cystitis, and urethritis. They are frequently drunk in quantities sufficient to distend the stomach even to a pathologic extent. Many persons feel somnolent after drinking beer, wherefore it is frequently taken at night as a mild soporific.