Alcohol
3 of the 6 encyclopedias on this shelf carry an entry for Alcohol. All 3 are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a term popularly applied to the substance which imparts to fermented and distilled liquors an intoxicating property. In modern chemistry the word has a much wider meaning, being applied to a very numerous class of substances, in many members of which the properties characteristic of ordinary alcohol are conspicuous by their absence. Chemically, an alcohol may be defined as a neutral compound composed of the three elements, carbon, hydrogen, and oxygen. Alcohols are found as natural constituents of many vegetable and animal products, such as certain oils, fats, and waxes. Some alcohols are liquids, while others are solids. So-called ethyl alcohol, or "spirit of wine," is formed in the fermentation of solutions of sugar. When yeast is added to a solution containing grape sugar or glucose, the liquid soon has the appearance of boiling. A fundamental change takes place in the sugar whereby it is broken up into alcohol and carbon dioxide . The process is called fermentation. Yeast alone cannot ferment cane-sugar. The cane-sugar must be first decomposed into fermentable sugar, as grape sugar or fruit sugar; and this decomposition is effected by a substance known as invertase, which invariably accompanies yeast. The ordinary method of obtaining alcohol is to form a thin paste of crushed potatoes, finely ground grain, or of any vegetable material containing starch. The starch is first changed into sugar by the action of malt, then fermentation is produced by the addition of yeast. Commercial alcohol is never pure, but usually contains from five to ten per cent of water. By careful redistillation the amount of water may be reduced to about two per cent, and this can be removed by adding quicklime, which unites with the water. The liquid which is poured off is distilled again, thus forming approximately pure or absolute alcohol. Pure alcohol is a mobile, colorless liquid with an agreeable ethereal odor. It has a strong affinity for water, which it readily absorbs from the atmosphere. It mixes with water in all proportions with marked contraction and rise in temperature. The maximum contraction is obtained by mixing 52 volumes of alcohol with 48 volumes of water, the volume of the mixture being 96.3 instead of 100. Pure alcohol boils at 173 degrees Fahrenheit under one atmosphere pressure, and freezes at 202 degrees below zero. It burns with an intensely hot, pale-blue, non-luminous flame. It has a specific gravity of 0.7938 at 60 degrees temperature; in other words, its weight is about eight-tenths as much as water. The amount of alcohol in a mixture of alcohol and water is determined by means of a special form of hydrometer, called an "alcholometer," the scale of which gives directly the per cent by weight or volume for a given temperature, usually 60 degrees Fahrenheit. The point at which the instrument sinks in pure alcohol is marked 100; a similar point for pure water is marked 0. When placed in a mixture, the instrument sinks to a point intermediate between these marks according to the relative proportions of water and alcohol. Investigations have shown that 100 pounds of the following products of the farm will produce industrial alcohol in the following quantities: Rice, 6 gallons; rye, barley, spelt, corn, and sorghum seed, 5 gallons; Irish potatoes, 1 1/2 gallons; cassava, 2 1/2 gallons; turnips, 4 to 5 gallons; artichokes, 1 1/4 gallons; sugar beets, 2 gallons; sorghum or sugar cane, 1 gallon; waste molasses, 6 gallons; grapes, 2 1/6 gallons; bananas, 1 3/5 gallons; and other fruits from 1 to 1 1/2 gallons. The average range of the alcohol content in various fermented and distilled liquors may be stated as follows: Beers, ale, and porter contain from 2 to 6 per cent of alcohol; wines from 8 to 20 per cent; brandy, whisky, and rum from 45 to 55 per cent. Alcohol is extensively used in the preparation of lacquers, varnishes, dyes, flavoring extracts, and pharmaceutical preparations. It hardens animal tissues and is destructive of most forms of bacteria. These facts make it a valuable preservative for specimens of natural history. It is occasionally of great value in medicine, and in certain emergencies, where prompt stimulating action is demanded, it is indispensable. On account of its low freezing point, it is used instead of mercury in thermometers intended for measuring low temperatures. Wood alcohol is obtained by the careful heating, or so-called "dry distillation," of hardwood-beech, maple, or birch-in iron retorts. The aqueous distillate contains the wood alcohol mixed with acetic acid and some minor ingredients, and is known as pyroligneous acid. Tarry matter and other substances separate out on standing and are then removed. The acetic acid is combined with lime and the wood alcohol purified by fractional distillation and other methods. Wood alcohol boils at 150.8 degrees and burns with a blue flame. It can be used for many of the purposes for which the common ethyl alcohol is used, but on account of its poisonous properties it cannot be used in foods and beverages. Denatured alcohol is ethyl alcohol rendered unfit for drinking by the addition of a substance having a disagreeable taste or odor. Methyl alcohol and benzine are the denaturing agents authorized by the United States commissioner of internal revenue. Ten parts of wood alcohol and one-half part of benzine are added to 100 parts by volume of ethyl alcohol of not less than 90 per cent strength. In Germany, in addition to wood alcohol, a certain amount of pyridine (bone oil) must be added. This gives a denatured alcohol of a very offensive odor, but does not render it unfit for many commercial uses. Other substances have been proposed for denaturing, some of which are the following: gum shellac, camphor, turpentine, acetic acid, aniline blue, castor oil, carbolic acid , caustic soda, and musk. See Arrack ; Absinthe ; Pulque ; Toddy ; Brandy ; Cognac ; Wine ; Beer ; Cider ; Ale ; Whiskey ; Sugar ; Starch ; Distilling ; Brewing ; Bacteria JULIUS HORTVET.
Collier's New Encyclopedia (1921)
a colorless, inflammable liquid, of agreeable odor, and burning taste, termed also spirit of wine, and ethylic or vinic alcohol. In organic chemistry, alcohol is the name given to a class of compounds differing from hydrocarbons in the substitution of one or more hydrogen atoms by the monatomic radical hydroxyl (OH)'. Alcohols are divided into monatomic, diatomic, triatomic, etc., according as they contain 1, 2, or 3 atoms of H (hydrogen), each replaced by (OH)'. Alcohols may also be regarded as water in which one atom of His replaced by a hydrocarbon radical. Alcohol can unite with certain salts, as alcohol of crystallization. Alcohol is said to be primary, secondary, or tertiary, according as the carbon atom which is in combination with hydroxyl (OH) is likewise directly combined with one, two, or three carbon atoms. The hydrocarbon radicals can also have their carbon atoms linked together in different ways, forming isomeric alcohols. Primary alcohols, by the action of oxidizing agents, yield aldehydes, then acids; secondary alcohols, by oxidation, yield ketones; tertiary y alcohols, by oxidation, yield a mixture of acids. Alcohols derived from benzol, or its substitution compounds, are called aromatic alcohols; they contain one or more benzol rings. In chemistry, pure ethyl alcohol, also called absolute alcohol, is obtained by distilling the strongest rectified spirit of wine with half its weight of quicklime. Alcohol is used as a solvent for alkaloids, resins, essential oils, several salts, etc. Alcohol is obtained by the fermentation of sugars, when a solution of them is mixed with yeast, Mycoderma cervisiæ, 25° and kept at a temperature between ween and 30°, till it ceases to give off CO2 (carbonic acid gas). It is then distilled. Proof spirit contains 49.5 per cent. of alcohol, and has a specific gravity of 0.9198 at 20° C. Methylated spirit contains 10 per cent. of wood spirit in alcohol of specific gravity 0.830; it is duty free, and can be used instead of spirits of wine for making chloroform, olefiant gas, varnishes, extracting alkaloids, and preserving anatomical preparations, etc. Wines contain alcohol; port and sherry, 19 to 25 per cent.; claret and hock and strong ale, about 10 per cent.; brandy, whisky, gin, etc., about 40 to 50 per cent. morbid condition
The Encyclopedia of Founding (1892)
The purely spirituous parts of liquors which have undergone vinous fermentation. Alcohol mixes with water in any proportion, giving out heat by the mixture; a mutual penetration of the parts takes place, so that the bulk of the two fluids when mixed is less than when separate. All the alkalies when pure, several of the neutral earths and metallic salts, sulphur in vapor, phosphorous, the essential oils, resins, gum-resins, wax, spermaceti, biliary calculi, etc., are, in different proportions, soluble in alcohol. The substances which are insoluble in alcohol are the alkaline carbonates; all the sulphates; some of the nitrates and muriates, metals; metallic oxides, and metallic acids; all the pure earths; the fixed oils, unless when united to alkalies, or converted into drying oils by metallic oxides; muscular fibre; the coagulum of blood; and albumen. Alcohol is highly combustible, producing intense heat without smoke, and for this reason is well adapted to burn in lamps for chemical and other uses. See FUEL.
What Has Changed in the Last Century
Aiton's chemistry of 1910 still holds — ethanol is a carbon-hydrogen-oxygen compound made by yeast from sugar, boiling at about 173°F — but almost everything social and medical around it has moved. The claim that alcohol "is occasionally of great value in medicine, and in certain emergencies, where prompt stimulating action is demanded, it is indispensable" was abandoned within a generation: alcohol is a depressant, not a stimulant, and it was struck from the standard American pharmacopoeial roster of remedies. In 1988 the International Agency for Research on Cancer classified alcoholic beverages as a Group 1 carcinogen, and in 2023 the World Health Organization stated there is no safe level of consumption. Industrially, the picture also inverted: the United States banned alcoholic drinks under Prohibition from 1920 to 1933, and today most fermentation ethanol goes not into varnishes and extracts but into motor fuel, with the US producing roughly 15 billion gallons a year, mainly from corn.
Written for this edition, 2026.