The bulb of the Allium sativum, Linné.
COMMON NAME: Garlic.
Botanical Source.—The garlic plant has a stem about 2 feet high, leafy below the middle. It terminates in an umbelliferous head of pink, red or whitish flowers, intermixed with bulbs, enveloped in a calyptriform, horned spathe. They appear in July, and are rather longer than their stamens. The leaves are acute, distichous, glaucous, and channelled above. The medicinal part is the very proliferous, clustered bulbs, many of which are invested in the same silvery skin.
Description.—The bulb is compound, subspherical, covered with membranous scales. About 8 wedge-like, compressed bulblets, are arranged circularly around a central stem-base. The smaller bulbs are appressed laterally, and consist of succulent scales, enveloping a central, fleshy mass. Garlic has an acrid, warm taste, and a disagreeable, pungent, alliaceous odor.
History, Action, and Chemical Constituents.—Garlic is a native of Sicily, and is indigenous in Asia Minor and Central Asia, but is cultivated in gardens in various sections of the United States and Europe. The bulbs of this plant are official; when removed from the ground some of the stem is left attached, so that after desiccation, by exposure to the sun, or in a warm room, several stems may be secured together, thus forming small bundles for sale. The root loses about one-half its weight by drying, but scarcely any of its smell or taste. Garlic should be used without being previously dried. Though changing color, garlic may be preserved in a closed jar with a small amount of alcohol for some length of time, without impairment of its virtues. All parts of this plant, but more especially the bulbs, have a strong, offensive, very penetrating and diffusible smell, and an acrimonious, almost caustic taste; both of these properties are owing to an acrid, volatile oil, of a deep, brownish-yellow color (when crude), heavier than water, and possessing, in a strong degree, the odor and taste of the plant; sulphur is one of its constituents, the oil containing 6 per cent of a compound (C6H12S2) and 60 per cent of a substance (C6H10S2); the rest are higher sulphur compounds. Allyl sulphide does not occur in the oil (Semmler, 1892). When purified it is without color, not so heavy as water, and consists chiefly of a sulphur compound. Water dissolves a small amount of it, while in ether and alcohol it is readily soluble. In contact with the skin, it occasions violent pain, rubefaction, and frequently vesication. Garlic yields its properties to alcohol, vinegar, acetic acid, and boiling water by infusion.
Action, Medical Uses, and Dosage.—Garlic is stimulant, diuretic, expectorant, and rubefacient; it is used both for medical and culinary purposes. The medicinal effects above stated are owing to the absorption of its volatile oil, the stimulating action of which causes thirst, promotes the activity of the various excretory organs, as the skin, kidneys, and mucous membrane of the air-tubes, communicating its odor to their excretions. It has been beneficially used in coughs, catarrhal affections, pertussis, hoarseness, worms, and calculous diseases, during the absence of in animation. Externally, it has been employed as a resolvent in indolent tumors, and as a counter-irritant in cerebral and pulmonary affections. When applied along the spinal column and over the chest of infants, in the form of poultice, it is very useful in pneumonia; and placed over the region of the bladder, it has sometimes proved effectual in producing a discharge of urine when retention has arisen from torpor of the bladder. Garlic juice, oil of sweet almonds, and glycerin, of each equal parts, mixed, and dropped in the ear, has cured several cases of deafness, due probably to excessive cerumen, or to chronic debility of the mucous tissues of the organ of hearing. The dose of fresh garlic is 1 or 2 drachms; of the juice, a small teaspoonful. Large doses cause nausea, vomiting, purging and other unpleasant symptoms. The juice is often made into a syrup with sugar, by nurses, for coughs, catarrh, and pulmonary affections of infants. The odor imparted to the breath by garlic and onions, may be very much diminished by chewing roasted coffee grains, or parsley leaves and seeds.
Related Product.—ALLYL TRIBROMIDE. A product closely related to oil of garlic may be produced by the interaction of bromine and allyl iodide. It has the composition C3H5Br3 (or CH2Br.CHBr.CH2Br.), and the name allyl tribomide or tribromhydrin. A product identical with rectified oil of garlic is produced by acting upon allyl iodide with sulphide of potassium in alcoholic solution. Allyl tribromide is a colorless, or pale-yellowish fluid, congealing with the appearance of a stearopten at 10° to 15° C. (50° to 59° F.). Allyl tribromide has been administered in 5-drop doses (in capsules) in infantile convulsions, angina pectoris, hysteria, asthma, whooping-cough, and similar spasmodic complaints.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.