ALOES is a drug of great antiquity, for we find Dioscorides (50 A.D.) making mention of aloe as a substance obtained from a plant, and possessing cathartic properties. The Feat demand for A. in Britain has led to its importation from numerous sources, includ ing Bombay, Arabia, Socotra, Madagascar, the cape of Good Hope, the Levant, and the West Indies. The drug is the inspissated juice of various species of aloe (q.v.). All these are characterized more or less by producing large, thick, fleshy leaves, stiff and brittle, pointed, and generally terminating in a strong spine, filled with a mucilaginous pulp internally, and containing in the proper vessels of their exterior portion an intensely bitter juice, which yields the medicinal substance A. It is obtained, sometimes in the form of tears, by incision, spontaneous exudation, and inspissation upon the plant; sometimes by spontaneous evaporation of the juice which drops or exudes by pressure from the leaves when cut away near the base; sometimes by evaporating the same juice with the aid of heat; and lastly, by evaporating together the juice and the decoction of the leaves.
Owing to the great difficulty of determining the true botanical source of any given sample, the following names are made use of in commerce to denote the various kinds of A. found in the market—namely, Socotrine, Clear, Cape, En-st Indian, Barbadoes, and Caballine A. The most important arc: 1. Socotrine A. (Aloe Socotrina), so called from its supposed source, the island of Socotra. near the mouth of the Arabian gulf. This is the most esteemed of all the vari eties used in medical practice. 3Iany hold that this is only a fine variety of East Indian A., but the characters given in the Adinburgh Plirmacoliceia—a garnet-red translucency in thin pieces, and almost complete solubility in spirit of the strength of sherry—define a particular species, which is the true Socotrine A. of pharmacologists.
2. East Indian A. (Aloe Indica), also called hepatic A., from its liver-brown color, is imported into Bombay from Arabia and Africa, and is known in India by the name of Bombay A. A considerable portion is probably obtained from the same sources as the Socotrine A., which it resembles in color; and according to Dr. Pereira, "the two are
sometimes brought over intermixed, the Socotrine occasionally forming a vein in a cask of hepatic A." 3. Barbadoes A. (Aloe Barbadensis) is prepared in the West Indies from A. Socotrina, and from a variety of A. aulgaris. We learn ffom Browne's Natural History te* Janiaica that the largest and most succulent leaves are placed upright in tubs, that the juice may dribble out. This evaporated, forms what is sold as Socotrine A.; but the common A. is obtained by expressing the juice out of the leaves, boiling it with water, evaporating and pouring it into gourds; whence this kind is often called gourd A. It is much used for veterinary medicine, and thus brings a high price in the market.
Caballine A. (Aloe caballina) is a very coarse kind, and is so called because it is con sidered fit only for horses. It contains many impurities, such as wood, sand, and char coal, and evidently constitutes the lowest stratum in the vessels in which the better sorts are allowed to cool. It is now in a great measure superseded in veterinary practice by Barbadoes A.
All kinds of A. are remarkable for their disagreeable taste. The odor is peculiar, and is more perceptible when the drug is breathed upon. A. is in a great measure soluble in water, and more so in hot than cold water. A. was formerly considered to be a gum-resin ; but the portion which was thought to be of the nature of gum is now regarded as a variety of extractive, and to it the name of aloesin has been given.
employed in small doses, A. exerts a tonic, and in larger doses, a cath artic action. It is considered by some authorities to stimulate the liver, and also to supply the place of deficient bile in torpidity of the intestinal canal, and more especially towards its lower part. Both taken singly, and also in combination with other cathartics, A. is perhaps the most important and the most extensively used of vegetable remedies of its class ; and there is no end to the variety of cases in which it may be employed with advantage.