The Concrete Juice of an Uncertain Tree.
History. — In relation to the plant from which this gum-resin is derived we have no correct information. By some, it is laid down as coming from the Stalagmitis Gambogioides, upon the authority of Murray, but, Dr. Graham has satisfactorily determined that there is no such plant in existence. It is now supposed to be derived from trees of Ceylon, which produce gum-resins agreeing closely or entirely with the officinal gamboge — these are the Garcinia Cambogia and the Hebradendron Gambogioides, which last is supposed to be the tree from which it is principally had — though on merely presumptive evidence. The Heb. Gambogioides belongs probably to the class and order of the sexual system, Monoecia Monadelphia, and to the natural order Clusiaceae or Guttiferae. It is a moderate-sized tree, with opposite, petiolate, obovate-elliptical, coriaceous, smooth, entire, and abruptly-acuminate, shining leaves, dark-green above, and paler beneath. The flowers are unisexual, sessile and axillary ; the calyx membranous, persistent, and consisting of four sepals ; the corolla four-petalled ; the fruit is a pleasant, saccharine, quadrilocular berry, about the size of a cherry, crowned with a sessile stigma, and containing one seed in each division. Incisions are made into the tree, or a large slice is pared from the bark, from which the juice flows, thick, viscid, and bright-yellow, which is scraped off and dried in the sun. If left on the tree, it speedily concretes into dry tears or irregular masses. It is collected in Siam and Cochin-China, and sent to Canton and Calcutta, from which places it is imported into this country.
The best kinds are the Pipe gamboge, and Ceylon gamboge, which last is seldom had in this country. The pipe gamboge is in cylindrical rolls, from one to two inches in diameter, sometimes hollow internally, doubled, or agglutinated into irregular cakes weighing some pounds, and much flattened. Externally they are striated, of a dull orange color, sometimes of a greenish tinge, derived from the reeds into which they are molded. Pipe gamboge is of a yellow-orange color, which deepens on exposure to the air, brittle with a conchoidal, smooth, and glistening fracture ; it possesses but little smell, and a taste at first insipid, but succeeded by an acrid sensation in the fauces. It forms a yellow, smooth, rather persistent emulsion with water, and is soluble in the alkalies, and the essential oils ; alcohol dissolves all the resin, leaving the gum ; water forms only an emulsion with it. Sulphuric ether dissolves most of the resin, and ammoniated alcohol forms a solution with it which is not disturbed by water. The resin is the active principle. Its specific gravity is 1.221. The strong acids dissolve it, and deposit a yellow precipitate when water is added to the solution. It has been called Gambogic acid, as it has the property of combining with salifiable bases. It contains nearly four parts of resin, one of gum, beside water and impurities. Its color, as well as its medical properties, resides in the resin ; one part of which will impart a yellowish tinge to ten thousand parts of water or spirit.
A variety called Cake or Lump gamboge is sometimes imported ; it is in irregular masses of two or three pounds, containing many sticks or other impurities, is less brittle than the pipe, vesicular, splintery in fracture, and without luster, but in other respects resembling the finest gamboge. Other varieties are occasionally seen, but they are all of inferior quality. The inferior kinds may be recognized by their many impurities, their greater hardness and coarser fracture, by the brownish or grayish color of their broken surface, which is often marked with black spots, and by the green color imparted to their decoction, when cooled, on the addition of tincture of iodine. The pure gum-resin is completely dissolved by the successive action of ether and water.
Properties and Uses. — In large doses, gamboge is a powerful irritant, causing gastro-enteritis, and death ; and is said to produce diffuse inflammation of the cellular tissue, when applied beneath the skin. On account of its severity of action, and its liability to cause serious symptoms, it is seldom employed singly, as a purgative; yet when combined with other cathartics it forms a safe and excellent physic. It may, however, be safely administered alone in moderate doses, by reducing it to a state of fine division with other comparatively inert powders, as sulphate, or bitartrate of potassa. It thus operates effectually as a hydragogue, without occasioning much tormina or constitutional exhaustion. In medicinal doses it is a drastic, hydragogue cathartic, causing nausea, griping, and copious watery stools, on which account it is often used in dropsy, in combination with squills, cream of tartar, etc. It has also been used for the expulsion of tapeworm, in torpor of the bowels, dysmenorrhea, etc. Two grains of sulphate of quinia combined with one grain and one-fourth of gamboge, and administered three times a day, have been highly recommended in cases of long-continued constitutional debility, with constipation. United with an alkali, it acts upon the kidneys, and proves diuretic.
Its use is contra-indicated in gastritis, enteritis, during pregnancy, menorrhagia, hemorrhoids, in excited, irritable, or diseased uterus, and where there is irritation or disease of the urinary organs. When taken in large doses, or when it acts with severity, the best remedy to counteract its dangerous effects, is a solution of some alkali, as pearl-ash water, to be followed by general treatment if inflammatory symptoms be present. Dose, in pill, powder, or alkaline solution, from one to fifteen grains ; the larger doses given in small quantities, and repeated at short intervals until it operates.
Off. Prep. — Pilulae Aloes Compositae ; Pilulae Gambogiae Compositae; Pilulae Podophyllini Compositae.