gambo ge (or gamboge)

[A corruption of Cambodia, the name of the district in Annam, where it is found.] 1. Chem.: Gamboge, or camboge, is a gum resin containing about 70 per cent. of resin, and 24 per cent. of soluble gum. It is obtained by piercing the bark of Garcinia morella , var. pedicel lat a , a tree belonging to the order Guttifere, growing in Cambodia, Siam, and the south part of Cochin China. The juice is allowed to harden in bamboo reeds, hence it occurs in commerce in the form of pipes which are striated externally. Gamboge is hard and brittle, breaking with a yellow-brown vitreous conchoidal fracture; its powder is a bright yellow color; it is inodorous, has a slight taste, but when chewed is acid. When rubbed with water the gum di olves, forming a yellow emulsion with the suspended resin. Gamboge is soluble in alcohol and in ammonia. The resin can be extracted by ether; it is a hyacinth-red color, and yields a yellow powder; it di olves in alkalies with a deep red color; the resin fused with caustic potash yields phoroglucin, iso-uvitic acid, pyro tartaric acid, and an amorphous syrupy acid. Gamboge is used as a pigment in water-color painting. By the action of nitric acid it is oxidized into picric and oxalic acids. An inferior kind of gamboge in the form of flat cakes is prepared in Ceylon from He bra dendron gambo gio ides . 2. Pharm .: Gamboge is used in the preparation of Pilula cambogicæ compos itæ, Compound Gamboge Pill, composed of gamboge, Barb a does aloes, compound powder of cinnamon, hard soap, and syrup. Gamboge acts as a drastic hydragogue purgative, it causes vomiting and griping; it is seldom given alone, but combined with cream of tartar in cases of dropsy, or with calomel in cerebral disease. In large doses gamboge is a powerful irritant. causing inflammation of the alimentary canal, which may end fatally.