Gamboge
2 of the 7 encyclopedias on this shelf carry an entry for Gamboge. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
Important: Safety Warning This page presents medical treatment from an era before modern medicine. The remedies described are ineffective against the conditions named, and some of the ingredients or doses are harmful. Do not use them to treat any illness; consult a qualified medical professional. This information has been left in for historical purposes but should not be acted upon. or CAMBOGE (a corruption of Cambodia, the name of the district in Annam where it is found), 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, variety pedicellata, a tree belonging to the order Guttiferæ, growing in Cambodia, Siam, and the S. 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. 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 Hebradendron gambogioides. In pharmacy, gamboge is used in the preparation of Pilula cambogiæ compositæ, compound gamboge pill, composed of gamboge, Barbados 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 diseases.
Aiton's Encyclopedia (1910)
gam-boj', a common resin derived from a tropical, laurel-like tree of the East Indies. Commercial gamboge comes chiefly from Siam and Cochin China. The name is derived from Cambodia. Like turpentine, it is obtained by making a cut in the trunk of the tree, and collecting the bright yellow juice as it falls. The natives catch it in joints of the bamboo. They allow it to harden naturally, or else dry it over a fire. It is sent to market either in bamboo canes or in cakes. The former is preferred by reason of its greater purity. Gamboge has been used from time immemorial as a pigment to produce a bright yellow color in painting. Physicians prescribe it also as a remedy for tapeworm and other intestinal difficulties. An overdose is a deadly poison. See Gum