This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
Cambogia - Gamboge. - A gum-resin obtained from Garcinia Morella. Imported from Siam.
Characters. - Cylindrical pieces, breaking easily with a smooth conchoidal glistening fracture; colour tawny, changing to yellow when it is rubbed with water; taste acrid.
Dose. - 1 to 4 gr.
Impurity. - Starch; detected by yielding a green colour with iodine.
Composition. - Gamboge contains about 73 per cent. of a resinous substance, gambogic acid, C20H13O4; 25 per cent. of gum; and about 2 per cent. of water. Gambogic acid is insoluble in water, gives the brilliant yellow colour to the gum-resin, and forms salts with bases. It is less active than the gum-resin.
Pilula Cambogiae Composita. - Gamboge, 1; Barbadoes Aloes, 1; Compound Powder of Cinnamon, 1; Hard Soap, 2; Syrup, q. s. Dose, 5 to 10 gr.
Gamboge is an irritant to the stomach and bowels, causing vomiting in large doses, and in medicinal doses acting as a hydragogue cathartic not unlike colocynth, without being cholagogue. It is seldom prescribed alone, and not often as the compound pill. Such a remedy is indicated in dropsies, cerebral hyperaemia, and as an anthelmintic (not to children); but other substances have now almost completely displaced it.
Gambogic acid is chiefly thrown out in the liquid faeces; but part is absorbed, passes through the blood and tissues, and is excreted by the kidneys. These it stimulates, causing an increased flow of yellow-coloured urine. Its diuretic effect may add to its value in dropsy.