Active Ingredients. - The source of the physiological activity of gamboge is still a puzzle. The only active ingredient which has yet been identified is gambogic acid, C20H14O4, which, according to Christison, exists to the extent of 72 per cent. in the purer (pipe) gamboge, the remainder being made up by 23 per cent. of gum and 5 per cent. of water. But it has been distinctly shown by Christison himself, and by Pabo, that gambogic acid is not so active as gamboge itself; so that there is some yet unsolved mystery behind. It may be suggested, as a possible explanation, that the compound of gambogic acid and gum is more hygroscopic than the pure acid.

Physiological Action. - The general physiological action of gamboge is that of a powerful, but at the same time rather uncertain, irritant of the alimentary canal. Taken in small doses, it increases the secretions of the alimentary canal and the frequency of the stools; and it is said by Abeille that if the small doses be gradually increased up to 20 grains daily, all purging ceases, and a copious diuresis takes its place. Given in single doses of from 3 to 5 grains, it causes nausea (sometimes bilious vomiting), colicky griping, tenesmus, and watery evacuations, and has also been said to increase the urine. But it is certain that a good deal of what was formerly stated about the amount of water discharged from the bowels and kidneys in consequence of the administration of gamboge was erroneous: in regard to the stool, it has been distinctly proved by Radziejewsky that there is no more water in stools produced by gamboge than in those that follow the use of croton oil. Taken in larger doses, gamboge produces actual inflammation of the intestines; the violent abdominal pain, vomiting, and purging are followed by collapse and death; such cases have been repeatedly recorded. Christison 1 quotes a fatal case (the dose was a drachm) from a German source: and mentions Morrison's quack pills, which contain (or then contained) gamboge, as a source of this danger. He cites several trials and inquests, in which death had resulted from inflammation produced by these pills, and in the latter it seemed probable that gamboge was the fatal ingredient.

At the same time, Christison mentions the very curious fact that certain constitutional states seem to fortify the body against the more violent effects of gamboge. Rasori and his followers, in Italy, used to give drachm doses in inflammatory diseases with no other result than brisk purging; and Linoli gave it in inflammatory dropsy in increasing doses up to the extraordinary amount of 850 grains in twelve days, and 1,044 in a month. Christison might also have quoted Rayer, who gave gamboge to the extent of nearly 40 grains daily, for six weeks together, in cases of dropsy, without injury. It would be exceedingly rash, however, to presume upon any such facts, to which we do not at present possess the clue, for the general administration of gamboge: and, in fact, very moderate doses have been known to produce unexpectedly violent effects. As already stated, these effects consisted in violent inflammation of the bowels; this was evinced, after death, by redness, ulceration, and even gangrene of the mucous membrane.

1 On Poisons, p. 603.

Therapeutic Action. - The position of gamboge in medicine is unsatisfactory. On the one hand, its known irritant properties make it a dangerous and improper medicine in any case where there is likelihood of the existence of intestinal inflammation or congestion, or any tendency to uterine haemorrhage. And, on the other hand, it has now been proved that although gamboge is more irritant than jalap, scammony, or colocynth, it is by no means so hydragogue as was formerly supposed. On the whole, considering the great superiority of elaterium as a hydragogue cathartic, and of digitalis and bitartrate of potash as diuretics, there hardly seems any place left for gamboge in the treatment of dropsical affections.

In Dysentery. - It would appear, however, that there is one very different application of gamboge which is really of much use. Malgaigne and Betz found the use of very small doses (about 3/4-grain in twenty-four hours) to be exceedingly valuable for dysentery, especially in young persons; - an apparently paradoxical fact, but established on good evidence, and, after all, not more strange than the completely opposite action of small and large doses of strychnia, and of many other drugs.

Preparations and Dose. - Gambogia, gr. j. - iv. (.06 - .25); Pilulae Cath. Comp. (No. 1 - 3.)