Tonga.—Tonga Bark is a composition of unknown barks compounded by the natives of the Feejee Islands for medicinal purposes. The plants from which this remedy is derived are believed to be Premna taitensis Schau. (Fam. Verbenaceae), and Epipremnum mirabile Schott. (Fam. Araceae.) According to Moeller (Ph. Centrh.), the latter is not a source of tonga. (A. J. P., 1881, 439.) It was introduced to the notice of the medical profession by Sydney Ringer and Wm. Murrell, of London, as a remedy for neuralgia. (L. L., ii, 1880.) Merck reports the presence of tongine and a volatile oil in tonga. (Merck's Index, 1907.) The natives are said to steep the bundle as prepared by them for twenty minutes in half a tumberful of cold water, and then, squeezing it dry, drink the infusion, preserving the bundle in a dry place for further use. A fluidextract has been put upon the market, and evidence of its value brought forward, but we have known a fluidrachm of this extract to be given every two hours for two days without obvious effect; the dose usually recommended is half a fluidrachm (1.8 mils).
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.