The bark of the root of Dirca palustris.—U. S.
Dose.—The dose of the pulverized bark of the root, as an emetic, is from gr. v. to x. As an expectorant in asthma it may be given in doses of a tincture from grs. iij. to v. every two or three hours. The decoction is expectorant and sudorific and may be made by adding ℥j. of the bark to Oj. of boiling water; let it stand where it will keep hot for an hour. Dose, ℥j. to ℥ij.
Therapeutic Action.— This agent is recommended in intermittent fever, asthma, chronic bronchial affections, etc., but as yet has been little used. In doses of from five to ten grains, it produces vomiting, preceded by a sense of heat and burning in the stomach, and followed by purging.
When the recent bark is applied to the surface, it produces redness, irritation, and finally vesication; but it is too slow as an epispastic to be of any importance.