Botanical Source and Description.—This oil is obtained by distilling the plant Erechtites hieracifolia with water. Thus obtained, it is quite fluid, transparent, yellowish, of a strong, peculiar, fetid, and slightly aromatic odor, and a fetid, bitterish, burning taste. In its odor and taste it somewhat resembles the oil of fleabane. It is soluble in ether, alcohol, and partially in acetic acid; its specific gravity, according to Prof. Power (Pharm. Rundschau, Vol. V, 1887, p. 201), is 0.838 at 18.5° C. (65.3° F.). According to Beilstein and Wiegand (1882), its chief constituent is a terpene (C10H16), boiling at 175° C. (347° F.). The oil of commerce is liable to be mixed with oil of fleabane (see Oleum Erigerontis; also see A. M. Todd, Amer. Jour. Pharm., 1887, p. 302, and Drugs and Med. of N. A., Vol. II, pp. 126-140).
Action, Medical Uses, and Dosage.—The therapeutical action of oil of fireweed is not well understood. It seems to resemble the oil of fleabane in its influence upon various hemorrhages, and for which agent it is frequently substituted, and is considered by many to be the most efficient in such cases, of the two oils. It also exerts a beneficial effect on mucous surfaces, and has been successfully used in diarrhoea, dysentery, hemorrhoids, etc. As an antispasmodic it has been found of value in spasms of the stomach and bowels, colic, hiccough, hysteria, and pertussis, though it is apt to disagree with the stomach, causing nausea, etc. It is chiefly employed for the same purposes as the oil of fleabane. The dose is from 5 to 20 drops on sugar, or in emulsion. When triturated with the extract of stramonium, oil of fireweed is said to form a valuable preparation for piles.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.