Elemi is an oleoresin, obtained from Canarium commune, Linn. (N.O. Burseraceae). It exudes naturally from the bark of the tree, but its flow is increased by incising the tree and applying heat. It is probably liquid when quite fresh, but gradually solidifies to a crystalline, honey-like mass, in which state it usually arrives in this country from Manila. When fresh, the oleoresin is pale yellow in colour, soft, granular, and opaque, somewhat resembling crystallised honey. On keeping it becomes firmer, yellower, and more transparent. When examined under the microscope it is found to contain numerous acicular crystals. The odour is fragrant, recalling that of mace; the taste is pungent and bitter. The term elemi is applied to a variety of substances having certain physical properties in common. These varieties are named according to their geographical sources. Brazilian elemi is said to be obtained from Icica Icariba, DC.;Mexican, from Amyris elemifera, Linn..?); Mauritius, from Canarium Mauritianum, Blume.
Soluble in ether, almost entirely soluble in alcohol, partly soluble in petroleum spirit.
Constituents.—The chief constituents of Manila elemi are volatile Oil (20 to 30 per cent.), and resin. The volatile oil (specific gravity, 0.87 to 0.91) consists chiefly of terpenes. The resinous portion contains α- and β-manelemic acids (soluble in ammonium carbonate solution), α- and β-manamyrin (insoluble in ammonium carbonate solution, or in alcohol), maneleresene (insoluble in ammonium carbonate solution, but soluble in alcohol), bryoidin, and a bitter principle; α- and β-manamyrin and α-manelemic acid are crystalline, and the last-mentioned forms crystalline salts. Bryoidin is an acrid, bitter, crystalline substance, readily soluble in alcohol, and crystallising from hot water.
Action and Uses.—Elemi is used externally in the form of ointment as a local stimulant to ulcers and chronic skin diseases. Its properties are similar to those of turpentine, in which it is sometimes Ordered to be dissolved before mixing with the ointment base.
- Unguentum Elemi, B.P., 1885.—ELEMI OINTMENT.
- Elemi, 20; simple ointment, 80. Melt the elemi and simple ointment together, strain through flannel, and stir constantly until the ointment solidifies. Elemi ointment was formerly employed as a stimulant application to ulcers.