A concrete oleoresin obtained by incisions, the source of which has not been determined, though thought to be from Canarium commune, Linné (Nat. Ord.—Burseraceae).
SYNONYMS: Resina elemi, Gummi elemi, Manila elemi.
ILLUSTRATION: Bentley and Trimen, Med. Plants, 61.

Botanical Source and History.—Several resinous bodies have at various times been placed in the European market under the name Elemi, all of which are believed to have been the products of plants of the natural order Burseraceae. The British Pharmacopoeia recognizes a product from the Philippine Islands known as Manila elemi, thought to be derived from the species above named.

Description.—Manila elemi, when recent, occurs in transparent, soft, granular masses, consisting of a solution of solid resin in essential oil. Externally it has a light, canary-yellow color, and, as found in commerce, is largely solidified, presenting an opaque and granular fracture, due to the crystallization of the resin. Chips and other foreign substances are often found in the solid fragments. When wetted with a little alcohol, elemi readily disintegrates, showing a multitude of small, crystalline needles. It melts easily, a transparent fluid resulting. It has an aromatic, warm, acrid taste, and a fragrant odor, resembling that of the terebinthinates, the drug in many respects closely resembling the latter class of substances. It is insoluble in water, partly soluble in cold, and completely soluble in hot alcohol; easily soluble also in oil of turpentine and ether.

Chemical Composition.—A neutral volatile oil, strongly dextrogyrate, colorless, and fragrant, was obtained to the extent of at least 10 per cent by the authors of Pharmacographia. Deville, on the other hand (1841), found oil of elemi to be laevogyre. Maujean (1821) found in this drug two resinous bodies—one soluble in cold spirit, the other in hot spirit only. The principal constituent of the drug is the part soluble in cold alcohol. It is an amorphous, non-acid resin. The part insoluble in this solvent is a crystalline magma, soluble in hot alcohol, which, upon cooling, yields 25 per cent (of the original elemi) of a crystallizable resin, called amyrin by Baup (1851). It is also soluble in ether, chloroform, and carbon disulphide. Ciamician, in 1878, distilled it from zinc dust, obtaining toluene, methyl-ethyl-benzene, and ethyl-naphthalene. Vesterberg (1887) differentiated amyrin into two isomers of the formula C30H48.H2O, derived from two isomeric hydrocarbons (C30H48) of the melting points 135° C. (275° F.) and 194° C. (381.2° F). Buri (1874), from the mother-liquors of amyrin, obtained a small quantity of an acid, which he called elemic acid (C35H46O4). It forms large crystals, melts at 150° C. (302° F.), is insoluble in water, soluble in alcohol, ether, and amyl alcohol. Bryoïdin is a crystallizable, neutral substance, observed by Baup in the residual aqueous liquid obtained by the distillation of a mixture of water and the essential oil. It is soluble in hot water and crystallizes upon cooling. Flückiger purified it by sublimation in a current of carbonic acid and found its composition to be (C10H16)2.3H2O, and its melting point 133.5° C. (271.5° F). Dry hydrochloric acid gas causes bryoïdin to undergo changes of color ranging from red to violet, blue and green. Amyrin remains unchanged under similar treatment. A bitter principle, already observed by Bonastre (1824) was obtained by Flückiger in the mother liquors of bryoïdin, in the form of a soft, resinous mass (Flückiger, Pharmacognosie, 1891).

Action, Medical Uses, and Dosage.—This agent closely resembles the turpentines, and undoubtedly might be substituted for them. The action of its oil and oil of turpentine are also similar. Elemi is, however, only used in European medicine externally, in plaster and ointment form, as a dressing for burns, indolent sores, etc.

Related Products.—BRAZILIAN ELEMI. The product of several species of Icica. A greenish-yellow, fragrant, translucent resin, sometimes opaque, whitish-gray or yellowish. It is composed of small needles. The odorous resin exuding from the trunks of species of Icica (e. g., I. Icicariba, De Candolle. is consumed as incense in the churches of French Guiana (P. L. Simmonds, Amer. Jour. Pharm., 1895, p. 253).

MEXICAN ELEMI. Vera Cruz elemi.—The product of Amyris elemifera of Royle;also of Elaphrium Jacquinianum (Bursera tomentosa) and E. elemifera (Amer. Journ. Pharm, 1895, p. 253). Occurs in opaque (sometimes translucent) fragments or semi-cylindrical pieces, is pale-yellow or nearly white, and has an agreeable odor. It may be readily masticated. Treatment with cold alcohol reveals white needles, probably of amyrin.

MAURITIUS ELEMI.—The product of Colophonia Mauritiana, De Candolle. Mauritius. When fresh this is a liquid, but subsequently hardens, and finally resembles the Manilla product, especially in the abundance of residual amyrin crystals by treatment with cold alcohol.

AFRICAN ELEMI, or ORIENTAL ELEMI. Lubân meyeti, Lubân mati.—Exudes from Boswellia Frereana, Birdwood. Occurs in tears, fragments, or large stalactitic pieces, whose fracture is shell-like, exhibiting a transparent, amber-yellow interior. It is encrusted with a thin, opaque crust. The thin, paper-like, brown bark may be found adhering to the masses. The taste is mildly terebinthinous, while the odor is said to be agreeable., resembling a mixed odor of turpentine and lemon. Alcohol practically dissolves it. It was found to be a mixture of a dextrogyrate terpene (C10H16), and a probably laevogyre oxygenated oil (Pharmacographia).

OIL OF MEXICAN LIGNALOES is yielded by the wood of Bursera delpachiana. It has the combined fragrance of lemon and jasmine.

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.