Oleum Gaultheriae (U. S. P.)—Oil of Gaultheria.
Preparation: Spirit of Gaultheria
Related entries: Salix Nigra.—Black Willow - Salix.—Willow - Methyl Salicylas (U. S. P.)—Methyl Salicylate - Betula Lenta.—Black Birch - Oleum Betulae Volatile (U. S. P.)—Volatile Oil of Betula - Gaultheria.—Wintergreen
"A volatile oil distilled from the leaves of Gaultheria procumbens, Linné (Wintergreen, Nat. Ord.—Ericaceae), consisting almost entirely of methyl salicylate (CH3C7H5O3=151.64), and nearly identical with volatile oil of betula. It should be kept in well-stoppered bottles, protected from light"—(U. S. P.).
SYNONYMS: Oil of wintergreen, Oil of teaberry, Oil of partridgeberry.
History.—This volatile oil is not peculiar to gaultheria alone, but has been derived also from the bark of Betula lenta, the root of Polygala paucifolia, and the stems and roots of Spiraea Ulmaria, Spiraea lobata, the leaves of Gaultheria hispidula, Gaultheria leucocarpa, Gaultheria punctata, and from Monotropa Hypopitys. Gaultheria procumbens is a small, herbaceous plant, growing in the United States along the Atlantic coast as far south as Georgia and Alabama, and westward as far as Minnesota. The oil was first distilled early in this century, in the states of Pennsylvania, New Jersey, and New York, but its production has gradually been superseded, to a great extent, by the distillation of the oil from Betula lenta, and later by the manufacture of artificial methyl salicylate, which is the chief constituent of both oils, a fact discovered almost simultaneously by Wm. Procter, Jr. (1842), and Cahours, in France (1844). Oil of gaultheria was first mentioned in American literature by Jacob Bigelow, in 1818 (see historical notes in Pharm. Review, 1898, p. 176; and especially Dr. Frederick Hoffmann, in Die Aetherischen Oele, 1899, p. 765).
Description.—"A colorless or yellow, or occasionally reddish liquid, having a characteristic, strongly aromatic odor, and a sweetish, warm, and aromatic taste. Specific gravity, 1.175 to 1.185 at 15° C. (59° F.). Boiling point, 218° to 221° C. (424.4° to 429.8° F.). It deviates polarized light slightly to the left. In other respects it has the same properties and conforms to the same reactions and tests as methyl salicylate (see Methyl Salicylas; also Oleum Betulae Volatile)"—(U. S. P.). Oil of gaultheria is the heaviest essential oil known. It dissolves in 6 parts of 70 per cent alcohol, which is not the case if the oil is adulterated with petroleum oil. An addition of the latter also reduces the specific gravity of the oil. Its odor distinctly differs from that of synthetic methyl salicylate. The only physical difference between the oils of gaultheria and sweet birch consists in the optical inactivity of the latter.
Chemical Composition.—According to Power and Kleber (Pharm. Rundschau, 1895, p. 228), 98.05 per cent of the oil consists of methyl salicylate, and may be removed by shaking the oil with solution of caustic potash (7.5 per cent); this converts the salicylate into the water-soluble potassium-methyl-salicylate (C6H4.OK.COOCH3). The remainder, a semisolid, insoluble mass, was differentiated into the paraffin triacontan (C30H62); an aldehyde or ketone, possessing the odor of oenanth-aldehyde; its corresponding alcohol (C8H16O); and an ester (C14H24O2), saponifiable into the same alcohol (C8H16O), and an acid (C6H10O2). Both alcohol and ester possess the characteristic odor of wintergreen not to be found in the artificial oil (Gildemeister and Hoffmann, loc. cit.). The terpene gaultherilene, observed by Cahours (1844) in the quantity of 10 per cent, must have been due to an adulteration of his specimen with oil of turpentine. Oil of gaultheria, according to recent investigations (see Oleum Betulae Volatile), is formed in the plant by decomposition of the glucosid gaultherin, under the influence of a peculiar ferment; but some oil, at least, must exist ready-formed, judging from the odor it emits when rubbed between the fingers.
Action, Medical Uses, and Dosage.—This oil is stimulant and aromatic, and is largely employed to correct or disguise the taste of other medicines. The essence, or the oil dissolved in alcohol, is stated to have been found effectual in curing intermittent fever. Oil of wintergreen possesses decidedly active properties, and in ½ ounce doses has produced death. It acts much like salicylic acid, but death is preceded by coma. Congestion of the kidneys, stomach, and duodenum, and black fluid blood, are revealed upon autopsy. The symptoms produced are drowsiness, cerebral congestion with throbbing of the arteries, delirium, visual impairment with contracted or dilated pupils, tinnitus, paresis, somnolence and coma. Oil of wintergreen has been more recently largely employed in gonorrhoea, and in gonorrheal and other forms of rheumatism, in trigeminal neuralgia, tic douloureux, and in subacute and chronic cystitis. As large doses as can be borne should be given in rheumatic disorders, but like salicylic acid and the salicylates its action upon the heart must be closely watched. Locally used, it relieves pain. The dose of the oil is from 5 to 10 to 30 drops on sugar, in capsules, or in emulsion.