Oleum Menthae Viridis. U. S., Br. Oil of Spearmint.

Ol. Menth. Vir. [Spearmint Oil]

Related entry: Spearmint - Oil of Peppermint

"A volatile oil distilled from the flowering plant of Mentha spicata Linné (Mentha viridis Linné) (Fam. Labiatae), and yielding not less than 43 per cent., by volume, of carvone [C₁₀H₁₄O = 150.11]. Preserve it in well-stoppered, amber-colored bottles, in a cool place, protected from light." U. S. "Oil of Spearmint is the oil distilled from fresh flowering spearmint, Mentha viridis, Linn., or mentha crispa, Roth." Br.

Huile volatile (Essence) de Menthe verte, Fr.; Römisch-minzöl, Krauseminzöl, G.

According to Lewis, ten pounds of spearmint yield an ounce of oil; by others the product is stated not to exceed one part from five hundred. The oil is largely distilled in this country, the whole plant being used. It is pale yellow or greenish when recently prepared, but becomes red with age, and ultimately almost of a mahogany color. It is officially described as "a colorless yellow or greenish-yellow liquid, having the characteristic odor and taste of spearmint. It is soluble in 1 volume of 80 per cent. alcohol, forming a clear solution; on further dilution, it usually becomes cloudy. Specific gravity: 0.917 to 0.934 at 25° C. (77° F.). The optical rotation varies between -38° and -55° in a 100 mm. tube at 25° C. (77° F.).

The peculiar odor of spearmint oil has not yet been definitely associated with any of its constituents. It was for a time thought to be due to an acetic derivative of dihydrocuminyl, but this has recently been denied so far as the oil of American origin is concerned.

Dose, one to six minims (0.06-0.4 mil).

Off. Prep.—Aqua Menthae Viridis, U. S., Br.; Spiritus Menthae Viridis, U. S.

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.