This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
The leaves and tops of Mentha viridis Linne (nat. ord. Labiatae).
Wild in Europe and North America; cultivated.
Leaves about 5 cm. long, subsessile, lance-ovate, acute serrate, glandular, nearly smooth; branches quadrangular, mostly light green; flowers in terminal, interrupted, narrow, acute spikes, with a tubular, sharply five-toothed calyx, a light-purplish, four-lobed corolla, and four rather long stamens; odor aromatic, taste pungent.
Dose, 5 to 15 m.; .30 to 1.00 c.c.
A volatile oil distilled from Spearmint.
A colorless, yellowish, or greenish-yellow liquid, becoming darker and thicker by age and exposure to the air, having the characteristic, strong odor of Spearmint, and a hot, aromatic taste. Sp. gr., 0. 930 to 0.940.
Freely in Alcohol.
Dose, 1 to 5 m.; .06 to .30 c.c.
Dose, 1/2 to 2 fl. oz.; 15. to 60. c.c.
2. Spiritus Menthae Viridis. - (See above).
These are the same as those of peppermint and oil of peppermint, but oil of spearmint is not so agreeable.