The Physiomedical Dispensatory by William Cook, M.D., 1869
Description: Natural Order, Labiatae. Generic characters as in the mentha piperita. Stems usually in tufts, from one to two and a half feet high, square, green, (not purple, as in peppermint.) Leaves almost sessile, oval lanceolate, incisely serrate, much lighter green than in peppermint. Flowers forming long (not blunt) terminal spicate whorls, slender, loose, and interrupted. Corolla light-purple, nearly white.
This plant, like peppermint, is common in wet places and along water courses. Distillation yields a free quantity of volatile oil, which is at first scarcely tinted yellow, but by age becomes yellowish-green. This oil has some of the aroma peculiar to oil of peppermint, but lacks its penetrating pungency.
Properties and Uses: Spearmint is largely relaxant, of the distinctly antispasmodic order; and though usually supposed to be identical with peppermint, is widely different from that article, and much more soothing and acceptable to the stomach. It is admirable for allaying nausea and vomiting, and relieving the colics of children; but is not so strongly carminative as peppermint, nor of so much use in spasmodic troubles. Its action is quickly diffused throughout the nervous system, especially influencing the nervous peripheries, while it at the same time promotes a free discharge of the watery portions of the urine. These qualities make it an agent of much service in sudden cases of nervousness, and hysteria of a mild form; and it may be used as a common drink in nervous forms of fever, and in recent suppressions of urine. Its whole influence is soothing; and though but transient, is admirable for a large variety of light and acute cases. If the stomach is nauseated, it may be given in quite small quantities of a very weak infusionas a drachm to a pint, given in doses of a tablespoonful or less every fifteen or ten minutes, which rarely fails to arrest sympathetic vomiting; and is excellent for quieting the stomach after an emetic, and after the acuteness of a cholera morbus has been relieved. Being so largely relaxant, a too strong infusion may prove objectionable to most persons; and occasionally a patient is met who can not endure its taste at all. Two drachms to a pint make an infusion of suitable strength for most cases. When used for hysterical or other nervousness, it may be combined in smaller quantities with ginger.
The oil possesses the pleasant relaxing virtues of the herb, and is used for the same general purposes, though not always so agreeable as the infusion. It makes an excellent external application in the form of liniments; and will be found of much service over painful and neuralgic parts, especially over the spine and the large nerves when irritated. Combined with lobelia tincture and oil of rosemary, it forms, an admirable nervine liniment; and may be combined with similar agents in lard to make a nervine ointment. For inward use, it is commonly prepared as an essence, or in medicated water.
Medical Herbalism journal and medherb.com