160. Mentha Pulegium, Linn.—Pennyroyal.
Sex. Syst. Didynamia, Gymnospermia.
(Herba florens recens et exsiccata. Oleum ex herba florente destillatum. L.—Herb, E. D.)
History.—This plant was employed in medicine by the ancient Greeks and Romans. It is the Γλήχων of Hippocrates [P. 359, &c. ed. Foes.] and Dioscorides, [Lib. iii cap. 36.] and the Pulegium of Pliny. [Hist. Nat. lib. xx. cap. 51, ed. Valp.]
Botany. Gen. Char.—See Mentha viridis.
Sp. Char.—Stem very much branched, prostrate. Leaves petiolated, ovate. Whorls all remote, globose, many-flowered. Calyxes hispid, bilabiate, villous in the inside of the throat (Bentham).—Creeping-rooted.
Hab.—Wet commons and margins of brooks. Indigenous. A native of most parts of Europe, of the Caucasus, Chili, and Teneriffe.
Properties.—The herb with the flowers (herba seu summitates pulegii) is employed in medicine. It has a strong, but peculiar odour; a hot, aromatic, bitter taste, followed by a feeling of coolness in the mouth. Sesquichloride of iron causes a green colour (tannate of iron) with the cold infusion of pennyroyal.
Composition.—Its principal constituents are volatile oil, a bitter matter, resin? tannic acid, and woody fibre.
Physiological Effects.—Its effects are analogous to the other mints. Emmenagogue and antispasmodic properties are ascribed to it by the public, and formerly by medical practitioners.
Uses.—A popular remedy for obstructed menstruation, hysterical complaints, and hooping-cough. Barely employed by the professional man. The following are its officinal preparations, with their uses:—
1. OLEUM MENTHAE PULEGII, L.E.D.; Oleum Pulegii, offic.; Oil of Pennyroyal.—(Obtained by submitting the herb to distillation with water.)—It has a pale colour, a warm taste, and the peculiar odour of the herb. It boils at 395° F. Its sp. gr. is 0.925; and is composed, according to Dr. Kane, of C10H8O. The fresh herb yields from 1-120th to 1-100th of its weight of oil. [Brande, Dict. Mat. Med. p. 357.] It is stimulant and carminative, and is used, as an antispasmodic and emmenagogue, in doses of from gtt. ij to gtt. v, taken on sugar.
2. SPIRITUS MENTHAE PUEGII, L.; Spiritus Pulegii; Spirit of Pennyroyal.—(Prepared with Oil of Pennyroyal, as the Spiritus Menthae viridis.)—Usually prepared by dissolving the oil in spirit. Stimulant and carminative. Employed as an antispasmodic and carminative. Dose, fʒs to fʒij.
3. ESSENTIA MENTHAE PULEGII, D.; Essence of Pennyroyal—(Oil of Pennyroyal f℥j; Rectified Spirit f℥ix. Mix with agitation, D.)—May be given in doses of from gtt. x to gtt. xx.
4. AQUA MENTHAE PULEGII, L. E. D.; Aqua Pulegii, offic.; Pennyroyal Water.—(Prepared with the herb or oil, like Aqua Menthae viridis.)—Carminative and stomachic. Dose, f℥j to f℥iij.
The liquid sold in the shops as Pennyroyal and Hysteric Water is prepared by adding f℥ss of the compound spirit of bryony to Oss of pennyroyal water.