Mentha piperita, Linne'. The dried leaves and tops with not mor than 2 p.c. of stems over 3 Mm. (1/8') thick, or other foreign organic matter.

Habitat. Asia, Europe, N. America; wild in low ground, wet places; cultivated in Japan, Germany, England, Michgan, New York, etc.

Syn. Menth. Pip.; Brandy (Lamb) Mint, Lammint, Herba Menthae Piperitae; Fr. Menthe poivree; Ger. Folia Menthae piperitae, Pfefferminzblatter.

Pi-pe-ri'ta. L. Piper, pepper -- peppery-mint -- i.e., from its aromatic burning taste.

Pep'permint -- pepper + mint -- i.e., mint with pepper properties.

Plant

Perennial herb, possibly from M. Hirsu'ta, Water Mint, by cultivation; rootstock creeping, producing long suckers by which it multiplies; stem square, purplish, .6-1.3 M. (2-4 degrees) high. Leaves, ovate-oblong, 1-9 Cm. (2/5-3 3/5') long, petiole 4-15 Mm. (1/6-3/5') long, pubescent, acute, sharply serrate, light green, purplish-brown, upper surface nearly glabrous, lower surface glandular-hairy, especially on veins; more or less crumpled and frequently detached from stems, which are quadrangular, 1-3 Mm. (1/25-1/8') thick, glabrous except for a few scattered deflexed hairs; flower-whorls in oblong (oval) spikes which are usually compact, or somewhat interrupted at base, 1-1.5 Cm. (2/5-3/5') broad rounded at summit, and in fruit 3-7 Cm. (1 1/5-2-4/5') long; bracts oblong-lanceolate, very acuminate, 4-7 Mm. (1/6-1/3') long, calyx tubular, equally 5-toothed, pubescent, glandular-punctate, often dark purplish; corolla tubular-campanulate, 4-cleft, 3 Mm. (1/8') long, often light purple; stamens 4, short; nutlets ellipsoidal, .5 Mm. (1/50') thick, blackish-brown; odor aromatic, characteristic; taste aromatic, pungent, followed by cooling sensation in the mouth. Powder, greenish -- leaf epidermis with wavy vertical walls, stomata, non-glandular hairs with papillose walls, glandular hairs with volatile oil and crystals, chlorenchyma, tracheae, parenchyma, pollen grains. Should be collected in dry weather, Aug.-Sept., when in bloom; strongest and most pungent of all mints. Solvents: alcohol; water partially. Dose, gr. 15-60 (1-4 Cm.).

Adulterations

Leaves chiefly of varieties of this species: (a) var. officina'lis--leaves narrower, spikes longer; (b) var. vulga'ris -- leaves broader, base more rounded, spikes more blunt and close; spearmint leaves, which may readily be distinguished from peppermint which has leaves with petioles, inflorescence thicker and more crowded, flowers larger with shorter calyx-teeth, and its own distinctive odor and taste.

Commercial

English is regarded best, Japanese is consumed chiefly for obtaining menthol (50-80 p.c.), while United States produces most.

Constituents

Volatile oil 1 p.c. (menthol), resin, tannin, gum, chlorophyll.

Oleum Menthae Piperitae. Oil of Peppermint, U.S.P. -- (Syn., Ol. Menth. Pip., Peppermint Oil; Fr. Essence de Menthe poivree; Ger. Pfefferminzol.). This volatile oil, distilled from the fresh, overground parts of the flowering plant and rectified by steam distillation, is a colorless liquid, strong penetrating odor of peppermint, pungent taste, followed by a senation of cold upon drawing air into the mouth; soluble in 4 vols. of 70 p.c. alcohol, showing not moe than slight opalescence and no separation of oil globules (abs. of dementholized or impure peppermint oil), sp. gr. 0.912, levorotatory; contains 16 constituents: at least 5 p.c. of esters, calculated as menthyl acetate, CHCO and 50 p.c. of total mentol, free and as esters; also acetic and isovaleric acids, acetaldehyde, isovaleric aldehyde, amyl alcohol, pinene, phellandrene, limonene, CH,  menthone, CHO, menthyl isovalerate, menthyl ester, cadinene, CH, a lactone, dimethyl sulphide; the hydrocarbons holding menthol dissolved are mainly the several terpenes (English -- pinene, phellandrene, sesquiterpene; Japanese -- sesquiterpene alone) with carvene odor, the higher boiling ones, (CH,having less pleasant odor; menthol and its esters (first 2 constituents) are most important, the others occurring in small quantities, being objectionable for flavoring and removed by rectification with steam.  Tests: 1. Distil oil 25 cc., collect the first 1 cc. and carefully superimpose it on 5 cc. of mercuric chloride T.S. -- no white film at zone of contact in 1 minute (abs. of dimethyl sulphide, found in non-rectified peppermint oils).  Should be kept cool, dark, in well-stoppered, amber-colored bottles.  Dose, mj-5 (.06-.3 cc.).

Adulterations

Oil of erigeron, castor oil, oil of turpentine, oil of copaiba, oil of camphor, oil of sassafras, alcohol; the first, second, and third prevent its solubility in equal volume of 80 pc. alcohol; the fourth gives buttery mass with sulphuric acid; oils of turpentine, camphor, and sassafras each render its action with iodine more violent, the two latter being red with nitric acid; dementholized oil (lower sp. gr.).

Menthol. Menthol, CHOH, U.S.P. -- Pipmenthol, Peppermint Camphor; Fr. Alcool Mentholique, Menthol Gauche, Camphre de Menthe; Ger. Mentholum, Pfefferminzkampfer, Mentha-kampfer.)  This is a secondary alcohol (stearoptene), obtained from oil of peppermint or other mint oils (Japanese and Chinese oil of peppermint -- M. Arven'sis var. Piperas'cens, M. canaden'sis var. glabra'ta).  It is obtained by subjecting the volatile oil simply to refrigeration at -22.2 degrees C. (-8 degrees F.), by means of ice and salt; when solidified the temperature is allowed to rise gradually, the liquid portion poured off from time to time, and the crystals deprived of oil by expression; may purify by recrystallization.  It is in colorless, acicular crystals, strong peppermint-like odor and taste, with a sensation of warmth followed by cold upon drawing air into the mouth; soluble in alcohol, chloroform, ether, petroleum benzin, liquid petrolatum, fixed or volatile oils, glacial acetic acid, slightly in water; alcoholic solution neutral, levorotatory; melts at 43 degrees C. (110 degrees F.); triturated with an equal weight of either camphor, phenol, thymol, or chloral hydrate -- mixture becomes liquid; distilled with PO yields menthene, CH, is a colorless liquid of pleasant odor.  Tests: 1. Heat 2 Gm. in open dish -- gradually volatilizes with residue .05 Gm. (abs. of wax, paraffin, inorganic substances).  2. Few crystals dissolved in glacial acetic acid 1 cc., + sulphuric acid 3 drops and nitric acid 1 drop -- not green (abs. of thymol).  Impurities: Wax, paraffin, thymol, magnesium sulphate, inorganic substances.  Should be kept cool, in well-closed containers.  Dose, gr. 1-2 (.06-.13 Gm.).

Preparations

Leaves And Tops

1. Spiritus Menthae Piperitae, Spirit of Peppermint.  (Syn., Sp. Menth. Pip., Essence of Peppermint; Fr. Alcoolat (Essence) de Menthe poivree; Ger. (Englische) Pfefferminz (-essenz)-spiritus.)

Manufacture

Macerate for 1 hour peppermint leaves 1 Gm. in 50 cc. of water, strongly express; mix oil of peppermint 10 cc. in alcohol 80 cc., add macerated leaves, and alcohol q.s. 100 cc., macerate mixture for 6 hours, frequently shaking, filter.  Should be kept in amber-colored bottles.  Dose, mx-30 (.6-2 cc.).

Preps.:  1. Elixir Catharticum Compositum, N.F., 1.4 p.c.  2. Liquor Phosphori, N.F., ½ p.c.  3. Mistura Rhei Alkalina, N.F., 4/5 p.c.  5. Mistura Rhei Composita, N.F., 3.5 p.c.  6. Syrupus Ficus Compositus, N.F., 3/10 p.c.

Oil

1. Aqua Menthae Piperitae.  Peppermint Water.  (Syn., Aq. Menth. Pip.; Fr. Eau de Menthe poivree; Ger. Pfefferminzwasser.)

Manufacture: 1/5 p.c.  Similar to Aquae Menthae Viridis, page 523.  Dose, 3ss-1 (15-30 cc.).

2. Spiritus Menthae Piperitae, 10 p.c.  3. Acetum Aromaticum, N.F., 1/20 p.c.  4. Cataplasma Kaolini,N.F., 1/20 p.c.  5. Elixir Euphorbiae Compositum, N.F., 1/10 p.c.  6. Gargarisma Guaiaci Compositum, N.F., 1/5 p.c.  7. Lavatio Ori, N.F., ½ p.c.  8. Linimentum Opii Compositum, N.F., 2.5 p.c.  9. Mistura Carminativa, N.F., 1/20 p.c.  10. Mistura Chloroformi et Morphinae Composita, N.F., 1/5 p.c.  11.  Oleum Hyoscyami Compositum, N.F. 1/5 p.c.  12. Pilulae Catharticae Vegetabiles, N.F., 1/8 m.  13. Pilulae Rhei Compositae, N.F., 1/18 m.  14.  Tabellae Sodii Bicarbonatis, N.F., 1/20 m.  MENTHOL: 1. Menthol Camphoratum, N.F., 47.5 p.c., + camphor 47.5, alcohol 5.  2.  Inunctum Mentholis, N.F., 5 p.c., + hydrous wool fat 95.  3. Inunctum Mentholis Compositum, N.F., 5 p.c., + methyl salicylate 10, hydrous wool fat 85.  4. Nebula Mentholis, N.F., 2 p.c., + light liquid petrolatum q.s. 100.  5.  Nebula Mentholis Composita, N.F., 1 p.c., + camphor 1, methyl salicylate 1/2, eucalyptol 1/5 oil of cinnamon 1/5, light liquid petrolatum q.s. 100.  6. Petroxolinum Mentholis, N..F., 10 p.c.  7. Dentifricium, N.F., 1/6 p.c.  8. Dentilinimentum Aconiti Compositum, N.F., 36 p.c.  9. Dentilinimentum Aconiti et Iodi Compositum, N.F., 2 -1/5 p.c.  10.  Linimentum Sinapis Compositum, N.F., 2 p.c.  11. Liquor Antisepticus, N.F., 1/10 p.c.  12. Liquor Pepsini Antisepticus, N.F., 1/20 p.c.  13. Nebula Aromatica, N.F., 1/5 p.c.  14. Pulvis Antisepticus, N.F., 1/10 p.c.

Unoff. Preps.:  LEAVES AND TOPS: Fluidextract, 3j-2 (4-8 cc.).  Infusion, 5 p.c., 3j-2 (30-60 cc.)  Syrup, 3j-4 (4-15 cc.).  Troches (each contains oil 1/7 m; .009 cc.).  MENTHOL: Plaster (Br.), 15 p.c., + yellow wax 10, rosin 75.

Properties

Carminative, stimulant, nervine, antispasmodic.

Uses

Spasmodic stomach and bowel pains, flatulency, nausea, cholera morbus, diarrhea, dysentery, colic, dysmenorrhea, nervous headache, hiccough, heart palpitation, vomiting, as a flavoring agent; externally the oil and menthol for rheumatism, neuralgia, toothache, antibacterial.