part n. Materia Medica. — Mentlw. viridis.

38.3

Species 1. Melissa officinalis. ' Officinal or Common Balm. Med.

Bot. 2d edit. 335. t.l\9.Officinal. Melissje" officinalis folia, Edin. Balm leaves.

Syn. Melissc {F.) t Helisse (O.), Melissa (L), Balsamina (S.).

Balm is a perennial plant, a native of the south of Europe,growing in mountainous situations, and flowering from Julyto September. It is cultivated in our gardens. l The root isfibrous, and sends up annual stems, which rise about two feethigh, and are branched, quadrangular, and smooth. The leavesare opposite in pairs, of a bright green colour, ribbed, deeplyserrated, and cordate; the lower ones on long footstalks, andthe upper nearly sessile. The flowers, which are in small axil-lary bunches forming semi-whorls, stand on slender ped&ncles,at the base of which are small, oblong, notched, hairy bractes.The calyx is tubular and pentangular; the upper lip tridentate ;the lower shorter, and cut into two acute teeth. The corolla,which is tubular, of a yellowish white colour, with the upper lipshorter, and notched, and the lower three-cleft, encloses theanthers: the seeds are four, ovate, and placed at the bottom ofthe calyx.

For medicinal use the herb should be cut before it flowers,as it is then more odorous.

Qualifies ___The recent plant has the agreeable odour of le-mons, which is lost in drying; and an austere, slightly aromatictaste. In distillation with water, it yields a small portion of ayellow essential oil, on which its odour depends. The wateryinfusion tastes rough; reddens slightly litmus paper; andaffords with oxysulphate of iron a deep olive, with nitrate ofsilver a deep brown, and with superacetate of lead a copiousgreenish white precipitate.

Medical properties and uses. —Officinal balm is stomachicand diuretic. It was formerly prized as a corroborant in hy-pochondriacal and nervous affections; but it is now used onlyin the form of tea, as a grateful diluent in fevers.

MENTHA. Spec. Plant. Willd. iii. 74.CI. 14. Ord.l. Didynamia Gymnospermia. Nat.ord. Verticillatae,

Linn. Labiatae, Juss.G. 1102. Corolla not quite equal, four-cleft; the broader segment

emarginate. Stamens upright, distant.

* Spiked.

Sp. 7. M. viridis. Spearmint. Smith (spec. 3.) Flora Brit. 612.Med. Bot. 2d edit. 338. f. 121.

* * Capitate.

Sp. 13. M. piperita. Peppermint. Smith (spec. 4.) Flora Brit. 613.

Med. Bot. 9,dedit. S36. 1. 120. Eng. Bot. 461.*** Verticil/ate.

1 M€Kt(rtro<f>if\\oif Dioscoridis; bees being very fond of it.° It was cultivated by Gerardcin 1596.

1 b