ART II.

Materia Medica.

211

a deep green colour on the upper surface, and on the underreticulated, tomentose, and whitish : the radical ones are peti-olate, but those of the stem sessile and embracing. The flowersare terminal, solitary, large, and of a golden colour. Thecalyx is scaly; the exterior scales are large, ovate, imbricated,and externally tomentose; the interior are narrow, linear, equal,and chaffy. The florets of the ray are numerous, spreading,twice the length of the calyx, linear, with the apex tridentate.The anthers end in two bristles at the base. The seeds arequadrangular, smooth, slightly curved, and furnished with asomewhat chaffy pappus. The receptacle is reticulate andpapillous.

The roots of elecampane found in the shops, are generallyobtained from garden plants. They are fit for use in the se-cond year of their growth ; and at this age are preferable tothe older roots, which become stringy and woody. Theyshould be dug up in autumn.

Qualities. — Elecampane root when dry has an aromatic, yetslightly foetid odour; and when chewed, the taste is at firstdisagreeable, glutinous, and in some degree resemblingthat of rancid soap; then aromatic, bitter, and hot. Bothwater and alcohol extract its virtues: the tincture possessingmore of the bitterness and pungency of the root than the wa-tery infusion. The decoction, after standing some hours, de-posits a white powder resembling starch in appearance; but itsproperties show it to be a distinct principle ; and it has there-fore been named imdin. 1 In distillation with water this rootyields a concrete flaky substance, which seems to hold an inter-mediate place between camphor and volatile oil in its nature."

Medical properties and uses. — Elecampane is usually rankedas a tonic; and supposed to possess deobstruent, diuretic, andexpectorant properties. It was formerly regarded as a remedyof great efficacy in dyspeptic affections, flatulencies, palsy,dropsies, uterine obstructions, and pulmonary complaints :but Cullen observed, that its diuretic powers were trifling;and could not discover that it possessed any expectorant pro-perties. 3 It is scarcely ever used by the regular practitioner.The dose of the powdered root may be from 3j to 3j.

IRIS. 4 Spec. Plant. Willd. i. 224.CI. 3. Ord. 1. Triandria Monogynia. Nat. ord. Ensata lArm.

Iridae Juss.

1 This substance which was first noticed, and its properties investigated, by Rose ;was named by Dr< Thomson, System of Chemistry, 4th edit. iv. 697.

- Nettman's Chem. by Lewis, 2d edit. ii. 216 3 Mat. Med. ii. 459.

4 " Iris a coelcstis arcus similitudine nomen obtinuit." Jjiosmrides.

t» 9.