Be Candolle. Cl. 5. Ord. 2. Pentandria Digynia. Nat. ord. Umbelliferae. G. novum. Fruit elliptical, compressed, flat. Petals involute, entire. Species -. O. Chironium.4 Opoponax, or Rough Parsnep. Med.

Bot. 3d edit. 122. t. 47. Officinal. Opoponax, Lond. Dub. Opoponax.

Sijn. Opoponax (F.), Pannax gummi (G.), Opoponace (I.), Opopanaco (S), Gawsheer (Pers.), Iawesheer (Arab.).

This is a perennial plant, a native of the south of Europe, flowering in July. The root is as thick as the human arm, branched, of a yellow colour, and covered with a tuberose bark: the stem rises about five feet in height, the thickness of a man's finger, round, striated, scariose at the base, angular at the summit, and shining: the radical leaves are simple, cordate, and crenated; those of the stem, ternate, and quinate, with the terminal leaflet cordate and very large: the whole are petiolate; the petioles sheathing, and the leaflets hairy on the under surface; the umbelliferous branches are very smooth; first alternate, erect; then two, three, or four together, in a sort of whorl, two or three inches long, with one or two spathaceous leaflets towards the middle or at the top; the universal umbels have seven or eight rays, an inch long, of a yellowish-green colour : both the involucres and involucels consist of from four to six very short leaflets, frequently permanent. The fruit is flat.

1 Reflections on the Commerce of the Mediterranean, p. 64.

2 Lord Bacon, speaking of Inunction, says,-"Ante omnia igitur usum olei vel olivarum vel amygdali dulcis, ad cutem ab extra unguendum, ad longaevitatem conduccre cxistiinamus." Opera, fol. 1665. p. 536.

3 The nostrum called Roche's Embrocation, for hooping-cough, consists of olive oil, with about half its quantity of the oil of cloves and oil of amber.

Dioscoridis.

In the Levant, where this plant grows, the milky juice which exudes from incisions made in the roots, and dried in the sun, forms the opoponax of the shops. That which is obtained from plants grown in France contain scarcely any resin. It is imported from Turkey and India in chests, and is sometimes in tears or drops, but more usually in irregular lumps.

Qualities.-Opoponax has a strong disagreeable smell, and a bitter, acrid taste. The masses are of a reddish-yellow colour, speckled with white on the outside, paler within, and frequently variegated with large white pieces. Its specific gravity is 1.622.1 It appears to be a compound of gum 33.40, resin 42, starch 4.20, extractive 1.60, wax .30, malic acid 2.80, a trace of caoutchouc, essential oil 5.90, and woody fibre 9.80 in 100 parts.2 When triturated with water, about one half of it dissolves, forming an opaque, milky solution, which deposits on standing a portion of resinous matter, and becomes yellowish. Alcohol acts feebly on it; and in distillation, either with spirit or with water, the odour of the opoponax is very strongly comniunicated to the fluids, but scarcely any oil is obtained in a separate state.

, Medical properties and uses.-This gum resin is regarded as antispasmodic and emmenagogue, and as such has been used in hysteria and chlorosis; but it is very seldom ordered. The dose may be from grs. x. to 3ss.