Spec. Plant. Willd. ii. 1133. Cl. 5. Ord. 1. Pentandria Monogynia. Nat. ord. Rutaceae. G. 426. Corolla consisting of five petals. Nectaries five above the germen. Caps, three to five, united. Seeds calyptrate. Spec. 22. D. crenata. Crenated Diosma. Med. Dot. Sd edit.

Thunberg, Prod. 43. N. G. Agathama, Willd. Bucco, Wendland. Officinal. Diosma, Lond. Diosma crenata. Folia. Buchu,

Dub. Buchu-leaves.

Syn. Buchu, Bocchoe (Hottentoi).

This species of Diosma is a native of the Cape of Good Hope. The leaves are borne on the extreme twigs, nearly in a verticillated order; they are petiolate, coriaceous, alternate, sometimes opposite; ovato-lanceolate, nearly pointed, about an inch in length and half an inch in breadth, with the margin crenated; the upper surface is smooth, and of a beautiful bright green; the under is pale, and spread, with many translucent glandular points. The flowers are axillary, solitary, and have the leaflets of the calyx awl-shaped and crenated.

Qualities.-The dried leaves, to an inexperienced eye, might readily be mistaken for those of senna. The short petiole which remains attached to them is channelled : the upper surface is smooth, shining, and of a yellowish olive hue; the under surface is rugose, pale, and studded with large open glands, with an excretory pore in each. The leaves are generally mingled with reddish brown twigs, mottled near the apex with bright yellow, and notched from the separation of the leaves. The whole exhales a powerful, not unpleasant aromatic odour: the taste impressed on the tongue by chewing the leaves, at first resembles that of peppermint; but when chewed for some time, a pungency and sweetness are left on the tongue. These properties are imparted both to boiling water and to proof spirit. According to the analysis of M. Felix Cadet de Gassicourt, Buchu leaves yield of volatile oil 0.665 parts, gum 21.17, extractive 6.17, chlorophylle 1.10, and resin 2.151. Their active principles seem to depend on the volatile oil and the extractive.

Medical properties and uses.-Buchu leaves are excitant, sudorific, and diuretic. They have been employed for some years both in England and Germany; but, in Britain, have been admitted only lately into the London and the Dublin Pharmacopoeias. They have been found useful in rheumatism, particularly when it assumes an intermittent character; in chronic catarrh; and in chronic inflammation of the bladder, and retention of urine. They are given in the form of infusion, made with half an ounce of the leaves to half a pint of boiling water.1 The dose is from ten fluid drachms to a fluid ounce and a half, taken once in four hours.

Officinal preparations.-Infusum Diosma, L. Infusum Buchu, D. Tinctura Buchu, D.