Ruta. Rue. The leaf of Ruta graveolens, or Common Rue; Lin. Syst., Decandria monogynia: a plant growing throughout Europe. (Not officinal.)

Rutae Oleum. English. Oil of Rue. Distilled from the fresh leaves and the unripe fruit of Ruta graveolens or common rue.

Description. The leaves are supra-decompound, the leaflets oblong and ovate, glaucous green, fleshy, and dotted. The oil is of a greenish-yellow colour, sp. gr. about 0.837.

Prop. & Comp. The leaves owe their properties chiefly to the volatile oil, which has a strong, disagreeable odour, and acid taste; becomes brown by keeping. The composition of this oil appears to be complex; it is stated to consist chiefly of euodic aldehyde (C22 H22 O2), mixed with a small amount of lauric aldehyde (C24 H24 O2), and a hydrocarbon isomeric with oil of turpentine and bar-neol. Rue leaves contain, besides this oil, a bitter extractive matter, soluble in water.

Therapeutics. Rue, or its oil, acts as a powerful topical stimulant, and has been used in flatulent colic; it also appears to be an antispasdomic and emmenagogue, and seems useful in hysterical affections, and in epilepsy; by some it has been thought anthelmintic. Externally, rue may be used as a rubefacient. Sometimes employed in the form of enema.

Dose. Of the powdered leaves, 20 gr. to 40 gr.; of oleum rutae, 2 min. to 6 min.

Bucco. Buchu. [Buchu. Buchu. The leaves of Barosma crenata and other species of Barosma. U. S.] The leaves of Barosma betulina, Barosma crenulata, and Barosma serratifolia; imported from the Cape of Good Hope.

Description. The leaves of all three species are smooth, and marked with pellucid dots (oil glands) at the indentations and apex, and possess a powerful odour and camphoraceous taste.

The leaf of Barosma betulina is about three quarters of an inch long, coriaceous, obovate, with a recurved truncated apex, and sharp cartilaginous spreading teeth.

The leaf of Barosma crenulata, about an inch long; oval-lanceo-late, obtuse, minutely crenated, five-nerved.

The leaf of Barosma serratifolia, from an inch to an inch and a half long, linear-lanceolate, tapering at each end, sharply and finely serrated, three-nerved.

Prop, & Comp. Buchu contains a volatile oil, which gives the odour to the leaves, and a bitter extractive matter, soluble in water.

Off. Prep. Infusum Bucco. Infusion of Buchu. (Buchu leaves, half an ounce; boiling distilled water, ten fluid ounces.) [Buchu, a troy ounce; boiling water, a pint. U. S.]

Tinctura Bucco. Tincture of Buchu. [Not officinal in U. S. P.] (Buchu, bruised, two ounces and a half; proof spirit, one pint. Prepared by maceration and percolation.)

[Extractum Buchu Fluidum. Fluid Extract of Buchu. U. S. Sixteen fluid ounces of fluid extract are prepared by percolation with alcohol and evaporation from sixteen troy ounces of powdered Buchu leaves.]

Therapeutics. Buchu seems to be a slight tonic and stomachic, but is used chiefly on account of its action on the urinary organs, in chronic catarrh of the bladder, and irritable condition of these parts; it acts, also, as a diuretic, and occasionally as a diaphoretic.

Pose. Of the powder, 20 gr. to 40 gr.; of infusum buchu, 1 fl. oz. to 2 fl. oz.; of the tincture, 1 fl. drm. to 2 fl. drm. [of the fluid extract, 1 fl. drm.].

Cusparia. Cusparia Bark. [Angustura. IT. S.] The bark of Galipea Cusparia, Angustura bark tree; from tropical South America.

Description. In curved pieces, or quills, several inches in length, about an inch or rather more in breadth, and one-eighth of an inch thick; the edges are feathered. Externally it is covered with a yellowish grey, uneven epidermis; internally, light brown, and separable into thin layers. It breaks with a resinous fracture; has a rather peculiar odour, and a very bitter, but aromatic taste; the cut surface, examined with a lens, usually exhibits numerous white points or minute lines.

Prop. & Comp. Cusparia bark contains a trace of volatile oil, some resin, and a principle, cusparine, in tetrahedral crystals, soluble in alcohol, acids, and alkalies; composition unknown. The infusion of cusparia is precipitated by tannin, so also is cusparine.

Of. Prep. Infusum Cusparae. Infusion of Cusparia. (Cusparia bark, in coarse powder, half an ounce; distilled water at 120°, ten fluid ounces.)

Therapeutics. An aromatic stomachic, and probably has anti-periodic properties. Used in atonic dyspepsia, diarrhoea, and dysentery, also in convalescence from acute diseases. In South America it has been much employed in the treatment of low malignant fevers, occurring in marshy districts; it is not much prescribed in England, nor have its powers been fully investigated.

Pose. Of the powdered bark, 10 gr. to 40 gr.; of infusum cus-pariae, 1 fl. oz. to 2 fl. oz.

Adulteration. The bark of strychnos nux vomica has been substituted for true cusparia or angustura bark, and hence named false angustura bark; as this substitution has been the cause of fatal accidents, the knowledge of the distinction between the two becomes important. The false bark is usually in shorter pieces, more irregularly twisted, with little or no odour, and much more bitter than the true bark; it breaks with a shorter and more resinous fracture, and is not separable into layers; the epidermis is whitish but spotted red; nitric acid turns the inner surface blood-red, the epidermis greenish or black; true cusparia is, however, not reddened by nitric acid, when applied to the inner surface. False cusparia bark yields brucia and strychnia; the true bark contains neither of these alkaloids.