Spec. Plant Willd. iv. 564. Cl. 21. Ord. 8. Monoecia Monadelphia. Nat. ord. Euphorbiaceae. G. 1720. Male. Calyx five-parted. Corolla none. Stamens numerous. Female. Calyx three-parted. Corolla none. Styles three, bifid. Capsule three-celled. Seed one. * With palmated leaves. Sp. 1. R. communis.1 Common Ricinus, or Palma Christi. Med.

Bot. 3d edit. 625. t.221. Rheede, Hort. Malab. ii. 57. t. 32. Officinal. Ricini oleum, Lond. Ricini communis semina; et oleum fixum, Edin. Ricinus; oleum e seminibus, Dub.

The seeds, and the fixed oil of the seeds of the Ricinus. Castor

Oil.

Syn. La noix et l'huile du Ricin (F.), Rizinuskorner Rizinusohl (G.), I semi e l'olio di Ricino (I.), Palmoel, Ricinsoel (S.), Erundatylum (San.), Duhnul Kirwa. (Arab.), Sittamoonaka unnay (Tarn.), Endooroo tail (Cyng.), Rowgen Bedangur (Pers.), Miniak jarak (Malay), Linga-jarak (Jav.).

This species of ricinus is an annual plant, a native of Greece2, Asia, Hindostan, the East and West Indies, South

2 At Pamisus, in the Morea, where it grows in great abundance, it is called agra staphylia, or wild vine, from the resemblance of its leaves to those of the vine.- Gell's Journ. in the Morea, p. 193. In the Bosphorus it is called Kroton, from the resemblance of the seeds to the tick insect which fastens on dogs' ears.- Hort. Trans, vol. vi.

America, and Africa.1 It is also abundant on the rock of Gibraltar. It is of very quick growth, and sometimes attains to the height of sixteen feet.2 The stem is round, thick, jointed, furrowed, glaucous in the lower part, but of a purplish red colour towards the top: the leaves are petiolate and sub-peltate, large, deeply divided into seven pointed serrated lobes, and of a bluish green colour: the calyx of the male flower is composed of five oval, pointed, purplish segments, enclosing many long stamens united at the base; the female is at the upper part of the spike, and is composed of a three-cleft reddish calyx: the styles are three, slender and forked at the apex: the capsule is a trilocular nut, covered with rough spines, and bursting elastically to expel the seeds; which are generally three, of an oblong flat figure, and of a black colour dotted with white.

The oil, which is more frequently used than the seeds, is obtained from the seeds both by coction and expression. The former method was generally used till lately; and was performed by tying up the seeds, previously decorticated and bruised, in a bag, which was suspended in boiling water, till all the oil was extracted, and rose to the surface of the water, when it was skimmed off. This mode of preparation is still preferred by many of the West Indian practitioners; but the oil is apt to get soon rancid when it is thus prepared. It is now obtained, both at home and abroad, by subjecting the seeds to the press, in the same manner as almonds to procure almond oil. The oil obtained by expression is equal to one fourth of the weight of the seeds employed. The acrid principle is contained in the cotyledons, and in the embryon, but not in the testa. It is of a volatile nature. Castor oil is often adulterated with olive oil, linseed oil, and poppy oil, which, however, may be readily detected by adding an equal quantity of alcohol of sp. gr. .820 to any given quantity of the suspected oil: if it be pure, a uniform solution will take place, which will not happen should it be adulterated; and the same will be the case, if a weaker spirit be employed, with the addition of camphor.

Qualities. - Good expressed castor oil is nearly inodorous and insipid; but even the best leaves a slight sensation of acrimony in the throat after it is swallowed. It is thick, viscid, transparent, and colourless, or of a very pale straw-colour; that which is obtained by coction has a brownish hue; and both kinds, when they become rancid, thicken, deepen in colour to reddish brown, and acquire a hot, very nauseous taste. MM. Busy and Lecanu have obtained three distinct acids from it: the ricinic, fusible at 72° Fahr.; the elaiodic, fluid below 32° Fahr.; and the margaritic, not fusible below 264° Fahr., and crystallizable. It has all the chymical characters of the other expressed oils, except that it is heavier, and saponifies more readily with solutions of potassa or of soda; and racinates, elaiodates, margaritates, and glycerin are formed. It is very soluble in alcohol, and also in sulphuric ether. Mr. Brande says, that it sometimes undergoes such a change in the bowels that it passes off "in round and indurated nodules."1 But such a circumstance has never come within my knowledge.

1 It was first cultivated in Britain in 1562. It thrives in the South of France.

2 It has been asserted that this plant is in some places perennial, becoming a large tree. Willdenow, however, says, "Planta semper, annua, nunquam fruti-cosa vel arborea, nee in calidissimis terrae plagis lignescit."-Spec. Plant. iv. 564.

Medical properties and uses.-The seeds are drastic cathartics, but are scarcely ever ordered. The oil is mildly purgative, operating very quickly2, and with so little irritation, as to render it peculiarly fitted for cases in which the stimulating purgatives would prove hurtful; as in ileus, colica pic-tonum (in which it may be advantageously joined with henbane), calculous affections, piles, and after surgical operations in which the abdominal viscera are concerned. In dysentery, in which this oil is particularly indicated, the stomach will seldom retain it; but, when this is the case, it may be efficaciously exhibited per anum. It is also an excellent purgative for infants, even of the tenderest age, and for women in childbed. As ah external application I have found it useful in Lepra vulgaris, when rubbed up with the ointment of nitrated mercury, in the proportion of one part of the oil to two parts of the ointment.

The dose is from f3 iv. to f jss., either floated on a little water and covered with a small quantity of any ardent spirit, or diffused in a cup of coffee; or in cinnamon or mint water, or camphor mixture, by means of mucilage of acacia gum, or the yolk of egg. The addition of some aromatic tincture is generally necessary to make this oil remain on the stomach.