Oleum Ricini. Castor Oil.

Botanical name: 

This oil is obtained from the seeds of the plant RICINUS COMMUNIS, a member of the Natural Order Euphorbiaceae. This plant is a native of the East Indies and Africa, where it is a perennial and attains a height of thirty feet or more. As cultivated in more temperate latitudes, it is an annual, with a height of from six to ten feet, according to the soil, season, and amount of cultivation. Stem round, an inch and a half in diameter, smooth, hollow, purplish above. Leaves alternate, on long and strong petioles which are inserted on their under surface about one-third the diameter of the leaf from the base, palmately veined, with from seven to nine acute lobes, slightly purplish-green, ten to fifteen inches long by three-fourths as broad. Flowers monoecious, in terminal racemes several inches long, the whole having a pyramidal shape, the male flowers being below and the female flowers above. No corollas. Calyx of the male flowers of five oval and purplish segments; of the female flowers, three to five linear segments. Stamens numerous, fascicled at the base. Fruit a three-celled and somewhat three-sided capsule, smooth, with projecting spines, half an inch long, each cell containing a single large seed.

The seeds of this plant are compressed, oval, nearly the size of a small bean, grayish, mottled with reddish spots, shining. The oil is contained in the kernel, along with peculiar principles which seem to act as a ferment and speedily cause the oily portions to become rancid. The seeds themselves, when swallowed, act as a harsh purgative and emetic, and are considered dangerous. Their violent powers reside in the husk of the seed.

The oil may be obtained either by boiling or expression, or by the agency of alcohol. (See Olea Fixa.) The usual method is that by expression. "The seeds are conveyed into a shallow iron reservoir, where they are submitted to a gentle heat. The seeds are then introduced into a powerful screw press. A whitish oily liquid is thus obtained, which is transferred to clean iron boilers with a considerable quantity of water. The mixture is boiled for some time, the impurities being skimmed off, and a clear oil is at length left on the top of the water–the mucilage and starch having been dissolved, and the albumen coagulated by the heat. The clear oil is now carefully removed, and the process completed by boiling it with a minute proportion of water till vapor ceases to arise, and till a small portion of the liquid, taken out in a vial, continues perfectly transparent when it cools. This last operation clarifies the oil, and drives off the acrid volatile matter. If not carefully prepared, it is apt to deposit a sediment upon standing; and the apothecary may find it necessary to filter it through coarse paper." (U. S. Dispensatory.) Most of the oil in this country is from seeds raised in Southern Illinois. Sometimes it is merely expressed, and allowed to stand and clarify in barrels; but when thus treated, it deposits a white precipitate in cold weather, and dissolves it again on getting warmer. Fifteen bushels of the seeds may be made to yield forty gallons of the oil.

Good castor oil is viscid, transparent, almost without smell, and of a mild nauseous taste. The mass of that in market is ill-made, and has a quite unpleasant and decided smell, and is often tinged yellowish. Absolute alcohol dissolves it readily, diluted alcohol sparingly, and it is also soluble in ether. It very slowly dries by exposure, without changing color; and coarser qualities have been used in the arts. The alkalies saponify it, and exposure renders it rancid. When acrid, it may be rendered mild by boiling it with a little water.

Properties and Uses: Castor oil, when of a good quality, is a prompt and efficient cathartic, evacuating the bowels effectually and slightly promoting their mucous secretions, but not influencing the hepatic apparatus. A full dose usually acts in three hours, and secures the thorough ejection of alvine accumulations, such as hardened faces or any solids that may have been swallowed. A common article usually causes much griping, and some nausea, and is indeed very offensive to most stomachs; but a fresh and pure article is not often offensive, and causes very little griping, though some persons have an unconquerable aversion to its taste. It is used largely for children, and pregnant and puerperal women, for the earlier stages of dysentery and diarrhea to dislodge fecal accumulations, and in alvine irritation and costiveness due to the presence of offending substances.

Dose for an infant, one to three fluid drachms; for an adult, a fluid ounce. A young child seems, relatively, to require a larger dose than an adult. It is rarely given alone, but in some form to disguise its taste and smell. A good method is to mix it with some hot sweetened coffee, and add a little essence of peppermint, cinnamon, or other aromatic. Or it may be poured upon warm milk, and an aromatic added. A desirable method with this (or any other) ill-tasting article, is first to take into the mouth some aromatic, so as to get the nerves of taste fully occupied, and then take the medicine, by which method the taste of the oil will probably not be noticed. Or the oil may be made into an emulsion with the yolk of an egg, sugar, and a little water, or with gum and sugar in the usual way. This oil is sometimes used as an evacuating enema, especially in bilious and flatulent colic, for which purposes a fluid ounce may be given in a suitable quantity of tepid demulcent solution.

The leaves of ricinus, wilted in warm water and laid on the breasts, are said to promote the secretion of milk quite actively. The fresh leaves are better than the dried, though both are used.

On the other hand, some physicians assert that they will decidedly diminish this secretion. Admixture with lard is said to diminish its tendency to become rancid. It may be used in cerates in place of olive oil, when mild stimulation is desired.

The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com