A fixed oil expressed from the seed of Croton Tiglium Linne.

Habitat.—Asia, India, Indian Archipelago and Philippine Islands.

Properties.—A pale yellow or brownish-yellow, somewhat viscid, and slightly fluorescent liquid, having a slight fatty odor, and a mild, oily afterwards acrid and burning taste (great caution is necessary in tasting). Specific gravity 0.935 to 0.950 at 25° C. (77° F.).

Constituents.—Crotonoleic acid is the purgative principal. A small amount is free in the oil but it is mostly formed within the bowels. It resembles acid of castor oil in its chemistry; crotonol is a non-purgative body causing irritation of the skin; tiglinic acid and other volatile acids existing as glycerides and accounting for the odor of croton oil; it also contains free and combined fatty acids.

Dose.—Horses, 15 to 30 m.; cattle, ¹/₂ to 1 dr.; sheep and pigs, 5 to 10 m.; dogs, ¹/₂ to 2 m.

Actions.—It is a powerful irritant and pustulant, is a drastic hydragogue cathartic; full doses cause gastro-enteritis and much prostration; undiluted it seriously and deeply inflames the skin, causing severe blemishes and by absorption it may cause fever and superpurgation. The purgative action is probably due in part to direct irritation of the intestinal mucous membrane; in part to absorption and elimination of the purgative principle by the bowels.

Uses.—Cattle are the only animals for which it can be used with any degree of safety; it can be used for dogs and pigs if used with great caution. For horses and sheep it is too irritating and depressing; it is used in cattle as an active hydragogue purgative when they suffer from lodgment of fecal matter in the third stomach and other forms of constipation, and from torpidity of the bowels. Should not be used in debilitated, delicate or young animals. If an over-dose has been given combat with demulcents, opium and stimulants. It should not be used as a counter-irritant or applied to the skin in any form or for any purpose. Croton oil (in a pint of linseed oil) is valuable in assisting the action of salts in obstinate constipation of cattle. It may be given to horses when a powerful derivative and purgative action is indicated, as in acute inflammation of the brain and spinal cord with calomel and aloes in a capsule.