Not officinal. - The dried preputial follicles and their secretion, obtained from the beaver, Castor Fiber, and separated from the somewhat shorter and smaller oil-sacs which are frequently attached to them. Hudson's Bay Territory.

Characters. - Follicles in pairs, about three inches long, fig-shaped, firm, and heavy, brown or greyish-black; containing a dry resinous reddish-brown or brown highly odorous secretion, in great part soluble in rectified spirit, and in ether.

Composition. - Several fats, salicin, a bitter resin, and bitter volatile oil.

Dose. - 5-10 gr.

Preparation.

Dose.

Tinctura Castorei........................

22 gr. to 1 fl. oz..............

1/2-1 fl. dr.

Action and Uses. - Castor is used chiefly as an antispasmodic and stimulant. It may be given in hysteria and epilepsy. Its action is very like that of musk.