This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
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. From the 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.
Impurities.-Spurious sacs, filled with dried blood, etc.
Composition.-Castor contains, in addition to the ordinary constituents of animal secretions, such as salts, a volatile oil, \ uric, carbolic and benzoic acids, salicin, and fixed oils.
Dose.-5 to 10 gr.
Tinctura Castorei.-1 in 20. Dose, 1/2 to 1 fl.dr.
The action of castor is stimulant like that of musk. The drug is very seldom used.