Contractions. - Cast. Cas.

Castor Fiber. Class, Mammalia; Order, Rodentia; Fam., Muridae; Sub-fam., Castobina.

The Beaver.

The substance used in medicine is the secretion of the Castor-sacs of the beaver. Castor is imported from Russia and America; that usually found in this country comes from the Hudson's Bay territory.

Characters. - Follicles in pairs, about 3 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.

Preparation. - Tincture, using rectified spirit.

Reference to Hom. Proving. - Ann. d. Horn. Klin., iii.

Proper forms for dispensing. - φ and upwards, Tincture, Pilules, or Globules.