Musk is a peculiar concrete secretion obtained from _Moschus mochiferus, L._, an animal bearing a close resemblance to the deer in shape and size, and indigenous to the high plateaus of Asia. The musk is contained in an oval, hairy, projecting sac, found only in the male, situated between the umbilicus and the prepuce. It is from 2 to 3 inches long and from 1 to 2 broad. In commerce, several varieties of musk are distinguished, the principal ones, however, being Tonkin and Kabardin musk. _Tonkin_, _Thibet_, or _Oriental musk_, _Yunnan musk_ (_Moschus tonquinensis_, or _orientalis_, or _transgangetanus_) is the best variety. It comes from China, Tonkin, and Thibet. It consists of sacs of a puffed-up appearance, more roundish than longish, varying in size, being at the utmost 1.77 inches long, up to 1.57 inches broad and 0.59 to 1.18 inches thick, and weighing from 8.46 drachms to 1 oz. 9.39 drachms each. The hairy side of the sac is concave and the other flat. Fig. 21 shows an unshorn Tonkin musk sac of medium size from the concave or hairy side and Fig. 22 the same from the side. The envelop of the sac consists of a double skin, the outer skin being gray-brown. One side of the sac is covered with stiff, yellowish hair with red-brown points, generally cut short. The original packages, containing usually 24 sacs each, consist of longish, four-cornered boxes lined with lead-foil and covered outside with some silken stuff. Each sac is separately wrapped in tissue paper. The musk-substance appears as a dark red to black-brown mass intermingled with hair, and forming roundish grains. The odor is penetrating and the taste bitter. [Illustration: FIG. 21.] [Illustration: FIG. 22.] [Illustration: FIG. 23.] _Kabardin_, _Siberian_, or _Russian musk_ (_Moschus sibirius_, or _cabardinicus_) is a cheaper variety of an inferior quality, which is brought from Mongolia and Siberia. The sacs (Fig. 23) are longish, generally pear-shaped, flatter in proportion to their longitudinal and latitudinal dimensions, and not of a puffed-up appearance, the surface being frequently even shrivelled or wrinkled. The outer skin is denser and harder, and on the convex side covered with longer hair (up to 0.9 inch long), of nearly a silver or brownish color. Towards the edge of the sac the hairs are, however, frequently so trimmed and shorn as to give the sac a resemblance to the Tonkin article. The musk-substance inclosed in the sac amounts to from 8.46 drachms to 1 oz. It is somewhat paler, more brown or yellow-brown, soft, almost unctuous, when fresh, but after storing, solid or granular-pulverulent, like ground, burnt coffee. The odor is weak, offensive, more urinose, resembling that of castor, or horse sweat.