_Civet_ (_zibethum_) is derived from two animals of the genus _Viverra_. The actual civet cat (_Viverra civetta, L._) lives in the hottest parts of Africa from the Guinea Coast and the Senegal to Abyssinia, where it is carefully bred for its civet. The product is also obtained from _Viverra zibetha, L._, indigenous to the Moluccas and Philippines. The civet is secreted in a cavity between the anus and the external genitals, and is scraped out with a spoon. It is semi-liquid, unctuous, yellowish, becoming brown and thicker by exposure to the air, of a bitter, disagreeable, fatty taste, and of a peculiar, urinose, disagreeable odor, resembling that of musk which becomes agreeable only when much diluted and mixed with other perfumes. When ignited it burns with a bright flame, leaving behind 3 to 4 per cent. of ash. It is insoluble in water; in spirit of wine it partially dissolves with difficulty, and with greater ease in warm ether and in chloroform. It should form a homogeneous, non-crumbling mass. According to M. Boutron Chalard, it contains free ammonia, stearin, olein, mucus, resin, a yellow coloring substance, salts, and a volatile oil, the latter giving the odor to it. In perfumery, civet is chiefly used as an addition to other perfumes in order to strengthen them and make them more constant. It is also employed for perfuming fine leather articles. _Castor_ or _castoreum_ is a peculiar concrete substance obtained from _Castor fiber_ or the beaver. In both sexes between the anus and external genitals are two pear-shaped sac-like follicles (Fig. 24) united at their thin ends. The follicles contain, when fresh, a semi-liquid substance which becomes more solid by drying. The castor occurring in commerce is generally dried by smoke. [Illustration: FIG. 24.] In commerce two principal varieties are distinguished: Siberian or Russian and Canadian, English or American castor, the first being the most valuable. The length of a Siberian sac varies between 2.36 and 4.72 inches, the width between 0.98 and 2.55 inches, and the thickness between 0.78 and 1.57 inches; it weighs from 1.76 to 8.81 ozs. One of the sacs is generally somewhat smaller than the other. The exterior skin of the sac is almost smooth and, in a dry state, dark brown; the interior is dirty yellow, intermixed with a dense cellular tissue, which envelops the castor-substance and is grown together with it. In a dried state, the latter is dark brown, without lustre, almost friable, of a very strong, peculiar odor, and a pungent, somewhat bitter, aromatic taste. The sacs of Canadian castor are smaller than the Siberian, they being at the utmost 3.15 inches long, 0.98 inch thick, and darker and uneven. The interior mass is resinous, hard, with a lustrous fracture, red-brown, and can be readily pulverized. The odor is weaker, somewhat musty and ammoniacal, and the taste more bitter and less pungent than that of the Siberian castor.