Since, on account of the high price of musk, the musk animal is much hunted, there is a possibility of it becoming in time extinct. For this reason a substitute has been long searched for, and is believed to have been found, especially, in the American musk-rat (_Fiber zibethicus_), which is chiefly hunted for its skin. In this animal the musk is found in two small sacs located between the anus and generative organs, and is emitted when the animal becomes excited. According to R. S. Cristiani, this musk is invaluable for the toilet soap industry of America, it being nearly as good and strong as genuine musk. Cristiani has formerly used much of it for scenting soaps, powders, etc., but does not recommend it for essences. When used for soaps, some time is required for the odor to become refined, and if a piece of soap scented with it is stored for a few months, it would, according to Cristiani's assertion, be difficult even for an expert perfumer to distinguish the odor from that of genuine Tonkin musk. As possible substitutes for the musk deer may further be mentioned a species of rat indigenous to the West Indies, and an antelope of North Africa. It is also said that musk derived from the Mississippi alligator has been brought into commerce. The sacs are said to be small, the odor somewhat different from that of genuine musk, resembling that of civet, but suitable for perfuming purposes. A process for the preparation of _artificial musk_ has been patented by Dr. Baur, of Gispersleben. According to the specification, toluol is mixed with the halogen compounds of butane and boiled with the addition of aluminium chloride or aluminium bromide. The product of the reaction is mixed with water and distilled with steam. The fraction passing over between 338° and 392° F. is caught and treated with fuming nitric acid and fuming sulphuric acid. The product obtained is washed with water and alcohol, and crystallized. The artificial musk forms an amorphous white powder, which in time becomes yellow. It is readily soluble in 90 per cent. alcohol, but from solutions in weaker alcohol it again crystallizes out at a cool temperature. The odor becomes very pronounced after the addition of 5 drops of ammonia to 1 pound of a one per cent. solution. This artificial product having been in existence but for a short time, it is not possible to come to a final conclusion as to its availability. However, its odor differs essentially from that of the genuine article, and it can scarcely be employed for fine extracts; if low enough in price it might, however, be suitable for soaps and cheaper perfumes.