A solid, opake, fatty substance, found on the sea-coast, or sometimes floating on the sea, chiefly in the tropical regions. It is of various colours, but generally of a deep ash-coloured yellow. It is most frequently obtained in small fragments, but large masses, weighing from 100 to 180 lbs. have been found. It has frequently been discovered in the intestines of the spermaceti whale, and is supposed to be the cause, or the result of disease in the animal. Healthy fish, which void their excrements when they are hooked, seldom contain amber; but diseased fish, unable to perform this function when caught, generally yield it; and it is almost always found in the faeces of the whale when dead and floating on tho waters. There can be little doubt that this substance informed in the intestines of the animal, not swallowed by it as some have supposed; for no large piece has yet been found in the whale, which does not contain the beaks of the Sepia octopodia, the common food of the spermaceti whale. When first obtained, ambergris has the foetid smell peculiar to the faeces of the animal; but after a short exposure to the air and washing, its odour is fragrant, and is increased by heating.

It is not a little extraordinary that Mr. Homberg obtained, by long digestion of human excrement, a substance which possessed, in a very intense degree, the perfect smell of ambergris. The spec. grav. of ambergris varies from 0.780 to 0.926. It melts at 144° Fahr, and at 212° Fahr, is volatilized in the form of a white vapour. If thrown on hot coals, it burns and is entirely dissipated. It is not soluble either in water or the acids. Ether, ammonia, and oil, dissolve it, but alcohol acts only on a portion, and is therefore useful in analyzing it Caustic alkalies combine with it and form a soap. According to La Grange, it is composed of adipocere resin, benzoic acid, and coal. By later analysis it lias been found that some specimens do not contain benzoic acid. The alcoholic solution is used in cosmetics, etc, to communicate its peculiar odour.