ADIPOCERE, from adeps and cera: a term given to a peculiar fatty matter, somewhat re sembling spermaceti in appearance, and sup posed to partake of the properties of fat and wax. In the year 1789, Fourcroy communi cated to the Royal Academy of Sciences at Paris a curious account of the changes sus tained by the human bodies interred in the cemetery of the Innocents in that city; some of these had been piled, for a succession of years, closely upon each other, in large cavities containing from one thousand to fifteen hundred.
individuals. One of these graves, opened in Fourcroy's presence, had been full, and closed for fifteen years. When the coffins were opened, the bodies appeared shrunk and flattened, and the soft solids were converted into a brittle cheesy matter, which softened and felt greasy when rubbed between the fingers. The bones were brittle ; and the texture of the abdominal and thoracic viscera no longer discernible, but lumps of fatty matter occupied their places.
It is not uncommon to find masses of this adipocere in the refuse of dissecting-rooms, especially when heaps of such offal are thrown into pits and wells, and suffered gradually to decay. The carcases of cats and dogs and other drowned animals also often exhibit more or less of a similar change ; and Dr. Gibbes (Phil. Trans. 1794) found that lean beef, se cured in a running stream, underwent a change into fat in the course of three weeks. Fat, and the adipose parts of animals, also undergo a change in appearance and composition under similar circumstances : tallow becomes brittle and pulverulent, and may be rubbed between the fingers into a white soapy powder.*
Gay Lussac, Chevreul, and some other emi nent chemists, conceive that muscular fibre, skin, &c. is not convertible into adipocere,but that this compound results entirely from the fat originally present in the substance, and that the fibrin is completely destroyed by putrefaction. There are cases, however, in which the conversion of muscle and of fibrin into fat can scarcely be doubted, (Annals of Philosophy, xii. 41,) though the propriety of applying the term adipo cere to such fatty matter may be questionable. The action of very dilute nitric acid upon some of the modifications of albumen is also attended by their conversion into an adipose substance.
The chemical properties usually ascribed to adipocere are the following: it fuses at a tem perature below 100°; it dissolves in boiling alcohol, and the greater portion is deposited as the solution cools; the action of ether resembles that of alcohol ; it is saponified by the fixed alkalies, but not by ammonia. It would ap pear, however, from Chevreul's experiments, that adipocere is not a mere modification of fat, or a simple product, but that it is a soap composed of margaric acid and ammonia. These combinations of adipose substances and their further chemical history will be given under the article FAT.