Adipocere

Adipocere or grave wax or mortuary wax is the insoluble fatty acids left as residue from pre-existing fats from decomposing material such as a human cadaver. It is formed by the slow hydrolysis of fats in wet ground and can occur in both embalmed and untreated bodies. It is generally believed to have first been discovered by the Frenchman Fourcroy in the 18th century; however, Sir Thomas Browne describes this substance in his discourse, Hydriotaphia, Urn Burial of 1658:


 * "In a Hydropicall body ten years buried in a Church-yard, we met with a fat concretion, where the nitre of the Earth, and the salt and lixivious liquor of the body, had coagulated large lumps of fat, into the consistence of the hardest castle-soap: wherof part remaineth with us."

In essence, in this process the usual dissolution of putrefaction is replaced by a permanent firm cast of fatty tissues. This allows some estimation of body shape and facial features, and injuries are often well-preserved.

Adipocere inhibits the growth of bacteria, and can go some way to protecting a corpse against decomposition. It begins to form within about a month of death, and can persist on the remains for centuries. Since it forms through hydrolysis, it does so more readily in humid environments or even underwater. An exposed body is unlikely to form deposits of adipocere. The process of adipocere formation is also known as saponification.

The Mütter Museum possesses the Soap Lady, the body of an extremely obese woman, which was almost entirely saponified.

Adipocere is also the name of a French independent record label, specializing in metal (music).