Adipocere

Adipocere ( /ˈædɨpɵsɪər/), also known as corpse, grave or mortuary wax, is a wax-like organic substance formed by the anaerobic bacterial hydrolysis of fat in tissue, such as body fat in corpses. In its formation, putrefaction is replaced by a permanent firm cast of fatty tissues, internal organs and the face.

History

Adipocere was first described by Sir Thomas Browne in his discourse Hydriotaphia, Urn Burial (1658):^[1]

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 castile-soap: wherof part remaineth with us.

The chemical process of adipocere formation, saponification, came to be understood in the 17th century when microscopes became widely available.^[1]

Augustus Granville is believed to have somewhat unwittingly made candles from the adipocere of a mummy and used them to light the public lecture he gave to report on the mummy's dissection.^[2]

Appearance

Adipocere is a crumbly, waxy, water-insoluble material consisting mostly of saturated fatty acids. Depending on whether it was formed from white or brown body fat, adipocere is grayish white or tan in color.^[1]

In corpses, the firm cast of adipocere allows some estimation of body shape and facial features, and injuries are often well-preserved.^[1]

Formation

The transformation of fats into adipocere occurs best in the absence of oxygen in a cold and humid environment, such as in wet ground or mud at the bottom of a lake or a sealed casket, and it can occur with both embalmed and untreated bodies. Adipocere formation begins within a month of death, and in the absence of air it can persist for centuries.^[3] An exposed, infested body or a body in a warm environment is unlikely to form deposits of adipocere.

Corpses of women, infants and overweight persons are particularly prone to adipocere transformation because they contain more body fat.^[1] In forensic science, the utility of adipocere formation to estimate the postmortem interval is limited because the speed of the process is temperature-dependent. It is accelerated by warmth, but temperature extremes impede it.^[1]

Footnotes

1. ^ ^{a b c d e f} Murad, Turhon A. (2008). "Adipocere". In Ayn Embar-seddon, Allan D. Pass (eds.). Forensic Science. Salem Press. pp. 11. ISBN 978-1-58765-423-7. 
2. ^ Pain, Stephanie (1 January 2009). "What killed Dr Granville's mummy?". New Scientist (2687). http://www.newscientist.com/article/mg20026877.000-what-killed-dr-granvilles-mummy.html. 
3. ^ "Decomposition: What is grave wax?". http://web.archive.org/web/20090215164423/http://deathonline.net/decomposition/body_changes/grave_wax.htm. Retrieved 2011-10-06.