Mummies

For legal medicine purposes, the state of conservation of a corpse is crucial to determining the cause and time of death . Conservative-transformative phenomena, also called spontaneous mummification, can occur when a body is exposed to favorable conditions, such as dehydration combined with heat, or dehydration combined with freezing temperatures. Mummification may occur naturally or may be achieved through artificial methods. Ancient Egyptians, Incas, and the natives of the Canary Islands used different methods to embalm and conserve the bodies of their dead. In modern societies, embalming is also practiced when requested by the family of the deceased or to preserve corpses for academic teaching and research.

Forensic scientists, forensic anthropologists, and forensic archeologists work together to unwrap the mysteries surrounding both preserved and naturally occurring mummies. DNA fingerprinting and skull reconstruction, techniques originally developed to solve crimes, are useful in investigating mummified human remains. Investigators may also use CT scans to help determine the cause of death , radiocarbon dating to help determine the time of death, and knowledge of forensic entomology (insect evidence ) to determine what happened to the mummy at different stages after death.

The natural mummification process usually happens in extremely dry environments that allow the fast dehydration of tissues, simultaneously slowing down or inhibiting the decomposition by bacteria and other microorganisms. Bodies buried in the sands of the Takla Makan Desert in Asia and the Atacama Desert in the north of Chile have been found mummified even thousands of years after death. Mummification also happens to the bodies of people who die on the desert surface, where direct exposure to sunlight and the highly dry atmosphere favor rapid dehydration. Stone crypts sometimes house conditions favorable for natural mummification, such as occurred in the catacombs of the Franciscan Brotherhood in Tolosa, Spain, and in the crypt of Saint Boumet-le-Chatêau, where more than 30 mummies exist in a perfect state of conservation. These two locations share in common a dry climate, crypts that have a natural constant temperature of about 59°F (15°C), and enough air movement to prevent vapor from the bodies to build up in the crypts.

Natural mummification is also favored by some other factors, such as age (it is more common in newborns), gender (occurs more often in female corpses), and cause of death (large hemorrhages, ante-mortem prolonged administration of antibiotics , and poisoning by arsenic and potassium cyanide). The external aspect of both natural and man-made mummies includes drastic body-weight reduction, dried leather-like shrunken and darkened skin, reduced volume of the head, and well-conserved teeth and nails. Facial features are in a measure preserved, but tendons and muscles are very fragile and disintegrate at touch. Another environment that favors mummification is freezing temperatures associated with dry climates such as those found in upper altitudes in the Himalayas, Alps, as well as in the Artic and Antarctic caps. The famous Otzi mummy, also known as "Iceman," was found in the Tyrolean Alps in 1991, after approximately 5,000 years, in highly conserved conditions and still bearing the wounds of the weapon that killed him. From the position of his fallen body and his wounds, it was possible to make a crime scene reconstruction , 5,300 years after the murder .

Peat bogs, the soft moist soil formed by the partial decay of vegetation, are very acidic due to high kevels of tannin, one of the compounds used in leather conservation. Marshes and other peat bogs in Scandinavia, Ireland, and Scotland have yielded from time to time well-preserved mummies from the Bronze and Iron Ages. Perhaps the first peat bog mummy to draw the attention of anthropologists was the one known as Tollund Man, found in a peat bog on Denmark in 1950. An autopsy revealed even his last meal and estimated the time of death as having occurred 12 hours after that meal, through the analysis of the well-conserved partially digested grains in his stomach. The mummy was dated as having died around 350 b.c., at the approximate age of 40. Among the seeds present in his stomach were found barley, knotweed, bristle grass, chamomile, and some other wild seeds, suggesting that such a meal was a soup. Since those seeds were only cropped in the spring in those latitudes, researchers could conclude that he died during a spring season. As he had a rope with a knot and noose around the neck and clear marks of the knot in the skin of his neck, they concluded that he had been hung (cause of death), although his bones were very deteriorated to allow the verification of a neck fracture. These and other lines of analysis are what a forensic anthropologist considers when investigating a "cold case."

Calcification is a conservative-transformative phenomenon by which a corpse is "petrified" due to the rapid absorption of calcium salts by the skeleton in the presence of bacterial decomposition of internal organs. Fetuses that die in the womb are more likely to undergo calcification than other bodies. However, most fetuses undergo maceration (softening of the tissues) and not calcification when death occurs in the womb, due to the presence of the amniotic fluid in the mother's uterus. Colorification is a very rare mummification phenomenon, described in 1985 by Della Volta, occurring in cadavers kept in perfectly sealed zinc urns. The mummies' skin has the appearance of rawhide, with a flattened and depressed abdomen, muscles, and subcutaneous tissues well preserved, and internal organs softened and generally conserved. A small quantity of a viscous liquid of a brown-yellowish tonality is usually found at the bottom of such urns. The exact process underlying this type of mummification is not yet understood.

see also Anthropology; Autopsy; Body marks; Coroner; Crime scene reconstruction; Death, cause of; Entomology; Hanging (signs of); Medical examiner.