Mummy

A mummy is a corpse whose skin and organs have been preserved by either intentional or incidental exposure to chemicals, extreme coldness (ice mummies), very low humidity, or lack of air when bodies are submerged in bogs. Presently, the oldest discovered (naturally) mummified human corpse was a decapitated head dated as 6,000 years old and was found in 1936. The most famous Egyptian mummies are those of Seti I and Rameses II (13th century BC), though the earliest known Egyptian mummy, nicknamed 'Ginger' for its hair color, dates back to approximately 3300 BC.
Mummies of humans and other animals have been found throughout the world, both as a result of natural preservation through unusual conditions, and as cultural artifacts to preserve the dead. There are more than 1000 mummies in dry Xinjiang China. Over one million animal mummies have been found in Egypt, many of which are cats. There are so called mummies of mythical beings.
Mummia or Mumia, is a kind of powder taken from mummies. It traditionally originates as asphaltum, bitumen, mineral pitch or carabe which has in the past been used as one of the ingredients in the preservation process of mummies.
Asphaltum is a resin but it is not commonly used as incense and the smell is rather unattractive; but it was an ingredient in Plutarch's version of kyphi and is still sometimes used as incense by occultists and magical practitoners. Asphaltum is often used nowadays as a pigment, and also is used in some types of folk medicine. In ancient times it was used to fill out the body cavities of some Egyptian mummies. Reportedly, the black color of the mummies was attributed to the use of this pitch, although it is known nowadays that the blackened color is only a result of the drying process which the bodies would undergo. Nevertheless, this erroneous notion caused the belief that all mummies contained large amounts of asphaltum in their making.
The term "mummy", referring to preserved corpses, is derived from the ingredient mummia. Ancient Egyptian mummy-making often utilized asphaltum (Persian: mumiya) as an ingredient for filling the empty body cavities once the organs were removed. In the Middle Ages, the resin that had been used on ancient Egyptian mummies was believed to have superior medicinal and chemical value to regular asphaltum, and the resulting demand for the ingredient caused the term to be applied to the dead bodies required to harvest it as much as to the ingredient itself. In The Chemistry of Paints and Painting by Arthur H. Church, a description is given of mummia's preparation for paint-making:

'Mummy,' as a pigment, is inferior to prepared, but superior to raw, asphalt, inasmuch as it has been submitted to a considerable degree of heat, and has thereby lost some of its volatile hydrocarbons. Moreover, it is usual to grind up the bones and other parts of the mummy together, so that the resulting powder has more solidity and is less fusible than the asphalt alone would be. A London colourman informs me that one Egyptian mummy furnishes sufficient material to satisfy the demands of his customers for twenty years.

Mummia was offered for sale medicinally as late as 1908 in the catalogue of E. Merck. 
While Egyptian mummies were traditionally the source for mummia, as demand increased throughout the Renaissance, other types of corpses came to be used including non-Egyptian mummies and bodies of the recently deceased that were specially prepared. This was sometimes called mumia falsa

The Egyptian mummification process

The earliest known Egyptian mummy , nicknamed 'Ginger' for its hair colour, dates back to approximately 3300 BC. Currently on display in the British Museum, Ginger was discovered buried in hot desert sand. Desert conditions can naturally preserve bodies so it is uncertain whether the mummification was intentional or not. However, since Ginger was buried with some pottery vessels it is likely that the mummification was a result of preservation techniques of those burying him. Stones might have been piled on top to prevent the corpse from being eaten by jackals and other scavengers and the pottery might have held food and drink which was later believed to sustain the deceased during the journey to the afterlife.
From the Middle Kingdom onwards, embalmers used salts to remove moisture from the body. The salt-like substance natron dried out and preserved more flesh than bone. Once dried, mummies were ritualistically anointed with oils and perfumes. The emptied body was then covered in natron, to speed up the process of dehydration and prevent decomposition. Natron dries the body up faster than desert sand, preserving the body better. Often finger and toe protectors were placed over the mummy's fingers and toes to prevent breakage. They were wrapped with strips of white linen that protected the body from being damaged. After that, they were wrapped in a sheet of canvas to further protect them. Many sacred charms and amulets were placed in and around the mummy and the wrappings. This was meant to protect the mummy from harm and to give good luck to the Ka of the mummy. Once preserved, they were laid to rest in a sarcophagus inside a tomb, where it was believed that the mummy would rest eternally. The mummy's mouth would later be opened in a ritual designed to symbolize breathing, giving rise to legends about resurrected mummies. In some cases, a mummy has been discovered in an unmolested tomb, only to be found in a state of advanced decomposition due to the proximity of the water table. This was the case with the discovery in 1998 of the mummy of Iufaa, an Egyptian priest and administer who lived around 500 BC.