Mummies are one of the most characteristic aspects of ancient Egyptian culture. The preservation of the body was an essential part of the Egyptian funerary belief and practice. Mummification seems to have its origins in the late Predynastic period, when specific parts of the body were wrapped, such as the face and hands. It has been suggested that the process developed to reproduce the desiccating (drying) effects of the hot dry sand on a body buried within it.
The best literary account of the mummification process is given by Herodotus, who says that the entire process took seventy days. The internal organs, apart from the heart and kidneys, were removed via a cut in the left side. The organs were dried and wrapped, and placed in canopic jars, or later replaced inside the body. The brain was removed, often through the nose, and discarded. Bags of natron or salt were packed both inside and outside the body, and left for forty days until all the moisture had been removed. The body was then cleansed with aromatic oils and resins and wrapped with bandages, often household linen torn into strips.
Scientific analysis of mummies, by X-rays, CT scans, endoscopy and other processes has revealed a wealth of information about how individuals lived and died. It has been possible to identify conditions such as lung cancer, osteoarthritis and tuberculosis, as well as parasitic disorders such as schistosomiasis (bilharzia).