Revealed: how to keep your mummy fresh
Researchers from Germany have revealed an ancient Egyptian secret for keeping mummies fresh, exposing a 70-year-old archaeological misconception at the same time.
Dr Johann Koller from the Doerner Institute in Munich and colleagues report in this week's issue of Nature that cedar oil, not juniper oil, was used to embalm ancient mummies.
The researchers used both laboratory techniques and also performed their own embalming in their efforts to discover the truth.
The researchers used a gas chromatography technique to analyse wood fragments taken from a 3500-year-old embalming jar dating from the 18th dynasty, which had been found near a mummy called 'Saankh-kare' at Deir el-Bahari in Egypt.
The test revealed that the embalming material originated from cedar trees imported in Old Kingdom times into Egypt from Lebanon.
Ancient texts by historians such as Herodotus and Pliny the Elder described the use of cedar oils in embalming. Pliny, for example, says: "The wood of the tree is chopped up and put into ovens ... the first liquid that exudes flows like water ... this is called cedar juice ... in Egypt it is used for embalming the bodies of the dead."
While ancient texts do say that cedar oil was used, scholars in the early 20th century came to believe juniper oil was used.
The confusion is understandable: for example, some juniper trees are commonly called cedars, such as the American red cedar Juniperus virginiana.
The researchers say that the confusion over the scientific names of cedars and junipers may have led to a misinterpretation of Pliny's ingredients by 20th century scholars.
As well as doing the chemical analysis, researchers also isolated the components of the embalming fluid and tested their effectiveness on pork bones coated with the compounds and left for 35 days. They then identified the most effective components in the embalming recipe.
Embalming fluids keep mummies extraordinarily well preserved, and the surfaces of mummies coated with such liquids are essentially free of contaminating micro-organisms, say the researchers.
Ancient Egyptian culture placed great importance on the afterlife. The exotic nature of cedar wood meant it was a luxury item for the Egyptians, and its use in embalming was an indication of the high social status of the user.
Dr Karin Sowada, Assistant Curator of Nicholson Museum says that cedar resin was a prestige item that would have made it preferable to other embalming agents.
"The oil of the cedar tree is one of the seven sacred oils that was used in the Old Kingdom for funerary rites."
"There was a luxury or prestige aspect to these coniferous resins as they were imported resins, and for high officials and kings to be embalmed by coniferous resin from Lebanon or the highlands was an added prestige that signalled one's status. If you could afford this kind of product you would."