Mummy Recipe Hard to Follow

Another gem from the Random Samples section of the Oct. 2 Science Magazine:

Frank Rühli wants to know just how the Egyptians did it. So he is trying to mummify human legs.

Rühli, a physician and head of the Swiss Mummy Project at the University of Zurich, and his collaborators severed the legs from a female donor body. One, the "control leg," was kept in an oven at 40°C and low humidity to replicate "natural mummification" in the Egyptian desert. The other leg, as described in ancient Egyptian records, was put on a pine board and covered with natron, a blend of four sodium compounds that pulls moisture out of the tissue. The researchers left it at 23°C to see what natron would do in the Swiss environment.

Other researchers have tried mummifying human remains. But the Swiss group is using advanced imaging technology, biopsies, and tests of DNA degradation for moment-by-moment analysis of the mummification process.

So far, the researchers have found that mummification in Zurich takes longer than expected: After 3 months, scans showed that the natron leg still had pockets of humidity, Rühli says. They have also discovered that storing an untreated leg in the heat doesn't work well. The control leg failed to dry out and started to decompose after a week. Rühli plans to repeat the experiment, this time encasing the control leg in hot sand.