Lady Touti sure knew where to shop. The ancient Egyptian's 4,000-year-old tomb contained several cosmetic jars, one bearing the hieroglyphic label "high quality."
Scientists in France analyzing the jars' contents discovered that Egyptian chemists were surprisingly sophisticated. The ancient makeup bears evidence that manufacturers synthesized some of the compounds they needed using "wet chemistry."
"We expected to observe advanced processes in cosmetics preparation," says Philippe Walter, with the Laboratoire de Recherch des Muses de France in Paris. But, he adds, they didn't expect to find approaches this advanced.
In analyzing Lady Touti's toiletries and other cosmetic samples, the team discovered a relatively high abundance of laurionite and phosgenite - two lead-based minerals that can occur naturally, but not in quantities large enough to feed ancient Egypt's 800-year long appetite for cosmetics.
In an attempt to duplicate the process for synthesizing the two chemicals, the team turned to ancient texts that gave recipes. They mixed purified crushed lead oxide with carbonate-free water and rock salt. The solution was filtered daily for several weeks, yielding laurionite crystals with shapes similar to those isolated from the jars. When they added carbonates, the chemical reactions produced phosgenite.
The find, reported in the journal Nature, has prompted the researchers to search for comparable knowledge in other cultures of the same period (2500 to 2000 BC).