The Egyptians cleansed body cavities in the mummification process with frankincense and natron. Myrrh was used by the ancient Egyptians, along with natron, for the embalming of mummies. In the 1960s, the Mining industry of Chad produced sodium carbonate, or natron. Salt was used in combination with natron in the desiccation process. These rivers feed Lake Victoria, Lake Nakuru and Lake Natron. The species also inhabits the Lake Natron area and West Kilimanjaro. In 1964 on his second Lake Natron expedition, Leakey met an archaeologist named Margaret Cropper. It crosses the border into Tanzania, where it empties into Lake Natron. This caldera is also known as Natron Hole or Trou au Natron. Herodotus insists that the body did not stay in the natron longer than seventy days. The volcano's crater, Trou au Natron, is in diameter and deep. Seventy-five percent of the world's lesser flamingoes are born on Lake Natron. After the body was washed with wine, it was stuffed with bags of natron. Natrona County was named for the deposits of natron found in the area. Lake Natron is where two-thirds of Lesser Flamingos reproduce.