The earliest known use of a natural, soap-like material was the powder of nuts from the Reeta (Sapindus) tree, a powder used by Indians since antiquity. In accordance with Ayurvedicteachings, Hindus in India were obliged to bathe at least once a day, every morning.The Babylonians used clay cylinders containing a soap-like substance, dating from 2800 B.C.E. A formula for soap-consisting of water, alkali, and cassia oil-was written on a Babylonian clay...