"The eating of clay has been observed in [ native ] peoples and animals in all parts of the world since antiquity. Early writers described the widespread use of kanwa ( earth from a lick near Lake Chad ) for animals and humans in Nigeria. Long journeys were made to [ this ] lick to obtain a tribal supply of this earth, and it was then issued as rations to cattle and humans... " Eaton Earth PRIMITIVES USED CLAY - There is evidence that humans have been eating earth for at least forty thousand years. The use of volcanic ashes internally is almost older than civilization itself. Primitive tribes of various continents have used various types of clay for conditions of toxicity. Dr. Weston A. Price in his book, "Nutrition and Physical Degeneration:, pages 266-267, stated that in studying diets of certain tribes he examined their knapsacks. Among those examined in the high Andes, among those in Central Africa and among the Aborigines of Australia he reported that some contained balls of clay, a little of which was dissolved in water. Into the clay were dipped morsels of food. The explanation was that this was to prevent "sick stomach". These people were reported to use the clays for combating dysentery and food infections. In South America he found that the Quetchus Indians, believed to be descendants of the once powerful Incas, were largely vegetarians and he stated, "Immediately before eating, their potatoes are dipped into an aqueous suspension of clay, a procedure which is said to prevent 'souring in the stomach'. " Yet, only comparatively recently has the white man apparently begun to use kaolin, one of the clays.