Clay

a kind of earth originating chiefly from the decomposition of feldspar, and consisting largely of alumina, silica, soda, potash, and water. It is, practically, a batter or pudding of sand and alumina. Clay is traditionally yellow. The term "claybank" is applied to a horse of that color, but clays are often red from infusion of iron and, indeed, may be of almost any color. A pure clay is white. The war paints of the American Indian were merely clays of various colors. Fine clay, free from sand or grit, is the potter's material out of which crockery is made, and is the earth also from which tiles and brick are made. Pipe clay is a fine clay, free from iron and other impurities, suitable for fine pottery and tobacco pipes. The annual money value of clay products far exceeds the output of gold mines. Wheat and all members of the pea family, particularly the clovers, thrive in a clay soil. Some idea of the value of clay from an agricultural point of view may be had from the following statement. Estimating the yield of wheat at twenty bushels to the acre, the following table shows the number of crops of wheat for which the various elements entering into the composition of clay are sufficient:

See Brick; Pottery; Kaolin; Meerschaum; Adobe