CLAY, Fireelay.
Chomar, . . . . Ilan. Sangi-klalam, . llixo. Gil ; Chikni mitt', firm Tannah, whiterlay,MALAv.
Clay is a compound, or perhaps only a mixture, of the two earths, alumina and silica, with water.
Pipc-clay, Nihnam, Kliarra, of a greyish-white colour, with an earthy fracture, and a smooth, greasy feel ; it adheres to the tongue, and is very plastic, tenacious, and Infusible. When burnt, it is of a cream colour, and is nsed for tobacco-pipes and white pottery. This is found in abundance in several parts of India ; and Hindus employ it for making the distinguishing nuirks on their foreheads, and (moistened with water) it is often applied round the eye in certain cases of ophthalmia, as well as to parts of the body that are bruised.
Potter's clay is of varions colours, chiefly reddish or grey, and becomes red when heated. Mixed with sand, it is formed into bricks and tiles. It is abundant in many parts of South-Eastern Asia.
Stourbridge clay resembles potter's clay to a certain extent, but is far more refractory in the fire. It is of a dark colour, owing probably to the presence of carbonaceous matter. It is exten sively used in making crucibles, glass pots, etc.
Brick-clay or lawn, abundant in S.E. Asia, varies greatly in appearance, texture, and com position ; its colour depending on the proportion of oxide of iron contained in it.
l'orcelain clay, the kaolin of China, is very abundant in S.E. India, produced by the decom. position of felspar, and of binary granite.
Fireclays are procumble at Streepermatoor, Tripasoor, Chingleput, liletapolliam, and Cudda pah ; indeed, are very common in many parts of India, and bricks can be made that resist the action of great heat. A clay found at Beypore, 20 to 30 feet below the surface. is used for fire bricks and for lining furnaces.
Unctuous clay is excavated from a pit near Kolat'h in large quantities, and exported as 811 article of commerce, giving a royalty of Rs. 1500 yearly. It is used chiefly to free the skin and hair from impurities ; and the Cutchi ladies are said to eat it to improve their complexions. The clay used for making pottery- in Sind is obtained from situations washed over by the Indus river, 10 feet under gnound. It is reduced to a fine powder, and soaked in water for 2.1 hours; after which it is kneaded with the hands and fret, and when it becomes dough-like, it is divided into lumps of the required shapc.—Tonnlinsmo; Drs. Moson awl Mohr: Tinrs Rajasthan, p. 203.