POTTERS CLAY. 415 loam into brinks, to dry these in the shade, and after wards in the sun. The use of loam-brieks is of high an tiquity : for we are told that the ancient city of Damas cus, and the walls of Babylon, were built of bricks of this substance. 'Second Subspecies. Potters-Clay* Tiipferthon, Werner. Of this subspecies there are two kinds, viz. Earthy Potters-Clay, and Slaty l’otters-Clay. First Kindi Earthy Potters-Clay. . . ' ' Erdiger Tbpferthon, Werner. fcrdigcr TopftTthmi, Steffens, b. i- s. IPS. Id. Lenz, b, it. s. 550. External Characters. ■Its colours are greyish and yellowish white; also light" R moke, greenish, and bluish grey. It occurs massive; and is friable, approaching to solid. Internally it is generally feebly glimmering. The fracture in the large is filte-grained uneven; «* the small fine earthy. It is more or less shining in the streak. It is very soft, passing into friable. It adheres strongly to the tongue; more strongly than I°am. It