424. CLAY FAMILY. Constituent Parts. Silica, Alumina, Lime, Oxide of Iron, Water, 100.00 Bucholz, in Gehlen’s Journal fur Chemie und Physique, b. ii. s. 31. Second Subspecies. Earthy Polier-Slate. Erdiger Polierschiefer, Karsten. External Characters. ' The colours are the same as in the preceding subsner- cies. It occurs massive. The principal fracture is thick and straight slaty; the cross fracture earthy. It is opaque. Rather brittle. It adheres strongly to the tongue; and absorbs water an aU no * se > ar| d the emission of numerous air- bubbles. It soils strongly. It is soft; and feels meagre. It is easily frangible; and Is so light as nearly to swim on the surface of water. 79.00 >1.00 1.00 4.00 14.00 Constituent
