57° CALC GENUS. near Newfol, where it occurs in reins of copper pyrites and fahl ore; the other at Tetfchen in Bo hemia, in a vein of lead glance. Geographic Situation. It is found in Thuringia, at Mont Martre near Paris; England, as in Oxfordlhire, Me of Sheppy, &c. Ufes. On account of its purity it is employed in taking the mod delicate impreffions ; alfo for crayons, and, when burnt and powdered, it is ufed for cleanfing filver. TWENTIETH
