Talc. 437 Conftituent Parts; , Magnefia 38,54 Silica 3 8 . 12 Alumina 6,65 Lime °i4 I Iron I 5» 02 Wtegleb. Hrepfn. Helv. Magazin. iii. f. 166. Geognostic Situation. It occurs in primitive mountains, where it forms beds in clay flate, and ferpentine, and is accompanied **th chlorite and afbeft. Geographic Situation.. It is found in the Tyrol, Auftria, Stiria, Switzer- J a nd ; Scotland, in Breadalbane, and the Shetland dlands. Ohfer'iiations. It has a very ftrong refemblance to potftone, with *bich it has been often confounded. X, TENTH