CLAY GLNUS. Constituent Parts. Earth of Limoges. Silica 52 55 62 Alumina 47 27 Iron °>33 °>5 Water 14 Lime 2,0 Magnefia 12 Sulphat^of barytes 7.0 Rofe. Vauquelin. Ilajfenfrat Chemical Character. It is nearly infufible in the greateft heat of a p° r celain furnace. Geognostic Situation. Sometimes, as at Aue, near Schneeberg in ony, porcelain earth occurs in beds in gneifs, a is accompanied with quartz, and fometimes w» iron ftone. Sometimes it takes the place of feljp a ^ in forming one of the conftituent parts of we even find large cryftals of felfpar filled wit ^ At great depths in the mines of the Frey berg field, I have obferv?d beds of gneifs, c° m P et * . fheltero /
