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time; and cannot, after what has been said in the former chapters, escape notice on a careful perusal. In Sweden, also, the granitic masses are said to bear the same relations to the primary slates as in Norway. Most German geologists consider that the granite of Saxony is also similarly circumstanced; and Bonnard and others, contrary to the published opinions of Haussmann, likewise regard the granite of the Hartz, not as the most ancient and fundamental rock of the district, but of a more modern origin, since it is, in many places, regularly interstratified with mica-slate and other crystalline schists, all of which are surrounded by grey- wacke, and appear to repose on the strata of this secondary rock. In Saxony, however, the appearances of this kind are of a more doubtful nature. As already observed in a preceding chapter, the granite of the Erzgebirge occurs in insulated masses surrounded by primary slates, as in Cornwall; and the latter rocks will be found, in the following details, to present other points of similarity. Gneiss and mica-slate are the prevailing crystalline schists in this mountainous chain; the former being the most abun dant at the eastern, the latter at the western extremity. The gneiss varies exceedingly in the proportion of its con stituent parts, and in the manner in which these are united. At Frey berg it is very micaceous anc. schistose, being well adapted for economical purposes ; whilst at Himmelsfiirst, on the contrary, it is of a more granular texture: so that Werner’s division of this rock into two kinds may be generally received. The granular variety is often coarsely crystalline, and exhi bits frequent passages into granite: and near the town of Schwarzenberg, it contains large pieces of whitish and reddish felspar, having a tendency to a prismatic form, which imparts to the gneiss a porphyritic aspect. In the schistose variety, the component minerals are arranged in regular alternating bands. 1 his rock contains several subordinate beds, differing from