Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/302

 which differs very essentially from those that I found in any other part of the range. It is composed of nearly an equal mixture of hornblende and epidote in small grains, with a few specks of mica. It is of a yellowish-green colour, of a close texture, with rather an uneven fracture, and is crossed in all directions by slender veins of compact epidote. In some instances, the surfaces of the irregular fragments into which it breaks, are covered with minute crystals of magnesia carbonate of lime, and with slightly magnetic oxide of iron: the rock itself does not act upon the magnet. It occurs in very large masses, but neither in the disposition of these, nor in the internal arrangement of its parts, does it exhibit any signs of stratification. Within a very limited space, it assumes different aspects; the difference seeming chiefly to depend on the greater or less abundance of the epidote, and also on different states of decomposition.

§ 19. The epidote is found on the End-hill, under various appearances; in some of these, the crystalline forms peculiar to this substance may be seen, but I did not meet with any complete well defined crystals: it is most commonly found in a compact and granular state, forming small veins of a yellowish-green colour, which sometimes pass through the granite, and sometimes through the sienitic rocks. It is not confined to the End-hill, but I found it in greater abundance there than in any other part of the range, particularly on the northern side of the valley, which separates that hill from the North-hill, and among the loose fragments that are scattered over that valley. It is very often found in veins mixed with quartz and with felspar, but the only place where I found it forming the constituent part of a rock was at the northern face of the End-hill. In some instances, the epidote would scarcely perhaps be recognized, especially where it is much mixed with felspar or quartz; but if a series of specimens be examined, from that in which it is very abundant,