Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/305

 either here or in any other instance which I have met with, to give a correct description of the dips of the schistose rocks which occur in the highland mountains, without running into endless details, since they are perpetually varying. It is perhaps fully as useless as it would be laborious to the observer and tiresome to the reader. These beds, at least for a short space, lie on the northern bank of the granite mass, and stretch away in a south-east line to Cairn na 'Chlavhan and Connalach more, which elevations consist entirely of quartz rock. The granite continues still visible to the eastward in the direction of the hills, but ceases to be red. It is now grey, and shews a slight tendency to a foliated structure.

This peculiarity of structure, imperfectly as it is marked, is an object of curiosity. I have already described a quartz rock as passing by a regular transition to granite, and here the granite in the vicinity of the quartz rock is found to have a foliated tendency, a tendency which not improbably unites it at some point with the quartz rock, although I did not discover that point of perfect transition. On the same summits I also picked up a specimen of genuine gneiss, but did not discover whence it had come.

The hill of Connalach beg shews a summit of granite, but it is a small space surrounded by quartz rock. The granite here passes into a variety which, with the same general aspect, contains crystals of hornblende. The two varieties are perfectly continuous, as continuous as the red and the grey, which I have just described.

Here then we have, as in numerous other instances, a confirmation of the geological identity of common granite, and of that which is considered as a separate substance by the name of Syenite. However distinct these two rocks may be considered as cabinet specimens, there is no distinction in their habits and connections, nor have we any reason to believe that the æras of their formation are