Meeting near Loch Eishort with the white compact quartz rock which was described in the original paper, I concluded that here, as elsewhere, it was a member of the primary rocks, and therefore without hesitation laid it down among the series which I considered to be micaceous schist, concluding also that I had in reaching it arrived at the bottom of that series which contained the blue quartz rock and schist. That white quartz is however a member of this very series, holding a parallel course with it, and being preceded as it is followed by red sandstone, blue quartz rock, and graywacké schist. This circumstance forms a material addition to the history of quartz rock, and an alteration no less material in that of the series to which the red sandstone belongs.
I must here remark that in calling so complicated a series of rocks by the title of only one of its members, the red sandstone, I have done so only on account of the necessity of using one term for the temporary purpose of a geological description, and that this one was chosen from the predominance of that substance. I can only add that this predominant member corresponds in mineral character with the other red sandstones which in Scotland occupy the intermediate place between the primary rocks and the secondary strata containing organic remains, and that it is connected by visible indications with many similar portions of the same rock to be found not only in Sky but in the neighbouring islands. As it is also followed in a conformable order by the limestone series formerly described, it possesses another common character with the usual red sandstone of other districts. If any person shall think that the whole of this series should be ranked under graywacké and called a transition series, I can have no objection, but am at the same time unable to see what advantage is gained by the substitution, or in what respect the science is aided by it; while at the same time the red sandstone will be as much transferred from its
