By J. Mac Culloch, M.D. F.L.S. Chemist to the Ordnance, and Lecturer on Chemistry at the Royal Military Academy at Woolwich.
V. Pr. Geol. Soc.
HAVING had an opportunity during the Society's late recess of collecting some specimens of the mineral productions and rocks of Scotland, I have transmitted them with a hope that other members who may have the means of so doing, will make still greater exertions in aid of this very necessary department of our museum. Such collections, however useless in an insulated state, acquire a real importance from their union, and form by their accumulation one of the leading objects of such an institution, a point of reference for authority whether geographical or mineralogical.
To these specimens I have been induced to add the miscellaneous remarks which form the present paper, with a view of attaching to them more interest than would accrue from the mere mention of a naked habitat, and for the further purpose of rendering the catalogue which must accompany them, more intelligible. These remarks include such geological observations on the nature and connections of the rocks from which the specimens were detached, as occurred to me at the time, or were the result of comparison with the observations of other writers who have treated the same subjects. Where the specimens themselves are deficient in the requisite purposes of