The Memoir which I am about to submit to the consideration of the Royal Society, relates to the melancholy history of a boy who was born blind and deaf; and who, of consequence, has derived all his knowledge of things external from the senses of Touch, of Taste, and of Smell.

The tract of country extending across this island, from the sea-coast of Galloway to that of Berwickshire, consists, with little interruption, of that species of rock, which has of late been most generally known by the German name of Grauwacke. But as this rock does not differ essentially from what in Cornwall is called Killas, I am disposed, in concurrence with several members of this Society, in particular with Mr Allan, who has of late been in Cornwall, and has paid particular attention to that subject, to reject the uncouth term Grauwacke, and adopt that of Killas, as being more congenial to our language.

Although we have many writers on geological subjects, whose works are distinguished by ingenuity of doctrine, and novelty of opinion, and, among them, some who have made advances towards arrangement; it was reserved to the celebrated Werner, to introduce means, by which rocks might be described with some degree of precision. Many ingenious theories were invented, to account for their formation; but little or no attention was paid, to the acquirement of an accurate knowledge, either of their composition, or their relative position in nature; although these certainly appear to be the bases, on which such speculative opinions ought to be founded.

We are never more disposed to give credit to a philosophical system, than when we meet with a case of its successful application, unknown to the author, or containing circumstances which he had not taken into account when he formed that system.

The facts brought forward in the following paper, which, according to my view of the subject, clearly indicate the operation of immense torrents, can be accounted for, I think, in a very satisfactory manner, by the Huttonian Theory, and consequently afford some very powerful arguments in support of it.

If such tremendous agents did in reality exert their influence in the Alps, it is not conceivable that other countries, situated lower, and composed of materials much more frail, could have been spared. We hear in fact of similar traces, more or less distinct, in all quarters of the globe. From the bones of animals, natives of the hottest climates, which are found over a frozen region of vast extent in the Russian empire, Pallas concludes, that an enormous torrent had transported their carcases across the ridge of Tartary.

The singular appearances which were presented to my view by the Trap Rocks of Iceland, and the interest which they excited, made me resolve, as soon as I had given an account of that country to the public, to visit the Islands of Faroe. This expedition was undertaken, for the purpose of ascertaining, whether, in a Trap Country, where no traces of external volcanoes existed, any thing similar to the peculiar features of the rocks of Iceland was to be found. In the latter country were discovered a series of rocks, lying above the beds of Trap, which bore the most striking marks of igneous origin; in some instances having a perfect resemblance to ordinary Trap, and in others to the common Lavas of the country. The beds of Trap, and those above them, being separated by mechanical depositions of Tuffa (Trap-Tuff), led me to the conclusion, that the whole of the beds had been formed at the bottom of the sea, by successive eruptions of a submarine volcano.

Sir George Mackenzie having already given a paper, entitled, “An Account of some Geological Facts observed “in the Faroe Islands,” it may be necessary to explain why our communications were not combined in one. This was simply owing to our objects being in some measure dissimilar. He was anxious to compare the facts presented in a country decidedly volcanic, with those in a trap district, where no traces of a volcano were to be discovered; consequently, his observations were confined to particular facts: whereas my object is to describe, without relation to theory, whatever appeared to me interesting in a geological point of view.