rising to such amazing heights, and braving the fury of the elements, after the more soft, and easily decomposed substances with which they had been clothed, have given way around them, we have so much rough and uneven, or rather viewed more tastefully, such variety of sublime and romantic scenery, in what are called the primitive districts in nature, that, in the words of the worthy Professor, whom I have already more than once quoted, we can even "observe a gradual change in the shape of mountains, also of their cliffs and valleys, from granite to clay slate; and these dif, ferences are so striking and characteristic, that a long experienced eye can, at a glance, from the summit of a mountain, point out with considerable certainty, the different formations of which a country is composed." In the northern part of our island, there is no want of opportunity for gratifying ourselves with sights of this kind: and Mr Brande particularly points out one district, which, for grandeur of scenery, and geological interest, he thinks, can scarcely be surpassed, viz. "the country between the eastern extremity of Loch Ness, and Fort George, and especially the rocks, over which the river Fyers pursues its turbulent and winding course. "I was so fortunate," says he, " as to arrive at this spot, when the falls were in full dignity and terror, owing to previous rain; and every gleam of sun, which penetrated the foliage of the surrounding firs and birch, trees, was refracted by the spray into rainbows, that seemed dancing in the chasm. The rugged irregularities of this district,-the fragments that lie thickly strewed upon the sides of its mountains,-the caverns that abound in its rocks, and the perpendicular pre cipice of the great cascade, considered conjointly with the peculiar texture and composition of the materials that form it, present many objects worthy the attention of the geologist, and may be regarded, as recording some great natural convulsion." Having been on the spot personally, and witnessed this grand and sublime exhibition of nature, under circumstances somewhat similar to those, in which this ac curate and masterly painter of creation saw it, I can the better vouch for the fidelity, and enter into the spirit of his description. I too, was so fortunate, as to witness it at a time when the falls were in full dignity, after previous rain,-but with this difference, that, in my case, the rain, still continued, and formed around, with the spray that arose from the fearful abyss below, a drizzling mist, which greatly obscured the surrounding scenery, and like the dim lustre, let in by the painted windows of some ancient cathedral, rendered more gloomy the overhanging foliage, which, on another occasion, when our English traveller visited the sequestered spot, was penetrated and enlivened by the golden beams of the great source of day! The conclusion at the end is very natural, and is rendered still more probable, as these awful solitudes have been proved, since the author visited them, to be at no great distance from the focus of a recent subterranean movement, which has left its effects visible, in the disjointed and distorted layers of stone, near the top of the spire, of the adjoining county town, of INVERNESS. 2 CHAPTER VII. ROCKS, TRANSITION AND SECONDARY. Grey-wacke, or Killas.-Transition, or Mountain Limestone.—Variegated Marbles.-Peculiarities of Transition Rocks.-Old Red Sandstone.-Distinguishing characteristics of Secondary Strata.Sea-coast in the neighbourhood of Dunbar described.-First Red Sandstone of the secondary series, and its associates Coal and Iron Stone. New Red, or variegated Sandstone, and its associate Gypsum, with its imbedded masses of Marl, Clay, Sulphur, and RockSalt.-Free, or White Sandstone.-Stratified Limestone.-Chalk. -Secondary Traps and Porphyries, so called.-Basaltic Specimens. -Uses of Transition and Secondary Rocks. { "Nor to the surface of enlivened earth, But to the bowel'd cavern, darting deep, "I see the leaning stratu, artful rang'd; The melting snows, and ever-dripping fogs.-IBID. We now come to a class of rocks, which rest upon, and are sometimes intermingled with the preceding, but which are, however, of a very different description; for although you do not discover any thing very dissimilar in the outward appearances of many of them, and from their resemblance to the class we have just been considering under the appellation of primary rocks, or that more properly and strictly denominated secondary, and the structure and properties which they have in common with them, may be viewed as a continuation of the former, or, some of them, as a commencement of the series of the latter, (in which light, they have been, and are still considered, by many celebrated modern geologists,) and, consequently, classed with either the one or the other; yet, it is the opinion of Professor Jameson, and others, that, "their imbedded fossil organic remains, less crystalline aspect, (than those of the primary class,) and particular rocks such as Greywacke, appear to characterize them, if not as a distinct class, yet as a separate group, in the grand series of rock formations." Of this Grey-wacke, or transition Clay Slate, as one of its varieties is called, it may be said, as of the other slaty formations, to which it is so nearly allied, that it abounds in metals.* Transition, or Mountain Limestone, also, often con❤ tains valuable repositories of metallic ores, but it may be accounted of itself a treasure, by reason of the enor- · mous masses of the most lasting and durable nature, which it has long furnished, and still continues to furnish, for our public works:+ and that almost infinite *. It is in rocks of this description, that the mines of Leadhills, and Wanlockhead, and the antimony mine in the neighbourhood of Langholm, are situated; as also the productive lead and silver mines of Hartz in Hanover, of Vorespotack in Transylvania,—of Brittany in France, and some of the rich mines in Mexico in South America. +Some of my readers were, perhaps, amused some time ago, with the sight of a drawing, in that useful publication, the Mechanics' Magazine, of the vessel that was constructed to carry these enormous variety of beautifully diversified marbles, which, geologically considered, come under this description of rocks.* blocks, which are used in the construction of that stupendous undertaking, the Break-water at Plymouth. But, they are, perhaps, yet to be told, that those blocks were masses of Mountain Limestone, a species of marble, which is quarried in such abundance at Oreston, in that neighbourhood, that 600,000 tons have already been taken up, and a good deal of it in masses of more than ten tons in weight. * Many of the varieties of this description of marble, have been found capable of receiving a very high polish, and to contain some curious imbedded substances in their composition, on which account, they may be said to be still better adapted, than the primary kinds, for various ornamental purposes,-among these we may enumerate the Derbyshire marbles, with their various intermixtures of fossil shells, and other marine remains, that at Wetton, near Ashbourne, which on account of the vast number of whitish and minute shells in its composition, is called the Bird's-eye Marble,—the beautiful variety near Monyash, which being full of marine figures in all directions, afford, when cut, a pleasing contrast, to the brown reddish colour in which they seem to float. Such also, are those beautiful slabs of Kendal marble, in which numerous corallines, and the remains of other marine animals, are found to vary their appearance in such a pleasing manner, as well as a number of those beautiful Scottish marbles, which, as I observed before, make it a matter of regret, that we should still persevere in sending for ornamental stones to foreign coun tries. There is a species of marble in the Duke of Gordon's lands, in the forest of Glenavon, composed of fine glittering broad grains like spangles, as large as the scales of fishes. In the farm of Blairmachyldach, about three miles south of Fort William, there is a very singular marble, consisting of a black ground, and flowered with white, in a light, elegant, and beautiful manner, like fine needle-work, or rather resembling the frosty fret-work upon glass windows in a winter morning ;§-and near the farm houses, upon the north side of the ferry of Ballachylish in Lochaber, there is a limestone, or marble rock, of a beautiful ashen-grey colour, and of a fine regular uniform grain, Williams' Min. Kingdom, vol. i. 407. $ Ibid, |