The tourist who has visited any of our granitic districts, such as the south-western parts of Cornwall, the rugged scenery of Arran, or the hills of the Aberdeenshire Highlands, must be familiar with some of the forms of waste which the rocks of these regions display. Mouldering blocks, poised sometimes on but a slender base, and eaten away into the most fantastic shapes, abound in some localities, while in other parts, as for instance at the summit of Goatfell in Arran, the rock weathers into a sort of rude masonry, and stands out in its nakedness and ruin like some crumbling relic of Cyclopean art. In other districts, as in Skye and in the adjoining island of Raasay, the granitic hills are of a still more mouldering material. Their summits, white and bald, sometimes rise to a height of fully two thousand feet above the sea, while down their sides are spread long reddish-yellow tracks of debris intermingled with patches of stunted herbage. Every winter adds to the waste, and lengthens the lines of rubbish. Some of these hills form a good field wherein to study the disintegration of granitic rocks, such, for instance, as Beinn na Cailleaich, that rises from the shores of Broadford Bay. Around the eastern base of that mountain there stretches a flat moory district, with a few protruding blocks that have rolled down into the plain. The earlier part of the ascent lies over a region of metamorphic limestone, where the grey weathered masses of the calcareous rock, often like groups of mouldering tombstones, are seen protruding in considerable numbers through the rich soft grass and the scanty brushwood of hazel and fern. Leaving this more verdant zone, we enter a district of brown heath that slowly grows in desolation as we ascend. Huge blocks of syenite--a granitic rock of which the upper part of the mountain entirely consists--cumber the soil in every direction, and gradually increase in numbers till the furze can scarcely find a nestling-place, and is at last choked altogether. Then comes a scene of utter desolation. Grey masses of rock of every form and size are piled upon each other in endless confusion. Some of them lie buried in debris, others tower above each other in a rude sort of masonry, while not a few perched on the merest point seem but to await the storms of another winter to hurl them down into the plain. The ascent of such a region is no easy task, and must not unfrequently be performed on hands and knees. But once at the top, the view is enough to compensate a tenfold greater exertion. Far away to the west, half sunk in the ocean, lie the isles of Eigg, Coll, and Tiree, with the nearer mountains of Rum. North-west, are the black serrated peaks of the Coolins, that stand out by themselves in strange contrast with every other feature of the landscape. Northward, stretches the great range of syenitic hills, with the sea and the northern Hebrides beyond. Away to the east,