We have a good example of this in the little mountain of Arthur's Seat, by this town of Edinburgh. This is a peaked hill of an irregular erupted mass; but on the south and north sides of this central mass, the basaltic matters had been forced also in those inclined beds among the regular strata. On the north side we find remarkable masses of whin-stone in that regular form among the strata, and lying parallel with them. The most conspicuous of these basaltic beds forms the summit of the hill which is called Salisbury Craig. Here the bed of whin-stone, more than 60 or 80 feet thick, rises to the west at an angle of about 40 degrees; it forms the precipicious summit which looks to the west; and this is an appearance which is distinguishable upon a hundred other occasions in the hills and mountains of this country. Rivers make sections of mountains through which they pass. Therefore, nothing is more interesting for bringing to our knowledge the former state of things upon the surface of this earth, than the examination of those valleys which the rivers have formed by wearing down the solid parts of alpine countries. We have already seen that the wide extensive valley of the Rhône, between Loiche and Kolebesche, as well as the whole extensive circus of the Rosa mountains, has on each side mountains of the same substances, the strata of which are horizontal; consequently, here the valley must have been hollowed out of the solid rock; for there is no natural operation by which those opposite mountains of horizontal strata could have been formed, except in the continuation of those beds. We are therefore to conclude, that the solid strata between those ridges of lofty mountains had been continuous. The most perfect confirmation which this theory could receive, would be to find that those ridges of mountains, which the Rhône divides in issuing from the Alps into the plain, had been also united, in forming one continued mass of solid rocks. But the observations of M. de Saussure, who has most carefully examined this subject, will leave no room to doubt of that fact. This view of the entry to the valley of the Rhône is too interesting not to give it here a place. It follows immediately after that which we have last transcribed. «Ces montagnes que j'allai sonder au haut des prairies qui les séparent de la grande route, sont composées d'un mélange très ressemblant au précédent, et ce sont-là, les derniers rochers primitifs que l'on rencontre en sortant des Alpes par cette vallée. Le village de Juviana, dont ils occupent les derrières, est encore à une lieue de St Maurice.