Our author next proceeds to Coll and Tirie. Of these, the former island chiefly consists of gneiss with veins of granite, and in one place with a vein of galena; and it is properly observed, that this appearance should be pursued, as some minerals of considerable value are occasionally found in gneiss. Occasional veins of basalt, which traversed the gneiss, led to a suspicion that the former is a primitive rock *. Considerable cliffs of quartz are observable in the interior parts of the island. Tirie resembles Coll in almost every respect. The sand-banks are however more destructive, which are usually connected by the roots of the arundo arenaria and galium verum. These, however, have been eradicated-the former to make ropes, the latter as a dying ingredient. The good effects of such plants are at present better known, and their destruction will be prevented. The account of the marble quarry, which has added to the flourishing state of this island, deserves notice.

The marble quarry is situated immediately upon the sea-shore, at a farm called Belephetrich: here the shore is low and rocky; but át a little distance there is an eminence, called the Hill of Belephetrich. The strata are nearly vertical; and are composed of hornblende rock, and a compound of deep-red coloured felspar and quartz, which has sometimes crystals of hornblende interspersed. The marble forms a stratum of very considerable extent; it appears also to be nearly vertical, and is bounded by the rocks we have just mentioned. It is crossed in some places by small veins of quartz and reddish-coloured hornstone; and I observed a vein of granite, composed of felspar and quartz, traversing it. This stratum of marble has been considered by several travelers as a vein; but I apprehend this is a mistake. In other countries we find marble in a similar situation: thus Voight informs us that it has been observed between hornblende slate and sienite, and even that it has been found between granite in Sweden.

Upon the opposite side of the hill of Belephetrich, there is a stratum of white marble, which is situated among the usual rocks which compose the island. This stratum seems also to have been quarried, but, like the other, is long since given up as unprofitable.' P. 29.

The author ought to have known that strata of marble are not very uncommon in many granitic countries. A stone from this island, called by Mr. Raspe a jade, in Mr. Greville's opinion greatly resembles, in almost every respect, the corundum or adamantine spar.

The mineralogy of Eigg, Rume, and Canna, follows. The former consists of strata of schistose clay, lime, and sandstone,

*If, as is contended by some able mineralogists, shells are found in some basalts, it will destroy this suspicion. We afterwards find at Eigg, basalt alter nating with sandstone.

alternating with basalt or whacken. In one part the basaltic rock is penetrated by veins of pitch- and horn-stone.

Although pitchstone has been discovered in various parts of Europe, it has not been before described as belonging to the rocks of trap formation. Haquet, indeed, mentions, that he observed basalt columns converted into glass, among the basalt of the Veronese. This is very probably pitchstone; yet we cannot say so with certainty, as the appearance is not described with sufficient exactness. Obsidian, however, which, as we have before observed, is nearly allied to pitchstone, has been lately observed by Humbold, stratified with basalt, at the top of the peak of Teneriff.'

P. 45.

Scure-Eigg is a vast and tremendous mountain, consisting of columns in various directions, and differing in the number of their angles. It is indeed formed in all the eccentric wildness of nature sporting without controul. The columns are of a species of porphyry, with a base of an intermediate nature between basalt and pitchstone.

Rume is nearly similar in its make, though it has no limestone strata; but our author found, in a ravine, pieces of limestone, with interspersed bituminous matter. The spot has been Isaid to have afforded coal.

Canna contains one of the best harbours in the Hebrides. It is formed by a little island adjoining, consisting of trap, and bounded by land cliffs of columnar basalt. The columns sometimes rest on tufa; but the latter occasionally occurs without the covering.

The pillars vary very much, not only in size, but also in the number of sides; and frequently they are to be seen bent, when their length and breadth is less than the upright ones. Immediately below the stratum of basalt, there is a stratum of wacken, which contains calcareous spar, elegant capillary zeolite, quartz crystals, blackish-coloured crystals, whose nature I am ignorant of, and, more rarely, crystals of leucit, or Vesuvian garnet. To this succeeds another stratum of basalt; and below it, a stratum of wacken; and so on, alternately, to the bottom of the cliffs.' P. 56.

On the other side of the island, coal, it is said, has been discovered, in a stratum six or eight inches thick, in a whinstone rock. In the tufa, bituminated wood is occasionally found, which leads the author to enumerate the different observations of mineralogists on this subject. It chiefly occurs in whacken or clay, occasionally in schistus, and is sometimes supposed to be flattened by the superincumbent weight.-Skye is described at some length. It is varied by mountains and lochs, and contains numerous caverns. The higher parts of the island consist of whacken and basalt; but the lower contain limestone, argillaceous, and other alluvial strata. In the whacken, coal is oc

casionally found. In some parts the rocks were porphyritic, and pitchstone seems to occur in the porphyry, either in strata or thin veins; but its particular state is left to future and more careful inquiry. The mountains from Sconser to Broadford are chiefly of porphyry verging to granitel. The mountain of Ben-na-callich is of marble mixed occasionally with hornblende and porphyry, sometimes, if we understand our author correctly, covered with a granitel. The description of the view from Ben-na-callich we shall transcribe.

We now hastened with eager step towards the summit, and soon reached the cairn, which is upon the most elevated part of the mountain. Here, our most sanguine expectations were more than realised, every faculty for a while seemed arrested, until we could burst into an exclamation on the vastness of the scene, and on the mighty and eternal power of Him who framed so great a work. Before us, were many great valleys bounded by lofty mountains, whose steep sides were red, owing to the powerful influence of the elements, and furrowed by the many torrents which collect during the dreadful storms that often reign in these wilds. At a greater distance, the dark, lurid and terrible summits of the Cullin mountains retiring in majesty among the clouds; thus dimly seen, adding much to the sublimity of the scene. To the north, we observed below us the low part of the island, with the isles of Rona, Rasay, Scalpa, and Pladda: towards the east and south, the rugged moun tains of the mainland appeared stretching in all the grandeur of Alpine wildness to the point of Ardnamurchan; and nearer, the isles of Eigg and Rume added to the variety of this interesting prospect. -We stood long enraptured with the wonderful scene; but the darkening of the sky admonished us to shorten our stay, and hasten again to the valley. The clouds were now seen driving through the glens, and covering the mountains with a dark veil; soon all was lost in grand confusion; what a few minutes before was clear and distinct, was now troubled scene of tremendous mountainous peaks, shooting above the dark clouds, and reddened valleys dimly seen through the driving mist and rain. We took the lea side of the mountain, and soon reached the house of Cory.' Vol. ii. P. 94.

Rasay consists of porphyry and sandstone; and the higher parts of gneiss and hornblende. Nearly opposite to Portree harbour, on the west, felspar porphyry appears, forming low cliffs on the shore. Above the porphyry is basalt.—The mineralogy of Rona resembles that of the north of Rasay; and Scalpa is a low island, chiefly alluvial; but the higher parts consist principally of granitel.

Having visited the islands adjoining the western coast of Scotland, our author sailed up the Sound to Elean-reach, situated on the main land, leaving the islands further west till another season. We trust he will not republish the present work with the future tour. We have already reprehended the disinCRIT. REV. Vol. 35. August, 1802.

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genuity of copying so much from his former publication, which deserves perhaps a harsher censure than it has drawn from us. Should he pursue this plan, we shall certainly give his conduct its true character. From Bernera, Mr. Jaméson proceeds to Fort-Augustus, passing Glen-Elg and Glen-Sheill. From the account of the latter, we shall transcribe the description of some wild and romantic scenery.

Immediately after leaving the inn, we entered, by a narrow, abrupt pass, into Glen-Sheill. Tremendous mountains rose on each side, but, farther distant, all was dark and indistinct: it was but twilight; the obscurity thus thrown over the scene was peculiarly impressive. Before us, towards the head of the glen, the clouds were cleared away as the day advanced, and the opening, the modest, mellow tints of the morning cheared us with the prospect of a charming day for a journey through a country so dreary and wild. We were soon grievously disappointed: the clouds were seen rapidly covering the mountains; the ravines, situated near the summits, ap peared white, from the water rushing over their rugged bottom; and soon the whole glen was obscured, and the rain poured down with great violence. We continued our disagreeable journey, which had but little diversity: only, now and then, a partial dispersion of the clouds allowed us to observe many grand, peaked mountains, rising to a tremendous height, far beyond the boundaries of the glen. At length, having reached far up the glen, we came to a narrow pass, where the waters were collected from the neighbouring mountains. They were precipitated over rude fragments of the rocks; and, swollen and pent up in a narrow channel, rushed impetuously forth until they gained the level bottom of the glen, where the river flowed "calm, sluggish, silent." Such scenes are the greatest ornament of the Scottish glens-where the stream, collected from the rude mountains, glides through the mossy wilds, and descends, by successive falls, through the rocks, shadowed by the overhanging woods, till gathering strength," it boils, and wheels, and foams, and thunders through." Indeed, in the course of this glen, we saw all the various beauties which a river displays in a wild and mountainous country. The tumultuous noise of the waters was reverberated from the neighbouring mountains, and continued to be heard long after we had lost sight of them. The road was now nearly impassable, torrents crossing it every few yards; which, in some places, were so rapid and deep, as to endanger our lives in crossing them: our guide having stumbled, with great difficulty saved himself. Having forded these torrents, we at length advanced into a more open part of the glen, where the road was better: here the storm began to abate; the clouds gradually rose; and in a few hours the sun again beamed upon us. When we looked back to the mountainous scene of Glen-Sheill, still obscured by dark clouds, it formed a striking contrast with the scene before us.' Vol. ii. P. 161.

The hills in this country consist of granite and micaceous schistus; but the mineralogy of the main land has been often

described, and our author's journey was too rapid to enable him to add much to the accounts of former travelers. He stops, indeed, to notice again Dr. Hutton's system, or has since interwoven his observations with his hasty tour. We can easily forgive him, however, when we reflect on the value and importance of the following geological remarks.

These objections bear much against Dr. Hutton's opinion, and may probably appear, in a considerable degree, to disprove it. I shall not stop here, however, but shall now mention a fact, which to me seems to remove, in a considerable degree, the doubts with respect to the connexion of the granite with the other strata. The observations of Werner, Charpentier, Saussure, Reuss, and other geologists of the highest character, have demonstrated that granite, when it is covered by strata of gneiss, gradually acquires a shistose fracture, and at length is not to be distinguished from it; the gneiss, when covered by micaceous shistus, gradually passes into it by the loss of its felspar; and lastly, when ardesia, or primitive argillaceous shistus covers the micaceous shistus, a distinct gradation is to be observed by the disappearance of the quartz, and the encrease of the argillaceous ingredient. Here then we have a demonstration that these different strata have been formed in the same manner, and nearly at the same time; therefore any speculations which refer to one of these kinds of strata are equally applicable to the others; consequently the hypothesis of Dr. Hutton is to be considered as unsatisfactory. The transition of these strata into each other is not an appearance confined to one country; it has attracted the notice of geologists in all parts of the globe, and has been universally considered as a proof of the identity of the formation of these different strata. The appearance of the veins of granite shooting from the strata of granite into the shistus, may be explained in the same manner as common veins. Granite strata are frequently traversed by veins of granite, and these veins, although in general of a different. grain from the rock through which they run, yet, in some instances, it is with great difficulty that we can distinguish them from the stratified rock. Now, as it is nearly demonstrated that granite, gneiss, micaceous shistus, and ardesia, are of the same formation, it is not at all improbable that rents would as readily extend through the gneiss and granite, as through the gneiss and micaceous shistus; and that these rents would be afterwards filled up with granite similar to that of the strata, and thus form the appearance of the granite invading the shistus.' Vol. ii. p. 167.

Mr. Jameson prefers the route by Garvimore to that by Fort-William, and proceeds by Dalwhynnie, Dalnacardoch, Blair in Athol, Dunkeld, and Perth, to the Frith of Forth. We find nothing added to what we already knew of the mineralogy of this district, if we except only the particular account of the mineralogy of the country between Fort-Augustus and Inverness. It consists of micaceous schistus and granite.

The mineralogy of the Orkneys is very imperfectly detailed,