before he obtains a view of the chain. Those persons, indeed, who have only passed over it by the route to Ekaterinburg, at the rapid rate of Russian travelling, might almost doubt the existence of a chain, for the road is there carried over the watershed at the point of its greatest depression, and where the outline is round-backed and featureless. The same may be said of the central crest between Blagodat and Serebriansk, and also of the pass near Katchkanar in the parallel of Verkhoturie, by both of which we travelled, except that upon these lines the divortia aquarum' is enlivened at intervals by bold and serrated crags. From certain points, however, on the Siberian side, the traveller can form a more adequate conception of these mountains. In travelling by the ordinary route from Europe, he gradually approaches them from undulations, amid which the central ridge is often nearly lost, whilst to many parts of the lower plateau of Siberia they present themselves as a serrated, mural, and naked ridge, which, peering through the forests, has the aspect of a mountain escarpment.'--pp. 342, 343.

Such is the external aspect of this mountain barrier, dividing the continents of Europe and Asia, and on which some of the old geographers bestowed the proud name of“ Cingulus terræ,” the girdle of the earth.* The general features of their geological structure have been very ably investigated by several distinguished geologists, though Sir R. Murchison is the first who has ventured to record the details in a general map. Referring the geologist to his work for these, we shall only remark that the Ural seems to be formed over a long rent or fissure in the earth's crust, or rather over a series of such rents, generally parallel and running in the same direction, though not always in one straight line. Through these, various igneous rocks, at different geological epochs, have found their way to the surface, at the same time, however, forcing up, fracturing, and metamorphosing the stratified formations on the sides. Among the more important igneous rocks is granite, greatly developed from the southern extremity as far north as Miask, and in less extent even in higher latitudes, particularly on the Asiatic declivity. Nearer the centre of the chain, and prolonged through its whole extent, are numerous porphyries, syenites, greenstones, and augitic rocks, exhibiting many varieties of mineral composition. More rarely, masses of serpentine also occur. Next follow long, irregular, yet generally parallel bands of altered or metamorphic rocks, among which chloritic and micaceous slate are most abundant, with beds of quartz rock, crystalline limestone, or marble and jasper, the last with some of the porphyries

6

and other igneous masses cut into beautiful ornamental objects. To these beds, further from the ridge, succeed bands of the older Palæozoic rocks, folding over in numerous undulations, till they sink below the Permian formations in the plain. Sir R. Murchison regards the central crystalline beds as truly portions of Silurian or Devonian rocks, changed by contact with the igneous masses that have burst up from below. By comparing,' he remarks, different portions of this chain, and by following its masses upon their strike, we are assured that the same zone ' which in one tract has a mechanical aspect, and is fossiliferous, ' graduates in another parallel of latitude into a metamorphosed 'crystalline condition, whereby not only the organic remains, but even the original impress of sedimentary origin, are to a great degree obliterated.' Of the great truth of the metamorphic change of rocks, of the occurrence of fossils in one part of a stratum which in another part becomes wholly crystalline, full and satisfactory proof is found in the volumes before us, to which we must refer such of our readers as, like the authors, feel high respect for a true characteristic fossil.' The mineralogical details of the rocks will be found in the highly valuable work of Gustaf Rose, describing his visit to these mountains in company with Humboldt.*

enormous masses in various parts of the chain, and at Nijny Tagilsk, where it is wrought as an open quarry, a face of it is exposed nearly a hundred feet high, and several hundred feet long, rudely bedded, and traversed by numerous joints. In Mount Blagodat, on whose summit the wild Voguls sacrificed, by fire, their chief Tchumpin, for discovering the subterranean wealth of their land to the Russian intruders, large stores of it also exist. Of the igneous origin of this ore there seems to be little doubt, as it is a common constituent of trap rocks in most countries, and in the Ural forms part of a rock of felspar and hornblende, those portions where the iron is most abundant being wrought as an ore.

Next in age our authors would place the cupriferous deposits formed before or during the deposition of the Permian rocks on the west, and previous to the upheaval of the main ridge, or central water-shed of the Ural. The proof of this lies in the fact, that whilst the largest original veins and masses of copper ore are on the eastern side of the chief ridge, all the detritus of these ores, all the water impregnated with cupriferous matter, seems to have flowed to the west, where, with the other debris of the ancient Ural rocks, and the vegetation that grew upon them, it has formed the Permian beds. Hence, Sir R. Murchison concludes that this dividing wall did not then exist, but has been elevated at a more recent period; and on the same ground, with the absence of the Permian formation he argues that Siberia, at that time, formed part of a continent, though in the tertiary epoch again submerged below the sea. cimen of these copper deposits, we may mention the mining ground at Nijny Tagilsk, within a mile of the iron ore lately mentioned. Here, between ridges of eruptive igneous rocks, strings and veins of copper ore occur; and in one place, below 280 feet of a cupriferous deposit, resembling a slightly consolidated heap of detritus, but probably the higher part of a broad vein, an enormous, irregularly boytroidal mass of solid malachite was exposed at the time of Sir R. Murchison's visit. The surface only was then laid bare, measuring eighteen feet long, by nine broad, and was estimated to contain 15,000 poods, or half-a-million pounds of solid malachite-of immense value eren as an ore of copper, still more as an ornamental stone.*

The next period in the history of the chain was that of the

As a spe

Malachite consists of about 72 per cent oxide of copper, 20 carbonic acid, and & water, and, when pure, contains 57 per cent. of copper. The finest ornamental specimens bave been procured from the Russian mines, and remain in the palaces and museums of that empire. Some very splendid vases, and other oroamental articles, may, however, be seen in the museum at Berlin, NO. XII.

X

deposition of the precious metals. From the total absence of all auriferous matter in the ancient conglomerates on the west, and in the tertiary grits upon the east, it is concluded that the chain became auriferous during the most recent disturbances by which it was affected, and that this took place when its • highest peaks were thrown up, when the present water-shed was established, and when the syenitic granites, and other comparatively recent igneous rocks, were erupted along its eastern slopes.' Grains of gold and platinum have, in truth, only been found in that detritus in which bones of mammoths and rhinoceroses have also been detected ; and the very nature and form of the ground where these occur show that this took place when the present configuration had been, to a great extent, brought about, and when valleys existed in which dwelt animals closely allied to those that now live among us. At that time, the Ural mountains were probably a low ridge along the western shore of the Siberian continent.

It is from these alluvial deposits, generally occurring in the river valleys, that most of the Ural and Siberian gold has been procured. It is found, in portions' so minute as to be rarely perceptible to the eye, among gravel or shingle, seldom less coarse than that around London and in the east of England, and . com

posed chiefly of moderately-sized and small subangular frag'ments of the subjacent rocks'-a detritus altogether of a local character, with no intermixture of far-transported materials. This is well seen at the mines of Berezovsk, near Ekaterinburg, which, from 1745 to 1841, had furnished fifty-two million poods (each 36lbs. 2oz. avoirdupois) of ore, from which 679 poods of gold had been extracted. In these mines the gold alluvium, covered by clay and soil, rests in the inequalities of talc, chlorite, and clay slates, traversed by a vein of that variety of granite which Rose names beresite. In this vein are many smaller veins of quartz, with which the gold is mixed, and shafts have been driven into it in various directions in pursuit of the precious metal. In the gold detritus, eighteen to twenty feet below the surface, and two hundred yards from the tiny stream that now flows through the valley, tusks and other bones of the mammoth were discovered. We cannot even allude to all the places, scattered for seven degrees of latitude along the chain, where gold alluvia has been ascertained to exist. It is enough to observe, that they are all in the immediate vicinity of eruptive igneous rocks, and on the eastern flank of the ridge. Chrestovodsvisgensk is the only mine of any magnitude which fairly lies at the western foot of the Ural, and is also remarkable as the place where diamonds have been discovered. The peculiar circumstances under which these gems were first found, for a time threw doubts on the reality of their Russian origin, but both Humboldt and Murchison express their belief in the fact, which is on other grounds not improbable. Above forty specimens have been discovered, but we believe none of them large or of much value.

Wherever the auriferous zone appears, Sir R. Murchison observes, 'the phenomena are essentially the same. The alluvium is everywhere a coarse local detritus, varying in thickness from two to ten and twelve feet, and usually covered by much stiff clay. The component stony fragments in each work necessarily vary, according to the nature of the adjacent rocks; but in almost every case quartz is abundant, generally accompanied by pieces of highly crystalline chlorite schist, talc schist, or clayslate. In one quarry or set of works, fragments of beresite or decomposed granite prevail; in another, greenstone porphyry; in a third, serpentine; in a fourth, augite porphyry. Iron pyrites appear in one, and not in another, but garnets, zircons, magnetic iron ore, chromate of iron, specular iron, and other iron ores, are, with rare exceptions, common to all these accumulations.' The ores of platinum occur in similar, but in most cases distinct, deposits. Only it is rarely accompanied by the veinstones of quartz, like gold, and the detritus consists chiefly of serpentine and greenstone, whilst chromate of iron is its most usual associate. It is much rarer than gold, and, in consequence of the cost of production, most of its mines have been abandoned, except those belonging to the Demidoff family.

Both the gold and platinum are usually found in very minute grains. Pieces of the latter from a zolotnick (66 grains) to near a pound are not uncommon, and others of three to eight pounds weight have occurred. At Zarevo-Alexandrofsk, from 1824 to 1826, ten pieces or 'pepites' of gold were found, weighing together 2 pood 343 zol., or above 93 pounds English avoirdupois. Another piece, of 22 pounds avoirdupois, had also been discovered at the time when the Emperor Alexander visited the mine, and was the largest known, till in 1843 another enormous gold boulder was turned up, weighing about seventy-eight pounds English.* These large masses are, however, no proof of the general richness of the mine, but rather the reverse. In general, the alluvia yields only from 1 to 1 zolotnik of gold in 100 poods of gravel, or from one part in 400,000 to one in 1,600,000; some of the richest have for a time produced five or eight zolotniks in 100 poods, and one even half a pound from this amount of ore. The gold produce

See Rose, Reise, vol. ii. p. 36–39; and Murchison, vol. i. pp. 489, 90.