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of the Ural is now diminishing, but that of Siberia is increasing more rapidly; so that, in 1844, Sir R. Murchison stated the total produce annually of the empire at near three millions sterling. But all this is not clear gain; for Rose, in one case, estimates the cost of each zolotnik of gold at above eight rubles banco, whilst its value is above twelve, leaving thus only one third of the whole amount as profit, and it is only the very low rate of Russian wages that renders it possible to work the mines at all.
Leaving the gold deposits, we now turn to the extinct mammalia, whose remains are so constantly associated with them. The bones of the mammoth, the urus, the rhinoceros, and it is believed also of the mastodon, have all been discovered in these beds, where, indeed, from the superstitious feelings of the natives, it is almost alone possible to obtain them. The Baskirs, in former times, anticipating some recent theories, used to intreat the Russian miners, “ Take from us our gold, if you will; but for God's sake leave us the bones of our ancestors.' And the rude Samoides of the north still regard the mammoth as a subterranean monster, living in ice caverns, but destroyed when exposed to day, and then bringing misfortune on the family of the person who disinters it. To explain the occurrence of these bones in the Ural gravels, Sir R. Murchison supposes that in former times the mountains contained many lakes in their long winding valleys, on whose shores the animals lived, and into which their bodies were floated after death. It is these lake bottoms, laid dry and thrown into irregular forms by subsequent convulsions, that constitute the present gold alluvia of the Ural. But the chief abode of the mammoth has been the vast plains of Siberia, even then sloping down to the north, but bounded by a more southern Arctic sea, and thus, our authors argue, enjoying a somewhat milder climate and greater luxuriance of vegetation. Fortunately for science, not only the bones, but the flesh and skins of these extinct mammals have occasionally been preserved, embalmed in ice even for a longer period than Prince Menzikoff, who was discovered with skin, body, and mustachios
in perfect preservation, after lying in his grave for a century. These mammoths had their skin clothed by black hair twelve to eighteen inches long, below which was thick, reddish wool, showing that they were adapted, not, like their congeners of the present day, for a warm, but for a cold climate. This evident truth, first propounded many years ago by Dr. Fleming, and eloquently advocated by Mr. Lyell, has received new confirmation from the discovery of Professor Owen, the worthy follower of Cuvier, that its teeth essentially differ in structure from those of the present elephants of the
torrid zone, and were especially adapted to enable the mammoth to subsist on the coarse ligneous tissue of trees and shrubs, and thus, in complete harmony with its warm woolly covering, mark it out as a denizen of the north. Adapted in this manner for a cold climate, vast herds of these animals seem for many ages to have wandered over the Siberian plains, and to have had their bones, and sometimes their entire bodies, buried in estuary mud, or preserved in the frozen soil forming the substratum of the ground. So numerous are they, that in one place, Pallas says, the decomposing bones form a peculiar bed of what he names Osteocolle. Their teeth are a regular article of commerce, a ship freighted with them leaving Jeniseisk annually; and we have lately seen it stated, that some individual merchants will in a year export 16,000 lbs. weight of this antediluvian ivory; some single pieces weighing 200 lbs. each.* Their remains are, however, not confined to Siberia, but spread in less abundance over the whole north of Europe, and also in union with those of the urus, the rhinoceros (R. Tichorhinus) the elephant, and other peculiar species. All these gigantic powerful mammals are now extinct, except, perhaps, the Bos Urus, still represented by the Aurochs of the Lithuanian forests; whilst many species of mollusca, their contemporaries, survive in our seas and rivers. With the extinction of these races, probably during the final elevation of the chain, the ancient geological history of the Ural terminates.
But there still remain some singular chapters in that of the low lands of Russia and the surrounding parts of northern Europe, including even our own islands; chapters whose language geologists are not yet agreed in interpreting. From the south-western declivity of the Timan range, through all the northern provinces of Russia, Poland, Prussia, and the German states, to the eastern shores of Britain, the surface is covered by vast heaps of detritus and large fragments of rocks, of which no trace occurs in the immediate vicinity, nor for many --sometimes several hundred-miles distance. But when fol. lowed back to their native beds, all these erratic blocks, these wandering or travelled stones, are proved to have originated in the north—to be derived from the granitic and crystalline rocks of Finland and Scandinavia. Some points in regard to their distribution are very curious. They are not found in equal number in every part of the country, but accumulated, as it were, on particular points and localities. They are more common on the summits of the low hills, or undulations, than in the intermediate low grounds, and run out from these in long trainées, or heaps and ridges of rounded or subangular blocks. In general, they diminish in size and quantity to the south; the individual boulders seldom exceeding one or two feet in diameter near Moscow, whilst they are as many yards near St. Petersburg. But to this some remarkable exceptions occur, and enormous masses of angular forms have been drifted far beyond the former parallel. Their limit south has also in
* Augs. Allgem. Zeit. 1845, No. 69.
. some measure been determined by the nature of the country; few or none occurring on the high plateau of Orel, whilst they range far down the valleys of the Don and Desna, a tributary of the Dnieper, on its flanks. In its way south, this mass of detritus has drawn contributions from all the hard and stony masses over which it has passed, carrying portions of the Silurian rocks of Sweden, with their characteristic fossils, over the low plains of the north of Germany.
Such are a few of the more striking facts, to explain which many theories have been proposed. It was soon observed that the hard rocks of Scandinavia and Finland had been ground down, scratched, and polished, as if by the passage of some heavy and sharp body. Such striated surfaces are found in many other regions, and indeed were first noticed by Sir James Hall, in the vicinity of Edinburgh. It was natural to ascribe them to the same agent that had transported the debris and travelled rocks, and Hall considered that a violent debacle, rushing over the land from the west, and carrying with it heaps of mud, gravel, and stones, best explained both phenomena. More lately, Charpentier and Agassiz have revived a theory propounded originally by Playfair, though only to explain the local phenomena of the Alps, where glaciers even at the present day transport large masses of stone, and polish the rock surfaces over which they pass. These speculators suppose a former glacial period in the history of the globe, when ice and snow involved the whole north of the continent, and an immense glacier, creeping slowly down from the north by its own internal expansion, bore with it the great mass of drift and boulder clay, and those huge angular blocks of granite already mentioned. Though popular for a time, this theory has also been rejected, since it appears that glaciers move by their own gravity and only over sensible declivities of 2° or 3°. Then came the iceberg theory, in which vast rafts of ice, formed on the shores of northern islands, now the summit of the Scandinavian mountains, sailed away to the south, freighted with blocks of stone and heaps of mud and gravel. That icebergs both in the Arctic
and Antarctic oceans do actually possess this transporting power is beyond doubt, and they must ever keep their place as true causes in all speculations on the subject. It is also evident, that in passing over low rocks, such icebergs would rub and scratch their surfaces, and in this way many of the striæ might be produced. It appears a strong confirmation of this theory, that only the northern face of hills, or that turned to the point whence the drift has proceeded, is worn and striated, whilst the opposite side is rough and in its natural condition.
Admitting the agency of these icebergs to convey the larger angular blocks, Sir R. Murchison still thinks that another agent is needed to transport the great mass of smaller detritus and to striate the rocks. Referring to Mr. Russell's researches on the power and velocity of waves of translation, he supposes the Scandinavian mountains to have been suddenly elevated at many intervals, throwing off such waves, and also propelling forwards large bodies of drift in semi-solid masses.
He states, ' In its essential properties of weight, solidity, ductility, and materials for polishing and scoring at its base, a mass of moistened drift, one or two hundred feet in height, and a mile or two in length, must have embodied nearly all the properties
of a glacier, the nature of the movement and the actual state of such mass of detritus being properly understood. We must confess that this supposition is to us entirely inadmissible. We cannot imagine any method of forming such an isolated mass of debris and keeping it in the proper state of moisture and pliability. Nor supposing it once formed, can we conceive of any natural power by which masses of moist and pliant detritus' could be, in the author's own words, 'shouldered off • from the sides of mountains and hills or forced through gorges.' With all the difficulties attaching to the transportation of the detritus, and the striation of the subjacent rocks by ordinary sea currents and the ascertained agency of floating ice, this latter theory seems far preferable to that of Sir R. Murchison. But though differing from him in this one point of the theory, we cannot omit expressing our obligations to him for the large collection of accurate facts, by which the true theory can only be at length discovered.
Another singular deposit of the Russian plains is the Tchornozem, or Black Earth. It is only found in the southern provinces, being limited on the north by a waving line running from Kief by Tchernigof and along the bank of the Volga above Kazan, whence it passes into the valley of the Kama and the vicinity of Ufa. Traces of it are also seen in some parts of Siberia, on the east of the Ural. Even south of the above line it does not cover the
whole surface, but occurs in large though limited tracts, often fifteen to twenty feet deep, as far south as the granitic steppe, and on rocks of all ages.
• In travelling over these black tracts in a dry summer, we were often, during a whole day, more or less surrounded by a cloud of black dust, arising from the dried-up tchornozem, which is of so subtile a nature as to rise up through the sod, in rich grass countries, under the stamp of the horse's feet, and forms so dense a cloud, that the traveller is often begrimed like a working collier. The tchornozem is unquestionably the finest soil in Russia, whether for the production of wheat or grass. It is so fertile as arable land, that the farmers never apply manure ; and after taking many crops in succession, leave it fallow for a year or two, and then resume their scourging treatment.'
An analysis by Mr. R. Phillips showed that this earth consists of about eighty-three per cent. of silica and alumina, seven per cent. oxide of iron, nearly as much organic matter, with a small amount of lime and other substances. In the organic matter, M. Payen, a French agricultural chemist, finds nearly 2 per cent. of nitrogen, and thinks that this may be the principal cause of its fertility. Perhaps the fine levigation of the mass, and the due mixture of the whole forming a peculiar, loamy clay, permeable to air and moisture, may be a no less important element.
The popular belief asserts that this soil has originated from the decay of ancient forests. But there is no evidence that these ever existed in the tracts where it occurs, and, as Mr Strangways long ago observed, it contains no trace of trees, roots, or vegetable fibre. Sir R. Murchison believes it must be of marine, or at least subaqueous origin, and thinks it highly ' probable, that this fine silt may, to some extent, have been derived from the destruction of the black Jurassic shale, so uniform in its colour over all northern and central Russia. This opinion is confirmed by the black earth being only found to the south of the Jurassic rocks, and being invariably absent where the latter have not existed. Perhaps, however, we may regard it simply as the finer material of the drift borne farthest south in the gently flowing currents, and mingled with the dark organic mud derived from the destruction of some northern tundras. On this view the patches found in Siberia present no difficulty, for though the Jurassic beds do not occur in that region, there is no deficiency of mossy tundras.
In this rapid survey of the geology of Russia, we have at length reached the most recent period, or that in which we now live. It is usual to call this a period of repose, but the phenomena of the Russian rivers, especially those running to the north, show with