M. Anatole Demidoff, may have told us that the whole of this district of Southern Russia does not more than rival that of one of our own smaller coal-fields, Sir R. Murchison makes a suggestion most important to Russia, viz., that the coal-seams which (along this line) skirt the Donetz on the south, and are so difficult to work from their dislocated condition, may hereafter be most advantageously pursued beneath the overlying chalk, which here occupies the northern bank of that river; in which case they may, he thinks, be found to extend in horizontal and unbroken masses.

In approaching the great north and south line of igneous eruption which constitutes the Ural chain, the Devonian and carboniferous rocks (which in Northern Russia are so little consolidated and so horizontal) are thrown up into hard and mural masses, through which the rivers escape from these mountains; and one of the striking lithographs which enliven the first volume represents a scene on the Tchussovaya, which might almost pass for a gorge of the Wye near Monmouth (p. 335).

In following these rocks into the dense forests of that chain, the geologist (laying before him the highly-finished and elaborate detailed map) will find in the text a full explanation of the manner in which these ancient strata have undergone dislocation, metamorphism, and mineralization, in proportion as they have been subjected to the invasion of eruptive matter; but, even amidst these sorely convulsed crystalline rocks he will be surprised to see how numerous little oases are laden with fossil shells, many of which are British species. Even at Cossatchi Datchi, on the Siberian flank of the chain, many fossils were discovered identical with well-known species of the British mountain-limestone. The recognition of these forms indeed conducted our authors through this Uralian labyrinth, and has enabled them to present to the public the first geological map of that highly diversified rocky region so famous for its masses of magnetic iron, its copper and malachite, and its gold and platinum.

Whilst, however, we pass thus rapidly over the great natural groups into which the subsoil of Russia has been divided, we must say a few words on the Permian system (the next group above the carboniferous), because its establishment seems to us to be of considerable importance in general classification.

The system named Permian is imperfectly and partially exhibited in the British Isles in the beds called lower red sandstone, magnesian limestone, and dolomitic conglomerate; but in Germany it is more copiously developed in the rocks which bear the hard names of Rothe-todte-liegende, Weissliegende, Kupfer-schiefer, and Zechstein. Finding that certain

marls,

marls, sands, and limestones, containing the fossil shells of this group, with the addition of many plants, occupied an enormous basin in the eastern portion of European Russia, extending from the Icy Sea to the steppes south of Orenburg, and from the Volga to the Ural Mountains (an area twice as large as the kingdom of France); and further noting that their imbedded forms connected them with the older rocks beneath, and distinctly separated them from those above-Sir Roderick applied to them the name of Permian, derived from the ancient kingdom around which these deposits had been accumulated. A general term was thus introduced to characterize a group hitherto without one, and which by the palæontological labours of his associates he was enabled to show constituted the true termination, in the history of the earth, of all those formations which could be included in the palæozoic series. Such is the result of the application of British and French science to an enormous region, the few parts of which before examined had been referred to the old red sandstone, to the carboniferous rocks, and to the new red sandstone, as well as to the zechstein and its associated strata. Not venturing now upon any attempt to describe the varied features of this widely-spread red deposit, we shall merely say that, for a distance of from five to six hundred miles from the edge of the Ural Mountains, it contains much copper, not in veins, as we are accustomed to find that mineral in our own country, but diffused in grains among the sandy and marly beds; the fossil plants which lie in the strata (strange to say) serving as the surest guides to the richest metalliferous spots!—a fact, however, which is satisfactorily explained in the work by the modern analogy of a solution from a vein which impregnated a peat-bog in Wales with copper ore. But besides copper, sulphur and gypsum, with rock-salt and salt-springs, abound; and one of the most interesting episodes of our authors is that wherein they relate their astonishment, when parching under a powerful sun in a treeless, saliferous steppe south of Orenburg, they came upon a fissure in a little mount of gypsum (adjacent to great masses of pure rock-salt), the interior of which, at less than ten paces from the burning sands, was filled with stalactites and stalagmites of solid ice. As the inhabitants one and all stoutly maintained that, during their long winter, when all the country was frozen up, this cavern was void of ice, and warm enough to sleep in, our geologists' stock of physical science could only enable them to venture on a rude surmise, which, after consulting Sir John Herschel, Dr. Robinson, and Professor Wheatstone, Sir R. Murchison reverts to, and which has been already clearly put forth (in reference, however, to ice-caverns in a very different country, the Jura) by

Professor

Professor Pictet-who argues that the air rushing into such caverns through vertical fissures will acquire their temperature, which must be generally at least as low as the mean temperature of the place, and must be still farther cooled by the effects of evaporation from the moistened materials it encounters, which, in the Orenburg case, must be increased by the excessive dryness of the external air of these southern steppes (p. 198).

Of the organic remains of the Permian system we can now say no more than that, through the labours of Verneuil and Keyserling, the numbers of the known fossil species of this age have been nearly doubled; and whilst these are distinctly connected with the older palæozoic strata-so M. Adolphe Brongniart, who has examined and described the plants, assures us that they can scarcely be distinguished from those of the carboniferous

era.

Quitting these lower deposits, we learn that Russia is poor in most of those mezozoic or secondary strata which abound in England and France. Of the new red sandstone, or trias, she offers, in all her immense area, but one small solitary patch (and that is even somewhat doubtful) in the insulated hill of Mount Bogdo, in the steppe of Astrakhan, visited and described by Count Keyserling, and which, being six hundred feet above the Caspian, has from remote times attracted the superstitious worship of the nomadic tribes around it.

The copious oolitic series, or terrain Jurassique of the French, instead of exhibiting at its base our lias and inferior oolite, or exposing the great or middle oolite, at once commences with what our friend the new Dean of Westminster will rejoice in hearing termed the Oxfordian group. The simplest explanation of this suppression of forms from the full geological series seems to be, as the authors give it, that the substratum, in this case the Permian mass, had been elevated above the ocean's level during the interval in which the wanting deposits were precipitated, and afterwards again submerged, so as to receive the sedimentary strata which next occur. Geological research makes us familiar with the evidences of many such oscillations of surface.

A reference to the general map is absolutely required to show over what vast tracts this Oxford clay, with associated sands and argillaceous limestone, have been spread from the country of the Samoyedes on the Icy Sea to Southern Russia; whilst our readers will doubtless be glad to find that in the several terms of the group are found the very fossils of our little Wiltshire Kelloway rock, and of the Oxford clay and calcareous grit, including the Gryphæa dilatata, so well known to Oxonian geologists, who have been led by Buckland (wony Axwv) from the meadows of Christ Church

Church to the platform in Shotover Hill. It is, in fact, this subgroup alone which represents the whole oolitic series from the plains of Prussia to the borders of Asia; and researches in the East have further taught us that it is abundantly developed in the Run of Cutch and in the Himalaya Mountains.

Of the Cretaceous system, so widely diffused in the south of European Russia, we may briefly say, that it does not vary more from our English types, even in mineral characters, than is seen when the same system is followed from this country to Eastern Germany, or from the south to the north of France; whilst the organic remains from Russia assure us that, however portions of the group may change their stony characters, they all belong to one natural system, in which pure white chalk appears at intervals from the British Isles to the Asiatic frontier.

In closing our rapid survey of the transition and secondary rocks of Russia in Europe we will merely add, that as all the organic remains of the former (palæozoic) are admirably described by Verneuil in the second or French volume, so are those of the latter (mezozoic) described by that excellent naturalist M. d'Orbigny; and these descriptions are accompanied by lithographic drawings which (we say it in fairness to the French collaborateurs in these splendid volumes) are unrivalled in artistical effect by any efforts yet made in England in this branch of illustration.

Oceanic tertiary Deposits. In the earlier stages of geology, writers were content with classing all the beds above the chalk under the loose and general name of tertiary. Here mammalia for the first time clearly displayed themselves; and the general character, proportion, and preservation of the fossil shells bore a decidedly recent aspect; but a more exact comparison of species led subsequent authors, especially Lyell, to adopt a fourfold division, distinguished by the proportion of species identical with those known, as still existing, which they contained-eocene, miocene, older and newer pliocene. We are ourselves persuaded that the fourth of these divisions is separated by so broad an interval from the former, that it requires to be considered as a totally independent order. The former class lead gradually less than half way in an approximation to the actual state of thingsthe latter establish a nearly perfect identity; and this not only in the species of organic beings inhabiting the surface of the earth, but in its general configuration. Thus we shall see that Murchison distinguishes these periods; the former as containing deposits formed beneath extended oceans-the latter as precipitated from partially-brackish inland seas, like the Aral or Caspian (from

which he denominates them), and containing the very same shells with those particular seas.

In the use of Lyell's terms, which depend on proportions not always easily ascertained, occasional confusion may occur ; thus the tertiary basin of Mayence, which Murchison (on the authority of the latest German writers) has referred to the lowest division, Lyell considers as belonging to the second; and the sub-Apennines generally are referred by Murchison to the second, by Lyell to the third period. We must premise these remarks to give clearness to the statements which we shall adopt in following the classification of the former authority. He considers the tertiary formations of a large portion of Northern Germany and Poland to be eocene, like those of Mayence, and with these therefore he classes all the northern portion of the tertiary district of his map. For we may observe a marked geographical demarcation thus limited——the northern line of tertiaries ascending the Vistula, and then descending the Dnieper till it cuts through the granitic steppe below Ekaterinoslaf, is marked as eocene; while everything south and west of that steppe is given as miocene: all the plains, in short, bounding the whole course of the Danube* and the Dniester.

The lower tertiary beds of Russia are usually characterized by the prevalence of argillaceous and siliceous deposits; they are traceable down the course of the Dnieper; and we cannot doubt of their true claim to the title bestowed on them in that district by Dubois de Montpereux and Von Buch; for at Butschak on that river, thirty-two species of fossil shells were obtained identical with those found in the London clay and calcaire grossier of Paris- the classical types of that formation. (p. 286). And the same character applies to those collected by our authors at Antipofka on the banks of the Volga.

The miocene system of Russia, like those of Styria, exhibits beds of limestone often of an oolitic structure, lithologically resembling our own Bath stone. The shells found in these strata in Russia and Poland generally correspond with those of Bordeaux and the sub-Apennines: a list of thirty-four Polish species is given (p. 294), and these demonstrate that the great salt-mines of Wielickza, which thirty years ago all geologists described as sure indications of our new red sandstone, really belong to the middle stage of tertiary.

* We may extend these remarks over the whole of Europe. All the southern tertiaries of Europe, e. g., those of southern France and the vale of Switzerland-of Italy, Greece-we may add of Asia Minor, too-appear to belong to the miocene class; while the eocene is confined to the basins of London, Paris, and Belgium.

Aralo-Caspian